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Author: 


Ure,  Andrew 


Title: 


A  dictionary  of  arts, 
manufactures,  and...2V 

Place: 

New  York 

Date: 

1854 


qs-si3g,i-i 


MASTER    NEGATIVE   # 


COLUMBIA  UNIVERSITY  LIBRARIES 
PRESERVATION   DIVISION 

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140 
Ur2 


Ure,  Andrew,  1778-1867. 

A  dictionary  of  arts,  manufactures,  and  mines; 
containing  a  clear  exposition  of  their  principles 
and  practice,  by  Andrew  Ure  •••  Reprinted  entire 
from  the  last  corrected  and  greatly  enlarged  Eng- 
lish edition  •••   New  York,  Appletoii,  ld54. 

2  V.   illus.,  diagrs.   24P". 


L 


(Continued  on  next  card) 


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140 
Ur2 


Ure,  Andrew,  1778-1857.  A  dictionary  of  arts, 
manufactures,  and  mines.  1854.   (  Card  2  ) 

vc^---  A  supplement  to  Ure's  DictionarvoP^"^ 
arts,  malltrf^tures  and  mines,  containi«^"'a  clear 
exposition  of  tlteix.m'iAciple^..€tnd^ practice. 
From  the  last  e diti on, ^jjjd^^y  Robert  Hunt  ... 
assisted  by  numep>«s  contribu^ra...^. .  New  York, 

Appleton, 

illus.,   diagrs.     26^. 


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LIBRARY 


School  of  Business 


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DICTIONARY 


OF 


ARTS,    MANUFACTURES, 


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MINES; 


CONTAINING 


A  CLEAR  EXPOSITION  OF  THEIR  PRINCIPLES  AND  PRACTICE. 


BY 


ANDREW   UEE,   M.  D., 

F.K.8.  M.G.S.  M.A.8.  LOND.  ;    M.  ACAD.  N.8.  PHILAD.  ;    8.  PH.  800.  N.  OERM. 

HANOV. ;    MULII.  ETC.  ETC. 


.  > 


»       >       »    r  ♦ 


ILLUSTRATED  WITfr  NEARLY-  SIXTEEN  EIXDRED  ENGRAVINGS  ON  WOOD 


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•    EEPlUNVi,*p    BNllRE    FXOM'    IHE    ;..\ST 


1  •  t       •      «  » •       * 


CORRECTED  AND  GREATLY  ENLARGED  ENGLISH  EDITION. 


IN  TWO  VOLUMES -VOL.  L 


D. 


NEW-YORK : 
A  P  P  L  E  T  O  N    &    COMPANY 


3  46    <fe    3  48    BROAD  WAV, 
M.DCCC.LIV. 


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PREFACE. 


It  is  the  business  of  operative  industry  to  produce,  transfonn,  and  dis- 
tribute all  such  material  objects  as  are  suited  to  satisfy  the  wants  of  man- 
kind. The  primary  production  of  these  olijects  is  assigned  to  the  husband- 
man, the  fisherman,  and  the  miner  ;  their  transformation  to  the  manufaciu/ei 
and  artisan;  and  their  distribution  to  the  engineer,  shipwright,  and  sailor.* 
The  unworked  or  raw  materials  are  derived, — 1  from  the  organic  processes 
of  vegetables  and  animals,  conducted  cither  witliout  or  with  the  fostering 
care  of  man  ;  2.  from  the  boundless  stores  of  mineral  and  metallic  wealth, 
arranged  upon  or  within  the  surface;  ol'  the  earth  by  the  benignant  Parent 
of  our  being,  in  the  fittest  condition  to  exercise  our  physical  and  intellectual 
powers  in  turning  thorn  to  iho  uses  of  life. 

The  task  which  1  havo  undertaken  in  the  present  work,  is  to  describe 
and  explain  the  transforiurttions  of  these  primary  materials,  by  mechanical 
and  chemical  agencies,  into  general  objects  of  exchangeable  value,  leav- 
ing, on  the  one  hand,  to  the  mechanical  engineer,  that  of  investigating  the 
motive  powers  of  transformation  and  transport ;  and,  on  the  other  hand,  to 
the  handicraftsman,  that  of  tracing  their  modifications  into  objects  of  special 
or  local  demand.  Contemplated  in  this  view,  an  art  or  manufacture  may 
be  defined  to  be  that  species  of  industry  which  efl'ects  a  certain  change  in 
a  substance,  to  suit  it  for  the  general  market,  by  combining  its  parts  in  a 
new  order  and  form,  through  mechanical  or  chemical  means.  Iron  will 
serve  tlie  purpose  of  illustrating  the  nature  of  the  distinctions  here  laid 
down,  between  mechanical  engineering  ;  arts  and  manufactures  ;  and  handi- 
craft trades.  The  engineer  perforates  the  ground  with  a  shaft,  or  a  drift, 
to  the  level  of  the  ore,  erects  the  pumps  for  drainage,  the  ventilating,  and 
hoisting  apparatus,  along  with  the  requisite  steam  or  water  power  ;  he  con- 
structs the  roads,  the  bridges,  canals,  railways,  harbors,  docks,  cranes,  &c., 
subservient  to  the  transport  of  the  ore  and  metal ;  he  mounts  the  steam  or 
water-power,  and  bellows  for  working  the  blast-farnaces,  the  forges,  and 
the  cupolas  ;  his  principal  end  and  aim  on  all  occasions  being  to  overcome 
the  forces  of  inertia,  gravity,  and  cohesion.     The  ores  extracted  and  sorted 

•For  correct  and  copious  information  upon  agricultural  production,  I  nave  great 
pleasure  in  referring  my  readers  to  Mr.  Loudon's  elaborate  Encyclopedias  of  ^igriculiuref 
Gardening,  and  Plants  ;  and  for  mercantile  production  and  distribution,  to  Mr.  M'CuJ- 
loch'e  excellent  Dictionary  of  Commerce  and  Commercial  Navigation, 


j^  PREFACE.      , 

by  the  n,iner,  and  transported  by  ^^^  ^^^f^^:^^!^'^!  t^'et^"™ 

there  skilfuUy  blended  by  the  "°"-™f '«' ("'^"X S  Sue  proporUons  ol 
in  a  furnace  appropriately  constructed  along  with  theudu^^  P^.^ 

flux  and  fuel,  whereby  he  ^reduces  them  ^  cast  Kon  ^^^^^^^ 

which  he  runs  off  at  the  right  periods  '««  ™"?"  S  "hemical  agencies, 
he  then  transforms  this  crude  "^^Wj^^^^J,^;^^  for  the  general  market ; 
into  bar  and  plate  iron  «fj''n«"/f'f  ^h^^"'' -^^^^^^^  Z  the  Cementation  fur- 
he  finally  .-""^erts  the  best  oMheba^  hTb;st  of  1  plates  into  tin-plate, 
nace,  the  forge,  and  the  'J'-h^"™^' '  «^    ,        j^.^  processes .  into  objects 

tag  or  E  taJicB. » lb.  loek.nua.  g«i..m,th,  .».h.n...h,  eu«.m,«, 

•■■Si  S-  *.  p™,p...  -b»  h._j=  ..™i  .<•  j;--  -  ■;  3»K 

^fZ.  ^nWt  would  hive  presented  a  misceUaneous  farrago  of  mcon- 
'^ou'sVr:id"%rn:m'ero:s  to^allow  of  *!>-  being  expounded  m^^^^^^ 

E:rar3:trs:titvTrbr^^^^ 

I  readily  '^'^^n^w'^ee  /  j^     ^     ^■^^  ^f  selection ;  havmg 

^eTcr^^ai^ed  IT  nteul  eTa^^^  influential  friends.to  introduce  a  few 
alleles  which  I  would  gladly  have  left  to  the  mechanical  cnnneer  Of 
these  Prin  tVis  one, Ihich,  having  had  no  provision  made  for."  «  my 
ordinal  plafwas  too'  hastily  compiled  to  ''dmit  of  my  descnbing^^^^^ 

suitable  figures,  the  flat-printing  ='"'«™^"<=  ™f  H  "ff  a  mecSrwhich 
wherewith  the  pages  of  this  volume  were  worked  ofi^;  a  mechanism  wmcn 
Tregard  as  the^m^st  elegant,  precise,  and  productive,  hitherto  employed  to 
PYPpiite  the  best  Style  of  letter  press.  •  „„  « 

I  have  imbodied  in  this  work  the  results  of  my  long  experience  as  a 
Professor  of  Practical  Science.  Since  the  year  1805  when  I  entered  aj 
an  early  age  umm  the  arduous  task  of  conducting  the  schools  of  chemistty 
and  manufacmres  in  the  Andersonian  Institution,  up  to  the  present  daj 

Tharbeen  Suously  engaged  in  the  ^'J'-iy --^  ^PXTn^f  sdonaSy 
the  chemical  and  many  of  the  mechamcal  arts.  Consulted  professionally 
by  pro^^eto  s  of  facto'^ies,  workshops,  and  mines  of  -"»"«  "^ff^^P*^^: 
^th  in  this  country  and  abroad,  concerning  derangements  m  their  opera 
^ns  or  defect"  nTheir  products  I  have  enjoyed  peculiar  opportunities  of 
bccomk^e  famtliar  with  their  minutest  details,  and  have  frequently  had  the 
toTforfune  to  rectify  what  was  amiss,  or  to  supply  what  was  wanting. 
§rfhes"ores  of  information  thus  acquired,  I  have  availed  "-y^^lf  "J^  J^„: 
present  occasion;  careful,  meanwhile,  to  neglect  no  means  of  kno«led„e 
which  my  extensive  intercourse  with  foreign  nations  aflords  . 

I  therefore  humbly  hope  that  this  work  will  prove  a  valuable  contribution 

to  the  literature  of  science,  serving —  ,,  .  „    ^.,  ,_j  Trades- 

/„  Ihe  first  place,  to  instruct  the  Manufacturer,  Metallurpst  and  ■Trades^ 

man,  in  the  principles  of  their  respective  processes,  so  as  to  render  them  m 


PREFACE.  ▼ 

reality  the  masters  of  their  business,  and  to  emancipate  them  from  a  state 
of  bondage  to  such  as  are  too  commonly  the  slaves  of  blmd  prejudice  and 

"^X^XTo  afford  to  Merchants,  Brokers,  Drysalters,  Druggists,  and 
Officers  of  the  Revenue,  characteristic  descriptions  of  the  commodities  which 
nass  throusfh  their  hands.  -    ,       -  a 

^  Tkirdlv%y  exhibiting  some  of  the  finest  developments  of  chemistry  and 
physics,  to  lay  open  an  ixcellent  practical  school  to  students  of  these  kindred 

*"lv^rtWv,-to  teach  Capitalists,  who  may  be  desirous  of  placing  their  funds 
in  some  productive  bank  of  industry,  to  select  judiciously  among  plausible 

1  *  4, 

""  ^WMv]  to  enable  Gentlemen  of  the  Law  to  become  well  acquainted  with 
the  nature  of  those  patent  schemes  which  are  so  apt  to  give  rise  to  litigation. 

Sixthly,  to  present  to  our  Legislators  such  a  clear  exposition  of  our  staple 
manufactures,  as  may  dissuade  them  from  enacting  laws  which  obstruct 
industry,  or  cherish  one  branch  of  it  to  the  injury  of  many  others  :  and 

Lastly  to  give  the  General  Reader,  intent  chiefly  on  intellectual  cultivation, 
a  view  of  many  of  the  noblest  achievements  of  science,  m  effectmg  those 
grand  transforr^ations  of  matter  to  which  Great  Britain  owes  her  paramount 
wealth,  rank,  and  power  among  the  kingdoms. 

The  latest  statistics  of  every  important  object  of  manufacture  is  gjiven  from 
the  best,  and,  usually,  from  official  authority,  at  the  end  of  each  article. 

The  following   summary  of  our   manufactures   is  extracted  from  Mr 
Macqueen^s  General  Statistics  of  the  British  Empire,  pubhshed  in  1836.    It 
shows  the  amount  of  capital  embarked  in  the  various  departments  of  manu- 
/acturing  industry,  and  of  the  returns  of  that  capital  :— 


Cotton  manufactures 

Woollen      ditto 

Silk  ditto 

Linen  ditto 

Leather      ditto  -    ,  - 

Iron  ditto,  to  making  pig  ux)n 

Iron,  hardware,  cutler}',  &c. 

Copper  and  brass  ditto 

China,  glass,  &c.       .        -        - 

Paper,  furniture,  books,  &c. 

Spirits  (British),  ales,  soap,  &c. 

Sundries  additional    - 


Capital. 


£ 
40,973,872 
36,000,000 
8,000,000 
12,000,000 
13,000,000 
10,000,000 
25,000,000 
3,600,000 
8,600,000 
10,000,000 
37,600,000 


Prodoce. 


£ 
52,513,586 
44,250.000 
10,000,000 
15,421,186 
16,000,000 

7,098,000 
31,072,600 

4,673,186 
10,892,794 
14,000,000 
47,163,847 

9,000,000 


Totals 


201,773,872    \    262,085,199    | 


Although  I  am  conscious  of  having  used  much  diligence  for  many  years  in 
collecting  information  for  this  work,  from  every  quarter  within  my  re^^M^^^^ 
utmost  pains  in  preparing  it  for  publication,  and  incessant  v^f '^"^f  .f  "'^g  j^? 
passage  trough  the'preS,  yet  I  am  fully  aware  that  ^  . ^^^^^^^^^^^^ 
errorTand  defects.    These  I  have  studied  to  rectify  in  the  text  of  this  fourth 

""^''sTnce  this  book  is  not  a  Methodical  Treatise,  but  a  Dictionary,  one  exten^ 
sive  subject  may  be  necessarily  dispersed  through  many  articles.     Ihus,  for 

♦  Tlie  statistics  ofagricuUure,  trade,  and  manufacture.,  are  ably  and  fairly  discu^ed 
in  Mr.  McCulloch's  Dictionary/  already  referred  to. 


VI 


PREFACE. 


*        i: 


example,  information  upon  the  manufacture  of  Colors  will  be  found  under 
azure ;  black  pigment ;  bone-black  ;  bronze ;  brown  dye ;  calico-printing ; 
carmine  ;  carthamus ;  chromium  ;  cochineal ;  crayons ;  dyeing ;  enamels ; 
gold;  gilding;  gamboge;  gray  dye;  green  dye;  green  paints;  indigo; 
kermes;  lac  dye;  lakes;  madder;  massicot;  mercury,  periodide  of;  Naples 
yellow;  orange  dye;  orpiment;  paints,  grinding  of;  ochres;  paper-hang- 
ings ;  pastes  ;  pearl  white ;  Persian  benies ;  pottery  pigments  ;  Prussian  blue ; 
purple  of  Cassius ;  red  lead ;  rouge  ;  Scheele's  green  ;  Schweinfurth  green ; 
stained  glass;  terra  di  Sienna;  ultramarine;  umber;  verditer;  vermilion; 
vitrifiable  colors,  weld,  white  lead  ;  woad,  yellow  king's. 

A  casual  consulter  of  the  Dictionary,  who  did  not  advert  to  this  distri- 
bution, might  surmise  it  to  be  most  deficient,  where  it  is  in  reality  most 
copious. 

The  elaborate  and  costly  Encyclopedias  and  Dictionaries  of  Arts,  which 
have  appeared  from  time  to  time  in  this  countiy  and  abroad,  have,  for  the 
most  part,  treated  of  the  mechanical  manufactures  more  fully  and  correctly 
than  of  the  chemical.  The  operations  of  the  former  are,  in  fact,  tolerably  ob- 
vious and  accessible  to  the  inspection  of  the  curious ;  nor  are  they  difficult  to 
transfer  into  a  book,  with  the  aid  of  a  draughtsman,  even  by  a  person  but  mode- 
rately versed  in  their  principles.  But  those  of  the  latter  are  not  unfrequently 
involved  in  complicated  manipulations,  and  depend,  for  their  success,  upon  a 
delicate  play  of  affinities,  not  to  be  understood  without  an  operative  familiarity 
with  the  processes  themselves.  Having  enjoyed  the  best  opportunities  of 
studying  the  chemical  arts  upon  the  greatest  scale,  in  this  kingdom  and  on 
the  Continent,  I  may  venture,  without  the  imputation  of  arrogance,  to  claim 
for  my  work,  in  this  respect,  more  precision  and  copiousness  than  its  prede- 
cessors possess.  I  have  gone  as  far  in  describing  several  curious  procease* 
hitherto  veiled  in  mystery,  as  I  felt  warranted,  without  breach  of  confidence, 
to  go ;  regarding  it  as  a  sacred  duty  never  to  publish  any  secret  whatever, 
without  the  consent  of  its  proprietor.  During  my  numerous  tours  through 
the  factory  districts  of  Great  Britain,  France,  Belgium,  Germany,  and  Switzer- 
land, many  suggestions,  however,  have  been  presented  to  my  mind,  which  I 
am  quite  at  liberty  to  communicate  in  private,  or  carry  into  execution,  in 
other  districts  too  remote  to  excite  injurious  competition  against  the  original 
inventors.  I  am  also  possessed  of  many  plans  of  constructing  manufactories, 
of  which  the  limits  of  these  volumes  did  not  permit  me  to  avail  myself,  but 
which  I  am  ready  to  furnish,  upon  moderate  terms,  to  proper  applicants. 
May  I  venture  to  point  attention  to  the  very  insecure  tenure  by  which  patents 
for  chemical  or  chemico-mechanical  inventions  are  held ;  of  which  there  is 
hardly  one  on  record  which  may  not  be  readily  invaded  by  a  person  skilled 
in  the  resources  of  practical  chemistry,  or  which  could  stand  the  ordeal  of  a 
court  of  law,  directed  by  an  experienced  chemist.  The  specifications  of 
such  patents  stand  in  need  of  a  thorough  reform  ;  being  for  the  most  part  not 
only  discreditable  and  delusive  to  the  patentees,  but  calculated  to  involve 
them  in  one  of  the  greatest  of  evils — a  chancery  suit 

While  I  gratefully  acknowledge  the  indulgence  with  which  this  work  has 
been  received,  may  I  be  permitted  to  advert  very  briefly  to  some  of  my  pre- 
sent endeavours  to  render  it  less  undeserving  of  public  favor,  though,  after  all 
my  etforts,  it  will  by  no  means  realize  either  my  own  wishes  and  intentions, 
or  the  expectations  of  all  my  readers? 

To  investigate  thoroughly  any  single  branch  of  art,  we  should  examine  it 
in  its  origin,  objects,  connexion  with  kindred  arts,  its  progressive  advance- 
ment, latest  improved  state,  and  theoretical   perfection.     The  general  princi 
pies  on  which  it  is  founded,  whether  belonging  to  the  mechanical,  the  physical, 


PREFACE. 


vu 


\ 


I 


t 


i 


the  chemical  sciences,  or  to  natural  history,  should  be  fully  expounded,  and 
tested  by  an  application  to  its  practical  working  on  the  great  scale.  The  max- 
imum effect  of  the  machinery  which  it  employs,  and  the  maximum  product 
of  the  chemical  mixtures  and  operations  which  it  involves,  should  in  every  case 
be  calculated  and  compared  with  the  actual  results. 

Such  have  been  my  motives  in  the  numerous  consultations  I  have  had 
with  manufacturers  relatively  to  the  establishment  or  amelioration  of  their  fac- 
tories ;  and  when  they  a»e  kept  steadily  in  view,  they  seldom  fail  to  disclose 
whatever  is  erroneous  or  defective,  and  thereby  lead  to  improvement  It 
will  not  be  denied  by  any  one  conversant  with  the  productive  arts,  that  very 
few  of  them  have  been  either  cultivated  or  described  in  this  spirit  It  is  to  be 
hoped,  however,  that  the  period  is  not  remote,  under  the  intellectual  excite- 
ment and  emulation  now  so  prevalent  in  a  peaceful  world,  when  manu- 
factories will  be  erected,  and  conducted  upon  the  most  rational  and  economi- 
cal principles,  for  the  common  benefit  of  mankind.  Meanwhile  it  is  the  duty 
of  every  professor  of  practical  science  to  contribute  his  mite  towards  this  de- 
sirable consummation. 

It  is  under  a  sense  of  this  responsibility  that  I  have  written  the  leading 
articles  of  this  edition,  having  enjoyed  some  peculiar  advantages  in  my  profes- 
sion for  making  the  requisite  researches  and  comparisons.  I  trust  that  not 
many  of  them  deserve  to  be  regarded  as  trite  compilations  or  as  frivolous  nov- 
elties, with  the  exception  of  a  few  of  the  notices  of  recent  patents,  which  I 
have  intentionally  exhibited  as  beacons  to  deter  from  the  treacherous  quick- 
sands, not  as  lights  to  friendly  havens.  I  have  sought  sincerely  to  make 
them  all  conducive,  more  or  less,  to  utility;  being  either  new  contributions  to 
the  old  stock  of  knowledge,  or  additions  and  corrections  to  the  present  double 
volume. 

Manufacture  is  a  word  which,  in  the  vicissitude  of  language,  has  come 
to  signify  the  revei-se  of  its  literal  intrinsic  meaning  ;  for  it  now  denotes  every 
extensive  product  of  art  which  is  made  by  machinery,  with  little  or  no  aid  of 
the  human  hand ;  so  that  the  most  perfect  manufacture  is  that  which  dispenses 
entirely  with  manual  labor. 

In  every  well-governed  state  of  continental  Europe  there  exists  a  Board 
of  Health,  or  Cornell  de  Saluhrite  composed  of  eminent  physicians,  chemists, 
and  engineers,  appointed  to  watch  over  whatever  may  aft'ect  injuriously  the 
public  health  and  comfort  In  France,  this  commission  consists,  for  the  capi- 
tal, of  seven  membei-s,  who  have  the  surveillance',  in  this  respect,  of  markets, 
factories,  places  of  public  amusement,  bakeries,  shambles,  secret  medicines, 
<fec.  This  tribunal  has  discharged  its  functions  to  the  entire  satisfaction  of 
their  fellow  citizens,  as  appears  from  the  following  authentic  report : — "  Non 
seulemeut  une  foule  de  causes  d'insalubrite  disparurent,  mais  beaucotip  de 
moycns^  de  procedes  nouveawx  furent  proposes  pour  assainir  les  Arts  et  les 
Metiers,  qui  jusqus  Id  avaient  part  inseparables  de  ces  causes  d'insalubrite  ; 
la  plupart  de  ces  moyens  eurent  un  plein  succds.  H  n^y  a  pas  d\'xemple  que 
les  mcmhres  du  Conseil  appelles,  a  donner  leur  avis  sur  les  plaintes  formees 
contre  des  fabriques,  aient  jamais  repondu  qiCil  fallait  les  supprimer  sans 
avoir  cherche  eux-memes  a  aplanir  les  difficulties,  que  presentait  aux  fabri- 
cants,  Vassainissemcnt  de  leur  art,  et  presque  toujours  ils  sont  parvenu  a  re. 
soudre  le  probUme.  Le  Conseil  de  Salubrite,  que  Von  ne  saurait  trop  sig- 
naler  a  la  reconnaissance  du  publique,  est  une  institution  que  les  nations  ^tran- 
geres  admircnt,  et  s'efforceront  d'imiter  sans  doute.^^ 

From  this  confident  hope  of  emulation  by  other  nations,  the  author  of 
these  excellent  observations  would  have  excepted  the  United  Kingdom,  had 
he  known  how  little  paternal  care  is  felt  by  the  government  for  the  general 
interests  of  the  people.     In  Germany,  indeed,  where  the  fatherland  feel  in  o-  is 


Tiii 


PREFACE. 


strong  in  the  breasts  even  of  those  rulers  whom  we  are  apt  to  consider  despots, 
similar  boards  of  health  are  universally  established,  whereas  our  legislative 
oKgarchy  frames  laws  chiefly  for  the  benefit  of  its  own  class  and  d^ndents ; 
as  happened  in  the  old  time,  when  there  was  no  king  in  Israel  to  regard  alike 
the  interests  of  the  poor  and  the  rich. 

The  Prussian  municipal  law  (Allgemeine  Landrecht)  contains  the  follow- 
ing enactments  with  regard  to  the  sale  of  spoiled  or  adulterated  victuals.  Th. 
II.  Tit  20.;  Abschnitt  11,  §§  722  to  Y25.  *'No  person  shall  knowingly  sell 
Or  communicate  to  other  persons  for  their  use,  articles  of  food  or  drink  which 
possess  properties  prejudicial  to  health  under  a  penalty  of  fine  or  bodily  pun- 
ishment Whosoever  adulterates  any  such  victuals  in  any  manner  prejudicial 
to  health,  or  mixes  them  with  unwholesome  materials,  especially  by  adding 
any  preparation  of  lead  to  liquors,  shall,  according  to  the  circumstances  of  the 
case,  and  the  degree  of  danger  to  health,  be  liable  to  imprisonment  in  a  cor- 
rection house,  or  in  a  fortress,  during  a  period  varying  from  one  to  three  years. 
Besides  this  punishment,  those  who  are  found  guilty  of  knowingly  sellinfy 
victuals  which  are  damaged  or  spoiled  (verdorbener)^  or  mixed  with  deleteri- 
ous additions,  shall  be  rendered  incapable  for  ever  of  carrying  on  the  same 
branch  of  business.  The  articles  in  question  shall  be  destroyed  if  incorrigibly 
bad,  but  if  otherwise,  they  are  to  be  improved  as  far  as  possible  at  the  cost  of 
the  culprit,  and  then  confiscated  for  the  benefit  of  the  poor.  Further,  whoso- 
ever mixes  victuals  or  other  goods  with  foreign  materials,  for  the  purpose  of 
increasing  their  weight  or  bulk,  or  their  seeming  good  qualities,  in  a  deceitful 
manner,  shall  be  punished  as  a  swindler." 

It  is  singular  how,  amid  the  law-making  mania  which  has  actuated  our 
senators  for  many  sessions,  that  not  even  one  bill  has  been  framed  for  the  pro- 
tection of  the  people  from  spoiled  and  adulterated  foods  and  drinks."* 

Many  novelties  of  an  interesting  and  useful  nature,  first  displayed  in  the 
late  Grand  Exhibition  of  the  Industry  of  all  Nations,  which  had  not  been  noticed 
in  the  alphabetical  places  as  patent  or  other  inventions,  are  here  described 
with  merited  commendation ;  though  at  the  hazard,  sometimes,  of  a  little  re- 
petition. This  valuable  portion  of  the  Dictionary  was  accomplished  with  the 
aid  of  the  able  abstracts  made  by  the  ingenious  authors  of  a  series  of 
articles  inserted  in  successive  numbers  of  "Newton's  London  Journal  of 
Science." 

The  candid  critic  will  take  into  view  the  number  of  original  disertations 
now  introduced,  and  treated  at  considerable  length.  On  comparing  these 
with  the  usual  staple  with  which  similar  books  are  made  up,  he  will  recog- 
nize my  diligence  at  least,  and  make  allowance  for  a  few  oversights.  He  will 
see,  that  having  fully  availed  myself  of  the  facilities  oflfered  by  the  alphabeti- 
cal distribution  of  the  subjects,  I  have  been  able  to  amend,  under  an  equivalent 
title,  what  seemed  amiss  under  the  main  head.  Thus,  for  example,  the  ele- 
gant new  art,  for  which  we  are  indebted  to  Daguerre,  may  be  considered  in 
connection  with  his  name,  as  also  under  the  title  Photography,  or  better  per- 
haps under  that  of  Heliography,  or  Sun-painting;  since  the  solar  rays  are  the 
preferable  excitant.  As  it  has  been  also  termed  Calotype,  under  this  name 
Sun-painting  has  been  briefly  noticed. 

In  the  mechanical  department  of  the  Dictionary,  I  have  received  valuable 
contributions  from  the  two  distinguished  engineers,  Mr.  William  and  Mr. 
Peter  Fairbaim,  brothers.  The  first  is  generally  recognized  all  over  the  fac- 
tory world  as  eminent  for  the  originality,  grandeur,  and  justness  of  his  inven- 
tions. It  has  been  my  good  fortune  to  be  conversant  with  his  magnificent 
workshops,  in  Manchester  and  Millwall,  during  very  many  years,  and  I  have 

*See  the  article  "Provisions,  Preskbvkd.** 


) 


I 


} 


PREFACE.  JK 

always  regjirded  them  as  the  best  mechanical  schools  in  the  kingdom.  Mr. 
Fairbairn  commenced  his  brilliant  career  as  a  factory  millwright,  by  discard- 
ing the  heavy  and  clumsy  square  shafts  and  drums  of  Arkwright  and  his  com- 
peers, and  replacing  them  by  slender  rods  of  wrought-ii-on,  and  cast-iron 
pulleys ;  causing  these  to  revolve  with  such  a  velocity  as  fully  compensated 
for  their  diminished  weight,  according  to  the  true  principles  of  dynamics.  He 
thus  effected  an  immense  and  most  beneficial  revolution  in  factory-construc- 
tion, in  cotton,  corn,  flax  and  silk  mills ;  enabling  the  machinery  to  be  driven 
with  far  kss  power  and  greater  precision. 

His  next  important  step  was  a  general  improvement  in  mill  architecture ; 
the  construction  of  fire-proof  buildings ;  as  also  mounting  the  fly-wheels  of 
steam-engines,  with  teeth  on  their  periphery,  into  first  motions.  This  change 
was  condemned  by  some  millwrights  at  the  time,  but  has  since  become  general. 
The  mvestigation  of  the  strength  of  cast-iron  beams,  and  a  greatly  improved 
style  of  building,  by  the  introduction  of  pilasters  at  the  corners,  completed 
his  system  of  fire-proof  spinning  works.  This  plan  has  been  since  copied  in 
all  the  textile  factories. 

The  experiments  referred  to,  and  the  construction  of  several  iron  steam- 
boats, led  him  to  the  extensive  use  of  iron  as  as  a  material  for  shipbuilding. 
Though  Mr.  Fairbairn  was  not  the  first  to  build  iron  boats,  yet  he  and  his 
then  partner,  Mr.  Lillie,  were  the  first  to  show  how  this  material  should  be 
best  applied. 

^  'Die  system  of  working  steam-engines  expansively,  by  means  of  revolv- 
ing discs,  which  is  also  very  extensively  used,  with  the  saving  of  one  half  of 
the  fuel,  was  contrived  by  Mr.  Fairbairn  about  this  time. 

We  have  now  arrived  at  the  grand  consummation  of  his  mechanical 
genius— the  tubular  bridges  and  tubular  cranes. 

His  bridges  across  the  Conway  river  and  the  sea  straits  of  Menai  are  such 
stupendous  and  marvellous  creations  of  engineering  enterprize,  as  to  have 
cast  all  former  mechanical  exploits  into  the  shade,  and  to  have  led  to  the 
notion  that  nothing  of  a  like  description  was  ever  undertaken  or  executed  by 
him.  Hence,  perhaps  I  may  be  blamed  for  using  the  expression  Fairbaim's 
lubular  Bridges.  I<ifty-two  tubular  bridges  have  been  already  erected  in  this 
and  other  countries  by  this  unparalleled  Ponti/ex  Maximus. 

In  fact,  Mr  Fairbairn's  title  to  the  honor  of  inventing  the  genuine  rectan- 
gular tubular  bndge  not  the  spurious  cylindrical  or  elliptic  form,  is  as  clear 
^  that  of  Sir  Isaac  Newton  to  the  invention  of  the  binomial  theorem,  or  Sir 
H.  Davy  to  that  of  the  miners'  safety  lamp. 

1  IJ'a}  "'^^^^^^»  ^^^^1  ™y  i-eaders,  to  Peter  Fairbairn,  Esq.,  of  Leeds,  un- 
doubtedly the  great  and  the  best  mknufacturer  of  flax  machinery  and  flax 
mi  Is,  for  the  article  Flax.  He  has  been  ably  assisted  by  the  engineer 
ot  Ills  princely  establishment,  and  especially  by  Mr.  Robert  Busk. 

Many  most  ingenious  and  instructive  disquisitions  are  due  to  my  worthy 
chemical  friend,  Mr.  Lewis  Thompson,  and  that  particularly  under  the  head 
OOAL,  m  the  body  of  the  work ;  and  in  the  following  few  remarks.  That 
there  is  nothing  personal  in  the  language  is  clear  from  this,  that  it  is  an  exact 
transcript  of  the  original  Government  Report 

Few  persons  at  all  alive  to  the  enormous  importance  of  the  question  at 
issue  will  consider  it  possible  to  be  too  critical  in  a  matter  so  notoriously  as- 
sociated with  our  national  power,  welfare,  and  prosperity.  After  all,  how- 
ever the  remarks  must  speak  for  themselves.  Nevertheless,  lest  their  merits 
snould  be  called  in  question,  it  becomes  necessary  to  demonstrate,  not  only 
that  they  are  correct  and  just,  but  that  even  the  gentlemen  engaged  in  XhL 
coal  investigation  themselves  bear  evidence  to  the  scientific  accurSjy  of  those 


I  I    ! 


«  PREFACE. 

very  remarks,  and  have  actually  modified  their  subsequent  reports  in  accord- 
ance with  the  principles  there  first  developed.  But  over  and  beyond  all  this, 
it  will  now  be  shown,  from  practical  results  obtained  during  many  years  by 
the  most  impartial  experimentalists,  that  the  views  there  displayed  respecting 
the  calorific  power  of  fuel  are  strictly  in  accordance  with  facts  of  the  most  ob- 
vious and  certain  nature,  and  should  lead  to  a  vast  economy  in  steam  navi- 
gation. 

Without  needlessly  dilating  therefore  upon  the  value  of  the  evidence  now 
about  to  be  given,  I  shall  at  once  proceed  to  offer  the  evidence  itself,  and 
leave  the  public  to  draw  an  unbiassed  conclusion. 

In  the  first  Admiralty  Report  it  was  attempted  to  be  proved  "  that  the 
evaporative  value  of  a  bituminous  coal  is  expressed  by  the  evaporative  value  of 
its  coke,  the  heat  of  combustion  of  its  volatile  products  proving  in  practice 
little  more  than  that  necessary  to  volatilize  them."  And  this  foregone  con- 
clusion was  found  to  be  verified  by  column  B.  of  Table  VI.,  which  proved 
"  that,  notwithstanding  several  striking  exceptions  which  might  have  been  ex- 
pected, the  experiments  on  the  whole  show  the  work  capable  of  being  per- 
formed by  the  coke  alone  is  actually  greater  than  that  obtained  by  experi- 
ments with  the  original  coal." 

Again,  as  regards  the  nitrogen  contained  in  coal,  it  was  asserted,  that  the 
whole  system  of  manufacturing  coke  is  at  present  very  defective ;  that  "  an 
immense  quantity  of  ammonia  is  lost  by  been  thrown  into  the  atmosphere ;" 
and  that  "  by  a  construction  of  the  most  simple  kind,  the  coke  ovens  now  in 
use  might  be  made  to  economize  much  of  the  nitrogen  which  invariably  es- 
capes in  the  form  of  ammonia."  And  accordingly  a  column  of  Table  VI.  was 
set  apart  for  the  purpose  of  rousing  the  dormant  energies  of  coke  makers  by 
showing  "the  amount  of  sulphate  of  ammonia"  which,  "  by  a  construction  of 
the  most  simple  kind,"  they  could  get  from  the  coals. 

Again,  it  was  laid  down,  that  it  is  easy  from  analysis  to  examine  whether 
tlie  duty  performed  by  the  coal  is  to  be  attributed  to  its  fixed  ingredients  (in- 
gredient ?)  or  coke ;"  and  hence  a  column  in  Table  VI.  was  given  to  show  the 
theoretical  "  number  of  lbs.  of  water  convertible  into  steam  by  the  coke  left 
by  the  coal." 

Again,  in  the  First  Report,  "  the  area  of  the  damper  open  "  was  for  the 
most  part  kept  uniform  in  different  trials  with  the  same  coal ;  as,  for  example, 
with  the  Penterfelin,  the  Duffryn,  Wards  Fiery  vein,  the  Binea,  the  Llangen- 
neck,  the  Mynydd  Newydd,  the  Graigola,  &c.  &c.  &c.,  a  change  in  the  area 
being  the  exception.  Now  in  all  these  respects  the  Reports  No.  2.  and  3.  dif- 
fer entirely  from  Report  No.  1.,  as  also  in  respect  to  certain  proximate  analy- 
ses which  were  contained  in  No.  1.  Report 

The  "  theoretical  lbs.  of  water  convertible  into  steam  by  the  coke "  have 
disappeared  ;  the  ammonia  and  sulphate  of  ammonia  to  be  got  by  "  a  con- 
struction of  the  most  simple  kind  "  have  disappeared ;  the  proximate  analyses 
have  disappeared ;  the  foregone  conclusion  respecting  the  coke  of  bituminous 
coal  has  not  only  disappeared,  but  met  with  a  direct  negative  answer  upon 
practical  trial ;  "  the  area  of  the  damper  open  "  has  been  never  twice  alike  with 
the  same  coal,  nay  the  very  litharge  experiments  have  been  arranged  so  as  to 
compensale  for  the  errors  arising  from  iron  pyrites ;  and  lastly,  we  find  that  it 
is  not  only  not  "  easy  from  the  analysis  to  examine,"  <fec.,  but  even  the  calorific 
coke  theory  is  abandoned  in  Report  No.  3.,  for  it  there  appears  that  the  ana- 
lyses show  generally  that,  although  the  "  quantities  of  carbon  and  hydrogen 
regulate  materially  the  economic  values  of  the  coals,"  yet  in  spite  of  these  ana- 
lyses "  the  inquiry  would  have  been  far  from  suflicient,  had  we  not  elicited 
the  economic  values  of  the  coals  by  actual  trial  under  the  boilers," — a  result 


i  i 


PREFACE.  li 

not  varying  much  from  our  former  dictum,  that  "  a  good  stoker  was  of  more 
importance  than  a  scientific  chemist  for  such  an  investigation."  And  how 
in  fact  can  it  be  otherwise,  when  we  find  that  the  analyses  were  made  on 
such  a  scale  that "  more  accurate  results  were  obtained  by  operating  upon 
three  or  four  grains  than  upon  a  larger  quantity ! ! " 

The  great  principle  contended  for  in  our  previous  remarks  was  that  the 
volatile  constituents  of  a  bituminous  coal,  so  far  from  being  worthless  in  a 
calorific  point  of  view,  were  on  the  contrary  of  the  greatest  importance.  Now 
this,  though  in  direct  opposition  to  the  deductions  of  Report  No.  1,  can  be 
proved  to  demonstration  from  the  results  of  Report  No.  2. ;  and  hence  no 
doubt  the  reason  why  we  find  in  Report  No.  3  that  the  quantities  of  carbon 
and  hydrogen  regulate  materially,  <fec.  At  page  45  of  Report  No.  2,  a  com- 
parative experiment  is  recorded  for  the  purpose  of  determining  whether  the 
coke  of  a  bituminous  coal  or  the  coal  itself  possessed  the  greatest  evaporative 
power ;  for  as  we  have  seen  in  Report  No.  1,  the  "  work  capable  of  being 
performed  by  the  coke  alone  was  actually  greater  than  that  obtained  with  the 
original  coal."  The  coal  employed  in  this  experiment  was  the  Tanfield,  and 
it  yielded  65  per  cent,  of  coke  ;  the  coke  was  made  from  the  same  coal  by 
Messrs.  Cory  &  Son,  of  New  Barge  House,  Lambeth,  names  too  well  known 
for  the  excellence  of  their  manufacture  to  require  comment  here.  The  ex- 
periments were  carried  on  for  34  consecutive  hours  with  each  material,  and 
the  total  amount  of  water  evaporated  was  33,1*70  lbs.  or  about  15  tons.  So 
far,  however,  from  finding  that  "  the  evaporative  value  of  a  coal  is  expressed 
by  the  evaporative  value  of  its  coke,"  which  in  this  case  was  65  per  cent, 
only,  lo !  the  experiments  prove  that  the  evaporative  power  of  the  coal  was 
20*1  per  cent  greater,  weight  for  weight,  than  that  of  the  coke,  or  about  50 
per  cent !  greater  than  its  own  amount  of  coke ! ! — thus  showing  that  the  35 
per  cent  of  volatile  ingredients  were  absolutely  equal  in  heating  power  to  the 
whole  of  the  coke ! ! !  And  strange  to  say,  this  is  borne  out  exactly  by  the 
results  obtained  in  the  manufacture  of  gas,  in  which,  as  is  quite  notorious, 
each  gallon  of  tar,  weighing  from  10^  to  11  lbs.  is  found  to  have  a  calorific 
power  equal  to  half  a  bushel  of  coke  weighing  from  21  to  23  lbs.  There  is 
not  a  gas  engineer  in  Great  Britain  ignorant  of  this  important  fact,  nor  the 
secretary  of  a  gas  works,  who,  with  coke  at  4c?.  per  bushel,  estimates  coal 
tar  as  fuel  at  less  than  2\d.  per  gallon ;  and  we  happen  to  have  now  before 
us  a  series  of  actual  workings  extending  over  very  long  periods  of  time  since 
the  year  1831,  and  made  by  the  engineer  of  the  largest  gas  works  in  the 
world,  for  the  express  purpose  of  ascertaining  the  practical  details  connected 
with  the  relative  economy  of  coal  tar,  coal  and  coke,  and  from  which  we  have 
deduced  the  following,  as  the  average  values  of  these  combustibles  expressed 
in  pounds  of  coal  carbonized  or  distilled  by  the  same  weight  of  each ; — 


Tar  equal 

Newcastle  coal  equal 
Coke  from  do.  equal 


5  lbs 

-    4ilb8. 

8|lbs. 


the  "  breeze  "  employed  with  the  tar  being  deducted  and  estimated  as  equal 
to  ^ths  of  its  weight  of  coke. 

In  point  of  fact,  however,  the  relative  value  of  coal  and  coke  may  be  more 
decidedly  determined  by  examining  the  heating  power  of  the  whole  of  the 
products  of  a  ton  of  coal,  and  deducting  therefrom  the  fuel  employed  in  the 
distillation.  For  example,  a  ton  of  Newcastle  coal  may  be  distilled  practi- 
cally by  11  bushels  of  its  own  coke,  and  it  will  then  yield  about  36  bushels 
of  coke,  4  bushels  of  breeze,  10  gallons  of  tar,  and  9500  cubic  feet  of  gas  of 
specific  gravity  •400.     Consequently  the  heating  power  of  the  tar  and  gas 


xu 


PREFACE. 


PREFACE. 


xiu 


fl 


taken  together  ought,  upon  the  hypothesis  assumed  in  the  Admiralty  Report 
No.  1,  to  be  equal  only  to  that  of  11  bushels  of  coke,  "  the  heat  of  the  volatile 
products,  (fee,  being  only  sufficient  to  volatilize  them."  Now  it  has  been  demon- 
strated over  and  over  again,  that  every  cubic  foot  of  the  aforesaid  gas  will 
practically  boil  off  2960  grs.  of  water,  therefore  9500  cubic  feet  will  boil  off 
4000  lbs.  of  water. 

But  since  the  11  bushels  of  coke  employed  in  carbonizing  the  coal  weigh 
only  about  460  lbs.,  and  the  evaporative  value  even  of  the  best  oven  coke, 
according  to  the  Admiralty  Coals  Report,  is  only  7*91  for  every  lb.  (vide 
page  46,  Report  No.  2),  it  follows  that  the  11  bushels  in  question  would  only 
evaporate  3538  lbs.  of  water,  or  less  by  462  lbs.  than  the  gas  alone,  without 
taking  into  account  the  evaporative  power  of  the  10  gallons  of  tar,  and  which 
eannot  be  assumed  at  less  than  2000  lbs.  upon  the  lowest  computation.  Con- 
sequently our  facts,  and  the  hypothesis  contained  in  the  First  Admiralty  Re- 
port stand  as  under : 

Hypothesis.  Practical  Fact?. 

One   ton  of  coals  carbonized  by  the         One  ton  of  coal  carbonized  by  11  bushels 

heat  of  its  volatile  constituents  aflfords  40     of  coke  affords  9600  cubic  feet  of  gas,  10 

bushels  or  1680  lbs.  of  coke,  equal  to  the     gallons  of  tar,   and  40  bushels   of  coke, 

evaporation  of  13,378  lbs.  of  water.  from  which  latter  11  are  to  be  deducted. 

Tlius  leaving  as  the  total  heating  power : 

Iba.  of  water. 
29  bushels,  or  1218  lbs.  of  coke  equal 

to  -  -  -  9634 

9600  cubic  feet  of  gas  equal  to    -      4000 
10  gallons  of  tar  equal  at  least  to      2000 

Total  lbs.  15,634 

or  nearly  20  per  cent,  more  than  the  coke,  a  result  which  not  only  agrees 
with  the  practical  experiments  made  with  the  Admiralty  boiler,  but  also  with 
the  statements  of  Mr.  Clegg,  who  indeed  makes  the  difference  greater,  that 
is,  21  per  cent,  in  favor  of  coal.  Mr.  Clegg,  in  the  second  edition  of  his 
practical  treatise  on  Coal  Gas,  just  published,  gives  the  following  as  the  rela- 
tive amounts  of  coal,  coke,  or  coal  tar  required  to  distil  one  chaldron  of 
eoals: 

Coal  Tar  from  24  to  27  gallons,  or  from  264  to  297  lbs. 
Coal  from  5  to  5i  cwt,  or  from  560  to  616  lbs. 
Coke  from  16  to  18  bushels,  or  from  672  to  756  lbs. 

He  also  estimates  coal  tar  at  3c?.  per  gallon. 

If  arguments  of  this  kind  do  not  conclusively  estabhsh  the  validity  of  our 
first  remarks,  we  can  scarcely  hope  to  demonstrate  any  truth  whatever ;  for 
these  conclusions  are  drawn  from  actual  data,  the  result  of  many  years  of 
labor  undertaken  by  several  different  individuals,  in  different  localities,  hav- 
ing discordant  interests  in  all  respects  but  one,  and  that  one  the  discovery  of 
the  simple  truth  with  a  view  to  practical  economy  in  fuel,  in  establishments 
where  the  fuel  accounts  annually  reach  many  thousands  of  pounds  sterling. 

If  it  be  demanded  how  it  happens  that  these  results  differ  so  materially 
from  the  great  bulk  of  those  arrived  at  by  the  Admiralty  boiler,  we  might 
very  properly  refer  the  question  to  the  fabricators  of  the  three  Admiralty  Re- 
ports ;  but  the  causes  of  that  difference  are  too  obvious  to  escape  the  niost 
guperficial  observer ;  and  therefore,  without  wearying  the  reader  by  a  tedious 
recapitulation,  we  will  merely  collate  a  few  instances  from  these  Repoits, 
which  pre  ve,  beyond  the  possibility  of  contradiction  that  the  boiler  experi- 


ments were  totally  inconclusive  even  upon  the  assumptions  of  the  experi- 
menters themselves. 

We  have  before  called  attention  to  the  want  of  varied  adjustment  in  the 
open  area  of  the  damper  in  most  of  the  experiments  in  Report  No.  1 ;  this 
objection  is  seen  very  forcibly  in  Reports  Nos.  2  and  3,  where  it  not 
unfrequently  happens  that  between  112  inches  of  area  and  66  inches,  the 
value  of  the  same  coal  is  found  to  vary  as  much  as  20  per  cent.  Such  being 
the  case,  it  is  but  reasonable  to  conclude  that  where  a  coal  has  gone  on  dur- 
ing three  experiments  increasing  in  value  as  the  open  area  of  the  damper  was 
increased,  that  the  value  of  that  coal  hys  not  been  developed  simply  because 
the  proper  extent  of  the  open  area  has  i  ot  been  reached  in  any  of  the  experi- 
ments. As  examples  where  the  area  has  been  too  small,  we  may  cite  the 
following : — 


Blackbrook  Rushy 
Park  coals 

Result 

Area. 
112 
8-62  lbs. 

7-66  lbs. 

84 

7-89  Ibe. 

Blackbrook 
Little  Delf    " 
Result 

Area. 
112 
8-67  lbs. 

Area. 
56 
81 3  Ibe. 

Area. 
84 
817  Iba. 

Johnson   and  Wir-  \ 

thington's  Rushy    > 

Park                        ) 

Result 

Area. 
112 
8-69  lbs. 

Atml 
56 
7-83  lbs. 

Area. 
US 

7-62  lbs. 

Lynvi  coal 

Result 

Area. 
112 
9-61  lbs. 

Area. 
56 
8-89  lbs. 

84 

9-08  IbiL 

Balcarras  five 
feet  nine 

Result 

Area. 
112 
7-79  lbs. 

Area. 
56 
6-60  lbs. 

Aiea. 
84 
7-23  lbs. 

Hastings  Hartley 
Result 

Area. 
112 
8-18  lbs. 

Area. 
56 
7-65  lbs. 

Area. 
84 

7-49  Iba. 

And  in  precisely  the  same  condition  are  the  Balcarras  Arley,  Carr's  Hart- 
ley, Hedley's  Hartley,  Bate's  West  Hartley,  Davison's  West  Hartley,  Cowpen 
and  Sidney  Hartley,  Hill's  Plymouth  Coals,  the  Willington  Coal,  the  Wigan 
Four  Foot  Seam,  and  a  host  of  others,  in  Report  No.  3,  all  of  which  would 
no  doubt  have  given  a  better  result  with  an  increased  opening  in  the  damper. 
Conversely,  we  find  many  others  with  too  large  an  opening,  as  for  example : 


North  Percy  ) 

Hartley  ) 

Result 

Balcarras  Haigh 
Yard  mine 

Result 


\ 


Area. 
112 

7-43  lbs. 
Ana. 
112 
6-79  lbs. 


Area. 

56 

7-74  lbs. 
Area. 

56 

8-65  lbs. 


Area. 
84 

7  54  Iba. 


84 

8-26  Ibei 


And  about  a  dozen  more  throughout  Reports  2  and  3,  in  which  the 
greatest  effect  has  been  produced  by  the  minimum  of  area,  leading  therefore 
to  the  inference  that  a  more  restrii^ted  opening  would  have  increased  the 
value  of  the  fuel.     Taken  as  a  whole,  the  only  honest  inference  that  can  be 


ziy 


PREFACE. 


1 

SI 


drawn  from  the  three  Reports  is,  that  the  question  sought  to  be  solved  by  the 
Admiralty  coal  investigation  remains  exactly  where  it  was  for  all  practical 
purposes;  the  analyses,  whether  proximate,  ultimate,  or  lithargic,  together 
with  the  boiler  experiments,  being  in  all  senses  of  the  expression  null,  void, 
and  of  no  effect  or  value  whatever. 

And  as  a  proof  of  the  little  care  taken  to  insure  accuracy  to  the  whole  per- 
formance, we  find  at  page  10,  Report  No.  3,  that  even  the  simplest  rules  of 
arithmetic  have  been  violated  in  a  Table  purporting  to  show  the  average 
composition  of  the  coals  from  Wales,  Newcastle,  Lancashire,  Scotland,  and 
Derbyshire.  This  table  gives,  or  ought  to  give,  the  composition  of  the  re- 
spective coals  in  100  parts,  and  strange  to  say,  the  results  do  not  amount  to 
100  in  any  single  instance :  the  Welsh  coal  is  more,  and  the  others  less  than 
100,  though  the  oxygen  was  calculated  from  the  loss, 

London,  18  Upper  Seymowr-ztreet^ 
IQth  June,  1853. 


\ 


t 


DICTIONARY 


•V 


ARTS,  MANUFACTURES,  AND  MINES. 


ABIETINR  A  pale  yellow,  transparent^  viscid  exudation  from  the  Abies  pectinata^ 
a  species  of  fir,  growing  in  the  neighborhood  of  Strasburg,  and  hence  called  Strasburg 
turpentine.  It  contains  35  per  cent,  of  a  volatile  oil  of  an  agreeable  smell,  combined 
with  a  resin,  and  a  small  quantity  of  the  acid  of  amber,  as  well  as  the  peculiar  body 
called  abietin,  a  resin  of  an  acid  kind,  styled  therefore  by  some  abietic  acid.  If  th« 
indifferent  resin  be  removed  by  absolute  alcohol,  and  the  remainder  digested  with 
carbonate  of  potash,  an  abietate  of  potash  is  obtained.  It  dissolves  in  petroleum,  and 
crystallizes  out  of  it.  It  resembles  Canadian  balsam,  and  is  used  for  attaching  micro- 
scopic objects  to  glass  slips. 

ACETAL,  is  the  subacetate  of  ether ;  having  for  its  chemical  symbol  3  Ac  O  -f-  A« 
Oj.     It  is  a  light  colorless  ethereous  liquid. 

ACETATE.  {Acetate,  Fr. ;  Essigsaure,  Germ.)  Any  saline  compound  of  which  the 
acetic  is  the  acid  constituent;  as  acetate  of  soda,  of  iron,  of  copper,  <fcc. 

ACETATE  OF  ALUMINA,  see  Red  Liquor  and  Mordant;  of  Copper,  see  Coppek; 
of  Iron,  see  Iron  ;  of  Lead,  see  Lead  ;  of  Lime,  see  Pyrolignous  Acid. 

ACETIC  ACID,  or,  according  to  the  new  nomenclature  of  organic  chemistry,  acetylit 
acid  hydrate,  bein^  a  compound  of  the  radical  acetyl  (Ac  C4  11,  )  and  oxygen  (Os),  with 
water  (H  OX  for  it  cannot  be  bought  in  the  dry  state.  It  is  formed  out  of  alcohol  in 
the  acetous  fernientation,  or  by  its  oxygenation  with  air ;  it  is  produced  in  the  dry 
distillation  of  most  non-volatile  organic  compounds,  as  of  wood,  gum,  starch,  Ac,  in 
the  spontaneous  decomposition  of  the  watery  solutions  of  citric  and  tartaric  acids,  as 
also  by  the  boiling  of  several  organic  substances  with  sulphuric  acid.  It  exists  ready 
formed  in  several  vegetable  and  animal  juices.     See  Geruardt. 

Alcohol  is  a  compound  which,  even  diluted  with  water  and  ex-posed  to  the  air,  is 
not  liable  to  spontaneous  change ;  but  if  in  this  state  it  is  mixed  with  yeasty  at  a  tem- 
perature of  from  60°  to  90°  Fahr,  it  absorbs  oxygen,  and  passes  into  acetic  acid.  Tb« 
oxygen  forms  first  water,  with  2  atoms  of  the  hydrogen  of  the  ethyl,  whereby  acetyl 
18  generated;  therefore  ethyloxide-hydiate  (alcohol)  becomes  acetyloxide  hydraU. 
(aldehyde),  which  by  absorption  of  two  more  atoms  of  oxygen,  constitutes  hvdrate4 
acetic  acid.  ^  =»     >  j 


1  Atom  Alcohol 
—  2  Atoms  Hydrogen 

=—  Aldehyde 
-j-  2  Atoms  Oxygen 

=      Acetic  Acid  Hyd. 


C4HBO   -f  HO 
H,    _ 

C4H,  0  -fH  O 
Oa 

C4  H,  O,  4-  H  O. 


Ite  atomic  weight  on  the  hydrogen  scale  is  therefore  60  in  the  state  of  hydrate,  and 

.  Albumen,  gluten,  and  vegetable  matters  which  contain  these  substances,  such  as  th« 
juice  of  beet-roots,  operate  also  the  oxidation  of  alcohol,  and  that  the  more  rapidly 
the  more  ample  the  exposure  of  the  mixture  to  the  air.  While  sugar  is  transmuted 
into  carbonic  acid,  and  alcohol  only  through  the  intervention  of  gluten,  alcohol  sul^ 
fers  that  change  by  contact  with  finely  divided  platinum.  It  is  hince  probable,  that 
to  what  is  called  acetous  fermentation,  the  vital  action  of  the  particles  of  yeast  is  not 
indispensable,  and  that  it  belongs  rather  to  the  category  of  chemical  combustion  •  to 
the  contact  action  ofLiebig,  the  catalysis  ofBerzelius,  or  %U  polar  cmnlnnation  ofLihoia. 
In  the  vinegar  of  wine,  malt,  or  that  in  which  organic  matter  has  been  infused 
there  appears  a  peculiar  mould-plant,  belonging  to  the  genua  Mycodemia  Pers.-  whiS 
IS  usuaUy  called  vinegar  mother.     As  the  plant  grows,  it  decomposes  the  acid,  aad 


8  ACETIC  ACID. 

leaves  eventually  nothing  but  water.     It  contains  proteine,  and  consequently  azote, 
but  leaves  no  ashes  when  burned.  «    i     i    i  • 

The  same  circumstances  which  govern  the  conversion  of  alcohol  mto  vinegar,  pre- 
side over  that  of  wood  spii  it  into  formic  acid  (acid  of  ants),  fusel  oil  (oil  of  grain)  mto 
valerianic  acid ;  and  probably  butyric  acid  has  some  such  organ.  With  regard  to  the 
formation  of  vinegar,  M.  Dumas  observes  that  every  fermentation  has  for  its  effect  to 
dissociate  a  compound  into  a  more  simple  state ;  but  the  so-called  acetous  fermenta- 
tion unites  alcohol  or  aldehyde  with  the  oxygen  of  the  air;  being  the  ouly  case  in 
which  fermentation  represents  a  true  combination.  He  admits,  notwithstanding,  that 
this  fermentation,  in  a  certain  point  of  view,  possesses  the  character  of  the  other  fer- 
mentive  actions,  namely,  the  concourse  of  an  organized  substance,  and  of  an  organic 
matter;  the  one  being  a  ferment  (the  mother),  and  the  other  fermentable.  The  con- 
version of  alcohol  into  vinegar  never  happens  in  common  cases,  without  the  aid  of  an 
albuminous  substance,  and  of  circumstances  favorable  to  all  fermentations,  such  as 
the  presence  of  air,  not  only  at  its  commencement,  but  during  its  entire  course. 

The  lactic  fermentation  has  however  been  sometimes  mistaken  for  the  acetous;  but 
it  may  be  distinguished  by  its  requiring  no  alcohol,  but  only  starchy  or  saccharine 
matters ;  and  after  it  begins,  exposure  to  air  is  not  needed.  It  has  been  supposed  that 
acetification  is  analogous  to  nitrification,  as  to  the  utility  of  porous  bodies  which  di- 
vide the  liquid  and  the  air ;  thus  ammonia  passed  along  with  air  through  platinum 
sponge,  gently  ignited  in  a  tube,  produces  nitric  acid ;  and  pumicestone,  in  like  cir- 
cumstances, combines  sulphurous  acid  and  oxygen  into  the  sulphuric  ;  and  so  we  have 
seen  that  a  mixture  of  alcohol  vapor  and  air  under  the  influence  of  the  same  sponge 
is  converted  by  a  true  oxidation  of  the  ether  (of  the  alcohol),  first  into  aldehyde,  and 
afterwards  into  acetic  acid.  A  like  oxidation  takes  place  in  the  wine  or  beer,  which 
being  purposely  left  in  casks  partially  filled,  rises  by  capillarity  on  the  wood  above 
the  liquid  level,  and  is  there  subjected  to  the  porous  influence.  The  vinegar  is  much 
more  rapidly  generated,  however,  by  the  various  artiticia)  methods  of  multiplication 
of  points  of  contact  with  the  air,  presently  to  be  described. 

Vinegars  may  be  arranged  under  four  heads :  1.  Malt  or  sugar  vinegar ;  2.  Wine 
and  fruit  vinegar ;  3.  Alcohol  vinegar ;  4.  Wood  vinegar. 

1.  Malt  vinegar  is  manufactured  most  extensively  in  the  United  Kingdom,  chiefly  in 
England,  to  the  amount  of  fully  3,000,000  of  gallons,  on  which  an  excise  duty  of  2«t 
per  gallon  is  levied,  and  for  the  license  to  manufacture  it,  5/.  annually  must  be  paid. 
The  total  number  of  vinegar  manufactories  in  this  country  is  about  fifty,  of  which  five 
of  the  principal  ones  are  in  London,  and  these  carry  on  at  the  same  time  the  manu- 
facture of  British  wines,  now  happily  emancipated  from  the  trammels  of  the  Excise. 
From  6  bushels  of  malt,  properly  crushed,  100  gallons  of  wort  in  whole  may  be  ex- 
tracted by  due  mashing,  the  first  water  of  infusion  being  of  the  temperature  of  160° 
Fahr.,  and  the  next  two  progressively  hotter,  for  exhausting  the  soluble  saccharine 
matter.     When  the  wort  is  cooled  to  75°,  from  3  to  4  gallons  of  good  yeast  are  stirred 
into  it  in  the  fermenting  tun,  and  when  it  has  been  in  brisk  fermentation  for  about  40 
hours,  it  is  racked  off  into  used  vinegar  casks,  laid  upon  their  sides  in  a  room  heated 
with  a  stove  for  quick  work ;  or  otherwise,  during  summer,  in  the  open  air,  under  ex- 
posure to  the  sun.     The  casks  should  be  only  about  |  filled,  and  left  unclosed,  or  loose- 
ly covered  from  the  rain  at  their  bung  holes,  to  favor  the  free  acidifying  action  of 
tiie  atmosphere.     In  the  air,  the  acetic  fermentation  may  not  be  completed  till  after 
the  lapse  of  three  months ;  but  in  stove-rooms  in  much  shorter  time,  according  to  the 
temperature.     The  sour  liquor  is  then  transferred  from  the  several  casks  by  means  of 
a  flexible  pipe,  and  pumped  into  the  stove-vat,  whence  it  is  run  into  the  clarifying  and 
flavoring  casks,  called  "rapes,"  being  here  made  to  filter  slowly  and  repeatedly  through 
condensed  heaps  of  the  stalks  and  skins  of  raisins,  called  rape,  which  is  the  refuse  of 
the  British  wine  manufacture.     Vinegar  thus  made  contains  always  a  considerable 
quantity  of  gluten,  and  is  therefore  liable  to  become  mouldy  and  to  putrify ;  to  coun- 
teract which,  a  certain  portion  of  sulphuric  acid  may  be  legally,  and  is  always,  mixed 
with  British-made  vinegar ;  but  that  portion  is  too  often  overpassed  through  aval  ice, 
and  is  certainly  injurious  to  health.     I  have  found  by  analysis  in  a  saniple  of  vinegar, 
made  by  one  of  the  most  eminent  London  manufacturers,  with  which  he  supplies  the 
public  no  less  than  175  grains  of  the  strongest  oil  of  vitriol  per  gallon,  added  to  vine- 
gar containing  only  SB  per  cent,  of  real  acetic  acid;  giving  it  an  apparent  strength 
after  all  of  only  4  per  cent.  ;  whereas  standard  commercial  vinegar  is  rated  at  5  per 
cent.     It  is  a  remarkable  fact,  that  the  people  of  this  country  have  had  their  vinegar 
palate  so  depraved,  that  they  prefer  the  vitriolized  vinegar  to  the  pure ;  and  that  all 
attempts  at  introducing  abetter  article  into  general  sale  has  proved  abortive,— a  fact 
discreditable  to  our  nation,  of  which  several  instances  have  come  before  me. 

The  complete  acidification  of  malt  wort  by  the  above  process  bem^  very  slow,  has 
iriven  rise  to  many  projects,  more  or  less  successful,  fov  accelerating  it  So  long  ago 
as  the  year  1824,  Mr.  Ham,  of  Norwich,  obtained  a  patent  for  exposing  worts  to  tlie 


T 


ACETIC  ACID.  .  t 

atmospheric  air  apon  a  most  extensive  surface,  by  means  of  a  revolving  pump,  which 
caused  a  constant  shower  of  it  to  fall  upon  and  through  a  bundle  of  birch  twigs 
supported  in  the  middle  of  a  large  tun.  The  air  had  free  access  to  the  twigs.  The 
wash,  being  kept  at  a  temperature  of  from  90°  to  100°  Fahr.,  by  steam  pipes  at  the 
bottom  of  the  tun,  and  continually  repumped,  became  moderately  acetified  m  48  hours, 
and  was  finished  into  good  vinegar,  either  by  that  process,  or  preferably  by  racking  off 
into  casks,  and  exposing  it  in  them  to  a  temperature  of  86°  Fahr.  for  15  or  20 
days.  He  also  found  that  a  wort  made  with  1  part  of  malt  mixed  with  6  of  raw  barley, 
properly  mashed,  afforded  by  this  means  an  excellent  vinegar.  A  wort  of  sp.  gr.  1  060 
(60  excise  gravity)  will  yield  a  vinegar  of  revenue  proof,  or  of  6  per  cent  of  real  acetie 
acid.  This  quick  process  belongs  rather  to  the  combustion  class  of  chemical  transform- 
ations than  to  that  of  the  fermentative,  as  yeast  is  not  essential,  though  it  is  found  to 
prove  serviceable,  as  in  the  corresponding  formation  of  acetic  acid  from  the  oxygena- 
tion of  alcohol  some  stale  vinegar  is  used  as  a  ferment,  or  as  a  contact  agent 

Under  Messrs.  Ham's  instructions  four  considerable  manufactories  of  vinegar  have 
been  established,  with  the  products  of  two  of  which  I  am  practically  conversant,  and  I 
am  warranted  by  experimental  proofs  in  declaring  that  the  vinegar  made  by  Messra. 
Hill,  Evans,  and  Williams,  of  Worcester,  and  Messrs.  Hills  and  Underwood,  of  Nor- 
wich and  Easteheap,  London,  are  perfect  specimens  of  acetic  acid  for  family  use,  and 
also  for  manufacturing  purposes.  The  latter  company  liberally  displayed,  in  the 
South  Gallery  of  the  Royal  Exhibition,  at  No.  7.  Class  3.  substances  used  as  food,  a 
model  of  their  acetifying  apparatus,  as  mounted  in  their  works. 

An  excellent  vinegar  may  be  made  for  domestic  purposes  by  adding  to  a  syrup  con- 
sisting of  one  pound  and  a  quarter  of  sugar  for  every  gallon  of  water,  a  quarter  of 
a  pint  of  pod  yeast  The  liquor  being  maintained  at  a  heat  of  from  75°  to  80°  Fahr, 
acetification  will  proceed  so  well  that  in  2  or  3  days  it  may  be  racked  off  from  the 
sediment  into  the  ripening  cask,  where  it  is  to  be  mixed  with  1  oz.  of  creiim  of  tartar, 
and  1  oz.  of  crushed  raisins.  When  completely  freed  from  the  sweet  taste,  it  should 
be  drawn  off  clear  into  bottles,  and  closely  corked  up.  The  juices  of  currants,  gooseber- 
ries, and  many  other  indigenous  fruits,  may  be  acetified  either  alone,  or  in  combination 
with  syrup.  Vinegar  made  by  the  above  pro<ess  from  sugar  shouM  have  fully  the 
revenue  strength.  It  will  keep  much  better  than  malt  vinegar,  on  account  of  the 
absence  of  gluten,  and  at  the  present  low  price  of  sugar  will  not  cost  more,  when 
fined  upon  beech  chips,  than  \s.  per  gallon. 

2.    Wine  vinegar  is  made  of  the  best  quality,  and  on  the  greatest  scale,  at  Orleans  in 
trance,  out  of  wines  which  have  become  more  or  less  acidulous,  and  are,  therefore,  of 
inferior  value.     When  the  viueijar  is  made  from  well-flavoured  wines,  it  is  preferable 
to  every  other  for  the  use  of  the  table.     The  old  method  pursued    in  the  vinaipreHe» 
consists  merely  in  partially  filling  a  series  of  large  casks  placed  in  3  or  4  ranges  over 
each  other  m  a  cellar  warmed  with  a  stove  to  the  temperature  of  85°  Fahr.   with  the 
wine  mixed  with   a  certain  proportion  of  ready-made  vinegar  as  a  ferment     More 
wine  IS  added  in  successive  small  portions  as  fast  as  the  first  has  become  acetified,  tak- 
ing care  that  a  free  ventilation  be  maintained,   in  order  to  replace  the    carbonic  acid 
produced  by  fresh  atmospheric  oxygen.     In  summer,  under  a  favorable  exposure  of 
tlie  windows  and  walls  of  the  fermenting  room  to  the  sun,  artificial  heat  is  not  needed. 
i^(th  cask  18  of  about  60  gallons  capacity,  and  the  whole  set  is  filled  up  J  with  vine- 
gar, to  which  2  galls,  of  wine  are  added,  and  weekly  afterwards  2  galls,  more.     About 
8  gallons  are  drawn  off  at  the  end  of  four  weeks  as  vinegar,  and  then  successive  addi- 
tions of  wine   are  made  as  before  to  the  casks.     These  are  laid  horizontally  in  rows 
upon  their  gawntrees,  and  are  pierced  at  the  upper  surface  of  the  front  end  with  two 
holes :  one,  called  the  eye,  is  two  inches  in   diameter,  and   serves  for   pourinc  in  the 
charges  through  a  tunnel ;  the  other  is  a  small  air-hole  alongside.     The  casks  should 
never  be  more  than  !  full,  otherwise  a  sufficient  body  of  air  is  not  present  in  them  for 
favouring  rapid  acetification.     At  the  end  of  a  certain  period,  the  deposit  of  tartar  and 
lees  becomes  so  great,  that  the  casks  must  be  cleared  out     This   renovation  usually 
takes  place  every  ten  years ;  but  the  casks,  when  made  of  well-seasoned  oak  and  boun'd 
with  iron  hoops  will  last  25  years.     The  wine  as  well  as  the  vine-ar  produced  should 
be  clarified  by  being  slowly  filtered  through  beech   chips  closely  packed  in  a  laro-e 
open  tun.     When  wines  are  new,  and  somewhat  saccharine,  or   too   alcoholic,  thev 
acetify  reluctantly,  and  need  the  addition  of  a  little  yeast  or  even  water  to  the  mix- 
ture; and  when  they  are  too  weak,  they  should  be  enriched  by  the  addition  of  some 
sugar  or  stronger  wme,  so  as  to  bring  them  to  a  uniform  state  for  producino-  vineear 
of  normal  strength.     To  favour  the  renewal  of  fresh  air  into  the   upper  p^rt  of  the 
hogsheads,  it  would  be  advisable  to  pierce  a  two-inch  hole  near  to  the  upper  level  ot 
the  liquid  when  the  ca^k  is  fullest,  by  which  means  the  heavy  carbonic  acid  would  faU 
out,  and  be  replaced  by  the  atmospheric  air  at  the  superior  apertures. 
1  have  had  occasion  to  examine  professionally  the  best  wine  vinegars  imported  into 


4  ACETIC  ACID. 

this  country  from  Orleans,  and  I  found  their  specific  gravity  to  be  about  1  -019,  and  their 
percentage  of  acetic  acid  hydrate  (crystalline  acid)  to  be  from  6  J  to  nearly  7.  One  or  two 
samples  were  supposed  to  contain  acetified  cider.  This  adulteration  maybe  tested  by 
neutralizing  the  vinegar  with  ammonia,  and  then  adding  solution  of  acetate  of  lime. 
Tartrate  of  lime  is  of  course  precipitated  from  the  wine  vinegar,  while  the  pearly  malic 
acid  of  the  cider  affords  no  precipitate  with  the  lime,  but  may  be  detected  by  ace- 
tate of  lead,  by  the  glistening  pearly  scales  of  malate  of  lead,  hardly  soluble  in  the  cold. 

3.  Alcohol  Vinegar. — ^This   species  has  been  hitherto  manufactured  chiefly  in  Ger- 
many, having  commenced  soon  after  Dobereiner'sfine  discovery  of  the  combustion  of 
alcohol  into  acetic   by  the  agency  of  platinum  mohr.     Under  a  large  glass  bell,  he 
placed  on  shelves,  an  inch  or  two  apart,  several  saucers,  containing  spirits  of  wine,  with 
slips  of  blotting  paper  so  suspended  as  that  their  lower  edges  dipped  in  the  spirits. 
Over  and  alongside  of  these  saucers,  other  smaller  ones  were  set,  containing  the  black 
platinum  powder  moistened  with  the  spirits.     The  apparatus  being  exposed  to  the  sun- 
shine, or  even  put  into  an  apartment  moderately  warm,  a  copious  formation  of  vapours 
takes  place,  with  a  manifest  increase  of  temperature,  and  streaks  of  condensed  fluid  run 
down  the  sides  of  the  bell  into  the  subjacent  basin.     This  fluid  is  acetic  acid,  resulting 
from  the  acidification  of  the  elements  of  the  alcohol  b3'^the  oxygen  of  the  atmospherical 
air  included.  This  interesting  transformation  ceases  with  the  exhaustion  of  the  oxygen, 
but  it  may  be  renewed  from  time  to  time  by  renovation  of  the  air.  One  atom  of  alco- 
hol =  C«  Hs  O  +  H  O  =46  parts ;  in  which  compound,  two  atoms  of  hydrogen  being 
replaced  by  two  of  oxygen,  we  have  46  -I- 14=60  parts,  or  one  atom  of  hydrated  acetic 
acid.     Hence  we  see  that  46  parts  of  absolute  alcohol  aflford  60  of  radical  vinegar ;  100 
parts  therefore  aflford  130,  and  require  for  this  conversion  nearly  VO  parts  of  oxygen,  al- 
lowing two  atoms  of  oxygen  for  the  abstraction  of  the  two  atoms  of  hydrogen.   Since  air 
m  round  numbers  contains  a  little  more  than  one  fifth  its  volume  of  oxygen,  then  1000 
cubic  inches  wil  contain  upwards  of  200  of  oxygen,  which  will  weigh  fully  70  grains, 
being  the  quantity  requisite  for  the  transformation  of  100  grains  of  alcohol  into  acolio 
acid  in  the  above  process.     Two  atoms  of  water  are  also  formed,  equal  to  18    grains. 
In  practice  it  is  found  that  weak  alcohol  answers  best     With  a  box  of  1 2  cubic  feet 
capacity,  and  with  7  or  8  ounces  of  platinum  mohr  properly  distributed,  1  lb.  of  alco- 
hol may  in  the  course  of  a  day  be  converted  into  pure  vinegar,  ft  for  every  purpose  of 
the  kitchen  or  the  chemist  I  have  examined  the  vmegar  manufactured  from  spirits,  and 
found  it  to  be  excellent  as  it  contains  no  gluten,  and  it  is  therefore  not  liable  to  change. 
It  is  not  possible  in  this  way  to  make  a  strong   acetic  acid,  nor  can   it  be  made  at  all 
on  the  large  scale  in  this  country,  on  account  of  our  revenue  laws. 

In  the  sequel  of  Dobereiner's  discovery,  another  German  chemist,  M.  Schutzenbach, 
applied  the  principle  of  oxygenation  to  beers  and  other  alcoholic  liquors,  for  the  pur- 
pose of  converting  them  rapidly  into  vinegar ;  and  about  the  same  time  M.  Wagenmann 
contrived  his  graduator,  or  essigbilder,  a  simple  apparatus  for  the  quick  vinegar  manu- 
facture. It  consists  of  an  oaken  tub  5i  feet  high,  3^  feet  wide,  and  3  feet  at  bottom,  set 
upon  a  wooden  frame  about  14  inches  from  the  floor.  Fifteen  inches  above  the  bottom, 
the  tub  is  pierced  with  a  horizontal  row  of  eight  equidistant  holes,  one  inch  in  diameter. 
Five  inches  beneath  the  mouth  of  the  tub  a  strong  beechwood  hoop  is  fastened  to  the 
inner  surface,  in  order  to  support  a  circular  oaken  shelf,  the  space  round  the  edge  of 
which  is  stuffed  tight  with  hemp.  This  shelf  is  perforated  with  at  least  400  gimlet  holes 
of  about  I  of  an  inch,  through  each  of  which  a  porous  cotton  wick  is  let  down  several 
inches,  hanging  by  a  knot  in  the  top  of  the  hole  at  its  upper  end.  In  the  same  circular 
shelf  there  are  4  holes,  IJ  inch  in  diameter,  and  18  inches  apart,  into  each  of  which  is 
fixed  tight  the  middle  of  a  stout  glass  tube  about  4  inches  long.  These  tubes  favour 
the  circulation  of  the  air  admittted  by  the  circumferential  holes.  One  inch  above  the 
bottom  of  the  tub  a  hole  is  pierced  for  the  reception  of  a  syphon  of  discharge,  the  top 
curvature  of  which  must  stand  about  1  inch  below  the  holes  in  the  side  of  the  tub,  to 
preventthe  liquor  collected,  to  the  depth  of  about  12  inchesonthe  bottom,  being  spilled. 
Into  the  empty  space  over  this  liquor,  the  bulb  of  a  thermometer  is  placed,  while  the 
stem  and  scale  project  to  show  the  interior  temperature.  Beneath  the  lower  outer  leg 
of  the  syphon  a  reception  cistern  is  set.  The  mouth  of  the  tub  has  a  w^ooden  lid,  with 
a  funnel  fixed  in  its  middle  for  the  introduction  of  the  liquor  to  be  acetified.  The  whole 
capacity  of  this  tub  from  the  bottom  up  to  within  1  or  2  inches  of  the  perforated  shelf,  is 
to  be  filled  up  with  shavings  of  beech-wood  (previously  boiled  in  water),  or  with  grape 
stalks,  or  birch-twigs,  all  well  soaked  with  vinegar.  This  apparatus  being  placed  in  an 
apartment  heated  to  from  80°  to  100°  Fahr.,  is  to  have  its  uppermost  compartment  fill- 
ed with  liquor.  This  slowly  filters  down  through  the  cotton  wick  threads,  thence  over 
the  surfaces  of  the  chips  or  stalks,  and  finally  into  the  subjacent  receiver,  having  been 
exposed  in  its  transit  very  freely  to  the  air.  The  ordinary  acetifying  mixture  consists 
of  8  parts  of  proof  spirits.  25  parts  of  river  water,  1 5  parts  of  good,  vinegar,  and  15  parts 
of  clear  beer  or  wine.  The  water  should  be  heated  to  about  150°  before  the  other  in- 
gredients are  added  to  it,  whereby  the  mixture  acquires  a  genial  temperature.   After 


ACETIC  ACID.  5 

this  has  been  all  transmitted  through  the  apparatus,  it  will  be  found  imperfectly  aceti- 
fied, and  therefore  must  be  passed  through  once  or  twice  more.  And  since  the  more  alco- 
hol that  is  present  the  slower  is  the  process,  it  is  advisable  to  keep  back  part  of  the  spi- 
rits at  first,  and  to  add  it  in  the  subsequent  transmissions.  The  wash-cistem,  which  con- 
tains the  acetifying  mixture,  should  be  supported  on  a  shelf  near  the  ceiling  of  the 
Btove-heated  apartment  in  order  to  be  kept  constantly  warm.  After  the  first  opera- 
tion is  completed,  the  interior  of  the  cask  becomes  so  active  an  oxidizer,  that  the  addi- 
tion of  vinegar  to  the  mixture  is  no  longer  necessary ;  but  care  should  always  be  taken  to 
have  it  as  well  clarified  as  possible,  in  order  to  prevent  the  depositing  of  much  gluten 
upon  the  beech-chips.  Dr.  Kastner  prescribes  the  following  manner  of  making  a  malt 
wine  for  the  quick  vinegar  process :— Crush  together  80lbs.  of  pale  barley  malt,  and 
40lb8.  of  pale  wheat  malt,  and  infuse  them  in  100  quarts  of  water  of  122°  Fahr.,  and 
afterwards  mash  them  properly  with  300  quarts  of  hotter  water.  The  wort  thus  made 
is  to  be  cooled,  drawn  off  from  the  grains,  fermented  with  yeast  for  3  days,  then  the 
beer  is  to  be  barrelled  up  for  use. 

I  have  already  adverted  to  the  quick  acetification  of  malt-wort  by  Mr.  Ham*s  pat4;nt 
process.  This  has  been  mounted  upon  a  large  scale  of  late  years,  the  air  for  oxygenating 
the  alcohol  of  the  wash,  previously  fermented  with  yeast,  having  been  supplied  from 
two  gasometers,  alternately  moved  by  steam-engine  power.  Two  circumstances  attend 
this  quick  process;  which  are,  that  as  the  materials  are  not  thoroughly  acetified,  the 
product  must  be  left  for  some  time  to  ripen  in  casks,  and  the  resulting  yin^ar  has  not 
the  flavor  of  that  slowly  made  in  the  old  way.  I  am  informed  that  a  vinegar,  equiva- 
lent not  merely  to  5i  per  cent  has  been  produced,  but  one  five  times  stronger,  bv 
operating  with  an  apparatus  13  feet  high,  14  wide  at  bottom,  and  15  at  top,  in  which 
an  adequate  temperature  was  generated  during  the  oxidation  of  the  great  mass  of 
materials,  without  artificial  warmth. 

8.  Chemical  process. — Acetic  acid  from  the  pure  acetate  of  soda  is  formed  as  follows : 
— 100 lbs.  of  the  pulverized  salt  being  put  into  a  hard  glazed  stoneware  receiver,  or 
deep  pan,  from  35  to  36  lbs.  of  concentrated  sulphuric  acid  are  poured  in  one  stream 
upon  the  powder,  so  as  to  flow  under  it  The  mixture  of  the  salt  and  acid  is  to  be 
made  very  slowly,  in  order  to  moderate  the  action  and  the  heat  generated  as  much  as 
possible.  After  the  materials  have  been  in  intimate  contact  for  a  few  hours,  the  de- 
composition is  effected ;  sulphate  of  soda  in  crystalline  gi-ains  will  occupy  the  bottom  of 
the  vessel,  and  radical  vinegar,  or  acetic  acid  (hydrate),  the  upper  portion,  partly  liquid 
and  partly  in  crystals.  A  small  portion  of  pure  acetate  of  lime,  added  to  the  acid,  will 
free  it  from  any  remainder  of  sulphate  of  soda,  leaving  only  a  little  acetate  in  its  place ; 
and  though  a  small  portion  of  sulphate  of  soda  may  still  remain,  it  is  unimportant 
whereas  the  presence  of  any  free  sulphuric  acid  would  be  very  injurious.  This  is  easily 
detected  by  evaporating  a  little  of  the  liquid,  at  a  moderate  heat  to  dryness,  when  that 
mineral  acid  can  be  distinguished  from  the  neutral  soda  sulphate.  This  plan  of  super- 
seding a  troublesome  distillation,  which  is  due  to  M.  Mollerat,  is  one  of  the  greatest 
improvements  in  this  process,  and  depends  upon  the  insolubility  of  the  sulphate  of  soda  in 
acetic  acid.  The  sulphate  of  soda  thus  recovered,  and  well  drained,  serves  anew  to 
decompose  acetate  of  lime ;  so  that  nothing  but  this  cheap  earth  is  consumed  in  carrying 
on  the  manufacture.  To  obtain  absolutely  pure  acetic  acid,  the  above  acid  has  to  be 
distilled  in  a  glass  retort.  That  acid,  in  its  crystallizable  state,  boils  at  230°  Fahr.,  or 
110°  C,  by  my  experiments  made  with  a  pure  acid  prepared  by  M.  Lemire,  of  Paris: 
others  have  rated  its  boiling  point  114°  and  even  120°  C. 

The  following  table  of  the  specific  gravities  of  acetic  acid,  of  successive  strengths,  is 
the  result  of  a  series  of  experiments  made  by  me  in  Glasgow  in  May,  1819;  the  liquid 
crystallizable  hydrate  being  reckoned  100 : — 


Acid. 

8p.  Gr. 

Acid. 

8p.  Gr. 

Acid. 

BpL  Gr. 

100 

1  -0620 

76 

1  -0743 

52 

1  -0617 

98 

1  -0650 

74 

1  -0740 

50 

1  -0603 

96 

1  -0680 

72 

1  -0733 

45 

1  -0658 

94 

1  -0700 

70 

1  -0725 

40 

1  -0512 

92 

1  0715 

68 

1  -0716 

35 

1  -0459 

90 

1  -0728 

66 

1-0712 

80 

1  -0406 

88 

1  -0730 

64 

1  -0701 

25 

1  -0342 

86 

1  -0735 

62 

1  -0687 

20 

1  -0282 

84 

1  -0738 

60 

1  -0676 

15 

1  -0213 

82 

1  -0740 

58 

1  -0665 

10 

1  -0147 

80 

1  -0750 

56 

1  -0647 

5 

1-0075 

78 

1  -0748 

54 

1  -0634 

I 


>■«    1 1 


1 


^  tl 


•  ACETIC  ACID. 

In  Berzdius  JahreH  herkhte  xvi.  192,  the  table  of  Van  der  Toom  is  ^iven  for  the 
successive  quantities  of  dry  acetic  acid,  corresponding  to  successive  densities.    lie  rates 
the  sp.  gr.  of  the  hydrate  at  10670,  being  tlie  acid  which  contains  85  11  of  dry  acid- 
In  my  table,  the  equivalent  hydrate  is  marked  J  062,  a  gravity  as  low  as  is  probably 
to  be  obtained  by  weighing  a  solution  of  the  drained  crystals.     An  acid  of  1-0698 
contains,  according  to  him,  61  of  the  dry;  while  an  acid  ot  10675  corresponds,  in  my 
table,  to  60  of  the  hydrate,  or  61  of  dry  acid.     In  general  his  gravities  are  a  little 
greater  than  mine  at  corresponding  degrees  of  acid  strength.     Tlie  above  numbers  in 
my  table  are  experimental,  not  interpolated  from  a  few  points,  and  may,  I  hope,  be 
relied  upon.   The  greatest  density  seems  to  be  produced  when  two  atoms  of  water  —  18 
are  mixed  with  one  of  the  hydrate  ==-  60,  or  23  with  77,  at  which  dilution  the  differences 
of  density  are  very  small,  and  minute  errors  may  have  occurred.     When  6  atoms  of 
water  are  added  to  one  of  the  hydrate,  making  7  atoms  of  water  in  all,  then  the  acid 
acquires  its  primitive  liquid  density  of  about  1062.     A  curious  analogy  exists  in  this 
respect  with  nitric  acid,  which  suffers  the  greatest  degree  of  condensation,  in  the  series 
of  its  dilutions,  when  one  atom  of  the  real  acid  is  combined  with  7  atoms  of  water. 
Pure  acetic  acid  possesses  a  peculiar  pungent,  though  not  disagreeable  smell,  and  a 
strongly  acid  taste.     It  crystallizes  in  needles  and  plates  when  cooled  to  65°  Fahr   and 
melts  when  heated  to  61*''.     The  specific  gravity  of  the  crystals  (taken  by  means  of 
spirits  of  turpentine)  I  found  to  be  M36  at  65°  Fahr.     The  vapor  of  the  boiling 
acid  IS  highly  combustible,  and  burns  with  a  blue  flame.     Acetic  acid  hydrate  dissolves 
camphor,  ghadine,  resins,  the  fibrine  of  blood,  and  several  organic  compounds.     When 
Its  vapor  is  conducted  through  a  slightly  ignited  porcelain  tube,  it  is  converted  entirely 
•into  carbonic  acid  and  aceton,  an  atom  of  the  acid  being  resolved  into  an  atom  of  each 
of   the  resultants.     At  a  white  heat^  the  vapor  is   converted   into  carbonic  acid, 
carburetted  hydrogen,  and  water.   The  acetates  comport  themselves  at  elevated  tempe- 
ratures differently,  according  to  the  strength  of  affinity  between  the  acid  and  the 
base.    When  this  is  weak  the  acid  escapes  unchanged,  and  the  stronger  it  is,  the  more 
acid  18  converted  into  aceton.     Acetate  of  barytes  affords  most  of  this  spirituous 
liquor,  and  next  to  it  the  alkaline  acetates  and  acetate  of  lead. 

Acetate  of  copper  yields,  at  a  heat  of  400°  or  600°,  a  concentrated  acetic  acid, 
mixed  with  some  aceton.  This  process  was  formerly  employed  for  preparing  radical 
vinegar,  as  also  that  of  decomposing  that  of  acetate  of  lead,  by  sulphuric  acid;  but 
both  are  now  renounced  for  the  process  by  acetate  of  soda  above  described. 

Acetic  acid  is  a  pretty  stable  compound,  as  is  evinced  by  its  compound  with  soda 
and  potash,  bearing  the  heat  of  600°  Fahr.  without  decomposition.  Acetate  of  potash 
and  soda,  dissolved  in  much  water,  readily  mould  and  decompose ;  but  acetate  of  am- 
monia is  not  liable  to  change  in  close  vessels.  When  acetic  acid  is  distilled  along  with 
peroxide  of  manganese  and  sulphuric  acid,  it  is  converted  into  formic  acid.  Iodic  acid 
has  the  same  effect  with  precipitation  of  iodine:  it  reduces  gold  from  its  chloride 
without  disengagement  of  carbonic  acid ;  but  it  does  not  reduce  mercury  from  its  ni- 
trate or  sulphate,  as  formic  acid  does. 

The  simplest  reagent  for  purifying  common  vinegar  is  recently  calcined  wood  char- 
coal in  fine  powder;  with  which  it  may  be  digested,  or,  what  is  better,  distilled,  where- 
by a  portion  of  the  water  comes  over  first,  and  may  be  got  rid  of,  while  the  stronger 
vinegar  is  a  later  product  Attempts  are  often  made  to  give  wood  vinegar  the  flavor  of 
that  made  from  wine,  by  adding  acetic  ether,  wine,  Ac,  but  never  with  complete  effect 
The  best  disguise  is  obtained  by  mixing  in  some  highly  flavored  Orleans  vinegar. 
Malt  vinegar  prepared  by  very  slow  fermentation  in  the  air,  acquires  a  peculiar  ethe- 
reous  odor,  which  cannot  be  imitated  artificially,  and  hence  persons  accustomed  to  the 
flavor  of  such  vinegar,  by  itself  or  in  pickles,  do  not  relish  the  vinegar  made  by  the 
quick  oxidizement  process,  either  from  malt  or  spirits.  Even  subjecting  this  vinegar 
to  the  action  of  rape  accomplishes  imperfectly  the  object  in  view. 

Were  vinegar  pure,  it  would  be  valued  by  its  specific  gravity  alone,  which  at  all 
strengths  under  50  per  cent  gives  exact  indications ;  but  this  is  seldom  the  case,  for 
ordinary  vinegar  contains  more  or  less  gluten  and  other  organic  matter,  such  as  caramel, 
or  burnt  sugar,  to  color  and  flavor  it  besides  sulphuric  and  possibly  other  acids. 
Hence  the  Excise  have  adopted  the  following  plan  of  acetometry  su^ested  by  Messrs. 
Taylor.  When  pure  vinegar  is  saturated  with  quicklime,  the  liquid  takes  a  density 
double  of  that  due  to  the  acetic  acid  present  Thus,  an  acetate  of  lime  of  sp.  gr.  1  -018, 
corresponds  to  a  pure  vinegar  of  1  -009 ;  but  malt  vinegar  of  that  strength  has  its  density 
raised  to  1*014  by  the  gluten.  When  such  vinegar  is  saturated  with  quicklime,  the 
acetate  acquires  a  specific  gravity  of  1-023,  from  which,  if  the  five  due  to  the  gluten 
be  deducted,  the  remainder,  1*018,  will  be  double  of  the  true  density.  Revenue  proof 
vinegar,  called  No.  24,  has,  according  to  these  gentlemen,  the 


ACETIC  ACID. 
Sp.  gr.  1-0085,  and  contains  of  real  acid   5  in  100. 


Da 

1-0170 

do. 

do. 

10 

do. 

Do. 

1-0257 

«  do. 

do. 

16 

do. 

Do. 

1-0320 

do. 

do. 

20 

do. 

Do. 

1-0470 

do. 

do. 

30 

do. 

Do. 

1-0680 

do. 

do. 

40 

do. 

The  acid  of  this  table  is  the  anhydrous,  being  stronger  by  about  15  per  cent  than 
that  of  my  table  given  above.  The  chemical  analysis  of  vineijar  consists  first  in  deter- 
mining the  presence  and  proportion  of  foreign  matter.  With  this  view  600  grains  of 
it  should  be  evaporated  by  the  heat  of  a  chlor-calcium  bath,  the  residuum  weiglied  and 
examined.  If  it  be  sour,  sulphuric  acid  may  be  suspected,  and  its  amount  be  ascer- 
tained by  precipitation  with  nitrate  of  barytes,  and  weighing  the  washed  and  dried  pre- 
cipitate. Every  118  parts  indicate  49  of  oil  of  vitrol ;  but  if  saline  sulphates  be  pre- 
sent their  amount  may  be  ascertained  by  igniting  the  above  residuum  and  weighing 
what  remains.  The  loss  in  ignition  will  be  due  to  organic  matter,  acetates,  and  sul- 
phuric acid.  If  an  alkaline  acetate  be  present  after  ignition,  the  residuum  may  be  an 
alkaline  carbonate.  Nitric  acid  is  best  detected  by  adding  a  few  drops  of  a  dilute  sul- 
phate of  indigo  to  the  vinegar,  and  by  boiling  the  mixture;  when  the  blue  will  pass  into 
a  dirty  brown  yellow  if  nitric  acid  be  present  In  common  cases  a  ready  mode  of  esti- 
mating the  strength  of  the  vinegar  is  wanted,  and  no  reagent  is  better  for  the  purpose 
than  tlie  bicarbonate  of  potash,  two  grains  of  which  are  equivalent  to  very  nearly  one  of 
anhydrous  acetic  acid.  To  100  or  lOOO  grs.  of  the  vinegar  in  question  we  have  only  to 
add  from  a  weighed  parcel  of  pounded  bicarbonate  of  potash,  enough  to  produce  neu- 
tralization by  the  test  of  litmus  paper,  and  the  half  number  of  grains  required  denotes  the 
number  of  grains  of  acetic  acid  in  100  or  1000  of  the  vinegar.  Or  a  normal  solution  of 
the  bicarbonate  may  be  kept  ready  made,  of  which  1000  water  grain  measures  contain 
100  of  the  salt;  then  each  20  grain  measures  expended  in  neutralizing  1000  water  grain 
measures  of  the  vinegar  denote  one  grain  of  real  acetic  acid.  As  the  extrication  of  car 
bonic  acid  from  the  bicarbonate  is  apt  however,  in  common  hands  to  cause  fallacies, 
I  prefer  ammonia  as  a  general  acidimetrical  test  of  which  1000  water  grain  measures 
of  specific  gravity  0*992  neutralize  exactly  one  atom  of  acetic  acid;  that  is,  51  grains  of 
the  anhydrous,  or  60  of  the  hydrate ;  therefore  after  adding  that  test  ammonia  to  the 
vinegar  faintly  reddened  with  litmus,  out  of  a  graduated  glass  tube,  till  the  neutral  tint 
of  color  be  hit  the  number  of  water  grain  measures  of  test  expended,  being  multiplied 
either  by  61  or  60,  will  give  for  a  product  the  per  centage  of  anhydrous  or  hydrated 
acetic  acid.  This  is  the  method  I  have  pursued  for  very  many  years,  and  which  gives 
results  of  perfect  precision  in  a  few  minutes. 

Vinegar  is  so  extensively  employed  as  a  condiment,  that  it  should  be  of  better  quality 
than  is  commonly  on  sale  in  the  United  Kingdom,  where  it  is  almost  always  conta- 
minated with  oil  of  vitriol.  All  our  pickles  participate  in  the  same  noxious  ingre- 
dient The  fumes  of  vinegar,  and  even  its  odor,  as  in  the  vinegar  of  the  Three 
Thieves  of  Marseilles,  were  long  supposed  to  be  counteractive  of  contagion  in  sick 
rooms;  but  they  are  rather  injurious,  by  covering  unwholesome  smells  from  want  of 
due  cleanliness  and  ventilation,  and  should  never  be  relied  upon.  In  combination  with 
alumina,  and  also  with  oxide  of  iron,  it  is  extensively  used  in  the  dyeing  and  printing 
of  cotton,  under  the  names  of  red  liquor  and  iron  liquor,  as  mordants  for  bright  and 
dark  colors. 

According  to  Dobereiner  and  Liebig,  in  the  conversion  of  alcohol  into  acetic  acid  no 
carbonic  acid  is  formed.  100  lbs.  of  alcohol  consisting  of  52*6  carbon  -|- 12*9  hydrogen 
-f  34-5  oxygen,  absorb  from  the  air,  in  the  process  of  acetification,  35*2  lbs.  of  oxygen, 
which  abstract  4*4  lbs.  of  hydrogen  from  the  alcohol,  and  thus  generate  39*6  iW  of 
water,  leaving  the  substance  called  aldehyde  (dehydrogenated  alcohol),  which  consists 
of  52*6  carbon  -f  8*6  hydrogen  -f  68*4  oxygen. 

In  practice  we  cannot  obtain  so  much  acid  as  the  above,  but  the  theoretical  maximum 
serves  as  a  beacon,  and  the  nearer  we  can  approach  to  it  the  better.  About  3600 
cubic  feet  of  air  contain  69  lbs.  of  oxygen,  the  quantity  barely  necessary  for  acetifying 
100  lbs.  of  alcohol;  but  as  the  air  is  only  partially  stripped  of  that  element,  much 
more  is  needed,  and  this  excessive  current  carries  off  some  alcohol,  aldehyde,  and  acetic 
acid,  and  so  lessens  the  product  I^  on  the  other  hand,  air  be  too  sparingly  supplied, 
volatile  aldehyde  is  chiefly  formed,  which  flies  oflF,  and  leaves  a  mawkish  putrefying 
liquor  of  no  value. 

We  may  complete  the  preceding  view  of  the  production  of  acetic  acid,  by  showing 
the  relations  which  subsist  between  it  and  sugar,  and  starch,  through  the  medium  of 
alcohol— four  correlative  compounds,  100  lbs.  of  cane  sugar  are  convertible  into  100  lbs. 
of  starch  sugar  or  grape  sugai*,  by  boiling  it  with  sulphuric  or  tartaric  acid,  and  abstract- 
ing the  acid  by  means  of  chalk;  and  that  weight  of  either  kind  of  sugar  is  capable  of 


» 


• 


ACETIC  ACID. 


yielding  by  fermentation,  53-7  lbs.  of  alcohol.  100  lbs.  of  starch,  if  well  saccharified, 
should  afford  fully  100  lbs.  of  starch  sugar,  and,  therefore,  63-7  lbs.  alcohol.  Theue 
we  the  theoretical  quantities,  but  they  can  nev^r  be  realized  in  practice. 

A  quarter  of  good  malt,  weighing  320  lbs.,  contains  by  my  experimenta  144  solid 
estract,  which  should  yield,  firs^  69i  alcohol ;  and  next  100  lbs.  of  acetic  acid  hydrate, 
equivalent  to  17  times  that  weight  of  revenue  proof  vinegar -=»  170  gallons  nearly. 

Before  the  process  for  pyroligneous  acid,  or  wood  vinegar,  was  known,  there  was  only 
one  method  of  obtaining  strong  vinegar  practised  by  chemists ;  and  it  is  still  followed  by 
some  operators,  to  prepare  what  is  called  radical  or  aromatic  vinegar.  This  consists  in 
decomposing,  by  heat  alone,  the  crystallized  binacetate  of  copper,  commonly,  but  impro- 
perly, called  distilled  verdigris.     With  this  view,  we  take  a  stoneware  retort  {fig.  1), 

of  .1  size  suited  to  the 
quantity  we  wish  to  oper- 
ate upon ;  and  coat  it  with 
a  mixture  of  fire  clay  and 
horsedung,  to  make  it 
stand  the  heat  better. 
When  this  coating  is  dry, 
we  introduce  into  the  re- 
tort the  crystallized  ace- 
tate slightly  bruised,  but 
jTiV  1,  very  dry;  we  fill  it  as  far 

as  it  will  hold  without 
spflhng  when  the  beak  is  considerably  inclined.  We  then  set  it  in  a  proper  furnace. 
We  attach  to  its  neck  an  adopter  pipe,  and  two  or  three  globes  with  opposite  tubu- 
wres,  and  a  last  globe  with  a  vertical  tubulure.  The  apparatus  is  terminated  by  a 
Welter's  tube,  with  a  double  branch ;  the  shorter  issues  from  the  last  ?lobe,  and  the 
other  dips  into  a  flask  filled  with  distilled  vinegar.  Everything  being  thus  arranged, 
we  lute  the  joinings  with  a  putty  made  of  pipeclay  and  linseed  oil,  and  cover  them  with 
glue  paper.  Each  globe  is  placed  in  a  separate  basin  of  cold  water,  or  the  whole  may 
Be  put  into  an  oblong  trough,  through  which  a  constant  stream  of  cold  water  is  made  to 
flow.  The  tubes  must  be  allowed  a  day  to  dry.  Next  dav  we  proceed  to  the  distilla- 
tion, tempering  the  heat  very  nicely  at  the  beginning,  and  increasing  it  by  very  slow 
degrees  till  we  see  the  drops  follow  each  other  pretty  rapidly  from  the  neck  of  the  retort, 
or  the  end  of  the  adopter  tube.  The  vapors  which  pass  over  are  very  hot,  whence  a  se- 
ries of  globes  are  necessary  to  condense  them.  We  should  renew,  from  time  to  time,  the 
water  of  the  basins,  and  keep  moist  pieces  of  cloth  upon  the  globes;  but  this  demands 
great  care,  especially  if  the  fire  be  a  little  too  brisk,  for  the  vessels  become,  in  that  case, 
BO  hot,  that  they  would  infallibly  be  broken,  if  touched  suddenly  with  cold  water.  It  is 
always  easy  for  us  to  regulate  this  operation,  according  to  the  emission  of  gas  from  the 
extremity  of  the  apparatus.  When  the  air  bubbles  succeed  each  other  with  great  ra- 
pidity,  we  must  damp  the  fire. 

The  liquor  which  passes  in  the  first  half  hour  is  weakest;  it  proceeds,  in  some  mea- 
sure, from  a  little  water  sometimes  left  in  the  crystals,  which  when  well  made,  however, 
ought  to  be  anhydrous.  A  period  arrives  towards  the  middle  of  the  process  when  we 
see  the  extremity  of  the  beak  of  the  retort,  and  of  the  adopter,  covered  with  crystals  of  a 
lamellar  or  needle  shape,  and  of  a  pale  green  tint.  By  degrees  these  crystals  are  carri- 
ed into  the  condensed  liquid  by  the  acid  vapors,  and  give  a  color  to  the  product.  These 
cr)  stals  are  merely  some  of  the  cupreous  salt  forced  over  by  the  heat.  As  the  process 
approaches  its  conclusion,  we  find  more  difliculty  in  raising  the  vapors;  and  we  must 
then  augment  the  intensity  of  the  heat,  in  order  to  continue  their  disengagement.  Finally, 
we  judge  that  the  process  is  altogether  finished,  when  the  globes  become  cold,  notwith- 
standing the  furnace  is  at  the  hottest,  and  when  no  more  vapors  are  evolved.  The  fire 
may  then  be  allowed  to  go  out,  and  the  retort  to  cool. 

As  the  acid  thus  obtained  is  slightly  tinged  with  copper,  it  must  be  rectified  before 
bringin?  it  into  the  market.  For  this  purpose  we  may  make  use  of  the  same  apparatus, 
only  substituting  for  the  stoneware  retort  a  glass  one,  placed  in  a  sand  bath.  All  the 
globes  ought  to  be  perfectly  clean  and  dry.  The  distillation  is  to  be  conducted  in  the 
usual  way.  If  we  divide  the  product  into  thirds,  the  first  yields  the  feeblest  acid,  and 
the  third  the  strongest.  We  should  not  push  the  process  quite  to  dryness,  because 
there  remain  in  the  last  portions  certain  impurities,  which  would  injure  the  flavor  of 
the  acid. 

The  total  acid  thus  obtained  forms  nearly  one  half  of  the  weight  of  the  acetate 
employed,  and  the  residuum  forms  three  tenths ;  so  that  about  two  tenths  of  the  acid 
kave  been  decomposed  by  the  heat,  and  are  lost.  As  the  oxyde  of  copper  is  readily 
reduced  to  the  metallic  state,  its  oxygen  goes  to  the  elements  of  one  part  of  the  acid,  and 
fbnns  water,  which  mingles  with  the  products  of  carbonic  acid,  carbureted  hydrogen,  and 


ACETIC  ACID.  9 

carboEic  oxyde  gases  which  are  disengaged  :  and  there  remains  in  the  retort  some  chai- 
coal  mixed  with  metallic  copper.  These  two  combustibles  are  in  such  a  state  of  division, 
that  the  residuum  is  pyrophoric.  Hence  it  often  takes  fire  the  moment  of  its  being  re- 
moved»from  the  cold  retort.  The  very  considerable  loss  experienced  in  this  operation 
has  induced  chemists  to  try  diflerent  methods  to  obtain  all  the  acid  contained  in  the  ace- 
tate. Thus,  for  example,  a  certain  addition  of  sulphuric  acid  has  been  prescribed  ;  but, 
besides  that  the  radical  vinegar  obtained  in  this  way  always  contains  sulphurous  acid, 
from  which  it  is  difficult  to  free  it,  it  is  thereby  deprived  of  that  spirit  called  the  jryro- 
aceticy  which  tempers  the  sharpness  of  its  smell,  and  gives  an  agreeable  aroma.  It  is  to 
be  presumed,  therefore,  that  the  preceding  process  will  continue  to  be  preferred  for  mak- 
ing aromatic  vinegar.  Its  odor  is  often  further  modified  by  essential  oils,  such  as  those 
of  rosemary,  lavender,  &c. 

4.  Pyroligneous  ^cid,  or  Wood  Vinegar.— The  process  for  making  this  acid  is  founded 
upon  the  general  property  of  heat,  to  separate  the  elements  of  vegetable  substances,  and 
to  unite  them  anew  in  another  order,  with  the  production  of  compounds  which  did  not 
exist  in  the  bodies  subjected  to  its  action.  The  respective  proportion  of  these  products 
vaiies,  not  only  in  the  diflerent  substances,  but  also  in  the  same  substance,  according  as 
the  degree  of  heat  has  been  greater  or  less,  or  conducted  with  more  or  Jess  skill.  When 
we  distil  a  vegetable  body  in  a  close  vessel,  we  obtain  at  first  the  included  water,  or  tnat 
of  vegetation  ;  there  is  next  formed  another  portion  of  water,  at  the  expense  of  the  oxy- 
gen and  hydrogen  of  the  body ;  a  proportional  quantity  of  charcoal  is  set  free,  and,  with 
the  successive  increase  of  the  heat,  a  small  portion  of  charcoal  combines  with  the  oxygen 
and  hydrogen  to  form  acetic  acid.  This  was  considered,  for  some  time,  as  a  peculiar  acid, 
and  was  accoidingly  called  pyroligr.eous  acid.  As  the  proportion  of  carbon  becomes 
preponderant,  it  combines  with  the  other  principles,  and  then  some  empyreumalic  oil  is 
volatilized,  of  little  color,  but  which  becomes  thicker,  and  of  a  darker  tint,  always  getting 
more  loaded  with  carbon. 

Several  elastic  fluids  accompany  these  diflTerent  products.  Carbonic  acid  comes  over, 
but  m  small  quantity,  much  carburreted  hydrogen,  and,  towards  the  end,  a  considerable 
proportion  of  carbonic  oxyde.  The  remainder  of  the  charcoal,  which  could  not  be  carried 
ofl'in  these  several  combinations,  is  found  in  the  retort,  and  preserves,  usually,  the  form 
of  the  vegettible  body  which  furnished  it.  Since  mankind  havo^  begun  to  reason  on  the 
diflerent  operations  of  the  arts,  and  to  raise  them  to  a  level  with  scientific  researches, 
they  have  introduced  into  several  branches  of  manufacture  a  muliitude  of  improvements, 
of  which,  formerly,  they  would  hardly  have  deemed  them  susceptible.  Thus,  in  pa/tir  a- 
lar,  the  process  for  carbonizing  wood  has  been  singularly  meliorated,  and  in  reference  to 
the  preceding  observations,  advantage  has  been  derived  from  several  products  that  for- 
merly were  not  even  collected. 

The  apparatus  employed  for  obtaining  crude  vinegar  from  wood,  by  theagency  of  heat, 

are  large  iron  cylinders.     In  this  country  they  are  made 
pEZ^T-rpZL,  of  cast  iron,  and  are  laid  horizontally  in  the  furnace ;  in 

TXlAM.tZ?  France,  they  are  made  of  sheet  iron  riveted  together,  and 

they  are  set  upright  in  the  fire.  Fig.  2  will  give  an  ac- 
curate idea  of  the  British  plan,  which  is  much  the  same  as 
that  adopted  for  decomposing  pit  coal  in  gas  works,  only 
that  the  cylinders  for  the  pyroligneous  acid  manufacture  are 
generally  larger,  being  frequently  4  feet  in  diameter,  and 
6  or  8  feet  long,  and  built  horizontally  in  brickwork,  so 
that  the  flame  of  one  furnace  may  play  around  two  ot 
them.  It  would  probably  answer  better,  if  their  size  were 
brought  nearer  the  dimensions  of  the  gas-light  retorts,  and 
if  the  whole  system  of  working  them  were  assimilated  to 
that  of  coal  gas. 

The  foiiowmg  arrangement  is  adopted  in  an  excellent  esta- 
blishment in  Glasgow,  where  the  above  large  cylinders  are 

6  feet  long,  and  both  ends  of  them  project  a  very  little  bevond 

the  brickwork.  One  end  has  a  disc  or  round  plate  of  cast  iron,  well  fitted,  and  firmly  boiled 
to  It,  from  the  centre  of  which  disc  an  iron  tube,  about  6  inches  diameter,  proceeds  and 
enters,  at  a  right  angle,  the  main  tube  of  refrigeration.  The  diameter  of  this  tube  may  be 
•  °^ii  i"  ^^  inches,  according  to  the  number  of  cylinders.  The  other  end  of  the  cylinder 
is  called  the  mouth  of  the  retort ;  this  is  closed  by  a  disc  of  iron,  smeared  round  its  edge 
by  clay  lute,  and  secured  in  its  place  by  fir  wedees.  The  charge  of  wood  for  such  a  cylin- 
der IS  about  8  cwt.  The  hard  woods— oak,  ash,  birch,  and  beech— are  alone  used ;  fir  does 
not  answer.  The  heat  is  kept  up  during  the  day-time,  and  the  furnace  is  allowed  to  cool 
during  the  night.  Next  morning  the  door  is  opened,  the  charcoal  removed,  and  a  new 
cliarge  of  wood  is  introduced.  The  average  product  of  crude  vinegar  called  pvrolis- 
ncous  a^id,  is  35  gallons.     It  is  much  contaminated  with  tar,  is  of  a  deep  brown' color. 


10 


ACETIC  ACID. 


and  has  a  sp.  gr.  of  1'025.  Its  total  weight  is  therefore  about  300  lbs.,  but  the  residuarr 
charcoal  is  found  to  weigh  no  more  than  one  fifth  of  the  wood  employed ;  hence  nearly 
one  half  of  the  ponderable  matter  of  the  wood  is  dissipated  in  incondensable  gases. 
Count  Rumford  states,  that  the  charcoal  is  equal  in  weight  to  more  than  four  tehths  of 
the  wood  from  which  it  is  made.  The  count's  error  seems  to  have  arisen  from  the  slight 
heal  of  an  oven  to  which  his  wood  was  exposed  in  a  glass  cylinder.  The  result  now 
given,  is  the  experience  of  an  eminent  manufacturing  chemist. 

The  crude  pyroligneous  acid  is  rectified  by  a  second  distillation  in  a  copper  still,  in  the 
body  of  which  about  twenty  gallons  of  viscid  tarry  matter  are  left  from  every  100.  It  has 
now  become  a  transparent  brown  vinegar,  having  a  considerably  empyreumatic  smell, 
and  a  sp.  gr.  of  1-013.  Its  acid  powers  are  superior  to  those  of  the  best  household 
vinegar,  in  the  proportion  of  three  to  two.  By  redistillation,  saturation  with  quick- 
lime, evaporation  of  the  liquid  acetate  to  dryness,  and  conversion  into  acetate  of  soda  by 
sulphate  of  soda,  the  empyreumatic  matter  is  so  completely  dissipated,  that  on  decom- 
posing the  pure  acetate  of  soda  by  sulphuric  acid,  a  perfectly  colorless  and  grateful  vine- 
gar rises  in  distillation.  Its  strength  will  be  proportionable  to  the  concentration  of  the 
decomposing  acid. 

The  acetic  acid  of  the  chemist  may  be  prepared  also  in  the  following  modes: — 1.  Two 
parts  of  fused  acetate  of  potash,  with  one  of  the  strongest  oil  of  vitriol,  yield,  by  slow 
distillation  from  a  glass  retort  into  a  refrigerated  receiver,  concentrated  acetic  acid.  A 
small  portion  of  sulphurous  acid,  which  contaminates  it«  may  be  removed  by  redistillation 
from  a  little  acetate  of  lead.  2.  Or  four  parts  of  good  sugar  of  lead,  with  one  part  of 
sulphuric  acid,  treated  in  the  same  way,  afford  a  slightly  weaker  acetic  acid.  3.  Gently 
calcined  sulphate  of  iron,  or  green  vitriol,  mixed  with  sugar  of  lead,  in  the  prep  ortion  ol 
1  of  the  former  to  2^  of  the  latter,  or  with  acetate  of  copper,  and  carefully  distilled  from 
a  porcelain  retort  into  a  cool  receiver,  may  be  also  considered  an  economical  process. 
But  that  with  binacetate  of  copper  above  described,  is  preferable  to  any  of  these. 

The  maniifacture  of  pyroligneous  acid  is  conducted  in 
the  following  way  in  France.  Into  large  cylindrical 
vessels  {fig.  3)  made  of  riveted  sheet  iron,  and  having 
at  their  top  and  side  a  small  sheet  iron  cylinder,  the  wood 
intended  for  making  charcoal  is  introduced.  To  the 
upper  part  of  this  vessel  a  cover  of  sheet  iron,  b,  is 
adapted,  which  is  fixed  with  bolts.  This  vessel,  thus 
closed,  represents,  as  we  see,  a  vast  retort.  When  it  is 
prepared,  as  we  have  said,  it  is  lifted  by  means  of  a  swing 
crane,  c,  and  placed  in  a  furnace,  d  (Jig.  4),  of  a 
form  relative  to  that  of  the  vessel,  and  the  opening  of  the 
furnace  is  covered  with  a  dome,  e,  made  of  masonry  or 
brickwork.  The  whole  being  thus  arranged,  heat  is  ap- 
plied in  the  furnace  at  the  bottom.  The  moisture  of 
the  wood  is  first  dissipated,  but  by  degrees  the  liquor 
ceases  to  be  transparent,  and  becomes  sooty.  An  adopter 
tube.  A,  is  then  fitted  to  the  lateral  cylinder.  This  adopter 

0/<— ^"a^^^sP^  Tf^a^  enters  into  another  tube  at  the  same  degree  of  inclination 
OTT]''  1  J^^  which  commences  the  condensing  apparatus.  The  means 
^—T  U  U  r*l     of  condensation  vary  according  to  the  localities.     In  cer- 

tain works  I  hey  cool  by  means  of  air,  by  making  the 
vapor  pass  through  a  long  series  of  cylinders,  or  some- 
times, even,  through  a  series  of  casks  connected  together ; 
but  most  usually  water  is  used  for  condensing,  when  it 
can  be  easily  procured  in  abundance.     The  most  simple 

apparatus  employed  for  this 
purpose  consists  of  two  cy 
linders,  r,  f  {fig.  4),  tho 
one  within  the  other,  and 
which  leave  between  them 
a  suflUcient  space  to  allow 
a  considerable  body  of 
water  to  circulate  along  and 
cool  the  vapors.  This 
double  cylinder  is  adapted 
to  the  distilling  vessel,  and 
placed  at  a  certain  inclina- 
tion. To  the  first  double 
tube,  F,  F,  a  second,  and 


ACETIC  ACID. 


U 


Jt 


i. 


I 


«ometimes  a  third,  entirely  similar,  are  connected,  which,  to  save  space,  return  upon  them- 
fjelves  in  a  zigzag  fashion.  The  water  is  set  in  circulation  by  an  ingenious  means 
now  adopted  in  many  different  manufactories.  From  the  lower  extremity,  g,  of  the 
system  of  condensers,  a  perpendicular  tube  rises,  whose  lens^lh  should  be  a  little  more 
than  the  most  elevated  point  of  the  system.  The  water,  furnished  by  a  reservoir,  l, 
enters  by  means  of  the  perpendicular  tube  through  the  lower  part  of  the  system,  and 
fills  the  whole  space  between  the  double  cylinders.  When  the  apparatus  is  in  action, 
the  vapors,  as  they  condense,  ra.se  the  temperature  of  the  water,  which,  by  the  column 
in  L  G,  is  pressed  to  the  upper  part  of  the  cylinders,  and  runs  over  by  ihe  spout  k.  To 
this  point  a  very  short  tube  is  attached,  which  is  bent  towards  the  ground,  and  serves  as 
an  overflow. 

The  condensing  apparatus  is  tenninated  by  a  conduit  in  bricks  covered  and  sunk  in 
the  ground.  At  the  extremity  of  this  species  of  gutter  is  a  bent  tube,  e,  which  dis- 
charges the  liquid  product  into  the  first  cistern.  When  it  is*  full,  it  empties  itself,  by 
means  of  an  overflow  pipe,  into  a  great  reservoir :  the  tube  which  terminates  the  gutter 
plunges  into  «he  liquid,  and  thus  intercepts  communication  with  the  inside  of  the  appa- 
ratus. The  Qisengaged  gas  is  brought  back  by  means  of  pipes  m  l,  from  one  of  the  sides 
of  the  conduit  to  the  under  part  of  the  ash  pit  of  the  furnace.  Tbese  pipes  are  furnish- 
ed with  stopcocks  m,  at  some  distance  in  front  of  the  furnace,  for  the  purpose  of  regula- 
ting the  jet  of  the  gas,  and  interrupting,  at  pleasure,  communication  with  the  inside  of 
the  apparatus.  The  part  of  the  pipes  which  terminates  in  the  furnace  rises  perpendicu- 
larly several  inches  above  the  ground,  and  is  expanded  like  the  rose  of  a  watering  can,  n. 
The  gas,  by  means  of  this  disposition,  can  distribute  itself  uniformly  under  the  vessel,  with- 
out suffering  the  pipe  which  conducts  it  to  be  obstructed  by  the  fuel  or  the  ashes. 

The  temperature  necessary  to  effect  the  carbonization  is  not  considerable:  however,  at 
the  last  it  is  raised  so  high  as  to  make  the  vessels  red  hot ;  and  the  duration  of  the  process 
is  necessarily  proportional  to  the  quantity  of  wood  carbonized.  For  a  vessel  which  shall 
contain  about  5  meters  cube  (nearly  6  cubic  yds.),  8  hours  of  fire  is  sufficient.  It  is 
known  that  the  carbonization  is  complete  by  the  color  of  the  flame  of  the  gas :  it  is 
first  of  a  yellowish  red ;  it  becomes  afterwards  blue,  when  more  carbonic  oxyde  than 
carbonic  hydrogen  is  evolved ;  and  towards  the  end  it  becomes  entirely  white, —  a  circum- 
stance owing,  probably,  to  the  furnace  being  more  heated  at  this  period,  and  the 
combustion  being  more  complete.  There  is  still  another  means  of  knowing  the  state  of 
the  process,  to  which  recourse  is  more  frequently  had ;  that  is  the  cooling  of  the  first 
tubes,  which  are  not  surrounded  with  water  :  a  few  drops  of  this  fluid  are  thrown  upon 
their  surface,  and  if  they  evaporate  quietly,  it  is  judged  that  the  calcination  is  sufficient. 
The  adopter  tube  is  then  unluted,  and  is  slid  into  its  junction  pipe;  the  orifices  arc 
immediately  stopped  with  plates  of  iron  and  plaster  loam.  The  brick  cover,  e,  o^  the 
furnace  is  first  removed  by  means  of  the  swing  crane,  then  the  cylinder  itself  is  lifted 
out  and  replaced  immediately  by  another  one  previously  charged.  When  the  cylinder 
which  has  been  taken  out  of  the  furnace  is  entirely  cooled,  its  cover  is  removed,  and  the 
charcoal  is  emptied.  Five  cubic  meters  of  wood  furnish  about  7  chaldrons  (voies)  and 
a  half  of  charcoal.  (For  modifications  of  the  wood-vinegar  apparatus,  see  CharcoaIi 
and  Pyroligneous  Acip.) 

The  different  qualities  of  wood  employed  in  this  operation  give  nearly  similar  pro- 
ducts in  reference  to  the  acid ;  but  this  is  not  the  case  with  the  charcoal,  for  it  is  better 
the  harder  the  wood  ;  and  it  has  been  remarked  that  wood  long  exposed  to  the  air  fur- 
nishes a  charcoal  of  a  worse  quality  than  wood  carbonized  soon  after  it  is  cut. 

Having  described  the  kind  of  apparatus  employed  to  obtain  pyroligneous  acid,  I  shall 
now  detail  the  best  mode  of  purifying  it.  This  acid  has  a  reddish  brown  color ;  it  holds 
in  solution  a  portion  of  empyreumatic  oil  and  of  the  tar  which  were  formed  at  the  same 
time,  another  portion  of  these  products  is  in  the  state  of  a  simple  mixture  :  the  latter 
may  be  separated  by  repose  alone.  It  is  stated  above,  that  the  distilling  apparatus 
terminates  in  a  subterranean  reservoir,  where  the  products  of  all  the  vessels  are  mixed". 
A  common  pump  communicates  with  the  reservoir,  and  sinks  to  its  very  bottom,  in  order- 
that  it  may  draw  off  only  the  stratum  of  tar,  which,  according  to  its  greater  density, 
occupies  the  lower  part.  From  time  to  time  the  pump  is  worked  to  remove  the  tar  as  it 
is  deposited.  The  reservoir  has  at  its  top  an  overflow  pipe,  which  discharge^  the  clear* 
est  acid  into  a  cistern,  I'rom  which  it  is  taken  by  means  of  a  second  pump. 

The  pyroligneous  acid  thus  separated  from  the  undissolved  tar  is  transferred  from  this 
cistern  into  large  sheet  iron  boilers,  where  its  saturation  is  effected  eiiher  by  quicklime 
or  ])y  chalk,  the  latter  of  which  is  preferable,  as  the  lime  is  apt  to  take  some  of  the  iai 
into  combination.  The  acid  parts  by  saturation  with  a  new  portion  of  the  tar,  which  is 
removed  by  skimmers.  The  neutral  solution  is  then  allo\«ed  to  rest  for  a  sufficient  time 
to  let  its  clear  parts  be  drawn  off  by  decantation. 

The  acetate  of  lime  thus  obtained  indicates  by  the  hydrometer,  before  being  mixed  with 
the  waters  of  edulcoration,  a  degree  corresponding  to  the  acidimetric  degree  of  the  acid 


IS 


ACETIC  ACID. 


employed.  This  solution  must  be  evaporated  till  it  reaches  a  specific  gravity  of  I-IM 
(15°  Baume),  after  which  there  is  added  to  it  a  saturated  sohition  of  sulphate  of  soda. 
The  acids  exchange  bases ;  sulphate  of  lime  precipitates,  and  acetate  of  soda  remains  in 
solution.  In  some  manufactures,  instead  of  pursuing  the  above  plan,  the  sulphate  o/ 
soda  is  dissolved  in  the  hot  pyroligneous  acid,  which  is  afterwards  saturated  with  chalk 
or  lime.  By  this  means  no  water  need  be  employed  to  dissolve  the  sulphate,  and  ac- 
cordingly the  liquor  is  obtained  in  a  concentrated  form  without  evaporation.  In  both 
modes  the  sulphate  of  lime  is  allowed  to  settle,  and  the  solution  of  acetate  of  soda  is  de- 
canted. The  residuum  is  set  aside  to  be  edulcorated,  and  the  last  waters  are  employed 
for  washing  fresh  portions. 

The  acetate  of  soda  which  results  from  this  double  decomposition  is  afterwards  evap- 
orated till  it  attains  to  the  density  of  1*225  or  1-23,  according  to  the  season.  This  so- 
lution is  poured  into  large  crystallizing  vessels,  from  which,  at  the  end  of  3  or  4  days, 
according  to  their  capacity,  the  mother  waters  are  decanted,  and  a  first  crjstallizatioQ  is 
obtained  of  rhomboidal  prisms,  which  are  highly  colored  and  very  bulky.  Their  facettes 
are  finely  polished,  and  their  edges  very  sharp.  The  mother  waters  are  submitted  to 
successive  evaporations  and  crystallizations  till  they  refuse  to  crjstallize,  and  they  are 
then  burnt  to  convert  them  into  carbonate  of  soda. 

To  avoid  guesswork  proportions,  which  are  always  injurious,  by  the  loss  of  time  which 
they  occasion,  and  by  the  bad  results  to  which  they  often  lead,  we  should  determine 
experimentally,  beforehand,  the  quantities  absolutely  necessary  for  the  reciprocal  dccom- 
IKJsition,  especially  when  we  change  the  acid  or  the  sulphate.  But  it  may  be  remarked 
that,  notwithstanding  all  the  precautions  we  can  take,  there  is  always  a  notable  quantity 
of  sulphate  of  soda  and  acetic  acid,  which  disappear  totally  in  this  decomposition.  This 
arises  from  the  circumstance  that  sulphate  of  soda  and  acetate  of  lime  do  not  completely 
decompose  each  other,  as  I  have  ascertained  by  experiments  on  a  very  considerable  scale ; 
and  thus  a  portion  of  each  of  them  is  always  lost  with  the  mother  waters.  It  night  be 
supposed  that  by  calcining  the  acetate  of  lime  we  could  completely  destroy  its  empy. 
reumatic  oil ;  but,  though  I  have  made  many  experiments  with  this  view,  I  never  could 
abtain  an  acetate  capable  of  affording  a  tolerable  acid.  Some  manufacturers  prefer  to 
make  the  acetate  of  soda  by  direct  saturation  of  the  acid  with  the  alkali,  and  think  that 
the  higher  price  of  this  substance  is  compensated  by  the  economy  of  time  and  fuel  which 
it  produces. 

The  acetate  of  soda  is  easily  purified  by  crystallizations  and  lorrefaction ;  the  latter 
process,  when  well  conducted,  freeing  it  completely  from  every  particle  of  tar.  This 
torrefaction,  to  which  the  name  of  fusion  may  be  given,  requires  great  care  and  dexterity. 
It  is  usually  done  in  shallow  cast  iron  boilers  of  a  hemispherical  shape.  During  all  the 
time  that  the  heat  of  about  500°  Fahr.  is  applied,  the  fused  mass  must  be  diligently  work- 
ed with  rakes;  an  operation  which  continues  about  24  hours  for  half  a  ton  of  materials. 
We  must  carefully  avoid  raising  the  temperature  so  high  as  to  decompose  the  acetate^ 
and  be  sure  that  the  heat  is  equally  distributed ;  for  if  any  point  of  the  mass  enters  into 
decomposition,  it  is  propagated  with  such  rapidity,  as  to  be  excessively  difficult  to  stop 
its  progress  in  destroying  the  whole.  The  heat  should  never  be  so  great  as  to  disengage 
any  smoke,  even  when  the  whole  acetate  is  liquefied.  When  there  is  no  more  frothing 
up,  and  the  mass  flows  like  oil,  the  operation  is  finished.  It  is  now  allowed  to  cool  in  a 
body,  or  it  may  be  ladled  out  into  moulds,  which  is  preferable. 

When  the  acetate  is  dissolved  in  water,  the  charcoaly  matter  proceeding 
decomposition  of  the  tar  must  be  separated  by  filtration,  or  by  boiling  up  the 
the  specific  gravity  1*114,  when  the  carbonaceous  matter  falls  to  the  bottom, 
porating  the  clear  liquor,  we  obtain  an  acetate  perfectly  fine,  which  yields 
crystals  on  cooling.  In  this  state  of  purity  it  is  decomposed  by  sulphuric  acid,  in  order 
to  separate  its  acetic  acid. 

This  last  operation,  however  simple  it  appears,  requires  no  little  care  and  skill.  The 
acetate  of  soda  crystallized  and  ground  is  put  into  a  copper,  and  the  necessary  quantity 
of  sulphuric  acid  of  1*842  (about  35  per  cent,  of  the  salt)  to  decompose  almost,  but  not 
all,  the  acetate,  is  poured  on.  The  materials  are  left  to  act  on  each  other ;  by  degrees 
the  acetic  acid  quits  its  combination,  and  swims  upon  the  surface ;  the  greater  part  of 
the  resulting  sulphate  of  soda  falls  in  a  pulverulent  form,  or  in  small  granular  crystals, 
to  the  bottom.  Another  portion  remains  dissolved  in  the  liquid,  which  has  a  specific 
gravity  of  1-08.  By  distillation  we  separate  this  remainder  of  the  sulphate,  and  finall> 
obtain  acetic  acid,  having  a  specific  gravity  of  1*05,  an  agreeable  taste  and  smell,  though 
towards  the  end  it  becomes  a  little  empyreumatic,  and  colored;  for  which  reason, 
the  last  portions  must  be  kept  apart.  The  acid  destined  for  table  use  ought  to  be 
distilled  in  an  alembic  whose  capital  and  condensing  worm  are  of  silver ;  and  to 
make  it  very  fine,  it  may  be  afterwards  infused  over  a  little  pure  animal  charcoal — 
the  well-washed  residuum  of  the  Prussian-blue-works  black. 


from  the 

liquor  to 

On  eva- 

beautiful 


'] 


ACTINISM. 


n 


An  excise  duty  of  2d.  is  levied  on  every  gallon  of  the  above  proof  vinegar.  Its 
strength  is  not,  however,  estimated  directly  by  its  specific  gravity,  but  by  the  specific 
gravity  which  it  assumes  when  saturated  with  quicklime.  The  decimal  fraction  of  the 
specific  gravity  of  the  calcareous  acetate  is  very  nearly  the  double  of  that  of  the  pure 
vinegar;  or,  1*009  in  vinegar  becomes  1*018  in  acetate  of  lime.  The  vinegar  of  malt 
contains  so  much  mucilage  or  gluten,  that  when  it  has  only  the  same  acid  strength  as 
the  above,  it  has  a  density  of  1.0014,  but  it  becomes  only  1*023  when  converted  into 
acetate  of  lime :  indeed,  0*005  of  Us  density  is  due  to  mucilaginous  matter.  This  fact 
shows  the  fallacy  of  trusting  to  the  hydrometer  for  determining  the  strength  of  vinegars, 
which  may  be  more  or  less  loaded  with  vegetable  gluten.  The  proper  test  of  this,  as  of 
all  other  acids,  is,  the  quantity  of  alkaline  matter  which  a  given  weight  or  measure  of  it 
will  saturate.  For  this  purpose  the  bicarbonate  of  potash,  commonly  called,  in  the 
London  shops,  carbonate,  may  be  employed  very  conveniently.  As  it  is  a  very  uniform 
substance,  and  its  atomic  weight,  by  the  hydrogen  radix,  is  100*584,  while  the  atomic 
weight  of  acetic  acid,  by  the  same  radix,  is  51*563,  if  we  estimate  2  grains  of  the  bicar- 
bonate as  equivalent  to  1  of  the  real  acid,  we  shall  commit  no  appreciable  error.  Hence, 
a  solution  of  the  carbonate  containing  200  grains  in  100  measures,  will  form  an  aceti- 
meter  of  the  most  perfect  and  convenient  kind ;  for  the  measures  of  test  liquid  expended 
in  saturating  any  measure, — for  instance,  an  ounce  or  1000  grains  of  acid, — will  indi- 
cate the  number  of  grains  of  real  acetic  acid  in  that  quantity.  Thus,  1000  grains  of  the 
above  proof,  would  require  50  measures  of  the  acetimetrical  alkaline  solution,  showing 
that  it  contains  50  grains  of  real  acetic  acid  in  1000,  or  5  per  cent. 

It  is  common  to  add  to  purified  wood  vinegar,  a  little  acetic  ether,  or  caramelized 
(burnt)  sugar  to  color  it,  also,  in  France,  even  wine,  to  flavor  it.  Its  blanching  effect 
upon  red  cabbage,  which  it  has  been  employed  to  pickle,  is  owing  to  a  little  sulphurous 
acid.  This  may  be  removed  by  redistillation  with  peroxyde  of  manganese.  Indeed, 
Stoltze  professes  to  purify  the  pyroligneous  acid  solely  by  distilling  it  with  peroxyde  of 
manganese,  and  then  digesting  it  with  bruised  wood  charcoal ;  or  by  distilling  it  with  a 
mixture  of  sulphuric  acid  and  manganese.  But  much  acid  is  lost  in  this  case  by  the  for- 
mation of  acetate  of  that  metal. 

Birch  and  beech  afford  most  pyroligneous  acid,  and  pine  the  least.  It  is  exclusively 
employed  in  the  arts,  for  most  purposes  of  which  it  need  not  be  very  highly  purified. 
It  is  much  used  in  calico  printing,  for  preparing  acetate  of  iron  called  Iron  Liquor,  and 
acetate  of  alumina,  called  Red  Liquor  ;  which  see.  It  serves  also  to  make  sugar  of 
lead ;  yet  when  it  contains  its  usual  quantity,  after  rectification  of  tarry  matter,  the 
acetate  of  lead  will  hardly  crystallize,  but  forms  cauliflower  concretions.  This  evil  may 
be  remedied,  I  believe,  by  boiling  the  saline  solution  with  a  very  little  nitric  acid,  which 
causes  the  precipitation  of  a  brown  granular  substance,  and  gives  the  liquor  a  reddish 
tinge.  The  solution  being  afterwards  treated  with  bruised  charcoal,  becomes  colorless, 
and  furnishes  regular  crystals  of  acetate  or  sugar  of  lead. 

Pyroligneous  acid  possesses,  in  a  very  eminent  degree,  anti-putrescent  properties.  Flesk 
steeped  in  it  for  a  few  hours  may  be  afterwards  dried  in  the  air  without  corrupting;  but 
it  becomes  hard,  and  somewhat  leather-like :  so  that  this  mode  of  preservation  does  not 
answer  well  for  butcher's  meat.  Fish  are  sometimes  cured  with  it.  See  Pvro-acetic 
Spirit;  Pyroxilic  Ether;  Pyroxolic  Spirit  ;  Pyroligneous  Acid  and  Vinegar. 

In  1838,  2,628,978  gallons  of  vinegar  paid  duty  in  England;  in  1839,  2,939,665; 
and  in  1840,  3,021,130;  upon  which  the  gross  amount  of  dutv  was,  respectively, 
21,908/.  3«. ;  24,448/.  17s.  &d. ;  and  25,978/.  12s.  9<f. 

In  Scotland,  in  the  same  years,  15,626  gallons;  14,532;  and  12,967  ;  on  which  the 
duty  charged  was,  respectively,  130/.  4«.  4d. ;  121/.  2«. ;  and  111/.  19s.  Id. 

In  Ireland,  in  the  same  years,  48,158  gallons;  50,508;  and  56,812;  on  which  the 
duty  charged  was  401/.  6s.  4s. ;  420/.  18s. ;  and  489/.  12s. 

ACETIMETER.     An  apparatus  for  determining  the  strength  of  vinegar.     See  the 
preceding  article  for  a  description  of  my  simple  method  of  acetimetry. 
ACETONE     The  new  chemical  name  of  pyro-acetic  spirit. 

ACID  OF  ARSENIC.  {Acide  arsenique,  Fr. ;  Arseniksaure,  Germ.)  See  AusEXia 
ACIDS.  A  class  of  chemical  substances  characterized  by  the  property  of  combining 
with  and  neutralizing  the  alkaline  and  other  bases,  and  of  thereby  forming  a  peculiar 
class  of  bodies  called  salts.  The  acids  which  constitute  objects  of  special  manufacture 
for  commercial  purposes  are  the  following : — acetic,  arsenious,  carbonic,  chromic,  citric, 
hydrocyanic,  malic,  muriatic,  nitric,  oxalic,  phosphoric,  sulphuric,  tartaric,  which  see. 
ACI DIMETER.     See  Alkalimeter. 

ACROSPIRE  {Plumule,  Fr. ;  Blattkeim,  Germ.)  That  part  of  a  germinating  seed 
which  botanists  call  the  plumula,  or  plumes.     See  Beer  and  M.\lt. 

ACTINISM.  Some  years  ago,  Mr.  R.  Hunt  announced  that  he  had  discovered  that, 
associated  with  the  light  and  heat  derived  from  the  sun,  there  is  another  principle  most 
active  in  producing  changes  in  the  organic  and  inorganic  worlds,  which  he  has  called 


14 


ADIPOCIRE. 


ALABASTER. 


15 


Actinism,  from  the  Greek  for  a  ray  of  the  sun.  He  has  given  the  following  striking 
evidences  of  the  truth  of  his  discovery,  derived  from  the  vegetable  world.  That  the 
actinic  principle  was  necessary  to  germination  was  shown  by  the  fact,  that  seeds  placed 
under  the  influence  of  the  solar  rays  transmitted  through  yellow  glass  would  not  ger- 
minate, because  yellow  glass  prevents  the  passage  of  the  actinic  piinciple.  Accord- 
ingly, during  spring  the  solar  beam  contained  a  larger  amount  of  the  actinic  principle 
than  at  any  other,  because  it  was  necessary  at  that  season  for  the  germination  of  seeds 
and  the  development  of  buds.  In  summer,  again,  there  was  a  lai^e  proportion  of  the 
light-giving  principle  necessary  to  the  formation  of  the  woody  portions  of  plants;  and 
towards  autumn  the  calorific  heat  giving  or  ripening  principle  of  the  solar  rays  in- 
creased. It  resulted  from  these  principles  that  the  recent  use  in  greenhouses  of  white 
German  sheet  glass  was  most  objectionable.  Under  this  kind  of  glass,  plants  were 
subject  to  an  injurious  solar  influence  which  they  had  not  suffered  under  the  old  crown 
glass.  It  became  therefore  necessary  to  discover  some  method  to  cut  off  those  para- 
thermic  rays,  which,  passing  through  the  white  glass,  scorched  and  browned  particular 
portions  of  the  leaves,  without  cutting  off  the  other  portions  of  the  rays  which  were 
necessary  to  the  growth  of  the  plant.  With  this  view  Mr.  Hunt  has  devised  and 
applied  at  the  Kew  observatory  a  green  glass  stained  with  oxide  of  copper,  which 
effectually  excludes  t^ie  injurious  parathermic  rays,  while  it  admits  the  other  solar 
rays  necessary  for  the  plant,  as  freely  as  ordinary  white  glass.  In  the  manufacture  of 
this  green  glass  it  was  essential  that  no  manganese  should  be  used,  as  was  the  case  in 
white  glass.  If  manganese  were  used,  the  glass  would  after  awhile  assume  a  pinkish 
hue,  which  would  more  freely  admit  the  burning  rays. 

ADDITIONS.  Such  articles  as  are  added  to  the  fermenting  wash  of  the  distiller  are 
distinguished  by  this  trivial  name. 

ADIPOCIRE.  Fr.  (Fettwachs,  Germ.)  The  fatty  matter  generated  in  dead  bodies 
buried  under  peculiar  circumslances.  In  1786  and  1787,  when  the  churchyard  of  the 
Innocents,  at  Paris,  was  cleaned  out,  and  the  bones  transported  to  the  catacombs,  it  was 
discovered  that  not  a  few  of  the  cadavres  were  converted  into  a  saponaceous  white  sub- 
stance, more  especially  many  of  those  which  had  been  interred  for  fifteen  years  in  one 
pit,  to  the  amount  of  1500,  in  coffins  closely  packed  together.  These  bodies  were  flat- 
tened, in  consequence  of  their  mutual  pressure;  and,  though  they  generally  retained 
their  shape,  there  was  deposited  round  the  bones  of  several  a  grayish  white,  somewhat 
soft,  flexible  substance.  Fourcroy  presented  to  the  Academy  of  Sciences,  in  1789,  a  com- 
prehensive memoir  upon  this  phenomenon,  which  appeared  to  prove  that  the  fatty  body 
was  an  ammoniacal  soap,  containing  phosphate  of  lime ;  that  the  fat  was  similar  to  sper- 
maceti, as  it  assumed  on  slow  cooling  a  foliated  crystalline  structure ;  as  also  to  wax,  as, 
when  rapidly  cooled,  it  became  granular  :  hence  he  called  it  jSdipocire.  Its  melting  point 
was  52-5°  C.  (126*5°  Fahr.).  He  likewise  compared  this  soap  to  the  fat  of  gall-stones, 
and  supposed  it  to  be  a  natural  product  of  the  slow  decomposition  of  all  animal  matter, 
except  bones,  nails,  and  hairs. 

This  substance  was  again  examined  by  Chevreul  in  1812,  and  was  found  by  him  to 
contain  margaric  acid,  oleic  acid,  combined  with  a  yellow  coloring,  odorous  matter,  be- 
sides ammonia,  a  little  lime,  potash,  oxyde  of  iron,  salts  of  lactic  acid,  an  azotized  sub- 
stance ;  and  was  therefore  considered  as  a  combinalion  of  margaric  and  oleic  acids,  in 
variable  proportions  (whence  arose  its  variable  fusibility),  but  that  it  was  not  analogous 
with  either  spermaceti  or  cholesterine  (gallstones).  These  fat  acids  are  obviously  gene- 
rated by  the  reaction  of  the  ammonia  upon  the  margarine  and  oleine,  though  they  even- 
tually lose  the  greater  part  of  that  volatile  alkali. 

According  to  the  views  of  both  Gay  Lussac  and  Chevreul,  this  adipocire  proceeds 
solely  from  the  pre-existing  fat  of  the  dead  body,  and  not  from  the  flesh,  tendons,  or  car- 
tilages, as  had  been  previously  imagined ;  which  had  led  to  some  expensive  and  abortive 
attempts,  upon  the  great  scale  of  manufacture,  to  convert  the  dead  bodies  of  cattle  into 
adipocire,  for  the  purposes  of  the  candle-maker  or  soap-boiler,  by  exposing  them  for  some 
time  to  the  action  of  moisture. 

Von  Hartkol  made  experiments  during  25  years  upon  this  subject,  from  which  he 
inferred,  that  there  is  no  formation  of  adipocire  in  bodies  buried  in  dry  ground ;  that 
in  moist  earth  the  fat  of  the  dead  body  does  not  increase,  but  changes  into  a  fetid 
saponaceous  substance,  incapable  of  being  worked  into  either  soap  or  candles ;  that  the 
dead  bodies  of  mammalia  immersed  in  running  water,  leave  behind  after  3  years  a  pure 
fat,  which  is  more  abundant  from  young  than  from  old  anmials ;  that  the  intestines 
aflbrd  more  fat  than  the  muscles;  that  from  this  fat,  without  any  purification,  candles 
may  be  made,  as  void  of  smell,  as  hard,  and  as  white,  as  from  bleached  wax ;  that  from 
cadavers  immersed  for  3  years  in  stagnant  water,  more  fat  is  procured  than  from  those 
in  running  water,  but  that  it  needs  to  be  purified  before  it  can  be  made  into  soap  or 
candles. 

The  cause  of  the  difference  between  Harikol's  and  Chevreul's  results  cannot  be 
assigned,  as  the  latter  has  not  published  his  promised  remarks  upon  the  subject.     At 


^P  any  rate,  dead  animal  matter  can  be   worked  up  more  profitably  than  in  making 

artificial  adipocire. 

ADIT.  The  horizontal  entrance  of  a  mine.  It  is  sometimes  called  the  drift  See 
Mining  and  Metallurgy. 

ADULTERATION.    The  debasing  any  product  of  manufacture,  especially  chemi- 
cal, by  the  introduction  of  cheap  materials.     The  art  of  ascertaining  the  genuineness 
of  the  several  products  will  be  taught  under  the  specific  objects  of  manufacture 
^ETHEPu     See  Ether. 

AFFINITY.  The  chemical  terra  denoting  the  peculiar  attractive  force  which  pro- 
duces the  combination  of  dissimilar  substances ;  such  as  of  an  alkali  with  an  acid,  or 
of  sulphur  with  a  metal.  It  is  often  called  elective  attraction,  to  distinguish  it  from 
corpuscular  or  cohesive  attraction,  by  which  particles  of  like  kinds  of  matter  are  com- 
bined ;  and  because  it  displays  the  power  of  selecting  its  preferable  associates.  Ita 
full  discussion  belongs  to  chemistry. 

AGARIC.     A  species  of  boletus  or  fungus,  which  grows  in  dunghills;  with  the 
salts  of  iron  it  affords  a  black  dye.     It  is  said  to  be  convertible  into  a  kind  of  china  ink, 
AGATE.    A  silicious  mineral  which  is  cut  into  seals  and  other  forms  for  the  coarser 
kinds  of  jewellery.     See  Gem. 
AIR.    See  Ventilation. 

ALABASTER,  is  a  stone  usually  white,  and  soft  enough  to  be  scratched  by  iron. 
There  are  two  kinds  of  it :  the  gypseous,  which  is  merely  a  natural  semi-crystalline  sul- 
phate of  lime  ;  and  the  calcareous  alabaster,  which  is  a  carbonate  of  lime.  The  oriental 
alabaster  is  always  of  the  latter  kind,  and  is  most  esteemed,  because  it  is  agreeably 
variegated  with  lively  colors,  and  especially  with  zones  of  honey-yellow,  yellow-br^wn 
red,  &c. ;  it  is,  moreover,  susceptible  of  taking  a  marble  polish. 

The  firieness  of  the  grain  of  alabaster,  the  uniformity  of  its  texture,  the  beauty  of  its 
polished  surface,  and  its  semi-transparency,  are  the  qualities  which  render  it  valuable  to 
the  sculptor  and  to  the  manufacturer  of  ornamental  toys. 

The  limestone  alabaster  is  frequently  found  as  a  yellowish-white  deposite  in  certain 
fountains.  The  most  celebrated  spring  of  this  kind  is  that  of  the  baths  of  San  Filippo, 
in  Tuscany.  The  water,  almost  boiling  hot,  runs  over  an  enormous  mass  of  stalactites* 
which  it  has  formed,  and  holds  the  carbonate  of  lime  in  solution  by  means  of  sulphuret- 
ed  hydrogen  (according  to  M.  Alexandre  Brongniard),  which  escapes  by  contact  of  the 
atmosphere.  Advantage  has  been  taken  of  this  property  to  make  basso  relievos  of  con- 
siderable hardness,  by  placing  moulds  of  sulphur  very  obliquely,  or  almost  upright,  in 
wooden  tubs  open  at  the  bottom.  These  tubs  are  surmounted  at  the  top  with  a  large 
wooden  cross.  The  water  of  the  spring,  after  having  deposited  in  an  external  conduit 
or  cistern  the  coarser  sedunent,  is  made  to  flow  upon  this  wooden  cross,  where  it  is 
scattered  into  little  streamlets,  and  thence  lets  fall,  upon  the  sulphur  casts,  a  precipitate 
80  much  the  finer  the  more  nearly  vertical  the  mould.  From  one  to  four  months  are  re- 
quired for  this  operation,  according  to  the  thickness  of  the  deposited  crust.  By  analo- 
gous processes,  the  artists  have  succeeded  in  moulding  vases,  figures  of  animals,  and 
other  objects,  in  relief,  of  every  different  form,  which  require  only  to  be  trimmed  a  little 
and  afterwards  polished.  * 

The  common  alabaster  is  composed  of  sulphuric  acid  and  lime,  though  some  kinds  of 
It  effervesce  with  acids,  and  therefore  contain  some  carbonate  of  lime.  This  alabaster 
occurs  m  many  different  colors,  and  of  very  different  degrees  of  hardness,  but  it  is  always 
softer  than  marble.  It  forms,  usuaUy,  the  lowest  beds  of  the  gypsum  quarries.  The 
sculptors  prefer  the  hardest,  the  whitest,  and  those  of  a  granular  texture,  like  Carrara 
marble,,  and  so  like  that  they  can  only  be  distinguished  bv  the  hardness 

The  alabaster  is  worked  with  the  same  tools  as  marble;  and  as  it  is  many  degrees 
sorter  It  IS  so  much  the  more  easily  cut;  but  it  is  more  ditficult  to  polish,  from  its  little 
solidity.  After  it  has  been  fashioned  into  the  desired  form,  and  smoothed  down  with 
pumice  stone.  It  IS  polished  with  a  pap-like  mixture  of  chalk,  soap,  and  milk;  and,  last 
of  all,  finished  by  friction  with  flannel.     It  is  apt  to  acquire  a  yellowish  tinge. 

Besides  the  harder  kinds,  employed  for  the  sculpture  of  large  figures,  there  is  a  softer 
alabaster,  pure  white  and  semi-transparent,  from  which  small  ornamental  objects  are 
made,  such  as  boxes,  vases,  lamps,  stands  of  time-pieces,  &c.  This  branch  of  business 
\l^.  ^i^r^^ntu'^  m  Florence,  Leghorn,  Milan,  &c.,  and  employs  a  great  many  turning 
lathes.  Of  aU  the  alabasters,  the  Florentine  merits  the  preference,  on  account  of  i'ls  beauty 
ana  umlormity,  so  that  it  may  be  fashioned  into  figures  of  considerable  size:  for  which 
purpose  there  are  large  work-shops  where  it  is  cut  with  steel  saws  into  blocks  and  mas- 
ses  ot  various  shapes.  Other  sorts  of  gypsum,  such  as  that  of  Salzburg  and  Austria, 
contain  sand  veins,  and  hard  nodules,  and  require  to  be  quarried  by  cleavhig  and  blasUn- 


n 


ALCOHOL. 


ALCOHOL. 


n 


operations  which  are  apt  to  crack  it,  and  unfit  it  for  nil  delicate  objects  of  sculpture. 
It  is  besides  of  a  gray  shade,  and  often  stained  with  darker  colors. 

The  alabaster  best  adapted  for  the  fine  arts  is  pretty  white  when  newly  broken,  and 
becomes  whiter  on  the  surface  by  drying.  It  may  be  easily  cut  with  the  knife  or  chisel, 
and  formed  into  many  pleasing  shapes  by  suitable  steel  tools.  It  is  worked  either  by 
the  hand  alone,  or  with  the  aid  of  a  turning  lathe.  The  turning  tools  should  not  be  too 
thin,  or  sharp-edged ;  but  such  as  are  employed  for  ivory  and  brass  are  most  suitable 
for  alabaster,  and  are  chiefly  used  to  shave  and  to  scratch  the  surface.  The  objects 
which  cannot  be  turned  may  be  fjishioned  by  the  rasping  tools,  or  with  minute  files, 
such  as  variegated  foliage.  Fine  chisels  and  graving  tools  are  also  used  for  the  better 
pieces  of  statuary. 

For  polishing  such  works,  a  peculiar  process  is  required;  pumice  stone,  in  fine 
powder,  serves  to  smooth  down  the  surfaces  very  well,  but  it  soils  the  whiteness  of  the 
alabaster.  To  take  away  the  unevenness  and  roughness,  dried  shave-grass  {eqiiisctum) 
answers  best.  Frictions  with  this  plant  and  water  polish  down  the  asperities  left  by 
the  chisel :  the  fine  streaks  left  by  the  ^rass  may  be  removed  by  rubbing  the  pieces 
with  slaked  lime,  finely  pulverized  and  sifted,  made  into  a  paste  or  putty  with  water. 
The  polish  and  satin-lustre  of  the  surface  are  communicated  by  friction,  first  with  soap- 
water  and  lime,  and  finally  with  powdered  and  elutriated  talc  or  French  chalk. 

Such  articles  as  consist  of  several  pieces  are  joined  by  a  cement  composed  of  quick- 
lime and  white  of  egg,  or  of  well-calcined  and  well-sifted  Paris  plaster,  mixed  with 
the  least  possible  quantity  of  water. 

Alabaster  objects  are  liable  to  become  yellow  by  keeping,  and  are  especially  injured 
by  smoke,  dust,  <fec.  They  may  be  in  some  measure  restored  by  washing  with  soap 
and  water,  then  with  clear  water,  and  again  polished  with  shave-grass.  Grease-spots 
may  be  removed  either  by  rubbing  with  talc  powder,  or  with  oil  of  turpentine. 

The  surface  of  alabaster  may  be  etched  by  covering  over  the  parts  that  are  not  to 
be  touched  with  a  solution  of  wax  in  oil  of  turpentine,  thickened  with  white  lead, 
and  immersing  the  articles  in  pure  water  after  the  varnish  has  set.  The  action  of 
the  water  is  continued  from  20  to  50  hours,  more  or  less,  according  to  the  depth  to 
which  the  etching  is  to  be  cut  After  removing  the  varnish  with  oil  of  turpentine, 
the  etched  places,  which  are  necessarily  deprived  of  their  polish,  should  be  rubbed 
with  a  brush  dipped  in  finely-powdered  gypsum,  which  gives  a  kind  of  opacity,  con- 
trasting well  Avith  the  rest  of  the  surface. 

Alabaster  may  be  stained  either  with  metallic  solutions,  with  spirituous  tinctures 
of  dyeing  plants,  or  with  colored  oils,  in  the  same  way  as  marbles. 

Tliis  substance  has  been  hardened,  it  is  said,  by  exposing  it  to  the  heat  of  a  baker's 
oven  for  10  or  20  hours,  after  taking  it  out  of  the  quarr}',  and  giving  it  the  figure, 
roughly,  which  it  is  intended  to  have.  After  this  exposure,  it  must  be  dipped  for  two 
minutes  in  running  water;  when  it  is  cold,  it  must  be  dipped  a  second  time  for  the 
same  period.  On  being  exposed  to  the  air  for  a  few  days,  alabaster  so  treated  ac- 
quires a  marble-like  hardness.  I  doubt  the  truth  of  this  statement.  I  believe  a  much 
better  means  of  induration  would  be  by  soaking  it  in  solution  of  alum.  Alabaster  is 
by  the  mineralogist  considered  as  hydrous  gypsum;  and  consists  of  one  atom  of  sul- 
phuric acid,  one  atom  of  lime,  and  two  atoms  of  water. 

ALBATA.  A  white  metal  like  silver;  see  Copper,  of  which  it  is  an  alloy  with 
nickel  and  zinc. 

ALBUM  GR-t'ECUM.  The  white  dung  of  dogs,  sometimes  used  to  soften  leather 
in  the  process  of  dressing  it  after  the  depilatory  action  of  lime.  It  is  essentially  phos- 
phate of  lime  and  mucus. 

ALBUMIXE,  an  animal  product,  like  white  of  egg,  which  is  diffused  through  the 
whole  body,  and  is  on  account  of  the  multifarious  uses  which  it  subserves  in  the  vital 
economy  called  Proteine.  It  consists  of  carbon  55*0;  hydrogen  7*07;  oxygen  22'0; 
azote  15-92. 

ALCARAZZAS.  A  species  of  porous  earthenware,  made  in  Spain,  for  cooling 
liquors.  Alcarazzas  are  made  of  a  sandy  marl,  made  up  into  a  dough,  with  a  solution 
of  salt,  and  very  little  fired.  M.  Fourmy  has  mounted  a  factory  of  them  in  Paris  under 
the  Greek  title  of  Ili/groceramen. 

ALCOHOL  The  well-known  intoxicating  liquor  procured  by  distillation  from  vari- 
ous vegetable  juices,  and  infusions  of  a  saccharine  nature,  which  have  undergone  the  vi- 
nous fermentation.  Common  alcohol,  or  proof  spirit,  as  it  is  called,  contains  about  one-half 
its  weight  of  water.  It  may  be  concentrated  till  its  specific  gravity  becomes  so  low  as 
0'825,  by  simple  redistillation  at  a  steam  or  water-bath  heat ;  but  to  make  it  stronger,  we 
must  mix  with  it,  in  the  still  or  retort,  dry  carbonate  of  potash,  chloride  of  calcium, 
dry  lime,  or  some  other  substances  strongly  attractive  of  water,  and  then  it  may  be  ob- 
tained of  a  specific  gravity  so  low  as  079  lat  16°  Reaumur  (68°  Fahr.),  water  being  I'OOa 


At  0-825,  it  contains,  still,  li  per  cent,  of  water;  and  in  this  state  it  is  as  volatile  as 
absolute  alcohol,  on  account  of  the  inferior  density  of  the  aqueous  vapor,  compared  to 
the  alcohohc.  Indeed,  according  to  Yehn  and  Fuchs,  the  boiling  point  of  anhydrous 
alcohol  is  higher  than  of  that  which  contains  2  or  3  per  cent,  of  water;  hence,  in  the 
distillation  of  alcohol  of  94  per  cent.,  the  first  portions  that  come  over  are  more  aqueous 
than  the  following.  Absolute  alcohol  has  its  boiling  point  at  168i°  Fahr. ;  but  when 
It  holds  more  than  6  per  cent,  of  water,  the  first  portions  that  come  over  are  richest  in 
alcohol,  and  the  temperature  of  the  boiling  point,  or  of  the  spirituous  vapor,  is  always 
higher  the  longer  the  distUlation  continues.  According  to  Groning's  researches,  the 
following  temperatures  of  the  alcoholic  vapors  correspond  to  the  accompanying  contents 
of  alcohol  m  per  centage  of  volume,  which  are  disengaged  in  the  boiling  of  the  spirituous 


r 


Alcoholic  con- 

Alcoholic con- 

Tempermture. 

tent  of  the 

tent  of  the  boil- 

vapor. 

in;  liquid. 

Fahr.  170-0 

93 

92 

171-8 

92 

90 

172 

91 

85 

172-8 

90i 

80 

174 

90 

70 

174-6 

89 

70 

176 

87 

65 

178-3 

85 

50 

180-8 

82 

40 

183 

80 

35 

185 

78 

30 

187-4 

76 

25 

Temperature. 


I 


Fahr. 


189 
192 
164 
196 
198 
201 
203 
205 
207 
210 
212 


Alcoholic   con- 
tent of  the 
vapor. 


71 
68 
66 
61 
65 
50 
42 
36 
28 
13 
0 


Alcoholic  con- 
tent of  the  boil- 
ing liquid. 


20 

18 

15 

12 

10 

7 

5 

3 

2 

1 

0 


Groning  undertook  this  investigation  in  order  to  employ  the  thermometer  as  an 
alcohol-meter  in  the  distillation  of  spirits:  for  which  pu^se  he  thruTttTe  bu?b  o? 
the  thermometer  through  a  cork,  inserted  into  a  tube  fixed^in  the  capital  of  the  stia 
l^Lt  f^l-^K^-^r'S^^^''  o°ght  also  to  be  considered  in  making  comparat^^^^^ 
^th  th'  f  ''  ^*°^  ^T.1:  ^y  ^^''  °^^^^^^'  *^«  *l««^oli«  <'ontelt  may  be  compared 
TXl     1,  1  P^'w-lw-^^  ^^'  ^t^""^  *^^^  P^««^«  «^«^  ^t  any  time,  so,  also,  theTntent 

El  sfai  bulb   Hklr.f  nf        If  "."  r''"'"''*  "PP^ratus,  consisting  of  a  large  cylin- 

ritTh  r'""**/  '•J  '  counterweight     Coucentrio  wStC^ulleya  gmlTd  flTt 
ring  of  brass  was  fixea,  on  whieh  an  index  traversed  with  the  pulley  as  ft  wLmovid 

q  ^atttTe'e^r  ilthXth7^:i\^^^^^^ 
Se'e  Vffl'oVtr  ll^"  'TV'""-  j^7*h:i:ttru^e':ttt;s3et 


Temp.  Fahr. 


178-60 

179-75 

180-4 

182-00 

183-40 


8p.  Gr. 


Temp.  Fahr. 


0-920  P. 
0-9821  10  U. 
0-9420  20 
0-9516  30 
0-960    40 


185-6 
189-0 
191-8 
196-4 
202-0 


Sp.  Gr. 


0-9665 
0-9729 
0-9786 
0-9850 
0-992 


60  U.  P. 

60 
70 
80 
90 


?h:B^tLi':x'is:',s:d'"ar3"  u  p%:nor°^*'^"""f  ^  ^-  "n*«»'  p«-f  ^p'""  of 

nol,  vol.  7.  p.  166   th°r7[8»de;,iii  ,         """J«:j'™»f— ./»  'he  Phanmceutical  Joar- 

The  first^o    the  folTowinft^o  t^w.?''^  w,th  engravings,  of  the  two  in.tr«me„ts. 

..rengths  may  be  oompa^:riir»^tV„Ve'|iv'en'X?r"''  "'"""""  "''^"'"™' 


■B 


18 

ALCOHOL. 

• 

Groning. 

Telln. 

Alcohol, 

Boiling 

Alcohol 

Boiling 

in  100. 

Point 

* 

in  100. 

Point. 

6 

96-3"  C.                          94 

76-97°  C. 

10 

92-9                                 95 

76-99 

15 

91-0                                 96 

76-92 

20 

89-1                                 9*7 

76-85 

26 

87-6 

98 

76-86 

80 

86-2 
85-0 
841 

99 

76-90 

86 

100 

77-02 

40 

45 

83-4 

50 

83-1 

55 

eo 

82-2 

81-9 

65 

81-6 

10 

80-9 

75 

80-3 

80 

79-7 

' 

85 

79-4 

90 

79-0 

95 

78-4 

Proofspiritofsp.gr.  0-92  at  60°  Fahr.  consists  of  absolute  alcohol  of  gravity  0-794, 
and  of  distilled  water  very  near  equal  weights ;  but  in  volumes,  of  126  of  alcohol  and 
100  of  water;  therefore  100  measures  of  such  spirits  contain  65-75  of  the  alcohol 

/126\ 
"  (m/       ^^  ^^^  ^^^^^  of  Gay  Lussac,  spirits  that  contain  55*75  of  absolute  al- 
cohol have  a  specific  gravity  of  0-9218  instead  of  09200;  while  spirits  of  0-9200,  ac- 
cording to  Gay  Lussac,  contam  56-66  in  100  by  volume.     By  the  table  of  Tralles,  spirita 

of  0-825  contain  92-43  of  the  said  alcohol;  and  hence  ^^^  +  ^6-66  _gQ.gJ  ^^  Gilpin'» 

92-43 
alcohol  by  Gay  Lussac ;  whereas  by  Gilpin's  table,  spirits  of  0-9200  contain  100  of 

alcohol  of  0-825  +  81  -2  of  water  by  weight :  and  ^^^  =121-2121  by  volume.      Again. 

0-825  -^  ^    ^ 

121-2121+81-2=202-2121;  1212121  divided  by  2022121  gives  a  quotient  of  59-88  as 
the  alcohol  of  0-825  in  the  100  by  volume.  Now  as  606  by  Gay  Lussac's  table  ex- 
ceeds 59  88  by  0-72,  there  must  be  an  error;  most  probably  on  the  side  of  the  French 
chemist. 

The  temperature,  corresponding  to  a  certain  per  centage  of  afcohol  in  vapor,  sngsrests 
the  employment  of  a  convenient  method  for  obtaininsr,  at  one  process,  a  spirit  as  free  from 
water  as  it  can  be  made  by  mere  distillation.  We  place  over  the  top  of  the  capital  a 
water-baih,  and  lead  up  through  U  a  spiral  pipe  from  the  still,  which  there  passes  oblique- 
ly downwards,  and  proceeds  to  the  refrigeratory.  If  this  bath  be  maintained,  by  a  constant 
influx  of  cold  water,  at  a  certain  temperature,  only  the  alcoholic  vapor  corresponding  to 
that  temperature  will  pass  over,  and  the  rest  will  be  recondensed  and  returned  into  the 
still.  If  we  keep  the  temperature  of  the  water  at  174°,  for  example,  the  spirituous  va- 
por which  passes  over  will  contain  90  per  cent,  of  absolute  alcohol,  according  to  the 
preceding-  table.  The  skilful  use  of  this  principle  constitutes  the  main  improvement  in 
modern  distilleries.     See  Distillation  and  Still. 

Another  method  for  concentrating  alcohol  is  that  discovered  by  Summering,  founded 
upon  the  property  of  ox  bladders  to  allow  water  to  pass  through  and  evaporate  out  of 
them,  but  not  to  permit  alcohol  to  transpire,  or  only  in  a  slight  degree.  Hence,  if  an 
ox's  bladder  is  filled  with  spirit  of  wine,  well  tied  at  the  mouth,  and  suspended  in  a  warm 

I)lace,  the  water  will  continually  exhale,  and  the  alcohol  will  become  nearly  anhydrous ; 
or  in  this  way  alcohol  of  97  or  98  per  cent,  may  be  obtamed. 

According  to  Siimmering,  we  should  take  for  this  purpose  the  bladder  of  an  ox  or  a  calf^ 
soak  it  for  some  time  in  water,  then  inflate  it  and  free  it  from  the  fat  and  the  attached 
vessels;  which  is  to  be  also  done  to  the  other  surface,  by  turning  it  inside  out.  After  it 
is  again  inflated  and  dried,  we  must  smear  over  the  outer  side  twice,  and  the  inner  side  four 
times,  with  a  solution  of  isinglass,  by  which  its  texture  is  made  closer,  and  the  concen- 
tration of  the  alcohol  goes  on  better.    A  bladder  so  prepared  may  serve  more  than  a 


• 


ALCOHOL. 


19 


hundred  times.  It  mast  be  charged  with  the  spirits  to  be  concentrated,  leavini?  a  small 
^^aZT:y\  "  *«"  to  be  tightly  bound  It  the  mo„th.  and  suspended  ^awTr" 
situation,  at  atempcrature  of  1220  Fahr.,  oyer  a  sand-bath,  or  in  the  neiehborhood 
tlZZL.V'f  ^^'^o.-'.f  tt^  bladder  remains  moist  with  the  water  as  !ng  1  the 
fLf  c.         T*f '"^'l  'P'"'  ■'  Sfeater  than  0.982.  Weak  spirit  loses  its  water  quicker 

.nf,.H  T"^/*""  ";  '""T  «  *^  '2  •"»■"  ">«  ^'^ohol  "«>•  be  concentrated  when  a 
«u  table  heat  IS  employed.  This  economical  method  is  particularly  appfieTbirh,  "l^ 
taming  alcohol  for  tfie  preparation  of  varnishes.     When  the  alcohoHs  to  serve  fOT 

tl  e  bird.  rr\'trf  *"  ^^r,^  "^  -Ji'ti""""".  f-^™  "e^tain  matters  dissolved  out  of 
wL„  ,5,  ■^  .1?  ."'  """^  bkewise  be  strengthened,  as  Sommering  has  ascertained. 

Tome  iito  crtae   w  ,r?^'l?  "'.'  "^l^'  ''  '"""<'  "'"^  "'">  "  ^addfr  whfch  doe  "not 
t"i:cI  "rlfutl^S  !:  1 1  :'"  T^^""^  ""<'  """>  a^tated  tillThe^t  rdlsSveA 

msmmmmm 

salts  of  strLt  a  ?n  aTcohof  btrn  S'  -      ■""  '"  '«  ^"""l  """"  ">*  ^"'•'""™  »' 'be 
green,  lime  redSilh,  and  btyu  ye^'ot      "''""""'  """"'  ""'"'  "'  ""^f"  ''"^  '"'^'^ 

tlieJe  eSst,fn"gAtttf with  Mn'"'"'  "",''  %«T'3f  ?«»»  »' ™'»">e  are  the  result ; 
decreasing  w.'^^I  a°g?SLr  nroiforffon'S  J?  "  "C »''>"'»  ap^  ,«  "f  ^ater,  and  thence 

for  each  determh  a  e  pronVrC  of  'wrf'^^'J  *''!^  ^H  «P^«ifi«  Suavity  be  ascertained 
this  is  done,  ^c  mavT/meanV  and  water  that  are  mixed  together.    When 

water,  detemine  Z  etiengSi  of  1^^^  e^^^^^^^^^  ^T'"^'  ^^^'^*-  '^^-- 

an  arbitrary  graduation  oorrZ^LP    K      '    }■      ^>'  ^  ^""^^^  of  specific  gravities  or  by 

determine  t^.fperceXe  o^^^^^^^^^^^^^  ^f "'"  I'^r^'l''^  ^^J^^^^'  «"^  *^"«  ^«  ^4 

areometer  inte'JiderforThisusehrs^b^^^^^  ^H^uHty.  aI 

scale  of  it  issoffraduatSTat    fsfPaZ^^^^ 

the  percentage  of  anhXus  ^16^01  fn  I     '     '''''^•' f  f  ^  immediately 

scale  graduated  accorfc  to  fhr^  V  ^'""T  '^''^^'*  ^^  "'«1""^«  ^^  «»e  liquid.  The 
alcohf Imeter  of  RichS  \nd  that  W  ?1  ?  ^^  ^T  ^^•'^^"!  ^^  ^^'^^'*'  constitutes  the 
Tralles  and  Gay  Lussac  '  ^     ^  percentage  in  volume,  the  alcoliolmeter  of 

thetefr,^  wt;f  iSit^^^^^^^^^  jr"'-  r  '^ -^^i  ™^^*'  ^^  >«  ™-t, 

Tralles  has  constructed  new  taW^^"n^^^^^  percentage  by  volume, 

proportion  is  given  by  volLe  ^^d  afrdro?"rT^?-^^'^^  5^.^^^'^'"'  ^'°  ^''''^^^  ^he 
60°  Fahr.,  has  a  spccilfc  craWtv  of  n^QJo^  ^^'S^""^  l^  ^''""'^^  ^""^  ^he  basis  which  at 

or  a  specific  grality  of  O^oifj^ 
Gilpin\alcolfol  of  0^-825  containH?  6  ni^^^^^^^  f '^'  temperature  of  60°  Fahi 

According  to  the  expS^ts  of  Tr!ll  ^  ^I  7^"^' ^^'*"'^y^''^"«  «^^«^^ 
+  37  C.  wiTh  tolerabiruniTom  tv     fl^^^^^^^^    alcohol  contracts  between-260  C.  and 
volume  of  the  alcohol.     In  tTe  ^lowi 'rt 'l^'^-';''  "^r""'^''^""  ^^  ^'^'^^^  ^^  ^he 
wards  from  the  boiling  point  by  Gay  Tusfac  '  <^««tractions  are  reckoned  down- 


I!: 


fW- 

ALCOHOL. 

Temp. 

Yolame. 

Temp. 

48°-4 
43°-4 
88°-4 
33°-4 

28°-4 

Yolame. 

Temp. 

Volume. 

78*-4 
73'-4 
68°-4 
63°-4 
68*-4 
53°-4 

1000- 
994-4 
988-6 
982-6 
976-7 
970-9 

966-8 
960-0 
964-4 
948-9 
943-6 

23°-4 

18°-4 

18° -4 

8°-4 

988-6 
934-0 
929-3 
924-6 
9190 

empyreumatic  oil,  and  carbon ;  afeorfine  ?o  the  deip^^rS  h'  if  ^^  naphthaline, 
these  producU  vary.  Anhydrous  alcohol  is  a  n„„5I^^!.  "^ ''«'"  "d  »«*"«  of  the  tube 
composed  by  a  powerful  voitaic  battery  llcohoXrn  •  ♦■" '  e  ectr  city,  but  is  de- 
mto  carbonic  ^id  and  water;  Te  water  be?n„),^  •?.,*''*.?'''''*'''>'■>«  A*™ 
parte  of  alcohol  contain  6  of  Cro^eXfeo^"S  t'"  '^  'P'?*-  ^"'''^  *« 
combustion  is  accompanied  with  VS»f  Tilf       J^i?*^  '""«'••     I"  oxymn  the 

en,aUtube,powerfuI1^1^L  Wief^U'dllt''  ""'  "'""*'   ^""''^  t^™"gh  • 

hea^rcSi:i;'S'el^r:S':ftilttt^^^^^^^ 

ide  of  uranium,  wide  of  tin  (tSse  six  hod;.,  T^"  P"''''^i'l*»'^  "=<>'>»'».  Proto/- 
oxalates  in  a  crucibleX  or  finely  ^wderedmaL.„^^  '^""""^f  ^^  '^"'^'"^  »f  their 
pUce.  «>d  continues  as^ong  as  (hrs^Sus^ri^rSts''"''"^''  '"■"'"«««»  »<*" 

water  being  considered  .,'  6C^  FaKtave  7^^  S"„f  S^^^  "'  '"'  »?-". 


Alcoholmetrical  Table  of  Tralles. 


Alcahol  in  100 

measure!  of 

spirit. 


0 

1 

s 
t 

4 
ft 
€ 
7 
8 
9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 


Specific  gravity 
■t  60O  Fahr. 


Diflference  of 
the  ep.  gr. 


9991 

9976 

9961 

9947 

9933 

9919 

9906 

9893 

9881 

9869 

9857 

9845 

9834 

9823 

9812 

9802 

9791 

9781 

9771 

9761 

9751 

9741 

9731 

9720 

9710 

9700 

9689 

9679 

9668 

9657 

9646 

9634 

9622 

9609 


Alcohol  in  100 

measures  of 

•pirit. 


15 

15 

14 

14 

14 

13 

13 

12 

12 

12 

12 

11 

11 

11 

10 

U 

10 

10 

10 

10 

10 

10 

11 

10 
10 

11 

10 

11 
II 
11 

12 
12 
13 


51 

52 

53 

54 

55 

56 

57 

58 

59 

60 

61 

62 

63 

64 

65 

66 

67 

68 

69 

70 

71 

72 

73 

74 

75 

76 

77 

78 

79 

80 

81 

82 
83 
84 


Specific  gravity 
at  60O  Fahr, 


9315 

9295 

9275 

9254 

9234 

9213 

9192 

9170 

9148 

9126 

9104 

9082 

9059 

9036 

9013 

8989 

8965 

8941 

8917 

8892 

8867 

8842 

8817 

8791 

8765 

8739 

8712 

8685 

8658 

8631 

8603 

8575 

8547 

8518 


Difference   of 
the  Bp.  gr. 


20 

20 

20 

21 

20 

21 

21 

22 

22 

22 

22 

22 

23 

23 

23 

24 

24 

24 

24 

25 

25 

25 

25 

26 

26 

26 

27 

27 
27 
27 
28 
28 
28 
29 


\ 


ALCOHOL. 
Alcoholmetrical  Table  of  Tralles  {continued). 


21 


Alcohol  in  100 

measures  of 

spirit. 


34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

46 

47 

48 

49 

50 


Specific  gravity 
at  60O  Fahr. 


9596 

9583 

9570 

9556 

9541 

9526 

9610 

9494 

9478 

9461 

9444 

9427 

9409 

9391 

9373 

9354 

9335 


Difference  of 
the  sp.  gr. 


13 
13 
13 
14 
15 
15 
16 
16 
16 
17 
17 
17 
18 
18 
18 
19 
19 


Alcohol  in  100 

measures  of 

spirit. 


85 
86 
87 
88 
89 

^ 
91 

92 

93 

94 

95 

96 

97 

98 

99 

100 


Specific  gravity 
at  eO"  Fahr. 


8488 

8458 

8428 

8397 

8365 

8332 

8299 

8265 

8230 

8194 

8157 

8118 

8077 

8034 

7988 

7939 


Difference  of 
the  sp  gr. 


30 

30 

30 

31 

32 

33 

33 

34 

35 

36 

37 

39 

41 

43 

46 

49 


Remarks  on  the  preceding  Table  of  Mcohol. 

gravty  of  the  mixtnrs^  Sv  ti,.  .™»c  '?    ^   .^  ""  "»y  determinate  specific 

fnd  the  product  r?henumb«  of  ™f„^^  pure  alcohol,  that  is,  by  7939, 

gravity  multiplied  by  100  rili  tC  ^'  f  "~''°'  '\^  """"y  Po^-xls  as  the  specific 
40  measures  of  ^coholTX'nce  there"  i!^""::;!:;"  "'^  SSlOspecific  grayity,  the?e  arc 
7939  +  40  =  31-756  Dound.,  of  «V„h^f         a  •^„„"'   ''''O"    P°""'ls   of  this   spirit 

n«cifit  gravity  3™97undsoLtt"'Lrcon!aV^"  •""""  "'  '"«  '"^'^  »' "-'^lO 

.ri^v«^K:'r'z1t%tSrl^V6"'F^ten^^^ 

alcohol  for  the  soecific  «a^t  «  ,^L.        j^''  !''*  [""""""g  taWe  gives  the  per  centage  of 

For  example  -Twe  have  a  ^S"^'?'"^  '"  ">«  r^^-^P^J'-S  tempcAtnres.    ^ 
0-9342,  the  \L^\  p4enUs  4Wr  c"ent  J.l  l'  ,'^  ^''^\  ^""'^  ^^^"8'=  8™"'?  » 
temperature  is  equSl    o    he  IpS  J^i,'''VaiT^^^  'hat 

;^:f::::^^_Thi^ble  .ay  a-soV  tpPfo?  tf^'ig^  ^rS^-th'STr  ani 


Alcohol 
per  cent. 


Temperature. 


0 
5 
10 
15 
20 
25 
30 
S5 
40 
45 
50 
55 
«0 
65 
70 
75 
80 
85 


30°  F, 


9994 

9924 

9868 

9823 

9786 

9753 

9717 

9671 

9615 

9544 

9460 

9368 

9267 

916-2 

9046 

8925 

8798 

8663 

8517 


35°  F, 

9997 

9926 

9869 

9822 

9782 

9746 

9707 

9658 

9598 

9525 

9440 

9347 

9245 

9138 

9021 

8899 

8771 

8635 

8486 


40»  F. 


45«  P. 


9997 

9998 

9926 

9926 

9868 

9867 

9820 

9817 

9777 

9772 

9738 

9729 

9695 

9684 

9644 

9629 

9581 

9563 

9506 

9486 

9420 

9399 

9325 

9302 

9222 

9198 

9113 

9088 

8996 

8970 

8873 

8847 

8744 

8716 

8606 

8577 

8455 

8425 

50*'  F, 


9997 

9925 

9865 

9813 

9766 

9720 

9672 

9614 

9546 

9467 

9378 

9279 

9174 

9003 

6944 

8820 

8688 

8547 

8395 


55<»  P. 


Alcohol 
per  cent. 


Temperature 


60«  P. 


9994 

0 

9922 

5 

9861 

10 
15 

9807 

9759 

20 

9709 

25 

9659 

30 

9599 

35 

S»528 

40 

9447 

45 

9356 

50 

9256 

55 

9150 

60 

90S8 

65 

8917 

70 

8792 

75 

8659 

80 

8517 

85 

8363 

90 

I 


9991 

9919 

9857 

9802 

9751 

9700 

9646 

9583 

9510 

9427 

93.15 

9234 

9126 

9013 

8892 

8765 

8631 

8488 

8332 


65«»  P. 


9987 

9915 

9852 

9796 

9743 

9690 

9632 

9566 

9491 

9406 

9313 

9211 

9102 

8988 

8866 

8738 

8602 

8458 

8300 


70»  p 


9991 

9909 

9845 

9788 

9733 

9678 

»618 

9549 

9472 

9385 

9290 

9187 

9076 

8962 

8839 

8710 

8573 

8427 

8268 


75«»  P 


9976 

9903 

9839 

9779 

9722 

9065 

9603 

9532 

9452 

9364 

9267 

9163 

9051 

8936 

8812 

8681 

8544 

8396 

8236 


I 


lli 


22 


ALCOHOL. 


!!!!?•  ^.^^^    l^'rr.^  ^^  ^^  ^*^^  computation  for  the  intervals.    It  is  evident  from  in- 
spection that  a  difference  of  5°  Fahr.  in  the  temperature  changes  the  specific  -ravity  ol 

H  fi-?*^r  u     **  '^'ff^i'ence  nearly  equal  to  1  volume  per  cent,  of  alcohol ;  thus  at  35" 
ana  »o   fahr.  the  very  same  specific  gravity  of  the  liquor  shows  nearly  10  volumes  oer 
cent.  01  alcohol  more  or  less ;  the  same,  for  example,  at  60  and  40  per  cent. 
•    |/*®  *™P°'"}*"p6  of  extreme  accuracy  in  determining  the  density  of  alcoholic  mixtures 
*^i  t  V"^^^^  Kingdom,  on  account  of  the  ^real  revenue  derived  from  them  to  the  Slate 
and  their  consequent  high  price  in  commerce,  induced  the  Lords  of  the  Treasury  a  few 
years  ago  to  request  the  Royal  Society  to  examine  the  construction  and  modeof  applyinsr 
Uie  instrument  now  in  use  for  ascertaining  and  charging  the  duty  on  spirits.    This  instru- 
ment,  which  is  known  and  described  in  the  law  as  Sikes's  hydrometer,  possesses,  in  many 
respects,  decided  advantages  over  thpse  formerly  in  use.     The  committee  of  the  Rov^ 
feociety  state,  that  a  definite  mixture  of  alcohol  and  water  is  as  invariable  in  its  value  as 
absolute  alcohol  can  be;  and  can  be  more  readily,  and  with  equal  accuracy,  identified 
by  that  only  quality  or  condition  to  which  recourse  can  be  had  in  practice,  namely 
specific  gravity     The  committee  further  proposed,  that  the  standard  spirit  be  that  which 
consisting  of  alcohol  and  water  alone,  shall  have  a  specific  gravity  of  0  92  at  the 
temperature  of  62°  Fahr.,  water  being  unity  at  the  sau.e  tempem7ure  •  or  in  other 
ZZX^l:'  ^'^  ''  '^  "^^^'  ToV  ^'  M  ''  -  ^^^^  ^-^^  '^  waTeVaT'ti:  ^Ime 

This  standard  is  rather  weaker  than  the  old  proof,  which  uas  J4,  or  0923  •  or  in  the 
proportion  of  nearly  M  gallon  of  the  present  prci)f  spirit  per^cent      The  Drowsed 

^1e  hu^nteZ'fT^  "fi  '"  ^^"^  '^^  ^^^^"^'°"  «^  ^^^^"^'^  5  ««t  «Pon  an'arbitraTy 
scaJe,  but  m  terms  of  specific  gravity  at  the  temperature  of  62°. 

the  slTTenl7h' nfT -r^^  J^'  construction  of  an  equation  table,  which  shall  indicate 
ine  same  strength  of  spirit  at  every  temperature.  Thus  in  standard  spirit  at  62°  the 
hydrometer  would  indicate  920,  which  in  this  table  would  give  prcK,f  Sit  If  that 
whtV'h"'  ""'"''^Y  \^^'  '^'  hydrometer  would  indicate^some htherC^berVbu 

rhould  stn?lfvT^'"'r  ^"  ^  T^l'  ^.^'-^  '^'  temperature  as  indicated  by  the  thermometer 
should  stiU  give  proof  or  standard  spirit  as  the  result. 

sm-rh'^bv^nf nnnV^""''*^^^'  ^"  ^^^'  ^"^  V^'  ^^^"  ^^^^^^  "°^  ^0  express  thequality  of  the 
ZlLrl  «"7.^""»^"  over  or  under  proof,  but  to  indicate  at  once  the  number  of  gallons  of 

tSus  instead  0?"'''""^^"'  or  equivalent  to,  100  gallons  of  the  spirit  under  examinat  on. 

uoder'  iroof  t  fnZ"!  ^■^''''  ^'^^M''  ^''^^'''^  '^  '''''^''  ^^3  ;  and  in  place  of  35-4 
unaer  proot,  to  insert  its  diflference  to  100,  or  646 

as^lo^W^fh".  h?if  r^-^-?f '"'^^  ***  recommend  a  second  table  to  be  constructed,  so 
bulk  of  1^0  tiw  «['/r'  f  7J  T^Hr'^  ^'  ^"y  temperature,  relative  to  a  standard 
anv  ciLn  t^rfnir  t  T-r'  ^"  ^^'  l^^^^  ^  'P'"""  '"^^^^  ^^^  diminished  in  volume,  at 
snfrifwhUT^f      '^'  V  P"  ^^"  •'  ^^'  ^''^^P'^'  ^^"l'^  ^^  expressed  by  99-3  ;   and  a 

^Wh^n  f         increased  at  any  given  temperature  0-7  per  cent ,  by  100-7. 
When  a  sample  of  spirit,    therefore,  has   been  examined   by  the  hydrometer  and 

erer^ureVn^^^^^^  ''t'  k'  "I"  ''''  f'^  '^"^  P^°P«^^'°»  ^'  ''^^^^'^  «Pi"t  at  tSeobJerved 
Sard   tP^nn/r  f  ""^  ^^^ /^hauge  of  bulk  of  such  spirit  from  what  it  would  be  at  the 

fsD  t??  of  8240  mn*  ?"''  ?'  i^'  temperature  of  51°,  and  with  an  indication 
&.si  fail  fn  d  ?'  ?*^^!lT!  °^„'^^  T"^  ""^^'-  examination  would  be  shown  by  the 
Sond  ti  J^  >^  ^^''f  ^°  ^^^*^  ?^^^T  «<^«^«»dard  spirit  of  that  temperature  ;  and  by  the 
6?  or  fn  l.«   t     '^'l^PPl"  iafo^^'^.  ^^^^'^^  «^ ^^«  '^"^^  sP^^t  would  become  100  at 

dnfv"^f^  '^  is  considered  that  neither  of  these  tables  can  alone  be  used  for  charging  the 
^o-^^i  inn  u^""  """^  f  P"^'"  '^^  ^^'^"^^  "l^^^^i^y  *>^  spirit  of  a  specific  gravity  of  092  at 
^nnifdio^"  .•  w^^?*""^'  or  weaker  spirit  at  temperat.ires  above  or  below  62°),  it  is 
Xi  on  f  l'fr^'^\l\^^^^  ^  ^^''^  y^^^''  combining  the  two  former,  and  expressing  this 
^n  riUn  inn  ^?i  f  'iP''''  "f  ^  inspection  it  shall  indicate  the  proportion  of  standard 
tK„r  tv  "^i  "f^^u  *^**  «nder  examination  in  its  then  present  state.  In  this  table 
the  quantities  should  be  set  down  m  the  actual  number  of  gallons  of  standard  spirit  at 
62°,  equivalent  to  100  of  the  spirit  under  examination;  and  the  column  of  quantities 
may  be  expressed  by  the  term  value,  as  it  in  reality  expresses  the  proportion  of  the  only 

«ci!}  \'"u''^"*'^  P'^'^^i-  ^'  *^^  ^»"  ^  ^^e  only  table  absolutely  necessary  to  be 
nsed  with  the  instrument  for  the  purposes  of  the  excise,  it  may,  perhaps,  be  Uiought 
unnecessarj  to  print  the  former  two.  ^  '       "*"«sui 


♦ 


i 


f  \    1 


ALCOHOL. 


28 


The  following  specimen  table  has  been  given  by  the  committee : 


Temperature  45«.                      | 

remperature  7i 

.«. 

Indication.* 

Strength. 

Value.        1    Indication. 

Strength. 

Valae. 

9074 

114-5 

8941 

114-5 

7 

114-3 

4 

114-3 

9 

114-2 

5 

114  2 

81 

114-0 

8 

114-0 

3 

113-9 

9 

113-9 

5 

113-7 

52 

113-7 

6 

113  6 

3 

113 '6 

9 

113-4 

6 

113-4 

90 

113-3 

7 

113-3 

3 

113-1 

9 

113-1 

_ 

The  mixture  of  alcohol  and  water,  taken  as  spirit  in  Mr.  Gilpm's  tables,  is  that  of 
which  the  specific  gravity  is  0-825  at  60°  Fahr.,  water  being  unity  at  the  sSne  temp^. 
ature.  The  specific  gravity  of  water  at  60°  being  1000,  at  62°  it  is  99,981.  Hence  in 
order  to  compare  the  specific  gravities  given  by  Mr.  Gilpin  with  those  which  would  re- 

mtt t'Lis:d'ryt9!9ir''  """'"" "'  '^  ^'  ''^''' ""'  ""^*^'  ^"^  "^^  ''"^'^  ^^-^^» 

Table  of  the  Specific  Gravities  of  different  Mixtures,  by  Weight,  of  Alcohol  and  Water. 
nue^^S  kite^'"^^''*^"'^'  constructed  by  Mr.  GUpin,  for  the  use  of  the  British  Reve^ 


I- 


Deg. 
30 
35 
40 
4$ 
50 
55 
60 
65 
70 
75 
80 
85 
90 
95 
10<) 


Pure 
Alcohol 


100 
Alcohol 

5 
Water. 


)-838d6 
•83672 
•83445 
•83214 
•82977 
•82736 
•82500 
•82262 
•82023 
•81780 
•81530 
•81291 
•81044 
■80794 
•80548 


0^84995 
•84769 
•84539 
•84310 
•84076 
•83834 
•83599 
•83362 
•83124 
•82878 
•82631 
•82396 
•82150 
•81900 
•81657 


100 

Alcohol 

10 


100 

Alcohol 

15 


Water.  Water 


0-85957 
•85729 
•85507 
■85277 
•85042 
84802 
84568 
84334 
84092 
83851 
83603 
83371 
83126 
82877 
82639 


100 
Alcohol 

20 
Water, 


Tenperattire, 
Falir. 


85 
40 
45 
90 
53 
60 
65 
70 
75 
80 
85 
90 
95 
100 


100 

Alcohol 

55 


0-86825 
•86587 
•86361 
•86131 
•85902 
•83664 
•85430 
•85193 
•84951 
•84710 
•84467 
•84343 
•84001 
•83753 
•83513 


0^87585 
•87357 

•87184 
•86905 
•86676 
•86441 
•86208 
•85976 
•85736 
•85496 
•85248 
•85036 
•84797 
•84550 
•84038 


100 
Alcohol 

25 
Water. 


100 

Alcohol 

60 


Water.  Water 


0-91449 
•91241 
•91020 
•90812 
•90596 
•90367 
•90144 
•89920 
•89695 
•89464 
•89225 
•89043 
•88817 
•88588 
83571 


0-91847 
•91640 
•91428 
91211 
•90997 
•90768 
•90545 
•90328 
•90104 
-89872 
•89639 
•89460 
•89230 
•89003 
887691 


0-88282 
■88059 
•87838 
87613 
87384 
87150 
66918 
86686 
86451 
86212 
85966 
85757 
85518 
85272 
85031 


100 
Alcohol 

30 
Water. 


0-88921 
•88701 
•88481 
•88^255 
•68030 
•87796 
•87569 
•87337 
•87105 
•86864 
•86622 
•86411 
•86172 
•85928 
•85688 


100 
Alcohol 

35 
Water 


0-89511 
-89294 
•89073 
•88849 
•88626 
•88393 
•88169 
•67938 
•87705 
•87466 
•87228 
•87021 
•86787 
•86542 
•86302 


100 
Alcohol 

65 
Water. 


0^92217 
•92009 
•91799 
•91584 
•91370 
•91144 
90927 
•90707 
-90464 
•90252 
•90021 
•89843 
•89617 
•89390 
•89158 


100 
Alcohol 

70 
Water. 


0-92563 
92355 
92151 
91937 
91723 
91502 
91287 
91066 
90847 
90617 
90385 
90209 


100 
Alcohol 

40 
Water 


1-90054 
•89839 
•89617 
•89396 

•89174 
•88945 
•887^20 
•88490 
•88254 
•88018 
•87776 
•67590 
87360 
•57114 
•86879 


100 

Alcohol 

45 
Water. 


0^90558 
90345 
90127 
89909 
89684 
89458 
89232 
89006 
88773 
68538 
88301 
881 -20 
67889 
87654 
87421 


100 
Alcohol 

75 
Water. 


100         100 

Alcohol!  Alcohol 

80  85 


Water. 


89763 
89536 


0-92889 
•92680 
•92476 
•92204 
•92051 
•91837 
•91622 
•91400 
-91181 
■90952 
•90723 
•90558 
90342 
90119 
89889 


093191 
•92986 
•92783 
•92570 
•92358 
•92145 
•91933 
•91715 
•91493 
•91270 
•91046 
•90882 
•90688 
•90443 
•90215, 


0-93474 
•93274 
•93072 
•92859 
•92647 
•92436 
•92^225 
•92010 
•91793 
•91569 
•91340 
•91186 
•90967 
•90747 
•905221 


100 

Alcohol 

90 


100 
Alcohol 

50 
Water. 


)91023 
-90811 
-90596 
•90380 
•901 1)0 
-89933 
-89707 
•89479 
•89252 
•89018 
■88781 
-88609 
•88376 
•88146 
•87915 


0-93741 
-93541 
•93341 
-93131 
•92919 
•92707 
•92499 
•92283 
•92069 
•91849 
■91622 
•91465 
91248 
91029 
90805 


100 

Alcohol 

95 


Water.  Water.   Water 


0-93991 

•93790 

•93592 

-9338-2 

-93177 

•92963 

•92758 

•92546 

•9-2333 

•92111 

•91891 

•91729 

•91511 

•91290 

•91066 


100 
Alcohol 

100 
Water 


0-94222 
•940-25 
•9.3827 
•93621 
•93419 
-93208 
-93002 
■92794 
■92580 
92364 
92142 
91969 
91751 
91531 
91310 


•By  specific  gravity. 


I 


I 


24 


ALCOHOL. 
Table  of  the  Specific  Gravities  of  different  Mixtures,  &c.  (amtinued). 


ature, 
r. 

95 

90 

85 

80 

75 

70 

65 

60 

55 

50 

I« 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

1^ 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

^ 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Deg. 

30 

0-94447 

094675 

0-94920 

0-95173 

095429 

095681 

0-95944 

0-96209 

096470 

096710 

35 

•94249 

•94484     -94734 

•94988 

•95246 

•95502 

•95772 

•96048 

•96315 

•96579 

40 

•94058 

•94295     ^94547 

•94802 

•95060 

•95328 

•95602 

•95879 

•96159 

•96434 

45 

•93860 

•94096 

•94348 

•94605 

•94871 

•95143 

•95423 

-95703 

•95993 

96180 

50 

•93658 

•93897 

•94149 

■94414 

•W663 

•94958 

•95243 

•95534 

•95831 

•90126 

55 

•93452 

•93696 

•93948 

•94213 

•94486 

•94767 

•95057 

•95357 

•95662 

•95966 

60 

•93247 

'93493 

•93749 

•94018 

•&4296 

•94579 

•94876 

•95181 

95493 

■95804 

65 

•93040 

•93285 

•93546 

•93822 

■94099 

•94388 

•94689 

•95000 

•95318 

•95635 

70 

•92628 

•93076 

•93337 

•93616 

•93898 

•94193 

•94500 

•94813 

95139 

•95469 

75 

•92613 

•92865 

•93132 

•93413 

•93695 

•93989 

•94301 

•94623      94957 

■95292 

80 

■92393 

•92646 

■92917 

■93201 

•93488 

•93785 

•94102 

-94431     -94768 

•95111 

45 

40 

35 

30 

25 

20 

15 

10 

5 

Temperatare, 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Alcohol 

Falif. 

100 

100 

100 

100 

100 

100 

100 

100 

100 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Water. 

Degrees. 

30 

0-96967 

0^97200 

0-97418 

097635 

097860 

098108 

0-98412 

0^98804 

099334 

35 

•96840 

•97086 

•97319 

•97556 

•97801 

•98076 

•98397 

•98804 

•99344 

40 

•96706 

•96967 

•97220 

•97472 

•97737 

•98033 

•98373 

•98795 

•99345 

45 

•96563 

•96840 

•97110 

•97384 

•97666 

•97980 

•98338 

•98774 

•99338 

SO 

•96420 

•96708 

•96995 

•97284 

•97589 

•97920 

•99293 

•98745 

•99316 

S5 

•96272 

•96575 

•96877 

•97181 

•97500 

•97847 

•98239 

•98702 

•99284 

60 

•96122 

•96437 

•96752 

•97074 

•97410 

•97771 

•98176 

•96654 

•99244  j 

OS 

•95962 

•96288 

•96620 

•96959 

•97309 

•97688 

•98106 

•98594 

•99194 i 

70 

•95802 

•96143      96484 

•96836 

•97203 

•97596 

•98028 

•98527 

•991341 

75 

•95638 

•95987     96344 

•96708 

•97086 

•97495 

•97943 

•98454 

•99066' 

80                -954671    958261  -961921    965681 

•96963 

•97385 

•97845 

-98367     -96991  j 

Experiments  were  made,  by  direction  of  the  committee,  to  verify  Gilpin's  tables, 
which  showed  that  the  error  introduced  in  ascertaining  the  strength  of  spirits  by  tables 
founded  on  Gilpin's  numbers  must  be  quite  insensible  in  the  practice  of  the  revenue. 
The  discrepancies  thus  detected,  on  a  mixture  of  a  given  strength,  did  not  amount  in  any 
one  instance  to  unity  in  the  fourth  place  of  decimals.  From  a  careful  inspection  of  such 
documents  the  committee  are  of  opinion,  that  Gilpin's  tables  possess  a  desree  of  accuracy 
fax  surpassing  what  could  be  expected,  and  sufficiently  perfect  fur  all  practical  or  sden- 
tinc  purposes. 

The  foUowing  table  is  given  by  Mr.  Lubbock,  for  converting  the  apparent  specific 
gravity,  or  indication,  into  true  specific  gravity. 


B 
O 

•*I 

m 
u 

a 

—                             Temperature.                             -h 

Indication. 

30° 

32° 

370 

420 

47« 

529 

570 

62° 

67«» 

72° 

77° 

80° 

•82 
•83 
■84 
•85 
•86 
•87 
•88 
•99 
•90 
•91 
•92 
•93 
•94 
•95 
•96 
•97 
•98 
•09 
i'lOO 

•00083 
•00084 
•00085 
•00086 
■00087 
•00088 
•00089 
•00090 
•00091 
•00092 
•00093 
•00094 
00095 
O0096 
■00097 
•00098 
•00099 
•00100 
•00101 

•00078 
■00079 
•00060 
•00081 
•00082 
•00083 
•00064 
•00085 
■00085 
•00086 
■00087 
•00088 
■00089 
■00090 
■00091 
■00092 
■00093 
•00094 
•00095 

•00065 
-00066 
-00066 
•00067 

00068 

00069 
•00070 
-00070 
•00071 
•00072 
■00073 

00073 
•00074 
-00075 

00076 
•00077 
-00077 
•00078 
•00079 

•00052 
00052 
00053 
•00054 
•00054 
■00055 
•00055 
■00055 
■00056 
-00057 
•00058 
•00059 
•00059 
-00060 
•00000 
•00061 
•00062 
■00062 
•00063 

■00039 
■00039 
■00039 
•00040 

00040 
•00041 
•00041 
•00042 
•00042 

00043 
•00043 
■00044 
■00044 
•00045 
•00045 
•00046 
•00046 
•00047 
•00047 

•00025 
•000-26 
•00026 
•00026 
•000-27 
•00027 
•00027 
•00028 
•00028 
•00028 
00029 
•00029 
•00029 
•00029 
•00030 
•00«30 
•00030 
•00031 
•00031 

•00012 
•00012 

00013 
•00013 
•00013 
•00013 
■00013 
•00013 
•O0OI4 
■00014 

00014 
•00014 
■00014 
•00014 
•00014 
•00015 
•00015 

00015 
•00015 

■00011 
•00012 
■00012 
■00012 
•00012 
-00012 
-00012 

00012 
■00013 
-00013 

00013 
-00013 
•00013 
•00013 
•00013 
•00014 
•00014 
•00014 

•00024 
•00024 
00024 
•00025 
•00025 
•000-25 
•00026 
00026 
00026 
•00020 
•00027 
•00027 
■000-27 
■00028 
■00028 
■00028 
00028 
•00029 

00035 

00036 

00036 

•00037 

■00037 

00037 

00038 

-00038 

•00039 

•00039 

•00040 

00040 

■00040 

■00041 

•00041 

•00042 

■00042 

•00043 

•00042 
00042 
00043 

•00043 

■00044 
00044 
00045 

•00045 
00046 

■00046 
00047 

•00047 

•00048 
00048 
()0049 

■00049 
00050 

■00050 

•89 
•83 
•84 

85 

•8e 

87 

•68 

«9 

90 

•91 

•92 

-93 

•94 

•95 

•96 

•97 

•96 

•99 

100 

ALCOHOL. 


25 


I 


i 


Fig,  5, 


6 


The  hydrometer  constructed,  under  the  directions  of  the  Commissioners  of  Excise,  by 
A  n^*  ****  *  ^^^^  °^  ^  inches  in  length  divided  into  100  parts, 
and  9  weights.     It  has  thus  a  lange  of  900  divisions,  and  expresses 
specific  gravities  at  the  temperature  of  62°  Fahr.     In  order  to  render 
this  mstrument  so  accurate  a  measurer  of  the  specific  gravity,  at  the 
standard  tempei:ature,  as  to  involve  no  error  of  an  appreciable  amount, 
Mr.  Bate  has  constructed  the  weights  (which  in  this  instrument  are  im- 
mersed m  the  fluid  of  difl'erent  specific  gravities)  so  that  each  succes- 
sive weight  should  have  an  increase  of  bulk  over  the  preceding  weight 
equal  to  that  part  of  the  stem  occupied  by  the  scale,  and  an  increase 
of  weight  sufficient  to  take  the  whole  of  the  scale,  and  no  more,  down 
to  the  liquid.     This  arrangement  requires  great  accuracy  of  workman- 
ship, and  enhances  the  price  of  the  instrument.    But  it  allows  of  in- 
creased strength  in  the  ball,  where  it  is  very  much  required,  and  it 
gives,  upon  inspection  only,  the  indication  (apparent  specific  gravity) 
by  which  the  general  table  is  to  be  examined  and  the  result  ascertained. 
J  ig.  5  represents  this  instrument  and  two  of  its  nine  ballast  weights. 
It  comprehends  all  specific  gravities  between  820  and  1000.    It  indi- 

ItV  ^'elSVi""  ^T"y  "^'^^  ^^°^^  P^^^<^^  accuracy  at  the  temper- 
ature  of  ^  Fahr. ;  but  it  does  not  exclude  other  instruments  from 
being  used  in  conjunction  with  tables.  The  latter  are,  in  fact,  inde- 
pendent of  the  instrument,  and  may  be  used  with  gravimeters,  or 
any  instrument  afibrding  indications  by  specific  gravity  at  a  civen 
temperature.    See  Spiarrs.  ° 

The  commercial  value  of  spirituous  liquors  being  much  lower  in 
!•  ranee  than  m  England,  a  less  sensible  instrument  becomes  sufficient 
l^wi  I'^J!"^^?^  ^^*'  country.     Baume's  and  Cartiers  hydrometers, 
with  short  arbitrary  scales,  are  very  much  employed,  but  they  have  been  lately  suner- 
seded  by  an  ingenious  and  ready  instrument  contrived  by  M.  Gay  Lussac    and  cE 
by  him  an  alcoometre      He  takes  for  the  term  of  comparLon  pure  alcohol  by  volume 
at  the  temperature  of  15°  Cent.,  and  represents  the  strength  of  1^^100  c^/r« 
or  by  unity      Consequently,  the  strength  of  a  spirituous  liquid  is  the  n umber Tf  Ten 
nmes  in  volume  of  pure  alcohol  which  that  liquid  contains  at  the  tempemmre  of  Is' 

tem~:  onTcei/'  '"C  l"''  ^  Ti"^"  hydrometer,  and  is  gr'aduat Ji  for  ic 
lemperature  ol  15  Cent.  Its  scale  is  divided  into  100  parts  or  degrees  each  of  which 
denotes  a  centmie  of  alcohol;  the  division  0  at  the  bottom  of  the  s  m  coi^eslnds 
o  pure  water,  and  the  division  100  at  its  top,  to  pure  alcohol  When  Tmme7sed  iS  a 
^«rr'r  •'*"°'^  *'  ^^°  ^^"i-  (^^  ^^^'-^  '''  announces  its  strength  Z^cUv  For 
U  rd^at^ef  thatC^t^e^^^^^^  temperature  of  15°  Cent,  it  sinkf  to  thTdfvis'ion  5o' 

of  Dure  afoohol  Tn  ^  of  this  hquor  is  50  per  cent.,  or  that  it  contains  50  centimes 
?7  wt  1  V   ^^ ''"f  new  British  proof  spirit,  it  would  sink  to  nearly  57  indicat^^ 

57  by  volume  of  pure  alcohol,  allowing  for  condensation,  or  60  by  weY^Jht     TtabL^f 

iTquors  »"  Th7TJZ  T'rT'  "5't '^  ^""^  "  ^^^'«  of  rea/streS  oflpTrhuous 
i^cl'nt  Ih  t?  «  ^.1'''^^  ''^^T!'.  °^  ^^'^  ^^^^^  *=°ntains  the  temperatures,  from  0»  to 
Lhl.  li';.  ^^•'^  ^''•"'^^?^^^  ^'""^  ^^^  indications  of  the  alcoLetre.     InXs^ne 

table  we  have  most  ingeniously  inserted  a  correction  for  the  volume  of  the  snfrk^  wW 

t  Tr^::::re'TJ'7  r  ^r-  ''.^^  ^^^^  ''''  mref oTgalt,  SLIi'lt 
reals3thri5oL^/r        ,KP'"*"'''i'  ^'^"°i  "^^^^^  ^PP"^"t  strength  is  44o  ;  its 

KlVlSot'  ^"^SL'nlr -^"^  orVlonsf  whicri[  r^ured  'S  ^le^l^'''^^. 
r^h  ^L       I  ;  ^  number  is  inscribed  in  smaller  characters  in  the  same  souare  cell 

w.„ld  have,  when  mfasired  a,  «.e  i^m^nl^'^t^i^  i'[Z:fj  X:^";:  S' 

m9l^To-l9l!97T4u'^''""^  "  ""  temperature  of  2°,  will  be.  therefore.- 
.iiMy'nSJ?  "'"''"^  '^"''"''  *"'  «*''"»»«'.  «  e«M  richm,,  of  ,pirU  in  alcolud,  or 
IS^Cent  '^?.„°'„"„tT''lf  ^"'l^^?-  *^  P'-^-'««»?.  >>«  «'  "  higher  temperature  than 

vojume  win  be  993  litres;  it  is  inscribed  directly  below  49c-3,  the  real  strength.     We 


I 


I 


mm 


mm 


mmm- 


ae 


ALCOHOL. 


diall  therefore  have  of  pure  alcohol,  contained  in  the  1000  litres  of  spirits,  measuied  at 
the  temperature  of  25^  or  their  richness,  993  lit.  X  0-493  =  489  lit.  55.      "^^""^  *' 


ALCOHOL. 
Alcometrical  Table  of  real  Strength,  by  M.  Gay  Lussac  (con/tntted). 


ar 


lii 


Alcometrical  Table  of  real  Strength,  by  M.  Gay  Lussac. 

- 

Temperature 
C. 

•       31c 

32c 

33c 

34c 

35e 

36c 

37c 

38c 

39c 

40c 

Deg. 
10 

11 

12 

33  0 

1002 

34 

1002 

35 

1003 

36 

1003 

37 

1003 

38 
1003 

39 
1003 

40 
1003 

41 
1003 

42 

1003 

32-6 

1002 

33-6 

1002 

34-6 

1002 

35-6 

1002 

36-6 

1002 

37-6 
1002 

38-6 
1002 

39-6 

1003 

40-6 
1003 

41  6 

1003 

32-2 
1001 

33-2 

1001 

34-2 

1002 

33-8 

1001 

35-2 

1002 

36-2 

1002 

37-2 
1002 

38-2 
1002 

39-2 
1002 

40-2 
1002 

41  -2 

1002 

40-8 
1001 

IS 

31-8 
1001 

32-8 

1001 

34-8 

1001 

* 

35-8 
1001 

36  S 
1001 

37-8 
1001 

38-8 
1001 

39-8 
100! 

14 

31-4 
1001 

32-4 
1001 

33-4 

1001 

33 

1000 

34-4 
1001 

34 

1000 

3oA 
1001 

36-4 
1001 

37-4 
1001 

38-4 
1001 

39-4 
1001 

39 

1000 

40-4 
1001 

16 
16 
17 
18 

19 
20 

31 

1000 

32 

1000 

35 

1000 

36 

1000 

37 
1000 

38 

1000 

46 
1000 

39-5 
999 

30-6 
1000 

30-2 
999 

31-6 
1000 

32-5 

999 

33-5 
999 

34-5 
999 

35-5 
999 

36-5 
999 

37-5 
999 

38-5 
999 

31-2 

999 

32  1 

999 

33  1 

999 

34  1 

999 

351 

999 

36  1 

999 

371 

999 

381 

999 

39-1 

999 

29-8 
999 

30-8 
999 

31-7 

998 

32-7 
998 

33-7 
998 

34-7 

998 

35-7 
998 

36-7 

998 

37-7 

998 

38-7 

998 

29-4 
998 

30-4 
998 

31-3 

998 

30-9 
997 

32-3 

998 

33-3 

998 

34-3 

998 

35-3 

998 

36-3 

998 

37-3 

997 

38-3 
997 

29 

998 

30 
998 

31-9 
997 

32-9 

997 

33-9 

997 

34-9 

997 

35-9 
997 

36-9 
997 

37-9 

997 

21 

28-6 
997 

29-6 
997 

30-6 

997 

31-5 

997 

32-5 

997 

33-5 

997 

34-5 

997 

996 

36-5 

996 

37-5 
996 

22 
23 
24 
25 

28-2 
997 

29-2 
997 

30  1 

996 

31    1 

996 

32-1 

996 

33  1 

996 

341 

996 

351 
996 

36  1 

996 

37  1 

996 

27-8 
996 

28-8 
996 

29-7 
996 

30-7 
996 

31-7 
996 

32-7 
996 

33-7 
996 

34-7 
095 

35-7 
995 

36-7 
995 

27-4 

996 

28-4 
996 

28 
995 

29-3 
995 

30-3 
995 

31-3 
995 

32-3 

995 

33  3 

995 

34-3 

995 

35-3 
995 

36-3 
994 

27 

995 

28  -9     29  -9 

995          995 

30-9 

095 

31-9 

994 

32-9 

994 

33-9 

994 

34  9 

994 

35-9 

994 

Teniperature. 
C. 

41c 

42c 

43c 

44r 

45c 

46c 

47c         48c 

49c 

50c 

11 
12 
13 
14 

43 

1003 

44 
1004 

45 

1004 

46 
1001 

46-9 
1004 

47-9 

1004 

48-9 
1004 

49-9 
1004 

50-9 
1004 

51-8 
1004 

42-6 
1003 

43-6 
1003 

44-6 

1003 

45-6 

1003 

46-6 

1003 

47-6 

1003 

48-6 
1003 

49-5 

1003 

50-5 
1003 

51-5 
1003 

42-2 
1002 

43-2 

44-2 
1003 

45-2 
1002 

46-2 
1003 

47-2 
1003 

48-2 
1002 

49-2 

1002 

60-2 
1002 

51-1 

1003 

41-8 
1001 

42-8 
1001 

42-4 
1001 

43-8 
1001 

44 -S 
1002 

45-8 
1002 

46-8 
1002 

47-8 
1002 

48-8 
1002 

49 -S 
1002 

60-8 
1002 

41-4 
1001 

43-4 
1001 

44-4 
1001 

45-4 
1001 

46-4 
1000 

47-4 
1001 

48-4 
1001 

49-4 
1001 

50-4 
1000 

50 
1000 

15 

41 

1000 

42 
1000 

43 

1000 

44 
1000 

45 

1000 

46 
1000 

47 
1000 

48 
1000 

49 
1000 

16 

40-6 
999 

41-6 
999     » 

42-6 
999 

43-6 

999 

44-6 
999 

45-6 
999 

4G'6 
999    1 

47-6 
099 

48-6 
099 

49-6 
999 

I 


Teniperatare 
C. 

•       41c 

4ac 

43c 

44r. 

45c 

46c 

47c 

48c 

49c 

50c 

Deg. 
17 

18 

19 

so 

SI 
82 
S3 
24 
25 

40-2 
999 

41-2 

999 

42-2 

999 

43-2 

998 

44-9 
998 

45-2 

998 

'     46-2     47  -2 

998         998 

48-2 
998 

49-2 

998 

39-8 
098 

40-8 
998 

41-8 
998 

42-8 
998 

43-8 
998 

44-9 
998 

45  -9     46  -9 

998         998 

47-9 

998 

48-9 
998 

39-4 
997 

40  4 
997 

41-4 
997 

42-5 

997 

43-5 

997 

44-5 
997 

45 -S 
99^ 

•     46-5 

997 

1 

47-5 

997 

48-5 
997 

39 

997 

40 
997 

41 

997 

40-6 
996 

42  1 

997 

43  1 

996 

441 

996 

451 
996 

46  1 

996 

47-2 
996 

48-2 
996 

38-6 

990 

39-6 
99G 

41  -7 

996 

42-7 
996 

43-7 

996 

44-8 
996 

45-8 
996 

46-8 
995 

47-8 
995 

38-2 

996 

39-2 

095 

40-2 
995 

41-3 

995 

42-3 

995 

43-3 

995 

44-3 
995 

45  3 

995 

46-4 
995 

47-4 
995 

37-8 
995 

38-8 

995 

39-8 
995 

40-9 
994 

41  -9 

994 

42-9 
994 

43-9 
994 

44-9 
994 

46 
994 

47 
994 

37-4 

994 

38-4 
994 

39-4 
994 

40-5 
994 

41-5 

994 

42-5 
994 

43-6 

994 

44-6 
994 

45-6 
993 

46-6 

993 

37         38 

994          994 

39 
1     993 

401      42-1 

993          993 

42-2 
993 

43-2 

993 

44-2 
9i*j 

45-2 
993 

>6-3 

993 

Tempera  lure. 
C. 

51c 

52c. 

53c 

54c 

55c 

56c 

57c 

58c 

59c 
60-7 

1004 

60c 

Deg 
10 

11 

12 

13 
14 
15 
16 
17 
18 
19 

52-8 
1001 

53-8 
1004 

54-8 
1004 

55-8 

1004 

56-8 
1004 

57-8 
1004 

58-8 

1004 

59-7 
1004 

61-7 

1004 

62-5 
1003 

53-5 

1003 

54-4 

1003 

55-4 
1003 

56-4 

1003 

57-4 
1003 

58-4 
1003 

59-4 
1003 

60-4 
1003 

61-4 
1003 

52  1 

1003 

53  1 

1002 

54-1 

1002 

55 

1002 

56 

1002 

57 

1003 

58 

1002 

59 
1002 

60 

1002 

61 

1002 

51.8 

1002 

52-7 

1O02 

53-7 

1002 

54-7 

1002 

65.7 
1003 

56-7 
1002 

57-7 
1002 

68-7 
1003 

59-7 
1002 

60-7 

1002 

51-4 

1001 

52-3 

1001 

53-3 

1001 

54-3 
1001 

55  3 
1001 

56-3 
1001 

57-3 
1001 

58-3 
1001 

59-3 
1001 

60-3 
1001 

51 

1000 

52 
1000 

53 

1000 

54 
1000 

55 

1000 

56 

1000 

57 

1000 

58 

1000 

59 

1000 

60 

1000 

50-6 

999 

51-6 

999 

52-6 

999 

53-6 
999 

54-6 
999 

55-6 
999 

56-6 
999 

57-6 
999 

58-6 
999 

59-6 

999 

50-3 

998 

51-3 

998 

52-3 
998 

53-3 

998 

54-3 

998 

55-3 
998 

56-3 
998 

55-9 

998 

57-3 
998 

58-3 

998 

59-3 

998 

49-9 

998 

50-9 

998 

51-9 

998 

52-9 
998 

53-9 

998 

54-9 

998 

56-9 
997 

57-9 
997 

58-9 
997 

49-5 
997 

50-6 
997 

51-6 
997 

52-6 
997 

63-6 
997 

54-6 
997 

55-6 
997 

56-6 
997 

57-6 
997 

58-6 
997 

20 

49-2 
996 

50-2 
996 

51-2 
996 

52-2 
996 

53-2 
996 

54-2 
996 

55-2 
996 

54-9 
995 

56-2 
996 

57-2 
996 

58-2 
996 

21 

48-8 
995 

49-8 
995 

60-8 
995 

51-8 
995 

52-9 
995 

53-9 
995 

55-9 
995 

56-9 
995 

57-9 
995 

22 

48-4 
995 

49-4 
995 

50-4 
995 

51-4 
994 

62-5 
994 

53-5 
994 

54-5 
994 

55*5 
994 

56-5 
994 

57-5 
994 

23 

48 
994 

49-1 
994 

50-1 
994 

51-1 

994 

52-1 
994 

53  1 
994 

54-1 
994 

551 
993 

56  1 
993 

57  1 
993 

S4 

47-6 
993 

48-7 
993 

49-7 
993 

50-7 
993 

51-8 
993 

52-8 
993 

53-8 
993 

54-8 
993 

55-8 
993 

56-8 
992 

S5 

47-3 

48-3 
993 

49-3 
993 

50-3 
992 

51-4 
992 

52-4 

992 

53-4 
992 

54-4 
993 

5.'>  5 
092 

56-5 
993    1 

7 


28 


ALCOHOL. 


f 


Alcometrical  Table  of  real  Strength,  by  M.  Gay  Lussac  (continu&T^ 

1. 

Temperature 
C. 

61c 

62c 

63c 

64c 

65c 

66c 

67c 

68c 

69c 

70c 

Deg. 
10 

11 

IS 

13 

14 

1» 

16 

17 

18 

19 

SO 

21 

22 

23 

24 

25 

62-7 
1004 

63-7 
1004 

64-7 

1004 

65-7 
1004 

66-7 
1004 

67-6 
1004 

68-6 
1004 

69-6 

1004 

70-6 

1004 

71-6 
1004 

62-4 
1003 

63-4 
1003 

64-4 
1003 

65-4 
1003 

66-4 
1003 

67-3 
1003 

68-3 
1003 

69-3 

1004 

70-3 
1004 

71-3 

1004 

62 

1003 

63 

1003 

64 

1003 

65 
1003 

66 
1002 

67 
1002 

68 

1003 

69 

1003 

70 
1003 

71 
1003 

61.7 
1002 

62-7 
1003 

63-7 
1002 

64-7 
1002 

65  7 
1002 

66-7 

1002 

67-7 

1002 

68-7 

1002 

69-6 
1002 

70-6 

1002 

61-3 

1001 

62-3 
1001 

63-3 

1001 

64-3 
1001 

65  3 

1001 

66 
1000 

66-3 

1001 

67-3 
1001 

68-3 
1001 

69-3 
1001 

70-3 
1001 

61 

1000 

62 
1000 

63 
1000 

64 

1000 

66 

1000 

67 

1000 

68 
1000 

69 
1000 

70 
1000 

60-6 
999 

61-7 
999 

62-7 

999 

63-7 
999 

64-7 
999 

65-7 
999 

66-7 

999 

67-7 
999 

68-7 
999 

69-7 
999 

60-3 
998 

61-3 

998 

62-3 

998 

63-3 

998 

64-3 

998 

65-3 

998 

66-3 

998 

67-3 

998 

68-3 

998 

69-3 

998 

59-9 
997 

61 
997 

62 

997 

63 

997 

64 
997 

65 

997 

66 

997 

67 
997 

68 
997 

69 
997 

59-6 

997 

60-6 

997 

61-6 

997 

62-7 

997 

63-7 
997 

64-7 
997 

65-7 
997 

66-7 
997 

67-7 

990 

68-7 
£96 

59-2 
996 

60-3 
996 

61-3 

996 

62-3 
996 

63-3 

996 

64-3 
996 

65-4 
996 

66-4 
996 

67-4 
996 

68-4 
996 

58-9 
995 

59-9 
995 

61 
995 

62 

995 

63 

995 

64 

995 

65 

995 

66 

995 

67 
995 

681 
995 

58-5 
994 

59-5 
994 

60-6 
994 

61-6 
994 

62-7 
994 

63-7 

994 

64-7 
994 

65-7 
994 

66-7 
994 

67-8 
994 

58-1 
993 

59-2 
993 

60-2 
993 

61  -3 
993 

62-3 
993 

63-3 
993 

64-3 
993 

65-4 

993 

66-4 
993 

67-4 
993 

57-8 
992 

58-9 
992 

69-9 
992 

61 

992 

62 
992 

63 

992 

64 

992 

65 
992 

66 

992 

67-1 
992 

57-5 
992 

58-5 

992 

59-5 

«192 

60-6 

99) 

61-6 

991 

62-6 

9QI 

63-7 

991 

64-7 
991 

65-7 
991 

66-7 
991 

'Temperature. 
C. 

71c 

72c 

73e 

74c 

75c 

76c 

77-5 
1005 

77c 

78c 

79c 

80c 

11 
IS 
13 
14 

72-6 

1004 

73-5 
1004 

74-5 
1005 

75-5 
1005 

76-5 
1005 

78-5 
1005 

79-5 

1005 

80-5 
1005 

81-5 

1005 

72  3 

1004 

73-2 
1004 

74-2 

1004 

75-2 

1004 

76-2 

1004 

77-2 
1004 

78-2 
1004 

79-2 
1004 

SO -2 
1004 

81-2 
1004 

72 

1003 

72-9 
1003 

73-9 
1003 

74-9 
1003 

75-9 
1003 

76-9 

1003 

77-9 
1003 

78-9 

1003 

79-9 
1003 

80-9 
1003 

71-6 
1002 

72-6 
1002 

73-6 
1002 

74-6 
1003 

75-6 
1002 

76-6 
1002 

77-6 
1002 

78-6 
1002 

79-6 
1002 

80-6 
1002 

71-3 
1001 

72-3 

1001 

73-3 

1001 

74-3 
1001 

75-3 
1001 

76-3 
1001 

77-3     78-3 
1001        1001 

79 '3 
1001 

80-3 
100^ 

15 

71 
1000 

72 

1000 

73 

1000 

74 

1000 

75 
1000 

76 
1000 

77 
1000 

78 
1000 

79 

1000 

80 
1000 

16 

70-7 
999 

71-7 
999 

72-7 
999 

73-7 
S99 

74-7 
999 

75-7 
999 

76-7 
999 

77-7 
999 

78-7 
999 

79-7 
999 

17 

70-3 
998 

71-3 
998 

72-3 

998 

73-3 

998 

74-3 

996 

75-4 

998     1 

76-4 
998 

77-4 
998 

78-4 
998 

794 

908 

ALCOHOL. 
Alcometrical  Table  of  real  Strength,  by  M.  Gay  Lnssac  (amtinued). 


29 


Tssperatore 
C. 

71c 

72c 

73c 

74c 

75c 

76c 

77c 

78c 

79c 

80c 

19 

90 
91 
S2 
S3 

24 
25 

70 

997 

71 

997 

72 

997 

73 

997 

74 
997 

75  1 

997 

76  1 

997 

771 

997 

78-1 
997 

79-1 

997 

69-7 
996 

70-7 
996 

71-7 
996 

72-7 
996 

73-7 

996 

74-7 
996 

75-8 
996 

76-8 
996 

77-8 
996 

78-8 
996 

69-4 
996 

70-4 
996 

71-4 
995 

72-4 
995 

73-4 
995 

74-4 
995 

75-5 
995 

76-5 
995 

77-5 
995 

78-5 
995 

691 

995 

70-1 
995 

71  1 

995 

72  1 

994 

73  1 

994 

74  1 

994 

75-2 
994 

76-2 

994 

77-2 
994 

78^ 
994 

68-8 
994 

69-8 
994 

70-8 
994 

71-8 
994 

72-8 
993 

73-8 
993 

74-8 
993 

75-9 
993 

76-9 
993 

77-9 
993 

68-4 
993 

69-4 

993 

70-5 
993 

71-5 
993 

72-5 

992 

73-5 
992 

74-5 
992 

75-5 
993 

76-6 
992 

77-6 

1    992 

68-1 
992 

67-8 
991 

69-1 

992 

70-1 
992 

71-2 
992 

72-2 
992 

73-2 
992 

74-2 
992 

75-2 
991 

76-3 
991 

77-3 

991 

68-8 
991 

69-8 
991 

70-8 
991 

71  -8 
991 

72-8 
991 

73-9 
991 

74-9 
991 

76 

991 

77 
991 

Temperature. 
C. 

81c 

82c 

83c 

84c 

85c 

86-4 
1005 

86c 

87c 

88c 

89c 

90e 

Deg. 
10 

11 

12 

13 

14 

15 

16 

17 

18 

19 
20 
21 
22 
23 
34 

82-4 
1005 

83-4 
1005 

84-4 
1005 

85-4 
1005 

87-4 
1005 

88-3 
1005 

89-3 

1005 

90-2 
1005 

91-2 
1005 

82-2 
1004 

83  1 

1004 

84-1 
1004 

85-1 
1004 

861 

1004 

87-1 

1004 

86-8 
1003 

88 
1004 

89 

1004 

90 

1004 

91 

1004 

81-9 
1003 

82-9 
1003 

83-9 
1003 

84-8 
1003 

85-8 
1003 

87-8 
1003 

88-7 
1003 

89-7 
1003 

90-7 
1003 

81.6 

1002 

82-6 
1002 

83-6 
1002 

84-6 
1003 

85 -5 
1002 

86-5 
1002 

87-5 
1003 

88-5 
1003 

89-5 
1002 

90-5 
lOOS 

81-3 

1001 

82-3 

1001 

83-3 
1001 

84-3 

1001 

85-3 
1001 

86-3 
1001 

87-3 
1001 

88-2 
1001 

89-2 
1001 

90-2 
1001 

81 
1000 

82 
1000 

83 

1000 

84 
1000 

85 
1000 

86 
1000 

87 
1000 

88 
1000 

89 
1000 

90 

1000 

80-7 
999 

81-7 
999 

82-7 
999 

83-7 
999 

84-7 
999 

85-7 
999 

86-7 
999 

87-7 
999 

88-7 
999 

89-7 
999 

80-4 
998 

81-4 
998 

82-4 
998 

83-4 
998 

84-4 
998 

85-4 
998 

86-4 
996 

87-4 
998 

88-4 
998 

89-5 
998 

801 

997 

81-1 
997 

82  1 

997 

83-1 
997 

84-1 
997 

85-2 
997 

86-2 
997 

87-2 
997 

88-2 
997 

89-2 
997 

79-8 
996 

80-8 
996 

81-9 
996 

82-9 
996 

83-9 

996 

84-9 
996 

85-9 
996 

86-9 
996 

87 -9 

996 

88-9 
996 

79-5 
995 

80-5 
995 

81-6 

995 

82-6 
995 

83-6 
995 

84-6 
995 

85-6 
995 

86-6 
995 

87-7 
995 

88-7 
995 

79-2 
994 

80-2 
994 

81-3 
994 

82-3 
994 

82 
993 

83-3 
994 

84-3 
994 

86-3 
994 

86-4 
994 

87-4 
994 

88-4 

994 

78-9 
993 

79-9 
993 

81 
093 

S3 
993 

84 
093 

85 
993 

861 

993 

87  1 
993 

88-2 
993 

78-6 
992 

79-6 
992 

80-7 
992 

81-7 
992 

82-7 
992 

83-8 
992 

84-8 
993 

85-8 
992 

86-8 
998 

87-9 
993 

78-3 
991 

79-3 
991 

80-4 
991 

81-4 
991 

82-4 
991 

83-5 
991 

84-5 
991 

85-5 
991 

86-5 
991 

87-6 
991 

95 

78 
091 

79 
991 

80-1 
990 

81-1 
990 

821 
990 

83-2 
990     i 

84-2 
990 

85-2 
990 

86-3 
990 

87-4 
000 

30 


ALCOHOL. 


I  consider  the  preceding  table,  which  I  have  extracted  from  the  longer  tables  of 
M.  Gajr  Liissac,  as  an  important  addition  to  the  resources  of  British  dealers  and  manu- 
facturmg  chemists.     With  the  aid  of  his  little  instrument,  which  may  be  got  for  a 
trifle  from  its  ingenious  maker,  M.  Collardeau,  Rue  Fauburg  St.  Martm  at  Paris,  or 
constructed  by  one  of  the  London  hydrometer  artists,  the  per  centage  of  real  alcohol, 
and  the  real  value  of  any  spirituous  liquor,  may  be  determined  to  sufficient  nicety  for 
most  purposes,  in  a  far  easier  manner  than  by  any  instruments  now  used  in  this  coun- 
try.    It  has  been  adopted  by  the  Swedish  government,  with  M.  Gay  Lussac's  tables. 
M.  Gay  Lussac's  table  gives,  by  inspection,  the  true  bulk  of  the  spii-its  as  corrected 
for  temperature ;  that  is  their  volume,  if  of  the  normal  temperature  of  15**  Cent.  {o9<* 
Fahr).     Now  this  is  important  infoi-mation ;  for,  if  a  person  buys  1000  gallons  of  spirits 
in  hot  weather,  and  pays  for  them  exactly  according  to  their  strength  corrected  for 
temp^ature,  he  will  not  have  1000  gallons  when  the  weather  is  in  its  mean  state.  He 
may  lose,  in  this  way,  several  gallons,  without  being  aware  of  it  from  his  hydrometer. 
Sometimes,  after  moist  autumns,  when  damaged  grain  abounds,  the  alcohol  distilled 
from  its  fermented  wash  contains  a  peculiar  volatile  body.     "When  we  apply  our  nose 
to  this  species  of  spirits  in  its  hot  state,  the  volatile  substance  dissolved  in  it  irritates 
the  eyes  and  nostrils ;  it  has  yerj  nearly  the  same  smell  as  an  alcoholic  solution  of 
cyanogen,  as  any  chemist  may  discover  by  standing  near  the  discharge  pipe  of  the 
refrigeratory  worm  of  a  raw-grain  whisky  still.   Such  spirits  intoxicate  more  strongly 
than  pure  spirits  of  the  same  strength,  and  excite,  in  many  persons,  even  temporary 
frenzy.     It  is  a  volatile  fatty  matter,  of  a  very  fetid  odor,  when  obtained  by  itself,  as 
I  have  procured  it  in  cold  weather  at  some  of  the  great  distilleries  in  Scotland.     It 
does  not  combine  with  bases.   At  the  end  of  a  few  months,  it  spontaneously  decomposes 
in  the  spirits  and  leaves  them  in  a  less  nauseous  and  noxious  state.     By  largely  dilut- 
ing the  spirits  with  water,  and  distilling  at  a  moderate  temperature,  the  greater  part 
of  this  oil  may  be  separated.    Part  of  it  comes  over  with  the  strongest  alcohol,  and 
part  with  the  latter  runnings,  which  are  called  by  the  distillers  strong  and  weak  feint*. 
The  intermediate  portion  is  purer  spirit   The  feints  are  always  more  or  less  opalescent, 
or  become  so  on  dilution  with  water,  and  then  throw  up  an  oily  pellicle  upon  their 
surface.     The  charcoals  of  light  wood,  such  as  pine  or  willow,  well  calcined,  and  in- 
fused in  sufficient  quantity  with  the  spirits  prior  to  rectification,  will  deprive  them  of 
the  greater  part  of  that  oily  contamination.     Animal  charcoal,  well  calcined,  has  also 
been  found  useful ;  but  it  must  be  macerated  for  some  time  with  the  empyreumatic 
spirits,  before  distillation.     Another  mode  of  separating  that  offensive  oil  is,  to  agitate 
the  impure  spirits  with  a  quantity  of  a  fat  oil,  such  as  olive  oil,  or  oil  of  almonds,  to 
decant  off  the  oil,  and  re-distil  the  spirits  with  a  little  water. 

Digestion  and  agitation  with  calcined  magnesia,  for  some  time,  followed  by  filtration 
and  distillation,  are  also  good  means  of  improving  the  flavor  of  alcohol  The  taste 
of  the  oil  of  grains  is  best  recognized  by  agitation  with  water,  whereby,  on  standing, 
the  diluted  spirit  throws  up  a  film  of  oil,  risible  by  reflected  light  If  the  spirit  be 
mixed  with  a  few  drops  of  nitrate  of  silver  and  exposed  for  some  time  to  sunshine,  the 
oil  will  react  upon  the  oxide  of  silver,  and  cause  a  brown  tinge ;  but  if  there  be  no  oil 
present,  the  spirits  will  remain  limpid.  If  one  part  of  hydrate  of  potash,  dissolved 
in  a  little  water,  be  mixed  with  160  parts  of  spirits,  and  if  the  mixture  be  well  shaken, 
then  slowly  evaporated  down  to  15  parts  and  mixed  with  15  parts  of  dilute  sulphuric 
acid  in  a  phial,  to  be  then  corked,  there  will  soon  exhale  from  the  mixture  a  peculiar 
offensive  odor,  characteristic  of  the  quality  and  origin  of  the  impure  spirit,  whether 
obtained  from  raw  grain,  from  malt,  from  potatoes,  rye,  arrack,  rum,  brandy,  <fec. 
This  excellent  process  may  be  used  also  for  testing  wines.  Lime  and  alkalis  always 
injure  the  flavor  of  ardent  spirits  of  all  kinds. 

Some  foreign  chemists  direct  empyreumatic  or  rank  spirits  to  be  rectified  with  the 
addition  of  chloride  of  lime.  I  have  tried  this  method  in  every  way,  and  on  a  con- 
siderable scale,  but  never  found  the  spirits  to  be  improved  by  it  lliey  were  rather 
deteriorated.    See  Brandy,  Distillation,  Fermentation,  Gin,  Rum,  and  Whisky. 

Anhydrous  or  absolute  alcohol,  when  swallowed,  acts  as  a  mortal  poison,  not  only 
by  its  peculiar  stimulus  on  the  nervous  system,  but  by  its  abstracting  the  aqueous 
particles  from  the  soft  tissue  of  the  stomacli,  with  which  it  comes  in  contact,  so  as  to 
destroy  its  organization. 

The  absence  of  water  in  alcohol  may  be  tested  by  sulphate  of  copper  calcined  to 
whiteness,  which  imparts  a  blue  tin;!:;e  to  the  liquid.  46  parts  of  absolute  alcohol 
contain  6  parts  of  hydrogen ;  and  hence,  by  being  burnt  in  a  tubulated  globular  re- 
ceiver connected  with  a  condensing  worm,  they  afford  54  parts  of  water.  If  the  spirit 
was  free  from  oil,  the  water  will  be  quite  pure,  as  the  carbonic  acid  flies  off. 

The  high  price  of  alcohol  in  this  country,  in  consequence  of  the  heavy  fiscal  duties, 
and  its  low  price  in  most  other  countries,  where  it  is  nearly  duty  free,  has  led  to  its 
contraband  importation  under  various  disguises.     Sometimes  it  is  introduced  under  the 


ALGAROVILLA. 


81 


I 


f 


i 


mask  of  oil  of  turpentine,  from  which  it  can  be  sufficiently  freed  by  rectification  for 
the  purpose  of  the  gin  manufacturers.  Sometimes  it  is  disguised  with  wood  naphtha, 
or  wood  vinegar;  from  the  latter  of  which  it  may  be  separated  by  distillation  in  a  water 
bath;  but  from  the  former  it  is  more  difficult  to  extricate  it,  as  alcohol  and  wood  spirit 
are  nearly  equally  volatile.  It  has  also  been  disguised  with  coal  naphtha;  but  from 
this  it  may  be  easily  separated  by  distillation,  on  account  of  the  great  difference  be- 
tween the  boiling  points  of  the  two  liquids;  besides,  coal  naphtha  will  not  combine 
with  water,  as  alcohol  does. 

When  the  object  is  to  discover  whether  wood  spirit  contains  alcohol,  we  may  pro- 
ceed as  follows: — Add  to  the  suspected  liquid  a  little  nitric  acid,  of  specific  gravity 
1-45.  If  alcohol  be  present,  in  even  small  proportion,  an  effervescence  will  ensue, 
from  the  evolution  of  etherised  nitrous  gas,  with  its  characteristic  ethereous  smell. 
On  treating  the  mixture  with  a  nitrous  solution  of  mercury,  as  in  the  process  for  ful- 
minate of  inercurv,  an  effervescence  will  take  place,  the  dense  vapor  of  etherised 
mercurial  gas  will  appear,  and  a  certain  proportion  of  fulminate  will  be  formed,  cor- 
responding pretty  closely  to  the  proportion  of  alcohol  in  the  wood  naphtha  mixture. 
As  the  boiling  point  of  wood  spirit  is  only  about  145°,  while  that  of  alcohol,  of  like 
specific  gravity  (0-825),  is  173°  F.,  a  good  criterion  of  the  proportion  of  the  two  liquids 
present  m  the  mixture  may  be  found  in  its  boiling  temperature. 

Pure  wood  spirit,  when  mixed  with  the  above  nitric  acid,  becomes  of  a  ruby  tint, 
but  remains  tranquil.  Alcohol  continues  colorless,  but  enters  into  violent  ebullition! 
and  is  nearly  all  dissipated  in  fumes. 

Alcohol  diluted  with  water  has  a  less  resultant  density  than  wood  spirit  of  like 
strength  similarly  diluted.  While  alcohol  thus  becomes  of  0*920,  wood  spirit  becomes 
0-926  or  0-927. 

If  wood  spirit  be  contained  in  alcohol,  it  may  be  detected  to  the  greatest  minute- 
ness by  the  test  of  caustic  potash,  a  little  of  which,  in  powder,  causing  wood  spirit  to 
become  speedily  yellow  and  brown,  while  it  gives  no  tint  to  alcohol.  Thus  1  per  cent 
of  wood  spirit  may  be  discovered  in  any  sample  of  spirits  of  wine.  For  further  details 
upon  this  analytical  inquiry,  see  my  pamphlet  entitled  The  Revenue  in  Jeopardy. 

ALDEHYDE;  a  name  compounded  out  of  alcohol  dehydrogenated,  being  a  substance 
formed  by  depriving  alcohol  of  its  hydrogen.  The  process  is  too  intricate  for  descrip- 
tion here.  It  is  a  limpid  liquid,  of  0-790  specific  gravity,  boiling  at  21 '8°  C,  and  not 
reddening  litmus.  It  has  a  peculiar  ethereous  smell ;  when  its  vapor  is  inhaled  it 
causes  suffocation,  and  even  in  small  quantities  a  spasmodic  constriction  of  the  thorax. 
It  is  composed  of  4  atoms  of  carbon  =  24,  4  of  hydrogen  =  4,  and  2  of  oxygen  ==16* 
or  in  100  of  54  55,  9-09  and  36  S8  respectively.     It  is  very  inflammable.  * 

ALE.  The  fermented  infusion  of  pale  malted  barle}^  combined  with  infusion  of 
hops.     See  Beer. 

ALEMBIC,  a  Still  ;  which  see. 

v'^^^^P^^^^  ^^^^  ^^'  "^'^^  ^^^^  ^^  wisdom,  of  the  alchemists;  a  compound  of 
bichloride  of  mercury  and  sal  ammoniac,  from  which  the  old  white  precipitate  of 
mercury  is  made.  *^ 

ALGAROTH,  powder  of  A  compound  of  oxide  and  chloride  of  antimony  beinff 
*  Pa^J^^Pa^o  ^^Ar^^T^T**"^^  ^^  pouring  water  into  the  acidulous  chloride  of  that  metal 

ALGAROVILLA.  This  substance  is  called  by  the  Spaniards  Alqaroba,  from  the 
resemblance  it  bears  to  the  fruit  of  the  Carob  {Ceratonia  siliqua),  which  is  a  native  of 
Europe,  m  the  southern  countries  of  Spain  and  Portugal.  The  substance  lately  ana- 
lysed by  me  is  the  fruit  of  a  tree  which  grows  in  Chili,  of  which  the  botanical  name 
laJ^rosopis  pallida,  accordmg  to  Captain  Bagnald,  R.N.,  who  first  brought  a  sample 
of  it  to  this  country  in  the  year  1832.  It  consists  of  pods  bruised  and  agglutinated 
more  or  less  with  the  extractive  exudation  of  the  seeds  and  husks.  According  to  a 
more  recent  determination,  algarovilla  is  said  to  be  the  product  of  the  tree  Juga  Mar- 
thiE  of  Santa  Martha,  a  province  of  New  Carthagena. 

It  is  an  astringent  substance  replete  with  tannin,  capable,  by  its  infusion  in  water, 
of  tanning  leather,  for  which  purpose  it  possesses  more  than  four  times  the  power  ot 
good  oak  bark.  Its  active  matter  is  very  soluble  in  water  at  a  boiling  temperature. 
The  seeds  are  inerely  nutritive  and  demulcent,  but  contain  no  astringent  property. 
This  resides  m  the  husks.  The  seeds  in  the  entire  pod  constitute  aboSt  l-oth  of  the 
weight,  and  they  are  three  or  four  in  number  in  each  oblong  pod.  Alcohol  of  60  per 
cent  over  proof  dissolves  64  parts  in  100  of  this  substance.  The  solution  consists 
chiefly  of  tmnin,  with  a  very  little  resinous  matter.  Water  dissolves  somewhat  more 
of  It,  and  affords  a  very  styptic-tasted  solution,  which  precipitates  solution  of  isinglass 
very  copiously,  like  infusion  of  galls  and  catechu.  Its  solution  forms  with  sulphate  of 
iron  a  black  precipitate  which  is  kept  floating  by  means  of  the  gum  present,  and 
thereby  constitutes  good  ink.  My  report  to  the  merchant  was  written  with  a  com- 
bmation  thus  made,  in  proportions  taken  at  random;    and  there  is  no  doubt  that  by 


ss 


ALKALIMETER. 


ALKALIMETRY. 


38 


I 


nsing  a  stronger  decoction  of  the  algarovilla,  alon^  with  a  proper  proportion  of  cop- 
peraa,  an  excellent  black  ink  might  oe  prepared  without  any  other  addition. 

I  find  that  a  decoction  of  the  algarovilla  affords  with  cotton  cloth,  mordanted  with 
tin  solution,  as  also  with  acetate  of  alumina  liquor,  a  brilliant  yellow  dye  ;  the  former 
being  the  brighter  and  fuller  of  the  two. 

A  tincture  of  algarovilla  might  be  used  as  an  astringent  in  medicine ;  or  probably 
a  decoction  of  the  whole  substance  would  be  preferable,  on  account  of  the  demulcent 
quality  of  the  seeds  when  bruised.  As  an  article  of  commerce  it  cannot  be  rated  at  a 
high  price,  nor  should  it  pay  much  duty  till  its  value  as  an  article  of  manufactures  or 
medicine  be  fully  ascertained. 

ALIZARINE     See  Maddeh. 

ALKALL  A  class  of  chemical  bodies,  distinguished  chiefly  by  their  solubility  in 
water,  and  their  power  of  neutralizing  acids,  so  as  to  form  saline  compounds.  The 
alkalis  of  manufacturing  importance  are,  ammonia,  potash,  and  soda.  These  alkalis 
change  the  purple  color  of  red  cabbage  and  radishes  to  a  green,  the  reddened  tinc- 
ture of  litmus  to  a  purple,  and  the  color  of  turmeric  and  many  other  yellow  dyes  to 
a  brown.  Even  when  combined  with  carbonic  acid,  the  three  alkalis  exercise  this 
discoloring  power,  which  the  alkaline  earths,  lime,  and  barytes,  do  not  The  same 
three  alkalis  have  an  acrid,  and  somewhat  urinous  taste ;  the  first  two  are  energetic 
solvents  of  animal  matter;  and  the  three  combine  with  oils  so  as  to  form  soaps.  They 
unite  with  water  in  every  proportion,  and  also  with  alcohol ;  and  the  three  combine 
with  water  after  being  carbonated. 

ALKALI — ORGANIC;  or  organic  bases.  Many  plants  and  ingredients  of  plants 
which  exercise  a  powerful  specific  operation  upon  the  living  system  of  man  and  other 
animals  contain  peculiar  combinations  which  have  in  chemistry  a  decidedly  alkaline 
reaction  ;  and  have  hence  been  called  alkaloids.  They  unite  directly  with  both  hy- 
drogen and  oxygen  acids,  and  in  this  respect  differ  essentially  from  methyl  oxide,  ac- 
thyloxide,  and  amyloxide.  Sertiimier  was  the  first  discoverer  of  these  bases,  having 
recognised  in  opium  the  alkaloid  now  called  morphia.  Soon  afterwards  Pelletier  and 
Caventou  discovered  analogous  bases  in  the  strychnos  nux  vomica,  as  also  in  white 
hellebore.  As  these  bases  possessed  in  a  remarkable  degree  the  peculiar  action  of 
each  plant  upon  the  human  system,  chemists  set  themselves  diligently  to  search  in  the 
poisonous  and  narcotic  extracts  for  similar  principles.  From  the  discovery,  however, 
of  quinia,  cinchonia,  piperine,  <tc.,  it  appeared,  that  not  only  the  poisonous  ingredients 
of  plants,  but  others  possessed  of  peculiar  medicinal  qualities,  constituted  peculiar  al- 
kaloids. These  occur  in  plants  always  combined  with  organic  acids,  which  are  also 
often  of  a  peculiar  nature.  Thus  the  base  of  opium  occurs  combined  with  meconic 
acid,  and  the  base  of  chelidonium  with  chelidonic  acid.  The  acid  constituent,  how- 
ever, is  often  the  malic  or  one  of  the  forms  of  the  tannic. 

Wohler  first  made  the  discovery  that  through  the  decomposition  of  cyanate  of  am- 
monia urea  was  formed,  which  possessed  the  property  of  combining  with  several  acids, 
especially  the  nitric  and  oxalic,  under  like  conditions  with  the  bases  existing  in  nature. 
Unverdorben  extracted  from  animal  empyreumatic  oil  several  basic  compounds, 
such  as  odorine,  ammoline,  Ac,  and  Runge  out  of  coal-tar  obtained  kyanol  and  leukol. 
Fritszche  obtained  by  the  decomposition  of  anthranilic  acid,  aniline,  whose  identity 
with  kyanol  has  been  since  shown  by  Hofmann.  Zinin  made  the  discovery  that  by 
the  operation  of  sulphuretted  hydrogen  upon  nitrobenzide  and  upon  nitronaphtalide, 
certam  organic  bases  were  formed  with  separation  of  sulphur,  such  as  aniline,  benzi- 
dine, naphtalidine,  <fec.  Laurent  discovered  lophine  and  amarine,  bases  which  result 
through  the  operation  of  ammonia  upon  oil  of  bitter  almonds.  Thiosinnamine  is 
formed  by  the  action  of  ammonia  upon  the  volatile  oil  of  mustard,  <fec 

Composition  of  alkaloids*  or  organic  bases. — ^The  whole  of  these  bases  contain  nitro- 
gen combined  with  carbon  and  hydrogen,  and  most  of  them  contain  also  oxygen. 
These  alkaloids  combine  also  with  hydrogen  and  oxygen  acids,  as  ammonia  does,  and 
thereby  are  distinguished  essentially  from  acthyloxide,  methyloxide,  and  amyloxide. 
If  we  reckon  ammonia  as  a  hydrogen  basis,  the  organic  bases  must  belong  to  the  same 
category.  Their  oxygen  constituent  does  not  correspond  to  their  capacity  of  satura- 
tion, which  follows  from  the  fact,  that  alkaloids  exist  which  are  free  from  oxygen. 

The  production  of  the  organic  bases  is  different  according  as  they  belong  to  volatile 
or  non-volatile  bodies.  The  volatile  may  be  obtained  when  the  plants  in  which  they 
exist  are  distilled  with  a  somewhat  dilute  potash  lye.  The  distilled  liquor  contains 
always  besides  the  organic  base  a  little  ammonia.  It  is  to  be  exactly  saturated  with 
sulphuric  acid,  then  evaporated  by  gentle  heat,  and  the  remainder  treated  with  absolute 
alcohol  or  with  ether,  in  which  the  sulphuric  salt  of  the  organic  base  dissolves.  This 
solution  is  to  be  mixed  with  water,  the  spirit  is  to  be  distilled  off,  the  remainder  decom- 
posed with  potash  lye,  next  agitated  with  ether,  which  dissolves  out  the  alkaloid,  which 
remains  after  the  evaporation  of  the  ether.     In  this  way  nicotine  is  obtained.     The  non- 


Tolatile  bases  are  commonly  obtained  by  extracting  the  constituents  of  the  plant  with 
water  acidulated  with  sulpliuricor  muriatic  acid,  and  from  the  concentrated  solution 
precipitating  the  bases  by  means  of  an  alkaline  substance,  such  as  potash,  lime,  am- 
monia, or  magnesia.  The  precipitate  is  to  be  dried  and  boiled  in  alcohol,  which 
dissolves  the  alkaloid.  This  may  be  purified  by  repeated  crystallizations  aided  by 
animal  charcoal,  <fec. 

ALKALIMETER.  An  instrument  for  measuring  the  alkaline  force  or  purity  of 
any  of  the  alkalis  of  commerce.  It  is  founded  on  the  principle,  that  the  quantity  of 
real  alkali  present  in  any  sample  is  proportional  to  the  quantity  of  acid  which  a 
given  weight  of  it  can  neutralize. 

ALKALIMETRY.  Nearly  forty  years  have  elapsed  since  I  was  led,  by  peculiar 
circumstances,  to  construct  a  very  simple  method  of  testing  alkalis,  the  principle  of 
which  I  soon  afterward  applied  to  acids,  bleaching  powder,  dye-stufls,  and  most  other 
chemical  substances  extensively  used  in  manufactures.*  In  1814  and  1815,  during  the 
summer  vacation  of  my  Glasgow  classes,  I  was  engaged  in  delivering  courses  of  lectures 
on  chemistry  in  the  Belfast  Academical  Institution,  and  had  many  of  the  most  emi- 
nent members  of  the  Linen  Board  of  that  town  for  my  pupils.  Being  occasionally 
consulted  upon  the  qualities  of  the  alkalis,  which  were  used  to  the  value  of  200,000/.  by 
the  linen  bleachers  of  Ireland,  I  saw  the  importance  to  them  of  a  simple  alkalimetrical 
test,  both  for  purchasing  and  for  using  their  barillas  and  potashes.  The  following 
extract  from  the  Belfast  News  Letter^  of  July  9th,  1816,  will  show  the  nature  of  my 
contrivance : — 

"  This  day  one  ot  the  porters  of  the  Linen  Hall,  Belfast,  was  called  into  the  library- 
room  at  the  request  of  Dr.  Ure,  who  being  quite  unknown  to  Dr.  Ure,  and  never 
having  seen  any  experiments  made  with  acids  and  alkalis,  he  took  the  instrument  at 
our  desire,  which  being  filled  with  colored  acid,  by  pouring  it  slowly  on  adulterated 
alkali,  which  we  had  previously  prepared,  he  ascertained  exactly  the  per-centage  of 
genuine  alkali  in  the  mixture.     Belfast,  25th  June,  1816. 

"  John  S.  Fergusok,  Chairman. 

James  M*Donnel,  M.  D. 

John  M.  Stoupe. 

S.  Thomson,  M.  D." 

Of  these  gentlemen,  two  were  leading  members  of  the  Linen  Board,  and  the  others 
the  two  principal  physicians  of  the  town.  The  publication  of  the  details  of  my  method 
of  alkalimetry  was  delayed  till  arrangements  were  made  for  its  general  introduction, 
under  the  direction  of  the  Linen  Board  of  Dublin,  whose  professor  of  chemistry,  Mr. 
W.  Hig:gins,  as  well  as  Dr.  Barker,  professor  of  chemistry  in  Trinity  College,  granted 
certificates  of  the  "  accuracy  and  the  national  importance"  of  the  instrument.  The 
alkaline  matter  then  imported  into  Ireland  was  oflen  largely  contaminated  with  common 
salt,  even  to  the  extent  of  80  or  90  per  cent.  During  the  procrastination  of  the  Board, 
I  lent  my  Treatise  on  Alkalimetry  to  Dr.  Henry,  of  Manchester,  who  inadvertently  pub- 
lished an  account  of^  it,  though  with  reference  to  me,  in  the  next  edition  <>:  his  Elements 
of  Chemistry.  Having,  in  the  long  interval  since,  contrived  many  modifications  of  the 
instrument,  and  having  extended  its  principle  to  testing  other  articles  I  am  induced  to 
offer  it  now  to  the  world,  in  consequence  of  the  recent  appearance  of  a  publication  upon 
the  same  subject,  by  two  very  ingenious  chemists  of  Liebig's  school,  Drs.  R.  Fresenius 
and  H.  Will.  Of  their  system  of  alkalimetry,  &c.,  a  copious  abstract  appeared  in  the 
Annahn  der  Chimie  und  Pharmacie  for  July  last,  and  about  the  same  time  a  pamphlet 
was  published  by  Winter,  at  Heidelberg,  under  the  title  Neue  Verfahrungsweisen  zur 
Bestimmung  des  Werthes  der  Pottasche  und  Soda,  der  Sauren,  und  des  Braunstein;  or 
"New  Processes  for  determining  the  Value  of  Potash  and  Soda,  of  Acids,  and  Black 
Oxide  of  Manganese."  However  accurate  these  processes  may  be,  and  however  apt 
for  a  German  or  French  student  of  chemistry,  they  are,  in  my  apprehension,  not  at  all 
fitted  for  the  famihar  use  of  manufacturers  and  dealers  in  any  country,  and  certainly 
not  for  those  of  the  United  Kingdom. 

Descroizilles  was  the  first  person  who  contrived  an  instrument,  called  an  alkalim- 
eter,  to  ascertain  the  alkaline  strength  of  potash  and  soda,  without  much  calcula- 
tion. His  method  was  described  in  the  Annales  de  Chimie  for  1806,  tom.  Ix.. 
and  a  translation  of  it  appeared  in  our  Philosophical  Magazine,  vol.  xxviii.,  for  Jaly 

ul  !t^°^^  f*^®"  u?  "'"■**®  °^  potash,  nitrate  of  soda,«nd  to  white  lead,  either  in  powder  or  in  paint. 
My  nitrometer  enables  a  person  not  at  all  versant  in  chemistry  to  ascertain  in  a  quarter  of  an  hour. 
T^l  Lln?^  .*"*  processes,  the  quantity  of  pure  nitrate  in  either  of  these  salts,  to  one  part  in  200. 
The  cerussa-metei  is  equally  simple  and  expeditious,  r      "*  *"v. 


u 


ALKALIMETRY. 


ALKALIMETRY. 


86 


I 


and  August  of  the  following  year.  His  apparatus  consisted  of  a  glass  tube,  8  or  9 
inches  long,  and  7  or  8  lines  in  diameter,  closed  at  one  end,  but  terminated  at  the 
other  in  a  kind  of  small  funnel  (with  a  beak  or  spout),  connected  to  the  tube  by  a 
narrow  neck,  having  a  calibre  of  two  lines  and  a  half.  Upon  the  shoulder,  under 
the  throat,  there  was  a  hole  for  admitting  air  to  the  long  tube  in  the  act  of  being 
emptied,  by  sloping  its  mouth  downward.  This  cylindrical  vessel  was  to  contain 
38  grammes  of  water,  which  space  was  divided  into  76  equal  parts,  which  it  was 
extremely  important  to  proportion  accurately.  The  liquor  was  prepared  by  taking 
concentrated  sulphuric  acid,  at  66^  Baumc  (1'845  spec,  grav.),  and  diluting  it  with 
nine  times  its  weight  of  water.  The  instrument  being  poised  in  a  balance,  he 
introduced  into  it  very  exactly  two  grammes  of  the  above  test  acid,  and  when  the 
instrument  stood  upright,  he  scratched  a  line  at  the  level  of  the  liquor,  and  thus 
proceeded  by  addition  of  successive  grammes  to  graduate  the  whole,  till  36  were 
added,  after  which  he  subdivided  these  spaces  by  lines  into  72  demi-gramme  volumes. 
He  then  proceeds  to  describe  eight  different  subsidiary  articles  required  for  hb  oper- 
ations : — 

"  Mkalimetrical  trials  of  potash. — Weigh  exactly  one  demi-gramme  of  potash,  put  it  into 
a  glass,  and  pour  upon  it  about  four  fifths  of  a  decilitre  of  water ;  facilitate  the  solution  of 
the  potash  by  stirring  it  with  a  small  chip  of  wood,  three  or  four  times  in  an  hour  and  a 
half,  a  minutfe  at  each  time.  When  the  solution  is  effected,  pour  it  into  the  small  tin 
measure,  No.  4,  which  is  to  be  then  filled  up  with  water ;  pour  it  back  again  into  the 
glass,  in  which  you  must  still  pour  a  measure  full  of  pure  water;  stir  this  new  mixture 
also  three  or  four  times  within  half  an  hour,  in  order  to  facilitate  the  precipitation  of  a 
slight  sediment,  which  soon  falls  down.  This  sediment  being  completely  formed, 
slope  the  glass  with  caution,  in  order  to  fill  with  clear  liquor  the  small  measure  ;  then 
empty  this  last  into  another  large  glass ;  after  this  place  round  the  edges  of  a  plate 
drops  of  syrup  of  violets;  pour  also  into  the  alkalimeter  test  liquor  until  the  line 
marks  0 ;  take  it  afterward  with  the  left  hand,  inclining  it  upon  the  glass  which  con- 
tains the  moiety  of  the  clean  alkaline  solution :  the  acid  liquor  will  fall  into  it  by  hasty 
drops,  or  in  a  very  small  thread,  which  you  may  moderate  at  pleasure,  by  retarding  the 
entrance  of  the  air  at  the  lateral  hole  or  vent,  upon  which  must  be  placed  the  end  of 
the  finger ;  at  the  same  time,  with  a  small  stick  or  match,  assist  the  cixture  and  fa- 
cilitate the  development  of  the  carbonic  acid  which  is  manifested  by  effervescence. 
When  you  have  emptied  the  alkalimeter  to  about  the  line  40,  try  if  the  saturation 
approaches,  by  drawing  your  small  stick  from  the  mixture,  and  resting  it  upon  the 
drops  of  syrup  of  violets,  which  should  become  green,  if  the  potash  is  not  of  a  very 
inferior  quality.  If,  on  the  contrary,  the  violet  color  is  not  altered,  or  what  would 
be  worse,  if  it  be  changed  into  red,  there  would  be,  in  the  first  case,  an  indication  of 
saturation,  and  in  the  second  a  proof  of  super-saturation.  But  this  is  not  the  case  with 
good  potashes ;  at  that  line,  the  liquor  tried  can  alter  the  syrup  of  violets  into  green 
only ;  or  cause  to  return  to  the  violet,  and  even  to  the  green,  the  drops  which  had  been 
changed  into  red  at  the  time  of  a  former  trial ;  we  must,  therefore,  in  general  add  more 
acid,  which  occasions  a  new  effervescence.  This  addition  must  always  be  made  with 
caution,  and  we  must  touch  every  time  a  drop  of  syrup  of  violets  in  order  to  stop. 
When  at  last  the  latter  assumes  a  red  hue,  then,  after  having  restored  the  alkalimeter 
to  a  perpendicular  position,  in  order  to  see  at  what  line  the  testing  liquor  stops,  yon 
must  reckon  one  degree  less,  in  order  to  compensate  the  excess  of  saturation.  The 
mean  term  of  potashes  is  56;  this  implies  that  they  require  for  their  saturation  ^/y-;^ re 
hundredths  of  their  weight  of  sulphuric  acid." 

For  the  analysis  of  commercial  sodas  of  all  kinds,  M.  Descroizilles  prescribes  using 
ten  and  a  half  deci-grammes  of  this  alkali,  instead  of  the  ten  deci-grammes  for  potashes, 
and  proceeds  as  above  detailed.  In  his  table  of  results  annexed,  we  find  American 
potashes  called  60°  to  63°. 


American  pearlashes 
Dantzic  potash 
Alicant  soda 


bCP  to55«» 
4d    to  55 
20    to  33 


It  is  obvious,  from  these  statements,  that  the  alkalimeter  so  made  and  graduated 
denoted  comparative,  but  not  absolute,  quantities  of  alkalis  present  in  the  com- 
mercial samples.  The  rest  of  his  very  long  memoir  is  occupied  with  what  he  calls  the 
graduation  of  potashes  and  sodas,  the  economy  of  their  graduation,  the  proportions  of 
carbonic  acid  in  them,  the  processes  of  caustification,  the  presence  of  potash  in  all 
lime  which  is  burnt  by  a  wood  fire,  origin  of  neutral  soda,  and  probable  origin  of 
oatrum;  without  any  more  explicit  instructions.  The  instrument,  as  left  in  this  vague 
state,  never  was  employed,  nor  could  it  come  into  use,  among  English  manufBcturers 
and  dealers. 


The  next  alkalimeter,  of  which  an  account  has  been  published,  was  my  own.  In  con- 
structing this  instrument,  I  availed  myself  of  the  lights  recently  shed  on  chemical  pro- 
portions by  Dr.  Dalton's  atomic  theory,  and  I  thus  made  it  to  represent,  not  relative,  but 
absolute  measures  of  the  amount  of  real  alkali  existing  in  any  commercial  sample. 
The  test-liquor  used  at  that  time  was  sulphuric  acid,  which  is  most  readily  and  accurately 
diluted  to  the  requisite  degree  by  means  of  a  glass  bead,  very  carefully  made,  of  the 
specific  gravity  that  the  standard  acid  should  have.  In  order  to  make  the  test-liquor, 
therefore,  nothing  more  is  requisite  than  to  put  the  bead  into  distilled  water,  and  to 
add  to  it  somewhat  dilute  but  pure  sulphuric  acid,  slowly  and  with  agitation,  till  the 
bead  rises  from  the  bottom,  and  floats  in  the  middle  of  the  liquor  at  the  temperature  of 
60^  Fahr.  The  delicacy  of  this  means  of  adjustment  is  so  great,  that  a  single  degree  of 
increase  of  heat  will  cause  the  bead  to  sink  to  the  bottom — a  precision  which  no  hydrom- 
eter can  rival.  The  test-tube,  about  14  inches  long,  contains  generally  1,000  grains 
of  water,  and  is  graduated  into  100  equal  parts  by  means  of  equal  measures  of  mercury. 
The  test-liquor  is  faintly  tinged  with  red  cabbage  or  litmus ;  so  that  the  change  of 
color,  as  it  approaches  to  the  saturating  pitch,  on  adding  it  to  100  grains  of  the  com- 
mercial alkali,  becomes  a  sure  guide  in  conducting  the  experiment  to  a  succep^ful  issue. 
One  hundred  measures  of  this  test-liquor  neutralize  exactly  100  grains  of  absolute  soda 
(oxide  of  sodium),  and  of  course  very  nearly  150  of  potash.  A  bead  may  also  be  ad- 
justed for  test-liquors,  of  which  1,000  grain  measures  neutralize  100  of  potash,  and 
therefore  66f  of  soda,  as  well  as  other  proportions,  for  special  purposes  of  greater 
minuteness  of  research.  One  may  be  so  graduated  as  to  indicate  clearly  a  difference  of 
L_  of  a  grain  of  ammonia.  In  making  such  nice  experiments,  it  is  of  course  requisite 
to  free  the  alkaline  matter  beforehand  from  sulphurets,  sulphites,  and  hyposulphites,  by 
igniting  it  in  contact  with  chlorate  of  potash,  as  long  since  recommended  by  Gay- 
Lussac.  With  such  means  in  careful  hands,  all  the  problems  of  alkalimetry  may  be 
accurately  solved  by  an  ordinary  operator. 

On  the  same  principle,  my  Acidimeler  is  constructed ;  pure  water  of  ammonia  is 
made  of  such  a  standard  strength  by  an  adjusted  glass  bead,  as  that  1,000  grain  meas- 
ures of  it  neutralize  exactly  a  quantity  of  any  one  real  acid,  denoted  by  its  atomic 
weight,  upon  either  the  hydrogen  or  oxygen  scale  or  radix ;  as  for  example,  40  grains 
of  sulphuric  acid.  Hence  it  becomes  a  universal  acidimeter;  after  the  neutralization 
of  10  or  100  grains  of  any  acid,  as  denoted  by  the  well-defined  color  in  the  litmus- 
tinted  ammonia,  the  test-tube  measures  of  ammonia  expended  being  multiplied  by  the 
atomic  weight  of  the  acid,  the  product  denotes  the  quantity  of  it  present  in  10  or  100 
grains.  The  proportion  of  any  one  free  acid  in  any  substance  may  thus  be  deter- 
mined with  precision,  or  to  one  fiftieth  of  a  grain,  in  the  course  of  five  minutes.  Like 
methods  are  applied  to  Chlorometry,  and  other  analytical  purposes,  with  equal  facility ; 
adapting  the  test-liquor  to  the  particular  object  in  view.  Instead  of  using  beads  for 
preparing  the  alkalimetric  and  acidimetric  test-liquors,  specific  gravity  bottles,  or  hy- 
drometers, may  of  course  be  employed ;  but  they  furnish  incomparably  more  tedious, 
and  less  delicate  means  of  adjustment.  To  adapt  the  above  methods  to  the  French 
weights  and  measures,  now  used  generally  also  by  the  German  chemists,  we  need  only 
substitute  100  deci-grammes  for  100  grains,  and  proceed  in  the  graduation,  &c.,  as 
already  described. 

The  possession  of  two  reciprocal  test-liquids  affords  ready  and  rigid  means  of  verifi- 
cation. For  microscopic  analyses  of  alkaline  and  acid  matter,  a  graduated  tube  of 
small  bore,  mounted  in  a  frame  with  a  valve  apparatus  at  top,  so  as  to  let  fall  drops  of 
any  size,  and  at  any  interval,  is  desirable;  and  such  I  have  employed  for  many  years. 
Of  this  kind  is  my  ammonia-meter,  u^ed  in  the  ultimate  analysis  of  guanos  and  other 
azotized  products,  in  conjunction  with  a  modified  apparatus  on  the  principle  of  that 
of  Varrentrapp  and  Will.  It  may  be  remarked,  that  when  the  crude  alkali  contains 
some  hyposulphite,  it  should  not  be  calcined  with  chlorate  of  potash,  because  one  atom 
of  hyposulphurous  acid  is  thereby  converted  into  two  atoms  of  sulphuric,  which 
of  course  saturate  double  the  quantity  of  alkali,  previously  in  combination  with  the 
hyposulphurous  acid.  In  such  cases  it  is  preferable  to  change  the  condition  of 
the  sulphure'ts,  sulphites,  and  hyposulphites,  by  adding  a  little  neutral  chromate  of 
potash  to  the  alkaline  solution,  whence  result  sulphate  of  chromium,  water,  and 
sulphur,  three  bodies,  which  will  not  affect  the  accuracy  of  the  above  alkalimetrical 
l)roce8s. 

In  the  .Annals  of  Philosophy  for  October,  1817,  I  described  a  new  instrument  for 
analyzing  the  earthy  and  alkaline  carbonates,  and  for  determining  the  quantity  of  base 
present  in  them  from  the  volume  of  carbonic  acid,  disengaged  by  their  solution  in  acids, 
upon  the  data  of  the  atomic  theory.  This  method  was  applied  to  the  analysis  of  the 
carbonates  of  ammonia,  soda,  potash,  lime,  magnesian  limestone  (dolomite),  &c. 

"  The  indications  of  the  above  analytical  instrument  are  so  minute  as  to  enable  va, 
by  the  help  of  the  old  and  well-known  theorem  for  computing  the  proportions  of  two 


I 


36 


ALKALIMETRY. 


•^e^W  n^on^^-"^^  ^'^""i^l  ^^^"^  *"«y  t°  ^«^"<^e  the  proportions  of  the  bases  from 
.he  volume  of  gas  disengaged  by  a  given  weight  of  a  mix^  carbonate."' 

at  thP  oSt  instrument  consisted  of  a  bent  glass  tube,  open  at  one  end,  and  terminated 
?eauh-Pd  Sr  '*^•^''  egg-shaped  bulb  from  two  to  three  inches  in  diameterTnd  it 
Inn«l  t  ^^'ff^P^'^Vng  ^>th  it,  about  five  pounds  of  quicksilver.  The  foUowiireW 
apparatus  (Jig.    6)    wiU  be  found  more  generally  convenient,  and  equally  exTctf  Tis 

a  cylinder,  2  inches  in  diameter,  and  14  inches  long,  it  con- 
tains 10,000grainsofwater  in  the  graduated  portion;  0,  or  zero 
being  at  the  top.  It  has  a  tubulure  in  the  side  close  to  the 
bottom,  through  the  cork  of  which  a  short  tube  passes  tight,  and 
IS  connected  to  a  collar  of  caoutchouc,  e,  which  serves  for  a  joint 
to  the  upright  tube,  B,  resting  near  its  open  upper  end  in  a 
hooked  wire.     Through  the  cork  in  the  mouth  of  the  cylinder, 

in!n?t  w1!^  ""^A^^-  ^^'^  ""  P^''^'  air-tight.  The  small  tube  f 
open  at  both  ends,  is  cemented  at  bottom  into  the  taU  of  c,  and 

and Uni-^^  '^-^"i^f  ""[  '^'  ^'''^'  "^^^  '"^'^  ^^  ^  «  perfo/ated, 
t^th  ff 'l^'*'"''  ''^^  ^^^  taper  tube  r,  which  can  also  be  closed 
with  the  stopcock. 

In  operating  with  this  apparatus,  proceed  as  follows  :— 
J?  Ill  the  cylinder  with  water,  and  cover  its  surface  with  half 
an  inch  of  oil.  Insert  the  tail  of  the  flask.  Put  into  the  flask 
c,  58  6  grains  of  carbonate  of  potash,  or  45-2  of  carbonate  of  soda 
according  as  common  pearl-ash  or  soda-ash  is  to  be  tested,  alone 
with  as  much  water  as  wiU  cover  fully  the  lower  end  of  d,  and 
n/.?  ^^^'^^^."^^e  this  tube.  Have  a  bottle  containing  aboit  40 
Z  p/  T  L  r'il"''^?  previously  mixed  with  60  of  water,  and 
cooled.  1  ake  of  this,  m  a  pouring  or  dropping  glass,  100  water 
gram  measures,  and  suck  this  quantity  graduaUy  up  into  the  tube 
y,  then  shut  the  stopcock.  On  opening  it  slightly  the  acid  wiU 
tail  into  c,  and  as  slowly  as  may  be  prudent.  The  carbonic  acid 
gas,  forthwith  disengaged,  will  depress  the  water  in  a,  cause  an 
overflow  of  it  from  the  tube  b,  which,  being  held  in  the  left  hand, 
must  have  its  swanbeak  placed  over  a  basin,  and  progressively 

lS^''^^^.^^^  ^r^^  °^^^"  descending  water  in  the  cylinder! 
VVben  all  the  sulphuric  acid  has  been  introduced  by  the  right 
hand,  the  onfice  of  d  is  to  be  corked,  and  the  tube  b  continually 
lowered  with  the  left,  tiU  the  effervescence  being  finished,  the 
water  m  a  remains  stationary.  The  number  on  the  centi^ade 
ures  for  the  bulk  of  AlhZ.l'-^^^^A'i^  !?  ^^^  '"^^^'^  ""^  ^^^  °"'  deducting  100  grain  meas- 
LTorofsoda    "  tfp  «^^^^^^  •''''*^'  ^^^  per-centage  of  pure  carbonate  of  pot- 

f^n  nJu      *'       u    ^^^^^^  ""^^^  examination.    The  above  prescribed  wei-hts  of  these 
Hma"  SclSTo'^^^^^^^  ^^^^"^^^=^^  ^^^^  ^y  '^'  -^tion  of 's ulphurk  S  (us^^^ 
i^thf scale  on  i'ThP^'n^r  f  ^^V^Pl^^^^^s  of  carbonic  acid  gas,  or  lOO^ieasures 
measures     o  tha^thpwt ^^'^^fi[  ^^^  ^°"*^'"«  ^^«"t  12,000  water  grain 

S-theTwer  tubulure  tZ  f  ^^^f^t.^^ade  scale  is  fully  two  inches  above  the  level 
cenvLierin  cPrt«?n  V.e^  capacity  and  the  graduation  into  120  parts,  will  be  found 
Wrrav  PstTmaTp  imSn^  /'  '^^  '"  analyzing  bicarbonates  of  potash  and  soda.f 
weigh  1^  4  gri  ns  nni  t^^T?"^*"  ^-'^  measures  of  carbonic  acid  at  6(P  Fahr.,  to 
we  f  DD  ied  thP  rr;,w  !  *-^"'  ^T^'''^  ^^^^  ^  magnified  scale  we  should  possess  if 
r.  ««  o    1?  t^'V  ^^^'^  contrivance  here,  as  we  do  to  barometers.    At  any  rate  he  must 

the  a  W^::nsT^^^^^^^  -'^^  T  '^^^""^^  ^^^  ^'^^"^  «^^^  alkalineCbonateTby 
me  aoove  means,  to  one  part  m  a  thousand. 

standarf'wei^htTr.iv°''i!'°'''''  T'^''^  ^l'^  ^^-l  grains  should  be  taken  as  the 
out  on  soCfn  frf  H?i  7'  ^'^"'-^  ^^^^  ^"«^*  °^  P"^«  carbonate  of  lime  should  give 
IT.  4nio  inn  f^""^^  muriatic  acid  10,000  water  grain  measures  of  carbonic  acid 
gas.    Since  100  water  grain  measures  of  liquid  hydrochloric  acid,  specific  gravitvW4 

r;"d  rt'e'exo'^riment  ^Th'"  ''''  above  height' of  carbonates%KamUy  may  be 
used  in  the  experiment.  The  preceding  instrument  will  be  found  more  convenient  in 
expenmenting,  as  also  the  system  of  indication,  than  one  on  similar  priSes  con^ 
Btructed  by  the  ingenious  Dr.  Mohr,  of  Coblenz.  pnuupies  con- 

In  examining  bicarbonates  of  potash  and  of  soda,  the  weights  to  be  used  in  the  above 
apparatus  are  42  grams  of  the  former,  and  35i  ^ins  of  the  latter,  each  of  whiS 

»  Dictionary  of  Chemistry,  1821, 

t  For  the  greatest  precision  hot  acid  may  he  used  in  the  above  exnerimpnt  hv  fairi-»,«.  i«  . a    .  j 


ALKALIMETRY. 


87 


quantities,  if  the  salts  b«  perfect,  will  disengage  10,000  water  gram  measures  of  car- 
bonic acid  gas,  by  the  action  of  sulphuric  acid.  There  will  be  no  harm  in  taking  the 
formerly  prescribed  measure  of  the  sulphuric  acid  though  considerably  less  would 
answer  the  purpose.  The  centigrade  measures  of  gas  obtained  in  A  will  indicate  the 
carbonated  state  of  the  two  alkalis  respectively.  Their  alkaline  force  may  be  most 
readily  ascertained  by  my  old  alkalimeter,  with  colored  test  acid.  Since  the  bicar- 
bonates usually  sold  in  our  shops,  especially  that  of  soda,  are  far  from  being  exact 
atomic  compounds,  they  should  be  always  examined,  both  for  their  base  and  acid, 
which  may  also  be  well  done  in  the  following  way,  where  the  quantity  of  carbonic  acid 
gas  is  determined  by  weight  instead  of  by  volume. 
For  this  purpose,  a  small  compact  apparatus  of  the  annexed  form  (yig.    7)    will  be 

found  convenient ;  it  is  to  be  used  in  conjunction  with  my 
alkalimeter.  a  in  the  dotted  line  is  the  phial  for  receiving 
the  carbonate  to  be  tested,  b,  the  funnel  into  which  the 
test  acid  is  to  be  poured ;  c  c,  an  inverted  syphon  filled 
with  pieces  of  chloride  of  calcium  for  absorbing  the  aqueous 
vapors  exhaled  by  the  carbonic  acid.  The  loss  of  weight 
in  the  phial  above  that  in  the  tube  of  test  acid  shows  the 
quantity  of  acid  gas,  and  the  indication  of  the  alkalimeter 
tube,  that  of  alkaline  base,  from  which  data  the  proportion 
of  neutral  carbonate  and  bicarbonate  may  be  immediately 
deduced.  Thus,  100  grains  of  bicarbonate  of  soda  should 
give  out  51|  grains  of  carbonic  acid,  and  saturate  37*6  cen- 
tigrade measures  of  the  test  acid,  equivalent  to  37*6  grains 
of  real  soda.  But  if  neutral  carbonate  of  soda  be  present, 
less  gas  will  be  given  out,  and  more  or  less  alkali  may  be 
indicated,  according  to  the  degree  of  dryness  of  the  neutral 
soda.  The  amount  of  water  in  the  bicarbonate  may  be  de- 
termined by  igniting  20  grains  in  a  test  tube,  connected  with 
the  chlorcalcium  inverted  syphon ;  10 J  grains  of  carbonic 
acid  gas  should  be  expelled,  and  2J  of  water,  making  a  total 
loss  of  1211  grains,  of  which  2|  will  be  found  as  water  ab- 
sorbed by  the  chlorcalcium.  But  since  a  very  moderate  heat 
suflices  to  expel  the  second  atom  of  carbonic  acid  from  the 
bicarbonate  of  soda,  the  readiest  mode  of  estimating  its 
quality  is  to  heat,  over  a  spirit  lamp,  in  a  small  flask,  or 
retort,  connected  air-tight  by  a  tube  with  the  mouth  of  the 
cylinder  a,  {fig.  6)  70|  grains  of  the  supposed  bicarbon- 
ate. Of  the  perfect  salt  this  quantity  should  give  out  pretty 
exactly  10,000  grain  measures  of  gas ;  and  whatever  aliquot  part  of  this  volume  is 
evolved  will  indicate,  without  calculation,  the  relative  value  of  the  substance  as  a 
bisalt.  Thus  if  8,500  grain  measures  of  gas  are  obtained,  85  parts  of  bicarbonate 
of  soda  are  present  in  100.  The  crystalline  form  ofbicarbonate  of  potash  is  a  tolerably 
good  criterion  of  its  quality. 

The  quantity  of  caustic  alkali  mixed  with  carbonate  may  be  readily  determined, 
with  sufficient  accuracy,  by  the  expert  use  of  my  alkalimeter ;  because,  till  the  caustic 
portion  be  nearly  neutralized,  little  or  no  carbonic  gas  is  expelled.  When  the 
effervescence  at  length  begins,  the  test  measures  already  expended  denote  the  per- 
centage of  caustic  alkali.  It  is  not  right  to  disregard  the  alkali  which  is  present  in  the 
slate  of  sulphuret,  because  as  such  it  is  effective  in  many  processes  of  the  chemical  arts; 
in  the  manufacture  of  yellow  soap,  crown  glass,  in  the  bleaching  of  linen  and  cotton 
goods,  &c.  The  alkalimeter,  directly  applied,  will  show  the  alkali  present  in  this  form, 
when  compared  with  that  indicated  after  ignition  of  the  crude  alkali  with  chlorate  of 
potash,  or  after  its  treatment  with  yellow  chromate  of  potash.* 

A  few  years  ago  I  had  the  following  apparatus  made  for  the  ready  analysis  of  car- 
bonates, by  ascertaining  the  loss  of  weight  they  suffered  from  the  disengagement  of  their 
carbonic  acid  gas,  during  their  solution  in  an  acid,  a,  b  {fig.  8)  are  two  globes,  of  about 
two  inches  in  diameter  each ;  a  has  its  inferior  neck  strangled  into  a  bore  nearly  capil- 
lary ;  b  stands  lower,  with  its  centre  line  on  a  level  with  the  narrow  neck  of  b.  The 
tubes  of  these  globes  are  about  one  half  inch  in  diameter,  c  is  shut  at  top  with  a  per- 
forated cork,  through  which  enters,  air-tight,  a  small  glass  tube,  which  is  bent  across  to 
the  mouth  of  the  tube  e,  and  then  passes  down  into  it  a  little  below  the  centre  line  of 

*  If  the  alkaline  carbonate  contains  sulphuret,  sulphite,  or  hyposulphite,  a  teaspoonful  of  vellow 
chromate  of  potash  may  be  added  tc  it,  wherefrom  result  sulphate  of  chromium,  water,  and  sulphur, 
which  remainm  the  apparatus  without  effecting  its  weight.  The  mutual  action  of  neutral  chromate  of 
potash  and  of  sulphuret  of  potash,  &c.,  has  been  discussed  in  an  ingenious  paper  pubUshed  by  Doppin^ 
In  the  AnnaUH  dtr  Chtmte  for  May,  1843,  p.  17«.  r  r     r  /      rf  "•* 


S8 


ALKALIMETRY. 


ALKALIMETRY. 


M 


If! 


the  globe  b.    This  globe  is  rather  more  than  half  filled  with  sulphuric  acid,  when  the 
instrument  is  employed  in  the  analysis  of  the  carbonates.     The  standard  weight  of  car- 
bonate of  soda  =  24^  grains,  or  of  carbonate  of  potasn  = 
31 J  grains,  is  then  put  into  a,  having  previously  laid  a 
minute  globe  of  glass  over  the  lower  orifice ;  the  cork, 
with  its  small  tube,  is  now  firmly  adjusted ;  and  the  appa- 
ratus is  weighed  in  its  upright  position,  either  by  suspen- 
sion with  a  hook  to  the  end  of  the  beam,  or  by  resting  it  on 
the  scale  in  a  light  socket  of  any  kind.    It  is  next  laid  hold 
of,  and  inclined  so  as  to  cause  a  little  of  the  acid  in  b  to  pass 
over  into  a.    Effervescence  ensues  with  greater  or  less 
vehemence,  according  to  the  nature  of  the  carbonate  and 
quantity  of  the  acid  introduced.     Should  it  be  too  violent, 
and  threaten  an  overflow  by  intumescence,  it  can  be  in- 
stantly abated  to  any  degree  by  the  slightest  slope  of  the 
instrument.    Now,  this  power  of  control  forms  the  pe- 
culiar feature  and  advantage  of  this  contrivance ;  whereas 
in  all  other  forms  of  such  apparatus  that  I  know,  whether 
by  sucking  over  or  pouring  in,  if  a  little  too  much  acid 
comes  upon  the  carbonate,  the  experiment  is  effectually 
marred.     The  gas  disengaged  in  a  must  necessarily  tra- 
verse the  sulphuric  acid  in  b,  and  be  stripped  of  ita 
moisture  before  escaping  into  the  air.    Having  super- 
saturated the  alkaline  base,  and  cooled  the  apparatus, 
we  weigh  it  again,  and  the  loss  of  weight  in  grains  and 
tenths  denotes  the  per-centage  of  soda  or  potash,  provided 
their  neutral  carbonates  had  been  the  subjects  of  experi- 
ment.    For  limestone,  on  the  same  plan  of  computation, 
22|  grains  may  be  taken.  It  deserves  to  be  noted,  that  the 
•M««j^    r     1  •  1-  .       present  instrument  has  only  one  junction,  and  needs  no 

wntain  it  •"™'  *  substance  so  apt  by  its  swelling  to  burst  the  glass  tubes  that 

II.  acidimetry. 

-,JK^T  ^^'^^^^^  ^^^^^^'  *^^*  ^*^"  ®^  ammonia  of  standard  strength,  faintly  tinted 
With  ntmus,  affords  a  most  exact  and  convenient  acidimeter,  when  poured  or  let  fall 
I«°S«*t  f  nn^^  •  ^'^°PPi«S-t»l>e.  Bicarbonate  of  potash  also,  when  dissolved  in  water, 
so  that  1,000  gram  measures  contam  one  atom  of  the  salt  counted  in  grains,  is  a  good 
test-hquor  for  the  same  purpose  ;  for  if  the  centigrade  measures  expended  ii  effectine 

n,!oir»  ^^*'**''  "^  multiplied  by  the  atomic  weight  of  ihe  ^iven  acid,  the  product  is  thi 
quantity  m  grams  of  acid  present.  »        f  ^^ 

r.fil^t^'^'^  ^""lu^  likewise  exactly  performed  by  measuring  in  the  cylindric  gas- 
meter  (^g.  6)  the  volumes  of  carbonic  acid  gas  disengaged  from  pure  bicarbonate  ol 
potash  or  soda,  by  a  given  weight  of  any  acid,  taking  care  to  use  a  small  excess  of  the 
f}l'  JnS  ^°'"/^^'»Pl«»  16-8  g'^ains  o^  dry  and  20f  of  hydrated  sulphuric  acid  disen- 
gage  10,000  water  grain  measures  of  gas  from  bicarbonate  of  potash.  Therefore,  if 
20*  grams  of  a  given  sulphuric  acid  be  poured  into  the  flask  of^g.  6,  upon  about  50 
grains  of  the  bicarbonate,  powdered  and  covered  with  a  little  water,  it  will  cause  the 
evolution  of  a  volume  of  gas  proportioned  to  its  strength.  If  the  acid  be  pure  oil  of 
vitriol,  that  weight  of  it  will  disengage  10,000  grain  measures  of  gas;  but  if  it  be 
weaker,  so  much  less  gas— the  centigrade  measures  of  which  will  denote  the  per-cent- 
age value  of  the  acid.  If  the  question  be  put,  how  much  dry  acid  is  present  per  cent, 
m  a  given  sulphuric  acid,  then  16-8  grains  of  the  acid  under  trial  must  be  used;  and 
the  resulting  volume  of  carbonic  acid  gas  read  on  the  scale  wiU  denote  the  per-cekta«e 
of  dry  acid.f  *^  * 

For  nitric  acid,  we  should  take  22-6  grains;  for  hydrochloric  ormuriaUc  acid,  15-34 ; 
for  acetic  acid,  21-6 ;  for  citric  acid,  24-6 ;  for  tartaric  acid,  28  grains:  then  in  each 
case  we  shaU  obtain  a  volume  of  carbonic  acid  gas  proportioned  to  the  strength  and 
punty  of  these  acids  respectively.  The  nitric,  hydrochloric,  and  acetic  acids  are  re- 
ferred to  m  their  anhydrous  state ;  the  tartaric  and  citric  in  their  crystalline.  If  the 
latter  two  acids  be  pure,  a  solution  of  24-6  grains  of  the  first  and  of  28  of  the  last 

*  1,000  water  grain  measures  of  sulphuric  acid  of  specific  gravity  1-032,  or  32  above  water,  neutralize 
32  grains  of  soda,  and,  consequenUy,  one  atom,  on  the  hydrogen  scale,  of  each  of  the  other  basM 
reckoned  in  grains.  "mci  ua9«^. 

Having  in  the  course  of  many  years  subjected  my  tables  of  sulphuric,  nitric,  and  muriatic  acids  as 
well  as  of  ammonia,  to  strict  cross-examination,  1  have  found  them  trustworthy  for  all  alkalimetric^ 
and  acidimetncal  purposes.  '  aiAJuunemcai 

^JtA^^^^  bicarbonate  must  be  free  from  carbonate,  a  point  easily  secured  by  washinr  its  powder  with 
cold  water,  and  drying  it  in  the  air.  ^  j  j  ^mmum^  »•  |wwaer  wiu 


will  disengage  from  60  grains  of  bicarbonate  of  potash  10,000  grain  measures  of  car- 
bonic acid  gas.*  ,  .  .  •  •  ,.  •  ij  i> 
Acidimetrical  operations  may  likewise  be  performed  by  determining  the  weight  of 
carbonic  acid  gas  expelled  from  the  bicarbonate  of  potash  or  soda,  by  a  given  quantity 
of  any  acid,  in  the  apparatus  either ^g.  7,  or  fig.  8.  Here  the  weights  to  be  takea 
are  as  follows,  in  reference  to 


Grains. 

9-127 
12-33 

8-29 
11-67 
13-31 
15-13 


Dry  Sulphuric  acid      -        -        - 

"    Nitric 

"     Hydrochloric        -        -        - 

**    Acetic  -        -        -        - 

Crystallized  Tartaric  -        -        - 

«  Citric       .        -        - 

Each  of  these  quantities  of  real  acid,  with  25  or  26  grains  of  bicarbonate  of  potash, 

will  give  off  10  grains  of  carbonic  acid  gas  ;  and  hence  whatever  weight  the  apparatus 

loses,  being  reckoned  in  grains  and  tenths  of  a  grain,  denotes  the 
per-centage  of  acid  in  the  sample  under  trial,  without  the  ne- 
cessity of  any  arithmetical  reduction.  Pei-sons  accustomed  to 
the  French  metrical  system  may  use  deci-grammes  instead  erf" 
grains,  and  they  will  arrive  at  the  same  per-centage  results. 

The  preceding  experiments,  in  reference  to  the  weight  of  car- 
bonic acid  gas  expelled  for  the  purpose  of  either  alkalimetry  or 
acidimetry,  may  also  be  made  by  means  of  the  ordinary  apparatus 
represented  in  jig.  9.  a  is  a  small  matrass  which  contains  the 
acid  or  carbonated  alkali  at  its  bottom ;  and  conversely  the  alkali 
or  acid,  for  their  mutual  decomposition  in  the  small  test-tube, 
shown  first  at  h  nearly  upright  and  filled,  but  afterward  at  a, 
horizontal  and  emptied,  b  is  a  bulbous  tube  filled  with  frag- 
ments of  chlorcalcium  for  absorbing  the  aqueous  vapor  that 
rises  with  the  carbonic  acid  gas,  and  c{  c  is  a  small  bent  tube 
which  dips  into  the  Uquid  in  the  matrass.  The  weighings,  &.C., 
may  be  conducted  as  already  detailed ;  and  when  the  effer- 
vescence is  completed,  the  residuary  gas  is  sucked  up  through 
B,  while  the  atmospheric  air  enters  to  replace  it  at  the  orifice  d 
of  the  bent  tube. 

The  NEW  methods  which  pervade  the  whole  treatise  of  Drs. 
Fresenius  and  Will  are  all  based  on  the  principle  of  estimating 
alkalinity,  acidity,  and  the  oxygen  in  manganese  (or  chlorom- 
etry)  by  the  weight  of  carbonic  acid  gas  evolved.  As  in 
taking  these  measures  the  gas  must  be  discharged  without 
carrying  water  off  with  it,  an  elegant  and  ingenious  little  piece 
of  apparatus  has  been  invented  by  the  authors  for  effecting  that 
purpose,  and  it  will  do  it  well,  a  and  b  (^g.  10)  are  two  flasks  (wide-mouthed 
medicine-bottles  may  be  employed),     a  must  have  a  capacity  of  from  2  ounces  to  2| 

ounces  of  water ;  it  is  advisable  that  b  should  be 
somewhat  smaller,  say  of  a  capacity  of  about  1  to 
\\  ounces.  Both  flasks  are  closed  by  means  of 
doubly  perforated  corks.  These  perforations  serve 
for  the  reception  of  the  tubes  a,  c,  and  d,  c  is  a 
tube  bent  twice  at  right  angles,  which  enters  at 
its  one  end  just  into  the  flask  a,  but  descends  at 
its  other  end,  near  to  the  bottom  of  b.  These  tubes 
are  open  at  both  ends  when  operating ;  except  the 
top  end  6  of  the  tube  a,  which  is  closed  by  means 
of  a  pellet  of  wax.  The  substance  to  be  ex- 
amined is  weighed  and  put  into  the  flask  a,  into 
which  water  is  then  poured  to  the  extent  of  one 
third  of  its  capacity.  b  is  filled  with  common 
English  sulphuric  acid  to  about  half  its  capacity. 
Both  flasks  are  then  corked  (by  which  they  be- 
come united  by  the  rectangular  tube),  and  the  ap- 
paratus is  weighed. 

The  air  of  the  whole  apparatus  is  next  rarefied  by 
applying  suction  to  the  tube  d :  the  consequence  is, 
that  the  sulphuric  acid  contained  in  b  ascends  into 

^*  The  expulsion  of  the  gat  may  be  completed  by  surrounding  the  flask  with  a  towel  dipped  in  hot 


40 


ALKALIMETRY. 


Jntn  n^nt  '♦  I  "u  "  ^J^''''  **^  ^^  ^^^^  ovcr  into  B.  Immediately  upon  its  coming 
into  contact  with  the  carbonate  contained  in  a,  carbonic  acid  gas  is  disengaged  and  in 
Its  escape  must  necessarily  traverse  the  oU  of  vitriol  in  b,  and  therein  deposite  all  its 
aqueous  vapor  before  issuing  from  d.  The  sulphuric  acid  in  passing  over  into  a  heats 
tne  mixture  at  the  same  time,  and  thus  promotes  the  expulsion  of  the  gas.  Whenever 
this  ceases  to  flow,  a  little  more  sulphuric  acid  must  be  sent  over  into  a  by  suction 
irom  rf  (or  rather  from  a  recurved  tube  attached,  pro  tempore,  to  it)  ;  an  artifice  which 
may  be  repeated  till  no  more  gas  can  be  expelled,  even  when  the  contents  of  a  are 
Heated,  as  they  must  be  at  the  end  by  the  excess  of  oil  of  vitriol. 

*•  From  the  aperture  6  of  the  tube  a,  which  has  been  aU  the  time  closed,  the  bit  of 
wax  IS  now  to  be  removed,  and  to  the  tube  connected  with  d,  suction  is  to  be  applied, 
tUl  all  the  carbonic  acid  lodged  in  the  apparatus  be  replaced  by  atmospheric  air.     The 
whole  is  to  be  then  cooled,  wiped,  and  weighed;  the  loss  of  weight   indicates  exactly 
Uie  quantity  of  carbonic  acid  which  existed  in  the  carbonate  submitted  to  experiment 
Ihe  process  is  no  less  neat  than  it  is  simple,  and  does  honor  to  the  ingenuity  of  its  in- 
ventors.    Their  mode  of  deducing  the  percentage  of  alkali  from   the  quantity  of 
carbonic  acid  discharged  m  the  operation  is  also  quite  exact,  and  suitable  for  con- 
tinental  chemists  familiar  with  gramme  weights  and  calculations,  but  certainly  not  for 
persons  conversant  only  with  ounces,  drams,  and  scruples,  or  even  with  grain  subdi- 
visions.   The  whole  book,  however  excellent,  needs,  for  the  British  public,  transpo- 
«tion,  before  It  can  serve  in  this  country  the  purpose  intended  by  its  scientific  authors. 
Ihus,  in  section  4,  where  several  results  of  their  analyses  are  given,  the  statements 
have  a  somewhat  mysterious  aspect.     Should  any  one  ask  why  the  oracular  number  of 
4-83  grammes  of  carbonate  of  soda  is  used  as  their  standard  wei-ht  for  analysis,  he 
can  obtain  no  response  in  the  book,  either  in  a  note  or  anywhere  else.    A  Germai  or 
fw"i  c?  '  familiar  with  chemical  computation,  will  probably  be  able  to  discover 

mat  4-8d  grammes  of  pure  carbonate  of  soda  contain,  by  Berzelius's  tables  of  atomic 
weights,  2  grammes  of  carbonic  acid;  for  53-47  (1  atom  of  carbonate) :  22-15  (1  of 
carbonic  acid) : :  4-83  :  2-00.  Such  is  the  simple  solution  of  this  apparent  enigma, 
and  of  some  other  similar  puzzles  in  the  book.  Indeed,  unless  the  reader  is  aware  of 
tfiat  proportion,  he  can  not  see  the  grounds  of  the  accordance  in  the  results  between 
experiment  and  theory,  or  why  the  numbers  2-010,  1.993,  and  2-020,  are  presented  as 
specimens  of  great  precision.  This  accordance  gives  satisfaction  when  it  is  known 
that  these  numbers,  in  experiments  1,  2,  and  3,  oscillate  on  one  side  or  other  so  near  to 
A  aar^'^^n-  "''°"^^'"  ^'^^'  ^"^  ^  grammes  and  83  centi-grammes,  as  also  1  gramme 
and  yy5  miUi-grammes,  are  awkward  weights^  for  an  ordinary  English  chemist  or 
apothecary,  which  would  require  a  month  or  two's  residence  in  the  laboratories  of 
tfiessen  and  Pans  to  manipulate  with  readiness. 

Again,  m  testing  carbonate  of  potash,  our  authors  take  6-29  grammes  as  their  unity  of 
weight,  undoubtedly,  because,  if  pure,  it  should  discharge,  by  saturation  with  the  sul- 
phuric acid,  2  grammes  of  carbonic  acid.  Here,  however,  they  have  not  stuck  so  rigidly 
as  the  school  of  Giessen  usually  does  to  Berzelius's  atomic  numbers;  for  his  atom  of 

o^c^i!  oL'^il^^  '^  ^^'^2  5  whence,  22-15  :  69-42  : :  2-00  :  6-68,  hydrogen  =  1-00 : 
or  276-44  :  866-33  :  :  2-00  :  6-268  oxygen  =  100.  ' 

Admitting  the  value  of  the  new  method  in  testing  neutral  carbonates,  it  can  not  be 
airecijy  applied  to  the  mixed  carbonate  and  bicarbonate  of  soda,  so  commonly  sold 
in  this  country  for  bicarbonate;  nor  is  it  applicable  to  the  case  of  a  mixture  of  caustic 
and  carbonated  alkali,  without  the  tedious  process  of  previous  treatment  with  car- 
bonate of  ammonia  and  heat. 

The  new  German  method  of  acidimetry  consists  in  determining  how  much  carbonic 
acid  gas  is  disengaged  from  a  standard  bicarbonate  of  soda,  by  a  given  weight  of  any 
acid.  The  twin-flask  apparatus  (Jig.  10)  is  used.  The  weighed  portion  of  acid  is 
put  into  a,  and  a  sufficient  quantity  of  the  soda  into  a  test-tube,  which  is  suspended 
upright  with  a  silk  thread  fastened  by  the  pressure  of  the  cork  to  the  mouth  of  the 
flask.  On  letting  the  thread  loose,  the  test-tube  falls,  and  the  cork  being  instantly  re- 
placed, the  whole  gas  evolved  is  forced  to  pass  through  the  sulphuric  acid  in  b,  and 
there  to  deposite  its  moisture.  The  experiment  is  conducted  in  other  respects  as  already 
described  lor  alkalimetrj'. 

The  following  extract  from  Drs.  Fresenius  and  Will's  New  Methods  of  jSUealimetn/t 
&c.,  will  show  the  Giessen  plan  of  calculating  results  :— 

"  The  amount  of  anhydrous  acid  contained  in  the  hydrated  acid  under  examination 
IS  determined  from  the  amount  of  carbonic  acid  escaped,  as  follows  : — 

"Two  measures  of  carbonic  acid  bear  the  same  proportion  to  one  measure  of  the 
anhydrous  acid  in  question,  as  the  amount  of  carbonic  acid  expelled  does  to  the  amount 
sought  of  anhydrous  acid.  Thus,  let  us  suppose,  for  instance,  we  have  examined 
dilute  sulphuric  acid,  and  obtained  1-5  grammes  of  carbonic  acid,  the  arrangement 
would  he : — 


'; 


ALKALIMETRY. 

550  (2  X  275)  :  501  =  1-5  :  x 

x=l-36. 


41 


The  amount  of  sulphuric  acid  operated  upon  consequently  would  contain  1-36 
eramraes  of  anhydrous  acid.  Let  us  suppose  the  weight  of  this  amount  to  have 
been  15  grammes,  the  sulphuric  acid  under  examination  would  contain  a  per-centage 

amount  of  9*06 ;  for 

15  :  1-36  =  100  :  x 
a;  =9-06."* 

«  Section  XXIX.  Stating  the  Quantities  of  the  various  Jcids  to  be  used  in  their 
Examination. — To  enable  our  readers  at  once,  without  the  trouble  of  calculation,  to 
determine  from  the  weight  of  carbonic  acid  expelled,  the  exact  amount  of  anhydrous 
acid  contained  in  those  acids  which  are  of  most  frequent  occurrence,  we  have  subjoined 
lists  of  certain  quantities  to  be  taken  of  each  acid  for  experiment,  so  that  the  number 
of  centi-grammes  of  carbonic  acid  expelled  will  directly  indicate  the  per-centage  amount 
of  anhydrous  acid  in  the  acid  under  examination. 

"  Multiples  of  those  weights  may  of  course  be  substituted  for  the  numbers  given, 
according  to  the  degree  of  dilution  of  the  acid  under  examination.  In  such  cases  the 
number  of  centi-grammes  of  the  carbonic  acid  expelled  must  be  divided  by  the  same 
number,  which  has  served  as  the  multiplier. 

"  These  numbers  are  obtained  by  dividing  the  atomic  weight  of  the  acid  by  550 
(2  X  275,  one  eq.  of  carbon),t  as  follows : — 

"Two  eq.  of  carbonic  acid,  corresponding  to  one  eq.  of  the  acid  to  be  exam- 
ined, how  much  should  be  taken  of  the  latter  to  expel  1-00  grammes  of  carbonic 
acid? 

**  The  arrangement  of  sulphuric  acid,  for  instance,  is  as  follows : — 

550  :  501  =  1-00  :  x 

x=:0-91  (or,  more  correctly,  0-911). 

"  When  examining  acids,  it  is  most  advisable  to  use  that  multiple  of  the  unity  (ac- 
cording to  the  degree  of  concentration)  which  will  expel  from  one  to  two  grammes  oi 
caibonic  acid. 

"l.    SULPHURIC   ACID. 


"  Unity  0-91  grammes  (or,  more  correctly,  0*911 

grammes). 

**  Multiples : — 

2  X  0-911  =    1-822  grammes. 

3  X  0-911  =    2-733 

(C 

4  X  0-911  =    3-644 

(C 

5  X  0-911  —    4-555 

« 

6  X  0-911  =    5-466 

« 

7  X  0-911  =    6-377 

« 

8  X  0-911  =    7-288 

« 

9  X  0;911  =    8-199 

« 

10  X  0-911  =    9-110 

« 

15  X  0-911  =  13-665 

(C 

20  X  0-911  =  18-220 

(t 

30  X  0-911  =  27-330 

«  &c. 

"Thus,  knowing  that  0-91  of  anhydrous  sulphuric  acid  will  expel  1-00  of  carbonic 
acid,  it  will  be  easy  to  determine  what  multiple  ought  to  be  used,  according  to  the  de- 
gree of  concentration  of  the  acid  to  be  examined."! 

ni.    CHLOKOMETRY, 

^thd  the  testing  of  Black  Oxide  of  Manganese  for  its  available  Oxygen, 

The  value  of  manganese  may  be  estimated  very  exactly  by  measuring  the  quantity 
of  chlorine  which  a  given  weight  of  it  produces  with  hydrochloric  acid ;  the  chlorine 
boing  at  the  same  time  estimated  by  the  quantity  of  solution  of  green  sulphate  of  iron, 
which  it  will  peroxidize.  A  process  of  this  kind  was  long  ago  practised  with  chloride 
of  lime  (bleaching  powder  or  liquor)  by  Dr.  Dal  ton;  and  it  has  been  since  improved 
by  Mr.  Waltercrum.  As  the  conversion  of  two  atoms  of  green  sulphate  of  iron  into 
red  sulphate  requires  only  one  atom  of  oxygen,  this  change  may  be  effecti^d  by  the 
reaction  of  one  atom  of  chlorine  in  liberating  one  atom  of  oxygen,  while  this  appro- 
priates one  of  hydrogen  from  the  hydrochloric  acid. 

♦  Nev  Methois  of  Alkalimetry,  «fc.,  pp.  93,  94. 

t  A  typofnnphical  error  in  Mr.  Bullock's  edition  ;  it  should  be  carbonic  acid. 

tlfeto  Methods  of  Alkalimetry,  ^.,  pp.  103-105. 


4S 


I 


I 


ALKALIMETRY. 


4 


and  this  weight  is  eqJvilen?  to  3^6 ^o Am  "-^^  =  ^S^  ^  ^^  of  wate^^  726  ^X-^OTfi^ 

,^     manganese  to  be  testeTanS  in'?o^hV\^K' ^^^  ^'»«  ^^the 

of  t?  a^^alin^etrical  tubi  Xg^ej^thfooo  .^'  '^^  ^^^^  «"^ 
of  the  above  equivalent  codhp^  witn  i,000  grain  measures 
grain   measures,   according  ?o^h  '^"*'°"'  ^^^"^  200  to  500 
manganese;  then  introduci  through  thoT'^'^i'i"*^'*^   «^  th« 
chloric  acid  of  known  specificTmvitv  /  """'^  ^'  '^'"^  ^^^^^0- 
ing  nearly  20  per  cent,   of  chS^  <^"PP«f^  ^O,  contain- 
f^^a^i'^etrical  tube,  and  apply  Jen  ?el.!f/''T   *   *^^"&«* 
the   flask  by  placing  it  in  a  ^cfnsu  !  nf      /''  '^^  *^"«"  ^^ 
a  spira-lamp.    The%hlorine  evo  ved  In?''-  ''^"'""^  *>^«' 
the  tube/,  which   passes  merely  bpynnri  "'^  ."P  ^^"'"^^ 
enter  into  the  solution  in   b  and  /  "n   ^^^^«''f»  and  will 
sulphate.    Have  ready  some  drv  .    '  *^?"l«rting  it  into  red 
of  red    ferrocyanide    of   p"oJass?um  Tred"*'"'^ -^^'^   «*>^"^i«° 
Dip  a  slip   of  whalebone   into  X    r       P'^V^S'ate   of  iron). 
«irough   the  funnel  e  (represent^S  it^'ir'  «"   '^^  8^«»>«  ^» 
high   above  the  globe),  and   touch  ihp  ^^"^^  ™'^^^  ^«> 

As  long  as  it  forms  a  blue   snLt         ^  E^P^'  ^^^^  ^ts  point, 
as  black  oxide,  and  the  ^roe^ss  Tto  bV'  "7.^'"  "^«^» 
dition  of  a  little  more  hydrochloW.  »  ^^  "'^^'^   ^^^  ^^^^   ^^' 
?s  long  as  chlorine  gas  coni'nuei  to  K  '^-  ^°  ^^^  "manganese. 
It   maintains  the  level  of  the   Li^nr   • '^'''"^.^^^**'  *"^  ^^^le 
Whenever  the  liquor,  by  the  ri^t^       '  r  1  *^^^^  ^at  in  b. 
to  stain  the  test-paper  blue!  morl  of  ?hV'%^^^""'15>  ceases 
graduated  tube  must  be  added   till  it  k     •'''^"*''*".  ^'^°'°   ^^e 
the  cautious  administration  of  thii,^^^^^?'  ^^  *^«  so-    By 
one  hand,  and  of  the  cTp^r^i  litor^/^',^.^""'  ""''^  «"  '^^ 
of  saturation  will   be  aiWvS  at  ?n   ."r*^^  other,  the  term 
nianganese  has  then  produIS  Til  L     ^f"-  "'""^^«-      The 
yield.     The  number  of  water^.n        *=^^orine  which  it  can 

of  taking.  100^,^;n«    7   '^^  ^'*^'"  measures  of  liquid  and  1'    ^  consume  about  169 
.aPfroif  !?'^'**^^«  «^°^  has  probably  arisen  fm  '"o^banum.  and  to  very  nearly  40  graiS 


^ 


ALKALIMETRY. 


will  generate  as  much  chlorine  as  will  peroxidize  exactly  1,000  grain 
deerees  by  the  test-tube  of  the  copperas  solution.      But  if  the  ma 


measures,  or  100 
manganese   contain 
iiirio  oVsO  per  cent,  of  peroxide,  then  40  or  50  centigrade  measures  of  the  said 
Bolution  will  be  equivalent  to  the  chlorine  evolved  from  it  by  the  reaction  of  hydro- 

''''if'the^obtect  is  on  the  other  hand  to  obtain  direct  indications  as  to  cAZonne  then  a 
test  solution  of  copperas,  containing  772  grains  in  10,000  gram  measures,  w.  11  serve 
to  show  by  the  peroxidizement  of  each  10  gram  measures,  or  of  one  degree  of  the  cen- 
testimal  scale  of  the  test-tube,  the  reaction  of  one  gram  of  chlorine  available  for 
bleadi!^,  &c.,  in  the  chloride  of  lime  or  of  soda,  &c.  The  test  solutions  of  copperas 
Bhould  be  kept  in  well-corked  bottles,  containing  a  little  powdered  sulphuret  of  iron  at 
their  bottom,  which  is  to  be  shaken  up  occasionally  in  order  to  preserve  the  iron  in  the 

*^The  mlnga^nese  should  always  be  treated  with  dilute  nitric  acid  before  submitting  it 
to  the  above-described  ordeal;  and  if  it  exhibits  effervescence,  100  grains  of  it  should 
be  digested  with  the  acid  for  a  suflicient  time  to  dissolve  out  all  the  carbonates  present, 
then  thrown  upon  a  filter,  washed  and  dried  before  weighing  it  for  the  testing  opera- 
tion  The  loss  of  weight  thereby  sustained  denotes  the  per-centage  of  carbonates,  and 
if  calcareous  it  will  measure  the  waste  of  acid  that  would  ensue  from  that  source  alone, 
in  using  that  manganese  for  the  production  of  chlorine. 

That  manganese  is  most  chlorogerwus  which  contains  no  carbonates,  the  least  pro- 
portion of  oxide  of  iron,  and  of  sesquioxide  of  manganese. 

The  plan  of  testing  manganese  with  oxalic  and  sulphuric  t  cids  was  originally  prac- 
tised by  M.  Berthier  and  Dr.  Thomson,  but  is  lately  modified  by  Drs.  Fresemus  and 
Will,  who  employ  oxalate  of  potash,  as  likely  to  aflTord  more  exact  results.  Thev  pre- 
scribe  a  multiple  by  3  of  993  milli-grammes  =  2-979  grammes,  as  the  quantity  of 
manganese  best  adapted  to  experiment ;  but  this  quantity  will  not  be  found  convenient 

by  ordinary  British  operators.  .  »  i. 

I,  therefore,  take  leave  to  prescribe  the  following  proportions :  Into  the  vessel  a 
of  my  twin-globe  apparatus  (fig.  8),  put  100  grains  of  the  ground  manganese  under 
trial,  along  with  250  grains  of  oxalate  of  potash  and  a  little  water ;  poise  the  whole  la 
the  scale  of  a  balance;  then,  by  gentle  inclination,  cause  a  little  of  the  strong  sulphuric 
acid  to  pass  from  b  up  into  a.  The  oxygen  thereby  liberated  from  the  manganese, 
reacting  in  its  nascent  state  upon  the  oxalic  acid,  will  convert  it  into  carbonic  acid  gas ; 
which,  in  passing  through  b,  will  deposite  its  moisture  before  escaping  into  the  air. 
Whenever  the  extrication  ofgas  ceases,  after  such  a  quantity  of  oil  of  vitriol  has  been 
introduced  into  the  globe  a,  as  both  to  complete  the  decomposition  of  the  oxalic  acid 
and  to  heat  the  mixture,  withdraw  the  cork  for  a  moment,  to  replace  the  carbonic  acid 
with  air,  then  cool,  and  weigh  the  apparatus.  The  loss  of  weight,  in  grains,  will 
denote  the  per-centage  value  of  the  manganese;  that  is,  the  proportion  per  cent, 
of  perfect  peroxide  in  the  sample.  If  the  manganese  be  pure  no  black  powder  should 
remain. 

The  preceding  experiment  is  founded  upon  the  following  principle :  One  atom  of 
peroxide  of  manganese  =  44,  contains  one  atom  of  oxygen  separable  by  sulphuric  acid, 
and  capable  of  converting  one  atom  of  oxalic  acid  into  two  atoms  of  carbonic  acid, 
also  =  44,  which  fly  oflT;  and  cause  therefore  a  loss  of  weight  equal  to  that  of  the 
whole  peroxide.  To  one  atom  of  oxalic  acid,  which  consists  of  three  atoms  of  oxygen, 
and  two  of  carbon — if  one  atom  of  oxygen  be  added,  the  sum  is  obviously  four  atoms 
of  oxygen  and  two  of  carbon  =  2  atoms  of  carbonic  acid. 

The  apparatus  (fig.  10)  of  Drs.  Fresenius  and  Will  will  answer  perfectly  well  for 
making  the  same  experiment,  the  manganese  being  put  into  A,  with  about  two  and  a 
half  times  its  weight  of  oxalate  of  potash,  and  the  sulphuric  acid  being  drawn  over  into 
the  mixture  by  suction,  as  above  described. 

The  economy  of  any  sample  of  manganese  in  reference  to  its  consumption  of  acid,  in 
generating  a  given  quantity  of  chlorine,  may  be  ascertained  also  by  the  oxalic  acid 
test:  44  grains  of  the  pure  peroxide,  with  93  grains  of  neutral  oxalate  of  potash, 
and  98  of  oil  of  vitriol  disengage  44  grains  of  carbonic  acid,  and  afford  a  complete 
neutral  solution  ;  because  the  one  half  of  the  sulphuric  acid,  =  49  grains,  goes  to  form 
an  atom  of  sulphate  of  manganese,  and  the  other  half  to  form  an  atom  of  sulphate  of 
potash. 

The  deficiency  in  the  weight  of  carbonic  acid  thrown  off  will  show  the  deficiency  of 
peroxide  of  manganese ;  the  quantity  of  free  sulphuric  acid  may  be  measured  by  a  test 
solution  of  bicarbonate  of  potash,  and  the  quantity  neutralized,  compared  to  the  car 
bonic  gas  produced,  will  show,  by  the  ratio  of  98  to  44,  the  amount  of  acid  unprofitabl/ 
consumed. 


44 


ALKALIMETRY. 


ALKALIMETRY. 


45 


I 


.Ja  ^^\^'    ^^  *^^^'  ^>  ™*y  ^^0  ^  graduated,  and  may  contain  the  quantity  of 

orifice  S'open^.  °^  '""  '°''''''*'  '°  ^""^  °"''  '^  ^^  «^°P*^°^^  ^^  the  top 

th  J^'f.fn^*.! '';  ^''*?  *  ^"?^  *^  v""  ^^^'  ^'  ""^y  ^«  substituted  with  advantage  for 
enough  o?'Jj!i  T^  ^'  '^^'  '""^W^^y  ^l  °^«de  of  such  dimensions  as  to  contaTn 
ZnnJ^  -^^r"*  supersaturate  the  bases  of  the  carbonates  in  the  phial,  a,  there  will 
be  no  necessity  for  a  separate  vessel  to  hold  the  decomposing  acid.  Thus  the  apDaralus 
becomes  very  light,  convenient,  and  maybe  placed  in  the  s4ll  scale  of  a  fine  Cce 

Mock  ren'r  "''"f ''  '''''''  ^'''?^"^  ^"^  ^^"  <^^-  '^)^  '^  furnished  tMr! 
ft?ument  7.  r  ""^"^  large  pan  or  scale  to  stand  in.  I  flatte?  myself  that  the  in- 
fst?Tnd\-h^;  •!'  •.,  "^^"J,^^'^' ^»"  be  found  an  acceptable  present  lo  pracUcal  chem- 
^Inrno  /li  "k-^"^^^^^^^'"  readily  to  examine,  not  only  carbonates,  but  also 
manganese  and  bleaching  substances,  with  great  precision,  by  the  weight  of  carbonic 
acid  gas  disengaged,  on  the  principles  above  explained  caroonic 

«  «  }?ftl!?L^'\^^''M\^PP*'^^'i' .^•^^-  ^)'  *"^^  t^e  sulphuric  acid  is  poured  into 
lattei  R7th  ^  ^"^"^  ^.t  ^^'m?  ^^'^  ^'  ^'^^'^  ^^^  carbonate  is  introduced  into  the 
ihoked  ^y  crrSe'saU.'  "'^"^  '"'^^^  °'  ^'^  ^"^^  ^"^^  ^  ^"^  ^^  ^«  «Pt  to  get 

bv  Mr  ^uZJv^ ^"^t^t^o^Vl^^  ^'T  ^^  ^°'^  «^  ^"-  Fresenius  and  Will,  as  edited 
by  Mr.  Bullock  for  the  English  reader.    An  accurate  comparison  may  thus  be  made 

o?emors!-  "'''"'  ''''''''''  ^^"  "^^^"^^  ^''^  °^^^«  ^'  t^^  practke  of  ordSaPy 

to  "tJ^^7J.l'!J'^?V'A  Examimtum  of  Manganese :  having  at  the  same  time  due  regard 
to  the  amount  of  And  required  for  its  complete  Decomposition.— We  have  stated  ai 
Section  30,  that  it  is  not  a  matter  of  indifference,  with  regard  to  the  amounfof  ac?d 
employed  m  the  production  of  chlorine  from  manganese,  what  are  the  Tnerals  whfch 

of  ourmPth"'/  '°if '•"'  l^  ^^^^^^^^  with  the  peroxide.  The  following  i^r^fi^at  on 
of  our  method  will  g.ve  the  most  correct  information  on  this  point :- 


Specific  weight 
found. 


1-8485 

81-54 

1-8480 

81-13 

1-8475 

80-72 

1-8467 

80-31 

1-8460 

79-90 

1-8449 

79-49 

1-8439 

79-09 

1-8424 

78-68 

1-8410 

78-28 

1-8393 

77-84 

1-8376 

77-40 

1-8356 

77-02 

Per-centage 
amount  of 
anhydrous 
acid  found. 


Amount  to 
be  used  for 
the  exami- 
nation. 


6-708 
6-742 
6-776 
6-811 
•846 
•881 
-916 
•951 
-987 
•027 
7-067 
7-101 


Specific  weight 
found. 


6- 
6- 
6- 
6- 
6- 
7- 


1-8336 
1-8313 
1-8290 
1-8261 
1-8233 
1-8206 
1-8179 
1-8147 
1-8115 
1-8079 
1-8043 


Per-centage 
amount  of 
anhydrous 
acid  found. 


Amount  to 
be  used  for 
the  exami- 
nation. 


76-65 
76-24 
75-83 
75-42 
75-02 
74-61 
74-20 
73-79 
73-39 
72-97 
72-57 


•136 
•174 
•213 
•262 
•291 
•331 
-371 
•412 
7-453 
7-495 
7-537 


7- 
7^ 
7- 
7- 
7- 
7- 
7- 
7- 


«„,?lLr  f  f«  !  *J!^°  P°"'^^  into  A  as  will  fill  the  flask  to  about  one  fourth : 
and,  lastly,  from  6-5  to  7  grammes  of  neutral  oxalate  of  potash,  or  from  5-5  to  6 
grammes  of  neutral  oxalate  of  soda,  are  added;  2-98  grammes  of  the  (finely-pounded) 
manganese  to  be  examined  are  then  weighed  (the  manganese  must  have  been  pre- 
viously  tested  for  carbonate  alkaline  earths  :  compare  this  section  at  the  end)  into  a 
small  glass  tube,  such  as  used  in  acidimetry,  and  described  in  Section  25.  About  the 
aame  quantity  of  pure  pyrolusite,»  in  powder,  is  then  put  into  another  similar  tube. 
The  tube,  with  the  manganese  to  be  examined,  is  then  suspended  in  a  (M.  lOX  ai 
described  at  SecUon  26,  and  the  apparatus  prepared,  as  directed  at  Section  3.    The 

if  rt'onntLncIf  *^  °^  pyrolusite  will  serve  this  purpose,  provided  it  be  free  from  other  manganese  ores 
Lfr^IliT^^  '"f^^Vv.^Jf ;  '*  "jay  be  employed  directly  ;  but  should  it  contain  alumina  or  ifiSJ  it  musi 
^thpn  !,!  l"^  "^'^i^J*""!^  nitric  acd,  at  a  gentle  heat,  until  all  soluble  parts  have  been  diTsolve?   it 
for  pylorus  te'^'  ArtificiaUy  prepared,  hydratcd  pero.xide  of  mL^ganese  may  be  suitUutad 


apparatus  is  then  placed  on  one  scale  of  a  balance,  together  with  the  other  Uttle  tube 

^«'^htlork?frir^^^^^^^  LmeXt  raTsea  to  allow  the  little  tube  with  the  manganese 
"The  co^k  of  A  IS  ^^£?^°^^7^jjQ^  of  carbonic  acid  commences  immedia  ely,  and 
to  fall  into  ^^^.,^^^:.7^Zn^^^^^^  decomposed.  When  the  operation  begins  to  get 
continues  until  »  J^J^.^^^^^^f  ^jgXced  in  boiling  water,  and  allowed  to  remain  there 
on  more  slowly,  the  flask,  a,  is  placea  ;/J  |;"  |  ^  '^  ^  then  removed*  from  a,  the 
until  no  more  buf  es  aPPear  The  httle  ^a^  ~.-  ^^  ^  ^^,^  ^he  sucked  air 
flask,  A,  taken  out  of  the  ^^  J^^^J'/^^  ^^  ^  having  been  allowed  to  cool, 
astes  no  longer  of  carbomc  ac  a.     ^     JV  >  ^^^^  ^^^  ^.^^^^  ^^^^  ^.^^  ^^ 

\'  TJ'^n7er^^L    l^^^  for  the  loss  of  carbonic  acid.    The 

lusite  still  ^^^°^,^i^''^eg  required,  divided  by  three,  directly  indicates  the  per-centage 
«r,^nt  of  peroI'deTf  ml^^^^^^^^  ivide  Section  32  .  The  centigrammes  substituted 
?oTthe  Lss"^  of  carbonic  aci=d  are  then  removed  from  the  balance,  and  the  little  tube 

uu  1  ^frrncnlitP  is  throwu  luto  A.    (The  little  wax-stopper  must  of  course  pre- 
"^'^v  be^Kcedin%      ?f  no  ^  of  carbonic  acid  takes  place,  the 

mria'nese  exarned  c^^^^^^^  of  pure  pyrosulite,  and  the  experiment  is  at  an  end.  But 
Tnufd  a  fresh  evolution  of  carbonic  acid  take  place,  the  operation  must  be  further 
conducted  and  brought  to  a  close,  exactly  as  just  stated  {vide  supra).  The  apparatus 
L  then  replaced  on  the  balance,  with  an  additional  weight  of  three  grammes  on  the 
fame  scak  If  this  is  sufficient  to  restore  a  perfect  equilibrium,  no  oss  of  acid  has 
iaken  place;  L  manganese,  indeed,  contains  other  matters  in  admixture,  but  only 
S  as  do  not  consume  any  acid.  But  if  the  scale  with  the  apparatu.s  sinks,  this  is  a 
Srtain  sign  that  a  portion  of  the  acid  has  been  lost  by  combining  wi  h  the  oxides  which 
SemanTanese  under  examination  contains.  The  number  of  centigrammes  required 
S  rS^orl  the  perfect  equilibrium  of  the  balance,  multiplied  by  0-6114,  unmediately 
Lkates  how  much  anhydrous  sulphuric  acid  has  been  wasted  m  the  decomposition  of 
KK)  parts  of  the  manganese  under  examination.  The  same  number  multiplied  by 
a!333  indicates  the  amount  of  acid  wasted  in  every  100  parts  of  sulphuric  acid  em- 
ployed for  ?he  decomposition  of  the  manganese  in  question.  The  same  number,  multi. 
puJd  by  0-5552,  indicate  how  much  anhydrous  hydrochloric  acid  would  be  wasted  m 
Ihe  decomposition  of  100  parts  of  the  manganese.  The  same  number,  multiplied  by 
0  ^33,  indicates  also  how  much  acid  would  be  wasted  in  every  100  parts  of  hydrochloric 

acid  employed  for  the  decomposition  of  the  manganese. 

«  These  figures  result  from  the  following  equations :— 
«I.  275  (eqTof  carbonic  acid):  501  (eq.  of  sulphuric  acid)  =  the  carbonic  acid  ob- 
tained minus  (in  proportion  to  the  sulphuric  acid  used)  :  x. 

x=ihis  carbonic  acid  X  |0  J,  t.  e.  X  1*822. 

Thus,  the  number  obtained  for  x  indicates  the  amount  of  sulphuric  acid  corresponding 

to  the  amount  of  carbonic  acid  obtained  minus. 

« II.  2-98  of  manganese :  100=a:  of  equation  I. :  x. 
x=x  of  I.  X  Igf ,  i.  «.  X  0-33557. 
«  The  X  of  the  first  equation  tells  us  how  much  sulphuric  acid  has  been  wasted  without 

contributing  to  the  decomposition  of  2-98  grammes  of  the  manganese ;  the  x  of  the 

second  equation  tells  us  the  same  for  100  parts  of  manganese. 
« If  therefore,  the  amount  of  carbonic  acid  obtained  minus  be  directly  multiplied  by 

the  product  of  the  quotients  of  I.  and  II., 

^  1-822  and  0-33557, 

1.  e.  with  0-61141  (the  number  given  above),  the  amount  of  anhydrous  sulphuric  acid 

wasted  in  the  decomposition  of  every  100  parts  of  manganese  will  immediately  be 

found. 

"  III.  5-47  (the  amount  of  sulphuric  acid  used) : 
100=the  a:  of  I. :  x. 
x=thea:  of  I.  X  ij^,  i.  e.  X  0-18282. 
"Of  5-47  of  sulphuric  acid,  the  x  of  I.  has  been  wasted,  100  corresponds  to  the  x 

olTII.  .  ^       V     • 

"  The  X  of  ni.  is,  therefore,  found  directly  by  multiplying  the  amount  of  carbonic 
acid  obtained  minus  with  the  product  of  the  quotients,  1-822  and  0-18282,  i.  e.= 

0-33301.  ^  ^^    -  ,    , 

"The  figures  for  hydrochloric  acid  are  found  in  the  same  manner  (4'967  Dt  hydro- 
chloric acid  must  be  taken  instead  of  5-47  of  the  sulphuric  acid)."t 

*  ••  This  must  of  necessity  be  done  while  the  flask  is  still  standing  in  the  hot  water,  or  else  the  «ul« 
phurlc  acid  will  recede  upon  the  apparatus  being  removed  from  the  hot  water." 

t  Ntw  Methods  of  Alkalimetry,  and  of  determining  the  Commercial  Value  of  Acids  and  ManganeM. 
By  Drs.  C.  B.  FreseniuB  and  H  WUl.    Edited  by  J  Lloyd  Bullock :  pp.  123-128. 


46 


ALLOY. 


i    : 


h 


ground  and  mi^ed  with  a  &tll  IjJf JLt  ''  ^r^^*"'.  ^*"^'  garments,  &c.     The  leaves, 

and  Turkey.  *  ^"^'^  lin^ewater,  serve  for  dyeing  the  tails  of  horses  in  Persia 

.nd^...^/7he1^^C^^ 

the^pi;STf  c^n-s^^^^^^^^^^  7^:1'  tTenr ^T"^'  '^'  ^T^^''^'? 

n^L^onr  S^^^^^^^^^^^^  "sr^-^^-  ^^^  --« ^^-^ 

ofgJld^ali  s  i^^:?:itr;;^:^S^^  Thistermfonneny^-^iiiedaccinponnd 

of  any  two  or  more  me  als  whatSrer  Thl!T  "^^^  •"'  ^^'."  "^^  °^^*°«  ^^^  ^^'"PO""^ 
an  aUoy  of  copper  a^d  zL^  and  tvnp  m ''  ?™"^M'  an  alloy  of  copper  and  tin ;  brass, 
alloys  possess  metallic  lus^e  'even  whin  ^f.    '  T  f  ^^  °^  ^-'^^  ^°^  antimony.    All  the 

exceUent  conductors  of  h?at\ndeirctrTci^  II  f^"""  '1^''''  '^'^  ^'^  «P«^«^'  ^^^ 
are  more  or  less  ductile  3leahlpptc^5 '   /    ^•'^^'^ently  susceptible  of  crj^stallizing ; 

metals  different  yfusibkTsu^^^^^^^^^  '.f^T'*    ^"^  ^^^^  ^^^'^  *^«"«'«^  of 

emplified  with  brass  and  gonTmetd     '       '  '"  '*''  '"''^'  ""^  ^"^^^  ^^^"  ^«^'  ^  ^^  «' 

me&S  sretlWstt^U  P-Portions  of  the  simple  component 

sugar  with  Water  It  LnrobabL  fh^  II  T  P'^P^''^^^"'  ^^f  combinations  of  salt  or 
atomic  ratio,  as  is  exemDlified  in   L^^L^    ^^  ^^'rP'^'Pf!'^'  ^^^*^""  '«  ^'^^  equivalent  or 

One  metal  doesVoraZytndi^eenty^wT^^^^  m^L^  w'^  ^'^^  P'T-^^^"' 

respect  by  peculiar  affinities-  thnrXl  ^^ V  5,  "?^^*''  ^"'  *'  ^^  governed  in  this 
readily  with  go  Id,  copp^  and^ekd  Tn  ^  ^^r^^'y  J^^te  with  iron,  but  it  combines 
metals,  the  following dTff;rences  ^av  hi  nn^r  •""'  *^'  ^^^T  7''^  '^^'''  <^onstituent 
less  than  that  of  the  sepamte  LTall  L7l  '  !^  ^'"''^''  ^^'  ^""^"'^^  «^  ^^«  «"«y  « 
the  contrary,  the  al by  i^  Sly  hfrSl;  thanThTil^L"'  T  *.  ^""^  'TP^-^kable  degree;  on 
mercurial  alloys  or  aL^a^aL';^^^^^^^^^^^^  --^»*"-ts.  The 

Jet^mT^^^^^^^^^^^^^^ 

and  in  the  Ialter,TrecXr  of  tt "  r7^'  r  ^^'  ^""T"'  "^^^'  *"  approximation, 
union.  The  foUowin/tables  of  Wn«r!  Pf'^^'^^'^^f';?™  jach  other  in  the  act  of  their 
detail :-        '«"°^^n=  tables  of  bmary  aUoys  exhibit  this  circumstance  in  experimental 


ALLOY. 


47 


Alloy,  having:  a  den.ity  grreatcr  than  the 
mean  of  their  constiluenta. 

Gold  and  zinc 
Gold  and  tin 
Gold  and  bismuth 
Gold  and  antimony 
Gold  and  cobalt 
Silver  and  zinc 
Silver  and  lead 
Silver  and  tin 
Silver  and  bismuth 
Silver  and  antimony 
Copper  and  zinc 
Copper  and  tin 
Copper  and  palladium 
Copper  and  bismuth 
Lead  and  antimony 
Platinum  and  molybdinum 
Palladium  and  bismuth. 


Alloys  havini?  a  density  less  than  th« 
mean  of  their  constituents. 

Gold  and  silver 

Gold  and  iron 

Gold  and  lead 

Grold  and  copper 

Gold  and  iridium 

Gold  and  nickel 

Silver  and  copper 

Silver  and  lead 

Iron  and  bismuth 

Iron  and  antimony 

Iron  and  lead 

Tin  and  lead 
Tin  and  palladium 
Tin  and  antimony 
Nickel  and  arsenic 
Zinc  and  antimony. 


i  J^rthu^nt' mii::tirb^^^^^  r^'tv^i  TJits!  ^'  •'^  ^"^^  ^r^*^^^  ^'  -^^  «^ 

nity  in  their  state  of  combination  Of  Ih^  fusibility  is  increased  by  mutual  affi- 
fusible  metal  consistin-Ts  n^  s  of  bV/  /k'  k  J^^^^^^^^le  instance  is  afforded  in  the 
heat  of  boiling  wafer  or  212°  Falthnrh^K^  ""^  l'-^^^  *"^  ^  «^^»"'  ^^^^  ^^^^  at  th.. 
its  components  ThouW  be  SM'     Th'-     ^^"^  ^^^  ?^^^'"^  ^"^^  ^^"'^ed  from  the  mean  of 

a  ver>.irtrrct;lt  when  Tf^r^^^nTxL  LT  ma^H^"/^  "^°T  ^""^^"^  ''  ^'^^ 
jections,  and  for  filling  Ih'e  hollows  of  Ss  S      C  d?^^  '"" 

m  any  considerable  degree,  upon  those  ofZ  X;JZ'^:-Ztl^^^^^^ 


instead  of  being  rendered  paler  by  a  large  addition  of  zinc,  is  thereby  converted  into  the 

rich-looking  pinchbeck  metal.  ,  /.        ^  .  ,         j 

By  means  of  alloys,  we  multiply,  as  it  were,  the  numbers  of  useful  metals,  and  some- 
times give  usefulness  to  such  as  are  separately  of  little  value.  Since  these  compounda 
can  be  formed  only  by  fusion,  and  since  many  metals  are  apt  to  oxydize  readily  at  their 
melting  temperature,  proper  precautions  must  be  taken  in  making  alloys  to  prevent  this 
occurrence,  which  is  incompatible  with  their  formation.  Thus,  in  combining  tin  and  lead, 
rosin  or  grease  is  usually  put  on  the  surface  of  the  melting  metals,  the  carbon  produced 
by  the  decomposition  of  which  protects  them,  in  most  cases,  sufficiently  from  oxydizement. 
When  we  wish  to  combine  tin  with  iron,  as  in  the  tinning  of  cast-iron  tea  kettles,  we 
rub  sal  ammoniac  upon  the  surfaces  of  the  hot  metals  in  contact  with  each  other,  and 
thus  exclude  the  atmospheric  oxygen  by  means  of  its  fumes.  AVhen  there  is  a  notable 
difference  in  the  specific  gravities  of  the  metals  which  we  wish  to  combine,  we  often  find 
great  difficulties  in  obtaining  homogeneous  alloys ;  for  each  metal  may  tend  to  assume 
the  level  due  to  its  density,  as  is  remarkably  exemplified  in  alloys  of  gold  and  silver 
made  without  adequate  stirring  of  the  melting  metals.  If  the  mass  be  large,  and  slow 
of  cooling,  after  it  is  cast  in  an  upright  cylindrical  form,  the  metals  sometimes  separate, 
to  a  certain  degree,  in  the  order  of  their  densities.  Thus,  in  casting  large  bells  and 
cannons  with  copper  alloys,  the  bottom  of  the  casting  is  apt  to  contain  too  much  copper  and 
the  top  too  much  tin,  unless  very  dexterous  manipulation  in  mixing  the  fused  materials 
have  been  employed  immediately  before  the  instant  of  pouring  out  the  melted  mass. 
When  such  inequalities  are  observed,  the  objects  are  broken  and  re-melted,  after  which 
they  form  a  much  more  homogeneous  alloy.  This  artifice  of  a  double  melting  is  often 
had  recourse  to,  and  especially  in  casting  the  alloys  for  the  specula  of  telescopes. 

When  we  wish  to  alloy  three  or  more  metals,  we  often  experience  difficulties,  either 
because  one  of  the  metals  is  more  oxydable,  or  denser,  or  more  fusible,  than  the  others, 
or  because  there  is  no  direct  affinity  between  two  of  the  metals.  In  the  latter  predica- 
ment, we  shall  succeed  better  by  combining  the  three  metals,  first  in  pairs,  for  example, 
and  then  melting  the  two  pairs  together.  Thus,  it  is  difficult  to  unite  iron  with  bronze 
directly ;  but  if,  instead  of  iron,  we  use  tin  plate,  we  shall  immediately  succeed,  and  the 
bronze,  in  this  manner,  acquires  valuable  qualities  from  the  iron.  Thus,  also,  to  render 
brass  better  adapted  for  certain  purposes,  a  small  quantity  of  lead  ought  to  be  added  to 
it,  but  this  cannot  be  done  directly  with  advantage :  it  is  better  to  melt  the  lead  first 
along  with  the  zinc,  and  then  to  add  this  alloy  to  the  melting  copper,  or  the  copper  to 
that  alloy,  and  fuse  them  together. 

We  have  said  that  the  difference  of  fusibility  was  often  an  obstacle  to  metallic  com- 
bination ;  but  this  circumstance  may  also  be  turned  to  advantage  in  decomposing  certain 
alloys  by  the  process  called  eliquation.  By  this  means  silver  may  be  separated  from 
copper,  if  a  considerable  quantity  of  lead  be  first  alloyed  with  the  said  copper ;  this 
alloy  is  next  exposed  to  a  heat  just  sufficient  to  melt  the  lead,  which  then  sweats  out,  so 
to  speak,  from  the  pores  of  the  copper,  and  carries  along  with  it  the  greater  part  of  the 
silver,  for  which  it  has  a  strong  affinity.  The  lead  and  the  silver  are  afterwards  sepa- 
rated from  each  other,  in  virtue  of  their  very  different  oxydability,  by  the  action  of 
heat  and  air. 

One  of  the  alloys  most  useful  to  the  arts  is  brass ;  it  is  more  ductile  and  less  easily 
oxydized  than  even  its  copper  constituent,  notwithstanding  the  opposite  nature  of  the 
zinc.  This  alloy  may  exist  in  many  different  proportions,  under  which  it  has  different 
names,  as  tombac,  similor,  pinchbeck,  &c.  Copper  and  tin  form,  also,  a  compound  of 
remarkable  utility,  known  under  the  names  of  hard  brass,  for  the  bushes,  steps,  and 
bearings  of  the  axles,  arbors,  and  spindles  in  machinery  ;  and  of  bronze,  bell-metal,  &c. 
Gold  and  silver,  in  their  pure  state,  are  too  soft  and  flexible  to  form  either  vessels  or 
coins  of  sufficient  strength  and  durability ;  but  when  alloyed  with  a  little  copper,  they  ac- 
quire the  requisite  hardness  and  stiffness  for  these  and  other  purposes. 

When  we  have  occasion  to  unite  several  pieces  of  the  same  or  of  different  metals,  we 
employ  the  process  called  solderingy  which  consists  in  fixing  together  the  surfaces  by 
means  of  an  interposed  alloy,  which  must  be  necessarily  more  fusible  than  the  metal  or 
metals  to  be  joined.  That  alloy  must  also  consist  of  metals  which  possess  a  strong 
affinity  for  the  substances  to  be  soldered  together.  Hence  each  metal  would  seem  to 
require  a  particular  kind  of  solder,  which  is,  to  a  certain  extent,  true.  Thus,  the  soldei 
for  gold  trinkets  and  plate  is  an  alloy  of  gold  and  silver,  or  gold  and  copper ;  that  of 
silver  trinkets,  is  an  alloy  of  silver  and  copper ;  that  of  copper  is  either  fine  tin,  for 
pieces  that  must  not  be  exposed  to  the  fire,  or  a  brassy  alloy  called  hard  solder,  of  which 
the  zinc  forms  a  considerable  proportion.  The  solder  of  lead  and  tinplate  is  an  alloy  of 
lead  and  tin,  and  that  of  tin  is  the  same  alloy  with  a  litUe  bismuth.  Tinning,  gilding, 
and  silvering  may  also  be  reckoned  a  species  of  alloys,  since  the  tin,  gold,  and  silver  are 
superficially  united  in  these  cases  to  other  metals. 

Metallic  alloys  possess  usually  more  tenacity  than  could  be  inferred  from  their  con- 


48 


ALLOY. 


ALLOY. 


4f 


ll 


!  i: 


ll 


Ktituents;  thus,  an  alloy  of  twelve  parts  of  lead  with  one  of  zinc  has  a  tenacity  double 
that  of  zinc.  Metallic  alloys  are  much  more  easily  oxydized  thau  the  separate  metals,  a 
phenomenon  which  may  be  ascribed  to  the  increase  of  affinity  for  oxygen  which  results 
from  the  tendency  of  the  one  of  the  oxydes  to  combine  with  the  other.  An  alloy  of  tin 
and  lead  heated  to  redness  takes  fire,  and  continues  to  burn  for  some  time  like  a  piece 
of  bad  turf. 

Every  alloy  is,  in  reference  to  the  arts  and  manufactures,  a  new  metal,  on  account  of 
its  chemical  and  physical  properties.  A  vast  field  here  remains  to  be  explored.  Not  above 
sixty  alloys  have  been  studied  by  the  chemists  out  of  many  hundred  which  may  be  made; 
and  of  these  very  few  have  yet  been  practically  employed.  Very  slight  modifications 
often  constitute  very  valuable  improvements  upon  metallic  bodies.  Thus,  the  brass  most 
esteemed  by  turners  at  the  lathe  contains  from  two  to  three  per  cent,  of  lead ;  but  such 
brass  does  not  work  well  under  the  hammer ;  and,  reciprocally,  the  brass  which  is  best 
under  the  hammer  is  too  tough  for  turning. 

That  metallic  alloys  tend  to  be  formed  in  definite  proportions  of  their  constituents  is 
clear  from  the  circumstance  that  the  native  gold  of  the  auriferous  sands  is  an  alloy  with 
silver,  in  the  ratios  of  1  atom  of  silver  united  to  4,  5, 6, 12  atoms  of  gold,  but  never  with 
a  fractional  part  of  an  atom.  Also,  in  making  an  amalgam  of  1  part  of  silver  with  12 
or  15  of  mercury,  and  afterwards  squeezing  the  mixture  through  chamois  leather,  the 
amalgam  separates  into  2  parts  :  one,  containing  a  small  proportion  of  silver  and  much 
mercury,  passes  through  the  skin  ;  and  the  other,  formed  of  1  of  silver  and  8  of  mercury, 
is  a  compound  in  definite  proportions,  which  crystallizes  readily,  and  remains  in  the  knot 
of  the  bag.  An  analogous  separation  takes  place  in  the  tinning  of  mirrors  ;  for  on  load- 
ing them  with  the  weights,  a  liquid  amalgam  of  tin  is  squeezed  out,  while  another  amal- 
gam remains  in  a  solid  form  composed  of  tin  and  mercury  in  uniform  atomic  proportions. 
But,  as  alloys  are  generally  soluble,  so  to  speak,  in  each  other,  this  definiieness  of  com- 
bination is  masked  and  disappears  in  most  cases. 

M.  Chaudet  has  made  some  experiments  on  the  means  of  detecting  the  metals  of 
alloys  by  the  cupelling  furnace,  and  they  promise  useful  applications.  The  testing 
depends  upon  the  appearances  exhibited  by  the  metals  and  their  alloys  when  heated  on  a 
cupel.  Pure  tin,  when  heated  this  way,  fuses,  becomes  of  a  grayish  black  color,  fumes 
a  little,  exhibits  incandescent  points  on  its  surface,  and  leaves  an  oxyde,  which,  when 
withdrawn  from  the  fire,  is  at  first  lemon-yellow,  but  when  cold,  white.  Antimony 
melts,  preserves  its  brilliancy,  fumes,  and  leaves  the  vessel  colored  lemon-yellow  when 
hot,  but  colorless  when  cold,  except  a  few  spots  of  a  rose  tint.  Zinc  burns  brilliantly, 
forming  a  cone  of  oxyde ;  and  the  oxyde,  much  increased  in  volume,  is,  when  hot,  green- 
ish, but  when  cold,  perfectly  white.  Bismuth  fumes,  becomes  covered  with  a  coat  of 
melted  oxyde,  part  of  which  sublimes,  and  the  rest  enters  the  pores  of  the  cupel ;  when 
cold,  the  cupel  is  of  a  fine  yellow  color,  with  spots  of  a  greenish  hue.  Lead  resembles 
bismuth  very  much ;  the  cold  cupel  is  of  a  lemon-yellow  color.  Copper  melts,  and  be- 
comes covered  with  a  coat  of  black  oxyde ;  sometimes  spots  of  a  rose  tint  remain  on  the 
cupel. 

Alloys.— Tin  75,  antimony  25,  melt,  become  covered  with  a  coat  of  black  oxyde, 
have  very  few  incandescent  points;  when  cold,  the  oxyde  is  nearly  black,  in  con- 
sequence of  the  action  of  the  antimony  :  a  -^qq  part  of  antimony  may  be  ascertained  in 
this  way  in  the  alloy.    An  alloy  of  antimony,  containing  tin,  leaves  oxyde  of  tin  in  the 

cupel :  a  jqq  part  of  tin  may  be  detected  in  this  way.  An  alloy  of  tin  and  zinc  gives  an 
oxyde  which,  while  hot,  is  of  a  green  tint,  and  resembles  philosophic  wool  in  appearance. 
An  alloy  containing  99  tin,  1  zinc,  did  not  present  the  incandescent  points  of  pure  tin, 
and  gave  an  oxyde  of  greenish  tint  when  cold.  Tin  95,  bismuth  5  parts,  gave  an  oxyde 
of  a  gray  color.  Tin  and  lead  give  an  oxyde  of  a  rusty  brown  color.  An  alloy  of  lead 
and  tin,  containing  only  1  per  cent,  of  the  latter  metal,  when  heated,  does  not  expose  a 
clean  surface,  like  lead,  but  is  covered  at  times  with  oxyde  of  tin.  Tin  75,  and  copper 
25,  did  not  melt,  gave  a  black  oxyde  :  if  the  heat  be  much  elevated,  the  under  part  of 
the  oxyde  is  white,  and  is  oxyde  of  tin  ;  the  upper  is  black,  and  comes  from  the  copper. 
The  cupel  becomes  of  a  rose  color.  If  the  tin  be  impure  from  iron,  the  oxyde  produced 
by  it  is  marked  with  spots  of  a  rust  color. 

The  degree  of  affinity  between  metals  may  be  in  some  measure  estimated  by  the 
greater  or  less  facfity  with  which,  when  of  different  degrees  of  fusibility  or  volatility, 
they  unite,  or  with  which  they  can,  after  union,  be  separated  by  heat.  The  greater  or 
less  tendency  to  separate  into  difl'erently  proportioned  alloys,  by  long-continued  fusion, 
may  also  give  some  information  upon  the  subject.  Mr.  Hatchett  remarked,  in  his 
elaborate  researches  on  metallic  alloys,  that  gold  made  standard  with  the  usual  precaul 
tions,  by  silver,  copper,  lead,  antimony,  &c.,  and  then  cast,  after  long  fusion,  into  vertica- 
bars,  was  by  no  means  a  uniform  compound ;  but  that  the  top  of  the  bar,  corresponding 
to  the  metal  at  the  bottom  of  the  crucible,  contained  the  larger  proportion  of  gold. 
Hence,  for  a  more  thorough  combination,  two  red-hot  crucibles  should  be  employed,  and 
the  liquefied  metals  should  be  alternately  poured  from  the  one  into  the  other.    To  pre- 


vent unnecessary  oxidisement  from  the  air,  the  crucibles  should  contain,  besides  the 
metal,  a  mixture  of  common  salt  and  pounded  charcoal.  The  metallic  alloy  should 
also  be  occasionally  stirred  up  with  a  rod  of  pottery  ware. 

The  most  direct  evidence  ol  a  chemical  change  having  been  effected  in  alloys  i% 
when  the  compound  melts  at  a  lower  temperature  than  the  mean  of  its  ingredient*. 
Iron,  which  is  nearly  infusible,  acquires  almost  the  fusibility  of  gold  when  alloyed  with 
this  precious  metal.  The  analogy  is  here  strong  with  the  increase  of  solubility  which 
salts  acquire  by  mixture,  as  is  exemplified  in  the  difficulty  of  crystallizing  residuums 
of  saline  solutions,  or  mother  waters,  as  they  are  called. 

When  there  is  a  strong  affinity  between  the  two  metals,  their  alloy  is  generally 
denser  than  the  mean,  and  vice  versd.  This  is  exemplified  in  the  alloys  of  copper  with 
zinc  and  tin  on  the  one  hand ;  and  with  copper  and  lead  on  the  other.  When  one 
of  the  metals  is  added  in  excess,  there  'result  an  atomic  compound  and  an  indefinite 
combination,  as  would  appear  from  Muschenbroek's  experiments.     Thus, 

1  of  lead  with  4  of  silver  give  a  density  of  10"480. 
1  do         2  do  11-032. 

1  do        3  do  10-831. 

The  proportion  of  the  constituents  is  on  this  principle  estimated  in  France  by  the  tea 
of  the  ball  applied  to  pewter ;  in  which  the  weight  of  the  alloyed  ball  is  compared  with 
that  of  a  ball  of  pure  tin  or  standard  pewter  cast  in  the  same  mould.  Alloys  posseee 
the  elasticity  belonging  to  the  mean  of  their  constituents,  and  also  the  specific  caloric 
According  to  M.  Rudberg,  while  lead  solidifies  at  325°  C,  and  tin  at  228°,  and  their 
atomic  alloy  at  187°,  which  he  calls  the  fixed  point,  for  a  compound  Pb  Sns. 

The  action  of  the  air  is  in  general  less  on  alloys  than  on  their  components ;  to  which, 
however,  there  are  remarkable  exceptions,  as  for  example,  with  the  alloy  of  3  parts  of 
lead  and  1  of  tin,  which  when  heated  to  redness  burns  briskly  into  a  red  oxide.  When 
two  metals,  as  copper  and  tin,  are  combined,  which  oxidize  at  different  temperatures, 
they  may  be  separated  by  fusion  with  exposure  to  the  air,  an  artifice  practised  on 
the  church  bells  in  France  to  procure  tin  for  making  cannon  metal  bronze.  Cupella- 
tion  of  the  precious  metals  is  a  like  phenomenon. 

An  alloy  too  slowly  cooled  is  often  apt  to  favor  the  crystallization  of  one  or  more 
of  its  components,  and  thus  to  render  it  brittle  ;  and  hence  an  iron  mould  is  prefer- 
able to  one  of  sand  when  there  is  danger  of  such  a  result 

It  is  not  a  matter  of  indifference  in  what  order  the  metals  are  melted  together  in 
making  an  allo}^  Thus,  if  we  combine  90  parts  of  tin  and  10  of  copper,  and  to  this 
alloy  add  10  of  antimony;  or  if  we  combine  10  parts  of  antimony  with  10  of  copper 
and  add  to  that  alloy  90  parts  of  tin,  we  shall  have  two  allovs  chemically  the  same' 
and  still  It  will  be  easy  to  discover  that,  in  other  respects,  fusibility,  tenacity  Ac' 
they  totally  differ.  Whence  this  result  ?  Obviousl v  from  the  nature  of  their  combi- 
nation dependent  upon  the  order  pui-sued  in  the  preparation,  and  which  continues 
after  the  mixture.  In  the  alloys  of  lead  and  antimony  also,  if  the  heat  be  raised  in 
combininj;  the  two  metals  together  much  above  their  fusing  points,  the  alloy  become* 
harsh  and  brittle;  probably  because  some  alloy  formed  at  that  high  temperature  is 
not  soluble  in  the  mass.  ^ 

In  common  cases  the  specific  gravity  affords  a  good  criterion  whereby  to  judge  of  the 
proportion  of  two  metals  in  an  alloy.  But  a  very  fallacious  rule  has  been  given  in  some 
respectable  works  for  computing  the  specific  gravity  that  should  result  from  the  alloying 
of  given  quantities  of  two  metals  of  known  densities,  supposing  no  chemical  condensation 
or  expansion  of  volume  to  take  place.  Thus,  it  has  been  taught,  that  if  gold  and  copper 
be  united  m  equal  weights,  the  computed  specific  gravity  is  merely  the  arithmetical 
mean  between  the  numbers  denoting  the  two  specific  gravities.  Whereas  the  specific 
gravity  of  any  alloy  must  be  computed  by  dividing  the  sum  of  the  two  weights  by  the 
yum  of  the  two  volumes,  compared,  for  convenience  sake,  to  water  reckoned  unity.    Or, 

!II/"°^^'.  7\!.\'""^^'"^y.5^'^^^^^  thus  :-Multiply  the  sum  of  the  weights  into 
the  products  of  the  two  specific-gravity  numbers  for  a  numerator;  and  multiply  each 

fShl?'*''  !i"""°'^^'/"^°^ifu''"=^^  ^^  ^^^  «^^^^  body,  and  add  the  two  products 
together  for  a  denominator.     The  quotient  obtained  by  dividing  the  said  numerator  br 

n„r:nr''"!l"?w' f  ^  -^  truly  computcd  mean  specific  gravity  of  the  alloy.  On  com- 
paring with  that  density,  the  density  found  by  experiment,  we  shall  see  whether  expan- 
^npnJfi'/r^r  r^n£''''^?"'^^^'^"^''^^^**'^'"^tallic  Combination.  Gold  having  a 
specific  gravity  of  19-36,  and  copper  of  8-87,  when  they  are  alloyed  in  equal  weights,  give, 

by  the  fallacious  rule  of  the  arithmetical  mean  of  the  densities  ^9-36  +  8-87  _ 

^rZTthhrtf^J^^  computed  mean  density  is  only  12-16.  It  is  evident  that,  on  com- 
Sfious  condJn!"  •  ""^/^P^'^"^^"^  ^e  should  be  led  to  infer  that  there  h'ad  been  a 
prodigious  condensation  of  volume,  though  expansion  has  actuaUy  taken  place.    Lei 


\'\ 


1» 


50 


ALUM. 


ALUM. 


61 


W,  w  be  the  two  weights ;  P,  p  the  two  specific  gravities,  then  M,  the  mean  specific 
eravitv,  is  given  by  the  formula 

M-^-^^±^5lZP...2A  =  -i?^)=twice 
Pw-fpW  P  +  p 

the  error  of  the  arithmetical  mean ;  which  is  therefore  always  m  excess. 

Alloys  of  a  somewhat  complex  character  are  made  by  Mr.  Alexander  Parkes,  of 
Birmingham,  of  a  white  or  pale  color,  by  melting  together  33  i  lbs.  of  foreign  zinc,  64 
of  tin,  1^  of  iron,  and  3  of  copper ;  or  50  zinc,  48  tin,  1  iron,  and  3  copper ;  or  any  m- 
termediate  proportion  of  zinc  and  copper  may  be  used.  The  iron  and  copper  are  first 
melted  together  in  a  crucible,  the  tin  is  next  introduced,  in  such  quantities  at  a  time 
as  not  to  solidify  the  iron  and  copper ;  the  zinc  is  added  lastly,  and  the  whole  mixed 
by  stirring.  The  flux  recommended  for  this  alloy  is  1  part  of  lime,  1  part  of  Cumber- 
land (iron  ?)  ore,  and  3  parts  of  sal  ammoniac. 

Another  of  his  alloys  is  composed  of  66  lbs.  of  foreign  zinc,  33i  tin,  3^  antimony; 
or  70|  zinc,  I9J  tin,  and  2|  antimony;  or  any  intermediate  proportions,  and  with  or 
without  arsenic.  He  uses  black  flux.  When  to  be  applied  to  the  sheathing  of  ships, 
from  8  to  16  oz.  of  metallic  arsenic  are  added  to  every  100  lbs.  of  alloy.  A  third  class 
of  alloys  consists  of  equal  parts  of  iron  and  nickel ;  the  copper  is  next  added,  and  lastly 
the  zinc,  or  the  copper  and  zinc,  may  be  added  as  an  alloy.  100  lbs.  may  consist  of 
45i  lbs.  of  iron  and  nickel  (parten  cequalex),  and  lOJ  lbs.  of  foreign  zinc  ;  or  30|  lbs.  of 
alloy  of  iron  and  nickel  {p.  (b.\  46  copper,  and  26i  zinc  ;  or  any  intermediate  propor 
tions  of  zinc  and  copper.  He  uses  also  an  alloy  of  60  lbs.  of  copper,  20  of  zinc,  and  20 
of  silver;  or  60  copper,  10  nickel,  10  silver,  and  20  zinc;  the  copper  and  nickel  being 
first  fused  together.  His  fifth  alloy  is  called  by  him  a  non-conductor  of  heat !  It  is 
made  of  25  nickel,  25  iron,  and  50  copper;  or  15  nickel,  25  iron,  and  60  copper;  the 
last  being  added  after  the  fusion  of  the  others. 

Mr.  Parkes  also  proposes  to  deposit  metals  by  means  of  electricity  from  their  iodides, 
chlorides,  and  phosphates,  while  in  fusion  by  heat,  either  singly  or  combined  with 
compatible  haloids. 

ALMOND.  {Amande,Yr.;  Mandel,GeTm.)  There  are  two  kinds  of  almond  which 
do  not  differ  in  chemical  composition,  only  that  the  bitter,  by  a  curious  chemical  re- 
action of  its  constituents,  generates  in  the  act  of  distillation  a  quantity  of  a  volatile  oil, 
which  contains  hydrocyanic  acid.  Vogel  obtained  from  bitter  almonds  8*5  per  cent, 
of  husks.  After  pounding  the  kernels,  and  heating  them  to  coagulate  the  albumen,  he 
procured,  by  expression,  28  parts  of  an  unctuous  oil,  which  did  not  contain  the  smallest 
particle  of  hydrocyanic  acid.  The  whole  of  the  oil  could  not  be  extracted  in  this  way. 
The  expressed  mass,  treated  with  boiling  water,  afforded  sugar  and  gum,  and,  in  conse- 
quence of  the  heat,  some  of  that  acid.  The  sugar  constitutes  6*5  per  cent,  and  the  gum 
3.  The  vegetable  albumen  extracted,  by  means  of  caustic  potash,  amounted  to  30 
parts :  the  vegetable  fibre  to  only  5.  The  poisonous  aromatic  oil,  according  to  Robi 
quet  and  Boutron-Charlard,  does  not  exist  ready-formed  in  the  bitter  almond,  but 
seems  to  be  produced  under  the  influence  of  ebullition  with  water.  These  chemists 
have  shown  that  bitter  almonds  deprived  of  their  unctuous  oil  by  the  press,  when 
treated  first  by  alcohol,  and  then  by  water,  aff"ord  to  neither  of  these  liquids  any  vola- 
tile oil.  But  alcohof  dissolves  out  a  peculiar  white  crystalline  body,  without  smell,  of 
a  sweetish  taste  at  first,  and  afterwards  bitter,  to  which  they  gave  the  name  of  amyg- 
daline.  This  substance  does  not  seem  convertible  into  volatile  oil.  See  Amygdaunk. 
Sweet  almonds,  by  the  analysis  of  Boullay,  consist  of  54  parts  of  the  bland  alnriond 
oil,  6  of  uncrystallizable  sugar,  3  of  gum,  24  of  vegetable  albumen,  24  of  woody  fibre, 
5  of  husks,  35  of  water,  05  of  acetic  acid  including  loss.  We  thus  see  that  sweet 
almonds  contain  nearly  twice  as  much  oil  as  bitter  almonds  do. 

ALMOND  OIL.  A  bland  fixed  oil,  obtained  usually  from  bitter  almonds  by  the 
action  of  a  hydraulic  press,  either  in  the  cold,  or  aided  by  hot  iron  plates.     See  Oil. 

ALOE.  A  series  of  trials  has  been  made  within  a  few  years  at  Paris  to  ascertain 
the  comparative  strength  of  cables  made  of  hemp  and  of  the  aloe  from  Algiers  ;  and 
they  are  said  to  have  all  turned  to  the  advantage  of  the  aloe.  Of  cables  of  equal  size, 
that  made  of  aloe  raised  a  weight  of  2000  kilogrammes  (2  tons  nearly) ;  that  made  of 
hemp,  a  weight  of  only  400  kilogrammes.  At  the  exposition  of  objects  of  national  in- 
dustry, some  years  ago,  in  Brussels,  I  saw  aloe  cordage  placarded,  as  being  far  prefer- 
able to  hempen ;  but  I  believe  without  just  grounds. 

ALUDEL  A  pear-shaped  vessel  open  at  each  end,  of  which  a  series  are  joined  for 
distilling  mercury  in  Spain.     See  Meecuby. 

ALUM.  {Alun,  Fr. ;  Alaimi,  Germ.)  A  saline  body,  consisting  of  the  earth  of  clay, 
called  alumina  by  the  chemists,  combined  with  sulphuric  acid  and  potash,  or  sulphuric 
acid  and  ammonia,  into  a  triple  compound.  It  occurs  in  the  crystallized  form  of  octahe- 
drons, has  an  acerb  subacid  taste,  and  reddens  the  blue  color  of  litmus  or  red  cabbage. 


.Uum  works  existed  many  centuries  ago  at  Roccha,  formerly  called  Edessa,  m  Syria, 
whence  the  ancient  name  of  Roch  alum  given  to  this  salt.  It  was  afterwards  made  at 
Foya  Nova,  near  Smyrna,  and  in  the  neighborhood  of  Constantinople.  The  Genoese, 
and  other  trading  people  of  Italy,  imported  alum  from  these  places  into  western  Europe, 
for  the  use  of  the  dyers  of  red  cloth.  About  the  middle  of  the  fifteenth  centurj',  alum  began 
to  be  manufactured  at  La  Tolfa,  Viterbo,  and  Volaterra,  in  Italy ;  after  which  time  the 
importation  of  oriental  alum  was  prohibited  by  the  pope,  as  detrimental  to  tlie  interests 
of  hi*  dominions.  The  manufacture  of  this  salt  was  extended  to  Oermany  at  the  begin- 
ning of  the  sixteenth  century,  and  to  England  at  a  somewhat  later  period,  by  Sir 
Thomas  Chaloner,  in  the  reign  of  Elizabeth.  In  its  pure  state,  it  does  not  seem  to  have 
been  known  to  the  ancients ;  for  Pliny,  in  speaking  of  something  like  plumose  alum, 
says,  that  it  struck  a  black  color  with  pomegranate  juice,  which  shows  that  the  green 
vitriol  was  not  separated  from  it.  The  stypteria  of  Dioscorides,  and  the  alumen  of 
Pliny,  comprehended,  apparently,  a  variety  of  saline  substances,  of  which  sulphate  of 
iron,  as  well  as  alumina,  was  probably  a  constituent  part.  Pliny,  indeed,  says,  that  a 
substance  called  in  Greek  *Yypa,  or  watery,  probably  from  its  very  soluble  nature,  which 
was  milk-white,  was  used  for  dyeing  wool  of  bright  colors.  This  may  have  been  the 
mountain  butter  of  the  German  mineralogists,  which  is  a  native  sulphate  of  alumina,  of 
a  soft  texture,  waxy  lustre,  and  unctuous  to  the  touch. 

The  only  alum  manufactories  now  worked  in  Great  Britain,  are  those  of  Whitby,  in 
England,  and  of  Hiurlett  and  Campsie,  near  Glasgow,  in  Scotland ;  and  these  derive  the 
acid  and  earthy  constituents  of  the  salt  from  a  mineral  called  alum  slate.  This  mineral 
has  a  blueish  or  greenish-black  color,  emits  sulphurous  fumes  when  heated,  and  acquires 
thereby  an  aluminous  taste.  The  alum  manufactured  in  Great  Britain  contains  potash 
as  its  alkaline  constituent ;  that  made  in  France  contains,  commonly,  ammonia,  either 
alone,  or  with  variable  quantities  of  potash.  Alum  may  in  general  be  examined  by  water 
of  ammonia,  which  separates  from  its  watery  solutions  its  earthy  basis,  in  the  form  of  a 
light  flocculent  precipitate.  If  the  solution  be  dilute,  this  precipitate  will  float  long  as 
an  opalescent  cloud. 

If  we  dissolve  alum  in  20  parts  of  water,  and  drop  this  solution  slowly  into  water  or 
caustic  ammonia  till  this  be  nearly,  but  not  entirely,  saturated,  a  bulky  white  precipitate 
will  fall  down,  which,  when  properly  washed  with  water,  is  pure  aluminous  earth  or 
clay,  and  dried  forms  10-82  per  cent,  of  the  weight  of  the  alum.  If  this  earth,  while 
stdl  moist,  be  dissolved  in  dilute  sulphuric  acid,  it  will  constitute,  when  as  neutral 
as  possible,  the  sulphate  of  alumina,  which  requires  only  hvo  parts  of  cold  water  for  its 
solution.  If  we  now  decompose  this  solution,  by  pouring  into  it  water  of  ammonia, 
there  appears  an  insoluble  white  powder,  which  is  subsulphate  of  alumina,  or  basic  alum: 
and  contains  three  times  as  much  earth  as  exists  m  the  neutral  sulphate.  If,  however 
we  pour  into  the  solution  of  the  neutral  sulphate  of  alumina  a  solution  of  sulphate  of 
potash,  a  while  powder  wiU  fall  if  the  solutions  be  concentrated,  which  is  true  alum  :  but 
If  the  solutions  be  dilute,  by  evaporatmg  their  mixture,  and  cooUng  it,  cn-stals  of  alum 
will  be  obtained. 

When  newly  precipitated  alumina  is  boiled  in  a  solution  of  aliun,  a  portion  of  the 
eaith  enters  mto  combination  with  the  salt,  constituting  an  insoluble  compound,  whish 
foUs  in  the  form  of  a  white  powder.  The  same  combmation  takes  place,  if  we  decom- 
pose a  boilmg  hot  solution  of  alum  with  a  solution  of  potash,  till  the  mixture  appears 

^n^^tnTni  T  V*''°'"'  P^'P"'-  ..™'.  ^^^"^"^^^  ""^  ^^«i^  ^1"°^  ^^i«ts  native  in  the 
^Zh.  r^r  ^''^^  i'.Tn^v'''?*  ^^r^**'  ^"^  '^  ^«'^«i^ts  in  100  parts  of  19-72  parts  of 
Sn^in    k^  ^Tf'  61-99  basic  sulphate  of  alumina,  and  18.29  wat^.      When  this 

Z  the  cfrvSf.  h^^  *  ^r'  ^""'^'^'^r  of  sulphuric  acid,  it  dissolves,  and  is  converts! 
mto  the  crystallizable  alum  of  commerce. 

These  experimental  facts  develop  the  principles  of  the  manufacture  of  alum  which 
IS  prosecuted  under  various  modifications,  for  its  important  uses  in  the  arts  AlSn 
^Idom  occurs  ready-formed  in  nature;  occasionaUy,  as^an  efflorescence  on  stone';,  and^ 

rrf^Si^^lTv^TJ  ""?' "^ ,?  '^^.  ^^''  J^^^-  "^^^  ^"^  «f  European  commerce  is  fabricated 
artificiaUy,ei  her  from  the  alum  schists  or  stones,  or  from  clay.  The  mode  of  manufactur/' 
differs  accordmg  to  the  nature  of  these  earthy  compounds.     Some  of  them  such  asTe 

wSit  mlirh'r"  h"  %l  ^^T"^^  '^  '^'  ^^^^'  ^"^  ^^^  ^^h  othL  ma  ters  from 
Tame^v  Iv  «nH  if^.  The  schists  contain  only  the  elements  of  two  of  the  constituents, 
namely,  clay  ar^d  sulphur,  which  are  convertible  into  sulphate  of  alumina,  and  this  mav 

^um  It^^'  i"  V^^  ^7  ^^^^  '^^  ^^^^^^  ingredient.  To  this  class  belongTe 
alum-slates,  and  other  analogous  schists,  containing  brown  coal.  ^ 

fntL^'""'^^'  T  ""-^  *^^''''*  ■^''"''^  *^'  *^'"^"  Stone.~The  alum-stone  is  a  rare  mineral  being 

z^  wheretfolTe^Z'  t7°''''  %"' J  'T^^  ^  ""^^^^^^^  ^'  Bereghszasz,  ^d  Mus! 
r«v  t^  In.  •  •  T^^  ^^^  '"^  ^  ^^"^  substance,  partly  characterized  bv  numerous 
luTrL'.  *^r-  '"^  "^""7  crystallizations  of  alum-st^ne  or  basic  alum.  The  ^^^ 
lumps  contam  more  or  fewer  flints  disseminated  through  them,  and  ar;,  accordS^S 


!(< 


5S 


ALUM. 


ALUM. 


0t 


I 


I" 


their  auaUty,  either  picked  out  to  make  alum,  or  are  thrown  away.  The  sorted  piecej 
Srrols?^  or  Seined,  by  which  operation  apparenUy  the  hydrate  of  alumma,  associated 
^tirthe  sulphate  of  klmnina,  loses  its  water,  and,  as  burnt  clay,  loses  its  affi-tity  for 
S^/  Ittcomes,  therefore,  free ;  and  during  the  subsequent  exposure  to  the  weather 

TcSiriMcrwo;^^^^^^^^^  dlfalcati'on  in  the  product  of  alum.     For  this 

reas^nTe  contact  of  the  ignited  stones  with  carbonaceous  matter  ought  to  be  avoided 

The  calcS  ato-stones,  piled  in  heaps  from  2  to  3  feet  high,  are  to  be  exposed  to 
the  weathe^rnd  meanwh^  must  be  continually  kept  moist  by  sprmkhng  them 

with  water     As  the  water  combines  with  the  almn  the  stones  crumble  down  and  fall 
rventrily?into  a  pasty  mass,  which  must  be  lixiviated  with  warm  water,  and  allowed  to 
sltt?e  in  a  large  cistern.     The   clear  supernatant  liquor,  being  drawn   off,  must  be 
evapomted,  and  then  crystallized.    A  second  crystallization  finishes  the  Pro<=e^2i^«^  f"^' 
nlsh^  a  marketable  alum.     Thus  the  Roman  alum  is  made,  which  is  covered  with  a 

%'  'lut^^XL'r^^  Schist.-The  greater  portion  of  the  alum  found  in 

BrUishcommeS  made  from  alum-slate  and  analogous  minerak.     This  slate  contains 
mnrp  nrlf^ir^^^^  mixcd  with  coaly  or  bitumiuous  matter,  which  is  occasionally 

ZwaTt  asTr^S  Tem  somewhat  Combustible.  ^^ ^^^^^^l^lXTe^^^^ 
bituminous  wood,  where  the  upper  layers  lie  immediately  under  clay  beds,  they  consisx 
o^the  coaly  substlnce  render^  impure  with  clay  and  p>Tites.  This  triple  mixture 
cLstLtSL  essence  of  all  good  alum  schists,  and  it  operates  spontaneously  towards 
Se  Suet  on  of  sulphate  of  alumina.  The  coal  ser^'es  to  make  the  texture  open,  and 
oXw  the  air  and  moisture  to  penetrate  freely,  and  to  change  the  sulphur  and  iron  pre- 
s^nt  into  acid  and  oxyde.  When  these  schists  are  exposed  o  a  high  temperature  m 
Sntact^th  dr,  the  pyrites  loses  one  half  of  its  sulphur,  in  the  form  of  subl^ed 
Suror  sulphurous  acid,  and  becomes  a  black  sulphuret  of  iron,  which  speedily 
aSs  oxyger^^^^^  tosulphate  of  iron,  or  green  vitriol.     The  brown  coal  schists 

^S  Smmonly  some  green  vitriol  crystals,  spontaneously  f.  rmed  m  them.  The 
ZTxe  ofTon  tmnXs  Us  acid  to  the  clay,  progressively,  as  the  iron  by  the  action 
ont  air  witn l^Te  ek  becomes  peroxydized;  whereby  sulphate 

of  alumL  is  produced.  A  portion  of  the  green  vitriol  remains,  however  undecomposed, 
and  r^c^t^e  more  as  the^Tmay  happen  to  be  less  of  other  salifiable  bases  present  m 
?he  day  slate.  Should  a  little  magnesia  or  lime  be  present,  the  vitriol  gets  more 
completely  decomposed,  and  a  portion  of  Epsom  salt  and  gyi^um  is  produced. 

?he  manufactu?e  of  alum  from  almn  schLsts  may  be  distributed  under  the  sjx  foUo^g 
heads  —1  The  preparation  of  the  alum  slate.  2.  The  hxiviation  of  the  slate.  3.  The 
evapomtio;"^^^^^^^^^  4.  The  addition  of  the.saline  ingredients   or  the  pre- 

cipitation  of  the  alum.    5.   The  washing  of  the  almnmous  salts ;  and,  6.    The  crys^ 

"^f ""  Priarahon  of  the  Mum  S/a/e.-Some  alum  slates  are  of  such  a  nature  that, 
being  S  in  h^ps  in  the  open  air,  and  moistened  from  time  to  time  they  get  spon- 
toieouslv  ho?  and  by  degrees  foil  into  a  pulverulent  mass,  ready  to  be  lixiviated.  The 
SeX  part  however,  require  the  process  of  ustulation,  from  which  they  derive  many 
^vantages  '  TlTe  coVesiol  of  the  dense  slates  is  thereby  so  much  impaired  that  their  de- 
JornosS  becomes  more  rapid;  the  decomposition  of  the  pyrites  is  quickened  by  the 
T^^TorTZ?t^nof  the  sulphur;  and  the  ready-formed  green  vitriol  is  parti, 
deLmTosed  by  the  heat,  with  a  transference  of  its  sulphuric  acid  to  the  clay,  and 

^-"lu^ch^-L^f^^^^^^^^^^^  bitumen  or  coal  for  the  roasting  process  must  be 

interstratlfied  with  layers  of  smaU  coal  or  brushwood  over  an  extensive^^^^^^^^^     ^t 
Whitby  the  alum  rock,  broken  into  small  pieces,  is  laid  upon  a  ^onzontal  bed  ot  lael, 
romposed  of  brushwood;  but  at  Hurlett  small  coal  is  chiefly  used  fo^tbe  lower  bed 
When  about  four  feet  of  the  rock  is  piled  on,  fire  is  set  to  the  bottom  in  various  part^,  and 
whenever  the  mass  is  fairly  kindled,  more  rock  is  placed  over  the  top.    At  Wh uny  mis 
piling  process  is  continued  till  the  calcining  heap  is  raised  to  the  height  of  90  or  100  feet 
The  horizontal  area  is  also  augmented  at  the  same  time  till  it  forms  a  great  bed  nearly 
200  feet  square,  having  therefore  about  100,000  yards  of  solid  measurement.     Ihe  ra- 
pidity of  the  combusti^on  is  tempered  by  plastering  up  the  crevices  ^^th  sma^l  schist 
^oisLned.    When  such  an  immense  mass  is  inflamed  the  heat  is  sure  to  rise  too  h^gh 
and  an  immense  waste  of  sulphur  and  sulphuric  acid  must  ensue.     This  ev  I  has  been 
nSficed  auTwhitby  works.     At  Hurlett  the  height  to  which  the  heap  is  piled  is  only 
Tfew  feet,  while  the  horizontal  area  is  expanded;  which  is  a  much  more  judicmus  ar- 
rangement.  At  Whitby  130  tons  of  calcined  schist  produce  on  an  average  1  ton  of  alum. 


In  this  humid  climate  it  would  be  advisable  to  pile  up  on  the  top  of  the  horizontal  strata 
of  brushwood  or  coal,  and  schist,  a  pyramidal  mass  of  schist,  which  having  its  surface 
plastered  smooth,  with  only  a  few  air-holes,  will  protect  the  mass  from  the  rains,  and  at 
the  same  time  prevent  the  combustion  from  becoming  too  vehement.  Should  heavy  rams 
supervene,  a  gutter  must  be  scooped  out  round  the  pile  for  receiving  the  aluminous  lixi- 
vium, and  conducting  it  into  the  reservoir. 

It  may  be  observed,  that  certain  alum  schists  contain  abundance  of  combustible  matter, 
to  keep  up  a  suitable  calcining  heat  after  the  fire  is  once  kindled;  and  therefore  nothing 
is  needed  but  the  first  layer  of  brushwood,  which,  in  this  case,  may  be  laid  over  the  first 
bed  of  the  bituminous  schist. 

A  continual,  but  very  slow  heat,  with  a  smothered  fire,  is  most  beneficial  for  the 
ustulation  of  alum  slate.  When  the  fire  is  too  brisk,  the  sulphuret  of  iron  may  run 
with  the  earthy  matters  into  a  species  of  slag,  or  the  sulphur  will  be  dissipated  in  vapor, 
by  both  of  which  accidents  the  product  of  alum  will  be  impaired.  Those  bituminous 
alum  schists  which  have  been  used  as  fuel  under  steam  boilers  have  suffered  such  a 
violent  combustion  that  their  ashes  yield  almost  no  alum.  Even  the  best  regulated 
calciaing  piles  are  apt  to  burn  too  briskly  in  high  winds,  and  should  have  their  draught- 
holes  carefully  stopped  under  such  circumstances.  It  may  be  laid  down  as  a  general 
rule,  that  the  slower  the  combustion  the  richer  the  roasted  ore  will  be  in  sulphate  of 
alumina.  When  the  calcination  is  complete,  the  heap  diminishes  to  one  half  its  original 
bulk ;  it  is  covered  with  a  light  reddish  ash,  and  is  open  and  porous  in  the  interior,  so 
that  the  air  can  circulate  freely  throughout  the  mass.  To  favor  this  access  of  air,  the 
masses  should  not  be  too  lofty ;  and  in  dry  weather  a  little  water  should  be  occasionally 
sprinkled  on  them,  which,  by  dissolving  away  some  of  the  saline  matter,  will  make  the 
interior  more  open  to  the  atmosphere. 

When  the  calcined  mineral  becomes  thoroughly  cold,  we  may  proceed  to  the  lixiviation. 
But  as,  from  the  first  construction  of  the  piles  or  beds  till  their  complete  calcination, 
many  weeks,  or  even  months,  may  elapse,  care  ought  to  be  taken  to  provide  a  sufficient 
number  or  extent  of  them,  so  as  to  have  an  adequate  supply  of  material  for  carrying  on 
the  lixiviating  and  crystallizing  processes  during  the  course  of  the  year,  or  at  least  during 
the  severity  of  the  winter  season,  when  the  calcination  may  be  suspended,  and  the 
lixiviation  becomes  unsatisfactory.  The  beds  are  known  to  be  sufficiently  decomposed 
by  the  efflorescence  of  the  salt  which  appears  upon  the  stones,  from  the  strong  aluminous 
taste  of  the  ashes,  and  from  the  appropriate  chemical  test  of  lixiviating  an  aliquot  average 
portion  of  the  mass,  and  seeing  how  much  alum  it  will  yield  to  solution  of  muriate  or 
sulphate  of  fKitash. 

2.  The  Lixiviation. — ^The  lixiviation  is  best  performed  in  stone-built  cisterns  ;  those  ol 
wood,  however  strong  at  first,  are  soon  decomposed,  and  need  repairs.  They  ought  to  be 
erected  in  the  neighborhood  of  the  calcining  heaps,  to  save  the  labor  of  transport,  and  so  ar- 
ranged that  the  solutions  from  the  higher  cisterns  may  spontaneously  flow  into  the  lower. 
In  this  point  of  view,  a  sloping  terrace  is  the  best  situation  for  an  alum  work.  In  the 
lowest  part  of  this  terrace,  and  in  the  neighborhood  of  the  boiling-house,  there  ought 
to  be  two  or  more  large  deep  tanks,  for  holding  the  crude  lixivium,  and  they  should  be 
protected  from  the  rain  by  a  proper  shed.  Upon  a  somewhat  hisher  level  the  cisterns 
of  the  clear  lixivium  may  be  placed.  Into  the  highest  range  of  cisterns  the  calcined 
mineral  is  to  be  put,  taking  care  to  lay  the  largest  lumps  at  the  bottom,  and  to  cover 
them  with  lighter  ashes.  A  sufficient  quantity  of  water  is  now  to  be  run  over  it,  and 
allowed  to  rest  for  some  time.  The  lixivium  may  then  be  drawn  off,  by  a  stopcock 
connected  with  a  pipe  at  the  bottom  of  the  cistern,  and  run  into  another  cistern  at  a 
somewhat  lower  level.  Fresh  water  must  now  be  poured  on  the  partly  exhausted 
schist,  and  allowed  to  remain  for  a  sufficient  time.  This  lixivium,  being  weak,  should 
be  run  off  into  a  separate  tank.  In  some  cases  a  third  addition  of  fresh  water  may  be 
requisite,  and  the  weak  lixivium  which  is  drawn  off  may  be  reserved  for  a  fresh  portion 
ot  calcined  mineral.  In  order  to  save  evaporation,  it  is  always  requisite  to  strengthen  weak 
leys  by  employing  them  instead  of  water  for  fresh  portions  of  calcined  schist.  Upon  the 
ingenious  disposition  and  form  of  these  lixiviating  cisterns  much  of  the  economy  and  sac- 
cess  of  an  alum  work  depend.  The  hydrometer  should  be  always  used  to  determine  the 
degree  of  concentration  which  the  solutions  acquire. 

The  lixiviated  stone,  being  thus  exhausted  of  its  soluble  ingredients,  is  to  be  removed 
from  the  cisterns,  and  piled  up  in  a  heap  in  any  convenient  place,  where  it  may  be  left 
either  spontaneously  to  decompose,  or,  after  drying,  mav  be  subjected  to  another  calci- 
nation. 

The  density  of  the  solution  may  be  brought,  upon  an  average,  up  to  the  sp.  gr.  of 
from  1-09  to  M5.  The  lat'.er  density  may  always  be  obtained  by  pumping  up  the  weak- 
cr  solutions  upon  fresh  calcined  mine.  This  strong  liquor  is  then  drawn  off,  when  the 
sulphate  of  lime,  the  oxyde  of  iron,  and  the  earths  are  deposited.  It  is  of  advantage  to 
leave  the  liquor  exposed  for  some  time,  whereby  the  green  vitriol  may  pass  into  a  per- 


I 


1 


ir 


1 

f 


64 


ALUM. 


sulphate  of  iron  with  the  deposition  of  §ome  oxyde,  while  the  liberated  acid  may  combine 
with  some  of  the  clay  present,  so  as  to  increase  the  quantity  of  sulphate  of  alumina. 
The  manufacture  of  alum  is  the  more  imperfect,  as  the  quantity  of  sulphate  of  iron  left 
tindecomposed  is  greater,  and  therefore  every  expedient  ought  to  be  tried  to  convert  the 
sulphate  of  iron  into  sulphate  of  alumina. 

3.  The  evaporation  of  the  Schist  Lixivium. — As  the  aluminous  liquors,  however 
well  settled  at  first,  are  apt,  on  the  great  scale,  to  deposite  earthy  matters  in  the  course 
of  their  concentration  by  heat,  they  are  best  evaporated  by  a  surface  fire,  such  as 
that  employed  at  Hurlett  and  Campsie.  A  water-tight  stone  cistern  must  be  built, 
having  a  layer  of  well  rammed  clay  behind  the  flags  or  tiles  which  line  its  bottom 
and  sides.  This  cistern  may  be  4  or  6  feet  wide,  2  or  3  feet  deep,  and  30  or  40 
feet  long,  and  it  is  covered  in  by  an  arch  of  stone  or  brickwork.  At  one  extremity  of 
this  tunnel,  or  covered  canal,  a  fire-grate  is  set,  and  at  the  other  a  lofty  chimney 
is  erecied.  The  cistern  being  filled  to  the  brim  with  the  alum  ley,  a  strong  fire  is 
kindled  in  the  reverberatory  grate,  and  the  flame  and  hot  air  are  forced  to  sweep  along 
the  surface  of  the  liquor,  so  as  to  keep  it  in  constant  ebullition,  and  to  carry  off*  the 
aqueous  parts  in  vapor.  The  soot  which  is  condensed  in  the  process  falls  to  the  bottom, 
and  leaves  the  body  of  the  liquor  clear.  As  the  concentration  goes  on,  more  of  the 
rough  lixivium  is  run  in  from  the  settling  cistern,  placed  on  a  somewhat  higher  level,  till 
the  whole  gets  charged  with  a  clear  liquor  of  a  specific  gravity  sufficiently  high  for  trans- 
ferring into  the  proper  lead  boilers. 

At  Whitby,  the  lead  pans  are  10  feet  long,  4  feet  9  inches  wide,  2  feet  2  inches  deep 
at  the  one  end,  and  2  feet  8  inches  deep  at  the  other.  This  increase  of  depth  and  cor- 
responding slope  facilitates  the  decantation  of  the  concentrated  lixivium  by  means  of 
a  syphon,  applied  at  the  lower  end.  The  bottom  of  the  pan  is  supported  by  a  series  of 
parallel  iron  bars,  placed  very  near  each  other.  In  these  lead  pans  the  liquor  is  concen- 
trated, at  a  brisk  boiling  heat,  by  means  of  the  flame  of  a  flue  beneath  them.  Every 
morning  the  pans  are  emptied  into  a  settling  cistern  of  stone  or  lead.  The  specific  gra- 
vity of  the  liquor  should  be  about  1*4  or  1*5,  being  a  saturated  solution  of  the  saline  mat- 
ters present.  The  proper  degree  of  density  must  vary,  however,  with  different  kinds  of 
lixivia,  and  according  to  the  different  views  of  the  manufacturer.  For  a  liquor  which 
consists  of  two  parts  of  sulphate  of  alumma,  and  one  part  of  sulphate  of  iron,  a  specific 
gravity  of  1*25  may  be  sufficient ;  but  for  a  solution  which  contains  two  parts  of  sulphate 
of  iron  to  one  of  sulphate  of  alumina,  so  that  the  green  vitriol  must  be  withdrawn  first  of 
all  by  crystallization,  a  specific  gravity  of  1*4  may  be  requisite. 

The  construction  of  an  evaporating  furnace  well  adapted  to  the  concentration  of  alu- 
minous and  other  crude  lixivia,  is  described  under  Soda.  The  liquor  basin  may  be  made 
of  tiles  or  flags  puddled  in  clay,  and  secured  at  the  seams  with  a  good  hydraulic  cement. 
A  mortar  made  of  quicklime  mixed  with  the  exhausted  schist  in  powder,  and  iron  turn- 
ings, is  said  to  answer  well  for  this  purpose.  Sometimes  over  the  reverberatory  furnace 
a  flat  pan  is  laid,  instead  of  the  arched  top,  into  which  the  crude  liquor  is  put  for  neu- 
tralization and  partial  concentration.  In  Germany,  such  a  pan  is  made  of  copper,  because 
iron  would  waste  too  fast,  and  lead  would  be  apt  to  melt.  From  this  preparation  basin 
the  under  evaporating  trough  is  gradually  supplied  with  hot  liquor.  At  one  side  of  this 
lower  trough  there  is  sometimes  a  door,  through  which  the  sediment  may  be  raked  out 
as  it  accumulates  upon  the  bottom.  Such  a  contrivance  is  convenient  for  this  mode  of 
evaporation,  and  it  permits,  also,  any  repairs  to  be  readily  made ;  but,  indeed,  an  appa* 
ratus  of  this  kind,  well  mounted  at  first,  will  serve  for  many  years. 

In  the  course  of  the  final  concentration  of  the  liquors,  it  is  customary  to  add  some  of 
the  mother  waters  of  a  former  process,  the  quantity  of  which  must  be  regulated  by  a 
proper  analysis  and  knowledge  of  their  contents.  If  these  mother  waters  contain  much 
free  sulphuric  acid,  from  the  peroxydation  of  their  sulphate  of  iron,  they  may  prove  useful 
in  dissolving  a  portion  of  the  alumina  of  the  sediment  which  is  always  present  in  greatei 
or  less  quantity. 

4.  The  precipitation  of  the  Mum  by  adding  ^Alkaline  Salts. — As  a  general  rule,  it  is 
most  advantageous  to  separate,  first  of  ail,  from  the  concentrated  clear  liquors,  the  alum 
in  the  state  of  powder  or  small  crystals,  by  addition  of  the  proper  alkaline  matter,  and 
to  leave  the  mingled  foreign  salts,  such  as  the  sulphate  of  iron  or  magnesia,  in  solution, 
instead  of  trying  to  abstract  these  salts  by  a  previous  crystallization.  In  this  way  we 
not  only  simplify  and  accelerate  the  manufacture  of  alum,  and  leave  the  mother  waters 
to  be  worked  up  at  any  convenient  season,  but  we  also  avoid  the  risk  of  withdrawing 
any  of  the  sulphate  of  alumina  with  the  sulphate  of  iron  or  magnesia.  On  this  account, 
the  concentration  of  the  liquor  ought  not  to  be  pushed  so  far  as  that,  when  it  gets  cold, 
it  should  throw  out  crj'stals,  but  merely  to  the  verge  of  this  point.  This  density  may  be 
determined  by  suitable  experiments. 
The  clear  liquor  should  now  be  run  oflf  into  the  precipitation  cistern,  and  have  the 


ALUM. 


6S 


proper  quantity  of  sulphate  or  muriate  of  potash,  or  impure  sulphate  or  carbonate  of 
ammonia  added  to  it.  The  sulphate  of  potash,  which  is  the  best  precipitant,  forms  18-34 
parts  out  of  100  of  crystallized  alum;  and  therefore  that  quantity  of  it,  or  its  equivalent 
in  muriate  of  potash,  or  other  potash  or  ammoniacal  salts,  must  be  introduced  into  the 
aluminous  liquor.  Since  sulphate  of  potash  takes  10  parts  of  cold  water  to  dissolve  it, 
but  is  much  more  soluble  in  boiling  water,  and  since  the  precipitation  of  alum  is  more 
abundant  the  more  concentrated  the  mingled  solutions  are,  it  would  be  prudent  to  add 
the  suIphAte  solution  as  hot  as  may  be  convenient ;  but,  as  muriate  of  potash  is  fully 
three  times  more  soluble  in  cold  water,  it  is  to  be  preferred  as  a  precipitant,  when  it  can 
be  procured  at  a  cheap  rate.  It  has,  also,  the  advantage  of  decomposing  the  sulphate  of 
iron  present  into  a  muriate,  a  salt  very  difficult  of  crystallization,  and,  therefore,  less 
apt  to  contaminate  the  crystals  of  alum.  The  quantity  of  alkaline  salts  requisite  to 
precipitate  the  alum,  in  a  granular  powder,  from  the  lixivium,  depends  on  their  rich- 
ness in  potash  or  ammonia,  on  the  one  hand,  and  on  the  richness  of  the  liquors  in 
sulphate  of  alumina  on  the  other ;  and  it  must  be  ascertained,  for  each  large  quantity  of 
product,  by  a  preliminary  experiment  in  a  precipitation  glass.  Here,  an  aliquot  measure 
of  the  aluminous  liquor  being  taken,  the  liquid  precipitant  must  be  added  in  successive 
portions,  as  long  as  it  causes  any  cloud,  when  the  quantity  added  will  be  indicated  by 
the  graduation  of  the  vessel.  A  very  exact  approximation  is  not  practicable  upon  the 
great  scale  ;  but,  as  the  mother  waters  are  afterwards  mixed  together  in  one  cistern,  any 
excess  of  the  precipitant,  at  one  time,  is  corrected  by  excess  of  aluminous  siilphate  at 
another,  and  the  resulting  alum  meal  is  collected  at  the  bottom.  When  the  precipitat- 
ed saline  powder  is  thoroughly  settled  and  cooled,  the  supernatant  mother  water  must 
be  drawn  off  by  a  pump,  or  rather  a  syphon  or  stopcock,  into  a  lower  cistern.  The 
more  completely  this  drainage  is  cflTected,  the  more  easily  and  completely  will  the  alum 
be  purified. 

This  mother  liquor  has,  generally,  a  specific  ffravity  of  1-4  at  a  medium  temperature 
of  the  atmosphere,  and  consists  of  a  satarated  solution  of  sulphate  or  muriate  of  black 
and  red  oxyde  of  iron,  with  sulphate  of  magnesia,  in  certain  localities,  and  muriate  of 
soda,  when  the  soaper's  salt  has  been  used  as  a  precipitant,  as  also  a  saturated  solution 
of  sulphate  of  alumina.  By  adding  some  of  it,  from  time  to  time,  to  the  fresh  lixivia,  a 
portion  of  that  sulphate  is  converted  into  alum ;  but,  eventually,  the  mother  water  must 
be  evaporated,  so  as  to  obtain  from  it  a  crop  of  ferruginous  crystals;  after  which  it  be- 
comes capable,  once  more,  of  giving  up  its  alum  to  the  alkaline  precipiianLs. 

When  the  aluminous  lixivia  contain  a  great  deal  of  sulphate  of  iron,  it  may  be  good 
poUcy  to  withdraw  a  portion  of  it  by  crystallization  before  precipitating  the  alum.  With 
this  view,  the  liquors  must  be  evaporated  to  the  density  of  1-4,  and  then  run  oflf  into 
crj'staiJizmg  stone  cisterns.  After  the  green  vitriol  has  concreted,  the  liquor  should  be 
pumped  back  mto  the  evaporating  pan,  and  again  brought  to  the  density  of  1'.4.  On 
aaamg  to  it,  now,  the  alkaline  precipitants,  the  alum  will  fall  down  from  this  concentrat- 
ed solution,  m  a  very  minute  crystalline  powder,  very  easy  to  wash  and  purify.  But  this 
method  requires  more  vessels  and  manipulation  than  the  preceding,  and  should  only  be 
fKo  Jrr^w  ^  ?  necessity;  since  it  compels  us  to  carry  on  the^  manufacture  of  both 

PT?rI^P<t  «t%  Tr^'^^l*'^  lower  priced  salts  at  the  same  time;  moreover,  the  copperas 
sulnhafe  of  il^^Jn™""  '5'  ''^  •''  liquors  carries  with  it,  as  we  have  said,  a  portion  of  the 
Tftor  ti!  f  alumina,  and  acquires  thereby  a  dull  aspect ;  whereas  the  copperas  obtained 
after  the  separation  of  the  alum  is  of  a  brilliant  appearance. 

mattPr  h«r»  K^''''*'1'*^'T'^'^-''  '^  ^/um  Pou;d€r.-This  crystalline  pulverulent 

Tmav  be  frP.^  r"''>  f^^""'  ['""^  '^^   admixture   of  the  ferriginous  liquors;  but 

IrLe  s^xteenfhTr'-.  ^^  "^^^^^^f  T^^  ^"^  *=°^^  Water,  which  dissolves  not  more 

weU  together  thif^^  weight  of  alum.     After  stirring  the  powder  and  the  water 

Tawn  off  A  ..InT'  ""il-''  ^'  f  °^^^  ^"^  '^"^^'  ^"^  ^hen  the  washing  must  be 
ill^  iA       T""^^  washing  will  render  the  alum  nearly  pure.     The  less   water 

pro^S  ^^Tie\"i  '\'   T'   *^^^J^"^^y  ''   ^'  ^^'^^^  «ff»  the'  mor;   complete   «   Se 
•l^^wd^r  in  r  X    nf""^^  ^  r"^  Sv'^"  ^''  ^^«hi"g  «f  *"other  portion  of  . 
iixiWa.  ^  ^'""^  ^*^^'*    ^^^'^  washings  may  be  added  to  the  schist 

watr^t'dT^nlvi^'^^'i'^TT^^  washed  alum  is  put  into  a  lead  pan,  with  just  enough 
^iSni  Whin  ^■^'  ^^"?  ^T^  •  ^'^  '^  *PP"^^>  '^"d  the  solution  is  pron.oted  by 
SfwhTch  arTn^n  J  ^T^^"^  'V  ^  '"i"'^'^  «^^^^' ''  ^«  "t*^  ofl"  into  the  Crystallizing 
wwTin  tip  mJHHi  ^  'T^'""^  '^'^'-  ^^^'^  '^^^'^s  ^'•e  ab«"t  five  feet  high,  three  feet 
niSy  fitted^  eichTh'''^^^"^^^^^^^  V^'  ^""^^ '  they  are  made  of  very  strong  staves, 
^Lv^  lo  Z^t^  '  """1^^^^  ^?^f^^'  ^y  ^*'"°'^?  i^°»  hoops,  which  are  driven  on 
JI^S  The  It  ^^  f?^  ^  -^'^i  ^"^'^^^  ^ff  ^^*>»'  i»  «^e'  to  take  the  staves 
Targe  reiullrci^s^^^^^^  ^ts  slow  cooling  in  these  close  vessels,  forms 

aXrLver  or  cSir..'f^^  hang  down  from  the  top,  and  project  from  the  sides/ while 
«  imck  layer  or  cake  lines  the  whole  mterior  of  the  cask.    At  the  end  of  eight  or  ten  days 


li 


'V 


I  f'. 


•' 


56 


ALUM. 


more  or  less,  acccording  to  the  weather,  the  hoops  and  staves  are  removed,  when  a  cask, 
of  apparently  solid  alum  is  disclosed  to  view.  The  workman  now  pierces  this  mass  with 
a  pickaxe  at  the  side  near  the  bottom,  and  allows  the  mother  water  of  the  interior  to  run 
off  on  the  sloping  stone  floor  into  a  proper  cistern,  whence  it  is  taken  and  added  to  another 
quantity  of  washed  powder  to  be  crystallized  with  it.  The  alum  is  next  broken  into 
lumps,  "exposed  in  a  proper  place  to  dry,  and  is  then  put  into  the  finished  bing  for  the 
market.  There  is  sometimes  a  little  insoluble  basic  alum  (subsulphate)  left  at  the  bottom 
of  the  cask.  This  being  mixed  with  the  former  mother  liquors,  gets  sulphuric  acid  from 
them  ;  or,  being  mixed  with  a  little  sulphuric  acid,  it  is  equally  converted  into  alum. 

When,  instead  of  potash  or  its  salts,  the  amrooniacal  salts  are  used,  or  putrid  urine, 
with  the  aluminous  lixivia,  ammoniacal  alum  is  produced,  which  is  perfectly  similar  to 
the  potash  alum  in  its  appearance  and  properties.  At  a  gentle  heat  both  lose  their  wa- 
ter of  crystallization,  amounting  to  45^  per  cent,  for  the  potash  alum,  and  48  for  the  am- 
moniacal. The  quantity  of  acid  is  the  same  in  both,  as,  also,  very  nearly  the  quantity  ot 
alumina,  as  the  following  analyses  will  show  : — 


Potash  alum. 
Sulphate  of  potash 
Sulphate  of  alumina 
Water  -        -        - 


18-34 
36-20 
45-46 

100-00 


Ammonia  alum. 
Sulphate  of  ammonia 
Sulphate  of  alumina 
Water      -        -        -        - 


Or  otherwise.  Potash  alum. 
1  atom  sulphate  of  potash    -  1089-07 
1  alumina    -  2149-80 

24  water  ...    -  2669-52 


Ammonia  alum. 
1  atom  sulphate  of  ammonia 
1  alumina 

24  water   -       -       -       - 


6938-39 


12-88 
38-64 

48-48 

100-00 


716-7 
2149-8 
2699-5 

5566-0 


Or,  Potash  alum. 

Ammonia  alum. 

Alumina         -        -        -        .    10-82 

Alumina          -        -        - 

-     11-90 

Potash            ...        -       9-94 

Ammonia         -        -        - 

-      3-89 

Sulphuric  acid         -        -         -    33-77 

Sulphuric  acid 

-    36-10 

Water 45-47 

Water     -        -        -        - 

-    48-11 

100-00 


100-00 


Wlien  heated  pretty  strongly,  the  ammoniacal  alum  loses  its  sulphuric  acid  and 
ammonia,  and  only  the  earth  remains.  This  is  a  very  convenient  process  for  procuring 
pure  alumina.  Ammoniacal  alum  is  easily  distinguished  from  the  other  by  the  smell  of 
ammonia  which  it  exhales  when  triturated  with  quicklime.  The  Roman  aluin,  made 
from  alum-stone,  possesses  most  of  the  properties  of  the  schist-made  alums,  bui  it  has  a 
few  peculiar  characters :  it  crystallizes  always  in  opaque  cubes,  whereas  the  common 
alum  crystallizes  in  transparent  octahedrons.  It  is  probable  that  Roman  alum  is  a 
sulphate  of  alumina  and  potash,  with  a  slight  excess  of  the  earthly  ingredient.  It  is 
permanent  when  dissolved  in  cold  water ;  for  after  a  slow  evaporation  it  is  recovered  in 
d  cubical  form.  But  when  it  is  dissolved  in  water  heated  to  110*  Fahr.  and  upwards,  oi 
when  its  solution  is  heated  above  this  pitch,  subsulphate  of  alumina  falls,  and  on 
evaporation  octahedral  crystals  of  common  alum  are  obtained.  The  exact  composition 
of  the  Roman  alum  has  not  been  determined,  as  far  as  I  know.  It  probably  differs 
ft  om  the  other  also  in  its  water  of  crystallization.  The  Roman  alum  contains,  according  to 
MM.  Thenard  and  Roard,  only  ^Jqq  of  sulphate  of  iron,  while  the  common  commercial 
alums  contain  roo'o-  ^^  ^^^  ^^  easily  purified  by  solution,  granulation,  crystallization,  and 
washing,  as  has  been  already  explained. 

Alum  is  made  extensively  in  France  from  an  artificial  sulphate  of  alumina.  For  thL§ 
purpose  clays  are  chosen  as  free  as  possible  from  carbonate  of  lime  and  oxyde  of  iron. 
They  are  calcined  in  a  reverberatory  furnace,  in  order  to  expel  the  water,  to  peroxydizc 
the  iron,  and  to  render  the  alumina  more  easily  acted  on  by  the  acid.  The  expulsion  of 
the  water  renders  the  clay  porous  and  capable  of  absorbing  the  sulphuric  acid  by 
capillary  attraction.  The  peroxydation  of  the  iron  renders  it  less  soluble  in  the 
TOlphuric  acid;  and  the  siljca  of  the  clay,  by  reacting  on  the  .ilumina,  impairs  its 
aggregation,  and  makes  it  more  readily  attracted  by  the  acid.    The  clay  shoiild,  therefore, 


ALUM. 


57 


be  moderately  calcined ;  but  not  so  as  to  indurate  it  like  pottery  ware,  for  it  would  then 
Ufler  a  species  of  silicious  combination  which  would  make  it  resist  the  action  of  acids. 
The  clay  is  usually  calcined  in  a  reverberatory  furnace,  the  flame  of  which  serves 
thereafter  to  heat  two  evaporating  pans  and  a  basin  for  containing  a  mixture  of  the 
calcined  clay  and  sulphuric  acid.  As  soon  as  the  clay  has  become  friable  in  the  furnace 
it  is  taken  out,  reduced  to  powder,  and  passed  through  a  fine  sieve.  With  100  parts  of 
the  pulverized  clay,  45  parts  of  sulphuric  acid,  of  sp.  gr.  1-45,  are  well  mixed,  in  a 
stone  basin,  arched  over  with  brickwork.  The  flame  and  hot  air  of  a  reverberatory 
furnace  are  made  to  play  along  the  mixture,  in  the  same  way  as  described  for  evaporating 
the  schist  liquors.  See  Soda.  The  mixture,  being  stirred  from  time  to  time,  is,  at  the 
end  of  a  few  days,  to  be  raked  out,  and  to  be  set  aside  in  a  warm  place,  for  the  acid  \o 
work  on  the  clay,  during  six  or  eight  weeks.  At  the  end  of  this  time  it  must  be  washed, 
to  extract  the  sulphate  of  alumina.  W^ith  this  view,  it  may  be  treated  like  the  roasted 
alum  ores  above  described.  If  potash  alum  is  to  be  formed,  this  sulphate  of  alumina  is 
evaporated  to  the  specific  gravity  of  1-38;  but  if  ammonia  alum,  to  the  specific  gravity 
of  only  1*24;  because  the  sulphate  of  ammonia,  being  soluble  in  twice  its  weight  of 
water,  will  cause  a  precipitation  of  pulverulent  alum  from  a  weaker  solution  of  sulphate 
of  alumina  than  the  less  soluble  sulphate  of  potash  could  do. 

The  alum  stone,  from  which   the   Roman   alum   is   made,  contains   potash.      The 
following  analysis  of  alunite,  by  M.  Cordier,  places  this  fact  in  a  clear  light : — 


Sulphate  of  potasn 
Sulphate  of  alumina 
Hydrate  of  alumina 


18-53 
38-50 
42-97 

100-00 


To  transform  this  compound  into  alum,  it  is  merely  necessary  to  abstract  the  hydrate 
of  alumina.  The  ordinary  alum  stone,  however,  is  rarely  so  pure  as  the  above  analysis 
would  seem  to  show ;  for  it  contains  a  mixture  of  other  substances ;  and  the  above  are  in 
diflierent  proportions. 

Alum  is  very  extensively  employed  in  the  arts,  most  particularly  in  dyeing,  lake 
making,  dressing  sheep-skins,  pasting  paper,  in  clarifying  liquors,  &,c.  Its  purity  for 
the  dyer  may  be  tested  by  prussiate  of  potash,  which  will  give  solution  of  alum  a  blue 
tint  in  a  few  minutes  if  it  contain  even  a  very  minute  portion  of  iron.  A  bit  of  nut-gall 
is  also  a  good  test  of  iron. 

Altuu  liquors. — In  the  alum,  works  on  the  Yorkshire  coast,  8  different  liquore  arc 
met  with. 

1st  "  Raw  Liquor."     The  calcined  alum  shale  is  steeped  in  water  till  the  liquor 
has  acquired  a  specific  gravity  of  9  or  10  pennyweights,  according  to  the  lan- 
guage of  the  alum-maker. 
2d.  "  Clarified  Liquor."     The  raw  liquor  is  brought  to  the  boiling  point  in  lead 
jians,  and  suffered  to  stand  in  a  cistern  till  it  has  cleared:  it  is  then  called  clari- 
fied liquor.     Its  gravity  is  raised  to  10  or  11  pennyweights. 
3d.  " Concentiated  Liquor."     Clarified  liquor  is  boiled  down  to  about  20  penny- 
weights.    This  is  kept  merely  as  a  test  of  the  comparative  value  of  the  potash 
salts  used  by  the  alum-maker. 
4th.  "  Alum  Mother  Liquor."     The  alum  pans  are  fed  with  clarified  liquor,  which 
is  boiled  down  to  about  25  or  30  pennyweights,  when  a  proper  quantity  of 
potash  salt  in  solution  is  mixed  with  it,  and  the  whole  run  into  coolers  to 
crystallize.     The  liquor  pumped  from  those  rough  crystals  is  called  "  alum 
mothers." 
6th.  "Salts  Mothers." 
and  afford  a  crop 
toxide  of  iron. 

6th  and  7th.  "Alum  Washings."  The  rough  crystals  of  Alum  (Xo.  4)  are  washed 
twice  in  water,  the  first  washing  being  atout  4  pennyweights,  the  second 
about  2i,  the  difference  in  gravity  being  due  to  mother  I'iquor  clinging  to  the 
crystals. 

8th.  "Tun  Liquor."    The  washed  crystals  are  now  dissolved  in  boiling  water,  and 
run  into  the  "roehing  tuns"  (wood  vessels  lined  with  lead)  to  cry^^tallize.    The 
mother  liquor  of  the  "roch  alum"  is  called  "tun  liquor;"  it  is,  of  course,  not 
qujte  so  pure  as  a  solution  of  roch  alum  in  water. 
The  alum-maker's  sp.  gr.  bottle  holds  80  pennyweights  of  water,  and  by  10  penny- 
weights he  means  10  more  than  water,  or  90.  -i        r       j 
The  numbers  on  Twaddle's  hydrometer,  divided  by  2-6,  give  alum-makers'  penny- 


'."   The  alum  mothers  are  boiled  down  to  a  crystallizing  point, 
of  "  Rough  Epsom,"  which  is  a  sulphate  of  magnesia  and  pro- 


lill 


'■\V 


11 


\\ 


'      i 

M  I 


68 


ALUM. 


The  alum-maker  tests  his  samples  of  potash  salts  comparatively  by  dissolving  equal 
weights  of  the  different  samples  in  equal  measures  of  alum  liquor  at  20  pennyweights, 
heated  up  to  the  boiling-point,  and  weighing  the  quantity  of  alum  crystals  produced 
on  cooling. 

For  the  above  information  I  am  indebted  to  my  friend,  Mr.  Maurice  Scanlan,  who 
superintended  for  some  time  the  Mulgrave  alum  works. 

He  informs  me  that  61 1  tons  of  the  alum  rock  at  the  Mulgrave  Works,  to  the  north 
of  Whitby,  yield,  after  calcination,  <fec.,  one  ton  of  alum. 

It  has  been  computed  that  with  sulphur  at  6/.  per  ton,  sulphuric  acid  of  sp.  gr^l-VSO 
can  be  produced  at  3^.  per  ton,  including  the  mere  cost  of  making :  this  acid  contains 
2  atoms  of  water:  174  tons  of  this  acid,  and  87^  tons  of  sulphate  of  potash,  with  the 
pipe-clay,  will  form  474  tons  of  alum ;  so  that  the  nett  cost  would  be  522/.  for  the 
acid -h  1047/.  for  the  sulphate  of  potash,  =  1 569/. ;  which  sum  divided  by  474,  gives  a 
quotient  of  31.  6s.  for  the  nett  cost  of  1  ton  of  alum  by  the  direct  process. 

At  the  pit  1  ton  of  alum — rock  or  mine,  costs  3/.  4s. ;  to  which,  adding  the  cost  of 
the  potash  salt  for  1  ton  of  alum,  3/.  15«.,  they  constitute  together  an  amount  of  6/.  19». 
From  the  latter  sum  1/.  10«.  must,  however,  be  deducted  for  the  value  of  rough  Epsom 
salt  produced,  leaving  a  balance  of  5/.  9*.  for  the  cost  of  a  ton  of  mine-alum,  prior  to 
evaporation  and  crystallization. 

A  patent  was  obtained  in  November,  1839,  by  Mr.  William  Wiesman,  of  Duesbui^, 
for  improvements  in  the  manufacture  of  alum.  He  subjects  potter's  claj^  to  a  moderate 
red  heat,  grinds  it,  and  subjects  the  powder,  in  leaden  pans,  to  the  action  of  concen- 
trated sulphuric  acid  (76°  Beaume),  taking  care  to  use  excess  of  clay  and  a  moderate 
heat.  This  mixture  is  to  be  stirred  till  it  is  dry,  then  treated  with  boiling  water,  in 
order  to  dissolve  the  sulphate  of  alumina  formed.  So  far  the  process  is  old  and  well 
known.  The  novelty  consists  in  freeing  the  saline  solution  from  iron  by  ferrocyanure 
of  potassium  (prussiate  of  potash).  When  the  iron  has  been  all  thrown  down  in  the 
form  of  Prussian  blue,  the  liquor  is  allowed  to  settle,  the  supernatant  pure  sulphate  is 
drawn  off,  and  evaporated  till  it  forms  on  cooling  a  concrete  mass,  which  may  be 
moulded  into  the  shape  of  bricks,  <fec.,  for  the  convenience  of  packing. 

Alum,  manufacture  of. — The  manufacture  of  alum  from  clay  and  clay  slate,  or  shale, 
is  now  beginning  to  assume  a  considerable  aspect  in  the  list  of  our  manufactures,  and 
several  improvements  in  this  way  have  lately  been  patented,  which  promise  to  extend 
largely  this  branch  of  industry.    One  in  particular,  for  the  fabrication  of  alum  from  the 
ash  or  residue  left  after  the  combustion  of  a  kind  of  coal,  called  Boghead  coal,  seems 
based  on  the  sound  principle  of  industrial  economy  which  turns  every  waste  product 
to  profitable  account     It  was  but  the  other  day  that  this  very  Boghead  ash  was  a 
serious  impediment  to  the  sale  of  the  coal,  and  perceptibly  diminished  its  price  in  the 
market.     Now,  however,  it  constitutes  a  decided  item  of  value,  and  powerfully  vindi- 
cates the  right  of  chemistry  to  the  title  of  a  useful  and  profitable  science.    In  preparing 
alum  from  clay  or  shale,  it  is  of  infinite  importance  that  so  much  and  no  more  heat  be 
applied  to  the  clay  or  shale,  in  the  first  instance,  as  will  just  expel  the  water  of  com- 
bination, without  inducing  contraction.     A  temperature  of  600°  Fahr.  is  well  adapted 
to  eflfect  this  object,  provided  it  be  maintained  for  a  sufficient  period.     When  this  has 
been  carefully  done,  the  silicate  of  alumina  remaining  is  easily  enough  acted  upon  by 
sulphuric  acid,  either  slightly  diluted  or  of  the  ordinary  commercial  strength.    The  best 
form  of  apparatus  is  a  leaden  boiler,  divided  into  two  parts  by  a  perforated  septum  or 
partition,  also  in  lead — though  on  a  very  large  scale,  brickwork  set  in  clay  might  be 
employed.     Into  one  of  the  compartments  the  roasted  clay  or  shale  should  be  put,  and 
diluted  sulphuric  acid  being  added,  the  bottom  of  the  other  compartment  may  be  ex- 
posed to  the  action  of  a  well-regulated  fire,  or — what  is  better — heated  by  means  of 
steam  through  the  agency  of  a  coil  of  leaden  pipe.     In  this  way  a  circulation  of  the 
fluid  takes  place  throughout  the  mass  of  shale;  and,  as  the  alumina  dissolves,  the  dense 
fluid  it  produces,  falling  continually  towards  the  bottom  of  the  boiler,  is  replaced  by 
dilute  acid,  which,  becoming  in  its  turn  saturated,  falls  like  the  first ;  and  so  on  in 
succession,  until  either  the  whole  of  the  alumina  is  taken  up,  or  the  acid  in  great  part 
neutralized.     The  solution  of  sulphate  of  alumina,  thus  obtained,  is  sometimes  evapo- 
rated to  dr3mess,  and  sold  under  the  name  "  concentrated  alum ;"  but  more  generally  it 
is  boiled  down  until  of  the  specific  gravity  of  about  J -35,  then  one  or  other  of  the  car- 
bonates, muriate,  or  sulphates  of  potash  or  ammonia,  or  a  mixture  of  these,  is  added  to 
the  boiling  fluid ;  and  as  soon  as  the  solution  is  complete,  the  whole  is  run  out  into  a 
cooler  to  crystallize.    The  rough  alum  thus  made  is  sometimes  purified  by  a  subsequent 
recrystallization,  after  which  it  is  "  roched  "  for  the  market — a  process  mtended  mere- 
ly to  give  it  the  ordinary  commercial  aspect,  but  of  no  real  value  in  a  chemical  point 
of  view.     Alum  not  imfrequently  contains  iron,  an  impurity  which  unfits  it  for  many 
uses  in  the  arts,  and  more  especially  for  the  purposes  of  the  dyer.     The  best  mode  of 


AMBER. 


59 


ascertaining  the  presence  of  this  impurity,  and  demonstrating  its  amount,  is  that 
previously  stated  in  the  commencement  of  this  article, — that  is,  mix  a  solution  of  the 
suspected  alum  with  tartaric  acid,  or  an  alkaline  tartrate,  and  then  add  an  excess  oi 
carbonate  of  soda ;  after  which,  pour  in  a  few  dropsofhydrosulphate  of  ammonia,  when, 
if  iron  be  present,  a  black  precipitate  w  ill  ensue.  If  the  alum  contains  lime  or  mag- 
nesia, then  the  addition  of  carbonate  of  soda  causes  h  white  precipitate,  which  must 
be  removed  by  filtration  before  applying  the  hydrosulphate  of  ammonia. 

Alum  manufacture  mnplificd. — vThe  alum  shale,  or  schist,  is  the  material  whence  the 
alum  is  obtained :  this  shale  is  roasted  in  heaps,  in  the  open  air,  in  order  to  render 
it  porous,  and  more  absorbent  of  the  sulphuric  acid.  To  the  roasted  shale,  sulphuric 
acid  of  sp.  gr.  1*76  is  added,  by  which  means  sulphate  of  alumina  is  formed.  In 
order  to  wash  out  from  the  almost  dry  mass  this  sulphate  of  alumina,  and  at  the  same 
time  to  supply  the  equivalent  of  the  sulphate  of  ammonia  necessary  to  constitute 
the  formation  of  the  double  salt  of  alumma  and  ammonia,  the  boiling  hot  mothei 
liquor  of  a  previous  operation  is  employed ;  and,  as  this  mother  liquor,  when  re 
moved  from  the  alum  crystallizers,  contams  free  sulphuric  acid,  the  ammonia  from  a 
still,  containing  the  ammoniacal  liquor  of  the  gas  works,  is  distilled  into  it,  and  the 
boiling  hot  solution  of  sulphate  of  ammonia  thus  formed  dissolves  out  the  sulphate 
of  alumina  from  the  shale.  The  alum  liquor  thus  obtained  is  of  such  a  specific 
gravity,  tliat  it  crystallizes  without  the  necessity  of  having  recourse  to  evaporation, 
and  thus  a  considerable  saving  in  fuel  is  effected.  In  order  to  obtain  ammoniacal 
salts,  such  as  sulphate  and  muriate,  with  the  greatest  possible  economy,  a  series  of 
two  or  more — say,  for  instance,  four— cylindrical  boilers  are  employed,  each  of  which 
is  placed  at  such  a  distance  above  the  other,  that  the  contents  of  the  upper  boiler  may 
be  drawn  off  into  the  one  next  below  it.  The  uppermost  boiler  is  provided  with  an 
exit  pipe,  and  has  also  a  supply  pipe,  connecting  the  boiler  with  a  reservoir  of  ammo- 
niacal gas  liquor.  Into  the  lowermost  vessel  of  the  series  passes  a  pipe  cbnvej-ing 
high  pressure  steam,  by  means  of  which  the  liquor  in  the  boiler  soon  becomes  heated 
to  the  boiling  point.  The  vapor  of  ammonia  and  water  pass  off  through  an  exit  pipe 
into  the  boiler  placed  next  above  it  in  the  series,  the  liquor  in  which  also  quickly  boils, 
and  vapor  of  ammonia  and  water  pass  off  in  the  same  way  as  before  to  the  next  vessel 
above  it,  and  so  throughout  the  series.  By  the  time  the  vapor  of  ammonia  passes  off 
fi-om  the  uppermost  boiler,  it  has  been  so  concentrated  that,  on  passing  it  into  sulphuric 
or  nmriatic  acid,  a  concentrated  solution  of  either  of  those  salts  is  obtained,  of  sufficient 
sp.  gr.  to  crystallize  without  evaporation,  and  thus  a  considerable  saving  in  fuel  and 
time  is  effected,  and  the  ammoniacal  liquor  most  thoroughly  exhausted.  Fresh  sup- 
plies  of  ammoniacal  liquor  are  constantly  furnished  to  the  uppermost  vessel  from  the 
reservoir;  the  partially  exhausted  liquors  are  run  from  the  higher  to  the  lower  vessels 
in  succession,  and  the  exhausted  liquors  run  off  to  waste,  from  time  to  time,  from  the 
lowermost  vessel  of  the  series. 

ALUMINA  The  pure  earth  of  clay,  or  argillaceous  earth.  It  is  the  oxide  of  the 
metal  alummum,  the  basis  of  the  aluminous  salts,  and  the  principal  constituent  of 
porcelain,  pottery,  bricks  and  tiles. 

AMADOU.  The  French  name  of  the  spongy  combustible  substance  called  in  Ger- 
man zundersehwamm,  prepared  from  a  species  of  agaric,  the  boletus  igniariua  a  kind 
of  mushroom  which  grows  on  the  trunks  of  old  oaks,  ashes,  beeches,  &c.  It  must  be 
plucked  in  the  months  of  August  and  September.  It  is  prepared  by  removing  the  outer 
bark  with  a  knife,  and  separating  carefully  the  spongy  substance  of  a  yellow  brown 
color  which  lies  within  it,  from  the  ligneous  matte^r  below.  This  substance  is  cut 
into  thm  slices,  and  beat  with  a  mallet  to  soften  it,  till  it  can  be  easily  pulled  asunder 
between  the  fingers.  In  this  state  the  boletus  is  a  valuable  substance  for  stoppimr 
oozing  hemorrhages,  and  some  other  surgical  purposes.  To  convert  it  into  tinder  it 
must  receive  afinishmg  preparation,  which  consists  in  boiling  it  in  a  strong  solution 
of  nitre ;  drying  it,  and  beating  it  anew,  and  putting  it  a  second  time  into  the  solution. 


or  fila- 
water.    ITie 
purpose.     Its 


Sometimes,  indeed,  to  render  it  very  inflammabl?,  it  is  imbued  with  gunpowder.' 
whence  the  distinction  of  black  and  brown  amadou. 

All  the  puff  balls  of  the  lycopodium  genus  of  plknts,  which  have  a  fleshy 
mentous  structure,  yield  a  tinder  quite  ready  for  soaking  in  gunpowder 
Hindoos  employ  a  leguminous  plant,  which  they  call  solu,  for  the  same  i 

A  AfTi^n^/^*^*^^'  ^^*°^  reduced  to  charcoal,  takes  fire  like  amadou. 

AMALCxAM.     When  mercury  is  alloyed  with  any  metal,  the  compound  is  called  an 

A\f  A?n  AxtArp?^^i?^'  r^^'.^*^'*  example,  au  amalgam  of  tin,  bismuth,  <fec. 

AMAJ.UAMAT10N,  Tins  is  a  process  used  extensively  in  extracting  silver  and 
goia  trom  certain  of  their  ores,  founded  on  the  property  which  mercury  has  to  dissolve 
these  metals  as  disseminated  in  the  minerals,  and  thus  to  separate  them  from  the 

A^S"^?^    ^^^  Mercury,  Metallurgy,  and  Silver. 

AMBER.     {Succm,  Fr. ;  Bernstein,  Germ.)    A  mineral  solid,  of  a  yellow  colour 


!l 


60 


JiMBER. 


of  various  shades,  which  bums  quite  away  with  flame,  and  consists  of  crarbon,  hydrogen, 
and  oxysren,  in  nearly  the  same  proportions,  and  the  same  state  of  combination,  as  vege- 
table resin.  Its  specific  gravity  varies,  by  my  trials,  from  1*080  to  1*085.  It  becomes 
negatively  and  powerfully  electrical  by  friction.  When  applied  to  a  lighted  candle  it 
takes  fire,  swells  considerably,  and  exhales  a  white  smoke  of  a  pungent  odor ;  but 
does  not  run  into  drops.  Copal,  which  resembles  it  in  several  respects,  differs  in  being 
softer,  and  in  melting  into  drops  at  the  flame ;  and  mellite,  or  honey-stone,  which  is  a 
mineral  of  a  similar  color,  becomes  white  when  laid  on  a  red-hot  coal. 

The  textiu-e  of  amber  is  resino-vitreous,  its  fracture  conchoidal,  and  lustre  glassy.  It 
is  perfectly  homogeneous ;  sufliciently  hard  to  scratch  gypsum,  and  to  take  a  fine  polish. 
It  is,  however,  scratched  by  calcareous  spar.  When  amber  is  distilled  in  a  retort, 
crystalline  needles  of  succinic  acid  sublime  into  the  dome,  and  oil  of  amber  drops  from 
the  beak  into  the  receiver.  Fossil  resins,  such  as  that  of  Highgate,  found  in  the  Lon- 
don clay  formation,  do  not  afford  succinic  acid  by  heat:  nor  does  copal.  Amber  is 
occasionally  found  of  a  whitish  and  brownish  color. 

The  most  interesting  fact  relative  to  this  vegeto-mineral  is  its  geological  position, 
which  is  very  characteristic  and  well  determined.  It  is  found  almost  uniformly  in  sepa- 
rate nodules,  disseminated  in  the  sand,  clay,  or  fragments  of  lignite  of  the  plastic  clay, 
and  lignite  formation,  situated  between  the  calcaire  grossier  (crag  limestone)  of  the 
tertiary  strata  above,  and  the  white  chalk  below.  The  size  of  these  nodules  varies  from 
a  nut  to  a  man's  head;  but  this  magnitude  is  very  rare  in  true  amber.  It  does  not 
occur  either  in  continuous  beds,  like  the  chalk  flints,  nor  in  veins ;  but  it  lies  at  one 
lime  in  the  earthy  or  friable  strata,  which  accompany  or  include  the  lignites ;  at  another, 
entangled  in  the  lignites  themselves;  and  is  associated  with  the  minerals  which  constitute 
this  formation,  principally  the  pyrites,  the  most  abundant  of  all.  The  pieces  of  amber 
found  in  the  sands,  and  other  formations  evidently  alluvial,  those  met  with  on  the  sea- 
coasts  of  certain  countries,  and  especially  Pomerania,  come  undoubtedly  from  the  above 
geological  formation ;  for  the  organic  matters  found  still  adhering  to  the  amber  leave 
no  doubt  as  to  its  primitive  place.  Amber  does  not,  therefore,  belong  to  any  postdilu- 
vian or  modern  soil,  since  its  native  bed  is  covered  by  three  or  four  series  of  strata,  often 
of  considerable  thickness,  and  well  characterized;  proceeding  upwards  from  the  plastic 
clay  which  includes  the  amber :  these  are,  the  crag  limestone,  the  bone  gypsum,  with 
its  marls,  the  marly  limestone,  the  upper  marl  sandstone,  which  covers  it,  and,  lastly, 
the  fresh  water  or  lacustrine  formation,  often  so  thick,  and  composed  of  calcareous  and 
siiicious  rocks.  ,    ,  ' 

The  amber  bed  is  not,  however,  always  covered  with  all  these  strata ;  and  it  is  even 
rare  to  see  a  great  mass  of  one  of  them  above  the  ground  which  contains  it;  because, 
were  it  buried  under  such  strata,  it  would  be  difiicult  to  meet  with  such  circumstances 
as  would  lay  it  spontaneously  open  to  the  day.  But  by  comparing  observations  made 
in  diflerent  places,  relatively  to  the  patches  of  these  formations,  which  cover  the  amber 
deposites,  we  find  that  no  other  mineral  formations  have  been  ever  seen  among  them 
except  those  above  detailed,  and  thus  learn  that  its  geological  locality  is  completely  de- 
termined. 

The  proper  yellow  amber  therefore,  or  theBorussic,  from  the  country  where  it  has  been 
most  abundantly  found,  belongs  to  the  plastic  clay  formation,  intermediate,  in  England, 
between  the  chalk  and  the  London  clay.  It  is  sometimes  interposed  in  thin  plates  between 
the  layers  of  the  lignites,  but  more  towards  the  bark  of  the  fibrous  lignites,  which  retain 
the  form  of  the  wood,  than  towards  the  middle  of  the  trunk  of  the  tree ;  a  position  analo- 
gous to  that  of  the  resinous  matters  in  our  existing  ligneous  vegetables.  The  fibrous 
lignites  which  thus  contain  amber  belong  to  the  dicotyledinous  woods.  Hence  that 
substance  seems  to  have  been  formed  during  the  life  of  the  vegetable  upon  which  it  is 
now  incrusled.  It  must  be  remembered  that  the  grounds  containing  the  amber  are 
often  replete  with  the  sulphates  of  iron,  alumina,  and  lime,  or  at  least  with  the  pyritoug 
elements  of  these  salts.  Some  specimens  of  amber  have  a  surface  figured  with  irregular 
meshes,  indicating  a  sort  of  shrinkage  from  consolidation,  and  consequently  a  matter 
that  was  at  one  time  fluid,  viscid,  or  merely  soft.  From  optical  examination,  Dr. 
Brewster  has  concluded  amber  to  be  of  vegetable  origin. 

The  different  bodies  included  in  the  amber,  distinguishable  from  its  transparence,  demon- 
strate, indeed,  in  the  most  convincing  manner,  its  primitive  state  of  liquidity  or  softness. 
These  bodies  have  long  exercised  the  skill  of  naturalists.  They  are  generally  insects, 
or  remains  of  insects,  and  sometimes  leaves,  stalks,  or  other  portions  of  vegetables. 
Certain  families  of  insects  occur  more  abundantly  than  others.  Thus  the  kymenoptera, 
or  insects  with  four  naked  membranaceous  wings,  as  the  bee  and  wasp,  and  thediplera^ 
or  insects  with  two  wings,  as  gnats,  flies,  gadflies,  &c. ;  then  come  the  spidei  tribe; 
some  coleoptera  (insects  with  crustaceous  shells  or  elytra,  which  shut  together,  and  form 
a  longitudinal  suture  down  the  back),  or  beetles,  principally  those  which  live  on  trees ; 
such  as  the  elaterides,  or  leapers,  and  the  chrysomelida.    The  lepidoptera,  or  insects  with 


AMMONIA. 


n 


four  membranaceous  wings,  and  pterigostea  covered  with  mail-like  scales,  are  very  rare 
in  amber.  We  perceive  from  this  enumeration,  which  results  from  the  labors  oi 
Germar,  Schweiger,  &c.,  that  the  insects  enveloped  in  this  resinous  matter  are  in 
general  such  as  sit  on  the  trunks  of  trees,  or  live  in  the  fissures  of  their  bark.  Hitherto, 
it  has  not  been  found  possille  to  refer  them  to  any  living  species;  but  it  has  been  ob- 
served in  general  that  they  resemble  more  the  insects  of  hot  climates  than  those  of  the 
temperate  zones. 

The  districts  where  amber  occurs  in  a  condition  fit  for  mining  operations  are  not 
numerous ;  but  those  in  which  it  is  met  with  in  small  scattered  bits  are  very  abundant. 
Its  principal  exploitation  is  in  Eastern  Prussia,  on  the  coasts  of  the  Baltic  Sea,  from 
Memel  to  Dantzick,  particularly  in  the  neighborhood  of  Konigsberg,  along  the  shore 
which  runs  north  and  south  from  Grossdirschheim  to  Pillau,  and  in  several  other  places 
near  Dantzick. 

It  is  collected  upon  this  coast  in  several  ways ;  1.  In  the  beds  of  small  streams  which 
run  near  the  villages,  and  in  rounded  fragments  without  bark,  or  in  the  sand-banks  of 
rivers,  in  pieces  thrown  back  by  the  sea,  and  rounded  by  the  waves.  2.  If  the  pieces 
thrown  up  by  the  waters  are  not  numerous,  the  fishers,  clothed  in  a  leather  dress,  wade 
into  the  sea  up  to  the  neck,  seek  to  discover  the  amber  by  looking  along  its  surface,  and 
seize  it  with  bag  nets,  hung  at  the  end  of  very  long  poles.  They  conclude  that  a  great 
deal  of  amber  has  been  detached  from  the  cliffs  by  the  sea,  when  many  pieces  of  lignite 
(wood  coal)  are  seen  afloat.  This  mode  of  collecting  amber  is  not  free  from  danger,  and 
the  fishers,  therefore,  advance  in  troops,  to  lend  each  other  aid  in  case  of  accident ;  but 
their  success,  even  thus,  is  most  precarious.  3.  The  third  method  of  searching  for  am- 
ber is  a  real  mining  operation  :  it  consists  in  digging  pits  upon  the  borders  of  the  sandy 
downs,  sometimes  to  a  depth  of  more  than  130  feet.  4.  The  last  mode  is  by  exploring 
the  precipitous  sea  cliffs  in  boats,  and  detaching  masses  of  loose  soil  from  them  with  long 
poles  terminating  in  iron  hooks ;  a  very  hazardous  employment.  They  search  the  cliffs 
with  great  care  at  the  level,  where  the  amber  nodules  commonly  lie,  and  loosen  the  seams 
with  iheir  hooks ;  in  which  business  the  boats  are  sometimes  broken  against  the  preci- 
pices, or  sunk  by  an  avalanche  of  rubbish. 

Amber  occurs  in  Sicily,  disseminated  in  beds  of  clay  and  marl,  which  lie  below  the 
crag  limestone.  It  is  accompanied  with  bitumen ;  and,  though  a  scanty  deposite,  it  is 
mined  for  sale.  The  pieces  are  coated  with  a  kind  of  whitish  bark,  present  a  variety 
of  colors,  and  include  many  insects.  Amber  is  found  in  a  great  many  places  in  the  sandy 
districts  of  Poland,  at  a  very  great  distance  from  the  sea,  where  it  is  mixed  with  cones 
of  the  pine.  In  Saxony  it  is  met  with  in  the  neighborhood  of  Pretsch  and  Wiltemberg, 
in  a  bitununous  clay  mingled  with  lignite.  At  the  embouchure  of  the  Jenissey,  in  Sibe- 
ria, it  occurs  likewise  along  with  lignite ;  as  also  in  Greenland. 

Fine  amber  is  considerably  valued  for  making  ornamental  objects,  and  the  coarser 
kinds  for  certain  uses  in  chemistry,  medicine,  and  the  arts.  The  oriental  nations  prize 
more  highly  than  the  people  of  Europe  trinkets  made  of  amber ;  and  hence  the  cliief 
commerce  of  the  Pomeranian  article  is  with  Turkey.  The  Prussian  government  is  said 
to  draw  an  annual  revenue  of  17,000  dollars  from  amber.  A  good  piece  of  a  pound 
weight  fetches  50  dollars.  A  mass  weighing  13  pounds  was  picked  up  not  long  since  in 
Prussia,  for  which  5000  dollars  were  offered,  and  which  would  brinsr,  in  the  opinion  of 
the  Armenian  merchants,  from  30,000  to  40,000  dollars  at  Constantinople.  At  one  time 
it  was  customary  to  bake  the  opaque  pieces  of  amber  in  sand,  at  a  gentle  heat,  for  sev- 
eral hours,  in  order  to  make  it  transparent,  or  to  digest  it  in  hot  rapeseed  oil,  with  the 
same  view ;  but  how  far  these  processes  were  advantageous  does  not  appear. 

When  amber  is  to  be  worked  into  trinkets,  it  is  first  split  on  a  leaden  plate  at  a  lathe 
(see  Gems,  Cutting  of),  and  then  smoothed  ir  ;o  shape  on  a  Swedish  whetstone.  It  is 
polished  on  the  lathe  with  chalk  and  water,  or  vegetable  oil,  and  finished  by  friction 
with  flannel.  In  these  processes  the  amber  is  apt  to  become  highly  electrical,  very  hot, 
and  even  to  fly  into  fragments.  Hence,  the  artists  work  the  pieces  time  about,  so  as  to 
keep  each  of  them  cool,  and  feebly  excited.  The  men  are  often  seized  with  nervous 
tremors  in  their  wrisis  and  arms  from  the  electricity.  Pieces  of  amber  may  be  neatly 
loined  by  smearing  their  edges  with  linseed  oil,  and  pressing  them  strongly  together, 
while  they  are  held  over  a  charcoal  fire.  Solid  specimens  of  amber,  reported  to  have 
been  altogether  fused  by  a  particular  application  of  heat,  are  now  shown  in  the  royal 
cabinet  of  Dresden. 

A  strong  and  durable  varnish  is  made  by  dissolving  amber  in  drj'ing  linseed  oil.  For 
this  purpose,  however,  the  amber  must  be  previously  heated  in  an  iron  pot,  over  a  clear 
red  fire,  till  it  soften  and  be  semi-liquefied.  The  oil,  previously  heated,  is  to  be  now' 
poured  in,  with  much  stirring,  in  the  proportion  of  10  ounces  to  the  pound  of  amber,* 
and  after  the  incorporation  is  complete,  and  the  liquid  somewhat  cooled,  a  pound  of  oil 
of  turpentine  must  be   added.     Some   persons  prescribe  2  ounces  of  melted  s,'iellac. 


i!i  i 


62 


AMYGDALINE. 


though  by  this  means  they  are  apt  to  deepen  the  colour,  already  rendered  too  dark 
iJ     i?  joastmg.     The  finest  varnish  is  made  with  oil  of  spike. 

though  by  this  means  they  are  apt  to  deepen  the  color,  already  rendered  too  dark  by  tiic 
roasting  • 

The  fine  black  varnish  of  the  coachmakers  is  said  to  be  prepared  by  melting  16  ounces 
ot  amber  m  aniron  pot,  adding  to  it  half  a  pint  of  drying  linseed  oil,  boiling  hot,of  pow- 
dered  resin  and  asphaltum  3  ounces  each :  when  the  materials  are  well  united  by  stir- 
ring  oyer  the  fire,  they  are  to  be  removed,  and,  after  cooling  for  some  time,  apint  of  warm 
oil  of  turpentine  is  to  be  introduced. 

The  oil  of  amber  enters  into  the  composition  of  the  old  perfume  called  eau  de  luce  • 
and  IS  convertible,  by  the  action  of  a  small  quantity  of  strong  nitric  acid,  into  a  viscid 
mass  like  shoemakers'  rosin,  which  has  a  strong  odor  of  musk,  and,  under  the  name  of 
artificial  musk,  has  been  prescribed,  m  acoholic  solution,  as  a  remedy  against  hooping 
cough,  and  other  spasmodic  diseases.  *^    ° 

Acid  of  amber  (*ttcct«ic  add)  is  a  delicate  reagent,  in  chemistry,  for  separating  red 
oxyde  of  iron  from  compound  metallic  solutions.  J*  i'    «»""S  r«i 

.f"^^^^^^^^:-  ('i'^l^^'^Sric,  Fr. ;  ^mbra,  Germ.)-A  morbid  secretion  of  the  liver 
t.  JtTn"^''''^^'  ^,*lf^^  (physeter  macrocephalus),  found  usually  swimminsj  upon  the 
TnA  J  ?  "^r  ^^^  *'°^'*'  ^^  Coromandel,  Japan,  the  Moluccas,  and  Madagascar, 

and  has  sometimes  been  extracted  from  the  rectum  of  whales  in  the  South  s--,  fished 
It  has  a  gray-white  color,  often  with  a  black  streak,  or  is  marbled,  yellow  and  black  ;* 
r  rUfP  ^^^  a'  "^^^^  ag^^eeable  smell,  a  fatty  taste,  is  lighter  than  water,  melts  at  60^ 

oik  Tt  fnn?.n'°«rVfK  r^  ""  ''^^''^T  ^'^°^°^'  ^"  "^^^'•'  ^"^  ^»  ^^^  ^«t  ^nd  volatile 
oils.     It  contains  85  of  the  fragrant  substance  called  amhreiiie.     This  is  extracted  from 

ambergris  by  digestion  with  alcohol  of  0-827,  filtering  the  solution,  and  leavin- it  to 

spontaneous   evaporation.     It  is  thus   obtained  in  the  form  of  delicate  white  lufts  • 

l^  erfumV*'"''^''^  '"*''  ^°'^'"^'*'  """"^  ^^  ^^^  ^''^''"'  ""^  "'^""^  ^"^-  Ambergris  is  used 
'^JJl^/^J^^^"  ^  mineral  in  silky  filaments,  called  also  Asbesttts. 
AMMONIA.  A  chemical  compound,  called  also  volatile  alkali.  This  substance,  in  its 
purest  state,  is  a  highly  pungent  gas,  possessed  of  all  the  mechanical  properties  of  the 
air,  but  very  condensable  with  water.  It  consists  of  3  volumes  of  hydrogen  and  1  of  azote 
condensed  mto  two  volumes  ;  and  hence  its  density  is  0-591,  atmospheric  air  bein-  1-000 
By  strong  compression  and  refrigeration  it  may  be  liquefied  into  a  fluid,  whose  specific 
gravity  is  0-76  compared  to  water  1-000.  '  specmc 

Ammonia  gas  is  composed  by  weight  of  82-53  azote  and  17-47  hydrogen  in  100 
K  •  Ir^  obtained  by  mixing  muriate  of  ammonia,  commonly  caUed  sal  ammoniac, 
with  quicklime  m  a  retort  or  still,  applying  a  moderate  heat,  and  receiving  the  eas  eilhe^ 
oyer  mercury  for  chemical  experiments,  or  in  water  to  make  liquid  ammonia  for  the 
condensation"'       '"^  ''''^^'     ^^""^^^'^  apparatus  is  commonly  employed  for  this 

Ammonia  is  generated  in  a  great  many  operations,  and  especially  in  the  decomposition 
of  many  organic  substances,  by  fire  or  fermentation.  Urine  left  to  itself  for  a  few  days  is 
found  to  contain  much  carbonate  of  ammonia,  and  hence  this  substance  was  at  one  time 
coUected  in  great  quantities  for  the  manufacture  of  certain  salts  of  ammonia,  and  is  stiD 
T^  L  ^"^aline  properties  m  making  alum,  scouring  wool,  &c.  When  woollen  rags, 
horns,  bones,  ana  other  animal  substances  are  decomposed  in  close  vessels  by  fire  thev 
evolve  a  large  quantity  of  ammonia,  which  distils  over  in  the  form  of  a  carbonate  The 
mam  source  of  ammonia  now  in  this  country,  for  commercial  purposes,  is  the  coal  gas 
works.  A  large  quantity  of  watery  fluid  is  condensed  in  their  tar  pits,  which  contains 
chiefly,  ammonia  combined  with  sulphureted  hydrogen  and  carbonic  acid.  When  this 
water  is  saturated  with  muriatic  acid  and  evaporated  it  yields  muriate  oi:  ammonia,  or 
sal  ammoniac,  somewhat  impure,  which  is  afterwards  purified  by  sublimation.  See 
Carbonate  of  Ammonia  and  Sal  Ammoniac.  "iia.iuu.     otc 

The  soot  of  chimneys  where  coal  is  burned  contains  both  sulphate  and  carbonate  of 
ammonia,  and  was  extensively  employed,  at  one  time,  to  manufacture  these  salts. 

In  making  water  of  ammoma  on  the  great  scale,  a  cast  iron  ^tiU  should  be  preferred, 
and  equal  weights  of  quickhme  and  sal  ammoniac  should  be  brought  to  the  consistence 
A'^l'  '^^'^^.'^^T'  ^^^°/t^^^  heat  is  applied.  In  this  case  a  refrigeratory  worm  or 
globe  should  be  interposed  between  the  adopter  tube  of  the  capital  of  the  still  and  the 
bottles  of  Woulfe  s  apparatus.  1  he  muriate  of  lime,  or  chloride  of  calcium,  which  is  left 
m  the  still  when  the  whole  ammonia  is  expelled,  is  of  no  value.  Water  is  capable  of 
condensmg  easily  about  one  third  of  its  weight  of  ammonia  gas,  or  460  times  its  bulk. 
The  foUowmg  table  of  the  quantity  of  ammonia  in  100  parts  by  weight  of  its  aqueous 
combinations,  at  successive  densities,  is  the  result  of  very  careful  experiments  made  by 
me,  and  recorded  in  the  Philosophical  Magazine  for  March   1821. 


^ 


ANCHOR. 
Table  of  Water  of  Ammonia  or  Volatile  jSlkali,  by  Dt   Ure, 


68 


Water 

of 
0-900 


100 

95 
90 
85 
80 
75 
70 
S5 
60 
55 
50 
45 
40 
35 
30 
25 
20 
15 
10 
6 


Ammonia 
in 
100 


26-500 

25-175 

23-850 

22-525 

21-200 

19-875 

18-550 

17-225 

15-900 

14-575 

13-250 

11-925 

10-600 

9-275 

7-950 

6-625 

6-300 

3-975 

2-650 

1-325 


Water 
in 
100 


73-500 
74-825 
76-150 
77-475 
78-800 
80125 
81-450 
82-775 
84-100 
85-425 
86-750 
88-075 
89-400 
90-725 
92050 
93-375 
94-700 
96-025 
97-350 
98-675 


Specific 

gravity  by 

experiment. 


0-9000 
0-9045 
0-9090 
0-9133 
0-9177 
0-9227 
0-9275 
0-9320 
0-9363 
0-9410 
0-9455 
0-9510 
0-9564 
0-9614 
0-9662 
0-9716 
0-9768 
0-9828 
0-9887 
0*9945 


Mean 
specific 
gravity. 


0-90452 

0-90909 

0-91370 

0-91838 

0-92308 

0-92780 

0-93264 

0-93750 

0-94241 

0-94737 

0-95238 

0-95744 

0-96256 

0-96774 

0-97297 

0-97826 

0-98360 

0-98900 

0-99447 


Equivalent  primes. 


Wat,  Jim. 
6  to  1 


24  4-76 
21-25  4-78-75,       7  to  I 


19-1 -f- 80-9, 
17-35  -f  82-65, 

15-9  4-84-1, 
14-66  -j-  85-34, 


13-60 
11-9 
11-2 

8-63 

7 

6 

4-5- 

3 


86-40, 
-88-1, 
-  88-8, 

91-37, 

93, 

94, 

95-5, 

97, 


8  to  1 

9  to  1 

10  to  1 

11  to  1 

12  to  1 

14  to  1 

15  to  1 

20tol 
25  to  1 
30  to  1 
40  to  1 
60  to  1 


AMMONIAC,  gum-resin.  This  is  the  inspissated  juice  of  an  umbelliferous  plant 
(the  dorema  armmiacum)  which  grows  in  Persia.  It  comes  to  us  either  in  small 
white  tears  clustered  together,  or  in  brownish  lumps,  containing  many  impuritie^s  It 
possesses  a  peculiar  smell,  somewhat  like  that  of  asafcetida,  and  a  bitterish  taste*  It 
IS  employed  m  medicine  Its  only  use  in  the  arts  is  for  forming  a  cement  to* loin 
broken  pieces  of  china  and  glass,  which  may  be  prepared  as  follows:  Take  isin-lass 
1  ounce,  distilled  water  6  ounces,  boil  together  down  to  3  ounces,  and  add  1*  ounce  of 
strong  spirit  of  wme;  boil  this  mixture  for  a  minute  or  two;  strain  it;  add  whSe 
hot,  first,  half  an  ounce  of  a  milky  emulsion  of  gum  ammoniac,  and  then  five  dJams  of 
an  alcoholic  solution  of  resin  mastic.     This  resembles  a  substance  sold  in  the  London 

dlTisi^n"  chemist""'  "'  ''"""^  """''     ^'^  ^^"^^  "^^  ^^^'^»  ^'  ^^  ^  -'p-taTle 

in  to^stre^a^Ao  ZtZt""'  "^^  ^'  °^'"^^^^  ^'''  ^^^^^  ^^^^^^  ^^-^  occu, 
AMYGDALINE  is  a  principle  of  bitter  almonds  and  of  bay-laurel  berries  It  is 
obtained  by  digesting,  in  a  retort,  alcohol  of  0-825  at  its  boili^ Lmpemtu^e  unon 
the  nieal  ofbitter  almonds,  then  distilling  off  the  alcohol  by  the  Lat  of  a  water-ba?S 
till  the  residuum  assumes  the  consistence  of  svrun  To  thp  r^ctl  ,„«,  A^^  Y*}^^  .^f » 
little  water,  some  yeast  is  to  be  add<fd  and  tfie  fixture  is  to  L«r'  ^5  -'^  ^'^^'  * 
glace  for  some  timJto  ferment.  Whenever  th:  Wn^  UrisXl^lfe^LV^^^^^ 
be,  filtered  and  evaporated  on  the  water-bath  to  a  svrupv  consistence  O^Zwill 
wiicirXrr^-  "''"'"'  "'?f ''  '''^  amygdahne  falls^inTwhiL  c^^^^ 


40  atoms  of  carbon 
27        —     hydrogen 

1        —     azote 
22        —     oxygen 


62-98  in  100  parts. 

6-84        — 

3-06         — 
38-12         — 


atom  amygdaline  {Liebig) 


100-00 


-He  purpose  of  the  fermentation  above  preseribed  is  to  deeompose  a  portion  of  s„g.r. 


ilfMP 


(      I 


64 


ANCHOR. 


extracted  by  the  alcohol  from  the  bitter  almonds  along  with  the  amygdaline,  of  which 
latter  they  afford  from  3  to  4  per  cent.  .     .  , 

Almonds,  both  bitter  and  sweet,  contain  also  another  curious  principle,  called  emulnne 
by  Liebig,  and  synaptase  by  Robiquet.  It  is  soluble  in  water,  but  is  precipitated  fronri  it 
in  flakes  by  alcohol.  It  coagulates  at  the  temperature  of  about  140°  Fahr.  hke  white 
of  egg.  On  mixing  a  solution  of  10  parts  of  amygdaline  in  100  parts  of  water, 
with  1  part  of  synaptase  in  10  parts  of  water,  a  peculiar  decomposition  immediately 
takes  phaee.  The  mixture  becomes  opaline  without  losing  its  transparency ;  it  assumes 
the  odor  of  bitter  almonds,  and  yields,  on  distillation,  hydrocyanic  (prussic)  acid,  and 
the  hydrure  of  benzoil  (pure  essence  of  bitter  almonds),  mixed  with  vapor  of  water. 
Coagulated  synaptase  has  no  perceptible  action  on  amygdaline.  These  facta  explain 
a  series  of  puzzling  phenomena,  which  have  been  long  known.  Fresh  bitter  almonds 
contain  emulsine  (synaptase),  amygdaline,  and  an  unctuous  oil,  all  in  such  a  state  that 
the  first  two  cannot  react  upon  each  other ;  and  by  removing  the  water  by  desiccation 
their  mutual  action  becomes  impossible.  On  squeezing  the  almonds  the  oil  is  drawn 
off,  and  on  treating  the  cake  with  boiling  alcohol  the  amygdaline  is  dissolved  out,  and 
the  synaptase  is  coagulated ;  but  on  moistening  the  bitter  almonds  with  water  the 
reaction  of  the  two  principles  becomes  instantly  effective,  as  shown  by  the  production 
of  the  smell  and  taste  of  hydrocyanic  acid  and  of  the  essential  oil.  By  throwing  the 
bitter  almond  meal  into  boiling  water  the  synaptase  immediately  coagulates,  and  the 
above  mutual  reaction  can  no  longer  be  obtained,  nor  the  above  volatile  products. 
In  order  properly  to  prepare  the  essence  of  bitter  almonds  it  is  therefore  necessary 
to  mix  1  part  of  bitter  almond  meal  with  20  parts  of  lukewarm  water,  to  leave  the 
mixture  to  digest  for  24  hours,  and  only  then  to  submit  it  to  distillation.  100  parts 
of  amygdaline  produce  47  parts  of  the  crude  essence  of  bitter  almonds,  which  contain 
5-9  parts  of  hydrocyanic  acid. 

AMYLOXmE-HYDRATK     See  Fusel  Oil. 

ANALYSIS.  The  art  of  resolving  a  compound  substance  or  machine  into  its  con- 
stituent parts.  Every  manufacturer  should  so  study  this  art,  in  the  proper  treatises, 
and  schools  of  chemistry  or  mechanics,  as  to  enable  him  properly  to  understand  and 

regulate  his  busines^s.  .        ,      ,      ,         •-,      ^^         -v. 

ANCIIOR.  {Ancre,  Fr. ;  Anker,  Germ.)  An  iron  hook  of  considerable  weight 
and  strengtli,  for  enabling  a  ship  to  lay  hold  of  the  ground,  and  fix  itself  in  a  certain 
situation  by  means  of  a  rope  called  the  cable.  It  is  an  instrument  of  the  greatest  im- 
portance to  the  naviixator,  since  upon  its  taking  and  keeping  hold  depends  his  safety 
upon  many  occasions,  especially  near  a  lee  shore,  where  he  mi^ht  be  otherwise 
stranded  or  shipwrecked.  Anchors  are  generally  made  of  wrought  iron,  except  among 
nations  w-ho  cannot  work  this  metal  well,  and  who  therefore  use  copper.  The  mode 
in  which  an  anchor  operates  will  be  understood  from  inspection  of /jr.  12,  where  from 
the  direction  the  strain,  it  is  obvious  that  the  anchor  cannot  move  without  plough- 
ing up  the  ground  in  which  its  hook  or  fluke  is  sunk.  When  this,  however,  unluckily 
takes  place,  from  the  nature  of  the  ground,  from  the  mode  of  insertion  of  the  anchor,  or 
from  the  violence  of  the  winds  or  currents,  it  is  called  dragging  the  anchor.  Whc^ 
the  hold  is  good,  the  cable  or  the  buried  arm  will  sooner  break  than  the  ship  will 
drive.  Anchors  are  of  different  sizes,  and  have  different  names,  according  to  the  pur- 
poses they  serve  ;  thus  there  are  sheet,  best  bower,  small  bower,  spare,  stream,  and  kedge 
anchors.  Ships  of  the  first  class  have  seven  anchors,  and  smaller  vessels,  such  as 
brigs  and  schooners,  three. 


I 


J- 


ANCHOR. 


65 


The  manufacture  of  anchors  requires  great  knowledge 
of  the  structure  of  iron,  and  skill  in  the  art  of  working 
it.  I  shall  give,  here,  a  brief  notice  of  the  improved  system 
introduced  by  Mr.  Perring,  clerk  of  the  cheque  at  Ply- 
mouth, in  which  the  proportions  of  the  parts  are  admirably 
adapted  to  the  strains  they  are  likely  to  sufler.  In  fig.  13 
A  is  the  shank ;  b,  the  arm  or  Jluke  ;  c,  the  palm ;  d,  the 
blade  ;  E,  the  square ;  f,  the  nut ;  g,  the  ring ;  h,  the  craven. 
Formerly  the  shank  was  made  of  a  number  of  square 
iron  rods,  laid  parallel  together  in  a  cylindrical  form,  and 
bound  by  iron  hoops.  When  they  were  welded  into  one 
bar,  the  exterior  rods  could  not  fail  to  be  partially  burned 
and  wasted  by  the  strong  heat.  Mr.  Perring  abated  this 
evil  by  using  bars  of  the  whole  breadth  of  the  shank,  and 
placing  them  right  over  each  other,  hooping  them  and 
welding  them  together  at  two  heats  into  one  solid  mass. 
.  .„  .  , .         To  any  one  who  has  seen  the  working  of  puddled  iron,  with 

a  heavy  milt  hammer,  this  operation  will  not  appear  difficult. 

He  formed  the  crown  with  bars  similarly  distributed  with  those  of  the  shank.  His 
mode  of  uniting  the  flukes  to  the  crown  is  probably  the  most  valuable  part  of  his 
invention.  The  bars  and  half  the  breadth  of  the  anchor  are  first  welded  separately,  and 
then  placed  side  by  side,  where  the  upper  half  is  worked  into  one  mass,  while  the  lower 
part  is  left  disunited,  but  has  carrier  iron  bars,  or  porters,  as  these  prolongation  rods 
are  commonly  called,  welded  to  the  extremity  of  each  portion.  The  lower  part  is  now 
beated  and  placed  m  the  clamping  machine,  which  is  merely  an  iron  plate  firmly  bolted 
to  a  mass  of  timber,  and  bearing  upon  its  surface  four  iron  pins.  One  end  of  the  crown 
IS  placed  between  the  first  of  these  pins,  and  passed  under  an  iron  strap;  the  other  end 
is  brought  between  the  other  pins,  and  is  bent  by  the  leverage  power  of  the  elongated 
rods  or  porters.  &  -v-« 

Thus  a  part  of  the  arm  being  formed  out  of  the  crown  gives  much  greater  security 
ecJrf  ^"'^'^        ^^^^  ^^  eflected,  than  when  the  junction  was  made  merely  by  a  short 

The  angular  opening  upon  the  side  opposite  b  n,  fig.  13,  is  filled  with  the  chock, 
formed  of  short  iron  bars  placed  upright.  When  this  has  been  firmly  welded,  the  truss! 
piece  IS  brought  overit.  This  piece  is  made  of  plates  similar  to  the  above,  except  thar 
their  edges  are  here  horizontal.  The  truss-piece  is  half  the  breadth  of  the  ^m  ;  so  that 
Trms  atTho^  lace^s  '''°'^'''  "  consUtutes,  with  the  other  parts,  the  total  breadth  of  the 
;»  Tllltfi"''  ''  "«^^shut  upon  the  crown;  the  square  is  formed,  and  the  nuts  welded  to 

Vk    ?,  ^^  ''•  P""'?^'^  """^  ^'"'  ^^^  ""?'  ^"d  the  shank  is  then  fashioned. 
rnJif  fiic.  K  '".  ?^t  ^,J°"<^^  '"^  .the  way  above  described.     In  making  the  palm,  an  iron 
rod  IS  first  bent  mto  the  approximate  form,  notching  it  so  that  it  may  more  readily  ta^e 
the  desired  shape.     To  one  end  a  porter  rod  is  fastened,  by  which  the  palmTcaSed 

r«^-H  S^h  '°"'?'^  "*  '^^  f  ^  ^T"=  '^^  P^^^^^^^  °f  the  fabrication.  Iron  plates  are^eS 
ad  side  by  side  upon  the  rod,  and  the  joint  at  the  middle  is  broken  by  another  plafe 
aid  over  i .     When  the  mass  is  worked,  its  under  side  is  filled  up  bv  similar  p  ates  and 

Intl^s  tf  lT:t'%r't'l  ^"ff  't=  ^''^^  ''  ^^^  ^'^^^'  ff  necessa^  S  tSe 
angles  ot  the  palm.     The  blade  is  then  shut  on  to  the  palm,  af\er  which  the  nart  of  tho 

J:S  and^:t  MlTpon'S'me^^^^^^^  ^^It^  ^  -  th^  ^le  enyaro'vtS 

ram,  ana  lei  lall  upon  the  metal  previously  brought  to  a  welding  heat. 

yyl^n^ZorZ^m'^l  ^? m'  ^""^  '^^?  ^"™^  ^^°^^«'  "^  «""  instruments,  and  are 

Xn^h^-'   i^""^  °^^''  °'°^^'  ^^  manufacturing  anchors  have  been  deviled,  iS 
Which  mechanical  power  is  more  extensively  resorted  to. 

Iv  andK^'fr  "^  V'^  '^^"^  ^(^g.l3)is  squared  to  receive  and  hold  the  stock  steadi- 

ekon  likrnrn-pM-"'    "^"T^'    ^^  P'."™^  '^  ^^^'""^  ^^^^^^  ^here  are  two  knobs  or 

sometime.  ST';.  ^^'  ^l!'^  ^^  ^^^  ^"=^^  "'  ^^^ween  the  arms  and  the  shank,  is 

Th/,;Ji '  r    I  ^^  '^''r^  ""^  polygonal,  and  about  half  the  length  of  the  shank, 
brace  the  t^L!!  ^T^""'  i^^\  ^^^^^  °^^^^  «^ «^-     ^^  consists  of  two  beams  which  em- 
T?e  sttk  Tu  iX  Z  *r^/r^ted  by  iron  bolts  and  hoops,  as  shown  in  the  figuS. 

atout  o^e  twemh^LTn^^^^^      l^?^^'  '^"^  ^**^  '^^'^^^  ^"^  ^^  '^^  °^i^^^  ^  thickness 
ooui  one  tweUlh  of  its  length,  but  tapers  at  its  under  side  to  nearly  one  half  this  thick 


i> 


66 


ANCHOR. 


ANCHOR. 


m 


III 


ness  at  the  extremities.    In  small  anchors  the  stock  is  frequently  "^f^f/f/^"  '  J'";L*^ 
this  case  it  does  not  embrace  the  anchor,  but  goes  through  a  hole  made  m  the  square, 

which  is  swelled  out  on  purpose.  _♦•       i  f^  ti,*.  t^nnntrp  •  n  frond  rule 

The  weight  of  anchors  for  different  vessels  is  proportioned  to  the  ^^^"J^^f^^ '^^.^^^/^^ 
bein^  to  mSke  the  anchor  in  hundred  weights  one  twentieth  of  the  "«?l^^/ ?[  ^^^^^JT  ^ 
burden.    Thus  a  ship  of  1000  tons  would  require  a  sheet  anchor  of  50  cwts.    Ships  of 
war  are  provided  with  somewhat  heavier  anchors.  Piner's  na- 

Several  new  forms  and  constructions  of  anchors  were  proposed  under  Mr.  l;»P«y  s  pa 
tent  of  November,  1822,  by  the  adoption  of  which  great  advantages  as  to  sUengUi  were 
anticipated  over  every  other  form  or  construction  previously  made 

The  particular  object  was  to  preserve  such  a  disposition  of  the  fibres  of  the  melaJ  as 
shoiSd  aS  the  greatest  possible  strength;  in  doing  which  the  crossing  or  bend mj  of 
the  fibres  at  the  junctions  of  the  shank,  fiukes,  and  crown,  where  great  streng  h  ^  re- 
quirXh^^  been  avoided  as  much  as  possible,  so  that  the  fibres  are  not  disturbed  or 

^Kis  respect  most  anchors  are  defective ;  for  in  connecting  the  shanks  to  the  crown- 
pieces,  the  gkin  of  the  metal  is  either  crossed,  or  so  much  curv'ed,  as  to  stram  the  fibre, 
and  consequently  induce  a  weakness  where  the  greatest  strength  is  req^red  And  [or- 
ther,  the  very  considerable  thicknesses  of  metal  which  are  to  be  brought  ^^^^^^'f^ 
contact  by  means  of  the  hammer  in  forging  anchors  upon  the  old  <^«"^^;;»«;; ^^^^^^^^^ 
highly  probable  that  faulty  places  may  be  left  ^vithm  the  mass,  though  they  be  exteni^ 
Siperceptible.  Mr.  PipeJ's  leading  principle  was,  that  the  fibre  of  the  metal  should  run 
nearly  straight  in  aU  the  parts  where  strength  is  particularly  required. 

^-     ^  J-tV.  15  shows  an  anchor  with  one  tumbling  fluke,   wl»cB 

passes  through  the  forked  or  branched  part  of  the  shank.  1^ 
lower  part  of  this  anchor,  answering  to  the  crown,  has  a  spin- 
dle through  it,  upon  which  the  fluke  turns,  and  a  pm  is  there 
Tntroduc^  for  the  purpose  of  confining  the  fl«ke  wto  m  « 
holding  position.  This  shank  is  formed  of  a  sobd  piece  of 
wrought  iron,  the  fibres  of  which  run  straight,  and  at  the 
Trown  holes  are  pierced,  which  merely  bulge  the  ^etal  wUhout 
bendin-  the  fibres  round  so  as  to  strain  them.  The  arm  and 
Suke'  also,  are  formed  of  one  piece  punched  through  ^vithout 
—^  ^         curliAg  or  crossing  the  fibre,  and  the  spindle  which  holds  the 

•    1-1       •       ♦J^;„i,t      "Thic  Qnindle  extends  some  distance  on  each  side 
arm  to  the  crown  is  likewise  straight.     1  hLS  spmaie  exxeims  »« 

that  side  which  is  nearest  the  ground,  and  wiU  there  be  ready  to  take  hold  when  me 
anchor  is  drawn  forward.  .^  ^^^^^^^  ^^^^^^  ^^^  r^./Tt^\^i 

sU-htlf  varied  in  form  from  the  last.    In  this  the  forked  part 
of  Uie  shank  is  closer  than  in  the  former,  and  there  are  two 
arms  or  flukes  connected  to  the  crown^pieces,  of  «f  ^]^^1,;;^^^ 
into  its  holding  position  as  the  anchor  comes  to  the  ground 
and  is  held  at  its  proper  angle  by  the  other  fluke  stoppmg 

'^^F?g.M6%t;res;nts  another  variation  m  the  form  of  these 

improved  anchors,  having  two  tumbling  flukes,  which  are  ^A 

intended  to  take  hold  of  the  ground  at  the  same  t"ne     The 

diank  is  here,  as  before,  made  without  crossing  j^e  gram  of  the  --,  and^the^e^e^  for 

admitting  the  bolt  at  the  crown  and  at  *^%s^%^^.,^%P^^^^^°^  i^  introduced  at 

"■^r  n'tas^'a  shank  without  any  fork,  but  formed  ^raight  t''™»S»'°f .;  »'-,f  "i;^, 

^iX^i'irtoihrs;!^^^^^^^^^ 

made  of  straight  lengths  otmeta^^^^^^  ^^  ^^^  .^  ^^^^ 

injured  by  c^^os^-f  l^*,'^^'.^'^'^^^  Unes  so  that  the  fibres  will  not  be  altered,  and  the 
solid  piece,  and  finished  insraightM  ^^^  .^  ^^^  iniprovement 

^cSr  Ve^set\^o^s,S^gmad'^^  a  great  advantage  to  the 


67 


=1I=3P 


workman  to  execute  each  part  perfectly ;  for  he  will  not  have  such  heavy  weights  to  lift 
when  hot,  which  will  render  these  anchors  much  stronger,  with  less  weight ;  and  if  any 
accident  should  happen  to  them,  any  part  may  be  taken  separate  from  the  others  to  be 
repaired,  and  several  of  those  parts  of  the  anchor  which  may  be  likely  to  break  may  be 
carried  on  board,  in  case  of  accident.  This  anchor  is  so  contrived  that  one  of  thirty 
hundred  weight  may  be  taken  to  pieces  and  put  together  again,  by  one  man,  in  twenty 
minutes ;  it  may  also  be  dismounted,  and  stowed  in  any  part  of  the  ship,  in  as  little  room 
as  straight^rs  of  iron,  and  speedily  put  together  again. 

The  anchor  (Jig.  18)  patented  by  Mr.  Brunton,  in  February, 
1822,  has  its  stock  introduced  at  the  crown  part,  for  the  purpose 
of  turning  it  over  into  a  holding  position.  The  shanlc  is  perfora- 
ted through  the  solid,  in  two  places,  with  elliptical  apertures,  for 
the  purpose  of  giving  it  a  greater  stability,  and  more  efleclually 
resisting  the  strain  to  which  the  anchor  may  be  subjected.  The 
stock  is  a  cylindrical  iron  rod,  held  at  its  extremities  by  lateral 
braces,  which  are  bolted  to  the  shank. 

^  f'^S-  18  shows  the  form  of  the  anchor.  The  shank  is  seen 
upright,  with  one  of  the  flukes  projecting  in  its  front;  the  horizontal  iron  stock  is  at 
bottom  ;  and  the  oblique  braces  are  bolted  to  both  shank  and  stock.  The  ends  of  the 
stock,  from  the  shouId«^,  are  formed  dove-tailed,  and  oval  in  the  vertical  direction,  and 

are  protruded  through  apertures  in  the  bra- 
ces, also  oval,  but  in  the  horizontal  direction, 
and  counter  sunk.  When  the  ends  of  the 
stock  have  been  thus  introduced  through  the 
holes,  the  braces  are  securely  bolted  to  the 
shank,  the  ends  of  the  stock  are  then  spread, 
by  hammering  into  the  counter-sunk  holes 
of  the  braces,  and  by  that  means  they  are 
made  firm. 

An  anchor  of  this  description  is  consider- 
ed by  the  patentee  to  possess  considerable 
advantage,  particularly  in  point  of  stability, 
over  the  ordinary  construction  of  anchors, 
and  is  economical,  inasmuch  as  a  less  weight 
of  metal  will  give,  upon  this  plan,  an  equal 
degree  of  strength. 

An  ingenious  form  of  anchor  was  made 
the  subject  of  a  patent,  by  Lieutenant  Rodg- 
ers,  of  the  Royal  NavT,  in  1828,  and  was 
afterwards  modified  by  him  in  a  second  pa- 
tent, obtained  in  August,  1829.  The  whole 
of  the  parts  of  the  anchor  are  to  be  bound 
together  by  means  of  iron  bands  or  hoops, 
in  place  of  bolts  or  pins. 

Fig,  19  is  a  side  view  of  a  complete 

anchor,    formed    upon    his    last    improved 

construction,   and  Jig.  20,   a   plan   of   the 

same;  fig.  21,   an  end  view  of  the  crown 

and   flukes,    or    arms;    Jig.    22    represents 

the    two    principal    iron    plates,    a,   a,  of 

which  the  shank  is  constructed,  but  so  as  to  form  parts  of  the  stump  arms  to  which  the 

flukes  are  to  be  connected. 

Pi®  7°^  ^^^^^  ^  ^  ^^  "^^^^^  ^o  the  stump  piece,  c,  c.  Jig.  22,  as  well  as  to  the 
end  I  of  the  centre  piece  h  A,  and  the  scarfs  m  m  are  to  be  cut  'to  receive  the  arms  or 
flukes.  Previously,  however,  to  uniting  the  arms  or  flukes  with  the  stump  arms,  the 
crown  and  throat  of  the  anchor  are  to  be  strengthened,  by  the  application  of  the  crown 
slabs  «  Ti,/tg.  22,  which  are  to  be  welded  upon  each  side  of  the  crown,  overlapping  the 
end  of  the  pillar  /i,  and  the  throat  or  knees  of  the  stump  arms  and  the  crown  piece.  The 
slump  arms  are  then  to  be  strengthened  in  a  similar  manner,  by  the  thin  flat  pieces  p  p 
which  are  to  be  welded  upon  each  side.  The  palms  are  united  to  the  flukes  in  the 
usual  way  and  the  flukes  are  also  united  to  the  stump  arms  by  means  of  the  long  scarfs 
m  m.  When  the  shank  of  the  anchor  has  been  thus  formed,  and  united  with  the  flukes, 
the  anchor  smith's  work  may  be  said  to  be  complete. 

Another  of  the  improvements  in  the  construction  of  anchors,  claimed  under  this 
patent,  consists  m  a  new  method  of  affixing  the  stock  upon  the  shank  of  the  anchor, 
rncw!'.n^l'^o.  '^.  the  following  manner  :  in  Jig.  20,  the  stock  is  shown  affixed  to  the 
anchor,  m^g.  23  it  is  shown  detached.    It  may  be  made  either  of  one  or  two  pieces 


dita 


IIM  i 


n 


ii         ', 


W  t 


'  I 


68 


AimEALING. 


of  timber,  as  may  be  found  most  convenient.  It  is,  however,  to  be  observed,  that  the 
stock  is  to  be  completed  before  fitting  on  to  the  shank.  After  the  stock  is  shaped,  a 
hole  is  to  be  made  through  the  middle  of  it,  to  fit  that  part  of  the  shank  to  which  it  is 
to  be  aflixed.  Two  stock  plates  are  then  to  be  let  in,  one  on  each  side  of  the  stock, 
and  made  fast  by  counter  sunk  nails  and  straps,  or  hoops ;  other  straps  or  hoops  of 
iron  are  also  to  be  placed  round  the  stock,  as  usual. 

In  place  of  nuts,  formed  upon  the  shank  of  the  anchor,  it  is  proposed  to  secure  the 
stock  by  means  of  a  hoop  and  a  key,  shown  above  and  below  j,  mjig.  20.  By  thia 
contrivance,  the  stock  is  prevented  from  going  nearer  to  the  crown  of  the  anchor  than 
it  ought  to  do,  and  the  key  prevents  it  from  sliding  towards  the  shackle. 

Since  fitting  the  stock  to  the  shank  of  an  anchor,  by  this  method,  prevents  the  use 
of  a  ring,  as  in  the  ordinary  manner,  the  patentee  says  that  he  in  all  cases  substitutes 
a  shackle  for  the  ring,  and  which  is  all  that  is  required  for  a  chain  cable ;  but,  when 
a  hempen  cable  is  to  be  used,  he  connects  a  ring  to  the  usual  shackle,  by  means  of  a 
joining  shackle,  as  in  Jigs.  19  and  20. 

Mr.  Rodgers  proposes  under  another  patent,  dated  July,  1833,  to  alter  the  size  and 
form  of  the  palms  ;  having  found  from  experience  that  anchors  with  small  palms  will 
not  only  hold  better  than  with  large  ones,  but  that  the  arms  of  the  anchor,  even  with 
out  any  palms>  have  been  found  to  take  more  secure  hold  of  the  ground  than  anchoi*8 
of  the  old  construction,  of  similar  weight  and  length.  He  has,  accordingly,  fixed 
upon  one-fifth  of  the  length  of  the  arm,  as  a  suitable  proportion  for  the  Ungth  or 
depth  of  the  palm.     He  makes  the  palms,  also,  broader  than  they  are  long  or  deep. 

ANILINE.  An  organic  compound,  which  may  be  procured  in  several  ways  :  1, 
•when  isatine  (see  Indigo)  is  fused  with  solid  hydrate  of  potash ;  2,  when  to  an 
alcoholic  solution  of  benzine  a  little  zinc  and  muriatic  acid  is  added :  but  it  is  obtained 
best  from  coal  tar,  which  is  to  be  distilled  in  a  large  iron  retort,  and  the  successive 
products  to  be  separately  received,  especially  the  latter  and  denser  ones.  This  heavy 
tar-oil  is  to  be  strongly  agitated  along  with  muriatic  acid  in  a  glass  globe.  The  acid 
solution  contains  the  aniline,  which,  being  of  an  alkaline  nature,  is  called  a  volatile 
base.  It  must  be  subjected  to  an  operose  process  of  purification,  with  milk  of  lime, 
<tc,  too  complex  to  be  detailed  here,  as  no  useful  application  of  it  in  the  arts  has 
hitherto  been  made.  Dr.  Hofmann  has  written  many  elaborate  papers  upon  aniline, 
and  its  saline  combinations. 

ANI]yrfl.  A  resin  of  a  pale  brown  yellow  color,  transparent  and  brittle.  It 
exudes  from  the  courbaril  of  Cayenne,  a  tree  which  grows  also  in  various  parts  of 
South  America.  It  occurs  in  pieces  of  various  sizes,  and  it  often  contains  so  many 
insects  belonging  to  living  species,  as  to  have  merited  its  name,  as  being  animateo. 
It  contains  about  a  fifth  of  one  per  cent,  of  a  volatile  oil,  which  gives  it  an  agreeable 
odor.  Alcohol  does  not  dissolve  the  genuine  anim^,  as  I  have  ascertained  by  care- 
ful experiments ;  nor  does  caoutchoucme,  but  a  mixture  of  the  two,  in  equal  parts, 
softens  it  into  a  tremulous  jelly,  though  it  will  not  produce  a  liquid  solution.  When 
reduced  to  this  state,  the  insects  can  be  easily  picked  out,  without  injury  to  their 
most  delicate  parts. 

The  specific  gravity  of  the  different  specimens  of  anim6  which  I  tried  varied  from 
1*054  to  1*057.  When  exposed  to  heat,  in  a  glass  retort  over  a  spirit  flame,  it  softens, 
and,  by  careful  management,  it  may  be  brought  into  liquid  fusion,  without  discoloura- 
tion. It  then  exhales  a  few  white  vapors,  of  an  ambrosiacal  odor,  which  being 
condensed  in  water,  and  the  liquid  being  tested,  is  found  to  be  succinic  acid. 
Author. 

It  is  extensively  used  by  the  varnish-makers,  who  fuse  it  at  a  pretty  high  heat,  and 
in  this  state  combine  it  with  their  oils  or  other  varnishes. 

ANKER.     A  liquid  measure  of  Amsterdam,  which  contains  32  gallons  English. 

ANNEALING  or  NEALING.  {Le  recuit,  Fr. ;  chs  anlassen.  Germ.)  A  process 
by  which  glass  is  rendered  less  frangible ;  and  metals,  which  have  become  brittle, 
either  in  consequence  of  fusion  or  long-continued  hammering,  are  again  rendered 
malleable.  When  a  glass  vessel  is  allowed  to  cool  immediately  after  being  made, 
it  will  often  sustain  the  shock  of  a  pistol-bullet,  or  any  other  blunt  body  falling 
into  it  from  a  considerable  height ;  while  a  small  splinter  of  flint,  or  an  angular 
fragment  of  quartz,  dropped  gently  into  it,  makes  it  sometimes  immediately,  some- 
times after  a  few  minutes,  fly  to  pieces  with  great  violence.  This  extreme  fragility 
is  prevented  by  annealing,  or  placing  the  vessels  in  an  oven  where  they  take 
several  hours  or  even  some  d^s  to  cool.  Similar  phenomena  are  exhibited  in  a 
higher  degree  by  glass-tears,  or  Frince  Rupert's  drops.  They  are  procured  by  letting 
drops  of  melted  glass  fall  into  cold  water.  Their  form  resembles  that  of  a  pear, 
rounded  at  one  extremity,  and  tapering  to  a  very  slender  tail  at  the  other.  If  a 
part  of  the  tail  be  broken  oflF,  the  whole  drop  flies  to  pieces  with  a  loud  explosion ; 
and  yet  the  tail  of  a  drop  may  be  cut  away  by  a  glass-cutter's  wheel,  or  the  thick  end 


ANNOTTO. 


69 


may  be  struck  smartly  with  a  hammer,  without  the  fear  of  sustaining  any  injury.  When 
heated  to  redness,  and  permitted  to  cool  gradually  in  the  open  air,  they  lose  these  pecu- 
liarities, and  do  not  differ  sensibly  from  common  glass. 

The  properties  of  unannealed  glass  depend  on  a  peculiar  structure,  extending  uni- 
formly through  its  whole  substance ;  and  the  bursting  of  a  glass  drop  by  breaking  off 
the  tail,  or  of  an  unannealed  glass  vessel,  by  dropping  a  piece  of  flint  into  it,  arises  from 
a  crack  being  thus  begun,  which  afterwards  extends  its  ramifications  in  different  direc- 
tions throughout  the  glass. 

When  metals  have  been  extended  to  a  certain  degree  under  the  hammer,  they  become 
brittle,  and  incapable  of  being  further  extended  without  cracking.  In  this  case  the 
workman  restores  their  malleability  by  annealing,  or  heating  them  red-hot.  The 
rationale  of  this  process  seems  to  be,  that  the  hammering  and  extension  of  the  metal 
destroy  the  kind  of  arrangement  which  the  particles  of  the  metal  had  previous  to  the  ham- 
mering ;  and  that  the  anneeding,  by  softening  the  metal,  enables  it  to  recover  its  original 
structure. 

Of  late  years  a  mode  has  been  discovered  of  rendering  cast  iron  malleable,  without 
subjecting  it  to  the  action  of  puddling.  The  process  is  somewhat  similar  to  that  em- 
ployed in  annealing  glass.  The  metal  is  kept  for  several  hours  at  a  temperature  a  little 
below  its  fusing  point,  and  then  allowed  to  cool  slowly.  In  this  manner  vessels  are 
made  of  cast  iron  which  can  sustain  considerable  violence,  without  bemg  broken.  See 
Steel,  softening  of. 

ANNOTTO.  (Rocouy  or  roucou,  Fr. ;  Orleans,  Germ.)  A  somewhat  dry  and  hard  paste, 
brown  without,  and  red  within.  It  is  usually  imported  in  cakes  of  two  or  three  pounds 
weight,  wrapped  up  in  leaves  of  large  reeds,  packed  in  casks,  from  America,  where  it  is 
prepared  from  the  seeds  of  a  certain  tree,  the  bixa  orellana,  of  Linnseus. 

The  pods  of  the  tree  being  gathered,  their  seeds  are  taken  out  and  bruised ;  they  are 
then  transferred  to  a  vat,  which  is  called  the  steeper,  where  they  are  mixed  with  as  much 
water  as  covers  them.  Here  the  substance  is  left  for  several  weeks,  or  even  months ; 
it  is  now  squeezed  through  sieves  placed  above  the  steeper,  that  the  water  containing 
the  coloring  matter  in  suspension  may  return  into  the  vat.  The  residuum  is  preserved 
under  the  leaves  of  the  anana  (pine-apple)  tree,  till  it  becomes  hot  by  fermentation.  It 
is  again  subjected  to  the  same  operation,  and  this  treatment  is  continued  till  no  more 
color  remains. 

The  substance  thus  extracted  is  passed  through  sieves,  in  order  to  separate  the 
remainder  of  the  seeds,  and  the  color  is  allowed  to  subside.  The  precipitate  is  boiled 
in  coppers  till  it  be  reduced  to  a  consistent  paste ;  it  is  then  suffered  to  cool,  and  dried  in 
the  shade. 

Instead  of  this  long  and  painful  labor,  which  occasions  diseases  by  the  putrefaction  in- 
duced, and  which  aflbrds  a  spoiled  product,  Leblond  proposes  simply  to  wash  the  seeds  of 
innotto  till  they  be  entirely  deprived  of  their  color,  which  lies  wholly  on  their  surface; 
to  precipitate  the  color  by  means  of  vinegar  or  lemon  juice,  and  to  boU  it  up  in  the  ordi- 
•lary  manner,  or  to  drain  it  in  bags,  as  is  practised  with  indigo. 

The  experiments  which  Vauquelin  made  on  the  seeds  of  annotto  imported  by  Leblond, 
confirmed  the  efficacy  of  the  process  which  he  proposed ;  and  the  dyers  ascertained  that 
the  annotto  obtained  in  this  manner  was  worth  at  least  four  times  more  than  that  of  com- 
merce ;  that,  moreover,  it  was  more  easily  employed ;  that  it  required  less  solvent ;  that 
•t  gave  less  trouble  in  the  copper,  and  furnished  a  purer  color. 

Annotto  dissolves  better  and  more  readily  in  alcohol  than  in  water,  when  it  is  intro- 
.luced  into  the  yellow  varnishes  for  communicating  an  orange  tint. 

The  decoction  of  annotto  in  water  has  a  strong  peculiar  odor,  and  a  disagreeable 
taste.  Its  color  is  yeUo wish- red,  and  it  remains  a  little  turbid.  An  alkaline  solution 
renders  its  orange-yellow  clearer  and  more  agreeable,  while  a  small  quantity  of  a  whitish 
substance  is  separated  from  it,  which  remains  suspended  in  the  liquid.  If  annotto  he 
boiled  m  water  along  with  an  alkali,  it  dissolves  much  better  than  when  alone,  and  the 
liquid  has  an  orange  hue. 

The  acids  form  with  this  liquor  an  orange-colored  precipitate,  soluble  in  alkalies. 
Which  communicate  to  it  a  deep  orange  color.  The  supernatant  liquor  retains  only  a 
pale  yellow  hue.  r  ^  j 

When  annotto  is  used  as  a  dye,  it  is  always  mLxed  witti  alkali,  which  facilitates  its 
solution  and  gives  it  a  color  inclining  less  to  red.  The  annotto  is  cut  in  pieces,  and 
f K  V  A  ^^"^^  instants  in  a  copper  with  its  own  weieht  of  crude  pearl  ashes,  provided 
ine  shade  wanted  do  not  require  less  alkali.  The  cloths  may  be  thereafter  dved  in  this 
Dam,  either  by  these  ingredients  alone,  or  by  adding  others  to  modify  the  color;  but  an- 
notto is  seldom  used  for  woollen,  because  the  colors  which  it  gives  are  too  fugitive,  and 
may  be  obtained  by  more  permanent  dyes.  Hellot  employed  it  to  dye  a  stuff,  prepared 
wuh  alum  and  tartar;  but  the  color  acquired  had  little  permanence.     It  is  ahnost  solely 


'  I 


^» 

\ 

1 

< 

1 

1 

i 

i 

70 


ANTHRACITE. 


For  silks  intended  to  become  aurora  and  orange,  it  is  sufficient  to  scour  them  at  the 
rale  of  20  per  cent,  of  soap.  When  Ihey  have  been  well  cleansed,  they  are  immersed 
in  a  bath  prepared  with  water,  to  which  is  added  a  quantity  of  alkaline  solution  of  an- 
notto,  more  or  less  considerable  according  to  the  shade  that  may  be  wanted.  This  bath 
should  have  a  mean  temperature,  between  that  of  tepid  and  boiling  water. 

When  the  silk  has  become  uniform,  one  of  the  hanks  is  taken  out,  washed,  and  wrung, 
to  see  if  the  color  be  sufficiently  full ;  if  it  be  not  so,  more  solution  of  annotto  is  added, 
and  the  silk  is  turned  again  round  the  sticks  :  the  solution  keeps  without  alteration. 

When  the  desired  shade  is  obtained,  nothing  remains  but  to  Wash  the  silk,  and  give  it 
two  beetlings  at  the  river,  in  order  to  free  it  from  the  redundant  annotto,  which  would 
injure  the  lustre  of  the  color. 

When  raw  silks  are  to  be  dyed,  those  naturally  white  are  chosen,  and  dyed  in  the  an- 
notto bath,  which  should  not  be  more  than  tepid,  or  even  cold,  in  order  that  the  alkali 
may  not  attack  the  gum  of  the  silk,  and  deprive  it  of  the  elasticity  which  it  is  desirable 
for  it  to  preserve. 

What  has  been  now  said  regards  the  silks  to  which  the  aurora  shades  are  to  to  be  given  ; 
but  to  make  an  orange  hue,  which  contains  more  red  than  the  aurora,  it  is  requisite, 
after  dyeing  with  annotto,  to  redden  the  silks  with  vinegar,  alum,  or  lemon  juice.  The 
acid,  by  saturating  the  alkali  employed  for  dissolving  the  annotto,  destroys  the  shade  of 
yellow  that  the  alkali  had  given,  and  restores  it  to  its  natural  color,  which  inclines  a 
good  deal  to  red. 

For  the  deep  shades,  the  practice  ai  Paris,  as  Macquer  informs  us,  is  to  pass  the  silks 
through  alum;  and  if  the  color  be  not  red  enough,  they  are  passed  through  a  faint  bath 
of  brazil  wood.  At  Lyons,  the  dyers  who  use  carthamus,  sometimes  employ  old  laths 
of  this  ingredient  for  dipping  the  deep  oranges. 

When  the  orange  hues  have  been  reddened  by  alum,  they  must  be  washed  at  the  river ; 
but  it  is  not  necessary  to  beetle  them,  unless  the  color  turns  out  too  red. 

Shades  may  be  obtained  also  by  a  single  operation,  which  retain  a  reddish  tint,  em- 
ploying for  the  annotto  bath  a  less  proportion  of  alkali  than  has  been  pointed  out. 

Guhliche  recommends  to  avoid  heat  in  the  preparation  of  annotto.  He  directs  it  to  be 
placed  in  a  glass  vessel,  or  in  a  glazed  earthen  one;  to  cover  it  with  a  solution  of  pure 
alkali ;  to  leave  the  mixture  at  rest  for  24  hours ;  to  decant  the  liquor,  filter  it,  and  add 
water  repeatedly  to  the  residuum,  leaving  the  mixture  each  time  at  rest  for  two  or  three 
days,  till  the  water  is  no  longer  colored ;  to  mix  all  these  liquors,  and  preserve  the  whole 
for  use  in  a  well-stopped  vessel. 

He  macerates  the  silk  for  12  hours  in  a  solution  of  alum,  at  the  rate  of  an  eighth  of 
this  salt  for  one  part  of  silk,  or  in  a  water  rendered  acidulous  by  the  aceto-citric  acid 
above  described ;  and  he  wrings  it  well  on  its  coming  out  of  this  bath 

Silk  thus  prepared  is  put  into  the  annotto  bath  quite  cold.  It  is  kept  in  agitation 
there  till  it  has  taken  the  shade  sought  for ;  or  the  liquor  may  be  maintained  at  a  heat 
far  below  ebullition.  On  being  taken  out  of  the  bath,  the  silk  is  to  be  washed  and  dried 
in  the  shade. 

For  lighter  hues,  a  liquor  less  charged  with  color  is  taken  ;  and  a  little  of  the  acid 
liquid  which  has  served  for  the  mordant  may  be  added,  or  the  dyed  silk  may  be  passed 
through  the  acidulous  water. 

We  have  seen  the  following  preparation  employed  for  cotton  velvet : — one  part  of 
quicklime,  one  of  potash,  two  of  soda. 

Of  these  a  ley  is  formed,  in  which  one  part  of  annotto  is  dissolved ;  and  the  mixture 
is  boiled  for  an  hour  and  a  half.  This  bath  affords  the  liveliest  and  most  brilliant  auro- 
ras. The  buff  (chamois)  fugitive  dye  is  also  obtained  with  this  solution.  For  this  pur- 
pose only  a  little  is  wanted ;  but  we  must  never  forget,  that  the  colors  arising  from  an- 
notto are  all  fugitive. 

Dr.  John  found  in  the  pulp  surrounding  the  unfermented  fresh  seeds,  which  are  about 
the  size  of  little  peas,  28  parts  of  coloring  resinous  matter,  26*5  of  vegetable  gluten,  20 
of  ligneous  fibre,  20  of  coloring  extractive  matter,  4  formed  of  matters  analogous  to  vege- 
table gluten  and  extractive,  and  a  trace  of  spicy  and  acid  matters. 

The  Gloucestershire  cheese  is  colored  with  annotto,  in  the  proportion  of  one  cwt.  to 
an  ounce  of  the  dye. 

When  used  in  calico-printing,  it  is  usually  mixed  with  potash  or  ammonia  and  starch. 

It  is  an  appropriate  substance  for  tinging  varnishes,  oils,  spirits,  &c. 

TTie  following  statement  gives  an  account  of  the  quantities  imported  and  exported 
with  the  nett  revenue,  during  the  following  years: — 

Quantities  imported      .... 

Quantities  exported 

Retained  for  conaumption 

Nett  Revenue  .... 


1841. 

1842. 

1848. 

1844. 

cwt. 

2319 

3271 

3494 

cwt. 

613 

229 

307 

cwt. 

8197 

3847 

2689 

£. 

164 

186 

175 

144 

ANTIMONY. 


71 


ANTHRACITE,  from  avbpai,  coal,  is  a  species  of  coal  found  in  the  transition  rock 
formation,  and  is  often  called  stone  coaL  It  has  a  grayish  black,  or  iron  black  color, 
an  imperfectly  metallic  lustre,  conchoidal  fracture,  and  a  specific  gravity  of  from  14  to 
re,  being,  therefore,  much  denser  than  the  coal  of  the  proper  coal  measures.  It  con- 
sists wholly  of  carbon,  with  a  small  and  variable  proportion  of  iron,  silica,  and  alumina. 
It  is  diflicult  to  kindle  in  separate  masses,  and  burns  when  in  heaps  or  grates  without 
smell  or  smoke,  leaving  sometimes  an  earthy  residuum.  It  has  been  little  explored 
or  worked  in  the  old  world ;  but  is  extensively  used  in  the  United  States  of  America, 
and  has  become  of  late  years  a  most  valuable  mineral  to  that  country,  where  it  is  burned 
in  peculiar  grates,  adapted  to  its  difficult  combustion.  In  Pens^'lvania,  the  anthracite 
coal  formation  has  been  traced  through  a  tract  many  miles  in  width,  and  extending 
across  the  two  entire  counties  of  Luzerne  and  Schuylkill  At  Mauch  Chunk,  upon 
the  Lehigh,  800  men  were  employed  so  far  back  as  1825,  in  digging  this  coal.  In  that 
year  750,000  bushels  were  dispatched  for  Philadelphia.  It  is  worked  there  with  little 
cost  or  labor,  being  situated  on  hills  from  300  to  600  feet  above  the  level  of  the  neighbor- 
ing rivers  and  canals,  and  existing  in  nearly  horizontal  beds,  of  from  1 5  to  40  feet  in  thick- 
ness, covered  by  only  a  few  feet  of  gravelly  loam.  At  Portsmouth,  in  Rhode  Island, 
an  extensive  stratum  of  this  coal  has  been  worked,  with  some  interruptions,  for  20 
years;  and  more  recently  a  mine  of  anthracite  has  been  opened  at  Worcester,  iu  Mas- 
sachusetts, at  the  head  of  the  Blackstone  canal  It  has  been  of  late  employed  iu  South 
Wales  for  smelting  iron,  and  in  a  cupola  blast  furnace. 

ANTIGUGGLER.  A  small  syphon  of  metal,  which  is  inserted  into  the  mouths  of 
casks,  or  large  bottles,  called  carboys,  to  admit  air  over  the  liquor  contained  in  them, 
and  thus  to  facilitate  their  befng  emptied  without  agitation  or  a  guggling  noise. 

ANTIMONY.  {Antimoine,  Fr.;  Spiessglanz,  or  Spiessglass,  Ger.)  The  only  ore  of  this 
metal  found  in  sufficient  abundance  to  be  smelted  is  the  sulphuret,  formerly  called  crude 
antimony.  It  occurs  generally  in  masses,  consisting  of  needles  closely  aggregated,  of  a 
metallic  lustre ;  a  lead-gray  color,  inclining  to  steel-gray,  which  is  unchanged  iu  the 
streak.  The  needles  are  extremely  brittle,  and  melt  even  in  the  flame  of  a  candle,  with 
the  exhalation  of  a  sulphureous  smell  The  powder  of  this  sulphuret  is  very  black,  and 
was  employed  by  women  in  ancient  times  to  stain  their  eyebrows  and  eyelids.  This  ore 
consists  in  100  parts  of  7 2  86  metal,  and  27-14  sulphur.    Specific  gravity  from  4.13  to  4-6. 

The  veins  of  sulphuret  of  antimony  occur  associated  with  gangues  of  quartz,  sulphate 
of  barytes,  and  carbonate  of  lime ;  those  of  Allemont  occur  in  the  numerous  fissures  of 
a  mica  schist^  evidently  primitive.  Of  late  years  very  productive  mines  of  antimony 
have  been  found  m  Borneo,  which  have  furnished  great  importations  to  this  country 

In  treating  the  oar  to  obtain  the  metal,  the  first  object  is  to  separate  the  ean^rue 
which  was  formerly  done  by  filling  crucibles  with  the  mixed  materials,  placing  them 
on  the  hearth  of  an  oven,  and  exposing  them  to  a  moderate  heat.  As  the  sulphuret 
easily  melts  It  ran  out  through  a  hole  in  the  bottom  of  the  crucible  into  a  pot  placed 
beneatli,  and  out  of  the  reach  of  the  fire.  But  the  great  loss  from  breaka^^e  of  the 
crucibles  has  caused  another  method  to  be  adopted.  In  this  the  broken  o^re,  beinff 
sorted,  18  laid  on  the  bottom  of  a  concave  reverberatory  hearth,  wherere  it  is  reduced. 

tigs.  24,  25,  represent  a  wind^rjlame  furnace,  for  the  reduction  of  antimony.    The 

clay  solidly  beat  together, 
and  slopes  from  all  sides  to- 
wards the  middle,  where  it 
is  connected  with  the  orifice 
o,  which  is  closed  with  dense 
coal-ashes ;  b  is  the  air  chan- 
nel up  through  the  bridge ; 
4.1  J  3  .        ^  ,  ^»  the  door  for  introducing 

the  prepared  ore,  and  running  off  the  slags ;  d,  the  bri.ige ;  e,  the  grate ;  /,  the  fire  or  fuel- 
door ;  .7,  the  chimney.  With  2  or  3  cwt.  of  ore,  the  smelting  process  is  completedin  from 
8  to  10  hours  The  nietal  thus  obtained  is  not  pure  enough,  but  must  be  fused  under  coal 
Tn  in  portions  of  20  or  30  pounds,  in  crucibles  placed  upon  a  reverberatory  hearth. 
To  obtain  antimony  free  from  iron,  it  should  be  fused  with  some  antimonic  oxide 
Lntl^n  ^'^  ;,  ^  TaI  ^\l  '""^^  ;?  ""^'^'^^^  ^^^  separated.     The  presence  of  arsenic  in 

Wow  S ''  ^^  kI' ^  7  *^^  ?f '^'^  .'°'^."'  ^"^'^^^^  ^y  «^«li  ^°  a"«y  ^he^  heated  at  the 
blow-pipe;  or,  better,  by.igmting  it  with  nitre  in  a  crucible;  in  which  case  insoluble 

W^irS!  r^  antimoiuate  of  potash  will  be  formed  along  with  soluble  arseniate, 
^n  Jti  ^t  "^  ''P''?  ^^^  ^'^^'''^^'  filtered,  and  then  tested  with  nitrate  of  silver,  will 
afford  the  brown-red  precipitate  characteristic  of  arsenic  acid.  " 

A..mJ  ?'^  ^i^i'i'^'"'  *^^  following  materials  afford,  in  smelting,  an  excellent  pro- 
th«Kh[n'lH"°''''^=  100  parts  of  sulphuret;  60  of  hammel-schlag  (prSoxideof  iron  l?om 

der  Frot  65  Z  70  t"rf  ""f'^  \  t,^  '"  '^.  "^  '^'^'''^''  «^  ''^^ '  ^^^  ^^  ^^  charcoalpo  w- 
aer.   1-  rom  65  to  70  parts  of  metallic  antimony  or  regulus  should  be  obtained.    Glauber 


I 


I 


f     1 

;  * 

1  1 

72 


ANVIL. 


Baits  may  be  used  advantageously  instead  of  soda.     Another  formula  is  100  parts  of 
sulphuret  of  antimony ;  42  of  metallic  iron,  and  10  of  dry  sulphate  of  soda.     The  pm 
duct  thence  is  said  to  be  from  60  to  64  parts  of  metal. 

In  the  works  where  antimonial  ores  are  smelted,  by  means  of  tartar  (argol),  the  alka- 
line scoriae,  which  cover  the  metallic  ingots,  are  not  rejected  as  useless,  for  thev  hold 
a  certain  quantity  of  antimonial  oxide  in  combination ;  a  property  of  the  potash  flux, 
which  is  propitious  to  the  purity  of  the  metal.  These  scorise,  consisting  of  sulphuret 
of  potassium  and  antimonite  of  potash,  being  treated  with  water,  undergo  a  reciprocal 
decomposition ;  the  elements  of  the  water  act  on  those  of  the  sulphuret,  and  the  re- 
sulting alkaline  hydro-sulphuret  re-acts  on  the  antimonial  solution,  so  as  to  form  a 
species  of  kermes  mineral,  which  precipitates.  This  is  dried,  and  sold  at  a  low  price  as 
a  veterinary  medicine,  imder  the  name  of  kermes,  by  the  dry  wav. 

Metallic  antimony,  as  obtained  by  the  preceding  process,  is  the  antimony  of  cora- 
merce,  but  is  not  absolutely  pure;  containing  frequently  minute  portions  of  iron,  lead, 
and  even  arsenic ;  the  detection  and  separation  of  which  belong  to  the  sciences  of  che- 
mistry and  pharmacy ;  but  considerable  purity  may  be  secured  by  fusing  the  metal, 
mixed  with  a  little  of  its  sulphuret  and  some  caroonate  of  soda,  repeatedly  in  a  crucible 
From  100  part«  of  the  impure  metal  in  this  way  94  of  pure  antimony  are  obtained. 
The  addition  of  sulphuret  serves  the  purpose,  making  fluid  compounds  of  the  sul- 
phurets  of  iron,  arsenic,  and  copper,  with  the  soda.  Wohler  purines  antimony  com- 
pletely from  arsenic  (not  from  iron  and  copper),  by  deflagrating  10  parts  of  the  crude 
ore  with  12  of  nitre  and  15  of  carbonate  of  soda;  washes  away  the  arsenic  salt,  and 
then  smelts  the  residuary  antimoniate  of  potash  with  black  flux.  Lead  can  be  sepa- 
rated only  by  the  humid  analysis. 

Antimony  is  a  brittle  metal,  of  a  silvery  white  color,  with  a  tinge  of  blue,  a  lamellar 
texture,  and  crystalline  fracture.  When  heated  at  the  blow-pipe,  it  melts  with  gieat 
readiness,  and  diflfuses  white  vapors,  possessing  somewhat  of  a  garlic  smell.  If  thrown 
in  this  melted  state  on  a  sheet  of  flat  paper,  the  globule  sparkles  and  bursts  into  a 
multitude  of  small  spheroids,  which  retain  their  incandescence  for  a  long  time,  and 
run  about  on  the  paper,  leaving  traces  of  the  white  oxide  produced  during  the  com- 
bustion. When  this  oxide  is  fused  with  borax,  or  other  vitrefying  matter,  it  imparts 
a  yellow  color  to  it.  Metallic  antimony,  treated  with  hot  nitric  acid  in  a  concentrated 
state,  is  converted  into  a  powder,  called  antimonious  acid,  which  is  altogether  insoluble 
in  the  ordinary  acid  menstrua ;  a  property  by  which  the  chemist  can  separate  that  metal 
from  lead,  ii  on,  copper,  bismuth,  and  silver.  According  to  Bergmann,the  specific  gravity 
of  antimony  is  6*86 ;  but  that  of  the  purest  is  6'715.  The  alchemists  had  conceived  the 
most  brilliant  hopes  of  this  metal;  the  facility  with  which  it  is  alloyed  with  gold, 
since  its  fumes  alone  render  this  most  ductile  metal  immediately  brittle,  led  theni  to 
assign  to  it  a  royal  lineage,  and  distinguish  it  by  the  title  of  regulus,  or  the  little  king. 

Its  chief  employment  now  is  in  medicine,  and  in  making  the  alloys  called  type  metal, 
stereotype  metal,  music  plates,  and  Britannia  metal;  the  first  consisting  of  6  of  lead 
and  2  of  antimony ;  the  second  of  6  of  lead  and  1  of  antimony ;  the  third  of  lead,  tin, 
and  antimony ;  and  the  fourth  also  of  lead,  tin,  and  antimony,  with  occasionally  a 
little  copper  and  bismuth. — For  Glass  of  Antimony,  see  Pastes. 

ANTISEPTICS.  Substances  which  counteract  the  spontaneous  decomposition  of  ani- 
mal and  vegetable  substances.  These  are  chiefly  culinary  salt,  nitre,  spices,  and  sugar, 
which  operate  partly  by  inducing  a  change  in  the  animal  or  vegetable  fibres,  and 
partly  by  combining  with  and  rendering  the  aqueous  constituent  unsusceptible  cf  de- 
composition.    See  Provisions,  curing  of,  and  Preserved  Meats. 

ANVIL.  A  mass  of  iron,  having  a  smooth,  and  nearly  flat  top  surface  of  steel; 
upon  which  blacksmiths,  and  various  other  artificers,  forge  metals  with  the  hammer. 
TTie  common  anvil  is  usually  made  of  seven  pieces :  1,  the  core,  or  body ;  2,  3,  4,  5, 
the  four  corner  pieces  which  serve  to  enlarge  its  base ;  6,  the  projecting  end,  which 
has  a  square  hole  for  the  reception  of  the  tail  or  shank  of  a  chisel  on  which  iron  bars 
may  be  cut  through  ;  and  7,  the  beak,  or  horizontal  cone  round  which  rods  or  slips  of 
metal  may  be  turned  into  a  circular  form,  as  in  making  rings.  These  6  pieces  are  welded 
separately  to  the  first,  or  core,  and  then  hammered  into  a  uniform  body.  In  manu- 
facturing large  anvils  two  hearths  are  needed,  in  order  to  bring  each  of  the  two  pieces 
to  be  welded  to  a  proper  heat  by  itself;  and  several  men  are  employed  in  working 
them  together  briskly  in  the  welding  state,  by  heavy  swing  hammere.  The  steel  facing 
is  applied  by  welding  in  the  same  manner.  The  anvil  is  then  hardened  by  heating  it 
to  a  cherry  red,  and  plunging  it  into  cold  water  ;  a  running  stream  being  preferable 
to  a  pool  or  cistern.  The  facing  should  not  be  too  thick  a  plate,  for,  when  such,  it  is 
apt  to  crack  in  the  hardening.  The  face  of  the  anvil  is  now  smoothed  upon  a  grind- 
stone, and  finally  polished  with  emery  and  crocus,  for  all  delicate  purposes  of  art. 

The  blacksmith,  in  general,  sets  his  anvil  loosely  upon  a  wooden  block,  and  in  pre- 
ference on  the  root  of  an  oak.  But  the  cutlers  and  file-makei-s  fasten  their  anvils  tx) 
a  large  block  of  stone ;    which  is  an  advantage,  for  the  more  firmly  and  solidly  this 


ARABLE  LAND. 


78 


tool  is  connected  to  the  earth,  the  more  efficacious  will  be  the  blows  of  the  hammer 
on  any  object  placed  upon  it. 

AQUAFORIIS.  Nitric  acid,  somewhat  dilute,  was  so  named  by  the  alchemists  on 
account  of  its  strong  solvent  and  corrosive  operation  upon  many  mineral,  vegetable, 
and  animal  substances.     See  Nitric  Acid. 

AQIJA  REGIA.  The  name  given  by  the  alchemists  to  that  mixture  of  nitric  and 
muriatic  acids  which  was  best  fitted  to"  dissolve  gold,  styled  by  them  the  king  of  the 
metals.     It  is  now  called  nitro-muriatic  acid. 

AQUA  VIT^  The  name  very  absurdly  given  to  alcohol,  when  used  as  an  intoxi- 
cating beverage.  It  has  been  the  aqua  mortis  to  myriads  of  the  human  race ;  and 
will,  probably,  ere  long,  destroy  all  the  native  tribes  of  North  America  and  Australia. 

ARABLE  LAND  may  be  regarded  with  Thaer  as  consisting  of  one  or  other  of  the 
following  sorts  of  soils : — 


1 

No. 

Clay 
per 

1 

Cent 

■\                                                     f 

74 

2 

1  First  class  of  strong  wheat 

81 

3 

soils 

79 

4 

J 

40 

5 

Rich   light    sand    in    natural 

grass 

14 

6 

Rich  barley  land    - 

20 

7 

Good  wheat  land    - 

58 

8 

Wheat  land     -         -         -         . 

56 

9 

Do.          .... 

60 

10 

m.         -        -        .        . 

48 

11 

Do.          .        .        .        . 

68 

12 

Good  barley  land   -        -        . 

38 

13 

Do.  Second  quality 

33 

14 

Do.    -        -        - 

28 

15 

Oat  land         -         -         .         . 

23| 

16 

Do.      -         -         .         . 

18J 

Sand 

per 

Cent. 


10 

6 

10 

22 

49 
67 
36 
30 
38 
50 
30 
60 
65 
70 
75 
80 


Carb.  of 

Lime 

per  Cent 


H 
4 
4 
36 

10 

3 

2 
12 

a 

ei 

'-a  S 

C  .u 

m    Q 
C    c3 


Hamas 

per 

Cent 


Value. 


11-5 
8-4 
6-5 
4 

27 
10 

4 

2 

2 

2   • 

2 

2 

2 

2 

1-5 

1-5 


100 
98 
96 
90 


78 
77 
76 
70 
65 
60 
60 
50 
40 
30 
20 


Below  this  are  very  poor  lands. 

^ifh^if  If?^  ?a' ^^^  "^^Pu'  ^'  supposed  the  same,  and  the  quality  uniform  to  the 
depth  of  at  least  6  inches ;  the  subsoil  sound,  and  neither  too  wet  nor  too  dry. 

^os.  1,  2,  &  3,  are  alluvial  soils;  and  from  the  division  and  intimate  union  of  the 
humus  are  not  so  heavy  and  stiff  as  the  quantity  of  clay  would  indicate. 

x\o.  4,  18  a  rich  clay  loam,  such  as  is  found  in  many  parts  of  Enijland,  neither  too 
heavy  nor  too  loose;  a  soil  easily  kept  in  heart  by  jucfiJious  cultivation. ' 

co^.  CLV  ^^  ^"^•"''^'  r^  ^"'^  ^^*^P*^^  ^«^  ^^^»"^^»s  and  orchards,  but  not  for 
corii ;  hence  its  comparative  value  can  scarcely  be  given 

Nos  6,  7,  A  8,  are  good  soils.  The  quantity  of  carbonate  of  lime  in  No  8  comnen- 
sates  for  the  smaller  portion  of  humus.  This  land  requires  manure  T^J^Z^IL 
others  below  In  those  from  No.  9,  downwards,  lime  or  marl  wS' be  the  ei  eatest 
improvement     Nos.  15  and  16  are  poor  light  soils,  requiring  clay  and  much  ILnure 

tZZ  f     T  ^*"^%^'11  pay  ^'^e  cost  of  judicious  cultivation,  aifdHser  value  ' 

fJonnf  It  "'°°'  of  comparative  value,  is  the  result  of  several  years'  carefu"  valua- 
tiori  of  the  returns,  after  labor  and  seed  had  been  deducted.  ^ 

^Ir"  ^fl  '"^  England  contain  more  than  4  or  5  per  cent,  of  humus  even  when  in  a 

Zl'-^.  ^u^i-ouT  u  tfvXn^^'  Tte^eXe^iT^r^^^^  T"  rl^^^::^^ 
bv  comnarino-  N^n«  7  Ar  ft  ^,Vk  ^j  i  ^i^  .^^  ^^  ^^  ^^^^  importance,  as  may  be  seen 
tZr jrsfpp^^^^^     VrZf"  ""^  '-     ''  ^^^«  -  ''  g-<^  q-"ty,  dung  will'soon  give 

evir  rlch^t  m"!?!;^  Tf  H^""*^  -^^  T^'''\?^  ^^^  ^^^^«i'  g^^^tly  affect  its  value.  How- 
wet  ciLv  ll  Z^  '  >  ^'^  ''  ^''^^  ^  ^^^^  1*>'^^  «f  g«o<i  soil  over  a  sharp  gravel  or  a 
her  :id  in  thelTer  cZ^n^^f  ^"^^^  ^^^  ^^  ^^^^  ^«  Parched  fn  dry  wea 
beloam  or  chalk  SinoC^J  A  '"V'  "'^Vt  ^^  ^^^'^  continued  rain.  If  the  subsoil 
subsoiUrof  HttlP  conf nf,^''''^  601  will  be  sufficient.  With  a  foot  of  good  soil,  the 
outlet  The  best  alh?vLTrr'  P^-^^^^^^^  .^  be  dry,  and  the  water  can  find  a  ready 
The  exnosur?  w    »7i  .'  f ''^^pnerally  deep,  the  chalky  shallow.  ^ 

importanTo^^^^^^^^  '^  '^'^1'  «"^  '^'  declivity  ^f  the  ground,  are  very 

gentle  decliXTowa'd^hr^  eqmvalent  to  an  actual  difference  in  the  climate.     A 

adiffe'ren^Sverardt^^^^^^^^^^^ 

different  climates  the  avf  r^t«  lL„f      ^   '  ^^ '"  comparing  the  value  of  similar  lands  in 
Vol.  L  ^    ^""^  ^""^  moisture  in  each  must  be  accurately  known.     A 


11 


H\i 


itti 

.  1%  I 


(  i 


i  ill 


U 


ABABLE  LAND. 


soil  very  fertile  in  the  south  of  Europe  may  be  very  unproductive  in  England ;  and  a  li^hl 
soil  of  some  value  in  the  west  of  Scotland  might  be  absolutely  barren  in  Italy  or  bpain. 
2.   Cultivation  of  the  Soil.-The  better  the  soil,  the  ess  cultivation  it  requires  to  pro^ 
duee  tolerable  crops;  hence,  where  the  land  is  very  rich,  we  find  in  general  a  slovenly 
culture;  where  the  ground  is  less  productive,  more  labor  and  skill  f'f.^VV^}]^ ^^^^ 
Densate  for  the  want  of  natural  fertility.     The  simplest  cultivation  ls  that  of  the  spade 
Fhe  hoe  Ind  the  rake;  and,  on  a  small  Lie,  it  is  the  best:  but  ^P^t^^"^^^^^^^ 
be  carried  to  a  great  extent  without  employing  more  hands  than  can  ^e  spared  fm^^^ 
occuDations    The  plough,  drawn  by  oxen  or  horses,  is  the  chief  instrument  of  tillage,  and 
ra^Te^o  in  all  age^^^^^^    nations  of  which  we  have  any  records     I^  general  lorm  is 
famiHar  to  every  one,  and  requires  no  minute  description.     A  plough  should  as  nauch 
^possible  Se  the  work^one  with  a  spade.     It  should  cut  a  slice  from  the  land 
ry^LoulteT  vertically,  and  by  the  share  horizontally  lift  it  up,  and  turn  it  quite  over 
by  means  of  the  moukl  board;  and  the  art  of  the  ploughman  consists  in  doing  this 
perfectly,  and  with  such  a  depth  and  width  as  suit  the  soil  and  the  intended  purpose. 
L  rich  mellow  soUs  a  ploughe*d  field  should  differ  little  from  a  garden  dug  with  a  spade 
In  tenacious  soils,  the  slice  will  be  continued  without  breaking,  especially  ^f  bound  by 
the  fibres  and  roots  of  plants ;    the  whole  surface  will  be  turned  over  and^he  roots 
exposed  to  the  air.     It  is  of  great  consequence  that  each  slice  be  of  the  same  width, 
and  thfckness,  and  the  sides  of  it  perfectly  straight  and  parallel.     Tlie  plane  of  the  coul^ 
ter  must  be  perfectly  vertical,  and  that  of  the  share  horizontal,  in  order  that  tbe  bottom 
of  the  furrow  may  be  level,  without  hollows  or  baulks,  which  are  irregularities  produced 
by  the  rising  or  sinking  of  the  plough,  or  inclining  it  to  either  side      The  ancients 
were  very  particular  in  this  re/pect,  and  recommended  sounding  the  earth  with  a 
Tarp  staLrto  ascertain  whether  the  ploughman  had  done  his  duty.     There  are  van- 
ous  modes  of  ploughing  land,  either  quite  flat,  or  in  lands  or  stitches  as  they  are  cabled 
in  England,  and  in  Scotland  riggs ;  that  is,  in  portions  of  greater  or  less  width,  with  a 
double  furrow  between  them,  somewhat  like  beds  in  a  garden     S<>°L«f^X^^7«"^f^ 
are  set  up  a-ainst  each  other,  which  is  called  ridg.ng  or  bonting.    The  land,  then,  is 
entire  ylaid'in  ridges  and  deep  furrows,  by  which  it  is  more  exposed  to  the  influence 
of  the  atmosphere  and  kept  drier.     This  is  generally  done  before  winter,  especially  in 
stiff  wet  soils      Sometimes  two  or  more  ridges  are  made  on  each  side  forming  narrow 
stitches     When  the  ground  is  to  be  ploughed  without  bemg  laid  in  ands  or  st  tches, 
and  all  the  ridges  inclined  one  way,  the  mould  board  of  the  plough  is  shifted  at  each 
turn  from  one  side  to  the  other.     The  plough  which  admits  of  this  is  called  a  turn^est 
SoLTand  is  in  general  use  in  Kent  and  in  many  parts  of  the  Continent,  where  the 
Sil  is  dry  and  the  land  not  too  moist.     In  most  other  situations  the  ground  is  laid 
n"and^the  mould  board  of  the  plough  is  fixed  on  the  right  side      When  grass 
and  or  stubble  is  ploughed,  care  must  be  taken  to  bury  the  gross  and  weeds  com- 
pletely;   and  the  slice  cut  off  by  the  plough  must  be  turned  fjer  entirely  which  is 
best  done  by  making  the  width  of  the  furrow  greater  than  the  depth.     When  the 
gr^s  and  we^eds  are  rotten,  and  the  ground  is  ploughed  to  pulverize  it,  ^  n^-^  <^eeP 
furrow  is  best.     The  earth  ploughed  up  is  laid  against  the  side  of  the  preceding  ridge 
whiclTforms  a  small  furrow  between  the  tops  of  the  ridges,  well  adapted  for  the  seed 

to  lodge  in,  and  to  be  readily  covered  with  the  harrows.  ,         , 

Nothin-  has  divided  both  practical  and  theoretical  agriculturists  more  than  the 
question  whether  the  land  should  be  ploughed  deep  or  shallow ;  but  a  very  slight  at- 
tention to  the  purposes  for  which  land  is  ploughed,  and  to  the  nature  of  the  soi^  wi 
readily  reconcile  these  apparently  contradictory  opinions.  A  deep,  rich,  and  stiff  soil 
can  ne^ver  be  moved  too  much  nor  too  deep.  Deep  ploughing  brings  up  rich  earth 
admits  the  air  and  water  readily,  and  gives  room  for  the  roots  to  shoot,  while  the  rich 
cXact  soil  affords  moisture  and  nourishment.  Wherever  trees  are  to  be  plante<^ 
thrground  should  be  stirred  as  deep  as  possible,  even  in  a  p<K,r  soil.  For  grass  and 
corif thb  is  not  always  prudent;  their  roots  seldom  go  above  3  or  4  inches  deep;  and 
if  they  find  sufficient  moisture  and  humus,  they  require  httle  more  depth. 

Whenever  the  soil  below  a  certain  depth  is  of  an  mfer.or  quality  there  can  be  no  use 
in  bringing  it  up ;  and  where  the  soil  is  light  and  porous,  the  bottom  had  much  better 
not  be  broken.  Norfolk  farmers  know  this  well,  and  are  very  careful  not  to  break  the 
Ian  as  they  call  it,  in  their  light  lands.  ITiis  pan  is  formed  by  the  pressure  of  the  so  e 
^f  the  plough  and  the  tread  of  the  horses,  and  opposes  a  useful  bank  to  the  too  rapid 
filtration  of  the  water.  It  lies  from  5  to  8  inches  below  the  surface.  If  it  is  broken, 
the  manure  is  washed  down  into  the  light  subsoil,  and  the  crop  suffers,  especially  when 
sheep  have  been  folded,their  dung  being  very  soluble.  In  such  soils  an  artificial  pan  may 
be  f?rSy  the /anrf-;rm.r  or  press-drill.  This  instrument  consists  of  two  v-ery  heavy 
ca.tiW  wheels  with  angular  edges,  set  on  an  axle,  at  a  distance  from  each  other  equal 
Tthe  width  ofthe  furrows,  and  a  lighter  wheel  to  keep  the  instrument  vertical 
It  L  drawn  by  a  horse  immediately  after  the  plough,  pressing  two  fuiTows  at  onc^ 


ARABLE  LAND. 


76 


and  going  twice  over  each  furrow.  It  leaves  the  land  in  regular  drills ;  and  the  seed 
sown  by  hand  falls  into  the  bottom  of  the  drills,  and  is  covered  by  the  harrows.  Whea 
the  plants  come  up,  they  appear  in  regular  parallel  rows. 

The  great  object  in  ploughing  land  is  to  divide  it,  expose  ever}'  part  of  it  to  the  infla- 
euce  of  the  elements,  and  destroy  every  plant  or  weed  but  those  which  are  sown  in  it.  To 
do  this  perfectly  requires  several  ploughings,  with  certain  intervals;  and  during  that 
time  no  crop  can  be  upon  the  land.  This  is  the  real  use  of  fallow8,and  not, as  was  once  sup- 
posed, to  allow  the  land  to  rest ;  on  the  contrary,  it  ought  then  to  have  the  least  repose. 

Where  the  soil  is  good,  with  a  porous  subsoil,  the  greatest  care  should  be  taken  not 
to  go  too  deep;  but  where  the  subsoil  is  compact  and  impervious  to  water,  but  not 
wet  for  want  of  outlet  or  draining,  it  is  useful  to  stir  the  soil  to  a  great  depth,  but 
without  bringing  it  to  the  surface,  which  may  be  done  by  a  plough  without  a  mould 
board  following  a  common  plough  in  the  same  furrow,  "this  is  an  excellent  mode  of 
draining;  and  at  the  same  time  keeping  a  reservoir  of  moisture,  which  in  dry  wea- 
ther ascends  in  vapors  through  the  soil  and  refreshes  the  roots. 

The  mode  in  which  the  soil  is  prepared  most  perfectly  for  the  reception  of  the  seed 
is  best  shown  by  following  the  usual  operations  on  fallows.  After  the  harvest,  the 
plough  is  set  to  work,  and  the  stubble  ploughed  in.  The  winter's  frost  and  snow  mel- 
low It,  while  the  stubble  and  weeds  rot  below.  In  spring,  as  soon  as  the  weather 
permits,  it  is  ploughed  again,  the  first  ridges  being  turned  over  as  they  were  before. 
This  completes  the  decomposition  of  the  roots  and  weeds.  It  is  then  stirred  with 
harrows  or  other  instruments,  which  tear  up  the  roots  which  remained ;  and  some  of 
these  not  being  easily  destroyed,  are  carefully  gathered  and  burnt,  or  put  in  a  heap 
to  ferment  and  rot,  a  portion  of  quicklime  being  added.  Another  ploughing  and  stir- 
ring follows,  at  some  interval,  till  the  whole  ground  is  mellow,  pulverized,  and  free 
from  weeds ;  manure  is  put  on  if  required,  and  immediately  spread  and  ploughed  in ; 
the  land  is  then  prepared  for  the  seed. 

There  is  no  method  yet  found  out  of  ascertaining  the  comparative  state  of  land 
which  has  been  exhausted.  It  would  be  a  discovery  well  worth  the  attention  of  mo- 
dern chemists,  who  have  made  such  progress  lately  in  the  analysis  of  vegetable  sub- 
stances, and  would  be  invaluable  to  farmers  and  proprietors  of  land.  In  the  mean- 
time the  nature  of  the  weeds  which  abound  on  the  land  will  give  some  clue  to  its  state  • 
and  an  experienced  person  will  collect  from  various  minute  appearances  in  the  soil 
whether  it  has  been  fairly  managed  or  exhausted.  It  is  in  general  more  advantageous 
to  take  a  farm  m  a  district  with  which  you  are  well  acquainted.  It  will  be  a  great 
advantage  if  you  have  had  an  opportunity  of  seeing  the  land  at  all  times,  observing  it 
in  different  seasons  and  states  of  the  weather,  and  especially  of  seeing  the  crops  thrashed 
out,  and  ascertaining  the  quantity  of  corn  which  is  usually  yielded  from  a  certain 
auantity  of  straw,  for  lands  very  similar  in  outward  appearance  will  produce  a  very 
different  return  when  the  crops  are  thrashed.  A  want  of  attention  to  these  circum- 
stances is  the  cause  that  a  man  who  comes  from  a  distant  part  of  the  country,  and 
hires  a  farm  on  his  own  judgment,  seldom  succeeds  so  well  as  might  be  expected,  even 
wuh  a  superior  knowledge  of  agriculture.  He  naturally  compares  the  soil  with  some 
similar  soil  which  he  has  been  acquainted  with.  If  he  comes  from  a  district  where 
inLo  V  t*°  ^''  *°?  "^^^""^  ""h^ ''  m  request,  he  will  give  the  preference  to  very  stiff 
Ir!  fLl  >  •''''"'•^'/r"'  ^  ?^  y"^}  ^^^y'  ^^  ^^"  P^^^^^  ^^^  «««dy ;  and  the  chances 
ZXl^W  ''.^\'^^^^^  '?  ^''^  judgment,  and  finds  it  out  when  he  has  already  em- 
bailed  his  capital  in  a  losing  concern.     Next  to  the  nature  of  the  soil  is  to  be  consid- 

flfJnn  nf  .r^'^'^K  M^-^^'''?  ""L^^^  ^^^°^'  ^^'^  disposition  of  the  ficlds,  and  the  adap- 
tation  of  the  farm-buildings  to  the  most  profitable  occupation  of  the  land.     The  roads 

tX7 1 .  ''  7-'''^  !'"?  \''  '^'  neighboring  towns,  whence  manure  may  be  ot 
Jhiv^  ^^%*^°io«t  important  object,  and  if  there  is  water  carriage,  it  greatly  Inhanees 

vard  th?onnv  ^•'°'-  ?i'  '""-^^  '^  '^^  *^"^^^  '""^  '^^  ^i««^«°«^  of  these  from  the  W 
^thlhnrt^J  T'^'T^  of  having  good  pasture,  or  land  easily  laid  down  to  grass,  near 

land  Zd  fh^V  /'P'''?"^  ?'  ''*"^*^^"  «^  ^^'  farm-buifdings  with  respect  to  tS 
sfde;.d  tnS  wt''?  'tr^^''^"^  ''^^^''i  ^""  ""  circumstances  which  must  £  well  con- 
whirhVav  bl  flinlX  L^^^  probable  profits,  and  consequently  the  rent 

for  th.  T.rl  I  -u •  ^  ^^  .1^  :?-^"^''?^  situation  is  no  doubt  the  most  advantageous 
manure  Rnth^^'  *'  ^^^-^  diminishing  the  labor  in  harvest,  and  in  carrying oS 
m?ty  of'th?i«n?  "^^.be  ci^^^-js  ances  which  render  some  spot  nearer  the  eltre- 
Trec^ted  that  tT.  •  '  T^'^^"'  ^u^  '\}'  ^^^^  ^^^^^  ^^^^^^  new  buildings  are  to  be 
tered  situatinn!  T  V'^^'''''^'  ??  ^^^  farm-buildings  are  generally  in  low  and  shell 
L  the  heavtrt  thin  '*  f,  ^''^\  inconvenience  to  have  to  carry  tL  manure,  which 
^raL  sloprne  thp^i^f  h  ?  ^'^  \  ^"'™i'  -"C  *  '^''^  ^'^^  ^1^^  best  situation  is  on  a  mo- 
is^rp^rtn^^^^ 


i 

!                          j 

1      ;  1 

*            !    i 

II 


Mi 


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k; 


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^1 


76 


AKABLE  LAND. 


such  as  the  farm  requires.  The  rooms  should  be  airy  and  healthy,  facing  the  south, 
with  a  neat  garden  m  front  of  the  house.  The  farm-yard  should  be  to  the  north,  be- 
hind it  Near  the  house,  and  the  farm-yard,  there  should  be  a  small  paved  court, 
separated  from  the  j^ard  by  a  low  wall.  In  this  court,  which  should  communicate 
with  the  dairy,  utensils  may  be  placed  on  proper  benches,  to  air  and  dry  in  the  sun. 
The  architecture  of  the  buildings  may  be  left  to  the  taste  of  the  proprietor  ot  his  archi 
tect  The  simpler  it  is,  the  more  appropriate.  The  yard  or  yards  in  a  large  farm 
should  be  sheltered  on  the  north  side  by  the  barns,  which  need  not  be  so  extensive  as 
used  formerly  to  be  thought  necessary.  If  there  is  a  thrashing  machine,  a  single  floor 
to  thrash  the  seeds  upon,  and  to  employ  the  men  occasionally  in  winter,  is  quite  suf- 
ficient Every  farm  which  is  so  extensive  as  to  require  more  than  one  floor  to  thrash 
the  corn  on,  ought  always  to  have  a  thrashing  mill  attached  to  it 

A  small  yard,  distinct  from  the  other,  with  sheds  for  the  cattle  to  shelter  themselves 
under,  in  wet  and  stoi-my  weather,  is  a  great  advantage,  and  may  be  added  at  a  tri- 
fling expense  to  any  set  of  farm-buildings.  The  cart-sheds  should  be  in  the  stack-yard, 
which  properly  occupies  a  space  north  of  the  barn.  There  should  be  a  sufficient 
number  of  stands,  with  proper  pillars  and  frames  to  build  stacks  on.  Each  stack 
should  be  of  such  a  size  as  to  be  conveniently  taken  into  the  barn  to  be  thrashed  out 
The  round  form,  and  the  square  which  becomes  nearly  round  when  built  up,  are  most 
convenient  Nine  stone  or  cast-iron  pillars,  with  caps  over  them,  are  placed  on  brick 
foundations,  and  support  a  strong  frame  on  which  the  stack  is  built  In  the  centre  of 
the  stack  there  is  usually  a  pyramidical  open  frame,  to  allow  the  air  to  circulate 
through  the  stack,  and  prevent  the  heating  of  the  grain.  On  each  side  of  the  yard 
should  be  placed  the  stables,  cow-houses,  and  feeding-stalls,  with  a  pump  of  good 
water  near  the  last,  and  convenient  places  to  put  ha}',  straw,  and  turnips  m,  with  a 
machine  to  cut  them.  A  great  deal  of  time  and  labor  is  saved  by  a  proper  arrange- 
ment of  the  different  parts  of  the  farm-buildings.  An  underground  cistern  near  the 
cow-house  and  stables,  into  which  the  urine  and  washings  of  the  cow-house  may  run 
by  means  of  a  sink  or  drain,  is  a  most  useful  appendage,  which  is  too  little  thought 
of  in  England,  whereas  it  is  one  of  the  most  indispensable  parts  of  a  Flemish  farm.  It 
supplies  a  kind  of  manure,  which  can  be  applied  to  the  land  at  all  times,  which  invig- 
orates  sickly  crops,  and  may  often  produce  an  abundant  return,  where  otherwise 
there  would  be  a  complete  failure. 

In  Scotland  it  is  notorious  that  rents  are  much  higher  than  in  England,  not  only  for 
small  occupations,  but  for  extensive  farms ;  and  that  the  tenants  have  complained  less 
of  the  times  than  their  neighbors  in  the  south.  It  may  be  worth  while  to  inquire 
into  the  cause  of  this,  for  the  low  price  of  corn  must  affect  the  Scotch  farmer  equally 
with  the  English.  One  great  difference  between  the  Scotch  and  the  English  farmer  is, 
that  the  former  gets  work  done  at  a  cheaper  rate  than  the  latter.  The  Scotch  laborer 
is  fully  as  well  fed,  and  clothed,  and  lodged,  as  the  English ;  but  he  has  less  money  to 
spend  at  the  ale-house.  He  is  paid,  not  in  a  certain  sum  every  Saturday,  but  in  com- 
forts, in  the  keep  of  a  cow,  in  a  certain  number  of  rows  of  potatoes,  a  certain  quantity 
of  malt  to  make  his  beer,  a  cottage  to  live  in,  and  oatmeal  to  feed  his  family.  His 
immediate  wants  are  supplied,  and  he  is  comfortable ;  the  consequence  is,  that  he 
works  willingly.  He  has  no  remnant  of  the  last  night's  debauch  at  the  beer-shop. 
He  is  early  at  work,  and  he  does  his  work  cheerfully.  The  horses  of  a  Scotch  farmer 
are  well  fed;  they  are  always  in  good  condition.  They  work  10  and  even  12  hours 
in  a  day,  at  2  yokings.  The  ploughman  only  thinks  how  he  shall  finish  his  work  in 
proper  time,  and  unless  he  makes  the  horses  work  as  much  as  they  can  without  dis- 
tressing them,  he  knows  he  shall  not  get  through  his  work.  All  this  is  worth  25  per 
cent  on  the  whole  labor  of  the  farm,  as  Arthur  Young  has  very  judiciously  calculated, 
when  he  gives  the  expense  of  labor  on  the  farm  of  a  gentleman,  compared  with  that 
on  the  land  of  a  farmer  who  works  with  his  men.  The  moral  effect  of  an  interest  in 
the  work  to  be  done,  when  opposed  to  that  of  a  perfectly  distinct  and  often  hostile 
interest,  will  readily  account  for  so  great  a  difference. 

But  besides  this,  the  Scotch  farmer  has  generally  the  advantage  of  a  scientific  edu- 
cation, and  of  a  thorough  knowledge  of  the  principles  of  his  profession ;  and  with  the 
shrewdness  peculiar  to  his  country,  he  knows  how  to  take  advantage  of  every  favor- 
able circumstance.  He  has  also  been  taught  to  calculate,  and  will  soon  discover 
where  there  is  a  profit  or  a  loss.  This  has  made  him  turn  his  attention  to  cattle  and 
sheep  of  late  years,  more  than  to  the  production  of  corn ;  and  the  Scotch  have  found 
that  while  a  very  decent  profit  was  made  on  the  cattle,  their  land  produced  more  corn, 
although  it  sold  at  a  lower  price;  for  the  green  crops  raised  for  the  cattle,  and  the 
manure  made  by  them,  enriched  the  land  so  much,  that  the  average  produce  on  some 
light  lands  was  nearly  doubled.  All  this  kept  up  rents  to  a  much  higher  level  than 
in  England,  where  prices  were  low,  and  there  were  no  means  of  diminishing  expenses 
or  increasing  produce.  Hence  rents  in  Scotland  have  kept  up  wonderfully,  when  w« 
consider  the  great  fall  of  rents  in  England  since  the  peace. 


ARCHIL. 


77 


ABCHIL.  A  violet  red  paste  used  in  dyeing,  of  which  the  substance  called 
cudbear  in  Scotland  (from  Cuthbert,  it»  first  preparer  in  that  form),  is  a  modification. 
Two  kinds  of  archil  are  distinguished  in  commerce,  the  archil  plant  of  the  Canaries,  and 
that  of  Auvergne.  The  first  is  most  esteemed:  it  is  prepared  from  the  lichen  rocellusj 
which  grows  on  rocks  adjoining  the  sea  in  the  Canary  and  Cape  de  Verd  Islands,  in  Sar- 
dinia, Minorca,  &c.,  as  well  as  on  the  rocks  of  Sweden.  The  second  species  is  prepared 
from  the  lichen  parellus,  which  grows  on  the  basaltic  rocks  of  Auvergne. 

There  are  several  other  species  of  lichen  which  might  be  employed  in  producing  an 
analogous  dye,  were  they  prepared,  like  the  preceding,  into  the  substance  called  archil. 
Hellot  gives  the  following  method  for  discovering  if  they  possess  this  properly.  A  little 
of  the  plant  is  to  be  put  into  a  glass  vessel ;  it  is  to  be  moistened  with  ammonia  and 
lime-water  in  equal  parts ;  a  little  muriate  of  ammonia  (sal  ammoniac)  is  added ;  and 
the  small  vessel  is  corked.  If  the  plant  be  of  a  nature  to  afford  a  red  dye,  after  three  or 
four  days,  the  small  portion  of  liquid,  which  will  run  off  on  inclining  the  vessel,  now 
opened,  will  be  tinged  of  a  crimson  red,  and  the  plant  itself  will  have  assumed  this  color. 
If  the  liquor  or  the  plant  does  not  take  this  color,  nothing  need  be  hoped  for;  and  it  is 
useless  to  attempt  its  preparation  on  the  great  scale.  Lewis  says,  however,  that  he  has 
tested  in  this  way  a  great  many  mosses,  and  that  most  of  them  afforded  him  a  yellow  or 
reddish-brown  color ;  but  that  he  obtained  from  only  a  small  number  a  liquor  of  a  deep 
red,  which  communicated  to  cloth  merely  a  yeUowish-red  color. 

Prepared  archil  gives  out.  its  color  very  readily  to  water,  ammonia,  and  alcohol.  Its 
solution  in  alcohol  is  used  for  filling  spirit-of-wine  thermometers ;  and  when  these  ther- 
mometers are  well  freed  from  air,  the  liquor  loses  its  color  in  some  years,  as  Abbe 
Nollet  observed.  The  contact  of  air  restores  the  color,  which  is  destroyed  anew,  in 
vacuo,  in  process  of  time.  The  watery  infusion  loses  its  color,  by  the  privation  of  air, 
in  a  few  days ;  a  singular  phenomenon,  which  merits  new  researches. 

The  infusion  of  archil  is  of  a  crimson  bordering  on  violet.  As  it  contains  ammonia, 
which  has  akeady  modified  its  natural  color,  the  fixed  alkalies  can  produce  little  change 
on  it,  only  deepening  the  color  a  little,  and  making  it  more  violet.  Alum  forms  inlit 
a  precipitate  of  a  brown  red;  and  the  supernatant  liquid  retains  a  yellowish-red  color. 
The  solution  of  tin  affords  a  reddish  precipitate,  which  falls  down  slowly ;  the  super- 
natant liquid  retains  a  feeble  red  color.  The  other  metallic  salts  produce  precipitates 
which  offer  nothing  remarkable. 

The  watery  solution  of  archil,  applied  to  cold  marble,  penetrates  it,  communicating  a 
beautiful  violet  color,  or  a  blue  bordering  on  purple,  which  resists  the  air  much  longer 
than  the  archil  colors  applied  to  other  substances.  Dufay  says,  that  he  has  seen  marble 
tinned  with  this  color  preserve  it  without  alteration  at  the  end  of  two  years. 

To  dye  with  archil,  the  quantity  of  this  substance  deemed  necessary,  according  to  the 
quantity  of  wool  or  stuff  to  be  dyed,  and  according  to  the  shade  to  which  they  are  to  he 
brought,  is  to  be  diffused  in  a  bath  of  water  as  soon  as  it  begins  to  grow  warm.  The  bath 
IS  then  healed  till  it  be  ready  to  boU,  and  the  wool  or  stuff  is  passed  through  it  without 
Tl  «t^e':PrfParat.on,  except  keeping  that  longest  in,  which  is  to  have  the  deepest  shade. 
A  hne  gridehn,  bordering  upon  violet,  is  thereby  obtained ;  but  this  color  has  no  perma- 
afvo  1*  .  ?''?u^'*'^u  '^  ""^^^y  employed  with  any  other  view  than  to  modifv,  heighten,  and 
give  lustre  to  the  other  colors  Hellot  says,  that  having  employed  archifon  wool  h^^iled 
with  tartar  and  alum,  the  color  resisted  the  air  no  more  than  what  had  received  no 

cZ-Tv  wf  •  ^\''^v^'f  ^  ^'°"'  ?^'.^  ^'^^'^  (''*^^^^"«  '^''^^^^)  a  «^"ch  more  durable 
^nW  **y  P  =  '''  ^^^  ^^^^  "'^'"^  '°^''*'""  °^  *^"-  '^^e  a'-chil  thereby  loses  its  natural 
nf  li.,t"  ^f""."^^  one  approaching  more  or  less  to  scariet,  according  to  the  quantity 
a«  thnt  7  '^^'iY'^T^^^y^:  This  process  must  be  executed  in  nearly  Ihe  same  mannS 
as  that  of  scarlet,  except  that  the  dyeing  may  be  performed  in  a  single  bath. 

I„Jt^.    l"^    T-^"'^^^]'^^'"^^'''^^^^  for  varying  the  different  shades  and  giving  them 

deetr  tSne'L  /o7the  ^T  ^^''''''  '"^''^'-  °^^"^"^'  '^^^  ^^^^^^^^^  A^^^^^-  To  obtain^ 
n>;t^MTif'-*     S[        ■  ^eep  soupes  au  mn,  sometunes  a  little  alkali  or  milk  of  lime  is 

AJum  Lnnnt  bp      T  ^Z  J^'"^  J^''"^'  ^^  ^^*^^°^^  ««  ^^^"^i^^  ^Y  ^t^er  processes 

it  S'mmunt^t^^  V'  T^"™,^^^  ^«  the  ^chU  of  Auvergne,  from  the  greater  bloom  which 
has  SShp  tl  !?  ^^^  ^''^r'^  ^"^^  ^'^"^  ^^^  ^^'^^'  ^"^ntity  of  coloring  matter.  It 
Jrith^um  '  whi.h^'?''l^^'  of  bearing  ebullition.  The  latter,  moreover,  dols  not  answer 
d?eL.n  an  !r'  ^  f^^'"^'  ^^^  '^^°' '  ^^^  *^«  ^^'^  "^^^^  ^^^  ^^^  inconvenience  of 
Sr^„^,onnnfT^"  manner  unless  attention  be  given  to  pass  the  cloth  through  hot 
water  as  soon  as  it  comes  out  of  the  dye.  =  *-  s     "*/v 

WL^^^.rniT  \*1?  ^^J^^  ^>'""^  '^»  "n^e^s  for  lilachs;  butsflk  is  frequently 
ff  in  n^r  "i  ^^^  rr"'S'  ^^^^'  ^'^^'^  ^>'^i^S  '''  ^^  ^^'^'  ^^ths  or  after  it  hTS 
dyed,  m  order  to  modifv  different  colors,  or  to  give  them   lustre.    Examples  of  Tms 


i  il! 


Hi 


il 


It 


I 


78 


ARCHIL. 


among  which  he  found  several  which  might 
He  recommends  that  the  coloring  matter  should  be  extracted  in 


will  be  given  i^;^  treating  of  the  compound  colors.  It  is  sufficient  here  to  point  out  how 
while  silks  are  passed  through  the  archil  bath.  The  same  process  is  performed  with  a 
bath  more  or  less  charged  with  this  color,  for  silks  already  dyed. 

Archil,  in  a  quantity  proportioned  to  the  color  desired,  is  to  be  boiled  in  a  copper.  The 
clear  liquid  is  to  be  run  off  quite  hot  from  the  archil  bath,  leaving  the  sediment  at  the 
bottom,  into  a  tub  of  proper  size,  in  which  the  silks,  newly  scoured  with  soap,  are  to  be 
turned  raund  on  the  skein-sticks  with  much  exactness,  till  they  have  attained  the  wished- 
for  shade.     After  this  they  must  receive  one  beetling  at  the  river. 

Archil  is  in  general  a  very  useful  ingredient  in  dyeing ;  but  as  it  is  rich  in  color,  and 
communicaies  an  alluring  bloom,  dyers  are  often  tempted  to  abuse  it,  and  to  exceed  the 
proportions  that  can  add  to  the  beauty  without  at  the  same  time  injuring  in  a  dangerous 
manner  the  permanence  of  the  colors.  Nevertheless,  the  color  obtained  when  solution 
of  tin  is  employed,  is  less  fugitive  than  without  this  addition  :  it  is  red,  approaching  to 
scarlet.  Tin  appears  to  be  the  only  ingredient  which  can  increase  its  durability.  The 
solution  of  tin  may  be  employed,  not  only  in  the  dyeing  bath,  but  for  the  preparation  of 
the  silk.  In  this  case,  by  mixing  the  archil  with  other  coloring  substances,  dyes  may  be 
obtained  which  have  lustre  with  sufficient  durability. 

We  have  spoken  of  the  color  of  the  archil  as  if  it  were  natural  to  it ;  but  it  is,  really, 
due  to  an  alkaline  combination.  The  acids  make  it  pass  to  red,  either  by  saturating  the 
alkali,  or  by  substituting  themselves  for  the  alkali. 

The  lichen  w^hich  produces  archil  is  subjected  to  another  preparation,  to  make  turn- 
sole (litmus).  This  article  is  made  in  Holland.  The  lichen  comes  from  the  Canary 
Islands,  and  also  from  Sweden.  It  is  reduced  to  a  fine  powder  by  means  of  a  mill, 
and  a  certain  proportion  of  potash  is  mixed  with  it.  The  mixture  is  watered  with 
urine,  and  allowed  to  suffer  a  species  of  fermentation.  When  this  has  arrived  at  a 
certain  degree,  carbonate  of  lime  in  powder  is  added,  to  give  consistence  and  weight  to 
the  paste,  which  is  afterwards  reduced  into  small  parallelopipeds  that  are  carefully 
dried. 

The  latest  researches  on  the  lichens,  as  objects  of  manufacture,  are  those  of  Westring 
of  Stockholm.     He  examined  150  species, 
be  rendered  useful. 

the  places  where  they  grow,  which  would  save  a  vast  expense  in  curing,  package,  car 
riage,  and  waste.  He  styles  the  coloring  substance  itself  cutbear,  persio,  or  turnsole ; 
and  distributes  the  lichens  as  follows  : — 1st.  Those  which,  left  to  themselves,  exposed  to 
moderate  heat  and  moisture,  may  be  fixed  without  a  mordant  upon  wool  or  silk ;  such 
are  the  L.  ciriereus,  amaianta,  ventosus,  corallinus,  wesirivgiiy  saxatilis,  conspassus,  bar' 
batus,  plicatus,  vnlpinus,  Sec. 

2.  Those  which  develop  a  coloring  matter,  fixable  likewise  without  mordant,  but  which 
require  boiling  and  a  complicated  preparation ;  such  are  the  lichens  subcameus,  dillenii, 
farinaceuSf  jubaius,  fur/uraceus,  pulmonareusy  comigatus,  cocciferus,  digilatus,  ancia- 
lis,  aduncus,  &.C.  Saltpetre  or  sea-salt  is  requisite  to  improve  the  lustre  and  fastness 
of  the  dye  given  by  this  group  to  silk. 

3.  Those  which  require  a  peculiar  process  to  develop  their  color ;  such  as  those 
which  become  purple  through  the  agency  of  stale  urine  or  ammonia.  Westring  em- 
ployed the  following  mode  of  testing : — He  put  three  or  four  drachms  of  the  dried 
and  powdered  lichen  into  a  flask ;  moistened  it  with  three  or  four  measures  of  cold 
spring  water ;  put  the  stuff  to  be  dyed  into  the  mixture,  and  left  the  flask  in  a  cool 
place.  Sometimes  he  added  a  little  salt,  saltpetre,  quicklime,  or  sulphate  of  copper.  If 
no  color  appeared,  he  then  moistened  the  lichen  with  water  containing  one  twentieth 
of  sal  ammoniac,  and  one  tenth  of  quicklime,  and  set  the  mixture  aside  in  a  cool  place 
from  eight  to  fourteen  days.  There  appeared  in  most  cases  a  reddish  or  violet  colored 
tint.  Thus  the  lichen  cinereus  dyed  silk  a  deep  carmelite,  and  wool  a  light  carmelite ; 
the  l.physodes  gave  a  yellowish-gray;  the  pustulatus,  a  rose  red;  sanguinarius,  gray; 
tartareusj  found  on  the  rocks  of  Norway,  Scotland,  and  England,  dyes  a  crimson-red. 
In  Jutland,  cutbear  is  made  froin  it,  by  grinding  the  dry  lichen,  sifting  it,  then  setting 
it  to  ferment  in  a  close  vessel  with  ammonia.  The  lichen  must  be  of  the  third  year's 
growth  to  yield  an  abundant  dye ;  and  that  which  grows  near  the  sea  is  the  best.  It 
loses  half  its  weight  by  drying.  A  single  person  may  gather  from  twenty  to  thirty 
pounds  a  day  in  situations  where  it  abounds.  No  less  than  2,239,685  pounds  were 
manufactured  at  Chrisliansand,  Flekkefiort,  and  Fakrsund,  in  Norway,  in  the  course  of 
the  six  years  prior  to  1812.  Since  more  solid  dyes  of  the  same  shade  have  been 
invented,  the  archil  has  gone  much  into  disuse.  Federigo,  of  Florence,  who  revived 
its  use  at  the  beg^Inning  of  the  fourteenth  century,  maJe  such  an  immense  fortune  by  its 
preparation,  that  his  family  became  one  of  the  grandees  of  that  city,  under  the  name  of 
Oricellarii,  or  Rucellarii.  For  more  than  a  century  Italy  possessed  the  exclusive  art  of 
making  archil,  obtaining  the  lichens  from  the  islands  of  the  Mediterranean.  According 
to  an  official  report  of  1831,  Teneriffe  furnished  annually  500  quintals  (cwts.)  of  lichen  j 


ARROW  ROOT. 


79 


the  Canary  Isles,  400;  Fuerta  Santura,  300 ;  Lancerot.  300:  Gomera,  300;  Isle  of 
Ferro.  800.  This  business  belonged  to  the  crown,  and  brought  in  a  revenue  of  1500 
piastres.  The  farmers  paid  from  15  to  20  reals  for  the  right  to  gether  each  quintal 
At  that  time  the  quintal  fetelied  in  the  London  market  4/.  sterling. 

Archil  is  perhaps  too  much  used  in  some  cloth  factories  of  England,  to  the  discredit 
of  our  dyes  It  is  said,  that  by  its  aid  one  third  of  the  indigo  may  be  saved  in  the 
blue  vat  •  but  the  color  is  so  much  the  more  perishable.  The  iine  soft  tint  induced 
upon  much  of  the  black  cloth  by  means  of  archil  is  also  deceptive.  One  hail-pound 
of  cudbear  will  dye  one  pound  of  woolen  cloth.  A  crimson  red  is  obtained  by  adding 
to  the  decoction  of  archil  a  little  salt  of  tin  (muriate),  and  passing  the  cloth  through 
the  bath,  after  it  has  beeu  prepared  by  a  mordant  of  tin  and  tartar.  It  must  be  af- 
terwards passed  through  hot  water.  ,      ^  .  ,.        u   ^  •  ^  • 

The  lichens  have  been  of  late  years  subjects  of  a  multitude  of  interesting  but  intri- 
cate chemical  researches,  and  a  number  of  new  compounds  have  been  produced,  as 
lecanorin,  from  lecanora,  and  variolaria,  with  which  colorless  substance  a  purple  red 
is  formed  by  the  action  of  ammonia  and  the  air;  also  erythrine  and  erythryline  from 
several  sorts  of  lichens,  especially  parmeliar  ocella  and  tartarean,  which  afford,  when 
digested  with  ammonia,  a  bright  red  dye,  but  if  treated  with  alcohol  only^  a  white 
granular  precipitate,  when  the  solution  is  slowly  evaporated ;  orcine  and  orceine  are 
somewhat  analogous  products,  also  crystallizable,  which  may  be  obtained  from  the 
variolaria  dealbafa,  by  decomposition  of  the  lecanorine.  It  has  a  sweet  nauseous 
taste,  and  melts  into  a  colorless  fluid,  which  may  be  distilled.  It  is  soluble  both  in 
water  and  alcohoL     Orceine  by  means  of  ammonia  and  air  forms  archil. 

Dyeing  with  archil  with  the  aid  of  oil  has  been  patented  by  Mr.  Ligbtfoot,  on  the 
same  principle  as  has  been  so  long  used  in  the  Turkey  red  cotton  dye.  He  has  also 
recourse  to  metallic  and  earthy  bases,  with  what  success  I  have  not  heard.  Alumina- 
ted  potash  is  likewise  mentioned  along  with  a  great  variety  of  other  chemicals. 

ARDENT  SPIRIT.    Alcohol  of  moderate  strength. 

AREOMETER  OF  BAUME'.    This  scale  is  much  used  by  the  French  authors. 

Specific  Gravity  Numbers  corresponding  with  Baume's  Areometric  Degrees. 


Liquids  denser  than  Water.                              | 

Less  dense  than  Water. 

De- 

Speuifie 

De- 

Specific 

De- 

Specific 

De- 

Specific 

De- 

Specific 

grees. 

gravity. 

grees. 

gravity. 

grees. 

gravity. 

grees. 

gravity. 

grees. 

gravity. 

0 

10000 

26 

1-2003 

52 

1-5200 

10 

1-0000 

36 

0-8488 

1 

10066 

27 

12160 

53 

1-5353 

11 

09932 

37 

0-8139 

2 

1-0133 

28 

1-2258 

54 

1-5510 

12 

0-9865 

38 

08391 

3 

10201 

29 

1-2358 

55 

1-5671 

13 

09799 

39 

0-8343 

4 

10270 

30 

1  2459 

56 

158.33 

14 

0-9733 

40 

0.8295 

5 

10340 

31 

1-2562 

57 

1-6000 

15 

09669 

41 
42 

0  8S49 

6 

10411 

32 

1-2667 

58 

1-6170 

16 

0-9605 

0-8202 

7 

10483 

33 

1-2773 

59 

1-6344 

17 

0-9542 

43 

0-8156 

8 

10556 

34 

1-2881 

60 

1-6522 

18 

0-9480 

44 

0  8111 

9 

10630 

35 

1-2992 

61 

1-6705 

19 

0-9420 

45 

0-8066 

10 

10704 

36 

1-3103 

62 

1-68S9 

20 

0-9359 

46 

0-8022 

11 

1-0780 

37 

1-3217 

63 

1-7079 

21 

09300 

47 

0-7978 

12 

1-0857 

38 

1-3333 

64 

1-7273 

22 

0-9241 

48 

0-7935 

13 

10935 

39 

1-3451 

65 

17471 

23 

0-9183 

49 

0-7892 

14 

1  1014 

40 

1-3571 

66 

1-7674 

24 

0-9125 

50 

0-7849 

15 

16 

1-1095 

41 

13694 

67 

1-7882 

25 

0-9068 

51 
52 

0-7807 

1-1176 

42 

1-3818 

68 

1-8095 

26 

09012 

0-7766 

17 

1  1259 

43 

1-3945 

69 

1-8313 

27 

0-8957 

53 

0-7725 

18 

1  1343 

44 

1-4074 

70 

1-8537    • 

28 

0-8902 

54 

0-76»l 

19 

11428 

45 

1-4206 

71 

1-8765 

29 

0-8848 

55 

0-7643 

20 

11515 

46 

1-4339 

72 

1-9000 

30 

0-8795 

56 

07604 

21 

11603 

47 

1-4476 

73 

1-9241 

31 

0-R742 

57 

0-7656 

22 

11692 

48 

1-4615 

74 

1-9487 

32 

0-8690 

58 

0-7526 

23 

11783 

49 

1-4758 

75 

1-9740 

33 

08639 

59 

0-7487 

24 

1  1875 

50 

1-4902 

76 

20000 

34 

0-8588 

60 

0-7449 

1    « 

I  1968 

51 

1-4951 

35 

0-8538 

61 

0-7411 

ARGILLACEOUS  EARTH.  The  earth  of  clay,  called  in  chemistry  alumina,  because 
it  is  obtained  in  greatest  purity  from  alum. 

ARGOL.     Crude  tartar  ;  which  see. 

ARMS.     Weapons  of  war.     See  Fire-Arms  for  an  account  of  this  manufacture. 

ARRACK.  A  kind  of  intoxicating  beverage  made  in  India,  by  distilling  the  ferment- 
ed juice  of  the  cocoa-nut,  the  palmyra  tree,  and  rice  in  the  husk. 

ARROW  ROOT.  The  root  of  the  maranta  arundinacea,  a  plant  which  grows  in  the 
"West  Indies,  furnishes,  by  pounding  in  mortars  and  elutriation  through  sieves,  a  peculiar 
species  of  starch,  commonly,  but  improperly  called  arrow  root.    It  is  reckoned  more 


'  fe 


i 


80 


ARROW  ROOT. 


noiirislimg  than  the  starch  of  wh<.at  or  potatoets  and  is  generallj-  also  freer  from  pe 
culiar  taste  or  flavor.  The  fresh  root  consists,  according  to  Benzon,  of  007  of  vola 
tiJe  oil ;  26  of  starch  (23  of  which  are  obtained  in  the  form  of  powder  while  the 
other  3  must  be  extracted  from  the  parenchyma  in  a  paute  by  boiling  water)-  1-58 
pi  vegetable  albumen;  0-6  of  a  gummy  extract;  0'25  of  chloride  of  calcium'  6  of 
insoluble  fibrme  ;  and  65*6  of  water. 

^  This  plant  has  been  lately  cultivated  with  great  succoss,  and  its  root  manufactured 
in  a  superior  manner,  upon  the  Hopewell  estate,  in  the  island  of  St  Vincent.  It 
grows  there  to  the  height  of  about  3  feet,  and  it  sends  down  its  tap  roots  from  12  to 
18  inches  into  the  ground.     Its  maturity  is  known  by  the  flagging  and  falling  down 

1^     rif  ^''^'' f ''.^':^°^^^'*^^  *^^^»  place  when  the  plant  is  from  10  to  12  months 
Old.     Ihe  roots  being  dug  up  with  the  hoe  are  transported  to  the  washing-house, 
where  they  are  thoroughly  freed  from  all  adhering  earth,  and  next  taken  individually 
nto  the  hand,  and  deprived  by  a  knife  of  every  portion  of  their  skins,  while  every 
unsound  part  is  cut  away.     This  process  must  be  performed  with  great  nicety,  for 
the  cuticle  contains  a  resinous  matter,  which  imparts  color  and  a  disagreeable  flivor 
to  the  fecula,  which  no  subsequent  treatment  can  remove.     The  skinned  roots  are 
thrown  into  a  large  cistern,  with  a  perforated  bottom,  and  there  exposed  to  the 
aetion  of  a  copious  cascade  of  pure  water,  till  this  runs  off  quite  unaltered.     The 
cleansed  roots  are  next  i)ut  into  the  hopper  of  the  mill,  and  are  subjected  to  the  pow- 
erful pressure  of  two  pairs  of  polished  rollers  of  hard  brass;  the  lower  pair  of  rollers 
l>eing  set  much  closer  together  than  the  upper.    (See  the  accompanying  figure.)    The 
starchy  matter  is  thus  ground  into  a  pulp  which  falls  into  the  receiver  placed  be- 
neath, and  IS  thence  transferred  to  large  fixed  copper  cylinders,  tinned  inside,  and 
pertorated  at  the  bottom  with  numerous  minute  orifices,  like  a  kitchen  drainer. 
Within  these  cylinders,  wooden  paddles  are  made  to  revolve  with  great  velocity  by 
the  power  of  a  water-wheel,  at  the  same  time  that  a  stream  of  pure  water  is  admit- 
ted trom  above     The  paddle  arms  beat  out  the  fecula  from  the  fibres  and  parenchyma 
ot  the  pulp,  and  discharge  it  in  the  form  of  a  milk  through  the  perforated  bottom  of 
the  cylinder.     This  starchy  water  runs  along  pipes,  and  then  through  strainers  of 
fine  muslin  into  large  reservoirs,  where,  after  the  fecula  has  subsided,  the  superna- 
tant water  is  drawn  off,  and  fresh  water  being  let  on,  the  whole  is  agitated  and  left 
again  to  repose.     This  process  of  ablution  is  repeated  till  the  water  no  longer  ac- 
quires any  thing  from  the  fecula.     Finally,  aU  the  deposits  of  fecula  of  the  day's 
work  are  collected  into  one  cistern,  and,  being  covered  and  agitated  with  a  fresh 
charge  of  water,  are  allowed  to  settle  till  next  morning.     The  water  being  now  let 
ott  the  deposit  is  skimmed  with  palette  knives  of  German  silver,  to  remove  any  of 
the  superficial  parts,  m  the  slightest  degree  colored;  and  only  the  lower,  purer,  and 
denser  portion  is  prepared  by  drying  for  the  market.     The  drying-house  on  the 
Hopewell  estate  is  constructed  like  the  hothouse  of  an  English  garden     But  instead 
P'^nts,  It  contains  about  4  dozen  of  drying  pans  made  of  copper,  Ti  feet  by  4i, 
and  tinned  mside     Each  pan  is  supported  on  a  carriage,  having  iron  axles.  wi^I 
lignum  vit«  wheels,  like  those  of  a  railway  carriage,  and  they  run  on  rails.     Imme- 
diately alter  sunrise,  these  carriages  with  their  pans,  covered  with  white  gauze,  to 
exclude  dust  and  insects,  are  run  out  into  the  open  air,  but  if  rain  be  apprehended, 
they  are  run  back  under  the  glazed  roof     In  about  4  days  the  fecula  is  thorouehly 
dry  and  ready  to  be  packed,  with  German  silver  shovels,  into  tins  or  American  flour 
barrels,  lined  with  paper  attached  with  arrow  root  paste.     The  packages  are  never 
sent  to  this  country  m  the  hold  of  the  ship,  as  their  contents  are  easily  tainted 
by  noisome  effluvia,  of  sugar,  &c.     By  such  a  skilful  series  of  operations,  and  by 
such  precautions,  the  arrow  root   thus  manufactured    may  vie  with  any  similar 
preparation  in  the  Bermudas  or  any  other  part  of  the  world.     I  have  found  it,  on 
of  fooT         ^*'^^''  ^^  ^^  ^"^"^'  P*'^^^^"^»  ^"^  agreeable,  and  a  most  wholesome  article 

Fig.  26.  Plan  of  arrow  root  grinding-mill,  and  of  2  sets  of  copper  cylinder  wash- 
ing-machines, with  the  connecting  machinery  for  driving  them ;  the  washing  agitator 
being  driven  from  the  connecting  shaft  with  leathern  belts.  Fig.  27.  End  elvevation 
of  arrow  root  mill,  with  wheels  and  pinions,  disengaging  lever,  Ac.  Fig.  28.  End 
elevation  of  copper  washing-cylinders,  with  pres8-framin|,  «kc.  The  washing-cylin- 
dere  are  6i  feet  long  and  3i  in  diameter.  The  mill-rollers  are  3  feet  long  and  1  foot 
m  diameter.  ° 


ARROW  ROOT. 


81 


i 


The  uses  of  arrow  root  are  too  well  known  and  acknow- 
ledged to  require  recounting  here.  It  is  the  most  elegant 
and  the  richest  of  all  the  feculas,  and  being  now  mann- 
I  factured,  with  the  advantage  of  excellent  machinery,  and 
J  abundance  of  pure  water,  in  the  fertile  island  of  St.  Vincent, 
it  may  he  brought  into  our  market  at  a  much  more  moderate 
price  than  it  has  heretofore  been  supplied  from  less  favored 
localities.  The  Bermuda  arrow  root  is  treated  necessarily 
with  rain  water  collected  in  tanks,  and  therefore  is  occa- 
sionally soiled  with  insects,  from  which  the  St.  Vincent  arti- 
cle is  entirely  free. 


(" 


I 


li 


■w 


82 


ARSEN^IC. 


The  presence  of  potato  starch  in  arrow  root  may  be  discovered  by  the  microsc*  pe. 
Arrow  root  consists  of  regular  ovoid  particles  of  nearly  equal  size,  whereas  po^to 
Btarch  consists  of  particles  of  an  irregular  ovoM  or  truncated  form,  exceedingly  irre- 
gular in  their  dimensions,  some  being  so  lai^e  as  ^^^  of  an  inch,  and  others  only  -q\j^. 
But  the  niost  convenient  test  is  dilute  nitric  acid  of  1 -10  (about  the  strength  of  single 
aquafortis),  which,  when  triturated  in  a  mortar  with  the  starch,  forms  immediately  a 
transparent  very  viscid  paste  or  jelly.  Flour  starch  6xliibits  alike  appearance.  Arrow 
root,  however,  forms  an.opaque  paste,  and  takes  a  much  longer  time  to  become  viscii 

Arrow  root  may  be  distinguished  from  potato  starch,  not  only  by  the  different  size 
of  its  particles,  but  by  the  difference  of  structure.  Their  surfaces  in  the  arrow  root 
•re  smooth,  and  free  from  the  streaks  and  furrows  seen  in  the  potato  particles  by  a 
good  microscope.  The  arrow  root,  moreover,  is  destitute  of  that  fetid  unwholesome 
oil  extractable  by  alcohol  from  potato  starch. 

Liebig  places  the  powers  of  arrow  root,  as  a  nutriment  to  man,  in  a  very  remarka- 
ble point  of  view,  when  he  states  that  15  pounds  of  flesh  contain  no  more  carbon  for 
supplying  animal  heat  bv  its  combustion  into  carbonic  acid  in  the  system  than  4 
pounds  of  starch  ;  and  that  if  a  savage,  with  one  animal  and  an  equal  weight  of 
•tarch,  could  maintain  life  and  health  for  a  certain  number  of  days,  he  would  be 
eompelled,  if  confined  to  flesh  alone,  in  order  to  procure  the  carbon  necessary  for 
respiration  during  the  same  time,  to  consume  five  such  animals. 

Quantities  imported  - 
Quantities  exported    - 
Retained  for  consumption 
Net  revenue 

ARSENIC.  This  metal  occurs  native,  in  the  state  of  oxide,  and  also  combined  with 
aalphur  under  the  improper  name  of  yellow  and  red  arsenic,  or  orpiment  and  realgar. 
Arsenic  is  associated  with  a  great  many  metallic  ores  ;  but  it  is  chiefly  extracted  fi-om 
those  of  cobalt,  by  roasting,  in  which  case  the  white  oxide  of  arsenic,  or,  more  cor- 
rectly, the  arsenious  acid  is  obtained.  This  acid  is  introduced  occasionally  in  small 
quantities  into  the  materials  of  flint  glass,  either  before  their  fusion,  or  in  the  melting 
pot  It  serves  to  peroxidize  the  iron  oxide  in  the  sand,  and  thereby  to  purify  the  body 
of  the  glass ;  but  an  excess  of  it  makes  the  glass  milky. 

ScheelcH  green  is  a  combination  of  this  arsenious  acid  with  oxide  of  copper,  or  an 
arsenit^  of  copper,  and  is  described  under  this  metal. 

Arseniate  of  potash  is  prepared,  in  the  small  wa}^,  by  exposing  to  a  moderate  heai^' 
in  a  crucible  a  mixture  of  equal  parts  of  white  ai-senic  and  nitre  in  powder.  After 
fusion  the  crucible  is  to  be  cooled ;  the  contents  being  dissolved  in  hot  water,  and 
the  solution  filtered,  will  afford  regular  crystals  on  cooling.  According  to  M.  Berze- 
lius,  they  are  composed  of  arsenic  acid,  63-87  ;  potash,  26*16;  and  water,  997.  It  ia 
an  acidulous  salt,  and  is  hence  usually  called  the  binarseniate,  to  denote  that  its  com- 
position is  2  atoms  of  arsenic  acid,  and  1  of  potash.  Tliis  article  is  prepared  upon 
the  great  scale,  in  Saxony,  by  melting  nitre  and  arsenious  acid  together  in  a  cylinder 
of  cast-iron.  A  neutral  arseniate  also  is  readily  formed,  by  saturating  the  excess  of 
acid  in  the  above  salt  with  potash;  it  does  not  crystallize.  The  acid  arseniate  is  oc- 
casionally used  in  calico  printing,  for  preventing  certain  points  of  the  cotton  cloth 
ft^m  taking  on  the  mordant ;  with  which  view  it  is  mixed  up  with  gum  water  and 
pipe  clay  into  a  paste,  which  is  applied  to  such  places  with  a  block. 


1841. 

1842. 

1843. 

1844. 

cwt  — 

7953 

9236 

10274 

cwt  

334 

264 

200 

cwt.  

7561 

8499 

10018 

19  1012 

737 

623 

769 

ARSENIC. 


88 


The  extraction  of  arsenic  from  the  cobalt  ores,  is  performed  at  Altenberg  and  Reichen- 
stein,  in  Silesia,  with  an  apparatus,  excellently  contrived  to  protect  the  health  of  the 
smellers  from  the  vapors  of  this  most  noxious  metaUic  sublunate.  . 

Fiss.  29  to  32  represent  the  arsenical  furnaces  at  Altenberg.  Fig.  29  is  a  vertical 
section  of  the  poison  tower;  fig.  30,  a  longitudinal  section  of  the  subliming  furnace  a, 
with  the  adjoining  vault  b,  and  the  poison  tower  in  part  at  w;  fig.  31,  the  transverse 
section  of  the  furnace  a,  of  yig.  30 ;  fig.  32,  ground  plan  of  the  furnace  a,  wher^-  the 
lefX  half  shows  the  part  above,  and  the  right  the  part  below  the  muffle  or  oblong 
retort;  b'  is  the  upper  view,  b"  the  ground  plan  of  the  vault  b,  of^ig.  30;  m,  n,  the 
base  of  the  poison  tower.  In  the  several  figures  the  same  letters  denote  the  same  objects; 


a  is  the  muffle ;  6  is  its  mouth  for  turning  over  the  arsenical  schlich,  or  ground  ore ; 
cc  c,  fire  draughts  or  flues ;  rf,  an  aperture  for  charging  the  muffle  with  fresh  schlich ; 
c,  the  smoke  chimney  ;  /,  two  channels  or  flues  for  the  ascent  of  the  arsenious  fumes, 
which  proceed  to  otlver  two  flues  g,  and  then  terminate  both  in  ft,  which  conducts  the 
fumes  into  the  vault  b.  They  issue  by  the  door  t,  into  the  conduit  fc,  thence  by  /  into  the 
spaces  m,  n,  o,  p,  q,  r,  of  the  tower.  The  incondensable  gases  escape  by  the  chimney,  *. 
The  cover  ^  is  removed  afler  completion  of  the  process,  in  order  to  push  down  the  pre- 
cipitate into  the  lower  compartments. 

The  arsenious  schlichs,  to  the  amount  of  9  or  10  cwt.  for  one  operation  (1  roaai-post, 
or  roasting  round),  are  spread  2  or  3  inches  thick  upon  the  bottom  of  the  muffle,  Heated 
with  a  brisk  fire  to  redness,  then  with  a  gentler  heat,  in  order  to  oxydize  completely, 
before  subliming,  the  arsenical  ore.  With  this  view  the  air  must  have  free  entrance,  and 
the  front  a|)erture  of  the  muffle  must  be  left  quite  open.  After  11  or  12  hours,  the  cal- 
cined materials  are  raked  out  by  the  mouth  of  the  muffle,  and  fresh  ones  are  introdcced 
hy  the  openings  indicated  above,  which  are  closed  during  the  sublimation. 

The  arsenious  acid  found  in  these  passages  is  not  marketable  till  it  be  re-sublimed  in 
large  iron  pots,  surmounted  with  a  series  of  sheet  iron  drums  or  cast-iron  cylinders,  upon 
the  sides  of  which  the  arsenic  is  condensed  in  its  compact  glassy  form.  The  top  cylinder 
is  furnished  with  a  pipe,  which  terminates  in  a  condensing  chamber. 

Figs.  33,  34,  represent  the  arsenic  refining  furnaces  at  Reichenstein.     Fig.  33  .shows 


I' 


(' 


84 


ARSENIC- 


at  A,  a  vertical  section  of  the  (\imace, 
the  kettle,  and  the  surmounting  drums 
or  cylinders ;  over  b  it  is  seen  in  eleva- 
tion ;  fig.  34  is  a  ground  plan  of  the 
four  fireplaces,  a  is  the  grate ;  6,  the 
ash-pit;  c,  the  openings  for  firing;  d, 
the  fire-place ;  e,  iron  pots  or  kettles 
which  are  charged  with  the  arsenious 
powder;  /,  the  fire-flues  proceeding  to 
the  common  chimney  g;  A,  iron  cy- 
linders; »,  caps;  ky  pipes  leading  to 
the  poison  vent  I ;  m,  openings  in  the 
pipes  for  introducing  the  probing 
wires. 

The  conduct  of  the  process  is  as 
follows:— The  pot  is  filled  nearly  to 
its  brim  with  3|  cwt.  of  the  arsenic 
meal,  the  cylinders  are  fitted  on  by 
means  of  their  handles,  and  luted  to- 
gether with  a  mixture  of  loam,  blood, 
and  hair ;  then  is  applied  first  a  gentle, 
and  after  half  an  hour,  a  strong  fire, 
whereby  the  arsenic  is  raised  partly 
in  the  form  of  a  white  dust,  and  partly 
in  crystals ;  which,  by  the  contin  jance 
of  the  heat,  fuse  together  into  a  homo- 
geneous mass.  If  the  fire  be  too  fee- 
ble, only  a  sublimate  is  obtained ;  but, 
if  too  violent,  much  of  the  arsenic  is 
volatilized  into  the  pipes.  The  work- 
men judge  by  the  heat  of  the  cylin- 
ders whether  the  operation  be  going 
on  well  or  not.  After  12  hours  the 
furnace  is  allowed  to  cool,  provided 
the  probe  wires  show  that  the  subli- 
mation is  over.  The  cylinders  are 
then  lifted  oflT,  and  the  arsenious  glass 
is  detached  from  their  inner  surface. 
According  to  the  quality  of  the  poison - 
flour,  it  yields  from  f  to  |  of  its  weight 

Of  the  glass  or  enamel.     Should  any  dark  particles  of  metallic  arsenic  be  intermixed  with 

the  glass,  a  fresh  sublimation  must  be  had  recourse  to. 

The  following  is  the  product  in  cwts.  of  arsenious  acid,  at  Altenberg  and  Reichenstein, 
in  Silesia,  in  the  years 


White  arsenic  in  a  glassy 

1835. 

1826. 

1827. 

1828. 

1829, 

1830. 

1831. 

1632. 

state-        ... 

2632 

1703 

2686 

1900 

2070 

2961 

3337 

2730 

Sublimed  arsenic  in  pow- 

• 

der- 

m 

27 

33 

31 

30 

44 

69 

38 

Yellow  arsenical  glass  - 

112 

11 

56 

86 

313 

60 

219 

Red  arsenical  glass 

3 

- 

- 

• 

28 

Arsenical  Foisov  {detection  o/).— It  is  well  known  that  fluids  mixed  with  glutinotis 
matter  are  very  liable  to  froth  up  when  hydrogen  is  disengaged  in  them  from  the  mutu- 
al action  of  zinc  and  a  dilute  acid ;  and  that  the  froth  obstructs  the  due  performance  of 
the  experiment  of  Marsh.  It  is  equally  known,  that  much  of  the  arsenic  contained  in 
the  poisonous  liquid  so  tested  escapes  condensation  and  eludes  measurement  A  com- 
naittee,  appointed  by  the  Prussian  government,  have  contrived  an  ingenious  modifica- 
tion of  Marsh's  apparatus,  which  I  have  simplified  into  the  annexed  form:— a  is  a 
narrow  glass  cyhnder,  open  at  top,  about  10  inches  high,  and  U  or  1^  inch  diameter  in- 
side ;  B  18  a  glass  tube,  about  1  inch  diameter  outside,  drawn  to  a  point  at  bottom,  and 
shut  with  a  cork  at  top.  Tlirough  the  centre  of  this  cork,  the  small  tube  o  passes  down 
air-tight,  and  is  furnished  at  top  with  a  stop-cock,  into  which  the  bent  small  tube  of 
glass  (without  lead)  e  is  cemented.  The  bent  tube  f  is  joined  to  the  end  of  b  with 
a  collar  of  caoutchouc,  or  a  perforated  cork,  which  will  be  found  more  convenient 

The   manner  of  using  this  apparatus   is  as   follows :— -Introduce  a  few   oblong 
slips  of  zinc,   free  from  arsenic,   into  b,   and  then  insert  its  air-tight  cock  with 


ARSENIC. 


85 


suspected  liquid,  acidulated  with  dilute  hy- 
drochloric or  sulphuric  acid  (each  pure)  as 
will  rise  to  the  top  of  the  cork,  after  b  is 
full,  and  immediately  shut  the  stop-cock. 
The  generated  hydrogen  will  force  down 
the  liquid  out  of  the  lower  orifice  of  b  into  a, 
and  raise  the  level  of  it  above  the  cork.  The 
extremity  of  the  tube  f  being  dipped  be- 
neath the  surface  of  a  weak  solution  of  ni- 
trate of  silver,  and  a  spirit-flame  being  pla- 
ced a  little  to  the  left  of  the  letter  e,  the 
stop-cock  is  then  to  be  slightly  opened,  so 
that  the  gas  which  now  fills  the  tube  b  may 
escape  so  slowly  as  to  pass  olf  in  separate 
smaU  bubbles  through  the  silver  solution. 
By  this  means  the  whole  of  the  arsenic  con- 
tained in  the  arseniuretted  hydrogen  will  be 
deposited  either  in  the  metallic  state  upon 
the  inside  of  the  tube  e,  or  with  the  silver 
into  the  characteristic  black  powder.  The 
first  charge  of  gas  in  b  being  expended,  the 
stop-cock  is  to  be  shut,  till  the  liquid  be 
again  expelled  from  it  by  a  fresh  disengage- 
ment of  hydrogen.  The  ring  of  metallic  ar- 
senic deposited  beyond  e  may  be  chased  on- 
wards by  placing  a  second  flame  under  it, 
JVI/  and  thereby  formed  into  an  oblong  brilliant 

''"    -*'^  steel-like  mirror.     It  is  evident  that  by  the 

patient  use  of  this  apparatus  the  whole  ar- 
senic in  any  poisonous  liquid  may  be  collected,  weighed,  and  subjected  to  every 
kind  of  chemical  verification.  If  f  be  joined  to  e  by  means  of  a  perforated  cork,  it 
may  readily  be  turned  about,  and  its  taper  point  raised  into  a  position  such  as  when 
the  hydrogen  issuing  from  it  is  kindled,  the  flame  may  be  made  to  play  upon  a  sur- 
face of  glass  or  porcelain,  in  order  to  produce  the  arsenical  mirror. 

Or  the  preceding  process  may  be  made  supplementary  to  that  of  boiling  the  arse- 
nical foul  liquor,  acidulated  with  hydrochloric  acid  upon  slips  of  clean  copper,  whereby 
the  arsenic  is  precipitated  upon  the  copper  in  a  metallic  film  or  thin  crust  more  or  less 
brilliant  If  one  of  the  slips  of  copper  thus  coated  be  placed  in  the  tube  b  of  the 
above  described  apparatus,  it  will  give  off  its  arsenic  without  the  annoyance  pro- 
duced by  the  frothing  up  of  a  glutinous  mixture. 

Arsenic  {detection  of  y— It  is  now  generally  known  in  this  country,  that  towards 
the  close  of  last  year  Professor  Reinsch  has  proposed  an  entirely  new  method  of  detect- 
ing arsenic ;  which  consists  in  acidulating  any  suspected  fluid  with  hydrochloric  acid, 
heating  in  it  a  thin  plate  of  bright  copper,  upon  which  the  arsenic  is  deposited  in  the 
form  of  a  thin  metallic  crust,  and  then  separating  the  arsenic  from  the  copper  in  the 
state  of  oxide,  by  subjecting  the  copper  to  a  low  red  heat  in  a  glass  tube.  Organic 
fluids  and  solids,  suspected  to  contain  arsenic,  may  be  prepared  for  this  purpose  by 
boiling  them  for  half  an  hour  with  a  little  hydrychloric  acid ;  solid  matters  being  cut 
into  small  shreds,  water  being  added  in  suflBcient  quantity  to  let  the  ebullition  go  on 
quietly,  and  care  being  taken  to  continue  the  boiling  until  the  solids  are  either  dis- 
solved, as  generally  happens,  or  are  reduced  to  a  state  of  minute  division. 

Nothing  can  be  more  simple,  easy  or  precise  than  the  method  of  Reinsch.  It  is  also 
exceedingly  delicate,  more  so  than  is  ever  likely  to  be  necessary  in  any  medico-legal  in- 
vestigation ;  for  it  is  adequate  to  detect  a  250,000th  part  of  arsenic  in  a  fluid.  It  is 
also  perfect  in  another  respect :  it  does  not  leave  any  arsenic  in  the  subject  of  analysis; 
none,  at  least,  which  can  oe  detected  by  any  other  means,  even  by  the  most  debcate 
process  yet  proposed,  that  of  Mr.  Marsh. 

Cut  the  copper,  on  which  the  areenic  is  deposited,  into  small  chips,  so  that  they  may 
be  easily  packed  in  the  bottom  of  a  small  glass  tube,  and  apply  a  low  red  heat  A 
white  crystalline  powder  sublimes ;  and  if  this  be  examined  in  the  sunshine,  or  with  a 
candle  near  it  a  magnifier  of  four  or  five  powers  will  enable  the  observer  to  distinguish 
the  equilateral  triangles  composing  the  facets  of  the  octahedral  crystals,  which  are 
formed  by  arsenious  acid  when  it  sublimes.  Sometimes  the  three  equal  angles,  com- 
posing a  corner  of  the  octahedron,  may  be  seen  by  turning  the  glass  in  various  direc- 
tions. If  triangular  facets  cannot  be  distinguisned,  owing  to  the  minuteness  of  the 
crystals,  then  shake  out  the  copper  cliips,  close  the  open  end  of  the  tube  with  the 
finger,  and  heat  the  sublimed  powder  over  a  very  minute  spirit  lamp  flame,  chasing  it 


J 


u 


ARSENIC. 


tip  and  down  the  tube  till  crystals  of  adequate  size  are  formed.  Next  boil  a  little  di»- 
tiJled -water  in  the  tube  over  the  part  where  the  crystalline  powder  is  collected  •  and 
-when  the  solution  is  cold  divide  it  into  three  parts,  to  be  tested  with  ammoniacal 
nitrate  of  silver,  ammoniacal  sulphate  of  copper,  and  sulphuretted  hydrogen,  either  in 
the  state  of  gas  or  dissolved  in  water. 

In  boiling  organic  substances  in  the  weak  hydrochloric  acid  care  must  be  taken  to 
ascertain  that  there  is  a  decided  excess  of  acid  always  present.  Twofluidrachmsto  every 
8  oz.  of  hquid  are  in  general  sufficient;  but  if  the  organic  matter  be  an  animal  texture 
in  a  state  of  decay,  a  much  larger  quantity  of  acid  may  be  necessarv,  owing  to  the  pre- 
sence of  ammonia,  which  tends  gradually  to  neutralize  the  acid  as  the  solution  goes  on. 
Kemsch  does  not  advise  filtration  of  the  fluid  after  the  acid  has  acted  sufficiently  on  the 
subject  of  analysis.  But  notwithstanding  the  delay  occasioned  by  filtration,  this  seems 
to  me  advisable  inmost  instances,  otherwise  organic  particles  are  apt  to  attach  them- 
selves to  the  copper,  and  thus  give  rise  to  empyreuma,  when  the  metallic  arsenic  is 
driven  oflF  by  heat  The  most  convenient  form  for  using  the  copper  is  that  of  copper 
leaf;  but  ordinary  plates  of  copper  may  be  easily  made  of  any  degree  of  fineness  by 
immersing  them  for  a  time  in  dilute  nitric  acid.  Where  the  quantity  of  arsenic  in  the 
fluid  18  supposed  to  be  small,  nearly  half  an  hour  should  be  allowed  to  elapse  before 
the  copper  is  removed.  Before  applying  the  sulphuretted  hydrogen  as  a  test  to  the 
solution  of  the  sublimed  oxide,  the  solution  must  be  acidulated  with  hydrochloric  or 
acetic  acid.  In  every  case  the  whole  process  should  be  applied  in  the  first  instance 
to  distilled  water,  acidulated  with  the  hydrochloric  acid  to  be  employed  afterwards ; 
and  if  the  copper  be  tarnished,  a  purer  acid  must  be  obtained,  or  the  copper  must  be 
subjected  to  the  subsequent  steps  of  the  process,  in  order  to  ascertain  whether  the 
tarnishing  be  occasioned  by  arsenic  or  not. 

Arsenical  and  Antimonial  Spots  {distinguishing  reactions  ofl.—li  a  drop  of  bromine 
is  placed  on  a  saucer,  and  a  capsule  containing  arsenical  spots  inverted  over  it,  the  spots 
take  a  very  bright  lemon-yellow  tinge  in  a  short  time.  Antimonial  spots,  under  the  same 
circumstances,  are  acted  on  much  more  rapidly  (in  about  five  seconds  at  a  temperature 
of  52°  F.),  and  assume  an  orange  shade.  Both  become  colorless  if  exposed  to  the  air, 
and  are  again  restored  if  treated  with  a  strong  solution  of  sulphuretted  hydrogen.  The 
secondary  yellow  of  the  arsenical  spots,  as  observed  by  Lassaigne,  disappears  on  the  ad- 
dition of  ammonia,  whilst  that  of  antimonial  spots  remains  untouched.  A  concentrated 
solution  of  iodate  of  potash  turns  arsenical  spots  of  a  cinnamon-red,  and  dissolves  them 
almost  immediately.  On  antimonial  spots  it  has  no  visible  action  within  3  or  4  hours. 
Solution  of  the  hypochlorites  (chlorides)  of  soda  and  lime  and  chlorine  water  dissolve 
arsenical  spots  instantaneously,  leaving  those  of  antimony.  A  concentrated  solution  of 
the  chlorate  of  potash  gradually  acts  upon  arsenical  spots,  but  not  upon  those  of  anti- 
™oiiy.  The  nitroprusside  of  potassium,  on  the  other  hand,  slowly  dissolves  antimony, 
producing  no  perceptible  effect  upon  arsenic.  The  statement  of  Bischoff,  that  arsenicai 
spots  were  soluble,  antimonial  insoluble,  in  a  solution  of  the  chloride  of  sodium,  could 
not  be  verified,  as,  after  repeated  trials,  it  was  found  to  leave  both  not  perceptibly 
aff^ected.  The  chloride  of  barium,  the  hydrochlorate  and  the  sulphite  of  ammonia, 
afforded  likewise  no  distinguishing  action.  The  nitrate  of  ammonia  dissolves  arsenical 
more  rapidly  than  antimonial  stains.  Of  these  reactions  the  most  decisive  are  those 
of  iodate  of  potash,  hypochlorites  of  soda  and  lime,  and  fresh  chlorine  water. 

Arsenic,  Tin,  and  Antimony  [qualitative  detertnination  of). — Although  analytical 
chemistry  possesses  several  methods  of  distinguishing  between  tin,  antimony,  and  arse- 
nic, I  am  not  acquainted  with  any  process  by  which  these  three  metals,  when  they 
occur  together,  can  be  recognized  with  the  same  ease  and  quickness  as  in  the  case  of 
most  other  metals.  At  the  same  time,  the  frequent  occurrence  of  these  three  metals 
together  renders  a  quick  mode  of  detecting  them  highly  desirable.  The  following 
may  be  viewed  as  a  small  contribution  towards  this  object. 

With  regard  to  the  discrimination  of  tin  and  antimony,  this  is  founded  on  the  solu- 
bility of  metallic  tin  in  strong  muriatic  acid,  and  the  insolubility  of  antimonial  stains, 
obtained  according  to  Marsh's  method  in  hypochlorite  of  soda.  • 

When  the  muriatic  solution  of  the  two  metals  is  treated  with  some  metallic  zinc,  they 
are  both  precipitated,  the  antimony  with  disengagement  of  antiraoniuretted  hydrogen. 
When  the  precipitation  is  made  in  a  small  apparatus  for  the  disengagement  of  hydrogen, 
the  antimony  is  readily  detected  by  the  black  stains  insoluble  in  hypochlorite  of  soda, 
which  it  produces  upon  a  piece  of  porcelain.  When  subsequently  the  precipitated 
metallic  powder  of  tin  and  antimony  is  boiled  with  strong  muriatic  acid,  only  tin  dis- 
solves, forming  protochloride,  which,  after  subsequent  dilution  with  water,  is  recog- 
nized by  the  brownish-black  precipitate  produced  by  sulphuretted  hydrogen.  Neither 
of  these  reactions  are  modified  by  the  presence  of  arsenic. 

The  detection  of  arsenic  when  antimony  is  present,  is  founded  upon  a  remarkable 
difference  which  these  two  metals  exhibit  towards  nascent  hydrogen  when  the  latter  is 


ARTESIAN  WELLS. 


87 


disengaged  from  an  alkaline  liquid.  When  a  strong  alkaline  solution  of  antimony  is 
heated  with  metallic  zinc,  antimony  is  precipitated  simultaneously  with  a  lively  disen- 
gagement of  pure  hydrogen,  which  does  not  show  the  slightest  reaction  of  antimoniu- 
retted  hydrogen.  If,  on  the  contrary,  a  substance  containing  arsenic  acid  is  mixed  with 
an  excess  of  potash  and  some  finely-divided  zinc,  the  hydrogen  given  off  on  the  applica- 
tion of  heat  is  abundantly  charged  with  arseniuretted  hydrogen.  The  presence  of  this 
latter  is  ascertained  most  simply  by  holding  a  strip  of  paper  dipped  in  nitrate  of  silver 
over  the  arseniferous  mixture  of  potash  and  zinc ;  with  the  slightest  trace  of  arsenie 
the  paper  is  colored  distinctly  black. 

AKlfelAN  WELLS.  Under  this  name  is  designated  a  cylindrical  perforation, 
bored  vertically  down  through  one  or  njore  of  the  geological  strata  of  the  earth,  till  it 
passes  into  a  porous  gravel  bed  containing  water,  placed  under  such  incumbent  pressure 
as  to  make  it  mount  up  through  the  perforation,  either  to  the  surface  or  to  a  height  con- 
venient for  the  operation  of  a  pump.  In  the  first  case,  these  wells  are  called  spouting 
or  overflowing.  This  property  is  not  directly  proportional  to  the  depth,  as  might  at  first 
eight  be  supposed,  but  to  the  subjacent  pressure  upon  the  water.  We  do  not  know  ex- 
actly the  period  at  which  the  borer  or  sound  was  applied  to  the  investigation  of  subter- 
ranean fountains,  but  we  believe  the  first  overflowing  wells  were  made  in  the  ancieDt 
French  province  of  Artois,  whence  the  name  of  Artesian.  These  wells,  of  such  impor- 
tance to  agriculture  and  manufactures,  and  which  cost  nothing  to  keep  them  in  condition, 
have  been  in  use,  undoubtedly,  for  several  centuries  in  the  northern  departments  of  France, 
and  the  north  of  Italy ;  but  it  is  not  more  than  50  or  60  years  since  they  became  known 
in  England  and  Germany.  There  are  now  a  great  many  such  wells  in  London  and  its 
neighborhood,  perforated  through  the  immensely  thick  bed  of  the  I^ndon  clay,  and  even 
through  some  portions  of  the  subjacent  chalk.  The  boring  of  such  wells  has  given  much 
Insight  into  the  geological  structure  of  many  districts. 

The  formation  of  Artesian  wells  depends  on  two  things,  essentially  distinct  from  each 
other:  1.  On  an  acquaintance  with  the  physical  constitution,  or  nature,  of  the  mineral 
structure  of  each  particular  country  ;  and,  2.  On  the  skilful  direction  of  the  processes 
by  which  we  can  reach  the  water  level,  and  of  those  by  which  we  can  promote  its  ascent 
in  the  tube.  We  shall  first  treat  of  the  best  method  of  making  the  well,  and  then  offei 
some  general  remarks  on  the  other  subjects. 

The  operations  employed  for  penetrating  the  soil  are  entirely  similar  to  those  daily 
practised  by  the  miner,  in  boring  to  find  metallic  veins ;  but  the  well  excavator  must  re- 
sort to  peculiar  expedients  to  prevent  the  purer  water,  which  comes  from  deep  strata, 
mingling  with  the  cruder  waters  of  the  alluvial  beds  near  the  surface  of  the  ground,  as 
also  to  prevent  the  small  perforation  getting  eventually  filled  with  rubbish. 

The  cause  of  overflowing  wells  has  been  ascribed  to  a  variety  of  c'u-cumstances.  But, 
as  it  is  now  generally  admitted  that  the  numerous  springs  which  issue  from  the  ground 
proceed  from  the  infiltration  of  the  waters  progressively  condensed  in  rain,  dew,  snow, 
&c.  ui>on  the  surface  of  our  globe,  the  theory  of  these  interior  streamlets  becomes  by  no 
means  intricate ;  being  analogous  to  that  of  syphons  and  water  jets,  as  expounded  in  the 
treatises  on  physics.  The  waters  are  diffused,  after  condensation,  upon  the  surface  of  the 
soil,  and  percolate  downwards,  through  the  various  pores  and  fissures  of  the  geological 
strata,  to  be  again  united  subterraneously  in  veins,  rills,  streamlets,  or  expanded  films, 
of  greater  or  less  magnitude,  or  regularity.  The  beds  traversed  by  numerous  disjunctions 
will  give  occasion  to  numerous  interior  currents  in  all  directions,  which  cannot  be  re- 
covered, and  brought  to  the  day ;  but  when  the  ground  is  composed  of  strata  of  sand,  or 
gravel  very  permeable  to  water,  separated  by  other  strata  nearly  impervious  to  it,  reser- 
voirs are  formed  to  our  hand,  from  which  an  abundant  supply  of  water  may  be  spontane- 
ously raised.  In  this  case,  as  soon  as  the  upper  stratum  is  perforated,  the  waters  may 
rise,  in  consequence  of  the  hydrostatic  pressure  upon  the  lower  strata,  and  even  overflow 
the  smface  in  a  constant  stream,  provided  the  level  from  which  they  proceed  be  propor- 
tionally higher. 

The  sheets  of  water  occur  principally  at  the  separation  of  two  contiguous  formations; 
and,  if  the  succession  of  the  geological  strata  be  considered,  this  distribution  of  the  watei 
will  be  seen  to  be  its  necessary  consequence.  In  fact,  the  lower  beds  are  frequently 
composed  of  compact  sandstone  or  limestone,  and  the  upper  beds  of  clay.  In  level 
countries,  the  formations  being  almost  always  in  horizontal  beds,  the  waters  which  feed 
the  Artesian  wells  must  come  from  districts  somewhat  remote,  where  the  strata  are  more 
elevated,  as  towards  the  secondary  and  transition  rocks.  The  copious  streams  condensed 
upon  the  sides  of  these  colder  lands  maybe  therefore  regarded  as  the  proper  reservoirs  of 
our  wells. 


I 


li 


^1 


S8 


ARTESIAN  WELLS. 


^^^36  represents  the  maimer  in  which  the  condensed  water  of  the  heavens  diV 

oa  tributes  itself  under  the 

surface  of  our  globe. 
Here  we  have  a  geolo- 
gical section,  showing 
the  succession  of  the 
several  formations,  and 
the  sheets  or  lamince  of 
water  that  exist  at  their 
boundaries,  as  well  as  in 
their  sandy  beds.  The 
figure    shows    also    very 

— .■,-,^,---,-. ,■.-■,         plainly    that    the    height 

to  which  the  water  reascends  in  ihe  bore  of  a  well  depends  upon  the  height  of  the  r&. 
scrvoir  which  supplies  the  sheet  of  water  to  which  the  well  is  perforated.  Thus  the 
well  A,  having  gone  down  to  the  aqueous  expanse  a  a,  whose  waters  of  supply  are  de- 
rived from  tlie  percolation  m,  will  afford  rising  waters,  which  wiU  come  to  the  surface; 
while  in  the  well  b,  supphed  by  the  sheet  p,  the  waters  will  spout  above  the  surface, 
and  in  the  well  c  they  will  remain  short  of  it.  The  same  figure  shows  that  these  weUs 
olten  traverse  sheets  of  water,  which  rise  to  different  heights.  Thus,  in  the  well  c  there 
are  live  columns  of  ascending  waters,  which  rise  to  heights  proportional  to  the  points 
whence  they  take  their  origin.  Several  of  these  will  be  spouting  or  overflowing,  but 
gome  will  remain  beneath  the  surface. 

The  situation  of  the  intended  well  being  determined  upon,  a  circular  hole  is  generally 
dug  m  the  ground,  about  6  or  8  feet  deep,  and  5  or  6  feet  wide.  In  the  centre  of  this 
note  the  boring  is  carried  on  by  two  workmen  below,  assisted  by  a  laborer  above,  as 
saown  m  fig.  37. 

The  handle  (fig.  38)  having  a  female  screw  in  the  bottom  of  its  iron  shank,  with  a 
wooden  bar  or  rail  passmg  through  the  socket  of  the  shank,  and  a  ring  at  top,  is  the 
general  agent  to  which  all  the  boring  implements  are  to  be  attached.     A  chisel 


40     4] 


46 


39 


!1 


.\l 


ISi 


a 


48 


42 


38 


g 


47 


Si 


Tkf 


0 


(fig.  39)  is  first  employed,  and  connect^ 
to  this  handle  by  its  screw  at  top.  If  the 
ground  is  tolerably  soft,  the  weight  of  the 
two  workmen  bearing  upon  the  cross  bar,  and 
occasionally  forcing  it  round,  will  soon  cause 
the  chisel  to  penetrate  ;  but  if  the  ground  is 
hard  or  strong,  the  workmen  strike  the  chisel 
—  down  with  repeated  blows,  so  as  to  peck  Ijieir 
way,  often  changing  their  situation  by  walk- 
ing round,  which  breaks  the  stones,  or  other 
hard  substances,  that  may  happen  to  obstruct 
its  progress. 

The   labor  is  very   considerably   reduced 
by  means  of  an  elastic  wooden  pole,  placed 


Iwmontany  over  the  well,  from  which  a  chain  is  brought  down,  and  attached  to  the  ring 


ARTESIAN  WELLS. 


89 


of  the  handle.  This  pole  is  usually  made  fast  at  one  end,  as  a  fulcrum,  by  being  set 
into  a  heap  of  heavy  loose  stones ;  at  the  other  end  the  laborer  above  gives  it  a  slight 
up  and  down  vibrating  motion,  corresponding  to  the  beating  motion  of  the  workmen 
below,  by  which  means  the  elasticity  of  the  pole  in  rising  lifts  the  handle  and  pecker, 
and  thereby  very  considerably  diminishes  the  labor  of  the  workmen,     ^eefig.  37. 

When  the  hole  has  been  thus  opened  by  a  chisel,  as  far  as  its  strength  would  permit, 
the  chisel  is  withdrawn,  and  a  sort  of  cylindrical  auger  {fig.  40)  attached  to  the  handle 
(fig.  38),  for  the  purpose  of  drawing  up  the  dirt  or  broken  stones  which  have  been 
disturbed  by  the  chisel.  A  section  of  this  auger  is  shown  in^^.  41,  by  which  the  in- 
ternal valve  will  be  seen.  The  auger  being  introduced  into  the  hole  and  turned  round 
by  the  workmen,  the  dirt  or  broken  stones  will  pass  through  the  aperture  at  bottom 
(snown  at  fig.  42),  and  fill  the  cylinder,  which  is  then  drawn  up,  and  discharged  at 
the  top  of  the  auger,  the  valve  i)reventing  its  escape  at  bottom. 

In  order  to  penetrate  aeeper  into  the  ground,  an  iron  rod,  as  a,  fig.  43,  is  now  to 
be  attached  to  the  chisel,  fig.  39,  by  screwing  on  to  its  upper  end,  and  the  rod  is  also 
fastened  to  the  handle,  fig.  38,  by  screwing  into  its  socket.  The  chisel  having  thus 
become  lengthened  by  the  addition  of  the  rod,  it  is  again  introduced  into  the  holej 
and  the  operation  of  pecking  or  forcing  it  down,  is  carried  on  by  the  workmen  as  be- 
fore. When  the  ground  has  been  thus  perforated,  as  far  as  the  chisel  and  its  rod  will 
reach,  they  must  be  withdrawn,  in  order  again  to  introduce  the  auger,  fig.  40,  to  col- 
lect and  bring  up  the  rubbish  ;  which  is  done  by  attaching  it  to  the  iron  rod,  in  place 
of  the  chisel.  Thus,  as  the  hole  becomes  deepened,  other  lengths  of  iron  rods  are  added, 
by  connecting  them  together,  as  a  6  are  in  fig.  44.  The  necessity  of  frequently  with- 
drawing  the  rods  from  the  holes,  in  order  to  collect  the  mud,  stones,  or  rubbish,  and 
the  great  friction  produced  by  the  rubbing  of  the  tools  against  its  sides,  as  well  as  the 
lengths  of  rods  augmenting  in  the  progress  of  the  operation,  sometimes  to  the  extent  of 
several  hundred  feet,  render  it  extremely  inconvenient,  if  not  impossible,  to  raise  them 
by  hand.  A  tripedal  standard  is  therefore  generally  conslnicted  by  three  scaffolding 
poles  tied  together,  over  the  hole,  as  shown  fig.  37,  from  the  centre  of  which  a  wheel 
and  axle,  or  a  pair  of  pully  blocks  is  suspended,  for  the  purpose  of  hauling  up  the  rods, 
and  from  which  hangs  the  fork,^g.  45.  This  fork  is  to  be  brought  down  under  the  shoul- 
der, near  the  top  of  each  rod,  and  made  fast  to  it  by  passing  a  pin  through  two  little 
holes  in  the  claws.  The  rods  are  thus  drawn  up,  about  seven  feet  at  a  time,  which  is 
the  usual  distance  between  each  joint,  and  at  every  haul  a  fork,  fig.  46,  is  laid  hori- 
zontally over  the  hole,  with  the  shoulders  of  the  lower  rod  resting  between  its  claws,  by 
which  means  the  rods  are  prevented  from  sinking  down  into  the  hole  again,  while  the 
upper  length  is  unscrewed  and  removed.  In  attaching  and  detaching  these  lengths  of 
rod,  a  wrench,  fig.  47,  is  employed,  by  which  they  are  turned  Kjund,  and  the  screws  for- 
ced up  to  their  firm  bearing. 

The  boring  is  sometimes  performed  for  the  first  sixty  or  a  hundred  feet,  by  a  chisel 
of  2i  inches  wide,  and  cleared  out  by  a  gouge  of  2^  diameter,  and  then  the  hole  is 
widened  by  a  tool,  such  as  is  shown  at  fig.  48.  This  is  merely  a  chisel,  as  fig.  39,  four 
inches  wide,  but  with  a  guide,  a,  put  on  at  its  lower  part,  for  the  purpose  of  keeping 
it  in  a  perpendicular  direction ;  the  lower  part  is  not  intended  to  peck,  put  to  pass 
down  the  hole  previously  made,  while  the  sides  of  the  chisel  operate  in  enlarging  the 
hole  to  four  inches.  The  process,  however,  is  generally  performed  at  one  operation,  by 
a  chisel  of  four  inches  wide,  as  fig.  39,  and  a  gouge  of  three  inches  and  three  quarters. 
as,^g.  40.  *  ' 

It  is  obvious  that  placing  and  displacing  the  lengths  of  rod,  which  is  done  every  time 
that  the  auger  is  required  to  be  introduced  or  withdrawn,  must,  of  itself,  be  extremely 
troublesome,  independent  of  the  labor  of  boring,  but  yet  the  operation  proceeds,  when 
no  unpropitious  circumstances  attend  it,  with  a  facility  almost  incredible.  Sometimes, 
however,  rocks  intercept  the  way,  which  require  great  labor  to  penetrate ;  but  this  is 
always  effected  by  pecking,  which  slowly  pulverizes  the  stone.  The  most  unpleasant 
circumstance  attendant  upon  this  business  is  the  occasional  breaking  of  a  rod  into  the 
liol^,  which  sometimes  creates  a  delay  of  many  days,  and  an  incalculable  labor  in  draw- 
mg  up  the  lower  portion. 

When  the  water  is  obtained  in  such  quantities  and  of  such  quality  as  may  be  required, 
the  hole  is  dressed  or  finished  by  passing  down  it  a  diamond  chisel,  funnel  mouthed, 
with  a  triangular  bit  m  its  centre ;  this  makes  the  sides  smooth  previous  to  putting  in 
lae  pipe.  This  chisel  is  attached  to  rods,  and  to  the  handle,  as  before  described  ;  and, 
m  Its  descent,  the  workmen  continually  walk  round,  by  which  the  hole  is  made  smooth 
and  cylindrical.  In  the  progress  of  the  boring,  frequent  veins  of  water  are  passed 
inrough  ;  but,  as  these  are  smaU  streams,  and  perhaps  impresnated  with  mineral  sub- 
stances, the  operation  is  carried  on  until  an  aperture  is  made  into  a  main  spring,  which 
will  flow  up  to  the  surface  of  the  earth.  This  must,  of  course,  depend  upon  the  level  of 
its  source,  which,  if  m  a  neighboring  hill,  wiU  frequently  cause  the  water  to  rise  up, 
and  produce  a  continued  fountain.     But  if  the  altitude  of  the  distant  spring  happens  to 


i 


90 


ARTESIAN  WELLS. 


be  below  the  level  of  the  surface  of  the  CTonnd  where  the  boring  is  effected,  it  sometimes 
happens  that  a  m  eU  of  considerable  capacity  is  obliged  to  be  dug  down  to  that  level,  in 
order  to  form  a  reservoir,  into  which  the  water  may  flow,  and  whence  it  must  be  raisea 
by  a  pump;  while,  in  the  former  instance,  a  perpetual  fountam  may  be  obtaineU. 
Hence,  it  will  always  be  a  matter  of  doubt,  in  level  countries,  whether  water  can  be 
procured  which  would  flow  near  to  or  over  the  surface ;  if  this  cannot  be  ettected,  liie 
process  of  boring  wiU  be  of  little  or  no  advantage,  except  as  an  experiment  to  ascertain 

In  order  to  keep  the  strata  pure  and  uncontaminated  with  mineral  springs,  the  hole 
is  cased,  for  a  considerable  depth,  with  a  metallic  pipe,  about  a  quarter  of  an  inch 
Bmaller  than  the  bore.  This  is  generally  made  of  tin  (though  sometimes  of  copper  or 
lead)  in  convenient  lengths;  and,  as  each  length  is  let  down,  it  is  held  by  a  shoulder 
resting  in  a  fork,  while  another  length  is  soldere^to  it ;  by  which  means  a  conlmuous 
pipe  is  carried  through  the  bore,  as  far  as  may  be  found  necessary,  to  exclude  land  spricgs, 
and  to  prevent  loose  earth  or  sand  from  falling  in,  and  choking  the  aperture. 

Mr.  John  Good,  of  Tottenham,  who  had  been  extensively  employed   in  boring  the 
earth  for  water,  obtained  a  patent,  in  Aug.  1823,  for  certain  improved  implements  con- 
trived by  him  to  facilitate  his  useful  labors ;  a  description  of  which  cannot  fail  to  be  in- 
teresting. ,  , 
The  figures  annexed  exhibit  these  ingenious  tools ;  fifi.  49  is  an  auger,  to  be  connected 
52     51     50    49      by  the  screw-head  to  the  length  of  rods  by  which  the  boring  is  car- 
ried on.    This  auger  is  for  boring  in  soft  clay  or  sand ;  it  is  cylin- 
A'V      n     ft       drical,  and  has  a  slit  or  opening  from  end  to  end,  and   a  bit,  or 
U     Y       1 1      W       cutting.piece  at  bottom.     When  the  earth  is  loose  or  wet,  an  auger 
VI         I        I       of  the  same  form  is  to  be  employed,  but  the  slit  or  opening  reduced 
A  HTH  ITWH     in  width,  or  even  without  a  slit  or  opening.    A  similar  auger  is 
/>^  lUiUI  1^  ^  fc  J«     used  for  cutting  through  chalk ;   but  the  point  or  bit  at  bottom 

should  then  project  lower,  and,  for  that  purpose,  some  of  these 
cylindrical  augers  are  made  with  moveable  bits,  to  be  attached  by 
screws,  which  is  extremely  desirable  in  grinding  them  to  cutting 
edses.  Fig.  60  is  a  hollow  conical  auger,  for  bormg  loose  sandy 
soils ;  it  has  a  spiral  cutting  edge  coiled  round  it,  which,  as  it 
turns,  causes  the  loose  soil  to  ascend  up  the  inclined  plane,  and 

yJU    r&  deposite  itself  in  the  hollow  within.    Fig.  51  is  a  hollow  cylinder 

US!    If  or  tube,  shown  in  section,  with  a  foot-valve,  and  a  bucket  to  be 

raised  by  a  rod  and  cord  attached  at  the  top ;  this  is  a  pumping 
tool,  for  the  purpose  of  getting  up  water  and  sand  that  would  not 
rise  by  the  auger.  When  this  cylinder  is  lowered  to  the  bottom  of  the  bore,  the  bucket 
is  lifted  up  by  the  rod  and  cord,  and  descends  again  by  its  own  gravity,  having  a  valve 
in  the  bucket,  opening  upwards,  like  other  lift  pumps ;  which,  at  every  stroke,  raises  a 
quanlitv  of  water  and  sand  in  the  cylinder  equal  to  the  stroke  ;  the  ascent  and  descent  o! 
the  bucket  being  limited  bv  a  guide-piece  at  the  top  of  the  cylinder,  and  two  smaU  knob* 
upon  the  rod  which  stop  against  the  cross-guide.  Fig.  52  is  a  tool  for  getting  up  broken 
rods.  It  consists  of  a  small  cylindrical  piece  at  bottom,  which  the  broken  rod  slips  through 
when  it  is  lowered,  and  a  small  catch  with  a  knife-edge,  acted  upon  by  a  back-spring. 
In  rising,  the  tool  takes  hold  of  the  broken  rod,  and  thereby  enables  the  workman  at 
top  to  draw  it  up.  Another  tool  for  the  same  purpose,  is  shown  at  jig.  53,  which  is  like 
a  pair  of  tongs ;  it  is  intended  to  be  slidden  down  the  bore,  and  for  the  broken  rod  to  pass 
between  the  two  catches,  which,  pressed  by  back-springs,  will,  when  drawn  up,  take  fast 

hold  of  the  broken  rod.  „   .        v        *     v        j 

Fie.  54  is  a  tool  for  widening  the  hole,  to  be  connected,  like  all  the  others,  to  the  end 

of  the  length  of   rods   passed 
down   the   bore;   this  tool  has 
two  cutting-pieces  extending  on 
the  sides  at  bottom,  by  which, 
as  the  tool  is  turned  round  in 
the  bore,  the  earth   is  peeled 
away.    Fig.  65  is  a  chisel,  or 
punch,  with  a  projecting  piece 
to     be     used    for    penetrating 
through   stone;    this    chisel  is, 
by  rising  and  falling,  made  to 
peck  the  stone,   and  pulverize 
it ;  the  small  middle  part  break- 
ing it  away  first,  and  afterwards 
the  broad  part  coming  into  ac- 
tion.   Fig.  66  is  another  chisel, 
or  punching  tool,  twisted  on  its 
cutting  edge,  which  breaks  away 

a  greater  portion  of  the  stone  as  it  beats  against  it. 


<  ^1 


I 


* 


ARTESIAN  WELLS. 


91 


The  manner  of  forcing  down  lengths  of  cast-iron  pipe,  after  the  bore  is  formed,  is 
shown  at  fig.  67 ;  the  pipe  is  seen  below  in  the  socket,  at  the  end  of  which  a  block  is 
inserted ;  and  from  this  block  a  rod  extends  upwards,  upon  which  a   weight  at  top 
slides.     To  this  weight  cords  are  shown  to  be  attached,  reaching  to  the  top  of  the  bore  ; 
where  the  workmen  alternately  raise  the  weight  and  let  it  fall,  which,  by  striking  upon 
the  block  in  its  middle,  beats  down  the  pipe  by  a  succession  of  strokes ;  and  when  one 
length  of  pipe  has,  by  these  means,  been  forced  down,  another  leneth  is  introduced  into 
the  socket  of  the  former.     Another  tool  for  the  same  purpose  is  shown  &tfig.  58,  which 
is  formed  like  an  acorn ;  the  raised  part  of  the  acorn  strikes  against  the  edge  of  the 
pipe,  and  by  thai  means,  it  is  forced  down  the  bore.     When  it  happens  that  an  auger 
breaks  in  the  hole,  a  tool  similar  to  that  shown  at^g.  59  is  introduced;  on  one  side  of 
this  tool  a  curved  piece  is  attached,  for  the  purposeof  a  guide,  to  conduct  it  past  the 
cylindrical  auger ;  and  at  the  end  of  the  bther  side  is  a  hook,  which,  taking  hold  of  the 
bottom  edge  of  the  auger,  enables  it  to  be  drawn  up. 

Wrought  iron,  copper,  tin,  and  lead  pipes,  are  occasionally  used  for  lining  the  bore; 
and  as  these  are  subject  to  bends  and  bruises,  it  is  necessary  to  introduce  tools  for  the 
purpose  of  straightening  their  sides.  One  of  these  tools  is  shown  at  yig.  60,  which  is  a 
bow,  and  is  to  be  passed  down  the  inside  of  the  pipe,  in  order  to  press  out  any  dents. 
Another  tool,  for  the  same  purpose,  is  shown  at^g.  61,  which  is  a  double  bow,  aud 
may  be  turned  round  in  the  pipe  for  the  purpose  of  straightening  it  all  the  way  down  ; 
atfig.  62,  is  a  pair  of  clams,  for  turning  the  pipe  round  in  the  hole  while  driving. 

When  loose  stones  lie  at  the  bottom  of  the  hole,  which  are  too  large  to  be  brought  up 
by  the  cylindrical  auger,  and  cannot  be  conveniently  broken,  then  it  is  proposed  to 
introduce  a  triangular  claw,  Sisfig.  63,  the  internal  notches  of  which  take  hold  of  the 
stone,  and  as  the  tool  rises,  bring  it  up.  For  raising  broken  rods,  a  tool  like^g.  64 
is  sometimes  employed,  which  has  an  angular  claw  that  slips  under  the  shoulder  of  the 
rod,  and  holds  it  fast  while  drawing  up. 

In  raising  pipes  it  is  necessary  to  introduce  a  tool  into  the  insic'e  of  the  pipe,  by 
which  it  will  be  held  fast.  Fig.  65  is  a  pine-apple-tool  for  this  purpose ;  its  surface  is 
cut  like  a  rasp,  which  passes  easily  down  into  the  pipe,  but  catches  as  it  is  drawn  up ; 
and  by  that  means  brings  the  pipe  with  it.  Fig.  66  is  a  spear  for  the  same  purpose, 
which  easily  enters  the  pipe  by  springing;  at  the  ends  of  its  prongs  there  are  forks 
which  stick  into  the  metal  as  it  is  drawn  up,  and  thereby  raise  it. 

These  are  the  new  implements,  for  which  the  patent  was  granted.  In  the  process  of 
boring,  there  does  not  appear  to  be  anything  new  proposed ;  but  that  these  several 
tools  are  to  be  employed  for  boring,  packing,  and  otherwise  penetratin?,  raising  the 
earth,  and  extracting  broken  or  injured  tools.  There  are  also  suggestions  for  employing 
long  buckets,  with  valves  opening  upward  in  their  bottoms,  for  the  purpose  of  drawing 
watef  from  these  wells  when  the  water  will  not  flow  over  the  surface ;  also  lift  pumps, 
with  a  succession  of  buckets  for  the  same  purpose.  But  as  these  suggestions  possess 
little  if  any  novelty,  it  cannot  be  intended  to  claim  them  as  parts  of  the  patent. 

llie  older  geological  formations  are  seldom  propitious  to  the  construction  of  Arte- 
sian  wells,  on  account  of  the  compact  massiveness  of  their  rocks,  of  the  few  fissures 
or  porous  places  in  them,  and  of  the  rarity  of  filtering  strata  overiying  retentive  ones.  It 
18  therelore  vain  to  attempt  the  formation  of  an  overflowing  sprin?,  upon  the  above  prin- 
ciples, in  territories  of  granite,  gneiss,  mountain  limestone,  and  basalt.  Among  transition 
and  secondary  formations,  such  wells  will  rarely  furnish  a  supply  of  good  water.  The 
latter  strata  of  alternating  clay  and  variegated  sandstone  contain  so  much  gypsum  and 
rock  salt  as  to  impregnate  therewith  the  waters  derived  from  them  to  an  unpalatable 
'F^a'  *u  *f  ^"  ^^®  ^^^^^'  calcareous,  and  argillaceous  strata  of  the  Jura  limestone, 
indeed,  that  borings  may  most  probably  be  made  for  brine  springs.  The  hot  springs 
Which  burst  out  of  the  ground  in  primitive  rocky  districts  come  undoubtedly  from  a 
great  depth  under  the  surface,  and  derive  their  temperature,  and  also  probably  their 
waters,  frona  the  vapors  of  deep-seated  volcanoes  in  connexion  with  the  sea.  A  miniature 
representation  of  such  springs  is  exhibited  in  the  intermitting  fountains  of  fresh  water 
on  the  shoulder  of  Vesuvius.  Springs  of  this  kind,  which  vary  with  the  seasons,  may  de- 
rive a  portion  of  their  water  from  the  surface  of  the  earth,  from  which  it  may  sink  through 
clelts  m  the  primitive  rocks,  till  meeting  in  its  descent  with  stony  obstructions  and  ascend- 
ing steam,  it  is  forced  to  remount  in  a  heated  state  to  the  day,  like  the  Geisers  in  Iceland. 
1  he  most  remarkable  example  of  an  Artesian  well  is  that  recently  formed  at  Crenelle, 
a  suburb  at  the  southwest  of  Paris,  where  there  was  a  great  want  of  water.  It  cost 
eight  years  of  difficult  labor  to  perforate.  The  geological  strata  round  the  French 
capital  are  all  of  the  tertiary  class,  and  constitute  a  basin,  like  that  shown  in  fig.  67 
Ihe  bottom  of  this  basm  is  chalk  ;  a  a  are  tertiary  strata  above  the  chalk ;  b  b,  chalk 
or  cretaceous  carbonate  of  lime ;  c  c,  d  d,  green  sand  and  clay;  e  e,  oolite  and  Jura 
limestone  {muschelkalk)  ;  e  a,  general  slope  of  the  surface  of  the  country  from  Langrea 
to  Fans ;  m  a,  the  level  of  the  sea.    Over  a  circular  space,  of  which  Paris  is  the  centre 


t 


n 


92 


ARTESIAN  WELLS. 


S^teSSSSS£SSS2 


Pahs 

I 


Nogent- 
sur-    troyes.  Bar-sur- 

Provms.    Seine.  Lusigny.   Seine. 


67 


Plateau  de  Langres. 


vel,  pebblcsC  and  fragments  oc\oT^^bhavIt.T^       ^^  fl^^tu"  """^^^  "'S^ 
period  anterior  to  any  historical  re  Jrdn^lT,wtt-  '^*P'^'*«'l'>y  *•>«  waters  at  some 

^ttd^etlXfe^iiHSlttS^^^ 

l:^^^lb^rra:,tf^^;r/rH-dS^^^ 

tic  clay,  and  finally  chalk  which  fonm  f  h  J  kS/T       Au  ^'^  P^^*^?*^  pure  gravel,  plas- 
have  slen.     Is^o  caiculaS^'n  frl  georj^'l  ^^tl^^^  tertiary  basin.  aS  we 

stratum  of  chalk  whioh   /'J^^.  geological  data  could  determine  the  thickness  of  this 

perabTobstacle      Thel' rienee  acluir.^  ''^^^  ^'''''''  «°  ^^^^'^  i°««- 

f  ours,  was  in  this  respectTut  a"^^^^  l^Z^  Xr«^''  ''  ?'^:;:''  \^"^°'  ^'^^ 

be  overcome,  was  he  sure  of  finS  rsu^nl v  nf  ^  „/  ?  .  «»^PPo«'ng  th.s  obstacle  to 
the  first  place,  the  strata  cd  below^tL  KY  ^  "t^^,t)elow  this  mass  of  chalk  ?  In 
sary  conditions  for  producing  A  trsian  ^^r^S""""''^^'  ^  ^"  ^^«"  «^^  °"  ^^^  "««««■ 
gravel,  or  of  perviorSimperv?orbe^ds^M  aI"i^'  «"^«^r"?  ^"^'"^  «^^^*7  »°<i 
mer  experience  of  the  bodnTs  of  IhTlpIlf^f  ^"  ^^«^«t,/^o°fidently  relied  on  his  for- 

dant  supplies  of  water  harb?enflundbelowfhr?^v^^^^^  ""^  ?^""^'  ^^^^«  ''bun- 
and  gravel.  ^^^"""^  ^^^  '^^'^^^'  between  similar  strata  of  clay 

wernre&^^^^^^^^^  water  in  an  Artesian 

the  bore  above  which  thrwali  Is  jLoendT^^  '  v!""^^  ^'  ^'^^''  **^"^  ^^'^  ^^''^^^  i« 
with  Crenelle.  M.  AragoTad  shown  th^tthJw;  '"'"A? "'  *"'-""^  ^"<^  *^  ^^  ^^^^  <^^«« 
sarily  rise  to  the  8urfec/be<^tv  ^^'^  ^«"><i  °««es- 

the  level  of  the  sea,  the  wateTrLe   from  I?  to^Q  i  ^S  '  1^''^'  't  °"^"^^  ^  >'^^^«  ^^ove 

and,  consequently^fromlet  lT;IX.t': ZlZttVJ  ^'NoTt'th'  ''V'^^^;.' 
the  bore  at  Grenelle  is  only  34  yards  above  tht^LZTtlJ  •:  *  i,      '  ^^  ^^^  *""'^^^  ^^ 
tical  spring  be  met  with,  L  ^l^erl^uZV^^^^^^ 
The  necessary  works  were  onmm^nn^A  ^;*k  u    -     "-"e  eaitns  suitace  at  Grenelle. 

to  each  other,  anZtirco^rb^'ra   fdZ'^wTel-'b^^^^^^  '""«•  """."-O 

ingenious  method  was  adopted  for  t^ivin^r  fiwi.  «  ?  ;^  mechanical  power,  while  an 

the  bore  was  about  6  inches^  ThTinft^men^.ffil'T.*?!,  "^""^Tr  ^^^  '^^^"^'^^^  «f 
rod  was  changed  according  t^  the  differrt  l«f  t'l^^^  '"^  ^^^^^  ^^^^^^  ^""g" 
the  form  suited  for  passin^throu^h  th!  ^^f/  .  ""-^'i^^  "^^'^  successively  attacked ; 
able  for  boring  throStfe  chalk  and  flinr.Tn  1  "'^t  T'  '^'^  ^"''^"^^  ^^'"^  «°«"'t- 
while  a  chiseUhaped  tool  was  emnlo^^^^^  "««^  ^<''  the  former, 

was  lessened  as  th^  depth  ircTeasTJnd  BrnSfthpt  ,1^'  ^'""'-  ^"  ^'^^  °^  *»^«  ^«<1« 
so  soon  as  was  expecte^d,  it  bermrrequisre^^^^^ 

of  the  bore,  in  order  to  permit  the  work  to  be  suoiS  u^  ''''^''*^  ^'^^^  *^^  diameter 
curred  which  tried  the  patience  of  rhepi^^ctorsT^^^^^^^  ..^f  ^^'^'^  ^^■ 

extended  down  to  a  depth  of  418  yards  thrSw  tnbl^4-fi?  '  ^i^°  *^^  ^^""^  *^»d 
long  rods  attached  to  i^,  broke  and  kll  to  the  Wo m  of  7^'*^^'^^^^  ^^^^^  «^^^« 
necessary  to  extract  the  broken  parts  before  any  fultheinl  ^^''  ""^T^  '^  ^^^^"« 
difficulty  of  accomplishing  this  task  mat  be  cW  ved  ?  fo^^^^^^^  could  be  made.  Tlie 
were  not  all  extracted  until  after  the  constrnriabor  nf  i  /  fu  ^^'^^""^"^  fragments 
1840,  in  passing  through  the  chali,  t^e'Z:^tl:^Zt\T^^^^^^^ 


I 


ARTESIAN"  WELLS. 


98 


and  before  it  could  be  recovered,  several  months  were  spent  in  digging  round  about 
it.  A  similar  occurrence  created  an  obstacle  which  impeded  the  work  for  3  months, 
but,  instead  of  withdrawing  the  detached  part^  it  was  f#rcibly  driven  down  among  the 
stratum  of  gravel.  At  length,  in  February,  1841,  after  eight  years'  labor,  the  rods 
suddenly  descended  several  yards,  having  pierced  into  the  vault  of  the  subterranean 
water  so  long  sought  after  by  the  indefatigable  engineer.  A  few  hours  afterwards  he 
was  rewarded  for  all  his  anxious  toils ;  for  lo !  the  water  rose  to  the  surface,  and  dis- 
charged itself  at  the  rate  of  600,000  gallons  per  hour! 

The  depth  reached  down  was  602  yards,  or  about  three  times  the  height  of  St.  Paul's. 
The  pipe  by  which  the  water  reaches  the  surface  has  been  recently  carried  to  a  height 
nearly  level  with  the  source  of  supply.  The  portion  of  the  pipe  above  the  ground  is 
surrounded  with  a  monumental  pagoda  of  ornamental  carpentry,  and  it  discharges  a 
circular  cascade  of  clear  water  continually  into  a  circular  iron  reservoir,  to  be  thence 
conveyed  by  a  lateral  pipe  to  the  ground.  The  water  is  well  adapted  for  all  domestic 
uses,  and  it  will  be  unfailing,  being  supplied  from  the  infiltration  of  a  surface  of  coun- 
try nearly  200  miles  in  diameter.  The  Artesian  wells  of  Elbeuf,  Rouen,  and  Tours, 
which  were  formed  many^  years  ago,  overflow  in  never-varying  streams  ;  and  the  an- 
cient Artesian  well  at  Lillers,  in  the  Pas  de  Calais,  has  for  about  seven  centuries  fur- 
nished a  constant  and  equable  supply. 

The  opportunity  of  ascertaining  the  temperature  of  the  earth  at  different  depths 
was  not  neglected  during  the  progress  of  the  works  at  Grenelle.  Thermom<iter3 
placed  at  a  depth  of  30  yards  in  the  wells  of  the  Paris  Observatory  invariably  stand 
at  63°  Fahrenheit.  In  the  well  at  Grenelle  the  thermometer  indicated  74°  Fahr.  at  a 
depth  of  442  yards,  and  at  550  yards  it  stood  at  19°.  At  the  depth  finally  arrived  at 
of  602  yards,  the  temperature  of  the  water  which  rose  to  the  surface  was  81°,  corrob- 
orating previous  calculations  on  the  subject.  For  a  descent  of  572  yards  there  is  an 
increase  of  temperature  equal  to  28°  F.,  which  is  20*4  yards,  or  61  2  feet  for  each  de- 
gree of  that  scale.  Now  that  the  skilful  labor  of  so  many  years  is  terminated,  the 
Parisians  regret  that  the  subterranean  sheet  of  water  had  not  lain  1000  yards  beneath 
the  surface,  that  they  might  have  had  an  overflowing  stream  of  water  at  104°,  to  fur- 
nish a  cheap  supply  to  their  numerous  hot-bath  establishments. 

In  boring  Artesian  wells  through  stratified  formations,  several  sheets  of  water  are 
naet  with  at  successive  heights ;  as  at  St.  Ouen  there  are  5,  each  capable  of  rising :  one 
of  these  is  at  36  metres  of  depth;  a  second  at  45im.,  a  third  at  51  |m.,  a  fourth  at 
59-30m.,  and  a  fifth  at  66Jm.  At  Tours  there  are  3  sheets  susceptible  of  mounting 
at  96,  102,  and  125  metres  respectively  beneath  the  surface.  Seven  large  sheets  of 
Iresh  water  were  in  like  manner  observed  in  boring  for  coal  near  Dieppe.  The  deep- 
est sheets,  having  the  greatest  superincumbent  pressure,  in  general  give  the  highest 
hydrostatic  level  The  quantity  of  water  furnished  by  such  wells  seems  to  be  nearly 
constant:  thus  the  well  of  Grenelle,  near  Paris,  continues  to  deliver  3000  litres  per 
minute  at  the  surface  of  the  ground;  the  well  of  Bages,  near  Perpignan,  2000  litres: 
that  at  Tours,  1110  at  2  metres  above  the  level  of  the  ground.  It  is  said  that  some 
ol  the  Artesian  wells  in  and  round  about  London  do  not  deliver  so  much  water  as 
they  formerly  did;  a  deficiency  ascribed  to  the' vast  quantities  which  have  been 
drawn  up  from  the  lower  sheets  of  water  by  the  multitude  of  steam  engines  employed 
m  pumping  When  a  copious  flow  of  water  from  a  deep  well  can  be  commandei  it 
may  be  used  for  driving  water  wheels  with  great  advantage,  since,  from  its  elevated 
temperature,  it  is  not  liable  to  freeze ;  and  for  the  same  reason  it  is  made  to  maintain 
*  "JoiiS^P^''.^)'''?  by  circulating  in  pipes  through  the  interior  of  factories. 

A^TT^f  'r^'^r  .^^"^  P^^^^f ^''  '^^'''^  '^  ^^  ^^^*  obtained  from  the  ashes  of  plants. 
A^siiii-S  Ut  FLANIb ;  see  Agriculture. 

ASHES,  PEARL  AND  POT,   SCC  PoTASH. 

Qo't'F^?^^J??«'  *  ^^rystallizable  product  extracted  from  asparagus,  consisting  of 
?r2M"  V^^?  ^'^^''  ^t^  hydrogen,  and  42-32  oxygen.  It  is  most  easily  procured 
from  the  roots  of  marsh-mallows.  It  is  a  curious  substance,  but  hitherto  has  been  ap- 
plied  to  no  use.  ^^ 

ASPHALTIC  PAVEMENT;  see  Bitumen. 

ASPHALTUM      Native  bitumen,  so  called  from  the  lake  Asphaltites. 

AbbAY  and  ASSAYING.  (Coupellation,  Fr. ;  Abtreiben  auf  der  capelle.  Germ.) 
inis  18  the  process  by  which  the  quality  of  gold  and  silver  bullion,  coin,  plate,  or 
trmkets,  is  ascertained  with  precision.       •'        °  .         ,  i'       . 

Jw'l  tu*  of  assaying  gold  and  silver  by  the  cupel  is  founded  upon  the  feeble  affinity 
wnicn  these  metals  have  for  oxygen,  in  comparison  with  copper,  tin,  and  the  other 
Cheaper  metals ;  and  on  the  tendency  which  the  latter  metals  have  to  oxidize  rapidly 
in  contact  with  lead  at  a  high  temperature,  and  sink  with  it  into  any  porous,  earthy 
vessel  in  a  thin,  glassy,  or  vitriform  state.  The  porous  vessel  may  be  made  either  of 
wood-ashes,  freed  from  their  soluble  matter  by  washing  with  water:  or,  preferably 
of  burned  bones  reduced  to  a  fine  powder  '      »  i'  ^  ciauiy, 


■■ 


1 


94 


ASSAY. 


AUoy. 

Lead  for  1  of  Alloy. 

Ratio  of  the  Copper  to 
the  Lead. 

Silver. 

Copper. 

•      1000 
950 
900 
800 
700 
600 
600 
400 
300 
200 
100 

0 

0 
50 

100 
200 
300 

400 
600 
600 
700 
800 
900 
1000 

^1 

7 
10 
12 

14 

16  or  17 
16  — 17 
16  —  17 
16  —  17 
16  —  17 
16  —  17 

0 

1  :  60 
1  :  70 
1  :  50 
1  :  40 
1  :  35 
1  :  32 
1  :  26-7 
1  :  22-9 
1  :  20 
1  :  17-8 
1  :  16 

Bismuth  may  be  used  as  a  substitute  for  lead  in  cupellation ;  two  parts  of  it  being 
nearly  equivalent  to  three  of  lead.  But  its  higher  prices  will  prevent  its  general 
introduction  among  assay  masters. 

We  begin  this  assay  process  by  weighing,  in  a  delicate  balance,  a  certain  weight  of 
the  metallic  alloy;  a  gramme  (=1 5*444  gr.)  is  usually  taken  in  France,  and  12  grains 
in  this  country.  This  weight  is  wrapped  up  in  a  slip  of  lead  foil  or  paper,  should  it 
consist  of  several  fragments.  This  small  parcel,  thus  enveloped,  is  then  laid  in  a  watch 
glass  or  a  capsule  of  copper,  and  there  is  added  to  it  the  proportion  of  lead  suited  to 
the  quality  of  alloy  to  be  assayed ;  there  being  less  lead,  the  finer  the  silver  is  presumed 
to  be.  Those  who  are  much  in  the  habit  of  cupellation  can  make  good  guesses  in  this 
way ;  though  it  is  still  guess  work,  and  often  leads  to  considerable  error,  for  if  too 
much  lead  be  used  for  the  proportion  of  baser  metal  present,  a  portion  of  the  silver 
is  wasted ;  but  if  too  little,  then  the  whole  of  the  copper,  &c.  is  not  carried  off,  and 
the  button  of  fine  silver  remains  more  or  less  impure.  The  most  expert  and  experienced 
assayer  by  the  cupel,  produces  merely  a  series  of  approximate  conjectural  results  which 
fall  short  of  chemical  demonstration  and  certainty  in  every  instance.  The  lead  must  be, 
in  all  cases,  entirely  free  from  silver,  being  such  as  has  been  revived  from  pure  litharge ; 
otherwise  errors  of  the  most  serious  kind  would  be  occasioned  in  the  assays. 

The  best  cupels  weigh  12|  grammes,  or  193  grains.  The  cupels  allow  the  fused 
oxydes  to  flow  through  them  as  through  a  fine  sieve,  but  are  impermeable  to  the 
panicles  of  metals ;  and  thus  the  former  pass  readily  down  into  their  substance  while 
the  latter  remain  upon  their  surface  ;  a  phenomenon  owing  to  the  circumstance  of  the 
glassy  oxydes  moistening,  as  it  were,  the  bone-ash  powder,  whereas  the  metals  can 
contract  no  adherence  with  it.  Hence  also  the  liquid  metals  preserve  a  hemispherical 
shape  in  the  cupels,  as  quicksilver  does  in  a  cup  of  glass,  while  the  fused  oxyde  spreads 
over,  and  penetrates  their  substance  like  water.  A  cupel  may  be  regarded,  in  some 
measure,  as  a  filter  permeable  only  to  certain  liquids. 

If  we  put  into  a  cupel,  therefore,  two  metals,  of  which  the  one  is  unalterable  in  the 
air,  the  other  susceptible  of  oxydizement,  and  of  producing  a  very  fusible  oxyde,  it  is 
obvious  that,  by  exposing  both  to  a  proper  degree  of  heat,  we  shall  succeed  in  separating 
them.  We  should  also  succeed,  though  the  oxyde  were  infusible,  by  placing  it  in  contact 
with  another  one,  which  may  render  it  fusible.    In  both  cases,  however,  the  metal  from 

which  we  wish  to  part  the  oxydes  must  not  be  volatile ;  it 
should  also  melt,  and  form  a  button  at  the  heat  of  cupel- 
lation ;  for  otherwise  it  would  continue  disseminated,  at- 
tached to  the  portion  of  oxyde  spread  over  the  cupel,  and 
incapable  of  being  collected. 

The  furnace  and  implements  used  for  assaying  in  the 
Royal  Mint  and  the  Goldsmiths*  Hall,  in  the  city  of  Lon- 
don, are  the  following  : — 

AAA  A,  fig.  68,  is  a  front  elevation  of  an  assay  furnace ; 
a  a,  a  view  of  one  of  the  two  iron  rollers  on  which  the  fur- 
nace rests,  and  by  means  of  which  it  is  moved  forward  or 
backward ;  6,  the  ash-pit ;  c  c  are  the  ash-pit  dampers, 
which  are  moved  in  a  horizontal  direction  towards  each 
Other  for  regulating  the  draught  of  the  furnace;  d,  the 
door,  or  opening,  by  which  the  cupels  and  assays  are  intro- 
duced  into  the  muffle ;   c,  a  moveable  funnel  or  chimney 


68 


i 


5^ 


O 

e 


O 
c 


JLB 


by  which  the  draught  of  the  furnace  is  increased. 


ASSAY. 


95 


*  "  ^fig'  69,  is  a  perpendicular  section  of  fig.  68 ;  a  a,  end  view  of  the  rollers ; 
69  b  the  ash-pit ;  c  one  of  the  ash-pit  dampers ;    d  the 

grate,  over  which  is  the  plate  upon  which  the 
muffle  rests,  and  which  is  covered  with  loam  nearly 
one  inch  thick;  /  the  muffle  in  section  represent- 
ing the  situation  of  the  cupels ;  g  the  mouth-'plate. 
and  upon  it  arc  laid  pieces  of  charcoal,  which  during 
the  process  are  ignited,  and  heat  the  air  that  is 
allowed  to  pass  over  the  cupels,  as  will  be  more 
fully  explained  in  the  sequel;  h  the  interior  of  the 
furnace,  exhibiting  the  fuel. 

The  total  height  of  the  furnace  is  2  feet  6|  inches; 
from  the  bottom  to  the  grate,  6  inches;  the  grate, 
muffle,  plate,  and  bed  of  loam,  with  which  it  is 
covered,  3  inches;  from  the  upper  surface  of  the 
^ate  to  the  commencement  of  the  funnel  e,  fig.  68, 
21  j^  inches;  the  funnel  e,  6  inches.  The  square 
of  the  furnace  which  receives  the  muffle  and  fuel 
is  llf  inches  by  15  inches.  The  external  sides  of  the  furnace  are  made  of  plates  of 
wrought  iron,  and  are  lined  with  a  2-inch  fire-brick. 

c  c  c  Cffig.  70,  is  a  horizontal  section  of  the  furnace  over  the  grates  showing  the  width 
_  70  ^  of  the  mouth-piece,  or  plate 

"1         ^<.^^T^>v       of    wrousht    iron,    which 


IS 


6  inches,  and  the  opening  which 
receives  the  muffle-plate. 

Fig.  71,  represents  the  muf- 
fle or  pot,  which  is  12  inches 
long,  6  inches  broad  inside; 
in  the  clear  6f  :  in  height  4| 
inside  measure,  and  nearly  5| 
in  the  clear. 

Fig.  72,  the  muffle-plate,  which  is  of  the  same  size  as  the  bottom  of  the  muffle. 

Fig.  13,  is  a  representation  of  the  sliding-door  of  the  mouth-plate,  as  shown  at  d,  in 


fig.  68. 


69 


(iUEilSHIii] 


ISSSSIIii] 


l3i](^^S{35l 


?6](77](li]|^l^ 


\2iMMEm 


EEOEEilll 


20 


EQfiigiiiTs] 


mmmEcio] 


mmiiimm 


Fig.  74,  a  front  view  of  the  mouth-plate  or  piece,  d,fig.  58. 

Ptg.  75,  a  representation  of  the  mode  of  making,  or  shutting  up  with  pieces  of  char- 
coal, the  mouth  of  the  furnace. 

Fig.  76,  the  teaser  for  cleaning  the  grate. 

Fig.  77,  a  larger  teaser,  which  is  introduced  at  the  top  of  the  furnace,  for  keepin*'  a 
complete  supply  of  charcoal  around  the  muffle.  "^ 

Fig.  78,  the  tongs  used  for  charging  the  assays  into  the  cups. 

Fig  79,  represents  a  board  of  wood  used  as  a  register,  and  is  divided  into  45  equal 
compartments,  upon  which  the  assays  are  placed  previouslv  to  their  being  introduced 
into  the  furnace.  When  the  operation  is  performed,  the  cupels  are  placed  in  the  furnace 
in  situations  corresponding  to  these  assays  on  the  board.  By  these  means  all  confusion 
IS  avoided,  and  without  this  regularity  it  would  be  impossible  to  preserve  the  accuracy 
which  the  delicate  operations  of  the  assayer  require. 

I  shall  now  proceed  to  a  description  of  a  small  assay  furnace,  invented  by  Messrs. 
Anfrye  and  d'Arcet,  of  Paris.  They  term  it,  Le  Petit  Foumeau  a  Coupelle.  Fig.  80 
represents  this  furnace,  and  it  is  composed  of  a  chimney  or  pipe  of  wrought  iron  a,  and 
of  the  furnace  b.  It  is  17J  inches  high,  and  7f  inches  wide.  The  furnace  is  formed 
Of  three  pieces ;  of  a  dome  a  ;  the  body  of  the  furnace  b  ,•  and  the  ash-pit  c,  which  is 


1 

1 

1 

1 

I                     i 

J  ■                 i 

I 

1 J 


ff 


:,|i"' 


96 


ASSAY. 


used  as  the  base  of  the  furnace,  figs.  80  and  81.  The  principal  piece,  or  body  of  the 
furnace,  b,  has  the  form  of  a  hoUow  tower,  or  of  a  hoUow  cylinderf  flat  ened^uaUv  ut 
the  wo  opposite  sides  parallel  to  the  axis,  in  such  a  manner  that  the  hSmTsecUon 
IS  elliptical.  The  foot  which  supports  it  is  a  hollow  truncated  cone  CS  inTe 
manner  upon  the  two  opposite  sides,  and  having  consequently  for  its  basis  two  eUipses 

of    diflferent    diamew 
ters  ;     the     smallest 
ought  to  be  equal  to 
that  of  the  furnace, 
so  that  the  bottom  of 
the  latter  may  exactly 
fit  it.      The    dome, 
which  forms  an  arch 
above    the    furnace, 
has  also  its  base  ellip> 
tical,  while   that  of 
the    superior    orifice 
by  which  the  smoke 
goes  out  preserves  the 
cylindrical  form.  The 
tube  of  wrought  iron 
is  18  inches  long  and 
2^    inches    diameter, 
having  one  of  its  ends 
a  little  enlarged,  and 
slightly  conical,  that 
it    may    be     exactly 
5     fitted  or  jointed  upon 
the    upper    part    of 
the  furnace  dome  d, 
fig.  80.   At  the  union 
of  the    conical   and 
cylindrical    parts   of 
the    tube,    there     is 
placed   a  small  gal- 
lery of  iron,  e,fig.  80, 
81.    See  also  a  plan 
of  it,  fig.  82.    This 
gallery  is    both    in- 
genious   and   useful. 


t^P  A,;L.!  ?L  ??/       '"^v ''  ""^'''^  ^'^.  ^^""^  «""^^'^  '^""n?  the  ordinary  work  of 
nrLprZ'       Vv.'^'°^^A^  ^"^«  ^^'  inuflle,wheS  it  is  brought  mto  hs 

11211  ?h! T  ^''''•mI  ^."^'  .^^""''f  ^^''  ^^"^^y  i^  ^  <Jo«r/,  by  whichf  if  though? 
Ta^throttl  V  r°^  rf'  ^^  ^"!'«d"ced  into  the  furnace;  above  that  there  is  placed  a 
ffll  A  r^^""^^  75J?  ''  "'^  ^""^  regulating  the  draught  of  the  furnace  at  pleasure 
^?«?*  t  UfyJ''"^  ^  '^''?  '^^?  ^^^^*  '°  S^^«  the  furnace  the  necessary  degree^f  S 
ZL^  T^  the  assays  of  gold,  the  tube  must  be  about  18  inches  above  the  galW 
for  anneahng  or  heating  the  cupels.  The  circular  opening  h,  in  the  dome,^^.  80  S 
lir^'JI'.'^-  ''''r^fi^'  ^h  ^  ^'^  to  introduce  the  ch^coal  into  the  f  raace :  iUs 
m^fflr    T^'"'^"'  '^'"?'""V^'^^"™^^^'^^d  to  arrange  the  charcoal  round    he 

Spfp  nrwh-'i??r'?^  ''>'P'  '^"^  ^"r^  ^^^  ^«^^^°&  «^  the  furnace,  with  the  mouth! 
piece,  of  which  the  face  is  seen  at  n,fig.  81.  ^»^ui 

thaT^lff  thfZffll^^?.^"'"r^'/^;  ?^' P^^s^jjts  several  openings,  the  principal  of  which  is 
that  of  the  muffle ;  it  is  placed  at  t ;  it  is  shut  with  the  semicircular  door  L  fiR.  80  and 

Xrthe'drnr.r'  ^%  ?'•  !r  ^^i  ^^  '"^^  ^P^^^^^^  ^^  the  taWe  or  she^;Cn 
fwil  c-^r    ^     ^'""^!'''"?^t^°^*^'^^'^^^^  the  letter  q,  fig,  81,  sh^s 

dlffl^Hpr'tr  r?f  •''''i'"-^^  ^^f  ',^""''  ^^'^»^  °^^^s  P«rt  of  the  fumlce.  Imm^ 
n^  nfthplrlt  f '  ^s  a  horizontal  sUt,  /,  which  is  pierced  at  the  level  of  the  upper 
part  of  the  grate,  and  used  for  the  mtroduction  of  a  slender  rod  of  iron,  that  the  erate 

aT^,%rfo:iT8^^-    ™^^^^^^"^  ^^  ^^^^  at  pleasure,  by  the  wed Je  rl^r^f^^ 
Upon  the  back  of  the  furnace  is  a  horizontal  slit/,,  fig.   81,  which  supports  the  fii«. 
brick,  *,  and  upon  which  the  end  of  the  muffle,  if  necessary,  may  rest :  u.fig.  81,  isX 
opening  m  the  furnace  where  the  muffle  is  placed.  "^^      ' 

Th?di^pn°  l^^'pfTf  ir  ^^^  JT"'^  '^  \^  ""^P^"  '■  fi^'  ^3,  is  a  horizontal  view  of  it 
of  thP^?:  T  •  f 'P^^l^^termme  the  general  form  of  the  furnace,  and  thickness 
of  the  grate.    To  give  strength  and  solidity  to  the  grate,  it  is  encircled  by  i  bar  or  hoop  of 


ASSAY. 


•r 


iron.  There  is  a  groove  in  which  the  hoop  of  iron  is  fixed.  The  holes  of  the  grate  are 
truncated  cones,  having  the  greater  base  below,  that  the  ashes  may  more  easily  fall  in- 
to the  ash-{)it.  The  letter  v, /</.  81,  shows  the  form  of  these  holes.  The  grate  is  sup- 
ported by  a  small  bank  or  shelfi  making  part  of  the  furnace,  as  seen  at  a,  fig.  81. 

The  nsh-pit,  c,  has  an  opening  y  in  ivonX,fig.  81 ;  and  is  shut  when  necessary  by  the 
mouth-piece,  r,figs.  80  and  81. 

To  give  strength  and  solidity  to  the  furnace,  it  is  bound  with  hoops  of  iron,  at  b,  6, 
b,  b,  fig.  80. 

Figs.  84,  85,  86,  arc  views  of  the  muffle. 

Fig.  87,  is  a  view  of  a  crucible  for  annealing  gold. 

Figs.  88,  89,  90,  are  cupels  of  various  sizes,  to  be  used  in  the  furnace.  They  are  the 
same  as  those  used  by  assayers  in  their  ordinary  furnaces. 

Figs.  91  and  92  are  views  of  the  hand-shovels,  used  for  filling  the  furnace  with 
charcoal ;  they  should  be  made  of  such  size  and  form  as  to  fit  the  opening  h,  in  fUi». 
80  and  81.  F        8    .      y*y 

The  smaller  pincers  or  tongs,  by  which  the  assays  are  charged  into  the  cupels,  and  by 
which  the  latter  are  withdrawn  from  the  furnace,  as  well  as  the  teaser  for  cleaning  the 
grate  of  the  furnace,  are  similar  to  those  used  in  the  British  Mint. 

In  the  furnace  of  the  Mint  above  described,  the  number  of  assays  that  can  be  made  at 
une  time  is  45.  The  same  number  of  cupels  are  put  into  the  muffle.  The  furnace  i? 
then  filled  with  charcoal  to  the  top,  and  upon  this  are  laid  a  few  pieces  already  ignited. 
In  the  course  of  three  hours,  a  little  more  or  less,  according  to  circumstances,  the  whole 
IS  ignited ;  during  which  period,  the  muffle,  which  is  made  of  fire-clay,  is  gradually 
heated  to  redness,  and  is  prevented  from  cracking ;  which  a  less  regular  or  more  sudden 
mcrease  of  temperature  would  not  fail  to  do  :  the  cupels,  also,  become  properly  anneal- 
ed. All  moisture  being  dispelled,  they  are  in  a  fit  stale  to  receive  the  piece  of  silver  or 
gold  to  be  assayed. 

The  greater  care  that  is  exercised  in  this  operation,  the  less  liable  is  the  assayer  to  ac- 
.  cidents  from  the  breaking  of  the  muffle ;  which  is  both  expensive  and  troublesome  to  fit 
properly  into  the  furnace. 

The  cupels  used  in  the  assay  process,  are  made  of  the  ashes  of  burnt  bones  (phosphate 
of  lime).  In  the  Royal  Mint,  the  cores  of  ox-horn  are  selected  for  this  purpose ;  and  the 
aashes  produced  are  about  four  tiroes  the  expense  of  the  bone-ash,  used  in  the  process  ol 
cupellation  upon  a  large  scale.  So  much  depends  upon  the  accuracy  of  an  assay  oC 
gold  or  silver,  where  a  mass  of  151bs.  troy  in  the  first,  and  60lbs  troy  in  the  second 
instance  is  determined  by  the  analysis  of  a  portion  not  exceeding  20  troy  grains,  that 
every  precaution  which  the  longest  experience  has  suggested,  is  used  to  obtain  an  accu- 
rate result.  Hence  the  attention  paid  to  the  selection  of  the  most  proper  materials  for 
making  the  cupels. 

The  cupels  are  formed  in  a  circular  mould  made  of  cast  steel,  very  nicely  turned,  by 
which  means  they  are  easily  freed  from  the  mould  when  struck.  The  bone-ash  is  used 
moistened  with  a  quantity  of  winter,  sufficient  to  make  the  particles  adhere  firmly  togeth- 
er. The  circular  mould  is  filled,  and  pressed  level  with  its  surface  ;  after  which,' a  pestle 
or  rammer,  having  its  end  nicely  turned,  of  a  globular  or  convex  shape,  and  of  a  size 
equal  to  the  degree  of  concavity  wished  to  be  made  in  the  cupel  for  the  reception  of  the 
assay,  is  placed  upon  the  ashes  in  the  mould,  and  struck  with  a  hammer  until  the  cupel 
is  properly  formed.  These  cupels  are  allowed  to  dry  in  the  air  for  some  time  before  they 
are  used.     If  the  m  eather  is  fine,  a  fortnight  will  be  sufficient. 

An  assay  may  prove  defective  for  several  reasons.  Sometimes  the  bittton  or  bead 
sends  forlli  crystalline  vegetations  on  its  surface  with  such  force,  as  to  make  one  suppose 
a  portion  of  the  silver  may  be  thrown  out  of  the  cupel.  When  the  surface  of  the  bead 
is  dull  and  flat,  the  assay  is  considered  to  have  been  too  hot,  and  it  indicates  a  loss  of 
silver  in  fumes.  When  the  tint  of  the  bead  is  not  uniform,  when  its  inferior  surface  is 
bubbly,  when  yellow  scales  of  oxyde  of  lead  remain  on  the  bottom  of  the  cupel,  and 
the  bead  adheies  strongly  to  it,  by  these  signs  it  is  judged  that  the  assay  has  been  too  cold, 
and  that  the  silver  retains  some  lead. 

Lastly,  the  assay  is  thought  to  be  good  if  the  bead  is  of  a  round  form,  if  its  upper  sur- 
face  IS  brilliant,  if  its  lower  surff><;e  is  granular  and  of  a  dead  white,  and  if  it  separates 
readily  from  the  cupel. 

After  the  lead  is  put  into  the  cupel,  it  gets  immediately  covered  with  a  coat  of  oxyde, 
which  resists  the  admission  of  the  silver  to  be  assayed  into  the  melted  metal ;  so  that  the 
alloy  cannot  form.  When  a  bit  of  silver  is  laid  on  a  lead  bath  in  this  predicament,  we 
see  it  swim  about  for  a  long  time  without  dissolving.  In  order  to  avoid  this  result,  the 
silver  is  wrapped  up  in  a  bit  of  paper ;  and  the  carbureted  hydrogen  generated  by  its 
combustion  reduces  the  film  of  the  lead  oxyde,  gives  the  bath  immediately  a  bright  me- 
tallic lustre,  and  enables  the  two  metals  readily  to  combine. 
As  the  heat  rises,  the  oxyde  of  lead  flows  round  about  over  the  surface,  till  it  is  ab- 


J 


TT 


li 


98 


ASSAY. 


sorbed  by  the  cupel.  When  the  lead  is  wasted  to  a  certain  desrree,  a  very  thin  film  of  it 
only  remains  on  the  silver,  which  causes  the  iridiscent  appearance,  like  the  colors  of 
goap-bubbles ;  a  phenomenon,  called  by  the  old  chemists,  fulguration. 

When  the  cupel  cools  in  the  progress  of  the  assay,  the  oxygenation  of  the  lead  ceases; 
and,  instead  of  a  very  liquid  vitreous  oxyde,  an  imperfectly  melted  oxyde  is  formed,  which 
the  cupel  cannot  absorb.  To  correct  a  cold  assay,  the  temperature  of  the  furnace  ou'^ht 
to  be  raised,  and  pieces  of  paper  ought  to  be  put  into  the  cupel,  till  the  oxyde  of  lead 
which  adheres  to  it  be  reduced.  On  keeping  up  the  heat,  the  assay  will  resume  its  ordi- 
nary train. 

Pure  silver  almost  always  vegetates.  Some  traces  of  copper  destroy  this  property, 
which  is  obviously  due  to  the  oxygen  which  the  silver  can  absorb  while  it  is  in  fusion^ 
and  which  is  disengaged  the  moment  it  solidifies.  An  excess  of  lead,  by  removing  all  the 
copper  at  an  early  stage,  tends  to  cause  the  vegetation. 

The  brightening  is  caused  by  the  heat  evolved,  when  the  buttoa  passes  from  the  liquid 
to  the  solid  state.    Many  other  substances  present  the  same  phenomenon. 

In  the  above  operation  it  is  necessary  to  employ  lead  which  is  very  pure,  or  at  least  free 
from  silver.    That  kind  is  called  poor  lead. 

It  has  been  observed  at  all  times,  that  the  oxyde  of  lead  carries  oiT  with  it,  into  the  cu- 
pel, a  little  silver  in  the  state  of  an  oxyde.  This  effect  becomes  less,  or  even  disappears, 
when  there  is  some  copper  remaining ;  and  the  more  copper,  the  less  chance  there  is  of 
any  silver  being  lost.  The  loss  of  silver  increases,  on  the  other  hand,  with  the  dose  of 
lead.  Hence  the  reason  why  it  is  so  important  to  proportion  the  lead  with  a  precision 
which,  at  first  sight,  would  appear  to  be  superfluous.  Hence,  also,  the  reason  of  the  at- 
tempts which  have,  of  late  years,  been  made  to  change  the  whole  system  of  silver  assays, 
and  to  have  recourse  to  a  method  exempt  from  the  above  causes  of  error. 

M.  d'Arcet,  charged  by  the  Commission  of  the  Mint  in  Paris,  to  examine  into  the  jus- 
tice of  the  reclamations  made  by  the  French  silversmiths  against  the  public  assays,  as- 
certained that  they  were  well  founded;  and  that  the  results  of  cupellation  gave  for  the 
alloys  bet  wen  897  and  903  thousandths  (the  limits  of  their  standard  coin)  an  inferior  . 
standard,  by  from  4  to  5  thousandth  parts,  from  the  standard  or  title  which  should  result 
from  the  absolute  or  actual  alloy. 

The  mode  of  assay  shows,  in  fact,  that  an  ingot,  experimentally  composed  of  900 
thousandths  of  fine  silver,  and  100  thousandths  of  copper,  appears,  by  cupellation,  to  be 
only,  at  the  utmost,  896  or  897  thousandths;  whereas  fine  silver,  of  1000  thousa'ndths, 
comes  out  nearly  of  its  real  standard.  Consequently  a  director  of  the  Mint,  who  should 
compound  his  alloy  with  fine  silver,  would  be  obliged  to  employ  903  or  904  thousandths, 
in  order  that,  by  the  assay  in  the  laboratory  of  the  Mint,  it  should  appear  to  have  the 
standard  of  900  thousandths.  These  3  or  4  thousandths  would  be  lost  to  him,  since  they 
would  be  disguised  by  the  mode  of  assay,  the  definitive  criterion  of  the  quantity  of  silver, 
of  which  the  government  keeps  count  from  the  coiner  of  the  money. 

From  the  experiments  subsequently  made  by  M.  d'Arcet,  it  appears  that  silver  assays 
always  suffer  a  loss  of  the  precious  metal,  which  varies,  however,  with  the  standard  of 
the  alloy.    It  is  1  thousandth  for  fine  silver, 

4*3  thousandths  for  silver  of  900  thousandths, 
4-9         —         for    —    of  800        — 
4-2         —  for    —    of  500        — 

and  diminishes  thereafter,  progressively,  till  the  alloy  contains  only  100  thpusandths  of 
silver,  at  which  point  the  loss  is  only  0'4. 

Assays  requested  by  the  Commission  of  the  Paris  Mint,  from  the  assayers  of  the  prin- 
cipal Royal  Mints  in  Europe,  to  which  the  same  alloys,  synthetically  compounded,  were 
sent,  afforded  the  results  inscribed  in  the  following  table. 


Names  of  the  Assayers. 


F.  de  Castenhole,  Mint  Assayer 
A.  R.  Vervaez,           ditto 
D.   M.    Cabrera,    Assayer    in 
Spain  -        -        -        -        - 
Assayer  -        -        -        -        - 
Mr.  Bingley,  Assay  Master 
Mr.  Johnson,  Assayer     - 
Inspector  of  the  Mint 
Assayer  of  the  Mint 
Assayer  of  Trade    -         -         - 
Assayer  of  the  Mint 
Ditto 


Cities  where  they 
reside. 


Vienna 
Madrid 

Ditto 

Amsterdam 

London 

Ditto 

Utrecht 

Naples 

Ditto 

Hamburgh 

Altona 


Standards  found  for  the  Mathematical  Alloys^ 

950  mill. 

900  mill. 

800  mill. 

946-20 

898  40 

795- 10 

944-40 

893-70 

789-20 

944-40 

893-70 

788-60 

94700 

895-00 

795-00 

946-25 

896-25 

794-25 

933-33 

883-50 

783-33 

945-00 

896-50 

799-00 

945-00 

891-00 

787-00 

945-00 

891-00 

787-00 

946'U 

897-^  J 

798-44 

942- i 

894-00 

790 

ASSAY. 


99 


n^ese  results,  as  wel  as  those  in  still  greater  numbers,  obtained  from  the  ablest 
Parisian  assayers,  upon  identical  alloys  of  silver  and  copper,  prove  that  lue  mode  of 
assay  applied  to  them  brings  out  the  standard  too  low ;  and  further,  that  the  quantity 
of  silver  masked  or  disguised,  is  not  uniform  for  these  different  eminent  assay  masters. 
An  alloy,  for  example,  at  the  standard  of  900  thousandths  is  judged  at 

M. 

the  Mint  of  Paris  to  have  a  standard  of  895-6 

At  that  of  Vienna  —  898-4 

—         Madrid  —  893-7 

^         Naples  —  891-0 

The  fact  thus  so  clearly  made  out  of  a  loss  in  the  standard  of  silver  bullion  and  coin, 
merits  the  most  serious  attention  ;  and  it  will  appear  astonishing,  perhaps,  that  a  thing 
r«:arring  every  day,  should  have  remained  for  so  long  a  time  in  the  dark.  In  reality, 
however,  the  fact  is  not  new;  as  the  very  numerous  and  well-made  experiments  of 
Tillet,  from  1760  to  1763,  which  are  related  in  the  memoirs  of  the  Academy  of 
Sciences,  show,  in  the  silver  assays,  a  loss  still  greater  than  that  which  was  experienced 
lately  in  the  laboratory  of  the  Commission  of  the  French  Mint.  But  he  thought  that, 
as  the  error  was  common  to  the  nations  in  general,  it  was  not  worth  while  or  prudent 
to  introduce  any  innovation. 

A  mode  of  assaying,  to  give,  with  certainty,  the  standard  ci*  silver  bullion,  should  be 
entirely  independent  of  the  variable  circumstances  of  temperature,  and  the  unknown 
proportions  of  copper,  so  difficult  to  regulate  by  the  mere  judgment  of  the  senses.  The 
process  by  the  humid  way,  recommended  by  me  to  the  Royal  Mint  in  1829,  and  ex- 
hibited as  to  its  principles  before  the  Right  Honorable  John  Herries,  then  Master,  in 
1830,  has  all  the  precision  and  certainty  we  could  wish.  It  is  founded  on  the  well-known 
property  which  silver  has,  when  dissolved  in  nitric  acid,  to  be  precipitated  in  a  chloride  of 
silver  quite  insoluble,  by  a  solution  of  sea  salt,  or  by  muriatic  acid  ;  but,  instead  of  deter- 
mining the  weight  of  the  chloride  of  silver,  which  would  be  somewhat  uncertain  and 
rather  tedious,  on  account  of  the  difficulty  of  dr}ing  it,  we  take  the  quantity  of  the 
solution  of  sea  salt  which  has  been  necessary  for  the  precipitation  of  the  silver.  To 
put  the  process  in  execution,  a  liquor  is  prepared,  composed  of  water  and  sea  salt  in  such 
proportions  that  1000  measures  of  this  liquor  may  precipitate,  completely,  12  grains  of 
silver,  perfectly  pure,  or  of  the  standard  1000,  previously  dissolved  in  nitric  acid.  The 
liquor  thus  prepared,  gives,  immediately,  the  true  standard  of  any  alloy  whatever,  of 
silver  and  copper,  by  the  weight  of  it  which  may  be  necessary  to  precipitate  12  grains 
of  this  alloy  If,  for  example,  905  measures  have  been  required  to  precipitate  the  12 
grains  of  alloy,  its  standard  would  be  905  thousandths. 

The  process  by  the  humid  way  is,  so  to  speak,  independent  of  the  operator.  The 
manipulations  are  so  easy ;  and  the  term  of  the  operation  is  very  distinctly  announced  by 
the  absence  of  any  sensible  nebulosities  on  the  affusion  of  sea  salt  into  the  silver  solution, 
while  there  remains  in  it  ^  thousandth  of  metal.  The  process  is  not  tedious,  and  in 
experienced  hands  it  may  rival  the  cupel  in  rapidity ;  it  has  the  advantage  over  the 
cupel  of  being  more  within  the  reach  of  ordinary  operators,  and  of  not  requiring  a  long 
apprenticeship.  It  is  particularly  useful  to  such  assayers  as  have  only  a  few  assays  to 
make  daily,  as  it  will  cost  them  very  little  time  and  expense. 

By  agitating  briskly  during  two  minutes,  or  thereby,  the  liquid  rendered  milky  by 
the  precipitation  of  the  chloride  of  silver,  it  may  be  sufficiently  clarified  to  enable  us  to 
appreciate,  after  a  few  moments  of  repose,  the  disturbance  that  can  be  produced  in  it  by 
the  addition  of  1000  of  a  gram  of  silver.  Filtration  is  more  efficacious  than  agitation, 
especially  when  it  is  employed  afterwards;  it  may  be  sometimes  used;  but  agitation, 
which  is  much  more  prompt,  is  generally  sufficient.  The  presence  of  lead  and  copper, 
or  any  other  melal,  except  mercury,  has  n  perceptible  influence  on  the  quantity  of  sea 
salt  necessar)'  to  precipitate  the  silver ;  that  is  to  say,  the  same  quantity  of  silver,  pure 
or  alloyed,  requires  for  its  precipitation  a  constant  quantity  of  the  solution  of  sea  ssJt. 

Supposing  that  we  operate  upon  a  gramme  of  pure  silver,  the  solution  of  sea  salt 
ought  to  be  such  that  100  centimetres  cube  may  precipitate  exactly  the  whole  silver. 
The  standard  of  an  alloy  is  given  by  the  number  of  thousandths  of  solution  of  sea  salt 
necessary  to  precipitate  the  silver  contained  in  a  gramme  of  the  alloy. 

When  any  mercury  is  accidentally  present,  which  is,  however,  a  rare  occurrence,  it 
is  made  obvious  by  the  precipitated  chloride  remaining  white  when  exposed  to  daylight, 
whereas  when  there  is  no  mercury  present,  it  becomes  speedily  first  gray  and  then 
purple.  Silver  so  contaminated  must  be  strongly  ignited  in  fusion  before  being  assayed, 
and  its  loss  of  weight  noted.    In  this  case,  a  cupel  assay  must  be  had  recourse  to. 

Preparation  of  the  Normal  SohUioii  of  Sea  Salt,  when  it  is  measured  by  Weight. — Sup- 
posing the  sea  salt  pure  as  well  as  the  water,  we  have  only  to  take  these  two  bodies  in 
the  proportion  of  0-5427  k.  of  salt  to  99-4573  k.  of  water,  to  have  100  k.  of  solution. 


i 


fa 


V  ^ 


: 


t,- 


100 


ASSAY. 


kep.  i„  reserve  fofS^f^fi  t  ^^tj^  ''il'.Zt^lTay'li:^'^  ""  «  •^».  «»  ^ 

the  san.e  -egree'tf  ^ect^n-^rrial^eM^P^^^^^  "^  ""^^ 

The  measure   by  volume  has  nnt  nil   ..      '      ,       .  ^  ^'^  "^^"  of  no  correct  on. 

precision,  it  is  more  rTpL,  and  Tque  s^^^^^^^^  ^"^'   ^^  §™=  ''  '''^''^^^' 

mm.  This  normal  solution  is  ^  made  S  a  v^umn  T™''^  ^^^l  assays  of  the 
of  water,  or  100  centimetres  cube  aTa  dete^inntl  ^"^"^^  ^^  *^'^^  °^  ^^^  grammes 

one  gmmme  of  silver.  The  solution  nSv^  k?nf  ^T^'''^'"""'  "^^^  precipitate  exactly 
this  case  the  assay  stands  in  wat  orno  cLrectlT  <^r  VhJ?^  temperature,  and  ii 
the  assay  must  be  corrected  accordin<^  to  itsTnfluence  Th  ^"^P^J^t^^e  be  variable, 
no  change  in  the  principle  of  the  nrocess  hni  th!!  ^^^^  ^'^^  circumstances  make 

some  modifications  in  the  apparatus      Exd^^^^^  h^!  '^^^^'^  i^P^^tant  to  occasion 

of  applying  a  correction  to  l7arMe  temSu  e  '''  "^'"'^'^  ^^^  ^^^^-^^^  -  ^-'or 
We  readily  obtain  a  volume  of  lOO  cu^bic  centimetres  by  means  of  a,.>/.,  ^,  93 

~*  ""^ !?  T^l  '^"i  ^^^"  fi"^^  ^-'^^  w^afer  up  to  the 

mark  a,  &,  and  well  dried  at  its  point,  it  wiU  ru^ 

at  tC  t:r"'^r'"%^®"^'  ^^  ?^^es  of  wa^ 
at  the  temperature  of  15  C.  (59  Fah.).     We  sav 

'Ma  Jr     Ik  ^"^J^*'  *^e   pipette  may  still  furnish  two  or 

f]£      aU6     i^/;j,^-Psofliquid  which  must  not  be  c^^^^ 

^       ^k       or  reckoned  upon.     The  weight  of  the  volume  of 

he  normal  solution,  taken  in   this  manner  ^^^^ 

suitable   precautions,  will  be  uniform  from  one 

ha  fTt'^o  T'\'''  "P°"  ^^«  centio^etres  and  a 
hi  Hiff  '  '  *";  ^^  ^  ^"^'■*^''  c^  a  thousandth,  and 
he  difference  from  the   n.cun   will  be  obviously 

twice  less,  or  one  half.    Let  us  indicate  theS 

siroTsTa^:^;:^^^  ^  -^--  «^  ^^^  -^ 

,•„  l^'^""  ¥''?''^  immersed  the  beak  c  of  the  pipette 
m  the  solution  we  apply  suction  by  the  Si' 
to  the  upper  orifice,  and  thereby  raise  the  liquW  to 
d,  above  the  circular  line  a  b.  We  nex  aDn  r 
neatly  the  forefinger  of  one  hand  to  th?s  or'fic/ 
remove  the  pipette  from  the  liquid,  and  iiie  It 

llrT^'Ti  ^^.•^^•9^-    The'mark  aTbeL. 
placed  at  the  evel  of  the  eye,  we  make  the  sur- 

the  plane  a  b.  At  the  instant  it  becomes  a  ^an^enrw'T  ^^^^1"'?"^'^  ^  ^^"5^"*  to 
open,  by  taking  away  the  fin.'er  th^t  h«rl  hp!n  '  "^f.^S^^^  ^}'^  beak  c  of  the  pipette 
anything  else  in  the  position  of  the  hL^«        ^"  ?P^'.^^.  ^°  "'  ^^^  ^^^thout  changing 

receive  the  solution,  tEg  care  to  remov^^^^^  V'V^^  ^"^«  ^^'^h  shSuld 

If,  after  filling  the  pipeiFe  bv  suctfoTon     '^^^'?^^"  the  efflux  has  run  out. 
forefinger  fast  enough  to  the  UDDer'n^         ^"^  «^°"^^  ^"^  a  difficulty  in  applying  the 
the  mark   a  b,  he  should    eLTe'  the  pf^^^^^^^  ''K'^  ^^  ^own  below 

with  his  tongue,  then  apply  the  middirfinirT^^^  T^ '^'  ^°P  ^ti"  closed 

after  which  he  may  withdraw  hiTtnnll    ^  a         1"^  f  ^'^  ^*"^s  to  the  lower  orifice  • 

the  orifice  previous^wiped      Thirrfod^  o?  ob'tl^  *''  ^"'^"^^^  °^  ^^^  ^^^^^  ^--^^o  ' 
sea  salt  is  very  sitrple,  and  requires  S,  comnlex  Inn    ^^  '"l^'"'^  ^^  "™^^  ««J"tion  of 
manipulation  still  easier,  and^so  Lore  e^iet     ^^^^'^^"^  '-  ^^'^^  ^haU  indicate  another 

filleVb'y^uXraTdVttS^^  ^^p  like  a  bottle,  instead  of  bein. 

D'are   two  sockets  separated  by  a  stotco^V    Th'/l^  "'P'''^"^'-    ^  «"^ 

receives,  by  means  of  a  cork  stopper  l  the  tuhp  V  tl-  ^^^7  .''"^'  ^^PP^'^  interiorly, 
salt.  The  lower  socket  is  cemen?e7on^othrw/;^''K  *^"'''  *^^  ^^^^^ion  of  sea 
a  screw  plug  v,  which  regulates  a  iTnute  opeS "'fy^tin  ^T^  V^^b  ^'''''^^  ^^  «°^ 
slowly  into  the  pipettv.  Below  the  s^on-cock  ^5  ^^"'^^^  ^o  let  the  air  enter  verv 
soldered  to  the  socket,  leads  the  soLttn  fnto  the  Iw  IfV°^,^'  ?^  "^''^^^  diameter, 
displaces,  to  escape  by  the  stopcock  K'TheJrfl'^  ^^  *^  r^"^  ^^^  ^^*  ^^i^h  U 
replaces  the  ordin^  screw  b- whLh  the^pvnf  tK.^^^^^  ^'»^  '^^^^   head  V, 

with  more  or  less  force,  upon Vcontal  ^at  ^       ^^^  '^'^-'^^  "^^^  *>«  ^^^  to  pres. 


1 


ASSAY. 


101 


Fig.  96  represents,  in  a  side  view,  the  apparatus  just  described.    We  here  remark  an 

air-cock  r,  and  an  opening  m.    At  the  extremity  Q  of  the  same  figure,  the  conical  pipe 

T  enters,  with  friction.    It  is  by  this  pipe  that  the  air  is  sucked  into  the  pipette  when  it 

is  to  be  filled  from  its  beak.  ^        -v  .i       v 

The  pipette  is  supported  by  two  horizontal  arms  h  k  (fig.  97)  moveable   about  a 

common  axis  a  a,  and  capable  of  being  drawn 
out  or  shortened  by  the  aid  of  two  longitu- 
dinal slits.  They  are  fixed  steadily  by  two 
screw  nuts  e  e,  and  their  distance  may  be  varied 
by  means  of  round  bits  of  wood  or  cork  inter- 
posed, or  even  by  opposite  screw  nuts  o  6.  The 
upper  arm  h  is  pierced  with  a  hole,  in  which 
is  fixed,  by  the  pressure  of  a  wooden  screw  r, 
the  socket  of  the  pipette.  The  corresponding 
hole  of  the  lower  arm  is  larger ;  and  the  beak 
of  the  pipette  is  supported  in  it  by  a  cork  stop- 
per L.  The  apparatus  is  fixed  by  its  tail-piece 
p,  by  means  of  a  screw,  to  the  corner  of  a  wall, 
or  any  other  prop. 

The  manner  of  filling  the  pipette  is  very  sim- 
ple. We  begin  by  applying  the  fore-finger  of 
the  left  hand  to  the  lower  aperture  c ;  we  then 
open  the  two  stop-cocks  r  and  r'.  Whenever 
the  liquor  approaches  the  neck  of  the  pipette,  we 
must  temper  its  influx,  and  when  it  has  arrived 
at  some  millimetres  above  the  mark  a  6,  we  close 
the  two  stop-cocks,  and  remove  our  fore-finger. 
We  have  now  nothing  more  to  do  than  to  regu- 
late the  pipette;  for  which  purpose  the  liquid 
must  touch  the  line  a  b,  and  must  simply  adhere 
externally  to  the  beak  of  the  pipette. 
This  last  circumstance  is  easUy  adjusted. 
After  taking  away  the  finger  which  closed  the  aperture  c  of  the  pipette,  we  apply  to  this 
orifice  a  moist  sponge  m,fig.  88,  wrapped  up  in  a  linen  rag,  to  absorb  the  superfluous 

liquor  as  it  drops  out.  This  sponge 
is  called  the  handkerchief  (mott- 
choir),  by  M.  Gay  Lussac.  The 
pipette  is  said  to  be  wiped  when 
there  is  no  liquor  adhering  to  its 
point  exteriorly. 

For  the  convenience  of  operat- 
ing, the  handkerchief  is  fixed  by 
friction  in  a  tube  of  tin  plate,  ter- 
minated by  a  cup,  open  at  bottom 
to  let  the  droppings  flow  off  into 
the  cistern  c,  to  which  the  tube  is 
soldered.  It  may  be  easily  re- 
moved for  the  purpose  of  washing 
it ;  and,  if  necessary,  a  little  wedge 
of  wood,  0,  can  raise  it  toward  the  pipette. 

To  complete  the  adjustment  of  the  pipette,  the  liquid  must  be  made  merely  to  descend 
to  the  mark  a,  b.  With  this  view,  and  while  the  handkerchief  is  applied  to  the  beak 
o  the  pipette,  the  air  must  be  allowed  to  enter  very  slowly  by  unscrewing  the  plug  v, 
fig.  95;  and  at  the  moment  of  the  contact  the  handkerchief  must  be  removed,  and  the 
bottle  r,  destined  to  receive  the  solution,  must  be  placed  below  the  orifice  of  the  pipette, 
fig.  98.  As  the  motion  must  be  made  rapidly,  and  without  hesitation,  the  bottle  is 
placed  .n  a  cylinder  of  tin-plate,  of  a  diameter  somewhat  greater,  and  forming  one  body 
with  the  cistern  and  the  handkerchief.  The  whole  of  this  apparatus  has  for  a  basis  a 
plate  of  tinned  iron,  moveable  between  two  wooden  rulers  r  r,  one  of  which  bears  a 
groove,  under  which  the  edge  of  the  plate  slips.  Its  traverses  are  fixed  by  two  abutments 
b  b,  placed  so  that  when  it  is  stopped  by  one  of  them,  the  beak  of  the  pipette  corresponds 
to  the  centre  of  the  neck  of  the  bottle,  or  is  a  tangent  to  the  handkerchief.  This 
arrangement,  very  convenient  for  wiping  the  pipette  and  emptying  it,  gives  the  apparatus 
sufficient  solidity,  and  allows  of  its  being  taken  away  and  replaced  without  deranging 
anything.  It  is  obvious  that  it  is  of  advantage,  when  once  the  entry  of  the  air  into 
the  pipette  has  been  regulated  by  the  screw  v,  to  leave  it  constantly  open,  because  the 


I,  ' 


102 


ASSAY. 


I 


1 

I 


motion  frora  the  handterchief  to  the  bottle  is  performed  with  sufficient  rapidity  to  prevent 
a  drop  of  the  solution  from  collecting  and  falling  down. 

Temperature  of  the  Solution. — After  having  described  the  manner  of  measuring  by 
vcflume  the  normal  solution  of  the  sea  salt,  we  shall  indicate  the  most  conv(;nient  means 
of  taking  the  temperature.  The  thermometer  is  placed  in  a  tube  of  glass  t,  Jig.  89, 
which  the  solution  traverses  to  arrive  at  the  pipette.  It  is  suspended  in  it  by  a  piece  of 
cork,  grooved  on  the  four  sides  to  afford  passage  to  the  liquid.  The  scale  is  engraved 
upon  the  tube  itself,  and  is  repeated  at  the  opposite  side,  to  fix  the  eye  by  the  coincidence 
of  this  double  division  at  the  level  of  the  thermometric  column.  The  tube  is  joined 
below  to  another  narrower  one,  through  which  it  is  attached  by,means  of  a  cork  stopper 
B,  in  the  socket  of  the  stop-cock  of  the  pipette.  At  its  upper  part  it  is  cemented  into  a 
brass  socket,  screw-tapped  in  the  inside,  which  is  connected  in  its  turn  by  a  cock,  with 
the  extremity,  also  tapped,  of  the  tube  above  t,  belonging  to  the  reservoir  of  the  normal 
solution.  The  corks  employed  here  as  connecting  links  between  the  parts  of  the 
apparatus,  give  them  a  certain  flexibility,  and  allow  of  their  being  dismounted  and  re- 
mounted in  a  very  short  time ;  but  it  is  indispensable  to  make  them  be  traversed  by  a 
hollow  tube  of  glass  or  metal,  which  will  hinder  them  from  being  crushed  by  the  pressure 
they  are  exposed  to.  If  the  precaution  be  taken  to  grease  them  with  a  little  suet,  and  to 
fill  their  pores,  they  will  suffer  nO  leakage. 

Preservation  of  the  Normal  Solution  of  Sea  Salt  in  metallic  Vessels. — M.  Gay  Lussac 
uses  for  this  purpose  a  cylindrical  vessel  or  drum  of  copper,  of  a  capacity  of  about  1 10 
litres,  having  its  inside  covered  with  a  rosin  and  wax  cement. 

Preparation  of  the  Normal  Solution  of  Sea  Salt,  measuring  it  by  Volume. — If  the  drum 
contains  1 10  litres,  we  should  put  only  105  into  it,  in  order  that  sufficient  space  may  be 
left  for  agitating  the  liquor  without  throwing  it  out.  According  to  the  principle  that 
100  centimetres  cube,  or  JL  of  a  litre  of  the  solution  should  contain  enough  of  sea  salt  to 
precipitate  a  gramme  of  pure  silver ;  and,  admitting,  moreover,  13*516  for  the  prime  equi- 
valent of  silver,  and  7*335  for  that  of  sea  salt,  we  shall  find  the  quantity  of  pure  salt  that 
should  be  dissolved  in  the  105  litres  of  water,  and  which  corresponds  to  105  X  10  =  1050 
grammes  of  silver,  to  be  by  the  following  proportion : — 

13*516  :  7-335  :*.  1050  gramra.  :  x=569-83  gr. 

And  as  the  solution  of  the  sea  salt  of  commerce,  formerly  mentioned,  contains  approxi- 
mately 250  grammes  per  kilogramme,  we  must  take  2279*3  grammes  of  this  solution  to 
have  569*83  gram,  of  sail.  The  mixture  being  perfectly  made,  the  tubes  and  the  pipeti* 
must  be  several  times  washed  by  running  the  solution  through  them,  and  putting  it  into 
the  drum.  The  standard  of  the  solution  must  be  determined  after  it  has  been  well  agi- 
tated, supposing  the  temperature  to  remain  uniform. 

To  arrive  more  conveniently  at  this  result,  we  begin  by  preparing  two  decimes  solu- 
tions ;  one  of  silver,  and  another  of  sea  salt. 

The  decime  solution  of  silver  is  obtained  by  dissolving  1  gramme  of  silver  in  nitric  acid, 
and  diluting  the  solution  with  water  till  its  volume  becomes  a  litre. 

The  decime  solution  of  sea  salt  may  be  obtained  by  dissolving  0*543  grammes  of  pure 
sea  salt  in  water,  so  that  the  solution  shall  occupy  a  litre ;  but  we  shall  prepare  it  even 
with  the  normal  solution  which  we  wish  to  test,  by  mixing  a  measure  of  it  with  9  mea- 
sures of  water  ;  it  being  understood  that  this  solution  is  not  rigorously  equivalent  to  that 
of  silver,  and  that  it  will  become  so,  only  when  the  normal  solution  employed  for  its  pre- 
paration shall  be  finally  of  the  true  standard.  Lastly,  we  prepare  beforehand  several 
stoppered  vials,  in  each  of  which  we  dissolve  1  gramme  of  silver  in  8  or  10  grammes  of 
nitric  acid.    For  brevity's  sake  we  shall  call  these  tests. 

Now  to  investigate  the  standard  of  the  normal  solution,  we  must  transfer  a  pipette  of 
it  into  one  of  these  test  vials  ;  and  we  must  agitate  the  liquors  briskly  to  clarify  them. 
After  some  instants  of  repose,  we  must  pour  in  2  thousandths  of  the  decime  solution  ol 
sea  salt,  which,  we  suppose,  will  produce  a  precipitate.  The  normal  liquor  is  conse- 
quently too  feeble ;  and  we  should  expect  this,  since  the  sea  salt  employed  was  not  per- 
fectly pure.  We  agitate  and  add  2  fresh  thousandths,  which  will  also  produce  a  precipi- 
tate. We  continue  thus  by  successive  additions  of  2  thousandths,  till  the  last  produces 
no  precipitation.  Suppose  that  we  have  added  16  thousandths  :  the  last  two  should  not 
be  reckoned,  as  they  produced  no  precipitate ;  the  preceding  two  were  necessary,  but 
only  in  part ;  that  is  to  say,  the  useful  thousandths  added  are  above  12  and  below  14,  or 
otherwise  they  are  on  an  average  equal  to  13. 

Thus,  in  the  condition  of  the  normal  solution,  we  require  1013  parts  of  it  to  pre- 
cipitate one  gramme  of  silver,  while  we  should  require  only  1000.  We  shall  find  the 
quantity  of  concentrated  solution  of  sea  salt  that  we  should  add,  by  noting  that  the 
quantity  of  solution  of  sea  salt,  at  first  employed,  viz.  2279*3  grammes,  produced  a 
standard  of  only  987  thousandths=1000 — 13;  and  by  using  the  following  proportion: 

987  :  2279*3  ::  13  :  x=30'02  grammes. 


ASSAY. 


108 


This  quantity  of  the  strong  solution  of  salt,  mixed  with  the  norma*  solation  in  the 
dram,  will  correct  its  standard,  and  we  shall  now  see  by  how  much. 

After  having  washed  the  tubes  and  the  pipette  with  the  new  solTition,  we  mtrat 
repeat  the  experiment  upon  a  fres-h  gramme  of  silver.  We  shall  find,  for  example,  in 
proceedinsr  only  by  a  thousandth  at  a  time,  that  the  first  causes  a  precipitate,  but  not  the 
second.  The  standard  of  the  solution  is  still  too  weak,  and  is  comprised  between  1000 
and  1001 ;  that  is  to  say,  it  may  be  equal  to  1000|,  but  we  must  make  a  closer  approxi- 
mation. 

We  pour  into  the  test  bottle  2  thousandths  of  the  decime  solution  of  silver,  which  will 
destroy,  perceptibly,  two  thousandths  of  sea  salt,  and  the  operation  will  have  retrograded 
by  two  thousandths ;  that  is  to  say,  it  will  be  brought  back  to  the  point  at  which  it  was 
first  of  all.  If,  after  having  cleared  up  the  liquor,,  we  add  half  a  thousandth  of  the  de- 
eime  solution,  there  will  necessarily  be  a  precipitate,  as  we  knew  beforehand,  but  a  se- 
cond will  cause  no  turbidity.  The  standard  of  the  normal  liquor  will  be  consequently 
comprehended  between  1000  and  1000|,  or  equal  to  lOOOj. 

We  should  rest  content  with  this  standard,  but  if  we  wish  to  correct  it,  we  may 
remark  that  the  two  quantities  of  solution  of  salt  added,  viz.  2279*3  gr.  -j-  3002  gr.= 
2309*32  gr.  have  produced  only  999*75  thousandths,  and  that  we  must  add  a  new 
quantity  of  it  corresponding  to  ^  of  a  thousandth.    We  make,  therefore,  the  proportion 

999*75  :  2309*32  ::  0*26  :  x. 

But  since  the  first  term  differs  very  little  from  1000,  we  may  content  ourselves  to 
have  X  by  taking  the  \'A^  of  2309*32,  and  we  shall  find  0*577  gr.  for  the  quantity  of 
solution  of  sea  salt  to  be  added  to  the  normal  solution. 

It  is  not  convenient  to  take  exactly  so  small  a  quantity  of  solution  of  sea  salt  by  the 
balance,  but  we  shall  succeed  easily  by  the  following  process.  We  weigh  50  grammes 
of  this  solution,  and  we  dilute  it  with  water ;  so  that  it  occupies  exactly  half  a  litre,  or 
600  centimetres  cube.  A  pipette  of  this  solution,  one  centimetre  cube  in  volume,  will 
give  a  decigramme  of  the  primitive  solution,  and  as  such  a  small  pipette  is  divided  into 
twenty  drops,  each  drop,  for  example,  will  represent  5  milligrammes  of  the  solution.  We 
should  arrive  at  quantities  smaller  still  by  diluting  the  solution  with  a  proper  quantity 
of  water ;  but  greater  precision  would  be  entirely  needless. 

The  testing  of  the  normal  liquor  just  described,  is,  in  reality,  less  tedious  than  might 
be  supposed.  It  deserves  also  to  be  remarked,  that  liquor  has  been  prepared  for  more 
than  1000  assays ;  and  that,  in  preparing  a  fresh  quantity,  we  shall  obtain  directly  its  true 
standard,  or  nearly  so,  if  we  bear  in  mind  the  quantities  of  water  and  solution  of  salt 
which  had  been  employed. 

Correction  of  the  Standard  of  the  Normal  Solution  of  Sea  Salt,  when  the  Temper aturt 
changes. — We  have  supposed,  in  determining  the  standard  of  the  normal  solution  of  sea 
salt,  that  the  temperature  remained  uniform.  The  assays  made  in  such  circumstances, 
have  no  need  of  correction ;  but  if  the  temperature  should  change,  the  same  measure  of 
the  solution  will  not  contain  the  same  quantity  of  sea  salt.  Supposing  that  we  have 
tested  the  solution  of  the  salt  at  the  temperature  of  15°  C. ;  if,  at  the  time  of  making  the 
experiment,  the  temperature  is  18°  C,  for  example,  the  solution  will  be  too  weak  on  ac- 
count of  its  expansion,  and  the  pipette  will  contain  less  of  it  by  weight ;  if,  on  the  con- 
trary, the  temperature  has  fallen  to  12°,  the  solution  will  be  thereby  concentrated  and 
will  prove  too  strong.  It  is  therefore  proper  to  determine  the  correction  necessary  to  be 
made,  for  any  variation  of  temperature. 

To  ascertain  this  point,  the  temperature  of  the  solution  of  sea  salt  was  made  succes- 
sively to  be  a»,  5°,  10°,  15°,  20°,  25°,  and  30°  C. ;  and  three  pipettes  of  the  solution  were 
weighed  exactly  at  each  of  these  temperatures.  The  third  of  these  weighings  gave  the 
mean  Aveight  of  a  pipette.  The  corresponding  weights  Of  a  pipette  of  the  solution,  were 
afterwards  graphically  interpolated  from  degree  to  degree.  These  weights  form  the  se- 
cond column  of  the  following  table,  entitled,  Table  of  Correction  for  the  Variations  in  the 
Temperature  of  the  Normal  Solution  of  the  Sea  Salt.  They  enable  us  to  correct  any  tem- 
perature between  0  and  30  degrees  centigrade  (32P  and  86°  Fahr.)  when  the  solution  of 
sea  «;alt  has  been  prepared  in  the  same  limits. 

Let  us  suppose,  for  example,  that  the  solution  has  been  made  standard  at  15°,  and 
that,  at  the  time  of  using  it,  the  temperature  has  become  18°.  We  see  by  the  second 
column  of  the  table,  that  the  weight  of  a  measure  of  the  solution  is  100*099  gr.  at  15°, 
and  100*065  at  18°;  the  difference  0*034  gr.,  is  the  quantity  of  solution  less  which  has 
been  really  taken ;  and  of  course  we  must  add  it  to  the  normal  measure,  in  order  to 
make  it  equal  to  one  thousand  milliemes.  If  the  temperature  of  the  solution  had  fallen 
to  10  degrees,  the  difference  of  the  weight  of  a  measure  from  10  to  15  degrees  would  be 
0*019  gr.,  which  we  must  on  the  contrary  deduct  from  the  measure,  since  it  had  been  taken 
too  large.    These  differences  of  weight  of  a  measure  of  solution  at  15**,  from  that  of  a 


J 


r     I 


104 


ASSAY. 


measure  at  any  other  temperature,  form  the  column  15°  of  the  table  whprp  th^v  •«. 
expressed  m  thousandths;  they  are  inscribed  on  the  same  horizontal  linT.S  thftem 
peratures  to  which  each  of  them  relates,  with  the  sign  +  plus,  when  hey  must  blL?S' 
and  with  the  sign  _  minus,  when  they  must  be  subtraTte^d.  The  c  lumns  5'  ^V  2^.' 
25  ,  3o°,  have  been  calculated  in  the  same  manner  for  the  cases  in  wh Jrh  th/ nArl  1 
so  uuon  may  have  been  graduated  to  each  of  these  temperatt^es  Thus  to  calLa^^^^^^^ 
column  10,  the  number  100-118  has  been  taken  of  the  column  of  weights  ?or  a  1.^ 

Xt!'''  '"'  '''  ^^^^"'^  '""   ""''  '''  "^^^^«  ''  ^^"  sa^tTuSn  \T^fn 

Table  of  Correction  for  the  Variations  in  iLt  Temperatiire  of  the  Normal  Solution  of 

the  Sea  Salt. 


Temperature. 


4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 


Weight. 


I 


eram. 

100,109 
100,113 
100,115 
110,118 
100,120 
100,120 
100,118 
100,116 
100,114 
100,110 
100,106 
100,099 
100,090 
100,078 
100,065 
100,053 
100,039 
100,021 
100,001 
99,983 
99,964 
99,944 
99,924 
99,902 
99,879 
99,858 
99,836 


mill. 

00 

0-0 

0-0 

4-0-1 

—  0-1 
--01 

—  0-1 
0-0 
0-0 
0-0 

—  0-1 

—  0-1 
--0-2 

—  0-4 

—  0-5 

—  0-6 

—  0-7 

—  0-9 

—  1-1 

—  1-3 

—  1-5 

—  1-7 

—  1-9 

—  2-1 

—  2-3 

—  2-6 

—  2-8 


10° 


mill. 

—  0-1 

—  0-1 
0-0 
0-0 
0-0 
0-0 
0-0 
0-0 
0-0 

—  0-1 

—  0-1 

—  0-2 

—  0-3 

—  0-4 

—  0-5 

—  0-7 

—  0-8 

—  1-0 

—  1-2 

—  1-4 

—  1-5 

—  1-7 

—  1-9 

—  2-2 

—  2-4 

—  2-6 

—  2-8 


15° 


20= 


25° 


t 


mill. 
—  0-1 
--0-1 
--0-2 
--0-2 
--0-2 
--0-2 
--0-2 
--0-2 
--0-2 
0-1 
0-1 

—  0-0 

—  0-1 

—  0-2 

—  0-3 

—  0-5 

—  0-6 

—  0-8 

—  1-0 

—  1-2 

—  1-4 

—  1-6 

—  1-8 

—  2-0 

—  2-2 

—  2-4 

—  2-6 


mill. 
--0-7 
--0-7 
--0-8 
0-8 
-r  0-8 
+  0-8 

—  08 
--0-8 
--0-8 
--0-7 
--0-7 
--0-6 
--0-5 

—  0-4 

—  0-3 

—  0-1 
00 

—  0-2 
-.0-4 

—  0-6 

—  0-8 

—  1-0 

—  1-2 

—  1-4 

—  1-6 

—  1-8 

—  2-0 


mill. 
1-7 
1-7 

—  1-7 
--  1-7 
--1-8 

—  1-8 
--1-7 

—  1-7 


--1- 
—  1- 


7 
7 
1-6 
1-6 
--1-5 

—  1-3 

—  1-2 
--  M 
--10 
--0-8 
--0-6 
--0-4 
-f  0-2 

0-0 

—  0-2 

—  0-4 

—  0-7 

—  0-9 

—  M 


30«» 


mifl. 
-j-2-7 
--2-8 
—  2-8 
--2-8 
--2-8 
--2-8 
--2-8 
--2-8 
2-8 
2-7 
-I-2-7 
--2-6 
--2-5 
--2-4 
2-3 
2-2 
--2-0 
--1-9 
-f  1.7 
-I-1-5 
—  1-3 
--M 
--0-9 
--0-7 
--0-4 
--0-2 
0-0 


the^srolacrtwlu  f   ^,^^"  ^"^P^^^^  *«  facilitate  and  abridge  the  manipulations.  In 
thl  .™  w  ^  I      J  Hi?''  ^^'^'"f.  "'  assaying  the  specimens  of  silver  should  all  be  of 
^^nnZtj     ^""^  •  ^  t^  "^^  ^'^^^'''     They  should  be  numbered  at  their  top,  as  well 
^e  llL  o7r''  '"^  '^^  -'^l'  ^  2'  ?'  ^''    They  may  be  ranged  successively  n  teTs 
lilfE  f  ^    .>f  '^f  ^  'T''  ?"'""  P^^'«^  ^'^  «  «»PP«rt  in  their  proper  order.   Each  two 

ments  dul^C  wV"^^^^^^^  ^^""'^  ^".  "  ^'"^'""^^  ^'^  ^^^^  (•^^^-  ^  ^^)'  ^^'^  ^en  comply? 
SJ.tfi^^u«.These  compartments  are  cut  out  anteriorly  to  about  half  their 
height,  to  a  ow  the  bottoms  of  the  bottles  to  be  seen.    AVhen  each  vial  has  received  iS 

^Im2fn?^lT•'''''•7^^''^^•1^^^^^^  °^"^t  be  poured  into  it  a^St   S 

grammes  of  nitric  acid  of  specific  gravity  1-28,  with  a  pipette,  containing  that  quant  tv- 

illov  ThP^'f  VX'^'""'  t^  ^"^^^  ^^^^'  ^'^  order  to  facilitate  the  LluUon  of  tJ^ 
fi2'  IthJT^  VTZ^^''^^''^''^^  "^^^^  «f  ti"  plate,  intended  to  receive  the 
ve^t^ne  the  viak  h.in?i'  1'"^^'  bottom,  pierced  with  smaU  holes,  for  the  purpose  of  pre- 
lZ\n     tZI^T^  '^'^^"J  ^'  It  msulates  them  from  the  bottom  to  which  Uie  heat  is 

rotetarriId'ruX\"cSneV.^"''  ^""  ''  ^""'^  "^""^  ^^^"  ^^  ^'""'^"^^'  "  ^"»^^^ 
]pn^\'pof /'''r'~^-°^'^^\^'T'  ^  s^ffic'e"t'y  ^^act  idea  of  it,  and  may  dispense  with  a 
Thfvtl!  J'''tT''";\-^'  has  ten  cylindrical  compartmenis,  numbered  from  1  to  lo! 

thP  An  J  f    f^       'I  ^^"  ?'^^^^.  "^^'"^  ^^^^^  «f  the  pipette,  intended  to  measure  put 
Eacrrthlril ''!S  "'^^r/^'V  ^"^  ^  ^P'^^'  *"""  «f  this'^solution  is  put  in  each  v?al 
fir<^? ;    t^    ^}?^^c  Z'^^  '*'  ^'a^,stoPP^'-»  previously  dipped  in  pure  water.     They  are 
fixed  in  the  cells  of  Uie  agitator  by  wooden  wedges.    The  agititor  is  then  susjinded 


> 


ASSAY. 


10& 


to  a  spring  R,  and,  seizing  it  with  the  two  hands,  the  operator  gives  an  aiiemating 
rapid  uiovcn,ent,  which  agitates  the  solution,  and  makes  it,  in  less  than  a  minute,  as 

limpid  as  water.  This  movement 
is  promoted  by  a  spiral  spring,  E, 
fixed  to  the  agitator  and  the  ground, 
but  this  is  seldom  made  use  of,  be- 
cause it  is  convenient  to  be  able  10 
transport  the  agitator  from  one  place 
to  another.  When  the  agitation  is 
finished,  the  wedges  are  to  be  taken 
out,  and  the  vials  are  placed  in  order 
upon  a  table  furnished  with  round 
cells  destined  to  receive  them,  and  to 
screen  them  from  too  free  a  light. 

When  we  place  the  vials  upon  this 
table,  we  must  give  them  a  brisk  cir- 
cular motion,  to  collect  the  chloride 
of  silver  scattered  round  their  sides ; 
we  must  lift  out  their  stoppers,  and 
suspend  them  in  wire  rings,  or  pincers. 
We  next  pour  a  thousandth  of  the 
decime  solution  into  each  vial;  and 
before  this  operation  is  terminated, 
there  is  formed  in  the  first  vials, 
when  there  should  be  a  precipitate,  a 
nebulous  stratum,  very  well  marked, 
of  about  a  centimetre  in  thickness. 

At  the  back  of  the  table  there  is  a 
black  board  divided  into  compart- 
ments numbered  from  1  to  10,  upon 
each  of  which  we  mark,  wiih  chalk, 
the  thousandths  of  the  decime  liquor 
put  into  the  correspondent  vial.  The 
thousandths  of  sea  salt,  which  indicate 
an  augmentation  of  standard,  are  pre- 
ceded by  the  sign  -{-,  and  the  thou- 
sandihs  of  nitrate  of  silver  by  the  sign  — . 

When  the  assays  are  finished,  the  liquor  of  each  vial  is  to  be  poured  into  a  large 
vessel,  in  which  a  slight  excess  of  sea  salt  is  kept  ;  and  when  it  is  full,  the  supernatant 
clear  liquid  must  be  run  oflf  with  a  syphon. 

The  chloride  of  silver  may  be  reduced  without  any  perceptible  loss.  After  having 
washed  it  well,  we  immerse  pieces  of  iron  or  zinc  into  it,  and  add  sulphuric  acid  in  suffi- 
cient quantity  to  keep  up  a  feeble  disengagement  of  hydrogen  gas.  The  mass  must  not 
be  touched.  In  a  few  days  the  silver  is  completely  reduced.  This  is  easily  recognised 
by  the  color  and  nature  of  the  product ;  or  by  treating  a  small  quantity  of  it  with 
water  of  ammonia,  we  shall  see  whether  there  be  any  chloride  unreduced  ;  for  it  will 
be  dissolved  by  the  ammonia,  and  will  afterwards  appear  upon  saturating  the  ammonia 
with  an  acid.  The  chlorine  remains  associated  with  the  iron  or  the  zinc  in  a  state 
of  solution.  The  first  washings  of  the  reduced  silver  must  be  made  with  an  acidulous 
water,  to  dissolve  the  oxyde  of  iron  which  may  have  been  formed,  and  the  other  washings 
with  common  water.  After  decanting  the  water  of  the  last  washing,  we  dry  the  mass, 
and  add  a  little  powdered  borax  to  it.  It  must  be  now  fused.  The  silver  being  in  a 
bulky  powder,  is  to  be  put  in  successive  portions  into  a  crucible  as  it  sinks  down.  The 
heat  should  be  at  first  moderate ;  but  towards  the  end  of  the  operation  it  must  be  pretty 
strong  to  bring  into  complete  fusion  the  silver  and  the  scoriae,  and  to  efl'ect  their 
complete  separation.  In  case  it  should  be  supposed  t^jat  the  whole  of  the  silver  had 
not  been  reduced  by  the  iron  or  zinc,  a  little  carbonate  of  potash  should  be  added  to  the 
borax.  The  silver  may  also  be  reduced  by  exposing  the  chloride  to  a  strong  heat,  in 
contact  with  chalk  and  charcoal. 

The  following  remarks  by  M.  Gay  Lussac,  the  author  of  the  above  method,  upon  the 
efltct  of  a  little  mercury  in  the  humid  assay,  are  important : — 

It  is  well  known  that  chloride  of  silver  blackens  the  more  readily  as  it  is  exposed 
to  an  intense  light,  and  that  even  in  the  diffused  light  of  a  room,  it  becomes  soon 
sensibly  colored.  If  it  contains  four  to  five  thousandths  of  mercury,  it  does  not  blacken ; 
It  remains  of  a  dead  white  :  with  three  thousandths  of  mercury,  there  is  no  marked 
discoloring  in  diflfused  light ;  with  two  thousandths  it  is  slight ;  with  one  it  is  much 
more  marked,  but  still  it  is  much  less  intense  than  with  pure  chloride.    With  half  a 


n 


106 


ASSAY. 


ASSAY. 


107 


thousandth  of  mercury  the  difference  of  color  is  not  remarkable,  and  is  perceived  onlj 
in  a  very  moderate  light. 

But  when  the  quantity  of  mercury  is  so  small  that  it  cannot  be  detected  by  the 
difference  of  color  in  the  chloride  of  silver,  it  may  be  rendered  quite  evident  by  a  very 
simple  process  of  concentration.  Dissolve  one  gramme  of  the  silver  supposed  to  contain 
I  of  a  thousandth  of  mercury,  and  let  only  J  of  it  be  precipitated,  by  adding  only  J  of 
the  common  sail  necessary  to  precipitate  it  entirely.  In  thus  operating,  the  |  thou- 
sandth of  mercury  is  concentrated  in  a  quantity  of  chloride  of  silver  four  times  smaller : 
it  is  as  if  the  silver  having  been  entirely  precipitated,  four  times  as  much  mercury, 
equal  to  two  thousandths,  had  been  precipitated  with  it. 

In  taking  two  grammes  of  silver,  and  precipitating  only  \  by  common  salt,  the 
precipitate  would  be,  with  respect  to  the  chloride  of  silver,  as  if  it  amounted  to  four 
thousandths.  By  this  process,  which  occupies  only  five  minutes,  because  exact  weighing 
is  not  necessary,  J-  of  a  thousandth  of  mercury  may  be  detected  in  silver. 

It  is  not  useless  to  observe,  that  in  making  those  experiments  the  most  exact  manner 
of  introducing  small  quantities  of  mercury  into  a  solution  of  silver,  is  to  weigh  a  minute 
globule  of  mercury,  and  to  dissolve  it  in  nitric  acid,  diluting  the  solution  so  thnt  it 
may  contain  as  many  cubic  centimetres  as  the  globule  weighs  of  centigrammes.  Each 
cubic  centimetre,  taken  by  means  of  a  pipette,  will  contain  one  milligramme  of 
mercury. 

If  the  ingot  of  silver  to  be  assayed  is  found  to  contain  a  greater  quantity  of  mercury, 
one  thousandth  for  example,  the  humid  process  ought  either  to  be  given  up  in  this 
case,  or  to  be  compared  with  cupellation. 

When  the  silver  contains  mercury,  the  solution  from  which  the  mixed  chlorides  are 
precipitated  does  not  readily  become  clear. 

Silver  containing  mercury,  put  into  a  small  crucible  and  mixed  with  lamp-black, 
to  prevent  the  volatilization  of  the  silver,  was  heated  for  three  quarters  of  an  hour 
in  a  muffle,  but  the  silver  increased  sensibly  in  weight.  This  process  for  separating  the 
mercury,  therefore,  failed.  It  is  to  be  observed,  that  mercury  is  the  only  metal  which 
has  thus  the  power  of  disturbing  the  analysis  by  the  humid  way. 

Assaying  of  Gold. — In  estimating  or  expressing  the  fineness  of  gold,  the  whole 
mass  spoken  of  is  supposed  to  weigh  24  carats  of  12  grains  each,  either  real,  or  merely 
proportional,  like  the  assayer's  weights ;  and  the  pure  gold  is  called  fine.  Thus,  if 
gold  be  said  to  be  23  carats  fine,  it  is  to  be  understood,  that  in  a  mass,  weighing 
24  carats,  the  quantity  of  pure  gold  amounts  to  23  carats. 

lu  such  small  werk  as  cannot  be  assayed  by  scraping  off  a  part  and  cupelling  it, 
the  assayers  endeavor  to  ascertain  its  fineness  or  quality  by  the  touch.  This  is  a 
method  of  comparmg  the  color  and  other  properties,  of  a  minute  portion  of  the 
metal,  with  those  of  small  bars,  the  composition  of  which  is  known.  These  bars  are 
called  touch  needles,  and  they  are  rubbed  upon  a  smooth  piece  of  black  basaltes  or 
pottery,  which,  for  this  reason,  is  called  the  touchstone.  Black  flint  slate  will  serve 
the  same  purpose.  Sets  of  gold  needles  may  consist  of  pure  gold ;  of  pure  gold,  23^ 
carats  with  |  carat  of  silver ;  23  carats  of  gold  with  one  carat  of  silver ;  22|  carats  of 
gold  with  1|  carat  of  silver ;  and  so  on,  till  the  silver  amounts  to  four  carats ;  after 
which  the  additions  may  proceed  by  whole  carats.  Other  needles  may  be  made  in  the 
same  manner,  with  copper  instead  of  silver ;  and  other  sets  may  have  the  addition, 
consisting  either  of  equal  parts  of  silver  and  copper,  or  of  such  proportions  as  the 
occasions  of  business  require.  The  examination  by  the  touch  may  be  advantageously 
employed  previous  to  quartation,  to  indicate  the  quantity  of  silver  necessary  to  be 
added. 

In  foreign  countries,  where  trinkets  and  small  work  are  required  to  be  submitted  to 
the  assay  of  the  touch,  a  variety  of  needles  is  necessary  ;  but  they  are  not  much  used 
in  England.  They  afford,  however,  a  degree  of  information  which  is  more  considerable 
than  might  at  first  be  expected.  The  attentive  assayer  compares  not  only  the  color  of 
the  stroke  made  upon  the  touchstone  by  the  metal  under  examination,  with  that  produced 
by  his  needle,  but  will  likewise  attend  to  the  sensation  of  roughness,  dryness,  smooth- 
ness, or  greasiness,  which  the  texture  of  the  rubbed  metal  excites,  when  abraded  by  the 
stone.  When  two  strokes  perfectly  alike  in  color  are  made  upon  the  stone,  he  may 
then  wet  them  with  aquafortis,  which  will  affect  them  very  differently,  if  they  be  not 
similar  compositions  ;  or  the  stone  itself  may  be  made  red-hot  by  the  fire,  or  by  the  blow- 
pipe, if  thin  black  pottery  be  used  ;  in  which  case  the  phenomena  of  oxydation  will  differ 
according  to  the  nniure  and  quantity  of  the  alloy.  Six  principal  circumstances  appear 
to  affect  the  operation  of  parting ;  namely,  the  quantity  of  acid  used  in  parting,  or  in 
the  first  boiling  ;  the  concentration  of  this  acid ;  the  time  employed  in  its  application ; 
the  quantity  of  acid  made  use  of  in  the  reprise,  or  second  operation  ;  its  concentration ; 
and  the  time  during  which  it  is  applied.  From  experiment  it  has  been  shown,  tnat 
each  of  these  unfavorable  circumstances  might  easily  occasion  a  loss  of  from  the  half  of 


I 


a  thirty -second  part  of  a  carat,  to  two  thirty-second  parts.  The  assayers  explain  their 
technical  language  by  observing,  that  in  the  whole  mass  consisting  of  twenty -four  carats, 
this  thirty-second  part  denotes  l-768th  part  of  the  mass.  It  may  easily  be  conceived, 
therefore,  that  if  the  whole  six  circumstances  were  to  exist,  and  be  productive  of  errors, 
falling  the  same  way,  the  loss  would  be  very  considerable. 

It  is  therefor^  indispensably  necessary,  that  one  uniform  process  should  be  followed 
in  the  assays  of  gold ;  and  it  is  a  matter  of  astonishment,  that  such  an  accurate  process 
should  not  have  been  prescribed  by  government  for  assayers,  in  an  operation  of  such 
great  commercial  importance,  instead  of  every  one  being  left  to  follow  his  own 
judgment.  The  process  recommended  ki  the  old  French  official  report  is  as  follows  : — 
twelve  grains  of  the  gold  intended  to  be  assayed  must  be  mixed  with  thirty  grains  of 
fine  silver,  and  cupelled  with  108  grains  of  lead.  The  cupellation  must  be  carefully 
attended  to,  and  all  the  imperfect  buttons  rejected.  When  the  cupellation  is  ended,  the 
button  must  be  reduced,  by  lamination,  into  a  plate  of  1|  inches,  or  rather  more,  in 
length,  and  four  or  five  lines  in  breadth.  This  must  be  rolled  up  upon  a  quill,  and 
placed  in  a  matrass  capable  of  holding  about  three  ounces  of  liquid,  when  filled  up  to 
its  narrow  part.  Two  ounces  and  a  half  of  very  pure  aquafortis,  of  the  strength  of  20 
degrees  of  Baume's  areometer,  must  then  be  poured  upon  it ;  and  the  matrass  being 
placed  upon  hot  ashes,  or  sand,  the  acid  must  be  kept  gently  boiling  for  a  quarter  of  an 
hour :  the  acid  must  then  be  cautiously  decanted,  and  an  additional  quantity  of  1| 
ounces  must  be  poured  upon  the  metal,  and  slightly  boiled  for  twelve  minutes.  This 
being  likewise  carefully  decanted,  the  small  spiral  piece  of  metal  must  be  washed  with 
filtered  river  water,  or  distilled  water,  by  filling  the  matrass  with  this  fluid.  The 
vessel  is  then  to  be  reversed,  by  applying  the  extremity  of  its  neck  against  the  bottom 
of  a  crucible  of  fine  earth,  the  internal  surface  of  which  is  very  smooth.  The  annealing 
must  now  be  made,  after  having  separated  the  portion  of  water  which  had  fallen  into 
the  crucible ;  and,  lastly,  the  annealed  gol(^  must  be  weighed.  For  the  certainty  of 
this  operation,  two  assays  must  be  made  in  the  same  manner,*  together  with  a  third  as- 
say upon  gold  of  twenty-four  carats,  or  upon  gold  the  fineness  of  which  is  perfectly  and 
generally  known. 

No  conclusion  must  be  drawn  from  this  assay,  unless  the  latter  gold  should  prove  to 
be  of  the  fineness  of  twenty-four  carats  exactly,  or  of  its  known  degree  of  fineness;  for. 
if  there  be  either  loss  or  surplus,  it  may  be  inferred  that  the  other  two  assays,  having 
undergone  the  same  operation,  must  be  subject  to  the  same  error.  The  operation  being 
made  according  to  this  process  by  several  assayers,  in  circumstances  of  importance,  such 
as  those  which  relate  to  large  fabrications,  the  fineness  of  the  gold  must  not  be  depended 
upon,  nor  considered  as  accurately  known,  unless  all  the  assayers  have  obtained  a  uni- 
form result,  without  communication  with  each  other.  This  identity  must  be  considered  as 
referring  to  the  accuracy  of  half  the  thirty-second  part  of  a  carat.  For,  notwithstanding 
every  possible  precaution  or  uniformity,  it  very  seldom  happens  that  an  absolute  agree- 
ment  is  obtained  between  the  different  assays  of  one  and  the  same  ingot;  because  the 
ingot  itself  may  differ  in  its  fineness  in  different  parts  of  its  mass. 

The  phenomena  of  the  cupellation  of  gold  are  the  same  as  of  silver,  only  the  ope- 
ration is  less  delicate",  for  no  gold  is  lost  by  evaporation  or  penetration  into  the  bone- 
ash,  and  therefore  it  bears  safely  the  highest  heat  of  the  assay  furnace.  The  button 
of  gold  never  vegetates,  and  need  not  therefore  be  drawn  out  to  the  front  of  the  muffle, 
but  may  be  left  at  the  further  end  till  the  assay  is  complete.  Copper  is  retained  more 
strongly  by  gold  than  it  is  by  silver;  so  that  with  it  16  parts  of  lead  are  requisite  to 
sweat  out  1  of  copper  ;  or,  in  general,  twice  as  much  lead  must  be  taken  for  the  copper 
alloys  of  gold,  as  for  those  of  silver.  When  the  copper  is  alloyed  with  very  small  quan- 
tities of  gold,  cupellation  would  afford  very  uncertain  results;  we  must  then  have  re- 
course to  liquid  analysis. 

M.  Vauquelin  recommends  to  boil  60  parts  of  nitric  acid  at  22*  Baume,  on  the  spiral 
slip  or  cornet  of  gold  and  silver  alloy,  for  twenty-five  minutes,  and  replace  the  Ikjuid 
afterwards  by  acid  of  32°,  which  must  be  boiled  on  it  for  eight  minutes.  This  process 
is  free  from  uncertainty  when  the  assay  is  performed  upon  an  alloy  containing  a  con- 
siderable quantity  of  copper.  But  this  is  not  the  case  in  assaying  finer  gold ;  for  then 
a  little  silver  always  remains  in  the  gold.  The  surcharge  which  occurs  here  is  2  or  3 
thousandths ;  this  is  too  much,  and  it  is  an  intolerable  error  when  it  becomes  greater, 
which  often  happens.  This  evil  may  be  completely  avoided  by  employing  the  following 
process  of  M.  Chaudet.  He  takes  0*500  of  the  fine  gold  to  be  assayed ;  cupels  it  with 
1*500  of  silver,  and  1-000  of  lead;  forms,  with  the  button  from  the  cupel,  a  riband  or 
strip  three  inches  long,  which  he  rolls  into  a  comet.  He  puts  this  into  a  matrass  with 
acid  at  22°  B.,  which  he  boils  for  3  or  4  minutes.  He  replaces  this  by  acid  of  32°  B.,  and 
boils  for  ten  minutes;  then  decants  off,  and  boils  again  with  acid  of  32°,  which  must  be 
finally  boiled  for  8  or  10  minutes. 

Gold  thus  treated  is  very  pure.    He  washes  the  comet,  and  puts  it  entire  into  a  small 


I 


!     ! 


I 
I 


i 


i  I 


w 


108 


AUTOMATIC. 


f^'l^Il  P™^^^?  to  water ;  heats  the  crucible  to  duU  redness  under  the  muffle    whr^n 

cuW  property  of  platinum;  when  alloyed  with  silver,  it  becomes  soluble   nnitrLac^d 
Therefore  by  a  proper  quartation  of  the  alloy  by  cupellation,  and  boiling  the  bu  ton  w  th 
nitric  acid,  we  may  get  a  residuum  of  pure  gold.     If  we  were  to  treat  the  h.mnn  Z-fV^ 
sulphuric  acid,  however,  we  should  dissolve  nothing  but  the  sTlver.    Se  copperTer^^^^ 
removed  by  cupellation     Hence,  supposing  that  we  have  a  quaternary  coSnd  of  con^ 

denotes  the  copper.    This  button,  treated  by  sulphuric  add,  will  suffer  a  losrof  welS 
equal  to  the  amount  of  silver  present.    The  residuum,  by  quartation  with  silver  anTtoS 
ing  with  nitric  acid,  will  part  with  its  platinum,  and  the  gold  wSl  remaTpure     For" 
more  detailed  explanations,  see  Platinum  remain  pure.     Uor 

ohiiTfn^"?  WEIGHTS  OK  ATOMS,  are  the  primal  quantities  in  which  the  different 
ejects  of  chemistry,  simple  or  compound,  combine  with  each  other,  referred  to  a  common 

^,hP  ct    ?' rr^'     ^•'^^^""  ^  ^'^'^'"^^  ^y  ««^«  philosophers,  and  hX4n  by  oZrs 
^,«;„t.i^    .I'i'^^  comparison.    Every  chemical  maniifacturer  should  be  ifroulhir 
quamted  with  the  combinmg  ratios,  which  are,  for  the  same  two  substences  noronlv  defi 
n  te,  but  multiple;  two  great  truths,  upon  which  are  founded  not  merdy  the  rL^onal  of 
h.s  operations,  but  also  the  means  of  modifying  them  to  useful  our nolLTtlT^ 

nijh!  Khi^i  't?  y^S^table  alkali  extracted  from  the  Atropa  belladonna,  or  deadly 
night-shade.  It  is  composed  of  about  YO-98  carbon  1-fi'iU'^^f.JZ  a.qo  ^^*^^^X 
10-36  oxygen  in  100  parfs.  It  is  prepared  by  t,S^hoeX^^^^^^^^ 
^lZ\Z  T"'"?' '^"'."f  of  "'.^''■•y.  with  eauitic  sodatmto  sligE  kallne  reac  on  a^d 
k  token  ni  hi  5h.°"/'.,""\*l""'"°  "."<■  "  '.'"If  """^s  its  voIuL  of  ether  The  atC"a 
h,(T.il7t^  !•"■'  ^^i  "«"'"  dopo'it'd  f'om  it  when  the  elhereous  solution  U 
™Mt.  tni  h"  T*  -'T    ^'"^  »'•««*■"'"■*  with  ether  is  repeated  upon  the  S  prec^ 

^  ACTAR  OF  Rm?-'5    TT  PT    ^"""'  P?"^'"'  "^  prcseribid.  ^ 

iTTTmvrlSrrJv^r^?;.  ®««0"?'  Volatile,  and  Perfumery 

AUTOM  4Tir  i  t™-     kT'?  f '^'  "  ?'■??«'•■"'»»  »f  tin ;  ,.hieh  see. 

tne  McisMtude  of  language,  it  has  now  come  to  signify  every  extensive  nroduPt  of 
art  which  18  made  by  machinery,  with  little  or  no  aid  of  the  human  hand  srthat  th. 
most  perfect  manufacture  is  that  which  dispenses  entirely  withZnua^Lor^It^8 
m  our  modern  cotton  and  flax  mills  that  automatic  opei4ons  aTe  dtplaved^  mo  t 
advantage;  for  there  the  elemental  powers  have  been  made  to  aniSe  milHornf 
complex  organs,  imparting  to  forms  W  wood,  iron  and  bmss!  an  iSofenT  iracv 

Us  noVe'rcreat^^^^^^^     masterpieces,  so  may  the  philosophy  of  manufactures  in  these 

The  constant  aim  and  effect  of  these  automatic  improvements  in  the  arts  are  nhilnn 
thropic,  as  they  tend  to  relieve  the  workman  either  from  niches  of  adiltmrtwr^^^^ 

rn"rt"htt^^^^    T' ""'  'T  p^"''"'  .-petitir:ftffot  whS^^^^^^^^^^^^ 

work  neon^e  ad  ^U  I"^  '    arranged  power-mill  combines  the  opemtion  of  many 

work  people,  adult  and  young,  in  tending  with  ass  duoiis  skill  a  svsteni  of  nrodnotivi 
machines  continuously  Impelled  by  a  central  force.      How  vastly  condlh^^^ 
commercial  greatness  of  a  nation,  and  the  comforts  of  mankind  irumanndusti^  can 

n^tre'fittunTo  "^'-  ^'Tf'T^  '"^  '\'  ^^^"^^^  '^  muscular^ZTwh^h  s  b^fu 
nature  fitliil  and  capricious,  but  when  made  to  consist  in  the  task  of  guiding  the  work 

bvTomeTnll^^^^^^^  "l^  •"?  ''^''}'^^  ^"P^^^^^^'  ^^^^  ^^"^^  precision  aifdvei^-it;, 
by  some  ndefatigable  physica  agent,  is  apparent  to  every  visitor  of  our  cotton  flax 
silk,  wool,  and  machine  factories.  This  great  era  in  the  useful  urts  is  mainly  due  t^ 
the  genius  of  Ark  w right  Prior  to  the  introduction  of  his  system,  manufactures  were 
every  where  feeble  and  fluctuating  in  their  development,  shooting  forth  luxuHanlTfor 
^^  .T;/"! ^^''"'^  withering  almost  to  the  roots  like  annual  plants.  TheirTerennial 
growth  then  began,  and  attracted  capital,  in  copious  streams,  to  irrigate  the  r  clfrmak. 


Philosophy  of  Manufkctures,  p.  1. 


t  Ibid.,  p.  2. 


' 


AUTOMATON. 


109 


of  industry.  When  this  new  career  commenced,  about  the  year  1770,  the  annual 
consumption  of  cotton  in  British  manufactures  was  under  four  millions  of  pounds' 
weight,  and  that  of  the  whole  of  Christendom  was  probably  not  more  than  ten  millions. 
In  1850  the  consumption  in  Great  Britain  and  Ireland  was  about  five  hundred  and 
eighty-eight  millions  of  pounds,  and  that  of  Europe  and  the  United  States  together  one 
thousand  and  ninety-two  millions.  In  our  spacious  factory  apartments  the  benignant 
power  of  steam  summons  around  him  his  myriads  of  willing  menials,  and  assigns  to  each 
the  regulated  task,  substituting  for  painful  muscular  effort  upon  their  part,  the  energies 
of  his  own  gigantic  arm,  and  demanding  in  return,  only  attention  and  dexterity  to  cor- 
rect such  little  aberrations  as  casually  occur  in  his  workmanship.  Under  his  auspices 
and  in  obedience  to  Arkwright's  polity,  magnificent  edifices,  surpassing  far  in  number, 
value,  usefulness,  and  ingenuity  of  construction,  the  boasted  monuments  of  Asiatic, 
Egyptian,  and  Roman  despotism,  have,  within  the  short  period  of  fifly  years,  risen  up 
in  this  kingdom,  to  show  to  what  extent  capital,  industrj',  and  science,  may  augment 
the  resources  of  a  state,  while  they  meliorate  the  condition  of  its  citizens.  Such  is  the 
automatic  system,  replete  with  prodigies  in  mechanics  and  political  economy,  which 
promises,  in  its  future  growth,  to  become  the  great  minister  of  civilization  to  the  ter- 
raqueous globe,  enabling  this  country,  as  its  heart,  to  diffuse,  along  with  its  commerce, 
the  life-blood  of  knowledge  and  religion  to  myriads  of  people  still  lying  "  in  the  region 
and  shadow  of  death."*  Of  these  truths,  the  present  work  affords  decisive  evidence  in 
almost  every  page. 

AUTOMATON.  In  the  etymological  sense,  this  word  (self-working)  signifies  every 
mechanical  construction  which,  by  virtue  of  a  latent  intrinsic  force,  not  obvious  to  com- 
mon eyes,  can  carry  on,  for  some  time,  certain  movements  more  or  less  resembling  the 
results  of  animal  exertion,  without  the  aid  of  external  impulse.  In  this  respect,  all  kinds 
of  clocks  and  watches,  planetariums,  common  and  smoke  jacks,  with  a  vast  number  of  the 
machines  now  employed  in  our  cotton,  silk,  flax,  and  wool  factories,  as  well  as  in  our 
dyeing  and  calico  printing  works,  may  be  denominated  automatic.  But  the  term,  auto- 
maton, is,  in  common  language,  ajxpropriated  to  that  class  of  mechanical  artifices  in  which 
the  purposely  concealed  power  is  made  to  imit,ate  the  arbitrary  or  voluntary  motions  of 
living  beings.  Human  figures,  of  this  kind,  are  sometimes  styled  Androidcsy  from  the 
Greek  term,  like  a  man. 

Although,  from  what  we  have  said,  clock-work  is  not  properly  placed  under  the 
head  automaton,  it  cannot  be  doubted  that  the  art  of  making  clocks,  in  its  prosressive 
improvement  and  extension,  has  given  rise  to  the  production  of  automata.  The  most 
of  these,  in  their  interior  structure,  as  well  as  in  the  mode  of  applying  the  moving 
power,  have  a  distinct  analogy  with  clocks  ;  and  these  automata  are  frequently  mounted 
in  connexion  with  watch  work.  Towards  the  end  of  the  13th  century,  several  tower 
clocks,  such  as  those  at  Strasburg,  Lubec,  Prague,  Olmutz,  had  curious  mechanisms 
attached  to  them.  The  most  careful  historical  inquiry  proves  that  automata,  properly 
speaking,  are  certainly  not  older  than  irftceZ-clocks ;  and  that  the  more  perfect  struc- 
tures of  this  kind  are  subsequent  to  the  general  introduction  of  sjortwg-clocks.  Many 
accounts  of  ancient  automata,  such  as  the  flying  doves  of  Archytas  of  Tarenlum*. 
Regiomontanus's  iron  flies,  the  eagle  which  flew  towards  the  emperor  Maximilian,  iii 
Nuremburg,  in  the  year  1470,  were  deceptions,  or  exaggerated  statements;  for,  three  such 
masterpieces  of  art  would  form  now,  with  every  aid  of  our  improved  mechanisms,  the 
most  difficult  of  problems.  The  imitation  of  flying  creatures  is  extremely  diflicult,  for 
several  reasons.  There  is  very  little  space  for  the  moving  power,  and  the  only  ma- 
terial possessed  of  requisite  strength  being  metal,  must  have  considerable  wcicrht.  Two 
automata,  of  the  celebrated  French  mechanician,  Vaucauson,  first  exhibited  in  the  year 
1738,  have  been  greatly  admired ;  namely,  a  flute-player,  five  and  a  half  feet  high,  with 
its  cubical  pedestal,  which  played  several  airs  upon  the  German  flute ;  and  that,  not  by 
any  interior  tube-work,  but  through  the  actual  blowing  of  air  into  the  flute,  the  motion 
of  the  tongue,  and  the  skilful  stopping  of  the  holes  with  the  fingers ;  as  also  a  duck, 
which  imitated  many  motions  of  a  natural  kind  in  the  most  extraordinary  manner. 
This  artist  has  had  many  imitators,  of  whom  the  brothers  Droz  of  Chaux  de  Fonds 
were  the  most  distinguished.  Several  very  beautiful  clock  mechanisms  of  theirs  are 
known.  One  of  them  with  a  figure  which  draws;  another  playing  on  the  piano;  a  third 
which  writes,  besides  numerous  other  combined  automata.  Frederick  Von  Knauss 
completed  a  writing  machine  at  Vienna,  in  the  year  1760.  It  is  now  in  the  model 
cabinet  of  the  Polytechnic  Institute,  and  consists  of  a  globe  2  feet  in  diameter,  con- 
taining the  mechanism,  upon  which  a  figure  7  inches  high  sits,  and  writes  upon  a  sheet 
of  paper  fixed  to  a  frame,  whatever  has  been  placed  beforehand  upon  a  regulating  cy- 
linder. At  the  end  of  every  line,  it  rises  and  moves  its  hand  sideways,  in  order  to  begin 
a  new  line. 

Very  complete  automata  have  not  been  made  of  late  years,  because  they  are  very 

*  Philosophy  of  Manufactures,  p.  18 


110 


AUTOMATON. 


h 


ii 


1 


I 


expensive;  and  by  soon  satisfying  curiosity,  they  cease  to  interest     Ino-^nlnn-  «,^ 
cl.,nic,ans  find  themselves  betir  ?ewarded%di7ecting  their Xts  to  t^^^^^^^^^^ 

Fr^n  Ph  I     f    1     T  ^  Vienna,  and  a  similar  work  of  KaufFmann,  at  Dresden      In 
Httri  ^T^"'*^"u  ''''"•^  ""^^''^  "^°^'"""  *«  °^«^«  "^i""te  automata  which  exci'te  no 
als^lS  h?  U  '"'^  ^V«'"g'°,^  T"7  ^''^^'  ^^^^  ^'^"^'^^  movements  of  a  naturarkfnd 
aJso  little  birds,  sometimes  hardly  three-(juarter8  of  an  inch  long,  in  snuff-boxes  and 
watches  of  enamelled  gold      Certain  artificial  figures  which  have  been  denominated 
t^J^JJ  •^^'^"^  deserve  the  name;  since  trick  and  confederacy  are  more  or  Ccon- 
cemed  m  their  operation.    To  this  head  belong  a  number  of  figures  anparenily  sprakTns 
by  mechanism;  a  clock  which  begins  to  strike,  or  to  play,  when  a  nerson  St«  n 
Sign  of  holding  up  his  finger;    this  effect   being  probabV prlduc^ed   ^  a   c^"^^^^^^ 
green-finch,  or  other  little  bird,  instructed  to  set  off  the  detente  of  the  wheelwork  ^  a 
«gnal.     It  IS  likely,  also,  that  the  chess  player  of  Von  Kempelen,  which  excited  to  much 
wonder  m  the  last  century,  had  a  concealed  confederate.    Likewise  the  very  ingenious 

ie  ^  Sn\T™L  ;f  E^sene^^^^   •""Xr^  "'^^'  ^"^^^f'  ^"^^^^^  hors'emen  and  rope  Z! 
cers,  constructed  at  i^isenerz,  m  Styria,  are  probably  no  more  true  automata  than  thp 

{^yT^Z'Zitziot"''''''  '"'*  "^ """'"«'  -  ^-'  perfect  rr ;  ;„w"„s'o? 

The  moving  power  of  almost  all  automata  is  a  wound-up  steel  sprin.'  •  because  in  mm 
parison  w.lh  other  means  of  giving  motion,  it  takes  up  the  smaUesTrcJ>m  is  easiest  ^^^^^^ 
cealed,  and  set  a-go,ng.  Weights  are  seldom  employed,  and  only  in  a  n^rt^ll  ITv  Th; 
employment  of  other  moving  powers  is  more  iimitedl  sometimes  fine  3  is  mLetoTaH 
on  the  circumference  of  a  wheel,  by  which  the  rest  of  the  mechanism  h  moved  plrthi 
^me  purpose  water  has  been  employed ;  and,  when  it  is  made  to  yXn to  an  at^cham^^^^^^^ 
It  causes  sufficient  wind  to  excite  musical  sounds  in  pipes.  In  particular  cases  a uiScsil' 
V*  has  been  used,  as,  for  example,  in  the  Chinese  tumblers,  whE  only  a  nhvlc^ui 
paratus  to  illustrate  the  doctrine  of  the  centre  of  gravity  ^     physical  ap- 

Figures  are  frequently  constructed  for  playthings  which  move  by  wheels  hardlv  vi.iWi. 
An  example  of  this  simplest  kind  of  automaton  which  may  be  LS^rced  here   aliUi^ 
trating  the  self-acting  principles  of  manufactures,  is  shown  in   he Xure  ' 

Fig.  102  exhibits  the  outlines  of  an  automaton,  representing  a  swan    with  M,it«M. 
combm^ovements.     The  mechanism  may  be 'described,  fo?  ^h^sake  of  cleaJnes's 

of   explanation,   under   dis- 
tinct heads.  The  first  relates 
to  the  motion  of  the  whole 
figure.    By  means  of   this 
part  it  swims  upon  the  water, 
in   directions  changed  from 
time  to  time  without  exterior 
agency.     Another  construc- 
tion gives  to  the  figure  the 
faculty  of  bending  its  neck  on 
several    occasions,    and     to 
such  an  extent  that  it  can 
plunge  the  bill  and  a  portion 
of   the   head   under   water. 
Lastly,  it  is  made  to  move 
its   head   and   neck    slowly 
from  side  to  side. 

On  the  barrel  of  the  spring, 
wheel    thprp  ie  »  r««;«  ,„i,    i  i    j  .      , .  ^  exterior  to  the  usual  ratchet 

The  wheel  2  movP.Tl  n  '  ""^'^^  ^'  '^^^"'^  ^^'"^^  ^"^^  ^^^  P^"'""  «^  l^e  wheel  2. 
of  thriatter  Tlfth!  ffu  ''"^.'  ''^^'^'^  "^^'^^^  ^"  ^«««J  1'"^^,  and  on  the  long  axis 
lotJ  by  \he  ^^^^^^  %'7h''  %Z^^''^  or  water.wheel,  the  paddles  of  which  are 
open^  in  the  bouom  of  ih.  fii  ""^  '^'^^  rudder-wheels  extend  through  an  oblong 
nf  ♦!!»  oH  1  i^  ^^  ^'"""^  "^"^^  »n*«  t^e  water.  They  turn  in  the  direction 
of  the   arrow,  and  impart  a  straight-forward  movement  to  the  swan      The  chamW 

Lir th'p  rpJnr iT''"''  ;;'^"^"'»  if  "'^^^  ^^'^^  ^^'^t,  to  prevent  moisture  blinf thrown 
Tft^-1  fr  /  ^  "machinery.  By  the  wheel  4,  motion  is  conveyed  to  the  flj  pinionl 
the  fly  Itself  6,  serves  to  regulate  the  working  of  the  whole  apparatus,  and  it  is  provWed 
nll^nr'^R^'  """^  '^''^''  '"  '^^  engraving,  to  bring  it  to  rest,  or'  set  a  goTni^ 
pleasure.  Here,  as  we  may  imagine,  the  path  pursued  is  rectdinear,  when  the  rudder 
wheels  are  made  to  work  ma  square  direction.  An  oblique  bar,  seen  only  in  «=ec?^m 
at  6,  moveable  about  its  midd  e  point,  carries  at  each  Pnd  «  wpK  rLf  ?u  .  Vu  ™"*" 


AUTOKATON^. 


Ill 


is  effected  without  other  agency.  For  this  purpose,  the  wheel  1  takes  into  the  pinion  Y, 
and  this  carries  round  the  crown-wheel  8,  which  is  fixed,  with  an  eccentric  disc  9,  upon 
a  common  axis.  While  the  crown-wheel  moves  in  the  direction  of  the  arrow,  it  turns 
the  smaller  eccentric  portion  of  the  elliptic  disc  towards  the  lever  m,  which,  pressed 
upon  incessantly  by  its  spring,  assumes,  by  degrees,  the  position  corresponding  with  the 
middle  line  of  the  figure,  and  afterwards  an  oblique  position ;  then  it  goes  back  again, 
and  reaches  its  first  situation  ;  consequently  through  the  reciprocal  turning  of  the  bar  A, 
and  the  swim-foot,  is  determined  and  varied  the  path  which  the  swan  must  pursue. 
This  construction  is  available  with  all  automata,  which  work  by  wheels  ;  and  it  is  ob- 
vious, that  we  may,  by  different  forms  of  the  disc  9,  modify,  at  pleasure,  the  direction 
and  the  velocity  of  the  turnings.  If  the  disc  is  a  circle,  for  instance,  then  the  changes 
will  lake  place  less  suddenly;  if  the  disc  has  an  outward  and  inward  curvature,  upon 
whose  edge  the  end  of  the  lever  presses  with  a  roller,  the  movement  will  take  place  in  a 
serpentine  line. 

The  neck  is  the  part  which  requires  the  most  careful  workmanship.  Its  outward  case 
must  be  flexible,  and  the  neck  itself  should  therefore  be  made  of  a  tube  of  spiral  wire, 
covered  with  leather,  or  with  a  feathered  bird-skin.  The  double  line  in  the  interior, 
where  we  see  the  triangles  «,  e,  e,  denotes  a  steel  spring  made  fast  to  the  plate  10,  which 
forms  thebottom  of  the  neck ;  it  stands  loose,  and  needs  to  be  merely  so  strong  as  to 
keep  the  neck  straight,  or  to  bend  it  a  little  backwards.  It  should  not  be  equally 
thick  in  all  points,  but  it  should  be  weaker  where  the  first  graceful  bend  is  to  be  made ; 
and,  in  general,  its  stiffness  ought  to  correspond  to  the  curvature  of  the  neck  of  this  bird. 
The  triangles  e  are  made  fast  at  their  base  to  the  front  surface  of  the  spring ;  in  the 
points  of  each  there  is  a  slit,  in  the  middle  of  which  a  moveable  roller  is  set,  formed  of  a 
smoothly  turned  steel  rod.  A  thin  catgut  string/,  runs  from  the  upper  end  of  the 
spring,  where  it  is  fixed  over  all  these  rollers,  and  passes  through  an  aperture  pierced 
in  the  middle  of  10,  into  the  inside  of  the  rump.  If  the  catgut  be  drawn  straight 
back  towards  /,  the  spring,  and  consequently  the  neck,  must  obviously  be  bent, 
and  so  much  the  more,  the  more  tightly  /  is  pulled,  and  is  shortened  in  the  hollow  of 
the  neck.  Hpw  this  is  accomplished  by  the  wheel-work  will  presently  be  shown.  The 
wheel  11  receives  its  motion  from  the  pinion  s,  connected  with  the  main- wheel  1. 
Upon  11  there  is,  moreover,  the  disc  12,  to  whose  circumference  a  slender  chain  is 
fastened.  When  the  wheel  11  turns  in  the  direction  of  the  arrow,  the  chain  will  be  so 
much  pulled  onwards  through  the  corresponding  advance  at  the  point  at  12,  till  this 
point  has  come  to  the  place  opposite  to  its  present  situation,  and,  consequently,  11  must 
have  performed  half  a  revolution.  The  other  end  of  the  chain  is  hung  in  the  groove 
of  a  very  moveable  roller  14 ;  and  this  will  be  turned  immediately  by  the  unwinding  of 
the  chain  upon  its  axis.  There  turns,  in  connexion  with  it,  however,  the  large  roller  13, 
to  which  the  catgut  /  is  fastened ;  and  as  this  is  pulled  in  the  direction  of  the  arrow, 
the  neck  will  be  bent  until  the  wheel  1 1  has  made  a  half  revolution.  Then  the  drag 
ceases  again  to  act  upon  the  chain  and  the  catgut ;  the  spring  in  the  neck  comes  into 
play :  it  becomes  straight,  erects  the  neck  of  the  animal,  and  turns  the  rollers  13  and 
14,  back  into  their  first  position. 

The  roller.  13  is  of  considerable  size,  in  order  that  through  the  slight  motion  of  the 
roller  14,  a  sufficient  length  of  the  catgut  may  be  wound  off,  and  the  requisite  short- 
ening of  the  neck  may  be  effected ;  which  results  from  the  proportion  of  the  diameters 
of  the  rollers  11,  13,  and  14.  This  part  of  the  mechanism  is  attached  as  near  to  the 
side  of  the  hollow  body  as  possible,  to  make  room  for  the  interior  parts,  but  particularly 
for  the  paddle-wheels.  Since  the  catgut,/,  must  pass  downwards  on  the  middle  from 
10,  it  is  necessary  to  incline  it  sideways  and  outwards  towards  13,  by  means  of  some 
small  rollers. 

The  head,  constituting  one  piece  with  the  neck,  will  be  depressed  by  the  complete 
flexure  of  this ;  and  the  bill,  being  turned  downwards  in  front  of  the  breast,  will  touch 
the  surface  of  the  water.  The  head  will  not  be  motionless ;  but  it  is  joined  on  both 
sides  by  a  very  moveable  hinge,  with  the  light  ring,  which  forms  the  upper  part  of  the 
clothing  of  the  neck.  A  weak  spring,  g,  also  fastened  to  the  end  of  the  neck,  tends  to 
turn  the  head  backwards ;  but  in  the  present  position  it  cannot  do  so,  because  a  chain 
at  g,  whose  other  end  is  attached  to  the  plate  10,  keeps  it  on  the  stretch.  On  the  bending 
of  the  neck,  this  chain  becomes  slack ;  the  spring  g  comes  into  operation,  and  throws 
the  head  so  far  back,  that,  in  its  natural  position,  it  will  reach  the  water. 

Finally,  to  render  the  turning  of  the  head  and  the  neck  practicable,  the  latter  is  not 
closely  connected  with  the  rump,  while  the  plate  10  can  turn  in  a  cylindrical  manner 
upon  its  axis,  but  cannot  become  loose  outwardly.  Moreover,  there  is  upon  the  axis  of 
the  wheel  1,  and  behind  it  (shown  merely  as  a  circle  in  the  engraving)  a  bevel  wheel, 
which  works  into  a  second  similar  wheel,  15,  so  as  to  turn  it  in  a  horizontal  direction. 
The  pin  16>  of  the  last  wheel,  works  upon  a  two-armed  lever  19,  moveable  round  the 
point  hf  ar.d  this  lever  moves  the  neck  by  means  of  the  pin  17.     The  shorter  arm  of  the 


I 


I 


112 


AUTOMATON'. 


'^'^^ell^^^^^^                                                                «ta„as.  As  soon  as  this  ,n  eon. 
es  the  oval  ring  ouTw^ dfon'i  s  :r^:n:l-" LmU 

point  h,  into  the  oblique  directirshown  bv  f  h/;!^/^^^  1"/°'  ^^^  ^^^^r  upon  the 

on  ns  way  right  opposite  toTs  or ll^^^^^^^^^^^  ^hepin  16,  having  come 


opposite  side;  and  atlast,  when  iTh^^sTade  an   ^^^^^^^^^^  to  the 

The  longer  arm  of  the  lever  follows,  of  cour4   these  nU  J.      !•     '  '*  ''  ^"'^^  straight. 

t  turns  the  neek  upon  its  plate  10,  by  niean;  of  the  ' '"  i  r"""^'?^  movements,  so  that 

this  comes  into  the  dotted  position^  Tmw  be  £^   \' 5°?'  *«  18  denotes  the  bill. 


105 


io  d^We'^heToL^tur^^^  ^^«!P^/n  it.     The  man  appen. 

four  wheels  of  the  carriage  Sv^notrex^^^^^  ^^^°^  ,^"-  ^-   front.'V 

some  parts  are  represented  ^von  Tlar^^  Z^e  T^T}.^  fT-^^^^^  ^^  Jig- 105, 
through  the  two  carrier  wheels  ipon  the  wheerm-irl.^  I  /t^  K'""  ^^'  ^O^,  operates 
of  these  two  wheels,  the  feet  are  "e  in  mot  L  T.  1  A^'r^*  .^^'  ""^^"^  °^  the  axis 
hinder  foot,  move  themselves  backwards  St.  lie  l^u  ^f ,,^«^«-^««^  «.  then  the  right 
in  Iheir  hoofs,  whUe  the  Iwo  oSTe^  irrw  nn^  •''Vk^  ^'^""^  ^"''^  '"^^^^  tacks 
takes  place.  The  carriage,  ho4vi°wirwhTeh  ^t .  '''^^  ^"^  ''''  "^^^^^^  °^  ^^^  ^^^^ 
its  wheels.  By  studying  the  mechanism  of  he  JooJ  a  anVt^r^^^^^^^  ^^'T^  -"P^" 
we  can  readilv  understand  the   nrinpinl^«  «f  ♦/      '    '  the  parts  connected  with  it, 

crank-shaped  on  both  sides  where7f^J?«  ?  ^  movement.  The  axis  of  wheel  4  is 
each  foot,'it  isbentin  an  i^po   te^^^^^^^^^^^^  but  for 

This  crank,  or  properiv  its  parf  ^"the^t  from  ih.  i'-'^^'^^"^  '?  the  front  view;?g.l04. 
the  swan,  and  moves  like  it  in  an  oval  sDor«  l.^n'>'  oT''  '"^tead  of  the  pin  J6,  in 
motion  through  tooth-work  but  not  n\  nTh.  ^'•^^•1^'^'  » two-armed  lever,  which  gives 
work  renders  the  motirsmoo^^r     V^^^^^^^^^^^  ^^^^^^  pin.  This  wheel! 

which  it  turns  alternatelv,  to  the  ^ne  and  Ihe  other  s id.  >  '  ^"/"""J  ^1  "'•^^-  ^^^'^^"t 
wheel  4.     The  toothed  arrh  or  ii!!  LI?    the  other  side,  by  virtue  of  the  rotation  of  the 

lever,  in  a  simillitct^u^n   th^upt^^^^^^^^^^^  ^^'^  "^  a  shorter 

backward  upon  the  p  vot  7"  In  virtue  of  th.  »-^^'  ^"^'^^  i'  "'^^^^  ^"^^rd  and 
the  foot  a  will  move  itseirhrs  ob^^luelv  btw°'r'  -.  '^'  J''"^'^^°^  °^  '^^  ^rrow. 
will  thereby  bend  itself  fo  ward  ^IZtJh^^Zl^'T'f'''''^  ^^"^^?'  ^"^  the  boa, 
both  the  other  feet  are  rai  ed  and  bent  The  fnVnt^".  t\  makes  the  same  motion, 
of  hinges,  which  are  so  constructed  tlmi  tl^ey  carvfelf  nn  fnn'.'  ""'.t  '"?  '  '^^  ''°™«' 
every  oblique  position  of  the  foot  Wifh  n,o  L^  •  I"  ^"""^^^^  ^han  is  necessary  at 
lever  turns  itseVabout  J,  in  an  inVer^ed  dir^^^^^^^^^^  !^^   wheel  4,  the 

foot-joint  forward,  so  tha  it  form^I^Lcute  an^le  w^^^.' w  -"^^^^  ^^  "PPcnnost 
now  twice  bent  upon  its  joints.  Th?s  takes  nlfce  bv  th.  ;  ^^  '\^'T'  ^^^  ^«ot  is 
is  led  over  rollers  (as  the  drawing  sLws)  to'  he  fo^'^^^^^^^^  *''.''!!?  ''  7^'^^ 

upper  end  has  its  fixed  point  in  the  interior  of  ihM^  is  th  fastened.  As  its 
the  eccentric  pin  r  stand'in,^  in   the  vi    n  ty  of  '^'L^^U  '^^' 

hinges.    If  there  was  space  for  it,  a  rollL  would'a'nsl^^  b'eUer  than  fU'   bJ 


AVENTURINK 


118 


the  recedure  of  the  uppermost  joint  into  the  first  position,  the  tension  of  the  chain  t 
ceases  again  of  itselC  while  the  pin  r  removes  from  it,  and  the  foot  is  again  extended 
in  a  straight  line  by  the  small  springs  operating  upon  its  two  under  parts,  which  were 
previously  bent  stitfly  by  the  chain.  By  the  aid  of  the  figures  with  this  explanation, 
it  will  be  apparent  that  all  the  fore  feet  have  a  similar  construction,  that  the  proper 
succession  of  motions  will  be  effected  through  toothed  arcs,  and  the  position  of  the 
cranks  on  the  axis  of  the  wheels  4  and  6,  and  hence  the  advance  of  the  figure  most 
follow.  The  wheel  6  puts  the  fly  7  in  motion,  by  means  of  the  small  wheel  marked  1; 
on  the  fixed  points  of  the  4  chains,  by  means  of  a  ratchet-wheel  and  a  catch,  the  ne- 
cessary tension  will  again  be  produced  when  the  chains  have  been  drawn  out  a  little. 
There  is  sufficient  room  for  a  mechanism  which  could  give  motion  to  the  head  and 
ears,  were  it  thought  necessary. 

The  proper  cause  of  the  motions  may  now  be  explained.  In  Jig.  105,  a,  is  a  wheel 
connected  with  the  wound-up  spring,  by  which  the  motion  of  the  two  human  figures, 
and  also,  if  desired,  that  of  the  horse  may  be  effected.  The  axis  of  the  wheel  b  carries 
a  disc  with  pins,  which  operate  upon  the  two-armed  lever  with  its  fulcrum  c,  and  thn« 
causes  the  bending  of  the  upper  part  of  one  of  the  figures,  which  has  a  hinge  tXf. 
On  the  axis  of  that  wheel  there  is  a  second  disc  c,  for  giving  motion  to  the  other 
figure ;  which,  for  the  sake  of  clearness,  is  shown  separate,  although  it  should  sit 
alongside  of  its  fellow.  On  the  upper  end  of  the  double-armed  lever  d,  there  is  a 
cord  whose  other  end  is  connected  with  the  moving  arm,  in  the  situation  i,  and  raises 
it  whenever  a  pin  in  the  disc  presses  the  under  part  of  the  lever.  A  spring  h  brings 
the  arm  back  into  the  original  position,  when  a  pin  has  passed  from  the  lever,  and  has 
left  it  behind.  The  pins  at  c  and  d  may  be  set  at  different  distances  from  the  middle 
of  the  disc,  wheieby  the  motions  of  the  figures  by  every  contact  of  another  pin,  are 
varied,  and  are  therefore  not  so  uniform,  and  consequently  more  natural. 

For  the  connection  of  both  mechanisms,  namely,  the  carriage  with  the  horse,  vari- 
ous arrangements  may  be  adopted.  Two  separate  traction  springs  should  be  employ- 
ed ;  one  at  a,  Jig.  105,  in  the  coach-seat ;  the  other  in  the  body  of  the  horse.  In  th« 
coach-seat  at  6,  the  fly  with  its  pinion,  as  well  as  a  ratchet-wheel,  is  necessary.  By  means 
of  the  shaft,  the  horse  is  placed  in  connection  with  the  wagon.  It  may,  however, 
receive  its  motion  from  the  spring  in  the  carriage,  in  which  case  one  spring  will  be  suf- 
ficient. Upon  the  latter  plan  the  following  construction  may  be  adopted : — ^To  the 
axis  of  h,Jig.  105,  a  bevel  wheel  is  to  be  attached,  and  from  this  the  motion  is  to  be 
transmitted  to  the  bottom  of  the  carriage  with  the  help  of  a  second  bevel  wheel  «^ 
connected  with  a  third  bevel  wheel  t.  This  again  turns  the  wheel  it,  whose  long 
axis  V  goes  to  the  middle  of  the  horse's  body,  in  an  oblique  direction,  through  the  hol- 
low shaft  This  axis  carries  an  endless  screw  9,  Jig.  103,  with  very  oblique  threads, 
which  works  into  the  little  wheel  8,  corresponding  to  the  wheel  1,  through  an  open- 
ing in  the  side  of  the  horse,  and  in  this  way  sets  the  mechanism  of  the  horse  a-going. 
With  this  construction  of  Jig.  105,  a  spring  of  considerable  strength  is  necessary,  or 
if  the  height  of  the  carriage-seat  does  not  afford  sufficient  room,  its  breadth  will  an- 
swer for  placing  two  weaker  springs  alongside  of  each  other  upon  a  common  barrel 

AVENTUllINK  According  to  Wohler's  examination,  aventurine  glass  owes  its 
golden  iridescence  to  a  crystalline  separation  of  metallic  copper  from  the  mass  col- 
ored brown  by  the  peroxide  of  iron. 

In  the  aventurine  glaze  for  porcelain  a  crystalline  separation  of  green  oxide  of 
chromium  from  the  brown  ferruginous  mass  of  the  glaze  produces  a  similar  effect 
This  glaze  is  j^repared  as  follows  : 

31  parts  of  fine  lixiviated  dry  porcelain  earth  from  Halle, 

43  do.  do.        dry  quartz  sand, 

14  do.  do.        gypsum, 

12  do.  do.        fragments  of  porcelain, 

are  stirred  up  with  300  parts  of  water,  and  by  repeated  straining  through  a  linen  sieve 
uniformly  suspended  in  it,  and  intimately  mixed.  To  this  paste  is  added,  under  con- 
stant agitation  and  one  after  the  other,  aqueous  solutions  of 

19  parts  bichromate  of  potash, 
100     "       protosulphate  of  iron, 
47     "       acetate  of  lead, 
and  then  so  much  solution  of  ammonia  that  the  iron  is  completely  separated.     The 
salts  of  potash  and  ammonia  are  removed  by  frequent  decantation  with  spring  water. 
The  baked  porcelain  vessels  are  dipped  into  the  pasty  mixture  obtained  as  above 
described  in  the  same  manner  as  with  other  glazes,  and  then  fired  in  the  porcelain 
furnace.     After  this  they  appear  covered  with  a  brown  glaze,  which  in  reflected  light 
appears  to  be  filled  with  a  countless  number  of  light  gold  spangles. 
Vol.  L 


114 


BALANCE 


A  thm  fragment  of  the  glass  appears,  under  the  microscope,  by  transmitted  light,  as 
a  clear  brownish  glass,  in  which  numerous  transparent  green  six-sided  prisms  ol  oxide 
of  chromium,  and  some  brownish  crystals,  probably  of  oxide  of  chromium  and  perox- 
ide of  iron,  are  suspended.  The  oxide  of  chromium  therefore  separates,  on  the  slow 
©ooling  of  the  glaze  in  the  porcelain  furnace,  from  the  substance  of  the  glaze — a  sili- 
cate of  potash,  lime,  and  alumina — saturated  with  the  peroxide  of  iron,  and  shinea 
through  the  brownish  mass  with  a  golden  color.  When  the  aventurine  glaze  is 
mixed  with  an  equal  amount  of  colorless  porcelain  glaze,  the  glassy  mass  no  lono-er 
has  a  brown  color  after  the  burning,  but  a  light  greenish-grav,  and  the  eliminated 
erystalline  spangles  likewise  exhibit  in  reflected  light  their  natural  green  color. 

AXE.  A  tool  much  used  by  carpenters  for  cleaving,  and  roughly  fashioning,  blocks 
of  wood.  It  is  a  flat  iron  wedge,  with  an  oblong  steel  edge,  parallel  to  which,  in  the 
■hort  base,  is  a  hole  for  receiving  and  holding  fast  the  end  of  a  strong  wooden  handle. 
In  the  coi.per's  adze,  the  oblong  edge  is  at  right  angles  to  the  handle,  and  is  slightly 
ourved  up,  or  inflected  towards  it. 

AXLES,  of  carriages — See  Wheel  Carriages. 

AXUNGE     Hog's  lard ;  see  Fat  and  Oils. 

AZOBENZOLDE,  and  AZOBENZOYLE,  products  of  the  action  of  pure  water 
of  ammonia  upon  oil  of  bitter  almonds,  by  making  the  ammonia  pass  down  through  a 
^  A  vrvTM^^  ^^^"^^  with  the  almond  pap.     The  operation  must  be  continued  for  weeks. 

AZOTIZED,  said  of  certain  vegetable  substances,  which,  as  containing  azote,  were 
Bopposed  at  one  time  to  partake,  in  some  measure,  of  the  animal  nature  ;  most  animal 
bodies  being  characterized  by  the  presence  of  much  azote  in  their  composition.  The  veg- 

A  Int^i^^T^^-^"*^'^'^' ^^^^^°^' ^*"^^°'  and  many  others,  contain  abundance  of  azote. 

AZUKE,  the  tine  blue  pigment,  commonly  called  smalt,  is  a  glass,  colored  with  ox- 
ide of  cobalt,  and  ground  to  an  impalpable  powder. 

The  manufacture  of  azure,  or  smalt,  has  been  lately  improved  in  Sweden,  by  the 
adoption  of  tlie  following  process : — 

The  cobalt  ore  is  first  roasted  till  the  greater  part  of  the  arsenic  is  driven  oflF.  The 
residuary  impure  black  oxide  is  mixed  with  as  much  sulphuric  acid  (concentrated)  as 
wiU  make  it  into  a  paste,  which  is  exposed  at  first  to  a  moderate  heat,  then  to  a 
cherry-red  ignition  for  an  hour.  The  sulphate  thus  obtained  is  reduced  to  powder, 
and  dissolved  in  water.  To  the  solution,  carbonate  of  potash  is  gradually  added,  in 
order  to  separate  the  remaining  portion  of  oxide  of  iron;  the  quantity  of  which'de- 
pends  upon  the  previous  degree  of  calcination.  If  it  be  not  enough  oxidized,  the 
iron  IS  ditticidt  to  be  got  rid  of 

When,  from  the  color  of  the  precipitate,  we  find  that  the  potash  separates  merely 
carbonate  of  cobalt^  it  is  allowed  to  settle,  the  supernatant  liquor  is  decanted,  and 
precipitated,  by  means  of  a  solution  of  silicate  of  potash,  prepared  as  follows  : — 

Ten  parts  of  potash  are  carefully  mixed  with  fifteen  parts  of  finely  ground  flints  or 
sand,  and  one  part  of  pounded  charcoal.  This  mixture  is  melted  in  a  crucible  of  brick 
day,  an  operation  which  requires  steady  ignition  during  6  or  6  hours.  The  mass, 
when  melted  and  pulverized,  may  be  easily  dissolved  in  boiling  water,  adding  to  it,  by 
little  at  a  time,  the  glass  previously  ground.  The  filtered  solution  is  colorless,  and 
keeps  well  in  the  air,  if  it  contains  one  part  of  glass  for  5  or  6  of  water.  The  silicate 
of  cobalt  which  precipitates  upon  mixing  the  two  solutions,  is  the  preparation  of  co- 
balt most  smtabl©  for  painting  upon  porcelain,  and  for  the  manufacture  of  blue  glass. 
Bee  Cobalt. 

B. 

BABLAH.  The  rind  or  shell  which  surrounds  the  fruit  of  the  mimosa  cineraria  ; 
it  eomes  from  the  East  Indies,  as  also  from  Senegal,  under  the  name  of  Neb-neb.  It 
eontams  gallic  acid,  tannin,  a  red  coloring  matter,  and  an  azotized  substance ;  but 
tlie  proportion  of  tannin  is  smaller  than  in  sumach,  galls,  and  knoppern  (gall-nuts  of 
the  eouunon  oak)  in  reference  to  that  of  gallic  acid,  which  is  considerable  in  the  bab- 
lah.  It  has  been  used,  in  dying  cotton,  for  producing  various  shades  of  drab;  as  a 
Bubetitute  for  the  more  expensive  astringent  dye-stuffs. 

BAGASSE  The  sugar-cane,  in  its  dry,  crushed  state,  as  delivered  from  the  sugar- 
m.»L     It  is  much  employed  for  fuel  in  the  colonial  sugar-houses. 

BAKING.  {Quire,  Fr.  Backen,  Germ.)  The  exposure  of  any  body  to  such  a  heat 
as  will  dry  and  consolidate  its  parts  without  wasting  them.  Thus  wood,  pottery,  and 
porcelain,  are  baked,  as  well  as  bread. 

BALANCE — ^To  conduct  arts,  manufacturers,  and  mines,  with  judgment  and  success, 
recourse  must  be  had,  at  almost  every  step,  to  a  balance.  Experience  proves  that  all 
material  bodies,  existing  upon  the  surface  of  the  earth,  are  constantly  solicited  by  a 
force  which  tends  to  bring  them  to  its  centre,  and  that  they  actually  fall  towards  it 


BALANCE. 


115 


when  they  are  free  to  move.  This  force  is  called  gravity.  Though  the  bodies  be 
not  free,  tha  effort  of  gravity  is  still  sensible,  and  the  resultant  of  all  the  actions 
which  it  exercises  upon  their  material  points  constitutes  what  is  popularly  called 
their  weight.  These  weights  are,  therefore,  forces  which  may  be  compared  together, 
and  bv  means  of  machines  may  be  made  to  correspond  or  be  counterpoised. 

To  discover  whether  two  weiffhts  be  equal,  we  must  oppose  them  to  each  other  in  a 
machine  where  they  act  in  a  similar  manner,  and  then  see  if  they  maintain  an  equi- 
librium ;  for  example,  we  fulfil  this  condition  if  we  suspend  them  at  the  two  extremities 
of  a  lever,  supported  at  its  centre,  and  whose  arms  are  equal.  Such  is  the  general  idea 
of  a  balance.  The  beam  of  a  good  balance  ought  to  be  a  bar  of  well-tempered  steel,  of 
Buch  form  as  to  secure  perfect  inflexibility  under  any  load  which  may  be  fitly  applied 
to  its  extremities.  Its  arms  should  be  quite  equal  in  weight  and  length  upon  each  side 
of  its  point  of  suspension  ;  and  this  point  should  be  placed  in  a  vertical  line  over  the 
centre  of  gravity  ;  and  the  less  distant  it  is  from  it,  the  more  delicate  will  be  the  balance. 
Were  it  placed  exactly  in  that  centre,  the  beam  would  not  spontaneously  recover  the 
horizontal  position  when  it  was  once  removed  from  it.  To  render  its  indications  more 
readily  commensurable,  a  slender  rod  or  needle  is  fixed  to  it,  at  ri^ht  angles,  in  the  line 
passing  through  its  centres  of  gravity  and  suspension.  The  point,  or  rather  edge  of 
suspension,  is  made  of  perfectly  hard  steel,  and  turns  upon  a  bed  of  the  same.  For 
common  uses  the  arms  of  a  balance  can  be  made  sufficiently  equal  to  give  satisfactory 
results ;  but,  for  the  more  refined  purposes  of  science,  that  equality  should  never  be 
presumed  nor  trusted  to ;  and,  fortunately,  exact  weighing  is  quite  independent  of  that 
equality.  To  weigh  a  body  is  to  determine  how  many  limes  the  weight  of  that  body 
contains  another  species  of  known  weijiht,  as  of  grains  or  pounds,  for  example.  In 
order  to  find  it  out,  let  us  place  the  substance,  suppose  a  piece  of  gold,  in  the  left  hand 
scale  of  the  balance ;  counterpoise  it  with  sand  or  shot  in  the  other,  till  the  index 
needle  be  truly  vertical,  or  stand  in  the  middle  of  the  scale,  proving  the  beam  to  be 
horizontal.  Now  remove  gently  the  piece  of  gold,  and  substitute  in  its  place  standard 
multiple  weights  of  any  graduation,  English  or  French,  till  the  needle  again  resumes  tho 
vertical  position,  or  till  its  oscillations  upon  either  side  of  the  zero  point  are  equaL 
These  weights  will  represent  precisely  the  weight  of  the  gold,  since  they  are  placed  in 
the  same  circumstances  precisely  with  it,  and  make  the  same  equilibrium  with  the  weight 
laid  in  the  other  scale. 

This  method  of  v.eighing  is  obviously  independent  of  the  unequal  length  as  well  as 
the  unequal  weight  of  the  arms  of  the  beam.     For  its  perfection  two  requisites  only  are 
indispensable.     The  first  is  that  the  points  of  suspension  should  be  rigorously  the  same 
m  the  two  operations;  for  the  power  of  a  given  weight  to  turn  the  beam  being  unequal, 
according  as  we  place  it  at  diflTcrent  distances  from  the  centre  of  suspension,  did  that 
point  var>'  in  the  two  consecutive  weighings,  we  would  require  to  employ,  in  the  second, 
a  different  weight  from  that  of  the  piece  of  gold,  in  order  to  form  an  equilibrium  with 
the  sand  or  shot  originally  put  in  the  opposite  scale ;  and  as  there  is  nothing  to  indicate 
such  inequality  m  the  states  of  the  beam,  great  errors  would  result  from  it.     The  best 
mode  ot  securing  agamst  such  inequality  is  to  suspend  the  cords  of  the  scales  from 
sharp  ed^ed  rings,  upon  knife  edges,  at  the  ends  of  the  beam,  both  made  of  steel  sc 
hard  tempered  as  to  be  incapable  of  indentation.      Tlie  second  condition  is,  that  the 
balance  should  be  very  sensible,  that  is,  when  in  equilibrium  and  loaded,  it  may  be 
disturbed,  and  its  needle  may  oscillate,  by  the  smallest  weight  put  into  either  of  the 
scales.    This  sensibility  depe^is  solel;jr  upon  the  centre  or  nail  of  suspension ;  and  it 
will  be  the  more  perfect  the  less  friction  there  is  between  that  knife-edge  surface  and 
the  plane  which  supports  it     Both  should  therefore  be  as  hard  and  highly  polished  as 
possible;  and  should  not  be  suftered  to  press  against  each  other,  except  at  the  time  of 
weiiijiing.     Every  delicate  balance  of  moderate  size,  moreover,  should  be  suspended 
within  a  glass  case,  to  protect  it  from  the  agitations  of  the  air,  and  the  corroding 
influence  of  the  weather.      In  some  balances  a  ball  is  placed  upon  the  index  or  needle 
(whether  that  index  stand  above  or  below  the  beam),  which  may  be  made  to  approach 
or  recede  from  the  beam  by  a  fine-threaded  screw,  with  the  effect  of  varying  the 
centre  of  gravity  relatively  to  the  point  of  suspension,  and  thereby  increasing,  at  will, 
either  the  sensibility,  or  the  stubility  of  the  balance.    The  greater  the  length  of  the  arms, 
the  less  distant  the  centre  of  gravity  is  beneath  the  centre  of  suspensiim,  the  better 
polished  its  central  knife-edge  of  30°,  the  lighter  the  whole  balance,  and  the  less  it  is 
loaded,  the  greater  will  be  its  sensibility.      In  all  cases  the  arms  must  be  quite  in- 
flexible.    A  balance  made  by  Ramsden  tor  the  Royal  Society  is  capable  of  weighing 
ten  pounds,  and  turns  with  one  hundredth  of  a  grain,  which  is  the  seven-millionth 
part  of  the  weight.     In  pointing  out  this  balance  to  me  one  evening.  Dr.  Wollaston 
told  me  It  was  so  delicate,  that  Mr.  Pond,  then  astronomer  royal,  when  making  some 
observations  with  it,  found  its  indications  affected  by  his  relative  position  before  it 
although  It  was  mclosed  in  a  glass  case.     When  he  stood  opposite  the  right  arm,  that 


116 


BALANCE  FOR  WEIGHING  COrN". 


end  of  the  beam  preponderated,  in  consequence  of  its  becoming  expanded  by  the  radi- 
ation of  heat  from  his  body ;  and  when  he  stood  opposite  the  left  arm,  he  made  this 
preponderate  in  its  turn.  It  is  probable  that  Mr.  Pond  had  previously  adjusted  the 
centres  of  gravity  and  suspension  so  near  to  each  other  as  to  give  the  balance  its  maxi- 
mum sensibility,  consistent  with  stability.  Were  these  centres  made  to  coincide,  the 
beam,  when  the  weights  are  equal,  would  rest  in  any  position,  and  the  addition  of  the 
smallest  weight  would  overset  the  balance,  and  place  the  beam  in  a  vertical  position, 
from  which  it  would  have  no  tendency  to  return.  The  sensibility  in  this  case  would 
be  the  greatest  possible ;  but  the  other  two  requisites  of  level  and  stability  would  be 
entirely  lost.  The  case  would  be  even  worse  if  the  centre  of  gravity  were  higher  than 
the  centre  of  suspension,  as  the  balance  When  deranged,  if  free,  would  make  a  revolution 
of  no  less  than  a  semi-circle.  A  balance  may  be  made  by  a  fraudulent  dealer  to  weigh 
falsely  though  ita  arms  be  equal,  provided  the  suspension  be  as  low  as  the  centre  of 
gravity,  for  he  has  only  to  toss  his  tea,  for  instance,  forcibly  into  one  scale  to  cause  15 
ounces  of  it,  or  thereby,  to  counterpoise  a  pound  weight  in  the  other.  Inspectors  of 
weights,  <fec.,  are  not  au  fait  to  this  fruitful  source  of  fraud  among  hucksters. 

BALANCE  FOR  WEIGHING  COIN  at  the  Bank  of  England,  invented  by 
William  Cotton,  Esq.,  Governor  of  the  Bank. 

The  new  coinage  nrst  arrives  at  the  Bank  from  the  Mint  in  what  are  called  "journies," 
a  single  journey  weighing  16  lbs,"  and  containing  701  sovereigns.  The  officers  of  the 
Mint  are  allowed  12  gv&ina  plus  in  every  pound  weight  of  metal,  for  the  irregularities 
incidental  to  working  it  into  coin ;  but  they  usually  work  to  within  one  half  of  that 
allowance,  which  is  technically  called  "  the  remedy." 

There  was  coined  for  the  Bank  in  the  spring  of  1843,  8,000,000  of  sovereigns,  and 
the  greatest  variation  from  the  weight  allowed  was  only  60  grains,  or  one  third  of  the 
remedy.  Each  sovereign  should  contain  a  portion  of  this  remedy,  to  allow  for  wear  in 
public  use ;  and  this  extraordinary  subdivision  of  metal  is  invariably  obtained.  The 
usual  delivery  of  new  coinage  at  the  Bank  contains  100  journies,  which  is  counted  by 
weight  only,  that  is,  200  sovereigns  are  counted  into  one  scale,  and  the  rest  of  the  deli- 
very is  weighed  in  parcels  which  balance  these  200,  and  this  is  all  the  counting  the 
new  coinage  receives.  The  regularity  and  precision  of  the  manipulations  at  the  Mint 
obviate  the  necessity  of  any  further  examination,  either  as  regai  da  the  gross  amount 
or  the  weight  of  an  individual  piece. 

When  the  currency  returns  to  the  Bank  from  the  public,  it  becomes  necessary  to 
ascertain  if  it  has  been  reduced  below  the  standard  weight,  and  this  imposes  an  arduous 
duty  on  the  officers  of  the  Bank.  The  amount  of  gold  paid  daily  over  the  Bank  counter 
varies  considerably,  but  3O,0h0O  may  be  taken  as  a  rough  average ;  and  hence  arises  a 
tedious,  irksome,  and  expensive  process  in  weighing  so  large  a  number  of  pieces  singly, 
and  in  quick  succession,  separating  at  the  same  time  the  light  from  the  standard  coin. 

The  mode  of  weighing  coins  by  hand  requires  much  dexterity,  practice  and  attention ; 
but,  in  spite  of  all  these,  errors  were  inevitable,  and  it  was  to  obviate  these  that  the 
machine  was  invented  by  Mr.  Cotton,  the  Governor  of  the  Bank  of  England ;  it  was 
constructed  from  his  plans  bj  Mr.  Napier,  and  is  thus  described : — 

Its  exterior  presents  a  plain  brass  case,  with  a  small  hopper  tube  on  the  top  plate, 
about  4i  inches  from  which  there  is  an  opening  in  the  top  plate.  In  this  opening  is 
seen  a  platform  in  the  form  of  a  quadrant  This  platform  is  suspended  above  one  end 
of  the  beam,  and  is  to  receive  the  coin  to  be  weighed-  On  one  side  of  the  case  is  a  till 
to  receive  the  sov^eigns  as  they  are  weighed,  partitioned  so  that  one  division  is  left  for 
standard  coin,  and  the  other  for  such  as  are  light  There  is  a  sliding  door  to  each  divi- 
sion for  removing  the  coins  at  pleasure.  The  machine  may  be  worked  like  a  clock, 
with  a  weight,  or  by  any  simple  application  of  power. 

Its  visible  action  is  as  follows:— The  hopper  being  filled  with  gold,  upon  setting  the 
machine  m  motion,  it  immediately  places  a  sovereign  on  the  little  platform,  which 
serves,  as  already  stated,  in  place  of  a  scale  plan  ;  and  if  it  is  of  standard  weight  a  small 
tongue  comes  rapidly  forward  and  pushes  the  sovereign  into  that  side  of  the  till  allotted 
to  such  com ;  if  light,  another,  and  similar  tongue  to  the  first,  pushes  the  sovereign  into 
the  other  side  of  the  till     The  action  of  these  tongues  is  at  right  angles  to  each  other. 

While  a  sovereign  is  being  weighed,  a  succeeding  one  is  on  its  way  from  the  hopper 
to  the  platform,  and  the  moment  the  preceding  sovereign  is  disposed  of,  according  to  its 
value,  another  is  placed  in  its  stead.  To  keep  the  hopper  supplied  with  gold,  and 
remove  it  from  the  till  as  it  is  filled,  is  all  the  attendance  necessary.  The  more  minute 
parts  of  the  naechanical  arrangement  of  the  machine,  such  as  the  fulcrum,  the  forceps, 
Ac,  are  described  in  detail ;  and  the  following  statement  by  Mr.  Miller  is  given  as  a 
comparison  with  the  old  method  of  weighing: — 

"  With  the  bullion-scales  4,000  may  be  stated  as  the  number  a  person  can  weigh  in 
six  hours.  As  the  sovereigns  now  tendered  at  the  Bank  counter  are  most  of  them  new, 
the  scale  dips  quickly  in  weighing,  and  one  person  can  weigh  6,000  in  six  hours ;  but  a 


'  > 


I 


BALANCE  FOR  WEIGHING  COIN. 


117 


1 


Bhort  time  ago,  before  the  issue  of  the  new  coinage,  the  same  person  could  weigh  only 
3,000,  as  it  took  a  longer  time  for  the  scales  to  indicate. 

"  The  bullion  scales  cannot  indicate  nearer  than  4-lOOths  of  a  grain,  at  the  above 
rate. 

"  The  machine  is  perfectly  free  from  the  sources  of  error  to  which  the  scales  are 
subject,  and  weighs  as  quickly,  whether  the  sovereigns  are  new  and  of  full  weighty 
or  old  and  doubtful ;  it  can  weigh  10,000  in  six  horns,  and  divide  coin  varying  only 
one-fiftieth  of  a  grain." 

The  paper  is  illustrated  by  two  drawings  of  the  internal  arrangement  of  the  machine, 
*nd  a  model,  showing  the  action  of  the  tongues  and  platform. 

Mr.  Oldham  exhibited,  at  the  Institute  of  Civil  Engineers,  the  automaton  balance  at 
work,  weighing  coin,  and  after  describing,  with  the  aid  of  a  diagram  and  model,  the 
action  of  some  of  the  more  delicate  parts  of  the  machine,  he  observed,  that  in  seeking 
to  obtain  extraordinary  performances  by  machinei-v  .mechanical  propriety  of  construc- 
tion was  too  often  overlooked,  and  premature  deterioration,  in  the  action  of  many 
parts,  was  the  result 

The  automaton  balance  was  peculiarly  worthy  of  notice,  from  the  judgment  exercised 
in  its  relative  proportions,  as  was  provea  by  the  fact  that  after  being  at  work  for  several 
months,  it  had  become  more  delicate  in  detecting  slight  variations  between  standard 
and  light  coin,  than  when  it  was  first  constructed.  Mr.  Cotton's  object  in  this  invention 
should  be  well  understood.  Public  convenience  demanded  great  accuracy  in  weighing 
the  currency :  by  the  ordinary  mode  of  weighing  gold  with  the  bullion  scales,  although 
it  was  due  to  the  banktellers  to  state  that  they  gave  the  utmost  attention  to  their  mono- 
tonous duty,  it  was  nearly  impossible  to  guard  against  the  various  difficulties  detailed 
in  the  paper.  The  injury  sustained  by  the  optic  nerve,  from  constantly  watching  the 
indicator  of  the  scales,  was  a  serious  inconvenience  to  the  operative,  which,  coupled 
with  the  incidental  sources  of  error  referred  to,  created  even  greater  absence  of  deli- 
cacy than  the  papers  stated.  Errors  to  the  amount  of  one-third,  or  even  half  a  grain, 
were  not  unfrequent 

By  the  "  automaton  balance,"  the  number  weighed  in  a  given  time  was  increased, 
and  undeviating  accuracy  obtained-  The  delicacy  of  the  instrument  was  such,  that 
from  thirty  to  thirty-five  coins  per  minute  could  be  passed  through  the  machine,  de- 
tecting a  difference  of  only  one-fifth  of  a  grain. 

It  should  be  mentioned,  that  ^uch  greater  delicacy  could  be  accomplished ;  that  is, 
to  the  one  hundredth  of  a  grain,  out  not  at  the  same  rate  ;  because  it  would  be  under- 
stood that  a  slow  action  of  the  beam  was  necessary  for  very  small  variations,  and  that 
must  regulate  the  speed  of  working;  but  such  delicacy  was  beyond  all  useful  purposes 
in  those  transactions  which  it  was  intended  to  improve. 

Mr.  Cotton  said  that  his  attention  had  been  attracted  to  the  point  by  the  incon- 
veniences to  which  the  "  tellers"  were  subjected  in  weighing  gold  for  the  public;  with 
balances  so  delicately  constructed  as  the  bullion-scales,  the  agitation  of  the  air,  by  the 
sudden  opening  of  a  door,  or  even  by  the  breathing  of  those  around,  sufficed  to  cause 
eriors.  It  was  possible,  also,  by  pressing  the  fulcrum  against  the  bridle,  to  produce 
such  a  degree  of  friction  as  materially  to  interfere  with  accuracy  ;  and  the  tellers  con- 
fessed that  after  weighing  two  or  three  thousand  coins,  the  sight  was  injured,  and  they 
no  longer  observed  with  the  same  degree  of  correctness.  He  therefore  imagined  that 
a  machine  might  be  contrived,  which,  being  defended  from  external  influence,  might 
weigh  coins  as  fast  as  by  hand,  and  within  one-fourth  of  a  grain ;  but  he  certainly  did 
not  contemplate  attaining  such  perfection  as  the  machine  now  possessed.  His  first 
idea  was,  that  the  light  coins  should  be  taken  off  by  forceps,  and  that  those  of  average 
weight  should  be  pushed  off  by  the  succeeding  ones ;  but  it  was  found  that  the  slightest 
inaccuracy  in  the  milled  edges  sufficed  to  give  them  a  wrong  direction ;  therefore  when 
he  had  made  the  first  rough  sketch,  and  consulted  with  his  friend,  the  late  Mr.  Ewart, 
he  recommended  that  Mr.  Napier,  of  York  Road,  Lambeth,  should  be  employed  to 
make  the  machine,  and  to  him  was  due  the  suggestion  of  the  two  alternately  advancing 
tongues,  as  well  as  several  other  arrangements  of  the  machinery,  which  he  had  so 
successfully  constructed. 

^  When  the  first  machine  was  tried,  out  of  1000  sovereigns  IfiO  were  found  to  be 
light  They  were  given  to  a  teller  to  be  verified,  and  he  returned  several  of  them  aa 
being  of  the  proper  weight ;  but,  on  again  weighing  them  more  carefully,  the  results 
given  by  the  machine  were  found  to  be  correct.  As  an  instance  of  how  many  circum- 
Blances  should  betaken  into  consideration  in  delicate  machines,  he  might  mention,  that 
after  being  used  for  a  time,  the  machine  varied  in  its  results,  and,  on  examination,  it 
was  discovered,  that  the  end  of  the  lever  which  traversed  the  pendant  had  become 
magnetic,  and  thus  affected  the  balance.  An  ivory  end  was  substituted,  and  ever  since 
tliat  period  its  accuracy  had  been  maintained- 

Mr.  W.  Miller  observed  that  the  efficiency  of  any  scales  must  be  determined,  in  a 
great  degree,  by  the  fineness  of  the  edge  of  the  fulcrum  of  the  beam ;  and  it  would  be 


118 


BALSAMS. 


11 


easily  imagined  that  the  friction,  to  which  the  edee  in  a  pair  of  bullion  scales  was 
subjected,  whilst  weighing  5000  or  6000  sovereigns  per  day,  must  soon  impair  its 
delicacy,  and  consequently  the  efficiency  of  the  whole  apparatus  ;  for,  whether  the 
sovereigns  were  light  or  heavy,  the  beam  must  turn  upon  its  fulcrum.  Such  was  not 
the  case  with  Mr.  Cotton's  machine ;  its  beam  did  not  act  at  all,  unlesa  a  light  sov- 
ereign was  placed  upon  the  platform ;  so  that,  among  1000  sovereigns,  if  only  100 
were  light,  the  beam  of  the  machine  would  onljr  move  100  times,  while  that  of  the 
ordinary  scales  would  oscillate  1000  times.  An  immense  advantage  was  thus  given 
to  the  machine  in  point  of  durability. 

All  weighing  was  but  an  approach  to  correctness,  and  the  nearest  point  to  which  the 
best  kind  of  common  scales  were  sensible,  might  be  stated  as  y^  jths  of  a  grain,  and 


4th  of  a  grain  would  hardly  cover  their  errors;  but  the  machine  was  sensible  to  j-jgths 
of  a  grain,  and^^ths  would  fully  cover  its  errors,  which  were  not  a  twentietn  part 
so  numerous  as  tliose  of  the  scales. 

BALSAMS  (Baumesj  Ft.  Balsame,  Germ.)  are  native  compounds  of  ethereal  or 
essential  oils,  with  resin,  and  fretjuently  benzoic  acid.  Most  of  them  have  the  con- 
sistence of  honey ;  but  a  few  are  solid,  or  become  so  by  keepin?.  They  flow  either 
spontaneously,  or  by  incisions  made  from  trees  and  shrubs  in  tropical  climates.  They 
possess  peculiar  powerful  smells,  aromatic  hot  tastes,  but  lose  their  odoriferous  pro- 
perties by  long  exposure  to  the  air.  They  are  insoluble  in  water;  soluble,  to  a  con- 
siderable degree,  in  ether;  and  completely  in  alcohol.  When  distilled  with  water, 
ethereal  oil  comes  over,  and  resin  remains  in  the  retort. 

1.    BAI.SAMS    WITH    BENZOIC    ACID  : 

Balsam  of  Peru  is  extracted  from  the  myroxylon  peruiferumy  a  tree  which  grows  in 
Peru,  Mexico,  &c. ;  sometimes  by  incision,  and  sometimes  by  evaporating  the  decoction 
of  the  bark  and  branches  of  the  tree.  The  former  kind  is  very  rare,  and  is  imported 
in  the  husk  of  the  cocoa-nut,  whence  it  is  called  balsam  eii  coque.  It  is  brown,  trans- 
parent only  in  thin  layers,  of  the  consistence  of  thick  turpentine ;  an  agreeable  smell, 
an  acrid  and  bitter  taste ;  formed  of  two  matters,  the  one  liquid,  the  other  cranular, 
and  somewhat  crjstalline.  In  100  parts,  it  contains  12  of  benzoic  acid,  88  of  resin, 
with  traces  of  a  volatile  oil. 

The  second  sort,  the  black  balsam  of  Peru,  is  much  more  common  than  the  pie- 
ceding,  translucent,  of  the  consistence  of  well-boiled  simp,  very  deep  red-brown 
color,  an  almost  intolerably  acrid  and  bitter  taste,  and  a  stronger  smell  than  the  other 
balsam.  Stoltze  regards  it  as  formed  of  69  parts  of  a  peculiar  oil,  20'7  of  a  resin,  little 
soluble  in  alcohol,  of  6*4  of  benzoic  acid,  of  0-6  of  extractive  matter,  and  09  of 
water.  . 

From  its  high  price,  balsam  of  Peru  is  often  adulterated  with  copaiba,  ofl  of  tur- 
pentine, and  olive  oil.  One  thousand  parts  of  good  balsam  should,  by  its  benzoic 
acid,  saturate  75  parts  of  crystallized  carbonate  of  soda.  It  is  employed  as  a  perfume 
for  pomatums,  tinctures,  lozenges,  sealing-wax,  and  for  chocolate  and  liqueurs,  instead 
of  vanilla,  when  this  happens  to  be  very  dear 

Liquid  ambeTy  Storax  or  StyraXy  flows  from  the  leaves  and  trunk  of  the  liquid  amber 
shjracijlua,  a  tree  which  grows  in  Virginia,  Louisiana,  and  Mexico.  It  is  brownish 
ash-gray,  of  the  consistence  of  turpentine,  dries  up  readily,  smells  agreeably,  like  ben- 
zoin, has  a  bitterish,  sharp,  burning  taste ;  is  soluble  in  4  parts  of  alcohol,  and  contains 
only  1-4  per  cent,  of  benzoic  acid. 

Balsam  of  Tolu  flows  from  the  trunk  of  the  myroxylon  tolui/trum,  a  tree  which  grows  in 
South  America ;  it  is,  when  fresh,  of  the  consistence  of  turpentine,  is  brownish-red, 
dries  into  a  yellowish  or  reddish  brittle  resinous  mass,  of  a  smell  like  benzoin ;  is  soluble 
in  alcohol  and  ether ;  aflbrds,  with  water,  benzoic  acid. 

Chinese  varnish  flows  from  the  bark  of  the  jSugia  sinensis ;  it  is  a  greenish  yellow 
turpentine-like  substance,  smells  aromatic,  tastes  strong  and  rather  astringent,  in  thin 
layers  dries  soon  into  a  smooth  shining  lac,  and  consists  of  resin,  ethereous  oil,  and  ben- 
zoic acid.  It  is  soluble  in  alcohol  and  ether ;  and  has  been  employed,  immemorially, 
in  China,  for  lackering  and  varnishing  surfaces,  either  alone  or  colored. 

Balsams  without  benzoic  acid  : — 

Copaiva  balsam,  balsam  of  copahu  or  capivi,  is  obtained  from  incisions  made  in  the 
trunk  of  the  Copaifera  officinalis,  a  tree  which  grows  in  Brazil  and  Cayenne.  It  is  pale 
yellow,  middling  liquid,  clear  transparent,  has  a  bitter,  sharp,  hot  taste;  a  penetrating 
disagreeable  smell ;  a  specific  gravity  of  from  0-950  to  0*996.  It  dissolves  in  absolute 
alcohol,  partially  in  spirit  of  wine,  forms  with  alkalis,  crystalline  compounds.  It  con- 
sists of  45*59  ethereous  oil,  52*75  of  a  yellow  brittle  resin,  and  1*66  of  a  brown  viscid 
resin.  The  oil  contains  no  oxygen,  has  a  composition  like  oil  of  turpentine,  dissolves 
caoutchouc  (according  to  Durand),  but  becomes  oxydized  in  the  air,  into  a  peculiar 
species  of  resin.  This  balsam  is  used  for  making  paper  transparent,  for  certain  lackers, 
and  in  medicine. 


BANDANNA. 


119 


i 


\ 


This  substance,  which  is  extensively  used  in  medicine,  is  often  adulterated.  For- 
merly some  unctuous  oil  was  mixed  with  it,  but  as  this  is  easily  discovered  by  ita 
insolubility  in  alcohol,  castor  oil  has  since  been  used.  The  presence  of  this  cheaper  cil 
may  be  detected,  1,  by  agitating  the  balsam  with  a  solution  of  caustic  soda,  and 
setting  the  mixture  aside  to  repose ;  when  the  balsam  will  come  to  float  clear  on  th« 
top,  and  leave  a  soapy  thick  magma  of  the  oil  below ;  2,  when  the  balsam  ia  boiled 
with  water,  in  a  thin  film,  for  some  hours,  it  will  become  a  brittle  resin  on  cooling,  but 
it  will  remain  viscid  if  mixed  with  castor  oil ;  3,  if  a  drop  of  the  oil  on  white  paper  be 
held  over  a  lamp,  at  a  proper  distance,  its  volatile  oil  will  evaporate  and  leave  the 
brittle  resin,  without  causing  any  stain  around,  which  the  presence  of  oil  will  produce; 
4,  when  three  drops  of  the  balsam  are  poured  into  a  watch-glass,  alongside  of  on© 
drop  of  sulphuric  acid,  it  becomes  yellow  at  the  point  of  contact,  and  altogether  of  a 
saflfron  hue  when  stirred  about  with  a  glass  rod,  but  if  sophisticated  with  castor  oil, 
the  mixture  soon  becomes  nearly  colorless  like  white  honey,  though  after  some  time 
the  acid  blackens  the  whole  in  either  case ;  5,  if  3  parts  in  bulk  of  the  balsam  be 
mixed  with  1  of  good  water  of  ammonia  (of  0'970  sp.  grav.)  in  a  glass  tube,  it  will 
form  a  transparent  solution,  if  it  be  pure,  but  will  form  a  white  liniment  if  it  con- 
tains castor  oil ;  6,  if  the  balsam  be  triturated  with  a  little  of  the  common  magnesia 
alba,  it  will  form  a  clear  solution,  from  which  acids  dissolve  <  jit  the  magnesia,  and 
leave  the  oil  transparent,  if  it  be  pure,  but  opaque  if  it  be  adulterated.  When  tur- 
pentine is  employed  to  falsify  the  balsam,  the  fraud  is  detected  by  the  smell  on  heat- 
ing the  compound. 

Mecca  balsam,  or  opobalsam,  is  obtained  both  by  incisions  of,  and  by  boiling,  the 
branches  and  leaves  of  the  Balsamodendron  Gileadense,  a  shrub  which  grows  in  Arabia 
Felix,  Lesser  Asia,  and  Egypt.  When  fresh  it  is  turbid,  whitish,  becomes,  by  degrees, 
transparent ;  yellow,  thickish,  and  eventually  solid.  It  smells  peculiar,  but  agreeable ; 
tastes  bitter  and  spicy ;  does  not  dissolve  completely  in  hot  spirit  of  wine,  and  contains 
10  per  cent,  of  ethereous  oil,  of  the  specific  gravity  0*876. 

Japan  lac  varnish  flows  from  incisions  in  the  trunk  of  the  Rhus  Vemix  (Melanorrhta 
usilata)  which  is  cultivated  in  Japan,  and  grows  wild  in  North  America.  The  juice 
becomes  black  in  the  air ;  when  purified,  dissolves  in  very  little  oil ;  and,  mixed  with 
coloring  matter,  it  constitutes  the  celebrated  varnish  of  the  Japanese. 

For  Benzoin  and  Turpentine,  see  these  articles  in  their  alphabetical  places. 

BANDANNA.  A  style  of  calico  printing,  in  which  white  or  brightly  colored 
ypots  are  produced  upon  a  red  or  dark  ground.  It  seems  to  have  been  practised  from 
time  immemorial  in  India,  by  binding  up  firmly  with  thread,  those  points  of  the  cloth 
which  were  to  remain  white  or  yellow,  while  the  rest  of  the  surface  was  freely  subjected 
to  the  dyeing  operations. 

The  European  imitations  have  now  far  surpassed,  in  the  beauty  and  precision  of 
the  design,  the  oriental  patterns ;  having  called  into  action  the  refined  resources  of 
mechanical  and  chemical  science.  The  general  principles  of  producing  bright  figures 
upon  dark  grounds,  are  explained  in  the  article  Calico-printing  ;  but  the  peculiarities 
of  the  BandauHa  printing  may  be  conveniently  introduced  here.  In  Brande's  Journal 
for  July,  1823, 1  described  the  Bandanna  gallery  of  Messrs.  Monteith  at  Glasgow, 
which,  when  in  full  action  some  years  ago,  might  be  reckoned. the  most  magnificent  and 
profitable  printing  apartment  in  the  world.  The  white  spots  were  produced  by  a  so- 
lution of  chlorine,  made  to  percolate  down  through  the  Turkey  red  cotton  cloth,  is 
certain  points  defined  and  circumscribed  by  the  pressure  of  hollow  lead  types  in  plates^ 
in  a  hydraulic  press.  Fig.  106 is  an  elevation  of  one  press;  A,  the  top  or  entablature; 
B  B,  the  cheeks  or  pillars ;  C,  the  upper  block  for  fastening  the  upper  lead  perforated 
pattern  to ;  D,  the  lower  block  to  which  the  fellow  pattern  is  affixed,  and  which  moves 
up  and  down  with  the  piston  of  the  press ;  E,  the  piston  or  ram ;  F,  the  sole  or 
base ;  G,  the  water-trough,  for  the  discharged  or  spotted  calico  to  fall  into ;  H,  the 
small  cistern,  for  the  aqueous  chlorine  or  liquor-meter,  with  glass  tubes  for  indicating 
the  height  of  liquor  inside  of  the  cistern ;  e  e,  glass  stopcocks,  for  admitting  the  liquor 
into  that  cistern  from  the  general  reservoir;  //,  stopcocks  for  admitting  water  to  wash 
out  the  chlorine ;  g  g,  the  pattern  lead- plates,  with  screws  for  setting  the  patterns  parallel 
to  each  other;  m  m,  projecting  angular  pieces  at  each  corner,  perforated  with  a  half- inch 
hole  to  receive  the  four  guide-pins  rising  from  the  lower  plate,  which  serve  to  secure 
accuracy  of  adjustment  between  the  two  faces  of  the  lead  pattern  plates ;  h  h,  two  rollers 
which  seize  and  pull  through  the  discharged  pieces,  and  deliver  them  into  the  water- 
trough.  To  the  left  of  D  there  is  a  stopcock  for  filling  the  trough  with  water;  2,  is  the 
waste  lube  for  chlorine  I'quor  and  water  of  washing.  The  contrivance  for  blowing  a 
Stream  of  air  across  the  cloth,  through  the  pattern  tubes,  is  not  represented  in  the  figure- 


I! 


(1 1 1 


M 


nil 


■1  ! 


120 


BANDANNA. 


Sxteen  engines  similar  to  the  above,  each  possessing  the  power  of  pressing  vnik 
several  hundred  tons,  are  arranged  in  one  line,  in  subdivisions  of  four ;  the  spaces 

]0« 


between  each  subdivision  serving  as  passages  to  allow  the  workmen  to  go  readily 
flx)m  the  front  to  the  back  of  the  presses.  Each  occupies  twenty-five  feet,  so  that  the 
total  length  of  the  apartment  is  100  feet. 

To  each  press  is  attached  a  pair  of  patterns  in  lead,  (or  plates,  as  they  are  called,)  the 
manner  of  forming  which  will  be  described  in  the  sequel.  One  of  these  plates  is  fixed 
to  the  upper  block  of  the  press.  This  block  is  so  contrived,  that  it  rests  upon  a  kind  of 
universal  joint,  which  enables  this  plate  to  apply  more  exactly  to  the  under  fellow- 
plate.  The  latter  Bits  on  the  moveable  part  of  the  press,  conmionly  called  the  sill. 
When  this  is  forced  up,  the  two  patterns  close  on  each  other  very  nicely,  by  means  of 
the  guide-pins  at  the  corners,  which  are  fitted  with  the  utmost  care. 

The  power  which  impels  this  great  hydrostatic  range  is  placed  in  a  separate  apart- 
ment,  called  the  machinery  room.  This  machinery  consists  of  two  press  cylinders 
of  a  peculiar  construction,  having  solid  rams  accurately  fitted  to  them.  To  each  of 
these  cylinders,  three  little  force-pumps,  worked  by  a  steam-engine,  are  connected. 

The  piston  of  the  large  cylinder  is  eight  inches  in  diameter,  and  is  loaded  with  a 
top-weight  of  five  tons.  This  piston  can  be  made  to  rise  about  two  feet  through  a 
leather  stuffing  or  collar.  The  other  cylinder  has  a  piston  of  only  one  inch  in  diameter, 
which  is  also  loaded  with  a  top-weight  of  five  tons.  It  is  capable,  like  the  other,  of 
being  raised  two  feet  through  its  collar. 

Supposing  the  pistons  to  be  a  their  lowest  point,  four  of  the  six  small  force-pumps 
are  put  in  action  by  the  steam-engine,  two  of  them  to  raise  the  large  piston,  and  two 
the  little  one.  In  a  short  time,  so  much  water  is  injected  into  the  cylinders,  that 
the  loaded  pistons  have  arrived  at  their  his;hest  points.  They  are  now  ready  for 
working  the  hydrostatic  discharge-presses,  the  water  pressure  being  conveyed  from 
the  one  apartment  to  the  other,  under  ground,  through  strong  copper  tubes,  of  small 
ealibre. 

Two  valves  are  attached  to  each  press,  one  opening  a  communication  between  the  lai^ 


■«l 


BANDANNA. 


121 


T  j«,  «r  tiio  nrp<5«?  the  other  between  the  small  driving-cylin- 
driving^jylinder  and  t^e  cylrnder  oi  the  P'^f  ?/^^^^^^^      y^  ^le  under-block  of  the  press 

der  and  the  press.  The  f^"^^'?  ^^^^^  „^ffhe  secS  to  give  the  requisite  compression 
into  contact  w.th  the  upper-block ;  that  ^^^he  ^^"°7  ^^^  purpose  of  discharging  the 
to  the  cloth.     A  thurd  valve  is  attached  to  the  Press,  lor  i      P^  ^^  ^^ 

water  from  its  cylinder,  when  the  press  is  to  be  relaxed,  in  oraer  xo 

"^FrcSS  \wefrto  fourteen  pieces  of  cloth,  previously  dyed  T-^ey-^^^^^^^^^ 

over  rchTher,  as  parallel  as  possible,  ^Y  a  particular  m-^^^^^    These  P^^^^^  ^^^^^^^^^ 

then  rolled  round  a  wooden  cylinder  ^^f .^ij^  *^^^^^^  of  the  foiiteen  lay- 

now  placed  in  its  proper  situation  at  the  back  oVt^rnwnthrouih  between  them,  by  hix>ks 

f»rs  of  cloth  equal  to  the  area  of  the  plates,  is  next  drawn  througn  t>«^een  i        ,3 

auachfdt'the  two  corners  of  the  -bs    ^n  open  ng  the  vv    eonne^^   .^^^^^^ 

inph  drivin<'-cylinder,  the  water  enters  the  cylmder  of  the  press,  ana  ins'^"">  ,      . 

The  Xuve  force  here  will,  therefore,  be  5  tons  X  8.=320  tous ,  the  ^^  of  c^^nd^e« 
ie"ng  to  each  other,  as  the  sqaares  of  their  respecUve  d'^'°»'«,'^-The  cloth  .s  thus  con 
densrf  between  the  leaden  pattern-plates  with  a  pressure  of  320  tons,  in  a  couple  ci 

"Tt^'e7t\S;!t?o\Zi??h"/bCrng  ^-discha^in.  li,u„r  (a,„eo«s  chlorine  oh. 

on  the  pipes  and  cisterns  containing  this  liquor  are  all  ^^^^^^^  ^Jf^^^,,  ^_  :_  theuoDer 
From  the  measure-cUtem  H,  the  liquor  is  allowed  to  flow  into  the  hollows  mine  upper 
lea^Xe  wS^n^e'nScends  on  the  cloth,  and  percolates  through  it,  extracting  m  its  pas- 
sa^eTh^T^key^^^^^^  The  liriuor  is  finally  conveyed  into  the  waste  pipe,  from  a  groove 

infheundeT  block  As  soon  as  the  chlorine  liquor  has  passed  through,  water  is  admit- 
^d  in  a  similar  manner,  to  wash  away  the  chlorine ;  othenvise,  upon  ^^^^^^^^^^^ 
sure  the  outline  of  the  figure  discharged  would  become  ragged.  .  The  passage  ol  inecus- 
rar'4  liquor  as  well  as  of  the  water^hrough  the  cloth,  is  occasionally  aided  by  a  Pneu- 
mat'c  apparatus,  or  blowing  machine;  consisting  of  a  large  gasometer,  from  which  wr 
^uS  to  a  moderate  pressure  may  be  allowed  to  f-'^^^^^^^l^^^^^^^^  1^^! 
liquid  upon  the  folds  of  the  cloth.  By  an  occasional  twist  of  the  a.r  stopcock  the  worK 
man  also  can  ensure  the  equal  distribution  of  the  discharging  liquor,  oy.^' the  whole  ex- 
Stvations  in  the  upper  plate.  When  the  demand  for  goods  is  very  brisk,  the  air  appara- 
tus  is  much  employed,  as  it  enables  the  workman  to  double  his  Product. 

The  time  requisite  for  completing  the  discharging  process  in  the  first  press  is  sum- 
cient  to  enable  the  other  three  workmen  to  put  the  remaining  fifteen  presses  m  Play-  i  he 
dischar-er  proceeds  now  from  press  to  press,  admits  the  liquor,  the  air,  and  the  water, 
and  is  followed  at  a  proper  interval  by  the  assistants,  who  relax  the  press,  move  forwards 
anothe  quire  of  the  clSth,  and  then  restore  the  pressure.  Whenever  the  sixteenth  press 
has  been  iquored,  &c.,  it  is  time  to  open  the  first  press.  In  this  routme,  about  ten  mm- 
uSs  are  employed;  thkt  is,  224  handkerchiefs  (16+14)  are  discharged  every. ten  mmut^. 
The  whole  cloth  is  drawn  successively  forward,  to  be  successively  treated  in  the  above 

""when  the  cloth  escapes  from  the  press,  it  is  passed  between  the  two  rollers  in  f[ont|from 
which  it  falls  into  a  trough  of  water  placed  below.  It  is  finally  carried  off  to  the  wash- 
ing and  bleaching  department,  where  the  lustre  of  both  the  white  and  the  red  is  con- 
siderably brightened.  .  .  .  -,-  ,  ^^,  loonft 
By  the  above  arrangement  of  presses,  1600  pieces,  consisting  of  12  yards  each=19,200 
yards,  are  converted  into  Bandannas  in  the  space  of  ten  hours,  by  the  labor  ol  lour 

"^Th^  patterns,  or  plates,  which  are  put  into  the  presses  to  determine  the  white  figures 
on  the  cloth,  are  made  of  lead  in  the  following  way.  A  trelUs  frame  of  cast  iron,  one 
inch  thick,  with  turned-up  edges,  forming  a  trough  rather  larger  than  the  intended  lead 
pattern,  is  used  as  the  solid  ground-work.  Into  this  trough,  a  lead  plate  about  one  nail 
inch  thick,  is  firmly  fixed  bv  screw  nails  passing  up  fVom  below.  To  the  e;  gesof  this  lead 
plate,  the  borders  of  the  piece  of  sheet-lead  are  soldered,  which  covers  the  whole  outer 
surface  of  the  iron  frame.  Thus  a  strong  trough  is  formed,  one  inch  deep.  1  ne  "Pn?M 
border  gives  at  once  great  strength  to  the  plate,  and  serves  to  confine  the  liquor.  A  inm 
sheet  of  lead  is  now  laid  on  the  thick  lead-plate,  in  the  manner  of  a  veneer  on  toUet- 
tables,and  is  soldered  to  it  round  tfie  edges.  Both  sheets  must  be  made  very  smo^Hh 
beforehand,  by  hammering  them  on  a  smooth  stone  table,  and  then  finishing  with  a  plane: 
the  surface  of  the  thin  sheet  (now  attached)  is  to  be  covered  with  drawing  paper,  pasleU 


i 


122 


BARYTA. 


II 


on,  and  npon  this  the  pattern  is  drawn.  It  is  now  ready  for  the  ctitter.  The  first 
thing  which  he-does  is  to  fix  down  with  brass  pins  all  the  parts  of  the  pattern  which 
are  to  be  left  solid.  Ue  now  proceeds  with  the  little  tools  generally  used  by  block- 
cutters,  which  are  fitted  to  the  different  curvatures  of  the  pattern,  and  he  cuts  per- 
pendicularly quite  through  the  thin  sheet  The  pieces  thus  detached  are  easily  lifted 
out;  and  thus  the  channels  are  formed  which  design  the  white  figures  on  the  red  cloth. 
At  the  bottom  of  the  channels,  a  sufficient  number  of  small  perforations  are  made 
through  the  thicker  sheet  of  lead,  so  that  the  discharging  liquor  may  have  free  ingress 
and  egress.  Thus,  one  plate  is  finished,  from  which  an  impression  is  to  be  taken  by 
means  of  printers'  ink,  on  the  paper  pasted  upon  another  plate.  The  impression  is  taken 
in  the  hydrostatic  press.  Each  pair  of  plates  constitutes  a  set,  which  may  be  put  into 
the  presses,  and  removed  at  pleasure. 

BARBERRY.  The  root  of  this  plant  contains  a  yellow  coloring  matter,  which  is 
soluble  in  water  and  alcohol,  and  is  rendered  brown  by  alkalis,  the  solution  is  em- 
ployed in  the  manufacture  of  Morocco  leather. 

BARILLA  A  crude  soda,  procured  by  the  incineration  of  the  salsola  soda,  a  plant 
cultivated  for  this  purpose  in  Spain,  Sicily,  Sardinia,  <tc.  Good  barilla  usually  con- 
tains, according  to  my  analysis,  20  per  cent,  of  real  alkali,  associated  with  muriates 
and  sulphates,  chiefly  of  soda,  some  lime,  and  alumina,  with  very  little  sulphur. 
Caustic  leys  made  from  it  were  used  in  the  finishing  process  of  the  hard  soap  manufacture. 
^  The  quantity  of  barilla  and  alkali  imported  in  1850  amounted  to  34,880  cwts.,  and 
in  1851  to  45,740  cwts.  The  quantity  of  soda  exported  in  1850  was  827,403  cwts., 
and  m  1851,  839,183  cwt. ;  the  declared  value  being  respectively  376,351/.,  and  360,566/. 
There  is  no  duty  on  barilla. 

BARIUM,     the  metallic  basis  of  Baryta. 

BARK,  the  outer  rind  of  plants.  Many  varieties  of  barks  are  known  to  commerce, 
but  the  terai  is  commonly  used  to  express  either  Peruvian  or  Jesuits'  bark,  a  most  valua- 
ble pharmaceutical  remedy,  or  Oak  bark,  which  is  very  extensively  used  by  tanners  and 
dyers.  The  quantity  of  this  article  imported  for  the  use  of  the  latter  amounted  in  1850  to 
380,674  cwts.,  and  m  1 851  to  460,895  cwts.     The  duty  on  bark  has  been  repealed. 

BARLEY.  {Orffe,  Fr. ;  Gerste,  Germ.)  English  barley  is  that  with  two-rowed  ears, 
or  the  kordeum  vulgare  distichon  of  the  botanists ;  the  Scotch  beer  or  bigg  is  the  hordeuin 
vulgare  hexastichon.  The  latter  has  two  rows  of  ears,  but  3  corns  come  from  the  same 
point,  so  that  it  seems  to  be  six-eared.  The  grains  of  bigg  are  smaller  than  those  of 
barley,  and  the  husks  thinner.  The  specific  gravity  of  English  barley  varies  from  1-25 
to  1-33 ;  of  bigg  from  1  227  to  1  -265 ;  the  weight  of  the  husk  of  barley  is  one-sixth,  that 
of  bigg  two-ninths.  1000  parts  of  barley  flour  contain,  according  to  Einhof,  720  of  starch, 
5f  sugar,  50  mucilage,  366  gluten,  12*3  vegetable  albumen,  100  water,  25  phosphate  of 
lime,  68  fibrous  or  ligneous  matter.  Sp.  gravity  of  barley  is  1-235  by  my  trials. 
BARM.  The  yeasty  top  of  fermenting  beer.  See  Beer,  Distillation,  Fermentation. 
BARYTA  or  BARYTES,  one  of  the  simple  earths.  It  may  be  obtained  most  easily 
by  dissolving  the  native  carbonate  of  barytes  (Witherite)  in  nitric  acid,  evaporating 
the  neutral  nitrate  till  crystals  be  formed,  draining  and  then  calcining  these,  by  suc- 
cessive portions,  in  a  covered  platina  crucible,  at  a  bright  red  heat.  A  less  pure  bar3'ta 
may  be  obtained  by  igniting  strongly  a  mixture  of  the  carbonate  and  charcoal,  both  in 
fine  powder  and  moistened.  It  is  a  grayish  white  earthy  looking  substance,  fusible  only 
at  the  jet  of  the  oxy-hydrogen  blowpipe,  has  a  sharp  caustic  taste,  corrodes  the  tongue 
and  all  animal  matter,  is  poisonous  even  in  small  quantities,  has  a  very  powerful  alkaline 
reaction;  a  specific  gravity  of  4-Q;  becomes  hot,  and  slakes  violently  when  sprinkled 
with  water,  falling  into  a  fine  white  powder,  called  the  hydrate  of  baryta,  which  contains 
lOi  per  cent,  of  water,  and  dissolves  in  10  parts  of  boiling  water.  This  solution  lets  fall 
abundant  columnar  crystals  of  liydi-ate  of  baryta  as  it  cools ;  but  it  still  retains  one-twen 
tieth  its  weight  of  baryta,  and  is  called  baryta  water.  The  above  crystals  contain  61  per 
cent,  of  water,  of  which,  by  drying,  they  lose  50  parts.  Tliis  hydrate  may  be  fused  at  a 
red  heat  without  losing  any  more  water.  Of  all  the  bases,  baryta  has  the  strongest  aflin- 
ity  for  sulphuric  acid,  and  is  hence  employed  either  in  the  state  of  the  above  water,  or 
in  that  of  one  of  its  neutral  salts,  as  the  nitrate  or  muriate,  to  detect  the  presence  and 
determine  the  quantity  of  that  acid  present  in  any  soluble  compound.  Its  prime  equiva- 
lent is  7*66,  hydrogen  being  1,000.  Native  sulphate  of  baryta,  or  heavy  spar,  is  fraudu- 
lently used  to  adulterate  white  lead  by  the  English  dealers  to  a  shameful  extent. 

BASSORINE.  A  constituent  part  of  a  species  of  gum  which  comes  from  Bassora, 
as  also  of  gum  tragacanth,  and  of  some  gum  resins.  It  is  semi-transparent,  difficult 
to  pulverize,  swells  considerably  in  cold  or  boiling  water,  and  forms  a  thick  mucilage 
without  dissolving.  Treated  with  ten  times  its  weight  of  nitric  acid,  it  affords  nearly 
23  per  cent  of  its  weight  of  mucic  acid,  being  much  more  than  is  obtainable  from  gum 
arable  or  cherry-tree  gum.  Bassorine  is  very  soluble  in  water  slightly  acidulated 
with  nitric  or  muriatic  acid.  This  principle  is  procured  by  soaking  gum  Bassora  in  a 
great  quantity  of  cold  water,  and  in  removing,  by  a  filter,  all  the  soluble  parts. 


BATHS. 


123 


BATHS      {BaifiB.  Fr. ;  Baden,  Germ.)     Warm  baths  have  lately  come  into  very 

15Ain».     V^«*/f^  j'^  '  ^        Considered  as  indispensably  necessary  in  all  modern 

ru:ef  o^a.; V  ISe  C  trduthouses,  hot^els.  an/hospitals.'  But  the  mode 

'^^:i:^^  baths,  and  of  obtaining  the  ---^Y/^PP^-^.^J,  ^^^^^^^^^^ 

water,  does  not  appear  to  have  undergone  an  improvement  equal  to  the  extension  of 

their  employment 

The  several  points  in  regard  to  warm  baths,  are,  ^      ^  , 

1.  The  materials  of  which  they  are  constructed. 

2.  Their  situation. 

8.  The  supply  of  cold  water. 

4.  The  supply  of  hot  water. 

5.  Minor  comforts  and  conveniences.  ,     i.     ^  i  v 
1    As  to  the  materials  of  which  they  are  constructed.— Of  these  the  best  are  slabs 

of  polished  marble,  properly  bedded  with  good  water-tight  cement,  in  a  seasoned 
wooden  case,  and  neatly  andf  carefully  united  at  their  respective  edges.  These,  when 
oricinallv  well  constructed,  form  a  durable,  pleasant,  and  agreeable-looking  bath; 
but  the  expense  is  often  objectionable,  and,  in  upper  chambers,  the  weight  may  prove 
inconvenient  If  of  white  or  veined  marble,  they  are  also  apt  to  get  yellow  or  dis- 
colored by  frequent  use,  and  cannot  easily  be  cleansed ;  so  that  large  Dutch  tiles,  as 
thev  are  called,  or  square  pieces  of  white  earthenware,  are  sometimes  substituted; 
which,  however,  are  difficultly  kept  water-tight;  so  tl.at,  upon  the  whole,  raaible  is 
preferkble.     Welsh  slate  has  now  superseded  marble  to  a  great  extent. 

Where  there  are  reasons  for  excluding  marble,  copper,  tinned,  or  galvanized  iron  is 
the  usual  material  resorted  to.     The  first  is  most  expensive  m  the  outfit,  but  far  more 
durable  than  the  latter,  which  are,  moreover,  liable  to  leakage  at  the  joints  unless 
most  carefully  made.     Either  the  one  or  the  other  should  be  well  covered  outside  and 
inside  with  several  coatsof  paint,  which  may  then  be  marbled  or  otherwise  ornamented 
Wooden  tubs,  square  or  obiong,  and  oval,  are  sometimes  used  for  warm  baths;  and 
are  cheap  and  convenient,  but  neither  elegant  nor  cleanly.     The  wood  always  con- 
tracts a  mouldy  smell ;  and  the  difticulty  and  nuisance  of  keeping  them  water-tight, 
and  preventing  shrinkage,  are  such  as  to  exclude  them  from  all  except  extemporane- 
ous application.  .        ,  •  i    •.  •    *    i  ^ 
2.  As  to  the  situation  of  the  bath,  or  the  part  of  the  house  in  which  it  is  to  be 
placed.— In  hotels  and  club-houses  this  is  a  question  easily  determined :  several  baths 
are  usually  here  required,  and  each  should  have  annexed  to  it  a  properly  warmed 
dressing-room.     Whether  they  are  up  stairs  or  down  stairs  is  a  question  of  conveni- 
ence, but  the  basement  stoiy,  in  which  they  are  sometimes  placed,  should  always  be 
avoided:  there  is  a  coldness  and  dampness  belonging  to  it,  in  almost  all  weathei-s, 
which  13  neither  agreeable  nor  salubrious. 

In  hospitals,  there  should  be  at  least  two  or  three  baths  on  each  side  of  the  house 
(the  men's  and  women's),  and  the  supply  of  hot  water  should  be  ready  at  a  momeut's 
notice.  The  rooms  in  which  the  baths  are  placed  should  be  light,  and  comparatively 
large  and  airy ;  and  such  conveniences  for  getting  into  and  out  of  the  baths  should  be 
adopted  as  the  sick  are  well  known  to  require.  The  dimensions  of  these  baths  should 
also  be  larger  than  usual. 

In  private  houses',  the  fittest  places  for  warm  baths  are  dressing-rooms  annexed  to 
the  principal  bed-rooms ;  or,  where  such  convenience  cannot  be  obtained,  a  separate 
bath-room,  connected  with  the  dressing-room,  and  always  upon  the  bed-room  floor. 
All  newly-buill  liouses  should  be  properly  arranged  for  this  purpose,  and  due  attention 
should  be  paid  to  the  warming  of  the  bath-room,  which  ought  also  to  be  properly  ven- 
tilated. A  temperature  of  70°  may  be  easily  kept  up  in  it,  and  sufficient  ventilation 
is  absolutely  requisite  to  prevent  the  deposition  of  moisture  upon  the  walls  and  furni- 
ture. ,   . 

The  objection  which  formerly  prevailed,  in  respect  to  the  difficulty  of  obtaining  ade- 
quate supplies  of  water,  in  the  upper  rooms,  has  been  entirely  obviated  by  having  cis- 
terns at  or  near  the  top  of  the  house  ;  and  we  would  just  hint  that  these  should  be  so 
contiived  as  to  be  placed  out  of  the  reach  of  frost ;  a  provision  of  the  utmost  import- 
ance in  every  point  of  view,  and  very  easily. effected  in  a  newly-built  house,  though  it 
unfortunately  hap[»en8  that  architects  usually  regard  these  matteis  as  trifles,  and  treat 
them  with  neglect.as  indeed  they  do  the  warming  and  ventilation  of  buildings  generally. 
3.  The  supply  of  water  of  proper  quality  and  quantity  is  a  very  important  point, 
as  connected  with  the  present  subject.  The  water  should  be  soft,  clean,  and  pure,  and 
as  free  as  possible  from  all  substances  mechanically  suspended  in  it  In  many  cases 
it  answei*s  to  dig  a  well  for  the  exclusive  supply  of  a  large  house  with  water.  In  most 
I  arts  of  London  this  may  effectually  be  accomplished  at  a  comparatively  moderate  ex- 
peme;  and,  if  the  well  be  deep  enough,  the  water  will  be  abundant,  soft,  and  pellucid. 
The  labor  of  forcing  it  by  a  pump  to  the  top  of  the  house  is  the  only  drawback ;  this* 


lii 


124 


BATHS. 


however  is  very  easily  done  by  a  horse-engine,  or  there  are  people  enongh  about 
^rSlfi^"^  o  undertake  it  at  a  shilling  a  day.^  I  am  led  to  these  remarks  byXerWn^ 
.the  filthy  state  of  the  water  usually  supplied,  at  very  extravagant  rates,  b/the  wltef 
companies.  It  deposits  its  nastiness  in  the  pipes  connected  with  warm  baths  and 
throws  down  a  shppery  deposit  upon  the  bottom  of  the  vessel  itself,  to  such  an  ektent 

^«1W  f  ^''r?''^!'^^  '^^  ^^'"g  "«^^  *^  ^^^«^  ««  *  1"^»7.  which  a  clear  and  clean  bath 
reaiiy  is.  ihis  inconvenience  may,  m  some  measure,  be  avoided  by  sufferine  the 
water  to  throw  down  its  extraneous  matters  upon  the  bottom  of  the  cistei-n    and 

ortZn """"  -f  PP.i''  ^■'''^  Py^^'  *,^^"^^  ^^^^^  '^  5  there  will,  however,  always  be  more 
ihl^^T"  ^?.*^^P'P««  themselves,  and  every  time  the  water  runs  into  the  cistern 
the  grouts  are  stirred  up  and  diffused  through  its  mass. 

n.t\Tr,^-^T\l  ^"^""5  Y^'^l^  establishments,  where  numerous  and  constant  baths 
are  required,  the  simplest  and  most  effective  means  of  obtaining  hot  water  for  their 
supply  consists  m  drawing  it  directly  into  the  baths  from  a  large  boiler  placed  some- 
where above  their  level  This  boiler  should  be  supplied  with^roper  VSnlp' pes 
and  gauges;  and,  above  all  things,  its  dimensions  should  be  ample;  it  shoullfe  of 
wrought  iron  or  copper.  The  hot  water  should  enter  the  bath  by  a  pipe  at  lei^t  an 
in^    «^\^h*lf »"  d^^^etev;  and  the  cold  water  by  one  of  the  same^d^mension^  or 

Zrof  leTor'  ^V' n'^%^^'^  °^^^.  ""'  ^'  ^^"^  ^"  fi"^«?-  The  relative  propoi^' 
everv  hn  h  «hn.l  fl  ^^'^^^^^er  are,  of  course,  to  be  adjusteS  by  a  thermometer,  and 
of  the  Wh  ^A  ^^"^^  ^  Ir"'"''^  waste-pipe,  opening  about  two  inches  from  the  top 
of  the  bath,  and  suffering  the  excess  of  water  freely  to  run  off;  so  that  when  a  person 
^immersed  m  the  bath,  or  when  the  supplies  of  witer  are  accidentally  lift  openf  tTere 
m^  be  no  dan^^er  of  an  overflow.  "^         ^     ' 

fnr!i^  r*^^""^  '^  ^  ^^"""^P.  '"^  *^^  ''PP*'^  «*^^3'  of  the  house,  or  other  convenient  place 
^nn  w  ff  *  ««PPf  r  a?d  its  appurtenances,  a  plan  similar  to  the  above  may  often  be 
conveniently  adopted  in  private  houses,  for  the  supply  of  a  bath  upon  the  principal 
bed-room  floor.  An  attempt  is  sometimes  made  to  plice  boilers  behind  th^  fires  of 
dressing-rooms,  or  otherwise  to  erect  them  in  the  room  itself,  for  the  purpose  of  supply, 
wg  warm  water ;  but  this  plan  is  always  objectionable  from  the  complexity  of  tfie 

from  th.V  l^  '^'  '"Pf^^  I^^V"'*  ^^  ^"^"'^^^^^  *«  '^'  ^i'^'-'  ««^  «ft^^  da^ngerous 
from  the  flues  becoming  choked  with  soot  and  taking  fire.     Steam  is  also  apt,  in  such 

cases,  to  escape  m  quantities  into  the  room ;  so  that  it  becomes  necessary  to  search  f.)r 

riiaTdTsti-ibe'  '  """^  '*''  ^^"^  ""^  ^^^  ^^^^^  objectionable  of  which  I 

«f  IV-^  t  ^?"^"^^"««  of  some  ingenuity  consists  in  suffering  the  water  for  the  supply 
of  the  bath  to  flow  from  a  cistern  above  it,  through  a  leaden  pipe  of  about  one  inch 
diameter,  which  is  conducted  into  the  kitchen  or  other  convenient  place,  where  a  large 
boiler  for  the  supply  of  hot  water  is  required.  Tlie  bath-pipe  is  imnTersed  in  this  boiler 
m  which  it  makes  many  convolutions,  and,  again  emerging,  ascends  to  the  bath.  The 
operation  is  simply  this :— the  cold  water  passing  through  the  convolutions  of  that 
part  of  the  pipe  which  is  immersed  in  the  boiling  water,  receives  there  sufficient  heat 
for  the  purpose  required,  and  is  delivered  in  that  state  by  the  ascending  pipe  into  the 
bath  which  IS  also  supphed  with  cold  water  and  waste-pipes  as  usual.  The  pipe  may 
be  ot  lead,  as  far  as  the  descending  and  ascending  parts  are  concerned,  but  the  por- 
tion formmg  the  worm  or  convolutions  immersed  in  the  boiler  should  be  copper  in 
order  that  the  water  within  it  may  receive  heat  without  impediment  ' 

Ihis  plan  is  economical  only  where  a  large  boiler  is  constantly  kept  at  work  in  the 
lower  part  of  the  house ;  otherwise  the  trouble  and  expense  of  heating  such  a  boiler 
for  the  mere  purpose  of  the  bath,  render  it  unavailable.  The  worm-pipe  is  also  apt  to 
become  furred  upon  the  outside  by  the  deposition  of  the  earthy  impurTties  of  the  water 
m  which  It  18  immersed;  it  then  becomes  a  bad  conductor  of  heat,  is  cleansed  with 
ditticulty,  and  the  plan  is  rendered  ineffective.  This  system,  however,  has  been  adopted, 
m  some  particular  cases,  with  satisfaction. 

V  1?'\  ^  °i"^^  i"®''1  simple,  economical,  and  independent  mode  of  heating  a  warm 
bath,  by  a  fire  placed  at  a  distance  from  it,  is  the  following,  which  is  found  to  answer 
pertectly  111  private  houses,  as  well  as  upon  a  more  extended  scale  in  large  establish- 
ments. It  18  certainly  open  to  some  objections,  but  these  are  overbalanced  by  its  ad- 
vantages. A  wagon-shaped  boiler,  holding  about  six  gallons  of  water,  is  properly 
placed  over  a  small  furnace  in  any  convenient  and  safe  part  of  the  house,  as  the  kitchen 
scullery,  servants'  hall,  or  wash-house.  The  bath  itself,  of  the  usual  dimensions  and 
construction,  is  placed  where  it  is  wanted,  with  a  due  supply  of  cold  water  from  above 
Two  pipes  issue  from  within  an  inch  of  the  bottom  of  the  bath  at  its  opposite  extremi^ 
ties;  one  at  the  head  of  the  bath,  about  one  inch,  and  the  other  at  the  foot  an  inch 
and  one-eighth  in  diameter.  These  tubes  descend  to  the  boiler,  the  smaller  one  enter- 
ing it  at  the  bottom,  and  the  larger  one  issuing  from  its  top. 

Under  these  circumstances,  supposing  the  pipes  and  boiler  everywhere  perfectly 
tight^  when  the  bath  is  filled,  the  water  will  descend  into  and  expel  the  air  from  the 


I 


I 


f 


I 


BATHS. 


125 


boiler,  and  compleUly  fill  it    ^^^  JlP^^.^a^i^^^ 

ascending  current  of  wai-m  ^^^er  wi  1  necessaa^  S^enSby  the  pipe  which  enter* 
pipe  which  issues  from  its  t«P' ^^f  .^^^f.  T^^'^t  J/ em^^^^^^^^^^  tL  whole  mass  of  water 
^1  tt^^rriiiretrkLC^^^^^^^^^  o.  if'above  i.  the  temperature 

"^  i^i::^rgroMht^fo^^  «^oi^/  r '''-'  ^'  ^^t 

for  heatiig  the  bath;  the  water  in  which  may.  if  require,  be  raised  to  about  100  m 
Ibout  half  au  hour  f;om  the  time  of  lighting  the  fire.     The  consumption  of  fuel  is  also 

^"Tire^fbllowing  are  the  chief  disadvantages  attendant  upon  this  plan,  and  the  means 

^'^f  i^'necfsstTwi^en  the  water  has  acquired  its  proper  temperature,  to  arrest  the 
circurat^onTf  the  water  by  means  of  a  stopcock  or  valve  adjoining  the  boiler ;  the  next 
resource  is  to  withdraw  the  fire  from  the  boiler,  or  not  to  use  the  bath  immediately . 
wTmay  go  on  acquiring  some  heat  from  the  boiler,  so  that  we  may  become  mcon- 
^eiiently  hot  in  the  bath  When,  therefore,  this  bath  is  used^  we  may  proceed  as  fol- 
Tows  -Seat  the  water  in  it  an  hour  before  it  is  wanted,  to  about  100°,  and  then  ex- 
tinguish the  fire.  The  water  will  retain  its  temperature,  or  nearly  so,  for  three  or 
fou?  hours,  especially  if  the  bath  be  shut  up  with  a  cover;  so  that  when  about  to  use 
itcold  water  may  be  admitted  till  the  temperature  is  lowered  to  the  required  point, 
and  thus  all  the  above  inconveniences  are  avoided.  ^      ,    •  ;i^  ,  «^^» 

Another  disadvantage  of  this  bath  arises  from  too  fierce  a  fire  being  made  under 
the  boiler,  so  as  to  occasion  the  water  to  boil  within  it,  a  circunistance  which  ought  al- 
ways to  be  carefully  avoided.  In  that  case,  the  steam  rising  in  the  upper  part  of  the 
boiler  and  into  the  top  pipe,  condenses  there,  and  occasions  violent  concussions,  the 
noise  of  which  often  alarms  the  whole  house,  and  leads  to  apprehensions  of  explosion, 
which,  however,  is  very  unlikely  to  occur;  but  the  concussions  thus  produced  injure 
the  pipes,  and  may  renaer  them  leaky ;  so  that  in  regain!  to  these,  and  all  other  baths 
Ac,  we  may  remark,  that  the  pipes  should  pass  up  and  down  in  s^^b  parts  of  the  house 
as  will  not  be  injured  if  some  leakage  takes  place;  and  under  the  bath  itself  should 
be  a  sufficiently  large  leaden  tray  with  a  waste-pipe,  to  receive  and  carry  off  any  ac- 
cidental  drippings,  which  might  injure  the  ceilings  of  the  rooms  below.  In  aU  newly- 
built  houses,  two  or  three  flues  should  be  left  in  proper  places  for  the  passage  of  asn 
cending  and  descending  water-pipes;  and  these  flues  should  in  some  way  receive  at 
their  lower  part  a  little  warm  air  in  winter,  to  prevent  the  pipes  freezing;  the  same 
attention  should  also  be  paid  to  the  situation  of  the  cisterns  of  water  m  houses,  which 
should  be  kept  within  the  house,  and  always  supplied  with  a  very  ample  waste-pipe, 
to  prevent  the  danger  of  overflow.  Cisterns  thus  properly  placed,  and  carefully  con- 
structed, should  be  supplied  from  the  water-mains  by  pipes  kept  under  ground,  till 
they  enter  the  house,  and  not  carried  across  the  area,  or  immediately  under  the  pave- 
ment where  they  are  liable  to  freeze. 

(3.)  Baths  are  sometimes  heated  by  steam,  which  has  several  advantages ;  it  may  either 
be  condensed  directly  into  the  water  of  the  bath,  or,  if  the  bath  be  of  copper  or  tinned 
iron,  it  may  be  conducted  into  a  casing  upon  its  outside,  usually  called  a  jacket;  in 
the  latter  case  there  must  be  a  proper  vent  for  the  condensed  water,  and  for  the  escape 
of  air  and  waste  steam.  Steam  is  also  sometimes  passed  through  a  serpentine  pipe, 
placed  at  the  bottom  of  the  bath.  But  none  of  these  methods  are  to  be  recommended 
for  adoption  in  private  houses,  and  are  only  advisable  in  hospitals,  or  establishments 
where  steam  boilers  are  worked  for  other  purposes  than  the  mere  heating  of  baths. 

The  French  make  much  more  use  of  hot  baths  than  we  do,  both  as  respects  health 
and  cleanliness,  a  fact  well  illustrated  by  the  following  statistics.  In  the  year  1780  the 
whole  public  bathing  establishments  in  Paris  contained  only  250  separate  baths ;  in 
1813  they  contained  300 ;  in  1832  there  were  78  houses  fitted  up  with  2374  fixed  baths, 
and  1059  movable  ones  for  transporting  to  private  houses ;  and  at  present  new  bathing 
establishments  are  being  mounted  from  day  to  day  in  the  several  quarters x)f  the  capital 
Galvanized  iron  is  now  preferred  even  to  copper  for  making  baths,  being  equally 
durable  and  greatly  cheaper.  Sulphureous  baths  are  made  of  sheet  zinc,  for  the  alka- 
line sulphurets  act  very  little  upon  that  metal.  The  forni  of  the  baths  is  usually 
made  ovoid,  because  this  shape  requires  less  water  for  immersing  the  human  body  than 
the  rectangular.  _  •  v     t    i 

Many  copper  and  tin  baths  have  been  lately  constructed  in  London,  with  a  little 
furnace  attached  to  one  end,  and  surrounded  with  a  case  or  jacket,  into  which  the  water 
flows  and  circulates  backwards  and  forwards  till  the  whole  mass  in  the  bath  gets 
heated  to  the  due  degree.    One  of  the  best  of  these  is  that  constructed  by  Mr.  Benham, 


II 


126 


BEER. 


BEER. 


127 


i| 


I 


quality  to  which  Ihirname  is  liven  ,!.^h.  '  but  there  are  many  beverages  of  inferior 
all  of  which  cons  ro?^Lchar7„e'uQat  ^Xl.v  "?"'  ^!!\°"  ^"'  "■°'«^*^'  ''''^^'  «'«• ' 
«id  flavored  with  pec uUar  ?ubTta„ces      ''^'^"''^ '»'"''«  ™°"'''«^^^^ 

narrof\\t.taTq"asrSlt^'|!iin':Th/"''  ;''^''^'"'  5"^^  "«'•'  ■"'P™P"«"= 
most  celebrated  liquor^f  thSdTn^h.'n  ,?  .'^  "  "i  'T'  ""«  «'"  "^  f^''^^-  The 
from  the  town  where  it  was  Lt™  J?  ^  .>.  "  ""u'  'J*'  ""^  J'«te«an  potaUon,  so  called 

intoxication  caused  by  Irer  '^nd  Th^'ni™  r""  ""^  •""■^""-  ^"^'""^  ^P^»''^  "t  ">« 
iarfey.    We  may,  indeed  Infer  frl!^?'-"*  7^?  J"?"y  denominated  it  the  wine  of 

go„s*t„  our  beerVe"etC  am™"  ie\„"cTnr^^^^^^^  historians,  that  drinks  anall 
people  of  our  temperate  zone ;  and'they  are  st^fJhi  '-^  f-K"** '"  ^'""■-  "''°''''  "^"^ 

Where  the  vine  is  not  an  object  of  rnstlcTusSd^'  ""'""^  ""^^'^^  '"  '^"^  "^ 

fJeLZsT-"'""  "'■  '^"' "  ""^  "'  <"■  •'^^'""S.  ""y  fe  conveniently  considered  under 
Jley'^a"nd'^"'s"""°"  "'"""  """^  productions  wtich  enter  Into  its  composiUon;  or  of 
of  mamnVand"'masWn?  '^"''  "'"^' ''"''"'°  '»  «'  "  f-  -"^-g  •-- ;  or  the  processe, 
J  S:  i?rrrtifn  V^SK"^;  r  ""=  ■-"^  "«>'  -^  "OP'- 

ferLmatv^dl'nt^rWwWc^ 

fittest.  There  are'urjpSs  of  barl^^he  Ct'  *""  /'"'  '^'  ^■"'"'"«  "  ^^  f"  '"« 
two  seeds  arranged  in  a  row  „„  Vi.       b '        T"!™'"  ««'sa«  or  common  barify,  having 

seeds  sprin,  from  one  potoTso  that  fsdoubltlwt*"'*^  he.as,ickon,  ia  whik  thref 
is  the  proper  barley,  and  is  much  th.  i,r»  ^  a  '"'^.W^ently  six  seeds.  The  former 
England,  but  is  much  cu  iva^«l  ,^%i  fF  /'"?  ^™" '  ""  '"'"  '^  «"'«  ^""^-^  in 
ha5ypli„tadaprert„rcoS  count^"'%t"fi^^^^^  i^ar  or  4,gg ;  being  a 

the  denser  and  arger  its  seed  and  ihT  .hlo.  ■?\'''*,'''™.°''' '»  "^^'"^  ^'^^  f^"""^, 
barley  is  dislinguishS  in  these  res„eit(Vo,^?h^,'%^"K^  Sutfolk 

pact  grain  thaS  barky  "  the  w5?ht  of  a  W^^^- ^  Aberdeenshire.  Bigg  is  a  less  com- 
the  former  is  only  aboL  47  IbT   ^ile  that  of  »  h    >,  ."'r'^.'^l^'''''^  '="''''=  '"'*'^^^  "^ 

^'"Tb/^riirork'ir^^^^^  p™t"iircroth~'''  ^'  '^■ 

IM  measures  of  average  English  barky  thereby  swell  into  124. 
100      _        rf    Z        S'=^<='' ditto,  .        .        j2,, 

«sSr5S,S;s5-FSs  r^.  3.  ^.,„ 

Of  course  taking  up  most  walT         '  ^    "^''''  *"  ^""^"^^^  ^^^  P^""'*^'"  '^'^*«st 

3-52  parts  of  gluten,  5.2lTs^r  4  62  0^1,1  i  of  r'  1'^^^^  coagulated  albunen, 
water.  The  loss  aiiounted  to  f  I2  Tn^hl.T'  ^'^ ^^^  Phosphate  of  lime,  and  9-37  of 
volatileoilof  a  concrete  nature  whir  Jr^^  '^°"^^  ^^  «^^^^  ^  Peculiar 

mented  malt  wash  Tie  Wmsxrvf  Tr  nl  r^^""''^  '^',  T^"^  «^  ^^^tilling  fe.-. 
solvent  action  of  alcohd ;  and  neve;^amlSo  Ir^  ZTf  ^''"^  ''"^^^^  ^'^'^  ^>  ^^« 
The  husk  also  contains  sime  ofThYt  f:ad"o^'  %fZ  ho'.ht^h'at'hfhiS  T  ^'°""."'- 
barley  a  peculiar  principle,  to  which  he  save  the  name  of  A^L^W  I  .  ^  discovered  m 
rated  from  starch  by  the  action  of  both  cold  aid^b^^g  watf^-^^;  Snd'th:'  by'  ^. 


«l 


ing  barley  meal  successively  with  water,  he  obtained  from  89  to  90  parts  of  a  farinaceous 
substance,  composed  of  from  32  to  33  of  starch,  and  from  57  to  58  othordeiite.  Emhof 
obtained  Irom  barley  seeds,  70-05  of  flour,  18-75  of  husks  or  bran,  and  11-20  of  water. 

According  to  Proust,  hordeine  is  a  yellowish  powder,  not  unlike  fine  saw-dust.  It 
contains  no  azote,  for  it  aflfords  no  ammonia  by  distillation,  and  is  therefore  very  dissimi- 
lar 10  "lut^n.  In  the  germination  of  barley,  which  constitutes  the  process  of  malting, 
the  proportion  of  hordeine  is  greatly  diminished  by  its  conversion  into  sugar  and  starch. 
Other  chemists  suppose  that  the  hordeine  of  Proust  is  merely  a  mLXture  of  the  bran  cf 
the  barley  with  starch  and  gluten.  It  is  obvious  that  the  subject  stands  in  need  of  new 
chemical  researches.  In  barley  the  husk  constitutes  from  one  fourth  to  one^  fifth  of  the 
whole  weight;  in  oats  it  constitutes  one  third;  and  in  wheat  one  tenth.  From  the  ana- 
lysis of  barley  rfuur  recently  made,  it  appears  to  consist  in  1000  parts  :  of  water,  100 ;  al- 
bumen, 22-3  ;  sugar,  56 ;  gum  or  mucilage,  50 ;  gluten,  37-6 ;  starch,  720 ;  phosphate 

of  lime,  2-5.  .         j  • 

2.  The  hop,  humulus  lujmlus,  the  female  flowers  of  the  plant.  Ives  first  directed  attention 
to  a  yellow  pulverulent  substance  which  invests  the  scales  of  the  calkins,  amounting  to 
about  one  eighth  of  their  weight ;  and  referred  to  it  the  valuable  properties  which  hops  im- 
part to  beer.  We  may  obtain  this  substance  by  drjins  the  hops  at  a  temperature  of  86° 
F.,  introducing  them  into  a  coarse  canvass  bag,  and  shaking  it  so  that  the  yellow  powder 
shall  pass  through  the  pores  of  the  canvass.  This  powder  bears  some  resemblance  to  lyco- 
podiunf.  Of  the  13  parts  in  100  of  this  powder,  4  parts  are  foreign  matters,  derived  from 
me  scales  of  the  cones ;  leaving  9  parts  of  a  peculiar  granular  substance.  When  distilled 
with  water,  this  substance  affords  two  per  cent,  of  its  weight  ( j2_  for  100  times  the 
weight  of  hops)  of  a  volatile  colorless  oil,  to  which  the  plant  owes  its  peculiar  aroma« 
This  oil  dissolves  in  water  in  considerable  quantity.  It  appears  to  contain  sulphur  (for 
it  blackens  solutions  of  silver),  and  also  acetate  of  ammonia.  No  less  than  65  per  cent, 
of  the  yellow  dust  is  soluble  in  alcohol.  This  solution,  treated  with  water  and  distilled, 
leaves  a  reein,  which  amounts  to  52-5  per  cent.  It  has  no  bitter  taste,  and  is  soluble  in 
alcohol  and  ether.  The  watery  solution  from  which  the  resin  was  separated  contains  the 
bitter  substance  which  has  been  called  lupuline  by  Payen  and  Chevallier,  mixed  with  a 
little  tannin  and  malic  acid.  To  obtain  this  in  a  state  of  purity,  the  free  acid  must  be 
saturated  with  lime,  the  solution  evaporated  to  dryness,  and  the  residuum  must  be  treated 
with  ether,  which  removes  a  little  resin ;  after  which  the  lupuline  is  dissolved  out  by  al- 
cohol, which  leaves  the  malate  of  lime.  On  evaporating  away  the  alcohol,  the  lupuline 
remains,  weighing  from  8-3  to  12-5  per  cent.  It  is  sometimes  white,  or  slightly  yel- 
lowish, and  opaque,  sometimes  orange  yellow  and  transparent.  At  ordinary  tempera- 
tures it  is  inodorous,  but  when  heated  strongly  it  emits  the  smell  of  hops.  It  possesses 
the  characteristic  taste  and  bitterness  of  the  hop.  Water  dissolves  it  only  in  the  propor- 
tion of  5  per  cent.,  but  it  thereby  acquires  a  pale  yellow  color.  Lupuline  is  neither 
acid  nor  alkaline ;  it  is  a  ited  upon  neither  by  the  dilute  acids  nor  alkalis,  nor  by  the 
solutions  of  the  metallic  salts ;  it  is  quite  soluble  in  alcohol,  but  hardly  in  ether.  It 
contains  apparently  no  azote,  for  it  affords  no  ammonia  by  destructive  distillation  ;  but 
only  an  empyrjumatic  oil. 

The  yellow  dust  of  hops  contains,  moreover,  traces  of  a  fatty  matter,  gum,  a 
small  quantity  of  an  azoiized  substance,  and  several  saline  combinations  in  minute 
quantity.  Boiling  water  dissolves  from  19  to  31  per  cent,  of  the  contents  of  the  dust,  of 
which  a  large  proportion  is  resin.  Ives  thought  that  the  scales  of  the  catkins  of  hops,  when 
freed  from  the  yellow  powder,  contained  no  principles  analogous  to  it ;  but  Payen  and 
Chevallier  have  proved  the  contrary.  The  cones  of  hop  give  up  to  boiling  alcohol  36 
per  cent,  of  soluble  matter;  while  the  same  cones,  stripped  of  their  yellow  powder,  yield 
only  26  per  cent. ;  and  further,  these  chemists  found  the  same  principles  in  the  different 
parts  of  the  hop,  but  in  diflerent  proportions. 

The  packing  of  the  hop  catkins  or  cones  is  one  of  the  most  important  operations 
towards  the  preservation  of  this  plant ;  and  is  probably  the  cause  of  the  enormous  dif- 
ference in  value  between  the  English  and  French  hops  after  a  few  years  keeping.  The 
former,  at  the  end  of  six  years,  possess  still  great  value,  and  may  be  sold  as  an  article 
only  two  or  three  years  old ;  while  the  latter  have  lost  the  greater  part  of  their  value  in 
three  years,  and  are  no  more  saleable  at  the  end  of  four.  In  France,  it  is  packed  merely 
by  tramping  it  with  the  feet  in  sacks.  Under  this  slight  pressure,  large  interslilial 
spaces  are  left  amid  the  mass  of  the  hops,  through  which  the  air  freely  circulates,  car- 
rying oft'  the  essential  oil,  and  oxygenating  some  of  the  other  proximate  principles,  so  as 
to  render  them  inert.  By  the  English  method,  on  the  contrar)',  the  hops,  after  being 
well  rammed  into  strong  sacks  hung  in  frames,  are  next  subjected  to  the  action  of  a 
hydraulic  press.  The  valuable  yellow  powder  thus  enclosed  on  every  side  by  innu- 
merable compact  scales,  is  completely  screened  from  the  contact  of  the  atmosphere,  and 
from  all  its  vicissitudes  of  humidity.  Its  essential  oil,  in  particular,  the  basis  of  its  flavor, 
is  preserved  without  decay. 


ij 


128 


BEER. 


According  to  the  experiments  of  Chevallier  and  Payen  upon  the  hops  of  England 
Fenders,  the  Netherlands,  and  the  department  of  the  Vosges,  those  of  the  county  of  Kent 
afforded  the  largest  cones,  and  were  most  productive  in  useful  secreted  and  soluble  mat- 
ters.    Next  lo  ihem  were  the  hops  of  Alost. 

The  best  hops  have  a  golden  yellow  color,  large  cones,  an  agreeable  aroma  :  when  rub- 
bod  between  the  hands,  they  leave  yellow  traces,  powerfully  odoriferous,  without  any 
broken  portions  of  the  plant,  such  as  leaves,  stems,  and  scaly  fragments.  When  alcohol 
IS  digested  on  good  hops,  from  9  to  12  per  cent,  of  soluble  yellow  matter  maybe  obtained 
by  evaporating  it  to  drjness.     Tliis  is  a  good  test  of  their  quality. 

The  best-flavored  and  palest  hops  are  packed  in  sacks  of  fine  canvass,  which  are  call- 
ed pockets,  and  weigh  about  1^  cwt.  each.  These  are  bought  by  the  ale  brewer.  The 
stronger-flavored  and  darker-colored  hops  are  packed  in  bags  of  a  very  coarse  texture 
like  door-mats,  called  hop  bags  :  these  contain  generally  about  3  cwt.,  and  are  sold  to  the 
porter  and  beer  brewers.  After  the  end  of  a  year  or  two,  hops  are  reckoned  to  have  lost 
much  of  their  marketable  value,  and  are  then  sold  lo  the  second-rate  porter  brewers,  un- 
der  the  nanie  of  old  hops.  The  finest  hops  are  grown  in  the  neighborhood  of  Canterbury : 
but  those  of  Worcester  have  an  agreeable  mildness  of  flavor,  greatly  admired  by  many 
ale  drinkers.  When  the  bitter  and  aromatic  principles  disappear,  the  hops  are  no  better 
Uian  so  much  chaff;  therefore,  an  accurate  chemical  criterion  of  their  principles  would 
be  a  great  benefit  to  the  brewer. 

U.  Malting.— This  process  consists  of  three  successive  operations:  the  steeping:  the 
couching,  sweating,  and  flooring;  and  the  kiln-drying. 

The  steeping  is  performed  in  large  cisterns  made  of  wood  or  stone,  which  being  filled 
with  clear  water  up  to  a  certain  height,  a  quantity  of  barley  is  shot  into  ihem,  and  weU 
stured  about  with  rakes.  The  good  grain  is  heavy,  and  subsides;  the  lighter  giains, 
which  float  on  the  surface,  are  damaged,  and  should  be  skmimcd  oflf;  for  they  would  in- 
jure the  quahly  of  the  malt,  and  the  flavor  of  the  beer  made  with  it.  They  seldom  amount 
to  more  than  two  per  cent.  More  barley  is  successively  emptied  into  the  steep  cistern, 
till  the  water  stands  only  a  few  inches,  about  five,  above  its  surface ;  when  this  is  levelled 
very  carefully,  and  every  light  seed  is  removed.  The  steep  lasts  from  forty  to  sixty  hours, 
according  to  circumstances;  new  barley  requiring  a  longer  period  than  old,  and  bigg  re- 
quiring much  less  time  than  barley. 

During  this  steep,  some  carbonic  acid  is  evolved  from  the  grains,  and  combines  with 
the  water,  which,  at  the  same  time,  acquires  a  yellowish  tinge,  and  a  strawy  smell,  from 
dissolving  some  of  the  extractive  matter  of  the  barley  husks.  The  grain  imbibes  about 
one  half  its  weight  of  water,  and  increases  in  size  by  about  one  fifth.  By  losing  this  ex- 
tract, the  husk  becomes  about  one  seventieth  lighter  in  weight,  and  paler  in  color. 

The  duration  of  the  steep  depends,  in  some  measure,  upon  the  temperature  of  the  air, 
and  is  shorter  in  summer  than  in  winter.  In  general  from  40  to  48  hours  will  be 
found  sufficient  for  sound  dry  grain.  Steeping  has  for  its  object  to  expand  the  farina 
ol  the  barley  with  humidity,  and  thus  prepare  the  seed  for  germination,  in  the  same  way 
as  the  moisture  of  the  earth  prepares  for  the  growth  of  the  radicle  and  plumula  in  seed 
sown  m  it.  Too  long  continuance  in  the  steep  is  injurious;  because  it  prevents  the 
germination  at  the  proper  time,  and  thereby  exhausts  a  portion  of  the  vegetative  power: 
It  causes  also  an  abstraction  of  saccharine  matter  by  the  water.  The  maceration  is  known 
to  be  complete  when  the  grain  may  be  easily  transfixed  with  a  needle,  and  is  swollen 
to  Its  full  size.  The  following  is  reckoned  a  good  test :— If  a  barley-corn,  when  pressed 
between  the  thumb  and  fingers,  continues  entire  in  its  husk,  it  is  not  suflSciently  steeped : 
but  If  It  sheds  Its  flour  upon  the  fingers,  it  is  ready.  When  the  substance  exivles  in  the 
lorm  of  a  milky  juice,  the  steep  has  been  too  long  continued,  and  the  barley  is  spoiled  foi 
germination. 

In  warm  weather  it  sometimes  happens  that  the  water  becomes  acescent  before  the 
gram  IS  thoroughly  swelled.  This  accident,  which  is  manifest  to  the  taste  and  smell, 
must  be  unmediately  obviated  by  drawing  oflf  the  foul  water  through  the  tap  at  the  bottom 
of  the  cistern,  and  replacing  it  with  fresh  cold  water.  It  does  no  harm  to  renew  it  two 
or  three  times  at  one  steep. 

The  co«cA.— The  water  being  drawn  off,  and  occasionally  a  fresh  quantity  passed 
through,  to  wash  away  any  slimy  matter  which  may  have  been  generated  in  warm 
weather,  the  barley  is  now  laid  upon  the  couch  floor  of  stone  flags,  in  square  heaps  from 
12  to  16  inches  high,  and  left  in  that  position  for  24  hours.  At  this  period,  the  bulk 
of  the  gram  being  the  greatest,  it  may  be  gauged  by  the  revenue  oflicers  if  thev  think 
nt  Itie  moisture  now  leaves  the  surface  of  the  barley  so  completely,  that  it  imparts 
no  dampness  to  the  hand.  By  degrees,  however,  it  becomes  warm  ;  the  temperature 
nsing  JO  above  the  atmosphere,  whUe  an  agreeable  fruity  smell  is  evolved.  At  this  time, 
U  the  hand  be  thrust  into  the  heap,  it  not  only  feels  warm,  but  it  gets  bedewed  with 
moistJire.  At  this  sweating  stage,  the  germination  begins ;  the  fibrils  of  the  radicle 
tirst  sprout  forth  from  the  tip  of  every  grain,  and  a  white  elevation  appears,  that  soon 


BEER. 


129 


separates  into  three  or  more  radicles,  which  grow  rapidly  larger.  About  a  day  after  this 
appearance,  the  plumula  peeps  forth  at  the  same  point,  proceeding  thence  beneath  the 
husk  lo  the  other  end  of  the  seed,  in  the  form  of  a  green  leaflet. 

The  greatest  heal  of  the  couch  is  usually  about  96  hours  after  the  harley  has  beea 
taken  out  of  the  steep.  In  consequence,  the  radicles  tend  to  increase  in  length  with 
very  great  rapidity,  and  must  be  checked  by  artificial  means,  which  constitute  the 
chief  art  of  the  maltster.  He  now  begins  to  spread  the  barley  thinner  on  the  floor, 
and  turns  il  over  several  times  in  the  course  of  a  day,  bringing  the  portions  of  the 
interior  into  the  exterior  surface.  The  depth,  which  was  originally  15  or  16  inches* 
is  lowered  a  little  at  every  turning  over,  liU  it  be  brought  eventually  down  to  three 
or  four  inches.  Two  turnings  a  day  are  generally  required.  At  this  period  of  spread- 
ing or  flooring,  the  temperature  in  England  is  about  62°,  and  in  Scotland  5  or  6  degrees 
lower. 

About  a  day  after  the  radicles  appear,  the  rudiments  of  the  stem,  or  of  the  plimmla, 
sprout  forth,  called  by  the  English  mahsters  the  acrospire.  It  issues  from  the  same  end 
of  the  seed  as  the  radicle,  but  turns  round,  and  proceeds  within  the  husk  towards  the  other 
end,  and  would  there  come  forth  as  a  green  leaf,  were  its  progress  not  arrested.  The 
malting,  however,  is  complete  before  the  acrospire  becomes  a  leaf. 

The  barley  couch  absorbs  oxygen  and  emits  carbonic  acid,  just  as  animals  do  in  breath- 
ing, but  to  a  very  limited  extent;  for  the  grain  loses  only  three  per  cent,  of  its  weight 
upon  the  malt  floor,  and  a  part  of  this  loss  is  due  to  waste  particles.  As  the  acrospire 
creeps  along  the  surface  of  the  seed,  the  farina  within  undergoes  a  remarkable  altera- 
tion. The  gluten  and  mucilage  disappear,  in  a  great  measure,  the  color  becomes  whiter, 
and  the  substance  becomes  so  friable  Ihat  it  crumbles  into  meal  between  the  fingers! 
This  is  the  great  purpose  of  mailing,  and  il  is  known  to  be  accomplished  when  the  plu- 
mula or  acrospire  has  approached  the  end  of  the  seed.  Now  the  further  growth  must 
be  completely  stopped.  Fourteen  days  may  be  reckoned  the  usual  duration  of  the 
germinating  stage  of  the  malting  operations  in  England;  but  in  Scotland,  where  the 
temperature  of  the  couch  is  lower,  eighteen  days,  or  even  twenty-one,  are  sometimes  re- 
quired.  The  shorter  the  period  within  the  above  limits,  the  more  advantageous  is  the 
process  lo  the  maltster,  as  he  can  turn  over  his  capital  the  sooner,  and  his  malt  is  also 
somewhat  the  belter.  Bigg  is  more  rapid  in  its  germination  than  barley,  and  requires  to 
be  still  more  carefully  watched.  In  dry  weather  it  is  sometimes  necessary  to  water  the 
barley  upon  the  couch. 

Occasionally  the  odor  disengaged  from  the  couch  is  oflTensive,  resembling  that  of 
rotten  apples.  This  is  a  bad  prognostic,  indicating  either  that  the  barley  was  of  bad 
quality,  or  that  the  workmen,  through  careless  shovelling,  have  crushed  a  number  of  tht 
grains  in  turning  them  over.  Hence  when  the  weather  causes  too  quick  germination,  it 
IS  better  to  check  it  by  spreading  the  heap  out  thinner  than  by  turning  it  too  frequently 
over.  On  comparing  different  samples  of  barley,  we  shall  find  that  the  best  develop  the 
germ  or  acrospire  quicker  than  the  radicles,  and  thus  occasion  a  greater  production  of 
the  saccharine  principle;  this  conversion  advances  along  with  the  acrospire,  and  keeps 
pace  with  it,  so  that  the  portion  of  the  seed  to  which  it  has  not  reached  is  still  in  its  un- 
altered starchy  state.  It  is  never  complete  for  any  single  barleycorn  tiU  the  acrospirt: 
has  come  to  the  end  opposite  to  that  from  which  it  sprung ;  hence  one  part  of  the  corn 
may  be  sugary,  while  the  other  is  still  insipid.  If  the  grain  were  allowed  to  vegetate 
beyond  this  term,  the  radicles  being  fully  one  third  of  an  inch  long,  the  future  stem  would 
become  visibly  green  in  the  exterior;  it  would  shoot  forth  rapidly,  the  interior  of  the 
grain  would  become  milky,  with  a  complete  exhaustion  of  all  its  useful  constituents, 
and  nothing  but  the  husk  would  remain. 

In  France,  the  brewers,  who  generally  malt  their  barley  themselves,  seldom  leave  it  en 
the  couch  more  than  8  or  10  days,  which,  even  taking  into  account  the  warmer  climate 
of  their  country,  is  certainly  too  short  a  period,  and  hence  they  make  inferior  wo^t  to  the 
English  brewer,  from  the  same  quantitv  of  malt. 

At  the  end  of  the  germination,  the  radicles  have  become  I^  longer  than  the  barley, 
and  are  contorted  so  that  ihe  corns  hook  into  one  another,  but  the  acrospire  is  jus 
begmnmg  to  push  through.  A  moderate  temperature  of  the  air  is  best  adapted  to  malt- 
W.V.;  *^»^''^^'i^^>t  cannot  be  carried  on  well  during  the  heat  of  summer  or  The  colds  of 
rm  Malt-floors  should  be  placed,  in  substantial  thick-walled  buildings,  without 
access  of  the  sun    so  that  a  uniform  temperature  of  59°  or  60°  may  prevail  inside. 

bit^aUonTdT  ^"^        '''''^  ^  "^^^  "'''^^'  ^^^  ^'''^^''^   ""^  ^^^  ^"'''"'*'  ^  **"* 

«.f?"""?'K^^T'"^^'°"  *  remarkable  change  has  taken  place  in  the  substance  of  the 
hll?;.cc  f  "1"^T"'  c°"^'^'t"ent  has  almost  entirely  disappeared,  and  is  supposed  to 
hTtirn  «"i'  '^'  T'''  V}'  ^^^^^^«'  ^^^^  *  portion  of  the' starch  is  c^rrteS 
AiLZf-  ♦  °^"*=^j«|«-  The  change  is  similar  to  what  starch  undergoes  when 
dissolved  in  water,  and  digested  in  a  heat  of  about  160°  F.  aknig  with  a  little  glutei 


BBBMM 


.1 
■->     1  . 


130 


BEER. 


The  thick  paste  becomes  gradually  liquid,  transparent,  and  sweet  tasted,  and  the  solution 
contains  now,  sugar  and  gum,  mixed  with  some  unaltered  starch.  The  gluten  sufTers  a 
change  at  the  same  time,  and  becomes  acescent,  so  that  only  u  certain  quantity  of  starch 
can  be  thus  converted  by  a  quantity  of  gluten.  By  the  artificial  growth  upon  the  malt- 
Boor,  all  the  gluten  and  albumen  present  in  barley  is  not  decomposed,  and  only  about 
one  half  of  the  starch  is  converted  into  sugar;  the  other  half,  by  a  continuance  of  the 
germination,  would  only  go  to  the  growth  of  the  roots  and  stems  of  the  plant;  but  it  re- 
ceives its  nearly  complete  conversion  into  sugar  without  any  notable  waste  of  substance 
in  the  brewer's  operation  of  mashing. 

The  kiln-drying. — When  the  malt  has  become  perceptibly  dry  to  the  hand  upon 
the  floor,  it  is  taken  to  the  kiln,  and  dried  hard  with  artificial  heat,  to  stop  all  further 
growth,  and  enable  it  to  be  kept,  without  change,  for  future  use,  at  any  time.  The 
malt-kiln,  which  is  particularly  described  in  the  next  page,  is  a  round  oi  a  square 
chamber,  covered  with  perforated  plates  of  cast  iron,  whojic  area  is  heated  by  a  stove  or 
furnace,  so  that  not  merely  the  plates  on  which  the  malt  is  laid  are  warmed,  but  the  air 
which  passes  up  through  the  stratum  of  malt  itself,  with  the  eflect  of  carrying  off  very 
rapidly  the  moisture  from  the  grains.  The  layer  of  malt  should  be  about  3  or  4  inches 
thick,  and  evenly  spread,  and  its  heat  should  be  steadily  kept  at  from  the  90th  to  the 
100th  degree  of  Fahrenheit's  scale,  till  the  moisture  be  mostly  exhaled  from  it.  During 
this  time  the  malt  must  be  turned  over  at  first  frequently,  and  latterly  every  three  or 
four  hours.  When  it  is  nearly  dry,  its  temperature  should  be  raised  to  from  145®  to 
165°  F.,  and  it  must  be  kept  at  this  heat  till  it  has  assumed  the  desired  shade  of  color, 
which  is  commonly  a  brownish-yellow  or  a  yellowish-broWn.  The  fire  is  now  allowed 
to  die  out,  and  the  malt  is  left  on  the  plates  till  it  has  become  completely  cool ;  a  result 
promoted  by  the  stream  of  cool  air,  which  now  rises  up  through  the  bars  of  the  grate ; 
or  the  thoroughly  dry  browned  malt  may,  by  damping  the  lire,  be  taken  hot  from  the 
plates,  and  eooled  upon  the  floor  of  an  adjoining  apartment.  The  prepared  malt  musl 
be  kept  in  a  dry  lofl,  where  it  can  be  occasionally  turned  over  till  it  is  used.  The 
period  of  kiln-drying  should  not  be  hurried.  Many  persons  employ  two  days  in  this 
operation. 

According  to  the  color  and  the  degree  of  dryin?,  malt  is  distributed  into  three  sorts ; 
pale,  yellow,  and  brown.  The  first  is  produced  when  the  highest  heat  to  which  it  has 
been  subjected  is  from  90°  to  100°  F. ;  the  amber  yellow,  when  it  has  sufl'ered  a  heat 
of  122°;  and  the  brown  when  it  has  been  treated  as  above  described.  The  black  malt 
used  by  the  porter  brewer  to  color  his  beer,  has  sufl'ered  a  much  higher  heat,  and  is 
partially  charred.  The  temperature  of  the  kiln  should,  in  all  cases,  be  most  gradually 
raised,  and  most  equably  maintained.  If  the  heat  be  too  great  at  the  beginning,  the 
husk  gets  hard  dried,  and  hinders  the  evaporation  of  the  water  from  the  interior  sub- 
stance; and  should  the  interior  be  dried  by  a  stronger  heat,  the  husk  will  probably  splil, 
and  the  farina  become  of  a  horny  texture,  very  reuactor)'  in  the  mash-tun.  In  general, 
it  is  preferable  to  brown  malt,  rather  by  a  long-continued  moderate  heat,  than  by  a  more 
violent  heat  of  shorter  duration,  which  is  apt  to  carbonize  a  portion  of  the  mucilaginous 
sugar,  and  to  damage  the  article.  In  this  way,  the  sweet  is  sometimes  converted  into  a 
bitter  principle. 

During  the  kiln-drying,  the  roots  and  acrospire  of  the  barley  become  brittle,  and  fall 
off;  and  are  separated  by  a  wire  sieve  whose  meshes  are  too  small  to  allow  the  malt 
itself  to  pass  through. 

A  quantity  of  good  barley,  which  weighs  100  pounds,  being  ju'^tciously  malted,  will 
weigh,  after  drj'ing  and  sifting,  80  pounds.  Since  the  raw  grain,  dried  by  itself  at  the 
same  temperature  as  the  malt,  would  lose  12  per  cent,  of  its  weight  in  water,  the  malt 
process  dissipates  out  of  these  remaining  88  pounds,  only  8  pounds,  or  8  per  cent,  of  the 
raw  barley.    This  loss  consists  of— 

1^  per  cent,  dissolved  out  in  the  steep  water, 
3       —        dissipated  in  the  kiln, 
3        —        by  the  falling  of  the  fibrils, 
I     —        of  waste. 

The  bulk  of  good  malt  exceeds  that  of  the  barley  from  which  it  was  made,  by  about  8 
<«•  9  per  cent. 

The  operation  of  kiln-drying  is  not  confined  to  the  mere  expulsion  of  the  moisture 
from  the  germinated  seeds;  but  it  serves  to  convert  into  sugar  a  portion  of  the  starch 
which  renjained  unchanged,  and  that  in  a  twofold  way;  first,  by  the  action  of  the 
gluten  «pon  the  fecula  at  an  elevated  temperature,  as  also  by  the  species  of  roasting 
which  the  starch  undergoes,  and  which  renders  it  of  a  gummy  nature.  (See  Starch.) 
We  shall  have  a  proof  of  this  explanation,  if  we  dry  one  portion  of  the  malt  in  a 
naturally  dry  atmosphere,  and  another  in  a  moderately  warm  kiln;  the  former  will 
yield  less  saccharine  extract  than  the  latter.  Moreover,  the  kiln-dried  malt  has  a  pe- 
culiar, agreeable,  and  faintly  burned  taste,  probably  from  a  small  portion  of  empy* 


•4' 


I 


BEER. 


131 


rcumatic  oil  formed  in  the  husk,  and  which  not  only  imparts  its  flavor  to  the  beer,  but 
also  contributes  to  its  preservation.  It  is  therefore  obvious,  that  the  skilful  preparation 
of  the  malt  must  have  the  greatest  influence  both  on  the  quantity  and  quality  of  the  worts 
to  be  made  from  it.  If  the  germination  be  pushed  too  far,  a  part  of  the  extractible  mat- 
ter is  wasted ;  if  it  has  not  advanced  far  enough,  the  malt  will  be  too  raw,  and  too  much 
of  its  substance  will  remain  as  an  insoluble  starch ;  if  it  is  too  highly  kiln  dried,  a  portion 
of  its  sugar  will  be  caramelized,  and  become  bitter;  and  if  the  sweating  was  imperfect 
or  irregular,  much  of  the  barley  may  be  rendered  lumpy  and  useless.  Good  malt  is  dis- 
tinguishable by  the  following  characters  : — 

The  grain  is  round  and  full,  breaks  freely  between  the  teeth,  and  has  a  sweetish  taste, 
an  agreeable  smell,  and  is  full  of  a  soft  flour  from  end  to  end.  It  affords  no  unpleasant 
flavor  on  being  chewed ;  it  is  not  hard,  so  that  when  drawn  along  an  oaker\  table  across 
the  fibres,  it  leaves  a  while  streak,  like  chalk.  It  swims  upon  water,  while  unmalted 
barley  sinks  in  it.  Since  the  quality  of  the  malt  depends  much  on  that  of  the  barley,  the 
same  sort  only  should  be  used  for  one  malting.  New  barley  germinates  quicker  than 
old,  which  is  more  dried  up ;  a  couch  of  a  mixture  of  the  two  would  be  irregular,  and 
difllcult  to  regulate. 

Description  of  the  maZ/-fei7n.—Fig».  107,108,109,110,  exhibit  the  construction  of  a  well- 
contrived  malt-kiln.  Fig.  107, is  the  ground  plan  :  ^g.  108,is  the  vertical  section;  and 
rtg«.109,and  110,  a  horizontal  and  vertical  section  in  the  line  of  the  malt-plates.  The  same 
letters  denote  the  same  parts  in  each  of  the  figures.    A  cast-iron  cupola-shaped  oven  is 

108 


eupported  in  the  middle,  upon  a  wall  of  brickwork  four  feet  high ;  and  beneath  it,  are  the 
grate  and  its  ash-pit.  The  smoke  passes  off  throu-h  two  equi-distant  pipes  into  the  chim- 
ney. I  he  oven  is  surrounded  with  four  pillars,  on  whose  top  a  stone  lintel  is  laid  :  a  is 
the  srate  9  inches  below  the  sole  of  the  oven  6 ;  c  c  c  c  are  the  four  nine-inch  strong 
pilars  of  hackwork  which  bear  the  lintel  m  ;  d  d  d  d  d  d  are  strong  nine-inch  pillar^ 
Which  support  the  girder  and  joists  upon  which  perforated  plates  repose;  e  denotes  a 
vaul  ed  arch  on  each  of  the  four  sides  of  the  oven  ;  /  is  the  space  between  the  kiln 
tho  r  n^  ^-fi  '  *"'?  ^^l'*^^  ^  workman  may  enter,  to  inspect  and  clean  the  kiln  ;  g  g, 
o  fi,M  '.T.  "'^fi^'  f^^  ^O'^^  ^•'"'  "P"'*  ^^'^^  the  arches  rest;  h,  the  space  for  the  ashes 
th.!  [  •;  "'  ,u  ^^^f"""*'  o^  the  kiln ;  /  /,  junction-pieces  to  connect  the  pipes  r  r  with 
ab^ni  thrL  r^  *  A  °^«"aching  them  is  shown  in  fig.  109.  These  smoke-pipes  lie 
Uiev  a^  ,.?±  r  T^^'  '^'  ^'■^"  P^*'^''  ^^'^  ^^  the  same  distance  from  the  side  walls: 
wey  are  supported  upon  iron  props,  which  are  made  fast  to  the  arches.    InfigAOS.u 


132 


BEER, 


.11  < 


'» 


II 


ill 


5     t 


shows  their  section;  at  $  »,  yig.  109, they  enter  the  chimney,  which  is  provided  with  two 
register  or  damper  plates,  to  regulate  the  draught  through  the  pipes.  These  registers 
aie  represented  by  t  t,  Jig.  110,  which  shows  a  perpendicular  section  of  the  chimney. 
nit  fig.  108,is  the  lintel  which  causes  the  heated  air  to  spread  laterally  instead  cf 
ascending  in  one  mass  in  the  middle,  and  prevents  any  combustible  particles  from  falling 
upon  the  iron  cupola,  n  n  are  the  main  girders  of  iron  for  the  iron  beams  o  o,  upon 
which  the  perforated  plates  ;;  lie;  q,fig.  108,is  the  vapor  pipe  in  the  middle  of  the  roof, 
which  aUows  the  steam  of  the  drjing  malt  to  escape.  The  kiln  may  be  heated  either 
with  coal  or  wood. 

The  size  of  this  kiln  is  about  20  feet  square ;  but  it  may  be  made  proportionally  either 
smaller  or  greater.  The  perforated  floor  should  be  large  enough  to  receive  the  contents 
«]f  one  steep  or  couch. 

The  perforated  plate  might  be  conveniently  heated  by  steam  pipes,  laid  zig-zag,  or  in 
parallel  Liies  under  it;  or  a  wire-gauze  web  might  be  stretched  upon  such  pipes.  The 
wooden  joists  of  a  common  floor  would  answer  perfectly  to  support  this  steam-range,  and 
the  heat  of  the  pipes  would  cause  an  abundant  circulation  of  air.  For  drying  the  pale 
malt  of  the  ale  brewer,  this  plan  is  particularly  well  adapted. 

The  kiln-dried  malt  is  sometimes  ground  between  stones  in  a  common  corn  mill,  like 
oatmeal ;  but  it  is  more  generally  crushed  between  iron  rollers,  at  least  for  the  purposes 
of  the  London  brewers. 

The  crushing  mill. — The  cylinder  malt-mill  is  constructed  as  shown  in^g*.  Ill,  112. 
I  is  the  sloping- trough,  by  which  the  malt  is  let  down   from  its  bin  or  floor  to   the 

hopper  A  of  the  mill,  whence 
it  is  progressively  shaken  in 
between  the  rollers  B  D.  The 
rollers  are  of  iron,  truly  cylin- 
drical, and  their  ends  rest  in 
bearers  of  hard  brass,  fitted  into 
the  side  frames  of  iron.  A  screw 
E  goes  through  the  upright, 
and  serves  to  force  the  bearer 
of  the  one  roller  towards  that  of 
the  other,  so  as  to  bring  them 
closer  together  when  the  crush- 
ing efiect  is  to  be  increased.  G 
is  the  square  end  of  the  axis, 
by  which  one  of  the  rollers 
may  be  turned  either  by  the 
hand  or  by  power;  the  other 
derives  its  rotatory  motion  from  a  pair  of  eqiml-toolhed  wheels  H,  which  are  fitted  to 
the  other  end  of  the  axes  of  the  rollers,  rf  is  a  catch  which  works  into  the  teeth  of 
a  ratchet  wheel  on  the  end  of  one  of  the  rollers  (not  shown  in  this  view.)  The  lever 
c  strikes  the  trough  b  at  the  bottom  of  the  hopper,  and  gives  it  the  shaking  motion  for 
discharging  the  malt  between  the  rollers,  from  the  slide  sluice  a.  e  e,fig.  Ill,  are 
scraper-plates  of  sheet  iron,  the  edges  of  which  press  by  a  weight  against  the  surfaces 
of  the  rollers,  and  keep  them  clean. 

Instead  of  the  cylinders,  some  employ  a  crushing  mill  of  a  conical-grooved  form  like  a 
coflfee-mill,  upon  a  large  scale.     (See  the  general  plan,  infra.) 

The  mashing  and  boiling. — Mashing  is  the  operation  by  which  the  wort  is  extracted, 
or  eliminated  from  the  malt,  and  whereb)  a  saccharo-mucilaginous  extract  is  made 
from  it.  The  malt  should  not  in  general  be  ground  into  a  fine  meal,  for  in  that  case 
it  would  be  apt  to  form  a  cohesive  paste  with  hot  water,  or  to  set,  as  it  is  called,  and  to 
be  difficult  to  drain.  In  crushed  malt,  the  husk  remains  nearly  entire,  and  thus  helps 
to  keep  the  farinaceous  particles  open  and  porous  to  the  action  of  the  water.  The  bulk 
of  the  crushed  malt  is  about  one  fifth  greater  than  that  of  the  whole,  or  one  bushel  of 
malt  gives  a  bushel  and  a  quarter  of  crushed  malt.  This  is  frequently  allowed  to  lie 
a  few  days  in  a  cool  place,  in  order  that  it  may  attract  moisture  from  the  air,  which  it 
does  very  readily  by  its  hygrometric  power.  Thus,  the  farinaceous  substance  which  had 
been  indurated  in  the  kiln,  becomes  soft,  spongy,  and  fit  for  the  ensuing  process  of  watery 
extraction. 

Mashing  has  not  for  its  object  merely  to  dissolve  the  sugar  and  gum  already  present 
in  the  malt,  but  also  to  convert  into  a  sweet  mucilage  the  starch  which  had  remained 
unchanged  during  the  germination.  We  have  already  stated  that  starch,  mixed  with 
gluten,  and  digested  for  some  time  with  hot  water,  becomes  a  species  of  sugar.  This 
conversion  takes  place  in  the  mash-tun.  The  malted  barley  contains  not  only  a  portion 
of  gluten,  but  diastase  more  than  sufficient  to  convert  the  starch  contained  in  it^  b)  thii 
means,  into  sugar. 


BEER. 


198 


i 

ll 


The  researches  of  Payen  and  Persoz  show,  that  the  mucilage  formed  by  the  reaction 
of  malt  upon  starch,  may  either  be  converted  into  sugar,  or  be  made  into  permanent 
gum,  according  to  the  temperature  of  the  water  in  which  the  materials  are  digested. 
We  take  of  pale  barley  malt,  ground  fine,  from  6  to  10  parts,  and  100  parts  of  starch;  we 
heat,  by  means  of  a  water-bath,  400  parts  of  water  in  a  copper,  to  about  80°  F. ;  we 
then  stir  in  the  malt,  and  increase  the  heat  to  140°  F.,  when  we  add  the  starch, 
and  stir  well  together.  We  next  raise  the  temperature  to  ISS**,  and  endeavor  to 
maintain  it  constantly  at  that  point,  or  at  least  to  keep  it  within  the  limits  of  167°  on 
the  one  «ide,  and  ISS**  on  the  other.  At  the  end  of  20  or  30  minutes,  the  original  milky 
and  pasty  solution  becomes  thinner,  and  soon  after  as  fluid  nearly  as  water.  This  is  the 
moment  in  which  the  starch  is  converted  into  gum,  or  into  that  substance  which  the 
French  chemists  call  dextrine^  from  its  power  of  polarizing  light  to  the  right  hand,  whereas 
common  gam  does  it  to  the  left.  If  this  merely  mucilaginous  solution,  which  seems  to 
be  a  mixture  of  gum  with  a  little  liquid  starch  and  sugar,  be  suitably  evaporated,  it  may 
serve  for  various  purposes  in  the  arts  to  which  gum  is  applied,  but  with  this  view,  it 
must  be  quickly  raised  to  the  boiling  point,  to  prevent  the  farther  operation  of  the  malt 
upon  it.  If  we  wish,  on  the  contrary,  however,  to  promote  the  saccharine  fermentation, 
for  the  formation  of  beer,  we  must  maintain  the  temperature  at  between  158°  and  167^ 
for  three  or  four  hours,  when  the  greatest  part  of  the  gum  will  have  passed  into  sugar, 
and  by  evaporation  of  the  liquid  at  the  same  temperature,  a  starch  sirup  maybe  obtained 
like  that  procured  by  the  action  of  sulphuric  acid  upon  starch.  The  substance,  which  oper- 
ates in  the  formation  of  sugar,  or  is  the  peculiar  ferment  of  the  sugar  fermentation,  may 
be  considered  as  a  residuum  of  the  duten  or  vegetable  albumen  in  the  germinating 
grain  :  it  is  reckoned  by  Payen  and  Persoz,  a  new  proximate  principle  called  diastase, 
which  is  formed  during  malting,  in  the  grains  of  barley,  oats,  and  wheat,  and  may  be 
separated  in  a  pure  state,  if  we  moisten  the  malt  flour  for  a  few  minutes  in  cold  water, 
press  it  out  strongly,  filter  the  solution,  and  heat  the  clear  liquid  in  a  water  bath,  to  the 
temperature  of  158°.  The  greater  part  of  that  albuminous  azotized  substance  is  thus 
coagulated,  and  is  to  be  separated  by  a  fresh  filtration ;  after  which,  the  clear  liquid  is 
to  be  treated  with  alcohol,  when  a  flocky  precipitate  appears,  which  is  diastase.  To  pu- 
rify it  still  further,  especially  from  the  azotized  matter,  we  should  dissolve  it  in 
water,  and  precipitate  again  with  alcohol.  When  dried  at  a  low  temperature,  it  appears 
as  a  solid  white  substance,  which  contains  no  azote ;  is  insoluble  in  alcohol,  but  dissolves 
in  water  and  proof  spirit.  Its  solution  is  neutral  and  tasteless ;  when  left  to  itself,  it 
changes  with  greater  or  less  rapidity  according  to  the  temperature,  and  becomes  sour  at 
a  temperatiu^e  of  from  149°  to  167°.  It  has  the  property  of  converting  starch  into  gum 
(dextrine)  and  sugar,  and  indeed,  when  sufficiently  pure,  with  such  energy  that  one 
part  of  it  disposes  2000  parts  of  dry  starch  to  that  change,  but  it  operates  the  quicker  the 
greater  its  quantity.  Whenever  the  solution  of  diastase  with  starch  or  with  dextrine  is 
heated  to  the  boiling  point,  it  loses  the  sugar-fermenting  property.  One  hundred  parts 
of  well-malted  starch  appear  to  contain  about  one  part  of  this  substance. 

We  can  now  understand  the  theory  of  malting,  and  the  limits  between  which  the 
temperature  of  the  liquor  ought  to  be  maintained  in  this  operation ;  namely,  the  rau«»e 
between  157°  and  160°  F.  It  has  been  ascertained  as  a  principle  in  mashins,  that 
the  best  and  soundest  extract  of  the  malt  is  to  be  obtained,  first  of  all,  by  beginning  to 
work  with  water  at  the  lowest  of  these  heats,  and  to  conclude  the  mash  with  water  at 
the  highest.  Secondly,  not  to  operate  the  extraction  at  once  with  the  whole  of  the  water 
that  IS  to  be  employed ;  but  with  separate  portions  and  by  degrees.  The  first  portion  is 
added  with  the  view  of  penetrating  equally  the  crushed  malt,  an!  of  extracting  the 
already  furmeJ  sugar ;  the  next  for  efl'ecting  the  sugar  fermentation  by  the  action  of  the 
diastase.  By  this  means,  also,  the  starch  is  not  allowed  to  run  into  a  cohesive  paste  and 
the  extract  IS  more  easily  drained  from  the  poorer  mass,  and  comes  ofl"  in  the  form  of  a 
nearly  limpid  wort.  The  thicker,  moreover,  or  the  less  diluted  the  mash  is,  so  much  the 
easier  is  the  wort  fined  in  the  boiler  or  copper  by  the  coagulation  of  the  albuminous 
matter:  these  principles  illustrate,  in  every  condition,  the  true  mode  of  c-mviuctine 
the  mashing  process ;  but  different  kinds  of  malt  require  a  different  treatrarat.  Pale 
and  slightly  kilned  malt  requires  a  somewhat  lower  heat  than  malt  highly  kilned,  because 
the  former  has  more  u-decomposed  starch,  and  is  more  ready  to  become  pasty.  The 
ionner  also,  for  the  same  reason,  needs  a  more  leisurely  infusion  than  the  latter,  for  its 
conv-ersion  into  mucilaginous  susar.  The  more  sugar  the  malt  contains,  the  more  is  its 
saccharine  fermrntation  accelerated  by  the  action  of  the  diastase.  What  has  been  here 
said  of  pale  malt  is  still  more  applicable  to  the  case  of  a  mixture  of  raw  grain  with  malt, 
tor  It  requires  still  gentler  heats,  and  more  cautious  treatment. 

•^K-  V  •  ,,  ^P^^lj-J'i'*  is  a  Jarge  circular  tub  with  a  double  bottom  ;  the  uppermost  of 
Which  IS  called  a  false  bottom,  and  is  pierced  with  many  holes.  There  is  a  space  of  about 
Jaa  '"''•  t^'^^e"  the  two,  into  which  the  stopcocks  enter,  for  letting  m  the  water 
and  drawing  oflf  the  wort.   The  holes  of  the  false  bottom  should  be  burned,  and  not  bored^ 


134 


BEER. 


BEER. 


185 


-.--i 


to  prevent  the  chance  of  their  filling  up  by  the  swelling  of  the  wood,  which  would 
obstruct  the  drainage :  the  holes  should  be  conical,  and  largest  below,  being  about  |  of 
an  inch  there,  and  |  at  the  upper  surface.  The  perforated  bottom  must  be  fitted  truly 
at  the  sides  of  the  mash-tun,  so  that  no  grains  may  pass  through.  The  mashed  liquor  is 
let  off  into  a  large  back,  from  which  it  is  pumped  into  the  wort  coppers.  The  mash-tun 
is  provided  with  a  peculiar  rotatory  apparatus  for  agitating  the  crushed  grains  and  water 
together,  which  we  shall  presently  describe.  The  size  of  the  wort  copper  is  proportional 
to  the  amount  of  the  brewing,  and  it  must,  in  general,  be  at  least  so  large  as  to 
operate  upon  the  whole  quantity  of  wort  made  from  one  mashing ;  that  is,  for  every 
quarter  of  malt  mashed,  the  copper  should  contain  140  gallons.  The  mash-tun  ought  to 
be  at  least  a  third  larger,  and  of  a  conical  form,  somewhat  wider  below  than  above. 
The  quantity  of  water  to  be  employed  for  mashing,  or  the  extraction  of  the  wort,  de- 
pends upon  the  greater  or  less  strength  to  be  given  to  the  beer.  The  seeds  of  the  crushed 
malt,  after  the  wort  is  drawn  off,  retain  still  about  32  gallons  of  water  for  every  quartei 
of  malt.  In  the  boiling,  and  evaporation  from  the  coolers,  40  gallons  of  water  are  dis- 
sipated from  one  quarter  of  malt ;  constituting  72  gallons  in  all.  If  13  quarters  of  barley 
be  taken  to  make  1500  gallons  of  beer,  2400  gallons  of  water  must  therefore  be  required 
(or  the  mashing.  This  example  will  give  an  idea  of  the  proportions  for  an  ordinary 
quality  of  beer. 

When  the  mash  is  to  begin,  the  copper  must  be  filled  with  water,  and  heated.  As  soon 
as  the  water  has  attained  the  heat  of  145°  m  summer,  or  167°  in  winter,  600  gallons  of  it 
are  to  be  run  off  into  the  mash-tun,  and  the  13  quarters  of  crushed  malt  are  to  be  gradu- 
ally thrown  in  and  well  intermixed  by  proper  agitation,  so  that  it  may  be  uniformly 
moistened,  and  no  lumps  may  remain.  After  contj.iuing  the  agitation  in  this  way  for  one 
half  or  three  quarters  of  an  hour,  the  water  in  the  copper  will  have  approached  to  its 
boiling  point,  when  450  gaUons  at  the  temperature  of  about  200°  are  to  be  run  into  the 
mash-tun,  and  the  agitation  is  to  be  renewed  till  the  whole  assumes  an  equally  fluid 
state :  the  tun  is  now  to  be  well  covered  for  the  p^eser^'ation  of  its  heat,  and  to  be 
allowed  to  remain  at  rest  for  an  hour,  or  an  hour  and  a  half.  The  mean  temperature  of 
this  mash  may  be  reckoned  at  about  145°.  The  time  which  is  necessary  for  the  trans- 
muting heat  of  the  remaining  starch  into  sugar  depends  on  the  quality  of  the  malt. 
Brown  malt  requires  less  time  than  pale  malt,  and  still  less  than  a  mLxture  with  raw 
grain,  as  already  explained.  After  the  mash  has  rested  the  proper  time,  the  tap  of  the 
tun  is  opened,  and  the  clear  wort  is  to  be  drawn  out  into  the  under  back.  If  the  wort 
that  first  flows  is  turbid,  it  must  be  returned  into  the  tun,  till  it  runs  clear.  The  amount 
of  this  first  wort  may  be  about  675  gallons.  Seven  hundred  and  fifty  gallons  of  water, 
at  the  temperature  of  200°,  are  now  to  be  introduced  up  through  the  drained  malt,  into 
the  tun,  and  the  mixture  is  to  be  agitated  till  it  becomes  uniform,  as  before.  The  mash- 
tun  is  then  to  be  covered,  and  allowed  to  remain  at  rest  for  an  hour.  The  temperature 
of  this  mash  is  from  167°  to  174°.  While  the  second  mash  is  making,  the  worts  of  the 
first  are  to  be  pumped  into  the  wort  copper,  and  set  a-boiling  as  speedily  as  possible. 
The  wort  of  the  second  mash  is  to  be  drawn  off  at  the  proper  time,  and  added  to  the 
copper  as  fast  as  it  wiU  receive  it,  without  causing  the  ebullition  to  stop. 

A  third  quantity  of  water  amounting  to  600  gallons,  at  200°,  is  to  be  introduced  into 
the  mash-tun,  and  after  half  an  hour  is  to  be  drawn  off,  and  either  pumped  into  the  wort 
copper,  or  reserved  for  mashing  fresh  malt,  as  the  brewer  may  think  fit. 

The  quantity  of  extract,  per  barrel  weight,  which  a  quarter  of  malt  yields  to  wort, 
amounts  to  about  84  lbs.  The  wort  of  the  first  extract  is  the  strongest ;  the  second  con- 
tains, commonly,  one  half  the  extract  of  the  first ;  and  the  third,  one  half  of  the  second ; 
according  to  circumstances. 

To  measure  the  degrees  of  concentration  of  the  worts  drawn  off  from  the  tun,  a  par- 
ticular form  of  hydrometer,  called  a  saccharometer,  is  employed,  which  indicates  the 
number  of  pounds  weight  of  liquid  contained  in  a  barrel  of  36  gallons  imperial  measure. 
Mow,  as  the  barrel  of  water  weighs  360  lbs.,  the  indication  of  the  instrument,  when 
placed  in  any  wort,  shows  by  how  many  pounds  a  barrel  of  that  wort  is  heavier  than  a 
barrel  of  water;  thus,  if  the  instrument  sinks  with  its  poise  till  the  mark  10  is  upon  a 
line  with  the  surface  of  the  liquid,  it  indicates  that  a  barrel  of  that  wort  weighs  ten 
pounds  more  than  a  barrel  of  water.     See  Saccharometer. 

Or,  supposing  the  barrel  of  wort  weighs  396  lbs.,  to  convert  that  number  into  specific 
gravity,  we  have  the  following  simple  rule : — 

360:396  ::  100  :  MOO; 
at  which  densify,  by  my  experiments,  the  wort  contains  25  per  cent,  of  solid  extract. 

Having  been  employed  to  make  experiments  on  the  density  of  worts,  and  the  ferment- 
ative changes  which  they  undergo,  for  the  information  of  a  committee  of  the  House  of 
Commons,  which  sat  in  July  and  August,  1830,  I  shall  here  introduce  a  short  abstract  o( 
that  part  of  my  evidence  which  bears  upon  the  present  subject. 

Mr  first  object  was  to  clear  up  the  di/ficulties  which,  to  common  apprehension,  hung 


over  the  matter,  from  the  difference  in  the  scales  of  the  sacc'aarometers  m.  use  among  the 
brewers  and  distillers  of  England  and  Scotland.  I  found  that  one  quarter  of  good  malt 
would  yield  to  the  porter-brewer  a  barrel  Imperial  measure  of  wort,  at  the  conctnfrated 
specific  gravity  of  1*234.  Now,  if  the  decimal  part  of  this  number  be  multiplied  by 
360,  being  the  number  of  pounds  weight  of  water  in  the  barrel,  the  product  will  denote 
the  excess  in  pounds,  of  the  weight  of  a  barrel  of  such  concentrated  wort,  over  that  of 
a  barrel  of  water ;  and  that  product  is,  in  the  present  case,  84*24  pounds. 

Mr.  Martineau,  jun.,  of  the  house  of  Messrs.  Whitbread  and  Company,  and  a  eentlc- 
man  connected  with  another  great  London  brewery,  had  the  kindness  to  inform  me  that 
their  average  product  from  a  quarter  of  malt  was  a  barrel  of  84  lbs.  gravity.  It  is  ob- 
vious, therefore,  that  by  taking  the  mean  operation  of  two  such  great  establishments,  I 
must  have  arrived  very  nearly  at  the  truth 

It  ought  to  be  remarked  that  such  a  high  density  of  wort  as  1*234  is  not  the  result  of 
any  direct  experiment  in  the  brewery,  for  infusion  of  malt  is  never  drawn  off  so  strong; 
that  densiiy  is  deduced  by  computation  from  the  quantity  and  quality  of  several  succes- 
sive infusions ;  thus,  supposing  a  first  infusion  of  the  quarter  of  malt  to  yield  a  barrel  of 
specific  gravity  1*112,  a  second  to  yield  a  barrel  at  1-091,  and  a  third  a  barrel  at  1*031, 
we  shall  have  three  barrels  at  the  mean  of  these  three  numbers,  or  one  barrel  at  their 
sum,  equal  to  1*234. 

I  may  here  observe  that  the  arithmetical  mean  or  sum  is  not  the  true  mean  or  sum  of 
the  two  specific  gravities  ;  but  this  difference  is  either  not  known  or  disregarded  by  the 
brewers.  At  low  densities  this  difference  is  inconsiderable,  but  at  high  densities  it  would 
lead  to  serious  errors.  At  specific  gravity  1-231,  wort  or  sirup  contains  one  half  of  its 
weight  of  solid  pure  saccharum,  and  at  1*1045  it  contains  one  fourth'of  its  weight;  but 
the  brewer's  rule,  when  here  applied,  gives  for  the  mean  specific  gravity  1*1155= 

^t :    The  contents  in  solid  saccharine  matter  at  that  density  are  however  27^ 

per  cent.,  showing  the  rule  to  be  2\  lbs.  wrong  in  excess  on  100  lbs.,  or  9  lbs.  per  barrel. 

The  specific  gravity  of  the  solid  dry  extract  of  malt  wort  is  1*264 ;  it  was  taken  in  oil 
of  turpentine,  and  the  result  reduced  to  distilled  water  a^  unity.  Its  specific  volume  is 
0*791 1,  that  is,  10  lbs.  of  it  will  occupy  the  volume  of  7*911  lbs.  of  water.  The  mean 
specific  gravity,  by  computation  of  a  solution  of  that  extract  in  its  own  weight  of  water, 
is  1*1166;  but  by  experiment,  the  specific  gravity  of  that  solution  is  1*216,  showing 
considerable  condensation  of  volume  in  the  act  of  combination  with  water. 

The  following  Table  shows  the  relation  between  the  specific  gravities  of  solutions  of 
malt  extract,  and  the  per-centage  of  solid  extract  they  contain : 


Extr  Malt. 

Water. 

Malt  Extract  in  100. 

Sugar  in  100. 

Specific  gravity. 

600           H 

- 

600 

50-00 

4700 

1-2160 

600            -J 

- 

900 

40*0 

37-00 

M670 

600 

- 

1200 

33-3 

31-50 

M350 

600 

- 

1500 

28*57 

26-75 

1- 11.30 

600            J 

— 

1800 

25-00 

24*00 

1*1000 

The  extract  of  malt  was  evaporated  to  dryness,  at  a  temperature  of  about  250®  F., 
without  the  slightest  injury  to  its  quality,  or  any  empvreumatic  smell.  Bate's  tables 
have  been  constructed  on  solutions  of  sugar,  and  not  with  solutions  of  extract  of  malt, 
or  they  agree  sufficiently  well  with  the  former,  but  differ  materially  from  the  latter. 
Allan's  tables  give  the  amount  of  a  certain  form  of  solid  saccharine  matter  extracted 
from  malt,  and  dried  at  175°  F.,  in  correspondence  to  the  specific  gravity  of  the  solution; 
but  I  have  found  it  impossible  to  make  a  solid  extract  from  infusions  of  malt,  except  at 
much  higher  temperatures  than  175°  F.  Indeed,  the  numbers  on  Allan's  saccharometei 
scale  clearly  show  that  his  extract  was  by  no  means  dry:  thus,  at  1*100  of  gravity  he 
assigns  29*669  per  cent,  of  solid  saccharine  matter ;  whereas  there  is  at  that  density  of 
solid  extract  only  25  per  cent.  Again,  at  M35,  Allan  gives  40  parts  per  cent,  of  soUd 
extract,  whereas  there  are  only  33 1  present. 

By  the  triple  mashing  operations  above  described,  the  malt  is  so  much  exhausted  that 
It  can  5Meld  110  further  extract  useful  for  stron-  beer  or  porter.  A  weaker  wort  might 
no  doubt  still  be  drawn  off  for  small  beer,  or  for  contributing  a  little  to  the  strength  of 
the  next  mashing  of  fresh  malt.  But  this  I  beUeve  is  seldom  practised  bv  respectable 
brewers,  as  it  impoverishes  the  grains  which  they  dispose  of  for  feeclin?  cattle. 

1  he  wort  should  be  transferred  into  the  copper,  and  made  to  boil  as  soon  as  possible, 
lor  If  It  remains  long  m  the  under-back  it  is  apt  to  become  acedcent.  The  steam  more- 
over  raised  from  it  m  the  act  of  boiHns  serves  to  screen  it  from  the  oxv-enating  or  acidi- 
tymg  influence  of  the  atmosphere.  UntU  it  begins  to  boU,  the  air  should  be  excluded 
by  some  kind  of  a  cover. 


136 


BEER. 


BEER. 


13T 


. 


!     t 


I     ■! 


li 


Sometimes  the  first  wort  is  brewed  by  itself  into  strong  ale,  the  second  by  itself  into  an 
in  termed  iate  quality  ;  and  the  third  into  small  beer  ;  but  this  practice  is  not  much  fol- 
lowed in  this  country. 

We  shall  now  treat  of  the  boiling  in  of  the  hops.  The  wort  drawn  from  the  mash- 
tun,  whenever  it  is  pumped  into  the  copper,  must  receive  its  allowance  of  hops.  Besides 
evaporating  off  a  portion  of  the  water,  and  thereby  concentrating  the  wort,  boiling  has  a 
twofold  object.  In  the  first  place,  it  coagulates  the  albuminous  matter,  partly  by  the 
heat,  and  partly  by  the  principles  in  the  hops,  and  thereby  causes  a  general  clarification 
of  the  whole  mass,  with  the  effect  of  separating  the  muddy  matters  in  a  flocculent  form. 
Secondly,  during  the  ebullition,  the  residuary  starch  and  hordeine  of  the  malt  are  con- 
verted into  a  limpid  sweetish  mucilage,  the  dextrine  above  described ;  while  some  of  the 
glutinous  stringy  matter  is  rendered  insoluble  by  the  tannin  principle  of  the  hops,  which 
favors  still  further  the  clearing  of  the  wort.  By  both  operations  the  keeping  quality 
of  the  beer  is  improved.  This  boil  must  be  continued  during  several  hours ;  a  longer 
time  for  the  stronger,  and  a  shorter  for  the  weaker  beers.  There  is  usually  one  seventh 
or  one  sixth  part  of  the  water  dissipated  in  the  boiling  copper.  This  process  is  known 
to  have  cont»'^ued  a  sufficient  time,  if  the  separation  of  the  albuminous  flocks  is  distinct, 
and  if  these  are  found,  by  means  of  a  proof  gauge  suddenly  dipped  to  the  bottom,  to  be 
collected  there,  while  the  supernatant  liquor  has  become  limpid.  Two  or  three  hours* 
boil  is  deemed  long  enough  in  many  well-conducted  breweries ;  but  in  some  of  those  in 
Belgium,  the  boiling  is  continued  from  10  to  15  hours,  a  period  certainly  detrimental  to 
the  aroma  derived  from  the  hop. 

Many  prefer  adding  the  hops  when  the  wort  has  just  come  to  the  boiling  point. 
Their  effect  is  to  repress  the  further  progress  of  fermentation,  and  especially  the  passage 
into  the  acetous  stage,  which  would  otherwise  inevitably  ensue  in  a  few  days.  In  this 
respect,  no  other  vegetable  production  hitherto  discovered  can  be  a  substitute  for  the 
hop.  The  odorant  principle  is  not  so  readily  volatilized  as  would  at  first  be  imagined; 
for  when  hop  is  mixed  with  strong  beer  wort  and  boiled  for  many  hours,  it  can  still 
impart  a  very  considerable  degree  of  its  flavor  to  weaker  beer.  By  mere  infusion  ia 
hot  beer  or  water,  without  boiling,  the  hop  loses  very  little  of  its  soluble  principles. 
The  tannin  of  the  hop  combines,  as  we  have  said,  with  the  vegetable  albumen  of  the 
barley,  and  helps  to  clarify  the  liquor.  Should  there  be  a  deficiency  of  albumen  and 
gluten,  in  consequence  of  the  mashing  having  been  done  at  such  a  heat  as  to  have  coagu- 
lated them  beforehand,  the  defect  may  be  remedied  by  the  addition  of  a  liille  gelatine  to 
the  wort  copper,  either  in  the  form  of  calf's  foot,  or  of  a  little  isinglass.  If  the  hops  be 
boiled  in  the  wort  for  a  longer  period  than  5  or  6  hours,  they  lose  a  portion  of  their  fine 
flavor;  but  if  their  natural  flavor  be  rank,  a  little  extra  boiling  improves  it.  Many  brew- 
ers throw  the  hops  in  upon  the  surface  of  the  boiling  wort,  and  allow  them  to  swim  there 
for  some  time,  that  the  steam  may  penetrate  them,  and  open  their  pores  for  a  complete  so- 
lution of  their  principles  when  they  are  pushed  down  into  the  liquor.  It  is  proper  to  add 
the  hops  in  considerable  masses,  because,  in  tearing  them  asunder,  some  of  the  lupuline 
powder  is  apt  to  be  lost. 

The  quantity  of  hop  to  be  added  to  the  wort  varies  according  to  the  strength  of  the 
'>eer,  the  length  of  time  it  is  to  be  kept,  or  the  heat  of  the  climate  where  it  is  intended 
to  be  sent.  For  strong  beer,  4^  lbs.  of  hops  are  required  to  a  quarter  of  malt,  when  it 
is  to  be  highly  aromatic  and  remarkably  clear.  For  the  stronger  kinds  of  ale  and 
porter,  the  rule,  in  England,  is  to  take  a  pound  of  hops  for  every  bushel  of  malt,  or  8  lbs. 
to  a  quarter.  Common  beer  has  seldom  more  than  a  quarter  of  a  pound  of  hops  to  the 
bushel  of  malt. 

It  has  been  attempted  to  form  an  extract  of  hops  by  boiling  m  covered  vessels,  so  as 
not  to  lose  the  oil,  and  to  add  this  instead  of  the  hop  itself  to  the  beer.  On  the  great 
scale  this  method  has  no  practical  advantage,  because  the  extraction  of  the  hop  is  per- 
fectly accomplished  during  the  necessary  boiling  of  the  wort,  and  because  the  hop  ope- 
rates very  beneficially,  as  we  have  explained,  in  clarifying  the  beer.  Such  an  extract, 
moreover,  coulJ  be  easily  adulterated. 

Of  the  Coolers. — The  contents  of  the  copper  are  run  into  what  is  called  the  hop- 
back,  on  the  upper  part  of  which  is  fixed  a  drainer,  to  keep  bac'i  the  hops.  The 
pump  is  placed  in  the  hop-back,  for  the  purpose  of  raising  the  wort  to  the  coolers, 
usually  placed  in  an  airy  situation  upon  the  top  of  the  brewery.  Two  coolers  are 
indispensable  when  we  make  two  kinds  of  beer  from  the  same  brewing,  and  even  lo 
single  brewings,  called  gyles,  if  small  beer  is  lo  be  made.  One  of  these  coolers  ought 
to  be  placed  above  the  level  of  the  other-  As  it  is  of  great  consermence  to  cool  the 
worts  down  to  the  fermenting  pitch  as  fast  as  possible,  various  contrivances  have  been 
made  for  effecting  this  purpose.  The  common  c(X>ler  is  a  square  wooden  cistern,  about 
6  inches  deep,  and  of  such  an  extent  of  surface  that  the  whole  of  one  boil  may  only 
occupy  2  inches,  or  thereabouts,  of  depth  in  it.  For  a  quantity  of  wort  equal  to  about 
15D0  gallons  its  area  should  be  at  least  54  feet  long  and  20  feet  wide.    The  seams  of 


the  cooler  must  be  made  perfectly  water-tight  and  smooth,  so  that  no  liquor  may  lodge  in 
them  when  they  are  emptied.  The  utmost  cleanliness  is  required,  and  an  occasional 
sweetening  with  lime-water. 

The  hot  wort  reaches  the  cooler  at  a  temperature  of  from  200°  to  208°,  according  to 
the  power  of  the  pump.  Here  it  should  be  cooled  to  the  proper  temperature  for  the 
fermenting  tun,  which  may  vary  from  54°  to  64°,  acccrding  to  circumstances.  The 
refrigeration  is  accomplished  by  the  evaporation  of  a  porJon  of  the  liquor:  it  is  more 
ra]iid  in  proportion  to  the  extent  of  the  surface,  to  the  low  temperature,  and  the  dryness 
of  the  atmosphere  surrounding  the  cooler.  The  renewal  of  a  body  of  cool  dry  air  by 
the  agency  of  a  fan,  may  be  employed  with  great  advantage.  The  cooler  itself  must 
be  so  placed  that  its  surface  shall  be  freely  exposed  to  the  prevailing  wind  of  the  district, 
and  be  as  free  as  possible  from  the  eddy  of  surrounding  buildings.  It  is  thought  by  many 
that  the  agitation  of  the  wort  during  its  cooling  is  hurtful.  Were  the  roof  made  move^ 
able,  so  that  the  wort  could  be  readily  exposed,  in  a  clear  night,  to  the  aspect  of  the  sky, 
it  would  cool  rapidly  by  evaporation,  on  the  principles  explained  by  Dr.  Wells,  in  his 
"  Essay  on  Dew." 

When  the  cooling  is  effected  by  evaporation  alone,  the  temperature  falls  very  slowly, 
even  in  cold  air,  if  it  be  loaded  with  moisture.  But  when  the  air  is  dry,  the  evaporation 
is  vigorous,  and  the  moisture  exhaled  does  not  remain  incumbent  on  the  liquor,  as  in 
damp  weather,  but  is  diffused  widely  in  space.  Hence  we  can  understand  how  wort 
cools  so  rapidly  in  the  spring  and  autumn,  when  the  air  is  generally  dry,  and  even  more 
quickly  than  in  winter,  when  the  air  is  cooler,  but  loaded  with  moisture.  In  fact,  the 
cooling  process  goes  on  better  when  the  atmosphere  is  from  50°  to  55°,  than  when  it  falls 
to  the  freezing  point,  because  in  this  case,  if  the  air  be  still,  the  vapors  generated  remain 
on  the  surface  of  the  liquor,  and  prevent  further  evaporation.  In  summer  the  cooling 
can  take  place  only  during  the  night. 

In  consequence  of  the  evaporation  during  this  cooling  process,  the  bulk  of  the  worts 
is  considerably  reduced ;  thus,  if  the  temperature  at  the  beginning  was  208°,  and  if  it 
be  at  the  end  64°,  the  quantity  of  water  necessary  to  be  evaporated  to  produce  this 
refrigeration  would  be  nearly  |  of  the  whole,  putting  radiation  and  conduction  of  heat 
out  of  the  question.  The  effect  of  this  will  be  a  proportional  concentration  of  the 
beer. 

The  period  of  refrigeration  in  a  well-constructed  cooler,  amounts  to  6  or  7  hours  in 
favorable  weather,  but  to  12  or  15  in  other  circumstances.  The  quality  of  the  beer  is 
much  improved  by  shortening  this  period ;  because,  in  consequence  of  the  great  surface 
which  the  wort  exposes  to  the  air,  if:  readily  absorbs  oxsyen,  and  passes  into  the  acetous 
fermentation  with  the  production  of  various  mouldy  spots ;  an  evil  to  which  ill-hopped 
beer  is  particularly  liable.  Various  schemes  have  been  contrived  to  cool  wort,  bv  trans- 
mitting it  through  the  convolutions  of  a  pipe  immersed  in  cold  water.  The  best  plan 
is  to  expose  the  hot  wort  for  some  hours  freely  to  the  atmosphere  and  the  cooler,  when 
the  loss  of  heat  is  most  rapid  by  evaporation  and  other  means,  and  when  the  tempera- 
ture falls  to  100°,  or  thereby,  lo  transmit  the  liquor  through  a  zig-zag  pipe,  laid  almost 
horizontally  in  a  trough  of  cold  water.  The  various  methods  described  under  Refrif^era- 
ior  are  more  complex,  but  they  may  be  practised  in  many  situations  with  considerable  ad- 
vantage. 

Whilst  the  wort  reposes  in  the  cooler,  it  lets  fall  a  slight  sediment,  which  consists 
partly  of  fine  flocks  of  coagulated  albumen  combined  with  tannin,  and  partly  of  starch, 
which  had  been  dissolved  at  the  high  temperature,  and  separates  at  the  lower.  The  wort 
should  be  perfectly  limpid,  for  a  muddy  liquor  never  produces  transparent  beer.  Such 
beer  contains,  besides  mucilaginous  sugar  and  gum,  usually  some  starch,  which  even  re- 
mains afier  the  fermentation,  and  hinders  its  clarifyins,  and  gives  it  a  tendency  to  sour. 
i!f  7^^^  contains  more  starch  the  hotter  it  has  been  mashed,  the  less  hops  have  been 
added,  and  the  shorter  time  it  has  been  boiled.  The  presence  of  starch  in  the  wort  mav 
be  made  manifest  by  adding  a  little  solution  of  iodine  in  alcohol  to  it,  when  it  will  be'- 
come  immediately  blue.  We  thus  see  that  the  tranquil  cooling  of  wort  in  a  proper  ves- 
sel has  an  advantage  over  cooling  it  rapidly  bv  a  refrigeratory  apparatus.  When  the 
wort  is  sufficiently  cool,  it  is  let  down  into  the  fermenting  tun.  In  this  transfer  the  cool- 
ing might  be  carried  several  degreo:*  lower,  were  the  wort  made  to  pass  down  through  p 
tube  enclosed  m  another  tube,  along  which  a  stream  of  cold  water  is  flowing  in  the  cppo- 
site  direction,  as  we  have  described  in  the  sequel  of  Acetic  acid.  These  ft.rmenting  tuns 
are  commonly  called  gyle-tuns,  or  working  tuns,  and  are  either  square  or  circular,  the 
latter  being  preferable  on  many  accounts. 

IV.  0/the  Fermentation —in  the  great  London  breweries,  the  size  of  these  fermenting 
tuns  is  such  that  they  contain  from  1200  to  1500  barrels.  The  quantity  of  wort 
intrcKluced  at  a  time  must,  however,  be  considerably  less  than  the  capaciiv  of  the  vessel 
to  allow  room  for  the  head  of  yeast  which  rises  during  the  process;  if  the  vessel  be 
cylindrical,  this  head  is  proportional  to  the  depth  of  the  worts.    In  certain  kinds  of 


138 


BEER. 


BEER. 


139 


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! ; 


i    :! 


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t     :i 


fermentation,  it  may  rise  to  a  third  of  that  depth.  In  general,  the  fermentation  proceeds* 
more  uniformly  and  constantly  in  large  masses,  because  they  are  little  influenced  by  vi- 
cissitudes  of  temperature  ;  smaller  vessels,  on  the  other  hand,  are  more  easily  handled. 
The  general  view  of  fermentation  will  be  found  under  that  title ;  I  shall  here  make  a 
few  remarks  on  what  is  peculiar  lo  beer.  During  the  fermentation  of  wort,  a  portion 
of  its  saccharine  matter  is  converted  into  alcohol,  and  wort  thus  changed  is  beer.  It  is 
necessary  that  this  conversion  of  the  sugar  be  only  partial,  for  beer  which  contains  no 
undecomposed  sugar  would  soon  turn  sour,  and  even  in  the  casks  its  alcohol  undergoes 
a  slow  fermentation  into  vinegar.  The  amount  of  this  excess  of  sugar  is  greater  in 
proportion  to  the  strength  of  the  wort,  since  a  certain  quantity  of  alcohol,  already 
formed,  prevents  the  operation  of  the  ferment  on  the  remaining  "vort.  Temperature  has 
the  greatest  influence  upon  the  fermentation  of  wort.  A  temperature  of  from  55°  to  60" 
of  the  liquor,  when  that  of  the  atmosphere  is  55°,  is  most  advantageous  for  the 
commencement.  The  warmth  of  the  wort  as  it  comes  into  the  g)'le-tun  must  be  modi- 
fied by  that  of  the  air  in  the  apartment.  In  winter,  when  this  apartment  is  cold,  the 
wort  should  not  be  cooled  under  64°  or  60°,  as  in  that  case  the  fermentation  would  be 
tedious  or  interrupted,  and  the  wort  liable  to  spoil  or  become  sour.  In  summer,  when 
the  temperature  of  the  place  rises  to  above  75°,  the  wort  should  be  cooled,  if  possible, 
down  to  65°,  for  wliich  purpose  it  should  be  let  in  by  the  system  of  double  pipes,  above 
mentioned.  The  liigher  the  temperature  of  the  wort,  the  sooner  will  the  fermentation 
begin  and  end,  and  the  less  is  it  in  our  power  to  regulate  its  progress.  The  expert 
brewer  must  steer  a  middle  course  between  these  two  extremes,  which  threaten  to  de- 
stroy his  labors.  In  some  breweries  a  convoluted  pipe  is  made  to  traverse  or  go  round 
the  sides  of  the  gyle-tun,  through  which  warm  water  is  allowed  to  flow  in  winter,  and 
cold  in  summer,  so  as  to  modify  the  temperature  of  the  mass  to  the  proper  fermenting 
pitch.  If  there  be  no  contrivance  of  this  kind,  the  apartment  may  be  cooled  in  summer, 
by  suspending  wet  canvass  opposite  the  windows  in  warm  weather,  and  kindling  a  small 
Slove  within  it  in  cold. 

When  the  wort  is  discharged  into  the  gyle-tun,  it  must  receive  its  dose  of  yeast,  which 
has  been  previously  mixed  with  a  quantity  of  the  wort,  and  left  in  a  warm  place  till  it 
has  begun  to  ferment.  This  mixture,  called  lobb,  is  then  to  be  put  into  live  tun,  and  stir- 
red well  through  the  mass.  The  yeast  should  be  taken  from  similar  beer.  Its  quantity 
must  depend  upon  the  temperature,  strength,  and  quantity  of  the  wort.  In  general,  one 
gallon  of  yeast  is  sufficient  to  set  100  gaUons  of  wort  in  complete  fermentation.  An  ex- 
cess of  yeast  is  to  be  avoided,  lest  the  fermentation  should  be  too  violent,  and  be  finished 
in  less  than  the  proper  period  of  6  or  8  days.  More  yeast  is  required  in  winter  than  in 
summer;  for,  at  a  temperature  of  50°,  a  double  quantity  may  be  used  to  that  at  68°. 

Six  or  eight  hours  after  adding  the  yeast,  the  tun  being  meanwhile  covered,  the  fer- 
mentation becomes  active  :  a  white  milky-looking  froth  appears,  first  on  the  middle,  and 
spreads  gradually  over  the  whole  surface ;  but  continues  highest  in  the  middle,  forming 
a  frothy  elevation,  the  height  of  which  increases  with  the  progress  of  the  fermentation, 
and  whose  color  gradually  changes  to  a  bright  brown,  the  result,  apparently,  of  the  oxy- 
dation  of  the  extractive  contained  in  this  yeasty  top.  This  covering  screens  the  wort 
from  the  contact  of  the  atmospherical  air.  During  this  time,  there  is  a  perpetual  disen- 
gagement of  carbonic  acid  gas,  which  is  proportional  to  the  quantity  of  sugar  converted 
into  alcohol.  The  warmth  of  the  fermenting  liquid  increases  at  the  same  time,  and  is  at 
a  maximum  when  the  fermentation  has  come  to  its  highest  point.  This  increase  of 
temperature  amounts  to  from  9°  to  14°  or  upwards,  and  is  the  greater  the  more  rapid  the 
fermentation.  But  in  general,  the  fermentation  is  not  allowed  to  proceed  so  far  in  the 
gyle-tun,  for  after  it  is  advanced  a  lillle  way,  the  beer  is  cleansedy  that  is,  drawn  off  into 
other  vessels,  which  are  large  barrels  set  on  end,  with  large  openings  in  their  top,  fur- 
nished with  a  sloping  tray  for  discharging  an  excess  of  yeast  into  the  wooden  trough,  in 
which  the  stillions  stand.  These  stillions  are  placed  in  communication  with  a  stcre-tub, 
which  keeps  them  always  full,  by  hydrostatic  pressure,  so  thai  the  head  of  yeast  may 
spontaneously  flow  over,  and  keep  the  body  of  liquor  in  the  cask  clean.  This  apparatus 
will  be  explaineJ  in  describing  the  brewery  plant.     See  the  Jipuresy  infra. 

It  must  be  observed,  that  the  quantity  of  yeast,  and  the  heal  of  fermentation,  differ 
foi  every  difl'erent  quality  of  beer.  For  mild  ale,  when  the  fermentation  has  reached  75° 
its  first  flavor  begins;  at  80°  the  flavor  increases;  at  85°  it  approaches  the  high 
flavor;  at  90°  it  is  high;  but  it  may  be  carried  to  100°  and  upwards,  for  particular 
purposes.  A  wort  of  301bs.  per  barrel  (sp.  gr.  1'088),  ought  to  increase  about  15*, 
so  that  in  order  to  arrive  at  80°,  it  should  be  set  at  65°.  The  quantity  of  yeast  for  such 
an  ale  should  be  from  2  to  3  lbs.  per  barrel.  The  higher  Ihe  heat,  the  less  yeast  is  ne- 
cessary. If  the  heat  of  the  fermeniatiuu  should  at  any  time  fall,  it  must  be  raised  by  a 
oupply  of  fresh  yeast,  well  stirred  in;  but  this  practice  is  not  advisable  in  general, 
because  rousing  the  worts  in  the  gyle-tun  is  apt  to  communicate  a  rank  flavor  of  yeast 
to  the  ale.     It  is  the  practice  of  many  experienced  brewers  to  look  every  2  hours  into  the 


pyle-tun,  chiefly  with  the  view  of  obserx'^ing  the  progress  of  the  heat,  which  is  low  at 
first,  but  afterwards  often  increases  half  a  degree  per  hour,  and  subsequently  decline?,  as 
the  fermentation  approaches  its  conclusion,  till  at  length  the  heat  becomes'  uniform,  or 
sometimes  decreases,  before  the  fermentation  is  finished,  especially  where  the  quantity 
operated  upon  is  small. 

Some  brewers  recommend,  when  the  fermentation  is  carried  to  its  utmost  period,  to  add 
about  7  lbs.  of  wheat  or  bean  flour  to  a  gyle-tun  of  25  or  30  barrels,  at  the  time  of  dean- 
sivgy  so  as  to  quicken  the  discharge  of  the  yeast,  by  disengagement  cf  more  carbonic  acid. 
The  flour  should  be  whisked  up  in  a  pail,  with  some  of  the  beer,  till  the  lumps  are  bro- 
ken, and  then  poured  in.  By  early  cleansing,  the  yeast  is  pieserved  longer  in  a  state 
pr<iper  for  a  perfect  fermentation  than  by  a  contrary  practice. 

For  old  ale,  which  is  to  be  long  kept,  the  heat  of  the  fomentation  should  not  exceed 
75°,  but  a  longer  time  is  required  to  complete  the  fermentation  and  ensure  the  future 
good  flavor  of  the  ale. 

For  poiter,  the  general  practice  is,  to  use  from  4  to  4^  lbs.  of  hops  per  barrel  for  keep- 
ing; though  what  is  termed  mild  or  mixing  porter,  has  not  more  than  3  or  2|  lbs.  The 
heat  of  fermentation  must  not  exceed  70°,  and  begin  about  60°.  If  the  heat  tend  to  in- 
crease much  above  that  pitch  in  the  gyle-tun,  the  porter  should  be  cleav.sed,  by  means  of 
the  siillims.  At  this  period  of  the  fermentation,  cate  should  be  taken  that  the  s^weetness 
of  the  malt  be  removed,  for  which  purpose  more  yeast  may  be  ised  than  with  any  other 
beer  of  the  same  strength.  The  quantity  is  from  3  to  4  lbs.  per  barrel,  lousins  the  wort 
in  the  gyle  tun  every  2  hours  in  the  day-time. 

When  the  plan  of  cleansing  casks  is  not  employed,  the  yeast  is  removed  from  the 
surface  of  the  lermentlng  tun  by  a  skimmer,  and  the  clear  beer  beneath  is  then  diawn 
ofl'  into  the  ripening  tuns,  called  siore-va/s,  in  which  it  is  mixed  up  with  difltrent  brew- 
ings, to  suit  the  taste  of  the  customers.  This  transfer  must  take  i  lace  whenever  the 
extrication  of  carbonic  acid  has  neaily  ceased;  lest  the  alcohol  foimed  should  dissolve 
some  of  the  floatins  yeast,  acquire  thereby  a  disagreeable  taste,  and  pass  i)artially  into 
the  acetous  state. 

In  this  process,  during  the  formation  of  vinous  spirit  at  the  expense  of  the  suear  the 
albumen  and  gluten  diffused  through  the  beer,  being  acted  upon  by  the  alcchd,  become 
insoluble;  one  portion  of  them  is  buoyed  to  the  top  with  the  carbonic  acid  gas,' to  form 
the  frothy  yeast;  and  another  portion  falls  to  foim  the  bottom  barm.  Thelbimer  con- 
sists of  the  same  materials  as  the  wort,  with  a  laige  proportion  of  gluten,  wl  ich  forms 
its  active  constituent;  the  latter  is  a  peculiar  deposite,  consistine  of  tliesamej-luten  mixed 
with  the  various  dense  impurities  (if  the  wort,  and  nay  be  also  used  as  a  fetmcnt  but  is 
cruder  than  the  floating  yeast.  The  amount  of  yeast  is  proportional  to  the  activity  of  the 
fermentation,  or  extrication  of  carbonic  acid  gas,  as  also  to  the  heat  of  the  ma«^hin£r  pro- 
cess, and  the  quantity  of  starch  or  flour  unaltered  by  germination.  Pale  malt  afli'rds 
usually,  more  yeast  than  malt  highly  kilned.  When  the  veast  becom#^s  excc^ive  from 
too  violent  fermentation,  it  should  be  skimmed  of!  from  time  to  time,  which  wiD  tend  to 
cool  the  liquor  and  moderate  the  intestine  changes. 

After  the  beer  is  let  down  into  the  close  store-tuns  in  the  cellar,  an  obscure  fermenta 
tion  goes  on,  for  a  considerable  period,  in  its  body,  which  increases  its  spirifious  nreneth 
and  keeps  up  m  it  a  constant  impregnation  of  carbonic  acid  gas,  so  as  to  render  it  hxfU 
and  agreeable  to  the  taste,  when  it  is  casked  (,ff  for  sale.     It  would  appear  that  beer  is 
never  stationary  in  quality,  while  it  is  contained  in  the  tuns;  for  the  moment  when  it 
ceases  to  improve  by  the  decomposition  of  its  residuary  sugar,  it  beeins  to  de-enerate 
into  vinegar.     This  result  may  be  produced  either  by  the  exhaustion  of  the  saccharine 
or  by  the  fermentative  matter.     The  store  cellar  should  therefore  be  under  ground  free 
from  alternations  of  temperature,  vibrations  of  carriages,  and  as  cool  as  possible      In  the 
great  London    breweries  the  fermentation  is  rendered  very  complete  in^Jhe  clean^ine 
butts;  so  that  a  slow  and  steady  ripening  is  ensured  in  the  great  store-tuns      The  -vie 

rffi^L^rp^hTlhr^^'"'  ''^  '^^"^""'^"  *°  ^^  ^^^^^^^^-^^  -^^^  -^^^ 

V  Of  ripening  different  kinds  of  BEER.-The  varieties  of  beer  depend  either  upon 
the  d.flerence  of  iheu-  materials,  or  ft  om  a  different  management  of  the  brewing  proceT^ 

With  regard  to  the  materials,  beers  differ  in  the  proportion  of  their  maM  h^n^nd 
water;  and  i.  the  different  kinds  of  malt  or  other%rain.  T^he  da4  cV  Sle  or 
small  beers,  all  those  sorts  may  be  referred  whose  specific  gravity  does  rot  exceed  1  025 
which  contain  about  6  per  cent,  of  malt  extract,  or  nearly ^18  po!indspr  barrel  ^  Bee^ 
of  middling  strength  maybe  reckoned  those  between  the  deisiiy  of  1-025  and  1040^ 
which  contain  at  the  average  7  per  cent,  or  25  pounds  per  barrel.  The  latter  mav 
be  made  with  400  quarters  of  malt  to  1500  barSs  of  beer.  Stronger  beefs  ha^^ 
specific  gravity  of  from  1-050  to  1-080,  and  take  from  45  to  75  quarU  of  ma  t  to 
the  same  quantity  cf  beer.  The  strongest  beer  found  in  the  market  is  some  of  the 
English  and  Scotch  ales,  for  which  from  18  to  27  quarters  of  mall  ar'  lake^  forl^ 


140 


BEER. 


BEER. 


141 


If 


'I 


'      III 


I'  ii 


, 


gallons  of  beer.  Good  porter  requires  from  16  to  18  qnarters  for  that  quantity.  Be€W 
are  sometimes  made  with  the  addition  of  other  farinaceous  matter  to  the  malt ;  but 
when  the  latter  constitutes  the  main  portion  of  the  grain,  the  maltin?  of  the  other 
kinds  of  corn  becomes  unnecessary,  for  the  diastase  of  the  barley-malt  changes  the 
starch  into  sugar  during  the  mashing  operation.  Even  with  entirely  raw  grain,  beer 
is  made  in  some  parts  of  the  Continent,  the  brewers  trusting  the  conversion  of  the 
starch  into  sugar  to  the  action  of  the  gluten  alone,  at  a  low  mashing  temperature,  on 
the  principle  of  Saussure's  and  KirchofPs  researches. 

The  color  of  the  beer  depends  upon  the  color  of  the  malt,  and  the  duration  of  the 
boil  in  the  copper.  The  pale  ale  is  made,  as  we  have  stated,  from  steam  or  sun-dried 
malt,  and  the  young  shoots  of  the  hop;  the  deep  yellow  ale  from  a  mixture  of  pale 
yellow  and  brown  malt;  and  the  dark  brown  beer  from  well-kilned  and  partly  car- 
bonized malt,  mixed  with  a  good  deal  of  the  pale,  to  give  body.  The  longer  and  more 
stroni^ly  heated  the  malt  has  been  in  the  kiln,  the  less  weight  of  extract,  cater  is  paribus, 
does  it  afford.  In  making  the  fine  nild  ales,  high  temperatures  ought  to  be  avoided, 
and  the  yeast  ought  to  be  skimmed  ovf,  or  allowed  to  flow  very  readily  from  its  top,  by 
means  of  the  cleansing  butt  system,  so  that  little  ferment  being  left  in  it  to  decompose 
the  rest  of  the  sugar,  the  sweetness  may  remain  unimpaired.  With  regard  to  porter, 
in  certain  breweries,  each  of  the  three  kinds  of  malt  employed  for  it  is  separately 
mashed,  after  which  the  first  and  the  half  of  the  second  wort  is  boiled  along  with  the 
whole  of  the  hops,  and  thence  cooled  and  set  to  ferment  in  the  g>ie-tun.  The  third 
drawn  wort,  with  the  remaining  half  of  the  second,  is  then  boiled  with  the  same  hops, 
saved  by  the  drainer,  and,  after  cooling,  added  to  the  former  in  the  gyle-tun,  when  the 
two  must  be  well  roused  together. 

It  is  obvious,  from  the  preceding  development  of  principles,  that  all  amylaceous  and 
saccharine  materials,  such  as  potatoes,  beans,  turnips,  as  well  as  cane  and  starch  sirup, 
molasses,  &c.,  may  be  used  in  brewing  beer.  When,  however,  a  superior  quality  of 
brown  beer  is  desired,  malted  barley  is  indispensable,  and  even  with  these  substitutes 
a  mixture  of  ii  is  most  advantageous.  The  washed  roots  of  the  common  carrot,  of  the 
red  and  yellow  beet,  or  of  the  potato,  must  be  first  boiled  in  water,  and  then  mashed 
into  a  pulp.  This  pulp  must  be  mixed  with  water  in  the  copper,  along  with  wheaten 
or  oat  meal,  and  the  proper  quantity  of  hops,  then  boiled  during  8  or  9  hours.  This 
wort  is  to  be  cooled  in  the  usual  way,  and  fermented,  with  the  addition  of  yeast. 
A  much  better  process  is  that  now  practised,  on  a  considerable  scale,  at  Strasbourg,  in 
making  the  ale,  for  which  that  city  i-s  celebrated.  The  mashed  potatoes  are  mixed  with 
from  a  twentieth  to  a  tenth  of  their  weight  of  finely  ground  barley  malt,  and  some 
water.  The  mixture  is  exposed,  in  a  water- bath,  to  a  heat  of  160*  F.  for  four  hours, 
whereby  it  passes  into  a  saccharine  state,  and  may  then  be  boiled  with  hops,  cooled,  and 
properly  fermented  into  good  beer. 

Maize,  or  Indian  corn,  has  also  been  employed  to  make  beer ;  but  its  malting  is 
somewhat  difficult  on  account  of  the  rapidity  and  vigor  with  which  its  radicals  and 
plumula  sprout  forth.  The  proper  mode  of  causing  it  to  germinate  is  to  cover  it,  a  few 
inches  deep,  with  common  soil,  in  a  garden  or  field,  and  to  leave  it  there  till  the  bed  is 
covered  with  green  shoots  of  the  plant.  The  corn  must  be  then  lif\ed,  washed,  and 
exposed  to  the  kiln. 

The  Difference  of  the  Fermentation. — ^The  greater  or  less  rapidity  with  which  the 
worts  are  made  to  ferment  has  a  remarkable  influence  upon  the  quality  of  the  beer, 
especially  in  reference  to  its  fitness  for  keeping.  The  wort  is  a  mucilaginous  solution 
in  which  the  yeasty  principles,  eliminated  by  the  fermentation,  will,  if  favored  by 
regular  and  slow  intestine  movements,  completely  rise  to  the  surface,  or  sink  to  the 
bottom,  so  as  to  leave  the  body  fine.  But,  when  the  action  is  too  violent,  these  barmy 
glutinous  matters  get  comminuted  and  dispersed  through  the  liquor,  and  can  never  after- 
wards be  thoroughly  separated.  A  portion  of  the  same  feculent  matter  becomes,  moreover, 
permanently  dissolved,  during  this  furious  commotion,  by  the  alcohol  that  is  generated. 
Thus  the  beer  loses  not  merely  its  agreeable  flavor  and  limpidity,  but  is  apt  to  spoil 
from  the  slightest  causes.  The  slower,  more  regularly  progressive,  and  less  interrupted, 
therefore,  the  fermentation  is,  so  much  better  will  the  product  be. 

Beer,  in  its  perfect  condition,  is  an  excellent  and  healthful  beverage,  combining,  in 
some  measure,  the  virtues  of  water,  of  wine,  and  of  food,  as  it  quenches  thirst,  stimulates, 
cheers,  and  strengthens.  The  vinous  portion  of  it  is  the  alcohol,  proceeding  from  the 
fermentation  of  the  malt  sugar.  Its  amount,  in  common  strong  ale  or  beer,  is  about 
4  per  cent.,  or  four  measures  of  spirits,  specific  gravity  0*825  in  100  measures  of  the 
liquor.  The  best  brown  stout  porter  contains  6  per  cent.,  the  strongest  ale  even  8  per 
cent. ;  but  common  beer  only  one.  The  nutritive  part  of  the  beer  is  the  undecomposed 
gum-sugar,  and  the  starch-gum,  not  changed  into  sugar.  Its  quantily  is  very  variable, 
accordmg  to  the  original  starch  of  the  wort,  the  length  of  the  fermentation,  and  the  ag« 
of  the  beer. 


The  main  feature  of  good  beer  is  fine  color  and  transparency ;  the  production  of 
which  is  an  object  of  great  interest  to  the  brewer.  Attempts  to  clarify  it  in  the  cask 
seldom  fail  to  do  it  harm.  The  only  thing  that  can  be  used  with  advantage  for  fimng 
foul  or  muddy  beer,  is  isinglass.  For  porter,  as  commonly  brewed,  it  is  frequently  had 
recourse  to.  A  pound  of  good  isinglass  will  make  about  12  gallons  o^  finings.  It  is 
cut  into  slender  shreds,  and  put  into  a  tub  with  as  much  vinegar  or  hard  beer  as  will 
cover  it,  in  order  that  it  may  swell  and  dissolve.  In  proportion  as  the  solution  proceeds, 
more  beer  must  be  poured  upon  it,  but  it  need  not  be  so  acidulous  as  the  first,  because, 
when  once  well  softened  by  the  vinegar,  it  readily  dissolves.  The  mixture  should  be 
frequently  agitated  with  a  bundle  of  rods,  till  it  acquires  the  uniform  consistence  of  thin 
treacle,  when  it  must  be  equalized  still  more  by  passing  through  a  tammy  cloth,  or  a 
sieve.  It  may  now  be  made  up  with  beer  to  the  proper  measure  of  dilution.  The 
quantity  generally  used  is  from  a  pint  to  a  quart  per  barrel,  more  or  less,  according  to 
the  foulness  of  the  beer.  But  before  putting  it  into  the  butt,  it  should  be  diflfused 
through  a  considerable  volume  of  the  beer  with  a  whisk,  till  a  frothy  head  be  raised 
upon  it.  It  is  in  this  state  to  be  poured  into  the  cask,  briskly  stirred  about ;  afler 
which  the  cask  must  be  bunged  down  for  at  least  24  hours,  when  the  liquor  should  be 
limpid.  Sometimes  the  beer  will  not  be  improved  by  this  treatment ;  but  this  should 
be  ascertained  beforehand,  by  drawing  off  some  of  the  beer  into  a  cylindric  jar  or  vial, 
and  adding  to  it  a  little  of  the  finings.  After  shaking  and  setting  down  the  glass,  we 
shall  observe  whether  the  feculencies  begin  to  collect  in  flocky  parcels,  which  slowly 
subside ;  or  whether  the  isinglass  falls  to  the  bottom  without  making  any  impression 
upon  the  beer.  This  is  always  the  case  when  the  fermentation  is  incomplete,  or  a  se- 
condary decomposition  has  begun.  Mr.  Jackson  has  accounted  for  this  clarifying  eflfect 
of  isinglass  in  the  following  way. 

The  isinglass,  he  thinks,  is  first  of  all  rather  diffused  mechanically,  than  chemically 
dissolved,  in  the  sour  beer  or  vinegar,  so  that  when  the  finings  are  put  into  the  foul  beer, 
the  gelatinous  fibres,  being  set  free  in  the  liquor,  attract  and  unite  with  the  floating  fecu- 
lencies, which  before  this  union  were  of  the  same  specific  gravity  with  the  beer,  and 
therefore  could  not  subside  alone ;  but  having  now  acquired  additional  weight  by  the 
coating  offish  glue,  precipitate  as  a  flocculent  magma.  This  is  Mr.  Jackson's  explana- 
tion ;  to  which  I  would  add,  that  if  there  be  the  slightest  disengagement  of  carbonic 
acid  gas,  it  will  keep  up  an  obscure  locomotion  in  the  particles,  which  will  prevent  the  said 
light  impurities,  either  alone  or  when  coated  with  isinglass,  from  subsiding.  The  beer 
is  then  properly  enough  called  stubborn  by  the  coopers.  Bui  the  true  theory  of  the  action 
of  isinglass  is,  that  the  tannin  of  the  hops  combines  with  the  fluid  gelatine,  and  forms  a 
flocculent  mass,  which  envelopes  the  muddy  particles  of  the  beer,  and  carries  them  to  the 
bottom  as  it  falls,  and  forms  a  sediment.  When,  aAer  the  finings  are  poured  in,  no 
proper  precipitate  ensues,  it  may  be  made  to  appear  by  the  addition  of  a  little  decoction 
of  hop. 

Mr.  Richardson,  the  author  of  the  well-known  brewer's  saccharometer,  gives  the 
following  as  the  densities  of  different  kinds  of  beer  : — 


Beer. 

Pounds  per  Barrel. 

Specific  Giavity. 

Burton  ale,  1st  sort      -        -        - 

40  to  43 

1-111  to  M20 

2d  ditto  - 

35  to  40 

1«097  to  Mil 

3d  ditto      -        -        - 

28  to  33 

1-077  to  1-092 

Common  ale    - 

25  to  27 

1-070  to  1-073 

Ditto  ditto 

21 

1-058 

Porter,  common  sort 

18 

1-050 

Ditto,  double       -        -        -        - 

10 

1-055 

Ditto,  brown  stout    -        -        - 

S3 

1-064 

Ditto,  best  brown  stout 

26 

1-072 

Common  small  beer  -        -        • 

6 

1-014 

Good  table  beer  -        -        -        - 

12  to  14 

1-033  to  1  039 

0/  Returns  or  Malt  Residuums. —  When  small  beer  is  brewed  afler  ale  or  porter,  only 
one  mash  is  to  be  made  ;  but  where  this  is  not  done,  there  may  be  two  mashes,  in  order 
to  economize  malt  to  the  utmost.  We  may  let  on  the  water  at  160°  or  165°,  in  any 
convenient  quantity,  infuse  for  an  hour  or  thereby,  then  run  it  off,  and  pump  into  the 
copper,  putting  some  hops  into  it,  and  causing  it  to  boil  for  an  instant;  when  it  may  be 
transferred  to  the  cooler.  A  second  mash  or  return  may  be  made  in  the  same  manner, 
but  at  a  heat  5°  lower ;  and  then  disposed  of  in  the  boiler  with  some  hops,  which  may 
remain  in  the  copper  during  the  night  at  a  scalding  heat,  and  may  be  discharged  intfc 
the  cooler  in  the  morning.  These  two  returns  are  to  be  let  down  into  the  under- 
back  immediately  before  the  next  brewing^  and  thence  heated  in  the  copper  for  the  next 


J  '• 

k 


142 


BEER. 


mashin-  of  fresh  malt,  instead  of  hot  water,  commonly  called  liquoTy  in  the  breweries. 
BS^wancTmuTt  bi  made,  in  the  calculation  of  the  worts,  for  the  quantity  of  ferment- 
able  matter  in  these  two  returns.  The  nelt  aggregate  savmg  is  estimated  from  the 
SIvitTrtheret^ntrn  when  cold  in  t^  cooler  A  slight  economy  is  also  made  in 
Se  extra  boiling  of  the  used  hops.  The  lapse  of  a  day  or  two  between  the  consecutive 
brewings  iTno  Objection  to  the  method  of  retur.^,  because  they  are  too  weak  m  saccha. 
rinp  matter  to  run  any  risk  of  fermentation.  ,  ,        .      .v 

In  concluslo^  it  may  be  remarked  that  Mr.  Richardson  somewha  underrates  the 
irravitv  of  ^rter  which  is  now  seldom  under  201bs.  per  barrel.  The  criterion  lor  trans- 
^rln'  frort^e  btiuV't o  the  cleansing  butts  is  the  attenuation  caused  by  the  produc 
tion  of  a  cohol  in  the  beer :  when  that  has  fallen  to  lOlbs.  or  1  libs.,  which  it  usua  y  does 
111  48  hou7s  the  cleansing  process  is  commenced.  The  heat  is  at  this  time  generally  7o% 
if  it  was  pitched  at  65" ;  for  the  heat  and  the  attenuation  go  hand  in  hand. 

About  thirty  years  ago,  it  was  customary  for  the  London  brewers  of  porter  to  keep 
immense  stocks  of  it  for  eighteen  months  or  two  years,  with  the  view  of  improving  its 
oualitv     The  beer  was  pumped  from  the  cleansing  butts  mto  store-vats,  holdmg  from 
twenty  to  twenty-five  gvles  or  brewings  of  several  hundred  barrels  each.    The  store-vats 
had  commonly  a  capacity  of  5000  or  6000  barrels;  and  a  few  were  double,  and  one  was 
trebK  this  size.     The  porter,  during  its  long  repose  m  these  vats,  became  hne,  and  by 
obscure  fermentation  its  saccharine  mucUage  was  nearly  all  converted  into  vinous  liquor, 
and  dissipated  in  carbonic  acid.     Its  hop-bitter  was  also  in  a  great  degree  decomposed. 
Good  hard  beer  was  the  boast  of  the  day.     This  was  sometimes  softened  by  the  publican, 
by  the  addition  of  some  mild  new-brewed  beer.     Of  late  years,  the  taste  of  the  metro- 
polis has  undergone  such  a  complete  revolution  in  this  respect,  that  nothing  but  the 
mildest  porter  will  now  go  down.     Hence,  sLx  weeks  is  a  long  period  for  beer  to  be  kept 
in  London :  and  much  of  it  is  drunk  when  only  a  fortnight  old.     Ale  is  for  the  simie  rea- 
son come  greatly  into  vogue;   and  the  two  greatest  porter  houses,  Messrs.  Barclay, 
Perkins   &  Co.,  and  Truman,  Hanbury,  &  Co.,  have  become  extensive  and  successful 
brewers  of  mild  ale,  to  please  the  changed  palate  of  their  customers. 

We  shall  add  a  few  observations  upon  the  brewing  of  Scotch  ale.  This  beverage  is 
characterized  by  its  pale  amber  color,  and  its  mUd  balsamic  flavor.  The  bitterness  of 
the  hop  is  so  mellowed  with  the  malt  as  not  to  predominate.  The  ale  of  Preston  Pans 
is  in  fact,  the  best  substitute  for  wine  which  barley  has  hitherto  produced.  The  low 
temperature  at  which  the  Scotch  brewer  pitches  his  fermenting  tun  restricts  his  labors 
to  the  colder  months  of  the  year.  He  does  nothing  during  four  of  the  summer  months. 
He  is  extremely  nice  in  selecting  his  malt  and  hops;  the  former  being  made  from  the  best 
English  barley,  and  the  latter  being  the  growth  of  Famham  or  East  Kent.  The  yeast  is 
carefuUy  looked  after,  and  measured  into  the  fermenting  tun  m  the  proportion  ol  one 

gallon  to  240  gallons  of  wort.  ,    ^  .        ...  v  ♦  ♦»,- 

Only  one  mash  is  made  by  the  Scotch  ale  brewer,  and  that  pretty  strong ;  but  he 
malt  is  exhausted  by  eight  or  ten  successive  sprinklings  of  liquor  (hot  water)  over  the 
goods  (malt),  which  are  termed  in  the  vernacular  tongue,  ^arge*.     These  waterings 
percolate  through  the  malt  on  the  mash-tun  bottom,  and  extract  as  inuch  of  the  saccharine 
matter  as  may  be  sufficient  for  the  brewing.    By  this  simple  method  much  higher  specific 
gravities  may  be  obtained  than  would  be  practicable  by  a  second  mash.    W  ith  malt,  the 
infusion  or  saccharine  fermentation  of  the  diastase  is  finished  with  the  first  mash;  and 
nothing  remains  but  to  wash  away  from  the  goods  the  matter  which  that  process  has 
rendered  soluble.    It  will  be  found  on  trial  that  20  barrels  of  wort  drawn  from  a  cerlam 
quantity  of  malt,  by  two  successive  mashings,  wiU  not  be  so  rich  m  fermentable  matter 
as  20  barrels  extracted  by  ten  successive  sparges  of  two  barrels  each.     1  he  grains 
always  remain  soaked  with  wort  like  that  just  drawn  off,  and  the  total  residual  quantity 
IS  th^ee  fourths  of  a  barrel  for  every  quarter  of  malt.    The  gravity  of  this  residua  wort 
will  on  the  first  plan  be  equal  to  that  of  the  second  mash ;  but  on  the  second  plan,  it 
will  be  equal  only  to  that  of  the  tenth  sparge,  and  will  be  more  attenuated  in  a  very  high 
geometrical  ratio.    The  only  serious  objection  to  the  sparging  system  is  the  loss  ol  time 
by  the  successive  drainages.     A  mash-tun  with  a  steam  jacket  promises  to  suit  the 
sparging  system  well ;  as  it  would  keep  up  a  uniform  temperature  m  the  goods,  without 
requiring  them  to  be  sparged  with  very  hot  liquor. 

The  first  part  of  the  Scotch  process  seems  of  doubtful  economy;  for  the  mash  liquor  is 
heated  so^hi'-h  as  180°.  After  mashing  for  about  half  an  hour,  or  tiU  every  particle  of 
the  malt  is  thoroughly  drenched,  the  tun  is  covered,  and  the  mLxture  left  to  infuse  about 
three  hours ;   it  is  then  drained  off  into  the  under-back,  or  preferably  mto  the  wort 

*^^fter  this  wort  is  ran  oflT,  a  quantity  of  liquor  (water),  at  ISOP  of  heat,  is  sprinkled 
uniformly  over  the  surlace  of  the  malt;  being  first  dashed  on  a  perforated  circular 
board,  suspended  horizontally  over  the  mash-tun,  wherefrom  it  descends  like  a  shower 


V 


., 


BEER. 


143 


upon  the  whole  of  the  goods.  The  percolating  wort  is  allowed  to  flow  oflT,  by  three  or 
more  small  stopcocks  round  the  circumference  of  the  mash-tun,  to  ensure  the  equal  dif^ 
fusion  of  the  liquor. 

The  first  sparge  being  run  oflT  in  the  course  of  twenty  minutes,  another  similar  one 
is  aflused  ;  and  thus  in  succession  till  the  whole  of  the  drainage,  when  mixed  with  the 
first  mash-wcrt,  constitutes  the  density  adapted  to  the  quality  of  the  ale.  Thus,  the 
strong  worts  are  prepared,  and  the  malt  is  exhausted  either  for  table  beer,  or  for  a 
return^  as  pointed  out  above".  The  last  sparges  are  made  5P  or  6°  cooler  than  the 
first. 

The  quantity  of  hops  seldom  exceeds  four  pounds  to  the  quarter  of  malt.  The  manner 
of  boiling  the  worts  is  the  same  as  that  above  described  ;  but  the  conduct  of  the  fer- 
mentatifin  is  peculiar.  The  heat  is  pitched  at  60°,  and  the  fermentation  continues  from 
a  fortnight  to  three  weeks.  "Were  three  brewings  made  in  the  week,  seven  or  eight 
working  tuns  would  thus  be  in  constant  action ;  and,  as  they  are  usv.iriy  in  one  room, 
and  some  of  them  at  an  elevation  of  temperature  of  15°,  the  apartment  must  be  pro- 
pitious to  fermentation,  however  low  its  heat  may  be  at  the  commencement.  No  more 
yeast  is  used  than  is  indispensable ;  if  a  little  more  be  needed,  ii  is  made  efleclive  by 
rousing  up  the  tuns  twice  a  day  from  the  bottom. 

When  the  progress  of  the  attenuation  becomes  so  slack  as  not  to  exceed  half  a  pound 
in  the  day,  it  is  prudent  to  cleanse,  otherwise  the  top-barm  might  re-enter  the  body  of  the 
beer,  and  it  would  become  ymst-biiten.  When  the  ale  is  cleansed,  the  head,  which  has 
not  been  disturbed  for  seme  days,  is  allowed  to  float  on  the  surface  till  the  whole  of  the 
then  pure  ale  is  drawn  off  into  the  casks.  This  top  is  regarded  as  a  sufiicient  preservative 
against  the  contact  of  the  atmosphere.  The  Scotch  do  not  skim  their  tuns,  as  the  Lon- 
don ale  brewers  commonly  do.  The  Scotch  ale,  when  so  cleansed,  does  not  require  to 
be  set  upon  close  stilllons.  It  throws  off  little  or  no  yeast,  because  the  fermentation 
was  nearly  finished  in  the  tun.  The  strength  of  the  best  Scotch  ale  ranges  between  32 
and  44  pounds  to  the  barrel;  or  it  has  a  specific  gravity  of  from  1-088  to  1-122,  according 
to  the  price  at  which  it  is  sold.  In  a  good  fermentation,  seldom  more  than  a  fourth  of 
the  original  gravity  of  the  wort  remains  at  the  period  of  the  cleansing.  Between  one 
third  and  one  fourth  is  the  usual  degree  of  attenuation.  Scotch  ale  soon  becomes  fine, 
and  IS  seldom  racked  for  the  home  market.  The  following  table  will  show  the  progress 
of  fermentation  in  a  brewing  of  good  Scotch  ale : 

20  barrels  of  mash-worts  of  42^  pounds  gravity  =  860-6 
20      —  returns  6JU  —  i22 


«iV 


12  )  982-6 


Fermentation : — 


pounds  weight  of  extract  per  quarter  of  rpalt  =  81 
March  24.  pitched  the  tun  at  51°:  yeast  4  gallons. 


AprD 


25. 
28. 
30. 

1. 

4. 

6. 

6. 

7. 

8. 

9. 
10. 


Temp. 

62° 
66° 
60° 
62» 
65» 
66* 
67* 
67* 
66° 
66° 
64° 


Gravity. 

41  pounds. 

39 

34 

32 

29  added  1  lb.  of  yeast 

25 

23 

20 

18 

15 

14-5  cleansed.  * 


The  following  table  shows  the  origin  and  the  result  of  fennentaiion,*in  a  number  of 
practical  experiments : — 


Oiigiaal  Gravity  of 
the  Worts. 


1-0950 

1-0918 
1-0829 
1-0862 
1-0780 
1-0700 
1-1002 


1  bB.  per  Barrel  of  Specific  Gravity  of 
Saccharine    Matter.  *^-  *'- 


88-75 

85-62 

78-125 

80-625 

73-75 

65-00 

93-75 


the  Ale. 


1-0500 
1-0420 
1-0205 
1-0236 
1-0280 
1-0285 
1-0400 


Lbs.  per  Barrel  of 
Saccharine    Matter. 


40-25 
38-42 
16-87 
20-00 
24-25 
25-00 
36-25 


Attenuation,  or  Sac- 
'harum  deconii>o8ed 


0-478 
0-552 
0-787 
0-757 
0-698 
0-615 
0-613 


*  Bbbwikq  (Society  for  diffusing  Useful  Knowledge),  p.  156. 


144 


J    1 
t    ) 


BEER. 
Fermenlation  T&Ue— continued. 


BEER. 


146 


Otiginal  Gravity  of 
the  Worts. 


lh».  per  Banel  of  (specific  Gmvity  of 
Sacchariue  Matter.  the  Ale. 


1-1025 

1-0978 
1-0956 
1-1130 
1-1092 
1-1171 
1-1030 
1-0660 


95-93 

91-56 

89-37 

105-82 

102-187 

110-00 

96-40 

61-25 


1-0420 

1-0307 

1-0358 

1-0352 

1-0302 

1-0400 

1-0271 

1-0214 


Lbs.  per  Barrel  of 
Saccharine    Matter, 


38-42 
27-00 
32-19 
31-87 
26-75 
36-25 
23-42 
17-80 


Attenuation,  or  S«c-1 
harum  decomposed.! 


neous,  on  account  of  the  quantity  of  ^^^^^i^^J^'^^PXn.i^^^^^^^    o  the  saccharine   matter 
tion.     It  must  be  likewise  ;^^°;:L^f^^^^*^^7JJe  a^^^^^^^^^  the  fermented  liquor, 

will  be  partly  counteracted,  by  the  eflect  of  the  f^^^i^^^^^^^^^^^^^  ^^rt ;  being  greatest 

less  to  be  used  with  Pjop^ety.  management  of  the  mashing,  may  be  tested 

The  good  quality  of  the  malt,  and  the  "f.^^^'^^X  succes  diawn  worts.     With 

by  the  Quantity  of  saccharme  matter  ^^J";,^;^^'?."^  ,^j^^^^^^^  ^y  a  safety-bath  heat 

this  view,  an  aliquot  portion  of  ^-*^^V thl„  m^^^^^^  tX  its  volume  of  sUong  spirit 

to  a  nearly  concrete  consistence,  ^^f^^^„^^""  ^^^^^  dLsoM^  the  starch  and  other 

of  wine.     The  truly  saccharme  ^^^^^.^^/^^f  J'^,^^^,^^  may  be  determined  by 

matters  will  be  separated;  jf  ^^^  ^^^^^,,i*^,^  Pl^nirmuch^^^^^^^  method  of 

filtration  and  evaporation      Or  an  ^^.^^^^J^^^^^^^^^^^^  with  the  alcohol 

arriving  at  the  same  result  ^^^^^  be,  after  agitating  ^/^^  vi  c  determine 

in  a  tali  glass  cylinder,  to  allow  the  'f,^'"^\J^^/^^\i°,^^^^^^^  additional  density 

the  specific  gravity  of  the  ^^P^J"'^^.^,^*.^  ?""^,\^„  quantTty  of  malt  sugar  which  it  ha. 
which  the  alcohol  has  acquired  ^'^l    fj^^^^  '^^  at  the  request  of  Henry  Warburton, 

received.    The  foll«w^»S;^^l^'JT'^"'*^^^^,^I,:Tte;  of  th\  of  Commons  in  1830, 

Esq.,  M.  P.,  chairman  of  the  M^las^es  Committee  ^^  ^/^^^^^  the  quantity  in 

wUl  Ihow  the  brewer  the  prmcip  e  ^^.  ^^^^..^P'l'.^^Vg^^^^^^  of  a  gallon  of  spirit  of  dif- 
grains  weight  of  sugar  requisite  to  raise  the  speciti.  gravity  oi      g  f 

ferent  densities  to  the  gravity  of  water  =  1-000  . 

iin^nifi.-  Gravity  of  Grains  ;  Weight  of  Sugar  in  the 

Specific  Uravity  oi  Gallon  Inipeiial. 

0-995  If 

0-990  ^  ^  " 

0-985  2-800 

0-980  3-710 

0-975  4-690 

0-970  ^'^^^ 

0-965  ^'^^^ 

0-960  "^'O^O 

S.955  f  00 

n.Qfio  9-310 

r  ♦!,•»  4oKi«  Txrne  to  «;how  the  effect  of  saccharine  matter  m 
The  immediate  P«n>ose  of  this  table  was  to  show  m^^^^^  of  the  distiller.    But 

disguising  the  presence  or  amount  of  alcohol  in    he  ^^^  taints  o  ^^  ^^^^_ 

a  similar  table  might  easily  be  ^^^^''^'^p^^^  would  be  shown  by 

h  )1  of  0-825,  for  example,  the  ^"^^J^^^^,  ^^  f^m  agitation  with  a  certain 

(he  increase  of  specific  gravity  ^'^^^J^  ^^^^^J^^^^^  consistence  by  a  safety-pan,  made  on 
weight  of  the  wort,  mspissated  to  a  nearly  solid  consisteny  j^^^   quantities 

theVinciple  of  my  Patent  susar.pan(Se^^^^^^^^^ 

being  lOOO.gram  ^^^^^^l^^J ^'"^f^^^^^^  ^^^^^^T 

rerTeL't!  of  t'^i^lyTa^c^^^^^^^^^  by  slbtra^ction,  that  of  farinaceous  matter 

present  in  it.  .  .  Brewerv. — Ftss.  113  and  114  represent  the 

Plan,Macl,l,.ery<.^U^^'^yfj^^^  the  largest  scale ,  m 

arrangement  of  the  "'^■'5"' """  "  .  ,^..,  {^^  elevation  fig.  113  is  in  a  great  degree  imp.- 

^  roX'piane"  u^n  ^Mch  U  L"    but  the  di^rent  vessels  .re  arranged  so  .. 


w  explain  their  uses  most  readily,  and  at  the  same  time  to  preserve,  as  nearly  as  poasibk. 
the  relative  positions  which  are  usually  assigned  to  each  in  works  of  this  nature. 


CO 


I 


mmms^^^^^^^^ 


cJfPllf  ?  V '  ^^  ®"PP^y  °^  ^^^  brewery  is  stored  in  vast  granaries  or  malt-lofts,  usuallf 
^n?v  1  »n  the  upper  part  of  the  buildings.  Of  these,  I  have  been  able  to  repre^ 
oniy  one,  at  a,  Jig,  113 :  the  others,  which  are  supposed  to  be  on  each  side  of  it,  cannot 


146 


BEER. 


BEER. 


ur 


II 


i 


l!fi 


be  seen  in  this  view.  Immediately  beneath  the  granary  A,  on  the  giound  floor,  is  the 
mill ;  in  the  upper  story  above  it,  are  two  pairs  of  rollers, ^g«.  Ill,  112,  and  113,  under 
a,  a,  for  bruising  or  crushing  the  grains  of  the  malt.  In  the  floor  beneath  the  rollers  are 
the  mill-stones  b,  &,  where  the  malt  is  sometimes  ground,  instead  of  being  mcxely  bruised 
by  passing  between  the  rollers,  under  a,  a. 

The  malt,  when  prepared,  is  conveyed  by  a  trough  into  a  chest  tf,  to  the  right  of  6, 
from  which  it  can  be  elevated  by  the  action  of  a  spiral  screw,  fig.  115,  enclosed  in  the 
sloping  lube  e,  into  the  large  chest  or  bin  b,  for  holding  ground  mall,  situated  imme- 
diately over  the  mash-tun  d.  The  malt  is  reserved  in  this  bin  till  wanted,  and  it  is 
then  let  down  into  the  mashing-tun,  where  the  extract  is  obtained  by  hot  water  supplied 
from  the  copper  g,  seen  to  the  right  of  b. 

The  water  for  the  service  of  the  brewery  is  obtained  from  the  well  e,  seen  beneath  the 
mill  to  the  left,  by  a  lifting  pump  worked  by  the  steam  engine ;  and  the  forcing-pipe  / 
of  this  pump  conveys  the  water  up  to  the  large  reservoir  or  water-back  f,  placed  at  the 
lop  of  the  engine-house.  From  this  cistern,  iron  pipes  are  laid  to  the  copper  g  (on  the 
right-hand  side  of  the  figure),  as  also  to  every  part  of  the  establishment  where  cold  water 
can  be  wanted  for  cleaning  and  washing  the  vessels.  The  copper  o  can  be  filled  with 
cold  water  by  merely  turning  a  cock ;  and  the  water,  when  boiled  therein,  is  conveyed 
by  the  pipe  g  into  the  bottom  of  the  mash-tun  d.  It  is  introduced  beneath  a  false  bot- 
tom, upon  which  the  malt  lies,  and,  rising  up  through  the  holes  in  the  false  bottom,  it 
extracts  the  saccharine  matter  from  the  malt ;  a  greater  or  less  time  being  allowed  for  the 
infusion,  according  to  circumstances.  The  instant  the  water  is  drawn  off  from  the  copper, 
fresh  water  must  be  let  into  it,  in  order  to  be  ready  for  boiling  the  second  mashing ;  be- 
cause the  copper  must  not  be  left  empty  for  a  moment,  otherwise  the  intense  heat  of  the 
fire  would  destroy  its  bottom.  For  the  convenience  of  thus  letting  down  at  once  as  much 
liquor  as  will  fill  the  lower  part  of  the  copper,  a  pan  or  second  boiler  is  placed  over  the 
top  of  the  copper,  as  seen  in  fig.  113;  and  the  steam  rising  from  the  eopper  communi- 
cates a  considerable  degree  of  heal  to  the  contents  of  the  pan,  without  any  expense  of 
fuel.     This  will  be  more  minutely  explained  hereafter.     (See  fig.  117.) 

During  the  process  of  mashing,  the  malt  is  agitated  in  the  mash-tun  so  as  to  expose 
every  part  to  the  action  of  the  water.  This  is  done  by  a  mechanism  contained  within 
the  mash-tun,  which  is  put  in  motion  by  a  horizontal  shaft  above  it,  h,  leading  from  the 
mill.  The  mash  machine  is  shown  separately  in  fig.  116.  When  the  operation  of  mash- 
ing is  finished,  the  wort  or  extract  is  drained  down  from  the  malt  into  the  vessel  i,  called 
the  undn-back,  immediately  below  the  mash-tun,  of  like  dimensions,  and  situated  always 
on  a  lower  level,  for  which  reason  it  has  received  this  name.  Here  the  wort  does  not  re- 
main longer  than  is  necessary  to  drain  off  the  whole  of  it  from  the  tun  above.  It  is  then 
pumped  up  by  the  three-barrelled  pump  fe,  into  the  pan  upon  the  top  of  the  copper,  by  a 
pipe  which  cannot  be  seen  in  this  section.  The  wort  remains  in  the  pan  until  the  water 
for  the  succeeding  mashes  is  discharged  from  the  copper.  But  this  delay  is  no  less  of 
time,  because  the  heat  of  the  copper,  and  the  steam  arising  from  it,  prepare  the  wort, 
which  had  become  cooler,  for  boiling.  The  instant  the  copper  is  emptied,  the  first  wort 
is  let  down  from  the  pan  into  the  copper,  and  the  second  wort  is  pumped  up  from  the 
under-back  into  the  upper  pan.  The  proper  proportion  of  hops  is  thrown  into  the  cop- 
per through  the  near  hole,  and  then  the  door  is  shut  down,  and  screwed  fast,  to  keep  in 
the  steam,  and  cause  it  to  rise  up  through  pipes  into  the  pan.  It  is  thus  forced  lo  blow 
up  through  the  wort  in  the  pan,  apd  communicates  so  much  heat  to  it,  or  water,  called  li- 
qiior  by  the  brewers,  that  either  is  brought  near  to  the  boiling  point.  The  different  worts 
succeed  each  other  through  all  the  different  vessels  with  the  greatest  regularity,  so  that 
there  is  no  loss  of  time,  but  every  part  of  the  apparatus  is  constantly  employed.  When 
the  ebullition  has  continued  a  sufficient  period  to  coagulate  the  grosser  part  of  the  extract, 
and  to  evaporate  part  of  the  water,  the  contents  of  the  copper  are  run  off  through  a  large 
cock  into  the  jack-back  k,  below  g,  which  is  a  vessel  of  sufficient  dimensions  to  contain 
it,  and  provided  with  a  bottom  of  cast-iron  plates,  perforated  with  small  holes,  through 
which  the  wort  drains  and  leaves  the  hops.  The  hot  wort  is  drawn  off  from  the  jack- 
back  through  the  pipe  h  by  the  three-barrelled  pump,  which  throws  ii  up  to  the  coolers 
L,  L,  L ;  this  pump  being  made  with  different  pipes  and  cocks  of  communication,  to  serve 
all  the  purposes  of  the  brewery  except  that  of  raising  the  cold  water  from  the  well.  The 
coolers  l,  l,  l,  are  very  shallow  vessels,  built  over  one  another  in  several  stages  :  and  that 
part  of  the  building  in  which  they  are  contained  is  built  with  lattice- work  or  shutter  flaps, 
on  all  sides,  to  admit  free  currents  of  air.  When  the  wort  is  sufficiently  cooled  to  be  put  to 
the  first  fermentation,  it  is  conducted  in  pipes  from  all  the  different  coolers  to  the  large 
fermenting  vessel  or  gyle-tun  m,  which,  with  another  similar  vessel  behind  it,  is  of  suffi- 
cient capacity  to  contain  £ill  the  beer  of  one  day's  brewings. 

Whenever  the  first  fermentation  is  concluded,  the  beer  is  drawn  off  from  the  great  fer- 
menting vessel  M,  into  the  small  fermenting  casks  or  cleansing  vessels  n,  of  which  there 
are  a  great  number  in  the  brewery.  They  are  placed  four  together,  and  to  each  four  a  com- 


1 


mon  spout  is  provided  to  carry  off  the  yeast,  and  conduct  it  into  the  troughs  tt,  placed 
beneath.  In  these  cleansing  vessels  the  beer  remains  till  the  fermentation  is  completed ; 
and  it  is  then  put  into  the  store-vats,  which  are  casks  or  tuns  of  an  immense  size,  where 

it    is    kept    till    wanted,  and    is 
finally    drawn    off   into    barrels, 
and  sent  away  from  the  brewery. 
The  store-vats  are  not  represented 
in  the  figure :  they  are  of  a  conical 
shape,    and    of  different    dimen- 
sions, from  fifteen   to  twenty  feet 
diameter,  and  usually  from  fifteen 
to   twenty  feet  in   depth.      The 
steam-engine  which  puts  all   the 
machine   in    motion    is    exhibited 
in   its  place,  on   the  left  side  of 
the   figure.     On  the   axis   of  the 
large  fly-wheel  is  a  bevelled  spur- 
wheel,   which    turns    another  si- 
milar wheel   upon   the   end   of  a 
horizontal    shaft,    which    extends 
from    the    engine-house    to    the 
great  horse-wheel,  set  in  motion 
by  means  of  a  spur-wheel.     The 
horse-wheel  drives  all  the  pinions 
for  the  mill-stones  6  6,  and   also 
the  horizontal  axis  which  works 
the  three-barrelled  pump  k.    The 
rollers  a,  a,  are  turned  by  a  bevel 
wheel  upon  the  upper  end  of  the 
axis  of  the  horse-wheel,  which  is 
prolonged  for  that   purpose;    and 
the   horizontal   shaft    h,   for    the 
mashing  engine,   is  driven   by  a 
pair  of  bevel   wheels.    There  is 
likewise   a  sack-tackle,   which  is 
not  represented.     It  is  a  machine 
for  drawing  up  the  sacks  of  malt 
from  the  court-yard  to  the  highest 
part  of  the  building,  whence  the 
sacks  are  wheeled  on    »  iruck  to 
the  malt-loft  a,  and  the   contents 
of  the  sacks  are  discharged. 

The  horse-wheel  is  intended  to 
be  driven  by  horses  occasionally, 
if  the  steam-engine  should  fail; 
but  these  engines  are  now  brought 
to  such  perfection  that  it  is  very 
seldom  any  recourse  of  this  kind  is 
needed. 

Fig.  114  is  a  representation 
of  the  fermeniing  house  at  the 
biewery  of  Messrs.  Whitbread 
and  Company,  Chiswell  Street, 
London,  which  is  one  of  the  most 
complete  in  its  arrangement  in 
the  world :  it  was  erected  after  the 
plan  of  Mr.  Richardson,  who  con- 
ducts the  brewing  at  those  works. 
The  whole  of  fig.  114  is  to  be 
considered  as  devoted  to  the  same 
object  as  the  large  vessel  m  and 
the  casks  n,  fig.  113.  In  fig.  114 
r  r  is  the  pipe  which  leads  from 
the  different  coolers  to  convey 
.  the  wort  to  the  great  fermenting 

tjessels  or  squares  m,  of  which  there  are  two,  one  behind  the  other ;  //  represents  a  part  of 
vne  great  pipe  which  conveys  all  the  water  from  the  weU  Eyfig.  113,  up  to  the  water  cistern 


'I 


!,!■    1 


:i! 


148 


BEER. 


p.  This  pipe  is  conducted  purposely  up  the  wall  of  the  fennenting-house,  ylg^.  114,  and 
has  a  cock  in  it,  near  r,  to  stop  the  passage.  Just  beneath  this  passage  a  branch-pipe  p 
proceeds,  and  enters  a  large  pipe  x  a-,  which  has  the  former  pipe  r  withinside  of  it. 
From  the  end  of  the  pipe  x,  nearest  to  the  squares  m,  another  branch  n  n  proceeds,  and 
returns  to  the  original  pipe/,  with  a  cock  to  regulate  it.  The  object  of  this  arrangement 
is  to  make  all,  or  any  part,  of  the  cold  water  flow  through  the  pipe  z  x,  which  surrounds 
the  pipe  r,  formed  only  of  thin  copper,  and  thus  cool  the  wort  passing  through  the  pipe 
r,  until  it  is  found  by  the  thermometer  to  have  the  exact  temperature  which  is  desirable 
before  it  is  put  to  ferment  in  the  great  square  m.  By  means  of  the  cocks  at  n  and  p,  the 
quantity  of  cold  water  passing  over  the  surface  of  the  pipe  r  can  be  regulated  at  pleasure, 
whereby  the  heat  of  the  wort,  when  it  enters  into  the  square,  may  be  adjusted  within  half 
a  degree. 

When  the  first  fermentation  in  the  squares  m  m  is  finished,  the  beer  is  drawn  off  from 
them  by  pipes  marked  v,  and  conducted  by  its  branches  w  w  w,  to  the  different  rows  of 
fermenting-tuns,  marked  n  n,  which  occupy  the  greater  part  of  the  building.  In  the 
hollow  between  every  two  rows  are  placed  large  troughs,  to  contain  the  yeast  which 
they  throw  off.  The  figure  shows  that  the  small  tuns  are  all  placed  on  a  lower  level 
than  the  bottom  of  the  great  vessels  m,  so  that  the  beer  will  flow  into  them,  and,  by  hy- 
drostatic equilibrium,  will  fill  them  to  the  same  level.  When  they  are  filled,  the  com- 
munication-cock is  shut ;  but,  as  the  working  off  the  yeast  diminishes  the  quantity  of 
beer  in  each  vessel,  it  is  necessary  to  replenish  them  from  time  to  time.  For  this 
purpose,  the  two  large  vats  o  o  are  filled  from  the  great  squares  m  m,  before  any  beer 
is  drawn  off  into  the  small  casks  n,  and  this  quantity  of  beer  is  reserved  at  the  highei 
level  for  filling  up.  The  two  vessels  o  o  are,  in  reality,  situated  between  the  two  squares 
M  M ;  but  I  have  been  obliged  to  place  them  thus  in  the  section,  in  order  that  they 
may  be  seen.  Near  each  filling-up  tun  o  is  a  small  cistern  t  communicating  with  the 
tun  o  by  a  pipe,  which  is  closed  by  a  float-valve.  The  small  cisterns  /  are  always  in 
communication  with  the  pipes  which  lead  to  the  small  fermenting  vessels  n  ;  and  there- 
fore the  surface  of  the  beer  in  all  the  tuns,  and  in  the  cisterns,  will  always  be  at  the  same 
level ;  and  as  this  level  subsides  by  the  working  off  of  the  yeast  from  the  tnns,  the  float 
sinks  and  opens  the  valve,  so  as  to  admit  a  sufliciency  of  beer  from  tlie  filling-up  tuns 
o,  to  restore  the  surfaces  of  the  beer  in  all  the  tuns,  and  also  in  the  cistern  /,  to  the 
original  level.  In  order  to  carry  off  the  yeast  which  is  produced  by  the  fermentation  of 
the  beer  in  the  tuns  o  o,  a  conical  iron  dish  or  funnel  is  made  to  float  upon  the  surface  of 
the  beer  which  they  contain ;  and  from  the  centre  of  this  funnel  a  pipe,  o,  descends,  and 
passes  through  the  bottom  of  the  tun,  being  packed  with  a  collar  of  leather,  so  as  to  be 
water-tight ;  at  the  same  time  that  it  is  at  liberty  to  slide  down,  as  the  surface  of  the  beer 
descends  in  the  tun.  The  yeast  flows  over  the  edge  of  this  funnel-shaped  dish,  and  is 
conveyed  down  the  pipe  to  a  trough  beneath. 

Beneath  the  fermenting-house  are  large  arched  vaults,  p,  built  with  stone,  and  lined 
with  stucco.  Into  these  the  beer  is  let  down  in  casks  when  suflUciently  fermented,  and 
is  kept  in  store  till  wanted.  These  vaults  are  used  at  Mr.  Whitbread's  brewery,  instead 
of  the  great  store-vats  of  which  we  have  before  spoken,  and  are  in  some  respects  pre- 
ferable, because  they  preserve  a  great  equality  of  temperature,  being  beneath  the  surface 
of  the  earth. 

The  malt-rollers,  or  machines  for  bruising  the  grains  of  the  malt,  figs.  Ill,  112,  have 
been  already  described.  The  malt  is  shot  down  from  a,  fig.  113,  the  malt-lofl,  into  the 
hopper ;  and  from  this  it  is  let  out  gradually  through  a  sluice  or  sliding  shuttle,  a,  fig.  113, 
and  falls  between  the  rollers. 

Fig.  115,  is  the  screw  by  which  the  ground  or  bruised  malt  is  raised  up,  or  conveyed 
from  one  part  of  the  brewery  to  another,  k  is  an  inclined  box  or  trough,  in  the  centre 
of  which  the  axis  of  the  screw  h  is  placed;  the  spiral  iron  plate  or  worm,  which  is 
fixed  projecting  from  the  axis,  ZitA  which  forms  the  screw,  is  made  very  nearly  to 
fill  the  inside  of  the  box.  By  this  means,  when  the  screw  is  turned  round  by  the 
wheels  e  f,  or  by  any  other  means,  it  raises  up  the  malt  from  the  box  d,  and  delivers  it 
at  the  spout  g. 

This  screw  is  equally  applicable  for  conveying  the  malt  horizontally  in  the  trough  k, 
as  slantingly  ;  and  similar  machines  are  employed  in  various  parts  of  breweries  for  con- 
veying the  malt  wherever  the  situation  of  the  works  requires. 

Fig.  116,  is  the  mashing-machine.  a  a  is  the  tun,  made  of  wood  staves,  hooped  to- 
gether. In  the  centre  of  it  rises  a  perpendicular  shail,  b,  which  is  turned  slowly  round 
by  means  of  the  bevelled  wheels  t  u  at  the  top.  c  c  are  two  arms,  projecting  from 
that  axis,  and  supporting  the  short  vertical  axis  d  of  the  spur-wheel  x,  which  is 
turned  by  the  spur-wheel  w;  so  that,  when  the  central  axis  b  is  made  to  revolve,  it 
will  carry  the  thick  short  axle  d  round  the  tun  in  a  circle.  That  axle  d  is  furnished 
with  a  number  of  arms,  e  e,  which  have  blades  placed  obliquely  to  the  plane  of  their 


BEER. 


149 


motion.    When  the  axis  is  turned  round,  these  arms  agitate  the  malt  in  the  tun,  and  give 
it  a  constant  tendency  to  rise  upward  from  the  bottom. 
The  motion  of  the  axle  d  is  produced  by  a  wheel,  x,  on  the  upper  end  of  it,  which  it 


^^^^fe^>>r^?:^^^;— -cT^ 


turned  by  a  wheel,  ir,  fastened  on  the  middle  of  the  tube  6,  which  turns  freely  round 
upon  its  central  axis.  Upon  a  higher  point  of  the  same  tube  6  is  a  bevel  wheel,  o, 
receivmg  motion  from  a  bevel  wheel,  q,  fixed  upon  the  end  of  the  horizontal  axis  n  «, 


which  gives  motion  to  the  whole  machine.  This  same  axis  has  a  pinion,  p,  upon 
n.  Which  gives  motion  to  the  wheel  r,  fixed  near  the  middle  of  a  horizontal  axle, 
wnicn,  at  its  left  hand  end,  has  a  bevel  pinion,  f,  working  the  wheel  u,  before  mentioned, 
uy  these  means,  the  rotation  of  the  central  axis  b  will  be  very  slow  compared  with  the 
motion  of  the  axled;  for  the  latter  will  make  seventeen  or  eighteen  revolutions  on  its 
own  a*'s  m  the  SMie  space  of  time  that  it  will  be  carried  once  round  the  tun  by  the 
motion  of  the  shaft  6.  At  the  beginning  of  the  operation  of  mashing,  the  machine  is 
made  to  turn  with  a  slow  motion;  but,  after  having  wetted  aU  the  malt  by  one  revo- 
muon.  It  is  driven  quicker.    For  this  purpose,  the  ascending  shaft  /  g,  which  gives 


I 


150 


BEER. 


motion  to  the  machine,  has  two  level  wheels,  h  t,  fixed  upon  a  tube,  /g,  which  is,  fitted 
upon  a  central  shaft.  These  wheels  actuate  the  wheels  m  and  o,  upon  the  end  of  the 
horizontal  shaft  n  n ;  but  the  distance  between  ihe  two  wheels  h  and  i  is  such,  that  they 
cannot  be  engaged  both  at  once  with  the  wheels  m  and  o ;  but  the  tube  /  g,  to  which 
they  are  fixed,  is  capable  of  sliding  up  and  down  on  its  central  axis  sufficiently  to  bring 
either  wheel  h  or  »  into  gear  with  its  corresponding  wheel  o  or  m,  upon  the  horizontal 
shaft ;  and  as  the  diameters  of  n  o,  and  i  rriy  are  of  very  different  proportions,  the  velocity 
of  the  motion  of  the  machine  can  be  varied  at  pleasure,  by  using  one  or  other,  k  and 
k  are  two  levers,  which  are  forked  at  their  extremities,  and  embrace  collars  at  the  ends 
of  the  \\xbcfg.  These  levers  being  united  by  a  rod,  I,  the  handle  k  gives  the  means  of 
moving  the  tube/g,  and  its  wheels  h  t,  up  or  down,  to  throw  either  the  one  or  the  other 
wheel  into  gear. 

The  object  of  boiling  the  wort  is  not  merely  evaporation  and  concentration,  but  extrac- 
tion, coagulation,  and,  finally,  combination  with  the  hops ;  purposes  which  are  better  ac- 
complished in  a  deep  confined  copper,  by  a  moderate  heat,  than  in  an  open  shallow  pan 
with  a  quick  fire.  The  copper,  being  incased  above  in  brickwork,  retains  its  digesting 
temperature  much  longer  than  the  pan  could  do.  The  waste  steam  of  the  close  kettle, 
moreover,  can  be  economically  employed  in  communicating  heat  to  water  or  weak  worts ; 
whereas  the  exhalations  from  an  open  pan  would  prove  a  nuisance,  and  would  need  to  be 
carried  off  by  a  hood.  The  boiling  has  a  four-fold  effect :  1.  it  concentrates  the  wort;  2. 
during  the  earlier  stages  of  heating,  it  converts  the  starch  into  sugar,  dextrine,  and  gum, 
by  means  of  the  diastase ;  3.  it  extracts  the  substance  of  the  hops  diffused  through  the 
wort ;  4.  it  coagulates  the  albuminous  matter  present  in  the  grain,  or  precipitates  it  by 
means  of  the  tannin  of  the  hops. 

The  degree  of  evaporation  is  regulated  by  the  nature  of  the  wort,  and  the  quality  of 
the  beer.  Strong  ale  and  stout  for  keeping,  require  more  boiling  than  ordinary  porter 
or  table-beer  brewed  for  immediate  use.  The  proportion  of  the  water  carried  off  by 
evaporation  is  usually  from  a  seventh  to  a  sixth  of  the  volume.  The  hops  are  introduced 
during  the  progress  of  the  ebullition.  They  serve  to  give  the  beer  not  only  a  bitter 
aromatic  taste,  but  also  a  keeping  quality,  or  they  counteract  its  natural  tendency  to 
become  sour ;  an  effect  partly  due  to  the  precipitation  of  the  albumen  and  starch,  by 
their  resinous  and  tanning  constituents,  and  partly  to  the  antifermentable  properties  of 
their  lupuline,  bitter  principle,  ethereous  oil,  and  resin.  In  these  respects,  there  is  none 
of  the  bitter  plants  which  can  be  substituted  for  hops  with  advantage.  For  strong  beer, 
powerful  fresh  hops  should  be  selected ;  for  weaker  beer,  an  older  and  weaker  article 
will  suffice. 

The  hops  are  either  boiled  with  the  whole  body  of  the  wort,  or  extracted  with  a 
portion  of  it ;  and  this  concentrated  extract  added  to  the  rest.  The  stronger  the  hops 
aie,  the  longer  time  they  require  for  extraction  of  their  virtues;  for  strong  hops,  an  hour 
and  a  half  or  two  hours  boiling  may  be  proper ;  for  a  weaker  sort,  half  an  hour  or  an 
hour  may  be  sufficient ;  but  it  is  never  advisable  to  push  this  process  too  far,  lest  a  dis- 
agreeable bitterness,  without  aroma,  be  imparted  to  the  beer.  In  our  breweries,  it  is  the 
practice  to  boil  the  hops  with  a  part  of  the  wort,  and  to  filter  the  decoction  through  a 
drainer,  called  the  jack  hop-back.  The  proportion  of  hops  to  malt  is  very  various ;  but,  in 
general,  from  a  pound  and  a  quarter  to  a  pound  and  a  half  of  the  former  are  taken  for 
100  lbs.  of  the  latter  in  making  good  table-beer.  For  porter  and  strong  ale,  2  pounds  of 
hops  are  used,  or  even  more ;  for  instance,  one  pound  of  hops  to  a  bushel  of  malt,  if  the 
beer  be  destined  for  the  consumption  of  India. 

During  the  boiling  of  the  two  ingredients,  much  coagulated  albuminous  matter,  in 
various  states  of  combination,  makes  its  appearance  in  the  liquid,  constituting  what  is 
called  the  breaking  or  curdling  of  the  worty  when  numerous  minute  flocks  are  seen  floating 
in  it.  The  resinous,  bitter,  and  oily-ethereous  principles  of  the  hops  combine  with  the 
sugar  and  gum,  or  dextrine  of  the  wort ;  but  for  this  effect  they  require  time  and  heat ; 
showing  that  the  boil  is  not  a  process  of  mere  evaporation,  but  one  of  chemical  reaction. 
A  yellowish-green  pellicle  of  hop-oil  and  resin  appears  upon  the  surface  of  the  boiling 
wort,  in  a  somewhat  frothy  form :  when  this  disappears,  the  boiling  is  presumed  to  be 
completed,  and  the  beer  is  strained  off  into  the  cooler.  The  residuarj'  hops  may  be 
pressed  and  used  for  an  inferior  quality  of  beei ;  or  they  may  be  boiled  with  fresh  wort, 
and  be  added  to  the  next  brewing  charge. 

Figs.  117,118,  represent  the  copper  of  a  London  brewery.  Fig.  117  is  a  vertical  section; 
fig.  118,  a  ground-plan  of  the  fire-grate  and  flue,  upon  a  smaller  scale  :  a  is  the  close  cop- 
per kettle,  having  its  bottom  convex  within ;  b  is  the  open  pan  placed  upon  its  top.  From 
the  upper  part  of  the  copper,  a  wide  tube,  c,  ascends,  to  carry  off  the  steam  generated 
during  the  ebullition  of  the  wort,  which  is  conducted  through  four  downwards-slanting 
tubes,  d  d  (two  only  are  visible  in  this  section),  into  the  liquor  of  the  pan  6,  in  order  to 
warm  its  contents.  A  vertical  iron  shaft  or  spindle,  e,  passes  down  through  the  tube  c. 
nearly  to  the  bottom  of  the  copper,  and  is  there  mounted  with  an  iron  arm,  called  a 


BEER. 


151 


rouser,  which  carries  round  a  chain  hung  in  loops,  to  prevent  the  hops  from  adhering  to 
the  bottom  of  the  boiler.  Three  bent  stays,/,  are  stretched  across  the  interior,  to  support 
the  shaft  by  a  collet  at  their  middle  junction.     The  shaft  carries  at  its  upper  end  a  bevel 


'''*^'>  Sy  working  into  a  bevel  pinion  upon  the  axis  A,  which  may  be  turned  either  by 
power  or  by  hand.  The  rouser  shaft  may  be  lifted  by  means  of  the  chain  t,  which,  going 
over  two  pulleys,  has  its  end  passed  round  the  wheel  and  axle  k,  and  is  turned  by  a 
winch  :  I  is  B.  tube  for  conveying  the  waste  steam  into  the  chimney  m. 

The  heat  is  applied  as  follows : — For  heating  the  colossal  coppers  of  the  London 
breweries,  two  separate  fires  are  required,  which  are  separated  by  a  narrow  wall  of 
brickwork,  n,Jigs.  117,  118.  The  dotted  circle  a' a' indicates  the  largest  circumference  of 
the  copper,  and  6'  b'  its  bottom ;  o  o  are  the  grates  upon  which  the  coals  are  thrown, 
not  throtigh  folding  doors  (as  of  old),  but  through  a  short  slanting  iron  hopper,  shown  at 
Pyjig.  117,  built  in  the  wall,  and  kept  constantly  filled  with  the  fuel,  in  order  to  exclude 
the  air.  Thus  the  lower  stratum  of  coals  gets  ignited  before  it  reaches  the  grate.  Above 
the  hopper  p,  a  narrow  channel  is  provided  for  the  admission  of  atmospherical  air,  ia 
such  quantity  merely  as  may  be  requisite  to  complete  the  combustion  of  the  smoke  of 
the  coals.  Behind  each  grate  there  is  a  fire-bridge,  r,  which  reflects  the  flame  upwards, 
and  causes  it  to  play  upon  the  bottom  of  the  copper.  The  burnt  air  then  passes  round 
the  copper  in  a  semicircular  flue,  s  s,  from  which  it  flows  off  into  the  chimney  »w,  on 
whose  under  end  a  slidine  damper-plate,  /,  is  placed  for  tempering  the  draught.  When 
wld  air  is  admitted  at  this  orifice,  the  combustion  of  the  fuel  is  immediately  checked. 
There  is,  besides,  another  slide-plate  at  the  entrance  of  the  slanting  flue  into  the  vertical 
chimney,  for  regulating  the  play  of  the  flame  under  and  around  the  copper.  If  the  plate 
the  opened,  and  the  other  plate  shut,  the  power  of  the  fire  is  suspended,  as  it  ought  to 
be,  at  the  time  of  emptying  the  copper.  Immediately  over  the  grate  is  a  brick  arch,  w,  to 
protect  the  front  edge  of  the  copper  from  the  first  impulsion  of  the  flame.  The  chim- 
**?  i^  ^"PPOJ'ted  upon  iron  pillars,  r,  r ;  ly  is  a  cavity  closed  with  a  slide-plate,  through 
which  the  ashes  may  be  taken  out  from  behind,  by  means  of  a  long  iron  hook. 

Fig.  119  represents  one  of  the  sluice-cocks,  which  are  used  to  make  the  commu- 
nications of  the  pipes  with  the  pumps,  or  other  parts  of  the  brewery,  b  b  represenU 
the  pipe  m  which  the  cock  is  placed.  The  two  parts  of  this  pipe  are  screwed  to  the 
side  of  a  box,  c  c,  in  which  a  slider,  a,  rises  and  faUs,  and  intercepts,  at  pleasure,  the 
passage  of  the  pipe.    The  slider  is  moved  by  the  rod  a.    This  passes  through  a  stuffing- 


it 


f 


t. '' 


li 


152 


BEER. 


box,  in  the  top  of  the  box  which  contains  the  slider,  and  has  the  rack  b  fastened  to  it 
The  rack  is  moved  by  a  pinion  fixed  upon  the  axis  of  a  handle  e,  and  the  rack  and 
pinion  are  contained  in  a  frame  d  which  is  supported  by  two  pillars.  The  frame 
contains  a  small  roller  behind  the  rack,  which  bears  it  up  towards  the  pinion,  and  keeps 
its  teeth  up  to  the  teeth  of  the  pinion.  The  slider  a  is  made  to  fit  accurately  against 
the  internal  surface  of  the  box  c,  and  to  bear  against  this  surface  by  the  pressure  of 
a  spring,  so  as  to  make  a  perfectly  close  fitting. 

Fig.  120  is  a  small  cock  to  be  placed  in  the  side  of  the  great  store  vats,  for  the 
purpose  of  drawing  off  a  small  quantity  of  beer  to  taste  and  try  its  quality,     a  is  a 


part  of  the  stave  or  thickness  of  tne  great  store  vat;  into  this  the  tube  b  of  the  cock 
js  fitted,  and  is  held  tight  in  its  place  by  a  nut,  a,  a,  screwed  on  withinside.  At  the 
other  end  of  the  tube  b,  a  plug,  c,  is  fitted,  by  grinding  it  into  a  cone,  and  it  is  kept 
m  by  a  screw.  This  plug  has  a  hole  up  the  centre  of  it,  and  from  this  a  hole  pro- 
.•eeds  side-wise,  and  corresponds  with  a  hole  made  through  the  side  of  the  tube  when 
the  cock  is  open;  but  when  the  plug  c  is  turned  round,  the  hole  will  not  coincide  and 
then  the  cock  will  be  shut,  d  is  the  handle  or  key  of  the  cock,  by  which  its  plug  is 
turned  to  open  or  shut  it :  this  handle  is  put  up  the  bore  of  the  tube  (the  cover  k 
being  first  unscrewed  and  removed),  and  the  end  of  it  is  adapted  to  fit  the  end  of  the 
plug  of  the  cock.  The  handle  has  a  tube  or  passage  bored  up  it,  to  convey  the  beer 
away  from  the  cock  when  it  is  opened,  and  from  this  the  passage/,  through  the  han- 
dle, leads,  to  draw  the  beer  into  a  glass  or  tumbler.  The  hole  in  the  side  of  the  plug 
IS  so  arranged,  that,  when  the  handle  is  turned  into  a  perpendicular  direction  with 
the  passage/  downwards,  the  cock  will  be  open.  The  intention  of  this  contrivance  is 
that  there  shall  be  no  considerable  projection  beyond  the  surface  of  the  tun;  because 
It  sometimes  happens  that  a  great  hoop  of  tlie  tun  breaks,  and,  falling  down,  its  great 
weight  would  strike  out  any  cock  which  had  a  projection ;  and,  if  this  happened  in 
the  night,  much  beer  might  be  lost  before  it  was  discovered.  The  cock  above  de- 
scribed, being  almost  wholly  withinside,  and  having  scarcely  any  projection  beyond 
the  outside  surface  of  the  tun,  is  secure  from  this  accident 

Fig.  121  is  a  small  contrivance  of  a  vent  peg,  to  be  screwed  into  the  head  of  a  common 
cask  when  the  beer  is  to  be  drawn  off  from  it,  and  it  is  necessary  to  admit  some  air  to 
^        121       allow  the  beer  to  flow,    a  a  represents  a  portion  of  the  head 
of  the  cask  into  which  the  tube  b  is  screwed.     The  top  of 
C  this  tube  is  surrounded  by  a  small  cup,  from  which  project 
the  two  small  handles  c  c,  by  which  the  peg  is  turned  round 
to  screw  it  into  the  cask.     The  cup  round  the  other  part  of 
the  tube  is  filled  with  water ;  into  this  a  small  cup,  d,  is  in- 
verted; in  consequence,  the  air  can  gain  admission  into  the 
^^^  V  1-1-1  ^*^^  -when  the  pressure  within  is  so  far  diminished,  that  the 

air  will  bubbk  up  through  the  watei-,  and  enter  beneath  the  small  cup  d. 

The  most  efficient  substance  for  fining  beer  hitherto  discovered  is  isinglass,  which  is 
prepared  by  solution  in  vinegar  or  old  stale  beer,  and  this  solution  is  afterwards  reduced 
with  thm  mild  beer  generally  brewed  for  the  purpose,  in  all  large  establishments,  from 
a  raw  or  return  wort  It  must  next  be  passed  through  a  fine  hair  sieve,  by  means  ol 
rubbing  it  down  with  a  hard  hair-brush,  and  brought  to  the  proper  consistency  by  tliin 
mild  beer.  If  properly  made,  it  will  be  clear,  transparent  and  free  from  feculencies. 
Finings  serve  excellently  to  remove  any  extraneous  matter  that  may  be  found  floating 
in  the  beer,  and  thus  changes  it  from  bright  to  brilliant"  The  common  quantity  used 
is  from  a  pint  to  a  quart  per  barrel,  according  to  the  nature  of  the  beer. 

To  ascertain  whether  the  beer  is  in  a  fit  state  for  fining,  put  it  into  a  long  glaaj 
cylindric  vessel,  and  add  to  it  a  teaspoonful,  or  thereby,  of  the  fining ;  then  give  the 
mixture  a  good  shake,  by  turning  the  vessel  up  and  down,  after  closing  its  mouth  with 


\ 


BEER. 


158 


the  palm  of  the  hand.  If  the  beer  has  been  well  brewed,  its  aptitude  to  become  bright 
will  be  soon  shown  by  the  mixture  getting  thick  and  curdy ;  a  bright  portion  will  gener- 
ally show  itself  at  the  bottom  or  middle ;  after  which  the  finings  will  gradually  mount  to 
the  top,  takina:  up  all  the  impurities  along  with  them,  till  the  whole  becomes  brilliant 
Some  have  said  that  the  finings  should  carry  the  impurities  down  to  the  bottom ;  but 
this,  according  to  Mr.  Black,*  takes  place  only  with  stubborn  beer,  which  would  not  be- 
come thoroughly  bright  with  any  quantity  of  finings  which  could  be  introduced.  Finings 
have  usually  a  specific  gravity  of  from  I'OIO  to  1-016,  and,  when  added  to  beer  in  a  fit 
condition  for  fining,  invariably  go  to  the  top,  and  not  to  the  bottom.  In  fining  beer  in 
a  barrel  laid  on  its  side,  if  the  finings  do  not  make  their  appearance  at  the  bung-hole, 
the  beer  will  not  become  bright.  The  isinglass  must  not  be  dissolved  with  heat,  nor  in 
hot  water. 

Beer  brewed  from  imperfectly  malted  grain,  or  from  a  mixture  of  malt  and  raw  com, 
gives  a  fermentation  quite  different  in  flavor  from  that  of  beer  from  sound  malt.  The 
nose  is,  in  fact,  the  best  guide  to  the  experienced  brewer  for  ascertaining  whether  his 
process  is  going  on  well  or  ill. 

Ropiness  is  a  morbid  state  of  beer,  which  is  best  remedied,  according  to  Mr.  Black,  by 
putting  the  beer  into  a  vat  with  a  false  bottom,  and  adding,  per  barrel,  4  or  5  pounds  of 
hops,  taken  gradually  away  after  the  first  boilings  of  the  worts ;  and  to  them  may  be 
added  about  half  a  pound  per  barrel  of  mustard-seed.  Rouse  the  beer  as  the  hops  are 
gradually  introduced,  and,  in  some  months,  the  ropiness  will  be  perfectly  cured.  The 
beer  should  be  drawn  off  from  below  the  false  bottom. 

For  theoretical  views,  see  Fermentation  ;  and  for  wort-cooling  apparatus,  see  Refbi- 
gerator. 

The  quantity  of  beer  and  ale  exported  from  the  United  Kingdom  amoimted  in  1850 
to  182,480  barrels,  and  in  1851  to  191,639;  the  declared  value  being  respectively 
558,794/.,  and  577,874/. 

Beer  (Bavarian).  The  Germans  from  time  immemorial  have  been  habitually  beer 
drinkers,  and  have  exercised  much  of  their  technical  and  scientific  skill  in  the  produc- 
tion of  beer  of  many  different  kinds,  some  of  which  are  little  known  to  our  nation, 
while  one  at  least,  called  Bavarian,  possesses  excellent  qualities,  entitling  it  to  the  at- 
tention of  all  brewers  and  consumers  of  this  beverage.  The  peculiarities  in  the  manu- 
facture of  Bavai-ian  beer  have  recently  attracted  the  attention  of  the  most  eminent 
chemists  in  Germany,  especially  of  Professor  Liebig,  and  much  new  light  has  thereby 
been  thrown  upon  this  curious  portion  of  vegetable  chemistry,  which  I  shall  endeav- 
or to  reflect  upon  the  present  article. 

The  following  is  a  list  of  the  principal  beers  at  present  brewed  in  Germany. 

I.  Brown  beer  of  Merseburg ;  of  pure  barley  malt. 

—  —  barley  malt  and  beet-root  sugar. 

—  barley  malt,  potatoes,  and  beet- root  syrup. 

—  refined  beet-root  syrup  alone. 
Co  vent  or  thin  beer. 
Berlin  white  beer,  or  the  Champagne  of  the  north. 

7.  Bro3'han,  a  famous  Hanoverian  beer. 

8.  Double  beer  of  Grunthal. 

9.  Bavarian  beer ;  1.  Summer  beer;  2.  "Winter  beer. 

10.  —  Bock-beer. 

II.  Wheat  Xa^'^r-beer  (slowly  fermented). 
12.  White  bitter  beer  of  Erlangen. 

Considerable  interest  among  men  of  science,  in  favor  of  the  Bavarian  beer  proijess, 
has  been  excited  ever  since  the  appearance  of  Liebig's  Organic  Chemistry,  first  pub^ 
lished  about  twelve  years  ago.  In  the  introduction  to  this  admirable  work,  he  says, 
"The  beers  of  England  and  France,  and  the  most  parts  of  those  of  Germany,  become 
gradually  sour  by  contact  of  air.  This  defect  does  not  belong  to  the  beers  of  Bavaria, 
which  may  be  preserved  at  pleasure  in  half-full  casks,  as  well  as  full  ones,  without  al- 
teration in  the  air.  This  precious  quality  must  be  ascribed  to  a  peculiar  process 
emploj'ed  for  fermenting  the  wort,  called  in  German  untcrgahrung,  or  fermentation 
from  below ;  which  has  solved  one  of  the  finest  theoretical  problems. 

•'  Wort  is  proportionally  richer  in  soluble  gluten  than  in  sugar,  f  When  it  is  set  to 
ferment  by  the  ordinary  process,  it  evolves  a  large  quantity  of  yeast  in  tbe  state  of  a 
thick  froth,  with  bubbles  of  carbonic  acid  gas  attached  to  it,  whereby  it  is  floated  to  the 
surface  of  the  liquid.  This  phenomenon  is  easily  explained.  In  the  body  of  the  wort 
along  side  of  particles  of  sugar  decomposing,  there  are  particles  of  gluten  being  oxidized 

*  Treatise  on  Brewing,  8vo.  p.  68. 

t  It  does  not  surely  contain   more  gluten  than  it  does  sugar:  at  least  no  experiments,  known  to  mo. 
prove  this  proposition.  ^ 


2. 
3. 
4. 
5. 
6. 


H 


ji  t 

'i 


154 


BEER.  BAVARIAN. 


at  the  same  time,  and  enveloping  as  it  were  the  former  particles,  whence  the  carbonic 
acid  of  the  sugar  and  the  insoluble  ferment  from  the  gluten  being  simultaneoush  pro- 
duced, should  mutually  adhere.  When  the  metamorphosis  of  the  sugar  is  completed 
there  remains  still  a  large  quantity  of  gluten  dissolved  in  the  fermented  liquor,  which 
gluten,  in  virtue  of  its  tendency  to  appropriate  oxygen,  and  to  get  decomposed, 'induces 
also  the  transformation  of  the  alcohol  into  acetic  acid  (vinegar).  But  were  all  the 
matters  susceptible  of  oxidizement  as  well  as  this  vinegar  ferment  removed,  the  beer 
would  thereby  lose  its  faculty  of  becoming  sour.  These  conditions  are  duly  fulfilled  in 
the  process  followed  in  Bavaria. 

"  In  that  country  the  malt-wort  is  set  to  ferment  in  open  backs,  with  an  extensive  sur- 
face, and  placed  in  cool  cellars,  having  an  atmospheric  temperature  not  exceedinp  8°  or 
lOP  centigrade  (46|°  or  50°  F.).  The  operation  lasts  from  3  to  4  weeks;  the  carbonic 
acid  is  disengaged,  not  in  large  bubbles  that  burst  on  the  surface  of  the  liquid,  but  in 
very  small  vesicles,  like  those  of  a  mineral  water,  or  of  a  liquor  saturated  with  carbonic 
acid,  when  the  pressure  is  removed.  The  surface  of  the  fermenting  wort  is  always  in 
contact  with  the  oxygen  of  the  atmosphere,  as  it  is  hardly  covered  with  froth,  and  as 
all  the  yeast  is  deposited  at  the  bottom  of  the  back  under  the  form  of  a  very  viscid 
sediment,  called  in  German  unterhefe. 

**  In  order  to  form  an  exact  idea  of  the  difference  between  the  two  processes  of  fer- 
mentation. It  must  be  borne  in  mind  that  the  metamorphosis  of  gluten  and  of  azotized 
bodies  m  general  is  accomplished  successively  in  two  principal  periods,  and  that  it  is  in 
the  first  that  the  gluten  is  transformed  in  the  interior  of  the  liquid  into  an  insoluble 
ftrment,  and  that  it  separates  alongside  of  the  carbonic  acid  proceeding  from  the  sugar. 
This  separation  is  the  consequence  of  an  absorption  of  oxygen.  It  is,  however,  hardly 
possible  to  decide  if  this  oxygen  comes  from  the  sugar,  from  the  water,  or  even  from 
an  intestine  change  of  the  gluten  itself,  or,  in  other  words,  whether  the  oxygen  com- 
bines directly  with  the  gluten,to  give  it  a  higher  degree  of  oxidation,  or  whether  it  lays 
hold  of  its  hydrogen  to  form  water. 

"This  oxidation  of  the  gluten,  from  whichever  cause,  and  the  transformation  of  the 
sugar  into  carbonic  acid  and  alcohol,  are  two  actions  so  correlated,  that  by  an  exclusion 
of  the  one,  the  other  is  immediately  stopped." 

The  superficial  ferment  {oberhefe  in  German)  which  covers  the  surface  of  the  fer- 
menting works  is  gluten  oxidized  in  a  state  of  putrefaction ;  and  the  ferment  of  d«)o«7« 
IS  the  gluten  oxidized  in  a  state  of  eremacausie. 

The  surface  yeast,  or  barm,  excites  in  liquids  containing  sugar  and  gluten  the  same 
alteration  which  itself  is  undergoing,  whereby  the  sugar  and  the  gluten  suffer  a  rapid 
and  tumultuous  metamorphosis.  We  may  form  an  exact  idea  of  the  different  states  of 
these  two  kinds  of  yeast  by  comparing  the  superficial  to  vegetable  matters  putrefying 
at  the  bottom  of  a  marsh,  and  the  bottom  yeast  to  the  rotting  of  wood  in  a  state  of 
eremacausie,  that  is,  of  slow  combustion.  The  peculiar  condition  of  the  elements  of  the 
sediment  ferment  causes  them  to  act  upon  the  elements  of  the  sugar  in  an  extremely 
slow  manner,  and  excites  the  change  into  alcohol  and  carbonic  acid,  without  that  of  the 
dissolved  gluten. 

Sugar,  which  at  ordinary  temperatures  has  no  tendency  to  combine  with  oxygen, 
enters  in  the  above  predicament  into  fermentation ;  but  the  action  is  rendered  much 
slower  by  the  low  temperature,  while  the  affinity  of  the  dissolved  gluten  for  the  oxygen 
of  the  air  is  aided  by  the  contact  of  the  sediment.  The  superficial  yeast  may  be 
removed  without  stopping  the  fermentation,  but  the  under  yeast  can  not  be  removed 
without  arresting  all  the  phenomena  of  disoxidation  of  the  second  period.  These  would 
immediately  cease  ;  and  if  the  temperature  were  now  raised,  they  would  be  succeeded 
by  the  phenomena  of  the  first  period.  The  deposite  does  not  excite  the  phenomena  of 
tumultuous  fermentation,  for  which  reason  it  is  totally  unfit  for  panification  (bread- 
baking),  while  the  superficial  yeast  alone  is  suitable  to  this  purpose. 

If  to  wort  at  a  temperature  of  from  46^°  to  50°  F.  the  top  yeast  be  added,  a  quiet 
slow  fermentation  is  produced,  but  one  accompanied  with  a  rising:  up  of  the  mass,  while 
yeast  collects  both  at  the  surface  and  bottom  of  the  backs.  If  this  deposite  be  removed 
to  make  use  of  it  in  other  operations,  it  requires  by  little  and  little  the  characters  of  the 
unterhe/e,  and  becomes  incapable  of  exciting  the  phenomena  of  the  first  fermenting 
period,  causing  only,  of  59°  F.,  those  of  the  second;  namely,  sedimentary  fermentation. 
It  must  be  carefully  observed  that  the  right  unterhefe  is  not  the  precipitate  which  falls 
to  the  bottom  of  backs  in  the  ordinary  fermentation  of  beer,  but  is  a  matter  entirely 
different.  Peculiar  pains  must  be  taken  to  get  it  genuine,  and  in  a  proper  condition  at 
the  commencement.  Hence  the  brewers  of  Hessia  and  Prussia,  who  wished  to  make 
Bavarian  beer,  found  it  more  to  their  interest  to  send  for  the  article  to  Wurtzburg,  or 
Bamberg,  in  Bavaria,  than  to  prepare  it  themselves.  When  once  the  due  primary  fer- 
mentation has  been  established  and  well  regulated  in  a  brewery,  abundance  of  the  true 
unterhefe  may  be  obtained  for  all  future  operations. 


BEER,  BAVARIAN. 


155 


In  a  wort  made  to  ferment  at  a  low  temperature  with  deposite  only,  the  presence  of 
the  unterhefe  is  the  first  condition  essential  to  the  metamorphosis  of  the  saccharum, 
but  it  is  not  competent  to  bring  about  the  oxidation  of  the  gluten  dissolved  in  the  wort, 
and  its  transformation  into  an  insoluble  state.  This  change  must  be  accomplished  at 
the  cost  of  the  atmospherical  oxygen.  ,  .      ^     /•  r*u 

In  the  tendency  of  soluble  gluten  to  absorb  oxygen,  and  in  the  free  access  of  the 
air,  all  the  conditions  necessary  for  its  eremacausis,  or  slow  combustion,  are  to  be  found 
It  is  known  that  the  presence  of  oxygen  and  soluble  gluten  are  also  the  conditions  of 
acetification  (vinegar-making),  but  ihey  are  not  the  only  ones ;  for  this  process  requires 
a  temperature  of  a  certain  elevation  for  the  alcohol  to  experience  this  slow  combustion. 
Hence,  by  excluding  that  temperature,  the  combustion  (oxidation)  of  alcohol  is  ob- 
structed, while  the  gluten  alone  combines  with  the  oxygen  of  the  air.  This  property- 
does  not  belong  to  alcohol  at  a  low  temperature,  so  that  during  the  oxidation  in  this 
case  of  the  gluten,  the  alcohol  exists  alongside  of  it,  in  the  same  condition  as  the  gluten 
alongside  of  sulphurous  acid  in  the  muted  wines.  In  wines  not  impregnated  with  the 
fumes  of  burning  sulphur,  the  oxygen  which  would  have  combined  at  the  same  time 
with  the  gluten  and  the  alcohol  does  not  seize  either  of  them  in  wines  which  have  been 
subjected  to  mutism,  but  it  unites  itself  to  the  sulphurous  acid  to  convert  it  into  the 
sulphuric.  The  action  called  sedimentary  fermentation  is  therefore  merely  a  simulta- 
neous metamorphosis  of  putrefaction  and  slow  combustion ;  the  sugar  and  the  unterhefe 
putrefy,  and  the  soluble  gluten  gets  oxidized,  not  at  the  expense  of  the  oxygen  of  the 
water  and  the  sugar,  but  of  the  oxygen  of  the  air,  and  the  gluten  then  falls  in  the  in- 
soluble state.  The  process  of  Appert  for  the  preservation  of  provisions  is  founded 
upon  the  same  principle  as  the  Bavarian  process  of  fermentation  i  in  which  all  the  pu- 
trescible  matters  are  separated  by  the  intervention  of  the  air  at  a  temperature  too  low 
for  the  alcohol  to  become  oxidized.  By  removing  them  in  this  way,  the  tendency  of 
the  beer  to  grow  sour,  or  to  suffer  a  further  change,  is  prevented.  Appert's  method 
consists  in  placing  in  presence  of  vegetables  or  meat  which  we  wish  to  preserve  the 
oxygen  at  a  high  temperature,  so  as  to  produce  slow  combustion,  but  without  putre- 
faction or  even  fermentation.  By  removing  the  residuary  oxygen  after  the  combustion 
is  finished,  all  the  causes  of  an  ulterior  change  are  removed.  In  the  sedimentary  fer- 
mentation of  beer,  we  remove  the  matter  which  experiences  the  combustion ;  whereas, 
on  the  contrary,  in  the  method  of  Appert,  we  remove  that  which  produces  it. 

It  is  uncertain  whether  the  dissolved  gluten,  in  being  converted  into  insoluble  yeast 
by  the  action  of  the  oxygen,  combines  directly  with  the  oxygen ;  that  is  to  say,  whether 
the  yeast  differs  from  the  soluble  gluten  merely  by  having  absorbed  an  additional  quan- 
tity of  oxygen.  This  question  is  in  fact  very  difficult  to  solve  by  analysis.  If  the  gluten 
be  regarded  as  a  hydrogenated  combination,  it  is  obvious  that  in  the  fermentation  of 
wine-must,  and  malt-wort,  the  hydrogen  will  be  carried  off  by  the  oxygen,  and  the 
action  will  then  be  the  same  as  the  transformation  of  alcohol  into  aldehyde.  When  the 
contact  of  the  atmosphere  is  excluded,  this  oxygen  can  not  evidently  be  derived  from  the 
elements  of  the  air,  or  from  those  of  the  water ;  for  it  can  not  be  supposed  that  oxygen 
will  take  hydrogen  from  the  water,  in  order  to  recompose  water  with  the  hydrogen  of 
the  gluten.  The  elements  of  the  saccharum  must  therefore  furnish  this  oxygen ;  or  in 
the  course  of  the  formation  of  the  yeast,  a  portion  of  the  sugar  will  be  decomposed  ;  but 
thts  decomposition  is  not  of  the  same  kind  as  that  which  results  from  the  immediate 
metamorphosis  of  the  sugar  into  carbonic  acid  and  alcohol ;  hence  a  certain  portion  of 
the  sugar  will  afford  neither  alcohol  nor  carbonic  acid,  but  it  will  yield  less  oxgenated 
products  from  its  elements.  These  products  occasion  the  great  difference  in  the  qual- 
ities of  fermented  liquors,  and  particularly  in  their  alcoholic  strength.  In  the  ordinary 
fermentation  of  grape-juice  and  worts,  these  liquids  do  not  furnish  a  quantity  of  alcohol 
equivalent  to  the  sugar  which  they  contain,  because  a  certain  portion  of  the  sugar  serves 
for  the  oxidation  of  the  gluten,  and  is  not  transformed  like  the  rest.  But  whenever  the 
liquor  has  arrived  at  the  second  period,  the  product  in  alcohol  ought  to  be  equivalent  to 
the  quantity  of  sugar  present,  as  happens  in  all  fermentations  which  are  not  accom- 
panied with  a  formation,  but  a  disappearance  of  the  yeast.  It  is  well  ascertained  that 
worts  furnish  in  the  Bavarian  breweries  10  or  20  per  cent,  more  alcohol  than  they  do 
by  the  ordinary  process  of  fermentation.  It  is  also  a  well-established  fact  that  in  the 
manufacture  of  spirits  from  potatoes,  where  no  yeast  is  produced,  or  merely  a  quantity 
corresponding  to  the  proportion  of  barley-malt  added  to  the  potato- wort,  a  quantity  of 
alcohol  may  be  produced,  as  also  of  carbonic  acid,  corresponding  exactly  to  the  quan. 
tity  of  carbon  in  the  fecula  employed.  But,  on  the  contrary,  in  the  fermentation  of 
beet-root  juice,  it  is  hardly  possible  to  determine  precisely,  from  the  quantity  of  car- 
bonic acid  evolved,  the  quantity  of  sugar  contained  in  the  beets,  for  there  is  always 
less  carbonic  acid  than  the  juice  of  the  fresh  root  would  furnish.  In  equal  volumes, 
the  beer  made  by  the  unterhefe  process  contains  more  alcohol,  and  is  therefore  more 
heady  than  that  formed  by  the  ordinary  process. 


156 


BEER,  BAVARIAN 


BEER,  BAVARIAN. 


157 


!i 


fl 


K- 


fi  K 


i 


The  temp(^rature  at  which  fermentation  is  carried  on  has  a  very  marked  influence 
upon  the  quantity  of  alcohol  produced.  It  is  known  that  the  juice  of  beets  set  to 
ferment  between  86°  and  95  Fahr.  does  not  yield  alcohol,  and  its  sugar  is  replaced  by 
a  less  oxygenated  substance,  mannite,  and  lactic  acid,  resulting  from  the  mucilage. 
In  proportion  as  the  temperature  is  lowered  the  mannite  fermentation  diminishes. 
As  to  azotized  juices,  however,  it  is  hardly  possible  to  define  the  conditions  undef 
which  the  transformation  of  the  sugar  will  take  place,  without  being  accompanied  with 
another  decomposition  which  modifies  its  products.  The  fermentation  of  beer  by 
deposite  demonstrates  that  by  the  simultaneous  action  of  the  oxygen  of  the  air  and  a 
low  temperature,  the  metamorphosis  of  sugar  is  effected  in  a  complete  manner ;  for 
the  vessels  in  which  the  operation  is  carried  on  are  so  disposed  that  the  oxygen  of  the 
air  may  act  upon  a  surface  great  enough  to  transform  all  the  gluten  into  insoluble 
yeast,  and  thus  to  present  to  the  sugar  a  matter  constantly  undergoing  decomposition. 
The  oxidizement  of  the  dissolved  gluten  goes  on,  but  that  of  the  alcohol  requires  a 
higher  temperature ;  whence  it  can  not  sufl'er  eremacausis,  that  is,  acetification,  or 
conversion  into  vinegar. 

At  the  beginning  of  the  fermentation  of  must  and  wort,  the  quantity  of  matter 
undergoing  change  is  obviously  the  largest.  All  the  phenomena  which  accompany  it, 
the  disengagement  of  gas  and  the  rise  of  temperature,  are  most  active  at  this  period, 
and  in  proportion  as  the  decomposition  advances,  the  external  signs  of  it  become  less 
perceptible,  without,  however,  disappearing  completely  before  the  transformation  has 
reached  its  limit.  The  slow  and  continuous  decomposition  which  succeeds  to  the 
rapid  and  violent  disengagement  of  gases  is  denominated  the  after  or  complementary 
fermentation.  For  wine  and  beer  it  lasts  till  all  the  sugar  has  disappeared,  so  that  the 
specific  gravity  of  the  liquors  progressively  diminishes  during  several  months.  This 
slow  fermentation  is  in  most  cases  a  truly  depositary  fermentation ;  for  by  the  pro- 
gressive decomposition  of  the  less,  the  sugar  still  in  solution  gets  completely  trans* 
formed ;  but  when  the  air  is  excluded,  that  decomposition  does  not  occasion  the  com- 
plete separation  of  the  azotized  matters  in  an  insoluble  shape. 

In  several  states  of  the  German  confederation,  the  favorable  influence  of  a  rational 
process  of  fermentation  upon  the  quality  of  the  beers  has  been  fully  recognised.  In 
the  Grand  Dutchy  of  Hesse  considerable  premiums  were  proposed  for  the  brewing  of 
beer  according  to  the  process  pursued  in  Bavaria,  which  were  decreed  to  those  brewers 
who  were  able  to  prove  that  their* product  (neither  strong  nor  highly  hopped)  had  kept 
six  months  in  the  casks  without  becoming  at  all  sour.  When  the  first  trials  were  being 
made  several  thousand  barrels  were  spoiled,  till  eventually  experience  led  to  the  dis- 
covery of  the  true  practical  conditions  which  theory  had  foreseen  and  prescribed. 

Neither  the  richness  in  alcohol,  nor  in  hops,  nor  both  combined,  can  hinder  ordinary 
beer  from  getting  tart.  In  England,  says  Liebig,  an  immense  capital  is  sacrificed 
to  preserve  the  better  sorts  of  ale  and  porter  from  souring,  by  leaving  them  for  several 
years  in  enormous  tuns  quite  full,  and  very  well  closed,  while  their  tops  are  covered 
with  sand.  This  treatment  is  identical  with  that  applied  to  wines  to  make  them 
deposite  the  wine-stone.  A  slight  transpiration  of  air  goes  on  in  this  case  through 
the  pores  of  the  wood ;  but  the  quantity  of  azotized  matter  contained  in  the  beer  is  so 
great,  relatively  to  the  proportion  of  oxygen  admitted,  that  this  element  can  not  act 
upon  the  alcohol.  And  yet  the  beer  thus  managed  will  not  keep  sweet  more  than 
two  months  in  smaller  casks  to  which  air  has  access.  The  grand  secret  of  the  Munich 
brewers  is  to  conduct  the  fermentation  of  the  wort  at  too  low  a  temperature  to  permit 
of  the  acetification  of  the  alcohol,  and  to  cause  all  the  azotized  matters  to  be  com- 
pletely separated  by  the  intervention  of  the  oxygen  of  the  air,  and  not  by  the  sacrifice 
of  the  sugar.  It  is  only  in  March  and  October  that  the  good  store  beer  is  begun  to  be 
made  in  Bavaria. 

In  our  ordinary  breweries,  the  copious  disengagement  of  carbonic  acid  from  the 
frothy  top  of  the  fermenting  tuns  and  gjies  prevents  the  contact  of  oxygen  from  the 
worts ;  so  that,  as  the  gluten  can  not  be  oxidized  by  the  air,  it  attracts  oxygen  from 
the  sugar,  and  thus  gives  rise  to  several  adventitious  hydrogenated  products,  just  as 
the  fetid  oil  is  generated  in  the  rapid  fermentation  of  spirit-wash  by  the  distillers.  In 
this  case  no  inconsiderable  portion  of  the  gluten  remains  undecomposed  in  the  beer, 
which,  by  its  extreme  proneness  to  corruption,  afterward  attracts  oxygen  greedily  from 
the  air,  and,  at  temperature  above  52^,  imparts  this  contact  action  to  the  alcohol,  and,  by 
a  species  of  infection,  changes  it  into  vinegar.  Indeed,  in  most  of  the  rapid  fermenta- 
tions a  portion  of  vinegar  is  formed,  which  itself  serves  as  an  acetous  ferment  to  the  rest 
of  the  alcohol ;  whereas  the  result  of  the  bottom  fermentation  is  a  beer  free  from  vinegar, 
and  certainly  hardly  a  trace  of  gluten ;  so  that  it  does  not  possess  the  conditions  requisite 
to  intestine  change  or  deterioration.  This  perfection  is,  however,  in  my  opinion,  rarely 
attained.  In  my  several  journeys  into  Germany  I  have  met  with  much  spurious  or 
ill-made  Bavarian  beer.    The  best  contains,  when  brought  to  England,  a  little  acid. 


but  no  perceptible  gluten  on  the  addition  of  ammonia  in  excess, 
ales,  &c.,  deposits  more  or  less  gluten  when  thus  treated. 


Most  of  our  beers. 


The  following  table  exhibits  the  results  of  the  chemical  examinations  of  the  under- 
mentioned kinds  of  beer : — 


Name  of  the  Beer. 


Augustine  double  beer — 
Munich 

Sal  vator  beer  —  do.    - 

Bock-beer,  from  the  Royal 
brewery  —  do. 

Schenk  (pot)  beer,  from  a  Ba- 
varian country  brewery ;  a 
kind  of  small  beer 

Bock-beer  of  Brunswick,  of 
the  Bavarian  kind 

Lager  (store)  beer,  of  Bruns- 
wick, of  the  Bavarian  kind 

Brunswick  sweet  small  beer 

Brunswick  mum 


i 


Quantity  in  100  parts  by  weight 

Water. 

Malt  extr. 

Alcohol. 

Carb.  acid. 

Analyst.  : 

88-86 

8-0 

3-6 

0-14 

Kaiser. 

87-62 

8-0 

4-2 

0-18 

Do. 

88-64 

7-2 

4-0 

0-16 

Do. 

92-94 

4-0 

2-9 

0-16 

Do. 

88-50 

6.50 

5-0 

- 

Balhorn. 

91-0 

5-4 

3-50 

w                             V 

Otto. 

84-70 
59-2 

14-0 
39-0 

1-30 
1.80 

0-1 

Do. 
Kaiser. 

Malting  in  Munich. — The  barley  is  steeped  till  the  acrospire,  embryo,  or  seed-germ, 
seems  to  be  quickened ;  a  circumstance  denoted  by  a  swelling  at  the  end  of  that  ear 
which  was  attached  to  the  foot-stalk,  as  also  when,  on  pressing  a  pile  between  two 
fingers  against  the  thumb-nail,  a  slight  projection  of  the  embryo  is  perceptible.  As 
long,  however,  as  the  seed-germ  sticks  too  firm  to  the  husk,  it  has  not  been  steeped 
enough  for  exposure  on  the  underground  malt-floor.  Nor  can  deficient  steeping  be 
safely  made  up  for  afterward  by  sprinkling  the  malt-couch  with  a  watering-can,  which 
is  apt  to  render  the  malting  irregular.  The  steep-water  should  be  changed  repeatedly, 
according  to  the  degree  of  foulness  and  hardness  of  the  barley ;  first,  six  hours  after 
immersion,  having  previously  stirred  the  whole  mass  several  times;  afterward,  in 
winter,  every  twenty-four  hours,  but  in  summer  every  twelve  hours.  It  loses  none  of 
its  substance  in  this  way,  whatever  vulgar  prejudice  may  think  to  the  contrary.  After 
letting  off  the  last  water  from  the  stone  cistern,  the  Bavarians  leave  the  barley  to  drain 
in  it  during  four  or  six  hours.  It  is  now  taken  out,  and  laid  on  the  couch  floor,  in  a 
square  heap,  eight  or  ten  inches  high,  and  it  is  turned  over,  morning  and  evening,  with 
dexterity,  so  as  to  throw  the  middle  portion  upon  the  top  and  bottom  of  the  new-made 
couch.  When  the  acrospire  has  become  as  long  as  the  grain  itself,  the  malt  is  carried 
to  the  withering  (welkboden)  or  drying-floor,  in  the  open  air,  where  it  is  exposed  (in 
dry  weather)  during  from  eight  to  fourteen  days,  being  daily  turned  over  three  times 
with  a  winnowing  shovel.  It  is  next  dried  on  a  well-constructed  cylinder  or  flue- 
heated  malt-kin,  at  a  gentle  clear  heat,  without  being  browned  in  the  slightest  degree, 
while  it  turns  triable  into  a  fine  white  meal.  Smoked  malt  is  entirely  rejected  by  the 
best  Bavarian  brewers.  Their  malt  is  dried  on  a  series  of  wove  wire  horizontal  shelves, 
placed  over  each  other ;  up  through  whose  interstices  or  perforations  streams  of  air, 
heated  to  only  122^  Fahr.,  rise  from  the  surfaces  of  rows  of  hot  sheet-iron  pipe-flues, 
arranged  a  little  way  below  the  shelves.  Into  these  pipes  the  smoke  and  burned  air 
of  a  little  furnace  on  the  ground  are  admitted.  The  whole  is  enclosed  in  a  vaulted 
chamber,  from  whose  top  a  large  wooden  pipe  issues,  for  conveying  away  the  steam 
from  the  drying  malt.  Each  charge  of  malt  may  be  completely  dried  on  this  kiln  in  the 
space  of  from  eighteen  to  twenty-four  hours,  by  a  gentle  uniform  heat,  which  does  not 
injure  the  diastase,  or  discolor  the  farina.* 

The  malt  for  store-beer  should  be  kept  three  months  at  least  before  using  it,  and  be 
freed  by  rubbmg  and  siitmg  from  the  acrospires  before  being  sent  to  the  mill,  where 
it  should  be  crushed  pretty  fine.  The  barley  employed  is  the  liest  distichon  or  common 
kind,  styled  hordeum  vulgare. 

The  hops  are  of  the  best  and  freshest  growth  of  Bavaria,  called  the  fine  spatter,  or 
aaatser  Bohemian  townhops,  and  are  twice  as  dear  as  the  best  ordinary  hops  of  the  rest 
of  Germany.    They  are  in  such  esteem  as  to  be  exported  even  into  France. 

The  Bavarians  are  so  much  attached  to  the  beer  beverage,  which  they  have  enjoyed 
from  their  reototest  ancestry,  that  they  regard  the  use  of  distilled  spirits,  even  in 
moderation,  as  so  immoral  a  practice,  as  to  disqualify  dram-drinkers  for  decent  society. 

*  I  have  a  set  or  designs  of  the  Bavarian  kiln,  but  I  l)elieve  the  al>ove  description  will  make  its  con- 
stroction  sufficiently  intelligible. 


158 


BEER,  BAVARIAN. 


BEER,  BAVARIAN. 


' 


- 


Their  government  has  taken  great  pains  to  improve  this  national  beverage,  by  en- 
couraging the  growth  of  the  best  qualities  of  hops  and  barley.  The  vaults  in  which 
the  beer  is  fermented,  ripened,  and  kept,  are  aH  underground,  and  mostly  in  stony  ex- 
cavations, called  felsenkeller  or  rock-cellars.  The  beer  is  divided  into  two  sorts,  called 
summer  and  winter.  The  latter  is  light,  and,  being  intended  for  immediate  retail  in 
tankards,  is  termed  schankbier.  The  other,  or  the  lagerbier,  very  sensibly  increases  in 
vinous  strength  in  proportion  as  it  decreases  in  sweetness,  by  the  judicious  manage- 
ment of  the  nachgdhrung,  or  fermentation  in  the  casks.  In  several  parts  of  Germany 
a  keeping  quality  is  communicated  to  beers  by  burning  sulphur  in  the  casks  before 
fillin^  them,  or  by  the  introduction  of  sulphite  of  lime.  But  the  flavor  thus  im- 
parted is  disliked  in  Munich,  Bayreuth,  Regensburg,  Niimberg,  Hof,  and  the  other 
chief  towns  of  Bavaria ;  instead  of  which  a  preservative  virtue  is  sought  for  in  an 
aromatic  mineral  or  Tyrol  pitch,  with  which  the  insides  of  the  casks  are  carefully  coated, 
and  in  which  the  ripe  beer  is  kept  and  exported.  In  December  and  January,  after  the 
casks  are  charged  with  the  summer  or  store-beer,  the  double  doors  of  the  cellars  are 
closed,  and  lumps  of  ice  are  piled  up  against  them,  to  prevent  all  access  of  warm  air. 
The  cellar  is  not  opened  till  next  August,  in  order  to  take  out  the  beer  for  consump- 
tion. In  these  circumstances  the  beer  becomes  transparent  like  champagne  wine ; 
and,  since  but  little  carbonic  acid  gas  has  been  disengaged,  little  or  none  of  the  addi- 
tionally generated  alcohol  is  lost  by  evaporation. 

The  winter  or  schank  (pot)  beer  is  brewed  in  the  months  of  October,  November, 
March,  and  April;  but  the  summer  or  store-beer  in  December,  January,  and  Feb- 
ruary, or  the  period  of  the  coldest  weather.  For  the  former  beer,  the  hopped  worts 
are  cooled  down  only  to  from  51°  to  55°,  but  for  the  latter  to  from  41°  to  42|°  Fahr. 
The  winter  beer  is  also  a  little  weaker  than  the  summer  beer,  being  intended  to  be 
sooner  consumed ;  since  four  bushels*  (Berlin  measure)  of  fine,  dry,  sifted  malt,  of 
large  heavy  hordeum  vulgare  distichon,  affords  seven  eimers  of  winter  beer,  but  not  more 
than  from  five  and  a  half  to  six  of  summer  beer.f  At  the  second  infusion  of  the  worts, 
small  beer  is  obtained  to  the  amount  of  twenty  quarts  from  the  above  quantity  of  malt. 
For  the  above  quantity  of  winter  beer,  six  pounds  of  middling  hops  are  reckoned 
sufficient ;  but  for  the  summer  beer,  from  seven  to  eight  pounds  of  the  finest  hops. 
The  winter  beer  may  be  sent  out  to  the  publicans  in  barrels  five  days  after  the  fer- 
mentation has  been  completed  in  the  tuns,  and,  though  not  quite  clear,  it  will  become 
so  in  the  course  of  six  days ;  yet  they  generally  do  not  serve  it  out  in  pots  for  two  or 
three  weeks.  But  the  summer  beer  must  be  perfectly  bright  and  still  before  it  is 
racked  off  into  casks  for  sale. 

Statement  of  the  Products  of  a  Brewing  of  Bavarian  Beer. — The  quantity  brewed  is 
41  Munich  eimers  (64  maass)  =85|  Berlin  quarts;  and  60  Berlin  quarts  =  1  eimer; 
or  24  Munich  barrels  (of  100  Berlin  quarts  each) ;  1  Munich  eimer  =15  gallons 
imperial.    The  beer  contains  from  50  to  60  parts  by  weight,  of  dry  saccharum  in  1,000 

parts. 

Expenditure,  Thaler.  Slbg, 

24  Berlin  bushels  of  white  kiln-dried  barley,  rather  finely  crushed, 

weighing  from  12  to  13  cwts.  _  _  .  - 

36  pounds  of  new  fine  spatter  (parted)  hops  at  46  thalers  the  cwt. 
I  pound  of  Carageen  moss,  for  clarifying  -  -  - 

1  quart  of  yeast. 
1  quart  of  Tyrol  pitch     ------ 

Mash — tax   (in  Bavaria  and  Prussia)  upon  12  cwts.  malt,  at  the 

rate  of  20  siWergroschen  =  2s.,  the  cwt.      -  -  - 

Cost  of  crushing  .-----. 

Fuel        -------- 

Wages  of  labor,  in  the  brewhouse  and  vault      .  -  - 

Do.        Do.     for  cooper  in  pitching  the  casks 
Sundry  small  expenses    .----- 


159 


24 

0 

16 

17 

0 

3 

11 

0 

8 

0 

1 

0 

4 

0 

6 

0 

3 

0 

2 

10 

Or  IIZ.  Ss. 

1  thaler  =  30  silbergroschen  =  3  shillings 

Deduct  for  the  grains  of  12  cwts.  of  malt,  at  10  silbergroschen,  or  Is. 
per  cwt.  =  4  thalers,  and  for  the  value  in  yeast  produced  =  2 
thalers  more    ------- 

Total  neat  expenditure  =  lOZ.  10*.        -  -  .  - 


76 


-    70      0 


•  An  English  quarter  of  grain  is  equal  to  5  bushels  (scheffeJ)  and  nearly  one  third  Prussian  measure. 
1 1  EiTr)er  Prussian  =15   English  imperial  gallons  ;  one  Munich  scAejfe/ is  equal  to  four  Berlin  fcAejfelf; 
1  Lib.  Munich  =  1-235  Eng.  lbs.  Avoird. :  I  Lib.  Berlin  =  1031  lbs.  Avoird. 


24 

0 

20 

0 

0 

3 

11 

0 

8 

0 

1 

0 

4 

0 

12  27 

81 

0 

6 

0 

75 

0 

This  cost  for  42  eimers  (1  eimer  =  14£  galls.  Imp.)  =  619|  gallons  =  17'2  London 
porter  barrels,  amounts  to  4^d.  per  gallon,  or  12*.  2d.  per  barrel.     By  the  above 
reckoning,  a  good  profit  accrues  to  the  brewer,  after  allowing  a  liberal  sum  for  the 
rent  of  premises,  interest  of  capital,  &c. 

He  has  less  profit  from  the  summer  beer.     For  a  brewing  of  33  eimers  =  505  gallons 
Imp.,  containing  from  60  to  65  pounds  of  saccharum  in  1,000  pounds  of  the  beer,  by 
Hermstaedt's  saccharometer. 

Expenditure. 

Thaler.  Slbg. 
24  Berlin  scheffels  of  white  kiln-dried  barley-malt,  weighing  from 

12  to  13  centners*  ----.-, 

48  Berlin  pounds  of  fresh  Bavarian  fine  hops,  at  46  thaler  per  centner 
J  pound  of  Carageen  moss  -  -  -  -  . 

1  quart  setting  yeast  (unterhefe). 

1  centner  pitch  ------. 

Malt  tax  on  12  centners  ----.. 

Crushing  the  malt  -----. 

Fuel  -  --.-.. 

Wages,  6  thalers ;  coopers'  do.,  3  thalers ;  and  sundries,  3  th.  27  sq. 

Deduct  for  grains  4  thalers,  and  yeast  2  thalers 

Neat  cost  -------. 

This  cost  of  IIZ.  5s.  for  505  gallons  amounts  to  fully  5|<f.  per  gallon,  and  16*.  6d. 
the  barrel. 

The  cost  at  Munich  is  2|  thalers  the  eimer,  and  4  thalers  the  barrel.  The  eimer  of 
the  summer  beer,  or  lagerbier,  is  sold  for  4  thalers.  The  publicans  there,  as  in  Lon- 
don, are  known  to  add  more  or  less  water  to  their  beer  before  retailing  it. 

The  yeast  (unterhefe)  is  carefully  freed  by  a  scraper  from  the  portion's  of  li^ht  top 
yeast  that  may  have  fallen  to  the  bottom;  the  true  unterhefe  is  then  carefully  sliced  off 
from  the  slimy  sediment  on  the  wood. 

In  Munich  the  malt  is  moistened  slightly  12  or  16  hours  before  crushin*'  it  with  from 
2  to  3maasf  of  water  for  every  bushel;  the  malt  being  well  dried,  and  several  months 
old.  The  mash-tun  into  which  the  malt  is  immediately  conveyed  is,  in  middle-sized 
breweries,  a  round  oaken  tub,  about  4|  feet  deep,  10  feet  in  diameter  at  bottom  and 
y  at  top,  outside  measure,  containing  about  6,000  Berlin  quarts.  Into  this  tun  cold 
water  is  admitted  late  in  the  evening,  to  the  amount  of  25  quarts  for  each  scheffeL  or 
600  quarts  for  the  2i  scheffels  of  the  ground  malt,  which  are  then  shot  in  and  stii^ed 
about  and  worked  well  about  with  the  oars  and  rakes,  till  a  uniform  pasty  is  formed 
without  lumps.  It  IS  left  thus  for  three  or  four  houss ;  3,000  quarts  of  water  beino' 
put  into  the  copper,  and  made  to  boil;  and  1,800  quarts  are  gradually  run  down  intS 
the  mash-tun,  and  worked  about  m  it,  producing:  a  mean  temperature  of  142-5°  Fahr 
After  an  hour's  interval,  during  which  the  copper  has  been  kept  full,  1,800  additional 
quarts  of  water  are  run  mto  the  tun,  with  suitable  mashing.  The  copper  bein?  now 
emptied  of  water  the  mash-mixture  from  the  tun  is  transferred  into  it,  and  brou-ht 
quickly  to  the  boilmg  point,  with  careful  stirring  to  prevent  its  setting  on  the  bottom 
and  getting  burned,  and  it  is  kept  at  that  temperature  for  half  an  hour.    When  the  mash 

Ji!^?n^^hn  tf  •"i^"''l'  'V'T'^'-  T  r^'J^  '*^'^"--  '^^''  P^«^^««  »s  <^«"ed,  in  Bavaria, 
boiling  the  thick  mash,  dickmatsch  kochen.     The  mash  is  next  returned  to  the  tun  and 

well  worked  about  in  it.  A  few  barrels  of  a  thin  mash-wort  are  kept  ready  to  be  put 
mto  the  copper  the  moment  it  is  emptied  of  the  thick  mash.  After  a  Quarter  of  an 
hour's  repose  the  portion  of  liquid  filtered  through  the  sieve-part  of  the  bottom  of  the 
un  mto  the  wort-cistern  is  put  into  the  copper,  thrown  back  boiling  hot  into  the  mash 
m  the  tun,  which  is  once  more  worked  thoroughly. 

The  copper  is  next  cleared  out,  filled  up  with  water,  which  is  made  to  boil  for  the 
d/awn°offTlear      '  ^'^™°-     ^^^^'  ^^«  ^^^^^  settling  in  the  open  tun,  the  worts  aie 

ihl'^^Z  ^^^  """PP^"'  f^^^  JP-,*""/  ^"""^  ^'-^  ^^*^  ^^^  ^o''*'  the  hops  are  introduced,  and 
hc^.  Tl?rl\  Tfif  '"^  ^f  •  ^""""^  ^  ^^^"^^^  ^^  ^^  ^«"^-  This  is  called  roasting  the 
dZina  ufllJ       if^^  '^^''^  '^^"""^  ^""l  *"*^  ^^^  <^«PPe^'  ^"d  boiled  along  with  the  hops 

?he  L%  ^ter  ntn  thT  ""V""  ^T  ''^'^  t  ^^^^'  "^^^  °^^^^^^  ^«  ^^^"  ^^^^^  out  through 
lvnit.5  ^  *^  coohng-cistern,  where  it  stands  three  or  four  inches  deep,  and  is 

exposed  upon  an  extensive  surface  to  natural  or  artificial  currents  of  cold  air,  so  as  to 

*  1  Centner  =  110  Prussian  pounds  =  113-44  lbs.  Avoird. 
T  A  Bavarian  moo*  =  IJ  quarts  English  measure. 


ICO  BEER,  BAVARIAN. 

be  quickly  cooled.  Foi  every  20  barrels  of  lagerbier,  there  are  allowed  10  of  small 
beer ;  so  that  30  barrels  of  wort  are  made  in  all.  v     ♦  kqo  t.  v     :„  fu^ 

For  the  winter  or  pot-beer  the  worts  are  brought  down  to  abou  59^  Fahr  i„  the 
cooler,  and  the  beer  is  to  be  transferred  into  the  ferment mg-tuns  at  from  54-5  to  59° 
Fahr.  for  the  summer  or  lagerbier,  the  worts  must  he  brought  down  in  the  cooler  to 
from  43°  to  45^,  and  put  into  the  fermentmg-tuns  at  to  from  41   to  43    Fahr^ 

A  few  hours  beforehand,  while  the  wort  is  still  at  the  temperature  of  63^  Fahr  a 
quantity  oUobb  must  be  made,  called  vorstellen  (forcsetting)  m  German,  by  mLVoig  the 
proportion  of  unterhefe  (yeast)  intended  for  the  whole  brewing  with  a  baxrel  or  a 
barrel  and  a  half  of  the  worts,  in  a  smaU  tub  called  the  gaAr-^ten.  slimng  them  well 
toeether  so  that  they  may  immediately  run  into  fermentation.  This  ld>b  is  in  this 
stfte  to  be  added  to  the  worts.  The  lobb  is  known  to  be  ready  when  it  is  covered  with 
a  white  froth  from  one  quarter  to  one  half  an  inch  thick:  during  which  it  must  be  well 
covered  up.  The  large  fermenting-tun  must  in  like  manner  be  kept  covered,  even 
in  the  vault.    The  colder  the  worts,  the  more  yeast  must  be  used.    For  the  above 

quantity,  at  _  ^  ^     ^    v  x- 

Tiom  bT  to  59°  Fahi.,  6  inaas  of  unterhefe. 

53°  to  55°  8  — 

48°  to  50°  10  — 

41°  to  33°  12  — 

Some  recommend  that  wort  for  this  kind  of  fermentation  (the  untergahrung)  should  be 
get  with  the  yeast  at  from  48°  to  57° ;  but  the  general  pracUce  at  Munich  is  to  set  the 
summer  irtgcr  beer  at  from  41°  to  43°  F.  ,      ,j   •    ♦!,  ~,„  ^r 

Bv  following  the  preceding  directions,  the  wort  m  the  tun  should,  m  the  course  of 
from  twelve  to  twenty-four  hours,  exhibit  a  white  froth  round  the  rim,  and  even  a  sbght 
whiteness  in  the  middle.     After  another  twelve  or  twenty-four  hours,  the  froth  should 
appear  in  curls ;  and,  in  a  third  like  period,  these  curls  should  be  changed  into  a  still 
higher  frothy  brownish  mass.    In  from  twenty-four  to  forty-eight  hours  more,  the  barm 
should  have  fallen  down  in  portions  through  the  beer,  so  as  to  allow  it  to  be  seen  m  cer- 
tain  points.     In  this  case  it  may  be  turned  over  into  the  smaller  ripening  tuns  m  the 
course  of  other  five  or  six  days.     But  when  the  worts  have  been  set  to  ferment  at  from 
41°  to  43°  Fahr.,  they  require  from  eight  to  nine  days.     The  beer  is  transferred,  aHer 
being  freed  from  the  top  yeast  by  a  skimmer,  by  means  of  the  stopcock  near  the  bottom 
of  the  large  tun.     It  is  either  first  run  into  an  intermediate  vessel,  m  order  that  the  top 
and  bottom  portions  may  be  well  mixed,  or  into  each  of  the  lager  casks,  in  a  numbered 
series,  like  quantities  of  the  top  and  bottom  portions  are  introduced.     In  the  ripening 
cellars  the  temperature  can  not  be  too  low.     The  best  keeping  beer  can   never  be 
brewed  unless  the  temperature  of  the  worts  at  settmg,  and  of  course  the  fermenting- 
vault,  be  as  low  as  50°  F.     In  Bavaria,  where  this  manufacture  is  carried  on  under 
government  inspectors,  a  brewing  period  is  prescribed  by  law,  which  is,  for  the  under 
fermenting  la^er  beer,  from  Michaelmas  (29th  September)  to  St.  George  (23d  AprJ). 
From  the  latter  to  the  former  period  the  ordinary  top-barm  beer  alone  is  to  be  made. 
The  ripening-casks  must  not  be  quite  full,  and  they  are  to  be  closed  merely  with  a 
loose  bung,  in  order  to  allow  of  the  working  over  of  the  ferment,  ^^^^^^^^^^f .^^e  /jj- 
mentation  appear  too  languid,  after  six  or  eight  days,  a  little  briskly  fermenting  lager 
beer  may  be  introduced.    The  store  lager  beer-tuns  are  not  to  be  quite  filled,  so  as  to 
prevent  all  the  yeasty  particles  from  being  discharged  in  the  ripening  fermentation; 
but  the  pot  la-er  beer-tuns  must  be  made  quite  full,  as  this  beverage  is  mtended  for 

speedy  sale  within  a  few  weeks  of  its  being  made. i,     „„ j  „wv 

As  soon  as  the  summer  beer-vaults  are  charged  with  their  ripening-casks,  and  with 
Ice-cold  air,  they  are  closed  air-tight  with  triple  doors,  having  small  intervals  between, 
so  that  one  may  be  entered  and  shut  again,  before  the  next  is  opened.  These  vaults 
are  sometimes  made  in  ran-es  radiating  from  a  centre,  and  at  others  m  rooms  set  ofl 
at  right  andes  to  a  main  gallery  ;  so  that  in  either  case,  when  the  external  opening  is 
well  secured,  with  triple  air-tight  doors,  it  may  be  entered  at  any  time,  in  order  to 
inspect  the  interior,  without  the  admission  of  warm  air  to  the  beer-barrels.  The 
wooden  bungs  for  loosely  stopping  them  must  be  coated  with  the  proper  pitch,  to 
prevent  the  possibility  of  their  imparting  any  acetous  ferment.  In  the  Beer  Brewer 
of  A.  F.  Zimmermann,  teacher  of  theoretical  and  practical  brewing,  who  has  devoted 
thirty.fi ve  years  to  this  business,  it  is  stated,  that  a  ripened  tun  of  lager  or  store-beer 
must  be  racked  off  all  at  once,  for  when  it  is  left  half  full  it  becomes  flat  (schaal) ;  and 
that  the  tun  of  pot  lager  beer  must,  if  possible,  be  all  drunk  off  in  the  same  day  it  is 
tapped:  because  on  the  following  day  the  beer  gets  an  unpleasant  taste,  even  when 
the  bukg  has  not  been  taken  out,  but  only  a  small  hole  has  been  made,  which  is 
opened  only  at  the  time  of  drawing  the  beer,  and  is  immediately  closed  again  with  a 

♦  Der  Bicr.Braucr,  als  Meister  in  seinem  fache,  Ac,  iUustrates  with  many  plates,  BerUn.  184a. 


BEER,  BAVARIAN. 


161 


spigot.  He  ascribes  this  change  to  the  loss  of  the  carbonic  acid  gas,  with  which  Uie 
beer  has  got  strongly  impregnated  during  the  latter  period  of  its  ripening,  while 
being  kept  in  tightly-bunged  casks.  The  residuums  in  these  casks  are,  however, 
bottled  up  in  Bavaria,  whereby  the  beer,  after  some  time,  recovers  its  brisk  and 
pungent  taste.  But  the  beer-topers  in  Bavaria,  who  are  professedly  very  numerous, 
indulge  so  delicate  and  fastidious  a  palate,  that  when  assembled  m  their  lavorite  pot- 
house, they  wait  impatiently  for  the  tapping  of  a  fresh  cask,  and  cease  for  a  whUe  to 
tipple  whenever  it  is  half  empty,  puffing  the  time  away  with  their  pipes  till  another 
fresh  tap  be  made.  In  the  well-frequented  beer-shops  of  Munich  a  common-sized  cask 
oilagzr  boer  is  thus  drank  ofi'in  an  hour.  A  reputation  for  superior  brewing  is  there 
the  readiest  road  to  fortune. 

Bock'Beer  of  Bavaria.— This  is  a  favorite  double  strong  beverage,  of  the  best  lager 
description,  which  is  so  named  from  causing  its  consumers  to  prance  and  tumble  about 
like  a  buck  or  a  goat;  for  the  German  word  bock  has  both  these  meanings.  It  ia 
merely  a  beer  having  a  specific  gravity  one  third  greater,  and  is  therefore  made  with 
a  third  greater  proportion  of  malt,  but  with  the  same  proportion  of  hops,  and  flavored 
with  a  few  coriander-seeds.  It  has  a  somewhat  darker  color  than  the  general  lager 
beer,  occasionally  brownish,  taste  less  bitter  on  account  of  the  predominating  malt, 
and  somewhat  aromatic.  It  is  an  eminently  intoxicating  beverage.  It  is  brewed  in 
December  and  January,  and  takes  a  long  time  to  ferment  and  ripen ;  but  still  it  con- 
tains too  large  a  quantity  of  unchanged  saccharum  and  dextrine  for  its  hops,  so  that  it 
tastes  too  luscious  for  habitual  topers,  and  is  drunk  only  from  the  beginning  of  May 
till  the  end  of  July,  when  the  fashion  and  appetite  for  it  are  over  for  the  year. 

Statement  of  a  Brewing  of  Bavarian  Bock-Beer. 

For  41  Bavarian  eimers  of  64  maass  each  (about  15  gallons  Imperial)  per  eimer,  ot 
615  gallons,  nearly  17  barrels  English  in  all : — 


Thaler,  SWg. 


32 

0 

20 

0 

0 

3 

0 

11 

11 

0 

11 

20 

16 

51 

91 

0 

7 

0 

84 

0 

Expenditure, 

32  Berlin  scheff'els  of  the  best  pale  malt  freed  from  its  acrospires, 

weighing  17^  centners,  at  1  thaler  per  centner 
48  lbs.  (Berlin)  of  the  best  Bavarian  hops 
^  lb.  Carageen  moss  for  clarifying  -  -  - 

1  lb.  Coriander-seeds  -  .  .  .  • 

I  Quart  setting  yeast. 

1  Centner  Tyrolese  pitch       -  -  -  •  • 

Malt-tax        —        _----. 
Mfidt-crushing,  fuel,  wages,  coopering,  &c. 

Thalers  of  3«.  each 
Deduct  for  the  value  of  grains  and  yeast 

Thalers  of  neat  cost  .  -  .  -  - 

This  statement  makes  the  eimer  of  the  Bavarian  bock-beer  amount  to  about  2  tha- 
lers, or  6  shillings ;  being  at  the  rate  of  nearly  5  pence  per  gallon ;  though  without 
counting  rent,  interest  of  capital,  or  profit.  It  is,  in  fact,  a  malt  or  barley  sweet  wine 
or  liqueur ;  but  a  very  cheap  one,  as  we  see  by  this  computation. 

The  chief  difference  in  the  process  for  making  bock-beer  lies  in  the  mash-wort", 
and  in  the  hops  being  boiled  a  shorter  time,  to  preserve  more  of  the  aroma,  and  acquire 
less  of  the  bitterness  of  the  hop.  The  coriander-seeds  are  coarsely  bruised,  and  added 
along  with  the  hops  and  Carageen  moss,  to  the  boiling  mash-worts,  about  twenty 
or  thirty  minutes  before  they  are  laded  or  drawn  off  into  the  mash-tun.  Sometimes 
the  hops  are  boiled  apart  in  a  little  clear  wort,  as  formerly  described.  The  bock-beer 
is  retailed  in  Munich  at  3  silver  groschen,  about  3|d.  the  seidel,  or  pot,  which  is  one 
English  pint.  The  25  gallon  cask  {imne)  is  sold  at  10  thalers,  or  30  shillings.  The 
publicans,  therefore,  have  a  very  remunerating  profit  per  pot,  even  supposing  that  they 
do  not  reduce  the  beer  with  water  like  our  London  craftsmen. 

Zimmermann  assumes  the  merit  of  having  introduced  (^arageen  moss  as  a  clarifier 
into  the  beer  manufacture.  I  do  not  know  whether  it  may  not  have  been  used  in  this 
country  for  the  same  purpose,  or  in  Ireland,  where  this  fucus  (Chondra  crispa)  grows 
abundantly.  He  says  that  1  ounce  of  it  is  sufficient  for  25  gallons  of  beer ;  and  that 
it  operates,  not  only  in  the  act  of  boiling  with  the  hops,  but  in  that  of  cooling,  as  also 
in  the  squares  and  backs  before  the  fermentation  is  begun.  Whenever  this  change, 
however,  takes  place,  the  commixture  throws  up  the  gluten  and  moss  to  the  surface  of 
the  liquid  in  a  black  scum,  which  is  to  be  skimmed  off,  so  that  the  proper  yeast  may 


K    > 


162 


BEER,  BAVARIAN. 


not  be  soiled  with  it.    It  occasions  the  separation  of  much  of  the  vegetable  slime,  or 
mucilage,  called  by  the  German  brewers  pech  (pitch). 

On  the  Clarifying  or  Clearing  of  JBeer*.— Clarifiers  act  either  chemically— by  being 
soluble  in  the  beer,  and  by  forming  an  insoluble  compound  with  the  vegetable  gluten 
and  othei  viscid  vegetable  extracts ;  gelatine  and  albumen,  under  one  shape  or  other) 

have  been  most  used ;  the  former  for  beer,  the  latter,  as  white  of  egg,  for  wine 

or  mechanically,  by  being  diffused  in  fine  particles  through  the  turbid  liquor,  and,  in 
their  precipitation,  carrying  down  with  them  the  floating  vegetable  matters.    To  this 
class  belong  sand,  bone-black  (in  some  measure,  but  not  entirely),  and  other  such 
articles.     The  latter  means  are  very  imperfect,  and  can  take  down  only  such  matters 
as  exist  already  in  an  insoluble  state ;  of  the  former  class,  milk,  blood,  glue,  calf 's-foot 
jelly,  hartshorn-shavings,  and  isinglass,  have  been  chiefly  recommended.     Calve's-foot 
jelly  is  much  used  in  many  parts  of  Germany,  where  veal  forms  so  common  a  kind  of 
butcher-meat ;  but  in  summer  it  is  apt  to   acquire  a  putrid  taint,  and  to  impart  the 
same  to  the  beer.    In  these  islands,  isinglass  swollen  and  partly  dissolved  in  vinegar, 
or  sour  beer,  is  almost  the  sole  clarifier,  called  finings,  employed.    It  is  costly,  when 
the  best  article  is  used ;  but  an  inferior  kind  of  isinglass  is  imported  for  the  brewers. 
The  solvent  or  medium  through  or  with  which  it  is  administered  is  eminently  inju- 
dicious, as  It  never  fails  to  infect  the  beer  with  an  acetous  ferment.    In  Germany 
their  tart  wine  has  been  used  hitherto  for  dissolving  the  isinglass ;  and  this  has  also  the 
same  bad  property.    Mr.  Zimmermann  professes  to  have  discovered  an  unexception- 
able solvent  in  tartaric  acid,  one  pound  of  which  dissolved  in  24  quarts  of  water  is 
capable  of  dissolving  two  pounds  of  ordinary  isinglass;  forming  finings  which  may  be 
afterward  diluted  with  pure  water  at  pleasure.     Such  isinglass  imported  from  Peters- 
burg into  Berlin  costs  there  only  3«.  per  lb.     These  finings  are  best  added,  as  already 
mentioned,  to  the  worts  prior  to  fermentation,  as  soon  as  they  are  let  in  to  the  setting- 
back  or  tun,  immediately  after  adding  the  yeast  to  it.    They  are  best  administered  by 
mixing  them  in  a  small  tub  with  thrice  their  volume  of  wort,  raising  the  mixture  into  a 
froth  with  a  whisk  (twig-besom,  in  German),  and  then  stirring  it  into  the  worts.    The 
clarification  becomes  manifest  in  the  course  of  a  few  hours,  and  when  the  fermentation 
is  completed,  the  beer  will  be  as  brilliant  as  can  be  wished;  the  test  of  which  with  the 
German  topers  is  when  they  can  read  a  newspaper  while  a  tall  glass  beaker  of  beer  is 
placed  between  the  paper  and  the  candle.     One  quart  of  finings  of  the  above  strength 
will  be  generally  found  adequate  to  the  clearing  of  100  gallons  of  well-brewed  lager- 
beer,  though  it  will  be  surer  to  use  double  that  proportion  of  finings.    The  Carageen 
moss,  as  finings,  is  to  be  cut  in  fine  shreds,  thrown  into  the  boilin?  thin  wort,  when 
the  flocks  begin  to  separate,  and  before  adding  the  hops ;  after  which  the  boiling  is 
continued  for  an  hour  and  a  half  or  two  hours,  as  need  be.     The  clarifying  with  this 
kind  of  finings  takes  place  in  the  cooler,  so  that  a  limpid  wort  may  be  drawn  off  into 
the  fermenting  back. 

Berlin  White  or  Pale  Beer  (Weias^er).— This  is  the  truly  patriotic  beverage  of 
Prussia  Proper,  and  he  is  not  deemed  a  friend  to  his  Vaterland  who  does  not  swig  it. 
It  is  brewed  from  1  part  of  barley-malt  and  5  parts  of  wheat-malt,  mingled,  moistened, 
and  coarsely  crushed  between  rollers.  This  mixture  is  worked  up  first  with  water  at 
95®  Fahr.,  in  the  proportion  of  30  quarts  per  scheffel  of  the  malt,  to  which  pasty 
mixture  70  quarts  of  boiling  water  are  forthwith  added,  and  the  whole  is  mashed  in  the 
tun.  After  it  has  been  left  here  a  little  to  settle,  a  portion  of  the  thin  liquor  is  drawn 
off  by  the  tap,  transferred  to  the  copper,  and  then  for  each  bushel  of  malt  there  is  added 
to  it  a  decoction  of  half  a  pound  of  Mlmark  hops  separately  prepared.  This  hopped 
wort,  after  half  an  hour's  boiling,  is  turned  back  with  the  hops  into  the  mash-tun,  of 
which  the  temperature  should  now  be  162^°  Fahr.,  but  not  more.  In  half  an  hour 
the  wort  is  to  be  drawn  off  from  the  grains,  and  pumped  into  the  cooler.  The  grains 
are  afterward  mashed  with  from  40  to  50  quarts  of  boiling  water  per  scheffel  of  malt, 
and  this  infusion  is  drawn  off  and  added  to  the  former  worts.  The  whole  mixture 
is  set  at  66°  Fahr.,  with  a  due  proportion  of  top  yeast  or  ordinary  barm,  and  very 
moderately  fermented.  According  to  Zimmermann,  a  very  competent  judge,  this  hia 
native  beer  is  very  apt  to  turn  sour,  and  therefore  it  must  be  very  speedily  consumed. 
This  proneness  to  acetification  is  the  character  of  all  wheat-malt  beers.  He  recom- 
mends, what  he  himself  has  made  for  many  years,  a  substitution  of  potato-starch  sugar 
for  this  sort  of  malt,  and  as  much  tartaric  acid  as  to  give  the  degree  of  tartness  peculiar 
to  the  pale  Berlin  beer,  even  in  its  best  state.  This  acid  moreover  prevents  the  beer 
from  running  into  the  acetous  fermentation. 

Potato-Beer. — The  potatoes  being  well  washed  are  to  be  rubbed  down  to  a  pulp  by 
such  a  grating  cylinder-machine  as  is  represented  inftg.  122,  where  a  is  the  hopper  for 
receiving  the  roots  (whether  potato  or  beet,  as  in  the  French  sugar-factories ;  h  is  the 
crushing  and  grinding-drum ;  c,  the  handle  for  turning  the  spur-wheel  d,  which  drive? 
the  pinion  «,  and  the  fly-wheel/;  g.  A,  is  the  frame.    The  dotted  lines  above  c,  aie  the 


BEER,  BAVARIAN. 


168 


cullender  through  which  the  pulp  passes.  Fig.UZ  is  the  stopcock  used  in  Bavaria  fojr 
tottirng  beer.  For  every  scheffel  of  potatoes  80  quarts  of  water  are  to  be  put  with 
them  into  the  copper,  and  made  to  boil. 


Crushed  malt,  to  the  amount  of  12  scheffels,  is  to  be  well  worked  about  in  the  mash- 
tun  with  360  quarts,  or  90  gallons  (English)  of  cold  water,  to  a  thick  pap,  and  then 
840  additional  quarts,  or  about  6  barrels  (English)  of  cold  water  are  to  be  successively 
introduced  with  constant  stirring,  and  left  to  stand  an  hour  at  rest. 

The  potatoes  having  been  meanwhile  boiled  to  a  fine  starch  paste,  the  whole  malt- 
mash,  thin  and  thick,  is  to  be  speedily  laded  into  the  copper,  and  the  mixture  in  it  is 
to  be  well  stirred  for  an  hour,  taking  care  to  keep  the  temperature  at  from  144**  to 
156°  Fahr.  all  the  time,  in  order  that  the  diastase  of  the  malt  may  convert  the  starch 
present  in  the  two  substances  into  sugar  and  dextrine.  This  transformation  is  made 
manifest  by  the  white  pasty  liquid  becoming  transparent  and  thin.    Whenever  this 


164 


BEER,  BAVARIAN. 


happens  the  fire  is  to  be  raised,  to  make  the  mash  boil,  and  to  keep  it  at  this  heat  for  10 
minutes,  ihe  fire  is  then  withdrawn,  the  contents  of  the  copper  are  to  be  transferred 
into  the  mash,  worked  well  there,  and  left  to  settle  for  half  an  hour;  during  which 
time  the  copper  is  to  be  washed  out,  and  quickly  charged  once  more  with  boiling 

The  clear  wort  is  to  be  drawn  off  from  the  top  of  the  tun,  as  usual,  and  boiled  as 
soon  as  possible  with  the  due  proportion  of  hops ;  and  the  boiling  water  may  be  added 
m  any  desired  quantity  to  the  drained  mash,  for  the  second  mashing.  Wort  made  in 
this  way  18  said  to  have  no  flavor  whatever  of  the  potato,  and  to  clarify  more  easily 
sacc^^A  ^^^  contaimng  a  smaller  proportion  of  gluten  relatively  to  that  of 

A  scheffel  of  good  mealy  potatoes  affords  from  26  to  27  J  lbs.  of  thick,  well-boiled 
syrup,  of  the  density  of  36°  Baum6  (see  Areometer);  and  26  lbs.  of  such  syrup  are 
equivalent  to  a  scheffel  of  malt  in  saccharine  strength.  Zimmermann  thinks  beer 
so  brewed  from  potatoes  qmte  equal,  at  least,  if  not  superior,  to  pure  malt  beer,  both  in 
appearance  and  quality.  *         '      r  » 

^^ofessor  Leo,  of  Munich,  has  given  the  following  analysis  of  two  kinds  of  Munich 


Specific  gravity 


Alcohol  -  - 
Extract  -  - 
Carbonic  acid 
Water  -    -    - 


Bock-bier. 


1-020 


HelllgerVater. 


1-030 


4-000 

8-200 

0-085 

87-393 


100-000 


5-000 
13-500 

0-077 
81-923 


100-000 


tra^t'^e'slg^^  ^^^  *^*'*'^''^  *""  *^'^  Bavarian  beer  of  Bamberg  at  only  2840  in  100.    Ex- 
The  foUowing  analyses  of  other  German  beers  are  also  by  Leo:— 


Lichtenhain. 

Upper 
Weimar. 

Ilmenatu 

Jona. 

Doable  Jena. 

Alcohol 

Albumen    -    -    -    . 

Extract 

Water 

8168 

0-048 

4-485 

92-299 

2-567 
0-020 
7-316 

90-097 

3-096 

0-079 

7-072 

89-753 

3-018 

0-045 

6144 

90-793 

2-080 

0-028 

7-153 

90-739 

100-000 

100-000 

100-000 

100-000 

100-000 

8 -5  in  100 

6-2 

5*8 

60 

6-0 

4-0 


friYr  w-^^  *!"^  extract,  in  these  analyses,  is  meant  a  mixture  of  starch,  sugar  dex- 

The  following  statement  is  from  some  of  the  published  analyses  of  other  beers  — 

English  ale ^^*^^"^ 

Burton  ----.. 
Scotch        ---.._ 

Common  London  ale  -  -  -  _ 
Brown  stout  -  -  .  .  . 
London  porter  -        -        - 

folWs^-^''''  ^  '^^  '^"  ^"""'"^"^  *°'^^«'«  "^'«^^*^"^^  ^1^«  ^«<3«  lately  by  myself  as 

acid  iere  ZeSedTtl^k  It^tn^^T  ^"  *  ^'"?  ^^^  *^"  *^^  ^"^^^^  ^^  <^^'^^'- 
ftopplr       '^'^^°^*^'''*'  ^  ^^  ^^^  «Pe«»fic  gravity  in  a  globe  with  a  capillary  bored 

V>i*  }  *^^°  ?^V**f^.  ^^^?  ^'l^^  measures  of  the  ale  with  a  test  solution  of  pure  car- 
bonate  of  soda,  to  determine  the  ouantitv  of  ft^Jrl  T^^..aor,i.     ^4-        \.-  ur    j  j^j 

cess  of  the  alklli  to  precipitate  the^Xten  •  whTck  Kvl  (  -'  ^^'t  ^  1??'^  ^"^  ^'" 
I  did  not  separate  by  a  ^Iter,  dry,  Ind  wdgh  ^         ^'''  ^^'""^  ^""^  '°^"  '^  *°'^''^'' 

3.  I  subjected  the  supersaturated  liquid  to  distillation  bv  the  heat  of  9^no  F 
chlor-zmc  bath  till  I  drew  off  all  its  alcohol  of  whioh  T  nnf^i  fti^  IF- 

grain  measures  and  the  specific  gravity  ^  ""^^^^  ^^^  ^^''^^'^^  "^  ^' 


m  a 
water- 


I. 


i 


' 


t 


BEER  (BITTER). 


165 


4.  I  evaporated  to  dryness  500  water-grain  measures  slowly  in  a  porcelain  capsule, 
t-o  determine  the  extract 


Specific  gravity 


Alcohol    - 
Extract    - 
Acetic  acid 
Water-    - 


Bavarian. 


Do.  Bock. 


1-004 


1-013 


4  00 

4-50 

0-20 

91-30 


4-50 

6-40 

0-20 

88-90 


100-00 


10000 


AIIsop's. 


1-010 


6-00 

5-00 

0-20 

88-80 


100-00 


Bass's. 


1-006 


7-00 

4-80 

0-18 

88-02 


100.00 


The  Bavarian  beers  had  been  recently  imported  from  Germany  in  casks  lined  with 

Eitch.  The  two  samples  of  English  ale  are  those  made  chiefly  for  the  Indian  market, 
ut,  being  highly  hopped,  and  comparatively  clean,  as  the  brewers  say,  have  been 
recommended  as  a  tonic  beverage  by  the  faculty.  Hodgson's  bitter  beer  was  the  ori- 
ginal of  this  quality. 

The  above  Bavarian  beers  afford  no  precipitate  of  gluten  with  carbonate  of  potash ; 
the  two  English  ales  become  mottled  thereby,  and  yield  a  small  portion  of  gluten, 
which  had  been  held  in  solution  by  the  acid,  which  is  here  estimated  as  the  acetic. 
Common  vinegar,  excise  strength,  contains  6  per  cent,  of  such  acid  as  is  stated  in  the 
above  analysis,  indicating  from  3  to  4  per  cent,  of  table  vinegar  in  the  above  varieties 
of  beer. 

Ale,  pale  or  bftter  ;  brewed  chiefly  for  tlie  Indian  market  and  for  other  tropical  coun- 
tries.— It  is  a  light  beverage,  with  much  aroma,  and,  in  consequence  of  the  regulations 
regarding  the  malt  duty,  is  commonly  brewed  from  a  wort  of  specific  gravity  1  055  or 
upwards ;  for  no  drawback  is  allowed  by  the  excise  on  the  exportation  of  beer  brewed 
from  worts  of  a  lower  gravity  than  1  -054.  This  impolitic  interference  with  the  opera- 
tions of  trade  compels  the  manufacturer  of  bitter  beer  to  employ  wort  of  a  much  greater 
density  than  he  otherwise  would  do ;  for  beer  made  from  wort  of  the  specific  gravity 
1  -042  is  not  only  better  calculated  to  resist  secondary  fermentation  and  the  other  effects 
of  a  hot  climate,  but  is  also  more  pleasant  and  salubrious  to  the  consumer.  Under  pre- 
sent circumstances  the  law  expects  the  brewer  of  bitter  beer  to  obtain  4  barrels  of 
marketable  beer  from  every  quarter  of  malt  he  uses,  which  is  just  barely  possible  when 
the  best  malt  of  a  good  barley  year  is  employed.  With  every  quarter  of  such  malt 
16  lbs  of  the  best  hops  are  used ;  so  that,  if  we  assume  the  cost  of  malt  at  60s.  per 
quarter,  and  the  best  hops  at  2«.  per  lb.,  we  shall  have,  for  the  prime  cost  of  each  barrel 
of  bitter  beer,  in  malt  15».,  in  hops  8«.,  and  together  23». ;  from  which,  on  exportation, 
we  must  deduct  the  drawback  of  6s.  per  barrel  allowed  by  the  excise,  which  brings 
the  prime  cost  down  to  18«.  per  barrel,  exclusive  of  the  expense  of  manufacture,  wear 
and  tear  of  apparatus,  capital  invested  in  barrels,  cooperage,  <fcc.,  which  constitute 
altogether  a  very  formidable  outlay.  As,  however,  this  ale  is  sold  as  high  as  from 
50a.  to  65s.  per  barrel,  there  can  be  no  doubt  that  the  bitter  ale  trade  has  long  been, 
and  still  continues,  an  exceedingly  profitable  speculation,  though  somewhat  hazard- 
ous, from  the  liability  of  the  article  to  undergo  decomposition  ere  it  finds  a  market 

The  English  ale-bibbers  were  recently  horrified  by  a  public  report,  apparently  well 
authenticated,  that  French  chemistry  was  largely  engaged  in  preparing  immense 
quantities  of  that  most  deadly  poison  strychnine,  for  the  purpose  of  drugging  the  pale 
bitter  ale,  in  such  great  vogue  at  present  in  Great  Britain  and  its  colonies.  The  fa- 
ble would  have  been  made  more  piqtuint,  by  suggesting  that  it  was  a  project  of  the 
Prince  President  of  France  to  indemnify  his  country  for  the  miseries  of  Waterloo.  It 
is  surprising  that  such  a  tale  should  have  been  told  by  any  gossip,  and  almost  incre- 
dible that  it  should  have  been  entertained  gravely  by  any  chemist  of  reputation,  for 
the  following  plain  reasons :  1.  Strychnine  is  an  exceedingly  costly  article ;  2.  It  has 
a  most  unpleasant  metallic  bitter  taste ;  3.  It  is  a  notorious  poison,  and  by  its  use  in 
any  brewery  would  ruin  the  reputation  of  the  brewer ;  4.  It  cannot  be  introduced 
into  ordinary  beer  brewed  with  hops,  because  it  is  entirely  precipitated  by  infusions 
of  that  wholesome  fragrant  herb.  In  fact,  the  quercitannic  acid  of  hops  is  incompati- 
ble with  strychnia  and  all  its  kindred  alkaloids.  Hence  hopped  beer  becomes  in  this 
respect  a  sanatory  beverage ;  refusing  to  take  up  a  particle  of  strychnia,  and  other 
noxious  drugs  of  like  character.  Had  the  two  chemists  employed  by  Messrs.  Allsopp 
to  disprove  the  above  calumny  in  respect  to  their  bitter  ale  taken  the  trouble  to 
consult  Berzelius,  Anthony  Todd  Thompson,  and  other  writers  on  strychnia,  they 
might  have  saved  themselves  the  vain  attempt  to  dissolve  strychnia  in  the  said  beer 
for  it  all  remains  at  the  bottom  in  combination  with  the  quercitannic  acid  so  abun- 
dantly present     Were  the  nux  vomica  powder,  from  which  strychnia  is  extracted. 


166 


BERRIES  OF  AVIGNON. 


even  stealthily  thrown  into  the  mash  tun,  its  dangerous  principle  would  be  all  infal- 
libly  thrown  down  with  the  grounds  in  the  subsequent  hop-boiL 

"Hie  Board  of  Excise  or  Inland  Revenue  having  a  few  years  ago,  with  delusive  libe- 
rality, permitted  the  legislature  to  grant  leave  to  use  sugar  in  the  place  of  barley 
malt  in  breweries,  an  extensive  sugar  merchant  in  London,  hoping,  under  this  pre- 
tended boon,  to  acquire  a  new  and  wealthy  class  of  customers,  employed  me  to  ascer- 
tain by  experiment  the  relative  values  of  malt  and  sugar  for  the  manufacture  of  beer. 
Ten  samples  of  muscovado  sugar  of  several  qualities  were  examined,  and  were  found 
to  vary  very  slightly  in  the  proportions  of  alcohol  they  could  furnish  by  fermentation 
in  a  brewers  tun;  the  average  being  12  gallons  of  proof  spirit  for  112  lbs.  of  the  su- 
gar ;  whereas  an  equal  quantity  of  proof  spirit  couM  be  obtained  from  4-8  bushels  of 
malt.  One  pound  of  malt  yields  |  of  a  lb  of  extract,  capable  of  making  as  much  beer 
as  that  weight  of  sugar.  On  comparing  the  actual  prices  of  sugar  and  malt,  we  shall 
see  how  ruinous  a  business  it  would  be  to  use  sugar  instead  of  malt  in  a  brewery,  and 
hence  the  delusiveness  of  the  excise  generosity  towards  the  beer  trade. 

BEET-ROOT  SUGAR.     See  Sugar. 

BELL  METAL,  an  alloy  of  copper  and  tin.    See  Copper 

BELLOWS.    See  Mctallurgy. 

BEN  OIL.    SeeOiLOFBKN. 

BENGAL  STRIPES.  Ginghams;  a  kind  of  cotton  cloth  woven  with  colored 
stripes. 

BENJAMIN  or  BENZOIN.  {Benjoin,  Fr. ;  Benzoe,  Germ.)  A  species  of  resin  used 
chiefly  in  perfumery.  It  is  extracted  by  incision  from  the  trunk  and  branches  of  the 
styrax  benzoin,  which  grows  in  Java,  Sumatra,  Santa  F^  and  in  the  kingdom  of  Siam. 
The  plant  belongs  to  the  decandria  monogynia  of  Linnceus,  and  the  natural  family  of 
the  ebenacese.  It  hardens  readily  in  the  air,  and  comes  to  us  in  brittle  masses,  whose 
fracture  |)resents  a  mixture  of  red,  brown,  and  white  grains  of  various  sizes,  which, 
when  white,  and  of  a  certain  shape,  have  been  called  amygdaloid,  from  their  resem- 
blance to  almonds.     The  sorted  benzoin  is,  on  the  other  hand,  very  impure. 

The  fracture  of  benzoin  is  conchoidal,  and  its  lustre  greasy :  its  specific  gravity  va- 
ries from  1-063  to  1-092.  It  has  an  agreeable  smell,  somewhat  like  vanilla,  which  is 
most  manifest  when  it  is  ground.  It  enters  into  fusion  at  a  gentle  heat,  and  then  ex- 
hales a  white  smoke,  which  may  be  condensed  into  the  acicular  crystals  of  benzoic 
acid,  of  which  it  contains  18  parts  in  the  hundred.  Stoltze  recommends  the  f(dIow- 
ing  process  for  extracting  the  acid :  The  resin  is  to  be  dissolved  in  3  parts  of  alcohol, 
the  solution  is  to  be  introduced  into  a  retort,  and  a  solution  of  carbonate  of  soda  dis- 
solved in  dilute  alcohol  is  to  be  gradually  added  to  it,  till  the  free  acid  be  neutralized; 
and  then  a  bulk  of  water  equal  to  double  the  weight  of  the  benzoin  is  to  be  poured 
in.  The  alcohol  being  drawn  off  by  distillation,  the  remaining  liquor  contains  the 
acid,  and  the  resin  floating  upon  it  may  be  skimmed  off  and  washed,  when  its  weight 
will  be  found  to  amount  to  about  80  per  cent,  of  the  raw  material.  The  benzoin  con- 
tains traces  of  a  volatile  oil,  and  a  substance  soluble  in  water,  at  least  through  the 
agency  of  carbonate  of  potash.  Ether  does  not  dissolve  benzoin  completely.  The 
fat  and  volatile  oils  dissolve  very  little  of  it. 

Unverdorben  has  found  in  benzoin,  besides  benzoic  acid,  and  a  little  volatile  oil,  no 
less  than  three  different  kinds  of  resin,  none  of  which  has,  however,  been  turned  as 
yet  to  any  use  in  the  arts. 

Benzoin  is  of  great  use  in  perfumery,  as  it  enters  into  a  number  of  preparations; 
aniong  which  may  be  mentioned  fumigating  pastilles,  fumigating  cloves  (called  also 
nails),  poudre  d  la  marechale,  <fec.  The  alcoholic  tincture,  mixed  with  water,  forms 
virginal  milk.  Benzoin  enters  also  into  the  composition  of  certain  varnishes  employed 
for  snuff-boxes  and  walking-sticks,  in  order  to  give  these  objects  an  agreeable  smell 
when  they  become  heated  in  the  hand.  It  is  likewise  added  to  the  spirituous  solution 
of  isinglass,  with  which  the  best  court-plaster  is  made. 

BERLIN  BLUE     Prussian  blue,  which  see. 

BERRIES  OF  AVIGNON,  and  Persian  Berries.  {Graines  d' Avignon,  Fr.;  Oelhheere^x, 
Germ.)  A  yellowish  dye-drug,  the  fruit  of  the  rhamnus  infectorius,  a  plant  cultivated 
m  Provence,  Languedoc,  and  Dauphin6,  for  the  sake  of  its  berries,  which  are  plucked 
before  they  are  ripe,  while  they  have  a  greenish  hue.  Another  variety  comes  from 
Persia,  whence  its  trivial  name :  it  is  larger  than  the  French  kind,  and  has  superior 
properties.  The  principal  substances  contained  in  these  berries  are :  1.  A  coloring 
matter,  which  is  united  with  a  matter  insoluble  in  ether,  little  soluble  in  concentrated 
alcohol,  and  very  soluble  in  water :  it  appears  to  be  volatile.  2.  A  matter  remarkable 
for  its  bitterness,  which  is  soluble  in  water  and  alcohol.  3.  A  third  principle  in  small 
quantity.  A  decoction  of  one  part  of  the  Avignon  or  Persian  beriy  in  ten  of  water 
affords  a  brown-yellow  liquor,  bordering  upon  green,  having  the  smell  of  a  vegetable 
extract^  and  a  slightly  bitter  taste. 


I 


BIRDLIME. 


16T 


With  gelatine  that  decoction  gives,  after  some  Umc,  a  slight  precipitate,— 

-  alkalis  -  -  -  ■  •3;^"^7^'J^ 

j^gj^g  ....  a  slight  muddiness, 

'-    lime-water         .             -             -             -  a  greenish-yellow  tint^ 
^lu^                   ....  a  yellow  color, 

—  red  sulphate  of  iron       -  -  -  an  olive-green  color, 

—  sulphate  of  copper,        -  -  -  an  olive  color  .^,   ^    ,.  , , 

-  proto-muriate  oif  tin      -  -  -  a  greenish  yellow  with  a  slight 
*^  precipitate.       (See    Calico 

PbintinoX 
BERYL.     A  beautiful  mineral  or  gem,  of  moderate  price,  usuaUy  of  a  green  color 

of  various  shades,  passing  into  honey-yellow  and  sky  blue.  .      f       ^^     * 

BEZOAR      The  name  of  certain  concretions  found  in  the  stomachs  ot  animals,  lo 

which  many  fanciful  virtues  were  formerly  ascribed.     They  are  interesting  only  to  the 

chemical  pathologist  »  j 

BICARBONATE  OF  POTASH  AND  OF  SODA.  These  salts,  so  much  used 
in  medicine,  may,  according  to  M.  Behrens,  be  very  readily  prepared  by  gradually 
adding  acetic  acid  to  a  strong  solution  of  their  carbonates ;  that  of  soda  bemg  hot. 
The  carbonic  acid,  at  the  moment  of  its  disengagement,  by  the  stronger  affinity  o'^ho 
acetic  for  the  alkalis,  combines  with  a  portion  of  them  to  form  bicarbonates,  which 
fall  to  the  bottom  of  the  vessel  in  which  the  mixture  is  made.  The  supernatant 
acetate  being  separated  by  decantation,  the  residuary  bicarbonate  is  to  be  pressed  in 
linen  washed  with  ice-cold  water,  and  dried.  This  process  may  be  practised  by  the 
chamber  chemist,  but  will  not  afford  the  bicarbonates  at  so  cheap  a  rate  as  the  ordmary 
modes  of  manufacture.  But  a  far  better  method  of  forming  these  two  salts  is  by  ex- 
posing each  of  them  in  chambers  on  extensive  surfaces,  perforated  with  small  holes,  to 
an  atmosphere  of  carbonic  acid,  generated  by  the  combustion  of  coke,  and  purified  by 
being  passed  through  cold  water,  by  the  action  of  an  air-pump  worked  by  a  steam- 

SlLE    {Bile,  Fr. ;  Galle,  Germ.)    The  secreted  liquor  of  the  liver  in  animals.    For 
an  account  of  the  uses  of  animal  bile  in  the  arts,  see  Gall. 
Bile  (ox's)  is  composed,  according  to  Berzelius, 


1.  Of  biline,  fellinic  acid,  and  fat  of  gall 

2.  Mucus  -  -  - 

3.  Of  alkali  combined  with  biline,  «fec 

4.  Muriate  of  soda,  extractive  matter 
6.  Phosphate  of  soda :  do.  of  lime,  Ac 
6,  Water  ... 


Thenard's  analysis  gives : — 

1.  Resin  of  bile  and  picromel  (acid  gallenate  of  soda) 
Coloring  matter  .  -  -  - 
Soda  .  .  -  -  - 
Phosphate  of  soda  .  -  -  - 
Muriate  of  soda  .  -  .  • 
Sulphate  of  soda  ...» 
of  lime  .            -            -  - 


2. 
8. 
4. 
5. 
6. 
1. 
8. 
9. 


Traces  of  oxide  of  iron 
Water 


8-00 
0-30 
0-41 
0-Y4 
0.11 
90-44 

100-00 


10-64 
0-50 
0-50 
0-25 
0-40 
0-10 
0-16 

87-56 
100-00 


A  substance  may  be  tested  for  bile  by  dropping  into  it  two-thirds  of  its  bulk  of  oil 
of  vitriol  very  slowly,  so  that  the  heat  does  not  exceed  122°  Fahr.,  adding  a  few  drops 
of  syrup,  and  shaking  the  mixture ;  when  it  should  assume  a  deep  violet  hue. 

BIRDLIME  {Glu,  Fr. ;  Vogelleim,  Germ.)  The  best  birdlime  may  be  made  from 
the  middle  bark  of  the  holly,  boiled  seven  or  eight  hours  in  water,  till  it  is  soft  and 
tender,  then  laid  by  heaps  in  pits  under  ground,  covered  with  stones  after  the  water 
is  drained  from  it.  There  it  must  be  left  during  two  or  three  weeks,  to  ferment  in  the 
summer  season,  and  watered,  if  necessary,  till  it  passes  into  a  mucilaginous  state.  It 
is  then  to  be  pounded  in  a  mortar  to  a  paste,  washed  in  running  water,  and  kneaded 
till  it  be  free  from  extraneous  matters.  It  is  next  left  for  four  or  five  days  in  earthen 
vessels  to  ferment  and  purify  itself,  when  it  is  fit  for  use.  Birdlime  may  be  made  by 
the  same  process  from  the  mistletoe  {yihurnum  lantana),  young  shoots  of  elder,  and 
the  barks  of  other  vegetable?,  as  well  as  from  most  parasite  plants. 

Good  birdlime  is  of  a  greenish  color,  and  sour  flavor,  somewhat  resembling  that  of 
linseed  oil ;  gluey,  stringy,  and  tenacious.     By  drying  in  the  air  it  becomes  brittle  and 


II 


168 


BISCtJITS. 


it 


m 


may  be  powdered  ;  but  its  viscosity  may  be  restored  by  moistening  it.  It  has  an 
acid  reaction  with  litmus  paper.  It  contains  resin,  mucilage,  a  little  free  acid,  color- 
ing and  extractive  matter.    The  resin  has  been  called  Viscine. 

All  the  parts  of  the  mistletoe  contain  a  peculiar  viscid  gluey  pubstance,  which  they 
yield  by  decoction,  particularly  of  the  bark  and  green  portions ;  as  also  from  the  ex- 
pressed juice  of  the  bark  or  berries,  when  it  is  kneaded  with  the  fingers  under  water. 
The  birdlime  is  thus  obtained  in  the  form  of  a  white  opaque  mass,  sticking  to  the 
fingers.  It  may  also  be  extracted  from  the  berries  of  the  mistletoe  by  means  of  ether, 
repeatedly  applied,  digested  with  them.  It  dissolves  at  first  a  mixture  of  green  wax 
and  birdlime,  but  afterwards  birdlime  alone.  By  distilling  off  the  ether,  the  birdlime 
renaains  colorless  and  nure.  Birdlime  may  be  considered  as  a  kind  of  viscid  resin 
which  does  not  dry,  and  resembling  in  this  respect  an  ointment  of  oil  or  lard  and 
rosin  melted  t(^ether — the  old  basilicon  of  the  surgeon.  Alcohol,  even  boiling  hot, 
dissolves  hardly  any  birdlime ;  but  merely  its  waxy  impurities,  which  it  deposits  in 
flocks  on  cooling.  It  is  soluble  in  the  oils  of  rosemary  and  turpentine,  as  also  in 
petroleum.  Heated  with  the  lejr  of  caustic  potash,  it  forms  a  compound  soluble  in 
alcohol.     Nitric  acid  converts  it  into  oxalic  acid,  and  into  a  fat  which  solidifies. 

Macaire  has  examined  a  substance  which  exudes  from  the  receptacle  and  involucru 
of  the  atractylis  gummifera,  and  describes  it  as  the  pure  matter  of  birdlime,  which  he 
styles  viscine.  It  is  said  to  be  composed  in  100  parts  of  76*6  carbon,  9*2  hydrogen, 
and  16*2  oxygen.  Common  birdlime  may  be  regarded  as  a  mixture  of  viscine,  vege- 
table mucilage,  and  vinegar.  The  young  shoots  of  the^ca«  elastica  afford  a  milky 
juice,  which  is  viscine,  while  the  old  branches  afford  a  juice  rich  in  caoutchouc. 

BISCUITS.  For  the  following  account  of  the  mechanical  system  of  baking  biscuits 
for  the  ro^al  navy,  I  am  indebted  to  the  ingenious  inventor,  Thomas  Grant,  Escj. 

Ships'  biscuits  are  now  made  by  machinery  ;  and  one  of  the  reasons  for  this  has 
been  that  the  manual  preparation  of  them  was  too  slow  and  too  costly  during  the  last 
^ar.  A  landsman  knows  very  little  of  the  true  value  of  a  biscuit :  with  a  seaman, 
biscuit  is  the  only  bread  that  he  eats  for  months  together.  There  are  many  reasons 
whjr  common  loaves  of  bread  could  not  be  used  during  a  long  voyage ;  because,  con- 
taining a  fermenting  principle,  they  would  soon  become  musty  and  unfit  for  food,  if 
made  previous  to  the  voyage ;  while  the  preparation  of  them  on  board  ship  is  subject 
to  insuperable  objections.  Biscuits  contain  no  leaven,  and,  when  well  baked  through- 
out, they  suffer  little  change  during  a  long  voyage. 

ITie  allowance  of  biscuit  to  each  seaman  on  board  a  queen's  ship  is  a  pound  per  day 
(averaging  six  biscuits  to  the  pound).  The  supply  of  a  man-of-war  for  several  months 
is,  consequently,  very  large ;  and  it  often  happened  during  the  last  war  that  the  diffi- 
culty of  making  biscuits  fast  enough  was  so  great,  that  at  Portsmouth  wagon  loads 
were  unpacked  in  the  streets  and  conveyed  on  board  ships. 

We  shall  now  describe  the  mode  of  making  biscuits  by  hand ;  and  afterwards  speak 
of  the  improved  method.    The  bakehouse  at  Gosport  contained  nine  ovens,  and  to  each 
was  attached  a  gang  of  five  men — the  "turner,"  the  "mate,"  the  "driver,"  the  "break- 
man,"  and  the  "idleman."     The  requisite  proportions  of  flour  and  water  were  put  into 
a  large  trough,  and  the  "driver,"  with  his  naked  arms,  mixed  the  whole  up  together 
into  the  form  of  dough — a  very  laborious  operation.     The  dough  was  tlien  taken  from 
the  trough  and  pxit  on  a  wooden  platform  called  the  break :  on  this  platform  worked 
a  lever  called  the  break-staff,  five  or  six  inches  in  diameter,  and  seven  feet  long ;  one 
end  of  this  was  loosely  attached  by  a  kind  of  staple  to  the  wall,  and  the  breakman, 
riding  or  sitting  on  the  other  end,  worked  this  lever  to  and  fro  over  the  dough,  by  an 
uncouth  jumping  or  shuffling  movement.     When  the  dough  had  become  kneaded  by 
this  barbarous  method  into  a  thin  sheet,  it  was  removed  to  the  moulding-board,  and 
cut  into  slips  by  means  of  an  enormous  knife  ;  these  slips  were  then  broken  into  pieces, 
each  large  enough  for  one  biscuit,  and  then  worked  into  a  circular  form  by  the  hand. 
As  each  biscuit  was  shaped  it  was  handed  to  a  second  workman,  who  stamped  the 
king's  mark,  the  number  of  the  oven,  <fec.,  on  the  biscuit.     The  biscuit  was  then 
docked,  that  is,  pierced  with  holes  by  an  instrument  adapted  to  the  purpose.     Tlie 
finishing  part  of  the  process  was  one  in  which  remarkable  dexterity  was  displayed. 
A  man  stood  before  the  open  door  of  the  oven,  having  in  his  hand  the  handle  of  a  long 
shovel  called  a  peel,  the  other  end  of  which  was  lying  flat  in  the  oven.     Another 
man  took  the  biscuits  as  fast  as  they  were  formed  and  stamped,  and  jerked  or  threw 
them  into  the  oven  with  such  undeviating  accuracy  that  they  should  always  fall  on 
the  peeL     The  man  with  the  peel  then  arranged  the  biscuits  side  by  side  over  the 
whole  floor  of  the  oven.     Nothing  could  exceed  (in  manual  labor  alone)  the  regu- 
larity with  which  this  was  all  done.     Seventy  biscuits  were  thrown  into  the  oven  and 
regularly  arranged  in  one  minute ;  the  attention  of  each  man  being  vigorously  directed 
to  his  own  department;  for  a  delay  of  a  single  second  on  the  part  of  any  one  man 
would  have  disturbed  the  whole  gang.     The  biscuits  do  not  require  many  minutes' 


BISCUITS. 


169 


/ 


i» 


barfmg  ;  and  as  the  oven  is  kept  open  during  the  time  that  it  is  being  filled,  the  biscuits 
first  thrown  in  would  be  overbaked  were  not  some  precaution  taken  to  prevent  it. 
The  moulder  therefore  made  those  which  were  to  be  first  thrown  into  the  oven  larger 
than  the  subsequent  ones,  and  diminished  the  size  by  a  nice  gradation. 

The  mode  in  which,  since  about  the  year  1831,  ships'  biscuits  have  been  made  by 
machinery  invented  by  T.  T.  Grant,  Esq.,  of  the  Royal  Clarence  yard,  is  this  :  the 
meal  or  flour  is  conveyed  into  a  hollow  cylinder  four  or  five  feet  long  and  about 
three  feet  in  diameter,  and  the  water,  the  quantity  of  which  is  regulated  by  a  gauge 
admitted  to  it ;  a  shaft,  armed  with  long  knifes,  works  rapidly  round  in  the  cylinder, 
with  such  astonishing  efl'ect  that,  in  the  short  space  of  three  minutes,  340  pounds 
of  dough  are  produced,  infinitely  better  made  than  that  mixed  by  the  naked  arms  of 
a  man.  The  dough  is  removed  from  the  cylinder  and  placed  under  the  breaking- 
rollers  ;  these  latter,  which  perform  the  ofiice  of  kneading,  are  two  in  number,  and 
weigh  15  cwt.  each;  they  are  rolled  to  and  fro  over  the  surface  of  the  dough  by 
means  of  machiner)',  and  in  five  minutes  the  dough  is  perfectly  kneaded.  The  sheet 
of  dough,  which  is  about  two  inches  thick,  is  then  cut  into  pieces  half  a  yard  square, 
which  pass  under  a  second  set  of  rollers,  by  which  each  piece  is  extended  to  the 
size  of  six  feet  by  three,  and  reduced  to  the  proper  thickness  for  biscuits.  The 
sheet  of  dough  is  now  to  be  cut  up  into  biscuits,  and  no  part  of  the  operation  is 
more  beautiful  than  the  mode  by  which  this  is  accomplished.  The  dough  is  brought 
under  a  stamping  or  cutting-out  press,  similar  in  effect,  but  not  in  detail,  to  that  by 
which  circular  pieces  for  coins  are  cut  out  of  a  sheet  of  metal.  A  series  of  sharp 
knives  are  so  arranged  that,  by  one  movement,  they  cut  out  of  a  piece  of  dough  a 
yard  square  about  sixty  hexagonal  biscuits.  The  reason  for  a  hexagonal  (six-sided) 
shape  is,  that  not  a  particle  of  waste  is  thereby  occasioned,  as  the  sides  of  the  hex- 
agonals  accurately  fit  into  those  of  the  adjoining  biscuits  ;  whereas  circular  pieces 
cut  out  of  a  large  surface  always  leave  vacant  spaces  between.  That  a  flat  sheet  can 
be  divided  into  hexagonal  pieces  without  any  waste  of  material  is  obvious. 

Each  biscuit  is  stamped  with  the  queen's  mark,  as  well  as  punctured  with  holes 
by  the  same  movement  which  cuts  it  out  of  the  piece  of  dough.  The  hexagonal 
cutters  do  not  sever  the  biscuits  completely  asunder ;  so  that  a  whole  sheet  of  them 
can  be  put  into  the  oven  at  once  on  a  large  peel  or  shovel  adapted  for  the  purpose. 
About  fifteen  minutes  are  sufficient  to  bake  them ;  they  are  then  withdrawn  and 
broken  asunder  by  the  hand. 

The  corn  for  the  biscuits  is  purchased  at  the  markets,  and  cleaned,  ground,  and 
dressed ;  at  the  government  mills ;  in  quality  it  is  a  mixture  of  fine  flour  and  mid- 
dlings, the  bran  and  pollard  being  removed.  The  ovens  for  baking  are  formed  of 
fire-brick  and  lile,  with  an  area  of  about  160  feet.  About  112  lbs.  weight  of  biscuits 
are  put  into  the  ovens  at  once.  This  is  called  a  suit,  and  is  reduced  to  about  110  lbs. 
by  the  baking.  From  twelve  to  sixteen  suits  can  be  baked  in  each  oven  every  day,  or 
after  the  rate  of  224  lbs.  per  hour.  The  men  engaged  are  dressed  in  clean  check 
shirts  and  white  linen  trowsers,  apron,  and  cap ;  and  every  endeavor  is  made  to 
observe  the  most  scrupulous  cleanliness. 

We  may  now  make  a  few  remarks  on  the  comparative  merits  of  the  hand  and  the 
machine  processes.  If  the  meal  and  the  water  with  which  the  biscuits  are  made  be 
not  thoroughly  mixed  up,  there  will  be  some  parts  moister  than  others.  Now,  it  was 
formerly  found  that  the  dough  was  not  well  mixed  by  the  arms  of  the  workman  ;  the 
consequence  of  which  was  that  the  dry  parts  became  burnt  up,  or  else  that  the  moist 
parts  acquired  a  peculiar  kind  of  hardness  which  the  sailors  called  "  flint :"  these  defects 
are  now  removed  by  the  thorough  mixing  and  kneading  which  the  ingredients  receive 
by  the  machine. 

We  have  seen  that  450  lbs.  of  dough  may  be  mixed  by  the  machine  in  four  minutes, 
and  kneaded  in  five  or  six  minutes  ;  we  need  hardly  say  how  much  quicker  this  is  than 
men's  hands  could  effect  it.  The  biscuits  are  cut  out  and  stamped  sixty  at  a  time, 
instead  of  singly :  besides  the  time  thus  saved,  the  biscuits  become  more  equally 
baked,  by  the  oven  being  more  speedily  filled.  The  nine  ovens  at  Gosport  used  to 
employ  45  men  to  produce  about  1,500  lbs.  of  biscuit  per  hour  ;  16  men  and  boys  will 
now  produce,  by  the  same  number  of  ovens,  2,240  lbs.  of  biscuits  (one  ton)  per  hour. 
The  comparative  expense  is  thus  stated :  Under  the  old  system,  wages,  and  wear 
and  tear  of  utensils,  cost  about  1*.  Qd,  per  cwt.  of  bis  cuit :  under  the  new  system,  the 
cost  is  5rf. 

The  bakehouses  at  Deptford,  Gosport,  and  Plymouth,  could  produce  7,000  or  8,000 

tons  of  biscuits  annually,  at  a  saving  of  12,000/.  per  annum  from  the  cost  under  the 

old  system.     The  advantages  of  machine-made  over  hand-made  biscuits,  therefore,  are 

many :    quality,  cleanliness,  expedition,  cheapness,  and  independence  of  government 

contractors. 

Fig.  124  represents  the  biscuit  machinery,  as  executed  beautifully  by  Messrs.  Rennie, 
Vol.  I. 


m 


\ 


I 
N 

1 

1^    t' 


170 


BISMUTH. 


engineers,     a,  is  the  breaking  roller,  table  and  roller ;  6,  the  finishing  roller,  table  an^ 
roUer;  c,  c,  docking  machines  for  stamping  out  the  biscuits;  d,  mixing  machine  for 


making  the  dough ;  e,  spur  pinion  to  engine  shaft ;  /,  spur  wheel ;  g,  g,  bevel  mitre- 
wheel*  to  give  the  upright  motion ;  A,  A,  bevel- wheels  for  working  the  mixing  machine ; 
i,  i,  t,  ditto  for  communicating  motion  to  the  rolling  machines;  j,  j,  k,  the  crank  shaft; 
/,  I,  connecting  rods;  m,  m,  pendulums  for  giving  motion  to  rollers;  n,  n,  clutches  for 
connecting  either  half  of  the  machinery  to  the  other. 

BISMUTH.  {Bismuth,  Fr. ;  Wismuth,  Germ.)  Called  also  marcasite  and  tin-glass. 
It  was  shown  to  be  a  metal  somewhat  different  from  lead,  by  G.  Agricola,  in  1646 ;  Stahl 
and  Dufay  proved  its  peculiarity;  but  it  was  more  minutely  distinguished  by  Pott  and 
GeofFroy  about  the  middle  of  the  last  century.  It  is  a  rare  substance,  occurring  native, 
as  an  oxide,  under  the  name  of  bismuth  ochre ;  as  a  sulphuret,  called  bismuth  glance ;  as 
a  sulphuret  with  copper,  called  copper  bismuth  ore ;  as  also  with  copper  and  lead,  called 
needle  ore.  It  is  found  associated  likewise  with  selenium  and  tellurium.  The  native 
metal  occurs  in  various  forms  and  colors,  as  white,  reddish,  and  variegated;  in  primi- 
tive and  floetz  formations,  along  with  the  ores  of  cobalt,  nickel,  copper,  silver  and 
bismuth  ochre ;  at  the  Saxon  Erzegebirge,  near  Schneeberg,  and  Job.  Georgenstadt ;  also 
in  Bohemia,  Baden,  Wurtemberg,  Hessia,  Sweden,  Norway,  England,  and  France. 

The  production  of  thislnetal  is  but  a  limited  object  of  the  smelting- works,  of  the 
Saxon  Erzegebirge  at  Schneeberg.  It  there  occurs,  mixed  with  cobalt  speiss,  in  the 
proportion  of  about  7  per  cent,  upon  the  average,  and  is  procured  by  means  of  a  pe- 
culiar furnace  of  liquation,  which  is  the  most  economical  method,  both  as  to  savmg 
fuel,  and  oxidizeraent  of  the  bismuth. 

The  bismuth  eliquation  furnace  at  Schneeberg  is  represented  in  Jigs.  126, 126,  and  127, 
of  which  the  first  is  a  view  from  above,  the  second  a  view  in  fronts  and  the  third  a  trans- 
verse section  in  the  dotted  line  a  b  oijig.  126.  a,  is  the  ash-pit ;  6,  the  fire-place ;  c,  the 
eliquation  pipes;  d,  the  grate  of  masonry  or  brickwork,  upon  which  the  fuel  is  thrown 
through  the  fire-door  e  e.  The  anterior  deeper  lying  orifice  of  the  eliquation  pipes  is  closed 
with  the  clay-plate/;  which  has  beneath  a  small  circular  groove,  through  which  the 
li(]^uefied  metal  flows  off.  gh&  wall  extending  from  the  hearth-sole  nearly  to  the  anterior 
orifices  of  the  liquation  pipes,  in  which  wall  there  are  as  many  fire-holes,  A,  as  there  are 
pipes  in  the  furnace :  t  are  iron  pans,  which  receive  the  fluid  metal ;  A,  a  wooden  water- 


J 


BISMUTH. 


m 


trough,  in  which  the  bismuth  is  granulated  and  cooled ;  I,  the  posterior  and  h^^«  »y"™« 
aperluJes  of  the  eliquation  pipes,  shut  merely  with  a  sheet-iron  cover.  The  granulation* 
of  bismuth  drained  from  the  posterior  openings  fall  upon  the  flat  surfaces  m,  and  then 

126 


_@Q®P® 


19  Q  i3  0  Q 
3 


Into  the  water-trough,  n  n  are  draught-holes  in  the  vault  between  the  two  pipes,  whidi 
Berve  for  increasing  or  diminishing  the  heat  al  pleasure. 

The  ores  to  be  eliquated  (sweated)  are  sorted  by  han  1  from  the  gangue,  broken  into 
pieces  about  the  size  of  a  hazel  nut,  and  introduced  into  the  ignited  pipes  ;  one  charge 
consisting  of  about  \  cwt. ;  so  that  the  pipes  are  filled  to  half  their  diameter,  and  three 
fourths  of  their  length.  The  sheet-iron  door  is  shut,  and  the  fire  strongly  urged,  whereby 
the  bismuth  begins  to  flow  in  ten  minutes,  and  falls  through  the  holes  in  the  clay-plates 
into  hot  pans  containing  some  coal-dust.  Whenever  it  runs  slowly,  the  ore  is  stirred 
round  in  the  pipes,  at  intervals  during  half  an  hour,  in  which  time  the  liquation  is  usually 
finished.  The  residuum,  called  bismuth  barley  (graupen),  is  scooped  out  with  iron  rakes 
into  a  water  trough  ;  the  pipes  are  charged  afresh ;  the  pans,  when  full,  have  their  con- 
tents cast  into  moulds,  forming  bars  cf  from  25  to  50  pounds  weight.  About  20  cwt.  of 
ore  are  smelted  in  8  hours,  with  a  consumption  of  63  Leipzic  cubic  feet  of  wood.  The 
total  production  of  Shneeberg,  in  1830,  was  9800  lbs.  The  bismuth  thus  procured  by- 
liquation  upon  the  great  scale,  contains  no  small  admixture  of  arsenic,  iron,  and  some 
other  metals,  from  which  it  may  be  freed  by  solution  in  nitric  acid,  precipitation  by  water, 
and  reduction  of  the  subnitrated  oxyde  by  black  flux.  By  exposing  the  crude  bismuth 
for  some  time  to  a  dull  red  heat,  under  charcoal,  arsenic  is  expelled. 

Bismuth  is  white,  and  resembles  antimony,  but  has  a  reddish  tint ;  whereas  the  latter 
metal  has  a  blueish  cast.  It  is  brilliant,  crystallizes  readily  in  small  cubical  facets,  b 
very  brittle,  and  may  be  easily  reduced  to  powder.  Its  specific  gravity  is  9*83  ;  and  by 
hammering  it  with  care,  the  density  may  be  increased  to  9*8827.  It  melts  at  480®  Fahr., 
and  may  te  cooled  6  or  7  degrees  below  this  point  without  fixing ;  but  the  moment  it  be- 
gins to  solidify,  the  temperature  rises  to  480°,  and  continues  stationary  till  the  whole 
mass  is  congealed.    When  heated  from  3^  to  212®,  it  expands  _-|^  in  length.     When 

pure  it  aflbrds  a  very  valuable  means  of  adjusting  the  scale  of  high-ranged  thermometers. 
At  strong  heats  bismuth  volatilizes,  may  be  distilled  in  close  vessels,  and  is  thus  obtained 
in  crystalline  laminae. 

The  alloy  of  bismuth  and  lead  in  equal  parts  has  a  density  of  10*709,  being  greater 
than  the  mean  of  the  constituents ;  it  has  a  foliated  texture,  is  brittle,  and  of  the  same 
color  as  bismuth.  Bismuth,  with  tin,  forms  a  compound  more  elastic  and  sonorous  than 
the  tin  itself,  and  is  therefore  frequently  added  to  it  by  the  pewterers.  With  1  of  bis- 
muth and  24  of  tin,  the  alloy  is  somewhat  malleable ;  with  more  bismuth,  it  is  brittle. 
When  much  bismuth  is  present,  it  may  be  easily  parted  by  strong  muriatic  acid,  which 
dissolves  the  tin,  and  leaves  the  bismuth  in  a  black  powder.  It  has  been  said,  that  an 
alloy  of  tin,  bismuth,  nickel,  and  silver  hinders  iron  from  rusting.  {Erdmann's  Journal.) 
The  alloy  of  bismuth  with  tin  and  lead  was  first  examined  by  Sir  I.  Newton,  and  has 
been  called  ever  since  fusible  metal.  Eight  parts  of  bismuth,  5  of  lead,  and  3  of  tin,  melt 
at  the  moderate  temperature  of  202°  F. ;  but  2  of  bismuth,  1  of  lead,  and  1  of  tin,  melt 
at  200*75''  F.  according  to  Rose.  A  small  addition  of  mercury  of  course  aids  the  fusi- 
bility. Such  alloys  serve  to  take  casts  of  anatomical  preparations.  An  alloy  of  1  bis- 
muth, 2  tin,  and  1  lead,  is  employed  as  a  soft  soider  by  the  pewterers ;  and  the  same 
has  been  proposed  as  a  bath  for  tempering  steel  instruments.  Cake-moulds,  for  the 
manufacturers  of  toilet  soaps,  are  made  of  the  same  metal ;  as  also  excellent  cliches  for 
stereotype,  of  3  lead,  2  tin,  and  5  bismuth ;  an  alloy  which  melts  at  199°  F.  This  com- 
pound should  be  allowed  to  cool  upon  a  piece  of  pasteboard,  till  it  becomes  of  a  doughy 
consistence,  before  it  is  applied  to  the  mould,  to  receive  the  impress  of  the  stamp. 


* 


m 


BITUMEN. 


BITUMEN. 


173 


The  employment  of  plates  of  fusible  metal  as  safety  rondellesy  to  apertures  in  the  tope 
of  steam  boilers,  has  been  proposed  in  France,  because  they  would  melt  and  give  way  at 
elevations  of  temperature  under  those  which  would  endanger  the  bursting  of  the  vessel ; 
the  fusibility  of  the  alloy  being  proportioned  to  the  quality  of  steam  required  for  the  en- 
gine.  It  has  been  found,  however,  that  boilers,  apparentlv  secured  in  this  way,  burst, 
while  the  safety  discs  remained  entire ;  the  expansive  force  of  the  steam  causing  explo- 
sion so  suddenly,  that  the  fusible  alloy  had  not  time  to  melt  or  give  way. 

There  are  two,  perhaps  three,  oxydes  of  bismuth;  the  first  and  the' third,  or  the  sub- 
oxyde  and  super-oxyde,  are  merely  objects  of  chemical  curiosity.  The  oxyde  proper  occurs 
native,  and  may  be  readily  formed  by  exposing  the  metal  to  a  red-white  heat  in  a  muffle, 
when  It  takes  fire,  burns  with  a  faint  blue  flame,  and  sends  off  fumes  which  condense  into 
a  yellow  pulverulent  oxyde.  But  an  easier  process  than  that  now  mentioned  is  to 
dissolve  ttie  bismuth  m  nitric  acid,  precipitate  with  water,  and  expose  the  precipitate  to 
a  red  heat.  The  oxyde  thus  obtained  has  a  straw  yellow  color,  and  fuses  at  a  high 
heat  into  an  opaque  glass  of  a  dark-brown  or  black  color ;  but  which  becomes  1^ 
opaque  and  yellow  after  it  has  cooled.  Its  specific  gravity  is  so  high  as  8-211.  It  con- 
sists of  89-87  of  metal  and  10-13  oxygen  in  100  parts.  The  above  precipitate,  which 
IS  a  sub-nitrate  of  bismuth,  is  caUed  pearl-whiie,  and  is  employed  as  a  flux  for  certain 
enumels;  as  it  augments  their  fusibility  without  imparting  any  color  to  them.  Hence, 
It  is  used  sometmies  as  a  vehicle  of  the  colors  of  other  metallic  oxydes.  When  well 
Tft  r^  I  !t  e°^PJoyed  m  gildmg  porcelain ;  being  added  in  the  proportion  of  one 
fifteenth  to  the  gold  But  pearl-white  is  most  used  by  ladies  as  a  cosmetic  for  giving  a 
briUiant  tint  to  a  faded  complexion.     It  is  called  Wane  de  fard,  by  the  French.     If  it  con- 

S'l^'i,?  w,,  ?i^^"  ^T'  ^  ^""^  ^'^""^'^  '^  ^^^'"^s  ^^y  o^  dingy  colored  on  exposure 
to  light.  When  the  oxyde  is  prepared,  by  dropping  the  nitric  solution  into  an  alkaline 
ley  in  excess,  if  this  precipitate  is  well  washed  and  dried,  it  forms  an  excellent  medicine ; 
and  is  given,  mixed  with  gum  tragacanth,  for  the  relief  of  cardial-ia,  or  burning  and 
spasmodic  pains  of  the  stomach.  ^    '  *"5  ««* 

c,u  r\^>f ""  "^^  of  pearl-powder  is  prepared  by  adding  a  very  dilute  solution  of  common 
salt  to  the  above  nitric  solution  of  bismuth,  whereby  a  pulverulent  sub-chloride  of  the 
metal  is  obtained  m  a  light  flocculent  form.  A  similar  powder  of  a  mother-of-pearl 
aspect  may  be  formed  by  dropping  dilute  muriatic  acid  into  the  solution  of  nitrate  of 
bismuth.  The  arsenic  always  present  in  the  bismuth  of  commerce  is  converted  by  nitric 
acid  into  arsenic  acid  which,  forming  an  insoluble  arseniate  of  bismuth,  separates  from 
the  solution,  unless  there  be  such  an  excess  of  nitric  acid  as  to  re-dissolve  it.  Hence  the 
medicinal  oxyde,  prepared  from  a  rightly-made  nitrate,  can  contain  no  arsenic.  If  we 
write  with  a  pen  dipped  in  that  solution,  the  dry  invisible  traces  will  become  legible  on 
plunging  the  paper  m  water.  ^ 

It  has  been  proposed  to  substitute  bismuth  for  lead  in  assaying  silver,  as  a  smaUer 
quantity  of  it  answers  the  purpose,  and,  as  its  oxyde  is  more  fluent,  can  therefore 
penetrate  the  cupel  more  readily,  and  give  a  more  rapid  result.  But,  independently 
^  the  objection  from  its  high  price,  bismuth  has  the  disadvantage  of  boiling  up,  as 
wel  as  of  rocking  or  vegetatmg,  with  the  silver,  when  the  cupeUation  requires  a  hich 
heat.  In  extracting  the  silver  from  the  galena  found  in  the  copper-mine  of  Yahlun. 
It  has  happened  sometimes  that  the  sUver  concreted  towards  the  end  of  the  operation 
5nl  nfl^f  I  cauliflower  excrescence,  which  had  to  be  cupelled  again  with  a  fresh 
?hT .^Ll  p  r^'  ''}T^.  *>^^' '"  ^^'^  "^'"'  ^  P°''ti««  «f  the  silver  had  passed  into 
bismuth        ^'^"'^^'^'  ^^^^^^^^  ^"  ^  s^Ple  of  sUver  thus   concreted  the  presence  of 

The  nitrate  of  bismuth,  mixed  with  solution  of  tin  and  tartar,  has  been  employed  as  a 
mordant  for  dyeing  lilach  and  violet  in  calico  printing.  p    ycu  as  a 

in  fhf^f^;  J^^'Jrrw' '  .^^^'^%Ge™-)  A  brown  color  which  is  used  in  water  colors, 
frrred      tL  Z  f        "^  l"^'.  ?  ^^P^^P^^^  from  wood-soot,  that  of  beech  being  pre! 

S^v  nnlvTi-Lr'i/  P''?^^  ^f '  ^T"'^  P^'^^^^  «^  ««°t  "^  <^o"ected  from  the  chim- 
ney, pulver^ed,  and  passed  through  a  silk  sieve.     This  powder  is  infused  in  pure  water, 

ef  If  tt  lir:lJ  T' V  ^^T  r^''^  *^^"  ""«^^  ^«  ^^«1^'  ^hen  the  water  is  deS 
ThP  iLtp  if  nnw  ♦  X^  ^  "^^/-"^  ^"^^^^  '^^  P^«^^^«  °^^y  be  repeated  with  warm  water. 
y„H  [pft  tn  Mitw        e  P^".'"^^/"^^  ^  ^«J^g  ^^^^  vessel  filled  with  water,  stirred  weU, 
and  left  to  sett  e  for  a  few  minutes,  m  order  to  let  the  grosser  parts  subside     The  super 
natant  part  is  then  to  be  poured  ofi"  into  a  similar  vessel.    This  process  may  be  repeated 

fi^^nH  wh'n'r'p"??'"  ""r'  ^""^  ^'''''-  ^'  '^^*  '^^  settled  deposite  is  suffidenSy 
fntn  nrnnZ  .  w  ^omits  Supernatant  water,  it  is  mixed  with  gum-water,  moulded 
mto  proper  cakes,  and  diied.  It  is  not  used  in  oil  painting,  but  has  the  same  effect  in 
water-colors  as  brown  pmk  has  in  oil.  *-         o*  ^  a-mc  ^ucvi,  m 


I 


BITTER  PRINCIPLE  {Ain^re,  Fr. ;  Bittentoff,  Germ.)  This  principle  has  not 
been  insulated  hitherto  by  the  chemist  from  the  other  proximate  principles  of  plants, 
but  its  existence  is  suflSciently  recognized  by  the  taste.  The  following  list  contains 
the  principal  bitter  substances,  many  of  which  have  been  used  in  the  arts  and  in 
medicine.  • 


Nome. 


Quassia 

Wormwood 

Aloe 

Angustura 

Orange 

Ditto 

Acorus 

Carduus  Benedictus 

Cascarilla 

Centaury 

Camomile 

Colocynth 

Colombo 

Fumitory 

Gentiana  lutea 

Ground  Ivy 

Walnut 

Island  moss  * 

Hops 

Milfoil 

Large-leaved  Satyrion 

Rhubarb 

Rue 

Tansy 

Bitter  trefoil 

Simarouba 

Bryony 

Coffee 


Part  employed. 

Wood 

Herb 

Inspissated  juice 

Bark 

Unripe  Fruit 

Peel 

Root 

Herb 

Bark 

Herb 

Flowers 

Fruit 

Root 

Herb 

Root 

Herb 

Peels 


Country. 


Scales  of  the  fe- 
male flowers 
Herb  flowers 
Herb 
Root 
Herb 

Herb  flowers 
Herb 
Bark 

Root 

Seeds 


[ 


Surinam,  E.  Indies 

Great  Britain 

South  Africa 

South  America 

South  of  Europe   ) 

Ditto  J 

Ditto 

Greek  Archipelago 

Jamaica 

Great  Britain 

Levant 
East  Africa 
Great  Britain 
Switzerland 
Great  Britain 


Great  Britain 

Great  Britain 

Great  Britain 

China 

Great  Britain 

Ditto 

Ditto 

Guiana 


Observations. 


Great  Britain 
Arabia 


J 


Powerfully  bitter 

Ditto 

Ditto 

Ditto 

Aromatic  bitter 

Ditto 

Ditto 


Intolerably  bitter 
Very  bitter 

Very  bitter 

With  tannin 
With  starch 

Aromatic  bitters 


Disagreable  odor 
Bitter  and  sharp 
Bitter  and  offensive 


j  Sharp,  bitter,  nau 
\      seous 


BITUMEN,  or  ASPHALTUM.      {Bitume,  Fr. ;  Erdpech,    Germ.)      A  black   sub- 
stance found  m  the  earth,  externally  not  dissimilar  to  pit-coal.     It  is  composed  of 
carbon,  hydrogen,  and  oxygen,  like  organic  bodies;  but  its  origin  is  unknown.     It 
has  not  been  observed  among  the  primitive  or  older  strata,  but  only  in  the  secondary 
and  alluvial  formations.     It  constitutes  sometimes  considerable  beds,  as  in  the  Isle  of 
Trinidad,  where  it  occurs  over  an  extensive  district,  in  scattered  masses.     The  greater 
part  of  the  asphaltum  to  be  met  with  in  commerce  comes  from  the  Dead  Sea,  on  whose 
shores  It  18  cast  up  and  gathered ;  whence  it  has  got  the  name  of  Jewish  bitumen.    In 
Its  black  color  and  fracture  it  resembles  ordinary  pitch.     By  friction  it  affords  nega- 
tive electricity.     Its  average  density  is  MS.     It  melts  at  the  temperature  of  boiling 
water,  kindles  very  readily  at  the  flame,  burns  brightly  with  a  thick  smoke  and 
leaves  little  ashes.     Distilled  by  itself,  it  yields  a  peculiar  bituminous  oil,  very  little 
water,  some  combustible  gases,  and  traces  of  ammonia.     It  leaves  about  one-tliird  of 
Its  weight  of  charcoal  after  combustion,  and  ashes,  containing  silica,  alumina,  oxide  of 
iron,  sometimes  a  little  lime,  and  oxide  of  manganese.     According  to  John,  asphaltum 
may  be  decomposed,  by  different  solvents,  into  three  distinct  substances.    Water  dis- 
solves nothing ;  alcohol  (anhydrous)  dissolves  out  a  yellow  resin  equal  to  5  per  cent,  of 
the  weight  of  the  asphaltum ;  that  resin  is  soluble  in  dilute  alcohol  and  in  ether.    The 
portion  not  soluble  in  the  alcohol  gives  up  a  brown  resin  to  ether,  amounting  to  70  i^er 
cent  of  the  weight  of  the  asphaltum.     On  evaporating  off  the  ether,  the  resin  remains 
ot  a  brownish-black  colour,  which  dissolves  readily  in  the  volatile  oils  and  in  the  oil 
^  i^ti  ^-    ";    r^^  portion  of  asphaltum  which  does  not  dissolve  in  ether  is  very 
soluble  m  oil  of  turpentine,  and  in  oil  of  petroleum;  but  less  so  in  oil  of  lavender. 
Ihese  three  resinous  principles  dissolve  all  together  by  digestion  in  the  oils  of  anise, 
rosemary,  turpentine,  olive,  hemp-seed,  nut,  and  linseed.     Caustic  potash  dissolves  a 
notable  quantity  of  asphaltum ;  but  carbonate  of  potash  has  no  effect  upon  it 

Asphaltum  enters  into  the  composition  of  hydraulic  cements,  and  into  that  of  black 
varnishes  called  japans,  for  coating  iron  trays,  etc.  A  similar  varnish  may  be  pre- 
pared by  dissolving  12  parts  of  fused  amber,  2  parts  of  rosin,  and  2  parts  of  asphaltum, 
m  0  parts  of  Imseed  oil  varnish,  to  which  12  parts  of  oil  of  turpentine  have  been  added. 


174 


BITUMEN. 


Thei  e  is  a  kind  of  bitumen  found  at  Aniches,  in  France,  in  the  department  of  the 
Korth,  which  is  black,  very  fusible  aud  soft  It  burns  with  flame.  Alcohol,  ether,  and  oil 
of  turpentine  extract  from  it  a  fatty  substance,  which  may  be  saponified  with  alkalis, 
"^^e  bitumen  of  Murindo,  near  Choco,  in  Columbia,  is  of  a  brownish-black  color, 
sof^  and  has  an  earthy  fracture.  It  has  an  acrid  taste,  burns  with  a  smell  of  vanilla, 
and  is  said  to  contain  a  large  quantity  of  benzoic  acid.  It  appears  to  be  the  result  of 
the  decomposition  of  trees  containing  benzoin. 

Asphaltum  occurs  abundantly  at  the  surface  of  the  salt  lake  Asphaltites,  in  Judea, 
produced  from  springs  in  the  neighborhood ;  it  is  floated  down,  gathers  consistence, 
and  accumulates  upon  the  surface  of  the  lake ;  the  winds  drive  it  on  the  shores,  and 
the  inhabitants  collect  it  for  sale.  Its  inspissation  diff'uses  a  disagreable  smell  in  the 
air  of  that  region,  which  is  supposed  by  the  natives  to  be  powerful  enough  to  kill  birds 
■when  they  attempt  to  fly  across  the  lake. 

But  probaby  the  most  remarkable  locality  of  asphaltum  in  the  world  is  the  entire 
basin  or  rather  plain  of  it,  in  the  island  of  Trmidad,  called  the  Tar  Lake.  It  lies  on  the 
highest  land  in  the  island,  and  emits  a  strong  smell,  sensible  at  ten  miles'  distance.  Its 
first  appearance  is  that  of  a  lake  of  water,  but  when  viewed  more  nearly  it  seems  to  be 
a  surface  of  glass.  In  hot  weather  its  surface  liquifies  to  the  depth  of  an  inch,  and  it 
cannot  then  be  walked  upon.  It  is  of  a  circular  form,  about  three  miles  in  circumfe- 
rence, and  of  a  depth  not  ascertained.  Large  fissures  frequently  open  and  close  up  in 
it,  whence  the  pitch  has  been  supposed  to  float  upon  a  body  of  water.  The  soil  for  a 
considerable  distance  round  it,  consists  of  cinders  and  burnt  earth,  and  presents  in 
many  points  indications  of  convulsions  by  subterranean  fire.  In  several  parts  of  the 
neighboring  woods,  there  are  round  holes  and  fissures  in  the  ground,  containing  liquid 
bitumen  to  the  depth  of  two  inches. 

Mr.  Hatchett  examined  some  specimens  from  Trinidad,  and  concluded  that  what  had 
been  heretofore  supposed  to  be  a  pure  mineral  pitch  was  in  reality  only  a  porous  stone 
of  the  argillaceous  kind,  much  impregnated  with  bitumen. 

These  various  bitumens  belong  exclusively  to  the  secondary  and  tertiary  geol(^i- 
cal  formations,  and  are  not  found  among  primitive  rocks,  except  very  rarely  in  veins. 
They  occur  most  generally  in  calcareous,  argillaceous  and  ?andy  strata,  and  also  in 
volcanic  districts.  Petroleum  frequently  floats  on  the  waters  which  issue  from  the 
volcanic  mountains,  or  which  lie  at  their  base ;  even  the  sea  is  at  times  covered  with 
it  near  the  volcanic  islands  of  Cape  de  Verd.  Mr.  Breislack  observed  a  petroleum 
spring  rising  from  the  bottom  of  the  sea  near  the  south  base  of  Vesuvius. 

The  substance  with  which  bitumen  seems  to  have  the  most  constant  and  most  re- 
markable relations  is  sea-salt ;  so  that  almost  all  the  countries  most  abundant  in  pe- 
troleum, as  Italy,  Transylvania,  Persia,  the  environs  of  Babylon,  the  region  of  the 
Dead  Sea,  <fec.,  contain  salt  mines,  or  lakes,  or  exhibit  saline  efilorescences.  Iron  py- 
rites is  often  impregnated  with  petroleum,  or  contains  a  bituminous  nucleus. 

The  origin  of  bitumen  is  as  little  known  as  that  of  most  of  the  productions  of  nature. 
Some  regard  it  as  an  empyreumatic  oil,  a  matter  analogous  to  liquid  resin  or  essential 
oil,  resulting  from  the  destruction  of  that  astonishing  multitude  of  animals  and  vege- 
tables buried  in  the  earth,  whose  solid  remains  are  daily  brought  to  view  in  mineral 
researches.  It  has  been  also  supposed  that  naptha  and  petroleum  are  the  product  of 
coals  decomposed  either  by  the  fire  of  volcanoes,  by  the  subterranean  combustion  of 
coal  itself  or  by  the  decomposition  of  pyrites.  The  latter  opinion  is  not  supported 
by  any  direct  evidence,  but  the  two  former  are  sufficiently  probable. 

Elastic  Bitumen  is  a  rare  substance,  found  hitherto  only  near  Castleton,  in  Derby- 
Bhire,  in  fissures  of  slaty  clay. 

Bituminous  mastic,  or  cement,  has  been  of  late  extensively  employed  in  France  for 
covering  roofs  and  terraces,  and  lining  water-cisterns.  The  mineral  bitumen  used  for 
the  composition  of  this  mastic  is  procured  chiefly  from  the  Obsann  (Bas-Rhin),  from 
the  Pare  (department  de  I'Ain),  and  from  the  Puy-de-la-Poix  (department  of  Puy-de- 
Dome).  But  boiled  coal  tar  answers  pretty  well.  In  the  neighborhood  of  those 
localities,  there  is  a  limestone  impregnated  with  bitumen  which  suits  for  giving  con 
eistence  to  the  cement  This  is  well  dried,  ground  to  powder,  sifted,  and  stirred  while 
hot,  in  about  one  fifth  its  weight  of  melted  asphaltum,  contained  in  a  cast  iron  boiler. 
Dry  chalk  or  bricks,  ground  and  sifted,  will  suit  equally  well.  As  soon  as  this  paste  is 
made  quite  homogeneous,  it  is  lifted  out  with  an  iron  shovel  or  spoon,  and  spread  in 
rectangular  moulds,  secured  with  pegs  at  the  joints,  fastened  to  a  kind  of  platform  of 
smoothed  planks,  covered  with  strong  sheet-iron.  The  sides  of  these  moulds  should  be 
previously  smeared  over  with  a  thin  coat  of  loam-paste,  to  prevent  their  adhesion  to 
the  mastic.  Whenever  the  cake  is  cold,  the  frame  is  taken  asunder,  and  it  is  removed 
from  the  iron  plate  by  an  oblong  shovel,  or  strong  spatula  of  iron.  These  cakes  or 
bricks  are  usually  18  inches  long,  12  broad  and  4  thick,  and  weigh  about  70  lbs. 
It  is  a  very  remarkable  fact,  in  the  history  of  the  useful  arts,  that  asphalt,  which 


BITUMEN. 


175 


i 


\ 


was  so  generally  employed  as  a  solid  and  durable  cement  in  the  earliest  constructions 
upon  record,  as  m  the  walls  of  Babylon,  should  for  so  many  thousand  years  have 
lallen  well  nigh  into  disuse  among  civilized  nations.     For  there  is  certainly  no  class 
»f  mineral  substance  so  well  fitted  as  the  bituminous  by  their  plasticity,  fosibilitf 
enacity,  adhesiveness  to  surfaces,  impenetrability  by  water,  and  unchangeablenis 
to  the  atmosphere  te  enter  into  the  composition  of  terraces,  foot-pavements,  roof^ 
»nd  every  kind  of  hydraulic  work.     Bitumen,  combined  with  calcareous  earth  forrS 
^  compact,  semi-elastic  solid,  which  is  not  liable  to  suffer  injury  by  the  greatest  alteT 
r^rZl  ?/^''  ""V^^'  ^}'^'\  "''^^  disintegrate  in  a  fe^  yLiJthe  Srdest  ston^ 
anLT  ^T^^  \  "^"'^  ^""^  "^^"^  ""^^y  ^y  ^^^  attrition  of  the  feet  of  men  and 

animaH  as  sandstone,  flags,  and  even  blocks  of  granite  are.  An  asphalt  pavement 
nghtly  temperedm  tenacity,  solidity,  and  elasticity,  seems  t«  be  i^cZblf  ofsuffTrine 
abrasion  in  the  most  crowdfed  thoroughfares ;  a  fact  exemplified  of  late  in  a  few  Xef 

h2}^f^r  •  ^  ^^  la  Concorde  (formerly  Place  Louis  Quinze)  is  covered  with  a 
beautiful  mosaic  pavement  of  asphalt-  manv  of  tha  ^r^^rr.^r,^A  A.    t>     ,  ^""  * 

season,  most  unpropitious  to  the  laying  of  bituminous  m^tkl      R^l^ 

blK:ks  not  more  than  three  or  four  inches  tSTanr?fwi;ichcontat!Sl,l 

seem  to  have  a  propensity  to  decompose  by  the  joint  a^eScv  of  watJr  In/^       u  ^^^* 
mineral  pitch  has  been  known  to  remain  f^ ageTw  t^ouraltfraUoi  '  ^^'"^ 

^ZZ\t^:ZeTZ^.l:^^^^^^^^^  as  the  native 

rock,  of  which  thTrichest  and   most  P.tPn^V     '^  ^^' ^^^"  P'^'P^'^J'  ^^"^'l  asphaltic 
Val^-TraversX  the  a^nlr^^^  ""  unquestionably   that  of  the 

in  the  Jurassic  limestonr?ormLtYonf  thf  e^^^  mineral  deposite  occurs 

is  very  accessible,  and  may  be  S  ly  Lclvated  ^^^^^^  '^^'    P^  "^^^^ 

stone  is  massive,  of  irregular  fracture  orrilvirhrnLni^  "^'i^-  ^.""P^^^er.  The 
a  few  minute  spindes  of  calcareous  spar  Though  h^"*^?.'*  ^"^  "interspersed  with 
it  is  diflicult  to  break  by  the  hammer  Whin  .v?t  VT^  ^^  scratched  with  the  nail, 
hales  a  fragrant  ambrosiirsmeUra  pro^^^^^^^  it  ex! 

compounds  of  factitious  bitumpn      Tt«  crlJ-fi  ^  once  distinguishes  it  from  all 

being  nearly  thrStv  of  S^  uJ^^""  gravity  is  2-114,  water  being  1,000, 
it  in  succesJivrporSof  ho  o^^^^  most  conveniently  analyzed  bydige  ting 

pulverulent  carffirof  Hme  and  20  ^^^^^^^^^^  'in/?"'^nS  ^^  ?«««  of  a  whiti 

Val-de-Travers  seems  ther'Sret iT  rfche  \^^^^^^  °^ 

cording  to  the  statement  in  the  snecificatinn  nf  ri  -a  ,  *^  ®^  Pyrimont,  which,  ac 
contains  "carbonate  of  lime  and  SSn  ab^L  th^^^^^^  patent,  of  November,  1837, 
of  lime  to  about  10  parts  of  Wtumen  »  Proportion  of  90  parts  of  carbonate 

^^Z^^l^  "ifofTrtetrV^'  penetrated  with  the  bitumen, 
muriatic  acid;  a  circumstance  partTv  dueTftL  ♦  f7  ^t""^^^  ^^  ^^^'  ^"^  «^^«  ^f 
mineral,  but  chiefly  to  the  vast  Incumhpnt  11  ^""^^^  f '^"'^  *^^  ^«»«^"^e  ^^  the 
have  been  incorporated  in  ^he  boweS  n?  tiff ''!f!  "^ "/""  ^?^*^^  ^^«  ^^^  '"^terials 
matter  to  combine,  by  aA^cial  meThid.  .,i  ^'''^^'  V°"^^  '""^^^  ^^  «  ^^f^<^^^^ 
men,  and  for  this  reLon  thp  Lfc!-  ^  '  ^^"""^".^  earth  thus  intimately  with  bitu- 
perishable.  Many  of  he  factidous  t'n^u  "  '"  '^''  ^"^  ^'^  ^^"^^  *«  ^'^'^'^  ^ore 
of  siliceous  sand,  Lm  which  JhflT  ^^.u^  ^^°'^''^'  contain  a  considerable  quantiti 

when  trodden  upon       In  fact  tLre7eems^^h^^^^^^  ^^""^»>"'^  ^«^^ 

matter  and  bitumen,  that  their  nart^  IZ^L    r     '°  ^'^?^  attraction  between  siliceous 
tive  force.  ^^"^^  separate  from  each  other  by  a  very  small  disrup- 

Since  the  asphalt  rock  of  Val-de-Travers  is  naturally  rich  enough  in  concrete  bitu- 

•  See  the  conclusion  of  thl«  article. 


176 


BITUMEN. 


men,  it,  may  be  converted  into  a  plastic  workable  mastic  of  excellent  qualitjr  for  foot 
pavements  and  hydraulic  works  at  verv  little  expense,  merely  by  the  addition  of  a 
very  small  quantity  of  mineral  or  coal  tar,  amountmg  to  not  more  than  6  or  8  per 
cent  The  union  between  these  materials  may  be  eflfected  in  an  iron  cauldron,  by  the 
application  of  a  very  moderate  heat^  as  the  asphalt  bitumen  readily  coalesces  with 
the  tar  into  a  tenacious  solid.  i     m 

The  mode  adopted  for  making  the  beautiful  asphalt  pavement  at  the  Place  de  la 
Concorde  in  Paris  was  as  follows : — ^The  ground  was  made  uniformly  smooth,  either 
in  a  horizontal  plane  or  with  a  gentle  slope  to  carry  off  the  water;  the  curb-stones 
were  then  laid  round  the  margin  by  the  mason  about  4  inches  above  the  level  of  the 
ground.  This  hollow  space  was  filled  to  a  depth  of  3  inches  with  concrete,  containing 
about  a  sixth  part  of  hydraulic  lime,  well  pressed  upon  its  bed-  The  surface  waa 
next  smoothed  with  a  thin  coat  of  mortar.  When  the  whole  mass  had  become  per- 
fectly dry,  the  mosaic  pattern  was  set  out  on  the  surface,  the  moulds  being  formed 
of  flat  iron  bars,  rings,  <fec.  about  half  an  inch  thick,  into  which  the  fluid  mastic  was 
poured  by  ladles  from  a  cauldron,  and  spread  evenly  over. 

The  mastic  was  made  in  the  following  way: — ^The  asphalt  rock  was  first  of  all 
roasted  in  an  oven,  about  10  feet  long  and  3  broad  in  order  to  render  it  friable. 
The  bottom  of  the  oven  was  sheet  iron,  heated  below  by  a  brisk  fire.  A  volatile 
matter  exhaled,  probably  of  the  nature  of  naptha,  to  the  amount  of  one-fortieth  the 
weight  of  asphalt ;  after  roasting,  the  asphalt  became  so  friable,  as  to  be  easily  reduced 
to  powder,  and  passed  through  a  sieve,  having  meshes  about  one-fourth  of  an  inch  square. 

The  bitumen  destined  to  render  the  asphalt  fusible  and  plastic  was  melted  in  small 
quantities  at  a  time,  in  an  iron  cauldron,  and  then  the  asphalt  in  powder  was  gradually 
stirred  in  to  the  amount  of  12  or  13  times  the  weight  of  bitumen.  When  the  mix- 
ture became  fluid,  nearly  a  bucketful  of  very  small,  clean  gravel,  previously  heated 
apart,  was  stirred  into  it ;  and,  as  soon  as  the  whole  began  to  simmer  with  a  treacley 
consistence,  it  was  fit  for  use.    It  waa  transported  in  buckets,  and  poured  into  the 

For  the  reasons  above  assigned,  I  consider  this  addition  of  rounded,  polished,  siliceoua 
stones  to  be  very  injudicious.  If  anything  of  the  kind  be  wanted  to  give  solidity  to  the 
pavement,  it  should  be  a  granitic  or  hard  calcareous  sand,  whose  angular  form  will 
secure  the  cohesion  of  the  mass.  I  conceive,  also,  that  tar,  in  moderate  quantity, 
should  be  used  to  give  toughness  to  the  asphaltic  combination,  and  prevent  its  being 
pulverized  and  abraded  by  friction. 

In  the  able  report  of  the  Bastenne  and  Gaujac  Bitumen  company,  drawn  up  by 
Messrs.  Goldsmid  and  Russell,  these  gentlemen  have  made  an  interesting  comparison 
between  the  properties  of  mineral  tar  and  vegetable  tar  :  the  bitumen  composed  of  the 
latter  substance,  including  various  modifications,  extracted  from  coal  and  gas,  have,  so 
far  as  they  were  able  to  ascertain,  entirely  failed.  This  bitumen,  owing  to  the  quali- 
ties and  defects  of  vegetable  tar,  becomes  soft  at  115°  of  Fahrenheit's  scale,  and  is  brittle 
at  the  freezing  point ;  while  the  bitumen,  into  which  mineral  tar  enters,  will  sustain 
170°  of  heat,  without  injury.  In  the  course  of  the  winter,  1837-'38,  when  the  cold 
was  at  14|°  below  zero,  C,  the  bitumen  of  Bastenne  and  Gaujac,  with  which  one  side  of 
the  Pont  Neuf  at  Paris  is  paved,  was  not  at  all  impaired,  and  would,  apparently,  have 
resisted  any  decree  of  cold ;  while  that  in  some  parts  of  the  Boulevard,  which  was 
composed  of  vegetable  tar,  cracked  and  opened  in  white  fissures.  The  French  gov- 
ernment, instructed  by  these  experiments,  has  required,  when  any  of  the  vegetable 
bitumens  are  laid,  that  the  pavement  should  be  an  inch  and  a  quarter  thick ;  whereas, 
where  the  bitumen  composed  of  mineral  tar  is  used,  a  thickness  of  three  quarters  of 
an  inch  is  deemed  sufficient.  The  pavement  of  the  bonding  warehouse  at  Bordeaux 
has  been  laid  upward  of  15  years  by  the  Bastenne  company,  and  is  now  in  a  condition 
as  perfect  as  when  first  formed.  The  reservoirs  constructed  to  contain  the  waters  of 
the  Seine  at  Batisnolles,  near  Paris,  have  been  mounted  6  years,  and,  notwithstanding 
the  intense  cold  of  the  winter  of  1837,  which  froze  the  whole  of  their  contents  into  one 
solid  mass,  and  the  perpetual  water  pressure  to  which  they  are  exposed,  they  have  not 
betrayed  the  slij?htest  imperfection  in  any  point.  The  repairs  done  to  the  ancient  for- 
tifications at  Bayonne,  have  answered  so  well,  that  the  government,  2  years  ago, 
«*ntered  into  a  very  large  contract  with  the  company  for  additional  works,  while  the 
whole  of  the  arches  of  the  St.  Germain  and  St.  Cloud  railways,  and  the  pavements  and 
flooring's  necessary  for  these  works,  are  being  laid  with  the  Bastenne  bitumen. 

The'mineral  tar  in  the  mines  of  Bastenne  and  Gaujac  is  easily  separated  from  the 
earthy  matter  with  which  it  is  naturally  mixed  by  the  process  of  boiling,  and  is  then 
transported  in  barrels  to  Paris  or  London,  being  laid  down  in  the  latter  place  to  the 
company  at  17Z.  per  ton,  in  virtue  of  a  monopoly  of  the  article  purchased  by  the  com- 
pany at  a  sum,  it  is  said,  of  8,000/. 

Mr.  Harvey,  the  able  superintendent  of  the  Bastenne  company,  was  good  enough 
to  supply  me  with  various  samples  of  mineral  tar,  bitumen,  and  asphaltic  rock,  for 


> 


BITUMEN. 


177 


analysis.  The  tar  of  Bastenne  is  an  exceedingly  viscid  mass,  without  any  earthy  im- 
purity. It  has  the  consistence  of  bakers' dough  at  60°  of  Fahrenheit ;  at  80°  it  yieldti 
to  the  slightest  pressure  of  the  finger ;  at  150°  it  resembles  a  soft  extract ;  and  at  212*^ 
it  has  the  fluidity  of  molasses.  It  ia  admirably  adapted  to  give  plasticity  to  the  cal- 
careous asphalts.  ** 

A  specimen  of  Egyptian  asphalt  which  he  brought  me,  gave  by  analysis  the  very 
same  composition  as  the  Val  de  Travers,  namely,  80  per  cent  of  pure  carbonate  of 
lime,  and  20  of  bitumen.  A  specimen  to  mtistic,  prepared  in  France,  was  found  to 
consist,  in  100  parts,  of  29  of  bitumen,  52  of  carbonate  of  lime,  and  19  of  silicious  sand. 
A  portion  of  stone  called  the  natural  Bastenne  rock  afi'orded  me  80  parts  of  gritty 
silicious  matter  and  20  of  thick  tar.  The  Trinidad  bitumen  contains  a  consideraWa 
portion  of  foreign  earthy  matter ;  one  specimen  yielded  me  26  per  cent  of  silicious 
sand ;  a  second,  28 ;  a  third,  20  ;  and  a  fourth,  30  :  the  remainder  was  pure  pitch.  One 
specimen  of  Egyptian  bitumen,  specific  gravity  1-2,  was  found  to  be  perfectly  pure; 
for  it  dissolved  in  oil  of  turpentine  without  leaving  any  appreciable  residuum. 

Robinson's  Parisian  Bitumen  company  use  a  mastich  made  with  the  pitch  obtaineil 
from  boiling  coal-tar  mixed  with  chalk.  One  piece  laid  down.by  this  company  at 
Knightsbridgc  and  another  at  Brighton,  are  said  to  T.uve  gone  to  pieces.  The  portion  of 
pavement  laid  down  by  them  in  Oxford  street,  next  Charles  street,  has  been  taken  np. 
Claridge's  company  have  laid  down  their  mastich  under  the  archway  of  the  Horse- 
Guards,  and  in  the  carriage-entrance  at  the  Ordnance  Office ;  the  latter  has  cracked  at 
the  junction  with  the  old  pavement  of  Yorkshire  curb-stone.  The  foot-pavement  laid 
down  by  Claridge's  company  at  Whitehall  has  stood  well.  The  Bastenne  company 
has  exhibited  the  best  specimen  of  asphalt  pavement  in  Oxford  street ;  they  have  laid 
down  an  excellent  piece  of  foot-pavement  near  Northumberland  House ;  a  piece,  40 
feet  by  7,  on  Blackfriars'  Bridge ;  they  have  made  a  substantial  job  in  paving  830 
superficial  feet  in  front  of  the  guard-room  at  Woolwich,  which,  though  much  traversed 
by  foot-passengers,  and  beat  by  the  guard  in  grounding  arms,  remains  sound ;  lastly, 
the  floor  of  the  stalls  belonging  to  the  cavalry  barracks  of  the  Blues  at  Knightsbridgc, 
is  probably  the  best  example  of  asphaltic  pavement  laid  down  in  this  country,  as  it  has 
received  no  injury  from  the  beating  of  the  horses'  feet. 

A.S  the  specific  gravity  of  properly-made  mastich  is  nearly  double  that  of  water,  a 
cubic  foot  of  it  will  weigh  from  125  to  130  lbs. ;  and  a  square  foot,  three  quarters  of 
an  inch  thick,  will  weigh  very  nearly  eight  pounds.  A  ton  of  it  will  therefore  cover 
280  square  feet.  The  prices  at  which  the  Bastenne  Bitumen  company  sell  their  prod- 
ucts is  as  follows  : — 

Pure  Mineral  tar,  241.  per  ton,  or  28^.  per  r,wt. 
Mastich  8/.  8s.  per  ton,  or  lOs.  per  cwt. 

Side  Pavement. 


From    50  to  100  feet.  Is.  3d.  per  foot. 


100 

250 

1*.  Id. 

250 

500 

Ud. 

500 

750 

lOd. 

750 

1000 

9d. 

1000 

2000 

Sd. 

2000 

5000 

Id. 

*\ 


Roofs  and  Terraces. 

Is.  6d.  per  foot. 
1*.  4d. 
Is.  Id, 
Is.  Od. 

Ud. 

lOd. 
9d. 

Where  the  work  exceeds  5,000  feet,  contracts  may  be  entered  into. 
For  filling  up  joints  of  brickwork,  &c.,  from  Id.  to  l^d.  per  foot,  run  accordini?  tc 
quantity.  ^^ 

These  prices  are  calculated  for  half  an  inch  thickness,  at  which  rate  a  ton  wiU  cove* 
420  square  feet. 

T  ^  ^^le  Val-de-Travers  company  engage  to  lay  down  their  rich  asphaltic  rock  in 
London  at  5/.  per  ton;  and  as  the  mineral  tar  equal  to  that  of  Seissel  may  probably  be 
had  m  England  at  one  fourth  the  price  of  that  foreign  article,  they  may  aff^ord  to  lay 
their  mastich  three  quarters  of  an  inch  thick  per  the  thousand  feet,  including  a  sub- 
stratum of  concrete,  at  a  rate  of  fivepence  per  square  foot,  instead  of  fifteenpence,  being 
the  rate  charged  under  that  condition  by  the  Bastenne  company. 
These  charges  are  for  London  and  its  immediate  vicinity. 

Report  of  the  experimental  Pavements  laid  down  in  Oxford  street,  from  Charles  street  to 

Tottenham  Court  Road,  January,  1839. 

1.  Robinson's  Parisian  bitumen,  laid  in  blocks  12  inches  square  and  5  inches  deen- 

he  substance  is  a  compound  of  bitumen,  lime,  &c.,  and  five  granite  stones  are  inserted 

hnt  kI  ^P        -^i  ^^°'^'  -^^  T^^  *'  ^*^^  ^"  «^^«ig^^  ^o"rses»  the  joints  cemented  with 

W  rS"- .  T^o   ^"^''^'^y  ^^  '^''  ^  ^^  «^"*'«  y^«i«'  '^^  l^^&th  is  20  feet,  SdTe 
pnce,  if  adopted,  9s.  per  square  yard.  »  »  ,  '"m  uie 

len^h\"'2o''fee't.^"^  ^^^  '°""^'  ^^^  diagonaUy.     The  quantity  is  97  square  yard,.,  the 


178 


BLACK  DYE. 


iM 


f    I 


3.  Granite  paving,  9  inches  deep,  joined  with  Clarige's  asphalt,  the  work  laid  ia 
straight  courses.  The  cost  to  the  parish  has  been  11 «.  7  <i  per  yard  superficial  for  the 
Jtone  and  laying,  Ac,  no  charge  being  made  by  Claridge's  Company  fur  the  asphalt 
The  quantity  is  240  yards,  the  length  64  feet 

4.  Granite  paving,  4i  inches  deep,  jointed  with  Claridge's  asphalt^  the  work  laid  in 
diagonal  coursee.  Cost  to  the  parish  9s.  6d.  per  square  yard.  No  charge  made  for 
the  asphalt     The  quantity  is  88  square  yards,  the  length  '?0  feet 

6.  The  Bastenne  Bitumen  Company.  The  blocks  are  12  inches  long.  6i  wide,  and 
3|  deep  with  bevelled  jointv^  close  at  bottom,  and  i  inch  open  at  top;  the  j'ointa 
cemented  with  hot  bitumen ;  the  substance  is  bituminous,  with  a  very  large  propor- 
tion of  granite  imbedded  in  each  block;  the  price,  if  adopted,  13«,  6d.  per  square 
yard;  the  length  m  straight  courses,  20  feet 

6.  Same  as  5,  but  the  courses  laid  diagonally.  The  length  40  feet ;  the  total  quan- 
nty  m  6  and  6  is  274  square  yards. 

7.  Aberdeen  granite  paving,  9  inches  deep;  laid  on  a  concrete  bottom,  fonned  of 
gravel  and  lime  the  joints  of  the  pavement  run  with  hot  lime  grout,  in  straight  courses. 
The  length  is  69  feet;  cost,  16*.  5d.  per  square  yard. 

8.  Same  as  7,  but  the  courses  laid  diagonally ;  length  38  feet. 

9.  Aberdeen  granite  paving,  9  inches  deep,  in  straight  courses,  without  a  concrete 

,n"'4^i?'''?^^  ^M  V^.  ^""^  ^'^""^^'^  ^*^«*'  ^2*-  ^-  per  yard ;  len-th,  24  feet. 

10.  Ihe  Scotch  Asphaltum  company.  The  work  is  laid  in  blocks  of  divers  lenjrth, 
9  inches  wide,  and  6^  deep;  the  side  joints  are  straight,  the  end  joints  are  bevelled 
alternately.  The  work  is  laid  in  straight  courses,  and  jointed  in  Roman  cement;  the 
jubstance  is,  apparently,  a  bituminous  matter  mixed  with  fine  gravel.     The  len-th  is 

11    Uv       number  of  square  yards,  210;  the  price,  per  yard,  il' adopted,  135.  6d. 

11.  Ihe  wood-pavmg.  The  blocks  are  sexagon  on  the  plan,  and  (with  the  excep- 
Uon  of  a  few  courses  that  are  only  8  inches),  12  inches  deep.  The  work  is  laid  end- 
wise  of  the  gram;  the  blocks  are  mostly  8  inches  diameter— a  few  courses  are  7 
inches.  The  material  is  Norway  fir;  there  is  no  prepared  bottom— the  blocks  are 
laid  on  the  plain  ground,  a  small  layer  of  gravel  being  spread  to  bed  them  in.  From 
the  west  end,  22  rows  of  courses  of  blocks  are  of  wood  in  its  .natural  state;  31  rows 
have  been  Kyanised ;  9  rows  at  the  eastern  end  have  been  dipped  in  Claridge's  as- 
phalt;  6  rows  have  been  dipped  in  a  solution  prepared  by  the  patentee ;  the  remain- 
der are  of  wood  m  the  natural  state.  The  length  of  this  piece  is  60  feet :  the  number 
of  yards,  230;  price  per  yard,  if  approved,  10«.  6d. 

12.  Val^e-Travers  company.  Blocks  in  straight  courses,  12  inches  square,  5  inches 
deep,  with  square  jomts.  The  substance  of  the  blocks  is  bituminous,  with  a  ven-  lar^'e 
proportion  of  granite  imbedded  in  each  block,  the  joints  cemented  with  hot  bitumen. 
l^tousT°      "  number  of  square  yards  94;  the  work  is  performed  gra- 

13.  The  same  company.  A  layer  of  clean  chippings  and  hot  asphalt  poured  thereon. 
Ihe  lace  up,  with  hot  asphalt  and  broken  stone  imbedded  therem.  The  length  is  25 
feet :  number  of  yards,  94 ;  the  work  is  gratuitous. 

14.  Same  as  9.     The  length  47  feet. 

By  order  of  the  Committee, 

H.  Kensett,  Chairman. 

Statement  of  the  number  of  carriages  passing  through  Oxford  street  at  the  undernamed 

times  and  places. 


Date. 
1839. 


Jan. 10 
18. 
22. 
S6. 
26. 


Time. 


6  in  the  morning  till  12  at 
do.  [night. 

do. 

do.     [morning. 
12  at  night  till  6  in  the 


Place. 


4> 


C4 


C 

O 


by  the  Pantheon.  347 
by  Stratford  place.  254 
by  Newman  street,  j  339 
by  Stratford  place  J  371 
do.  I  — 


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The  asphalt  pavements  were,  in  my  judgment,  so  imperfectly  constructed  with  coal 
tar,  ill  boiled  and  aqueous,  as  to  have  a  crumbling  property  when  exposed  to  vicissi- 
tudes of  weather.     Jiative  bitumen  makes  a  far  better  and  more  durable  cement 

BLACK  DYE.  {Teinte  noire,  Fr. ;  Schwartze  farbe.  Germ.)  For  1  cwt  of  cloth 
there  are  put  into  a  boiler  of  middle  size  ISlbs.  of  logwood  with  as  much  Aleppo  galls 
m  powder,  and  the  whole,  being  enclosed  in  a  bag,  is  boiled  in  a  suflScient  quantity  of 
water  for  12  hours.    One-third  of  this  bath  is  transferred  into  another  boUer  with  two 


BLACK  DYE. 


179 


pounds  of  verdigris ;  and  the  stuff  is  passed  through  this  solution,  stirring  it  continu- 
ally during  two  hours,  taking  care  to  keep  the  bath  very  hot  without  boiling.  The 
stuff  is  then  lifted  out,  another  third  of  the  bath  is  added  to  the  boiler,  along  with  8 
pounds  of  sulphate  of  iron  or  green  vitriol  The  fire  is  to  be  lowered  while  the  sul- 
phate dissolves,  and  the  bath  is  allowed  to  cool  for  half  an  hour,  after  which  the  stuff 
18  introduced,  and  well  moved  about  for  an  hour,  and  then  it  is  taken  out  to  air.  Lastly, 
the  remaining  third  of  the  bath  is  added  to  the  other  two,  taking  eare  to  squeeze  the 
bag  well.  18  or  22  lbs.  of  sumach  are  thrown  in ;  the  whole  is  just  brought  to  a  boil, 
and  then  refreshed  with  a  little  cold  water ;  2  pounds  more  of  sulphate  of  iron  are 
added,  after  which  the  stuff  is  turned  through  for  an  hour.  It  is  next  washed,  aired, 
and  put  again  into  the  bath,  stirring  it  continually  for  an  hour.  After  this,  it  is  car- 
ried to  the  river,  washed  well,  and  then  fulled.  Whenever  the  water  runs  off"  clear,  a 
bath  is  prepared  with  weld,  which  is  made  to  boil  for  an  instant ;  and  after  refreshing 
the  bath  the  stuff  is  turned  in  to  soften,  and  to  render  the  black  more  fast  In  this 
manner,  a  very  beautiful  black  is  obtained  without  rendering  the  cloth  too  harsh. 

Commonly  more  simple  processes  are  employed.  Thus  the  blue  cloth  is  simply 
turned  through  a  bath  of  gall-nuts,  where  it  is  boiled  for  two  hours.  It  is  next 
passed  through  a  bath  of  logwood  and  sulphate  of  iron  for  two  hours,  without  boil- 
ing, after  which  it  is  washed  and  fulled.  But  in  all  cases  the  cloth,  after  passing 
through  the  blue  vat,  should  be  thoroughly  washed,  because  the  least  remains  of  its 
alkalinity  would  injure  the  tone  to  be  given  in  the  black  copper. 

Hellot  has  found  that  the  dyeing  might  be  performed  in  the  following  manner: — 
For  20  yards  of  dark  blue  cloth,  a  bath  is  made  of  2  lbs,  of  fustic  {morm  tinctoria), 
4i  lbs.  logwood,  and  11  lbs  of  sumach.  After  boiling  the  cloth  in  it  for  three  hours 
it  is  lifted  out,  11  lbs.  of  sulphate  of  iron  are  thrown  into  the  boiler,  and  the  cloth  is 
then  passed  through  it  during  two  hours.  It  is  ..ow  aired,  and  put  again  in  the  bath 
for  an  hour.  It  is,  lastly,  washed  and  scoured.  The  black  is  less  velvety  than  that  by 
the  preceding  process.  Experience  convinced  him  that  the  maddering  prescribed  in 
the  ancient  regulations  only  gives  a  reddish  cast  to  the  black,  which  is  obtained  finer 
and  more  velvety  without  madder. 

A  black  may  be  dyed  likewise  without  having  given  a  blue  ground.  This  method 
is  emplojred  for  cloths  of  little  value.  In  this  case  they  are  rooted ;  that  is  to  say, 
they  receive  a  dun  ground  with  walnut  husks,  or  the  root  of  the  walnut  tree,  and 
are  afterward  ^  made  black  in  the  manner  above  described,  or  in  some  other  way ;  for 
it  is  obvious  that  a  black  may  be  obtained  by  several  processes. 

According  to  Lewis,  the  proportions  which  the  English  dyers  most  generally  adopt 
are.  for  112  lbs.  of  woollen  cloth  previously  dyed  of  a  dark  blue,  about  5  lbs.  of  sulphate 
of  iroii^  as  much  gall-nuts,  and  30  lbs.  of'^logwood.  They  begin  by  galling  the  cloth, 
they  then  pass  it  through  the  decoction  of  logwood,  to  which  the  sulphate  of  iron  has 
been  added. 

When  the  cloth  is  completely  dyed,  it  is  washed  in  the  river,  and  passed  through 
the  fulhng-raill  till  the  water  runs  off  clear  and  colorless.  Some  persons  recommend, 
for  fine  cloths,  to  full  them  with  soap  water.  This  operation  requires  an  expert  work- 
man, who  can  free  the  cloth  thoroughly  from  the  soap.  Several  recommend  at  its 
coming  from  the  fulling  to  pass  the  cloth  through  a  bath  of  weld,  with  the  view  of 
giving  softness  and  solidity  to  the  black.  Lewis  says,  that  passing  the  cloth  through 
weld^aft«r  it  has  been  treated  with  soap,  is  absolutely  useless,  although  it  may  be 
benefacial  when  this  operation  has  been  neglected. 

^  The  following  German  process  is  cheap  and  good.  100  lbs  of  cloth  or  wool  are  put 
into  the  copper  with  sufficient  water  and  15  lbs.  ot  Salzburg  vitriol  (potash-sulphate  of 
iron)  and  5  Ihs  of  argol,  heating  the  bath  gradually  to  boiling,  while  the  goods  are 
well  worked  about  for  two  hours,  taking  them  out,  and  laying  them  in  a  cool  place 
for  twenty-four  hours.  They  are  then  to  be  put  in  a  lukewarm  bath  of  from  25  lbs.  to 
30168.  of  logwood,  and  10  lbs.  of  fustic,  and  to  be  worked  therein  while  it  is  made  to 
boil  during  two  liouis.  The  goods  are  now  removed,  and  there  is  put  into  the  copper 
i\i  ^V'"^^  ^^r^  4'^^^^^^^  *"  vinegar;  the  goods  are  restored  iuto  the  improved 
batli,  and  turned  in  it  for  half  an  hour,  after  which  they  are  rinsed  and  dried. 

1  he  process  for  dyeing  merinos  black  is  for  100  lbs.  of  them  to  put  10  lbs.  of  copperas 
into  the  bath  of  pure  water,  and  to  work  therein  for  a  quarter  of  an  hour,  as  soon  as 
It  13  tepid  one-third  of  the  goods;  then  to  replace  that  portion  by  the  second,  and 
tiiler  another  quarter  of  an  hour,  to  put  in  the  last  third.  Each  portion  is  to  be  laid 
aside  tj)  air  in  the  cold.  The  bath  being  next  heated  to  140°  F.,  the  merinos  are  to  be 
treated  as  above  piecemeal ;  but  the  third  time  it  is  to  be  passed  through  the  bath  at 
a  boiling  heat  Being  now  well  mordanted,  the  goods  are  laid  aside  to  air  till  the 
loiiowing  day.  Ihe  copper  being  charged  with  water,  60  lbs.  of  ground  logwood  and 
j  iiw.  of  argol,  and  heated,  the  goods  are  to  be  passed  through  while  boiling  for  half 
an  hour.     They  are  then  rinsed.  s  »" 


»    -( 


^^ 


180 


BLACK  DYE. 


'    \  I 


J^  tin?fet-aZ.^  ir^  '°  "■"=  f  ""-f  ?he  ^ghT'ir  .he  silk  arc 

less  of  the  whi  e  gXuteo  X^,^  - '"^^''""""■5°^      •■"^"^  *""  ^'"""'  "'"''  ""'"  " 
are  used.    The  p?^?S  eommJnly  emXreS""a,'p»  '"1  ^^'°"'  "=^7  "^  "'"''«  ^'Ib. 

of  the  astringent  princ^  e  but  air^otX  onhT  f  ''"^'"'  ?<;'  ™'^  '■™'»  ">«  '^''3^' 
ly  fix  themselves  in  proportion  ?o  the  nua^^^itv  1^  ,1  "'T?*  Policies,  which  subsequent- 
tered  into  combination.  Conseque„urtKDrLe«Jc  "stringent  principle  which  had  en- 
of  weight  which  it  is  wished  toToSnicale  ?n  .h»  Mb  """^  •""■''iin?  lo  the  degree 
fflustration.  communicate  to  the  silk ;  a  circumstance  requiring  Mme 

The  commerce  of  silk  goods  ii  orrie.)  ««  .-.  . 
weight,  or  by  the  surface,  thM  if  by  measure  tZ  T^'V  f^^'.^  '"'''  ""•"  ^^  "•« 
distinguished  from  that  of  Lyons  the  sUks  „f  th  J  f^rn^J^  k"''*  "L^""'  '^^  •"o™"'^ 
the  latter,  by  measure.  It  was  ther/fifr.  .1  •  •  .  "  ''*'"S  '"'''  '>>'  ^cigl".  "><««  of 
and,  on  the  contrary'to  be  sTarin.  of  Z  ^V'  '"  "'^' '»  s"charge  the  weight  at  Tours, 
d«.inction  of  light  Wack  and  healytkckTt^„;"??r!t"^  ^.T'?"  ""="«  °™«"'« 
■^sflk  10^'°"'  '1"  '7  -"i-  »'-'ctvingtSnX.e"d  Jh^'''^'  °""'''"»"  "'  ^^ 

rbLi-rd^d-uA^^iS-i^^^^^^ 

black,  because  it  is  pretS  thlt  it  waT'first  orac-'Ju^^^^^^^  T  ^^»«°^i'^«ted  En.^ish 

a  great  surcharge  has  not  a  beSul  biLk  l^.?  n""/"?**?^'  ^^"*^«  ^^'^  dyed  with 
With  a  warp  dyld  of  a  fine  bJack  '         usually  destined  for  weft,  and  is  blended 

^^"^^^^^^^^^  consists  in  leaving  the 

ber  of  times  throu|h  the  dye,  anS  even  let tinl  ft^il  f^  >  T''"^  *^^  '^  *  greater  num- 
ing  is  usually  made  with  gaUs  which  have  irvJir  '^  ^""^  '°?^  *"""*  '^^«  ^'-^t  ?«»- 
gaU-nuts  are  employed  for  the  s^cind     R?,t  ?i  \^  Preceding  operation,  and  fresh 

giving  a  great  surcLge^sucras  °s  foun^/n  wW  ^''^i?^'  Tt^  ""'  ^'  '^^^'^^^^  <*«r 
it  this  weight,  the  silk  is  caUed  wfth on*  k^     ^*  '^  ''^"^  ^^^  ^"^^'^^  "ack.     To  give 

^T^  ^rr-l^  supiletti^rrked'^;  tre^T:'n^  pt'  ^"^  ^^'"^'^^  «"^  °^  ^« 
J  ^^et^^S^^^^^^^^^^  varies  in  di.erent 

^c^srii^i^Xi?^^^:^^ 

time  nothing  remains  of  the  sever  Jin^r^lntlw^^  T'  '^  '^^\  ^^  ^^^  ^""^  «^  »  <=ertain 
which  are  not  employed  in  theTrevet  ^""^  composed  the  primitive  bath,  but 

yellow  color,  is  made  choice  of.    U  should  be  rp^u^^''  ?"'P^'^'  ''^^>  ^^  ^^^  "^t^ve 
preserve  a  portion  of  the  gum  of  the  silk  wbJ^h  r'T^^^>J»^a'  when  it  is  desired  to 

w&:^x-5k!^£l-££^^^^^^^^^ 

U  made  in  the  cold,    ihhe  '^^^TX  ^^^^  Slk^Kli  Z  !^ 

n.«ie  in  the  cold ;  but,  aLrding  to  thTL^ier  !?'  i"  '"^"'"l '»  ^ive  it.  The  dye  fa 
Quires  more  or  less  time.  OccafionaDy  th^'e  "  foiilaf  ™^"'  "^  '"'  ™'''"?^' ''  ''■ 
It  B  washed,  it  fa  beetled  once  or  twice  aid  itT,  .K»  ^^  ««  n^essary;  after  which 
toflening  it  *•  ""''  "  «  «*"  ^'ed  without  wringing,  to  avoid 


BLACK  DYE. 


181 


Raw  Bilk  may  be  more  quickly  dyed,  by  shaking  it  round  the  rods  in  the  cold  bath 
after  the  galling,  airing  it,  and  repeating  these  manipulations  several  times,  after 
which  it  is  washed  and  dried  as  above. 

Macquer  describes  a  more  simple  process  for  the  black  by  which  velvet  is  dyed  at 
Genoa ;  and  he  says  that  this  process,  rendered  still  simpler,  has  had  complete  success 
at  Tours.     The  following  is  his  description. 

For  1  cwt  (50  kilogrammes)  silk,  22  lbs.  (11  kilogrammes)  of  Aleppo  galls,  in  powder, 
arc  boiled  for  an  hour  in  a  sufficient  quantity  of  water.  The  bath  is  allowed  to  settle  till 
tlie  galls  have  fallen  to  the  bottom  of  the  boiler,  from  which  they  are  withdrawn  ;  after 
which  32  lbs.  of  English  vitriol  (or  copperas)  are  introduced,  with  13  lbs.  of  iron-filinga, 
and  22  lbs  of  country  gum,  put  into  a  kind  of  two-handled  cullender,  pierced  every 
where  with  holes.  This  kettle  is  suspended  by  two  rods  in  the  boiler,  so  as  not  to 
reach  the  bottom.  The  gum  is  left  to  dissolve  for  about  an  hour,  stirring  it  from  time 
to  time.  I^  after  this  time,  some  gum  remains  in  the  kettle,  it  is  a  proof  that  the  bath, 
which  contains  two  hogsheads,  has  taken  as  much  of  it  as  is  necessary.  If,  on  the  con- 
trary, the  whole  gum  is  dissolved,  from  1  to  4  lbs.  more  may  be  added.  This  cullen- 
der 18  left  constantly  suspended  in  the  boiler,  from  which  it  is  removed  only  when  the 
dyeing  is  going  on ;  and  afterwards  it  is  replaced.  During  all  these  operations  the  boiler 
must  be  kept  hot,  but  without  boiling.  The  galling  of  the  silk  is  performed  with  one 
third  of  Aleppo  galls.  The  silk  is  left  in  it  for  six  hours  the  first  time,  then  for  twelve 
hours.    The  rest,  secundum  ariem, 

Lewis  states  that  he  has  repeated  this  process  in  the  small  way  ;  and  that  by  adding 
sulphate  of  iron  progressively,  and  repeating  the  immersions  of  the  silk  a  great  number 
of  times,  he  eventually  obtained  a  fine  black. 

Astringents  differ  from  one  another  as  to  the  quantity  of  the  principle  which  enters  into 
combination  with  the  oxyde  of  iron.  Hence,  the  proportion  of  the  sulphate,  or  of  any 
other  salt  of  iron,  and  that  of  the  astringents,  should  vary  according  to  the  astringents 
made  use  of,  and  according  to  their  respective  quantities.  Gall-nut  is  the  substance 
which  contains  most  astringent ;  sumach,  which  seems  second  to  it  in  this  respect,  throws 
down  (decomposes),  however,  only  half  as  much  sulphate  of  iron. 

The  most  suitable  proportion  of  sulphate  of  iron  appears  to  be  that  which  corresponds 
to  the  quantity  of  the  astringent  matter,  so  that  the  whole  iron  precipitable  by  the  as- 
tringent may  be  thrown  down,  and  the  whole  astringent  may  be  taken  up  in  combination 
with  the  iron.  As  it  is  not  possible,  however,  to  arrive  at  such  precision,  it  is  better 
that  the  sulphate  of  iron  should  predominate,  because  the  astringent,  when  in  excess, 
counteracts  the  precipitation  of  the  black  coloring  particles,  and  has  the  property  of  even 
dissolving  them. 

This  action  of  the  astringent  is  such  that,  if  a  pattern  of  black  cloth  be  boiled  with  gall- 
nuts,  it  IS  reducible  to  gray.  An  observation  of  Lewis  mav  thence  be  explained.  If  cloth 
be  turned  several  times  through  the  coloring  bath,  after  it' has  taken  a  good  black  color, 
instead  of  acquiring  more  body,  it  is  weakened,  and  becomes  brownish.  Too  considera- 
ble a  quantity  of  the  ingredients  produces  the  same  effect ;  to  which  the  sulphuric  acid 
set  at  liberty  by  the  precipitation  of  the  oxyde  of  iron,  contributes.  ' 

It  is  merely  the  highly  oxydized  sulphate  which  is  decomposed  by  the  astrin^^ent  • 
whence  it  appears,  that  the  sulphate  will  produce  a  different  effect  according  to  its  state 
of  oxydizemenl,  and  call  for  other  proportions.  Some  advise,  therefore,  to  follow  the 
method  of  Proust,  employing  it  in  the  oxydized  state ;  but  in  this  case  it  is  only  partially 
decomposed,  and  another  part  is  brought,  by  the  action  of  the  astringent,  into  the  lower 
aea:ree  of  oxydizement. 

The  particles  precipitated  by  the  mixture  of  an  astringent  and  sulphate  of  iron  have 
not  at  first  a  deep  color;  but  they  pass  to  a  black  by  contact  of  air  while  they  are 
moist.  '' 

Under  dyeing  I  shall  show  that  the  black  dye  is  only  a  very  condensed  color,  and  that 
It  assumes  more  intensity  from  the  mixture  of  different  colors  likewise  deep.  It  is  for 
this  reason  advantageous  to  unite  several  astringents,  each  combination  of  which  produ- 
ces  a  different  shade.  But  blue  appears  the  color  most  conducive  to  this  effect,  and  it 
corrects  the  tendency  to  dun,  which  is  remarked  in  the  black  produced  on  stufls  by  the 
other  astringents.  •' 

«.J?,'!rl^'*  P'-operty  is  founded  the  practice  of  giving  a  blue  ground  to  black  cloths,  which 
acquire  more  beauty  and  solidity  the  deeper  the  blue.  Another  advantage  of  this  prac- 
nrl-^-f°r  ""^  r^t  ^  u^  '•y^^'^'^y  ""^  sulphuric  acid  which  is  necessarily  disengaged  by  the 
hm  Z.ViT  1  ^  ^^,'^  particles  and  which  would  not  only  counteract  their  fixation, 
but  would  further  weaken  the  stuff,  and  give  it  harshness. 
^1- or^comraon  stuffs,  a  portion  of  the  effect  of  the  blue  ground  is  produced  by  the 

iw'fi'lti"'**^"''^  °T*  ^°»^<^  ^it^  astringents  contributes  to  the  beauty  of  the  black  in  a 
iwoiold   way.    It  produces  molecules  of  a  hue  diflferent  from  what  the  astringents  do, 


ii 


182 


BLACK  PIGMENT. 


BLACK  PIGMENT. 


183 


and  particularly  blue  molecules,  with  the  oxide  of  copper,  commonly  employed  in  the 
black  dyes ;  which  appears  to  be  more  useful  the  more  acetate  the  verdigris  made  use 
of  contains. 

The  boil  of  weld,  by  which  the  dye  of  black  cloth  is  frequently  finished,  may  also 
contribute  to  its  beauty,  by  the  shade  peculiar  to  its  combination.  It  has,  moreover, 
the  advantage  of  giving  softness  to  the  stuffs. 

The  processes  that  are  emplojed  for  wool  yield,  according  to  the  observation  o/ 
Lewis,  only  a  rusty  black  to  silk ;  and  cotton  is  hardly  dyed  by  the  process  propei 
for  wool  and  silk.  Let  us  endeavor  to  ascertain  the  conditions  which  these  three  varie- 
ties of  dyeing  demand. 

Wool  has  a  great  tendency  to  combine  with  coloring  substances ;  but  its  physical 
nature  requires  its  combinations  to  be  made  in  general  at  a  high  temperature.  The 
combination  of  the  black  molecules  may  therefore  be  directly  effected  in  a  bath,  in 
proportion  as  they  form ;  and  if  the  operation  be  prolonged  by  subdividing  it,  it  is 
only  with  the  view  of  changing  the  necessary  oxidizement  of  the  sulphate,  and  aug- 
menting that  of  the  coloring  particles  themselves. 

Silk  has  little  disposition  to  unite  with  the  black  particles.  It  seems  to  be  merely  by 
the  agency  of  the  tannin,  with  which  it  is  previously  impregnated,  that  these  particles 
can  fix  themselves  on  it,  especially  after  it  has  been  scoured.  For  this  reason,  silk  hatha 
should  be  old,  and  have  the  coloring  particles  accumulated  in  them,  but  so  feebly  sus- 
pended as  to  yield  to  a  weak  affinity.  Their  precipitation  is  counteracted  by  the  addi- 
tion of  gum,  or  other  mucilaginous  substances.  The  obstacles  which  might  arise  from 
the  sulphuric  acid  set  at  liberty  is  destroyed  by  iron  filings,  or  other  basis.  Thus, 
baths  of  a  very  different  composition,  but  with  the  essential  condition  of  age,  may  be 
proper  for  this  dye.     For  cotton  black  dye,  see  Calico  Printing. 

Blue-bldck  dye. — The  mordant  much  employed  in  some  parts  of  Germany  for  this 
dye,  with  logwood,  galls,  sumach,  <fcc.,  is  iron-alum,  so  called  on  account  of  its  having 
the  crystalline  form  of  alum,  though  it  contains  no  alumina.  It  is  prepared  by  dissolv- 
ing 78  pounds  of  red  oxide  of  iron  in  117  pounds  of  sulphuric  acid,  diluting  this  com- 
pound with  water,  adding  to  the  mixture  87  pounds  of  sulphate  of  potash,  evaporating 
the  solution  to  the  crystallizing  point.  This  potash  sulphate  of  iron  has  a  fine  amethyst 
color  when  recently  prepared;  and  though  it  gets  coated  in  the  air  with  a  yellowish 
crust,  it  is  none  the  worse  on  this  account  As  a  mordant,  a  solution  of  this  salt,  in 
from  6  to  60  parts  of  water,  serves  to  communicate  and  fix  a  great  variety  of  uniform 
ground  colors,  from  light  gray  to  brown,  blue,  or  jet  black,  with  quercitron,  galls,  log- 
wood, sumach,  <fec.,  separate  or  combined.  The  above  solution  may  be  usefully  mom- 
fied  by  adding  to  every  10  pounds  of  the  iron-alum,  dissolved  in  8  gallons  (80  pounds) 
of  warm  water,  10  pounds  of  acetate  (sugar)  of  lead,  and  leaving  the  mixture,  after 
careful  stirring,  to  settle.  Sulphate  of  lead  falls,  and  the  oxide  of  iron  remains  com- 
bined with  the  acetic  acid  and  the  potash.  After  passing  through  the  above  mordant, 
the  cotton  goods  should  be  quickly  dried. 

BLACK  PIGMENT.  The  finest  light  black  is  prepared  principally  for  the  manu- 
facturing of  printers'  ink.  In  Messrs.  Martin  and  Grafton's  patent  process,  the  black 
is  obtained  by  burning  common  coal-tar,  which  should,  however,  be  previously  divest- 
ed, as  much  as  possible,  of  the  ammoniacal  liquor  and  acid  mbced  with  it  in 
the  tank. 

For  this  purpose,  it  is  proposed  that  four  casks  should  be  employed,  each  capable  of 
holding  130  gallons,  and  into  every  one  of  them  are  to  be  put  about  60  gallons  of  the 
rough  impure  tar,  to  which  an  equal  quantity  of  lime-water  is  to  be  added,  and  then 
agitated  by  machinery  or  manual  labor  until  the  June-water  is  completely  mixed  with 
the  tar.  The  vessels  should  next  be  suffered  to  rest  ibr  about  six  hours,  by  which  time 
the  tar  will  settle  at  the  bottom  of  the  casks,  and  the  water  may  be  drawn  off.  The 
casks  containing  the  tar  should  now  be  filled  with  hot  water,  which  may  be  supplied 
from  the  boiler  of  a  steam  engine,  and  the  whole  again  agitated  as  before.  This  process 
may  be  repeated  three  times,  suffering  the  tar  to  subside  between  each ;  and  twelve 
hours  should  be  allowed  for  settling  from  the  last  water,  so  that  the  whole  of  the  tar  and 
water  may  become  separated,  the  water  rising  to  the  top  of  the  cask,  and  the  tar  being 
left  at  the  bottom  in  a  pure  state. 

But,  as  some  of  the  water  will  yet  remain  mechanically  combined  with  the  tar,  it  is 
proposed  that  the  tar  should  be  subjected  to  the  process  of  distillation.  For  this 
purpose,  a  still,  capable  of  holding  120  gallons,  may  be  employed,  in  which  about 
50  gallons  at  one  time  may  be  operated  upon ;  when,  by  a  gentle  heat,  the  water,  and 
other  impurities  which  the  tar  may  have  retained,  will  be  driven  off.  As  soon  as  the 
water  appears  to  ha  'e  evaporated,  and  the  spirit  runs  fine  and  clear,  the  process  of 
distillation  should  be  stopped ;  and,  when  cold,  the  pure  tar  may  be  drawn  off,  and  set 
a'^art  for  the  purpose  of  being  employed  as  contemplated  in  the  patent. 

The  tar  thus  purified  may  be  now  converted  into  black,  or  it  may  be  subjected  to 
farther  rectification  to  divest  it  of  the  mineral  pitch,  or  asphaltum,  which  is  combined 


f' 


with  the  oil  and  spirit:  the  latter  is  to  be  preferred,  because  the  mineral  pitch,  or 
asphaltum,  is  only  inflammable  at  a  high  temperature,  which  renders  it  more  trouble- 
some to  use  in  the  procc-ss  here  contemplated,  and  also  would  cause  the  apparatus  to 
require  frequent  cleaning  from  the  carbonized  pitch  deposited.  In  order,  therefore,  to 
get  rid  of  the  mineral  pitch,  or  asphaltum,  forty  gallons  of  the  tar  are  to  be  introduced 
into  a  still,  as  before ;  and,  instead  of  stopping  the  operation,  as  soon  as  the  spirit  begins 
to  come  over,  the  distillation  is  continue^  with  a  strong  heat,  so  as  to  force  over  the 
whole  of  the  oil  and  spirit,  leaving  the  residuum  of  asphaltum  in  the  still;  this  process, 
however,  is  known  to  every  chemist,  and  need  not  be  further  explained. 

In  jig.  128,  is  exhibited  a  rude  representauon  of  the  appaiatus  employed  in  preparing 
and  collecting  the  fine  light  spirit  black,  produced  by  the  combustion  of  the  oil  and 


spirit  of  coal-tar  after  it  has  been  purified  as  above  described,  a  is  the  brickwork 
which  supports  a  number  of  burners  issuing  from  a  tube,  6,  within,  and  here  shown  by 
dots,  as  passing  along  its  whole  length.  Fig.  129.  is  a  section  of  the  brickwork,  with 
the  tube  burner,  and  receiver,  as  will  be  described  hereafter.  The  tube  may  be  called 
the  tar  main,  as  it  is  intended  to  be  filled  with  tar:  it  is  constructed  of  cast  iron,  and 
from  it  issue  several  (in  this  figure  twenty-four)  jets  or  burners,  c.  c,  c  ;  any  other 
number  may  be  employed,  d  is  a.  furnace  under  the  tar  main,  the  flue  of  which 
extends  along,  for  the  purpose  of  heating  the  tar  to  the  boiling  point,  in  order  to 
facilitate  the  process.  Erom  the  main,  6,  the  tar  flows  into  the  jets  c;  wicks  are 
introduced  into  the  jets,  and,  when  set  fire  to  by  a  red-hot  stick,  will  burn  and  emit  a 
very  considerable  quantity  of  smoke  ;  which  it  is  the  object  of  this  apparatus  to  con- 
duct through  many  passages,  for  the  purpose  of  collecting  its  sooty  particles. 

There  are  a  number  of  hoods,  e,  e,  e,  or  bonnets,  as  they  are  termed,  all  of  which, 
through  their  pipes,  have  communication  with  or  lead  into,  a  main  chimney,  /,  f.  Into 
these  hoods  or  bonnets  the  smoke  of  the  burners  ascends,  and  from  thence  passes  into 
the  main  chimney/,  and  thence  through  the  smoke  tubes  into  the  box  ff;  here  the 
heaviest  particles  of  the  black  deposit  themselves ;  but,  as  the  smoke  passes  on  through 
the  farthest  pipes,  a  deposit  of  the  second,  or  finer,  particles  of  black  takes  place  in  the 
box,  h.  From  hence  the  smoke  proceeds  through  other  pipes  into  a  series  of  canvaa 
bags,  t,  t,  t,  which  are  proposed  to  be  about  18  feet  long,  and  3  in  diameter.  These  bags 
are  connected  together  at  top  and  bottom  alternately,  and  through  the  whole  series 
the  smoke  passes  up  one  bag  and  down  the  next,  depositing  fine  black,  called  spirit 
black,  upon  the  sides  of  the  convas.  AfteV  the  jets  have  continued  burning  for 
several  days,  the  bags  are  to  be  beaten  with  a  stick,  so  that  the  black  may  fall  to  the 
bottom ;  and  when  a  sufficient  quantity  has  accumulated,  the  bags  may  be  emptied 
and  swept  out  Thus  seventy  or  eighty  bags  may  be  employed ;  so  that  the  smoke  should 
pass  through  a  length  of  about  400  yards,  the  farthest  of  which  will  be  found  to  con- 
tain the  finest  black.  The  last  bag  should  be  lefl  open,  in  order  to  allow  the  vapor 
to  escape  into  the  open  air. 

The  main  tar  tube  will  require  to  be  emptied  every  four  or  five  days,  in  order  to 
dear  it  from  the  pitchy  matter  that  may  have  subsided  from  the  burners,  and  they 
also  will  require  to  be  frequently  poked  with  a  wire,  to  clear  off  the  black  which 
forms  upon  the  edges,  and  to  drive  down  the  carbonized  tar  which  attaches  itself  to 
the  upper  part  of  the  jets. 

A  fine  lamp-black  is  obtained  by  the  combustion  of  a  thick  torch  of  coal-gas,  sup- 


«l 


18i 


BLEACHING. 


plied  with  a  quantity  of  air  adequate  to  bum  only  its  hydrogen.  In  this  case,  the 
whole  of  its  carbon  is  deposited  in  the  form  of  a  very  fine  black  powder  of  extreme 
lightness.     This  black  is  used  in  making  the  better  qualities  of  printers'  ink. 

BLACKING  FOR  SHOES.     {Cirage  des  bottea,  Fr.;  Schuhschwarze.) 

The  following  prescription  for  making  liquid  and  paste  blacking  is  given  by  Wil- 
liam Bryant  and  Edward  James,  under  the  title  of  a  patent,  dated  December,  1836. 
Their  improvement  consists  in  the  introduction  of  caoutchouc,  with  the  view,  possibly, 
of  making  the  blacking  waterproof: — ^ 

18  ouuces  of  caoutchouc  are  to  be  dissolved  in  about  9  pounds  of  hot  rape  oil.  To 
this  solution  60  pounds  of  fine  ivory  black,  and  45  pounds  of  molasses,  are  to  be  added, 
along  with  1  pound  of  finely  gr«;ind  gum  arabie,  previously  dissolved  in  20  gallons  of 
vinegar,  of  strength  No.  24.  These  mixed  ingredients  are  to  be  finely  triturated  in  a 
paint  mill  till  the  mixture  becomes  perfectly  smooth.  To  this  varnish  12  pounds  of 
eulphuric  acid  are  to  be  now  added  in  small  successive  quantities,  wuth  powerful  stir- 
ring for  half  an  hour.  The  blacking  thus  compounded  is  allowed  to  stand  for  14 
days,  it  being  stirred  half  an  hour  daily  ;  at  the  end  of  which  time,  3  pounds  of  fine- 
ly-ground gum  arabie  are  added ;  after  which  the  stirring  is  repeated  half  an  hour 
every  day  for  14  daj^s  longer,  when  th^liquid  blacking  is  ready  for  use. 

In  making  the  paste  blacking,  the  patentees  prescribe  the  above  quantity  of  India 
rubber  oil,  ivory  black,  molasses,  and  gum  arabie,  the  latter  being  dissolved  in  only 
12  pounds  of  vinegar.  These  ingredients  are  to  be  well  mixed,  and  then  ground  to- 
gether in  a  mill  till  they  form  a  perfectly  smooth  paste.  To  this  paste  12  pounds  of 
sulphuric  acid  are  to  be  added  in  small  quautities  at  a  time,  with  powerful  stirring, 
which  is  to  be  continued  for  half  an  hour  after  the  last  portion  of  the  acid  has  been 
introduced.     This  paste  will  be  found  fit  for  use  in  about  7  days. 

BLACK  SILK  DYE|NG.  In  dyeing  silk,  "  the  hat-black  color;'  it  has  been  usual 
to  employ  nitrate  of  iron  as  a  mordant,  and  oak  bark  as  the  dye  stuff,  but  Mr.  Le  Lei- 
rre  has  found  that  alder  bark  is  preferable  ;  in  the  next  process  fustic  has  been  em- 
ployed, but  equal  parts  of  fustic  and  citron  bark  are  to  be  preferred  ;  and  the  paten- 
tee proposes  to  finish  the  process  with  a  lather  of  olive  oil,  soap  and  logwood. 

In  stretching  silk  so  dyed  he  does  it  in  an  atmosphere  of  steam,  by  placing  a  per- 
forated tube  connected  with  a  steam  boiler  close  under  the  silk  while  being  stretched. 

BLEACHING  (Blanchimenty  Fr. ;  Bleichen,  Germ.)  is  the  process  by  which  the  tex- 
tile filaments,  cotton,  flax,  hemp,  wool,  silk,  and  the  cloths  made  of  them,  as  well  as  va- 
rious vegetable  and  animal  substances,  are  deprived  of  their  natural  color,  and  rendered 
nearly  or  altogether  white.  The  term  bleaching  comes  from  the  French  verb  blanchir,  to 
whiten.  The  word  blanchy  which  has  the  same  origin,  is  applied  to  the  whitening  of 
living  plants  by  making  them  grow  in  the  dark,  as  when  the  stems  of  celery  are  covered 
over  witli  mould. 

The  operations  which  the  bleacher  has  recourse  to  differ  according  to  the  nature  of 
the  bleaching  means,  the  property  of  the  stufl'  to  be  bleached,  and  local  customs  or  cir- 
cumstances; and  the  result  is  also  obtained  with  more  or  less  rapidity,  certainty, 
economy,  and  perfection.  The  destruction  of  the  coloring  matters  attached  to  the  bodies 
to  be  bleached  is  eflected  either  by  the  action  of  the  air  and  light,  of  chlorine,  or  sulphu- 
rous acid ;  which  may  be  considered  the  three  bleaching  powers  employed  for  manufac- 
turing purposes. 

Bleaching  by  the  influence  of  air  and  sunshine  is  the  most  ancient,  and  still  the  most 
common,  method  in  several  civilized  countries ;  it  is  also  supposed  by  many  to  be  the 
least  injurious  to  the  texture  of  yam  and  cloth.  The  operations  it  involves  are  very 
simple,  consisting  in  the  exposure  of  the  goods  upon  a  grass-plat  to  the  skj',  with  their 
occasional  aspersion  with  moisture  if  necessary,  in  addition  to  the  rain  and  dew.  The 
atmospheric  air  effects  the  bleaching  by  means  of  its  oxygenous  constituent,  which  com- 
bines with  the  coloring  matter,  or  its  elements  carbon  and  hydrogen,  and  either  makes  it 
nearly  white,  or  converts  it  into  a  substancj  easily  soluble  in  water  and  alkaline  solutions. 
This  natural  process  is  too  slow  to  suit  the  modern  demands  of  the  cotton  and  linen 
manufacturers.  Fortunately  for  them,  a  new  bleaching  agent,  unknown  to  our  forefathers, 
has  been  discovered  in  chlorine,  formerly  called  oxymuriatic  acid,  an  agent  modified  by 
chemistry  so  as  to  give  an  aslonishin?  degree  of  rapidity,  economy,  and  perfection,  to  this 
important  art.  It  is,  however,  not  a  little  surprising,  that  the  science  which  has  so  greatly 
advanced  its  practical  part  should  have  left  its  theory  far  from  complete,  and  should  afford 
no  satisfactory  answers  to  the  two  following  questions. — What  is  the  action  of  the  solar 
rays  upon  the  coloring  matter  ?  How  do  air  and  chlorine  operate  upon  this  principle  ? 
Some  suppose  that  light  predisposes  the  coloring  matter  to  combine  with  oxygen  ;  others 
fancy  that  it  acts  merely  in  the  manner  of  a  high  temperature,  so  as  to  determine  a 
reaction  between  the  elements  of  that  substance,  and  to  cause  a  new  combination 
I>ossessed  of  peculiar  properties.  It  is  generally  admitted  at  the  present  day,  that  a 
portion  of  the  oxygen  of  the  air  passes  into  the  coloring  matter,  and  changes  its  con- 


BLEACHING. 


186 


Btitution.  This  is,  however,  probably  not  the  part  which  oxygen  plays,  nor  is  it  the  only 
principle  in  the  atmosphere  which  exercises  a  bleaching  influence.  Neither  is  the  action 
of  chlorine  such  as  has  been  commonly  represented  in  our  chemical  systems. 

But  if  authors  offer  us  only  vagjiie  hypotheses  concerning  the  three  principal  agents, 
light,  oxygen,  chlorine,  they  afford  no  information  whatever  concerning  the  phenomena 
due  to  sreasy  spots  so  frequently  found  upon  cotton  cloth,  and  so  very  tnmblesome  to 
the  bleacher.  It  has  indeed  been  sometimes  said  in  bleach-works,  that  fatty  sub- 
stances are  no  longer  soluble  in  alkalis,  wheff  they  are  combined  with  oxygen.  The 
very  reverse  of  this  statement  is  probably  nearer  the  truth. 

The  object  of  bleaching  is  to  separate  from  the  textile  fibre,  by  suitable  operations,  all 
the  substances  which  mask  its  intrinsic  whiteness :  or  which,  in  the  coui-se  of  ulterior 
dyeing  operations,  may  produce  injurious  effects.  In  this  latter  respect,  cotton  deserves 
especial  consideration.  This  substance  is  covered  with  a  resinous  matter,  which  obstructs 
its  absorption  of  moisture,  and  with  a  yellow  coloring  matter  in  very  small  quantity, 
often  so  inconsiderable  in  some  cottons,  that  it  would  be  unnecessary  to  bleach  them, 
before  submitting  them  to  the  dyer,  were  it  not  that  the  manipulations  which  they 
undergo  introduce  certain  impurities  which  are  more  or  less  injurious,  and  must  be 
removed.  It  is  in  fact  a  circumstance  well  known  in  the  factories,  that  unbleached 
cottons  may  be  dyed  any  dark  color,  provided  they  are  deprived  of  that  matter  which 
makes  them  difficult  to  moisten.  The  substances  present  in  couon  goods  are  the 
following : — 

1.  The  resinous  matter  natural  to  the  cotton  filaments. 

2.  The  proper  coloring  matter  of  this  vegetable. 

3.  The  paste  of  the  weaver. 

4.  A  fat  matter. 

5.  A  cupreous  soap. 

6.  A  calcareous  soap, 

7.  The  filth  of  the  hands. 

8.  Iron,  and  some  earthy  substances. 

1.  The  matter  which  prevents  the  moistening  of  cotton  wool  may  be  separated  by 
means  of  alcohol,  which,  when  evaporated,  leaves  thin  yellowish  scales,  soluble  in  alkalis, 
in  acids,  and  even  in  a  large  quantity  of  boiling  water.  For  a  long  time  the  bleaching 
process  commenced  with  the  removal  of  this  resinous  stuff,  by  passing  the  cloth  or  the 
yarn  through  an  alkaline  ley.    This  was  called  scouring ;  it  is  now  nearly  laid  aside. 

2.  The  coloring  matter  of  cotton  seems  to  be  superficial,  and  to  have  no  influence 
on  the  strength  of  the  fibres ;  for  the  yarn  is  found  to  be  as  strong  after  it  has  been 
stripped  by  caustic  soda  of  its  resinous  and  coloring  matters,  as  it  was  before.  The 
coloring  matter  is  slightly  soluble  in  water,  and  perfectly  in  alkaline  leys.  When  gray 
calico  is  boiled  in  lime-water,  it  comes  out  with  a  tint  darker  than  it  had  before;  whence 
It  might  be  supposed  that  the  coloring  matter  was  not  dissolved  out,  even  in  part. 
This,  however,  is  not  the  case ;  for  if  we  filter  the  liquor,  and  neutralize  it  with  an  acid, 
we  shall  perceive  light  flocks,  formed  of  the  resinous  substance,  united  with  the  coloring 
matter.  The  dark  color  of  the  cloth  is  to  be  ascribed  solely  to  the  property  which  lime 
possesses  of  browning  certain  vegetable  colors.  This  action  is  here  exercised  upon  the 
remaining  color  of  the  cloth. 

It  may  be  laid  down  as  a  principle,  that  the  coloring  matter  is  not  directly  soluble 
by  the  alkalis ;  but  that  it  becomes  so  only  after  having  been  for  some  time  exposed  to 
the  joint  action  of  air  and  light,  or  after  having  been  in  contact  with  chlorine.  What 
change  does  it  thereby  experience,  which  gives  it  this  solubility  ?  Experiments  made 
upon  pieces  of  cloth  placed  in  humid  oxygen,  in  dry  oxygen,  in  moist  chlorine,  and  in  dry 
chlorine,  tend  to  show  that  hydrogen  is  abstracted  by  the  atmosphere ;  for  in  these 
experiments  proofs  o£  dis-hydrogenation  appeared,  and  of  the  production  of  carbonic  acid. 
In  all  cases  of  bleaching  by  chlorine,  this  principle  combines  immediately  with  the 
hydrogen  of  the  coloring  matter,  and  forms  muriatic  acid,  while  the  carbon  is  elimi- 
nated. Undoubtedly  water  has  an  influence  upon  this  phenomenon,  since  the  bleaching 
process  is  quicker  with  the  humid  chlorine  than  with  the  dry ;  but  this  liquid  seems  to 
act  here  only  mechanically,  in  condensing  the  particles  of  the  gas  into  a  solution.  We 
should  also  take  into  account  the  great  affinity  of  muriatic  acid  for  water. 

3.  The  weaver's  dressing  is  composed  of  farinaceous  matters,  w^hich  are  usually  allowed 
to  sour  before  they  are  employed.  It  may  contain  glue,  starch,  gluten ;  which  last  is 
very  soluble  in  lime-water. 

4.  When  the  dressing  gets  dry,  the  hand-weaver  occasionally  renders  his  warp-threads 
more  pliant  by  rubbing  some  cheap  kind  of  grease  upon  them.  Hence  it  happens,  that 
the  cloth  which  has  not  been  completely  freed  from  this  fatty  matter  will  not  readily 
imbibe  water  in  the  different  bleaching  operations  ;  and  hence,  in  the  subsequent  dyeing 
or  dunging,  these  greasy  spots,  under  peculiar  circumstances,  somewhat  like  lithosrraphic 
stones,  strongly  attract  the  aluminous  and  iron  mordants,  as  well  as  the  dye-slufffi,  and 


186 


BLEACHING. 


BLEACHING. 


187 


occasion  stains  which  it  is  almost  impossible  to  discharge.  The  acids  act  differently 
upon  the  fatty  matters,  and  thence  remarkable  anomalies  in  bleaching  take  place.  When 
oil  is  treated  with  the  acetic  or  muriatic  acid,  or  with  aqueous  chlorine,  it  evolves  no 
gas,  as  it  does  with  the  sulphuric  and  nitric  acids,  but  it  combines  with  these  substances 
so  as  to  form  a  compound  which  cannot  be  dissolved  by  a  strong  boiling  ley  of  caustic 
soda.  Carbonic  acid  acts  in  the  same  way  with  oil.  On  the  other  hand,  when  the  oils 
and  fats  are  sufficiently  exposed  to  the  air,  they  seize  a  portion  of  its  oxygen,  and 
become  thereby  capable  of  saponification,  that  is,  very  soluble  in  the  alkalis. 

5.  When  the  hand-weaver's  grease  continues  in  contact  for  a  night  with  the  dopper 
dents  of  his  reed,  a  kind  of  cupreous  soap  is  formed,  which  is  sometimes  very  difficult  to 
remove  from  the  web.  Lime-water  does  not  dissolve  it ;  but  dilute  sulphuric  acid  carries 
off  the  metallic  oxyde,  and  liberates  the  margaric  acid,  in  a  state  ready  to  be  acted  on  by 
alkalis. 

6.  When  cloth  is  boiled  with  milk  of  lime,  the  grease  which  is  uncombined  unites 
with  that  alkaline  earth ;  and  forms  a  calcareous  soap,  pretty  soluble  in  a  great  excess  of 
lime-water,  and  still  more  so  in  caustic  soda.  But  all  fats  and  oils,  as  well  as  the  soape 
of  copper  and  lime,  cease  to  be  soluble  in  alkaline  leys,  when  they  have  remained  a  con- 
siderable time  upon  the  goods,  and  have  been  in  contact  with  acetic,  carbonic,  muriatic 
acids,  or  chlorine.    These  results  have  been  verified  by  experiment. 

7.  Cotton  goods  are  sometimes  much  soiled,  from  being  sewed  or  tamboured  with  dirty 
hands ;  but  they  may  be  easily  cleansed  from  this  filth  by  hot  water. 

8.  Any  ferruginous  or  earthy  matters  which  get  attached  to  the  goods  in  the  course  of 
bleaching,  are  readily  removable. 

We  are  now  prepared  to  understand  the  true  principles  of  bleaching  cotton  goods,  for 
the  most  delicate  operations  of  the  calico  printer. 

1.  The  first  process  is  steeping,  or  rather  boiling,  the  goods  in  water,  in  order  to  re- 
move all  the  substances  soluble  in  that  liquid. 

2.  The  next  step  is  to  wash  or  scour  the  goods  by  the  dash-wheel  or  the  stocks.  This 
is  of  great  importance  in  the  course  of  bleaching,  and  must  be  repeated  several  times;  so 
much  so,  that  in  winter,  when  the  water  of  the  dash-wheel  is  cold,  the  bleaching  is 
more  tedious  and  difficult.  Yarn  and  very  open  fabrics  do  not  much  need  the  dash- 
wheel. 

By  these  first  two  operations,  the  woven  goods  lose  about  sixteen  per  cent,  of  their 
weight,  while  they  lose  only  two  parts  out  of  five  hundred  in  all  the  rest  of  the 
bleaching. 

3.  In  the  third  place  the  calicoes  are  boiled  with  milk  of  lime,  whereby  they  are 
stripped  of  their  gluten,  and  acquire  a  portion  of  calcareous  soap.  Formerly,  and  still 
in  many  bleach-works,  the  gluten  was  got  rid  of  by  a  species  of  fermentation  of  the 
farinaceous  dressing ;  but  this  method  is  liable  to  several  objections  in  reference  to  the 
calico  printer.  1.  The  fermentative  action  extends  sometimes  to  the  goods  and  weakens 
their  texture,  especially  when  they  are  piled  up  in  a  great  heap  without  being  previously 
washed.  2.  The  spots  of  grease,  or  of  the  insoluble  soaps,  become  thereby  capable  of 
resisting  the  caustic  alkalis,  and  are  rendered  in  some  measure  indelible ;  an  effect  due 
to  the  acetic  and  carbonic  acids  generated  during  fermentation,  and  which  will  be  easily 
understood  from  what  has  been  said  concerning  the  action  of  acids  on  fatty  substances. 
It  Ls  not,  therefore,  without  good  reason  that  many  practical  men  throw  some  spent  leys 
into  the  fermenting  vats,  to  neutralize  the  acids  which  are  formed.  Were  it  not  for  the 
presence  of  fat,  fermentation,  skilfully  conducted,  would  be  an  excellent  means  of  car- 
rying off  the  gluten;  and  the  steep  is  therefore  applicable  to  power-loom  goods,  which 
are  not  polluted  with  grease. 

4.  The  goods  are  now  subjected  to  a  caustic  soda  ley,  which  dissolves  out  the  soaps 
of  lime  and  copper,  as  well  as  that  portion  of  the  coloring  matter  which  is  sufficiently 
dis-hydrogenated  to  be  capable  of  combining  with  it.  This  bucking  with  ley,  which  is 
repeated  several  times  upon  the  goods,  in  order  to  purge  them  completely  from  the  fatty 
matter  present  in  the  hand-loom  webs,  and  also  partidly  introduced  in  the  spinning,  is 
almost  the  only  operation  to  which  yarns  for  Turkey  red  are  subjected.  After  being 
boiled  in  a  caustic  soda  ley,  they  are  passed  through  solutions  of  chloride  of  lime,  and 
afterwards  through  the  acid  steep. 

5.  When  the  goods  are  sufficiently  bucked  in  the  leys,  they  are  eitter  exposed  to 
chlorine,  or  laid  out  on  the  grass ;  sometimes  both  are  had  recourse  to  for  delicate  work. 
These  different  modes  of  action  have  the  same  influence  on  the  coloring  matter,  but 
they  give  rise  to  different  effects  in  reference  to  greasy  stains. 

The  goods  are  dipped  in  a  solution  of  chloride  of  lime,  which  should  be  kept  tepid 
by  means  of  steam.  Alongside  of  the  chlorine  cistern,  there  is  another  filled  with  dilute 
sulphuric  or  muriatic  acid.  When  the  goods  are  taken  out  of  the  chlorine,  they  are 
drained  on  the  top  of  its  cistern  till  no  more  liquid  runs  off  them,  and  they  are  then 
plunged  into  the  sour.    The  action  of  the  acid   in  the  present  case  may  be  easily  ex- 


plained. In  proportion  as  a  salt  of  lime  is  formed,  this  base  quits  the  chlorine,  and  allows 
it  to  act  freely  upon  the  coloring  matter.  Thus  we  prevent  the  development  of  too  great 
a  quantity  of  chlorine  at  once,  which  would  be  apt  to  injure  the  fibres;  and  we  pursue 
both  a  prudent  and  economical  plan.  Only  so  much  chlorine  as  is  strictly  necessary  is 
called  forth,  and  hence  it  excites  no  smell  in  the  apartment.  •        r  •     ». 

The  chlorine  serves  to  acidify  the  coloring  matter,  by  abstracting  a  portion  of  its  hy- 
drogen; but  we  must  lake  the  greatest  care  that  there  is  no  grease  upon  the  goods  before 
immersion  in  it,  for  the  consequence  would  be,  as  above  shown,  very  troublesome  spots. 
When  the  cloth  is  laid  out  upon  the  grass,  it  is  the  oxygen  of  the  air  which  acidifies  the 
coloring  matter ;  for  which  reason,  the  dew,  which  contains  much  air  rich  in  oxygen,  sin- 
gularly^accelerates  the  bleaching  process.  It  is  likewise,  by  absorbing  oxygen  from  the 
atmosphere,  that  fats  or  oils  pass  to  the  state  of  margaric  and  oleic  acids,  and  become 
most  easily  saponified.  Should  the  goods,  however,  be  left  too  long  on  the  grass,  the  faU 
absorb  carbonic  acid,  and  become  insoluble  in  leys. 

6.  The  goods  must  now  receive  a  new  soda  ley,  to  dissolve  out  that  portion  of  the 
coloring  matter  which  has  been  dis-hydrogenated  in  the  chlorine  of  the  air,  as  well  as 
the  grease,  if  any  perchance  remained  in  the  soluble  state.  These  last  two  operations 
are  to  be  several  times  repeated,  because  the  coloring  matter  should  be  removed  only  by 
degrees,  for  fear  of  injuring  the  texture  of  the  goods,  by  subjecting  them  to  too  much 
chlorine  at  a  time. 

7.  We  finish  with  the  dilute  sulphuric  acid,  which  should  be  very  weak  and  tepid.  It 
dissolves  out  the  iron,  and  some  earthy  matters  occasionally  found  upon  cotton.  The 
goods  must  be  most  carefully  washed  at  the  dash-wheel,  or  in  a  stream  of  water  on  quit- 
ting the  sour  ba  h,  for  if  the  acid  were  allowed  to  dry  in  them,  it  would  infallibly  injure 
their  texture  by  its  concentration.  In  winter,  if  the  goods  are  allowed  to  get  frozen  with 
the  acid  upon  them,  they  may  likewise  be  damaged. 

We  may  here  observe,  that  when  the  goods  are  not  to  remain  white,  their  bleaching 
may  be  completed  with  a  ley ;  for  though  it  leaves  a  faint  yellow  tint,  this  is  no  incon- 
venience to  the  dyer.  But  when  they  are  to  be  finished  with  a  starching  after  the  last 
ley,  they  must  have  another  dip  of  the  chlorine  to  render  the  white  more  perfect.  An 
immersion  in  the  dilute  acid  has  nearly  the  same  effect. 

The  principles  expounded  above  lead  to  this  important  consequence,  that  when  we 
wish  to  bleach  goods  that  are  free  from  greasy  stains,  as  is  the  case  generally  with  the 
better  kinds  of  muslins,  or  when  we  wish  to  bleach  even  greasy  goods  for  the  staieh 
finish,  we  may  content  ourselves  with  the  following  operations : — 

1.  Boiling  in  water. 

2.  Scouring  by  the  stocks  or  the  dash-wheeL 

3.  Bucking  with  milk  of  lime. 

4.  Passing  through  chlorine,  or  exposure  on  the  grass. 

5.  Bucking,  or  bouking  with  milk  of  lime.  These  two  latier  operations  require  to  be 
alternated  several  times,  till  the  whole  of  the  coloring  matter  be  removed. 

6.  Souring. 

The  bleaching  of  goods,  which  are  never  laid  down  on  the  green,  and  which  are  not 
dried  between  two  operations,  may  be  conipleled  in  a  couple  of  days.  They  answer  as 
well  for  the  printer  as  the  others,  and  they  are  as  white.  Cotton  fibres  or  yarns  suffer 
no  diminution  of  their  strength,  when  the  cloth  has  been  properly  treated  in  the  above 
described  processes. 

Accurate  experiments  hare  demonstrated  that  their  strength  is  not  impaired  by  being 
boiled  in  milk  of  lime  for  two  hours  at  the  ordinary  pressure,  provided  thcv  be  constantly- 
kept  covered  with  liquid  during  the  whole  ebuUilion,  and  that  they  be  well  washed  im- 
mediately afterwards ;  or,  by  being  boiled  in  pure  water  under  the  pressure  of  ten  atmos- 
pheres of  steam;  or  by  being  boiled  under  the  same  pressure  in  a  caustic  soda  ley,  mark- 
ing 3°  of  Tweedale,  or  specific  gravity  1*015,  though  it  has  increased  to  double  the  density 
in  the  course  of  the  boil,  by  the  escape  of  the  steam  ;  or  by  being  boiled  nnderthe  atmos- 
pheric pressure  at  14°  of  Tweedale,  or  specific  gravity  of  1*070  ;  or  by  being  immersed 
for  eight  hours  in  chloride  of  lime,  capable  of  decoloring  three  times  its  bulk,  of  test  so- 
lution of  indigo  (See  Chlorine)  ;  and  by  being  afterwards  dipped  in  sulphuric  acid  of 
specific  gravity  1-067,  Tweedale  14° ;  or  by  being  steeped  for  eighteen  hours  in  sulphu- 
ric or  muriatic  acid  of  specific  gravity  1*035,  7°  Tweedale. 

In  other  well-conducted  bleach-works  the  following  is  the  train  of  operations : — 
1.  Cleansing  out  the  weaver's  dressing  by  steeping  the  cloth  for  twelve  hours  in  cold 
water,  and  then  washing  it  at  the  stocks  or  the  dash-wheel.  2.  Boiling  in  milk  of  lime, 
of  a  strength  suited  to  the  quality  of  the  goods,  but  for  a  shorter  time  than  with  the 
soda  ley;  two  short  operations  with  the  lime,  with  intermediate  washing,  being  prefer- 
able to  one  of  greater  duration.  3  and  4.  Two  consecutive  leys  of  ten  or  twelve  hours* 
boiling,  with  about  two  pounds  of  soda  chrystals  for  1  cwt.  of  cloth.  5.  Exposure  to 
the  air  for  six  or  eight  days,  or  the  application  of  the  chloride  of  lime  and  the  sulphuric 


k 


_J 


1^ 


h: 


LI  : 
in 


186 


BLEACHING. 


acid.  6.  A  ley  of  caustic  soda,  like  the  former,  sometimes  with  less  alkali.  7.  Exposure 
to  the  air  for  six  or  eight  days,  or  chlorine  and  the  sour,  as  above.  8.  Caustic  soda  ley, 
as  before.  9.  Chlorine  and  the  sour.  10.  Rinsing  in  hot  water,  or  scourine  at  the 
dash-wheel. 

If  the  numoer  of  vessels  to  be  heated  exceeds  four  or  five,  there  is  an  economy  in 
using  steam  as  the  medium  of  heat ;  but  under  this  number  there  is  an  advantage  in 
the  direct  application  of  fire  to  a  boiling  or  bucking  apparatus;  since  when  only  two 
vessels  are  in  activity,  there  is  a  waste  of  fuel  by  the  extra  steam  power.  It  deserves  to 
be  remarked,  also,  that  the  increase  of  the  bulk  of  the  liquid  by  the  condensation  of  the 
steam,  does  not  permit  the  spent  white  ley  to  be  turned  to  use  for  the  green  goods,  on  ac- 
count of  Its  excessive  dilution.  With  the  milk  of  lime  boil,  however,  this  dilution 
would  be  rather  an  advantage. 

Tt  has  been  found  that  the  introduction  of  bran  into  the  fermenting  steep  (when  this  is 
used)  endangers  the  texture  of  the  goods,  by  causing  a  putrefactive  fermentation  in  some 
places. 

When  in  the  milk  of  lime  boU  there  is  too  much  of  this  caustic  earth,  or  when  it  is 
poured  in  on  the  top  of  the  goods,  they  are  apt  to  suffer  damage.  The  milk  of  lime  should 
be  introduced  from  beneath  into  the  under  compartment  of  the  bucking  apparatus.  For 
the  same  reason,  after  the  caustic  soda  ley,  the  vessel  should  be  filled  up  with  water,  if 
the  goods  be  not  immediately  transferred  to  the  dash-wheel.  When  they  are  allowed  to 
become  partiaUy  dry  on  the  top,  they  are  easily  injured.  The  copper  of  the  bucking  ap- 
paratus ought  to  be  of  a  size  proportioned  to  that  of  the  surmounting  crib  or  vat ;  for 
when  It  IS  too  small,  the  liquid  is  too  long  of  being  brousrht  into  proper  circulation,  and 
the  goods  may  be  meanwhile  injured.  In  a  bucking  apparatus,  which  requires  five  or  six 
homrs  to  be  brought  into  fuU  play,  those  goods  are  very  apt  to  be  injured,  which  Ue  im- 
mediately under  the  overflow  pipe. 

AVhen  the  chbride  of  lime  steep  is  too  strong,  sometimes  small  round  holes  are  made 
in  the  calico,  just  as  if  they  had  been  cut  out  by  a  punch,  especially  in  the  borders  or 
thicker  parts  of  the  goods.  This  accident  is  owing  to  the  presence  of  bubbles  of  chlorine, 
l-rom  the  saturated  state  of  the  Hquid,  they  remain  gaseous  a  sufficient  length  of  tune  for 
corroding  the  parts  of  the  cloth  with  which  they  are  in  contact.  These  will  be  obviously 
the  denser  parts,  for  they  confine  the  gas  most  completely,  or  prevent  its  difl'usion  through 
tne  mass.  I  his  evil  is  prevented  by  diluting  the  chloride  steep  to  the  proper  degree,  and 
moving  the  goods  through  it.  i-  *-    *•         o      , 

The  greasy  spots,  described  above,  show  themselves  in  the  maddering  by  attracting  the 
dye-stuff  more  copiously  than  the  pure  parts  of  the  cloth,  so  as  to  mottle  it ;  they  are  also 
recognised  in  the  white  goods  by  being  somewhat  repulsive  of  moisture.  When  the  com- 
bmation  of  fatty  matters  with  chlorine  takes  place  at  the  surface  of  cotton  goods,  it  is  of 
a  nature  to  resist  the  action  of  alkalis.  It  is  the  stearine,  or  the  principle  of  suet,  par- 
ticularly, which,  by  this  means,  acquires  such  a  strong  affinity  for  cottons ;  the  elaine,  or 
the  principle  of  oils,  has  no  such  remarkable  affinity.  Lime,  in  some  circumstances, 
seems  to  act  as  a  mordant  to  greasy  matters,  and  to  fix  them  fast.  Hence  the  weaver 
snould  be  prohibited,  m  all  cases,  from  allowing  candle-grease  to  touch  his  web.  Goods 
soiled  with  it  should  never  be  allowed  to  lie  by  in  the^ware-house,  but  be  immediately 
cleansed  before  the  air  has  fixed  the  stearine  by  converting  it  into  margaric  acid.  Lime 
snould,  m  these  cases,  be  prudently  employed ;  chlorine  should  never  be  used  till  the  greasy 
stains  are  thoroughly  removed;  and  the  bleacher  should  never  warrant  his  pieces  for  the 
printer  till  he  has  verified  some  of  them  by  the  water  test. 

I  shall  conclude  this  general  analysis  of  the  principles  of  bleaching  by  a  few 
precepts.  Avoid  lime,  at  the  first  ley,  for  goods  which  contain  creasy  spots ;  but  use 
It  ireeJy  atler  one  or  two  soda  leys,  and  apply  two  soda  leys  after  it.  Do  not  apply 
chlorine  between  these  leys,  but  reserve  it  for  the  final  operation.  By  this  plan  the 
goods  will  be  well  bleached  and  very  little  worn.  Use  the  souring  steeps  freely, 
^'J-"?*i.  ^"^'"  ^^*^^  ^^y*  whether  of  lime  or  soda,  since  the  calcareous  base,  with 
which  the  greasy  spots  get  charged  merely  from  hard  water,  is  an  obstacle  to  the  further 
action  of  the  leys. 

I  shall  now  give  some  practical  instructions  concerning  the  several  steps  of  the  bleach- 
ing process,  as  applied  to  cotton,  linen,  silk,  and  wool. 

The  first  thing  which  the  cotton  bleacher  does,  is  to  mark  the  pieces  with  the  initials 
of  the  owner,  by  means  of  a  stamp  imbued  with  coal  tar.  The  linen  bleacher  marks 
with  nitrate  of  silver,  a  far  more  expensive  substance,  but  one  which  resists  better  the 
severer  treatment  which  his  goods  are  destined  to  undergo. 

The  cotton  goods  are  generally  singed  before  they  are  sent  to  the  bleacher,  and  this  is 
done  either  by  passing  them  rapidly  over  a  red-hot  semi-cylinder  of  iron,  or  over  a  row 
of  gas  flames,  by  Mr.  HaU's  ingenious  contrivance.  (See  Singeing.)  Each  piece  is  next 
creased  together  lengthwise  like  a  rope,  folded  into  a  bundle,  and  fixed  by  a  noose  at  the 
end.  In  this  open  state  it  is  easily  penetrated  by  the  water  of  the  soaking  cistern  into 
Which  it  is  thrown.     It  is  then  scoured  by  the  dash  or  wash-wheel.     It  is  now  ready  foi 


BLEACHING. 


189 


the  bucking  or  steaming  apparatus,  where  it  is  treated  with  milk  of  lime.  The  steam 
chamber  resembles  the  bucking  vessel,  without  its  bottom  copper;  that  is  to  say,  a  few 
inches  below  the  grated  bottom  of  the  bucking  tub,  there  is  a  close  iron  sole,  through 
the  centre  of  which  the  steam  is  admitted  by  several  small  apertures,  for  the  purpose  of 
dliff'using  it  throughout  the  goods,  and  causing  a  liquid  circulation  by  its  pressure,  as 
the  steam  does  in  the  proper  bucking  boiler.  One  pound  of  lime  previously  made  into 
n  cream  consistenced  mixture,  and  passed  through  a  sieve,  is  used  for  every  thirty  or  forty 
pounds  of  cloth,  according  to  its  color  and  texture ;  and  this  cream  mixed  with  more  water 
IS  interstratified  with  the  pieces,  as  they  are  laid  regularly  in  the  vessel.  Whenever  this 
is  stocked  with  goods,  all  their  interstices  are  filled  up  with  water.  After  the  lime 
bucking,  the  cloth  is  transferred  to  the  dash-wheel. 

A  pound  of  cloth  requires  for  its  whitening  about  half  a  pound  of  good  average 
chloride  of  lime  or  bleaching  powder,  as  it  is  commonly  called,  and  this  ought  to  be 
dissolved  in  about  three  gallons  of  water.  Mr.  Crum  of  Thorniebank,  near  Glasgow, 
an  extensile  and*  excellent  bleacher,  has  so  modified  Dr.  Dalton's  ingenious  plan  of 
testing  the  power  of  bleaching  liquors  by  green  sulphate  of  iron,  as  to  give  it  much 
greater  precision  for  the  bleacher's  use,  than  the  discoloration  of  indigo  originally  pro- 
posed by  Berthollet.  Mr.  Crum  dissolves  four  ounces  of  fresh  green  vitriol  in  hot  water, 
and  then  adds  the  solution  of  bleaching  powder  by  small  quantities  at  a  time,  till  the 
iron  becomes  wholly  peroxydized,  when  the  smell  of  chlorine  will  become  perceptible. 
When  the  bleacher  has  once  found  by  trial  the  proper  blanching  power  which  his  chlorine 
steep  ought  to  have,  he  can  verify  its  standard,  by  seeing  how  much  of  it  must  be  added 
to  an  ounce,  or  any  given  weight  of  fresh  copperas,  dissolved  in  hot  water,  to  cause  the 
peroxydizement  and  the  exhalation  of  the  peculiar  odor.  M.  Gay  Lussac's  new  method 
by  arsenious  acid  will  be  described  under  chlorine.  From  the  experiments  which  I 
made  some  years  ago,*  upon  indigo,  it  will  be  seen  that  this  dye  stuff  is  so  variable  in 
its  quantity  of  coloring  matter,  that  no  two  chemists  operating  with  it  independently, 
as  a  test  for  chloride  of  lime,  could  arrive  at  the  same  result.  They  must  provide 
themselves  with  absolute  indigo,  by  an  expensive  and  troublesome  process,  not  suited  to 
the  busy  bleacher.  The  vitriolage,  as  the  French  term  it,  or  the  souring  of  the  English 
bleacher,  consists  in  immersing  the  goods  for  four  hours  in  dilute  sulphuric  acid,  con- 
taining one  gallon  of  oil  of  vitriol  to  from  25  to  30  of  water,  thoroughly  intermixed  by 
stirring ;  for  the  density  of  the  acid  is  an  obstacle  to  its  equal  distribution  through  the 
water.  This  dilute  acid  will  have  a  density  of  from  1047  to  1*040,  and  will  contain 
from  7  to  6|  per  cent,  by  weight  of  the  oil  of  vitriol. 

The  goods  are  now  washed,  and  then  boiled  for  eight  or  nine  hours  in  an  alkaline 
ley,  containing  about  two  pounds  of  crystals  of  soda,  or  their  equivalent  in  soda  ash  or 
pearl-ash,  for  every  100  lbs.  of  cloth.  The  ley  must  be  made  previously  caustic  by 
quick  lime.  A  washing  in  the  wheel  follows  this  boil ;  and  then  a  chlorine  steep  for 
five  hours  in  a  liquor  two  thirds  of  the  strength  of  the  former.  It  is  next  soured  in  the 
dilute  sulphuric  acid,  for  two,  three,  or  four  hours,  according  to  the  color  and  quality 
of  the  cotton,  and  then  thoroughly  washed. 

The  cloth  is  now  bleached  white,  but  cannot  be  presented  in  the  market  till  it 
undergoes  certain  finishing  processes.  The  piece  is  elongated  from  the  folds  which  it 
contracts  during  the  rotation  of  the  dash-wheel  by  being  thrown  into  a  stream  of  water 
in  a  cistern,  terminated  by  the  squeezing  rollers,  which  take  in  the  end  of  the  piece,  and 
run  it  through  between  them,  with  the  effect  of  making  it  nearly  dry.  Two  pieces  of 
cloth  pass  simultaneously  through  the  rollers,  and  are  disentangled  spontaneously,  so  to 
speak,  without  the  help  of  hands. 

The  squeezing  rollers  or  squeezers,  for  discharging  the  greater  part  of  the  water  from 
the  yarns  and  goods  in  the  process  of  bleaching,  are  represented  in  Jigs.  130,  131,  the 

131  "3 


*  Quarlerlx  Journal  of  Science,  Literature,  and  the  Art»,  vol.  vii.  p.  160 


l^ 


190 


BLEACHING. 


BLEACHING. 


191 


f 


former  being  a  side-view,  to  show  how  the  roller  gudgeons  lie  in  the  slots  of  the  fram^ 
and  how  the  shaft  of  the  upper  roller  is  pressed  downward  by  a  weighted  lever,  through 
a  vertical  junction  rod,  jointed  at  the  bottom  to  a  nearly  horizontal  bar,  on  whose  end 
the  proper  weight  is  hung.  In  yig.  118,  these  rollers  of  birch- wood  are  shown  in  face  ; 
the  under  one  receiving  motion  through  the  toothed  wheel  on  its  shaf\,  from  any  suitable 
power  of  water  or  steam.  Upon  the  sliafi  of  the  latter,  between  the  toothed  wheel  and 
the  roller,  the  lever  and  pulley  for  putting  the  machine  into  and  out  of  gear  are  visible. 
The  under  roller  makes  about  25  revolutions  in  the  minute,  in  which  time  three  pieces 
of  goods,  stitched  endwise,  measuring  28  yards  each,  may  be  run  through  the  machine, 
from  a  water  trough  on  one  side,  to  a  wooden  grating  upon  the  other. 

When  the  goods  are  run  through,  they  are  carried  off  upon  a  grated  wheelbarrow,  in 
a  nearly  dry  state,  and  transferred  to  the  spreading  machine,  called  at  Manchester  a 
candroy.  In  many  bleach-works,  however,  the  creased  pieces  are  pulled  straight  by  the 
hands  of  women,  and  are  then  strongly  beat  against  a  wooden  stock  to  smooth  out  the 
edges.  This  being  done,  a  number  of  pieces  are  stitched  endwise  together,  preparatory 
to  being  mangled. 

Calender. — Fig. 
Fiews  broken  off. 


132  is 
The 


goods 


132 


cross  section  of  this  machine,  and  Jigs.  133,  134,  are  front 
are  first  rolled  npon  the  wooden  cylinder  o,  near  the 
133  134 


ground;  by  the  tension  roller  6,  upon  the  same  cylinder,  the  goods  receive  a  proper 
degree  of  stretching  in  the  winding  off.  They  then  pass  over  the  spreading  bars  c  c  c, 
by  which  they  are  still  more  distended ;  next  round  the  hollow  iron  cylinder^ rf,  16  inches 
diameter,  and  the  paper  cylinder  e,  of  like  dimensions ;  thence  they  proceed  under  the 
second  massive  iron  cylinder  /,  of  8  inches  diameter,  to  be  finally  wound  about  the  pro- 
jecting wooden  roller  g.  This  is  set  in  motion  by  the  pulleys  h,fig.  121,  and  i,fig.  J20, 
and  receives  its  proper  tension  from  the  haneing  roller  k ;  I  is  a.  press  cylinder,  of  14 
inches  diameter,  made^of  plane-tree  wood.  By  its  means  we  can  at  all  times  secure  an 
equal  deeree  of  pressure,  which  would  be  hardly  possible  did  the  weighted  lever  press 
immediately  upon  two  points  of  the  calender  rollers.  The  compression  exercised  by 
the  cylinders  may  be  increased  at  pleasure  by  the  bent  lever  m,  weights  being  applied 
to  it  at  n.  The  upper  branch  of  the  lever  o  is  made  fast  by  screws  and  bolts  at  ;>,  to 
the  upper  press-cylinder.  The  junction  leg  q  is  attached  to  the  intermediate  piece  r,  by 
left  and  richt-handed  screws,  so  that  according  as  that  piece  is  turned  round  to  the  right 
or  the  left,  the  pressure  of  the  weighted  roller  will  be  either  increased  or  diminished.  By 
turning  it  still  more,  the  piece  will  get  detached,  the  whole  pressure  will  be  removed,  and 
the  press-roller  may  be  taken  off;  which  is  a  main  object  of  this  mechanism. 

The  unequable  movement  of  the  cylinders  is  produced  by  the  wheels  s  t  u,  of  which 
the  undermost  has  69,  the  uppermost  has  20,  and  the  carrier-wheel  /,  either  33, 32,  or  20 
teeth,  according  to  the  difference  of  speed  required.  The  carrier-wheel  is  bolted  on  at 
V,  and  adjusted  in  its  proper  place  by  means  of  a  slot.  To  the  undermost  iron  cylinder, 
the  first  motion  is  communicated  by  any  power,  for  which  purpose  either  a  rigger 
(driving  pulley)  is  applied  to  its  shaft  at «,  or  a  crank  motion.    If  it  be  desired  to 


operate  with  a  heated  calender,  the  undermost  hollow  cylinder  may  be  filled  whh  hot 
steam,  admitted  through  a  stufiing-box  at  one  end,  and  discharged  through  a  stuffing-box 
at  the  other,  or  by  a  red-hot  iron  roller. 

Pure  starch  would  be  too  expensive  a  dressing  for  common  calico  shirtings,  and  there- 
fore an  extemporaneous  starch  is  made  by  mixing  one  pound  of  flour  with  one  gallon  of 
water,  and  aUowing  the  mixture  to  ferment  in  a  warm  place  for  twenty-four  hours.  In 
this  way,  a  portion  of  lactic  acid  is  formed,  which  dissolves  the  gluten,  or  separates  it 
from  the  starch ;  so  that  when  the  whole  is  thrown  upon  a  sieve,  a  liquid  paste  passes 
through,  which,  being  boiled,  answers  well  for  stiffening  the  goods,  without  giving  them 
a  gray  tinge.  The  paste  is  thinned  with  water  to  the  desired  degree,  and  faintly  tinged 
with  solution  of  indigo.  The  starch,  which  is  sometimes  thickened  with  porcelain  clay, 
Paris  plaster,  or  Spanish  white,  is  put  into  a  trough,  and  is  evenly  imparted  to  the  cloth  as 
this  is  drawn  down  through  it,  by  the  traction  of  rollers.  There  is  a  roller  near  the 
bottom  of  the  trough,  round  which  the  cloth  is  made  to  run,  to  secure  its  full  impresna- 
tion ;  while  the  upper  rollers  serve  to  expel  its  excess  of  the  starch,  and  throw  it  back 
mto  the  cistern.     See  Starching  Apparatus. 

The  goods  are  next  dried  in  an  apartment  heated  by  two,  three,  or  more  flues,  running 
along  the  floor,  and  covered  usually  with  fire-tiles.  At  fiist  the  heat  is  moderate,  but  it 
is  gradually  raised  to  upwards  of  1 10°  F. 

The  goods  must  now  be  passed  again  through  the  calender,  in  order  to  receive  their 
final  smoothness  and  lustre.  They  are,  in  the  first  place,  damped  with  a  peculiar  ma- 
chine, furnished  with  a  circular  brush,  whose  points  revolve  in  contact  with  water  in  a 
trough  placed  beneath  them,  and  sprinkle  drops  of  water  upon  the  goods  as  they  are 
drawn  fon\^ard  by  a  pair  of  cylinders.  They  are  then  subjected  to  the  powerful  pressoie 
of  the  calender  rollers. 

The  calendered  pieces  are  neatly  folded  into  compact  parcels,  and  stamped  with  the 
marks  of  each  particular  manufacturer,  or  various  devices  to  suit  the  markets  for  which 
they  are  designed.  They  are  finally  piled  on  the  sole  of  an  hydraulic  press,  with  a  sheet 
of  pasteboard  between  each  piece;  but  with  occasional  plates  of  iron  to  secure  uniformity 
of  pressure  throughout.  When  sufficiently  condensed  by  the  press,  they  are  taken  out, 
and  despatched  to  their  respective  manufacturers  in  a  state  ready  for  sale. 

There  are  no  less  than  25  steps  in  the  bleaching  of  calicoes,  many  of  them  effected 
with  expensive  machinery ;  yet  the  whole  do  not  produce  to  the  bleacher  more  than  10 
pence  per  piece  of  24  yards. 

The  following  system  was  pursued,  a  few  years  back,  by  a  skilful  bleacher  of  muslins 
near  Glasgow : — 

"  In  fermenting  muslin  goods,  we  surround  them  with  our  spent  leys,  from  the  tem- 
perature of  100°  to  150°  F.,  according  to  the  weather,  and  allow  them  to  ferment  for 
36  hours.  In  boihng  112  lbs.  =  112  pieces  of  yard-wide  muslin,  we  use  6  or  7  lbs  of 
pearl-ashes,  and  2  lbs.  of  soft  soap,  with  360  gallons  of  water,  and  allow  them  to  boil  for 
6  hours ;  then  wash  them,  and  boil  them  again  with  5  lbs.  of  pearl-a<?he«  and  2  lbs  of 
soft  soap,  and  allow  them  to  boil  3  hours ;  then  wash  them  with  water,  and  immerse 
them  mto  the  solution  of  oxymuriate  of  lime,  at  5  on  the  test-tube,  and  allow  them  to 
•remam  from  6  to  12  hours;  next  wash  them,  and  immerse  them  into  dilute  sulphuric  atid 
at  the  specific  gravity  of  3i  on  Tweedale's  hydrometer  =  1.0175,  and  aUow  them  to 
remain  an  hour.  They  are  now  weU  washed,  and  boiled  with  2i  lbs.  of  pearl-ashes,  and 
21bs.of  soft  soap  for  half  an  hour;  after\vards  washed  and  immersed  into  the  oxvmu- 
riate  of  lime  as  before,  at  the  strength  of  3  on  the  test-tube,  which  is  stronger  than  the 
former,  and  aUowed  to  remam  for  6  hours.  They  are  again  washed,  and  immersed  in 
diluted  sulphuric  acid  at  the  specific  gravity  of  3  on  Tweedale's  hydrometer  =1^15 
II  the  goods  be  strone,  they  will  require  another  boil,  steep,  and  sour.  At  anv  rate  the 
sulphuric  acid  must  be  well  washed  out  before  they  receive  the  finishing  operation  with 

"  With  regard  to  the  lime,  which  some  use  instead  of  alkali  immediately  after  ferment- 

In^t  t  r.n'-^';'' W  •'  i  '"'P^'^'??  "'  "^  pearl-ashes.     The  goods  areXwei Tt^U 
m  It  for  15  minutes,  but  no  longer,  otherwise  the  lime  will  injure  the  fabric  » 

duJJd'forXtVd'on  tXt''^'  ^  "  ''"°"^'  ''  "^^^^  ^^^  P--'  -^^-  -  P- 

and  fhT:irf  do^irklep^^^^^^^^  ^^  ''  '^  '^^^'  '^  ^i^  *^-  ^^»>"^ 

."■^'*,.^.^^''};"^.l^y^°^a<le  by  boiling  equal  weights  of  lime  and  soda  together  for  an 
hour :  this  alkali  IS  used  for  boiling  goods  the  same  as  potash,  but  without  soap 
ihJL ""^  ^T"^^'  °'  muslins  after  washing  them  from  the  sour,  they  are  run 
tijrough  spnng-water  contammg  a  little  fine  smalts,  which  give  them  ;  clear  shad^ 
LLt^"'"''^^*^''"''/  little  well-boiled  starch  is  added  to  the  water.  From  thisthev 
are  wrung  or  pressed,  and  taken  up  by  the  selvage  for  the  breadthing  frame,  and  are 
run  off  u  upon  a  tm  cylinder  heated  by  steam,  by  which  the  piece  is  com^e  JfrdriS 


192 


BLEACHING. 


BLEACHING. 


I 

1 


% 


i 


Ml  15  mmntes :  it  is  then  stripped  from  the  cylinder,  neatly  folded  and  pressed,  which 
finishes  the  piece  for  the  market.  From  6d.  to  9d.  per  piece  of  12  yards  is  obtained  for 
the  bleaching  and  finishing  of  those  goods. 

**  Book  muslins,  after  being  washed  from  the  sour,  are  wrung  or  pressed  ;  then  they  are 
hnng  up  to  dry  in  a  heated  stove,  previous  to  being  put  into  starch,  prepaied  by  boiling 
3  lbs.  of  it  to  every  5  gallons  of  water,  with  20  ounces  of  smalts :  they  are  wrung  out  of 
this  starch,  and  taken  to  a  room  heated  to  110°  F. ;  the  starch  is  wrought  into  the  piece 
till  clear,  then  taken  into  a  cold  room,  and  the  selvages  dressed  or  set,  before  being  put 
on  the  breadlhing  frame  in  the  heated  stove,  where  the  piece  is  stretched  to  its  length, 
while  three  or  four  persons  at  each  selvage  keep  the  piece  to  its  breadth.  If  a  stifl"  finish 
is  wanted,  they  keep  exactly  opposite  each  other ;  but  in  breadlhing  the  piece  of  elastic, 
they  cross  the  piece  in  breadthing,  which  gives  it  a  springy  elastic  finish.  From  9d.  to 
15i.  per  piece  of  12  yards  is  obtained  for  the  bleaching  and  finishing  of  these  goods. 

"  Sewed  trimmings,  flounces,  and  dresses  are  run  through  spring  water  containing  fine 
smalts  with  a  little  well-boiled  starch.  They  are  then  taken  to  the  drying-stove,  where 
they  are  stented  till  dry,  which  finishes  the  piece  for  the  market.  From  6d.  to  8d.  per 
piece  is  obtained  for  trimmings  and  flounces,  and  from  9d.  to  Is.  for  dresses,  bleaching 
and  finishing." 

In  the  bleaching  of  cotton  cloth,  where  fixed  colors  are  previously  dyed  in  the  yam 
before  it  is  woven  into  cloth,  such  as  the  Turkey  or  Adrianople  red,  and  its  compounds 
of  lilach  or  purple,  by  the  addition  of  iron  bases,  various  shades  of  blue  from  indigo,  together 
with  buff"  and  gold  color,  tinged  with  the  oxydes  of  iron,  great  care  is  necessary. 
^  The  common  process  of  bleaching  pulicates,  into  which  permanent  colors  are  woven, 
B,  to  wash  the  dressing  or  starch  well  out  in  cold  water ;  to  boil  them  gently  in  soap, 
and,  after  again  washing,  to  immerse  them  in  a  moderately  strong  solution  of  the  oxy- 
muriate  of  potash  ;  and  this  process  is  followed  until  the  white  is  good  :  they  are  then 
soured  in  dilute  sulphuric  acid.  If  the  goods  are  attended  to  in  a  proper  manner,  the 
colors,  in  place  of  being  impaired,  will  be  found  greatly  improved,  and  to  have  acquired 
a  delicacy  of  tint  which  no  other  process  can  impart  to  them. 

Pulicates,  or  ginghams,  which  have  been  woven  along  with  yarn  which  has  been  pre- 
viously bleached,  are  first  freed  by  washing  from  the  starch  or  dressing :  they  are  then 
washed,  or  slightly  boiled  with  soap.  After  which,  they  are  completely  rinsed  in  pure 
spring  water,  and  then  soured. 

Besides  these  common  processes  for  bleaching,  another  was  some  time  ago  introduced, 
which  consisted  in  immersing  the  cotton  or  linen  goods  in  pretty  strong  solution  of  caus- 
tic alkali,  and  afterwards  exposing  them  to  the  action  of  steam  in  a  close  vessel.  It  is 
now  generally  abandoned. 

The  cotton  or  linen  goods,  having  been  previously  cleaned  by  steeping  and  washing, 
were,  after  being  well  drained,  steeped  in  a  solution  of  caustic  alkali  of  the  specific  gravity 
of  1020.  After  Jhe  superfluous  alkaline  ley  had  been  drained  from  them,  they  were  ar- 
ranged on  a  grating  in  a  receiver.  The  cover  was  then  placed  on  the  vessel,  and  firmly 
screwed  down;  and  the  steam  was  admitted  by  turning  the  stopcock  of  the  pipe  which 
communicated  with  a  steam  boiler  of  the  common  construction. 

^  The  stains  which  come  out  upon  maddered  goods,  in  consequence  of  defective  bleach- 
ing, are  called  in  this  country  spangs.  Their  origin  is  such  as  I  have  described  above, 
as  the  following  statement  of  facts  will  show.  The  weaver  of  calicoes  receives  frequently 
a  fine  warp  so  tender  from  bad  spinning  or  bad  staple  in  the  cotton,  that  it  will  not  beai* 
the  ordinary  strain  of  the  heddles,  or  friction  of  the  shuttle  and  reed,  and  he  is  obliged 
to  throw  in  as  much  weft  as  will  compensate  for  the  weakness  or  thinness  of  the  warp, 
and  make  a  good  marketable  cloth.  He  of  course  tries  to  gain  his  end  at  the  least 
expense  of  time  and  labor.  Hence,  when  his  paste  dressing  becomes  dry  and  stiff",  he  has 
recourse  to  such  greasy  lubricants  as  he  can  most  cheaply  procure ;  which  are  commonly 
either  tallow  or  butter  in  a  rancid  state,  but  the  former,  being  the  lowest  priced,  is  pre- 
ferred. Accordingly,  the  weaver,  having  heated  a  lump  of  iron,  applies  it  to  a  piece  of 
tallow  held  over  the  warp  in  the  loom,  and  causes  the  melted  fat  to  drop  in  patches  upon 
the  yarns,  which  he  afterwards  spreads  more  evenly  by  his  brush.  It  is  obvious,  however 
that  the  grease  must  be  very  irregularly  applied  in  this  way,  and  be  particularly  thick  on 
certain  spots.  This  irregularity  seldom  fails  to  appear  when  the  goods  are  bleached  or 
dyed  by  the  common  routine  of  work.  Printed  calicoes  examined  by  a  skilful  eye  will 
be  often  seen  to  be  stained  with  large  blotches  evidently  occasioned  by  this  vile  practice 
of  the  weaver.  The  ordinary  workmen  call  these  copper  stains,  believing  them  to  be 
communicated  in  the  dyeing  copper.  Such  stains  on  the  cloth  are  extremely  injurious  in 
dyeing  with  the  indigo  vat.  The  following  plan  is  adopted  by  some  Scotch  bleachers 
with  the  effect,  it  is  said,  of  eff*ectually  counteracting  spangs  from  grease.  ' 

The  goods  having  been  singed  and  steeped  in  pure  water,  as  is  customary  in  common 
bleaching,  they  are  passed  through  a  pair  of  rollers  to  press  out  the  impurities  which 
have  been  loosened  by  the  steeping.    It  must  here,  however,  be  observed,  that  where  the 


193 


expense  of  one  extra  drying  can  be  afibrded,  the  process  might  be  very  much  improved 
by  steeping  the  bro^vn  calicoes  for  thirty  or  forty  hours  before  singemg,  because  fiis  would 
separate  much  of  that  impurity  which  usually  becomes  fixed  in  the  stuflT  on  its  bein<'  pass- 
ed over  the  hot  cylinders.  When  the  pieces  have  been  thus  singed,  steeped,  and  pressed 
rhey  are  boded  four  times,  ten  or  twelve  hours  at  each  time,  in  a  solution  of  caustic  pot- 
ash, of  the  specific  gravity  of  from  1-0127  to  1-0156,  washing  them  carefully  and  thoroiSh- 
ly  m  pure  water  between  each  of  these  boilings.  They  are  then  immersed  in  a  solution 
of  the  chloride  of  potash,  originally  of  the  strength  of  1-0625,  and  afterwards  reduced 
with  twenty-four  times  its  measure  with  water. 

When  the  preparation  is  good,  these  proportions  wUl  whiten  cotton  goods  completely  in 
eight  hours.  In  this  steep  they  are,  however,  generaUy  suff^ered  to  remain  twelve  hours. 
It  has  been  supposed  that  the  common  bleaching  liquor  (chloride  of  lime)  cannot,  without 
injury,  be  substituted  for  chloride  of  potash,  but  I  believe  this  to  be  a  mistake. 

Some  printers  take  the  pieces  from  this  solution,  and,  while  wet,  lay  them  upon  the 
^ass,  and  there  expose  them  to  the  sun  and  weather  for  two  or  three  days.     They  arc 

Su^rnf'i'^^^^frFA  'h">  '  f'^l''^'^-  'P''^  -"^''"'y  °^  «^"t  10254  at  the  temper- 
fTilf>lf  «^^^^'-f»^^»t-  .J^  bleaching  common  goods,  and  such  as  are  not  designed 
of  1  nl^«  r^w  i?!l  '^l  '^ll'^^^^'-^'y  of  the  sours  is  varied  from  that  of  1-0146  to  that 
of  1-0238,  If  weighed  when  they  become  of  the  temperature  of  the  atmosphere.  In  these 
they  are  suff-ered  to  he  for  five  or  six  hours,  after  which  they  are  taken  to  the  dash-whed 
and  washed  thoroughly.  When  this  operation  is  finished,  theyare  submUted  to  four  more 
bodings  as  before,  wiih  a  solution  of  caustic  potash;  taking  care  to Tash  weU  betw^^ 
^ch  of  these  boilings     Sometimes  pearl-ash,  made  caustic,  is  used  frtheTast  of  JhSe 

^eZfi^''  ThVv"  ?"'  T''"'  ^^"Y^  'T^V? ''''  P«^^^^-  of  commerce  shTuW  iii^pS 
tne  whites.     They  are  next  immersed  m  the  diluted  chloride  of  potash,  of  the  strength 

rnrZ^rT""'^''  ^^'''  ^^^^'^  '^'^  "^  ^^^^  ^^«hed  in  pure  wa?er  and  then  wiS 
of  li  *"  ^"'  V"  '"'T^u^  ^'^'•'-  "^^^  ^^^t  P^«<^^ss  is  that  of  carefil  wasWn^  in  pleu^ 
of  clean  water  after  which  they  are  not  put  into  the  stove,  but  are  immediSefy  hung  u^ 
in  the  airing  sheds  to  dry  gradually.  The  water  must  be  good,  and  abundant.^  ^  ^ 
The  number  of  operations,  as  here  described,  is  great ;  but  I  know  of  no  other  mode 

~  wiTho^t'd'"'  ''''r  ''I'^f''''  ''  ''  ^^^^'^°  ^^  ^ff-t-'i  at  aU  times  anS  inl 
seasons,  without  disappointment.     It  must  here  be  remarked,  that,  for  the  best  ouroos^ 

of  printmg,  it  would  not  be  sufficient  to  take  goods  wWch  have  been  bleached^Th" 

«  nrint.r  ^if  •  ^J' .^hat  Operation  will  be  apt  to  spoil  them  for  madder  colors  at  leaTt. 
a  pr  nter  who  is  curious  m  his  business  would  hesitate  to  work  up  such  cloth    '  ^ 

of  wf coft^  f rfeo?.?  'Tu'  ''  ^'^  "^^^  ,^P«^^^^^  «P-' ^--  ^^^  bleaching 

remained  on  the  cloth  for  some  S^e  it  L  nTn  of?  k''^  T^  ^^'  ^''^''''''  ^^'  ^^^^^8 
kleve,  into  an  iron  boiler  surS  in  The  ^rS^S  fr  ^  I  ^^op-cock,  at  the  bottom  of  th? 
by  a  ^ump.  The  hea  Ts  now  devat  JJ^  «  h'-  k"^  .^^^''''^  '^  '^  "^'^'^  ^^^^  ^^'^  boiler 
upon  the  goods  irthekTeveTn,^ wh    ^'^f^^  ^^^  ^^^  again  run 

d^cribed  :  and  these  oneralfo'nsar?  ^nt"'^  ?  '',  '"'""^"^  ^°^°  '^^  ^'^^^  ^^  before 
alkaline  ley  is  compleX  .Zrated  ^TT^  f""-^^'  increasing  the  heat,  until  the 
which  is  known  byT  l^^vin-  arnnlr^  »  ^  ''"^"r^  T^'^'  ^^^^"^  ^^^"^  the  cloth, 
causticity.  ^  ^  *^^"''^  ^  completely  off-ensive  smell,  and  losing  its 

rnZ:\:L^lft,l%^^^^  upon  colored  vegetable 

increased.  Thus,  when  ^eSle  subst--!^^  '^^  •V'^  'l"'^"'^^  ^^^  ^^^"^  ^^^ually 
the  coloring  mattVr,  in  placf  of  be  n  '  ext  aLTis    b^^^^  T  ^"^"^^  ^'^^*^' 

•mo  them.  It  is  on  this  principle  that  a  cook  n^I  ■'  ^I  **»'^.b»Sher  temperature,  fixed 
color  of  vegetables  is  intend^  tVbepeseTved -i^nlL  ^"  i^^'^,,^'^'  7^^^^  ^^e  green 
cold,  tliey  are  kept  back  until  the  w^tPr  TJ  wr  ^T  °^  P"^^'''^  '^^"^  ^^«  "^^^^^  ^hen 
the  former  case,  he  -reen  color  wm,MK  .'^f^ '  ^^'^^""^  '^  ^  ^^^  ^nown  that,  in 
bles  are  not  infised  ,!nS"the  tat^rf^^^^^^^^^  tT'''^'  ^"I'^T'  "^^"  ^^^  ^'^^^^- 

On  the  same  principle  when  thp  t.ml  ♦  "'  the  color  is  completely  preserved  or  fixed, 
extractive  and  col,  r^ng  matter  is  ZIT.?  n  ^^'l^^^^^'^^^  ^'Y  ^^  ^adually  raised,  the 
reversed  when  the  ley  rappl fed  ^thf  Wi  ^  l^^'''  ^'^"^  *^^  *^^°'^'  ^"^  *^«  ^^^^  « 
which  has  been  so  unfortunate  a  An  mjl?  ^'^'i^'J?.  temperature  :  so  much  so,  that  linen 
t-ood  white.  ""^oriunate  as  to  meet  with  this  treatment,  can  never  be  brought  to  a 

When  the  alkaline  ley  is  saturated  with  coloring  matter,  it  is  run  off  as  unfit  for 


194 


BLEACHING. 


BLEACHING. 


/        i 

\: 

[ 

' 

It 


la  Jig- 


further  use  in  this  operation ;  but,  were  the  goods  to  be  instantly  taken  out  of  the 
kieve,  and  carried  to  be  washed  in  the  dash-wheel  while  hot,  a  certain  portion  of  the 
coloring  matter  would  be  again  fixed  into  ihera,  which  is  extremely  difficult  to 
eradicate.  In  order  to  prevent  this,  the  most  approved  bleachers  run  warm  water  upon 
the  cloth  as  soon  as  the  impure  ley  is  run  off:  this  combines  with  and  carries  ofl'part 
of  the  remaining  impurities.  A  stream  of  water  is  then  allowed  to  run  upon  the  cloth 
in  the  kieve,  until  it  comes  off  almost  transparent.  The  goods  are  now  to  be  taken 
to  the  wash  stocks,  or  to  the  dash-wheel,  to  be  further  cleaned,  with  the  greatest 

efficacy. 

The  improved  mode  of  bowking  was  the  invention  of  Mr.  John  Laurie,  a  native  of 
Glasgow.  It  is  now  practised  by  many  bleachers  in  Lancashire,  some  on  more  perfect 
plans  than  others ;  but  we  shall  give  the  description  of  the  kind  of  apparatus  approved 
of  by  those  whose  experience  and  skill  have  rendered  them  the  roost  competent 
judges. 

B  c  o  is  the  wooden  kieve,  or  kier,  containing  the  cloth;   c  e  f  i> 

represents  the  cast-iron  boiler ;  g  g,  the 
pump;  g  K,  the  pipe  of  communication 
between  the  kieve  and  the  boiler.  This 
pipe  has  a  valve  on  each  of  its  extremities ; 
that  on  the  upper  extremity,  when  shut, 
prevents  the  ley  from  running  into  the 
boiler,  and  is  regulated  by  the  attendant 
by  means  of  the  rod  and  handle  g  b. 
The  valve  at  k  admits  the  ley ;  but,  open- 
ing inwards,  it  prevents  the  steam  from 
escaping  through  the  pipe  g  K.  The 
boiler  has  a  steam-tight  iron  cover,  g  l; 
and  at  c  d,  in  the  kieve,  is  a  wooden 
grating,  a  small  distance  al>0Te  the  cover 
of  the  boiler. 

At  M  o  is  a  broad  plate  of  metal,  in 
order  to  spread  the  ley  over  the  cloth. 
It  is  hardly  necessary  to  say  that  the 
boiler  has  a  furnace,  as  usual,  for  similar 
purposes. 

While  the  ley  is  at  a  low  temperature 
the  pump  is  worked  by  the  mill  or  steam- 
engine.  When  it  is  sufficiently  heated,  the  elasticity  of  the  steam  forces  it  up  through 
the  valves  of  the  pump,  in  which  case  it  is  disjoined  from  the  moving  power. 

N  p  is  a  copper  spout,  which  is  removed  at  the  time  of  taking  the  cloth  out  of  the 
kieve. 

The  boQers  a,  Jig.  136,  used  in  bleaching,  are  of  the  common  form,  having  a  stop. 

cock,  H  G,  at  bottom,  for  running  off  the  waste  ley. 
They  are  commonly  made  of  cast-iron,  and  are  ca- 
pable of  containing  from  300  to  600  gallons  of  water, 
according  to  the  extent  of  the  business  done.  In 
order  that  the  capacity  of  the  boilers  maybe  enlarged, 
they  are  formed  so  as  to  admit  of  a  crib  of  wood, 
strongly  hooped,  or,  what  is  preferable,  of  cast-iron, 
to  be  fixed  to  the  upper  rim  or  edge  of  it.  To  keep 
the  goods  from  the  bottom,  where  the  heat  acts  most 
forcibly,  a  strong  iron  ring,  covered  with  netting 
made  of  stout  rope,  c,  is  allowed  to  rest  six  or  eight 
inches  above  the  bottom  of  the  boiler.  Four 
double  ropes  are  attached  to  the  ring  e,  for  with- 
drawing the  goods  when  sufficiently  boiled,  which 
have  each  an  eye  for  admitting  hooks  from  the 
running  tackle  of  a  crane.  Where  more  boilers 
than  one  are  employed,  the  crane  is  so  placed, 
that,  in  the  range  of  its  sweep,  it  may  withdraw  the  goods  from  any  of  them.  For  this 
purpose,  the  crane  turns  on  pivots  at  top  and  bottom ;  and  the  goods  are  raised  or  low- 
ered at  pleasure,  with  double  pulleys  and  sheaves,  by  means  of  a  cylinder  moved  by  cast- 
iron  wheels.  The  lid  is  secured  by  the  screw  bolts  d  d,  and  rings  b  b.  f  is  a  safety 
valve. 

The  efficacy  of  Laurie's  bowking  apparatus  is  remarkable.  While  the  heat  is 
gradually  rising,  a  current  of  fresh  ley  is  constantly  presented  to  the  difierent  surfaces 
for  saturating  the  goods,  so  as  to  increase  its  detersive  powers.     Besides,  the  manner  in 


195 


which  the  apparatus  is  worked,  first  by  the  water-wheel  or  steam-engine,  and  then  by  its 
intrinsic  operation,  puts  it  completely  out  of  the  power  of  servants  to  slight  the  work- 
not  to  speak  of  the  great  saving  of  alkali,  which,  in  many  cases,  has  been  found  to 
amount  to  25  per  cent. 

A  simple  modification  of  the  bowkmg  apparatus  is  shown  in  Jigs.  137,  138,  139  ;  the 

first   being  a  vertical  section,  the 
second,  a  horizontal  section  in  the 
line  X  of  the  first.     It  consists  of 
two  parts:  the  upper  wide  part, 
a  a,  serves  for  the  reception  of  the 
goods,  and  the  lower  or  pot,  b,  for 
holding  the  ley ;    c  c  is  an  iron 
grating,  shown  apart  in^g.  139, 
The  grating  has  numerous  square 
apertures   in    the   middle  of  the 
disc,  to  which  the  rising  pipe  d  is 
screwed  fast.     The  upper  cylinder 
is  formed  of  cast  iron,  or  of  sheet 
iron  well  riveted  at  the  edges ;  or 
sometimes    of   wood,   this    being 
secured  at  its  under  edge  into  a 
groove  in  the  top  edge  of  the  ley- 
pot.    The  mouth  of  the  cylinder 
is    constructed    usually    of    sheet 
iron,    e  «  is  the  fire-grate,  whose 
upper  surface  is  shown  in^g.  138  ; 
it  is  made  of  cast  iron,  in  thi  ee 
pieces.    The  flame  is  parted  at/,  and  passes  through 
the  two  apertures  g  g,  into  the  flues  A  A,  so  as  to  play 
round  the  pot,  as  is  visible  in^g.  138  ;  and  escapes  by 
two  outlets  into   the   chimney.     The  apertures  i  i 
serve  for  occasionally  sleaning  out  the  flues  h  h,  and 
are,  at  other  times,  shut  with  an  iron  plate.     In  the 
partition  /,  which  separates  the  two  openings  g  g, 
and  the  flues  h  h,  running  round  the  pot,  there  is  a 
circular  space  at  the  point  marked  with  kyjig.  138,  in 
which  the  large  pipe  for  dischai^ing  the  waste  ley  is 
lodged.     The  upper  large  cylinder  should  be  incased 
in  wood,  with  an  intermediate  space  filled  with  saw- 
dust, to  confine  the  heat.     The  action  of  this  appa- 
ratus is  exactly  the  same  as  of  that  already  explained. 
Besides   the  boiling,   buckinsr,   and   other  appa- 
ratus above  described,  the  machinery  and  utensils 
used   in   bleaching  are   various,   according   to   the 
business    done   by   the   bleacher.     When   linen  or 
heavy  cotton  cloths  are  whitened,  and  the  business 
is  carried  on  to  a  considerable  extent,  the  machines 
are  both   complicated   and  expensive.    They  con- 
sist chiefly  of  a  water-wheel,  sufficiently  powerful 
for  giving  motion  to  the  wash-stocks,  dash-wheels, 
squeezers,  &c.,  with   any  other   operations  where 
power  is  required. 

Figs.  140,  141,  represent  a  pair  of  wash-stocks. 
A  A  are  called  the  stocks,  or  feet.  They  are  sus- 
pended on  iron  pivots  at  b,  and  receive  their  mo- 
tion from  wipers  on  the  revolving   shaft  c.    The 


"M' 


i»Uth  .-c  i„:j  •       .  J  .      .         """  *'""'  wipers  on  me  revolvmg   shaft  c.     The 

'he  turnhrad  ;  'tL^^rl.  ^-^ '**'  ff""'"  ''''^''  of  the  feet,  and  the%urved  form  of 
abunSin?  stl»m  n?  ^l  ''  T'^*^  *"^  ^""^^"^"y  ^"™«J-  ^t  the  same  time,  an 
^rtu*nLad  ^/.h  c^^'^L ''"'*^^'  ^"J*^«  ^^^^^  throughout  holes  in  the  upper  part  ot 
^untrv  thev  kr^Tft  ?'  ^'l  ?^"*=^  "'^^  ^'^  Scotland  and  in  Ireland.     In  the  latter 

aTwrou.M  ^^.h  r  T^^  ^*th  double  feet,  suspended  above  and  below  two  turnheads, 
frl^Ttf^^ort'^^eTpt^n'^^^^^  ''  "^^"^-  ^-'-^-k«>  P-P-ly  constructed,  mak^ 
KivTn  to  wt.^f^71'n'"/ /'  now  entirely  given  up  in  Lancashire,  where  a  preference  is 
Ks?de  of  whfrh  il!?  tt'^^'^l'  *"^  squeezers.  The  dash  are  small  water-wheel^ 
inUrhtmUme'^^^^^^^^  eTo^"^"^^'  '^^  '''''''  "^'  ^^^^^'^^^  '^'  ^  ^^ 


196 


BLEACHING. 


There  are,  besides,  smaller  openings  for  the  free  admission  and  egress  of  the  water  em- 
ployed in  cleansing.    The  cloth,  by  the  motion  of  the  wheel,  is  raised  up  in  one  part  of 


141 


MM?^ . 


IL 


Q 


I  li 


the  revolution  of  the  wheel ;  while,  by  its  own  weight,  it  falls  in  another.  This  kind  oT 
motion  IS  very  effectual  in  washing  the  cloth,  while,  at  the  same  time,  it  does  not  injure 
Its  strength.  The  plan,  however,  where  economy  of  water  is  of  anv  importance,  is  very 
objectionable ;  because  the  wheel  must  move  at  by  far  too  great  a  Velocity  to  act  to  ad- 
vantage as  a  water-wheel. 

The  wash  or  dash-wheel,  now  driven  by  power  in  all  good  bleach  and  print- 
works, is  represented  in 
fig.  142,  upon  the  left  side 
in  a  back  view,  and  upon 
the  ri«»ht  side  in  a  front 
vipw  (the  sketch  being 
halved).  Fig,  HZ  is  a 
ground  plan. 

a  a  is  the  washing- wheel ; 
b  b  its  shaA-ends ;  c  c  their 
brass  bearings  or  plummer- 
blocks,  supported  upon  the 
iron  pillars  d  d.  The  frame 
is  made  of  strong  beams  of 
wood,  e  e,  bound  together 
by  cross  bars  with  mortises. 
/  /y  two  of  the  circular 
apertures,  each  leading  to 
a  quadrantal  compartment 
within  the  dash-wheel.  In 
the  back  view  (the  left-hand  half  of  the  figure)  the  brass  grating  g  g,  of  a  curvilinear 
fonn,  is  seen,  through  which  the  jets  of  water  are  admitted  into  the  cavity  of  the 

■  ■  ,   , .      wheel;  h  hy  are  the  round 

|C|3    U 


orifices,  through  which  the 
foul  water  runs  off,  as  each 
quadrant  passes  the  lower 
part  of  its  revolution ;  t,  a 
water-pipe,  with  a  stop-cock 
for  regulating  the  washing- 
jets  ;  k  ky  the  lever  for  throw- 
ing the  driving-crab  /,  or 
coupling-box,  into  or  out 
of  gear  with  the  shaft  of  the 
wheel.  This  machine  is  so 
constructed,  that  the  water- 
cock  is  opened  or  shut  by 
the  same  leverage  which 
throws  the  wheel  into  or 
out  of  gear,    wi,  a  wheel, 

-,      ./vi-vji-ti      ^.  ^^^  "PO"  *^^  round  ex- 

tremity of  the  shaft  of  the  dash-wheel,  which  works  into  the  toothed  pinion  connected 


» 


f 


I 


k 


BLEACHING. 


197 


with  the  prime  mover.  When  the  end  of  the  lever  fe,  whose  fork  embraces  the  coupling- 
box  upon  the  square  part  of  the  shaft,  is  pushed  forwards  or  backwards,  it  shifts  the  clutch 
into  or  out  of  gear  with  the  toothed  wheel  m.  In  the  latter  case,  this  wheel  turns  with 
its  pinion  without  affecting  the  dash-wheel,  n  n,  holdfasts  fixed  upon  the  wooden  frame, 
to  which  the  boards  o  o  are  attached,  for  preventing  the  water  from  being  thrown  about 
by  the  centrifugal  force. 

The  dash-wheel  is  generally  from  6  to  7  feet  in  diameter,  about  30  inches  wide,  and  re- 
quires the  power  of  about  two  horses  to  drive  it. 

From  one  to  two  pieces  of  calico  may  be  done  at  once  in  each  quadrantal  compartment, 
in  the  course  of  8  or  10  minutes ;  hence,  in  a  day  of  13  hours,  with  two  such  wheels 
1200  pieces  of  yard-wide  goods  may  be  washed. 

After  the  process  of  washing  by  the  dash-wheel,  the  water  is  expressed  from  the  dotk 
by  means  of  the  squeezers  already  described. 

Bleaching  of  Linen. — Linen  contains  much  more  coloring  matter  than  cotton.  The 
former  loses  nearly  a  third  of  its  weight,  while  the  latter  loses  not  more  than  a  twentieth. 
The  fibres  of  flax  possess,  in  the  natural  condition,  a  light  gray,  yellow,  or  blond  color. 
By  the  operation  of  rotting,  or,  as  it  is  commonly  called,  water-retting,  which  is  employed 
to  enable  the  textQe  filaments  to  be  separated  from  the  boon,  or  woody  matter,  the  color 
becomes  darker,  and,  in  consequence  probably  of  the  putrefaction  of  the  green  matter  of 
the  bark,  the  coloring  substance  appears.  Hence,  flax  prepared  without  rotting  is  much 
paler,  and  its  coloring  matter  may  be  in  a  great  measure  removed  by  washing  with 
soap,  leaving  the  filaments  nearly  white.  Mr.  James  Lee  obtained  a  patent  in  1812,  as 
having  discovered  that  the  process  of  steeping  and  dew-retting  is  unnecessary,  and  that 
flax  and  hemp  will  not  only  dress,  but  will  produce  an  equal  if  not  greater  quantity  of 
more  durable  fibre,  when  cleaned  in  the  dry  way.  Mr.  Lee  stated  that,  when  hemp  or 
flax  plants  are  ripe,  the  farmer  has  nothing  more  to  do  than  to  pull,  spread,  and  dry 
them  m  the  sun,  and  then  to  break  them  by  proper  machinery.  This  promising  im- 
provement has  apparently  come  to  naught,  having  been  many  years  abandoned  by  the 
patentee  himself,  though  he  was  favored  with  a  special  act  of  parliament,  which  permit- 
ted the  specification  of  his  patent  to  remain  sealed  up  for  seven  years,  contrary  to  the 
general  practice  in  such  cases. 

The  substance  which  gives  steeped  flax  its  peculiar  tint  is  insoluble  in  boiling  water, 
m  acids,  and  m  alkalis ;  but  it  possesses  the  property  of  dissolving  in  caustic  or  carbonated 
alkalme  leys,  when  it  has  possessed  the  means  of  dehydrogenati'on  by  previous  exposure 
to  oxygen.  Hemp  is,  in  this  respect,  analogous  to  flax.  The  bleaching  of  both  depends 
upon  this  action  of  oxygen,  and  upon  the  removal  of  the  acidified  dye,  by  means  of  an 
alkali.  This  process  is  effected  generally  by  the  influence  of  air  in  combination  with 
light  and  moisture  acting  on  the  linen  cloth  laid  upon  the  grass :  but  chlorine  will  effect 
the  same  object  more  expeditiously.  In  no  case,  however,  is  it  possible  to  acidify  the 
color  completely  at  once,  but  there  must  be  many  alternate  exposures  to  oxygen  or  chlo- 
rine, and  alkali,  before  the  flax  becomes  white.  It  is  this  circumstance  alone  which  ren- 
ders the  bleaching  of  linen  an  apparently  complicated  business. 

Having  made  ihese  preliminary  observations  with  regard  to  the  method  of  applying  the 
alkalme  leys  used  in  bleaching  linen  cloth,  I  shall  now  bring  the  whole  into  one  point  of 
view,  by  detailing  the  connexion  of  these  processes,  as  carried  on  at  a  bleach-field,  which 
has  uniformly  been  successful  in  returning  the  cloth  of  a  good  white,  and  has  otherwise 
given  ^tisfaction  to  its  employers ;  and  I  shall  only  remark,  that  I  by  no  means  hold  it 
up  as  the  best  process  which  may  be  employed,  as  every  experienced  bleacher  knows  that 
processes  must  be  varied,  not  only  according  to  existing  circumstances,  but  also  according 
to  the  nature  of  the  linens  operated  upon. 

In  order  to  avoid  repetition,  where  washing  is  mentioned,  it  must  always  be  under- 
stood that  the  hnen  is  taken  to  the  wash-stocks  or  dash-wheel,  and  washed  weU  in  them 
for  some  hours.  This  part  of  the  work  can  never  be  overdone;  and  on  its  being  properly 
executed  between  every  part  of  the  bucking,  boilin?,  steeping  in  the  chloride  of  lime 
solution,  and  souring,  not  a  little  of  the  success  of  bleaching  depends.  By  exposure  is 
meant,  that  the  linen  cloth  is  taken  and  spread  upon  the  bleach-ffreen  for  tour,  six,  or 
eight  days,  according  as  the  routine  of  business  calls  for  the  returnV  the  cloth,  in  order 
to  undergo  further  operations. 

A  parcel  of  goods  consists  of  360  pieces  of  those  linens  which  are  called  Britannias. 
li.ach  piece  is  35  yards  long ;  and  they  weigh,  on  an  average,  10  lbs.  each  :  the  weight  of 
parcel  is,  in  consequence,  about  3600  lbs.  avoirdupois  weight.    The  linens  are  first 
washed,  and  then  steeped  in  waste  alkaline  ley,  as  formerly  described  under  these  pro- 
cesses; they  then  undergo  the  following  operations  :— 

1st,    Bucked  with  60  lbs.  pearl-ashes,  washed,  exposed  on  the  field. 
2d,     Ditto  80  ditto  ditto      ditto  ditto. 

3d,     Ditto  90  potashes        ditto      ditto  ditto. 

4th,   Ditto  80  ditto  ditto      ditto  ditto. 


198 


BLEACHING. 


BLEACHING. 


199 


If" 


\l 


m 


5th,  Bucked  with  80  lbs.  pearl-ashes,  washed,  exposed  on  the  field. 
6th,  Ditto  50  ditto  ditto        ditto  ditto. 

7th,  Ditto  70  ditto  ditto        ditto  ditto. 

8th,  Ditto  70  ditto  ditto        ditto  ditto. 

9th,  Soured  one  night  in  dilute  sulphuric  acid,  washed. 
lOlh,  Bucked  with  50  lbs.  pearl-ashes,  washed,  exposed  on  the  field. 
11th,  Immersed  in  the  chloride  of  potash  or  lime  12  hours. 
12th,  Boiled  with  30  lbs.  pearl-ashes,  washed,  exposed  on  the  field, 
13th,  Ditto  30  ditto  ditto        ditto  ditto. 

14th,  Soured,  washed. 
The  linens  are  then  taken  to  the  rubbing-board,  and  well  rubbed  with  a  strong  lather 
of  black  soap,  after  which  they  are  well  washed  in  pure  spring  water.  At  this  period 
they  are  carefully  examined,  and  those  which  are  fully  bleached  are  laid  aside  to  be 
blued,  and  made  up  for  the  market;  while  those  which  are  not  fully  white  are  returned 
to  be  boiled,  and  steeped  in  the  chloride  of  lime  or  potash ;  then  soured,  until  iher  are 
fully  white. 

By  the  above  process,  690  lbs.  weight  of  alkali  is  taken  to  bleach  360  pieces  of  linen, 
each  piece  consistmg  of  35  yards  in  length;  so  that  the  expenditure  of  alkali  would  be 
somewhat  less  than  2  lbs.  for  each  piece,  were  it  not  that  some  parts  of  the  linens  are 
not  fully  whitened,  as  above  noted.  Two  pounds  of  alkali  may  therefore  be  staled  as  the 
average  quantity  employed  for  bleaching  each  piece  of  goods. 

The  method  of  bleaching  linens  in  Ireland  is'similar  to  the  foregoing ;  any  alteration  in 
the  process  depending  upon  the  judgment  of  the  bleacher  in  increasrag  or  diminishing  the 
quantity  of  alkali  used.  But  it  is  common,  at  most  bleach-fields,  to  steep  the  linens  in  the 
chloride  of  lime  or  potash  at  an  early  stage  of  the  process,  or  after  the  goods  have  under- 
gone the  fifth  or  sixth  operation  of  bucking.  By  this  means  those  parts  of  the  flax  which 
are  most  difficult  to  bleach  are  more  easily  acted  upon  by  the  alkali ;  and,  as  before  noticed, 
souring  early  in  very  dilute  sulphuric  acid,  assists  greatly  in  forwarding  the  whitening  of 
the  linens.  Mr.  Grimshaw,  calico-printer,  near  Belfast,  was  the  first  who  recommended 
early  souring,  which  has  since  been  very  generally  adopted. 

The  bleaching  of  Silk— Silk  in  its  raw  state,  as  spun  by  the  worm,  is  either  white  or 
yellow  of  various  shades,  and  is  covered  with  a  varnish,  which  gives  it  stiffness  and  a 
degree  of  elasticity.  For  the  greater  number  of  purposes  to  which  silk  is  applied,  it 
must  be  deprived  of  this  native  covering,  which  was  long  considered  to  be  a  sort  of  gum. 
The  operation  by  which  this  coloring  matter  is  removed  is  called  scouring,  cleansing, 
or  boiling.  A  great  many  different  processes  have  been  proposed  for  freein?  the  silk 
fibres  from  all  foreign  impurities,  and  for  giving  it  the  utmost  whiteness,  lustre,  and 
pliancy;  but  none  of  the  new  plans  has  superseded,  with  any  advantage,  the  one  prac- 
tised of  old,  which  consists  essentially  in  steeping  the  silk  in  a  warm  solution  of  soap;  a 
circumstance  placed  beyond  all  doubt  by  the  interesting  experiments  of  M.  Roard. 
The  alkalis,  or  alkaline  salts,  act  in  a  marked  manner  upon  the  varnish  of  silk,  and  eflfect 
its  complete  solution ;  the  prolonged  agency  of  boilinsr  water,  alone  answers  the  same 
purpose ;  but  nothing  agrees  so  well  with  the  nature  of  silk,  and  preserves  its  brilliancy 
and  suppleness  so  perfectly,  as  a  rapid  boil  with  soap-water.  It  would  appear,  however, 
that  the  Chinese  do  not  employ  this  method,  but  something  that  is  preferable.  Probably 
the  superior  beauty  of  their  white  silk  may  be  owing  to  the  superiority  of  the  raw  ma- 
terial. 

The  most  ancient  method  of  scouring  silk  consists  of  three  operations.  For  the  first, 
or  theungumming,  thirty  per  cent,  of  soap  is  first  of  all  dissolved  in  clean  river  water  by 
a  boilmg  heat ;  then  the  temperature  is  lowered  by  the  addition  of  a  little  cold  water, 
by  withdrawmg  the  fire,  or  at  least  by  damping  it.  The  hanks  of  silk,  suspended 
upon  horizontal  poles  over  the  boiler,  are  now  plunged  into  the  soapy  solution,  kept  at 
a  heat  somewhat  under  ebullition,  which  is  an  essential  point;  for  if  hotter,  the  soap 
would  attack  the  substance  of  the  silk,  and  not  only  dissolve  a  portion  of  it,  but  deprive 
the  whole  of  its  lustre.  The  portions  of  the  hanks  plunged  in  the  bath  get  scoured  by 
degrees ;  the  varnish  and  the  coloring  matter  come  away,  and  the  silk  assumes  its  proper 
whiteness  and  pliancy.  Whenever  this  point  is  attained,  the  hanks  are  turned  round  upon 
the  poles,  so  that  the  portion  formerly  in  the  air  may  be  also  subjected  to  the  bath.  As 
soon  as  the  whole  is  completely  ungummed,  they  are  taken  out,  wrung  by  the  peg,  and 
shaken  out ;  after  which,  the  next  step,  called  the  boily  is  commenced.  Into  bags  of  coarse 
canvass,  called  pockets,  about  25  lbs.  or  35  lbs.  of  ungummed  silk  are  enclosed,  and  put 
into  a  similar  bath  with  the  preceding,  but  with  a  smaller  proportion  of  soap,  which  mar 
therefore  be  raised  to  the  boihng  point  without  any  danger  of  destroying  the  silk.  The 
ebullition  is  to  be  kept  up  for  an  hour  and  a  half,  during  which  time  the  bags  must  be 
frequently  stirred,  lest  those  near  the  bottom  should  suffer  an  undue  degree  of  heat.  The 
silk  experiences  in  these  two  operations  a  loss  of  about  25  per  cent,  of  its  weight. 

The  third  and  last  scouring  operation  is  intended  to  give  the  silk  a  slight  tingej  which 


renders  the  white  more  agreeable,  and  better  adapted  to  its  various  nses  in  trade.  la 
this  way  we  distinguish  the  China  white,  which  has  a  faint  cast  of  red,  the  silver  white, 
the  azure  white,  and  the  thread  white.  To  produce  these  diflferent  shades,  we  begin  by 
preparing  a  soap-water  so  strong  as  to  lather  by  agitation ;  we  then  add  to  it,  for  the 
China  white,  a  little  annotto,  mixing  it  carefully  in ;  and  then  passing  the  silk  properly- 
through  it,  till  it  has  acquired  the  wished  for  tint.  As  to  the  other  shades,  we  need  only 
azure  them  more  or  less  with  a  fine  indigo,  which  has  been  previously  washed  severid 
times  in  hot  water,  and  reduced  to  powder  in  a  mortar.  It  is  then  difl"used  through 
boiling  water,  allowed  to  settle  for  a  few  minutes,  and  the  supernatant  liquid,  which 
contains  only  the  finer  particles,  is  added  to  the  soap  bath  in  such  proportion  as  may  be 
requisite.  The  silk,  on  being  taken  out  of  this  bath,  must  be  wrung  well,  and  stretched 
upon  perches  to  dry ;  after  which  it  is  introduced  into  the  sulphuring  chamber,  if  it  is 
to  be  made  use  of  in  the  white  state.  At  Lyons,  however,  no  soap  is  employed  at  the 
third  operation :  after  the  boU,  the  silk  is  washed,  sulphured,  and  azured,  by  passing 
through  veiy  clear  river  water  properly  blued. 

The  silks  intended  for  the  manufacture  of  blonds  and  gauzes  are  not  subjected  to  the 
ordinary  scouring  process,  because  it  is  essential,  in  these  cases,  for  them  to  preserve  their 
natural  stiffness.  We  must  therefore  select  the  raw  silk  of  China,  or  the  whitest  raw 
silks  of  other  countries ;  steep  them,  rinse  them  in  a  bath  of  pure  water,  or  ia  one  con- 
taining a  little  soap ;  wring  them,  expose  them  to  the  vapor  of  sulphur,  and  then  pass 
them  through  the  azure  water.     Sometimes  this  process  is  repeated. 

Before  the  memoir  of  M.  Roard  appeared,  extremely  vague  ideas  were  entertained 
about  the  composition  of  the  native  varnish  of  silk.  He  has  shown  that  this  substance, 
so  far  from  being  of  a  gummy  nature,  as  had  been  believed,  may  be  rather  compared  to 
bees'  wax,  with  a  species  of  oil,  and  a  coloring  matter,  which  exists  only  in  raw  silks. 
It  is  contained  in  them  to  the  amount  of  from  23  to  24  per  cent.,  and  forms  the  portion 
of  weight  which  is  lost  in  the  ungumming.  It  possesses,  however,  some  of  the  properties 
of  vegetable  gums,  though  it  differs  essentially  as  to  others.  In  a  dry  mass,  it  is  friable 
and  has  a  vitreous  fracture;  it  is  soluble  in  water,  and  affords  a  solution  which  lathers 
like  soap;  but  when  thrown  upon  burning  coals,  it  does  not  soften  like  gum,  but  bums 
with  the  exhalation  of  a  fetid  odor.  Its  solution,  when  left  exposed  to  the  open  air,  at 
first  of  a  golden  yellow,  becomes  soon  greenish,  and  ere  long  putrefies,  as  a  solution  of 
animal  matter  would  do  'n  similar  circumstances.  M.  Roard  assures  us  that  the  city  of 
Lyons  alone  could  furnish  several  thousand  quintals  of  this  substance  per  annum,  were  it 
applicable  to  any  useful  purpose. 

The  yellow  varnish  is  of  a  resinous  nature,  altogether  insoluble  in  water,  very  soluble 
in  alcohol,  and  contains  a  little  volatile  oil,  which  gives  it  a  rank  smell.  The  color  of 
this  resin  is  easily  dissipated,  either  by  exposure  to  the  sun  or  by  the  action  of  chlorine  : 
it  forms  about  one  fifty-fifth  of  its  weight. 

Bees'  wax  exists  also  in  all  the  sorts  of  sUk,  even  in  that  of  China ;  but  the  whiter  the 
filaments,  the  less  wax  do  they  contain. 

M.  Roard  has  observed  that,  if  the  silk  be  exposed  to  the  soap  baths  for  some  time  after 
it  has  been  stripped  of  its  foreign  matters,  it  begins  to  lose  body,  and  has  its  valuable 
qualities  impaired.  It  becomes  dull,  stiff,  and  colored  in  consequence  of  the  solution 
more  or  less  considerable  of  its  substance  ;  a  solution  which  takes  place  in  all  liquids, 
and  even  in  boiling  water.  It  is  for  this  reason  that  silks  cannot  be  alumed  with  heat ; 
and  that  they  lose  some  of  their  lustre  in  being  dyed  brown,  a  color  which  requires  a 
boiling  hot  bath.  The  best  mode,  therefore,  of  avoiding  these  inconveniences,  is  to  boil 
the  silks  in  the  soap- bath  no  longer  than  is  absolutely  necessary  for  the  scouring  process, 
and  to  expose  them  in  the  various  dyeing  operations  to  as  moderate  temperature  as  may 
be  requisite  to  communicate  the  color.  When  silks  are  to  be  dyed,  much  less  soap 
shoulc*  be  used  in  the  cleansing,  and  very  little  for  the  dark  colors.  According  to  M. 
Roard,  raw  silks,  white  or  yellow,  may  be  completely  scoured  in  one  hour,  with  15  lbs. 
of  water  for  one  of  silk,  and  a  suitable  proportion  of  soap.  The  soap  and  the  silk  should 
be  put  into  the  bath  half  an  hour  before  its  ebullition,  and  the  latter  should  be  turned 
about  frequently.  The  dull  silks,  in  which  the  varnish  has  already  undergone  some  al- 
teration, never  acquire  a  fine  white  until  they  are  exposed  to  sulphureous  acid  gas.  Ex- 
posure to  light  has  also  a  very  good  effect  in  whitening  silks,  and  is  had  recourse  to,  it  b 
said,  with  advantage  by  the  Chinese. 

Carbonate  of  soda  has  been  proposed  to  be  used  instead  of  soap  in  scouring  silk, 
but  it  has  never  come  into  use.  The  Abbe  Collomb,  in  1785,  scoured  silk  by  eight 
hours-  boiling  in  simple  water,  and  he  found  the  silks  bleached  in  this  way  to  be 
stronger  than  by  soap,  but  they  are  not  nearly  so  white.  A  patent  has  been  taken  out 
in  England  for  bleaching  them  by  steam,  of  which  an  account  will  be  found  under  the 
article  Silk. 

It  appears  that  the  Chinese  do  not  use  soap  in  producing  those  fine  white  sUks  which 
are  imported  into  Europe.    Michel  de  Grubbens,  who  resided  long  at  Canton,  saw  and 


200 


BLEACHING. 


BLEACHING  OP  PAPER. 


201 


|4    . 
Il 

u  ■ 


U   f 


^t:\ 


f:      } 


I 


^ctise-l  himself  .the  operation  there,  which  he  published  in  the  Memoirs  of  th«. 
Academy  of  Stockholm  in  1803.  It  consists  in  preparing  the  silk  wiT  a  species  of 
White  beans,  smaUer  than  the  Turkey  beans,  with  some  wheat  flour,  common  S^lt  and 

form  this  vegetable  bath.  The  beans  must  be  previously  washed.  It  is  difficult  to  dis- 
cover what  chemical  action  can  occur  between  that  decoction  and  the  varnish  of  raw 
Silk ;  possibly  some  acid  may  be  developed,  which  may  soften  the  gummy  matter  and 
facilitate  Its  separation.  s"^^^j^  mauer,  ana 

Baume  contrived  a  process  which  does  not  appear  to  have  received  the  sanction  of 
experience,  but  which  may  put  us  in  the  right  way.     He  macerates  the  yellow  raw  silk 

ln-5  °^?.7  ^J'^rr  ";'  ^  •\^'?-  ^''  ^.^^^^  ^^^  «°^  thirty-second  part  of  pure  muriaUc 
^  ?•  i  rf  i  f^'^y:flS^^^ouTs,  It  is  as  white  as  possible,  and  the  more  so,  the 
better  the  quality  of  the  silk.  The  loss  which  it  sufl^ers  in  this  menstruum  is  only  one 
fortieth ;  showmg  that  nothing  but  the  coloring  matter  is  abstracted.  The  expense  of 
Uus  menstruum  is  the  great  obstacle  to  Baume's  process.  The  alcohol,  however!  might 
dTstiUatron!""^  ^''^'  ""^^'""^  recovered,  by  saturating  the  acid  with  chalk,  and  fe- 

.„ifir'^'"^y  W-oo/.-Wool  like  the  preceding  fibrous  matter,  is  covered  with  a  pe- 
cuhar  varnish  which  impairs  its  qualities,  and  prevents  it  from  being  employed  in  5^ 
raw  state  for  the  purposes  to  which  it  is  weU  adapted  when  it  is  scoured.  The  English 
give  the  name  yoZfc  and  the  French  suint,  to  that  native  coat :  it  is  a  fatty  unctuous  mat 
if 'thlth  ""^T'^^^^'v'  apparently  has  its  chief  origin  in  the  cutaneous  perspiLTon 
of  the  sheep;  but  which,  by  the  agency  of  external  bodies,  may  have  undergone  ^me 
^n  tf/t  7h  '  J-'^^  '''  constitution.  It  results  from  the  'experiments  of  M^  Vau^^e! 
Ijn,  that  the  2/o/fe  is  composed  of  several  substances;  namely,  1,  a  soap  with  basis  of 

n^  a^h'  "".  n?  """"''T''  ?•'  ^T'^^  P"^^  «^  ''-^  2,  of  a  notable  quantityI?acSe  of 

^L:~s:L::lTei;:'^^^^  ^^^^-^^  '--  ^^-L  several  otheT^ccS 
The  proportion  of  yolk  is  variable  in  diflerent  kinds  of  wool,  but  in  general  it  is  more 

The  yolk,  on  account  of  its  soapy  nature,  dissolves  readily  in  water  with  tbp  pt 
ception  of  a  little  free  fatty  matter,  which  easily  separates  fJom  tie  fikments  andrl' 
mams  floating  m  the  liquor.  It  would  thence  appear  sufficient  to  expo^'heVo^fs  ^ 
simple  washing  in  a  stream  of  water;  yet  experience  shows  that  this  method  nrvTr  an- 
swers so  well  as  that  usually  adopted,  which  consists  in  steeping  the  woo  fS  some  time 
n  simple  warm  water,  or  in  warm  water  mixed  with  a  fourth  of  stale  urine'    From"? 

LLTk''  't  '"'T':-  ^''  '"i?"'^"*  ^"  '^''  '^''>  i^  ^^  ^^^'  the  bath  as  warm  as  tie 
hand  can  bear  it  and  stir  it  well  with  a  rod.    At  the  end  of  this  time  the  wool  may  be 

Ittrear^/wat'er        ' '  '"  "^''"^  ^"  ^"^^^  ^'^''''  ^^  ""'^'^  '^  ^«  '^^^'^'^'y  ^-"'d  m 
It  is  generally  supposed  that   putrid  urine  acts  on  the  wool  by  the  ammonia  which  it 

Z^CT:  ^"t^  V^^'  t''^;"^''  !^  ^^P^^^^y  '^^  ^^"^^"^^^  «^  ^he  fatty  matter  not  cTmbted 
with  the  potash  M.  Vauquclin  is  not  of  this  opinion,  because  he  found  that  wool  sTeen^ 
ZZ  T:  ^'!\'^^-  V^'^'^''^^  «"d  quick  lime,  is  not  better  scoured  than  an«i3quant^!v 
nfitTrfilr'-'^  ""-^l"!!''  ^^T'.  ^'  ^^«  ^^"^«  ^^  t«  ^°"^1»J«  that  the  gTd  effect"  of 
t^l^l  ,1.  ""T  T^^-  ^  ^'"'^^  to  anything  else  besides  the  ammonia,  and  probab  y  to 
the  urea.  Fresh  urine  contains  a  free  acid,  which,  by  decomposing  the  pot^h  Zal  of 
the  yolk,  counteracts  the  scouring  operation.  *  lue  poiasn  soap  ol 

If  wools  are  better  scoured  in  a  small  quantity  of  water  than  in  a  great  stream  wp 
can  conceive  that  ths  circumstance  must  depend  upon  the  nature  of  the  ydkfXh  Tn 
a  concentrated  solution,  acts  like  a  saponaceous  compound,  and  thus  conStls  to  re 

^Zon"^nZ\"''\^^'''''  r'l'^  ^^'^^^  ^«  '^'  ^'^^^^ts!  It  should  ds^  be  observ^ 
that  too  long  a  continuance  of  the  wool  in  the  yolk  water,  hurts  its  quality  very  m7ch 
by  weakening  its  cohesion,  causing  the  filaments  to  swell,  and  even  to  split!  It  i^said 
then  to  have  lost  its  r^m.  Another  circumstance  in  the  scouring  of  woo  that  'hou  d 
^ways  be  attended  to,  is  never  to  work  the  filaments  together  to  such  a  deg  ee  as  toT- 
^.11  l^Z  ^1k""'  ^"V"  «?itatingwe  must  merely  push  them  slowlv  round  in  the 
nS  spin  wX  ^'^  ^        "'  '^'  ^""'-     ^^^'^  ''  ^'  ^  ^^^^^^'  ^t  would    neither  card 

As  the  heat  of  boiling  water  is  apt  to  decomiwse  woollen  fibres,  we  should  be  careful 
^' u'ooT'  '^  ^«"Pf5^t"^^  «f  the  scouring  bath  to  near  this  point,  nor,  in  fact, Tex 
eeed  140^  F.     Some  authors  recommend  the  use  of  alkaline  or  Lap;  baths  for  scourfna 
wl     'i^'^^^'^T-  P^*?P^^  **°  r^  ^^^^^te  from  the  method  above  described.  ^ 

Wiicn  the  washing  is  completed,  all  the  wool  which  is  to  be  sent  white  into  the  mar- 


ket,  must  be  exposed  to  the  action  of  sulphurous  acid,  either  in  a  liquid  or  a  gaseous 
state.  In  the  latter  case,  sulphur  is  burned  in  a  close  chamber,  i»  which  the  wools  are 
hung  up  or  spread  out;  in  the  former,  the  wools  are  plunged  into  water,  moderately 
impregnated  with  the  acid.  (See  Sulphuring.)  Exposure  on  the  grass  may  also  con- 
tribute to  the  bleaching  of  wool.  Some  fraudulent  dealers  are  accused  of  dipping  wools 
in  butter-milk,  or  chalk  and  water,  in  order  to  whiten  them  and  increase  their  weight. 

Wool  is  sometimes  whitened  in  the  fleece,  and  sometimes  in  the  state  of  yarn ;  the 
latter  affording  the  best  means  of  operating.  It  has  been  observed  that  the  wool  cut 
from  certain  parts  of  the  sheep,  especially  from  the  groins,  never  bleaches  well. 

After  sulphuring,  the  wool  has  a  harsh  crispy  feel,  which  may  be  removed  by  a  weak 
soap  bath.  To  this  also  the  wool  comber  has  recourse  when  he  wishes  to  cleanse  and 
whiten  his  wools  to  the  utmost.  He  generally  uses  a  soft  or  potash  soap,  and  after  the 
wool  is  well  soaked  in  the  warm  soap  bath,  with  gentle  pressure  he  wrings  it  well  with 
the  help  of  a  hook,  fixed  at  the  end  of  his  washing  tub,  and  hangs  it  up  to  dry. 

Bleaching  of  raga,  and  paste  for  paper  making.  —  After  the  rags  are  reduced  to  what  is 
called  half  stuff",  they  should  have  the  greater  part  of  the  floating  water  run  off",  leaving 
just  enough  to  form  a  stir-about  mass.  Into  this  a  clear  solution  of  chloride  of  lime 
should  be  poured,  of  such  a  strength  as  is  suited  to  the  color  of  the  rags,  which  should 
have  been  previously  sorted;  and  the  engine  is  kept  going  so  as  to  churn  the  rags 
with  the  bleaching  agent.  After  an  hour,  the  water  may  be  returned  upon  the  engine, 
and  the  washing  of  the  paper  resumed.  From  two  to  four  pounds  of  good  chloride  of 
lime  are  reckoned  sufficient  to  bleach  one  hundred  weight  of  rags. 

When  the  rags  consist  of  dyed  or  printed  cottons,  after  being  well  washed  and  re- 
duced to  half  stuff,  they  should  be  put  into  a  large  cask  or  butt,  supported  horizontally 
by  iron  axles  upon  cradle  bearings,  so  that  it  may  be  made  to  revolve  like  a  barrel- 
churn.  For  each  hundred  weight  of  the  colored  rags,  take  a  solution  containing  from 
four  to  eight  pounds  of  chloride  of  lime ;  add  it  to  the  liquid  mixture  in  the  butt  along 
with  half  a  pound  of  sulphuric  acid  for  every  pound  of  the  chloride ;  and  after  inserting 
the  bung,  or  rather  the  square  valve,  set  the  vessel  in  slow  revolution  backwards  and  for- 
wards. In  a  short  time  the  rags  will  be  colorless.  The  rags  and  paper  paste  ought 
to  be  very  well  washed,  to  expel  all  the  chlorine,  and  perhaps  a  little  muriatic  acid 
might  be  used  with  advantage  to  dissolve  out  all  the  calcareous  matter,  a  portion  of 
which  is  apt  to  remain  in  the  paper,  and  to  operate  injuriously  upon  both  the  pens  and 
the  ink.  Some  of  the  French  paper  manufacturers  bleach  the  paste  with  chlorine  gas. 
Paper  prepare!  from  such  paste,  well  washed,  is  not  apt  to  give  a  brown  tint  to  maps, as 
that  carelfsslv  bleached  with  chloride  of  lime  is  known  to  do.  .     .■,      ,    .j      /• 

BLEACHING  OF  PAPER.  The  following  are  the  proportions  of  Uqmd  chlonde  of 
lime,  at  10°  of  Gay  Lussac's  Chloromctre,  employed  for  the  different  sorts  of  rags,  con- 
sisting of  two  piles,  or  200  poundl  French. 


Cotton. 
No.  1. 

2. 

3. 

4. 

6. 

6. 


Fine  cotton  rags 
Clean  calicoes 

White  dirty  calico,  coarse  cotton 
Coarse  cotton 
Grey,  No.  1  - 

No.  2  - 

Saxon  gray 


No.  2 


Pale  white  and  half-white  shades 

Saxon  blues ;  pale  pink,  dark  blue,  velvet    - 


litres. 
10 
12 
14 
16 
18 
20 
22 
24 
26 
28 
32 


It  is  considered  to  be  much  better  to  bleach  the  fine  rags  with  liquid  chloride  of  lime, 
and  not  with  chlorine  gas,  because  they  are  less  injured  by  the  former,  and  afford  a 
paper  of  more  nerve,  less  apt  to  break,  and  more  easily  sized.  But  the  coarse  or  gray 
rags  are  much  more  economically  bleached  with  the  gaseous  chlorine,  without  any  risk 
of  weakening  the  fibre  too  much.  Bleaching  by  the  gas  is  performed  always  upon  the 
sorted  rags,  which  have  been  boiled  in  an  alkaline  ley,  and  torn  into  the  fibrous  state. 
They  are  subjected  to  the  press,  in  order  to  form  them  into  damp  cakes,  which  are  bro- 
ken in  pieces  and  placed  in  large  rectangular  wooden  cisterns.  The  chlorine  gas  is  in- 
troduced by  labes  in  the  lid  of  the  cistern,  which  falls  down  by  its  superior  gravity, 
acting  always  more  strongly  upon  the  ra  rs  at  the  bottom  than  those  above. 

When  the  chlorine,  disengaged  from  150  kilogrammes  (330  lbs.)  of  manganese  and 
500  kilos,  of  muriatic  acid,  is  made  to  act  upon  2,500  kilos,  of  the  stuff  (supposed  dry), 
it  will  have  completed  its  effect  in  the  course  of  a  few  hours.  Thequanlity  of  gaseous 
chlorine  is  equal  to  what  is  contained  in  the  quantity  of  chloride  of  lime  requisite  to  pro- 
duce a  like  bleaching  result.     The  bleached  stuff  should  be  forthwith  carefully  washed. 


n 


n 


it 


*  »-:! 


202 


BLOCK  MANUFACTURE. 


to  remove  all  the  muriatic  acid  produced  from  the  chlorine ;  for  if  any  of  this  remain 
in  the  paper,  it  destwys  lithographic  stones  and  weakens  ooramon  ink. 

BLENDE.  (Fr.  and  Germ.)  Sulphuret  of  zinc,  so  named  from  the  German  blendeii, 
to  dazzle,  on  account  of  its  glistening  aspect.  It  is  called  black  jack  from  its  usual 
color.  Its  lustre  is  pearly  adamantine.  Spec,  gravity  from  3*7  to  4*2.  It  contains 
frequently  iron,  copper,  arsenic,  cadmium  and  silver,  all  associated  with  sulphur.  It  is 
worked  up  partly  into  metallic  zinc,  and  partly  into  the  sulphate  of  zinc,  or  white 
vitriol  It  consists  of  66 "7 2  zinc,  and  33 "28  sulphur  ;  being  nearly  by  weight  as  two 
to  one.     See  Zinc. 

BLOCK  MANUFACTURE.  Though  the  making  of  ships'  blocks  belongs  rather 
to  a  dictionary  of  engineering  than  of  manufactures,  it  may  be  expected  that  I  should 
give  some  account  of  the  automatic  machinery  for  making  blocks,  so  admirably  devised 
and  mounted  by  M.  L  Brunei  Esq.,  for  the  British  navy,  in  the  dockyard  of  Portsmouth. 

The  series  of  machines  and  operations  are  as  follows : — 

1.  77ie  straight  cross  cutting  saw. — The  log  is  placed  horizontally  on  a  very  low 
bench,  which  is  continued  through  the  window  of  the  mill  into  the  yard.  The  saw  is 
exactly  over  the  place  where  the  log  is  to  be  divided.  It  is  let  down,  and  suffered  to  rest 
with  its  teeth  upon  the  log,  the  back  still  being  in  the  cleft  of  the  guide.  The  crank 
being  set  in  motion,  the  saw  reciprocates  backwards  and  forwards  with  exactly  the  same 
motion  as  if  worked  by  a  carpenter,  and  quickly  cuts  through  the  tree.  When  it  first 
begins  to  cut^  its  back  is  in  the  cleft  in  the  guide,  and  this  causes  it  to  move  in  a  straight 
line;  but  before  it  gets  out  of  the  guide,  it  is  so  deep  in  the  wood  as  to  guide  itself ;  for 
in  cutting  across  the  grain  of  the  wood,  it  has  no  tendency  to  be  diverted  from  its  true 
line  by  the  irregular  grain.  When  the  saw  has  descended  through  the  tree,  its  handle 
is  caught  in  a  fixed  stop,  to  prevent  its  cutting  the  bench.  The  machine  is  thrown 
out  of  gear,  the  attendant  lifts  up  the  saw  by  a  rope,  removes  the  block  cut  off,  and 
advances  the  tree  to  receive  a  fresh  cut. 

2.  The  circular  cross  cutting  saw. — ^This  saw  possesses  universal  motion ;  but  the  axis 
is  always  parallel  to  itself,  and  the  saw  in  the  same  plane-  It  can  be  readily  raised  or 
lowered,  by  inclining  the  upper  frame  on  its  axis ;  and  to  move  it  sidewise,  the  saw 
frame  must  swing  sidewise  on  its  joints,  which  connect  it  with  the  upper  frame.  These 
movements  are  effected  by  two  winches,  each  furnished  with  a  pair  of  equal  pinions, 
working  a  pair  of  racks  fixed  upon  two  long  poles.  The  spindles  of  these  winches  are 
fixed  in  two  vertical  posts,  which  support  the  axis  of  the  upper  frame.  One  of  these  pairs 
of  poles  is  jointed  to  the  extreme  end  of  the  upper  frame ;  therefore  by  turning  the  han- 
dle belonging  to  them,  the  frame  and  saw  is  elevated  or  depressed  ;  in  like  manner,  the 
other  pair  is  attached  to  the  lower  part  of  the  saw  frame,  so  that  the  saw  can  be  moved 
sidewise  by  means  of  their  handles,  which  then  swing  the  saw  from  its  vertical  position. 

These  two  handles  give  the  attendant  a  complete  command  of  the  saw,  which  we 
suppose  to  be  in  rapid  motion,  the  tree  being  brought  forward  and  properly  fixed.  By 
one  handle,  he  draws  the  saw  against  one  side  of  the  tree,  which  is  thus  cut  into  (per- 
haps half  through);  now,  by  the  other  handle,  he  raises  the  saw  up,  and  by  the  first- 
mentioned  handle  he  draws  it  across  the  top  of  the  tree,  and  cuts  it  half  through  from 
the  upper  side ;  he  then  depresses  the  saw  and  cuts  half  through  from  the  next  side  ; 
and  lastly  a  trifling  cut  of  the  saw,  at  the  lower  side,  completely  divides  the  tree, 
which  is  then  advanced  to  take  another  cut. 

The  great  reciprocating  saw  is  on  the  same  principle  as  the  saw  mill  in  common  use 
in  America. 

3.  The  circular  ripping  saw  is  a  thin  circular  plata  of  steel,  with  teeth  similar  to  those 
of  a  pit  saw,  formed  in  its  periphery.  It  is  fixed  to  a  spindle  placed  horizontally,  at  a 
small  distance  beneath  the  surface  of  a  bench  or  table,  so  that  the  saw  projects  through 
a  crevice  a  few  inches  above  the  bench.  The  spindle  being  supported  in  proper  collars, 
has  a  rapid  rotatory  motion  communicated  to  it  by  a  pulley  on  the  opposite  end,  round 
which  an  endless  strap  is  passed  from  a  drum  placed  overhead  in  the  mill.  The  block 
cut  by  the  preceding  machine  from  the  end  of  the  tree,  is  placed  with  one  of  the  sides 
flat  upon  the  bench,  and  thus  slides  forward  against  the  revolving  saw  which  cuts  the 
wood  with  a  rapidity  incredible  to  any  one  who  has  not  seen  these  or  similar  machines. 

4.  Boring  machine.— The  blocks,  prepared  by  the  foregoing  saws,  are  placed  in  the 
machine  represented  in^^.  144.  This  machine  has  an  iron  frame,  a  a,  with  three  legs, 
beneath  which  the  block  is  introduced,  and  the  screw  near  b  being  forced  down  upon  it, 
confines  it  precisely  in  the  proper  spot  to  receive  the  borers  d  and  e.  This  spot  is  de- 
termined by  a  piece  of  metal  fixed  perpendicularly  just  beneath  the  point  of  the  borer  e, 
shown  separately  on  the  ground  at  x  ;  this  piece  of  metal  adjusts  the  position  for  the 
borer  d,  and  its  height  is  regulated  by  resting  on  the  head  of  the  screw  x.  which  fastens 
the  piece  x  down  to  the  frame.  The  sides  of  the  block  are  kept  in  a  parallel  position,  by 
being  applied  against  the  heads  of  three  screws  tapped  into  the  double  leg  of  the  frame 
A.    The  borer  d  is  adapted  to  bore  the  hole  for  the  centre  pin  in  a  direction  exactly  per- 


BLOCK  MANUFACTURE. 


203 


pendicular  to  the  surface  re^^^^^l^^^^^^  ^S^^rtl^I^^col^^^^^^^^ 
holes  for  the  commencement  of  t^^/^^^^^^./^''^^,  ^  l^^n  mandrels,  mounted  in  frames 
the  same  manner ;  they  ««•  V*^"^^^^-!  ^T^^^^StS  wTh  sUders  upin  the  angular  edges 
Bimilar  to  a  lathe.    These  frames  g  ^J^^  "'"^. XVeTs  screwed  fast  to  the  frame;  the 
of  the  flat  broad  bars,  i  and  k      The  ^^^^^  «/^^^^fjf^ '.'.^^^^^  at  L  l,  beneath  the 

Utter  is  fixed  upon  a  frame  of  its  «-^>.fJ  ^"^V.'ifb^^^^^^^^^^^^  within  certain 

principal  frame  of  the  °ia<^^.'"^:.«.^y„7''TrnV     These  limits  are  determined  by  two 
limits  so  as  to  bore  holes  '^  ^^'^^Z'^'''Zn<roni^^  They 

screws,  one  of  which  is  seen  at  a  ,•  the  o  her,  bein    on  ine  opp  .  'ejecting  piece  of 

fre  tapped  through  fixed  PJJ-  ^f  "of  ^he  ^er  t  ':^^^^^^^ 

metal,  from  the  under  side  of  ^^^  slider  ko.  i^«^         'j,     both  borers  are  brought  up 

"f  ""rL*™X""r;«d.m  is  a  beautiful  piece,  of  mechanism,  but  too  compUcaled  for 
des^ripciou  within  the  limits  Pr«cril^  to  th'sa^^^^^^^^  ,  ,„„,  i  ^. 

6.  The  comer  saw,  fig-  14S,  consols  oi  »  """'      >  mandrel  and  its  frame  being 

ing  a  circular  saw  .  »<»» 'J' ^'^  jMit '«ot -quir^^^^^^ 
exactly  similar  to  those  at  G  »°^  "'j^f- '7/ °°7  "   ^Agj  ^,    This  frame  is  screwed 

ll"2^f  ^e tmT.'  rpV^^^^^^^^^ ^- 
l-Z^^X^:'^^:^-'^^^^  end  Uept  up'  .0  its  ^iUo. 
by  the  other  part  of  the  bench  d  p.  ^^  ^^^^  ^ff  jj. 

By  sUding  the  block  along  this  bench,  it  ^»  *Pf  f Vr  .he  sh^Mn-  engine.  All  the 
angles,  as  is  evident  from  the  figure,  and  prepares  t  ^^J^lJ^  f  X%o  ?he  trough,  or 
four  ^gles  are  cut  off  in  succession,  by  applying  its  dfere^t  sides    «  i  g  ,^ 

eUlent  If  la^ng  ptct  of  w^  o?  different  thickness  against  the  plane  .  i>,  so  as  to 


y 


-  m»m*'1U>- 


I 


20i 


BLOCK  MANUFACTURE. 


BLOCK  MANUFACTURE. 


205 


from  large  than  from  smaU  blocks.     The 
Sken  [o  '°  '^'  ''"'"  °^  *=  ^«  »«^ 

^J;   ??u    *^^^"«^  7Wfff;i/7,e.-_A    great 
deal  of  the  apparent  complication  of  this 
%ure  arises  from  the  iron  cage,  which 
IS  provided  to  defend  the  workmen,  lest 
the  blocks,  which  are  revolving  in  the 
circles,   or    chuck,    with    an    Lmense 
velocity,  should  be  loosened  by  the  ac 
tion   of  the  tool,   and  fly  out  by  their 
centrifugal  force.     Without  this  provi- 
sion, the  consequences  of  such  an  acci- 
dent would  be  dreadful,  as    the   blocks 
would  be  projected  in  all  directions,  with 
an  inconceivable  force. 

8.  The  scoring  engine  receives  two 
blocks,  as  they  come  from  the  shaping 
engine,  and  forms  the  groove  round 
their  longest  diameters  for  the  reception 
of  their  ropes  or  straps,  as  represented 
m  the  two  snatch  blocks  and  double 
block,  under /g,.  144,  145. 

A,  B,  Jig.  146,  represent  the  above 
two  blocks,  each  held  between  twosmal' 
pillars  a  (the  other  piUar  is  hid  behind 
the  block),  fixed  in  a  strong  plate  d,  and 
pressed  against  the  pillars  by  a  screw  L 
_  which   acts  on  a  clamp  d.    Over  the 

tcrs,  E  E,  are  situated,  both  being  fixed  on  the  ^Jnl.-  *P^'\o^  circular  planes  or  cat- 
m  the  middle  of  it.     The  spinJle  is  fiUed  inTfrn^"''^^^'  "^^'"-^  ''  ^"^^^  ^^  »  P»"ey 
as  to  rise  and  fall  when  moved  by  a  handle  f     Th^hZI:  f^""^  ^"  "^"^^«  ^' '  ^^  ^ 
blocks ;  and  the  depth  to  which  they  can  cuUs  rl^ulat^  £  «  '  '"'^'"1  *^°^"  "P«"  ^^« 
screws  upon  the  plate  d,  between  the  block.     Tin!    .k^  ^  *  ''''^^^  ^^^P^  g»  filed  by 
ft,  fixed  to  the  frame  f,  and  enclos  n"  b^n^f  t   T-  *^'\'''^'  *  '^"'^^^^  P'^^e  of  mettU 
ters  to  traverse  the  whole  length  o^rheblocLth^^^^^^^^^  the  pulley      To  admit  the  cuU 
It)  is  sustained  between  the  points  of  two  cent; J^     ^ir  J"  ^°'  '^^^''  ^  ^^"^«  beneath 
tres.     The  frame  inclines  when  the  }  aire  L^^.r.     7'  f^  ''^"  ^^  ^>  «»  ^hese  cen- 
at  the  end  of  it,  counterbalancing  the  wei'h    oPthe'bLk^' ""i'  ^1  ^''''*  ^^^^  ^ ^'^^^'^ 
above  the  centre  on  which  they  mSve.     Sframe  l  ^  «!.«    '  ^"1  ^^^^  ?'  ^"  ^^^^^  ^^e 
to  balance  the  cutters,  &c.     The  cutters  rp«^n  '"  f^°  Pl^^l^ed  with  a  counterpoise 

edges.    Each  has  two  Notches  in  its  circTrnferercp  ^  1  "•,^^'!^'  ^^  ^'^''^  ^'^»»  ^°»«d 
chisels  are  fixed  by  screws,  to  prc^Lc    bev^^^^^^  ''^'V  ?"d  in  these  notches 

plane  iron  before  its  face.  '^         ^  "^"^  ""^  '^^  ^^^e^*  ^^  the  manner  of  a 

such  a  segment  of  each  as  wMl  in<,t  t^^  T'l,  ?'  "'"/"''  ™'  '"'»y>  '«»»«?  only 
taken  out  to  admit  the  cuttrio  olra.e  h«if  ^^1^'  *"■*  ""*  "^"^  ""•'«»  «he-  « 
blocks  into  this  machine  the  woX^^     between  them,  or  nearly  so.    In  putting  the 

daws  ofthe  clamps,  but  tak«r«?rha?,Kri'''^  ''?V'''^  PriWs  to  the  ends  of  he 
they  should  be:  he  then  takel  thTha„l  ^  and  hvT '■'^''" '«^'*«<^»  ">«  P'"»  «  than 
we  suppose  are  slandinj  siai)  do^Z,n\Zu  I  T'"  ^^  '=""^"  =  *:  ("'Wch 
pins  at  the  same  time,  till  the  desX  of^Jhe  l.^^?'  ''^P'««!"S  them  between  their 
on  the  shape  g.  He  now  tumsTe  s«ew^  6  6  .rfii'  ,T^?f  ."''  '•'"'  P'^«  *  '<'^«''? 
being  pat  in  motion  cut  the  scores,  Vh"h  will  be  ll„  v  .    "'k'  ',^''"-    ^he  cuttera 

»a:c2srrb!:cti,lrkt^r.ht^^^^^^ 

handle/,  they  wiU  cut  an'y  depth   '^^^'^^111,^71:^.^:^^^^^/'^^^^ 

By  this  means  one  quarter  of  the  scorp  i«  fm-mo/i    ♦!.      .1. 
blocks  together  half  l„d  in  this  m^nr  iZf.l^^%TJ ^Z  K-JK 


i* 


itself,  but  into  a  frame  seen  at  r  beneath  the  plate,  which  is  connected  with  it  by  a 
cenS-e  pin,  exactly  midway  between  the  two  blocks  A  b.  A  spring  catch,  the  end  of 
S  is  s^en  at  r,  confines  them  together ;  when  this  catch  is  pressed  back  the  plate  d 
Tan  be  turned  aboit  upon  its  centre  pin,  so  as  to  change  the  blocks,  end  for  end  and 
bring  the  unscored  qukrters  (».  e.  over  the  clamps)  beneath  the  cutters;  the  workman 
S-  the  handles  /  and  l,  one  in  each  hand,  and  pressing  them  down,  cute  out  the 
^ind  quarter  This  might  have  been  eflected  by  simply  lifting  up  the  handle  l  ;  bu 
in  that^se  the  cutter  would  have  struck  against  the  grain  of  the  wood  so  as  to  cut 
mier  rou-hly :  but  by  this  ingenious  device  of  reversmg  the  blocks,  it  always  cuts 
de^  and  sm(x,th,  in  the  direction  of  the  grain.  The  third  and  fourth  quarters  of  the 
score  are  cut  by  turning  the  other  sides  of  the  blocks  upwards,  and  repeating  the  above 
ooeration  The  shape  g  can  be  removed,  and  another  put  in  its  place,  for  diflerent  sizes 
and  curves  of  block;  but  the  same  pins  a,  and  holding  clamps  d,  wiU  suit  many  different 

By  these  machines  the  shells  of  the  blocks  are  completely  formed,  and  they  are  next 
polished  and  finished  by  hand  labor ;  but  as  this  is  performed  by  tools  and  methods  which 
are  well  known,  it  is  needless  to  enter  into  any  explanation :  the  finishing  required  bemg 
only  a  smoothing  of  the  surfaces.  The  machines  cut  so  perfectly  true  as  to  require  no 
wood  to  be  removed  in  the  finishing ;  but  as  they  cut  without  regard  to  the  irregularity 
of  the  grain,  knots,  &.c.,  it  happens  that  many  parts  are  not  so  smooth  as  might  be  wish- 
ed and  for  this  purpose  manual  labor  alone  can  be  employed. 

The  lignum  vitae  for  the  sheaves  of  the  blocks,  is  cut  across  the  grain  of  the  wooc  by 
two  cross-cutting  saws,  a  circular  and  straight  saw,  as  before  mentioned.  These  ma- 
chines do  not  essentially  differ  in  their  principle  from  the  great  cross-cutting  saws  we 
have  described,  except  that  the  wood  revolves  while  it  is  cutting,  so  that  a  small  saw  will 
reach  the  centre  of  a  large  tree,  and  at  the  same  time  cut  it  truly  flat.  The  limiis  pre- 
scribed for  our  plates  will  not  admit  of  giving  drawings  of  these  machines,  and  the  idea 
which  could  be  derived  from  a  verbal  description  would  not  be  materially  different  from 
the  cross-cutting  saws  before  mentioned.  These  machines  cut  off  their  plates  for  the  end 
of  the  tree,  which  are  exactly  the  thickness  for  the  intended  sheave.  These  pieces  are 
of  an  irregular  figure,  and  must  be  rounded  and  centred  in  the  crown  saw. 

9.  The  crovm  saw  is  represented  in  fig.  147,  where  A  is  a  pulley  revolving  by 
means  of  an  endless  strap.  It  has  the  crown  or  trepan  saw  a  fixed  to  it,  by  a  screw  cut 
within  the  piece,  upon  which  the  saw  is  fixed,  and  which  gives  the  ring  or  hoop  of  the 
saw  sufficient  stability  to  perform  its  oflice.  Both  the  pulleys  and  saw  revolve  together 
upon  a  truly  cylindrical  tube  6,  which  is  stationary,  being  attached  by  a  flaunch  c  to  a 
*^  -  fixed  puppet  b,  and  on  this  tube  as  an  ajiis 

the  saw  and  pulley  turn,  and  may  be  slid 
endwise  by  a  collar  fitted  round  the  centre- 
piece  of  the  pulley,  and  having  two   iron 
rods  (only  one  of  which  can  be  seen  at  d 
in  the  figure),  passing  through  holes  made 
through  the  flaunch  and  puppet  b.     When 
the  saw  is  drawn  back  upon  its  central  tube, 
the  end  of  the  latter  projects   beyond  the 
teeth  of  the  saw.  It  is  by  means  of  this  fixed 
ring  or  tube  within  the  saw,  that  the  piece 
of  wood  6  is  supported  during  the  operation 
of  sawing,  being  pressed  forcibly  against  it 
by  a  screw  d,  acting  through  a  puppet  fixed 
to  the  frame  of  the  machine.    At  the  end  of 
this  screw  is  a  cup  or  basin  which  applies 
itself  to  the  piece  of  wood,  so  as  to  form  a 
kind  of  vice,  one  side  being  the  end  of  the 
fixed  tube,  the  other  the  cup  at  the  end  of 
the  screw  d.     Within  the  tube  6  is  a  collar 
for  supporting  a  central  axis,  which  is  perfectly  cylindrical.     The  other  end  of  this  axis, 
(seen  at  /,)  turns  in  a  collar  of  the  fixed  puppet  e.    The  central  axis  has  a  pulley  f, 
fixed  on  it,  and  giving  it  motion  by  a  strap  similar  to  the  other.     Close  to  the  latter 
pulley  a  collar  g  is  fitted  on  the  centre  piece  of  the  pulley,  so  as  to  slip  round  freely, 
but  at  the  same  time  confined  to  move  endways  with  the  pulley  and  its  collar.     This  col- 
lar receives  the  ends  of  the  two  iron  rods  d.     The  opposite  ends  of  these  rods  are,  as 
above  mentioned,  connected  by  a  similar  collar,  with  the  pulley  A  of  the  saw  a.     By  this 
connexion,  both  the  centre  bit,  which  is  screwed  into  the  end  of  the  central  axis  /,  and 
the  saw  sliding  upon  the  fixed  tube  6,  are  brought  forward  to  the  wood  at  the  same  time, 
both  being  in  rapid  motion  by  their  respective  pulleys. 

10.  The  Cooking  Engine.— This,  ingenious  piece  of  machinery  is  used  to  cut  the  three 


206 


BLUE  DYES. 


semicircular  holes  which  surround  the  hole  hored  by  the  crown  saw,  so  as  to  produce  a 
cavity  in  the  centre  of  the  disc.  f        vc  a 

1 1.  Face-turning  Lathe— The  sheave  is  fixed  against  a  flat  chuck  at  the  end  of  a 
mandrel,  by  a  universal  chuck,  similar  to  that  in  the  coaking  engine,  except  that  the 
centre  pm,  instead  of  having  a  nut,  is  tapped  into  the  flat  chuck,  and  turned  by  a  screw- 
driver. 

BLOOD.  (Sang,  Fr. ;  Blut,  Germ.)  The  liquid  which  circulates  in  the  arteries  and 
vems  of  animals ;  bright  red  in  the  former  and  purple  in  the  latter,  among  all  the  tribes 
whose  temperature  is  considerably  higher  than  that  of  the  atmosphere.  It  consists,  1.  of 
a  colorless  transparent  soluUon  of  several  substances  in  water;  and,  2.  of  red,  undissolved 
particles  diffused  through  that  solution.  Its  specific  gravity  varies  with  the  nature  and 
health  of  the  animal ;  being  from  1-0527  to  1-0570  at  60°  F.  It  has  a  saline  sub-nauseous 
taste,  and  a  smell  peculiar  to  each  animal.  When  fresh  drawn  from  the  vessels,  it  rapidly 
coagulates  into  a  ge  atinous  mass,  called  the  clot,  cruor,  or  crassamentum,  from  which, 
after  some  time,  a  pale  yellow  fluid,  passing  into  yeUowish  green,  oozes  forth,  called  the 
*T*^L  '^''™  ^^«°?>  stirred  with  a  bundle  of  twigs,  as  it  flows  from  the  veins, 

the  fibnne  concretes,  and  forms  long  fibres  and  knots,  while  it  retains  its  usual  appear- 
ance m  other  respects.  The  clot  contains  fibrine  and  coloring  matter  in  various  pro- 
portions. Berzelius  found  in  100  parts  of  the  dried  clot  of  blood,  35  parts  of  fibrine  : 
68  of  coloring  matter ;  1-3  of  carbonate  of  soda  ;  4  of  an  animal  matter  soluble  in  water, 

1  ^!  "^1*/°™^  f '^^  ^^^  ^^^'  ^^^  ^P^*^^^<^  ^•^^•^y  of  the  serum  varies  from  1-027  to 
1-029  It  forms  about  three  fourths  of  the  weight  of  the  blood,  has  an  alkaline  leaction, 
coagulates  at  16^  F.  into  a  gelatinous  mass,  and  has  for  its  leading  consutuent  albumen 
to  the  amount  of  8  per  cent ,  besides  fat,  potash,  soda,  and  salts  of  these  bases.  Blood 
uoes  not  seem  to  contain  any  gelatine. 

The  red  coloring  matter  called  hemaline,  may  be  obtained  from  the  cruor  by  washing 
With  cold  water  and  filtering.  ^ 

Blood  was  at  one  time  largely  employed  for  clarifying  sirup,  but  it  is  very  sparingly 
used  by  the  sugar  refiners  in  Great  Britain  of  the  present  day.  It  may  be  dried  by  evapo- 
ration at  a  heat  of  130°  or  140°,  and  in  this  state  has  been  transported  to  the  colonies  for 
puritying  cane  juice.  It  is  an  ingredient  in  certain  adhesive  cements,  coarse  pigments  for 
protecting  walls  from  the  weather,  for  making  animal  charcoal  in  the  Prussian  blue  works, 
and  by  an  after  process,  a  decoloring  carbon.  It  is  used  in  some  Turkey  red  dye-works. 
Blood  IS  a  powerful  manure.  j  j  i«. 

BLOWING  MACHINE.  See  Iron,  Metalluhgt,  Ventilatiok. 
^  BLOWPIPE.  (Chalumeau,  Fr. ;  Lothrohn,  Germ.)  Jewellers,  mineralogists,  chero- 
isTs,  enamellers,  &c.,  make  frequent  use  of  a  tube,  usually  bent  near  the  end,  terminated 
with  a  finely  pointed  nozzle,  for  blowing  through  the  flame  of  a  lamp,  candle,  or  gas-jet, 
and  producmg  thereby  a  small  conical  flame  possessing  a  very  intense  heat.  Modifica- 
tions of  blow  pipes  are  made  with  jets  of  hydrogen,  oxygen,  or  the  two  gases  mixed  in 
due  proportions. 

BLUE  DYES.  {Tdnt,  Germ.  See  Enamel.)  The  materials  employed  for  this  pur- 
pose  are  indigo,  Prussian  blue,  logwood,  bUberry,  (vaccinium  myrtillus,)  elder  berries, 
(sambucus  nigra,)  mulberries,  privet  berries,  (ligustrum  vulgare,)  and  some  other  berries 
whose  juice  becomes  blue  by  the  addition  of  a  small  portion  of  alkali,  or  of  the  salts  of 
copper.  For  dyeing  with  the  first  three  articles,  see  them  in  their  alphabetical  places.  I 
shall  here  describe  the  other  or  minor  blue  dyes. 

^  To  dye  blue  with  such  berries  as  the  above,  we  boil  one  pound  of  them  in  water,  add- 
ing one  ounce  of  alum,  of  copperas,  and  of  blue  vitriol,  to  the  decoction,  or  in  their  stead 
equal  parts  of  verdigris  and  tartar,  and  pass  the  stuflfs  a  suflScient  lime  through  the  liquor. 
When  an  iron  mordant  alone  is  employed,  a  steel  blue  tint  is  obtained;  and  when  a  tin 
one,  a  blue  with  a  violet  cast.  The  privet  berries  which  have  been  employed  as  sap 
r  ?r  L-  ^^'^^  painters,  may  be  extensively  used  in  the  dyeing  of  silk.  The  berries 
liJ*  Alrican  night-shade  (solanum  guineetise)  have  been  of  late  vears  cor.siderably  ap- 
plied to  silk  on  the  continent  in  producing  various  shades  of  blue,  violet,  red,  brown,  &c., 
but  particulariy  violet.  With  alkalis  and  acids  these  berries  have  the  same  habitudes  as 
bilberries ;  the  former  turning  them  green,  the  latter  red.  They  usually  come  from 
Italy  compressed  in  a  dry  cake,  and  are  infused  in  hot  water.  The  infusion  is  merely 
Wtered,  and  then  employed  without  any  mordant,  for  dyeing  sUk,  being  kept  at  a  warm 
temperature  by  surrounding  the  bath  vessel  with  hot  water.  The  goods  must  be  winced 
for  six  hours  through  it  in  order  to  be  saturated  with  color ;  then  they  are  to  be  rinsed 
in  running  water  and  dried.  One  pound  of  silk  requires  a  pound  and  a  half  of  the  berry 
cake.  In  the  residuary  bath,  other  tints  of  blue  may  be  given.  Sometimes  the  dyed 
silk  is  finished  by  running  it  through  a  weak  alum  water.  A  color  approaching  to  in- 
digo m  permanence,  but  which  differs  from  it  in  being  soluble  in  alkalis,  though  inca- 
pable  of  similar  disoxydizement,  is  the  gardenia  genipa  and  acuUata  of  South  America 
whose  colorless  juice  becomes  dark  blue  with  conUct  of  airj  and  dyes  stuffs,  the  skin 


I 


BOILERS. 


207 


and  nails  of  an  unchangeable  deep  blue  color,  but  the  juice  must  be  applied  in  the  color- 
less state.    See  Indigo  and  Prussian  Blue.  .  i         i  •  ^^ 

BLUE  PIGMENTS.  Several  metallic  compounds  possess  a  blue  color;  especially 
those  of  iron,  cobalt,  and  molybdenum.  Tlie  metallic  pigments,  little  if  at  all  employed, 
but  which  may  be  found  useful  in  particular  cases,  are  the  molybdate  of  mercury,  the 
hydro-sulphuret  of  tungsten,  the  prussiate  of  tungsten,  the  molybdate  of  tin,  the  oxide  of 
copper  darkened  with  ammonia,  the  silicate  of  copper,  and  a  fine  violet  color  formed 
from  manganese  and  molybdenum.  The  blues  of  vegetable  origin,  in  common  use,  are  in- 
digo, litmus,  and  blue  cakes.  The  blue  pigments  of  a  metallic  nature  found  in  com- 
merce are  the  following ;  Prusdan  blue  ;  mountain  blue,  a  carbonate  of  copper  mixed  with 
more  or  less  earthy  matter  ;  Bremen  blue  or  verditer,  a  greenish  blue  color  obtained 
from  copper  mixed  with  chalk  or  lime ;  iron  blue,  phosphate  of  iron,  little  employed ; 
cobalt  blue,  a  color  obtained  by  calcining  a  salt  of  cobalt  with  alumina  or  oxide  of  tin; 
muilt,  a  glass  colored  with  cobalt  and  ground  to  a  fine  powder;  charcoal  blue,  a  deep 
shade'  obtained  by  triturating  carbonized  vine  stalks  with  an  equal  weight  of  potash  in 
a  crucible  till  the  mixture  ceases  to  swell,  th^m  pouring  it  upon  a  slab,  putting  it  into 
water,  and  saturating  the  alkali  with  sulphuric  acid.  The  liquor  becomes  blue,  and 
lets  fall  a  dark  blue  precipitate,  which  becomes  of  a  brilliant  blue  color  when  heated. 

Molybdenum  blue  is  a  combination  of  this  metal,  and  oxide  of  tin,  or  phosphate  of 
lime.  It  is  emplo5'ed  both  as  a  paint,  and  an  enamel  color.  A  blue  may  also  be  ob- 
tained by  putting  into  molybdic  acid  (made  by  digesting  sulphuret  of  molybdenum 
with  nitric  acid)  some  filings  of  tin  and  a  little  muriatic  acid.  The  tin  deoxidizes 
the  molybdic  acid  to  a  certain  degree,  and  converts  it  into  the  molybdous,  which, 
when  evaporated  and  heated  with  alumina  recently  precipitated,  forms  this  blue  pig- 
ment    Ultramarine  is  a  beautiful  blue  pigment,  which  see. 

BLUE     Turnbull's  and  Chinese  are  both  double  cyanides  of  iron. 

BLUE  VITRIOL;  sulphate  of  copper. 

BOILERS  {construction  of). — The  modifications  of  the  steam  engine  which  hare 
been  adopted  since  its  introduction  by  Watt,  three  quarters  of  a  century  ago,  have  been 
very  numerous  and  varied ;  and  although  the  progression  in  its  applications  and  improve- 
ments has  been  most  rapid  and  wonderful,  we  are  still  undecided  as  to  the  best  form  of 
its  construction.  Sound  principles  scientifically  applied,  and  the  gradually  increasing  ex- 
cellence of  our  mechanical  workshops,  have  enabled  us  to  attain  the  great  perfection 
which  characterizes  the  working  parts  of  the  modern  steam  engine.  The  steam  engine 
itself  may  be  regarded  as  a  comparatively  perfect  machine,  and  therefore  we  shall  confine 
our  observations  almost  exclusively  to  that  very  important  and  necessary  adjunct — the 
Boiler — which  is  the  source  of  its  power.  With  this  limitation,  a  very  wide  field  of  in- 
quiry is  opened  out,  and  in  the  earliest  steps  of  the  investigation  we  become  perplexed 
with  the  endless  variety  of  forms  and  constructions  which  at  different  periods  have  been 
adopted  by  engineers,  and  which  have  never,  unfortunately,  received  the  same  Judicious 
attention  that  was  paid,  as  I  have  already  remarked,  to  the  steam  engine.  This  is  an  ano- 
malous and  much  to  be  regretted  fact,  for  the  boiler,  being  the  source  of  the  motive  pow- 
er, is  undoubtedly  one  of  the  most  important  parts  of  the  whole  machine.  Upon  its 
proper  proportions  and  arrangements  for  the  generation  of  steam,  depend  the  economy 
and  regularity  with  which  the  engine  can  be  worked,  and  upon  its  strength  and  excel- 
lence of  workmanship  depends  the  safety  of  the  lives  and  property  of  those  who  come  in 
contact  with  it.  Regarding  the  steam  engine  as  one  of  the  most  active  agents  in  the 
extension  of  our  prosperity,  and  in  the  civilization  of  the  world,  and  seeing  how  it  is 
mixed  up  with  the  daily  duties  and  working  of  society,  the  safety  and  efficiency  of 
every  part,  and  more  especially  the  boiler,  are  subjects  of  national  importance ;  and 
it  is  of  great  consequence  to  introduce  here  such  knowledge  and  experience  on  this 
subject  of  deep  interest  as  has  been  offered  by  William  Fairbairn,  Esq. 

"The  boiler  may  be  considered  in  its  construction,  management,  security,  and  eco- 
nomy. 1st  As  to  the  construction.  Here  I  shall  have  to  go  a  little  into  detail,  in 
order  to  show,  in  construction,  the  absolute  necessity  there  exists  for  adhering  to  form 
and  other  considerations  essential  in  the  practice  of  mechanical  engineers,  so  as  to 
effect  the  maximum  of  strength,  with  the  minimum  of  material.  In  boilers  this  is  the 
more  important  as  any  increase  in  the  thickness  of  the  plates  obstructs  the  transmis- 
sion of  heat,  and  exposes  the  rivets  as  well  as  the  plates  to  injury  on  the  side  exposed 
to  the  action  of  the  furnace. 

"  It  has  generally  been  supposed  that  the  rolling  of  boiler  plate  iron  gives  to  the 
sheets  greater  tenacity  in  the  direction  of  their  length  than  in  that  of  their  breadth  ; 
this  is,  however,  not  correct ;  as  a  series  of  experiments  which  Mr.  Fairbairn  made 
some  years  since  fully  proves  that  there  is  no  difference  in  the  tensile  strength  of 
boiler  plates  whether  torn  asunder  in  the  direction  of  the  fibre,  or  across  it  From 
five  different  sorts  of  iron  the  following  results  were  obtained  :— 


hr 


208 


Deecription  of  Iron. 

Yorkshire  plates 
Yorkshire  plates 
Derbyshire  plates 
Shropshire  plates 
Staffordshire  plates 

Mean 


BOILERS. 

Mean  Breaking  weight 
In  tons,  in  the  direc- 
tion of  the  fibre. 

-  26-7'?  - 

-  22-76  - 

-  21-68  - 

-  22-82  - 

-  19-66  - 


Mean  Breaking  weight 
in  tons  across  th« 
fibre. 

27-49 
26-37 
18-66 
22-00 
21-01 


-     22-51 


2310 


100 

70 
56 


"Assuming  the  strength  of  the  plate  to  be         ... 

fhp^Im^^''  ""^  a  double  riveted  joint  would  be.  after  allowing  for 
the  adhesion  of  the  surfaces  of  the  plate       -        -  ^ 

And  the  strength  of  a  single  riveted  joint  .        . 

the  direction  of  the  greatest  strain  ;  and  in  order  to  accomDlisfi  fhi!  ff  ^mt       ^ 

derived  from  experimental  research.     On  this  head  I  am  forfntinfi^  Jn  i!!l-  ^i    ?^ 
me  thecalculations  of  Professor  W.  R.  Johnson,  of  the  F™aSn?i:tLeo^^^^^^^^^ 

whrch  JryVr  •"'"  '''\''T^'^  -f  cylindrical  boilers  are  ogreft'aL  and  from 
which  the  following  short  abstract  may  be  useful.  ' 

"Ist  To  know  the  force  which  tends  to  burst  a  cvlindrical  ves<iPl  in  il,^  I^t.^;*  ;i- 

and  at  the  moment  when  ruptuTe  is  about  to  tit!  ^       .K*T'"f,  "^^  ^^'f '""'  ^«^<^^ 
cent  forces  must  obviously  be  equal  ^  '"'"  *^'  ^'^'"^^^  *^^  ^^«  ^^^^s- 

"  2d.  To  ascertain  the  amount  of  force  which  tPTidatniniT^f  «,.«*!,       v    j       i 
curved  side,  or  rather  along  the  opposite  sTdpfwP^ni.^^^K*^^ '^y^'"^^'' *^^"^ 
through  th;  whole  breadUi  of  tL^  c^lntr  uTreLhTnl       ^I'Tl'^  as  applied. 
Hence  the  total  amount  of  force  whichVould  te^d  to  d  vide  the  cvlinf  '^'  ^^T'^t'' 
separating  it  along  two  lines,  on  opposite  sides  would  bll!..     ^  if  l"" '°  halves,  by 
the  diameter  by  the  force  exe;ted  on  each  unU  of  surface  and  S,?''''*^^  by  muH..i  j^^ 
of  the  cylinder-;     But  even  without  regarSnf  the  feni^^^^^^ 
requisite  to  rupture  a  single  band  in  thf  direclon^o^XV^edT^^dTon^^^^^^^^^^^ 


BOILERS. 


209 


in  breadth  ;  since  it  obviously  makes  no  difference  whether  the  cylinder  be  long  or 
short,  in  respect  to  the  ease  or  difficulty  of  separating  the  sides.  The  divellent  force  ir 
this  directi<)n  is,  therefore,  truly  represented  by  the  diameter  multiplied  by  the  preft> 
sure  per  unit  of  surface.  The  retaining  oi*  quiescent  force,  in  the  same  direction,  is 
only  the  strength  or  tenacity  of  the  two  opposite  sides  of  the  supposed  bond.  Here 
also,  at  the  moment  when  a  rupture  is  about  to  occur,  the  divellent  force  must  exactly 
equal  the  quiescent  force. 

*'  Mr.  Johnson  then  goes  on  to  show  that,  as  the  diameter  is  increased,  the  product 
of  the  diameter,  and  the  force  or  pressure  per  unit  of  surface,  are  increased  in  the  same 
ratio.    This  truth  I  shall  endeavor  to  prove ;    as,  also,  that,  as  the  diameter  of  any 
cylindrical  vessel  is  increased,  the  thickness  of  the  metal  must  also  be  increased  in  the 
exact  ratio  of  the  increase  of  the  diameter:  the  pressure,  or  as  Mr.  Johnson  calls  it,  the 
divellent  force,  being  the  same  when  the  diameter  of  a  boiler  is  increased,  it  must  be 
borne  in  mind  that  the  area  of  the  ends  is  also  increased,  not  in  the  ratio  of  tlie  diameter 
but  in  the  ratio  of  the  square  of  the  diameter :  and  it  will  be  seen  that  instead  of  the 
force  being  doubled,  as  is  the  case  in  the  direction  of  the  diameter  and  circumference, 
it  is  quadrupled  upon  the  ends,  or,  what  is  the  same  thing,  a  c^^inder  double  the  dia- 
meter of  another  cylinder  has  to  sustain  four  times  the  pressure  in  the  longitudinal 
t  direction.     The  retaining  force  of  the  thickness  of  the  metal  of  a  cylindrical  boiler  does 
not^  however,  increase  in  the  same  ratio  as  the  area  of  the  circle,  but  simply  in  the 
ratio  of  the  diameter ;  consequently,  the  thickness  of  the  metal  will  require  to  be  in- 
creased in  the  same  ratio  as  the  diameter  is  increased.     From  this  it  appears,  that  the 
tendency  to  rupture  by  blowing  out  the  ends  of  a  cylindrical  boiler  will  not  be  greater 
in  this  direction  than  it  is  in  any  other  direction ;  we  may  therefore  safely  conclude, 
since  we  have  seen  that  the  tendency  to  rupture  increases  in  both  directions  in  the 
ratio  of  the  diameter,  that  any  deviation  from  that  law,  as  regards  the  thickness  of 
the  i)lates,  would  not  increase  the  strength  of  the  boiler. 

"  I  have  been  led  to  these  inquiries  from  the  circumstance  that  Mr.  Johnson  appears 
to  reason  on  the  supposition  that  there  are  no  joints  in  the  plates,  and  that  the  tena- 
city of  the  iron  is  equal  to  60,000  lbs.— rather  more  than  26  tons  to  the  square  inch. 
Aow,  we  have  shown  by  the  results  of  the  experiments  already  adduced,  that  ordinary 
boiler  plates  will  not  bear  more  than  23  tons  to  the  square  inch;  and,  as  nearly  one 
third  ot  the  material  is  punched  out  for  the  reception  of  the  rivets,  we  must  still 
lurther  reduce  the  strength,  and  take  15  tons  or  about  34,000  lbs.*  on  the  square  inch 
**«  fn  ^-^^^^^^y ^^  <^he  material  or  the  pressure  at  which  a  boiler  would  burst 

Ihis  I  should  consider  in  practice  as  the  maximum  power  of  resistance  of  boiler 
plates  m  their  riveted  state,  and  I  will  now  endeavor  to  show  you  in  a  very  concise, 
and  1  trust  not  uninteresting  investigation,  the  bearing  power  of  boiler^  and  the 
pressure  at  which  they  can  be  worked  with  safety.  It  has  been  stated  that  the  strength 
of  cylindrical  boilers,  when  taken  in  the  direction  of  their  circumference,  is  in  the  raUo 
of  their  diameters,  and  when  taken  in  the  direction  of  the  ends,  as  the  squares  of  the 
diameters,— a  proposition  which  it  will  not  be  difficult  to  demonstrat^  as  applica- 
ble to  every  description  of  boUer  of  the  cylindrical  form.  It  will  be  seen,  however,  that 
tlie  strain  is  not  exactly  the  same  in  every  direction,  and  that  there  is  actually  less 
upon  the  material  in  the  longitudinal  direction  than  there  is  upon  the  circumference, 
for  example  let  us  take  two  boilers,  one  three  feet  diameter  and  the  other  six  feet  and 
suppose  each  to  be  subject  to  a  pressure  of  40  lbs.  on  the  square  inch.  In  this  condi- 
tion. It  is  evident  that  the  area  or  number  of  square  inches  in  the  end  of  a  three-feet 
of  aHth?;  r  "-f  ^ -n^K  r ^  ^J}}''  '^^^'''  ^"^1^^'  ««  1  ^«  4 ;  and,  by  a  common  proceL 
of  t^  1  Zn'V  h'^K^-V'  ^^""^  ^\'^^  *^'  "^S^^  ^^  ^^'^  P^^*^«  formingihe  cylindrical  part 
40  7^'l"'  Y7.0?  «^^J««t  (at  40  lbs.  on  the  square  inch)  to  a  pressure  of 
40,7121  bs.,  upwards  of  18  tons:  whereas  the  plates  of  the  six-feet  boiler  hive  to  sue- 

b'oiler  Lrr  1  'u;f'V^'-'  r  ^?  '""«'  ^^"'^  ^«  ^^^^-Pl-  '^^  force  to  which  t^ 
to  1  thopi^         half  the  diameter  is  exposed;  and  the  circumference  being  only  as  2 

W  hti  'noT?r'^  ^'  •?/'  J?'  '^T  "P^^  "^"  cylindrical  plates  of  the  large  boiler, 
cv  irndir  in.  T^'  "^n"  ^^'^-  "^¥*'  P^^*"  «^  ^^'^  ^^i^^^'  a^  the  circumference  of  a 

s&f  b.?nr''  ^^^T'  *^1  '^'^^^^  '^'''  diameter;  consequently,  the  pressure,  iu- 
cnds  is  onh  dmX'Tff  '^-  '^'  ?''''  ^^  ?".  ^^"^^«  «^  ^^«  ^i^'^^^ter,  as  shown  in  the 
thre;-fect  boifer     ^         circumference  of  the  six-feet  boiler  being  twice  that  of  the 

havc^dLTrit'd^\?h^^^  '"PP^^  *^^  *^°  cylindrical  boilers,  such  as  we 

onJnf  f  i!!  1  '  ^^.^^,,<^^^3^c<i  i^to  a  series  of  hoops  of  one  inch  in  width ;  and,  taking 
on  thl  «  '  l^««P«»nt,be  three-feet  boiler,  we  shall  find  itexposed,atapres  ureof  401bf 
on  the  square  inch,  to  a  force  of  1,440  lbs.,  acting  on  each  side  of  a  line  drawn  through 

BtrtSh  Tthe'"pkteVi?f- bliftJkJn^  Zf^^^  ^I  the  riveted  joints  of  boilers  is  onlv  about  one-half  the 

•bly  fe  Uken  aithe  teSv  of  t^«  h!  ^a  ««f  »<leration  U.e  crossing  of  the  joints,  ^4,000  lbs.  may  reasoa^ 

Vou  L  ^^'^'^y  °^  the  riveted  plates,  or  the  bursting  pressure  of  a  cylindrical  boiler.       ^^ 


i  il 


! 


210 


BOILERS. 


149 


the  axis  of  a  cylinder  36  inches  diameter  and  1  inch  in  depth,  and  which  line  forms  th« 
diameter  of  the  circle.  Now,  this  force  causes  a  strain  upon  the  points  a  a  in  the 
l^g     jj  direction  of  the  arrows  in  the  annexed  diagram  of  the  three-feet  circle, 

of  720  lbs.,  and,  assuming  the  pressure  to  be  increased  till  the  force  be- 
comes equal  to  the  tenacity  or  retaining  powers  of  the  iron  at  a  a,  it 
is  evident,  in  this  state  of  the  equilibrium  of  the  two  forces,  that  the 
least  preponderance  on  the  side  of  the  internal  pressure  would  insure 
fracture.  And  suppose  we  take  the  plates  of  which  the  boiler  ia 
composed  at  one  quarter  of  an  inch  thick,  and  the  ultimate  strength  at 

34,000  lbs.  on  the  square  inch,  we  shall  have  ^^  —  472  per  squaro 

inch,  as  the  bursting  pressure  of  the  boiler.  Again,  as  the  forces  in  this  direction 
are  not  as  the  squares,  but  simply  as  the  diameters,  it  is  clear  that  at  40  lbs.  on  the 
square  inch  we  have  in  a  hoop  an  inch  in  depth,  or  that  portion  of  a  cylinder  whose 
diameter  is  six  feety  exactly  double  the  force  applied  to  the  points  b  b,  which  was  acting 
'^"  on  the  points  a  a,  ii:  the  diameter  of  three  feet     Now,  as- 

suming the  plates  to  be  a  quarter  of  an  inch  thick,  as  in  the 
three-feet  boiler,  it  follows,  if  the  forces  at  the  same  pressure 
be  doubled  in  the  large  cylinder,  that  the  thickness  of  the 
plates  mu!?t  also  be  doubled  in  order  to  sustain  the  same 
pressure  with  equal  security ;  or  what  is  the  same  thing, 
the  six-feet  boiler  must  be  worked  at  half  the  pressure, 
in  order  to  insure  the  same  degree  of  safety  as  attained  in 
the  three-feet  boiler  at  double  the  pressure.  From  these 
facts  it  may  be  useful  to  know,  that  boilera  having  increased 
dimensions  should  also  have  increased  strength  in  the  ratio 
of  their  diameters ;  or,  in  other  words,  the  plates  of  a  six- 
feet  boiler  should  be  double  the  thickness  of  the  plates  of 
a  three-feet  boiler,  and  so  on  in  proportion  as  the  diameter 
is  increased. 

"The  relative  power  of  force  applied  to  cylinders  of  different  diameters  becomes  more 
strikingly  apparent  when  we  reduce  them  to  their  equivalents  of  strain  per  square  inch, 
as  applied  to  the  ends  and  circumference  of  the  boiler  respectively.  In  the  three -feet 
boiler,  working  at  40  lbs.  pressure,  we  have  a  force  equal  to  720  lbs.  upon  an  inch 
width  of  plate,  and  one  quarter  of  an  inch  thick,  or  720  by  4  =*  2,880  lbs.,  the  force 
per  square  inch  upon  every  point  of  the  circumference  of  the  boiler.  Let  us  now  com- 
pare this  with  the  actual  strength  of  the  riv«ted  plates  themselves,  whjch,  taken  as 
before,  at  34,000  lbs.  on  the  square  inch,  we  arrive  at  the  ratio  of  pressure  as  ap- 
plied to  the  strength  of  the  circumference,  as  2,880  to  34,000,  nearly  as  1  to  12,  or  472  lbs. 
per  square  inch,  as  the  ultimate  strength  of  the  riveted  plates. 

"These  deductions  appear  to  be  true  in  every  case  as  regards  the  resisting  powers 
of  cylindrical  boilers  to  a  force  radiating  in  every  direction  from  the  axis  towards  the 
circumference ;  but  the  same  reasoning  is,  however,  not  maintained  when  applied  to 
the  ends,  or,  to  speak  technically,  to  the  angle  iron  and  riveting,  where  the  ends  are 
attached  to  the  circumference.  Now,  to  prove  this,  let  us  take  the  three- feet  boiler, 
where  we  have  113  inches  in  the  circumference;  and  upon  this  circular  line  of  connec- 
tion we  have,  at  40  lbs.  to  the  square  inch,  to  sustain  a  pressure  of  18  tons,  which  is 
equal  to  a  strain  of  360  lbs.,  acting  longitudinally  upon  every  inch  of  the  circumfer- 
ence. Apply  the  same  force  to  a  six-feet  boiler,  with  a  circumference  or  line  of  con- 
nection equal  to  226  inches,  and  we  shall  find  it  exposed  to  exactly  four  times  the 
force,  or  72  tons;  but,  in  this  case,  it  must  be  borne  in  mind,  that  the  circumference 
is  doubled,  and  consequently  the  strain,  instead  of  being  in  the  quadruple  ratio,  is 
only  doubled,  or  a  force  equal  to  720  lbs.  acting  longitudinally,  as  before,  upon  every 
inch  of  the  circumference  of  the  boiler.  From  these  facts  we  come  to  the  conclusion, 
that  the  strength  of  cylindrical  boilers  is  in  the  ratio  of  their  diameters  if  taken  in  the 
line  of  curvature,  ana  as  the  squares  of  the  diameters  as  applied  to  the  ends  or  their 
sectional  area;  and  that  all  descriptions  of  cylindrical  tubes,  to  bear  the  same  pres- 
sure, must  be  increased  in  strength  in  the  direction  of  their  circumference  simply  as 
their  diameters,  and  in  the  direction  of  the  ends  as  the  squares  of  the  diameters. 

"  Again,  if  we  refer  to  the  comparative  merits  of  the  plates  composing  cylindrical 
vessels  subjected  to  internal  pressure,  they  will  be  found  in  this  anomalous  condition, 
that  the  strength  in  their  longitudinal  direction  is  twice  that  of  the  plates  in  the  curvi- 
linear direction.  This  appears  by  a  comparison  of  the  two  forces,  wherein  we  have 
shown  that  the  ends  of  the  three-feet  boiler,  at  40 lbs.  internal  pressure,  sustain  360 lbs. 
of  longitudinal  strain  upon  each  inch  of  a  plate  a  quarter  of  an  inch  thick ;  whereas  the 
same  thickness  of  plates  has  to  bear  in  the  curvilinear  direction  a  strain  of  720  lbs. 
ThiA  Jiffereucc  of  strain  is  a  difficulty  not  easily  overcome  ;  and  all  that  we  can  accom- 


I 


BOILERS. 


211 


plish  in  this  case  will  be  to  exercise  a  sound  judgment  in  crossing  the  joints,  in  the 
quality  of  the  workmanship,  and  the  distribution  of  the  material.  For  the  attain- 
ment of  these  objects,  the  following  table,  which  exhibits  the  proportionate  strength  of 
cylindrical  boilers  from  three  to  eight  feet  in  diameter,  may  be  usefuL 

"  Table  of  equal  Strengths  in  CylindricaJ.  Boilers  from  3  to  ^  feet  diameter^  showing  tht 
thickness  of  metal  in  each  respectively,  at  a  pressure  of  460  lbs.  to  tlie  square  inch. 


Diameter  of 
Boilers. 

Bursting  Pressure  equivalent  to  the 
ultimate  strensth  of  the  riveted  Joints, 
as  deduced  from  experiment,  84»000  lbs. 
to  the  square  inch. 

Thickness  of  the 

Plates  in 

Decimal  parts 

of  an  Inch. 

Ft    Inch. 

3         0 

3  6 

4  0 
4        6 

450  lbs. 

•260 
•291 
•333 
•376 

6        0 

— 

•416 

6         6 

-^ 

•458 

6        0 

— 

•600 

6        6 

— 

•641 

7        0 

— 

•683 

7  6 

8  0 

— 

•625 
•666 

**  Boilers  of  the  simple  form,  and  without  internal  flues,  are  subjected  only  to  one 
species  of  strain;  but  those  constructed  with  internal  flues  are  exposed  to  the  same  ten- 
sile force  which  pervades  the  simple  form ;  and,  further,  to  the  force  of  compression 
whi(?h  tends  to  collapse  or  crush  the  material  of  the  internal  flues.  In  the  cylindrical 
boiler  with  round  flues,  the  forces  are  diverging  from  the  central  axis  as  regards  the 
outer  shelly  and  convergmg  as  applied  to  every  separate  flue  which  the  boiler  contains. 
Ihese  two  forces  in  a  steam  boiler  are  in  constant  operation  ;  the  tendency  of  the 
one  being  to  tear  up  the  external  plates  and  force  out  the  ends,  and  the  other  to  destroy 
the  form  and  to  force  the  material  into  the  central  area  of  the  flues.  These  two  forc^ 
operate  widely  different  upon  the  resisting  powers  of  the  boiler,  which,  taken  in  the  di- 
rection of  its  exterior  envelope,  has  to  resist  a  tensile  strain  operating  in  every  direction 

n?.l^n  f '"'"  -.'k  '  "f'^\T^  ^T  ?'""^  ^^  *"  ^'-^^  «ff^'-  ^powerful  resistance  to  com- 
pression from  without  It  might  be  instructive  as  well  as  interesting  to  exhibit  the 
nature  of  these  powers  and  determine  the  law  by  which  vessels  of  this  description  are 
retained  m  shape,  but  this  can  only  be  done  by  experiment;  and  as  these  expLrimente 
Irt.lri^^  f  conducted  upon  a  large  scale,  and  with  great  accuracy,  in-order  to 
arrive  at  satisfactory  results,  we  must  abandon  the  idea  for  the  present^  and  content 
ourselves  with  such  infornriation  as  we  already  possess.  '  At  some  future  peHodTnay 
possibly  devote  my  attention  to  this  subject  It  is  one  of  great  importance  and  I 
series  of  well-con<^ucted  experiments  wo'uld,  I  make  no  dou1>t  sup^Y  vXable  data 
in  the  varied  requirements  of  boiler  construction,  and  their  comZati^e^were  of 

«Z^;%he  exltiryrr'  ''"r '  ?°i  compression.'-(i^r.  Flrbai::^sT:ure) 
)t  I  om  the  existing  state  of  our  knowledge,  we  must  rest  satisfied  with  the  fact  that 
the  resisting  powers  of  cylindrical  flues  to%ompression  will  bHi^eTuy  as  their  di^ 
r.t  TV  *n  ":t  ™*>^^h^rcfore  conclude  that  a  circular  flue  18  incCi^PdiWter  w  U 

^^;p^:^^^^  -  com -nSr^- 

meter"  h-lZ^J'LT"'''t^  ""i '*''^'"  l^'^i  *  high-pressure  boiler  30  feet  long,  6  feet  dia- 
M  Ibl'  on  Sir. fw  1?  ^""'Y^'^  2  f^^t  Sfnches  diameter,  working  at  a  pressure  of 
foci  1  0?0  pvn?«  Tf  '  "^^  ^^J^  ^"^y  ^  '""^^^P^y  ^^^  '^^raber  oflquarefeetof  sur- 
Wer  of  ?heL^rln"«jr''r'';  ^^  ^r'.'  ^^^r  ^^  ^'^^'  '^'^  f«r<^«  of  ^'319  tons,  which  a 
pressure  whe^i'^^^^^^         ^'^'  to  sustain.     I  mention  this  to  show  that  the  statistics  of 

TkrwLTie  o^tJie  rf t^  •^''  ^^^  ^.""^"'i  ^"  themselves,  but  instructive  as  regards 
breaHf  fh  ^,f  retaining  powers  of  vessels  so  extensively  used,  and  on  which  the 
P  et re  to  bTat  4«oTh  "^"  J""  P"-««.^he  subject  a  little  further.'  let  us  suppose  the 
deter iption  win  htt!  b  f ''''  ^^  «q"^^«  i««h,  which  a  well-constructed  boillr  of  this 
ne ulv^so  000  L«  K  .H  r  '^  ^l"^^"^  *"^  ^«  *^*^«  ^^^  enormous  force  of  29.871,  or 
"ihi^i  horv  •  ^^  •?  '^V*^'°  *  "y^'"*^^''  30  feet  long  and  6  feet  diameter. 
Ihis  IS,  however,  inconsiderable  when  compared  with  the  locomotive  and  mme 


212 


BOILERS. 


BOILERS. 


:.f 


I 


t.  r 
r  f 


f  ii 


^    I 

f      if 


marine  boilers,  which,  from  the  number  of  tubes,  present  a  much  larger  extent  of  sur 
face  to  pressure.  Locomotive  engines  are  usually  worked  at  80  to  100  lbs.  on  the  inch , 
and,  taking  one  of  the  usual  construction,  we  shall  find,  at  100  lbs.  on  the  inch,  that  it 
rushes  forward  on  the  rail  with  a  pent-up  force  within  its  interior  of  nearly  60,000 
tons,  which  is  rather  increased  than  diminished  at  an  accelerated  speed. 

"  In  a  stationary  boiler  charged  with  steam  at  a  given  pressure,  it  is  evident  that  the 
forces  are  in  perfect  equilibrium,  and,  the  strain  being  the  same  in  all  directions,  there 
will  be  no  tendency  to  motion.  Supposing,  however,  this  equilibrium  to  be  destroyed 
by  accumulative  pressure  till  rupture  ensues,  it  then  follows  that,  the  forces  in  one  di- 
rection having  ceased,  the  other  in  an  opposite  direction,  being  active,  would  project 
the  boiler  from  its  seat  with  a  force  e(jual  to  that  which  is  discharged  through  the  ori- 
fice of  rupture.  The  direction  of  motion  would  depend  upon  the  position  of  the  rup- 
tured part.  If  in  the  line  of  the  centre  of  gravity,  motion  would  ensue  in  that  direc- 
tion ;  if  out  of  that  line,  an  oblique  or  rotatory  motion  round  the  centre  of  gravity 
would  be  the  result. 

"  The  velocity  or  quantity  of  motion  produced  in  one  direction  would  be  equal  to  the 
intensity  or  quantity  lost ;  and  the  velocity  with  which  the  body  would  move  would 
be  in  the  ratio  of  the  impulsive  force,  or  the  quantity  lost.  Therefore,  the  quantity 
of  motion  gained  by  an  exploded  boiler  in  one  direction  will  be  as  its  weight  and  the 
quantity  lost  in  that  direction.  These  definitions  are,  however,  more  in  the  province 
of  the  mathematician,  and  may  easily  be  computed  from  well-known  formulte  on  the 
laws  of  motion. 

"  We  now  come  to  the  rectangular  forms,  or  flat  surfaces,  which  are  not  so  well  cal- 
culated to  resist  pressure.  Of  these  we  may  instance  the  fire-box  of  the  locomotive 
boiler,  the  sides  and  flues  of  marine  boilers — the  latter  of  which,  by  the  by,  are  now 
superseded  by  those  of  the  tubular  form — and  the  flat  ends  of  the  cylindrical  boilers, 
and  others  of  weaker  construction. 

"The  locomotive  boiler  is  frequently  worked  up  to  a  pressure  of  120  lbs.  on  the  square 
inch,  and  at  times,  when  rising  steep  gradients,  1  have  known  the  steam  nearly  as  high 
as  200  lbs.  on  the  inch.  In  a  locomotive  boiler  subject  to  such  an  enormous  working 
pressure,  it  requires  the  utmost  care  and  attention  on  the  part  of  the  engineer  to  satisfy 
himself  that  the  flat  surfaces  of  the  fire-box  are  capable  of  resisLiug  that  pressure,  and 
that  every  part  of  the  boiler  is  so  nearly  balanced  in  its  powers  of  resistance,  as  that, 
when  one  part  is  at  the  point  of  rupture,  every  other  part  is  on  the  point  of  yielding 
to  the  same  uniform  force.  This  appears  to  be  an  important  consideration  in  mecha- 
nical constructions  of  every  kind,  as  any  material  applied  for  the  security  of  one  part 
of  a  vessel  subject  to  uniform  pressure,  whilst  another  part  is  left  weak,  is  so  much 
material  thrown  away ;  and  iu  stationary  boilers,  or  in  moving  bodies,  such  as  loco- 
motive engines  and  steam  vessels,  it  is  absolutely  injurious,  at  least  so  far  as  the  parts 
are  disproportionate  to  each  other,  and  the  extra  weight  when  maintained  in  motion 
becomes  an  expensive  and  unwieldy  encumbrance.  A  knowledge  of  the  strength  of 
materials  used,  judicious  care,  and  the  exercise  of  sound  judgment  in  its  distribution, 
are  therefore  some  of  the  most  essential  qualifications  of  the  practical  engineer.  Our 
limited  knowledge  and  defective  principles  of  construction  are  manifest  from  the  nu- 
merous abortions  which  exist,  and,  although  I  am  free  to  communicate  all  that  I  know 
on  the  subject,  I  nevertheless  find  myself  deficient  in  many  of  the  requirements  ne- 
cessary for  the  attainment  of  sound  principles  of  construction. 

"  Reverting  to  the  question  more  immeaiately  under  consideration,  it  is,  however, 
essential  to  give  the  requisite  security  to  those  parts  which,  if  left  unsupported,  would 
involve  the  public  as  well  as  ourselves  in  the  greatest  jeopardy. 

"  The  greater  portion  of  the  fire-boxes  of  locomotive  boilers,  as  before  noticed,  have 
the  rectangular  form,  and,  in  order  to  economize  heat  and  give  space  for  the  furnace, 
it  becomes  necessary  to  have  an  interior  and  exterior  shell. 

"  That  which  contains  the  furnace  is  generally  made  of  copper,  firmly  united  by  rivets, 
and  the  exterior  shell,  which  covers  the  fire-box,  is  made  of  iron  and  united  by  rivets 
in  the  same  way  as  the  copper  fire-box.  Now  these  plates  would  of  themselves  be  to- 
tally inadequate,  unless  supported  by  riveted  stays  to  sustain  the  pressure.  In  fact, 
witn  one-tenth  the  strain,  the  copper  fire-box  would  be  forced  inwards  upon  the  furnace 
and  the  external  shell  bulged  outwards,  and  with  every  change  of  force  these  two  flat 
surfaces  would  move  backwards  and  forwards,  like  the  sides  of  an  inflated  bladder, 
at  the  point  of  rupture.  To  prevent  this,  and  give  the  large  flat  surfaces  an  approxi- 
mate degree  of  strength  with  the  other  parts  of  the  boiler,  wrought  iron  or  copper 
stays,  one  inch  thick,  are  introduced ;  they  are  first  screwed  into  the  iron  and  cop- 
per on  both  sides  to  prevent  leakage,  and  then  firmly  riveted  to  the  interior  and  ex- 
terior plates.  These  stays  are  about  six  inches  asunder,  forming  a  series  of  squares, 
and  each  of  them  will  resist  a  strain  of  about  fifteen  tons  before  it  breaks. 
.  "  Let  us  now  suppose  the  greatest  pressure  contained  in  the  boiler  to  be  200  lbs.  on  the 


213 


square  inch,  and  we  have  6  x  6  x  200  =  7,200  lbs.,  or  S^^  tons,  the  force  applied  to  a 
square  of  36  inches.  Now  as  these  squares  are  supported  by  four  stays,  each  capable 
of  sustaining  fifteen  tons,  we  have  4  x  15  =  60  tons  as  the  resisting  powers  of  the 
stays,  but  the  pressure  is  not  divided  amongst  all  the  four,  but  each  stay  has  to  sustain 
that  pressure  ;  consequently  the  ratio  of  strength  to  the  pressure  will  be  as  4^  to  1 
nearly,  which  is  a  very  fair  proportion  for  the  resisting  power  of  that  part. 

"  VV  e  have  treated  of  the  sides,  but  the  top  of  the  fire-box  and  the  ends  have  also  to  be 
protected,  and  there  being  no  plate  but  the  circular  top  of  the  boiler  from  which  to  at- 
tach staj's,  it  has  been  found  more  convenient  and  equally  advantageous  to  secure  those 
parts  by  a  series  of  strong  wrought-iron  bars,  from  which  the  roof  of  the  fire-box  is  sus- 
pended, and  which  effectually  prevent  it  from  being  forced  down  upon  the  fire.  It  will 
not  be  necessary  to  go  into  the  calculations  of  those  parts ;  they  are,  when  riveted  to  the 
domo  or  roof,  of  sufficient  strength  to  resist  a  pressure  of  300  to  400  lbs.  on  the  square 
inclu  This  is,  however,  generally  speaking,  the  weakest  part  of  the  boiler,  with  the 
exception,  probably,  of  the  flat  end  above  the  tubes  in  the  smoke-box,  if  not  carefully 
stayed. 

"In  the  flat  ends  of  cylindrical  boilers,  and  those  of  the  marine  principle,  the  same 
rule  applies  as  regards  construction,  and  a  due  proportion  of  the  parts,  as  in  those  of 
the  locomotive  boilers,  must  be  closely  adhered  to.  Every  description  of  boiler  used 
in  manufactories,  or  on  board  of  steamers,  should  in  my  opinion  be  constructed  to  a 
bursting  pressure  of  400  to  600  lbs.  on  the  square  inch ;  and  locomotive  engine  boilers, 
which  are  subjected  to  a  much  severer  duty,  to  a  bursting  pressure  of  600^)  700  Iba. 
^  "It  now  only  remains  for  me  to  state  that  internal  flues,  such  as  contain  the  furnace 
m  the  interior  of  the  boiler,  should  be  kept  as  near  as  possible  to  the  cylindrical  form, 
and  as  wrought-iron  will  yield  to  a  force  tending  to  crush  it  about  one  half  of  what  would 
tear  it  asunder,  the  flues  should  in  no  case  exceed  one  half  the  diameter  of  the  boiler; 
and  with  the  same  thickness  of  plates  they  may  be  considered  equally  safe  with  the 
other  parts.  But  the  force  of  compression  is  so  different  from  that  of  tension,  that  I 
should  advise  the  diameter  of  the  internal  flues  to  be  in  the  ratio  of  1  to  2 i  instead  of 
1  to  2  of  the  diameter  of  the  boiler. 

"I  will  not  trouble  you  with  a  description  of  the  haycock,  hemispherical,  and  wagon- 
shape  boilers ;  they  are  all  bad  as  respects  their  powers  of  resistance,  and  ought  to  be 
entirely  disused:  I  shall  congratulate  the  public  when  they  disappear  from  the  list  of 
those  constructions  having  the  confidence  of  the  public,  and  the  consideration  of  the 
man  of  science  or  the  practical  engineer. 

"  1°  conclusion,  I  have  to  recommend  attention  to  a  few  simple  rules,  which,  if  care- 
fully observed,  will  lead  to  the  most  satisfactory  results.  To  construct  boilers  as  nearly 
as  possible,  of  maximum  strength,  I  have  already  observed  they  should  be  of  the  cy- 

!  i/I^^^V  "IV  ^"i  "^^^'u.  ^i  ^""^^  are  used,  they  should  be  composed  of  plates  one 
half  thicker  than  those  which  form  the  circumference.  The  flues,  if  two  in  number, 
to  be  of  the  same  thickness  as  the  exterior  shell ;  and  the  flat  ends  to  be  carefully  stayed 
^ith  gussets  of  triangular  plates  and  angle  iron,  firmly  connecting  them  with  the  cir- 
cumference, as  per  annexed  sketch. 
"The  use  of  gussets  I  earnestly  recommend,  as  being  infinitely  superior    to.   and 

more  certain  in  their  action  and  retaining  pow- 
ers, than  stay  rods.  Gussets,  when  used,  should 
I  be  placed  in  lines  diverging  from  the  centre  of 
fthe  boilers,  and  made  as  long  as  the  position 
of  the  flues  and  other  circumstances   in  the 
I  construction  will  admit     They  are  of  great 
value  in  retaining  the  ends  in  shape,  and  may 
safely  be  relied  upon  as  imparting  an  equali- 
ty of  strength  to  every  part  of  the  structure. 
With  these  observations,  I  would  direct  atten- 
tion to  the  facts  I  have  endeavored  to  incul- 
cate.    You  will,  I  am  persuaded,  find  them 
useful ;  and  I  trust  the  object  contemplated 
by  the  committee  of  your  valuable  Institution 
„,     .  -x  ,  ^^^1  **®   ^^^^y  attained,  in  the  acquisition  of 

greater  security  and  a  more  perfect  principle  of  construction."* 

1501LER8  (^-x^Wn*  o/).-."In  a  former  lecture  I  endeavored  to  explain  the  prin- 
ciples on  which  boilers  should  be  constructed,  and  the  laws  which  govern  the  strength 
and  other  properties  of  these  important  vessels.    The  subject  of  construction  is  onl  of 

tv  nV^'T  -^r^'  ^"."^  ^^''^''.  ^'*°™*  ^'•^^^  g'^«  ^^^  greatest  security  with  the  least  quanti- 
ly^of  material,  may  be  considered  as  the  safest  examples  for  imitation— the  true  elements 

MembS^'o^th^SnStS' o/'K^e''""'"""^^  ^^  ^""^  ^*''^^'  ^•'  ^  E.  F.  E.  8.  «id  Corres^ 


150 


I    ! 


214 


BOILERS. 


BOILERS. 


216 


I 


of  construcicon.  Boilers,  of  all  other  vessels,  require,  in  the  variety  of  their  conditions^ 
shapes,  and  dimensions,  the  study  of  the  philosopher  as  well  as  the  hands  of  the  me- 
chanic. They  contain,  within  comparatively  narrow  bounds,  a  force  which,  if  pro- 
perly governed,  will  propel  the  largest  and  most  stately  vessel  against  wind  and  tide  ; 
perform  the  work  of  a  tliousand  hand?,  and  drive  a  hundred  cars  loaded  with  hundreds 
of  tons,  at  the  speed  of  the  swiftest  race  horse,  from  one  extremity  of  the  kingdom  to 
the  other.  They  do  all  this  and  more;  they  impart  heat  and  comfort  to  our  dwellings, 
—are  essential  for  the  requirements  of  our  domestic  arrangements, — and  under  the 
control  of  judicious  management,  will  advance  the  interests  of  commerce,  and  contri- 
bute to  the  enjoyments  of  civilized  existence. 

"  Reverse  the  picture,  and  entrust  the  construction  and  management  to  the  hands  of 
incapacity  and  ignorance,  or  the  reckless  folly  and  hardihood  of  fancied  security,  and 
death  and  destruction  follow  as  a  result.  When  the  mischief  is  done,  we  then  begin 
to  guess  at  the  causes,  and  to  lament  the  inconsiderate  confidence  which  led  to  the 
employment  of  incompetency,  and  all  those  errors  of  judgment  which  invariably  pre- 
sent themselves,  not  before,  but  after  the  event  How  often  do  we  hear  of  the  most 
lamentable  accidents  terminating  in  the  destruction  of  life  and  property,  and  how 
often  do  we  lament  (when  too  late)  the  causes  which  led  to  those  frightful  catastro- 
phes !  All  these  accidents  might  be  prevented,  and,  instead  of  using  steam,  which  we 
now  do  in  our  manufactories,  at  a  pressure  of  5  to  20  lbs.  on  the  square  inch,  we  might 
witheoual  safety  use  it,  and  enjoy  the  advantage  of  its  superior  economy,  at  60  lbs.  on 
the  inch.  It  shall  be  my  duty  to  point  out  how  this  may  be  accomplished,  and  I  hope 
in  these  endeavors  to  have  the  support  of  every  well  wisher  for  increased  security  to 
the  public,  and  enlarged  economy  in  the  varied  requirements  of  the  use  of  steam. 

"  Before  I  attempt  a  solution  of  this  difficult  question,  I  would  first  direct  attention 
to  a  few  facta  which  bear  more  directly  upon  the  question  now  at  issue. 

"  Various  notions  are  entertained  as  to  the  causes  of  boiler  explosions,  and  scientific 
men  are  not  always  agreed  as  to  whether  they  arise  from  excessive  pressure  due  to  the 
accumulation  of  heat,  or  to  some  other  cause,  such  as  the  explosion  of  hydrogen  gas, 
generated  by  the  decomposition  of  water  suddenly  thrown  on  heated  plates,  of  which 
we  have  an  exceedingly  indefinite  conception.  That  of  the  decomposition  of  water  is,  I 
believe,  a  somewhat  prevalent  opinion,  but  I  apprehend  it  cannot  be  the  invariable 
cause,  inasmuch  as  in  that  case  we  must  assume  the  boiler  to  be  nearly  empty  of  water, 
and  the  plates  over  the  furnace  red  hot. 

"  It  is  not  unreasonable  to  suppose  that  a  force  of  such  sudden  origin,  and  so  imme< 
diate  and  destructive  in  its  effects,  should  suggest  the  presence  of  an  explosive  mix- 
ture; but  I  think  it  will  be  difficult,  if  not  impossible,  to  account  for  the  accumulation 
ofa  sufficient  quantity  of  hydrogen,  without  the  presence  of  oxygen  and  other  gases^ 
in  their  due  proportions,  to  form  an  explosive  compound.  Now  as  these  equivalents 
cannot  be  generated  all  at  once  by  the  simple  decomposition  of  water  (admitting,  for 
the  moment,  that  the  water  is  decomposed),  we  must  look  for  some  other  cause  for  the 
fatal  and  destructive  accidents  which  of  late  years  have  become  so  prevalent 

"  In  treating  of  this  subject,  I  hope  to  show  not  only  what  are  the  probable  causes  of 
explosions,  but,  what  appears  equally  important,  what  are  not  the  causes.  So  many 
theories  (some  of  them  exceedingly  problematical)  have  been  brought  forward  on  the 
occasion  of  disastrous  explosions,  that  it  requires  the  utmost  care  and  attention  to  cir- 
cumstances before  they  are  generally  admitted.  To  acquire  satisfactory  evidence  as 
to  the  precise  condition  of  the  boiler  and  furnace  before  an  explosion,  is  next  to  im- 
possible, as  most  frequently  the  parties  in  charge,  and  from  whose  mismanagement  and 
neglect  we  may,  in  many  cases,  date  the  origin  of  the  occurrence,  are  the  first  to  be- 
come the  victims  of  their  own  indiscretion,  and  we  can  only  judge  from  the  havoc  and 
devastation  that  ensues  as  to  the  immediate  cause  of  the  event 

"From  this  it  follows  that,  in  many  of  the  explosions  on  record,  few,  if  any,  of  the 
real  circumstances  of  the  case  are  made  known,  and  we  are  left  to  draw  conclusions 
from  the  appearances  of  the  ruptured  parts,  and  the  terrific  consequences  which  too 
frequently  follow  as  a  result  This  want  of  evidence  as  to  the  precise  condition  of 
a  boiler,  with  all  it«  valves  and  mountings,  preceding  an  explosion,  is  much  to  be  re- 
gretted, as  it  causes  a  degree  of  mystery  to  surround  the  whole  transaction ;  and  the 
vague  and  sometimes  inaccurate  testimony  of  witnesses  but  too  often  baffles  all  attempts 
at  research,  and  creates  additional  cause  of  alarm  to  all  those  exposed  to  the  occur- 
rence of  similar  dangers. 

"In  the  discussion  of  this  subject  I  shall,  however,  endeavor  to  trace,  from  a  number 
of  examples  in  which  I  have  been  personally  engaged,  and  from  others  which  have  come 
to  my  knowledge,  the  causes  which  have  led  to  those  disastrous  effects ;  and  provided 
I  am  successful  in  the  discovery  of  the  true  origin  of  the  majority  of  those  occurren- 
ces, we  shall  have  less  difficulty  in  devifling  and  applying  the  necessary  remediea  for 
their  prevention. 


**  In  my  attempts  to  ascertain  facts  by  a  course  of  reasoning  which  I  shall  have  to 
follow  in  this  investigation,  I  wish  it  to  be  understood  that  it  is  not  my  intention  to 
raise  doubts  and  fears,  in  the  public  mind,  calculated  to  arrest  the  progress  of  commer- 
cial enterprise,  or  to  cripple  the  energies  of  mechanical  skilL  On  the  contrary,  I  am 
most  anxious  to  promote  the  advancement  of  the  useful  arts,  to  increase  our  confi- 
dence in  the  application  of  increased  pressure,  and  to  secure  within  moderate  bounds 
the  economical  and  useful  employment  of  one  of  the  most  powerful  agents  ever  known 
in  the  history  of  practical  science.  My  object  in  this  inquiry  will,  therefore,  bo  to 
enlarge  our  sphere  of  action  by  a  more  comprehensive  knowledge  of  the  subject  on 
which  it  treats ;  to  induce  greater  caution  along  with  improved  construction  ;  and  to 
insure  confidence  in  all  those  requirements  essential  to  the  public  security. 

"  For  the  full  consideration  of  this  subject,  it  will  be  necessary  to  divide  it  into  the 
following  heads ; — 

**  1st  Boiler  explosions  arising  from  accumulated  internal  pressure. 

"2d.  Explosions  from  deficiency  of  water. 

*'  3d.  Explosions  produced  from  collapse. 

"4th.  Explosions  from  defective  construction. 

"  5tli.  Explosions  arising  from  mismanagement  or  ignorance ;  and 

"  6th.  The  remedies  applicable  for  the  prevention  of  these  accidenta. 

**ltt.  Boiler  explosions  arising  from  accumulated  internal  pressure. 

"  In  nine  cases  out  of  ten  a  continuous  increasing  pressure  of  steam,  without  the 
means  of  escape,  is  probably  the  immediate  cause  of  explosion;  in  some  instances  it 
arises  from  deficiency  of  water,  but  accidents  of  this  kind  are  comparativel}'^  few  in 
cumber,  as  we  often  find,  in  tracing  the  causes,  that  they  have  their  origin  in  undue 
pressure,  emanating  from  progressive  accumulation  of  steam  of  great  force  and  density. 
Let  us  take  an  example,  and  we  shall  find  that  a  boiler  under  the  influence  of  a  fur- 
nace in  active  combustion  will  generate  an  immense  quantity  of  steam ;  and  unless  this 
is  carried  off  by  the  safety-valve  or  the  usual  channels  when  so  generated,  the  greatest 
danger  may  be  apprehended  by  the  continuous  increase  of  pressure  that  is  taking  place 
within  the  boiler.  Suppose  that,  from  some  cause,  the  steam  thus  accumulated  does 
not  escape  with  the  same  rapidity  with  which  it  is  generated, — that  the  safety-valves 
are  either  inadequate  to  the  full  discharge  of  the  surplus  steam,  or  that  they  are  en- 
tirely inoperative,  which  is  sometimes  the  case, — and  we  have  at  once  the  clue  to  the 
injuiious  consequences  which,  as  a  matter  of  fact,  are  sure  to  follow.  The  event  may 
be  procrastinated,  and  repeated  trials  of  the  antagonistic  forces  from  within,  and  the  re- 
sistance of  the  plates  from  without,  may  occur  without  any  apparent  danger,  but  these 
experiments  often  repeated  will  at  length  injure  the  resisting  powers  of  the  material, 
and  the  ultimatum  will  be  the  arrival  of  the  fatal  moment  when  the  balance  of  the  two 
forces  is  destroyed,  and  explosion  ensues.  How  very  often  do  we  find  this  to  be  the 
true  cause  of  accidents  arising  from  extreme  internal  pressure,  and  how  very  easily 
these  accidents  might  be  avoided  by  the  attachment  of  proper  safety-valves,  to  allow 
the  steam  to  escape  and  relieve  the  boiler  of  those  severe  trials  which  ultimately  lead 
to  destruction]  If  a  boiler  whose  generative  power  is  equal  to  100,  be  worked  at  a 
pressure  of  10  lbs.  on  the  square  inch,  the  area  of  the  safety-valves  should  also  be  equal 
to  100,  in  order  to  prevent  a  continuous  increase  of  pressure ;  or,  in  case  of  the  adhesion 
of  any  of  the  valves,  it  is  desirable  that  their  areas  should,  collectively,  be  equal  to  IOOl 
If  two  or  more  valves  are  used,  100  or  120  would  then  be  the  measure  of  outlet*  Un- 
der these  precautions,  and  with  a  boiler  so  constructed,  the  risk  of  accident  is  greatly 
diminished ;  and,  provided  one  of  the  valves  is  kept  in  working  order  beyond  the 
reach  of  interference  by  the  engineer,  or  any  other  person,  we  may  venture  to  assume 
that  the  means  of  escape  are  at  hand,  irrespective  of  the  temporary  stoppage  of  the 
usual  channels  for  carrying  off  the  steam. 

"So  many  accidents  have  occurred  from  this  cause — the  defective  state  of  the  safety- 
valves — that  I  must  request  attention  whilst  I  enumerate  a  few  of  the  most  prominent 
eases  that  have  come  before  me.  In  the  year  1 845  a  tremendous  explosion  took  place  at 
a  cotton  mill  in  Bolton.  The  boiler.^  three  in  number,  were  situated  under  the  mill,  and, 
from  ttie  unequal  capacity  and  imperfect  state  of  the  safety-valves  (as  they  were  proba- 
bly fast),  a  terrible  explosion  of  the  weakest  boiler  took  place,  which  tore  up  the  plates 
along  the  bottom,  and,  the  steam  having  no  outlet  at  the  top,  not  only  burst  out  tlie  end 
next  the  furnace,  demolishing  the  building  in  that  direction,  but,  tearing  up  the  top  on 
the  opposite  side,  the  boiler  was  projected  upwards  in  an  oblique  direction,  carrying 
the  flours,  walls,  and  every  other  obstruction  before  it ;  ultimately  it  lodged  itself  across 
the  railway  at  some  distance  from  the  building.  Looking  at  the  disastrous  consequen- 
ces of  this  accident  and  the  number  of  persons  (from  16  to  18)  who  lost  their  lives  on 
tlie  occasion,  it  became  a  subject  of  deep  interest  to  the  community  that  a  close  in- 
vestigation should  immediately  be  instituted,  and  a  recommendation  followed  that  every 

««*'^K '*  "i*^  ^  ^^*,*^^  ^°  ®*^®'"  ^''orils.  viz.,  that  the  eenerative  powers  of  a  boiler  being  equal  to  a  iriy«a 
nomber  of  square  inches  of  area,  say  60,  the  area  of  the  safety-valve  should  also  bo  fiO. 


.2ie 


BOILERS. 


m 


i  M 


li 


precaution  should  be  used  in  the  construction  as  well  as  the  management  of  boil- 
ers. 

"  The  next  fatal  occurrence  on  record  in  this  district  was  a  boiler  at  Ashton-under- 
Lyne,  which  exploded  under  similar  circumstances,  namely,  from  excessive  interior 
pressure,  when  four  or  five  lives  were  lost ;  and  again  at  Hyde,  where  a  similar  acci- 
dent occurred  from  the  same  cause,  which  was  afterwards  traced  to  the  insane  act  of 
the  stoker  or  engineer,  who  prevented  all  means  for  the  steam  to  escape  by  tying  down 
the  safety-valve. 

"There  was  a  boiler  explosion  at  Malaga,  in  Spain,  some  years  since,  and  my  reason 
for  noticing  it  in  this  place  is  to  show  that  explosions  may  be  apprehended  from  other 
causes  than  those  enumerated  in  the  divisions  of  this  inquiry,  and  one  of  these  is  in- 
erustation.  Dr.  Ritterbrandt  says,  in  a  paper  read  before  the  Institution  of  Civil  En- 
gineers by  an  eminent  chemist,  Mr.  West — 'That  a  sudden  evolution  of  steam  under 
eircuinstanoes  of  incrustation  is  no  uncommon  occurrence.'  In  several  instances  I  have 
known  this  to  be  the  case,  particularly  in  marine  boilers,  where  the  incrustation  from 
salt  water  becomes  a  serious  grievance,  either  as  regards  the  duration  of  the  boiler, 
or  the  economy  of  fuel. 

"  If  it  were  supposed,  as  Dr.  Ritterbrandt  observes,  that  the  boiler  was  incrusted  to 
the  extent  of  half  an  inch,  it  would  at  once  be  seen  that  nothing  was  more  easy  than  to 
heat  the  boiler  strongly,  even  to  a  red  heat,  without  the  immediate  contact  of  water. 
Under  these  circumstances,  the  hardened  deposits,  being  firmly  attached  to  the  plates, 
andiorniing  an  imptrfoct  conductor  of  heat,  would  tend  greatly  to  increase  the  tempe- 
rature of  the  iron ;  and  the  difference  of  temperature,  thus  induced  between  the  iron  and 
the  incrustation,  and  the  greater  expansibility  of  the  iron,  would  cause  the  incrustation 
to  separate  from  the  plates,  and  the  water  rushing  in  between  them  would  generate  a 
considerable  charge  ot  highly  elastic  steam,  and  thus  endanger  the  security  of  the  boilers. 

"Tliese  phenomena  were  singularly  exemplified  in  the  Malaga  explosion,  which  in 
thus  described  by  Mr.  Hick; — 'I  have  ascertained  that  a  very  thick  incrustation  of 
salt  was  formed  on  the  lower  part  of  the  boiler,  immediately  over  the  fire,  and  so  far  as 
it  extended  the  plates  appear  to  have  been  red  hot,  being  thereby  much  weakened, 
and  hence  the  explosion.  The  ordinary  working  pressure  of  the  boiler  is  130  lbs.  per 
square  inch,  and  perhaps  at  the  time  of  the  explosion  \evy  much  above  that  pressure, 
as  there  was  only  one  small  safety-valve  of  two  and  a-half  inches  diameter.  The 
boiler  was  only  two  feet  six  inches  diameter,  and  twenty  feet  long.* 

*'  Incrustation,  exclusive  of  being  dangerous,  is  attended  with  great  expense  and 
mjury  to  the  boiler  by  its  removal.  In  the  case  of  the  transatlantic,  oriental,  or  other 
long  sea-going  vessels,  even  after  the  use  of  brine-pumps,  blowing  out,  Ac.,  a  very 
large  amount  of  incrustation  is  formed,  and  considerable  sums  of  money  are  expended 
each  voyage  to  remove  it. 

"  Other  explosions  of  a  more  recent  date  are  those  which  occurred  at  Bradford  and 
Halifax.  They  are  still  fresh  in  the  recollection  of  the  public  mind,  and  are  so  well 
known  as  not  to  require  notice  in  this  place. 

"I  cannot,  however,  leave  this  part  of  the  subject  without  reverting  to  an  accident 
which  occurred  on  the  Lancashire  and  Yorkshire  Railway,  whichhad  its  origin  in  the 
same  cause — excessive  internal  pressure.  This  accident  is  the  more  peculiar  as  it  led 
to  along  mathematical  disquisition  as  to  the  nature  of  the  forces  which  produced  results 
at  once  curious  and  interesting.  The  conclusions  which  I  arrived  at,  although  practi- 
cally right,  were,  however,  considered  by  some  mathematically  wrong,  as  they  weie  firm- 
ly combated  by  several  eminent  mathematicians;  but  notwithstanding  the  number  of 
sJgebraic  formulas  and  the  learned  discussions  of  my  friends  on  that  occasion,  I  have 
been  unable  to  change  the  opinions  I  then  formed,  for  others  more  conclusive. 

•'The  accident  here  alluded  to  occurred  to  the  'Irk'  locomotive  engine,  which,  in 
February,  1745,  blew  up  and  killed  the  driver,  the  stoker,  and  another  person  who  was 
standing  near  the  spot  at  the  time.  A  great  difference  of  opinion  as  to  the  cause  of  this 
accident  was  prevalent  in  the  minds  of  those  who  witnessed  the  explosion,  some  attri- 
buting it  to  a  crack  in  the  copper  fire-box,  and  others  to  the  weakness  of  the  stays  over 
the  top.  Neither  of  these  opinions  was,  however,  correct,  as  it  was  afterwards  demon- 
strated that  the  material  was  not  only  entirely  free  from  cracks  and  flaws,  but  the  stays 
were  proved  suflicient  to  resist  a  pressure  of  150  to  200  lbs.  on  the  square  inch.  The  true 
cause  was  afterwards  asceitained  to  arise  from  the  fastening  down  of  the  safety-valve  of 
the  engine  (an  active  fire  being  in  operation  under  the  boiler  at  the  time),  which  wa» 
under  the  shed,  with  the  steam  up,  ready  to  start  with  the  early  morning  train.  The  ef- 
fect of  this  was  the  forcing  down  of  the  top  of  the  copper  fire-box  upon  the  blazing  em- 
bers of  the  furnace,  which,  acting  upon  the  principle  of  the  rocket,  elevated  the  boiler 
and  engine  of  20  tons  weight  to  a  height  of  30  feet,  which,  in  its  ascent  made  a  summerset 
in  the  air,  passed  through  the  roof  of  the  shed,  and  ultimately  landed  at  a  distance  of  60 
yards  from  its  original  position.  The  question  which  excited  most  interest,  was  the  ab» 
solute  force  required  to  fracture  the  fire-box,  its  peculiar  properties  when  once  liberated. 


BOILERS. 


217 


and  the  elastic  or  continuous  powers  in  operation  which  forced  the  engine  from  its  place 
to  an  elevation  of  30  feet  from  the  position  in  which  it  stood.  An  elaborate  mathe- 
matical discussion  ensued  relative  to  the  nature  of  these  forces,  which  ended  in  the 
opinion  that  a  pressure  suffieient  to  rupture  the  fire-box,  was,  by  its  continuous  action, 
sufficient  to  elevate  the  boiler  and  produce  the  results  which  followed.  Another  rea- 
son was  assigned,  namely,  that  an  accumulated  force  of  elastic  vapor,  at  a  high  tem- 
perature, with  no  outlet  through  the  valves,  having  suddenly  burst  upon  the  glowing 
embers  of  the  furnace,  would  charge  the  products  of  combustion  with  their  equivalents 
of  oxygen,  and  hence  explosion  foTlowedi  Whether  one  or  both  of  these  two  causes 
were  in  operation  is  probably  difficult  to  determine ;  at  all  events,  we  have  in  many 
instances  precisely  the  same  results  produced  from  similar  causes,  and  unless  greater 
precaution  is  used,  in  the  prevention  of  excessive  pressure,  we  may  naturally  expect 
a  repetition  of  the  same  fatal  consequences. 

"The  preventives  against  accidents  of  this  kind  are,  well-constructed  boilers  of  the 
strongest  form,  and  duly  proportioned  safety  valves;  one  under  the  immediate  con- 
trol of  the  engineer,  and  the  other,  as  a  reserve  under  the  keeping  of  some  competent 
authority. 

"  ^d.  Erplodons  by  deficiency  of  water. 

"This  division  of  the  subject  requires  the  utmost  care  and  attention,  as  the  circum- 
stance of  boilers  being  short  of  water  is  no  unusual  occurrence.  Imminent  danger 
frequently  arises  from  this  cause;  and  it  cannot  be  too  forcibly  impressed  upon  the 
minds  of  engineers,  that  there  is  no  part  of  the  apparatus  constituting  the  mountings 
of  a  boiler  which  require  greater  attention — probably  the  safety-valves  not  excepted 
— ^tiian  that  which  supplies  it  with  water.  A  well-constructed  pump,  and  self-acting 
feeders,  when  boilers  are  worked  at  a  low  pressure,  are  indispensable ;  and  where  the 
latter  cannot  be  applied,  the  glass  tubular  gauge,  steam,  and  water  cocks  must  have 
more  than  ordinary  attention. 

"  In  a  properly  constructed  boiler  every  part  of  the  metal  exposed  to  the  direct  action 
of  the  fire  should  be  in  immediate  contact  with  the  water,  and,  when  proper  provision 
is  made  to  maintain  the  water  at  a  sufficient  height  above  the  part  of  the  plates  so 
exposed,  accidents  can  never  occur  from  this  cause. 

"Should  the  water,  however,  get  low  from  defects  in  the  pump,  or  any  stoppage  of 
the  regulating  feed  valves,  and  the  plates  over  the  furnace  become  red  hot,  we  then 
risk  the  bursting  of  the  boiler,  even  at  the  ordinary  working  pressure.  We  have  no 
occasion,  under  such  circumstances,  to  search  for  another  cause,  from  the  fact  that  the 
material  when  raised  to  a  red-heat  has  lost  about  five-sixths  of  its  strength,  and  a  force 
of  less  than  one-sixth  will  be  found  amply  sufficient  to  bear  down  the  plates  direct  upon 
<  the  fire,  or  to  bui*st  the  boiler. 

"  When  a  boiler  becomes  short  of  water,  the  first,  and  perhaps  the  most  natural, 
action  is  to  run  to  the  feed  valve,  and  pull  it  wide  open.  This  certainly  remedies  the 
deficiency,  but  increases  the  danger,  by  suddenly  pouring  upon  the  incandescent  plates 
a  large  body  of  water,  which,  coming  in  contact  with  a  reservoir  of  intense  heat,  is 
calculated  to  produce  highly  elastic  steam.  This  has  been  hitherto  controverted  by 
several  eminent  chemists  and  philosophers ;  but  I  make  no  doubt  such  is  the  case, 
unless  the  pressure  has  forced  the  plates  into  a  concave  shape,  which  for  a  time  would 
retard  the  evaporization  of  the  water  when  suddenly  thrown  upon  them.  Some 
curious  experimental  facts  have  been  elicited  on  this  subject,  and  those  of  M.  Boutigny, 
and  Professor  Bowman,  of  King's  College,  London,  show  that  a  small  quantity  of  water 
projected  upon  a  hot  plate  does  not  touch  it;  that  it  forms  itself  into  a  globule  sur- 
rounded with  a  thin  film,  and  rolls  about  upon  the  ])late  without  the  least  appearance 
of  evaporation.  A  repulsive  action  takes  place,  and  these  phenomena  are  explained 
upon  the  supposition  that  the  spheroid  has  a  perfectly  reflecting  surface,  and  conse- 
quently the  heat  of  the  incandescent  plate  is  reflected  back  upon  it  What  is,  how- 
ever, the  most  extraordinary  in  these  experiments,  is  the  fact  that  the  globule,  whilst 
rolling  upon  a  red  hot  plate,  never  exceeds  a  temperature  of  about  204°  of  Fahr. ;  and 
in  order  to  produce  ebullition,  it  is  necessary  to  cool  the  plate  until  the  water  begins 
to  boil,  when  it  is  rapidly  dissipated  in  steam. 

"The  experiments  by  the  committee  of  the  Franklin  Institute  on  this  subject,  give 
some  interesting  and  useful  results.  That  committee  found  that  the  temperature  at 
which  clean  iron  vaporized  drop  of  water  was  334°  of  Fahr.  The  development  of  a 
repulsive  force  which  I  have  endeavored  to  describe  was,  however,  so  rapid  above  that 
temperature,  that  drops  which  required  but  one  second  of  time  to  disappear  at  the 
temperature  of  maximum  evaporation,  required  152  seconds  when  the  metal  was  heated 
to  395°  of  Fahr.  The  committee  go  on  to  state  that — '  One  ounce  of  water  introduced 
into  an  iron  bowl  three-sixteenths  of  an  inch  thick,  and  supplied  with  lieat  by  an  oil- 
bath,  at  the  temperature  of  546°,  was  vaporized  in  fifteen  seconds,  while,  at  tlie  initial 
temperature  of  507°,  that  of  the  most  rapid  evaporization  was  thirteen  seconds.* 


A 


iijt  li 


'£i^ 


'In 


!    \U 

•     It  ■ 


218 


BOILERS. 


sav  lorn  n?lT^  however,  hold  good  in  every  case,  as  an  increased  quantity  of  water 
Bay  from  one-eighth  of  an  ounce  to  two  ounces,  thrown  UDon  heated  nlai^.?;  ^^t ' 
temperature  of  vaporization  from  460°  to  600°  Fah^    Zs  clar^v  stt;./],  f.K^ 

"  Sd.  Axploswns  produced  from  collapse 
circumstance  of  thrtJnS!.^  J  and  destroyed  and  scalded  every  thing  before  it   A 

mmMMmm 

deficieneyV  wS  in  thf  toiler  '  '"'^^•''"*  treated,-explosio„s  from  a 

forms.  generated  by  it  produces  death  m  one  of  its  worst  and  most  painful 

..TK-  ^'^P^'^'l^'^'/^oyn  defective  construction. 

attention;  anTon'^^il^t'shtlirmv"  ^^T^^^^"^  '^'''  '^^  P^^'^  -^^^^  our 

already  shown  the  nature  o^the  stS  anl^th "^  'ir^'^f '     ^^  ^  P''^^^""«  ^"^"^^^  ^  ^^^« 

usedin^he  constructionTboiler^l^LbL^^^^^^ 

shown  the  distribution  and  pSn  in  whrch  fh;f  I,  *^?7  ««♦,  however,  in  all  cases 

to  attain  the  maximum  of  st^en^h  and  ^S^  '^^"^^  ^^  placed  in  order 

sisting  powers  of  vessels  suS  sompHr^^^''^''**''  '"'""'^  ^°  '^'  '^' 

subject  ^f  such  importance  tCt  I  sll  iTe  rdtr X^^^^^^^^^^^^  ™'  ''  * 

time,  in  endeavoring  to  point  out  the  advanWes  pecuffi^^^^ 

sound  and  perfect  system  of  construction         ^     Peculiar  to  form,  and  the  use  of  a 

^e/e2^''^n:LlW^^^^^  -<i  wagon-shaped  boilera 

g        a  y  m  use ,  and  it  was  not  until  high  pressure  steam  was  first  intro- 


3ILERS. 


219 


duced  into  Cornwall,  that  tho  cylindrical  form  with  hemispherical  ends,  and  the  furnace 
under  the  boiler,  came  into  use.  Subsequently  this  gave  way  to  the  introduction  of  a 
large  internal  flue  extending  the  whole  length  of  the  boiler,  and  in  this  the  furnace 
was  placed.  For  many  years  this  was  the  best  and  most  economical  boiler  in  Corn- 
wall, and  its  introduction  into  this  country  has  effected  great  improvements  in  the 
economy  of  fuel  as  well  as  the  strength  ot  the  boiler.  Several  attempts  have  been 
made  to  improve  this  boiler  by  cutting;  away  one  half  of  the  end,  in  order  to  adoiit  a 
larger  furnace.  This  was  first  done  by  the  Butterley  Company,  and  it  since  has  gone 
by  the  name  of  the  Butterley  boiler.  This  construction  has  the  same  defects  as  tho 
haycock  or  hemispherical  and  wagon-shaped  boilers :  it  is  weak  over  the  fire-place,  and 
cannot  well  be  strengthened  without  injury  to  the  part  A^Jig.  161,  of  the  boiler,  fronc 


the  vast  number  of  stays  necessary  to  suspend  the  part  which  forms  the  canopy  of  th^ 
furnace.  Of  late  years  a  much  greater  improvement  has,  however,  been  effected  bv  the 
double  flue,  b  h,fig.  152,  and  double  furnace  boiler,  which  is  now  in  general  use,  and  has 
nearly  superseded  all  the  other  constructions.  It  consists  of  the  cylindrical  form,  vary- 
ing from  five  to  seven  feet  in  diameter,  with  two  flues  which  exten'd  the  whole  length  of 
the  boiler ;  thev  are  perfectly  cylindrical,  and  of  sufficient  magnitude  to  admit  a  furnace 
in  each.  This  boiler  is  the  simplest,  and  probably  the  most  effective,  that  has  yet  been 
constructed.  It  presents  a  large  flue  surface  as  the  recipient  of  heat,  and  the  double  flues, 
when  riveted  to  the  flat  ends,  add  greatly  to  the  security  and  strength  of  those  parts. 
It,  moreover,  admits  of  the  new  process  of  alternate  firing,  so  highly  conducive  to  per- 
fect combustion,  and  the  prevention  of  the  nuisance  of  smoke.— i^mViafrn  and  Hether- 
ington' s  patent  of  April  30,  1844. 

"Another  boder,  into  which  a  number  of  small  tubes  are  introduced,  exhibits  a  pow- 
erful generator  of  steam,  from  the  extent  of  its  flue  surface,  and  the  facility  with  which 
the  repairs  can  be  effected.  It  does  not  present  any  greater  security  a^inst  explosion 
than  the  boiler  with  two  flues,  but  its  construction  on  the  tubular  sjstem  effects  a 
great  saving  in  space,  and  is  otherwise  productive  of  all  the  advantages  of  economy  in 
the  consumption  of  fuel  and  the  prevention  of  smoke.  Tliis  boiler  is  constructed  with 
a  large  internal  flue,  divided  in  the  middle,  which  admits  of  two  fire-places  and  alter- 
nate firing.  In  the  space  which  I  call  the  mixing  chamber,  the  products  of  combustion 
amalgamate,  and  are  thus  ignited  before  they  enter  the  tubes,  and  from  which  they 
issue  into  the  end  flues,  and  from  thence  to  the  chimney  in  the  usual  way.  In  this 
latter  construction  it  will  be  observed  that  the  boiler  is  of  the  same  form  as  the  last, 
and  contains  the  same  elements  of  strength  as  the  double-flue  boiler,  the  only  diff'erence 
being  a  combination  of  the  locomotive  and  marine  tubular  system,  which  contains  a 
large  absorbent  heating  surface  in  a  small  space. 

"It  will  not  be  necessary  to  multiply  examples  of  construction,  as  I  have  already  de- 
scribed those  which  I  consider  best  calculated  to  sustain  severe  pressure.  At  the  same 
time,  when  the  parts  are  judiciously  and  skilfully  arranged,  with  a  grate-bar  surface 
well  proportioned  to  the  amount  of  flue-surface  as  the  recipient,  we  may  reasonably 
conclude  that  we  are  not  far  from  the  maximum  of  strength,  including  other  important 
elements  in  the  material  and  the  consumption  of  fuel. 

"The  means  necessary  to  be  employed  for  the  prevention  of  accidents  in  this  depart- 
ment of  the  inquiry,  are  a  knowledge  of  the  principles  of  construction,  and  an  acquaint- 
ance with  the  strength  and  properties  of  the  materials  used  for  that  purpose. 

5th.  Explosions  arising  from  mismanagement  or  ignorance. 
,  "To  mismanaij:ement,  ignorance,  and  the  misapplication  of  a  few  leading  principles 
in  connection  witli  the  use  and  application  of  steam,  may  be  traced  the  great  majority 
of  accidents  which  from  time  to  time  occur.  Many  of  these  accidents,  so  fruitful  of  the 
destruction  of  property  and  human  life,  might  be  prevented  if  we  had  well  constructed 
vessels,  judiciously  united  to  skill  and  competency  in  the  management.  To  convey  a 
lew  practical  instructions  to  engineers,  stokers,  an^  engine-men,  would  be  an  undertak- 
ing  of  no  great  difiiculty  A  young  man  of  ordinary  capacity  would  learn  all  that  is 
necessary  in  a  few  months ;  and  if  placed  under  competent  Instructors,  he  might  be 
made  acquainted  with  the  properties  of  steam— its  elastic  force  at  different  degrees  of 
pressure— the  advantages  peculiar  to  sensitive  and  easy  working  safety  valves— tho 


I  • ... 


220 


BOILERS. 


BOILERS. 


221 


!«•: 

■*"! 


ill 


necessity  of  cleanliness  and  keeping  them  in  good  working  condition— the  use  of  water 
gauges,  fusion  plugs,  indicators,  signals,  Ac,  Ac,  connected  with  the  supply  and  height 
ot  water  in  the  boiler— the  dangers  to  be  apprehended  from  a  scarcity  of  water-the 
danger  of  explosion  when  the  engine  is  standing,  or  when  the  usual  channels  for  reliev- 
ing the  boiler  of  its  surplus  steam  are  stoppod.  All  these  are  parts  of  elenientarv  in- 
struc-tion  which  the  stoker,  as  well  as  the  engineer,  should  be  acquainted  with  •  and  no 
proprietor  of  a  mill,  captain  of  a  steamship,  or  superintendent  of  locomotives  should 
give  employment  to  any  persons  unless  they  can  produce  certificates  of  good  behavior 
and  a  knowledge  of  the  elementary  principles  of  their  profession 

"If  these  precautions  were  adopted,  greater  care  observed  in  the  selection  of  men 
of  skill  and  responsibility  m  the  construction  of  boilers,  and  a  more  strict  and  rigid 
code  of  laws  in  the  management,  we  might  look  forward  with  greater  certainty  to 
a  considerable  dimimition  if  not  a  prevention,  of  those  calamitous  events  which  so 
frequently  plunge  whole  famihes  into  mourning  by  unexpected  and  instantaneous 

"As  an  individual,  I  would  cheerfully  lend  my  best  assistance  to  the  development 
of  a  principle  of  instruction  calculated  to  relieve  the  country  of  the  i-norance  which 
pervades  hat  part  of  the  community  on  which  the  lives  of  so  many  depend  A  res^ 
lution  on  the  part  of  those  who  empfoy  persons  of  this  description,  and  whose  interesto 
thl  'rl^J^i^P  f  "^  ^^  ''5"  only  those  whose  knowledge  and  character  come  up  to 
the  requisite  standard,  a,id  pay  far  it,  would  soon  cause,  from  the  economy  of  the 
management,  and  the  increased  security  of  their  property,  a  very  important  change  in 
all  the  requirements  of  the  economy,  as  well  as  the  apptteation,  of  steam.     How  fften 

?n^r\^VT/r'''^'^^^^"^^''  ""i^  "'^^^^^'«  containing  the  elements  of  destruction 
in  the  hands  of  the  most  ignorant  and  reckless  practitioners,  whose  insensibility  to  dan- 
ger, and  total  incompetency  to  judge  of  its  presence,  render  them  above  all  others  the 
most  unfit  to  be  employed.     And  why  ?     Because  they  are  the  very  persons,  from  their 
defective  knowledge  to  increase  the  danger  and  aggravate  the  evils  they  w^re  selected 
to  prevent    It  is  not  the  hrst  time  that  engineer.,  to  secure  (if  I  may  use  the  expreSon) 
an  insane  pressure,  have  fastened  the  safety  valves,  and  screwed  down  the  steam  vXe^ 
closing  every  outlet,  without  ever  thinking  of  the  fire  that  was  blazing  under  the  boiW 
Under  such  circumstances  what  could  be  expected  but  a  blow  up?     A  madman  rush- 
ing with  a  lighted  match  into  a  powder  magazine  could  not  act  with  greTr  insan^  y 
Such,  however,  has  been  the  case,  and  all  arising  from  want  of  thoiight.  or  what  « 

:eT^'ireif%rit^^^^^^^^^^         ^"^'^^ ''  ™ «-  '^'y  ofL\::^i:y:r: 

"I  have  on  former  occasions  stated  that  I  am  not  an  advocate  for  legislative  inter- 
ference either  in  the  construction  or  management  of  boilers;  but.  seeing^  he  din  ger;^^^^ 
tendency  of  these  vessels  when  placed  under  the  control  of  ignorance  and  inrn^itTl 
would  forego  many  considerations  to  encourage  a  more  j  idfciorandTntSnt  cl^ia 
of  men  than  has  hitherto  been  employed  in  the  care  and  inanagement  of  steam  and  the 
6  earn  engine  The  reforms  necessary  to  be  introduced  may  he  made  by  theTwners  of 
steam  engines,  steamboats,  railways,  and  others  engaged  in  the  use  anla^^hZth^  of 
this  important  element  A  desire  to  enforce  more  judicious  and  stringent  re^g^^^^^^^^^ 
Lr'?  f  talent  and  to  employ  only  those  whose  good  conduct  afd  smferior  kno^ 
pelVof Se  ImXr  ^'"'^  "  ''^  ^"^^  ^"^^  ^^^^^^^^  «^P"^"«  safety ^aTthe^ro" 
Jni^^^^^'  ^^'  '■^'''^''*  a;>/>/tca6/.  for  the  prevention  of  accidents  arising  from  expl<^ 

«;nl??/l°^  '^''^'^^^  '"  ^^^  foregoing  remarks  most  of  the  causes  incident  to  boiler  exolo. 
sions,  It  now  only  remains  to  draw  such  inferences  as  will  point  out  the  circ  imstonc^ 
which  It  IS  desirable  to  cultivate,  and  others  which  it  is  desirable  to  avoid  ThL! 
circumstances  I  have  endeavored  to  class  in  such  a  way  as  to  bring  tl^e  subieclor^^ 
mmently  forward,  and  to  point  out  under  each  head  fir<;t  tl,P  p«„=1  i  •  1 1  J!  ^  - 
dent;  and,  secondly,  the  Sieans  necessary  to  be  obJer^^^^^^ 
summary,  it  may  not  be  inexDedient  hrl^fl^  f«  ^^«!.I-*  i  *     ?il    ^  in  a  general 

loys  of  tin  ana  lead,  with  a  small  portion  of  Lm„th  [nTu'h  proL.^  ^  •>?  "*  "'^ 
fusion  at  a  tcmperatupo  sometliing  beW  that  of  moltenTa/  K  '  "'.r'"  '"'""■« 
importance  is  attached  to  these  alloys,  and,  in  o  °de"to  cLure  c.rt."  ♦  """t  '?..'  ^'^^ 
proportions,  the  plates  are  prepareVat  the  royal  mint  Ther^f^y  "  *,"  ""*'  '^f ""« 
Suly  prepared  for  use.  In  thir  country  the^\noT  arl  no?  ^IjrllJf ^  '"  P"?""*'! 
this  respect  I  think  we  are  wron^  as  boiler  explo^{L\™"n°«\rfre;'l;r^^t « 


in  this  country,  and  high-pressure  steam,  from  its  superior  economy,  is  more  extensively 
used  in  France  than  in  England.  In  my  own  practice  I  invariably  insert  a  lead  rivet, 
one  inch  in  diameter,  immediately  over  the  fireplace,  and  as  common  lead  melts  at  620°, 
I  have  invariably  found  these  metallic  plugs  a  great  security  in  the  event  of  a  scarcity  oi 
water  in  the  boiler.  I  am  persuaded  many  dangerous  explosions  may  be  avoided  by  the 
use  of  this  simple  and  effective  precaution  ;  and  as  pure  lead  melts  at  610°  we  may  infer 
from  this  circumstance  that  notice  will  be  given  and  relief  obtained  before  the  internal 
pressure  of  the  steam  exceeds  that  of  the  resisting  powers  of  the  heated  plates.  As  this 
simple  precaution  is  so  easily  accomplished,  I  would  advise  its  general  adoption.  It 
can  do  no  harm  to  the  boiler,  and  may  be  the  means  of  averting  explosions  and  the 
destruction  of  many  valuable  lives. 

*•  The  fusible  metal  plates,  as  used  in  France,  are  generally  covered  by  a  perforated 
metallic  disc,  which  protects  the  alloy  of  which  the  plate  is  composed,  and  allows  it  to 
ooze  through  as  soon  as  the  steam  has  attained  the  temperature  necessary  to  insure  the 
fusion  of  the  plate.  The  nature  of  the  alloy  is.  however,  somewhat  curious,  as  the  dif- 
ferent equivalents  have  different  degrees  of  fluidity,  and  the  portion  which  is  the  first  to 
melt  is  found  out  by  the  pressure  of  the  steam  causing  the  adhesion  of  the  less  fusible 
parts,  but  in  a  most  imperfect  state,  and  incapable  of  resisting  the  internal  force  of  the 
steam.  The  result  of  these  compounds  is  the  fusion  of  one  portion  of  the  alloy  and  the 
fracture  of  the  other,  which  is  generally  burst  by  pressure. 

"This  latter  description  of  fusible  plates  is  different  from  the  lead  plug  over  the  fire, 
which  is  fused  at  600°  by  the  heat  of  the  furnace,  and  the  other,  by  the  temperature 
of  the  steam,  when  raised  to  the  fusible  point  of  the  alloy,  which  varies  from  280°  to 

860°. 

"Another  method  is  the  bursting  plate,  fixed  in  a  frame  and  attached  to  some  con- 
venient part  of  the  upper  side  of  the  boiler ;  this  plate  is  to  be  of  such  thickness  and  of 
Buch  ductility  as  to  cause  rupture  whenever  the  pressure  exceeds  that  of  the  weight  oa 
the  safety  valve.  There  can  be  no  doubt  that  such  an  apparatus,  if  made  with  a  sufii  • 
ciently  large  opening,  would  relieve  the  boiler ;  but  the  objections  to  this  and  several 
other  devices  are  the  frequent  bursting  of  those  plates,  and  the  effect  every  change  of 
pressure  has  upon  the  material  in  reducing  its  powers  of  resistance,  and  thus  increasing 
uncertainty  as  to  the  amount  of  pressure  in  the  boiler,  as  well  as  the  constant  renewal 
of  the  plates. 

"  It  has  already  been  noticed  that  one  of  the  most  important  securities  against  ex- 
plosions is  a  duly  proportioned  boiler,  well  constructed ;  and  to  this  must  be  added 
ample  means  for  the  escape  of  the  steam  on  every  occasion  when  the  usual  channels  have 
been  suddenly  stopped.  The  only  legitimate  outlets  under  these  circumstances  appear 
to  me  to  be  the  safety-valves,  which,  connected  with  this  inquiry,  are  indispensable  to 
security.  Every  boiler  should,  therefore,  have  two  safety-valves,  of  sufficient  capacity 
to  carry  off  the  quantity  of  steam  generated  by  the  boiler.  One  of  these  valves  should 
be  of  the  common  construction,  and  the  other  beyond  the  reach  of  the  engineer  or  Any 
other  person. 

"  Fig.  153  is  a  sketch  of  a  lock-up  safety-valve,  as  constructed  by  Mr.  Fairbairn.  a  is 
the  valve,  b  is  a  shell  of  thin  brass,  opening  on  an  hinge  and  secured  by  a  padlock  ;  it 
18  of  such  a  diameter  as  to  allow  the  waste  steam  to  escape  in  the  direction  of  the  arrows. 

c  is  the  weight,  which  may  be 
fixed  at  any  part  of  the  lever 
to  give  the  desired  amount  of 
pressure,  but  which  cannot  be 
fixed  or  altered  unless  the 
boiler  is  opened  to  allow  a 
man  to  get  inside.  d  is  a 
handle,  having  a  long  slot,  by 
which  the  valve  may  be  re- 
lieved or  tried  at  any  time,  to 
obviate  the  liability  of  its  cor- 
roding or  being  jammed;  the 
engineer  cannot,  however,  put 
any  additional  weight  upon 
the  valve  by  this  handle. 

"Whilst  tracing  the  causes 
of  explosions  from  a  deficiency 
of  water  in  the  boiler,  I  have  recommended  aa  the  usual  precautions,  ^ood  pumps,  sell- 
acting  feeders,  water  cocks,  gla^s  gauges,  floats,  alarms,  and  other  indicators  which 
mark  the  changes  and  variutioas  in  th«  height  of  the  water.  To  these  may  be  added 
the  steam  wliistlc,  but  chiefly  tlie  constant  inspection  of  a  careful,  sober,  and  ju- 
dicious engineer.     Above  all  o'^hei*  -ncaris  however  ingeniously  devised,  this  is  the  most 


153 


i 


222 


BOILERS. 


BONES. 


228 


r. 


It-  ■ 


:'.M 


'Tf 


» 


I         i 


it 


II    : 


i' 


r   . 


essential  to  security,  for  on  that  official  depends,  not  only  the  security  of  the  property 
under  his  charge,  but  also  the  interests  of  his  family,  and  the  lives  of  all  those  within 
the  immediate  influence  of  his  operations.  One  of  the  most  important  considerations 
in  this  and  every  other  department  of  management  is  cleanliness  and  the  careful  atten- 
tion of  a  good  sober  engineer. 

"  Explosions  produced  from  collapse  have  their  origin  in  different  causes  to  those 
arising  from  a  deficiency  of  water,  and  the  only  remedy  that  can  be  applied  is  the 
vacuum  valve  and  the  cylindrical  or  spheroidal  form  of  boiler. 

"  Defective  construction  is  unquestionably  one  of  the  greatest  sources  of  the  frightful 
accidents  which  we  are  so  frequently  called  upon  to  witness.  Ko  man  should  be  alFowed 
unlimited  exercise  of  judgment  on  a  question  of  such  vital  importance  as  the  construc- 
tion of  a  boiler,  unless  duly  qualified  by  matured  expenence  in  the  theoretical  and 
practical  knowledge  of  form,  strength  of  materials,  and  other  requirements  requisite 
to  insure  the  maximum  of  sound  construction.  It  appears  to  me  equally  important 
that  we  should  have  the  same  proofs  and  acknowledged  system  of  operations  in  the 
construction  of  boilers,  as  we  have  in  the  strength  and  proportions  of  ordnance.  In 
both  cases  we  have  to  deal  with  a  powerful  and  dangerous  element;  and  I  have  yet 
to  learn  why  the  same  security  should  not  be  given  to  the  general  public  as  we  find 
so  liberally  extended  to  an  important  branch  of  the  public  service.  In  the  ordnance 
department  at  Woolwich  (with  which  I  have  been  more  or  less  connected  for  some 
years)  the  utmost  care  and  precision  is  observed  in  the  manufacture  of  guns;  and  the 
proofs  are  so  carefully  made  under  the  superintendence  of  competent  officers,  as  to 
render  every  gun  perfectly  safe  to  the  extent  of  1000  to  1200  rounds  of  shot. 

"Boilers  and  artillery  are  equally  exposed  to  fracture,  and  it  appears  to  me  of  little 
moment  whether  the  one  is  burst  by  the  discharge  of  gunpowder,  or  the  other  by  the 
elastic  force  of  steam. 

"Taking  into  consideration  all  the  circumstances  connected  with  the  bursting  of 
boilers  and  the  bursting  of  guns,  and  looking  at  the  active  competition  which  exists, 
and  is  likely  to  be  extended,  in  manufactories,  railway  traffic,  and  steam  navigation, 
rendering  it  every  day  more  desirable  to  reduce  the  cost  by  an  extended  use  of  steam 
at  a  much  higher  pressure,  it  surely  becomes  a  desideratum  to  secure  the  public  safety 
by  the  introduction  of  some  generally  acknowledged  system  of  construction  that  wiU 
bear  the  test  of  experience,  and  involve  a  maximum  power  of  resistance.  The  most 
elaborate  disquisitions  have  taken  place,  by  the  most  distinguished  men  of  all  ages 
since  the  invention  of  gunpowder,  to  discover  the  strength  and  form  of  guns  of  every 
description.  tSurely  boilers  are  equally  if  not  more  important,  as  the  sacrifice  of  human 
life  appears  to  me  much  greater  in  the  one  case  than  the  other.  It  is  therefore  a  sub- 
ject of  paramount  importance  to  the  public  to  know  that  the  facts  of  scientific  inquiry, 
and  the  knowledge  of  practical  skill,  have  combined  to  give  undeniable  security  as  well 
as  confidence,  that  boilers  are  properly  constructed,  and  capable  of  bearing  at  least  »ix 
times  their  working  pressure. 

"  On  the  question  of  explosions  arising  from  mismanagement  and  ignorance,  we  have 
little  further  to  add ;  and  it  now  only  remains  to  state,  that  the  subject  of  security  from 
boiler  explosions  is  of  such  importance  as  to  call  for  more  able  exponents  than  mj'self. 
I  have  endeavored  to  trace  the  causes  of  these  lamentable  occurrences,  and  to  draw 
such  deductions  therefrom  as  I  trust  may  be  useful  in  at  least  mitigating,  if  not  almost 
entirely'  averting,  the  danger. 

"  I  repeat  the  means  of  prevention  and  the  precautions  necessary  to  be  observed  in 
the  construction  and  management  of  boilers. 

"  Ist  To  avoid  explosions  from  internal  pressure,  cylindrical  boilers  of  maximum 
forms  and  strength  must  be  used,  including  all  the  necessary  appendages  of  safety-valves, 
<&c. 

"  2d.  Explosions  arising  from  deficiency  of  water  may  be  prevented  by  the  fusible 
alloys,  bursting  plates,  good  feed  pumps,  water  gauges,  alarms  and  other  marks  of  in- 
dication ;  but  above  all,  the  experienced  eye  and  careful  attention  of  the  engineer  is  the 
greatest  security. 

"  3d.  Explosions  from  collapse  are  generally  produced  from  imperfect  construction, 
which  can  only  be  remedied  by  adopting  the  cylindrical  form  of  boiler,  and  a  valve  to 
prevent  the  formation  of  vacuum  in  the  boiler. 

"4th.  Explosions  from  defective  construction  admit  of  only  one  simple  remedy,  and 
that  is,  the  adoption  of  those  forms  which  embody  the  maximum  powers  of  resistance  to 
internal  pres^sure,  and  such  as  we  have  already  recommended  for  general  use. 

"  Lastly.  Good  and  efficient  management,  a  respectable  and  considerate  engineer,  and 
the  introduction  of  such  improvements,  precautions,  and  securities  as  we  have  been  able 
to  recommend,  will  not  only  ensure  confidence,  but  create  a  better  system  of  manage- 
ment in  all  the  requirements  necessary  to  be  observed  for  the  prevention  of  steam  boiler 
explosions.     {Fairhairn,  in  Lecture  at  Leeds.) 


BOMBAZINE.    A  worsted  stuff,  sometimes  mixed  with  silk. 

BONES.  (0,»,  Fr. ;  Knochen^  Germ.)  They  form  the  frame  work  of  animal  bo<lies, 
commonly  called  the  skeleton ;  upon  which  the  soft  parts  are  suspended,  or  in  which  they 
are  enclosed.  Bones  are  invested  with  a  membrane  styled  the  periosteum,  which  is 
composed  of  a  dense  tissue  aflbrding  glue;  whence  it  is  convertible  into  jelly,  by 
ebullition  with  water.  Bones  are  not  equally  compact  throughout  their  whole  sub- 
stance; the  long  ones  have  tubes  in  their  centres  lined  with  a  kind  of  periosteum,  of 
more  importance  to  the  life  of  the  bones  than  even  their  external  coat.  The  flat,  as 
well  as  the  short  and  thick  bones,  exhibit  upon  their  surface  an  osseous  mass  of  a 
dense  nature,  while  their  interior  presents  a  cavity  divided  into  small  cellules  by  their 
bony  partitions. 

In  reference  to  the  composition  of  bones,  we  have  to  consider  two  principal  constitu- 
ents; the  living  portion  or  the  osseous  cartilage,  and  the  inorganic  or  the  earthy  salts  of 
the  bones. 

The  osseous  cartilage  is  obtained  by  suspending  bones  in  a  large  vessel  full  of  dilute 
muriatic  acid,  and  leaving  it  m  a  cool  place  at  about  50°  Fahr.  for  example.  The  acid 
dissolves  the  earthy  salts  of  the  bones  without  perceptibly  attacking  the  cartilage,  which, 
at  the  end  of  a  short  time,  becomes  soft  and  Iranslucid,  retaining  the  shape  of  the  bones; 
whenever  the  acid  is  saturated,  before  it  has  dissolved  all  the  earthy  salts  it  should  be 
renewed.  The  cartdage  is  to  be  next  suspended  in  cold  water,  which  is  to  be  frequently 
changed  idl  it  has  removed  all  the  acidity.  By  drying,  the  cartilage  shrinks  a  little, 
and  assumes  a  darker  hue,  but  without  losing  ts  translucency.  It  becomes,  at  the 
same  time,  hard  and  susceptible  of  breaking  when  bent,  but  it  possesses  great 
strength.  ° 

This  cartilage  is  composed  entirely  of  a  tissue  passing  into  gelatine.  By  boilin^'  with 
water,  it  is  very  readily  convertible  into  a  glue,  which  passes  clear  and  colorless  though 
Uie  filter,  leaving  only  a  small  portion  of  fibrous  matter  insoluble  by  further  boilin<'. 
This  matter  is  produced  by  the  vessels  which  penetrate  the  cartilage,  and  carry  nourish- 
ment to  the  bone.  We  may  observe  all  these  phenomena  in  a  very  instructive  manner, 
by  macerating  a  bone  in  dilute  muriatic  acid,  till  it  has  lost  about  the  half  of  its  salts: 
then  washing  it  with  cold  water,  next  pouring  boiling  water  upon  it,  leaving  the 
whole  m  repose  for  24  hours,  at  a  temperature  a  few  degrees  below  212°  Fahr. 

The  cartilage,  which  has  been  stripped  of  its  earthy  salts,  dissolves,  but  the  smaU 
vessels  which  issue  from  the  undecornposed  portion  of  the  bone  remain  under  the  form 
01  white  plumes,  if  the  water  has  received  no  movement  capable  of  crushing  or  breaking 
them.  We  may  then  easily  recognise  them  with  a  lens,  but  the  slightest  touch  tears 
them,  and  makes  them  fall  to  the  bottom  of  the  vessel  in  the  form  of  a  precipitate;  if 
we  digest  bones  with  strong  hot  muriatic  acid  so  as  to  accelerate  their  decomposition,  a 
portion  of  the  cartilage  dissolves  in  the  acid  with  a  manifest  disengagement  of  carbonic 
acid  gas,  which  breaks  the  interior  mass,  and  causes  the  half-softened  bone  to  begin  to 
spilt  into  fibrous  plates,  separable  in  the  direction  of  their  length.  According  to  Marx, 
these  plates,  when  sufficiently  thin,  possess,  like  scales  of  mica,  the  property  of  polar! 
izmg  light,  a  phenomenon  which  becomes  more  beautiful  stUl  when  we  soak  them  with 
the  essential  oil  of  the  bark  of  the  Laurus  Cassia.  The  osseous  cartilage  is  formed 
before  the  earthy  part.  The  long  bones  are  then  solid,  and  they  become  hollow  only  in 
proportion  as  the  earthy  salts  appear.  In  the  new-born  infant,  a  large  portion  of  the 
bones  IS  but  partially  fiUed  with  these  salts,  their  deposition  in  cartila^V  takes  place 
under  certain  invariable  point,  of  ossijication,  and  begins  at  a  certain  period  after  con- 
SaUon  ha^iLr^'  ^^'  ^^^  ""^  ^^^  ^°'^'''  according  to  the  progress  which 

of ^limp^"'^^  ^^"'  ""^  ^"""f"  ^'^  composed  principally  of  the  phosphate  and  carbonate 
or  lirne  in  various  proportions,  variable  in  diff-erent  animals,  and  mixed  with  small 
q^mntities,  equal  y  variable,  of  phosphate  of  magnesia  and  fluate  of  lime  The  eS 
means  of  procunng  the  earthy  salts  of  bones  consists  in  burnin<r  them  to  whiteness  but 
beLXa'd  in'tt^hon^'^'f  in  this  manner  contains  substances  which  5:^0^^: 
exarol  sn  nh!f^^  and  which  did  not  form  a  part  of  their  earthy  salts ;  as,  for 

SineVlrLn  t  '"^y^""^  ^^  ^^^  ^^^^^^^  of  the  sulphur  of  fnc  boucs  and  the 
o  he  hand^rlt^rr'"^:?"  /T  ,^^'  ^^^'"^^^  ^^^^  ^^i^^h  ii  was  combined.  On  the 
Sis  the  ^rodu-t  nr'!L^rt-^^  '^-f-'^l  ^^'  ^"^'  '''  ^^'•^^"ic  ^C'd.  As  the  sulphuric 
c^n  affonl  So  t^lsn'r  ?  "fJ'""'  '  ''  ^^'^'^^^  '^""^  *"  acidulous  solution  of  a  fresh  bone 
She  Wsaks  ^^7^1^  ^''\  T''^'^  ^-^  ^^•^''"^-  "T^^  phosphate  of  lime  contained  in 
e^uivX'tTo?  thP  «c!S  ^  /^!'\'^  consisting,  according  to  Berzelius,  of  three  prime 
oTthe  lauer  hitl^'^r^  ^'S^'-  ""^.^^^  ^^'^ '  °^  ^^  2,677  parts  of  the  form.-,  and  2,8 18 
excess  iVam^^^^^^  Whin  «^^^»»f  ,^^^"  ^^  precipitate  the  phosphate  of  lime  b;  an 
of  sulnh urT^^r,  ;  ,l)^^e"/alcined  bones  are  distilled  in  a  retort  with  their  own  weight 
ri4  TK  ru  '^  little  fluonc  acid  is  disengaged,  and  it  acts  on  the  surface  of  the 
leUu;  Thev  w.r5  -J^f^^r  'i  '^'  ^"^^  «^  '"^"  ^«d  horned  catUe,  are  given  by  Ber! 
no  more  wegit  "^"^  ^"'"^  ''"^^^^  *^^  ^^^  ^^'  ^^^  perio  teum^till  they  lost 


I- 


i|i 


ri!t 


llf 


224 


BONES. 


Human  bone. 

Ox  boB*. 

Cartilage  completely  soluble  in  water         -        -        .        . 
"Vessels-        --------- 

Subphosphale  with  a  little  fluale  of  lime    -        -        -        - 

Carbonate  of  lime  -------- 

Phosphate  of  mas;nesia      ------- 

Soda  with  very  little  muriate  of  soda      -        -        -        - 

32-17  > 
M3  5 

63-04 

11-3 
1-16 
1-20 

333 

57-35 
3-85 
2-05 
3-45 

100-00 

100-00 

The  most  essential  difference  in  the  composition  of  these  bones  is  that  those  of  man 
contain  three  times  as  much  carbonate  of  lime  as  those  of  the  ox ;  and  that  the  latter 
are  richer  in  phosphate  of  lime  and  magnesia  in  the  same  proportion.  Fernandez  de 
Barros  has  established  a  comparison  between  the  phosphate  and  carbonate  of  lime  in 
the  bones  of  different  animals.  He  found  in  100  parts  of  earthy  sa.H  of  the  bones  of  the 
following  animals : — 


Lion 

Sheep 

Hen 

Frog 

Fish 


Phosphate  oflime 


95-0 
80-0 
83-9 
95-2 
91-9 


Carb.  lima. 


2-5 

19-3 

10-4 

2-4 

5-3 


The  bones  of  fish  are  divided  into  those  which  contain  earthy  salts  and  those  which 
have  none,  called  cartilaginous  fishes.  The  enamel  of  the  teeth  is  composed  as 
follows : — 


Phosphate  of  lime  with  fluate  of  lime        -        -        - 
Carbonate  of  iime         ----«. 

Phosphate  of  magnesia     ------ 

Soda     .--.....- 

Brown  membranes  attached  to  the  tooth,  alkali,  water 


Human  eaaniel. 


88-5 
8-0 
1-5 
0-0 
2-0 

100-0 


Ox  enamol. 


850 
7-1 
3-0 
1-4 
3-5 


1000 


In  the  arts,  the  bones  are  employed  by  turners,  cutlers,  manufacturers  of  animal  char- 
coal, and,  when  calcined,  by  assayers  for  making  cupels.  In  agriculture,  they  arc 
employed  as  a  manure,  for  which  purpose  they  should  be  ground  in  a  mill,  and  the  pow- 
der sowed  along  with  the  seeds  in  a  drill.  It  is  supposed,  in  many  cases,  to  increase  the 
crop  in  weight  of  grain  and  straw  together,  by  from  40  to  50  per  cent.  In  France,  soup 
is  extensively  made  by  dissolving  bones  in  a  steam-heat  of  two  or  three  days'  continu- 
ance. The  shavings  of  hartshorn,  which  is  a  species  of  bone,  afford  an  elegant  jelly : 
the  shavings  of  calves'  bones  may  be  used  in  their  stead. 

Living  bones  acquire  a  red  tinge  when  the  animals  receive  madder  with  their  food ; 
but  they  lose  it  when  the  madder  is  discontinued  for  some  time. 

Tlie  following  analysis  of  the  middle  part  of  the  thigh-bone  of  a  man  of  80  years  of 
age  by  Marchand,  merits  confidence : — 


1.  Cartilage  insoluble  in  muriatic  acid 

2.  Do.        soluble  in  do. . 

3.  Blood-vessels  and  nerves  . 

4.  Subphosphate  of  lime     .         .         .         . 

5.  Fluoride  of  calcium  .... 

6.  CHrbonate  of  lime  .         .        ,.         , 

7.  Phosphate  of  magnesia 

8.  Soda      ....... 

9.  Chlorsodium      .  ... 
10.  Oxides  of  iron  and  manganese,  and  loss 


27-23 
6-02 
1-01 

52-26 
1-00 

10-21 

1-06 

,    0-92 

0.25 

1.06 

100-00 


The  human  bonea  contain  much  more  carbonate  of  lime  than  those  of  oxen  ;  which 
are,  however,  richer  in  phosphate  of  lime  and  magnesia.  The  proportion  of  cartila- 
ginous matter  in  bones  is  not  uniform,  but  varies  in  the  same  species  of  animal  with 
age,  sex,  and  pasture.  The  quantity  of  bones  imported  in  1850  amounted  to  27,198 
tons,  and  in  1851  to  81,956  ttms. 


BONE  BLACK. 


225 


BONE  BLACK  (Noir  (Tos,  Fr. ;  KnochanschwarUy  Germ.),  or  Jnimal  ckarcoaly  as 
it  is  less  correctly  called,  is  the  black  carbonaceous  substance  into  which  bones  are 
converted  by  calcination  in  close  vessels.  This  kind  of  charcaol  has  two  principal 
applications :  to  deprive  various  solutions,  particularly  sirups,  of  their  coloring  matters, 
and  to  furnish  a  black  pigment.  The  latter  subject  will  be  treated  of  under  Ivory 
Bi:.ACK. 

The  discovery  of  the  antiputrescent  and  decoloring  properties  of  charcoal  in  general, 
is  due  to  Lowitz,  of  Petersburg ;  but  their  modifications  have  occupied  the  attention  of 
many  chemists  smce  his  time.  Kels  published,  in  1798,  some  essays  on  the  discolonng 
of  mdigo,  saffron,  madder,  sirup,  &c.  by  means  of  charcoal,  but  he  committed  a  mistake 
m  supposing  bone  black  to  have  less  power  than  the  charcoal  of  wood.  The  first 
useful  application  of  charcoal  to  the  purification  of  raw  colonial  sugar  was  made  by 
M.  Guillon,  who  brought  into  the  French  markets  considerable  quantities  of  fine  sirups, 
which  he  discolored  by  ground  wood  charcoal,  and  sold  them  to  great  advantage,  as 
much  superior  to  the  cassonades  of  that  time.  In  1811,  M.  Figuier,  an  apothecary  at 
Montpeliier,  published  a  note  about  animal  charcoal,  showing  that  it  blanched  vinegars 
and  wines  with  much  more  energy  than  vegetable  charcoal;  and,  lastly,  in  1812, 
M.  Derosnes  proposed  to  employ  animal  charcoal  in  the  purification  of  sirups  and 
sugar  refinmg.  The  quantities  of  bone  black  left  in  the  retorts  employed  bv  MM 
Payen,  for  producing  crude  carbonate  of  ammonia,  furnished  abundant  materials  for 
making  the  most  satisfactory  experiments,  and  enabled  these  gentlemen  soon  to  ob- 
tain ten  per  cent,  more  of  refined  sugar  from  the  raw  article  than  had  been  formerlv 
extracted,  and  to  improve,  at  the  same  time,  the  characters  of  the  lumns  bastanls 
treacle,  &c.  *  »    «*oi.«iiuj». 

The  calcination  of  bones  is  effected  by  two  different  systems  of  apparatus-  by  heatin-- 
them  m  a  retort  similar  to  that  in  which  coal  is  decomposed  in  the  gas  works  or  in 
small  pots  piled   up  in  a  kiln.     For  the  description  of  the  former,   see  Gas-Light 
On  the  second  plan,  the  bones,  broken  into  pieces,  are   put   into  small    cast-iron  not^ 
of  the  form  shown  in  Jig.  154,  about  three  eighths  of  an  inch  thick,  two  of  which^e 
dexterously  placed  with  their  mouths  in  contact,  and  then  luted  tot^ether  with  loam 
The  hp  of  the  upper  pot  is  made  to  slip  inside  of  the  under  one.    These  double  vessels* 
containing  together  about  fifty  pounds  of  bones,  are  arranged  alongside,  and  over  each 
other,  m  an  oven,  like  a  potter's  kiln,  till  it  be  filled.     The  oven  or  kiln  mav  be  either 
oblong  or  upright.     The  latter  is  represented  in  figs.  156,  156,  157.     a  is  the  fireplace 
or  grate  for  the  fuel;  c  c  are  the  openings  in  the  dome  of  the  furnace  throu-h  which 
the  flame  flows ;  the  divisions  of  these  orifices  are  shown  in  Jig.  157      b  is  the  wall  of 
bnck-work.    d  the  space  in  which  the  pots  are  distributed,     e  is  the  door  by  which  the 
workman  carries  m  the  pots,  which  is  afterwards  built  up  with  fire-bricks,  and  plastered 
over  with  loam.    This  door  is  seen  in  Jig.  155.    r  f  are  the  lateral  flues  for  conveyine 
the  disengaged  gases  into  the  air.  ^  ^ 


164 


165 


J 


caldnini  bones   T    rt  ^''T^V^^^-^^*  ^^^'  *  ^^"^"^  ^^^^  «^  ^  ^-i^^^^^i  ^^1"  ^or 
is  seClt^l  bv  a  ni  «r  ^  fe-chamber  lying  upon  a  level  with  the  sole  of  the  kiln;  it 

rolsTh^Jd  arP    P^  '  ^'a^  ^^^  f^.''"^"»  ^'""^^^  ''    ^"^  '^^  Pi"^^  or  wall,  several 
latmg  thel^dS^n^rtt^^^^^^^^  ^"^'^^^  ^-P-P^-«  ^-  -^- 


■?p 


226 


BONE  BLACK. 


BONE  BLACK. 


227 


i  m- 


|i 


iii 


i 
t 


at  once ;  the  greatest  heat  being  nearest  the  roof  of  the  kiln  ;  which  resembles,  in  manf 
respects,  that  used  for  baking  pottery  ware. 

In  both  kilns  the  interior  walls  are  built  of  fire-bricks.  In  the  oblong  one,  the 
fiercest  heat  is  near  the  vaulted  roof;  in  the  upright  one,  near  the  sole ;  and  the  potp, 
containing  the  larger  lumps  of  bones,  should  be  placed  accordingly  near  the  top  of  the 
former,  and  the  bottom  of  the  latter.  Such  a  kiln  may  receive  about  seventy  double 
pots,  containing  in  the  whole  thirty-five  cwt.  of  bones. 

After  the  earth  is  filled  with  the  pots,  and  the  entrance  door  is  shut,  the  fire  is 
applied  at  first  moderately,  but  afterwards  it  must  be  raised  and  maintained,  at  a  brisk 
heat,  for  eight  or  ten  hours.  The  door  of  the  ash-pit  and  the  damper  may  now  be 
nearly  closed,  to  moderate  the  draught,  and  to  keep  up  a  steady  ignition  for  six  or  eight 
hours  longer,  without  additional  firing;  after  which  the  doors  must  be  all  opened  to 
cool  the  furnace.  When  this  is  done,  the  brick-work  of  the  entrance  door  must  be 
taken  down,  the  kiln  must  be  emptied,  and  immediately  filled  again  with  a  set  of  pot:j 
peviously  filled  with  bones,  and  luted  together ;  the  pots  which  have  been  ignited  may, 
in  the  course  of  a  short  time,  be  opened,  and  the  contents  put  into  the  magazine.  But 
in  operating  with  the  large  decomposing  cylinder  retort,  the  bones  being  raked  out  hot, 
must  be  instantly  tossed  into  a  receiver,  which  can  be  covered  in  air-tight  till  they  are  cool. 

The  bones  lose  upon  the  average  about  one  half  of  their  weight  in  the  calcination. 
In  reference  to  the  quality  of  the  black,  experience  has  shown  that  it  is  so  much  more 
powerful  as  a  discoloring  agent,  as  the  bones  from  which  it  was  made  have  been  freer 
from  adhering  fatty,  fleshy,  and  tendinous  matters. 

The  charcoal  is  ground  in  a  mill,  either  to  a  fine  powder  and  sifted,  or  into  a  coarse 
granular  state,  like  gunpowder,  for  the  preparation  of  which  two  sieves  are  required,  one 
with  moderately  fine  meshes,  to  allow  the  small  dust  to  pass  through,  and  one  with  large 
meshes,  to  separate  the  proper-sized  grains  from  the  coarser  lumps.  Either  a  corn-mill, 
an  edgestone  mill,  or  a  steel  cylinder  mill,  may  be  employed  for  grinding  bone-black,  and 
it  is  generally  damped  in  the  operation  to  keep  down  the  fine  dust. 

Bone-black,  as  found  in  commerce,  is  very  variable  in  its  discoloring  power,  which 
arises  from  its  having  been  exposed  either  to  too  great  a  heat  which  has  glazed  its  car- 
bon, or  too  low  a  heat  which  has  left  its  albumen  imperfectly  decomposed.  A  steady 
ignition  of  due  continuance  is  the  proper  decomposing  temperature.  Its  composition  is 
generally  as  follows  : — 

Phosphate  of  lime,  with  carbonate  of  lime,  and  a  little  sulphuret  of  iron,  or  oxyde  of 
iron,  88  parts;  iron  in  the  state  of  a  silicated  carburet,  2  parts;  charcoal  containing 
about  one  fifteenth  of  azote,  10  parts.  None  of  the  substances  present,  except  the  char- 
coal, possesses  separately  any  discoloring  power. 

The  quality  may  be  tested  by  a  solution  of  brown  sugar,  or  molasses,  or  of  indigo  in 
ftulphuric  acid.  The  last  is  generally  preferred  by  the  French  chemists,  who  have  occu- 
pied themselves  most  with  this  subject,  and  it  contains  usually  one  thousandth  part 
of  its  weight  of  this  dye-drug  of  the  best  quality.  Other  animal  substances  yield  a 
charcoal,  possessed  of  very  considerable  discoloring  properties.  The  following  table  by 
M.  Bussy  exhibits  an  interesting  comparison  of  almost  every  kind  of  charcoal  in  this 
point  of  view. 


Table  of  the  discoloring  powers  ( 

3f  diflerent  charcoals. 

F 

Indigo  test 

Molasses  lesf 

Blanching  by 

Power  by 

Species  of  Charcoal. 

Weight. 

consumed. 

consumed. 

indigo. 

molastet. 

Gramme. 

Litres. 

Blood  calcined  with  potash 

1-60 

0-18 

50 

20 

Ditto  with  chalk   -    -    - 

0-57 

0-10 

18 

11 

Ditto  with  phosphate  lime 

0-38 

0-09 

12 

10 

Gelatine  ditto  with  potash 

M5 

0-14 

36 

15-5 

Albumen  ditto  ditto    -    - 

1-08 

0-14 

34 

1,5-5 

Starch  ditto  ditto  -    -    - 

0-34 

0-08 

10-6 

8-8 

Charcoal  from  acet.  potash 

0-18 

0-04 

5-6 

4-4 

Ditto  from  carb.  sciia  by 

phosphorus     -     -     -     - 

0-38 

0-08 

12 

8-8 

Calcined  lamp  black  -    - 

0-128 

0-03 

4 

3-3 

Ditto  ditto  potash  -    -     - 

0-55 

0-09 

15-2 

10-6 

Bone  black  treated  with 

mur.  acid  and  potash  - 

1-45 

0-18 

45 

20 

Bone  black  ditto  with  mur. 

acid    ------ 

0-06 

0-015 

1-87 

1-6 

Oil  calcined  with  phosph. 

of  lime     -    -    -    -    - 

0-064 

0-017 

2 

1-9 

Crude  bone  black  -    -    - 

0-032 

0-009 

1 

1 

With  regard  to  the  mode  of  operation  of  bone  black  on  colored  liquids,  M.  Paycn 
showed  in  his  prize  essay,  1.  That  the  decoloring  power  of  charcoal  depends  in 
general  upon  its  state  of  division ;  2.  That  in  the  various  charcoals,  the  ca/bonaceous 
matter  acts  only  upon  the  coloring  matters,  combining  with  and  precipitating  them ;  3. 
That  in  the  application  of  charcoal  to  the  refining  of  sugar,  it  acts  also  upon  the  gluten, 
for  it  singularly  promotes  crj'stallization ;  4.  That  according  to  the  above  principles,  the 
decoloring  action  of  charcoals  may  be  so  modified,  as  to  make  the  most  inert  become 
the  most  active ;  5.  That  the  distinction  between  animal  and  vegetable  charcoals  is  im- 
proper, and  that  we  may  substitute  for  it  that  of  dull  and  brilliant  charcoals ;  6.  That 
of  the  substances  present  in  charcoal  besides  carbon,  and  particularly  animal  charcoal, 
those  which  favor  the  decoloring  action,  have  an  influence  relative  only  to  the  carbon ; 
they  serve  as  auxiliaries  to  it,  by  insulating  its  particles,  and  presenimg  them  more 
freely  to  the  action  of  the  coloring  matter;  7.  That  animal  charcoal,  besfles  its  de- 
coloring power,  has  the  valuable  property  of  taking  lime  in  solution  from  water  and 
Birup ;  8.  That  neither  vegetable,  nor  other  charcoals,  "besides  the  animal,  have  this 
power  of  abstracting  lime ;  9.  That  by  the  aid  of  the  decolorimeter,  or  graduated  tube 
charged  with  test  solution  of  indigo  or  molasses,  it  is  easy  to  appreciate  exactly  the  dc 
coloring  properties  of  all  kinds  of  charcoal. 

DiflTerent  varieties  of  lignite  (fossilized  wood)  or  even  pit  coal,  when  well  carbonizec 
in  close  vessels,  aflTord  a  decoloring  charcoal  of  considerable  value.  By  reducina;  IOC 
parts  of  clay  into  a  thin  paste  with  water,  kneading  into  it  20  parts  of  tar,  and  500  of 
finely-ground  pit  coal,  drying  the  mixed  mass,  and  calcining  it  out  of  contact  of  air,  s 
charcoally  matter  may  be  obtained  not  much  inferior  to  bone-black  in  whitening  sirups. 

The  restoration  of  animal  charcoal  from  burnt  bones,  for  the  purpose  of  sugar  re- 
fining, has  been  long  practised  in  France.  Mr.  W.  Parker  has  lately  made  the  following 
process  the  subject  of  a  patent.  The  charcoal,  when  taken  from  the  vessel  in  which  it 
has  been  employed  for  the  purposes  of  clarifying  the  sugar,  is  to  be  thoroughly  washed 
with  the  purest  water  that  can  be  obtained,  in  order  to  remove  all  the  saccharine  matter 
adhering  to  it.  When  the  washing  process  has  been  completed,  the  charcoal  is  laid  out 
to  dry,  either  in  the  open  air  or  in  &  suitable  stove,  and  when  perfectly  free  from  moist- 
ure, it  is  to  be  separated  into  small  pieces  and  sifted  through  a  sieve,  the  wires  or  meshes 
of  which  are  placed  at  distances  of  about  two  and  a  half  in  every  inch.  This  sifting 
will  not  only  divide  the  charcoal  into  small  pieces,  but  will  cause  any  bits  of  wood  or 
other  improper  matters  to  be  separated  from  it. 

The  charcoal,  thus  prepared,  is  then  to  be  packed  lightly  in  cylindrical  vessels  called 
crucibles,  with  some  small  quantity  of  bones,  oil,  or  other  animal  matter  mixed  with  it. 
The  crucibles  are  then  to  be  closed  by  covers,  and  luted  at  the  joints,  leaving  no  other 
opening  but  one  small  hole  in  the  centre  of  the  cover,  through  which  any  gas,  generated 
within  the  vessel  when  placed  in  the  oven  or  furnace,  may  be  allowed  to  escape. 

The  crucibles  are  now  to  be  ranged  round  the  oven,  and  placed,  one  upon  another,  in 
vertical  positions ;  and  when  the  oven  is  properly  heated,  gas  will  be  generated  within 
each  crucible,  and  issue  out  from  the  central  hole.  The  gas  thus  emitted,  being  of  an 
inflammable  quality,  will  take  fire,  and  assist  in  heating  the  crucibles ;  and  the  operation 

being  carried  on  until  the  cruci- 
bles become  of  a  red  heat,  the 
oven  is  then  to  be  closed,  and  al- 
lowed to  cool;  after  which  the 
crucibles  are  to  be  removed, 
when  the  charcoal  will  be  found 
to  have  become  perfectly  reno- 
vated, and  fit  for  use  as  before. 

Bone  Black,  or  animal  charcoal 
restored.  A  process  for  this  pur- 
pose was  made  the  subject  of  a 
patent  by  Messrs.  Bancroft  and 
Maclnnes  of  Liverpool,  which 
consists  in  washing  the  granular 
charcoal,  or  digesting  it  when 
finely  ground,  with  a  weak  solu- 
tion of  potash  or  soda,  of  specific 
gravity  1-06.  The  bone  black 
which  has  been  used  in  sugar  re- 
fining may  thus  be  restored,  but 
it  should  be  first  cleared  from  all 
the  soluble  filth  by  means  of  water.. 
Mr.  F.  Parker's  method,  patent- 
ed in  June,  1839,  for  efiFecting  a 
like  purpose,  is  by  a  fresh  caloiiid^ 
tion  as  follows : — 


1  iiyyj'Z/yyyy/yyyyyyyyyyyyyjWA'//y^. , 


•iS 


I* 


I 


I'-  ■ 


228 


BOOKBINDING. 


Fig.  160  represents  a  front  section  of  the  furnace  and  retort :  and  fia  161  is  a  tran. 
Terse  vertical  section  of  the  same,     a  is  a  retort,  surrounded  by'the  fl^S'  of  the  furnace 
b  ;c  ,8  a  hopper  or  chamber,  to  which  a  constant  fresh  supply  of  the  black  is  furnished 
^  *vlf  T'^v^.P''*^"^  has  been  withdrawn,  from  the  lower  part  of  a     j  is  the  tot- 
ing vessel,  which  IS  connected  to  the  lower  part  of  the  retort  a  by  a  sand  joinVr  The 
cooler  ^18  made  of  thm  sheet  iron,  and  is  large ;  its  bottom  is  closed  withH^de  pla  e 
^n.l^K    ff  ffter  passing  slowly  through  the  retort  a  into  the  vessel  ±  gets  so  much 
Xw  T.J..  f'  VT  '*  '"^^''A  ^Y  ^  P"^^^^^  ^^^*  "^^y  be  safely  withdrfwn  so^to 

mS^BAmfc^7.^f^^^^^^  V'  '^f  '^""''^^^  meter, Vith  aslidedoor 

them'^wihXcrandsld:  Wrl"""^  '^^^'"^^  ^'^  ^^^^^^  '' '  ^-^'  ^^  --"^S 
~T^?sSlVpT/t%!S  '^^  P'"'"^^  "?^"'  ^^  V^'^^^ed  in  the  following  nianner  • 

th^r  J'      "^al^e  them  solid  and  smooth,  And  are  then  condensed  in  a  pres.     AneV 

quartos,  or  any  smaUer  size.    The  backs  a?e  no;%?„':j7a"d    L  e^ds tel^T.r^ 
opened  and  scraped  with  a  knife,  that  they  n,ay  be*D>ore  conveniemly  fi/el  to  Ss^e 
board  sides;  aAer  which  the  back  is  turned  with  a  hammer  the  bonk  hein»  fil/* 
press  between  boards,  called  backing  boards,  in  order  to  make  a  give  for  al"mL'^he 
p«teboard  s.des.    When  these  sides  are  applied,  holes  are  madeTthm  f™  Zi  ^e 
the  bands   through,   the  superfluous   end^i  are   n<i  nff  .„^   .t         1  ,.  "rawing 

It  IS  then  put  into  a  press  called  the  cutting  press  betwiitV,,!.  ll,.rX  "^        r  Yu 
ie,  even  with  the  press,  for  the  knife  to  ru/uponl'  and  l^  o  her^We'  TtheTnT 
to  cut  against.    After  this  the  pasteboards  are  c«rsoZr  whh  «  „„^  „r  •        I  '"''* 
and  last  of  all,  the  colors  are  sprSikled  on  the  edfe    rf  Se  W   wSh  aZ.h    "3' 
WsbnsUes;  the  brush  being  held  in  the  one  hand,  and Xd^^":^,S't^| 

A  patent  was  obtained  in  1799  by  Messrs.  John  and  Joseph  WiDiams  stationer,  in 
London,  for  an  unproved  method  of  binding  books  of  everv  descrfntin„    Vi.!  • 
ment  consist,  of  a  back,  in  any  curved  foii.lS'ed  .  S  afth?  Zes  ?nd  ZTrf 
iron,  steel,  copper,  brass,  tin,  or  of  ivory,  bone,  wood,  vellum  or  in  E  »n,  T,    •  i 
of  sufficient  firmness.    This  back  is  puTon  the  b<S  Teftre'iris  botd 'so  JsT„'/,"f' 
wb™  '"?"?  Pre^u-g the  edges;  and  the  advantage  of  it  is  that  it  prevems  he  Lt 
when  opened,  from  spreading  on  either  side,  and  causes  it  to  rise  in  any  part  to  near?^  a 
level  surface.    In  this  method  of  binding  the  sheets  are  prepared  in  the  usVa^  manner 
tten  sewed  on  vellum  slips,  glued,  cut,°clothed,  and  boariedror  ha?f  boari  ™.  Se  fi™ 

IbrlTMhem:  '^""  ^''^^'''  "  '"^"  '"'""''^'  J«^'«^  ""^  "P»  ""  boids,  orS 

A  patent  was  likewise  obtained  in  1800  by  Mr.  Ebenezer  Palmer  «  T/,„.i™  ....• 
for  an  improved  way  of  binding  books,  particularly  meSnts'  account  blk,     T^T"' 
KTe't'hTck'n^^s'jl'^^ir  '"°"°'^=-'"  ^Z'-^^^^^^^oP'^^ie  pTJ^dS; 

l^de-rte^gt^p^-^to^^ 

fx^^e^onhnrt::  ^h'esTtE  r- rtt'^ZetetTrthrhiS  7^-^?? 
?.The-^ts-^irj:^^:re^ir;t^frem^^^^^^ 

on  the  principle  of  aVk-chain  or  hiage.    Ther?iiSt\e  "^o'ttYoXo'^of  dX»J 
sizes,  as  may  be  required,  on  each  bar  of  the  hinge  or  chain  ;  bv  meanT  J  iW.  fc^f 

The  leather  used  in  covering  books  is  prepared  and  applied  as  foUows:  being  first 


BOOKBINDINa 


229 


162 


moistened  in  water,  it  is  cut  to  the  size  of  the  book,  and  the  thickness  of  the  edge  Js 
paired  off  on  a  marble  stone.  It  is  next  smeared  over  with  paste  made  of  wheat  flour, 
stretched  over  the  pasteboard  on  the  outside,  and  doubled  over  the  edges  within.  The 
book  is  then  corded,  that  is,  bound  firmly  betwixt  two  boards,  to  make  the  cover  stick 
strongly  to  the  pasteboard  and  the  back ;  on  the  exact  performance  of  which  the  neat- 
ness of  the  book  in  a  great  measure  depends.  The  back  is  then  warmed  at  the  fire  to 
soften  the  glue,  and  the  leather  is  rubbed  down  with  a  bodkin  or  folding  stick,  to  set  and 
fix  it  close  to  the  back  of  the  book.  It  is  now  set  to  dry,  and  when  dry,  the  boards  arc 
removed ;  the  book  is  then  washed  or  sprinkled  over  with  a  little  paste  and  water,  the 
edges  and  squares  blacked  with  ink,  and  then  sprinkled  fine  with  a  brush,  by  striking  it 
against  the  hand  or  a  stick ;  or  with  large  spots,  by  being  mixed  with  solution  of  green 
vitriol,  which  is  called  marbling.  Two  blank  leaves  are  then  pasted  down  to  the  cover, 
and  the  leaves,  when  dry,  are  burnished,  in  the  press,  and  the  cover  rolled  on  the  edges. 
The  cover  is  now  glazed  twice  with  the  white  of  an  egg,  filleted,  and,  last  of  all,  polished, 
by  passing  a  hot  iron  over  the  glazed  color. 

The  employment  in  bookbinding  of  a  rolling  press  for  smoothing  and  condensing  the 
leaves,  instead  of  the  hammering  which  books  have  usually  received,  is  an  improvement 
introduced  several  years  ago  into  the  trade  by  Mr.  W.  Burn.  His  press  consists  of  two 
iron  cylinders  about  a  foot  in  diameter,  adjustable  in  the  usual  way,  by  means  of  a  screw, 
and  put  in  motion  by  the  power  of  one  man  or  of  two,  if  need  be,  applied  to  one  or  two 
winch-handles.  In  front  of  the  press  sits  a  boy  who  gathers  the  sheets  into  packets,  by 
placing  two,  three,  or  four,  upon  a  piece  of  tin  plate  of  the  same  size,  and  covering  them 
with  another  piece  of  tin  plate,  and  thus  proceeding  by  alternating  tin  plates  and  bundles 
of  sheets  till  a  sufficient  quantity  have  been  put  together,  which  will  depend  on  the  stiflT- 
ness  and  thickness  of  the  paper.  The  packet  is  then  passed  between  the  rollers  and  re- 
ceived by  the  man  who  turns  the  winch,  and  who  has  time  to  lay  the  sheets  on  one  side, 
and  to  hand  over  the  tin  plates  by  the  time  that  the  boy  has  prepared  a  second  packet. 
A  minion  Bible  may  be  passed  through  the  press  in  one  minute,  whereas  the  time 
necessary  to  beat  it  would  be  twenty  minutes.  It  is  not,  however,  merely  a  saving  of 
time  that  is  gained  by  the  use  of  the  rolling-press ;  the  paper  is  made  smoother  than  it 

would  have  been  by  beating,  and  the  compression  is 
so  much  greater,  that  a  rolled  book  will  be  reduced 
to  about  five  sixths  of  the  thickness  of  the  same  book 
if  beaten.  A  shelf,  therefore,  that  will  hold  fifty 
books  bound  in  the  usual  way  would  hold  nearly 
sixty  of  those  bound  in  this  manner,  a  circumstance 
of  no  small  importance,  when  it  is  considered  how 
large  a  space  even  a  moderate  library  occupies,  and 
that  book-cases  are  an  expensive  article  of  furniture. 
The  rolling-press  is  now  substituted  for  the  hammer 
by  several  considerable  bookbinders. 

Fig.  162  represents  the  sewing-press,  as  it  stands 
upon  the  table,  before  which  the  bookbinder  sits. 
Fig.  163  is  a  ground  plan,  without  the  parts  a  and 
n  in  the  former  figure,  a  is  the  base-board,  sup- 
ported upon  the  cross  bars  m  n,  marked  with  dotted 
lines  in^g.  163.  Upon  the  screw  rods  r  r,fig.  162,  the  nuts  t  d  serve  to  fix  the  flat  upper 
bar  n,  at  any  desired  distance  from  the  base.  That  bar  has  a  slit  along  its  middle,  through 
«rhich  the  hooks  below  z  z  pass  down  for  receiving  the  ends  of  the  sewing  cords  p  p, 

fixed  at  y  y,  and  stretched  by  the  thumb-screws  z  z. 
The  bar  y  y  is  let  into  an  oblong  space  cut  out  of  the 
front  edge  of  the  base-board,  and  fixed  there  by  a 
moveable  pin  a,  and  a  fixed  pin  at  its  other  end,  round 
which  it  turns. 

Fig.  164  is  the  bookbinder's  cutting-press,  which  is 
set  upright  upon  a  sort  of  chest  for  the  reception  of 
the  paper  parings ;  and  consists  of  three  sides,  being 
open  above  and  to  the  left  hand  of  the  workman. 
The  pressbar,  or  beam  a,  has  two  holes  n  n  upon  its 
under  surface,  for  securing  it  to  two  pegs  standing  on 
the  top  of  the  chest.  The  screw  rods  t  /pass  through 
two  tapped  holes  in  the  bar,  marked  with  6  c  at  its 
upper  end ;  their  heads  r  r  being  held  by  the  shoulders  o  o.  The  heads  are  pierced  with 
holes  into  which  lever  pins  are  thrust  for  screwing  the  rods  hard  up.  The  heavy  beam 
a  remains  immoveable,  while  the  parallel  bar  with  the  book  is  brought  home  towards  it 
by  the  two  screws.    The  two  rulers  s  s  serve  as  guides  to  preserve  the  motions  truly 


230 


BOOKBINDING. 


BOOKBINDING. 


231 


i  ii: 


M 


^^h  Iw  ^i^r^^  ^u*'*"^^  ^""^^  ^'^  *  '  8:«ide  between  them  the  end  bar  c,  of  the 

M     nT?  '^^  ^  ^^"""^^  ** ''  ^*^^  *^s  clamping  screw «.  ^ 

i«^J[*  .r^^r"*  P^'^.^^^S^  engineer  of  the  Bank  of  England,  distinguished  for  mechanical 
&?    eYth'eV  trr^^^       "  "^7^"^^  -chine  for  cutting  the  edg?s  of  bo^JS,  baTnot'es 
f^  ini    1      1^^  **/''!  *'''  polygonal,  with  mathematical  precision.     Fig.  165,  represent^ 
an  end  elevation  of  the  machine.     Fig.  166,  a  side  view  of  the  sanfe,  Uie  lefters  of 
reference  indicating  the  same  parts  of  the  machine  in  each  of  the  figures 

«,  is  the  top  cross  bar  with  rectangular  grooves  b  b ;  c  c,  are  side  posts;  d  d, cross  feet 
to  the  same,  with  strengthening  brackets;  e  e,  a  square  box,  in  wh  ch  the  prei  stands 
for  holding  waste  cuttings.  Fig.  167,  is  a  cross  section  of  the  uprghtp^srfc  taken 
n?.hP "..^^^>  ^^"'  r  r*^"8^J*'-  g'-^oves  in  the  upright  posts,  for^the'^rojectin.^  enS 
of  this  n?pUT  r''  ^^^^«'/>^^.«"d«  "P  and  down  in.^  In  the  middle  of^hiundeVside 
Lrew?  whio{'  tl't  "'  \^'^'  ^'^'''  ^^^^^^  »^  *  ••^'^'^^  ^^^^^s>  to  receive  the  top  of  thi 
b^h^  fi^lv  tn  r  ?  '^^  ^%'i  ''•*"  "°''  P'^^^  '^>  ^ilarly  iade  with  the  former,  but 
bolted  firmly  to  the  posts  c  c.    Upon  the  screw  g,  there  is  a  circular  handle  or  ring  i,  for 

166 


S^^ns  rfTLlr  ^''''Jt'"''  ir"^'"*')-  O'er  it  cross  holes  IW  ti,lue„i„,  the  pr«, 

1  n9 


M«' 


Across  the  middle  of  this  board,  and  narallpl  t^^TI     '■         Tl     ! 
made  fast,  which  fits  into  a  grc^ie  in  the^ottom  „r  .^  ^"Ti^  \  \  '^'  *^"?"^  P'^^«  '"  " 
of  this  is  seen  at  fig-  168,  andTmmediLtelv  und^r  fh^  •    '*  •  ^^^"^•'"tal  representation 
and/,  connected  tcfgeihe;,andnde^ew^  i'  1'°  '"^]^,f'*  ""'^  ^^^^  °^  ^ 

is  a  pin  for  a  circular  bo^d  n,^o  ^  u^n^^d^'S^^^^^^^^  ^^«  ^?^V> 

«  material  to  be  cut,"  with  a  saving  piece  between  Tt^n,!  ti    ^^."«^,^ard  is  placed  the 

be  divided  upon  its  edge  into  any  n^ber  of  paS  L^L^  J>^^^^^^    ^^"^  ""^'"^  "  ^ 
the  board  I,  to  point  to  each.  ^        required,  with  a  stationary  index  on 

It  will  now  be  understood  that  the  «  material  to  be  rut  »  «,«„  k    *        j 

thecen.™  pia  of  the  board  »,a„J  aUo  that  Jh'u'irAe  ririla'"rshS\"X 


ward  and  forward  under  the  top  cross  piece  a,  and  between  the  side  slide  slips  fe  fe,  the  ' 
surfaces  of  which  should  also  be  divided  into  inches  and  tenths. 

The  plough,  fig.  169,  shown  in  several  positions,  is  made  to  receive  two  knives  or 
cutters  as  the  "  material  to  be  cut"  may  require,  and  which  are  situated  in  the  plough 
as  I  now  describe.  The  plough  is  composed  of  three  principal  parts,  namely,  the  top, 
and  its  two  sides.  The  top  o,  is  made  the  breadth  of  the  cross  piece  a,  and  with  a 
handle  made  fast  thereon.  The  sides  'p  />,  are  bolted  thereto,  with  bolts  and  nuts  through 
corresponding  holes  in  the  top  and  sides.  The  figures  below  give  inside  views,  and 
cross  sections  of  the  details  of  the  manner  in  which  the  cutters  and  adjustments  are 
mounted.  A  groove  is  cut  down  each  cheek  or  side,  in  which  are  placed  screws  that 
are  held  at  top  and  bottom  from  moving  up  and  down,  but  by  turning  they  cause  the 
nuts  upon  them  to  do  so ;  they  are  shown  at  q  q.  These  nuts  have  each  a  pin  projecting 
inwards,  that  go  into  plain  holes  made  in  the  top  ends  of  cutters  r  r.  The  169th  and 
following  figs,  are  |  in  scale. 

The  cutters,  and  the  work  for  causing  them  to  go  up  and  down,  are  sunk  into  the 
cheeks,  so  as  to  be  quite  level  with  their  inner  surfaces.  Fig.  170  shows  one  of  those 
screws  apart,  how  fixed,  and  with  moveable  nut  and  projecting  pin.  The  top  of  each 
screw  terminates  with  a  round  split  down,  and  above  it  a  pinion  wheel  and  boss  thereon, 
also  similarly  split.  This  pinion  fits  upon  the  split  pin.  Above,  there  is  a  cross  section 
of  a  hollow  coupling  cap  with  steel  tongue  across,  that  fits  into  both  the  cuts  of  the  screw 
pin  and  pinion  boss,  so  that  when  lowered  upon  each  other,  they  must  all  turn  together. 
In  the  middle  and  on  the  top  of  the  upper  piece  o,  the  larger  wheel  a,  runs  loose  upon  its 
centre,  and  works  into  the  two  pinion-wheels  1 1.  The  wheel  s  has  a  fly-nut  with  wings 
mounted  upon  it. 

It  will  now  be  seen,  when  the  plough  is  in  its  place  as  at  fig.  171,  that  if  it  be  pushed 
to  and  fro  by  the  right  hand,  and  the  nut  occasionally  turned  by  the  left,  the  knives  or 
cutters  will  be  protruded  downwards  at  the  same  time,  and  these  either  will  or  will  not 
advance  as  the  coupling  caps  u  u  are  on  or  off.  The  ribs  v  v,  run  in  the  grooves  6  6, 
fig.  165,  and  keep  the  cutters  to  their  duty,  working  steadily.  The  top  cross  bar  a,  is  the 
exact  breadth  of  a  bank-note,  by  which  means  both  knives  are  made  to  cut  at  the  same 
time.    The  paper  is  cut  uniformly  to  one  length,  and  accurately  square. 

By  the  use  of  this  machine,  the  air-pump  paper-wetting  apparatus,  and  appendant 
press,  the  paper  of  45,000  notes  is  fully  prepared  in  one  hour  and  a  half  by  one  person, 
and  may  then  be  printed.  It  is  not  so  much  injured  by  this  process  as  by  the  ordinary 
method  of  clipping  by  hand,  soaking  it,  &c.,  which  more  or  less  opens  and  weakens  the 
fabric,  especially  of  bank-note  paper. 

One  of  ihe  greatest  improvements  ever  made  in  the  art  of  bookbinding  is,  apparently, 
that  for  which  Mr.  William  Hancock  has  very  recently  obtained  a  patent.  After 
folding  the  sheets  in  double  leaves,  he  places  them  vertically,  with  the  edges  forming  the 
back  of  the  book  downwards  in  a  concave  mould,  of  such  rounded  or  semi-cylindirical 
shape  as  the  back  of  the  book  is  intended  to  have.  The  mould  for  this  purpose  consists 
of  two  parallel  upright  boards,  set  apart  upon  a  cradle  frame,  each  having  a  portion  or 
portions  cut  out  vertically,  somewhat  deeper  than  the  breadth  of  the  book,  but  of  a  width 
nearly  equal  to  its  thickness  before  it  is  pressed.  One  of  these  upright  boards  may  be 
slidden  nearer  to  or  farther  from  its  fellow,  by  means  of  a  guide  bar,  attached  to  the  sole 
of  the  cradle.  Thus  the  distance  between  the  concave  bed  of  the  two  vertical  slots  in 
which  the  book  rests,  may  be  varied  according  to  the  length  of  the  leaves.  In  all  cases 
about  one  fourth  of  the  length  of  the  book  at  each  end  projects  beyond  the  board,  so 
that  one  half  rests  between  the  two  boards.  Two  or  three  packthreads  are  now  bound 
round  the  leaves  thus  arranged,  from  top  to  bottom  of  the  page  in  diflTerent  lines,  in 
order  to  preserve  the  form  given  to  the  back  of  the  mould  in  which  it  lay.  The  book  is 
next  subjected  to  the  action  of  the  press.  The  back,  which  is  left  projecting  very  slightly 
in  front,  is  then  smeared  carefully  by  the  fingers  with  a  solution  of  caoutchouc,  whereby 
each  paper-edge  receives  a  small  portion  of  the  cement.  In  a  few  hours  it  is  sufliciently 
dry  to  take  another  coat  of  a  somewhat  stronger  caoutchouc  solution.  In  48  hours,  4  ap- 
plications of  the  caoutchouc  may  be  made  and  dried.  The  back  and  the  adjoining  part 
of  the  sides  are  next  covered  with  the  usual  band  or  fillet  of  cloth,  glued  on  with  caout- 
chouc ;  after  which  the  book  is  ready  to  have  the  boards  attached,  and  to  be  covered  with 
leather  or  parchment  as  may  be  desired. 

We  thus  see  that  Mr.  Hancock  dispenses  entirely  with  the  operations  of  stitching, 
sewing,  sawing-in,  hammering  the  back,  or  the  use  of  paste  and  glue.  Instead  of  leaves 
attached  by  thread  stitches  at  2  or  3  points,  we  have  them  agglutinated  securely  along 
their  whole  length.  Books  bound  in  this  way  open  so  perfectly  flat  upon  a  table 
without  strain  or  resilience,  that  they  are  equally  comfortable  to  the  student,  the  musician. 


232 


BORA.CIC  ACID  LAGOONS. 


I 


ti 


Siij 


1841. 

cwta.  — 

cwta.  — 

cwts.  — 

£.  8,193 


1S49. 

7,888 

1 

7,246 

798 


IMS. 

14,986 

22 

18,717 

861 


1834. 
15,060 

620 
15,958 

422 


and  the  merchant.  The  caoutchouc  cement  moreover  being  repulsive  to  insects,  an  J 
not  affected  by  humidity,  gives  this  mode  of  binding  a  great  superiority  over  the  old 
iiietliod  with  paste  or  glue,  which  attracted  the  ravages  of  the  moth,  and  in  damp  situa- 
tions allowed  the  book  to  fall  to  pieces.  For  engravings,  atlasses,  and  ledgers,  this  bind- 
ing 18  admirably  adapted,  because  it  allows  the  pages  to  be  displayed  most  freely  with- 
out the  risk  of  dislocating  the  volume ;  but  for  security,  3  or  4  stitches  should  be  made. 
The  leaves  of  music  books  bound  with  caoutchouc,  when  turned  over  lie  flat  at  their 
whole  extent,  as  if  in  loose  sheets,  and  do  not  torment  the  musician  like  the  leaves  of 
the  ordinary  books,  which  are  so  ready  to  spring  back  again.  Manuscripts  and  collec- 
tions of  letters  which  happen  to  have  little  or  no  margin  left  at  the  back  for  stitching 
them  by,  may  be  bound  by  Mr.  Hancock's  plan  without  the  least  encroachment  upon  the 
writing.  The  thickest  ledgers  thus  bound,  open  as  easily  as  paper  in  quire,  and  may  be 
written  on  up  to  the  innermost  margin  of  the  book  without  the  least  inconvenience. 

BooKBijiDixo,  3/<?c/iamca/.— An  ingenious  invention,  for  which  Mr.  Thomas  Richards 
of  Liverpool,  bookbinder,  obtained  a  patent  in  April  1842.  He  employs,  first  a 
mechanism  to  sew,  weave,  or  bind  a  number  of  sheets  together  to  form  a  book  in- 
stead of  stitching  them  by  hand ;  2dly,  a  table  which  slides  to  and  fro  to  feed  or  supply 
each  sheet  of  paper  separately  into  his  machine ;  also  needle  bars,  or  holders,  to  present 
needles  with  the  requisite  threads,  for  stiching  such  sheets  as  they  are  supplied  with 
in  succession.  He  has,  moreover,  a  series  of  holding  fingers,  or  pincers,  suitably  pro- 
vided with  motions,  to  enable  them  to  advance  and  clasp  the  needles,  draw  them 
through  the  sheets  of  paper,  and  return  them  into  their  respective  holders,  after  thread- 
ing or  stitching  the  sheet ;  lastly,  there  are  arms  or  levers  for  delivering  each  sheet 
regularly  upon  the  top  of  the  preceding  sheets,  in  order  to  form  a  collection  or  book 
ot  such  sheets,  ready  for  boarding  or  finishing.  A  minute  description  of  the  whole 
apparatus,  with  platen,  is  given  in  Newton's  Journal,  C.  S.  xxiii.  157 
BORACIC  ACm. 

Quantities  imported  .       .       .       , 
Quantities  exported 
Kt'tained  for  consumption 
Nett  revenue         .... 
The  duty  was  repealed  in  1845. 
BOR  ACIC  ACID  LAGOOXS.     Before  the  discovery  of  this  acid  in  the  time  of  the 
Grand  Duke  Leopold  I.,  by  the  chemist  Haefer,  the  fetid  odor  developed  by  the  sul- 
phuretted hydrogen  gas,  and  the  disruptions  of  the  ground  occasioned  by  the  appear- 
ance of  new  SoJfio7ii  or  vents  of  vapor,  had  made  the  natives  regard  them  as  a  dia- 
bolical scourge,  which  they  sought  to  remove  by  priestly  exorcisms;  but  since  science 
lias  explained  the  phenomena,  the  fumachi  have  become  a  source  of  public  prosperity 
and,  tvere  they  to  cease  would  be  prayed  to  return.     The  vapors  which  issue  from 
these  lakes  keep  the  waters  always  at  a  boiling  temperature ;  hence,  after  impregnation 
for  20  or  30  hours  by  the  steams  of  the  highest  lake,  they  draw  off  the  waters  into  a 
second  lake  to  suffer  a  fresh  impregnation.     Thence  they  are  drawn  into  a  third,  and 
so  on  till,  they  reach  the  lowest  receptacle.     In  this  passage,  they  get  charged  with 
one-half  per  cent,  of  boracic  acid.     They  are  then  concentrated  in  leaden  reservoirs 
by  the  heat  of  the  vapors  themselves.  * 

The  liquid,  after  having  filled  the  first  compartment,  is  diffused  very  gradually  into 
the  second,  then  into  the  third,  and  successively  to  the  last,  where  it  reaches  such  a  state 
of  concentration  that  it  deposits  the  crystallized  acid  ;  the  workmen  remove  it  immedi- 
ately by  means  of  wooden  scrapers.  This  mode  of  gradual  concentration  is  vprv  inge- 
nious, and  requires  so  few  hands  that  it  may  almost  be  said  that  the  acid  is  obtained 
without  expense.  From  1818  to  1845  the  quantity  of  acid  manufactured  was  33  349  095 
Tuscan  pounds.     From  1839  to  1845  the  mean  quantity  has  been  2,500,000  pounds 

Thus  in  estimating  the  product  at  7,600  pounds  per  day,  the  quantity  of  saturated 
'^^f-  Tv"^  T  .      ^^«y«Pe'-ate  is  1,500,000  lbs.  daily,  and  annually  547,500,000  lbs. 

This  labor  brings  to  Tuscany  ten  millions  of  francs  :  it  is  surprising  that  it  should 
have  remained  unproductive  for  so  many  aged,  and  that  it  should  have  been  reserved 
for  the  skill  of  M.  Dardarel,  now  Count  of  Mote  Corboli,— before  1818  a  simple 
wandering  merchant,  entirely  unacquainted  with  scientific  researches,  to  discover  the 
nature  of  the  fugitive  vapors,  and  render  them  a  source  of  inexliaustible  wealth 

The  violence  with  which  the  scalding  vapors  escape  gives  rise  to  muddy  exiJlosions 
when  a  lake  has  been  drained  by  turning  its  waters  into  another  lake.  The  mud  is 
then  thrown  out,  as  solid  matters  are  ejected  from  volcanoes,  and  there  is  formed  in  the 
bottom  of  the  lake  a  crowd  of  those  little  cones  of  eruption,  whose  activity  and  play 
are  generally  from  120°  to  145°  Centigrade,  and  the  clouds  which  they  form  in  the 
lagoons  constitute  true  natural  barometers,  whose  greater  or  less  density  rarely  disap- 
points the  predictions  that  they  announce.  j  j         f 


BORAX. 


233 


Th^S.? i^*in  IJtK  ?  ^ -""^  compound  of  boracic  acid  and  soda,  found  abundantly  in 
Thibet  and  in  South  America.     The  crude  product  from  the  former  locality  was  imported 

bvanrocess  kenfV^  "^^  ^^  '*''^«''  ^'^^  ^^«  P'^"^^^  ^'"^^  '^^'  ^^hering  fatty  Tat  ter 

SiZir^iHn^c,\he^"fJr'  '"""'  ^^'^'  >'""^'^^"^  ^"'^  '^^  ^"^^^^  and  which  consisted 
chiefly  in  boiling  the  substance  in  water  with  a  little  quicklime. 

kaU  Tis  'o^nbLT'!!  'narrj""'',.' ''To'  '?^'''  ""''  "*"'  ^^"^'oWe  colors  like  .n  al- 
opaque  in  ^^d  v  almolL,i  .L  ^"^  ?  "^^  "^'""S  ''"'"■  "  effloresces  and  becomes 
tt  S  a  Httle  ih^vTf)f,.^fS  "r  "''''^"^  '"-"'nous,  by  friction,  in  the  dark.    It  melts  at 

^^ThTn'-    •'"^^"^.°"''^'^»"«d.i'""-i"tfa%£s|-iio\t.?ub^L'cT^     "  ""• 

The  following  is  the  improved  mode  of  purlfyins  borav     Th.^r-.n^  f     .  i 
be  broken  into  small  lumps,  and  spread  unon  a  filler  lf,!S  Jit      ,5  "^■*'?''  ""J" 
which  a  piece  of  cloth  is  stretched  upon  a  wooden  frame      TheMnf  ^'"S  """" 

(sp.  gr.  1-033)  until  the  liquor  comes  off  nearly  colorless-  thev are  then  HrMfZi       j     . 

getting  overstocked     ThT^Ltl^  .-      centimes,  m  consequence  of  the  market 

thJ  ^  "versiocKea.     ifte  annual  consumption  of  France  in  182*?  wn«  9^  nnn  L-.1..C    ^^a 

on  which  account  the  conner  «=hn»i,i  L^r      ^"^  '  *  "^^^^  effervescence  ensues, 

contain  the  CuorJ     When  th^  Ih  i     ^r^""^  F^^^^^  ^^P^^^y  than  is  sufficient  ii 


and  blanl-,.ic    f«  J:  7C     "'""'='  °""  "^^  copper  must  be  covered  with  a  tisht  lid 

finished.     The  Ither  water    fdr^^^^^^  S?'  ^7"°^T'  '?'  .<=^y«tallization  is  usually 

for  the  purpose  of  dSsoT^i^^  /rest  cT^als^rsodr'^^^^^^^^^^  ''i^^'^'^  ""^"^ 

detached  with  chisels  rf^di^^nW  in  vTW-        ^^  soda.     1  he  above  crystals  are  carefully 

of  carbonlte  of  s^a'    TMssltim.^  ^°'  "^"^  ^^  ^"°«"  '^  ^'^^^ 

(1000  kilos  )  of  borax  should  hrHi/^  ^'  ^'P*  ^''  ^'^^^^  5  and,  at  least,  one  ton 
•narketable  size  menever  ^hJ«  J  f-  ''t^  ^l  ^"'"'  ^^  ^^^^^  ^^  ^^tain  crystals  of  a 
K-e  crj' taUizL  lead  chests  of  th.  1^  ^' •  ^'"'"^f  ^°"'"^  ^^^'  ^'  "^"^^  ^^  "^^  ofi"  into 
Ws,  enclosed  iiwoSen  frames  «nd  T  ""^  ^^^'-^^l  truncated  pyramids,  furnished  with 
continuous  bu^n^rthereSiri^^^^^^^^  T^'  *^  ^^^^"^  '^^  ^'^^''     ^^r  a 

^kes  a  long  Ume   o^omniete  i^^^^^^^^^  18  vessels  of  this  kind;  as  the  solution 

J^  crystals\re  takenZtuh  cwS  Ser^^^^^^^^  ""t^'V'  T  ^'  ^^^  ^'^  '^^'^  ^ 
^s  become  cold.  cmsels,  alter  the  liquor  has  been  drawn  ofl;  and  the  whole 

tam^'n^rfiny'pir^^  ""'"^f'  7^^^^^^  from  the  lakes  of  Tuscany,  con- 


i! 


Ifll 


?     (I 


i  I 


234 


BORAX. 


According  to  Wittstein,  the  commercial  boracic  acid  is  compoaed  as  follows: — 


Sulphate  of  manganese 
iron 
alumina 
lime     - 


Water 


magnesia         .            -  -  - 

ammonia         .            -  -  - 

soda    -            -            -  -  - 

potash              _            .  -  - 

salammonia     -            -  -  - 

silica  (in  solution)      -  -  -      ^ 
sulphuric  acid  (combined  with  the  boracic) 
crystallizable  boracic  acid 


-  A  trace 

-  0-365 

-  0-320 

-  1-018 

-  2-632 

-  8-608 

-  0-91'7 

-  0-369 

-  0-298 

-  1*200 

-  1-322 

-  76-494 

-  6-557 


100-000 


Dry  borax  acts  on  the  metallic  oxides  at  a  high  temperature,  in  a  very  remarkable 
manner,  melting  and  vitrifying  them  into  beautiful  colored  glasses.  On  this  account 
it  is  a  most  useful  reagent  for  the  blowpipe.  Oxide  of  chrome  tinges  it  of  an  emerald 
green ;  oxide  of  cobalt,  an  intense  blue ;  oxide  of  copper,  a  pale  green ;  oxide  of  tin, 
opal;  oxide  of  iron,  bottle  green  and  yellow;  oxide  of  manganese,  violet;  oxide  of 
nickel,  pale  emerald  green.  The  white  oxides  impart  no  color  to  it  by  themselves. 
In  the  fusion  of  metals  borax  protects  their  surface  from  oxidizement,  and  even  dis- 
solves away  any  oxides  formed  upon  them;  by  which  twofold  agency  it  becomes  an 
excellent  flux,  invaluable  to  the  goldsmith  in  soldering  the  precious  metals,  and  to 
the  brazier  in  soldering  copper  and  iron.  i.      v     •    u 

Borax  absorbs  muriatic  and  sulphureous  acid  gases,  but  no  others,  whereby  it  be 
comes,  in  this  respect,  a  useful  means  of  analysis.  ,  ,      • 

The  strength  or  purity  of  borax  may  be  tested  by  the  quantity  of  sulphuric  acid 
requisite  to  neutralize  a  given  weight  of  it,  as  indicated  by  tincture  of  litmus. 

When  mixed  with  shellac  in  the  proportion  of  one  part  to  five,  borax  renders  that 
resinous  bodv  soluble  in  water,  and  forms  with  it  a  species  of  varnish. 

Boracic  acid  is  a  compound  of  31  19  of  boron  and  68-81  oxygen,  in  100  parts.  Iti 
prime  equivalent  referred  to  oxygen  100,  is  871-96.  .       i   i       v 

The  following  process  for  refining  the  native  Indian  borax,  or  tmcal,  has  been  pub- 
lished by  MM.  Robiquet  and  Marchand : — 

It  is  put  into  large  tubs,  covered  with  water  for  3  or  4  inches  above  its  surface,  and 
stirred  through  it  several  times  during  six  hours.  For  400  lbs.  of  the  tincal  there 
must  now  be  added  1  lb.  of  quicklime  diffused  through  two  quarts  of  water.  Next 
day  the  whole  is  thrown  upon  a  sieve,  to  drain  oflf  the  water  with  the  impurities, 
consisting,  in  some  measure,  of  the  fatty  matter  combined  with  the  lime,  as  an  inso- 
luble soap.  The  borax,  so  far  purified,  is  to  be  dissolved  in  2i  times  its  weight  of 
boiling  water,  and  8  lbs.  of  muriate  of  lime  are  to  be  added  for  the  above  quantity  of 
borax.  The  liquor  is  now  filtered,  evaporated  to  the  density  of  18°  or  20°  B.  (114  to 
1-16  sp.  grav.),  and  set  to  crystallize  in  vessels  shaped  like  inverted  pyramids,  and 
lined  with  lead.  At  the  end  of  a  few  days,  the  crystallization  being  completed,  the 
mother  waters  are  drawn  off,  and  the  crystals  are  detached  and  dried.  The  loss  of 
weight  in  this  operation  is  about  20  per  cent. 


Quantities  imported    - 
Quantities  exported    - 
Retained  for  consumption 
Nett  revenue 


1841. 

1842. 

1848. 

1844 

cwts. 

_^ 

3581 

847 

1427 

cwts. 

— 

2435 

2940 

3637 

cwts. 

— . 

7798 

889 

349 

£ 

866 

161 

5 

4 

The  duty  on  borax  has  been  repealed. 

BoEAX,  Dry.  A  considerable  saving  of  expense  in  manufacturing  borax,  and  a  more 
ready  application  of  the  borax  to  use,  are  proposed  by  Saulter,  as  follows: — ^Take 
about  38  parts  of  pure  crystallized  boracic  acid,  pounded  and  sifted;  mix  them  well 
with  45  parts  of  crystals  of  carbonate  of  soda  in  powder;  expose  the  mixture  upon 
wooden  shelves  to  heat  in  a  stove  room ;  and  rake  it  up  from  time  to  time.  The  bo- 
racic acid  and  the  alkali  thus  get  combined,  while  the  carbonic  acid  and  water  are  ex- 
pelled; and  a  perfect  dry  borax  is  obtained. 


BOUGIE. 


235 


BOTTLE  MANUFACTITIE.    The  fol- 
lowing   mechanism   for    moulding   bottles 
forms  the  subject  of  a  patent  obtained  by 
Henry  Rickets  of  Bristol,  in  1822.   Fig.  176 
is  a  section  of  the  apparatus,  consisting  of 
a  square  frame,  a  a,  of  iron  or  wood ;  this 
is  fixed  in  a  pit  formed  in  the  floor ;   b  b 
is  the  base  of  the  frame,  with  an  aper- 
ture for   knocking   up  the  bottom  of  the 
bottle ;  c  c  are  four  legs   secured    to   the 
frame- floor   b,   upon  which   the    mould   is 
supported.     The  platform  or  stand  of  the 
mould  d  d  has  an  opening  in  its  centre  for 
the    introduction    of   the    bottom    of   the 
would,  which  is  raised  against  the  bottom 
of  the  bottle  by  the  knocker-up;    e  e  are 
the  sides  of  the  mould ;  and  //  is  the  top 
of  the  mould  in  two  pieces,  turning  over 
upon  the  joints  at  g  g,  so  as  to  form  the 
neck  of  the  bottle ;  h  h  are  levers  or  arms 
for  raising  and  depressing  the  top  pieces; 
i  i  is  a  horizontal  shaft  or  axle,  turning  in 
bearings  at  each  end,  from  which  shaft  two 
levers,  k  k,  extend ;  these  levers  are  con- 
nected by  upright  rods,  I  /,  to  the  levers  or 
arms,  h  A,  of  the  top  pieces  //, 

The  weight  of  the  arms  h  h,  and  rods  /  /,  will,  by  their  gravity,  cause  the  top  pieces 
to  o^en,  as  shown  by  the  dotted  lines;  in  this  situation  of  the  mould,  the  melted  glass 
is  to  be  introduced  by  a  tube  as  usual.  The  workman  then  steps  with  one  foot  upon 
the  knob  m,  which  forces  down  the  rod  n,  and  by  means  of  a  5  hort  lever  o,  extending  from 
the  shaft  t,  forces  down  the  top  pieces  /,  and  doses  the  mouM,  as  .*  een  in  the  figure ;  the 
glass  is  then  made  to  extend  itself  to  the  shape  of  the  mould,  by  blowing  as  usual,  so  as 
to  form  the  bottle,  and  the  workman  at  this  time  putting  his  other  foot  upon  the  knob  p, 
depresses  the  rod  q,  and  hence  raises  the  bottom  of  the  mould  by  means  of  the  knocker- 
up,  r,  so  as  to  form  the  bottom  of  the  bottle. 

At  the  bottom  of  the  mould  a  ring  is  introduced  of  any  required  thickness,  for  the 
purpose  of  regulating  the  capacity  of  the  bottle ;  upon  which  ring  it  is  proposed  to 
raise  letters  and  figures,  as  a  mould  to  imprint  the  maker's  name  and  the  size  of  the 
bottle.  These  moulds  can  be  removed  and  changed  at  pleasure.  Under  the  knob  p, 
a  collar  or  washer  is  to  be  introduced,  of  any  required  thickness,  to  regulate  ihe 
knocking  up  of  the  bottom,  by  which  a  perfect  symmetry  of  form  is  presented.  In 
order  to  make  bottles  of  diflerent  sizes  or  forms,  the  mould  is  intended  to  be  removed, 
and  its  place  supplied  by  another  mould  of  different  dimensions  and  figure ;  the  lower 
parts  of  all  the  moulds  being  made  to  fit  the  same  frame.  Such  a  mould  ought  to  be 
prescribed  by  legislative  enactment,  with  an  excise  stamp  to  define  the  capacity  of  every 
bottle,  and  thereby  put  an  end  to  the  interminable  frauds  committed  in  the  measure  of 
wine  and  all  other  liquors  sold  by  the  bottle. 

BOUGIE.  A  smooth,  flexible,  elastic,  slender  cylinder,  introduced  into  the  urethra, 
rectum,  or  oesophagus,  for  opening  or  dilating  it,  in  cases  of  stricture  and  other  diseases. 
The  invention  of  this  instiument  is  claimed  by  Aldereto,  a  Portuguese  physician,  but  its 
form  and  uses  were  first  described  by  his  pupil  Amatus,  in  the  year  1554.  Some  are 
solid,  and  some  hollow ;  some  corrosive,  and  some  mollifying.  They  generally  owe  their 
elasticity  to  linseed  oil,  inspissated  by  long  boiling,  and  rendered  drying  by  litharge. 
This  viscid  matter  is  spread  upon  a  very  fine  cord  or  tubular  web  of  cotton,  flax,  or  silk, 
which  is  rolled  upon  a  slab  when  it  becomes  nearly  soUd  by  drjing,  and  is  finally  polished 
in  the  same  way. 

Pickel,  a  French  professor  of  medicine,  published  the  following  recipe  for  the  com- 
position of  bougies.  Take  3  parts  of  boiled  linseed  oil,  one  part  of  amber,  and  one 
of  oil  of  turpentine;  melt  and  mix  these  ingredients  well  together,  and  spread  the 
compound  at  three  successive  intervals  upon  a  silk  cord  or  web.  Place  the  pieces 
80  coated  in  a  stove  heated  to  150°  F.;  leave  them  in  it  for  12  hours,  adding  15 
or  16  fresh  layers  in  succession,  till  the  instruments  have  acquired  the  jn-oper  size. 
i'oUsh  them  first  with  pumice-stone,  and  finally  smooth  with  tripoli  and  oil.  This  pro- 
^^^^s.the  one  still  employed  in  Paris,  with  some  slight  modifications;  the  chief  of 
Which  is  dissolving  in  the  oil  one  twentieth  of  its  weight  of  caoutchouc  to  render  the 
*]J°s^'*'»ce  more  solid.  For  this  purpose  the  caoutchouc  must  be  cut  into  slender 
shreds,  and  added  gradually  to  the  hot  oil.    The  silk  tissue  must  be  fine  and  open,  to 


--* 


•i}f 


]) 


!, 


\ 


236 


BRAIDING  MACHINE. 


admit  of  the  composition  entering  freely  among  its  filaments.  Each  successive  layer 
ou^ht  to  be  dried  first  in  a  stove,  and  then  in  the  open  air,  before  another  is  applied. 
This  process  takes  two  months  for  its  completion,  in  forming  the  best  bougies  called 
elastic ;  which  ought  to  bear  twisting  round  the  finger  without  cracking  or  scaling,  and 
extension  without  giving  way,  but  retracting  when  let  go.  When  the  bougies  are  to  be 
hollow,  a  mandril  of  iron  wire,  properly  bent  with  a  ring  at  one  end,  is  introduced  into 
the  axis  of  the  silk  tissue.  Some  bougies  are  made  with  a  hollow  axis  of  tin  foil  rolled 
into  a  slender  tube.  Bougies  are  also  made  entirely  of  caoutchouc,  by  the  intervention 
of  a  solution  of  this  substance  in  sulphuric  ether,  a  menstruum  sufficiently  cheap  in 
France,  on  account  of  the  low  duty  upon  alcohol.  There  are  medicated  bougies,  the 
composition  of  which  belongs  to  surgical  pharmacy.  The  manufacture  of  these  instru- 
ments of  various  kinds  forms  a  separate  and  no  inconsiderable  bianch  of  industry  at 
Paris.     MM.  Feburger  and  Lamotte  are  eminent  in  this  line. 

BRACES.  (Bretelks,  Fr. ;  Hosentrdger,  Germ.)  Narrow  fillets  or  bands  of  leather 
or  textile  fabric,  which  pass  over  the  shoulders,  and  are  attached  behind  and  before  to 
the  waistbands  of  pantaloons  and  trousers,  in  the  act  of  wearing  them,  for  supporting 
their  weight,  and  bracing  them  up  to  the  body.  It  is  a  useful  modern  invention,  super- 
seding the  necessity  of  girding  the  belly  with  a  tight  girdle,  as  in. former  times. 

BRAIDING  MACHINE.  (Machine  a  lacets,  Fr. ;  Bortenwerkerstuhl,  Germ.)  This 
being  employed  not  only  to  manufacture  stay-laces,  braid,  and  upholsterers'  cord,  but 
to  cover  the  threads  of  caoutchouc  for  weaving  brace-bands,  deserves  a  description  in 
this  work.  Three  threads  at  least  are  required  to  make  such  a  knitted  lace,  but  11, 13, 
or  17,  and  even  29  threads  are  often  employed,  the  first  three  numbers  being  preferred. 
They  are  made  by  means  of  a  frame  of  a  verj-  ingenious  construction,  which  moves  by 
a  continuous  rotation.  We  shall  describe  a  frame  with  13  threads,  from  which  the 
structure  of  the  others  may  be  readily  conceived.    The  basis  of  the  machine  consists  of 


four  strong  wooden  uprights,  a,  figs.  177,  178,  179,  occupying  the  four  angles  of  a 
rectangle,  of  which  one  side  is  14  inches  long,  the  other  18  inches,  and  the  height  of  the 
rectangle  about  40  inches.  Fig.  177  is  a  section  in  a  horizontal  plane,  passing  through 
the  line  ah  of  fig.  l78,  which  is  a  vertical  section  in  a  plane  passing  throush  the  centre  of 
the  machine  c,  according  to  the  line  c  d,fig.  177.  The  side  x  is  supposed  to  be  the  front 
of  the  frame ;  and  the  opposite  side,  y,  the  back,  b,  six  spindles  or  skewers,  numbered, 
from  1  to  6,  placed  in  a  vertical  position  upon  the  circumference  of  a  circle,  whose  centre 
coincides  with  that  of  the  machine  at  the  point  c.  These  six  spindles  are  composed, 
1.  Of  so  many  iron  shafts  or  axes  d,  supported  in  brass  collets  e  {fig.  178),  and  ex- 
tended downwards  within  sLx  inches  of  the  ground,  where  they  rest  in  brass  steps  fixed 
upon  a  horizontal  beam.  2.  Wooden  heads,  made  of  horn-beam  or  nut-tree,  placed,  the 
first  upon  the  upper  end  of  each  spindle,  opposite  the  cut-out  beam  f,  and  the  second 
opposite  the  second  beam  g.  3,  Wooden-toothed  wheels,  h,  reciprocally  working 
together,  placed  between  the  beam  g  and  the  collet-beam  e.  The  toothed  wheels  and 
the  lower  heads  for  each  spindle  are  in  one  piece. 

The  heads  and  shafts  of  the  spindles  No.  1  and  6,  are  one  fifth  stronger  than  those  of 
the  other  spindles ;  their  heads  have  five  semicircular  grooves,  and  wheels  of  60  teeth, 
while  the  heads  of  the  others  have  only  four  grooves,  and  wheels  of  48  teeth ;  so  that 
the  number  of  the  grooves  in  the  six  spindles  L*  26,  one  half  of  which  is  occupied  with 
the  stems  of  the  puppets  i,  which  carry  the  13  threads  from  No.  1  to  13.  The  toothed 
wheels,  which  give  aU  the  spindles  a  simultaneous  movement,  but  in  different  directions, 


i 


BRAN. 


237 


are  »  disposed  as   to  bring  their   grooves  opposite   to   each  other  in  the  course  of 
rotation. 

K,  the  middle  winglet,  triple  at  bottom  and  quintuple  at  top,  which  serves  to  guide  the 
puppets  m  the  direction  they  ought  to  pursue. 

L,  three  winglets,  single  at  top  and  bottom,  placed  exteriorly,  which  serve  a  like 
purpose. 

M,  two  winglets,  triple  at  bottom  and  single  at  top,  placed  likewise  exterioriy,  and 
which  serve  the  same  purposes  as  the  preceding;  m  are  iron  pins  inserted  in  ihe  cut-out 
beam  g,  which  serve  as  stops  or  limits  to  the  oscillations  of  the  exterior  winglets. 

Now,  if  by  any  moving  power  (a  man  can  drive  a  pair)  rotation  be  impressed  upon 
the  large  spindle  No.  I,  in  the  direction  of  the  arrow,  all  the  other  spindles  will  neces- 
sarily pursue  the  rotatory  movement  indicated  by  the  respective  arrows.  In  this  case, 
the  13  puppets  working  in  the  grooves  of  the  heads  of  the  spindles  will  be  carried  round 
simultaneously,  and  will  proceed  each  in  its  turn,  from  one  extremity  of  the  machine  to 
the  opposite  point,  crossing  those  which  have  a  retrograde  movement.  The  13  threads 
united  at  the  point  n  situated  above  the  centre  of  the  machine,  will  form  at  that  point 
the  braid,  which,  after  having  passed  over  the  pulley  o,  comes  between  the 
two  rollers  p  q,  and  is  squeezed  together,  as  in  a  flatting-mill,  where  the 
braid  IS  ca  endered  at  the  same  time  that  it  is  delivered.  It  is  obvious 
that  the  roller  p  receives  its  motion  from  the  toothed  wheel  of  the  spindle 
J\o.  d,  and  from  the  intermediate  wheels  b,  s,  t,  as  well  as  from  the  endless 

^r*"?^  ^'  ,y^*^^  *^"^^^  ^^  P'^^P^^  sP^ed  the  wheel  w,  fixed  upon  the  shaft 
of  the  roller  p. 

The  braid  is  denser  in  proportion  as  the  point  N  is  less  elevated  above 
the  tops  of  the  puppets;  but  in  this  case,  the  eccentric  motion  of  these 
puppets  IS  much  more  sensible  in  reference  to  that  point  towards  which 
^j  all  the  threads  converge  than  when  it  is  elevated.  The  threads,  which 
must  be  always  kept  equally  stretched  by  means  of  a  weight,  as  we  shall 
presently  see,  are  considerably  strained  by  the  traction,  occasioned  by  the 
constantly  eccentric  movement  of  the  puppets.  From  this  cause,  braid- 
ing machines  must  be  worked  at  a  moderate  velocity.  In  general,  for 
fine  work,  30  turns  of  the  large  spindle  per  minute  are  the  utmost  that  can 
safely  be  made. 

The  puppet  or  spindle  of  this  machine,  being  the  most  importan 
piece,  I  have  represented  it  in  section,  upon  a  scale  one  fourth  of  its  ac- 
tual size,  fig.  179.  It  is  formed  of  a  tube,  a,  of  strong  sheet  iron  weU 
brazed ;  6  is  a  disc,  likewise  of  sheet  iron,  from  which  a  narrow  fillet,  c, 
rises  verticaUy  as  high  as  the  tube,  where  both  are  pierced  with  holes! 
d  «,  through  which  the  thread  /  is  passed,  as  it  comes  from  the  bobbin! 
g,  which  turns  freely  upon  the  tube  a.  The  top  of  this  bobbin  is  conical 
and  toothed.  A  small  catch  or  detent,  A,  moveable  in  a  vertical  di- 
rection round  t,  falls  by  its  own  weight  into  the  teeth  of  the  crown  of 
the  bobbin,  in  which  case  this  cannot  revolve ;  but  when  the  detent  is 
raised  so  far  as  to  disengage  the  teeth,  and  at  the  same  time  to  pull  the 
thread,  the  bobbin  turns,  and  lets  out  thread  till  the  detent  falls  back  into 
these  same  teeth. 


;^;y 


179 


it  Th«  ♦  r  .t  f  ^"  ^[  *'"*'"  ^'"'^'  ^'  '^  ^''^^^^  ^'^^^  ^  small  weight,  Z,  melted  upon 
L  rro  top  of  this  skewer  has  an  eye  in  it,  and  the  bottom  is  recurved  as  is  shoAvn  in 
b^itinn  'j^  that  supposing  the  thread  comes  to  break,  this  skewer  falls  into  the  actual 
position  in  the  figure,  where  we  see  its  lower  end  extending  beyond  the  tube  a,  by 
about  J  of  an  inch;  but  as  long  as  the  thread  is  unbroken,  the  skewer  fc,  which  scItm 
below^the  tube^^  ^*'"'^'  °  *^^  eccentric  movement  of  the  puppet,  does  not  pass  out 

w3^1'  disposition  has  naturally  furnished  the  means  of  causing  the  machine  to  stop. 
Whenever  one  of  the  threads  breaks.  This  inferior  protrusion  of  the  skewer  pushes  in 
iU=  p. ogress  a  detent  which  instantly  causes  the  band  to  slide  from  the  driving  pulley  to 
ine  loose  pulley.  Thus  the  machine  cannot  operate  unless  aU  the  threads  be  entire.  It 
as  fhpj"{f'"?'  A.^  operative,  who  has  3  or  4  under  her  charge,  to  mend  the  threads 
stopped  substitute  full  bobbins  for  empty  ones,  whenever  the  machine  is 

vilw  ^^^^^"^^f""^^'  though  it  does  not  move  quickly,  makes  a  great  deal  of  noise,  and 
them  tn  t^  '  n  T'^'  T'f.^v^  ^°°^^^^  ^^^^^^  made  of  metal  instead  of  wood.  For 
Tf^V^  ^r   T    '  they  should  be  made  with  the  greatest  precision,  by  means  of  appropri- 

BR  A  v^""'/?"^?^^  the  teeth  of  the  wheels,  and  the  other  peculiar  parts. 
thP  holf*    /      **v    J  -^^^vGerm.)     The  husky  portion  of  ground  wheat,  separated  by 
dearini  nrn  •       i?"k*  ^It  ^.advantageously  employed  by  the  calico  printers,  in  the 

wearing  process,  m  which,  by  boUing  in  bran-water,  the  coloring  matters  adhering  to  the 


■••mwr^w!mm'^^^''m»mfmim 


H 


:i 

1            : 

■ 

238  BRANDY. 

.  r  ™«^.i*.rprl  ffoods  as  well  as  ihe  dun  matters  which  cloud  the  mor- 
non-mordanled  parts  ^^  "^^^^f '^^^SXiwe  Teries  of  researches  concerning  the  operation 
danted  portions,  are  removed.  A  Y^"^^f^fJ4'\  ^^^^  distinguished  chemist  and  cahco 
of.bran  in  such  <:^!!  J^^.^^if^^^^^^^^  in  the  ninth  number  of  theBuUeUn 

nrs:>cSdSe  de^  Nine  sets  of  experiments  are  recorded,  wh.ch 

justified  the  following  conclusions.  ^    ^^^  ebullition 

ing  either  the  grounds  or  the  figures.  ^rinrinal  obiect  is  to  clear  white 

n'Va'v  «p"erSSeTconcnr  to  prove  that  flour  is  altogether  useless  for  the  clearing 
boU,  Tnd  that  Ler  bran  is  inferior  for  «t'j^.n''»Uh°wheatTan  are  distinguishable  by 
Jr  l^el^XlgStr^f^  S^o?  tf  pS  :KTi^rand  esp^eiall,  with 
"r  ^tS  \st  Vantage' ia  aldt^  Z'p  wThe  bran  boil ,  though  a  little  potash  or  sod. 

may  be  properly  introduced  ^h'^*"' If nower^TaTtke  Hour  and  the  starch  are  of 
7.  The  peUicle  of  the  bran  is  the  most  powerful  part,  ">«  "°ur 

no  use  in  clearing  goods,  but  the  ^""'""^''''f /"rfoUowina  way  In  proWion  " 
bran  has  considerable  efficacy  and  s^^^^^^^^^^^ 

the  mucilaginous  substance  dissolves  V'l^J^;?""'  '  c  t^^em.    Accordingly,  when 

^usI^Uafrd^rin  a^'ea^  'SZ^X^^S^^^^r  which  it  had  absorbed 

'The'LCng  chemical  examination  of  b«n  U  intere^in..  ./j-^^l'iJTg^^ul 
at  successive  times  with  water ;  the  deco«K.ns,  bemg  6 '^^^'^^^yX'rded  by  evai^ration 
deposite,  which  was  separated  by  decantation.    The  c'ear  liquor^  J  mucilage,  a 

-o-:^  .o^t,=,°USrgrsteCr/tt:rom"etric  water  of  the  bran 

ously  made.  •     ♦!,•„  «o«ntrv  tn  ardent  soirits  distilled  from  wine, 

BRANDY.  The  name  given  m  ^^//°'^'^^'^,/^°.^'^^^:^Pte  portion  of  a  peculiai 
and  possessed  of  a  peculiar  taste  and  A^;^/' ^^%^^°„^,^^,^"  ^  of  the  fermenSed  sub- 
volalSe  oil.     Each  variety  of  alcohol  has  an  aroma  f/^J^^^^^  sugar-cane,  rice, 

stance  from  which  it  is  procured;  -^^^^^^''^^J^^  Procured  from  different  growths 
com,  or  potatoes ;  and  it  may  be  distinguished  «^_«^^  .'t^^  P^^"^^^^^  Cognac,  Aunis, 

^n^^o^ngriiochlnt  Srf^%te^o\T??a%^^^^^^^^  -ogni-ble  by 

'\XLlerlowed\y  experiments,  that  the  disagreeable  taste  of  the  spirits  distilled 

f-ient  to  taint  a  pipe  of  600  litres  of  fine  flavored  spirit. 

The  most  celebrated  of  the  French  brandies,  those  of  Cognac  and  Armagnac,  "e  sli^t- 
IvTecti^d  to  only  from  0-935  to  0-922;  they  contain  more  than  half  their  ^^lll\olvr^' 
t/«aHrome  over  therefore  highly  charged  with  the  fragrant  essential  oil  of  the  husk  of 
ter,  and  come  over  V^ereiore     .    X         ^  ^.^  ^^  ^^^^^^^  ^o  a  much  higher 

'^^  ^''^thV  dealer 'on  ^leivTngUat  Paris,  rSlices  it  to  the  market  proof  by  the  addition 
•^'/''r;.  P  h?.Wv  Lvored  w^^^^  and  water;  but  he  cannot  in  this  way  produce  so 

of  a  httle  1^2,  y;S  asTh^^^  of  distillation  of  the  Cognac  wme.    If  the 

-t  n^^'^rc^^h'brlXVvi^^^^^^^^^  ^  paper,  owing  to  a  minute 

portTof%Le1^;^^^^^^^^^^^  -me  acetic  ether,  and,  when  long  kept  m  oak 


BRASS. 


289 


casks,  a  little  astringent  matter.  The  foUowing  formula  may  be  proposed  for  converting 
a  silent  or  flavorless  corn  spirit,  into  a  factitious  brandy.  Dilute  the  pure  alcohol  to  thf 
proof  pitch,  add  to  every  hundred  pounds  weight  of  it  from  half  a  pound  to  a  Znd  of 
argoKcrudewinestone  dissolved  in  water,  a  little  acetic  ether,  and  pVench  wineVvLecar 
some  bruised  French  plums,  and  flavor-stuff  from  Cognac;  then  distil  the  mkture  with  a 
gentle  fire,  m  an  alembic  furnished  with  an  agitator  mixiure  wiin  a 

iJ^Vr^%Z^'''^A'''''^^V^',  P^y  ^^  ^^^^'•^d  ^ith  nicely  burned  sugar  (caramel)  to 
Sirk  '  roughened  in  taste  with  a  few  drops  of  tincture  of ^atech^^r  oak° 

The  above  recipe  will  afford  a  spirit  free  from  the  deleterious  drugs  too  often  used  to 
flS'-^'wh  Z'"''"'^'  '^'  ^f  ?i^ating  power  of  British  brandies;  one  wSch  may  b^^ck^ 

2l  A  c^  °^T™^  ^  ^^^''^''^'  ^"  ^'^y  shape,  can  ever  be.  ^ 

..n^      Tt        ^r^'^'^l  cuivre  Jaune,  Fr. ;   Mesnng,  Germ.)    An  aUoy  of  copper  and 

copper  cCL'r^^h^r''?"'f  '^  ^'"^'^'^^  ^^^^'^'^  ^^PP^^'  ^'^^  ^!^ho^^^ 
copper  clippings,  with  caicmed  calamine  (native  carbonate  of  zinc)  and  charcoal  in  « 

crucible    and  exposing  them  to  bright  ignition.     Three  parts  of  copper  wer^^f^' for 

three  of  calamine  and  two  of  charcoal.     The  zinc  reduced  to  the  metalhrstate  bv  thi 

agency  of  the  charcoal,  combined  with  the  copper,  into  an  allov  which  <Wr^«fL!^^^ 

ing,  a  lump  at  the  bottom  of  the  crucible.    Seveml  of  thesTLTngt^^^^^ 

em  Tn   ,7«rr'"'t^-  '""T  ''^^'^''  ^^^  ^^^  '^^^'''    James  EmeLTob taLd  a  pa 
tent,  m  178  ,  for  making  brass  by  the  direct  fusion  of  its  two  metallic  element  and  It 
IS  now  usually  manufactured  in  this  way.  "ieiauic  elements,  and  it 

It  appears  that  the  best  proportion  of  the  constituents  to  form  fine  brass  is  one  nrim*. 
equivalent  of  copper=63it+one  of  zinc:=32.3  ;  or  very  nearly  2  partsTciDDer  to  H? 
zinc  The  bright  gold  colored  alloy,  caUed  Prince'sT or  PriLe  WtWaJ  Si  tl 
country  consists  apparently  of  two  primes  of  zinc  to 'one  of  copperfor  of  neSy  eo^ 
parts  of  each.  Brass,  or  hard  solder,  consists  of  two  parts  of  br4ss  and  o^  ofTni 
melted  together,  to  which  a  little  tin' is  occasionally  adLd%u^t  X  ^hLoTderrst 
be  ver5'  strong  as  for  brass  tubes  that  are  to  undergo  drawing,  twTthirrof  a  nart  of 
zmc  are  used  for  two  parts  of  brass.  Mosaic  gold,  accoTdifg  t7the  specm^ 
which^rn^  Hamilton's  patent,  consists  of  100  parti  of 'copper,  and  LmllZf^Tzinl 
r^s  of  zTnc  P^^P^'^^^"-     ^ath  metal  is  said  to  consist'of  32  parts  of  biLs  Sd  ^ 

The  button  manufacturers  of  Birmingham  make  their  pUtin  with  8  parts  of  brass  and 

RrbrUs    the' To^l?w'T"'  ^^'^  ^"  ^'}''  '^  ''^^'^^  ''^^  zinc,  aKad.  ""^ 

^onc- ♦     f^'  Tombak  of  some,  (not  of  the  Chinese,  for  this  is  white   Conner 'V 

2Ttotnf  r'r  fn^Pf  ^"'^  ^"'^  ^T  '^^"  ^°  ^«  '^^  composition  of  braS ;  bein^Xm 
mVhl    t     h  ^^^./T"'  i^^  ^^  ^^"  '^«^^-     At  the  famous  brass  works  of  H^ 

Kr«ci'  ^  ^  P^^-'!"'\y  described,  11  parts  of  copper  are  alloved  with  2  of  zinc  ?ntf^?d 
«n^n  r  n^i'u  ?^-^'''  ^^  °^^^  ^^^^  are  afterwards  rolled  into  sheets  From  such 
an  alloy  the  Dutch  foU,  as  it  is  caUed,  is  manufactured  at  Niirnberg ;  pfnchbeck  sLX 

^^l-W^gl^^^""  ^"^  ^  ""^  ""'*^'  ''^^'^''^^  ^^Ited,  and  suddenly  incorporated  by 

«  iV}^  ^m''^"'  ""[  ^^V'l^  ^^'^  ""^t^^^  «^  ^"^1*  different  fusibilities  as  copper  and  zinc 
miX  i"'''^''  T^'K""^  '>^  ^^"""^  °^^tal  by  the  combustion,  to  which  ufsS^  prone' 
rirlt  ^""P^'^"?'  ^*'  '^reality,  their  mutual  affinities  seem  to  prevent  thTCin 
iZTa  "^''  ^  ^^^  'P/'^y  absorption  of  the  zinc  into  the  substance  of  the  confer 
Indeed,  copper  plates  and  rods  are  often  brassed  externally  by  exposure  at  a  hTJh 
temperature  to  the  fumes  of  zinc,  and  aftewards  laminated  or'^  drawn  Ve  spuH^s 
gold  wire  of  Lyons  is  made  from  such  rods.  Copper  vessels  may  be  supe;ficiallv  convert- 
edmto  brass  by  boiling  them  in  dilute  muriatic  acid  containing  Jome  w^ne  and  zllic 

ofIomfwh«rH^ffi".,;?t^'"^  ^TV'  ^^P^''"^'  '"P'  of  copper  into  melted  zinc  till  an  alloy 
?L  oTthe  00?;^^^^^^       '°^  ^'  ^"'■°^'^'  "^  '^'''  '^'  ^^^^'  ^'^d  ^^^  the  remaining  propor^ 

zlnT^'^n^Tf-  ''^.^K^'^l  ^l'"'''  ^'  ^i:?^^"  ^^  P^^^^S'  and  melted  with  a  fresh  quantity  of 
k  n^l  «^tam  the  finished  brass.     Each  melting  takes  about  8  or  9  hours.     The  metal 

one  h^uTncV^iLk  T^^^^  '^"//^  inches  long  by  26  inches  broad,  and  from  one  thkd  to 
frame  rr«n  .p  LI  T  v"^  "  r'  *^  ?^'  ^*'^  ^^^°'  ^^abs  of  granite  mounted  in  an  iron 
sS^es*  th^  hpit  l?nl  'i'l^^  preferred  to  every  thing  else  as  a  mould,  because  it  pre- 
«\o\ecl'rVth?jlt^^^^  ^^  '''''''"^  ''  '''  ^-^-^'  '^'  ^-P^  ^«^^  «^  the  clay  Le 

intl^lh?nl^^?^  "^  T^  "fi^y  ^^"^  ^"to  sheets.  For  this  purpose  they  are  cut 
bmss  ro^n/  ''""'"'  ^''^^'^.''  commonly  about  6|  inches.  The  cvlmders  of  the 
brass  rolhng-press  are  generally  46  inches  long,  and   18  inches  in  diameter.    The 


I 


II 


(,  ■; 


r 


240 


BRASS. 


fibands  are  first  of  all  passed  cold  through  the  cylinders ;  but  the  brass  soon  becomes 
too  hard  to  laminate.  It  is  then  annealed  in  a  furnace,  and,  after  cooling,  is  passed 
afresh  through  a  rolling  press.  After  paring  off  the  chipped  edges,  the  sheets  are 
laminated  two  at  a  time :  and  if  they  are  to  be  made  very  thin,  even  eight  plates  arc 
passed  through  together.  The  brass  ia  these  operations  must  be  annealed  7  or  8  times 
before  the  sheet  arrives  at  the  required  thinness.  These  successive  heatings  are  very 
expensive ;  and  hence  they  have  led  the  manufacturers  to  try  various  plans  of  econo- 
my. The  annealing  furnaces  are  of  two  forms,  according  to  the  size  of  the  sheets 
of  brass.  The  smaller  are  about  12  feet  long,  with  a  fire-place  at  each  end,  and  about 
13  inches  wide.  The  arch  of  the  furnace  has  a  cylindrical  shape,  whose  axis  is 
parallel  to  its  small  side.  The  hearth  is  hori2ontal,  and  is  made  of  bricks  set  on  edge. 
In  the  front  of  the  furnace  there  is  a  large  door,  which  is  raised  by  a  lever,  or  chain, 
and  counterweight,  and  slides  m  a  frame  between  two  cheeks  of  cast  iron.  This  furnace 
has,  in  general,  no  chimney,  except  a  vent  slightly  raised  above  the  door,  to  prevent  the 
workmen  being  incommoded  by  the  smoke.  Sometimes  the  arch  is  perforated  with  a  num- 
ber of  holes.  The  sheets  of  brass  are  placed  above  each  other,  but  separated  by  parings, 
to  allow  the  hot  air  to  circulate  among  them,  the  lowest  sheet  resting  upon  two  bars  of 
cast  iron  placed  lengthwise. 

The  large  furnaces  are  usually  32  feet  long,  by  6|  feet  wide,  in  the  body,  and  3  feet 
at  the  hearth.  A  grate,  13  inches  broad,  extends  along  each  side  of  the  hearth, 
through  its  whole  length,  and  is  divided  from  it  by  a  small  wall,  2  or  3  inches  high. 
The  vault  of  the  furnace  has  a  small  curvature,  and  is  pierced  with  6  or  8  openings, 
which  allow  the  smoke  to  pass  off  into  a  low  bell-chimney  above.  At  each  end  of  the 
furnace  there  is  a  cast-iron  door,  which  slides  up  and  down  in  an  iron  frame,  and 
is  poised  by  a  counterweight.  On  the  hearth  there  is  a  kind  of  railway,  composed  of 
two  iron  bars,  on  the  grooves  of  which  the  carriage  moves  with  its  loads  of  sheets  of 
brass. 

These  sheets,  being  often  24  feet  long,  could  not  be  easily  moved  in  and  out  of  the 
furnace ;  but  as  brass  laminates  well  in  the  cold  state,  they  are  all  introduced  and 
moved  out  together.  With  this  view,  an  iron  carriage  is  framed  with  four  bars,  which 
rest  on  four  wheels.  Upon  this  carriage,  of  a  length  nearly  equal  to  that  of  the  furnace, 
the  sheets  are  laid,  with  brass  parings  between  them.  The  carriage  is  then  raised  by  a 
crane  to  a  level  with  the  furnace,  and  entered  upon  the  grooved  bars  which  lie  upon  the 
hearth.  That  no  heat  may  be  lost,  two  carriages  are  provided,  the  one  being  ready  to 
put  in  as  the  other  is  taken  out ;  the  furnace  is  meanwhile  uniformly  kept  hot.  This 
method,  however  convenient  for  moving  the  sheets  in  and  out,  wastes  a  good  deal  of  fuel 
in  heating  the  iron  carriage. 

The  principal  places  in  which  brass  is  manufactured  on  the  great  scale  in  England,  are 
Bristol,  Birmingham,  and  Holywell,  in  North  Wales. 

The  French  writers  affirm,  that  a  brass,  containing  2  per  cent,  of  lead,  works  more 
freely  in  the  turning  lathe,  but  does  not  hammer  so  well  as  a  mere  alloy  of  copper  and 
zinc. 

At  the  brass  manufactory  of  Hegermuhl,  upon  the  Finon  canal  near  Potsdam,  the  fol- 
lowing are  the  materials  of  one  charge;  41  pounds  of  old  brass,  55  pounds  refined  cop- 
per (gahrkupfer)  granulated  ;  and  24  pounds  of  zinc.  This  mixture,  weighing  120  pounds, 
is  distributed  into  four  crucibles,  and  fused  in  a  wind  furnace  with  pitcoal  fuel.  The 
waste  varies  from  2|  to  4  pounds  upon  the  whole. 
Fig.  180  represents  the  furnace  as  it  was  formerly  worked  there  with  charcoal ;  a,  the 

laboratory  in  which  the  crucibles  were 
placed.  It  was  walled  with  fire-bricks. 
The  foundations,  and  the  filling-in  walls 
were  formed  of  stone  rubbish,  as  being  bad 
conductors  of  heat ;  sand  and  ashes  may  be 
also  used;  6,  cast  iron  circular  grating 
plates  pierced  with  12  holes  {seefg.  181)^ 
over  them  a  sole  of  loam,  c,  is  beat  down, 
and  perforated  with  holes,  corresponding 
to  those  in  the  iron  discs ;  d,  the  ash  pit ; 
e,  the  bock,  a  draught  flue  which  con- 
ducts the  air  requisite  to  the  combus- 
tion, from  a  sunk  tunnel,  in  communica- 
tion with  several  melting  furnaces.  The 
terrace  or  crown  of  the  furnace,  /,  lies  on 
a  level  with  the  foundery  floor,  h  h,  and  is 
shut  with  a  tile  of  fire-clay,  g,  which  may 
be  moved  in  any  direction  by  means  of 
hooks  and  eyes  in  its  binding  iron  ring. 


%  180 


BRASS. 


241 


^S'  fiom  Se  ^dT  ^""  ^""'"^  '''  ^""^  '*^^°^  ^^'  '^'  '^'''^^  ^  ^''^^'^  f'o^  -bove 
Figx^  ISS,  184,  represent  the  funiaces  constructed  more  recently  for  the  use  of 
pitcoal  fuel;  A.  183  being  an  upright  section,  and /^.  184,  the  ground  pi  a?  Jn 
this  furnace  the  crucibles  are  not  surrounded  with  the  fuei  but^they  recefve  the 
requisite  melting  heat  from  the  flame  proceeding  from  the  grate  upo^n  Xh  it  is 

the  key8tone^6,/5r.  186 ,  between  the  arches  are  spaces  through  which  the  flame  rises 

______      ^^         ^'*oni  the  grate  c;  c?  is  the  fire  door  ; 

['^^0j4  W^M^^M^^^  f'  *  slidmg  tile  or  damper  for  regulat- 
ing or  shutting  off  the  air-draught; 
/,  an  inclined  plane,  for  carrying  off 
the  cinders  that  fall  through  the 
grate,  along  the  draught  tunnel  g,  so 
that  the  air  in  entering  below  may 
not  be  heated  by  them. 

The  crucibles  are  16  inches  deep, 
9i   wide  at  the  mouth,   6i   at  the 

Af  1  ir,/.!,  „n^  ^T^~^"'^^^^        .      1  ^  '  bottom;  with  a  thickness  in  the  sides 

of  1  inch  and  U  below;  they  stand  from  40  to  60  meltings.  The  old  brass,  which 
fills  their  whole  capacity,  is  fii^t  put  in  and  melted  down;  the  crucibles  ^re  now 
taken  out  and  are  charged  w  th  the  half  of  the  zinc  in  pieces  of  froni  1  to  3  cub^ 
inches  m  size,  covered  oyer  with  coal  ashes;  then  one-half  of  the  coppe^charge  is  ^! 
troduced,  again  coal-dust;  and  thus  the  layers  of  zinc  and  copper  are  distributed  S- 
tematel^  with  coal-ashes  betwixt  them,  till  the  whole  charge  gets  finalirfS  Over 
^ht  cmdb J^^ffll  ^/5-':^'°*<^-«"«  '"-"er  is  laid,  to  prevent  olidizemenl  of  the  bVis 
S^f.  1  If  /  ^"^  ?x,*^"'  "^^^  ^"^  P"^'°*^  ^^^^  ^"r°»ce  between  the  11  holes  of  the 
grate  shelf;  and  over  them  two  empty  crucibles  are  laid  to  be  heated  for  the  castW 

UK'k    h'  1  ^"'/"''^  ^*  *^  *  ^^"^«  *^«  ^^^«  i«  ^^"^^Y  to  be  poured  out.     Fifteen  Eng? 
ntroduS  nf  r^'  ^^\7««^°^ed  in  one  operation ;  of  which  six  are  useTat^^e 
mtmduction  of  the  crucibles,  and  four  gradually  afterwards. 
When  sheet  brass  is  to  be  made  the  following  process  is  pursued-— 
An  empty  crucible,  called  a  caner  (giesser),  is  taken  out  of  the  furnace  through  th# 
crown  With  a  pair  of  tongs,  and  is  kept  red  hot  by  placing  it  in  a  hollowSSXInln 
surrounded  with  burning  coals;  into  this  crucible  the  c^ontents  of  four  o?^he  meS 
pots  are  poured ;  the  dross  being  raked  out  with  an  iron  scraper.     As  soon  as  thTS 
ing  pot  IS  emptied.  It  18  immediately  re-charged  in  the  manneV  abov^  describe  A  and  re 
placed  in  the  furnace.     The  surface  of  the  melted  brass  in  the  caX  is  swe^^^^^ 
stump  of  a  broom,  then  stirred  about  with  the  iron  rake  to  brinfup  anv  ^^^^^ 
matterto  the  surface,  which  is  then  skimmed  with  a  little  scraper^tLcrS^^ 
seized  with  the  casting  tongs,  and  emptied  in  the  following  way  •_ 

IftJ  i«r"Ti,''''-^'''''^.f''J  casting  sheet  brass  consists  of  tw5  slaBs  of  granite,  a  a,  /fa*. 
186  186      They  are  5i  feet  long;  3  feet  broad,  1  foot  thick,  and  for  greater  sec^^tv 

ZJnl^  'T  ^^^u'  *  *'  ?>"^"^  ^"^^^  ^*  *^i^^''  a°d  joined  at  the  f^r  cornerwit^h 
mX^^-T"-  ^^%T,^  ^f  «T^  ^-o-ken  block,%,3ifeetlong.2«  broad!ld  U 
foundr?flnnrr^'^'°.1,'^  ""^  T^  'l^  upon  gudgeons,  in  bearing  blocks,  pLced  under  the 
toundry  floor,  dd,  in  the  casting  pit,  e  e.     This  is  lined  with  bricks  •  and  is  65  fplf  Innlf 

laid  whtrf  '  ^?Pa"P«°,''^  '^^^°^  ^^^^  "^"«  of  the  p?t  the  bel  L/^^^^^^^^ 
laid  which  support  the  gudgeons.     The  swing-blocks  arp  in  innK^I  11^  uiockb  are 

broad,  15  inches  thick,  and  are  somewhat  roufded  upon  theh^  WV    ^     ^'    L"""^^^ 

casting  frame  may  slope  a  little  to  the  horizon.    T:ih?s:Vo'ks^t^^^^^^ 


.    it 


!!■ 


242 


BRASS. 


//,  are  mortised,  upon  which  the  underelab  rests  freely,  but  so  as  to  project  about  5  inch- 
es backwards  over  the  block,  to  secure  an  equipoise  in  the  act  of  casting,  g  g  are  bars, 
placed  at  both  of  the  long  sides,  and  one  of  the  ends,  between  the  slabs,  to  determine  the 
thickness  of  the  brass-plate.  Upon  the  other  slab  the  gate  h  is  fastened,  a  sheet  of 
iron  6  inches  broad,  which  has  nearly  the  shape  of  a  parallel  trapezium  (lozenge),  and 
slopes  a  little  towards  the  horizon.  It  serves  for  setting  the  casting  pot  upon  in  the  act 
of  pouring  out,  and  renders  its  emptying  more  convenient.  That  gate  {steinmaul) 
is  coated  with  a  mixture  of  loam  and  hair.  The  upper  slab  is  secured  to  the  under  one 
in  its  slanting  position  by  an  armor  or  binding.  This  consists  of  the  tension  bais  of 
wood,  i  klm,  of  the  iron  bars  n,  (3  to  3i  inches  broad,  IJ  inch  thick,  see  the  top  view, 
fig.  186,)  of  a  rod  with  holes  and  pins  at  its  upper  end,  and  of  the  iron  screw  spindle  o. 
iTie  mode  in  which  these  parts  act  may  be  understood  frorc  inspection  of  the  figure.  In 
order  to  lift  the  upper  slab  from  the  under  one,  which  is  effected  by  turning  it  round  its 
edge,  a  chain  is  employed,  suspending  two  others,  connected  with  the  slab.  The  former 
passes  over  a  puUy,  and  may  be  pulled  up  and  down  by  means  of  a  wheel  and  axle,  or 
with  the  aid  of  a  counterweight.  Upon  each  of  the  two  long  sides  of  the  slab  there 
are  two  iron  rings,  to  which  the  ends  of  the  chains  may  be  hooked.  The  casting  facea 
of  the  slab  must  be  coated  with  a  layer  of  finely  ground  loam ;  the  thinner  the  better. 

When  calamine  is  employed,  i  cwt.  of  copper,  |  cwt.  of  calamine,  and  \:  the  volume 
of  both  of  charcoal  mixed,  are  put  into  seven  crucibles,  and  exposed  to  heat  during 
II  or  12  hours;  the  product  being  from  70  to  72  lbs.  of  brass. 

Brass-Plate  Rolling. — At  Hegermiihl  there  are  two  re-heating  or  annealing  fur- 
naces, one  larger,  18  feet  long,  and  another  smaller,  8  J ;  the  hot  chamber  is  separated 
from  the  fire  place  by  iron  beams,  in  such  a  way  that  the  brass  castings  are  played 
upon  by  the  flames  on  both  their  sides.  After  each  passage  through  the  laminating 
press  (rolls)  they  are  heated  anew,  then  cooled  and  laminated  afresh,  till  they  have 
reached  the  proper  length.     The  plates  are  besmeared  with  grease  before  rolling. 


wrMr^>:'^m'. 


"Fxg.  187  shows  the  ground  plan  of  the  furnace  and  its  railway  ;^^.  188  the  cross  see- 
Uon;  2ctAjig.  189  the  section  lengthwise ;  a  a,  the  iron  way  bars  or  rails  upon  the  floor 
of  the  foundry,  for  enabling  the  wheels  of  the  wagon-frame  to  move  readily  back- 
wards and  forwards ;  h  b,  the  two  grates ;  e  c,  the  ash  pits ;  d  d,  the  fire  beams ;  e  e  e, 
vents  in  the  roof  of  the  hot  chamber/;  g  g,  two  plates  for  shutting  the  hot  chamber; 
/*,  the  flue ;  t,  the  chimney.  After  the  rolling,  the  sheets  covered  with  a  black  oxide 
of  copper,  are  plunged  into  a  mother  water  of  the  alum  works  for  a  few  minutes,  then 
washed  in  clean  water,  and  lasiiy,  smeared  with  oil,  and  scraped  with  a  blunt  knife. 

In  rough  brass  and  brass  wares,  no  less  than  16,240  cwts.  were  manufactured  in 
ihe  Prussian  States  in  the  year  1832. 

For  musical  purposes,  the  brass  wire  made  in  Berlin,  has  acquired  great  and  merit- 
ed celebrity ;  but  that  of  Bii-mingham  is  now  preferred  even  by  foreigners. 

Brass  Color,  for  staining  glass,  is  prepared  by  exposing  for  several  days  thin  plates 
of  brass  upon  tiles  in  the  leer  or  annealing  arch  of  the  glass-house,  till  it  be  oxidized 


BRASS. 


24S 

to  be 

state ; 


mto  a  black  powder,  aggregated  in  lumps.  This  being  pulverized  and  sifted,  is 
again  well  calcined  for  several  days  more,  till  no  particles  remain  in  the  metallic  state- 
when  it  will  form  a  fine  powder  of  a  russet  brown  colour.  A  third  calcination  must  now 
be  given  with  a  carefully  regulated  heat ;  its  quality  being  tested  from  time  to  time  bv 
fusion  with  some  glass  If  it  makes  the  glass  swell,  and  intumesce,  it  is  properly  pre- 
pared ;  if  not^  It  must  be  still  farther  calcined.  Such  a  powder  communrcat^  to  glass 
greens  of  various  tints,  passing  into  turquoise 

When  thin  narrow  strips  of  brass  are  stratified  with  sulphur  in  a  crucible,  and  calcined 
^nL™i'd  Ln  T?'"'*"''  ^"^^i''  ^"^  ™*y  ^^  reduced  to  powder.  This  being  sifted 
Z  l^fAT  Kl  'f '"  *  ^l^.^^b«^*J«ry  furnace  for  ten  or  twelve  days  become!  fit  for 
use,  and  is  capable  of  imparting  a  chalcedony,  red  or  yellow  tinge  to  glass  by  fusion, 
according  to  the  mode  and  proportion  of  using  it  5         g  ««  uj,  iusiuii. 

The  glass-maker's  red  colour  may  be  prepared  by  exposing  small  plates  of  brass  to  a 
moderate  heat  m  a  reverberatory  furnace,  till  the/  are^thoroughly  calcined  when  the 
imme'^:t\  u^"''  P"^"^^"^^'^^'   ^"^  ^^^^^  ^  red  colour.^  It  i«  then  rial;  for 

Brass  COLOUR,  as  employed  bj  the  colourmen  to  imitate  braas,  is  of  two  tints,  the 
red  or  bronze,  and  the  yellow  ifke  gilt  brass.  Copper  filings  mixed  with  red  ochr^ 
or  bole  constitute  the  former;  a  powdered  brass  imported  ffom  GeLli v  is  Ld  for 
the  latter  Both  must  be  worked  up  with  varnish  after  being  dried  w'ui  heat  and  then 
spread  with  a  flat  camel-hair  brush  evenly  upon  the  surfacf  of  tL  oSecl  Hht  b^^^ 
varnish  is  composed  o  20  ounces  of  spirits  of  wine,  2  ounces  of  shellac,  and  2  ounces^f 
sandarach,  properly  dissolved.  See  Varnish.)  Only  so  much  of  the  brai  Dowdcr 
P™T  ""'^  ''  "  ''""  "  "  "^"''^  '^'  immediate  lie.'    (sTe  CxS 

Brass  Foi^  Dutch  leaf,  called  Knitter  or  Rauschgold  in  Germany,  is  made  from 
30^  or4^\tok.^''''  ^«^V"t--^«^-  hammer  work^ed  by  water  po^er  which  g[^S 
3M  or  400  strokes  per  minnte;  from  40  to  80  leaves  being  laid  over  each  other  By 
this  treatment  it  acquires  its  characteristic  solidity  and  lustre.  See  above  the  proem 
for  converting  the  copper  superficially  into  brass  iy  the  fumes  of  zinc        '        ^ 

Brass,  \ellow.  The  following  ta1>le  exhibit*  the  composition  of  several  varieties 
of  this  species   of  brass.     No.  1.  is  a  cast  brass  of  uncertain  origin-  2   the  bra^ 

briT^^'nA-  '•    '^'  1^-""'  ^^"^^  "^  ^^^^^r&  ^«^r  Aix-la-ChapelleTi.  and  5    th^ 
brass  for  gildmg,  according  to  D'Arcet;    6.  the  sheet  brass  of  Ron/illy ;    7.  EngUsh 

n^r^bbluS/ood  0I Btl^^  'T  -^^^^   ''  ^--  --  ^'  Keustadt-Ebe^^ant^Z 


1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

Copper 
Zinc 
Lead 
Tm 

61-6 

35-3 

2-9 

0-2 

646 

33-7 

1-4 

0-2 

64-8 

32-8 

2-0 

0-4 

1000 

63-70 

33  55 

0-25 

2-50 

64  45 

32-44 

2-86 

0-25 

701 
29-9 

70  29 

29-26 

0-28 

017 

71-69 
27-63 

0-85' 

7016 

27-45 

0-20 

0-79 

1000 

99-9 

100-00 

lOOf.O 

"                   • 

10000 

UiO-37 

98  60 

Tlie  mean  proportion  of  the  metals  in  yellow  brass  is  30  zinc  to  70  copper 
/cwiiaA,  or  Red  Brass,  in  the  cast  state,  is  an  alloy  of  copper  and  zinc  containinir 
not  more  than  20  per  cent  of  the  latter  constituent     The  following  v^Srarf 
hand'iS't'^'TV  2,  3.  tombak  for  making  gilt  articles;  4.  French  tomLk  for   word 
handles,  Ac  ;  4.  tombak  of  the  Okar,  near  Goslar,  in  the  Hartz;  5.  yellow  tomblk  of 
Paris  for  gilt  ornaments;  6   tombak  for  the  same  purpose  from  'a  fac^torvTn  Hanover 
8.  chrysochalk;  9.  red  tombak  from  Paris ;  10.  red  timbak  of  ViennT  ' 


Copper 
Zinc   - 
Lead  - 
Tin     -        . 

1. 

2. 

3, 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

820 

180 

15 

30 

82 

18 

3 

1 

823 
17-5 

■    0.2" 

80 
17 

3 

85 
15 

trace. 

85-3 
14-7 

86 
14 

90-0 
7-9 
1-6 

92 

8 

97-8 
22 

104-5 

104 

lOD-O 

100 

100 

100  0    ' 

100 

99-5 

100        100-0 

See  War!^.'.''^  \  P^^*«^^PP^^  *°^  \  y.eljow  brass: 
Mannheim  gold  (semilor),  28  copper,  12  yeHow  brass,  3  tin. 
«n^c"and  2I"  "  '"  "'^'  ''  ""^  '^^^^  «^  ^^  ^^^  ^^  (j^^o^\  ^  Parta 

The  specific  gravity  of  brass  is  greater  than  the  mean  density  of  its  constituent 


1 


i 


244 


BRAZIL-WOOD. 


BRAZIL-WOOD. 


245 


I 


i     r 


!   ,i; 


\  i 


Tarving  from  7  "82  to  8  "7  3,  according  to  the  proportion  of  zinc  to  copper.  Sheet  brass 
vanes  from  8*62  to  8*62 ;  brass  wire  from  8'49  to  8'73.  Brass  heated  and  quickly 
cooled  becomes  somewhat  less  dense.  The  specific  gravity  of  sheet  tombak  (81*25 
coppes  +  18"75  zinc)  is  $"188;  of  tombak  wire  (87 "6  copper  +  12'5  zinc)  has  been 
found  so  great  as  9  "00. 

Brass,  Malleable.  It  is  known  that  common  brass  containing  from  27*4  to  3r8  per 
cent  of  zinc,  and  from  71-9  to  65'8  per  cent  of  copper,  is  not  malleable  while  hot, 
but  that  articles  of  it  must  be  made  by  casting.  As  it  would  be  of  great  advantage  in 
many  branches  of  industry  to  have  an  alloy  of  this  kind  that  could  be  worked  while 
hot,  like  malleable  iron,  the  information  that  such  an  alloy  exists  must  be  welcome  to 
artists. 

By  melting  together  33  parts  of  copper,  and  25  parts  of  zinc,  there  was  a  loss  of  three 
parts ;  thus  making  60  per  cent  copper,  and  40  per  cent  zinc.  It  differs  from  the 
English  specimens  by  containing  a  larger  proportion  of  zinc,  and  possesses,  according  to 
M.  Machts,  the  precious  property  of  malleability  in  a  higher  degree  than  the  English 
specimens. 

A  piece  of  "yellow  metal,"  similar  in  colour  to  this  alloy,  was  found,  on  analysis,  to 
contain  60*16  copper,  and  39*7 1  zinc,  which  is  the  composition  of  malleable  brass.  It 
also  showed  great  density  or  solidity. 

An  alloy  was  prepared  by  melting  together  60  parts  copper  and  40  parts  zinc,  which 
had  the  following  properties: — The  colour  was  between  that  of  brass  and  tombak,  it 
had  a  strong  metallic  lustre,  a  fine,  close  grained  fracture,  and  great  solidity  (density). 
Its  specific  gravity  at  the  temperature  of  10°  Cent,  was  8*44;  by  calculation  it  ou^hi 
only  to  have  been  8"08 ;  thus  showing  that  in  the  formation  of  the  alloy  a  condensation 
must  have  taken  place.  Calculation  shows  that  the  alloy  may  be  considered  as  a  de- 
terminate chemical  combination,  for  the  results  of  the  analysis  veiy  nearly  accord  with 
the  assumption  that  it  may  be  considered  as  composed  of  3  atoms  by  weight  of  copper, 
and  2  atoms  by  weight  of  zinc  (3  Cu  +  2  Zn).  The  hardness  of  the  alloy  is  the  same 
as  that  of  fluor  spar ;  it  can  be  scratched  by  apatite  (glass),  consequently  its  hardness 
IB  =4.  The  alloy  is  harder  than  copper,  very  tough,  and  is,  in  a  properly  managed  fire, 
malleable ;  so  much  so  that  a  key  was  forged  out  of  a  cast  rod. 

These  important  properties  of  this  alloy  warrant  an  expectation  of  its  application  to 
many  purposes  in  the  arts,  and  it  would  appear  that  they  depend  on  its  definite  chemical 
proportions.  Agreeably  to  the  directions  of  M.  Feyerabind,  care  must  be  taken  in 
melting  together  the  metals,  not  to  permit  too  great  a  loss  of  zinc  to  take  place,  lest  the 
proportions  between  the  metals  should  be  altered,  which  might  not  be  without  effect  on 
the  important  properties  of  the  alloy.  With  this  view,  it  might  be  advantageous  in 
practice,  in  place  of  zinc,  to  add,  in  melting,  a  proportionate  mixture  of  brass  to  the 
proper  proportions  of  copper.  An  alloy  prepared  in  this  way  gave,  on  analysis,  61*44 
copper,  and  38*15  zinc.  It  is  very  probable  that  malleable  brass  will  hereafter,  in  many 
cases,  be  made  use  of  instead  of  the  higher  priced  copper. 

BRAZING.  {Eraser,  Fr. ;  Messing-lothung,  Germ.)  The  soldering  together  of 
edges  of  iron,  copper,  brass,  Ac,  with  an  alloy  consisting  of  brass  and  zinc,  sometimes 
with  a  little  tin  or  sUver.  The  surfaces  to  be  thus  united  must  be  filed  perfectly 
bright,  and  not  be  soiled  with  the  fingers  or  in  any  other  way.  The  granular  or  nearly 
pulverulent  alloy  is  usually  wetted  with  a  paste  of  ground  borax  and  water,  applied  in 
this  state,  dried,  and  then  exposed  carefully  to  bright  ignition  at  a  clear  forge  fire. 
Some  workmen  enclose  the  part  to  be  soldered  in  a  clay  lute,  but  others  prefer  leaving 
it  uncovered,  that  they  may  see  when  the  solder  has  flowed  freely,  and  entered  into  all 
the  seams. 

BRAZIL-WOOD.  (Boisde  Femamhoucy  Fr. ;  Brasilienhohj  Germ.)  This  dye-wood 
derives  its  name  from  the  part  of  America  whence  it  was  first  imported.  It  has  also 
the  names  Femambuca,  wood  of  Saint  Martha,  and  of  Sapan,  according  to  the  places 
which  produce  it.  Linnaeus  distinguishes  the  tree  which  furnishes  the  Brazil-wood 
by  the  name  of  Ccesalpinia  crista.  It  commonly  grows  in  dry  places  among  rocks.  Its 
trunk  is  very  large,  crooked,  and  fuU  of  knots.  It  is  very  hard,  susceptible  of  a  fine 
polish,  and  sinks  in  water.  It  is  pale  when  newly  cleft,  but  becomes  red  on  exposure  to 
the  air. 

It  has  different  shades  of  red  and  orange.  Its  goodness  is  determined  particularly  by 
its  density.  When  chewed,,  a  saccharine  taste  is  perceived.  It  may  be  distinguished 
from  red  saunders  wood,  as  the  latter  does  not  yield  its  color  to  water. 

Boiling  water  extracts  the  whole  coloring  matter  of  Brazil-wood.  If  the  ebullition  be 
long  enough  continued,  it  assumes  a  fine  red  color.  The  residuum  appears  black.  In 
this  case,  an  alkali  may  still  extract  much  coloring  matter.  The  solution  in  alcohol  or 
ammonia  is  stiU  deeper  than  the  preceding. 

The  decoction  of  Brazil-wood,  called  juice  of  Brazil,  is  observed  to  be  less  fit  for 
dyeing  when  recent,  than  when  old  or  eren  fermented.    By  age,  it  takes  a  yellowish- 


red  color.  For  making  this  decoction,  Hellot  recommends  to  use  the  hardest  water;  but 
it  should  be  remarked,  that  this  water  deepens  the  color  in  proportion  to  the  earthy  salt! 
which  it  contains.  After  boiling  this  wood  reduced  to  chips,  or,  what  is  preferable,  to 
powder,  for  three  hours,  this  first  decoction  is  poured  into  a  cask.  Fresh  water  is  poured 
on  the  wood,  which  is  then  made  to  boU  for  three  hours,  and  mixed  with  the  former. 
When  Brazd-wood  is  employed  in  a  dyeing  bath,  it  is  proper  to  enclose  it  in  a  thin  linea 
bag,  as  well  as  all  the  dye-woods  in  general. 

Wool  immersed  in  the  juice  of  Brazil  takes  but  a  feeble  tint,  which  is  speedfly  de- 
stroyed.   It  must  receive  some  preparations. 

.  '^^f  7^^  *^  J^  ^®  ^^^^  ^^  *  solution  of  alum,  to  which  a  fourth  or  even  less  of  tartar 
IS  added,  for  a  larger  proportion  of  tartar  would  make  the  color  yellowish.  The  wool  is 
kept  impregnated  with  it  for  at  least  eight  days,  in  a  cool  place.    After  this,  it  is  dyed  in 

J  2  ,  ^"u  ^  ^i?.*  ^Y^^^  ^'''^''''^'  ^"^  ^^^  ^""st  coloring  particles  that  are  deposited, 
?v  u  *  jess  beautiful  color;  hence  it  is  proper  to  pass  a  coarser  stuff  previously  through 
the  bath.     In  this  manner  a  lively  red  is  procured,  which  resists  pretty  well  the  action 

Brazil-wood  is  made  use  of  for  dyeing  sUk  what  is  called  false  crimson,  to  distinguish 
It  from  the  crimson  made  by  means  of  cochineal,  which  is  much  more  permanent. 

The  sUk  should  be  boded  at  the  rate  of  20  parts  of  soap  per  cent.,  and  then  alumed. 
The  alummg  need  not  be  so  strong  as  for  the  fine  crimson.  The  silk  is  refreshed  at  the 
T!!''  ^"iP^ssed  through  a  bath  more  or  less  charged  with  Brazd  juice,  according  to  the 
shade  to  be  given.  When  ^ater  free  from  earthy  salts  is  employed,  the  color  is  too  red 
to  imitate  crimson ;  this  quality  is  given  it  by  passing  the  silk  through  a  slight  alkaline 
solution  or  by  adding  a  little  alkali  to  the  bath.  It  might,  indeed,  be  wash  A  in  a  hard 
water  till  it  had  taken  the  desired  shade. 

To  make  deeper  false  crimsons  of  a  dark  red,  juice  of  logwood  is  put  into  the  Brazil 
bath  after  the  silk  has  been  impregnated  with  it.  A  little  alkali  may  be  added,  according 
to  the  shade  that  is  wanted.  ® 

To  imitate  poppy  or  flame  color,  an  annotto  ground  is  given  to  the  sQk,  deeper  even 
than  when  it  is  dyed  with  carthamus.    It  is  washed,  alumed,  and  dyed  with  juice  of  Bra- 
zil, to  which  a  hltle  soap  water  is  usually  added. 
of'aciV"^''"^^  particles  of  BrazU-wood  are  easUy  affected,  and  made  yellow  by  the  acUon 

They  thus  become  permanent  colors.  But  what  distinguishes  them  from  madder  and 
Kermes,  and  approximates  them  to  cochineal,  is  their  reappearing  in  their  natural  color. 
When  they  are  thrown  down  in  a  stale  of  combination  with  alumina,  or  with  oxyde  of  tin. 
These  two  combinations  seem  to  be  the  fittest  for  rendering  them  durable.  It  is  requisite, 
therefore  to  mquire  what  circumstances  are  best  calculated  to  promote  the  formation  of 
-nese  combinations,  according  to  the  nature  of  tie  stuff. 

The  astringent  principle,  likewise,  seems  to  contribute  to  the  permanence  of  the  color- 
shide*  BrazU-wood;  but  it  deepens  its  hue,  and  can  only  be  employed  for  light 

The  coloring  particles  of  Brazil-wood  are  very  sensible  to  the  action  of  alkalis 
Which  give  them  a  purple  hue;  and  there  are  several  processes  in  which  the  alkalis, 
either  fixed  or  volatde,  are  used  for  forming  violets  and  purples.  But  the  colors  ob- 
tained by  these  methods,  which  may  be  easUy  varied  according  to  the  purpose,  arc 
perishable,  and  possess  but  a  transient  bloom.  The  alkalis  appear  not  to  injure 
the  colors  derived  from  madder,  but  they  accelerate  the  destruction  of  most  other 
colors. 

In  England  and  Holland  the  dye-woods  are  reduced  to  powder  by  means  of  mills  erected 
lor  the  purpose. 

^J5^  ^'''^^^  ^'J^'^i^'^''^^'  *^m"^'^  ^'^'^y  '*^'  '^  Siven  to  cotton  by  Nicaragua,  or  peach- 
wood,  a  cheap  kind  of  Brazil-wood.  i^«»-u- 

»J^^^  u^"""",  ^^'"^  scoured  and  bleached,  is  boiled  with  sumach.  It  is  then  impreffna- 
IkctiTi  •  *  solution  of  tin  (at  5*  Baurae,  according  to  VilaUs).  It  should  now  be  washed 
!  n„  /.J."  *  ^^t^  ^"i^  "*  M^^^  dyeing  wood,  and,  lastly,  worked  in  a  somewhat  stale  infu- 
sion of  he  peach  or  Brazil  wood.  When  the  temperature  of  this  is  lukewarm,  the  dye  is 
wm  to  take  better.  Sometimes  two  successive  immersions  m  the  bath  are  given.  It  is 
now  wrung  out,  aired,  washed  in  water,  and  dried. 
M.  Vitalis  says,  that  his  solution  of  tin  is  prepared  with  two  ounces  of  tin  and  a  pound 

^L*''"^'"Too?^^  "^'^^  ^'^'^  P*''*^  **^  "*^*<^  ^<^i^  a^  24«»  Baume,  and  three  parts  of  muri- 
niic  acid  at  22".  »  i-  • 

For  a  rose  color,  the  cotton  is  alumed  as  usual,  and  washed  from  the  alum.  It  then 
SltoV-^  tin  mordant,  and  is  again  washed.  It  is  now  turned  through  the  dye-bath,  an 
ope-ation  which  is  repeated  if  necessary.  j        *^  «■ 

For  purple,  a  httle  alum  is  added  to  the  Brazil  bath. 

1.  For  amaranth,  the  cotton  is  strongly  galled,  dried,  and  washed. 


UlS 


BREAD. 


BREAD. 


247 


I' 


|i 


i 


2.  Ii  is  passed  through  the  black  cask  (tonne  au  noir,)  see  Black  Dye,  till  it  has  lake* 
ft  strong  gray  shade. 

3.  It  receives  a  bath  of  lime-crater. 

4.  Mordant  of  tin. 

6.  Dyeing  in  the  Brazil-wood  b«lh. 

6.  The  two  last  cpei-ations  are  repeated. 

Dingier  has  endeavored  to  separate  the  coloring  matter  of  the  different  sorts  of  Brazil, 
wood,  so  as  to  obtain  the  same  tint  from  the  coarser  as  from  the  best  Pernambuco.  His 
process  consists  in  treating  the  wood  with  hot  water  or  steam,  in  concentrating  the  de- 
coction so  as  to  obtain  14  or  15  pounds  of  it  from  4  pounds  of  wood,  allowing  it  to  cool, 
and  pouring  into  it  two  pounds  of  skim  milk ;  agitating,  then  boiling  for  a  few  minutes, 
and  filtering.  The  dun  coloring  matters  are  precipitated  by  the  coagulation  of  the 
caseous  substance.  For  dyeing,  the  decoctions  must  be  diluted  with  water ;  for  printing 
they  must  be  concentrated,  so  that  4  pounds  of  wood  shall  furnish  only  5  or  6  pounds  of 
decoction,  and  the  liquor  may  be  thickened  in  the  ordinary  way.  These  decoctions  may 
be  employed  immediately,  as  by  this  treatment  they  have  acquired  the  same  property  as 
they  otherwise  could  get  only  by  being  long  kept.  A  slight  fermentation  is  said  to  im- 
prove the  color  of  these  decoctions;  some  ground  woot.  's  put  into  the  decoction  to  favor 
this  process. 

As  gelatine  produces  no  precipitate  with  these  decoctions,  they  consequently  contain 
no  tannin.  Gall-nuts,  however,  sumach,  the  bark  of  birch  or  alder,  render  the  color  of 
Brazil-wood  more  durable,  upon  alumed  linen  and  cotton  goods,  but  the  shade  is  a  little 
darker. 

In  dyeing  wool  with  Pernambuco,  the  temperature  of  the  bath  should  never  be  above 
150°  Fahr.,  since  higher  heats  impair  the  color. 

According  to  Dingier  and  Kurrer,  bright  and  fast  scarlet  reds  may  be  obtained  upon 
wool,  by  preparing  a  decoction  of  50  pounds  of  Brazil-wood  in  three  successive  boils, 
and  setting  the  decoction  aside  for  3  or  4  weeks  in  a  cool  place ;  100  pounds  of  the  w«ioi 
are  then  alumed  in  a  bath  of  22  pounds  of  alum  and  1 1  pounds  of  tartar,  and  aAerwards 
rinsed  in  cold  water.  Meanwhile  we  fill  two  thirds  with  water,  a  copper  containing  30 
pails,  and  heated  to  the  temperature  of  150°  or  160»  F.  We  pour  in  3  pailfuls  of  the  de- 
coction, heat  to  the  same  point  again,  and  introduce  30  pounds  of  wool,  which  does  not 
take  a  scarlet,  but  rather  a  crimson  tint.  This  being  removed,  2  pails  of  decoction  are 
put  in,  and  30  pounds  of  wool,  which  becomes  scarlet,  but  not  so  fine  as  at  the  third  dip. 
If  the  dyer  strengthens  the  color  a  little  at  the  first  dip,  a  little  more  at  the  second,  and 
adds  at  the  third  and  fourth  the  quantity  of  decoction  merely  necessary,  he  will  obtain  a 
uniform  scarlet  tint.  With  50  pounds  of  Pernambuco  1000  pounds  of  wool  may  be  dyed 
scarlet  in  this  way,  and  with  the  deposites  another  100  may  be  dyed  of  a  tile  color.  An 
addition  of  weld  renders  the  color  faster  but  less  brilliant. 

Earkutsch  says  the  dye  may  be  improved  by  adding  some  ox-gall  to  the  bath. 

In  dyeing  cotton  the  tannin  and  gallic  acid  are  two  necessary  mordants,  and  the  color 
is  particularly  bright  and  durable,  when  the  cloth  has  been  prepared  with  the  oDy  process 
of  Turkey  red. 

It  is  said  that  stale  urine  heightens  the  color  of  the  Brazil  dye  when  the  ground  wood 
is  moistened  with  it. 

The  quantity  of  Brazil  or  Nicaragua  wood  imported  into  the  United  Kingdom  in  1835, 
was  6,242  tons,  whereof  1,811  were  exported;  of  BraziUetto  230  tons.  The  duty  upon 
the  first  article  is  5*.  per  ton. 

BREAD  (Painy  Fr. ;  Brod,  Germ.)  is  the  spongy  mass  produced  by  baking  the 
leavened  or  fermented  dough  of  wheal  or  rye  flour,  at  a  proper  heat.  It  is  the  principal 
food  of  highly  civilized  nations.  The  skilful  preparation  of  this  indispensable  article  con- 
stitutes the  art  of  the  Baker.  Dough  baked  without  being  fermented  constitutes  cakes 
or  biscuits ;  but  not  bread  strictly  speaking. 

Pliny  informs  us,  that  barley  was  the  only  species  of  com  at  first  used  for  food ;  and 
even  ailer  the  method  of  reducing  it  to  flour  had  been  discovered,  it  was  long  before 
mankind  learned  the  art  of  converting  it  into  cakes. 

Ovens  were  first  invented  in  the  East.  Their  construction  was  understood  by  the 
Jews,  the  Greeks,  and  the  Asiatics,  among  whom  baking  was  practised  as  a  distinct  pro- 
fession. In  this  art,  the  Cappadaiians,  Lydians,  and  Phoenicians,  are  said  to  have  par- 
ticularly excelled.  It  was  not  till  about  580  years  after  the  foundation  of  Rome,  that 
these  artisans  passed  into  Europe.  The  Roman  armies,  on  their  return  from  Macedonia, 
brought  Grecian  bakers  with  them  into  Italy.  As  these  bakers  had  handmills  beside 
their  ovens,  they  still  continued  to  be  called  pistores,  from  the  ancient  practice  of  bruis- 
ing the  com  in  a  mortar;  and  their  bakehouses  were  denominated  pistoria.  In  the  time 
of  Augustus  there  were  no  fewer  than  329  public  bakehouses  in  Rome;  almost  the  whole 
of  which  were  in  the  hands  of  Greeks,  who  long  continued  the  only  persons  in  that  city 
mequainted  with  the  art  of  baking  good  bread. 

12 


In  nothing,  perhaps,  is  the  wise  and  cautious  policy  of  the  Roman  government  more 
remarkably  displayed,  than  in  the  regulations  which  it  imposed  on  the  bakers  withia 
the  city.  To  the  foreign  bakers  who  came  to  Rome  with  the  army  from  Macedonia,  a 
number  of  frcedmen  were  associated,  forming  together  an  incorporation  from  which 
neither  they  nor  their  children  could  separate,  and  of  which  even  those  who  married  the 
daughters  of  bakers  were  obliged  to  become  members.  To  this  incorporation  were  itt- 
trusted  all  the  mills,  utensils,  slaves,  animals,  every  thing,  in  short,  which  belonged  to 
the  former  bakehouses.  In  addition  to  these,  they  received  considerable  portions  of  land ; 
ftnd  nothing  was  withheld,  which  could  assist  them  in  pursuing,  to  the  best  advantage, 
their  highly  prized  labors  and  trade.  The  practice  of  condemning  criminals  and  slaves, 
for  petty  offences,  to  work  m  the  bakehouse,  was  still  continued ;  and  even  the  judges  of 
Africa  were  bound  to  send  thither,  every  five  years,  such  persons  as  had  incurred  that 
kind  of  chastisement.  The  bakehouses  were  distributed  throughout  the  fourteen  divisions 
of  the  city,  and  no  baker  could  pass  from  one  into  another  without  special  permission. 
The  public  granaries  were  committed  to  their  care;  they  paid  nothing  for  the  corn  em- 
ployed m  baking  bread  that  was  to  be  given  in  largess  to  the  citizens;  and  the  price  of 
the  rest  was  regulated  by  the  magistrates.  No  com  was  given  out  of  these  granaries  ex- 
cept for  the  bakehouses,  and  for  the  private  use  of  the  prince.  The  bakers  had  besides 
private  granaries,  m  which  they  deposited  the  grain,  which  they  had  taken  from  the  pub- 
be  granaries  for  immediate  use  ;  and  if  any  of  them  happened  to  be  convicted  of  having 
diverted  any  portion  of  the  grain  to  another  purpose,  he  was  condemned  to  a  ruinous  fine 
of  five  hundred  pounds  weight  of  gold. 

Most  of  these  regulations  were  soon  introduced  among  the  Gauls ;  but  it  was  long  be- 
fore they  found  their  way  into  the  more  northern  countries  of  Europe.  Borrichius  informs 
us  that  in  Sweden  and  Norway,  the  only  bread  known,  so  late  as  the  middle  of  the  16th 
century,  was  unleavened  cakes  kneaded  by  the  women.  At  what  period  in  our  own  his- 
tory the  art  of  baking  became  a  separate  profession,  we  have  not  been  able  to  ascertain ; 
but  this  profession  is  now  common  to  all  the  countries  in  Europe,  and  the  process  of 
baking  is  also  nearly  the  same. 

The  French,  who  particularly  excel  in  the  art  of  bakine,  have  a  great  many  different 
kinds  of  bread.  Their  pain  bis,  or  brown  bread,  is  the  coarsest  kind  of  all,  and  is  made 
of  coarse  groats  mixed  with  a  portion  of  white  flour.  The  pain  bis  blanc,  is  a  kind  of 
bread  between  white  and  brown,  made  of  white  flour  and  fine  groats.  The  pain  blanc, 
or  white  bread,  is  made  of  white  flour,  shaken  through  a  sieve  after  the  finest  flour  has 
been  separated.  The  pain  mollet,  or  soft  bread,  is  made  of  the  purest  flour  without  any 
admixture.  The  pain  chaland,  or  customers'  bread,  is  a  very  white  kind  of  bread,  made 
of  pounded  paste.  Pain  chapele,  is  a  small  kind  of  bread,  with  a  well-beaten  and  very 
light  paste,  seasoned  with  butter  or  milk.  This  name  is  also  given  to  a  small  bread,  from 
which  the  thickest  crust  has  been  removed  by  a  knife.  Pain  comu,  is  a  name  given  by 
the  French  bakers  to  a  kind  of  bread  made  with  four  corners,  and  sometimes  more.  Of 
all  the  kinds  of  small  bread,  this  has  the  strongest  and  firmest  paste.  Pain  a  la  reine, 
queen's  hretid,  pain  a  la  Sigovie,pain  chapele,  and  pain  cornu,  are  all  small  kinds  of  bread, 
differing  only  in  the  lightness  or  thickness  of  the  paste.  Pain  gruau  is  a  small  very 
white  bread  made  now  in  Paris,  from  the  flour  separated  after  a  slight  grinding  from  the 
best  wheat.     Such  flour  is  in  hard  granular  particles. 

In  this  country  we  have  fewer  varieties  of  bread,  and  these  differ  chiefly  in  their  de- 
grees of  purity.  Our  white  or  fine  bread  is  made  of  the  purest  flour ;  our  wheatea 
bread,  of  flour  with  a  mixture  of  the  finest  bran ;  and  our  household  bread,  of  the  whole 
substance  of  the  grain  without  the  separation  either  of  the  fine  flour  or  coarse  bran.  We 
have  also  symnel  bread,  manchet  or  roll  bread,  and  French  bread,  which  are  all  made  of 
the  purest  flour  from  the  finest  wheat;  the  roll  bread  being  improved  by  the  addition  of 
inilk,  and  the  French  bread  by  the  addition  of  eggs  and  butter.  To  these  may  be  added 
gingerbread,  a  cake  made  of  flour,  with  almonds,  liquorice,  aniseed,  rose-water,  and  sugar 
or  treacle;  and  mastlin  bread,  made  of  wheat  and  rye,  or  sometimes  of  wheat  and  barley. 
We  have  various  kinds  of  small  bread,  having  various  names,  according  to  their  various 
forms.  They  are,  in  general,  extremely  light,  and  are  sweetened  with  sugar,  currants, 
and  other  palatable  ingredients.  In  Scotland  there  is  a  cake  called  short  bread,  made 
from  a  pretty  thick  dough,  enriched  with  butter,  sweetened  with  sugar,  and  seasoned  with 
orange  peel,  or  other  kinds  of  spices. 

The  process  of  making  bread  is  nearly  the  same  in  all  the  countries  of  modern  Europe ; 
though  the  materials  of  which  it  is  composed  vary  with  the  farinaceous  productions  of 
different  climates  and  soils.  The  flour  of  wheat  is  most  generally  employed  for  this  pur- 
pose, wherever  that  vegetable  can  be  reared.  This  flour  is  composed  of  a  small  portion 
of  mucilaginous  saccharine  matter,  soluble  in  cold  water,  from  which  it  may  be  separated 
by  evaporation;  of  a  great  quantity  of  starch,  which  is  scarcely  soluble  in  cold  water,  but 
capable  of  combining  with  that  fluid  by  means  of  heat ;  and  an  adhesive  gray  substance 
called  gluten,  insoluble  in  water,  ardent  spirit,  oil,  or  ether,  and  resembling  an  animal 


Bl    ;1* 


♦if 


I      ;  ii 


f  ,1 


I 

1 

1 

i   ■ 


S48 


BREAD. 


substance  in  many  of  its  properties.  Flour  kneaded  with  water,  forms  a  tough  and  rather 
indigestible  paste  containing  all  the  constituent  parts  which  we  have  enumerated.  Heat 
produces  a  considerable  change  on  the  glutinous  part  of  this  compound,  and  renders  it 
more  easy  of  mastication  and  digestion.  Still,  however,  it  continues  heavy  and  tough, 
compared  with  bread  which  is  raised  by  leaven  or  yeast.  Leaven  is  nothing  more  than  a 
piece  of  dough  kept  in  a  warm  place  till  it  undergoes  a  process  of  fermentation ;  swelling, 
becoming  spongy,  or  fuU  of  air  bubbles,  at  length  disengaging  an  acidulo-spiriluous  va- 
por and  contracting  a  sour  taste.  When  this  leaven  is  mingled  in  proper  proportions 
with  fresh-made  dough,  it  makes  it  rise  more  readily  and  effectually  than  it  would  do 
alone,  and  gives  it  at  the  same  time  a  greater  degree  of  firmness.  Upon  the  quality  of 
the  leaven  employed,  the  quality  of  the  bread  materially  depends. 

The  principal  improvement  which  has  been  made  on  bread  in  mjuem  times,  is  the 
substitution  of  yeast  or  barm  in  place  of  common  leaven.  This  yeast  is  the  viscid  froth 
that  rises  to  the  surface  of  beer,  in  the  first  stage  of  its  fermentation.  When  mixed  with 
the  dough,  it  makes  it  rise  much  more  speedily  and  effectually  than  ordinary'  leaven, 
and  the  bread  is  of  course  much  lighter,  and  freer  from  that  sour  and  disagreeable  taste 
which  may  often  be  perceived  in  bread  raised  with  leaven,  either  because  too  much  is 
mingled  with  the  paste,  or  because  ii  has  been  allowed  to  advance  too  far  in  he  process 

of  fermentation.  .  „    «  ,  ,      ,  .      i    • 

Bread  properly  raised  and  baked  differs  materially  from  unleavened  cakes,  not  only  in 
being  less  compact  and  heavy,  and  more  agreeable  to  the  taste,  but  in  losing  its  tena- 
cious and  glutinous  qualities,  and  thus  becoming  more  salutary  and  digestible. 

We  possess  several  analyses  of  wheat  flour.  Ordinary  wheat  (triticum  hybemum 
mixed  with  triticum  turgidum)  contains,  according  to  the  analyses  made  by  Vauquelin 
of  several  species  of  wheat  flour,  the  followmg  substances  : — 


Species  of  Wheat. 


French  wheat  flour  -    - 

Hard  wheat  of  Odessa 

flour-    -    -    -    -    - 

Soft  wheat  of   Odessa 
flour-    -    -    -    -    - 

Same  sort  of  flour    -    - 

Same  sort  of  flour   -    - 

Wheat  of   the  French 

bakers  -    -     -    -    - 

Flour  of  the  Paris  hos- 
pitals (2d  quality)     - 
Ditto  (3d  quality)    -     - 


Water. 

Gluten. 

Starch. 

Sugar. 

Gum. 

Bran. 

Total. 

Water 
of  dough 

10-0 

10-96 

71-49 

4-72 

3-32 

100-49 

50-3 

12-0 

14-55 

56-50 

8-48 

4-90 

2-3 

98-73 

51-2 

10-0 

8-0 

12-0 

12-00 

12-10 

7-30 

62-00 
70-84 
72-00 

7-56 
4-90 
5-42 

5-80 
4*60 
3-30 

1-2 

98-42 
100-41 
100-02 

54-8 
37-4 
37-2 

10-0 

10-20 

72-80 

4-20 

2-80 

- 

100-00 

40-6 

8-0 
12-0 

10-30 
902 

71-20 
67-78 

4-80 
4-80 

3-60 
4-60 

2-0 

97-90 
100-21 

37-8 
37-8 

The  following  table  of  analyses  merits  also  a  place  here. 


Species  of  Flour. 

Water. 

Gluten. 

Starch. 

Sugar. 

Gummigluten. 

Albumen. 

Bna. 

Flour  of  the  triticum  spelta 
Ditto  triticum  hybemum 
Ditto  common  wheat  -    - 
Ditto    wheat    and    rye 
mixed  (mastlin)     -    - 

1 

1 

6 

22- 
24- 
12-5 

9-80 

74- 
68- 
74-5 

75-50 

5-50 
5-0 
12- 

4-22 

1- 
1- 

2- 
3-28 

1-50 
1-50 

1-2 

The  first  two  of  the  above  analyses  were  made  by  Vogel,  the  third  by  Proust,  and  the 
fourth  by  Vauquelin. 

Analyses  of  the  flour  of  some  other  corns. 


Species  of  Flour. 


White  oatmeal    -    -    - 
Barley  meal    -    -    -    - 


Starch. 


Mucilage. 


59-00 
32-00 1 


2-5 
9- 


Gluten. 


Albumen. 


4-30 


Sugar. 


8-25 

Of  resin, 

2 


Husk. 


Of  a  fat  oil, 

2 


Hordein. 


55 


The  first  analysis  is  by  Vogel,  the  second  by  Proust. 

It  deserves  to  be  remarked,  that  the  flour  of  Odessa  contains  a  much  greater  quantit) 
cf  sugar  than  the  French  flour.  The  substance  indicated  in  the  preceding  table  by  th« 
Bune  of  gluten,  is  the  gluten  of  Beccaria ;  that  is  to  say,  a  mixture  of  gluten  and  vegelabl* 


BREAD. 


249 


albumen.  The  gum  of  wheat  is  not  quite  identical  with  ordinary  gum.  It  is  a  browr 
Motized  substance,  which,  when  treated  by  nitric  acid,  affords  no  mucic  acid,  but  oxali< 
acid  and  the  bitter  principle  of  Welter.     It  contains  besides  superphosphate  of  lime. 

The  last  column  of  the  first  table  exhibits  the  quantity  of  water  necessary  to  convert 
the  flour  into  dough  of  the  ordinary  consistence,  and  it  is  usually  proportional  to  the 
quantity  of  gluten.  The  hard  wheat  of  Odessa  forms  an  exception  in  this  respect ;  the 
reason  of  the  difference  being  that  the  starch  contained  in  this  flour  is  not  as  in  or- 
dinary flour  in  a  fine  powder,  but  in  small  transparent  grains,  which  resemble  pounded 
gum,  and  absorb  less  water  than  pulverulent  starch. 

The  triticum  monococcon,  according  to  Zenneck,  contains  in  its  unsifted  flour,  16-334 
of  gluten  and  vegetable  albumen ;  64-838  of  starch ;  1 1-347  of  gum,  sugar,  and  extractive ; 

ZirfL     r  "^^^   ^'^^^   ^®"^  ^^°'"^*  ^^'^3^  ^^  ^^"l^n  an^  vegetable  albumen; 

76-459  of  starch;  7-198  of  sugar,  gum,  and  extractive;  0-807  of  husky  matter.  It  is 
difficult  to  conceive  how  such  great  quantities  of  gluten,  albumen,  and  extractive  matter 
oould  disappear  m  the  sifting.  The  triticum  spelta  contains  in  100  parts  of  the  finest 
flour,  22-5  of  a  soft  and  humid  gluten,  mixed  with  vegetable  albumen  ;  74  of  starch,  and 
5-5  of  sugar.    Here  we  have  an  excess  of  2  parts  in  the  iOO. 

Wheat  furnishes  very  little  ashes  by  incineration,  not  more  than  0-15  per  cent,  of  the 
weight;  containing  superphosphates  of  soda,  lime,  and  masnesia. 

The  object  of  baking  is  to  combine  the  gluten  and  starch  of  the  flour  into  a  homo- 
geneous substance,  and  to  excite  such  a  vinous  fermentative  action,  by  means  of  its 
saccharine  matter,  as  shall  disengage  abundance  of  carbonic  acid  gas  in  it  for  making 
an  agreeable,  soft,  succulent,  spongy,  and  easily  digestible  bread  The  two  evils  to  be 
avoided  in  baking  are  hardness  on  the  one  hand,  and  pastiness  on  the  other.  Well-made 
bread  is  a  chemical  compound,  in  which  the  gluten  and  starch  cannot  be  recognised 
or  separated,  as  before,  by  a  stream  of  water.  When  flour  is  kneaded  into  a  dough, 
and  spread  into  a  cake,  this  cake,  when  baked,  will  be  homy  if  it  be  thin,  or  if  thick, 
will  be  tough  and  clammy;  whence  we  see  the  value  of  that  fermentative  process,  which 
generates  thousands  of  little  cells  in  the  mass  or  crumb,  each  of  them  dry,  yet  tender 
and  succulent,  through  the  intimate  combination  of  the  moisture.  By  this  constitution 
11  becomes  easily  soluble  in  the  juices  of  the  stomach,  or,  in  other  words,  light  of  diges- 
tion. It  18  moreover  much  less  liable  to  turn  sour  than  cakes  made  from  unfermented 
dongh. 

Rye,  which  also  forms  a  true  spongy  bread,  though  inferior  to  that  of  wheat,  consists 
of  similar  ingredients;  namely,  61-07  of  starch;  9-48  of  gluten ;  3-28  of  vegetable 
albumen;  3-28  of  uncrj^stallizable  sugar;  11-09  of  gum;  6-38  of  vegetable  fibre;  the 
joss  upon  the  100  parts  amounted  to  5-62,  includina:  an  acid  whose  nature  the  analvst, 
M.  Emhof,  did  not  determine.  Rye  flour  contains  also  several  salts,  principally  the 
phosphates  of  lime  and  magnesia.  This  kind  of  grain  forms  a  dark-colored  bread 
reckoned  ver>' wholesome;  comparatively  little  used  in  this  country,  but  very  much  in 
France,  Germany,  and  Belgium. 

Dough  fermented  with  the  aid  either  of  leaven  or  yeast,  contains  little  or  none  of  the 
saccharine  matter  of  the  flour,  but  in  its  stead  a  certain  portion,  neariy  half  il^weight, 
of  spirit,  which  imparts  to  it  a  vinous  smell,  and  is  volatilized  in  the  oven;  whence  it 
might  be  condensed  into  a  crude  weak  alcohol,  on  the  plan  of  Mr.  Hick*s  patent,  were  it 
worth  while.  But  the  increased  complexity  of  the  baking  apparatus  will  probably  prove 
an  effectual  obstacle  to  the  commercial  success  of  this  project,  upon  which  already  up- 
wards of  £20,000  sterling  have  been  squandered. 

That  the  sugar  of  the  flour  is  the  true  element  of  the  fermentation  preposterously 
called  panary,  which  dough  undergoes,  and  that  the  starch  and  gluten  have  nothing  to 
do  with  it,  may  be  proved  by  decisive  experiments.  The  vinous  fermentation  continues 
tm  the  whole  sugar  is  decomposed,  and  no  longer ;  when,  if  the  process  be  not  checked 
by  the  heat  of  baking,  the  acetous  fermentation  will  supervene.  Therefore,  if  a  little 
sugar  be  added  to  a  flour  which  contains  little  or  none,  its  dough  will  become  susceptible 
01  fermenting,  with  extrication  of  gas,  so  as  to  make  spongy  succulent  bread.  But  since 
this  sponginess  is  produced  solely  by  the  extrication  of  gas,  and  its  expansion  in  the  heat 
01  the  oven,  any  substance  capable  of  emitting  gas,  or  of  being  converted  into  it  under 
these  circumstances,  will  answer  the  same  purpose.  Were  a  solution  of  bicarbonate  ol 
wnmonia  obtained  by  exposing  the  common  sesqui-carbonate  in  powder  for  a  day  to  the 
air,  incorporated  with  the  dough,  in  the  subsequent  firing  it  will  be  converted  into 
vapor,  and  in  its  extrication  render  the  bread  very  porous.  Nay,  if  water  hfghly 
Impregnated  with  carbonic  acid  eas  be  used  for  kneading  the  dough,  the  resulting  bread 
Vill  be  somewhat  spongy.  Could  a  light  article  of  food  be  prepared  in  this  way,  then 
w  the  sugar  would  remam  undecomposed,  the  bread  would  be  so  much  the  sweeter,  and 
llie  more  nourishing.  How  far  a  change  propitious  to  digestion  takes  place  in  the 
constitution  of  the  starch  and  gluten,  during  the  fermentative  action  of  the  dough,  has 
•ot   been    hitherto   ascertained   by   precise   experiments.     Medical   practitioners,  who 


250 


BREAD. 


\i 


» 11 


t  i 


derive  an  enormous  revenue  from  dyspepsia,  should  take  some  pains  to  investigate  lhi« 
subject. 

Dr.  Colquhoun,  in  his  able  essay  upon  the  art  of  makins;  bread,  has  shown  that  its  texture, 
when  prepared  by  a  sudden  formation  and  disengagement  of  elastic  fluid  generated  within 
the  oven,  differs  remarkably  from  that  of  a  loaf  which  has  been  made  after  the  prepara- 
tory fermentation  with  yeast.  Bread  which  has  been  raised  with  the  common  carbonate 
of  ammonia,  as  used  by  the  pastry-cooks,  is  porous  no  doubt,  but  not  spongy  with  vesicu- 
lar spaces,  like  that  made  in  the  ordinary  way.  The  former  kind  of  bread  never  presents 
that  air-cell  stratification  which  is  the  boast  of  the  Parisian  baker,  but  which  is  almost  un- 
known in  London.  I  have  found  it,  moreover,  very  difficult  to  expel  by  the  oven  the  last 
portion  of  the  ammonia,  which  gives  both  a  tinge  and  a  taste  to  the  bread.  I  believe, 
however,  that  the  bicarbonate  would  be  nearly  free  from  this  objection,  which  operates 
so  much  against  the  sesqui-carbonate  of  the  shops. 

In  opposition  to  Mr.  Edlin's  account  of  the  excellent  quality  of  bread  made  by  im- 
pregnating dough  with  carbonic  acid  gas,*  Dr.  Colquhoun  adduces  Vogel's  experiments,* 
which  show  that  such  dough,  when  baked,  after  having  been  kept  in  a  warm  siti^ation 
during  the  usual  time,  afforded  nothing  better  than  a  Aard  cake,  which  had  no  resem- 
blance to  common  bread.  Vogel  further  states,  as  illustrative  of  the  general  necessity 
of  providing  a  sufficient  supply  of  disengaged  elastic  fluid  within  the  dough,  before 
baking  it  at  all,  that  when  he  made  various  attempts  to  form  a  well-raised  vesicular  loaf, 
within  the  oven,  by  mixing  flour  with  carbonate  of  magnesia,  or  with  zinc  filings,  and 
then  kneading  it  into  a  paste  by  means  of  water,  acidulated  with  sulphuric  acid,  he  al- 
ways met  with  complete  failure  and  disappointment.  Dr.  Colquhoun  performed  a  series 
of  well-devised  experiments  on  this  subject,  which  fully  confirmed  Vogel's  results,  and 
prove  that  a  proper  spongy  bread  cannot  be  made  by  the  agency  of  either  carbonic  acid 
water,  or  of  mixtures  of  sesqui-carbonate  of  soda,  and  tartaric  acid.  The  bread  proved 
doughy  and  dense  in  every  case,  though  less  so  with  the  latter  mixture  than  the  former. 
No  loaf  bread  can,  indeed,  be  well  made  by  any  of  these  two  extemporaneous  systems, 
because  they  are  inconsistent  with  the  thorough  kneading  of  the  dough.  It  is  this  pro- 
cess which  renders  dough  at  once  elastic  enough  to  expand  when  carbonic  acid  gas  is 
generated  within  it,  and  cohesive  enough  to  confine  the  gas  when  it  is  generated.  The 
whole  gas  of  the  loaf  is  disengaged  in  its  interior  by  a  continuous  fermentation,  a(\er  all 
the  processes  of  kneading  have  been  finished ;  for  the  loaf,  after  being  kneaded,  weighed 
out,  and  shaped,  is  set  aside  till  it  expands  gradually  to  double  its  bulk,  before  it  is  put 
into  the  oven.  But  when  a  dough  containing  sesqui-carbonate  of  soda  is  mixed  with  one 
containing  muriatic  acid,  in  due  proportions  to  form  the  just  dose  of  culinary  salt,  the  gas 
escapes  during  the  necessary  incorporation  of  the  two,  and  the  bread  formed  from  it  is 
dense  and  hard.  Dr.  Whiting  has,  however,  made  this  old  chemical  process  the  subject 
of  a  new  patent  for  baking  bread. 

When  the  baker  prepares  his  dough,  he  takes  a  portion  of  the  water  needed  for 
the  batch,  having  raised  its  temperature  to  from  70°  to  100°  F.,  dissolves  a  certain 
proporiiou  of  his  salt  in  it,  then  adds  the  yeast,  and  a  certain  quantity  of  his  flour. 
This  mixture,  called  the  sponge,  is  next  covered  up  in  the  small  kneading-trough, 
alongside  of  the  large  one,  and  let  alone  for  setting  in  a  warm  situation.  In  about  an 
hour,  signs  of  vinous  fermentation  appear,  by  the  swelling  and  heaving  up  of  the  sponge, 
in  consequence  of  the  generation  of  carbonic  acid;  and  if  it  be  of  a  semi-liquid  con- 
sistence, large  air  bubbles  will  force  their  way  to  the  surface,  break,  and  disappear  in 
rapid  succession.  But  when  the  sponge  has  the  consistence  of  thin  dough,  it  confines  the 
gas,  becomes  thereby  equably  and  progressively  inflated  to  double  its  original  volume ; 
when  no  longer  capable  of  containing  the  pent-up  air,  it  bursts  and  subsides.  This 
process  of  rising  and  falling  alternately  might  be  carried  on  during  twenty-four  hours, 
but  the  baker  has  learned  by  experience  to  guard  against  allowing  full  scope  to  the  fer- 
mentative principle.  He  generally  interferes  after  the  first,  or  at  furthest  after  the 
second  or  third  dropping  of  the  sponge ;  for  were  he  not  to  do  so,  the  bread  formed  with 
such  dough  would  be  invariably  found  sour  to  the  taste  and  the  smeU.  Therefore  he 
adds  at  this  stage  to  the  sponge  the  reserved  proportions  of  flour,  salt,  and  water,  which 
are  requisite  to  make  the  dough  of  the  desired  consistence  and  size;  and  next  mcor- 
porates  the  whole  together  by  a  long  and  laborious  course  of  kneading.  When  this 
operation  has  been  continued  till  the  fermenting  and  the  fresh  dough  have  been  intimately 
blended,  and  till  the  glutinous  matter  of  both  is  worked  into  such  union  and  consistence 
that  the  mass  becomes  so  tough  and  elastic  as  to  receive  the  smart  pressure  of  the 
iiand  without  adhering  to  it,  the  kneading  is  suspended  for  some  time.  The  dough  is 
ftow  abandoned  to  itself  for  a  few  hours,  during  which  it  continues  in  a  state  of  active 
fermentation  throughout  its  entire  mass.  Then  it  is  subjected  to  a  second  but  much 
leas  laborious  kneading,  in  order  to  distribute  the  generated  gas  as  evenly  as  possibte 


'*  Treatiw  on  the  Art  of  Bread  Making,  p.  56. 


BREAD. 


251 


ao.onf  its  parts,  so  that  they  may  all  partake  equally  of  the  vesicular  structure.  Aftei 
this  second  kneading,  the  dough  is  weighed  out  into  the  portions  suitable  to  the  size  of 
bread  desired ;  which  are  of  course  shaped  into  the  proper  forms,  and  once  more  set 
aside  in  a  warm  situation.  The  continuance  of  the  fermentation  soon  disengages  a  fresh 
quantity  of  carbonic  acid  gas,  and  expands  the  lumps  to  about  double  their  pristine  volume. 
These  are  now  ready  for  the  oven,  and  when  they  finally  quit  it  in  the  baked  state,  are 
about  twice  the  size  they  were  when  they  went  in.  The  generation  of  the  due  quantity 
of  gas  should  be  complete  before  the  lumps  are  transferred  to  the  oven;  because  whenever 
they  encounter  its  heat,  the  process  of  fermentation  is  arrested ;  for  it  is  only  the  previ- 
ously existing  air  which  gets  expanded  throughout  every  part  of  the  loaf,  swells  out  its 
volume,  and  gives  it  the  piled  and  vesicular  texture.  Thus  the  well-baked  loaf  is  com- 
posed of  an  infinite  number  of  cellules  filled  with  carbonic  acid  gas,  and  apparently  lined 
with  a  glutinous  membrane  of  a  silky  softness.  It  is  this  which  gives  the  light,  elastic, 
porous  constitution  to  bread. 

After  sufltering  the  fermentative  process  to  exhaust  itself  in  a  mass  of  dough,  and  the 
dough  to  be  brought  into  that  state  in  which  the  additk)n  of  neither  yeast,  nor  starch,  nor 
gluten  will  produce  any  effect  in  restoring  that  action,  if  we  mix  in  4  per  cent,  of  saccha- 
rine matter,  of  any  kind,  with  a  little  yeast,  the  process  of  fermentation  will  immediately 
re-commence,  and  pursue  a  course  as  active  and  lengthened  as  at  first,  and  cease  about 
the  same  period.* 

This  experiment,  taken  in  connexion  with  the  facts  formerly  stated,  proves  that  what 
was  called  panary  fermentation,  is  nothing  but  the  ancient  and  well-known  process  of  the 
vinous  fermentation  of  sugar,  which  generates  alcohol.  There  seems  to  be  but  one  ob- 
jection to  the  adoption  of  this  theory.  After  the  loaf  is  baked,  there  is  found  in  its  com- 
position nearly  as  much  saccharine  matter  as  existed  in  the  flour  before  fermentation. 
M.  Vogel  stales  that  in  the  baked  bread  there  remains  3'6  parts  of  sugar,  out  of  the 
5  parts  which  it  orisinally  contained.  Thus,  in  100  parts  of  loaf  bread  prepared  with 
wheaten  flour,  distilled  water,  and  yeast  without  the  admixture  of  any  common  salt,  he 
found  the  following  ingredients  : — 

Sugar  ...  3.6 

Torrefied  or  gummy  starch  -        18'0 

Starch  -  -  -  53-5 

Gluten,  combined  with  a  little  starch,  20*75 
Exclusive  of  carbonic  acid,  muriate  of  lime,  phosphate  of  lime,  &.c. 
It  must  be  borne  in  mind  that  in  every  loaf  the  process  of  fermentation  has  been  pre- 
maturely checked  by  the  baker's  oven,  and  therefore  the  saccharine  constituent  can  never 
be  wholly  decomposed.  It  seems  certain,  also,  that  by  the  action  of  gluten  upon  the 
starch  in  the  early  stage  of  the  firing,  a  quantity  of  sugar  will  be  formed  by  the  saccha- 
rine fermentation ;  which  we  have  explained  in  treating  of  Beka. 

Several  masses  of  dough  were  prepared  by  Dr.  Colquhoun  in  which  pure  wheat  starck 
was  mixed  with  common  flour,  in  various  proportions.  In  some  of  the  lumps  thb  starch 
had  been  gelatinized,  with  the  minimum  of  hot  water,  before  it  was  added  to  the  flour. 
After  introducing  the  usual  dose  of  salt,  the  dough  was  thoroughly  kneaded,  set  apart  for 
the  proper  period,  allowed  to  ferment  in  the  accustomed  way,  and  then  baked  in  the  oven. 
In  outward  appearance,  increase  of  bulk,  and  vesicular  texture,  none  of  them  differed 
materially  from  a  common  loaf,  baked  along  with  them  for  the  sake  of  comparison ; 
except  that  when  the  starch  considerably  exceeded  the  proportion  of  flour  in  the  lump, 
the  loaf,  though  whiter,  had  not  risen  so  well,  being  somewhat  less  vesicular.  But,  on 
tasting  the  bread  of  each  loaf,  those  which  contained  most  gelatinized  starch  were  unex- 
pectedly found  to  be  the  sweetest.  The  other  loaves,  into  which  smaller  quantities  of 
the  gelatinized  starch  had  been  introduced,  or  only  some  dry  starch,  had  no  sweetish 
taste  whatever  to  distinguish  them  from  ordinary  bread.  These  facts  seem  to  establish 
the  conclusion,  that  the  presence  of  gelatinous  starch  in  bread  put  into  the  oven,  is  a 
means  of  tbrming  a  certain  portion  of  saccharine  matter  within  the  loaf,  during  the  bak- 
ing process.  Now  it  is  more  than  probable  that  gelatinized  starch  does  exist,  more  or 
less,  in  all  loaves  which  have  been  fermented  by  our  usual  methods,  and  hence  a  certain 
quantity  of  sugar  will  necessarily  be  generated  at  its  expense,  by  the  action  of  heaU 
Thus  the  diflSculty  started  by  M.  Vogel  is  sufficiently  solved ;  and  there  remains  no  doubt 
that,  in  the  saccharine  principle  of  flour,  the  fermentation  has  its  origin  and  end,  while  dough 
is  under  fermentation. 

The  source  of  the  sourness  which  supervenes  in  bread,  under  careless  or  unskilful 
hands,  had  been  formerly  ascribed  to  each  of  all  the  constituents  of  flour ;  to  its  gluten. 
Its  starch,  and  its  sugar;  but  erroneously,  as  we  now  see  :  for  it  is  merely  the  result  of 
the  second  fermentation  which  always  succeeds  the  vinous,  when  pushed  improperly  too 
far.    It  has  been  universally  taken  for  granted  by  authors,  that  the  acid  thus  generated 


*  Dr.  CoIqoliMa,  in  Annals  of  Philoeopby  for  1836,  toI.  zii.  p.  171 


\ } 


252 


BREAD. 


BREAD. 


263 


\U 


in  dough  is  the  acetic.  But  there  appear  good  grounds  to  believe  that  it  is  frequently 
a  less  volatile  acid,  probably  the  lactic,  particularly  when  the  process  has  been  tardy, 
from  the  imperfection  of  the  yeast  or  the  bad  quality  of  the  flour.  The  experiments  of 
Vogel,  Braconnot,  and  others,  prove  that  the  latter  acid  is  generated  very  readily,  and  in 
considerable  quantity  during  the  spontaneous  decomposition  of  a  great  many  vegetable 
substances,  when  in  a  state  of  humidity.  The  presence  of  lactic  acid  would  account 
for  the  curious  fact,  that  the  acidity  of  unbaked  dough  is  much  more  perceptible  to  the 
taste  than  to  the  smell;  while  the  sourness  of  the  same  piece  of  bread,  after  coming  out 
of  the  oven,  is,  on  the  contrary,  much  more  obvious  to  the  olfactory  organs  than  to  the 
palate.  But  this  is  exactly  what  ought  to  happen,  if  the  lactic  acid  contributes,  in  con- 
junction with  the  acetic,  to  produce  the  acescence  of  the  dough.  At  the  ordinary  tem- 
perature of  a  bakehouse,  the  former  acid,  though  very  perceptible  in  the  mouth,  is  not 
distinguishable  by  the  nostrils;  but  as  it  is  easily  decomposed  by  heat,  no  sooner  is  it  ex- 
posed to  the  high  temperature  of  the  oven,  than  it  is  resolved,  in  a  great  measure,  into 
acetic  acid,*  and  thus  becomes  more  manifest  to  the  sense  of  smell,  and  less  to  that  of 
taste.  This  theory  seems  to  explain  satisfactorily  all  the  phenomena  accompanying  the 
progress  of  fermentation  in  baker's  dough,  and  also  some  of  its  results  in  the  process  of 
baking  which  do  not  easily  admit  of  any  other  solution. 

There  are  extremely  simple  and  effectual  methods  for  enabling  the  baker  to  adopi 
measures  either  to  prevent  or  correct  the  evil  of  acescence,  and  these  are  to  neutralize 
the  acid  by  the  due  exhibition  of  an  alkali,  such  as  soda ;  or  an  alkatme  earth,  such  as 
magnesia  or  chalk.  And  it  affords  a  striking  proof  of  how  much  the  artisan  has  been 
accustomed  to  plod,  uninquiring  and  uninformed,  over  the  same  ground,  that  a  remedy 
so  safe  and  so  economical,  should  remain  at  this  day  unthought  of  and  unemployed  by 
most  of  the  manufacturers  of  bread  in  the  United  Kingdom.  The  introduction  of  a 
small  portion  of  carbonate  of  soda  will  rectify  any  occasional  error  in  the  result  of  the 
so  called  panary  fermentation,  and  will,  in  fact,  restore  the  dough  to  its  pristine  sweet- 
ness. The  quantity  of  acetate  of  soda,  which  will  be  thus  present  in  the  bread,  will  be 
altogether  inconsiderable  ;  and  as  it  has  no  disagreeable  taste,  and  is  merely  aperient  to 
the  bowels  in  a  very  mild  degree,  it  can  form  no  objection  in  the  eye  of  the  public 
police.  The  restoration  of  dough  thus  tainted  with  acid,  and  its  conversion  into 
pleasant  and  wholesome  bread,  has  been  suflSciently  verified  by  experiment.  But, 
according  to  Mr.  Edmund  Davy,  carbonate  of  magnesia  may  be  used  with  still  greater 
advantage,  as  during  the  slow  action  of  the  acid  upon  it,  the  carbonic  acid  evolved 
serves  to  open  up  and  lighten  bread  which  would  otherwise  be  dense  and  doughy  from 
the  indifferent  quality  of  the  flour.  Here,  however,  the  dangerous  temptation  lies  with 
a  sordid  baker  to  use  cheap  or  damaged  flour,  and  to  rectify  the  bread  made  of  it  by 
chemical  agents,  innocent  in  themselves,  but  injurious  as  masks  of  a  bad  raw  material. 
When  sour  yeast  must  be  used,  as  sometimes  happens  with  the  country  bakers,  or  in 
private  houses  at  a  distance  from  beer  breweries,  there  can  be  no  harm,  but,  on  the 
contrary,  much  propriety,  in  correcting  its  acidity,  by  the  addition  of  as  much  carbonate 
of  soda  to  it  as  will  effect  its  neutralization,  but  nothing  more.  When  sour  yeast  has 
been  thus  corrected,  it  has  been  found,  in  practice,  to  possess  its  fermentative  power  un- 
mipaired,  and  to  be  equally  eflicacious  with  fresh  formed  yeast,  in  making  good  palata- 
ble loaves. 

We  have  seen  that,  in  baking,  about  one  fourth  of  the  starch  is  converted  into  a 
matter  possessing  the  properties  of  British  gum  (see  Starch),  and  also  that  the  gluten, 
though  not  decomposed,  has  its  particles  disunited,  and  is  not  so  tough  and  adhesive  as 
it  is  in  the  flour.  This  principle  is  also,  as  we  have  said,  useful  in  cementing  all  the 
particles  of  the  dough  into  a  tenacious  mass,  capable  of  confining  the  elastic  fluid  gene- 
rated by  the  vinous  fermentation  of  the  sugar.  Starch  is  the  main  constituent,  the  basil 
of  nourishment  in  bread,  as  well  as  in  all  farinaceous  articles  of  food.  The  albumen  al- 
to of  the  wheat,  being  coagulated  by  the  heat  of  the  oven,  contributes  to  the  setting  of 
the  bread  into  a  consistent  elastic  body. 

In  the  mills  in  the  neighborhood  of  London,  no  less  than  seven  distinct  sorts  of  flout 
are  ground  out  of  one  quantity  of  wheat.    These  are  for  one  quarter — 


Fine  flour 
Seconds    - 
Fine  middlings 
Coarse  middlings 
Bran     - 
Twenty-penny  - 
Pollard    -     - 


5  bushels  3  pecks. 

0  2 

0  1 

0  0*5 

3  0 

3  0 
2 


14 


2-5 


*Ben«liaa. 


So  that  we  have  nearly  a  double  bulk  of  flour,  or  14  bushels  and  2^  pecks  from  8  busheb 
of  wheat.  In  the  sifting  of  the  flour  through  the  bolter,  there  is  a  fine  white  angular  meal 
obtained  called  sharps,  which  forms  the  central  part  of  the  grain.  It  is  consumed  partly 
by  the  fine  biscuit  bakers.  The  bakers  of  this  country  were  formerly  bound  by  law  to  bake 
three  kinds  of  bread,  the  wheateriy  standard  wheaten,  and  the  household;  marked  respec- 
tively with  a  W,  S  W,  and  H,  and  if  they  omitted  to  make  these  marks  on  their  bread 
they  were  liable  to  a  penalty.  The  size  of  the  loaves  were  usually  peck,  half-peck, 
quartern,  and  half-quartern  ;  the  weights  of  which,  within  48  hours  of  their  being  baked, 
should  have  been  respectively  17  lbs.  6  oz. ;  8  lbs.  11  oz. ;  4  lbs.  5  oz.  8  dr. ;  and  4  lbs. 
2  oz.  14  dr.  In  general  they  weigh  about  one  seventh  more  before  they  enter  the  oven, 
or  they  lose  one  seventh  of  their  weight  in  baking.  The  French  bread  loses  fully  one 
sixth  in  the  oven,  owing  chiefly  to  its  more  oblong  thin  shape,  as  compared  to  the 
cubical  shape  of  the  English  bread.  But  this  loss  of  weight  is  very  variable,  being  de- 
pendant upon  the  quality  of  the  wheaten  flour,  and  the  circumstances  of  baking.  The 
present  law  in  England  defines  the  quartern  loaf  at  4  lbs.,  and  subjects  the  baker  to  a 
penally  if  the  bread  be  one  ounce  lighter  than  the  standard.  Hence  it  leaves  the  baker, 
in  self-defence,  to  leave  it  in  rather  a  damp  and  doughy  state.  But  there  is  much  light 
bread  sold  in  London.  I  have  met  with  quartern  loaves  of  3  lbs.  10  oz.  A  sack  of  flour 
weighing  280  lbs.  was  presumed  by  the  framers  of  our  former  parliamentary  acts,  for  the 
assize  of  bread,  to  be  capable  of  being  baked  into  80  loaves.  If  this  proportion  had  been 
correct,  one  fifth  part  of  our  quartern  loaf  must  consist  of  water  and  salt,  and  four  fifths 
of  flour.  But  in  general,  of  good  wheaten  flour,  three  parts  will  take  up  one  part  of 
water ;  so  that  the  sack  of  flour  should  have  turned  out,  and  actually  did  turn  out,  more 
than  80  loaves.    At  present  with  4  lb.  bread  it  may  well  yield  92  loaves. 

The  following  statement  of  the  system  of  bakiag  at  Paris,  I  received  in  1835  from  a 
very  competent  judge  of  the  business. 

1,000  kilogrammes  of  wheat=5  quarters  English,  cost  200  fr.,  and  yield  800  kilos, 
of  flour  of  the  best  white  quality,  equivalent  to  5J-  sacks  French.    Hence  the  sack  of 


flour  costs  40  francs  at  the  mill,  and  including  the  carriage  to  Paris,  it  costs  45  or  46 
francs. 

The  profit  of  the  flour  dealer  is  about  3|  francs,  and  the  sale  price  becomes  from  43  to 
50  francs. 

Bread  manufactured  from  the  above, 

/^      J     »  1     /.  £    s.    d,         £    9,    d. 

One  day's  work  of  an  ordinary  baker,  who  makes  four  batches 
in  a  day,  consists  of  3  sacks  at  50  francs,  or  21.  sterling  each 

Salt2f  lbs.  at2rf.  perlb . 

Yeast  or  leaven  3  lbs.  at  5(f .      - 


Total  cost  of  materials  ...... 

Expenses  of  Baking. 
Three  workmen  at  different  rates  of  wages,  15  francs      - 
Fire-wood  0,  as  the  charcoal  produced  pays  for  it    - 
General  expenses,  such  as  rent,  taxes,  interest  of  capital,  &.c. 


For  this  sum  315  loaves  are  made,  being  105  for  every  sack 
of  flour  weighing  156-66  kilos,  or  344#  lbs.  avoird.  One 
loaf  contains  therefore  ^\^^^  =  3-282  lbs.,  and  as  100  lbs. 
of  flour  in  Parisian  baking  are  reckoned  to  produce 
127  lbs.  of  bread,  each  loaf  will  weigh  4-168  lbs.,  avoird., 
and  will  cost  7/.  5*.  8Jd.  divided  by  315  =  5^.  very 
nearly.  The  value  of  315  loaves  at  the  sale  price  of  Qd. 
will  be----... 


6 
0 
0 

0 
0 
1 

0 
3 

6 

1 

8i 

0    12 

0 

0    12 

0 

==   1 

4 

1     4 

0 

0 

7    5    Si 


7    17   6 


Upon  this  day's  work  the  clear  profit  is  therefore        -  -  0    11   61 

A  new  baking  establishment  has  been  recently  formed  at  the  Royal  Clarence 
VicJualUng  Estabhshment  at  Weevil,  near  Portsmouth,  upon  a  scale  of  magnitude  near- 
ly suflicient  to  supply  the  whole  royal  navy  with  biscuits,  and  that  of  a  very  superior 
description.  The  following  account  of  it  is  taken  from  the  United  Service  Journal. 
It  havmg  been  discovered  that  the  flour  supplied  to  government  by  contract,  had  in 
many  instances  been  most  shamefully  adulterated,  the  com  is  ground  at  mills  comprised 
Within  the  establishment,  by  which  means  the  introduction  of  improper  ingredients  is 
prevented,  and  precisely  the  proportion  of  bran  which  is  requisite  in  the  composition  of 
good  sea-biscuit  is  retained,  and  no  more.    The  flour-mill  is  furnished  with  ten  pairs  of 


254 


BREAD. 


BREAD. 


355 


I    hi 


:';i!f 


\n 


rtones,  by  which  40  bushels  ol  flour  may  be  ground  and  dressed  ready  for  baking,  in  an 
hour.    The  baking  establishment  consists  of  9  ovens,  each  13  feet  long  by  11  feet  \vide, 
and  17|  inches  in  height.     These  are  each  heated  by  separate  furnaces,  so  constructed 
that  a  blast  of   hot  air  and  fire  sweeps  ihrough   them,  and   gives  to  the  interior  the 
requisite  dose  of  heat  in  an  incredible   short   space  of  time.    The  first  operation  in 
making  the  biscuits  consists  in  mixing  the  flour,  or  rather  meal  and  water ;  13  gallons  of 
water  are  first  introduced  into  a  trough,  and  then  a  sack  of  the  meal,  weighing  280  lbs. 
When  the  whole  has  been  poured  in  by  a  channel  communicating  with  an  upper  room, 
a  bell  rings,  and  the  trough  is  closed.     An  apparatus  consisting  of  two  sets  of  what  are 
called  knives,  each  set  ten  in  number,  are  then  made  to  revolve  amongst  the  flour  and 
water  by  means  of  machinery.     This  mixing   operation  lasts  one  minute  and  a  half, 
during  which  time  the  double  set  of  knives  or  stirrers  makes  twenty-six  revolutions.     The 
next  process  is  to  cast  the  lumps  of  dough  under  what  are  called  the  breaking-rollers, — 
huge  cylinders  of  iron,  weighing  14  cwt.  each,  and  moved  horizontally  by  the  machinery 
along  stout  tables.    The  dough  is  thus  formed  into  large  rude  masses  6  feet  long  by  3 
feet  broad,  and  several  inches  thick.    At  this  stage  of  the  business,  the  kneading  is  still 
very  imperfect,  and  traces  of  dry  flour  may  still  be  detected.    These  great  masses  of 
dou^h  are  now  drawn  out,  and  cut  into  a  number  of  smaller  masses  about  a  foe  t  and  a 
half  long  by  a  foot  wide,  and  again  thrust  under  the  rollers,  which  is  repeated  until  the 
mixture  is  so  complete  that  not  the  slightest  trace  of  any  inequahry  is  discoverable  in  any 
part  of  the  mass.    It  should  have  been  stated  that  two  workmen  stand  one  at  each  side 
of  the  rollers,  and  as  the  dough  is  flattened  out  they  fold  it  up,  or  double  one  part  upon 
another,  so  that  the  roller  at  its  next  passage  squeezes  these  parts  together,  and  forces 
them  to  mix.    The  dough  is  next  cut  into  small  portions,  and  being  placed  upon  large 
flat  boards,  is,  by  the  agency  of  machinery,  conveyed  from  the  centre  to  the  extremity  of 
the  baking-room.     Here  it  is  received  by  a  workman,  who  places  it  under  what  is 
called  the  sheet  roller,  but  which,  for  size,  color,  and  thickness,  more  nearly  resembles 
a  blanket.    The  kneading  is  thus  complete,  and  the  dough  only  requires  to  be  cut  into 
biscuits  before  it  is  committed  to  the  oven.    The  cutting  is  efiected  by  what  is  called 
the  cutting-plate,  consisting  of  a  net-work  of  52  sharp-edged  hexagonal  frames,  each  as 
large  as  a  biscuit.    This  frame  is  moved  slowly  up  and  down  by  machinery,  and  the 
workman,  watching  his  opportunity,  slides    under   it   the   above-described    blanket  of 
dough,  which  is  about  the  size  of  a  leaf  of  a  dining-table ;  and  the  cutting-frame  in  its 
descent  indents  the  sheet,  but  does  not  actually  cut  it  through,  but  leaves  sufficient 
substance  to  enable  the  workman  at  the  mouth  of  the  oven  to  jerk  the  whole  mass  of 
biscuits  unbroken  into  it.    The  dough  is  prevented  sticking  to  the  cutting-frame  by 
the  following  ingenious  device :  between  each  of  the  cutter-frames  is  a  small  flat  open 
frame,  moveable  up  and  down,  and  loaded  with  an  iron  ball,  weighing  several  ounces. 
When  the  great  frame  comes  down  upon  the  dough,  and  cuts  out  52  biscuits,  each  of 
these  minor  frames  yields  to  the  pressure,  and  is  raised  up ;  but  as  soon  as  the  great 
frame  rises,  the  weight  of  the  balls,  acting  upon  the  little  frames,  thrusts  the  whole 
blanket  ofi",  and  allows  the  workmen  to  pull  it  out.     One  quarter  of  an  ho\ir  is  suflicient 
.t)  bake  the  biscuit,  which  is  afterwards  placed  for  three  days  in  a  drying  room,  heated 
to  85°  or  90",  which  completes  the  process."    The  following  statement  of  the  per- 
formance of  the  machinery  is  taken  from  actual  experiment ;  in  116  days,  during  68  of 
which  the  work  was  continued  for  only  7|  hours ;  and  during  48,  for  only  5f   hours 
each  day,  in  all  769  working  hours,  equal  to  77  days  of  10  hours  each ;  the  following 
quantity  of  biscuit  was  baked  in  the  9  ovens,  viz. :  12,307  cwt.  =  1,378,400  lbs.    The 
wages  of  the  men  employed  in  baking  this  quantity  amounted  to  273/.  10*.  9|(f. ;  if  it 
bad  been  made  by  hand,  the  wages  would  have  been  933Z.  9s.  lOd. ;  saving  in  the  wages 
cf  labor,  659/.  Is.  O^d.     In  this,  is  not  included  any  part  of  the  interest  of  the  sum  laid 
out  upon  the  machine,  or  expended  in  keeping  it  in  order.     But  in  a  very  few  years,  at 
such  an  immense  rate  of  saving,  the  cost  of  the  engine  and  other  machinery  will  be 
repaid.     This  admirable  apparatus  is  the  invention  of  T.  T.  Grant,  Esq.,  storekeeper  of 
the  Royal  Clarence  Victualling   Establishment,  who,  we  believe,  has   been  properly 
rewarded,  by  a  grant  of  2,000/.  from  government. 

The  labor  of  incorporating  the  ingredients  of  bread,  viz.,  flour,  water,  and  salt,  or 
kneading  dough,  is  so  great  as  to  have  led  to  the  contrivance  of  various  mechanical  modes 
of  producing  the  same  eflect.  One  of  the  most  ingenious  is  that  for  which  a  patent  was 
obtained  in  August,  1830,  by  Mr.  Edwin  Clayton.  It  consists  of  a  rotatory  kneading 
trough,  or  rather  barrel,  mounted  in  bearings  with  a  hollow  axle,  and  of  an  interior 
frame  of  cast  iron  made  to  revolve  by  a  solid  axle  which  passes  through  the  hollow  one ; 
in  the  frame  there  are  cutters  diagonally  placed  for  kneading  the  dough.  The  revolving 
frame  and  its  barrel  are  made  to  turn  in  contrary  directions,  so  as  greatly  to  save  time 
and  equalise  the  operation.  This  double  action  represents  kneading  by  the  two  hands, 
in  which  the  dough  is  inverted  from  time  to  time,  torn  asunder,  and  reunited  in  every 
ditferent  form.    The  mechanism  will  be  readily  understood  from  the  following  descriptioiu 


Fig.  190  exhibits  a  front  elevation  of  a  rotatory  kneading  trough,  constructed  according 
to  improvementii  specified  by  the  patentee,  the  barrel  being  shown  in  section ;  a  is  the 


barrel,  into  which  the  several  ingredients,  consisting  of  flour,  water,  and  yeast,  are  put, 
which  barrel  is  mounted  in  the  frame-work  b,  with  hollow  axles  c  and  d,  which  hoUow 
axles  turn  in  suitable  bearings  at  « ;  /  is  the  revolving  frame  which  is  mounted  in  the 
interior  of  the  barrel  a,  by  axles  g  and  h.  The  ends  of  this  revolving  frame  are  fast- 
ened, or  braced  together  by  means  of  the  oblique  cutters  or  braces  i,  which  act  upon  the 
dough  when  the  machine  is  put  in  motion,  and  thus  cause  the  operation  of  kneading. 

Either  the  barrel  may  be  made  to  revolve  without  the  rotatory  frame,  or  the  rotatory 
frame  without  the  barrel,  or  both  may  be  made  to  revolve  together,  but  in  opposite  ways. 
These  several  motions  may  be  obtained  by  means  of  the  gear-work,  shown  at  k,  L  and 
m,  as  will  be  presently  described. 

If  it  be  desired  to  have  the  revolving  motion  of  the  barrel  and  rotatory  frame  together, 
but  in  contrary  directions,  that  motion  may  be  obtained  by  fastening  the  hollow  axle  of 
the  wheel  n?,  by  means  of  a  screw  «,  to  the  axle  h,  of  the  rotatory  frame  /,  tight,  so  as 
they  wiU  revolve  together,  the  other  wheels  k  and  /  being  used  for  the  purjiose  of  re- 
versing the  motion  of  the  barrel.  It  wiU  then  be  found  that  by  turning  the  handle  o, 
the  two  motions  will  be  obtained. 

F\^^^^^^^^^^^  to  put  the  rotatory  frame  /,  only,  into  motion,  that  action  will  be  ob- 
tamed  by  loosening  tne  screw  n,  upon  the  axle  of  the  wheel  w,  when  it  will  be  found  that 
the  axle  h  will  be  made  to  revolve  freely  by  means  of  the  winch  o,  without  giving  motion 
to  the  wheels  /c,  /,  and  m,  and  thus  the  barrel  will  remain  stationary.  If  the  rotatory 
acUon  of  the  barrel  be  wanted,  it  will  be  obtained  by  turning  the  handle  p,  at  the  reverse 
end  of  the  machine,  which,  although  it  puts  the  gear  at  the  opposite  end  of  the  barrel 
into  motion,  yet  as  the  hollow  axle  of  the  wheel  m  is  not  fastened  to  the  axle  h.  by  the 
screw  n,  these  wheels  will  revolve  without  carrying  round  the  frame  /. 

M.  Kuhhnann,  Professor  of  Chemistry  at  Lille,  having  been  called  upon  several  times 
by  the  courts  of  justice  to  examine  by  chemical  processes  bread  suspected  of  containing 
substances  injurious  to  health,  collected  some  interesting  facts  upon  the  subject,  which 
were  published  under  the  direction  of  the  central  council  of  salubrity  of  the  department 
du  Nord. 

For  some  time  public  attention  had  been  drawn  to  an  odious  fraud  committed  by  a 
great  many  bakers  in  the  ftorth  of  France  and  in  Belgium — the  introduction  of  a  certain 
quantity  of  sulphate  of  copper  into  their  bread.  WJicn  the  flour  was  made  from  bad 
gram  this  adulteration  was  very  generally  practised,  as  was  proved  by  many  convictions 
and  confessions  of  the  guilty  persons.  When  the  dough  does  not  rise  well  in  the  fer- 
mentation (/6  pain  pousse  plat),  this  inconvenience  was  found  to  be  obviated  by  the  ad- 
diUon  of  blue  vitriol,  which  was  supposed  also  to  cause  the  flour  to  retain  more  water. 
The  quantity  of  blue  water  added  is  extremely  small,  and  it  is  never  done  in  presence  of 
strangers,  because  it  is  reckoned  a  valuable  secret.  It  occasions  no  economy  of  yeast, 
but  rather  the  reverse.  In  a  litre  (about  a  quart)  of  water,  an  ounce  of  sulphate  of 
copper  IS  dissolved  ;  and  of  this  solution  a  wine-glass  full  is  mixed  with  the  water  neces- 
sary for  50  quartern  or  4  pound  loaves. 

M.  Kuhlmann  justly  observes,  that  there  can  be  no  safety  whatever  to  the  public  when 
such  a  practice  is  permitted,  because  ignorance  and  avarice  are  always  apt  to  increase  the 
quantity  of  the  poisonous  water.  In  analyses  made  by  him  and  his  colleagues,  portions 
of  bread  were  several  times  found  so  impregnated  with  the  above  salt  that  they  had  ac- 
quired a  blue  color,  and  presented  occasionally  even  small  crystals  of  the  sulphate.  By 
acting  on  the  poisoned  bread  with  distilled  water,  and  testing  the  water  with  ferro-cya- 
nate  (prussiate)  of  potash,  the  reddish  brown  precipitate  or  tint  characteristic  of  copper 
Will  appear  even  with  small  quantities.  Should  the  noxious  impregnation  be  still  more 
nunvte,  the  bread  should  be  treated  with  a  very  dilute  nitric  acid,  either  directly  or  after 
incineration  m  a  platinum  capsule,  and  the  solution,  when  concentrated  by  evaporation, 
•ftould  bo  tested  by  the  ferro-cyanate  of  potash.  In  this  way,  a  one  seventy  thousandth 
part  of  sulphate  of  copper  may  be  detected. 


256 


BREAD. 


BREAD. 


I  i 


m  I 


] 


M.  Kuhlmaia  deduces,  from  a  series  of  experiments  on  baking  with  various  small 
quantities  of  sulphate  of  copper,  that  this  salt  exercises  an  extremely  energetic  action 
uix)n  the  fermentation  and  rising  of  the  dough,  even  when  not  above  one  seventy  thou- 
sandth part  of  the  weight  of  the  bread  is  employed ;  or  one  grain  of  sulphate  for  ten  pounds 
of  bread.  The  proportion  of  the  salt  which  makes  the  bread  rise  best  is  one  twenty  thou- 
sandth, or  one  grain  in  three  pounds  of  bread.  If  much  more  of  the  sulphate  be  added, 
the  bread  becomes  moist,  less  white,  and  acquires  a  peculiar  disagreeable  smell  like  that 
of  leaveh.  The  increase  of  weight  by  increased  moisture  may  amount  to  one  sixteenth 
without  the  bread  appearing  softer,  in  consequence  of  the  solidifying  quality  of  the  cop- 
per ;  for  the  acid  does  not  seem  to  have  any  influence ;  as  neither  sulphate  of  soda,  sul- 
phate of  iron,  nor  sulphuric  acid  have  any  analogous  power.  Alum  operates  like  blue 
vitriol  on  bread,  but  larger  quantities  of  it  are  required.  It  keeps  watery  and  raises  welU 
to  use  the  bakers'  terms. 

When  alum  is  present  in  bread  it  may  be  detected  by  treating  the  bread  with  Jistilled 
water,  filtering  the  water  first  through  calico,  and  next  through  filtering  paper,  till  it  be- 
comes clear ;  then  dividing  it  into  two  portions,  and  into  the  one  pouring  a  few  drops 
of  nitrate  or  muriate  of  barytes,  and  into  the  other  a  few  drops  of  water  of  ammonia.  In 
the  former  a  heavy  white  precipitate  indicating  sulphuric  acid  will  appear,  and  in  the 
latter  a  light  precipitate  of  alumina,  redissolubic  by  a  few  drops  of  solution  of  caustie 
potash. 

When  chalk  or  Paris  plaster  is  used  to  sophisticate  flour,  they  may  be  best  detected  by 
incinerating  the  bread  made  of  it,  and  examining  the  ashes  with  nitric  acid,  which  wiU 
dissolve  the  chalk  with  effervescence,  and  the  Paris  plaster  without.  In  both  cases  the 
calcareous  matter  may  be  demonstrated  in  the  solution,  by  oxalic  acid,  or  better  by  oxa- 
late of  ammonia. 

In  baking  puff-paste  the  dough  is  first  kneaded  along  with  a  certain  quantity  of  butter, 
then  rolled  out  into  a  thin  layer,  which  is  coaled  over  with  butter,  and  folded  face-wise 
many  times  together,  the  upper  and  under  surfaces  being  made  to  correspond.  This 
stratified  mass  is  again  rolled  out  into  a  thin  layer,  its  surface  is  besmeared  with  butter, 
and  then  it  is  folded  face-wise  as  before.  When  this  process  is  repeated  ten  or  a  dozen 
times,  the  dough  will  consist  of  many  hundred  parallel  laminae,  with  butter  interposed 
between  each  pair  of  plates.  When  a  moderately  thick  mass  of  this  is  put  into  the  oven, 
the  elastic  vapor  disengaged  from  the  water  and  the  butter,  diffuses  itself  between  each 
of  the  thin  laminae,  and  causes  them  to  swell  into  what  is  properly  called  puff-paste,  be- 
ing an  assemblage  of  thin  membranes,  each  dense  in  itself,  but  more  or  less  distinct  from 
the  other,  and  therefore  forming  apparently,  but  not  really,  light  bread. 

One  of  the  most  curious  branches  of  the  baker's  craft  is  the  manufacture  of  ginger- 
bread, which  contains  such  a  proportion  of  molasses,  that  it  cannot  be  fermented  b> 
means  of  yeast.  Its  ingredients  are  flour,  molasses  or  treacle,  butter,  common  potashes, 
and  alum.  After  the  butter  is  melted,  and  the  potashes  and  alum  are  dissolved  in  a 
little  hot  water,  these  three  ingredients,  along  with  the  treacle,  are  poured  among  the 
flour,  which  is  to  form  the  body  of  the  bread.  The  whole  is  then  incorporated  by 
mixture  and  kneading  into  a  stiff  dough.  Of  these  five  constituents  the  alum  is 
thought  to  be  the  least  essential,  although  it  makes  the  bread  lighter  and  crisper,  and 
renders  the  process  more  rapid ;  for  gingerbread  dough  reqftres  to  stand  over  several 
days,  sometimes  8  or  10,  before  it  acquires  that  state  of  porosity  which  qualifies  it  for 
the  oven.  The  action  of  the  treacle  and  alum  on  the  potashes  in  evolving  carbonic  acid, 
seems  to  be  the  gasefying  principle  of  gingerbread ;  for  if  ihe  carbonate  of  potash  is 
withheld  from  the  mixture,  the  bread,  when  baked,  resembles  in  hardness  a  piece  of 
wood. 

Treacle  is  always  acidulous.  Carbonate  of  magnesia  and  soda  may  be  used  as  suIk 
stitutes  for  the  potashes.  Dr.  Colquhoun  has  found  that  carbonate  of  magnesia  and 
tartaric  acid  may  replace  the  potashes  and  the  alum  with  great  advantage,  affording  a 
gingerbread  fully  more  agreeable  to  the  taste,  and  much  more  wholesome  than  the 
common  kind,  which  contains  a  notable  quantity  of  potashes.  His  proportions  are  one 
pound  of  flour,  a  quarter  of  an  ounce  of  carbonate  of  magnesia,  and  one  eighth  of  an 
ounce  of  tartaric  acid ;  in  addition  to  the  treacle,  butter,  and  aromatics,  as  at  present 
used.  The  acid  and  alkaline  earth  must  be  well  diffused  through  the  whole  dough. 
The  magnesia  should,  in  fact,  be  first  of  all  mixed  with  the  flour.  Pour  the  melted 
butter,  the  treacle,  and  the  acid  dissolved  in  a  liitle  water  all  at  once  among  the  flour, 
and  knead  into  a  consistent  dough,  which  being  set  aside  for  half  an  hour  or  an  hour  will 
be  ready  for  the  oven,  and  should  never  be  kept  unbaked  more  than  2  or  3  hoars.  The 
following  more  complete  recipe  is  given  by  Dr.  Colquhoun,  for  making  thin  ginger- 
bread  cakes : — 

Flour  1  lb. 

Treacle  0| 

Raw  sugar  o| 


257 


Butter  2  ox. 

Carbon,  magnesia  Of 

Tartaric  acid  0| 

Ginger 

Cinnamon 

Nutmeg  1 

This  compound  has  rather  more  butter  than  common  thin  gingerbread. 
I  shall  here  insert  a  passage  from  my  Dictionary  of  Chemistry,  as  published  in   1821 1 
as  it  may  prove  interesting  to  many  of  my  present  readers. 

«  Under  Process  of  Baking,  in  the  Supplement  to  the  Encyclopedia  Britannica,  we 
have  the  followmg  statement :— '  An  ounce  of  alum  is  then  dissolved  over  the  fire  in  a 
tin  pot,  and  the  solution  poured  into  a  large  tub,  caDed  by  the  bakers  the  seasoning- 
tub.  Four  pounds  and  a  half  of  salt  are  likewise  put  into  the  tub,  and  a  pailful  of  hot 
water.'— Foo^  note  on  this  passage.—*  In  London,  where  the  goodness  of  bread  is  esti- 
mated  ennrely  by  its  whiteness,  it  is  usual  with  those  bakers  who  employ  flour  of  an  in- 
ferior  quality,  to  add  as  much  alum  as  common  salt  to  the  dough ;  or,  in  other  words, 
the  quantity  of  salt  added  is  dim.nished  one  half,  and  the  deficiency  supplied  by  an  equal 
weight  of  alum.  This  improves  the  look  of  the  bread  very  much,  rendering'  it  much 
whiter  and  firmer.'  "  ^ 

In  a  passage  which  we  shall  presently  quote,  our  author  represents  the  bakers  of 
London  in  a  conspiracy  to  supply  the  citizens  with  bad  bread.  We  may  hence  infer 
that  the  full  allowance  he  assigns  of  2^  pounds  of  alum  for  every  2^  pounds  of  salt,  will 
be  adopted  in  converting  the  sack  of  flour  into  loaves.  But  as  a  sack  of  flour  weighs  280 
pounds,  and  furnishes  on  an  average  80  quartern  loaves,  we  have  2i  pounds  divided  bv 
on  «-  15750  grrains         m-r  •       /•      ^t  ..  .         . 

*"»  ^^  ~m =  ^^'    grains,  for  the  quantity  present,  by  this  writer,  in  a  London 

quartern  loaf.  Yet  in  the  very  same  page  (39th  of  vol.  ii.)  we  have  the  following 
passage :  "  Alum  is  not  added  by  all  bakers.  The  writer  of  this  article  has  been  assured 
by  several  bakers  of  respectability,  both  in  Edinburgh  and  Glasgow,  on  whose  testimony 
he  relies,  and  who  made  excellent  bread,  that  they  never  employed  anv  alum.  The  rea- 
son for  adding  it  given  by  the  London  bakers  is,  that  it  renders  the  bread  whiter,  and  en- 
ables them  to  separate  readily  the  loaves  from  each  other.  This  addition  has  been  aUeged 
by  medical  men,  and  is  considered  by  the  community  at  large,  as  injurious  to  the  health, 
by  occasioning  constipation.  But  if  we  consider  the  small  quantity  of  this  salt  added  by 
the  baker,  not  quite  5^  grains  to  a  quartern  loaf,  we  will  not  readily  admit  these  allega- 
tions. Suppose  an  individual  to  eat  the  seventh  part  of  a  quartern  loaf  a  day,  he  would 
only  swallow  eight  tenths  of  a  grain  of  alum,  or,  in  reality,  not  quite  so  much  as  half  a 
grain ;  for  one  half  of  this  salt  consists  of  water.  It  seems  absurd  to  suppose  that  half  a 
grain  of  alum,  swallowed  at  different  times  during  the  course  of  a  day,  should  occasion 
constipation."  Is  it  not  more  absurd  to  state  2\  pounds  or  36  ounces,  as  the  alum  adul- 
teration of  a  sack  of  flour  by  the  London  bakers,  and  within  a  few  periods  to  reduce  the 
adulteration  to  one  ounce  ? 

That  this  voluntary  abstraction  of  f  f  of  the  alum,  and  substitution  of  superior  and 
more  expensive  flour,  is  not  expected  by  him  from  the  London  bakers,  is  sufliciently  evi- 
dent from  the  following  story.  It  would  appear  that  one  of  his  friends  had  invented  a 
new  yeast  for  fermenting  dough,  by  mixing  a  quart  of  beer  barm  with  a  paste  made  of 
ten  pounds  of  flour  and  two  gallons  of  boiling  water,  and  keeping  this  mixture  warm  for 
MX  or  eight  hours. 

"Yeast  made  in  this  way,"  says  he,  « answers  the  purposes  of  the  baker  much  better 
than  brewers'  yeast,  because  it  is  clearer,  and  free  from  the  hop  mixture  which  sometimes 
mjures  the  yeast  of  the  brewer.  Some  years  ago  the  bakers  of  London,  sensible  of  the 
superiority  of  this  artificial  yeast,  invited  a  company  of  manufacturers  from  Glasgow 
to  establish  a  manufactory  of  it  in  London,  and  promised  to  use  no  other.  About 
5,000/.  accordingly  was  laid  out  on  buildings  and  materials,  and  the  manufactory  was 
begun  on  a  considerable  scale.  The  ale-brewers,  finding  their  yeast,  for  which  thev  had 
drawn  a  gaod  price,  lie  heavy  on  their  hands,  invited  aZZ  the  journeymen  bakers  to 'their 
cellars,  gave  them  their  full  of  ale,  and  promised  to  regale  them  in  that  manner  every 
day,  provided  they  would  force  their  masters  to  take  all  their  yeast  from  the  ale-brewers. 
The  journeymen  accordingly  declared,  in  a  body,  that  they  would  work  no  more  for  their 
masters  unless  they  gave  up  taking  any  more  yeast  from  the  manufactory.  The  masters 
were  obliged  to  comply ;  the  new  manufactory  was  stopped,  and  the  inhabitants  of  Lon- 
don were  obliged  to  continue  to  eat  worse  bread,  because  it  was  the  interest  of  the  ale- 
brewers  to  sell  the  yeast.  Such  is  the  influence  of  journeymen  bakers  in  the  metropolii 
of  England!" 

This  doleful  diatribe  seems  rather  extravagant;  for  surely  beer  yeast  can  derive 
nothing  noxious  to  a  porter  drinking  people,  from  a  slight  impregnation  of  hops ;  while 
It  must  form  probably  a  more  energetic  ferment  than  the  fermented  paste  of  the  new 
eompany,  which  at  any  rate  could  be  prepared  in  six  or  eight  hours  by  any  baker  wlw 


;1J1. 


liiti; 


t 


I 


11 


;! 


258 


BREAD. 


BREAD. 


3fi» 


found  it  to  ansTver  his  purpose  of  making  a  pleasant  eating  bread.  But  it  is  a  very  serioiii 
thin?  for  a  lady  or  gentleman  of  sedentary  habits,  or  infirm  constitution,  to  have  their  di- 
gestfve  process  daily  vitiated  by  daroi^ed  flour,  whitened  with  197  grains  of  alum  pei 
quartern  loaf.  Acidity  of  stomach,  indigestion,  flatulence,  headaches,  palpitation,  costiye- 
ness  and  urinary  calculi  may  be  the  probable  consequences  of  the  habitual  introduction 
of  so  much  acidulous  and  acescent  matter. 

I  have  made  many  experiments  upon  bread,  and  have  found  the  proportion  of  alum  very 
variable.  Its  quantity  seems  to  be  proportional  to  the  badness  of  the  flour;  and  hence 
when  the  best  flour  is  used  no  alum  need  be  introduced.  That  alum  is  not  necessary  for 
giving  bread  its  utmost  beauty,  sponginess,  and  agreeableness  of  taste,  is  undoubted  ;  since 
the  bread  baked  at  a  very  extensive  establishment  in  Glasgow,  in  which  about  20  tons  of 
flour  were  regularly  converted  into  loaves  in  the  course  of  a  week,  united  every  quality 
of  appearance  with  an  absolute  freedom  from  that  acido-astringent  drug.  Six  pounds  of 
salt  were  used  for  every  sack  of  flour ;  which,  from  its  good  quality,  generally  afibrdcd 
83  or  84  quartern  loaves  of  the  legal  weight  of  four  pounds  five  ounces  and  a  half  each. 
The  loaves  lost  nine  ounces  in  the  oven. 

Every  baker  ought  to  be  able  to  analyze  his  flour.  He  may  proceed  as  follows : — A  duc- 
tile paste  is  to  be  made  with  a  pound  of  the  flour  and  a  sufficient  quantity  of  water,  and 
left  at  rest  for  an  hour ;  then  having  tied  across  a  bowl  a  piece  of  silken  sieve-stufl",  a 
little  below  the  surface  of  the  water  in  the  bowl,  the  paste  is  to  be  laid  upon  the  sieve  on 
a  level  with  the  water,  and  kneaded  tenderly  with  the  hand,  so  as  merely  to  wash  the 
Starchy  particles  out  of  it.  This  portion  of  the  flour  gets  immediately  diffused  through 
the  water,  some  of  the  other  constituents  dissolve,  and  the  gluten  alone  remains  upon  the 
filter.  The  water  must  be  several  times  renewed  till  it  ceases  to  become  milky.  The 
last  washings  of  the  gluten  are  made  out  of  the  sieve. 

The  whole  of  the  turbid  washings  are  to  be  put  into  a  tall  conical  glass  or  stoneware 
vessel,  and  allowed  to  remain  at  rest,  in  a  cool  place,  till  they  deposite  the  starch.  The 
clear  supernatant  liquor  is  then  decanted  off.  The  deposite  consists  of  starch,  with  a 
little  gluten.    It  must  be  washed  till  the  water  settles  over  it  quite  clear,  and  then  it  is 

to  be  dried.  n    t     «      . 

The  filtered  waters  being  evaporated  at  a  boiling  heat,  discover  flocks  floating  through 
them,  which  have  been  supposed  by  some  to  be  albumen,  and  by  others  gluten.  At  last, 
phosphate  of  lime  precipitates.  When  the  residuum  has  assumed  a  sirupy  consistence  in 
the  cold,  it  is  to  be  mixed  with  alcohol,  in  order  to  dissolve  out  its  sugar.  Cold  water 
bein"  added  to  what  remains,  effects  a  solution  of  the  mucUage,  and  leaves  the  insoluble 
azotized  matter  with  the  pLospnate  of  lime. 

By  this  mode  of  analysis  a  minute  portion  of  resin  may  remain  in  the  gluten  and  in  the 
washin?  water ;  the  gluten  retains  also  a  small  proportion  of  a  fixed  oil,  and  a  volatile 
nrincipfe,  which  may  be  removed  by  alcohol.  If  we  wish  to  procure  the  resin  alone,  we 
inust  first  of  all  treat  the  flour,  well  dried,  with  alcohol. 

When  corn  flour,  poor  in  gluten,  is  to  be  analyzed,  the  dough  must  be  enclosed  in  a 
linen  bag,  kneaded  with  water,  and  washed  in  that  stale. 

In  analyzing  barley -meal  by  the  above  process,  hordeine,  mixed  with  common  starch,  is 
©btained  :  they  may  be  separated  by  boiling  water,  which  dissolves  the  starch,  and  leavei 
Uie  hordeine  under  the  aspect  of  saw-dust. 

Fig.  191  is  the  plan  of  a  London  baker's  oven,  fired  with  coal  fuel. 

Fig.  192  is  the  longitudinal  section. 


a  the  body  of  the  oven ;  b,  the  door ;  c,  the  fire-grate  and  furnace ;  d,  the  smoke 
flue*-  e  the  flue  above  the  door,  to  carry  off  the  steam  and  hot  air,  when  taking  out  the 
break;'/,  recess  below  the  door,  for  receiving  the  dust;  g,  damper  plate  to  shut  off  the 
'flue ;  h,  damper  plate  to  shut  off  smoke  flue,  aAer  the  oven  has  come  to  iu  proper 


the  fire-place  c 
below  the    fur 


heat ;  t,  a  small  ircd  pan  over 
for  heating  water;  k,  ash-pit 
nace. 

Fig.  193  is  the  front  view ;  the  same  letters  re- 
fer to  the  same  objects  in  all  the  figures. 

The  flame  and  burnt  air  of  the  fire  at  c,  sweep 
along  the  bottom  of  the  oven  by  the  right  hand 
side,  are  reflected  from  the  back  to  the  left  hand 
side,  and  thence  escape  by  the  flue  d ;  (see  plan 
fig.  193.)  Whenever  the  oven  has  acquired  the 
proper  degree  of  heat,  the  fire  is  withdrawn,  the 
flues  are  closed  by  the  damper  plates,  and  the  lumps 
of  fermented  dough  are  introduced. 
I  believe  it  may  be  safely  asserted  that  the  art  of  baking  bread,  pastry,  and  confec- 
tionery, is  carried  in  Paris  to  a  pitch  of  refinement  which  it  has  never  reached  in 
London.  I  have  never  seen  here  any  bread  which,  in  flavour,  colour  and  texture, 
rivalled  the  French  pain  de  gruau.  In  fact,  our  corn  monopoly  laws,  till  they  were 
of  late  happil^r  repealed,  prevented  us  from  getting  the  proper  wheat  for  preparing,  at 
a  moderate  price,  the  genuine  semoule  out  of  which  that  bread  is  baked.  Hence,  the 
plebeian  bourgeoii  can  daily  grace  his  table  with  a  more  beautiful  piece  of  bread  than 
the  most  aflSuent  English  nobleman.  The  French  process  of  baking  has  been  recently 
described,  with  some  minuteness,  by  their  distinguished  chemist,  M.  Dumas*  and  it 
merits  to  be  known  in  this  country. 

At  each  operation,  the  workman  (petrisseur)  pours  into  the  kneading  trough  the 
residuary  leaven  of  a  former  kneading,  adding  the  proportion  of  water  which  practice 
enjoins,  and  diffuses  the  leaven  through  it  with  his  hands.  He  then  introduces  into 
the  liquid  mass  the  quantity  of  flour  destined  to  form  the  sponge  {pate).  This  flour 
is  let  down  from  a  chamber  above,  through  a  linen  hose  {manche),  which  may  be  shut 
by  folding  it  up  at  the  end. 

The  workman  now  introduces  the  rest  of  the  flour  by  degrees,  diffusing  and 
mingling  it,  in  a  direction  from  the  right  to  the  left  end  of  the  trough.  When  he  has 
thus  treated  the  whole  mass  successively,  he  repeats  the  same  manipulation  from  left 
to  right  These  operations  require  no  little  art  for  their  dextrous  performance ;  hence 
they  have  the  proper  name  assigned  respectively  to  each,  of  /ravage  and  contre- 
^roioge.  The  workman  next  subjects  the  dough  to  three  different  kinds  of  movement, 
m  the  kneading  process.  He  malaxates  it;  that  is,  works  it  with  his  hands  and 
fingers,  in  order  to  mix  very  exactly  its  component  parts,  while  he  adds  the  requisite 
quantity  of  flour.  He  divides  it  into  six  or  seven  lumps  (pdtons),  each  of  which  he 
works  successively  in  the  same  manner.  Then  he  seizes  portions  of  each,  to  draw 
them  out,  taking  only  as  much  as  he  can  readily  grasp  in  his  hands.  When  he  has 
thus  kneaded  the  different  lumps,  he  unites  them  into  one  mass,  which  he  extends  and 
folds  repeatedly  back  upon  itself  He  then  lifts  up  the  whole  at  several  times,  and 
dashes  it  forcibly  against  the  kneading  trough,  collecting  it  finally  at  its  left  end. 
The  object  of  these  operations  is  to  effect  an  intimate  mixture  of  the  flour,  the  water, 
and  the  leaven.  No  dry  powdery  spots  called  marrons,  should  be  left  in  any  part  of 
the  dougli. 

The  kueader  has  now  completed  his  work ;  and  after  leaving  the  dough  for  some 
time  at  rest^  he  turns  it  upside  down.  He  lays  the  lumps,  of  a  proper  weight,  upon  a 
table,  rolls  them  out^  and  dusts  them  with  a  little  flour.  He  next  turns  over  each 
lump,  and  puts  it  in  its  panneton,  where  he  leaves  it  to  swell.  If  the  flour  be  of  good 
quality,  the  dough  be  well  made,  and  the  temperature  be  suitable,  the  lumps  will 
swell  much  and  uniformly.  If  after  the  surface  has  risen,  it  falls  to  a  considerable 
extenty  the  flour  must  be  bad,  or  it  must  contain  other  substances,  as  potato  starch, 
bean  meal,  <fcc. 

Whenever  the  oven  is  hot  enough,  and  the  dough  suflficiently  fermented,  it  is  sub- 
jected to  the  baking  process.  Ovens,  as  at  present  constructed,  are  not  equally 
heated  throughout,  and  are  particularly  liable  to  be  chilled  near  the  door,  in  conse- 
quence of  its  being  occasionally  opened  and  shut.  To  this  cause  M.  Dumas  ascribes 
many  of  the  defects  of  ordinary  bread;  but  he  adds,  that  by  adopting  the  patent 
invention  of  M.  Mouchot  these  may  be  obviated.  This  is  called  the  improved  bakery, 
boulangerie  perfectionnee. 

Fig.  194.  IS  a  ground  plan  of  the  aerothermal  bake-house,  the  granaries  being  in  the 
upper  stories,  and  not  shown  here.  6  b  are  the  ovens ;  c,  the  kneading  machine  ;  d, 
the  place  where  the  machinery  is  mounted  for  hoisting  up  the  bread  into  the  store 

•  Traits  de  Chimie  appliqu^e  aaz  ArU,  Ti.  p.  400. 
2L2 


;     1 


260 


BREAD. 


BREAD. 


261 


1  n 


room  Above ;  «,  a  space  common  to  the  two  ovena,  into  which  the  hot  air  passes ;  /,  the 
place  of  a  wheel  driven  by  dogs,  for  giving  motion  to  the  kneading  maclune. 


194 


Mg.  195.  is  a  longitudinal  section  of  the  oven ;  A,  the  grate  where  coke  or  even  pit- 
coals  may  be  burned ;  B,  B,  void  spaces  which,  becoming  heated,  serve  for  warmmg 
small  pieces  of  dough  in ;  c,  c  are  flues  for  conducting  the  smoke,  &c.,  from  the  fire- 
place ;  D,  seen  in  Jig.  196.,  is  the  chimney  for  carrying  off  the  euioke  transmitted  by  the 
flues;  E^  E,  void  spaces  immediately  over  the  flues,  and  beneath  the  sole,  F,  F,  of  the 
oven.  By  this  arrangement  the  air,  previously  healed,  which  arrives  from  the  void 
spaces  B  through  the  flues,  c,  c,  gets  the  benefit  of  the  heat  of  the  flame  which  circu- 
lates in  these  flues,  and,  after  getting  more  heated  in  the  spaces  E,  E,  ascends  through 
channels  into  the  oven  F,  F,  upon  the  sole  of  which  the  loaves  to  be  baked  are  laid. 


The  hot  air  is  admitted  into  it  through  the  passages  a,  a,  being  drawn  from  the  reser- 
Toirs  B  B  B  and  also  by  the  passage  d,  d,  drawn  from  the  reservoirs  E,  K  The 
sole  is  likewise  heated  by  contact  with  the  hot  air  contained  in  the  space  E,  E,  placed 
immediately  below  it.  The  hot  air,  loaded  with  moisture,  issues  by  the  passage  6,  6, 
and  returns  directly  into  the  reservoir  B,  B.    G,  G,  an  enclosed  space  directly  over 


the  oven,  to  obstruct  the  dissipation  of  its  heat ;  g,  vault  of  the  fire-place.  Mg.  196.,  a 
transverse  section  through  the  middle  of  the  oven.  Fig.  197.,  the  kneading  machine,  a 
longitudinal  section  passing  through  its  axis ;  P,  P,  the  contour  of  the  machine,  made 


of  wood,  and  divided  into  three  compartments  for  the  reception  of  the  dough.  The 
wooden  bars,  o,  o,  are  so  placed  in  the  interior  of  the  compartments,  as  to  divide  the 
dough  whenever  the  cylinder  is  made  to  revolve.  One  portion,  D,  of  the  cylinder  may 
be  opened  and  laid  over  upon  the  other  by  means  of  a  hinge  joints  when  the  dough  ana 
flour  are  introduced.  A,  B,  C,  the  three  compartments  of  the  machine,  two  for  making 
the  dough,  and  one  for  preparing  the  sponge,  called  levain,  or  leaven,  by  the  French,  a,  a, 
is  the  pulley  which  receives  its  motion  from  the  engine,  and  transmits  it  to  the  cylinder 
through  the  pinion  h,  and  the  spur-wheel  e;  dd,  the  fly-wheel  to  regulate  the  motion ; 
^  a  brake  to  act  upon  the  fly  d,  by  means  of  a  lever  h;  i,  the  pillar  of  the  fly-wheel. 
There  is  a  ratchet  wheel  counter  for  numbering  the  turns  of  the  kneading  machine, 
but  it  cannot  be  shown  in  this  view ;  n,  cross  bars  of  wood,  which  are  easily  removed 
when  the  cylinder  is  opened ;  they  divide  the  dough. 

Each  of  the  three  compartments  of  the  kneader  (Jig.  19*7.)  is  furnished  at  pleasure 
with  two  bars  fixed  crosswise,  but  which  may  be  easily  removed,  whenever  the 
cylinder  is  opened.     These  bars  C(..nstitute  the  sole  agents  for  drawing  oi\t  the  dough. 

197  "I 


In  a  continuous  operation,  the  leaven  is  constantly  prepared  in  the  compartment  A ; 
with  which  view  there  is  put  into  it — 

125  kilogrammes  of  ordinary  leaven  or  yeast. 

67 flour. 

33        ......        water. 

In  all        225  kilogrammes. 
The  person  in  charge  of  the  mechanical  kneader  shuts  down  its  lid,  and  sets  it 


262 


BREAD. 


BREAD. 


263 


a-going.  At  the  end  of  about  seven  minutes  he  hears  the  bell  of  the  counter  sound, 
announcing  that  the  number  of  revolutions  has  been  sufficient  to  call  for  an  inspection 
of  the  sponge,  in  regard  to  its  consistence.  The  cylinder  is  therefore  opened,  and 
after  verifying  the  right  state  of  the  leaven,  and  adding  water  to  soften,  or  flour  to 
stiffen  it,  he  closes  the  lid,  and  sets  the  machine  once  more  in  motion.  In  ten  minutes 
more  the  counter  sounds  again,  and  the  kneading  is  completed.  The  450  kilo- 
grammes of  leaven  obtained  from  the  two  compartments  are  adequate  to  prepare 
dough  enough  to  supply  alternately  each  of  the  two  ovens.  For  this  purpose  75 
kilogrammes  of  leaven  are  taken  from  each  of  the  two  compartments  A  and  A',  and 
placed  in  the  intermediate  compartment  B.  The  whole  leaven  is  then  75-f-75=150 
kilogrammes  ;  to  which  are  added  100  kilogs.  of  flour  and  50  of  water=150,  so  that 
the  chest  contains  300  kilogrammes.  There  is  now  replaced  in  each  of  the  cavities  A 
and  A'  the   primitive    quantity,  by   adding    50    kilogrammes  of   flour  and  25  of 

The  cylinder  is  again  set  a-going  i  and  from  the  nature  of  the  apparatus,  it  is 
obvious  that  the  kneading  takes  place  at  once  on  the  leavens  A  and  A'  and  on  the 
paste  B;  which  last  is  examined  after  7  minutes,  and  completed  in  10  more=17,  at 
the  second  sound  of  the  counter-bell. 

The  kneader  is  opened,  the  paste  on  the  side  and  on  the  bars  is  gathered  to  the 
bottom  by  means  of  a  scraper.  The  whole  paste  of  the  chest  B  being  removed,  150 
kilogs.  of  the  leaven  are  taken,  to  which  150  kilogs.  of  flour  and  water  are  added  to 
prepare  the  300  kilogs.  of  paste  destined  for  the  supply  of  the  oven  No.  2.  These 
75  kilogs.  of  leaven  from  each  compartment  are  replaced  as  before,  and  so  on  in  suc- 
cession. . 

The  water  used  in  this  operation  is  raised  to  the  proper  temperature,  viz.  25  or 
ZQP  C.  (77°  or  86°  F.)  in  cold  weather,  and  to  about  68°  F.  in  the  hot  season,  by 
mixing  common  cold  water  with  the  due  proportion  of  water  maintained  at  the  tem- 
perature of  about  160°  F.,  in  the  basin  F  placed  above  the  ovens. 

Through  the  water  poured  at  each  operation  upon  the  flour  in  the  compartment  B, 
there  is  previously  diffused  from  200  to  250  grammes  of  fresh  leaven,  as  obtained  from 
the  brewery,  after  being   drained   and   pressed   (^German   yeast).    This   quantity  is 
sufficient  to  raise  properly  300  kilogs.  of  dough.     As  soon  as  this  dough  is  taken  out 
of  the  kneader,  as  stated  above,  and  while  the  machine  goes  on  to  work,  the  quantity 
r«i:nisite  for  each  loaf  is  weighed,  turned  about  on  the  table  D,  to  give  it  its  round  or 
oblong  form,  and  there  is  impressed  upon  it  with  the  fore-arm  or  roller,  the  cavity 
which  characterizes  cleft  loaves.     All  the   lots  of  dough  of  the  size  of  one  kilog., 
called  cleft  loaves  (pains  fendus)  are  placed  upon  a  cloth  a  fold  of  which  is  raised 
between  two  loaves,  the  cloth  being  first  spread  upon  a  board ;  which  thus  charged 
with  10  or  15  loaves  is  transferred  to  the  wooden  shelves  G  G  in  front  of  the  oven. 
The  whole  of  them  rise  easily  under  the  influence  of  the  gentle  temperature  of  this  ante- 
chamber or  foumxl.     Whenever  the  dough  loaves  are  sufficiently  raised  here,  they  are 
put  into  the  oven,  a  process  called  enfoumement  in  France ;  which  consists  in  setting 
each  loaf  on  a  wooden  shovel  dusted  with  coarse  flour,  and  placing  it  thereby  on  the 
sole  of  the  oven,  close  to  its  fellow,  without  touching  it.     This  operation  is  made  easy,  in 
consequence  of  the  introduction  of  a  long  jointed  gas-pipe  and  burner  into  the  interior 
of  the  oven,  by  the  light  of  which  all  parts  of  it  may  be  minutely  examined.    The  oven 
is  first  kept  moderately  hot,  by  shutting  the  dampers ;  but  whenever  the  thermometer 
attached  to  it  indicates  a  temperature  of  from  300°  to  290^  C.  (572°  to  554°  F.), 
the  dampers  or  registers  are  opened,  to  restore  the  heat  to  its  original  degree,  by 
allowing  of  the  circulation  of  the  hot  air,  which  rises  from  the  lower  cavities  around 
the  fire-place  into  the  interior  of  the  oven.     When  the  baking  is  completed,  the  gas- 
light, which  had  been  withdrawn,  is  again  introduced  into  the  oven,  and  the  bread  is 
taken  out ;  called  the  process  of  defoumeinent     If  the  temperature  have  been  main- 
tained at  about  SOO^  C,  the  300  kilogs.  of  dough  divided  into  loaves  of  one  kilog. 
(2}  lbs.  avoirdupois)  will  be  baked  in  27  minutes.     The  charging  having  lasted  10 
minutes,  and  the  discharging  as  long,  the  baking  of  each  batch  will  take  up  47  minutes. 
But  on  account  of  accidental  interruptions,  an  hour  may  be  assignerfi  for  each  charge 
of  260  loaves  of  1  kilog.  each ;  being  at  the  rate  of  6240  kilogs.  (or  6-75  tons)  of  bread 
in  24  hours.  .  ., 

Although  the  outer  parts  of  the  loaves  be  exposed  to  the  radiation  of  the  walls, 
heated  to  280°  or  300°  C,  and  undergo  therefore  that  kind  of  caramelization  (charring) 
which  produces  the  colour,  the  taste,  and  the  other  special  characters  of  the  ci-ust,  yet 
the  inner  substance  of  the  loaves,  or  the  crumb,  never  attains  to  nearly  so  high  a  tem- 
perature ;  for  a  thermometer,  whose  bulb  is  inserted  into  the  heart  of  a  loaf,  does  not 
indicate  more  than  100°  C.  (212°  F.>  .  mu     n 

The  theory  of  panijication  (bread-baking)  is  easy  of  comprehension.  The  flour 
owes  this  valuable  quality  to  the  gluten,  which  it  contains  in  greater  abundance  than 


any  of  the  other  cerealia  (kinds  of  corn).  This  substance  does  not  constitute,  as  had 
been  heretofore  imagined,  the  membranes  of  the  tissue  of  the  perisperm  of  the  wheat; 
but  is  enclosed  in  cells  of  that  tissue  under  the  epidermic  coats,  even  to  the  centre  of 
the  grain.  In  this  respect  the  gluten  lies  in  a  situation  analogous  to  that  of  the  starch, 
and  of  most  of  the  immediate  principles  of  vegetables.  The  other  immediate  principles 
which  play  a  part  in  panificaiion  are  particularly  the  starch  and  the  sugar ;  and  they 
all  operate  as  follows  : — 

The  diffusion  of  the  flour  through  the  water,  hydrates  the  starch  and  dissolves  the 
sugar,  the  albumen,  and  some  other  soluble  matters.  The  kneading  of  the  dough,  by 
completing  these  reactions  through  a  more  intimate  union,  favors  also  the  fermen- 
tation of  the  sugar,  by  bringing  its  particles  into  close  contact  with  those  of  the 
leaven  or  yeast ;  and  the  drawing  out  and  malaxating  the  dough  softens  and  stratifies  it, 
introducing  at  the  same  time  oxygen  to  aid  the  fermentation.  The  dough,  when 
distributed  and  formed  into  loaves,  is  kept  some  time  in  a  gentle  warmth,  in  the  folds 
of  the  cloth,  pans,  &c.,  a  circumstance  propitious  to  the  development  of  their  volume 
by  fermentation.  The  dimensions  of  all  the  lumps  of  dough  now  gradually  enlarge, 
from  the  disengagement  of  carbonic  acid  in  the  decomposition  of  the  sugar ;  which  gas 
is  imprisoned  by  the  glutinous  paste.  Were  these  phenomena  to  continue  too  long, 
the  dough  would  become  too  vesicular ;  they  must,  therefore,  be  stopped  at  the  proper 
point  of  sponginess,  by  placing  the  loaf  lumps  in  the  oven.  Though  this  causes  a 
sndden  expansion  of  the  enclosed  gaseous  globules,  it  puts  an  end  to  the  fermentation, 
and  to  their  growth  ;  as  also  evaporates  a  portion  of  the  water. 

The  fermentation  of  a  small  dose  of  sugar  is,  therefore,  essential  to  true  bread- 
baking  ;  but  the  quantity  actually  fermented  is  so  small  as  to  be  almost  inappreciable. 
It  seems  probable  that  in  well-made  dough  the  whole  carbonic  acid  that  is  generated 
remains  in  it;  amounting  to  one  half  the  volume  of  the  loaf  itself  at  its  baking  tempera- 
ture, or  212°.  It  thence  results  that  less  than  one  hundredth  part  of  the  weight  of  the 
flour  is  all  the  sugar  requisite  to  produce  well-raised  bread.  What  egregious  folly  was 
it,  therefore,  to  mount  the  bakery  in  Chelsea,  twelve  years  ago,  at  an  expense  of  20,000Z., 
for  the  purpose  of  catching  the  volatile  spirits  in  their  escape  from  the  loaves  in  the 
oven — or,  as  it  was  vulgarly  termed,  "  taking  the  gin  out  of  the  bread !"  whereas  it  was 
nothing  but  taking  the  cash  out  of  the  pockets  of  the  pseudo-chemical  visionaries  who 
swarm  in  this  metropolis. 

The  richness  or  nutritive  powers  of  sound  flour  and  also  of  bread  are  proportional  to 
the  quantity  of  gluten  they  contain.  It  is  of  great  importance  to  determine  this  point, 
for  both  of  these  objects  are  of  enormous  value  and  consumption ;  and  it  may  be  accom- 
plished most  easily  and  exactly  by  digesting  in  a  water-bath,  at  the  temperature  of  167* 
F.,  1,000  grains  of  bread  (or  flour)  with  1,000  grains  of  bruised  barley-malt,  in  5,000 
grains,  or  in  a  little  more  than  half  a  pint,  of  water.  When  this  mixture  ceases  to  take 
a  blue  color  from  iodine  (that  is,  when  all  the  starch  is  converted  into  soluble  dextrine^ 
the  gluten  left  unchanged  may  be  collected  on  a  filter  cloth,  washed,  dried  at  a  heat  of 
212^,  and  wei?hed.  The  color,  texture,  and  taste  of  the  gluten,  ought  also  to  be  ex- 
amined, in  forming  a  judgment  of  good  flour,  or  bread. 

Independently  of  the  skill  of  the  baker,  bread  varies  in  quality  according  to  the 
quantity  of  water  and  gluten  it  contains.  A  patent  of  German  or  French  origin  was 
obtained  here  a  few  years  ago,  for  manufacturing  loaf-bread  by  using  thin  boiW  floor. 
paste  instead  of  water  for  setting  the  sponge,  that  is,  for  the  preliminary  dough  fermen- 
tation. By  this  artifice,  104  loaves  of  4  lbs.  each  could  be  made  out  of  a  sack  of  flour, 
instead  of  94,  as  in  ordinary  baking ;  because  the  boiled  paste  gave  a  water-keeping 
faculty  to  the  bread  in  that  proportion.  But  this  hijdrated  bread  was  apt  to  spoil  in 
warm  weather,  and  became  an  unprofitable  speculation  to  all  concerned. 

Bread  and  flour  are  often  adulterated  in  France  with  potato  starch,  but  almost  never, 
I  believe,  in  this  country.  The  sophistication  is  easily  detected  by  the  microscope,  on 
account  of  the  peculiar  ovoid  shape  and  the  large  size  of  the  particles  of  the  potato 
fecula.  Horse-bean  flour  gives  to  wheaten  bread  a  pinkish  tint  In  spoiled  flour 
(such  as  is  too  often  used,  partially  at  least,  by  our  inferior  bakers)  the  gluten  some- 
times disappears  altogether,  and  is  replaced  by  ammoniacal  salts.*  In  this  case  quick- 
lime separates  ammonia  from  the  flour  without  heat;  in  flour  slightly  damaged,  or 
ground  from  damaged  wheat,  the  gluten  present  is  deprived  of  its  elasticity,  and  is 
softer  than  in  the  natural  state.  On  this  account  the  gluten  test  of  M.  I3oland  is 
valuable.  It  consists  in  putting  some  gluten  into  the  bottom  of  a  copper  tube,  and 
heating  that  tube  in  an  oven,  or  in  oil  at  a  temperature  of  284°  F.  The  length  to 
which  the  cylinder  of  gluten  expands  is  proportional  to  and  indicates  its  quality. 

It  appears  that  a  French  sack  of  flour,  which  weighs  159  kilogrammes,  aftbrds  from 
102  to  106  loaves  of  2  kilogrammes  each  :    and  therefore, 

159  .  62-0  ::  280  :  9 16;  tliat  is,  if  169  kilogs.  or  lbs.  afford  62  loaves  of  4  kilogs. 
or  lbs.,  280  lbs.,  a  sack  English,  should  afford  9 1  6  loaves  of  4  lbs.  each;   but  our 

*  Dumas,  Chimie  Appliquee,  vi.  425. 


,     \ 


1 


)l 


m  r 


264 


BREWING. 


bakers  usually  make  out  94  loaves,  which  are  rated  at  4  pounds,  though  they  seldom 
weigh  so  mucn.  The  loaves  of  a  baker  in  my  neighbourhood,  who  supplied  my  family 
with  bread  for  some  time,  were  found  on  trial  to  be  from  6  to  8  oz.  deficient  in  weight : 
when  challenged  for  this  fraud,  he  had  the  effrontery  to  palliate  it  by  alleging  that  all 
his  neighbour  bakers  did  the  same.  It  must  be  borne  in  mind  that  a  Paris  loaf  of  2  lbs. 
or  2  kilogs.  contains  more  dry  farina  than  a  London  loaf  of  like  weight ;  for  it  contains, 
from  its  form  and  texture,  more  crust.  The  crumb  is  to  the  crust  in  the  Paris  long 
loaves,  as  25  to  75,  or  1  to  3 ;  in  our  quartern  loaves  it  is  as  18  or  20  to  100. 
M.  Dumas  gives  the  following  Table  : — 


Weight  of  a 
Sack  of  Flour. 

Number  of 
Loaves. 

Weight  of  the 
Bread. 

Increase  of 
Weight  of  Flour. 

Ratio  of  dry  Flour 
—  1.  to  Bread. 

159  Kilogs. 
159      do. 
169      do. 

102 
104 
106 

202  Kilogs. 
208      do. 
212      do. 

1-283 
1-300 
1-333 

1 :  1-60 

Thus  it  would  appear  that  the  mean  yield  would  correspond  to  130  kilogs.  of  bread 
for  100  of  the  flour  employed:  and  admitting  that  common  flour  contains  0-17  of 
water,  the  product  would  be  equivalent  to  150  of  bread  for  100  of  flour  absolutely  dry. 
The  whole  loaf  contains  66  per  cent,  of  dry  substance,  and  the  crumb  only  44. 

BRECCIA,  an  Italian  term,  used  by  mineralogists  and  architects  to  designate  such 
compound  stony  masses,  natural  or  artificial,  as  consist  of  hard  rocky  fragments  of 
considerable  size,  united  by  a  common  cement.  "When  these  masses  are  foi-med  of 
small  rounded  pebbles,  the  conglomerate  is  called  a  pudding-stone,  from  a  fancied 
resemblance  to  plum  pudding. 

Concrete,  now  so  much  used  for  the  foundation  of  large  buildings,  is  a  factitious 
breccia,  or  pudding-stone.     See  Concrete. 

BREWING.     {Brasser,  Fr. ;  Brauen,  GeroL)    The  art  of  making  Beer,  which  see. 

The  peculiar  properties  contained  in  wort,  do  not  exist  ready  formed  in  malt,  but  are 
the  result  of  the  direct  action  of  heat  and  water  upon  that  substance.  Hence  it  follows 
that  the  composition  of  beer-wort  depends  more  upon  the  process  of  mashing  than  upon 
the  malt  employed, — for  it  would  be  quite  practicable  to  obtain  from  1  part  of  malt 
and  8  parts  of  barley,  a  wort  precisely  similar  to  that  procured  from  9  parts  of 
pure  malt  alone.  But,  of  course,  this  could  not  be  done  without  modifying  consi- 
derably the  process  of  mashing ;  and  it  happens,  unfortunately,  that  the  practice  of  the 
present  day,  amongst  brewers,  is  to  maintain,  as  closely  as  possible,  one  uniform  system 
of  mashing,  whatever  may  be  the  nature  or  quality  of  the  malt  employed.  Thus  a 
difference  in  the  malt  is  made  to  produce  a  difference  in  the  wort,  and  all  the  energy 
and  skill  of  the  practical  brewer  are  sometimes  insuflScient  to  compensate  for  the  alter- 
ations which  this  difi'erence  induces  in  the  subsequent  working  of  the  beer.  With  a 
regular  and  certain  composition,  as  to  the  constituents  of  his  wort,  the  operations  of 
the  brewer  would  assume  a  fixed  and  definite  character,  which,  at  present,  they  are  very 
far  indeed  from  possessing ;  and  by  which  he  not  unfrequently  suffers  the  most  severe 
pecuniary  loss  and  mental  anxiety.  "With  the  exception  of  a  trifling  quantity  of  vege- 
table albumen,  the  only  solid  ingredients  of  beer-wort  are  dextrine  and  sugar;  the 
latter  of  which  ferments  with  great  ease  and  rapidity,  whilst  the  dextrine,  though 
capable  of  fermentation,  enters  into  the  process  only  with  difficulty,  and  requires,  for 
its  suocessful  termination,  not  only  much  more  yeast,  but  also  a  much  higher  temperature 
in  the  fermenting  fat.  At  the  same  time,  it  is  this  very  sluggishness  in  the  fermentative 
quality  of  dextrine  which  is  essential  to  the  production  of  good  beer ;  for,  with  sugar 
alone,  the  fermentation  cannot  be  checked  at  ordinary  temperatures,  until  the  full 
measure  of  its  decomposition  has  taken  place,  and  it  has  become  either  a  vapid  admixture 
of  alcohol  and  water,  or,  by  the  absorption  of  oxygen,  is  resolved  into  vinegar.  It  is 
indeed  a  notorious  fact,  that  beer  made  with  sugar  will  not  keep  so  well  as  that  made 
from  malt ;  though,  for  rapid  consumption,  the  use  of  sugar  is,  under  some  circumstances, 
to  be  commended,  more  especially  on  the  small  scale  and  in  cold  weather.  The  pecu- 
liarity of  dextrine  is,  however,  as  we  have  stated,  to  undergo  fermentation  only  with 
difficulty  and  by  slow  degrees ;  hence  its  decomposition  spreads  over  a  long  space  of 
time,  and,  in  very  cold  weather,  amounts  to  nothing ;  so  that  for  months,  or  even  years, 
after  all  the  sugar  of  the  wort  has  been  destroyed,  the  evolution  of  carbonic  acid  gas 
from  the  still  fermenting  dextrine,  keeps  up  a  briskness  and  vitality  in  the  beer ;  and, 
by  excluding  oxygen,  all  chance  of  acidification  is  shut  off.  A  perfect  beer-wort  should 
therefore  have  reference  to  the  period  of  its  consumption :  if  this  be  speedy  and  pressing, 
the  proportion  of  sugar  ought  to  be  large ;  if  remote,  the  dextrine  should  greatly  pre- 
dominate. Under  the  first  condition,  the  attenuation  would  proceed  quickly,  and, 
provided  the  temperature  of  the  fermenting  vat  was  not  allowed  to  exceed  78°,  the  beer 
would  soon  cleanse  and  become  ripe  and  bright ;  under  the  second,  the  attenuation  in 


BREWING. 


265 


the  vat  would  be  slow  and  trifling,  and  require,  perhaps,  several  years  for  its  completion 
in  the  cask.  Nevertheless,  if  the  attenuation  in  the  vat  had  gone  on  to  the  complete 
destruction  of  all  the  sugar,  this  kind  of  beer  would  prove  in  the  end  both  the  better  and 
more  healthy  beverage  of  the  two ;  for  by  the  mode  of  its  formation  the  presence  of 
senanthic  ether  or  fusel  oil  is  avoided.  The  importance  therefore  of  placing  in  the 
hands  of  the  brewer  a  means  of  determining  the  relative  amounts  of  sugar  and  dextrine 
in  his  wort  is  sufficiently  obvious.  Now,  this  may  be  done  in  two  ways ;  either  by 
ascertaining,  in  wort  of  a  determinate  strength,  the  proportion  of  the  one  or  the  other  of 
these  substances.  The  dextrine  is  easier  of  calculation  than  the  sugar,  in  a  rough  or 
approximate  way ;  but  the  sugar  can  be  determined  with  much  more  minute  accuracy 
than  the  dextrine.  Yet,  in  practice,  the  former  plan  is  preferable,  from  its  simplicity, 
as  we  shall  proceed  to  show.  I^  to  a  certain  volume  of  strong  wort  (say  of  30  lbs.  per 
barrel),  we  add  an  equal  amount  of  alcohol  or  spirits  of  wine,  the  whole  of  the  dextrine 
will  precipitate  as  a  dense  coagulum ;  and  by  examining  the  bulk  of  this  deposit  in  the 
tnbe,  its  weight  may  be  inferred  pretty  nearly  if  the  tube  has  been  previously  graduated 
so  as  to  indicate,  from  actual  experiment,  the  weight  of  the  difterent  measures  of  the 
coagulated  dextrine.  "With  weaker  wort,  more  alcohol  must  be  used,  and  with  a  denser 
wort,  less  alcohol, — the  relations  of  which  to  each  other  may  easily  be  kept  recorded  on 
a  small  card  or  scale  affixed  to  the  tube.  This  instrument  is  very  easy  of  application, 
and  has  been  found  extremely  useful  to  more  than  one  practical  brewer  of  the  present 
day ;  and  the  accompanying  record  of  brewing  operations  has  reference  to  this  mode  of 
analysing  wort.  The  determination  of  sugar  in  wort  is  best  effected  by  boiling  100  grs. 
of  it  with  about  half  a  pint  of  the  following  solution,  and  collecting  and  weighing  the 
red-coloured  precipitate  which  ensues, — every  three  grains  of  which  indicate  one  grain 
of  grape-sugar  in  the  wort. 

Grape-sugar  Test  Solution, 
Sulphate  of  copper  in  crystals        .  -  -  -         100  grains 

Bitartrate  of  potash  -  -  -  -  -        200     do 

Carbonate  of  soda  in  crystals         -  -  -  -        soo    do 

Boiling  water,  one  pint,  or  -  -  -  -      8750    do 

First  dissolve  the  sulphate  of  copper,  then  the  bitartrate  of  potash,  after  which  add 
the  carbonate  of  soda,  and  filter  if  necessary.  This  solution  is  not  affected  when  boiled 
with  cane-sugar,  dextrine,  gum,  or  starch. 

We  now  proceed  to  lay  before  our  readers  the  result  of  two  brewings  taken  from  one 
mash  at  two  diflferent  periods,  and  analyzed  to  determine  their  relative  contents  of  dex- 
trine and  sugar,  according  to  the  tube  or  alcohol  process: — March  28th,  1851,  proceeded 
to  mash  for  experimental  brewings ;  weather  clear  and  open ;  thermometer  outside  at  51°, 
— in  fei-menting  room  68* ;  difference  between  wet  and  dry  bulb  5-750° ;  barometer 
89-4  inches.  Composition  of  the  malt : — Moisture  6-1  ;  insoluble  matter  27 ;  extract 
66-9.  Quantity  of  malt  employed  70  bushels;  of  water  at  180°  F.,  700  gallons; 
made  the  mixture  with  a  common  mashing-oar,  and  finished  in  fifteen  minutes.  One  hour 
afterwards,  drew  off  200  gallons  of  wort ;  and  three  hours  from  commencing  to  mash, 
drew  off  200  gallons  more, — continuing  the  mash  for  table-beer-wort  The  first-drawn 
wort  contained  7-5  parts  of  dextrine  to  1  of  sugar;  the  second,  6-3  parts  of  dextrine 
2*2  of  sugar; — their  densities  were,  respectively,  30  and  36*5  lbs.  per  barrel.  They 
were  each  boiled  separately,  with  relative  amount  of  hop, — the  first  having  30  and  the 
second  36^^  lbs.  added ;  and  the  boiling  in  each  case  was  kept  up  for  three  hours.  At 
the  end  of  this  time  both  were  cooled  and  diluted  with  water  to  a  gravity  of  27^  lbs.  per 
barrel,  and  250  gallons  of  each  let  down  into  separate  fermenting-vats  placed  side  by 
side ;  after  which,  they  both  received  three  quarts  of  good  yeast, — the  temperature 
being  at  68°  F.  Two  hours  afterwards,  the  following  observations  commenced  : — No. 
1.  being  the  wort  containing  7*6  pai-ts  of  dextrine  to  1  of  sugar,  and  No.  2.  the  wort 
having  6-3  of  dextrine  to  2-2  of  sugar. 


1851. 

March  28.  5  p, 
"        "  10  p, 


M. 

P.  M. 

^«7«    tf  A*  Ja* 

*•     6  P.  M. 

V    A*  JA* 

6  P.  M. 

2  P.  M. 


80. 


f 


VouL 


81. 


ril  2.  2  p.  M. 
11.  2  p.  M. 
13.  2  P.  M. 


No.  1. 
No  action 
Light  thin  cream 
White  head 
Fine  white  head 
Thick  tough  head    - 
Tough  brown  head  - 
Ferment  well  roused  up 

Attenuation  of  No.  1. 
(Skimmed  oflf  yeast) 


2M 


Temp. 
67-5 
67-5 
70- 
IV 
74- 
76- 
76- 

Deg. 

8i 
10- 
16- 
16-6 


266 


BREWING. 


No.  2. 
No  action  .... 

Fine  white  head  .  .  - 

Thick  yellow  head        -  .  - 

Fine  tough  brown  head 
High  roused  up  rocky  head 
In  rapid  fermentation  -  -  - 

Throws  up  much  yeast  (skimmed  off  yeast) 
Ditto  of  No.  2.  ... 


m 


n 
n 


Deg 

68- 
10' 

-  1A' 

-  11' 

-  11' 
76-6 
76- 
12-7 
16-6 
17-6 

»».-....        18-2 

The  temperature  of  both  had  now  fallen  to  69*  F.,  though  each  had  been  roused  re- 
peatedly ;  the  yeast  was,  therefore,  again  skimmed  off,  and  the  beer  run  into  barrels,  and 
filled  up  with  reserved  wort  three  times  a  day  as  it  worked  over.  On  April  the  18th 
the  barrels  were  closed,  having  then  lost,  by  attenuation, — No.  1.  16'2  lbs.,  and  No.  2. 
19'6  lbs.  Six  weeks  afterwards  these  ales  were  examined ; — No  1.  was  found  muddy 
and  unpleasant ;  whilst  No,  2.  had  a  fine  fragrant  aroma,  a  brisk,  lively  appearance,  and 
was  perfectly  bright.  On  January  2nd,  1852,  the  casks  were  again  examined;  No.  1. 
had  now  lost  17*9  lbs.,  and  was  bright,  rich,  and  fine  flavoured ;  whilst  N.  2.,  though 
bright  and  pleasant,  had  contracted  a  little  acidity,  and  was  becoming  flat ;  it  had  lost, 
in  all,  21i  lbs. 

Two  similar  experiments,  made  about  the  same  time  in  another  quarter,  gave  almost 
exactly  the  same  results ;  and,  consequently,  there  can  be  little  doubt  that,  where  a  quick 
sale  and  rapid  consumption  of  beer  can  be  ensured,  the  great  object  of  the  brewer  should 
be  to  convert  as  much  of  the  dextrine  of  his  wort  into  sugar  as  is  proportional  to  the 
rapidity  of  that  consumption ;  whereas,  for  beer  intended  to  keep,  the  opposite  practice 
should  be  followed. 

The  conversion  of  any  given  amount  of  the  dextrine  wort  into  sugar  may  be  effected 
either  by  keeping  up  the  temperature  of  the  mash-tun,  and  prolonging  the  operation  of 
mashing:  or,  which  is  better  and  simpler,  by  merely  preserving  the  wort  for  a  few  houra 
at  a  heat  of  170'  F.,  either  in  the  underback  or  any  other  convenient  vessel.  We  have 
found  from  experiment  that  a  wort  which  when  run  out  from  the  mash-tun  had  only  3 
parts  of  sugar  to  16  of  dextrine,  became  by  10  hours'  exposure  to  a  heat  of  165*  con- 
verted almost  altogether  into  sugar, — the  proportions  then  being  17 '8  of  sugar  to  1'2 
of  dextrine. 

A  very  important  part  of  the  duty  of  a  brewer  should  therefore  be,  first,  the  deter- 
mination of  the  relative  amounts  of  dextrine  and  sugar  required  to  suit  the  taste  of  his 
customers,  or  the  circumstances  of  the  market,  and  next,  the  continued  careful  examin- 
ation of  his  wort,  so  as  to  insure  that  these  proportions  are  regularly  maintained ;  for 
by  no  other  plan  is  it  possible  to  insure  that  certamty  of  result,  and  uniformity  of  quality 
which  are  essential  to  the  proper  conducting  of  an  expensive  business  like  brewing.  It 
seems  to  us  that  far  too  little  attention  has  hitherto  been  given  to  the  fluctuating  quali- 
ties of  beer-wort  In  warm  weather,  this  wort  should  probably  contain  at  least  twice  as 
much  dextrine  as  in  winter ;  yet  this  is  the  very  period  when  from  the  increased  tem- 
perature of  the  air  and  materials,  the  largest  quantity  of  sugar  must  be  formed  by  those 
who  mash  upon  a  fixed  and  unvarying  principle.  llence  the  proneness  of  the  wort  to 
ferment  violently  in  summer  is  still  further  increased  by  the  presence  of  an  extra  pro- 
portion of  sugar ; — whereas  prudence  would  suggest,  under  such  circumstances,  a  pre- 
dominance of  dextrine,  and  seek  to  effect  this  purpose  by  a  low  temperature  in  the 
mash-tun,  and  by  shortening  the  period  of  mashing.  We  are  not,  however,  aware  that 
this  custom  prevails,  except  in  one  or  two  solitary  instances,  in  the  north  of  England, 
where  it  is  well  appreciated.  As  a  general  rule,  in  the  management  of  wort,  more 
sugar  is  requisite  where  small  quantities  are  brewed  at  a  time,  than  where  large  opera- 
tions are  conducted,  for  the  loss  of  heat  is  relatively  larger  in  small  masses  than  in 
large  ones;  and,  from  what  has  been  stated,  it  must  be  apparent,  that,  as  the  fermen- 
tation of  dextrine  is  more  easily  checked  by  cold  than  that  of  sugar,  the  beer  brewed 
in  trifling  quantities  could  not  preserve  a  fermentative  temperature,  but  would  become 
chilled  and  dead  from  the  excessive  radiation  of  caloric,  unless  a  principle  existed  in  it 
capable  of  fermentation  at  the  most  ordinary  temperatures  of  this  country.  I^  there- 
fore, beer-wort  consisting  chiefly  of  dextrine  be  fermented  in  very  cold  weather,  or  with 
an  insufficiency  of  yeast,  or  if  the  temperature  happen  to  rise  too  high,  so  as  to  destroy 
or  impair  the  fermentative  power  of  the  yeast,  then  a  dull  languid  action  will  ensue, 
accompanied  by  what  has  been  called  the  viscous  fermentation,  and  the  beer  becomes 
permanently  ropy,  and  is  spoiled. 

Although,  clearly,  it  would  be  impossible  to  lay  down  any  specific  rule  for  the  proper 
proportion  of  dextrine  and  sugar  in  beer-wort,  yet  there  could  be  no  difficulty  in  each 


BREWING. 


267 


brewer  determining  for  himself^  and  for  the  conditions  of  size,  time  of  sale,  time  of  year, 
and  other  contingencies,  the  requisite  ratio  to  be  established  in  his  own  ease ;  and,  as  we 
have  shown,  nothing  can  be  simpler  than  the  means  proposed  for  ascertaining  the  com- 
position of  wort. 

The  advance  of  the  arts  is  gradually  assuming  a  character  which  will  no  longer 
permit  any  manufacturer  to  neglect  the  assistance  of  science ;  and  those  who  first  take 
advantage  of  the  power  of  knowledge,  will  assuredly  leave  their  fellow-labourers  behind. 
From  being  an  uncertain  and  hazardous  operation,  brewing  must  ere  long  become  a 
fixed  and  definite  principle  based  upon  facts  well  understood,  and  capable  of  perpetual  re- 
petition and  reproduction  at  will.  To  sum  up  briefly  the  general  details  of  ale  brewing, 
we  may  state,  that,  for  most  kinds  of  ale,  the  attenuation  in  the  first  instance  should  be 
finished  in  from  6  to  21  days,  according  to  the  strength  of  the  wort ;  that  this  attenua- 
tion should  approach  to  two-thirds  of  the  whole  weight ;  and  that  after  tunning  and 
cleansing,  the  ale  itself  should  weigh  about  one-fourth  of  the  original  gravity  of  the 
wort.  Thus,  if  the  fermenting  tun  be  set  with  wort  of  27  lbs.,  then  the  attenuation 
should  bring  it  down  to  9  or  10  lbs.,  and  the  subsequent  operations  produce  an  ale 
weighing  from  6  to  7  lbs.  When  these  conditions  are  fulfilled,  without  much  extra 
trouble  or  attention,  the  ale  is  pretty  certain  to  turn  out  well,  though,  in  some  localities, 
ale  is  never  attenuated  to  more  than  one-half  its  original  gravity;  this  kind  of  ale  is, 
however,  very  apt  to  become  sour  in  hot  weather  and  ropy  in  cold. 

We  will  now  proceed  to  describe  the  brewing  of  porter,  which  differs  from  that  of 
ale  both  in  the  nature  of  the  materials  used  and  in  the  mode  of  finishing  the  ferment- 
ation. Porter  owes  its  peculiar  colour  and  flavour  to  burnt  saccharine  or  starchy  mat- 
ter ;  and  this  was  formerly  obtained  by  burning  sugar  until  it  exhaled  the  odour  called 
by  French  writers  "  caramel."  At  present,  however,  nothing  but  highly-torrefied  malt 
is  used ;  and  of  this  there  are  several  kinds,  as  brown  malt,  imperial  malt,  and  black 
malt ;  all  of  which  are  used  by  some  brewere,  whilst  others  employ  only  the  brown  and 
black,  and  a  few  the  black  alone,  for  giving  colour  and  flavour.  The  fermentative 
quality  is  saccharine,  is,  however,  the  same  as  that  of  ale,  and  is  derived  from  pale  or 
Amber  malt.  As  a  general  rule,  the  ratio  of  the  colouring  and  flavouring  malts  are  to 
the  saccharine,  as  about  1  to  5,  or  1  to  4 ;  but  where  black  malt  only  is  used,  the  pro- 
portion does  not  exceed  1  to  10. 

The  employment  of  these  burnt  malts  permits  a  singular  act  of  injustice  on  the  part 
of  the  Excise,  as  regards  the  drawback  on  exportation.  By  the  Excise  regulations,  it 
is  assumed  that  a  quarter  of  malt  will  produce  four  barrels  of  ale  brewed  from  wort  of 
the  sp.  gr.  1054,  or  19*4  lbs.  per  barrel;  but,  although  this  is  hopeless  even  with  pale 
malt,  yet  with  an  admixture  of  brown  and  black  malt  the  assumption  becomes  absurd 
in  the  extreme.  Admitting  that,  by  good  management,  on  the  average,  four  barrels  of 
wort,  weighing  20  lbs.,  can  be  obtained  from  one  quarter  of  fine  pale  malt,  yet  in  the 
operations  of  cooling,  fermenting,  tunning,  skimming,  and  cleansing,  a  loss  of  fully  10 
per  cent,  occurs  under  the  most  vigilant  superintendence ;  and,  taking  the  great  bulk 
of  our  metropolitan  breweries,  it  would  be  nearer  the  truth  to  estimate  this  loss  at  12 
per  cent  In  plain  words,  100  gallons  of  wort  will  not,  by  any  management,  produce 
more  than  about  88  gallons  of  saleable  beer,  though  no  allowance  is  made  for  this  by 
the  Excise ;  and  the  brewer  who  has  paid  duty  upon  100  gallons  gets  a  drawback  upon 
but  88.  This,  however,  is  the  most  favourable  view  of  the  case ;  and  we  solicit  atten- 
tion to  the  force  with  which  the  argument  returns  in  the  instance  of  porter. 

If  a  quarter  of  pale  malt  be  assumed  at  84  lbs.  of  saccharine  strength,  then  such  an 
admixture  of  brown  and  black  malt  as  is  usually  employed  by  brewers  of  porter,  will  not 
give  more  than  about  24  lbs. ;  and  as  this  constitutes  at  least  one-fifth  of  the  whole  bulk 
used  in  porter  brewing,  we  see  that  a  quarter  of  such  mixed  malt  can  never  give  more 
than  70  lbs. ;  that  is  to  say,  80  parts  of  pale  malt,  mixed  with  20  of  brown  and  black, 
instead  of  giving  at  the  rate  of  84  lbs.,  as  pale  malt  alone  does,  would  give  but  70  lbs., 
or  produce  a  difference  between  the  actual  return  and  that  taken  for  granted  by  the  Ex- 
cise authorities,  of  no  less  than  166  per  cent;  to  which,  if  we  add  the  loss  previously 
mentioned  as  arising  from  fermentation,  yeast,  <fec.,  and  which  we  have  called  12  per 
cent,  a  total  difference  ensues  of  28'6  per  cent  between  the  duty  paid  by  the  brewer 
and  the  drawback  allowed  by  act  of  parliament.  But  the  grievance  does  not  stop  here ; 
for  the  only  return  allowed  by  act  of  parliament  is  based  upon  the  malt  duty,  and 
nothing  whatever  is  said  of  the  duty  on  hops.  This,  however,  is  at  the  rate  of  19«.  7d. 
per  cwt ;  and  since  hops  yield  only  about  35  per  cent,  of  their  weight  of  soluble  mat- 
ter, it  would  require  168  lbs.  of  hops  to  produce  a  barrel  of  fluid  or  wort  weighing  19*4 
lbs.,  or  having  the  requisite  parliamentary  specific  gravity  of  1'054.  Upon  this  barrel, 
when  exported,  the  drawback  is  6«. ;  but  as  may  easily  be  seen,  on  calculation,  the  duty 
paid  by  the  brewer  has  been  29«.  Sd.  In  fact,  upon  every  168  lbs.  of  hops  consumed 
by  the  export  brewer,  he  suffers  a  dead  loss  of  24«.  Set,  independently  of  the  waste 
incidental  to  his  various  processes.     These  things  may  seem  startling,  yet  I  challenge 

2M2 


_i 


268 


BREWING. 


the  whole  Board  and  StaflF  of  the  Excise  to  prove  that  they  are  in  the  least  over-esti- 
mated. At  the  same  time  the  intelligent  reader  will  gather  that  the  profits  of  brewing 
are  not  by  any  means  so  large  as  a  cursory  glance  at  the  subject  might  warrant ;  and 
we  say  this  rather  as  having  reference  to  schemes  now  in  progress  for  reducing  the 
price  of  beer,  than  from  its  connection  with  our  general  arrangements.  No  doubt  the 
brewing  business  has  been  of  late  singularly  prosperous ;  and  if  the  price  of  malt  con 
tinaes  as  low  this  year  as  it  was  last,  the  public  have  a  right  to  look  for  some  reduction 
in  the  price  of  ale  and  porter ;  but  it  must  not  be  foi^otten  that  the  capital  required  is 
large,  and  invested  in  very  perishable  materials,  such  as  casks  and  other  wooden  uten- 
sils, the  wear  and  tear  upon  which  is  a  very  large  item ;  nor  again,  as  we  have  shown, 
must  a  speculator  begin  by  assuming,  with  the  Excise  authorities,  that  a  quarter  ot 
malt  will  produce  four  barrels  of  beer,  for  he  will  be  much  nearer  the  truth  if  he  esti- 
mates his  saleable  produce  at  three  barrels.  As,  however,  it  forms  no  part  of  our 
present  task  to  enter  into  the  financial  statistics  of  brewing,  we  return  to  the  object 
more  immediately  in  view,  merely  throwing  out,  en  passant,  the  above  hints  for  the 
benefit  of  those  whom  they  may  concern. 

If  the  analyses  of  malt  and  malt- wort  are  requisite  to  enable  the  brewer  to  perform 
his  operations  with  safety  and  success,  the  anal^'sis  of  beer  is  not  less  indispensable  to 
qualify  him  for  the  harassing  labour  of  competition  with  his  neighbours,  and  for  the 
protection  of  his  interest  against  Excise  confiscation.  Although  beer  may  have  been 
brewed  of  the  requisite  gravity  for  justifying  a  drawback  on  exportation,  yet  this  is 
very  far  indeed  from  ensuring  a  return  of  the  malt  duty,  even  to  the  limited  extent 
awarded  by  law.  The  question  is,  how  are  the  Kxcise  officials  to  know  the  real  weight 
of  the  wort  from  which  the  beer  was  brewed.  This  may  be  ascertained  by  the  follow- 
ing method,  which  should  take  the  place  of  the  present  indefinite  83'stem : — Having  agi- 
tated a  portion  of  the  ale  or  beer,  so  as  to  dissipate  its  carbonic  acid  gas,  measure  out 
exactly  3600  grain  measures  of  it,  and  pour  these  into  a  retort ;  then  distil,  with  great 
care,  into  a  receiver,  surrounded  by  ice-cold  water,  about  one-third  of  the  whole  fiuid, 
or  rather  more  than  this  if  the  ale  or  beer  is  known  to  be  highly  alcoholic.  Next  weigh 
the  distilled  fluid,  and  then  ascertain  its  specific  gravity ;  from  whence,  by  any  of  the 
proper  tables  of  alcohol  (which  see),  the  total  quantity  of  absolute  alcohol  in  the  dis- 
tilled fluid  may  be  known.  This  alcohol  is  to  be  converted,  by  calculation,  into  its 
equivalent  of  sugar,  at  the  rate  of  171  parts  of  sugar  for  every  92  of  alcohol  found; 
after  which,  this  sugar  must  be  brought  into  pounds  per  barrel, "by  the  rule  given  in  our 
article  Beer,  which  is  62i  lbs.  of  sugar  for  every  20  lbs.  of  gravity.  The  amount  of 
vinegar  is  next  to  be  determined,  by  any  of  the  known  forms  of  alkalimetry.  (See 
Acetic  Acid.)  This  vinegar  or  acetic  acid,  must,  like  the  alcohol,  be  also  converted  into 
its  representative  of  sugar,  bj  assigning  171  of  sugar  to  every  102  of  anhydrous  acetic 
acid  present  in  the  beer, — this  sugar  being,  as  before,  converted  into  pounds  per  barrel. 
To  the  beer  remaining  in  the  retort,  sufficient  distilled  water  is  then  to  be  added,  that 
the  entire  bulk  of  fluid  may  once  more  be  equal  to  3600  grain  measures ;  and  the  tem- 
perature of  the  mixture  having  fallen  to  60®  Fahr.,  its  specific  gravity  must  be  deter- 
mined in  the  usual  way,  and  this  reduced  to  pounds  per  barrel,  by  multiplying  the  ex- 
cess above  1000  by  360,  and  dividing  the  product  by  1000.  The  whole  of  tliese  weights, 
added  together,  gives  the  original  weight  of  the  wort  Thus,  for  example,  we  will  sup- 
pose that  3600  grs.  of  a  particular  beer  have  given  1300  gr.  of  a  dilute  alcohol,  of 
specific  gravity  '9731,  and  consequently  containing  about  17^  per  cent.,  by  weight,  of 
alcohol ;  again,  that  the  same  quantity  of  beer,  when  tested  by  ammonia,  has  indi- 
cated 30  grs.  of  acetic  acid ;  and,  lastly,  that  the  spent  wash,  when  filled  up  with 
distilled  water  to  its  primary  bulk,  has,  at  60",  a  specific  gravity  of  1*016 ; — then  the 
total  alcohol  would  be  in  360  grs.,  or  the  representative  of  a  barrel,  22^  grs.,  and  the 
acetic  acid  in  the  same  quantity,  3  grs. :  hence  we  have  the  following  results :  — 


Alcohol,  22J  grs.,  equal  to 

Acetic  acid,  3  grs. 

Spent  wash,  of  sp.  grav.  1*016 


Grs.  of  sogar.     Brewer's  libs. 
-      42*2     or     16* 
6-  1-9 

6-76 


Total  weight 


23*66 


It  might  be  thought  that  the  proper  kind  of  sugar  to  select  in  this  instance,  as  the 
representative  of  alcohol  and  acetic  acid,  should  be  grape  sugar,  whose  atomic  weight 
is  180 ;  but  it  has  long  ago  been  shown  by  Dr.  Ure,  that  the  kind  of  sugar  actually 
employed  in  the  construction  of  our  saccharometer  tables  must  have  been  cane  sugar, 
the  atom  of  which  is  171 ;  and  hence  the  reason  why  it  must  be  employed  in  this 
calculation. 

We  may  now  turn  our  attention  to  the  business  of  the  distiller,  which  is  a  kind  of 


BREWING. 


269 


supplementary  operation  to  that  of  the  brewer.    There  are,  however,  some  important 
differences,  both  in  mashing  and  fermenting,  between  these  two  methods  of  producing 
alcohol ;  for  the  principal  object  of  the  brewer  is  to  secure  flavour  and  transparency 
to  the  fermented  product^  whilst  the  sole  care  of  the  distiller  is  to  ensure  the  complete 
alcoholisation  of  all  the  saccharine  and  gummy  constituents  of  this  wort     We  have 
seen  that  to  the  brewer  the  presence  of  dextrine  was  essential ;  whereas,  in  distillation, 
the  more  purely  saccharine  the  wort  the  better.     On  this  account,  although  malt  is 
much  dearer  than  raw  grain,  many  eminent  distillers  continue  to  employ  it  alone,  from 
the  simple  circumstance  that  its  relatively  large  contents  of  diastase  furnishes,  in  the 
limited  period  assigned  for  mashing,  an  infinitely  more  saccharine  wort  than  can  be 
produced  in  the  same  space  of  time  from  a  mixture  of  one  part  of  malt  and  seven  or 
eight  of  barley  meal.     Nevertheless  by  maintaining  the  wort  from  the  latter  at  a 
sufficient  temperature  for  a  few  hours,  as  indicated  with  respect  to  beer-wort,  the 
diastase  in  it  would  exert  its  specific  action  upon  the  dextrine,  and,  in  the  end,  give  as 
saccharine  a  wort  from  mixed  grain  as  from  pure  malt.    This  subject  is  peculiarly 
worthy  of  the  attention  of  distillers ;  for  the  sluggish  fermentative  qualities  of  dextrine 
are  such,  that  very  frequently  a  considerable  quantity  of  this  substance  remains  in  the 
wash  unacted  on,  and  passes  away  with  the  residue  as  a  waste  product.     It  is,  indeed, 
customary  for  the  distiller  to  seek  a  remedy  for  this,  in  the  employment  of  large  and 
frequently  repeated  additions  of  yeast ;  and  there  can  be  no  doubt  as  to  the  propriety 
of  this  measure.     Still,  however,  the  true  solution  of  this  difficulty  must  be  referred 
to  a  period  anterior  to  fermentation,  and  it  is  in  the  under-back  where  it  should  be 
grappled  with  and  vanquished. 

If  we  examine  with  care  the  catalytic  effect  of  diastase  upon  starch,  we  shall  find 
that  the  time  employed  by  the  distiller  is  far  too  short  to  achieve  the  object  which 
it  is  his  interest  to  bring  about.  In  the  case  of  the  brewer,  many  conditions,  as 
we  have  pointed  out,  require  to  be  foreseen  and  provided  for;  and  hence  a  uniform 
system  of  mashing  is  to  be  condemned  in  brewing ;  but  the  distiller  has  only  one  single 
circunastance  to  bear  in  mind,  and  that  is,  if  possible,  the  total  conversion  of  all  the 
hordeine,  starch,  dextrine,  and  other  constituents  of  his  grain  and  wort  into  sugar. 
In  fact,  he  can  scarcely  by  any  chance  mash  too  long  or  keep  his  wort  at  170°  for 
too  many  hours ; — at  all  events,  the  following  observations  demonstrate  that  the  time 
now  employed  is  barely  one-fourth  of  that  necessary  for  success,  under  the  most 
Cavourable  circumstances :— A  mixture,  composed  of  1  part  of  very  fine  malt  and 
7  parts  of  barley-meal,  was  mashed  with  great  care  in  a  vessel  capable  of  having  its 
temperature  kept  at  any  required  degree  for  many  consecutive  hours.  The  heat  of  the 
water  was  180°;  and  it  was  found,  after  thorough  mixing,  that  this  had  fallen  to  168°,  at 
which  point  it  was  accordingly  decided  to  maintain  it,  and  a  series  of  experimental 
essays  were  made  upon  each  sample  of  the  wort,  with  the  view  of  illustrating  the  pr<>- 
gressive  formation  of  sugar.    The  results  were  as  follows : — 


2  hours  after 

mashing 

3     ditto 

ditto 

4    ditto 

ditto 

6    ditto 

ditto 

6    ditto 

ditto 

7     ditto 

ditto 

8     ditto 

ditto 

9     ditto 

ditto 

10    ditto 

ditto 

11     ditto 

ditto 

12    ditto 

ditto 

Sugar. 

Dextrine 

1*3 

18-7 

41 

15*9 

6*3 

13*7 

8-     V 

12- 

9*2 

10*8 

10*7 

9-3 

12* 

8- 

13*3 

6-7 

14*5 

5*5 

15-7 

4^3 

16-9 

31 

^  Hence,  instead  of  three  hours,  which  is  the  period  commonly  used  for  mashing,  the 
distiller  would  be  warranted  in  continuing  this  operation  for  twelve  hours.  In  reality 
however,  it  is  only  the  wort  which  requires  this  treatment ;  for,  after  the  third  hour  all 
the  starch  and  nearly  the  whole  of  the  hordeine  have  become  soluble,  and  nothing  but 
continued  heat  is  required  to  complete  the  saccharification  of  the  wort.  The  working 
of  the  mash-tun  need  not  therefore  be  varied,  as  it  will  suffice  to  maintain  the  under- 
back  for  6  or  8  hours  at  a  temperature  of  170°.  The  advantage  of  converting  all  the 
dextrine  into  sugar  is  not  limited  to  the  mere  saving  of  material,  or  the  production  of 
more  alcohol,  for  there  is  another  and  most  important  object  gained.  Sugar 
ferments  more  freely  and  at  a  lower  temperature  than  dextrine,  consequently  the  heat 
of  the  fermenting  vat  need  never  rise  so  high,  nor  require  the  large  quantity  of  yeast 
now  employed  for  the  purpose  of  forcing  a  rapid  and  hot  fermentation.  Thus  the 
tendency  to  generate  fusel  oil  would  be  destroyed,  as  there  is  not  the  slightest  doubt 
that  the  formation  of  this  oil  is  due  to  an  excess  of  temperature  in  the  fermenting-vat^ 


P 


270 


BRICK. 


BRICK. 


271 


li 


and  constantly  bears  a  relation  to  the  amount  of  dextrine  in  the  wort ;  for  this,  as  mre 
have  before  stated,  necessitates  the  employment  of  a  higher  fermenting  heat  than  sugar, 
by  which  the  elements  of  the  decomposing  materials  take  on  new  and  unusual  arrange- 
ments. The  presence  of  fusel  oil  in  spirit  is  a  serious  impediment  to  the  distiller,  and 
either  retards  the  sale  of  his  produce,  or  diminishes  its  value  in  the  market. 

As  usual,  the  Excise  regulations  interfere  much  with  the  progress  of  this,  as  of  every 
other  manufacture  under  fiscal  superintendence.  Careful  to  prevent  fraud,  they  cripple 
industry,  and  seek,  as  it  were,  to  secure  the  honesty  of  the  labourer  by  cutting  off  his 
hand  : — ignorant  or  careless,  meanwhile,  of  the  permanent  mischief  which  they  inflicts 
Yet,  we  know  of  no  more  fitting  subject  for  fiscal  burdens,  than  the  manufacture  of 
ardent  spirits ;  and  had  Excise  interference  been  limited  to  this  branch  of  industry,  we 
should  have  deemed  it  a  matter  for  congratulation,  rather  than  otherwise.  Neverthe- 
less, consistency  is  a  kind  of  virtue  in  politics ;  and  we  cannot  imagine  why  the  quasi 
superior,  moral,  and  intellectual  status  of  Ireland  is  continually  tempted\o  err,  by  a  low 
duty  of  but  2«,  Sd.  per  gallon,  whilst  nearly  three  times  this  amount  is  needed  to  repress 
the  Dad  habits  of  the  people  of  England.  The  duty  now  charged  is,  for  England  7«.  lOdl, 
for  Scotland  3«.  Sd.,  and  for  Ireland  2«.  8ct  per  gallon  of  proof  spirits :  but  on  what 
principle  this  graduated  scale  of  temptation  to  drunkenness  has  been  eo  fixed,  we  are 
qnite  unable  to  conceive.  To  return,  however,  to  the  question  of  distillation,  the  duty 
«an  be  charged  the  distiller  in  any  one  of  three  ways, viz.  according  to  the  gravity  of  the 
wort  he  uses :  the  attenuation  of  that  wort  by  fermentation  ;  or  lastly,  the  actual  quan- 
tity of  spirit  which  he  produces ;  the  latter  being,  of  course,  the  only  just  mode  of  charge. 
The  restrictions  and  penalties  are  excessive,  as  our  courts  of  law  too  frequently  testify ; 
*nd  the  notorious  prevalence  of  smuggling  seems  to  prove  that  the  present  rates  of  duty 
are  too  high,  and  offer  a  premium  for  fraud  greater  than  the  terror  of  a  temporary  im- 
prisonment The  greatest  improvement  in  modern  times,  as  regards  distillation,  is  that 
Drought  about  by  the  invention  of  the  apparatus,  now  well  known  under  the  name  of 
"  Coffey's  stilL"  It  would  be  foreign  to  our  task  to  give  a  minute  description  of  this 
contrivance  here  (see  Still);  its  principle  is  similar  to  that  of  the  "cascade  chi- 
mique"  of  Clement  Desormes.  The  wort,  or  other  fluid  to  be  distilled,  is  made  to  flow 
over  a  very  extensive  surface  in  contact  with  a  current  of  steam  passing  in  an  opposite 
direction ;  by  which  means  the  steam  is  condensed,  and  giving  up  its  latent  heat  to  the 
more  volatile  spirit,  this  latter  is  driven  on  into  the  condenser  in  a  state  of  great 
purity ;  whilst  the  residuary  wort  and  the  condensed  steam  flow  out  of  the  vessel  from 
beneath  in  a  continual  stream,  Mr.  Coffey  had  many  impediments  to  contend  with, 
from  the  opposition  of  the  Excise  authorities,  in  his  first  attempt  to  introduce  this  in- 
genious invention  into  public  use ;  but  prejudice  and  ignorance  have  at  length  given 
way,  and  the  Coffey's  still  may  be  now  seen  in  operation  at  almost  every  large  distillery 
in  the  kingdom.  After  the  distiller  has  paid  duty  on  the  spirit  which  he  has  manufac- 
tured, it  is  transmitted  to  the  rectifier,  whose  premises  must  be  at  a  considerable  distance 
from  the  distillery,  according  to  act  of  parliament.  The  business  of  the  rectifier  is  to 
purify  the  spirit  by  separating  its  fusel  oil ;  and  this  he  commonly  effects  through  the 
agency  of  caustic  potash.  The  impure  spirit  being  mixed  with  a  portion  of  potash, 
and  carbonate  of  potash,  is  carefully  distilled  or  rectified,  until  it  ceases  to  possess  any 
disagreeable  odour,  when  it  is  again  distilled  in  contact  with  certain  aromatic  substances, 
to  give  it  the  requisite  qualities  of  the  particular  spirit  or  liquor  desired.  There  is,  how- 
ever, too  much  reason  to  fear  that  the  necessary  measures  of  purification  are  neglected 
in  the  case  of  common  gin, — the  defect  being  merely  covered  or  concealed  beneath 
more  powerful  odours.  This  practice  cannot  be  too  strongly  reprobated;  for  experi- 
ments made  purposely  on  dogs  have  convinced  us  that  fusel  oil  is  a  highly  poisonous 
Bubstance,  and  possesses  acro-narcotic  powere  of  no  ordinary  energy.  Its  removal  from 
an  article  of  universal  consumption,  like  spirits,  ought  therefore  to  be  deemed  an  im- 
portant subject  for  sanitary  legislation,  and  not  left  to  the  casual  skill  or  dubious 
honesty  of  any  class  of  manufacturers  whatever.  There  is  more  or  less  fusel  oil  in  all 
the  gin  we  have  examined. 

BRICK.  {Brique,  Fr. ;  Backsteine,  ziegelsteine,  Germ.)  A  solid,  commonly  rectan- 
gular, composed  of  clay  hardened  by  heat,  and  intended  for  building  purposes.  The 
natural  mixture  of  clay  and  sand,  called  loatn,  as  well  as  marl,  which  consists  of  lime 
and  clay,  with  little  or  no  sand,  constitutes  also  a  good  material  for  making  bricks. 
The  poorer  the  marl  is  in  lime,  the  worse  adapted  it  is  for  agricultural  purposes,  and 
the  better  for  the  brick  manufacturer,  being  less  liable  to  fuse  in  his  kiln.  When  a 
natural  compound  of  silica  and  clay  can  be  got  nearly  free  from  lime  and  magnesia,  it 
forms  a  kind  of  bricks  very  refractory  in  the  furnace,  hence  termed  ^re-bricks.  Such  a 
material  is  the  slate-clay,  ichieferthon,  of  our  coal  measures,  found  abundantly,  and  of 
excellent  quality,  at  Stourbridge,  and  in  the  neighbourhood  of  Newcastle  and  Glasgow. 
The  Loudon  brick-makers  add  to  the  clay  about  one-third  of  coal  ashes  obtained  from 
the  kitchen  dust-holes ;  so  that  when  the  bricks  are  put  into  the  kiln,  the  quantity  of 


coaly  matter  attached  to  their  surface  serves  to  economise  fuel,  and  makes  them  less 
apt  to  shrink  in  the  fire ;  though  they  are  less  compact,  and  probably  less  durable  than 
the  bricks  made  in  the  coal  districts  of  England. 

The  general  process  of  brick-making  consists  in  digging  up  the  clay  in  autumn ; 
exposing  it,  during  the  whole  winter,  to  the  frost,  and  the  action  of  the  air,  turning  it 
repeatedly,  and  working  it  with  the  spade ;  breaking  down  the  clay  lumps  in  spring, 
throwing  them  into  shallow  pits,  to  be  watered  and  soaked  for  several  days.  The  next 
step  is  to  temper  the  clay,  which  is  generally  done  by  the  treading  of  men  or  oxen^ 
In  the  neighbourhood  of  London,  however,  this  process  is  performed  in  a  horse-milL 
The  kneading  of  the  clay  is,  in  fact,  the  most  laborious  but  indispensable  part  of  the 
whole  business ;  and  that  on  which,  in  a  great  measure,  the  quality  of  the  bricks 
depends.  All  the  stones,  particularly  the  ferruginous,  calcareous,  and  pyritous  kinds, 
should  be  removed,  and  the  clay  worked  into  a  homogeneous  paste  with  as  little  water 
as  possible. 

The  earth,  being  sufficiently  kneaded,  is  brought  to  the  bench  of  the  moulder,  who 
works  the  clay  into  a  mould  made  of  wood  or  iron,  and  strikes  off  the  superfluous 
matter.  The  bricks  are  next  delivered  from  the  mould,  and  ranged  on  the  ground ; 
and  when  they  have  acquired  sufficient  firmness  to  bear  handling,  they  are  dressed  with 
a  knife,  and  staked  or  built  up  in  long  dwarf  walls,  thatched  over,  and  left  to  dry.  An 
able  workman  will  make,  by  hand,  5000  bricks  in  a  day. 

The  different  kinds  of  bricks  made  in  England  are  principally  place  bricks,  gray  and 
red  stocks,  marl  facing  bricks,  and  cutting  bricks.  The  place  bricks  and  stocks  are  used 
in  common  walling.  The  marls  are  made  in  the  neighbourhood  of  London,  and  used 
in  the  outside  of  buildings ;  they  are  very  beautiful  bricks,  of  a  fine  j'ellow  colour, 
hard,  and  well  burnt,  and,  in  every  respect,  superior  to  the  stocks.  The  finest  kind  of 
marl  and  red  bricks,  called  cutting  bricks,  are  used  in  the  arches  over  windows  and 
doors,  being  rubbed  to  a  centre,  and  gauged  to  a  height 

In  France  attempts  were  long  ago  made  to  substitute  animals  and  machines  for  the 
treading  of  men's  feet  in  the  clay  kneading  pit ;  but  it  was  found  that  their  schemes 
could  not  replace,  with  advantage,  human  labour  where  it  is  so  cheap,  particularly  for 
separating  the  stones  and  heterogeneous  matter  from  the  loam.  The  more  it  is  worked, 
the  denser,  more  uniform,  and  more  durable,  the  bricks  which  are  made  of  it  A  good 
French  workman,  in  a  day's  labour  of  12  or  13  hours,  it  has  been  said,  is  able  to  mould 
from  9000  to  10,000  bricks,  9  inches  long,  4^  inches  broad,  and  2^  thick ;  but  he  must 
nave  good  assistants  under  him.  In  many  brickworks  near  Paris,  screw-presies  are 
aow  used  for  consolidating  the  bricks  and  paving  tiles  in  their  moulds.  M.  Mollerat 
employed  the  hydraulic  press  for  the  purpose  of  condensing  pulverized  clay,  which, 
after  baking,  formed  beautiful  bricks ;  but  the  process  was  too  tedious  and  costly.  An 
ingenious  contrivance  for  moulding  bricks  mechanically,  is  said  to  be  employed  near 
Washington,  in  America.  This  machine  moulds  30,000  in  a  day's  work  of  J2  hours, 
with  the  help  of  one  horse,  yoked  to  a  gin  wheel,  and  the  bricks  are  so  dry  when 
discharged  from  their  moulds,  as  to  be  ready  for  immediate  burning.  The  machine  is 
described,  with  figures,  in  the  Bulletin  de  la  Societe  d^EncouragemeTtt  for  1819,  p.  361. 
See  further  on^  an  account  of  our  recent  patents. 

Bricks,  in  this  country,  are  generally  baked  either  in  a  clamp  or  in  a  kiln.  The 
latter  is  the  preferable  method,  as  less  waste  arises,  less  fuel  is  consumed,  and  the  bricks 
are  sooner  burnt.  The  kiln  is  usually  13  feet  long,  by  10^  feet  wide,  and  about  12  feet 
in  height.  The  walls  are  one  foot  two  inches  thick,  carried  up  a  little  out  of  the 
perpendicular,  inclining  towards  each  other  at  the  top.  The  bricks  are  placed  on  flat 
arches,  having  holes  left  in  them  resembling  lattice-work;  the  kiln  is  then  covered 
with  pieces  of  tiles  and  bricks,  and  some  wood  put  in,  to  dry  them  with  a  gentle  fire. 
This  continues  two  or  three  days  before  they  are  ready  for  burning,  which  is  known  by 
the  smoke  turning  from  a  darkish  color  to  transparent.  The  mouth  or  mouths  of  the 
kiln  are  now  dammed  up  with  a  shinlog,  which  consists  of  pieces  of  bricks  piled  one 
upon  another,  and  closed  with  wet  brick  earth,  leaving  above  it  just  room  sufficient  to 
receive  a  fagot.  The  fagots  are  made  of  furze,  heath,  brake,  fern,  &c.,  and  the  kiln 
is  supplied  with  these  until  its  arches  look  white,  and  the  fire  appears  at  the  top ;  upon 
which  the  fire  is  slackened  for  an  hour,  and  the  kiln  allowed  graduedly  to  cool.  This 
heating  and  cooling  is  repeated  until  the  bricks  be  thoroughly  burnt,  which  is  generally 
done  in  48  hours.     One  of  these  kilns  will  hold  about  20,000  bricks. 

Clamps  are  also  in  common  use.  They  are  made  of  the  bricks  themselves,  and 
generally  of  an  oblong  form.  The  foundation  is  laid  with  place  brick,  or  the  driest  of 
those  just  made,  and  then  the  bricks  to  be  burnt  are  built  up,  tier  upon  tier,  as  high  as 
the  clamp  is  meant  to  be,  with  two  or  three  inches  of  breeze  or  cinders  strewed  between 
each  layer  of  bricks,  and  the  whole  covered  with  a  thick  stratum  of  breeze.  The  fire- 
place is  perpendicular,  about  three  feet  high,  and  generally  placed  at  the  west  end ;  and 
the  flues  are  formed  by  gathering  or  arching  the  bricks  over,  so  as  to  leave  a  sp0ce 


272 


BRICK. 


BRICK. 


273 


I 


I 


between  each  of  nearly  a  brick  wide.  The  flues  run  straight  through  the  clamp,  and 
are  filled  with  wood,  coals,  and  breeze,  pressed  closely  together.  If  the  bricks  are  to 
be  burnt  off  quickly,  which  may  be  done  in  20  or  30  days,  according  as  the  weather 
may  suit,  the  flues  should  be  only  at  about  six  feet  distance;  but  if  there  be  no 
immediate  hurry,  they  may  be  placed  nine  feet  asunder,  and  the  clamp  left  to  bum 
off  slowly. 

Floating  bricks  are  a  very  ancient  invention  :  they  are  so  lisht  as  to  swim  in  water; 
and  Pliny  tells  us,  that  they  were  made  at  Marseilles ;  at  Colento,  in  Spain ;  and  at 
Pittane,  in  Asia.  This  invention,  however,  was  completely  lost,  until  M.  Fabbroni 
published  a  discovery  of  a  method  to  imitate  the  floating  bricks  of  the  ancients. 
According  to  Posidonius,  these  bricks  are  made  of  a  kind  of  argillaceous  earth,  which 
was  empioyed  to  clean  silver  plate.  But  as  it  could  not  be  our  tripoli,  which  is  too 
heavy  to  float  in  water,  M.  Fabbroni  tried  several  experiments  with  mineral  argaric, 
guhr,  lac-lunae,  and  fossil  meal,  which  last  was  found  to  be  the  very  substance  of  which 
he  was  in  search.  This  earth  is  abundant  in  Tuscany,  and  is  found  near  Casteldelpiano, 
in  the  territories  of  Sienna.  According  to  the  analysis  of  M.  Fabbroni,  it  consists  of 
65  parts  of  silicious  earth,  15  of  magnesia,  14  of  water,  12  of  alumina,  3  of  lime,  and  I  oi 
iron.  It  exhales  an  argillaceous  odor,  and,  when  sprinkled  with  water,  throws  out  m 
light  whitish  smoke.  It  is  infusible  in  the  fire;  and.  though  it  loses  about  an  eighth 
part  of  its  weight,  its  bulk  is  scarcely  diminished.  Bricks  composed  of  this  substance, 
either  baked  or  unbaked,  float  in  water ;  and  a  twentieth  part  of  clay  may  be  added  to 
their  composition  without  taking  away  their  property  of  swimming.  These  bricks 
resist  water,  unite  perfectly  with  lime,  are  subject  to  no  alteration  from  heat  or  cold, 
and  the  baked  differ  from  the  unbaked  only  in  the  sonorous  quality  which  they  have 
acquired  from  the  fire.  Their  strength  is  little  inferior  to  that  of  common  bricks,  but 
much  greater  in  proportion  to  their  weight ;  for  M.  Fabbroni  found,  that  a  floating 
brick,  measuring  7  inches  in  length,  4^  in  breadth,  and  one  inch  eight  lines  in  thick* 
ness,  weighed  only  14^  ounces ;  whereas  a  common  brick  weighed  5  pounds  6|  ounces. 
The  use  of  these  bricks  may  be  very  important  in  the  construction  of  powder  magazines 
and  reverberatory  furnaces,  as  they  are  such  bad  conductors  of  heat,  that  one  end  may 
be  made  red  hot  while  the  other  is  held  in  the  hand.  They  may  also  be  employed  for 
buildings  that  require  to  be  light;  such  as  cookinsr-places  in  ships,  and  floating  batteries, 
the  parapets  of  which  would  be  proof  against  red-hot  bullets. 

The  following  plan  of  a  furnace  or  kiln  for  burning  tiles  has  been  found  very  con- 
venient : — 

J*\g.  198.,  front  view,  a  a,  B  b,  the  solid  walls  ot  the  tumace  ;  a  a  a,  openings  to  the 
ash-pit,  and  the  draught  hole;  b  b  b,  openings  for  the  supply  of  fuel,  furnished  with  a 
sheet-iron  door.     Fif/^  190.  PJai!  of  tlu-  :»sli-))ifs  and  uir  channels  c  c  c.     Tlie  principal 


B 


D   D 

D 

B 

a      a 

A 

n 


198 

branch  of  the  ash-pit  n  r>  i>,  i?  also  the  oporiinir  for  taking  out  the  tiles,  after  removing 
the  grate;  e,  the  smoke  flue.     lu/.   2o0.  Plan  of  the  kiln  seen  from  above.     Tlie 

grater*  h  ii  it.     The  tiles  to  be  fired  are  arranged  upon  the 
spaces  f  f  ff. 

7^%.  201.  is  the  plan  and  section  of  one  of  the  grates  upon 
a  much  larger  scale  than  in  the  preceding  figures. 

Mechanical  brick  moulding. — Messre.  Lyne  and  Stainford  ob- 
tained in  August,  1825,  a  patent  for  a  machine  for  making  a 
considerable  number  of  bricks  at  one  operation.  It  consists,  in 
the  first  place,  of  a  cylindrical  pug-mill  of  the  kind  usually  em- 
ployed for  comminuting  clay  for  bricks  and  tiles,  furnishca  with 
rotatory  knives,  or  cutters,  for  breaking  the  lumps  and  mixing 
the  clay  with  the  other  materials  of  which  bricks  are  commonly 
made.  Secondly,  of  two  movable  moulds,  in  each  of  which 
fifteen  bricks  are  made  at  once ;  these  moulds  being  made  to 
travel  to  and  fro  in  the  machine  for  the  purpose  of  being  alter- 
nately brought  under  the  pug-mill  to  be  fitted  with  the  clay, 


and  then  removed  to  situations  where  plungers  are  enabled  to  act  upon  them.  Thirdly, 
m  a  contrivance  by  which  the  plungers  are  made  to  descend,  for  the  purpose  of  com- 
pressing the  material  and  discharging  it  from  the  mould  in  the  form  of  bricks. 
Fourthly,  in  the  method  of  constructing  and  working  trucks  which  carry  the  receiving 
boards,  and  conduct  the  bricks  away  as  they  are  formed. 

Fig.  202.  exhibits  the  general  construction  of  the  apparatus ;  both  ends  of  which 
being  exactly  similar,  little  more  than  half  of  the  machine  is  represented,  a  is  the 
cylindrical  pug-mill,  shown  partly  in  section,  which  is  supplied  with  the  clay  and  other 


202 


i'l:i  Ii  Hi  M  I  |i  I'rTnmrprrrTrraw  i!lil!ll'll!!l!l  |i||i|ni|inlljiiHlli 


y 


\ 


— ■tt"A'l-'}l.l*!!iil'ii'ir-l! 


7 


materials  from  a  hopper  above ;  b  b,  are  the  rotatory  knives  or  cutters,  which  are  at 
tached  to  the  vertical  shaft,  and,  being  placed  obliquely,  press  the  clay  down  towards  the 
bottom  of  the  cylinder,  in  the  act  of  breaking  and  mixing  it  as  the  shaft  revolves.  The 
lower  part  of  the  cylinder  is  open  ;  and  immediately  under  it  the  mould  is  placed  in 
which  the  bricks  are  to  be  formed.  These  moulds  run  to  and  fro  upon  ledges  in  the 
side  frames  of  the  machine  ;  one  of  the  moulds  only  can  be  shown  by  dots  in  the  figure, 
the  side  rail  intervening ;  they  are  situated  at  c  c,  and  are  formed  of  bars  of  iron 
crossing  each  other,  and  encompassed  with  a  frame.  The  mould  resembles  an  ordinary 
sash  window  in  its  form,  being  divided  into  rectangular  compartments  (fifteen  are  pro- 
posed in  each)  of  the  dimensions  of  the  intended  bricks,  but  suflSciently  deep  to  allow 
the  material,  after  being  considerably  pressed  in  the  mould,  to  leave  it,  when  dis- 
charged, of  the  usual  thickness  of  a  common  brick. 

The  mould  being  open  at  top  and  bottom,  the  material  is  allowed  to  pass  into  it, 
when  situated  exactly  under  the  cylinder ;  and  the  lower  side  of  the  mould,  when  sc 
placed,  18  to  be  closed  by  a  flat  board  d^  supported  by  the  trunk  e,  which  is  raised  by  a 
lever  and  roller  beneath,  running  upon  a  plane  rail  with  inclined  ends. 

Tlie  central  shaft,  /,  is  kept  in  continual  rotatory  motion,  by  the  revolution  of  tht 
upper  horizontal  wheel  g,  of  which  it  is  the  axis ;  and  this  whe'el  may  be  turned  by  a 
hot-se  yoked  to  a  radiating  arm,  or  by  any  other  means.  A  part  of  the  circumference 
of  the  wheel  g,  has  teeth  which  are  intended  at  certain  periods  of  its  revolution  to  take 
into  a  toothed  pinion,  fixed  upon  the  top  of  a  vertical  shaft  h  h.  At  the  lower  part  of 
this  vertical  shaft,  there  is  a  pulley  i,  over  which  a  chain  is  passed  that  is  connected  to 
the  two  moulds  c,  and  to  the  frame  in  which  the  trucks  are  supported ;  by  the  rotation 
of  the  vertical  shaft,  the  pulley  winds  a  chain,  and  draws  the  moulds  andf  truck  framee 
along. 

The  clay  and  other  material  having  been  forced  down  from  the  cylinder  into  the 
mould,  the  teeth  of  the  horizontal  wheel  g  now  come  into  geer  with  the  pinion  upon 
You  L  2  N 


274 


BRICK. 


fi,  and  turn  it  and  the  shaft  and  pulley  i,  by  which  the  chain  is  wound,  and  the  mould 
at  the  right  hand  of  the  machine  brought  into  the  situation  shown  in  the  figure ;  a 
scraper  or  edge-bar  under  the  pug-mill  having  levelled  the  upper  face  of  the  clay  in  the 
mould,  and  the  board  d,  supported  by  the  truck  e,  formed  the  flat  under  side. 

The  mould  being  brought  into  this  position,  it  is  now  necessary  to  compress  the  ma- 
terials, which  is  done  by  the  descent  of  the  plungers  k  k.  A  friction-roller  I,  pendant 
from  the  under  side  of  the  horizontal  wheel,  as  that  wheel  revolves,  comes  in  contact 
with  an  inclined  plane,  at  the  top  of  the  shaft  of  the  plungers;  and,  as  the  friction- 
roller  passes  over  this  inclined  plane,  the  plungers  are  made  to  descend  into  the  mould, 
and  to  compress  the  material ;  the  resistance  of  the  board  beneath  causing  the  clay  to 
be  squeezed  into  a  compact  state.  When  this  has  been  effectually  accomplished,  the 
further  descent  of  the  plungers  brings  a  pin  wi,  against  the  upper  end  of  a  quadrant 
catch-lever  n,  and,  by  depressing  this  quadrant,  causes  the  balance-lever  upon  which  the 
truck  is  now  supported  to  rise  at  that  end,  and  to  allow  the  truck  with  the  board  d  to 
descend,  as  shown  by  dots ;  the  plungers  at  the  same  time  forcing  out  the  bricks  from 
the  moulds,  whereby  they  are  deposited  upon  the  board  d;  when,  by  drawing  the  truck 
forward  out  of  the  machme,  the  board  with  the  bricks  may  be  removed  and  replaced  by 
another  board.  The  truck  may  then  be  again  introduced  into  the  machine,  ready  to 
receive  the  next  parcel  of  bricks. 

By  the  time  that  the  discharge  of  the  bricks  from  this  mould  has  been  effected,  the 
other  mould  under  the  pug  cylinder  has  become  filled  with  the  cla}'^,  when  the  teeth  of 
the  horizontal  wheel  coming  round,  take  into  a  pinion  upon  the  top  of  a  vertical  shaft, 
exactly  similar  to  that  at  A,  but  at  the  reverse  end  of  the  machine,  and  cause  the 
moulds  and  the  frame  supporting  the  trucks  to  be  slidden  to  the  left  end  of  the  machine ; 
the  upper  surface  of  the  mould  being  scraped  level  in  its  progress,  in  the  way  already 
described.  This  movement  brings  the  friction-wheel  o,  up  the  inclined  plane,  and 
thereby  raises  the  truck,  with  the  board  to  the  under  side  of  the  mould,  ready  to  receive 
another  supply  of  clay  ;  and  the  mould  at  the  left  hand  side  of  the  machine  being  now 
in  its  proper  situation  under  the  plungers,  the  clay  becomes  compressed,  and  the  bricks 
discharged  from  the  mould  in  the  way  described  in  the  former  instance ;  when  this  truck, 
being  drawn  out,  the  bricks  are  removed  to  be  dried  and  baked,  and  another  board 
is  placed  in  the  same  situation.  There  are  boxes,  p,  upon  each  side  of  the  pug  cylinder 
containing  sand,  at  the  lower  parts  of  which  small  sliders  are  to  be  opened  (by  con- 
trivances not  shown  in  the  figure)  as  the  mould  passes  under  them,  for  the  purpose  of 
Bcattering  sand  upon  the  clay  in  the  mould  to  prevent  its  adhering  to  the  plungers. 
There  is  also  a  rack  and  toothed  sector,  with  a  balance-weight  connected  to  the  inclined 
plane  at  the  top  of  the  plunger-rods,  for  the  purpose  of  raising  the  plunger  after  the 
friction-roller  has  passed  over  it.  And  there  is  a  sprin?  acting  against  the  back  of  the 
quadrant-catch  for  the  purpose  of  throwing  it  into  its  former  situation,  after  the  pin  of 
the  plunger  has  risen. 

One  of  the  latest,  and  apparently  most  effective  machines  for  brick-making,  is  that 
patented  by  Mr.  jfcdward  Jones,  of  Birmingham,  in  August,  183o.  His  improvements 
are  described  under  four  heads ;  the  first  applies  to  a  machiHe  for  moulding  the  earth 
into  bricks  in  a  circular  frame-plate  horizontally,  containing  a  series  of  moulds  or  rec- 
tangular boxes,  standing  radially  round  the  circumference  of  the  circular  frame,  into 
which  boxes  successively  the  clay  is  expressed  from  a  stationary  hopper  as  the  frame 
revolves,  and  after  being  so  formed,  the  bricks  are  successively  pushed  out  of  their  boxes, 
each  by  a  piston,  acted  upon  by  an  inclined  plane  below.  The  second  head  of  the  spe- 
cification describes  a  rectangular  horizontal  frame,  having  a  series  of  moulding  boxes 
placed  in  a  straight  range,  which  are  acted  upon  for  pressing  ihe  clay  by  a  corresponding 
range  of  pistons  fixed  in  a  horizontal  frame,  worked  up  and  down  by  rods  extending 
from  a  rotatory  crank  shaf^,  the  moulding  boxes  being  allowed  to  rise  for  the  purpose  ot 
enabling  the  pistons  to  force  out  the  bricks  when  moulded,  and  leave  them  upon  the  bed 
or  board  below.  The  third  head  applies  particularly  to  the  making  of  tiles,  for  the 
flooring  of  kilns  in  which  mall  or  grain  is  to  be  dried.  There  is  in  this  contrivance  a 
rectangular  mould,  with  pointed  pieces  standing  up  for  the  purpose  of  producing  ai»- 
holes  through  the  tiles  as  they  are  moulded,  which  is  done  by  pressing  the  clay  into  the 
moulds  upon  the  points,  and  scraping  off  the  superfluous  matter  at  top  by  hand.  The 
fourth  or  last  head  applies  to  moulding  chimney  pots  in  double  moulds,  which  lake 
to  pieces  for  the  purpose  of  withdrawing  the  pot  when  the  edges  of  the  slabs  or  sides  are 
sufficiently  brought  into  contact. 

"  The  drawing  which  accompanies  the  specification  very  imperfectly  represents  some 
parts  of  the  apparatus,  and  the  description  is  still  more  defective ;  but  as  we  are  ac- 
quainted ^th  ihe  machinery,  we  will  endeavor  to  give  it  an  intelligible  form,  and  quote 
those  parts  of  the  specification  which  point  the  particular  features  of  novelty  proposed  to 
be  claimed  by  the  patentee  as  his  invention,  under  the  several  heads."  * 

*  Mr  NflwtMi,  in  hit  London  Journal,  February,  18J7. 


BRICK.  275 

Fig.   203   represents,   in    ele- 
vation,  the   first-mentioned  ma- 
chine for  moulding  bricks.     The 
moulds  are  formed  in   the   face 
of   a    circular   plate    or  wheel, 
a  a,  a  portion  of  the  upper  sur- 
face of  which  is  represented  in 
the    horizontal   view,    fig.   204. 
Any  convenient  number  of  these 
moulds   are   set  radially  in    the 
wheel,  which   is   mounted  upon 
a    central    pivot,    supported    by 
the  masonry   b  b.     There   is   a 
rim  of   teeth  round    the    outer 
edge  of   the  wheel   a  a,  which 
lake  into  a  pinion  c,  on  a  shaft 
connected  to    the    first  mover; 
and  by  these  means   the  wheel 
a,  with   the   moulding  boxes,  is 
made    to    revolve    horizontally, 
guided  by  arms  with  an ti- friction 
rollers,  which  run  round  a  hori- 
zontal plate  a  a,  fixed  upon  the 
masonry. 

A  hopper,  e,  filled  with  the 
brick  earth  shown  with  one  of  the 
•iw,»o  *u^  r—    <•  41.      1.    1  •         ,  moulding  boxes  in  section,  is  fixed 

r^  th.  Jv.  I  i/^^'L'"  '"'^  X"^^^  ^^^^  ^^^  ^^"^^  may  descend  from  the  hopper 
into  the  several  moulding  boxes  as  the  wheel  passes  round  under  it ;  the  earth  bein- 

Km  of  the  hoppe"  ''  "^  ^'^  '"'^'^'^  ''"^^^^  °^  ^°^^°^^  ^^  ^  ''^^^  '°"«^/>  "^  ^hS 
rJil'^hf ,/^^  bottom  of  each  moulding  box  there  is  a  hole  for  the  passage  of  a  piston 
^ht^K  "PPer  end  of  which  rod  carries  a  piston  with  a  wooden  pallet  upon  it,  icting 

Ihlii?  i  .I."""  K  ?  ^'''  f"^  '^^  ^°^^'  ^"^  «^  ^^'^  ^«^  ^"^^  a  s^all  anli-friction  roller, 
r«v  A  r  i  J"^^  a  revolves,  runs  round  upon  the  face  of  an  oblique  ring  or  incUned 
way,  h  A,  fixed  upon  the  masonry.  ^  v*»ucu 

p«t  of  he  inclined  way  /i,  and  it  will  be  perceived  that  as  the  wheel  revolves  the  niaton 

shown  a?  in  7.  C  r  ^'.f  "^^«;^hem,  severally  up  the  mould,  into  the  situation 
K»?„     .t    '  ^  -^^j  ^^^'  ^T  '^^^"''^  '^^y  """^  *°  ^e  removed  by  hand.    Fresh  pallets 

moufd.W?  ^h'^K^-  r°\'^'  r'?^  P^^'""^'  '^'y>  ^"h  the  moulds,  will  be  ready  foJ 
moulding  fresh  bricks,  when,  by  the  rotation  of  the  wheel  a,  Ihey  are  severally  brought 
under  the  hopper,  the  pistons  having  sunk  to  the  bottoms  of  their  l^xL  2  iL  Sn 
rods  passed  down  the  other  side  of  the  inclined  way  h  '  ^ 

I,  Ji'-t  ^^T^T  f^l'  ft'  ^^""'"^  described  the  first  head  of  his  invention,  he  would 
have  It  understood  that  the  same  may  be  varied  without  departing  from  the  main  Twect 

TnH  '7r"T  '  T^"  '^'l^^  ^'''^"^^"'  ^  ^^"^«  «f  "^«^i^^  ^»»en  worked  by  means  of  an 

inclined  track,  and  m  such  manner  that  bricks,  tiles,  or  other  articles   made  of  brick 

earth,  may   be   capable  of  being  formed  in  a  mould  with  pallets  or  boards  laid  wHMa 

he  moulds,  and  constituting  the  bottom  thereof,  the  bricks  being  removed  from  Tut^ 

forpTl'"'  '^''^  t'r}]'''  "^  ^'^'^'  ''''^''  ^^^"»'  ^'  ^bove  described.  - 1  do  noT,  ther^ 
fore,  confine  myself  to  the  precise  arrangement  of  the  machine  here  shown,  though  it^ 
the  best  with  which  I  am  acquainted  for  the  purpose  "  inouj,n  u  is 

hiv!  t^X'^^^'f  ""^  ^^^  invention  is  another  construction  of  apparatus  .or  moulding 

S;  :  ^^Zr      ''.'-  '"  *-ff  ^^"^"^^'•/'•ame.     Fig.  205  is  a  front  elevation  of  the  ma^ 

t7VJ^'  ^  ^^''?i'*'V^''*  '^'"^  ^^J'^"  transversely,     a  a  is  the  standard  frame-work 

?,^m.  w    if  7^''^  \^^  ^'-M '  *?  .*°  ^^  mov.\AeA.     Near  the  corners  of  this  standard 

L^^Id'ill^^''""  ''rf '^  ^"^^^7i  ^  ""'^  "'•"^'^^'  "P«"  ^^^^^  P»'-^s  the  frame  of  the 
mould  ng  boxes  c,  slides  up  and  down,  and  also  the  bar  d,  carr  ing  the  rods  of  the  pis- 

Lnv  ^\k  ^f  P''^°"f ''''5'''  '^^  Purpose  of  compressing  the  clay  in  the  moulding 
SilU't;^":aT^^^^^  ''''^'  '^^^^^^  ^^^^  ^^^  *^^^-^P«"^  withthe'respectivemoulcJ 
The  sliding  frame  c,  constituting  the  sides  and  ends  of  the  moulding  boxes,  is  sup. 
iZltf.  7t  ^?  /  «VP"«^'  ^^^'^^  ^  /'  ^hich  rods  pass  through  guides  fixed  to 
^Zlt  f  ^^  '^*"^^^  ^i:*"?.^  ""  ""'  *"^  "'  ^^^  ^^^e'-  end  of  each  there  il  a  roller,  bearing 
upon  the  levers  g,  on  each  side  of  the  machine,  but  seen  only  in  fig.  181,  which  levers 


276 


BRICKS. 


BRICKS. 


when  depressed,  allow  the  moulding  boxes  to  descend,  and  rest  upon  the  bed  or  table  of 
the  machine  h  h. 


206 


'[  ^1    ^'    gc>  o| 


T 


T 


In  this  position  of  the  machine  resting  upon  the  bed  or  table,  the  brick-earth  is  to  be 
placed  upon,  and  spread  over,  the  top  of  the  frame  c,  by  the  hands  of  workmen,  when 
the  descent  of  the  plunger  or  pistons  c  c  c,  will  cause  the  earth  to  be  forced  into  the 
moulds,  and  the  bricks  to  be  formed  therein.  To  effect  this,  rotatory  power  is  to  be 
applied  to  the  toothed  wheel  i,  fixed  on  the  end  of  the  main  driving  crank  shaft  k  k, 
which  on  revolving  will,  by  means  of  the  crank  rods  1 1,  bring  down  the  bar  a,  with  the 
pistons  or  plungers  eee,  and  compress  the  earth  compactly  into  the  moulds,  and  thereby 
form  the  bricks. 

When  this  has  been  done,  the  bricks  are  to  be  released  from  the  moulds  by  the 
moulding  frame  c  rising  up  from  the  bed,  as  shown  in  Jig.  205.,  the  pistons  still  remain- 
ing depressed,  and  bearing  upon  the  upper  surfaces  of  the  bricks.  The  moulding  frame 
is  raised  by  means  of  cams  in,  upon  the  crank  shaft,  which  at  this  part  of  the  operation 
are  brought  under  the  levers^,  for  the  purpose  of  raising  the  cams  and  the  slidmg  rods 
/,  into  the  position  shown  in^^r.  206. 

The  bricks  having  been  thus  formed  and  released  from  their  moulds,  they  are  to  be 
removed  from  the  bed  of  the  machine  by  pushing  forward,  on  the  front  side,  fresh 
boards  or  pallets,  which  of  course  will  drive  the  bricks  out  upon  the  other  side,  whence 
they  are  to  be  removed  by  hand. 

There  is  to  be  a  small  hole  in  the  centre  of  each  pallet,  and  also  in  the  bed,  for  the 
purpose  of  allowing  any  superfluous  earth  to  be  pressed  through  the  moulding  boxes 
when  the  pistons  descend.  And  in  order  to  cut  off  the  projecting  piece  of  clay  which 
would  be  thus  formed  on  the  bottom  of  the  brick,  a  knife-edge  is  in  some  way  connected 
to  the  bed  of  the  machine ;  and  as  the  brick  slides  over  it,  the  knife  separates  the  pro- 
tuberant lump ;  but  the  particular  construction  of  this  part  of  the  apparatus  is  consi- 
dered to  be  of  little  importance ;  and  the  manner  of  effecting  the  object  is  not  clearly 
stated  in  the  specification. 

The  patentee  proposes  a  variation  in  this  construction,  which  he  describes  in  these 
words :  "  It  will  be  evident  that  in  place  of  having  the  moulds  to  rise,  they  may,  by 
suitable  arrangements,  be  made  to  descend  below  the  bricks.  In  this  case,  in  place  ot 
the  boards,  stationary  blocks  to  receive  the  pallets  must  be  fixed  on  the  bed  of  the 
machine,  and  these  blocks  must  be  shaped  in  such  a  manner  as  to  allow  of  the  moul'^«» 
passing  over  them :  and  then  it  will  be  desirable  to  use  the  first  part  of  my  improve- 
ments, that  of  having  the  pallets  within  the  moulds  at  the  time  of  moulding  the  bricks ; 
or  in  case  of  working  with  exceedingly  stiff  brick-earth,  the  pallets  may  be  dispensed 
with."  In  1849,  1,503,961,106  bricks  paid  duty  in  the  United  Kingdom ;  the  revenue 
from  which  was  461,582Z.  68.  Id. 

BRICKS.     Mr.  F.  "W.  Simms,  C.  R,  communicated  to  the  Institution  of  Civil  En- 

g'neers,  in  April  and  May,  1843,  an  account  of  the  process  of  brick-making  for  the 
over  railway.  The  plan  adopted  is  called  slop-moulding,  because  the  mould  is  dipped 
into  water  before  receiving  the  clay,  instead  of  being  sanded  as  in  making  sand-stock 
bricks.  The  workman  throws  the  proper  lump  of  clay  with  some  force  into  the  mould, 
presses  it  down  with  his  hands  to  nil  the  cavities,  and  then  strikes  off  the  surplus  clay 
with  a  stick.  An  attendant  boy,  who  has  previously  placed  another  mould  in  a  water 
trough  by  the  side  of  the  moulding  table,  takes  the  mould  just  filled,  and  carries  it  to 
the  floor,  where  he  carefully  drops  the  brick  from  the  mould  on  its  flat  side,  and  leaves 
it  to  dry ;  by  the  time  he  has  returned  to  the  moulding  table,  and  deposited  the  empty 


277 


mould  m  the  water  trough,  the  brickmaker  will  have  filled  the  other  mould,  for  the 
Doy  to  convey  to  the  floor,  where  they  are  allowed  to  dry,  and  are  then  stacked  in  rea 
dmess  for  being  burned  in  clamps  or  kilns.     The  average  product  is  shown  in  the  fol 
lowing  table: — 


Force  employed. 


1  moulder 
1  temperer 
1  wheeler 
1  carrier  boy 
1  picker  boy 


Area  of  land. 


Roods.      Perches. 


14i 


Duration  of  season    Produce  per  week.  Prodace  per  season. 


Weeks. 


22 


Bricks. 


16,100 


Bricks. 


364,200 


.«ip  w  \n  ♦'^^^  ^i^^  P'"*'**''''^  m  sand-stock  bncks  is  to  that  of  slop-bricks  in  th« 
«nH  tWn  t  f  I  li  '  the  amount  of  labor  is  as  7  to  4;  while  the  quantity  of  land, 
t^?v  nf  .li  .  A  P^' thouf  nd,  IS  nearly  the  same  in  both  processes.     The  qua^ 

ThVLc?  if  t?'""  K^^'"'  ^^^  ^o?  "^^^  ^V**^  ^^^^  «^  10  <=^-  Slhs.  per  thousand  bricks. 
ft,«v  TL1h\'  K^^^^«,7^^2/.  U  ed.  per  thousand.  The  slop-made  bricks  are 
«f h:«  K^lfi  M  ^^''n  ^^?  ^^t  sand-stock.    Mr.  Bennett  stated  to  the  meeting,  that 

?9  rSS  h  ?M  t  r  ^""^^^^  ^^^  ^""^'^^^  ^"°'^^''  «^  sand-stock  bricks  moulded  was 
32,000;  but  that  frequently  so  many  as  37,000,  or  even  50,000,  were  formed.  The 
total  amount  m  the  shrinkage  of  his  bricks  was  i »  of  an  inch  upon  10  inches  in  length ; 
but  this  diflered  with  the  diiferent  clays.  Mr.  Simms  objected  to  the  use  of  machinery 
in  bnck-making,  because  it  caused  economy  only  m  the  moulding,  which  constituted  no 
more  than  about  one  eighth  of  the  total  expense. 

The  principal  varieties  of  bricks  are  called  malm,paviors,  stocks,  grizzles,  places,  nnd 
•huffs.  For  the  first  and  best  kind,  the  clay  was  washed  and  selected  with  care: 
stocks  were  good  enough  for  ordinary  building  purposes ;  the  rest  are  inferior.  The 
diilerence  m  price  between  malms,  paviors,  and  stocks,  was  Ws.  or  20*.  per  1,000:  be- 
tween stocks  and  places,  10*.  The  average  weight  of  a  sand-stock  brick  L  fully  5 
pounds,  that  of  a  slop  is  1  pound  more. 

I  believe  that  the  siliceous  sand  on  the  surface  of  the  sand-stocks  is  useful  in  favoi^ 
mg  adhesion  of  mortar,  by  the  production  of  a  silicate  of  lime.  To  smooth  alnminona 
bricks,  mortar  sometimes  forms  no  stony  adhesion. 

Mr.  Prosj.er,  of  Birmingham,  makes  bricks  by  pressure.  The  clay  is  first  ground 
upon  a  shp  Ailn,  as  if  for  making  pottery,  then  ground  to  a  fine  powder,  and  in  that 
dry  state  it  is  subjected  to  the  heavy  pressure  of  about  250  tons,  in  strong  metal 
moulds,  by  which  means  it  is  reduced  to  about  one  third  of  its  original  thickness. 
J  he  clay  seems  to  have  retained  sufficient  moisture  to  give  it  cohesion,  and  the  tiles 
are  perfectly  sharp  at  the  edges.    They  being  then  baked  within  seggars  by  the  heat  of 

*   •  ?'if  .  ""  ^^**^^  ^"^  ^^^  ^^^^^S'    The  bricks  thus  formed  are  denser  than  usual,  and 
weigh  6|  lbs.,  with  a  specific  gravity  of  2*5. 

Fig,  207.,  represents  Mr.  Hunt's  brick-making  machine.     The  principal  working 


parts  consist  of  2  cyhnders,  each  covered  by  an  endless  web,  and  so  placed  as  to  fonn 
the  front  and  back  of  a  hopper,  the  two  sides  being  iron  plates,  placed  so  that  whea 
the  hopper  is  filled  with  tempered  clay  from  the  pug-mill,  the  lower  part  of  the 
hopper,  and  consequently  the  mass  of  clay  within  it,  has  exactly  the  dimensions  of 
a  brick.  Beneath  the  hopper  an  endless  chain  traverses  simultaneously  with  the 
movement  of  the  cyhnders.  The  pallet-boards  are  laid  at  given  intervals  upon  the 
chain,  and  bemg  thus  placed  under  the  hopper,  while  the  clay  is  brought  down  with 
•  slight  pressure,  a  frame    with  a  wire  stretched  across  it  is  projected  throug  the 


H 


278 


BRICKS. 


i:i 


.;.  t 


PI 


I 


mass  of  clay,  cutting  off  exactly  the  thickness  of  the  brick,  which  is  removed  at  the 
same  moment  by  the  forward  movement  of  the  endless  chain.  This  operation  is 
repeated  each  time  that  a  pallet-board  comes  under  the  hopper. 

The  chief  object  of  this  machine,  which  is  worked  by  hand,  is  to  produce  good 
square  compact  bricks  of  uniform  quality,  using  only  a  slight  pressure.  It  has  been 
found  to  be  very  difficult  to  dry  bricks  made  by  machinery,  where  a  considerable  pres- 
sure has  been  employed,  because,  before  the  evaporation  from  the  centre  of  the  clay  is 
completed,  the  surfaces  have  become  hard  and  peel  off.  The  present  machine  is  in 
operation  in  several  parts  of  England,  producing  usually  about  1200  bricks  per  hour, 
while  each  machine  requires  only  2  men  and  3  boys  to  tend  it,  and  to  take  off  the 
bricks.  The  clot-moulders  are  dispensed  with,  and  the  workmen  are  common 
labourers,  so  that  professed  brick-makers  at  higher  wages  are  not  needed. 

Fig.  208.  shows  Mr.  Hunt's  machine  for  making  tiles,  and  it  is  on  the  same  principle^ 
It  consists  of  two  iron  cylinders,  round  which  webs  or  bands  of  cloth  revolve,  whereby 
the  clay  is  pressed  into  a  slab  of  uniform  thickness,  without  adhering  to  the  cjlinde^Y. 
It  is  then  carried  over  a  covered  wheel,  curved  on  the  rim,  which  gives  the  tile  the 
•emi-cylindrical  or  other  required  form  \  after  which  the  tiles  are  poUshed  and  finished 


by  passing  through  three  iron  moulds  of  a  horse-shoe  fonn,  as  shown  in  the  centre  of 
the  cut,  while  they  are  at  the  same  time  moistened  from  a  water  cylinder  placed  abore 
tbem.  The  tiles  are  next  cut  off  to  such  lengths  as  are  wanted,  and  carried  away  by 
an  endless  web,  whence  they  are  transferred  by  boys  to  the  drying  shelves. 

Flat  tiles,  for  sole  pieces  to  draining  tiles,  are  formed  in  nearly  the  same  manner, 
being  divided  into  two  portions  while  passing  through  the  moulds ;  the  quantity  of  clay 
used  for  one  draining  tile  being  as  much  as  for  two  soles. 

The  method  of  making  bricks  in  the  vicinity  of  London  differed  from  that  of  almost 
all  other  places,  because  the  material  there  employed  is  not  pure  clay,  but  a  loam  of 
a  slightly  cohesive  nature,  which  will  not  admit  of  its  being  used  in  the  natural 
gtate  and  burned  in  close  kilns  with  coal ;  but  with  an  admixture  of  ashes  it  becomes 
sufficiently  tenacious  to  be  formed  into  bricks,  by  inducing  a  slight  semi-fusion.  But 
the  coal-ashes  are  also  of  advantage  in  the  process  of  burning,  because  they  enable  the 
fire  to  spread  gradually  from  the  lower  tiers,  through  the  whole  mass  in  the  kiln  or 
clamp,  and  thus  obviate  the  effect  of  an  intense  partial  heat,  where  distinct  coal  fires 
are  trusted  to  alone,  whereby  the  bricks  nearest  it  get  vitrified  and  glazed. 

The  brick  kilns  and  clamps  round  London,  and  other  large  cities,  which  are  fired 
with  the  breeze-rubbish  collected  from  dust  holes,  that  contain  the  refuse  of  kitchens, 
&c.,  emit,  in  consequence,  most  unpleasant  effluvia ;  but  brick-kDns  fired  with  clean 
coke  or  coals,  give  out  no  gases  of  a  more  noxious  nature  than  common  household  fires. 
The  consideration  of  this  subject  was  closely  pressed  upon  my  attention  on  being  con- 
sulted concerning  an  injunction  issued  by  the  chancellor  against  a  brick  clamp  in  the 
Isle  of  Wight,  fired  with  clean  coke  cinders  from  the  steam-engine  furnace  at  Ports- 
mouth Dock  Yard.  The  bricks  being  of  the  description  called  sand-stock,  were  of 
course  made  in  moulds  very  slightly  dusted  with  sand,  to  make  them  fall  freely  out. 
The  sand  was  brought  from  Portsmouth  harbor,  and  on  being  subjected  to  a  degree 
of  heat,  more  intense  certainly  than  it  would  suffer  in  the  clamp,  was  discovered  by  two 
chemical  witnesses  to  give  out  traces  of  hydrochloric  acid.  Not  content  with  this 
trivial  indication,  the  said  chemists,  in  their  evidence  before  the  courts  of  law,  paraded 
a  train  of  goblin  gases,  as  the  probable  products  of  the  pre-adjudicated  clamp. 

As  it  is  well  known  to  the  chemist  that  common  salt  strongly  ignited  in  contact  with 
moist  sand  will  emit  hydrochloric  acid,  there  was  nothing  remarkable  in  the  above 


BRITANNIA  TUBULAR  BRIDGK 


2V9 


observation,  but  I  ascertained  that  the  sand  with  which  the  moulds  were  strewed  would 
give  out  no  hydrochloric  acid,  at  a  heat  equal  at  least  to  what  the  bricks  were  exposed 
to  in  a  clamp  10  or  12  feet  high,  and  fired  at  its  bottom  only  with  a  layer  of  cindera 
3  or  4  inches  thick.  But  I  further  demonstrated  that  the  entire  substance  of  the  brick 
with  its  scanty  film  of  sand,  on  being  exposed  to  ignition  in  a  suitable  apparatus,  gave 
out— not  hydrochloric  or  any  other  corrosive  acid,  but  ammonia  gas.  Hence,  the 
allegations  that  the  clamp  set  forth  a  host  of  acid  gases  to  blight  the  neighbouring 
trees,  were  shown  to  be  utterly  groundless ;  on  the  contrary,  the  ammonia  evolved  from 
the  heated  clay  would  act  beneficially  upon  vegetation,  while  it  was  too  small  in  quantity 
to  annoy  any  human  being.  A  few  yards  to  leeward  of  a  similar  clamp,  in  full  activity, 
I  could  perceive  no  offensive  odour.  All  ferruginous  clay,  when  exposed  to  the  atmo- 
sphere, absorbs  ammonia  from  it,  ^nd  of  course  emits  it  again  on  being  gently  ignited. 
It  is  a  reproach  to  science  when,  as  in  the  above  case,  it  lends  itself  to  judicial 
prejudice  and  oppression. 

Messrs.  Whalley  and  Lighloller  have  patented  apparatus  for  manufacturing  bricks 
and  tiles,  which  combines  the  pug  mill,  pressing  cylinder,  screens  and  die-plate  all 
in  one  machine ;  thereby  effecting  great  economy  m  time  and  labour,  and  also  in 
the  cost  of  the  machinery  itself     The  combination  alone  is  claimed. 

BRIMSTONK     {Soufre,  Fr. ;   Sckwefel,  Germ.)    Sulphur,  which  see. 

BRITANNIA  TUBULAR  BRIDGE  (opening  of  the).  The  opening  of  this  mag- 
nificent structure,  looked  forward  to  with  so  much  interest,  came  oft'  on  the  5th  of  March, 
1849,  at  dawn  with  the  grandest  success.  At  precisely  seven  o'clock,  the  adventurous 
convoy,  progressing  at  a  speed  of  seven  miles  an  hour,  was  lost  sight  of  in  the  recess  of  the 
vast  iron  corridor.  Instead  of  being  driven  through  with  a  dispatch  indicative  of  a 
desire  on  the  part  of  those  who  manned  it  to  get  in  and  out  with  the  utmost  expedition, 
the  locomotives  were  propelled  at  a  slow  and  stately  pace,  with  a  view  of  boldly  proving 
by  means  of  a  dead  weight  the  calibre  of  the  bridge  at  every  hazard.  The  total  weight 
of  the  locomotives  was  90  tons.  The  appearance  of  the  interior  of  the  tube  during  the 
experiment  was  of  a  novel  and  remarkable  character.  The  locomotives  were  brought 
to  a  standstill  in  the  centre  of  each  of  the  great  spans,  without  causing  the  slightest 
strain  or  deflection.  The  first  process,  that  of  goin^  through  the  tube  and  returning, 
occupied  altogether  10  minutes.  The  second  experimental  convoy  that  went  through 
consisted  of  24  heavily  laden  waggons  filled  with  huge  blocks  of  Brymbo  coal,  in  all, 
engines  included,  an  aggregate  weight  of  300  tons.  This  was  drawn  deliberately 
througli,  at  the  rate  of  from  eight  to  ten  miles  an  hour,  the  steam  working  at  quarter 
power.  During  the  passage  of  this  experimental  train  through  the  tube,  a  breathless 
silence  prevailed  until  the  train  rushed  out  exultingly,  and  with  coloui-s  flying,  on 
the  other  side  of  the  tube,  when  loud  acclamations  arose,  followed  at  intervals  by  the 
rattle  of  artillery  down  the  Straits.  Upon  the  return,  which  occupied  about  seven 
minutes,  similar  demonstrations  ensued,  and  during  the  progress  of  the  train  those  who 
stood  upon  its  top  to  ascertain  any  possible  vibration,  reported  they  could  detect  no 
sensible  deflection.  An  ordeal  stronger  still  was  then  resorted  to  ;  a  train  of  200  tons 
of  coals  was  allowed  to  rest  with  all  its  weight  for  two  hours  in  the  centre  of  the 
Carmarthenshire  tube,  and  at  the  end  of  the  time,  on  the  load  being  removed,  it  was 
found  to  have  caused  a  deflection  of  only  four-tenths  of  an  inch.  It  is  remarkable  that 
this  amount  of  deflection  is  not  so  much  as  one  half  hour  of  sunshine  would  produce 
upon  the  structure,  it  being  moreover  calculated  with  confidence  that  the  whole  bridge 
might  with  safety,  and  without  injury  to  itself^  be  deflected  to  the  extent  of  13  inches. 
These  loads,  it  is  most  material  to  remember,  are  immensely  more  than  the  bridge 
will  ever  be  called  on  to  bear  in  the  ordinary  run  of  traffic,  though  the  engineers  are 
of  opinion  that  it  would  support  with  ease,  and  without  much  show  of  deflection,  a  dead 
weight  on  its  centre  of  1,000  tons.  Twelve  miles  an  hour  is  the  limit  of  speed  at  which 
Mr.  Stephenson  intends  that  trains  shall  at  first  go  through,  more  particularly  as  there 
are  sharp  curves  at  the  termini  of  the  tube. 

The  effect  of  the  recent  hurricane  on  the  calibre  of  the  tube  has  proved  that  its 
lateral  surface  strength  is  sufficient,  and  far  more  than  sufficient,  to  resist  the  strongest 
wind.  It  is  calculated  that,  taking  the  force  of  the  wind  at  50  lbs.  on  the  square  foot, 
an  excessive  supposition,  the  resistance  offered  by  the  bridge  would  be  300  tons  X  2  = 
600  tons,  which  is  not  two  thirds  of  its  own  weight.  The  wind  going  at  80  iniles  an 
hour  the  rush  of  a  hurricane  would  only  press  in  the  ratio  of  128  tons  on  the  side.  It 
is  intended,  when  both  tubes  are  up,  to  brace  them  together  with  stays,  so  as  to  counteract 

any  possible  oscillation.  ^  ,        ,  .  ,  i  ^        i.m 

The  great  work  has  now  been  four  years  m  hand,  and  is  nearly  complete,  while 

Telford*s  suspension  bridge  took  eight  years. 

The  floating  and  actual  transference  of  the  tubes  have  occupied  since  June  last,  a  short 

period,  when  the  bulk  of  the  fabric  is  taken  into  consideration.     Great  fears  wera 


380 


it 


i;!! 


I 


BRONZE. 


entertained  for  its  safety  during  the  late  gales,  from  the  recollection  in  this  part  of 
the  country  of  the  damage  done  to  Telford's  suspension  bridge. 

BRITISII  GUM.  The  trivial  name  given  to  starch,  altered  by  a  slight  calcination 
m  an  oven,  whereby  it  assumes  the  appearance  and  acquires  the  properties  of  gum, 
being  soluble  in  cold  water,  and  forming  in  that  state  a  paste  well  adapted  to  thicken 
the  colours  of  the  calico  printer.     See  Dextrine  and  Starch. 

BROMINE,  one  of  the  archseal  elements,  which  being  developed  from  its  combination! 
at  the  positive  pole  of  the  voltaic  circuity  has  been  therefore  deemed  to  be  idio-electro- 
positive  like  oxygen  and  chlorine.  It  derives  its  name  from  its  nauseous  smell,  BooS/ioj, 
mtor.  It  occurs  m  various  saline  springs  on  the  continent  of  Europe,  in  those  of  Ashby 
de  la  Zouche,  and  some  others  in  England ;  in  the  lake  Asphaltites,  in  sponges,  in  some 
marine  plants,  in  an  ore  of  zinc,  and  in  the  cadmium  of  Silesia.  At  ordinary  tempera 
tures  It  IS  liquid,  of  a  dark  brown  colour  in  mass,  but  of  a  hyacinth-red  in  thin  layers. 
Its  smell  IS  rank  and  disagreeable,  somewhat  like  that  of  chlorine.  It  has  a  very  caustic 
taste.  Its  specific  gravity  is  2-966.  Applied  to  the  skin  it  colours  it  deep  yellow  and 
corrodes  it.  One  drop  put  within  the  bill  of  a  bird  suffices  to  kiU  it  It  combines  with 
oxygen  with  feeble  affinity,  forming  bromic  acid.  Its  attraction  for  hydrogen  being  far 
more  energetic,  it  forms  therewith  a  strong  acid,  the  hydrobromic. 

Bromine  dissolves  very  sparingly  in  water,  but  it  is  very  soluble  in  alcohol  and  ether. 
It  combines  with  carbon,  phosphorus,  sulphur,  and  chlorine,  as  well  as  with  most  of  the 
metals.  Jrom  its  scarcity  it  has  not  hitherto  been  applied  to  any  purpose  in  the  arts, 
except  photography;  but  it  is  supposed  to  possess  powerful  discutient  effects  upon 
scrotulous  and  other  glandular  tumours,  whence  the  waters  containing  it  are  pre- 
scnbed  as  an  internal  and  external  remedy  in  such  forms  of  disease. 
,..^^^.^2^  -.^  compound  metal  consisting  of  copper  and  tin,  to  which  sometimes  a 
little  zmc  and  lead  are  added.  This  alloy  is  much  harder  than  copper,  and  was 
employed  by  the  ancients  to  make  swords,  hatchets,  «fec.,  before  the  method  of  working 
iron  was  generally  understood.  The  art  of  casting  bronze  statues  may  be  traced  to  the 
most  remote  antiquity,  but  it  was  fii-st  brought  to  a  certain  degree  of  refinement  by 
Iheodoros  and  Roecus  of  Samoa,  about  700  yeai-s  before  the  Christian  era,  to  whom  the 
invention  of  modelling  is  ascribed  by  Y\\\\^\  The  ancients  were  well  aware  that  by 
alloying  copper  with  tin,  a  more  fusible  metal  was  obtained,  that  the  process  of  casting 
was  theretore  rendered  easier,  and  that  the  statue  was  harder  and  more  durable  ;  and 
yet  they  frequently  made  them  of  copper  nearly  pure,  because  they  possessed  no  means 
of  determining  the  proportions  of  their  alloys,  and  because  by  their  mode  of  managing 
the  fire,  the  copper  became  refined  in  the  course  of  melting,  as  has  happened  to  many 
founders  in  our  own  days.  It  was  during  the  reign  of  Alexander  that  bronze  statuary 
received  its  greatest  extension,  when  the  celebrated  artist  Lysippus  succeeded  by  new 
processes  of  moulding  and  melting  to  multiply  groups  of  statues  to  such  a  degree  that 
Fhny  called  him  the  7noh  of  Alexander.  Soon  afterwards  enormous  bronze  colossuses 
were  made,  to  the  height  of  towers,  of  which  the  isle  of  Rhodes  possessed  no  less  than  one 
hundred-  The  Roman  consul  Mutianus  found  3,000  bronze  statues  at  Athens,  3,000  at 
Rhodes,  as  many  at  Olympia  and  at  Delphi,  although  a  great  number  had  been  previouslv 
carried  off  from  the  last  town.  ^ 

In  forming  such  statues,  the  alloy  should  be  capable  of  flowing  readily  into  all  the 
parts  of  the  mould,  however  minute ;  it  should  be  hard,  in  order  to  resist  accidental 
blows,  be  proof  against  the  influence  of  the  weather,  and  be  of  such  a  nature  as  to 
acqmre  that  greenish  oxidized  coat  upon  the  surface  which  is  so  much  admired  in  the 
antique  bronzes  called  ^patina  antiqucu  The  chemical  composition  of  the  bronze  alloy 
18  a  matter  therefore  of  the  fii-st  moment  The  brothers  Keller,  celebrated  founders  in 
the  time  of  Louis  XIV.,  whose  chefs-d'oeuvre  are  well  known,  directed  their  attention 
towards  this  point,  to  which  too  little  importance  is  attached  at  the  present  day.  The 
statue  of  Desaix  in  the  place  Dauphine,  and  the  column  in  the  Place  Vendome,  are 
noted  specimens  of  most  defective  workmanship  from  mismanagement  of  the  alloys  of 
^,.*^-"  ^^^y  *^^  composed.  On  analysing  separately  specimens  taken  from  the  bas- 
rehefs  of  the  pedestal  of  this  column,  from  the  shafts  and  from  the  capital,  it  was  found 
that  the  first  contained  only  6  per  cent  of  alloy,  and  94  of  copper,  the  second  much 
less,  and  the  third  only  0-21.  It  was  therefore  obvious  that  the  founder,  unskilful  in  the 
melting  of  bronze,  had  gone  on  progressively  refining  his  alloy,  by  the  oxidizement  of 
the  tin,  till  he  had  exhausted  the  copper,  and  that  he  had  then  worked  up  the  refuse 
BConaB  in  the  upper  part  of  the  column.  The  cannons  which  the  government  furnished 
him  for  casting  the  monument  consisted  of — 

Copper    -  -  -     89-360 

Tin  -  -  -    lC-040 

Lead        -  _  .       0102 

Silver,  zinc,  iron,  and  loss      0-498 


100-000 


■bi^^:. 


BRONZE.  281 

to'^nr"tl?i°f!Hf  ^^^  ''""""^^  bas-reliefs  was  so  ill-executed,  that  the  chiselers  employed 
besfZ  sooonn  f       removed  no  less  than  70  tons  of  bronze,  which  was  given  tC 

Copper 
Tin 
Zinc 
Lead 


No.  1. 

No.  2. 

No.  3. 

The  mean. 

91-30 

91-68 

91-22 

91-40 

1-00 

2-32 

1-78 

1-70 

6-09 

4-93 

6-67 

6-63 

1-61 

1-07 

1-43 

1-37 

10000 


100  00 


100-00 


100-00 


The  analysis  of  the  bronze  of  the  statue  of  Louis  XV.  was  as  follows  :- 

ZhiT""     ?0-30     ^^' 'P^'^^'^  ^*^*^y  ^as  8-482. 
Tin  4-10 

Lead         3*15 


100-00 

fa  tt,e  hundred.o^  .i„c  be  aSdet  '™ey^?„'Lt1  LC'a  Ltlo^'zeZr  'xf  T 
Of  the  Kellers  is  famous  for  this  effect  Th^  m«^oi\,u  ij  i.  ^^onze  tint.  The  alloy 
successive  stamps  of  the  nress  and  ^  J^!  lH  '^''"^^  ^f  subjected  to  three  or  four 
plunged  into  cold  water.  ^      '     ^  ^  '"^'""^  ^^^^^^^  '^'^  ^ow  by  being  heated  and 

alby  L'sTfi^Llmtergr:!nT^^^^^  'fSTfJ''  '''  P^^-^ copper  78,  tin  22.  Thi. 
added  are  rather  prejud  cLT  and  Z^C^fn^r"  c    .^^^^  The  other  metals  sometimes 

English  bells  conLt^fsoilfer^^^^^  of  the  founders.     Some  of  the 

jn^^sucb  large  quantity  is  apf  I  ^^  tl^^^^^^^i  .^  ':^^fZ 

fo^eiiXTr^^er/^^^^  v^  thl^'^^a^J^T  "^-"^  f^  ^-^  ^-"^  ^^^^ ^s 
gongs,  from  the  word  /^Aou^l  whichT^^^tebeTr^^^^^^^^  °^'^.^'^'  '\'^  «^^  """^ 
tain  nothing  hut  copper  and  tin  •  in  the  nronortS.r  78^  ?  v  ^r^  '^'''^"  ^'^^^  ^^^^  «««- 
the  latter.  Their  specificTavitvTs  8  8 1 5  ^T v  if  ^^  5  ^^^  ^''™^''  "^^«^  ^^^  22  of 
glass,  but  by  being  pCed  at  a  c^«r"^Pd  hit  •  "^^''^Z^'"'  ""^'^^  '^''  ^'  ^'  ^"^'^^  ** 
iwo  discs  of  iron^o  keen  it  insSn/^r^^^^^  water  and  confined  between 

consist  of  80  parts  coppe?  and  20  tin ''  ''  ^''°°'''  '""^^  ^"^  malleable.    The  cymbal. 

ror^Xh  t^wo^wl^atSt  Krc"^^^  ''V'' ^^  --"--  P-ess, 

lips  tempered  in  the  same  wa?    Ancient  warlike  wPonn'rT  ^"'*  ^^""'^^"^  ^'""^^  '^^ 
pounded;  swords  were  formS of  S^Hopper  and ToF^ 
balistffi  consisted  of  97  copper,  and  3  tinf      '  ^         ""  ^^  P^'*''  ^^«  ^P"^?^  ^^ 

Cannon  metal  consists  of  about  90  or  91  copper,  and  10  or  Q  nf  lir,      t?        *i. 
mcnts  of  Papacino-d'Antony,  made  at  Turin  in  1770  if  VnnL       k*  .  ^u""""  ^^^  ^"^P^"' 
alloy  for  great  guns  is  from  12  to  14  parts  of  tn  to  100  y^^^^''  ^^^^  ^^%  »«»st  proper 
tiUiere  concluded  from  his  experimXll'at  Lua^^^^^^  "^T^i 

peZ^t^:r:^;;/J:Z'^^^^^^  ^-"y  o^^--,  and  take 

pasty  consistencrdoes  not  n'X  -  ^h«  I    '        ''''P^''  """^  "''"^^  ^'  ^'^^^  ^"^^^  «<*  » 

liable  to  cmck  in'coolfn  "  Ld  is  too  t  n^.h  ''T'  ''  Tr  '"^  ^^^"'^  ^°°  '""ch  amalgam,  is 
the  q..antity  of  zinc  iicr^nsed  to  Zi-p  f.  *?°,  'f '  ?"  '^'  ''^'''^'  *^^  '^^  t"^"^^- '  W^re 
suitable  to[he  eiWer    Tfou^^^^^^  ^^'^''^  '}  ^^'^"''^  '«^^  '^'^  J^llow  color 

for  making  sucnrname^tKoi'ze  anS  ^'"'  ^^'^?'^^'*  '^  P-'-«»>»<^ 

the  best,  as  they  unite  clo«;eness  of^\nZi,h^^  .1  ^"""^^^  "^  proportions  are  probably 
18,  tin  3  or  L  lead  ^  orS  Tn  thSv^  v  u^  '''^''  ^°^^  ^^^Mes.  Copper  82,  zini 
minishcd  and\he  density  [s'i/  conta.ns  met  lead,  the  tenaci.y  is  di- 

AnothcT  alloy,  which  i^Ia^d  to  rrSl  7     -.    '^P^i^^^^^We  for  pieces  of  small  dimensions 
tily  of  gold    h^s  the  followin/.?^^^^^   ^r     '  ^'''''"^  only  two  thirds  of  the  ordinary  quan- 
lead,  0.^24.'  ^^  composition:  copper,  82-257;  zinc,  17-481  ;  tin,  0^238, 

ti^ef:iCl^'j^^^^^^^^^  and  otherobjects  madefrom  these  alloys  by 

(binoxalate  of  nofaih  \  areTn  hi  ^-  ^  of  sal-ammoniac,  and  half  a  drachm  of  salt  of  jJ,rrel 

less  Tinegi     A  hat  nencl  be^nlT  ^^^  '"       - '"  """'"  '^'^''''''  (^"^'''^>  "^^^'^' 
Vol.  I  ^  ^  ^'^^^^  ""*"  ^^^  ^°^"t'«n>  ^^^  Pressed  gently  betweea 

^  LI 


^M 


: 


i 


u^ 


h: 


282 


BRONZE. 


the  fingers,  is  to  be  rubbed  equaDy  over  the  clean  surface  of  the  object,  slightly  wanned 
in  the  sun  or  at  a  stove ;  and  the  operation  is  to  be  repeated  tiU  the  wished-for  shade  is 

obtained.     (See  Gilding.)  * ..     i        c*-^ 

The  bronze  founder  ought  to  melt  his  metals  rapidly,  m  order  to  prevent  the  loss  ol  tin, 
zinc,  and  lead,  by  their  oxydizement.  Reverberatory  furnaces  have  been  long  used  for 
this  operation  ;  the  best  being  of  an  elliptical  form.  The  furnaces  vn\i\  dome  tops  are 
employed  by  the  bell-founders,  because  their  alloy  being  more  fusible,  they  do  not  require 
60  intense  a  heat ;  but  they  also  would  find  their  advantage  in  using  the  most  rapid  mode 
of  fusion.  The  surface  of  the  melting  metals  should  be  covered  with  small  charcoal,  oi 
coke ;  and  when  the  zinc  is  added,  it  should  be  dexterously  thrust  to  the  bottom  of  the 
melted  copper.  Immediately  after  stirring  the  melted  mass  so  as  to  incorporate  its  ingre- 
dients, it  should  be  poured  out  into  the  moulds.  In  general,  the  metals  most  easily  al- 
tered by  the  fire,  as  the  tin,  should  be  put  in  last.  The  cooling  should  be  as  quick  as 
possible  in  the  moulds,  to  prevent  the  risk  of  the  metals  separating  from  each  other  in 
the  order  of  their  density,  as  they  are  very  apt  to  do.  The  addition  of  a  little  iron,  m  the 
form  of  tin-plate,  to  bronze,  is  reckoned  to  be  advantageous. 

One  part  of  tin,  and  two  parts  of  copper  (nearly  one  atom  of  tin  and  four  of  copper,  or 
more  exactly,  100  parts  of  tin,  and  215  copper),  form  the  ordinary  speculum  metal  of  re- 
flecting' telescopes,  which  is  of  all  the  alloys  the  whitest,  the  most  brilliant,  the  hardest, 
and  the  most  brittle.  The  alloy  of  1  part  of  tin,  and  10  of  copper  (or  nearly  one  atom 
of  the  former  to  eighteen  of  the  latter),  is  the  strongest  of  the  whole  series. 

Ornamental  objects  of  bronze,  after  being  cast,  are  commonly  laid  upon  red-hot  coals 
till  they  take  a  dull  red  heat,  and  are  then  exposed  for  some  time  to  the  air.  The  sur- 
face is  thereby  freed  from  any  greasy  matter,  some  portion  of  the  zinc  is  dissipated,  the 
alloy  assumes  more  of  a  coppery  hue,  which  prepares  for  the  subsequent  gilding.  The 
black  tinge  which  it  sometimes  gets  from  the  fire  may  be  removed  by  washing  it  with  a 
weak  acid.  It  may  be  made  very  clean  by  acting  upon  it  with  nitric  acid,  of  specific 
gravity  1-324,  to  which  a  little  common  salt  and  soot  have  been  added,  the  latter  being 
of  doubtful  utility ;  after  which  it  must  be  well  washed  in  water,  and  dried  wif h  rags  or 

saw-dust.  ,  r  1 

Bronzing  is  the  art  of  giving  to  objects  of  wood,  plaster,  fee,  such  a  surface  as  makes 
them  appear  as  if  made  of  bronze.  The  term  is  sometimes  extended  to  signify  the  pro- 
duction of  a  metallic  appearance  of  any  kind  upon  such  objects.  They  ought  first  to  be 
smeared  over  smoothly  with  a  coat  of  size  or  oil  varnish,  and  when  nearly  dry,  the  me- 
tallic powder  made  from  Dutch  foil,  gold  leaf,  mosaic  gold,  or  precipitated  copper,  is  to 
be  applied  with  a  dusting  bag,  and  then  rubbed  over  the  surface  with  a  linen  pad ;  or  the 
metallic  powders  may  be  mixed  with  the  drying  oil  beforehand,  and  then  applied  with  a 
brush.  Sometimes  fine  copper,  or  brass  filings,  or  mosaic  gold,  are  mixed  previously  with 
some  pulverized  bone-ash,  and  then  appUed  in  either  way.  A  mixture  of  these  powders 
with  mucilage  of  gum  arable  is  used  to  give  paper  or  wood  a  bronze  appearance.  The 
surface  must  be  afterward  burnished.  Copper  powder  precipitated  by  clean  plates  of  iron, 
from  a  solution  of  nitrate  of  copper,  after  being  well  washed  and  dned,  has  been  em- 
ployed  in  this  way,  either  alone  or  mixed  with  pulverized  bone-ash.  A  finish  is  given  tft 
vorks  of  this  nature  by  a  coat  of  spirit  varnish. 

A  white  metallic  appearance  is  given  to  plaster  figures  by  rubbmg  over  thein  an  amaU 
gam  of  equal  parts  of  mercury,  bismuth,  and  tin,  and  applying  a  coat  of  varnish  over  it. 
The  iron-colored  bronzing  is  given  by  black  lead  or  plumbago,  finely  pulverized  and 
washed.  Busts  and  other  objects  made  of  cast  iron  acquire  a  bronze  aspect  by  being 
well  cleaned  and  plunged  in  solution  of  sulphate  of  copper,  whereby  a  thm  film  of  this 

metal  is  left  upon  the  iron.  «      .  i  »       •  r 

Copper  acquires  by  a  certain  treatment  a  reddish  or  yellowish  hue,  m  consequence  ot 
a  little  oxide  being  formed  upon  its  surface.  Coins  and  medals  may  be  handsomely 
bronzed  as  follows:  2  parts  of  verdigris  and  1  part  of  sal  ammoniac  are  to  be  dis- 
solved in  vinegar ;  the  solution  is  to  be  boiled,  skimmed,  and  diluted  with  water  till  it  has 
only  a  weak  metallic  taste,  and  upon  further  dilution  lets  fall  no  white  precipitate.  This 
solution  is  made  to  boil  briskly,  and  is  poured  upon  the  objects  to  be  bronzed,  which  are 
previously  made  quite  clean,  particularly  free  from  grease,  and  set  in  another  copper  pan. 
ftiis  pan  is  to  be  put  upon  the  fire,  that  the  boiling  may  be  renewed.  The  pieces  under 
operation  must  be  so  laid  that  the  solution  has  free  access  to  every  point  of  their  surface. 
The  copper  hereby  acquires  an  agreeable  reddish  brown  hue,  without  losing  its  lustra 
But  if  the  process  be  too  long  continued,  the  coat  of  oxide  becomes  thick,  and  makes  the 
objects  appear  scaly  and  dull.  Hence  they  must  be  inspected  every  five  minutes,  and 
be  taken  out  of  the  solution  the  moment  their  colour  arrives  at  the  desired  shade.  If 
the  solution  be  too  strong,  the  bronzing  comes  off  with  friction,  or  the  copper  gets  covered 
with  a  white  powder,  which  becomes  green  by  exposure  to  air,  and  the  labour  is  con- 
sequently lost.  The  bronzed  pieces  are  to  be  washed  with  many  repeated  waters,  and 
carefully  dried,  otherwise  they  would  infallibly  turn  green.    To  give  fresh-made  bronze 


BRONZE. 


283 


-n^/  l^!V  *r  u^"*^  appearance,  three  quarters  of  an  ounce  of  sal  ammoniac,  and  a  drachm 
and  a  half  of  binoxalate  of  potash  (salt  of  sorrel)  are  to  be  dissolved  in  a  quart  of  vinegar. 
1  .  ^  ?n  •?"  ^^'•^'^'■"sh  moistened  with  this  solution  is  to  be  rubbed  over  the  clean  bri-ht 
metal,  till  its  surface  becomes  entirely  dry  by  the  friction.  This  process  must  be  repeat- 
ed several  times  to  produce  the  fuU  effect ;  and  the  object  should  be  kept  a  litle  warm 

nvpJ'nr^'T'l!'^  """^  f^u''"^  ^^''^'^  *=°^«''  ^y  """^^i"?  »^  ^»t^  *  s^l«tio"  oC  the  common 
liver  of  sulphur,  or  sulphuret  of  potash. 

»rIK  ^*'*"^^^  ;^^.  ^^'t  *o  ^'•onze  their  copper  vessels  bv  taking  2  ounces  of  verdi- 
gris,  2  ounces  of  cinnabar,  5  ounces  of  sal  ammoniac,  and  5  ounces  of  alum,  all  in 
powder   making  them  into  a  paste  with  vinegar,  and  spreading  this  i.retty  thick !ke  a 

S;£lL'oU7a  firVluMrb^cTer^^r'"^^  ^^^  P--  '^  ^^^-    '«  b^helfa  litti: 

TfiPr  wZh  .-7  •  '  .  ^-  "If  ""'formly  heated.  It  is  next  cooled,  washed,  and  dned ; 
after  which  it  is  treated  in  the  same  way  once  and  again  till  the  wished  for  color  is 
obtained.  An  addition  of  sulphate  of  copper  makes  the  color  inclinrmore  to  che^nut 
brown,  and  of  borax  more  to  yellow.     It  is  obvious  that  the  cinnabarroTc^s  a  thin  c^t 

n J^f'bi  '^^  ^PP^^^-^lfe  of  antique  bronze  to  modem  articles,  we  should  dissolve  1 
part  of  sal  ammoniac,  3  parts  of  cream  of  tartar,  and  6  parts  of  common  TaU  in 
12  parts  of  hot  water,  and  mix  with  the  solution  8  parts  of  a  solSn  of  n" tra  e 
of  copper  of  specific  gravity  M60.  This  compound,  when  applied  repeatSlly  1^  a 
moderately  damp  place  to  bronze,  gives  it  in  a  short  time  ^durable  gr^n  coaL 
which  becomes  by  degrees  very  beautiful.  More  salt  gives  it  a  jeUov^ish  tll^e  Lss 
mirdant     '      '  ^  ^^'^'  ^'^^''^''  "^  '^^  ^^^^^^-^'^^^  accelerates  the  operation  of  ^e 

Broxze  Powders,  an  article  much  used  of  late  in  the  decorative  painting  of  houses.  Ac 
^ey  are  prepared  of  every  various  shade,  from  that  of  bright  gold  to  oraZ^dark 
copper,  emerald  green.  Ac   Pale  gold  is  produced  from  an  alloy  of  13i  of  copper  and 
21  of  zmc:  cnmson  metallic  lustre-from  copper:  do.  paler,  copper  Ld  a?e?v  iiUle 
one:  green  bronze  with  a  proportion  of  verdigris:  another  fine  orange  by  ll/ Upe^ 

o??hAw"''  tT'- '■"  ^  ^*  '^PP'':  ^^^  2i  zinc:  a  beautiful  pale  gold  from  an  aZ^ 
of  the  two  metals  in  atomic  proportions.     See  Atomic  Weights  ^ 

U^t!iA-^.'^-^'^T^t^  '"*''  r'^  ?"^  ^^*^^«  "^'^^  <^»^ef"l  annealing,  and  these  are 
levigated  into  impalpable  powde^^along  with  a  film  of  fine  oil  to  prevent  oxidiztmenL 

LtrTwV^y^^riremer.'^^  ""^^^^^^^^  -«""^-^-  ^^  ^-  ---^-^ 
^r^oll^lr'"''  0/ gun^arrel,  and  other  arms.-By  this  process,  the  surface  of  several 

!^i  frL  r.!T  ''T'f^^'^  '^'"'"'-  ^'"°'^"  ^°^°"-     "^^'^  preparation,  which  prt.tects  the 
^  from  rust,  and  a  so  improves  its  appearance,  is  chiefly  employed  for  the  barrels  of 

tJI  2'"^;^?%*"ru  °*'^'^.'''  "'^^^  to  conceal  the  fire-arms  from  the  eame  and  the  enemy, 
^e  browi    round  """"  ''        Damascus,  in  which  dark  and  bright  lines  run  through 

^   This  operation  consists  in  producing  a  very  thin  uniform  film  of  oxyde  or  rust  upon  the 

Urvamlr'"^  *  ^^^ ''"  '"'^^'^  ^^  '*"^^''*=  '^*''  °''^'"  '*'  *"■  ^'^^^^"S  '^  ^'^^^  »^^1- 

Several  means  may  be  employed  to  produce  this  rust  speedily  and  well.  The  effect 
fJ^J  ^^JS^^l""^  by  enclosing  the  barrels  in  a  space  filled  with  the  vapor  of  muriatic 
•cid.  Moistening  their  surface  with  dilute  muriatic  or  nitric  acid,  will  answer  the  same 
purpose.  But  the  most  common  material  used  for  browning,  is  tho  butter  or  chloride 
wTJTr//  if  •'  on  account  of  Us  being  subservient  to  this  purpose,  has  been  called 
J^tng  salt  It  IS  mixed  uniformly  with  olive  oil,  and  rubbed  upon  the  iron  sli-htly 
heated ;  which  is  afterwards  exposed  to  the  air,  till  the  wished-for  degree  of  brownii-  ^ 
The  hrntn  t  ^T  Tk^T'  ''  '"^f.^  ^?  ^""^  '^'  ^"^'°^°»y'  '^  *l"'<^ken  its  ope^ah^on 
polished,  either  by  the  steel  burnisher,  or  rubbed  with  white  wax,  or  varnished  with  a 
•olution  of  2  ounces  of  shellac,  and  three  drachms  of  dragons  blood,  inl^n^^oTspii^ 

The  following  process  may  also  be  recommended :  Make  a  solution  with  half  as 

Tonnotl  ^r^l^'h'f  }  *""  ''''''''^f  ^"^^^^  'P^"*  «^  ""'^^^  1  «"»««  of  spirit  of  wine, 
Im  fin  .ll'".f  '  '?PP'''  ^""^  L?^"^^  «^  "°«t"^«  o^  ^^^  i«  «o  mSch  water  a^ 
filed  ^hMTk  5  if  "^  w  ""/^f  "'^-  J^""  ^^  ^^^^•l  *^  ^«  browned  must  first  of  all  be 
med  and  polished  bright,  and  then  rubbed  with  unslaked  lime  and  water  to  clear  away 

with  t  W^  T?-*^'  touch-hole  must  be  filled  with  wax.  The  barrel  is  then  to  be  ^ubbed 
moi«tin!^ '?•'"'' nPP^"^.^  ^'''^''  ^^^  «^  *  «P«»g«'  *»U  the  whole  surface  be  equally 
ThTannll;..^  '"  f  .7'?  *^.j*«°<i24  hours,  and  is  then  scrubbed  with  a  stiflf  brus^ 
Ihe  application  of  the  liquid  and  the  brushing  may  be  repeated  twice  or  oftener 

202 


284 


BRONZE. 


BROWN  DYE. 


285 


I  i' 


till  the  iron  acquires  a  fine  brown  colour.  After  the  last  brushing,  the  ^aijel  must  be 
washed  with  plenty  of  boiling  water,  containing  a  little  potash ;  then  washed  with  clean 
water,  dried,  rubbed  with  polishing  hard  wood  and  coated  with  shel-lac  varnish,  for 
which  purpose  the  barrel  must  be  heated  to  the  boding  point  of  water.     It  is  finally 

polished  with  a  piece  of  hard  wood.  „i„v„*^  ^t  «„««^^ 

Storch  recommends  to  make  a  browning  solution  with  1  part  of  sulphate  of  copper, 

one  third  of  a  part  of  sulphuric  ether,  and  4  parts  of  distilled  water 

To  dve  the  damask  appearance,  the  barrel  must  be  rubbed  over  first  with  very  dilute 

aquafortis  and  vinegar,  mixed  with  a  solution  of  blue  vitriol ;  washed  and  dried  and 

Abed  with  a  hard  brush  to  remove  any  scales  of  copper  which  may  be  precipitated 

upon  it  from  the  sulphate.  i     j       ui    v  a 

Statues,  vases,  bas-reliefs,  and  other  objects  made  of  gj-psum  may  be  durably  bronzed, 
and  bear  exposure  to  the  weather  better  than  after  the  ordinary  oil-varnish,  by  the 
following  process:— Prepare  a  soap  from  linseed  oil,  boiled  with  caustic  soda  ley, 
to  which  add  a  solution  of  common  salt,  and  concentrate  it  by  boiling,  till  it  become, 
somewhat  granular  upon  the  surface.     It  is  then  thrown  upon  a  piece  of  linen  cloth^ 
and  strained  with  moderate  pressure.     What  passes  through  is  to  be  diluted  with 
boiling  water,  and  again  filtered.     On  the  other  hand,  4  parts  of  blue  vitriol  and  1 
part  of  copperas  ar?to  be  dissolved  separately  in  hot  water.    This  solution  is  tobe 
poured  slowly  into  the  solution  of  soap,  as  long  as  it  occasions  any  precipitate.     Itua 
Socculent  matter  is  a  mixture  of  cupreous  soap  and  ferruginous  soap  that  is,  a  combin- 
ation of  the  oxides  of  copper  and  iron  with  the  marganc  acid  of  the  soda  soap.     1  toe 
copper  soap  is  green,  the  iron  soap  is  reddish  brown,  and  both  together  resemble  that 
green  rust  which  is  characteristic  of  the  antique  bronzes.     When  the  precipitate  is  com 
pletely  separated,  a  fresh  portion  of  the  vitriol  solution  is  to  be  poured  upon  it  in  a 
copper  pan,  and  is  made  to  boil,  in  order  to  wash  it     After  some  ^ime,  the  iqmd  part 
must  be  decanted,  and  replaced  by  warm  water  for  the  purpose  of  washing  the  metallie 
soaps.     They  are  finally  treated  with  cold  water,  pressed  in  a  linen  bag,  drained  and 
dried.     In  this  state  the  compound  is  ready  for  use  in  the  following  way :-- 

Three  pounds  of  pure  linseed  oil  are  to  be  boiled  with  12  ounces  of  fanely-powdered 
litharge,  then  strained  through  a  coarse  canvass  cloth,  and  allowed  to  stand  m» 
warm  place  till  the  soap  turns  clear.  Fifteen  ounces  of  this  ^f^P-^^^-^^^b'^jf^l^^^JS 
12  ounces  of  the  above  metallic  soaps,  and  6  ounces  of  fine  white  wax^  are  to  be  me  ted 
together  at  a  gentle  heat  in  a  porcelain  basm.  by  means  of  a  water  bath.  The  mixture 
must  be  kept  for  some  time  in  a  melted  state,  to  expel  any  moisture  which  it  may  contain. 
It  must  be  then  applied,  by  means  of  a  painter's  brush  to  the  surface  o^th^  gypsum  pre- 
viously heated  to  the  temperature  of  about  200°  F.  By  skilful  management  ot  the  heat 
the  colour  may  be  evenly  and  smoothly  laid  on  without  filling  up  the  minute  hneamente 
of  the  buttT  Vhen  after  remaining  (n  the  cool  air  for  a  few  days,  the  smell  of  the  pig- 
ment has  gone  off,  the  surface  is  to  be  rubbed  with  cotton  wool,  or  a  f/^^  l^l"«"/^g'  *°^ 
yariegated  with  k  few  streaks  of  metal  powder  or  shell  gold  Small  « V^t*  "^ay  be 
dipped  in  the  melted  mixture,  and  then  exposed  to  the  beat  of  a  fire  till  they  are 
thoroughly  penetrated  and  evenly  coated  with  it  ^     ^       • ,  +    k^  i™:fo+^;j  \.rr 

The  patina  antica  {^rugo  nobilis)  of  the  Italian  antiquaries  is  said  to  be  »m»tated  by 
plungi^  the  copper  medTls  in  a  boiling-hot  solution  of  2  parts  of  verdigris  and  1  of 
Ll  ammlniac,  so  much  diluted  as  to  be  neariy  tasteless  They  are  allowed  to  remain 
^  the  solutioi  till  they  take  an  agreeable  reddish  or  yellowish  brown  colour,  when  th* 
fluid  is  to  be  poured  off.  and  the  medals  washed  and  dried.  •  „  v^  K««f  ;„« 

Bronze  Powder  consists  of  a  metallic  alloy  reduced  to  thm  lamin«  by  beating 
between  skins  or  membranes  in  the  ordinary  way.  and  then  triturated  ^^tj)  fin«  P^^der 
along  with  oil,  to  prevent  oxidation  by  the  atmosphere  The  leaves  are  put  first  into 
an  iron  wire  ^ieve  of  ten  meshes  U>  the  inch;  olive  oil  is  then  allowed  to  flow  free^ 
from  a  stopcock  over  the  centre  of  the  sieve  on  to  the  leaf  metal  which  is  briskly  moved 
over  the  surface  of  the  sieve  with  a  wire  brush,  untd  the  whole  is  forced  through  into 
a  vessel  below.  This  mixture  of  metal  and  oil  is  then  introduced  through  a  funnel 
hopper  of  the  triturating  machine,  and  spreading  among  the  rods  is  caused  by  their 
rotation  to  approach  the  periphery  of  the  steel  bed  beneath,  and  escape  into  a  circular 
trough,  whence  they  are  conducted  by  a  spout  into  another  vessel  In  this  progress  the 
metal  is  acted  upon  by  polished  hemispherical  bottoni  ends  of  upright  rods,  as  they 
S^end  and  descend  the  corrugated  surface  of  the  steel  bed.  and  which  by  a  tearing  and 
burnishing  operation,  separate  t^e  coarse  pieces  of  leaf  into  a  multitude  of  polished 
Seles  By  being  passed  three  times  through  the  machine,  the  metal  is  reduced  to 
the  quality  of  a  coafse  bronze  powder ;  and  is  then  subjected  to  a  similar  machine  con- 
tahi?ng  sm^aller  rods,  tossed  up  and  down  by  the  revolution  of  the  corrugated  angular 
bed  of  which  they  rapidly  dance  till  the  requisite  fineness  be  produced.  The  content, 
of  the  vlsel  wMch  aVe  usually  10  pounds  of  metal  and  10  pounds  of  oil,  are  then  put 
Lato  a  strong  W  made  of  thfee  thicknesses  of  fustian,  with  their  respective  seams  at 
Afferent  pafts  of  the  circumference,  so  as  to  prevent  the  metallic  particles  from  passmg 


through.  This  bag  is  subjected  to  the  action  of  a  hydraulic  press,  of  about  300  tons 
upon  a  bag  of  one  foot  diameter,  neariy  all  the  oil  is  expelled.  The  empty  bag  is  filled 
with  boiling  water,  and  again  squeezed;  and  after  two  or  three  repetitions  of  this  washing 
all  the  oil  comes  out  in  the  form  of  an  emulsion.  The  bag  now  contains  only  a  denS 
lump  of  bright  metallic  particles  of  nearly  the  gravity  of  the  original  metal.  This  lump 
is  cut  with  a  knife  into  slices  about  half  an  inch  thick,  and  exposed  to  the  air  of  a  warm 
room,  where  the  moisture  evaporates,  and  the  slices  may  then  be  crumbled  into  powder. 
(Newton's  Journal,  xxiv.  321.)  * 

BRONZING  {of  Objects  in  Imitation  of  Metallic  Bronze).  Plaster  of  Paris,  paper 
wood,  and  pasteboard,  may  be  made  to  resemble  pretty  closely  the  appearance  of  articled 
of  real  bronze,  modern  or  antioue.  The  simplest  way  of  giving  a  brilliant  aspect  of 
this  kind  18  with  a  varnish  made  of  the  waste  gold  leaf  of  the  beater,  ground  L  on  a 
porphyry  slab  with  honey  or  gum-water.  A  coat  of  drying  linseed-oil  should  be  first 
applied,  and  then  the  metallic  powder  is  put  on  with  a  linCn  dossil.  Mosaic  gold 
ground  up  with  six  parts  of  bone-ashes  has  been  used  in  the  same  way.  When  it  is 
to  be  put  on  paper,  it  should  be  ground  up  alone  with  white  of  eggs  or  spirit  varnish, 
applied  with  a  brush,  and  burnished  when  dry.  When  a  plate  of  iron  is  plunged  into 
a  hot  solution  of  sulphate  of  copper,  it  throws  down  fine  scales  of  copper,  which  beinir 
repeatedly  washed  with  water,  and  ground  along  with  six  times  its  weight  of  bonS 
ashes,  forms  a  tolerable  bronzing.  ^ 

Powdered  and  sifted  tin  may  be  mixed  with  a  clear  solution  of  isinglass,  applied 
with  a  brush,  and  burnished  or  not,  according  as  a  bright  or  dead  surface  is  desired. 
Gypsum  casts  are  commonly  bronzed  by  rubbing  brilliant  black-lead,  graphite,  upon 
them  with  a  cloth  or  brush.  Real  bronze  long  exposed  to  the  air  gets  covered  with  a 
thin  lilm  of  carbonate  of  copper,  called  by  virtuosi  antique  cerugo  {patine  antique,  Fr.). 
liiis  may  be  imitated  in  a  certain  degree  by  several  applications  skilfully  made.  The 
new  bronze  bein^  turned  or  filed  into  a  bright  surface,  and  rubbed  over  with  dilute 
aquafortis  by  a  linen  rag  or  brush,  will  become  at  first  greyish,  and  afterwards  take  a 
greenish  blue  tint;  or  we  may  pass  repeatedly  over  the  surface  a  liquor  composed  of 
1  part  of  sal  ammoniac,  3  parts  of  carbonate  of  potash,  and  6  of  sea-salt  dissolved  in 
12  parts  of  boiling  water,  to  which  8  parts  of  nitrate  of  copper  are  to  be  added  •  the 
trnt  thereby  produced  is  at  first  unequal  and  crude,  but  it  becomes  more  uniform  and 
softer  by  time.  A  fine  green-blue  bronze  may  be  obtained  with  very  strong  water  of 
ammonia  alone,  rubbing  it  at  intervals  several  times  upon  the  metal. 

The  base  of  most  of  the  secret  compositions  for  giving  the  antique  appearance  is 
Yinegar  with  sal  ammoniac.  Skilful  workmen  use  a  solution  of  2  ounces  of  that  salt  in 
an  li^nglish  quart  of  French  vinegar.  Another  compound  which  gives  good  results  is 
made  with  an  ounce  of  sal  ammoniac,  and  a  q^uarter  of  an  ounce  of  salt  of  sorrel  (binox- 
alate  of  potash)  dissolved  in  vinegar.  One  eminent  Parisian  sculptor  makes  use  of  a  mix- 
ture of  half  an  ounce  of  sal  ammoniac,  half  an  ounce  of  common  salt,  an  ounce  of  spirita 
of  hartshorn,  and  an  English  quart  of  vinegar.  A  good  result  will  also  be  obtained  by 
adding  half  an  ounce  of  sal  ammoniac,  instead  of  the  spirits  of  hartshorn.  The  piece 
of  metal  being  well  cleaned,  is  to  be  rubbed  with  one  of  these  solutions,  and  then  dried 
by  friction  with  a  fresh  bmsh.  If  the  hue  be  found  too  pale  at  the  end  of  two  or 
three  dajs.  the  operation  may  be  repeated.  It  is  found  to  be  more  advantageous  to 
operate  in  the  sunshine  than  in  the  shade. 

BROWN  DYR  Upon  this  subject  some  general  views  are  given  in  the  article 
Dteing.  explanatory  of  the  nature  of  this  colour,  to  which  I  may  in  the  first  place  refer 
This  dye  presents  a  vast  variety  of  tints,  from  yellow  and  red  "to  black  brown  and  is 
produced  either  by  mixtures  of  red,  yellow,  and  blue  with  each  other,  or  of  yellow  or 
red  with  black,  or  by  substantive  colours,  such  as  catechu  or  oxide  of  manganese, 
alone.  We  shall  here  notice  only  the  principal  shades;  leaving  their  modifications  to 
the  caprice  or  skill  of  the  dyer. 

1.  Brown  from  mix-ture  of  other  coloui-s. 

Wool  and  woollen  cloths  must  be  boiled  with  one  eighth  their  weight  of  alum  and 
sulpho-tartrate  of  iron  (see  this  article) ;  afterwards  washed,  and  winced  through  the 
madder  batli,  which  dyes  the  portion  of  the  stuff  imbued  with  the  alum  red,  and  that 
with  the  salt  of  iron  black ;  the  tint  depending  upon  the  proportion  of  each,  and  the 
duration  of  the  madder  bath. 

A  similar  brown  is  produced  by  boiling  every  pound  of  the  stuff  with  two  ounces  of 
alum,  and  one  ounce  of  common  salt,  and  then  dyeing  it  in  a  bath  of  logwood  contain- 
ing either  sulphotartrate,  acetate,  or  sulphate  of  iron.  Or  the  stuff  may  be  boiled  with 
alum  and  tartar,  dyed  up  in  a  madder  bath,  and  then  run  throush  a  black  bath  of  iron 
mordant  and  galls  or  sumach.  Here  the  black  tint  is  added  to  the  red  till  the  proper  hue 
be  hit.  The  brown  may  be  produced  also  by  adding  some  iron  liquor  to  the  madder  bath. 
^cr  the  stufi"  has  been  dyed  up  in  it  with  alum  and  tartar.  A  better  brown  of  this 
land  IS  obtained  by  boiling  every  pound  of  wool  with  2  ounces  of  alum,  dyeing  it  up  in 
eoebmeal,  then  changing  the  crimson  thus  given  into  brown,  by  turning  the  stuff  through 


286 


BROWN  DYE. 


)« 


I 


Ir 


1^: 


the  bath  after  acetate  of  iron  has  been  added  to  it.    Instead  of  the  cochineal,  archil,  or 
cutbear,  with  a  little  gaUs  or  sumach,  may  be  used.  ,;     .   ,.  ,       , 

Wool  or  silk  may  also  receive  a  light  blue  ground  from  the  mdigo  vat,  then  be  mor- 
ianted  with  alum,  washed,  and  turned  through  a  madder  bath  till  the  wished-for  browii 
be  brought  out.  For  the  deeper  shades,  galls  or  sumach  may  be  added  to  the  paler  Brazd- 
wood  with  more  or  less  iron  mordant.  Instead  of  the  indigo  vat,  Saxon  blue  may  be 
employed  to  ground  the  stuff  before  dyeing  it  with  madder,  or  5  pounds  of  madder,  with 
1  pound  of  alum,  a  solution  of  one  tenth  of  a  pound  of  indigo  in  sulphuric  acid,  may  be 
used  with  the  proper  quantity  of  water  for  20  pounds  of  wool;  for  dark  shades,  some  iron 
mordant  may  be  added.  Or  we  may  combine  a  bath  of  cochineal  or  cutbear,  fustic, 
and  galls,  and  add  to  it  sulphate  of  iron  and  sulphate  of  indigo,  blunted  with  a  little 

If  we  boil  woollen  cloth  with  alum  and  tartar,  then  pass  it  through  a  madder  bath,  and 
afterward  through  one  of  weld  or  fustic,  containing  more  or  less  iron  mordant,  we  obtain 
shades  variable,  according  to  the  proportions  of  the  materials,  from  mordore  and  cinnamon 

to  chestnut  brown.  .     ,  -         ,         .        r    v      j 

After  the  same  manner,  bronze  colors  may  be  obtained  from  the  union  of  olive  dyes 
with  red.  For  25  pounds  of  cloth,  we  take  4  pounds  of  fustic  chips,  boil  them  for  2  hours, 
turn  the  cloth  in  this  bath  for  an  hour,  and  drain  it ;  then  add  to  the  bath  from  4  to  6 
ounces  of  sulphate  of  iron,  and  1  pound  of  ordinary  madder,  or  2  pounds  of  sandal-wood ; 
put  the  cloth  again  in  this  compound  bath,  and  turn  it  through,  till  the  desired  shade  be 
obtained.    By  changing  the  proportions,  and  adding  an  iron  mordant,  other  tinU  may  be 

This  mode  of  dyeing  is  suitable  for  silk,  but  with  three  difieient  baths ;  one  of  logwood, 
one  of  BrazU-wood,  and  one  of  fustic.  The  silk,  after  being  boiled  \i'iih  soap,  is  to  be 
alumed,  and  then  dyed  up  in  a  bath  compounded  of  these  three  decoctions,  mixed  in  the 
requisite  proportions.  By  the  addition  of  walnut  peels,  sulphate  of  copper,  and  a  little 
sulphate  of  iron,  or  by  passing  the  silk  through  a  bath  of  annotto,  a  variety  of  brown 

shades  may  be  had.  .      v  .v    r  i 

Or  the  silk  may  receive  an  annotto  ground,  and  then  be  passed  through  a  bath  of  log- 
wood or  Brazil-wood.  For  10  pounds  of  silk,  6  ounces  of  annotto  are  to  be  taken,  and 
dissolved  with  18  ounces  of  potashes  in  boiling  water.  The  silk  must  be  winced  through 
this  solution  for  2  hours,  then  wrung  out,  dried,  next  alumed,  passed  through  a  bath  of 
BrazQ-wood,  and  finally  through  a  bath  of  logwood,  containing  some  sulphate  of  iron. 
It  Ls  to  be  wrung  out  and  dried.  .  ..      ^.  ..v 

Brown  of  different  shades  is  imparted  to  cotton  and  linen,  by  impregnating  them  with 
a  mixed  mordant  of  acetates  of  alumina  and  iron,  and  then  dyeing  them  up,  either  with 
madder  alone,  or  with  madder  and  fustic.  When  the  aluminous  mordant  predominates, 
the  madder  gives  an  amaranth  tint.  For  horse-chestnut  brown,  the  cotton  must  be  galled, 
plunged  into  a  black  bath,  then  into  a  bath  of  sulphate  of  copper,  next  dyed  up  in  a  de- 
coction of  fustic,  wrung  out,  passed  through  a  strong  madder  bath,  then  through  the  sul- 
phate of  copper  solution,  and  finished  with  a  soap  boil.  Different  shades  of  cinnamon 
are  obtained,  when  cottons  first  dyed  up  with  madder  get  an  oUve  cast  with  iron  liquorin 

a  fustic  bath.  ,  v     j     •      *v       n    •  •        v  «v 

These  cinnamon  and  mordore  shades  are  also  produced  by  dyeing  them  first  ma  balli 
of  weld  and  verdigris,  passing  them  through  a  solution  of  sulphate  of  iron,  wringing  and 
drying  them;  next  putting  them  through  a  bath  containing  1  pound  of  galls  for  10  pounds 
of  stuff,  again  drying,  next  aluming,  and  maddering.     They  must  be  brightened  by  a  bod 

in  soap  water.  ,        .  •  .   ,  ■, 

A  suijerior  brown  is  produced  by  like  means  upon  cotton  goods,  which  have  undergone 
the  oiling  process  of  the  Turkey  red  dye.  Such  stuffs  must  be  galled,  mordanted  with 
alum  (see  Madder),  sulphate  of  iron,  and  acetate  of  lead  (equal  to  f  of  the  alum);  after 
washing  and  drying,  dyed  in  a  madder  bath,  and  cleared  with  a  soap  bod.  The  tint  of 
brown  varies  with  the  proportion  of  alum  and  sulphate  of  iron. 

We  perceive  from  these  examples,  in  how  many  ways  the  browning  of  dyes  may  be 
modified,  upon  what  principles  they  are  founded,  and  how  we  have  it  in  our  power  to  turn 
the  shade  more  or  less  toward  red,  black,  yellow,  blue,  &,c. 

Brown  may  be  produced  by  direct  dyes.  The  decoction  of  oak  bark  dyes  wool  a  fast 
brown  of  different  shades,  according  to  the  concentration  of  the  bath.  The  color  is  more 
lively  with  the  addition  of  alum.  , 

The  decoction  of  bastard  marjoram  {Onganum  vulgare)  dyes  cotton  and  Imen  a  red- 
dish brown,  with  acetate  of  alumina.     Wool  takes  from  it  a  dark  brown. 

The  bark  of  the  mangrove  tree  {Eizophara  mangle)  affords  to  wool  boded  with  alum 
and  tartar  a  fine  red  brown  colour,  which,  with  the  addition  of  sulphate  of  iron,  passes 

into  a  fast  chocolate.  .  -,  .^_     ^r  •         itr- 

The  Bahlah,  the  pods  of  the  East  Indian  Mimom  cirurana,  and  the  African  Mimota 

niloticcL  gives 'cotton  a  brown  with  acetate  or  sulphate  of  copper. 

The  r<S)t  of  the  white  sea  rose  {Nytnphcea  alba)  gives  to  cotton  and  wool  beautdul 


BUTTER.  287 

shades  of  brown.  A  mordant  of  sulphate  of  iron  and  zinc  is  first  given,  and  then  the 
wool  18  turned  through  the  decoction  of  the  root,  tiU  the  wished-for  shade  is  obtained, 
ine  cotton  must  be  mordanted  with  a  mixture  of  the  acetates  of  iron  and  zinc. 

walnut  peels  {Juglans  regia),  when  ripe,  contain  a  dark  brown  dye  stuff,  which  com- 
municates a  permanent  color  to  wool.     The  older  the  infusion  or  decoction  of  the  peels, 

^  A  rJ^^  u**^^.  *^  ™*^^-  "^^^  ^*"ff  ^s  dyed  in  the  lukewarm  bath,  and  needs  no 
mordant,  though  it  becomes  brighter  with  alum.     Or  this  dye  may  be  combined  with  the 

wn  'I'l'  ^r^h^""  ^'7*^  ''''^'^^'^^  of  shade.    For  dyeing  silk,  this  bath  should  be 

hardly  lukewarm,  for  fear  of  causing  inequality  of  color    ^      =*        '  ^ 

fn  .K*"  P^!""^^*'^  horse-chestnuts  may  be  used  for  the  same  purpose.     With  muriate  of 
tm  they  give  a  bronze  color,  and  with  acetate  of  lead  a  reddish  brown. 
.nInHnn  r  I'T  7"°?  *  permanent  brown  dye,  as  also  a  bronze,  and  mordore,  when  its 
solution  in  hot  water  is  combined  with  acetate  or  sulphate  of  copper,  or  when  the  stuff 

^i;rrJ^°'''^'"'lr'^  ?'  "^.r^I  ^^  ^«PP^^  ^'^  alumina'mixeS,  some^iTes  ^^1 
Fprrn.v      J     r'  ""'^'  ^"^^'  ^''\P^  "P'  ^^^  ^^^^^  ^'"^  ^^  a  boiliug  heat. 
Ferrocyanate  of  copper  gives  a  yellow  brown  or  a  bronze  to  cotton  and  silk. 

toTot^  mr^ro^'v"^-^  carme/i/c  by  the  French  is  produced  by  one  pound  of  catechu 
L^vLL??  I-  \f'^^^»^.'  ^^^^  five  ounces  of  muriate  of  ammonia.  The  bronze 
(soluaire)  is  given  by  passing  the  stuff  through  a  solution  of  muriate  or  sulphate  of 
manganese,  with  a  little  tartaric  acid,  drying,  passing  through  a  potash  ley  at  4°  Bauml 
brightening  and  fixing  with  solution  of  chloride  of  lime        ^       ^  ^    '  ^  x>aume, 

Octo^er^^ffn  fifT'-'  ^'•'  ^":*f«»'  Germ.)  Mr. *T.  Mason  obtained  a  patent  in 
firmer  mnfV  2  '      /"^P/ovement  m  the  manufacture  of  this  article.    It  consists  in  a 

the  br.r  Th;f -'"I  '^'i^^°''  ^'  '™^"  '^""^'"^  ""^  ^"^'^  i"t«  t^e  stock  or  the  handle  of 
«f  ro«-  •     Tk        /*'''r  ^J  ^^^'-^i^? /"-ooves  m  the  stocks  of  the  brushes,  for  the  purpose 

?i^hn?SrV^>f  ^''^'  °^  '^'  ^"'''  ?^  ^*'^'  ^"^^^«d  «^  t^^  ^«J^«  drilled  into  the  wood^w 
nr  l7ii  ,1  K  "".r""*?  constructions.  These  grooves  are  to  be  formed  like  a  dovetail, 
or  wider  at  the  bottom  than  the  top;  and  when  the  ends  of  the  knots  of  hair  have  been 

tLd^^h  ^A  ^  ^^^  ^^''  "^'^  ^^  P'^'"^'^  outwards  into  the  recess  or  wider  part  of 

tlrl-Hl  £-11  ^^  ^^y^t^^'^d-'  ^"d  thf  <^ement  and  hairs  being  pressed  into  the  teeth  ot 
threads,  will  cause  them  to  adhere  firmly  to  the  stock  or  handle  of  the  brush. 

.n^  /T"^  '"^^  ^^  P'^^^'^  °"  t^^  **"t^''^de  «f  the  stock  of  the  brush,  if  necessary 

and  secured  by  pms  or  rivets,  or  in  any  other  convenient  manner,  which  femdemT; 


209 


ee  also  form  one  side  of  the  outer  groove.  Fig.  209  is 
a  plan  view  of  the  stock  of  a  round  brush  ;  Jig.  210 
IS  a  section  of  the  same ;  a  o  are  the  dovetailed  grooves, 
which  are  turned  out  of  the  wood ;  b  is  the  metal  fer- 
rule ;  c  c  are  knots  or  small  bundles  of  hair,  to  form 
the  brush.  After  a  number  of  the  knots  of  hair  are 
prepared,  the  ends  are  to  be  dipped  into  proper  cement, 
and  then  placed  into  the  grooves,  when  their  ends  are 
to  be  squeezed  by  a  pair  of  pliers,  or  other  means,  which 
will  compress  them  into  the  oval  shape,  as  shown  in 
Jig.  211  and  cause  the  ends  of  the  hairs  to  extend  ouU 
ward  under  the  dovetailed  part  of  the  recess. 

The  knots  of  hair  are  to  be  successively  placed  in  the 
grooves,  and  forced  up  by  a  tool  against  the  last  knot 
put  in>  and  so  on,  until  the  grooves  are  filled  •  /?<>•  211  i« 
a  section  taken  through  a  brush  with  teeth  or  threads  of  a  screw  formed  ulVt^eL 
of  the  groove;  into  these  teeth  or  threads  the  cement  and  hairs  will  be  forced  by  the 

Suttfr'  ^^,  p^^'^  "^T'  '1%  ^"^.^"  ^'^^  ^'""^y  i"  th«  stock  of  the  brush        ^ 
BUTTER.    {Beurre,  Fr. ;   Butter,  Germ.)     Milk  contains  a  fatty  matter  of  more 

Sorit'Tht'"Tt"*^^^'V',7°'r,*i  ^''^''^^^  '°  '^^  "^ture  of  the  animals  which 
Sr  LnJ    1  substance  is  butter,  held  suspended  in  the  milk  by  means  of  the  caseous 

^nhfna  r  'T  ^^^  ^^^^^^  \  »«  mUmately  blended.  Milk  is  a  true  emulsion 
Soi  ?l  tlT^^'  ""T  ""i  >''r  three  ingredients,  owing  its  opacity  and  white 
5?i?L.  ^-  '^'^"'''*''  ^u'°''»^  '^  ""^  ^^*t  butyraceous  oil.  When  any  circumstance 
dissolves  this  union,  each  component  becomes  insulated,  and  manifests  itrneculirr 
properties.     Mill^  even  left  to  itself,  at  a  temperature  of  f^om  50°  to  60°  F    se^^  es 

na?urrflTf  ^  '""'f^  ""'T^  ^^^^  ^  '^^^^^  «^  ^  ^^"^^'  ™ore  consistLtrbutSer 
nature  floats  on  its  surface,  while  the  subjacent  liquid  forms  a  white  maema  which 
retains  among  ite  curdy  flocks  all  the  whey  of  the*  milk.  The  upper MaToI-  rrelm 
r/wh:;  bl'w.^  "'^'^  ^^  '^^  ^"^^^ '  ^^^  ^  P-^-  ----  entS^led^i^^the  cm^ 


'»-! 


288 


BUTTON  MANUFACTURE. 


It  belongs  to  a  work  on  husbandry  or  rural  economy  to  treat  fully  of  the  operations 
of  the  dah-?-  one  of  the  principal  of  which  is  the  extraction  of  butter  from  milk. 
The  Tartars  and  French  have  been  long  in  the  habit  of  preserving  butter,  by  melting 
xue  iditdiTj  ttii^  wherebvare  coagulated  the  albuminous  and  curdy  matters 

It  With  a  °^«<if  ^2?^.^^^^^^  J^^^^^  This  fusion  should  be  made  by  a  heat  of 

remammg  in  t  wh  ch  are^very  pu^^^^^^  ^.^^  ^^  ^^^^^  ^^^  ^^^^  ^^^ 

puHfi  Ition  o  ttetutler.  !?  in  this  settled  liquefied  state  it  be  carefully  decanted, 
Eed  through  a  tammy  cloth,  and  slightly  salted,  it  may  be  kept  for  a  long  time 
Sy  fresh,  without  becoming  in  any  degree  rancid,  more  especially  if  it  be  put  up  m 

^"Butrif  tt'^aurmatter  of  milk,  usually  of  that  of  the  eow  Milk  is.com- 
pofed  of  butter,  caserne,  sugar  of  milk,  several  salts,  and  water.  The  butter  exists  m 
the  form  of  very  small  globules  of  nearly  uniform  size,  quite  transparent,  and  strongly 
refractive  of  light  Milk  left  in  repose  throws  up  the  lighter  particles  of  butter  to  the 
surface  as  creJm.  It  was  imagined  that  the  butter  was  separated  in  th^  process  of 
churning,  in  consequence  of  the  milk  becommg  sour;  but  this  is  not  the  case,  for  niilk 
rendered  alkaline  %  bicarbonate  of  potash  affords  its  butter  fully  ^o^^^.^^^^'  {  *»^^y 
acidulous  milk.  The  best  temperature  for  churning  milk  or  cream  is  53  b. ,  that  ol 
60°  is  too  hicrh ;  and  under  50°  it  is  too  low.  By  the  churning  action  the  heat  rises  from 
3  to  4  decrees  F.  All  the  particles  of  butter  are  never  separated  by  churning ;  many 
remain  diffused  through  the  butter-milk,  and  are  easily  discoverable  bv  the  microscope. 
S  are  more  numerous  in  proportion  to  the  bulk  of  the  liquid ;  ancJ  hence  it  is  more 
economical  to  churn  cream  th^an^he  whole  milk  which  affords  it  It  is  eompf  ^d  ^^at 
a  cow  which  gives  1800  quarts  (old  English)  of  milk  per  annum  eats  in  that  time  8000 
fbl^f  hay,  and  produces  UO  lbs.  of  butter.*  Analysis  shows  that  tnis  weight 
of  hay  contains  168  pounds  of  fat.  The  finest  fl a voure<r  butter  is  obtained  from  milk 
churned  not  long  atUr  it  is  drawn;  but  the  largest  proportion  is  derived  from  the 
cream  thrown  up  by  milk  after  standing  24  hours,  m  a  temperature  of  about  50  F. 
The  butter-milk,  which  contains  the  very  fermentable  substance  caseine,  should  be  well 
separated  from  the  butter  by  washing  with  cold  water,  and  by  beating  with  the  hands, 
or  preferably,  without  water,  for  the  sake  of  fine  flavour,  by  the  action  of  a  pres^ 

The  Fren/h  purify  their  butter  by  melting  it  in  pots,  plunged  into  water  heated  to 
200°  or  212° ;  and  sometimes  they  mix  a  pure  brine  with  the  nleltlngbuttel^  whereby 
they  favour  the  subsidence  of  the  coagulated  caserne  and  other  impunt.es.  The  super- 
natint  clear  butter  should  be  drawn  or  poured  off,  and  rapidly  cooled,  to  pi-event  the 
crystaUization  of  its  stearine  and  separation  of  its  oleine,  which  injure  its  flavour  and 

appearance.  ^  ,  _. 

Butter  of  Cacao.    See  Cacao,  Chocolate,  and  Oii^.  ^   u        i.       

BUTTON  MANUFACTURE.  This  art  is  divided  into  several  branches,  con- 
stituting so  many  distinct  trades.  Horn,  leather,  bone,  and  wood,  are  the  substances 
frequently  employed  for  buttons,  which  are  either  plain  or  covered  with  silk,  mohair, 
thread  or  other  ornamental  materials.  The  most  durable  and  ornamental  buttons  are 
made  of  various  metals,  polished,  or  covered  with  an  exceedingly  thm  wash,  as  it  is 
termed,  some  more  valuable  metal,  chiefly  tin,  silver,  and  gold.  ,  .^ 

Those  buttons  intended  to  be  covered  with  silk,  Ac,  are  termed  in  general  moulds 
They  are  small  circles,  perforated  in  the  centre,  and  made  from  those  refuse  chips  of 
bone  which  are  too  small  for  other  purposes.  These  chips,  which  for  the  large  and 
coarser  buttons,  are  pieces  of  hard  wood,  are  sawn  into  thin  flakes,  of  an  equal  thickness ; 
from  which,  by  a  machine,  the  button  moulds  are  cut  out  at  two  operations. 

The  shavings,  sawdust  and  more  minute  fragments  are  used  by  manufacturers  of 
cutlery  and  i?on  toys,  in  the  operations  of  case-hardening;  so  that  not  the  smallest 

waste  takes  place.  ^  ,  ^  j     i.-i,  i.  it 

Metal  buttons  are  formed  of  an  inferior  kind  of  brass,  pewter,  and  other  me. alhc 
compositions:  the  shanks  are  made  of  brass  or  iron-wire,  the  formation  of  which  is  a 
distinct  trade.  The  buttons  are  made  by  castmg  them  round  the  shank.  J?or  this 
purpose  the  workman  has  a  pattern  of  metal,  consisting  of  a  great  number  of  circular 
buttons  connected  together  in  one  plane  by  very  small  bars  from  one  to  the  next ;  and 
the  pattern  contains  from  four  to  twelve  dozen  of  buttons  of  the  same  size.  An 
impression  from  this  pattern  is  taken  in  sand  in  the  usual  manner;  and  shanks  are 
Dressed  into  the  sand  in  the  centre  of  each  impression,  the  part  which  is  to  enter  the 
metal  bein^r  left  projecting  above  the  surface  of  the  sand.  The  buttons  are  now  cast 
from  a  mixture  of  brass  and  tin ;  sometimes  a  small  proportion  of  zmc  is  added,  which 
is  found  useful  in  causing  the  metal  to  flow  freely  into  the  mould,  and  makes  a  sharp 
casting  When  the  buttons  are  cast,  they  are  cleaned  from  the  sand  by  brushing ; 
thev  are  then  broken  asunder,  and  carried  to  a  second  workman  at  the  lathe,  who 
inserts  the  shank  of  a  button  into  a  chuck  of  a  proper  figure,  in  which  it  is  retained  by 

•  Two  pounds  and  a  quarter  of  hay  correspond  to  one  quart  of  good  milk ;  and  a  cow  wWch  eaU 
16.500  Ibsfof  hav  will  produce  300  lbs.  of  butter  oer  annum. 


BUTTON  MAFCJFACTURE. 


289 


circumference  is  now  Vv  "fiiT  "T^  pressea  against  the   button  with  a  sprine     The 
button  is  Sntly  r^Jeaid  b^^^  'l^"?^  *«  *  ^'^^  circ?e    fnd^e 

by  another.     A  t^ird"„mVn^^^^  lft%  YA  '^'  ^^°*^^'  ^°^  is  replaced 

lathe,  and  makes  the  TrojecSL  pTrt  Znd^  f^^^^^^  the  button  smooth,  in  a  chuck 
the  face  of  the  button  srnioth  h/.tlo  'I-  ^  f  ^^'^  ^"^^ '  *°<^  »  fourth  rendere 
squaie  bar  of  steef LiC ite  LL^^^'^"^  ''  "^  *  ^^"^^  ^^^  ^PP^J^^S  the  ed^e  of  a 

WnL' d":XLu-T^^^^^^  T.^*--  ^  «-"  ^"oy  of  zincX 

press,  which  cute  them  out  at  one  stroke  rif^'"^  7^'  '^"°^P  ''  urged  by  a  fly- 
annealed  in  a  furnace  to  soften  them  and  th.Zl  ''''"^^'  ^?'^''  "*"^^  ^^^^^s.  are 
by  a  monkey,  which  is  a  machine  Try  sfmifc^^^^^  ^%l^  ''''''^  «"  ^^^^ack 

the  face  very  slightly  convex,  tliat  tZ  hnll^l  ^  ^  ^"^V^^'  ^'^  st;amp  also  renders 
process     Tlie  sSani^  a^next    o^  '^ ''''  S^^ 

piece  of  hematites  or  blood-stone,  fixed  Into  a  haldle  .nT^'^  i\  Pt^^^rmed^  byl 
revolves  by  the  motion  of  the  lathe  '    ^  apphed  to  the  button  &a  it 

A  great  number  of  the  buttons,  thus  prcDared  fnv  »ilA' 
fu'^r'^.f'  the  proper  quantity  of  goirtfcoverthe^  if  "^'  ^^^  ^""^  ^^^«  «^  ^^^^^^ 
the  following  manne?:-.The  gold  I  nut  Infn  aT'     *°l^^,*°iated  with  mercury  in 
of  mercury  added  to  it;  the  ladle  is  Ldov?/^^^^^  ^  ^^^^  quantity 

perfectly  united.    This  amalgarbe4  it  fntn  ^^^^  ^^t  ^^^^  ^^^  "^^^^^J  ^^e 

aquafortis,  diluted  with  watef,Ts  wUl  w^et  them  aH  o^v"?  "^''^  '^'  ^"*^«"^  ^«  ^^<^^ 
stirred  up  with  a  brush,  till  th^  aciT  bWts  affin^tv  LT;^  '  ''  ^^'^'^'^  "'  ^"^  ^^^7  ^^ 
to  every  part  of  its  surface,  coverin/ft  wifh  fhX  ^^  ''''^^^I'  ^*^"^«  **»«  amalgam 
perfected,  the  acid  is  washed  aTay  with  dean  wateTThf '  '^  '^T  ^^*^^°  *^  ^^ 
IR  called  quieking.  ^  ^^°  ^^^^^'     This  process  by  the  workman 

to  t^^  oterKr^sttt^^^^^^^^^^^  ^ru^  ^^'  was  e-edingly  pernicious 

violent  poison.     In  order  to  obWate  tC  the  fnl  W      ^i        ?  "^  "^^^  ^^^^^  *«  ^«  « 
ployed  with  success.    The  vapour  i  it  rkes  fro^  7  ^^  ^l^u  ^^  ^PP^^^t^s  has  been  em- 
fire,  is  conducted  into  an  oblo^ig'^^n  flue  or  '^^^^^^^^  ^^^'^^  ^  a  charcoal 
Its  end  a  small  vertical  tube  dipping  into  a  w« +2'  ?«f  %«i«Pe<i  downwards,  having  at 
and  a  large  vertical  pipe  for  p  Z2i  g  the  draught  ofT   ""  T^-^T^  the  mercury, 
Plated  buttons  are  stamped^by  thrfl^v  prel^^^^^^^^^             ^'''f ''.'*'  "^  ^^^  combustioi! 
with  silver  at  the  flatting  mill     The  conK^r  !iil  '  "^^^^PP^^^-P^ate,  covered  on  one  side 
the  die  or  hole  through  wSthly  areEpcA   s  l^fl"^  T^"^/'  i'^  «^*°^P^°^'  ^^^ 
make  the  sUver  turn  over  the  edgTof  the  button  Ve^^\«hamfered  at  ite  edge,  to 
manner  as  the  gilt  buttons.     The  shanks  are  solder.d  n       -^  ^ -f  '^^^P^^  ^"  *^»^  «»"»« 
one  bv  one  in  the  flame  of  a  Iain's  a  blow  nfn!    ^  Tu^  ^^l^''  "*^^^*^'''  "°^  ^^^ted 
now  filed  smooth  in  the  lathe  ca^'e  WW  ^XTP'P,\''^Sed  by  bellows.     The  edges  are 

is  turned  over  the  edge!  TheVle  next^d  poed  TJVTT  "^^  "^  '^'  silver  which 
m  cream  of  tartar  and  silver,  iwhS  uF/J  after  wh^'f^T  '^'  ^^^^''  ^"^  ^^'^^^ 
backs  being  first  brushed  clein  by  a  brnsh  Idd  al^^^^^^  burnished,  the 

BuVt/'r"t'^^''"T^^"^^«^^^--^^  they  revolve  in  the 

lo^nrn^:^:fl^^^  "^^'^  'y  '^^^  ^--  ^--  -  -n  w^rtbent  and  cut  by  the  foL 

b/strgltfeVet^^^^^^  turned  round 

close  round  it  till  it  is  covered.  The  coU  of  W.  fK  ^  "^'^^  ^^  *^"^  ^«»"«  ^aPPed 
wh-e  fork  or  staple  with  paraL  legs  put  intir/t^^^^^^  ^  '"PP^^  «^' «°S  a 

a  punch  the  coil  of  wire  is  struck  down  Ween  the  f w.  .  '"^  ""^T  V  ""'"'  ^""^  ^Y 
form  a  figure  8,  a  little  open  in  the  mMdlf  The  pSnch  Lr^"^!,^^  ^\''^V'^  ^  *«  '^ 
middle  of  the  8,  and  the  coil  being  cut  ODcn  bv^«  ^  •      /?  ^^^^  ""^"^^^  "^^"^^^  the 

sti^:ii™rbVtL^^^^^^^ 

proved  shanks,  as  raised  or  formXS  of  the  d^  f  '  ^P^Tl'^  «^  ^"«  «^  ^is  im- 
back  of  the  button ;  Jig.  21-3  an  edl  viW  Lb'  «^,,°^^^1  ^liich  is  to  constitute  the 
214.  is  another  edge  W.^ookfufaK^^^  "'^  «^^^°^  «r  l<^op;/a. 

section  taken  through  the^Ck  f  nd  dte  irtht  t^^  r  ^'  ^V^.  ^^d^^ys;  /^.  215.'ira 
212. ;  and  Jiff.  216.  another  sSontakr  in^lt^?• '^'^^^^  ^^t^  4«"ed  line  a  b,  in  Jiff. 
212.    All  these  figures  of  Ls  improved  «^^^^^  ^'^'iV^^  1^^^  ?^"^^  ^^^«  «  «•  ^  fit 

together  with  the  tools  used  t^^C  the  «^m^  ^'  !J'"  ^  *^T  ^^^^i^^^er  described, 
^owthe  partsmore distinctly.  ^TwlSr-rth^^^^^^^ 


f 


200 


BUTTON  MANUFACTURE. 


by  partially  cutting  and  raising,  or  forcing  up  a  portion  of  the  metal  disc  or  back  b,  and 
are  compressed  or  iormed  by  the  action  of  the  tools,  or  punches  and  dies,  so  as  to  have 


^]214 


A213      213 


221     220  219    I 


226 


236 


H 


i 


@235    ^— \233 


a  rounded  figure  on  the  inside  of  the  top  part  of  the  shank,  as  at  c,  the  edges  of  the 
metal  being  turned  so  as  to  prevent  them  cutting  the  threads  by  which  the  button  is 
fastened  to  the  cloth  or  garment  It  will  be  observed  that,  there^emg  but  one  passage 
or  way  through  which  the  thread  can  be  passed  to  sew  on  the  button  and  that  opening 
being  rounded  on  all  edges,  will  cause  the  threads  to  keep  m  the  centre  of  the  shanks, 
the  form  of  the  shank  allowing  a  much  neater  attachinent  to  the  garment,  and  keeping 
the  threads  from  the  edges  of  the  metal.  The  ends  of  the  shank  or  portions  e  e,  which 
rise  up  from  the  disc  or  back  h,  are  made  nearly  circular,  m  order  to  avoid  presenting 
anv  edees  of  the  metal  to  the  sides  of  the  button-hole ;  and  when  the  shank  is  sewed  on 
the  cloth,  it  forms,  in  conjunction  with  the  threads,  a  round  attachment,  thereby  prevent- 
ing the  shank  from  cutting  or  wearing  the  button-hole :  the  threads,  when  the  shank  is 
properly  sewed  to  the  garment,  nearly  filling  up  the  opemng  through  the  shank  and  com- 
pleting that  portion  of  the  circle  which  has  been  taken  out  of  the  shank  by  the  dies  m 
forming  the  crescented  parts  of  the  loop.  It  will  be  therefore  understood  that  the  inten- 
tion is,  that  the  inside  edges  of  the  shank  should  be  turned  f  much  as  possible  away  from 
the  threads  by  which  the  button  is  sewed  on  the  cloth,  and  that  the  outside  of  the  shank 
should  be  fonned  so  as  to  present  rounded  surfaces  to  the  button-hole,  and  that  the 
thread  should  fill  up  the  opening  through  the  shank,  so  as  to  produce  a  round  attachment 
to  the  garment  It  should  here  be  observed,  that  the  backs  of  the  buttons  shown  m  these 
figures  are  of  the  shape  generally  used  for  buttons  covered  with  Florentine  or  other  fabric, 
or  faced  with  plates  of  thin  metal,  and  are  intended  to  have  the  edges  of  a  disc,  or  what  is 
termed  a  shell,  forming  the  face,  to  be  closed  in  upon  the  inclined  or  bevelled  ed^es  of 
the  backs.  Having  now  described  the  peculiar  form  of  the  improved  shanks  which  he 
prefers,  for  buttons  to  be  covered  with  Florentine  or  other  fabric,  or  shells  of  thin  metaj 
plate  he  proceeds  to  describe  some  of  the  diflferent  variations  from  the  same. 

Fiq  217  is  a  representation  of  a  shank,  the  cut  through  the  disc  or  back  being  effected 
bv  a  parallel  rib  on  the  die,  and  corresponding  groove  in  the  shaping  punch,  instead  of  the 
semi-circular  or  crescented  cut  shown  in  fig.  212;  fig.  218.  is  a  view  of  another  shank,  the 
separation  of  the  sides  of  the  loop  being  performed  by  straight  edges  m  both  punch  and 
d'e  He  prefers  finishing  this  shaped  shank  (that  is,  giving  it  the  rounded  form,  to  pre- 
yeiit  its  cutting  the  threads),  by  detached  punches,  and  dies,  or  pincers,  as  will  be  herein- 
after  described  Fig.  21 9.  is  a  representation  of  one  of  the  improved  shanks,  which  has 
merely  portions,  //,  of  the  back  of  the  button  connected  to  its  ends.  This  shank  may  be 
used  for  buttons  which  have  a  metal  shell  to  be  closed  in  upon  the  bevelled  edges  of  the 
ends,  or  the  shank  piece  may  be  otherwise  connected  to  the  face  part  of  the  button  F^. 
220  is  a  representation  of  a  shank  raised  out  of  a  small  disc  of  metal  5f<7,  intended  to  be 
soldered  to  the  disc  of  metal  forming  the  button,  or  it  may  be  otherwise  fixed  to  the 
back  •  fig  221  is  a  representation  of  another  shank  for  the  same  purpose,  having  only 


BUTTON  MANUFACTURE. 


291 


portions  of  metal  h  h,  for  soldering  or  otherwise  attaching  it  to  the  back  of  the  button, 
as  by  placing  a  ring  or  annular  piece  over  it  forming  the  back,  which  shall  be  confined 
to  the  face,  as  before  described  ;^y.  222.  is  a  representation  of  a  shank  raised  upon  a  dish 
or  bevelled  piece  of  metal,  and  is  intended  to  be  used  for  buttons  made  from  pearl-shelL 
horn,  wood,  paper,  or  other  substances.  The  back  part  of  the  button  has  a  dovetailed 
recess  formed  in  it  to  receive  the  dish-shaped  back,  which  is  pressed  into  the  recess,  the 
edges  ot  the  dish  being  expanded  in  the  dovetailed  parts  of  the  recess  by  the  ordinary 
means,  and  thereby  firmly  fixing  it  to  the  button,  as  shown  in  fig.  223.  ^ 

Having  now  explained  tlie  peculiar  form  of  his  improved  8hanks,he  proceeds  to  describe 
the  toos^or  punches  and  dies,by  which  he  cuts  the  disc  or  back  from  out  of  a  sheet  of  metal 
and  at  the  same  operation  produces  and  forms  the  shank  complete.  Fig.  224.  is  a  longitu- 
dinal section  taken  through  a  pair  of  dies  and  punches  when  separated;/a.  225.  is  a  similar 
section,  taken  when  they  are  put  together,  and  in  the  act  of  forming  a  shank  after  cutting 
^11  ^n^^r  997  •  ""^  *^^^"««  fr«"^  ^  .«heet  of  metal ;  fig.  226^is  a  face  view  of  thf 
punch ;  and  fig.  227.  is  a  similar  representation  of  the  counter  die,  with  the  tools  complete 
« IS  the  puncher  or  cutter,  and  b  the  counter  bed,  by  the  circuk;  edges  of  which  the  di^ 

tl  J?:^,tfn n  ^r'  ""^  ' k'  '^'"' '  ' ?f  ^'>  ^^^^  ^  ^^« «"tt^^  ^  (^Vol  which  the  uame^ 
the  button  maker  may  be  engraved      Fig.  228.  is  a  face  view  of  this  die  when  removed 

Tand  TC'Ju  '  ^«  i^V«"^^^^^^^«  ]V^/  die  c.  It  will  be  perceived  that  these  dies 
c  and  ^together  with  the  punch  and  bed,  compress  the  disc  of  metal  into  the  form 

ISr,?i'/f^'wf  ^^'^'^''^°'  that  shown  i^nthefigures,  as  before  stated. Tofth^ 
shape  used  for  buttons  to  be  covered  with  Florentine  or  thin  plate  metal,  in  a  round 
^ell  closed  m  upon  the  inclined  or  bevelled  edge  of  the  back;  .  is  the  cuttLn^nd 
shaping  punch  of  the  shank,  which  is  fixed  within  the  counter  die;  this  punch  cute 
through  the  njetal  of  the  d^sc,  and  forms  the  shank  as  the  dies  approach  nearer  together 
by  raising  or  forcing  it  up  into  the  recess  or  opening  in  the  die  c,  where  it  is  metl^y  tie 

Jihi  T  l^-  f  T"^  P'"''"^-^.  ^\'^  ^^  ?^  P"^^^  '^^  ^^i^h  compresses  the  upper  part 
of  the  shank  into  the  recess  g,  m  the  end  of  the  punch  ..  thereby  giving  the  shank  it« 
rounded  figure,  and  at  the  same  time  forming  the  other  part  of  the  sh^k  into  the  Re- 
quired shape  as  described  at /^rs.  212.  to  216.  The  ends  of  these  shaping  punches  fit  into 

Jn'l^I'T   I.     v'S  \'  J'"  -u  T'^Jy  ^^^  ?^^*"^^^  fig"^^«  «^  the  punches  designed  for 
forming  the  shank  first  described.  Fig.  229.  is  a  representation  of  the  punches  whfn  apart 
and  removed  out  of  the  dies:  fig.  230.  is  a  longitudinal  section  of  the  same ;  fig.  231  is 
another  view  of  the  punches  as  seen  on  the  top.     The  sharp  edge  of  the  rece^i  in  the 
punch  e,  comes  m  contact  with  the  cutting  edges  of  the  projecting  rib  i,  of  the  die  c,  and 
thereby  cuts  through  so  much  of  the  metal  as  is  required.    The  edge  k  of  this  die  keens 
for'c:  nn  h'  '"'^  of  the  shank  of  a  spherical  figure,  al  before  explalnfd,;hne  tL  p^^^^^ 
force  up  the  metal,  and  form  the  elevated  loop  or  shank  :uu  are  holes  made  through  the 
counter  die  (^  for  the  passage  of  clearing  pins,  which  force  out  the  shank  or  back  piece 
from  the  counter  die  when  finished ;  the  operation  of  which  will  be  shown  when  describ- 
ing the  machinery  hereafter.    There  are  adjusting  screws  at  the  back  of  the  punches  and 
dies,  by  wliich  they  can  be  regulated  and  brought  to  their  proper  position  one  to  the  other 
AJthough  he  has  shown  the  punches  which  form  his  improved  shanks,  fixed  into  and 
working  m  conjunction  with  the  punch  and  dies  which  cut  out  and  shape  the  discs  of 
metal  for  the  back  of  the  button,  yet  he  does  not  intend  to  confine  himself  to  that  mode 
of  using  them,  as  flat  blanks  or  discs  for  the  backs  of  buttons  may  be  cut  out  in  a 
separate  stamping  press,  and  afterwards  shaped  in  the  same  press  or  in  another  and  then 
brought  under  the  operation  of  the  punches  which  form  his  improved  shankk  fixed  in 
any  suitable  press.     This  last-mentioned  mode  of  producing  button  shanks  and  backs 
he  prefers  when  such  metals  are  employed  as  require  annealing  between  the  operations 
of  shaping  the  backs  and  forming  the  shank.     Fig.  232.  is  a  section  taken  through  a 
pair  of  dies,  in  which  the  operation  only  of  forming  the  shank  is  to  be  performed,  the 
backs  being  previously  shaped  m  another  press.     In  this  instance  the  punches  e  aid  f 

Tnl^Z  .^'''  f."^dtP-^«^«  "^  ^'l^^  "^^^^^  I'^^P  *^^°^  '"^  the  proper  position  toward 
each  other,  «ie  die  c  being  mounted  in  the  piece  n,  and  acting  against'^the  face  of  the 
guide  m.  The  blanks  or  backs  of  the  buttons  may  be  fed  into  these  dies  by  hand  or 
any  other  means;  and  after  the  shank  is  formed,  the  finished  back  can  be  pushed  out 
of  the  lower  die  by  clearing  rods  passed  through  the  holes  u  u,  and  removed  by  hand 
or  in  any  convenient  manner.  •'         ^ 

When  his  improved  shanks  are  formed  out  of  iron  or  other  metal  which  is  too  brittle 
to  allow  of  the  shank  being  forced  up  and  finished  at  one  operation  in  the  dies  and 
punches,  he  prefers  cutting  out  and  shaping  the  blank  or  back  of  the  button  first,  and 
l^^l  *n«ealing  it,  to  raise  or  force  up  the  portion  of  metal  to  form  the  shank  into  the 
shape  shown  mfig  233.,  that  is^  without  the  edges  of  the  metal  being  turned  to  prevent 
their  cutting  the  threads,  and  after  again  annealing  it,  to  bend  or  turfi  the  edges  into  the 
shape  shown  mfi^.  218  by  means  of  suitable  punches  in  another  press,  or  by  a  pair  of 
pmcers  and  punch  as  shown  mfig.  234,  which  is  a  side  view  of  a  small  apparatuTto  be 

2P2 


292 


BUTTON. 


^i^^^L. 


used  for  turning  the  edges  of  the  shank  by  hand,  with  a  partly  formed  shank  seen  under 
operation,  a,  is  the  upper  jaw  of  a  pair  of  pincers,  this  jaw  being  fixed  on  to  the  head 
of  the  standard  6  ;  the  under  jaw  <?,  is  formed  by  the  end  of  the  lever  or  handle  d,  which 
has  its  fulcrum  in  the  standard  b.  e,  is  a  small  punch,  passed  through  a  guide  hole  in 
the  head  of  the  standard,  one  end  projecting  into  the  jaws  of  the  pincers,  the  other 
against  a  piece/,  attached  by  a  joint  to  the  lever  d,  and  working  through  a  slot  in  the 
head  of  the  standard ;  this  piece  /,  has  an  inclined  plane  on  the  side  next  the  end  of 
the  punch,  which,  in  its  descent,  projects  the  punch  forward  against  the  top  of  the 
loop  of  the  shank,  (placed  at  ff,)  as  the  pincere  are  closed  by  forcing  down  the  lever  d, 
and,  in  conjunction  with  the  jaws  of  the  pincers,  compresses  the  shank  into  the  required 
form,  as  shown  at  A,  and  in  the  enlarged  ^^.  218.  A  spring,  i,  acts  against  a  pin  fixed 
into  the  punch  e,  for  the  purpose  of  bringing  it  back  as  the  jaws  open  after  forming  a 
shank.  Mgs.  2S5.  and  236.  represent  the  face  and  section  of  the  dies  mentioned  before 
for  cutting  the  slits  in  the  discs,  as  at^^.  217.  * 

Having  explained  the  peculiar  forms  of  his  improved  metallic  shanks  for  buttons, 
and  the  tools  employed  in  making  the  same,  he  proceeds  to  describe  the  machinery  or 
apparatus  by  which  he  intends  to  carry  his  invention  into  effect.     He  proposes  to  take 
a  sheet  of  metal,  say  about  30  or  40  feet  long,  and  of  the  proper  width  and  thickness, 
which  thm  sheet  is  to  be  wound  upon  a  roller,  and  placed  above  the  machine,  so  that  it 
can  be  easily  drawn  down  into  the  machine  as  required  for  feeding  the  punches  and 
dies.     Fiff.  237.  is  a  plan  view  of  a  machine,  intended  to  work  any  convenient  number 
of  sets  of  punches  and  dies  placed  in  rows.     Eleven  seta  of  punches  and  dies  are  re- 
presented, each  set  being 
constnicted  as  described 
under  Ji(/s.  224.  to  231. ; 
/g.  238.  is  a  side  view, 
and  Jig.  239.  a  longitudin- 
al section,  taken  through 
the  machine;  fgiL  240. 
and  241.  are  transverse 
sections   taken    through 
the  machine  between  the 
pimches     and     counter 
dies.  Jiff.  240.  represent- 
ing its  appearance  at  the 
face  of  the  punches,  and 
Jiff.  241.  the  opposite  view 
of  the  counter  dies,     a  a, 
are    the   punches;    b  b, 
the  counter  dies;    each 
being  mounted  in  rows 
in  the  steel  plates  c  c, 
fixed  upon    two   strong 
bars  d  and  e,  by  counter- 
sunk  screws    and    nuts, 
the    punches    and    dies 
being  retained  in  their 
proper  position   by  the 
plates,  which  are  screwed 
on   to  the  front   of  the 
steel    plates,    and    press 
against  the  collars  of  the 
punches  and  dies.     The 
bars  d  and  e  are  both 
momited  on  the  guide- 
pins  ff  ff,    fixed   in  the 
heads  h  h  of  the  fram^ 
which    guide-pins    pass 
through    the   bosses   on 
the  ends    of    the   bars. 
The  bar  d  is  stationary 
upon      the     guide-pins, 
being  fixed  to  the  heads 
A  A,  by  nuts  and  screws 
passed  through  ears  cast 
on  their  bosses.    The  bar 
e  slides  freely  upon  the 
guide-pins  ^  ^,  as  it  is 


BUTTON. 


293 


r*r 


moved  backwards  and  forwards  by  the  crank  i  t,  and  connecting-rods  J/  as  the  crank 
shaft  revolves.  The  sheet  of  thin  iron  to  be  operated  upon  is  placed,  as  before  stated, 
above  the  machine;  its  end  being  brought  down  as  at  a  a,  and  passed  between  the 


guide-rod  and  clearing  plate  k,  and  between  the  pair  of  feeding-rollers  /  /,  which,  by 
revolving,  draw  down  a  further  portion  of  the  sheet  of  metal  between  the  punches  and 
dies,  after  each  operation  of  the  punches. 

As  the  counter  dies  advance  towards  the  punches,  they  first  come  in  contact  with 
the  sheet  of  metal  to  be  operated  upon ;  and  after  having  produced  the  pressure  which 
cuts  out  the  discs,  the  perforations  of  the  sheet  are  pushed  on  to  the  ends  of  the  punches 
bj^  the  counter  dies ;  and  in  order  that  the  sheet  may  be  allowed  to  advance  the  car- 
nage which  supports  the  axles  of  the  feeding^oUers,  with  the  guide-rod  and'clearinff- 
plate,  are  made  to  slide  by  means  of  the  pin  m,  which  works  in  a  slot  in  the  slidinc^ 
piece  n,  bearing  the  axis  of  the  feeding-roller  1 1,  the  sUde  n  being  kept  in  its  place  <m 
the  framework  by  dovetailed  guides,  shown  in  Jiff.  241. 

When  the  counter  dies  have  advanced  near  to  the  sheet  of  metal,  the  pin  m  comes 
in  contact  with  that  end  of  the  slot  in  the  piece  n,  which  is  next  to  the  punches,  and 
forces  tJie  carriage  with  feed-rollers  and  clearing  plate,  and  also  the  sheet  of  metal,  on- 
wards, as  the  dies  are  advanced  by  the  reaction  of  the  cranks ;  and  after  they  have  cut 
out  the  discs,  and  raised  the  shanks,  the  sheet  of  metal  will  remain  upon  the  punches  • 
and  when  the  bar  e  returns,  the  finished  backs  and  shanks  are  forced  out  of  the  coun- 
ter dies,  bv  the  clearing-pins  and  rods  o  o,  which  project  through  the  bar  c,  and  through 
the  holes  before  mentioned  in  the  counter  dies;  these  clearing-pins  being  stationary  be- 
tween the  bars  p  p,  mounted  upon  the  standard  q  q,  on  the  cross  bar  of  the  frame,  as 
shown  in  fiffs.  237.  239.  240.  Immediately  after  this  is  done,  the  pins  m  come  in  con- 
tact with  the  other  ends  of  the  slots  in  the  pieces  w,  and  draw  back  the  feeding-rollers 
I  <,  together  with  the  clearing-plate  k,  and  the  sheet  of  metal,  away  from  the  punches 
into  the  position  represented  in  the  figures. 

At  this  time  the  feeding  of  the  metal  into  the  machine  is  effected  by  a  crank-pin  r, 
on  the  end  of  the  crank-shafts  coming  in  contact  with  the  bent  end  of  the  sliding-bar  i^ 
supported  in  standards  1 1;  and  as  the  crank-shaft  revolves,  this  pin  r  forces  the  bar  « 
forward,  and  causes  the  tooth  or  pall  u,  on  its  reverse  end,  to  drive  the  racket-wheel  t>, 
one  or  more  teeth ;  and  as  the  racket-wheel  v  is  fixed  on  to  the  end  of  the  axle  of  one 
of  the  rollers  I,  it  will  cause  that  roller  to  revolve ;  and  by  means  of  the  pair  of  spur- 
pinions  on  the  other  ends  of  the  axles  of  the  feeding-rollers,  they  will  both  revolve 
simultaneously,  and  thereby  draw  down  the  sheet  of  metal  into  the  machine.     It  will 
be  perceived  that  the  standards  which  support  the  clearing-plate  and  guide-bar  are  car- 
ried by  the  axles  of  the  feeding-rollers,  and  partake  of  their  sliding  motion ;  also  that 
the  clearing-pins  o,  are  made  adjustable  between  the  bars  p,  to  correspond  with  the 
counter  dies.     There  is  an  adjustable  sliding-stop  x  upon  the  bar  «,  which  comes  in 
contact  with  the  back  standard  t,  and  prevents  the  bar  s  sliding  back  too  far,  and  con- 
sequently regulates  the  quantity  of  sheet  metal  to  be  fed  into  the  machine  by  the  pall 
and  ratchet-wheel,  in  order  to  suit  different  sizes  of  punches  and  dies.     In  case  the 
weight  of  the  bar  c,  carrying  the  counter  dies,  should  wear  upon  its  bearings,  the 
guide-pins  g  g,  have  small  friction-rollers  y  y,  shown  under  the  bosses  of  this  bar,  which 
fnction-rollers  run  upon  adjustable  beds  or  planes  «  2,  by  which  means  the  guide-pins 
may  be  partially  reUeved  from  the  weight  of  the  bar  c,"and  the  friction  consequently 
diminished- 

Buttons  op  Horn.— Mr.  Thomas  Harris  obtained  in  April,  1841,  a  patent  for  im- 
provements in  the  manufacture  of  horn  buttons,  and  in  their  dies.  His  invention 
delates,  first,  to  a  mode  of  applying  flexible  shanks  to  horn  buttons ;  secondly,  to  a  mode 
of  ornamenting  horn  buttons,  by  inlaying  the  front  surface  thereof;  thirdly,  to  a  mode 
of  ornamenting  what  are  called  horn  buttons,  by  gilding  or  silvering  their  surfaces ; 
fourthly,  to  a  mode  of  constructing  dies,  by  applying  separate  boundary  circles  to  each 
engraved  surface  of  a  die,  by  which  the  process  of  engraving,  as  well  as  the  forming 
of  accurate  dies,  will  be  facihtated ;  fifthly,  to  a  mode  of  constructing  dies,  used  in  the 


294 


BUTTON. 


manufacture  of  horn  buttons,  \rliereby  the  horn  or  hoof  employed  will  not  be  per- 
mitted to  be  expressed  beyond  the  circumference  of  the  button. 
Fig.  242.  represents,  in  section,  a  pair  of  dies,  a  and  b,  used  in  producing  the 
242  S45  250  S54  357 


improved  horn  buttons,  according  to  the  first  improvement;  the  upper  die  a  is  made 
to  produce  the  back  surfaces  of  the  buttons,  and  the  recess  or  groove  for  receiving  the 
flexible  shank.  Fig.  243.  shows,  in  section  and  back  view,  the  form  of  a  button  nro- 
duced  by  the  diea  .  *^ 

Buttons  thus  formed  are  now  ready  to  receive  flexible  shanks;  and  if  the  buttons 
are  to  have  plain  smooth  front  surfaces,  then,  in  fixing  the  flexible  shanks,  the  same 
kind  of  under  die  b  may  be  used;  but  if  the  front  surface  of  the  button  is  to  be  em- 
bossed or  ornamented,  then,  in  place  of  that  die  a  similar  one  having  engraved  or 
suitably  ornamented  surfaces,  is  to  be  used.  When  fixing  the  shanks  to  buttons,  the 
lower  or  face  die,  containing  the  previously  formed  buttons,  is  to  be  heated  till  a  drop 
of  water  will  nearly  boil  upon  it.  ^ 

The  shank  is  applied  as  follows:— a  metal  shell  or  collet  a  (Beefig.  244  )  is  placed 
oyer  the  flexible  shank  b,  and  a  plate  of  metal  c  is  laid  under  the  shank-  these  are 
placed  in  the  groove  or  recess  of  the  button,  which  had  been  previously  heated 
in  the  lower  die;  the  upper  die  a.  Jig.  245.,  is  then  to  be  placed  on  the  lower  dien,  and 
the  two  submitted  to  pressure,  until  they  become  cool,  when  the  shank  will  be  firmlv 
attached,  as  shown  &tfig.  246.,  and  the  bottom  may  be  finished  in  the  usual  way 

The  second  part  of  the  invention,  which  relates  to  a  mode  of  ornamenting  horn  but- 
tons, by  mlaymg  the  front  surface  thereof;i8  performed  in  a  manner  similar  to  what  has 
been  above  descnbed,  for  fixing  flexible  shanks,  and  consists  in  first  forming  the  front 
face  or  surface  of  a  button,  in  suitable  dies,  for  providing  a  recess;  and  then  by  a 
second  pressure  in  dies,  to  fix  the  ornamental  surface ;  and,  when  desired,  the  surround- 
ing front  surface  of  the  button  maj  be  embossed.  Fig.  247.  is  a  longitudinal  section  of  a 
pair  of  dies,  for  forming  a  recess  in  the  face  of  a  button.  Mg.  248.  shows,  in  front  view 
and  section^  a  horn  button,  produced  by  these  dies.  Mg.  249.  shows  a  metal  ornament 
to  be  inlaid  or  fixed  in  the  front  surface  of  the  button,  but  it  should  be  stated  that  the 
ornamenting  surface,  to  be  fixed  in  the  front  surface  of  the  button  may  be  of  pearl  or 
other  material ;  and  the  size  and  device  varied  according  to  taste.  Hg  250  shows  in 
section  a  i)air  of  dies,  for  giving  the  second  pressure  for  affixing  the  ornamental  surface- 
and,  if  desired,  the  remaining  front  surface  of  the  button  may  be  ornamented,  by  ha  vine 
the  lower  die  engraved,  or  otherwise  suitably  ornamented.  Mg,  251.  shows  in  front 
view  and  section  a  button  made  according  to  this  part  of  the  invention. 

The  third  part  of  the  invention  relates  to  a  mode  of  ornamenting  horn  buttons,  bv 
gilding  or  silvermg  their  surfaces^  -Dus  is  effected  by  applying  a  suitable  cementing 
or  adhesive  material  with  a  soft  brush  to  the  button,  in  order  that  gold  or  silver  leaf 
may  be  attached  to  its  surface.  The  cementing  or  adhesive  material  preferred  to  be 
used  is  dressing  varmsh  rendered  sufficiently  liquid  by  essence  of  turpentine  •  and  when 
the  varnish  is  nearlv  dry,  gold  or  silver  leaf  is  applied  thereto,  and  pressed  in  the  same 
manner  as  practised  when  gilding  and  silvering  other  surfaces;  by  thus  treating  horn 
buttons,  a  very  novel  manufacture  of  that  description  of  buttons  may  be  produced. 

The  fourth  part  of  this  invention  relates  to  the  construction  of  dies  used  in  the 
manufacture  of  horn  buttons.    Mg.  252.  is  a  section  of  a  die,  constructed  according  to 


BUTTON. 


295 


this  j>art  of  the  invention ;  And  Jig.  253.  is  a  section  showing  the  die  without  the  bound- 
ing circles,  which  confine  the  pattern ;  /  is  the  die  engraved  at  the  parts  g,  g ;  around 
each  of  which  engraved  surfaces  are  circular  grooves  or  recesses  to  receive  the  bounding 
circles,  h,  h,  which  fit  accurately.  B^  the  after  insertion  of  these  circles,  the  workman 
is  not  confined  to  move  his  graver  within  the  bounding  line,  as  that  line  is  not  present 
when  engraving  the  plate;  and  the  graver  may  pass  beyond,  and  the  grooves  and  the 
bouudmg  circles  may  readily  be  made  with  great  accuracy  to  each  of  the  engraved 
surfaces. 

The  fifth  part  of  the  invention  also  relates  to  a  mode  of  constructing  dies,  for  the 
manufacture  of  horn  buttons,  and  consists  in  forming  the  dies,  so  that  the  bounding 
circle  shaU  be  of  a  sufficient  depth  for  the  counter  die  to  slide  within  it,  and  fit  acci^ 
rately  in  order  that  the  circumference  of  each  button  shall  be  smoothly  and  accurately 
formed,     i^^.  254.  represents  in  section  two  dies,  and  one  counter  die,  made  according 
to  this  part  of  the  invention ;  Jig.  255.  shows  one  of  the  dies,  in  plan  and  section ;  and 
^g.  256.  a  plan  and  section  of  a  counter  die,  suitable  for  flexible  shank  buttons.     A,  h, 
are  the  dies,  having  the  engraved  surfaces  i,  i,  on  separate  circular  discs  of  metaL  such 
as  have  heretofore  been  used;  J,  is  a  counter  die,  and  k,  a  tube,  within  which  the 
counter  die  is  held,  the  object  of  this  tube  being  to  guide  the  projecting  edges  /  /  of 
the  dies  as  shown,  and  thus  keep  the  dies  and  counter  dies  correct  to  each  other   Fiq  257 
is  a  section  of  two  dies  h,  and  a  counter  diej;  but  in  this  case  the  tube  k  is  dispensed 
with,  the  dies  being  deeper  sunk,  and  thus  guiding  the  counter  die  correctly.     By  the 
use  of  these  dies,  the  edges  of  horn  buttons  will  be  more  accurately  formed,  and  con- 
sequently require  less  finishing.     This  description  of  dies  may  be  made  according  to 
the  mode  described  in  the  fourth  part  of  this  invention ;  that  is,  by  forming  the  boundary 
circle  separately,  as  will  be  understood  by  referring  to  Jig.  258.,  which  is  a  side  section  of 
a  die  complete,  with  its  boundary  circle  formed  in  a  similar  manner  to  that  described 
above.     Mg.  259.  represents,  in  plan  and  section,  a  variation  in  the  means  of  affixing  a 
separate  bounding  circle  to  each  engraved  surface ;  and  it  is  suitable  for  working  with- 
out the  tube.     In  using  these  dies  they  are  to  be  heated  but  slightly,  whether  for 
buttons  with  metal  shanks,  or  to  receive  flexible  shanks,  and  are  to  be  pressed  as  here- 
tofore.    The  patentee  claims,  firstly,  the  mode  of  manufacturing  horn  buttons  with 
flexible  shanks,  by  first  forming  buttons  by  pressure  and  heat,  and  then  by  a  second 
pressure  in  dies,  to  affix  flexible  shanks  thereto,  as  above  described.     Secondly,  the 
mode  of  ornamenting  horn  buttons,  by  causing  suitable  surfaces  to  be  affixed  in  the 
front  surfaces,  by  pressing  the  buttons  with  the  ornaments  in  dies,  as  above  described. 
Thirdly,  the  mode  of  ornamenting  horn  buttons  by  gilding  and  silvering  their  surfaces 
as  described.     Fourthly,  the  mode  of  constructing  dies  used  in  the  manufacture  of  horn 
buttons,  by  applying  separate  bounding  circles  to  each  engraved  surface  for  a  button  • 
and  fifthly,  the  mode  of  manufacturing  horn  buttons  in  dies,  wherein  the  horn  or  hoof 
is  prevented  from  being  expressed  at  the  circumference  of  the  buttons  as  described. 

Buttons,  Covered.  Mr.  Joseph  Parkes  obtained,  in  1840,  a  patent  for  improve- 
ments in  the  manufacture  of  covered  buttons  made  by  dies  and  pressure,  by  the 
application  of  horn  as  a  covering  material  The  process  resorted  to  by  the  patentees 
for  carrying  out  this  invention,  is  very  similar  to  that  pursued  in  manufacturing 
Florentine  buttons ;  such  modifications  being  applied  as  are  rendered  necessary 
for  adapting  such  process  to  the  peculiar  nature  of  the  material  employed  for  covering 
the  face  of  each  button,  a,  fig.  260.  shows  a  plan  of  a  disc  of  iron  plate,  with  four 
projecting  points,  which  is  formed  by  suitable  dies  in  a  fly-press,  as  is  well  under- 
stood; the  points  are  then  turned  down,  and  the  disc  a,  is  sunk  into  the  shape 
shown  at  Jig.  261.,  and  two  such  sunk  discs  are  applied  to  the  internal  core  of  the 
button-board  of  each  button ;  b,  Jig.  262.,  shows  a  plan  and  edge  view  of  a  circular  disc 
of  button-board,  suitable  for  forming  the  internal  core  of  a  button. 

The  dies  being  placed  in  suitable  presses,  as  is  well  understood  in  using  similar 
dies  in  manufacturing  Florentine  or  other  covered  buttons,  one  of  the  sunk  dies  a 
is  placed  in  the  under  die,  with  the  points  upwards,  having  a  disc  of  button-board 
placed  on  the  points,  as  shown  at  Jig  263. ;  the  upper  die  or  punch  is  then  caused  to 
descend  and  press  the  button  board  b  into  the  shape  shown  &tjig.  264. ;  which,  when 
thus  formed,  is  to  have  a  die  a,  applied  on  the  other  side,  as  shown  at  *Jig.  265.     The 
disc  a,  to  be  next  fixed  to  the  button-board,  is  placed  in  a  suitable  die,  the  disc  which 
has  already  been  fixed  being  upwards ;  the  die  or  punch  is  now  to  be  pressed  down, 
which  will  produce  the  button-board,  with  the  discs  a  a  on  either  side,  into  the  shape* 
shown  at/^r.  266. ;  and  it  will  be  seen,  that  one  of  the  discs  will,  by  the  shape  of  the  die 
be  sunk  concave,  whilst  the  other  disc  a,  on  the  other  side,  will  be  formed  convex,  or 
according  to  the  figure  of  the  face  of  the  intended  button. 

The  core  of  button-board, /g^r.  266.,  is  now  ready  for  being  inserted  into  the  fabric 
which  IS  to  become  the  flexible  shank  of  the  button,  and  which  flexible  shank  is  formed 
by  smking  a  portion  of  fabric  in  suitable  dies,  as  is  well  understood  when  making 


296 


BUTTON. 


Uif  button  h«'  ^7  Florentine  or  other  covered  buttons;  and  the  shank  being  so  sunk, 
the  button-board  or  core,>5r.  266.,  is  to  be  placed  thereon,  with  the  concave  surface 

63  6  «M7 

S70  871  S73 


inserted  into  the  metal  shell  cL  268  and  fl  ''''''^'^'I'S  the  core,  which  Is  next 
are  pressed  together,  and  the  paftlv  mkn,^L?  /w.  ^"''^^  P^*'"^  ^°  *  suitable  die, 
consisting  of  the  shank  contafnEL^^^  ^^^•'  ^^"  ^^  produce  J 

shell  c,  which,  by  the  die  has  Tff  P^tlT'  T?'"*'^  ""^  ^^  ^^°*  surface  with  the  met2 
The  bitton,  thus  for  fo^Seris  now fr^^^^^  Tt^'  ^"^"V^  ^^'  ^'''^^'  «^««k. 

horn,  which  is  performeTfnlhe  fXwingTannr-^^^^^^^^^^  %""°  i'i\^^  ^^ 

cut  out  by  suitable  dies,  the  ciroumfJZnr^u^^^^^'  V^:'  ^^^^*  *  ^^^  ^f  horn, 

over  the  m^ould,/,.  26?  tt  hTn^mlrnot  be  P^^^^^^^^^  ^^^f  Ih^'  "  '^^lS 

for  affixing  the  covering  of  horn  to  the  bntfnn  ?v.!  «  n^  ,  *.^'^?'  271.,  shows  a  collet, 

his  hand  to  rest  for  a  verv  short  Urn^  „„  tlf"  *""*"*  *¥  ""e  workman  can  just  boar 

at  ;j^*.  273  and  274.  which  consist  of  fh!  f  k  ^^^^^J^t^o^^^cjion  of  the  parte  shown 
edge  of  the  tube  i  is  made  beUr^^^^^^^^^^  ^""^  V^  ^^"  P"^"^  ^^  ^'^  /  The  lower 
pressed  on  the  back  oTthe  bu  toTlnd  1^^^  *"  '^"f"  >^"  '"^"^P"^  ^^^^^  <^o  »>« 
forced  through  the  horn  in  the  bSLn  .n:^  -'^  ""•  P^.f^  "^  *'  ^^  "^"^  *'^^  ««"et  to  b« 
the  tube  I,  which  wS  punch  is  wVfr^^-'rtK^i'''^P*^^^  *^"  "^"^*  ie  placed  ia 
figure  represents  the  die  /Z  punch  A  ?n  f h  ^".-l-"  *'  ^  '^^r^  ?.*  >^-  ^^^-^  which 
forced  the  parte  into  the  die  g     and  tht  fi  ^^ond^t^on  just  described,  after  having 

and  the  puSch  or  die  j  placed'in  ?h  A  K  ^"'%*^  n  t"""^'  *^"  ^"^^  ^  ^'^^  *  «^"et  I 
the  pressure  of  the  puuXh  wtr ^^^^^^  *°"  *^"^g«  «^«  ^^  »  ^o-^^i^ion  to  receive 
die  J,  before  the  hom  has  Ln  UdeLl^  wu  *  ^^P^e8s^re  coming  on  the  punch  or 
over  the  die  or  punch?  conL^uentlv  IT  ^^i*''^  ^""^t  ^  ^>'  ^^"^^  ^^"^^  ^  ^«  pl««e<l 
force  down  the  tube  i,  aAd  cause  ktoLTw  fV'  P^'*'  ?  'i  "^^^^  ^^^  ^«««^^*^'  ^*^  ^i" 
the  back  of  the  mould  of  the  butt^  when  the Vunf^u^  Mi^k"'"^  "!;^  P''^^  "^^°»  *^^ 
block  K  removed,  which  will  leave  all  thin^  in  tlf.-.-  ^'^l  ^^  ""^'^^^  '^'^'"'  *"^  ^« 
again,  the  bringing  down  of  ire  punch  uTillVi^  PTyl^'^i"  '^"^'^  ^V^'  ^^C- ;  and  then 
force  the  collet  into  the  butto^the  die  ,  bTin.  r^f!"  ^5  ^\Z'  P\^^^  '  ^  ^^««^»^  «°d 
pin  z,  passing  through  a  slit  formed  therein  3.'  li?^  ""r*^!  *"^^  '  ^^  °^«*««  «f  *!»« 
S.  theUe  f  but  pr^evente  itrcTminf  o?t  of  Th^'^^^^^^^^  '^^  ^1^  '  rising  and  falling 

the  button  to  befinishedisinserte^iL^^t^die.^th^^^^^^^^^ 


CABLE. 


297 


When  the  front  of  the  button  is  to  be  plain,  the  dise  of  hom  should  be  poUshed  before 

orTnamen  fed  r"tr '  Yj""'"  ""^^^  «""^  '  •"'"°''>  "■»  ^'^^iyTenM 
or  oi  naraented  die  the  polishing  is  not  necessary.     The  button  being  thus  made  i«  f^ 

„o^t.Tdl:semptyeTltrsetrer„l^^^^^^ 

used  in  the  manufacture  orothL7ov^edbutt„*^  I^"^/""'!""  '''*!,''»™g  been  before 
so  loni?  as  the  n«..nli„..  „!...*     ^"Terea  buttons ;  nor  does  he  confine  himself  thereto. 

manXTurin/covered  t»  ""!?  T""."-"  "'  '^e  invention  be  retained ;  viz.  that  of 
.TeerWn"r§i:rv:fnglat:^iar  HeXtlth^^^^^^^^  'V"  Tl'^'""  "^r*"" 
rin«coveredbuttonsbytgeappU:aiio?:ftr^:rvt:i--X^^^ 

taberrces  aW  o^e  tW,^™fV-  T'"1\*5'  """^  "«  ">  !>»  ""de,  with  swells  or  prZ 
are  we?ded  to^^Hr  .1.  f  ^'''*""  '^8:"'  '*''""  "^"^  »f  *eir  ends,  so  that  when  these 
tt"  Tuttleaf^fn^  'Suoh  -h'^"'';^P''*k  "^  *'  '^  ''<'*^  ^--^  *«  dicker  at  the  ends  of 
•ny  other  meLr^  Wh.^  ?..  f  ^?  "''7/  5'*.  *^"™<''^  "'  """^  by  rolling,  swa^^ing,  or 
.tr{t:Wfi"edS,os^tt"'ml'ddl':'^  "  "^''''''  '*  ""^  ""  ^'-gtbened, ly  a  tfaef'or 

to  Martinimfo  and  (^,^«?1  '  ""^^  '5P|!^^"-  ^^-^^^^  ^  ^^^^^^  ^^  ^^is  ship  from  En&and 
a^ohorpHn^lf  ,^-  ^"?^*^«"Pe  and  home  again,  in  the  course  of  four  months,  having 
h?8  rkk  Z7ll?-'T  T'^  ^^"jty  of  gromxd  without  any  accident.  He  muSed 
cab  eT  not  nn?vr''^  '''*^"'  P'^t  '^*  ^^^^  °^^g^<^  ^^  substituted  for  hemp  in  mak  S 
nh«  n^  n  ?  ^  ^T  ™««"?g  vessels,  but  for  the  standing  rigging.  Since  this  per  of 
?he  tw^.^H  1-^T'''  ^T  "S^^'T«"y  introduced  into  aU  the  shi|t  of  the  ^yal  nav^^^ 

materialTf  t'ie"l?e,?oI;»ir'''^r'^  '"•  ""=•  '"r^^<'t"^^' of  iron  cable  is,  to  p««ure  . 
Tain  In  order  L  o^?,^!  ^'  ^"^  '"  """«  "-  "'^"J"'  '» ''«<'? '"  ^'^  the  direction  of  the 
theTik^ltbe'^ptm  Sr^:?^^^^^^^^^^^         -  ^^    ^"^  ^-'  '-  <>' 


278  H 


^ 


i.et  A  B,jiff  278.,  be  a  circular  link  or  ring,  of  one  inch  rod  iron  the 
rrouaronl'-r^  "''^.^  ring  being  islnches,  and  the  inner  9 
c  D  nnlHn?^  f  ^  ^T^'  be  applied  to  the  two  pointe  of  the  link 
thP  C«^  ^^^yd^  E,  and  D  towards  f,  the  result  will  be,  when 
lil/n  ''  ^^ffieiently  intense,  that  the  circular  form  of  the  link 
n«r«n!i  ^'T^^'^  '°^*'  ^''^*^^''  ^«™  wit^  tw«  round  ends  and  two 
iWnr  ^^\'^  seen  m  /^.  279.     The  ratio  of  the  exterior  to  the 

Wpr  t£'"P^''^''  I^'t  ^^«  originally  as  15  to  9,  or  5  to  3,  is  no 
longer  the  same  in  Aa.  279.     Rpn^^  th^rZ.  w;ii  k^  .  U..„,.^..„.' ....  • 


Vol.  L 


— V  lonrro,.  ♦v.V    "^       ••"  ^     ^"  **""  "I igiuaiiy  as  10  lo  y,  or  5  to  3,  is  no 
■S^!3!  1  ^^  same  in /^.  279.     Hence  there  will  be  a  derangement  in 

JSfJthe  relative  position  of  th^  nnmT.«,,^«f  ^„.*:.i.„    „.,^  °,^.  /  .. 

— ^  their  cohesion 

In  Jiff.  278.  the  segment  m  n  of  the  outside  periphery  teing 


hhJ^r.  1  *• ^..J'y'  ^'^'     -neuce  mere  win  De  a  derangement  in 

tl.!,V  !  k""®-  Position  of  the  component  particles,  and  consequently 
their  cohesion  will  be  progressively  impaired,  and  eventually  d^ 
siroyed.     in  fig.  278.  the  segment  m  n  of  the  outside  periphery  being 


•^JT.Ti/': 


298 


CABLE. 


"^lual  to  3  inches,  the  corresponding  inside  segment  will  be  |  of  it,  or  1  *  inches.  If 
Ais  portion  of  the  link,  in  consequence  of  the  stretching  force,  comes  to  be  extended 
into  a  straight  line,  as  shown  in  fig.  279,  the  corresponding  segments,  interior  and 
exterior,  must  both  be  reduced  to  an  equal  length.  The  matter  contained  in  the  3 
inches  of  the  outside  periphery  must  therefore  be  either  compressed,  that  is,  condensed 
into  1|.  inches,  or  the  inside  periphery,  which  is  only  ]1  inches  abready,  must  be  extended  to 
3  inches ;  that  is  to  say,  the  exterior  condensation  and  the  interior  expansion  must  take 
place  in  a  reciprocal  proportion.  But,  in  every  case,  it  is  impossible  to  effect  this  con- 
traction of  one  side  of  the  rod,  and  extension  of  the  other,  without  disrupture  of  the  link. 
Let  us  imagine  the  outside  periphery  divided  into  an  infinity  of  points,  upon  each  of 
which  equal  opposite  forces  act  to  straighten  the  curvature :  they  must  undoubtedly  occa- 
sion the  rupture  of  the  corresponding  part  of  the  internal  periphery.  This  is  not  the 
sole  injury  which  must  result ;  others  will  occur,  as  we  shall  perceive  in  considering  what 
passes  in  the  portion  of  the  link  which  surrounds  c  n^fig.  279,  whose  length  is  A\  inches 
outside,  and  2LL  inside.  The  segments  m  p  and  n  o,  fig.  278  are  actually  reduced  to 
semi-circumferences,  which  are  inside  no  more  than  half  an  inch,  and  outside  as  before. 
There  is  thus  contraction  in  the  interior,  with  a  quicker  curvature  or  one  of  shorter 
radius  in  the  exterior.  The  derangement  of  the  particles  takes  place  here,  in  an  order 
inverse  to  that  of  the  preceding  case,  but  it  no  less  tends  to  diminish  the  strength  of  that 
portion  of  the  link;  whence  we  may  certainly  conclude  that  the  circular  form  of  cable 
Jinks  is  an  extremely  faulty  one. 

Leavmg  mtUers  as  we  have  supposed  vafig.  278,  but  suppose  that  g  is  a  rod  introdnced 
mto  the  mail,  tUidering  its  two  opposite  points  a  b  from  approximating.     This  circum- 

280     stance  makes  a  remarkable  change  in  the  results.    The  link  puUed  as 

above  described,  must  assume  the  quadrilateral  form  shown  in  fig.  280. 
It  offers  more  resistance  to  deformation  than  before ;  but  as  it  may  still 
suffer  change  of  shape,  it  will  lose  strength  in  so  doing,  and  cannot 
therefore  be  recommended  for  the  construction  of  cables  which  are  to  be 
exposed  to  very  severe  strains. 
Supposing  still  the  link  to  be  circular,  if  the  ends  of  the  stay  comprehended  a  larger 
portion  of  the  internal  periphery,  so  as  to  leave  merely  the  space  necessary  for  the  plan 
of  the  next  link,  there  can  be  no  doubt  of  its  opposing  more  effectively  the  change  of 
form,  and  thus  rendering  the  chain  stronger.  But,  notwithstanding,  the  circular  portions 
which  remain  between  the  points  of  application  of  the  strain  and  the  stay,  would  tend 
always  to  be  straightened,  and  of  consequence  to  be  destroyed.  Besides,  though  we 
could  construct  circular  links  of  sufficient  strength  to  bear  all  strains,  we  ought  still  to 
reject  them,  because  they  would  consume  more  materials  than  links  of  a  more  suitable 
form,  as  we  shall  presently  see. 

The  effect  of  two  opposite  forces  applied  to  the  links  of  a  chain,  is,  as  we  have  sees, 
to  reduce  to  a  straight  line  or  a  straight  plane  every  curved  part  which  is  not  stayed : 
whence  it  is  obvious  that  twisted  links,  such  as  Brown  first  employed,  even  with  a  stay 
in  their  middle,  must  of  necessity  be  straightened  out,  because  there  is  no  resistance  in 
the  direction  opposed  to  the  twist.  A  cable  formed  of  twisted  links,  for  a  vessel  of  400 
tons,  stretches  30  feet,  when  put  to  the  trial  strain,  and  draws  back  only  10  feet.  This 
elongation  of  20  feet  proceeds  evidently  from  the  straightening  of  the  twist  in  each  link, 
which  can  take  place  only  by  impairing  the  strength  of  the  cable. 

From  the  preceding  remarks,  it  appears  that  the  strongest  links  are  such  as  present,  in 
their  original  form,  straight  portions  between  the  points  of  tension ;  whence  it  is  clear 
that  links  with  parallel  sides  and  round  ends  would  be  preferable  to  all  others,  did  not 
a  good  cable  require  to  be  able  to  resist  a  lateral  force,  as  well  as  one  in  the  direction 
of  its  length. 

Let  us  suppose  that  by  some  accident  the  link^^.  279.  should  have  its  two  extremities 
281  >^^Sv  pulled  towards  y  and  z,  whilst  an  obstacle  x,  placed  right  opposite  to 

its  middle,  resisted  the  effort.     The  side  of  the  link  which  touches  x 
would  be  bent  inwards ;  but  if,  as  in^^.  281.,  there  is  a  stay  a  o  b,  the 
I  two  sides  would  be  bent  at  the  same  time ;  the  link  would  notwith- 
standing assume  a  faulty  shape. 
In  thus  rejecting  all  the  vicious  forms,  we  are  naturally  directed  to  that  which  deserves 
the  preference.     It  is  shown  in^^.  282.     This  link  has  a  cast-iron  stay  with  large  ends ; 

it  presents  in  all  directions  a  great  resistance  to  every 

change  of  form ;  for  let  it  be  pulled  in  the  direction  a  6, 

Wgainst  an  obstacle  c,  it  is  evident  that  the  portions  d  e 

'and  d  f,  which  are  supported  by  the  parts  ff  e  and  a  f 

cannot  get  deformed  or  be  broken  without  the  whole  link 

giving  way.    As  the  matter  composing  g  e  and  gf  cannot 

be  shortened,  or  that  which  composes  d  e  and  df  be  lengthened,  these  four  sides  will 


'^m 


283 


-v.,^-.>-^. 


CABLE. 


299 


remain  necessarily  in  their  relative  positions,  by  virtue  of  the  large-ended  stay  K 
whose  pronle  is  shown  mjig.  283. 

We  have  examined  the  strength  of  a  link  in  every  di- 
rection, except  that  perpendicular  to  its  plane.     Fig.  284. 
represents  the  assemblage  of  three  links  in  the  above 
B  predicament ;  but  we  ought  to  observe,  that  the  ob- 
stacle c,  placed  between  the  links  a  b,  must  be  neces- 
sarily very  small,  and  could  not  therefore  resist  th« 
pressure  or  impact  of  the  two  lateral  links. 
,            ,.                         Process  of  manufacturing  iron    cables. — ^The   imple- 
ments and  operations  are  arranged  in  the  following  order- 

*i.  1-  ^/«^«^!?f  atory  furnace  (see  Iron),  in  which  a  number  of  rods  or  round  bars  of 
the  best  possible  wrought-iron  and  of  proper  dimensions,  are  heated  to  bright  ignition. 

2.  The  cutting  by  a  machine  of  these  bars,  in  equal  lengths,  but  with  opposite  bevek 
o    ?.u    V     ?•  ^^^T'*^  crossing  and  shcing  of  the  ends  in  the  act  of  welding. 

3.  Ihe  bending  of  each  of  these  pieces  by  a  machine,  so  as  to  form  the  Unks :  th« 
last  two  operations  are  done  rapidly  while  the  iron  is  red-hot 

4.  The  welding  of  the  links  at  small  forge  fires,  fitted  with  tools  for  this  express  pur 
pose,  and  the  immediate  introduction  of  the  stay,  by  means  of  a  compound  lever  pJess 

5.  Proving  the  strength  of  the  cables  by  an  hydraulic  press,  wofked  by  two  mei 
turning  a  wmch  furnished  with  a  fly  wheel.  j  iu« 

■nie  furnace  is  like  those  used  in  the  sheet-iron  works,  but  somewhat  larger,  and 
needs  no  particular  description  here.  * 

Figs.2%6.  and  286.  are  a  plan  and  elevation  of  the  shears  with  which  the  rods  are  cut  into 


equal  pieces  for  forming  each  a  link.  It  is  moved  at  Mr.  Brunton's  factory  by  a  smal 
steam  engine,  but,  for  the  sake  of  simplicity,  it  is  here  represented  woried  by  foui 
frL"i;^nHi*i^''yr''  ^V*  ?t^v  ^ '''  ^°^  establishment.  These  must  be  relieved  howev« 
on.T«3^.  "^  ^'"'  '  ^t'^.''^  ^*^^  «^^*^'^'  machine  is  calculated  to  require  nearly 
b:L^rfratl^Wd^^^^^  ^^^  ^^^^^  ^^  ^'^^^^  ^^  ^^^  neighbourhood  of 

A  and  b  are  the  two  cast-iron  limbs  of  the  shears.     The  first  is  fixed  and  th'.  kjcouc. 


2Q2 


300 


CABLE. 


IB  moveaWe  by  means  of  a  crank  shaft  c;  driven  by  a  heavy  fly-wheel  weighing  7  or  8 
cwt 

The  cutting  jaws  g  are  mounted  with  pieces  of  steel  which  are  made  fast  by  bolts, 
and  may  be  changed  at  pleasure. 

E,  the  bar  of  iron  to  be  cut.  It  is  subjected,  immediately  upon  being  taken  out  of 
the  fire,  to  the  shears,  xmder  a  determinate  uniform  angle,  care  being  taken  not  to  let 
it  turn  round  upon  its  axis,  lest  the  planes  of  the  successive  incisions  should  become 
unequal. 

F  18  a  stop  which  serves  to  determine,  for  the  same  kind  of  chain,  the  equality  of 
length  in  the  link  pieces. 

Figs.  287,  288,  289,  plan  and  elevations  of  the  machine  for  bending  the  links  into  an 
elliptic  form.     It  is  represented  at  the  moment  when  a  link  is  getting  bent  upon  iL 


288 


A  is  an  elliptic  mandrel  of  cast-iron ;  it  is  fixed  upon  the  top  of  a  wooden  pillar 
B,  solidly  supported  in  the  ground,  c  is  the  jaw  of  the  vice,  pressed  by  a  square- 
headed  screw  against  the  mandrel  a. 

D  part  of  the  mandrel  comprehended  between  x  and  t,  formed  as  an  inclined  plane, 
so  as  to  preserve  an  interval  equal  to  the  diameter  of  the  rod  between  the  two 
surfaces  that  are  to  be  welded  together. 

E  rectangular  slots  (shears)  passing  through  the  centre  of  the  nut  of  the  mandrel,  in 
which  each  of  the  pins  f  may  be  freely  slidden. 

G  horizontal  lever  of  wrought-iron  six  feet  long.  It  carries  at  h  a  pulley  or  friction- 
roller  of  steel,  whose  position  may  be  altered  according  to  the  diameter  of  the  links. 
It  is  obvious  that  as  many  mandrels  are  required  as  there  are  sizes  and  shapes  of  links. 

The  piece  of  iron  intended  to  form  a  link  being  cut,  is  carried,  while  red-hot,  to  the 
bending  machine,  where  it  is  seized  with  the  jaw  of  the  vice  c,  by  one  of  its  ends,  the 
slant  of  the  cut  being  turned  upwards ;  this  piece  of  iron  has  now  the  horizontal  direc- 
tion m  n  ;  on  pushing  the  lever  g  in  the  line  of  the  arrow,  the  roller  n  will  force  mnto 
be  applied  successively  in  the  elliptic  groove  of  the  mandrel :  thus  finally  the  two  faces 
that  are  to  be  welded  together  will  be  placed  right  opposite  each  other. 

The  length  of  the  small  diameter  of  the  ellipse  ought  to  exceed  by  a  little  the  length 
of  the  stay-piece,  to  allow  of  this  being  readi  y  introduced.  Tlie  difference  between 
the  points  f,  e,  is  equal  to  the  difference  of  the  radii  vectores  of  the  ellipse.  Hence  it 
will  be  always  easy  to  find  the  eccentricity  of  the  ellipse. 

JPlg.  290  is  a  lever  press  for  squeezing  the  links  upon  their  stays,  after  the  links  are 


welded.  This  machine  consists  of  a  strong  cast-iron  piece  a,  in  the  form  of  a  square, 
of  which  one  of  the  branches  is  laid  horizontally,  and  fixed  to  a  solid  bed  by  means  of 
bolts ;  the  other  branch,  composed  of  two  cheeks,  leaving  between  them  a  space  of  two 


CABLE. 


801 


incnes,  stands  upright.  These  two  cheeks  are  united  at  top,  and  on  the  back  of  their 
plane  by  a  cross  piece  b.  c,  a  rectangular  staple,  placed  to  the  right  and  led  of  the  cheeki 
through  which  is  passed  the  mandrel  d,  which  represents  and  keeps  the  place  of  the  fol- 
lowing link.  E,  is  a  press  lever,  6  feet  long,  f,  clamp  and  counterclamp,  between  which 
the  link  is  pressed  at  the  moment  when  the  stay  is  properly  placed.  There  are  other 
clamps,  as  well  as  staples  c,  for  changing  with  each  changed  dimension  of  links. 

The  links  bent,  as  we  have  seen,  are  carried  to  the  forge  hearth  to  be  welded,  and  to  re- 
ceive their  stay ;  two  operations  performed  at  one  heatmg.  Whenever  the  welding  is 
finished,  while  the  iron  is  still  red-hot,  the  link  is  placed  upright  between  the  clamps 
r;  then  a  Workman  introduces  into  the  staple  the  mandrel  d,  and  now  applies  the  stay 
with  a  pair  of  tongs  or  pincers,  while  another  workman  strikes  down  the  lever  e  forcibly 
upon  It.  This  mechanical  compression  first  of  all  joins  perfectly  the  sides  of  the  link 
against  the  concave  ends  of  the  stay,  and  afterwards  the  retraction  of  the  iron  on  cooline 
mcreases  still  more  this  compression. 

If  each  link  be  made  with  the  same  care,  the  cable  must  be  sound  throughout.  It 
IS  not  delivered  for  use,  however,  till  it  be  proved  by  the  hydrauhc  press,  ai  a  draw-bench 
made  on  purpose.  The  press  is  a  horizontal  one,  having  the  axis  of  its  ram  in  the 
middle  line  of  the  draw-bench,  which  is  about  60  feet  long,  and  is  secured  to  the  body  of 
the  press  by  strong  bolts. 

The  portion  of  chain  under  trial,  being  attached  at  the  one  end  to  the  end  of  the  ram 
of  the  press,  and  at  the  other  to  a  cross-bar  at  the  extremity  of  the  draw-bench,  two 
men  put  the  press  in  action,  by  turning  the  winch,  which  works  by  a  triple  crank  three 
forcing  pumps  alternately;  the  action  being  equalized  by  means  of  a  heavy  fly-wheeL 
As  long  as  the  resistance  does  not  exceed  the  force  of  two  men,  the  whole  three  pumps 
are  kept  in  play.  Aflter  a  while  one  pump  is  thrown  out  of  gear  and  next  another, 
only  one  being  worked  towards  the  conclusion.  The  velocity  of  the  ram  being  relaided 
first  one  thurd  and  next  two  thu-ds,  gives  the  men  a  proportional  mcrease  of  mechanical 
power. 

The  strength  of  two  average  men  thus  applied  being  computed,  enables  us  to  know  at 
every  instant  the  resistance  opposed  by  the  chain  to  the  pressure  of  the  ram.  The  strain 
usually  applied  to  the  stronger  cables  is  about  500  tons. 

The  side  beams  of  the  draw-bench  are  of  cast-iron,  6  inches  in  diameter ;  the  dif- 
ferent pieces  composing  it  are  adjusted  to  each  other  endwise  by  turned  joints.  Props 
also  of  cast-iron  support  the  beams  two  feet  asunder,  and  at  the  height  of  30  inches 
above  the  ground.  The  space  between  them  is  filled  with  an  oak  plank  on  which  th« 
trial  chain  is  laid. 

btrengtn  of  iron  cables  compared  to  hemp  cables : 


Iron  Cables. 
Diameter  of  Iron  Rod. 

Hemp  Cables. 
Circumference  of  Rope. 

Resistance. 

IncJus. 

Inc?ies. 

Tons. 

0| 

9 

12 

1 

10 

18 

1* 

11 

26 

li 

12 

32 

1 5 

13 

35 

14  to  15 

88 

u 

16 

44 

If 

17 

62 

li 

18 

60 

ll 

20 

70 

2 

22  to  24 

80 

It  would  be  imprudent  to  put  hemp  cables  to  severer  strains  than  those  indicated  in 
the  preceding  table,  drawn  up  from  Brunton's  experiments;  but  the  iron  cables  of  the 
above  sizes  wiU  support  a  double  stram  without  breaking.  The)  ought  never  in  com- 
mon  cases,  however,  to  be  exposed  to  a  greater  stress.  A  cable  destmed  for  ships  of  a 
certain  tonnage,  should  not  be  employed  m  those  of  greater  burden.  Thus  treated  it 
may  be  always  trusted  to  do  its  duty,  and  will  last  longer  than  the  ship  to  which  it  be- 
longs. A  considerable  part  of  this  decided  superiority  which  iron  cables  have  over  hemp 
ones,  is  undoubtedly  due  to  the  admirable  form  contrived  by  Brunton.  Repeated 
experunents  have  proved  that  his  cables  possess  double  the  strength  of  the  iron  rods 

IvLT    '^    •  ^?  ^'^  made -a  fact  which  demonstrates  that  no  stronger  fonn  can  be 
aevised  or  is  m  fact  possible.  ° 

\J!^^A-  ^i'^°''i'*  ^^^^h\e  qualities  of  iron  cables  is  their  resisting  lateral  as  weU  as 
lo^tudmal  strains,  as  explained  under  Jigs.  219  and  221. 

Vessels  furnished  with  such  cables  have  been  saved  by  them  from  the  most  imminent 


3oa 


CADMIUM. 


CALCroM. 


303 


peril.  The  Henry,  sent  out  with  army  stores  during  the  peninsular  war,  was  caught 
on  the  northern  coast  of  Spain  in  a  furious  storm.  She  run  for  shelter  into  the  Bay  of 
Biscay  among  the  rocks,  where  she  was  exposed  for  three  days  to  the  hurricane.  She 
possessed  fortunately  one  of  Brunton's  70  fathom  chain  cables,  which  held  good  all  the 
time,  but  it  was  found  afterwards  to  have  had  the  links  of  its  lower  portion  polished 
bright  by  attrition  against  the  rocky  bottom.  A  hemp  cable  would  have  been  speedily 
torn  to  pieces  in  such  a  predicament. 

In  the  contracts  of  the  Admiralty  for  chain  cables  for  the  British  navy,  it  is  stipulated 
/hat  "  the  iron  shall  have  been  manufactured  in  the  best  manner  from  pig  iron,  smelted 
from  iron-stone  only,  and  selected  of  the  best  quality  for  the  purpose,  and  shall  not  have 
received,  in  any  process  whatever  subsequent  to  the  smelting,  the  admixture  of  either  the 
cinder  or  oxydes  produced  in  the  manufacture  of  iron  ;  and  shall  also  have  been  puddled 
in  the  best  manner  upon  iron  bottoms,  and  at  least  three  times  sufficiently  drawn  out  at 
three  distinct  welding  heats,  and  at  least  twice  properly  fagoted." 

The  following  is  a  table  of  the  breaking  proof  of  chain  cables,  and  of  the  iron  for  the 
purpose  of  making  them,  also  of  the  proofs  required  by  her  majesty's  navy  for  chains. 


Size  of  Bolt. 

Proof  of  Bolt. 

Proof  of  Chain. 

Navy  Proof  of  Chain. 

Inches. 

TOTU.          Cwt. 

Tons.        Ciot. 

Tons. 

k 

5          7 

8          11 

4| 

1 

8          7 

13          4 

12          1 

19          6 

10| 

i 

16          4 

26          6 

13| 

21          8 

34          5 

18 

1| 

27          2 

48        15 

22f 

1| 

33        10 

53         11 

281 

]| 

40        10 

65          0 

34 

1 

48           4 

77          0 

40| 

1 

56        11 

90        10 

47| 

1 

65        12 

105          0 

5H 

If 

75          6 

120        10 

63i 

2 

85        14 

137          0 

72 

21 

96         15 

1.55          0 

81J 

In  Brunton's  cable  the  matter  in  the  link  is  thrown  very  much  into  one  plane ;  th« 
link  being  of  an  oval  form,  and  provided  with  a  stay.  As  there  are  emergencies  in  which 
the  cable  must  be  severed,  this  is  accomplished  in  those  of  iron  by  means  of  a  bolt  and 
sheckle  (shackle),  at  every  fathom  or  two  fathoms  ;  so  that  by  striking  xjut  this  bolt  or 
pin,  this  cable  is  parted  with  more  ease  than  a  hempen  one  can  be  cut. 

CACAO,  BUTTER  OF.     See  Cocoa,  and  Oils,  Unctuous. 

CADMIUM  is  a  metal  discovered  about  the  beginning  of  the  year  1818.  It  occurs 
chiefly  in  Silesia  in  several  ores  of  zinc ;  and  may  be  readily  recognised  by  means  of 
the  blowpipe ;  for  at  the  first  impression  of  the  reducing  or  smoky  part  of  the  flame,  the 
ores  containing  cadmium  stain  the  charcoal  all  round  them  with  a  reddish  yellow  circle 
of  oxyde  of  cadmium.  The  Silesian  native  oxyde  of  zinc  contains  from  1 J  to  11  per 
cent,  of  cadmium. 

The  cadmium  may  be  extracted  by  dissolving  the  ore  in  sulphuric  acid,  leaving 
the  solution  acidulous,  and  diluting  it  with  water,  then  transmitting  through  it  a 
stream  of  sulphureted  hydrogen,  till  the  yellow  precipitate  ceases  to  fall.  This 
powder,  which  is  sulphuret  of  cadmium,  is  to  be  dissolved  in  concentrated  muri- 
atic acid,  the  excess  of  which  is  to  be  expelled  by  evaporation ;  and  the  muriatic 
salt  being  dissolved  in  water,  carbonate  of  ammonia  is  to  be  added  in  excess,  whereby 
the  cadmium  separates  as  a  carbonate,  while  the  small  portion  of  adhering  copper 
or  zinc  is  retained  in  solution  by  the  ammonia.  Herapath  has  shown,  that  in  distilling 
zinc  per  descensum  (see  Zinc),  the  first  portions  of  gaseous  metal  which  are  disengaged 
burn  with  a  brown  flame  and  deposite  the  brown  oxyde  of  cadmium. 

Cadmium  has  the  color  and  lustre  of  tin,  and  is  susceptible  of  a  fine  i>olish.  Its 
fracture  is  fibrous ;  it  crystallizes  readily  in  regular  octahedrons,  and  when  it  suddenly 
solidifies,  its  surface  gets  covered  with  fine  mossy  vegetations.  It  is  soft,  easily  bent, 
filed,  and  cut,  soils  like  lead  any  surface  rubbed  with  it.  It  is  harder  and  more  tena- 
cious than  tin,  and  emits  a  creaking  sound  when  bent,  like  that  metal.  It  is  very  ductile, 
and  may  be  drawn  out  into  fine  wire,  and  hammered  into  thin  leaves  without 
cracking  at  the  edges.  Its  specific  gravity,  after  being  merely  melted,  is  8*604 ;  and 
8-6944  after  it  has  been  hammered.  It  is  very  fusible,  melting  at  a  heat  much  under 
redness  ;  indeed,  at  a  temperature  little  exceeding  that  of  boiling  mercury,  it  boils  and 
distils  over  in  drops.    Its  vapors  have  no  smell.    It  is  but  slightly  altered  by  exposure 


to  air.  "When  heated  in  the  atmosphere,  it  readily  takes  fire,  and  burns  with  a  brownish 
yellow  smoke  which  is  destitute  of  smell  In  strong  acids  it  dissolves  with  disengage- 
ment of  hydrogen,  and  forms  colourless  solutions.  Chromate  of  potash  causes  no  pre- 
cipitate in  them,  unless  zinc  or  lead  be  present. 

There  is  only  one  oxide  of  cadmium,  the  brown  above  mentioned.  Its  specific  gra- 
vity is  8*183.  It  is  neither  fusible  nor  volatile  at  a  very  high  temperature.  When  in 
the  state  of  a  hydrate  it  is  white.  The  oxide  of  cadmium  consists  of  87  "45  parts  of 
metal,  and  12'55  oxygen  in  100  parts.  Berzelius  states  its  atomic  weight  to  be  55*833 
to  hydrogen  1  '000.  Its  sulphuret  has  a  fine  orange  yellow  colour,  and  would  form  a 
beautiful  pigment,  could  the  metal  be  found  in  sufficient  quantity  for  the  purposes  of 
art    The  sulphate  is  applied  to  the  eyes  by  surgeons  for  removing  specks  of  the  cornea. 

CAFFEINE.  A  chemical  principle  discovered  in  cofi'ee,  remarkable  for  containing 
much  azote.     See  Coffee. 

According  to  Robiquet  the  proportion  of  caffeine  in  1000  of  coffee  is  as  follows ; 

Martinique  6*4,  Alexandrian  4*4,  Java  4*4,  Mocha  4,  Cayenne  3*8,  St.  Domingo  3*2. 
It  is  probable  that  0*64  per  cent,  is  an  ordinary  proportion.  According  to  Liebig,  the 
proportions  are  per  lb.,  Martinique  32  gr.,  Alexandrian  22,  Java  22,  Mocha  20, 
Cayenne  19,  St  Domingo  16.  H.  J.  Vereman  of  Lubeck  mixes  10  lbs.  of  bruised  raw 
coffee  with  2  of  caustic  lime,  made  previously  into  hydrate ;  treats  the  mixture  in  a 
displacement  apparatus  with  alcohol  of  80°  till  the  fluid  which  passes  through  no 
longer  furnishes  evidence  of  the  presence  of  caffeine.  The  coffee  is  then  roughly  ground 
and  brought  nearly  to  the  state  of  a  powder,  and  the  refuse  of  the  once  digested  mix- 
ture from  the  displacement  apparatus,  dried  and  ground  again,  and  mixed  with  hydrate 
of  lime,  is  once  more  macerated.  The  grinding  is  more  easily  effected  after  the  coffee 
has  been  subjected  to  the  operation  of  alcohol,  having  lost  its  horny  quality,  and  the 
caffeine  is  thus  more  certainly  extracted.  The  clear  alcoholic  liquid  thus  obtained  is  then 
to  be  distilled,  and  the  refuse  in  the  retort  to  be  washed  with  warm  water,  to  separate 
the  oil.  The  fluid  is  now  evaporated  into  a  crystalline  mass,  filtered  and  expressed. 
The  impure  caffeine  is  freed  from  oil  by  pressure  between  folds  of  blotting  paper, 
purified  by  solution  in  water  with  animal  charcoal,  and  is  thus  obtained  in  shining 
white  silky  crystals.  In  general  not  more  than  3  drams  were  procured  from  5  pounds 
of  coffee,  from  10  pounds  7  drams,  and  from  100  pounds  the  largest  quantity,  viz.  6 
ounces  and  4  scruples  of  caffeine ;  a  proof  that  a  large  quantity  must  be  operated  upon, 
if  in  a  quantitative  respect  a  satisfactory  result  is  to  be  obtained.  Thus  it  is  seen  that 
good  Brazilian  coffee  contains  0*57  per  cent,  of  caffeine.  At  the  same  time  it  may  be 
observed  that  it  contains  about  10  per  cent,  of  a  green  liquid  oil,  and  2  per  cent,  of  a 
yellow  solid  fat. 

CAJEPUT  OIL  is  obtained  from  the  leaves  of  the  tree  called  Melaleuca  Leuca- 
dendron  by  Linnajus,  which  grows  upon  the  mountains  of  Amboyna,  and  in  other  of 
the  Molucca  islands.  It  is  procured  by  distillation  of  the  dried  leaves  along  with 
water,  is  prepared  in  great  quantities  m  the  island  of  Banda,  and  sent  to  Holland 
in  copper  flasks.  Hence  as  it  comes  to  us,  it  has  a  green  colour.  It  is  very  limpid, 
lighter  than  water,  of  a  strong  smell  resembling  camphor,  and  pungent  taste  like 
cardamoms.  When  rectified  the  copper  remains  in  the  retort,  and  the  oil  comes  over 
colourless.     It  is  used  in  medicine  as  a  stimulant.     See  Oils,  Etuereous. 

CALAMANCO.  A  sort  of  woollen  stuff  of  a  shining  appearance,  chequered  in 
the  warp,  so  that  the  checks  are  seen  only  upon  one  side. 

CALAMINE.     A  native  carbonate  of  zinc.     See  Zinc. 

CALCAREOUS  EARTH.  {Terre  calcaire,  Fr. ;  Xalkerde,  Germ.)  Commonly 
denotes  lime,  in  any  form ;  but,  properly  speaking,  it  is  pure  lime. 

CALCAREOUS  SPAR.     Crystallized  native  carbonate  of  lime. 

CALCEDONY.  A  hard  mineral  of  the  siliceous  family,  often  cut  into  seals.  Under 
it  may  be  grouped  common  calcedony,  heliotrope,  chrysoprase,  plasma,  onyx,  sardonyx, 
and  sard. 

CALCHANTUM.     The  ancient  name  of  native  copperas  or  sulphate  of  iron. 

CALCINATION,  is  the  chemical  process  of  subjecting  metallic  bodies  to  heat  with 
access  of  air,  whereby  they  are  converted  into  a  pulverulent  matter,  somewhat  like 
lime  in  appearance,  called  calx  in  Latin.  The  term  calcination,  however,  is  now  used 
when  any  substance  whatever  is  exposed  to  a  roasting  heat. 

CALCIUM.    The  metallic  basis  of  lime.    See  Lime. 

The  atomic  weight  of  this  element  being  an  important  point,  both  as  to  pure 
chemistry  and  the  chemical  arts,  has  been  the  subject  of  innumerable  researches. 
Very  lately  Berzelius,  in  the  Annalen  der  Chemie  und  Phamiacie,  xlvl  p.  241.,  has 
collated  the  most  recent  results  of  the  analysis  of  other  philosophers  with  his  own  ;  and 
while  Dumas,  Marchand,  and  Erdmann  estimate  the  weight  at  20,  that  of  hjdrogen  =.  1, 
or  250  oxygen  =  100,  he  finds  it  ought  to  be,  as  compared  with  the  latter,  2519 ;  and 
to  the  former,  20,152. 


304 


CALENDER. 


CALENDER. 


305 


CALC-SINTER.  The  incrastations  of  carbonate  of  lime  upon  the  ground,  or  the 
pendulous  conical  pieces  called  stalactites,  attached  to  the  roofs  of  caverns,  ait  so  called. 

CALC-TUFF.  A  semi-hard,  irregular  deposite  of  carbonate  of  lime,  formed  from 
the  waters  of  calcareous  springs. 

CALCULUS.  The  stony-looking  morbid  concretion,  occasionally  formed  in  the 
bladder  of  urine,  gall-bladder,  cystic  duct,  kidneys,  and  other  parts  of  living  animals. 
Its  examination  belongs  to  medical  chemistry. 

CALENDER  (Calandre,  Fr. ;  Kalander,  Germ.),  a  word  derived  from  the  Greek 
kalindros  ( cylinder),  is  the  name  of  a  machine,  consisting  of  two  or  more  cylinders,  revolving 
so  nearly  in  contact  with  .each  other  that  cloth  passed  through  between  them  is  smoothed, 
and  even  glazed,  by  their  powerful  pressure.  It  is  employed  either  to  finish  goods  for  the 
market,  or  to  prepare  cotton  and  linen  webs  for  the  calico-printer,  by  rendering  their  sur- 
faces level,  compact,  and  uniform.  This  condensation  and  polish,  or  satinage,  as  the  French 
call  it,  difler  in  degree  according  to  the  object  in  view,  and  may  be  arranged  into  three 
distinct  series.  1.  For  goods  which  are  to  receive  the  first  impression  by  the  block, 
a  very  strong  pressure  is  required ;  for,  upon  the  uniformity  of  the  polish,  the  neatness 
and  regularity  of  the  printing,  and  the  correspondence  of  its  members,  depend.  In 
many  establishments  the  calico  is  passed  twice  through  the  calender  before  being  sent 
to  the  tables.  2.  The  pieces  already  dyed  up  at  the  madder  bath,  or  otherwise,  and 
which  remain  to  be  filled  in  with  other  colors,  or  grounded-in,  as  it  is  technically  styled, 
must  receive  a  much  less  considerable  gloss.  This  is  a  principle  everywhere  admitted 
and  acted  upon,  because  the  outline  of  the  figured  design  being  deranged  by  the 
washing,  and  sometimes  in  consequence  of  the  peculiar  texture  of  the  cloth,  the  printer, 
in  order  to  apply  his  grounding  blocks  properly,  and  to  fit  them  to  the  contours  of  the 
figures  already  impressed,  is  obliged  to  stretch  the  piece  sometimes  in  the  direction  of 
the  warp,  and  sometimes  of  the  weft,  which  would  be  impossible  if  they  had  been  hard 
glazed  by  the  calender.  3.  The  degree  of  glazing  given  to  finished  goods  depends  upon 
the  taste  of  purchasers,  and  the  nature  of  the  article ;  but  it  is,  in  general,  much  less 
than  for  the  first  course  of  block-printing. 

The  most  complete  calender  probably  in  existence  is  that  used  by  some  of  the 
eminent  calico-printers  of  Alsace,  as  contrived  by  M.  Charles  Dollfus,  and  constructed 
by  MM.  Witz,  Blech,  and  Co.  1.  It  passes  two  pieces  at  once,  and  thus  does  double  the 
work  of  any  ordinary  machine.  2.  It  supersedes  the  necessity  of  having  a  workman  to 
fold  up  the  goods,  as  they  emerge  from  the  calender,  with  the  aid  of  a  self-acting  folder. 
3.  It  receives,  at  pleasure,  the  finished  pieces  upon  a  roller,  instead  of  laying  them  in 
folds ;  and,  by  a  very  simple  arrangement,  it  hinders  the  hands  of  the  workmen  from 
being  caught  by  the  rollers. 

Calenders,  in  consequence  of  the  irregular  demand  for  foreign  orders  and  shipments, 
are  worked  very  irregularly,  being  sometimes  overloaded  with  duty,  and  at  others  alto- 
gether unemployed.  A  machine  which  can,  when  required,  turn  out  a  double  quantity 
of  goods,  must,  therefore,  be  a  desirable  possession.  For  the  first  course  of  the  printers, 
where  high  calendering  is  necessary,  the  goods  are  usually  passed  twice  through  be- 
tween two  paper  cylinders,  to  give  that  equality  of  surface  which  could  not  be  obtained  by 
one  passage,  however  strong  the  pressure ;  and  therefore  the  simplification  of  this  calen- 
der will  prove  no  economy.  Besides,  in  order  to  increase  the  pressure  to  the  requisite  de- 
gree, the  cylinders  would  need  to  be  made  bulging  at  their  middle  part,  and  with  such 
cylinders  common  smoothing  could  not  be  given ;  for  the  pieces  would  be  glazed  in  the 
central  line,  and  rough  towards  the  edges.  For  pieces  already  printed  in  part,  and  re- 
quiring only  to  be  grounded-in  for  other  colors,  the  system  of  double  effect  has  fewer  ob- 
jections, as  a  single  passage  through  the  excellent  calender  described  under  Bleaching, 
page  140,  is  found  to  answer  very  well. 

The  most  remarkable  feature  of  M.  Dollfus's  machine  is  its  being  managed  by  a  single 
workman.  5?x  or  eight  pieces  are  coiled  upon  the  feed-roller,  and  they  are  neither  pasted 
nor  stitched  together,  but  the  ends  are  merely  overlapped  half  a  yard  or  so.  The 
workman  is  careful  not  to  enter  the  second  piece  till  one  third  or  one  half  of  the  first 
one  has  passed  through  on  the  other  side,  to  prevent  his  being  engrossed  with  two  ends 
at  a  time.  He  must,  no  doubt,  go  sometimes  to  the  one  side,  and  sometimes  to  the 
other  of  the  machine,  to  see  that  no  folds  or  creases  occur,  and  to  be  ready  for  supplying 
a  fresh  piece  as  the  preceding  one  has  gone  through.  The  mechanism  of  the  folder  in 
the  Alsace  machine  is  truly  ingenious :  it  performs  extremely  well,  really  saves  the 
attendance  of  an  extra  workman,  and  is  worthy  the  attention  of  manufacturers  intent 
upon  economizing  hand  labor.  The  lapping-roller  works  by  friction,  and  does  its  doty 
fully  better  than  similar  machines  guided  by  the  hand. 

The  numerous  accidents  which  have  happened  to  the  hands  of  workmen  engaged  in 
calenders  should  direct  the  attention  towards  its  effective  contrivance  for  preventing  such 
misfortunes.  These  various  improvements  in  the  Alsace  machine  may  be  easily  adapted 
*o  the  ordinary  calenders  of  almost  every  construction. 


I      \ 


a 


The  folder  is  a  kind  of  cage,  in  the  shape  of  an  inverted  pyramid,  shut  on  the  tour 
sides  and  open  at  top  and  bottom ;  the  top  orifice  is  about  five  inches,  the  bottom  one 
an  inch  and  a  half;  the  front  and  the  back,  which  are  about  four  feet  broad,  are  made  of 
tin-plate  or  smooth  pasteboard,  and  the  two  sides  are  made  of  strong  sheet-iron  ;  the  whole 
oeing  bolted  together  by  small  bars  of  iron.  Upon  the  sheet-iron  of  the  sides,  iron  up- 
•-ights  are  fixed,  perforated  with  holes,  through  which  the  whole  cage  is  supported  freely 
bv  njeans  of  studs  that  enter  into  them.  One  of  the  uprights  is  longer  than  the  other, 
and  bears  a  slot  with  a  small  knob,  which,  by  means  of  the  iron  piece,  joins  the  guide  to 
the  crank  of  the  cylinder,  and  thereby  communicates  to  the  cage  a  seesaw  movement ; 
at  the  bottom  extremity  of  the  great  upright,  there  is  a  piece  of  iron  in  the  shape  of  an 
anchor,  which  may  be  raised,  or  lowered,  or  made  fast,  by  screws. 

At  the  ends  of  this  anchor  are  friction-rollers,  which  may  be  drawn  out  or  pushed 
back  and  fixed  by  screws;  these  rollers  lift  alternately  two  levers  made  of  wood,  and  fixed 
to  a  wooden  shaft. 

The  paws  are  also  made  of  wood :  they  serve  to  lay  down  alternately  the  plies  of  the 
cloth  which  passes  upon  the  cage,  and  is  folded  zigzag  upon  the  floor,  or  upon  a  board 
set  below  the  cage ;  a  motion  imparted  by  the  seesaw  motion  of  the  cage  itself.  See 
Stretching  Machine. 

To  protect  the  fingers  of  the  workmen,  above  the  small  plate  of  the  spreading-board 
or  bar,  there  is  another  bar,  which  forms  with  the  former  an  angle  of  about  75" ;  they 
come  sufficiently  near  together  for  the  opening  at  the  summit  of  the  angle  to  allow  the 
cloth  to  pass  through,  but  not  the  fingers.  See  Bulletin  de  la  Sociele  IndusiritUe  de 
Mulhauseriy  No.  18. 

I  shall  now  describe,  more  minutely,  the  structure  of  the  powerful  but  less  complicated 
calender  mechanisms  employed  in  the  British  manufactories. 

A  front  elevation  of  a  four-rollered  calender  (five  rollers  are  often  introduced)  for  gla- 
ring goods  is  given  in^g.  293.  d  I  are  two  pasteboard  or  paper  cylinders,  each  20  inched 
293  291-^ 


m  diameter,  whose  structure  will  be  presently  described  :  /  is  a  cast-iron  cylinder  turned 
perfectly  smooth  (its  fellow  is  often  placed  between  e  and  d) :  it  is  eight  inches  in  diame- 
ter outside,  four  inches  inside,  with  two  inches  thickness  of  metal,  e  is  another  paste- 
board cylinder,  fourteen  inches  in  diameter:  the  strong  cast-iron  frame  contains  the  bush- 
es in  which  the  journals  of  the  rollers  turn,  op,  is  one  of  the  pair  of  levers  for  commu- 
nicating a  graduated  pressure  according  to  the  quality  of  the  goods.  Figs.  292,  293,  are  end 
views  of  the  same  machine  to  show  the  working  gear.  The  wheel  s,  on  the  end  of  the 
upper  iron  cylinder,  is  ten  inches  in  diameter;  that  on  the  end  of  the  fellow  iron  cylinder 
below  (when  it  is  present)  is  thirteen  inches ;  both  are  connected  by  the  larger  carrier 
wheel  /.  The  lower  wheel  u  is  one  third  larger  than  the  upper  wheel,  and  therefore 
receives  from  the  carrier  wheel  /,  a  proportionally  slower  motion,  which  it  imparts  to  the 
central  pasteboard  roller  «,  lying  upon  it,  causing  it  to  move  one  third  more  slowly  than 
the  upper  pasteboard  roller.  Thus  a  sort  of  sliding  motion  is  produced,  which,  by  rubbing 
Iheir  surfaces,  glazes  the  goods. 
The  iron  rollers  are  made  hollow  for  the  purpose  of  admitting  either  a  hot  roller  ol 


306 


CALENDER. 


CALICO-PRINTING. 


307 


iron,  or  steam  when  hot  calendering  is  required.  The  other  cylinders  used  formerly  to  be 
made  of  wood,  but  it  was  liable  to  many  defects.  The  advantage  of  the  paper  roller 
consists  in  its  being  devoid  of  any  tendency  to  split,  crack,  or  warp,  especially  when 
exposed  to  a  considerable  heat  from  the  contact  and  pressure  of  the  hot  iron  rollers. 
The  paper,  moreover,  takes  a  vastly  finer  polish,  and,  being  of  an  elastic  nature,  presses 
into  every  pore  of  the  cloth,  and  smooths  its  surface  more  effectually  than  any  wooden 
cylinder,  however  truly  turned,  could  possibly  do. 

The  paper  cylinder  is  constructed  as  foUows :— The  axis  of  the  cylinder  is  a  stron«» 
square  bar  of  the  best  wrought  iron,  cut  to  the  proper  length.    Upon  this  bar  a  strong 
round  plate  of  cast  iron  is  first  put,  somewhat  less  in  diameter  than  the  cylinder  when 
finished.     A  quantity  of  thick  stout  pasteboard  is  then  procured,  and  cut  into  round 
pieces  an  inch  larger  in  diameter  than  the  iron  plate.     In  the  centre  of  the  plates,  and 
of  every  piece  of  the  pasteboard,  a  square  hole  must  be  cut  to  receive  the  axis;  and,  the 
circle  being  divided  into  six  equal  parts,  a  hole  must  also  be  cut  at  each  of  the  divisions 
an  inch  or  two  within  the  rim.     These  pieces  of  pasteboard  being  successively  put 
upon  the  axis,  a  long  bolt  of  malleable  iron,  with  a  head  at  one  end,  and  screwed  at  the 
other,  is  also  introduced  through  each  of  the  holes  near  the  rim;  and  this  is  continued 
ttntil  a  suflicient  number  of  pasteboards  are  thus  placed  to  form  a  cylinder  of  the 
length  required,  proper  allowance  being  made  for  the  compression  which  the  pasteboard 
IS  afterwards  to  undergo.    Another  round  plate  is  then  applied,  and,  nuts  being  pat 
upon  the  screws,  the  whole  are  screwed  tight,  and  a  cylinder  formed.    This  cylinder  is 
now  to  be  placed  in  a  stove,  exposed  to  a  strong  heat,  and  must  be  kept  there  for  at  least 
several  days ;  and,  as  the  pasteboard  shrinks  by  exposure  to  the  heat,  the  screws  must 
be  frequently  tightened  until  the  whole  mass  has  been  compressed  as  much  as  possible 
When  the  cylinder  is  thus  brought  to  a  suflicient  degree  of  density,  it  is  removed  from 
the  stove ;  and,  when  allowed  to  cool,  the  pasteboard  forms  a  substance  almost  incon- 
ceivably  dense  and  hard.     Nothing  now  remains  but  to  turn  the  cylinder ;  and  this  is  an 
operation  of  no  slight  labor  and  patience.    The  motion  in  turning  must  be  slow,  not 
exceeding  about  forty  revolutions  in  a  minute ;  the  substance  being  now  so  hard  and 
tough  that  tools  of  a  very  small  size  must  be  used  to  cut,  or  rather  scrape  it,  until  it  is 
true.     Three  men  are  generally  employed   for  the  turnin?,  even  when  the  motion  of 
the  cylinder  is  effected  by  mechanical  power,  two  being  necessarj'  to  sharpen  tools  for 
the  third,  who  turns,  as  quickly  as  he  blunts  them. 

Let  us  suppose  it  to  be  a  five-rollered  machine:  when  a  person  stands  in  front  of 
the  calender,  the  cloth  coming  from  behind  above  the  uppermost  cylinder  1,  passes  be- 
tween 1  and  2 :  proceeding  behind  2,  it  again  comes  to  the  front  between  2  and  3  • 
between  3  and  4  it  is  once  more  carried  behind,  and,  lastly,  brought  in  front  between 
4  and  5,  where  it  is  received,  and  smoothly  folded  on  a  clean  board,  or  in  a  box  by  a 
person  placed  there  for  the  purpose.  In  folding  the  cloth  at  this  time,  care  roust  be 
taken  that  it  may  be  loosely  done,  so  that  no  mark  may  appear  until  it  be  again  foWed 
in  the  precise  length  and  form  into  which  the  piece  is  to  be  made  up.  The  foldin*'  may 
be  done  either  by  two  persons  or  by  one,  with  the  aid  of  two  sharp  polished  spikes 
placed  at  a  proper  distance,  to  ascertain  the  length  of  the  fold,  and  to  make  the  whole 
equal.  When  folded  into  lengths,  it  is  again  folded  across  upon  a  smooth  clean  table 
according  to  the  shape  intended,  which  varies  with  the  different  kinds  of  goods,  or  the 
particular  market  for  which  the  goods  are  designed. 

When  the  pieces  have  received  the  proper  fold,  the  last  operation  previous  to  packing 
them  IS  the  pressing.  This  is  commonly  performed  by  placing  a  certain  number  of  pieces, 
divided  by  thin  smooth  boards  of  wood,  in  a  common  screw  press,  similar  to  those  used 
by  printers  for  taking  out  the  impression  left  by  the  types  in  the  printing-press.  Be- 
sides the  wooden  boards,  a  piece  of  glazed  pasteboard  is  placed  above  and  below  every 
piece  of  cloth,  that  the  outer  folds  may  be  as  smooth  and  glossy  as  possible.  The 
operation  of  the  common  screw  press  being  found  tedious  and  laborious,  the  hydrau- 
lic press  is  now  m  all  well-mounted  establishments  had  recourse  to.  See  Hydrauuc 
Press. 

No  improvements  that  have  taken  place  in  calendering  can  exceed  the  power  and  fa- 
cility of  the  water  press :  one  of  these  presses  mt^y  be  worked  by  two  men,  who  can 
with  great  ease  produce  a  pressure  of  400  tons ;  but,  in  considerable  establisliments,  the 
presses  are  worked  by  power.    See  Bandanna  . 

The  appearance  and  finish  of  the  goods,  in  consequence  of  such  an  immense  wei«»ht 
acting  on  them,  are  materially  improved.  ° 

The  press  is  also  used  for  the  purpose  of  packing ;  whereby  the  bale  is  rendered  much 
more  compact  than  formerly.  It  is  commonly  roped,  &c.,  while  in  this  compressed 
state ;  the  dimensions  are  therefore  greatly  diminished  from  what  they  would  otherwise 
be  by  any  other  method.  For  instance,  the  same  quantity  of  goods  packed  in  a  bale 
are  from  one  third  to  one  half  less  bulky  than  if  they  were  packed  in  a  box  with  tht 
atmost  force  of  the  hands. 


Tor  lawns  and  muslins  of  a  light  texture,  the  operation  of  smoothing  rpc-.^ires  a  dil. 
ferent  process  in  some  respects  than  close  heavy  fabrics.  They  only  require  to  be  slightly 
smoothed  to  remove  any  marks  which  they  may  have  received  at  the  bleaching;  and  as 
fheir  beauty  depends  rather  on  their  transparency  than  their  closeness,  the  more  the  cy 
lyndrical  form  of  the  yarn  is  preserved  the  better.  They  are  therefore  put  through  a 
small  machine,  consisting  of  three  rollers  or  cylinders;  and  as  the  power  required  to 
move  this  is  small,  the  person  who  attends  it  generally  drives  it  by  a  small  winch ;  or 
the  same  effect  may  be  produced  by  passing  the  muslins  between  only  two  or  three  rollers 
of  the  above  calender,  lightly  loaded. 

In  the  thick  fabrics  of  cloth,  including  those  kinds  which  are  used  for  many  parts  ot 
household  furniture,  as  also  those  for  female  dress,  the  operation  of  glazing  is  used  both 
to  add  to  the  original  beauty  of  the  cloth,  and  to  render  it  more  impervious  to  dust  or 
smoke.  The  glazing  operation  is  performed  entirely  by  the  friction  of  any  smooth 
substance  upon  the  cloth ;  and,  to  render  the  gloss  brighter,  a  small  quantity  of  bleached 
wax  is  previously  rubbed  over  the  surface.  The  operation  of  glazing  by  the  common 
plan  is  very  laborious,  but  the  apparatus  is  of  the  most  simple  kind.  A  table  is  mounted 
with  a  thick  stout  cover  of  level  and  well-smoothed  wood,  forming  an  inclined  plane ; 
that  side  where  the  operator  stands  at  work  being  the  lowest.  The  table  is  generally 
placed  near  a  wall,  both  for  convenience  in  suspending  the  glazing  apparatus,  and  for 
the  sake  of  light.  A  long  piece  of  wood  is  suspended  in  a  groove  formed  between  two 
longitudinal  beams,  placed  parallel  to  the  wall,  and  fixed  to  it.  The  groove  resembles 
exactly  the  aperture  between  the  shears  of  a  common  turning  lathe.  The  lever,  of  which 
the  groove  may  be  supposed  to  be  the  centre  or  fulcrum,  is  faced  at  the  bottom  with  a 
semi-cylindrical  piece  of  finely  polished  flint,  which  gives  the  friction  to  the  cloth  stretched 
upon  the  table  below.  Above  the  flint  are  two  cross  handles,  of  which  the  operator 
lays  hold,  and  moves  them  backward  and  forward  with  his  hands,  keeping  the  flint  press- 
ing slightly  upon  the  cloth.  When  he  has  glazed  a  portion  equal  to  the  breadth  of  the 
flint,  he  moves  his  lever  between  the  shears  sidewise,  and  glazes  a  fresh  part :  thus  he 
proceeds  from  one  side  or  selvage  of  the  cloth  to  the  other ;  and  when  all  which  is  upon 
the  table  is  sufficiently  glazed,  he  draws  it  over,  and  exposes  a  new  portion  to  the  same 
operation.  To  preseive  the  cloth  at  a  proper  tension,  it  may  be  wound  smoothly  upon 
a  roller  or  beam,  which  being  set  so  as  to  revolve  upon  its  own  axis  behind  the  table, 
another  roller  to  receive  the  cloth  may  be  placed  before,  both  being  secured  by  a  catch, 
acting  in  a  ratchet  wheel.  Of  late  years,  however,  a  great  part  of  the  labor  employed 
in  glazin?  cloth  has  been  saved,  as  the  common  four  or  five  bowl  calender  has  been 
altered  to  fit  this  purpose  by  direct  pressure. 

As  a  matter  of  accommodation,  the  different  processes  of  packing,  cording  of  boxes, 
sheeting  of  trunks,  and,  in  general,  all  the  arrangements  preparatory  to  shipments,  and 
also  the  intimations  and  surveys  necessary  for  obtaining  drawbacks,  debentures,  or 
bounties,  according  to  the  excise  laws,  are  generally  conducted  at  the  calender  houses 
where  goods  are  finished.  Tliese  operations  sufficiently  account  for  the  general  meaning 
attached  to  the  word. 

CALICO-PRINTING  (Impression  d'Indiennes,  Fr. ;  Zeugdruckerei,  Germ.)  is  the 
art  of  impressing  cotton  cloth  with  topical  dyes  of  more  or  less  permanence.  Of  late 
years,  silk  and  woollen  fabrics  have  been  made  the  subjects  of  a  similar  style  of 
dyeing.  Linens  were  formerly  stained  with  various  colored  designs,  but  since  the 
modern  improvements  in  the  manufacture  of  cotton  cloth,  they  are  seldom  printed,  as 
they  are  both  dearer,  and  produce  less  beautiful  work,  because  flax  possesses  less  affinity 
than  cotton  for  coloring  matters. 

This  art  is  of  very  ancient  date  in  India,  and  takes  its  English  name  from  Calicut,  a 
district  where  it  has  been  practised  with  great  success  from  time  immemorial.  The 
Egyptians,  also,  appear  from  Pliny's  testimony  to  have  practised  at  a  remote  era  some  of 
the  most  refined  processes  of  topical  dyeing.  **  Robes  and  white  veils,"  says  he,  "arc 
painted  in  Egypt  in  a  wonderful  way.  They  are  first  imbued,  not  with  dyes,  but  with 
dye-absorbing  drugs,  by  which,  though  they  seem  to  be  unaltered,  yet,  when  immersed 
for  a  little  while  in  a  caldron  of  the  boiling  dye-liquor,  they  are  found  to  become 
painted.  Yet,  as  there  is  only  one  color  in  the  caldron,  it  is  marvellous  to  see  many 
colors  imparted  to  the  robe,  in  consequence  of  the  influence  of  the  excipient  drug.  Nor 
can  the  dye  be  washed  out.  A  caldron,  which  would  of  itself  merely  confuse  the  colors 
of  cloths  previously  dyed,  is  thus  made  to  impart  several  pigments  from  a  single  dye- 
stuff,  painting  as  it  tot/*."  The  last  expression,  ptrtgiYgtte  dum  coquit,  is  perfectly  graphic 
and  descriptive  of  calico-printing. 

The  cotton  chints  counterpanes  of  great  size,  called  paUampoors,  which  have  been 
manufactured  in  Madras  from  the  earliest  ages,  have  in  like  manner  peculiar  dye-absorb- 
ing drugs  applied  to  them  with  the  pencil,  as  also  wax,  to  protect  certain  parts  of  the 
surface  from  the  action  of  the  dye,  and  are  afterwards  immersed  in  a  staining  liquor,  which, 
when  wax  is  applied,  is  usually  the  cold  indigo-vat,  but  without  the  wax  is  a  hot  liquor 
similar  to  the  Egyptian.    M.  Koechlin  Roder,  of  JMulhouse,  brought  home  lately  from 


308 


CALICO-PRINTING. 


CALICO-PRINTING. 


309 


India  a  rich  collection  of  cloths  in  this  state  of  preparation,  which  I  saw  in  the 
^bmet  of  the  Societe  Indusirielk  of  that  interesting  emporium  of  calico-printing. 
The  native  implements  for  applying  the  wax  and  coloring  bases  are  placed  along- 
side of  the  cloths,  and  form  a  curious  picture  of  primeval  art.  There  is  among 
other  samples  an  ancient  pallampoor,  five  French  yards  long,  and  two  and  a  half  broad 
jaid  to  be  the  labor  of  Hindoo  princesses,  which  must  have  taken  a  lifetime  to  execute* 
The  printing  machinery  of  great  Britain  has  begun  to  supersede,  for  these  styles  o} 
work,  the  cheapest  hand  labor  of  India. 

Calico-printing  has  been  for  several  hundred  years  practised  by  the  oriental  methods 
in  Asia  Minor  and  the  Levant;    but  it  was   unknown   as  an  English   art  till  1696 
when  a  small  print-ground  was  formed  upon  the  banks  of  the  Thames,  near  Richmond' 
by  a  Frenchman— probably  a  refugee  from  his  own  countr>',  in  consequence  of  the 
revocation    of  the  edict  of  Nantes.     Some    time   afterwards,  a   considerable   printine 
work  was  estabUshed  at  Bromley  Hall,  in  Essex,  and  several  others  sprung  up  succe^ 
sively  m  Surrey,  to  supply  the  London  shops  with  chintses,  their  import  from  India 
having  been  prohibited  by  act  of  parliament  in  1700.    The  silk  and  woollen  weavers 
indeed,  had  all  along  manifested  the  keenest  hostility  to  the  use  of  printed  calicoes' 
whether  brought  from  the  East  or  made  at  home.    In  the  year  1680  they  mobbed  the 
India  House   in   revenge   for  some  large   importations   then  made  of  the  chintses  of 
Malabar.     They  next  induced  the  government,  by  incessant  clamors,  to  exclude  alto- 
gether the  beautiful  robes  of  Calicut  from  the  British  market.    But  the  printed  goods, 
imported  by  the  English  and  Dutch  Easl  India  companies,  found  their  way  into  this 
country,  m  spite  of  the  excessive  penalties  annexed  to  smuggling,  and  raised  a  new  alarm 
among  the  manufacturing  population  of  Spitalfields.     The  sapient  legislators  of  that  dav 
intimidated  as  would  appear,  by  the  East  London  mobs,  enacted  in  1720  an  absurd 
sumptuary  law,  prohibiting  the  wearing  of  all  printed  calicoes  uhaisoever,  either  of  foreign 
or  domestic  ongin.     This  disgraceful  enactment,  "worthy  of  the  meridian  of  Cairo  or 
Algiers,  proved  not  only  a  death-blow  to  rising  industry  in  this  ingenious  department 
of  the  arts,  but  prevented  the  British  ladies  from  attiring  themselves  in  the  becoming 
drapery  of  Hmdostan.     After  an  oppressive  operation  of  ten  years,  this  act  was  repealed 
^,*  J^""^- •  7  enhghtened  set  of  senators,  who  were  then  pleased  to  permit  what  they 
called  British  calicoes,  if  made  of  linen  warp,  with  merely  weft  cf  ihe  kaied  cotton,  to  be 
printed  and  worn,  upon  paying  a  duty  of  no  less  than  sixpence  the  square  yard.    Under 
this  burden,  English  calico-printing  could  not  be  expected  to  make  a  rapid  progress. 
Accordingly,  even  so  lately  as  the  year   1750,  no  more  than  50,000  pieces  of  mixed 
Stuff  were  printed  m  Great  Britain,  and  that  chiefly  in  the  neighborhood  of  London  • 
whereas  a  single  manufacturer,  Mr.  Coates  of  Manchester,  now-a-days  will  turn  off 
nearly  twenty  times  that  quantity,  and  there  are  very  many  others  who  manufacture 
several  hundred  thousand  pieces  per  annum.    It  was  not  till  about  1766  that  this  art 
migrated  into  Lamcash ire,  where  it  has  since  taken  such  extraordinary  development- 
but  It  wa5  only  after  1774  that  it  began  to  be  founded  upon  right  principles,  in  consel 
quence  of  the  repeal  of  that  part  of  the  act  of  1730  which  required  the  warp  to  be  made 
of  linen  yarn.    Henceforth  the  printer,  though  still  saddled  with  a  heavy  duty  of  3d  the 
square  yard,  was  allowed  to  apply  his  colors  to  a  homogeneous  web,  instead  of  the  m'ixed 
labric  of  hnen  and  cotton  substances,  which  differ  in  their  affinities  for  dyes. 

France  pursued  for  some  time  a  similar  false  policy  with  regard  to  calico-printino-  but 
she  emerged  sooner  from  the  mists  of  manufacturing  monoiwly  than  England.  ""Her 
avowed  motive  was  to  cherish  the  manufacture  of  flax,  a  native  product,  instead  of  that 
^  cotton  a  raw  material,  for  which  prejudice  urged  that  money  had  to  be  exported. 
Her  intelligent  statesmen  of  that  day,  fully  seventy  years  ago,  replied  that  the  money 
expended  in  the  purchase  of  cotton  was  the  produce  of  French  industry,  beneficially 
employed,  and  they  therefore  took  immediate  measures  to  put  the  cotton  fabrics  upon  a 
footing  of  equality.  MeanwhUe  the  popular  prejudices  became  irritated  to  such  a  degree, 
by  the  project  of  permuting  the  free  manufacture  and  sale  of  printed  cottons,  that  ever^ 
French  town  possessed  of  a  chamber  of  commerce  made  the  strongest  remonstrances 
against  It.  The  Rouen  deputies  declared  to  the  government,  « that  the  intended  mea- 
sure won  d  throw  its  inhabitants  mto  despair,  and  make  a  desert  of  the  surrounding 
country:  those  of  Lyons  said,  "the  news  had  spread  terror  through  all  its  workshops  :^ 
Tours  "foresaw  a  commotion  likely  to  convulse  the  body  of  the  state  :"  Amiens  said, 
"that  the  new  law  would  be  the  grave  of  the  manufacturing  industry  of  France ;»  and 
Paris  declared  that  her  merchants  came  forward  to  bathe  the  throne  with  their  tears 
upon  that  inauspicious  occasion." 

The  government  persisted  in  carrying  its  truly  enlightened  principles  into  effect,  and 
with  so  manifest  advantage  to  the  nation,  as  to  warrant  the  inspector-general  of  manu 
!f5=i"^^«  *°  make,  soon  afterwards,  the  following  appeal  to  those  prejudiced  bodies  :- 
«  WiU  any  of  you  now  deny  that  the  fabrication  of  printed  cottons  has  occasioped  a  vast 
extension  of  the  industry  of  France,  by  giving  profitable  employment  to  a  great  many 


i 


hands  in  spinning,  weaving,  bleaching,  and  printing  the  colors  ?  Look  only  at  the  dyeing 
department,  and  say  whether  it  has  not  done  more  good  to  France  in  a  few  years  than 
many  of  your  other  manufactures  have  in  a  century  ?" 

The  despair  of  Rouen  has  been  replaced  by  the  most  signal  prosperity  in  the  cotton 
trade,  and  especially  in  printed  calicoes,  for  the  manufacture  of  which  it  possesses  70 
different  establishments,  producing  upwards  of  a  million  of  pieces  of  greater  average  size 
and  price  than  the  English.  In  the  district  of  the  Lower  Seine,  round  that  town,  there 
are  500  cotton  factories  of  different  kinds,  which  give  employment  to  118,000  operatives 
of  all  orders,  and  thus  procure  a  comfortable  livelihood  to  probably  not  less  than  half  a 
million  of  people. 

The  repeal,  in  1831,  of  the  consolidated  duty  of  S^d.  per  square  yard  upon  printed 
calicoes  in  Great  Britain  is  one  of  the  most  judicious  acts  of  modern  legislation.  By 
the  improvements  in  calico-printing,  due  to  the  modern  discoveries  and  inventions  in 
chem-rtry  and  mechanics,  the  trade  had  become  so  vast  as  to  yield  in  1830  a  revenue  of 
2,280,000/.  levied  upon  8,596,000  pieces,  of  which,  however,  about  .hree  fourths  were 
exported,  with  a  drawback  of  1,579,000/.  2,281,512  pieces  were  consumed  in  that  year 
at  home.  When  the  expenses  of  collection  were  deducted,  only  350,000/.  found  their 
way  into  the  exchequer,  for  which  pitiful  sum  thousands  of  frauds  and  obstructions  were 
committed  against  the  honest  manufacturer.  This  reduction  of  duty  enables  the  con- 
sumer to  get  this  extensive  article  of  clothing  from  50  to  80  per  cent,  cheaper  than 
before,  and  thus  places  a  becoming  dress  within  the  reach  of  thousands  of  handsome 
females  in  the  humbler  ranks  of  life.  Printed  goods,  which  in  1795  were  sold  for  two 
shillings  and  three-pence  the  yard,  may  be  bought  at  present  for  eight-pence.  In  fact,  a 
woman  may  now  purchase  the  materials  of  a  pretty  gown  for  two  shillings.  The  repeal 
of  the  tax  has  been  no  less  beneficial  to  the  fair  dealers,  by  putting  an  end  to  the  contra- 
band trade,  formerly  pursued  to  an  extent  equally  injurious  to  them  and  the  revenue. 
It  has,  moreover,  emancipated  a  manufacture,  eminently  dependant  upon  taste,  science, 
and  dexterity,  from  the  venal  curiosity  of  petty  excisemen,  by  whom  private  improve- 
ments, of  great  value  to  the  inventor,  were  in  perpetual  jeopardy  of  being  pirated  and 
sold  to  any  sordid  rival.  The  manufacturer  has  now  become  a  free  agent,  a  master  of 
his  time,  his  workmen,  and  his  apparatus ;  and  can  print  at  whatever  hour  he  may  re- 
ceive an  order ;  whereas  he  was  formerly  obliged  to  wait  the  convenience  of  the  excise 
oflicer,  whose  province  it  was  to  measure  and  stamp  the  cloth  before  it  could  be  packed, 
-—an  operation  fraught  with  no  little  annoyance  and  delay.  Under  the  patronage  of  par- 
liament, it  was  easy  for  needy  adventurers  to  buy  printed  calicoes,  because  they  could 
raise  such  a  sum  by  drawbacks  upon  the  export  of  one  lot  as  would  go  far  to  pay  for 
another,  and  thus  carry  on  a  fraudulent  system  of  credit,  which  sooner  or  later  merged 
in  a  disastrous  bankruptcy.  Meanwhile  the  goods  thus  obtained  were  pushed  ofi'  to 
some  foreign  markets,  for  which  they  were  possibly  not  suited,  or  where  they  produced, 
by  their  forced  sales,  a  depreciation  of  all  similar  merchandise,  ruinous  to  the  man  who 
meant  to  pay  for  his  wares. 

The  principles  of  calico-printing  have  been  very  profoundly  studied  by  many  of  the 
French  manufacturers,  who  generally  keep  a  chemist,  who  has  been  educated  in  the  Parisian 
schools  of  science,  constantly  at  work,  making  experiments  upon  colors  in  a  well-mounted 
laboratory.  In  that  belonging  to  M.  Daniel  Koechlin,  of  Mulhausen,  there  are  upwards 
of  3000  labelled  vials,  filled  with  chemical  reagents,  and  specimens  subservient  to  dyeing. 
The  great  disadvantage  under  which  the  French  printers  labor  is  the  higher  price  they 
pay  for  cotton  fabrics  above  that  paid  by  the  English  printers.  It  is  this  circumstance 
alone  which  prevents  them  from  becoming  very  formidable  rivals  to  us  in  the  markets  of 
the  world.  M.  Barbet,  deputy  and  mayor  of  Rouen,  in  his  replies  to  the  ministerial 
commission  of  inquiry,  rates  the  disadvantage  proceeding  from  that  cause  at  2  francs  per 
piece,  or  about  5  per  cent,  in  value.  In  the  annual  report  of  the  Societe  IndustrieVe  of 
Mulhausen,  made  in  December,  1833,  the  number  of  pieces  printed  that  year  in  Alsace 
is  rated  at  720,000,  to  which  if  we  add  1,000,000  for  the  produce  of  the  department  of 
the  Lower  Seine,  and  280,000  for  that  of  St.  Quentin,  Lille,  and  the  rest  of  France,  we 
shall  have  for  the  total  amount  of  this  manufacture  2,000,000  of  pieces,  equivalent  to 
nearly  2,400,000  pieces  English ;  for  the  French  piece  usually  measures  33J  aunes, 
=  41  yards  nearly ;  and  it  is  also  considerably  broader  than  the  English  pieces  upon 
an  average.  It  is  therefore  probable  that  the  home  consumption  of  France  in  printed 
goods  is  equal  in  quantity,  and  superior  in  value,  to  that  of  England.  With  regard  tc 
the  comparative  skill  of  the  workmen  in  the  two  countries,  M.  Nicholas  Koechlin,  deputy 
of  the  Upper  Rhine,  says,  that  one  of  his  foremen,  who  worked  for  a  year  in  a  print- 
field  in  Lancashire,  found  little  or  no  difference  between  them  in  that  respect.  The 
English  wages  are  considerably  higher  than  the  French.  The  machines  for  multiplying 
production,  which  for  some  time  gave  us  a  decided  advantage,  are  now  getting  into  very 
general  ^se  among  our  neighbors.  In  my  recent  visit  to  Mulhausen,  Rouen,  and  theif 
environs,  I  had  an  opportunity  of  seeing  many  printing  establishments  mounted  with  all 
the  resources  of  the  most  refined  mechanisms. 


310 


CALICO-PRmTING. 


« J**^  caJico-printing  of  this  country  stiU  labors  under  the  burden  of  considerable  taxes 
upon  madder  and  gallipoli  oil,  which  have  counteracted  the  prosperity  of  our  Turkey  red 
styles  of  work,  and  caused  them  to  flourish  at  Elberfeldt,  and  some  other  places  on  the 
conunent  whither  a  good  deal  of  the  English  yarns  are  sent  to  be  dyed,  then  brou«'ht 
back,  and  manufactured  into  ginghams,  checks,  &c.,  or  foi-warded  directly  .thence  to  our 
Kussian  customers.  This  fact  places  our  fiscal  laws  in  the  same  odious  light  as  the  fa- 
cility of  pirating  printers*  patterns  with  impunity  does  our  chancery  laws. 

Before  cloth  can  receive  good  figured  impressions  its  surface  must  be  freed  from  fibrous 
<lown  by  Singeing,  and  be  rendered  smooth  by  the  Calender.  See  these  articles  They 
*^  J  "^^*  bleached  wiih  the  exception  of  those  destined  for  Turkey  red.  See  Bleaching 
and  Madder.  AAer  they  are  bleached,  dried,  singed,  and  calendered,  they  are  lapped 
round  m  great  lengths  of  several  pieces,  stitched  endwise  together,  by  means  of  an  anpa- 
ratus  called  m  Manchester  a  candroy,  which  bears  on  its  front  edge  a  rounded  iron  bar 
transversely  grooved  to  the  right  and  left  from  the  centre,  so  as  to  spread  out  the  web  as 
It  is  drawn  over  it  by  the  rotation  of  the  lapping  roller.  See  a  figure  of  this  bar  sub- 
servient to  the  cylinder  prmting-machine. 

^?Z  ^f^^T  /°^t^«^\"e  jn  "se  for  imprinting  figures  upon  calicoes :  the  first  is  by 
Hnall  wooden  blocks,  on  whose  face  the  design  is  cut,  which  are  worked  by  hand ;  the  second 

^n  /Jt'^fi  ^^^;f  "i  ^^S^^^''  ^^^""^i '"  ^'^^^'  ^'^^  °^  ^^'^^  P^^n^S'  standing  at  ri?ht  angles 
to  each  other,  called  a  Perrotine,  from  the  name  of  its  inventor ;  the  third  is  by  flat  copper 

S.S  5  "^  f  now  almost  obsolete;  and  the  fourth  is  by  a  system  of  copper  cylinders, 
Tr T  fi  "  *  ^""^  ""^^J"^^  elegance,  but  no  little  complexity,  by  which  two,  three,  four 
or  even  five  colors  may  be  printed  on  in  rapid  succession  by  the  mere  rotation  of  the  ma- 
chine  driven  by  the  agency  of  steam  or  water.  The  productive  powers  of  this  printing 
automaton  are  very  great,  amounting  for  some  styles  to  a  piece  in  the  minute,  or  a  mile 
of  cloth  in  the  hour.  The  fifth  color  is  commonly  communicated  by  means  of  what  is 
called  a  surface  cylinder,  covered  with  wooden  figures  in  bass-relief,  which,  by  rotation, 
are  applied  to  a  plane  of  cloth  imbued  with  the  thickened  mordants. 

The  hand  blocks  are  made  of  sycamore  or  pear-tree  wood,  or  of  deal  fac•,^]  with  these 

woods,  and  are  from  two  to  three  inches  thick,  nine  or  ten  inches  long,  and  five  broad, 

with  a  strong  box  handle  on  the  back  for  seizing  them  by.    The  face  of  the  bJock  is  either 

carved  m  relief  into  the  desired  design,  like  an  ordinary  wood-cut,  or  the  figure  is  formed 

by  the  insertion  edgewise  into  the  wood  of  narrow  slips  of  flattened  copper  wire.    These 

tiny  fillets,  being  filed  level  on  the  one  edge,  are  cut  or  bent  into  the  proper  shape,  and 

forced  into  the  wood  by  the  taps  of  a  hammer  at  the  traced  lines  of  the  configuration. 

1  heir  upper  surfaces  are  now  filed  flat,  and  polished  into  one  horizontal  plane,  for  the 

sake  of  equality  of  impression.    As  the  slips  are  of  equal  thickness  in  th^ir  whole  depth 

from  having  been  made  by  running  the  wire  through  between  the  steel  cylinders  of  i 

flatting  mill,  the  Ime^s  of  the  figure,  however  much  they  get  worn  by  use,  are  always 

equally  broad  as  at  first;  an  advantage  which  does  not  belong  lo  wood-cutting     The 

interstices  between  the  ridges  thus  formed  are  filled  up  with  felt-stuff.     Sometimes  a 

aelicate  part  of  the  design  is  made  by  the  wood-cutter,  and  the  rest  by  the  insertion  of 

copper  slips.  ' 

The  coloring  matter,  properly  thickened,  is  spread  with  a  flat  brush,  by  a  child,  upon 
hne  woollen  cloth,  stretrUed  in  a  frame  over  the  wax  cloth  head  of  a  wooden  drum  or 
sieve,  which  floats  inverted  in  a  tubful  of  old  paste,  to  give  it  elastic  buoyancy.  The  in- 
verted sieve  drum  should  fit  the  paste  tub  pretty  closely.     The  printer  presses  the  face 

^!  f   \u        J^^  ^^^  ^""""^  ^^^'^^  ^**  ^'^  ^^  ^^^^  "P  ^^^  requisite  quantity  of  color,  applies 
It  to  the  surface  of  the  calico,  extended  upon  a  flat  table  covered  with  a  blanket,  and 
then  strikes  the  back  of  the  block  with  a  wooden  mallet,  in  order  to  transfer  the  impres- 
sion fully  10  the  cloth.     This  is  a  deUcate  operation,  requiring  equal  dexterity  and  dili- 
gence.    To  print  a  piece  of  cloth  25  yards  Ion?,  and  30  inches  broad,  no  less  than  672 
applications  of  a  block,  9  inches  long  and  5  inches  broad,  are  requisite  for  each  color; 
ffila        r    T  *'^n^^^  *'''^°''^'  «''  three  hands  as  the  French  term  it,  no  less  than 
2016  applications  will  be  necessary.    The  blocks  have  pin-points  fixed  into  their  corners, 
by  means  of  which  they  are  adjusted  to  their  positions  upon  the  cloth,  so  as  to  join  the 
different  parts  of  the  design  -nth  precision.    Each  printer  has  a  color-tub  placed 
Within  reach  of  his  right  hand;  and  for  every  different  color  he  must  have  a  separate 
sieve.     Many  manufacturers  cause  their  blocks  to  be  made  of  three  layers  of  Avood,  two 
of  them  being  deal  with  the  gram  crossed  to  prevent  warping,  and  the  third  sycamore  for 
engraving.  ' 

The  printing  shop  is  an  oblong  apartment,  lighted  with  numerous  windows  at  each 
side,  and  having  a  solid  table  opposite  to  each  window.  The  table  b, /?g  231,  is  formed 
of  a  strong  plank  of  well-seasoned  hard  wood,  mahogany,  or  marble,  with  a  surface  truly 
plane.  Its  length  is  about  6  feet,  its  breadth  2  feet,  and  its  thickness  3,  4,  or  5  inches. 
It  stands  on  strong  feet,  with  its  top  about  36  inches  above  the  floor.  At  one  of  its 
ends  there  are  two  brackets  c  for  supporUng  the  axles  of  the  roUer  e,  which  carries  th« 


CALICO-PRINTING 


311 


J 


white  calico  to  be  printed.  The  hanging  rollers  e  are  laid  across  joists  fixed  near  the  reef 
Tf  he^artment  above  the  printing  shop,  the  ceiling  and  floor  between  them  being  opca 
bar  work,  at  least  in  the  middle  of  the  room.  Their  use  is  to  facilitate  the  exposure, 
and  consequently,  the  drying  of  the  printed  pieces,  and  to  prevent  one  figure  being  daubed 
by  another:  Should  they  come  to  be  all  filled,  the  remainder  of  the  goods  must  be  folded 
lightly  upon  the  stool  d. 

E 
QQPQ 


B 


The  printer  stretches  a  length  of  the  piece  upon  his  table  a  b,  taking  care  to  place 
the  selvage  towards  himself,  and  one  inch  from  the  edge.  He  presents  the  block 
towards  the  end,  to  determine  the  width  of  its  impression,  and  marks  this  line  a  b,  by 
means  of  his  square  and  tracing  point.  The  spreader  now  besmears  the  cloth  with  the 
color,  at  the  commencement,  upon  both  sides  of  the  sieve  head ;  because,  if  not  uniformly 
applied,  the  block  will  take  it  up  unequally.  The  printer  seizes  the  block  in  his  right 
hand,  and  daubs  it  twice  in  different  directions  upon  the  sieve  cloth,  then  he  transfers  it 
to  the  calico  in  the  line  a  b,  as  indicated  by  the  four  points  abed,  corresponding  to 
the  four  pins  in  the  corners  of  the  block.  Having  done  so,  he  takes  another  daub  of 
the  color,  and  makes  the  points  a  b  fall  on  c  d,  so  as  to  have  at  the  second  stamp 
a'  b\  covering  a  b  and  c'  d' ;  and  so  on,  through  the  rest,  as  denoted  by  the  accented  let- 
ters.   When  one  table  length  is  finished,  he  draws  the  cloth  along,  so  as  to  bring  a  new 

length  in  its  place.  »  ,        ,  ,        •    .. 

The  grounding-in,  or  re-entering  (rentrage),  of  the  other  colors  is  the  next  process. 
The  blocks  used  for  this  purpose  are  furnished  with  pin-points,  so  adjusted  that,  when 
they  are  made  to  coincide  with  the  pin-points  of  the  former  block,  the  design  will  be  cor- 
rect ;  that  is  to  say,  the  new  color  will  be  applied  in  its  due  place  upon  the  flower  or  other 
figure.  The  points  should  not  be  allowed  to  touch  the  white  cloth,  but  should  be  made  to 
fall  upon  the  stem  of  a  leaf,  or  some  other  dark  spot.  These  rentraget  are  of  four  sorts  :— - 
I.  One  for  the  mordants,  as  above  ;  2.  one  for  topical  colors  ;  3.  one  for  the  application  of 
reds;  and,  4.  one  for  the  application  of  resist  pastes  or  reserves.  These  styles  have 
superseded  the  old  practice  of  pencilling.  .    .       ,  .      •    i  j 

The  Perrotine  is  a  machinj  for  executing  block-prinling  by  mechanical  power ;  and 
it  performs  as  much  work,  it  is  said,  as  20  expert  hands.  I  have  seen  its  operation,  in 
many  factories  in  France  and  Belgium,  in  a  very  satisfactory  manner;  but  I  have 
reason  to  believe  that  there  are  none  of  them  as  yet  in  this  country.  Three  wooden 
blocks,  from  2|  to  3  feet  long,  according  to  the  breadth  of  the  cloth,  and  from  2  to  5 
inches  broad,  faced  with  pear-tree  wood,  engraved  in  relief,  are  mounted  in  a  powerful 
cast-iron  frame  work,  with  their  planes  at  right  angles  to  each  other,  so  thai  each 
of  them  may,  in  succession,  be  brought  to  bear  upon  the  face,  top,  and  back  of  a 
square  prism  of  iron  covered  with  cloth,  and  fitted  to  revolve  upon  an  axis  between  the 
said  blocks.  The  calico  passes  between  the  prism  and  the  engraved  blocks,  and 
receives  successive  impressions  from  them  as  it  is  successively  drawn  through  by  a 
winding  cylinder.  The  blocks  are  pressed  against  the  calico  through  the  agency  of 
springs,  which  imitate  the  elastic  pressure  of  the  workman's  hand.  Each  block  receives 
a  coat  of  colored  paste  from  a  woollen  surface,  smeared  after  every  contact  with  a 
mechanical  brush.  One  man,  with  one  or  two  children  for  superintending  the  color- 
giving  surfaces,  can  turn  off  about  30  pieces  English  per  day,  in  three  colors,  which 
is  the  work  of  fully  20  men  and  20  children  in  block  printing  by  hand.  It  executet 
some  styles  of  work  to  which  the  cylinder  machine,  without  the  surface  roller,  m 
inadequate. 


312 


i 


CALICO-PRINTING. 


CALICO-PRINTING- 


313 


The  copper-plate  printing  of  calico  is  almost  exactly  the  same  as  that  used  foi  printins 
engravings  on  paper  from  flat  plates,  and  being  nearly  superseded  by  the  next  machine 
need  not  be  described.  -v.wMt, 

The  cylinder  printing  machine  consists,  as  its  name  imports,  of  an  enjrravcd  cooner 
cylinder,  so  mounted  as  to  revolve  against  another  cylinder  lapped  in  woollen  cloth  and 
imbued  with   a   colored  paste,  from   which   it  derives    the   means  of  communicating 

colored  impressions  to  pieces  of  calico  passed  over  it.  Fie  296 
will  give  the  reader  a  general  idea  of  this  elegant  and  expe- 
ditious plan  of  printing  The  pattern  is  engraved  upon  the 
rf!r  "S  *  ^«"7/yli?der  of  copper,  or 'sometimes  gun 
Li  i^^  he  cylinder  is  forced  by  pressure  upon  a  stfong 
iron  mandrel,  which  serves  as  its  turning  shaft.    To  facilitate 

ii  tH  tK  i\f  *  •^""P^^^''°''  '"^^"^  ^^^  engravin?  to  the  cotton 
cloth,  the  latter  is  lapped  round  another  large  cylinder,  rendered 
elastic  by  ro  Is  of  woollen  cloth,  and  the  engraved  cyS 
presses  the  calico  against  this  elastic  cushion,  and  thereby  prints 
it  as  it  revolves.  Let  a  be  the  engraved  cylinder  mounted  upon 
Its  mandrel,  which  receives  rotatory  motion  by  wheels  on  its 
end,  connected  with  the  steam  or  water  power  of  the  factory 

frames  of  the  machine.     Agamst  that  drum  the  engraved  cylin- 
.     1  .,    ^     **^f  ^  *?  pressed  by  weights  or  screws ;  the  weights  actinc-  steadilv 

by  levers,  upon  its  brass  bearings.     Round  the  drum  b  the  endless  web  of  feFf  nr  W«n 
ket  stuff  a  .,  travels  in  the  direction  of  the  arrow,  being  carrfed  round  alon^^ 
drum  B,  wh.ch  again  is  turned  by  the  friction  of  contact  with  the  cylinder  >    c  reDrc! 

Thit  r^oll  '•'^™^'.''  '""r^  "^^''^y  P^""°^^  ^"^°  '^^  thickened  colo/o?  the  trou'h  bT 
That  roller  is  also  made  to  bear,  with  a  moderate  force,  against  a,  and  thus  recefves  b^ 

fromT'  '"  VT  "^'f'  ^  movement  of  rotation.  But  it'is'preferable  to  dri^ve  the  rolL  c 
from  the  cyhnder  a,  by  means  of  a  system  of  toothed  wheels  attached  to  their  ends  so  that 
the  surface  speed  of  the  wooden  or  paste  roller  shall  be  somewhat  greater  than  that  of 

pa^f  of  th^'latr.'"'  "'"'''  ''^  ^°^°'  "'"  ^  "^''^'''  ^  ''  ^^^^  into'the^^n^r^lel 
As  the  cylinder  a  is  pressed  upwards  against  b,  it  is  obvious  that  the  bearpr^  nf  i>.« 
trough  and  its  roller  must  be  attached  "o  the  bearings  of  the  cvl  nder  a^LI  ^ 
preserve  its  contact  with  the  color-roller  c.     6  is  a  sh^  ed^d  V  f^^^^^^^^  Jj 

steel  caliedtheco/orrfoc/or,  screwed  between  two  gun-metal  stiffen  ngWs"  tTeed^e 
of  which  wiper  is  shghtly  pressed  as  a  tangent  upon  the  engraved  roller  A  This  rnW 
vibrates  with  a  slow  motion  from  side  to  side,  or  right  to  left,%o  as  to  exercise  a  delicitl 
shaving  action  upon  the  engraved  surface,  as  this  revolves  ri  the  directfonTthe  a  ro^^^ 
fir^^'\'-T^"  sharp-edged  ruler,  called  the  lint  doctor,  whose  offiie  it  s  to  remove 
any  fibres  which  may  have  come  off  the  calico  in  the  act  of  printing  and  which  inJft 
on  the  enffrared  cyhnder,  would  be  apt  to  occupy  some  of  the  lines   or  nt  l.,T.  !     '  . 

the  color  from  filling  them  all.     This'««.  doJJis  p'esstd  v:^  s^^^^^^^^ 
A,  and  has  no  transverse  motion.  ^  cjunaer 

What  was  stated  with  regard  to  the  bearers  of  the  color  trough  d,  namelv  that  ih^^ 
are  connected  and  moved  up  and  down  together  with  the  bearings  of  heTylinder  a  maJ 
also  be  said  of  the  bearers  of  the  two  doctors.  ^ji'uuer  a,  may 

The  working  of  this  beautiful  mechanism  may  now  be  ea^silv  comnrehpni^P^  Ti.- 
l"l"i  tn^'^'^i^^i-d  '^^  the  figure  by  the  letter  d,  is  iLX'^d  o^'carri^^^^^^^^^  aW 
with  the  blanket  stuff  a  a,  in  the  direction  of  the  a;row,  and  is  moved  onward  bv  tS! 

'^rV::ro:\tV^^-'  ^>'^^"^-^'-  -  -  -"^-  ^^^  in.pressiono1tr;^?eJj;?n! 
^ifihTAZ'tT^  '"^  1'''"^'  ^^'  ^""'^  '^"^P^^^  calico-machine  which  prints  upon 

^bonous  and  expensive  operation.  The  happy  invention  ^maTb^MrftLperS 
in  Amenca,  for  transferring  ensrav  nss  from  one  surface  in  .„«iLt  i.,,  /       ! 

roUer  dies,  was  with  great  judgment  applied  by  Mr  locket  in^^"  ^  ■  ,•  '  "^  ?'"' 
.go  as  the  year  ,808!  before  fhe  flrst'^?nven./r  clm^to'Eu  :p:trr;fan  °  fe 
pattern  is  iirst  drawn  upon  a  scale  of  about  3  inches  wuare  T.i>.,  Vi,:;  .-,  c'.  "* 
being  repeated  a  definite  number  of  times,  will  ioveMhe  cv^tnde/  Thf,  ..  f  •  *'"" 
engraved  in  intaglio  upon  a  roller  of  soflened  steel,  atout  I  «h  in'diameter"nd  3  ?„°k" 
loi.g,«>  that  ,t  wiU  exactly  occupy  its  surf«e.'    The  engraver  SI'S  eje;"*  11 


lens  when  employed  at  this  delicate  work.  This  roller  is  hardened  by  heating  it  to  a 
cherry-red  in  an  iron  case  containing  pounded  bone-a^,  and  then  plunging  it  into  cold 
water ;  its  surface  being  protected  from  oxydizement  by  a  chalky  paste.  This  hardened 
roller  is  put  into  a  press  of  a  peculiar  construction,  where,  by  a  rotatory  pressure,  it  trans 
fers  its  design  to  a  similar  roller  in  the  soft  state ;  and  as  the  former  was  in  intaglio,  thi 
latter  must  be  in  relievo.  This  second  roller  being  hardened,  and  placed  in  an  appro 
priate  volutory  press,  is  employed  to  engrave  by  indentation  upon  the  full-sized  coppei 
cylinder  the  whole  of  its  intended  pattern.  The  first  roller  engraved  by  hand  is  called 
the  die;  the  second,  obtained  from  it  by  a  process  like  that  of  a  milling  tool,  is  called  lh# 
mill.  By  this  indentation  and  multiplication  system,  an  engraved  cylinder  may  be  had  foi 
seven  pounds,  which  engraved  by  hand  would  cost  fifty  or  upwards.  The  restoration  of 
a  worn-out  cylinder  becomes  extremely  easy  in  this  way ;  the  mill  being  preserved,  need 
merely  be  properly  rolled  over  the  copper  surface  again. 

At  other  times,  the  hard  roller  die  is  placed  in  the  upper  bed  of  a  screw  press,  not  un- 
like that  for  coining,  while  the  horizontal  bed  below  is  made  to  move  upon  strong  rollers 
mounted  in  a  rectangular  iron  frame.    In  the  middle  of  that  bed  a  smooth  cake  or  flat 
disc  of  very  soft  iron,  about  1  inch  thick,  and  3  or  4  inches  in  diameter,  is  made  fast 
by  four  horizontal  adjusting  screws,  that  work  in  studs  of  the  bed  frame.    The  die  being 
now  brought  down  by  a  powerful  screw,  worked  by  toothed  wheel-work,  and  made  tc 
press  with  force  upon  the  iron  cake,  the  bed  is  moved  backwards  and  forwards,  causing 
the  roller  to  revolve  on  its  axles  by  friction,  and  to  impart  its  design  to  the  cake.    This 
iron  disc  is  now  case-hardened  by  being  ignited  amidst  horn  shavings  in  a  box,  and  then 
suddenly  quenched  in  water,  when  it  becomes  itself  a  die  in  relievo.    This  disc  die  is 
fixed  in  the  upper  part  of  a  screw  press  with  its  engraved  face  downwards,  yet  so  as  to  be 
moveable  horizontally  by  traverse  screws.     Beneath  this  inverted  bed,  sustained  at  its 
upper  surface  by  friction-rollers,  a  copper  cylinder  30  inches  long,  or  thereby,  is  mounted 
horizontally  upon  a  strong  iron  mandrel,  furnished  with  toothed  wheels  at  one  of  its 
ends,  to  communicate  to  it  a  movement  upon  its  axis  through  any  aliquot  arcs  of  the 
circle.     The  disc  die  being  now  brought  down  to  bear  upon  the  copper  cylinder,  this  is 
turned  round  through  an  arc  corresponding  in  length  to  the  length  of  the  die ;  and  thus, 
by  the  steady  downward  pressure  of  the  screw,  combined  with  the  revolution  of  the  cy- 
linder, the  transfer  of  the  engraving  is  made  in  intaglio.  This  is,  I  believe,  the  most  con- 
venient process  for  engraving,  by  transfer,  the  copper  of  a  one-cylinder  machine.    But 
when  2,  3,  or  4  cylinders  are  to  be  engraved  with  the  same  pattern  for  a  two,  three,  or 
four-colored  machine,  the  die  and  the  mill  roller  plan  of  transfer  is  adopted.   Tn  this 
case,  the  hardened  roller  die  is  mounted  in  the  upper  bed  of  the  transfer  press,  in  such  a 
way  as  to  be  capable  of  rotation  round  its  axis,  and  a  similar  roller  of  softened  steel 
IS  similarly  placed  in  the  under  bed.    The  rollers  are  now  made  to  bear  on  each  other  by 
the  action  of  the  upper  screw,  and  while  in  hard  contact,  the  lower  one  is  caused  to  re- 
volve, which,  carrying  round  the  upper  by  friction,  receives  from  it  the  figured  impression 
in  relief.    When  cylinders  for  a  three-colored  machine  are  wanted,  three  such  mills  are 
made  fac-similes  of  each  other;  and  the  prominent  parts  of  the  figure  which  belong  to 
the  other  two  copper  cylinders  are  filed  off  in  each  one  respectively.     Thus  three  differ- 
ently figured  mills  are  very  readily  formed,  each  adapted  to  engrave  its  particular  figure 
upon  a  distinct  copper  cylinder. 

Some  copper  cylinders  for  peculiar  styles  are  not  graved  by  indentation,  as  just  de- 
scribed, but  etched  by  a  diamond  point,  which  is  moved  by  mechanism  in  the  most  curious 
variety  of  configurations,  while  the  cylinder  slowly  revolves  in  a  horizontal  line  beneath  it. 
The  result  is  extremely  beautiful,  but  it  would  require  a  very  elaborate  set  of  drawings  to 
represent  the  machinery  by  which  Mr.  Locket  produces  it.  The  copper  is  covered  by  a  re- 
sist varnish  while  being  heated  by  the  transmission  of  steam  through  its  axis.  After  being 
etched,  it  is  suspended  horizontally  by  the  ends,  for  about  five  minutes,  in  an  oblong  trough 
charged  with  dilute  nitric  acid. 

With  regard  to  the  two  and  three-colored  machines,  we  must  observe,  that  as  the  calico 
in  passing  between  the  cylinders  is  stretched  laterally  from  the  central  line  of  the  web,  the 
figures  engraved  upon  the  cylinders  must  be  proportionally  shortened,  in  their  lateral  di- 
mensions especially,  for  the  first  and  second  cylinder. 

Cylinder  printing,  though  a  Scotch  invention,  has  received  its  wonderful  develop- 
ment in  England,  and  does  the  greatest  honor  to  this  country.  The  economy  of 
labor  introduced  by  these  machines  is  truly  marvellous ;  one  of  them,  under  the 
guidance  of  a  man  to  regulate  the  rollers,  and  the  service  of  a  boy,  to  supply  the 
color  troughs,  being  capable  of  printing  as  many  pieces  as  nearly  200  men  and  boys 
could  do  with  blocks.  The  perfection  of  the  engraving  is  most  honorable  to  our 
artisans.  The  French,  with  all  their  ingenuity  and  neat-handedness,  can  produce  nothing 
approaching  in  excellence  to  the  engraved  cylinders  of  Manchester, — a  painful  admission, 
universally  made  to  me  by  every  eminent  manufacturer  in  Alsace,  whom  I  visited  in  my 
late  tour. 


t» 


I     l< 


314 


CALICO-PRINTING 


Another  modification  of  cylinder  printing,  is  that  with  wooden  rollers  cut  in  relief;  it 
18  called  surface  printing,  probably  because  the  thickened  color  is  applied  to  a  tense  sar 
face  of  woollen  cloth,  from  which  the  roller  takes  it  up  by  revolving  in  contact  with  the 
cloth.    When  the  copper  cylinders  and  the  wooden  ones  are  combined  in  one  ajiu)arata8« 
it  has  got  the  appropriate  name  of  the  union  printing  machine. 

In  mounting  three  or  more  cylinders  in  one  frame,  many  more  adjustments  become  ne- 
cessary than  those  described  above.  The  first  and  most  important  is  that  which  ensures 
the  correspondence  between  the  part3of  the  figures  in  the  successive  printing  rollers,  fof 
unless  those  of  the  second  and  subsequent  engraved  cylinders  be  accurately  inserted  into 
their  respective  places,  a  confused  pattern  would  be  produced  upon  the  cloth  as  it  advan- 
ces round  the  pressure  cylinder  b,  figs.  233,  234. 

Each  cylinder  must  have  a  forward  adjustment  in  the  direction  of  rotation  round  its 
axis,  so  as  to  bring  the  patterns  into  correspondence  with  each  other  in  the  length  of  the 
piece;  and  also  a  lateral  or  traverse  adjustment  in  the  line  of  its  axis,  to  efllect  the  corres- 
pondence of  the  figures  across  the  piece ;  and  thus,  by  both  together,  each  cylinder  may 
be  made  to  work  symmetrically  with  its  fellows. 

Fig.  297  is  a  cross  section  of  a  four-color  cylinder  machine,  by  which  the  working 
parts  are  clearly  illustrated. 

A  A  A  is  a  part  of  the  two  strong  iron  frames  or  cheeks,  in  which  the  various  rollers 
are  mounted.     They  are  bound  together  by  the  rods  and  bolts  a  a  a  a. 

B  is  the  large  iron  pressure  cylinder,  which  rests  with  its  gudgeons  in  bearings  or  bnsh- 
es,  which  can  be  shifted  up  and  down  in  slots  of  the  side  cheeks  a  a.  These  bus'ues  are 
suspended  from  powerful  screws  6,  which  turn  in  brass  nuts,  made  fast  to  the  top  of  the 
frame  a,  as  is  plainly  shown  in  the  figure.  These  screws  serve  to  counteract  the  strong 
pressure  applied  beneath  that  cylinder,  by  the  engraved  cylinders  d  e. 

c  D  E  F  are  the  four  printing  cylinders,  named  in  the  order  of  their  operation.  Thfy 
consist  of  strong  tubes  of  copper  or  gun-metal,  forcibly  thrust  by  a  screw  press  upon  the 
iron  mandrels,  round  which  as  shafts  they  revolve. 

The  first  and  last  cylinder  c  and  f  are  mounted  in  brass  bearings,  which  may  be  shifled 
in  horizontal  slots  of  the  frame  a.  The  pressure  roller  b,  against  whose  surface  they 
bear  with  a  very  little  obliquity  downwards,  may  be  nicely  adjusted  to  that  pressure  by  its 
elevating  and  depressing  screws.  By  this  means  c  and  r  can  be  adjusted  to  b  with  geo- 
metrical precision,  and  made  to  press  it  in  truly  opposite  directions. 

The  bearings  of  the  cylinders  d  and  e  are  lodged  also  in  slots  of  the  frame  a,  which 
point  obliquely  upwards,  towards  the  centre  of  b.  The  pressure  of  these  two  print  cylin- 
ders c  and  F  is  produced  by  two  screws  c  and  rf,  which  work  in  brass  nuts,  made  fast 
to  the  frame  and  very  visible  in  the  figure.  The  frame-work  in  which  these  bearings  and 
screws  are  placed,  has  a  curvilinear  form,  in  order  to  permit  the  cylinders  to  be  readily 
removed  and  replaced;  and  also  to  introduce  a  certain  degree  of  elasticity.  Hence  the 
pressure  applied  to  the  cylinders  c  and  f,  partakes  of  the  nature  of  a  spring ;  a  circum- 
stance essential  to  their  working  smoothly,  on  account  of  the  occasional  inequalities  in  the 
thickness  of  the  felt  web  and  the  calico. 

The  pressure  upon  ir.e  other  two  print  cylinders  d  and  e  is  produced  by  weights  acting 
with  levers  against  the  bearings.  The  bearings  of  d  are,  at  each  of  their  ends,  acted 
upon  by  cylindrical  rods,  which  slide  in  long  tubular  bosses  of  the  frame,  and  press  with 
their  nuts  g  at  their  under  end  upon  the  small  arms  of  two  strong  levers  g,  which  lie  on 
each  side  of  the  machine,  and  whose  fulcrum  is  at  h  (in  the  lower  corner  at  the  left  hand). 
The  long  arms  of  these  levers  g,  are  loaded  with  weights  h,  whereby  they  are  made  to 
press  up  against  the  bearings  of  the  roller  p,  with  any  degree  of  force,  by  screwing  up 
the  nut  g,  and  hanging  on  the  requisite  weights. 

The  manner  in  which  the  cylinder  e  is  pressed  up  against  b,  is  by  a  similar  construc- 
tion to  that  just  described.  With  each  of  its  bearings,  there  is  connected  by  the  link  Jfc, 
a  curved  lever  i,  whose  fulcrum  or  centre  of  motion  is  at  the  bolt  /.  To  the  outer  end 
of  this  lever,  a  screw,  w,  is  attached,  which  presses  downwards  upon  the  link  n,  connect- 
ed with  the  small  arm  of  the  strong  lever  fe,  whose  centre  of  motion  is  at  o.  By  turning 
therefore  the  screw  m,  the  weight  l,  laid  upon  the  end  of  the  long  arm  of  the  lever  k  (o1f 
which  there  is  one  upon  each  side  of  the  machine),  may  be  made  to  act  or  not  at  pleasure 
upon  the  bearings  of  the  cylinder  e. 

In  tracing  the  operation  of  this  exquisite  printing  machine,  we  shall  begin  with  the 
first  engraved  cylinder  c.  Its  bearings  or  bushes  shift,  as  was  already  stated,  in  slots  of 
the  frame  A.  Each  of  them  consists  of  a  round  piece  of  iron,  to  which  the  end  of  the 
screw  c  is  joined,  in  the  same  way  as  at  d,  in  the  opposite  side.  In  each  of  these  iron 
bearings,  a  concave  brass  is  inserted  to  support  the  collar  of  the  shaft,  and  in  a  dove- 
tailed slit  of  this  brass,  a  slidins:  piece  is  fitted,  upon  which  a  set  or  adjusting  screw  in 
the  iron  bearing  acts,  and  which,  being  forced  against  the  copper  cylinder  c,  serves  to 
adjust  the  line  of  its  axis,  and  to  keep  it  steady  between  its  bearings,  and  true  in  its 
rotatory  motion.    Upon  the  iron  bearing  a  plate  is  screwed,  provided  with  two  flanges^ 

15 


CALICO-PRINTING. 


315 


which  support  the  color  trough  9,  and  the  color  roller  m.    This  trough,  as  well  as  the 
others  to  be  mentioned  presently,  is  made  of  sheet  copper  in  the  sides  and  bottom,  and 

297 


fixed  upon  a  board ;  but  its  ends  are  made  of  plates  of  cast  copper  or  gun-metal  to  serve 
as  bearings  to  the  color  roller  m.  The  trough  and  its  roller  may  be  shifted  both  together 
into  contact  with  the  printing  cylinder  c,  by  means  of  the  screw  r.  Near  s,  seen  above 
the  roller,  c,  and  t  below  it,  are  sections  of  the  two  doctors,  which  keep  the  engraved 
cylinders  in  sound  working  condition ;  the  former  being  the  colour  doctor,  and  the  latter 
tte  lint  doctor.  Their  ends  lie  in  brasses,  which  may  be  adjusted  by  the  screws  u  and  v, 
working  in  the  respective  brackets,  which  carry  their  brasses,  and  are  made  fast  to  the 
iron  bearings  of  the  cylinder. 

The  pressure  of  the  color  doctor  is  produced  by  two  weights  tr,  (see  high  up  on  the 
frame  work,)  which  act  on  a  pair  of  small  levers  x,  (one  on  each  side  of  the  machine,) 
and  thus,  by  means  of  the  chains,  tend  to  lift  the  arms  y,  attached  to  the  end  axles  of  the 
doctor.  The  pressure  of  the  lint  doctor  upon  the  cylinder  c,  is  performed  by  the  screw 
t,  pressing  upon  an  arm  which  projects  downwards,  and  is  attached  to  the  axle  of  that 
doctor. 

The  bearings  of  the  second  printing  cylinder  d,  consist  at  each  end  of  a  mass  of  iron 
(removed  in  the  drawing  to  show  the  mechanism  below  it),  which  shifts  in  the  slanting 
slot  of  the  frame  a.  In  each  of  these  masses  there  is  another  piece  of  iron,  which  slides 
in  the  transverse  direction,  and  may  be  shifted  by  the  adjusting  screw  a'  fixed  to  it,  and 
working  in  a  nut  cast  upon  the  principal  bearing  above  described.  To  the  inner  bear 
ings,  which  carry  the  brasses  in  which  the  shaft  lies,  are  screwed  the  two  curved  ann* 
6'  h'  to  which  are  attached  the  bearings  &c.,  for  the  color  trough  and  the  doctors.  In 
these  brasses  there  are  also  dovetailed  pieces,  which  slide  and  are  pressed  by  set  screws 
furnished  with  square  heads  in  the  iron  secondary  bearings,  which  sei  ve,  as  before  said,  to 
adjust  the  printing  cylinder  in  the  line  of  its  axis,  while  other  screws  adjust  the  distance 
of  the  cloth  upon  which  the  second  color  is  printed,  and  the  line  of  contact  with  the 
cylinder  b. 

N,  is  the  color  roller  of  d,  and  d'  the  color  trough,  which  rests  by  its  board  upon  the 
lever  e";  whose  centres  of  motion /'«  are  made  fast  to  the  curved  arms  6',  fixed  at  the 


316 


CALICO-PRINTING. 


CALICO-PRINTING 


S17 


bearings  of  the  cylinder,  and  whose  ends  are  suspended  by  screws  g' ;  whereby  the  color 
roller  n,  may  be  pressed  with  greater  or  less  force  to  the  cylinder  d.  h'  and  t'  are  the 
two  doctors  of  this  cylinder ;  the  former  being  the  color,  the  latter  the  lint  doctor. 
They  rest,  as  was  said  of  the  cylinder  c,  in  brasses  which  are  adjustable  by  means  of 
screws,  that  work  in  the  studs  or  brackets  by  which  the  brasses  are  supported.  These 
brackets  must  of  course  be  screwed  to  the  secondary  bearing-pieces,  in  order  that  they 
may  keep  their  position,  into  whatever  direction  the  bearings  may  be  shifted,  k'  and  /' 
are  these  set  screws  for  the  color  and  lint  doctors.  The  pressure  of  the  former  upon  the 
cylinder  d,  is  produced  by  weights  m',  acting  upon  levers  »',  and  pressing  by  rods  or  links 
o',  upon  arms  attached  to  each  end  of  the  axis  of  the  docliw.  (See  the  left  hand  side  of 
the  figure  near  the  bottom.)  The  lint-doctor  i'  is  pressed  in  a  similar  way  at  the  other 
side  upon  the  cylinder  d,  by  the  weights  acting  upon  levers  p',  and  by  rods  q'  upon  arms 
fixed  at  each  end  of  the  axis  of  the  doctor. 

The  bearings  of  the  third  printing  cylinder  e,  are  of  exactly  the  same  construction  as 
that  above  described,  and  therefore  require  no  particular  detail.  The  lint  doctor  *,  is 
here  pressed  upon  the  engraved  cylinder  by  screws  /',  working  in  the  ends  of  studs  or 
arms  fixed  upon  each  end  of  the  axis  of  the  doctor,  and  pressing  upon  flanges  cast  upon 
the  brackets  in  which  the  brasses  of  the  doctor's  axis  lie,  which  are  made  fast  to  the  bear- 
ings of  the  cylinder  e. 

The  bearings  of  the  fourth  copper  cylinder  f,  are  also  constructed  in  a  similar  way. 
Each  consists  of  a  first  bearing,  to  which  is  joined  the  end  of  the  screw  d,  by  which  it 
is  made  to  slide  in  a  slot  of  the  frame.  Another  bearing,  which  contains  the  brass  for 
the  shaft  of  the  cylinder,  can  be  shifted  up  and  down  in  a  transverse  direction  by  a  screw 
ar',  of  the  second  bearing,  working  in  a  nut  cast  upon  the  first  bearing.  To  this  secondary 
bearing,  plates  are  made  fast  by  the  screws  v'  v'  to  the  inside,  to  carry  the  studs  or 
brackets  of  the  doctors  x'  and  y'.  In  the  brasses  of  the  cylinder  shaft,  dovetailed  pieces 
are  made  to  slide,  being  pressed  by  set  screws  w',  against  the  engraved  cylinder  f,  similar 
to  what  has  been  described  for  adjusting  the  cylinders  to  one  another.  This  cylinder  has 
no  separate  color  roller,  nor  trough,  properly  speaking,  but  the  color  doctor  y'  is  made 
concave  to  serve  the  purpose  of  a  trough  in  supplying  the  engraved  lines  of  the  cylinder 
with  color.  With  this  view  the  top  plate  of  the  doctor  is  curved  to  contain  the  colored 
paste,  and  it  is  shut  up  at  the  ends  by  pieces  of  wood  made  to  fit  the  curvature  of  the  doctor. 
Its  pressure  against  the  engraved  surface  is  produced  by  weights  a",  acting  at  the  ends 
of  arms  6",  attached  to  the  ends  of  the  axis  of  the  doctor.  The  pressure  of  the  lint 
doctor  x'  is  given  by  screws  c",  working  in  arms  attached  to  the  ends  of  the  axis  of  the 
doctor,  and  pressing  upon  the  flanges  d",  cast  upon  the  brackets  which  carry  the  brasses 
for  the  axis  of  the  doctor.  These  brasses  are  themselves  adjustable,  like  those  of  all  the 
other  cylinders,  by  set  screws  in  the  brackets,  which  work  in  the  nuts  formed  in  the 
brasses. 

e"  e",  is  the  endless  web  of  felt  stuff  which  goes  round  the  cylinder  b,  and  constitutes 
the  soft  elastic  surface  upon  which  the  printing  cylinders  c,  d,  e,  and  f  exercise  their 
pressure.  This  endless  felt  is  passed  over  a  set  of  rollers  at  a  certain  distance  from  the 
machine,  to  give  opportunity  for  the  drying  up  of  any  coloring  paste  which  it  may 
have  imbibed  from  the  calico  in  the  course  of  the  impressions.  In  its  return  to  the  ma- 
chine in  the  direction  of  the  arrow,  it  is  led  over  a  guide  roller  o,  which  is  thereby  made 
to  revolve.  Upon  the  two  ends  of  this,  and  outside  of  the  bearings  which  are  fixed  upon 
the  tops  of  the  frame  a,  are  two  eccentrics,  one  of  which  serves  to  give  a  vibratory  tra- 
verse movement  to  the  color  doctors  «',  h',  and  r'  of  the  three  cylinders,  c,  d,  and  £, 
whilst  the  other  causes  the  color  doctor  y'  of  the  cylinder  f,  to  make  lateral  vibra- 
tions. 

Q  is  one  of  a  pair  of  cast-iron  brackets,  screwed  on  at  the  back  of  the  side-frames  or 
cheeks  a  a,  to  carry  the  roller  fiUed  with  white  calico  r,  ready  for  the  printing  operations. 
Upon  the  end  of  the  shaft  whereon  the  calico  is  coiled,  a  pulley  is  fixed,  over  which  a 
rope  passes  suspending  a  weight  in  order  to  produce  friction,  and  thereby  resistance  to 
the  action  which  tends  to  unwind  the  calico.  In  winding  it  upon  that  and  similar 
rollers,  the  calico  is  smoothed  and  expanded  in  breadth  by  being  passed  over  one  or 

more  grooved  rods,  or  over  a  wooden  bar  s,}lg.  298,  the  surface 
of  which  is  covered  with  wire,  so  as  to  have  the  appearance  of  a 
united  right  and  left-handed  screw.  By  this  device,  the  calico, 
folded  or  creased  at  any  part,  is  stretched  laterally  from  the 
298  S  centre,  and  made  level.    It  then  passes  over  the  guide-roller 

o,  where  it  comes  upon  the  surface  of  the  felt  c"  e",  and  thence  proceeds  under  its  guid- 
ance to  the  series  of  printing  cylinders. 

Three  and  four-color  machines,  similar  to  the  above,  are  now  at  work  in  many  es- 
tablishments in  Lancashire,  which  will  turn  off  a  piece  of  28  yards  per  minute,  each  of 
the  three  or  four  cylinders  applying  its  peculiar  part  of  the  pattern  to  the  cloth  as  it 
passes  along,  by  ceaseless  rotation  of  the  unwearied  wheels.    At  this  rate,  the  astonishing 


length  of  one  mile  of  many-colored  web  is  printed  witn  elegant  flowers  and  other 
figures  in  an  hour.  When  we  call  to  mind  how  much  knowledge  and  skill  are  involved 
In  this  process,  we  may  fairly  consider  it  as  the  greatest  achievement  of  chemical  and 
mechanical  science. 

Before  entering  upon  the  different  styles  of  work  which  constitute  calico-printing,  1 
shall  treat,  in  the  first  place,  of  what  is  common  to  them  all,  namely,  the  thickening  ol 
the  mordants  and  colors.  This  is  an  operation  of  the  greatest  importance  towards  the 
successful  practice  of  the  art.  Several  circumstances  may  require  the  consistence  of  the 
thickening  to  be  varied ;  such  as  the  nature  of  the  mordant,  its  density,  and  its  acidity. 
A  strong  acid  mordant  cannot  be  easUy  thickened  with  starch ;  but  it  may  be  by  roasted 
starch,  vulgarly  called  British  gum,  and  by  gum  arabic  or  Senegal.  Some  mordants 
which  seem  sufficiently  inspissated  with  starch,  liquefy  in  the  course  of  a  few  days,  and, 
being  apt  to  run  in  the  priniing-on,  make  blotted  work.  In  France,  this  evil  is  readily 
obviated  by  adding  one  ounce  of  spirits  .of  wine  to  half  a  gallon  of  color — a  remedy 
which  the  English  excise  duties  render  too  costly. 

The  very  same  mordant,  when  inspissated  to  difierent  degrees,  produces  diflferent  tints 
in  the  dye-copper — a  diflerence  due  to  the  increased  bulk  from  the  thickening  substance ; 
thus,  the  same  mordant,  thickened  with  starch,  furnishes  a  darker  shade  than  when 
thickened  with  gum.  Yet  there  are  circumstances  in  which  the  latter  is  preferred,  be- 
cause it  communicates  more  transparency  to  the  dyes,  and  because,  in  spite  of  the  wash- 
ing, more  or  less  of  the  starch  always  sticks  to  the  mordant.  The  gum  has  the 
inconvenience,  however,  of  drying  too  speedily,  and  of  also  increasing  too  much  the 
volume  of  the  mordants ;  by  both  of  which  causes  it  obstructs  their  combination  with  the 
stuflf,  and  the  tints  become  thin  or  scratchy. 

The  substances  generally  employed  as  thickeners  are  the  following : — 

1.  Wheat  starch. 

2.  Flour. 

3.  Roasted  starch. 

4.  Gum  Senegal. 

5.  Gum  tragacanth. 

6.  Salep. 

7.  Pipe-clay,  mixed  with  gum  Senegal. 

8.  Sulphate  of  lead. 

9.  Sugar. 

10.  Molasses. 

11.  Glue. 

After  thickening  with  gum,  we  ought  to  avoid  adding  metallic  solutions  in  the  liquid 
state ;  such  as  nitrate  of  iron,  of  copper,  solutions  of  tin,  of  subacetate  of  lead,  &c. ; 
•8  they  possess  the  property  of  coagulating  gum.  I  shall  take  care  to  specify  the  nature 
mnd  proportion  of  thickening  to  be  employed  for  each  color ;  a  most  important  matter, 
hitherto  neglected  by  English  writers  upon  calico-printing. 

The  atmosphere  of  the  printing  shops  should  never  be  allowed  to  cool  under  65®  or 
70°  F. ;  and  it  should  be  heated  by  proper  stoves  in  cold  weather,  but  not  rendered  too 
dry.  The  temperature  and  moisture  should  therefore  both  be  regulated  with  the  aid  oi 
thermometers  and  hydrometers,  as  they  exercise  a  great  influence  upon  all  the  printing 
processes,  and  especially  upon  the  combination  of  the  mordant  with  the  cloth.  In  the 
course  of  the  desiccation,  a  portion  of  the  acetic  acid  evaporates  with  the  water,  and  sub- 
acetates  are  formed,  which  combine  with  the  stuff  in  proportion  as  the  solvent  principle 
escapes ;  the  water,  as  it  evaporates,  carries  off  acetic  acid  with  it,  and  thereby  aids  the 
fixation  of  bases.  These  remarks  are  peculiarly  appropriate  to  delicate  impressions  by 
the  cylinder  machine,  where  the  printing  and  drying  are  both  rapidly  effected.  In  the 
lapis  lazuli  style,  the  strong  mordants  are  apt  to  produce  patches,  being  thickened  with 
pipe-clay  and  gum,  which  obstruct  the  evaporation  of  the  acids.  They  are  therefore  apt 
to  remain,  and  to  dissolve  a  portion  of  the  mordants  at  their  immersion  in  the  blue  vat, 
or  at  any  rate  in  the  dnng  bath.  In  such  a  case,  a  hot  and  humid  air  is  indispensable, 
after  the  application  of  the  mordants,  and  sometimes  the  stuffs  so  impregnated  must  be 
suspended  in  a  damp  chamber.  To  prevent  the  resist  pastes  becoming  rapidly  crusty, 
substances  apparently  useless  are  mixed  with  them,  but  which  act  beneficially  by  their 
hygrometric  qualities,  in  retarding  the  desiccation.  Oil  also  is  sometimes  added  with 
that  view. 

It  is  often  observed  that  goods  printed  upon  the  same  day,  and  with  the  same  mordant, 
exhibit  inequalities  in  their  tints.  Sometimes  the  color  is  strong  and  decided  in  one 
part  of  the  piece,  while  it  is  dull  and  meager  in  another.  The  latter  has  been  printed 
m  too  dry  an  atmosphere.  In  such  circumstances  a  neutral  mordant  answers  best,  et>pe> 
eiaUy  if  the  goods  be  dried  in  a  hot  flue,  through  which  humid  vapors  are  in  constant 
circulation. 

In  padding,  where  the  whole  surface  of  the  calico  is  imbued  with  mordant,  the  drying 


318 


CALICO-PRINTING. 


CALICO-PRINTING. 


319 


apartmeiit  ii  flue,  in  which  a  great  many  pieces  are  exposed  at  once,  shoulil  be  so  con- 
stnicted  as  to  afford  a  ready  outlet  to  the  aqueous  and  acid  exhalations.  The  cloth  oa^ht 
to  be  introduced  into  it  in  a  distended  state;  becamse  the  acetic  acid  ma/  accumulate  in 
the  foldings,  and  dissolve  out  the  earthy  or  metallic  base  of  the  mordant,  causing  white 
and  gray  spots  in  such  parts  of  the  printed  goods.  Fans  may  be  employed  with  great  ad- 
vantage, combined  with  Hot  Flues.     (See  this  article.) 

In  the  color  laboratory,  all  the  decoctions  requisite  for  the  print  work  should  be  ready 
prepared.  They  are  best  made  by  a  steam  heat,  by  means  of  copper  boilers  of  a  cylin^ 
dric  form,  rounded  at  the  bottom,  and  incased  within  a  cast-iron  cylinder,  the  steam  being 
supplied  to  the  space  between  the  two  vessels,  and  the  dye-stuff  and  water  being  intro- 
duced into  the  interior  one,  which  for  some  delicate  purposes  may  be  made  of  tin,*or  cop- 
per tinned  inside.  A  range  of  such  steam  apparatus  should  be  placed  either  along  one  of 
the  side  walls,  or  in  the  middle  line  of  the  laboratory.  Proper  tables,  diawers,  vials, 
with  chemical  reagents,  measures,  balances,  &c.,  should  also  be  provided.  The  most  use- 
ful dye-extracts  are  the  following : — 

Decoction  of  logwood,  of  Brazil-wood,  of  Persian  berries,  of  quercitron  bark,  of  nuU 
galls,  of  old  fustic,  of  archil  or  cutbear,  of  cochineal,  of  cochineal  with  ammonia,  of 
catechu. 

The  following  mordants  should  also  be  kept  ready  prepared : — 

1.  Aluminous  mordant. 

Take  50  gallons  of  boiling  water. 

100  lbs.  of  alum. 

10  lbs.  of  soda  crystals. 

75  lbs.  of  acetate  of  lead. 
The  soda  should  be  added  slowly  to  the  solution  of  the  alum  in  the  water,  and  when 
the  effervescence  is  finished,  the  pulverized  acetate  of  lead  is  put  in  and  well  stirred  about 
till  it  be  all  dissolved  and  decomposed.  During  the  cooling,  the  mixture  should  be  raked 
up  a  few  times,  and  then  allowed  to  settle.  The  supernatant  liquor  is  the  mordant ;  it  has 
a  density  of  IP  or  11^°  Baume.  It  serves  for  reds  and  pinks,  and  enters  into  the  com- 
position of  puce  and  lilach. 

2.  Aluminous  mordant. 
Take  50  gallons  of  water. 

100  lbs.  of  alum. 
10  lbs.  of  soda  crystals. 

100  lbs.  of  acetate  of  lead ; — operate  as  above  directed. 
The  supernatant  liquor  here  has  a  density  of  12°  Baume ;  it  is  employed  for  lapis  resists 
or  reserves,  and  the  cylinder  printing  of  madder  reds. 

3.  Aluminous  mordant. 
Take  50  gallons  of  water. 

100  lbs  of  alum. 
6  lbs.  of  soda  crystals. 

50  lbs.  of  acetate  of  lead  ; — operate  as  above  directed. 
This  mordant  is  employed  for  uniform  yellow  grounds. 

4.  Aluminous  mordant. 

This  is  made  by  adding  potash  to  a  solution  of  alum,  till  its  earth  begins  to  be  separa- 
ced,  then  boiling  the  mixture  to  precipitate  the  subsulphate  of  alumina,  which  is  to  be 
strained  upon  a  filter,  and  dissolved  in  acetic  acid  of  moderate  strength  with  the  aid  of 
beat.    This  mordant  is  very  rich  in  alumina,  and  marks  20°  B. 

5.  Aluminous  mordant. 
Take  12^  gallons  of  water. 

100  lbs.  of  alum. 

150  lbs.  of  lifiuid  pyrolignite  of  lime  at  11|°  Baume. 
This  mordant  is  made  with  heat  like  the  first;  after  cooling,  some  alum  crystallizes, 
and  It  marks  only  12^°  B.  ' 

A  mordant  is  made  by  solution  of  alum  in  potash,  commonly  called — 

6.  Aluminate  of  potash.  The  caustic  ley  is  prepared  by  boiling  together  for  an  hour 
100  ga^ns  of  water,  200  lbs.  of  potash,  and  80  lbs.  of  quicklime;  the  mixture  is  then 
allowed  to  settle,  the  supernatant  liquor  is  decanted,  and  evaporated  till  its  density  be  35" 
B.  In  30  gallons  of  that  ley  at  a  boiling  heat,  100  lbs.  of  ground  alum  are  to  be  dissolved. 
On  cooling,  crystals  of  sulphate  of  potash  separate.  The  clear  liquor  is  to  be  decanted  off. 
and  the  crystals  being  washed  with  a  little  water,  this  is  to  be  added  to  the  ley.  About 
33  gallons  of  mordant  should  be  obtained. 

Mordant  for  Bluck, 
The  pyrolignite  of  iron,  called  iron  liquor  in  this  country,  is  the  only  mordant  used  in 
calico-printing  for  black,  violet,  puce,  and  brown  colors.    The  acetate  of  alumina,  pre- 
pared from  pyroligneous  acid,  is  much  used  by  the  calico-printers  under  the  name  of  red  ot 
yellow  liquor,  being  employed  for  these  dyes. 


I 


We  may  observe  that  a  strong  mordant,  like  No.  2,  does  not  keep  so  well  as  one  ol 
mean  density,  such  as  No.  1.  Too  much  mordant  relatively  to  the  demands  of  the  works 
should  therefore  not  be  made  at  a  time. 

There  are  eight  different  styles  of  calico-printing,  each  requiring  different  methods  of 
manipulation,  and  peculiar  processes. 

1.  The  madder  style,  to  which  the  best  chintses  belon?,  in  which  the  mordants  are  api. 
plied  to  the  white  cloth  with  many  precautions,  and  the  colors  are  afterwards  brought  up 
in  the  dye-bath.    These  constitute  permanent  prints. 

2.  The  padding  or  plaquage  style,  in  which  the  whole  surface  of  the  calico  is  imbued  with 
a  mordant,  upon  which  afterwards  different  colored  fisures  may  be  raised,  by  the  topical 
application  of  other  mordants  joined  to  the  actir -n  of  the  dye-bath. 

3.  The  reserve  style,  where  the  white  cloth  is  impressed  with  figures  in  resist  paste, 
and  is  afterward  subjected  first  to  a  cold  dye,  as  the  indigo  vat,  and  then  to  a  hot  dye- 
bath,  with  the  effect  of  producing  white  or  colored  spots  upon  a  blue  ground. 

4.  The  discharge  or  rongeant  style,  in  which  thickened  acidulous  matter,  either  pure  of 
mixed  with  mordants,  is  imprinted  in  certain  points  upon  the  cloth,  which  is  afterwaids 
padded  with  a  dark-colored  mordant,  and  then  dyed,  with  the  effect  of  showing  bright 
figures  on  a  darkish  ground.  » 

5.  China  blues;  a  style  resembling  blue  stone-ware,  which  requires  very  peculiar 
treatment. 

6.  The  decoloring  or  enlevage  style;  by  the  topical  application  of  chlorine  or  chromic 
acid  to  dyed  goods.     This  is  sometimes  called  a  discharge. 

7.  Steam  colors ;  a  style  in  which  a  mixture  of  dye  extracts  and  mordants  is  topical- 
ly applied  to  calico,  while  the  chemical  reaction  which  fixes  the  colors  to  the  fibre  is  pro- 
duced  by  steam. 

8.  Spirit  colors ;  produced  by  a  mixture  of  dye  extracts,  and  solution  of  tin,  vulgarly 
called  spirit  by  dyers.    These  colors  are  brilliant  but  fugitive. 

I.  The  madder  style;  called  by  some  dip  colors.  The  true  chints  patterns  belong  to  it; 
they  have  from  5  to  7  colors,  several  of  which  are  grounded-in  after  the  first  dye  has 
been  given  in  the  madder  bath. 

In  dyeing  with  madder,  sumach,  fustic,  or  quercitron,  is  sometimes  added  to  the  bath, 
in  order  to  produce  a  variety  of  tints  with  the  various  mordants  at  one  operation. 

1.  Suppose  we  wish  to  produce  flowers  or  figures  of  any  kind  containing  red,  purpl^ 
and  black  colors,  we  may  apply  the  three  mordants  at  once,  by  the  three-color  cylinder 
machine,  putting  into  the  first  trough  acetate  of  alumina  thickened ;  into  the  second,  ace- 
tate of  iron ;  and  into  the  third,  a  mixture  of  the  two ;  then  drying  in  the  air  for  a  few 
days  to  fix  the  iron,  dunging  and  dyeing  up  in  a  bath  of  madder  and  sumach.  If  we  wish 
to  procure  the  finest  madder  reds  and  pinks,  besides  the  purple  and  black,  we  must  apply 
at  first  only  the  acetate  of  alumina  of  two  densities,  by  two  cylinders,  dry,  dun?,  and  dye 
up,  in  a  madder  bath.  The  mordants  of  iron  liquor  for  the  black,  and  of  iron  liquor 
mixed  with  the  aluminous  for  purple,  must  be  now  grounded-in  by  blocks,  taking  care  to 
insert  these  mordants  into  their  precise  spots :  the  goods  being  then  dried  with  airing  for 
several  days,  and  next  dunged,  are  dyed  up  in  a  bath  of  madder  and  sumach.  They  must 
be  afler^vards  cleared  by  branning.     See  Bran,  Dunging,  and  Madder. 

2.  Suppose  we  wish  to  produce  yellow  with  red,  pink,  purple,  and  black ;  in  this  case 
the  second  dye-bath  should  contain  quercitron  or  fustic,  and  the  spots  intended  to  be  yel- 
low should  receive  the  acetate  of  alumina  mordant. 

3.  The  mordant  for  a  full  red  may  be  acetate  of  alumina,  of  spec.  grav.  1*055,  thickened 
with  starch,  and  tinged  with  Brazil-wood ;  that  for  a  pale  red  or  pink,  the  same  at  spec, 
gravity  1-014,  thickened  with  gum;  that  for  a  middling  red,  the  same  at  spec,  gravity 
1-027,  thickened  with  British  gum ;  and  for  distinction's  sake,  it  may  be  tinged  yellow 
With  Persian  berries.  The  mordant  for  black  is  a  pyroligneous  acetate  of  iron,  of  specific 
gravity  1-04;  for  purple  the  same,  diluted  with  six  times  its  volume  of  water;  for 
chocolate,  that  iron  liquor  mixed  with  acetate  of  alumina,  in  various  proportions  accord- 
ing to  the  shade  wanted.  Sumach  is  mixed  with  the  madder  for  all  these  colors  except  for 
the  purple.  The  quantity  of  madder  required  varies  according  to  the  body  of  color  to  be 
put  upon  the  cloth,  being  from  one  pound  per  piece  to  three  or  even  four.  The  ffoods 
must  be  entered  when  the  copper  is  cool,  be  gradually  heated  during  two  or  three  hours, 
up  to  ebullition,  and  sometimes  boiled  for  a  quarter  of  an  hour;  the  pieces  being  all  the 
wmie  turned  with  a  wince  from  the  one  side  of  the  copper  to  the  other.  (See  Wince.) 
iney  are  then  washed  and  boiled  in  bran  and  water  for  ten  or  fifteen  minutes.  Whea 
inere  is  much  white  ground  in  the  chints,  they  must  be  branned  a  second  or  even  a  thii-^ 
thpv'  ^  alternate  washing  in  the  dash-wheel.  To  complete  the  purification  of  the  while, 
iinnH  %^/'?.  "P*'"  ^^^  ^'■ass  for  a  few  days  ;  or  what  is  more  expeditious,  and  equally 
gooQ  u  delicately  managed,  they  are  winced  for  a  few  minutes  in  a  weak  solution  of 
cnioride  of  lime. 

4.  Ill  the  gronnding-in  for  yellow,  after  madder  reds,  the  aluminous  mordant  being 


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CALICO-PRINTING. 


applied,  &c.,  the  piece  is  dyed,  for  about  an  hour,  with  one  pound  of  quercitron  bark, 
the  infusion  being  gradually  heated  to  150°  or  160°,  but  not  higher. 

5.  A  yellow  is  sometimes  applied  in  chints  work  after  the  other  colors  are  dyed,  bj 
means  of  a  decoction  of  Persian  berries  mixed  with  the  aluminous  mordant,  thickened 
with  flour  or  gum,  and  printed-on  with  the  block;  the  piece,  when  dry,  is  passed 
through  a  weak  carbonated  alkaline  water,  or  lime  water,  then  washed  and  dried  for 
the  market. 

6.  Black  mordant. — Take  half  a  gallon  of  acetate  of  iron,  of  spec.  grav.  1*04,4  ounces 
of  starch,  and  4  ounces  of  flour.  The  starch  must  first  be  moistened  with  the  acetate, 
then  the  flour  must  be  added,  the  rest  of  the  acetate  well  mixed  with  both,  and  the 
whole  made  to  boil  over  a  brisk  fire  for  five  minutes,  stirring  meanwhile  to  prevent  adhe- 
sion to  the  bottom  of  the  pot.  The  color  must  be  poured  into  an  earthen  pipkin,  and 
well  mixed  with  half  an  ounce  of  gallipoli  oil.  In  general,  all  the  mordants,  thickened 
with  starch  and  flour,  must  be  boiled  for  a  few  minutes.  With  British  gum  or  common 
gum,  they  must  be  heated  to  160°  F.,  or  thereby,  for  the  purpose  merely  of  dissolving 
them.  The  latter  should  be  passed  through  a  sieve  to  separate  the  impurities  often 
present  in  common  gum. 

7.  Puce  mordant. — Take  a  quart  of  acetate  of  alumina  and  acetate  of  iron,  each  of 
spec.  grav.  1-04,  mixed  and  thickened  like  the  blac*lf.  No.  6.  To  give  the  puce  a  reddish 
tinge,  the  acetate  of  alumina  should  have  a  specific  gravity  of  1'048,  and  the  iron  liquor 
only  1-007. 

Red  mordants  are  thickened  with  British  gum,  and  are  sufl5ciently  colored  with  the 
addition  of  any  tinging  decoction. 

8.  Violet  mordants. — These  consist  either  of  a  very  weak  solution  of  acetate  of  iron, 
of  specific  gravity  1*007,  for  example ;  or  of  a  little  of  the  stronger  acetate  of  1*04, 
mixed  with  acetate  of  alumina,  and  a  little  acetate  of  copper,  thickened  with  starch  or 
British  gum.  The  shades  may  be  indefinitely  varied  by  varying  the  proportions  of  the 
acetates. 

When  black  is  one  of  the  colors  wanted,  its  mordant  is  very  commonly  printed-on 
first,  and  the  goods  are  then  hung  upon  poles  in  the  drj  ing-room,  where  they  are  aired 
for  a  few  days,  in  order  to  fix  the  iron  by  its  peroxydizement ;  the  mordants  for  red, 
violet,  &,c.,  are  then  grounded  in,  and  the  pieces  are  dyed  up,  after  dunging  and 
washing,  in  the  madder  bath,  into  which,  for  certain  shades,  sumach,  galls,  or  fustic  is 
added.  The  goods  are  brightened  with  a  boil  in  soap  water;  occasionally  also  in  a 
bath,  containing  a  small  quantity  of  solution  of  tin  or  common  salt.  The  following 
mode  of  brightening  is  much  extolled  by  the  French,  who  are  famous  for  their  reds 
and  roses. 

1.  A  soap  boil  of  forty  minutes,  at  the  rate  of  1  pound  for  every  2  pieces.  Rinse  in 
clear  water. 

2.  Pass  through  chloride  of  soda  solution  of  such  strength  that  two  parts  of  it  decolor 
one  part  of  Gay  Lussac's  test  liquor.  See  Chloride  of  Lime  and  Inpigo.  Wince  the 
pieces  through  it  for  40  minutes.     Rinse  again. 

3.  Peiss  it  again  through  the  soap  bath,  No.  1. 

4.  Brigliten  it  in  a  large  bath  of  boiling  water,  containing  4  pounds  of  soap,  and 
1  pound  of  a  cream-consistenced  salt  of  tin,  containing  nearly  half  its  weight  of  the 
muriate  of  tin,  combined  with  as  much  nitric  acid  of  spec.  grav.  1*288.  This  strong 
nitro-muriate  having  been  diluted  with  a  little  water,  is  to  be  slowly  poured  into  the  bath 
of  soap  water,  and  well  nixed  by  stirring.  The  pieces  are  now  put  in,  and  winced 
tnrough  it  for  one  half  or  t'ni-2e  quarters  of  an  hour. 

5.  Repeat  the  soap  boil,  No.  1.    Rinse  and  drj'. 

9.  Grounding-in  of  Indigo  blue. 

Take  half  a  gallon  of  water  of  120°  F.,  8  ounces  of  ground  indigo,  and  8  ounces 
of  red  sulphuret  of  arsenic  (orpiment),  8  ounces  of  quicklime,  mix  together,  and  heat 
the  mixture  to  the  boiling  point;  withdraw  from  the  fire,  and  add,  when  it  is  lukewarm, 
6  ounces  of  carbonate  of  soda,  stir  and  leave  the  whole  at  rest  till  the  next  day.  Then 
decant  the  clear  liquor,  and  thicken  every  quart  of  it  with  half  a  pound  of  gum.  This 
color  ought  to  be  green,  and  be  preserved  in  a  close  vessel.  When  used,  it  is  put  into  a 
pot  with  a  narrow  orifice,  the  pencil  is  dipped  into  it,  wiped  on  the  edge  of  the  pot,  and 
immediately  applied  by  hand.  This  plan  is  tedious,  and  is  nearly  superseded  by  the  fol- 
lowing grounding  blue. 

Take  half  a  gallon  of  caustic  soda  ley  of  spec.  grav.  M5,  heated  to  120°  F. 

12  ounces  of  hydrate  of  protoxyde  of  tin,  obtained  by  precipitating  it  from  the  muriate 
of  tin  by  solution  of  potash. 

8  ounces  of  ground  indigo ;  heat  these  mixed  ingredients  to  the  boiling  point,  then 
move  the  pot  off  and  on  the  fire  two  or  three  times  in  succession,  and  finally  thicken 
with  3  pounds  of  raw  sugar.  In  order  to  apply  this  by  the  block,  the  following  ap- 
paratus is  employed,  called  the  canvass  frame;  figs.  299,300.    It  is  formed  of  a  copper 


, ) 


\ 


CALICO-PRINTING. 


321 


ease  or  box  A,  in  which  is  laid  a  frame  b,  filled  with  pretty  stout  canvass  The  box 
communicates  by  a  tube  with  the  cistern  c,  mounted  with  a  stop-cock  d.  Fig.  300 
represents  the  apparatus  in  plan  :  a,  the  box ;  b,  the  canvass,  with  its  edses  a  a  a  a, 
fixed  by  pin  points  to  the  sides.  The  color  is  ieared  (tire),  or  spread  even,  with  a 
wooden  scraper  as  broad  as  the  canvass.  In  working  with  this  apparatus,  the  color 
being  contained  in  the  vessel  c  is  drawn  oflT  into  the  case  a,  by  opening  the  stop-cock  d, 
till  it  rises  to  the  level  of  the  canvass.  The  instant  before  the  printer  daubs  the  block 
upon  the  canvass,  the  tearer  (tireur),  boy  or  girl,  runs  the  scraper  across  it  to  renew  its 
surface ;  and  the  printer  immediately  transfers  the  color  to  the  cloth.  In  this  kind  of 
printing  great  skill  is  required  to  give  evenly  impressions.  As  the  blue  is  usually  applied 
to  somewhat  large  designs,  it  is  very  apt  to  run ;  an  inconvenience  counteracted  by  dust- 
ing: fine  dry  sand  upon  the  cloth  as  soon  as  it  is  blocked.  The  goods  must  be  washed 
within  24  hours  after  being  printed. 

10.  Topical  grounding  blue  for  the  cylinder  press. 
Take  3|  gallons  of  caustic  soda  ley  of  spec.  grav.  1*15. 

3^  lbs.  of  ground  indigo. 

5  lbs.  of  precipitated  protoxyde  of  tin  (as  above). 

Boil  the  mixed  ingredients  for  ten  minutes,  take  them  from  the  fire,  and  add,  first, 
3  lbs.  of  Venice  turpentine ;  then  1 1  lbs.  of  gum. 

Put  this  mixture  into  the  color  trough,  print  with  it,  and  after  two  days  wash  in  the 
dash-wheel ;  then  pass  it  through  a  soap-bath,  along  with  a  little  soda,  to  brighten  the 
blue,  and  to  take  off'  its  grayish  tint. 

The  use  of  the  turpentine  is  easily  explained;  it  serves  to  exclude  the  atmospherical 
oxygen,  and  prevent  the  regeneration  of  the  indigo  blue,  before  it  is  spread  upon  the 
cloth. 

After  the  application  to  white  calico  of  a  similar  blue,  into  which  a  little  acid  muriate 
of  tin  has  been  put,  the  goods  are  dipped  for  ten  minutes  in  thin  milk  of  lime,  shaking 
the  frame  all  the  time.  They  are  then  washed,  and  cleared  with  a  soap  boil.  The  fol- 
lowing color  remains  long  in  the  deoxyuized  slate  from  its  containing  8  ounces  of  indigo, 
10  ounces  of  hydraled  protoxyde  of  tin,  and  I|  pounds  of  solution  of  muriate  of  tin,  to  2 
quarts  of  soda  ley  of  1*15,  thickened  with  2|  pounds  of  gum.  This  blue  may  be  applied 
by  either  the  block  or  the  cylinder. 

11.  Topical  Prussian  blue  for  grounding. 

2  quarts  of  water  with  8  ounces  of  starch  are  to  be  mixed  and  boiled ;  add  2|  ounces 
of  a  liquid  Prussian  blue  color,  prepared  by  triturating  three  quarters  of  an  ounce  of  that 
pigment  with  as  much  muriatic  acid,  leaving  the  ingredients  to  react  upon  each  other  for 
24  hours,  and  then  adding  three  quarters  of  an  ounce  of  water. 

Ad  ]  4  ounces  of  liquid  perchloride  of  tin  (oxymuriateX 

Mix  all  together,  and  pass  through  a  scarce.  This  color  is  not  very  fast ;  cloth  printed 
With  it  will  bear  only  rinsing. 

12.  Prussian  blue  figures  are  impressed  as  follows : — 

Dissolve  8  ounces  of  sulphate  of  iron,  and  as  much  acetate  of  lead,  separately  in  2 
quarts  of  boiling  water ;  mix  well,  and  settle.  Take  one  quart  of  this  clear  liquor  re- 
duced to  spec.  grav.  1*02,  one  quart  of  mucilage  containing  3  pounds  of  gum,  colored  with 
a  little  prussiate  of  potash,  mix  into  a  mordant,  and  print  it  on  with  the  cylinder.  Two 
days  afterwards  wash  in  tepid  water  containing  a  little  chalk,  and  then  pass  the  cloth 
through  a  solution  of  prussiate  of  potash  in  water,  sharpened  with  a  little  muriatic  acid, 
mi  It  takes  the  desired  hue.     Finally  rinse. 

II.  The  padding  or  plaquage  style,  called /ott/ard  also  by  the  French.     See  Padding. 

Any  mordant  whatever,  such  as  the  acetates  of  alumina,  or  of  iron,  or  their  mixture, 
"»ay  be  applied  to  the  piece  by  the  padding  machine,  after  which  it  is  dried  in  the  hot 
FLUF  washed,  dunged,  dyed,  washed,  and  brightened. 

.j.p'?     \""T  J^eta"ic  oxydes  are  very  elegantly  applied  by  the  padding  process.     Thuf 
«ie  iron  puft,  the  manganese  bronze,  and  the  chrome  yellows  and  greens  are  given. 

i.  Iron  bufl^  or  chamois. 
*  ake  50  gallons  of  boiling  water ; 

150  pounds  of  sulphate  of  iron ;  dissolve  along  with 
10  pounds  of  alum ;  which  partly  saturate  by  the  gradual  addition  of 
o  pounds  of  crystals  of  soda;  and  in  this  mixture^dissolve 


I 


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CALICO-PRINTING. 


• 

50  pounds  of  pyroligneous  acetate  of  lead.    Allow  the  whole  to  settle,  and  draw  ofl'  tho 
clear  supernatant  liquid. 

For  furniture  prints  this  bath  should  have  the  spec.  grav.  1*07. 

The  calico  being  padded  in  it,  is  to  be  dried  in  the  hot-flue  ;  and  after  48  hours  suspen- 
sion is  to  be  washed  in  water  at  HOP  containing  some  chalk,  by  the  wince  apparatus.  It 
is  then  washed,  by  the  same  apparatus,  in  hot  water,  containing  a  pailful  of  soda  ley  of 
speo.  grav.  1*04. 

For  light  tints  the  padding  liquor  should  be  rediiced  to  the  spec.  grav.  1-01.  The 
'<ye  in  either  case  may  be  brightened  by  wincing  througJi  a  weak  solution  of  chloride  of 
lime. 

Nitrate  of  iron  diffused  through  a  body  of  water  may  be  also  used  for  padding,  with 
alternate  washings  in  water,  and  a  final  wincing  in  a  weak  alkaline  ley. 

With  a  stronger  solution,  similar  to  the  first,  the  boot-top  color  is  given. 
^  2.  The  bronze  or  solitaire. 

The  goods  are  to  be  padded  in  a  solution  of  the  sulphate  or  muriate  of  manganese,  of 
a  strength  proportional  to  the  shade  desired,  dried  in  the  hot-flue,  and  then  raised  by 
wincing  them  io  a  boiling-hot  caustic  ley,  of  spec.  grav.  1-08,  and  next  through  a  weak 
solution  of  chloride  of  lime,  or  soda.  They  are  afterwards  rinsed.  Instead  of  passing 
them  through  the  chloride,  they  may  be  merely  exposed  to  the  air  till  vhe  manganese  at- 
tracts oxygen,  then  rinsed  and  dried. 

When  the  manganese  solution  has  the  density  of  1-027,  it  gives  a  light  shade  j  at  the 
density  of  1-06,  a  shade  of  moderate  depth,  and  at  1*12  a  dark  tint. 

The  texture  of  the  stuff  is  apt  to  be  injured  during  the  oxydation  of  the  manganese. 

3.  Carmelite  is  obtained  by  padding  in  a  mixture  of  muriate  or  sulphate  of  manganese 
and  acetate  of  iron,  then  proceeding  as  above. 

4.  Copper  green  is  given  by  padding  in  a  mixed  solution  of  sulphate  and  acetate  of 
copper  with  a  little  glue,  drying  in  the  hot-flue,  and  next  day  padding  in  a  caustic  ley  of 
spec.  grav.  1-05.  The  goods  are  then  rinsed,  and  padded  through  a  solution  made  with  8 
ounces  of  arsenions  acid  combined  with  4  ounces  of  potash  diluted  with  2  gallons  oi'  wa- 
ter.    They  are  finally  rinsed  and  dried. 

5.  Olive  and  cinnamon  colors  are  given  by  padding  through  mixed  solutions  of  the 
acetate  of  iron  and  sulphate  of  copper ;  drying,  and  padding  in  a  caustic  ley  of  spec 
grav.  1-05. 

6.  Green  and  solitaire  form  a  pleasing  umber,  or  hellebore  shade,  which  may  be  ob- 
tained by  padding  through  a  mixed  solution  of  manganese  and  aceto-sulphate  of  copper, 
and  raising  the  shades  as  above  prescribed. 

7.  Chrome  yellow. 

Pad  in  a  solution  of  bichromate  of  potash  containing  8  ounces  of  it  to  the  gallon  of  wa- 
ter; then  dry  with  moderate  heat,  and  pad  in  a  solution  of  acetate  or  nitrate  of  lead,  con- 
taining 6  or  8  ounces  in  the  gallon  of  water ;  wash,  and  dry.  Or  we  may  pad  first  in  a 
solution  of  acetate  of  lead  containing  a  liitle  glue ;  dry,  and  pad  in  solution  of  bichro- 
mate of  potash.  Then  rinse.  The  last  process  is  apt  to  occasion  cloudiness.  To  obtain 
a  light  lemon  tint,  we  must  pad  in  a  solution  of  acetate  of  lead  of  double  the  above 
strength,  or  16  ounces  to  the  gallon,  then  wince  the  pieces  through  weak  milk  of  lime, 
rinse,  pad  through  bichromate  of  potash,  rinse  and  dry. 

8.  Chrome  orange. 

Pad  through  a  mixed  solution  of  the  subacetate  and  acetate  of  lead,  three  times  in  sue 
cession,  and  dry  in  the  hot-flue ;  then  wince  for  ten  minutes  through  weak  milk  of  lime; 
rinse ;  wince  for  a  quarter  of  an  hour  in  a  warm  solution  of  bichromate  of  potash ;  and 
finally  raise  the  color  by  wincing  the  goods  through  hot  lime-water. 

9.  Prussian  blue. 

Pad  in  the  preceding  chamois  liquor  of  the  spec.  grav.  1-007;  dry  in  the  hot-flue; 
wince  well  in  chalky  water  at  160°  F.,  and  then  dye  by  wincing  in  the  following 
liquor : — 

Dissolve  5  ounces  of  prussiate  of  potash,  in  25  gallons  of  water  heated  to  90°  or  100®, 
adding  2  ounces  of  sulphuric  acid;  afterwards  rinse,  and  brighten  in  a  very  dilute  sulphu- 
ric acid. 

10.  Green  is  given  by  padding  goods,  previously  dyed  in  the  indigo  vat,  in  a  solution  ol 
acetate  of  lead  contaimng  a  little  glue ;  and  then  padding  them  in  a  warm  solution  of 
bichromate  of  potash ;  finally  rinsing  and  drying. 

III.  Resist  pastes  or  reserves ;  these  are  subservient  to  the  cold  indigo  vat,  and  they 
may  be  distributed  under  four  heads;  1.  fat  reserves;  2.  reserves  with  bases  of  metallie 
salts;  3.  colored  reserves  capable  of  assuming  different  tints  in  the  dyeing;  '4.  reservei 
with  mordants,  for  the  cloth  to  be  afterwards  subjected  to  a  dyeing  bath,  whereby  variously 
colored  figures  are  brought  up  on  a  blue  ground,  so  as  to  resemble  the  mineral  called 
lazulite;  whence  the  name  lapis  or  lapis  lazuli. 

1.  The  fatty  resists  are  employed  in  the  printing  of  silk;  which  see  in/ra. 


CALICO-PRINTING. 


323 


2.  With  regard  to  reserves  the  following  general  observations  may  be  made.  Aftef 
printing-on  the  paste,  the  goods  must  be  hung  up  in  a  chamber,  rather  humid  than  too  dry, 
and  left  there  for  a  certain  time,  more  or  less,  according  to  the  nature  of  the  reserve.  In 
dipping  them  into  the  blue  vat,  if  the  reserve  be  too  dry,  it  is  apt  to  swell,  scale  off,  and 
vitiate  the  pattern.  This  accident  is  liable  to  happen  also  when  the  vat  is  deficient  in 
lime,  especially  with  deep  blues. 

1.  Simple  white  resist  paste  for  a  full  body  of  blue. 
Take  1  gallon  of  water,  in  which  are  to  be  dissolved, 

1  pound  of  binacetate  of  copper  (distiUed  verdigris),  and  3  lbs.   of  sulphate   ot 
copper. 

This  solution  is  to  be  thickened  with 

2  lbs.  of  gum  Senegal,  1  lb.  of  British  gum,  and  4  lbs.  of  pipe-clay;  adding  after 
wards,  2  ounces  of  nitrate  of  copper— as  a  deliquescent  substance. 

2.  White  reserve  for  light  blues. 

Take  1  gallon  of  -water,  in  which  dissolve 
4  ounces  of  binacetate  of  copper, 

1  lb.  of  sulphate  of  copper;  and  thicken  this  solution  with 

2  lbs.  of  gum  Senegal,  1  lb.  of  British  gum,  and  4  lbs.  of  pipe-clay. 

3.  White  reserve  for  the  cylinder  machine. 
Take  I^  gallons  of  water;  in  which  dissolve 

2|  lbs.  of  binacetate  of  copper, 

10  lbs.  of  sulphate  of  copper ;  and  add  to  the  solution 

6  lbs.  of  acetate  of  lead ;  then  thicken  with 

10  lbs.  of  gum ;  adding  afterwards  10  lbs.  of  sulphate  of  lead. 
After  printing-on  this  reserve,  the  goods  are  to  be  hung  up  for  two  days,  then  dipped 
till  the  proper  blue  tint  be  obtained.    Finally  they  must  be  winced  through  dilute  sulphu- 
ric acid  to  clearr  up  the  white,  by  removing  the  cupreous  tinge. 

3.  Colored  reserves. 

1.  Chamois  reserve. 

Take  1  gallon  of  the  chamois  bath  (No.  1,  page  232,  at  bottom) ;  to  which  add 

8  ounces  of  nitrate  of  copper, 

24  ditto  of  muriate  of  zinc ;  thicken  with 

6  pounds  of  pipe-clay,  and  3  pounds  of  gum  Senegal. 
After  printing-on  this  paste,  the  goods  must  be  hung  up  for  five  or  six  days  in  a  some- 
what  damp  room.     Then  after  having  dipped  them  in  the  vat,  they  are  to  be  steeped  in 
water  for  half  an  hour,  and  slightly  washed.    Next  wince  for  half  an  hour,  through  water 
at  100°  F.  containing  2  pounds  of  soda  crystals  per  30  gallons.    Rinse  and  dry. 

2.  Chrome  yellow  reserve. 

Take  1  gallon  of  water ;  in  which  dissolve 

3  lbs.  of  nitrate  of  lead, 

1  lb.  of  binacetate  of  copper ;  to  the  solution,  add 

I  lb.  of  subacetate  of  lead ;  and  thicken  the  mixed  solution  with 

3  lbs.  of  gum. 

6  lbs.  of  pipe-clay.     Grind  all  the  ingredients  together,  and  pass  through  a  scarce. 
After  treating  the  goods  as  in  No.  1,  they  must  be  winced  for  half  an  hour  in  a  solution 
containing  5  ounces  of  bicliromate  of  potash,  per  piece  of  calico,  and  also  in  a  dilute 
muriatic  bath,  till  the  clirome  yellow  becomes  sufficiently  bright. 

A  chrome  orange  reserve  may  be  made  by  introducing  a  larger  proportion  of  subacetate 
of  lead,  and  passing  the  reserve  printed  goods  through  weak  milk  of  lime,  as  already  pre- 
•cribed  for  producing  an  orange  by  chrome. 

The  basis  of  the  resist  pastes  used  at  Manchester  is  sometimes  of  more  complex  com- 
position than  the  above ;  since,  according  to  the  private  information  I  received  from  an 
extensive  calico  printer,  they  contain  china  clay  (instead  of  pipe-clay,  which  often  con- 
tarns  iron),  strong  solution  of  sulphate  of  copper,  oil,  tallow,  and  soap;  the  whole  incorpo- 
rated by  trituration  with  heat. 

In  the  Lancashire  print-works,  a  Uttle  tartaric  acid  is  added  to  the  nitrate  of  lead, 
"Which  prevents  the  color  from  taking  a  dingy  cast. 

4.  Reserves  with  mordants,  or  the  lazulite  style. 
1.  Black  upon  a  blue  ground. 

At  Manchester  the  black  pattern  is  printed-on  with  a  mixture  of  iron  liquor  and  extract 
01  logwood,  and  the  resist  paste  by  the  cylinder  machine ;  in  France  the  black  is  given 
oy  the  following  recipe : — 

Take  1  gallon  of  decoction  of  gaUs  of  spec.  grav.  1-04,  mixed  and  boiled  into  a  paste  with 
14  ounces  of  flour;  into  the  paste,  when  neariy  cold,  there  are  added, 
8  ounces  of  an  acetated  peroxyde  of  iron,  made  by  adding  1  lb.  acetate  of  lead  to  3 

lbs.  of  nitrate  of  iron,  spec.  grav.  1*56. 
t  ounce  of  gallipoli  oil. 


f 


1 


! 


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CALTCO-PRINTINj. 


325 


\\i 


This  topical  black  forms  a  fast  color,  and  resists  the  fine  blue  vat,  weak  potash  ley 
bichromate  of  potash,  boiling  milk  of  lime,  dunging,  and  maddering. 

The  preceding  answers  best  for  the  block ;  the  following  for  the  cylinder 

2.  Take  1  gallon  decoction  of  galls  of  spec.  grav.  1*056.  * 

18  ounces  of  flour,  mix,  boil  into  a  paste,  to  which,  when  cool,  add 
8  ounces  of  the  aceto-nitrate  ofiron  of  the  preceding  formula,  and 
1  quart  ofiron  liquor  of  spec.  grav.  I'llO. 

In  Lancashire  a  litile  prussiate  of  potash  is  sometimes  added  to  nitrate  of  iron  and 
decoction  of  logwood;  and  the  goods  are  after  washing,  &c.  finished  by  passin"  throu<'h 
a  weak  solution  of  bichromate  of  potash.  The  chromic  acid  gives  depth  and  permanence 
to  the  black  dye,  being  supposed  to  impart  oxygen  to  the  iron,  while  it  does  not  affect 
any  of  the  other  colors  that  may  happen  to  be  impressed  upon  the  cloth,  as  solution  of 
chloride  of  lime  would  be  apt  to  do.  The  solution  of  the  bichromate  deepens  the  spirit 
purples  into  blacks,  and  therefore  with  such  delicate  dyes  becomes  a  very  valuable  appli- 
cation. Ihis  interesting  fact  was  communicated  to  me  by  an  eminent  calico-printer  in 
Lancashire.  ^ 

Having  premised  the  composition  of  the  topical  black  dye,  we  are  now  prepared  to 
apply  It  m  the  lazulite  style. 

1.  Black  resist. 

Take  1  gallon  of  the  above  black  without  the  flour, 
2  ounces  of  sulphate  of  copper, 

1  ounce  of  muriate  of  ammonia,  dissolve  and  thicken  with 
4  pounds  of  pipe-clay  and  2  pounds  of  gum. 

Another  good  formula  is  the  following : — 
Take  1  gallon  ofiron  liquor  of  1-056  spec.  grav. ;  dissolve  in  it, 

2  ounces  of  binacetate  of  copper, 

8  ounces  of  sulphate  of  copper ;  and  thicken  as  just  described. 

2.  Puce,  reserve  paste,  contains  acetate  of  alumina  mixed  with  the  iron  liquor. 

3.  Full  red  reserve. 

Take  1  gallon  of  acetate  of  alumina,  (made  with  50  gaUons  water,  100  lbs.  alum,  10  lbs. 
soda  crystals,  and  100  lbs.  acetate  of  lead ;  the  supernatant  liquid  being  of  spec, 
grav.  1-085;)  dissolve  in  it  *^ 

4  ounces  of  corrosive  sublimate ;  thicken  with 

2  pounds  of  gum  Senegal, 

4  pounds  of  pipe-clay,  and  mix  in  8  ounces  of  gallipoli  oil. 

4.  Reserve  paste /or  a  light  red. 

Take  1  gallon  of  the  weaker  sulpho-acetate  of  alumina  formerly  prescribed;  dissolve  in  it 
4  ounces  of  corrosive  sublimate ;  and  thicken  with 
4  pounds  of  pipe-clay,  and  2  pounds  of  gum  j  adding  to  the  mixture 
8  ounces  of  oil. 

5.  Neutral  resist  paste. 

Take  1  gallon  of  water;  in  which  dissolve, 

3  J  lbs.  of  binarseniate  of  potash,  and 

12  ounces  of  corrosive  sublimate ;  thicken  with 

3  lbs.  of  gum,  and  6  lbs.  of  pipe-clay,  adding  to  the  paste  16  ounces  of  oil. 

6.  Carmelite  reserve  paste. 

Take  1  half  gallon  of  acetate  of  alumina,  spec.  grav.  1-014;  (see  second  aluminous  mor- 
dant,  p.  230.) 

1  half  gallon  iron  liquor  of  spec.  grav.  1-027 ;  dissolve  in  them 

4  ounces  of  sulphate  of  copper,  4  ounces  of  verdigris,  and  1  ounce  of  nitrate  of  eo». 
per;  thicken  with  ^^ 

2  lbs.  of  gum, 

4  lbs.  of  pipe-clay. 

7.  Neutral  reserve  paste. 

Take  1  gallon  of  water;  dissolve  in  it, 

44  ounces  of  binarseniate  of  potash,  and 

12  ounces  of  corrosive  sublimate;  thicken  with 

3  lbs.  of  gum, 

6  lbs.  of  pipe-clay, 
16  oz.  of  oil. 
To  explain  fully  the  manipulation  of  the  lazulite  style,  we  shaU  suppose  th«<  tb4  nb. 
eoes  are  printed  with  the  following  reserves,  taken  in  their  order :— 

1.  Black  reserve.         No.  1.  above. 

2.  Full  red  reserve,      No.  3. 

3.  Light  red  reserve,    No.  4, 

4.  Neutral  reserve,       No.  7. 

Four  days  after  printing-on  these  reserves,  the  goods  must  be  twice  dipped  ia  thf  Um 


K 


rat,  ten  minutes  in  and  ten  minutes  out  each  time ;  but  more  dips  may  be  given  accord, 
ing  to  the  desired  depth  of  the  shade.  The  cloth  must  be  afterwards  rinsed  in  running 
water  for  half  an  hour.  The  next  process  is  to  remove  the  paste ;  which  is  done  by  winc- 
ing the  goods  in  a  bran  bath,  lowered  to  150°,  during  twenty  minutes.  They  are  then 
winced  for  five  minutes  in  a  bath  of  water  slightly  sharpened  with  vinegar.  When  well 
cleansed  they  are  ready  for  the  madder  bath.  The  lapis  goods  are  finally  cleared  in  a 
bran  bath,  by  exposure  on  the  grass,  and  a  soap  boil. 
The  lazulite  style  is  susceptible  of  many  modifications. 

8.  Deep  blue  ground,  with  light  blue,  carmelite,  and  white  figures. 

1.  Print-on  the  white  reserve,  No.  1. 

2.  Dip  in  the  strongesc  blue  vat ;  rinse  and  dry. 

3.  Ground-in  with  the  block,  the  carmelite  reserve  (containing  the  mixed  acetates 
of  iron  and  alumina.) 

4.  Ground-in  the  neutral  reserve. 
V  Dip  for  the  light  blue ;  rinse. 
6.  Dung,  dye,  and  clear,  as  above. 

By  varying  the  proportions  of  the  reserve  mordants,  and  the  dye-stufifs,  as  madd»^ 
quercitron,  &c.  a  great  variety  of  effects  may  be  produced. 

9.  Deep  green  ground,  with  buff  and  white  figures. 

1.  Print-on  the  white  reserve. 

2.  Dip  in  the  blue  vat ;  rinse  and  dry. 

3.  Pad  in  the  buff  liquor,  as  formerly  prescribed. 

4.  Ground  in  upon  the  buff  spots,  the  discharge  No.  2,  presently  to  be  described. 

5.  Wash  away  the  paste  in  chalky  water. 

6.  Wince  through  a  boiling  alkaline  ley,  to  raise  the  buff  iron  color. 
rV.  The  Discharge  style ;  first,  of  simple  discharges. 

1.  Discharge  for  block  printing. 

Take  1  gallon  of  lemon  or  lime-juice,  of  spec.  grav.  1-09,  in  which  dissolve 
1  pound  of  tartaric  acid, 

1  pound  of  oxalic  acid,  and  thicken  the  solution  with 

4  pounds  of  pipe  or  china  clay,  and  2  pounds  of  pulverized  gum ;  as  soon  as  the 
gum  is  dissolved,  the  mixture  must  be  put  through  a  scarce. 

2.  Another  discharge  is  made  of  half  the  above  acid  strength. 

3.  A  third  with  one  half  of  the  solid  acids  of  the  second. 

4.  Take  1  gallon  of  water,  in  which  dissolve  with  heat 

1  pound  of  cream  of  tartar,  adding,  to  facilitate  the  solution, 

1  pound  of  warm  sulphuric  acid  of  spec.  grav.  1*7674 ;  after  24  hours  mix 

4  lbs.  of  pipe  or  China  clay,  and  three  lbs.  of  gum,  with  the  decanted  clear  liqnot. 

In  some  cases  British  gum  is  used  alone,  as  a  thickener. 

5.  Discharge  for  the  cylinder  machine. 

Take  1  gallon  of  lime-juice,  of  spec.  grav.  1*085 ;  dissolve  in  it 

3  pounds  of  tartaric  acid,  and  one  pound  of  oxalic  acid ;  thicken  with 
6  pounds  of  gum  Senegal,  or  5  pounds  of  British  gum. 

6.  7.  A  stronger  and  weaker  discharge  is  made  of  the  same  materials ;  and  one  is  made 

without  the  tartaric  acid. 

Second ;  combination  of  discharges  with  mordants. 

1.  Black,  red,  lilach,  and  white  figures  upon  an  olive  ground. 

The  olive  being  given  in  a  madder  bath,  and  the  ground  well  whitened  (see  Madder), 
the  cloth  is  padded  in  a  weak  buff  mordant ;  and  upon  the  parts  that  are  to  remain  white, 
the  weakest  simple  discharge  No.  3  is  printed-on  by  the  cylinder ;  (in  some  works  the  dis- 
chai^e  paste  is  applied  and  made  dr^'  before  padding  through  the  iron  liquor;)  the  goods 
are  cleared  of  the  paste  in  a  tepid  chalky  water,  then  dyed  in  a  quercitron  bath,  contain- 
ing a  little  glue,  and  cleared  in  a  bran  bath. 

Discharge  mordants  upon  mordants  may  be  regarded  as  a  beautiful  modification  of  the 
preceding  style.    Example. 

*A  violet  ground  or  impression,  with  red  and  white. 

1.  Pad  with  an  acetate  of  iron  of  1*004 ;  or  print-on  with  the  cylinder,  iron  liquor  of 
1*027  thickened  with  British  gum. 

2.  Print-on  a  red  mordant,  strongly  acidulated  with  lime-juice  of  1*226. 

3.  Ground  in  the  discharge  No.  2 ;  dry. 

4.  Clear  off  the  paste  in  chalky  water. 

5.  Dung,  madder,  and  brighten. 

6.  Ground-in  the  topical  colors  at  pleasure. 
V.  China  blues. 

Take  16  pounds  of  coarsely  ground  indigo,  and 

4  pounds  of  sulphuret  of  arsenic;  dissolve  22  pounds  of  sulphate  of  iron  in  6 
fallons  of  water ;  introduce  these  three  matters  into  the  indigo  mill,  and  grind  them  for 


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326 


CALICO-PRINTING. 


three  days.  If  it  be  wished  to  have  a  thickened  blue,  this  mixture  must  have  pourvdew 
gum  added  to  it  j  but  if  not,  5  gallons  of  water  are  added.  This  color  may  be  called 
talue  No.  1. 

The  following  table  exhibits  the  different  gradations  of  China  blue : — 


1 

ConrM. 

Quantity  by  measure  of 

Quantity  by  measure  of 

No.  1. 

water  or  mucilage. 

No.  1 

1 

0 

2 

11 

1 

3 

10 

2 

4 

8 

4 

5 

6 

6 

6 

4 

8 

7 

2 

10 

8 

2 

12 

9 

2 

14 

10 

2 

16 

11 

2 

18 

12 

2 

20 

I  shall  now  give  examples  of  working  this  style  by  the  block  and  cylinder  i— 

(mpression  of  a  single  blue  with  small  dots. 

For  the  block,  blue  No.  5,  thickened  with  starch. 

For  the  cylinder.  No.  4,  thickened  with  gum. 

Impression  of  two  different  blues  with  tht  block. 

First  blue,  No.  4,  with  starch. 

Second  blue,  No.  9,  with  gum. 

Impression  of  three  blues  with  the  block. 

First  blue,  No.  5,  with  starch. 

Second  blue.  No.  7,  with  starch. 

Third  blue.  No.  10,  with  gum. 

After  printing-on  the  blues,  the  pieces  are  hung  up  for  two  days,  in  a  dry  and  airy 
place,  but  not  too  dry ;  then  they  are  dipped  as  follows  : — ^Three  vats  are  mounted,  whicb 
may  be  distinguished  by  the  numbers  1,  2,  3. 

No.  1.  300  pounds  of  lime  to  1,800  gallons  of  water. 

No.  2.  Solution  of  sulphate  of  iron  of  spec.  grav.  1'048. 

3.  Solution  of  caustic  soda  of  spec.  grav.  1*055 ;  made  from  soda  crystals,  quicklime, 
and  water,  as  usual. 

The  pieces  being  suspended  on  the  frames,  are  to  be  dipped  in  the  first  vat,  and  left 
in  it  ten  minutes ;  then  withdrawn,  drained  for  five  minutes ;  next  plunged  into  the 
second  vat  for  ten  minutes,  and  drained  also  for  five,  &c.  These  operations  will  be 
most  intelligible  when  put  into  the  form  of  a  table  :— 

Dip  in  the  1st  vat.       During  10  minutes.         Drain  during  5  minutes. 
2  —  _ 

2  —  Z 

3  —  — 
2                             —                                        — 

2  —  Z 

3  _  Z 

In  the  dipping  of  China  blues,  care  should  be  taken  to  swing  the  frames  during  the 
operation  ;  and  when  the  last  dip  is  given,  the  piece  is  to  be  plunged  upon  its  frame  into 
a  fourth  vat,  containing  dilute  sulphuric  acid  of  spec.  grav.  1-027.  This  immersion  is 
for  the  purpose  of  removing  the  oxyde  of  iron,  deposited  upon  the  calico  in  the  alternate 
passages  through  the  sulphate  of  iron  and  lime  vats.  They  are  then  rinsed  an  hour  in 
running  water,  and  finally  brightened  in  the  above  dilute  sulphuric  acid,  slightly  tepid. 
Sometimes  they  are  subjected  to  a  soap  bath,  at  the  temperature  of  120°.  By  the 
addition  of  nitrate  of  lead  to  the  indigo  vat,  the  blue  becomes  more  lively.  Some  use 
the  roller  dyeing  apparatus  for  running  the  pieces  through  the  respective  baths  instead 
of  the  square  frames.  (See  Wincing.)  But  the  frame-dip  gives  the  most  evenly  dyes, 
and  preserves  the  vats  in  good  condition  for  a  much  longer  time. 


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The  various  phenomena  which  occur  in  the  dipping  of  China  blues  are  not  difficult  ol 
•TnHnition  with  the  lights  of  modern  chemistry.     We  have,  on  the  one  hand,  mdigo 
«ml  sulDhate  of  iron  alternately  applied  to  the  cloth;  by  dipping  it  mto  the  lime,  the 
Hup  is  deoxydized,  because  a  film  of  the  sulphate  of  iron  is  decomposed,  and  protoxide 
nf  iron  comes  forth  to  seize  the  oxygen  of  the  indigo,  to  make  it  yellow-green,  and 
soluble   at  the  same  time,  in  lime-water.    Then,  it  penetrates  mto  the  hea>'t  of  the 
fibres    and,  on  exposure  to  aur,  absorbs  oxygen,  so  as  to  become  msoluble  and  fixed 
within  their  pores.    On  dipping  the  calico  into  the  second  vat  of  sulphate  of  iron,  a 
layer  of  oxyde  is  formed  upon  its  whole  surface,  which  oxyde  exercises  an  action  only 
unon  those  parts  that  are  covered  with  indigo,  and  deoxydizes  a  portion  of  it;   thue 
rendering  a  second  dose  soluble  by  the  intervention  of  the  second  dip  m  the  hme-bath. 
Hence  we  see  that  while  these  alteniale  transitions  go  on,  the  same  series  of  deoxydize- 
ment    «!olution,  and  re-oxydizement  recurs ;  causing  a  progressively  increasing  fixation 
of  indigo  within  the  fibres  of  the  cotton.    A  deposite  of  sulphate  of  lime  and  oxyde  of 
iron  necessarily  falls  upon  the  cloth,  for  which  reason  the  frame  should  be  shaken  in  ti.e 
lime-water  vat,  to  detach  the  sulphate ;  but,  on  the  contrary,  it  should  be  held  motionless 
in  the  copperas  bath,  to  favor  the  deposition  of  as  much  proloxyde  upon  it  as  possible. 
These  circumstances  serve  to  account  for  the  various  accidents  which  sometimes  befall 
the  China  blue  process.    Thus  the  blues  sometimes  scale  off,  which  may  proceed  from  one 
of  two  causes  :— 1.  If  the  goods  are  too  dry  before  being  dipped,  the  color  swells,  and 
comes  off  in  the  vats,  carrying  along  with  it  more  or  less  of  indigo.    2.  If  the  quantity 
of  sulphate  of  lime  formed  upon  the  cloth  be  considerable,  the  crust  will  fall  off,  and 
take  with  it  more  or  less  of  the  blue ;  whence  arise  inequalities  in  the  impression.    The 
influence  of  temperature  is  important ;  when  it  falls  too  low,  the  colors  take  a  gray  cast. 
In  this  case  it  should  be  raised  with  steam.  ,         v       v 

VI.  The  decoloring  or  enlevage  style ;  not  by  the  removal  of  the  mordant,  but  the 
destruction  of  the  dye.  The  acid,  which  is  here  mixed  with  the  discharge  paste,  is 
intended  to  combine  with  the  base  of  the  chloride,  and  set  the  chlorine  free  to  act  upon 
the  color.    Among  the  topical  colors  for  this  style  are  the  following  :— 

1.  Black.— Take  one  gallon  of  iron  liquor  of  spec.  grav.  1*086. 

One  pound  of  starch ;  boil  together,  and  while  the  paste  is  hot,  dissolve  in  it 
One  pound  of  tartaric  acid  in  powder ;  and  when  cold,  add 
Two  pounds  of  Prussian  blue,  prepared  with  muriatic  acid,  see  p.  232. 
Two  ounces  of  lamp  black,  with  four  ounces  of  oil. 

2.  White  discharge,— T^ke  one  gallon  of  water,  in  which  dissolve 

One  pound  and  a  half  of  oxalic  acid, 

Three  pounds  of  tartaric  acid ;  add 

One  gallon  of  lime-juice  of  spec.  grav.  1'22;  and  thicken  with 

Twelve  pounds  of  pipe  clay,  and  six  pounds  of  gum. 

a.  Chf>me-green  discharge. —  .  ,     «  *    *      u 

Take  one  gallon  of  water,  thicken  with  18  ounces  of  starch ; 

boil  and  dissolve  in  the  hot  paste ; 
Two  pounds  and  a  half  of  powdered  nitrate  of  lead. 
One  pound  and  a  half  of  tartaric  acid. 
Two  pounds  of  Prussian  blue,  as  above. 
4.  Blue  discharge.— Take  one  gallon  of  water,  thicken  with 

18  ounces  of  gum  ;  while  the  boiled  paste  is  hot,  dissolve  in  it 
Two  pounds  of  tartaric  acid,  and  mix  one  pound  of  Prussian  blue. 
6.  Chrome-yellow  discharge. — This  is  the  same  as  the  chrome-green  given  above,  but 
without  the  Prussian  blue. 

6.  jS  white  discharge  on  a  blue  ground  requires  the  above  while  discharge  to  be  strength 
ened  with  8  ounces  of  strong  sulphuric  acid,  per  gallon. 

7.  White  discharge  for  Turkey  red  needs  to  be  very  strong. 
Take  one  gallon  of  lime-juice  of  sp.  grav.  1-086 ;  dissolve  in  it 
Five  pounds  of  tartaric  acid  ;  thicken  with 

Eit'ht  pounds  of  pipe-clay,  four  pounds  of  gum ;  then  dissolve  in  the  mixture 
Three  pounds  of  muriate  of  tin  in  crystals ;  and  add,  finally. 
Twenty-four  ounces  of  sulphuric  acid. 

8.  Yellow  discharge  for  Turkey  red. — 

Take  one  gallon  of  lime-juice  of  spec.  grav.  1*086 ;  in  which  dissolve 
Four  pounds  of  tartaric  acid. 

Four  pounds  of  nitrate  of  lead  ;  thicken  the  solution  with 
Six  pounds  of  pipe-clay,  and  three  pounds  of  gum. 
!».  For  green  discharge^  add  to  the  preceding  24  ounces  of  Prussiar  Mue,  as  above. 
The  decoloring   or  chloi-inc  Nath   l«  usually  formed  of  wood  lined  wi»li   lend,  and 
has  an  area  of  about  5  feet  squire,  with  a  de^^th  of  6  Itet.    A  s<iCHie  rramt,  mounted 
with  a  hcrizontal  scries  of  rollers  at  top  and  bottom,  may  be   let   down  by  cords,  at 


■MiHiai 


328 


CALICO-PRINTING. 


CALICO-PRINTING. 


329 


^leasu.-e,  into  the  cistern.     The  pieces  are  introduced  and  guided  in  a  serpentine  path, 
round  the  upper  and  lower  rollers  alternately,  by  a  cord. 

This  bath  is  filled  with  a  solution  of  chloride  of  lime,  of  the  spec.  grav.  1'045,  whos« 
decoloring  strength  is  65°  by  Gay  Lussac's  indigo  chlorometer.  It  ought  to  be  mad« 
turbid  by  stirring  before  putting  in  the  goods,  which  should  occupy  three  minutes  in 
Iheir  passage.  The  piece  is  drawn  through  by  a  pair  of  squeezer  cylinders  at  the  end  of 
the  trough,  opposite  to  that  at  which  the  piece  enters.  With  black,  white,  and  blue 
impressions  of  all  shades,  the  goods  are  floated  in  a  stream  of  water  for  an  hour;  then 
rinsed  and  dried.  When  there  is  yellow  or  green,  the  pieces  must  be  steeped  in  water, 
then  merely  washed  by  the  wince,  and  passed  through  solution  of  bichromate  of  potash, 
containing  from  3  to  5  ounces  of  the  salt  per  piece.  Here  the  pieces  are  winced  during 
15  or  20  minutes,  rinsed,  and  next  passed  through  dilute  muriatic  acid  to  clear  the 
ground ;  then  rinsed  and  dried. 
Discharge  by  the  intervention  of  the  chromic  acid. 

After  having  dipped  the  pieces  to  the  desired  shade,  they  are  padded  in  a  solution  of 
bichromate  of  potash ;  dried  in  the  shade  without  heat ;  and  then  printed  with  the 
following  mordant : — 

Take  1  gallon  of  water;  dissolve  in  it 

2  pounds  of  oxalic  and  1  pound  of  tartaric  acid ;  thicken  with 
6  pounds  of  pipe-clay,  and  3  pounds  of  gum ;  lastly,  add 
8  ounces  of  muriatic  acid. 
After  the  impression,  the  pieces  are  winced  in  chalky  water,  at  120°  F.,  then  washed, 
and  passed  through  a  dilute  sulphuric  acid. 

M.  Daniel  Kcechlin,  of  Mulhausen,  the  author  of  this  very  ingenious  process,  con- 
siders the  action  of  the  bichromate  here  as  being  analogous  to  that  of  the  alkaline  chlo^ 
ndes.  At  the  moment  that  the  block  applies  the  preceding  discharge  to  the  bichromate 
dye,  there  is  a  sudden  decoloration,  and  a  production  of  a  peculiar  odor. 
^  The  pieces  padded  with  the  bichromate  must  be  dried  at  a  moderate  temperature,  and 
in  the  shade.  Whenever  watery  solutions  of  chromate  of  potash  and  tartaric  acid  are 
mixed,  an  effervescence  takes  place,  during  which  the  mixture  possesses  the  power  of 
destroying  vegetable  colors.     This  property  lasts  no  longer  than  the  effervescence. 

VII.  Steam  colors.— Th\s  style  combines  a  degree  of  brilliancy  with  solidity  of 
color,  which  can  hardly  be  obtained  in  any  other  way  except  by  the  chints  dyes. 
The  steam  apparatus  employed  for  fixing  colors  upon  goods,  may  be  distributed  under 
five  heads:— 1.  the  column;  2.  the  lantern;  3.  the  cask;  4.  the  steam-chest ;  and, 
5.  the  chamber. 

The  column  is  what  is  most  generally  used  in  this  country.  It  is  a  hollow  cylin- 
der of  copper,  from  three  to  five  inches  in  diameter,  and  about  44  inches  long,  per- 
forated over  its  whole  surface  with  holes  of  about  one  sixteenth  of  an  inch,  placed 
about  a  quarter  of  an  inch  asunder.  A  circular  plate,  about  9  inches  diameter,  is 
soldered  to  the  lower  end  of  the  column,  destined  to  prevent  the  coil  of  cloth  from 
slidmg  down  off  the  cylinder.  The  lower  end  of  the  column  terminates  in  a  pipe, 
mounted  with  a  stop-cock  for  regulating  the  admission  of  steam  from  the  main  steam- 
boiler  of  the  factory.  In  some  cases,  the  pipe  fixed  to  the  lower  surface  of  the  disc  is 
made  tapering,  and  fits  into  a  conical  socket,  in  a  strong  iron  or  copper  box,  fixed  to  a 
solid  pedestal;  the  steam  pipe  enters  into  one  side  of  that  box,  and  is  provided,  of 
course,  with  a  stop-cock.  The  condensed  water  of  the  column  falls  down  into  that 
chest,  and  may  be  let  off  by  a  descending  tube  and  a  stop-cock.  In  other  forms  of  the 
column,  the  conical  junction  pipe  is  at  its  top,  and  fits  there  into  an  inverted  socket 
connected  with  a  steam  chest,  while  the  bottom  has  a  very  small  tubular  outlet,  so  that 
the  steam  may  be  exposed  to  n  certain  pressure  in  the  column,  when  it  b  incased 
with  cloth. 

The  pieces,  after  being  printed  with  the  topical  colors  presently  to  be  described,  and 
dried,  are  lapped  round  this  column,  but  not  in  immediate  contact  with  it ;  for  the  copper 
cylinder  is  first  enveloped  in  a  few  coils  of  blanket  stuff;  then  with  several  coils  of 
white  calico;  next  with  the  several  pieces  of  the  printed  goods,  stitched  endwise;  and 
lastly.  With  an  outward  iftantle  of  white  calico.  In  the  course  of  the  lapping  and 
anlapping  of  such  a  length  of  webs,  the  cylinder  is  laid  in  a  horizontal  frame,  in  which 
It  is  made  to  revolve.  In  the  act  of  steaming,  however,  it  is  fixed  upright,  by  one  ol 
the  methods  above  described.  The  steaming  lasts  for  20  or  30  minutes,  according  to 
the  nature  of  the  dyes;  those  which  contain  much  solution  of  tin  admit  of  less  steaming. 
Whenever  the  steam  is  shut  off,  the  goods  must  be  immediately  uncoiled,  to  i)revent  the 
chance  of  any  aqueous  condensation.  I  was  much  surprised,  at  first,  on  finding  the 
unrolled  pieces  to  be  free  from  damp,  and  requiring  only  to  be  exposed  for  a  fewminuten 
in  the  air,  to  appear  perfectly  dry.  Weie  water  condensed  during  the  process,  it  would 
be  apt  to  make  the  colors  run. 

Steam  ccljrs  arc  aJ  topical,  though,  for  many  of  them,  the  pieces  ai^  oreT-ooslj 


f 


padded  with  mordants  of  various  kinds.  Some  manufacturers  run  the  goods  before 
printing  them  through  a  weak  solution  of  the  perchloride  of  tin,  with  the  view  of  bright- 
ening all  the  colors  subsequently  applied  or  raised  upon  them.  I  shall  now  illustrate 
steam  calico-printing  by  some  examples,  kindly  furnished  me  by  a  practical  printer  near 
Manchester,  who  conducts  a  great  business  with  remarkable  success. 

Steam  blue. — Prussiate  of  potash,  tartaric  acid,  and  a  little  sulphuric  acid,  are  dis- 
solved in  water,  and  thickened  with  starch;  then  applied  by  the  cylinder,  dried  at  a 
moderate  heat,  and  steamed  for  25  minutes.  They  are  rinsed  and  dried  after  the 
^teaming.  The  tartaric  acid,  at  a  high  temperature,  decomposes  here  a  portion  of  the 
lerrocyanic  acid,  and  fixes  the  remaining  ferrocyanate  of  iron  (Prussian  blue)  in  the  fibre 
of  the  cloth.  The  ground  may  have  been  previously  padded  and  dyed  ;  the  acids  will 
remove  the  mordant  from  the  points  to  which  the  above  paste  has  been  applied,  and 
bring  out  a  bright  blue  upon  them. 

Steam  purple. — This  topical  color  is  made  by  digesting  acetate  of  alumina  upon  ground 
logwood  with  heat ;  straining,  thickening  with  gum  Senegal,  and  applying  the  paste  by 
the  cylinder  machine. 

Steam  pink. — A  decoction  of  Brazil-wood  with  a  small  quantity  of  the  solution  of 
muriate  of  tin,  called,  at  Manchester,  new  tin  crystals,*  and  a  little  nitrate  of  copper  to 
assist  in  fixing  the  color ;  properly  thickened,  dried,  and  steamed  for  not  more  than  20 
minutes,  on  account  of  the  corrosive  action  of  muriate  of  tin  when  the  heat  is  too  strong. 

Cochineal  pink. — Acetate  of  alumina  is  mixed  with  decoction  of  cochineal,  a  little  tar- 
taric acid  and  solution  of  tin ;  then  thickened  with  starch,  dried,  and  steamed. 

Steam  brown. — A  mixed  infusion  of  logwood,  cochineal,  and  Persian  berries,  with 
cream  of  tartar,  alum  (or  acetate  of  alumina),  and  a  little  tartaric  acid,  thickened,  dried, 
and  steamed* 

Green,  blue,  chocolate,  with  white  ground,  by  steam. — Prussiate  of  potash  and  tartaric 
acid,  thickened,  for  the  blue;  the  same  mixture  with  berry-liquor  and  acetate  of  alumina, 
thickened,  for  the  green ;  extract  of  logwood  with  acetate  of  alumina  and  cream  of 
tartar,  thickened,  for  the  chocolate.  These  three  topical  colors  are  applied  at  once  by 
the  three-color  cylinder  machine ;  dried  and  steamed.  Though  greens  are  fixed  by  the 
steam,  their  color  is  much  improved  by  passing  the  cloth  through  solution  of  bichromate 
of  potash. 

In  France,  solution  of  tin  is  much  used  for  steam  colors. 

VIII.  Spirit  or  fancy  colors. — ^These  all  owe  their  vivacity,  as  well  as  the  moderate 
degree  of  permanency  they  possess,  to  their  tin  mordant.  After  printing-on  the  topical 
color,  the  goods  must  be  dried  at  a  gentle  heat,  and  passed  merely  through  the  rinsing 
machine.  Purple,  brown,  or  chocolate,  red,  green,  yellow,  blue,  and  white  discharge ; 
any  five  of  these  are  printed  on  at  once  by  the  five-color  cylinder  machine.  See  Rinsing 
Machine. 

Chocolate  is  given  by  extract  of  Brazil-wood,  extract  of  logwood,  nitro-muriate  of  tin, 
with  a  little  nitrate  of  copper :  all  mixed,  thickened,  and  merely  printed-on. 

Redf  by  extract  of  Brazil-wood  and  tin,  with  a  little  nitrate  of  copper. 

Green,  by  prussiate  of  potash,  with  muriate  of  tin  and  acetate  of  lead,  dissolved, 
thickened,  and  printed-on. 

The  goods  after  rinsing  must  be  passed  through  solution  of  bichromate  of  potash,  to 
convert  the  Prussian  blue  color  into  green,  by  the  formation  of  chrome  yellow  upon  it. 

Blue. — Prussian  blue  ground  up  with  solution  (nitromuriale)  of  tin ;  thickened,  &c. 

Yellow. — Nitrate  of  lead  dissolved  in  solution  of  tartaric  acid,  thickened,  tenderly 
dried,  passed  through  the  bichromate  vat  or  padding  machine,  washed  and  dried. 

This  yellow  is  pretty  fast ;  though  topical,  it  can  hardly,  therefore,  be  called  a  fancy 
color. 

When  purple  is  to  be  inserted  instead  of  the  above  blue,  extract  of  logwood  with  tin 
is  used  in  the  place  of  the  Prussian  blue.  Tartaric  acid  is  a  useful  addition  to  tin  in 
brightening  fancy  colors.  • 

Chocolate. — A  good  topical  chocolate  is  made  by  digesting  logwood  with  liquid  acetate 
of  alumina,  adding  a  little  cream  of  tartar  to  the  infusion ;  thickening,  applying  by  the 
cylinder,  drying,  washing,  then  passing  through  solution  of  bichromate  of  potash,  which 
serves  to  darken  and  fix  the  color. 

I  shall  conclude  my  account  of  the  printing  of  cotton  goods  with  some  miscellaneous 
formulee,  which  were  given  me  by  skilful  calico-printers  in  Lancashire. 

Prussian  blue  is  prepared  for  topical  printing  by  grinding  it  in  a  handmill,  like  that  for 
grinding  pepper  or  coffee,  and  triturating  the  powder  with  solution  of  muriate  of  tin. 

Green. — ^The  deoxydized  indigo  vat  liquor  is  mixed  with  a  little  pearlash,  and 
thickened  with  gum.    This  is  applied  by  the   cylinder  or  block  to  goods  previously 

*  Thia  preparation  is  made  by  adding  3  lbs.  of  sal  ammoniac  to  I  gallon  of  solution  of  tin  («ee  ScAKLKT 
Dtb,  and  Tin),  fl-vaporatinf,  and  crystallizing.  The  sal  ammoniac  seem*  to  counteiact  the  separation  o: 
the  tin  by  perozydizement. 


330 


CALICO-PRINTING. 


padded  with  nitrate  of  lead ;  the  goods,  after  being  dried,  are  passed  through  milky  lime. 
water,  nnsed,  and  then  winced  or  padded  through  the  bichromate  of  potash  bath. 

Another  green.— Nitrate  of  lead,  prussiate  of  potash,  and  tartaric  acid,  dissolved,  and 
mixed  with  a  little  sulphate,  nitrate,  and  muriate  of  iron ;  this  mixture  is  either  thickened 
for  cylmder  printing,  or  used  in  its  liquid  state  in  the  padding  trough.  The  goods  sub- 
jected to  one  of  these  two  processes  are  dried,  padded  in  weak  solution  of  carbonate  of 
potash,  which  senres  to  precipitate  the  oxyde  of  lead  from  the  nitrate ;  they  are  finally 
padded  with  bichromate  of  potash,  which  induces  a  yellow  upon  the  blue,  conslitutin*'  a 
green  color  of  any  desired  tint,  according  to  the  proportion  of  the  materials.  ° 

Chocolate  and  black,  with  white  discharge;  a  fast  color.— The  cloth  is  padded  with  ace- 
tate of  alumina,  and  dried  in  the  hot-flue ;  it  is  then  passed  through  a  two-color  machine, 
the  one  cylinder  of  which  prints-on  lime-juice  discharge,  thickened  with  gum  seneffah 
the  other  a  black  topical  dye  (made  with  logwood  extract  and  iron  liquor).  The  cloths 
are  now  hung  up  to  be  aired  during  a  week,  after  which  they  are  dunged,  and  dyed  up 
with  madder,  fustic,  and  quercitron  bark,  healed  with  steam  in  the  bath. 

Blue,  white,  and  olive  or  chocolate.— 1.  Pad  with  the  aluminous  mordant:  2.  Apply 
thickened  lemon-juice  for  discharge  by  the  cylinder;  3.  Dung  the  goods  after  they 
are  thoroughly  dried;  4.  Pass  them  through  the  bath  of  madder,  fustic,  and  quercitron, 
which  dye  a  brown  ground,  and  leave  the  discharge  points  white ;  then  print-on  a  reserve 
paste  of  China  clay  and  gum  with  sulphate  of  copper;  dry,  dip  in  the  blue  vat,  which 
will  communicate  an  olive  tint  to  the  brown  ground;  or  a  chocolate,  if  madder  alone  had 
been  used. 

When  a  black  ground  is  desired,  with  white  figures,  the  acid  discharge  paste  should  be 
prmted-on  by  the  cjlinder,  and  dried  before  the  piece  is  padded  in  the  iron  liquor.  Br 
following  this  plan  the  whites  are  much  purer  than  when  the  iron  is  first  applied. 

Green,  black,  white.— The  black  is  first  printed-on  by  a  mixture  of  iron  liquor,  and  in- 
fusion (not  decoction)  of  logwood;  then  resist  or  reserve  paste  is  applied  by  the  block, 
and  dried;  after  which  the  goods  are  blued  in  the  indigo  vat, rinsed, dried,  passed  through 
solution  of  acetate  of  lead;  next,  through  milky  lime-water;  lastly,  throush  a  very  strong 
solution  of  bichromate  of  potash. 

Turkey  red,  black,  yellow.— Upon  Turkey  red  cloth,  print  with  a  strong  solution  of  tar- 
taric acid,  mixed  with  solution  of  nitrate  of  lead,  thickened  with  gum ;  dry.  The  cloth 
IS  now  passed  through  the  chloride  of  lime  bath,  washed,  and  chromed.  Lastly,  the  black 
is  printed-on  by  the  block  as  above,  with  iron  liquor  and  logwood. 

Black  ground  dotted  white,  with  red  or  pink  and  black  fibres.— 1.  Print-on  the 
lime-juice  discharge-paste  by  the  cylinder;  dry;  2.  Then  pad  with  iron  liquor,  con- 
taining a  little  acetate  of  alumina,  and  hang  up  the  goods  for  a  few  days  to  fix 
the  iron ;  3.  Dye  m  a  logwood  bath  to  which  a  little  madder  has  been  added ;  clear 
with  bran.  The  red  or  pink  is  now  put  in  by  the  block,  with  a  mixture  of  extract  of 
Brazil-wood,  nitromuriate  of  tin,  and  nitrate  of  copper,  as  prescribed  in  a  precedine 
formula.  ° 

Orange  or  brown ;  black  ;  white  ;  pink.— The  black  is  topical,  as  above ;  it  is  printed- 
on,  as  also  the  lemon-juice  discharge  and  red  mordant,  with  muriate  of  tin  (both 
thickened),  by  the  three-color  machine.  Then,  after  drying  the  cloth,  a  single-cylinder 
machine  is  made  to  apply  in  diagonal  lines  to  it  a  mixture  of  acetate  of  iron  and  alumina. 
The  cloth,  being  dried  and  dunged,  is  next  dyed  in  a  bath  of  quercitron,  madder,  and 

Here  the  orange  is  the  result  of  the  mordant  of  tin  and  alumina ;  the  brown,  of  the 
alumina  and  iron  ;  white,  of  the  citric  acid  discharge.  The  tin  mordant,  wherever  it  has 
been  applied,  resists  the  weaker  mordant  impressed  in  the  diagonal  lines.  The  pink  is 
blocked-on  at  the  end. 

Orange  brown,  or  aventuHne;  black  and  white.— The  topical  black  (as  above)  and 
discharge  lemon-juice,  are  printed^jn  by  the  two-color  machine ;  then  the  cloth  is  sub- 
jected to  the  diagonal  line  cylinder,  supplied  with  the  alumino-iron  mordant.  The  cloth 
r»  dried,  dunged,  and  dyed  in  a  bath  of  bark,  madder,  and  fustic. 

The  manganese  or  solitaire  ground  admits  of  a  great  variety  of  figures  being  easily 
brought  upon  it,  because  almost  every  acidulous  mordant  will  dissolve  the  oxyde  of 
manganese  from  the  spot  to  which  it  is  applied,  and  insert  its  own  base  in  its  place:  and 
of  course,  by  dyeing  such  mordanted  goods  in  various  baths,  any  variety  of  colored  de- 
signs may  be  produced.  Thus,  if  the  paste  of  nitrate  of  lead  and  tartaric  acid  solution 
be  applied,  and  the  goods  after  drying  be  passed  first  through  lime-water,  and  then 
through  a  chrome  bath,  bright  yellow  spots  will  be  made  to  appear  upon  the  bronze 
ground. 

Manganese  bronze,  buff  and  green;  all  metaUic  colors. —Pad-on  the  manganese 
solution,  and  dry ;  apply  the  aceto-sulphate  of  iron,  of  spec.  grav.  1-02,  and  Scheele's 
green  (both  properly  thickened),  by  the  two-color  machine.  The  goods  are  next  to 
be  dned,  and  padded  through  a  cold  caustic  ley  of  spec.  grav.  1-086.    They  are  then 

16 


CALICO-PRINTING. 


331 


rirtsed,  and  i)assed  through  a  weak  solution  of  chloride  of  lime,  to  raise  the  bronze,  agaii 
rinsed,  and  passed  through  a  solution  of  arsenious  acid  to  raise  the  green. 

Scheele's  green  for  the  calico-printer  is  made  as  follows  : — 

Take  1  gallon  of  water,  in  which  dissolve  with  heat, 

5  pounds  of  sulphate  of  copper,  and  1  pound  of  verdigris.  When  the  two  salts  are  dis- 
solved, remove  the  kettle  from  the  fire,  and  put  into  it  1  quart  of  solution  of  nitrate  of 
copper,  and  5  pounds  of  acetate  of  lead.  Stir  the  mixture  to  facilitate  the  decomposition, 
and  allow  the  pigment  to  subside. 

It  must  be  thickened  with  2i  lbs.  of  gum  per  gallon,  for  pencilling;  or  12  oz.  of  starch 
for  the  block.  The  goods  printed  with  this  paste  are  to  be  winced  through  a  caustic  ley, 
till  a  fine  sky-blue  be  produced ;  then  washed  well  and  rinsed.  They  are  now  to  be 
passed  through  water,  containing  from  half  an  ounce  to  an  ounce  of  white  arsenic  per 
piece ;  4  turns  are  sufficient ;  if  it  be  too  long  immersed  it  will  take  a  yellow  tint. 

Catechu  has  been  considerably  employed  by  calico-printers  of  late  years,  as  it  aflTords  a 
fine  permanent  substantive  brown,  of  the  shade  called  carmelite  by  the  French.  The  fol- 
lowing formula  will  exemplify  its  mode  of  application : — 

Take  1  gallon  of  water ; 

1  pound  of  catechu  in  fine  iwjwder;  reduce  by  boiling  to  half  a  gallon,  pass  the  decoc- 
tion through  a  fine  sieve,  and  dissolve  in  it  4  ounces  of  verdigris ;  allow  it  then  to  cool, 
and  thicken  the  solution  with  5  ounces  of  starch ;  while  the  paste  is  hot,  dissolve  in  it  5 
ounces  of  pulverized  muriate  of  ammonia. 

Print-on  this  paste,  dry,  and  wash.     It  is  a  fast  color. 

I  shall  subjoin  the  prescriptions  for  two  fancy  cochineal  printing  colors. 

.Amaranth  by  cochineal. — Pad  the  pieces  in  the  aluminous  mordant  of  spec,  ffrav  1*027. 
page  230.  *-      s>      ■  » 

Dry  in  the  hot  flue ;  and  after  hanging  up  the  goods  during  3  days,  wince  well  through 
chalky  water,  and  then  dye,  as  follows  : — 

For  each  piece  of  28  or  30  yards,  8  ounces  of  cochineal  are  to  be  made  into  a  decoc- 
tion of  2  gallons  in  bulk,  which  is  to  be  poured  into  a  kettle  with  a  decoction  of  3  ounces 
of  galls,  and  with  two  ounces  of  bran.  The  pieces  are  to  be  entered  and  winced  as  in 
the  madder  bath,  during  two  hours  and  a  half;  then  washed  in  the  dash  wheel.  On  mix- 
ing with  the  amaranth  bath  a  certain  quantity  of  logwood,  very  beautiful  lilachs  and  vio- 
lets may  be  obtained. 

Mixture  of  quercitron  and  cochineal. — Pad  in  the  aluminous  moi-dant,  and  dye  with  2 
lbs.  of  quercitron,  and  4  ounces  of  cochineal,  when  a  capuchin  color  will  be  obtained.  If 
we  pad  with  the  following  mordant,  viz.,  1  gallon  of  acetate  of  alumina  of  1-056  spec. 
grav.,  and  1  of  iron  liquor  of  1-02  spec,  grav.,  and  dye  with  1  pound  of  quercitron,  and 
1  ounce  of  cochineal,  we  shall  obtain  a  shade  like  boot- lops,  of  extreme  vivacity. 

Two  ounces  of  cochineal  will  print  a  long  piece  of  calico  with  rich  pink  figures,  having 
acetate  of  alumina  for  a  mordant.  As  the  ground  is  hardly  tinged  by  the  dye,  it  neither 
needs  nor  admits  of  much  clearing. 

I  have  already  mentioned  that  goods  are  sometimes  padded  with  solution  of  perchloride 
of  tin  before  printing-on  them  the  steam  colors,  whereby  they  acquire  both  permanence 
and  vivacity.  I  have  also  stated  that  the  salts  of  tin  at  a  high  temperature  are  apt  to 
corrode  the  fibre  of  the  stuff,  and  therefore  must  be  used  with  discretion.  This  danger 
is  greatly  lessened  by  adding  to  the  perchloride  of  tin  a  sufficient  quantity  of  caustic 
potash  ley  to  form  a  stannate  of  potash.  The  goods  are  padded  through  this  substance, 
diluted  with  water,  dried  with  a  moderate  heat,  and  then  immersed  in  very  dilute  sul- 
phuric acid,  which  saturates  the  potash,  and  precipitates  the  tin  oxyde  within  the  pores  of 
the  cloth.  Calico  thus  prepared  aflTords  brilliant  and  permanent  colors  by  the  steam  pro^ 
cess,  above  described. 

Printing  of  silks  or  u^llcn  stuffs,  such  as  merinoes  and  mousselin  de  laine,  as  also  of  mix- 
ed stuffs  of  silk  and  wool,  such  as  chalys.—AW  these  prints  are  applied,  not  by  the  cylin- 
der but  the  block,  and  are  fixed  by  the  application  of  steam  in  one  of  four  ways ;  1.  By 
the  lantern ;  2.  By  the  cask;  3.  By  the  chest ;  or,  4.  By  the  chamber. 

1.  By  the  lantern.— In  this  mode  of  exposure  to  steam,  the  goods  are  stretched  upon 
a  frame ;  and  therefore  the  apparatus  may  be  described  under  two  heads ;  the  lantern  and 
the  frame.  The  former  is  made  of  copper,  in  the  shape  of  a  box  a  b  c  d  ^,Jig'  301,  open 
below,  and  with  a  sloping  roof  above,  to  facilitate  the  trickling  down  of  the  water  con- 
densed upon  the  walls.  The  sides  b  c  d  e  are  4|  feet  high,  6  feet  long,  and  4  feet  wide. 
The  distance  of  the  point  a  from  the  line  e  b  is  2  feet.  At  f  is  a  brass  socket,  which 
may  be  stopped  with  a  cork ;  and  there  is  a  similar  one  at  the  other  side.  This  kind 
of  penthouse  may  be  raised  by  means  of  a  pulley  with  cords  fixed  to  the  four  angles 
of  the  roof  e  b  ;  and  it  rests  upon  the  table  g  h,  a  little  larger  than  the  area  of  the  box, 
which  stands  upon  the  four  feet  i  k.  Round  the  borders  of  the  table  there  is  a 
triangular  groove  a  b,  for  receiving  the  lower  edges  of  the  box,  and  it  is  stuffed  steam- 
tight  with  lists  of  cloth.    Through  the  centre  of  the  table,  the  two-inch  steam  pipe  M 


— <>A4 


332 


CALICO-PRINTING. 


ffc'eaua?dktST*'rr^''  *  hemispherical  rose  pierced  with   nomerous  holes  fo, 
me  equal  distribution  of  the  steam.     Right  above  it,  a  disc  n  is  placed  upon  four  feet 
-^  The  tube  l  communicates  with  a  box  p,  which  has  a  syphon  q 

to  let  off  the  condensed  water.  At  the  upper  part  of  this  boy 
the  tube  l  terminates  which  brings  the  steam.  The  little  table 
G  H  slopes  towards  the  part  g,  where  the  syphon  r  is  placed 
for  drawing  off  the  water. 

The  frame  has  such  dimensions,  that  it  may  stand  in  the  four 
corners  of  the  table  at  s  s,  as  pointed  out  by  the  dotted  lines. 
Ihe  second  part  embraces  an  open  square  frame,  which  is 
lonned  by  spars  of  wood  2  inches  square,  mortised  together  • 
and  IS  3  feet  8  inches  wide,  5  feet  8  inches  long,  and  4  feet  3 
inches  high ;  it  is  strengthened  with  cross  bars.  Upon  the  two 
sides  of  its  breadth,  two  rows  of  round  brass  hooks  are  placed 
about  half  an  inch  apart;  they  are  soldered  to  a  copper  plate 
fixed  to  uprights  by  means  of  screws. 

.  Before  hanging  up  the  goods,  a  piece  of  cloth  3  feet  8  inches 

long,  and  4  feet  wide,  is  placed  upon  the  row  of  hooks :  and  3 
feet  of  It  are  left  hanging  out. 
.M?''*'rv  "^'^^.^^^  ^*^°^^^  P^^^  '^''0"Sh  the  cloth.  A  similar  one  is  fitted  to  the  othei 
VfJ!'  Ju  °  ^  *^  intended  to  cover  the  goods  hung  upon  the  hooks ;  and  it  is  kept 
straight  by  resting  upon  strings.  The  pieces  are  attached  zig-zag  from  one  hook  To 
another.  When  the  frame  is  filled,  the  bag  is  put  within  the  clotlis ;  It  haMh.  sa^e  rec^ 
tangular  shape  as  the  frame.  The  pieces  are  in  this  way  all  incased  in  the  ck!h?  a  Wt 
ilru       '  P"'  beneath  to  prevent  moisture  affecting  that  part 

arP  dn?hl!!}?"lf  ^^T^'^'l^!?;  T-  ^"^"^^^  ^'^^  P^"^^  5  and  if  they  be  too  large,  they 
are  doubled  back  to  back,  with  the  fringes  at  top.  »  >  *  '^/ 

oJnlll  ^''^Y!^^''^^  ^^'"^  T^-^'  ^h  ^'"^™^  •'  ^^^  "P°"  t^e  taWe,  the  penthous;  is  pla- 

ItLolt  %r^  %^  '^'^•"  ''  ^'^"J^"'^.  ^""'^^  ^'"""^  3^  *«  4^  ^i""^^^>  ^<^<^°'-ding  to  circuit 
stances.  The  orifice  f  is  opened  at  first  to  let  the  air  escape,  and  when  it  begins  to  dis- 
charge  steam  it  is  stopped.  The  frame  is  taken  out  at  the  proper  lime,  the  baV?s  rt 
moved,  the  cloths  are  lifted  off,  and  the  goods  are  spread  out  for  airing.     Three\am« 

Sfui:Hy':.Sa\7e7ol"sLl^  '  ""'^'^^  ^"""^^^'^  ^'"^^'-  ^^^  above  apparatus  is  par- 

nr^^K^^""  '^''T*;^'^  u^  K^\^  ^°^'  ^'™P^^  "'^^^  ""^  steaming.  The  apparatus  is  a  drum 
of  white  wood,  2  inches  thick,y?g.  302 ;  the  bottom  is  pierced  with  a  hole  which  admiS 
the  steam-pipe  f,  terminating  in  a  perforated  rose.  Four  inches  from  the  bottom  there 
IS  a  canvass  partition  e,  intended  to  stop  any  drops  of  water  projected  from  the  tube  r 
and  also  to  separate  the  condensed  water  from  the  body  of  the  apparatus.  The  drum  is 
covered  m  by  a  wooden  head  h,  under  which  the  goods  are  placed.    It  is  made  fast  either 

by  bolts,  or  by  hooks,  g  g,  thus  oo ,  to  which  weighted  cords  are 
hung.  The  frame  1,  Jig.  302,  rests  upon  a  hoop,  a  a,  a  few  inches 
Irom  the  edge.  The  goods  are  hung  upon  the  frame  in  the  or- 
dmary  way,  and  then  wrapped  round  with  flannel.  The  frame  is 
studded  with  pin  points,  like  that  of  the  indigo  vat,  fixed  about 
5  inches  asunder.  From  20  to  30  minutes  suffice  for  one  steam- 
ing operation.  The  upper  part  of  the  frame  must  be  covered 
also  with  flannels  to  prevent  the  deposition  of  moisture  upon  it. 
At  the  bottom  of  the  drum  there  is  a  stopcock  to  let  off  the  con- 
densed water.  According  to  the  size  of  the  figure,  which  is  3  feet 
2  inches,  50  yards  may  be  hung  up  single;  but  they  may  be  doubled 
on  occasion. 

iA       ^y^  ^^^      /      St  3.  The  box.— This  steaming 

apparatus  is  convenient  from  the 
large  quantity  of  goods  admis- 
sible at  a  time :  it  answers  best 
for  woollen  stuffs.  From  12  to 
16  pieces,  of  36  yards  each,  may 
be  operated  upon  at  once ;  and 
from  240  to  260  shawls.  It  it 
formed  of  a  deal  box,  a  b  cb,  fig, 
t.:^\,    Vu    ~ — J  ,    . "     4.1.      ,.  .  ,       »    .      ,        ~         304  4  feet  wide,  6  Ion?,  and  3 

wwA  ^  T^^^'^V^iJ^'^l^fK*^!?-  ?  ^'  ^^'^'"'^  *»y  "^  *^°^"°^  the  same  substance,  j, 
which  is  made  steam-tight  at  the  edges  by  a  list  of  felt.  The  lid  is  fastened  down  bi  5 
cross  bars  of  iron,  a  a  a  a  a,  which  are  secured  by  screws,  ccccc^fig.  806.  The  ends  of 
these  cross  bars  are  ,et  into  the  notches,  bbbbb,  on  the  edge  of  the  box  The  safetr 
valve  M,fig.  304,  is  placed  upon  the  lid.    For  taking  off  the  lid,  there  are  rings  at  the  fou 


\ 


k 


CALICO-PRINTING. 


333 


immcrs  d  d  d  d,  bearing  cords,  f  r  f  f.    These  join  at  the  centre  into  one,  which  passef 
over  a  puUey.  Eight  inches  from  the  bottom  of  the  box  there  is  a  horizontal  canvass  par 


'^  ••■'•'■"  "" 


806 


d 

EZCD 


305 


tition,  beneath  which  the  steam  is  discharged  from  the  pipe  l,  fig.  306.    There  are  two 
ledges,  E  F  G  H,  at  the  sides  for  receiving  tie  bobbins.    T/j2  tube  l  runs  round  the  box,  as 

shown  by  the  letters  d  a  eb  :  the  end  d  is  shut ; 
but  the  side  and  top  are  perforated  with  many 
holes  in  the  direction  towards  the  centre  of  the  box. 
Fig.  305  shows  the  arrangement  of  the  lower  set 
of  bobbins :  that  of  the  upper  set  is  shown  by  the 
dotted  lines :  it  is  seen  to  be  in  an  alternate  posi- 
tion, one  lying  between  two  others.  They  are 
formed  of  pieces  of  deal  4  inches  broad,  1  inch 
thick,  and  of  a  length  equal  to  the  width  of  the 
box.  They  are  first  wrapped  round  with  5  or  6 
turns  of  doubled  flannel  or  calico :  the  piece  of 
goods  is  laid  over  it  upon  a  table,  and  then 
wrapped  round.  At  the  end  of  the  piece,  several 
folds  of  the  covering  must  be  put,  as  also  a  roll 
of  flannel.  The  two  ends  must  be  slightjy  tied 
with  packthread.  When  these  flat  bobbins  are 
arranged  in  a  box,  the  steam  is  let  on  them,  and 
continued  about  45  minutes ;  it  is  then  shut  off, 
the  lid  is  removed,  and  the  pieces  are  unrolled. 

4.  The  chamber. — ^The  interior  height  of  the 
chamber,  a  b  c  Djfig.  308,  is  nine  feet,  the  length 
12  feet,  and  the  breadth  9  feet.  The  steam  is  in- 
troduceid  into  it  by  two  pipes,  ab  Cy  d  ef.  Their 
two  ends,  d  c,  are  shut ;  but  their  sides  are  all 
along  perforated  with  small  holes.  The  frames 
E  F  g  H,  E  F  g  H,  are  moveable,  and  run  upon 
rollers  :  they  are  taken  out  by  front  doors,  which 
are  made  of  strong  planks,  shut  by  sliding  in 
_  slots,  and  are  secured  by  strong  iron  bars  and 

pressure  screws.  The  cross  rods,  e  r  g  h,  are  provided  with  hooks  for  hanging  up  the 
pieces.  There  is  a  safety-valve  in  the  top  of  this  large  chamber.  The  dimensions  of  the 
frame  are  ten  feet  Ion?,  3  feet  wide,  and  7  high.  Three  feet  and  a  half  from  the  uppei 
part  of  the  frame,  a  row  of  hooks  is  fixed  for  hanging  on  a  double  row  of  pieces,  as  shows 
in  the  figure.  Over  the  frame,  woollen  blankets  are  laid  to  protect  it  from  drops  of  wa- 
ter that  might  fall  from  the  roof  of  the  chamber.  When  the  hooks  are  two  thirds  of  an 
inch  apart,  24  pieces,  of  28  yards  each,  may  be  suspended  at  once.  The  period  of  steam- 
ing is  from  45  to  60  minutes. 

Muslins  and  silks  do  not  require  so  high  a  temperature  as  woollen  goods.  When  the 
stuffs  are  padded  with  color,  like  merinoes  and  chalys,  they  must  not  be  folded  together,  for 
fear  of  stains,  which  are  sometimes  occasioned  by  the  column  in  steam  calico-printing, 
"Where  the  end  which  receives  the  first  impression  of  the  steam  is  seldom  of  the  same 
shade  as  the  rest  of  the  roll  of  goods.  The  duration  of  the  steaming  depends  upon  the 
quantity  of  acid  in  the  mordant,  and  of  saline  solution  in  the  topical  color;  the  more  ot 
■which  are  present  the  shorter  should  be  the  steaming  period.  A  dry  vapor  is  requisite  in 
all  cases ;  for  when  it  becomes  moist,  from  a  feeble  supply  or  external  condensation,  the 
goods  become  streaky  or  stained  by  the  spreading  of  the  colors.  ^ 

1.  Black  figures  are  given  by  decoction  of  logwood  thickened  with  starch,  to  which 
a  little  oxalic  acid  is  added  whUe  hot,  and,  after  it  is  cold,  neutralized  solution  of  nitrate 

of  iron. 

2.  Dark  blue  for  a  ground. — Decoction  of  logwood,  and  archil  thickened  wilh  starch  t 
to  which,  while  the  paste  is  hot,  a  little  soluble  Prussian  blue  is  added ;  and,  when  it  ii 
cold,  neutralized  nitrate  of  iron ;  see  supra. 


334 


CALICO-PRINTmG. 


.xalic'aXfd  re^hi7r?rS".r  ""''  -^"'-j' «^-=>'»ed  with  starch ,  .o  .he  paste  add 

may  be  used  instead  of  the  £,Ltion  rf  i^T/r  '"f '".■"^-  •  '^^^  ^"^"^'"^  ••'»« 

13.  £™e™M  ^_o„fZa^?„f'H''  '?'•'"!«  «?Mi  alum;  thicken  with  gum. 
ries;  MuartofE^nofLSof  If?'''""'"'"',''!"'''  '"  '  P"""""  »f  Persian  ber- 

it,  with  a  ouarter  of  »  r,n,,nH  „r  .       /'        ?>««,  tied  up  in  a  Imen  bag,  are  put  into 

If  the  silkTTndian  half  an  ou^^^'J^r"''  ^T^  "''  '^^'  »"''  "«  '"'W  for  3  ho^r^? 
are  taken  out,  the    are  rLl^  ?„  ?f  ^  soda  crjstals  must  be  added.    When  the  goods 

8  ounces  of  crXliZi  :  o  uJloT'a's  \"  ^1%^  """  ""  '^"°  ^^  "-^^^ 
water,  and  steeped  in  water  verv  fain  r»?,vi,lf  ^  -f^  ^^^J  *''=  "'"^  "»««^''  '■>  eoW 
then  rinsed,  and  dried.  ^  ^  acidulated  with  sulphuric  acid,  during  4  hours, 

f  ;Z''d^ra:{,a1^°;n:ad~4'  o':,I'c?,  %  '"?'•''  ™f"  ■•  ^  •»»'"J^  T-J™  =  -fi-lve : 
.ner''decompositrn':n°d'irblidet:,X:'„ff  cleT'""'  '  "'"""^'  '»^"^''  'o^""-! 

.ing«lWi;rdS^c™o„1f'B:a:nTcJ°tflrk^  -UhM  ounces  of  starch,  and 

the  above  red,  4  ounces  of  sulphite  o'f  copper  '  ''*""^'  ''''^'™' '»  »  S"^""  "f 

<i.  y tout.— Take  1  gallon  of  iron  liquor  of  1-04  spec.  grav.  • 

=^f-^.S^^^  -^ees  .  .j^  -nees  of  copperas . 

3fant«u/a<fL  oT/?/L''''' V''  thickening;  color  with  logwood.^  ^' 

and  llX  ^h^Tef  K'hf  S^^.l^'4i't  '^^^^'  ^'j^^  P"-'  ^^^  ^he  violet, 
the  paste.  The  coppe?  employed  fofllvpl^  ^T''  *"""  'J^  impression,  wash  awa^ 
bran,  at  the  rate  of  4  k  per^lc«^J  ^^^^  ^  ^^^^  ^^  given  with 

temperature  to  130°  F.  Ve  pieced  muJh^^^  7^^^^  '^'?  ""^^^^  ''  ^^^^^  *«  ^«^^r  the 
most,  and  winced  for  half  an  hour  t^S.  ?^^'^  V^  ^^^  P""^^^  ^"^^^^^^  under- 
wilh  the  liquor :  they  are  then  t^t.      ^^  ^T-^""  H^^P  ^^^°^  expanded  and  well  covered 

thefou  J,  2  oups  oTs.:;reitrb:  :SdX'r'pier^^  ^^""'^  '^^^ "  ^  -^«  - 

der^^t^S^p^^trL^^^^^^^^^     n^Sn'd^r ^n^^^^^  ^^  P^^^  ^^  -d- 

must  be  tepid  when  the  pieces  are  enS  ft 'Z^k'  T'^  ^r""*^^  *^^  ^'^""'^  ^he  bath 
and  to  the  boiling  point  il  an  hour  and  a  ia^^  Th^'  ^"T^  '"^  ^^  ^-  ^"  ^0  minutes, 
the  time,  and  finally  turned  out  Tnto  cold  water  ^         """'^  ^'  ^"'^^^  ""^"'"^  ^' 

cie^XrUrokTaVlir^^^^^^^^^^^  color     The,  are 

copper  must  be  now  mounted  with  3  pounds  of  sonn  7  n  *^°'1.^^ter,  and  rmsed.  A 
pailsful  of  bran,  in  which  the  goods  aL  to  be  boi?ed%nr  IZ''  ''^^^^''T  "^*'"'  ^"'^  ^ 
passed  through  a  very  dilute  sulphuric  acid  4th  Thl  f^  ^"^  ^T"".'  ^hen  rinsed,  and 
this  process,  a  light  sklmon  grouid  L  obu' ned  ""'"'  ^"^  ^''    ^^  ^""°^8 


CALICO-PRINTING. 


335 


n.  Steam  colors  upon  silk. — The  same  plan  of  operations  may  be  adopted  here  as  m 
described  for  calico-printing ;  the  main  difference  being  in  the  method  of  mordanting  the 
stuffs.  After  boiling  in  soap  water,  in  the  proportion  of  4  ounces  per  pound  of  silk,  the 
goods  are  washed  in  cold  water,  and  then  in  hot  water  at  140° ;  they  are  next  rinsed, 
passed  through  weak  sulphuric  acid,  rinsed,  squeezed  between  rollers,  and  afterwai-ds 
steeped  in  a  bath  containing  8  ounces  of  alum  per  gallon,  where  they  remain  for  four 
hours,  with  occasionally  wincing.  They  are  now  rinsed  and  dried.  The  subsequent 
treatment  resembles  that  of  steam-color  printed  cottons. 

Jii/j.ck, — Take  a  gallon  of  decoction,  made  with  4  lbs.  of  logwood,  with  which 
14  ounces  of  starch  are  to  be  combiner  •  mix  in 

2  ounces  of  powdered  nut-galls  :  boil,  and  pour  the  color  into  a  pipkin  con- 
taining 
2  ounces  of  tartaric  acid ;  2  ounces  of  oxalic,  both  in  powder,  and 
2  ounces  of  olive  oil.     Stir  the  color  till  it  is  cold,  and  add 
8  ounces  of  nitrate  of  iron,  and  4  ounces  of  nitrate  of  copper. 
The  red,  violet,  lilach,  yellow  colors,  &c.  are  the  same  as  for  steam  colors  upon  cotton. 
Topical  colors  are  also  applied  without  mordanting  the  silk  beforehand.    In  this  case  a 
little  muriate  of  tm  is  introduced.    Thus,  for 

Yellow. — Take   1  gallon  of  a  decoction,  made  with  4  lbs.  of  Persian  beiiies  :  dissolve 

in  it  8  ounces  of  salt  of  tin  (muriate),  and  4  ounces  of  the  nttro-muriatlG 

solution  of  tin.     Thicken  with  2  pounds  of  gum. 

Printing  of  foulard  pieces.    The  tables  which  serve  for  the  impression  of  silk  goods  are 

so  constructed  as  to  receive  them  in  their  full  breadth.    Towards  the  part  between  the 

color  or  sieve  tub  and  the  table,  the  roller  is  mounted  upon  which  the  piece  is  wound. 

This  roller,  A  b,  fig.  309,  has  a  groove,  c,  cut  out  parallel 

to  its  axis.    Into  this  a  bar  is  pressed,  which  fixes  the  end 

of  the  piece.    The  head,  b,  of  the  roller  is  pierced  with 

several  holes,  in  which  an  iron  pin  passes  for  stopping  its 

1      rotation  at  any  point,  as  is  shown  at  b.     At  the  other  end 

-^  of  the  table  there  is  placed  a  comb,  fig.  310,  which  is 

its  ends.    The  teeth  of  the  comb  are  on  a  level  with  the 


309 


^ 


310 

iiinniiiiiiiimiiiiiiiiiiiiiiiiiiiiimiiiiiiiiiimiiiiiiimiiiiifimi 


supported  by  pivots  A  b  at 
cloth. 

The  piece  is  arranged  for  printing  as  follows  : — It  is  unwound,  and  its  end  is  brought 
upon  the  teeth  of  the  comb,  and  made  to  pass  into  them  by  slight  taps  with  a  brush. 
It  is  now  stretched,  by  turning  round  the  roller,  and  fixing  it  by  the  pin-handle. 
After  tracing  the  outline,  the  printing  blocks  are  applied.  Care  should  be  taken,  in 
the  course  of  printing,  always  to  fix  the  teeth  of  the  comb  in  the  middle  line  between 
two  handkerchiefs.  The  operation  of  grounding-in  is  much  facilitated  by  this  plan  of 
extension. 

The  pieces  are  washed  in  running  water,  and  must  be  rapidly  dried.  The  subsequent 
dressing  is  given  by  gum  tragacanth :  they  are  dried  upon  a  stretching  frame,  and  then 
folded  up  for  the  market. 

III.  Mandarining  of  silk  stuffs  and  chalys. — This  style  of  printing  depends  upon  the 
property  which  nitric  acid  possesses  of  giving  to  silk  and  woollen  stuffs  a  yellow  color. 
The  first  step  is  the  scouring  with  a  soap  boil,  as  already  described. 
The  desisns  are  printed-on  as  also  above  described. 

The  swimming  or  color  tub  is  usually  double,  and  serves  for  two  tables ;  instead  of 
being  placed,  therefore,  at  the  end  of  the  table,  it  is  put  between  two,  and,  conse- 
quently, behind  the  printer.  It  is  formed  of  a 
copper  chest,  fig.  311,  A  b  c  r>,  in  which  steam 
may  circulate,  introduced  by  the  pipe  i ;  the  ex- 
cess being  allowed  to  escape  by  the  tube  j,  as  also 
the  water  of  condensation.  The  frame  is  placed 
in  the  hollow  box  k  k.  Between  two  such  frames 
there  is  a  plate  of  copper,  l,  which  closes  the  box ; 
,  it  serves  for  laying  the  plates  in  order  to  keep  them 

not.    At  E  and  h  are  prolongations  of  the  box,  in  which  are  set  the  vessels  f  g  for  hold- 
mg  the  reserve  paste. 

Preparation  of  the  reserve  or  resist  paste.— Melt  in  a  kettle  2^  lbs.  of  rosin;  1 
».  of  suet;  mix  well,  and  put  it  into  the  basins  f  g'.  By  means  of  steam  the 
reserve  IS  kept  melted,  as  well  as  the  false  color  upon  which  the  sieve  floats.  The 
piece  of  silk  being  laid  upon  the  table,  and  the  reserve  spread  upon  the  frame,  the 
printer  heats  his  block,  which  sUould  be  mounted  with  lead,  if  the  pattern  will  per- 
mit, upon  the  little  table  l.  He  takes  up  the  color  from  the  frame,  and  transfers 
u  insiantly  to  the  piece.  He  must  strike  the  block  lightly,  and  then  lift  it,  lest,  by  its 
cooung,  It  might  stick  to  the  silk.  When  the  table  pattern  is  completed,  he  dusts  it 
«ver  with  sand,  and  proceeds  to  another  portion  of  the  silk.    The  piece  must  not  b« 


336 


JALICO-PRINTING. 


taken  out  of  the  stretch  till  it  is  quite  dr>',  which  requires  usually  6  hours.  Let  us  con- 
sider first  the  most  common  case,  that  of  a  white  upon  an  orange  ground.  We  shaL 
afterwards  describe  the  other  styles,  which  may  be  obtained  by  this  process.  The  piece, 
being  printed  and  dry,  must  next  be  subjected  to  the  mandarining  operation. 

322      ^  The  apparatus  here  employed  consists  of  a  sandstone  trough 

A  B  c  D,  fig.  312.  Upon  the  two  sides,  a  c,  b  d,  of  this  trough 
n  are  fixed  two  wooden  planks,  pierced  with  a  hole  an  inch  from 
the  bottom  to  receive  the  roller  e,  under  which  the  piece  passes* 
In  this  trough  the  acid  mixture  is  put.  That  trough  is  put  in- 
to a  wooden  or  copper  trough,  f  g  h  i.  Into  the  latter,  water 
is  put,  which  is  heated  by  means  of  steam,  or  a  convenient  fur- 
nace. Before  and  behind  are  placed  two  winces,  or  reel?,  k  l  ; 
one  serves  to  guide  the  piece  in  entering  into  the  trough,  and 
the  other  in  its  leaving  it.  The  piece  falls  immediately  into  a 
stream  of  cold  water,  or,  failing  that,  jnto  a  large  back,  con- 
taining a  mixture  of  chalk  and  water.  The  two  winces  are 
moved  by  handles :  the  velocity  is  proportioned  to  the  action  of 
the  acid.  The  wince  l  ought  to  be  higher  than  k,  to  allow  the 
acid  to  drain  off.     Fig.  313  shows  a  section  of  the  apparatus. 

The  temperature  of  the  acid  mixture  ought  to  be  maintained 
between  95°  and  100**  F. ;  for  if  it  be  raised  higher,  the  resist 
would  run  the  risk  of  melting,  and  the  impression  would  be- 
come irregular  and  blotty. 

The  proportions  of  the  acid  mixture  are  the  following : — 
1  gallon  of  water ;  and  1  gallon  of  nitric  acid,  of  spec.  grav. 
1-288,  which  may  be  increased  with  the  strength  of  the  silk.     It  should  be  a  little  weaker 
for  chalys.     For  the  strong  greens  it  may  be  2  measures  of  acid  of  1'288  to  1  measure  oJ 
water.     The  duration  of  the  passage  through  the  acid  should  be  1  minute  at  most. 

Mixture  of  orange  color^  and  clearing  away  of  the  resist. — The  goods,  on  coming  out 
of  the  mandarining  apparatus,  are  rinsed  in  running  water;  then  boiled  in  soap  water, 
quickened  with  a  little  soda,  at  the  rate  of  2  lbs.  of  the  former  and  4  oz.  of  the  latter 
for  a  piece  of  30  yards.  They  must  be  worked  by  the  wince  for  half  an  hour.  They 
are  now  rinsed  in  cold  water,  then  passed  through  hot,  again  rinsed,  and  dried.  I  shall 
give  some  examples  of  the  mode  of  manufacture,  which  is  undoubtedly  one  of  the  most 
curious  applications  of  chemical  ingenuity. 

1.  Orange  ground  with  white  figures, 

(1.)  Print-on  the  fat  reserve;  (2.)  mandarine;  (3.)  brighten  the  orange,  and  clear. 

2.  Orange  ground  with  blue  figures. 

(1.)  Dip  in  the  indigo  vat  as  for  calico;  (2.)  print-on  the  fat  resist  to  preserve  the 
blue;  (3.)  mandarine;  (4.)  clear,  and  brighten  the  orange  by  the  boil. 

3.  Orange  ground,  with  blue  and  white  figures. 

(1.)  Print-on  the  resist  to  preserve  the  white ;  (2.)  dip  in  the  vat,  rinse,  and  dry  ;  (3.) 
ground-in  the  fat  resist  to  preserve  the  blue;  (4.)  mandarine;  (5.)  cleanse,  and  brighten. 

4.  Fxill  green  ground,  and  white  figures. 

(1.)  Print-on  the  resist;  (2.)  mandarine,  and  rinse  without  drying;  (3.)  dip  in  the  blue 
vat;  (4.)  cleanse,  and  brighten. 

6.  Full  green  ground,  and  blue  figures. 

(1.)  Dip  a  pale  blue,  rinse,  and  dry  ;  (2.)  print-on  the  fat  resist;  (3.)  mandarine, wash 
and  dry;  (4.)  dip  full  blue;  (5.)  clean,  and  brighten. 

6.  Full  green  ground,  with  white  and  blue  figures. 

(1.)  Print  on  the  resist ;  (2.)  dip  a  pale  blue,  and  dry;  (3.)  ground-in  the  fat  resist; 
(4.)  mandarine  and  rinse ;  (5.)  dip  a  full  blue ;  (6.)  clean,  and  brighten. 

7.  Full  green  ground,  with  white,  blue,  and  orange  figures. 

(1.)  Print-on  the  fat  reserve ;  (2.)  dip  a  pale  blue,  anddiy;  (3.)  ground-in  the  re 
serve;  (4.)   mandarine,  rinse,  and  dry;   (5.)   ground-in  the  reserve;   (6.)  dip  a  full 
blue;   (7.)  clean,  and  brighten. 

If  blue  grounds  with  white  figures  be  wanted,  the  resist  must  be  applied,  and  then 
Che  goods  must  be  dipped  in  the  blue  vat :  the  resist  is  afterwards  removed  by  a  boil  in 
Boap-water. 

The  above  processes  are  applicable  to  chalys. 

The  property  which  nitric  acid  possesses  of  staining  animal  matters  yellow,  such  as 
iiie  skin,  wool,  and  silk,  is  here  applied  to  a  very  elegant  purpose. 

Of  the  bronze  or  solitaire  style  by  mandarining. — The  mandarining  mixture  is 

1  gallon  of  nitric  acid,  of  1*17  spec,  grav.;  mixed  with  3  pints  of  solution  of  nitrate 
of  iron,  of  spec.  grav.  ]*f>5.  If  the  quantity  of  nitrate  of  iron  be  increased,  a  darker 
tint  will  be  obtained.  The  temperature  of  the  mixture  should  be  94®  F.  The  pieces, 
after  mandarining,  are  let  fall  into  water,  anii  steeped  for  an  hoar. 


CALICO-PRINTING. 


337 


In  order  to  raise  the  bronze,  and  clear  away  the  fat  resist,  the  goods  mujt  be  boiled  ii 
a  bath  of  soap  and  soda,  as  described  for  orange. 

1.  Bronze  ground,  with  white  fibres. 

(1.)  Print-on  the  fat  resist;  (2.)  dip  in  the  blue  vat,  and  dry ;  (3.)  pad  in  a  decocaon 
of  logwood  of  4  lbs.  per  gallon  ;  dry,  taking  care  to  turn  over  the  selvages;  (4.)manX 
nne,  and  steep  m  water  for  an  hour;  (5.)  cleanse,  and  pass  through  soa^.   ^ 

2.  Bronze  ground,  vnth  blue  figures.  &  i  • 

(1.)  Dip  in  the  blue  vat,  and  dry ;  (2.)  print-on  the  fat  resist;  (3.)  pad  in  the  abov» 
brfghtn?        ^^         '         ^'''  ^^'^  °^^^d^""e,  and  steep  an  hoir;'  (5.)  cleanse,  aS 

3.  Bronze  ground,  with  white  and  blue. 

(1.)  Print-on  the  fat  resist ;  (2.)  dip  in  the  blue  vat,  and  dry ;  (3.)  ground-in  the  fat  re- 
s^t;  (4.)  pad  m  the  logwood  liquor,  and  dry;  (5.)  ^andariJ^  and  steep  for  an  hoiJ^ 
(6.)  cleanse,  and  give  the  brightening  boil  with  soap.  ^  ' 

This  style  of  manufacture  maybe  executed  on  #.>iaivc.  ^^a  :„  i^i       ,.        ■,     . 

beautiful  effects  which  will  in  vJn  be'^t  foTbf l'^'  ^fn^  "^'^''^  ^'  ^'^""^"^ 

With  silks,  advantage  may  be  derived  from  various  metallic  ^solutions  which  nossess 
the  property  of  staming  animal  substances;  among  which  are  nitrate  of  silTernitm^ of 

LTr7n'te7-on"""''  ''  "'"    ^'^  ^^^"^'^"^  ''  ^^^^^  '^'^  ^^^  ^^  thlktTd'w/^T^ 
^n  orange  upon  an  indigo  vat  ground.-Kdtv  the  blue  ground  has  been  dyed  oranee 
figures  may  be  produced  by  printing-on  the  foUowin?  discharge  paste  --  ^ 

16  toll^onLrnr'nT-^  into  a  paste  with  1  pound  of  starch ;  when  cold,  add  to  it  from 

^.!:^^^i^  sirbo^ii.^"" "''''  ^'"^  ^^"'^  ''^  ^°'-  ^^  ^^^-" 

^rZ^^::^^'^^^  ^-^anblue  In 

A  caustic  ley  being  prepared,  of  1-086  specific  gravity,  disso'lve  in  a  Mllnn  nf  ;,  o 

pounds  of  annono  and  thicken  with  3  pounds  and?  qui'ter  of  gum     Two  days  aft" 

the  impression  of  this  paste,  pass  the  goods  through  steam,  and  wash  therin  Junnin^ 

When  a  uniform  color  is  to  be  anolied  to  both  siVIpc  nf  «Ko  -i««V   .1.        jj- 
employed;  but,  when  only  one  sideTs  "o  b^'i;':' ^^^reS  d  agotuint^'re'ct 

Sdr/tc/htoL'-d"- '""'-''  -opicjaratpj";^  ^^- 

anJfh/hf  ^f  ''-^^r  P'^!,^^  ^^'^°^  ^^^I'^^*  stuff  placed  between  the  cloth  to  be  printed 
and  the  block  printmg-table   or  the  cylinders.     It  should  be  kept  very  clean     because 

of  alumin^'  ^^''  '"'"''  ''  "'''' ''  "^"^'  '^'''  ^"  ^^^  ''^^"^^  ^^^^^  i^ade  wilh  acS 

iUamll?!  ^'^''  \^^  color  shop  of  a  print-house  are  best  made  of  wool,  formed  into  a  sub. 

stantial  conical  cap  by  felting.     A  filter  ought  to  be  set  apart  for  each  dTfSren   dve  .tuff 

When  the  goods  al\er  dyein-  are  washed,  by  bein-  held  bv  ihT^Jtll      v       a       1 

Rust  stains  are  removeable  by  a  mixture  of  oxalic  and  muriatic  acids 

ToSf  \;\r  ^^  ^^  '^"'^^"?,^  ""''r  '^  ^^^^"'^^  «^  1'^-  anTmuriaUc'acid 

CLili.^         '""Ti  "/  ^fl'^"^  ^J'"''  ^y  t^^  ^^^^  combination. 
Metallic  greens  and  Scheele's  green  by  the  acid  alone. 

after'ri^h'hTgoods  munTwi^h'd  "^llf  ""%"^^  '^  ^^^^"  '^  ^^  ^  --»-  «'^«^»M 
'nixture  of  oxairand  muriatio  «^- 1  ''  ^^u  '^f'^^^^y  ^^^^  ^^ain  may  be  removed  by  the 
The  stains  on  sk  and  woolTpn  .f^  '  .,  ^^.^^  "^^^^^^'^  ^^^^'  t« '^^"on  and  linen, 

•oap  bo  1  whirh  nfnv  .1  n  u"^'  '^^'"^^  ^^  ^^"^''^^'^  ^^^^'^  ^xing  the  colors  by  the 
little  wat^J  ^  ^    ''^"^  ^'  '^""^  ^y  scratching  with  the  finger,  with  the  aid  of  a 

Vm  V""^*"'  *'*^**'''  ^^^"'  ^^^  °^y^e  of  Chrome. 
^^'  2X 


338 


CAUCO  PRINTING. 


CALICO  PRINTING. 


339 


;      f 


t 


Mr.  Hudson,  of  Gale,  near  Rochdale,  obtained  a  patent,  in  December,  1834,  for  a  me- 
chanism which  furnishes  a  continual  and  regular  supply  of  color  to  the  sieve  or  tear 
{tire,  Fr.),  into  whicli  the  printer  has  to  dip  his  block,  for  the  purpose  of  receiving  the 
color  about  to  be  transferred  to  the  fabric  in  the  operations  of  printing  calicoes  or  paper 
hangings.  The  contrivance  consists  in  a  travelling  endless  web,  moved  by  power,  which, 
by  passing  progressively  from  the  color  vat  over  the  diaphragm,  brings  forward  continu- 
ftiuly  an  equable  supply  of  the  colored  paste  for  the  workman's  block. 

314  ^  ^ig.    814  represents    the 

construction  of  this  inge- 
nious apparatus,  shown 
partly  in  section,  a  a  is  « 
vessel  of  iron,  supported 
upon  wooden  standards  b  b, 
over  the  upper  surface  of 
which  vessel  a  sheet  or 
diaphragm,  c  c,  of  oiled 
cloth,  or  other  suitable 
elastic  material,  is  dis- 
tended and  made  fast  at 
its  edges  by  being  bent 
over  a  flange,  and  packed 
or  cemented  to  render  the  joints  water-tight.  A  vertical  pipe  d  is  intended  to  conduct 
water  to  the  interior  of  the  vessel  a,  and,  by  a  small  elevation  of  the  column,  to  create 
such  upward  pressure  as  shall  give  to  the  diaphragm  a  slight  bulge  like  the  swimming 
tub. 

An  endless  web,  e  e  e,  passing  over  the  surface  of  the  diaphragm,  is  distended  over  three 
rollers, /g  A,  the  lower  of  which,/,  is  in  contact  with  the  color-roller  t  in  the  color- 
trough  K.  On  the  axle  of  the  roller  i  a  pulley  wheel  is  fixed,  which  allows  the  roller  to 
be  turned  by  a  band  from  any  first  mover ;  or  the  roller  may  receive  rotatory  motion  by  a 
winch  fixed  on  its  axle.  On  this  said  axle  there  is  also  a  toothed  wheel,  taking  into  a 
another  toothed  wheel  on  the  axle  of  the  roller/;  hence,  the  rotation  of  the  color-roller 
t  in  the  one  direction-  will  cause  the  roller  /  to  revolve  in  the  opposite,  and  to  carry  for- 
ward the  endless  web  e  e  e,  over  the  elastic  diaphragm,  the  web  taking  with  it  a  stratum 
of  color  received  from  the  roller  i,  evenly  distributed  over  its  surface,  and  ready  for  the 
printer  to  dip  his  block  into. 

The  axles  of  the  rollers/  and  g  turn  in  stationary  bearings ;  but  the  axle  of  A  is  mounted 
in  sliding  nuts,  which  may  be  moved  by  turning  the  screws  in,  for  the  purpose  of  tight- 
ening the  endless  web.  The  axle  of  the  color-roller  i  turns  in  mortises,  and  may  be  rais- 
ed by  screws  w  in  order  to  bring  its  surface  into  contact  with  ihe  endless  web.  To  pre- 
vent too  great  a  quantity  of  color  being  taken  up,  the  endless  web  passes  through  a  long 
slit,  or  parallel  aperture,  in  a  frame  o,  which  acts  as  a  scraper  or  doctor,  and  is  adjusta- 
ble by  a  screw  p,  to  regulate  the  quantity  of  color  carried  up.  The  contents  of  the  vessel 
a,  and  of  the  color-trough  fc,  may  be  discharged  when  required  by  a  cock  in  the  bottom 
of  each.    See  Paper  Hangings,  for  the  Fondu  style. 

Tne  outside  working  gear  of  the  four-colour  calico  printing  machine,  is  shown  in  Jig. 
315.,  where  a,  a  is  a  part  of  the  two  strong  iron  frames  or  cheeks  in  which  the  various 
rollers  are  mounted.  They  are  bound  together  by  the  rods  and  bolts  a,  a,  a.  b  is  the 
large  iron  pressure  cylinder,  which  rests  with  its  gudgeons  in  bearings  or  bushes,  which 
can  be  shifted  up  and  down  in  slots  of  the  side  cheeks  a,  a.  These  bushes  are 
suspended  from  powerful  screws,  b,  which  turn  in  brass  nuts,  made  fast  to  the  top  of  the 
frame  a,  as  is  plainly  shown  in  the  figure.  These  screws  serve  to  counteract  the  strong 
pressure  applied  beneath  that  cylinder  by  the  engraved  cylinders  d,  e. 

c,  D,  E,  K,  (see  Jig.  297.)  are  four  printing  cylinders,  named  in  the  order  of  their  opera- 
tion. They  consist  of  strong  tubes  of  copper  or  gun  metal,  forcibly  thrust  by  a  screw 
{)re8S  upon  the  iron  mandrels,  round  which,  as  shafts,  they  revolve.  The  first  and  last  cy- 
inders,  c  and  f,  are  mounted  in  brass  bearings,  which  may  be  shifted  in  horizontal  slots 
of  the  frame  a.  The  pressure  roller  b,  against  whose  surface  they  bear  with  a  very 
little  obliquity  downwards,  may  be  nicely  adjusted  to  that  pressure  by  its  elevating  and 
depressing  screws.  By  this  means  c  and  f  can  be  adjusted  to  b  with  geometrical 
precision,  and  made  to  press  it  in  truly  opposite  directions. 

The  bearings  of  the  cylinders  d  and  e  are  lodged  also  in  slots  of  the  frame  a, 
which  point  obliquely  upwards  towards  the  centre  of  b.  Tlie  pressure  of  these  two 
print  cylinders,  c  and  f,  is  produced  by  two  screws,  c  and  d,  which  work  in  brass  nuta 
made  fast  to  the  frame,  and  very  visible  in  the  figure.  The  framework  in  which  these 
bearings  and  screws  are  placed  has  a  curvilinear  form,  in  order  to  permit  the  cylinders 
to  be  readily  removed  and  replaced,  and  also  to  introduce  a  certain  degree  of  elasticity. 
Hence  the  pressure  applied  to  the  cylinders  c  and  f  partakes  of  the  nature  of  a  springs 


»  circumstance  essential  to  their  working  smoothly,  notwithstanding  the  occasional 
inequalities  in  the  thickness  of  the  felt  web  and  the  calico. 

The  pressure  upon  the  other  two  print  cylinders,  d  and  e,  is  produced  by  weights 
acting  with  levers  against  the  bearings.  The  bearings  of  d  are,  at  each  of  their  ends, 
acted  upon  b^  cylindrical  rods,  which  slide  in  long  tubular  bosses  of  the  frame,  and 
press  with  their  nuts  g,  at  their  under  end  upon  the  smaller  arms  of  two  strong  levers 
«,  which  lie  on  each  side  of  the  machine,  and  whose  fulcrum  is  at  h  (in  the  lower 
corner  at  the  left  hand).  The  longer  arms  of  these  levers,  o,  are  loaded  with  weights, 
H,  whereby  they  are  made  to  press  up  against  the  bearings  of  the  roller  d,  with  any 
desired  degree  of  force,  by  screwing  up  the  nut  g,  and  hanging  on  the  requisite 
weights.  ^ 

The  manner  in  which  the  cylinder  k  is  pressed  Up  against  b  is  by  a  similar  con- 
struction to  that  just  described.  With  each  of  its  bearings  there  is  connected  by 
the  link  k,  a  curved  lever  i,  whose  fulcrum  or  centre  of  motion  is  at  o.  Bv  turning 
therefore,  the  screw  m,  the  weight  v,  laid  upon  the  end  of  the  longer  arm  of  the  lever  k 
(of  which  there  is  one  on  each  side  of  the  machine),  may  be  made  to  act  or  not  at  plea- 
sure upon  the  bearings  of  the  cylinder  e.  The  operation  of  this  exquisite  machine 
IS  minutely  described  m  pp.  315,  316. 

A  patent  was  obtained  in  August,  18.^9,  by  Mr.  J.  C.  Miller  of  Manchester,  for  cer- 
tain improvements  m  prikimg  calicoe«,  consisting  of  a  modified  mechanism,  by  which 
tne  same  effect  can  be  produced  as  by  block  printing. 

^r,f^''}]^'  ^7'  ^1?'  ^^e  several  views  of  this  machine,  calculated  to  print  two  pieces, 
or  two  different  pat  erns  (on  the  same  block)  of  calico,  side  by  side,  o^  four  pieces,  the 
from  WoJkL  "^""^^         intended  device  consisting  of  four  colours  to  be  prLted 

^J}^'  ^l^'  ^^P^^^^®'^*^  *,  ^'^^  elevation,  f.g.  317.  a  front  view,  and  Jig.  318.  a  trans- 
verse  section,  taken  nearly  through  the  middle  of  the  machine. 

thli/.  ^'rf  *?  framing  is  shown  at  a,  a,  supporting  the  colour  boxes  b,  L  k  with 
Wieir  doctors  ;  the  furnishing  tables  or  beds,  c,  c,  c,  (substitutes  for  the  sieves  in  ordinary 

2X2 


340 


CALICO  PRINTING. 


CALICO  PRINTING. 


341 


block  printing)  ;   the  printing  table,  d,  d ;   and  the  feeding,  drying,  and  colouring 


The  machine  is  also  provided  with  a  carriage,  t,  i,  for  the  printing  blocks,  y,  j,  j. 
This  carriage,  i,  i,  travels  m  and  out  at  suitable  ihtervals  upon  rails,  &,  fc,  attached  to 
the  mam  irammg. 

The  operation  of  the  machine  is  effected  bypassing  a  driving  strap,  Z,  round  the 
driving  pulley  m  fixed  at  the  extremity  of  the  main  driving  shaft,  «,  n.  At  the  other 
end  of  this  shaft,  the  bevilpmion,o,  IS  keyed,  gearing  at  suitable  intervals  with  the  bevil 
wheelj?  which  is  mounted  upon  the  end  of  the  cross  shaft  q ;  at  about  the  middle  of 
this  shaft,  the  mitre  wheels  r,  r,  driving  the  upright  shaft  s,  5,  and  mitre  wheels  L  L 
above,  actuate,  by  means  of  the  spur  pinions  u,  u,  the  feeding  rollers/,/,  and  thus  d^aw 
the  pieces  of  goods  into  the  machine. 

Simultaneously  with  the  progress  of  the  cloth,  the  mitre  wheels  r,  v,  at  the  other 
end  of  the  cross  shaft  g,  drive  the  furnishing  roUers  w,  w,  w,  by  means  of  the  spur  gear- 
^ng  ar,  X,  X.  The  furnishing  rollers,  revolving  in  their  respective  color-boxes,  spread  or 
?nl?pr  «nVt w"^-\*-^'  travelling  endless  blankets,  y,  y,  y,  which  pass  round  the  top 
roUer  and  the  furnishing  tables  or  beds,  c,  c,  c,  in  order  to  supply  the  colors  to  the 
surfaces  of  the  prin  mg  blocks,  j,  y,  j.  Either  beds  or  the  backs  of  the  printing  block! 
may  be  made  slightly  elastic,  to  insure  the  perfect  taking  up  of  the  colors. 

Supposing  the  carriage,  t,  i,  to  be  run  out  upon  its  railways,  at  the  farthest  point  frort 
!nur  whPPw'  nnnn  ^^^''Z''^  ^.'^^^y'd  toward  the  fumishing  beds  c,  c,  by  means  of  the 
spur-wheel  X,  upon  the  driving-shaft  «,  taking  into  a  small  pinion,  1  (shown  by  dots 
m  fig.  17),  upon  the  shaft,  2  On  the  end  of  this  shaft  is  also  keyed  the  mangle 
pinion  3  gearing  in  the  mangle  wheel,  4,  which  is  keyed  upon  the  end  of  the  shaft!  5 
Is^fil   Id^^'        spur-wheel,  6,  in  gear  with  the  pinion,  7,  made  fast  to  the  shaft,  5 

Upon  either  end  of  the  shaft,  5,  is  a  rack  pinion,  9,  taking  into  the  horizontal  rack  10 
made  fast  to  the  carnage-frame,  i,  i ;  and  thus  the  blocks  j,j,  are  presented  to  the  fur- 
nishing blankets  y,  y,  y,  and  take  a  supply  of  colour  ready  for  printing.  The  travelling- 
carriage  and  blocks  now  retire,  by  the  agency  of  the  mangle-wheel  and  pinion,  3  and  4 
the  pinion  being  fixed  upon  the  end  of  the  shaft,  2,  and  the  wheel  upon  the  other  shaft 
in  a  line  with  the  shaft  2.  At  this  time  another  operation  of  the  machine  takes 
placa 


Upon  the  reverse  end  of  the  shaft  6,  is  a  pinion,  11,  gearing  with  the  spur-wheel 
12;  and  by  means  of  the  spur  gearing,  6  and  13,  and  counter-shaf^  14,  the  pinion  16, 


Zll 


t7Z^^4ra^^ft}'  ^^'  ^h^^\^«Fespond8  to  the  wheel,  12,  on  the  other  side  of  the 
machine^  To  one  of  these  spur-wheels  are  attached  by  bolts  two  quadrant  levers.  17  17- 
and  as  these  wheels  revolve  by  means  of  the  gearing  just  described,  the  eveS  17   17 

ti:  ornri,'trn?Ho\' •'  ''1^''^^%  t,h^  '---^  l^Vnd  20,  and  thus  elevate  Jhewhdi 
series  of  prmtmg  blocks  m  the  parallel  grooves,  21,  21 ;  at  the  same  time  pressing  or 
dosing  them  mto  one  mass  or  block  by  expanding  the  springs,  22,  22 ;  a^d  at  the  nest 
of  the  carnage  caused  at  a  proper  interval  by  the  agency  of  the  maS-wheel  th* 

~'dr^''  T^''''  '^-  P"""'"^  "P^^  '^'  «^^^^^^  «^*he  goods  afonl^  in  fo^ 
Th     1  .f  ^"""^  '"'i''^"''  ^/^  '"  ?^  ^^^'  «••  °^«^^  widths  of  cloth  at  one  operatio^ 
The  cloth  IS  now  drawn  forward  for  the  space  of  the  exact  width  of  one  of  The  blocks. 

Z^  aI  "**  ?^  1^'!?°'  ^^  ""."/^^  ^^  *^^  spur-wheels  and  pinions,  23,  23  and  paS 
around  heated  cylmdera,  g  g,  if  necessary,  and  between  the  delivering  roller^  out  ofihe 

m  n  fT      \  "°*'l  *^^  P"""*'"^  ''  completed ;  the  colours  making  a  single  advance 
01  thc^  pattern  at  every  presentation  of  the  blocks,  until  the  whol?  number  of  bS 
i..t^  been  presented  to  the  same  space  or  portion  of  the  goods  successively 

w^^h  fi^  ^  •    ^"^^^^.^^  carnage,  is  used  for  throwing  the  whiel  »  in  and  out  of  ceS 

woven  of  dead  wool  cannot  be  wpII  AxroA      ni^t^i.  ^e  ^-     j      ^v*""^**"  v.w»,uv/u.     vtuuub 
quire  a  n^^milmr  fr-^airr.^r.i^f       Ti^      X.         ^^^^'^  **'  mixcd  cotton  and  wool  yarns  re- 

Mi ^Hn.  ^LfKol?  "^  *^^  ^^"^^  P"°^^^-  ^^""^^  <lo  not  take  well  on  cotton. 

Phi  a^ni  n?  "^'.^^^'^'^^  curcumme,  oxide  of  iron,  oxide  of  chrome,  arseniuret  of  s^- 
Phur  and  of  antmiony,  are  all  substantive  colours,  and  need  no  mordant  to  fix  th^. 


342 


CALICO  PRINTING. 


CALICO  PRINTING. 


343 


but  they  must  be  presented  to  the  stuff  in  a  soluble  state,  or  rendered  so  by  some  «oW 
ent     llua  proposition  is  well  illustrated  in  the  indigo  dye. 


The  ferruginous  mordants  for  good  dyes,  applied  by  the  plate,  have  almost  always  a 
little  of  a  copper  salt  added  to  facilitate  the  peroxidation  of  the  iron,  and  its  combina- 
tion with  the  stuff.  The  empyreumatical  oil  of  pyrolignous  acid  has  the  power  of 
retarding  the  oxidation,  and  preventing  the  corrosive  action  of  the  ferric  acid  upon  the 
fibres.  The  arsenious  acid  is  employed  for  the  violets  and  lilacs;  it  combines  with  the 
iron-oxide  in  its  normal  state,  and  stops  its  peroxidation.  The  chlor-zine  used  in  the 
-  black  mordant  has  no  tinctorial  operation,  but  it  counteracts  the  tendency  of  the  starch 
thickeners  to  coagulate.  Sal-ammoniac  and  nitre  are  also  in  many  cases  of  great  ser- 
vice in  mordants ;  as  well  as  the  muriates  of  potash  and  soda.  When  pyrolignite  of 
iron  alone  is  used,  the  dyes  are  not  so  rich  as  when  some  purer  acetate  of  iron  is  added 
to  it ;  to  favour  the  more  ready  oxidizement  of  the  metal,  which  should  be  always  intro- 
duced into  the  stuff  in  the  state  of  black  oxide.  The  basic  pjTophosphate  of  iron  being 
soluble  in  alkalis  makes  thus  an  excellent  mordant,  especially  with  ammonia,  which 
may  be  dyed  immediately  after  impression.  When  a  solution  of  sulphate  of  iron  is 
mixed  with  one  of  pyrophosphate  of  soda,  the  whitish  precipitate  may  be  dissolved 
(after  being  washed)  in  water  of  ammonia.  Such  a  mordant  serves  well  for  a  madder 
bath,  and  also  for  many  others. 

Tin  crystals  (chloretin)  dissolved  in  the  sulphuric  acid  of  Nordhausen  to  saturation, 
have  at  first  the  consistence  of  syrup,  but  become  afterwards  solid ;  and  being  kept  out 
of  contact  of  air,  make  the  best  of  all  tin  mordants.  For  some  purposes^  however,  the 
peroxide  of  tin  is  preferable. 

Generalities  of  Calico  Printing. — ^I.  Of  the  colours  fixed  in  the  humid  way,  or  in  the 
water-bath,  and  with  concourse  of  mordants ;  the  simple  genera  are  derived  from  the 
application  of  indigo,  carthamus,  curcuma,  catechu,  and  the  oxides  of  iron  and  chrome ; 
the  peroxides  of  manganese,  and  lead ;  with  the  sulphide  of  antimony. 

1.  From  indigo,  there  are  the  following  species : — 

(1.)  The  blue  vat  or  blue  ground ;  such  as  pencil  blue,  china  blue,  blue  of  solid  appU- 
cation.  Indigo  is  reduced  into  a  soluble  state  by  grinding  in  the  moist  condition  and 
mixing  100  parts  of  it  with  from  75  to  95  parts  of  green  sulphate  of  iron,  and  100  of 
quicklime,  in  the  vat  along  with  8000  parts  of  water,  and  stirring  vigorously  from  time 
to  time.  The  vat  is  best  heated  by  transmitting  steam  into  it  through  pipes.  By  this 
means  the  indigo  vat  may  be  prepared  for  action  in  the  course  of  12  hours.     The  uquid 


should  be  transparent  and  of  a  fine  yellow  hue ;  and  should  have  a  coppery  looking 
pellicle  on  its  surface. 

To  insure  complete  oxidizement  to  the  indigo  in  the  substance  of  the  stuff,  it  may  be 
padded  through  a  weak  solution  of  sulphate  of  copper,  mixed  with  a  little  boiled  starch 
and  glue.    See  Indigo. 

Resist  pastes  for  indigo  may  consist  of  solutions  of  the  copper  salts,  which  act  on  che- 
mical principles  by  furnishing  oxygen  to  the  indigo  and  thus  rendering  it  insoluble  and 
incapable  of  entering  the  fibres  of  the  stuff ;  or  they  are  composed  of  pipe  clay,  sulphate 
of  lead,  and  such  articles  as  act  mechanically.  A  resist  paste  with  sulphate  of  zinc  and 
alum  answers  well  for  brief  immersions  in  the  vat,  and  it  washes  easily  away.  The 
arseniates  and  phosphates  are  sometimes  used  along  with  the  salts  of  copper  to  prevent 
the  fixation  of  this  metal  reduced  upon  the  cloth. 

The  following  are  some  receipts  for  reserve  pastes. 

No.  1-  For  deep  blues.     In  9  quarts  of  water  dissolve, 
12  potmds  of  sulphate  of  copper 

5  —        acetate  of  copper 

6  —        nitrate  of  copper,  at  15**  B. 
6        —        gum  arable 

2        —        pipe  clay ;  the  latter  two  being  thickeners. 
No.  2.  In  9  quarts  of  water  dissolve, 

8  pounds  of  sulphate  of  copper 

4        —        acetate  of  copper 

6|      —        nitrate  of  copper,  at  55*  B.  thickened  with 

4        —        gum  arable 

8        —        pipe  clay 

Na  3.  For  cravats.    In  9  quarts  of  water  dissolve 
8  pounds  of  sulphate  of  copper 
4       —        acetate  of  copper 

4        —        nitrate  of  copper,  at  55«»  B.,  thickened  with 
4        —        of  gum  arable 
8        —        of  pipe  clay. 

In  other  formulae,  a  little  alum  is  used ;  in  others,  verdigris  dissolved  in  vinegar  is 
added  to  the  mixture ;  in  some  a  little  cream  of  tartar  is  introduced,  also  a  very  small 
quantity  of  sulphuric  acid  for  handkerchiefs  to  be  printed  on  both  sides.  In  9  quarts 
of  water,  3  pounds  of  sulphate  of  copper,  ^  pound  acetate,  to  be  thickened  with  | 
pound  of  starch  and  7  pounds  of  gum,  6^  pounds  of  pipe  clay ;  the  whole  being  coloured 
with  1  pound  of  acetate  of  indigo. 

By  another  formula  a  resist  paste  is  made  by  dissolving  in  8  pints  of  water,  20  pounds 
of  sulphate  of  zinc,  incorporated  with 

4^  pounds  of  pipe  clay 


5 
H 


12        — 


of  soft  soap 

of  lard 

olive  oil 

oil  of  turpentine 

of  mucilage  at  2  pounds  per  quart. 


AH  the  above  pastes  should  not  be  thicker  than  what  is  absolutely  necessary,  and  the 
cloth  to  be  printed  should  be  highly  calendered  ;  in  printing  with  blocks  the  workmen 
should  strike  them  with  their  hand  and  not  with  a  mallet.  It  is  advisable  to  dip  the 
frame  with  its  stretched  piece  of  cloth  in  milk  of  lime  before  plunging  it  in  the  vat ;  in 
which  it  should  receive  4  or  more  immersions,  with  airing  intervals  for  the  oxidizement 
of  the  indigo. 

Pen4:il  blue,  as  applied  by  hand. — ^To  35  quarts  of  water,  add  12  pounds  of  car- 
bonate of  potash,  10  of  quicklime,  10  of  indigo,  12  of  realgar.  This  mixture  is  to  be 
boiled  for  2  hours,  then  poured  into  a  tub  to  settle,  when  the  clear  part  is  to  be 
thickened  with  gum  arable  in  the  proportion  of  1  pound  to  4.  The  insoluble  matter 
18  treated  with  a  fresh  quantity  of  water,  and  boiled  repeatedly  till  it  be  quite  exhausted, 
and  It  then  serves  ulterior  purposes.  For  this  prescription  mav  be  substituted  with 
advantage  a  solution  of  the  realgar  in  caustic  potash,  so  as  to  avoid  the  annoyance  intro- 
duced by  the  linae.  This  pencil  blue  has  been  of  late  successfully  applied  by  the  cylinder 
press,  working  in  an  atmosphere  of  coal  gas,  to  prevent  the  oxidizement  by  the  atmo- 
spheric oxygen,  till  the  web  was  all  uniformly  printed. 

Of  the  styles  of  colour  derived frmn  Carthamus  («a^ow^).—Safflower  being  washed  in 
pure  water,  is  to  be  immersed  in  solution  of  carbonate  of  soda,  of  which  the  weight 


344 


CALICO  PKINTING. 


CALICO  PRINTING. 


345 


i 


I 


I 


should  in  no  case  exceed  that  of  the  safflower;  for  an  excess  of  it,  or  too  long  digestion 
or  at  too  high  a  temperature,  must  be  avoided.  The  alkaline  compound,  called  cartha- 
mate  of  soda,  is  to  be  poured  into  an  oval  tub,  having  a  discharge  pipe  at  its  bottom 
and  two  supports  at  each  end  of  the  tub,  for  bearing  the  pivots  of  the  reel  round  which 
the  cloth  IS  coiled,  and  which  is  turned  bv  means  of  a  handle.  The  liquid  being  shghtly 
super-saturated  with  lemon  juice,  passes  from  orange  to  a  lively  pink  hue,  and  becoTning 
cartharmne  is  ready  to  be  deposited  upon  the  cloth  as  it  revolves  in  the  tub  Silkf 
which  have  been  sulphured,  are  to  be  previously  passed  through  a  soda  batk  But 
brighter  colours  are  obtained  upon  cotton. 

Of  tli^  styles  of  colour  derived  from  curcuma  {turmeric).  This  drug  is  emploved 
chiefly  to  modify  the  tmts  produced  by  other  dyes:  bto  a  decoction  of  it  any  kiud  of 
goods,  cotton  silk,  wool,  or  linen,  being  immersed,  take  a  yellow  stain  witliout  any 
mordant.  This  substance  has  been  associated  with  Brazil-wood  for  printing  certain 
Jcmds  of  silk  handkerchiefs  with  a  mordant  of  iron  and  alumina 

The  colours  derived  from  arinotto.— To  d  ve  cloth  with  annotto.  an  alkaline  decoction  is 
to  be  made  of  it,  along  with  a  solution  of  dextrine,  into  which  the  cloth  is  to  be  plunged 
It  needs  no  mordant,  and  affords  an  orange  brown  dye,  after  the  alkali  has  been  neu- 
tralized by  an  acid  bath.     A  solution  of  peroxide  of  tin  brightens  the  dye 

Of  the  styles  of  printing  by  means  of  catechu,~\.  This  dye  stuff,  combined  with  the 
blue  vat  produces  very  fine  blacks.  Catechu  is  prepared  for  dyeing  by  dissolving  in  9 
quarts  of  water,  7i  pounds  of  it  along  with  1  pound  of  acetate  of  copper,  2  pounds  of 
sal  ammoniac,  and  10  pounds  of  gum  arabic.  ii     '     i 

2.  To  9  quarts  of  pyrolignous  acid,  put  three  pounds  of  catechu  in  fine  powder,  which 
has  been  steeped  in  12  quarts  of  water.  The  mixture  is  to  be  evaporated  at  a  gentle 
heat,  till  it  be  reduced  by  one  tenth,  allowed  to  settle,  and  set  aside  for  use 

lo  9  quarts  of  the  above  prepared  catechu,  there  are  to  be  added  2^  pounds  of  sal 
ammoniac,  4  of  gum  arabic,  5  of  pipe  clay,  and  1  of  nitrate  of  copper. 

Introducing  into  this  preparation  salts  which  promote  oxidation,  the  shade  may  be 
modified   and  other  colours  produced.     Thus,  in  adding  to  6  quarts  of  the  above  6 
quarts  of  acetate  of  protoxide  of  iron,  at  12°  B.  and  9  pounds  of  gum  arabic ;  or  adding 
to  9  quarts  of  the  above  catechu  preparation,  14  quarts  of  water,  18  of  mucilage  con 
taming  2  pounds  of  gum  per  quart,  and  9  of  protacetate  of  iron  of  9°  B 

This  colour,  which  is  employed  for  cylinder  printing,  may  be  extensively  modified  • 
the  acetate  of  iron  may  be  replaced  by  a  mix-ture  of  acetate  and  sulphate,  or  even  by 
the  nitrate,  if  the  proportions  of  the  other  soluble  matters  be  changed.  If  the  prepara- 
tions are  to  be  rendered  more  oxidable,  a  little  corrosive  sublimate  or  chloride  of  tin 
may  be  added. 

Catechu  with  manganese  (acetate  of)  either  alone,  or  with  acetate  of  copper  forms 
an  excellent  dye  Catechu  is  also  united  with  alkalis,  and  with  sulphate  of  chrome  or 
tartaro-acetate  of  copper;  chlor-calcium  and  acetate  of  lime  are  likewise  introduced 
into  the  formulae  by  some  printers,  for  the  purpose  of  keeping  the  mordants  moist,  as 
the  colours  of  catechu  are  thereby  rendered  richer. 

After  having  exposed  the  goods  printed  with  one  or  other  of  the  mixtures  for  some 
days  to  a  humid  atmosphere,  from  a  hazel  nut  tint  they  become  of  a  marron  hue  The 
colours  are  then  fixed  by  steaming,  or  by  means  of  a  chromate  or  of  lime  as  a  milk  or 
water.  ' 

Alkaline  catechu  gives  a  brown  red  impression.  9  quarts  of  the  decoction  of  catechu, 
at  i  pound  per  quart,  are  to  be  thickened  with  2^  pounds  of  flour,  and  when  it  S 
boiled,  4i  quarts  of  solution  of  caustic  soda  at  a  density  of  10°  B.  By  varying  the 
proportion  of  catechu  without  changing  the  ratios  which  exist  among  the  other  sub- 
stances stronger  or  fainter  shades  may  be  obtained,  but  only  after  several  days'  diges- 
tion.    Lime  18  used  for  fixing  such  colours.  j        s 

Of  the  colours  derived  from  the  application  of  the  peroxide  ofiron.-jQne  of  the  ferni- 
gmous  preparations  here  employed  is  the  nitro-sulphate  of  iron  (protoxide).    It  is  made 
by  adding  to  10  quarts  of  nitric  acid,  about  three  times  its  weight  of  sulphate  of  iron  bv 
very  slow  degrees  m  a  large  vitriol  bottle ;  and  by  the  mutual  action  of  these  ingredient^ 
a  portion  of  ammonia  is  formed     Six  days  are  required  to  complete  this  coiiipound. 
Towards  the  conclusion  the  sulphate  must  be  added  very  slowly,  otherwise  frothiig  will 
ensue  in  the  thickening  hquor.     It  is  liquid  at  the  temperature  of  59°  Fahr.  and  has  a 
density  of  5G°  to  o7°  B    When  cooled  below  that  point  it  has  a  tendency  to  crystallize. 
It  should  always  be  diluted  to  a  strength  of  from  18°  to  22°  B.  before  being  used. 
To  d>^e  with  this  preparation  it  is  to  be  diluted  to  the  desired  degree,  and  put  into  the 
padding  trough  where  it  serves  to  impregnate  the  goods  uniformly.     They  are  then 
transferred  to  the  stove  where  they  are  to  be  dried,  but  not  to  hardness,  for  fear  of 
corroding  the  fibres  by  the  red  oxide  of  iron  ;  they  are  next  passed  through  a  peculiar 
padding  machine  containing  a  weak  solution  of  carbonate  of  soda  mixed  with  a  little 
quicklime.    In  proportion  as  the  cloth  is  passed  through  the  bath,  and  its  alkaline  matter 


gets  neutralized,  it  must  be  refreshed  with  fresh  solution  of  soda.  The  cloth  may  be 
supplied  by  a  soap-bath  ;  and  lastly  by  the  dash-wheel.  If  the  iron  orange  tint  is  not 
sufficiently  deep  by  one  operation,  it  may  be  increased  by  another,  and  also  rendered 
more  uniform.  A  mixture  of  red  muriate  of  iron  and  sal  ammonia  gives  a  good  iron 
dye,  and  with  perfect  safety;  or  one  of  red  sulphate  and  sal  ammoniac.  Goods  padded 
in  iron  liquor,  dried,  and  then  padded  in  a  solution  of  chlorine  containing  a  little  free- 
lime,  acquire  a  good  rurSt  ground.  The  following  prescriptions  serve  as  resist  pastes 
for  these  dyes.  In  9  quarts  of  hot  water  dissolve  5  lbs.  of  the  biarsenate  of  potash,  and 
add  to  the  solution  as  much  carbonate  of  potash  as  to  give  it  a  slight  alkaline  reaction. 
Dividing  this  liquor  into  two  equal  parts,  there  is  to  be  incorporated  with  the  first,  10 
lbs.  of  pipe-clay,  and  to  be  dissolved  in  the  second  4|  lbs.  of  gum  Senegal,  with  |  of  a 
pound  of  soft  soap ;  the  two  are  to  be  united.  This  resist  is  to  a  certain  degree  of  a 
mechanical  quality,  for  the  ferruginous  preparation  cannot  touch  it,  without  setting 
the  fat  acid  of  the  soap  at  liberty  and  preventing  the  entrance  of  the  liquor  into  the 
pores  of  the  web. 

White  resists  on  rust  grounds  are  also  made  with  a  mixture  of  tartaric  and  oxalic 
acids;  as  also  of  lime  juice.  When  the  iron  oxide  is  fixed,  as  in  the  genus  avanturine, 
muriate  of  tin  is  a  preferable  discharge ;  as  for  example : 

In  9  quarts  of  water  diffuse  3^  lbs.  of  flour,  1  lb.  of  starch,  and  boil  into  a  paste ; 
and  add  to  2  lbs.  of  this  paste,  2  lbs.  of  acid  muriate  of  tin  at  65°  B.  (solution  of  salt 
of  tin  in  muriatic  acid.)  This  for  printing  with  the  block.  For  printing  on  the  dis- 
charge paste  by  the  cylinder,  to  2  lbs.  of  the  paste  are  to  be  added  4  lbs,  of  the  acid 
muriate  of  tin  at  65°  B.  In  these  preparations  the  combined  action  of  the  muriatic 
acid  and  muriate  of  tin  is  sufficient  to  displace  the  oxide  of  iron ;  but  the  paste  must 
not  be  left  long  exposed  to  the  air,  otherwise  the  iron  may  become  fixed  by  peroxi- 
dizement.  White  discharge  upon  chamois  (a  faint  rust  colour)  is  produced  by  II  lbs. 
of  gum  arabic,  2^  lbs.  of  oxalic  acid,  2  lbs.  of  tartaric  acid,  |  lb.  of  oil  of  vitriol  After 
applying  this  discharge  the  goods  should  not  be  exposed  to  a  high  heat  to  dry  them. 
The  first  of  these  two  receipts  tends  to  crystallize,  the  second  to  deliquesce.  It  deserves 
to  be  remarked,  that  when  soda  is  employed  to  precipitate  rust  of  iron  upon  goods, 
tlie  tint  is  much  deeper  than  it  is  by  lime. 

Of  the  colours  produced  by  the  oxide  of  chroTne. — A  preparation  for  this  purpose  is 
made  by  boiling  together  2  lbs.  of  bichromate  of  potash,  and  4  lbs.  of  muriatic  acid. 
The  muriatic  acid  excess  is  to  be  evaporated  off.  For  obtaining  deeper  shades,  arsenic 
acid  is  introduced  in  determinate  proportions ;  as  for  example : 

To  9  quarts  of  water,  there  are  added  9  lbs.  of  bichromate  of  potash,  12  of  arsenious 
acid,  and  20  or  22  lbs.  of  muriatic  acid,  in  oi'der  to  destroy  all  the  chromic  acid,  and 
that  the  chlorine  set  at  liberty  in  contact  with  the  water  and  the  arsenious  acid  may 
transform  the  last  into  arsenic  acid  by  the  oxygen  of  the  decomposed  water.  When 
the  reaction  has  ceased,  a  fine  green  liquor  results,  which  is  to  be  evaporated  to  the 
density  of  60°  or  65°  B.  to  dissipate  the  free  acid ;  care  should  be  taken  to  get  rid  of 
the  acid  excess  either  by  a  regulated  heat  or  by  soda.  Man}'  pieces  of  calico  are  dyed 
a  fine  green  by  the  oxide  of  chrome,  and  are  very  fast. 

The  solution  of  muriate  of  chrome,  just  described,  at  a  density  of  45°  B.,  is  to  be 
thickened  slightly  with  gum,  poured  into  a  padding  machine,  then  dried  carefully  to  aid 
the  fixation  of  the  colour,  and  finally  passed  through  a  weak  bath  of  soda:  to  complete 
the  deposition  of  the  oxide  of  chrome,  ammonia  may  be  substituted  for  the  carbonate 
of  soda.     The  colours  thus  produced  are  pale  green,  or  grey,  but  may  be  deepened  by 

gassing  the  cloth  through  a  weak  bath  of  sulphate  of  copper ;  it  may  be  deepened  also 
y  mixing  with  arsenic  acid,  and  after  some  days'  repose,  precipitating  the  ai'seniate 
of  chrome  on  the  stuff  by  passing  it  through  a  bath  of  carbonate  of  soda. 

Of  the  simple  genera  derived  from  oxide  of  manganese. — This  colour  is  generally  known 
by  the  name  of  solitaire  bistre,  and  sometimes  turks-head.  By  impregnating  the  cloth 
"with  a  neutral  solution  of  acetate  of  manganese,  then  precipitating  the  oxide  with  an 
alkali,  exposing  the  goods  to  the  air  to  favour  the  oxidation,  or  passing  them  through 
a  bath  of  chlorite  of  lime,  the  process  of  the  manganese  dye  may  be  executed.  After 
passing  the  goods  through  the  manganese  bath  over  8  rollers,  to  secure  uniformity  of 
impression,  they  should  be  dried  immediately  in  a  stove.  The  d^e-bath  should  contain 
a  small  quantity  of  mucilage  of  gum  arabic.  The  alkali  for  precipitating  the  oxide  of 
manganese  in  the  padding  machine  should  be  caustic,  strong,  and  heated  by  a  steam  pipe 
to  the  boiling  point.  The  strength  of  the  alkaline  solution  should  in  all  cases  be  14° 
B. :  and  for  some  purposes  even  22°  B.  This  alkaline  strength  is  requisite  to  seize  the 
fibre  the  instant  of  the  tissue  entering  the  alkaline  bath,  and  to  force,  by  the  contraction 
which  it  causes,  the  oxide  of  manganese  to  remain  within  it  till  the  oxidation  is  com- 
pleted. It  is  obvious  that  the  bath  must  be  kept  up  by  fresh  alkali.  The  two  last 
cylinders  of  the  frame  should  be  heavily  loaded,  so  as  to  render  the  goods  as  dry  as  pos- 
sible. A  passage  through  solution  of  chlorine  is  in  general  advantageous  to  complete  the 
Vol.  L  2  Y 


I  il 


346 


CALICO  PRINTING. 


CALICO   PRINTING. 


347 


oxidation  of  the  manganese.  A  more  economical  process  would  be  to  add  an  equiva- 
lent of  sal  ammoniac  to  an  equivalent  of  chlorman^anese,  and  to  make  the  solution 
alkaline  with  a  little  ammonia.  The  goods  padded  m  this  liquor  might  be  dried  with- 
out risk  of  injury,  and  be  then  finished  in  the  baths,  firat^  of  milk  of  lime,  and  next  of 
chlorine :  or  at  once  in  a  mixture  of  the  two. 

The  shades  with  a  foundation  of  manganese  are  often  modified  in  various  ways ;  as 
by  adding  to  the  mixture  a  certain  quantity  of  acetate  of  lead,  whence  results  chlorlead ; 
while  in  passing  into  the  solution  of  chlorlime,  the  lead  is  transformed  into  peroxide, 
whose  brownish  yellow  added  to  the  tint  of  the  manganese  produces  a  yellowish  cast 
and  a  velvety  aspect.  Sometimes  some  salts  of  iron  are  added,  which  decomposed  and 
peroxidized  along  with  the  salts  of  manganese  give  shades  which  resemble  aventurine, 
the  more  closely  the  larger  the  proportion  of  iron. 

PrusHan  blue. — Its  white  discharge  is  effected  upon  calico,  by  preparing  a  rust 
ground  of  a  proper  tint  for  producing  with  acidulated  ferrocyanure  of  potash  the  desired 
blue  shade.  Into  either  the  mordant  or  into  the  ferrocyanide  put  the  quantity  of  muriate 
of  tin  necessary  to  give  the  blue  its  purest  tint.  The  discharge  is  performed  usually  at 
two  operations,  by  the  first  the  ferrocyanure  is  decomposed  by  a  powerful  base  (potash), 
which  forms  a  yellow  cyanure,  and  liberates  the  iron  oxide ;  by  the  second,  we  remove 
the  iron,  by  the  intervention  of  an  acid.  But  the  success  of  this  second  operation  depends 
on  the  energy  of  the  first,  and  especially  upon  the  washings  which  follow  it,  and  which 
ought  to  have  carried  off  the  whole  of  the  ferrocyanure ;  otherwise  the  presence  of  the 
acid  would  regenerate  the  blue  upon  the  points  which  should  remain  clear  of  it  The 
pieces,  after  being  dried  and  calendered,  receive  an  impression  with  caustic  potash  ley 
(thickened  with  gum),  and  which  in  every  case  should  mark  at  least  14°  B.,  m  order  to 
make  the  texture  contract  or  shrink  suitably,  and  furnish  a  precise  or  sharp  print  It 
is  then  to  be  rinsed  and  washed  in  the  dash-wheel  so  as  to  clear  away  every  thing  but 
the  oxide  of  iron  from  the  cloth  upon  all  points  touched  by  the  alkali.  The  piece  is 
then  immersed  in  water  acidulated  with  muriatic  or  sulphuric  acid,  till  the  oxide  of 
iron  has  entirely  disappeared.  By  adding  to  the  potash  a  little  tartrate  of  potash,  the 
oxide  of  iron  from  the  Prussian  blue  enters  into  combination  with  the  tartaric  acid,, 
and  goes  off  in  a  great  measure  with  the  subsequent  washings. 

This  style  may  also  be  executed  upon  silk  and  woollen  goods,  but  great  precaution 
must  be  used  to  avoid  injuring  the  texture  by  the  strong  alkaline  ley.  Silk  handker- 
chiefs are  first  passed  for  about  thirty  minutes  through  a  bath  of  nitrate  of  iron  of  4°  B. 
then  through  running  water,  next  through  the  dash-wheels.  They  are  next  put  in  a  bath 
of  clear  and  cold  lime  water,  in  order  to  decompose  the  salt  of  iron,  and  to  fix  the  oxide 
upon  the  stuff.  It  is  now  rinsed,  and  sent  through  the  dash-wheel  before  proceeding 
to  dye  it;  which  is  done  by  passing  it  through  a  tub  sharpened  with  a  little  sulphuric 
acid,  and  containing  a  small  quantity  of  ferrocyanure  of' potash.  After  workmg  the 
cloth  fifteen  or  twenty  minutes  in  this  bath,  a  little  more  acid  and  ferrocyanure  are  in- 
troduced, and  the  passage  of  the  cloth  is  resumed  during  fifteen  minutes  more,  which 
time  is  usually  sufficient  to  produce  the  desired  tint     It  might  be  better  to  decompose 

{)reviously  in  a  separate  vessel  the  ferrocyanure  by  adding  to  one  equivalent  of  it  in  so- 
ution  two  equivalents  of  sulphuric  acid.  The  mixture  of  sulphate  of  potash  and  fer- 
rocyanic  acid  thence  resulting,  should  be  poured  by  degrees  into  the  dyeing  bath,  till 
the  due  tint  is  produced,  or  the  oxide  of  iron  on  the  cloth  becomes  saturated.  When 
the  ground  has  been  thus  dyed,  the  discharge-printing  may  be  proceeded  with  as  already 
directed.  Muriate  of  tin  may  sometimes  be  substituted  for  acid,  for  acidifying  tlie 
ferrocyanure  of  potash  in  the  act  of  dyeing. 

By  substituting  oxide  of  copper  for  oxide  of  iron,  a  crimson  colour  is  obtained  with 
the  ferrocyanure. 

Saxoii  Mice  ;  solution  of  indigo  in  ndphuric  acid. 
This  blue  dye  is  given  by  passing  the  cloth  mordanted  with  base  of  alumina  through 
the  indigo  solution  of  a  proper  degree  of  strength.    It  enters  also  as  an  ingredient  in 
certain  pistachio  green  dyes. 

TJie  genera  of  styles  derived  from  madder  are  numerous. 
Plain  grounds  upon  ordinary  cloth ;  albuminous  mordant 
^o*  ;  iron  mordant, 

^®*  ;  mordant  of  alumina  and  iron, 

.    .   ^<^'  ;  mordant  of  chrome. 

Plain  printing;  white  reserve  with  mordants  of  alumina,  iron,  or 
chrome, 
do.  white  discharge  upon  common  madder  dye. 

do.  white  discharge  on  oiled  cloth,  with  madder  dye; 

mordants  of  iron  (violet  and  lilac)  upon  the  cy- 
linder. ^ 


There  are,  1. 
2. 
8. 
4. 
5. 

6. 

n. 


White  ground;  printing  with  alumina  mordant  for  red  and  pink  upon  the  cylinder 

White  ground ;  printing  on  mordants  of  alumina  and  iron. 

White  ground;  printing  on  mordants ;  for  red,  violet,  puce,  black  ;  a  binary,  three- 
fold  and  fourfold  union  of  these  colours. 

White  ground ;  printing  on  mordants,  for  red,  violet^  or  puce ;  separate  or  combined ; 
bv  the  block  or  Perrotine.  Plain  ground  upon  oiled  mordanted  cloth :  with  alumina 
of  iron.    Turkey  red,  or  violet  oiled.  .,  j    wu 

White  ground;  printing  with  mordant  of  iron  and  alumina  upon  oiled  cloth. 

The  colours  obtained  directly  by  madder  are  red  and  its  gradations,  pale  red  and  pinky 
■which  have  always  an  aluminous  mordant  for  their  base  ;  black  and  its  gradations  :  deep 
violet,  light  violet,  and  lilac,  of  which  the  base  is  pyrolignite  of  iron,  or  the  common 
acetate  ;  red  and  deep  puce,  whose  mordant  is  a  mixture  of  aluminous  and  iron  liquore ; 
lastly,  the  veiitre  dc  biclie  fixed  by  means  of  the  oxide  of  chrome. 

In  every  print  woi-t,  three  principal  mordants  are  prepared  beforehand  in  a  certain 
state  of  concentration,  which  are  diluted  when  wanted  with  water,  but  more  frequently 
with  gum-water,  and  vinegar.  ,-      ,     ^ 

A.  Mordant  for  red  is  made  with  100  quarts  of  boiling  water  in  which  are  dissolved 
150  pounds  of  alum;  and  then  150  pounds  of  pyrolignite  of  lead  added. 

B.  Mordant  for  red, 

100  quarts  of  water,  in  which  are  dissolved, 

70  pounds  of  alum,  48  pounds  of  acetate  or  pyrolignite  of  lead,  2*  pounds  of  car- 
bonate of  soda  (crystals),  4  pounds  of  muriate  of  soda. 

C.  Mordant  for  red.  _  - 
In  100  quarts  of  boiling  water  are  to  be  dissolved, 

66  pounds  of  alum ;  and  then  to  be  added, 
56  pounds  of  pyrolignite  of  lime,  and 
5  pounds  of  soda  carbonate  in  crystals. 

Red  Mordant  ^,    .,.  .  j  j-     i 

To  66  quarts  of  decoction  of  logwood,  add  100  quarts  of  boiling  water;  and  dissolve 
in  this  mixture  67  pounds  of  alum,  56  pounds  of  pyrolignite  of  lead,  and  6  pounds  of 

Other  mordants  are  made  of  like  quantity  in  which  decoction  of  quercitron  is  put 
along  with  chlorzinc ;  some  into  which  an  admixture  of  chalk  is  made,  others  with  an 
admixture  of  acetate  of  lead,  and  some  chalk. 

The  blacks  are  made  by  strong  mordants,  with  some  salt  of  copper. 

Cochineal  is  used  much  in  the  same  way  as  for  the  madder  printing  and  discharges, 
and  the  mordants  are  much  the  same  ;  Brazil  wood  printing  is  of  like  nature :  as  also 
logwood  dyes.  The  styles  of  printing  derived  from  mixed  colours  are  innumerable  ;  but 
all  proceed  on  the  principles  already  laid  down.  ..       ^    ^i. 

Calico  Printing  by  Steam.— AW  textile  fibres  do  not  attract  colouring  matters  to  them 
with  an  equal  poVer,  but  they  may  be  rendered  capable  of  acting  with  more  or  less  force 
bv  adventitious  aids,  of  which  the  use  of  steam  conjoined  with  the  salts  or  oxides  of  tin 
forms  two  of  the  most  remarkable.  Tlie  muriate  or  chloride  of  tin  is  decomposed  by  the 
action  of  water  into  muriatic  acid  and  oxide  of  tin,  the  first  of  which  is  expelled  by  the 
heat  of  steam,  or  it  may  be  neutralized  by  the  intervention  of  a  saturating  substance ; 
while  the  second  is  never  set  at  liberty  in  presence  of  cloth  without  making  such  a  body 
with  it  as  to  resist  all  the  means  of  discharge  employed  for  the  removal  of  the  other 
substances,  and  without  fixing  at  the  same  time  on  the  fibres  the  colouring  matter  pre- 
viously mixed  with  it  The  same  reasoning  may  be  applied  to  the  muriate  of  alumina. 
Oxalic  acid  fulfils  at  once  the  functions  of  these  two  saline  compounds.  It  is  an  agent 
employed  to  remove  the  oxides  or  the  mordants ;  and  this  application  is  based  upon  the 
affinity  which  it  has  for  alumina  and  iron.  When  deposited  upon  a  mordanted  cloth, 
it  may  either  make  the  whole  of  the  oxide  disappear,  if  used  in  sufficient  quantity,  or  it 
may  restore  it  in  whole  or  in  part  eventually,  if  the  contact  be  prolonged  at  the  ordinary 
teniperature  or  immediately  when  exposed  to  steam.  It  is  thereby  easy  to  explain 
certain  phenomena,  since  by  its  energetically  dissolving  the  oxides,  it  preserves  them 
in  solution  during  the  whole  period  of  printing  them,  and  then  quits  them  under  the  in- 
fluence of  a  steam  heat ;  and  leaves  them  on  the  cloth  in  all  their  properties  when  alone. 
It  is  to  this  peculiar  property  of  the  oxalic  acid  that  we  must  ascribe  the  solidity  of 
certain  topical  blacks,  for  which  it  has  been  long  employed. 

The  tartrates  and  tartaric  acid  concur  also  to  the  same  end ;  but  the  athnity  ot  this 
acid  for  the  bases,  and  the  force  with  which  it  masks  them,  render  its  application  more 
limited  than  the  oxalic  acid.  It  is  useful  for  eflfecting  displacements,  and  for  preserving 
oxides  in  solution,  so  as  to  insure  homogeneity  to  colours.  , 

Acetic  acid  enters  also  as  an  ingredient  into  steam  printing ;  possessing  a  solvent 

2Y2 


348 


CALOMEL. 


CALORIFERE  OF  WATER. 


849 


power  difiFerent  from  the  other  acids,  and  being  applicable  in  a  state  of  concentration 
without  corroding  the  tissues,  it  is  applied  in  circumstances  where  «ubstances  of  a 
more  or  less  resinous  nature  need  to  be  kept  in  solution  in  order  to  being  printed  on ; 
whilst  quitting  under  the  influence  of  heat  the  bases  with  which  it  is  associated,  it  allows 
them  to  contract  an  intimate  union  with  the  stuffs.  The  salts  of  copper  and'chromate 
of  potash  are  employed  to  perform  the  oxidizing  power  of  the  absent  air. 

The  colours  fixable  b}^  steam,  after  having  been  suitably  thickened,  are  to  be  printed 
with  the  nicety  appropriate  to  each,  and  the  goods  covered  with  them  should  be  previ- 
ously exposed  for  some  time  to  a  damp  atmosphere.  In  the  steaming  process,  the  goods 
are  coiled  round  a  perforated  hollow  cylinder  charged  with  steam  by  a  central  pipe,  or 
they  are  exposed  on  frames  in  single  pieces  without  mutual  contact  in  wooden  cases  filled 
with  steam.  Care  must  be  had  to  prevent  the  dropping  down  of  condensed  steam  upon 
the  goods.  When  rolled  up  in  a  cylindrical  form,  they  are  wrapped  in  blanket  stuff.  Of 
late  years  contrivances  have  been  made  to  keep  the  cloth  moving  in  the  steam  so  as  to 
receive  the  equal  benefit  of  its  action.  A  great  variety  of  other  forms  of  this  steam-bath 
are  in  use,  according  to  the  fancy  of  the  operators.  "But  in  all  cases  there  should  be  a 
redundance  of  highly  elastic  steam,  of  vesicular  quality,  which  is  secured  by  causing 
it  to  bubble  up  through  a  stratum  of  water  lying  on  the  bottom  of  the  case. 

CALOMEL.  {Chlonire  de  Mercure,  Fr. ;  Vermsstes  Quecksilber,  Germ.)  The 
mild  protochloride  of  mercury.  The  manufacture  of  this  substance  upon  the  great  scale 
may  be  performed  in  two  ways.  The  cheapest  and  most  direct  consists  m  mixing 
1|  part  of  pure  quicksilver  with  1  part  of  pure  nitric  acid,  of  sp.  grav.  from 
1-2  to  1-25;  and  in  digesting  the  mixture  till  no  more  metal  can  be  dissolved,  or  till 
the  liquid  has  assumed  a  yellow  colour.  At  the  same  time  a  solution  of  1  part  of 
common  salt  is  made  in  32  parts  of  distilled  water,  to  which  a  little  muriatic  acid  is 
added :  and,  when  heated  to  nearly  the  boiling  point,  it  is  mixed  with  the  mercurial  solu- 
tion. The  two  salts  exchange  bases,  and  a  protochloride  of  mercury  precipitates  in  a 
white  powder,  which  after  being  digested  for  some  time  in  the  acidulous  supernatant 
liquor,  is  to  be  washed  with  the  greatest  care  in  boiling  water.  Tlie  circumstances  which 
may  injure  the  process  are  the  following :— 1.  When  less  mercury  is  employed  than  the 
acid  can  dissolve,  there  is  formed  a  deuto-nitrate  of  mercurj^  which  forms  some  corrosive 
sublimate  with  the  common  salt,  and  causes  a  proportionaldefalcation  of  calomel.  2.  K 
the  liquors  are  perfectly  neutral  at  the  moment  of  mixing  them,  some  subnitrate  of  mer- 
cury is  thrown  down,  which  cannot  be  removed  by  washing,  and  which  gives  a  noxious 
contamination  to  the  bland  calomel,  llie  acid  prescribed  in  the  above  formula  obvi- 
ates this  danger. 

The  second  manner  of  manufacturing  calomel  is  to  grind  very  carefully  4  parts  of 
corrosive  sublimate  (bichloride  of  mercury)  with  3  parts  of  quicksilver,  adding  a  little 
water  or  spirits  to  repress  the  noxious  dust  during  the  trituration.  The  mass  is  then 
introduced  into  a  glass  globe,  and  sublimed  at  a  temperature  gradually  raised.  Th« 
quicksilver  combines  with  the  deutochloride,  and  converts  it  into  the  protochloride  or 
calomel     The  following  fonnula,  upon  the  same  principle,  was  recommended  to  the 

chemical  manufacturer  in  Brande's  Journal,  for  July,  1818: 

Prepare  an  oxysulphate  of  mercury,  by  boiling  25  pounds  of  mercury  with  35  pounds 
of  sulphuric  acid  to  dryness.  Triturate  31  pounds  of  this  dry  salt  with  20  pounds  4 
ounces  of  mercury,  until  the  globules  disappear,  and  then  add  17  pounds  of  common 
salt  The  whole  is  to  be  thoroughly  mixecf,  and  sublimed  in  earthen  vessels.  Between 
46  and  48  pounds  of  pure  calomel  are  thus  produced:  it  is  to  be  washed  and  levigated 
in  the  usual  way."  The  above  is  the  process  used  at  Apothecaries'  Hall,  London.  The 
oxysulphate  is  made  in  an  iron  pot;  and  the  sublimation  is  performed  in  earthen  ves- 
sela  The  crystalline  crust  or  cake  of  calomel  should  be  separated  from  the  accompany- 
ing grey  powder,  which  is  nearest  the  glass,  and  consists  of  mercury  mixed  with  cor- 
rosive sublimate. 

An  ingenious  modification  of  the  latter  process,  for  which  a  patent,  now  expired,  was 
obtained  by  Mr.  Jewell,  consists  in  conducting  the  sublimed  vapours  over  an  extensive 
surface  of  water  contained  in  a  covered  cistern.     Thfi  calomel  thus  obtained  is  a  supe 
nor  article,  m  an  impalpable  powder,  propitious  to  its  medical  efficacy. 

The  presence  of  corrosive  sublimate  in  calomel  is  easily  detected  by  digesting  alcohol 
upon  It,  and  testing  the  decanted  alcohol  with  a  drop  of  caustic  potash,  when  the  cha- 
racteristic brick-coloured  precipitate  will  fall,  if  any  of  the  poisonous  salt  be  present 
To  detect  subnitrate  of  mercury  in  calomel,  digest  dilute  nitric  acid  on  it,  and  Uat  the 
acid  with  potasli,  when  a  precipitate  will  fall  in  case  of  that  contamination.  As  it  is 
a  medicine  so  extensively  administered  to  children  at  a  very  tender  age,  its  purity  ought 
to  be  scrupulously  watched.  r       J      & 

118  parts  of  calomel  contain  100  of  quicksilver 

A  patent  was  obtained  in  September,  1841,  by  Anthony  Todd  Thomson,  M.  D., 


for  an   improved  method   of  manufacturing  calomel  and  corrosive  sublimate,   as 

follows : —  J.  ■  ,.   1.  # 

This  invention  consists  in  combining  chlorine  in  the  state  of  gas  with  the  vapour  of 
mercury  or  quicksilver,  in  order  to  produce  calomel  and  corrosive  sublimate. 

The  apparatus  employed  consists  of  a  glass,  earthenware,  or  other  suitable  vessel, 
mounted  in  brick-work,  and  communicating  at  one  end  with  a  large  air-tight  chamber, 
and  at  the  other  end,  by  means  of  a  bent  tube,  with  an  alembic,  such  as  is  generally 
used  in  generating  chlorine  gas.  Tlie  alembic  is  charged  with  a  mixture  of  common 
salt,  binoxide  of  manganese  and  sulphuric  acid,  or  of  binoxide  of  manganese  and  mu- 
riatic acid,  in  order  to  produce  chlorine  gas. 

The  mode  of  operating  with  this  apparatus  is  as  follows : — ^A  quantity  of  mercury 
or  quicksilver  is  placed  in  the  glass  vessel,  and  the  temperature  of  the  same  is  raised  to 
between  850°  and  660°  Fahr.,  by  means  of  an  open  fire  beneath.  The  chlorine  gas,  as 
it  }B  generated,  passes  from  the  alembic  through  the  bent  tube  into  the  glass  vessel,  and 
there  combining  with  the  vapour  of  the  mercury,  forms  either  corrosive  sublimate  or 
calomel,  according  to  the  quantity  of  chlorine  gas  employed. 

The  product  is  found  at  the  bottom  of  the  air-tight  chamber,  and  may  be  removed 
from  the  same  through  a  door,  when  the  operation  is  finished. 

According  to  the  patent  of  Mr.  Josiah  Jewell,  the  vapour  of  calomel  was  to  be 
transmitted  into  a  vessel  containing  water,  in  order  to  condense  it  at  once  into  an 
impalpable  powder.  But  this  process  was  beset  with  many  difficulties.  The  vapour 
of  the  calomel  was  afterwards  introduced  into  a  large  receiver,  into  which  steam  was 
simultaneously  admitted ;  but  this  plan  has  also  been  found  to  be  precarious  in  the 
execution.  The  best  way  is  to  sublime  the  calomel  into  a  very  large  chamber  from  an 
iron  pot,  in  the  same  way  as  the  flowers  of  sulphur  are  formed.  The  great  body  of  cool 
air  serves  to  cause  the  precipitation  of  the  calomel  in  a  finely  comminuted  state.  It  ia 
afterwards  washed  with  water,  till  this  is  no  longer  coloured  by  sulphuretted  hydrogen. 
CALORIC.  The  chemical  name  of  the  power  or  matter  of  heat. 
CALORIFERE  OF  WATER.  {Calorifere  d*eau,  Fr. ;  Wasser-Heitzung,  Germ.) 
In  the  Dictionnaire  Technologique,  vol.  iv.,  published  in  1823,  we  find  the  following  de- 
scription of  this  apparatus,  of  late  years  so  much  employed  in  Great  Britain  for  heating 
conservatories,  &c.,  by  hot  water  circulating  in  pipes  : — 

"This  mode  of  heating  is  analogous  to  that  by  stove-pipes  :  it  is  effected  by  the  circu- 
lation of  water,  which,  like  air,  is  a  bad  conductor,  but  may  serve  as  a  carrier  of  caloric 
by  its  mobility.  We  may  readily  form  an  idea  of  the  apparatus  which  has  been  employed 
for  this  purpose.    We  adapt  to  the  upper  part  of  either  a  close  kettle,  or  of  an  ordinary 

cylindric  boiler  a,  fig.  319,  a  tube  b,  which  rises  to  a  certain 
I  height,  then  descends,  making  several  sinuosities  with  a  gentle 

\TJ  319  slope  till  it  reaches  the  level  of  the  bottom  of  the  boiler,  to  whose 

^^  lowest  part,  as  that  which  is  least  heated,  it  is  fitted  at  c. 

At  the  highest  point  of  the  tube  r  we  adapt  a  vertical  pipe,  des- 
tined to  serve  as  an  outlet  to  the  steam  which  may  be  formed  if 
the  temperature  be  too  much  raised :  It  serves  also  for  the  es- 
cape of  the  air  expelled  from  the  water  by  the  heat :  and  it  per- 
mits the  boiler  to  be  replenished  from  time  to  time  as  the  water 
is  dissipated  by  evaporation ;  lastly,  it  is  a  tube  of  safety. 

"The  apparatus  being  thus  arranged,  and  all  the  tubes  as 
well  as  the  boiler  filled  with  water,  if  we  kindle  fire  in  the  grate 
D,  the  first  portions  of  water  heated,  having  become  specifically 
lighter,  will  tend  to  rise  :  they  will  actually  mount  into  the  up- 
per part  of  the  boiler,  and,  of  course,  enter  the  tube  b  f  :  at 
the  same  time  an  equivalentquantityof  water  will  re-enter  the 
boiler  by  the  other  extremity  c  of  the  tube.  We  perceive  that 
these  simultaneous  movements  will  determine  a  circulation  in 
the  whole  mass  of  the  liquid,  which  will  continue  as  long  as  heat  is  generated  in  the  fire- 
place ;  and  if  we  suppose  that  the  tubes,  throughout  their  different  windings,  are  applied 
against  the  walls  of  a  chamber,  or  a  stove-room,  the  air  will  get  warmed  by  contact  with 
the  hot  surfaces ;  and  we  may  accelerate  the  warming  by  multiplying  these  contacts  in 
the  mode  indicated. 

"This  calorifere  cannot  be  employed  so  usefully  as  those  with  heated  air,  when 
It  is  wished  to  heat  large  apartments.  In  fact,  the  passage  of  heat  ihrouirh  metallic 
plates  is  in  the  ratio  of  the  difference  of  temperatureandquantity  of  the  heating  surfaces. 
In  the  present  case,  the  temperature  of  the  water,  without  pressure,  in  the  tubes,  must  be 
always  under  100°  C.  (212°  F.),  even  in  those  points  where  it  is  most  heated,  and  less 
still  in  all  the  other  points,  while  the  temperature  of  the  flues  in  air  staves,  heated  directly 
by  the  products  of  combustion,  may  be  greatly  higher.     In  these  stoves,  also,  the  pipes 


■;( 

Hi 
'ih 


4 


340 


CALICO  PRINTING. 


block  printing)  ;   the  printing  table,  d,  d ;   and  the  feeding,  drying,  and  colouring 
roUera,/,/ 5r,5r.  A,^ 


;> 


The   machine  is  also  provided  with  a  carriage,  t,  i,  for  the  printing  blocks    i  ?i 
S^mSrSmi^g:  '^"'^  "  '^^^  ""'  ^'  ^"^'^'^^  ^^^^^  ^P-^  -^^  ^>  rattlci'e'd  t'c 

The  operation  of  the  machine  is  effected  by  passing  a  drivinffstran  /  rm,nH  tv,» 
dnymg  puUey  m,  fixed  at  the  extremity  of  the  main  drifine  shift  ^  7'  At  t^Pnt? 

wheel  ;>  which  is  mounted  upon  the  end  of  the  cross  shaft  q ;  at  about  the  middle  of 
?hovl^^^^  "^^'^  wheels  rr,  driving  the  upright  shaft  ,,  ,  and  mitre  Xels"  / 
tl'^^TTi^J.^'^l'''^:^!''^'^'  "'  ^'  ^^^  feeding  rollers/,/,  and  th^^^a^ 
Smmltaneously  with  the  progress  of  the  cloth,  the  mitre  wheels  r,  v  at  the  other 

lltltT^T^lT  ^.'  t^'^'  '\f  ^^^^^^K  roUe;s  «,,  .., ,.,  by  means'of  the  spur  gea^ 
^ng  X,  ^,  X.    The  furnishing  rollers,  revolving  in  their  respective  color-boxes  spread^ 

rltlr  anVte"fSh?nl'?^f """  'l^'r  '^^"'^^^'  ^^  ^ '^^  which  pass  round'  hfto"^ 
roller  ana  the  turnishmg  tables  or  beds,  c,  c,  c,  in  order  to  supply  the  colors  to  th^ 

^""^f  hrn^i.'*"'!?  mJ'^^  ^^°-'^^'  •''.'  •^■'  •^*-     Either 'beds  or  the  backs  of  the  printing  bloJk* 
SnnnnZt  tS^  ^-  ^^^^^^ic,  to  insure  the  perfect  taking  up  of  the  colons.        " 

the  beds  c^c    it Td'rfwn''  •'  ''  ^'  r  "";  "P""  ^^^  ^^^^^^y«'  ^^  t^^  f-^thest  point  froi. 
me   beas  c,  c,   it  is  drawn  inward  toward  the  furnishinff  beds  c  c  h\  means  of  tht 

spur.wheela:,upon  the  driving-shaft  «,  taking  into  a  smk  plL^^Xwu  bf  dot^^ 
m  /g.  17),  upon  the  shaft,  2.     On  the  end  of  this  shaft  is  also  keyed  t^e  manele 

?'hT\^^?f  •"°^i"  '^'  "'""J^",  ^^^^^'  4'  ^^i<^^  i«  keyed  u,^n  the  end  of  the  7^1 
leefil   IdT""         «P^^-^h^^'>  «^  i'^  gear  with  the  pLion,^  made  fast  to  the  sh^',! 

Upon  either  end  of  the  shaft,  5,  is  a  rack  pinion,  9,  taking  into  the  horizontal  rack  10, 
made  fast  to  the  carnage-frame,  t,  i ;  and  thus  the  blocks  j,  j,  are  presented  to  the  fur- 
nishing blankets  y  y,  y,  and  take  a  supply  of  colour  ready  for  printing.  The  traveUinc- 
carriage  and  blocks  now  retire,  by  the  agency  of  the  mangle-wheel  and  pinion,  3  and  4 
the  pmion  being  fixed  upon  the  end  of  the  shaft,  2,  and  the  wheel  upon  the  other  shaft 
in  a  Ime  with  the  shaft  2.  At  this  time  another  operation  of  the  machine  takes 
placa. 


CALICO  PRINTING. 


341 


Upon  the  reverse  end  of  the  shaft  6,  is  a  pinion,  11,  gearing  with  the  spur-wheel 
12;  and  by  means  of  the  spur  gearing,  6  and  13,  and  counter-shaft>  14,  the  pinion  16, 


317 


drives  the  spur-wheel,  16,  which  corresponds  to  the  wheel,  12,  on  the  other  side  of  the 
machine.  To  one  of  these  spur-wheels  are  attached  by  bolts  two  quadrant  levers,  17, 17  • 
and  as  these  wheels  revolve  by  means  of  the  gearing  just  described,  the  levers,  17*,  17| 
draw  down  the  chains,  18, 18,  actuate  i\xQ  levers,  19  and  20,  and  thus  elevate  the  whole 
eeries  of  printing  blocks  in  the  parallel  groove^  21,  21 ;  at  the  same  time  pressing  or 
closing  them  into  one  mass  or  block  by  expanding  the  springs,  22,  22;  and  at  the  nest 
of  the  carriage  caused  at  a  proper  interval  by  the  agency  of  the  mangle-wheel,  the 
blocks  are  made  to  impress  the  patterns  upon  the  surface  of  the  goods  at  once,  in  four 
<»i-  more  different  colours,  and  in  one,  two,  or  more  widths  of  cloth  at  one  operation. 

The  cloth  is  now  drawn  forward  for  the  space  of  the  exact  width  of  one  of  the  blocks, 
or  sketch  of  the  design,  by  means  of  the  spur-wheels  and  pinions,  23,  28,  and  passed 
around  heated  cylinders,  g  g,  if  necessary,  and  between  the  delivering  rollers  out  of  the 
machine.  These  operations  are  to  be  repeated  by  the  continuous  rotation  of  the  main 
<lriving-shaft,  until  the  printing  is  completed ;  the  colours  making  a  single  advance 
upon  the  pattern  at  every  presentation  of  the  blocks,  until  the  whole  number  of  blocks 
lijis  been  presented  to  the  same  space  or  portion  of  the  goods  successively. 

Tlie  steam  pipes,  24^  are  to  be  in  connection  with  the  printing  table  and  drying 
cylinders,  in  order  to  supply  a  degree  of  heat  during  the  operation,  which  may  be 
regulated  at  pleasure. 

To  give  suitable  intervals  of  rest  and  motion  to  the  various  parts  of  the  driving- 
gear,  an  ordinary  clutched  box,  25  (shown  in  fig.  318.X  and  regulated  by  suitable  stops 
fixed  to  the  travelbng  carnage,  is  used  for  throwing  the  wheel  p,  in  and  out  of  gear 
with  the  pinion,  o;  this  is  to  prevent  clots  of  colour  from  being  dragged  upon  the 
blocks  or  c\oi\i.— Newton' i  Journal^  xxi.  C.  S.  p.  242. 

General  Observation^.— -The  cotton  of  Pernambuco  takes  a  more  lively  Turkey  red 
dye  than  that  of  Georgia,  and  both  are  preferable  to  the  Macedonian  cotton.  Goods 
woven  of  dead  wool  cannot  be  well  dyed.  Cloth  of  mixed  cotton  and  wool  yarns  re- 
quire a  peculiar  treatment  from  the  calico  printer.  Blues  do  not  take  well  on  cotton. 

Indigotine,  carthamme,  curcumine,  oxide  of  iron,  oxide  of  chrome,  arseniuret  of  sul- 
phur and  of  antimony,  are  all  substantive  colours,  and  need  no  mordant  to  fix  them  • 


342 


CALICO  PRINTING. 


CALICO  PRINTING. 


343 


l\ 


ii 


III 


but  they  must  be  presented  to  the  stuff  in  a  soluble  state,  or  rendered  so  bv  some  boIv 
ent.     rhis  proposition  is  well  illustrated  in  the  indigo  dye. 


The  ferruginous  mordants  for  good  dyes,  applied  by  the  plate,  have  almost  alwava  - 
ittleof  a  copper  salt  added  to  facilitate  the  peroxidation  of  the  iron,  and  ks  coSa 
^.t^^nM  "^f\-  ^^'  f^Py^^^^^^^^^^^  oil  of  pyrolignous  acid  has  the  ^wercS" 
retarding  the  oxidation,  and  preventing  the  corrosive  action  of  the  ferric  acid^pon  the 
fibres.  The  arsenious  acid  is  employed  for  the  violets  and  lilacs;  it  combines  S  t  le 
iron-o«<ie  in  ite  norma  state,  and  stops  its  peroxidation.  The  chlor-zinc  med^t  tC 
-  black  mordant  has  no  tinctorial  operation,  but  it  counteracts  the  tendency  oTtTe  SaJch 
thickeners  to  coagulate.     Sal-ammoniac  and  nitre  are  also  in  many  casef  of  great  ir 

JZ  1?  °^°^^*^^,'  ,tf  ^""  ^'  *^"  °^""'^*^  ""^  P""'^'^  ««d  «>^^     When  pyrof'gnite  of 

ron  alone  is  used,  the  dyes  are  not  so  rich  as  when  some  purer  acetate  of  iron  fadded 

to  It ;  to  favour  the  niore  ready  oxidizement  of  the  metal,  which  should  be  always  intn^ 

duced  into  the  stuff  in  the  state  of  black  oxide.  The  basic  pyrophosphato  of  iron  S 

^Iv  iVL  S"- '  "'^^n  i^"V°  ^^'^"^^^  °^^^^^«*'  especVall/with  ammoniTwhicg 
may  be  dy^d  immediately  after  mipression.  When  absolution  of  sulphate  of  i7on  is 
mixed  with  one  of  pyrophosphate  of  soda,  the  whitish  precipitate  miy  be  dissoWed 

Tm  crystals  (chloretm)  dissolved  in  the  sulphuric  acid  of  Nordhausen  to  saturation 
have  at  first  the  consistence  of  syrup,  but  become  afterwards  solid ;  and  being  kept  out' 

GenercUities  of  Calico  FHnting.^l.  Of  the  colours  fixed  in  the  humid  way.  or  in  the 
water-bath,  and  with  concourse  of  mordants;  the  simple  genera  are  derived  from  the 
apphcation  of  indigo,  carthamu^  curcuma,  catechu,  and  the  oxides  of  iron  and  chr^e 
the  peroxides  of  manganese,  and  lead ;  with  the  sulphide  of  antimony  ' 

1.  From  indigo,  there  are  the  following  species  •— - 

(1.)  The  blue  vat  or  blue  ground ;  such  as  pencil  blue,  china  blue,  blue  of  solid  appU- 
eation.  Indigo  is  reduced  into  a  soluble  stato  by  grinding  in  the  ioist  condition^and 
mixing  100  parts  of  it  with  from  75  to  95  parts  of  green  lulphato  of  iron,  and  100  of 
qmcklime,  m  the  vat  along  with  8000  parts  of  water,  and  stirring  vigorously  from  time 
to  time  The  vat  is  best  heated  by  transmitting  stoam  into  it  through  pipes.  X  hi^ 
the  mdigo  vat  may  be  prepared  for  action  in  the  course  of  12  houi^    Thefiq^d 


to  time 
means 


should  be  transparent  and  of  a  fine  yellow  hue ;  and  should  have  a  coppery  looking 
pellicle  on  its  surface. 

To  insure  complete  oxidizement  to  the  indigo  in  the  substance  of  the  stufl^  it  may  be 
padded  through  a  weak  solution  of  sulphate  of  copper,  mixed  with  a  little  boiled  starch 
and  glue.     See  Indigo. 

Resist  pastes  for  indigo  may  consist  of  solutions  of  the  copper  salts,  which  act  on  che- 
mical principles  by  furnishing  oxygen  to  the  indigo  and  thus  rendering  it  insoluble  and 
incapable  of  entering  the  fibres  of  the  stuff;  or  they  are  composed  of  pipe  clay,  sulphate 
of  lead,  and  such  articles  as  act  mechanically.  A  resist  paste  with  sulphate  of  zinc  and 
alum  answers  well  for  brief  immersions  in  the  vat,  and  it  washes  easily  away.  The 
arseniatos  and  phosphates  are  sometimes  used  along  with  the  salts  of  copper  to  prevent 
the  fixation  of  this  metal  reduced  upon  the  cloth. 

The  following  are  some  receipts  for  reserve  pastes. 

No.  1.  For  deep  blues.     In  9  quarts  of  water  dissolve, 
12  pounds  of  sulphate  of  copper 

5  —        acetate  of  copper 

6  —        nitrate  of  copper,  at  16'  B. 
6         —         gum  arabic 

2        —        pipe  clay ;  the  latter  two  being  thickeners. 
Bfa  2.  In  9  quarts  of  water  dissolve, 

8  pounds  of  sulphate  of  copper 


4 

6| 
4 

8 
Ko.  3.  For  cravats. 


acetate  of  copper 

—  nitrate  of  copper,  at  55*  B.  thickened  with 

—  gum  arabic 

—  pipe  clay 

In  9  quarts  of  water  dissolve 
8  pounds  of  sulphate  of  copper 
4        —        acetate  of  copper 

4        —        nitrate  of  copper,  at  55*  B.,  thickened  with 
4         —         of  gum  arabic 
8         —        of  pipe  clay. 

In  other  formulie,  a  little  alum  is  used ;  in  others,  verdigris  dissolved  in  vinegar  is 
added  to  the  mixture ;  in  some  a  little  cream  of  tartar  is  introduced,  also  a  very  small 
quantity  of  sulphuric  acid  for  handkerchiefs  to  be  printed  on  both  sides.  In  9  quarts 
of  water,  3  pounds  of  sulphate  of  copper,  \  pound  acetate,  to  be  thickened  with  » 
pound  of  starch  and  7  pounds  of  gum,  6^  pounds  of  pipe  clay ;  the  whole  being  coloured 
with  I  pound  of  acetate  of  indigo. 

By  another  formula  a  resist  paste  is  made  by  dissolving  in  8  pints  of  water,  20  pounds 
of  sulphate  of  zinc,  incorporated  with 

4J  pounds  of  pipe  clay 


5 
li 

u 

12 


of  soft  soap 

of  lard 

olive  oil 

oil  of  turpentine 

of  mucilage  at  2  pounds  per  quart. 


All  the  above  pastes  should  not  be  thicker  than  what  is  absolutely  necessary,  and  the 
cloth  to  be  printed  should  be  highly  calendered  ;  in  printing  with  blocks  the  workmen 
should  strike  them  with  their  hand  and  not  with  a  mallet.  It  is  advisable  to  dip  the 
frame  with  its  stretched  piece  of  cloth  in  milk  of  lime  before  plunging  it  in  the  vat ;  in 
which  it  should  receive  4  or  more  immersions,  with  airing  intervals  for  the  oxidizement 
of  the  indigo. 

Pencil  blue,  as  applied  by  hand. — ^To  35  <juarta  of  water,  add  12  pounds  of  car- 
bonate of  potash,  10  of  quicklime,  10  of  indigo,  12  of  realgar.  This  mixture  is  to  be 
boiled  for  2  hours,  then  poured  into  a  tub  to  settle,  when  the  clear  part  is  to  be 
thickened  with  gum  arabic  in  the  proportion  of  1  pound  to  4.  The  insoluble  matter 
is  treated  with  a  fresh  quantity  of  water,  and  boiled  repeatedly  till  it  be  quite  exhausted, 
and  it  then  serves  ulterior  purposes.  For  this  prescription  may  be  substituted  with 
advantage  a  solution  of  the  realgar  in  caustic  potash,  so  as  to  avoid  the  annoyance  intro- 
duced by  the  lime.  This  pencil  blue  has  been  of  late  successfully  applied  by  the  cylinder 
press,  working  in  an  atmosphere  of  coal  gas,  to  prevent  the  oxidizement  by  the^  atmo- 
spheric oxygen,  till  the  web  was  all  uniformly  printed. 

Of  the  styles  of  colour  derived  from  Carthamus  {safflower). — SaflSower  being  washed  in 
pure  water,  is  to  be  immersed  m  solution  of  carbonate  of  soda,  of  which  the  weight 


344 


I 


III 


CALICO  PKINTING. 


mate  of  soda,  is  to  b^  poured  x^^  an  oval  tub  h^^^^a'd;'?"'"?"^"^'  «^!'«^  «-tha- 

5?^  V^u'.^PP^'-^^  «*  «««^  ««d  of  the  tub^for  blrinTthe  nlf'^'f  t>P'^'  ?^  '^'  ^^^^^^ 
the  Cloth  18  coiled,  and  which  is  turned  bVmears  of!  h\n5  'o?^  ^^'  reel  rou^d  which 
euper-saturated  with  lemon  juice,  passes  ffororanifo?i'-i  ^^}^!T'^  being  slightly 
carthamine  is  ready  to  be  iposiLd  upoTthe  c^nf^^^^ 

which  have  been  sulphured,  are  to  beCevx'^uslv  n  ^"^^/.^^^^^  i"  the  tub.  Silk? 
brighter  coloui-s  are  obtained  upon  cotton  ^  ^""''"^  *^'^"^^  *  ^^^  ^ath.    But 

chi|;ta;^^^^^^^^^^  This  drug  is  emploved 

Mnds  of  silk  handkerchiefs  with  rmoTda    tf  iro'n'anf^^^^^  '^^  ^^^^^^  -^*- 

77ie  colours  derived  from  annotto  —To  Hv^^LfT    ^,    ^^""^^^a- 
to  be  made  of  it,  alon^  with  a  Xtion  of  /ex^^^^^^^^  J^f  "?^^""^:  ^°  ^^^^^^'^^  <^-o<^tion  is 
It  needs  no  mordant,  and  affords  an  oranteWw    a""  ^^Y"^  *^^  ^^^^^  ^«  *<>  ^e  plunged, 
tralized  by  an  acid  bath.     A  solution  of  p^eroSo^^^^^^  t^'V^''  ^^^'"'^  ^"^  ^^^^  ^«"- 

.  blue  vat,  produces  very  fine  blacks.     cTiloh.\Z  '  ^l^  ^^''^'  combined  with  the 

quarts  of  water,  ^  pounds  of Ta W  w^^^^^^^  for  dyeing  by  dissolving  in  9 

sal  ammoniac,  and  10  pounds  of  gumirlbt     ^  ""^  ^'"^^^  ^^^^er,  2  pounds  of 

has  br  ^^^^^^^^  th-e  Pound^of  catechu  in  fine  powder,  which 

heat,  till  It  be  reduced  iy  one  tenth  alow7<if^ll?i      '  ^2  ^^  evaporated  at  a  gentle 

To  9  quarts  of  the  above  prepared  catrchu   Zl"'  ^".^  t'*  ^'^^  ^"^  "«^- 
ammoniac,  4  of  gum  arabic,  5  of  pipe  clav  and  ?  nf  T  ^?  ^%  ^^^'^  ^i  pounds  of  sal 

Introducing  into  this  nreDar/tinn  Lu^'  t-x.     ^^  "'*'''*^^  ®f  <^opper. 
modified,  and^ther  cXpfprXee^d^^  f  ^*^^"'  ^^^  ^^-^^  "^-7  l>e 

quarts  of  acetate  of  protoxide  of  iron  at  1^  R  In^  o  ^°^  ^^'^  ^.'l"^*'*^  «^  the  above  6 
to  9  quarts  of  the  above  catechu  preVraion   1*4  o^^^^^^^^^  ">' ^^^^^^ 

the  acetate  of  iron  may  ^F  ;  atX^;^'^^^^^^^^^^^  -^y  be  extensively  modified ; 

the  nitrate,  if  the  proportions  of  the  other  Xble  mlf?r  l! '  ? ^  '"^/^^^^^'  «^  «^«^  ^Y 

anpetri^S^^^^^  copper,  fo^ 

^sxx^uirb--^ 

the  colours  of  cate4u  areCeby  rtdereSe;       ^'''^'"^  '^^  "^^^'^"'^^  ^-«t,  »: 

df  t  atumid  r^te^^^  ntftinrthe^t^^  ^^  ^^  °^^'""-  ^^  -e 

colours  are  then  fixed  by  steaming,  or  by^  m^^f  l^l^r^^^^^^ 

boiled,  4i  quarts  of  solution  of  caustTc  soda  Tt  ^  1^  I^^^nds  of  flour,  and  when  it  S 
proportion  of  catechu  without  changtg  the  ratios  Xlf  ^v-  T  ^'  \  ^"''^''"g  '^- 
stances^  stronger  or  fainter  shades  mlv  be  obtaiip!l  K,  f     exist  among  the  other  sub- 

gino{s  pr:;^^^^^^^^^^  o/e>o..-One  of  the  ferru- 

by  addi^ngfo  lOquartsof  SS  about  Jw^^^^  ItismlZ 

very  slow  degrees  in  a  large  vitriol  bottle  and  btr"'  '*!  ""t'^^^  ^^  ^"'P^"*^  <>f  ^^^n  by 
a  portion  of  ammonia  is  formed  Six  d  A  ,  ^  ^  ™"i""^  ^""^"  «^  these  ingredient 
Towards  the  conclusion  the  sSatemusf^^^^  "^"P^^*^  this  compound 

ensue  in  the  thickening  liquoZ  It  is  l^'^j^^^  «^«^^y>  otherwise  frothing  wiU 

density  of  56-  to  57°  I  When  cooled  bd^^^^^^^^^^  ^^^^^  ^^"^r.  andlasa 

It  should  always  be  diluted  to  a  ^trenllTon^^^^^ 

To  dye  with  this  preparation  it  is  to  be  diluted  to  fW  •  i^  ^'  ^^^''''^  ^^'""S  "sed. 
pad<Jing  trough,  where  it  serves  to  imprein^^^^^^^  tL  o-nnr'^'^/'^^'  ^"^  ?"*  ^"t«  the 
transferred  to  the  stove,  where  thev  are  to  h«  ^-  f^^l  uniformly.  They  are  then 
corroding  the  fibres  by  the  red  oxidTof'ron  tL.  ''^'  ^"\°^*  *^  hardness,  for  fear  of 
padding  machine  containing  a  weak  solution' of  eLbonnLJ*''^'^  through  a  peculiar 
qmekhme.   Inproportionastheclothiapassedfh^o^^^^^^^^^^^ 


CALICO  PRINTING. 


345 


gets  neutralized,  it  must  be  refreshed  with  fr^sh  solution  of  soda.  The  cloth  raav  be 
supplied  by  a  soap-bath  ;  and  lastly  by  the  dash-wheel.  If  the  iron  orange  tint  is  not 
sufficiently  deep  by  one  operation,  it  may  be  increased  by  another,  and  also  rendered 
more  uniform.  A  mixture  of  red  muriate  of  iron  and  sal  ammonia  gives  a  good  iron 
dye,  and  with  perfect  safety ;  or  one  of  red  sulphate  and  sal  ammoniac.  Goods  padded 
m  iron  liquor,  dried  and  then  padded  in  a  solution  of  chlorine  containing  a  little  free- 
lime  acquire  a  good  rust  ground.  The  following  prescriptions  serve  as  resist  pastes 
for  these  dyes.  In  9  quarts  of  hot  water  dissolve  5  lbs.  of  the  biarsenate  of  potash,  and 
add  to  the  solution  as  much  carbonate  of  potash  as  to  give  it  a  slight  alkaline  reaction. 
Dividing  thisliquor  into  two  equal  parts,  there  is  to  be  incorporated  with  the  first,  10 
J^nJl  ilf^^'f^^''  .u  \^  ^^«««^!^^,  *^  the  second  4i  lbs.  of  gum  Senegal,  with  5  of  a 
df.  1  '7F'  l^^^^Y"-^  *?  ^«  ^°ited.  This  resist  is  to  a  certain  degree  of  a 
TflTlt  ^f  fi!  ^'  ^'  *?^.[«r^,^i°T  P^'^Pa^ation  cannot  touch  it,  without  setting 
the  fat  acid  of  the  soap  at  hberty  and  preventing  the  entrance  of  the  liquor  into  thi 
pores  01  tne  web.  ^ 

White  resists  on  rust  grounds  are  also  made  with  a  mixture  of  tartaric  and  oxalic 
acids ;  as  also  of  hme  juice.  When  the  iron  oxide  is  fixed,  as  in  the  eenus  avantuSi^ 
muriate  of  tin  is  a  preferable  discharge ;  as  for  example  -  ^         avanturme. 

In  9  quarts  of  water  diffuse  3a  lbs.  of  flour,  1  lb.  of  starch,  and  boil  into  a  paste  • 
and  add  to  2  bs.  of  this  paste,  2  lbs.  of  acid  muriate  of  tin  at  65°  B.  (solutbn  of  salt 
of  tin  m  muriatic  acid.)  This  for  printing  with  the  block.  For  printinTon  the  dis- 
charge paste  by  the  cylinder,  to  2  lbs.  of  the  paste  are  to  be  addedTlbs^f  the  ac^ 
muriate  of  tin  at  65°  k     In  these  preparations  the  combined  action  of  the  muriatic 

notCt^r''''  "'  'Vt  '?? "^"'  \^W]-<^e  the  oxide  of  iron;  but  tlie  pasTeTust 
not  be  left  long  exposed  to  the  air,  otherwise  the  iron  may  become  fixed  by  peroxi- 
dizement  White  discharge  upon  chamois  (a  faint  rust  colour)  is  produced  bv  11  lbs. 
of  gum  arabic  2|  lbs.  of  oxalic  acid,  2  lbs.  of  tartaric  acid,  i  lb.  of  oil  of  vitriol  After 
applying  this  discharge  the  goods  should  not  be  exposed  to  a  high  heat  to  dry  them 
ihe  hrstof  these  two  receipts  tends  to  crystallize,  the  second  to  deliquesce.  It  deserves 
to  be  remarked  that  when  soda  is  employed  to  precipitate  rust  of  iron  upon  goods, 
the  tint  IS  much  deeper  than  it  is  by  lime.  f       &     ^^ 

Of  the  colours  produced  by  the  oxide  of  chronic.— A  preparation  for  this  purpose  is 
made  by  boiling  together  2  lbs.  of  bichromate  of  potash,\nd  4  lbs.  of  muHat^  acid 
The  muriatic  acid  excess  is  to  be  evaporated  off.     For  obtaining  deeper  shades,  arsenic 
acid  is  introduced  m  determinate  proportions;  as  for  example* 

To  9  quarts  of  water,  there  are  added  9  lbs.  of  bichromate  of  potash,  12  of  arsenioos 
acid,  and  20  or  22  lbs.  of  muriatic  acid,  in  order  to  destroy  all  the  chromic  ac  d  an^ 
that  the  chlorine  set  at  liberty  in  contact  with  the  water  and  the  arsenious  acid  may 
transform  the  last  into  arsenic  acid  by  the  oxygen  of  the  decomposed  water.  When 
the  reaction  has  ceased,  a  fine  green  liquor  results,  which  is  to  be  evaporated  to  the 
density  of  60°  or  65°  B.  to  dissipate  the  free  acid;  care  should  be  taken  to  get  rid  of 
the  acid  excess  either  by  a  regulated  heat  or  by  soda.  Many  pieces  of  calico  are  dyed 
a  line  green  by  the  oxide  of  chrome,  and  are  very  fast. 

The  solution  of  muriate  of  chrome,  just  described,  at  a  density  of  45°  B  is  to  be 
thickened  slightly  with  gum,  poured  into  a  padding  machine,  then  dried  carefully  to  aid 
the  fixation  of  the  colour,  and  finally  passed  through  a  weak  bath  of  soda :  to  complete 
the  deposition  of  the  oxide  of  chrome,  ammonia  may  be  substituted  for  the  carbonate 
of  soda.  The  colours  thus  produced  are  pale  green,  or  grey,  but  may  be  deepened  by 
passing  the  cloth  through  a  weak  bath  of  sulphate  of  copper;  it  may  be  deepened  also 
by  mixing  with  arsemc  acid,  and  after  some  days'  repose,  precipitating  the  ai-seniate 
of  chrome  on  the  stuff  by  passing  it  through  a  bath  of  carbonate  of  soda 

0/the  simple  genera  derived  from  oxide  of  manganese.— Thh  colour  is  generally  known 
b^  the  name  of  solitaire  bistre,  and  sometimes  turks-head.     By  impregnatinir  the  cloth 
with  4  neutral  solution  of  acetate  of  manganese,  then  precipitating  the  oxide  with  an 
alkal^  exposing  the  goods  to  the  air  to  favour  the  oxndation,  or  pacing  them  through 
a  bath  of  chlorite  of  lime  the  process  of  the  manganese  dye  may  be  executed.     After 
passing  the  goods  through  the  manganese  bath  over  8  rollers,  to  secure  uniformity  of 
impression,  they  should  be  dried  immediately  in  a  stove.     The  dye-bath  should  contain 
a  small  quantity  of  mucilage  of  gum  arabic.     The  alkali  for  precipitating  the  oxide  of 
manganese  in  the  padding  machine  should  be  caustic,  strong,  and  heated  by  a  steam  pipe 
to  the  boiling  point.     The  strength  of  the  alkaline  solution  should  in  all  cases  be  I40 
B  :  and  for  some  purposes  even  22°  B.     This  alkaline  strength  is  requisite  to  seize  the 
fibre  the  instant  of  the  tissue  entering  tiie  alkaline  bath,  and  to  force,  by  the  contraction 
which  it  causes,  the  oxide  of  manganese  to  remain  within  it  till  the  oxidation  is  com- 
pleted.    It  is  obvious  that  the  bath  must  be  kept  up  by  fresh  alkali.     The  two  last 
cylinders  of  the  frame  should  be  heavily  loaded,  so  as  to  render  the  goods  as  dry  as  pos- 
sible.  A  passage  through  solution  of  chlorine  is  in  general  advantageous  to  complete  the 
Vol.  L  2  Y 


346 


CALICO  PRINTING. 


CALICO   PRINTING. 


347 


ill! 


oxidation  of  the  manganese.  A  more  economical  process  would  be  to  add  an  eqnira- 
lent  of  sal  ammoniac  to  an  equivalent  of  chlorman^anese,  and  to  make  the  solution 
alkaline  with  a  little  ammonia.  The  goods  padded  m  this  liquor  might  be  dried  with- 
out risk  of  injury,  and  be  then  finished  in  the  baths,  fii*st,  of  milk  of  lime,  and  next  of 
chlorine :  or  at  once  in  a  mixture  of  the  two. 

The  shades  with  a  foundation  of  manganese  are  often  modified  in  various  ways ;  as 
by  adding  to  the  mixture  a  certain  quantity  of  acetate  of  lead,  whence  results  chlorlead ; 
while  in  passing  into  the  solution  of  chlorlime,  the  lead  is  transformed  into  peroxide, 
whose  brownish  yellow  added  to  the  tint  of  the  manganese  produces  a  yellowish  cast 
and  a  velvety  aspect.  Sometimes  some  salts  of  iron  are  added,  which  decomposed  and 
peroxidized  along  with  the  salts  of  manganese  give  shades  which  resemble  aventurine, 
the  more  closely  the  larger  the  proportion  of  iron. 

Prussian  blue. — Its  white  discharge  is  effected  upon  calico,  by  preparing  a  rust 
ground  of  a  proper  tint  for  producing  with  acidulated  ferrocyanure  of  potash  the  desired 
blue  shade.  Into  either  the  mordant  or  into  the  ferrocyanide  put  the  quantity  of  muriate 
of  tin  necessary  to  give  the  blue  its  purest  tint.  The  discharge  is  performed  usually  at 
two  operations,  by  the  first  the  ferrocyanure  is  decomposed  by  a  powerful  base  (potash), 
which  forms  a  yellow  cyanure,  and  liberates  the  iron  oxide ;  by  the  second,  we  remove 
the  iron,  by  the  mtervention  of  an  acid.  But  the  success  of  this  second  operation  depends 
on  the  energy  of  the  first,  and  especially  upon  the  washings  which  follow  it,  and  which 
ought  to  have  carried  off  the  whole  of  the  ferrocyanure ;  otherwise  the  presence  of  the 
acid  would  regenerate  the  blue  upon  the  points  which  should  remain  clear  of  it  The 
pieces,  after  being  dried  and  calendered,  receive  an  impression  with  caustic  potash  ley 
(thickened  with  gum),  and  which  in  every  case  should  mark  at  least  14°  B.,  in  order  to 
make  the  texture  contract  or  shrink  suitably,  and  furnish  a  precise  or  sharp  print.  It 
is  then  to  be  rinsed  and  washed  in  the  dash-wheel  so  as  to  clear  away  every  thing  but 
the  oxide  of  iron  from  the  cloth  upon  all  points  touched  by  the  alkali.  The  piece  is 
then  immersed  in  water  acidulated  with  muriatic  or  sulphuric  acid,  till  the  oxide  of 
iron  has  entirely  disappeared.  By  adding  to  the  potash  a  little  tartrate  of  potash,  the 
oxide  of  iron  from  the  Prussian  blue  enters  into  combination  with  the  tartaric  acid, 
and  goes  off  in  a  great  measure  with  the  subsequent  washings. 

This  style  may  also  be  executed  upon  silk  and  woollen  goods,  but  great  precaution 
must  be  used  to  avoid  injuring  the  texture  by  the  strong  alkaline  ley.  Silk  handker- 
chiefs are  first  passed  for  about  thirty  minutes  through  a  bath  of  nitrate  of  iron  of  4°  B., 
then  through  running  water,  next  through  the  dash-wheels.  They  are  next  put  in  a  bath 
of  clear  and  cold  lime  water,  in  order  to  decompose  the  salt  of  iron,  and  to  fix  the  oxide 
upon  the  stuff.  It  is  now  rinsed,  and  sent  through  the  dash-wheel  before  proceeding 
to  dye  it;  which  is  done  by  passing  it  through  a  tub  sharpened  with  a  little  sulphuric 
acid,  and  containing  a  small  quantity  of  ferrocyanure  of  potash.  After  working  the 
cloth  fifteen  or  twenty  minutes  in  this  bath,  a  little  more  acid  and  ferrocyanure  are  in- 
troduced, and  the  passage  of  the  cloth  is  resumed  during  fifteen  minutes  more,  which 
time  is  usually  sufficient  to  produce  the  desired  tint.  It  might  be  better  to  decompose 
previously  in  a  separate  vessel  the  ferrocyanure  by  adding  to  one  equivalent  of  it  in  so- 
lution two  equivalents  of  sulphuric  acid.  The  mixture  of  sulphate  of  potash  and  fer- 
rocyanic  acid  thence  resulting,  should  be  poured  by  degrees  into  the  dyeing  bath,  till 
the  due  tint  is  produced,  or  the  oxide  of  iron  on  the  cloth  becomes  saturated.  When 
the  ground  has  been  thus  dyed,  the  discharge-printing  may  be  proceeded  with  as  already 
directed.  Muriate  of  tin  may  sometimes  be  substituted  for  acid,  for  acidifying  the 
ferrocyanure  of  potash  in  the  act  of  dyeing. 

By  substituting  oxide  of  copper  for  oxide  of  iron,  a  crimson  colour  is  obtained  with 
the  ferrocyanure. 

Saxon  blue  ;  solution  of  indigo  in  sulphuric  acid. 
This  blue  dye  is  given  by  passing  the  cloth  mordanted  with  base  of  alumina  through 
the  indigo  solution  of  a  proper  degree  of  strength.     It  enters  also  as  an  ingredient  in 
certain  pistachio  green  dyes. 

The  genera  of  styles  derived  from  madder  are  numerous. 
Plain  grounds  upon  ordinary  cloth ;  albuminous  mordant, 
do.  ;  iron  mordant, 

do.  ;  mordant  of  alumina  and  iron, 

do.  ;  mordant  of  chrome, 

Plain  printing;  white  reserve  with  mordants  of  alumina,  iron,  or 
chrome, 
do.  white  discharge  upon  common  madder  dye. 

do.  white  discharge  on  oiled  cloth,  with  madder  dye; 

mordants  of  iron  (violet  and  lilac)  upon  the  cy- 
linder. 


There  are,  1. 
2. 
8. 
4. 
6. 

e. 


White  grmmd;  printing  with  alumina  mordant  for  red  and  pink  upon  the  cylinder 

ir/Ai<e  Vrounrf;  printing  on  mordants  of  alumina  and  iron. 

White  ground;  printing  on  mordants  ;  for  red,  violet,  puce,  black  ;  a  binary,  three- 
fold, and  fourfold  union  of  these  colours. 

White  around ;  printing  on  mordants,  for  red,  violet,  or  puce ;  separate  or  combined ; 
by  the  block  or  Perrotine.  Plain  ground  upon  oiled  mordanted  cloth :  with  alumina 
of  iron.     Turkey  red,  or  violet  oiled.  ^  -i  j    i  *u 

White  ground;  printing  with  mordant  of  iron  and  alumina  upon  oiled  cloth. 

The  colours  obtained  directly  by  madder  are  red  and  its  gradations,  pale  red&ndptnk, 
which  have  always  an  aluminous  mordant  for  their  base  ;  black  and  its  gradations :  deep 
violet,  light  violet,  and  lilac,  of  which  the  base  is  pyrolignite  of  iron,  or  the  common 
acetate  ;  red  and  deep  puce,  whose  mordant  is  a  mixture  of  aluminous  and  iron  hquors ; 
lastly,  the  ventre  do  biclie  fixed  by  means  of  the  oxide  of  chrome. 

In  ever}-^  print  wort,  three  principal  mordants  are  prepared  beforehand  in  a  certain 
state  of  concentration,  which  are  diluted  when  wanted  with  water,  but  more  frequently 
with  gum-water,  and  vinegar.  j-      i     j 

A.  Mordant  for  red  is  made  with  100  quarts  of  boiling  water  in  which  are  dissolved 
150  pounds  of  alum;  and  then  150  pounds  of  pyrolignite  of  lead  added. 

B.  Mordant  for  red, 

100  quarts  of  watef,  in  which  are  dissolved,  , ,      ,      ,  j      , 

70  pounds  of  alum,  48  pounds  of  acetate  or  pyrolignite  of  lead,  2t  pounds  of  cap- 
bonate  of  soda  (crystals^  4  pounds  of  muriate  of  soda. 

C.  Mordant  for  red.  ,.      i     j  ' 
In  100  quarts  of  boiling  water  are  to  be  dissolved, 

66  pounds  of  alum ;  and  then  to  be  added, 
66  pounds  of  pyrolignite  of  lime,  and 
5  pounds  of  soda  carbonate  in  crystals. 

Red  Mordant.  .  -,    .,.  .  j  j*     t 

To  66  quarts  of  decoction  of  logwood,  add  100  quarts  of  boiling  water;  and  dissolve 
in  this  mixture  67  pounds  of  alum,  56  pounds  of  pyrolignite  of  lead,  and  6  pounds  of 

Otiier  mordants  are  made  of  like  quantity  in  which  decoction  of  quercitron  is  put 
along  with  chlorzinc;  some  into  which  an  admixture  of  chalk  is  made,  others  with  an 
admixture  of  acetate  of  lead,  and  some  chalk. 

The  blacks  are  made  by  strong  mordants,  with  some  salt  of  copper. 

Cochineal  is  used  much  in  the  same  way  as  for  the  madder  printing  and  discharge^ 
and  the  mordants  are  much  the  same  ;  Brazil  wood  printing  is  of  like  nature :  as  also 
logwood  dyes.  The  styles  of  printing  derived  from  mixed  colours  are  innumerable  ;  but 
all  proceed  on  the  principles  already  laid  down.  ..       ^   ^u 

Calico  Printing  by  Steam.— K\\  textile  fibres  do  not  attract  colouring  matters  to  them 
with  an  equal  poWer,  but  they  may  be  rendered  capable  of  acting  with  more  or  less  force 
bv  adventitious  aids,  of  which  the  use  of  steam  conjoined  with  the  salts  or  oxides  of  tin 
forms  two  of  the  most  remarkable.  Tlie  muriate  or  chloride  of  tin  is  decomposed  by  the 
action  of  water  into  muriatic  acid  and  oxide  of  tin,  the  first  of  which  is  expelled  by  the 
heat  of  steam,  or  it  may  be  neutralized  by  the  intervention  of  a  saturating  substance ; 
while  the  second  is  never  set  at  liberty  in  presence  of  cloth  without  making  such  a  body 
with  it  as  to  resist  all  the  means  of  discharge  employed  for  the  removal  of  the  other 
substances,  and  without  fixing  at  the  same  time  on  the  fibres  the  colouring  matter  pre- 
viously mixed  with  it.  The  same  reasoning  may  be  applied  to  the  muriate  of  alumina. 
Oxalic  acid  fulfils  at  once  the  functions  of  these  two  saline  compounds.  It  is  an  agent 
employed  to  remove  the  oxides  or  the  mordants ;  and  this  application  is  based  upon  the 
affinity  which  it  has  for  alumina  and  iron.  When  deposited  upon  a  mordanted  cloth, 
it  may  either  make  the  whole  of  the  oxide  disappear,  if  used  in  sufficient  quantity,  or  it 
may  /estore  it  in  whole  or  in  part  eventually,  if  the  contact  be  prolonged  at  the  ordinary 
teninerature  or  immediately  when  exposed  to  steam.  It  is  thereby  easy  to  explain 
certain  phenomena,  since  by  its  energetically  dissolving  the  oxides,  it  preserves  them 
in  solution  during  the  whole  period  of  printing  them,  and  then  quits  them  under  the  in- 
fluence of  a  steam  heat ;  and  leaves  them  on  the  cloth  in  all  their  properties  when  alone. 
It  is  to  this  peculiar  property  of  the  oxalic  acid  that  we  must  ascribe  the  solidity  ot 
certain  topical  blacks,  for  which  it  has  been  long  employed.  «  •.    «r  vi.:„ 

The  tartrates  and  tartaric  acid  concur  also  to  the  same  end ;  but  the  alhnity  ol  tnis 
acid  for  the  bases,  and  the  force  with  which  it  masks  them,  render  its  application  more 
limited  than  the  oxalic  acid.  It  is  useful  for  effecting  displacements,  and  for  preserving 
oxides  in  solution,  so  as  to  insure  homogeneity  to  colours.  •  i       «. 

Acetic  acid  enters  also  as  an  ingredient  into  steam  prmtmg ;  possessing  a  solvent 

2Y2 


i 


348 


CALOMEL. 


i 


i     1 


I'i 


:i!!ii 


power  different  from  the  other  acids,  and  being  applicable  in  a  state  of  conceutration 
without  corroding  the  tissues,  it  is  applied  in  cfrcumstances  where  iubrnces  of  a 
more  or  less  resinous  nature  need  to  be  kept  in  solution  in  order  to  being  printed  on 
whilst  quitting  under  the  influence  of  heat  the  bases  with  which  it  is  associated  it  allowi 
them  to  contract  an  intimate  union  with  the  stuffs.  The  salts  of  copper  and  chromate 
of  potash  are  employed  to  perform  the  oxidizing  power  of  the  abseit  air. 

The  colours  fixable  hy  steam,  after  having  been  suitably  thickened,  are  to  be  printed 
with  the  nicety  appropriate  to  each,  and  the  goods  covered  with  them  should  be  previ^ 
ouslyexposedforsome  time  to  a  damp  atmosphere.  In  the  steaming  process,  thegoods 
are  coiled  round  a  perforated  hoi  ow  cylinder  charged  with  steam  by  a  central  pipror 
^ev  are  exposed  on  frames  in  single  pieces  without  Sutual  contact  in  wooden  cases  mied 
Z  I'nr""- Wi?^''  Ta  ^^  ^^^  to  prevent  the  dropping  down  of  condensed  steam  upon 
the  goods.  When  rolled  np  in  a  cylindrical  form,  they  a?e  wrapped  in  blanket  stuff  Tf 
late  years  contrivances  have  been  made  to  keep  the  cloth  moving  in  the  steam  so  as  to 

?.d,  nrnl  rr- '?f  *^*\'  ^T^  ^^  ^^"  operatoi-s.    'But  in  all  cases  there  should  be  a 

[t  ?o  blfh  J.l  Jl^  ^  ^  t^'^'^  'I'^'^f  ^"^^^"'^^  q"«^i*y.  ^1"«1^  i«  secured  by  causing 

CALOMFT^    7r^F^  *  '*S^*"J?  °^  ^^^ST  ^>'i°«  ^'^  the  bottom  of  the  case.^  ^ 

i^ALOMEh.      (Chlorure   de  Mercure,   Fr. ;     Vermsstes    Quecksilber,    Germ)      The 

mild  protochloride  of  mercury.     The  manufacture  of  this  substance  upok  the  g^eit  scale 

TLrt  rft,ri;\'M'  ^"^-V  J^  ^^^"P^«*  ^"^  "^^^^  <!<-«*  c^onsists  ?n  mi^ng 
l-2Lv9/.^«  l-^^^^''/-''''.i'''^^.  ^  P^"*  ^^P"'-^  citric  acid,  of  sp.  grav.  from 
fV!  r  •/;  ^""^  '"^  <i'§esting  the  mixture  till  no  more  metal  can  be  diLlved,  or  tm 
the  liquid  has  assumed  a  yellow  colour.  At  the  same  time  a  solutioHf  1  nart  of 
comn^on  salt  is  made  in  32  parts  of  distilled  water,  to  whTch  a  iTttJe  muriatic  S  is 

tfon  ^C^t wo  ::it '"'1 '"  "' K^^  '^^  ^S^'^"^  P«^"^^^  -  ^^-'^  -ith  thTmercurid  ^^^^^ 
tion  Ihe  two  salts  exchange  bases,  and  a  protochloride  of  mercury  precipitates  in  a 
white  powder,  which  after  being  digested  for  some  time  in  the  acidulous  Sernaten? 
bquor,  IS  to  be  washed  with  the  greatest  care  in  boiling  water,  -nie  circumsS^^ 
may  injure  the  process  are  the  following  :_l.  When  less  mercury  is  empToyedtha^^^^^^ 
acid  can  dissove  there  is  formed  a  deuto-nitrate  of  mercur^^  which  S some  corrosive 
jublimate  with  the  common  salt,  and  causes  a  proportiona?de7airationS 

curv  fth^ow:  ^own't^- ?'"'  ""'ll'  ™^™^"S4  ""^^"^  *^^-'  ^^^  subntrate  of me^ 
cur>  IS  thrown  down,  which  cannot  be  removed  by  washing  and  wliich  e-ives  u  novinna 

S^dlagerr  '"'  "^'^'^  '^^'"''  "^^  "^^'  prescribed^  the  a  W^fo^uir  ob^^! 
^The  second  manner  of  manufacturing  calomel  is  to  grind  very  carefully  4  parts  of 
corrosive  sublimate  (bichloride  of  mercury)  with  3  paits  of  quicLlver^ing TlittL 
water  or  spirits  to  repress  the  noxious  dust  during  the  trituration.  The  mas!  L  then 
mtroduced  into  a  glass  globe,  and  sublimed  at  a  temperature  gradually  rmW     The 

?rme\  "l^rf^n"  -i^V^^^f  "'^^^'^^i^^'  ""^  ^«--*«  ''  int^the  ploc  lorid^r 
calomel  The  following  formula,  upon  the  same  principle,  was  recommended  to  the 
chemical  manufacturer  in  Brande's  Journal,  for  July  1818 '—  ^'''^'^^^^^e*!  ^o  lUe 
"Prepare  an  oxysulphate  of  mercury,  by  boiling  25  'pounds  of  mercury  with  35  pounds 
of  sulphuric  acid  to  dryness.     Triturate  31  pounds  of  this  dry  salt  With  20  poEnds  4 

Zx^Tlj^Cr^'r^l^'  ^^"^.^^^^  ^^TP^^^'  ^"^  *^^"  -^^  17  pounds  of^ommon 
5^  an7i«  5  ''  ^  ^^  thoroughly  mixe<(  and  sublimed  in  earthen  vessels.     Betv^en 

fn  the  usua^w^?"  '?^''  calomel  are  thus  produced:  it  is  to  be  washed  andlevTglteS 
n™inKof  ^  ^'  ;,  ^^  ^^^^^  '^  *^*  P^^^^"^  "^e*^  ^t  Apothecaries'  Hall,  London.  The 
oxysulphate  is  made  in  an  iron  pot;    and  the  sublimat'ion  is  performed  in  earthen  veL- 

iW  Jv"2t^^''''y^T^  "'  '^^'  of  calomel  should  be  separated  from  the  accompany- 
iofivrs^bCate.'  ""  ""'"'''^  ^^'  ^^^'"^  '^^  consists  of  mercury  mixed  with  co^- 

n^fj!  'Tk 'T  ™«^^fi?^*^«n  «f  the  latter  process,  for  which  a  patent,  now  expired,  was 
TurfacP  of  Z.f  ■  "^'T  •'  T''''  ^"  conducting  the  sublimed  vapou,^'  over  an^extS 
r?o^  artiol  ?n  I  "?"*^7^\^,^  ^  ««^/re<i  cistern.     Th«  calomel  thus  obtained  is  a  supe 
'klr^^       an  impalpable  powder,  propitious  to  its  medical  efficacy.  ^ 

nnnn ir^'n^f?  T   "^^7 ^  sublimate  in  calomel  is  easily  detected  by  digesting  alcohol 
upon  it,  and  testing  the  decanted  alcohol  with  a  drop  of  caustic  potish,  when  the  cha 

S>te^ct\ubn^^^^^^^^^^^         ^""^^-'''^  r''  f^'}. ''  '^'7  ''  ''^'  P--"-«  -''^e  present 
10  detect  subnitrate  of  mercury  in  calomel,  digest  <filute  nitric  acid  on  it,  and  Wst  the 

acid  with  potash,  when  a  precfpitate  will  fall  In  case  of  that  contamination     ^  it  is 

i\f^::;:c^T^:^^^^^^^      ^  ^-^^^-^  ^^  ^  -^  ^-<i-  ^ge,  it.  punty^^hJ 

118  parts  of  calomel  contain  100  of  quicksilver 

A  patent  was  obtained  in  September,  1841,  by  Anthony  Todd  Thomson,  M.  D., 


CALORIFERE  OF  WATER. 


349 


for  an   improved  method   of  manufacturing  calomel  and  corrosive  sublimate,   as 
follows : — 

This  invention  consists  in  combining  chlorine  in  the  state  of  gas  with  the  vapour  of 
mercury  or  quicksilver,  in  order  to  produce  calomel  and  corrosive  sublimate. 

The  apparatus  employed  consists  of  a  glass,  earthenware,  or  other  suitable  vessel, 
mounted  in  brick-work,  and  communicating  at  one  end  with  a  large  air-tight  chamber, 
and  at  the  other  end,  by  means  of  a  bent  tube,  with  an  alembic,  such  as  is  generally 
used  in  generating  chlorine  gas.  The  alembic  is  charged  with  a  mixture  of  common 
salt,  binoxide  of  manganese  and  sulphuric  acid,  or  of  binoxide  of  manganese  and  mu- 
riatic acid,  in  order  to  produce  chlorine  gas. 

The  mode  of  operating  with  this  apparatus  is  as  follows: — ^A  quantity  of  mercury 
or  quicksilver  is  placed  m  the  glass  vessel,  and  the  temperature  of  the  same  is  raised  to 
between  350°  and  660°  Fahr.,  by  means  of  an  open  lire  beneath.  The  chlorine  gas,  as 
it  }B  generated,  passes  from  the  alembic  through  the  bent  tube  into  the  glass  vessel,  and 
there  combining  with  the  vapour  of  the  mercury,  forms  either  corrosive  sublimate  or 
calomel,  according  to  the  quantity  of  chlorine  gas  employed. 

The  product  is  found  at  the  bottom  of  the  air-tight  chamber,  and  may  be  removed 
from  the  same  through  a  door,  when  the  operation  is  finished. 

According  to  the  patent  of  Mr.  Josiah  Jewell,  the  vapour  of  calomel  was  to  be 
transmitted  into  a  vessel  containing  water,  in  order  to  condense  it  at  once  into  an 
impalpable  powder.  But  this  process  was  beset  with  many  difficulties.  The  vapour 
of  the  calomel  was  afterwards  introduced  into  a  large  receiver,  into  which  steam  was 
simultaneously  admitted ;  but  this  plan  has  also  been  found  to  be  precarious  in  the 
execution.  Tne  best  way  is  to  sublime  the  calomel  into  a  very  large  chamber  from  an 
iron  pot,  in  the  same  way  as  the  flowers  of  sulphur  are  formed.  The  great  body  of  cool 
air  serves  to  cause  the  precipitation  of  the  calomel  in  a  finely  comminuted  state.  It  la 
afterwards  washed  with  water,  till  this  is  no  longer  coloured  by  sulphuretted  hydrogen. 
CALORIC.  The  chemical  name  of  the  power  or  matter  of  heat. 
CALORIFERE  OF  WATER.  {Caloriflre  d*eau,  Fr.;  Wasser-Heitzung,  Germ.) 
In  the  Diclionnaire  Technologique,  vol.  iv.,  published  in  1823,  we  find  the  following  de- 
scription of  this  apparatus,  of  late  years  so  much  employed  in  Great  Britain  for  heating 
conservatories,  &c.,  by  hot  water  circulating  in  pipes  : — 

"  This  mode  of  heating  is  analogous  to  that  by  stove-pipes  :  it  is  effected  by  the  circu- 
lation of  water,  which,  like  air,  is  a  bad  conductor,  but  may  serve  as  a  carrier  of  caloric 
by  its  mobility.  AVe  may  readily  form  an  idea  of  the  apparatus  which  has  been  employed 
for  this  purpose.    We  adapt  to  the  upper  part  of  either  a  close  kettle,  or  of  an  ordinary 

cylindric  boiler  a,  fig.  319,  a  tube  b,  which  rises  to  a  certain 
height,  then  descends,  making  several  sinuosities  with  a  gentle 
slope  till  it  reaches  the  level  of  the  bottom  of  the  boiler,  to  whose 
lowest  part,  as  that  which  is  least  heated,  it  is  fitted  at  c. 
At  the  highest  point  of  the  tube  f  we  adapt  a  vertical  pipe,  des- 
tined to  serve  as  an  outlet  to  the  steam  which  may  be  formed  if 
the  temperature  be  too  much  raised :  It  serves  also  for  the  es- 
cape of  the  air  expelled  from  the  water  by  the  heat :  and  it  per- 
mits the  boiler  to  be  replenished  from  time  to  time  as  the  water 
is  dissipated  by  evaporation ;  la«:tly,  it  is  a  tube  of  safety. 

"The  apparatus  being  thus  arranged,  and  all  the  tubes  as 
well  as  the  boiler  filled  with  water,  if  we  kindle  fire  in  the  srate 
D,  the  first  portions  of  water  heated,  having  become  specifically 
lighter,  will  tend  to  rise  :  they  will  actually  mount  into  the  up- 
per part  of  the  boiler,  and,  of  course,  enter  the  tube  b  f  :  at 
the  same  time  an  equivalentquantilyof  water  will  re-enter  the 
boiler  by  the  other  extremity  c  of  the  tube.  We  perceive  that 
these  simultaneous  movements  will  determine  a  circulation  in 
the  whole  mass  of  the  liquid,  which  will  continue  as  long  as  heat  is  generated  in  the  fire- 
place ;  and  if  we  suppose  that  the  tubes,  throughout  their  different  windings,  are  applied 
against  the  walls  of  a  chamber,  or  a  stove-room,  the  air  will  get  warmed  by  contact  with 
the  hot  surfaces ;  and  we  may  accelerate  the  warming  by  multiplying  these  contacts  in 
the  mode  indicated. 

"This  calorifere  cannot  be  employed  so  usefully  as  those  with  heated  air,  when 
It  is  wished  to  heat  large  apartments.  In  fact,  the  passage  of  heat  ihroush  metallic 
plates  is  in  the  ratio  of  the  difference  of  temperatureandquantity  of  the  heating  surfaces. 
In  the  present  case,  the  temperature  of  the  water,  without  pressure,  in  the  tubes,  must  be 
always  under  100°  C.  (212°  F.),  even  in  those  points  where  it  is  most  heated,  and  less 
still  in  all  the  other  points,  while  the  temperature  of  the  flues  in  air  stoves,  heated  directly 
by  the  products  of  combustion^  may  be  greatly  higher.    In  these  stoves^  also,  the  pipef 


%50 


CALOTYPE. 


CAMPHOR. 


351 


may  without  inconvenience  have  a  large  diameter,  and  present  consequently  a  large  heat* 
ing  surface ;  whereas,  with  the  water  calorij^re,  the  pressure  exercised  by  liquid  upon 
the  sides  of  the  tubes  being  in  the  ratio  of  the  surfaces,  we  are  obliged,  in  order  to  avoid 
too  great  pressure,  to  employ  a  multitude  of  small  tubes,  which  is  expensive.  Lastly,  if 
the  hot-waler  circulation  is  to  be  carried  hish,  as  may  be  often  necessary  in  lofty  build- 
ings, the  pressure  resulting  from  the  great  elevation  would  call  for  proportional  thickness 
in  the  tubes  and  the  boiler  :  for  these  reasons,  and  others  which  we  shall  slate  in  treating 
of  heating  by  steam,  it  appears  that  water  cannot  be  advantageously  substituted  for  air 
or  steam  in  the  applications  above  stated ;  yet  this  mode  of  heating  presents  very  decided 
advantages  where  it  is  useful  to  raise  the  temperature  a  small  number  of  degrees  in  a 
uniform  manner."    See  Incubation,  artificial. 

"  M.  Bonnemain  applied,  with  much  success,  these  ingenious  processes  of  heating 
by  the  circulation  of  water,  to  maintain  a  very  equal  temperature  in  hot-houses  (serres- 
chattdes),  in  stoves  adapted  to  artificial  incubation,  and  in  preserving  or  quickening  vege- 
tation within  hot-houses,  or  outside  of  their  walls,  during  seasons  unpropitious  to  horti- 
colture. 

"  Since  the  capacity  of  water  for  heat  is  Very  great,  if  the  mass  of  it  in  a  circulation- 
apparatus  be  very  considerable,  and  the  circulation  be  accelerated  by  proper  arrangements, 
as  by  cooling  the  descending  tube  exterior  to  the  stove- room,  we  may  easily  obtain  by  such 
means  a  moderately  high  and  uniform  temperature,  provided  the  heat  generated  in  the 
fire-place  be  tolerably  regular.  We  may  easily  secure  this  essential  point  by  the  aid  of 
the  fire-regulator,  an  instrument  invented  by  M.  Bonnemain,  and  which  is  described  un- 
der the  article  Incubation,  because  there  its  use  seems  to  be  indispensable." 

From  the  above  quotation,  and,  more  especially,  from  the  evidence  adduced  in  the  ar- 
ticle Incubation,  we  see  how  little  claim  the  Marquis  de  Chabannes,  or  any  of  his  fol- 
lowers, can  have  to  invention  in  their  arrangements  for  heating  apartments  by  the  calorific 
motions  of  the  particles  of  water,  enclosed  in  pipes  of  any  kind. 

CALOTYPE  is  the  name  given  by  Mr.  Fox  Talbot  to  the  ai-t  invented  by  hira,  of 
making  pictures  on  paper  or  other  such  surfaces  by  the  agency  of  light.  It  is  merely 
a  modified  kind  oi  photography.  The  processs  is  as  follows: — Dissolve  100  grains 
of  crystallized  nitrate  of  silver  in  6  ounces  of  distilled  water,  and  brush  over  the  paper 
(Whatman's  sized  post  answers  well)  with  a  soft  brush  on  one  side  only  with  this 
solution,  and  mark  the  side.  When  nearly  dry,  dip  it  into  the  solution  of  iodide  of 
potassium  (for  only  a  few  minutes),  containing  500  grains  of  that  salt  dissolved  in  a 

Eint  of  water.     As  soon  as  the  paper  is  completely  imbued  with  this  solution,  it  should 
e  immediately  washed  in  distilled  water,  drained,  and  hung  up  to  dry.    This  paper  is 
to  be  kept  for  subsequent  use  in  a  portfolio,  and  carefully  secluded  from  light 

Next  dissolve  100  grains  of  silver-nitrate  in  2  ounces  of  distilled  water,  and  add  to 
the  solution  one-sixth  of  its  volume  of  strong  acetic  acid.  Keep  this  solution  in  th^ 
darL  Make  a  saturated  solution  of  gallic  acid  in  distilled  water.  When  it  is  re- 
quired to  make  a  calotype  picture,  the  two  liquids  last  described  are  to  be  mixed  in 
equal  quantities,  but  only  so  much  as  is  needed  for  the  operation.  With  this  gallo- 
nitrate  of  silver  a  sheet  of  the  silver  iodide  paper  is  to  be  washed  over  upon  its  marked 
side  with  a  soft  brush,  an  operation  to  be  performed  by  candle-light.  After  half  a 
minute,  the  paper  being  dipped  in  water,  and  dried  lightly  by  pressure  between  folds 
of  blotting  paper,  becomes  so  exceedingly  sensitive  to  light  as  to  take  a  pictorial  im- 
pression in  the  camera  in  a  space  varying  from  one  second  to  five  minutes,  according 
to  the  brightness  of  illumination.  The  camera  should  be  mounted  with  a  meniscus 
lens,  in  an  adjustable  tube,  so  as  to  throw  the  image  of  the  object  to  be  calotyped  upon 
a  vertical  plate  of  roughened  glass,  in  the  posterior  side  or  wall  of  the  wooden  box. 
Whenever  the  focus  is  correctly  adjusted,  the  glass  is  withdrawn,  and  replaced  by 
sliding  in  a  groove  a  frame  with  the  prepared  sheet  of  paper  fixed  flat  upon  it,  the  pre- 
pared side  towards  the  lens,  but  screened  from  light  by  a  card  or  thin  board.  The 
telescope,  which  has  been  invented  for  calotype  purposes,  by  Dr.  Petzval  and  M. 
Voigtlander,  of  Vienna,  is  recommended,  in  preference  to  all  others,  by  Mr.  Talbot, 
especially  for  taking  portraits. 

ITie  paper,  after  exposure  for  the  due  time  in  the  camera,  is  to  be  again  covered 
from  the  light,  taken  out,  and  subjected  to  another  process ;  for  as  yet  it  has  no  picto- 
rial appearance.  To  bring  out  this  effect,  it  must  be  washed  with  the  gallo-nitrate  of 
silver,  and  then  be  gently  warmed.  In  a  few  seconds  the  portions  of  the  paper  upon 
which  the  light  has  acted  will  begin  to  darken,  and  eventually  grow  quite  black, 
while  the  rest  of  the  paper  retains  its  original  hue.  Even  though  the  pictorial  im- 
pression be  very  faint,  it  may  be  brought  out  by  a  second  application  of  the  same  solu- 
tion. The  operator  should  watch  the  gradual  development  of  the  tints ;  and  when 
it  is  sufficient,  he  should  fix  them  by  dipping  the  paper  in  water,  drying  it  slightly 
with  blotting  paper,  then  washing  it  over  with  a  solution  of  bromide  of  potassium 


containing  100  grains  of  that  salt,  dissolved  in  8  or  10  ounces  of  water.  Strong  brine 
will  also  answer,  but  not  so  well  Similar  calotype  pictures  may  be  made  by  using 
the  bright  light  emitted  from  lime  ignited  by  the  oxy-hydrogen  flame ;  as  is  practised 
in  making  the  Daguerreotype  portraits  at  night. 

In  all  the  photographic  pictures  the  lights  and  shades  of  the  object  are  reversed ; 
but  they  may  be  made  conformable  to  nature  by  rendering  the  pa^er  transparent  with" 
white  wax  scraped  upon  its  back,  melting  this  in  by  rubbing  it  with  a  hot  smoothing- 
iron,  after  it  is  placed  between  two  sheets  of  common  paper,  then  laying  it  upon  paper 
imbued  with  bromide  of  potassium,  and  exposing  it  to  sunshine.  Portraits  are  best 
taken  by  means  of  a  lens,  whose  focal  length  is  3  or  4  times  only  greater  than  the 
diameter  of  the  aperture.    (See  Photography.) 

CAMBRIC.  {Batiste,  Fr. ;  Kammertuch,  Germ.)  A  sort  of  very  fine  and  rather 
thin  linen  fabric,  first  made  at  Cambray.  An  excellent  imitation  of  this  fabric  is  made 
in  Lancashire,  woven  from  fine  cotton  yarn  hard  twisted.  Linen  cambric  of  a  good 
quality  is  also  now  manufactured  in  the  United  Kingdom  from  power-spun  flax. 

CAMLET,  or  CAMBLET.  A  light  stuff,  much  used  for  female  apparel.  It  is 
made  of  long  wool  hard  spun,  sometimes  mixed  in  the  loom  with  cotton  or  linen  yarn. 
CAMPHOR,  OR  CAMPHIRE.  This  immediate  product  of  vesretation  was  known  to 
the  Arabs  under  the  names  of  kamphur  and  kaphur,  wiience  the  Greek  and  Latin  nam* 
camphora.  It  is  found  in  a  great  many  plants,  and  is  secreted,  in  purity,  by  several  lau- 
rels ;  it  occurs  combined  with  the  essential  oils  of  many  of  the  labiacce  ;  but  it  is  extract- 
ed, for  manufacturing  purposes  only,  from  the  Laurus  camphora^  which  abounds  in  China 
and  Japan,  as  well  as  from  a  tree  which  grows  in  Sumatra  and  Borneo,  called,  in  the 
country,  Kapour  barros,  from  the  name  of  the  place  where  it  is  most  common.  The  cani- 
phor  exists,  ready  formed,  in  these  vegetables,  between  the  wood  and  the  bark ;  but  it 
does  not  exude  spontaneously.  On  cleaving  the  tree  Laurus  sumalrensisy  masses  of  pure 
camphor  are  found  in  the  pith. 

The  wood  of  the  laurus  is  cut  into  small  pieces,  and  put,  with  plenty  of  water,  into 
large  iron  boilers,  which  are  covered  with  an  earthen  capital  or  dome,  lined  within  with 
rice  straw.  As  the  water  boils,  the  camphor  rises  with  the  steam,  and  attaches  itself  as 
a  sublimate  to  the  stalks,  under  the  form  of  granulations  of  a  gray  color.  In  this  state, 
it  is  picked  off  the  straw,  and  packed  up  for  exportation  to  Europe. 

Formerly  Venice  held  the  monopoly  of  refining  camphor,  but  now  France,  England, 
Holland,  and  Germany  refine  it  for  their  own  markets.  All  the  purifying  processes  pro- 
ceed on  the  principle  that  camphor  is  volatile  at  the  temperature  of  400°  F.  The  sub- 
stance is  mixed,  as  intimately  as  possible,  with  2  per  cent,  of  quicklime,  and  the  mixture 
is  introduced  into  a  large  bottle  made  of  thin  uniform  glass,  sunk  in  a  sand  bath.  The 
fire  is  slowly  raised  till  the  whole  vessel  becomes  heated,  and  then  its  upper  part  is  gradu- 
ally laid  bare  in  proportion  as  the  sublimation  goes  on.  Much  attention  and  experience 
are  required  to  make  this  operation  succeed.  If  the  temperature  be  raised  too  slowly, 
the  neck  of  the  bottle  might  be  filled  with  camphor  before  the  heat  had  acquired  the 
proper  sublimin?  pitch ;  and,  if  too  quickly,  the  whole  contents  might  be  exploded.  If 
the  operation  be  carried  on  languidly,  and  the  heat  of  the  upper  part  of  the  bottle  be 
somewhat  under  the  melting  point  of  camphor,  that  is  to  say,  a  little  under  350**  F.,  the 
condensed  camphor  would  be  snowy,  and  not  sufficiently  compact  and  transparent  to  be 
saleable.  Occasionally,  sudden  alternations  of  temperature  cause  little  jets  to  be  thrown 
up  out  of  the  liquid  camphor  at  the  bottom  upon  the  cake  formed  above,  which  soil  it, 
and  render  its  re-sublimation  necessary. 

If,  to  the  mixture  of  100  parts  of  crude  camphor  and  2  of  quicklime,  2  parts  of  bone- 
Wack,  in  fine  powder,  be  added,  the  small  quantity  of  coloring  matter  in  the  camphor 
will  be  retained  at  the  bottom,  and  whiter  cakes  will  be  produced.  A  spiral  slip  of  pla- 
tina  foil  immersed  in  the  liquid  may  tend  to  equalize  its  ebullition. 

By  exposmg  some  volatile  oils  to  spontaneous  evaporation,  at  the  heat  of  about  70"  F., 
Proust  obtained  a  residuum  of  camphor ;  from  oil  of  lavender,  25  per  cent,  of  its  weight; 
from  oil  of  sage,  12^ ;  from  oil  of  marjoram,  10. 

Refined  camphor  is  a  white  translucid  solid,  possessing  a  peculiar  taste  and  smell. 
It  may  be  obtained,  from  the  slow  cooling  of  its  alcoholic  solution,  in  octahedral 
crystals.  It  may  be  scratched  by  the  nail,  is  very  flexible,  and  can  be  reduced  into  pow- 
der merely  by  mixing  it  with  a  few  drops  of  alcohol.  Its  specific  gravity  varies  from 
0*985  to  0'996.  Mixed  and  distilled  with  six  times  its  weight  of  clay,  it  is  decomposed, 
and  yields  a  golden  yellow  aromatic  oil,  which  has  a  flavour  analogous  to  that  of  a 
mixture  of  thyme  and  rosemary:  along  with  a  small  quantity  of  acidulous  water 
tinged  with  that  oil,  charcoal  remains  in  the  retort.  In  the  air,  camphor  takes  fire  on 
contact  of  an  ignited  body,  and  burns  all  away  with  a  bright  fuliginous  flame. 

Camphor  is  little  soluble  in  water;  one  part  being  capable  of  communicating  smell 
and  taste  to  1000  of  the  fluid.  100  parts  of  alcohol,  spec.  grav.  0806,  dissolve  120 
parts  of  camphor,  at  ordinary  temperatures.  It  is  separated,  in  a  pulverulent  state,  by 
water.    Ether  and  oils,  both  expressed  and  volatile,  also  dissolve  it 


352 


CANDLES. 


.1  , 


Ca^horlwl^T^f-^^'  ?^'^'  of  aquafortis,  camphor  is  converted  into  camphoric  acid. 
orirsftrLt^rlt^^^  •r'V'l\°'""'  of  muriatic  acid  gaS,  and  is  transfonned  into  a  coll 
oriess  transparent  liquid,  which  becomes  solid  in  the  air,  because  the  acid  attract!  hu- 

ZtfoVtmShrr'^'TJ'^'^^  '''  r^P'^"   .^°^  P^^^  ''  ^^^-'^  acetic  acifdi^Lhes  tw^ 
«n?i?^«      ^    "^^     -S^  my  analysis,  camphor  consists  of  77-38  carbon,  1V^4  hydrogen 
n  I  iV wS^^f.^"-  .  ^^^^?^'"^'s  numbers  are  certainly  erroneous.  '  ^     ^     ' 

^ye^^I^e'^I'.-a^^^^^^^^^  ^-^^  ^^^^^  —  ^°  P—  ^^^ilar 

CA^DLE.  (Chandelle,  Fr. ;  JiTerzc,  iic/i^  Geim.)  I  shall  first  briefly  describe  the 
SST;h'"'""^'''"  •"  'I  '""'^^.^^-  P^y  ^^«  ^^^^^^  dipped  or  moulder  ButThe  ^st 
tMo^ilZ^lTTf  ''  '^^r'^'^i?  ^^  '^^  ^^"°^-     M"««"  ^"^t  with  a  proportion  of  ox 

t^ow  re  er  ed  forTr  ?•  "^T''  $r"''.!J  ^'''^  '^'"^  ^^'''  ^"^  consistence.  Coarser 
laiiow  is  reserved  for  the  dipped  candles.     After  being  sorted,  it  is  cut  into  small  nieces 

D^motr^«  n  .  r'^''  '^'  Sf'Jr'  *^.""^"'^  ^^'^  ^^'•^"S  and  fleshy  matters  mixed  with  ft 
thXttomnf  th    r"°?*    ™«^.i\t««  ^^o^^n^only  melted  by  a  naked  fire  appUed  to 

Aft^r  bein' ?n!L  -^A  ''1?  ^  ^"^^  "^^y  ^^^^  ^^«  ^"«°^>  «^  i«  a  steam-cased  pan. 

constitut^l  ^hf  ^  considerable  tmie,  the  membraneous  matters  collect  at  the  surface 
eonstituting  the  crflrc/f/t«g«  used  sometimes  for  feeding  dogs,  after   the  fat  has  been 

coprertrru  1 -Y'  rf^^--.  J^^'^"^'  ^^^^^  ^^  ^'^^^^^  '^-»^^  -  sieve  iLTnother 
S^a  whHp  whin  t>,  r  f  "^"^  T'^^^'  ^^  *  ^*^^"§^  temperature  in  order  to  wash  it.  Af- 
^meTnfnV  t  1^  ^°'k  ""f '^'  ^.^'  '^^'^"^  ^°  *^^  ^«^--^^»  t^e  P«"fied  tallow  is  lifted  out, 
rea?y  for  use.        '^  "^'^  ^"'^"*''  ^'^  '"^^  ^^  ^  °^°^^^^te  size,  where  it  concretes,  and  h 

tolln^A^Zri^^^l^  circumstance,  that  the  wicks  for  the  best  candles  are  still  cotton 
cotto?  J?^-      •    .K^""  ^"'^'^''  Jjotwithstanding  the  vast  extension  and  perfection  of 

warS  cut  bv  alTlu  '^^  T^^  "^  T""!  °^  ^'  ^"""  ^"^^  ^««°^«  «^  <^^e^«>  ^"^  after- 
made  M.^  ^nS  IT^""".  '"*°  ^'""^^'  corresponding  to  those  of  the  candles  to  be 
St  .*/  ^^,!^^ank  obtained  a  patent,  in  June,  1822,  for  a  machine  for  cutting,  twist- 
geLal  u  rth^  ""''^'^  ^'^'^'  '^""/^  convenient,  does  not  seem  to  have  comnnto 
n«rot,?c  "      1    ^5    OP^'^^'*""^  """"^  performed  upon  a  series  of  threads  at  once.     The  ap- 

t^C  'L'il't-  f  ^  ^"'  '^  ^^°"i."^  "''^^  ^^^  «P^^^^«^  «'»«•  A  reel  extends  acroS 
frnm  .f  •       ^f,  *'»"^^''  P^^t,  Hpon  which  the  cotton  threads  have  been  previously  wound  • 

St.-  t;  'p^  ^v'^'  ^^  1'^^^^  ^^^°  P'-^P^r  ^^"?»^^'  'lo^^l^d'  «"d  cut  by  an  ingeniouTme: 
of  thnand/nnS^;.lf  ^^-^  ""11^  ^^;^  the  melted  tallow,  rubbing  them  between  the  palms 
tuhf  ^w    '    ""*  allowing  the  taUow  which  adheres  to  harden,  they  may  be  arranged 

n7shed'w1,?.T",  '^1-  ^''^f''  ^'l  '^'  P^^P^^*'  «^  ^'PP'^g-  The  dipping-room  ?sf^. 
mshed  with  a  boi  er  for  melting  the  tallow,  the  dipping-mould,  or  cistern!  and  a  large 

Thtnl/h'  ^"PP^^-^^"&  the  broaches.    From  the  ceiling  of  the  workshop  a  long  balance! 

theTroach'e'^  withT^'- 'i'"  ""^  ""^.  "^  ""^^^  ^  ^^^'^  ^^^"^^  ^^  ^"ached  for  holding 
«ie  broaches  with  the  wicks  arranged  at  proper  distances.     The  opposite  arm  is  loaded 

t^  n  .L''^  '  '^•'^""r"?^^^"'^  '^^  ^'«°^^^  ^'^'^  ^"d  to  enable  the  workman  to  asce^ 
nZ'?  •  P'^'Pr'  ''f '  f  ^^'  '^"^^^-  The  end  of  the  lever  which  supports  the  frame  i» 
bv  a  iT'^'"'"^^  '^ri'^'  dipping-cistern ;  and  the  whole  machine  is  so  balanced  that 

Is  may  be  re'^red^  '  *^^  '''*'^'  ^'^  ^^'  '^'''^"  '''^''  *^^  ""^^^^^  ^^^^'^'^  ^'  ^^" 

bnS.^  ^"Uowing  convenient  apparatus  for  dipping  candles  has  been  long  in  use  at  Edin 

wlih  fnJ"     •   ^^"^'^  ""^  *^^  dipping-room  a  strong  upright  post  a  a,  fg.  320,  is  erected 

Stance.  frL''nl^''''h  ^'  ^''  '^°  .^"^^-  ^''^^  '''  middle,  six  mortise!  are  cut  at  smSi 
mnvii  f  ™  one  another,  mto  each  of  which  is  inserted  a  Ion-  bar  of  wood  b  b,  which 

whole  ml'S^ih"^*""  ''''  '"'"  Pj"'  ^^'•^  P^^^'"-  ^^r«"§^  t^e  "^^'J'^'e  of  the  shaft.  The 
wnoie  piesents  the  appearance  of  a  large  horizontal  wheel  with  twelve  arms.   A  complete 

21Z  A  7""  f  '^"^  """"^  ''  ^!^^^  ^^  *^^  fig"^^-  ^ro°^  the  extremity  of  each  arm  is 
suspended  a  frame,  or  port,  as  the  workmen  call  it,  containing  6  rods,  on  each  of  which 
are  hung  18  wicks,  making  the  whole  number  of  wicks  upon  the  wheel  1296  The 
machine,  though  apparently  heavy,  turns  round  by  the  smallest  effort  of  the  workman  • 
and  each  port,  as  it  comes  lu  succession  over  the  dipping-mould,  is  gently  pressed  down' 
wards,  by  which  means  the  wicks  are  regularly  immeFsed  in  melted  taflow.     As  ^e 

^Zh!  •?'  T-  ^''  n"  f  II''  '"°-n  ^'1f^''  ""^'^  "^  «^^'h  ''  loaded  with  nearly  the  same 
weight,  It  IS  obvious  that  they  will  all  naturally  assume  a  horizontal  position.  lu 
order,  however,  to  prevent  any  oscillation  of  the  machine  in  turning  round,  the 
evers  are  kept  in  a  l.orizontal  position  by  means  of  small  chains  a  a,  one  ind  of  which 
18  fixed  to  the  top  of  the  upright  shaft,  and  the  other  terminates  in  a  small  square  piece 
of  wood,  6,  which  exactly  fills  the  notch  c  in  the  lever.  As  one  end  of  the  feve? 
must  be  depressed  at  each  dip,  the  square  piece  of  wood  is  thrown  out  of  the  not<;h 


CANDLES. 


d5S 


by  the  workmen  pressing  down  the  handle  d,  which  communicates  with  the  small  lever  <; 
inserted  into  a  groove  in  the  bar  b.     In  order  that  the  8(^uare  piece  of  wood  fixed  in  one 

extremity  of  the  chain  may  recover  its 
position  upon  the  workman's  raising 
the  port,  a  small  cord  is  attached 
to  it,  which  passes  over  a  pulley  in- 
serted in  a  groove  near  c,  and  com- 
municates with  another  pulley  and 
weight,  which  draws  it  forward  to 
the  notch.  In  this  way  the  operation 
of  dipping  may  be  conducted  by  a 
single  workman  with  perfect  ease 
and  regularity,  and  even  dispatch. 
No  time  is  lost,  and  no  unnecessary 
labour  expended,  in  removing  the 
ports  after  each  dip  ;  and,  besides, 
the  process  of  cooling  is  much  accele- 
rated by  the  candles  being  kept  in 
constant  motion  through  the  air.  The 
number  of  revolutions  which  the  wheel 
must  make,  in  order  to  complete  one 
operation,  must  obviously  depend  upon 
the  state  of  the  weather  and  the  size 
of  the  candles ;  but  it  is  said  that,  in 
moderately  cold  weather,  not  more  than  two  hours  are  necessary  for  a  single  person 
to  finish  one  wheel  of  candles  of  a  common  size.  Upon  the  supposition,  therefore, 
that  six  wheels  are  completed  in  one  day,  no  less  a  number  than  7776  candles  will  be 
manufactured  in  that  space  of  time  by  one  workman. 

I  shall  next  describe  the  process  of  moulding,  which,  if  possible,  is  even  less  com 
plicated  in  its  details  than  that  of  dipping.  The  moulds  are  made  of  some  metallic 
substance,  usually  pewter,  and  consist  of  two  parts.  The  shaft  or  great  body  of  the 
mould  is  a  hollow  cylinder,  finely  polished  in  the  inside,  and  open  at  both  extremities. 
The  top  of  the  mould  is  a  small  metallic  cup,  having  a  moulding  within-side,  and  a  hole 
to  admit  the  wick.  The  two  parts  are  soldered  together,  and  when  united,  as  will  rea- 
dily be  imagined,  have  the  shape  of  a  moulded  candle.  A  third  piece,  called  the  foot,  is 
sometimes  added  :  it  is  a  kind  of  small  funnel,  through  which  the  liquid  tallow  runs  into 
the  mould,  and,  being  screwed  to  the  opposite  extremity  of  the  shaft,  is  removeable  at 
pleasure.  This  additional  piece  may  certainly  be  useful  in  very  mild  weather,  since,  by 
removing  it,  the  candles  may  be  drawn  more  easily  from  the  moulds ;  but,  in  general,  it 
may  be  dispensed  with. 

Eight  or  twelve  of  these  moulds,  according  to  their  size,  are  fixed  in  a  frame,  which 
bears  a  great  resemblance  to  a  wooden  stool,  the  upper  surface  of  which  forms  a  kind  of 
trough.  The  top  of  the  moulds  points  downwards,  and  the  other  extremity,  which  is 
open,  is  inserted  into  the  bottom  trough  or  top  of  the  stool,  and  made  quite  level  with  its 
upper  surface.  In  order  to  introduce  the  wicks  into  the  mould,  the  workman  lays  the 
frame  upon  its  side  on  an  adjoining  table,  and  holding  in  his  left  hand  a  quantity  of  wicks, 
previously  cut  to  the  proper  length,  he  introduces  into  the  mould  a  long  wire  with  a 
hooked  point.  As  soon  as  the  hook  of  the  wire  appears  through  the  hole  in  the  top  of 
the  mould,  he  attaches  to  it  the  looped  end  of  the  wick,  and,  immediately  drawing  back 
the  wire,  carries  the  wick  along  with  it.  In  this  manner  each  mould  in  succession  is 
furnished  with  a  wick.  Another  workman  now  follows,  and  passes  a  small  wire  through 
the  loop  of  each  wick.  This  wire  is  obviously  intended  to  keep  the  wick  stretched,  and 
to  prevent  it  from  falling  back  into  the  mould  upon  the  frame  being  placed  in  the  propel 
position  for  filling.  The  frame  is  th'^n  handed  to  the  person  that  fills  the  moulds,  who 
previously  arranges  the  small  wires  in  such  a  manner  that  each  wick  may  be  exactly 
in  the  axis  of  the  mould. 

The  moulds  are  filled  by  running  tallow  into  each  of  them,  or  into  the  trough,  from  a 
cistern  furnished  with  a  cock,  and  which  is  regularh'  supplied  with  tallow  of  the  proper 
temperature  from  an  adjoining  boiler.  When  the  workman  observes  that  the  moulds  are 
nearlyhalf  filled  he  turns  the  cock.and  laying  hold  of  that  portion  of  the  wick  which  hangs 
out  of  the  moulds,  pulls  it  tight,  and  thus  prevents  any  curling  of  the  wick,  which  might 
injure  the  candles :  he  then  opens  the  cock,  and  completes  the  process  of  filling.  The  frame 
is  now  set  aside  to  cool ;  and  when  the  tallow  has  acquired  a  proper  consistence,  which  the 
workman  easily  discovers  by  a  snapping  noise  emitted  by  the  candles  upon  pressing  hi* 
thumb  against  the  bottom  of  the  moulds,  he  first  withdraws  the  small  wires  which  kepi 
the  wicks  tense,  and  then,  scraping  off  the  loose  tallow  from  the  top  of  the  frame  with 
\  small  wooden  spade,  he  introduces  a  bodkin  into  the  loop  of  the  wick,  and  thus 

Vol.  L  2Z 


354 


CANDLES. 


CANDLES. 


855 


If  m 


!!!>' 


i        ! 


draws  each  candle  in  succession  from  its  mould.  The  candles  are  now  laid  upon  a 
table  for  the  inspection  of  the  exciseman,  and  afterwards  removed  to  the  storehouse. 
Previous  to  storing  them  up,  some  candle-makers  bleach  their  candles,  by  exposing 
them  to  the  air  and  dfcws  for  several  days.  This  additional  labour  can  be  necessary 
only  when  the  dealer  is  obliged  to  have  early  sales ;  for  if  the  candles  are  kept  for 
some  months,  as  they  ought  to  be,  before  they  are  brought  to  market,  they  become 
sufficiently  whitened  by  age. 

Wax  candles.— Nejit  to  tallow,  the  substance  most  employed  in  the  manufacture 
of  candles  is  wax.  Wax  candles  are  made  either  by  the  hand  or  with  a  ladle.  In  the 
former  case,  the  wax,  being  kept  soft  in  hot  water,  is  applied  bit  by  bit  to  the  wick, 
which  is  hung  from  a  hook  in  the  wall ;  in  the  latter,  the  wicks  are  hunjr  round  an  iron 
circle,  placed  immediately  over  a  large  copper-tinned  basin  full  of  melted  wax,  which  is 
poured  upon  their  tops,  one  after  another,  by  means  of  a  large  ladle.  When  the  candles 
have  by  either  process  acquired  the  proper  size,  they  are  laken  from  the  hooks,  and 
rolled  upon  a  table,  usually  of  wabiut-tree,  with  a  long  square  instrument  of  box,  smooth 
at  the  bottom. 

A  few  years  ajjo  I  made  a  set  of  experiments  upon  the  relative  intensities  of  light,  and 
duration  of  different  candles,  the  results  of  which  are  contained  in  the  followine 
table. 


Namber  in  a  pound. 

Duration  of  a 
candle. 

Weight  in 
grains. 

Consumption 

per  hoar  in 

grains. 

Proportion 
of  ight. 

Eronomy 
of  light. 

Candlcfc 
equal  one 
Argand. 

10  mould  -    -    - 

10  dipped-    -    - 

8  mould  -    -    - 

6  ditto    -    -    - 

4  ditto    -    -    - 

Argand  oil  flame 

k.       m. 
6      9 
4    36 

6  31 

7  2| 
9     3-6 

682 

672 

856 

1160 

1707 

132 
150 
132 
163 
186 
512 

12i 
13 
101 
14f 
20i 
69-4 

68 
65^ 
69| 
66 
80 
100 

5-7 

5-25 

6-6 

5-0 

3-5 

A  Scotch  mutchkin,  or  |  of  a  gallon  of  good  seal  oil,  weighs  6010  gr.,  or  13  JL  oz., 
avoirdupois,  and  lasts  in  a  bright  Argand  lamp  11  hours  44  minutes.  The  weight  of 
oil  it  consumes  per  ho'ir  is  equal  to  4  times  the  weight  of  tallow  in  candles  8  to  the 
pound,  and  i  the  weigh  of  tallow  in  candles  6  to  the  pound.  But,  its  light  being  equal 
to  that  of  6  of  the  latter  candles,  it  appears  from  the  above  table  that  2  pounds  weight  of 
oil,  value  9d.  in  an  Argand,  are  equivalent  in  illuminating  power  to  3  pounds  of  tallow 
candles,  which  cost  about  two  shilhngs.  The  larger  the  flame  in  the  above  candles  the 
greater  the  economy  of  light. 

In  June,  1825,  M.  Gay  Lussac  obtained  a  patent  in  England  for  making  candles  from 
margaric  and  stearic  acidsy  improperly  called  */eanw«,  by  converting  tallow  into  the  above 
fat  acids  by  the  following  process : — Tallow  consists,  by  Chevreul's  researches,  of  stearine, 
a  solid  fat,  and  elaine,  a  liquid  fat;  the  former  being  in  much  the  larger  proportion. 
When  tallow  is  treated  with  an  alkaline  body,  such  as  potash,  scda,  or  lime,  it  is  saponified  j 
that  is,  its  stearine  and  elaine  become  respectively  stearic  and  elaic  acids,  and,  as  such, 
form  compounds  with  these  bases.     When  by  the  action  of  an  acid,  snch  as  the  sulphuric 
or  muriatic,  these  combinations  are  decomposed,  the  fats  reappear  in  the  altered  form  of 
•tearic  and  elaic  acids ;   the  former  body  being  harder  than  tallow,  and  of  a  texture 
somewhat  like  spermaceti,  the  latter  body  being  fluid,  like  oil.   "  The  decomposition  of  the 
soap  should  be  made,"  says  the  patentee,  "in  a  large  quantity  of  water,  kept  well  stirred 
during  the  operation,  and  warmed  by  steam  introduced  in  any  convenient  way.    When 
the  mixture  has  been  allowed  to  stand,  the  acid  of  the  tallow  or  fat  will  rise  to  the 
surface,  and  the  water  being  drawn  off  will  carry  the  alkaline  or  saline  matters  with  it, 
hut  if  the  acids  of  the  tallow  should  retain  any  portion  of  the  salts,  fresh  water  may  be 
thrown  upon  it,  and  the  whole  well  agitated,  until  the  acids  have  become  perfectly  free 
from  the  alkaline  matters ;  and  when  allowed  to  cool,  the  acids  will  be  formed  into  a 
solid  mass.    This  mass  is  now  to  be  submitted  to  considerable  pressure  in  such  an  api)a- 
ratus  as  is  employed  in  expressing  oil  from  seeds ;  when  the  liquid  acid  will  run  off  in  the 
form  of  a  substance  resembling  oil,  leaving  a  solid  matter,  similar,  in  every  respect,  to 
spermaceti,  which  is  fit  for  making  candles." 

The  wick  to  be  used  in  the  manufacture  of  these  improved  candles,  and  which  forms 
one  of  the  features  of  this  invention,  is  to  be  made  of  cotton  yarn,  twisted  rather  hard, 
and  laid  in  the  same  manner  as  wire  is  sometimes  coiled  round  bass  strings  of 
musical  instruments.  For  this  purpose  straight  rods  or  wires  are  to  be  procured,  of 
suitable  lengths  and  diameters,  according  to  the  intended  size  of  the  candles  about  to  be 
made :  and  these  wires,  having  been  covered  with  cotton  coiled  round  them  as  described, 
lire  to  be  inserted  in  the  candle  moulds  as  the  common  wicks  are ;  and  when  the  candle 


is  made,  and  perfectly  hard,  the  wire  is  to  be  withdrawn,  leaving  a  hollow  (jylindrical 
aperture  entirely  through  the  middle  of  the  candle.     See  Stkarink. 
CANDLES.    Messrs.  Hempel  and  Blundell  have  given  a  very  minute  account  of 

the  process  for  making  pahn-oil,  stearic  and  margaric  acids,  in  the  specification  of  their 

patent  for  this  mode  of  manufacturing  candles  : — 

1.  Their  first  process  is  called  crystallization,  which  consists  in  pouring  the  melted 
palm-oil  into  iron  pans,  and  allowing  it  to  cool  slowly,  whereby,  at  about  75°  F.,  the 
elaine  separates  from  the  crystalline  stearine  and  margarine. 

2.  The  concreted  oil  is  subjected  to  the  action  of  an  hydraulic  press,  in  order  to  sep- 
arate the  elaine  from  the  solid  fats. 

3.  This  process  is  called  oxidation.  To  104  lbs.  of  the  stearine  and  margarine, 
melted  in  an  iron  pan,  about  12  lbs.  of  slaked  and  sifted  quicklime  are  added,  with 
diligent  stirring,  during  which  the  temperature  is  to  be  slowly  raised  to  240"  F.,  and 
6o  maintained  for  about  three  hours,  till  a  perfect  chemical  combination  takes  place. 
This  is  shown  by  the  mass  becoming  thin,  transparent,  and  assuming  a  glassy  appear- 
ance when  it  cools.  The  fire  being  now  withdrawn,  cold  water  is  added  very  gradually 
at  first,  with  brisk  stirring  till  the  whole  mass  falls  into  a  state  of  powdery  granulation, 
when  it  is  passed  through  a  wire  sieve  to  break  down  any  lumps  that  may  remain. 

4.  Separation  of  the  stearic  and  margaric  adds  from  the  lime.  For  this  p'^rpose,  as 
much  muriate  of  lime  (chlorcalcium)  is  taken  as  will,  with  its  equivalent  qi:>t,itity  of 
sulphuric  acid  (8  lbs.  of  dry  chlorcalcium  require  7  lbs.  of  the  strongest  sulphuric 
acid),  produce  as  much  muriatic  acid  as  will  dissolve  the  lime  combined  with  the  fat 
acids ;  and  therefore  that  quantity  of  muriate  of  lime  dissolved  in  water  must  be 
treated  with  as  much  sulphuric  acid  as  will  saturate  its  lime  and  throw  it  down  in  the 
state  of  sulphate  of  lime.  Add  the  supernatant  solution  of  muriatic  acid  in  such  pro- 
portion to  the  stearate  and  margarate  of  lime  as  will  rather  more  than  saturate  the 
lime.  Three  pounds  of  muriatic  acid  diluted  with  9  lbs.  of  water  are  stated  as  enough 
for  1  lb.  of  lime.  This  mixture  is  to  be  let  alone  for  3  or  4  days,  in  order  to  insure  the 
complete  separation  of  the  lime  from  the  fat  acids ;  and  then  the  mixture  is  heated  so 
as  to  melt  and  cause  them  to  separate  in  a  stratum  on  the  top  of  the  liquid.  The  re- 
sulting muriate  of  lime  is  drawn  off  into  another  tub,  and  decomposed  by  its  dose  of 
sulphuric  acid,  so  as  to  liberate  its  muriatic  acid  for  a  fresh  operation. 

5.  The  fat  acids,  being  well  washed  by  agitation  with  hot  water,  are  then  set  to  cool 
and  crystallize,  in  which  state  they  are  subjected  to  the  action  of  the  hydraulic  press, 
at  a  temperature  of  75"  F.,  whereat  the  margaric  acid  runs  off  from  the  solid  stearic 
acid. 

6.  Bleaching.  The  stearic  acid  is  taken  from  the  press,  and  exposed  upon  water  in 
large  shallow  vessels  placed  in  the  open  air,  where  it  is  kept  at  the  melting  tempera- 
ture from  8  to  12  hours,  stirring  meanwhile,  in  order  to  promote  the  blanching  action 
of  the  atmosphere.  The  margaric  acid  is  bleached  in  a  similar  manner  in  separate 
vessels. 

7.  Refining  process.  The  fat  is  warmed  again,  and  poured  in  a  liquid  state  into  an 
agitating  tub ;  where,  for  every  1,000  lbs.  of  the  stearic  acid,  about  2|  lbs.  of  common 
black  oxide  of  manganese,  and  40  lbs.  of  concentrated  sulphuric  acid,  diluted  with 
200  lbs.  of  pure  water,  are  to  be  used.  This  solution  ("  mixture"),  while  warm  from 
the  heat  evolved  in  diluting  the  acid,  is  placed  in  a  suitable  vessel  above  the  agitating 
tub.  The  stearic  acid  being  at  the  melting  point,  in  the  vessel  below,  agitation  is  to 
be  given  with  a  revolving  shaft,  while  the  mixed  manganese  and  acid  are  run  slowly 
down  into  it,  till  the  whole  be  well  mixed,  which  generally  requires  about  two  hours. 
Th':  mass  b  allowed  to  lie  in  this  state  for  48  hours  ;  after  which  it  may  be  boiled  by 
■lean  for  2  or  3  hours,  when  it  will  be  sufficiently  refined.  The  sulphuric  acid,  which 
is  at  the  bottom,  is  now  run  off,  and  the  stearic  acid  which  remains  is  well  washed  with 
pure  water.  It  is  then  put  into  large  conical  vessels  of  stoneware,  enclosed  in  a  box 
or  jacket,  kept  warm  by  steam-heat,  and  lined  with  conical  bags  of  suitable  strong 
filtering  paper,  through  which,  being  warm,  it  finds  its  way ;  and  when  the  stearic  acid 
has  bei^n  tjjus  filtered,  it  is  run  into  blocks,  when  it  will  be  found  to  be  a  beautiful 
itearic  acid  or  palm-wax,  and  is  ready  to  be  made  into  candles  in  the  usual  way. 

On  the  above  process  with  manganese  and  diluted  sulphuric  acid,  it  may  be  observed, 
that  no  solution  or  chemical  action  takes  place  between  them,  and  their  joint  use  seems 
therefore  most  problematical.    The  patentees  proceed  to  describe  other  processes  of 
refining,  in  which  sulphate  of  manganese,  with  common  salt,  phosphoric  acid  (highly 
concentrated),  and  oxalic  acid,  are  used,  and  in  my  opinion  either  ignorantly  or  for  the 
purpose  of  mystification ;  for,  as  prescribed,  they  can  serve  no  possible  purpose  of 
purifying  the  stearnine. 

The  chief  solid  constituent  of  palm-oil  is  margaric  acid.  This  they  direct  to  be 
melted  with  tallow,  in  the  proportion  of  from  10  to  20  lbs.  of  the  former  to  100  lbs.  of 
the  latter.     See  NevotorCs  Journal,  C.  8.,  xL  207. 

222* 


856 


CANDLES. 


if! 


I  was  told  by  M.  Runge,  at  Berlin,  that  lie  was  the  inventor  of  the  process  for 
makini^  white  margaric  acid  from  palm-oil,  and  that  Hempel  h&d  got  it  somehow 
irom  him,  but  most  imperfectly,  as  it  would  appear.  Hempel  died  here  in  the  midst 
oi  tne  above  patent  operations;  but  the  specification  is,  no  doubt,  a  specimen  of  his 
""  m"  WM ''^  of  Runge's  margaric  acid     He  gave  me  a  splendid  pearly-looking  sample. 

Mr.  Wilson  of  Belmont,  Vauxhall,  obtained  in  August,  1844,  a  patent  for  Tmprove- 
menta  m  treating  fats  for  inaking  candles.     If  distilled  fats  are  used  in  making  compo- 
site candles,  they  are  bleached  and  hardened  in  that  operation.     When  palm5>il  is  the 
material,  it  is  first  sapomfied ;  then  distilled,  granulated  by  fusion  and  slow  cooling  and 
cold-pressed ;  by  which  means  stearic  acid  and  a  light  coloured  oil  are  obtained  •  which 
may  be  mixed  with  the  steanne  of  cocoa-nut  oU,  or  other  stearine.     A  cheaper'  article 
Tl  A^A^  ^J  ""J?"^  the  entire  product  of  the  above  distillation  with  half  its  weight 
of  distilled  and  cold-pressed  stearic  acid  of  tallow.    Tallow  is  deprived  of  its  oleine  bv 
pressure  accompanied  by  artificial  cold  if  necessary ;  this  being  added  to  the  other  harS 
matter  the  mixture  is  converted  mto  fatty  acids,  and  distilled,  and  the  entire  product  of 
d^tillation  IS  employed  for  makmg  candles ;  or  it  may  be  pressed  to  make  them  harder. 
Aa  distilled  stearic  acid  is  more  crystalline  than  undistillei  2  or  4  per  cent,  of  wax  may 
be  added  to  assist  the  combmation  of  the  fatty  acid  with  the  Bte&nne.—Newto7i'8  Jour- 
nal,  XXVI.  165. 

Candles  consisting  of  alternate  layers  of  tallow  and  stearine  have  been  made  by  dippinff 
their  wicks  alternately  m  these  two  fatty  bodies  in  a  fluid  state.  Mr.  W.  iSykes  has 
gone  to  the  expense  of  a  patent  on  the  contrivance.  The  wicks  are  impregnated  with 
a  solution  of  bismuth  or  borax.  ^ 

New  patent  candle  manufacture.— YegetaUe  tallow  melts  at  a  degree  of  heat  somewhat 
above  that  of  animal  tallow,  but  considerably  below  that  of  vegetable  wax.    Mr.  Wilson 
of  Belmont,  Vauxhall,  treats  his  tallow  by  putting  6  tons  of  it  into  an  iron  still  capable 
of  ho  ding  9  tons,  heats  it  gradually  to  350°  Fahr.,  and  then  adds  gradually  1440  lbs 
of  sulphuric  acid  of  1-8  sp.  gr.     At  the  expiration  of  about  2  hours,  the  tallow  is 
pumped  into  a  vessel,  containing  water  slightly  acidulated  with  sulphuric  .\-id  •  and  is 
therein  agitated  by  free  steam  passing  through  it  for  2  hours.     The  materials  are  then 
left  to  repose  for  6  hours ;  both  this  vessel  and  the  former  should  be  provided  with  a 
cover  and  a  means  of  conveying  the  gases  which  may  be  evolved  into  a  chimney. 
Ihe  vegetable  tallow  is  next  distilled  in  such  a  manner  that  the  atmosphere  is  excluded 
This  is  best  effected  by  the  use  of  steam  highlj  heated,  which  he  introduces  into  the  stilL 
m  numerous  jets  below  the  tallow.    The  distilled  products  are  received  into  condensers 
and  they  may  be  used  alone,  or  they  may  be  mixed  with  other  matters  for  making  the 
best  class  of  candles.     The  patentee  improves  paraffine  by  a  like  process.     He  makes 
candles  with  2  or  3  wicks,  by  mixing  palm-oil  pressed  with  tallow,  or  the  above  distilled 
fat,  for  burning  in  cundle  lamps. — Newton's  Journal,  xxxv.  108. 

The  following  is  one  of  his  later  processes.    Candles  and  night-lights  are  manufactured 
by  3Ir.  Wilson  of  Vauxhall,  by  combining  palm-oil  which  has  been  bleached  by  the 
atmosphere  with  distilled  fatty  acids,  with  or  without  other  fats.     By  combining  one 
part  of  crude  cocoa-nut  oil,  one  part  of  cold  pressed  atmospherically  bleached  palm-oil 
and  one  part  of  impressed  palm-oil,  acidified  by  sulphuric  acid  and  distilled,  an  excellent 
product  18  obtained ;  and  other  distilled  fatty  acids  may  be  used,  pressed  or  unpressei 
fhis  distillation  is  effected  by  transmitting  through  the  fat  contained  in  an  iron  stilL 
steam  at  about  600°  or  700°  Fahr.,  heated  by  passing  through  iron  pipes  laid  in  a  fire. 
The  steam  is  transmitted  till  the  oily  matter  is  heated  to  about  350°  ;  the  vapours 
produced  being  carried  into  a  high  shaft  by  a  pipe  from  the  cover  of  the  iron  vessel. 
The  hot  oily  matter  is  then  run  into  another  vessel  made  of  brick  lined  with  lead,  and  sunk 
in  the  ground,  for  the  purpose  of  supporting  the  brick-work  under  or  against  the  internal 
pressure  of  the  fluid.  It  has  a  wooden  cover  lined  with  lead,  directly  beneath  which,  and 
extending  across  the  vessel,  is  a  leaden  pipe,  1  inch  in  diameter,  having  a  small  hole  in 
each  side,  at  every  six  inches  of  its  length ;  and  through  this  pipe  is  introduced  a  mixture 
of  1000  lbs.  of  sulphuric  acid,  sp.  gr.  1  -8.,  and  the  same  weight  of  water.     The  introduc- 
tion of  the  mixture  which  falls  in  divided  jets  into  the  heated  fat,  produces  violent  ebul- 
lition ;  and  by  this  means  the  acid  and  fat  are  perfectly  incorporated  before  the  action  of 
the  acid  becomes  apparent  by  any  considerable  discoloration  of  the  fat.     As  the  ebulli- 
tion  ceasesj  the  fat  gradually  blackens ;  and  the  matter  is  allowed  to  remain  for  6  hours 
after  the  violent  ebullition  has  ceased.     The  offensive  fumes  produced  are  carried  off  by 
a  large  pipe,  which  rises  from  the  top  of  the  vessel,  then  descends,  and  afterwards  rises 
again  into  a  high  chimney.    At  the  downward  part  of  this  pipe  a  small  jet  of  water  is 
kept  playing,  to  condense  such  parts  of  the  vapours  as  are  condensable.    At  the  end  of 
the  6  hours  above  mentioned,  the  operation  is  complete,  and  the  product  is  then  pumped 
into  another  close  vessel  and  washed  by  being  boiled  up  (by  means  of  free  steam)  with 
half  its  bulk  of  water.     The  water  is  drained  off,  and  the  washing  repeated,  except  thai 
in  the  second  washing  the  water  is  acidulated  with  100  lbs.  of  sulphuric  acid.    The 


CAOUTCHOUC. 


357 


ultimate  product  is  allowed  to  settle  for  24  hours ;  after  which  it  b  distilled  in  an  atmo- 
sphere of  steam,  once  or  oftener,  until  well  purified ;  and  the  product  of  distillation  is 
again  washed,  and  after  being  pressed  in  the  solid  state,  is  applied  to  ihe  manufacture 
of  candles. — Newton's  London  Journal,  xxvi.  and  xxxv. 

CANE-MILL.     See  Mill  and  Sugar. 

CANNON.     For  the  composition  of  these  implements  of  destruction,  see  Bronze. 

CANVASS.  {Canevas,  Fr. ;  Segeltuch,  Germ.)  It  has  been  found  that  sails  of  ships 
Hade  with  the  selvages  and  seams  of  the  canvass  running  down  parallel  to  their  edges, 
ye  very  apt  to  bag,  and  become  torn  in  the  middle,  from  the  strain  to  which  they  are  sub- 
jected by  the  pressure  of  the  wind.  To  obviate  this  inconvenience,  a  mode  of  making 
sails,  with  the  seams  and  selvages  running  diagonally,  was  proposed  by  Admiral  Brooking, 
ind  a  patent  granted  to  him  for  the  same  on  the  4lh  of  September,  1828.  The  invention 
of  Messrs.  Ramsay  and  Orr,  which  we  are  about  to  describe,  has  a  similar  object,  viz., 
that  of  giving  additional  strength  to  sails  by  a  peculiar  manner  of  weaving  the  canvas* 
of  which  they  are  made. 

The  improvement  proposed  under  their  patent  of  March,  1830,  consists  in  weaving  the 
canvass  with  diagonal  threads;  that  is,  placing  the  weft  yam,  or  shoot,  in  weaving,  at  an 
oblique  angle  to  the  warp  yarns,  instead  of  making  the  decussation  of  the  warp,  or  weft 
threads,  or  yarns,  at  right  angles  to  each  other,  as  in  the  ordinary  mode  of  weaving. 

To  accomplish  this  object,  the  loom  must  be  peculiarly  constructed ;  that  is,  its  warp 
and  work  beams  must  stand  at  an  oblique  angle  with  the  sides  of  the  loom,  and  the  batten 
and  slay  must  be  hung  in  a  peculiar  manner,  in  order  to  beat  up  the  weft,  or  shoot,  in 
lines  ranging  diagonally  with  the  warp.  No  drawing  is  shown  of  the  method  by  which 
this  arrangement  of  the  loom  is  to  be  made,  but  it  is  presumed  that  any  weaver  would 
know  how  to  accomplish  it :  the  invention  consisting  solely  in  producing  sail-cloth  with 
the  threads  or  yarns  of  the  weft  ranging  diagonally  at  any  desired  angle  with  the  direc 
tion  of  the  warp  thread. 

CAOUTCHOUC,  GUM-ELASTIC,  or  INDIAN-RUBBER  {Federharz,  Germ.),  oc- 
curs as  a  milky  juice  in  several  plants,  such  as  the  siphonia  cahuca,  called  also  hevea  guir 
anensiSf  cautschuc,  jatropha  elastica,  caatilleja  elaslica,  cecropia  pdlatay  ficus  religiosa 
and  undicay  urceolaria  elastica,  &c.  It  is,  however,  extracted  chiefly  from  the  first  plant, 
which  grows  in  South  America  and  Java.  The  tree  has  incisions  made  into  it  through 
the  bark  in  many  places,  and  it  discharges  the  milky  juice,  which  is  spread  upon  clay 
moulds,  and  dried  in  the  sun,  or  with  the  smoke  of  a  fire,  which  blackens  it. 

The  juice  itself  has  been  of  late  years  imported.  It  is  of  a  pale  yellow  color,  and  has 
the  consistence  of  cream.  It  becomes  covered,  in  the  bottles  containing  it,  with  a  pellicle 
of  concrete  caoutchouc.  Its  spec.  grav.  is  1-012.  When  it  is  dried,  it  loses  55  per  cent, 
of  its  weight :  the  residuary  45  is  elastic  gum.  When  the  juice  is  heated,  it  immediately 
coagulates,  in  virtue  of  its  albumen,  and  the  elastic  gum  rises  to  the  surface.  It  mixei 
with  water  in  any  proportion ;  and,  when  thus  diluted,  it  coagulates  with  heat  and  alco- 
hol as  before. 

The  specific  gravity  of  caoutchouc  is  0-925,  and  it  is  not  permanently  increased  by 
any  degree  of  pressure.  By  cold  or  long  quiescence,  it  becomes  hard  and  stiff.  When 
the  milky  juice  has  become  once  coherent,  no  means  hitherto  known  can  restore  it  to 
the  emulsive  state.  By  long  boiliug  in  water  it  softens,  swells,  and  becomes  more 
readily  soluble  in  its  peculiar  menst/ua  ;  but  when  exposed  to  the  air,  it  speedily  resumes 
its  pristine  consistence  and  volune.  It  is  quite  insoluble  in  alcohol ;  but  in  ether,  de- 
prived of  alcohol  by  washing  wiih  water,  it  readily  dissolves,  and  affords  a  colorless 
solution.  When  the  ether  is  evaporated,  the  caoutchouc  becomes  again  solid,  but  is 
somewhat  clammy  for  a  while.  When  treated  with  hot  naphtha,  distilled  from  native 
petroleum,  or  from  coal  tar,  it  swells  to  30  times  its  former  bulk  ;  and  if  then  triturated 
with  a  pestle,  and  pressed  through  a  sieve,  it  affords  a  homogeneous  varnish,  which  being 
applied  by  a  flat  edge  of  metal  or  wood  to  cloth,  prepares  it  for  forming  the  patent 
water-proof  cloth  of  Mackintosh.  Two  surfaces  of  cloth,  to  which  several  coals  of  the 
above  varnish  have  been  applied,  are,  when  partially  dried,  brought  evenly  in  contact,  and 
then  passed  between  rollers.,  in  order  to  condense  and  smooth  them  together.  This  double 
cloth  is  afterwards  suspended  in  a  stove-room  to  dry,  and  to  discharge  the  disagreeable 
odour  of  the  naphtha. 

Caoutchouc  dissolves  in  the  fixed  oils,  such  as  linseed  oil,  but  the  varnish  has  not  the 
property  of  becoming  concrete  upon  exposure  to  air. 

It  has  been  lately  asserted  that  caoutchouc  is  soluble  in  the  oils  of  lavender  and  sas- 
safras. 

It  melts  at  248°  R,  and  stands  afterwards  a  much  higher  heat  without  undergoing 
any  further  change.  When  the  melted  caoutchouc  is  exposed  to  the  air,  it  becomes 
hard  on  the  surface  in  the  course  of  a  year.  When  kindled  it  burns  with  a  bright 
flame  and  a  great  deal  of  smoke. 

Neither  chlorine,  sulphurous  acid  gas,  muriatic  acid  gas,  ammonia,  nor  fluosilicic  acid 


358 


CAOUTCHOUC. 


CAOUTCHOUC. 


359 


it 


!  \ 


gas  affects  it,  whence  it  forms  very  valuable  flexible  tubes  for  pneumatic  chemistry.  Cold 
sulphuric  acid  does  not  readily  decompose  it,  nor  does  nitric  acid,  unless  it  be  somewhat 
strong.     The  strongest  caustic  potash  ley  does  not  dissolve  it  even  at  a  boiling  heat. 

Caoutchouc,  according  to  my  experiments,  which  have  been  confirmed  by  those  of  Mr. 
Faraday,  contains  no  oxygen,  as  almost  all  other  solid  vegetable  products  do,  but  is  a 
mere  compound  of  carbon  and  hydrogen,  in  the  proportion,  by  my  results,  of  90  carbon  to 
10  hydrogen,  being  three  atoms  of  the  former  to  two  of  the  latter.  Mr.  Faraday  ob- 
tained only  87-2  carbon,  from  which  I  would  infer  that  some  of  the  carbon,  which  in  this 
substance  is  difficult  to  acidify  by  peroxyde  of  copper,  had  escaped  its  action.  It  is  ob- 
vious that  too  little  carbonic  acid  gas  may  be  obtained,  but  certainly  not  more  than  cor- 
responds 10  the  carbon  in  the  body.  No  carbon  can  be  created  in  the  process  of  ultimate 
analysis  by  pure  peroxyde  of  copper  such  as  I  employed ;  and  I  repeated  the  ignition 
after  attrition  of  the  mixture  used  in  the  experiment.  Melted  caoutchouc  forms  a 
very  excellent  chemical  lute,  as  it  adheres  very  readily  to  glass  vessels,  and  withstands 
the  corrosive  action  of  acid  vapors.  This  substance  is  much  used  for  effacing  the  traces 
of  plumbago  pencils,  whence  it  derived  the  name  of  Indian-rubber.  It  has  been  lately 
employed  very  extensively  for  making  elastic  bands  or  braces.  The  caoutchouc  bottles 
are  skilfully  cut  into  long  spiral  slips,  which  are  stretched,  and  kept  extended  till  nearly 
deprived  of  their  elasticity,  and  till  they  form  a  thread  of  moderate  fineness.  This  thread 
is  put  into  a  braid  machine,  and  covered  with  a  sheath  of  cotton,  silk,  linen,  or  worsted. 
The  clothed  caoutchouc  is  then  laid  as  warp  in  a  loom,  and  woven  into  an  elegant  riband. 
When  woven,  it  is  exposed  upon  a  table  to  the  action  of  a  hot  smoothing  iron,  which  re- 
storing to  the  caoutchouc  all  its  primitive  elasticity,  the  riband  retracts  considerably  in 
length,  and  the  braiding  corrugates  equally  upon  the  caoutchouc  cores.  Such  bands  pos- 
sess a  remarkable  elasticity,  combined  with  any  desired  degree  of  softness.  Sometimes 
cloth  is  made  of  these  braided  strands  of  caoutchouc  used  both  as  warp  and  as  weft,  which 
is  therefore  elastic  in  all  directions.  When  a  light  fabric  is  required,  the  strands  of  caout- 
chouc, either  naked  or  braided,  are  alternated  with  common  warp  yarns.  For  this  mixed 
fabric  a  patent  has  been  obtained.  The  original  manufacturer  of  these  elastic  webs  is  a 
major  in  the  Austrian  service,  who  has  erected  a  great  factory  for  them  at  St.  Denys, 
near  Paris.    See  Elastic  Bands. 

Mr.  William  Henry  Barnard,  in  the  course  of  some  experiments  upon  the  impregnation 
of  ropes  with  caoutchouc,  at  the  factory  of  Messrs.  Enderby,  at  Greenwich,  discovered  that 

when  this  substance  was  exposed  to 
a  heat  of  about  600°  F.  it  resolved 
itself  into  a  vapor,  which,  by 
proper  refrigeratory  methods,  was 
condensable  into  a  liquid  possessing 
very  remarkable  properties,  to 
which  the  name  caoutchoucine  has 
been  given.  For  this  invention 
"of  a  solvent  not  hitherto  used  in 
the  arts"  Mr.  Barnard  obtained  a 
patent,  in  August,  1833.  His 
process  for  preparing  it  is  described 
in  his  specification  as  follows: — I 
take  a  mass  of  the  said  caoutchouc, 
or  Indian  rubber,  as  imported,  and 
having  cut  it  into  small  lumps, 
containing  about  two  cubic  inches 
each  (which  I  prefer),  I  throw  these 
lumps  into  a  cast-iron  still  (which 
I  find  adapted  for  the  purpose,  and 
a  diagram  of  which  is  annexed  to, 
and  forms  part  of,  this  my  specifi- 
cation), with  a  woim  attached;  fig.  321,  a  is  the  still,  b  the  cover  ground  to  a  metallie 
fit,  to  admit  of  a  thermometer  to  take  the  temperature ;  o  the  fire-place,  d  the  ash-pit, 
s  the  worm-tub  and  worm,  f  the  brick-work  of  the  still,  g  a  roller  and  carriage,  in  con- 
junction with  a  crane,  or  other  means,  to  raise  the  cover  to  take  out  the  residue,  and  to 
charge  the  same  ;  h  the  chain. 

"  I  then  apply  heat  to  the  still  in  the  usual  manner,  which  heat  is  increased  until  the 
thermometer  ranges  at  600  degrees  of  Fahrenheit,  or  thereabouts.  And,  as  the  ther 
mometer  ranges  progressively  Uf)ward8  to  600  degrees  of  Fahrenheit,  a  dark-coloured 
oil  or  liquid  is  distilled  over,  which  I  claim  as  my  said  invention,  such  liquid  being  a 
solvent  of  caoutchouc,  and  other  resinous  and  oleaginous  substances.  When  the  ther 
mometer  reaches  600  degrees,  or  thereabouts,  nothing  is  left  in  the  still  but  dirt  and 
charcoal. 


I  have  found  the  operation  of  distillation  to  be  facilitated  by  the  addition  of  a  portion 
•f  this  oil,  either  previous  or  subsequent  to  rectification,  as  hereinafter  mentioned,  in  the 
proportion  of  one  third  of  oil  to  two  thirds  of  caoutchouc. 

I  afterwards  subject  the  dark-colored  liquid  thus  distilled  to  the  ordinary  process  of 
rectification,  and  thereby  obtain  fluids  varying  in  specific  gravity,  of  which  the  lightest 
hitherto  has  not  been  under  670,  taking  distilled  water  at  1000,  which  fluids  I  also  claim 
as  my  said  invention. 

At  each  rectification  the  color  of  the  liquid  becomes  more  bright  and  transparent,  until, 
at  the  specific  gravity  of  680,  or  thereabouts,  it  is  colorless  and  highly  volatile. 

In  the  process  of  rectification  (for  the  purpose  of  obtaining  a  larger  product  of  the  oil 
colorless)  I  put  about  one  third  of  water  into  the  still.  In  each  and  every  state  the 
liquid  is  a  solvent  of  caoutchouc,  and  several  resinous  and  oleaginous  substances,  md 
also  of  other  substances  (such  as  copal),  in  combination  with  very  strong  alcohol. 

Having  experienced  much  diflUculty  in  removing  the  dirt  which  adheres  to  the  bottom 
of  the  still,  I  throw  into  the  still  lead  and  tin  in  a  state  of  alloy  (commonly  called  solder), 
to  the  depth  of  about  half  an  inch,  and,  as  this  becomes  fused,  the  dirt  which  lies  on  the 
surface  of  it  is  more  easily  removed. 

Objections  have  been  made  to  the  smell  of  this  liquid :  I  have  found  such  smell  re- 
moved by  mixing  and  shaking  up  the  liquid  with  nitro-muriatic  acid,  or  chlorine,  in  the 
proportion  of  a  quarter  of  a  pint  of  the  acid  (of  the  usual  commercial  strength)  to  a 
gallon  of  the  liquid. 

The  discovery  of  the  chemical  solvent,  which  forms  the  subject  of  the  patent  above 
described,  has  excited  considerable  interest  in  the  philosophic  world,  not  only  from  its 
probable  usefulness  as  a  new  article  of  commerce,  but  also  from  two  very  extraordinary 
characteristics  which  it  is  found  to  possess,  viz.,  that,  in  a  liquid  state,  it  has  less  specific 
gravity  than  any  other  liquid  known  to  chemists,  being  considerably  lighter  than  sul- 
phuric ether,  and,  in  a  state  of  vapor,  is  heavier  than  the  most  ponderous  of  the  gases. 
Its  elementBTy  constituents  are, 

Carbon 6*812        -        -        -8  proportions. 

Hydrogen  ...  -  1-000  -  -  -  7  ditto. 
This  new  material  (when  mixed  with  alcohol)  is  a  solvent  of  all  the  resins,  and  particu- 
larly of  copal,  which  it  dissolves,  without  artificial  heat,  at  the  ordinary  temperature  of 
the  atmosphere ;  a  property  possessed  by  no  other  solvent  known  ;  and  hence  it  is  pecu- 
liarly useful  for  making  varnishes  in  general.  It  also  mixes  readily  with  oils,  and  will 
be  found  to  be  a  valuable  and  cheap  menstruum  for  liquefying  oil-paints ;  and,  without  in 
the  slightest  degree  affecting  the  most  delicate  colors,  will,  from  its  ready  evaporation, 
cause  the  paint  to  dry  almost  instantly. 

Cocoa-nut  oil,  at  the  common  temperature  of  the  atmosphere,  always  assumes  a  con- 
crete form ;  but  a  portion  of  this  caoutchoucine  mixed  with  it  will  cause  the  oil  to  become 
fluid,  and  to  retain  sufficient  fluidity  to  burn  in  a  common  lamp  with  extraordinary 
brilliancy. 

Caoutchoucine  is  extremely  volatile ;  and  yet  its  vapor  is  so  exceedingly  heavy,  tltat 
it  may  be  poured,  without  the  liquor,  from  one  vessel  into  another  like  water. 

Hitherto  the  greater  part  of  the  caoutchouc  has  been  imported  into  Europe  from 
South  America,  and  the  best  from  Para ;  but  of  late  years  a  considerable  quantity 
has  been  brought  from  Java,  Penang,  Sincapore,  and  Assam.  About  twelve  years 
ago,  Mr.  William  Griffith  published  an  interesting  report  upon  the  Ficus  elcutiea, 
the  caoutchouc  tree  of  Assam,  which  he  drew  up  at  the  request  of  Captain  Jenkins, 
agent  in  that  country  to  the  Governor-General  of  India.  This  remarkable  species 
of  fig-tree  is  either  solitary,  or  in  twofold  or  threefold  groups.  It  is  larger  and 
more  umbrageous  than  any  of  the  other  trees  in  the  extensive  forest  where  it  abounds, 
and  may  be  distinguished  from  the  other  trees,  at  a  distance  of  several  miles,  by 
the  picturesque  appearance  produced  by  its  dense,  huge,  and  lofty  crown.  The  main 
trunk  of  one  was  carefully  measured,  and  was  found  to  have  a  circumference  of  no  less 
than  74  feet ;  while  the  girth  of  the  main  trunk  along  with  the  supports  immediately 
round  it,  was  120  feet  The  area  covered  by  the  expanded  branches  had  a  circum- 
ference of  610  feet     The  height  of  the  central  tree  was  100  feet 

It  has  been  estimated,  after  an  accurate  survey,  that  there  are  43,240  such  noble 
ciees  within  a  length  of  30  miles,  and  breadth  of  8  miles  of  forest  near  Ferozepoor,  in 
the  district  of  Chardwar,  in  AssauL 

Lieutenant  Veitch  has  since  discovered  that  the  Ficus  elastica  is  equally  abundant  in 
the  district  of  Naudwar.  Its  geographical  range  in  Assam  seems  to  be  between  25 
deg.  10  min.  and  27  deg,  20  min.  of  north  latitude,  and  between  90  deg.  40  min.  and 
96  deg.  30  min.  of  east  longitude.  It  occurs  on  the  slopes  of  the  hills,  up  to  an  eleva- 
tion of  probably  22,600  feet     This  tree  is  of  the  banyan  tribe,  famed  for  its  pillared 


.160 


CAOUTCHOUC. 


CAOUTCHOUC.  ' 


361 


m  i 


i  \v 

M  \i\  1 

i  H 

ji 

l! 

i 

m  I 


shade,     whose  daughters  grow  about  the  mother  tree,"  which  has  furnished  the  motu 
tot  rami  quot  arhores,  to  the  Royal  Asiatic  Society.     Species  of  this  genus  afford  crate^ 
luisnade,  however,  in  the  tropical  regions  of  America,  as  well  as  Asia 

Many  species  of  other  trees  yield  a  milky  tenacious  juice,  of  which  birdlime  has 
r-5!L""^^?"  ^  ^^1^'  5'  ^^^'^f^r/'n*  inlegrifolia,  and  Lakoocha,  Ficu,  indica  and 
reh^osa,  also  F.  Tnela,  Rozburghii,  glamerata,  and  oppodtifolicu  From  some  of  these 
an  mferior  kmd  of  caoutchouc  has  been  obtained. 

The  juice  of  the  Mcus  elastica  of  Chard  war  is  better  when  drawn  from  the  old  than 
from  the  young  trees,  and  richer  m  the  cold  season  than  in  the  hot.     It  is  extracted  bv 
^n^  7  »^f  «<>"8  a  foot  apart,  across  the  bark  down  to  the  wood,  all  round  the  trun£ 
and  also  the  large  branches,  up  to  the  very  top  of  the  tree ;  the  quantity  which  exud^ 
increasmg  with  the  height  of  the  incision.    The  bleeding  may  be  safel/ repeated  once 
DurZwhifr^  i.    ^l  ^."^^'  ^  fresh  drawn,  is  nearly  of  the  consistencJof  cream,  and 
?aJ«  iTrn],,;.  ^""'I*"!*!  "^T  ^^^^  ^^^^  *  ''^^"'^  (*2  lbs.)  is  reckoned  to  be  the  ave 
mfunds  of  injf  each  bleeding  of  one  tree;  or  20,000  trees  will  yield  about  12.000 
maunds  of  juice :  which  is  composed  m  10  parts,  of  from  4  to  6  parts  of  water,  anl 
of  course  from  6  to  4  parts  of  caoutchouc.     The  bleeding  should  be  confined  to  the 
in  tirhottoX  "''  *'  ""'''''"  "''^  ^^  "^^'^"^'  '^^  "^S^^«-  vegetZn  ofthe  tree' 
Mr.  Griffith  says,  that  the  richest  juice  is  obtained  from  transverse  incisions  made 
nto  the  wood  of  the  larger  reflex  roots,  which  are  half  exposed  abov^^i'ounT  and  that 
^proceeds  from  the  bark  alone.     Beneath  the  Une  of  indsions,  the  natWes  of  Aslam 

lanru  rudely  folded  up  into  the  shape  of  a  cup.  He  observes  that  the  various  species 
of  Teiranthera,  upon  which  the  Moonga  silkworm  feeds,  as  also  the  castor  oil  nJant 
which  IS  the  ch  ef  food  of  the  Eria  silkworm,  do  not  afford  a  milky  caoutchouc  ]^e 
Hence  It  would  appear  that  Dr.  Royle's  notion  of  caoutchouc  forming  a  necerarv 
Z'iw  ?/^' -r-  ^^  '^^^^r^  «°<i  being  "in  some  way  employed  in  gS 
tenacrty  to  their  silk,"  seems  to  be  unfounded.  If  Botany  discountenances  this^  dea^ 
Chemistry  would  seem  to  scout  it  altogether;  for  silk  contains  11-33  per  cent  of  azote' 
and  caoutchouc  contains  none  at  all ;  being  simply  a  solid  hydro-carburet  and  there- 
fore widely  dissimilar  in  constitution  to  silk,  ^hfch  consist^  of  oxygen  a4%4  azote 
11;33,  carbon  50-69,  and  hydrogen  3-94  in  100  parts.  ^^  ' 

aJ^  J'J'^^^-^^f.^^ure*  emulsion  is  of  common  occurrence  in  the  orders  Enphorbiacea 
and  i..W,  which  may  be  looked  on  as  the  main  sources  of  caoutchouc.     The  Ame 
ncan  caoutchouc  is  said  to  be  furnished  by  the  Siphmia  dastica,  or  the  Mevea  oTa- 
nensts  of  Aublet,  a  tree  which  grows  in  Brazil,  an5  also  in  Surinam  ^ 

in  1  fi?^.  t^ti  models  of  cylinders,  of  li  to  2^  inches  in  diameter,  and  4  or  6  inches 
m  length,  to  both  the  Asiatic  and  Agricultural  Societies  of  Bengal,  to  serve  as  patterns 
for  the  natives  to  mould  their  caoutchouc  by.  Mr.  Griffith  siys  that  this  pkn  of 
forming  the  caoutchouc  into  tumblers  or  bottlesf  as  recommended  W  the  commi^^^^^^^^  of 

Shb:  oZ' d'^t  9^<^^'f^-^^rP--J^  ->  in  l^i«  opinion.  thV^^r  that' can 
possibly  be  offered ;  being  tedious,  laborious,  causing  the  caoutchouc  to  be  blackened 
in  the  (Jrying,  and  not  obviating  the  viscidity  of  the  juice  when  it  is  exposed  to  the 
IZ\  A  ^f  «™"iend8.  as  a  far  better  mode  of  treating  the  juice,  to  work  it  up  with 
the  hands,  to  blanch  it  in  water,  and  then  subject  it  to  pressure  I  shall  pre^seTtlv 
describe  a  still  better  method  which  has  receitly  occurred  to  me,  in  experCndn^ 
upon  the  caoutchouc  juice.  This  fluid,  with  certain  precautions  chiefly  exXs  SI 
long  tiie  ^*«nth,may  be  kept  in  the  state  of  a  creamy  emulsio/for  a  very 

NEW  EXPERIMENTAL   EESEARCHES   ON  CAOUTCHOUC. 

The  specific  gravity  of  the  best  compact  Para  caoutchouc, 

taken  in  dilute  alcohol,  is 0-941567 

The  specific  gravity  of  the  best  Assam  is        -        -        -  094297 2 

»  „  Sincapore      -        -         -  0.936650 

»  „  Penang  -        -        -  0-919178 

Having  been  favoured  by  Mr.  Sievier,  formerly  managing  director  of  the  Joint-Stock 
Caoutchouc  Company,  and  by  Mr  Beale,  engineer,  with  two  different  samples  of  cao^^ 
chouc  juice,  I  have  subjected  each  to  chemical  examination 

That  of  Mr.  Sievier  is  greyish  brown,  that  of  Mr.  Beale  is  of  a  milky  grey  colour- 
^e  deviation  from  whiteness  m  each  case  being  due  to  the  presence  of  aloetlc  matter 
which  accompanies  the  caoutchouc  m  the  secretion  by  the  tree.  The  former  iuice  is  of 
the  consistence  of  thm  cream,  has  a  specific  gravity  of  104125,  and  yields,  by  exposi^e 
upon  a  porcelain  capsule,  in  a  thm  layer,  for  a  few  days,  or  by  boiW  for  a  1^^! 
nutes  with  a  little  water,  20  per  cent,  of  solid  caoutchouc.    The  latter,  though  it  his  the 


consistence  of  pretty  rich  cream,  has  a  specific  gravity  of  only  1-0175.  It  yields  no 
less  than  37  per  cent,  of  white,  solid,  and  very  elastic  caoutchouc. 

It  is  interesting  to  observe  how  readily  and  compactly  the  separate  little  cloths  or 
threads  of  caoutchouc  coalesce  into  one  spongy  mass  in  the  progress  of  the  ebullition, 
particularly  if  the  emulsive  mixture  be  stirred ;  but  the  addition  of  water  is  necessary 
to  prevent  the  coagulated  caoutchouc  from  sticking  to  the  sides  or  bottom  of  the  vessel 
and  becoming  burnt  In  order  to  convert  the  spongy  mass  thus  formed  into  good 
caoutchouc,  nothing  more  is  requisite  than  to  expose  it  to  moderate  pressure  between 
the  folds  of  a  towel.  By  this  process  the  whole  of  the  aloetic  extract,  and  other  vege- 
table matters,  which  concrete  into  the  substance  of  the  balls  and  junks  of  caoutchouc 
prepared  in  Assam  and  Java,  and  contaminate  it.  are  entirely  separated,  and  an  article 
nearly  white  and  inodorous  is  obtained.  Some  of  the  cakes  of  American  caoutchouc 
exhale  when  cut  the  foetor  of  rotten  cheese ;  a  smell  which  adheres  to  the  threads  made 
of  it,  after  every  process  of  purification. 

In  the  interior  of  many  of  the  balls  which  come  from  both  the  Brazils  and  East  In- 
dies, spots  are  frequently  found  of  a  viscid  tarry-looking  matter,  which,  when  exposed 
to  the  air,  act  in  some  manner  as  a  ferment,  and  decompose  the  whole  mass  into  a  soft 
substance,  which  is  good  for  nothing.  Were  the  plan  of  boiling  the  fresh  juice  along 
with  its  own  bulk  of  water,  or  a  little  more,  adopted,  a  much  purer  article  would  be 
obtained,  and  with  comparatively  less  trouble  and  delay,  than  has  been  hitherto  brought 
into  the  market. 

I  find  that  neither  of  the  above  two  samples  of  caoutchouc  juice  affords  any  appear- 
ance of  coagulum  when  mixed  in  any  proportions  with  alcohol  of  0-825  specific  gravity ; 
and,  therefore,  I  infer  that  albumen  is  not  a  necessary  constituent  of  the  juice,  as  Mr. 
Faraday  inferred  from  his  experiments  published  in  the  2l8t  voL  of  the  Journal  of  the 
Royal  Institution. 

The  odour  of  Mr.  Sievier's  sample  is  slightly  acescent,  that  of  Mr.  Beale's,  which  is 
by  far  the  richer  and  purer,  has  no  disagreeable  smell  whatever.  The  taste  of  the 
latter  is  at  first  bland  and  very  slight,  but  eventually  very  bitter,  from  the  aloetic  im- 
pression upon  the  tongue.  The  taste  of  the  former  is  bitter  from  the  fii-st,  in  conse- 
quence of  the  great  excess  of  aloes  which  it  contains.  When  the  brown  solution  which 
remains  in  the  capsule,  after  the  caoutchouc  has  been  separated  in  a  spongy  state  by 
ebullition,  from  100  grains  of  the  richer  juice,  is  passed  through  a  filter  and  evaporated, 
it  leaves  4  grains  of  concrete  aloes. 

Both  of  these  emulsive  juices  mix  readily  with  water,  alcohol,  and  pyroxilic  spirit^ 
though  they  do  not  become  at  all  clearer ;  they  will  not  mix  with  caoutcJioucine  (the 
distilled  spirit  of  caoutchouc),  or  with  petroleum-naphtha,  but  remain  at  the  bottom  of 
these  liquids  as  distinct  as  mercury  does  from  water.  Soda  caustic  lye  does  not  dis- 
solve the  juice ;  nitric  acid  (double  aquafortis)  converts  it  into  a  red  curdy  magma. 
The  filtered  aloetic  liquid  is  not  affected  by  the  nitrates  of  baryta  and  silver ;  it  affords 
with  oxalate  of  ammonia  minute  traces  of  lime. 

L      CAOUTCHOUC    MANUFACTURE. 

This  department  of  operative  industry  has,  within  a  few  years,  acquired  an  importance 
equal  to  that  of  some  of  the  older  arts,  and  promises,  ere  long,  to  rival  even  the  ancient 
textile  fabrics  in  the  variety  of  its  designs  and  applications.  The  manufacture  of 
caoutchouc  has,  at  present,  three  principal  branches : — 1.  The  condensation  of  the  crude 
lumps  or  shreds  of  caoutchouc,  as  imported  from  South  America,  India,  <fec.,  into  com- 
pact homogeneous  blocks,  and  the  cutting  of  these  blocks  into  cakes  or  sheets  for  the 
stationer,  surgeon,  shoemaker,  <fec.  2.  The  filature  of  either  the  India-rubber  bottles, 
or  the  artificial  sheet  caoutchouc,  into  tapes  and  threads  of  any  requisite  length  and 
fineness,  which  being  clothed  with  silk,  cotton,  linen,  or  woollen  yarns,  form  the  basis 
of  elastic  tissues  of  every  kind.  3.  The  conversion  of  the  refuse  cuttings  and  coarser 
qualities  of  caoutchouc  into  a  viscid  varnish,  which,  being  applied  between  two  sur- 
faces of  cloth,  constitute  the  well-known  double  fabrics,  impervious  to  water  and  air. 

I.  The  caoutchouc,  as  imported  in  skinny  shreds,  fibrous  balls,  twisted  concretions, 
cheese-like  cakes,  and  irregular  masses,  is,  more  or  less,  impure,  and  sometimes  fraudu- 
lently interstratified  with  earthy  matter.  It  is  cleansed  by  being  cut  into  small  pieces, 
and  washed  in  warm  water.  It  is  now  dried  on  iron  trays,  heated  with  steam,  while  being 
carefully  stirred  about  to  separate  any  remaining  dirt,  and  is  then  passed  through,  be 
tween  a  pair  of  iron  rolls,  under  a  stream  of  water,  whereby  it  gets  a  second  washing, 
and  becomes  at  the  same  time  equalized  by  the  separate  pieces  being  blended  together. 
The  shreds  and  cuttings  thus  laminated,  if  still  foul  or  heterogeneous,  are  thrown  back 
int-o  a  kind  of  hopper  over  the  rolls,  set  one-sixteenth  of  an  inch  apart,  and  passed  se- 
veral times  through  between  them.  The  above  method  of  preparation  is  that  practised 
by  Messrs.  Keene  and  Co.,  of  Lambeth,  in  their  excellent  manufactory,  under  a  patent 
granted  in  October,  183fi,  to  Mr.  Christopher  Nickels,  a  partner  in  the  firm. 

Vol.  L  3  a 


862 


CAOUTCHOUC. 


In  the  great  establishment  of  the  Joint-Stock  Caoutchouc  Comnanv  at  T«f*o«k 
originally  under  the  direction  of  Mr.  Sievier,  a  gentle^n  disSsYed  L  IpI^^^ 
genius  and  taste  as  a  sculptor,  than  by  his  constructive  tulpnfatK^  ?         ^^  .^"* 

and  lamination  are  superseded  by  a  prCeWw^^^^ 

K'^'^""'   T^"""/,^  ''']'^  the-;„i-^,  or,  as  it  shfu^d^te Vi^p^^^^^^ 

kneading.     The  mill  employed  for  agglutinatine  or  ineornor^f  Jn/t  k/I^    f  f^      '  ^"® 

and  shreds  of  caoutchouc  Into  homogeneourelast  c  bin   -f  ^^  i  T^^^^ 

of  cast  iron,  8  or  9  inches  in  diametefLTol  tlL't^d'trVvSf ^^^^^^^      o'fT 

horizontal  axjs  (also  8  or  9  inches  Ion*?)  bv  a  shnft  ^f  Jl!     ^^f]  ■         ^      .,  ""^  **'  *** 

d^t.u1^kt^^e  :!'!:! ^:t:^:r*^'""'''  "e--'  tl>«  «voIvmg  a™^.      Fiv?  pounds 
elastic  lump,  though  a  bad  conductor  of  heat,  cannot  be  safely  touched  witrthehaiid 

nf  f^riS^  ^^'^  steaming  much  muddy  water  runs  off  through  apertures  in  the  bottom 
iJtfi    Ta  •  l""  *^'  ^r?""?^  ^^  ^^^*'  ^"  ^^'^^'^  trituration  the  various  pLces  becom^ 
nfwflr^     "J*^''  ««^^  ,«J««tic,  ovoid  ball,  of  a  reddish  brown  colour^  This  baJl  is 
now  transferred  into  another  similar  iron  drum,  where  it  is  exposed  to  th;  pricking  and 
kneading  action  of  3  sets  of  chisel  points,  6  in  each  set,  that  project  from  the  revoh^n^ 
bv  five  «f?f ;?       'V'f  .'"  T^  ""'^T'  "°^  "*^^^*^  ^"^^"^t/r  the  resistance  occLtn"! 
dJ^m     Het  fh7/    ri*''^^  standing  obliquely  upwards  from  the  bottomT?he 
drum.     Here  the  caoutchouc  is  kneaded  dry  along  with  a  little  quickhme      It  soon 
gets  yery  hot;   discharges  n  steam  through  the  punctures,  the  water  and  a  r  which  U 
Sact'^'.nd'-  "^  ^'T't''^  ^"^^^"^  operation  ;  becomes  in  consequence  m^re  com 
&uri;/«l1    ?•    r"^  T  hour  assumes  the  dark  brown  colour  of  stationers'  rubbed 
Duiing  all  this  time  frequent  explosions  take  place,  from  the  expansion  and  sudden 
extrication  of  the  imprisoned  air  and  steam.  ^  suaden 

«hfiT  ^^'^  T'^'^i  '^^^"^  ?'^'"''  ^^^  ^"^^  ^«  transferred  into  a  third  set,  whose  revolving 
shaft  being  turnished  both  with  flat  pressing  bars,  and  parallel  sharp  chisekperS 
dicular  to  It,  exercises  the  twofold  operation  of  pricking  and  kneading  the  mai  so  as 
to  condense  the  caoutchouc  into  a  homogeneous^^ solid.  ^  Seven  of  the!  finS  Zul 
we  ghing  as  above  stated,  6  pounds  each:  are  then  introduced  into  a  much  W^^^^^ 
drum  of  8im.lar  construction,  but  of  much  greater  strength,  whose  shaft  is  stufded  aU 

Civ  inborn  ^T,^.^^^'  '"''^^  ^^  ^^"^^  '^^'^^^  ^ere  the  'separate  balls  become  per- 
fectly  incorporated  into  one  mass,  free  from  honeycomb  cells  or  pores,  and  therefore  fit 
for  be.ng  squeezed  into  a  rectangular  or  cylindrical  form  in  a  sultabl^  cast-iron  mould 
by  the  action  of  a  screw-press.  When  condensed  to  the  utmost  in  this  box,  th^lid  i^ 
secured  m  its  place  by  screw-bolte,  and  the  mould  is  set  aside  for  severa  days  I  is  a 
curious  fact,  that  Mr.  Sievier  has  tried  to  give  this  moulding  force,  by  the^  1  ydrailiS 
press,  without  effect,  as  the  cake  of  caoutchouc,  after  being  so^condensed,  res  {s  much 
Z^ZT"'^T^V}''''l.^^''''  ^^'  compressing  action  of^the  screw.  The  cake  form 
generally  preferred  for  the  recomposed,  ground,  or  milled  caoutchouc,  is  a  rectanS 
mass,  about  18  inches  long,  9  inches  broad,  and  6  inches  thick.  ^ 

This  18  sliced  into  cakes  for  the  stationer,  and  into  sheets  for  making  tapes  and  threads 
of  caoutchouc,  by  an  ingemous  self-acting  machine,  in  which  a  straifht  steel  blade  with 
Its  edge  slanting  downwards,  is  made  to  vibrate  most  rapidly  to  and  fro  in  a  horizontal 

SZJiT^  t'^''^^?^V^^J'^'^^"S  "^^^P"^  ^'  embraced  at  each  side  between  two 
8t  ong  iron  bars^  18  slowly  advanced  against  the  blade  by  screw-work  like  that  of  the 
slide-rest  of  a  lathe.    In  cuttmg  caoutchouc  by  knives  of  every  form,  it  is  essential  that 


CAOUTCHOUC. 


363 


either  the  blade  or  the  incision  be  nraboC:Jfa1gh?vt^^^^^^ 
tool  would  immediately  stu^k  fast  f  ^^J^f^^^^^^f^^^^^^^^^  up^over  the  blade  in  pro- 

downwards,  the  sheet  which  it  cuts  off  ^P^^^/^^/.'^'^J-te  The  thicker  slices  are  after- 
portion  as  it  isdetached  from  the  bottom  mass  of  the  ^  ^^^  ,^^  .^ationer. 

^ards  cut  bv  hand,  with  a  7"«^,  ^"f^^^V  Unes  Fn  a  wooden  frame.  The  whole- 
the  sections  teing  guided  ^ftangularlj  by  saw  lines  m  ^^^  ^^  ^  ^^^^^  ^^^ 

sale  price  of  these  is  now  reduced  to  2«.  per  pound  S^^^^^^^  mechanism  that  acts 

desired  degree  of  thinness,  ^y  ^'^:'' ZiomTlCfskeand  raises  it  by  any  aliquot 
agaiDst  a  board  which  supports  the  ^«^^^,^°j/^„^^fv^^t^^^^^^^  in  the  same  horizontal 
pLt  of  an  inch,  the  cutting  blade  being  caused  ^^J^'^.t  clXhou^  and  they  serve 
Diane     These  thin  slices  constitute  what  is  called  sheet  ^f^^^^^^^^^^  ki„d ;  since. 

Clbly  for  making  tubes  for  P-^™^ J^  ^PP^^^^^^^^  coalesce. 

^^y  fhei."  or  by  inflation  of  a  W  -  tube  ^^^^  ^-^Irse  lumps  of  caoutchouc,  into 
^The  mode  of  recomposing  the  ^^f,^"^^^^^^^^^^^^^  ^^^^^^  October  24, 

a  homogeneous  elastic  cake,  specified  J^y  f ;;  ^^f  ^^^^^  ^xhe  cylinders  of  his  miU 

1836,  is'not  essentially  ^^^^'^^'^l^^'^^^^^  not  require  the  washing 

are  more  capacious,  are  open  ^^/^^l^/^f;,;^^^^^  '  evious  lamination  and  rinsing, 
apparatus,  as  the  caoutchouc  ^»%^^^f."\'^.?^^pen  cylinder,  within  the  space  of  about 
He  completes  the  kneading  «P«^//;«^^^°  *^^',  ^aU  into  the  cheie  form,  in  a 

two  hours,  and  afterwards  sq«fzes  the  lar^e  ball  so^r^  succeeds  perfectly  in  making 
mould  subjected  to  the  action  of  an  Wj'^^^^r^^^^  in^its  ph/sical  constf- 

compact  cikes  in  this  way,  his  «2"^^^;;^:rW^^^^  He  uses  a  press  if  the  power  of 
tution  from  that  recomposed  by  Mr.  ^if^^^^/J^J^^.d  suddenly  but  progressively,  at 
10  tons;  such  pressure,  however  -J^ -\^^^^\P^^^^^^  is  Jom- 

intervals  of  two  or  three  minutes  ^^^7^«;^^^^^^^^f;;'^^^^^^^  till  it  is  cold,  when  he 
plete.  he  suffers  the  caoutchouc  to  ^^^^"^^fj^f^  ^d  in  the  slide-rest  mechanism, 

Z  iilTaTa^S^^^  '-^-'  -'  --'--'-'  '' 

Mr!  Beale  engineer.  Church-lane.  WhitechapeL 

n.  FILATURE  OF  CAOUTCHOUC  FOR  f  ™^  ^^.^f  J^.^t'Tlong  ago  as  the 
Messrs.  Rattier  and  Guibal  mounted  in  f  ?Jj/jf  3,',^*,^^^^^^    Tcontfauous  fillet 
-  year  1826  or  1827.  a  machine  for  cutting  a  disc  of  <^««"tchouc  m  ^^  j 

Spirally,  from  its  circumferen^^^^  \X'ubbe  t^^^^  iTo^mfufd  Ihave  desc^iLd  thg 
the  bottom  part  of  a  bottle  ^^^^^^^J^^^^^^  machine  on  the  same  principle  was  made 
machine  under  the  article  Elastic  Bands^^  A  m^^^^^^  Manchester,  February  1ft. 

the  subject  of  a  paten   M/^' JP^^"^/^^^^^^^^^^  of  Manchester  workman- 

1836;  and,  being  constructed  ^f^ijjf^^^]  i^^7^ttF^  a  disc  of  caoutehouc,  from  the 
ship,  it  has  been  ^^^l^VelertrfsK  nto  one  Continuous  length  of  tape.  For 
circumference  towar^s^epen^^^^^^^^  ^  ^^^^^^  ^^  India-rubber  of  good  quality 

the  service  of  this  °\*^'''^^' "T  ^^  -^_^  ^y  i^eat  and  pressure  into  a  nearly  round 
being  selected,  is  cut  off  ^^^  flattened  ^Jj^  V^  ^^^^^^  ^    ^  ^^ew  nut  and 

cake  of  uniform  thickness  ™.  ^f  1^ '1  ""^i^^^h  may  be  made  to  revolve  with  any 
washer  to  the  end  of  a  ^«"^«°*f  J^.f  ^^^^^^  at  the  same  time  that  the 

desired  veWty  by  means  of  appropr^^^^^^^^  Pfbracircutrr  knife  of  cast  steel,  made  to 
edge  of  the  disc  of  «^«^^.^„^7/ .'„\*Xne  at  right  angles  to  that  of  the  disc,  and  to 
revolve  3000  times  ^er  mmute,  in  a  F^^^^f  J^f^^ ^  Continuous  uniform  tape  or  fillet 

advance  upon  ita  axis  progrXe^y^e  ^\^^V-^\Z  cutting  operation,  the  Wife  and 
from  the  circumference  of  the  cake.  YV^""f,  ,  ^  ^^  if  ^ater.  A  succession 
caoutchouc  are  ^e/. constantly  ^^^^^^  «  ^  .^  .^ 

of  threads  of  any  desired  .^f ^  V^^^^^^^J^^^^^^^  edge  of  a  revolving  steel  disc.  This 
moist  state  through  a  guide  ^l^t,  against  the  «/^^^P/^f  ^^  -^^  ^mM.  Rattier  and 
operation  is  dexterously  ^^0"^  d  Pe^^^^^^  fmChalifm  consisting  of  a  series 
Guibal  employed^  at  tl^e  ab«ve  mennon^^^^^      ^  distances,  regulated  by 

of  circular  steel  kmves,  fixed  Pf^.*"^;,\V*r^^  of  knives  acted  against  another 

interposed  washers  upon  a  revolving  shaft ,  "^hicl^series  ol  ^^J^^^  »        J^      ^^^  ^ 

Itilar  series,  placed  upon  ^P-^^;!  ^^^^^^  '  An  improved  m^ificatiS; 

throughout  its  lengt^^^"^«.^'g^^J^  Wed  i^the  spedfication  of  Mr.  Nickels's  patent 
ff  ^obTmt  ^  ntmptys  it  fof  rllngtS^threads  the  tapes  made  from  the 
recomposed  caoutchouc.  .  ^  j-      ,v.v.^^    on^  in  general  any  hollow  cylinder  of 


364 


CAOUTCHOUC. 


nu^  80  as  to  traverse  from  rfghrtTlefrby  tts  ^^^^^^^^^  "^  «  fi^ed 

moist,  revolves  upon  a  shaft  parallel  to  the  preTed^.r;.  ^  ^J'-^^^f.r  disc  of  steel,  kept 
cut  through  the  caoutchouc,  so  that  bv  thi^tm!.!!^'  '"''^  *  ^]'*^°^^  ^^^"^  ^^  *«  ^ 
the  hoUow^ylinder  is  cut  sVrall^ttoVLnJ^^^^^^^  'Sf^^"'''."  «^^^> 

thickness  of  the  side  of  the  cjlindfer.  Mr  Spk  hL  i  ^k  *^^'*^^^^'^  f^ual  to  the 
ing  hollow  cylinders  of  recomposed  caou^houcTfir^ht  ^"'""^^^  H''.  °^^thods  of  form- 
by  such  a  machine.  ^         caoutcnouc,  for  the  purpose  of  being  cut  into  fillets 

It  is  probable  that  the  threads  formed  from  f}i«  i^^o*  T  jt-       i.^^      ,      , 
from  Para,  are  considerably  strongS^  than  Tho^^^  ^^*"^^^'  as  imported 

and  therefore  much  better^  adaptfd  for  makW  Mr^'  ^'?°^.  recomposed  caoutchouc, 
When,  however,  the  kneading  operation  has  b  Jn  ^tf 'li''^'''  T*""*.  "^^'^^^  «*»^<i«g^ 
threads  of  the  ^rounrf  eaoutcL^'^  Tt  is  incorr^^^^^^^^^  ^  f"^  *^^*  ^^^ 

well  for  every  ordinary  purpose  of  elaRHn  fT^  ^  J^^  ^^  *^^  workmen,  answer 
economical,  fiim  the  m^uc'h  Zl  lAf:Ttl!:'^:tliT  "^'  ^'  ^^""^'  ^^^^^^^  ^^e 
scisstll^d^'trn"^^^^^^^  Pan^^^^^^^^  broken  ends  obliquely  with 

grease  or  moisture  within  the  junctfonliLkl!^»f"^^  ^^^'1^  '^^^  *«  ^diit  no 
elasticity  before  they  can  be  made  sub  erWeJ^to  Inv  f '  ^^^  ^"  ^^P"^^^  «^  ^^^^^ 
Each  thread  is  in^/aiiea<.rf  individuaCfn  the  ae^^  ""^^i    "^^      manufacture, 

pressing  it  between  the  moist  thumb  a Jd  finder  so  fjnff  ^l  *.^'  1%""^^'  ^^^^  "^  ^^^1 
ite  natural  length,  whDe  it  is  drawn  rnnJ.liwf'  f  ^  ^^'"^^"^^  *^  *^  ^^  ^^ast  eight  times 
the  power-drivl\eel.    T^is  e'Xsb'^^a^^^^^^^^^^  ^3:  the  rolition  o? 

chouc,  and  with  very  considerable  dLLa^Pmfnf  r  iT  .  <^«°^«?sation  of  the  eaout- 
son's  Journal  upwards  of  30  years  a^  bvirrn,^  \T^3  P/^°^"^  ^"<^  ^^  ^^i<^l»ol- 
daL  I  attempted  to  stretch  the  threfd  i?  JJe  ..^5  '  *^-  ^^'?^  Philosopher  of  Ken- 
of  heat  too  painful  for  my  unseasoned  fingeil  tL  re^Wff '  ^^'-^"""^  '^'  ^^"^^^^^^ 
with  the  thread,  are  laid  aside  for  some  K  ni  I'  *^^^'"  ^*'"S  completely  filled 

of  the  caoutchouc,  the  recoZosed  re^uirfniV^^^^^  ""'  ^'"^"5  according  to'^the  quality 
When  thus  rendei-ed  ineLtTcrit  is  wound  fffin.f]  ^M -"^  *^"  ^  '^  ^^^^^^  °^^t«"al 

^r  :t^r;arr  ''  ^-^-^^'  -  -- ""^^^^^^^^^^^^^ 

of llltl>i^eTo?tiir^^^^^^^^^^^^^^^  caoutehouc  being  first 

machine.  For  this  purpose  they  are  strefched  h v  S  •  ^*?  '^'^^'^.  "P''^  *^«  braiding 
reel,  to  7  or  8  times  thdr  natu/al  lenS  and  l/ft  twf'oM^'  *'*  ^^  ^^/^^^°&  "P«°  ^^^ 
tension  upon  the  reels.  Thread  husfJ^/aS^hr.  T  ''^'^•'  ^^  ^^'^^  ^^^^e  of 
0-948732;  but  when  it  has  its  Istli  rmt^rel^  ft^T  .t^T^'^.^^°«  ^^««  ^^an  * 
state,  by  rubbing  between  the  war^  palms  of  Ve^nni^  ''^T^  *«  '''  P"«tine 
same  piece  of  thJeadis  reduced  to  0^259  sT  ThUnh  '  the  specific  gravity  of  the 

in  the  process  of  wire-drawing  where  the  Lno'  t  ''T''  ^^^^^^  '^  that  exhibited 
tie,  while  it  disengages  much  helt  whioh  7^!^  ^'T  g«<?  condensed,  hard,  and  brit- 
intolerable  to  un/i/etisedTnge^  ^s'at veteXtd '^^  ''"^'  ^^  '^^^  ^  ^  <^^^- 
^^l-iX'LtCalatT^^^  '^  --^-ed  from  1  to  8 

the  pound  weight^.  Ind  '"  8.^7o,  being^  a  t "  l^rfiThrtd^  "^TH  V*^^  ''''  ^^ 
for  the  finer  elastic  tissues,  as  for  ladies' ^ol/tZiMi  ^^^.^^^'  The  finest  is  used 
The  ropes  made  by  Mr.  sLvferwthSest^^^^^^^  elastic  bracelets  and  bands, 

hemp  and  workedin  his  gigantic  brai<S.lma^^^^^^^^^^  ""^  '^'^  ^^?7^  *i^^"^^^  ^^^^hed  with 
by  heat,  an  extraordinafyTrenith  an/ 1«^  '. '  possess,  after  they  are  re-elasticated 
direction  of  all  the  sti  an/s,  can  f^ndft  ,'.  «I  7  ^^'  1'!^..^'^°'  *.^'  "^^^^^^  rectilinear 
cordage  of  like  diameter  ^      ^  '*'^  *^^"^^'  ^^^  '^'^^  «f  the  best  patent 

to'the'Tbbof  loo'^:  arHtltryt£%tl"n  '  '^^!^T^  ^^^^^^  ^  «<^-rtiog 
genius  of  the  patentee,  TSr  Thcfrt  S,  r^'"^'  advantage  the  mechanical 
the  following  8tatement:-50r4;ds  of  1  ifoh  h".  ^""^  ^'''^''^  "^^^  ^"  ^"^^^^-^^  from 
ribbon  loom,  whereby  the  femXipSatiVe  whn\«  ''f,  .^^\^7«?  ^^^klj  in  one  18 
matic  movements,  earns  10^  a  week  300O  vlrl^^^^^ o'^^^ul  ^  *^^  '^"^  ^'^^^^^  ^^^  auto- 
similar  loom  in  the  same  time.  Butane  ot"  Mr  SievtpV^^^^  ^T''  '^''  ^^"^°  "P«^  * 
tions  is,  that  of  producing,  by  the  shrinking  of  thl  J  !  T'^  ?"^""  P^^^""^  "^^^n- 
tion  or  warp  of  the  stuff,  the^apXan^  oVrais.d  fi'^'^'^'J'  *^"«^«  '"  ^^^  ^«""^a- 
lace,  in  theVeft     Thus,'  by  a  S^r^h^icrot^  tt^^^^^^^  ^«^^^- 

expense  of  one  penny,  an  effect  which  could  not  b^  effeS  h^       'i  produeed,  at  an 
ess  than  one  shilling.  ettected  by  mechanical  means  fox 


CAOUTCHOUC. 

m.     OK  THE  WATER-PBOOF   DOUBLE   FABRICS. 


365 


The  parings,  the  waste  of  the  kneading  operations  above  described,  and  the  coarsest 
QuauL^s  Sported  caoutchouc,  such  as  the  inelastic  lumps  from  Para,  are  worked  up 
To  varnbh^^^^^^^^^^  two  surfaces  of  cloth  are  cemented,  so  as  t.)  forni  a  compound 
fabric  impervious  to  air  and  water.  The  caoutchouc  is  dissolved  either  m  petroleum 
(luar^naphtha.  or  oil  of  turpentine,  by  being  triturated  with  either  of  the  solven^m 
a  close  cast-iron  vessel,  with  a  stirring  apparatus,  moved  by  mechanical  power  The  heat 
generated  during  the  attrition  of  the  caoutchouc,  is  suflicient  to  favour  the  solution 
wXut  the  application  of  fuel  in  any  way.  Tliese  triturating  cymders  have  been  called 
puc-mills  by  the  workmen,  because  they  are  furnished  with  obliquely  pressing  and  re- 
volving arms,  but  in  other  respects  they  differ  in  construction  Ihev  are  4  feet  in 
diameter  and  depth,  receive  13  cwt.  at  a  time,  have  a  vertical  revolving  shaft  of  wrought 
iron  4  inches  in  diameter,  and  make  one  turn  in  a  second.  Three  days  are  required  to 
complete  the  solution  of  one  charge  of  the  varnish  materials.  The  proportion  ot  the 
solvent  oils  varies  with  the  object  in  view,  being  always  much  less  m  weight  than  the 

caoutchouc.  .   ,  .  -,■,■>•   3'        1,^    :*■ 

When  the  varnish  is  to  be  applied  to  very  nice  purposes,  as  bookbinding,  Ac,  it 
must  be  rubbed  into  a  homogeneous  smooth  paste,  by  putting  it  m  a  hopper,  and 
letting  it  fall  between  a  couple  of  parallel  iron  rolls,  set  almost  in  contact 

The  wooden  frame-work  of  the  gallery  in  which  the  water-proof  cloth  is  manufactured, 
ihould  be  at  least  50  yards  long,  to  give  ample  room  for  extending,  airing,  and  drying 
the  pieces;  it  should  be  2  yarfs  wide,  and  not  less  than  5  high     It  js  formed  of  ui^ 
right  standards  of  wood,  bound  with  three  or  four  horizontal  rails  at  the  sides  of  the 
ends.     At  the  end  of  the  gallery,  where  the  varnish  is  applied,  the  web  which  is  to  be 
smeared  must  be  wound  upon  a  beam,  resembling  m  size  and  situation  the  cloth  beam 
of  the  weaver's  loom.     This  piece  is  thence  drawn  up  and  stretched  m  a  horizontal 
direction  over  a  bar,  like  the  breast  beam  of  a  loom,  whence  it  is  extended  m  a  some- 
what slanting  du-ection  downwards,  and  passed  over  the  edge  of  a  horizontal  bar 
Above  this  btr,  and  parallel  to  it,  a  steel-armed  edge  of  wood  is  aajusted  so  closely  as 
to  leave  but  a  Harrow  slit  for  the  passage  of  the  varnish  and  the  cloth.    Ihis  horizontal 
slit  may  be  widened  or  narrowed  at  pleasure  by  thumb-screws,  which  lower  or  raise 
the  movable  upper  board.     The  caoutchouc  paste  being  plastered  thickly  with  a  long 
spatula  of  woo^upon  the  down-sloped  part  of  the  web,  which  hes  between  the  breast- 
beam  and  the  above  described  slit,  the  cloth  is  then  drawn  through  the  slit  by  means  ot 
cords  in  a  horizontal  direction  along  the  lowest  rails  of  the  gallery,  whereby  it  gets 
uniformly  besmeared.     As  soon  as  the  whole  web,  consisting  of  about  40  yards,  is  thus 
coated  with  the  viscid  varnish,  it  is  extended  horizontally  upon  rollers,  in  the  upper 
part  of  the  gallery,  and  left  for  a  day  or  two  to  dry.    A  second  and  third  coat  are  thea 
applied  in  succession.     Two  such  webs,  or  pieces,  are  next  cemented  face  to  face,  by 
nassine  them,  at  the  instant  of  their  being  brought  into  contact,  through  between  a 
pair  of  wooden  rollers,  care  being  taken  by  the  operator  to  prevent  the  formation  of  any 
creases,  or  twisting  of  the  twofold  web.    The  under  one  of  the  two  pieces  bein^  intended 
for  the  lining,  should  be  a  couple  of  inches  broader  than  the  upper  one  to  insure  the 
uniform  covering  of  the  latter,  which  is  destined  to  form  the  outside  of  the  garment 
The  double  cloth  is  finally  suspended  in  a  well-ventilated  stove-room,  till  it  becomes 
drv  and  nearly  free  from  smell.     The  parings  cut  from  the  broader  edges  of  the  under 
piece,  are  reserved  for  cementing  the  seams  of  cloaks  and  other  articles  of  dress.     The 
tape-like  shreds  of  the  double  cloth  are  in  great  request  among  gardeners,  tor  nailing 
UP  the  twigs  of  wall  shrubs. 

Mr  Walton  of  Sowerby-bridg^,  has  recently  substituted  sheet  India-rubber  for 
leather  in  the  construction  of  fillet  cards  for  the  cotton  and  tow  manufactures.  The 
superior  elasticity  of  this  article  is  said  to  prove  advantageous  in  several  respects. 

Mr  Charles  Keene,  proprietor  of  the  extensive  and  well-organized  India-rubber 
factory  in  Lambeth,  obtained  a  patent  in  March,  1840,  for  applying  a  coat  of 
caoutchouc  to  the  outer  surface  of  flexible  leather.  The  varnish  of  caoutchouc, 
made  with  oil  of  turpentine,  has  so  much  lampblack  incorporated  with  it,  as  to  bring 
it  to  the  consistence  of  dough.  The  edge  of  the  doe-skin,  buck-skin,  and  wash- 
leather  being  introduced  between  a  pair  of  wetted  iron  rollers,  as  much  of  the  India- 
rubber'compound,  softened  by  a  gentle  heat,  and  rolled  into  a  proper  length  as  will 
cover  the  leather,  is  laid  in  the  hollow  between  the  leather  and  the  moist  cylindei-s. 
By  their  rotation,  the  coating  is  evenly  effected.  When  the  surface  has  become  dry,  it 
mav  be  embossed  or  gilt,  and  varnished  over  with  a  solution  of  shellac,  with  a  little 
Venice  turpentine,  in  alcohol.  After  two  or  three  applications  of  this  kind,  the  leather 
is  passed  through  a  pair  of  iron  rollers,  either  smooth  or  embossed.  AV  hen  made  up 
articles,  such  as  shoes  or  portmanteaus,  Ac,  are  to  be  covered,  the  India-rubber  varnish 
is  used  in  a  thinner  state. — Newton's  Journal^  xxiii.  357. 


366 


CAOUTCHOUC. 


CAPSTAN. 


367 


i 


CamUchouc  gulphnred— Mr.  Burke  in  describing  his  patented  process  for  vulcanizing 
india-rubber,  says,  that  he  avoids  two  principal  defects  of  the  usual  article,  viz.  its 
efflorescence  of  sulphur  with  an  offensive  odour,  and  its  consequent  decomposition  and 
becoming  rotten.  He  employs  crude  antimony  (the  sulphuret  of  that  metal  in  fine 
powder),  and  converts  it  by  boiling  in  water  with  soda  or  potash  (carbonates)  into  the 
orange  sulphuret  of  that  metal  (Kermes  mineral)  by  the  addition  of  hydrochloric  acid 
to  the  fluid  in  slight  excess.  He  combines  this  compound  (after  being  well  washed) 
with  caoutchouc  or  guttA  percha,  either  together  or  separately,  according  to  the  degree 
of  elasticity  which  he  wishes  to  obtain.  This  mixture  is  afterwards  subjected  to  a  heat 
of  from  250°  to  280°  Fahr.  He  masticates  the  caoutchouc  in  the  usual  iron  box  by 
means  of  the  kneading  fluted  revolving  rollers,  subjecting  the  whole  to  heat  The 
antunonial  compound  is  then  added  in  quantities  varying  from  5  to  15  lbs.,  according  to 
the  strength  and  elasticity  required  in  the  compound.  At  the  end  of  from  one  to  two 
hours  trituration,  the  block  is  removed  from  the  box,  and  while  in  a  warm  state  it  is 
strongly  compressed  in  an  iron  mould;  and  after  being  under  pressure  for  a  day  or  two 
18  subjected  to  a  steam  heat  for  a  couple  of  hours.  The  block  thus  prepared  may  now 
be  cut  into  sheets,  and  afterwards  divided  into  threads,  or  formed  into  such  other  articles 
as  are  desired. 

The  patentee  also  mixes  the  flock  of  silk,  cotton  or  wool,  with  liquefied  caoutchouc 
and  applies  this  compound  for  waterproofing  cloth,  previously  coated  with  the  ordinary 
water-proof  composition.     He  also  proposes  to  strengthen  the  gutta  percha  bands  for 
driving-pulleys  by  affixing  strips  of  leather  to  their  edges;  and  to  apply  metal  tips  or 
shields  to  the  gutta  percha  heels  and  soles  of  boots  and  shoes. 

The  clamminess  of  Caoutchouc  is  removed  by  Mr.  Hancock  in  the  following 
manner :  10  pounds  of  it  are  rolled  out  into  a  thin  sheet  between  iron  cylinders,  and 
at  the  same  time  20  pounds  of  French-chalk  (silicate  of  magnesia)  are  sifted  on  and 
incorporated  with  it,  by  means  of  the  usual  kneading  apparatus.  When  very  thin  films 
are  required  (like  sheets  of  paper)  the  caoutchouc,  made  plastic  with  a  little  naphtha, 
18  spread  upon  cloth  previously  saturated  with  size,  and  when  dry  is  stripped  off.  Mix- 
tures of  caoutchouc  so  softened  may  be  made  with  asphalt^  with  pigments  of  various 
kinds,  plumbago,  sulphur,  <fec. 

Tlie  improvements  patented  in  January,  1849,  by  Mr.  Christopher  Nickels,  consist 

1.  In  a  modification  of  the  grinding,  kneading  or  masticating  machine,  by  furnishing 
its  roller  with  flanges  at  its  two  ends  to  prevent  the  rubber  from  coming  against  the 
ends  of  the  cylinder.  When  sulphur  is  to  be  kneaded  into  it  in  the  process  of  vul- 
canizing  the  rubber,  as  it  is  called,  he  covere  in  the  trough,  but  not  otherwise.  He 
has  also  given  an  excentric  action  to  his  roller. 

He  kneads  with  his  rubber  flowers  of  sulphur,  or  compounds  thereof,  in  the  proportion 
of  10  pounds  of  sulphur  to  60  pounds  of  caoutchouc,  and  he  subjects  the  compound  to 
pressure  in  moulds.  He  prefei-s  to  treat  the  caoutchouc  with  the  fumes  of  sulphur,  or 
^ses  containing  sulphur,  in  order  to  make  a  combination  in  the  kneading  cylinder. 
He  uses  a  retort  to  distil  the  vapour  of  sulphur  upon  the  rubber  in  the  cylinder  heated 
m  a  steam  jacket  He  also  occasionally  introduces  hydrogen  or  phosphorus  along  with 
it  The  compound  mass  thus  obtained  is  to  be  subjected  to  hydraulic  pressure,  in  the 
moulds,  heated  to  about  220°  or  250°  Fahr.  He  causes  the  blocks  to  undergo  a  rolling 
motion  under  heavy  pressure  by  machinery ;  the  effect  of  which  motion  is  to  equalize 
the  sulphur  diffused  in  the  blocks.  Even  thread  of  the  ordinary  India-rubber,  when 
agitated  in  a  box  with  flowers  of  sulphur,  is  said  to  be  glazed  and  improved  thereby. 
— Newton! s  Journal,  xxxv.  21. 

'^i*.^  porosity  of  caoutchouc  explains  the  readiness  with  which  it  is  permeated 
by  different  liquids  which  have  no  chemical  action  upon  it  Thin  sections  of  dry 
caoutchouc  of  the  best  kinds  absorb  from  18  to  26  per  cent  of  water  in  the  course 
of  a  month,  and  become  white  from  having  been  brown.  The  best  solvent  is  a  mixture 
of  100  parts  of  sulphuret  of  carbon  with  from  6  to  8  parts  of  anhydrous  alcohol.  If 
the  alcohol  be  mixed  with  a  little  water  a  dough  is  obtained,  from  which  the  caoutchouc 
may  be  drawn  out  into  threads  and  spun.  By  Gerard's  process,  gutta  percha  is  also 
soluble  in  the  above  mixtures  of  sulphuret  of  carbon  and  alcohol. 

The  sulphuration  of  caoutchouc,  a  valuable  invention,  is  due  to  Mr.  Charles  Goodyear 
of  New  York.  The  process  of  cold  sulphuring  of  Mr.  Parkes  consists  in  plunging  the 
sheets  or  tubes  of  caoutchouc  in  a  mixture  of  100  parts  of  sulphuret  of  carbon,  and  2i 
parts  of  protochloride  of  sulphur,  for  a  minute  or  two,  and  then  immersing  them  in 
cold  water.  Thus  supersulphuration  is  prevented  in  consequence  of  decomposing  the 
chloride  of  sulphur  on  the  surface  by  this  immersion,  while  the  rest  of  the  sulphur 
passes  into  the  interior  by  absorption.  Mr.  Parkes  prescribes  another,  and  perhaps  a 
preferable  process,  which  consists  in  immersing  the  caoutchouc  in  a  closed  vessel  for 
3  houi-s,  containing  a  solution  of  polysulphuret  of  potassium  indicating  a  density  of 
25°  Beaume,  at  the  temperature  of  248°  Fahr.,  then  washing  in  an  alkaline  solution, 
and  lastly  in  pure  water.     A  uniform  impregnation  is  thus  obtained. 


CAPERS,  are  plucked  before  they  open,  and  thrown  into  strong  vinegar  slightly 
salted,  where  they  are  pickled.  The  crop  of  each  day  is  added  to  the  same  vinegar 
tub,  so  that  in  the  course  of  the  six  months  during  which  the  caper  shrub  flowers,  the 
vessel  gets  filled,  and  is  sold  to  persons  who  sort  the  capers  (the  smallest  being  most 
valued)  by  means  of  copper  sieves.  This  metal  is  attacked  by  the  acid,  wherefrom  the 
fruit  acquires  a  green  colour,  much  admired  by  ignorant  connoisseur^. 

CAPSTAN.    (Cabestan,  Fr. ;  SpiUe,  Germ.)    A  machine  whereon  the  Ciible  is  wound 
successively  in  weighing  the  anchor  of  a  vessel.     It  is  a  species  of  wheel  and  axle ;  tlie 
axle  being  vertical,  and  pierced  with  holes  near  its  top  for  the  insertion  of  the  ends  of  hor- 
izontal levers,  called  handspikes,  which  represent  the  wheel     These  are  turned  by  the 
force  of  men  moving  in  a  circle.     The  power  applied  to  the  lever  is  to  the  resistance  to 
be  overcome,  (the  weight  of  the  anchor,  for  example,)  when  the  forces  are  in  equilibno, 
as  the  radius  of  the  cylinder  round  which  the  cable  is  coiled  is  to  the  circumference  de- 
scribed by  the  power.    It  is  manifest  that  the  radius  of  the  axle  must  be  augmented  m 
this  computation  by  half  the  diameter  of  the  cable,  which  is  supposed  to  lie  always  one 
coil  thick  upon  it    The  force  of  a  man,  thus  applied,  has  been  commonly  estimated  as  equal 
to  the  traction  of  27  pounds  hanging  over  a  pulley.    Friction  being  so  variable  a  quantity 
in  capstans,  renders  the  exact  calculation  of  its  mechanical  effect  somewhat  uncertain.  A 
stout  man,  stationed  near  the  bottom  of  the  axle,  holds  fast  the  loose  part  of  the  cable,  which 
has  already  made  two  or  three  turns ;  and,  being  aided  by  its  friction  upon  the  wood,  he  both 
prevents  it  from  slipping  backwards,  and  uncoils  each  turn  as  it  is  progressively  made. 

Mr  Hindmarsh,  master  mariner  of  Newcastle,  obtained  a  patent,  in  February,  1827, 
for  a  Contrivance  to  enable  a  capstan  or  windlass  to  be  occasionally  worked  with  increased 
mechanical  advantage.  With  this  view,  he  placed  toothed  wheel-work,  partly  m  the 
drum-head  of  the  capstan,  and  partly  in  the  upper  part  of  the  barrel,  upon  which  the 
cable  is  coiled  and  uncoiled  in  successive  portions.  .  j,     •    .         j     ♦ 

The  drum-head,  and  also  the  barrel,  turn  loosely  upon  a  central  spmdle,  independent 
of  each  other,  and  are  connected  together  either  by  the  toothed  gear,  or  by  bolts.  Oa 
raisin*'  or  withdrawing  the  connecting  pinion  from  the  toothed  wheels,  and  then  locking 
the  d^um-head  and  barrel  together,  the  capstan  works  with  a  power  equal  only  to  that 
exerted  by  the  men  at  the  capstan-bars,  as  an  ordinary  capstan ;  but  on  lowering  the 
Dinion  into  gear  with  the  wheeT-work,  and  withdrawing  the  bolts  which  locked  the  drum- 
head to  the  barrel,  the  power  exerted  by  the  men  becomes  increased  in  proportion  to  the 
diameter  and  numbers  of  teeth  in  the  wheels  and  pinions. 

Fie.  322  is  the  external  appearance  of  this  capstan.     Fig.  323  a  honzontal  view  of  the 
toothed  gear  at  the  top  of  the  barrel.    The  barrel,  with  the  whelps  a  a  turns  loosely 

upon  a  vertical  spmdle  faxeU 
823  324    ^^,^;ss=Y=^3i_i,^  into   the  deck  of  the  vessel. 

The  drum-head  b  also  turns 
loosely  upon  the  same  spindle. 
The  circular  frame  c  c,  in^g. 
323,  in  which,  the  axes  of  the 
toothed  wheels  d  d  d  are 
mountijd,  is  fixed  to  the  cen- 
tral spindle.  The  rim  €  e  e, 
with  internal  teeth,  is  made 
fast  to  the  top  of  the  barrel ; 
and  the  pinion/,  which  slides 
upon  the  spindle,  is  connected 
to  the  drum-head. 

When  it  is  intended  to 
work  the  capstan  with  ordi- 
nary power,  the  pinion  /  is 
raised  up  into  the  recess  of 
the  drum-head,  by  means  of 
a  screw  g,  fig.  322,  which 
throws  it  out  of  gear  with  the 
toothed  wheels,  and  it  is  then 
locked  up  by  a  pin  z:  the 
bolts  h  k  are  now  introduced,  for  the  purj^se  of  fastenmg  the  drum-head  and  barrel  to- 
gether, when  it  becomes  an  ordinary  capstan. 

But  when  it  is  required  that  the  same  number  of  men  shall  exert  a  greater  P«wer,  itie 
bolts  h  are  withdrawn,  and  the  pinion  /  lowei-ed  into  gear  with  the  toothed  wheels. 
The  rotation  of  the  drum-head,  then  carrying  the  pinion  round,  causes  it  to  drive  the 
toothed  wheels  ddd;  and  these  working  into  the  toothed  rim  «  e,  attached  to  the  barrel, 
cause  the  barrel  to  revolve  with  an  increased  power. 
Thus,  under  particular  circumstances,  a  smaller  number  of  men  at  the  capstan  or 


368 


CARBON. 


CARBOM. 


369 


I 


! 


m  "tllr^iJ^'*"^/' '\^  ^'^"'^''^^  ^P^"  *^^  '*™^  principle)  will  be  enabled  to  haa. 
effected  ''  ""'  "^"^  ''^''^^'  "^^^^  ^  *''  important  object  to  £ 

n«!r.r^^^^^K^?^^'"  ?^'?'P'  obtained  a  patent  for  certain  improvements  in  capstans,  a 

m  its  IdlptaUor'"''''"  ''  ^'''''   ^'        '^"^  ^'  ^^^'  ^  P"'''^^^"'  '^°"=^  ^^'^'^^^y  ^^^^«J 

m/vir'  ^'■"'^k'  ',^'P-r«f ''  ^?  ^^s  <=yst^"'  patented  in  1833,  instead  of  applying  the 
moving  power  by  handspikes,  having  fixed  two  rims  of  teeth  round  the  top  of  [he  cap! 
Stan,  acts  upon  them  by  a  rotatory  worm,  or  pinions  turned  by  a  winch 

nnrilt^htA'  fiv.'i'r*'?\''M^^^'T^^"'  ^."^•^^-  258  is  a  horizontal  lop  view :  a  is  an 
upnght  shaft  fixed  firmly  to  the  deck,  serving  as  an  axle  round  which  the  body  of  the 
capstan  revolves.  A  frame  c,  fixed  to  the  top  of  a  stationary  shaft  a,  above  the  b^y  of 
the  capstan,  carries  the  driving  apparatus.  ^ 

The  upper  part  of  the  body  of  the  capstan  has  a  ring  of  oblique  teeth  d  formed  round 
Its  edge ;  and  above  this,  on  the  top  of  the  capstan,  is  a  rin-  of  beve  teethT  A^ori 

trtlth'o''r{h"""'!?  "  ^'^  ^^  '^^"1  ^'  ^^^  ^"-"^  -  enSless  scrlw,wh  ch  takt'n?; 

fnd\n  the  frlp?^     '•^"'^  I  '^'7'"-^"  ^'  ^^^"^  '''  *>^^""?^«  ^'^  ^he  central  shaft  a^ 

Thp  li^   ""^  r\f  "u^^  bevel  pinion,  which  takes  into  the  bevel  teeth  of  the  rin-  e, 

,nlth-      r!!"'.?^  ?'  '^^^  *^^'"  l^^  ^°P  ^'•^"^'  ^^^  i'^  Ion?  slots,  with  angular  returns 
something  Ike  the  fastening  of  a  bayonet,  which  is  for  the  purpose  of  enablinTthe  S 

tL  L7e1  of  ttt"  r  •  •"'  -^  T'  "^'^  ^'?  ''''''  ''  ^^ '^^"?  '^  ••  th«  outer'b  aringof 
the  axle  g  of  the  bevel  pinion  is  also  supported  in  the  frame  c,  in  a  similar  wav  in  order 

to  put  It  m  and  out  of  gear  with  the  teeth  of  the  bevel  ring  e.    A  mode  of  S'in"  Se^ 
^essential;    because  the  two  toothed  rings,  and  their  drying  worm  and  pS^^ 
different  speeds  and,  of  course,  cannot  be  both  in  operation  atfhe  same  time!^        '  ^ 

The  worm  of  the  shaft  /,  being  placed  in  gear  with  the  teeth  of  the  rin-  d  on  aDolv 
ing  rotatory  power  thereto,  by  means  of  winches  attached  to  the  ends  of^h^  shaft  th^ 
tZt  ^'  ^fL"^  l^^  "^^''^'^  T"'  ^"  "^^^^  ^^  ^^^°J^«  ^ith  a  slow  motion,  but  wiU  great 
^lL:t  tt;:dTn.^;Vay!'^  ""^^'^^  ^^'  '^  ^^^  ^-«  --^  -  -Wmen  with'c"?! 
J^Wl^'^v  f  °J^"^^^^  ^^'^  ^\^t  o^.tl^e  endless  screw  is  desired,  then  the  driving  power 

?p/r  with^fi'    K  ^  r  '"''''*'  '°  !?\^^'  ^  °^  *^"  ^^^^1  Pin'O"'  that  pinion  being  puTkS 
gear  with  the  bevel  ring  e,  and  the  endless  screw  withdrawn.    It  should,  however  b^ 

fn  Po.Tt.'^''^'  l^^^the  patentee  proposes  to  employ  two  short  axles  g,  placed  opposil^ 
to  each  other,  with  bevel  pinions  acting  in  the  bevel-toothed  ring,  though  only  one  i^ 
shown  m  the  figure,  to  avoid  confusion.  He  also  contemplates  a  modificatX^  of  the 
same  contrivance  m  which  four  short  axles  g,  placed  at  right  angles,  whp^niins 
o  /h?>;"'^  f  K"""'^  ""f '  T^  ^'  '™Pl°^"^'  ^"^  °^^d«  «ffe<^tive  in  giving  rotltonr  mo  Ln 
lurn'ed'brtttbV^^^^^^  °^"^"^^^^  ^^^^^^  '^  '^^  -^-  -^-^  ^heYxlT^S 

o^dm^Io^T  CARACT,  is  a  weight  used  by  goldsmiths  and  jewellers.    See  Assay 

CARBON  (Carbone,  Fr.;  Kohlenstoff,  Germ.),  in  a  perfectly  pure  state,  constitutes 
^^mond.  Carbonaceous  substances  are  usually  more  or  less  compound,  conlainirMS 
gen,  or  sometimes  oxygen,  and  azote,  along  with  earthy  and  me  allic  matters  CarboT 
tolerably  pure,  abounds  in  the  mineral  kingdom;  and,  in  a  combined  state  it  forms  a 
mam  constituent  of  vegetable  and  animal  bodies.  Anthracite  is  a  mineral  c^arc^^^^^ 
differing  from  common  pit-coal  in  containing  no  bitumen,  and  therefore  burning  with- 
been  e'JnnLT  v*  v^'^r  ''  '^'  carbonaceous  mass  which  remains  after  pit-coarLs 
been  exposed  to  ignition  for  some  time  out  of  contact  of  air ;  its  volatile  pkrts  havin- 

what  ttTi  V  '^'  \^f'  ^'  ''  ^i^P^^^y  substance,  of  an  iron-black  color,  a  some" 
^lat  metallic  lustre,  and  does  not  easily  burn  unless  several  pieces  are  kindled  together 

tamed  by  the  calcination  of  wood  m  close  vessels,  as  described  under  the  article  Acetic 
Ac  D  or  in  piles  of  various  shapes,  covered  with  loam,  to  screen  it  from  the  fVee  actSn 
of  the  atmosphere,  which  would  otherwise  consume  it  entirely.    See  Charcoal!    Such 

withon/' y''^'  ""''^^^^  '™'"  ""'  '""'"'^  ^^'^  ^'^''  '^'  strongest  heats  of  ou?  furnaces 
J^    Z  ,.    t    T^  '""J  '^^"=''  ^r''"^'^  ^''  ^  e'^^l^ded  :  it  is  a  bad  conductor  of  heat 
but  conducts  electricity  very  well.     When  burned,  it  unites  with  oxygen,  and  fonns  cm 
bonic  acid,  the  fixed  a.r  of  Dr.  Black,  the  choke^amp  of  the  miner.     When  tMs  Z 
bonic  acid  IS  made  to  traverse  red  hot  charcoal  it  dissolves  a  portion  of  it,  and  becomes 
carh^nicoxyde,  which  contains  only  one  half  of  its  volume  of  oxy4n-  whereas Tr 

JSll  l^^^^''  ^'  ''^  ^^^'  ^'  -^"  '•  -  -"  as't;'e%rSVenf  ^ 


Charcoal  obtained  by  the  action  of  a  rapid  fire  in  close  vessels  is  not  so  solid  ana  so 
good  a  fuel  as  that  which  is  made  in  the  ancient  way  by  the  slow  calcination  of  pyramidal 
piles  covered  with  earth.  One  of  the  most  economical  ovens  for  making  wood  charcoal 
is  that  invented  by  M.  Foucauld,  which  he  calls  a  shroud,  or  abri.  To  construct  one  of 
these,  30  feet  in  diameter  at  the  base,  10  feet  at  its  summit,  and  from  8  to  9  feet  high,  he 
forms,  with  wood  2  inches  square,  a  frame  12  feet  long,  3  feet  broad  at  one  end,  and  one 
foot  at  the  other.  The  figure  will  explain  the  construction.  The  uprights,  A  B  and 
C  D,  of  this  frame  are  furnished  with  three  wooden  handles  a  a  a,  and  a'  a'  a',  by  means 
of  which  tliey  can  be  joined  together,  by  passing  through  two  contiguous  handles  a 
wooden  fork,  the  frame  being  previously  provided  with  props,  as  shown  inyig.  326,  and 
covered  with  loam  mixed  with  grass.  A  flat  cover  of  10  feet  diameter,  made  of  planks 
well  joined,  and  secured  by  four  cross  bars,  is  mounted  with  two  trap  doors,  M  N,ytg. 
328,  for  giving  egress  to  the  smoke  at  the  commencement  of  the  operation ;   a  triangular 

C        B  32T 


al 


ag 


hole  P,  cut  out  in  the  cover,  receives  the  end  of  a  conduit  Q  R  S,  (figs.  329  and  328,) 
af  wood  formed  of  three  deals,  destined  to  convey  the  gases  and  condensed  liquids 
into  the  casks  F  G  H.  Lastly,  a  door  T,  which  may  be  opened  and  shut  at  pleasure, 
permits  the  operator  to  inspect  the  state  of  the  fire.  The  charcoal  calcined  by  this  abrif 
has  been  found  to  be  of  superior  quality. 

When  it  is  wished  to  change  the  place  where  the  abri  is  erected,  and  to  transport  it  to 
a  store  of  new-felled  timber,  the  frame  is  taken  down,  after  beating  off  the  clay  which 
covers  it,  the  joints  are  then  cut  by  a  saw,  as  well  as  the  ends  of  the  forks  which  fixed 
the  frames  to  one  another.  This  process  is  economical  in  use,  simple  and  cheap  in 
construction ;  since  all  the  pieces  of  the  apparatus  are  easily  moved  about,  and  may  be 
readily  mounted  in  the  forests.  For  obtaining  a  compact  charcoal,  for  the  use  of  artisans, 
this  mixed  process  of  Foucauld  is  said  to  be  preferable  to  either  the  close  iron  cylindei 
or  the  pile. 

For  making  gunpowder-charcoal  the  lighter  woods,  such  as  the  willow,  dogwood,  and 
alder  answer  best ;  and  in  their  carbonization  care  should  be  taken  to  let  the  vapors  free- 
ly escape,  especially  towards  the  end  of  the  operation,  for  when  they  are  re-absorbed, 
they  greatly  impair  the  combustibility  of  the  charcoal. 

By  the  common  process  of  the  forests,  about  18  per  cent,  of  the  weight  of  the  wood  is 
obtained ;  by  the  process  of  Foucauld  about  24  per  cent,  are  obtained,  with  20  of  crude 
pyrolisneous  acid  of  10  degrees  Baurae.  By  the  process  described  under  Acetic  Acid, 
27  of  charcoal,  and  18  of  acid  at  6  degrees,  are  procured  from  100  parts  of  wood,  besides 
the  tar.  These  quantities  were  the  results  of  careful  experimenting,  and  are  greater  than 
can  be  reckoned  upon  in  ordinary  hands. 

Charcoal  for  chemical  purposes  may  be  extemporaneously  prepared  by  calcining  piecec 
of  wood  covered  with  sand  in  a  crucible,  till  no  more  volatile  matter  exhales. 

The  charcoal  of  some  woods  contains  silica,  and  is  therefore  useful  for  polishing  metals. 
Being  a  bad  conductor  of  heat,  charcoal  is  employed  sometimes  in  powder  to  incase 
small  furnaces  and  steam-pipes.  It  is  not  affected  by  water;  and  hence  the  extremities 
of  stakes  driven  into  moist  ground  are  not  liable  to  decomposition.  In  like  manner  casks 
when  charred  inside  preserve  water  much  better  than  common  casks,  because  they  furnish 
no  soluble  matter  for  fermentation  or  for  food  to  animalcules. 

Lowitz  discovered  that  wood  charcoal  removes  offensive  smells  from  animal  and  vege- 
table  substances,  and  counteracts  their  pratrefaction.     He  found  the  odor  of  succinit 


370 


CARBON. 


and  benzoic  acids,  of  bugs,  of  empyreumatic  oils,  of  infusions  of  valerian,  esseare  o! 
wormwood,  spirits  distilled  from  bad  grain,  and  sulphureous  substances  were  all  absorb- 
able by  treshly  calcined  charcoal  properly  applied.  A  very  ingenious  filter  has  been  con- 
siructea  lor  purifying  water,  by  passing  it  through  strata  of  charcoal  of  different  fineness. 

♦v-^  V  ^^^'1^°^  ^  burned,  one  third  of  the  heat  is  discharged  by  radiation,  and  two 
thirds  by  conduction.  n         j  > 

r  y^^^^'^lr'!?  ^?^^^  °^  i.^^  ^"^"*^*y  ^^  charcoal  yielded  by  different  woods  was  pub- 
hshed  by  Mr.  Mushet,  as  the  result  of  experiments  carefuUy  made  upon  the  small  scale. 
He  says,  the  woods  before  being  charred  were  thoroughly  dried,  and  pieces  of  each  kind 
were  selected  as  nearly  alike  in  every  respect  as  possible.  One  hundred  parts  of  each 
sort  were  taken,  and  they  produced  as  under : — 


Lignum  Vitae 
Mahogany  - 
Laburnum 
Chestnut   - 
Oak  - 
Walnut      - 
Holly 

Beech 

Sycamore   - 

Elm  - 

Norway  Pine 

SaUow 

Ash  - 

Birch 

Scottish  Pine 


afforded  26-0  of  charcoal  of  a  grayish  color,  resembling  coke. 

-  25-4  tinged  with  brown,  spongy  and  porous. 

-  24-5  velvet  black,  compact,  very  hard. 

-  23'2  glossy  black,  compact,  fiim. 

-  22*6  black,  close,  very  firm. 

-  20-6  dull  black,  close,  firm. 

-  19'9  dull  black,  loose  and  bulky. 

-  19*9  dull  black,  spongy,  firm. 

-  19-7  fine  black,  bulky,  moderately  firm. 

-  19*5  fine  black,  moderately  firm. 

-  19-2  shining  black,  bulky,  very  soft. 

-  18-4  velvet  black,  bulky,  loose  and  sof^. 

-  17*9  shining  black,  spongy,  firm. 

-  17-4  velvet  black,  bulky,  firm. 

-  16*4  tinged  with  brown,  moderately  firm. 


Messrs.  AUen  and  Pepys,  from  100  parts  of  the  following  woods,  obtained  tU  quanti- 
kes  of  charcoal  as  under : —  o  ,  ^  ^      »». 


Beech 
Mahogany 
Lignum  Vitae 


15-00 
15-75 
17-25 


Oak 
Fir  . 
Box 


-  17'40 

-  18-17 

-  20-25 


It  IS  observable  that  the  quantities  obtained  by  Messrs.  Allen  and  Pepys  are  in  general 
less  than  those  given  by  Mr.  Mushet,  which  may  be  owing  to  Mr.  Mushet  not  having 
applied  sufficient  heat,  or  operated  long  enough,  to  dissipate  the  aqueous  matter  oC  the 
gaseous  products. 

To  those  persons  who  buy  charcoal  by  weight,  it  is  important  to  purchase  it  as  soon 
alter  it  is  made  as  possible,  as  it  quickly  absorbs  a  considerable  portion  of  water  from 
toe  atmosphere.  Different  woods,  however,  differ  in  this  respect.  Messrs.  AUen  and 
I'fli^jrs  found,  that  by  a  week's  exposure  to  the  air,  the  charcoal  of 

Lignum  Vitaj  gained 
Fir      -        .        . 
Box     - 


Beech  - 
Oak  - 
Mahogany  - 


9-6  per  cent. 
13-0  ditto. 
14-0  ditto. 
16-3  ditto. 
16-5  ditto. 
18-0     ditto. 


The  following  is  a  tabular  view  of  the  volumes  of  the  different  gases  which  were 

absorbed  m  the  course  of  24  hours,  by  one  volume  of  charcoal,  in  the  experiments  of 

^heodore  de  Saussure,  which  were  conducted  in  a  way  likely  to  produce  correct 

results.    Each  portion  of  charcoal  was  heated  afresh  to  a  red  heat,  and  allowed  to  cool 

under  mercury.     When  taken  from  the  mercury,  it  was  instantly  plunged  into  the  vessel 


Ammoniacal  gas      -  -  90 

Muriatic  acid  gas    -  -  85 

Sulphurous  acid       -  -  65 

Sulphurated  hydrogen  -  55 

Nitrous  oxyde  -        -  -  40 

Carbonic  add  gas    -  -  36 


I 


Bicarbureted  hydrogen  -  35-00 

Carbonic  oxyde      -  -  9-42 

Oxygen  gas  -        -  -  9-25 

Nitrogen       -        -  .  7-50 

Carbureted  hydrogen  -  5-00 

Hydrogen  gas         -  -  1*75 


Neumann  who  made  many  experiments  on  charcoal,  informs  us,  that  for  the  reduction 
of  the  metallic  oxydes,  the  charcoal  of  the  heavier  woods,  as  that  of  the  oak  and  the 
beech,  is  preferable,  and  that,  for  common  fuel,  such  charcoal  gives  the  greatest  heat,  and 
requires  the  most  plentiful  supply  of  air  to  keep  it  burnine;  while  those  of  the  lighter 
woods  preserve  a  glowing  heat  with  a  much  less  draught  of  air;  and  that  for  purposes 
Where  it  is  desirable  to  have  a  steady  and  a  still  fire,  charcoal  should  be  employe<l  which 


CARBONATE  OF  AMMONIA. 


371 


has  been  made  from  wood  previously  divested  of  its  bark,  sinie  it  is  the  cortical  part 
which  crackles  and  flies  off  in  sparks  during  combustion,  while  the  coal  of  the  wood 

itself  seldom  does. 

For  making  crayons  of  charcoal,  the  willow  is  the  best  wood  that  can  be  employed,  as 
the  softness  is  uniform  in  all  its  parts.  Its  durability  may  be  seen  in  several  of  our  old 
churchyards,  where  the  letters  made  with  lamp-black  are  still  perfect,  though  the  white 
lead  with  which  the  body  of  the  stones  was  painted  is  entirely  destroyed. 

This  property  of  carbon  is  shown,  however,  in  a  more  striking  manner  by  the  writing* 
that  were  found  in  the  ruins  of  Herculaneum,  which  have  retained  their  original  black- 
ness for  two  thousand  years.  The  ancients  wrote  with  ink  made  from  ground  charcoal. 
If  it  be  required  to  purify  any  carbonaceous  matter,  to  render  it  fitter  for  delicate  pig- 
ments, this  may  be  done  by  first  calcining  it  in  a  close  vessel,  and  then  lixiviating  it  in 
water  slightly  acidulated  by  nitric  acid. 

The  incorruptibility  of  charcoal  was  well  known  to  the  ancients,  and  they  availed 
themselves  of  this  property  upon  all  important  occasions. 

About  sixty  years  ago  a  quantity  of  oak  stakes  were  found  in  the  bed  of  the  Thames, 
in  the  very  spot  where  Tacitus  says  that  the  Britons  fixed  a  vast  number  of  such  stakes 
to  prevent  the  passage  of  Julius  Csesar  and  his  army.  These  stakes  were  charred  to  a 
considerable  depth,  had  retained  their  form  completely,  and  were  firm  at  the  heart. 

Most  of  the  houses  in  Venice  stand  upon  piles  of  wood,  which  have  all  been  previously 
charred  for  their  preservation.  In  this  country,  estates  were  formerly  marked  out  by 
charred  stakes  driven  to  a  considerable  depth  into  the  ground.  See  Bone-black, 
Charcoal,  and  Graphite. 

CARBONATED  WATER  is  water  either  pure,  or  holding  various  saline  matters  in 
solution,  impregnated  with  carbonic  acid  gas.  For  general  sale  in  this  country,  the 
water  usually  contains  a  little  soda,  which  being  charged  with  the  gas,  is  called  Soda 
water  ;  see  this  article  for  a  description  of  an  excellent  machine  for  the  manufacture  of 
this  fashionable  beverage. 

CARBONATES.  Saline  compounds  in  definite  proportions  of  carbonic  acid,  with  alka- 
lis, earths,  and  the  ordinary  metallic  oxydes. 

The  carbonates  principally  used  in  the  arts  and  manufactures  are  those  of  ammonia, 
copper^  iron,  had,  lime,  magnesia,  potash,  soda.  Native  carbonate  of  copper  is  the  beau- 
tiful green  mineral  called  Malachite. 

Carbonates  are  easily  analyzed  by  estimating  either  by  weight  or  measure  the  quantity 
of  carbonic  acid  which  they  evolve  under  the  decomposing  action  of  somewhat  dilute 
sulphuric,  nitric,  or  muriatic  acid  ;  for  as  they  are  all  compounds  of  acid,  and  base  in 
equivalent  proportions,  the  quantity  of  acid  will  indicate  the  quantity  of  base.  Thus, 
as  pure  limestone  consists  of  56  of  lime  and  44  of  acid,  in  100  parts,  if  upon  examining 
a  sample  of  limestone  we  find  it  to  give  out  only  22  per  cent,  of  carbonic  acid  gas,  du- 
ring its  slow  solution  in  muriatic  acid,  we  are  sure  that  there  are  only  28  parts  of  lime 
present.  I  have  described,  in  the  Annals  of  Philosophy  for  October,  18 17,  a  simple  form 
of  apparatus  for  analyzing  the  carbonates  with  equal  readiness  and  precision.  The  sim- 
ple rule  by  measure  to  which  I  was  led,  may  be  thus  stated  :  From  the  bulk  of  evolved 
gas,  expressed  in  cubic  inches  and  tenths,  deduct^,  the  remainder  will  express  the  propor- 
tion of  real  limestone  present  in  the  grains  employed.  Pure  magnesian  limestone  yields 
vcr>'  nearly  a  cubic  inch  of  the  gas  for  every  grain  in  weight. 

CARBONATE  OF  AMMONIA.  A  salt  called  in  modem  chemistry  sesqui-car- 
bonale,  to  denote  its  being  composed  of  one  and  a  half  equivalent  primes  of  carbonic 
acid,  and  one  of  ammonia.  It  consists  by  my  analysis  of  55-89  carbonic  acid,  28*86 
ammonia,  and  15-25  water,  in  100  parts.  It  is  generally  prepared  by  mixing  from  1^  to 
1|  parts  of  well-washed  dry  chalk,  with  1  of  sal-ammoniac,  introducing  the  mixture  into 
an  earthen  or  cast-iron  retort,  or  subliming  pot,  and  exposing  it  to  a  heat  gradually  raised 
to  redness.  By  double  decomposition,  the  ammonia  is  volatilized  in  combination  with  the 
car'oonic  acid  of  the  chalk,  and  the  vapors  are  received  in  a  condensing  receiver  made 
either  of  glass,  stone  ware,  or  lead.  The  chlorine  of  the  sal-ammoniac  remains  in  the 
reiort,  associated  with  the  basis  of  the  chalk  in  the  state  of  chloride  jf  calcium.  Some 
ammonia  gas  escapes  during  the  process. 

Tilt  saline  mass  thus  sublimed  is  purified  by  a  second  sublimation  in  glass  or  salt- 
glazed  earthen  vessels.  The  salt  may  be  obtained,  by  the  above  method  carefully  con- 
ducted, in  rhomboidal  octahedrons,  but  it  is  generally  made  for  the  market  in  a  compf  cl 
semi-crystalline  white  cake.  It  has  a  pungent  ammoniacal  smell ;  a  hot,  pungent,  alkv 
line  taste ;  a  strong  alkaline  reaction,  and  dissolves  in  two  parts  of  cold  water.  It  must 
be  kept  in  well-closed  vessels,  as  by  exposure  to  the  air  a  portion  of  its  ammonia  exhales, 
and  it  passes  into  the  state  of  the  scentless  bi-carbonate.  It  is  employed  much  in  medi- 
cine, chemical  analysis,  and  by  the  pastry-cooks  to  give  sponginess  to  their  cakes,  in  cohf 
sequence  of  its  volatilization  from  their  dough  in  the  oven.     See  Sal-Ammoniac. 

For  the  other  carbonates  used  in  .the  arts,  see  their  respective  bases ;  copper,  lead* 
lime,  &c. 


372 


CARBURET  OF  SULPHUR. 


CARBONIC  ACID  (Jade  carbonique,  Fr. ;  Kohlensaure,  Germ.)  consists  of  I  pnmc 
equivalent  of  carbon=6-l25-f-2  of  oxyffen=  16-026,  whose  joint  sum=22-151,  represents 
the  atomic  weight  or  combining  ratio  of  this  acid,  in  the  neutral  or  protocarbonate 
salts.     Its  composition  by  volume  is  stated  under  Carbon.    Its  natural  form  is  a  gas, 
whose  specific  gravity  is  1-5245,  compared  to  atmospheric  air   1-000;   and   being   so 
dense,  it  may  be  poured  out  of  one  vessel  into  another.     Hence  it  v/as  called  at^'fiist 
aerial  acid.    From  its  existing  copiously,  in  a  solid  state,  in  limestones  and  the  mild 
alkalis,  It  was  styled  fixed  air  by  its  proper  discoverer,  Dr.  Black.    About  one  volume 
of  It  exists  m  1000  volumes  of  common  atmospheric  air,  which  may  be  made  manifest 
*y  the  crust  of  carbonate  it  occasions  upon  the  surfa-e  of  lime  Water.     Carbonic  acid 
gas  IS  found  accumulated  in  many  caverns  of  volcanic  districts,  and  particularly  in 
the  grotto  dei  cam  at  Pausilippo,  near  Puzzuoli ;  being  disengaged  in  such  circumstances 
by  the  action  of  subterranean  fire,  and,  possibly,  of  certain  acids,  upon  the  limestone 
strata.     It   often   issues   from  fountains  in   copious   currents,   as   at   Franzensbrunn, 
near  Eger,  m   Polterbrunnen ;   near  Trier;   and   Byrreshorn.     This   acid   gas   occurs 
also  frequently  in  mines  and  weUs,  being   called  choke  damp,  from  its   suffocating 
quality.     Its  presence  may,  at  all  times,  be  detected,  by  letting  down  a  li-hted  candle, 
suspended  from  a  string,  mto  the  places  suspected  of  containing  this  mephitic  air.    It 
exists,  m  considerable  quantities,  in  the  water  of  every  pump  well,  and  gives  it  a  fresh 
and  pleasant  taste.    Water,  exposed  some  time  to  the  air,  loses  these  aerial  particles,  and 
becomes  vapid.     Many  springs  are  highly  impregnated  with   carbonic   acid  gas,   and 
form  a  sparkling  beverage;  such  as  the  Selterswasser,  from  Selters  upon  the  Lahn,  in 
the  grand  dutchy  of  Nassau ;  of  which  no  less  than  two  millions  and  a  half  of  bottles 
are  sold  every  year.     A   prodigious  quantity  of  a   similar  water  is   also   artificially 
prepared  in  Great   Britain,  and  many  other  countries,  under  the  name  of  aerated   or 
soda  water. 

Carbonic  acid  occurs  in  nature,  combined  with  many  salifiable  bases;  as  in  the 
carbonates  of  soda,  baryta,  strontia,  magnesia;  the  oxydes  of  iron,  manganese,  zinc, 
copper,  lead,  &c.  From  these  substances  it  may  be  separated,  generally  "speaking,  br 
strong  Ignition,  or,  more  readily,  by  the  superior  affinity  of  muriatic,  sulphuric,  or 
nitric  acid,  for  the  earth  or  metallic  oxyde.  It  is  formed  whenever  ve-etable  or  animal 
substances  are  burned  with  free  access  of  air,  from  the  union  cf  their  carbonaceous 
principle  with  atmospheric  oxygen.  It  is  also  formed  in  all  cases  of  the  spontaneous 
decomposition  of  organic  substances,  particularly  in  the  process  of  fermentation ;  and 
constitutes  the  pungent,  noxious,  heavy  gas  thrown  off,  in  vast  volumes,  from  beer  vats. 
See  Distillation  and  Fermentation.  Carbonic  acid  is  also  generated  in  the  breathing 
of  animals;  from  4  to  5  per  cent.,  in  volume,  of  the  inhaled  oxygen  bein?  converted,  at 
each  expiration,  into  this  gas,  which  contaminates  the  air  of  crowded  apartments  and 
renders  ventilation  essential  to  health,  and  even  to  life;  witness  the  horrible  catastronhe 
of  the  Black-hole  at  Calcutta. 

Carbonic  acid  gas  is  destitute  of  color,  has  a  sourish,  suffbcating  smell,  an  acidulous 
pungent  taste,  imparts  to  moist,  but  not  dry,  litmus  paper,  a  transient  reddish  tint,  and 
weighs  per  100  cubic  inches,  46|  grains;  and  per  cubic  foot,  803^  grains;  a  little  more 
than  3 J  oz.  avoirdupoise.  A  cubic  foot  of  air  weighs  about  two  thirds  of  that  quantity 
or  527  grams.  It  may  be  condensed  into  the  liquid  state  by  a  pressure  of  40  atmos- 
pheres, and  this  liquid  may  be  then  solidified  by  its  own  sudden  spontaneous  evapora- 
tion. If  air  contain  more  than  15  per  cent,  in  bulk  of  this  gas,  it  becomes  unfit 
for  respiration  and  combustion,  animal  life  and  candles  being  speedily  extint'uished 
by  it.  ° 

Before  a  person  ventures  into  a  deep  well,  or  vault  containing  fermenting  materials 
he  should  introduce  a  lighted  candle  into  the  space,  and  observe  how  it  burns.     Car- 
bonic acid,  being  so  much  denser  than  common  air,  may  be  drawn  out  of  cellars  or 
fermenting  tubs,  by  a  pump  furnished  with  a  leather  hose,  which  reaches  to  the  bottom 
Quicklime,  mixed  with  water,  may  be  used  also  to  purify  the  air  of  a  sunk  apartment,  by 
Its  affinity  for,  or  power  of,  absorbing  this  aerial  acid.     See  Mineral  Waters  and  Soda 

CARBONIC  OXYDE.    See  the  article  Carbon. 

CARBUNCLE.    A  gem  highly  prized  by  the  ancients ;  most  probably  a  variety  of  the 
noble  garnet  of  modern  mineralogists. 

CARBURET  OF  SULPHUR,  called  also  sulphuret  of  carbon,  and  alcohol  of 
sulphur,  IS  a  limpid  volatile  liquid  possessing  a  penetrating  fetid  smell,  and  an  acrid 
burning  taste.  Its  specific  gravity  is  1-265  ;  and  its  boiling  point  is  about  1 12°  Fahr  It 
evaporates  so  readily,  and  absorbs  so  much  heat  in  the  vaporous  state,  that  if  a  tube  con- 
tammg  quicksilver,  surrounded  with  lint  dipped  in  this  liquid,  be  suspended  in  the  re 
ceiver  of  an  air-pump  on  making  the  vacuum,  the  quicksilver  will  be  congealed  It  con 
sists  of  15-8  carbon  and  84-2  sulphur,  in  100  parts;  being  two  equivalent  primes  of  tht 
latter  to  one  of  the  former. 


CARD  CUTTING. 


373 


CARBURETED  HYDROGEN.  A  compound  of  carbon  and  hydrogen,  of  which 
ttiere  are  several  species— such  as  oil-gas,  coal-gas,  defiant  gas,  oil  of  lemons,  otto  of 
roses',  oil  of  turpentine,  petroleum,  naptha,  napthaline,  oU  of  wine,  caoulchoucme,  and 

** CARDS,*  PLAYING.  {Cartes  a  jou&r,  Fr. ;  Karten,  Germ.)  Mr.  de  la  Rue  obtained^ 
in  February,  1832,  a  patent  for  certain  improvements  in  the  manufacture  of  playing 
cards,  which  he  distributed  under  three  heads ;  first,  printing  the  pips,  and  also  the  picture 
or  court  cards,  in  oil  colors  by  means  of  types  or  blocks ;  secondly,  effecting  the  same  ir 
oil  colors  by  means  of  lithography ;  and  thirdly,  gilding  or  sUveiing  borders,  and  other 
parts  of  the  characters,  by  the  printing   process,   either   by  types,  blocks,   or   lilho- 

In  the  ordinary  mode  of  manufacturing  playing  cards,  their  devices  are  partly  produced 
by  copperplate  printing,  and  they  are  filled  up  with  water  colors  by  the  means  called 

The  patentee  does  not  propose  any  material  alteration  in  the  devices  or  forms  u^-on  ihe 
cards  but  only  to  produce  them  with  oil  colors ;  and,  to  effect  this,  he  follows  precisely 
the  same  mode  as  that  practised  by  calico  printers. 

A  set  of  blocks  or  types  properly  devised,  are  produced  for  printing  the  different  pips 
of  hearts,  diamonds,  spades,  and  clubs,  or  they  are  drawn,  as  other  subjects,  in  the  usual 
way  upon  stone.  The  ink  or  color,  whether  black  or  red,  is  to  be  prepared  from  the 
best  French  lamp-black,  or  the  best  Chinese  vermilion  ground  in  oil,  and  laid  on  the 
types  and  blocks,  or  on  the  stone,  in  the  same  way  as  printers'  ink,  and  the  impressions 
taken-on  to  thick  drawing  paper  by  means  of  a  suitable  press  in  the  ordinary  manner  ol 

printing.  ,       ,  ,  •        /.  •  •        •    j/r 

The  picture  or  court-cards  are  to  be  produced  by  a  series  of  impressions  m  ditlerent 
colors,  fitting  into  each  other  exactly  in  the  same  way  as  in  printing  paper  hangings,  or 
silks  and  calicoes,  observing  that  all  the  colors  are  to  be  prepared  with  oil. 

For  this  purpose  a  series  of  blocks  or  types  are  to  be  provided  for  each  snbiect,  and 
which,  when  put  together,  will  form  the  whole  device.  These  blocks  are  to  be  used  sepa- 
rately, that  is,  all  the  yellow  parts  of  the  picture,  for  instance,  are  to  be  printed  at  one 
impression,  then  all  the  red  parts,  next  all  the  flesh  color,  then  the  blue  portions,  and  so 
on,  finishing  with  the  black  outlines,  which  complete  the  picture. 

If  the  same  is  to  be  done  by  lithography,  there  must  be  as  many  stones  as  there  are 
to  be  colors,  each  to  print  its  portion  only ;  and  the  impression,  or  part  of  the  picture 
given  by  one  stone,  must  be  exactly  fitted  into  by  the  impression  given  from  the  next  stone, 
and  so  on  until  the  whole  subject  is  complete. 

A  superior  kind  of  card  is  proposed  to  be  made,  with  gold  or  silver  devices  m  parts 
of  the  pictures,  or  cold  or  silver  borders  round  the  pips.  This  is  to  be  effected  by 
printing  the  lines  which  are  to  appear  as  gold  or  silver,  with  gilders'  size,  in  place  of 
ink  or  color ;  and  immediately  after  the  impression  has  been  given,  the  face  of  the  card 
is  to  be  powdered  over  with  gold  dust,  silver,  or  bronze,  by  means  of  a  soft  cotton  or 
wool  dabber,  by  which  the  gold,  silver,  or  bronze  will  be  made  to  adhere  to  the  picture, 
and  the  superfluous  portions  of  the  metal  will  wipe  off  by  a  very  slight  rubbing.  When 
the  prints  are  perfectly  dry,  the  face  of  the  card  may  be  polished  by  means  of  a  soft 

If  it  should  be  desirable  to  make  these  improved  cards  to  resemble  ivory,  that  may  be 
done  by  preparing  the  face  of  the  paper  in  the  first  instance  with  a  composition  of  size 
and  fine  French  white,  and  a  drying  oil,  mixed  together  to  about  the  consistency  of  cream ; 
this  is  to  be  washed  over  the  paper,  and  dried  before  printing,  and  when  the  cards  are 
finished  they  will  exactly  resemble  ivory. 

The  only  thing  remaining  to  be  described,  is  the  means  by  which  the  successive  impres- 
sions of  the  types,  blocksp  or  stones,  forming  the  parts  of  the  pictures,  are  to  be  brought 
exactly  to  join  each  othev,so  as  to  form  a  perfect  whole  design  when  complete;  this  is  by 
printers  called  registerine,  and  is  to  be  effected  much  in  the  usual  way,  by  points  in  the 
tympan  of  the  press,  or  by  marks  upon  the  stones. 

The  parts  of  the  subject  having  been  all  accurately  cut  or  drawn  to  fit,  small  holes  are 
to  be  made  with  a  fine  awl  through  a  quire  or  more  of  the  paper  at  once,  by  placing 
upon  the  paper  a  gauge-plate,  having  marks  or  guide-holes,  and  by  observing  these,  the 
same  sheet  laid  on  several  times,  and  always  made  to  correspond  with  the  points  or 
marks,  the  several  pails  of  the  picture  must  inevitably  register,  and  produce  a  perfect 

subject.  ,  .       „  .  J  •  .      r 

CARD  CUITING.  Mr.  Dickinson's  patent  machine  for  cutting  cards,  consists  of 
a  pair  of  rollers  with  circular  revolving  cutters,  the  edges  of  which  are  intended  to  act 
against  each  other  as  circular  shears,  and  the  pasteboards  in  passing  between  these 
rollers  are  cut  by  the  circular  shears  into  cards  of  the  desired  dimensions.  These  rollers 
are  mounted  in  suitable  standards,  with  proper  adjustments,  and  are  made  to  revolve  by 


374 


CARDS. 


CARDS. 


375 


■  band  and  pulley  connected  to  the  axle  of  a  crank,  or  by  any  other  convenient 
means. 

Fig.  330  is  a  front  view  ol 
this  machine;    a  a  and  bb 
are    the    two    rollers,    the 
upper     one     turning    upon 
an   extended  axle,    bearing 
in  the  standards,  the  lower 
one   upon    pivots.      These 
rollers    are    formed    by    a 
series    of    circular    blocks, 
between    a    series    of   cir- 
cular steel    cutters,   which 
are      slidden     on     to    iron 
shafts,    and    held    together 
_  upon    their    axle   by    nuts 
^  screwed  up  at   their  ends. 
The     accurate    adjustment 
of  the    cutlers    is    of  the 
first    importance    to    their 
correct    performance;    it  is 
therefore    found    necessary 
to  introduce  spiral   springs 
within  the  blocks,  in  order 
.  to  press  the  cutters  up   to 

their  proper  beanngs.    A  section  of  one  of  the  blocks  is  shown  at  Jig.  332,  and  an  end 
"new  of  the  same  at  fig.  333,  with  the  spiral  springs  inserted. 

At  the  outer  extremity  of  the  axle  of  the  roller  a^a  risger  c,  is  attached,  whence  a  band 
passes  to  a  pulley  d.  on  the  crank  shaft «,  to  which  a  fly-wheel/,  is  affixed,  for  the  purpose 
of  rendering  the  action  uniform.  Rotatory  motion  being  given  to  the  crank  shaft,  the 
npper  roller  is  turned,  the  lower  roller  moving  at  the  same  time  by  the  friction  against  the 
edges  of  the  cutters. 

Fig.  331  is  an  end  view  of  the  rollers,  showing  the  manner  in  which  the  pasteboards 
are  guided  and  conducted  between  the  cutlers.  In  the  front  of  the  machine  a  moveable 
frame  g,  is  to  be  placed,  for  the  purpose  of  receiving  the  pasteboards,  preparatory  to  cut- 
ting them  into  cards,  and  a  stop  is  screwed  to  this  frame  for  the  edge  of  the  pasteboard  to 
bear  against,  which  stop  is  adjustable  to  suit  different  sizes.  From  the  back  part  of  this 
frame  an  arm  A,  extends,  the  extremity  of  which  acts  against  the  periphery  of  a  ratchet 
wheel  t,  fixed  at  the  end  of  the  roller  b,  and  hence,  as  the  roller  goes  round,  the  frame  is 
made  to  rise  and  fall  upon  its  pivots,  for  the  purpose  of  guiding  the  pasteboard  up  to  the 
cutters ;  at  the  same  time  a  rod  fc,  hanging  in  arms  from  the  sides  of  the  standards  (shown 
by  dots  in  fig.  330),  falling  upon  the  pasteboard,  confines  it,  while  the  cutters  take  hold, 
and  racks  corresponding  with  the  indentations  of  the  rollers  are  placed  as  at  /  /,  by  means 
of  which  the  cards,  when  cut,  are  pushed  out  of  the  grooves. 

As  7drious  widths  of  cards  will  require  to  be  cut  by  this  machine,  the  patentee  pro- 
poses to  have  several  pairs  of  rollers  ready  adjusted  to  act  together,  when  mounted  in  the 
standards,  in  preference  to  shifting  the  circular  cutters,  and  introducing  blocks  of  greater 
or  less  width. 

The  second  part  of  the  invention  is  a  machine  for  pasting  the  papers,  and  pressing 
the  sheets  together  to  make  pasteboard.  This  machine  consists  of  several  reels  (we 
suppose  rollers  are  intended)  on  which  the  paper  is  to  be  wound,  along  with  a  paste 
trough,  and  rotatory  brushes.  The  several  parts  of  this  machine,  and  their  operations  in 
making  pasteboard,  are  described  in  the  specification,  but  the  patentee  having  omitted 
the  letters  of  reference  in  the  drawing  which  he  has  enrolled,  it  becomes  difficult  to 
explain  it. 

As  far  as  we  are  enabled  to  understand  the  machine,  it  appears,  that  damped  paper  is 
to  be  wound  upon  two  rollers,  and  conducted  from  thence  over  two  other  rollers ;  that  two 
fluted  rollers  revolving  in  the  paste  trough  are  to  supply  paste  to  two  circular  brushes, 
and  that  by  those  brushes  the  papers  are  to  be  pasted  upon  one  side,  and  then  pressed  to- 
gether, to  make  the  pasteboard ;  after  this,  the  pasteboard  is  to  be  drawn  on  to  a  table, 
and  to  remain  there  until  sufficiently  dry  to  be  wound  upon  other  rollers.  By  comparing 
this  description  with  the  figure,  perhaps  the  intended  operations  of  the  machine  may  be 
discovered :  it  is  the  best  explanation  we  are  enabled  to  give. 

CARDS  (Cardes,  Fr. ;  Kardeuj  Germ.)  are  instruments  which  serve  to  disentangle 
the  fibres  of  wool,  cotton,  or  other  analogous  bodies,  to  arrange  them  in  an  orderly  la^ 
or  fleece,  and  thereby  prepare  them  for  being  spun  into  uniform  threads.  The  finenesf 
and  the  levelness  of  the  yam,  as  well  as  the  beauty  of  the  cloth  into  which  it  enters. 


deoend  as  much  upon  the  regularity  and  perfection  of  the  cardmg,  as  upon  any  subsequent 
oocration*  of  the  factory.     The  quality  of  the  carding  depends  more  upon  that  ol  the 
cards  than  upon  any  attention  or  skiU  in  the  operative ;  since  it  is  now  nearly  an  automa 
tic  nrocess,  conducted  by  young  women  called  card-tenters. 

Cards  ax^e  formed  of  a  sheet  or  fillet  of  leather  pierced  with  a  multitude  of  smaQ  hol^, 
in  which  are  implanted  small  staples  of  wire  with  bent  projecting  ends  called  teeth. 
Thus  every  piece  of  wire  is  double  toothed.  The  leather  is  afterwards  applied  to  a  flat 
or  cvHndrical  surface  of  wood  or  metal,  and  the  co-operation  of  two  or  more  such  sur- 
faces constitutes  a  card.  The  teeth  of  cards  are  made  thicker  or  slenderer,  according  as 
its  filaments  to  be  carded  are  coarser  or  finer,  stifi'er  or  more  pliant,  more  valuable  or 
cheaper.  It  is  obviously  of  great  importance  that  the  teeth  should  be  all  alike,  equably 
distributed,  and  equally  inclined  over  the  surface  of  the  leather,  a  degree  of  precision 
which  is  scarcely  possible  with  handwork.  To  judge  of  the  difficulty  of  this  manipu- 
Ulion  we  need  only  inspect  the  annexed  figures.  The  wire  must  first  be  bent  at  ngJif 
angles  in  c  and  d,  fig.  336,  then  each  branch  must  receive  a  second  bend  m  a  and  6  at  a 
determinate  obtuse  angle,  invariable  for  each  system  of  cards.  It  is  indispensable  that 
the  two  angles  c  a  «  and  d  6  /  be  mathematically  equal,  not  only  as  to  the  twin  teeth  of  one 
staple,  but  through  the  whole  series ;  for  it  is  easy  to  see  that  if  one  of  the  teeth  be  more 
or  less  sloped  than  its  fellow,  it  will  lay  hold  of  more  or  less  wool  than  it,  and  render  the 
cardin*'  irregular.  But  though  the  perfect  regularity  of  the  teeth  be  imporiant  it  is  not 
the  sole  condition  towards  making  a  good  card.  It  must  be  always  kept  in  view  that  these 
teeth  are  to  be  implanted  by  pairs  in  a  piece  of  leather,  and  kept  in  it  by  the  cross  part 
ed.  The  leather  must  therefore  be  pierced  with  twin  holes  at  the  distance  c  d ;  and  pierc- 
ed in  such  a  manner,  that  the  slope  of  the  holes,  in  reference  to  the  plane  of  the  leather, 
be  invariably  the  same ;  for  otherwise  the  length  of  the  teeth  would  vary  with  this  angle 
of  inclination,  and  the  card  would  be  irregular.  •    ♦!,  *  ♦!,    i    ♦!.  . 

A  third  condition  essential  towards  producing  perfect  regularity,  is  that  the  leather 
ought  to  be  of  the  same  thickness  throughout  its  whole  surface,  otherwise  the  teeth, 
though  of  the  same  length  and  fixed  at  the  same  ande,  would  be  rendered  unequal  by  the 
different  thicknesses  of  the  leather,  and  the  operation  of  cardmg  would  be  m  consequence 

a  m     ■  *• 


a   »^ 


immmm 


336 


extremely  defective.    Fig.  334  shows  the  card  teeth  actmg  against  each  other,  as  indica- 
Sbv  the  arrows  in  two  opposite  directions ;  in  fig.  336  they  work  one  way. 

Of  lite  ^earl  very  complex  but  complete  and  well-acting  machines  have  been  con- 
structerfor  splitUng  the  leather  or  equalizing  it  by  shaving,  for  bending  and  cutt.ng  t^e 
wires  and  implanUng  them  in  the  leather,  into  holes  pierced  with  perfect  regularity. 
Card  machiiTs  which  fashion  the  teeth  with  great  precision  and  rapidity,  and  pierce  the 
lealherhave  bein  for  a  considerable  time  in  use  at  Halifax,  in  Yorkshire,  a  town  famo^ 
foflhe  excellence  of  its  card-cloth,  as  also  at  Leeds,  Glasgow,  and  several  other  places. 
The  wires  and  the  leather  thus  prepared  are  given  out  by  the  manufacturer  to  women  and 

"^Tt^^^^I^ZJ^^^' ^<i--^-^^  the  leather  which  can  be  einployed,  is  that 
wwih  I  LwTerating  in  MM.  Scrive's  automatic  card  factory  at  Lille,  the  most  magnifi- 
^nt  I  believe  LthTworld,  where  the  leather  was  drawn  forwards  by  a  roller  over  a  sobd 
Tor  zonul  table  or  b^,  and  passed  under  a  nicely  adjusted  vertical  blade  which  shaved 
?t  by  a  c  aping  motion\o  a  perfectly  uniform  thickness.  About  one  half  the  weight  of 
IhaL^hpr  u  lost  in  this  process,  and  in  the  subsequent  squarmg  and  trimming. 

The  macl^^ne  fo^  m^^^^  cards,  invented  I  believe  by  a  Mr.  Ellis  of  the  United  States, 
for  whi^h  a  first  patent  was  obtained  in  this  country  by  Joseph  Cheeseborough  Dyer,  Esq. 
S-Man  hLler  in  1811,  and  a  second  and  third  with  further  improvements  m  1814, 
arJ  1824  ifone  of  the  most  elegant  automatons  ever  applied  to  productive  industry, 
ft  s  however  necessarily  so  complicated  with  difi-erent  mechanisms  as  to  render  lU 
reDre.e2tiLa  impracticable  in  such  engravings  as  are  compatible  with  the  scope  of  th« 
dSary     I  must  therefore  content  myself  with  the  following  general  descnption  of  ito 

''tITsI  K*  to  be  done  after  having,  as  above,  prepared  the  long  sheets  or  fillets  of 
leaTherof  sSle  length,  breadth,  and  thickness  for  making  the  carfs  js  to  st^-^^^^^^^ 
leather  and  hold  it  firmly;  which  is  accomplished  by  winding  the  fil  et  of  leather  upon 
^e  roUer  or  drum^^like  thi  warp  roller  of  a  loom,  and  then  conducting  it  upwards  between 
"oilers,  to  a'receiving  or  work  roller  at  top  of  the  machine,  where  the  fillet  is  held 
^st  bv  a  cramo  bv  which  means  the  leather  is  kept  stretched.  .v  «r»»w. 

S^ondly,  the  holes  are  pierced  in  the  leather  to  receive  the  wire  staples  or  teeth  of  th^ 


! 


{ 


i 


i' 


IP 


if! 


'  V 


ifi' 

111 


t79 


CARMINE. 


eanl  by  means  of  a  sliding  fork,  the  points  of  which  are  presented  to  the  face  of  ihe 
leather ;  while  the  fork  is  made  to  advance  and  recede  continually,  by  the  agency  ol 
levers  worked  by  rotatory  cams  upon  a  revolving  main  shaA. 

The  points  of  the  fork  being  thus  made  to  penetrate  into  the  leather,  the  holes  foi 
receiving  the  staples  are  pierced  at  regular  distances,  and  in  correct  order,  by  shifting  the 
leather  fillet  so  as  to  bring  different  parts  of  its  surface  opposite  to  the  points  of  the 
sliding  fork.  Thi«  is  done  by  cams,  or  indented  wheels  and  gear,  which  shift  the  guide 
rollers  and  confining  drums  laterally,  as  they  revolve,  and  consequently  move  the  fillet  of 
leather  at  intervals  a  short  distance,  so  as  to  present  to  the  points  of  the  fork  or  piercer, 
at  every  movement,  a  different  part  of  the  surface  of  the  leather. 

Thirdly,  the  wire  of  which  the  teeth  or  points  of  the  card  are  to  be  made,  is  supplied 
from  a  coil  on  the  side  of  the  machine,  and  is  brought  forward  at  intervals  by  a  pair 
of  fsliding  pincers,  which  are  slidden  to  and  fro  through  the  agencv  of  levers  actuated  by 
rotatory  cams  upon  the  main  shaft.  The  pincers  having  advanced  a  distance  equal  to 
the  length  of  wire  intended  to  form  one  staple  or  two  points,  this  length  of  wire  is 
pressed  upon  exactly  in  the  middle  by  a  square  piece  of  steel,  and  bein^  there  confined, 
a  cutter  is  brought  forward,  which  cuts  it  off  from  that  part  of  the  wire  held  in  the  pincers. 
The  length  of  wire  thus  separated  and  confined  is  now,  by  a  movement  of  the  machine, 
t^nt  up  along  the  sides  of  the  square  steel  holder,  and  shaped  to  three  ed?es  of  the  square, 
that  IS,  formed  as  a  staple;  and  in  the  same  way,  by  the  continued  movements  of  the 
machme,  a  succession  of  pieces  of  wire  are  cut  off,  and  bent  into  staples  for  making  the 
teeth  of  the  card  as  long  as  the  mechanism  is  kept  in  action. 

Fourthly,  the  wire  staple  thus  formed  is  held  with  its  points  or  ends  outwards,  closely 
contiguous  to  the  forked  piercer  described  above,  and  by  another  movement  of  the  me- 
chanism, the  staple  is  protruded  forward,  its  end  entering'  into  the  two  holes  made  pre- 
viously in  the  leather  by  the  sliding  of  the  fork. 

While  the  wire  staple  is  being  thus  introduced  into  the  leather,  its  legs  or  points  arc 
to  be  bent,  that  is,  formed  with  a  knee  or  angle,  which  is  the  fifth  object  to  be  effected. 
This  is  done  by  means  of  a  small  apparatus  consisting  of  a  bar  or  bed,  which  bears  up 
against  the  under  side  of  the  wire  staple  when  it  has  been  passed  half  way  into  the 
holes  in  the  leather,  and  another  bar  above  it,  which,  being  brought  down  behind  the 
staple,  bends  it  over  the  resisting  bar  to  the  angle  required ;  that  is,  forms  the  knee  in 
each  leg.  A  pusher  now  acts  behind  the  staple,  and  drives  it  home  into  the  leather, 
which  completes  the  operation. 

The  leather  being  thus  conducted,  and  its  position  shifted  before  the  piercer  progres- 
Bively,  a  succession  of  the  above  described  operations  of  cutting  the  wire,  forming^  the 
staple,  passing  it  into  the  leather,  and  bending  its  legs  to  the  angular  form,  prepuces 
a  sheet  of  card  of  the  kind  usually  employed  for  carding  or  combing  wool,  cotton,  and 
other  fibrous  materials.  It  may  be  necessary  to  add,  that  as  these  wire  staples  are  re- 
quired to  be  set  in  the  leathers  sometimes  in  lines  crossing  the  sheet,  which  is  called 
ribbed,  and  at  other  times  in  oblique  lines,  called  twilled,  these  variations  are  produced 
by  the  positions  of  the  notches  or  steps  upon  the  edge  or  periphery  of  the  cam  or  in- 
dented wheel,  which  shifts  the  guide  rollers  that  hold  the  fillet  or  sheet  of  leather  as 
already  described. 

CARMINE  (Eng.  and  Fr. ;  Karminstoff,  Germ.)  is,  according  to  Pelletier  and  Cavcn- 
toa,  a  triple  compound  of  the  coloring  substance,  and  an  animal  inatter  contained  in 
cochineal,  combined  with  an  acid  added  to  effect  the  precipitation.  The  preparation  of  this 
article  is  still  a  mystery,  because,  upon  the  one  hand,  its  consumption  beinff  very  limited, 
few  persons  are  engaged  in  its  manufacture,  and  upon  the  other,  the  raw  material  being 
costly,  extensive  experiments  on  it  cannot  be  conveniently  made.  Success  in  this  basi- 
ness  IS  said  to  depend  not  a  little  upon  dexterity  of  manipulation,  and  upon  knowing  the 
instant  for  arresting  the  further  action  of  heat  upon  the  materials. 

There  is  sold  at  the  shops  different  kinds  of  carmine,  distinguished  by  numbers,  and 
possessed  of  a  corresponding  value.  This  difference  depends  upon  two  causes ;  either 
upon  the  proportion  of  alumina  added  in  the  precipitation,  or  of  a  certain  quantity  of 
vermilion  put  m  to  dilute  the  color.  In  the  first  case  the  shade  is  paler,  in  the  second  it 
has  not  the  same  lustre.  It  is  always  easy  to  discover  the  proportion  of  the  adulteration. 
By  avaUmg  ourselves  of  the  property  of  pure  carmine  to  dissolve  in  water  of  ammonia, 
the  whole  foreign  matter  remains  untouched,  and  we  may  estimate  its  amount  by  drj'ine 
the  residuum. 

To  make  Ordinary  Carmine. 
Take  1  pound  of  cochineal  in  powder ; 

3  drachms  and  a  half  of  carbonate  of  potash ; 
8  drachms  of  alum  in  powder ; 
3  drachms  and  a  half  of  fish-glue. 
The  cochineal  must  be  boiled  along  with  the  potash  in  a  copper  containing  five  paUs- 
M  of  water  (60  pints)  j  the  ebullition  being  allayed  with  cold  water.    After  boiling  a 


CARMINE. 


377 


fpw  minutes  the  copper  must  be  taken  from  the  fire,  and  placed  on  a  table  at  soch  an 
^^kL"  ttat  the  liquor  may  be  conveniently  transvased.  The  pounded  alum  is  then 
SJrown  in  and  the  decoction  is  stirred;  it  changes  color  immediately,  and  inf  ^«  \«  » 
mo?e  brUl  ant  tint.  At  the  end  of  fifteen  minutes  the  cochineal  is  deposited  at  the 
SStom  and  the  bath  becomes  as  clear  as  if  it  had  been  filtered.  It  contains  the  color- 
^  Ztlen  and  probably  a  Utde  alum  in  suspension.  We  decant  it  then  mto  a  copper  of 
^quaTcapaciiy,  and  place  it  over  the  fire,  adding  the  fish-glue  dissolved  m  a  great  deal  of 
wTer,  and  paied  through  a  scarce.  At  the  moment  of  ebul  ition,  the  cajimne  /s  per^ 
Teived  to  rise  up  to  the  surface  of  the  bath,  and  a  coagulum  is  formed,  like  what  lakes 
Dlacrin  clarifications  with  white  of  egg.  The  copper  must  be  immediately  taken  from 
Ke  fire,  and  its  contents  be  stirred  with  a  spatula.  In  the  course  of  fifteen  or  twen  y 
minutes  the  carmine  is  deposited.  The  supernatant  liquor  is  decanted,  and  the  deposiie 
mu<;t  be  drained  upon  a  filter  of  fine  canvass  or  linen.  If  the  operation  has  been  well 
conducted,  the  carmine,  when  dry,  crushes  readily  under  the  fingers.  What  remains  alter 
Se  precipitation  of  the  carmine  is  still  much  loaded  with  color,  and  may  be  employed 
very  advantageously  for  carminated  lakes.     See  Lake. 

Bv  the  old  German  process,  carmine  is  prepared  by  means  of  alum  without  any  other 
addition.  As  soon  as  the  water  boils,  the  powdered  cochineal  is  thrown  into  it,  stirred 
well  and  then  boiled  for  six  minutes;  a  little  ground  alum  is  added,  and  the  boiling  is 
continued  for  three  minutes  more;  the  vessel  is  removed  from  the  fire,  the  liquor  is  fil- 
tered and  left  for  three  days  in  porcelain  vessels,  in  the  course  of  which  lime  a  red  mat- 
ter falls  down,  which  must  be  separated  and  dried  in  the  shade.  This  is  carmine  which 
is  sometimes  previously  purified  by  washing.  The  liquor  after  three  days  :i.ore  lets  faU 
an  inferior  kind  of  carmine,  but  the  residuary  coloring  matter  may  also  be  separated  by 

%he  proVrliolTs  for  the  above  process  are  580  parts  of  clear  river  water,  16  parts  of 
cochineal,  and  1  part  of  alum;  there  is  obtained  from  1^  to  2  parts  of  carmine. 

Another  carmine  with  tartar.-To  the  boilmg  water  the  cochineal  is  added,  and  after 
some  lime  a  little  cream  of  tartar;  in  eight  minutes  more  we  add  a  little  alum,  and  con 
uZ  he  boiling  for  a  minute  or  two  longer.  Then  take  it  from  the  fire  and  pourit 
into  glass  or  porcelain  vessels,  filler,  and  let  it  repose  quietly  till  the  carmine  falls  down. 
We  then  decant  and  dry  in  the  shade.  The  proportions  are  8  pounds  of  water,  8  oz. 
of  cochineal,  ^  oz.  of  cream  of  tartar,  f  oz.  of  alum,  and  the  product  is  an  ounce  of 

^^Thel'rocess  of  Jllxon  or  LangJois,—Bo\\  two  pails  and  a  half  of  river  water  (30  pints), 
throw  into  it,  a  little  afterwards,  a  pound  of  cochineal,  add  a  filtered  solution  of  six 
drachms  of  carbonate  of  soda  and  a  pound  of  water,  and  let  the  mixture  boil  frr  half  an 
hour;  remove  the  copper  from  the  fire,  and  let  it  cool,  inclining  it  to  one  side.    Add 
six  drachms  of  pulverized  alum,  stir  with  a  brush  to  quicken  the  solution  of  the  salt,  and 
let  tlie  whole  rest  20  minutes.     The  liquor,  which  has  a  fine  scarlet  color,  is  to  be  care- 
fully decanted  into  another  vessel,  and  there  is  to  be  put  into  it  the  wbites  of  two  eggl 
well  beat  up  with  half  a  pound  of  water.     Stir  again  with  a  brush.     The  copper  is  re- 
placed  on  the  fire,  the  alumina  becomes  concrete,  and  carries  down  the  coloring;  matter 
with  it.    The  copper  is  to  be  taken  from  the  fire,  and  left  at  rest  for  25  or  30  minutes  to 
allow  the  carmine  to  fall  down.    When  the  supernatant  liquor  is  drawn  off,  the  de- 
posite  is  placed  upon  filter  cloth  stretched  upon  a  frame  to  dram.    \\  hen  the  cannine 
hS  the  c'onsistence  of  cream  cheese,  it  is  taken  from  the  filter  with  a  silver  or  ivory 
knife  and  set  to  dry  upon  plates  covered  with  paper,  to  screen  it  from  dust.    A  pound  ol 
cochineal  gives  in  this  way  an  ounce  and  a  half  of  carmine.       ,      ^  ^      .        .,      r   •    . 
Process  of  Madame  Cene.tte,  of  Amsterdam^  with  salt  of  sorrel.— Into  six  pails  of  nyer 
water  boilinc'  hot  throw  two  pounds  of  the  finest  cochineal  in  powder,  continue  the 
ebullition  for'two  hours,  and  then  add  3  oz.  of  refined  saltpetre,  and  after  a  few  minutes 
4  oz  of  salt  of  sorrel.     In  ten  minutes  more  take  the  copper  from  the  fare  and  let  it 
settle  for  four  hours;  then  draw  off  the  liquor  with  a  syphon  into  flat  plates  and  leave  it 
there  for  three  weeks.     Afterwards  there  is  formed  upon  the  surface  a  pretty  thick  mouldi- 
ne«s  which  is  to  be  removed  dexterously  in  one  pellicle  by  a  slip  of  whalebone.    Should 
the  film  tear  and  fra-menls  of  it  fall  down,  they  must  be  removed  with  the  utmost  care. 
Decant  the  supernatant  water  with  a  syphon,  the  end  of  which  may  touch  the  bottom  of 
the  vessel  because  the  layer  of  carmine  is  very  firm.    Whatever  water  remains  must  be 
sucked  away  by  a  pipette.    The  carmine  is  dried  in  the  shade,  and  has  an  extraordinary 

^""'carmine  by  the  salt  of  tin,  or  the  Carmine  of  China.-Boi\  the  cochineal  in  ^iy^^  water, 
adding  some  Roman  alum,  then  pass  through  a  fine  cloth  to  remove  '^^J^'^^'^^^^^ 
set  Ihe  liquor  aside.  It  becomes  brighter  on  keeping.  After  having  I'^f  ^^^'^  J^^"^'' 
pour  into  it,  drop  by  drop,  solution  of  tin  till  the  carmine  be  precipitated.  The  propor- 
?ons  are  one  pailful  of  water,  20  oz.  of  cochineal,  and  60  grains  of  alum,  with  a  .ohi. 
aon  of  tin  containing  4  oz.  of  the  metal. 
Vol.  I.  3  C 


378 


CARPET. 


CARPET. 


879 


l\ 


IB!} 
Til 


;,M 


u 


To  revive  or  htghten  carmine.^We  may  brighten  ordinary  carmine,  and  obtain  a  very 
fine  and  clear  pigment,  by  dissolving  it  in  water  of  ammonia.  For  this  purpose  we  leave 
immonia  upon  carmine  in  the  heat  of  the  son,  till  all  its  color  be  extracted,  and  the  liquor 
has  got  a  fine  red  tinge.  It  must  be  then  drawn  off  and  precipitated,  by  acetic  acid  and 
alchohol,  next  washed  with  alcohol,  and  dried.  Carmine  dissolved  in  ammonia  has  blen 
long  employed  by  painters,  under  the  name  of  liquid  carmine. 

Carmine  is  the  finest  red  color  which  the  painter  possesses.  It  is  principally  employed 
m  miniature  painting,  water, colors,  and  to  tint  artificial  flowers,  because  it  is  more  trans- 
parent than  the  other  colors.     For  Carminiunif  see  Cochineal. 

This  valuable  pigment  is  often  adulterated  with  starch.  Water  of  ammonia  enables 
us  to  detect  this  fraud  by  dissolving  the  pure  carmine,  and  leaving  the  starchy  matter, 
as  well  as  most  other  sophisticating  substances.  Such  debased  carmine  is  apt  to  spoil 
with  damp. 

CARPET.  (Tapis,  Fr. ;  Teppich,  Germ.)  A  thick  woollen  fabric  of  variegated 
colors,  for  covering  the  floors  of  the  better  sort  of  apartments.  This  luxurious  manufac- 
ture took  its  origin  in  Persia  and  Turkey,  whence  the  most  beautiful  patterns  were  wont 
to  come  into  Europe;  but  they  have  been  for  some  time  surpassed  by  the  workmanship  of 
France,  Great  Britain,  and  Belgium.  To  form  a  just  conception  of  the  elegant  and  in- 
genious processes  by  which  carpets  are  made,  we  should  visit  the  royal  establishment  of 
the  Gobelins  at  Paris,  where  we  would  see  the  celebrated  carpet  manufactory  of  the 
Savounerie,  which  has  been  transported  thiiher.  A  detailed  set  of  engravings  of  this  art 
is  given  by  Roland  de  la  Platiere  in  the  first  and  second  volumes  of  the  Encyclopedi 
Methodique,  to  which  I  must  refer  my  readers,  as  a  due  exposition  c^  its  machines  anu 
operations  would  far  exceed  the  scope  of  the  present  volume. 

The  warp,  says  M.  Roland,  being  the  foundation  of  the  fabric,  ought  to  be  of  fine 
wool,  equally  but  firmly  spun,  and  consist  of  three  yarns  twisted  into  one  thread.  The 
yarns  that  are  to  form  the  velvety  surface  of  the  carpet,  ought  also  to  be  of  the  best 
quality,  but  soft  and  downy  in  their  texture,  so  that  the  dye  may  penetrate  every  fila- 
ment. Hemp,  or  linen  yarns,  are  likewise  employed  in  this  manufacture,  as  a  woof,  to 
bind  the  warp  firmly  together  after  each  shoot  of  the  velvety  threads.  Thus  we  see 
that  good  carpeting  consists  essentially  of  two  distinct  webs  woven  at  the  same  time, 
and  firmly  decussated  together  by  the  woof  threads.  Hence  the  form  of  the  pattern  is 
the  same  upon  the  two  sides  of  the  cloth,  only  the  colors  are  reversed,  so  that  what  was 
green  upon  one  side  becomes  red  or  black  upon  the  other,  and  vice  versa.  The  smaller 
the  figures  the  more  frequent  the  decussations  of  the  two  planes,  and  the  firmer  and 
more  durable  the  fabric. 

The  carpet  manufacture,  as  now  generally  practised,  may  be  distributed  into  two  sys- 
tems— that  of  double  fabrics,  and  that  cut  in  imitation  of  velvet.  Of  late  years  th« 
Jacquard  loom  has  been  much  used  in  weaving  carpets,  the  nature  of  which  will  b< 
found  fully  explained  under  that  title. 

For  the  sake  of  illustration,  if  we  suppose  the  double  carpets  to  be  composed  of  only 
two  colors,  the  principle  of  weaving  will  be  easily  understood ;  for  it  is  only  necessary 
to  raise  the  warp  of  each  web  alternately  for  the  passage  of  the  shuttle,  the  upper  well 
being  entirely  above  when  the  under  web  is  being  woven,  or  decussated,  and  vice  versa. 
In  a  Brussels  carpet  the  worsted  yam  raised  to  form  the  pile,  and  make  the  figure,  is 
not  cut;  in  the  Wilton  the  pile  is  cut  to  give  it  a  velvety  aspect  and  softness.  In  the 
imperial  Brussels  carpet  the  figure  is  raised  above  the  ground,  and  its  pile  is  cut, 
but  the  ground  is  uncut;  and  in  the  royal  Wilton,  the  pile  is  both  raised  higher 
than  in  the  common  Wilton,  and  it  is  cut,  wiicreby  it  has  a  rich  cushion-like  ap- 
pearance. The  cloth  of  all  these  superior  carpets  consists  of  woollen  and  linen,  or 
hemp  ;  the  latter  being  put  upon  a  beam,  and  brought,  of  course,  through  heddles  and  a 
reed ;  but  as  its  only  purpose  is  to  bind  together  the  worsted  fabric,  it  should  not  be 
visible  upon  the  upper  face  of  the  carpet.  The  worsted  yarn  is  wound  upon  small  bob- 
bins or  pirns,  with  a  weight  affixed  to  each,  for  giving  proper  tension  to  the  threads. 
Their  number  varies,  for  one  welf,  from  1300  to  1800,  according  as  the  carpet  is  to 
be  27  or  36  inches  wide ;  and  they  are  placed,  in  frames,  behind  the  loom,  filled  with 
differently  colored  yam,  to  correspond  with  the  figure.  This  worsted  warp  is  then  drawn 
through  the  harness,  heddles,  and  reed,  to  be  associated  with  the  linen  yarn  in  the  com- 
pound fabric. 

In  Kidderminster  carpeting,  both  warp  and  weft  appear  upon  the  face  of  the  cloth, 
whereas,  in  the  Brussels  style,  only  the  warp  is  seen,  its  binding  weft  being  fine  hempen 
or  linen  threads.  The  three-ply  imperial  carpet,  called  the  Scotch,  is  coming  very 
much  into  vogue,  and  is  reckoned  by  many  to  be  little  inferior  in  texture,  look,  and 
wear  to  the  Brussels.  Kilmarnock  has  acquired  merited  distinction  by  this  ingenious 
industry.  In  this  fabric,  as  well  as  in  the  two-ply  Kidderminster,  the  weft  predominates, 
and  displays  the  design  ;  but  in  the  French  carpets,  the  worsted  warp  of  the  web  shows 
the  figure.  Plain  "Venetian  carpets,  as  used  for  stairs  and  passages,  are  woven  in  simple 
looms,  provided  merely  with  the  common  heddles  and  reed.    The  warp  should  be  a 


substance  of  worsted  yarn,  so  heavy  as  to  cover  in  the  weft  completely  from  the  view. 
Figured  Venetian  carpets  are  woven  in  the  two-ply  Kidderminster  looms,  and  are 
provided  with  a  mechanism  to  raise  the  pattern  upon  the  worsted  warp.    The  weft  is  an 
alternate  shoot  of  worsted  and  linen  yarn,  and  must  be  concealed. 

The  following  figure  and  description  will  explain  the  construction  of  the  three-ply 
imperial  Scotch  and  two-ply  Kidderminster  carpet-loom,  which  is  merely  a  modification 
of  the  Jacquard  metier.    The  Brussels  carpet-loom,  on  the  contrary,  is  a  draw-toy  loom 

on  the  damask  plan,  and  requires  the 
weaver  to  have  an  assistant.     Fig.  337j 
A  A  A,  is  the  frame  of  the  loom,  con- 
sisting of  four  upright  posts,  with  caps 
and  cross  rails  to  bind  them   together. 
The  posts  are  about  six  feet  high,     c  r, 
the   cloth-beam,  is   a  wooden    cylinder, 
six  inches   or  thereby   in   diameter,  of 
sufficient  length   to   traverse    the  loom, 
with    iron    gudgeons    in    the    two  ends, 
which  work  in  bushes  in  the  side  frame. 
On  one  end  of  this  beam  is  a  ratchet 
wheel,  with   a  tcrth   to  keep   it  from 
turning  round  backvards  by  the  tension 
of  the  wtb.    D,  the  lay,  with  its  reed, 
its  under  and  upper  shell,  its  two  lateral 
rulers  or  swords,  and  rocking-tree  above. 
There  are  grooves    in  the  upper  and 
under  shell,  into  which  the  reed  is  fitted. 
E,  the  heddles,  or  harness,  with  a  double 
neck  attached  to  each  of  the  tower  or  card 
mechanisms  f  f,  of  the  Jacquard  loom. 

The  heddles  are  connected  and  work  with 

thetreddles  b  b,  by  means  of  cords,  as  shown  in  the  figure,     g  g  are  wooden  boxes  for 
the  cards,     h,  the  yarn  or  warp-beam. 

In  draw-looms  of  every  kind,  there  is  no  sinking  of  any  portion  of  the  warp,  as  m 
plain  cloth-weaving ;  but  the  plane  of  the  warp  is  placed  low,  and  the  threads  under 
which  the  shuttle  is  to  pass  are  raised,  while  all  the  rest  remains  stationary.  The 
harness  part  of  this  carpel-loom  is  moved  by  an  assistant  boy  or  girl,  who  thus  allows 
the  weft   to  be  properly  decussated,  while  the  weaver   attends   to  working   the  front 

mounting  or  heddles.     Fig.  338,  a  repre- 


338 


sents   the  frame  of  a  carpet  draw-loom; 
B    is   a   box   or  frame   of  pulleys,   over 
which  the  cords  of  the  harness  pass,  and 
are  then  made  fast  to  a  piece  of  wood, 
seen  at  e,  which  the  weavers  call  a  table. 
From  the  tail  of  the  harness  the  simples 
descend,  and   to   the   end  of  each  is  at- 
tached  a   small  handle   g,  called   a  bob. 
These   handles   being    disposed    in    pairs, 
and  their   regularity  preserved  by  means 
of  a  perforated  board  c,  it  is  merely  ne- 
cessary  to   pull  every  handle  in   succes- 
sion ;    the    weaver,    at    the   same    time, 
working  his  treddles  with  his  feet,  as   in 
any  other  loom.    The   treddles   are  four 
in  number,  the  fabric  being   that  of  plain  or  alternate  cloth,  and  two  treddles  allot- 
ted   for    each   web.    The   harness   part  of  the  carpet   draw-loom  is   furnished    with 
mails    or  metallic  eyes,  to  save  friction ;  two  thi^ids  being  drawn  through  each  eye. 
The  desit'n   or  pattern  of  a  carpet   is   drawn   upou    cross-rule  paper,  exactly  m  the 
same  way  as  every  other  kind  of  fancy-loom  work,  and  is  transferred  from  the  paper 
to  the  mounting  by  the  rules  for  damask  weaving.    Suppose  that  a  double  web  is  «> 
mounted  that  every  alternate  thread  of  the  one  may  be  raised,  so  as  to  form  a  suffi- 
cient shed-way  for  the  shuttle,  without  depressing  the  other  in  the  least.     Then  suppc^ 
another  web  placed  above  the  former,  at  such  a  distance  that  it  will  exactly  touch  the 
convexity  of  those  threads  of   the  former  which  are  raised.     Then,  if  the  threads  of 
the  latter  web  are  sunk  while   the   others  are  raised,  the   two  would  be  entirely  in- 
corporated.     But  if  this  be  only  partially  done,  that  is,  at  particular  places,  only  those 
parts    immediately  operated   upon  will   be   affected   by   the    action  of  the  apparatus. 
If  the  carpet  is  a  two-colored  pattern,  as  black  and  red,  and  if  upon  the  upper  sur- 

8C2 


380 


CARPET. 


ill: 


I  SB 


iJ 


If' 


face,  as  extended  in  the  loom,  red  flowers  are  to  be  represented  upon  a  black  ground, 
then  all  those  specie?  of  design  paper  which  are  colored  may  be  supposed  to  represent 
the  red,  and  those  which  are  vacant  the  black.  Then  counting  the  spaces  upon  the 
paper,  omit  those  which  are  vacant,  and  cord  those  which  are  colored,  and  the  effect 
will  be  produced.  But  as  the  two  webs  are  to  be  raised  alternately,  whatever  is  corded 
for  the  first  handle  must  be  passed  by  for  the  second,  and  vice  versa ;  so  that  the  one  will 
form  the  flower,  and  the  other  the  ground. 

The  board  by  which  the  simples  are  regulated  appears  at  F.    D  shows  the  weights. 

CARPET— Nkw  Patent.  Mr.  Simcox,  of  Kidderminster,  has  patented  an 
inventiou  for  an  improved  manufacture  of  carpets,  in  whicli,  by  dispensing  with  the 
Jacquard  loom,  as  well  as  the  iron  wires  and  tags  usually  employed  to  produce  terry 
fabrics,  such  as  Brussels  carpets  and  coach-lace,  he  can  work  his  machinery  at  greater 
speed  and  more  economically.  His  second  improvement  relates  to  the  manufacture  of 
fabrics  with  cut  pile,  such  as  Wilton  or  Axminster  carpets.  He  makes  a  ribbed  fabric, 
greatly  resembling  the  Brussels  carpet.,  by  a  combination  of  woollen  and  linen  warp  and 
weft,  arranged  in  such  a  manner  that  the  woollen  warp,  in  the  form  of  a  ribbed  surface, 
may  constitute  the  face  of  the  fabric,  while  the  linen  warp  forms  the  ground  or  back  of  tlie 
fabric.  The  plan  he  prefer^  as  most  resembling  the  Brussels,  consists  in  weaving  the 
fabric  as  nearly  as  possible  in  the  ordinary  way,  except  that,  instead  of  inserting  a  tag 
or  wire  to  form  the  rib  or  terry,  the  patentee  throws  in  a  thick  shoot  or  weft  of  woollen 
or  cotton,  over  which  the  woollen  warp  is  drawn,  and  forms  a  rib ;  the  woollen  warp 
being  afterwards  bound  down  with  a  linen  shoot  or  weft  in  the  ordinary  way.  The 
woollen  warp  employed  being  all  of  one  colour,  the  fabric  produced  will  be  plain  or 
unornamented,  with  a  looped  or  terry  pile ;  and  upon  this  fabric  any  design  may  be 
printed  from  blocks. 

The  looms  differ  from  the  former  chiefly  in  the  employment  of  two  separate  shuttles, 
one  for  the  woollen  and  one  for  the  linen  weft  These  shuttles  are  both  thrown  by  the 
same  pickers  and  the  same  picking-sticks,  and  consequently  the  shuttle  boxes  must  be 
moved  up  and  down  as  may  be  required,  in  order  to  allow  the  picker  to  throw  the 
proper  shuttle.  It  will  also  be  necessary  to  work  the  healds  in  a  suitable  manner  to 
form  the  proper  shreds,  in  order  that  the  woollen  face  may  be  properly  bound  to  the 
linen  ground. 

Figures  illustrating  the  construction  of  his  loom  are  given  by  the  patentee. 

The  second  part  of  his  invention  relates  to  the  production  of  fabrics  with  a  cut  pile, 
like  the  Axminster  or  Wilton  rugs  or  carpets.  The  ordinary  mode  of  making  some  of 
these  fabrics  is  to  weave  the  pattern  in  by  means  of  a  Jacquard  apparatus,  and  pass  the 
woollen  warp  over  a  rod  or  tag,  which  is  afterwards  cut  by  passing  a  suitable  knife 
along  it,  thereby  producing  the  cut  pile.  The  patentee  produces  the  design  and  surface 
of  the  fabric  from  the  weft  in  place  of  the  warp  as  heretofore.  For  this  purpose  the 
weft  is  made  to  consist  of  thick  woollen  shoots,  which  must  be  painted  or  stained  with 
suitable  colours,  precisely  as  the  woollen  warps  have  been  heretofore  done;  and  the 
woollen  shoot,  when  thrown  in,  is,  by  means  of  suitably  formed  hooks,  pulled  up  and 
turned  into  loops,  which,  when  they  are  properly  secured  to  the  foundation  or  ground 
of  the  fabric,  are  afterwards  cut  by  means  of  knives  or  cutting  instruments,  with  which 
the  hooks  are  furnished,  for  the  purpose  of  releasing  them  from  the  loops,  and  producing 
the  cut  pile.  The  patentee  observes,  that  cotton  and  other  cheap  materials  may  be  em- 
ployed with  great  advantage  in  the  production  of  some  of  these  fabrics. — NewtoiCs 
Journal,  xxxiv.  167. 

Another  invention  of  improvements  in  manufacturing  figured  fabrics,  princi- 
pally designed  for  the  production  of  carpeting,  patented  by  Mr.  James  Templeton,  of 
Glasgow,  consists  in  producing  the  pattern  either  on  one  or  both  sides  of  the  fabric,  by 
meal's  of  printed  weft ;  also  in  the  use  of  printed  parti-coloured  fur  or  weft,  in  the  manu- 
facture of  Axminster  carpet,  and  other  similar  fabrics.     This  invention  is  also  applicable 

to  the  production  of  figured  chenOle  weft  for  the  manufacture  of  chenille  shawls. 

Newtoris  Journal,  xxxvii.  148. 

Carpets,  Printed.  Mr.  Wood  has  taken  a  patent  for  weaving  and  printing  carpets, 
using  an  ordinary  Brussels  carpet  loom.  After  putting  in  the  wire,  or  otherwise 
forming  the  loop,  he  throws  in  the  usual  linen  shoot,  on  the  face,  to  bind  it;  and  then, 
for  the  back  shoot,  he  throws  in  a  thick  soft  weft.  Or,  to  make  a  better  edge  and  more 
elastic  back,  he  employs  the  ordinary  two  linen  shoots, — one  on  the  face  and  the  other 
in  the  back, — and  then  (or  before  throwing  in  the  second  linen  shoot)  he  draws  down 
only  one-half  of  the  lower  portion  of  the  linen  warp  (being  one-quarter  of  the  whole), 
and  throws  in  the  thick  shoot,  which  is  driven  up  by  the  batten  or  lay,  so  as  to  cover  the 
second  linen  shoot,  which  is  then  inside  the  fabric :  from  the  thick  shoot  being  bound 
only  by  each  alternate  yarn  of  the  warp,  it  will  be  more  elastic  than  if  bound  more 
closely  by  using  every  yarn ;  whilst  the  second  linen  shoot,  having  half  the  warp  over 
it,  holds  down  the  face  or  first  shoot ;  and  any  inequality  in  the  taking  up  of  the  linn 


CARTHAMUS. 


381 


warp,  by  one  portion  of  it  binding  in  a  ^cater  substance  than  the  other,  is  remedied 
by  drawing  down  the  different  portions  in  succession. 

In  printing  Brussels  and  other  pile  carpets,  the  patentee  first  provides  a  table,  long 
enough  to  receive  the  entire  length  or  piece  of  the  carpet  to  be  printed ;  at  each  end  of 
the  table  there  is  a  frame  of  the  same  height  or  level,  sufficiently  long  to  receive  the 
cylinder  printing  machine  when  off  the  fabric ;  and  on  the  surface  of  the  table  the 
printing  blanket  is  laid  between  two  rails  or  guides,  which  are  fixed  at  exactly  the  saine 
distance  apart  as  the  carpet  is  wide,  so  as  to  keep  it  in  one  position,  iind  to  form  the 
guides  for  the  printing  cylinders.  The  carpet  is  fastened  to  one  end  of  the  table,  and 
w  then  laid  on  the  top  of  the  same,  and  drawn  tight  at  the  other  end  by  a  roller,  which 
is  furnished  with  a  ratchet  wheel  and  click.  Tlie  printing  cylinders  are  mounted  in  a 
movable  frame,  containing  a  corresponding  number  of  colour  cans  and  feeding  rollers, 
to  supply  them  with  colour.  This  printing  apparatus  is  passed  over  the  table,  and 
between  the  guide  rails  (the  patterns  on  the  cylinder  being  coloured,  and  bearing  upon 
the  carpetX  to  the  frame  at  the  other  end  of  the  table,  and  then  back  again ;  and  this 
process  is  repeated  until  the  fabric  is  sufiiciently  coloured.  In  order  to  insure  each 
part  of  the  pattern  or  printing  surface  coming  again  and  again  on  the  same  place, 
toothed  wheels  are  affixed  on  the  axis  of  the  printing  cylinders,  which  geer  into  racks 
fixed  on  the  sides  of  the  table;  so  that,  however  frequently  the  printing  apparatus 
passes  over  the  fabric,  every  part  of  the  pattern  will  fall  on  the  same  place.  Instead 
of  the  printing  apparatus  being  passed  back  again  over  same  table,  it  may,  by  the  appli- 
cation of  movable  frames  at  the  end  of  the  table,  be  moved  sideways  on  to  another 
table,  and  so  successively. — Newtm's  Journal, -sxsiw.  2bQ. 

CARTHAMUS,  or  safflower  (carthamus  tinctorius),  (Carihame,  Fr. ;  F  rher  dtsiel. 
Germ.),  the  flower  of  which  alone  is  used  in  dyeing,  is  an  annual  plant  cultivated  m 
Spain  Egypt,  and  the  Levant.  There  are  two  varieties  of  it  —  one  which  has  large 
leaves,  and  the  other  smaller  ones.  It  is  the  last  which  is  cultivated  in  Egypt,  where  it 
forms  a  considerable  article  of  commerce.  j      rrv    «    ♦ 

Carthamus  contains  two  coloring  matters,  one  yeUow  and  the  other  red.  Ihe  tirst 
alone  is  soluble  in  water ;  its  solution  is  always  turbid :  with  re-agents  it  exhibits  the 
characters  usually  remarked  in  yellow  coloring  matters.  The  acids  render  it  lighter, 
the  alkalis  deepen  it,  giving  it  more  of  an  orange  hue  :  both  produce  a  «anall  dun  pre- 
cipitate, in  consequence  of  which  it  becomes  clearer.  Alum  forms  a  precipitate  of  a  deep 
yellow,  in  small  quantity.  The  solution  of  tin  and  the  other  metallic  solutions  cause  pre- 
cipitates which  have  nothing  remarkable  in  them. 

The  yellow  mailer  of  carthamus  is  not  employed ;  but  in  order  to  extract  this  portion, 
the  carthamus  is  put  into  a  bag,  which  is  trodden  under  water,  till  no  more  color  can 
be  pressed  out.    The  flowers,  which  were  yellow,  become  reddish,  and  lose  m  this  opera 
tion  nearly  one  half  of  their  w«ight.     In  this  state  they  are  used. 

For  extracting  the  red  part  of  carthamus,  and  thereafter  applying  it  to  stuff,  the  prop- 
erty which  alkalis  possess  of  dissolving  it  is  had  recourse  to,  and  it  is  afterwards  pre- 
cipitated by  an  acid.  „        .  .       ,        ,    •  ,.     v 

The  process  of  dyeing  consists,  therefore,  m  extracting  the  coloring  matter  by  means  oi 
an  alkali,  and  precipitating  it  on  the  stuff  by  means  of  an  acid.  It  is  this  fecula  which 
serves  for  making  the  rouge  employed  by  ladies. 

As  to  this  rouge,  the  solution  of  carthamus  is  prepared  with  crystallized  carbonate  or 
soda,  and  it  is  p?ecipitaled  by  lemon  juice.  It  has  been  remarked  that  lemons,  begin- 
ning to  spoil,  were  filler  for  this  operation  than  those  which  were  less  ripe,  whose  juice 
retained  much  mucilage.  After  squeezing  out  the  lemon  juice,  it  is  left  to  settle  for  some 
days.  The  precipitate  of  carthamus  is  dried  at  a  gentle  heat  upon  plates  of  stone-ware  ; 
from*  which  it  is  detached  and  very  carefully  ground  with  talc,  which  has  teen  reduced 
tO  a  very  subtile  powder,  by  means  of  the  leaves  of  shave-grass  (presle),  and  successively 
passed  through  sieves  of  increasing  fineness.  It  is  the  fineness  of  Ihe  talc,  and  the  greater 
or  less  proportion  which  it  bears  to  the  carthamus  precipitate,  which  constitute  the  dif- 
ference between  the  high  and  low  priced  rouges. 

Carthamus  is  used  for  dyeing  silk,  poppy,  nacarat  (a  bright  orange-red),  cherry,  rose 
color  and  flesh  color.  The  process  differs  according  to  the  intensity  of  the  color,  and 
the  greater  or  less  tendency  to  flame  color  that  is  wanted.  But  the  carthamus  bath, 
whose  application  may  be  varied,  is  prepared  as  follows :  ,       ^     ,        i 

The  carthamus,  from  which  the  yellow  mailer  has  been  extracted,  and  wliose  lumps 
have  been  broken  down,  is  put  into  a  trough.  It  is  repeatedly  sprinkled  with  cendres 
'  pravelees  (crude  pearlashes),  or  soda  (barilla)  well  powdered  and  sifted  at  the  rate  of 
6  pounds  for  120  lbs.  of  carthamus;  but  soda  is  preferred,  mixing  carefully  as  the  alkaU 
is  introduced.  This  operation  is  caUed  amesher.  The  amestred  carthamus  is  put  into 
a  small  trough  with  a  grated  bottom,  first  lining  this  trough  with  a  closely  woven  cloth. 
"When  it  is  about  half  filled,  it  is  placed  over  the  large  trough,  and  cold  water  is  poured 
into  the  upper  one,  till  ihe  lower  becomes  full.     The  carthamus  is  then  set  over  another 


382 


CASE-HARDENING. 


'.\\ 


trongh,  till  the  water  comes  from  it  almost  colorless.  A  little  more  alkali  is  now  mixed! 
with  It,  and  fresh  water  is  passed  through  it.  These  operations  are  repeated  till  the  car- 
thamus  be  exhausted,  when  it  turns  yellow. 

After  distributing  the  silk  in  hanks  upon  the  rods,  lemon  juice,  brought  in  casks  from 
Provence,  is  poured  into  the  bath  till  it  becomes  of  a  fine  cherry  color;  this  is  called 
turning  the  bath  (virer  le  bain).  It  is  well  stirred,  and  the  silk  is  immersed  and  turned 
round  the  skein-sticks  in  the  bath,  as  long  as  it  is  perceived  to  take  up  the  color.  For 
ponceau  (poppy  color),  it  is  withdrawn,  the  liquor  is  run  out  of  it  upon  the  peg,  and  it 
is  turned  through  a  new  bath,  where  it  is  treated  as  in  the  first.  Aflei  this  it  is  dried 
and  passed  through  fresh  baths,  continuing  to  wash  and  dry  it  between  each  operation, 
till  it  has  acquired  the  depth  of  color  that  is  desired.  When  it  has  reached  the  proper 
pomt,  a  brightening  is  given  it  by  turning  it  round  the  sticks  seven  or  eight  times  in  a  bath 
of  hot  water,  to  which  about  half  a  pint  of  lemon  juice  for  each  pailful  of  water  has  been 
added. 

When  silk  is  to  be  dyed  ponceau  or  flame  color,  it  must  be  previously  boiled  as  for 
white ;  it  must  then  receive  a  slight  foundation  of  annotto,  as  explained  in  treating  of 
this  substance.    The  silk  should  not  be  alumed. 

The  nacaratsy  and  the  deep  cherry  colors,  are  given  precisely  like  the  ponceauxy  only 
they  receive  no  annotto  ground ;  and  baths  may  be  employed  wh'ch  have  served  for  the 
ponceauy  so  as  to  complete  their  exhaustion.  Fresh  baths  are  not  made  for  the  latter 
colors,  unless  there  be  no  occasion  for  the  poppy. 

With  regard  to  the  lighter  cherry-reds,  rose  color  of  all  shades  and  flesh  colors,  they 
are  made  with  the  second  and  last  runnings  of  the  carthamus,  which  are  weaker.  The 
deepest  shades  are  passed  through  first. 

The  lightest  of  all  these  shades,  which  is  an  extremely  delicate  flesh  color,  requires  a 
little  soap  to  be  put  into  the  bath.  This  soap  lightens  the  color,  and  prevents  it  from 
taking  too  speedily,  and  becoming  uneven.  The  silk  is  then  washed,  and  a  little  bright- 
ening is  given  it,  in  a  bath  which  has  served  for  the  deeper  colors 

All  these  baths  are  employed  the  moment  they  are  made,  or  as  speedily  as  possible, 
because  they  lose  much  of  their  color  upon  keeping,  by  which  they  are  even  entirely 
destroyed  at  the  end  of  a  certain  time.  They  are,  moreover,  used  cold,  to  prevent  the 
color  from  being  injured.  It  must  have  been  remarked  in  the  experiments  just  described, 
that  the  caustic  alkalis  attack  the  extremely  delicate  color  of  carthamus,  making  it  pass 
to  yellow.  This  is  the  reason  why  crystals  of  soda  are  preferretf  to  the  other  alka- 
line matters. 

In  order  to  diminish  the  expense  of  the  carthamus,  it  is  the  practice  in  preparing  the 
deeper  shades  to  mingle  with  the  first  and  the  second  bath  about  one  fifth  of  the  bath  of 
archil. 

Dobereiner  regards  the  red  coloring  matter  of  carthamus  as  an  acid,  and  the  yellow  as 
a  base.  His  carlhamic  acid  forms,  with  the  alkalis,  colorless  salts,  decomposed  by  the 
tartaric  and  acetic  acids,  which  precipitate  the  acid  of  a  bright  rose-red.  Heat  has  a  re- 
markable influence  upon  carthamus,  rendering  its  red  color  yellow  and  dull.  Hence,  the 
colder  the  water  is  by  which  it  is  extracted,  the  finer  is  the  color.  Light  destroys  the 
color  very  rapidly,  and  hitherto  no  means  have  been  found  of  counteracting  this 
efiect.  For  this  reason  this  brilliant  color  must  be  dried  in  the  shade,  its  dye  must  be 
given  in  a  shady  place,  and  the  silk  stufls  dyed  with  it  must  be  preserved  as  much  as 
possible  from  the  light.  Age  is  nearly  as  injurious  as  light,  especially  upon  the  dye  in  a 
damp  state.  The  color  is  very  dear,  because  a  thousand  parts  of  carthamus  contain  only 
five  of  it. 

In  preparing  the  finest  rouge,  the  yellow  coloring  matter  being  separated  by  washing 
with  water,  the  red  is  then  dissolved  by  the  aid  of  alkali,  and  is  thrown  down  on  linen 
or  cotton  rags  by  saturating  the  solution  with  vegetable  acid.  The  color  is  rinsed  out  of 
^ese  rags,  dissolved  anew  in  alkalis,  and  once  more  precipitated  by  lemon  juice.  The 
oest  and  freshest  carthamus  must  be  selected.  It  is  put  into  linen  bags,  which  are  placed 
in  a  stream  of  water,  and  kneaded  till  the  water  runs  off  colorless.  The  bags  are  then 
put  into  water  soured  with  a  little  vinegar,  kneaded  till  the  color  is  all  expelled,  and 
finally  rinsed  in  running  water.  By  this  treatment  the  carthamus  loses  nearly  half  its 
weight.  6633  cwts.  of  safflower  were  imported  into  the  United  Kingdom  in  1835,  of 
which  2930  cwts.  were  retained  for  internal  consumption. 

CASE-HARDENING  is  the  name  of  the  process  by  which  iron  tools,  keys,  &c.,  have 
their  surfaces  converted  into  steel. 

Steel  when  very  hard  is  brittle,  and  iron  alone  is  for  many  purposes,  as  for  fine  keys, 
far  too  soft.  It  is  therefore  an  important  desideratum  to  combine  the  hardness  of  a 
steely  surface  with  the  toughness  of  an  iron  body.  These  requisites  are  united  by  the 
process  of  case-hardening,  which  does  not  differ  from  the  making  of  steel,  except  in  the 
shorter  duration  of  the  process.  Tools,  utensils,  or  ornaments,  intended  to  be  polished, 
are  first  manufactured  in  iron  and  nearly  finished,  after  which  they  are  put  into  an  iron 


'  m 


CASHMERE. 


383 


box,  together  with  vegetable  or  animal  charcoal  in  powder,  and  cemented  for  a  certain 
time.  This  treatment  converts  the  external  part  into  a  coating  of  steel,  which  is  usually 
very  thin,  because  the  time  allowed  for  the  cementation  is  much  shorter  than  when  the 
whole  substance  is  intended  to  be  converted.  Immersion  of  the  heated  pieces  into  water 
hardens  the  surface,  which  is  afterwards  polished  by  the  usual  methods.  Moxon,  in  his 
Mechanic  Exercises,  p.  56,  gives  the  following  receipt  for  case-hardening :— "  Cow's  horn 
or  hoof  is  to  be  baked  or  thoroughly  dried  and  pulverized.  To  this  add  an  equal 
quantity  of  bay  salt ;  mix  them  with  stale  chamber-ley  or  white  wine  vinegar :  cover 
the  iron  with  this  mixture, and  bed  it  with  the  same  in  loam,  or  enclose  it  in  an  iron  box; 
lay  it  on  the  hearth  of  the  forge  to  dry  and  harden  :  then  put  it  into  the  fire,  and  blow 
till  the  lump  have  a  blood-red  heat,  and  no  higher,  lest  the  mixture  be  burnt  too  much. 
Take  the  iron  out,  and  immerse  it  in  water  to  harden."    I  consider  the  vinegar  to  be 

quite  superfluous.  v  4    «i>' 

I  shall  now  describe  the  recent  application  of  prussiate  (ferrocyanate)  of  potash  to  tnis 
purpose.  The  piece  of  iron,  after  being  polished,  is  to  be  made  brightly  red-hot,  and 
then  rubbed  or  sprinkled  over  with  the  above  salt  in  fine  powder,  upon  the  part  intended 
to  be  hardened.  The  prussiate  being  decomposed,  and  apparently  dissipated,  the  iron  if 
to  be  quenched  in  cold  water.  If  the  process  has  been  well  managed,  the  surface  of  the 
metal  will  have  become  so  hard  as  to  resist  the  file.  Others  propose  to  smear  over 
the  surface  of  the  iron  with  loam  made  into  a  thin  paste  with  a  strong  solution  of 
the  prussiate,  to  dry  it  slowly,  then  expose  the  whole  to  a  nearly  white  heat,  and 
finally  plunge  the  iron  into  cold  water,  when  the  heat  has  fallen  to  dull  redness.    See 

CASHMERE  or  CACHEMERE,  a  peculiar  textile  fabric  first  imported  from  the 
kingdom  of  Cashmere,  and  now  well  imitated  in  France  and  Great  Britain.  The 
maferial  of  the  Cashmere  shawls  is  the  downy  wool  found  about  the  roots  of  the  hair  of 
the  Thibet  goat.  The  year  1819  is  remarkable  in  the  history  of  French  husbandry  for 
the  acquisition  of  this  breed  of  goats,  imported  from  the  East  under  the  auspices  of  their 
government,  by  the  indefalisable  courage  and  zeal  of  M.  Jaubert,  who  encountered  every 
fatigue  and  danger  to  enrich  his  country  with  these  va?aable  animals,  aided  by  the 
patriotism  of  M.  Ternaux,  who  first  planned  this  importation,  and  furnished  funds  for 
executin«»  it  at  his  own  expense  and  responsibility.  He  placed  a  portion  of  the  flock 
brought  by  M.  Jaubert,  at  his  villa  of  Saint  Ouen,  near  Paris,  where  the  climate  seemed 
to  be'' very  favorable  to  ihem,  since  for  several  successive  years  after  theur  introduction 
M.  Ternaux  was  enabled  to  sell  a  great  number  of  both  male  and  female  goals.  The 
quantity  of  fine  fleece  or  down  aflforded  by  each  animal  annually,  is  from  a  pound  and  a 

half  to  two  pounds.  «  «  ,  •    ,    r       J    «v 

The  wool  imported  into  Europe  comes  by  the  way  of  Casan,  the  capital  ol  a  gdvem- 
ment  of  the  Russian  empire  upon  the  eastern  bank  of  the  Wolga;  it  has  naturally  a 
grayish  color,  but  is  easily  bleached.  Its  price  a  few  years  back  at  Paris  was  17  francs 
per  kilogramme ;  that  is,  about  6  shillings  the  pound  avoirdupois.  The  waste  in  picking, 
carding,''and  spinning,  amounts  to  about  one  third  of  its  weight. 

The  mills  for  spinning  Cachemere  wool  have  multiplied  very  much  of  late  years  m 
France  as  appears  from  the  premiums  distributed  at  the  exposition  of  1834,  and  the 
prices  of  the  yarn  have  fallen  from  25  to  30  per  cent,  notwithstanding  their  improved 
fineness  and  quality.  There  is  a  fabric  made  with  a  mixture  of  Cachemere  down  and 
spun  silk  which  is  becoming  very  general.  One  of  the  manufacturers,  M.  Hmdenlang, 
exhibited  samples  of  Cachemere  cloth  woven  with  yarn  so  fine  as  No.  130  for  warp,  and 

No.  228  for  weft.  ,  ^  ^    ^  ■  r   ^ 

Messrs.  Pollino,  brothers,  of  Paris,  produced  an  assortment  of  Cachemere  pieces  Irom 
22  to  100  francs  the  yard,  dyed  of  every  fancy  shade.  Their  establishment  at  Ferte-Ber- 
nard  occupies  700  operatives,  with  an  hydraulic  wheel  of  60  horse  power. 

The  oriental  Cashmere  shawls  are  woven  by  processes  extremely  slow  and  consequently 
costly  whence  their  prices  are  very  high.  They  are  still  sold  in  Paris  at  from  4,000  to 
10  000  francs  a  piece ;  and  from  100  to  400  pounds  sterling  in  London.  It  became 
necessary,  therefore,  either  to  rest  satisfied  with  work  which  should  have  merely  a  surface 
appearance  or  contrive  economical  methods  of  weaving,  to  produce  the  real  Cachemere 
style  with  inuch  less  labor.  By  the  aid  of  the  draw-loom,  and  still  better  of  the  Jacquard 
loom  M.  Ternaux  first  succeeded  in  weaving  Cachemere  shawls  perfectly  similar  to  the 
oriental  in  external  aspect,  which  became  fashionable  under  the  name  of  French  Cache- 
mere.  But  to  construct  shawls  altos;ether  identical  on  both  sides  with  the  eastern,  was 
a  more  diflicult  task,  which  was  accomplished  only  at  a  later  period  by  M.  Bauson  of 

In  both  modes  of  manufacture,  the  piece  is  mounted  by  reeding-in  the  warp  for  the 
different  leaves  of  the  heddles,  as  is  commonly  practised  for  warps  in  the  Jacquard  looms. 
The  weaving  of  imitation  shawls  is  executed,  as  usual,  by  as  many  shuttles  »«  there  are 
colors  in  the  design,  and  which  are  thrown  across  the  warp  in  the  order  eslablisheci  by 


384 


CASK. 


CASSAVA. 


385 


'/mi 


the  neder.  The  greater  numbei  of  these  weft  yams  being  introduced  only  at  intervals 
into  the  web,  when  the  composition  of  the  pattern  requires  it,  they  remain  floating  loose 
at  the  back  of  the  piece,  and  are  cut  afterwards,  without  affecting  in  the  least  the  quality 
of  the  texture ;  but  there  is  a  considerable  waste  of  stuff  in  the  weaving,  which  is  worked 

up  into  carpets. 

The  weaving  of  the  imitation  of  real  Cachemere  shawls  is  different  from  the  above. 
The  yarns  intended  to  form  the  weft  are  not  only  equal  in  number  to  that  of  the  colors 
of  the  pattern  to  be  imitated,  but  besides  this,  as  many  little  shuttles  or  pirns  (like  those 
used  by  embroiderers)  are  filled  with  these  yarns,  as  there  are  to  be  colors  repeated  in 
the  breadth  of  the  piece ;  which  renders  their  number  considerable  when  the  pattern  is 
somewhat  complicated  and  loaded  with  colors.  Each  of  these  small  bobbins  or  shuttles 
passes  throuirh  only  that  portion  of  the  flower  in  which  the  color  of  its  yarn  is  to  appear, 
and  Slops  at  the  one  side  and  the  other  of  the  cloth  exactly  at  its  limit ;  it  then  returns 
upon  itself  after  having  crossed  the  thread  of  the  adjoinins  shuttle.  From  this  recipro- 
cal intertexture  of  all  the  yarns  of  the  shuttles,  it  results,  that  although  the  weft  is 
composed  of  a  great  many  different  threads,  they  no  less  constitute  a  continuous  line  in 
the  whole  breadth  of  the  web,  upon  which  the  lay  or  batteu  acts  in  the  ordinary  way 
We  see,  therefore,  that  the  whole  art  of  manufacturing  this  Cachemere  cloth  consists  in 
avoiding  the  confusion  of  the  shuttles,  and  in  not  striking  up  the  lay  till  all  have  fulfilled 
their  function.  The  labor  does  not  exceed  the  strength  of  a  woman,  even  though  she  has 
to  direct  the  loom  and  work  the  treddles.  Seated  on  her  bench  at  the  end  opposite  to 
the  middle  of  the  beam,  she  has  for  aids  in  weaving  shawls  from  45  to  52  inches  wide, 
two  girl  apprentices,  whom  she  directs  and  instructs  in  their  tasks.  About  four  hundred 
days  of  work  are  required  for  a  Cachemere  shawl  of  that  breadth.  For  the  construction 
of  the  loom,  see  Jacquard. 

In  the  oriental  process,  all  the  figures  in  relief  are  made  simply  with  a  slender  pirn 
without  the  shuttle  used  in  European  weaving.  By  the  Indians  the  flower  and  its 
ground  are  made  with  the  pirn,  by  means  of  an  intertwisting,  which  renders  them  in 
some  measure  independent  of  the  warp.  In  the  Lyons  imitation  of  this  style,  the  leaves 
of  the  heddles  lift  the  yarns  of  the  warp,  the  needles  embroider  as  in  lappet  weaving, 
and  the  flower  is  united  to  the  warp  by  the  weft  thrown  across  the  piece.  Thus  a  great 
deal  of  labor  is  saved,  the  eye  is  pleased  with  an  illusion  of  the  loom,  and  the  shawls  cost 
little  more  than  those  made  by  the  common  fly  shuttle. 

Considered  in  reference  to  their  materials,  the  French  shawls  present  three  distinct 
classes,  which  characterize  the  three  fabrics  of  Paris,  Lyons,  and  Nimes. 

Paris  manufactures  the  French  Cachemere,  properly  so  called,  of  which  both  th*  warp 
and  the  weft  are  the  yarn  of  pure  Cachemere  down.  This  web  represents  with  fidelity 
the  figures  ami  the  shades  of  color  of  the  Indian  shawl,  which  it  copies ;  the  dectption 
would  be  complete  if  the  reverse  of  the  piece  did  not  show  the  cut  ends.  The  Hindoo 
shawl,  also  woven  at  Paris,  has  its  warp  in  spun  silk,  which  reduces  its  price  without 
impairing  its  beauty  much. 

LyonsJ  however,  has  made  the  greatest  progress  in  the  manufacture  of  shawls.  It  ex- 
cels particularly  in  the  texture  of  its  Thibet  shawls,  the  weft  of  which  is  yarn  spun  with 
a  mixture  of  wool  and  spun  silk.  . ,    «, 

Nimes  is  remarkable  for  the  low  price  of  its  shawls,  in  which  spun  silk,  Thibet  down, 
and  cotton,  are  all  worked  up  together. 

The  value  of  shawls  exported  from  France  in  the  following  years  was— 


1831. 

1832. 

1833. 

Woollen   ------ 

Cachemere  down  -  - 
Spun  silk 

Frnncs. 

1,863,147 
433,410 
401,856 

Francs. 
2,070,926 
655,200 
351,152 

Francs. 
4,319,601 
609,900 

408,824 

I 


1  ii 


It  appears  that  M.  J.  Girard  at  Sevres,  near  Paris,  has  succeeded  best  m  producing 
Cachemere  shawls  equal  in  stuff  and  style  of  work  to  the  oriental,  and  tt  a  lower  price. 
They  have  this  advantage  over  the  Indian  shawls,  that  they  are  woven  without  seams,  in 
a  single  piece,  and  exhibit  all  the  variety  and  the  raised  effect  of  the  eastern  colors. 
Women  and  children  alone  are  employed  in  his  factor^'. 

CASK  (Tonneau,  Fr. ;  Fass,  Germ.),  manufacture  of  by  mechanical  power.  Mr. 
Samuel  Brown  obtained  a  patent  in  November,  1825,  for  certain  improvements  in 
machinery  for  making  casks,  which  seems  to  be  ingenious  and  worthy  of  record.  His 
mechanism  consists  in  the  first  place  of  a  circular  saw  attached  to  a  bench,  with  a  sliding 
rest  upon  which  rest  each  piece  of  wood  intended  to  form  a  stave  of  a  cask  is  fixed ;. 
and'  the  rest  being  then  slidden  forward  in  a  curved  direction,  by  the  assistance  of  an 
adjustable  guide,  brings  the  piece  of  wood  against  the  edge  of  the  rotatory  saw,  and  causes 
it  to  be  cut  into  the  curved  shape  required  for  the  edge  of  the  stave.  The  second  feature 
is  an  apparatus  with  cutters  attached  to  a  standard,  and  traversing  round  with  their 


earner  upon  a  centre,  by  means  of  which  the  upper  and  lower  edges  of  the  cask  are  cut 
round  and  grooved,  called  chining,  for  the  purpose  of  receiving  the  heads.  Thirdly,  an 
apparatus  not  very  dissimilar  to  the  last,  by  which  the  straight  pieces  of  wood  designed 
for  the  heads  of  the  cask  are  held  together,  and  cut  to  the  circular  figiire  required,  and 
also  the  bevelled  edges  produced.  And  fourthly,  a  machine  in  which  the  cask  is 
made  to  revolve  upon  an  axis,  and  a  cutting  tool  to  traverse  for  the  purpose  of  shaving 
the  external  part  of  the  cask,  and  bringing  it  to  a  smooth  surface.  .  .    ..    • 

The  pieces  of  wood  intended  to  form  the  staves  of  the  cask,  having  been  cut  to  their 
required  length  and  breadth,  are  placed  upon  the  slide-rest  of  the  first  mentioned  machine, 
and  confined  by  cramps ;  and  the  guide,  which  is  a  flexible  bar,  having  been  previoiMly 
bent  to  the  intended  curve  of  the  stave  and  fixe<}  in  that  form,  the  rest  is  then  slidden 
forward  upon  the  bench  by  the  hand  of  the  workman,  which  as  it  advances  (moving 
in  a  curved  direction)  brings  the  piece  of  wood  against  the  edge  of  the  revolving 
circular  saw,  by  which  it  is  cut  to  the  curved  shape  desired. 

The  guide  is  a  long  bar  held  by  a  series  of  movable  blocks  fitted  to  the  bench  by 
screws,  and  is  bent  to  any  desired  curve  by  shifting  the  screws :  the  edge  of  the  slide-rests 
which  holds  the  piece  of  wood  about  to  be  cut,  runs  against  the  long  guide  bar,  and  of 
consequence  is  conducted  in  a  corresponding  curved  course.  The  circular  saw  receive* 
a  rapid  rotatory  motion  by  means  of  a  band  or  rigger  from  any  first  mover ;  and  the  piece 
of  wood  may  be  shifted  laterally  by  means  of  racks  and  pinions  on  the  side-rest,  by  the 
workman  turning  a  handle,  which  is  occasionally  necessary  in  order  to  bring  the  piece 
of  wood  up  to,  or  away  from,  the  saw.  ,  ,     ,  ,  .  j     -.v 

The  necessary  number  of  staves  being  provided,  they  are  then  set  round  within  a 
confining  hoop  at  bottom,  and  brought  into  the  form  of  a  cask  in  the  usual  way,  and 
braced  by  temporary  hoops.  The  barrel  part  of  the  cask  being  thus  prepared,  in  order 
to  effect  the  chining,  it  is  placed  in  a  frame  upon  a  platform,  which  is  raised  up  by  a 
treddle  lever,  that  the  end  of  the  barrel  may  meet  the  cutters  in  a  sort  of  lathe  above  :  the 
cutters  are  then  made  to  traverse  round  within  the  head  of  the  barrel,  and,  as  they  pro- 
ceed, occasionally  to  expand,  by  which  means  the  bevels  and  grooves  are  cui  on  the 
upper  edge  of  the  barrel,  which  is  caUed  chiAing.  The  barrel  being  now  reversed,  the 
same  apparatus  is  brought  to  act  against  the  other  end,  which  becomes  chined  in  like 

manner.  ,         »    ♦     •  v* 

The  pieces  of  wood  intended  to  form  the  heads  of  the  cask  are  now  to  be  cut  straight 
by  a  circular  saw  in  a  machine,  similar  to  the  first  described  ;  but  in  the  present  instance 
the  slide-rest  is  to  move  forward  in  a  straisht  course.  After  their  straight  edges  are 
thus  produced,  they  are  to  be  placed  side  by  side,  and  confined,  when  a  scribing  cutter 
is  made  to  traverse  round,  and  cut  the  pieces  collectively  into  the  circular  form  desired 

for  heading  the  cask.  .   .    .      ,       ... 

The  cask  having  now  been  made  up,  and  headed  by  hand  as  usual,  it  is  p*ace(l  between 
centres  or  upon  an  axle  in  a  machine,  and  turned  round  by  a  rigger  or  band  with  a 
shaving  cutter,  sliding  along  a  bar  above  it,  which  cutter,  being  made  to  advance  and 
recede  as  it  slides  along,  shaves  the  outer  part  of  the  cask  to  a  smooth  surface. 

CASSAVA.  Cassava  bread,  coiiaque,  ^-c,  are  different  names  given  to  the  starch 
of  the  root  of  the  Manioc  {Jatropha  Manihot,  Linn.),  prepared  in  the  following  manuer 
in  the  West  Indies,  the  tropical  regions  of  America,  and  upon  the  African  coast.  The 
tree  belongs  to  the  natural  family  of  the  euphorbiacea. 

The  roots  are  washed,  and  reduced  to  a  pulp  by  means  of  a  rasp  or  grater.  The  pulp 
is  put  into  coarse  strong  canvass  bags,  and  thus  submitted  to  the  action  of  a  powerful 
press  by  which  it  parts  with  most  of  its  noxious  juice  (used  by  the  Indians  for  poisoning 
the  barbs  of  their  arrows.)  As  the  active  principle  of  this  juice  is  volatile,  it  is  easily 
dissipated  by  bakin?  the  squeezed  cakes  of  pulp  upon  a  plate  of  hot  iron.  Fifty  pounds 
of  the  fresh  juice,  when  distilled,  afford,  at  first,  three  ounces  of  a  poisonous  water,  pos- 
sessing an  intolerably  ofiensive  smell;  of  which,  35  drops  bemg  administered  to  a  slave 
convicted  of  the  crime  of  poisoning,  caused  his  death  in  the  course  of  six  minutes,  amid 

horrible  convulsions.*  .  ,.  v  v 

The  pulp  dried  in  the  manner  above  described  concretes  into  lumps,  which  become 
hard  and  friable  as  they  cool.  They  are  then  broken  into  pieces,  and  laid  out  in  the  sun 
to  dry  In  this  state  they  afford  a  wholesome  nutriment,  and  are  habitually  used  as  such 
by  the  negroes,  as  also  by  many  white  people.  These  cakes  constitute  the  only  pro- 
visions laid  in  by  the  natives,  in  their  voyages  upon  the  Amazons.  Boiled  in  water  with 
a  little  beef  or  mutton  they  form  a  kind  of  soup  similar  to  that  of  rice. 

The  cassava  cakes  sent  to  Europe  (which  I  have  eaten  with  pleasure)  are  composed 
almost  entirely  of  starch,  along  with  a  few  fibres  of  the  ligneous  matter.  It  may  be 
purified  by  diffusion  through  warm  water,  passing  the  milky  mixture  through  a  linen 
doth,  evaporating  the  strained  liquid  over  the  fire,  with  constant  agitation.     Ihe  starch 

♦  Memoir  of  Dr.  Fermin,  communicated  to  the  Academy  of  Berlin  concerning  experiment!  »ad«  at  Cay- 
enn*"  upon  ths  juice  of  the  Manioc. 

Vou  L  3D 


I 


386 


Casting  of  metals. 


dissolved  by  the  heat,  thickens  as  the  water  evaporates,  but  on  being  stirred,  it  becomes 
granulated,  and  must  be  finally  dried  in  a  proper  stove.  Its  speci6c  gravity  is  1-530  — 
that  of  the  other  species  of  starch. 

The  product  obtained  by  this  treatment  is  known  in  commerce  under  the  name  of  /o- 
pioca  ;  and  being  starch  very  nearly  pure,  is  oAen  prescribed  by  physicians  as  an  aliment 
of  easy  digestion.  A  tolerably  good  imitation  of  it  is  made  by  heating,  stirring,  and 
drying  potato  starch  in  a  similar  way.  cry        v  v 

The  expressed  juice  of  the  root  of  manioc  contains  in  suspension  a  very  fine  fecula,  whicn 
it  deposiies  slowly  upon  the  bottom  of  the  vessels.  When  freed  by  decantation  from  the  su- 
pernatant liquor,  washed  several  times  and  dried,  it  forms  a  beautiful  starch,  which 
creaks  on  pressure  with  the  fingers.  It  is  called  cipipa,  in  French  Guyana;  it  is 
employed  for  many  delicate  articles  of  cookery,  especially  pastry,  as  also  for  hair  powder, 
starching  linen,  &c. 

Cassava  flour,  as  imported,  may  be  distinguished  from  arrow-root  and  other  kmds 
of  starch,  by  the  appearance  of  its  particles  viewed  in  a  microscope.  They  are 
spherical,  all  about  1-lOOOth  of  an  inch  in  diameter,  and  associated  in  groups  ;  those  of 
potato  starch  are  irregular  ellipsoids,  varying  in  size  from  l-300th  to  l-3000th  of  an 
inch;  those  of  arrow-root  have  the  same  shape  nearly,  but  vary  in  size  from  l-500th  to 
l-800th  of  an  inch;  those  of  wheat  are  separate  spheres  1-lOOOth  of  an  inch. 

CASSIS,  the  black  currant  (jibes  nigra,  Linn.),  which  was  formerly  celebrated  for  its 
medicinal  properties  with  very  little  reason. 

The  only  technical  use  to  which  it  '^  now  applied  is  in  preparing  the  agreeable  limieur 
called  ratafia,  by  the  following  French  recipe : — Stone,  and  crush  three  pounds  of 
black  currants,  adding  to  the  magma  one  drachm  of  cloves,  two  of  cinnamon,  four 
quarts  of  spirit  of  wine,  at  98°  Baum6  (see  Areometre  of  Baume),  and  2i  pounds  of 
sugar.  Put  the  mixture  into  a  bottle  which  is  to  be  well  corked ;  let  it  digest  for  a 
fortnight,  shaking  the  bottle  once  daily  during  the  first  eight  days;  then  strain 
through  a  linen  cloth,  and  finally  pass  through  filtering  paper. 

CASSIUS,  purple  powder  of.  A  prep&ration  used  in  the  arts  as  a  colour,  chiefly  for 
stained  glass  and  porcelain.  It  is  also  employed  in  medicine  by  some  French  physicians, 
and  has  been  prepared  by  the  following  prescription : — 10  parts  of  acid  chloride  of  gold 
are  dissolved  m  2000  parts  of  water.  In  another  vessel,  10  parts  of  pure  tin  are  dis- 
solved in  10  parts  of  nitric  acid  mixed  with  20  parts  of  hydrochloric,  and  this  solution 
is  diluted  with  1000  parts  of  distilled  water.  The  solution  of  tin  is  added  by  degrees 
to  that  of  the  acid  chloride  of  gold,  as  long  as  any  precipitate  results  which  is  allowed 
to  subside ;  it  is  then  washed,  filtered,  and  then  dried  at  a  very  gentle  heat.  The  tin  salt 
above  used  contains  both  the  protoxide  and  binoxide  in  certain  proportions.  The 
double  compound  of  chloride  of  tin  with  sal  ammoniac,  called  the  ^link  salt  of  tin,  is 
the  preferable  form ;  as  it  is  not  altered  by  the  atmosphere,  is  of  definite  composition, 
and  when  boiled  with  metallic  tin  it  takes  up  just  so  much  as  will  form  the  protochlo- 
ride;  100  parts  of  pink  salt  require  for  this  purpose  lO"?  parts  of  metallic  tin. 

1-34  gr.  of  gold  are  to  be  dissolved  in  aqua  regia,  without  excess  of  the  solvent,  and 
this  solution  is  to  be  diluted  with  480  gr.  of  water.  Then  10  gr.  of  the  pink  salt 
mixed  with  1*07  gr.  of  tin  filings,  and  40  gr.  of  water,  are  to  be  exposed  to  a  boiling 
heat  till  the  metal  is  dissolved.  140  gr.  of  water  are  now  to  be  poured  upon  that  com- 
pound, and  the  resulting  solution  is  to  be  gradually  added  to  the  gold  liquor  (slightly 
warmed)  till  no  more  precipitate  forms.  Tliis  when  washed  and  dried  is  of  a  brown 
colour,  and  weighs  4-92  grs.  The  above  method  of  preparing  the  solution  of  the  ses- 
quioxide  of  tin  seems  to  be  the  best  hitherto  prescribed. 

CASTING  OF  METALS.  (See  Founding.)  Casts  from  elastic  matdds.— Being 
much  engaged  in  taking  easts  from  anatomical  preparations,  Mr.  Douglas  Fox,  Surgeon, 
Derby,  found  great  difficulty,  principally  with  hard  bodies,  which,  when  undercut,  or 
having  considerable  overlaps,  did  not  admit  of  the  removal  of  moulds  of  the  ordinary 
kind,  except  with  injury.  These  difficulties  suggested  to  him  the  use  of  elastic  moulds, 
which,  giving  way  as  they  were  withdrawn  from  complicated  parts,  would  return  to 
their  proper  shape ;  and  he  ultimately  succeeded  in  making  such  moulds  of  glue  which 
not  only  reUeved  him  from  all  his  difficulties,  but  were  attended  with  great  advantages, 
in  consequence  of  the  small  number  of  pieces  into  which  it  was  necessary  to  divide 
the  mould. 

The  body  to  be  moulded,  previously  oiled,  must  be  secured  one  inch  above  the  sur- 
face of  a  board,  and  then  surrounded  by  a  wall  of  clay,  about  an  inch  distant  from  its 
sides.  The  clay  must  also  extend  rath'er  higher  than  the  contained  body :  into  this, 
warm  melted  glue,  as  thick  as  possible  so  that  it  will  run,  is  to  be  poured,  so  as  to 
completely  cover  the  body  to  be  moulded ;  the  glue  is  to  remain  till  cold,  when  it  will 
have  set  into  an  elastic  mass,  just  such  as  is  required. 

Having  removed  the  clay,  the  glue  is  to  be  cut  into  as  many  pieces  as  may  be  ne- 
ceaeary  for  its  removal,  either  by  a  sharp-pointed  knife,  or  by  having  placed  threads  in 


CASTOR  OIL. 


SBt 


the  requisite  situations  of  the  body  to  be  moulded,  which  may  be  drawn  away  when 
the  glue  is  set,  so  as  to  cut  it  out  in  any  direction. 

The  portions  of  the  glue  mould  having  been  removed  from  the  original,  are  to  be 
placed  together  and  bound  round  by  tape. 

In  some  instances  it  is  well  to  run  small  wooden  pegs  through  the  portions  of  glue,  so 
as  to  keep  them  exactly  in  their  proper  positions.  If  the  mould  be  of  considerable  size, 
it  is  better  to  let  it  be  bound  with  moderate  tightness  upon  a  board  to  prevent  it 
bending  whilst  in  use  ;  having  done  as  above  described,  the  plaster  of  Paris,  as  in  com- 
mon casting,  is  to  be  poured  into  the  mould,  and  left  to  set 

In  many  instances  wax  may  also  be  cast  in  glue,  if  it  is  not  poured  in  whilst  too  hot ; 
as  the  wax  cools  so  rapidly  when  applied  to  the  cold  glue,  that  the  sharpness  of  the 
impression  is  not  injured. 

Glue  has  been  described  as  succeding  well  where  the  elastic  mould  is  alone  applica- 
ble; but  many  modifications  are  admissible.  When  the  moulds  are  not  used  soon 
after  being  made,  treacle  should  be  previously  mixed  with  the  glue  (as  employed  by 
printers)  to  prevent  it  becoming  hard. 

The  description  thus  given  is  with  reference  to  moulding  those  bodies  which  cannot 
be  so  done  by  any  other  than  an  elastic  mould  ;  but  glue  moulds  will  be  found  greatly 
to  facilitate  casting  in  many  departments,  as  a  mould  may  be  frequently  taken  by  this 
method  in  two  or  three  pieces,  which  would,  on  any  other  principle,  require  many. 

CAST-IRON  SCOURING.  Cast-iron  surfaces  are  said  to  be  easily  scoured  by  adding 
a  little  of  any  kind  of  organic  matter,  such  as  glycerine,  steariue,  napthaline,  creo- 
sote to  dilute  sulphuric  acid ;  zinc  and  brass  yield  to  the  same  method,  with  great 
economy  of  labour,  time  and  material, 

CASTOR.  (Eng.  and  Fr. ;  Biber,  Germ.)  The  castor  is  an  amphibious  quad> 
ruped,  inhabiting  North  America ;  also  found  in  small  numbers  in  the  islands  of  the 
Rhone.  In  the  arts,  the  skin  of  this  animal  is  employed  either  as  a  fur  or  as  affording 
the  silky  hair  called  beaver,  with  which  the  best  hats  are  covered.  Beaver  skins,  which 
form  a  very  considerable  article  of  trade,  are  divided  into  3  sorts  :  1.  The  fresh  beaver 
skins  from  castors,  killed  in  winter  before  shedding  their  hair;  these  are  most  in  re- 
quest among  the  furriers,  as  being  the  most  beautiful.  2.  The  dry  or  lean  beavers  are 
the  skins  of  the  animals  killed  during  the  moulting  season  ;  they  are  not  much  esteemed, 
as  the  skin  is  rather  bare.  3.  The  fat  castors :  these  are  the  skins  of  the  first  sort,  which 
have  been  worn  for  some  time  upon  the  persons  of  the  savages,  and  have  got  imbued  with 
their  sweat.  The  last  are  principally  used  in  the  hat  manufacture.  In  France,  the 
marine  otter  has  been  for  many  years  substituted  in  the  place  of  the  castor  oi 
beaver. 

CASTOR  or  CASTOREUM.  This  name  is  given  to  a  secretion  of  the  castor?, 
eoatained  in  pear-shaped  cellular  organic  sacs,  placed  near  the  genital  organs  of  both  ihe 
male  and  female  animals.  It  is  a  substance  analogous  to  civet  and  musk,  of  a  consist- 
ence similar  to  thick  honey.  It  has  a  bitter  acrid  taste ;  a  powerful,  penetrating,  fetid, 
and  very  volatile  smell ;  but,  when  dried,  it  becomes  inodorous.  Several  chemists,  and 
in  particular  Bouillon  Lasrrange,  Laugier,  and  Hildebrandt,  have  examined  castor,  and 
found  it  to  be  composed  of  a  resin,  a  fatty  substance,  a  volatile  oil,  an  extractive  matter, 
benzoic  acid,  and  some  salts. 

The  mode  of  preparing  it  is  very  simple.  The  sacs  are  cut  off  from  the  castors  when 
they  are  killed,  and  are  dried  to  prevent  the  skin  being  aflTected  by  the  weather.  In  this 
state,  the  interior  sub>tance  is  solid,  of  a  dark  color,  and  a  faint  smell ;  it  softens  with 
heat,  and  becomes  brittle  by  cold.  Its  fracture  betrays  fragments  of  membranes,  indi- 
cating its  organic  structure.  When  chewed,  it  adheres  to  the  teeth  somewhat  like  wax; 
it  has  a  bitter,  slightly  aciid,  and  nauseous  taste. 

The  castor  bags,  as  imported,  are  often  joined  in  pairs  by  a  kind  of  ligature.  Some 
times  the  substance  which  constitutes  their  value  is  sophisticated ;  a  portion  of  the  cas- 
toreum  being  extracted,  and  replaced  by  lead,  clay,  gums,  or  some  other  foreign  matters. 
This  fraud  may  be  easily  detected,  even  when  it  exists  in  a  small  degree,  by  the  absence 
of  the  membranous  partitions  in  the  interior  of  the  bags,  as  well  as  by  the  altered  smell 
and  taste. 

The  use  of  castoreum  in  medicine  is  considerable,  especially  in  nej  vous  and  spasmodic 
diseases,  and  it  is  often  advantageously  combined  with  opium. 

CASTORINE.  A  chemical  principle  lately  discovered  to  the  amount  of  a  few  parts 
per  cent,  in  Castoreum. 

CASTOR  OIL.  The  expressed  oil  of  the  seeds  of  the  Palma  Christi,  or  Ricinus 
communis,  a  native  tree  of  the  West  Indies  and  South  America  ;  but  which  has  been  cul- 
tivated in  France,  Italy,  and  Spain.  Bussy  and  Lecanu  discovered  in  it  3  species  of 
fatty  matters,  obtained  partly  by  saponification,  and  partly  by  dry  distillation — the  mar- 
garitic,  ricinic,  and  elaiodic  acids.  None  of  these  has  been  separately  applied  to  any 
use  in  the  arts. 

8D2 


I ' 


388 


CATECHU. 


CATGUT. 


389 


ilffil 


H 


The  quantity  of  castor  oil  imported  in  1835  into  the  United  Kingdom  was  1,109,307 
lbs. ;  retained  for  home  consumption,  670,205  lbs.     See  Oils. 

CATECHU,  absurdly  called  Terra  Japonica,  is  an  extract  made  from  the  wood  of 
the  tree  mimosa  catechu,  which  grows  in  Bombay,  Bengal,  and  other  parts  of  India.  It 
is  prepared  by  boiling  the  chips  of  the  interior  of  the  trunk  in  water,  evaporating  the 
solution  to  the  consistence  of  sirup  over  the  fire,  and  then  exposing  it  in  the  sun  to 
harden.  It  occurs  in  flat  rough  cakes,  and  under  two  forms.  The  first,  or  the  Bombay, 
is  of  uniform  texture,  of  a  dark  red  color,  and  of  specific  gravity  1*39.  The  second 
is  more  friable  and  less  solid.  It  has  a  chocolate  color,  and  is  marked  inside  with  red 
streaks.     Its  specific  gravity  is  1*28. 

According  to  Sir  H.  Davy,  these  two  species  are  composed  as  follows : — 


• 

Tannin  ------- 

Extractive     -        -                 -        .        - 

Mucilage        -        -        -        -        - 
Insoluble  matters,  sand  and  lime 

Bombay. 

Bengal.               | 

54-5 
34-0 

6-5 

5 

48-5 
36-5 

8 

7 

100-0 

100-0 

Areka  nuts  are  also  found  to  yield  catechu ;  for  which  purpose  they  are  cut  into 
pieces  watered  in  an  earthen  pot  with  solution  of  nitre,  and  have  a  little  of  the  bark  of 
a  species  of  mimosa  added  to  them.  The  liquor  is  then  boiled  with  the  nuts,  and  afl^ords 
mti  inspissated  decoction. 

Good  catechu  is  a  brittle,  compact  solid,  of  a  dull  fracture.  It  has  no  smell,  but  a 
Tcry  astringent  taste.  Water  dissolves  the  whole  of  it,  except  the  earthy  matter,  which 
IS  probably  added  during  its  preparation.  Alcohol  dissolves  its  tannin  and  extractive. 
The  latter  may  be  oxydized,  and  thus  rendered  insoluble  in  alcohol,  by  dissolving  the 
catechu  in  water,  exposing   it  for  some   time   to  a  boiling  heat,  and  evaporating   to 

dryness. 

The  tannin  of  catechu  differs  from  that  of  galls,  in  being  soluble  in  alcohol,  and  more 
soluble  in  water.  It  precipitates  iron  of  an  olive  color,  and  gelatin  in  a  mass  which 
gradually  becomes  brown. 

It  has  been  long  employed  in  India  for  tanning  j^ins,  where  it  is  said  to  effect  this  object 
in  five  days.  I  have  seen  a  piece  of  sole  leather  completely  tanned  by  it  in  this  country  in 
ten  days,  the  ox-hide  having  been  made  into  a  bag,  with  the  hair  outside,  and  kept  filled 
with  the  solution  of  catechu.  In  India  it  has  also  been  used  to  give  a  brown  dye  to 
cotton  ^oods,  and  of  late  ynars  it  has  been  extensively  introduced  into  the  calico  prmi 
works  of  Europe.  The  salts  of  copper  with  sal  ammoniac  cause  it  to  give  a  bronze 
color,  which  is  very  fast ;  the  proto-muriate  of  tin,  a  brownish  yellow ;  the  per-chloride 
of  tin,  with  the  addition  of  nitrate  of  copper,  a  deep  bronze  hue ;  acetate  of  alumina 
alone,  a  reddish  brown,  and,  with  nitrate  of  copper,  a  reddish  olive  gray  ;  nitrate  of  iron, 
a  dark  brown  gray.  For  dyeing  a  golden  coffee  brown,  it  has  entirely  superseded  mad- 
der; one  pound  of  it  being  equivalent  to  six  pounds  of  this  root. 

A  solution  of  one  part  of  catechu  in  ten  parts  of  water,  which  is  reddish  brown, 

exhibits  the  following  results :  with — 

.  A  brightened  shade. 

-  A  darkened  shade. 
.  Olive  blown  precipitate. 

-  Olive  green        do. 
.  Yellowish  brown. 
.  A  brightening  of  the  liquor. 

-  Olive  green  precipitate. 
.  Yellowish  brown  do. 


Acids 

Alkalis    -        -        - 
Proto-sulphate  of  iron 
Per-sulphjite  of  iron 
Sulphate  of  copper  - 
Alum      .        -        - 
Per-nitrate  of  iron  - 
Nitrate  of  copper     - 
Nitrate  of  lead 
Proto-nitrate  of  mercury 
Muriate  of  alumina 
Muriate  of  tin 
Per-chloride  of  tin  - 
Corrosive  sublimate 
Acetate  of  alumina  - 
Acetate  of  copper    - 
Acetate  of  lead 
Bichromate  of  potash 


Salmon  do. 

Milk-coffee  do. 

Brown-yellow. 
Do.         do. 
Do.      darker. 
Light  chocolate  do. 
Brightening  of  the  liquor. 
Copious  brown  precipitate 
Salmon  colored        do. 


-    Copious  brown        do. 
Pure  tannin  may  be  obtained  from  catechu,  by  treating  it  with  sulphuric  acid  and  car* 
bonate  of  lead ;  but  this  process  has  no  manufacturing  application. 


CATGUT  (Corde  a  boyau,  Fr. ;  i>armsaite,  Germ.),  the  name  absurdly  enough  given 
to  cords  made  of  the  twisted  intestines  of  the  sheep.  The  guts  being  taken  while  warm 
out  of  the  body  of  the  animal,  are  to  be  cleared  of  feculent  matter,  freed  from  any  ad- 
hering fat,  and  washed  in  a  tub  of  water.  The  small  ends  of  all  the  intestmes  ore 
next  to  be  tied  together,  and  laid  on  the  edge  of  the  tub,  while  the  body  of  them  is  left 
to  steep  in  some  water,  frequently  changed,  during  two^lays,  in  order  to  loosen  the 
peritoneal  and  mucous  membranes.  The  bundle  of  intestines  is  then  laid  upon  a 
sloping  table  which  overhangs  the  tub,  and  their  surface  is  scraped  with  the  back  of  a 
knife,  to  try  if  the  external  membrane  will  come  away  freely  in  breadths  of  about  half 
the  circumference.  This  substance  is  called  by  the  French  manufacturers  filandre,  and 
the  process  filer.  If  we  attempt  to  remove  it  by  beginning  at  the  large  end  of  the 
intestine,  we  shall  not  succeed.  This  filandre  is  employed  as  thread  to  sew  intestines, 
and  to  make  the  cords  of  rackets  and  battledoors.  The  flayed  guts  are  put  again  into 
fresh  water,  and,  after  steeping  a  night,  are  taken  out  and  scraped  clean  next  day,  on  the 
wooden  bench  with  the  rounded  back  of  a  knife.  This  is  called  curing  (he  gut.  The 
large  ends  are  now  cut  off,  and  sold  to  the  pork-butchers.  The  intestines  are  again 
steeped  for  a  night  in  fresh  water,  and  the  following  day  in  an  alkaline  lixivium  made 
by  adding  4  ounces  of  potash,  and  as  much  pearl-ash,  to  a  pail  of  water  containing  about 
3  or  4  imperial  gallons.  This  ley  is  poured  in  successive  quantities  upon  the  intestines, 
and  poured  off  again,  after  2  or  3  hours,  till  they  be  purified.  They  are  now  drawn 
several  times  through  an  open  brass  thimble,  and  pressed  against  it  with  the  nail,  in  or- 
der to  smooth  and  equalize  their  surface.  They  are  lastly  sorted,  according  to  their 
sizes,  to  suit  different  purposes.  . 

Whip-cord  is  made  from  the  above  intestines,  which  are  sewed  together  endwise  by  the 
filandre,  each  junction  being  cut  aslant,  so  as  to  make  it  strong  and  smooth.  The  cord 
is  put  inio  the  frame,  and  each  end  is  twisted  separately ;  for  whip-cord  is  seldom  made 
out  of  two  guts  twisted  together.  When  twisted,  it  is  to  be  sulphured  (see  Sulphuring) 
once  or  twice.  It  may  also  be  dyed  black  with  common  ink,  pink  with  red  ink,  which 
the  sulphurous  acid  changes  to  pink,  and  green  with  a  green  dye  which  the  color  dealers 
sell  for  the  purpose.  The  guts  take  the  dyes  readily.  After  being  well  smoothed,  the 
cord  is  to  be  dried,  and  coiled  up  for  sale.  . 

Hatters'  cords  for  bowstrings. — The  longest  and  largest  intestines  of  sheep,  after  being 
properly  treated  with  the  potash,  are  to  be  twisted  4,  6,  8,  10,  or  12  together,  according 
to  the  intended  size  of  the  cord,  which  is  usually  made  from  15  to  25  feet  long.  This 
cord  must  be  free  from  seams  and  knots.  When  half  dry,  it  must  be  exposed  twice  to 
the  fumes  of  burning  sulphur ;  and,  after  each  operation,  it  is  to  be  well  stretched  and 
imoothed :  it  should  be  finally  dried  in  a  state  of  tension. 

Clockmaker's  cord. — This  cord  should  be  extremely  thin,  and  be  therefore  made  from 
▼wy  small  intestines,  or  from  intestines  slit  up  in  their  length  by  a  knife  fitted  for  tha 
purpose;  being  a  kind  of  lancet  surmounted  with  a  ball  of  lead  or  wood.  The  wet  gut 
is  strained  over  the  ball  which  guides  the  knife,  and  the  two  sections  fall  down  into  a 
vessel  placed  beneath.  Each  hand  pulls  a  section.  Clockmakers  also  make  use  of 
stronger  cords  made  of  2  or  more  guts  twisted  tc^ether. 

Fiddle  and  harp  s/rings.  —These  require  the  greatest  care  and  dexterity  on  the  part 
of  the  workmen.  The  treble  strings  are  peculiarly  diflScult  to  make,  and  are  best  made 
at  Naples,  probably  because  thew  sheep,  from  their  small  size  and  leanness,  afford  the 

best  raw  material. 

The  first  scraping  of  the  guts  intended  for  fiddle-strings  must  be  very  carefully  performed ; 
and  the  alkaline  ley's,  being  clarified  with  a  little  alum,  are  added,  in  a  progressively  stronger 
state  from  day  to  day,  during  4  or  5  days,  till  the  guts  be  well  bleached  and  swollen. 
They  must  then  be  passed  through  the  thimble,  and  again  cleansed  with  the  lixivium; 
after  which  they  are  washed,  spun,  or  twisted  and  sulphured  during  two  hours.  They  are 
finally  polished  by  friction,  and  dried.  Sometimes  they  are  sulphured  twice  or  thrice 
before  being  dried,  and  are  polished  between  norse-hair  cords. 

It  has  been  long  a  subject  of  complaint,  as  well  as  a  serious  inconvenience  to  mu- 
sicians that  catgut  strings  cannot  be  made  in  England  of  the  same  goodness  and  strength 
as  those  imported  from  Italy.  These  are  made  of  the  peritoneal  covering  of  the  in- 
testines of  the  sheep ;  and,  in  this  country,  they  are  manufactured  at  Whitechapei,  and 
probably  elsewhere  in  considerable  quantity  ;  the  consumption  of  them  for  harps,  as 
well  as  for  the  instruments  of  the  violin  family,  being  very  great.  Their  chief  fault  is 
weakness ;  whence  it  is  diflicult  to  bring  the  smaller  ones,  required  for  the  higher  notes, 
to  concert'  pitch ;  maintaining  at  the  same  time,  in  their  form  and  construction,  that 
tenuity  or  smallness  of  diameter,  which  is  required  to  produce  a  brilliant  and  clear  tone. 

The  inconvenience  arising  from  their  breaking  when  in  use,  and  the  expense  in  the 
case  of  harps,  where  so  many  are  required,  are  such  as  to  render  it  highly  desirable  to 
improve  a  manufacture  which,  to  many  individuals  may,  however,  appear  sutficienay  con- 
temptible. 


390 


CEMENTS. 


CEMENTS. 


391 


It  IS  well  known  to  physioloslsts,  that  Ihe  membranes  of  lean  animals  are  far  more 
tough  than  of  those  animals  which  are  fat  or  in  high  condition ;  and  there  is  no  reason  to 
doubt  that  the  superiority  of  the  Italian  strings  arises  from  the  state  of  the  sheep  in  that 
country.  In  London,  where  no  lean  animals  are  slaughtered,  and  where,  indeed,  an 
extravagant  and  useless  degree  of  fattening,  at  least  for  the  purpose  of  food,  is  given  to 
sheep  in  particular,  it  is  easv  to  comprehend  why  their  membranes  can  never  afford  a 
material  of  the  requisite  tenacity.  It  is  less  easy  to  suggest  an  adequate  remedy ;  but  a 
knowledge  of  the  general  principle,  should  this  notice  meet  the  eyes  of  those  interested  in 
the  subject,  may  at  least  serve  the  purpose  of  diminishing  the  evil  and  improving  the  ma- 
nufacture, by  inducing  them  to  choose  in  the  market  the  ofl'al  of  such  carcasses  as  appear 
least  overburdened  with  fat.  It  is  probable  that  such  a  manufacture  might  be  advan- 
tageously established  in  those  parts  of  the  country  where  the  fashion  has  not,  as  in 
London,  led  to  the  use  of  meat  so  much  overfed ;  and  it  is  equally  likely,  that  in  the 
choice  of  sheep  for  this  purpose,  advantage  would  arise  from  usins  the  Welch,  the  High- 
land, or  the  Southdown  breeds,  in  preference  to  those  which,  like  the  Lincoln,  are  prone 
to  excessive  accumulations  of  fat.  It  is  equally  probable,  that  sheep  dying  of  some 
of  t\e  diseases  accompanied  by  emaciation,  would  be  peculiarly  adapted  to  this 
pnrf/>se. 

That  these  suggestions  are  not  merely  speculative  is  proved  by  comparing  the  strength 
of  the  membranes  in  question,  or  that  of  the  other  membranous  parts,  in  the  unfaltened 
Highland  sheep,  with  that  of  those  found  in  the  London  markets. 

CATHARTINE.  The  name  proposed  by  MM.  Feneulle  and  Lassaigne  for  a  chemi- 
cal principle,  which  they  suppose  to  be  the  active  constituent  of  senna. 

CAUSTIC.  Any  chemical  substance  corrosive  of  the  skin  and  flesh  j  as  potash,  called 
common  caustic,  and  nitrate  of  silver,  called  lunar  caustic,  by  surgeons. 

CAVIAR.  The  salted  roe  of  certain  species  of  fish,  especially  the  sturgeon.  This 
product  forms  a  considerable  article  of  trade,  being  exported  annually  from  the  town  of 
Astrachan  alone,  upon  the  shores  of  the  Caspian  sea,  to  the  amount  of  several  hundred 
tons.  The  Italians  first  introduced  it  into  Eastern  Europe  from  Constantinople,  under 
the  name  of  caviale.  Russia  has  now  monopolized  this  branch  of  commerce.  It  is  pre- 
pared in  the  following  manner  :  — 

The  female  sturgeon  is  gutted  ;  the  roe  is  separated  from  the  other  parts,  and  cleaned 
bypassing  it  through  a  very  fine  searce,  by  rubbing  it  into  a  pulp  between  the  hands; 
this  is  afterwards  thrown  into  tubs,  with  the  addition  of  a  considerable  quantity  of  salt ; 
the  whole  is  then  well  stirred,  and  set  aside  in  a  warm  apartment.  There  is  another 
sort  of  caviar,  the  compressed,  in  which  the  roe,  after  having  been  cured  in  strong  brine^ 
is  dried  in  the  sun,  then  put  into  a  task,  and  subjected  to  strong  pressure. 

CAWK.     The  English  miner's  name  for  sulphate  of  baryta,  or  heavy  spar, 

CEDRA  {Cedrat,  Fr.)  is  the  fruit  of  a  species  of  orange,  citron,  or  lemon,  a  tree  which 
bears  the  same  name.  Its  peel  is  very  thick,  and  covered  with  an  epidermis  which  en- 
closes a  very^  fragrant  and  highly  prized  essential  oil.  The  preserves  flavored  with  it 
■re  very  agreeable.  The  citrons  are  cut  into  quarters  for  the  dry  comfits,  but  are  put  whole 
into  the  liquid  ones.  The  liquorist-perfumer  makes  wit/i  the  peel  of  the  cedra  an  ex- 
cellent liqueur ;  for  which  purpose,  he  plucks  them  beft  re  they  arc  quite  ripe ;  grate? 
down  the  peel  into  a  little  brandy,  or  cirts  them  into  slices,  and  infuses  these  in  the 
spirits.  This  infusion  is  distilled  for  making  perfume;  but  the  flavor  is  better  wher. 
the  infusion  itself  is  used.     See  Essences,  Liquokist,  Perfumery. 

CELESTINE.  Native  sulphate  of  strontia,  found  abundantly  near  Bristol,  m  the 
red  marl  formation.  It  is  decomposed,  by  ignition  with  charcoal,  into  sulphuret  of 
strontia,  which  is  converted  into  nitrate  by  saturation  with  nitric  acid,  evaporation,  and 
crystallization.  This  nitrate  is  employed  for  the  production  of  the  red  light  in  theatrical 
fire-works. 

CEMENTATION.  A  chemical  process,  which  consists  in  imbedding  a  solid 
body  in  a  pulverulent  matter,  and  exposing  both  to  ignition  in  an  earthen  or  metallic 
case.  In  this  way,  iron  is  cemented  with  charcoal  to  form  steel,  and  bottle  glass  with 
gypsum  powder,  or  sand,  to  form  Reaumur's  porcelain. 

CEMENTS.  {Cimentsy  Fr. ;  Cdmente,  Kitte,  Germ.)  Si^bstances  capable  of  taking  the 
liquid  form,  and  of  being  in  that  stale  applied  between  the  surfaces  of  two  bodies,  po  as  to 
unite  them  by  solidifying.  They  may  be  divided  into  two  classes,  those  which  are  applieo 
through  the  agency  of  a  liquid  menstruum,  such  as  water,  alcohol,  or  oil,  and  those  which 
are  applied  by  fusion  with  heat. 

The  diamond  cement  for  uniting  broken  pieces  of  china,  glass,  &c.,  which  is  sold  as  a 
secret  at  an  absurdly  dear  price,  is  composed  of  isinglass  soaked  in  water  till  it  becomes 
soft,  and  then  dissolved  in  proof  spirit,  to  which  a  little  gum  resin,  ammoniac,  or  galba- 
num,  and  resin  mastic  are  added,  each  previously  dissolved  in  a  minimum  of  alcohol. 
When  to  be  applied,  it  must  be  gently  heated  to  liquefy  it;  and  it  should  be  kept  for 
use  in  a  well-corked  vial.     A  glass  stopper  would  be  apt  to  fix  so  as  not  to  be  remove 


able.     This  is  the  cement  employed  by  the  Armenian  jewellers  in  Turkey  for  glue- 
ing the  ornamental  stones  to  trinkets  of  various  kinds.      When  well  made  it  lesists 

moisture.  -  .  -  *.  j 

Shellac  dissolved  in  alcohol,  or  in  a  solution  of  borax,  forms  a  pretty  good  cemenu 
White  of  esg  alone,  or  mixed  with  finely  sifted  quicklime,  will  answer  for  uniting 
objects  which  are  not  exposed  to  moisture.  The  latter  combination  is  very  strong,  an^. 
is  much  employed  for  joining  pieces  of  spar  and  marble  ornaments.  A  similar  com- 
position is  used  by  copper-smiths  to  secure  the  edges  and  rivets  of  boilers ;  only  bullock's 
blood  is  the  albuminous  matter  used  instead  of  white  of  egg.  Another  cement  in  which 
an  analogous  substance,  the  curd  or  caseum  of  milk  is  employed,  is  made  by  boiling 
slices  of  skim-milk  cheeses  into  a  gluey  consistence  in  a  great  quantity  of  water,  and 
then  incorporating  it  with  quicklime  on  a  slab  with  a  muller,  or  in  a  marble  mortar. 
When  this  compound  is  applied  warm  to  broken  edges  of  stoneware,  it  unites  them  very 

firmly  after  it  is  cold. 

A  cement  which  gradually  indurates  to  a  stony  consistence  may  be  made  by  mixing 
20  parts  of  clean  river  sand,  two  of  litharge,  and  one  of  quicklime,  into  a  thin  putty 
with  linseed  oil.  The  quicklime  may  be  replaced  with  litharge.  When  this  cement  is 
applied  to  mend  broken  pieces  of  stone,  as  steps  of  stairs,  it  acquires  after  some  time  m 
stony  hardness.    A  similar  composition  has  been  applied  to  coat  over  brick  walls,  under 

the  name  of  mastic.  .  ■,  j       j 

The  iron-rust  cement  is  made  of  from  50  to  100  parts  of  iron  borings,  pounded  and 
lifted,  mixed  with  one  part  of  sal-ammoniac,  and  when  it  is  to  be  applied  moistened  with 
as  much  water  as  will  give  it  a  pasty  consistency.  Formerly  flowers  of  sulphur  were  used, 
and  much  more  sal-ammoniac  in  making  this  cement,  but  with  decided  disadvantage,  as 
the  union  is  effected  by  the  oxydizement,  consequent  expansion  and  solidification  of  the 
iron  powder,  and  any  heterogeneous  matter  obstructs  the  effect.  The  best  proportion  of 
sal-ammoniac  is,  I  believe,  one  per  cent,  of  the  iron  borings.  Another  composition  of  the 
same  kind  is  made  by  mixing  4  parts  of  fine  borings  or  filings  of  iron,  2  parts  of  potter's 
clay  and  1  part  of  pounded  potsherds,  and  making  them  into  a  paste  with  salt  ana 
water.     When  this  cement  is  allowed  to  concrete  slowly  on  iron  joints,  it  becomes  very 

For  making  architectural  ornaments  in  relief,  a  moulding  composition  is  formed  of 
chalk,  glue,  and  paper  paste.    Even  statues  have  been  made  with  it,  the  paper  aiding  the 

cohesion  of  the  mass.  j       /•      j  v    v     . 

Mastics  of  a  resinous  or  bituminous  nature  which  must  be  softened  or  fused  by  heal 

%re  the  following : —  ,.         .^    ,        ,   ^  . ,    j  •  j  v    - 

Mr.  S.  Valley's  consists  of  sixteen  parts  of  whiting  sifted  and  thoroughly  dried  by  t 
red  heat,  adding  when  cold  a  melted  mixture  of  16  parts  of  black  rosin  and  1  of  bees'-wax, 
and  stirring  well  during  the  cooling.  ^        -      ■,     e 

Mr.  Singer's  electrical  and  chemical  apparatus  cement  consists  of  5  lbs.  of  rosin«  1  of 
hees'-wax,  1  of  red  ochre,  and  two  table-spoonsful  of  Paris  plaster,  all  melted  together. 
A  cheaper  one  for  cementing  voltaic  plates  into  wooden  troughs  is  made  with  6  pounds 
of  rosin,  1  pound  of  red  ochre,  |  of  a  pound  of  plaster  of  Paris,  and  ^  of  a  pound  of  lin- 
seed oil.  The  ochre  and  the  plaster  of  Paris  should  be  calcined  beforehand,  and  added 
to  the  other  ingredients  in  their  melted  slate.  The  thinner  the  stratum  of  cement  that 
is  interposed,  the  stronger,  generally  speaking,  is  the  junction. 

Boiled  linseed  oil  and  red  lead  mixed  together  into  a  putty  are  often  used  by  copper- 
smiths and  engineers,  to  secure  joints.  The  washers  of  leather  or  cloth  are  smeared 
with  this  mixture  in  a  pasty  state. 

The  resin  mastic  alone  is  sometimes  used  by  jewellers  to  cement  by  heat  cameos  of 
white  enamel  or  colored  glass  to  a  real  stone,  as  a  ground  to  produce  the  appearance  of 
an  onyx.     Mastic  is  likewise  used  to  cement  false  backs  or  doublets  to  stones,  to  alter 

their  hue. 

Melted  brimstone,  either  alone,  or  mixed  with  rosin  and  brick  dust,  forms  a  tolerably 

good  and  very  cheap  cement. 

Plumber's  cement  consists  of  black  rosin  one  part,  brick  dust  two  parts,  well  incorpo- 
rated by  a  melting  heat. 

The  cement  of  dihl  for  coating  the  fronts  of  buildings  consists  of  linseed  oil,  rendered 
dry  by  boiling  with  litharge,  and  mixed  with  porcelain  clay  in  fine  powder,  to  give  it  the 
consistence  of  stiff  mortar.  Pipe-clay  would  answer  equally  well  if  well  dried,  and  any 
color  might  be  given  with  ground  bricks,  or  pottery.  A  little  oil  of  turpentine  to  thin 
this  cement  aids  its  cohesion  upon  stone,  brick,  or  wood.  It  has  been  applied  to  sheets 
of  wire  cloth,  and  in  this  state  laid  upon  terraces,  in  order  to  make  them  water  tight;  but 
it  is  little  less  expensive  than  lead.  j  u     u      j 

The  bituminous  or  black  cement  for  bottle-corks  consists  of  pitch  hardened  by  the  ad- 
dition of  rosin  and  brick-dust.  -    -    a  -^ 

In  certain  localities  where  a  limestone  impregnated  with  bitumen  occurs,  it  is  dried. 


:  i 


f|i 


392 


CEMENTS. 


li 


II 


ground,  sifted,  and  then  mixed  with  about  its  own  weight  of  melted  pitch,  either  mineral, 
vegetable,  or  that  of  coal  tar.  When  this  mixture  is  getting  semifluid,  it  may  be  moulded 
into  large  slabs  or  tiles  in  wooden  frames  lined  with  sheet  iron,  previously  smeared  over 
with  common  lime  mortar,  in  order  to  prevent  adhesion  to  the  moulds,  which,  being  m 
moveable  pieces,  are  easily  dismounted  so  as  to  turn  out  the  cake  of  artificial  bituminous 
stone.  This  cement  is  manufactured  upon  a  great  scale  in  many  places,  and  used  for 
makins:  Italian  terraces,  covering  the  floors  of  balconies,  flat  roofs,  water  reservoirs,  water 
conduits,  &c.  AVhen  laid  down,  the  joints  must  be  well  run  together  with  hot  irons.  The 
floor  of  the  terrace  should  be  previously  covered  with  a  layer  of  Paris  plaster  or  common 
mortar,  nearly  an  inch  thick,  with  a  regular  slope  of  one  inch  to  the  yard.  Such  bitumin- 
ous cement  weighs  144  pounds  the  cubic  foot ;  or  a  foot  of  square  surface,  one  inch  thick, 
weighs  12  pounds.  Sometimes  a  second  layer  of  these  slabs  or  tiles  is  applied  oyer  the 
first,  with  the  precaution  of  making  the  seams  or  joints  of  the  upper  correspond  with  the 
middle  of  the  under  ones.  Occasionally  a  bottom  bed,  of  coarse  cloth  or  gray  paper,  is 
applied.  The  larger  the  slabs  are  made,  as  far  as  they  can  be  conveniently  transported 
and  laid  down,  so  much  the  better.    For  hydraulic  cements,  see  Mortar. 

An  excellent  cement  for  resisting  moisture  is  made  by  incorporating  thoroughly 
eight  parts  of  melted  glue,  of  the  consistence  used  by  carpenters,  with  four  parts  of 
linseed  oil,  boiled  into  varnish  with  litharge.  This  cement  hardens  in  about  forty-eight 
hours,  and  renders  the  joints  of  wooden  cisterns  and  casks  air  and  water  tight  A 
compound  of  glue  with  one-fourth  its  weight  of  Venice  turpentine,  made  as  above, 
serves  to  cement  glass,  metal  and  wood,  to  one  another.  Fresh-made  cheese  curd,  and 
old  skim-milk  cheese,  boiled  in  water  to  a  slimy  consistence,  dissolved  in  a  solution  of 
bicarbonate  of  potash,  are  said  to  form  a  good  cement  for  glass  and  porcelain.  Tlie 
gluten  of  wheat,  well  prepared,  is  also  a  good  cement  White  of  eggs,  with  flour  and 
water  well-mixed,  and  smeared  over  linen  cloth,  forms  a  ready  lute  for  steam  joints  in 

small  apparatus.  -,  ^     ^      ^    ^        *.    i     r 

White  lead  ground  upon  a  slab  with  linseed  oil  varnish,  and  kept  out  of  contact  of 
air,  affords  a  cement  capable  of  repairing  fractured  bodies  of  all  kinds.  It  requires  a 
few  weeks  to  harden.  When  stone  or  iron  are  to  be  cemented  together,  a  compound 
of  equal  parts  of  sulphur  with  pitch  answers  very  well. 

Mr.  Joseph  Gibbs,  a  practical  civil  engineer  of  eminence,  obtained  a  patent  in  May, 
1850  for  improvements  in  artificial  stone,  mortar  and  cements,  and  in  the  modes  of 
manufacturing  the  same,  of  which  the  following  abstract  is  worthy  of  attention 

"The  several  descriptions  of  Roman  cement  are  made  from  the  septaria  of  either 
Harwich  or  Sheppey  or  from  the  septaria  of  the  lias  formation,  or  from  beds  of  cement 
stone  found  in  the  upper  division  of  the  lias  formation,  or  in  the  shale  beds^  of  the 
Kimmeridge  clay.  All  these  stones,  when  manufactured,  produce  a  material  oi  a  dark 
brown  colour,  unfit  for  incrusting  buildings  so  as  to  imitate  stone,  unless  they  are 
either  coloured  by  washes,  or  by  painting.  N  ow,  amongst  the  advantages  to  be  obtained 
from  the  cements  and  mortars  I  have  invented  is  this,  that  every  description  of  freestone 
may  be  exactly  imitated  without  any  wash  or  painting  whatsoever  being  applied. 

"Again  the  cement  called  Portland  cement  is  made  by  mixing  clay  and  chalk,  or 
river  mud  and  chalk,  in  such  proportions  together  that  the  combined  materials  may 
contain  about  the  same  proportions  of  lime,  silica,  and  alumina,  as  are  found  m  cements. 
These  materials  are  ground  together  in  water  to  a  great  degree  of  faneness.  After 
subsidence,  and  also  after  obtaining  the  proper  consistency,  the  pasty  materials  are  dned 
in  kilns,  or  otherwise,  and  afterwards  burned  like  ordinary  cements  m  calcining  kilns. 
The  materials  are  then  ground  in  proper  mills.  To  these  materials,  so  prepared  and  so 
ground,  are  added  from  one-third  to  one-half  of  their  weight  in  slag  of  copper  smelting 
or  other  furnaces,  or  the  slag  of  over-burnt  cement,  which,  combmmg  with  the  lime  and 
silica,  forms  a  cement  which  is  much  nearer  the  colour  of  stone  than  any  of  the  Koman 
cements  heretofore  made.  Now,  as  the  combination  of  chalk  and  clay,  or  river  mud,  is 
expensive  when  manufactured,  and  causes  these  cements  to  be  very  dear ;  and  further, 
as  the  materials  are  only  combined  mechanically  and  not  chemically,  there  is  neither 
uniformity  in  their  quality,  nor  can  reliance  be  always  placed  on  their  stability  ;  the 
object  of  my  invention,  therefore,  is  to  lessen  the  expense  of  manufacturing  artitcial 
stone  mortars,  and  cements,  and  produce  a  superior  quality  of  cement  to  those  now  in 


use. 


My  invention  divides  itself  into  three  parts;  the  first  of  which  relates  to  mortar 
and  cements,  the  second  to  the  manufacture  of  artificial  stone,  and  the  third  to  the 
modes  of  manufacturing  the  said  mortar  cements,  and  artificial  stone. 

"I  have  found  by  research,  analysis,  and  much  experience,  that  there  exists  in  nature 
vast  beds  of  argillaceous  maris  and  mariy  limestones,  or  mari  stones,  which  contain  tha 
due  admixture  of  lime,  silica,  and  alumina,  from  which  hydraulic  cements  and  artificial 
stone  may  be  manufactured.    The  principal  places  for  findmg  this  mari  and  marly 


CEMENTS. 


398 


limestone  (geologically  speaking)  are  the  chalk  formation,  the  Wealden  formation  the 
Purbeck  beds,  the  lias  formation,  the  mountain  limestone,  and  the  lowest  strata  ot  the 
coal  measures.  In  the  chalk  formation,  the  mari  will  be  found  immediately  at  the 
junction  of  chalk  with  and  just  above  the  green  sand;  in  that  division  of  the  sand 
usually  called  '  gault,'  or  at  such  places  where  the  fire-stone  (or,  as  it  is  sometimes 
called;  the  'malen  rock')  exists,  interposing  between  the  gault  and  the  cha  k  marl 
This  chalk  mari  possesses  a  varying  character,  increasing  in  the  amount  ot  silica  ana 
alumina  as  it  approaches  either  the  malen  rock  or  the  gault ;  in  fact,  sometimes  when 
there  is  no  malen  rock  (or  fire-stone)  the  gault  becomes  a  calcareous  mari,  charged  witn 
sufficient  lime  to  make  a  cement,  but  the  amount  of  silica  and  alumina,  and  lime  com- 
posing the  marL  can  only  be  ascertained  by  experiment  The  upper  beds  of  marl,  and 
those  nearest  to  the  greystone  rock  of  the  chalk  formation,  will  make  hydraulic  mortar 
quite  equal,  and  often  superior,  to  the  best  lias  lime;  and  the  lower  beds  will  make 
cement  equal  to  Roman  cement,  except  that  it  does  not  contain  a  very  noticeable 
quantity  of  either  manganese  or  iron ;  consequently  it  is  of  hght  stone  colour  when 
manufactured,  and  is  better  adapted  to  cover  buildings,  and  represent  stone.  The  chalk 
mari  may  readily  be  found  by  the  springs  of  water  which  issue  from  the  back  or 
escarpment  face  of  the  chalk  formation,  and  above  these  springs  (but  m  close  proximity 
thereto)  the  hydraulic  lime  will  be  found,  and  below  the  springs  the  materials  for 
making  cement  must  be  extracted.  ,     ,     ttt    i  ^      ^         i.- 

"The  proper  place  for  obtaining  the  marly  limestone  in  the  Wealden  fomation  ism 
what  are  termed  by  geologists  the  Ashburuham  beds,  above  and  below  and  m  imme- 
diate contact  with  the  Ashburnham  limestone.  These  limestone  maris  are  like  perfect 
limestone  when  first  extracted,  but  decompose  by  exposure  to  the  air  after  a  short  time. 
The  limestone  itself,  in  particular  localities,  sometimes  become  a  cement-stone  or  marl 
stone,  which  may  be  known  by  its  not  slackening  in  water  after  calcination. 

"The  material  for  making  cement  out  of  the  beds  of  Purbeck  limestone  is  obtained 
from  some  of  the  partings  which  divide  the  ordinary  Purbeck  beds  of  limestone,  and 
is  exceedingly  well  calculated  to  make  a  cement  of  great  purity  and  whiteness,  but  all 
the  beds  do  not  contain  in  their  partings  the  quality  desired,  but  the  proper  material 
may  be  readily  found  by  noticing  the  decomposing  character  of  the  shale  when  ex- 

^^The'^materials  which  I  extract  from  the  lias  formation,  locally  called  'i-ummell'  at 
the  lime  quarries  at  Barrow-on-Soar,  in  Leicestershire,   is  an  especial  bed  o[  marty 
limestone,  found  above  and  separated  from  all  the  lias  beds  of  limestone  in  that  di^ 
trict     The  same  bed  of  '  rummell '  is  found  in  other  districts  of  the  has  formation,  and 
may  be  readily  observed  on  the  coast  of  Dorsetshire,  near  Lyme  Regis.     It  is  seen  on  the 
face  of  the  liniestone  cliffs,  imbedded  in  a  mariy  shale,  the  whole  of  which  decomposes 
on  exposure  to  the  air.    This  bed  of  '  rummell '  has  no  local  name  in  the  district  of  Lyme 
Regis,  not  having  hitherto  been  applied  to  any  useful  purpose ;  but  it  may  be  easily 
found,  as  it  exists  in  a  deep  bed  of  shale  between  the  lias  limestone  beds  and  the  beds 
of  cement  stone  which  heretofore  have  been  worked,  and  are  so  now  (but  the  cement 
from  this  last-named  stone  is  of  a  deeper  brown  colour,  and  unfit  for  imitating  stone, 
whilst  the  bed  of  '  rummell '  will  make  a  cement  of  a  light  colour  exactly  like  freestone). 
"  In  some  cases,  as  when  I  use  the  hardening  materials  (to  be  hereafter  described) 
in  combination  with  the  calcareous  marls  from  the  lias  formation    I  use  sonie  of  the 
partings  of  calcareous  shale  existing  between  the  lias  beds  of  workable  limestone,  pro- 
vided Such  calcareous  partings  or  shale  beds  contain  sufficient  lime,  which  shale,  after 
calcination,  I  combine  with  the  hardening  material,  in  the  manner  hereafter  to  be 
directed,  either  by  itself  or  in  combination  with  the  '  rummell    of  this  formation  along 

with  the  hardening  materials.  „         ,  ,  .  .      -e 

"  The  materials  which  I  extract  to  make  cements  from  the  mountain  or  carboniterous 
limestone  are  only  found  in  the  upper  part  of  that  great  deposit,  and  must  be  sought 
for  in  or  at  the  immediate  junction  of  the  limestone  shale  (which  shale  lies  under  the 
mill-stone  grit,  and  above  the  mountain  or  carboniferous  limestone,  dividing  the  two 
formations)  These  materials  consist  of  mountain  limestone,  limestone  shale,  and  bas- 
tard limestone  (that  is,  the  limestone  which  will  not  slack  after  calcination,  but  still 
retains  its  shape  after  being  dipped  in  water).  These  two  materials  are  found 
above  the  beds  of  workable  limestone,  which  beds  are  wrought  for  making  ordinary 
limes  (the  shales  and  the  bastard  limestone,  or  limestone  mari,  being  always  tound 
together).  These  shales  produce  a  dark  cement,  but  the  bastard  limestone  produces  a 
cement  of  a  light  stone  colour,  and  therefore  more  fit  for  imitating  stone. 

"  In  addition  to  these  substances,  I  extract  from  this  formation  sparry  iron  stone,  to 
make  hardening  materials  with.  a.         r 

"The  materials  which  I  extract  from  the  coal  measures  for  making  cement,  or  for 
mixing  with  the  other  cementitious  materials,  are  found  only  in  the  lowest  beds  of  the 
coal  measures,  often  connected  with  the  last  two  seams  of  coal,  and  before  that 

Vol.  L  3  E 


! 


394 


CEMENTS. 


I 


stratum  the  millstone  grit.  These  cementitious  materials  consist,  first,  of  the  coal  8hal« 
(called  metals  by  miners),  and  round  septaria  nodules  (boilams  by  the  local  miners 
about  Congleton  in  Cheshire).  The  'metals'  will  not  in  all  cases  make  cement,  but 
most  of  them  in  contact  with  the  boilams  (or  septaria  balh)  will  do  so.  These  boilams 
are  composed  chemically  of  sulphur,  lime,  iron,  and  manganese,  and  are  therefore 
easily  distinguishable ;  they  are,  in  fact,  a  species  (as  well  as  the  '  metals ')  of  pyrites. 
The  '  metals '  and  the  septaria  balls  make  excellent  cement,  of  great  hardness,  but  of 
dark  colour.  I  use,  however,  this  cement,  as  well  as  other  materials,  in  mixing  with 
Bome  of  the  cements  1  have  before  specified,  to  give  them  hardness — the  process  of 
doing  wlvich,  and  the  nature  of  the  materials,  will  be  described  hereafter — such  ma- 
terials wiil  be  called  hardening  materials. 

"  When  any  of  the  materials  just  enumerated  are  to  be  made  into  cements,  the  usual 
course  of  proceeding  for  making  cements  is  to  be  followed ;  that  is,  by  burning  in 
kilns  and  grinding  in  mills,  in  the  way  cement  is  now  manufactured  ;  but  I  recommend 
that  the  marls  and  marl  stones  be  first  dried  in  kilns  or  ovens,  at  a  heat  fit  for  baking 
until  all  moisture  be  driven  off^  and  that  then  the  calcination  be  prolonged  as  much  as 
possible,  but  that  the  heat  be  kept  so  low  as  is  only  just  sufficient  to  effect  complete 
calcination, — this  being  indispensable,  to  avoid  the  commencement  of  vitrification, 
which  would  destroy  the  adhesive  properties  of  the  cement.  These  observations  will 
be  found  equally  applicable  to  kilns,  such  as  are  now  in  use,  or  to  the  kiln  of  the  im- 
proved description,  to  be  described  hereafter,  and  which  forms  part  of  this  invention. 

"  Although  I  have  described  certain  new  materials  for  making  cements  and  mortars 
therefrom,  and  such  materials  are  capable  of  forming  good  cements  without  any  ad- 
mixture whatever,  yet,  in  some  cases,  I  make  a  composition  of  the  various  cements  to 
obtain  particular  qualities ;  thus,  for  instance,  I  take  a  quantity  of  the  pyrites  septaria, 
called  boilams,  and  mix  it  with  an  equal  quantity  of  the  chalk  marl  before  described. 
In  this  case  the  chalk  marl  keeps  the  colour  light,  and  the  septaria  or  boilams  of  the 
coal  measures  before  described  give  to  the  chalk  marl  a  considerable  degree  of 
hardness.  I  also  make  a  mixture  of  equal  parts  of  the  bastard  limestone  before  de- 
scribed for  a  like  purpose,  and  with  the  same  result ;  but  with  the  '  rummells '  of  the 
lias  formation  before  described,  or  the  rich  argillaceous  shale  of  that  formation,  no\ 
more  than  one-third  or  one-quarter  part  by  weight  of  the  septaria  or  boilams  is  need 
ful  to  give  great  hardness  and  strength  to  the  cement  made  therefrom.  The  same  ob 
servation  applies  to  the  cement  stone  of  the  Ashburnham  beds  already  described,  a» 
well  as  the  cement  made  from  the  interposing  Purbeck  shale  partings. 

"  But  in  many  cases  a  cement  is  required  of  a  hardness  beyond  what  would  bf 
aflForded  from  either  of  the  cement  stones  I  have  described,  or  the  mixture  of  two  oi 
more  of  them  together ;  and  in  these  cases  I  use  substances  to  be  combined  with  any 
of  these  cement  stones  or  their  mixtures,  which  I  have  called  'hardening  materials. 
These  materials  (in  addition  to  the  one  I  have  described,  namely,  the  pyritous  septaria 
or  boilams)  consist  — 

"  First :  Of  the  slag  or  cinder  derivable  from  iron  blast  furnaces. 

"  Secondly :  Slag  from  puddle  furnaces,  or  from  reheating  or  mill  furnaces. 

"Thirdly :  Slag  derivable  from  copper,  lead,  or  tin  furnaces,  or  the  slag  from  cement 
kilns. 

**  Fourthly :  The  sparry  iron  of  the  carboniferous  strata. 

"  Fifthly :  The  pyritous  earth  known  by  geologists  as  Folkestone  pyrites,  which 
pyritous  earth  is  a  thin  lamina,  or  bead,  or  band  of  earth,  in  concretions  just  below 
the  gault  strata,  and  which  it  separates  from  the  rock  and  sand  bed  just  below  the  gault. 
The  pyrites  may  be  found  in  other  places  in  similar  positions ;  but  the  locality  just  in- 
dicated, namely,  Folkestone  in  Kent,  will  be  a  sufficient  guide  to  find  a  similar  material 
elsewhere.  This  pyritous  earth  may  be  calcined  in  ordinary  lime  kilns,  the  same  as 
the  cement  stones  I  have  before  enumerated.  If  this  pyrites  be  mixed  with  chalk 
marl  or  any  other  of  the  white  cement  stones  I  have  before  mentioned,  the  imitation  of 
stone  will  be  very  exact,  and  may  be  sculptured  afterwards  with  the  same  facility  as 
ordinary  freestone.  The  same  effect  may  be  produced  by  mixing  in  the  like  propor 
tions  this  calcined  pyritous  earth  with  the  artificial  hydraulic  cements  now  commonly 
made  (and  which  cements  are  composed  of  chalk  and  clay,  or  mud,  in  due  proportions, 
and  ground  together  before  calcination),  the  pyritous  earth  or  Folkestone  pyrites  dis- 
placing in  thid  case  the  ground  slag  with  which  such  cements  are  now  usually  combined. 

"  The  various  slags  and  cinders  require  only  to  be  ground  under  edgestones  to  a  fine 
powder,  and  then  to  be  mixed  with  any  of  the  various  cements  I  have  enumerated, 
namely,  the  cement  from  the  chalk,  the  cement  from  the  lias,  the  cement  from  the 
Wealden  and  Furbeck  beds,  the  cement  from  the  mountain  limestone,  and  the  cement 
from  the  coal  measures ;  these  mixtures  must  be  effected  by  sifting  the  materials  together, 
or  by  some  other  mode  which  will  effectually  incorporate  and  combine  them ;  and  the 


CHAINWORK. 


395 


quantities  may  be  generally  from  one  quarter  (by  weight)  to  one  of  slag,  mixed -with 

''''«  ?nsomrcase?r  grind  pyritous  septaria  of  the  coal  measures,  or  other  equivalent 
materials  (having  the  same  chemical  properties),  into  a  fine  powder,  and  mix  such 
powder  with  aboSt  its  equal  weight  of  some  of  the  calcareous  mar  s  after  they  are  made 
Fnto  cement,  instead  of  mixing  such  marls  with  the  slags,  or  with  the  calcined  Pyntes  of 
Folkestone,  as  before  directed.  In  other  cases,  I  mix  with  the  cement  made  trom 
chalk  or  other  marls  an  equal  weight  of  any  of  the  cements  now  in  use,  or  ol  the 
calcined  septaria  of  the  London  clay  basin,  called  Roman  cement  stone  more  especially 
that  part  of  it  which  is  called  sandstone ;  but  in  the  case  of  using  any  of  the  septaria  ol 
the  London  clay,  the  marl  and  the  stone  may  be  calcined,  and  ground  together  in  equal 
proportions,  or  thereabouts.  .         , 

"Claims  —1st  The  manufacture  of  mortar  and  cement  from  chalk  marls,  tlie  cal- 
careous marls  of  the  Ashburnham  beds,  the  calcareous  shales  of  the  Purbeck  formation, 
the  rummell  beds  of  the  lias  formation,  the  calcareous  and  mountain  hmestome  shales, 
bastard  limestone  and  the  *  metals,'  and  pyritous  septaria  of  the  coal  formation,  all  or 
any  of  them,  when  prepared  for  the  purpose  by  grinding  or  pounding,  and  by  treating 
with  water  as  described,  and  whether  the  same  are  combined  or  not  combined  with 
certain  hardening  materials  (afterwards  specified),  or  other  cementitious  substances. 

"  2  The  use  of  the  '  hardening  materials'  described,  when  used  in  combination  with 
any  of  the  calcareous  substances  enumerated  in  the  preceding  claim,  or  in  combmation 
with  any  other  natural  calcareous  marl  or  marlstones. 

"  3  The  use  of  the  calcined  Folkestone  pyritous  earth,  the  sparry  ironstone  or  white 
ironstone  of  the  mountain  limestone,  and  the  calcined  pyritous  septaria  of  the  coal 
measures,  as  '  hardening  materials'  in  combination  with  any  artiticially-formed  cement 
composed  of  chalk,  or  lime  and  clay,  ground  and  calcined  m  the  manner  now  usually 
practised  for  manufacturing  artificial  cements. 

"4  The  mixture  of  any  of  the  before  described  marls  or  marlstones,  or  pyritous 
septaria,  from  the  coal  measures,  with  each  other,  or  with  any  of  the  water  cemenU  or 
limes  now  in  use,  or  the  materials  of  which  the  same  are  composed. 

"  5.  A  particular  process  of  grinding  and  pounding  cement  and  materials  mixed 

therewitli,  as  described.  .,.,..,         i  *.  i 

"  6.  The  consolidation  of  cement  and  materials  mixed  with  such  cement  by  concus- 
sion, for  forming  blocks  or  other  solid  shapes  in  moulds. 

«  7  A  process  of  making  artificial  stone  by  putting  plastic  materials  between  lattices 
or  other  convenient  forms ;  and  also  certain  methods  of  casting  hollow  parallelograms 
in  cement,  to  be  afterwards  filled  up  with  concrete,  for  walls  of  artificial  stone. 

"  8  The  use  of  a  kiln,  with  fire-vaults  under  the  whole  area  of  such  kiln,  such  vaults 
communicating  with  each  other  in  various  directions  through  spaces  between  the  bncks 

composing  such  vaults.  .       ,.  ,^         j        -i,  j  r 

"  9  The  use  of  a  brick  with  projections  for  constructing  fire-vaults,  as  described,  tor 
calcining  marls,  marlstones,  cements,  and  other  materials  used  for  making  metallic 

"  10.  The  use  of  a  circular  or  continuous  kiln,  for  the  purpose  of  making  mortars 

CERASIN.  The  name  given  by  Dr.  John  to  those  gums  which  swell,  but  do  not 
dissolve   in   water;    such  as  gum  tragacanth.      It   is  synonymous  with  Bassorink, 

CERATE,  from  cerOy  wax.  An  unguent,  of  rather  a  stiff  consistence,  made  of  oil,  or 
Urd  and  wax,  thickened  occasionally  with  pulverulent  matters. 

CERINR  A  substance  which  forms  from  70  to  80  per  cent,  of  bees  -wax.  It  may 
be  obtained  by  digesting  wax,  for  some  time,  in  spirits  of  wine,  at  a  boiling  temperature. 
The  viyricine  separates,  while  the  cerine  remains  dissolved,  and  may  be  obtained  from 
the  decanted  liquor  by  evaporation.  Cerine  is  white,  analogous  to  wax,  fusible  at 
184°  F  hardly  acted  upon  by  hot  nitric  acid,  but  is  readily  carbonized  by  hot  sul- 
phuric 'acid.     When  treated  with  caustic  alkaline  lye,  it  is  converted  into  margaric  acid 

and  ceraine.  ,  .      ,  •        •,       ^^  3        -^     r      a 

CERIUAL  A  peculiar  metal  discovered  in  the  rare  mineral,  called  cente,  louna 
only  in  the  copper  mines  of  Bastnaes,  near  Riddarhytta,  in  Sweden.  Ceriuni  extracted 
from  its  chloride  by  potassium,  appears  as  a  dark  red  or  chocolate  powder,  which 
assumes  a  metallic  lustre  by  friction.  It  does  not  conduct  electricity  well,  like  other 
metals ;  it  is  infusible ;  its  specific  gravity  is  unknown.     It  has  been  applied  to  no  use 

CERUSK    A  name  of  white  lead.    See  Lead  and  Wbtie  Lead. 
CETINK     The  name  given  by  Chevreul  to  spermaceti 

CHAINWORK  is  a  peculiar  style  of  textile  fabric,  to  which  hosiery  and  tambour- 
ing belong.    Sec  Hosieey. 

8£2 


f 


896 


CHAMELEON  MINERAL. 


CHALK.  {Craie,  Fr. ;  Kreide,  Germ.)  A  friable  carbonate  of  lime,  white,  opaqne, 
Boft,  dull,  or  without  any  appearance  of  polish  in  its  fracture.  Its  specific  gravity  varies 
from  2-4  to  26.  It  usually  contains  a  little  silica,  alumina,  and  oxide  of  iron.  It 
may  be  purified  by  trituration  and  elutriation.  The  siliceous  and  ferruginous  matters 
subside  first,  and  the  finer  chalky  particles  floating  in  the  supernatant  liquid  may  be 
decanted  with  it,  and  obtained  by  subsidence.  When  thus  purified,  it  is  called  whitening 
and  Spanish  white,  in  England ;  schlemmkreide,  in  Germany ;  blanc  cfe  Troyes,  and 
Uanc  de  Meudon,  in  France.  Pure  chalk  should  dissolve  readily  in  dilute  muritaic  acid, 
and  the  solution  should  afford  no  precipitate  with  water  of  ammonia. 

CRKLYi-hlack.     A  mineral,  called  also  drawing-slate. 

CRXLK- French.     Steatite,  or  soap-stone ;  a  soft  magnesian  mineral. 

CHALK-re<i     A  clay   coloured   with  tlie  peroxide  of  iron,   of  which  it  contains 

about  17  per  cent.  ^ 

CHALYBEATE  is  the  name  given  in  medicine  to  preparations  of  iron.  The  most 
agreeable,  and  one  of  the  most  powerful,  forms  of  such  medicines,  is  the  improved 
chalybeate  water,  for  which  Mr.  Henry  Bewley,  apothecary  in  Dublin,  obtained  a 

I)atent  in  June,  1842.  The  following  is  his  valuable  recipe  -.—Eight  ounces  of  crystal- 
ized  citric  acid  being  dissolved  in  about  four  times  their  weight  of  water,  heated  to 
170<>  F.,  are  saturated  with  pure  peroxide  of  iron,  in  the  washed  state,  after  being 
precipitated  by  ammonia  from  the  ferric  sulphate.  The  solution  is  sweetened,  fla- 
voured, and  charged  highly  with  carbonic  acid  gas,  so  as  to  make  a  very  palatable 
potion,  agreeable  also  to  the  stomach. 

I  find  by  analysis  that  100  parts  of  Mr.  Bewley's  brilliant  citrate  of  iron  contain 
28-9  of  peroxide,  48  5  of  citric  acid,  and  23  of  water  ;  and  that  a  six-ounce  phial  of  his 
chalybeate  water  contains  of  that  citrate  a  quantity  equivalent  to  nearly  8  grains  of 

peroxide  of  iron. 

Similar  compounds  are  also  specified  to  be  made  with  other  organic  salts,  as  the 
tartrate  or  lactate  of  iron. — Newton's  Journal^  xxii.  470. 

CHAMELEON   MINERAL.      As   this   compound— so  long   known  in  chemistry 
as  a  mere  curiosity,  on  account  of  the  surprising  changes  of  color  which  it  spon- 
taneously assumes— has  of  late  been  largely  employed  for  whitenir?  tallow,  palm  oil, 
and   decoloring  other  organic  matters,  it  merits  description  in  this  dictionary.     It 
exists  in  two  states  ;  one  of  which  is  called  by  chemists  the  manganate  of  potash,  and 
the  other  the  oxymanganate;    denoting  that  the  first  is  a  compound  of  manganic  acid 
with  potash,  and  that  the  second  is  a  compound  of  oxymanganic  acid  with  the  same 
base.     They  are  both  prepared   in  nearly  the  same  way;   the  former  by  calcmmg 
together,  at  a  red  heat  in  a  covered  crucible,  a  mixture  of  one  part  of  the  black  per- 
oxide of  manganese  with  three  parts  of  the  hydrate  of  potash  (the  fused  potash  of  the 
apothecary).     The  mass  is  of  a  green  color  when  cold.     It  is  to  be  dissolved  in  cold 
water,  and  the  solution  allowed  to  settle,  and  become  clear,  but  by  no  means  filtered 
for  fear  of  the  decomposition  to  which  it  is  very  prone.    When  the  decanted  liquid  is 
evaporated  under  the  exhausted  receiver  of  an  air-pump,  over  a  surface  of  sulphuric 
acid,  it  afi'ords  crystals  of  a  beautiful  green  color,  which  should  be  laid  on  a  clean 
porous  brick  to  drain  and  dry.     They  may  be  preserved  in  dry  air,  but  should  be  kept 
in  a  well-corked  bottle.      They  are  decomposed  by  water,  but  dissolve  in  weak  water 
of  potash.      On   diluting  this  much,  decomposition  of  the  salt  ensues,  with  all  the 
chameleon  changes  of  tint ;  red,  blue,  and  violet.     Sometimes  a  green  solution  of  this 
salt  becomes  red   on   being  heated,  and  preserves  this  color   even  when  cold,  but 
resumes  its  green  hue  the  moment  it  is  shaken  :  it  might,  therefore,  furnish  the  crafty 
votaries  of  St.  Januarius  with  an  admirable  means  of  mystifying  the  worshippers  at  his 
shrine.     The  original  calcined  mass, in  being  dissolved,  always  deposites  a  considerable 
quantity  of  a  brown  powder,  which  is  a  compound  of  the  acid  and  peroxide  of  man- 
ganese combined  with  water.    Much  of  the  potash  remains  unchanged,  which  may  be 

recovered. 

The  oxymanganate  of  potash  is  made  by  fusing,  with  a  strong  heat,  a  mixture  of 
equal  parts  of  peroxide  of  manganese  and  hydrate  of  potash,  or  one  part  of  peroxide 
and  two  parts  of  nitre.  The  mass  is  to  be  dissolved  in  water,  and,  if  the  solution  be 
green,  it  should  be  reddened  by  the  cautious  addition  of  a  few  drops  of  nitric  acid. 
The  clarified  liquor  is  to  be  evaporated  to  the  point  of  crystallization.  Even  the 
smallest  crystals  of  this  salt  have  such  an  intense  red  color,  that  they  appear  black 
with  a  green  metallic  reflection.  In  the  air  they  gradually  assume  a  steel  gray  hue, 
without  undergoing  any  essential  change  of  nature.  A  very  little  of  the  salt  reddens 
a  lar^'e  body  of  water.  The  least  portion  of  any  organic  matter  added  to  the  solution 
of  this  salt  reduces  the  oxymanganic  acid  to  the  state  of  peroxide,  which  precipitates 
combined  with  water ;  and  the  liquor  becomes  green  or  colorless,  according  to  circum- 

A  more  permanent  oxymanganic  salt  may  be  made  as  follows  : — Melt  chlorate  of 
potash  over  a  spirit  lamp,  and  throw  into  it  a  few  pieces  of  hydrate  of  potash,  which 


CHARCOAL. 


397 


immediately  dissolve  and  form  a  Hmpid  liquid.     Whe^^^^^^^^ 
powder  is  ^adually  introduced  mto  ^"^^^ '^^^^^'^'f^l^'^^^^ 

when  boiled  assumes  a  fine  red  colour,  in  consequence  ol  its  ^^?f  ™'"^Hnir  and  still 
LnAtP  and  it  ought  to  be  decanted  off  the  sediment  while  hot.     By  cooling,  and  stm 

ment  rfoxygen!  a^nd  tlfe  destruction  of  many  vegetable  and  animal  eolour^  In  tto 
w«nPot  thev  resemble  the  nitrates  and  chlorates.  .  ^  j» 

rHARCOAL  The  fixed  residuum  of  vegetables  exposed  to  ignition  out  of  contact  of 
air  ^the  article  Carbon;  I  have  described  the  general  properties  of  charcoal  and  th^ 
S^plesl  mXof  mak'ng  it.    I  shaU  here  detail  the  best  systems  of  manufacturmg  thi. 

^'tcarTnize'^o^t?^^^ 

very  much  in  Germany.  The  wood  is  arranged  either  in  horizontal  layers,  or  innear^ 
I!rtJr«l  ones  with  a  sli-ht  slope,  so  as  to  form  conical  rounded  heaps  of  difl^errnt  sizes. 
The  foim^irrclire^^^^^^^^  339 ;  the  latter  standing  metier,  fi,s.  340  and  341. 

844  341 


Both  are  distributed  in  much  the  same  way. 

In  districts  where  the  wood  can  be  transported  into  one  place  by  means  of  rivers,  or 
mounSSera  Vflat  space  must  be  pitched  upon,  screened  from  storms  and  flood^ 
Xch  r^ay  be  walS  round,  having  a  slight  declivity  made  in  the  ground,  toward  the 
Tentre.  See  5ig.  342.  Into'  this  s^ace  the  tarry  acid  will  partially  fall,  and  may  be 
inducted  outward,  through  a  covered  gutter  beneath,  into  a  covered  tank  The 
mouth  of  the  tank  must  be  shut,  during  the  coaking,  with  an  iron  or  stone  slab,  luted 
wUh  clay.  A  square  iron  plate  is  placed  over  the  inner  orifice  of  the  gutter,  to  prevent 
Wiinciay.     a  S4"«  i  r  .it    being   choked  with    coal    ashes. 

Fig.  342  represents  a  walled  meiler 


station :     a,    the     station  ;     6, 


the 
gutter  ;  c,  the  tank,  which  is  cov- 
ered with  the  slab  d ;  e,  a  slab 
which   serves    to   keep    the    gutter 


dear  of  coals.  The  cover  of  the  heaps  is  formed  of  earth,  sand,  ashes,  or  such  other 
matter  as  may  be  most  readily  found  in  the  woods.  They  should  be  kindled  m  the  cen- 
tre From  6  days  to  4  weeks  may  be  required  for  charring  a  heap,  according  to  its  size ; 
hard  wood  requiring  most  time  ;  and  the  slower  the  process,  the  belter  and  greater  is  the 
product,  generally  speaking.        ^^^  ^^^^.^^     ^^    ^^^^     .^    ^^^^^^ 

(Hau/e  or  lie^ende  uerke),  figs.  343 
and  344,  difiers  from  that  in  the 
meiler,  because  the  wood  in  the 
haufe  is  successively  charred,  and 
the  charcoal  is  raked  out  by  little 
and  little.  The  product  is  said 
to  be  greater  in  this  way,  and  also 
better.  Uncleft  billets,  6  or  8 
feet  long,  being  laid  over  each 
other,  are  covered  with  ashes,  and 
then  carbonized.  The  station  is 
sometimes  horizontal,  and  some- 
times  made  to  slope.  The  length 
may  be  24  feet,  the  breadth  8 
feet :   and  the  wood  is  laid  crosa- 


398 


CHASCHISCH. 


wise.  Piles  are  set  perpendicularly  to  support  the  roof,  made  of  boughs  and  leaves, 
covered  with  ashes.  Pipes  are  occasionally  laid  within  the  upper  part  of  the  mounds, 
which  serve  to  catch  and  carry  off  some  of  the  liquid  products  into  proper  tanks. 

Fig.    345   is   a   vertical    section, 
345       „    .  fifO     and /g.  346,  a  half  bird's-eye  view, 

and  half  cross  section,  at  the  height 
of  the  pit-bottom,  of  Chabeaus- 
siere*s  kiln  for  making  wood  char- 
coal, o  is  the  oven;  b,  vertical 
air-pipes ;  c  c,  horizontal  flues  for 
admitting  air  to  the  kiln ;  d  d, 
small  pits  which  communicate  by 
short  horizontal  pipes  e  e,  with  the 
vertical  ones ;  /,  the  sole  of  the 
kiln,  a  circle  of  brickwork,  upon 
which  the  cover  or  iU»od  h  reposes; 
t,  a  pipe  which  leads  tc  the  cistern 
k ;  /,  the  pipe  destined  for  carrying 
off  the  gaseous  matter ;  m  m,  holes 
in  the  iron  cover  or  lid. 

The  distribution  of  the  wood  is 
like  that  in  the  horizontal  meikrsy 
or  heaps ;  it  is  kindled  in  the  cen- 
tral vertical  canal  with  burning 
fuel,  and  the  lid  is  covered  with 
a  few  inches  of  earth.  At  the  be- 
ginning of  the  operation  all  the 
draught  flues  are  left  open,  but 
they  are  progressively  closed,  as 
occasion  requires.  In  eight  kilns 
of  this  kind,  500  decasters  of  oak 
wood  are  carbonized,  from  which 
16,000  hectolitres  of  charcoal  are 
obtained,  equal  to  64,000  pounds 
French,  being  about  25  per  cent. ; 
besides  tar  and  3000  veils  of 
wood  vinegar,  of  from  2°  to  3* 
Baume. 

At  Crouy  upon  the  Ourcq,  near  Meaux,  there  is  a  well-constructed  kiln  for  making 
lurf-charcoal.     It  resembles  most  nearly  a  tar-kiln.     In^g.  347,  a  is  the  cylindrical 

coaking  place,  whose  surrounding  walls  are  heated  by 
the  flame  which  passes  through  the  intermediate  space 
b.  The  place  itself  is  divided  by  partitions  of  fife  tiles 
into  three  stages,  through  the  apertures  in  which  the 
flames  of  the  fire  c  c,  rise,  and  heat  the  exterior  of  the 
coaking  apartment.  In  order  to  confine  the  heat,  there 
is  in  the  enclosing  walls  of  the  outer  kiln  a  cylindrical 
hollow  space  d,  where  the  air  is  kept  stagnant.  Through 
the  apertures  left  in  the  upper  end  at  €,  the  turf  is  in- 
troduced ;  they  are  then  shut  with  an  iron  plate  /, 
which  is  covered  with  ashes  or  sand.  The  fire-place 
opens  above  this  aperture,  and  its  outlet  is  pro\'ided 
with  a  moveable  iron  cover  g,  in  which  there  is  a  small 
hole  for  the  issue  of  the  gases.  The  sole  of  the  kiln 
consists  of  a  cast  iron  slab  A,  which  may  be  raised  by 
means  of  a  hook  t  upon  it.  This  is  drawn  back  after 
the  carbonization  is  completed,  whereby  the  charcoal 
fulls  from  the  coaking  space  into  a  subjacent  vault.  The 
volatile  products  are  carried  off  by  the  pipe  k,  and  led 
into  the  condensing  cistern  ;  the  gases  escaping  to  the 
fire-place  where  they  are  burned.  The  iron  slab  is  protected  from  the  corrosion  of  the 
acid  vapors  by  a  layer  of  coal  ashes. 

CHASCHISCH.  Hadschy  is  not  the  correct  term  for  this  narcotic  drug,  for  Iladschy 
means  a  pilgrim  ;  the  true  name  is,  according  to  pronunciation,  Chaschisch,  the  Arab 
word  for  hemp  (Cannabis  saliva).  By  this  name  all  intoxicating  drugs,  whose  chief 
constituent  is  this  herb,  are  well  known  over  the  whole  of  the  East  The  mode  of 
preparing  chaschisch  is  the  following: — 


CHIMNEY. 


399 


The  tops  and  all  the  tender  parta  of  the  hemp  plant  are  collected  aft^er  the  period  of 
inflorescence,  dried  and  kept  for  use.  It  must  be  premised  that  the  hemp  plant  is  in 
the  East  distinguished  by  its  narcotic  properties,  although  botanists  are  unable  to  detect 
any  diflference  between  this  and  the  European  species.     The  dried  hemp,  or  chaschisch, 

Ist  foiled  in  fat,  butter,  or  oil,  with  a  little  water ;  the  filtered  product  is  employed 

in  all  kinds  of  pastry.  ,    ^  r 

2nd.  Powdered  for  smoking :  5  or  10  grs.  of  the  powder  are  smoked  from  a  common 
pipe  (tmbuk)  with  ordinary  tobacco  {tutwn),  or  from  a  water  pipe  {nargide)  with 
another  kind  of  tobacco  {tombeki).  Tlie  torabeki  is  probably  the  leaf  of  a  species  of 
Lobelia;  it  is  smoked  in  a  nargiele,  and  is  uncommonly  nareoctic ;  so  much  so,  tliat 
it  is  ordinarily  steeped  in  water  for  a  few  hours  before  it  is  used  to  weaken  it,  and  the 
pipe  is  charged  with  it  whilst  it  is  yet  wet 

3rd.  Formed  with  tragacanth  mucilage  into  pastiles,  which  are  placed  upon  a  pipe 
and  smoked  in  similar  doses.  These  two  last  preparations  are  so  termed  esrar  {esrar 
is  the  Arab  word  for  "  secret") ;  they  are  the  most  active  of  all  the  preparations  of 
chaschisch,  and  the  first  pipe  will  cause  cerebral  congestion  in  beginners. 

4th  Made  into  an  electuary  with  dates  or  figs  and  honey.  This  preparation  is  of 
a  dark  brown,  almost  black,  colour,  and  tastes  of  dates  and  hemp ;  it  is  less  active  than 
tjnf^  fisrftr 

5th.  Lastly,  another  electuary  is  prepared  of  the  same  ingredients  with  the  addition 
of  spices,  clove,  cinnamon,  pepper,  amber,  and  musk.    This  preparation  is  used  as  an 

aphrodisaic.  ,  .       *•*•*• 

Chaschisch  is  said  not  to  produce  stupor  but  the  most  pleasant  species  of  intoxication. 
The  person  under  its  influence  feels  with  perfect  consciousness  m  the  best  of  all 
humours;  all  impressions  from  without  produce  the  most  grateful  sensations;  pleasant 
illusions  pass  before  his  eyes,  and  he  feels  comfortably  happy;  he  thinks  himselt  the 
happiest  man  on  earth,  and  the  world  appears  to  him  Paradise.  From  this  imaginative 
state  he  parses  into  the  every  day  state,  with  a  perfect  recollection  of  all  sensations,  and 
of  every  thing  he  has  done  and  of  every  word  he  has  spoken.  The  effects  ot  a  con- 
tinued use  of  Ihe  narcotic  are  emaciation  and  nervous  debility. 

CIIEPiSE  {composiMon  of).  Cheese  of  certain  dairies  and  districts  is  apt  to  undergo 
a  remarkable  decomposition  whereby  valerianic  acid  is  formed.  Messrs.  Jljenko  and 
Laskowsi  distilled  along  with  water  a  turbid  ammoniacal  liquor,  which  being  redistilled 
along  with  some  sulphuric  acid,  and  the  product  neutralized  by  barytes,  the  resulting 
saline  compound  proved  to  be  the  valerianate  of  that  base,  mixed  with  compounds  ot 
butyric  acid,  caproic  acid,  eaprylic  acid,  and  capric  acid.  The  cheese  was  from  Limbourg. 
Valerianic  acid  was  found  by  M.  Balard  in  the  cheese  of  Roquefort 

CHICA  is  a  red  colouring  principle  made  use  of  in  America  by  son;e  Indian  tribes 
to  stain  their  skins.  It  is  extracted  from  the  bignonia  chica  by  boiling  its  leaves  in 
water,  decanting  the  decoction,  and  allowing  it  to  settle  and  cool,  when  a  red  matter 
falls  down,  which  is  formed  into  cakes  and  dried.  This  substance  is  not  fusible,  and, 
when  burned,  diffuses  the  same  odor  as  animal  bodies  do.  t  is  insoluble  in  cold  water, 
very  soluble  in  alcohol  and  ether,  but  after  the  evaporation  of  these  liquids,  it  is  recovered 
unchansed.  Fats  and  unctuous  oils  both  dissolve  it.  It  is  soluble  in  carbonated  and  caus- 
tic alkaline  leys,  from  which  it  is  precipitated  by  the  acids  without  alteration.  An  excess 
of  alkali,  however,  speedily  decomposes  it.  Nitric  acid  transforms  it  into  oxalic  acid,  and 
a  bitter  matter.     Chlorine  makes  it  white.  ,     k  • 

The  savages  mix  this  pigment  with  the  fat  of  the  cayman  or  alligator,  and  rub  their 
skins  with  the  mixture.      It  may  probably  be  turned  to  account  in  the  arts  of  civilized 

nations.  .  ,        .         ,. 

CHIMNEY.  (C/icmtWe,  Fr.;  Sc/lonw/ciTJ,  Germ.)  Chimney  is  a  modern  invention 
for  promoting  the  draught  of  fires  and  carrying  off  the  smoke,  introduced  into  England 
so  late  as  the  age  of  Elizabfath,  though  it  seems  to  have  been  employed  in  Italy  100 
years  before.  The  Romans,  with  all  their  luxurious  refinements,  must  have  had  their 
Epicurean  cookery  placed  in  perpetual  jeopardy  from  their  kitchen  fires,  which,  having  no 
vent  by  a  vertical  tunnel  in  the  walls,  discharged  their  smoke  and  frequently  their  flames 
at  the  windows,  to  the  no  small  alarm  of  their  neighbors,  and  annoyance  of  even  the 

street  passengers.  i  u  •     . 

Chimneys  in  dwelling  houses  serve  also  the  valuable  purpose  of  promoting  salubrious 
circulation  of  air  in  the' apartments,  when  not  foolishly  sealed  with  anti-ventilating  stove- 
chests.  J        , 

The  first  person  who  sought  to  investigate  the  general  principles  of  chimney  drausnis, 
in  subserviency  to  manufacturing  establishments,  was  the  celebrated  Montgolfier.  As  the 
ascent  of  heated  air  in  a  conduit  depends  upon  the  diminution  of  its  specific  gravity,  or, 
in  other  words,  upon  the  increase  of  its  volume  by  the  heat,  the  ascensional  force  may 
we  deduced  from  the  difference  between  the  density  of  the  elastic  fluid  in  the  mterior  of 


400 


CHIMNEY. 


*he  chimney,  and  of  the  external  air ;  that  is,  between  the  different  heights  of  the  interna] 
and  external  columns  of  elastic  fluid  supposed  to  be  reduced  to  the  same  density.  In  the 
latter  case,  the  velocity  of  the  gaseous  products  of  combustion  in  the  interior  of  the  chim- 
ney is  equal  to  that  of  a  heavy  body  let  fail  from  a  height  equal  to  the  difference  in  height 
of  the  two  aerial  columns. 

To  illustrate  this  position  by  an  example,  let  us  consider  the  simple  case  of  a  chimney 
of  ventilation  for  carrying  off  foul  air  from  a  factory  of  any  kind ;  and  suppose  that 
the  tunnel  of  iron  be  incased  throughout  with  steam  at  212  degrees  Fahr.  Suppose  this 
tunnel  to  be  100  yards  high,  then  the  weight  of  the  column  of  air  in  it  will  be  to  that  of 
a  column  of  external  air  100  yards  high,  assumed  at  32?  F.,  inversely  as  its  expansion  by 
180® ;  that  is,  as  1000  is  to  1-375;  or  as  72*727  is  to  100.  The  column  of  external  air 
at  32°  being  100  yards,  the  internal  column  will  be  represented  by  72*727  ;  and  the  dif- 
ference=27*27,  will  be  the  amount  of  unbalanced  weight  or  pressure,  which  is  the  effec- 
tive cause  of  the  ventilation.  Calculating  the  velocity  of  current  due  to  this  difference  of 
weight  by  the  well-known  formula  for  the  fall  of  heavy  bodies,  that  is  to  say,  multiplying 
the  above  difference,  which  is  27*27,  by  the  constant  factor  19.62,  and  extracting  the 

square  root  of  the  product ;  thus  V  19*62  X  27*27  =  23*13  will  be  the  velocity  in  yards 
per  second,  which,  multiplied  by  3,  gives  60*30  feet.  The  quantity  of  air  which  passes 
in  a  second  is  obtained  of  course  by  multiplying  the  area  or  cross  section  of  the  tunnel  by 
this  velocity.  If  that  section  is  half  a  yard,  that  is  =  a  quadrangle  2|  feet  by  2,  we  shall 
have  23*13  X  0*5  =  11*565  cubic  yards,  =  312^  cubic  feet. 

The  problem  becomes  a  little  more  complicated  in  calculating  the  velocity  of  air  which 
has  served  for  combustion,  because  it  has  changed  its  nature,  a  variable  proportion  of  its 
oxygen  gas  of  specific  gravity  1*111,  being  converted  into  carbonic  acid  gas  of  specific 
gravity  1*524.  The  quantity  of  air  passed  through  well  constructed  furnaces  may,  in 
general,  be  regarded  as  double  of  what  is  rigorously  necessary  for  combustion,  and  the 
proportion  of  carbonic  acid  generated,  therefore,  not  one  half  of  what  it  would  be  were 
all  the  oxygen  so  combined.  The  increase  of  weight  in  such  burned  air  of  the  temperature 
of  212?,  over  that  of  pure  air  equally  heated,  being  taken  into  account  in  the  preceding 
calculation,  will  give  us  about  19  yards  or  57  feet  per  second  for  the  velocity  in  a  chim> 
ney  100  yards  high  incased  in  steam. 

Such  are  the  deductions  of  theory ;  but  they  differ  considerably  from  practical  results, 
in  consequence  of  the  friction  of  the  air  upon  the  sides  of  the  chimneys,  which  varies  like- 
wise with  its  form,  length,  and  quality.  The  direction  and  force  of  the  winds  also  exercise 
a  variable  influence  upon  chimney  furnaces  differently  situated.  In  chimneys  made  of 
wrought  i'X)n,  like  those  of  steamboats,  the  refrigeration  is  considerable,  and  causes  a 
diminution  of  velocity  far  greater  than  what  occurs  in  a  factory  stalk  of  well  built  brick 
work.  In  comparing  the  numbers  resulting  from  the  trials  made  on  chimneys  of  dif- 
ferent materials  and  of  different  forms,  it  has  been  concluded  that  the  obstruction  to  the 
draught  of  the  air,  or  the  deduction  to  be  made  from  the  theoretical  velocity  of  efflux, 
is  directly  proportional  to  the  length  of  the  chimneys  and  to  the  square  of  the  velocity, 
and  inversely  to  their  diameter.  With  an  ordinary  wrought-iron  pipe,  of  from  4  inches 
to  D  inches  diametei,  attached  to  an  ordinary  stove,  burning  good  charcoal,  the  difference 
b  prodigious  between  the  velocity  calculated  by  the  above  theoretical  rule,  and  that  ob- 
served by  means  of  a  stop-watch,  and  the  ascent  of  a  puff  of  smoke  from  a  little  tow, 
dipped  in  oil  of  turpentine  thrust  quickly  into  the  fire.  The  chimney  being  45  feet 
high,  the  temperature  of  the  atmosphere  68°  Fahr.,  the  velocity  per  second  was,  — 

Mean  temperature 
Trials.  By  theory.  By  experiment,  of  chimney. 

1  26.4  feet  5       feet  190°  Fahr. 

2  29*4  5-76  214 

3  34*5  6*3  270 

To  obtain  congruity  between  calculation  and  experiment,  several  circumstances  must 
be  introduced  into  odr  formula.  In  the  first  place,  the  theoretical  velocity  must  be 
multiplied  by  a  factor,  which  is  different  according  as  the  chimney  is  made  of  bricks, 
pottery,  sheet  iron,  or  cast  iron.  This  factor  must  be  multiplied  by  the  square  root  of 
the  diameter  of  the  chimney  (supposed  to  be  round),  divided  by  its  length,  increased  by 


four  times  its  diameter.    Thus,  for  pottery,  its  expression  is  2*06  V 


D 


L-j-D 


;  D  being  the  di- 


ameter, and  L  the  length  of  the  chimney. 

A  pottery  chimney,  33  feel  high,  and  7  inches  in  diameter,  when  the  excess  of  its  mean 
temperature  above  that  of  the  atmosphere  was  205°  Fahr.,  had  a  pressure  of  hot  air 
equal  to  11*7  feet,  and  a  velocity  of  7*2  feet  per  second.  By  calculating  from  the  last 
fonnul&j  ihe  same  number  very  nearly  is  obtained.  In  none  of  the  experiments  did  the 
velocity  exceed  12  feet  per  second,  when  the  difference  of  temperature  was  more  than 
410°  Fahr. 


CfflMNEY. 


401 


Every  different  form  of  chimney  would  require  a  special  set  of  experiments  to  be 
made  for  determining  the  proper  factor  to  be  used. 

This  troublesome  operation  may  be  saved  by  the  judicious  application  of  a  delicate 
differential  barometer,  such  as  that  invented  by  Dr.  Wollaston ;  though  this  instrument 
does  not  seem  to  have  been  applied  by  its  very  ingenious  author  in  measuring  the 
draughts  or  ventilating  powers  of  furnaces. 

If  into  one  leg  of  this  differential  syphon  water  be  put,  and  fine  spermaceti  oil  into 
the  other,  we  shall  have  two  liquids,  which  are  to  each  other  in  density  as  the  numbers 
8  and  7.  If  proof  spirit  be  employed  instead  of  water,  we  shall  then  have  the  relation 
of  very  nearly  20  to  19.  I  have  made  experiments  on  furnace  draughts  with  the  instrument 
in  each  of  these  slates,  and  find  the  water  and  oil  syphon  to  be  sufficiently  sensible ;  for 
the  weaker  draughts  of  common  fire-places  the  spirits  and  oil  will  be  preferable 
barometric  fluids. 

To  the  lateral  projecting  tube  of  the  instrument,  as  described  by  Dr.  Wollaston,  I 
found  it  necessary  to  attach  a  stop-cock,  in  order  to  cut  off  the  action  of  the  chimney, 
while  placing  the  syphon,  to  allow  of  its  being  fixed  in  a  proper  state  of  adjustment, 
with  its  junction  line  of  the  oil  and  water  at  the  zero  of  the  scale.  Since  a  slight  de- 
viation of  the  legs  of  the  syphon  from  the  perpendicular  changes  very  considerably  the 
line  of  the  level,  this  adjustment  should  be  made  secure  by  fixing  the  horizontal  pipe 
tightly  into  a  round  hole,  bored  into  the  chimney  stalk,  or  drilled  through  the  furnace 
door.  On  gently  turning  the  stop-cock,  the  difference  of  atmospherical  pressure  cor- 
responding to  the  chimney  draught,  will  be  immediately  indicated  by  the  ascent  of  the 
junction  line  of  the  liquids  in  the  syphon.  This  modification  of  apparatus  permits  the 
experiment  to  be  readily  rectified  by  again  shutting  off  the  draught,  when  the  air  will 
slowly  re-enter  the  syphon ;  because  the  projecting  tube  of  the  barometer  is  thrust  into 
the  stop-cock,  but  not  hermetically* joined ;  whereby  its  junction  line  is  allowed  to  retom 
to  the  zero  of  the  scale  in  the  course  of  a  few  seconds. 

Out  of  many  experiments  made  with  this  instrument,  I  shall  content  myself  with 
describing  a  few,  very  carefully  performed  at  the  breweries  of  Messrs.  Trueman,  Han- 
bury,  and  Buxton,  and  of  Sir  H.  Meux,  Bart.,  and  at  the  machine  factory  of  Messrs. 
Braithwaite ;  in  the  latter  of  which  I  was  assisted  by  Captain  Ericsson.  In  the  first 
trials  at  the  breweries,  the  end  of  the  stop-cock  attached  to  the  differential  barometer 
was  lapped  round  with  hemp,  and  made  fast  into  the  circular  peep-hole  of  the  furnace 
door  of  a  wort  copper,  communicating  with  two  upright  parallel  chimneys,  each  18  inches 
square  and  50  feet  high.  The  fire  was  burning  with  fully  its  average  intensity  at  the 
time.  The  adjustment  of  the  level  being  perfect,  the  stop-cock  orifice  was  opened,  and 
the  junction  level  of  the  oil  and  water  rose  steadily,  and  stood  at  1^  inches,  corresponding 
to  ii2  5.  —  0-156  of  1  inch  of  water,  or  a  column  of  air  10*7  feet  high.     This  difference 

of  pressure  indicates  a  velocity  of  26  feet  per  second.  In  a  second  set  of  experiments, 
the  extremity  of  the  stop-cock  was  inserted  into  a  hole,  bored  through  the  chimney 
stalk  of  the  boiler  of  a  Boulton  and  Walt  steam-engine  of  twenty-horse  power.  The 
area  of  this  chimney  was  exactly  18  inches  square  at  the  level  of  the  bored  hole,  and  its 
summit  rose  50  feet  above  it.  The  fire-grate  was  about  10  feet  below  that  level.  On 
opening  the  stop-cock,  the  junction  line  rose  2^  inches.  This  experiment  was  verified 
by  repetition  upon  difl'erent  days,  with  fires  burning  at  their  average  intensity,  and  con- 
suming fully  12  lbs.  of  the  best  coals  hourly  for  each  horse's  power,  or  nearly  one  ton 
and  a  third  in  twelve  hours.  If  we  divide  the  number  2|  by  8,  the  quotient  0*28  will 
represent  the  fractional  part  of  1  inch  of  water,  supported  in  the  syphon  by  the  un- 
balanced pressure  of  the  atmosphere  in  the  said  chimney;  which  corresponds  to  19J  feet 
of  air,  and  indicates  a  velocity  in  the  chimney  current  of  35  feet  per  second.  The 
consumption  of  fuel  was  much  more  considerable  in  the  immense  grate  under  the  wort 
copper,  than  it  was  under  thoi steam-engine  boiler. 

In  my  experiments  at  Messrs.  Braithwaite's  factory,  the  maximum  displacement  of 
the  junction  line  was  1  inch,  when  the  differential  oil  and  water  barometer  was  placed 
in  direct  communication  with  a  chimney  15  inches  square,  belonging  to  a  steam  boiler, 
and  when  the  fire  was  made  to  burn  so  fiercely,  that  on  opening  the  safety-valve  of  the 
boiler,  the  excess  of  steam  beyond  the  consumption  of  the  engine  rushed  out  with  such 
violence  as  to  fill  the  whole  premises.  The  pressure  of  one  eighth  of  an  inch  of  water 
denotes  a  velocity  of  draught  of  23*4  feet  per  second. 

In  building  chimneys,  we  should  be  careful  to  make  their  area  rather  too  large  than 
too  small ;  because  we  can  readily  reduce  it  to  any  desired  size,  by  means  of  a  sliding 
register  plate  near  its  bottom,  or  a  damper  plate  applied  to  its  top,  adjustable  by  wires 
or  chains,  passing  over  pulleys.  Wide  chimneys  are  not  so  liable  as  narrow  ones  to 
have  their  draught  affected  by  strong  winds.  In  a  factory,  many  furnace  flues  are 
often  conducted  into  one  vertical  chimney  stalk,  with  great  economy  in  the  first 
erection,  and  increased  power  of  draught  in  the  several  fires. 

Vast  improvements  have  been  made  in  this  country,  of  late  years,  in  building  stalks 

Vol.  I.  3  F 


409 


CfflMNEY. 


for  steam  boilers  and  chemical  furnaces.  Instead  of  constructing  an  expansive,  bay 
scaffolding  of  timber  round  the  chimney,  for  the  bricklayers  to  stand  upon,  and  to 
place  their  materials,  pigeon-holes,  or  recesses,  are  left  at  regular  intervals,  a  lew  leet 
apart,  within  the  chimney,  for  receiving  the  ends  of  stout  wooden  bars,  which  are 
laid  across,  so  as  to  form  a  species  of  temporary  ladder  in  the  interior  of  the  tunnel. 
Py  means  of  these  bars,  with  the  aid  of  ropes  and  pulleys,  everything  may  be  pro- 
eressively  hoisted,  for  the  building  of  ihe  highest  engine  or  other  stalks.  An  expert 
bricklayer,  wiih  a  handy  laborer,  can  in  this  way  raise,  in  a  few  weeks,  a  considerable 
chimney  40  feet  high,  5  feet  8  inches  square  outside,  2  feet  8  inches  inside  at  the  base, 
28  inches  outside,  and  20  inches  inside  at  the  top.  To  faciUtate  the  erection,  and  at 
the  same  time  increase  the  solidity  of  an  insulated  stalk  of  this  kmd,  it  is  buut 
with  three  or  more  successive  plinths,  or  recedures,  as  shown  in  fig.  281.  It  is  neces- 
sary to  make  such  chimneys  thick  and  substantial  near  the  base,  in  order  that  they 
may  sustain  the  first  violence  of  the  fire,  and  prevent  the  sudden  dissipation  of  the 
heat.  When  many  flues  are  conducted  into  one  chimney  stalk,  the  area  of  the  latter 
should  be  nearly  equal  to  the  sum  of  the  areas  of  the  former,  or  at  least  of  as  many  of 
them  as  shall  be  going  simultaneously.  When  the  products  of  combustion  from  any 
furnace  must  be  conducted  downwards,  in  order  to  enter  near  the  bottom  of  the  main 
stalk,  they  will  not  flow  off  until  the  lowest  part  of  the  channel  be  heated  by  burning 
9ome  wood  shavings  or  straw  in  it,  whereby  the  air  syphon  is  set  agoing.  Immedi- 
ately after  kindling  this  transient  fire  at  that  spot,  the  orifice  must  be  shut  by  which 
it  was  introduced ;  otherwise  the  draught  of  the  furnace  would  be  seriously  impeded. 
But  this  precaution  is  seldom  necessary  in  great  factories,  where  a  certain  degree  of  heat 
is  always  maintained  in  the  flues,  or,  at  least,  should  be  preserved,  by  shutting  the 
damper  plate  of  each  separate  flue,  whenever  its  own  furnace  ceases  to  act.  Such  chim- 
neys are  finished  at  top  with  a  coping  of  stone-slabs,  to  secure  their  brickwork  against 
the  infiltration  of  rains,  and  they  should  be  furnished  with  metallic  conducting  rods,  to 
protect  them  from  explosions  of  lightning.  _ 

When  small   domestic   stoves   are   used,  with   very  slow  combustion,  as  has  been 
recently  proposed,  upon  the  score  of  a  misjudged  economy,  there  is  great  danger  of  the 
inmates  bein?  suffocated  or  asphyxied,  by  the  regurgitation  of  the  noxious  burned  air. 
The  smoke  doctors  who  recommend   such  a  vicious  plan,  from  their  ignorance  ot 
chemical  science,  are  not  aware  that  the  carbonic  acid  gas,  of  coke  or  coal,  must  be  heated 
250°  F.  above  the  atmospheric  air,  to  acquire  the  same  low  specific  gravity  with  it.     In 
other  words,  unless  so  rarefied  by  heat,  that  gaseous  poison  will  descend  through  the  onfic« 
of  the  a^h-pit,  and  be  replaced  by  the  lishter  air  of  the  apartment.      Drs.  Priestley  and 
Dalton  have  long  ago  shown  the  co-existence  of  these  two-fold  crossing  currents  of  air, 
even  through  the  substance  of  stone-ware  tubes.      True  economy  of  heat,  and  salubrity, 
alike  require  vivid  combustion  of  the  fuel,  with  a  somewhat  brisk  draught  inside  of  the 
chimney,   and  a  corresponding  abstraction  of  air  from   the  apartment.      Wholesome 
continuous  ventilation,  under  the  ordinary  circumstances  of  dwelling  houses,  cannol 
be  secured  in  any  other  way.      Were  these  mephitic  stoves,  which  have  been  of  late 
so  ridiculously  puffed  in  the  public    prints,   generally  introduced,  the   faculty  would 
need  to  be  immediately  quadrupled  to  supply  the  demand  for  medical  advice ;    for 
headaches,  sickness,  nervous  aliments,  and  apoplexy,  would  become  the  constant  inmates 
of  every  inhabited  mansion.     The  phenomena  of  the  grotto  of  Pausilippo  might  then 
be  daily  realised  at  home,  among  those  who  ventured  to  recline  upon  solas  in  such  car- 
bonated apartments ;  only  instead  of  a  puppy  being  suffocatedpro  tctnpore,  human  beings 
would  be  sacrificed,  to  save  two  penny  worth  of  fuel  per  diein. 

The  figures  upon  the  following  page  represent  one  of  the  two  chimneys,  recently 
erected  at  the  Camden  Town  station,  for  the  steam  boilers  of  the  two  engines  of  60 
horse-power  each,  belonging  to  the  London  and  Bimingham  Railway  company.  Ihew 
engines  then  drew  their  train  of  carriages  up  the  inclined  plane  of  Hampstead  HilL 
The  chimneys  were  designed  by  Robert  Stephenson,  Esq.,  engineer  to  the  Company, 
executed  by  William  Cubitt,  Esq,  of  Gray's  Inn  road,  -  and  do  equal  honour  to 
both  gentlemen,  being  probably  among  the  most  elegant  and  substantial  specimens  ol 
this  style  of  architecture  in  the  world.     In  the  section, /^r.  348., 

A  represents  a  bed  of  concrete,  6  feet  thick,  and  24  feet  square. 

B,  brick  footings  set  in  cement;  the  lower  course  19  feet  square. 

c!  Bramlev-fall  stone  base,  with  a  chain  of  wrought  iron  let  into  it 

D,  a  portion,  15  feet  high,  curved  to  a  radius  of  113  feet»  buUt  entirely  of  Malm 
paviours,  (a  peculiarly  good  kind  of  bricks). 

E,  shaft  built  of  Malm  paviours  in  mortar. 

F  ditto,  built  from  the  inside,  without  exterior  scaffolding.  ,      ,    ^         ^, 

6,  the  cap  ornamented,  (as  shown  in  the  plan  alongside,)  with  Portland  stone,  the 
dressings  being  tied  together  with  copper  cramps  and  an  iron  bond. 
Fiq.  349.  represents  the  mouldings  of  the  top,  upon  an  enlarged  scale. 


CHINA  INK. 

Fig.  360,  a  plan  of  the  foundation,  upon  an  enlarged  scale. 
Fig.  361,  ditto,  at  the  level  of  the  entrance  of  the  flue,  as  seen 
Fig.  362.,  the  elevation  of  the  chimney. 
Fig.  363.,  plan  at  the  ground  level  i,  in  /^.  348.  and  862. 
K^fig.  348.,  the  lightning  conducting  roi 

.349  862 


m 


848 


4oe 


CHINA  INK.  {Eru^e  de  Cldne,  Fr. ;  Chinesischer  Tusch,  Germ.)  The  finest 
kind  of  this  useful  pigment  is  seldom  met  with  in  our  markets.  According  to  a  de- 
scription in  a  Japanese  book,  it  is  made  from  the  condensed  smoke  or  soot  of  burned 
camphor ;  and  hence,  when  of  the  best  quality,  it  has  this  odour.    Most  of  the  CSiina 

8  F2 


4(^4 


CHLORATE  OF  POTASH. 


CHLORATE  OF  POTASH. 


405 


ink  is  made  from  oil-lampblack  occasionally  disguised  as  to  smell,  with  mus^  or 
^th  a  Httt  camphor  blacS.     The  binding  substance  is  gelatine  commonly  ma^^^^  in>m 
parchment  or  as^'  skin;  but  isinglass  answers  eciually  ^^11.     A  good  imita^^^^^^^ 
L  made  by  dissolving  isinglass  m  warm  water,  with  ^^^  ^^^^t.  ?,^.f  .^^^i^^j^^^^^ 
f sodal  to  destroy  its  gelatinizing  power ;  and  meorporatmg  with  that  solution,  by  levi 
latioi  on  a  porphyry  slab,  as  much  of  the  finest  fampblack  as  to  produce  a  mass  o 
fhe  DroDer  cfusktence.     The  minute  quantity  of  alkali  serves  also  to  saponify  the  oil 
whicruTualTy  a^^^^^^^^^^      lampblack;  Ind  thereby  to  make  a  pigment  readily  miscible 

^CHINTZ  is  a  peculiar  style  of  fast-printed  calico,  in  which  figures  of  at  least  five 
diflFerent  colours  are  impressed  upon  a  white  or  light  coloured  ^^^^^^'  .  ..,,,ji„^ 

CHLORATE  OF  POTASH,  commonly  called  oxymunate  of  potash,  inis  mieresung 
•aline  compound  has  become  the  object  of  a  pretty  extensive  ^^^'^J^l^'^'^'f  ^""^^^^^Jl^l 
of  its  application  to  make  matches  for  procuring  instantaneous  light,  and  a  detonating 
nowder  for  fire-arms.     It  may  be  prepared  both  in  the  humid  and  dry  way.  ...    -   _ 

Having  made  a  strong  solution  of  purified  potash,  or  carbonate  of  potash,  with  Irom 
two  to  three  parts  of  water,  we  pass  through  it  in  a  Woulfe's  apparatus  a  current  of  ch  o- 
rine  gas;  tni  it  ceases  to  absorb  any  more.     Chloride  of  potash  and  chloride  of  potassium 
SoXe  formed  as  long  as  there  is  an  excess  of  alkali  in  the  ^ol^^^^V'  ^"V"  .'iwtp' 
in  the  further  reaction  of  the  materials,  the  chloride  passes  mto  the  state  of  a  chlorate, 
and  L  such!  precipitates  from  the  solution.    During  the  first  half  of  the  operation,  that 
S^  tilHhe  A^h  be  about  one  half  saturated  with  chlorine,  as  indicated  by  litmus  paper 
^s  ng  toC  darkened  and  beginning  to  be  blanched,  only  the  chloride  of  Potassium  or 
S^Lte  of  potash  falls.     The  process  should  be  interrupted  at  this  pomt  in  o^d^r  U>  re- 
S^fthe  salt,  to  wash  it,  to  add  the  washings  to  the  liquor,  and  t^en  to  transmit  the  gj^S 
freely  through  the  solution.    As  the  operation  advances  less  muriate  ^^^i'^^'l^^J'^^; 
and  at  length  nothing  but  the  pure  chlorate  is  separated  in  crystals.    When  finally  the 
SSbbles  of  gas  pass  through  without  being  sensibly  absorbed,  the  process  is  known  to  be 
Seted ;  the  liquid  ma?  then  be  allowed  to  settle,  and  be  poured  ofi"  from  l^^e  crystids 
Sora?e  of  potash,  which  are  purified  from  the  muriate  by  disso  vmg  them  m  three 
SmTtheVr  we^^t  of  boiling  water,  and  filtering  the  solution  wh.lr  hot      On  its  coolmg, 
th^ch  orate  will  separate  in  pearly-looking  crystalline  plates,     li  may  be  rendered  qu.te 
mire  by  a  second  c^stallization,  in  which  stite  it  does  not  affect  solution  of  nitrate  of  silver. 
The  ab^ve  potaS  ley  usually  gets  a  reddish  tint  in  the  course  of  the  process  in  conse- 
Q Jnce  of  ImUe  1^^^^^  acid  coming  over  wi,h  the  chlorine,  but  ,t  gradually  loses 

^  color  as  the  saturation  becomes  complete,  when  the  s?l»tion  turns  .yellow.    The 
tubes  for  conveying  the  gas  should  be  of  large  diameter,  if  they  be  plunged    nto  the 
S^eS^ur,  because  tfe  ciystallization  which  takes  place  in  it  is  apt  to ^ 
wT  This  inconvenience  may  however  be  obviated  by  attaching  to  the  end  of  the  glass 
rube  a  tube  of  caoitchouc  terminated  in  a  small  glass  funnel,  or  sunply  the  neck  of  a 
caoutchouc  b^  tie  with  a  pan  of  its  body,  whose  width  will  not  be  readily  closed  with  a 
salTne  crust     The  residuary  lixivium  may  be  used  against  ano  her  operation,  or  it  may 
S  evaporated  down  to  hJf  its  bulk  and  set  aside  to  crystallize,  whereby  some  more 
chSwUl  be  obtained,  mixed  indeed  with  muriate  and  carbonate,  from  which  however 
it  marbrseparated  by  k  second  crystallization.    In  general  the  pure  chlorate  obtained 
doS  not  exceed  one  tenth  the  weight  of  the  potash  employed  ;   because  in  thus  treating 
n^tLrw'S  chloiin^^^^^^    sixths  of  it  are  converted  into  muriate  of  potash  and  only  one 
Sh  mrchlorate,  aid  a  part  of  the  latter  adheres  to  the  muriate,  or  is  lost  in  the  mother 

waters  of  the  crystaUizations.  r    .       i  i:>,«  «Vo»  «r  ilmP  in 

The  chlorate  of  potash  may  be  more  conveniently  manufactured  like  that  of  lime    n 
the  d'y  way.     St.  Romer  patented  at  Vienna  the  following  method  for  that  PyPO  «  J^ 
1821  -—Ten  pounds  of  crystallized  peroxyde  of  manganese  are  to  be  finely  P"Jye"zed» 
^ei  with  ten'pounds  of  plumbago,  and  thirty  pounds  of  common  salt  ar.d  P"t  »nto  the 
leaden  retort  represented  in  fig.  287,  p.  293.     From  the  middle  of  the  helmet-shaped 
hd  of  this  vessel,  a  lead  tube,  two  feet  long,  and  two  inches  wide,  conducts  to  the  receiver, 
which  is  a  square  earthen  pan,  hard  glazed  both  within  and  without,  of  the  same  capacity 
with  the  retort.    The  end  of  the  tube  must  be  made  fast  to  a  frame  at  the  height  of  six 
inches  above  the  bottom  of  the  receiver.  Upon  its  inner  sides,  four  inches  apart,  brackets 
•re  to  be  fixed  for  supporting  a  series  of  laths  or  shelves  of  white  wood,  on  which  a  num- 
Lr  of  little  paper  or  pasteboard  boxes  are  to  be  laid.     In  these  boxes  ten  pounds  of  the 
n^rei  carbonate  of  potash,  prepared  from  tartar,  are  to  be  spread.     The  receiver  must 
now  be  covered  with  a  lid  made  tight  by  a  water  lute.    Twenty  pounds  of  concentrated 
sulphuric  acid  previously  diluted  with  sixteen  pounds  of  water,  and  then  cooled,  are  to 
b^  poured  upon  the  mixed  materials  in  the  retort,  the  lid  immediately  secured,  with  the 
tube  adiusted  in  the  receiver.  The  whole  must  be  allowed  to  operate  spontaneously  with- 
ouVheat  for  twelve  hours.     At  the  end  of  this  time  the  retort  is  to  be  surrounded  with  a 
water  bath  and  steadUy  heated  during  twelve  hours,  and  then  left  to  cool  for  six  hours. 


The  apparatus  must  now  be  opened,  the  cakes  of  chlorate  of  potash  removed,  and  freed 
from  muriate  by  solution  and  crystallization.  .      «  'xccu 

M.  Liebig  proposes  the  following  process  for  obtaining  chlorate  of  potash  :— 
Heat  chloride  of  lime  in  water  till  it  ceases  to  destroy  vegetable  colors.  In  this  case  a 
mixture  of  chloride  of  calcium  and  chlorate  of  potash  is  obtained.  This  is  to  be  (UsSlved 
K.  «H^rn;:'/.h  ^  ^^l"''^"  concentrated  by  evaporation,  chloride  of  potassium  is  to 
be  added,  and  then  suffered  to  cool.  After  cooling,  a  quantity  of  crj  stals  of  chlorate  of 
potash  IS  obtained  which  are  to  be  redissolved  and  crystallized  again  to  purify  them  M 
Liebig  considers  that  this  will  be  a  cheap  process  for  obtaining  chloral  of  poUh  Fr^ 
12  ounces  of  chloride  of  lime,  of  so  bad  a  quality  that  it  left  65  per  cent  of  Lolubte 
matter,  he  obtained  an  ounce  of  chlorate  of  potash  msoiuoie 

The  only  difficulty  to  overcome  in  this  process  is,  from  the  chloride  of  lime  not  beine 
80  easily  decomposed  by  heat  as  is  generally  supposed ;  a  solution  of  it  may  be  kept  bi^ 
ing  for  an  hour  withou  losing  its  bleaching  power.  The  best  method  Ts  to  fom  a  ihk 
paste  with  chloride  of  hme  and  water,  and  then  to  evaporate  it  to  difness  IfTbe  r" 
qujred  to  prepare  it  by  passing  chlorine  into  cream  of  hme,  it  is  advi;rg;ous  to  keeP  ^t 

The  chlorate  of  potash  which  separates  from  the  solution  by  cn'stallization  has  not 
the  form  of  scales  which  it  usually  possesses,  but  is  prismatic :  wheSer  S  occasTon^ 
SullTrm  '    ""  ""'  been  ascertained;  but  on  re-crystallizing,  it  is  oirainTin  tSi 

The  solution  ought  not  rnerely  to  be  left  to  cool,  in  order  to  procure  crystals  for  the 
iXT^Z^r^^Vr,  f:^l  ^^""^"^^^  ^^^'^  ^"-  --^'^^^  '^^'^^^^  cr7statco'nUnt 

The  following  modification  of  the  process  for  making  chlorate  of  potash  i«!  that  of  M 
Vee.  A  solution  of  chloride  of  lime,  marking  18°  or  20^  Baume,  is  o  be  set  u  Jon  the  fifi 
in  a  lead  or  cast  iron  pot,  and  when  it  begins  to  get  hot,  there  is  to  be  dissXd  in  it  a 
quantity  of  chloride  of  potassium  sufficient  to  raise  the  hydrometer  3  or  4  degrees  It 
must  be  then  concentrated  as  quickly  as  possible  till  it  marks  30°  or  31°,  takin?care'that 
It  does  not  boil  over  by  the  sudden  extrication  of  oxygen.     The  concent  atediquor  is  se 

^!i'i^uT^^^r  l""  ^-  '^^  *.'"  •  ^^"'•^  ^  ^^P°^'t«  «^  <=^^°r^te  of  potash  fojrmix^ 
with  chloride  of  potassmm.  The  mother  waters  being  evaporated  to  the  denshv  of  3^ 
afford  another  crop  of  crystals,  after  which  they  may  be  thfown  awav.  ^  ' 

The  salts  obtained  at  the  first  crystallization  are  to  be  re-dissolved,  and  the  solutioa 
^7of  S.''  ''   "  '"^  "  '"  '^  ^'''''''  "^^"  ''  ""^  ^-d  upon1oo?iJg  pTe  S 
Chlorate  or  oxymuriate  of  potash  has  a  cooling,  somewhat  unpleasant  and  nitrow 
taste.     It  does  not  bl^ch.     At  60°  F.  100  parts  of  water  dissolve  si  parts  of  it  and^ 
Its  boiling  point  or  220°,  sixty  parts.     When  heated  to  dull  ignition  in  a  iass  retort  h 
gives  put  39^5  per  cent,  of  its  weight  of  oxygen,  and  becomes  therebfchlord^^^ 
potassium.     When  strongly  triturated  in  a  mortar  it  crackles,  throws  out  sparks  and  ^- 
comes  luminous.  It  deflagrates  upon  red-hot  cinders  like  nitre :  when  trituraKCwirk 
^.Iphur,  or  phosphorus,  it  detonates  with  great  violence,  not  without  danger  to  the  hrnS 
of  the  operator.  If  they  be  not  protected  by  a  thick  glove.    Similar  detonat  on.  may  W 
produced  with  cinnibar  or  vermilion,  sulphurct  of  potassium,  su-ar   vX  ie  oik    ll 
but  they  can  be  effected  only  by  the  smart  blow  of  a  heated  Immer  and  anvb     A 
mixture  of  sugar  or  starch  with  chlorato  of  potash  is  readily  inflamS  by  a  drop  of  si 
phunc  acid,  and  this  experiment  is  the  basis  of  the  preparation  of  the  oxy-enated  m^tchS 
as  they  have  been  commonly  called.     The  folloirinrfonnula  fomfa  g^  p^ste  fo^ 
ippmg  the  said  matches,  made  of  narrow  slips  of  either  wood  or  card.    TMrty^parts  of 
the  chlorate  m  fine  powder  are  to  be  mixed  gentlv  with  a  .nntnio  «^^.«       ^  P.'Jv 
pans  of  flowers  of  sulphur  well  levigated,  e&'CNveTglV^^^^^^^ 
of  vermilion  to  give  the  whole  a  rose  tint.    We  begin  by  mhcing  tenderly  togethS 
Ihe  sugar,  the  gum,  and  the  salt  previously  pulverised ;  we  then  add  as  much  water 
as  shall  reduce  the  mixture  to  a  thin  paste,  and  lastly  introduce  the  sulphur;  after 
which  all  must  be  well  incorporated.     The  points  of  the  matches,  either  previously 
tipped  with  sulphur  or  not^  are  to  be  dipped  in  that  paste,  so  as  to  get  coated  with  a 
little  of  it,  and  are  lastly  laid  in  a  warm  place  till  they  become  thoroughly  dry.     To 
kindle  one  of.  them,  it  must  be  touched  with  strong  sulphuric  acid,  which,  for  this 
purpose,  is  usually  kept  in  a  small  well-stopped  vial,  and  thickened  with  amianthus. 
Aspen  is  reckoned  the  best  wood  for  matches. 

Of  late  years  a  detonating  priming  for  fire-arms  has  been  much  used  with  the  percus- 
sion locka  The  simplest  formula  for  making  it  is  to  take  ten  parts  of  gunpowder,  to 
lixiviate  it  with  water,  and  to  mix  the  residuum,  while  moist,  with  five  parts  and  a 
quarter  of  chlorate  of  potash,  reduced  to  an  extremely  fine  powder.  The  paste  may  be 
made  pretty  thin,  for  the  salt  is  sparingly  soluble  in  cold  water,  and  it  mixes  best 
when  tolerably  fluid.    This  powder  when  dry  is  dangerous  to  handle,  being  very  apt  to 


\^ 


406 


CHLORINE. 


explode.  But  this  danger  is  guarded  against  bv  letting  fall  a  drop  of  the  paste  into  each 
copper  percussion  cap,  and  leaving  it  to  dry  there.  In  the  detonation  of  this  powder, 
besides  muriate  of  potash,  there  are  generated  a  little  sulphate  of  potash  and  chlorine 
gas,  which  rust  the  metal  very  fast  For  which  reason  fulminate  of  mercury  is  now 
preferred  by  many  sportsmen  as  a  detonating  powder.    See  Fulminate. 

The  following  ingenious  and  easy  way  of  making  this  valuable  chlorate  has  been 
lately  suggested  by  Professor  Graham : — ^Mix  equal  atomic  weights  of  carbonate  of 
potash  and  hydrate  of  lime  (70  of  the  former,  if  pure,  and  37  of  slaked  lime  in  powder), 
diffuse  them  through  cold  water,  and  transmit  chlorine  gas  through  the  mixture.  The 
gas  is  absorbed  with  great  avidity,  and  the  production  of  a  boiling  heat  When  the 
^turation  is  complete,  carbonate  of  lime  remains,  and  a  mixture  of  muriate  and  chlorate 
of  potash,  which  latter  salts  are  to  be  separated,  as  usual,  by  the  difference  of  their 

solubility  in  water.  ^  •        /-      ^  a 

It  has  been  remarked  on  the  above  process,  that  it  effects  no  saving  of  potassa,  and 
therefore  is  far  inferior  to  the  one  long  practised  in  several  parts  of  Germany,  especially 
at  Giessen,  and  introduced  into  this  country  a  good  many  years  ago  by  Dr.  Wagen- 
mann,  from  Berlin.  The  chlorine  is  passed  into  a  mixture  of  one  equivalent  of  chlo- 
ride of  potassium  (76),  and  6  equivalents  of  hydrate  of  lime  (222),  previously  stirred  with 
water  to  the  consistence  of  a  thin  paste.  Thus  the  calcium  of  the  lime  unites  with  the 
chlorine  to  form  chloride  of  calcium,  while  the  chloride  of  potassium  is  converted  into 
chlorate  of  potassa,  which  salt  is  easily  separated  in  crystals  by  its  sparing  solubility. 

Chlorate  of  potash  may  also  be  made  by  saturating  with  chlorine  a  mixture  of  74 
parts  of  chloride  of  potassium  (muriate  of  potash)  and  168  parts  of  quicklime,  brought 
to  the  consistence  of  a  thin  pap  by  the  cautious  addition  of  water.  The  mass  being 
dissolved  in  warm  water,  and  evaporated  and  cooled,  yields  crystals  of  chlorate  of 
potash,  while  a  mother  water  of  chloride  of  calcium  (muriate  of  lime)  remains.  The 
following  process  has  likewise  been  prescribed :— Mix  10  parts  of  good  chloride  of 
lime  with  water  into  a  pap,  and  evaporate  to  dryness*  whereby  it  is  converted  into 
a  mixture  of  chloride  of  calcium  and  chloride  of  lime  devoid  of  bleaching  power ; 
dissolve  it  in  water,  filter,  concentrate  the  solution  by  evaporation,  then  add  to  it  1 
part  of  chloride  of  potassium,  and  cool  for  crystallization.  Tlie  salt  which  may  thereby 
be  separated  from  the  chloride  of  calcium  will  afford  0-83  of  pure  chlorate  of  potash.  B^ 
this  process  of  Professor  Liebig  five  sixths  of  the  potash  are  saved,  but  much  oxygen  is 
wasted  in  the  evaporation  to  dryness  of  the  chloride  of  lime,  and  consequently  much 
chloric  acid  is  lost  towards  the  production  of  the  salt.  V6e  mixes  the  chloride  of  lime 
pap  before  heating  it,  with  the  chloride  of  potassium,  boils  the  mixture  smartly,  whereby 
much  oxygen  is  undoubtedly  thrown  off,  and  then  sets  the  liquor  aside  to  crystallize. 
I,.  Gmelin  suggests  that  saturation  of  the  liquor  with  chlorine  before  boiling  might 
be  advantageous.  Gay  Lussac  has  suggested  to  make  this  valuable  salt  by  pre- 
cipitating a  solution  of  chloride  of  lime  with  carbonate  (or  sulphate)  of  potash,  satu- 
rating the  liquor  after  filtration  with  chlorine  gas,  evaporating,  and  crystallizing.      ^ 

Profossor  Juch's  process  is  to  pass  chlorine  gas  into  a  mixture  of  1  pound  caustic 
lime  and  1  pound  carbonate  of  potash,  with  8  pounds  of  water.  The  resulting  chloride 
of  potash  readily  separates  in  the  filtered  liquid  by  crystallization  from  the  very  soluble 
chloride  of  calcium.  By  this  method  potash  is  not  wasted  m  the  useless  production 
of  chloride  of  potassium. 

CHLORATES,  compounds  of  chloric  acid  with  the  salifiable  bases.  The  only  acid  be- 
longing to  this  class  of  any  manufacturing  importance  is  the  following : 

CHLORIC  ACID;  the  acid  constituent  of  the  preceding  salt;  it  consists  of  one 
equivalent  prime  of  chlorine  =  35-476,  -|-  5  of  oxygen,  =  40-065 ;  of  which  the  sum  75-535 
is  the  prime  equivalent  of  the  acid.  .  v      •    i    t 

CHLORINE ;  the  most  energetic  of  the  undecompounded  bodies,  or  chemical  ele- 
ments as  they  are  usually  called,  exists,  under  ordinary  circumstances,  as  a  greenish  yel- 
low gas,  but,  when  exposed  to  a  pressure  of  4  atmospheres,  it  becomes  a  yellow  transpa- 
rent liquid.  In  the  first  state,  its  density  compared  to  air,  reckoned  1-000,  is  2-47; 
in  the  second,  its  density  compared  to  water,  1-000,  is  1-33.  No  degree  of  cold  hitherto 
tried,  has  liquefied  the  gas  when  dry.  It  is  obtained  by  putting  into  a  glass  re- 
tort a  mixture  of  3  parts  of  common  salt,  with  2  parts  of  peroxyde  of  manganese,  and 
pouring  upon  it  2  parts  of  sulphuric  acid  diluted  with  its  own  weight  of  water ;  or,  more 
conveniently,  by  pouring  moderately  strong  muriatic  acid  upon  peroxyde  of  manganese  in 
a  retort ;  and  in  either  case  applying  the  gentle  heat  of  a  spirit  lamp  or  a  water  bath, 
while  the  beak  of  the  retort  is  plunged  under  brine  upon  the  shelf  of  the  pneumatic  trough. 
The  gas  issues,  and  may  be  received  in  the  usual  way  into  inverted  glass  jars,  or  vials  j 
but  the  first  which  comes  over,  being  mixed  with  the  air  of  the  retort,  must  be  rejected. 
It  has  a  peculiar  smell,  and  irritates  the  nostrils  most  violently  when  inhaled,  as  also  the 
windpipe  and  lungs.  It  is  eminently  noxious  to  animal  life,  and,  if  breathed  in  its  un- 
diluted state,  would  prove  instantly  fatal.    It  supports  the  combustion  of  many  bodies. 


1 


CHLORIDE  OF  LIME. 


407 


and  indeed  spontaneously  bums  several  without  their  being  previously  kindled.  The 
resulting  combinations  are  called  chlorides,  and  act  most  important  parts  in  many 
manufacturing  processes. 

Water  absorbs,  at  the  ordinary  temperature  of  the  atmosphere,  about  double  its  vo- 
lume of  chlorine,  and  acquires  the  colour,  smeU,  and  taste  of  the  gas,  as  well  as  its  power 
of  destroying  or  bleaching  vegetable  colours.  When  this  aqueous  chlorine  is  cooled  to 
36  Pahr.  dark  yeUow  crystalline  plates  appear  in  it  of  the  hydrate  of  chlorine,  which 
are  composed  in  100  parts  of  27-7  chlorine,  and  72-3  water,  ff  these  crystals  be  heated 
to  about  46°  they  hquefjr,  and  the  gas  flies  off. 

Chlorine  has  a  powerful  affinity  for  hydrogen,  not  only  combining  with  it  rapidly  in 
the  gaseous,  but  seizing  it  in  many  of  its  liquid  and  solid  combinations,  as  in  volatile 
oils,  which  it  inflames,  and  m  yellow  wax,  cotton  and  flax,  which  it  whitens.  The  com 
^^^u^^  ^^.;**^^"?«  *°<1  hydrogen  gases  is  muriatic  acid  gas.  Manganese,  when  mixed 
with  liquid  muriatic  acid,  as  m  the  above  process,  abstracts  the  hydrogen,  and  lets  the 
chlorine  gas  go  free.  When  chlorine  is  passed  into  water,  it  decomposes  some  of  it,  seizes 
Its  hydrogen  to  form  a  little  muriatic  acid,  and  enables  its  oxygen  to  unite  either  with 
the  chlorine,  into  chlorous  acid,  or  with  the  remaining  water,  and  to  constitute  oxygen- 
ated water.  Hence,  aqueous  chlorine,  exposed  to  the  sunbeam,  continually  evolves 
oxygen,  and,  ere  long,  becomes  muriatic  acid. 

This  watery  compound  acts  in  a  powerful  way  upon  coloured  vegetable  fibres,  ex- 
tracting their  hydrogen  or  colouring  element  by  the  twofold  affinities  of  the  chlorine 
«nd  oxygen  for  it 

Hence  chlorine  as  a  bleaching  a^ent,  requires  to  be  tempered  by  the  quiescent  affinity 
of  some  alkaline  base,  potash  or  lime.  Malaria,  or  morbific  and  putrescent  miasmata^ 
consists  chiefly  of  hydrogenous  matter  as  their  basis,  and  are  best  counteracted  by 
chlorine,  where  it  can  be  conveniently  applied. 

Chlorides  of  Potmk,  Soda,  and  Lime.— These  are  the  most  important  preparations 
through  which  chlorine  exercises  its  peculiar  powers  upon  the  objects  of  manufactures. 
When  a  weak  solution  of  caustic  potash  or  soda  is  saturated  with  chlorine,  it  affords  a 
bleaching  liquor  which  is  still  used  by  some  bleachers  and  calico-printers  for  their  most 
delicate  processes ;  but  the  price  of  the  alkalis  has  led  to  the  disuse  of  these  chlorides  as 
a  general  means,  and  has  occasioned  an  extensive  employment  of  chloride  of  lime.  Upon 
the  manufacture  of  this  interesting  compound  I  made  an  elaborate  series  of  experiments, 
^^VVolT  ft'  Publishea  the  results  in  the  13th  volume  of  Brande's  Journal  for 

April,  182i.  1  have  no  reason  to  suppose,  from  any  thing  that  has  been  published  since, 
that  the  processes  there  described  have  been  essentially  improved,  or  that  any  errors, 
either  theoretical  or  practical,  of  any  moment,  exist  in  that  memoir.  I  shall  therefore 
first  present  my  readers  with  a  brief  abstract  of  it,  and  then  make  such  observations  as 
subsequent  inquiries  suggest. 

In  the  researches  which  I  made,  at  many  different  limes,  upon  the  nature  of  the  chlo- 
nde  of  lime,  I  generally  sought  to  combine  the  information  flowing  from  both  synthesis 
and  analysis;  that  is,  I  first  converted  a  known  portion  of  hydrate  of  lime  into  bleach- 
mg-powder,  and  then  subjected  this  chloride  to  analysis. 

Two  hundred  grains  of  the  atomic  proto-hydrate  of  pure  lime  were  put  into  a  glass 
globe,  which  was  kept  coJd  by  immersion  in  a  body  of  water  at  50°.  A  stream  of 
chlorine,  after  being  washed  in  water  of  the  same  temperature  in  another  glass  globe. 

hydrate.  The  globe  with  the  lime  was  detached  from  the  rest  of  the  apparatus  from 
time  to  time,  that  the  process  might  be  suspended  as  soon  as  the  augmentation  of  weight 
!^'t*^  T.n'  *»^PP^"^^^^^"  the  200  grains  of  hydrate,  containing  15 19  of  lime,  had 
absorbed  130  grams  of  chlorine.  By  one  analytical  experiment,  it  was  found  that  dilute 
muriatic  acid  expelled  from  50  grains  of  the  chloride,  20  grains  of  chlorine,  or  40  per 
cent  ;  and  by  another  from  40  grains,  16-25  of  gas,  which  is  40-6  per  cent.  From  the 
res^uum  of  the  first  39-7  gramt  of  carbonate  of  lime  were  obtained  by  carbonate  of 
ammonia ;  from  that  of  the  second,  36-6  of  ignited  muriate  of  lime.  ITie  whole  resulU 
are  therefore  as  follows : — 


Chlorine  -  - 
Lime-  -  -  - 
Water 

Synthesis. 

1st  Analysis. 

Sd  Analysis. 

Mean 

39-39 
4600 
14-60 

40-00 
44-74 
15-26 

40-62 
46-07 
13-31 

40-31 
45-40 
14-28 

10000 

100-00 

100-00 

100-00 

tr 


408 


CHLORIDE  OF  LIME. 


Though  the  heat  generated  by  the  action  of  the  dilute  acid  had  earned  off  m  the 
analytical  experiments  a  small  portion  of  moisture  with  the  chlorine,  yet  their  accordance 
with  the  synthetic  experiment  is  sufficiently  good  to  confirm  the  general  results.  The 
above  powder  appears  to  have  been  a  pure  chloride,  without  any  mixture  of  munate. 
But  it  exhibits  no  atomic  constitution  in  its  proportions.  ,,   ,    ^,  j 

To  200  grains  of  that  hydrate  of  lime  30  grams  of  water  being  added,  the  powder 
was  subjected  to  a  stream  of  chlorine  in  the  above  way,  till  saturation  took  place.  Its 
increase  of  weight  was  150  grains.  .  .       ^  ^x. 

It  ought  to  be  remarked,  that  in  this  and  the  preceding  experiment,  there  was  no 
appreciable  pneumatic  pressure  employed  to  aid  the  condensation  of  chlorine.  In  the 
last  case,  we  see  that  the  addition  of  30  grains  of  water  has  enabled  the  lime  to  absorb 
20  grains  more  of  chlorine,  being  altogether  a  quantity  of  gas  nearly  equal  to  that  of 
the  dry  lime.  Thus,  an  atom  of  lime  seems  associated  with  seven  ninths  of  an  atom  of 
chlorine.     Analysis  by  muriatic  acid  confirmed  this  composition.    It  gave 

Chlorine        •        89-5  — 51 '8  cubic  inches. 

Lime  -        39-9 

Water  -        20*6 


100-0 


A  great  variety  of  apparatus  has  been  at  different  times  contrived  for  favouring  the 
combination  of  chlorine  with  the  slaked  lime  for  the  purposes  of  commerce.     One  of 
the  most  ingenious  forms  is  that  of  a  cylinder,  or  barrel,  furnished  with  narrow  wooden 
shelves  within,  and  suspended  on  a  hollow  axis,  by  which  the  chlorine  was  admitted,  and 
round  which  the  barrel  was  made  to  revolve.     By  this  mode  of  agitation,  the  lime-dust, 
being  exposed  on  the  most  extensive  surface,  was  speedily  impregnated  with  the  gas,  to 
the  requisite  degree.     Such  a  mechanism  I  saw  at  MM.  Oberkampf  and  Widmer's  cele- 
brated/aftnaw  de  toilcs  peintes,  at  Jouy,  in  1816.     But  this  is  a  costlv  refinement,  in- 
admissible on  the  Urgest  scale  of  British  manufacture.      The  simplest,  and,  in  my 
opinion,  the  best  construction  for  subjecting  lime-powder  to  chlorine,  is  a  large  chamber 
8  or  9  feet  hi-'h,  built  of  silicious  sandstone,  having  the  joints  of  the  masonry  secured 
with   a  cement  composed  of  pitch,  resin,  and  dry  gypsum  in  equal  parts.     A  door  it 
fitted  into  it  at  one  end,  which  can  be  made  air-tight  by  strips  of  cloth  and  clay-lute. 
A  window  on  each  side  enables  the  operator  to  judge  how  the  impregnation  goes  on  by 
the  color  of  the  air,  and  also  gives  light  for  making  the  arrangements  within  at  the 
commencement  of  the  process.     As  water  lutes  are  incomparably  superior  to  all  others, 
where  the  pneumatic  pressure  is  small,  I  would  recommend  a  large  valve  or  door  on  thij 
principle  to  be  made  in  the  roof,  and  two  tunnels  of  considerable  width  at  the  bottom  of 
each  side  wall.     The  three  covers  could  be  simultaneously  lifted  off  by  cords  passing 
over  a  pulley,  without  the  necessity  of  the  workman  approaching  the  deleterious  gas, 
when  the  apartment  is  to  be  opened.     A  great  number  of  wo<Klen  shelves,  or  ratjer 
trays  8  or  10  feet  long,  2  feet  broad,  and  1  inch  deep,  are  provided  to  receive  the  riddled 
slaked  lime,  containing  generally  about  2  atoms  of  lime  to  3  of  water.     These  shelves 
are  piled  one  over  another  in  the  chamber,  to  the  height  of  5  or  6  feet,  cross  bars  below 
each  keeping  them  about  an  inch  asunder,  that  the  gas  may  have  free  room  to  circulate 
over  the  surface  of  the  calcareous  hydrate.  ,        .     •    i 

The  alembics  for  generating  the  chlorine,  which  are  usually  nearly  spherical,  are  la 
some  cases  made  entirely  of  lead,  in  others  of  two  hemispheres,  joined  together  in  the 
middle,  the  upper  hemisphere  being  lead,  the  under  one  cast-iron.  The  first  kind  of 
alembic  is  enclosed,  for  two  thirds  from  its  bottom,  in  a  leaden  or  iron  case,  the  interval 
of  two  inches  between  the  two  being  destined  to  receive  steam  from  an  adjoining  boiler. 
Those  which  consist  below  of  cast-iron  have  their  bottom  directly  exposed  to  a  very 
gentle  fire;  round  the  outer  edge  of  the  iron  hemisphere  a  groove  is  cast,  into  which  the 
under  edge  of  the  leaden  hemisphere  fits,  the  joint  being  rendered  air-tight  by  Roman 
or  patent  cement.  In  this  leaden  dome  there  are  four  apertures,  each  secured  by  a  water- 
lute  The  first  opening  is  about  10  or  12  inches  square,  and  is  shut  with  a  leaden  valve, 
with  incurvated  edges,  that  fit  into  the  water  channel  at  the  margin  of  the  hole.  It  is 
destined  for  the  admission  of  a  workman  to  rectify  any  derangement  in  the  apparatus  of 
rotation,  or  to  detach  hard  concretions  of  salt  from  the  bottom.  ,  .   ^     ■,     ... 

The  second  aperture  is  in  the  centre  of  the  top.  Here  a  lube  of  lead  is  fixed,  which 
descends  nearly  to  the  bottom,  and  down  through  which  the  vertical  axis  passes.  To 
its  lower  end  the  cross  bars  of  iron,  or  of  wood,  sheathed  with  lead,  are  attached,  by 
whose  revolution  the  materials  receive  the  proper  agitation  for  mixing  the  dense  manga- 
nese with  the  sulphuric  acid  and  salt.  The  motion  is  communicated  either  by  the  hand 
of  a  workman  applied  from  time  to  time  to  a  winch  at  top,  or  it  is  given  by  connecting 
the  axis  with  wheel  work,  impelled  by  a  stream  of  water  or  a  steam-engine.    The  third 


CHLORIDE  OF  LIME. 


409 


opening  admits  the  syphon- formed  funnel,  through  which  the  sulphuric  acid  is  introduced; 
and  the  fourth  is  the  orifice  of  the  eduction-pipe. 

Manufacturers  differ  much  from  each  other  in  the  proportion  of  their  materials  for 
generating  chlorine.  In  general,  10  cwt.  of  salt  are  mixed  with  from  10  to  14  cwt.  of 
manganese,  to  which  mixture,  after  its  introduction  into  the  alembic,  from  12  to  14  cwt. 
of  sulphuric  acid  are  added  in  successive  portions.  That  quantity  of  oil  of  vitriol  must, 
however,  be  previously  diluted  with  water,  till  its  specific  gravity  becomes  about  1*6. 
But,  indeed,  tliis  dilution  is  seldom  actually  made,  for  the  manufacturer  of  bleaching- 
powder  almost  always  prepares  his  own  sulphuric  acid  for  the  purpose,  and  therefore 
carries  its  concentration  no  higher  in  the  leaden  boilers  than  the  density  of  1*65,  which 
from  my  table  of  sulphuric  acid,  indicates  \  of  its  weight  of  water,  and  therefore  § 
more  of  such  acid  must  be  used. 

The  fourth  aperture,  I  have  said,  admits  the  eduction  pipe.  This  pipe  is  afterwards 
conveyed  into  a  leaden  chest  or  cylinder,  in  which  all  the  other  eduction  pipes  also 
terminate.  They  are  connected  with  it  simply  by  water-lutes,  having  a  hydrostatic 
pressure  of  2  or  3  inches.  In  this  general  diversorium  the  chlorine  is  washed  from 
adhering  muriatic  acid,  by  passing  through  a  little  water,  in  which  each  tube  is  im- 
mersed, and  from  this  the  gas  is  let  off  by  a  pretty  large  leaden  tube,  into  the  combina- 
tion room.  It  usually  enters  in  the  top  of  the  ceiling,  whence  it  diffuses  its  heavy  gas 
equally  round. 

Four  days  are  required,  at  the  ordinary  rate  of  working,  for  making  good  marketable 
bleach  ing-powder.  A  more  rapid  formation  would  merely  endanger  an  elevation  of 
temperature,  productive  of  muriate  of  lime,  at  the  expense  of  the  bleaching  quality.  Bui 
skilful  manufacturers  use  here  an  alternating  process.  They  pile  up,  first  of  all,  the 
wooden  trays  only  in  alternate  shelves  in  each  column.  At  the  end  of  two  days  the 
distillation  is  intermitted,  and  the  chamber  is  laid  open.  After  two  hours  the  workman 
enters,  to  introduce  the  alternate  trays  covered  with  fresh  hydrate  of  lime,  and  at  the 
same  time  rakes  up  thoroughly  the  half-formed  chloride  in  the  others.  The  door  is  then 
secured,  and  the  chamber,  after  being  filled  for  two  days  more  with  chlorine,  is  again 
opened,  to  allow  the  first  set  of  trays  to  be  removed,  and  to  be  replaced  by  others,  con 
tajaing  fresh  hydrate,  as  before.  Thus  the  process  is  conducted  in  regular  alternation  : 
thus,  to  my  knowledge,  very  superior  bleaching-powder  is  manufactured,  and  thus  the 
chlorine  may  be  suffered  to  enter  in  a  pretty  uniform  stream.  But  for  this  judicious 
plan,  as  the  hydrate  advances  in  impregnation,  its  faculty  of  absorption  becoming 
diminished,  it  would  be  requisite  to  diminish  proportionately  the  evolution  of  chlorine, 
or  to  allow  the  excess  to  escape,  to  the  great  loss  of  the  proprietor,  and,  what  is  of  more 
consequence,  to  the  great  detriment  of  the  health  of  the  workmen. 

The  manufacturer  generally  reckons  on  obtaining  from  one  ton  of  rock-salt,  employed 
as  above,  a  ton  and  a  half  of  good  bleaching-powder.  But  the  following  analysis  of  the 
operation  will  show  that  he  ought  to  obtain  two  tons. 

When  a  mixture  of  sulphuric  acid,  common  salt,  and  black  oxyde  of  manganese  are 
the  ingredients  used,  as  by  the  manufacturer  of  bleaching-powder,  the  absolute  pro- 
portions are,  upon  the  oxygen  scale  of  equivalents :  — 

1  atom  muriate  of  soda         -         -        7*5  29*70  100-0 

1  atom  peroxyde  of  manganese  -        5-5  21*78  73*3 

2  atoms  oil  of  vitriol  1-846       -         -      12*25  4S*52  163-3 


25.25 

100.00 

And  the  products  ought  tobe ;  • 

— 

Chlorine  disengaged      - 

•  1  atom. 

4-5 

1782 

Sulphate  of  soda 

-  1    — 

9-0 

35*64 

Proto- sulphate  of  manganese 

-  1    — 

9*5 

37*62 

Water 

-  2    — 

2*25 

8-92 

25*25  100*00 

These  proportions  are,  however,  very  different  from  those  employed  by  many,  nay, 
I  believe  by  all  manufacturers ;  and  they  ought  tc  be  so,  on  account  of  the  impurity 
of  their  oxyde  of  manganese.  Yet  making  allowance  for  this,  I  am  afraid  that  many  of  them 
commit  great  errors  in  the  relative  quantities  of  their  materials. 

From  the  preceding  computation,  it  is  evident  that  1  ton  of  salt  wilh  1  ton  of  the 
above  native  oxyde  of  manganese  properly  treated,  would  yield  0*59  of  a  ton  of  chlorine, 
which  would  impregnate  1*41  tons  of  slaked  lime,  producing  2  tons  of  bleaching-powder, 
stronger  than  the  average  of  ihe  commercial  specimens ;  or  allowing  for  a  little  Joss, 
which  is  unavoidable,  would  afford  2  tons  of  ordinary  powder,  wilh  a  little  more  slaked 

lime. 

Fig.  354  represents  a  retort  of  lead,  well  adapted  to  the  evolution  of  chlorine  from  the 
mixture  of  salt,  manganese,  and  sulphuric  acid,  or  from  manganese  and  muriatic  acid. 
Vol.  L  3G 


II 


(I 


'i 


J 

i 


410 


CHLORIDE  OF  LIME. 


The  interior  vessel  is  cast  in  lead,  and  it  has  round  its  bottom  part  a  cast-iron  steam 
case.     The  salt  and  manganese  are  introduced  by  the  aperture  c,  and  the  sulphorio 


acid  by  the  syphon  funnel  f.  The  contact  of  these  three  substances  is  continually 
renewed  by  the  agitator  or  stirrer  b,  which  consists  of  wrought  or  cast  iron  sheathed 
with  lead-  e  is  the  gas  discharge  pipe.  The  residuums  are  drawn  oflP  by  the  bottom 
discharge  pipe  g.     The  heating  case  receives  its  steam  bj  the  pipe  A. 

The  chlorine  gas,/^.  355.  is  conveyed  from  the  retort  b,  mto  the  chamber  i,  by  the  tube 
SEE.  This  chamber  is  divided  into  four  compartments,  to  receive  the  gas  disengaged 
from  four  retorts,  like  the  above.  The  bottom  of  it  is  covered  with  a  stratum  three 
or  four  inches  thick  of  quicklime,  newly  slaked  and  sifted,  which  is  stirred  about  from 
time  to  time,  by  the  rakes  l  l  l  l.  When  the  saturation  is  suflScient,  the  chloride  of 
lime  is  taken  out  by  the  doors  k  k  k  k.  The  size  of  this  apparatus  allows  2  cwt.  of 
manganese,  and  its  equivalent  quantity  of  salt  and  sulphuric  acid,  or  of  muriatic  acid, 
to  be  introduced  at  once  into  the  retort     d  is  the  handle  of  the  agitator. 

The  same  form  of  retort  will  suit  perfectly  well  to  prepare  chlorine  for  making 
liquid  chloride  of  lime,  which  is  preferred  by  many  bleachers  and  calico-printers  who 
have  conveniences  for  preparing  it  themselves.  The  most  concentrated  solutions  of  the 
dry  chloride  of  lime  do  not  mark  more  than  6°  B.  (sp.  grav.  1-04),  and  discolour  only 
60  volumes  of  Gay  Lussac's  solution  of  indigo,  whilst  the  chloride  made  in  the  humid 
way  marks  from  8°  to  9°  B.  (about  1-060),  and  discolours  80  volumes  of  the  same 

In  the  chloride  of  lime  apparatus,  most  generally  used  by  the  skilful  calico-printers 
of  Miilhausen,  the  mixture  of  muriatic  acid  and  manganese  is  put  into  glass  globes, 
with  long  necks,  heated  upon  a  sand-bath.  The  chlorine  is  conveyed  by  glass  tubes 
into  a  cylindrical  stone  cistern,  containing  milk  of  lime.  Tlie  furnace  of  the  sand- 
baths  is  made  of  cast  iron,  and  has  brick  partitions,  to  give  each  retort  its  own  fire. 
The  smoke  of  all  these  fires  goes  off  by  a  flue  into  sheet  iron  pipes.  The  cistern  is 
made  of  siliceous  sandstone.  Its  cover  is  of  wood,  coated  with  a  resinous  cement ;  and 
it  fits  at  its  edges  into  grooves  cut  in  the  stone.  A  wheel  serves  to  agitate  the  liquid 
continually;  its  paddles  being  kept  at  two  inches  distance  from  the  sides  of  the  cistern. 
The  milk  of  lime  is  introduced  by  a  funnel,  and  the  chloride  is  drawn  oflF  by  a 
discharge  pipe.  I  think  the  lead  retort  and  agitator  used  in  this  country  greatly 
preferable  to  the  experimental  laboratory  plan  described  above.  In  all  such  appa- 
ratus we  should  avoid  giving  any  pressure  to  the  tubes  or  vessels,  and  should  not 
therefore  dip  the  extremities  of  the  gas  pipes  beneath  the  surface  of  the  liquid,  but 
rather  facilitate  the  combination  of  the  cWorine  and  the  lime,  by  enlarging  the  surfaces 
of  contact  and  by  agitating.  Intermediate  vessels  containing  water,  or  the  chemical 
cascade  of  M.  Clement,  are  very  useful  for  absorbing  any  muriatic  acid  which  may 
be  disengaged  along  with  the  chlorine,  and  thereby  preventing  the  needless  formation  of 
muriate  of  lime  in  the  chambers  or  cisterns  of  impregnation. 

When  the  solution  of  the  chlorine  of  lime  is  mixed  with  hydrate  of  lime,  it  bears, 
without  decomposing,  a  pretty  high  temperature,  provided  it  be  not  too  long  continued ; 
it  may  even,  in  certain  cases,  be  raised  too  near  the  boiling  point  without  suffering  a 
marked  loss'  of  its  discolouring  power ;  but  when  the  chloride  is  deprived  of  that 
excess  of  lime,  it  is  decomposed  in  a  short  time,  even  at  a  heat  t)f  110°  F. 

When  chlorine  is  admitted  to  milk  of  lime,  it  infallibly  produces  some  muriate  of 
lime  •  but  the  quantity  is  kept  at  a  minimum  by  constantly  prescribing  an  excess  of 


CHLORIDE  OF  LIME. 


411 


lime  to  the  gas  with  the  agitator,  and  by  keeping  the  temperature  as  low  as  possible. 
Hence  the  influx  of  gas  should  not  be  so  rapid  as  to  generate  much  heat.  An  automatic 
agitator,  moved  by  steam  or  water  power,  is  therefore  much  better  than  one  driven  by 
the  hand  of  the  operator,  who  is  apt  to  intermit  his  labours.  If  the  liquor  becomes  hot 
at  the  end  of  the  process,  it  should  be  immediately  drawn  off  into  large  stone  bottles, 
and  cooled.  The  rose-colour  which  sometimes  supervenes  is  due  to  a  minute  quantity 
of  manganese.  The  strongest  liquid  chloride  of  lime  that  can  be  prepared  will  not  dis- 
colour more  than  80  times  its  volume  of  Gay  Lussac's  indigo  test. 

On  acting  upon  cotton  cloth  with  a  concentrated  solution  of  chloride  of  lime,  at  from 
110°  to  120°  R,  pure  carbonic  acid  gas  is  disengaged,  and  the  texture  of  the  cloth  is 
injured.  Here  the  hydrogen  of  the  water  and  the  cotton  being  seized  by  the  chlorine 
the  liberated  oxygen  combines  with  the  carbon  to  form  carbonic  acid.  In  the  discharge 
troughs,  where  printed  calicoes  are  passed  through  strong  solutions  of  chloride  of  lime, 
stalactitic  crusts  of  carbonate  of  lime  come  to  be  formed  in  this  way. 

The  chlorometre  of  Gay  Lussac  consists  of  a  test  solution  of  indigo  and  a  graduated 
tube.  One  part  of  the  best  indigo,  passed  through  a  silk  sieve,  is  to  be  dissolved  in 
nine  parts  of  concentrated  sulphuric  acid,  by  the  aid  of  a  water-bath  heat  applied  for 
six  hours.  The  sulphate  of  indigo  is  now  to  be  diffused  through  such  a  body  of  water 
that  one  volume  of  chlorine  gas  shall  discolour  exactly  ten  times  its  volume  of  this  dilute 
solution.     The  test  liquor  should  be  protected  from  the  agency  of  light. 

Mr.  Crura,  of  Thorniebank,  near  Glasgow,  has  lately  modified  Dr.  Dalton's  copperas 
test  for  chloride  of  lime,  and  made  it  convenient  to  a  practical  man.  The  doctor  justly 
considered  that  the  more  chlorine  any  bleaching  powder  contains,  the  more  of  the  green 
sulphate  of  iron  will  it  convert  into  the  red  sulphate,  so  that  we  have  only  to  add  suc- 
cessive portions  of  the  chloride  to  a  given  weight  of  the  dissolved  copperas,  and  note 
the  point  at  which  all  the  iron  gets  peroxidized.     See  Bleaching. 

Besides  the  method  of  analysis  already  quoted  from  my  memoir  on  the  manufacture 
of  the  chloride  of  lime,  another  occurred  to  me  long  ago,  which  I  often  practised  as  an 
easy  and  expeditious  test.  Chlorine  decomposes  ammonia.  If  therefore  water  of  am- 
monia, faintly  tinged  with  litmus,  be  added  slowly  to  a  solution  of  a  given  weight  of 
chloride  of  lime,  the  colour  will  continue  to  disappear  till  the  chlorine  be  all  neutralized 
by  the  reaction  of  the  h3drogen  of  the  ammonia.  The  quantity  of  liquid  ammonia 
of  a  certain  strength  requisite  to  neutralize,  in  this  way,  a  certain  volume,  say,  one 
cubic  inch,  or  a  thousand  grain  measures,  of  chlorine  gas,  may  be  assumed  as  the  stand- 
ard of  such  a  chlorometer.  As  chlorine  or  chloride  of  lime,  when  mixed  with  water  of 
ammonia,  causes  the  disengagement  of  azote,  the  quantity  of  this  gas  evolved  may 
also  be  made  the  foundation  of  an  accurate  and  convenient  chlorometer.  The  two  sub- 
stances should  be  mixed  over  mercury,  in  a  graduated  syphon  tube.  The  shut  end  a 
and  the  open  end  b  are  both  graduated  to  one  scale ;  for  example,  to  hundredths  of  a 
cubic  inch,  or  to  grain  or  10  grain  measures.  The  tube  is  to  be  filled  with 
mercury,  and  then  10  measures  of  it  are  to  be  displaced  at  the  open  end  by 
inserting  a  wooden  plug.  This  space  being  filled  with  the  solution  of  chlo- 
ride of  lime,  is  to  be  turned  up  into  the  shut  end  by  covering  the  open  end 
with  the  finger,  and  inverting  the  tube ;  a  few  drops  of  water  may  be  sent 
through  to  wash  the  mercury.  The  ammonia  being  now  let  up  wiU  cause  a 
reaction,  and  evolve  a  quantity  of  azote,  equivalent  to  the  chlorine  present. 
Tlie  action  may  be  quickened  by  holding  the  sealed  end  of  the  tube  obliquely 
over  a  lamp  heat.  Tlie  mercury  is  protected  from  the  chlorine  by  the  am- 
monia ;  and  should  any  notion  be  entertained  of  such  an  action,  the  ammonia 
L  \J  I  may  be  let  up  first  1  have  made  innumerable  researches  over  mercury  with 
^^-.''^  a  detached  apparatus  of  that  kind,  which  combines  precision  with  rapidity 
of  result  It  was  by  a  similar  mercurial  syphon  that  I  analysed  the  carbonates,  as  de- 
scribed in  the  first  edition  of  my  Dictionary  of  Chemistry,  82  years  ago. 

M.  Gay  Lussac  takes,  as  the  basis  of  his  indigo  chlorometer,  the  fact,  that  one  pound 
of  pure  crystallized  peroxide  of  manganese  is  capable  of  affording,  with  muriatic  acid, 
0*7964  parts  of  a  pound  of  chlorine;  or  one  kilogramme  yields  251^  litres;  that  is, 
one  pound  yields  251|  pound  measures.  Hence  3*98  grammes  of  that  manganese  are 
capable  of  affording  1000  gramme  measures,  or  1  litre  of  chlorine;  or,  in  round  num- 
bers, 4  grains  will  yield  1000  grain  measures.  This  quantity  of  gas  being  received 
into  that  volume  of'^  milk  of  lime,  constitutes  therefore  Gay  Lussac's  primary  standard. 
The  small  retort  in  which  the  manganese  and  muriatic  acid  are  put  ought  to  be  heated 
to  ebullition,  to  discharge  every  particle  of  chlorine.  To  prevent  the  manganese,  in 
this  experiment,  from  sticking  to  the  bottom  in  a  cake,  it  has  been  proposed  to  mix  it 
previously  with  a  little  plumbago.     See  Chlorometry. 

For  preparing  the  chlorides  of  potash  and  soda,  the  same  apparatus  may  be 
employed  as  for  the  liquid  chloride  of  lime.  The  alkaline  solutions  should  be  weak, 
containing  not  more  than  a  pound  to  the  gallon  of  water.    Potash  liquor,  saturated 

3G2 


Z 


412 


CHLORIDE  OF  UME. 


with  chlorine,  is  much  employed  at  Paris  for  whitening  linen,  under  the  name  of  the 
water  of  Javelle,  the  place  where  it  was  first  made  as  a  manufacture.  One  hundred 
parts  of  chloiine  are  said  to  saturate  133  parts  of  pure  potash,  and  195  of  the  carbonate : 
but  the  latter  should  not  be  used  for  preparing  the  bleaching  fluid,  as  the  carbonic 
acid  resists  the  combination  of  the  chlorme.  A  chloride  of  carbonate  of  soda  has 
been  lately  recommended  as  a  disinfecting  substance  against  contagious  miasmata  or 
fomites.  One  hundred  parts  of  chlorine  will  saturate  150  of  the  dry  carbonate,  and 
405  of  the  crystallized.  M.  Payen  prepares  this  medicinal  chloride,  by  adding  138 
parts  of  carbonate  of  soda  to  a  liquid,  consisting  of  water  1800,  chloride  of  lime  100, 
at  98°  of  strength,  by  Gay  Lussac^s  standard.  The  chloride  of  lime  is  to  be  dissolved, 
and  the  sediment  well  washed ;  the  carbonate  of  soda,  dissolved  hy  heat,  is  to  be  poured 
into  the  solution,  the  precipitate  allowed  to  subside,  the  clear  fluid  decanted,  and  the 
solid  matter  washed  upon  a  filter.  The  collected  solutions  are  neutral  chloride  of  soda. 
Sixty-two  parts  of  the  carbonate  of  soda  are  then  to  be  dissolved  in  the  remainder  of 
the  water,  and  added  to  the  preparation ;  the  whole  being  thus  filtered,  a  limpid  liquid 
is  obtained,  indicating  6°  by  the  hydrometer  of  Baum6. 

The  chloride  of  magnesia  was  long  a^o  proposed  by  Sir  H.  Davy  for  bleaching 
linen,  as  being  preferable  to  chloride  of  hme,  because  the  resulting  muriate  of  mag- 
nesia was  not  injurious  to  the  fibre  of  cloth,  as  muriate  of  lime  may  be,  under  certain 
circumstances.  I  prepared  a  quantity  of  chloride  of  magnesia,  by  exposing  a  hydrate 
of  that  earth  in  the  chlorine  chamber  of  a  large  manufactory  of  chloride  of  hme  at 
Glasgow,  and  obtained  a  compoimd  possessed  of  considerable  discolouring  powers; 
but  I  found  that  the  chlorine  was  so  feebly  saturated  by  the  base,  that  it  destroyed  the 
colours  of  fast-dyed  calicoes  as  readily  as  chlorine  gas  or  chlorine  water  did,  and  was 
therefore  dangerous  for  common  bleaching,  and  destructive  in  clearing  the  grounds  of 
printed  goods,  which  is  one  of  the  most  valuable  applications  of  the  calcareous  and 
alkaline  chlorides.  The  occasion  of  my  making  these  experiments  was  the  importation 
of  a  considerable  quantity  of  magnesite,  or  native  atomic  carbonate  of  magnesia,  from 
the  district  of  Madras,  by  an  enterprising  friend  of  mine.  Encouraged  by  the  enco- 
miums bestowed  on  the  chloride  of  magnesia  by  many  chemical  writers,  he  expected 
to  have  benefited  both  the  country  and  himself  by  bringing  home  the  earthy  base  of 
that  compound,  at  a  moderate  price ;  but  was  disappointed  to  his  cost 

Dr.  Thomson  is  of  opinion  that  the  bleaching  compound  of  lime  and  chlorine  is  not 
a  chloride  of  lime,  but  a  combination  of  chlorous  acid  with  lime  and  of  chlorine  with 
calcium :  consisting  in  its  most  concentrated  state  of 

3  atoms  of  chloride  of  calcium  =  21 
1  atom  of  chlorite  of  lime    -    =11 

S2 

So  that  about  one-third  of  the  weight  is  chlorite  of  lime,  to  which  alone  the  bleaching 
powers  of  the  substance  are  owing.  He  admits  a  fact,  rather  inconsistent  with  this 
opinion,  that  bleaching  powder  does  not  attract  moisture  from  the  atmosphere  with 
nearly  so  much  rapidity  as  might  be  expected  from  a  mixture  containing  two-thirds  of 
its  weight  of  so  deliquescent  a  salt  as  muriate  of  lime ;  unless  this  indeed  be  prevented 
by  the  chloride  and  chlorite  being  united  into  a  double  salt,  which  is  a  mere  conjecture 
without  either  proof  or  analogy.  And  further,  when  dilute  sulphuric  or  muriatic  acid 
is  poured  upon  bleaching  powder,  a  profusion  of  chlorine  is  given  out  immediately, 
which  he  also  admits  to  be  inconsistent  with  the  notion  of  its  being  a  mixture  of  chloride 
of  calcium  and  chlorite  of  hme,  for  no  such  evolution  takes  place  when  the  above  acids 
are  mixed  with  solutions  of  chloride  of  calcium  and  chlorate  of  potash.  Though  I  am 
of  opinion  that  bleaching  powder  is  simply  a  chloride  of  lime,  in  which  the  lime  cor- 
responds to  the  water  in  the  aqueous  chlorine,  yet  I  cannot  see  the  truth  or  apposite- 
ness  of  his  last  reason,  because  chlorine  is  certainly  given  out  when  chlorate  of  potash 
is  acted  upon  by  dUute  muriatic  acid,  as  any  man  may  prove  by  adding  to  a  mixture 
of  these  two  substances  a  vegetable  colour ;  for  it  will  be  speedily  blanched.  Dr.  Thom- 
son considers  the  chloride  which  is  at  present  made  in  Mr.  Tennant's  great  factory,  as 
containing  one  atom  of  chlorine  associated  with  one  atom  of  lime,  or,  taking  his  num- 
bers, as  consisting  of 

Hydrate  of  lime  4*625 

Chlorine  -  4*5 
or  nearly  equal  weights  of  the  chlorine  and  the  base ;  indicating  a  surprising  degree 
of  excellence  in  the  preparation.  The  average  commercial  samples  of  bleaching  pow- 
der from  different  factories  which  I  examined  some  years  ago,  did  not  possess  nearly 
that  strength  ;  but  varied  in  their  quantity  of  chlorine  from  20  to  28  per  cent  In  my 
synthetic  experiments  related  above,  the  greatest  quantity  of  chlorine  that  would  com- 
bine with  the  atomic  hydrate  of  lime  was  in  the  proportion  of  130  to  200;  but  there  v. 


CHLORINE  AND  ALKALL 


41S 


no  doubt  that,  if  the  lime  contains  additional  water,  it  will  condense  more  gas.  I  have 
never  seen  a  chloride  of  lime  of  the  strength  mentioned  by  Dr.  Thomson,  and  I  should 
think  there  must  be  some  fallacy  in  his  statements.  I  have  recorded  in  the  paper  above 
quoted  an  experiment  which  proves  that,  with  additional  moisture,  a  chloride  of  lime 
may  be  obtained  of  the  following  composition : — 

Chlorine  39-5 

Lime     -  39  9 

Water  -  20-6 


100-0 


In  the  article  BLEAcmNO,  of  the  Encyclopaedia  Britannica,  Dr.  Thomson  deduces, 
from  a  test  trial  of  Mr.  Crum,  that  the  best  bleaching  powder  is  a  compound  of  1  atom 
chlorite  of  lime  =  11,  3  atoms  chloride  of  calcium  =  21,  and  3  atoms  of  water  =  9. 
"  But,"  adds  he,  "  in  general  the  whole  lime  is  not  accurately  saturated  with  chlorine. 
Accordingly,  when  the  bleaching  powder  is  dissolved  in  water  a  small  residue  almost 
always  remains  undissolved.  Unless  the  powder  be  fresh  made,  a  portion  of  chlorite 
is  always  converted  into  chloride  of  calcium.  It  is  probable,  therefore,  that  the  best 
bleaching  powder,  as  it  comes  into  the  hands  of  the  bleachers,  consists  of 

1  atom  chlorite  of  lime      -    11 

3  atoms  chloride  of  calcium  21 

6  atoms  water  -        -        -       6*75 
Impurity        -        .        -      2*25 

41-00 


"  If  we  consider  the  bleaching  powder  as  a  compound  of  chlorine  and  lime,  our  mode  of 
calculating  will  not  be  altered.  Instead  of  1  atom  chlorite  of  lime,  and  3  atoms  chloride 
of  calcium,  we  shall  have  4  atoms  chloride  of  lime,  6  atoms  water,  and  225  of  impurity 
as  before,"  In  such  ambiguity  does  this  able  chemist  place  this  interesting  compound, 
for  theoretical  reasons,  of  which  I  cannot  see  the  value.  Surely  there  is  no  difficulty  in 
conceiving  chlorine  to  exercise  a  direct  attractive  force  towards  the  hydrate  of  lime,  as  it 
is  known  to  do  towards  each  of  its  elementary  constituents,  the  oxygen  and  the  calcium. 
Such  refinements  as  the  preceding  tend  merely  to  mystify  a  plain  matter.  Even  the 
chlorous  acid  here  brought  into  play  to  form  the  ideal  chlorite,  is  by  his  own  admission 
a  hypothetical  being.  "  When  chlorate  of  potash,"  says  Dr.  Thomson,  "  is  mixed  with 
sulphuric  acid,  and  made  into  small  balls  the  size  of  a  pea,  if  we  expose  these  balls  to  a 
heat  somewhat  lower  than  that  of  boiling  water,  a  bright  yellowish  green  gas  separates, 
which  may  be  received  over  mercury.  Its  smell  is  peculiar  and  aromatic  Water  absorbs 
at  least  seven  times  its  volume  of  it    It  destroys  vegetable  blues.     Its  constituents  are, 

1  volume  chlorine  2-6      or  4-5 

2  volumes  oxygen  2'222  or  4. 

Thus  this  compound  consists  in  weight  of  chlorine  4-5,  oxygen  4  =  8'5.  It  has  been 
called  quateroxide  of  chlorine,  but  it  is  more  probably  a  teroxide.  It  has  been  supposed 
by  some  to  possess  acid  properties,  and  has  therefore  been  called  chlorous  acid.  But 
this  is  only  as  yet  a  hypothesis. 

Surely  this,  by  the  doctor's  own  showing,  is  very  slender  authority  for  renouncing  our 
long-received  doctrines  concerning  the  constitution  of  bleaching  powder.  I  shall  con- 
clude by  remarking  that  the  ultra-atomists  are  now  in  a  dilemma  about  this  substance ; 
M.  Welter,  and  many  French  chemists,  calling  it  a  sub-chloride  of  1  atom  of  chlorine 
to  2  atoms  of  lime,  and  Dr.  Thomson  showing  that  Mr.  Tennant,  the  greatest  and  best 
manufacturer  of  it,  has  produced  it  in  the  state  of  a  chloride,  or  1  atom  of  each.  The 
fact  is,  in  chloride  of  lime,  as  in  water  of  ammonia,  alcohol,  and  muriatic  acid,  there 
is  no  mfficient  reason  for  definite  proportion  in  any  term  short  of  saturation,  and  there- 
fore we  shall  find  that  chloride  in  every  gradation  of  strength  from  1  per  cent  of 
chlorine  up  to  40  per  cent — the  strongest  which  I  succeeded  in  preparing,  though  I 
passed  a  constant  stream  of  chlorine  in  great  excess  over  a  pure  hydrate  of  lime  for 
upwards  of  24  hours,  with  frequent  renewal  of  the  surface  ;  indeed,  till  it  refused  to 
absorb  any  more  gas,  as  indicated  by  its  remaining  stationary  in  weight 

CHLOKINE  AND  ALKALI  {Manufacture  of).  Mr.  Tennant  Dunlop  of  Glasgow 
obtained,  in  March,  1847,  a  patent  for  an  improved  method  of  producing  chlorine.  The 
process  he  usually  adopts  is  to  bring  together  common  salt,  nitrate  of  soda,  or  nitric  acid 
and  sulphuric  acid,  in  suitable  proportions ;  heat  being  then  applied,  chlorine  or  an 
oxide  of  azote  and  muriatic  acid  are  evolved ;  these  gases  are  caused  to  pass  through 
a  condenser  charged  with  sulphuric  acid  of  sufficient  strength  to  absorb  the  oxide  of 
azote ;  and  then  the  chlorine  and  muriatic  acid  are  separated  by  means  of  water. 

In  applying  the  product  resulting  from  the  above  process,  he  obtains  nitric  acid  from 


i 


j! 


re 


414 


CHLOROMETRY. 


CHOCOLATE. 


415 


the  sulphuric  acid  charged  with  oxide  of  azote,  which  is  true  nitrous  sulphuric  acid. 
This  is  effected  by  the  aid  of  atmospheric  air,  steam,  and  water.  He  introduces  the 
nitrous  sulphuric  acid  into  a  suitable  vessel,  and  by  the  addition  of  water  and  heat,  he 
effects  the  disengagement  of  oxide  of  azote,  which  being  caused  to  traverse  a  condenser 
with  a  sufficient  quantity  of  air  and  steam  or  water,  is  by  this  means  transformed  into 
nitric  acid-  This  acid  may  be  again  used  in  the  manufacture  of  chlorine,  and  again 
recovered,  and  so  on.  Sometimes,  instead  of  treating  the  nitrous  sulphuric  acid  as  just 
described,  the  patentee  causes  the  oxide  of  azote  to  be  evolved,  and  to  pass  into  a  cham- 
ber into  which  a  current  of  sulphuretted  hydrogen  is  streaming;  by  which  means 
sulphate  of  ammonia  is  obtained  and  sulphur  deposited. 

CHLOROMETRY ;  Chlorometrie,  is  the  name  given  by  the  French  to  the  process  for 
testing  the  decoloring  power  of  any  combination  of  chlorine,  but  especially  of  the  com- 
mercial articles,  the  chlorides  of  lime,  potash,  and  soda.  M.  Gay  Lussac  proposed  many 
years  ago  the  following  graduated  method  of  applying  indigo  to  this  purpose.  As  indigo 
varies  much  in  its  dyeing  quality,  and  of  consequence  in  the  proportion  of  chlorine  re- 
quired for  its  decoloration,  he  assumes  as  the  unity  of  blanching  power,  one  litre  of  chlo- 
rine gas,  measured  at  the  mean  pressure  of  29'6  inches,  and  at  the  temperature  of  melting 
ice.  This  volume  of  gas,  when  combined  with  a  determinate  quantity  of  water,  is  em- 
ployed tu  test  the  standard  solution  of  indigo.  For  this  purpose  a  solution  in  sulphuric 
acid  of  any  sample  of  indigo  is  taken,  and  diluted  with  water  to  such  a  degree  that  10 
measures  of  it,  in  a  graduated  tube,  are  decolored  by  that  one  measure  of  combined  chlo- 
rine gas.  Each  measure  of  indigo  solution  so  destroyed  is  called  a  degree,  and  this  meas- 
ure being  divided  into  five  parts,  the  real  test  of  chlorine  is  given  to  fiftieths,  which  is 
sufficiently  nice.  For  the  standard  of  the  assays,  a  chloride  of  lime  as  pure  and  fully 
saturated  as  possible  is  taken,  and  dissolved  in  such  a  quantity  of  water,  that  the  solution 
shall  contain,  or  be  equivalent  to,  one  volume  of  chlorine  gas.  Calculation  proves  that 
this  condition  is  exactly  fulfilled  by  dissolving  4938  grammes  of  the  said  chloride  in  half  a 
litre  of  water ;  or  in  English  measures,  5  gr.  very  nearly  in  500  grain  measures  cf  water. 
This  solution,  which  serves  for  a  type,  indicates  10°  in  the  assay,  or  proof;  that  IS  to  say, 
each  single  volume  destroys  the  color  of  10  volumes  of  the  dilute  indigo  solution.  It  may 
be  remarked  that  a  greater  degree  of  precision  is  in  general  attainable  with  a  weak  so- 
lution of  chlorine  or  a  chloride,  for  example  at  4°  or  5°,  than  with  one  much  stronger; 
consequently  if,  after  a  preliminary  trial,  the  standard  considerably  exceeds  10°,  a  given 
Tolume  of  water  must  be  added  to  the  solution,  and  then  the  above  proof  must  be  taken. 
If  the  volume  of  water  added  was  double,  the  number  of  degrees  afterward  found  must 
be  tripled,  to  obtain  the  true  title  of  the  chloride.  It  is,  however,  to  be  observed  that 
the  degree  of  decoloration  varies  with  the  time  taken  in  making  the  mixture ;  the  more 
slowly  the  chlorine  is  added  to  the  indigo,  the  less  of  it  escapes  into  the  atmosphere, 
and  the  more  effective  it  becomes  in  destroying  the  color.  The  best  mode  of  ob- 
taining comparable  results,  is  to  pour  suddenly  into  the  test  quantity  of  chlorine  the 
whole  volume  of  tne  indigo  solution  likely  to  be  decolored ;  but  it  is  requisite  to  find  ap- 
proximately beforehand,  what  quantity  of  indigo- blue  will  probably  be  destroyed. 
When  it  comes  to  the  verge  of  destruction,  it  is  green ;  but  yellowish-brown  when  en- 
tirely decom[>osed. 

I  have  tried  the  indigo  test  in  many  ways,  but  never  could  confide  in  it.  The  sulphu- 
ric solution  of  indigo  is  very  liable  to  change  by  keeping,  and  thus  to  lead  to  erroneous 
results.  The  method  of  testing  the  chlorides  by  green  sulphate  of  iron,  described  imder 
bleaching,  is  in  my  opinion  preferable  to  the  above. 

M .  Gay  Lussac  has  rece.itly  proposed  another  proof  of  chlorine,  founded  on  the  same 
pnnciple  as  that  by  green  vitriol,  namely,  the  quantity  of  it  requisite  to  raise  a  metallic 
substance  from  a  lower  to  a  higher  stage  of  oxydizement.  He  now  prescribes  as  the 
preferable  plan  of  chlorometry,  to  pour  very  slowly  from  a  graduated  glass  tube,  % 
standard  solution  of  the  chloride,  to  be  tested  upon  a  determinate  quantity  of  arsenious 
acid  dissolved  in  muriatic  acid,  till  the  whole  arsenious  be  converted  into  the  arsenic 
acid-  The  value  of  the  chloride  is  greater  the  less  of  it  is  required  to  produce  this  effect 
It  is  easy  to  recognise,  by  a  few  drops  of  solution  of  indigo,  the  instant  when  all  the 
arsenious  acid  has  disappeared ;  for  then  the  blue  tint  is  immediately  effaced,  and  can- 
not be  restored  by  the  addition  of  a  fresh  drop  of  indigo  solution. 

In  graduating  the  arsenical  chlorometer,  M.  Gay  Lussac  takes  for  his  unity  the  de- 
colouring power  of  one  volume  of  chlorine  of  32<>  Fahr.,  and  divides  it  into  100  parts. 
Suppose  that  we  prepare  a  solution  of  chlorine  containing  its  own  volume  of  the  gas,  and 
an  arsenious  solution,  such  that,  under  a  like  volume,  the  two  solutions  shall  recipro- 
cally destroy  each  other.  Let  us  call  the  first  the  normal  solution  of  chlorine,  and  the 
second,  the  normal  arsenious  solution.  "We  shall  fix  at  10  grammes  the  weight  of  chlo- 
ride of  lime  subjected  to  trial ;  and  dissolve  it  in  water,  so  that  the  total  volume  of  the 
solution  shall  be  a  litre  (1000  grammes  measure,)  including  the  sediment  If  we  take 
a  constant  volume  of  this  solution,  10  centimetres  cube  (10  gramme  measures,)  for  ex- 
ample, divided  into  100  equal  parts,  and  pour  into  it  gradually  the  arsenious  solution 


r 


(measured  by  like  portions),  till  the  chlorine  be  destroyed,  the  bleaching  power  will 
be  proportional  to  the  number  of  portions  of  the  arsenious  solution,  which  the  chloride 
shall  have  required.  If  the  chloride  has  destroyed  100  portions  of  the  arsenious  solution, 
its  title  will  be  100 ;  if  it  has  destroyed  80  portions,  its  title  will  be  80,  Ac,  and  so  forth. 
On  pounng  the  acidulous  arsenious  solution  into  the  chloride  of  lime,  this  will  become 
very  acid  ;  the  chlorine  will  be  emitted  abundantly,  and  the  proof  will  be  quite  incorrect. 
If,  on  the  contrary,  we  pour  the  solution  of  the  chloride  of  lime  into  the  arsenious  solu- 
tion, this  evil  will  not  occur,  since  the  chlorine  will  always  find  plenty  of  arsenious  acid 
to  act  upon,  whatever  be  the  dilution  of  the  one  or  the  other ;  but  in  this  case,  the  stand- 
ard of  the  chlorine  is  not  given  direcily,  as  it  is  in  the  inverse  ratio  of  the  number  of 
portions  which  are  required  to  destroy  the  measures  of  the  arsenious  solution.  If  50 
portions  of  the  chloride  have  been  required,  the  proof  will  be  lOOX^— — ^=200°-  if  200 
have  been  required,  the  proof  will  be  100X-^g=50°,  &c.  This  evfl**is  not,  however, 
▼ery  serious,  since  we  have  merely  to  consult  a  table,  in  which  we  can  find  the  proof 
corresponding  to  each  volume  of  the  chloride  employed  for  destroying  the  constant 
measure  of  the  arsenious  solution.  The  arsenious  solution  should  be  slightly  tinged  with 
sulphate  of  indigo,  so  as  to  show,  by  the  disappearance  of  the  color,  the  precise  point  or 
instant  of  its  saturation  with  chlorine,  that  is,  its  conversion  into  arsenic  acid.  If  the 
arsenious  acid  be  pure,  the  normal  solution  may  be  made  directly  by  dissolving  4*439 
grarnmes  of  it  in  muriatic  acid  (free  from  sulphurous  acid),  and  diluting  the  solution 
till  it  occupies  one  litre,  or  1000  grammes  measure,  jinnales  de  Chimie  et  Phvsiaue 
LX.  225.  *    ^    ' 

CHOCOLATE  is  an  alimentary  preparation  of  very  ancient  use  in  Mexico,  from 
which  country  it  was  introduced  into  Europe  by  the  Spaniards  in  the  year  1520,  and  by 
them  long  kept  a  secret  from  the  rest  of  the  world.    Linnaeus  was  so  fond  of  it'  that  he 
gave  the  specific  name,  theobroma^  food  of  the  gods,  to  the  cacao-tree  which  produced 
it.     The  cacao-beans  lie  in  a  fruit  somewhat  like  a  cucumber,  about  5  inches  long  and 
3|  thick,  which  contains  from  20  to  30  beans,  arranged  in  5  regular  rows  with  parti- 
tions between,  and  which  are  surrounded  with  a  rose-colored  spongy  substance    like 
that  of  water-melons.    There  are  fruits,  however,  so  large  as  to  contain  from  40 'to  50 
beans.    Those   grown  in   the  West  India  islands,  Berbice  and  Demarara,  are  much 
smaller,  and  have  only  from  6  to  15;  their  development  being  less  perfect  than  in 
South  America.     After  the  maturation  of  the  fiuit,  when  their  green  color  has  chan^^ed 
to  a  dark  yellow,  they  are  plucked,  opened,  their  beans  cleared  of  the  marrowy  sub- 
stance, and  spread  out  to  dry  in  the  air.      Like  almonds,  they  are  covered  with  a  thin 
skin  or  husk.     In  the  West  Indies  they  are  immediately  packed  up  for  the  market 
when  they  are  dried ;  but  in  the  Caraccas  they  are  subjected  to  a  species  of  slight  fer- 
mentation, by  putting  them  into  tubs  or  chests,  covering  them  with  boards  or  "stones 
and  turning  them  over  every  morning,  to  equalize  the  operation.     They  emit  a  good 
deal  of  moisture,  lose  the  natural  bitterness  and  acrimony  of  their  taste  by  this  process 
as  well  as  some  of  their  weight.     Instead  of  wooden  tubs,  pits  or  trenches  dug  in  the 
ground  are  sometimes  had  recourse  to  for  curing  the  beans ;  an  operation  called  earthine 
(terrer).    They  are  lastly  exposed  to  the  sun,  and  dried.    The  latter  kind  are  reckoned 
the  best ;  being  larger,  rougher,  of  a  darker  brown  color,  and,  when  roasted,  throw  off 
their  husk  readily,  and  split  into  several  u-regular  fragments ;  they  have  an  agreeable 
mild  bitterish  taste,  without  acrimony.    The  Guiana  and  West  India  sorts  are  "smaller 
flatter,  smoother-skinned,  lighter-colored,  more  sharp  and  bitter  to   the  taste.    They 
answer  best  for  the  extraction  of  the  butter  of  cacao,  but  afford  a  less  aromatic  and 
agreeable  chocolate.     According  to  Lampadius,  the  kernels  of  the  West  India  cacao 
beans  contain,  in  100  parts,  besides  water,  53' 1  of  fat  or  oil,  16-7  of  an  albuminous 
brown  matter,  which  contains  all  the  aroma  of  the  bean,  10-91  of  starch,  7|  of  gum  or 
mucilag^  0-9of  lignine,  and  201  of  a  reddish  dye  stuff  somewhat  akin  to  the  pigment  of 
cochineal     The  husks  form  12  per  cent  of  the  weight  of  the  beans ;  they  contain  no  fat 
V  t  ^^^^^^^  hgnine,  or  woody  fibre,  which  constitutes  half  their  weight,  thev  yield  a 
light  brown  mucilaginous  extract  by  boiling  in  water.     The  fatty  matter  is  of  the  con- 
sistence of  tallow,  white,  of  a  mild  agreeable  taste,  called  butter  of  cacao,  and  not  apt  to 
turn  rancid  by  keeping.     It  melts  only  at  122°  Fahr.,  and  should,  therefore,  make  t')ler- 
able  candles.     It  is  soluble  in  boiling  alcohol,  but  precipitates  in  the  cold.     It  is 
obtained  by  exposing  the  beans  to  strong  pressure  in  canvas  bags,  after  they  have  been 
steamed  or  soaked  in  boiling  water  for  some  time.     From  5  to  6  ounces  of  butter  may 
be  thus  obtained  from  a  pound  of  cacao.     It  has  a  reddish  tinge  when  first  expressed, 
but  It  becomes  white  by  boiling  with  water. 

The  beans,  being  freed  from  all  spoiled  and  mouldy  portions,  are  to  be  gently  roasted 
over  a  fire  in  an  iron  cylinder,  with  holes  in  its  ends  for  allowing  the  vapours  to  escape : 
the  apparatus  being  similar  to  a  coffee-roaster.  When  the  aroma  begins  to  be  well 
developed,  the  roasting  is  known  to  be  finished;  and  the  beans  must  be  turned  out 
cooled,  and  freed  by  fanning  and  sifting  from  their  husks.    The  kernels  are  then 


W 
II 


I 


i: 


ii 


iH4. 


II 


41« 


CHOCOLATE. 


to  be  converted  into  a  paste,  either  by  trituration  ma  ^^J^^l^^^ff^^  ^ILLuy 
by  the  following  ingenious  and  powerful  machine  The  «^«««^^,*\P^^J..*^*y'"*"y 
iZprance  a  little  vanilla  incorporated  with  it,  and  ^«o^«f  jf  f^^nd  Inl  a  haK  of 
which  varies  from  one-third  of  its  weight  to  equal  part^  For  a  pound  ^^^  ^^aH  ol 
cacao,  one  pod  of  vanilla  is  sufficient,  Chocolate  paste  improves  "»jf«  A^^^  ^^J 
keeping,  and  should  therefore  be  made  in  large  quantities  at  a  time.  But  the  roastea 
beans  soon  lose  their  aroma,  if  exposed  to  the  air. 


C 


CI 


czn 


^p 


I  .  I 


jnn 


cun 


m 


m 


ruL 


] 


Fi<'.  357  represents  the  chocolate  mill.     Upon  the  sole  a,  made  of  marble,  six  conical 
rollers  b  b,  are  made  to  run  by  the  revolution  of  the  upright  axis  or  shaft  q,  dnven  bv 
the  agency  of  the  fly  wheel  e  and  bevel  wheels  i  k.     The  sole  A  rests  upon  a  strong 
iron  plate!  which  is  heated  by  a  small  stove,  introduced  at  the  door  h.     The  wooden 
frame  work  r,  forms  a  ledge,  a  few  inches  high,  round  the  marble  slab,  to  confine 
the  cocoa  ia  the  act  of  trituration,     c  is  the  hopper  of  the  mill  through  which  the 
roasted  beans  are  introduced  to  the  action  of  the  rollers,  passing  first  into  the  flat 
▼esse!  p,  to  be  thence  evenly  distributed.      After  the  cacao  has  received  the  first  tritura- 
tion, the  paste  is  returned  upon  the  slab,  in  order  lo  be  mixed  with  the  proper  quantity 
ofsisar,  and  vanilla,  previously  sliced  and  ground  up  with  a  little  hard  sugar.     When 
the  chocolate  is  sufficiently  worked,  and  while  it  is  thin  with  the  heat  and  trituration. 
It  must  be  put  carefully  into  the  proper  moulds.     If  »"tf?^»ced  too  warm,  it  will  be 
apt  to  become  damp  and  dull  on  the  surface ;  and,  if  too  cold,  it  will  not  take  the  proper 
form.    It  must  be  previously  well  kneaded  with  the  hands,  to  ensure  the  expulsion  of 
everv  air  bubble.  .    .  .,^„  __. 

In  Barcelona,  chocolate  mills  on  this  construction  are  very  common,  t>ut  they  are 
turned  bv  a  horse-dn  set  to  work  in  the  under  story,  corresponding  to  H  in  the  aDove 
figure.  The  shaft  g  is,  in  this  case,  extended  down  through  the  marble  slab,  and  is 
surrounded  at  its  centre  with  a  hoop  to  prevent  the  paste  coming  into  contact  with  it 
Each  of  these  horse-mills  turns  out  about  ten  pounds  of  fine  chocolate  in  the  hour,  from 
a  slab  two  feet  seven  inches  in  diameter.  •     <.     j    r  *v 

Chocolate  is  flavoured  with  cinnamon  and  cloves,  in  several  countries,  instead  ot  the 
more  expensive  vanilla.  In  roasting  the  beans  the  heat  should  be  at  first  ver>'  slow  to 
eive  time  to  the  humidity  to  escape;  a  quick  fire  hardens  the  surface,  and  injures  the 
process.  In  putting  the  paste  into  the  tin  plate,  or  other  moulds  it  must  be  weU 
shaken  down  to  insure  its  filling  up  all  the  cavities,  and  giving  the  sharp  and  polished 
impression  so  much  admired  by  connoisseurs.  Chocolate  is  sometimes  adulterated 
with  starch  :  in  which  ease  it  will  form  a  pasty  eonsistenced  mass  when  treated  with 
boilimr  waiter.  The  harder  the  slab  upon  which  the  beans  are  triturated,  the  better ; 
and  thence  porphyry  is  far  preferable  to  marble.  The  grinding  rollers  of  the  mill 
should  be  made  of  iron,  and  kept  very  clean.  i    •     v 

About  eight  years  ago,  samples  of  chocolate  were  sent  to  me  for  analysis    by 
order  of  the  Lori  of  the  Admiralty.     It  was  made  at  the  victualling-yard  Deptford 
for  the  use  of  the  Royal  Navy,  by  the  government  chocolate  mills,  where  about 


CHOCOLATE. 


417 


400  tons  are  annually  prepared,  to  be  distributed  to  the  sailors  and  convicts  at  the 
rate  of  an  ounce  daily,  and  to  be  used  at  their  breakfast.     After  taking  the  said  choco- 
late for  some  time,  men   in   several   ships  complained   of  its  occasioning  sickneae. 
vomiting  purging,  and  more  serious  maladies,  terminating  in  a  few  cases  fatally     I 
examined  it  with  great  care,  but  could  find  no  injurious  ingredient  in  it,  and   no 
chemical  alterations  from  the  beans  of  the  Guyaquil  coco  from  which  it  was  manu- 
factured.    But  I  observed  that  it  consisted  of  gritty  grains,  from  very  imperfect  tri- 
turation  or  miHing ;  that  these  grains  were  quite  immiscible  with  water,  like  so  much 
tone  gravel ;  that  they  contained  many  sharp  spicule  of  the  coco-bean  husks,  and  that 
hence,  when  swallowed,  they  were  calculated  to  form  mechanically  irritating  lodg- 
Zlltr  ^*^\^^"«««  coats  of  the  stomach  and  bowels,  whereby  they  could  produce  the 
^n^\i  ^^^""^  certified  bj  several  naval  surgeons.     It  was,  moreover,  obvious  that, 
from  the  insoluble  condition  of  the  chocolate,  it  could  be  of  little  use  as  an  article  of 
lood  or  as  a  demulcent  substitute  for  milk,  and  that,  in  fact,  three-fourths  of  it  were, 
on  this  account,  an  ineffective  article  of  diet,  or  were  wasted 

Having  reported  these  results  and  opinions  to  the  Lords  of  the  Admiralty,  they 
were  pleased  after  a  few  weeks'  consideration,  to  request  me  to  go  down  to  the  vi^ 
tualJinff-yard  at  Deptford  and  superintend  the  preparation  of  a  quantity  of  chocolate 
in  the  best  manner  I  could  with  the  means  there  provided.     I  accordingly  repaired 
thither  on  the  13th  September,  1842,  and  experienced  the  utmost  courtesy  and  co- 
operation from  Sir  John  Hill,  the  Captain  Superintendent,  and  his  subordinate  officers: 
Ihe  coco-beans  had  been  hitherto  milled,  after  a  slight  roasting  upon  the  sole  of  an 
oat-kUn,  along  with  their  husks.     As  I   was  satisfied,  from  analysis,  that  the  husks 
were  no  better  food  than  saw-dust,  and  that  they  might  cause  irritation  by  their  minute 
spiculae  left  after  grinding  between  rotating  millstones,  I  set  about  a  plan  for  shelling 
them,  but  could  find  no  piece  of  apparatus  destined  for  the  purpose.     There  was,  how- 
ever,  a  pea-shelling  mill,  which  had  been  used  only  for  one  day  some  years  before  and 
Had  stood  ever  since  idle*  which,  on  being  cleaned  and  having  its  millstones  placed  at 
a  proper  distance,  was  found  to  answer  pretty  welL     The  beans  for  experiment,  to  the 
amount  of  6  cwt,  had  been  previously  roasted,  under  my  care,  at  a  well-regulated 
heat,  with  much  stirring,  in  the  oat-kiln;  and,  on  being  cold,  were  run  through  the 
siieliing  mill,  which  was  put  in  communication  with  the  fanners  of  the  flour  mUL 
15y  this  arrangement,  the  coco-beans  were  tolerably  shelled,  and  the  kernels  separated 
trom  their  scaly  husks.     The  weighings  were  accurately  made. 


6  cwt.  of  the  Guyaquil  coco 
Lost  in  roasting 
shells 
waste 

Remained  for  milling 


672  lbs. 


555 


On  the  14th  September  I  made  a  report  to  the  Lords  of  the  Admiralty  upon  the 
experiments  of  the  13th,  of  which  the  following  is  an  outline.  After  describing  the 
pains  taken  to  regulate  the  roasting  temperature,  and  to  equalize  the  effect  upon  the 
beans  by  moving  them  occasionally  by  a  rake,  I  stated  that  the  oat-kiln  was  not  well 
adapted  to  the  purpose  of  roasting  the  coco,  because  it  was  impossible  to  turn  the  beans 
regularly  and  continuously  during  the  process,  so  that  they  could  not  be  equally  roasted 
and  because  it  was  an  unwholesome  operation  for  the  workmen,  who  must  go  into  a 
chamber  filled  with  noxious  gases  and  fumes,  to  use  the  rakes.  When  the  door  of  the 
kiln  was  shut,  to  allow  the  burned  air  from  the  fire  below  to  draw  up  through  it,  mischief 
might  be  done  to  the  stratum  of  coco  on  the  sole,  and  when  the  door  was  again  opened 
to  permit  a  person  to  go  in  and  stir,  time  and  heat  were  wasted  in  replenishing  the 
chamber  with  fresh  air.  I  understood  that  a  revolving-cylinder-roasting  machine  had 
been  made  by  Messrs.  Rennie  for  the  chocolate  process  at  Deptford;  but,  for  reasons 
unknown  to  me,  it  had  never  been  employed. 

The  diminution  of  weight  by  roasting  and  sheUing  may  be  estimated  at  about  11 
per  cent  A  part  of  this  loss  is  moisture,  which  should  be  completely  expeUed,  to 
prevent  its  causing  the  chocolate  to  become  mouldy  at  sea.  But  a  part  of  the  defal- 
cation was  also  due  to  some  of  the  coco  remaining  in  the  crevices  of  the  pea-splitting 
mill  and  the  fanners,  which  would  not  be  observable  if  these  were  in  constant  employ- 
ment. I  think,  therefore,  that  the  roasted  kernels  may  be  estimated  in  general  at  85 
per  cent  of  the  raw  beans. 

J^g.  368  represents  the  chocolate  mills  at  the  victualling-yard,  Deptford,  as  mounted 

r  *  ?  i?^v^°"°?  *^**  ^"  *°  '^*''"  "^'"^  ^'^Pt  ^tter  at  sea  than  tha  split  peas,  and  thej  were  also  pra- 
terred  by  the  sailors  in  their  natural  state.  *-      r      »  j  r 

Vol.  L  8H 


I 


!! 


t 


418 


CHOCOLATK 


CHOCOLATE. 


bv  the  celebrated  engineers,  Messrs.  Rennie.  There  are  four  double  mill-stonet 
A.  B.  c  D  each  three  feet  in  diameter,  of  which  the  nether  rests  upon  a  bed  of  cast  iron, 
like  a  drum-head,  kept  at  the  temperature  of  about  220°  by  the  admission  of  steam 
to  the  case  below.  Over  each  mill  there  is  a  feeding-hopper  1,  2,  3,  4,  in  conamu- 
nication  by  the  pipes  6,  6,  1,  8,  with  the  general  reservoir  e,  charged  «Pon  the  floor 
above  with  cocoa  through  the  funnel  placed  over  it  The  vertical  shafts  which  turn 
these  mnis  are  marked  f,  g,  h,  l;  they  are  moved  by  the  train  of  bevel-wheels  above, 
which  are  driven  by  an  arm  from  the  main  shaft  of  the  steam  engine.  JiAch  miU  can, 
of  course,  be  thrown  in  and  out  of  geer  at  pleasure.    At  i,  i,  i,  i,  the  discharge-spout 


419 


U  Rhown  which  pours  out  the  semi-fluid  hot  chocolate  into  shallow  cylindrical  tm  pan^ 
^mibTe  if  contaiUg  about  nine  pounds  of  chocolate  each.  These  four  mil  s  are  capable 
;?Werting  upwards  of  a  ton  of  coco  into  good  chocolate  in  a  day.  on  the  system  of 
double  triJufatU  which  I  adopted,  and  two  tons  on  the  former  rough  plan  I  found 
th^t  the  two  stones  of  each  mill  had  been  placed  so  far  asunder  as  would  allow  entire 
Ws  t^  pl^  through,  as  spurious  chocolate,  at  one  operation ;  but  the  chocolate  thus 
Sar^e^Tas  in  a  fe^y  gritty  state,  whereas  good  chocolate  m  the  liquefied  state  should 


be  smooth  and  plastic  between  the  fingers,  and  spread  upon  the  tongue  without  leaving 
any  granular  particles  in  the  mouth.  To  obtain  such  a  result^  I  divided  the  milling 
into  two  steps ;  for  the  first,  two  pairs  of  the  stones,  a  and  c^  were  set  as  close  together 
as  for  a  paint  mill  (which  they  closely  resemble),  and  the  other  two  pairs,  b  and  d, 
were  left  at  their  ordinary  distance.  The  paste  obtained  from  the  first  set  was  trans^ 
ferred,  while  nearly  liquid,  into  the  hoppers  of  the  second  pairs,  from  which  it  issued  at 
the  spouts  as  thin  and  smooth  as  honey  from  the  comb.  In  subserviency  to  these  ex- 
periments, I  made  an  analysis  of  the  Guyaquil  coco,  which  I  found  to  be  composed  a« 


Concrete  fat  or  butter  of  coco,  dissolved  out  by  ether 

Brown  extractive,  extractible  by  hot  water,  after  the  operation  of  ether 

Ligneous  matter,  with  some  albumine       -  -  .  .  . 

Shells 

Water 

Loss  -.--..._ 


87 
10 
80 
14 
6 
3 


100 


Tlie  solid  fat  of  the  coco  should  be  most  intimately  combined  by  milling  with  the 
extractive  albumine,  and  ligneous  matter,  in  order  to  render  it  capable  of  forming  an 
emulsion  with  water ;  and,  indeed,  on  account  of  the  large  proportion  of  concrete  fat 
in  the  beans  some  additional  substance  should  be  introduced  to  facilitate  this  emulsive 
union  of  the  fat  and  water.  Sugar,  gum,  and  starch  or  flour  are  well  adapted  for  this 
purpose. 

Under  this  conviction,  I  employed  in  the  first  of  these  trials  at  Deptford,  made 
with  one-half  of  the  above  roasted  keniels  =  277i  lbs.,  6  per  cent  of  sugar,  which  waa 
first  mixed  upon  a  board  with  shovels,  and  the  mixture  was  then  put  progressively  into 
tlie  hoppers  of  the  two  mills  b  and  d.  The  paste  which  ran  out  of  their  spouts  was 
immediately  poured  into  the  hoppers  of  a  and  c,  from  which  it  flowed  smooth  and  very 
thin  into  the  concreting  pans.  The  sugar  supplied  to  me  was  exceedingly  moist^ 
whereas  it  ought  to  be  dry,  like  the  bag  sugar  of  the  Mauritius.  The  other  half 
of  the  coco  kernels  was  milled  alone  once  by  the  ordinary  mills  b  and  d.  I  sub- 
jected next  day  samples  of  these  two  varieties  of  chocolate  to  the  following  examina- 
tion, and  compared  them  with  the  sample  of  chocolate  as  usually  made  at  Deptford, 
as  also  with  a  sample  of  chocolate  sold  by  a  respectable  grocer  in  London.  A  like 
quantity  of  these  four  samples  was  treated  with  eight  times  its  weight  of  boiling  water, 
the  diffusion  well  stirred,  and  then  left  to  settle  in  a  conical  wineglass.  Of  the  ordi- 
nary Deptford  coco,  four-fifths  rapidly  subsided  in  coarse  grains,  incapable  of  forming 
any  thing  like  an  emulsion  with  water,  and  therefore  of  little  or  no  avail  in  making  a 
breakfast  beverage. 

1.  The  single-milled  chocolate  made  under  my  direction  formed  a  smoother  emul- 
sion than  the  last,  on  account  of  the  absence  of  the  coco  husks ;  but  its  particles  were 
giitt}',  and  subsided  very  soon. 

2.  The  sugar  double-milled  chocolate,  on  the  contrary,  formed  a  milky-looking 
emulsion,  which  remained  nearly  uniform  for  some  time,  and  then  let  fall  a  soft 
mucilaginous  deposit,  free  from  grittiness. 

3.  The  shop  chocolate  formed  a  very  indifferent  emulsion,  though  it  was  well  milled, 
because  it  contained  evidently  a  large  admixture  of  a  coarse  branny  flour,  as  is  too 
generally  the  case. 

I  have  given  small  samples  of  the  above  No.  2.  chocolate  to  various  persons,  and 
they  have  considered  it  superior  to  what  is  usually  sold  by  our  grocers.  The  presence 
of  dry  sugar  in  chocolate  would  also  give  it  a  conservative  quality  at  sea,  and  prevent 
it  from  getting  musty. 

The  Lords  of  the  Admiralty,  after  seeing  the  above  two  samples  of  chocolate  and 
my  report  thereupon,  were,  about  six  weeks  afterwards,  pleased  to  request  me  to  make 
at  Uieir  victualling-yard  further  experiments  in  the  preparation  of  chocolate ;  and  they 
indicated  two  modes,  one  of  milling  twice  with  the  husks,  and  another  of  milling  twice 
without  the  husks ;  permitting  me,  at  the  same  time,  to  mill  a  portion  of  the  kernels 
with  10  per  cent  of  sugar,  and  a  second  portion  of  the  kernels  with  5  per  cent  of  sugar 
and  6  per  cent  of  the  excellent  flour  used  in  making  the  biscuits  for  the  royal  navy. 
On  the  24th  October,  1842,  I  accordingly  performed  these  experiments  upon  12  cwt^ 
of  Guyaquil  coco  as  carefully  roasted  as  possible  on  the  kiln. 

The  loss  in  drying  and  slightly  roasting  the  1344  lbs.  of  beans  was  6  per  cent 

Ist  experiment,  212  lbs.  of  roasted  coco,  milled  twice  with  the  husks, 
produced  of  chocolate  --.-__     209  lbs 

2d  experiment,  191  lbs.  ditto,  milled  twice  without  husks       -  -     189 

8H2 


t 


420 


CHROMATES. 


'i 


3d  experiment,  191  lbs.  kernels,  milled  once  along  with  19  lbs.  of  sugar 
=210  lbs.       ------■"    "'" 

4th  experiment,  573  lbs.  of  kernels,  milled  twice  along  with  68  lbs.  of 

flour  and  34  of  sugar  =  675  :   ,         '  "        ,     '         ^i  '       ?*  r. 

Sample  cakes  of  these  four  varieties  of  chocolate  were  subsefjuently  sent  to  me  fof 
examination  and  report  I  found  that  the  chocolate  milled  twice  with  the  flour  and 
ms&T  formed  a  complete  emulsion  with  hot  water,  bland  and  rich,  like  the  best  milk, 
but  the  other  three  were  much  inferior  in  this  respect  Sugar  alone,  with  proper 
milling  would  serve  to  give  the  kernels  of  well  roasted  coco  a  perfect  emulsive  pr<^ 
perty  Instead  of  merely  miUing  with  rotary  stones,  I  would  prefer,  for  the  second 
or  finishing  operation,  a  levigating  mill,  in  which  rollers  would  be  rolled  either  back- 
wards  and  forwards,  or,  when  slightly  conical,  in  a  circular  direction,  over  a  plane 
metallic,  marble,  or  porphyry,  slab  as  is  now,  indeed,  very  generally  practised  by  the 
trade.  The  coco-beans  should  be  weU  selected,  without  musty  taint,  and  possessed 
of  a  fine  aroma,  like  the  best  of  that  imported  from  Trinidad.  There  is  a  great 
deal  of  very  coarse  coco  and  chocolate  on  sale  in  London  and  in  the  provincial  towns 

of  the  United  Kingdom.  . . 

Fig.  359.  is  an  end  view  of  one  of  the  chocolate  mills  with 
its   mitre-gearing.      I    consider    the    gritty   chocolate    hitherto 
359  made  at  Deptford  as  a  very  bad  substitute  for  the  chocolate 
which  was  made  from  coco  by  the  sailors  themselves  with  a 
pestle  and  mortar.  . 

In  1840  the  coco  cleared  for  consumption  in  the  United  Kmg- 

dom  was: — 


British  plantation     - 

Foreign 

Coco-nut  husks  and  shells 

Chocolate  and  coco  paste 


2,041,492  lbs. 
186 
753,580 
2,066 


Of  the  cocoa-nut  shells,  612,122  lbs.  were  consumed  in  Ireland! 
and  less  than  4000  lbs.  of  coco.  ^ 

Of  coco,  726,116  lbs.  were  consumed  in  her  Majesty  s  navy. 
How  scurvily  are  the  people  of  Ireland  treated  by  their  own 
grocers !     Upwards  of  600,000  lbs.  of  worthless  coco  husks  served 
out  to  them  along  with  only  4000  lbs.  of  coco-beans ! 

The  quantity  of  coco  imported  in  1850  amounted  to  4,478,252 
cwts.  and  in  1851  to  6,773,900  cwts. ;  the  entries  for  home  consumption  were  3,103, 
926  and  3,024,338  cwts. ;  the  re-exports  were  1,443,363  and  1,543,456  cwts. ;  and  the 
erossamountofduty  16,059/.  and  15,778/.  respectively.      .^^   ^^     ^    .        ^       ^ 
CHROMATES,   saline   compounds   of  chromic   acid  with  the   basis,     bee   I^hro- 

^^Messrs.  Swindell  and  Co.  obtained  a  patent  in  November,  1850,  for  obtaining  copper, 

silver,  and  chrome,  from  their  ores.  j-      ♦    ♦u- 

1st  To  obtain  copper  and  silver,  or  copper  only,  from  their  ores,  accordmg  to  this 
invention,  the  ores  are  first  roasted  to  drive  off  the  sulphur,  and  convert  the  metals  to 
the  state  of  oxides,  after  which  the  prepared  ores  are  placed  in  tanks^and  a  solution 
of  ammonia  or  its  salts,  of  a  strength  of  about  0-980,  pumped  on  in  sufficient  quantity 
to  saturate  them.  This  solution  is  removed  at  the  expiration  of  twelve  to  twenty-four 
hours,  and  will  be  found  saturated  with  the  raetalUc  oxides,  which  are  to  be  dissolved 
in  boiling  water  and  precipitated— the  silver  by  hydrochloric,  and  the  copper  by 
hvdrosulphuric  acids  or  otherwise.  .  ^      i  •  i   •       •     j 

2nd.  The  ore  from  which  zinc  is  obtained  is  the  native  sulphuret,  which  is  mixed 
with  about  its  own  weight  of  common  salt  (for  which  muriate  of  potash,  or  of  any  earth, 
may  be  substituted),  and  exposed  in  a  calcining  furnace  to  a  slow  protracted  heat, 
until  all  the  sulphur  present  is  converted  into  sulphuric  acid.  The  products  ot  this 
operation  will  be  sulphate  of  soda,  muriate  of  zinc,  and  muriate  of  iron,  which  are  to 
be  dissolved  out  in  boiling  water,  and  the  two  latter  precipitated  by  bme^  or  other 
means,  after  the  sulphate  of  soda  has  been  separated  in  the  usual  manner.  The  oxide 
of  zinc  when  thus  precipitated,  may  be  smelted  in  the  usual  way.  ,      .•    ,      .., 

In  treating  chromium  (chromite  of  iron),  the  ore  is  pulverized  and  mixed  with 
common  salt,  muriate  of  potash,  or  hydrate  of  lime,  and  exposed  in  a  reverberatory 
furnace  to  a  red  or  even  a  white  heat  the  mixture  being  stirred  every  ten  or  fifteen 
minutes,  and  steam  at  a  very  elevated  temperature  introduced  during  the  operation, 
natil  the  desired  effett  is  obtained,  which  may  be  ascertained  by  withdrawmg  a  portion 

•  Thi«  small  excess  proceeded  from  a  residue  of  the  last  experiment. 


CHROMIUM, 


421 


from  the  flimace  and  testing  it,  as  customary.    The  products  of  this  operation  are 
finally  treated  in  the  manner  usual  for  chromic  and  bichromic  salts. 

The  mixture  of  chromium  and  common  salt  produces  chromate  of  soda,  the  greater 
portion,  or  perhaps  all  of  the  iron  contained  in  the  chromium  being  absorbed  by  the 
hydrochloric  acid  evolved  from  the  salt  and  carried  off  in  the  form  of  sesquichlonde  of 
iron.  From  the  first  mixture  is  manufactured  pure  bichromate  of  soda,  which,  by  the 
addition  of  hydrochloric  acid,  may  be  converted  to  chlorochromate  ;  and  from  the  last, 
or  lime  mixture,  is  produced  a  chromate  of  that  earth,  fiom  which,  by  the  addition  of 
soda  or  potash,  there  may  be  obtained  a  compound  salt,  which,  with  those  previously 
mentioned,  may  be  advantageously  employed  in  the  operation  specified  in  the  title. 

CHROMIC  ACID.  To  a  boiling  saturated  solution  of  bichromate  of  potash,  add  as 
much  oil  of  vitrol  as  will  convert  the  potash  into  a  bisulphate.  Let  the  whole  cool, 
and  be  then  washed  with  a  little  water,  and  stirred,  when  the  liquid  decanted  from  the 
granular  mass  will  be  nearly  pure  chromic  acid. 

The  solution  of  chromic  acid  in  oil  of  vitriol  is  preferable  as  an  oxidizing  agent  to 
every  other  at  present  known.     See  Chromium. 

CHROMIUM.  The  only  ore  of  this  metal,  which  occurs  in  sufl5cient  abundance 
for  the  purposes  of  art,  is  the  oclohedral  chrome-ore,  commonly  called  chromate  of  iron, 
though  it  is  rather  a  compound  of  the  oxydes  of  chromium  and  iron.  The  fracture  of 
this  mineral  is  uneven  ;  its  lustre  imperfect  metallic ;  its  color  between  iron-black  and 
brownish-black,  and  its  streak  brown.  Its  specific  gravity,  in  the  purest  state,  rises 
to  4*5 ;  but  the  usual  chrome-ore  found  in  the  market  varies  from  3  to  4.  According 
to  Klaproth,  this  ore  consists  of  oxyde  of  chromium,  43 ;  protoxide  of  iron,  34*7 ; 
alumina,  20-3;  and  silica,  2;  but  Vauquelin's  analysis  of  another  specimen  gave  as 
above,  respectively,  55-5,  33,  6,  and  2.  It  is  infusible  before  the  blowpipe ;  but  it  acts 
upon  the  magnetic  needle,  after  having  been  exposed  to  the  reducing  smoky  flame.  It 
is  entirely  soluble  in  borax,  at  a  high  blowpipe  heat,  and  imparls  to  it  a  beautiful  green 
color. 

Chrome-ore  is  found  at  the  Bare  Hills,  near  Baltimore,  in  Maryland ;  in  the  Shetland 
Isles,  Unst  and  Fetlar;  the  department  of  Var,  in  France,  in  small  quantity  j  and  near 
Portsoy,  in  Banffshire ;  as  also  in  Silesia  and  Bohemia. 

The  chief  application  of  this  ore  is  to  the  production  of  chromate  of  potash,  from 
which  salt  the  various  other  preparations  of  this  metal  used  in  the  arts  are  obtained. 
The  ore,  freed,  as  well  as  possible,  from  its  gangue,  is  reduced  to  a  fine  powder,  by 
being  ground  in  a  mill  under  ponderous  edge-wheels,  and  sifted.  It  is  then  mixed 
with  one  third  or  one  half  its  weight  of  coarsely  bruised  nitre,  and  exposed  to  a 
powerful  heat,  for  several  hours,  on  a  reverberatory  hearth,  where  it  is  stirred  about 
occasionally.  In  the  large  manufactories  of  this  country,  the  ignition  of  the  above 
mixture  in  pots  is  laid  aside,  as  too  operose  and  expensive.  The  calcined  matter  is  raked 
out,  and  lixiviated  with  water.  The  bright  yellow  solution  is  then  evaporated  briskly, 
and  the  chromate  of  potash  falls  down  in  the  form  of  a  granular  sail,  which  is  lifted 
out  from  time  to  time  from  the  bottom  with  a  large  ladle,  perforated  with  small  holes, 
and  thrown  into  a  drain  ing-box.  This  saline  powder  may  be  formed  into  regular  crystals 
of  neutral  chromate  of  potash,  by  solution  in  water  and  slow  evaporation ;  or  it  may  be 
converted  into  a  more  beautiful  crystalline  body,  the  bichromate  of  potash,  by  treating 
its  concentrated  solution  with  nitric,  muriatic,  sulphuric,  or  acetic  acid,  or,  indeed,  any 
acid  exercising  a  stronger  affinity  for  the  second  atom  of  the  potash  than  the  chromic 
acid  does. 

Bichromate  of  potash,  by  evaporation  of  the  above  solution,  and  slow  cooling,  may  be 
obtained  in  the  form  of  square  tables,  with  bevelled  edges,  or  fiat  four-sided  prisms. 
They  are  permanent  in  the  air,  have  a  metallic  and  bitter  taste,  and  dissolve  in  about  one 
tenth  of  their  weight  of  water,  at  60®  F. ;  but  in  one  half  of  their  weight  of  boiling  water. 
They  consist  of  chromic  acid  13,  potash  6  ;  or,  in  100  parts,  68-4  -f  31'6.  This  salt  is 
much  employed  in  calico-printing  and  in  dyeing  ;  which  see. 

Chromate  of  lead,  the  chrome-yellow  of  the  painter,  is  a  rich  pigment  of  various 
shades,  from  deep  orange  to  the  palest  canary  yellow.  It  is  made  by  adding  a  limpid 
solution  of  the  neutral  chromate  (the  above  granular  salt)  to  a  solution,  equally  limpid, 
of  acetate  or  nitrate  of  lead.  A  precipitate  falls,  which  must  be  well  washed,  and  care- 
fully dried  out  of  the  reach  of  any  sulphureted  vapors.  A  lighter  shade  of  yellow  is 
obtained  by  mixing  some  solution  of  alum,  or  sulphuric  acid,  with  the  chromate,  before 
p<(uring  it  into  the  solution  of  lead ;  and  an  orange  tint  is  to  be  procured  by  the  addition 
of  subacetate  of  lead,  in  any  desired  proportion. 

For  the  production  of  chromate  of  potash  from  chrome  ore,  various  other  processes 
have  been  recommended.  The  following  formute,  which  have  been  verified  in  practice^ 
will  prove  useful  to  the  manufacturers  of  this  important  article: — 

I.  Two  parts  of  chrome  ore,  containing  about  50  per  cent,  of  protoxyde  of  chromhun: 
One  part  of  saltpetre. 


i 


'1 


r  I 

I 


423 


CHROMIUM. 


n.  Foui  parts  of  chrome  ore,  conUdning  34  per  cent,  of  protoxyde  of  chromium. 

Two  parts  of  potashes. 

One  part  of  saltpetre. 
in.  Four  parts  of  chrome  ore.        —        34  — 

Two  of  potashes. 

Four  tenths  of  a  part  of  peroxyde  of  manganese. 
rV.  Three  parts  of  chrome  ore. 

Four  parts  of  saltpetre. 

Somrmanuflcturere  have  contrived  to  effect  the  conversion  of  the  oxyde  into  an  acid, 
and  of  course  to  form  the  chromate  of  potash,  by  the  agency  of  potash  alone,  in  a  calcining 
furnace,  or  in  earthen  pots  fired  in  a  pottery  kiln.  ,    .     ,        .  i-«m»  »nr« 

After  lixiviating  the  calcined  mixtures  with  water,  if  the  solution  be  a  tolerably  pure 
chromate  of  potash,  its  value  may  be  inferred,  from  its  specific  gravity,  by  the  followmg 

table :  —  _ 

At  specific  gravity  1*28  it  contains  about  50  per  cent,  of  the  salt. 

1-21  33 

1-18  25 

M5  SO 

M2  16 

Ml  14 

MO  12 

In  making  the  red  bichromate  of  potash  from  these  solutions  of  the  yellow  salt,  nitne 
acid  was  at  first  chiefly  used ;  but  in  consequence  of  its  relatively  high  price,  sulphuric, 
muriatic,  or  acetic  acid  has  been  frequently  substituted  upon  the  great  scale. 

There  is  another  application  of  chrome  which  merits  some  notice  here;  that  of  itsgreca 
oxyde  to  dyeing  and  painting  on  porcelain.  This  oxyde  may  be  prepared  by  decomposing, 
with  heat,  the  chromate  of  mercury,  a  salt  made  by  adding  to  nitrate  of  pi>3loxyde  of  mer- 
cury, chromate  of  potash,  in  equivalent  proportions.  This  chromate  has  a  fi»«c» ""«*«' 
red  when  pure :  and,  at  a  dull  red  heat,  parts  with  a  portion  of  its  oxygen  and  its 
mercurial  oxyde.  From  M.  Dulong's  experiments  it  would  appear  that  the  purest 
chromate  of  mercury  is  not  the  best  adapted  for  preparing  the  oxyde  of  chrome  to  be 
used  in  porcelain  painting.  He  thinks  it  ought  to  contam  a  little  oxyde  of  manganese 
;rd  chr^ate  of  p'otash,^to  afford  a  green  color  of  a  fine  tint,  especially  for  pieces  that 
"e  to  receive  a  powerful  heat.  Pure  oxyde  of  chrome  preserves  its  color  well  enough 
in  a  muffle  furnace ;  but,  under  a  stronger  fire,  it  lakes  a  dead-leaf  color. 

The  creen  oxyde  of  chrome  has  come  so  extensively  into  use  as  an  enamel  color  tor 
porcelain,  that  a  fuUer  account  of  the  best  modes  of  manufacturing  it  must  prove  accept- 

able  to  many  of  my  readers.  ,  .  •    ii« 

That  oxyde,  in  combination  with  water,  called  the  hydrate,  may  be  economiically 
prepared  by  boiling  chromate  of  potash,  dissolved  in  water,  with  half  its  weight  of 
flowers  of  sulphur,  till  the  resulting  green  precipitate  ceases  to  increase,  which  imy  be 
easily  ascertained  by  filtering  a  little  of  the  mixture.  The  addition  of  some  potash 
accelerates  the  operation.  This  consists  i^n  combining  the  sulphur  with  the  oxyge^  of 
Ae  chromic  acid,  so  as  to  form  sulphuric  acid,  which  unites  with  the  potash  of  the 
chromate  into  sulphate  of  potash,  while  the  chrome  oxyde  becomes  a  M'f  «^^-  /^" 
extra  quantity  of  potash  facilitates  the  deoxydizement  of  the  chromic  acid  by  the  forma- 
"ron  of  hypoLlphfie  and  sulphuret  of  potash,  both  of  which  have  ^  string  ,^"^^»««; 
for  oxy-en:  For  this  purpose  the  clear  lixivium  of  the  chromate  of  potash  is  sufficiently 
pure,  [hough  it  should  hold  some  alumina  and  silica  in  solution,  as  it  ?enera^^y  do«» 
The  hydrate  may  be  freed  from  particles  of  sulphur  by  heating  dilute  sulphuric  acid 
upon  it,  which  dissolves  it;  after  which  it  may  be  precipitated,  in  the  stale  ol  a 
carbonate,  by  carbonate  of  potash,  not  added  in  excess.  .  i        v       • 

By  calcininr  a  mixture  of  bichromate  of  potash  and  sulphur  m  a  crucible,  ehroipic 
acid  is  also  decomposed,  and  a  hydrated  oxyde  may  be  obtained;  the  sulphur  being 
nartly  converted  into  sulphuret  of  potassium,  and  partly  into  sulphuric  acid  (at  the 
expense  of  the  chromic  acid),  which  combines  with  the  rest  of  the  potash  into  a 
sulphate.  By  careful  lixiviation,  these  two  new  compounds  may  be  washed  away,  ana 
the  chrome  green  may  be  freed  from  the  remaining  sulphur,  by  a  slight  heat. 

Liebi*'  and  Wohler  have  lately  contrived  a  process  for  producing  a  subchromate  « 
lead  of\  beautiful  vermilion  hue.  Into  saltpetre,  brought  to  fusion  in  a  crucible  at 
a  irentle  heat,  pure  chrome  yellow  is  to  be  thrown  by  small  portions  at  a  time.  A 
stron-  ebullit  on  takes  place  at  each  addition,  and  the  mass  becomes  black,  and  con- 
Ss  so  whUe  it  is  hot.  The  chrome  yellow  is  to  be  added  till  little  of  the  saltpetre 
remans  uXomposed,  care  being  taken  not  to  overheat  the  crucible,  lest  the  cotor 
Tf  the  mixture  shbuld  become  brown.  Having  allowed  it  to  settle  for  a  few  minutes, 
during  which  the  dense  basic  salt  falls  to  the  bottom,  the  fluid  part,  consistmg  ol 


CHROMIUM. 


423 


diromate  of  potash  and  saltpetre,  is  to  be  poured  off,  and  it  can  be  employed  again  it 
preparing  chrome  yellow.  The  mass  remaining  in  the  crucible  is  to  be  washed  with 
iraler,  and  the  chrome  red  being  separated  from  the  other  matters,  is  to  be  dried  after 
proper  edulcoration.  It  is  essential  for  the  beauty  of  the  color,  that  the  saline  solution 
should  not  stand  long  over  the  red  powder,  because  the  color  is  thus  apt  to  become  of  a 
dull  orange  hue.  The  fine  crystalline  powder  subsides  so  quickly  to  the  bottom  after 
every  ablution,  that  the  above  precaution  may  be  easily  observed. 

As  Chromic  jicid  will  probably  ere  long  become  an  object  of  interest  to  the  calico 
printer,  I  shall  describe  here  the  best  method  of  preparing  it.  To  100  parts  of  yellow 
chromate  of  potash,  add  136  of  nitrate  of  barytes,  each  in  solution.  A  precipitate  of  the 
yellow  chromate  of  barytes  falls,  which  being  washed  and  dried  would  amount  to  130 
parts.  But  while  still  moist  it  is  to  be  dissolved  in  water  by  the  intervention  of  a  little 
Bitnc  acid,  and  then  decomposed  by  the  addition  of  the  requisite  quantity  of  sulphuric 
Bcid,  whereby  the  barytes  is  separated,  and  the  chromic  acid  remains  associated  with  the 
nitric  acid,  from  which  it  can  be  freed  by  evaporation  to  dryness.  On  re-dissolving  the 
chromic  acid  residuum  in  water,  filtering  and  evaporating  to  a  proper  degree,  50  parts 
of  chromic  acid  may  be  obtained  in  crystals. 

This  acid  may  also  be  obtained  from  chromate  of  lime,  formed  by  mixing  chromate  of 
potash  and  muriate  of  lime;  washing  the  insoluble  chromate  of  lime  which  precipitates, 
and  decomposing  it  by  the  equivalent  quantity  of  oxalic  acid,  or  for  ordinary  purposes  even 
sulphuric  acid  may  be  employed. 

Chromic  acid  is  obtained  in  quadrangular  crystiis,  of  a  deep  red  color ;  it  has  a  very 
acrid  and  styptic  taste.  It  reddens  powerfully  litmus  paper.  It  is  deliquescent  in  the  air. 
When  heated  to  redness  it  emits  oxygen,  and  passes  into  the  deutoxyde.  When  a  little  o€ 
it  is  fused  along  with  vitreous  borax,  the  compound  assumes  an  emerald  green  color. 

As  chromic  acid  parts  with  its  last  dose  of  oxygen  very  easily,  it  is  capable  in  certain 
styles  of  calico  priming  of  becoming  a  valuable  substitute  for  chlorine,  where  this  more 
powerful  substance  would  not  from  peculiar  circumstances  be  admissible.  For  this  in- 
genious application,  the  arts  are  indebted  to  that  truly  scientific  manufacturer,  M.  Daniel 
Kcechlin,  of  Miilhouse.  He  discovered  that  whenever  chromate  of  potash  has  its  acid 
set  free  by  its  being  mixed  with  tartaric  or  oxalic  acid,  or  a  neutral  vegetable  substance, 
(starch  or  sugar  for  example,)  and  a  mineral  acid,  a  very  lively  action  is  produced,  with 
disengagement  of  heat,  and  of  several  gases.  The  result  of  this  decomposition  is  the  active 
reagent,  chromic  acid,  possessing  valuable  properties  to  the  printer.  Watery  solutions 
of  chromate  of  potash  and  tartaric  acid  being  mixed,  an  effervescence  is  produced  which 
has  the  power  of  destroying  vegetable  colors.  But  this  power  lasts  no  longer  than  the 
effervescence.  The  mineral  acids  react  upon  the  chromate  of  potash  only  when  vegetable 
eoloring  matter,  gum,  starch,  or  a  vegetable  acid  are  present,  to  determine  the  disengage- 
ment of  gas.  During  this  curious  change  carbonic  acid  is  evolved  ;  and  when  it  takes 
l^ace  in  a  retort,  there  is  condensed  in  the  receiver  a  colorless  liquid,  slightly  acid, 
exhaling  somewhat  of  the  smell  of  vinegar,  and  containing  a  little  empyreumalic  oil. 
This  liquid  heated  with  the  nitrates  of  mercury  or  silver  reduces  these  metals.  On 
these  principles  M.  Koechlin  discharged  indigo  blue  by  passing  the  doth  through  a  solution 
of  chromate  of  potash,  and  printing  nitric  acid  thickened  with  gum  upon  certain  spots.  It 
is  probable  that  the  employment  of  chromic  acid  would  supersede  the  necessity  of  having 
recourse  in  many  cases  to  the  more  corrosive  chlorine. 

The  following  directions  have  been  given  for  the  preparation  of  a  blue  oxyde  of  chrome. 
The  concentrated  alkaline  solution  of  chromate  of  potash  is  to  be  saturated  with  weak 
sulphuric  acid,  and  then  to  every  8  lbs.  is  to  be  added  1  lb.  of  common  salt,  and  half  a 
pound  of  concentrated  sulphuric  acid ;  the  liquid  will  now  acquire  a  green  color.  To  be 
certain  that  the  yellow  color  is  totally  destroyed,  a  small  quantity  of  the  liquor  is  to  have 
potash  added  to  it,  and  filtered ;  if  the  fluid  is  still  yellow,  a  fresh  portion  of  salt  and  of 
sulphuric  acid  is  to  be  added ;  the  fluid  is  then  to  be  evaporated  to  dryness,  redissolved, 
and  filtered  ;  the  oxyde  of  chrome  is  finally  to  be  precipitated  by  caustic  potash.  It  will 
be  of  a  greenish-blue  color,  and  being  washed,  must  be  collected  upon  a  filter. 

Chromate  of  Potash,  ddulteration  of,  to  detect.  The  chromate  of  potash  has  the 
power  of  combining  with  other  salts  up  to  a  certain  extent  without  any  very  sensible 
change  in  its  form  and  appearance ;  and  hence  it  has  been  sent  into  the  market  falsified 
by  very  considerable  quantities  of  sulphate  and  muriate  of  potash,  the  presence  of 
which  has  often  escaped  observation,  to  the  great  loss  of  the  dyers  who  use  it  so  ex- 
tensively. The  following  test  process  has  been  devised  by  M.  Zuber,  of  Miilhouse. 
Add  a  large  excess  of  tartaric  acid  to  the  chromate  in  question,  which  will  decompose 
it,  and  produce  in  a  few  minutes  a  deep  amethyst  color.  The  supernatant  liquor 
will,  if  the  chromate  be  pure,  afford  now  no  precipitate  with  the  nitrates  of  barytes  or 
silver ;  whence  the  absence  of  the  sulphates  and  muriates  may  be  inferred.  We  must, 
however,  use  dilute  solutions  of  the  chromate  and  acid,  lest  bitartrate  of  potash  be  pre- 
cipitated, wliich  will  take  place  if  less  than  60  parts  of  water  be  employed.     Nor  must 


i 


i 


1 


V 


11 


4^4 


CITRIC  ACID. 


we  test  the  liquid  till  the  decomposition  be  complete,  and  till  the  colour  verge  rather 
towards  the  green  than  the  yellow.  Eight  parts  of  tartaric  acid  should  be  added  to  one 
of  chromate  to  obtain  a  sure  and  rapid  result  If  nitrate  of  potash  (saltpetre)  is  the 
adulterating  ingredient,  it  may  be  detected  by  throwing  it  on  burning  coals,  when 
deflagration  will  ensue.  The  green  colour  is  a  certain  mark  of  the  transformation  of  the 
chromic  acid  partially  into  the  chrome  oxide ;  which  is  effected  equally  by  the  sulphur- 
ous acid  and  sulphuretted  hydrogen.  Here  tliis  metallic  acid  is  disoxygenated  by  the 
tartaric,  as  has  been  long  known.  The  tests  which  I  should  prefer  are  the  nitrates  of 
silver  and  baryta,  having  previously  added  so  much  nitric  acid  to  the  solution  of  the  sus- 
pected chromate,  as  to  prevent  the  precipitation  of  the  chromate  of  silver  or  baryta. 
The  smallest  adulteration  by  sulphates  or  muriates  will  thus  be  detected. 

Chromium,  Oxide  of. — Mix  intimately  45  parts  of  gunpowder  with  240  parts 
of  perfectly  dry  chromate  of  potash,  and  35  parts  of  hydrochlorate  of  ammonia  (sal  am- 
moniac), reduce  to  powder,  and  pass  through  a  fine  sieve ;  fill  a  conical  glass  or  other 
mould  with  this  powder,  gently  pressed,  and  invert  so  as  to  leave  the  powder  on  a 
porcelain  slab  of  any  kind.  When  set  on  fire  at  its  apex  with  a  lighted  match,  it  will 
burn  down  to  the  bottom  with  brilliant  coruscations.  The  black  residuum,  being 
elutriated  with  warm  water,  affords  a  fine  bright  green  oxide  of  chromium. 

Chromium,  green  oxide  of. — Ignite  bichromate  of  potash  with  a  quarter  of  its  weight 
of  flowers  of  sulphur,  by  projecting  the  mixture  into  a  red  hot  crucible  in  small 
successive  portions,  stirring  the  pasty  mass  till  the  excess  of  sulphur  is  burnt  off ;  pul- 
verize the  cooled  mass,  and  wash  with  water  till  it  affords  no  precipitate  with  chloride 
of  barium  or  acetate  of  lead.  The  powder  which  remains  on  being  gently  dried  is  of  a 
beautiful  green  color,  and  may  be  used  as  a  pigment,  or  to  prepare  pure  chromium. 

CINNA3AR;  the  native  red  sulphuret  of  mercury.  It  occurs  sometimes  crystallized 
in  rhomboids ;  has  a  specific  gravity  varying  from  6*7  to  8-2 ;  a  flat  conchoidal  fracture ; 
is  fine  grained;  opaque;  has  an  adamantine  lustre,  and  a  color  passing  from  cochineal  to 
ruby  red.  The  fibrous  and  earthy  cinnabar  has  a  scarlet  hue.  It  is  met  with  disseminat- 
ed in  smaller  or  larger  lumps  in  veins,  which  are  surrounded  by  a  black  clay,  and  is  asso- 
ciated with  native  quicksilver,  amalgam,  with  iron-ore,  lead-glance,  blende,  copper-ore, 
gold,  &c.  Its  principal  localities  are  Almaden  in  Spain,  Idria  in  the  Schiefergebirge, 
Kreranitz  and  Schemnitz  in  Hungary;  in  Saxony,  Bavaria,  Bohemia,  Nassau,  China,  Ja- 
pan, Mexico,  Columbia,  Peru.  It  consists  of  two  primes  of  sulphur,  =  32-240,  com- 
bined with  one  of  mercury,  =  202,863  ;  or  in  100  parts  of  12-7  sulphur  -\-  87-3  mercury. 
It  is  the  most  prolific  ore  of  this  meial ;  and  is  easily  smelted  by  exposing  a  mixture  of  it 
with  iron  or  lime  to  a  red  heat  in  retorts.  Factitious  cinnabar  is  called  in  commerce 
Vermilion,  which  see,  as  also  Mercury. 

CINNAMON.  (Cannellej  Ft.  ;  Zimmt,  Germ.)  Is  the  inner  bark  of  the  laums  cinna- 
momum,  a  handsome-looking  tree  which  grows  naturally  to  the  height  of  18  or  20  feet,  in 
Java,  Sumatra,  Ceylon,  and  other  islands  in  the  East  Indian  seas.  It  has  been  transplant- 
ed to  the  Antilles,  particularly  Guadaloupe  and  Martinique,  as  well  as  Cayenne,  but  there 
it  produces  a  bark  of  very  inferior  value  to  the  Oriental. 

Cinnamon  is  gathered  twice  a  year,  but  not  till  after  the  tree  has  attained  to  a  certain 
age  and  maturity.  The  young  twigs  yield  a  bark  of  better  quality  than  the  larger  branch- 
es. The  first  and  chief  harvest  takes  place  from  April  to  August ;  the  second,  from  No- 
vember to  January.  After  having  selected  the  proper  trees,  all  the  branches  more  thaa 
three  years  old  are  cut  off";  the  epidermis  is  first  removed  with  a  two-edged  pruning  knife, 
then  a  longitudinal  incision  is  made  through  the  whole  extent  of  the  bark,  and  lastly,  with 
the  bluntest  part  of  the  knife,  the  true  bark  is  carefully  stripped  off"  in  one  piece.  All 
these  pieces  of  bark  are  collected,  the  smaller  ones  are  laid  within  the  larger,  and  in  this 
state  they  are  exposed  to  the  sun,  whereby  in  the  progress  of  drying,  they  become  rolled 
into  the  shape  of  a  quill.  These  convoluted  pieces  are  formed  into  oblong  bundles  of 
20  or  30  lbs.  weight,  which  are  placed  in  warehouses,  sorted  and  covered  with  mats. 
Good  cinnamon  should  be  as  thin  as  paper,  have  its  peculiar  aromatic  taste,  without 
burning  the  tongue,  and  leave  a  sweetish  flavor  in  the  mouth  The  broken  bits  of 
cinnamon  are  used  in  Ceylon  for  procuring  the  essential  oil  by  distillation.  445,367  lbs. 
of  cinnamon  were  imported  into  this  kingdom  in  1835,  of  which  16,604  only  were  re- 
tained for  internal  consumption. 

CITRIC  ACID.  (Jcide  citriquCy  Fr. ;  Citrwiensaure,  Germ.)  Scheele  first  procured 
this  acid  in  its  pure  state  from  lemon  juice,  by  the  following  process.  The  juice  put  into  a 
large  tub,  is  to  be  saturated  with  dry  chalk  in  fine  powder,  noting  carefully  the  quantity 
employed.  The  citrate  of  lime  which  precipitates,  being  freed  from  the  supernatant  foul 
liquor,  is  to  be  well  washed  with  repeated  affusion  and  decantation  of  water.  For  every  10 
pounds  of  chalk  employed,  nine  and  a  half  pounds  of  sulphuric  acid,  diluted  with  six 
times  its  weight  of  water,  are  to  be  poured  while  warm  upon  the  citrate  of  lime,  and  well 
mixed  with  it.    At  the  end  of   twelve    hours,  or  even  sooner,  the  citrate  will  be  all 


CIVET. 


425 


decomposed,  dilute  citric  acid  will  float  above,  and  sulphate  of  lime  will  be  found  at 
the  bottom.  The  acid  being  drawn  off,  the  calcareous  sulphate  must  be  thrown  on  a 
canvass  filter,  drained,  and  then  washed  with  water  to  abstract  the  whole  acid. 

The  citric  acid  thus  obtained  may  be  evaporated  in  leaden  pans,  over  a  naked  fire  till 
it  acquires  the  specific  gravity  1-13  ;  after  which  it  must  be  transferred  into  another  vea- 
sel,  evaporated  by  a  steam  or  water  bath  till  it  assumes  a  syrupy  aspect,  when  a  pellicle 
appears  first  in  patches,  and  then  over  the  whole  surface.  This  point  must  be  watched 
with  great  circumspection,  for  if  it  be  passed,  the  whole  acid  runs  a  risk.of  being  spoiled 
by  carbonization.  The  steam  or  hot  water  must  be  instantly  withdrawn,  and  the  con 
centrated  acid  put  into  a  crystallizing  vessel  in  a  dry,  but  not  very  cold  apartment  At 
the  end  of  four  days  the  crystallization  will  be  complete.  The  crystals  must  be  drained, 
re-dissolved  in  a  small  portion  of  water,  the  solution  set  aside  to  settle  its  impurities^ 
then  decanted,  re-evaporated,  and  re-crystallized.  A  third  or  fourth  crystallization  may 
be  necessary  to  obtain  a  colourless  acid. 

If  any  citrate  of  lime  be  left  undecomposed  by  the  sulphuric  acid,  it  will  dissolve  in 
the  citric  acid,  and  obstruct  its  crystallization,  and  hence  it  will  be  safer  to  use  the 
slightest  excess  of  sulphuric  acid,  than  to  leave  any  citrate  undecomposed.  There  should  " 
not,  however,  be  any  great  excess  of  sulphuric  acid.  If  there  be,  it  is  easily  detected  by 
nitrate  of  barytes,  but  not  by  the  acetate  of  lead  as  prescribed  by  some  chemical  authors; 
because  the  citrate  of  lead  is  not  very  soluble  in  the  nitric  acid,  and  might  thus  be  con- 
founded with  the  sulphate,  whereas  citrate  of  barytes  is  perfectly  soluble  in  that  test 
acid.  Sometimes  a  little  nitric  acid  is  added  with  advantage  to  the  solution  of  the 
coloured  crystals,  with  the  effect  of  whitening  them. 

Twenty  gallons  of  good  lemon  juice  will  afford  fully  ten  pounds  of  white  crystals  of 
citric  acid. 

Attempts  were  made  both  in  the  "West  Indies  and  Sicily,  to  convert  the  lime  and 
lemon  juice  into  citrate  of  lime,  but  they  seem  to  have  failed  through  the  diflSculty  of 
drying  the  citrate  for  shipment. 

The  cr^'stals  of  citric  acid  are  oblique  prisms  with  four  faces,  terminated  by  dihedral 
summits,  inclined  at  acute  angles.  Their  specific  gravity  is  1'617.  They  are  unalter- 
able in  the  air.  When  heated,  they  melt  in  their  water  of  crj'stallization ;  and  at  a 
higher  heat,  they  are  decomposed.  They  contain  18  per  cent  of  water,  of  which  one- 
half  may  be  separated  in  a  dry  atmosphere,  at  about  100°  F.,  when  the  crystals  fall  into 
a  white  powder. 

Citric  acid  in  crystals  is  composed  by  my  analysis  of  carbon,  35 "8,  oxygen  59*7,  and 
hydrogen  45 ;  results  which  differ  very  little  from  those  of  Dr.  Front  subsequently 
obtained.  I  found  its  atomic  weight  to  be  8*375,  compared  to  oxygen  1,000.  I  cannot 
account  for  Berzelius's  statements  relative  to  the  composition  of  this  acid. 

Citric  acid  in  somewhat  crude  crjstals  is  emplo3'ed  with  much  advantage  in  calico- 
printing.  If  adulterated  with  tartaric  acid,  the  fraud  may  be  detected  by  adding  potash 
to  the  solution  of  the  acid,  which  will  cause  a  precipitate  of  cream  of  tartar. 

The  manufacture  of  citric  acid  so  closely  resembles  that  of  tartaric  acid,  that  the  makers 
of  one  commonly  fabricate  the  other.  The  raw  material  in  this  case  is  pretty  generally 
a  black  fluid,  like  thin  treacle,  which  comes  from  Sicily,  and  is  obtained  by  inspissating 
the  expressed  juice  of  the  lemon, — the  rind  having  previously  been  removed  from  the 
lemon  for  the  sake  of  its  essential  oil.  This  black  juice  is  impure  citric  acid,  and  re- 
quires to  be  treated  with  chalk,  as  practised  with  respect  to  the  first  operation  on 
tartar ;  by  which  means,  an  insoluble  citrate  of  lime  is  formed ;  and  this,  after  being 
well  washed  with  cold  water,  is  decomposed  by  sulphuric  acid ;  and  the  solution,  after 
undergoing  the  action  of  animal  charcoal  and  proper  evaporation,  yields  brownish  crystals 
on  cooling.  These  are  re-dissolved,  discoloured,  and  crystallized  three  or  four  times  ere 
they  can  be  sent  into  the  market  for  citric  acid  is  more  tenacious  of  colouring  matter  than 
most  of  the  other  vegetable  acids.  At  Nice,  and  in  the  South  of  France,  a  portion  of 
chloride  of  lime  is  digested  upon  the  citrate  of  lime,  to  bleach  it  prior  to  decomposition 
by  sulphuric  acid.  For  this  purpose,  the  washed  citrate  is  exposed  in  shallow  vessels 
to  the  action  of  the  sun's  rays,  covered  by  a  weak  solution  of  chloride  of  lime.  In  a  few 
hours  decolouration  ensues  ;  and  it  is  moreover  stated  that  the  mucilage  which  hangs 
about  the  citrate  of  lime,  and  impedes  the  subsequent  crystallization  of  the  acid,  is  in  this 
way  destroyed,  and  the  number  of  re-crystaUizations  requisite  to  give  a  saleable  aspect 
to  the  citric  acid  thereby  diminished.  The  use  of  chloride  of  lime  for  this  purpose 
seems  unknown,  or,  at  least,  is  not  practised  in  England.  Of  the  samples  of  citric  acid 
shown  in  the  Great  Exhibition,  those  from  Howards  and  Kent  of  Stratford,  Fontifex 
and  Wood,  of  Millwall,  and  J.  Huskisson,  of  Gray's  Inn  Road,  were  extremely  beautiful ; 
and  in  respect  to  size  and  crystalline  form  surpassed  anything  exhibited  in  the  French, 
Prussian,  or  Italian  departments. 

CIVET.  {Civette,  Fr. ;  Zibeth,  Germ.)  This  substance  approaches  in  smell  to 
musk  and  ambergris ;  it  has  a  pale  yellow  colour,  a  somewhat  acrid  taste,  a  consistence 

Vou  L  3  1 


i 


III 


i!  • 


>  -' 


1  -■  [ 

V.,. 

r '' 


426 


CLAY. 


like  that  of  honey,  and  a  very  strong  aromatic  odour.  It  is  the  product  of  two  small 
quadrupeds  of  the  genus  viverra  {v.  zibetha  and  v.  civetta),  of  which  the  one  inhabits 
Africa,  and  the  other  Asia.  They  are  reared  with  tenderness,  especially  in  Abyssinia. 
The  civet  is  contained  in  a  sac,  situated  between  the  anus  and  the  parts  of  generation, 
in  either  sex.  The  animal  frees  itself  from  an  excess  of  this  secretion  by  a  contractile 
movement  which  it  exercises  upon  the  sac,  when  the  civet  issues  in  a  vermicular 
form  and  is  carefully  collected.  The  negroes  are  accustomed  to  increase  the  secretion 
by  irritating  the  animal ;  and  likewise  introduce  a  little  butter,  or  other  grease,  by  the 
natural  slit  in  the  bag,  which  mixes  with  the  odoriferous  substance,  and  increases  its 
weight     It  is  employed  only  in  perfumery. 

According  to  M.  Boutron-Chalard,  it  contains  a  volatile  oil,  to  which  it  owes  ita 
smell,  some  free  ammonia,  resin,  fat,  an  extractiform  matter,  and  mucus.  It  affords  by 
calcination  an  ash,  in  which  there  are  some  carbonate  and  sulphate  of  potash,  phosphate 
of  lime,  and  oxide  of  iron. 

CLAY  {Argile,  Fr. ;  Thon,  Germ.)  is  a  mixture  of  the  two  simple  earths,  alumina 
and  silica,  generally  tinged  with  iron.  Lime,  magnesia,  with  some  other  colouring  me- 
tallic oxides,  are  occasionally  present  in  small  quantities  in  certain  natural  clays. 

The  different  varieties  of  clay  possess  the  following  common  characters : — 

1.  They  are  readily  diflFusible  through  water,  and  are  capable  of  forming  with  it  a 
plastic  ductile  mass,  which  may  be  kneaded  by  hand  into  any  shape.  This  plasticity 
exists,  however,  in  very  different  degrees  in  the  different  clays. 

2.  They  concrete  into  a  hard  mass  upon  being  dried,  and  assume,  upon  exposure  to 
the  heat  of  ignition,  a  degree  of  hardness  sometimes  so  great  as  to  give  sparks  by  col- 
lision with  hardened  steel.  In  this  state  they  are  no  longer  plastic  with  water,  even 
when  pulverised.  Tolerably  pure  clays,  though  infusible  in  the  furnace,  become  readily 
so  by  the  admixture  of  lime,  iron,  manganese,  <fee. 

3-  All  clays,  even  when  previously  freed  from  moisture,  shrink  in  the  fire  in  virtue 
of  the  reciprocal  affinity  of  their  particles ;  they  are  very  absorbent  of  water  in  their 
dry  slate,  and  adhere  strongly  to  the  tongue. 

4.  Ochrey,  impure  clays  emit  a  disagreeable  earthy  smell  when  breathed  upon. 

Brongniart  distributes  the  clay  into : — 

1.  Fire-clays,  {argiles  apyres,  Fr. ;  feuerfeste,  Germ.) 

2.  Fusible,  {sehmdzbare,  Germ.) 

3.  Effervescing  {brausende,  Germ.)  from  the  presence  of  chalk. 

4.  Ochrey  {ocreuses,  Fr. ;  ockrige,  Germ.) 

Fire-clay  is  found  in  the  greatest  abundance  and  perfection  for  manufacturing  pur^ 
poses  in, 

I.  Slate-clay.  {Thon-schiefer,  Germ.)  Its  colour  is  gray  or  grayish  yellow.  Massive^ 
dull,  or  glimmering  from  admixture  of  particles  of  mica.  Fracture  slaty,  approaching 
sometimes  to  earthy.  Fragments  tabular.  Soft^  sectile,  and  easily  broken.  Sp.  gr.=  2 '6. 
Adheres  to  the  tongue,  and  breaks  down  in  water.  It  occurs  along  with  pit  co€U  ;  which 
see.  Slate-clay  is  ground,  and  reduced  into  a  paste  with  water,  for  making  fire-bricks ; 
for  wnich  purpose  it  should  be  as  free  as  possible  from  lime  and  iron. 

2-  Common  clay  or  loam. — ^This  is  an  impure  coai*se  pottery  clay,  mixed  with  iron 
ochre,  and  occasionally  with  mica.  It  has  many  of  the  external  characters  of  plastic 
clay.  It  is  soft  to  the  touch,  and  forms,  with  water,  a  somewhat  tenacious  paste; 
but  is  in  general  less  compact,  more  friable,  than  the  plastic  clays,  which  are  more 
readily  ditfusible  in  water.  It  does  not  possess  the  property  of  acquiring  in  water 
that  commencement  of  translucency  which  the  purer  clays  exhibit  Although  soft 
to  the  touch,  the  common  clay  wants  unctuosity^,  properly  so  called.  The  best  ex- 
ample of  this  argillaceous  substance  is  aflForded  in  the  London  clay  formation,  which 
consists  chiefly  of  bluish  or  blackish  clay,  mostly  very  tough-  Those  of  its  strata  which 
effervesce  with  acids  partake  of  the  nature  of  marl.  This  clay  is  fusible  at  a  strong  heat 
in  consequence  of  the  iron  and  lime  which  it  contains.  It  is  employed  in  the  manu- 
facture of  bricks,  tiles,  and  coarse  pottery  ware. 

3.  Potter's  clay,  or  Plastic  clay. — ^This  species  is  compact,  soft,  or  even  unctuous  to 
the  touch,  and  polishes  with  the  pressure  of  the  finger;  it  forms,  with  water,  a  tenacious, 
very  ductile,  and  somewhat  translucent  paste.  It  is  infusible  in  a  porcelain  kiln, 
but  assumes  in  it  a  great  degree  of  hardness.  Werner  calls  it  pipe-clay.  Good  plastic 
clay  remains  white,  or  if  gray  before,  becomes  white  in  the  porcelain  kiln. 

The  geological  position  of  the  plastic  clay  is  beneath  the  London  clay,  and  above  the 
sand  which  covers  the  chalk  formation.  The  plastic  clay  of  the  Paris  basin  is  described  as 
consisting  of  two  beds  separated  by  a  bed  of  sand.  The  lower  bed  is  the  proper  plastic 
clay.  The  plastic  clay  of  Abondant,  near  the  forest  of  Dreux,  analyzed  by  Yauquelin, 
gave — 

Silica,  43*5;   alumina,  33*2;  lime,  0*35;  iron,  1;  water,  18. 


CLAY. 


421 


This  clay  is  employed  as  a  fire  clay  for  making  the  bungs  or  seggars,  or  coarse  earthen- 
ware cases,  in  which  china  ware  is  tired. 

The  plastic  clay  of  Dorsetshire  and  Devonshire  supplies  the  great  Staffordshire  pot- 
teries. It  is  gray-coloured,  less  unctuous  than  that  of  Dreux,  and  consequently  more 
friable.  It  becomes  white  in  the  pottery  kiln,  and  is  infusible  at  that  heat  It  causes 
no  effervescence  with  nitric  acid,  but  falls  down  quickly  in  it,  and  becomes  higher 
coloured.  Its  refractoriness  allows  of  a  harder  glaze  being  applied  to  the  ware  formed 
from  it  without  risk  of  the  heat  requisite  for  making  the  glaze  flow  affecting  the  biscuit 
either  in  shape  or  colour.  "  Most  of  the  plastic  clays  of  France,"  says  M.  Brongniart^ 
"  employed  for  the  same  ware,  have  the  disadvantage  of  reddening  a  little  in  a  somewhat 
strong  heat ;  and  hence  it  becomes  necessary  to  coat  them  with  a  soft  glaze,  fusible  by 
means  of  excess  of  lead  at  a  low  heat,  in  order  to  preserve  the  white  appearance  of  the 
biscuit  Such  a  glaze  has  a  dull  aspect,  and  cracks  readily  into  innumerable  fissures  by 
alternations  of  hot  and  cold  water."  Hence  one  reason  of  the  vast  inferiority  of  the 
French  stone-ware  to  the  English. 

4.  Porcelain  clay  or  Kaolin  earth. — ^The  Kaolins  possess  very  characteristic  proper- 
ties. They  are  friable  in  the  hand,  meagre  to  the  touch,  and  difficultly  form  a  paste 
with  water.  When  freed  from  the  coarse  and  evidently  foreign  particles  interspei-sed 
through  them,  they  are  absolutely  infusible  in  the  porcelain  kiln,  and  retain  their  white 
colour  unaltered.  They  harden  with  heat  like  other  clays,  and  perhaps  in  a  greater 
degree  ;  but  they  do  not  acquire  an  equal  condensation  or  solidity,  at  least  when  they 
are  perfectly  pure.  The  Kaolins  in  general  appear  to  consist  of  alumina  and  silica  in 
neany  equal  proportions.  Most  of  the  Kaolin  clays  contain  some  spangles  of  mica 
which  betray  their  origin  from  disintegrated  granite. 

This  origin  may  be  regarded  as  one  of  their  most  distinctive  features.  Almost  all 
the  porcelain  clays  are  evidently  derived  from  the  decomposition  of  the  felspars,  granites, 
and  principally  those  rocks  of  felspar  and  quartz,  called  graphic  granite.  Hence  they 
are  to  be  found  only  in  primitive  mountain  districts,  among  banks  or  blocks  of  granite, 
forming  thin  seams  or  partings  between  them.  In  the  same  partings,  quartz  and  mica 
occur,  being  relics  of  the  granite  ;  while  some  seams  of  Kaolin  retain  the  external  forna 
of  felspar. 

The  most  valuable  Kaolins  have  been  found : — 

In  China  and  Japan.  The  specimens  imported  from  these  countries  appear  pretty 
white ;  but  are  more  unctuous  to  the  touch,  and  more  micaceous  than  the  porcelain 
days  of  France. 

In  Saxony.  The  Kaolin  employed  in  the  porcelain  manufactories  of  that  country 
has  a  slight  yellow  or  flesh  colour,  which  disappears  in  the  kiln,  proving,  as  Walleriui 
observed,  that  this  tint  is  not  owing  to  any  metallic  matter. 

In  France,  at  Saint-Yriex-la-Perche,  about  10  leagues  from  Limoges.  Tlie  Kaolin 
occurs  there  in  a  bed,  or  perhaps  a  vein  of  beds  of  granite,  or  rather  of  that  felspar  rock 
called  Pe-tun-tse,  which  exists  here  in  every  stage  of  decomposition.  This  Kaolin  is 
generally  white,  but  sometimes  a  little  yellowish,  with  hardly  any  mica.  It  is^eagre 
to  the  touch,  and  some  beds  include  large  grains  of  quartz,  called  pebbly  by  the  Chiiia 
manufacturers.  This  variety,  when  ground,  affords,  without  the  addition  of  any  fusible 
ingredient,  a  very  transparent  porcelain. 

Near  Bayonne.  A  Kaolin  possessing  the  lamellated  structure  of  felspar,  in  many 
places.     The  rock  containing  it  is  a  graphic  granite  in  every  stage  of  decomposition. 

In  England  in  the  county  of  Cornwall  This  Kaolin  or  China  clay  is  very  white, 
and  more  unctuous  to  the  touch  than  those  upon  the  continent  of  Europe  mentioned 
above.  Like  them  it  results  from  the  decomposition  of  the  felspars  and  granites,  occur- 
ring in  the  middle  of  these  rocks.  Mr.  Wedgewood  found  it  to  contain  60  of  alumina 
or  pure  clay,  and  40  of  silica,  in  100  parts. 

Pure  clay,  the  alumina  of  the  chemist,  is  absolutely  infusible ;  but  when  subjected  to 
the  fire  of  a  porcelain  kiln,  it  contracts  into  about  one-half  of  its  total  bulk.  It  must, 
however,  be  heated  very  cautiously,  otherwise  it  will  decrepitate  and  fly  in  pieces,  owing 
to  the  sudden  expansion  into  steam  of  the  water  combined  with  its  particles,  which  is 
retained  with  a  considerable  attractive  force.  It  possesses  little  plasticity,  and  con- 
sequently affords  a  very  short  paste,  which  is  apt  to  crack  when  kneaded  into  a 
cake. 

It  is  not  only  infusible  by  itself^  but  it  will  not  dissolve  in  the  fusible  glasses; 
making  them  merely  opaque.  If  either  lime  or  silica  be  added  separately  to  pure  clay, 
in  any  proportion,  the  mixture  will  not  melt  in  the  most  violent  furnace ;  but  if  alumina, 
lime,  and  silica  be  mixed  together,  the  whole  melts,  and  the  more  readily,  the  nearer  the 
mixture  approaches  to  the  following  proportions : — 1  of  alumina,  1  of  lime,  and  8  of 
sand.  If  the  sand  be  increased  to  five  parts,  the  compound  becomes  infusible.  These 
interesting  facts  show  the  reciprocal  action  of  those  earths  which  are  mixed  most  com- 
monly in  nature  with  alumina. 

812 


i 


t.T 


i: 


428 


CLAY. 


Iron  in  small  quantity,  but  in  a  state  not  precisel}^  determined,  though  probably  of 
protoxide,  does  not  colour  the  clays  till  they  are  subjected  to  a  powerful  heat.  There 
are  very  white  clays,  such  as  those  of  Montereau,  which  do  not  become  red  till  calcined 
in  the  porcelain  kiln ;  the  oxide  of  iron  contained  in  them,  which  coloui-s  them  in  that 
case,  was  previously  imperceptible.  It  appears  from  this  circumstance,  that  the  clays 
fit  for  making  fine  white  stone  ware,  as  also  the  Kaolins  adapted  to  the  manufacture  of 

porcelain,  are  very  rare. 

Iron  in  larger  proportion,  usually  colours  the  claj's  green  or  slate-blue,  before  they 
have  been  heated.  Such  clays,  exposed  to  the  action  of  fire,  become  yellow  or  red  ac- 
cording to  the  quantity  of  iron  which  they  contain.  When  the  iron  is  very  abundant, 
it  renders  the  clays  fusible ;  but  a  little  lime  and  silica  must  also  be  present  for  this 
effect  The  earthenware  made  with  these  ferruginous  clays  can  bear  but  a  moderate 
baking  heat ;  it  is  thick,  porous,  and  possesses  the  advantage  merely  of  cheapness,  and 
of  bearing  considerable  alternations  of  temperature  without  breaking. 

Alumina  and  the  very  aluminous  natural  clays  which  possess  most  plasticity  are  apt 
to  crack  in  drying,  or  to  lose  their  shape.  This  very  serious  defect  for  the  purposes  of 
pottery  is  rectified,  in  some  measure,  by  adding  to  that  earth  a  certain  quantity  of  sand 
or  silica.  Thus,  a  compound  is  formed  which  possesses  less  attraction  for  water  and 
dries  more  equably  from  the  openness  of  its  body.  The  principal  causes  of  the  distortion 
of  earthenware  vessels,  are  the  unequal  thickness  of  their  parts,  and  quicker  desiccation 
upon  one  side  than  another.  Hard  burnt  stone-ware  ground  to  powder,  and  incoroo- 
rated  with  clay,  answers  still  better  than  sand  for  counteracting  the  great  and  irregular 
contraction  which  natural  pottery  paste  is  apt  to  experience.  Such  ground  biscuit  is 
called  cement ;  and  its  grains  interspersed  through  the  ware,  may  be  regarded  as  bo 
many  solutions  of  continuity,  which  arrest  the  fissures. 

The  preceding  observations  point  out  the  principles  of  those  arts  which  employ  clay 
for  moulding  by  the  wheel,  and  baking  in  a  kiln.     See  Porcelain  and  PorrERY. 

The  chemical  composition  of  the  clays  shown  at  the  Great  Exhibition  was  unfoi^ 
innately  not  given,  as  it  ought  to  have  been.  The  injurious  effect  of  this  ignorance  will, 
by-and-by,  come  under  consideration,  when  speaking  of  the  art  of  the  potter ;  but,  for 
the  present,  we  shall  content  ourselves  with  a  liasty  glance  at  the  various  specimens  of 
'  clay  exhibited  in  Class  I.,— adding,  as  usual,  a  few  practical  hints  for  the  analysis  of 
these  substances,  together  with  some  analytical  investigations  recently  made  upon 
average  market  samples  of  clay,  for  the  express  purpose  of  elucidatmg  this  obscure 
subject.  In  a  manufacturing  point  of  view,  clays  may  be  conveniently  divided  into  three 
classes;  for  although  a  fourth  (that  is  to  say,  common  marl  clay)  exists,  yet,  as  its  em- 
ployment is  limited  to  the  making  of  bricks  and  other  coarse  articles  in  which  improve- 
ment is  nearly  hopeless,  so  far  as  regards  material,  we  shall  confine  our  observations  to 
the  three  finer  qualities,  named,  respectively,  china  clay  or  kaolin,  fire-clay,  and  potter's 
clay.  In  china  clav,  Jenkins  &  Courtney,  of  Truro ;  Whitley  of  Truro  ;  C.  Thriscutt,  of 
St  Austell ;  the  West  of  England  China  Stone  and  Clay  Company ;  Truscott,  Martyn, 
Brown,*  Michell,  and  Wheeler,  Philip  <fe  Co.,  all  of  St.  Austell ;  and  W.  Phillips,  of 
the  Morley  Works,  near  Plympton,  together  with  Sir  G.  Hodson,  Bart.,  of  Wicklow  in 
Ireland,  exhibit  some  samples  of  great  beauty  and  apparent  purity.  In  fire-clay,  the 
articles  shown  by  King  <fe  Co.,  Squires  &  Son,  and  F.  T.  Rafford,  of  Stourbridge,  with 
those  from  Cowan  <fe  Co.,  Ramsey  <fe  Co.,  and  Potter,  of  Newcastle,  are  excellent ;  and 
a  sample  from  Pease  of  Darlington,  also  deserves  notice.  In  potter's  clay,  Whiteway, 
Watts,  <fe  Co.,  of  Dorset;  Fayle  <fe  Co.,  of  Thames  Street^  London;  W.  <fe  J.  Peike, 
of  the  Isle  of  Purbeck;  N.  Burnet,  of  Gateshead;  and  the  North  Devon  Pottery 
Company,  are  the  most  remarkable,  though  there  are  many  very  respectable  lookmg 
samples  from  other  quarters. 

In  the  manufacture  of  earthenware  goods,  it  is  indispensably  necessary  to  mix  the  clay, 
in  the  first  instance,  with  some  infusible  material,  which  does  not  contract  or  diminish 
under  the  influence  of  heat ;  for  all  kinds  of  clay  shrink  very  much  by  the  action  of  a 
high  and  prolonged  temperature,  and  are  therefore  liable,  during  such  exposure,  to  warp 
and  twist  out  of  shape,  or  become  cracked  in  the  furnace.  Hence  a  remedy  is  sought 
as  above  indicated,  and  for  this  purpose,  silica,  in  a  minute  state  of  division,  is  generally 
preferred  ;  though  felspar,  and  a  kind  of  decomposing  granite,  called  Cornish  stone,  are 
also  used.  But  whatever  may  be  the  material,  its  introduction  into  the  body  of  the 
earthenware  is  conducted  on  purely  empirical  principles,  for,  as  the  composition  of  the 
clay  is  unknown,  no  attempt  can  be  or  is  made  to  effect  a  combination  in  unison  with 
the  laws  of  chemical  affinity.  The  substances  employed  are  recognised  only  as  clay,  and 
perhaps  ground  flint ;  nor  is  any  other  test  used  to  ascertain  the  proper  proportion  of 
each  towards  the  other,  than  the  uncertain  judgment  of  a  workman,  or  the  equally 
fallacious  practice  of  an  established  rule.  As,  however,  all  clays,  in  a  state  of  natural 
purity,  consist  of  silica  and  alumina,  united  together  in  definite  atomic  proportion^ 
there  can  be  no  doubt  that  perfection  in  earthenware  depends  upon  this  simple  law ;  and 


CLAY. 


429 


that  the  only  true  mode  of  fabricating  a  uniform  and  really  valuable  kind  of  pottery- 
vare,  would  be  to  follow  out  the  indications  of  nature,  and  constantly  preserve  an  atomic 
ratio  in  the  admixture  of  the  flint  and  clay  of  which  that  pottery-ware  is  composed. 
Of  course,  under  existing  circumstances,  this  is  impossible ;  for,  as  we  have  previously 
remarked,  the  precise  composition  of  the  different  clays  used  in  the  arts  is  totally  un- 
kno\^ui ;  and,  independent  of  any  chemical  difficulties  that  may  be  presumed  to  exist  in 
determining  this  important  fact  for  themselves,  our  manufacturers  may  justly  plead  that 
no  simple  and  satisfactory  mode  of  analyzing  clay  has  yet  been  published.  Hence  the 
present  empirical  system  is  universal ;  and  the  accidental  admixtures  it  produces  testify 
to  the  truth  of  our  remarks,  by  cracking  and  flying  to  pieces  under  very  trivial  altera- 
tions of  temperature,  no  less  to  the  annoyance  than  loss  of  the  public  at  large.  Nor  can 
this  be  wondered  at,  when  it  is  remembered  that,  in  almost  every  tea-cup,  saucer,  or 

f)late  upon  our  tables,  the  laws  of  natural  combination  have  been  violated  by  the  preva- 
ence  oi  an  artificial  and  incompatible  form  of  arrangement,  the  work  of  sheer  ignorance 
and  chance.  So  far  as  our  investigations  have  yet  gone,  it  appears  that  kaolin,  or  china 
clay,  has  arisen  from  the  decomposition  of  felspar  under  two  different  conditions ;  for  the 
resulting  compound  is  not  alike  in  both  cases ;  though  to  what  cause  this  difference  can 
be  ascribed  we  are  unable  with  certainty  to  say.  Felspar,  in  it  original  state,  has  exactly 
the  same  composition  as  anhydrous  alum,  with  this  exception,  that  in  the  one  case  the 
bases  are  united  to  sulphuric,  and  in  the  other  to  silicic  acid.  Felspar,  therefore,  con- 
sists of  one  atom  of  potash  and  one  of  silica,  united  to  two  atoms  of  alumina  and  three 
of  silica ;  or,  in  other  words,  it  is  formed  of  the  silicate  of  potash  and  the  silicate  of 
alumina,  combined  in  the  ratio  of  one  atom  of  the  former  to  two  of  the  latter.  Now,  it 
is  found  that,  when  felspar  is  long  exposed  to  the  action  of  the  weather,  it  becomes 
disintegrated  and  falls  into  a  state  of  powder,  which,  ultimately,  by  absorbing  water, 
assumes  a  pasty  consistence,  and  thus  forms  the  article  called  china  claj^  The  nature  of 
this  decomposition  is  not,  however,  uniform  or  invariable,  for  analysis  proves  that  the 
residuary  produce  has  not  always  the  same  composition.  When  felspar  decomposes  in 
an  absolutely  wet  or  rainy  atmosphere,  the  silicate  of  potash  would  appear  to  be  simply 
washed  away  by  the  excess  of  water ;  and,  in  this  case,  the  resulting  clay  has  a  composi- 
tion of  three  atoms  of  silica  and  two  of  alumina ;  but,  when  merely  a  moist  atmosphere 
has  existed,  then  the  silicate  of  potash  itself  seems  to  become  decomposed,  probably  by 
carbonic  acid,  thus  leaving  the  whole  of  the  silica  united  to  the  alumina ;  the  potasn 
then  escaping  as  a  carbonate.  Under  such  circumstances,  we  have  found  china  clay  to 
consist  of  four  atoms  of  silica  and  two  of  alumina ;  or,  what  is  the  same  thing,  of  two  of 
acid  and  one  of  base.  Of  course  an  alternating  atmosphere  would  produce  a  mixture 
of  these  ;  and  such  layers  may  actually  be  traced  in  many  specimens  of  clay,  as  though 
the  summer  and  winter  portions  of  the  year  had  each  rarnished  a  distinctly  separate 
amount  of  decomposed  felspar.  But  felspar  is  not  the  only  source  from  whence  our  sili- 
cate of  alumina  has  been  formed ;  as  there  are  many  other  minerals  which,  by  the  action 
of  the  atmosphere,  furnish  clays  of  different  compositions :  thus,  the  substances  known 
to  mineralogists  under  the  names  leucite,  albite,  analeime,  nepheline,  mesotype,  and 
sodalite,  all  yield  silicate  of  alumina,  which  contains,  indeed,  various  proportions  of  the 
two  ingredients,  but  is  nevertheless,  in  a  commercial  sense,  clay.  In  point  of  fact  even 
granite  has  contributed  its  quota  to  the  clay  formation,  for  though  slowly  and  imper- 
fectly, yet  in  time  it  crumbles  down  into  supersilicate  of  alumina :  as  may  be  noticed 
by  carefully  examining  the  once  smooth  surface  of  the  granite  on  Waterloo  and  London 
Bridges,  which  is  gradually  assuming  a  cavernous  character.  With  such  evidence  be- 
fore us  of  the  infinite  variety  existing  in  clay,  it  is  surely  high  time  that  the  attention 
of  manufacturers  was  directed  to  the  necessity  of  analyzing  this  substance,  and  adding 
to  it  neither  more  nor  less  silica  than  is  sufficient  to  produce  a  useful  atomic  compound. 
The  proper  proportion  might  soon  be  arrived  at  by  a  few  carefully  conducted  experi- 
ments, after  which  the  whole  of  the  uncertainty  now  connected  with  differences  in  the 
material  would  vanish  for  ever,  and  with  it  no  small  amount  of  the  loss  occasionally 
caused  by  earthenware  spoilt  or  broken  in  the  kiln. 

To  determine  the  quantity  of  alumina  in  clay,  a  given  weight  of  this  substance,  say 
100  grs.,  well  dried  and  in  fine  powder,  should  be  mixed  with  double  its  weight  of  fluor 
spar,  also  in  fine  powder,  then  the  mixture  placed  in  a  platinum  or  leaden  vessel,  and 
about  400  grs.  of  strong  sulphuric  acid  poured  over  it.  Next  expose  the  whole  to  a  heat 
of  from  212°  to  250°  Fahr.  for  half  an  hour;  then  add  three  or  four  ounces  of  water,  and 
throw  the  mixture  on  a  filter,  adding  a  little  water  at  the  end  of  the  filtration,  so  as  to  ob- 
tain the  whole  of  the  soluble  matter.  To  the  filtered  fluid  add  now  an  excess  of  a  solu- 
tion of  ammonia,  by  which  the  alumina  will  be  precipitated ;  and  this,  after  being  well 
washed  on  a  filter,  and  dried  at  a  red  heat,  must  have  its  amount  determined  by  the  bal- 
ance. If,  however,  the  precipitate  thrown  down  by  ammonia  has  a  deep  yellow  or  red 
colour,  the  presence  of  iron  is  indicated ;  and  this  must  be  removed  before  drying  the  alu- 
taina.     For  this  purpose^  a  quantity  of  tartaric  acid  should  be  added,  so  as  to  redissolve 


480 


CLAY. 


the  mixed  precipitate,  and  the  solntion  slightly  supersaturated  with  carbonate  of  soda; 
when,  OQ  adding  hydrosulphate  of  ammonia,  tlie  iron  will  separate  as  a  black  sulphuret, 
leaving  the  alumina  still  m  solution ;  from  whence  it  may  be  obtained  by  evaporating 
the  whole  to  dryness,  heating  red  hot,  and  then  washing  away  the  alkaline  salts  by 
hot  water ;  the  alumina  is  then  left  pure,  and,  after  being  dried,  may  be  weighed.  As 
the  presence  of  iron  in  clay  is  a  serious  drawback,  the  quantity  of  black  sulphuret 
formed  becomes  a  good  indication  of  the  impurity  of  the  sample  imder  examination, 
and  is  therefore  worthy  of  notice. 

Although  the  proportion  of  alumina  in  clay  is  the  chief  commercial  feature  required 
by  the  makers  of  earthenware,  yet  it  may  sometimes  be  requisite  to  determine  also  the 
amount  of  silica  present;  which  may  be  done  by  fusing  together  in  an  iron  crucible  or 
pan,  at  a  full  red  heat,  one  part  of  the  clay  in  question  with  three  parts  of  pure  potash, — 
both  being  in  fine  powder,  and  carefully  mixed  before  fusion.  The  fused  mass  must^ 
when  cold,  be  boiled  for  some  time  in  water,  until  it  is  thoroughly  disintegrated ;  when 
it  should  be  poured  into  a  porcelain  vessel,  and  supersaturated  with  muriatic  acid ; 
after  which,  by  evaporating  to  dryness,  a  residue  will  be  obtained,  that,  after  careful 
washing  with  boiling  water,  consists  merely  of  the  silica  contained  in  the  clay  in  ques- 
tion. After  being  heated  red  hot,  it  may  be  weighed  as  usual.  If  lime  be  suspected  to 
exist  with  the  alumina  in  clay,  this  may  be  separated,  when  in  solution,  by  means  of 
tartaric  acid  and  carbonate  of  soda,  as  above  indicated ;  for  in  such  cases,  the  lime 
will  fall  at  once  as  a  carbonate,  leaving  the  alumina  behind  in  the  fluid.  Independent, 
however,  of  the  defects  in  British  earthenware  due  to  the  non-atomic  admixture  of  its 
ingredients,  there  are  others  arising  out  of  the  nature  of  the  ingredients  themselves ; 
so  that,  taken  as  a  whole,  we  cannot  avoid  coming  to  the  unpleasant  conclusion,  that, 
in  the  great  arena  of  competition  at  the  Crystal  Palace,  England  is  decidedly  beaten  in 
the  manufacture  of  fine  earthenware,  even  by  countries  greatly  its  inferiors  in  capital, 
intelligence,  and  natural  resources.  France,  Germany,  Sweden,  Denmark,  Spain,  Rus- 
sia, Turkey,  and  China,  all  exhibited  porcelain  of  a  quality  unmatched  by  anything 
in  the  British  department,  and  no  more  lamentable  contrast  could  possibly  be  drawn 
than  between  the  chemical  apparatus  from  Saxony  and  the  clumsy  abortions,  which, 
under  that  name,  disfigured  some  of  the  compartments  claimed  by  one  or  two  of  our 
Staffordshire  manufacturers.  In  the  one  case  we  find  a  really  handsome,  light,  and 
elegant  article,  the  glaze  of  which  has  evidently  penetrated  throughout  the  entire  sub- 
stance of  the  body,  and  has  converted  the  whole  into  a  uniform  vitrification ;  in  the  other, 
a  thick,  coarse,  opaque,  and  spongy  mass,  is  merely  glazed  over  on  its  extreme  surface  by 
a  fusible  compound,  having  no  properties  in  common  with  the  body  of  the  article,  and 
endowed  with  very  diflferent  powers  of  expansibility  by  heat ;  so  that,  after  being  used 
a  few  times,  the  glaze  becomes  cracked  and  shivered  in  a  thousand  directions,  as  may  be 
seen  by  examining  the  earthenware  in  common  use  throughout  Great  Britain.  i»ior  is 
the  unsightly  appearance  caused  by  this  cracking  of  the  glaze  the  whole  evil;  for 
earthen  vessels  thus  flawed  acquire  the  property  of  absorbing  fluids  into  their  pores, 
and  can  never  afterwards  be  thoroughly  cleaned.  In  spite,  therefore,  of  "  warranted 
not  to  absorb,"  and  other  groundless  legends  of  similar  import,  imprinted  upon  many 
British  goods,  a  piece  of  really  non-absorbent  earthenware,  for  common  use,  is  an  actual 
curiosity  in  tliis  country,  and  invariably  suggests  tlie  idea  of  a  foreign  origin.  Now 
this  defect  can  be  remedied  only  in  two  ways ;  and,  as  our  manufacturers  have  vainly 
endeavoured  to  carry  out,  practically,  one  of  these  ways,  we  are  not  without  hopes  of 
persuading  them  to  try  the  other.  If  a  glazing  material  could  be  discovered,  the  ex- 
pansions and  contractions  of  which,  by  heat,  exactly  corresponded  with  those  of  the 
biscuit  ware,  or  silicate  of  alumina,  under  the  same  influence,  then  the  present  system 
of  covering  a  spongy  body  by  a  coating  of  vitrifiable  glaze  would  answer  the  desired  in- 
tention well  enough  ;  for  to  the  cheapness  and  durability  of  earthenware  would  thus  be 
superadded  the  cleanliness  of  glass.  But  this  desideratum  has  been  sought  for,  over  and 
over  again,  during  the  last  half  century,  and  nothing  but  disappointment  has  resulted. 
In  proof  of  which  we  have  only  to  ask — where  is  that  glazed  earthen  vessel,  which, 
though  made  expressly  for  the  use  of  the  apothecary,  will  retain  oil,  after  being  two  or 
three  times  heated  and  cooled  ?  The  answer  to  this  question  must  be  our  argument  in 
favour  of  abandoning  such  a  system  of  glazing,  and  adopting  the  only  other  mode  by 
which  a  non-absorbent  pottery  ware  can  be  fabricated.  The  body  of  the  ware  itself 
must  undergo  a  semivitrification,  as  happens  with  the  finest  kind  of  china ;  so  that,  even 
if  by  long  use  the  glaze  come  to  be  fairly  worn  off',  still  the  non-absorbent  principle  would 
remain  as  perfect  as  at  first.  We  know  that  this  is  impracticable  under  existing  circum- 
stances; and  that,  so  long  as  the  present  empirical  mode  of  compounding  the  materials 
of  which  the  body  of  the  ware  is  made  continues,  no  chance  of  improvement  remains. 
A  mixture  of  silica  and  alumina,  in  tlie  proportion  of  four  atoms  of  the  former  to  one  of 
the  latter,  would  bear  or  require  a  certain  quantity  of  fusible  material  to  induce  semi- 
vitrification throughout  the  mass;  but  a  compound  of  three  atoms  of  silica  and  one  of 


CLAY. 


431 


alumina  would  probably  be  melted  down  into  a  worthless  slag  by  exactly  the  same  ad- 
dition.    Here  then  lies  the  root  of  that  difficulty  which  has  hitherto  so  injuriously  re- 
stricted the  employment  of  felspar  and  other  vitrifiable  bodies  in  the  fabrication  of  British 
earthenware.    Those  who  have  attempted  to  use  such  substances  have  occasionally  suc- 
ceeded to  adnairation ;  and  nothing  but  the  uncertainty  of  the  result,  and   repeated 
failures,  have  induced  them  to  abandon  the  employment  of  a  class  of  articles  which,  if 
capable  of  being  controlled,  every  intelligent  manufacturer  admits  would  confer  perfec- 
tion on  his  art     But  it  is  a  great  mistake  to  suppose  that  these  inequalities  of  action 
arise  out  of  some  peculiarity  in  the  vitrifiable  materials  themselves,  or  are  in  any  way 
the  work  of  chance.     The  materials  are,  or  ought  to  be,  uniform,  and  certainly  can  be 
made  so,  whilst,  for  the  rest,  there  is  no  such  thing  as  chance  in  nature, — the  laws  of 
chemistry  are  not  accidental  or  variable,  they  are  immutable.    We  have  shown,  however, 
that  clays  not  only  differ  from  each  other,  but,  as  it  were,  from  themselves ;  since,  from 
the  same  pit,  and  within  a  few  inches  of  the  same  spot,  clays  of  very  contrary  charac- 
ters may  be  procured.     Plasticity  is  no  more  an  indication  of  the  presence  or  purity  of 
clay,  than  sweetness  is  a  test  of  sugar.     In  a  rough  way  both  these  qualities  have  a 
value;  but  the  arts  are  now  fast  approaching  an  epoch,  when  all  such  fallacious  aids 
must  give  place  to  the  guidance  of  philosophy ;  and  the  sooner  our  manufacturers  be- 
come convinced  of  this  grand  truth  the  better  for  themselves  and  their  country.     The 
propriety  of  knowing  the  exact  composition  of  the  raw  materials  employed  in  any  art  or 
manufacture  does  not,  indeed,  admit  of  dispute — it  is  imperative ;  and  hence  we  are  the 
more  astonished  at  the  scantiness  of  information  respecting  the  analysis  of  so  important 
a  production  as  clay.    In  face  of  such  apathetic  ignorance,  would  any  one  beheve  tiiat> 
independently  of  an  immense  home  consumption,  our  exports  of  earthenware  last  year 
amounted  to  a  miUion  sterling  ?    Had  the  clays  of  this  country  been  of  a  tolerably  uni- 
form composition,  like  some  of  those  in  China  and  on  the  continent,  of  course  mere 
practice  would  long  ago  have  enabled  our  potters  to  produce  articles  of  the  highest 
quality.     But  surely  this  is  a  sorry  compliment  to  men  surrounded  by  all  the  resources 
of  science  and  capital     Where  there  is  no  difficulty  there  can  be  but  little  merit,  and 
still  less  profit     It  is  the  great  glory  of  British  enterprise  and  industry  to  despise  so 
low  and  facile  a  position.     Our  manufacturers  must  meet  and  overcome  the  trivial 
impediments  connected  with  variations  in  the  clay  they  purchase,  and,  by  properly  ad- 
justing the  other  materials  (so  as  to  bring  on  exactly  the  due  amount  of  vitrification 
needed  in  the  body  of  the  ware),  produce,  from  any  kind  of  clay,  articles  identical  with 
those  which  other  nations  fabricate  from  the  very  finest  clays  only.     With  the  pro- 
digious commercial  and  other  advantages  possessed  by  Great  Britain,  the  world  at  large 
ought  to  expect  this  at  our  hands,  and  not  the  sub-mediocre  workmanship  displayed  iu 
the  Great  Exhibition. 

Before  quitting  this  subject,  a  few  remarks  upon  the  substances  used  in  the  formation 
of  glazes  may  not  be  inappropriate.  The  million  is  still  supplied  with  earthenware, 
the  glaze  of  which  contains  lead,  and  is,  consequently,  dangerous  to  healtli,  though, 
when  well  burned  on,  this  danger  is  greatly  diminishec^  from  the  increased  insolubility 
of  the  silicate  of  lead  in  weak  acids.  It  is,  however,  an  objectionable  mode  of  glazing 
earthenware,  and  requires  to  be  watched  with  caution,  more  especially  where  borax  is 
used  at  the  same  time,  for  the  borate  of  lead  is  more  easily  acted  on  than  the  silicate.  It 
has  been  lately  suggested  that  oxide  of  zinc  would  form  a  sufficiently  fusible  compound 
with  silica,  and  is  cheap  enough  to  supplant  oxide  of  lead  in  the  glazing  of  common 
earthenware.  The  latter  assertion  is  undoubtedly  true,  and,  although  we  entertain  some 
suspicions  as  to  the  easy  fusibility  of  silicate  of  zinc,  yet  this  is  precisely  one  of  those 
problems  which,  from  their  important  sanitary  bearing,  deserve  immediate  investigation. 
On  the  continent  a  very  pure  kind  of  felspar,  mixed  probably  with  a  little  carbonate  of 
baryta  and  oxide  of  tin,  forms  the  only  glaze  used  upon  porcelain  and  the  china  vessels 
intended  for  chemical  purposes.  Tliis  glaze  is  practically  perfect  It  is  so  hard  as  to 
withstand  the  attack  of  a  file,  and  it  resists  the  action  of  the  strongest  acids  and  alkalis 
at  all  temperatures  below  300°  Fahr.-— the  hydrofluoric  acid  and  its  salts  alone  ex- 
cepted. In  the  French,  Saxon,  and  Prussian  departments  of  the  Crystal  Palace,  there 
were  several  good  specimens  which  illustrated  the  value  of  this  kind  of  glaze 

Amongst  the  English  goods— and  chiefly  those  fi-om  Staffordshire — were  a  variety 
of  articles  made  in  what  is  termed  Parian,  a  compound,  the  unfitness  of  which  for 
statuary  purposes  we  now  briefly  animadvert  upon,  with  reference  however  only  to  its 
employment  in  the  higher  branches  of  Decorative  Art.  The  employment  of  this  ma- 
tenal,  or  indeed  any  other  form  of  alumina  where  sharpness  and  symmetry  are  wanted, 
cannot  be  sufficiently  condemned,  since  it  is  totally  contrary  to  the  natural  properties 
of  alumina,  and  betrays  infinite  ignorance  regarding  first  principles.  The  philosophical 
mind  of  Wedgewood  would  have  revolted  at  so  palpable  an  absurdity ;  for  not  alone 
was  he  well  acquainted  with  the  continuous  contractility  of  aluminous  compounds,  but» 
taking  advantage  of  that  knowledge,  he  was  able  to  construct  an  instrument  for 
measuring  high  degrees  of  heat>  which,  although  not  rigidly  perfect,  is  at  this  day  still 


I 


f! 


m 


432 


COAL. 


found  the  only  available  guide  for  furnace  operations  on  a  large  scale.  And  the  value 
of  this  instrument  or  pyrometer,  as  it  is  termed,  depends  upon  the  fact,  that  the  longer 
and  higher  the  temperature  to  which  clay  is  exposed,  the  smaller  it  becomes.  Isow, 
bearing  in  mind  that  earthenware  is  an  extremely  bad  conductor  of  heat,  let  us  imagine 
the  Greek  Slave,  for  example,  correctly  modelled  in  clay  or  Parian,  and  subjected  to 
the  heat  of  a  porcelain  furnace.  The  smaller  portions  of  the  figure,  as  the  nose,  eye- 
lids, fingere,  <fec.,  would  receive  much  more  of  the  impress  of  the  fire  than  the  larger 
ones, — as  the  head,  shoulders,  <fec. ;  consequently,  however  symmetrical  the  original 
model  might  have  been,  the  ex-tra  contraction  in  the  smaller  parts  must  destroy  every 
thing  like  anatomical  harmony  and  beauty.  Tlie  fingers  would  become  short  and 
dumpy,  and  the  nose  flat  and  snubbed.  But  this  is  a  small  part  of  the  mischief,  for  since 
clay,  when  burnt,  is  a  bad  conductor  of  heat,  and  the  action  of  the  fire  is  from  without 
to  within,  the  exterior  of  the  figure  must  contract  vastly  more  than  the  interior ;  con- 
sequently, the  outside  becoming  too  small  for  the  inside,  a  series  of  cracks  or  fissures 
make  their  appearance  to  compensate  for  the  inequality.  These,  of  course,  are  filled 
up  by  a  subsequent  operation  ;  but,  it  is  needless  to  add,  at  the  expense  of  every  thing 
which  would  have  rendered  the  result  valuable  as  a  work  of  art  The  general  appearance 
of  the  Parian  figures  shoAvn  in  the  Exhibition  bears  us  out  in  this  censure  ;  for  the 
features  are  universally  flat,  soulless,  and  devoid  of  expression ;  nor  can  we  imagine  a 
more  hopeless  task  than  attempting  to  remedy  this  defect. 

CLOTH,  MANUFACTURE  OF.  See  Cotton,  Flax,  Weaving,  Wool. 
CLOTH-BINDING.  Nothing  places  in  so  striking  a  point  of  view  the  superior 
taste,  judgment,  and  resources  of  London  tradesmen  over  those  of  the  rest  of  the  world, 
than  the  extensive  substitution  which  they  have  recently  made  of  embossed  silks  and 
calicoes  for  leather  in  the  binding  of  books.  In  old  libraries,  cloth-covered  boards 
indeed  may  occasionally  be  seen,  but  they  have  the  meanest  aspect,  and  are  no  more 
to  be  compared  with  our  modern  cloth-binding,  than  the  jupon  of  a  trull  with  the  ballet 
dress  of  Taglioni.  The  silk  or  calico  maj  be  dyed  of  any  shade  which  use  or  fancy  may 
require,  impressed  with  gold  or  silver  foil  in  every  form,  and  variegated  by  ornaments 
in  relief,  copied  from  the  most  beautiful  productions  in  nature.  This  new  style  of 
binding  is  distinguished  not  more  for  its  durability,  elegance,  and  variety,  than  for  the 
economy  and  dispatch  with  which  it  ushers  the  offspring  of  intellect  into  the  world. 
For  example,  should  a  house  eminent  in  this  line,  such  as  that  of  Westleys,  Friar- 
street,  Doctor's-commons,  receive  6000  volumes  from  Messi*s.  Longman  <fe  Co.  upon 
Monday  morning,  they  can  have  them  all  ready  for  publication  within  the  incredibly 
short  period  of  two  days ;  being  far  sooner  than  they  could  have  rudely  boarded  them 
upon  the  former  plan.  Tlie  reduction  of  price  is  not  the  least  advantage  incident  to 
the  new  method,  amounting  to  fully  50  per  cent,  upon  that  with  leather. 

The  dyed  cloth  being  cut  by  a  pattern  to  the  size  suited  to  the  volume,  is  passed 
rapidly  through  a  roller  press,  between  engraved  cylinders  of  hard  steel,  whereby  it  re- 
ceives at  once  the  impress  characteristic  of  the  back,  and  the  sides,  along  with  embossed 
designs  over  the  surface  in  sharp  relief  The  cover  thus  rapidly  fashioned,  is  as  rapidly 
applied  by  paste  to  the  stitched  and  pressed  volume ;  no  time  being  lost  in  mutual  ad- 
justments ;  smce  the  steel  rollers  turn  off"  the  former  of  a  shape  precisely  adapted  to  the 
latter.  Hard  glazed  and  varnished  calico  is  moreover  much  less  an  object  of  depreda- 
tion to  moths  and  other  insects,  than  ordinary  leather  has  been  found  to  be. 

CLOTH-DRESSING,  by  Heycock  of  Leeds,  without  stretching  the  warp-threads  or 
creasing  the  cloths  from  list  to  list.  He  lays  several  pieces  of  cloth  m  an  extended 
state  above  one  another  upon  a  wooden  platform,  until  a  pile  of  a  suitable  thickness  is 
formed,  a  perforated  plate  is  then  brought  down  on  the  cloth  by  screws,  and  steam  is 
admitted  into  a  hollow  chamber  beneath,  from  which  it  penetrates  all  the  folds  of  the 
cloth,  but  is  confined  at  the  sides.     It  seems  to  be  a  purpose-like  invention. 

COAL.  Under  Pitcoal,  the  composition  of  several  excellent  coals  is  stated,  with 
their  peculiar  qualities,  as  analyzed  by  me  ;  such  as  the  Llangenneck,  Powell's  Duflfryn 
steam  coal,  the  Blackley  Hurst  coal,  Lancashire,  the  Varley  Rock  vein  coal,  near 
Pontypool,  Ac.  The  quantity  of  coals  and  culm  exported  in  1850  was  3,351,880  tons, 
and  in  1851,  3,4'7'7,060  tons  ;  'declared  value  respectively,  1,284,224/.  and  1,302,025/.  ^ 

COAL  GAS.  From  what  is  generally  admitted  concerning  the  impurities  which  exist 
in  crude  coal-gas,  it  must  be  evident  to  those  conversant  with  the  principles  of  chemistry 
that  these  impurities  can  never  be  thoroughly  removed  by  any  single  reagent^  for  some  of 
them  possess  affinities  diametrically  opposite  to  the  others.  Thus,  any  means  employed 
tx)  absorb  carbonic  acid  and  sulphuretted  hydrogen  gases  would  leave  the  ammonia  free ; 
whilst  an  agent  capable  of  combining  with  the  latter,  would  not  at  all  aff^ectthe  former 
impurities.  Hence  the  process  of  coal  gas  purification,  as  now  carried  on  at  the  best 
gas  works,  is  divided  into  two  distinct  parts.  By  one  of  these  the  whole  of  the  am- 
monia and  a  portion  of  the  carbonic  acid  and  sulphuretted  hydrogen  are  taken  away,  by 
the  other,  the  remainder  of  the  carbonic  acid  and  sulphuretted  hydrogen  are  totally  re- 


COAL. 


433 


moved ;  so  that  the  gas  ultimately  passes  forth  to  the  consumer  free  from  all  contami- 
nation either  by  ammonia,  carbonic  acid,  or  sulphuretted  hydrogen  gas.  And  the  ab- 
sence of  these  impurities  may  at  any  time  be  demonstrated  by  applying  the  following 
simple  tests :  —  litmus  paper,  slightly  reddened  by  an  acid,  will  undergo  no  change 
when  held  for  a  few  minutes  in  a  current  of  the  gas ;  this  proves  the  absence  of  am- 
monia, for  otherwise  the  paper  would  become  blue.  Paper,  dipped  into  a  solution  of 
the  acetate  of  lead,  and  held  in  a  current  of  the  gas,  will  remain  white,  which  shows 
that  the  gas  is  destitute  of  sulphuretted  hydrogen,  as,  under  contrary  circumstances, 
it  would  assume  a  deep  brown  or  black  hue.  Lastly,  if  the  gas  be  allowed  to  blow  for 
a  few  minutes  through  a  clear  solution  of  lime  in  water,  the  solution  will  not  become 
milky  and  turbid,  as  it  would  do  if  carbonic  acid  were  present  in  the  gas.  No  coal  gas 
which  does  not  vindicate  its  purity  by  resisting  the  analytical  powers  of  the  above 
tests  can  be  regarded  as  sufliciently  good  for  the  purposes  of  illumination  and  heating. 
To  separate  the  ammonia  from  coal  gas,  a  variety  of  modes  is  at  present  in  use ; 
thus,  Mr.  Lowe  employs  cold  water  minutely  divided  in  an  apparatus  which  he  terms  a 
"  scrubber,"  and  which  is  perfectly  analogous  to  the  cascade  chimiqxie  of  Clement  Des- 
With  a  similar  view  Mr.  Palmer  mixes  the  gas  with  steam,  and  then  subjects 


ormes. 


the  mixture  to  a  condensing  temperature,  so  as  to  obtain  water,  minutely  divided  in 
drops,  like  rain  or  dew,  and  therefore  presenting  a  considerable  surface  for  chemical 
action.  Mr.  Johnson  prepares  a  compound,  consisting  of  sulphate  and  biphosphate  of 
lime,  by  acting  on  burnt  bones  with  sulphuric  acid  ;  and  this  he  disposes  m  trays,  so  as 
to  absorb  the  ammonia  and  produce  a  mixture  of  sulphate  of  ammoma  and  phosphate  of 
lime,  which,  as  might  be  expected,  he  finds  an  extremely  efl[icient  fertilizing  agent.  Mr. 
Laming  employs  a  solution  of  chloride  of  calcium  or  muriate  of  lime,  absorbed  into  saw- 
dust, which  he  disposes  in  the  same  manner  as  that  followed  by  Mr.  Johnson,  and  by 
which  the  muriate  of  lime  is  gradually  decomposed  with  the  formation  of  carbonate  of 
lime  and  muriate  of  ammonia, — the  resulting  compound  being  either  valuable  as  a 
manure,  or  as  a  source  for  the  manufacture  of  sal  ammoniac.  Sulphate  of  lime,  and 
various'  other  earthy  metallic  salts,  have  also  been  proposed  and  employed, — such 
as  the  sulphates  of  magnesia,  alumina,  zinc,  iron,  and  manganese,  and  the  chlorides  of 
the  same  metals.  With  the  exception  of  the  sulphate  of  liine,  they  do  not,  however, 
seem  to  possess  any  advantage  over  the  modes  we  have  mentioned  as  now  in  use  for  the 
absorption  of  ammonia ;  and  hence  it  may  be  as  well  to  examine  more  minutely  the 
actions  of  those  methods,  and  their  effects  upon  the  gas  undergoing  purification. 
The  process  of  Lowe  is  extremely  simple  in  theory,  and,  where  the  saving  of  the  am- 
monia is  not  an  object  of  importance,  has  much  to  recommend  it.  Here  the  ammonia 
is,  so  to  say,  washed  out  by  means  of  water ;  and  the  application  of  the  scrubber  may 
either  be  made  before  or  after  the  other  impurities  are  taken  away,  with,  however,  this 
difference  in  the  result : — if  the  gas,  after  c^^uitting  the  condenser,  is  passed  at  once  into 
the  lime  purifier,  and  the  scrubber  applied  afterwards,  nothing  but  ammonia  will 
be  removed  by  the  water ;  but  if  the  scrubber  be  emploj'ed  in  the  first  instance,  then, 
with  every  atom  of  ammonia  taken  away,  one  of  carbonic  acid  and  sulphuretted  hydro- 
gen will  follow,  and  hence  a  great  economy  of  lime  in  this  way  arises ;  for  the  ammonia, 
though  itself  an  impurity,  thus  becomes  a  purifying  agent,  and  the  liquid  from  the 
scrubber  consists,  not  of  aqueous  ammonia  merely,  but  of  a  solution  of  carbonate  and 
hydrosulphate  of  ammonia.  It  is,  however,  very  difficult  to  separate  the  whole  of  the 
ammonia,  either  free  or  combined  with  carbonic  acid,  by  Lowe's  scrubber,  without  the 
application  of  a  very  large  body  of  water ;  and  it  has  been  suggested,  that  excessive 
ablution  diminishes  considerably  the  illuminating  power  of  coal  gas.  This  circum- 
stance, if  true and  it  is  far  from  improbable — demonstrates  the  necessity  of  limiting 

the  action  of  water  upon  gas,  and  must,  in  some  degree,  interfere  with  the  employment 
of  an  otherwise  invaluable  instrument  of  purification.  The  plan  of  Palmer  is  precisely 
similar  in  its  effect  to  the  scrubber  of  Lowe,  but  more  costly,  and,  except  when  con- 
ducted with  great  care,  less  efficacious,  as  the  entire  success  depends  upon  the  perfection 
of  the  condensation ;  for,  unless  the  condensed  water  be  cooled  down  to  the  mean  tem- 
perature of  the  atmosphere,  little  or  no  ammonia  will  combine  with  it ;  and  there  is, 
moreover  a  still  greater  danger  of  injuring  the  light-giving  power  of  the  gas  by  con- 
densed steam,  than  by  an  equal  weight  of  cold  water.  This  method  cannot,  therefore, 
be  considered  as  equal  to  the  former,  more  especially  when  coal  gas,  of  low  specific  gra- 
vity, is  to  be  purified.  The  mere  recital  of  Johnson  s  process  almost  details  its  mode  of 
action  •  and  it  would  scarcely  be  necessary  to  say  more  concerning  it,  but  for  the  contrast 
it  presents  to  that  of  Laming,  and  the  substances  before  alluded  to.  If  the  phosphate  of 
lime  or  bone  earth,  mentioned  as  part  of  Johnson's  mixture,  be  regarded  as  a  sponge  for 
holding  the  sulphuric  acid  which  he  employs,  then  the  ammonia  is  taken  up  from  the  gas 
by  simple  elective  affinity  with  the  production  of  sulphate  of  ammonia ;  and  this  is,  be- 
yond doubt,  a  true  explanation  of  the  modMS  operandi  in  Johnson's  case.  Here,  however, 
it  will  ])e  noticed  that  nothing  but  ammonia  is  removed,  for  the  carbonic  acid  and  sul- 

VoL.  L  8  K 


434 


COAL. 


COAL. 


435 


*1 


phuretted  hydrogen  remain  unaflfected ;  consequently  this  system  might  be  employed 
either  before  or  after  lime  purification.  Now,  Laming  s  plan  differs  altogether  from  this, 
and,  as  will  readily  be  s.een,  admits  of  application  only  before  lime  purification.  The  foul 
coal  gas  from  the  condenser  contains  carbonate  of  ammonia  in  a  gaseous  condition ;  and 
it  has  just  been  shown,  that  the  process  of  Laming  depends  upon  the  use  of  muriate  of 
lime.  But  at  the  ordinary  temperature  of  this  country  these  two  substances  are  incompa- 
tible with  each  other ;  and,  consequently,  as  fast  as  the  carbonate  of  ammonia  is  brought 
by  the  current  of  gas  into  contact  with  the  muriate  of  lime,  mutual  decomposition  en- 
sues, and  both  the  ammonia  and  carbonic  acid  are  solidified ;  the  former  becoming  con- 
verted into  muriate  of  ammonia,  and  the  latter  into  carbonate  of  lime,  by  an  interchange 
of  elements  with  the  muriate  of  lime  used  in  the  process ;  therefore  the  result  differs 
thus  far  from  that  of  Johnson, — that  carbonic  acid  as  well  as  ammonia  is  taken  from  the 
gas,  and  consequently  a  saving  of  lime,  or  other  purifying  material,  eflfected:  of  course 
sulphate  of  lime  would  act  in  the  same  way,  though  less  powerfully ;  whereas  metallic 
salts,  in  general,  having  more  affinity,  after  decomposition,  for  sulphuretted  hydrogen 
than  for  carbonic  acid,  will  produce  an  economy  of  lime  by  removing  the  former  and 
not  the  latter  impurity.  Such,  then,  is  a  descriptive  outline  of  the  methods  actually 
followed  at  the  present  day  for  the  purification  of  coal  gas  from  the  ammonia  it  con- 
tains; and  although  seemingly  abundant  enough  to  have  exhausted  the  subject,  yet 
there  is  still  an  extensive  field  open  to  improvement  even  here. 

Amongst  the  large  class  of  ammoniacal  compounds  known  to  chemists,  it  seems 
strange  that  no  one  has  yet  taken  advantage  of  that  interesting  series  which  sufifers 
decomposition  by  the  mere  application  of  a  moderate  temperature,  evolving  at  the  same 
time  pure  ammoniacal  gas,  and  yielding,  as  a  residue,  the  substance  originally  employed 
for  purification.  "We  shall  enumerate  but  one  or  two  substances  of  this  kmd  for  the 
purpose  of  illustrating  our  argument,  leaving  the  whole  question  as  open  as  ever  to 
practical  investigation.  When  phosphate  of  magnesia  is  exposed  to  the  action  of 
ammoniacal  gas,  its  acid  becomes  divided  in  such  a  way  as  to  produce  the  triple  salt 
called  ammoniaco-phosphate  of  magnesia ;  and  as  this  is  a  much  more  insoluble  substance 
than  the  simple  phosphate,  we  have  only  to  pass  impure  coal  gas  through  a  solution  or 
aqueous  mixture  of  the  latter,  to  insure  the  precipitation  of  all  the  ammonia  contained 
in  the  gas ;  whilst,  at  the  same  time,  the  compound  which  it  has  formed  with  the 
phosphate  of  magnesia  is  very  easily  decomposed,  so  as  to  admit  of  a  continuous  usage 
of  the  same  material ;  for  at  a  temperature  considerably  below  a  red  heat,  the  triple 
phosphate  of  magnesia  parts  with  all  its  ammonia,  and  becomes  simple  phosphate  again, 
with  the  renewal  of  its  primitive  power  as  an  absorber  of  ammoniacal  vapours.  But 
the  ammonia  which  is  expelled  by  heat  might  very  easily  be  condensed  in  water,  and 
thus  originate  a  valuable  commodity  for  the  market.  By  this  means  there  can  be  no 
doubt  phosphate  of  magnesia  might  be  employed  over  and  over  again  in  the  purifica- 
tion of  coal  gas,  whilst  the  ammonia  procured  from  it  would  contain  neither  sulphur 
nor  any  other  impurity.  An  iron  vessel  might  be  used  for  the  distillation ;  and  if  too 
high  a  heat  was  not  given  to  the  phosphate  of  magnesia,  its  purifying  action  would 
remain  unaltered ;  thus  presenting  altogether  a  fair  opening  for  the  investment  of 
talent  and  industry.  Similarly,  boracic  acid  deserves  attention,  from  the  facility  with 
which,  even  at  the  temperature  of  boiling  water,  it  parts  with  the  greater  j)ortion  of 
any  ammonia  previously  united  to  it,  at  the  ordinary  heat  of  the  climate  in  this  country. 
It  ofFei-s,  consequently,  a  commodious  vehicle  for  collecting  and  conveying  the  ammonia 
of  gas  works  into  public  use,  without  the  risk  of  nuisance  or  loss.  Many  other  substances 
possessing  this  double  property  of  absorbing  and  giving  off  ammonia  by  a  trifling  change 
of  temperature  might  be  pointed  out ;  but  this  lies  beyond  our  province ;  it  is  the  prin- 
ciple only  which  we  attempt  to  elucidate,  with  a  view  to  its  practical  application  in 
gome  specific  instance. 

Presuming  that  the  impure  gas  has  had  all  its  ammonia  separated  by  proper  treat- 
ment, we  have  now  to  consider  in  what  way  the  carbonic  acid  and  sulphuretted  hydrogen 
may  be  most  easily  got  rid  of.  Lime  is  the  agent  commonly  selected,  and  all  things 
duly  admitted,  there  is  a  great  mass  of  evidence  in  its  favour, — so  much  so,  indeed,  that, 
until  lately,  it  has  had  no  competitor.  At  present,  however,  the  oxide  of  iron  is  be- 
coming a  formidable  rival ;  and  therefore  we  propose  to  examine  into  their  respective 
merits,  which,  after  all,  are  less  alike  than  might  be  supposed  in  two  substances  selected 
to  perform  one  and  the  same  operation.  When  properly  prepared  and  moistened,  lime 
removes  from  impure  coal  gas  both  carbonic  acid  and  sulphuretted  hydrogen  with 
extreme  energy,  and  consequently  eflFects  thorough  purification  after  the  ammonia  has 
been  got  rid  of.  Oxide  of  iron  combines  only  with  the  sulphuretted  hydrogen  con- 
tained in  the  gas,  and  not  with  the  carbonic  acid;  so  that  coal  gas  purified  in  this  way 
requires  subsequent  application  of  lime,  or  some  other  material  capable  of  combining 
with  carbonic  acid.  Thus  far,  therefore,  the  advantage  is  much  in  favour  of  lime.  But 
when  lime  has  absorbed  all  the  impurity  it  can  attract  from  coal  gas,  or,  in  technical 


phrase  becomes  "  foul,"  it  is  not  only  altogether  useless,  but,  much  worse  than  this,  it  is  a 
Berious  nuisance,  in  consequence  of  the  evolution  of  sulphuretted  hydrogen  the  moment 
it  comes  in  contact  with  atmospheric  air,  which  arises  from  the  action  of  the  atmo 
spheric  carbonic  acid  upon  the  hydrosulphate  of  lime  contained  in  the  foul  mass. 
Gas-lime  refuse  is  therefore  a  grave  inconvenience  to  many  gas  companies.  Now  with 
oxide  of  iron  no  such  inconvenience  is  felt ;  for  this  substance  in  uniting  with  sulphu- 
retted hydrogen  produces  a  compound  which  yields  no  noxious  or  unhealthy  emanations 
by  the  contact  of  air,  but  is,  under  such  influence,  simply  oxidized,  and  in  a  great  measure 
restored  to  its  primitive  power,  so  that  it  may  be  used  over  and  over  again,  ten,  twenty, 
or  even  thirty  times  in  succession.  These  peculiarities  give  the  oxide  of  iron  a  decided 
superiority  in  many  situations,  though  up  to  the  present  moment  its  practical  application 
has  been  extremely  limited.     When  lime  contained  in  a  purifier  has  ceased  to  purify 

fas,  the  general  impression  is  that  it  has  been  wholly  resolved  into  carbonate  and 
ydrosulphate  of  lime ;  but  this  is  very  far  indeed  from  being  the  case,  for  even  the 
foulest  lime  seldom  contains  less  than  one-fifth  of  all  its  lime  free  or  uncombined ;  and 
gas-lime  refuse  is  occasionally  to  be  had  so  imperfectly  saturated  that  fully  one-half  of 
the  linie  paid  for  by  the  gas  company  may  be  said  to  be  thrown  away.     In  the  first 
place,  it  18  not  customary  to  examine  the  lime  itself,  so  as  to  determine  its  chemical 
value  or  combining  proportion,  and  still  worse,  it  is  not  usual,  secondarily,  to  analyze 
the  lime  refuse  with  a  view  to  ascertain  how  much  lime  is  passing  away  unacted  on. 
As  both  of  these  desiderata  may  be  secured  without  the  application  of  any  great 
chemical  skill,  we  shall  proceed  to  give  a  brief  description  of  the  means  needed  to  solve 
the  trifling  problems,  beginning  with  the  lime  itself.     Having  selected  from  the  bulk  a 
fair  sample  of  lime,  let  this  be  ground  to  a  fine  powder  in  a  clean  and  dry  mortar ;  then 
weigh  out  100  grs.  of  the  powder,  and  place  it  in  a  tumbler  or  other  suitable  vessel, 
where  it  is  to  be  repeatedly  washed  with  a  warm  but  not  hot  solution  of  sal  ammoniac 
in  water, — the  temperature  being  about  80°  or  90°  Fahr.     Great  care  must  be 
taken  that,  in  washing  the  lime,  no  solid  particles  are  allowed  to  escape  with  the  ammo- 
niacal solution ;  and,  as  soon  as  it  is  observed  that  the  fluid  containing  the  sal  ammoniac 
ceases  to  restore  the  colour  of  reddened  litmus  paper,  after  it  has  been  poured  upon  the 
lime,  then  common  water  may  be  used  to  wash  the  remaining  lime ;  after  which  it 
must  be  dried  at  a  red  heat,  and  then  weighed ; — the  loss  will  indicate  the  amount  of 
pure  lime  present  in  the  100  grs.  taken.     This  mode  of  analysis  depends  upon  the  fact 
that  lime,  at  the  temperature  indicated,  decomposes  muriate  of  ammonia  and  becomes 
soluble,  but  any  carbonate  of  lime,  silicate  of  lime,  alumina,  or  other  inactive  impurity, 
remains  undissolved,  and  may  therefore  have  its  quantity  determined  by  the  balance. 
Foul  ^as-lime,  or  refuse,  is  somewhat  more  complex,  but  nevertheless  far  fi*om  diffi- 
cult in  its  analysis.     Having,  as  before,  selected  a  fair  sample,  let  200  grs.  be  weighed 
out;  and  placed  in  a  scoppered  bottle,  with  an  equal  weight  of  sal  ammoniac,  and  four 
ounces  of  water,  heated,  as  before,  to  about  80°  or  90° ;  shake  the  whole  well  together, 
and  keep  the  mixture  warm  for  twenty  minutes ;  then  filter  rapidly  into  a  stoppered 
retort,  and  wash  the  filter  with  two  ounces  of  hot  water,  which  are  to  be  added  to  the 
filtered  solution.      Next  distil  over  one-half  of  the  fluid  into  a  receiver  containing 
100  grs.  of  sulphate  of  copper,  dissolved  in  water,  and  set  the  fluid  remaining  in  the 
retort  aside  to  cooL     Collect  the  black  precipitate  now  contained  in  the  receiver  upon 
a  filter,  and  wash  it  well  with  hot  water,  then  dry  and  weigh  it :  it  is  the  sulphuret 
of  copper,  and  contains  one-third  of  its  weight  of  pure  sulphur.     The  fluid  in  the  retort 
must  now  be  mixed  with  an  excess  of  carbonate  of  soda,  and  the  white  precipitate  which 
ensues  well  washed,  dried,  and  then  weighed-     One  hundred  grains  of  this  precipitate, 
which  is  carbonate  of  lime,  indicate  56  grs.  of  pure  lime;  and  if  from  this  we  aeduct 
the  quantity  combined  with  sulphuretted  hydrogen,  as  given  by  the  sulphuret  of  copper, 
the  remainder  will  be  the  total  quantity  of  pure  lime  in  the  200  grs.  of  gas-lime  refus^ 
which  had  not  been  utilized  in  the  purifier.    Thus,  suppose  that  200  grs.  of  any  sample 
in  question  have  given  24  grs.  of  sulphuret  of  copper,  and  80  of  carbonate  of  lime,  then 
the  total  amount  of  lime  will  be  44*8  grs.,  from  which  14  grs.  must  be  deducted  for 
that  united  to  sulphuretted  hydrogen,  since  the  atom  of  sulphur  is  to  that  of  lime  as  16 
to  28,  and  24  grs.  of  sulphuret  of  copper  contain  8  grs.,  or  one-third  of  its  weight  of  copper, 
which  is  consequently  equal  to  14  grs.  of  pure  lime.     This  supposed  sample  has  there- 
fore given  30-8  grs.,  or  15-4  per  cent  of  free  lime.     Thus,  in  place  of  the  mere  rule  of 
thumb  system,  too  commonly  pursued  in  gas  works,  a  good  gas  engineer  will  control  the 
entire  produce  of  his  manufactory  by  determining,  first,  the  total  amount  of  sulphur  given 
off  in  a  gaseous  form  by  the  coal  he  uses ;  next  the  chemical  power  of  his  lime ;  and 
lastly,  whether  or  not  the  action  and  arrangement  of  the  purifying  apparatus  is  such  as 
to  insure  the  proper  saturation  of  the  lime  with  the  impure  constituents  of  the  coal  gas. 
Without  the  occasional  employment  of  analytical  processes,  similar  to  those  previously 
given,  it  is  altogether  impossible  to  conduct  gas-works  with  that  certainty  and  con- 
fidence essential  to  perfect  economy. 

3K2 


436 


COAL. 


COAL. 


437 


It  might  be  supposed  that  with  the  purification  of  coal  gas  the  chief  difficulties 
of  a  gas  engineer  ended    but  this  is  very  wide  of  the  truth;  for  upon  no  point  is 
there  greater  divereity  of  opinion,  and  more  discrepancy  in  result,  than  exists  regarding 
the  proper  mode  of  burning  gas  for  the  purposes  of  illumination  and  heating     As  re? 
gards  the  foi-mer  question,  it  seems  hitherto  to  have  been  impossible  of  solution   from 
the  fact  that  quantity  and  intensity  of  bght  have  been  confounded  together;  and  Der- 
jons  have  been  surprised  to  find  that  a  bright  white  light,  of  great  intensity  to  the  eve 
has,  nevertheless,  illuminated  a  given  space  worse  than  a  large  quantity  of  dulL  yellow' 
smoky-looking  light    Thus^  if  when  an  argand  oil  lamp  is^  burning  with  ^elthJi 
hancy  the  central  aperture  for  the  admission  of  air  be  closed,  the  flami  will  immediately 
?n!?n^tK^f  ?r  ^""^  'r?^'  ^^^  ^?  examining  the  walls  of  the  apartment,  it  will  be 
found  that  they  are  better  illuminated  than  with  the  more  brifiiant  light     In  the 
former  case,  many  of  the  particles  of  carbon  are  consumed  before  they  taklon  the  solid 
condition,  whereas  in  the  latter,  they  are  all  separated  from  the  hydrogen  of  the  oiL 
Sfvon-T.'-"'^"^^'  sohd  bodies  ere  they  inter  into  combustion/  But  as  the  quan- 
fhYfi    ^^r   "^  P^P^r^^^^^ed  to  the  number  of  solid  particles  heated,  and  its  intensity  to 
the  elevation  of  the  temperature  to  which  they  are  heated,  it  follows,  that  part  of  the 
carbon  IS  employed  m  producing  heat,  to  give  intensity  of  light  to  the  remainder,  in 
the  one  case  wlu  st  in  the  other,  the  whole  of  the  carbon  becoming  solid  reflects  a 
f/f K    T7\^U^  A^^*  ""^^T  Intensity.     For  the  ordinary  wants  of  society,  the  latter 
!f-a?!i-ff      ^^   '    :^,^?^^e<Jge  of  these  matters  enables  us  easily  enough  to  explain  the 
l^  A'T^^  in  lUummatmg  power  which  one  and  the  same  gas  displays  w^en  con- 
sumed  m  different  burners.    Thus,  a  thin  gas,  of  low  specific  gravity,  which  affords  an 
excellent  light  in  an  argand  burner,  will  scarcely  yield  any  light  at  all  with  a  fish-tail 
or  bat  8-wing;  and  a  rich  cannel  coal  gas,  well  adapted  to  either  of  the  latter  burners  re- 
quires mfimte  care  to  prevent  it  from  smoking  in  an  argand.    In  determining  the  relative 
mummatmg  powers  of  different  gases,  it  is  therefore  necessary  to  select  for  each  eas  that 
form  of  burner  best  suited  to  display  its  light-giving  properties,  and  not  continue  the 
present  Procrustean  system  of  cuttmg  down  the  power  of  the  gas  to  an  arbitrary 
standard  of  buraer;  the  only  result  of  which  has  been  a  series  of  assertions  and  con- 
tradictions too  disgraceful  for  further  notice.    In  photometrical  experiments,  a  sperma- 
ceti candle,  of  a  determined  size,  is  commonly  employed,  and,  in  a  rough  way  answers 
remarkably  well.     But  sperm,  like  wax  and  tallow,  gives  quantity  of  light  but  not  of 
an  mtensity  equal  to  gas.  as  may  be  seen  in  a  moment  by  contrasting  the  comparatively 
yellow  flame  of  the  one  with  the  brilliant  white  light  of  the  other.    They  are  therefore  like 
musical  instruments  tuned  to  a  different  pitch,  and  can  never  harmonize  with  each  other 
The  better  plan  would  be  to  select  olefiant  gas  as  a  photometrical  standard,  since  this 
compound  is  uniform  in  composition,  and  can  be  easily  prepared  at  a  few  minutes* 
notice.     It  possesses,  moreover,  the  advantage  of  being  consumed  in  similar  burners 
to  that  einployed  for  the  gas  to  be  tested,  and  is  under  the  influence  of  the  same  baro- 
metric and  thermometric  variations.    The  Bunsen  photometer,  as  modified  by  Mr.  A 
King,  of  liverpool,  is,  perhaps,  the  best  instrument  to  employ  in  experiments  on  com- 
parative illumination.     Regarding  the  ultimate  analysis  of  coal  gas  little  need  be  said, 
as  the  results  have  no  specific  value  or  meaning.     The  only  correct  mode  of  analysis  is 
by  passing  a  known  volume  of  the  gas  over  oxide  of  copper  in  a  tube  heated  red-hot^ 
and  collecting  first  the  moisture  by  chloride  of  calcium ;  secondly,  the  carbonic  acid  by 
hydrate  of  lime  or  solution  of  potash,  as  followed  in  ordinary  organic  analyses ;  andf, 
lastly,  receiving  the  incombustible  residue  over  water  in  the  pneumatic  receiver :  from 
winch  three  products,  the  quantity  of  hydrogen,  carbon,  and  nitrogen  may  be  deduced. 
The  ultimate  analyses  of  coal  gas,  as  also  the  estimation  of  its  value  from  the  condensa- 
tion of  what  is  termed  its  olefiant  gas,  whether  by  chlorine,  sulphuric  or  nitric  acid, 
are  processes  of  no  practical  value  to  the  public,  and  serve  only  to  mislead  the  ignorant 
From  the  vast  reduction  which  is  now  taking  place  in  the  prices  of  coal  gas,  its  calorific 
power  has  become  one  of  the  most  interesting  questions  of  the  day ;  and  when  the  waste 
of  fuel  consequent  upon  lighting  a  common  fire,  with  the  quantity  consumed  after  the 
fire  IS  no  longer  wanted,  are  carefully  inquired  into,  it  seems  very  clear,  that  for  at  least 
4  or  5  months  of  the  year  it  is  cheaper  to  cook  by  gas  in  London  than  by  coal,  at  the  ex- 
isting prices  of  these  articles.   An  apposite  illustration  of  the  correctness  of  this  assertion 
is  afforded  by  the  warm  bath  of  Mr.  Defries.  in  which  45  gallons  of  water  are  heated  from 
the  temperatures  of  60°  to  100°  Fahr.  by  30  cubic  feet  of  gas,  and  at  a  cost  of  only  three 
pence.   Now,  to  effect  this  at  all  by  coal  would  entail  an  expense  of  at  least  fourpence ;  but 
to  do  so  in  the  same  period  of  tune  (5  minutes),  would  certainly  entail  an  outlay  of  not 
leas  than  a  shilling.     Of  course,  where  the  operation  is  to  be  repeated,  or  go  on  continu- 
ously, a  different  result  would  ensue ;  but  for  extemporaneous  use,  coal  gas  will  always 
be  cheaper  than  coal.     But  even  this  surprising  economy  has  been  exceeded  by  a  very 
elegant  arrangment,  invented  by  Mr.  F.  I.  Evans,  of  Westminster,  in  which  a  coil  of 
iron  tubing  is  so  disposed,  as  to  present  an  immense  surface  to  the  heating  influence  of 
the  burnt  gas,  and  thus  absorb  the  whole  of  the  heat    In  this  way,  a  current  of  cold 


water  entering  at  one  end  of  the  tube  flows  out  of  the  other  continuously,  and  at  any 
required  temperature,  according  to  the  velocity  of  the  current,  and  the  quantity  of  gas 
consumed  in  a  given  time.     For  the  requirements  of  the  Humane  Society,  for  the  public 
hospitals  and  charities,  a  simple  apparatus  of  this  kind  must  find  a  ready  application, 
and  deserves  to  be  better  known.     According  to  direct  experiments,  made  with  great 
care,  Mr.  Evans  has  found  that  common  Newcastle  coal  gas,  of  sp.  gr.  -416,  has  an 
evaporative  value  equal  to  about  22  times  its  weighty  or,  in  other  words,  that  1  lb.  of 
such  gas  will  convert  theoretically,  22  lbs.  of  water  into  steam;  and  this  accords  very 
well   with  the   results  given  by  Defries  with  his  bath,  in  which  30  cubic  feet  of 
gas  are  stated  to  heat  46  gallons,  or  450  lbs.  of  water  at  50°.     This  is  equal  to  16  lb& 
similarly  heated  for  each  cubic  foot  of  gas,  weighing,  say  206  grains,  or  760  lbs.  of 
water  heated  one  degree  by  the  same  means.     This,  estimating  the  latent  heat  of 
steam  at  960,  gives  25  parts  of  water  boiled  off  for  every  one  part  of  gas  consumed, 
which  is  very  nearly  three  times  as  great  as  the  heating  power  of  good  Newcastle 
coaL      But  practical  experiments  were  wanting  to  show  the  real  amoxmt  of  water 
which  can  be  boiled  off  by  gas,  as  burnt  in  ordinary  burners  beneath  a  boiler.     This 
deficiency  has  been  supplied  by  Mr.  Evans,  to  whom  we  are  indebted  for  the  follow- 
ing tabular  statement :— -One  cubic  foot  of  gas,  weighing  about  205  grs.,  and  of  sp.  gr. 
•413,  boiled  off  four  tenths  of  a  pound  of  water,  or  13*6  times  its  weight  One  cubic  foot, 
weighing  about  290  grs.,  and  of  sp.  gr.  -564,  boiled  off  five  tenths  of  a  pound,  or  12  times 
its  weight    One  cubic  foot,  weighing  about  360  grs.,  and  of  sp.  gr.  -700,  boiled  off  seven- 
tenths  of  a  pound,  or  13*6  times  its  weight    Thus  showing  that  in  the  case  of  gas,  one- 
third  at  least  of  all  the  heat  evolved  passes  off  unabsorbed  by  the  boiler.    In  our 
comments  on  coal  we  had  occasion  to  remark  that  something  like  one-half  of  all 
the  fuel  consumed  under  steam  boilers  is  wasted ;  and  it  now  appears  that  fully  one- 
third  of  all  the  gas  employed  in  our  culinary  operations  must  be  thrown  awa^^,  and 
will  continue  to  be  so  until  the  hand  of  improvement  is  applied  in  the  proper  quarter. 
There  is,   unquestionably,  much   scope  for  ingenuity  in  devising  the  best  forms  of 
apparatus  for  burning  gas,  and  utilizing  its  waste  heat     A  very  elegant  little  machine, 
which  promises  to  elucidate  some  obscure  points  as  regards  the  purity  of  gas,  has 
lately  been  added  to  the  ordinary  testing  chemicals  of  a  gas  engineer.    This  con- 
sists of  a  bent  tube,  forming,  as  it  were,  the  horizontal  flue  of  a  furnace,  in  which  the 
products  of  combustion  arising  from  gas  may  be  condensed,  and  afterwards  examined 
with  reference  to  their  nature,     Mr.  A.  Wright  of  Westminster,  is  the  inventor  and 
maker  of  the  apparatus  in  question,  and  by  its  means  two  curious  facts  may  at  almost 
any  time  be  demonstrated.     One  of  these  is,  that  sulphuric  acid  is  an  invariable  pro- 
duct of  the  combustion  of  coal  gas ;  the  other,  that  very  frequently,  and  more  especially 
with  cannel  coal  gas,  a  substance  possessing  all  the  properties  of  aldehyde  makes  its 
appearance.    The  latter  seems  to  be  a  product  of  imperfect  combustion,  and  gives  rise 
to  that  peculiarly  offensive  odour  produced  wherever  large  quantities  of  coal  gas  are 
burnt  in  a  close  compartment     It  is  commonly  believed  by  chemists,  that  coal  gas 
contains  ammonia,  which  in  burning  is  converted  into  nitrous  or  nitric  acid ;  but  the  ap- 
paratus of  Mr.  Wright  demonstrates  at  once  the  fallacy  of  this  opinion,  by  proving  that 
whenever  gas  contaminated  with  ammonia  is  consumed,  the  ammonia  either  passes  off 
unchanged,  or  is  simply  decomposed  into  its  elements;  for  carbonate  of  ammonia,  and 
not  nitrate,  makes  its  appearance  in  the  condensed  products.     Before  quitting  the 
subject  of  coal  gas,  it  is  necessary  to  say  a  few  words  upon  the  composition  and  use  of 
what  is  called  ammoniacal  liquor.     This  fluid  condenses  in  the  hydraulic  main,  and 
flows  out  with  the  tar,  from  which  it  afterwards  separates  by  gravitation.     Its  specific 
gravity  varies,  as  also  does  its  composition ;  but  the  following  may  be  regarded  as  a 
fair  average:  in  one  gallon,  of  specific  gravity  of  1-017,  there  were  found  of  sesquicar- 
bonate  of  ammonia  5984  grains,  hydrosulphate  of  ammonia  420  grains,  muriate  of 
ammonia  985  grains,  with  a  trace  of  ferrocyanate  and  sulphocyanate  of  ammonia; 
consequently,  if  the  small  quantity  of  sulphuretted  hydrogen  existing  in  ammoniacal 
liquor  be  removed,  as  it  may  be  by  the  application  of  the  requisite  proportion  of 
carbonate  of  lead,  an  ammoniacal  solution  will  be  produced,  extremely  well  adapted 
for  many  useful   purposes   in   the   arts,  such  as  scouring  woollens,  flax,  and  other 
goods,  as  well  as  for  washing  in  general.     In  all  these  cases,  ammonia  is  greatly  to  be 
preferred  to  soda,  even  at  the  same  price ;  but  as  the  ammoniacal  liquor  of  many 
gas  works  is  actually  thrown  away,  and  under  no  circumstance  sells  for  more  than  a 
ferthing  a  gallon,  it  is  discreditable  to  our  industrial  economy  that  this  very  obvious 
application  of  ammoniacal  liquor  should  continue  to  be  neglected;  more  especially 
as  the  fluid,  even  aft«r  being  used  as  above  indicated,  is  still  an  excellent  fertilizing 
agent     In  the  Great  Exhibition,  there  were  but  few  illustrations  of  the  manufactures 
peculiar  to  gas;  a  circumstance  attributable  to  the  risk  of  permitting  the  necessary 
experiments  to  take  place,  by  which  alone  the  actual  value  of  any  improvement  in 
gas  apparatus  can  be  correctly  determined.     Hence,  in  the  Crystal  Palace,  merely 
articles  of  established  reputation  were  shown,  which,  haviog  been  long  before  the 


438 


COAL. 


COAL. 


439 


It 


l^!| 


; 


I 


public  eye,  by  no  means  represented  the  existing  condition  of  this  branch  of  manufac< 
ture.  On  this  account,  although  the  decision  of  the  executive  committee  to  exclude 
experimental  gas  apparatus  seems  somewhat  unfortunate,  yet,  when  the  great  value 
of  the  goods  shown  m  the  Exhibition  is  duly  considered,  there  can  be  but  two  opinions 
concerning  the  propriety  of  the  step.  The  various  samples  exhibited  were  neverthe- 
less extremely  good  of  their  kind,  both  in  the  British  and  Foreign  departments.  In 
clay  retorts,  the  best  specimen  was  in  Class  27.,  by  Cowan  &  Co.,  of  Blaydonburn, 
Newcastle-on-Tyne ;  and  the  next  in  quality  stood  in  the  Belgian  portion  of  the  Exhi- 
bition. M.  Pauvels,  of  Paris,  exhibited  a  very  good  retort  also ;  and  there  were  seve- 
ral satisfactory-looking  samples  from  other  quarters. 

Coal  Gas,  Composition  of.  From  the  most  recent  investigations  into  the  composi- 
tion of  coal  gas,  it  appears  extremely  doubtful  whether  any  gaseous  compound  exists 
in  it  to  which  the  name  olefiant  gas  can,  with  propriety,  be  accorded,  and  it  certainly 
seems  to  have  been  assumed  on  very  hasty  and  unfounaed  data,  that  to  the  presence  of 
olefiant  gas  the  illuminating  force  of  common  coal  gas  is  chiefly  due.  Without  pretend- 
ing to  deny  altogether  the  presence  of  the  olefiant  in  the  gas  of  our  streets,  it  is  never- 
theless susceptible  of  proof  that  the  quantity  which,  on  the  most  liberal  computation, 
can  be  allowed,  is  infinitely  small  and  insignificant,  and,  in  a  practical  sense,  warrants 
the  now  prevailing  opinion  that  there  is  really  none.  In  support  of  this,  it  can  be  showu 
that  if  common  coal  gas  be  made  to  traverse  very  slowly  a  great  length  of  tube  ex- 
posed to  the  refrigerating  eflFect  of  a  bath  of  ice  and  salt,  the  gas  will  issue  from  the  other 
end  of  the  tube  almost  entirely  deprived  of  its  illuminating  power ;  and  a  similar  result 
may  be  obtained  at  ordinary  temperatures  by  passing  the  gas  through  alcohol  and  other 
reagents.  In  the  case  of  alcohol,  the  efi"ect  is,  however,  very  instructive,  for  the  alcohol 
^ains  exactly  that  which  the  gas  loses  in  illuminating  power,  and,  after  the  experiment, 
it  is  found  to  burn  with  a  bright  white  flame,  and  to  become  milky  with  water.  Now, 
on  the  supposition  that  the  photogenic  power  of  coal  gas  was  due  to  olefiant,  notoe  of 
these  results  should  follow,  for  no  such  cold  would  liquefy  olefiant  gas,  nor  w^ould 
alcohol  absorb  it  in  any  great  degree.  Moreover,  all  attempts  to  obtain,  through  the 
agency  of  fuming  sulphuric  acid,  any  compound  like  sulpho-vinic  acid  have  utterly 
failed,  even  when  tried  upon  a  rather  large  scale.  Hence,  in  regarding  coal  gas,  it  is  theo- 
retically more  correct  to  consider  its  luminosity,  as  arising  from  the  presence  of  various 
volatile  hydrocarbons  or  naphthas,  rather  than  from  any  permanently  elastic  fluid  what- 
ever. This  view  of  the  case  has  latterly  become  very  prevalent,  and  is  now  leading  to 
the  most  important  improvements  in  the  manufacture  of  illuminating  gas.  It  has  long 
been  known  that  ordinary  bituminous  coals  will  yield  a  much  larger  volume  of  gas  than 
may,  with  propriety,  as  regards  the  photogenic  power  of  that  gas,  be  taken  away  from 
the  coaL  This  arises  from  the  circumstance,  that  the  first  portions  of  gas  are  much 
^richer  in  hydrocarbons  than  the  remainder  of  the  charge,  and  a  period  arrives  at  which 
the  gas,  though  still  great  in  quantity  and  eminently  combustible,  ceases  to  possess  any 
yalue  whatever  as  an  illuminating  agent.  Moreover,  it  is  known  that  the  mixed  gas 
obtained  by  decomposing  water  through  the  agency  of  carbon  at  a  red  heat  is  also  com- 
bustible, but  devoid  of  photogenic  power ;  and  it  is  owing  to  a  correct  appreciating  of 
the  circumstances  upon  which  the  value  of  common  coal  gas  depends,  that  both  these 
and  other  forms  of  combustible  gas  have  lately  been  rendered  as  permanently  luminous 
and  well-adapted  for  the  production  of  light  as  the  best  kinds  of  common  coal  gas. 
Having  once  clearly  comprehended  the  cause  of  luminosity  in  ordinary  gas,  but  few 
steps  are  required  to  perceive  that  the  latter  portion  of  a  charge  of  coal,  when  distilling 
in  a  retort,  needs  but  a  part  of  the  surplus  hydrocarbons  of  the  first  portion  to  render  it 
equally  valuable,  and  we  are  insensibly  drawn  to  the  means  of  effecting  the  desired  end. 
Thus,  if  the  latter  portions  of  the  charge  be  stored  away  separately,  and  passed  in  regu- 
lar quantities  over  coal  which  is  undergoing  the  primary  action  of  destructive  distilla* 
tion,  it  is  clear  that  such  gas  will  become  charged  with  the  hydrocarbons  of  that  primary 
distillation,  and  thus,  in  all  respects,  resemble  the  first  part  of  the  charge,  or,  m  other 
words,  be  made  equal  to  the  best  gas;  at  the  same  time  the  amount  of  labour  and  ex- 

Eense  incurred  in  condensing  out  these  surplus  hydrocarbons  must  be  much  diminished 
y  the  presence  of  an  amount  of  gas  capable  of  retaining  them  permanently  in  solution 
at  ordinary  temperatures.  Not  only,  therefore,  is  it  possible  to  procure  in  this  way  a 
much  larger  quantity  of  gas  of  an  average  illuminating  power  from  a  given  weight  of 
coal,  but  the  expense  of  this  production  is  decreased  by  the  diminished  condensation 
needed  for  the  whole,  as  compared  with  that  required  for  a  part  of  the  gas  under  the  old 
system.  But  there  is  a  still  greater  advantage  than  these,  and  one  scarcely  to  have  been 
expected.  These  poor  gases  consist  chiefly  of  hydrogen  gas,  and  it  has  been  discovered 
that  this  gas  possesses  the  remarkable  property  of  preventing  the  decomposition  of 
every  form  of  hydrocarbon  at  a  red  heat.  The  consequence,  therefore,  of  passing  such 
gas  over  coals,  m  its  primary  state  of  distillation,  is  to  prevent  the  decomposition  of  the 
various  naphthas  by  the  heat  employed,  and  which,  without  the  presence  of  hydrogen, 
would  be  resolved  into  solid  carbon  and  light  carburetted  hydrogen,  the  former  of  which 


remaining  in  the  retort  impairs  the  utility  of  that  vessel,  whilst  the  illuminating 
power  of  the  gas  produced  is  greatly  diminished  by  the  loss  of  solid  matter.  Now 
it  has  been  stated  that  to  these  naphthas  the  luminosity  of  gas  is  to  be  attributed,  and 
therefore  their  preservation  in  the  way  described,  by  the  action  of  hydrogen,  would  of 
itself  be  an  immense  step  in  advance  of  our  former  practice ;  but  when  to  this  is  added 
the  fact  that,  with  a  vastly  increased  preservation  of  hydrocarbon,  there  is  also  a  vastly 
increased  production  of  combustible  gas  to  render  that  hydrocarbon  available  for 
public  use,  the  real  merit  of  the  new  discoveries  in  gas-making  must  strike  even  the 
most  thoughtless  observer.  Of  course,  the  same  argument  which  applies  to  the  use  of 
the  residuary  gas  from  a  charge  of  coal,  is  equally  fitted  to  illustrate  the  beneficial  ope- 
ration of  the  gases  evolved  by  decomposing  water  with  red  hot  carbon.  In  this  latter 
instance,  however,  an  important  fact  presents  itself^  for  unless  the  whole  of  the  surplus 
watery  vapour  has  been  removed  or  condensed  from  this  water  gas,  the  hydrocarbons 
arising  from  the  incipient  distillation  of  the  coal  are  destroyed,  and,  therefore,  the  ob- 
ject sought  to  be  gained  is  lost.  This  accounts  perfectly  for  the  innumerable  failures 
which  have  taken  place  in  attempting  to  employ  steam  and  water  gas  for  the  purpose 
of  illumination ;  nor,  until  this  subject  was  investigated  by  Mr.  T.  G.  Barlow,  does  any 
one  appear  to  have  formed  a  correct  opinion  of  the  cause  of  such  invariable  want  of 
success.  Mr.  Barlow,  however,  not  only  discovered  the  peculiar  preservative  power  of 
hydrogen,  but  also  the  no  less  remarkably  destructive  action  of  steam,  and  hence,  by 
merely  condensing  this  latter,  he  has  been  enabled  to  employ  water  gas  with  a  suc- 
cess which  bids  fair  to  prove  a  very  profitable  manufacturing  speculation,  and  for  the 
details  of  which  he  has  secured  her  Majesty's  letters  patent  in  conjunction  with  Mr. 
Gore.  For  the  application  of  the  residuary  gas  from  common  coal  to  the  preservation 
of  the  hydrocarbons  arising  from  fixed  oils  and  fats  during  distillation,  and  for  the 
production  from  coals,  lignite,  tar,  Ac,  of  a  larger  amount  of  illuminating  gas  than 
can  be  obtained  by  the  ordinary  process,  the  public  is  indebted  to  Messrs.  G.  Lowe 
and  F.  L  Evans,  both  well  known  as  engineers  in  the  service  of  the  Chartered  Gas 
Company.  That  these  improvements  will,  in  some  measure,  revolutionise  the  manu- 
facture of  gas  seems  pretty  obvious. 

To  determine  with  any  degree  of  precision  the  value  of  a  gas  as  an  illuminating 
agent  is  really  a  very  difficuft,  though  seemingly  a  very  simple  affair.  The  most  ge- 
neral method  is  by  the  instrument  called  the  Bunsen  photometer.  The  indications 
of  this  instrument  (at  best  but  imperfect)  have  been  so  largely  improved  by  the 
ingenious  modifications  made  in  its  use  by  Mr.  Alfred  King,  of  Liverpool,  that  it  has 
come  to  occupy  a  position  in  the  public  confidence,  to  which  in  its  original  condition  it 
had  not  the  slightest  title.  The  great  difiiculty  to  overcome  was  the  securing  of  one 
uniform  standard  of  illumination,  without  which,  as  a  matter  of  course,  the  indications  of 
the  photometer  were  utterly  valueless.  This  indispensable  condition  has  been  in  a  great 
meusure  arrived  at  by  Mr.  King,  who  employs  a  spermaceti  candle,  and  ascertains  the 
amount  of  spermaceti  actually  consumed  during  the  experiment,  and  then  reduces  this 
to  one  uniform  rate  of  120  grains  of  spermaceti  burnt  per  hour  as  con- 
■^  trasted  with  an  hour's  consumption  of  tlie  gas  to  be  tried  at  the  rate  of 
five  feet  per  hour,  or  in  a  series  of  ratios,  from  2  to  5  feet  per  hour ;  there 
are,  however,  many  disturbing  causes  in  the  burning  both  of  the  candle 
and  of  the  gas,  and  a  very  serious  one  results  from  the  fact  that  the  shape 
of  the  flame  of  the  gas  materially  affects  its  photogenic  meter,  thus  the 
flat  side  of  a  bat's-wing  burner  will  give  almost  one-third  more  light 
than  the  edge  of  the  same  burner,  though  the  rate  of  consumption  be 
unaltered. 

It  is  necessary,  therefore,  to  adopt  some  other  means  of  determining 
the  value  of  a  gas  than  by  photometry,  and  it  would  appear  that 
this  may  be  effected  by  the  agency  of  bromine.  This  substance 
possesses  in  a  singular  degree  the  power  of  removing  from  coal  gas  the 
whole  of  the  vapours  upon  which  its  luminosity  depends,  and  if  these 
vapours  were  uniform  in  composition,  all  that  need  be  done  would  be  to 
determine  their  volume  per  cent  But  this  is  quite  useless,  for  the  vapours 
differ  in  themselves  to  an  incredible  extent,  and  therefore  it  is  not  only 
the  volume,  but  the  specific  gravity  of  these  vapours  also,  which  must  be 
obtained,  or  in  other  words,  their  total  weight,  for  this  weight  repre^ 
sents  the  value  of  the  gas.  Now  if  we  take  a  tube  bent,  closed  at  one  en^ 
and  graduated,  as  shown  in  the  following  figure,  we  possess  at  once  an 
instrument  for  determining  the  value  of  a  gas  by  volume. 

This  tube  must  be  filled  in  the  first  place  with  water,  and  so  much  of 
the  gas  passed  up  into  it  as  will  occupy  the  graduated  portion,  when  the 
residuary  water  will  act  as  a  valve.     Having  placed  the  whole  for  a  few 
minutes  in  a  cylindrical  vessel  containing  water,  so  as  to  secure  a  imiforxn 


SO 


fiO 


70 


60 


90 


40 


30      i 


SO 


440 


COAL. 


'  f 


temperature,  the  tube  must  be  raised  to  the  water  level,  and  the  exact  quantitj  of 
gas  recorded  When  this  has  been  done,  a  few  drops  of  bromine,  in  all  about  the 
size  of  a  pea,  are  to  be  dropped  through  the  water  in  the  tube,  and  a  stopper  or  cork 
applied ;  the  whole  must  then  be  well  agitated,  until  the  gas  becomes  tinged  with  the 
rea  hue  of  the  bromine,  after  which  the  stopper  must  be  removed  under  water,  and  a 
few  drops  of  a  strong  solution  of  potash  being  added  the  stopper  is  to  be  replaced,  and 
the  whole  again  agitated  until  the  bromine  tint  of  the  gas  has  disappeared,  when  the 
stopper  must  be  again  withdrawn  under  water,  and  the  tube  placed  as  at  first  in  a 
vessel  of  water  to  regain  its  original  temperature,  when  the  water-level  must  be 
once  more  made,  and  the  amount  of  absorption  read  off  and  recorded-  This  operation 
does  not  last  more  than  10  or  15  minutes,  the  barometer  need  not  therefore  be  con- 
sulted. Precisely  similar  to  this,  but  on  a  larger  scale,  is  the  first  part  of  the  opt-a- 
tion  for  determining  the  weight  of  the  condensed  portion.  In  this  case  a  vessel  shaped 
as  below  is  necessary. 

A  This,  as  is  evident,  differs  very  slightly  from  the  tube,  the 

bottom  being  provided  with  the  same  water-joint  contrivance 
for  the  introduction  of  the  bromine,  whilst  the  stopper  is 
pierced  by  a  hole,  in  which  a  stop-cock  is  very  carefully  fixed, 
so  that  after  the  action  of  the  bromine  and  caustic  potash,  the 
gas  may  be  removed  by  an  exhausted  flask  so  that  its  specific 
gravity  can  be  readily  determined.  Before  doing  this,  it  is 
however  advisable  to  wash  the  gas  two  or  three  times  with  cold 
water,  which  is  easily  done  if  we  introduce  the  bottle  into  a 
vessel  of  warm  water  so  as  to  expand  the  gas,  and  thus  expel 
the  fluid  through  the  water-joint  tube,  which  being  effected,  we 
have  only  to  close  this  opening  and  immerse  the  bottle  in  cold 
water,  When,  by  withdrawing  the  stopper  joint,  cold  water  will 
rush  in,  and  this  may  be  repeated  at  [Measure,  the  object  being 
to  wash  the  residuary  or  incondensable  gas  thoroughly;  this 
operation  requires  but  a  short  time,  and  if  we  have  taken  before- 
hand the  specific  gravity  of  the  original  gas,  the  amount  of  its 
condensation,  and  now  know  the  specific  gravity  of  the  incondensable  portion,  it  is  clear 
that  we  possess  the  means  of  knowing  the  exact  weight  of  that  which  has  been  condensed. 
Thus,  a  cannel  coal  gas  at  Westminster  was  analyzed  in  this  way,  its  illuminating  power 
by  the  photometer  being  20  candles  per  5  feet.  This  gas  had  a  specific  gravity  of 
•48500,  and  a  condensation  of  9  per  cent,  wiiilst  the  specific  gravity  of  the  uncondensed 
portion  was  -336.  But  if  100  weigh  -33600,  then  91,  the  amount  of  uncondensed, 
must  weigh  -30576,  and  this  deducted  from  -48500,  leaves  -19924  for  the  condensed 
gas,  which,  as  we  have  seen,  is  equal  to  9-5  per  cent,  and  bringing  this  to  the  uniform 
standard  of  100  measures,  we  have  2-09  for  the  specific  gravity  of  tliis  condensed  vapour ; 
and  if  this  specific  gravity  be  multiplied  by  the  amount  of  condensation,  we  shall  have 
the  true  value  of  the  gas  in  numbers,  which,  by  a  singular  coincidence,  run  very  close 
with  the  indications  of  the  photometer  as  chosen  by  Mr.  King,  that  is  to  say,  the  num- 
ber of  spermaceti  candles  burning  120  grains  per  hour,  which  the  gas  is  equal  to  when 
consumed  at  the  rate  of  5  feet  per  hour.  In  this  instance  that  number,  it  will  be  re- 
membered, was  20,  and  2-09,  the  specific  gravity  of  the  condensed  gas,  multiplied  by 
9-5,  its  per  centage  absorption  by  bromine,  gives  20*855,  a  very  close  approximation. 
A  vast  number  of  experiments  have  been  made,  all  of  which  are  equally  conclusive  as 
to  the  value  of  these  indicators. 

Coals  {heating  powers  of).  An  accurate,  systematic,  and  intelligible  report  upon 
the  calorific  properties  of  coal  has  long  been  needed  by  the  manufacturing  and  mercan- 
tile interests  of  this  country.  In  addition  to  the  vast  importance  of  such  an  inquiry,  it 
would  be  perhaps  impossible  to  point  out  a  subject  on  which  less  difference  of  opinion 
exists  as  to  the  extent  and  nature  of  the  information  wanted  than  the  one  before  us. 
Science,  properly  speaking,  has  little  or  nothing  to  do  with  the  question ;  the  object  in 
view  is  purely  and  exclusively  practical,  and  is  meant  for  the  guidance  of  practical  men 
and  for  practical  purposes.  Theory,  above  all  things,  should  be  carefully  avoided  in 
such  investigations ;  and  supremely  indifferent  about  the  assistance  of  any  eminent 
chemist  on  such  an  occasion,  we  should,  nevertheless,  insist  strongly  upon  the  necessity 
of  providing  a  good  stoker.  Mr.  Hume,  M.  P.,  however  thought  otherwise ;  and  to  him 
the  country  is  indebted  for  the  first  report  upon  the  coals  destined  for  the  steam  navy.  Of 
this  report  we  will  venture  to  say  at  once  that  a  more  garbled,  more  inaccurate,  and  less 
impartial  job  was  never  exhibited — nay,  not  even  in  the  House  of  Commons.  To 
begin  at  the  beginning  of  this  disgraceful  affair,  we  will  merely  remark  that  Mr.  Hume 
(whose  honesty  and  integrity  are  beyond  suspicion)  directed  the  attention  of  the  Lords 
of  the  Admiralty  to  a  subject  which,  if  these  Lords  attended  to  anything  but  their  sala- 
ries^ must  have  occupied  their  attention  years  ago.    Mr.  Hume,  after  referring  their 


C50AL. 


441 


lordships  to  an  American  report,  with  experiments,  on  the  evaporative  value  of  coals, 

"  They  have  decided  by  direct  and  practical  tests  the  comparative  usefulness  of 
American  and  English  coals,  as  well  as  the  relative  value  of  the  former  in  their  nume- 
rous varieties ;  and  I  submit  to  your  lordships  that  a  similar  inquiry  should  be  instituted 
into  the  comparative  usefulness  of  English,  Scotch,  and  Irish  coals,  with  the  view  of  as- 
certaining the  best  for  the  naval  steamers  of  this  country.  I  may  be  allowed  to  point 
out  to  your  lordships  that  there  is  a  public  establishment  in  Craig's-court  perfectly 
qualified  to  apply  the  requisite  direct  and  positive  tests  to  the  coals  without  delay ;  and 
to  that  establishment  may  be  added  one  chemist  of  eminence  to  assist  in  what  is  an 
object  of  great  national  importance." 

Upon  this  the  Admiralty  applied  to  Sir  H.  de  la  Beche,  who,  after  the  usual  preh- 
minary  remarks,  observes : — 

"  As  the  funds  of  the  Musemn  of  Economic  Geology  are,  unaided,  inadequate  to  an 
investigation  of  this  order,  I  would  suggest  that  the  Admiralty  be  requested  to  furnish 
aid  to  the  amount  of  600/.  for  the  remainder  of  the  year  ending  the  81st  of  March,  1846. 
With  this  aid  I  have  little  doubt  that  we  should  be  enabled  to  accomplish  much  this 
year  which  may  be  of  value,  and  have  organized  a  system  of  inquiry  alike  effective,  and, 
viewing  its  national  importance,  which  can  be  carried  out  at  comparatively  small  cost  to 

the  public." 

We  must  content  ourselves  by  guessing  at  the  meaning  of  the  last  paragraj)h,  and,  as 
far  as  this  can  be  done  with  safety,  we  may  conclude  that,  in  the  opinion  of  Sir  H.  del* 
Beche,  the  funds  of  the  Economic,  plus  600/.,  would  answer  the  object  in  view,  to  wit, 
the  obtaining  a  practical  report  upon  the  evaporative  power  of  English,  Scotch,  and 
Irish  coals.  If  anything  else  is  meant,  why  is  600/.  named  ?  The  question  is  very  fairly 
put  by  Lord  Lincoln,  who,  in  reference  to  the  establishment  in  Craig's-court,  asks,  in 
plain  English,  "  What  is  the  course  you  would  recommend  for  making  it  effective  for 
the  purposes  to  which  such  an  inquiry  would  be  obviously  directed  ?"  Sir  H.  de  la 
Beche  in  answer  mentions  600/.  in  addition  to  the  funds  of  the  Museum  of  Economic 
Geology;  yet  something  more  appears  to  have  been  given  by  the  following  " memo- 
randum" :-r-  •  a    .      1     /.  •       1 

"  The  Admiralty  having  acceded  to  the  recommendation  made  m  the  foregoing  letter, 
and  subsequently  also  supplied  additional  funds  for  the  investigation,  the  latter  was  com- 
menced as  soon  as  the  needful  apparatus  was  erected  and  proper  assistance  procured, 
which  could  not  be  accomplished  until  March,  1846." 

Now,  what  is  the  meaning  of  the  additional  funds  supplied  for  the  investigation? 
Were  the  funds  of  the  Economic,  plus  600/.,  spent  on  apparatus  alone  ?  And  was  it  to 
the  mere  erection  of  this  apparatus  that  Sir  H.  de  la  Beche  alluded  when,  in  1845,  he 
wrote,  "  With  this  aid  I  have  little  doubt  that  we  should  be  enabled  to  accomplish  mvu;h 

this  year,"  <tc.  ? 

There  is  a  mystery  about  the  very  commencement  of  that  business.  Seldom  do  we  find 
Government  officials  ready  to  comply  with  the  prayer  of  a  petition  which  has  merely 
public  utility  to  recommend  it ;  but  Mr.  Hume  has  nothing  to  complain  of  on  that 
score  in  the  present  instance,  for  in  addition  to  the  Craig's-court  establishment  he  soli- 
cited but  one  chemist,  when  lo  1  the  investigation  falls  into  the  hands  of  Dr.  Lyon 
Playfair,  Mr.  Wilson,  Mr.  J.  Arthur  Phillips,  Mr.  Kingsbury,  Mr.  Wrightson,  Mr. 
Galloway,  Mr.  Hoy,  and  William  Hutchinson,  all  and  each  endowed  with  qualifi- 
cations of  a  peculiar  and  important  character  bearing  upon  the  investigation  in  hand, 
and  tending  of  course  to  render  the  report  superlatively  correct,  useful,  impartial,  Ac,  Ac 
There  is  an  old  axiom  regarding  broth  made  by  a  multiplicity  of  cooks,  but  perhaps  it 
does  not  apply  to  parliamentary  reports  and  chemists. 

The  mystery  does  not,  however,  end  here.  Mr.  Hume  had  requested  that  the  inquiry 
should  be  made  upon  EngHsh,  Scotch,  and  Irish  coals.  Now,  the  following  is  the  list 
of  coals  operated  on : — 

NAMES  OF  COALS   EMPLOYED   IN   THE   EXPERIMENTS. 


Welsh — 

Graigola, 

Anthracite,  Jones  and  Co. 
Old  Castle  Fiery  Vein, 
Ward's  Fiery  V  ein, 

Binea, 

Llangenneck, 

Pontrepoth, 

Pontrefellin, 

Duffryn, 

Mynydd  Newydd, 

Vol  L  8  L 


Three  Quarter  Rock  Vein, 

Cwm  Frood  Rock  Vein, 

Cwm  Nanty  Gros, 

Resolven, 

Pontypool, 

Bedwas, 

Ebbw  Vale, 

Perth  Mawr, 

ColeshilL 


1 1 

i-'.i 


442 


1 1  • .  I 


^■l 


COAL. 


Scotch — 

Dalkeith  Jewel  Seam, 
Dalkeith  Coronation  Seam 
Wallsend  Elgin. 

English — 

Broomhill, 

Irish — 


Fordel  Splint; 
Grangemouth. 


Lydney  (Forest  of  Dean). 
Slievardagh  Irish  Anthracite. 


Prom  which  it  appears  that  the  inquiry  has  been  made  almost  exclusively  upon  Welsh 
coalfl^  for,  out  of  twenty-seven  samples  of  coal  examined, 

19  were  Welsh, 

5     „     Scotch, 

2      „     English, 

1  was  Irish. 
One  of  two  things  is  very  plainly  exhibited  by  this  table ;  either  Wales  is,  above  all 
other  places  in  the  world,  blessed  with  coals  "  suited  to  the  steam  navy,"  or  a  most 
unjust  and  uncalled-for  selection  has  been  made  for  private  purposes.  It  is  vain  to  talk 
of  a  next  report ;  it  will  require  years  to  complete  another  report,  even  if  such  another 
disgraceful  exhibition  of  partiality  was  attempted ;  and  meanwhile  our  steam  navy  must 
be  supplied  with  the  euphonious  productions  of  Wales,  to  the  exclusion  of  the  vast 
coalfields  of  Newcastle.  Of  the  two  samples  of  English  coal  examined  I  am  practically 
acquainted  with  but  one,  for  of  the  Lydnev  coal  I  know  nothing;  as  regards  the 
Broomhill  coal,  however,  I  can  safely  assert  that  its  only  recommendation  consists  in 
its  belonging  to  Earl  Grey,  for  at  Newcastle  it  is  regarded  as  an  unimportant  second- 
rate  coal,  the  very  name  of  which  has  not  yet  found  its  way  into  the  London  market.  It 
is  far  inferior  for  steam  purposes  to  the  whole  of  the  undermentioned  coals,  many  of 
which  are,  in  fact,  the  best  steam  coals  for  sea-going  vessels  in  the  kingdom : 

West  Hartley, 


Carr's  Hartley, 
Hasting's  Hartley, 
Hedley's  Hartley, 
Newcastle  Hartley, 
Percy  North  Hartley, 
Richardson's  Hartley, 


Bate's  West  Hartley, 
Buddie's  West  Hartley, 
Davidson's  West  Hartley, 
Nelson's  West  Hartley. 


Why  these  and  many  others  have  been  passed  over  so  unceremoniously  to  make  room 
for  the  wholesale  introduction  of  the  Welsh  coal  remains  to  be  explained ;  we  will  now 
however,  examine  the  report  itself. 

The  first  circumstance  which  attracts  attention  in  this  report  is  the  appearance  of 
certain  very  simple  equations,  which,  although  well  enough  adapted  for  a  boy  just 
commencing  algebra,  are  singularly  out  of  place  here,  since  those  who  understand  such 
things  generally  prefer  to  make  their  own  equations ;  and  those  who  do  not  are  but  little 
likely  to  benefit  by  such  a  display  of  learning. 

A  curious  attempt  is  made  at  page  13.  to  prove  that  the  evaporative  value  of  a 
bituminous  coal  is  expressed  by  the  evaporative  value  of  its  coke : — 

**  It  is  easy,"  says  the  report,  "  from  analysis  to  examine  whether  the  duty  performed 
by  the  coal  is  to  be  attributed  to  its  fixed  ingredients  or  coke,  by  estimating  the  work 
which  the  latter  is  capable  of  performing.  This  maybe  done  by  subtracting  the  ashes 
in  the  coal  from  its  amount  of  coke,  and  estimating  the  remainder  as  carbon ;  this 
carbon  multiplied  by  its  heating  power,  13268,  and  divided  by  966-7,  or  the  latent  heat 
of  steam,  indicates  the  number  of  pounds  of  water  which  the  coke  by  itself  could 
evaporate  without  the  aid  of  the  combustible  ingredients  of  the  coal.  These  results  are 
placed  in  column  3.  of  Table  6.  (see  next  page),  in  juxtaposition  with  the  actual  work 
done  by  the  coal,  and  it  will  be  seen  that,  notwithstanding  several  striking  exceptions, 
which  might  have  been  expected,  they  on  the  whole  show  that  the  work  capable  of 
being  performed  by  the  coke  alone  is  actually  greater  than  that  obtained  by  experi- 
ments with  the  original  coal." 

Now,  if  this  table  proves  anything,  it  proves  the  very  reverse  of  the  position  attempted 
to  be  established,  unless  theory  is  presumed  to  be  equal  to  practice,  which  it  certainly 
is  not,  or  why  the  necessity  of  spending  upwards  of  600/.  in  practical  experiments? 
But  theory  may  be  justly  compared  with  theory,  and  then  the  table,  so  far  from  proving 
"  that  the  evaporative  value  of  a  bituminous  coal  is  expressed  by  the  evaporative  value 
of  its  coke,"  clearly  proves  that  the  evaporative  power  of  a  bituminous  coal  is  an 
immense  deal  greater  than  that  of  its  coke;  indeed  almost  double;  and  that  the  volatile 
ingredients  of  coal  evolve  in  burning  relatively  a  much  greater  proportion  of  heat  than 


k5.T 


te 


jjunw 


COAL. 


443 


the  fixed  constituents ;  this  is,  indeed,  precisely  what  might  have  been  expected  from 
the  well-known  caloric  power  of  hydrogen,  which  is  three  times  greater  than  that 


EXTBACT   FROM    TABLE    6.,   SHOWING    THE   ACTUAL   DUTY 

AND   THAT 

WHICH  IS 

THEORETICALLY  POSSIBLE  OF  THE  COALS  EXAMINED. 

Aetnal  N  amber  of 

Mnmbcr  of  Iba. 

Total  JTnmber 

Amennt  of 

Um.  of  W«l«r 

ofWltfr 

eribt.ofW«ur 

Anoant  of 

KiUpbate  of 

ceovertMl 

couTcrted  into 

coDTertible 

Ammonia 

Ammonia 

Xamr  t  LocaUty  of  Co«L 

into  Hlnm 

t^teaiu  bjr  Utc 

iotoBteam 

corre*poodiu( 

eorreapuidiaf 

by  lib.  of 

Uoke  left  br 

by  lib.  of 

to  the  Mitro^en 

to  the  Mitragcn 

UoaL 

UieCoaL 

tbctioaL 

contained  ia 
theCoaL 

coutaiued  in 
the  CoaL 

Praetk^ 

TbeoretiemI . 

Theoretical. 

Graigt>la       .... 
Anthracite,  Jones  and  Co.  • 

9-35 

11-301 

13  563 

0  497 

1932 

9-46 

12-554 

14-593 

0225 

0-990 

Old  Castle  Fiery  Vein 
Ward's  Fiery  Vein      - 
Binea  -        •        -        -        . 

8-94 

10-601 

14-936 

1590 

6-175 

9-40 

. 

14-614 

1-238 

4 -SOS 

9-94 

11-560 

15-093 

1586 

6-741 

Llaogenneck        •        •        • 

886 

10-599 

14-260 

1299 

5-044 

Pontrepoth  -        -        -        - 

8-72 

10-873 

14-838 

0-218 

0-848 

Pontrefeilin          ... 

636 

10-841 

13787 

a  trace 

— 

Powell's  Duffryn 

10149 

11134 

15092 

1-76 

6-835 

Mynydd  Newydd 

Three  Quarter  Rock  Vein  - 

9-52 

9-831 

14-904 

1-808 

7-340 

684 

7-081 

13-106 

1299 

5-044 

Cwm  Frood  Rock  Vein 

8-70 

8-628 

14-788 

1-347 

5232 

Cwm  Nauty  Gros 
Resulven               ... 

8-42 

8-243 

13-932 

1-919 

7-448 

9-53 

10-234 

13-971 

1-675 

6-505 

Ponlypool    .... 
Bedwas                 ... 

7-47 

6-144 

14-295 

1639 

6-364 

9-79 

8-897 

14-841 

1-748 

6-768 

EbbwVale          •       -       - 

10*21 

10-441 

15  635 

2-622 

10  182 

Forth  Mawr  Rock  Vein 

7-53 

6-647 

12-811 

1-554 

6-033 

Coleshill      .... 

80 

6-468 

12-799 

1.785 

6930 

Dalkeith  Jewel  Seam 

708 

6-239 

12-313 

1-214 

0  471 

Dalkeith  Coronation    - 

7-71 

6-924 

12-772 

a  trace 

— 

Wallsend  Elgin  - 

8-46 

6  560 

13-422 

1-712 

6-647 

Fordel  Splint       ... 

7-56 

6.560 

13817 

1-372 

5327 

Grangemouth       ... 

7-40 

7-292 

13-692 

1-639 

6-364 

Broomhill    .... 

7-30 

7-711 

14663 

2-234 

8674 

Park  End  Lydney 
Slievardagh          ... 

8  52 

6-567 

13-257 

1-477 

9617 

9-85 

10-895 

12-482 

0-279 

1-084 

of  carbon.  There  is,  however,  clearly  a  design  throughout  this  report  to  extol  the 
anthracite  coals  at  the  expense  of  the  bituminous ;  and,  if  Messrs.  de  la  Beche  and  Ca 
could  succeed  in  establishing  the  fact  that  the  heating  power  of  coal  is  due  solely  or 
even  principally  to  its  relative  amount  of  carbon,  it  follows  that  "Welsh  coal  must  rise 
in  the  market,  for  the  greater  part  of  the  coal  from  that  district  is  of  the  anthracite 
kind,  none  of  which  is  worked  in  the  north  of  England.  To  prove  the  absurdity,  how- 
ever, of  the  above  attempt,  I  will  quote  two  or  three  cases  from  Table  No.  6. : — 


Theoretical 

Name  of  the  Coal. 

Weight  of  Water 

Excess 

Evaporated 

due  to  Volatile 

Coke. 

by 
Coal. 

Ingredients. 

"Welsh — 

Graigola  -        -        -        - 

11-301 

13-563 

2-262 1 
4-335 
5-01 Z 

Old  Castle  Fiery  Vein      - 
Mynydd  Newydd     - 
Scotch  — 

10-601 
9-831 

14-936 
14-904 

The  thing 
speaks 

Dalkeith  Jewel  Seam 

6-239 

12-313 

6-074 

for  itself 

English  — 

Broomhill 

1-111 

14-863 

'7-162J 

After  theoretically  demonstrating  that  "  the  evaporative  value  of  a  bituminous  coal 
is  expressed  by  the  evaporative  value  of  its  coke,  the  heat  of  combustion  of  its  volatile 
products  provmg  in  practice  little  more  than  that  necessary  to  volatilize  them,"  we  are 
suddenly  greeted  with  the  following  paragraph : — 

"  The  whole  system  of  manufacturing  coke  is  at  present  very  imperfect  Besides 
losing  the  volatile  combustible  substances,  which,  under  new  adjustments,  might  be 
made  of  much  value,  an  immense  quantity  of  ammonia  is  lost  by  being  thrown  into  the 
atmosphere.  Ammonia  and  its  salts  are  daily  becoming  more  valuable  to  agriculture, 
and  it  is  their  comparative  high  price  alone  which  prevents  their  universal  use  to 
all  kinds  of  cereal  cultivations.  By  a  construction  of  the  most  simple  kind  the  coke- 
ovens  now  in  use  might  be  made  to  economize  much  of  the  nitrogen,  which  invariably 
escapes  in  the  form  of  ammonia.     As  an  inducement  to  this  economy,  we  have  ap> 

3L2 


k  ' 


"^' 

h)! 


k  i' 


444 


COAL. 


pended  to  Table  6.  two  columns  showing  the  quantity  of  ammonia  and  its  corre» 
ponding  quantity  of  commercial  sulphate  which  each  100  lbs.  of  the  respective  coals 
may  be  made  to  produce.  When  it  is  remembered  that  the  price  of  sulphate  of 
ammonia  is  about  13/.  per  ton,  or  that  100  tons  (of  coal,  we  suppose)  in  coking  is 
(are  ?)  capable  of  producing  on  an  average  about  six  tons  of  this  salt^  its  neglect  is 
highly  reprehensible." 

Nothing  has  tended  half  so  much  to  retard  the  cultivation  of  chemistiy  by  our 
practical  manufacturers  as  the  kind  of  statements  of  which  the  above  is  a  sample. 
Written  by  individuals  wholly  ignorant  of  the  subject  of  which  they  treat,  these 
assertions  serve  only  to  amuse  practical  men,  and  to  demonstrate  the  stupendous  folly 
and  assurance  of  their  authors.  Imperfection  is  an  attribute  of  humanity,  but  that 
the  present  system  of  making  coke  is  very  imperfect  remains  to  be  proved. 

The  Tolatile  combustible  matter  of  the  coal  is  not  lost;  on  the  contrary,  it  i« 
employed  as  a  means  of  converting  the  cinder  of  the  coal  into  coke,  and  that,  too,  by 
the  heat  which  it  evolves  in  burning ;  and  if  that  heat  was  so  inconsiderable  as  the 
report  would  lead  us  to  suppose,  mere  cinder  alone  would  remain  in  the  coke-oven, 
even  after  the  heat  had  been  kept  up  for  ninety-six  hours.  Perhaps  the  framers  of  the 
report  may  want  to  know  the  distinction  between  cinders  and  coke.  Coke,  if  good, 
sinks  in  water;  bad  coke  or  cinder  swims.  The  reason  of  this  is  very  simple.  The 
longer  and  higher  the  heat  to  which  carbon  from  wood  or  coal  is  exposed  the  more  it 
contracts,  and  consequently  the  denser  it  becomes.  The  volatile  combustible  matter  of 
the  coal  is  employed,  then,  in  producing  the  requisite  temperature  for  coking,  and  the 
oven  is  so  contrived  as  to  retain  the  heat  a  sufficient  time  to  produce  the  necessary 
aggregation  of  the  particles  of  carbon,  or,  in  plain  words,  the  condensation  of  the  coke: 
to  assert  that  this  volatile  combustible  matter  is  lost  is  perfectly  ridiculous.  We  are 
next  informed  that  "an  immense  quantity  of  ammonia  is  lost  by  1)eing  thrown  into  the 
atmosphere,"  and  that  by  "  a  construction  of  the  most  simple  kind  this  loss  might  be 
avoided."  Lord  Dundonald,  about  fifty  years  ago,  had  the  same  idea,  and  tried  it  on 
a  large  scale ;  it  is  unnecessary  to  say  that  it  proved  to  be  a  complete  failure,  although 
sulphate  of  ammonia  was  then  worth  four  or  five  times  its  present  price.  But  uie 
most  absurd  part  of  this  scientific  soap-bubble  is  contained  in  the  last  sentence : — "  100 
tons  in  coking  is  capable  of  producing  on  an  average  about  six  tons  of  this  salt" 
(sulphate  of  ammonia).  Now,  let  us  for  a  few  minutes  imagine  my  Lord  Grey 
desirous  as  (we  have  no  doubt  he  is)  of  making  the  most  of  his  Broomhill  coal. 
Passing  his  eye  down  column  1.  of  Table  6.,  he  sees  at  a  glance  that  100  tons  of  coal 
will  produce  8'674  tons  of  sulphate  of  ammonia,  worth  13/.  per  ton.  Making  a  little 
allowance  for  loss,  he  says  to  himself  "  Well,  call  it  8^  tons ;  and  now  how  much 
sulphuric  acid  is  required  T'  We  will  suppose  him  practically  acquainted  with  Dr. 
Wollaston's  scale,  and  that,  valuing  common  "  chamber  acid  at  uiree  farthings  per 
cent,  he  has  arrived  at  the  following  conclusion  :—> 


100  tons  of  coal,  at  3«.  Ad.  per  ton 
6i  tons  of  sulphuric  acid,  as  above 


will  produce 


8i  tons  of  sulphate  of  ammonia,  worth  110  10 
and  70  tons  of  coke,  at  8«.  6d  per  ton 


/.  ». 

d. 

16  13 

4 

45  10 

0 

62     3 

4 

/.      «. 

d. 

110  10 

0 

29  15 

0 

^~i 


140    5    0 

A  promising  speculation  truly,  if  his  lordship  could  only  economize  "  the  nitrogen 
which  invariably  escapes  in  the  form  of  ammonia."  But,  most  unfortunately,  the  ni- 
trogen does  not  "  invariably  escape  in  the  form  of  ammonia,"  for  in  practice  nine-tenths 
of  it  invariably  escape  in  the  form  of  nitrogen,  as  any  experienced  gas  manufacturer 
can  testify,  and  as  the  experiments  quoted  in  the  report  abundantly  prove,  for  accord- 
ing to  Mr.  F.  C.  Wrightson  (a  pupil  of  Liebig),  who  {vide  Report,  page  6.)  had  fitted 
**  mmself  by  special  study  for  an  undertaking  requiring  so  much  delicacy  of  manipula- 
tion,"— according,  then,  to  Mr.  Wrightson  (page  68.^  the  Binea  coal  and  the  Llangen* 
neck  coal  gave  by  actual  experiment  in  100  parts  0'08  of  ammonia,  or  '310  of  sulphate 
of  ammonia.     Now,  if  we  compare  this  with  Table  6.  we  shall  find  — 

Binea  coal     )  might,  could,  would,  or  j  6*741  )  really  did  j  0-310 
Llangenneck  )  should  produce  (  5*044  )  produce     (  0*310 

or  about  ^th  of  the  quantity  theoretically  obtained  by  Sir  H.  De  la  Beche  and  Dr.  Lyon 


COAL. 


445 


riayfair;  yet  these  are  the  individuals  who  find  fault  with  our  manufacturers,  and 
pretend  to  improve  our  processes.  With  quite  as  much  practical  utility  rnight  these 
gentlemen  have  detailed  to  us  the  quantity  of  pure  diamond  which  the  coals  in  question 
would  produce,  if  we  knew  how ;  as  the  amount  of  ammonia  which  they  might  give  off 
if  they  would.  Of  the  analytical  part  of  the  report  we  will  say  little  naore  than  that  it 
is  in  perfect  keeping  with  the  rest  In  the  first  place,  chloride  of  calcium  is  employed 
to  remove  water  and  ammonia  from  the  gas,  although  a  very  little  practical  knowledge 
of  gas  purification  would  have  taught  the  operator  that,  when  water  and  ammonia  are 
absorbed  by  chloride  of  calcium,  carbonic  acid  is  also  taken  up,  so  as  to  produce  car- 
bonate of  lime  and  muriate  of  ammonia ;  and  as  this  carbonic  acid  must  have  been 
regarded  either  as  ammonia  or  water,  it  follows  that  the  experimental  results  are  value- 
less. The  substance  which  ought  to  have  been  employed  to  absorb  water  and  ammonia 
under  the  circumstances  is  the  fused  or  glacial  phosphoric  acid ;  but  what  real  value  can 
we  attach  to  experiments  made  upon  less  than  half  a  grain  of  coal,  in  which  the  errors^ 
and  errors  there  are,  have  been  multiplied  at  least  300,000  times  ?  For  example,  at 
page  58.,  we  find  "  Anthracite,  from  T.  Aubrey  and  Co."  The  quantity  of  this  coal 
taken  for  analysis  was  0*2763  of  a  grain,  or  rather  more  than  i  of  a  grain.  Now,  sup- 
posing it  had  even  equalled  J  of  a  grain,  then  to  bring  this  to  a  pound  it  must  be  multi- 
plied 21,000  times,  and  to  raise  this  last  to  the  weight  of  water  which  1  lb.  of  such  coal 
could  theoretically  evaporate,  as  represented  at  column  4.  of  Table  6.,  this  21,000  must 
he  multiplied  by  14*593 ;  therefore,  if  any  error  occurred  in  the  analysis  of  this  an- 
thracite coal,  it  has  been  multiplied  upwards  of  306,453  times;  in  regard  to  the 
quantity  of  water  which  1  lb.  of  such  coal  can  evaporate,  as  exhibited  in  column  4.  of 
Table  6.  The  idea^  however,  of  weighing  the  joJoo^^h  of  a  grain  is  perfectly  new  to  us^ 
who  have  always  regarded  even  the  lioth  as  something  too  nearly  approaching  the  im- 
ponderable. These  remarks  apply  equally  to  the  experiments  with  litharge;  no  allow- 
ance is  made,  or  notice  taken  of  the  error  arising  from  the  presence  of  iron  pyrites  in 
the  coal,  although  this  substance  would  reduce  more  than  9  times  its  weight  of  litharge^ 
and  the  error  thus  produced  has  been  multiplied  upwards  of  90,000  times  in  column  6. 
of  Table  4. ;  and  in  the  case  of  the  anthracite  coal  above  mentioned  this  error  has  been 
increased  104,507  times.  Nor  is  the  quantity  of  iron  pyrites  inconsiderable  in  many 
of  these  coals,  for,  according  to  Table  3.,  the  following  contain  a  portion  of  sulphur 
equivalent  to  bisulphuret  of  iron,  as  under: — 

Slievardagh    -        -        -        -        12*67  per  cwt 

Resolven         ...        -  9*50       „ 

Bed  was  -        -        -        -  6*56       „ 

Cwm  Nanty  Gros  -        -        -  5*64       „  _ 

To  pretend  to  attach  any  value  to  such  experiments,  or  to  the  conclusions  drawn 
from  them,  is  a  mere  fallacy,  and,  as  the  whole  of  the  theoretical  part  is  based  upon 
these  analyses,  with  them  it  must  fall  to  the  ground  as  erroneous  and  illusory.  Under 
these  circumstances  it  becomes  necessary  to  inquire  most  carefully  into  the  la'-ge  and 
practical  essays  made  for  the  purpose  of  determining  the  q^uantity  of  water  evaporated 
during  many  successive  hours  by  considerable  quantities  of  each  particular  coaL 
With  a  few  exceptions,  each  coal  was  burnt  for  eight  hours,  and  the  experiment  repeated 
three  times,  the  quantity  of  coal  consumed  and  of  water  evaporated  being  noted  in 
each  instance,  and  an  average  drawn  from  the  three  results  obtained  by  each  coal.  If 
carefully  conducted,  this  method  ought  to  have  furnished  some  valuable  information, 
but  the  discrepancies  in  respect  to  the  three  results  obtained  from  some  of  the  coals 
are  so  enormous  and  unaccountable  as  to  render  the  whole  table  suspicious^  doubtful, 
and  therefore  valueless ;  indeed,  the  differences  observable  between  many  of  the  dif- 
ferent samples  of  coal  are  much  less  than  the  experimental  differences  given  by  one 
and  the  same  coal,  and  which  occasionally  amount  to  little  short  of  twenty  per  cent, 
as  the  following  table  will  show  [see  p.  446.]. 

The  idea  of  forming  a  table  from  experiments  producing  such  discordant  results  is 
altogether  preposterous,  yet  turn  in  what  direction  we  may,  the  same  evidence  of 
blundering  and  incapacity  presents  itself.  In  the  first  place,  the  selection  of  the  coals 
was  bad  and  unfair  in  the  extreme,  and  no  way  calculated  to  answer  the  practical 
end  in  view ;  secondly,  the  proximate  analyses  are  worthless,  from  the  employment  of 
chloride  of  calcium  for  a  purpose  for  which  it  was  not  adapted ;  thirdly,  the  ultimate 
analyses  are  made  in  quantities  too  small  to  entitle  them  to  any  confidence  when  their 
results  are  raised  to  practical  purposes ;  fourthly,  the  litharge  experiments  are  erro- 
neous ;  and  fifthly,  the  practical  essays  by  means  of  the  Admiralty  boiler  are  so  com- 
pletely at  vaiiance  amongst  themselves  as  to  defy  all  arrangement  or  computation. 

The  entire  report  is,  in  fact,  a  disgrace  to  the  age  and  country  we  live  in,  and  carries 
with  it  all  the  internal  evidence  of  a  job.  .        •    -^    j    •      ^ 

As  it  is  possible,  however,  that  the  Admiralty  may  really  be  serious  m  its  desire  to 
ascertain  the  true  value  of  steam-coal,  we  will  venture  to  throw  out  a  few  hmts,  in  order 


of  iron  pyrites  for  which 
no    allowance    has    been 
'made  in  the  litharge  ex- 
periments. 


446 


COBALT. 


NameofCoaL 

Extreme  Difference  in  Three 
Trials  as  to  the  Amuunt 

of  Water  eYaporated 
by  each  respective  Coal. 

Dutfryn  -        -         -         -         - 
Old  Castle       -        -        -        . 

Ward's 

Binea      -        -        -        -        - 

Llangenneck  -        -        -        - 
Mynydd          -        -        -        - 
Three  Quarter         -        -        . 
Graigola          -        -        -        . 
Lydney  -         -         -         -        - 
Pontrepoth      .        -        -        - 
Cwm  Frood     -        -        -        - 
Anthracite       -        -        -        . 
Cwm  Nanty  Gros    -        -        - 
Grangemouth  -        -        -        - 
Broomhill        -        -        .        . 
Resolven          -        -        .        . 
Pontypool        -        -        -        . 
Bedwas  -         -        -        -        - 
Forth  Ma  wr    -        -        -        - 
EbbwVale     -       -       - 
Fordel  Splint  -        -        -        - 

Coleshiil 

Wallsend  Elgin        -        -        . 

2-3  per  cent 
11-         „ 

e-8     „ 

14-7       . 
16-        „ 

4-9       „ 

1-4       n 

21       „ 
11-8       „ 

»1         n 

1-3       „ 
6-6       „ 

4-8       « 

6^       ,. 

6-2       „ 

18-9       „ 

13-4       „ 

9-6       » 
16-7       „ 

H-5       .. 

11-6       „ 

7-3       „ 

that  that  august  body  of  well-paid  functionaries  may  look  before  they  leap  into  a 
subject  80  intimately  connected  with  our  national  interests. 

In  working  a  seam  of  coal,  experience  has  shown  that  the  quality  of  the  coal  is  not 
uniform,  and  that  a  coal  may  be  improving  or  deteriorating  as  the  workings  are  carried 
on,  in  one  or  another  direction.  From  this  it  follows  that  any  particular  coal  examined, 
say  in  1846,  is  by  no  means  to  be  regarded  as  possessing  the  same  value  in  1848,  since  this 
may  have  changed  considerably,  if  the  working  of  the  coal  has  been  carried  on  to  any 
great  extent ;  and  it  is  the  determination  of  this  very  fact  which  constitutes  the  real 
source  of  utility  to  be  derived  from  a  Government  investigation.  The  proximate  value 
of  a  coal  is  soon  determined  by  actual  experiment,  from  the  amount  of  work  done,  and 
a  market  value  is  given  in  accordance  with  these  rough  results ;  but,  when  once  that 
value  has  become  fixed,  there  it  remains  for  many  years,  whether  the  coal  continues 
uniform  or  not,  and  it  is  only  slowly  and  by  degrees  that  the  change  becomes  apparent, 
An  establishment  for  determining  matters  of  this  kind  is,  therefore,  much  needed,  but, 
to  be  useful,  it  must  obviously  be  permanent  Again,  as  the  transmission  of  heat  from 
one  body  to  another  is  proportional  to  the  diflference  of  temperature  between  the  bodies 
themselves,  it  is  clear  that  the  water  operated  on  should  have  one  uniform  temperature 
in  all  the  experiments,  and  there  are  many  reasons  why  this  should  be  the  boiling  point. 
Tlie  quantity  of  water  evaporated  should  not  be  inferred  from  the  quantity  which  has 
escaped  from  a  boiler  during  an  experiment ;  independent  of  the  possibility  of  leakage, 
much  water  is  occasionally  carried  off  mechanically  by  the  steam ;  hence  the  origin  of 
"priming*'  The  most  unobjectionable  method  would  be  to  distil  the  water  and  after- 
wards measure  it,  the  still-head  being  provided  with  a  return-pipe,  as  is  usual,  for  the 
fluid  mechanically  projected.  The  ordinary  modes  of  favouring  the  transmission  of  heat 
from  the  furnace  to  the  boiler,  and  of  preventing  its  escape  in  any  other  direction  than 
into  the  refrigeratory,  should  be  had  recourse  to.  A  chemist  is  of  no  use  for  such  inves- 
tigations ;  if  any  chemical  question  should  arise  out  of  the  experiments,  it  would  be 
better  to  consult  some  one  of  established  reputation.  The  stoker  should  be  intelligent, 
and  practically  acquainted  with  the  different  modes  of  fire  necessary  for  anthracitic, 
open-burning,  and  bituminous,  or  caking  coal ;  for  whilst  the  first  of  these  will  take, 
nay  requires,  eighteen  or  twenty  inches  of  fuel  on  the  bars,  the  last  will  not  bear  more 
than  four  or  six,  without  an  enormous  loss  of  heating-power.  To  this  cause  must  be 
ascribed  much  of  the  discrepancy  apparent  in  the  experimental  results  obtained  by  the 
Admiralty  boiler. — Mr.  Lerois  Thompson,  in  "  T?ie  Chemical  Time»"  for  December,  1 848. 

COBALT.  This  metal  being  difficult  to  reduce  from  its  ores,  is  therefore  very  little 
known,  and  has  not  hitherto  been  employed  in  its  simple  state  in  any  of  the  arts ;  but  its 
oxide  has  been  extensively  used  on  account  of  the  rich  blue  colour  which  it  imparts 
to  glass,  and  the  glazes  of  porcelain  and  stone-ware.     The  principal  ores  of  cobalt  are 


COBALT 


447 


those  designated  by  mineralogists  under  the  names  of  arsenical  cobalt  and  gray  cobalt. 
The  first  contains,  in  addition  to  cobalt,  some  arsenic,  iron,  nickel,  and  occasionally  sil« 
ver,  &c.  The  other  is  a  compound  of  cobalt  with  iron,  arsenic,  sulphur,  and  nickel. 
Among  the  gray  cobalts,  the  ore  most  esteemed  for  its  purity  is  that  of  T^.»aberg  in 
Sweden.  It  is  often  in  regular  crystals,  which  possess  the  lustre  and  color  of  polished 
steel.  The  specific  gravity  of  cobalt  pyrites  is  6-36  to  4*66.  The  Tunaberg  variety 
afibrded  to  Klaproth,  cobalt,  44 ;  arsenic,  55-5 ;  sulphur,  0-5 ;  so  that  it  is  an  arseni- 
uret.  Others,  however,  contain  much  sulphur  as  well  as  iron.  It  imparts  at  the  blowpipe 
a  blue  color  to  borax  and  other  fluxes,  and  gives  out  arsenical  fumes. 

The  ore  being  picked,  to  separate  its  concomitant  stony  matter,  is  pounded  fine 
and  passed  through  a  sieve ;  and  is  also  occasionally  washed.  The  powder  is  then 
spread  on  the  sole  of  a  reverberalory  furnace,  the  flue  of  which  leads  into  a  long  hori- 
zontal chimney.  Here  it  is  exposed  to  calcination  for  several  hours,  to  expel  the  sul- 
phur and  arsenic  that  may  be  present ;  the  former  burning  away  in  sulphurous  acid  gas, 
the  latter  being  condensed  into  the  white  oxyde  or  arsenious  acid,  whence  chiefly  the 
market  is  supplied  with  this  article.  This  calcining  process  can  never  disengage  the 
whole  of  these  volatile  ingredients,  and  there  is  therefore  a  point  beyond  which  it  is 
useless  to  push  it ;  but  the  small  quantities  that  remain  are  not  injurious  to  the  subse- 
quent operations.  The  roasted  ore  is  sifted  anew ;  reduced  to  a  very  fine  powder,  and 
then  mixed  with  2  or  3  parts  of  very  pure  silicious  sand,  i8  be  converted  into  what  is 
called  zaffre.  With  this  product  glasses  are  generally  colored  blue,  as  well  as  enam- 
els and  pottery  glaze.  In  the  works  where  cobalt  ores  are  treated,  a  blue  glass  is  pre- 
pared with  the  zaffre,  which  is  well  known  under  the  name  of  smalt  or  azure  blue. 
This  azure  is  made  by  adding  to  the  zaflTre  2  or  3  parts  of  potash,  according  to  its  rich- 
ness in  cobalt,  and  melting  the  mixture  in  earthen  crucibles.  The  fused  mass  is 
thrown  out  while  hot  into  water ;  and  is  afterwards  triturated  and  levigated  in  mills 
mounted  for  the  purpose.  There  remains  at  the  bottom  of  the  earthen  pot  a  metallic 
lump,  which  contains  a  little  cobalt,  much  nickel,  arsenic,  iron,  &c.  This  is  called 
speiss. 

As'it  is  the  oxyde  of  cobalt  which  has  the  coloring  quality,  the  calcination  serves  the 
purpose  of  oxydizement,  as  well  as  of  expelling  the  foreign  matters. 

A  finer  cobalt  oxyde  is  procured  for  painting  upon  hard  porcelain,  by  boiling  the  cobalt 
ore  in  nitric  acid,  which  converts  the  arsenic  into  an  acid,  and  combines  it  with  the  dif- 
ferent metals  present  in  the  mineral.  These  arseniates,  being  unequally  soluble  in  nitric 
acid,  may  be  separated  in  succession  by  a  cautious  addition  of  carbonate  of  soda  or  pot- 
ash ;  and  the  arseniate  of  cobalt  as  the  most  soluble  remains  unaffected.  It  has  a  rose 
color,  and  is  easil.'  distinguishable,  whence  the  precipitation  may  be  stopped  at  the  proper 
point.  The  above  solution  should  be  much  diluted,  and  the  alkali  should  be  cautiously 
added,  with  frequent  agitation. 

The  cobalt  ores,  rich  in  nickel,  are  exposed  to  slow  oxydizement  in  the  air,  whereby 
the  iron,  cobalt,  arsenic,  and  sulphur  get  oxygenated  by  the  atmospheric  moisture,  but 
the  nickel  continues  in  the  metallic  state.  This  action  of  the  weather  must  not  be 
extended  beyond  a  year,  otherwise  the  nickel  becomes  affected,  and  injures  the  cobalt 
blue.  The  ore  hereby  increases  in  weight,  from  8  to  10  per  cent.  Fig.  362  is  a 
longitudinal  section  of  the  furnace :  fig.  363,  a  horizontal  section  upon  a  level  with  the 
Bole  of  the  hearth.  It  is  constructed  for  wood  fuel,  and  the  hearth  is  composed  of 
fire-bricks  or  tile?.  The  vapors  and  gases  disengaged  in  the  roasting  pass  off 
through  the  flues  a  o,  into  the  channels  6  b,  and  thence  by  c  into  the  common  vent,  or 
poison  chamber.  See  the  representation  of  the  poison  ♦ower  of  Altenberg,  under  the 
article  ARSENia  The  flues  are  cleared  out  by  means  of  openings  left  at  suitable  situa- 
tions in  the  brick- work  of  the  chimneys. 

The  azure  manufacture  is  carried 

on  chiefly  in  winter,  in  order  that 

862  E^^^^^^^^^^P^^*^^^^^^^        the   external  cold    may   favour  the 

more  complete  condensation  of  the 
acids  of  arsenic.  From  3  to  5  cwt 
=*  of  Schlich  (pasty  ore)  are  roasted  at 
'***"  one  operation,  and  its  bed  is  laid 
from  6  to  6  inches  thick.  After  two 
hours,  it  must  be  turned  over;  and 
the  stirring  must  be  repeated  every 
half  hour,  till  no  more  arsenic  is  ob- 
served to  exhale.  The  process  being 
then  finished,  the  ore  must  be  raked 
out  of  the  furnace,  and  another  charge 
introduced. 


1 


II 


448 


COBALT. 


i 


363 


|.^^...A.>yy>/>>/W/'Vx^//>xy/.;d^^M>/^/^^^ 


864 


865 


The  duration  of  the  roasting  it 
regulated  partly  by  the  proportion 
of  sulphur  and  arsenic  present,  and 
partly   by   the   amount    of   nickel; 
which  must  not  be  suffered  to  be- 
come oxydized,  lest  it  should  spoil 
the  color  of  the  smalt.    The  latter 
ores  should  be  but  slightly  roasted, 
so  as  to  convert  the  nickel  into  speiss. 
The  roasted  ore  must  be  sifted  in  a 
safety  apparatus.  The  loss  of  weight 
in   the  roasting  amounts,  upon  the 
average,  to  36  per  cent.  The  roasted 
ore  has  a  brownish  gray  hue,  and  is 
called  safflor  in  German,  and  is  dis- 
tributed into  different  sorts.     F  F  S 
is  the  finest  safre ;  F  S,  fine ;    OS, 
ordinary ;  and  M  S,  middling.  These 
varieties  proceed  from  various  mix- 
tures of   the   calcined  ores.      The 
roasted  ore  is  ground  up  along  with 
sand,  elatriated,  and,  when  dry,  if 
called  zaffre.     It  is  then  mixed  with 
a   suflicient  quantity  of  potash  foi 
converting  the  mixture  into  a  glass. 
Figs.   364   and    365,  represent  a 
round  smalt  furnace,  in  two  vertical 
sections,  at  right  angles  to    each 
other.    The  fire-place  is  vaulted  or 
arched ;  the  flame  orifice  a,  is  in  the 
middle  of  the  furnace ;  6  is  the  feed 
hole  ;  c,  a  tunnel  which  serves  as  an 
ash-pit,  and  to  supply  air ;    d,  open- 
ings  through  which  the  air  arrives 
at  the  fuel,  the  wood  being  placed 
upon  the  vault;    e,  knee  holes  for 
tsiking  out  the  scorise  from  the  pot 
bottoms;   /,  working  orifices,  with 
cast-iron  plates  g,  in  front  of  them. 
Under  these  are  the  additional  out- 
lets h.    The  smoke  and  flame  pass 
off  through  the  orifices  t,  which  ter- 
minate in  expanded  flues,  where  the 
sand  may  be  calcined  or  the  wood 
may   be  baked.     Eight  hours   are 
sufficient  for  one  vitrifying  operation, 
during   which   the   glass  is    stirred 
about  several  times  in  the  earthen  melting  pots.  ^  , 

The  preparation  of  the  different  shades  of  blue  glass  is  considered  a  secret  in  th« 
smelting  works ;  and  marked  with  the  following  letters  : — F  F  F  C,  the  finest ;  F  C| 
fine;  M  C,  middling;  O  C,  ordinary,  A  melting  furnace,  containing  8  pots  of  glass, 
produces  in  24  hours,  from  24  cwts.  of  the  mixture,  19  cwts.  of  blue  glass;  and  from 
^  to  I  cwt  of  scorise  or  speiss  (speise).  The  composition  xpeise,  according  to  Berthier, 
is,— nickel,  490;  arsenic,  37-8;  sulphur,  7-8;  copper,  1-6;  cobalt,  3-2  in  100.  Nickel, 
arsenic,  and  sulphur,  are  its  essential  constituents ;  the  rest  are  accidental,  and  often 
absent  The  freer  the  cobalt  ore  is  from  foreign  metals,  the  finer  is  the  colour,  and 
the  deeper  is  the  shade ;  paler  tints  are  easily  obtained  by  dilution  with  more  glass. 
The  presence  of  nickel  gives  a  violet  tone. 

The  production  of  smalt  in  the  Prussian  states  amounted,  in  1830,  to  7452^  cwts.; 
and  in  Saxony  to  9697  cwts. ;  in  1825,  to  12,310  cwts. 

One  process  for  making  fine  smalt  has  been  given  under  the  title  Azuke  ;  I  shall  in- 
troduce another  somewhat  different  here. 

The  ore  of  cobalt  is  to  be  reduced  to  very  fine  powder,  and  then  roasted  with  much 
care.  One  part,  by  weight,  is  next  to  be  introduced,  in  successive  small  portions,  into 
an  iron  vessel,  in  which  three  parts  of  acid  sulphate  of  potassa  has  been  previously 
fused,  at  a  moderate  temperature.  The  mixture,  at  first  fluid,  soon  becomes  thick  and 
firm,  when  the  fire  is  to  be  increased,  until  the  mass  is  in  perfect  fusion,  and  all 
white  vapours  have  ceased     It  is  then  to  be  taken  out  of  the  crucible  with  an  iron 


J. 


COCHINEAL. 


449 


ladle,  the  crucible  is  to  be  recharged  with  acid  sulphate  of  potash,  and  the  operation 
continued  as  before,  until  the  vessel  is  useless.  The  fused  mass  contains  sulphate  of 
cobalt,  neutral  sulphate  of  potassa,  and  arseniale  of  iron,  with  a  little  cobalt.  It  is  to 
be  pulverized,  and  boiled  in  an  iron  vessel,  with  water,  as  long  as  the  powder  continues 
rough  to  the  touch.  The  white,  or  yellowish  white  residue,  may  be  allowed  to  separate 
from  the  solution,  either  by  deposition  or  filtration.  Carbonate  of  potassa,  free  from 
siliea,  is  then  to  be  added  to  the  solution,  and  the  carbonate  of  cobali  thrown  down  is 
to  be  separated  and  well  washed,  if  possible,  with  warm  water ;  the  same  water  may  be 
used  to  wash  other  portions  of  the  fused  mass.  The  filtered  liquid  which  first  passes 
is  a  saturated  solution  of  sulphate  of  potassa :  being  evaporated  to  dryness  in  an  iron  res- 
sel,  it  may  be  reconverted  into  acid  sulphate  by  fusing  it  with  one  half  its  weight  of 
sulphuric  acid :  this  salt  is  then  as  useful  as  at  first. 

The  oxyde  of  cobalt  thus  obtained  contains  no  nickel ;  so  little  oxyde  of  iron  is  pre- 
sent, that  infusion  of  galls  does  not  show  its  presence ;  it  may  contain  a  little  copper,  if 
that  metal  exists  in  the  ore,  but  it  is  easily  separated  by  the  known  methods.  Sometimes 
sulphureted  hydrogen  will  produce  a  yellow  brown  precipitate  in  the  solution  of  the 
fused  mass ;  this,  however,  contains  no  arsenic,  but  is  either  sulphuret  of  antimony  or 
bismuth,  or  a  mixture  of  bath. 

It  has  been  found  advantageous  to  add  to  the  fused  mass  sulphate  of  iron,  calcined  to 
redness,  and  one  tenth  of  nitre  when  the  residue  is  arseniate  of  iron,  and  contains  no 
arseniate  of  cobalt.  There  is  then  no  occasion  to  act  upon  the  residue  a  second  time  for 
the  cobalt  in  it. 

This  process  is  founded  on  the  circumstances  that  the  sulphate  of  cobalt  is  not  de- 
composed by  a  red  heat,  and  that  the  arseniates  of  iron  and  cobalt  are  insoluble  in 
all  neutral  liquids.  It  is  quite  evident,  that,  to  obtain  a  perfect  result,  the  excess 
of  acid  in  the  bisulphate  of  potassa  must  be  completely  driven  off  by  the  red  heat 
applied. 

110,646  lbs.  of  smalts  were  imported  into  the  United  Kingdom  in  1835,  and  96,949 
were  retained  for  home  consumptin.     In  1834,  only  16,223  lbs.  were  retained. 

In  1835,  322,562  lbs.  of  zaffres  were  imported,  and  336,824  are  stated  to  have  been 
retained,  which  is  obviously  an  error,    284,000  lbs.  were  retained  in  1834. 

COCCULUS  INDICUS,  or  Indian  berry,  is  the  fruit  of  the  Menispermum  Coccultu, 
a  large  tree,  which  grows  upon  the  coasts  of  Malabar,  Ceylon,  &c.  The  fruit  is 
blackish,  and  of  the  size  of  a  large  pea.  It  owes  its  narcotic  and  poisonous  qualities  to 
the  vegeto-alk aline  chemical  principle  called  picrotoxiay  of  which  it  contains  about  one 
fiftieth  part  of  its  weight.  It  is  sometimes  thrown  into  waters  to  intoxicate  or  kill  fishes; 
and  it  is  said  to  have  been  employed  to  increase  the  inebriating  qualities  of  ale  or  beer. 
Its  use  for  this  purpose  is  prohibited  by  act  of  parliament,  under  a  penalty  of  200/.  upon 
fche  brewer,  and  500/.  upon  the  seller  of  the  drug. 

COCHINEAL  was  taken  in  Europe  at  first  for  a  seed,  but  was  proved  by  the  obser- 
rations  of  Lewenhoeck  to  be  an  insect,  being  the  female  of  that  species  of  shield-lonse^ 
or  coccusy  discovered  in  Mexico,  so  long  ago  as  1518.  It  is  brought  to  us  from  Mexico^ 
where  the  animal  lives  upon  the  cactus  opuniia  or  nopal.  Two  sorts  of  cochineal 
are  gathered — the  wild,  from  the  woods,  called  by  the  Spanish  name  grana  silvestra ; 
and  the  cultivated,  or  the  grana  fina,  termed  also  meaUque^  from  the  name,  of  a  Mexican 
province.  The  first  is  smaller,  and  covered  with  a  cottony  down,  which  increases  its 
bulk  with  a  matter  useless  in  dyeing ;  it  yields,  therefore,  in  equal  weight,  much  less 
color,  and  is  of  inferior  price  to  that  of  the  fine  cochineal.  But  these  disadvantages 
are  compensated  in  some  measure  to  the  growers  by  its  being  reared  more  easily,  and 
less  expensively ;  partly  by  the  effect  of  its  down,  which  enables  it  better  to  resist  raine 
and  storms.  • 

The  wild  cochineal,  when  it  is  bred  upon  the  field  nopal,  loses  in  part  the  tenacity 
and  quantity  of  its  cotton,  and  acquires  a  size  double  of  what  it  has  on  the  wild  opuntias. 
It  may  therefore  be  hoped,  that  it  will  be  improved  by  persevering  care  in  the  rearing 
of  it,  when  it  will  approach  more  and  more  to  fine  cochineaL 

The  fine  cochineal,  when  well  dried  and  well  preserved,  should  have  a  gray  colour, 
bordering  on  purple.  The  gray  is  owing  to  the  powder,  which  naturally  covers  it, 
and  of  which  a  little  adheres ;  so  also  to  a  waxy  fat.  The  purple  shade  arises  from  the 
colour  extracted  by  the  water  in  which  they  were  killed.  It  is  wrinkled  with  parallel 
furrows  across  its  back,  which  are  intersected  in  the  middle  by  a  longitudinal  one; 
hence,  when  viewed  by  a  magnifier,  or  even  a  sharp  naked  eye,  especially  after  being 
swollen  by  soaking  for  a  little  in  water,  it  is  easily  distinguished  from  the  factitious, 
smooth,  glistening,  black  grains,  of  no  value,  called  East  India  cochineal,  with  which  it 
is  often  shamefully  adulterated  by  certain  London  merchants.  The  genuine  cochineal 
has  the  shape  of  an  egg,  bisected  through  its  long  axis,  or  of  a  tortoise,  being  rounded 
like  a  shield  upon  the  back,  flat  upon  the  belly,  and  without  wings. 

These  female  insects  are  gathered  off  the  leaves  of  the  nopal  plant,  after  it  has  ripened 


450 


COCfflNEAL. 


COCHINEAL. 


451 


1 


1 


Z5  » 


its  fruit,  a  few  only  being  left  for  brood,  and  are  killed,  either  by  a  momentary  immer- 
sion  in  boiling  water,  by  drying  upon  heated  plates,  or  in  ovens;  the  ^^^.^^^^"^-^j;.^" 
ash-gray  color,  constituting  the  silver  cochineal,  or  jaspeada;  the  second  are  Wack^h, 
call^  Zgra,  and  are  most  esteemed,  being  probably  driest ;  the  first  are  reddish  brown 
aXeckoned  inferior  to  the  other  two.  The  dry  cochineal  being  sifted,  the  dust,  with 
the  imperfect  insects  and  fragments  which  pass  through,  are  sold  under  the  name  of 

^C^dihineal  keeps  for  a  long  time  in  a  dry  place.  Hellot  says  that  he  has  tried  some 
130  years  old,  which  produced  the  same  effect  as  new  cochineal.  r       v 

We  are  indebted  to  MM.  Pelletier  and  Caventou  for  a  chemical  investigation  of  cochi- 
neal, in  which  its  coloring  matter  was  skilfully  eliminated. 

Purified  sulphuric  ether  acquired  by  digestion  with  it  a  golden  yellow  color,  amounting 
by  Dr.  John  to  one  tenth  of  the  weight  of  the  insect.    This  infusion  left,  on  evaporation, 

a  fatty  wax  of  the  same  color.  oa  •  r    •  «- 

Cochineal,  exhausted  by  ether,  was  treated  with  alcohol  at  AQP  B.  After  30  infusions 
in  the  di^^ester  of  M.  Chevreul,  the  cochineal  continued  to  retam  color,  although  tne 
alcohol  had  ceased  to  have  any  effect  on  it.  The  first  alcoholic  liquors  were  of  a  red 
verging  on  yellow.  On  cooling,  they  let  fall  a  granular  matter.  By  spontaneous  evapo- 
ration, this  matter,  oC  a  fine  red  color,  separated,  assuming  more  of  the  crystalline  ap- 
pearance.    These  species  of  crystals  dissolved  entirely  in  water,  which  they  tmged  ol  « 

^^Thls^ matter  has  a  very  brilliant  purple-red  color;  it  adheres  strongly  to  the  sides  of 
the  vessels ;  it  has  a  granular  and  somewhat  ciystalline  aspect,  very  different,  however, 
from  those  compound  crystals  alluded  to  above ;  it  is  not  altered  by  the  air,  nor  does  it 
sensibly  attract  moisture.  Exposed  to  the  action  of  heat,  it  melts  at  about  the  fiftieth 
degree  centigrade  (122?  Fahr.).  At  a  higher  temperature  it  swells  up,  and  is  decoin- 
posed  with  the  production  of  carbureted  hydrogen,  much  oil,  and  a  small  quantity  ol 
water,  very  slightly  acidulous.     No  trace  of  ammonia  was  found  m  these  products. 

The  coloring  principle  of  cochineal  is  very  soluble  in  water.  By  evaporation,  the 
Uquid  assumes  the  appearance  of  sirup,  but  never  yields  crystals.  .I'^/^qmres  of  this 
matter  a  portion  almost  imponderable  to  give  a  perceptible  tinge  of  bright  purplish  red  to 
a  large  body  of  water.  Alcohol  dissolves  this  coloring  substance,  but,  as  we  have  al- 
ready  stated,  the  more  highly  it  is  rectified  the  less  of  it  does  it  dissolve.  Sulphuric  ether 
does  not  dL^solve  the  coloring  principle  of  cochineal;  but  weak  acids  do,  possibly  owing 
to  their  water  of  dUution.  No  acid  precipitates  it  in  its  pure  state.  This  coloring  prin- 
ciple,  however,  appears  to  be  precipitable  by  all  the  acids,  when  it  is  accompanied  by  the 
animal  matter  of  the  cochineal.  . 

The  affinity  of  alumina  for  the  coloring  matter  is  very  remarkable.  When  that  eartft, 
newly  precipitated,  is  put  into  a  watery  solution  of  the  coloring  principle,  this  is  imme- 
diately seized  by  the  alumina.  The  water  becomes  coloriess,  and  a  fine  red  lake  is  ob- 
tained, if  we  operate  at  the  temperature  of  the  atmosphere ;  but  if  the  liquor  has  beei 
hot,  the  color  passes  to  crimson,  and  the  shade  becomes  more  and  more  violet,  accord 
ing  to  the  elevation  of  the  temperature,  and  the  continuance  of  the  ebuUition. 

The  salts  of  tin  exercise  upon  the  coloring  matter  of  cochineal  a  remarkable  action. 
The  muriatic  protoxyde  of  tin  forms  a  very  abundant  violet  precipitate  in  the  liquid 
This  precipitate  verges  on  crimson,  if  the  salt  contains  an  excess  of  acid.  Jhe  munaUe 
deutoxyde  of  tin  produces  no  precipitate,  but  changes  the  color  to  scarlet-red.    If  gelati- 
nous alumina  be  now  added,  we  obtain  a  fine  red  precipitate,  which  does  not  pass  to 

"'To^'thi^co Wng  principle  the  name  carminium  bas  been  given,  because  it  forms  the 

basis  of  the  pigment  called  carmine.  ,  .  ,  .  ,  •  i.    • 

The  process  followed  in  Germany  for  making  carmine,  which  consists  in  pouring  a 
certain  quantity  of  solution  of  alum  into  a  decoction  of  cochineal,  is  the  most  simple  of 
all  and  affords^in  explanation  of  the  formation  of  carmine,  which  is  merely  the  car- 
m^nfum  and  the  animal  matter  precipitated  by  the  excess  of  acid  m  the  salt,  which  has 
teken  down  with  it  a  small  quantity  of  alumina ;  though  it  appears  that  alumina  ought 
not  to  be  regarded  as  essential  to  the  formation  of  carmine.  In  fact,  by  another  proceaa 
^lled  bv  the  name  of  Madame  Cenette  of  Amsterdam,  the  carmine  is  thrown  down  by 
Souring  into  the  decoction  of  cochineal  a  certain  ouantity  of  the  bmoxalate  of  potash, 
^hen  carbonate  of  soda  is  added,  then  carminateJ  lake  also  falls  down.   That  carmine 
is  a  triple  compound  of  animal  matter,  carminium,  and  an  acid,  appears  from  the  cir- 
cumstance that  liquors  which  have  afforded  their  carmine,  when  a  somewhat  strong 
ac.Tis  poured  into  them,  yield  a  new  formation  of  carmine  by  the  precipitation  of  the 
Z  porCns  of  the  animaf  matter.     But  whenever  the  whole  animal  matter  is  thrown 
Swrthe  decoctions,  although  still  much  charged  with  the  colourmg  prmciple,  can 
Xrd  no  more  canine.     sSch  decoctions  may  be  usefully  employed  to  make  car- 
minated  lakeZ  saturating  the  acid  with  a  slight  excess  of  alkali,  and  adding  gelatmous 
S^l     The  precipitates  obtained,  on  aiding  acid  to  the  alkaline  decocUons  of 


earmines,  since  they  do  not  contain  alumina;  but  the  small  quantity  of  alumina  which 
is  thrown  down  by  alum  in  the  manufacture  of  carmine,  augments  its  bulk  and  x^ight 
It  gives,  besides,  a  greater  lustre  to  the  color,  even  though  diluting  and  weakening  it  a 

little. 

The  carmines  found  in  the  shops  of  Paris  were  analyzed,  and  yielded  the  same  pro- 
ducts. They  are  decomposed  by  the  action  of  heat,  with  the  diffusion  at  first  of  a  very 
strong  smell  of  burning  animal  matter,  and  then  of  sulphur.  A  white  powder  remained, 
amounting  to  about  one  tenth  of  the  matter  employed,  and  which  was  found  to  be  alu- 
mina. Other  quantities  of  carmine  were  treated  with  a  solution  of  caustic  potash,  which 
completely  dissolved  them,  with  the  exception  of  a  beautiful  red  powder,  not  acted  on  by 
potash  and  concentrated  acids,  and  which  was  recognised  to  be  red  sulphuret  of  mercurj 
or  vermilion.  This  matter,  evidently  foreign  to  the  carmine,  appears  to  have  been  ad- 
ded in  order  to  increase  its  weight. 

The  preceding  observations  and  experiments  seem  calculated  to  throw  some  light  on 
the  art  of  dyeing  scarlet  and  crimson.  The  former  is  effected  by  employing  a  cochineal 
bath,  to  which  there  have  been  added,  in  determinate  proportions,  acidulous  tartrate  of 
potash,  and  nitro-muriatic  deutoxyde  of  tin.  The  effect  of  these  two  salts  is  now  well 
known.  The  former,  in  consequence  of  its  excess  of  acid,  tends  to  redden  the  color, 
and  to  precipitate  it  along  with  the  animal  matter ;  the  latter  acts  in  the  same  manner, 
at  first  by  its  excess  of  acid,  then  by  the  oxyde  of  tin  which  falls  down  also  with  the 
carmine  and  animal  matter,  and  is  fixed  on  the  wool,  with  which  it  has  of  itself  a  strong 
tendency  to  combine.  MM.  Pelletier  and  Caventou  remark,  that  "  to  abtain  a  beautiful 
shade,  the  muriate  of  tin  ought  to  be  entirely  at  the  maximum  of  oxydizement ;  and  it 
is  in  reality  in  this  state  that  it  must  exist  in  the  solution  of  tin  prepared  according  to 
the  proportions  prescribed  in  M.  Berthollet*s  treatise  on  dyeing." 

We  hence  see  why,  in  dyeing  scarlet,  the  employment  of  alum  is  carefully  avoided,  as 
this  salt  tends  to  convert  the  shade  to  a  crimson.  The  presence  of  an  alkali  would  seem 
less  to  be  fieared.  The  alkali  would  occasion,  no  doubt,  a  crimson-colored  bath ;  but  it 
would  be  easy  in  this  case  to  restore  the  color,  by  using  a  large  quantity  of  tartar.  We 
shoukl,  therefore,  procure  the  advantage  of  having  a  bath  better  charged  with  coloring 
matter  and  animal  substance.  It  is  for  experience  on  the  large  scale  to  determine  this 
point.  As  to  the  earthy  salts,  they  must  be  carefully  avoided ;  and  if  the  waters  be  se- 
lenitish,  it  would  be  a  reason  foi  adding  a  Jttle  alkali. 

To  obtain  crimson,  it  is  sufficient,  as  we  know,  to  add  alum  to  the  cochineal  bath,  or 
to  boil  the  scarlet  cloth  in  alum  water.  It  is  also  proper  to  diminish  the  dose  of  the  salt 
of  tin,  since  it  is  found  to  counteract  the  action  of  the  alum. 

The  alkalis  ought  to  be  rejected  as  a  means  of  changing  scarlet  to  crimson.  In  fact, 
crimsons  by  this  process  cannot  be  permanent  colors,  as  they  pass  into  reds  by  the  actios 
of  acids. 

According  to  M.  Von  Grotthuss,  carmine  may  be  deprived  of  its  golden  shade  bj 
ammonia,  and  subsequent  treatment  with  acetic  acid  and  alcohol.  Since  this  fact  was 
made  known,  M.  Herschel,  color  maker  at  Halle,  has  prepared  a  most  beautiful 
carmine. 

The  officers  of  Her  Majesty's  Customs  have  lately  detected  a  system  of  adulterating 
cochineal,  which  has  been  practised  for  many  years  upon  a  prodigious  scale  by  a  mercan- 
tile house  in  London.  I  have  analyzed  about  100  samples  of  such  cochineal,  from  which 
It  appears  that  the  genuine  article  is  moistened  with  gum-water,  agitated  in  a  box  of 
leather  bag,  first,  with  sulphate  of  baryta  in  fine  powder,  afterward  with  bone  of  ivory 
black,  to  give  it  the  appearance  of  negra  cochineal,  and  then  dried.  By  this  means  about 
12  per  cent  of  worthless  heavy  spar  is  sold  at  the  price  of  cochineal,  to  the  enrichment 
of  the  sophisticators,  and  the  disgrace  and  injury  of  Biitish  trade  and  manufactures. 

The  specific  gravity  of  genuine  cochineal  is  r25;  that  of  the  cochineal  loaded  with 
the  barytic  sulphate,  r35.  This  was  taken  in  oil  of  turpentine  and  reduced  to  water  as 
unity,  because  the  waxy  fat  of  the  insects  prevents  the  intimate  contact  of  the  latter 
liquid  with  them,  and  the  ready  expulsion  of  air  from  their  wrinkled  surface.  They  are 
not  at  all  acted  upon  by  the  oil,  but  are  rapidly  altered  by  water,  especially  when  they 
have  been  gummed  and  barytitied. 


December,  1851    • 

18.50    - 

- 

12  MonlhB,  18.51    - 

- 

1850    - 

- 

1849    - 

- 

1848  •  - 

• 

I.«a«ie(i. 


1,203  bags 
1,6!>5  — 
16,561  — 
17,765  — 
12.604  — 
13.521    — 


Delivered. 


692  bags 
595  — 
16.180  — 
13,096  — 
13,594  — 
11,506    — 


Stock,  l8t  of  January. 


—  bags 


9.G01 
8.620 
3,951 
4.933 


Humboldt  states  that  so  long  ago  as  the  year  1736,  there  was  imported  into  Europe 
from  South  America  cochineal  to  the  value  of  15  millions  of  francs.  Its  high  price  had 
for  a  long  time  induced  dyers  to  look  out  for  cheaper  substitutes  in  dyeing  red,  and 
lince  science  has  introduced  so  many  improvements  in  tinctorial  processes,  both  madder 
and  lac  have  been  made  to  supersede  cochineal  to  a  very  great  extent     Its  pnce  has,  in 


452 


COFFEE. 


COFFEE. 


453 


r) 


V-  ' 


consequence  of  this  substitntion,  as  well  as  from  more  saccessfal  modes  of  cultivation, 
fallen  very  greatly  of  late  years.  In  January,  1852,  the  prices  of  Honduras  cochineal 
ranged  from  2?.  9cL  to  5«.  per  lb.,  and  Mexican  from  2s.  7a.  to  3«.  4J.  per  lb. 

COCOA,  STEARINE,  and  ELAINE.  Mr.  Soames  obtained  a  patent  in  September, 
1829,  for  making  these  useful  articles,  by  the  following  process  :  — 

He  takes  the  substance  called  cocoa-nut  oil,  in  the  state  of  lard,  in  which  it  is  imported 
into  this  country,  and  submits  it  to  a  strong  hydraulic  pressure,  having  made  it  up  in  smaB 
packages,  3  or  4  inches  wide,  2  feet  long,  and  1  or  1^  inches  thick.  These  packages  art 
formed  by  first  wrapping  up  the  said  substance  in  a  strong  linen  cloth,  of  close  texture^ 
and  then  in  an  outward  wrapper  of  strong  sail  cloth.  The  packages  are  to  be  placed  sidf 
by  side,  in  single  rows.,  between  the  plates  of  the  press,  allowing  a  smaH  space  betweei 
the  packages  for  the  escape  of  the  elaine. 

The  temperature  at  which  the  pressure  is  begun,  should  be  from  about  50  to  55  degrees, 
or  in  summer  as  nearly  at  this  pitch  as  can  be  obtained,  and  the  packages  of  the  said 
substance  intended  for  pressure,  should  be  exposed  for  several  hours  previously  to  about 
the  same  temperature.  When  the  packages  will  no  longer  yield  their  oil  or  elaine  freely 
at  this  temperature,  it  is  to  be  gradually  raised ;  but  it  must  at  no  time  exceed  65  degrees, 
and  the  lower  the  temperature  at  which  the  separation  can  be  effected,  the  better  will  be 
the  quality  of  the  oil  expressed. 

When  the  packages  are  sufficiently  pressed,  that  is,  when  they  will  give  out  no  more 
oil,  or  yield  it  only  in  drops  at  long  intervals,  the  residuum  in  them  is  to  be  taken  out  and 
cleansed  and  purified,  which  is  done  by  melting  it  in  a  well-tinned  copper  vessel,  which 
is  fixed  in  an  outer  vessel,  having  a  rdcant  space  between,  closed  at  the  top,  into  which 
steam  is  admitted,  and  the  heat  is  kept  up  moderately  for  a  sufficient  time  to  allow  the 
impurities  to  subside ;  but  if  a  still  higher  degree  of  purity  is  required,  it  is  necessary  to 
pass  it  through  filters  of  thick  flannel  lined  with  blotting  paper. 

Having  been  thus  cleansed  or  purified,  it  is  fit  for  the  manufacture  of  candles,  which 
are  made  by  the  ordinary  process  used  in  making  mould  tallow  candles.  Having  thus 
disposed  of  the  stearine,  or  what  is  called  the  first  product,  he  proceeds  with  the  elaine 
or  oil  expressed  from  it,  and  which  he  calls  the  second  product,  as  follows :  that  is  to 
say,  he  purifies  it  by  an  admixture,  according  to  the  degree  of  its  apparent  foulness,  of 
from  1  to  2  per  cent,  by  weight  of  the  sulphuric  acid  of  commerce,  of  about  1*80  specific 
gravity,  diluted  with  six  times  its  weight  of  water.  The  whole  is  then  to  be  violently 
agitated  by  mechanical  means,  and  he  prefers  for  this  purpose  the  use  of  a  vessel  con- 
structed on  the  principle  of  a  common  barrel  churn.  When  sufficiently  agitated,  it  will 
have  a  dirty  whitish  appearance,  and  is  then  to  be  d  awn  off  into  another  vessel,  in  which 
it  is  to  be  allowed  to  settle,  and  any  scum  that  rises  is  to  be  carefully  taken  off.  In  a 
day  or  two  the  impurities  will  be  deposited  at  the  bottom  of  the  oil,  which  will  then  be- 
eome  clear,  or  nearly  so,  and  it  is  to  be  filtered  through  a  thick  woollen  doth^  aAer  which 
it  will  be  fit  for  burning  in  ordinary  lamps  and  for  other  uses. 

The  process  of  separating  the  elaine  from  the  stearine,  by  pressure,  in  manner  afore- 
said, had  never  before  beenv  applied  to  the  substance  called  cocoa-nut  oil,  and  consequently 
no  product  had  heretofore  '^een  obtained  thereby  from  that  substance,  fit  for  being  ma- 
nufactured into  candles  in  the  ordinary  way,  or  for  ^eing  refined  by  any  of  the  nsni? 
modes,  so  as  to  burn  in  ordinary  lamps,  both  which  objects  are  obtained  by  this  method 
of  preparing  or  manufacturing  the  said  substance. 

Candles  well  made  from  the  above  material  are  a  very  superior  article.  The  light 
produced  is  more  brilliant  than  from  the  same  sized  candle  made  of  tallow ;  the  flame  is 
perfectly  colorless,  and  the  wick  remains  free  from  cinder,  or  any  degree  of  foulness  du- 
ring combustion. 

COFFEE.  The  coffee  is  the  seed  of  a  tree  of  the  family  rubiacea,  and  belongs  to  the 
Pentandria  monogynia  of  Linnaeus.  There  are  several  species  of  the  genus,  but  the  only 
one  cultivated  is  the  Coffcea  Arahica^  a  native  of  Upper  Ethiopia  and  Arabia  Felix.  It 
rises  to  the  height  of  15  or  20  feet ;  its  trunk  sends  forth  opposite  branches  in  pairs  above 
and  at  right  angles  to  each  other ;  the  leaves  resemble  those  of  the  common  laurel,  al- 
though not  so  dry  and  thick.  From  the  angle  of  the  leaf-stalks  small  groups  of  white 
flowers  issue,  which  are  like  those  of  the  Spanish  jasmine.  These  flowers  fade  very  soon, 
and  are  replaced  by  a  kind  of  fruit  not  unlike  a  cherry,  which  contains  a  yellow  glairy 
fluid,  enveloping  two  small  seeds  or  berries  convex  upon  one  side,  flat  and  furrowed  upon 
the  other  in  the  direction  of  the  long  axis.  These  seeds  are  of  a  homy  or  cartilaginous 
nature ;  they  are  glued  together,  each  being  surrounded  with  a  peculiar  coriaceous  mem- 
brane.   They  constitute  the  coffee  of  commerce. 

It  was  not  till  towards  the  end  of  the  15th  century  that  the  coffee-tree  began  to  be  cul- 
tivated in  Arabia.  Historians  usually  ascribe  the  discovery  of  the  use  of  coffee  as  a  be* 
verage  to  the  superior  of  a  monastry  there,  who,  desirous  of  preventing  the  monks  from 
sleeping  at  their  nocturnal  services,  made  them  drink  ihe  infusion  of  coffee  upon  the  re- 
port of  shepherds,  who  pretended  that  their  flocks  were  more  lively  after  browsing  on  the 
fruit  of  that  *)lant.    The  use  of  coffee  was  soon  rapidly  spread,  but  it  encountered  much 


opposition  on  thft  part  of  the  Turkish  government,  and  became  the  occasion  of  public 
assemblies.  Under  the  reign  of  Amurath  Til.  the  mufti  procured  a  law  to  shut  all  the  cof- 
fee-houses, and  this  act  of  suppression  was  renewed  under  the  minority  of  Mahomet  IV, 
It  was  not  till  1554,  under  Solyman  the  Great,  that  the  drinking  of  coffee  was  accredited  in 
Constantinople ;  and  a  century  elapsed  before  it  was  known  in  London  and  Paris.  Soly- 
man Aga  introduced  its  use  into  the  latter  city  in  1669,  and  in  1672  an  Armenian  estab- 
lished the  first  cafe  at  the  fair  of  Saint  Germain. 

When  coffee  became  somewhat  of  a  necessary  of  life,  from  the  influence  of  habit 
among  the  people,  all  the  European  powers  who  had  colonies  between  the  tropics,  pro- 
jected to  form  plantations  of  coffee-trees  in  them.  The  Dutch  were  the  first  who  trans- 
ported the  coffee  plant  from  Moka  to  Batavia,  and  from  Batavia  to  Amsterdam.  In 
1714  the  magistrates  of  that  city  sent  a  root  to  Louis  XIV.,  which  he  caused  to  be 
planted  in  the  Jardin  du  Roi.  This  became  the  parent  stock  of  all  the  French  coffee  plan- 
tations in  Martinique. 

The  most  extensive  culture  of  coffee  is  still  in  Arabia  Felix,  and  principally  in  the 
kingdom  of  Yemen,  towards  the  cantons  of  Aden  and  Moka.  Although  these  countries 
are  very  hot  in  the  plains,  they  possess  mountains  where  the  air  is  mild.  The  coffee  is 
generally  grown  half  way  up  on  their  slopes.  When  cultivated  on  the  lower  grounds  it 
is  always  surrounded  by  large  trees  which  shelter  it  from  the  torrid  sun,  and  prevent  its 
fruit  from  withering  before  their  maturity.  The  harvest  is  gathered  at  three  periods ;  the 
most  considerable  occurs  in  May,  when  the  reapers  begin  by  spreading  cloths  under  the 
trees,  then  shaking  the  branches  strongly,  so  as  to  make  the  fruit  drop,  which  they  collect, 
and  expose  upon  mats  to  dry.  They  then  pass  over  the  dried  berries  a  very  heavy  roller, 
to  break  the  envelops,  which  are  afterwards  winnowed  away  with  a  fan.  The  interior 
bean  is  again  dried  before  being  laid  up  in  store. 

In  Demarara,  Berbice,  and  some  of  our  West  India  islands,  where  much  good  coffee 
is  now  raised,  a  different  mode  of  treating  the  pulpy  fruit  and  curing  the  beans  is 
adopted.  When  the  cherry-looking  berry  has  assumed  a  deep-red  color  it  is  gathered, 
and  immediately  subjected  to  the  operations  of  a  mill  composed  of  two  wooden  rollers, 
furnished  with  iron  plates,  which  revolve  near  a  third  fixed  roller  called  the  chopt. 
The  berries  are  fed  into  a  hopper  above  the  rollers,  and  falling  down  between  them  and 
the  chops,  they  are  stripped  of  their  outer  skin  and  pulp,  while  the  twin  beans  are  se- 
parated from  each  other.  These  beans  then  fall  upon  a  sieve,  which  allows  the  skin  and 
the  pulp  to  pass  through,  while  the  hard  beans  accumulate  and  are  progressively  slid 
over  the  edge  into  baskets.  They  are  next  steeped  for  a  night  in  water,  thoroughly 
washed  in  the  morning,  and  afterwards  dried  in  the  sun.  They  are  now  ready  for  the 
peeling  mill,  a  wooden  edge  wheel  turned  vertically  by  a  horse  yoked  to  the  extremity  of 
its  horizontal  axis.  In  travelling  over  the  coffee,  it  bursts  and  detaches  the  coriaceous 
or  parchment-like  skin  which  surrounds  each  hemispherical  bean.  It  is  then  freed  from 
the  membranes  by  a  winnowing  machine,  in  which  four  pieces  of  tin  made  fast  to  an  axle 
are  caused  to  revolve  with  great  velocity.  Com  fanners  would  answer  better  than  this 
nide  instmment  of  negro  invention.  The  coffee  is  finally  spread  upon  mats  or  tablci| 
picked  clean,  and  packed  up  for  shipment. 

The  most  highly  esteemed  coffee  is  that  of  Moka.  It  Las  a  smaller  and  a  roundei 
bean;  a  more  agreeable  taste  and  smell  than  any  other.  Its  xtlor  is  yellow.  Next 
to  it  in  European  reputation  are  the  Martinique  and  Bourbon  coffees ;  the  former  is 
larger  than  the  Arabian,  and  more  oblong ;  it  is  rounded  at  the  ends ;  its  color  is  green- 
i«h,  and  it  preserves  almost  always  a  silver  gray  pellicle,  which  comes  off  in  the  roasting. 
The  BourbDn  coffee  approaches  nearest  to  the  Moka,  from  which  it  originally  sprang. 
The  Saint  Domingo  coffee  has  its  two  extremities  pointed,  and  is  much  less  esteem^ 
than  the  preceding. 

The  coffee-tree  flourishes  in  hilly  districts,  where  its  root  can  be  kept  dry,  while  its 
leaves  are  refreshed  with  frequent  showers.  Rocky  ground,  with  rich  decomposed 
mould  in  the  fissures,  agrees  best  with  it.  Though  it  would  grow,  as  we  have  said,  to 
the  height  of  15  or  20  feet,  yet  it  is  usually  kept  down  by  pruning  to  that  of  five  feet, 
for  increasing  the  production  of  the  fruit,  as  well  as  for  the  convenience  of  crop- 
ping. It  begins  to  yield  fruit  the  third  year,  but  is  not  in  full  bearing  till  the  fifth, 
does  not  thrive  beyond  the  twenty-fifth,  and  is  useless  in  general  at  the  thirtieth. 
In  the  coffee  husbandry,  the  plants  should  be  placed  eight  feet  apart,  as  the  trees  throw 
out  extensive  horizontal  branches,  and  in  holes  ten  or  twelve  feet  deep,  to  secure  a  con- 
stant supply  of  moisture. 

Coffee  has  been  analyzed  by  a  great  many  chemists,  with  considerable  diversity  of 
results.  The  best  analysis  perhaps  is  that  of  Schrader.  He  found  that  the  raw  beans 
distilled  with  water  in  a  retort  communicated  to  it  their  flavor  and  rendered  it  turbid, 
whence  they  seem  to  contain  some  volatile  oil.  On  reboiling  the  beans,  filtering,  and 
evaporating  the  liquor  to  a  sirup,  adding  a  little  alcohol  till  no  more  matter  was  preci- 
pitated, and  then  evaporating  to  dryness,  he  obtained  17*58  oer  cent,  of  a  yellowish- 


454 


COFFEE. 


COFFEE. 


455 


la-  ^ 


brown  transparent  extract,  which  constitutes  the  characteristic  part  of  coffee,  thongh  it 
is  not  in  that  state  the  pure  proximate  principle,  called  caffeine.  Its  most  remarkable 
reaction  is  its  producing,  with  both  the  protoxyde  and  the  peroxyde  salts  of  iron,  a  fine 
grass  green  color,  while  a  dark  green  precipitate  falls,  which  re-dissolves  when  an  acid 
is  poured  into  the  liquor.  It  produces  on  the  solution  of  the  salts  of  copper  scarcely 
any  effect,  till  an  alkali  be  added,  when  a  very  beautiful  green  color  is  produced,  which 
may  be  employed  in  paintin?.  Coifee  beans  contain  also  a  resin,  and  a  fatty  substance 
somewhat  like  suet.  According  to  Robiquet,  ether  extracts  from  coffee  beans  nearly  10 
per  cent,  of  resin  and  fat,  but  he  probably  exaggerates  the  amount.  The  peculiar  sub- 
stance cafeine  contained  in  the  above  extract  is  crystallizable.  It  is  remarkable  in 
regard  to  composition,  that  after  urea  and  the  uric  acid,  it  is  among  organic  products 
the  richest  in  azote.  It  was  discovered  and  described  in  1820  by  Runge.  It  does  not 
possess  alkaline  properties.  Pfaff  obtained  only  90  grains  of  cafeine  from  six  pounds 
of  coffee  beans.  There  is  also  an  acid  in  raw  coffee,  to  which  the  name  of  ca/eic  acid 
has  been  given.    When  distilled  to  dryness  and  decomposed^  it  has  the  smell  of  roasted 

coffee.  nru  *    '  f^ 

Coffee  undergoes  important  changes  in  the  process  of  roasting.  When  it  is  roasiea 
to  a  yellowish  brown  it  loses,  according  to  Cadet,  12|  per  cent,  of  its  weight,  and  is  u 
this  state  difficult  to  grind.  When  roasted  to  a  chestnut  brown  it  loses  18  per  ceat., 
and  when  it  becomes  entirely  black,  though  not  at  all  carbonized,  it  has  lost  23  per  cent. 
Schrader  has  analyzed  roasted  coffee  comparatively  with  raw  coffee,  and  he  found  in 
the  first  12|  per  cent,  of  an  extract  of  coffee,  soluble  in  water  and  alcohol,  which  pos- 
sesses nearly  the  properties  of  the  extract  of  the  raw  coffee,  although  it  has  a  deeper 
iNTown  color,  and  softens  more  readily  in  the  air.  He  found  also  10*4  of  a  blackish 
brown  gum ;  5*7  of  an  oxygenated  extract,  or  rather  apotheme,  soluble  in  alcohol,  inso- 
luble in  water;  2  of  a  fatty  substance  and  resin;  69  of  burnt  vegetable  fibre,  insoluble. 
On  distilling  roasted  coffee  with  water,  Schrader  obtained  a  product  which  contained  the 
aromatic  principle  of  coffee ;  it  reddened  litmus  paper,  and  exhaled  a  strong  and  agree- 
able odor  of  roasted  coffee.  If  we  roast  coffee  in  a  retort,  the  first  portions  of  the  aro- 
matic principle  of  coffee  condense  into  a  yellow  liquid  in  the  receiver  ;  and  these  may  be 
added  to  the  coffee  roasted  in  the  common  way,  from  which  this  matter  has  been  expel- 
led and  dissipated  in  the  air. 

Chenevix  affirmed  that  by  the  roasting  of  coffee  a  certain  quantity  of  tannin  possessing 
the  property  of  precipitating  gelatin  is  generated.  Cadet  made  the  same  observation, 
and  found,  moreover,  that  the  tannin  was  most  abundant  in  the  lightly  roasted  coffee,  and 
that  there  was  nearly  none  of  it  in  coffee  highly  roasted.  Paysse  and  Schrader,  on  the 
contrary,  state  that  solution  of  gelatin  does  not  precipitate  either  the  decoction  of  roast- 
ed coffee  or  the  alcoholic  extract  of  this  coffee.  Runge  likewise  asserts  that  he  could 
obtain  no  precipitate  with  gelatin ;  but  he  says  that  albumen  precipitates  from  the  de- 
coction of  roasted  coffee  the  same  kind  of  tannin  as  is  precipitated  from  raw  coffee  by  the 
acetate  of  lead,  and  set  free  from  the  lead  by  siiphureted  hydrogen.  With  these  resulta 
my  own  experiments  agree.  Gelatin  certainly  Ices  not  disturb  clear  infusion  of  roasted 
coffee,  but  the  salts  o^  iron  blaeken  it. 

Schrader  endeavored  to  roast  separately  the  different  principles  of  coffee,  but  none  of 
them  exhaled  the  aromatic  odor  of  roasted  coffee  except  the  horny  fibrous  matter.  He 
therefore  concludes  that  this  substance  contributes  mainly  to  the  characteristic  taste  of 
roasted  coffee,  which  cannot  be  imitated  by  any  other  vegetable  matter,  and  which,  as  we 
have  seen,  should  be  ascribed  chiefly  to  the  altered  cafeic  acid.  Accordins  to  Garot,  we 
may  extract  the  cafeine  without  alteration  from  roasted  coffee  by  precipitating  its  decoc- 
tion by  subacetate  of  lead,  treating  the  washed  precipitate  with  sulphureted  hydrogen, 
and  evaporating  the  liquid  product  to  dryness. 

Of  late  years,  much  ingenuity  has  been  expended  in  contriving  various  forms  of  appa- 
ratus for  making  infusions  of  coffee  for  the  table.  I  have  tried  most  of  them,,  and  find, 
after  all,  none  so  good  as  a  cafetiere  a  la  Belloyj  the  coffee  Wggin,  with  the  perforated  tin- 
plate  strainer,  especially  when  the  filtered  liquor  is  kept  sivnmering  in  a  close  vessel,  set 
over  a  lamp  or  steam  pan.  The  useful  and  agreeable  matter  in  coffee  is  very  soluble  :  it 
comes  off  with  the  first  waters  of  infusion,  and  needs  no  boiling. 

To  roast  coffee  rightly  we  should  keep  in  view  the  proper  objects  of  this  process,  which 
are  to  develop  its  aroma,  and  destroy  its  toughness,  so  that  it  may  be  readily  ground  to 
powder.  Too  much  heat  destroys  those  principles  which  we  should  wish  to  preserve,  and 
substitutes  new  ones  which  have  nothing  in  common  with  the  first,  but  add  a  disagreea- 
ble empyreureatic  taste  and  smell.  If,  on  the  other  hand,  the  rawness  or  greenness  is 
not  removed  by  an  adequate  heat,  it  masks  the  flavor  of  the  bean,  and  injures  the  bev- 
erage made  with  it.  When  well  roasted  in  the  sheet-iron  cylinders  set  to  revolve  over  a 
fire,  it  should  have  a  uniform  chocolate  color,  a  point  readily  hit  by  experienced  roasters, 
who  now  manage  the  business  very  well  for  the  principal  coffee-dealers  both  of  Londoa 
and  Paris,  so  far  as  my  judgment  can  determine.    The  development  of  the  proper  aroma 


is  a  criterion  by  which  coffee  roasters  frequently^  regulate  their  operations^  When  it 
loses  more  than  20  per  cent  of  its  weight,  coffee  is  sure  to  be  injured.  It  should  never 
be  ground  till  immediately  before  infusion.  .     ,        .        ^  ^  i     • 

Liebig's  views  of  the  process  of  nutrition  have  given  fresh  interest  to  every  analysis 
of  articles  of  food.  A  watery  infusion  of  coffee  is  used  in  almost  every  country  as  a 
beveraee,  and  vet  it  is  uncertain  whether  it  is  an  article  of  nutrition  or  merely  a  con- 
diment A  minute  examination  of  the  raw  seed,  or  coffee  bean  as  it  is  called,  must 
precede  the  determination  of  that  disputed  point  Caffeine  is  the  principle  best  known, 
being  most  easily  separated  from  the  other  substances,  resisting  most  powerfully  chemi- 
cal reagents,  and  by  assuming  a  crystalline  state  is  discoverable  in  very  small  quan- 

^  The  constituente  of  coffee  are:  1.  Vegetable  Jihrine,  which  is  the  largest  constituent, 
being  an  elastic  horny  substance,  in  which  the  other  substances  are  incorporated.  If  we 
dry  the  beans  at  the  heat  of  boiling  water  for  several  weeks  we  can  easily  reduce  them 
to  a  fine  powder,  and  by  washing  with  ether,  and  then  boiling  in  alcohol  and  water  we 
extract  the  soluble  matter  from  the  fibrine,  which  may  then  be  boiled  with  weak  solution 
of  potash  and  afterwards  weak  muriatic  acid,  as  long  as  any  matter  is  taken  up.  Ihe 
purification  being  completed  by  boiling  in  water  the  fibrine  remains ;  and  when  rub- 
bed in  a  mortar  resembles  starch ;  when  roasted  it  gives  out  the  odor  neariy  of  ^ood. 
2  Fatty  matter:  the  beans  digested  in  ether  give  out  a  yellow-colored  matter,  vyhich 
on  evaporation  becomes  buttery  with  an  odor  of  raw  coffee,  and  amounts  to  lOg  of  the 

3.  Caffeine :  the  ethereal  solution  contains  caffeine,  which  may  be  removed  by  shaking 

with  a  solution  of  water.  ,     ,  ^.        .^.    xv.        -j 

4.  Legumine:  in  addition  to  an  acid  which  agrees  in  it«  properties  with  the  acid 
found  in  oak  and  cinchona,  we  find  in  the  coffee  beans  legumine  similar  to  that  of  beans. 
The  legumine  contains  sulphur,  which  is  the  cause  of  their  blackening  a  silver  vessel  in 
whichthe  beans  may  be  boiled  with  an  alkali.  Legumine  and  caffeine  are  the  only  ni- 
trogenous constituents  of  coffee  beans,  consequently  the  only  substances  which  could  be 
nuU-itious,  but  they  are  not  soluble  in  hot  water  as  they  exist  in  roasted  coffee,  and 
therefore  it  may  be  reckoned  merely  an  exhilarating  beverage. 

Roasted  coffee  affords  a  much  richer  infusion  to  hot  water  containing  a  minute  quan- 
tity  of  carbonate  of  soda,  and  improves  Uie  quality  of  coffee  on  the  stomach,  by  neu- 

'tralizing  the  caffeic  acids.  j  i-       i.  j     -au 

•    Coffee  is  sold  in  the  shops  in  ite  roasted  and  ground  state  often  adulterated  with  a 
variety  of  substances,  but  chiefly  with  chicory.     This  is  the  dried,  roasted,  and  ground 
root  of  a  plant  called  Cichoriwn  Intybun,  better  known  under  the  name  of  wild  succory. 
The  chicory  imported  from  Belgium  and  Prussia  is  better  than  the  British,  which  is 
usually  colored  with  Venetian  red,  and  is  sold  at  a  cheaper  rate ;  chicory  itself  is  fre- 
quently very  impure,  containing  roasted  peas  and  coffee  flighta,  which  are  the  mena- 
branous  coat  of  the  bean  separated  in  the  act  of  roasting.     If  a  little  genuine  ground 
coffee  be  thrown  in  a  wineglassfull  of  water,  it  mostly  floats,  and  slowly  moistens,  com- 
municating scarcely  any  color  to  the  liquid.     Powdered  chicory  treated  in  the  same 
way  very  speedily  absorbs  moisture,  communicates  a  deep  reddish  brown  tint  to  the 
water,  and  in  a  few  minutes  falls  to  the  bottom.     Hambro'  powder  contains  routed 
starch,  and  acquires  a  deep  purplish  color  when  moistened  with  a  solution  of  iodine. 
The  m'icroscope  shows  in  the  chicory  powder  fragments  of  dotted  ducts  which  do  not 
exist  in  coffee.     There  is  another  substance  which  is  mixed  with  coffee,  called  refining 
powder;  it  is  merely  caramel,  or  burnt  sugar.     It  is  used  /or  enabling  drained  coffee  to 
afford  a  dark  colored  infusion.  . 

If  tannin  exists  in  roasted  coffee,  as  maintained  long  ago  by  Chenevix,  and  generally 
admitted  since,  it  must  be  very  different  from  the  tannin  present  in  tea,  catechu,  kino, 
oak-bark,  willow-bark,  and  other  astringent  vegetables;  for  I  find  that  itjs  °ot,  like 
them,  precipitated  by  either  gelatine,  albumen,  or  sulphate  of  quinine.  With  regard 
to  the  action  upon  the  animal  economy  of  coffee,  tea,  and  cocoa,  which  contain  one 
common  chemical  principle  called  caffeine  or  theine,  Liebig  has  lately  advanced  some 
ingenious  views,  and  has,  in  particular,  endeavored  to  show  that,  to  persons  of  sedentary 
habits  in  the  present  refined  state  of  society,  they  afford  eminently  usdTul  beverage^ 
which  contribute  to  the  formation  of  the  characteristic  principle  of  bile.  This  important 
secreted  fluid,  deemed  by  Liebig  to  be  subservient  to  the  function  of  respiration, 
requires  for  ite  formation  much  azotised  matter,  and  that  in  a  state  of  coml.ination 
analogous  to  what  existe  in  caffeine.  The  quantity  of  this  principle  in  tea  and  coffee 
being  only  from  2  to  6  per  cent  might  lead  one  to  suppose  that  it  could  have  little  effect 
upon  the  system  even  of  regular  drinkers  of  their  infusions;  but  if  the  bile  contains  only 
one-tenth  of  solid  matter,  called  choleic  acid,  which  contains  less  than  4  per  cent  of 
azote  then  it  may  be  shown  that  3  grains  of  caffeine  would  impart  to  500  grams  of 


456 


COFFEE. 


COLLODION. 


457 


•  1 


I 


W-.* 

*  I 


)  *i 


■J 


bile  th«  uzote  which  occurs  in  that  crystalline  precipitate  of  bile  called  taurine,  which 
is  thrown  down  from  it  by  by  mineral  acids. 

One  atom  of  caffeine,  9  atoms  of  oxygen,  and  9  of  water,  being  placed  together, 
produce  the  composition  of  2  atoms  of  taurine.  Now  this  is  a  very  simple  combina- 
tion for  the  living  organism  to  eflFect;  one  already  paralleled  in  the  generation  of  hip- 
puric  acid  in  urine,  by  the  introduction  of  benzoic  acid  into  the  stomach ;  a  physiologi- 
cal discovery  made  by  my  son,  which  is  likely  to  lead  to  a  more  successful  treatment 
of  some  of  the  most  formidable  diseases  of  man,  particularly  gout  and  gravel. 

If  the  preceding  views  be  established,  they  will  justify  the  instinctive  love  of  mankind 
for  tea,  coffee,  and  cocoa,  in  spite  of  the  denunciations  and  veto  of  neuropathic,  homect' 
pathic,  and  hydropathic  doctors ;  sorry  pathologists — hoc  genua  omne.     See  Tea. 

In  the  years  ending  5th  January,  1851  and  1852,  the  imports  of  coffee  were  as  fol- 
lows : — 


Importations. 

Entries  for  Hoin« 
Conaumption. 

Gross  Amoant  of 
Duty. 

1851. 

1852. 

1851. 

18.52. 

1851. 

1852. 

Entered  before  15th  April  1851  • 

or  British  FosBesaions 

Foreigm 
Entered   from  15th  April,  1851: 

from  British  PoBeessiona 
out  of  Europe 

From  other  Parts 

36,814,036 
13,989,116 

•          • 

Ibt. 

1,818,514 
5,018,806 

34.077,563 
12,0a'i,269 

Ibi. 

28,891,294 
2,335,346 

*           * 

At. 

6,510*346 
443,418 

21,486,170 
4,124,230 

505,.515 
61,305 

113,981 
11,637 

268,599 
51,572 

50,803,152 

52,950,152 

31,226,840 

32,564,164 

566,820 

445,739 

The  duty  is  Zd  per  lb.  Tlie  exports  in  the  above  years  were  respectfully  12,169,762 
lbs.  and  22,712,859  lbs.  of  which  3,399,333  lbs.  and  12,606,333  lbs.  were  the  produce 
of  British  Possessions,  and  8,770,419  lbs.  and  10,106,526  lb&  were  Foreign. 

Coffee  Roasting  and  Grinding.  The  gratefulness  of  the  beverage  afforded  by  this 
seed  depends  upon  many  circumstances,  which  are  seldom  all  combined.    The  nature  of 

the  soil,  the  climate,  seed,  mode  of  culture, 
and  cure,  influence  greatly  the  quality  of 
the  fruit  But  when  all  these  particulars 
concur,  and  the  berry  is  of  the  finest  sort, 
and  most  highly  appreciated  by  the  im- 
porter, it  may  be  ruined  in  the  roasting ; 
for  if  some  berries  be  under  and  some 
over  done,  the  whole  when  ground  will 
yield  an  unpalatable  infusion.  The  due 
point  to  which  the  torrefaction  should  be 
carried,  may  be  determined  partly  by 
the  color,  and  partly  by  the  loss  of 
weight,  which  points,  however,  are  dif- 
ferent for  each  sort  of  coffee.  But  perfect 
equality  of  ustulation  is  difficult  of  attain- 
ment with  the  ordinary  cylindrical  ma- 
chines. Messrs.  Law,  of  London  and  Ed- 
inburgh, coffee  merchants  to  the  Queen, 
had  long  been  dissatisfied  with  the  partial 
manner  in  which  the  cylinder  performed 
its  duty,  as  it  generally  left  some  part  of 
its  contents  black,  some  dark  brown,  and 
others  paler ;  results  which  greatly  injure 
the  flavor  of  the  beverage  made  with  the 
coffee.  Mr.  William  Law  has  conquered 
all  these  difficulties  by  his  happy  invention  of  the  globular  roaster,  actuated  by  a  com- 
pound motion  like  that  of  our  earth.  This  roaster,  with  its  double,  rotary  motion,  is 
neated  not  over  an  open  fire  but  in  an  atmosphere  of  hot  air,  through  a  cast  metal  casing. 
The  globe  is  so  mounted  as  to  revolve  horizontally,  and  also  from  time  to  time  vertically, 
whereby  the  included  beans  were  tossed  about  and  intermingled  in  all  directions.  In- 
equality of  torrefaction  becomes  impossible.  The  consequence  is  the  production  of  an 
article  which  on  being  ground  evolves  the  most  fragrant  aroma,  and  when  infused  the 
most  grateful  and  exhilarating  beverage.     The  position  of  the  globe  in  Jig.  866  shows 


' 


it  as  turned  up  bv  a  powerful  leverage  out  of  the  cast-iron  heater,  preparatory  to  its 

being  emptied  and  re-charged.  .,i  i.  i.  v  -:»^^*-i  a*^«^ 

Tfe  coffee,  thus  equally  roasted,  is  finely  ground  in  a  mill  between  J^?"^««^^  «^"^^ 
like  that  of  a  corn-mill,  and  is  thereby  capable  of  giving  out  all  its  virtues  to  either 

boiling  or  cold  water.  ,  ^  ,  ,,         , 

COKE  is  carbonized  pitcoal.  See  Charcoal  ;  and  Pitcoal  at  the  end. 
In  manufacturing  coke  on  the  large  scale,  Mr.  Wilkinson  of  Jarrow.  near  Gates, 
head,  has  contrived  a  system  of  machinery  for  saving  manual  labor  in  discharging  the 
coke  from  the  ovens,  while  he  has  so  arranged  the  ovens  themselves,  as  to  equalize 
the  distribution  of  air  among  the  coals,  and  to  improve  the  produce  and  increase  ito 
quantity.  The  preferable  size  of  oven,  in  his  opinion,  is  14  feet  long,  8  feet  wide  with 
3ie  floor  raised  one  foot  above  the  level  of  the  ground,  and  having  an  inclination  to  the 
front  of  6  inches  in  the  length  of  the  bottom ;  the  perpendicular  height  of  the  wall^ 
up  U)  the  springer,  being  3  feet,  while  the  radius  of  the  arch  is  4  feet  He  connecte 
crystallizing  and  evaporating  pans  for  chemical  purposes  with  a  range  of  12  coke  ovens. 
The  patentee  claims  as  inventions  his  forming  in  the  walls  of  coke  ovens,  flues  with 
lateral  openings  for  supplying  air  to  the  interior  of  the  oven  as  also  his  peculiar 
mechanical  apparatus  for  discharging  the  coke,  and  his  plan  of  economizing  heat  by 

^^COLCOTHAR  OF  VITRIOL  {Rouge  d'Angleterre,  Fr.;  Bothes  Eisenoxgd,  Germ.) 
is  the  brown-red  peroxide  of  iron,  produced  by  calcining  sulphate  of  iron  with 
a  strong  heat,  levigating  the  resulting  mass,  and  elutriating  it  into  an  impalpable  pow- 
der. A  better  way  of  making  it  so  as  to  complete  the  separation  of  the  acid,  is  to  mix 
100  parts  of  the  green  sulphate  of  iron  with  42  of  common  salt  to  calcinethe  mixture, 
wash  away  the  resulting  sulphate  of  soda,  and  levigate  the  residuum.  The  sulphurw 
acid  in  this  case  expels  the  chlorine  of  the  salt  in  the  form  of  muriatic  acid  gas,  and 
saturates  its  alkaline  base  produced  by  the  chemical  reaction;  whence  an  oxide  willbe 
obtained  free  from  acid,  much  superior  to  what  is  commonly  found  m  the  shops.  Ihe 
best  sort  of  polishing  powder,  called  jeweller's  red  rouge,  or  plate  powder,  is  the  precipi- 
tated oxide  of  iron  prepared  by  adding  solution  of  soda  to  solution  of  copperas,  washing, 
drying,  and  calcining  the  powder  in  shallow  vessels  with  a  gentle  heat  UU  it  assumes 

a  deep  brown-red  color.     See  Iron.  ^        a  ^     xu     t?       v  -m  .4-  «i 

COLLODION.  M  Malgaigne  has  recently  communicated  to  the  l^rench  Medical 
Journals,  some  remarks  on  the  preparation  of  gun-cotton  for  surgical  purposea. 
Several  French  chemists,  at  the  suggestion  of  M  Malgaigne,  attempted  to  make  an 
ethereal  solution  of  this  compound,  by  pursuing  the  process  recommended  by  Mr. 
Mavnard  in  the  American  Journal  of  Medical  Sciences,  but  they  failed  in  procuring  the 
cotton  in  a  state  in  which  it  could  be  dissolved  in  ether.  It  appears  that  these  experi- 
mentalists had  employed  a  mixture  of  nitric  and  sulphuric  acids ;  but  M.  Miallie  ascer- 
tained, after  many  trials,  that  the  collodion,  in  a  state  fitted  for  solution,  was  much 
more  easily  procured  by  using  a  mixture  of  nitrate  of  potash  and  sulphuric  acid. 

For  the  information  of  our  readers  who  may  be  disposed  to  try  this  new  adhesive 
material,  we  here  give  a  description  of  M.  Miallie's  process  for  ite  preparation.     U 
appears  from  the  results  obtained  from  this  chemist  that  cotton,  in  its  most  explosive 
form,  is  not  the  best  fitted  for  making  the  ethereal  solution- 
Parts  by  weight. 
-     40 


Finely  powdered  nitrate  of  potash 
Concentrated  sulphuric  acid    - 
Carded  cotton 


-  60 

-  2 


Mix  the  nitrate  with  the  sulphuric  acid  in  a  porcelain  vessel,  then  add  the  cotton,  and 
agitate  the  mass  for  three  minutes  by  the  aid  of  two  glass  rods.  Wash  the  cotton,  with- 
out first  pressing  it,  in  a  large  quantity  of  water,  and  when  all  acidity  is  removed 
(indicated  by  litmus  paper)  press  it  firmly  in  a  cloth.     Pull  it  out  into  a  loose  mass,  and 


drv  it  in  a  stove  at  a  moderate  heat 


'  It  in  a  stove  ai  a  muuemi-c  iicov.  .. 

rhe  compound  thus  obtained  is  not  pure  fulminating  cotton ;  it  always  retains  a  small 
quantity  of  sulphuric  acid,  is  less  inflammable  than  gun-cotton,  and  it  leaves  a  carbo- 
naceous  residue  after  explosion.  It  has,  however,  in  a  remarkable  degree,  the  property 
of  solubility  in  ether,  especially  when  mixed  with  a  little  alcohol,  and  it  forms  there- 
with a  very  adhesive  solution,  to  which  the  name  of  collodion  has  been  applied. 


Preparation  of  Collodion. 


Prepared  cotton 
Rectified  sulphuric  ether 
Rectified  alcohol 


Parts  by  weight 
8 
-     125 
8 


Put  the  cotton  with  the  ether  into  a  well-stopped  bottle,  and  shake  the  mixture  lot 
some  minutes.     Then  add  the  alcohol  by  degrees,  and  continue  to  shake  until  the  whole 


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of  the  liquid  acquires  a  syrupy  consistency.  It  may  be  then  passed  through  a  cloth, 
the  residue  strongly  pressed,  and  the  liquid  kept  in  a  well-secured  bottle. 

Collodion  thus  prepared  possesses  remarkably  adhesive  properties.  A  piece  of  linen 
or  cotton  cloth  covered  with  it  and  made  to  adhere  by  evaporation  to  the  palm  of  the 
hand,  will  support  a  weiglit  of  twenty  or  thirty  pounds.  Its  adhesive  power  is  so  great 
that  the  cloth  will  commonly  be  torn  before  it  gives  way.  The  collodion  cannot  be 
regarded  as  a  perfect  solution  of  the  cotton.  It  contains  suspended  and  floating  in  it 
a  quantity  of  vegetable  fibre,  which  has  escaped  the  solvent  action  of  the  ether.  The 
liquid  portion  may  b^  separated  from  these  fibres  by  a  filter,  but  it  is  doubtful  whether 
this  is  an  advantage.  In  the  evaporation  of  the  liquid,  these  undissolved  fibres  by  felt- 
ing with  each  other  appear  to  give  a  greater  degree  of  tenacity  and  resistance  to  the 
dried  mass. 

In  the  preparation  of  collodion  it  is  indispensable  to  avoid  the  presence  of  water,  as 
this  renders  it  less  adhesive;  hence  the  ether  as  well  as  the  alcohol  should  be  purely 
rectified.  The  parts  to  which  the  collodion  is  applied  should  be  first  thoroughly  dried, 
and  no  water  allowed  to  come  in  contact  with  them  until  all  the  ether  is  evaporated 
to  dryness  by  a  steam  heat,  which  must  be  continued  for  some  time  so  as  entirely  to 
expel  the  alcohol  or  ether.  The  residuary  matter  shouldl  have  the  transparency  and 
general  characters  of  common  resin. 

COLOPHANY,  black  rosin,  the  solid  residuum  of  the  distillation  of  turpentine,  when 
aU  the  oil  has  been  worked  off. 

COLORING  MATTER.  (Matilre  colorante,  Fr. ;  Farbstoff,  Germ.)  See  Dyeing, 
the  several  dye-stuffs  and  pigments. 

COLUMBIUM,  a  peculiar  metal  extracted  from  a  rare  mineral  brought  from  Haddam, 
in  Connecticut.  It  is  also  called  Tantalium,  from  the  mineral  tantalitf.  and  yttro-tantaliUf 
found  in  Sweden.  It  has  hitherto  no  application  to  the  arts.  It  combines  with  two  suc- 
cessive dose?  of  oxygen ;  by  the  second  it  becomes  an  acid. 

COLZA  is  a  variety  of  cabbage,  the  hrassica  oleraceay  whose  seeds  afford,  by  pressure, 
an  oil  much  employed  in  France  and  Belgium  for  burning  in  lamps,  and  for  many  other 
purposes.  This  plant  requires  a  rich  but  light  soil ;  it  does  not  succeed  upon  either  sandy 
or  clayey  lands.  The  ground  for  it  must  be  deeply  ploughed  and  well  dunged.  It  should 
be  sown  in  July,  and  be  afterward  replanted  in  a  richly-manured  field.  In  October  it  ia 
to  be  planted  out  in  beds,  15  or  18  inches  apart.  Colza  may  also  be  sowed  in  furrows  3 
or  10  inches  asunder. 

Land  which  has  been  just  cropped  for  wheat  is  that  usually  destined  to  colza ;  it  may 
be  fresh  dunged  with  advantage.  The  harvest  takes  place  in  July,  with  the  sickle,  a 
little  before  the  seeds  are  completely  ripe,  lest  they  should  drop  off.  As  the  seed  is  pro- 
ductive of  oil,  however,  only  in  proportion  to  its  ripeness,  the  cut  plants  are  allowed  to 
complete  their  maturation,  by  laying  them  in  heaps  imder  airy  sheds,  or  placing  them  in 
a  stack,  and  thatching  it  with  straw. 

The  cabbage-stalks  are  thrashed  with  flails,  the  seeds  are  winnowed,  siAed,  spread  out 
in  the  air  to  dry ;  then  packed  away  in  sacks,  in  order  to  be  subjected  to  the  oil- mill  at 
the  beginning  of  winter.  The  oil-cake  is  a  very  agreeable  food  to  cattle,  and  serves  to 
fatten  them.     It  is  reckoned  to  defray  the  cost  of  the  mill. 

Colza  impoverishes  the  soil  very  much,  as  do,  indeed,  all  the  plants  cultivated  for  the 
lake  of  their  oleaginous  seeds.  It  must  not,  therefore,  be  come  back  upon  again  for  sii 
years,  if  fine  crops  be  desired.  The  double  ploughing  which  it  requires  effectuallj 
cleans  the  ground.    See  Oils,  Unctuous. 

COMB,  the  name  of  an  instrument  made  of  a  thin  plate  either  plane  or  curved  of  wood, 
horn,  tortoise-shell,  ivor}',  bone,  or  metal,  cut  out  upon  one  or  both  of  its  sides  or  edges, 
into  a  series  of  somewhat  long  teeth,  not  far  apart«;  which  is  employed  for  disentangling, 
laying  parallel  and  smooth  the  hairs  of  man,  horses,  or  other  animals. 

A  thin  steel  saw  bow,  mounted  in  an  iron  or  wooden  handle,  is  the  implement  used 
by  the  comb-maker  to  cut  the  bone,  ivory,  and  wood  into  slices  of  from  a  twelfth  to  a 
quarter  of  an  inch  thick,  and  of  a  size  suitable  to  that  of  the  comb.  The  pieces  of 
tortoise-shell  as  found  in  commerce  are  never  flat,  or,  indeed,  of  any  regular  curvature, 
such  as  the  comb  must  have.  They  are  therefore  steeped  in  boiling  water  sufiiciently 
long  to  soften  them,  and  set  to  cool  in  a  press  between  iron  or  brass  moulds,  which  im- 
part to  them  the  desired  form  which  they  preserve  after  cooling.  After  receiving  their 
outline  shape  and  curvature,  by  proper  flat  files  or  fine  rasps,  the  place  of  the  teeth  is 
marked  with  a  triangular  file,  and  then  the  teeth  themselves  are  cut  out  with  a  double 
saw,  composed  of  two  thin  slips  of  tempered  steel,  such  as  the  main-spring  of  a  watut, 
notched  with  very  fine  sharp  teeth.  These  slips  are  mounted  in  a  wooden  or  iron  stock 
or  handle,  in  which  they  may  be  placed  at  different  distances,  to  suit  the  width  of  the 
comb-teeth.  A  comb-maker,  however,  well  provided  in  tools,  has  an  assortment  of 
double  saws  set  at  every  ordinary  with.  The  two  slips  of  this  saw  have  their  teeth  in 
different  planes,  so  that  when  it  begins  to  cut,  the  most  prominent  slip  alone  acts,  and 


COMBUSTIBLE  SUGAR. 


461 


when  the  teeth  of  this  one  have  fairly  entered  into  the  comb,  the  other  parallel  blade 
begins  to  saw.  The  workman,  meanwhile,  has  fixed  the  plate  of  tortoise-shell  or  ivory 
between  the  flat  jaws  of  two  pieces  of  wood,  like  a  vice  made  fast  to  a  bench,  so  that 
the  comb  intended  to  be  cut  is  placed  at  an  angle  of  45'*  with  the  horizon.  He  now  saws 
perpendicularly,  forming  two  teeth  at  a  time,  proceeding  truly  in  the  direction  of  the  first 

tracinfir. 

A  much  better  mode  of  making  combs  is  to  fix  upon  a  shaft  or  arbor  in  a  lathe  a  se- 
ries  of  circular  saws,  with  intervening  brass  washers  or  discs  to  keep  them  at  suitable  dis- 
tances ;  to  set  in  a  frame  like  a  vice,  in  front  of  these  saws,  the  piece  of  ivory  or  horn  to 
be  cut ;  and  to  press  it  forward  upon  the  saws  at  an  angle  of  45  degrees,  by  means  of  a 
regulated  screw  motion.  When  the  teeth  are  thus  cut,  they  are  smoothed  and  polished 
with  files,  and  by  rubbing  with  pumice-stone  and  tripoli. 

Mr.  Bundy,  of  Camden  Town,  obtained  a  patent  so  long  ago  as  1796,  for  an  apparatus 
of  that  kind,  which  had  an  additional  arbor  fitted  with  a  series  of  circular  saws,  or  rather 
files,  for  sharpening  the  points  of  the  comb-teeth. 

More  recently,  Mr.  Lyne  has  invented  a  machine  in  which,  by  means  of  pressure,  two 
combs  are  cut  out  at  once  with  chisels  from  any  tough  material,  such  as  horn  or  tortoise- 
shell,  somewhat  softened  at  the  moment  by  the  application  of  a  heated  iron  to  it.  The 
piece  of  horn  is  made  fast  to  a  carriage,  which  is  moved  forward  by  means  of  a  screw 
until  it  comes  under  the  action  of  a  ratchet-wheel,  toothed  upon  a  part  of  its  circum- 
ference. The  teeth  of  this  wheel  bring  a  lever  into  action,  furnished  with  a  chisel  or 
knife,  which  cuts  out  a  double  comb  from  the  flat  piece,  the  teeth  of  which  combs  arc 
opposite  to  each  other.  By  this  means,  no  part  of  the  substance  is  lost,  as  in  sawing 
out  combs.  The  same  carriage  may  be  used,  also,  to  bear  a  piece  of  ivory  in  the  hard 
state  toward  a  circular  saw,  on  the  principles  above  explained,  with  such  precision,  that 
from  80  to  100  teeth  can  be  formed  in  the  space  of  one  inch  by  a  proper  disposition  of 

the  tool. 

Bullocks*  horns,  after  the  tips  are  sawed  off,  are  roasted  in  the  flame  of  a  wood  fire, 
till  they  are  sufficiently  softened ;  when  they  are  slit  up,  pressed  in  a  machine  between 
two  iron  plates,  and  then  plunged  into  a  trough  of  cold  water,  whereby  they  are  hard- 
ened.    A  paste  of  quicklime,  litharge,  and  water  is  used  to  stain  Uie  horn  to  resemble 

tortoise-shell.     See  Horn.  ,       .    ,  »•  ». 

COMBINATION  {Comhinaison,  Fr. ;  Verbindungy  Germ.) ;  a  chemical  term  whicl 
denotes  the  intimate  union  of  dissimilar  particles  of  matter,  into  a  homogeneous-look- 
ing compound,  possessed  of  properties  generally  different  from  those  of  the  separate 

constituents. 

COMBUSTIBLE  (Eng.  and  Fr. ;  Brennstoff,  Germ.)  ;  any  substance  which,  exposed  m 
the  air  to  a  certain  temperature,  consumes  spontaneously  with  the  emission  of  heal 
and  light.  All  such  combustibles  as  are  cheap  enough  for  common  use  go  under  the 
name  of  Fuel ;  which  see.  Every  combustible  requires  a  peculiar  pitch  of  temperatore 
to  be  kindled,  called  its  accendible  point.  Thus  phosphorus,  sulphur,  hydrogen,  carbu. 
reted  hydrogen,  carbon,  each  takes  fire  at  successively  higher  heats. 

COMBUSTIBLE  SUGAR  When  sugar  is  acted  on  by  a  mixture  of  nitric 
and  sulphuric  acids,  a  peculiar  substance  is  produced,  having  a  close  resemblance  to 
common  resin,  not  only  in  its  appearance  and  physical  characters,  but  also  in  regard  to 
its  solubility  in  alcohol,  ether,  volatile  oils,  Ac,  and  insolubility  in  water.  This  substance 
is,  however,  extremely  inflammable  and  explosive,  and  possesses  many  of  the  properties 
ascribed  to  the  celebrated  Greek  fire.  Its  afiinity  for  alcohol  and  ether  is  so  great  that 
water  will  not  remove  these  fluids  from  it  "Not  having  yet  succeeded  in  producing 
with  it  any  definite  basic  compound  which  would  enable  me  to  control  my  results,  J 
have  not  attempted  its  analysis.  The  only  purposes  to  which  I  have  applied  it  are  to 
the  formation  of  fusees  for  shells,  and  to  the  preservation  of  gunpowder  and  pyrotech- 
nical  articles  from  damp  and  moisture.  As  a  fusee,  it  ia  easily  lighted,  burns  with  great 
regularity,  and  appears  absolutely  incapable  of  being  extinguished,  circumstances  which 
would  render  it  of  great  use  in  ricochet  practice.  As  a  means  of  preventing  the  mis- 
chievous effect  of  damp  and  moisture  on  gunpowder  it  is  of  great  value.  The  best 
mode  of  application  is  to  plunge  the  gunpowder  for  a  few  seconds  into  an  alcoholic  or 
ethereal  solution  of  the  sugar  compound,  then  withdraw  it  and  allow  it  to  dry  at  a 
gentle  heat,  say  120°  Fahr.,  though  there  is  no  danger  of  an  explosion  at  212°.  In  this 
way  the  gunpowder  is  covered  by  a  coat  of  varnish  easy  of  ignition  and  insoluble  in 
water,  which  cannot  therefore  penetrate  to  the  gunpowder,  the  explosive  nature  of 
which  is  rather  augmented  than  diminished  by  this  treatment  An  ethereal  solution  of 
gun-cotton  does  not  answer  so  well  for  this  purpose,  nor  is  it  so  manageable.  I  have 
not  ascertained  how  far  this  new  substance  is  useful  in  retaining  the  edges  of  wounds 
in  approximation,  but  its  alcoholic  solution  merits  a  trial.  The  following  is  the  method 
which  I  have  found  most  successful  in  the  manufacture  of  this  compound : —  -  ..  . 
"Mix  together  sixteen  parts  of  concentrated  sulphuric  acid  and  eight  parts  of  nitnc 


462 


CONCRETE. 


COOLING  OF  FLUIDS. 


463 


acid,  gpec  grav.  1'50;  place  the  mixture  in  cold  water,  and  when  the  temperature  has 
fallen  to  60°  or  less,  stir  in  one  part  of  finely-powdered  sugar,  which  will  become  pasty 
m  a  few  seconds,  and  is  then  to  be  removed  and  plunged  in  cold  water,  when  more  sugar 
may  then  be  added  to  the  acid  mixture,  and  removed  as  before.  The  compound  is  to 
be  washed  in  water  and  dissolved  in  alcohol,  to  which  a  solution  of  carbonate  of  potash 
must  be  added  in  excess,  so  as  to  precipitate  the  substance,  and  neutralize  its  uncom- 
bined  acid.  After  careful  washing  with  water,  it  is  again  to  be  dissolved  in  alcohol  or 
ether,  and  cautiously  evaporated  to  dryness  by  a  steam  heat,  which  must  be  continued  for 
some  time,  so  as  entirely  to  expel  the  alcohol  or  ether.  The  residuary  matter  should 
have  the  transparency  and  general  character  of  common  rosin."— J/r.  i.  Thompson. 

COMBUSTION  (Eng.  and  Fr.;  Verbrennuna,  Germ.)  results  in  common  cases  from 
the  mutual  chemical  reaction  of  the  combustible,  and  the  oxygen  of  the  atmosphere, 
whereby  a  new  compound  is  formed ;  the  heat  and  light  evolved  being  most  probably 
produced  by  the  rapid  motions  of  the  particles  during  the  progress  of  this  combination. 

COMPOUND  COLORS.  If  the  effects  of  the  coloring  particles  did  not  vary  aceord- 
ing  to  the  combinations  which  thev  form,  and  the  actions  exercised  upon  them  by  the 
different  substances  present  in  a  dyeing  bath,  we  might  determine  with  precision  the 
§hade  which  ought  to  result  from  the  mixture  of  any  two  colors,  or  of  the  ingredients 
affording  these  colors  separately.  Though  the  chemical  action  of  the  mordants  and  of 
the  liquor  in  the  dye-bath  often  changes  the  result,  yet  theory  may  always  predict  thera 
within  a  certain  degree.  It  is  not  the  color  appropriate  to  the  dye-stuffs  which  is  to 
be  considered  as  the  constituent  part  of  compound  colors,  but  that  which  they  must 
assume  with  a  certain  mordant  and  dye-bath.  Our  attention  ought  therefore  to  be 
directed  principally  to  the  operation  of  the  chemical  agents  employed. 

1.  The  mixture  of  blue  and  yellow  dyes  produces  green.  D'Ambourney,  indeed, 
Mys  that  he  has  extracted  a  fast  green  from  the  fermented  juice  of  the  berries  of  the 
buckthorn  {rhamnu*  fragula),  but  no  dyer  would  trust  to  such  a  color. 

2.  The  mixture  of  red  and  blue  produces  violet^  purple,  columbine  (dove-color), 
pansy,  amaranth,  lilac,  mallow,  and  a  great  many  other  shades,  determined  by  the  na- 
ture and  tone  of  the  red  and  blue  dye-stuffs,  as  well  as  their  relative  proportions  in  the 
bath. 

3.  The  mixture  of  red  and  yellow  produces  orange,  mordore,  cinnamon,  coquelicoU 
brick,  capuchin;  with  the  addition  of  blue,  olives  of  various  shades ;  and  with  duna 
instead  of  yellows,  chestnut,  snuff,  musk,  and  other  tints. 

4.  Blacks  of  the  lighter  kinds  constitute  grays;  and,  mixed  with  other  colors,  pro- 
duce marrone  (marroons),  coffees,  damascenes.  For  further  details  upon  this  sub- 
jecti  see  Calico  Feinting,  Dyeing,  as  also  the  individual  colors  in  their  alphabetical 
plaees. 

CONCRETE.  The  name  given  by  architects  to  a  compact  mass  of  pebbles,  sand, 
»nd  lime  cemented  together,  in  order  to  form  the  foundations  of  buildings.  Semple 
lays  that  the  best  proportions  are  80  parts  of  pebbles,  each  about  7  or  8  ounces  in 
weight,  40  parts  sharp  river  sand,  and  10  of  good  lime ;  the  last  is  to  be  mixed  with 
water  to  a  thinnish  consistence,  and  grouted  in.  It  has  been  found  that  Thames  ballast, 
as  taken  from  the  bed  of  the  river,  consists  nearly  of  2  parts  of  pebbles  to  1  of  sand,  and 
therefore  answers  exceedingly  well  for  making  concrete ;  with  from  one  seventh  to  one 
eighth  part  of  lime.  The  best  mode  of  making  concrete,  according  to  Mr.  Godwin, 
is  to  mix  the  lime,  previously  ground,  with  the  ballast  in  a  dry  state ;  sufficient  water 
is  now  thrown  over  it  to  effect  a  perfect  mixture,  after  which  it  should  be  turned  over  at 
least  twice  with  shovels,  or  oftener;  then  put  into  barrows,  and  wheeled  away  for  use 
instantly.  It  is  generally  found  advisable  to  employ  two  sets  of  men  to  perform  (his 
operation, with  three  in  each  set;  one  man  to  fetch  the  water,  &.C.,  while  the  other  two 
turn  over  the  mixture  to  the  second  set,  and  they,  repeating  the  process,  turn  over  the 
concrete  to  the  barrow-men.  After  being  put  into  the  barrows,  it  should  at  once  be 
wheeled  up  planks,  so  raised  as  to  give  it  a  fall  of  some  yards,  and  thrown  into  the 
foundation,  by  which  means  the  particles  are  driven  closer  together,  and  greater  solidity 
is  given  to  the  whole  mass.  Soon  after  being  thrown  in,  the  mixture  is  observed  usually 
to  be  in  commotion,  and  much  heat  is  evolved  with  a  copious  emission  of  vapor. 
The  barrow-load  of  concrete  in  the  fall,  spreading  over  the  ground,  will  form  generally 
a  stratum  of  from  7  .x)  9  inches  thick,  which  should  be  allowed  to  set  before  throwing  in 
a  second. 

Another  method  of  making  concrete,  is  first  to  cover  the  foundation  with  a  certain 
quantity  of  water,  and  then  to  throw  in  the  dry  mixture  of  ballast  and  lime.  It  is  next 
turned  and  levelled  with  shovels ;  afler  which  more  water  is  pumped  in,  and  the  operation 
is  repeated.     The  former  method  is  undoubtedly  preferable. 

In  some  cases  it  has  been  found  necessary  to  mix  the  ingredients  in  a  pug-mill,  as  in 
mixing  clay,  &c.  for  bricks.  For  the  preparation  of  a  concrete  foundation,  as  the  harden- 
ing should  be  rapid,  no  more  water  should  be  used  than  is  absolutely  necessary  to  effect 


a  perfect  mixture  of  the  ingredients.  Hot  water  accelerates  the  induration.  There  is 
about  one  fifth  of  contraction  in  volume  in  the  concrete,  in  reference  to  the  bulk  of  ita 
ingredients.  To  form  a  cubical  yard  of  concrete,  about  30  feet  cube  of  ballast  and  S| 
feet  cube  of  ground  lime  must  be  employed,  with  a  sufficient  quantity  of  water. 

CONGELATION  (Eng.  and  Fr. ;  Ge/rierung,  Germ.);  the  act  of  freezing  liquids. 
Many  means  are  supplied  by  chemistry  for  effecting  or  promoting  this  process,  but  they 
do  not  constitute  any  peculiar  art  or  manufacture.     See  Ice-Housk. 

COOLING  OF  FLUIDS.  In  Mr.  Derosnes's  method,  the  cooling  agents  employed 
are  a  current  of  atmospheric  air,  and  warm  water  of  the  same  or  nearly  the  same  tem- 
perature as  that  of  the  vapors  which  are  to  be  operated  upon. 

Fig.  867  represents  merely  a  diagram  of  the  general  features  of  ftn  apparatus  con- 
ilructed  upon  the  principles  proposed  to  be  employed,  which  will  serve  to  explain  the 
nature  of  this  improvement. 

367  Let  A  be  the  source  of 

fK.  |]  the  vapors,  or  the  vessel, 

boiler,  alembic,  or  closed 
pan  that  contains  the 
liquid  or  sirup  to  be  eva- 
porated or  concentrated. 
The  pipe  b,  through  which 
the  vapor  passes  as  it 
rises  in  the  boiler,  is  sur- 
rounded by  another  tube 
c,of  larger  diameter,  closed 
at  both  ends.  A  pump  d, 
draws  from  the  reservoir  e, 
warm  water,  which  water 
has  been  heated  by  its  pre- 
vious and  continual  pas- 
sage through .  the  appa- 
ratus m  contact  with  the 
surface  of  the  vapor  pipes. 
This  pump  forces  the  water  by  the  pipe  f,  into  the  annular  space  or  chamber  between  the 
pipes  B  and  c,  in  which  chamber,  by  its  immediate  contact  with  the  pipe  b,  it  acquires  the 
temperature  of  the  vapors  intended  to  be  refrigerated.  The  pipe  g  conveys  th**  water  from 
the  pipe  c,  into  the  annular  colander  or  sieve  H,  which  has  a  multitude  of  ^iinall  holes 
pierced  through  its  under  part,  and  whence  the  warm  water  descends  in  the  form  of 
a  continued  shower  of  rain.  To  the  end  of  the  pipe  b,  a  distiller^s  worm  i  i,  is  connected, 
which  is  placed  beneath  the  colander  h.  The  entire  length  of  the  worm-pipe  should 
be  bound  round  with  linen  or  cotton  cloth,  as  a  conductor  of  the  heat,  which  cloth  will 
be  continually  moistened  by  the  rain  in  its  descent  from  the  colander.  As  this  water 
has  been  heated  in  passing  along  the  tube  c,  the  shower  of  rain  descending  from  the 
colander  will  be  at  a  higher  temperature  than  that  of  the  atmosphere,  and,  consequently, 
by  heating  the  surrounding  air  as  it  descends,  a  considerable  upward  draft  will  be 
produced  through  the  coils  of  the  worm-pipe. 

If  the  colander  and  the  worm-pipe  are  enclosed  within  a  chimney  or  upright  tube,  as 
K  Kj  open  at  top  and  bottom,  a  current  of  ascending  air  will  be  produced  within  it  by 
the  descending  shower  of  hot  water,  similar  in  effect  to  that  which  would  be  produced 
in  a  chimney  communicating  with  a  furnace,  or  to  that  of  the  burner  of  an  argana 
lamp.  Consequently,  it  will  be  perceived  that  in  opposition  to  the  descending  rain,  a 
strong  upward  current  of  air  will  blow  through  that  part  of  the  cylinder  k  k,  which  is 
beneath  the  colander.  When  the  air  first  enters  the  lower  aperture  of  the  chimney  oi 
tube  K,  it  is  of  the  same  temperature  and  moisture  as  the  external  atmosphere ;  but  in 
its  passage  up  the  tube  it  meets  with  a  warmer  and  damper  atmosphere,  caused  by  the 
heat  given  out  from  the  hot  fluid  continually  passing  through  the  pipes,  and  by  the  hot 
shower  of  rain,  and  also  by  the  steam  evolved  from  the  surfaces  of  the  coils  of  the  worm, 
which  are  continually  wetted  by  the  descending  rain,  the  evaporation  being  considerably 
augmented  by  th«  cloth  bound  round  the  worm-pipe,  retaining  the  water  as  it  descends  in 
drops  from  coil  t^  coil. 

The  atmosphere  within  the  tube  being  of  a  higher  temperature  than  without,  a 
current  of  air  constantly  ascends  and  escapes  at  the  upper  aperture  k,  and  its  place  is 
supplied  by  fresh  air  from  the  surroundin?  atmosphere,  entering  the  tube  below.  The 
fresh  air  thus  admitted  at  the  bottom  of  the  lube,  being  cold  and  dry,  will  be  suited  to 
take  up  the  heat  and  moisture  within,  because  the  water  within  the  tube,  being  in  a 
state  of  dispersion  as  rain,  presents  to  the  air  many  points,  or  a  very  extended  surface, 
an<{  also  because  it  is  of  a  higher  temperature  than  the  air ;  and,  besides,  cold  dry  air  is 
cow  inually  renewed,  and  a  source  of  warmth  is  furnished  by  the  latent  caloric  to  the 


464 


COOLING  OF  FLUIDS. 


COPAL. 


465 


iteara,  as  fast  as  it  is  evolved.  Thus  a  portion  of  the  descending  rain,  or  water,  ia 
evaporated,  and  the  effect  of  this  evaporation  is  to  abstract  caloric  not  only  from  the 
^ater  held  in  contact  with  the  coils  of  the  worm-pipe  by  the  cloth  enveloping  it,  but  also 
from  the  hot  vapors  which  pass  through  the  worm.  This  process  of  evaporation  has, 
therefore,  a  cooling  power,  which  is  but  slight  in  the  lower  part  of  the  chimney  or  tube 
K,  because  the  temperature  of  the  water,  or  rain,  and  of  the  worm,  at  this  part,  are  of 
a  lower  temperature;  but  its  refrigerating  power  increases  as  it  rises  towards  the 
colander,  and  there  it  acquires  its  maximum  of  intensity,  so  that  at  any  point  between 
the  lower  aperture  of  the  cylinder  and  the  colander  the  current  of  air  is  always  a  little 
cooler  than  the  atmosphere  of  the  region  through  which  it  passes  (that  is,  as  its  maxi- 
mum);  and  in  passing  this  region  of  higher  temperature,  it  is  not  only  put  in  equili- 
Dnum  of  temperature,  but  also  made  to  take  up  an  additional  quantity  of  aqueous  vapors, 
which  equalizes  the  new  temperature  it  acquires  with  its  capacity  of  saturation.  The 
cooling  caused  by  the  evaporation  acts  in  an  incessant  and  progressive  manner  from  the 
lower  aperture  of  the  cylinder  to  the  under  side  of  the  colander ;  and  this  cooling  not 
only  acts  as  an  agent  of  the  evaporation  which  the  current  of  air  cools,  but  it  refrige- 
rates also,  because  it  becomes  warmed  in  abstracting  caloric  from  the  vapors  or  liquidt 
passing  through  the  worm ;  and  this  refrigeration  acts  also  incessantly  and  progressively 
from  the  lower  part  of  the  tube  or  chimney  to  the  colander. 

The  patentee  states,  in  conclusion,  that  « the  velocity  or  force  of  the  current  of  air 
that  passes  through  the  chimney  or  tube  k,  can  be  accelerated  by  artificial  means,  either 
by  conducting  the  air  and  vapor  passing  from  the  upper  aperture  of  the  cylinder  into  the 
chimney  or  flues  of  a  furnace,  or  by  means  of  a  revolving,  forcing,  or  exhausting  fan,  or 
ventilator,  or  any  other  contrivance  which  will  produce  an  increased  current  of  air,  but 
which  is  not  necessary  to  be  particularly  described,  as  I  only  wish  to  explain  the  prin- 
ciples of  a  simple  apparatus,  constructed  in  any  convenient  form ;  and  I  would  remark, 
tkat  the  area  of  the  lower  aperture  through  which  the  air  is  introduced  into  the  chimney 
or  tube  k,  and  also  the  area  of  the  upper  aperture,  or  that  through  which  it  passes  to 
the  atmosphere,  should  be  in  accordance  with  the  effect  intended  to  be  obtained. 

"  It  is  further  to  be  remarked,  that  in  order  to  obtain  from  this  apparatus  the  best 
efl'ect,  the  velocity  of  the  current  of  air  must  be  itself  a  maximum ;  and  as  the  speed  or 
velocity  of  the  current  of  air  is  owing  to  and  determined  by  the  excess  of  the  tempe- 
rature of  the  descending  water,  or  rain,  and  of  the  coils  of  the  worm  to  that  of  the 
exterior  atmosphere,  it  ensues  that  the  temperature  of  the  water,  or  rain,  must  be  a 
maximum.  But  this  excess  of  temperature  is  a  maximum  only  when  the  source  of  the 
rain  is  at  the  same  temperature  as  the  vapors  to  be  condensed :  if  less  warm,  it  would 
attract  less  air ;  or,  if  warmer,  it  would  augment  the  temperature  of  the  vapors  intended 
to  be  condensed.  Consequently,  the  shower  of  water  employed  in  the  tube  k,  as  the 
agent  for  cooling,  bestows  its  maximum  of  effect  when  it  is  as  warm  as  the  vapors  to  be 
condensed ;  therefore,  I  may  express  this  proposition,  viz.,  <  That  in  refrigerating  with 
water,  less  of  it  may  be  expended  when  it  is  warm  than  when  it  is  cold,  and  that  the 
least  quantity  of  water  will  be  evaporated  when  it  is  as  warm  as  the  aqueous  or 
spirituous  vapors  upon  which  it  is  to  operate.' 

"  This  proposition  may  appear  strange,  nevertheless  it  is  conformable  to  the  laws  of 
nature ;  and  appears  only  strange,  because  until  now  warm  water  has  not  been  employed 
with  currents  of  air  for  refrigerating. 

"  Hence  it  is  necessary  to  raise  the  temperature  of  the  water  in  the  colander  to  the 
temperature  of  the  vapors  to  be  condensed :  therefore,  I  cause  the  lukewarm  water, 
pumped  from  the  reservoir  e,  to  circulate  in  the  chamber  c.  In  this  circulation  it  also 
begins  to  act  as  a  refrigerating  medium,  taking  up  a  portion  of  heat  from  the  vapors  that 
pass  through  the  pipe  b,  and  afterwards  it  acts  as  a  further  condenser  in  the  cylinder,  in 
the  way  described.  Finally,  the  portion  of  this  water  that  is  still  in  the  fluid  state,  after 
having  fallen  down  from  coil  to  coil,  arrives  lukewarm  to  the  inclined  surface  l,  which 
conducts  it  mto  the  reservoir  e,  from  whence  it  is  pumped  up  into  the  chamber  c,  as 
before  described. 

"The  tube  or  chimney  k  may  have  more  or  less  altitude;  the  higher  it  is  the  greater 
IS  the  current  produced.  The  force  or  velocity  of  the  current  of  air  can  be  governed  by 
the  areas  of  the  introduction  and  exit  apertures.  If  the  cylinder  rises  only  to  the  height 
of  the  sieve,  the  effect  is  much  less  than  when  it  is  prolonsed  beyond  this  height.  I 
would  further  remark,  that  if  the  cylinder  was  removed,  a  slight  effect  mi?ht  be  pro- 
duced, provided  that  a  current  of  air  be  preserved  in  the  cylindrical  space  limited  by  the 
toils  of  the  worm,  and  also  if  the  current  was  produced  between  the  coils ;  or  a  central 
passa^re  might  be  formed  in  an  apparatus  of  another  shape  than  that  above  described. 

"  I  have  only  shown  the  application  of  the  worm,  because  intending  only  to  explain 
the  principles  of  this  method  of  condensing  and  refrigerating. 

«  The  small  quantity  of  water  wasted  in  this  manner  of  condensation,  (that  is,  that 
portion  passed  off  to  the  atmosphere  in  the  form  of  vapors,  at  the  upper  aperture  of  the 


cylinder  k),  may  be  replaced  by  a  small  stream  of  cold  water,  which  may  be  brought 
to  the  apparatus,  and  perhaps  most  conveniently  introduced  into  the  reservoir  k,  or  into 
the  chamber  between  the  pipes  b  and  a  When  operating  upon  aqueous  \napor8,  the 
waste  of  waters  is  always  less  in  weight  than  that  of  the  vapors  liquefied.  When  this 
apparatus  is  applied  to  the  purposes  of  distillation,  the  end  of  the  worm  should  termi- 
nate in  a  vessel  m,  which  is  to  receive  the  produce  of  the  condensation.  It  will  be  seen 
that  this  improved  process  is  applicable  to  various  purposes,  where  condensation  or 
refrigeration  is  required;  for  instance,  in  the  boiling  or  concentration  of  sugar;  to  con- 
densing and  refrigerating  distilled  vapors,  or  steam,  or  saline  liquids,  either  in  vacuum 
or  not ;  to  cooling  brewers'  worts ;  and  to  the  refrigeration  of  other  liquors,  or  any  other 
processes,  when  it  may  be  required." 

I  have  inserted  the  specification  of  this  patent  verbatim.  M.  Derosne  has  busied  him- 
self during  a  long  life  with  a  prodigious  number  of  ingenious  little  contrivances  for 
clarifying  and  boiling  syrups,  distillation,  &c.,  but  he  has  in  this  invention  taken  a 
bolder  flight,  having  secured  the  exclusive  privilege  of  condensing  vapors,  and  cooling 
liquors,  with  hot  water,  in  preference  to  cold.  Ko  man  at  all  versant  in  the  scientific 
doctrines,  or  the  practical  applications  of  caloric,  will  ever  seek  to  meddle  with  his  mo- 
nopoly of  such  a  scheme.  He  may  find,  perhaps,  some  needy  coppersmith  ready  to 
espouse  that  or  any  other  equally  foolish  project,  provided  a  productive  job  can  be 
made  of  it,  against  credulous  customers. 

For  some  rational  methods  of  cooling  liquors  and  condensing  vapors,  see  Refrigeea- 
TiON,  Still,  and  Sugar. 

COPAL,  a  resin  which  exudes  spontaneously  from  two  trees,  the  Ithtts  copallinum^ 
and  the  Elaocarpus  copali/er,  the  first  of  which  grows  in  America,  and  the  second  in  the 
East  Indies.  A  third  species  of  copal-tree  grows  on  the  coasts  of  Guinea,  especially  on 
the  banks  of  some  rivers,  among  whose  sands  the  reein  is  found.  It  occurs  in  lumps  of 
various  sizes  and  of  various  shades  of  color,  from  the  palest  greenish  yellow  to  darkish 
brown.  I  found  its  specific  gravity  to  vary  in  different  specimens  from  1-059  to  1-071, 
being  intermediate  in  density  belween  its  two  kindred  resins,  anim6  and  amber.  Some 
rate  its  specific  gravity  so  high  as  1-139,  which  I  should  think  one  of  the  errors  with 
which  chemical  compilations  teem.  Copal  is  too  hard  to  be  scratched  by  the  nail, 
whence  the  excellence  of  its  varnish.  It  has  a  conchoidal  fracture,  and  is  without  smell 
or  taste.  When  exposed  to  heat  in  a  glass  retort  over  a  spirit  lamp,  it  readily  melts 
into  a  liquid,  which  being  further  heated  boils  with  explosive  jets.  A  viscid,  oily-looking 
matter  then  distils  over.  After  continuing  the  process  for  some  time,  no  succinic  acid 
is  found  in  the  receiver,  but  the  copal  blackens  in  the  retort.  Anhydrous  alcohol 
boiled  upon  it  causes  it  to  swell,  and  transforms  it  by  degrees  into  an  elastic,  viscid 
substance.  It  is  not  soluble  in  alcohol  of  0825  at  the  boiling  point,  as  I  have  ascer- 
tained. Copal  dissolves  in  ether,  and  this  ethereous  solution  may  be  mixed  with  alco- 
hol without  d€composition.  Caoutchoucine  acts  very  slightly  upon  it  by  my  experi- 
ments, even  at  the  boiling  temperature  of  this  very  volatile  fluid ;  but  a  mixture  of  it 
with  alcohol  of  0*825,  in  equal  parts,  dissolves  it  very  rapidly  in  the  cold  into  a  perfectly 
liquid  varnish.  Alcohol  holding  camphor  in  solution  also  dissolves  it,  but  not  nearly  so 
well  as  the  last  solvent  According  to  Unverdorben,  copal  may  be  completely  dissolved 
by  digesting  one  part  of  it  for  24  hours  with  one  part  and  a  half  of  alcohol  (probably  an- 
hydrous), because  that  portion  of  copal  which  is  insoluble  in  alcohol  dissolves  in  a  very 
concentrated  solution  of  the  soluble  portion.  Oil  of  petroleum  and  turpentine  dissolve 
only  1  or  2  per  cent  of  raw  copal.  By  particular  management,  indeed,  oil  of  turpentine 
may  be  combined  with  copal,  as  we  shall  describe  under  the  article  Varnish. 

Fused  copal  possesses  different  properties  from  the  substance  in  its  solid  state;  for  it 
then  may  be  made  to  combine  both  with  alcohol  and  oil  of  turpentine. 

Unverdorben  has  extracted  from  the  copal  of  Africa  five  different  kinds  of  resin,  none 
of  which  has,  however,  been  applied  to  any  use  in  the  arte. 

The  ultimate  constituents  of  copal  by  my  analysis  are,  carbon  Y9*8Y,  hydrogen  9-00, 
oxygen  ll'l;  being  of  hydrogen  7-6  in  excess  above  the  quantity  necessary  to  form 
water  with  the  oxygen. 

Much  information  has  been  received  from  various  sources  concerning  this  somewhat 
ill-understood  product  of  late  years.  It  is  now  known  that  there  are  three  different 
kinds  of  copal  in  commerce,  but  nothing  is  known  of  their  distinguishing  characteristics. 
We  have  East  Indian  and  West  Indian  copal,  and,  under  the  latter  name,  two  very  dif- 
ferent substances  The  East  Indian,  called  also  African,  is  more  colorless,  soft,  and  trans- 
parent, than  the  others;  it  forms  a  fine  surface,  and  when  heated  emits  an  agreeable 
odor.  It  furnishes  the  finest  varnish.  Fresh  essence  of  turpentine  dissolves  it  com- 
pletely, but  not  old.  Essence  digested  upon  sulphur  will  dissolve  double  its  own  weight, 
without  letting  any  fall.  Fresh  rectified  oil  of  rosemary  will  dissolve  it  in  any  propor- 
tion, but  if  the  oil  is  thickened  by  age  it  serves  only  to  swell  this  copaL 

30 


466 


COPPER. 


COPPER. 


467 


When  cautiously  melted,  it  may  be  then  dissolved  in  good  esaencc  of  turpentine  in 
any  proportion,  producing  a  fine  varnish,  of  little  color. 

A  good  varnish  may  be  made  by  dissolving  1  part  of  copal,  1  of  essence  of  rosemary, 
"with  from  2  to  3  of  pure  alcohol  This  varnish  should  be  applied  hot,  and  when  eold 
becomes  very  hard  and  durable. 

The  West  India  species,  or  American,  comes  to  us,  not  in  lumps  of  a  globular  form, 
but  in  small  flat  fragments,  which  are  hard,  rough,  and  without  taste  or  smelL  It  ia 
usually  yellow,  and  never  colorless"^  like  the  other.  Insects  are  very  rarely  found  in  it 
It  comes  from  the  Antilles,  Mexico,  and  North  America.  It  will  not  dissolve  in  essence 
of  rosemary. 

The  third  kind  of  copal,  known  also  as  West  Indian,  was  formerly  sold  as  a  product 
of  the  East  Indies.  It  is  found  in  fragments  of  a  concavo-convex  form,  the  outer  cover- 
ing of  which  appears  to  have  been  removed.  It  contains  many  insecta  When  rubbed 
it  emits  an  aromatic  odor.  It  gives  out  much  ethereous  and  empyreumatic  oil  when 
melted.     It  forms  a  soft  varnish,  which  dries  slowly. 

Fusel  oil,  or  amyle  spirit,  has  been  lately  used  as  a  solvent  of  the  hard  copal ;  but  it 
does  not  dry  into  a  very  solid  varnish. 

Annexed  is  an  account  of  the  import  of  anim4  and  copal,  in  the  undermentioned 
years : — 

1841.  1842.  184a  1844. 

Quantities  imported            cwta               —  8336  8359  6493 

Quantities  exported            cwts.               —  1403  1508  2461 

Retained  for  consumption  cwts.               —  2091  2085  2770 

Nett  revenue                              £              536  296  117  167 

COPPER  is  one  of  the  metals  most  anciently  known.  It  was  named  from  the  inland 
of  Cyprus,  where  it  was  extensively  mined  and  smelted  by  the  Greeks.  It  has  a  red- 
dish brown  color  inclining  to  yellow :  a  faint  but  nauseous  and  rather  disagreeable 
taste ;  and  when  rubbed  between  the  fingers  it  imparts  a  smell  somewhat  analogous  to 
its  taste.  Its  specific  gravity  is  from  8*8  to  8*9.  It  is  much  more  malleable  than  it  ia 
ductile ;  so  that  far  finer  leaves  may  be  obtained  from  it  than  wire.  It  melts  at  the 
27th  degree  of  Wedgewood's  pyrometer,  and  at  a  higher  temperature  it  evaporates  in 
fumes  which  tinge  the  flame  of  a  bluish  green.  By  exposure  to  heat  with  access  of  air, 
it  is  rapidly  converted  into  black  scales  of  peroxide.  In  tenacity  it  yields  to  iron;  but 
surpasses  gold,  silver,  and  platinum,  considerably  in  this  respect 

In  mineralogy,  the  genus  copper  includes  about  13  different  species,  and  each  of  these 
contains  a  great  many  varieties.  These  ores  do  not  possess  any  one  general  exterior 
character  by  which  they  can  be  recognised ;  but  they  are  readily  distinguished  by  chem- 
ical re-agents.  Water  of  ammonia  digested  upon  any  of  the  cupreous  ore  in  a  pulver- 
ized state,  after  they  have  been  calcined  either  alone  or  with  nitre,  assumes  an  mtense 
blue  color,  indicative  of  copper.  The  richest  of  the  ordinary  ores  appear  under  two 
aspects:  the  first  class  has  a  metallic  lustre,  a  copper  red,  brass  yellow,  iron  gray,  or 
blackish  gray  color,  sometimes  inclining  to  blue  ;  the  second  is  without  metallic  appear- 
ance, has  a  red  color,  verging  upon  purple,  blue,  or  green,  the  last  tint  being  the  most 
usual  Few  copper  ores  are  to  be  met  with,  indeed,  which  do  not  betray  the  presence 
of  this  metal  by  more  or  less  of  a  greenish  film. 

Dr.  Scherer,  of  Freybei^,  has  arranged  the  ores  of  copper  as  follows : — 


Symbol. 

1.  Copperglanz  (Kupferglaserz)  CuaS 

2.  Kupferkies,  Copper  pyrites,  Cu^,  FcaSs 

3.  Buntkupfererz  3  Cu^,  FeSs 

4.  Fahlerz  4  (CujS,  FeS,  ZnS,  AgS  (Sb  Ss  As  S,) 

5.  Rothkupfererz  CujO 

6.  Malachit  2  CuO,  COj-f-HO 

7.  Kupferlasur  (2  (CuO,  C02)-}-CuO.  HO 


Copper  in  lOOL 

79-7 
84-8 
56-7 
14—41 
88-5 
57-4 
65-8 


Both  Fahlerz  and  Buntkupfererz  vary  greatly  in  their  proportion  of  copper.  Fablers 
is  very  difficult  to  convert  into  pure  copper  by  smelting,  on  account  of  tne  presence  of 
antimony  and  arsenic  in  it  Kupferglanz  is  a  disulphuret  of  copper.  Buntiupfererz  is 
purple  or  variegated  copper  ore.  Rothkupfererz  is  the  orange  or  red  oxide  of  copper. 
Kuferlasur  is  blue  carbonate  of  copper. 

Pure  copper  majr  be  obtained  in  the  solid  state  either  by  the  reduction  of  the  pow- 
der of  the  pure  oxide  by  a  stream  of  hydrc^en  gas  passed  over  it  in  an  ignited' tube,  or 
by  the  galvanoplastic  process.     See  Electro-metallurgy,  or  Electrottpie. 

1.  Native  Copper  occurs  in  crystals,  branches,  and  filaments,  its  most  common  lo- 
cality bein^  in  primitive  rocks.  It  is  found  abundantly  in  Siberia,  at  the  mines  of 
Tourinski,  m  those  of  Hungary,  of  Fundo-Moldavi  in  Gallicia,  of  Fahlun  in  Sweden. 


of  Cornwall,  &«.  The  gangues  of  native  copper  are  granite,  gneiss,  mica-slate,  clay 
slate,  quartz,  carbonate  or  fiuate  of  lime,  sulphate  of  barytes,  &c.  The  most  remarka- 
ble masses  of  native  copper  hitherto  observed  were — first,  one  in  Brazil,  14  leasues  from 
Basa,  which  weighed  2616  pounds;  and  secondly,  another  which  Dr.  Francis-le-Baron 
discovered  in  America  to  the  south  of  Lake  Superior.  It  was  nearly  15  feel  in  circum- 
ference. 

2.  Sulphuret  of  Copper^  the  vitreous  ore  of  Brochani.  The  texture  of  this  ore  is  conv- 
pict;  its  fracture,  conchoidal,  surface  sometimes  dull ;  color,  iron  black  or  lead  gray,  often 
bluish,  iridiscent,  or  reddish  from  a  mixture  of  protoxyde.  It  is  easily  melted  even  by 
the  heat  of  a  candle ;  but  more  difficult  of  reduction  than  protoxyde.  This  ore  yields  to 
the  knife,  assuming  a  metallic  lustre  when  cut.  Its  density  varies  from  4*8  to  5*34.  Its 
composition,  according  to  Klaproth,  is  78*5  copper,  18*5  sulphur,  with  a  little  iron  and 
silica.  Its  equivalent  constitution  by  theory  is  80  copper -[-20  sulphur  =  100;  whence 
78-5  of  metal  should  be  associated  with  19-6  of  sulphur.  This  ore  is  therefore  one  of 
the  richest  ores,  and  forms  very  powerful  veins,  which  likewise  contain  some  orange  pro- 
toxyde. It  is  to  be  found  in  all  considerable  copper  districts ;  in  Siberia,  Saxony,  Sweden, 
and  especially  Cornwall,  where  the  finest  crystals  occur. 

3.  Copper  Pyrites  resembles  in  its  metallic  yellow  hue,  sulphuret  of  iron ;  but  the  latter 
is  less  pale,  harder,  and  strikes  fire  more  easily  with  steel.  It  presents  the  most  lively 
rainbow  colors.  Its  specific  gravity  is  4*3.  It  contains  generally  a  good  deal  of  iron, 
as  the  following  analysis  will  show :  copper  30,  sulphur  37,  iron  33,  in  100  parts.  Ac- 
cordmg  to  Hisinger,  the  Swedish  pyrites  contains  63  of  copper,  12  of  iron,  and  25  of  sul- 
phur. These  ores  occur  in  primitive  and  transition  districts  in  vast  masses  and  powerful 
veins ;  and  are  commonly  accompanied  with  gray  copper,  sulphuret  of  iron,  sparry  iron, 
fiulphurets  of  lead,  and  zinc. 

4.  Gray  Copper  has  a  steel  gray  color,  more  or  less  deep,  either  shining  or  dull ;  frac- 
ture uneven;  a  distinct  metallic  lustre;  diflicult  of  fusion  at  the  blowpipe ;  it  communi- 
cates to  glass  of  borax  a  yellowish-red  color.  Its  density  in  crystals  is  4*86.  Its  compo- 
sition is  very  variable ;  consistins  essentially  of  copper,  iron,  antimony,  and  sulphur.  The 
exploration  of  this  ore  is  profitable,  in  consequence  of  the  silver  which  it  frequently  con- 
tains. It  occurs  in  primitive  mountains ;  and  is  oAen  accompanied  with  red  silver  ore^ 
copper  pyrites,  and  crystallized  quartz. 

5.  Protoxyde  of  Copper,  or  red  oxyde  of  Copper :  its  color  is  a  deep  red,  sometimes 
very  lively,  especially  when  bruised.  It  is  friable,  difficult  of  fusion  at  the  blowpipe,  re- 
ducible on  burning  charcoal,  soluble  with  efiervescence  in  nitric  acid,  forming  a  green 
liquid.     Its  constitution,  when  pure,  is  88*9  copper -|-  11*1  oxygen  =  100. 

6.  Black  oxyde  of  Copper  is  of  a  velvet  black,  inclining  sometimes  to  brown  or  blue ; 
and  it  acquires  the  metallic  lustre  on  being  rubbed.  It  is  infusible  at  the  blowpipe.  Its 
composition  is,  copper  80 -(-oxygen  20  ;  being  a  true  peroxyde. 

7.  Hydrosilicate  of  Copper  consists  essentially  of  oxyde  of  copper,  silica,  and  water. 
Its  color  is  green ;  and  its  fracture  is  conchoidal  with  a  resinous  lustre,  like  most  minerals 
which  contain  water.  Its  specific  gravity  is  2*73.  It  is  infusible  at  the  blowpipe  alone, 
but  it  melts  easily  with  borax. 

8.  Dioptase  Copper,  or  Emerald  Malachite ;  a  beautiful  but  rare  cupreous  mineral,  con- 
sisting of  oxyde  of  copper,  carbonate  of  lime,  silica,  and  water  in  varying  proportions. 

9.  Carbonate  of  Copper,  Malachite,  is  of  a  blue  or  green  color.  It  occurs  often  in 
beautiful  crystals. 

10.  Sulphate  of  Copper,  Blue  Vitriol,  similar  to  the  artificial  salt  of  the  laboratory 
The  blue  water  which  flows  from  certain  copper  mines  is  a  solution  of  this  salt.     The 
copper  is  easily  procured  in  the  metallic  state  by  plunging  pieces  of  iron  into  it. 

11.  Phosphate  of  Copper  is  of  an  emerald  green,  or  verdigris  color,  with  some  spots  of 
black.  It  presents  fibrous  or  tuberculous  masses  with  a  silky  lustre  in  the  fracture.  It 
dissolves  in  nitric  acid  without  eflTervescence,  forming  a  blue  liquid ;  melts  at  the  blow- 
pipe, and  is  reducible  upon  charcoal,  with  the  aid  of  a  little  grease,  into  a  metallic  globule. 
Its  powder  does  not  color  flame  green,  like  the  powder  of  muriate  of  copper. 

12.  Muriate  of  Copper  is  green  of  various  shades;  its  powder  imparts  to  flame  a  re- 
markable blue  and  green  color.  It  dissolves  in  nitric  acid  without  eflTervescence-;  and  is 
easily  reduced  before  the  blowpipe.  Its  density  is  3*5.  By  Klaprolh's  analysis,  it  con- 
tisis  of  oxyde  of  copper  73,  muriatic  acid  10,  water  17. 

13.  ^rseniate  of  Copper.  It  occurs  in  beautiful  blue  crystals.  Before  the  blowpipe  it 
melts,  exhaling  fumes  of  a  garlic  odor,  and  it  affords  metallic  globules  when  in  contact 
with  charcoal.     See  mere  upon  the  ores  at  the  end  of  this  article. 

In  the  article  Metallurgy,  I  have  described  the  mode  of  working  certain  coppei 
mines ;  and  shall  content  myself  here  with  giving  a  brief  account  of  two  cupreous  forma- 
tions, interesting  in  a  geological  point  of  view ;  that  of  the  copper  slate  of  Mansfeldt,  and 
•f  the  copper  veins  of  Cornwall. 

The  curious  strata  of  bituminous  schist  in  the  first  of  these  localities,  art  among  tht 


I    ' 


468 


COPPER. 


I 


most  ancient  of  any  which  contain  the  exuviae  of  organized  bodies  not  testaceom.  "From 
among  their  tabular  slabs  the  vast  multitudes  of  fossil  fish  were  extracted,  which  have 
rendered  the  cantons  of  Mansfeldt,  Eisleben,  Ilmenau,  and  other  places  in  Thuringia  and 
Voigtland  so  celebrated.  Many  of  the  fish  are  transformed  into  copper  pyrites.  Here, 
also,  have  been  found  the  fossil  remains  of  the  lizard  family,  called  Monitors. 

Such  is  the  influence  of  a  wise  administration  upon  the  prosperity  of  mines,  that  the 
thin  layer  of  slate  m  this  formation,  of  which  100  pounds  commonly  contain  but  one 
pound  and  a  half  of  copper,  occasionally  argentiferous,  has  been  for  several  centuries  the 
object  of  smelting  works  of  the  greatest  importance  to  the  territory  of  Mansfeldt  and  the 
adjoining  country. 

The  frequent  derangements  which  this  metallic  deposite  experiences,  led  skilful  directors 
of  the  under-ground  operations  at  an  early  period  to  study  the  order  of  superposition  ol 
the  accompanying  rocks.  From  their  observations,  there  resulted  a  system  of  facts  whicH 
have  served  to  guide  miners,  not  only  in  the  country  of  Man«,''°ldt,  but  over  a  great  poi 
tion  of  Germany,  and  in  several  other  countries  where  the  sam«  series  of  rocks,  forming 
the  immediate  envelope  of  the  cupreous  schists,  were  found  to  occur  in  the  same  ordei 
of  superposition. 

0/  the  English  copper  works. — ^The  deposites  of  copper  in  Cornwall  occur  always  IJ 
Teins  in  granite,  or  in  the  schistose  rocks  which  surround  and  cover  it ;  and  hence,  the 
Cornish  miners  work  mostly  in  the  granite  or  greenish  clay  slate ;  the  former  of  which 
they  call  growan,  the  latter  killas.  But  tin  is  sometimes  disseminated  in  small  veins  in 
porphyry  or  elvauy  which  itself  forms  great  veins  in  the  above  rocks.  No  stratification 
has  been  observed  in  Cornwall. 

The  copper  veins  are  abundant  in  the  killas  and  rare  in  the  granite ;  but  most  numer- 
ous near  the  line  of  junction  of  the  two  rocks.  The  different  kinds  of  mineral  veins  in 
Cornwall  may  be  classed  as  follows  : — 

1.  Veins  of  elvan ;  el  van  courses,  or  elvan  channels. 

2.  Tin  veins,  or  tin  lodes  ;  the  latter  word  being  used  by  the  Cornish  miners  to  signify 
a  vein  rich  in  ore,  and  the  word  course,  to  signify  a  barren  vein. 

3.  Copper  veins  running  east  and  west ;  east  and  west  copper  lodes. 

4.  Second  system  of  copper  veins,  or  contra  copper  lodes. 

5.  Crossing  veins  ;  cross  courses. 

6.  Modem  copper  veins ;  more  recent  copper  lodes. 

7.  Clay  veins ;  of  which  there  are  two  sets,  the  more  ancient,  called  Cross-Fluckans  ; 
and  the  more  modem,  called  Slides, 

There  are  therefore  three  systems  of  copper  veins  in  Cornwall ;  of  which  the  first  is 
considered  to  be  the  most  ancient,  because  it  is  always  traversed  by  the  two  others,  and 
because,  on  the  contrary,  it  never  cuts  them  off.  The  width  of  these  veins  does  not  ex- 
ceed 6  feet,  though  occasional  enlargements  to  the  extent  of  12  feet  sometimes  take  place. 
Their  length  is  unknown,  but  the  one  explored  in  the  United  Mines  has  been  traced  over 
an  extent  of  seven  miles.  The  gangue  of  these  veins  is  generaUy  quartz,  either  pure,  or 
mixed  with  green  particles  analogous  to  chlorite.  They  contain  iron  pyrites,  blende,  sul- 
phuret,  and  several  other  compounds  of  copper,  such  as  the  carbonate,  phosphate,  arse- 
niate,  muriate,  &c.  The  most  part  of  the  copper  veins  are  accompanied  with  small  ar- 
gillaceous veins,  called  by  the  miners  fluckan  of  the  lode.  These  are  often  found  upon 
both  sides  of  the  vein,  so  as  to  form  cheeks  or  salebandes. 

When  two  veins  intersect  each  other,  the  direction  of  the  one  thrown  out  becomes  an 
object  of  interest  to  the  miner  and  geologist.  In  Saxony  it  is  regarded  as  a  general  fact 
that  the  rejected  portion  is  always  to  the  side  of  the  obtuse  angle ;  this  also  holds  gener- 
ally in  Cornwall,  and  the  more  obtuse  the  angle  of  incidence,  the  more  considerable  the 
out-throw. 

The  great  copper  vein  of  Carharack,  in  the  parish  of  Gwenap,  is  a  most  instractive 
example  of  intersection.  The  power  of  this  vein  is  8  feel ;  it  runs  nearly  from  east  to 
west,  and  dips  toward  the  north  at  an  inclination  of  2  feet  in  a  fathom.  Its  upper  part 
is  in  the  killas,  its  lower  part  in  the  granite.  The  vein  has  suffered  two  intersections ; 
the  first  results  from  encountering  the  vein  called  Steven's  fluckan,  which  mns  from  north- 
east to  south-west,  throwing  it  out  several  fathoms.  The  second  has  been  caused  by 
another  vein,  almost  at  right  angles  to  the  first,  and  which  has  driven  it  20  fathoms  out 
to  the  right  side.  The  fall  of  the  vein  occurs,  therefore,  in  one  case  to  the  right,  and  in 
the  other  to  the  left ;  but  in  both  instances,  it  is  to  the  side  of  the  obtuse  angle.  This 
disposition  is  very  singular ;  for  one  portion  of  the  vein  appears  to  have  ascended,  while 
another  has  sunk. 

The  mining  works  in  the  copper  veins  are  carried  on  by  reverse  steps ;  see  Mines 
The  grand  shafts  for  drainage  and  extraction  are  vertical,  and  open  upon  the  roof  side 
of  the  vein,  traversing  it  to  a  certain  depth.    These  pits  are  sunk  to  the  lowest  point  of 
the  exploration ;  and,  in  proportion  as  the  workings  descend,  by  means  of  excavations 
m  the  vein,  the  pits  are  deepened  and  put  into  communication  toward  their  bottom  with 


COPPER.  460 

each  new  gallery  of  elongation,  by  means  of  transverse  galleries.  At  present,  the  mail 
shafts  are  fully  160  fathoms  deep.  Their  horizontal  section  is  oblong,  and  is  divided  into 
two  4iompartments ;  the  one  destined  for  extraction,  the  other  for  the  pumps.  Their  tim- 
bering has  nothing  remarkable,  but  is  executed  with  every  attention  to  economy,  the 
whole  wood  employed  in  these  mines  being  brought  from  Norway. 

The  descent  of  the  workmen  is  effected  by  inclined  shafts  scooped  out  of  the  vein ;  the 
ladders  are  slightly  inclined;  they  are  intermpted  every  10  fathoms  by  floors;  the  steps 
are  made  of  iron,  and,  to  prevent  them  from  turning  under  the  foot,  the  form  of  a  miner's 
punch  or  jumper  has  been  given  them,  the  one  end  being  round,  and  the  other  being 
wedge-shaped. 

The  ore  is  raised  either  by  means  of  horse-gins,  or  by  steam-engine  power,  most  fire- 
quently  of  high  pressure.     I  shall  take  the  Consolidated  Mines  as  an  example. 

The  draining,  which  is  one  of  the  most  considerable  sources  of  expense,  both  from  the 
quantity  of  water,  and  from  the  depth  of  the  mine,  is  executed  by  means  of  sucking  and 
forcing  pumps,  the  whole  piston-rods  of  which,  120  feet  long,  are  attached  to  a  main-rod 
suspended  at  the  extremity  of  the  working  beam  of  a  steam-engine. 

On  this  mine  three  steam-engines  are  erected  of  very  great  power,  for  the  purpose  of 
drainage  ;  the  one  called  the  Maria  engine  is  of  the  first-rate  force,  and  most  improved 
construction.  The  cylinder  is  90  inches  in  internal  diameter,  and  the  length  of  the 
stroke  is  9  feet  1 1  inches.  It  works  single  stroke,  and  is  incased  in  a  coating  of  bricks 
to  prevent  dissipation  of  the  heat.  The  vapor  is  admitted  at  the  upper  end  of  the 
cylinder  during  the  commencement  of  the  fall  of  the  piston,  at  a  pressure  capable  of 
forming  an  equilibrium  with  a  column  of  60  inches  of  mercury.  The  introduction  of 
the  steam  ceases  whenever  the  piston  has  descended  through  a  certain  space,  which  may 
be  increased  or  diminished  at  pleasure.  During  the  remainder  of  the  descent  the  piston 
is  pressed  merely  by  this  vapor  in  its  progressive  expansion,  while  the  under  side  of 
the  piston  communicates  with  the  condenser.  It  ascends  by  the  counterweight  at  the 
pump  end  of  the  working  beam.  Hence,  it  is  only  during  the  descent  of  the  piston  that 
the  effective  stroke  is  exerted.  Frequently  the  stefiun  is  admitted  only  during  the  sixth 
part  of  the  course  of  the  piston,  or  18  inches.  In  this  way  the  power  of  the  engine  is 
proportioned  to  the  work  to  be  done ;  that  is,  to  the  body  of  water  to  be  raised.  The 
maximum  force  of  the  above  engine  is  about  310  horses ;  though  it  is  often  made  to  act 
with  only  one  third  of  this  power. 

The  copper  mines  of  the  Isle  of  Anglesey,  those  of  North  Wales,  of  Westmoreland, 
the  adjacent  parts  of  Lancashire  and  Cumberland,  of  the  south  west  of  Scotland,  of  the 
Isle  of  Man,  and  of  the  south  east  of  Ireland,  occur  also  in  primitive  or  transition  rocks. 
The  ores  lie  sometimes  in  masses,  but  more  frequently  in  veins.  The  mine  of  Ecton  in 
Staffordshire,  and  that  of  Cross-gill  burn,  near  Alston-moor  in  Cumberland,  occur  in 
transition  or  metalliferous  limestone. 

Th6  copper  ores  extracted  both  from  the  granitic  and  schistose  localities,  as  well  as 
from  the  calcareous,  are  uniformly  copper  pyrites  more  or  less  mixed  with  iron  pyrites ; 
the  red  oxyde,  carbonate,  arseniate,  phosphate,  and  muriate  of  copper,  are  very  rare  in 
these  districts. 

The  working  of  copper  in  the  Isle  of  Anglesey  may  be  traced  to  a  very  remote  era.  It 
appears  that  the  Romans  were  acquainted  with  the  Hamlet  mine  near  Holyhead ;  but  it 
was  worked  with  little  activity  till  about  70  years  ago.  This  metalliferous  deposite  lies 
in  a  greenish  clay  slate,  passing  into  talc  slate ;  a  rock  associated  with  serpentine  and 
euphotide  (gahbro  of  Von  Buch).  The  veins  of  copper  are  from  one  to  two  yards  thick, 
and  they  converge  towards  a  point  where  their  union  forms  a  consideraWe  mass  of 
ore.  On  this  mass  the  mine  was  first  pierced  by  an  open  excavation,  which  is  now 
upwards  of  300  feet  deep,  and  appears  from  above  like  a  vast  funnel.  Galleries  arc 
formed  at  different  levels  upon  the  flank  of  the  excavation  to  follow  the  several  small 
veins,  which  run  in  all  directions,  and  diverge  from  a  common  centre  like  so  many  radiu 
The  ore  receives  in  these  galleries  a  kind  of  sorting,  and  is  raised  by  means  of  hand 
windlasses  to  the  summit  of  a  hill,  where  it  is  cleaned  by  breaking  and  riddling. 

The  water  is  so  scanty  in  this  mine  that  it  is  pumped  up  by  a  six-horse  steam-engine. 
A  great  proportion  of  it  is  charged  with  sulphate  of  copper.  It  is  conveyed  into  reser- 
voirs containing  pieces  of  old  iron ;  the  sulphate  is  thus  decomposed  into  copper  of  c©» 
mentation.  The  Anglesea  ore  is  poor,  yielding  only  from  2  to  3  per  cent,  of  copper :  a 
portion  of  its  sulphur  is  collected  in  roasting  the  ore. 

Mechanical  preparation  of  the  copper  ores  in  Cornwall. — The  ore  receives  a  first  sort- 
ing, either  within  the  mine  itself,  or  at  its  mouth,  the  object  of  which  is  to  separate  all 
the  pieces  larger  than  a  walnut.  These  are  then  reduced  by  the  hammer  to  a  smaller 
size ;  after  which  the  whole  are  sorted  into  four  lots,  according  to  their  relative  richness. 
The  fragment?  of  poor  ore  are  pounded  in  the  stamps  so  that  the  metallic  portion  may  be 
separated  by  washing. 

The  rich  ore  is  broken  into  small  bits,  of  the  size  of  a  nut,  with  a  flat  beater,  formal 


Ill 

.  I 

I 

i 


470 


COPPER. 


of  a  piece  of  iton  6  inches  square  and  1  inch  thick,  adapted  to  a  wooden  handle.  The 
ore  to  be  bioken  is  placed  upon  plates  of  cast-iron ;  each  about  16  inches  square  and  1| 
inch  thick.  These  iron  plates  are  set  towards  the  edge  of  a  small  mound  about  a  yard 
high,  constructed  with  dry  stones  rammed  with  earth.  The  upper  surface  of  this 
mound  is  a  little  inclined  from  behind  forwards.  The  work  is  performed  by  women, 
each  furnished  with  a  beater ;  the  ore  is  placed  in  front  of  them  beyond  the  plates ;  they 
break  it,  and  strew  it  at  their  feet,  whence  it  is  lifted  and  disposed  of  to  the  smeltmg- 
houses. 

Inferior  ores,  containing  a  notable  proportion  of  stony  matters,  are  also  broken  with 
the  beater,  and  the  rich  parts  are  separated  by  riddling  and  washing  from  the  useless 
matters. 

The  smaller  ore  is  washed  on  a  sieve  by  shaking  it  in  a  stream  of  water,  which  carries 
away  the  lighter  stony  pieces,  and  leaves  the  denser  metalliferous.  They  are  then 
sorted  by  hand.  Thus  by  beating,  stamping,  and  riddling  in  water,  the  stony  substances 
are  in  a  great  measure  separated.  The  finer  ground  matter  is  washed  on  a  plane  table, 
over  which  a  current  of  water  is  made  to  flow.  Finally,  the  ore  nearly  fine  is  put  into 
a  large  tub  with  water,  and  briskly  stirred  about  with  a  shovel,  after  which  it  settles  in 
the  order  of  richness,  the  pure  metallic  ore  being  nearest  the  bottom.  The  stamps  used 
for  copper  ore  in  Cornwall  are  the  same  as  those  used  for  tin  ores,  of  which  we  shall 
speak  in  treating  of  the  latter  metal,  as  well  as  of  the  boxes  for  washing  the  fine  powder 
or  slime.  These,  in  fact,  do  not  differ  essentially  from  the  stamping  mills  and  washing 
apparatus  described  in  the  article  Metallurgy.  Crushing  rolls  are  of  late  years  much 
employed.    See  Lead  and  Tin. 

Cornwall  being  destitute  of  coal,  the  whole  copper  ore  which  this  county  produces 
is  sent  for  smelting  to  South  Wales.  Here  are  15  copper  works  upon  the  Swansea  and 
Neath,  which  pursue  a  nearly  uniform  and  much  improved  process,  consisting  in  a  series 
of  calcinations,  fusions,  and  roaslings,  executed  upon  the  ores  and  the  matters  resulting 
from  them. 

The  furnaces  are  of  the  reverberatory  construction ;  they  vary  in  their  dimensions  and 
in  the  number  of  their  openings,  according  to  the  operations  for  which  they  were  in- 
tended. There  are  5  of  them  :— 1.  The  calcining  furnace  cr  calciner;  2.  The  melting 
furnace ;  3.  The  roasting  furnace  or  roaster ;  4.  The  refining  furnace ;  5.  The  heating 
or  igniting  furnace. 

1.  The  calcining  furnace  rests  upon  a  vault,  c,dnto  which  the  ore  is  raked  down  after 
being  calcined;  it  is  built  of  bricks, and  bound  with  iron  bars,  as  shown  in  the  elevation, 
fig.  368.  The  hearth,  b  B,figs.  368  and  370,  is  placed  \i\wn  a  level  with  the  lower  horizon- 
tal binding  bar,  and  has  nearly  the  form  of  an  ellipse,  truncated  at  the  two  extremities  of 
its  great  axis.  It  is  horizontal,  bedded  with  fire-bricks  set  on  edge,  so  that  it  may  be  re- 
moved and  repaired  without  disturbing  the  arch  upon  which  it  reposes.    Holes,  not  visible 


m  the  figure,  are  left  in  the  shelves  before  each  door,  c  c,  through  which  the  roasted  ore 
is  let  fall  into  the  subjacent  vault.  The  dimensions  of  the  hearth  b  b  are  immense,  beinj 
from  17  to  19  feet  in  length,  and  from  14  to  16  in  breadth.  The  fire-place,  a.  Jig.  370,  is 
from  4i  to  5  feet  long,  and  3  feet  wide.  The  bridge  or  low  wall,  bjfig.  374,  which  sepa- 
rates the  fire-place  from  the  hearth,  is  2  feet  thick ;  and  in  Mr.  Vivian's  smelting-worki 
is  hollow,  as  shown  in  the  figure,  and  communicates  at  its  two  ends  with  the  atniosphere, 
in  order  to  conduct  a  supply  of  fresh  air  to  the  hearth  of  the  furnace.  This  judicious 
contrivance  will  be  described  in  explaining  the  roasting  operation.  The  arched  roof  of 
the  furnace  slopes  down  from  the  bridge  to  the  beginning  of  the  chimney,  f,figs.  369, 
870,  its  height  above  the  hearth  being  at  the  first  point  about  26  inches,  and  from  8  to  12 
at  the  second. 

Such  great  calcining  furnaces  have  4  or  5  doors,  ccc  c,fig.  370,  one  for  the  fire-place, 
ts  shown  at  the  right  hand  in  fig.  369,  and  3  or  4  others  for  working  the  ore  np^n  the 


COPPER. 


471 


' 


leverberatory  hearth.  If  there  be  3,  2  of  them  are  placed  between  the  vertical  bmding 
bars  upon  one  side,  and  a  third  upon  the  opposite  side  of  the  furnace ;  if  there  be  4,  2 
are  placed  upon  each  side,  facing  one  another.  These  openings  are  12  inches  square, 
and  are  bound  with  iron  frames.  The  chimney  is  about  22  feet  high,  and  is  placed  at 
one  angle  of  the  hearth,  as  at/,^g.  870,  being  joined  by  an  inclined  flue  to  the  furnace. 
For  charging  it  with  ore  there  are  usually  placed  above  the  upper  part  ol  the  vault ^ 
hoppers,  E  E,  in  a  line  with  the  doors ;  they  are  formed  of  4  plates  of  iron,  supported  m 
an  iron  frame.    Beneath  each  of  them  there  is  an  orifice  for  letting  the  ore  down  mto  the 

These  furnaces  serve  for  calcining  the  ore,  and  the  matts  or  crude  coppers :  for  the  latter 
purpose,  indeed,  furnaces  of  two  stories  are  sometimes  employed,  as  represented  myig.  878. 
The  dimensions  of  each  floor  in  this  case  are  a  little  less  than  the  preceding.  Two  doors, 
c  c,  correspond  to  each  hearth,  and  the  workmen,  while  employed  «t  the  upper  story,  stand 
upon  a  raised  moveable  platform.  .^     t.         r  *i. 

2.  Melting  furnace,  figs.  Zll  and  372.  The  form  of  the 
hearth  is  also  elliptical,  but  the  dimensions  are  smaller  than 
871,872  in  the  calcining  furnace.  The  length  does  not  exceed  11  or  11  f 
feet,  and  the  breadth  varies  from  7  to  8.  The  fire-place  is 
however  larger  in  proportion,  its  length  being  from  3J  feet 
to  4,  and  its  breadth  from  3  to  3| ;  this  size  being  requisite 
to  produce  the  higher  temperature  of  this  furnace.  It  has 
fewer  openings,  there  being  commonly  three;  one  to  the 
fire-place  at  i),  a  second  one,  o,  in  the  side,  kept  generaUy 
shut,  and  used  only  when  incrustations  need  to  be  scraped 
off  the  hearth,  or  when  the  furnace  is  to  be  entered  for 
repairs;  and  the  third  or  working-door,  g,  placed  on  the 
front  of  the  furnace  beneath  the  chimney.  Through  it  the 
scoriae  are  raked  out,  and  the  melted  matters  are  stirred  and 

puddled,  &c. 

The  hearth  is  bedded   with  infusible  sand,   and   slopes 
slightly  towards  the  side  door,  to  facilitate  the  discharge  of 

. .  the  metal.    Above  this  door  there  is  a  hole  in  the  wall  of  the 

chimney  (fig-  872)  for  letting  the  metal  escape.  An  iron  gutter,  o,  leads  it  into  a  pit,  k, 
bottomed  with  an  iron  receiving-pot,  which  may  be  lifted  out  by  a  crane.  The  pit  m  is 
fiUed  with  water,  and  the  metal  becomes  granulated  as  it  falls  into  the  receiver.  me 
melting  furnaces  are  surmounted  by  a  hopper,  L,  as  shown  in  ^g.  371.  ,  .    ♦• 

Melting  furnaces  are  sometimes  used  also  for  calcination. 
There  are  some  such  near  Swansea,  which  serve  this  double 
purpose ;  they  are  composed  of  3  floors  (fig.  373.)  The  floor 
A  is  destined  for  melting  the  calcined  ore ;  the  other  two, 
B  c,  serve  for  calcination.  The  heat  being  less  powerful, 
upon  the  upper  sole  c,  the  ore  gets  dried  upon  it,  and  begms 
to  be  calcined  —  a  process  completed  on  the  next  floor. 
Square  holes,  rf,  left  in  the  hearths  B  and  c,  put  them  in 
communication  with  each  other,  and  with  the  lower  one  A  ; 
these  perforations  are  shut  during  the  operation  by  a  sheet 

of  iron,  removeable  at  pleasure.  ,    . 

The  hearths  6  and  c  are  made  of  bricks;  they  are  honzonal  at  top  and  slightly  vaulted 
beneath  :  they  are  2  bricks  thick,  and  their  dimensions  are  larger  than  those  of  the  infe- 
rior hearths,  as  they  extend  above  the  fire-place.  On  the  floors  destined  for  calcination 
the  furnace  has  two  doors  on  one  of  its  sides  :  on  the  lower  story  there  are  also  two ;  but 
they  are  differently  collocated.  The  first,  being  in  the  front  of  the  furnace,  serves  for 
drawin-  off  the  scoria,  for  working  the  metal,  &c. ;  and  the  second,  upon  the  side,  admits 
workmen  to  make  necessary  repairs.  Below  this  door  the  discharge  or  lap-hole  a  is 
placed,  which  communicates  by  a  cast-iron  gutter  with  a  pit  filled  with  water,  ine 
dimensions  of  this  furnace  in  length  and  breadth  are  nearly  the  same  as  those  of  ^he 
melting  furnace  above  described;  the  total  height  is  nearly  12  feet.      It  is  charged  oy 

means  of  one  or  two  hoppers.  ,       ,  ^      ,..  •„  „„„«r«l  iinitlo. 

3.  Roasting  furnace.  —  The  furnaces  employed  for  this  purpose  are  m  ?;n^J«' ■J***^ 
gous  to  the  calling  ones;  but  in  the  smelting  works  of  Hafod,  the  property  of  M^. 
Vivian,  these  furnaces,  alluded  to  above,  present  a  peculiar  ?o"Stniction,  for  the  purpose 
of  introducing  a  continuous  current  of  air  upon  the  metaU  in  order  to  'a^.'"^^^  I^  °*^, 
dizemeT  This  process  was  originally  invented  by  Mr.  Sheffield,  who  disposed  of  his 
tMitent  right  to  Messrs.  Vivian.  ^  ,     /.     v  •-».,«  <«.  qta  aimI 

The  aii  is  admitted  by  a  channel,  c  c,  through  the  middle  of  the  fi^^;^"^^^' ■^^- ^I^'.^J^ 
extending  all  its  length;  it  communicates  with  the  atmosphere  f-V^M ^^LJ^^f^  ^^^ 
•quare  holes,  6  6,  left  at  right  angles  to  this  channel,  conduct  the  air  into  the  m- 


472 


COPPER. 


f-, 


IK: 


n.^i 


■Tiri 


'I 

f  : 
V  ■ 


If  -  I  I 


i    ', 


r  ' ' 


nacb.  This  very  simple  construction  produces  a  powerful  effect  in  the  roasting  opem- 
lion.  It  not  only  promotes  the  oxydizement  of  the  metals,  but  burns  the  smoke,  and  as- 
sists  in  the  vaporjzation  of  the  sulphur  ;  while  by  keeping  the  bridge  cool  it  preserves  it 
from  wasting,  and  secures  uniformity  of  temperature  to  the  hearth, 

4.  Refinittg  furnace.  —  In  this,  as  in  the  melting  furnace,  the  sole  slopes  towardft 
the  door  in  front,  instead  of  towards  the  side  doors,  because  in  the  refining  furnace  the 
copper  collects  into  a  cavity  formed  in  the  hearth  towards  the  front  door,  from  which  it 
is  lifted  out  by  ladles ;  whereas,  in  the  melting  furnaces,  the  metal  is  run  out  by  a  tap- 
hole  in  the  side.  The  hearth  sole  is  laid  with  sand  ;  but  the  roof  is  higher  than  in  the 
melting  furnace,  being  from  32  to  36  inches.  If  the  top  arch  were  too  much  depressed, 
there  might  be  produced  upon  the  surface  of  the  metal  a  layer  of  oxyde  very  prejudicial 
to  the  quality  of  the  copper.  When  the  metal  in  that  case  is  run  out,  its  surface  so- 
lidifies and  cracks,  while  the  melted  copper  beneath  breaks  through  and  spreads  irregu- 
lafly  over  the  cake.  This  accident,  called  the  rising  of  the  coppery  hinders  it  from  being 
laminated,  and  requires  it  to  be  exposed  to  a  fresh  refining  process,  when  lead  must  be 
added  to  dissolve  the  oxyde  of  copper.  This  •'«  the  only  occasion  upon  which  the  addi- 
tion of  lead  is  proper  in  refining  copper.  When  the  metal  to  be  refined  is  mixed  with 
Others,  particularly  with  tin,  as  in  extracting  copper  from  old  bells,  then  very  wide  fur- 
naces must  be  employed,  to  expose  the  metallic  bath  upon  a  great  surface,  and  in  a  thin 
stratum,  to  the  oxydizing  action  of  the  air. 

The  door  g,  fg.  372,  upon  the  side  of  the  refining  furnace,  is  very  large,  and  is  shut 
with  a  framed  brick  door,  balanced  by  a  counter-weight.  This  door  being  open  during 
the  refining  process,  the  heat  is  stronger  at  b  than  at  K,{figs.  371,312.) 

5.  Heating  furnaces^  being  destined  to  heat  the  pigs  or  bars  of  copper  to  be  laminated, 
as  well  as  the  copper  sheets  themselves,  are  made  much  longer  in  proportion  to  their 
breadth.  Their  hearth  is  horizontal,  the  vault  not  much  depressed  ;  they  have  only  one 
door,  placed  upon  the  side,  but  which  extends  nearly  the  whole  length  of  the  furnace ; 
this  door  may  be  raised  by  means  of  a  counter- weight,  in  the  same  way  as  in  the  furnaces 
for  the  fabrication  of  sheet-iron  and  brass. 

Series  of  operations  to  which  the  are  is  svbjecttd.  —  The  ores  which  are  smelted  in  the 
Swansea  works  are  cupreous  pyrites,  more  or  less  mingled  with  gangue  (vein-stone).  The 
pyrites  is  composed  of  nearly  equal  proportions  of  sulphuret  of  copper  and  sulphuret  of 
iron. 

The  earthy  matters  which  accompany  the  pyrites  are  usually  silicious,  though  in  some 
mines  the  metalliferous  deposite  is  mixed  with  clay  or  fluate  of  lime.  Along  with  these 
substances,  pretty  uniformly  distributed,  tin  and  arsenical  pyrites  occur  occasionally 
with  the  copper ;  and  though  these  two  metals  are  not  chemically  combined,  yet  they 
cannot  be  separated  entirely  in  the  mechanical  preparations.  The  constituent  parts  of 
the  ore  prepared  for  smelting  are,  therefore,  copper,  iron,  sulphur,  with  tin,  arsenic, 
and  earthy  matters  in  some  cases.  The  different  ores  are  mixed  in  such  proportions 
that  the  average  metallic  contents  may  amount  to  8^  per  cent.  The  smelting  process 
consists  in  alternate  roastings  and  fusions.  The  following  description  of  it  is  chiefly 
taken  from  an  excellent  paper,  published  by  John  Vivian,  Esq.,  in  the  Annals  of  Philo- 
sophy for  1823. 

In  the  roasting  operation  the  volatile  substances  are  disengaged  mostly  in  the  gaseons 
state,  while  the  metals  that  possess  a  strong  affinity  for  oxygen  become  oxydized.  In 
the  fusion  the  earthy  substances  combine  with  these  oxydes,  and  form  glassy  scoriae  or 
slags  which  float  upon  the  surface  of  the  melted  metal. 

These  calcinations  and  fusions  take  place  in  the  following  order :  — 

1.  Calcination  of  the  ore.  2.  Melting  of  the  calcined  ore.  3.  Calcination  of  the 
coarse  metal.  4.  Melting  of  the  calcined  coarse  metal.  5.  Calcination  of  the  fine 
metal  (second  matt).  6.  Melting  of  the  calcined  fine  metal.  7.  Roasting  of  the 
coarse  copper.  In  some  smelting  works,  this  roasting  is  repeated  four  times;  in 
which  case  a  calcination  and  a  melting  are  omitted.  In  the  Havod  works,  however, 
the  same  saving  is  made  without  increasing  the  number  of  roastings.  8.  Refining  or 
toughening  the  copper. 

Besides  these  operations,  which  constitute  the  treatment  of  copper  properly  speaking, 
two  others  are  sometimes  performed,  in  which  only  the  scoriae  are  melted.  These  may 
be  designated  by  the  letters  a  and  6.  a  is  the  re-melting  of  the  portion  of  the  scoriae 
of  the  second  process,  which  contain  some  metallic  granulations.  6  is  a  particular  melt- 
ing of  the  scoriaB  of  the  fourth  operation.  This  fusion  is  intended  to  concentrate  the 
X>articles  of  copper  in  the  scoriae,  and  is  not  practised  in  all  smelting  works. 

First  operation.     Calcination  of  the  ore. —  The  different  c/es,  on  arriving  from  Corn- 
wall and  other  distiicts  where  they  are  mined,  are  discharged  in  continuous  cargoes  at 
the  smelting  works,  in  such  a  way,  that  by  taking  out  a  portion  from  several  heaps  at. 
n  time,  a  tolerably  uniform  mixture  of  ores  is  obtained ;  which  is  very  essential  in 
•  foundry,  because,  the  ores  being  different  in  qualities  and  contents,  they  act  m 


COPPER. 


473 


fluxes  upon  each  other.  The  ore  thus  mixed  is  transported  to  the  works  in  wooden 
measures  that  hold  a  hundred-weight.  The  workmen  intrusted  with  the  calcination 
convey  the  ore  into  the  hoppers  of  the  calcining  furnace,  whence  it  falls  into  the  hearth; 
other  workmen  spread  it  uniformly  on  the  surface  by  iron  rakes.  The  charge  o!  a  fur- 
nace is  from  three  tons  to  three  tons  and  a  half.  Fire  is  applied  and  gradually  increased, 
till,  towards  the  end  of  the  operation,  the  temperature  be  as  high  as  the  ore  can  support 
without  melting  or  agglutinating.  To  prevent  this  running  together,  and  to  aid  the  ex- 
trication of  the  sulphur,  the  surfaces  are  renewed,  by  stirring  up  the  ore  at  the  ena  oi 
every  hour.  The  calcination  is  usually  completed  at  the  end  of  12  hours,  when  the  ore 
is  tumbled  into  the  arch  under  the  sole  of  the  furnace.  Whenever  the  ore  is  cold  enougH 
to  be  moved,  it  is  taken  out  of  the  arch,  and  conveyed  to  the  calcined  heap. 

The  ore  in  this  process  hardly  changes  weight,  having  gained  in  oxydizctnent  nearly 
as  much  as  it  has  lost  in  sulphur  and  arsenic;  and  if  the  roasting  has  been  righUy  man- 
aged, the  ore  is  in  a  black  powder,  owing  to  the  oxyde  of  iron  present. 

Second  operation.  Fusion  of  the  calcined  ore.— The  calcined  ore  is  likewise  given  to 
the  melters  in  measures  containing  a  hundred  weight.  They  toss  it  into  hoppers,  and 
after  it  has  fallen  on  the  hearth,  they  spread  it  uniformly.  They  then  let  down  the 
door,  and  lute  it  tightly.  In  this  fusion  there  are  added  about  2  cwt.  of  scoriee  pro- 
ceeding from  the  melting  of  the  calcined  matt,  to  be  afterwards  described.  The  object 
of  this  addition  is  not  only  to  extract  the  copper  that  these  scoriae  may  contain,  but 
especially  to  increase  the  fusibility  of  the  mixture.  Sometimes  also,  when  the  composi- 
tion of  the  ore  requires  it,  lime,  sand,  or  fluor  spar  is  added;  and  particularly  the  last 

fluxmg  article.  ,  ^  ,     /.      j     •    .    i 

The  furnace  being  charged,  fire  is  applied,  and  the  sole  care  of  the  founder  is  to  keep 
up  the  heat  so  as  to  have  a  perfect  fusion;  the  workman  then  opens  the  door,  and 
Stirs  about  the  liquid  mass  to  complete  the  separation  of  the  metal  (or  rather  of  the 
matt)  from  the  scoriae,  as  well  as  to  hinder  the  melted  matter  from  sticking  to  the  sole. 
The  furnace  being  ready,  that  is,  the  fusion  being  perfect,  the  founder  takes  out  the 
scoriae  by  the  front  door,  by  means  of  a  rake.  When  the  matt  is  thus  freed  from  the 
scoriae,  a  second  charge  of  calcined  ore  is  then  introduced  to  increase  the  metallic  bath ; 
which  second  fusion  is  executed  like  the  first.  In  this  way,  new  charges  of  roasted  ore 
are  put  in  till  the  matt  collected  on  the  hearth  rises  to  a  level  with  the  door-way,  which 
happens  commonly  after  the  third  charge.  The  tap  hole  is  now  opened;  the  matt 
flows  out  into  the  pit  filled  with  water,  where  it  is  granulated  durmg  its  immersion; 
and  it  collects  in  the  pan  placed  at  the  bottom.  The  granulated  matt  is  next  con- 
veyed into  the  matt  warehouse.  The  oxydation  with  which  the  grains  get  covered  by 
the  action  of  the  water  does  not  allow  the  proper  color  of  the  matt  or  coarse  metal  to 
be  distinguished ;  but  in  the  bits  which  stick  in  the  gutter,  it  is  seen  to  be  of  a  steel 
gray.  Us  fracture  is  compact,  and  its  lustre  metallic.  The  scoriae  often  contain 
metallic  grains;  they  are  broken  and  picked  with  care.  All  the  portions  which  include 
some  metallic  particles  are  re-melted  in  an  accessory  process.  The  rejected  scoria 
have  been  found  to  be  composed  of  silicious  matter  59,  oxyde  of  copper  1,  oxyde  of 

In  this  operation,  the  copper  is  concentrated  by  the  separation  of  a  great  part  of  the 
matters  with  which  it  was  mixed  or  combined.  The  granulated  matt  produced,  contains 
in  eeneral  33  per  cent,  of  copper;  it  is  therefore  four  times  richer  than  the  ore;  and  its 
mass  is  consequently  diminished  in  that  proportion.     The  constituent  parts  are  prmci- 

pally  copper,  iron,  and  sulphur.  .,..,.  ,        r    -vi       • 

The  most  important  point  to  hit  in  the  fusion  just  described,  is  to  make  a  fusible  mix- 
ture of  the  earths  and  the  oxydes,  so  that  the  matt  of  copper  may,  in  virtue  of  its  greater 
specific  gravity,  fall  to  the  under-part,  and  separate  exactly  from  the  slag.  This  point  is 
attainetlby  means  of  the  metallic  oxydes  contained  in  the  scoriae  of  the  fourth  operation, 
of  which  2  cwt.  were  added  to  the  charge.  These  consist  almost  entirely  of  black  oxyde 
of  iron.  When  the  ores  are  very  difiicult  to  melt,  a  measure  of  about  half  a  hundred- 
weight of  fluor  spar  is  added ;  but  this  must  be  done  with  precaution,  for  fear  of  m- 
creasing  the  scoriae  too  much.  .  v      i    • 

The  business  goes  on  day  and  night.  Five  charges  are  commonly  put  through  hands  in 
the  course  of  24  hours ;  but  when  all  circumstances  are  favorable— that  is  to  say,  when 
the  ore  is  fusible,  when  the  fuel  is  of  the  first  quality,  and  when  the  furnace  is  in  good 
condition,  even  six  charges  a  day  have  been  despatched. 

The  charge  is  a  ton  and  a  half  of  calcined  ore,  so  that  a  melting  furnace  corresponds 
nearly  to  a  calcining  furnace ;  the  latter  turning  out  nearly  7  tons  of  calcined  ore  m  Z4 
hours. 

The  workmen  are  paid  by  the  ton.  .     «,.       v-    ♦  ^e  ♦!.:. 

Third  operation.  Calcination  of  the  coarse  metal,  or  the  ma//.— The  object  ol  this 
operation  is  principally  to  oxydize  the  iron,  an  oxydation  easier  to  execute  than  m  the  first 


474 


COPPER. 


II 


ealcininsr,  because  the  metal  is  now  disengaged  from  the  earthy  sobstances  which 
screened  it  from  the  action  of  the  air. 

This  calcination  is  executed  in  the  furnace  already  represented,  _^g«.  296,  297  298, 
page  324,  exactly  in  the  same  way  as  the  ore  was  calcined.  The  metal  must  be  perpetn! 
illy  stirred  about,  to  expose  all  its  surfaces  to  the  action  of  the  hot  air,  and  to  hinder  the 
clotting  together.  The  operation  lasts  24  hours;  during  the  first  six,  the  fire  should  be 
Very  moderate,  and  thereafter  gradually  increased  to  the  end  of  the  calcination.  The 
chaise  is,  like  that  of  the  first,  3  tons  and  a  half. 

Fourth  operation.    Melting  of  the  calcined  coarse  metal,  or  calcined  matt. In  the 

fusion  of  this  first  calcined  matt,  some  scoriffi  of  the  latter  operations  must  be  added,  which 
are  very  rich  in  oxyde  of  copper,  and  some  crusts  from  the  hearth,  which  are  likewise 
impregnated  with  it.  The  proportion  of  these  substances  varies  according  to  the  qualitj 
of  the  calcined  malt. 

In  this  second  fusion,  the  oxyde  of  copper  contained  in  the  scoriae  is  reduced  by  the 
affinity  of  the  sulphur,  one  portion  of  which  passes  to  the  state  of  acid,  while  the  other 
forms  a  subsulphurel  with  the  copper  become  free.  The  matt  commonly  contains  a  suf- 
ficient quantity  of  sulphur  to  reduce  the  oxyde  of  copper  completely;  but  if  not,  which 
may  happen  if  the  calcination  of  the  matt  has  been  pushed  too  far,  a  small  quantity  of 
uncalcined  matt  must  be  introduced,  which,  by  furnishing  sulphur,  diminishes  the  ricli- 
ness  of  the  scoriae,  and  facilitates  the  fusion. 

The  scoriae  are  taken  out  by  the  front  door,  by  drawing  them  forward  with  a  rake. 
They  have  a  great  specific  gravity;  are  brilliant  with  metallic  lustre,  very  crystalline, 
and  present,  in  the  cavities,  crystals  like  those  of  pyroxene ;  they  break  easily  into  verr 
sharp-edged  fragments.    They  contain  no  granulated  metal  in  the  interior ;  but  it  some 
times  occurs,  on  account  of  the  small  thicknesses  of  the  stratum  of  scorise,  that  these  car 
ry  off  with  them,  when  they  are  withdrawn,  some  metallic  particles. 

These  scoriae,  as  we  have  already  stated,  under  the  fusion  of  the  roasted  ore,  are  ii 
general  melted  with  it.    In  some  cases,  however,  a  special  melting  is  assigned  to  them. 

The  matt  obtained  in  this  second  fusion  is  either  run  out  into  water  like  the  first,  or 
moulded  into  pigs  (ingots),  according  to  the  mode  of  treatment  which  it  is  to  undergo. 
This  matt,  called  by  the  smelters  yine  mefal  when  it  is  granulated,  and  bine  metal  when  it 
is  in  pigs,  is  of  a  light  gray  color,  compact,  and  bluish  at  the  surface.  It  is  collected 
in  the  first  form  when  it  is  to  be  calcined  anew ;  and  in  the  second,  when  it  must 
immediately  undergo  the  operation  of  roa«/t?jg.  Its  contents  in  copper  are  60  per  cent. 
This  operation,  which  is  sometimes  had  recourse  to,  lasts  5  or  6  hours.  The  charge  is  1 
Ion. 

(6)  Particular  fusion  of  the  scoria  of  the  fourth  operation. — In  re-melting  these  scoriae 
the  object  is  to  procure  the  copper  which  they  contain.  To  effect  this  fusion,  the  scorie 
are  mixed  with  pulverized  coal,  or  other  carbonaceous  matters.  The  copper  and  several 
other  metals  are  deoxydized,  and  furnish  a  white  and  brittle  alloy.  The  scoriee  resulting 
from  this  taelting  are  in  part  employed  in  the  first  melting,  and  in  part  thrown  away. 
They  are  crystalline,  and  present  crystals  oAen  in  the  cavities,  which  appear  to  belong 
to  ksilicale  of  iron  They  have  a  metallic  lustre,  and  break  into  very  sharp-edged 
fragments.  The  white  metal  is  melted  again,  and  then  united  to  the  product  of  the 
second  fusion. 

Fifth  operation.  Calcination  of  the  second  matt,  or  fine  metal  of  the  smelter. — This  is 
executed  in  precisely  the  same  way  as  that  of  the  first  matt.  It  lasts  24  hours;  and  the 
charge  is  usually  3  tons. 

Sixth  operation.  Melting  of  the  calcined  fine  metal. — ^This  fusion  is  conducted  like 
that  of  the  first  matt.  The  black  copper,  or  coarse  copper,  which  it  produces,  contains 
from  70  to  80  per  cent,  of  pure  metal ;  it  is  run  into  ingots,  in  order  to  undergo  the 
operation  of  roasting. 

The  scoriae  are  rich  in  copper;  they  are  added  to  the  fusion  of  the  calcined  coarse  metal 
of  the  fourth  operation. 

In  the  smelting  houses  of  Messrs.  Vivian,  at  Hafod,  near  Swansea,  the  fifth  and  sixth 
operations  have  been  omitted  of  late  years.  The  second  matt  is  run  into  pigs,  under  the 
name  of  blue  metal,  to  be  immediately  exposed  to  the  roasting. 

The  disposition  of  the  canal  a  a',  fig.  374,  which  introduces  a  continuous  current  of  air 
to  the  hearth  of  the  furnace,  accelerates  and  facilitates  the  calcination  of  the  matt;  an 
advantage  which  has  simplified  the  treatment,  by  diminishing  the  number  of  calculations. 

Seventh  operation.  Roasting  of  the  coarse  copper,  the  product  of  the  sixth  operation.^ 
The  chief  object  of  this  operation  is  oxydizement ;  it  is  performed  either  in  an  ordinary 
roasting  furnace,  or  in  the  one  belonging  to  fig.  302,  which  admits  a  constant  current  of 
air.  The  pigs  of  metal  derived  from  the  preceding  melting  are  exposed,  on  the  hearth 
of  the  furnace,  to  the  action  of  the  air,  which  oxydizes  the  iron  and  other  foreign  metals 
irith  which  the  copper  is  still  contaminated.     The  duration  of  the  roasting  varies  from 


COPPER. 


475 


4^ 


^ 


J2  to  24  hours,  according  to  the  degree  of  purity  of  the  crude  copper.  The  tempertturt 
should  le  graduated,  in  order  that  the  oxydizement  may  have  time  to  complete,  and  that 
the  volatile  substances  which  the  copper  still  retains  may  escape  in  the  gaseous  form. 
The  fusion  must  take  place  only  towards  the  end  of  the  operation. 

The  charge  varies  from  a  ton  and  a  quarter  to  a  ton  and  a  half.  The  metal  obtained 
i^  run  out  into  moulds  of  sand.  It  is  covered  with  black  blisters,  like  steel  of  cementation ; 
whence  it  has  got  the  name  of  blistered  copper.  In  the  interior  of  these  pigs,  the  copper 
presents  a  porous  texture,  occasioned  by  the  ebullition  produced  by  the  escape  of  the 
gases  during  the  moulding.  The  copper  being  now  aUnost  entirely  purged  from  the 
sulphur,  iron,  and  the  other  substances  with  which  it  was  combined,  is  in  a  fit  state  to  be 
refined.  This  operation  affords  some  scoriae ;  they  are  very  heavy,  and  contain  a  great 
deal  of  oxyde  of  copper,  sometimes  even  metallic  copper. 

These  scoriae,  as  well  as  those  of  the  third  melting  and  of  the  refining,  are  added  to  the 
second  fusion,  as  we  have  already  stated,  in  describing  the  fourth  operation. 

In  some  works,  the  roasting  is  repeated  several  times  upon  the  blue  metal,  in  order  to 
bring  it  to  a  state  fit  for  refining.  We  shall  afterwards  notice  this  modification  of  the 
treatment. 

Eighth  operation.  Refining  or  toughening.  — The  pigs  of  copper  intended  for  refining 
are  put  upon  the  sole  of  the  refining  furnace  through  the  door  in  the  side.  A  slight  heat 
is  first  given,  to  finish  the  roasting  or  oxydation,  in  case  this  operation  has  not  already 
been  pushed  far  enough.  The  fire  is  to  be  increased  by  slow  degrees,  so  that,  by  the  end 
of  6  hours,  the  copper  may  begin  to  flow.  When  all  the  metal  is  melted,  and  when  the 
heat  is  considerable,  the  workman  lifts  up  the  door  in  the  front,  and  withdraws  with  a 
rake  the  few  scoriae  which  may  cover  the  copper  bath.  They  are  red,  lamellated,  very 
heavy,  and  closely  resemble  protoxyde  of  copper. 

The  refiner  takes  then  an  assay  with  a  small  ladle,  and  when  it  cools,  breaks  it  in  a 
vice,  to  see  the  state  of  the  copper.  From  the  appearance  of  the  assay,  the  aspect  of  the 
bath,  the  state  of  the  fire,  &c.,  he  judges  if  he  may  proceed  to  the  toughening,  and  what 
quantity  of  wooden  spars  and  wood  charcoal  he  must  add  to  render  the  metal  malleable, 
or,  in  the  language  of  the  smelters,  bring  it  to  the  proper  pitch.  When  the  operation  of 
refining  begins,  the  copper  is  brittle  or  dry,  and  of  a  deep  red  color  approaching  to  purple. 
Its  grain  is  coarse,  open,  and  somewhat  crystalline. 

To  execute  the  refining,  the  surface  of  the  metal  is  covered  over  with  wood  charcoal, 
and  stirred  about  with  a  spar  or  rod  of  birch  wood.  The  gases  which  escape  from  the 
wood  occasion  a  brisk  effervescence.  More  wood  charcoal  is  added  from  time  to  time, 
so  that  the  surface  of  the  metal  may  be  always  covered  with  it,  and  the  stirring  is  con- 
tinued with  the  rods,  till  the  operation  of  refining  be  finished,  a  circumstance  indicated 
by  the  assays  taken  in  succession.  The  grain  of  the  copper  becomes  finer  and  finer, 
and  its  color  gradually  brightens.  When  the  grain  is  extremely  fine,  or  closed,  when 
the  trial  pieces,  half  cut  through  and  then  broken,  present  a  silky  fracture,  and  when  the 
copper  is  of  a  fine  light  red,  the  refiner  considers  the  operation  to  be  completed  ;  but  he 
verifies  still  further  the  purity  of  the  copper,  by  trying  its  malleability.  For  this  pur- 
pose, he  takes  out  a  sample  in  his  small  ladle,  and  pours  it  into  a  mould.  When  the 
copper  is  solidified,  but  still  red-hot,  he  forges  it.  If  it  is  soft  under  the  hammer,  if  it 
does  not  crack  on  the  edges,  the  refiner  is  satisfied  with  its  ductility,  and  he  pronounces 
it  to  be  in  its  proper  state.  He  orders  the  workmen  to  mould  it ;  who  then  lift  the 
copper  out  of  the  furnace  in  large  iron  ladles  lined  with  clay,  and  pour  it  into  moulds 
of  the  size  suitable  to  the  demands  of  commerce.  The  ordinary  dimensions  of  the  ingots 
or  pigs  are  12  inches  broad,  18  long,  and  from  2  to  2|  thick. 

The  period  of  the  refining  process  is  20  hours.  In  the  first  six,  the  metal  heats,  and 
suffers  a  kind*.of  roasting ;  at  the  end  of  this  time  it  melts.  It  takes  four  hours  to  reach 
the  point  at  which  the  refining,  properly  speaking,  begins ;  and  this  last  part  of  the 
process  lasts  about  4  hours.  Finally,  6  hours  are  required  to  arrange  the  moulds,  cast 
the  ingots,  and  let  the  furnace  cool. 

The  charge  of  copper  in  the  refining  process  depends  upon  the  dimensions  of  the  fur- 
nace. In  the  Hafod  works,  one  of  the  most  important  in  England,  the  charge  varies  from 
3  to  5  tons ;  and  the  quantity  of  pure  copper  manufactured  in  a  week  is  from  40  to  50  tons. 

The  consumption  of  fuel  is  from  15  to  18  parts  of  coal,  for  one  part  of  refined  copper 
in  pigs. 

When  the  copper  offers  difiiculties  in  the  refining,  a  few  pounds  of  lead  are  added  to 
it.  This  metal,  by  the  facility  with  which  it  scorifies,  acts  as  a  purifier,  aiding  the 
oxydation  of  the  iron  and  other  metals  that  may  be  present  in  the  copper.  The  lead 
ought  to  be  added  immediately  after  removing  the  door  to  skim  the  surface.  The  copper 
should  be  constantly  stirred  up,  to  expose  the  greatest  possible  surface  to  the  action  of  the 
air,  and  to  produce  the  complete  oxydation  of  the  lead ;  for  the  smallest  quantity  of  this 
metal  alloyed  in  copper,  is  diflicult  to  clear  up  in  the  lamination;  that  is  to  say,  the 
scale  of  oxyde  does  not  come  cleanly  from  the  surface  of  the  sheets. 


li 


If. 


II 


IK 


1  J  r  -     » 

4:  ? 


n 


• 


I   i 


■'  ^ 


476 


COPPER. 


The  operation  of  refining  copper  is  delicate,  and  requires,  npon  the  part  of  the  woiiC* 
men,  great  skill  and  attention  to  give  the  metal  its  due  ductility.  Its  surface  ought  to 
be  entirely  covered  with  wood  charcoal;  without  this  precaution,  the  refinii.g  of  the 
metal  would  go  backy  as  the  workmen  say,  during  the  long  interval  which  elapses  in  the 
moulding ;  whenever  this  accident  happens,  the  metal  must  be  stirred  up  anew  with  the 
wooden  pole. 

Too  long  employment  of  the  wooden  rod  gives  birth  to  another  remarkable  accident, 
for  the  copper  becomes  more  brittle  than  it  was  prior  to  the  commencement  of  the  re- 
fining; that  is,  when  it  was  dry.  Its  color  is  now  of  a  very  brilliant  yellowish  red, 
and  its  fracture  is  fibrous.  When  this  circumstance  occurs,  when  the  refining,  as  the 
workmen  say,  has  gone  ioofar,  the  refiner  removes  the  charcoal  from  the  top  of  the 
melted  metal ;  he  opens  the  side  door,  to  expose  the  copper  to  the  action  of  the  air,  and 
it  then  resumes  its  malleable  condition. 

Mr.  Vivian,  to  whom  we  owe  the  above  very  graphic  account  of  the  processes,  has 
explained,  in  a  very  happy  manner,  the  theory  of  refining.  He  conceives,  we  may  con- 
clude, that  the  copper  in  the  dry  state^  before  the  refining,  is  combined  with  a  sjmiII  por 
tion  of  oxygen,  or,  in  other  words,  that  a  small  portion  of  oxyde  of  copper  is  difi*used 
through  the  mass,  or  combined  with  it ;  and  that  this  proportion  of  oxygen  is  expelled 
by  the  deoxydizing  action  of  the  wood  and  charcoal,  whereby  the  metal  becomes  malle- 
able. 2.  That  when  the  refining  process  is  carried  too  far,  the  copper  gets  combined  with 
a  little  charcoal.  Thus  copper,  like  iron,  is  brittle  when  combined  with  oxygen  and 
charcoal ;  and  becomes  malleable  only  when  freed  entirely  from  these  two  substances. 

It  is  remarkable,  that  copper,  in  the  dry  state,  has  a  very  strong  action  upon  iron  ;  and 
that  the  tools  employed  in  stirring  the  liquid  metal  become  very  glistening,  like  those 
used  in  a  farrier's  forge.  The  iron  of  the  tools  consumes  more  rapidly  at  that  time,  than 
when  the  copper  has  acquired  its  malleable  state.  The  metal  requires,  also,  when  dry, 
more  time  to  become  solid,  or  to  cool,  than  when  it  is  refined ;  a  circumstance  depending, 
probably,  upon  the  difference  in  fusibility  of  the  copper  in  the  two  states,  and  which  seems 
to  indicate,  as  in  the  case  of  iron,  the  presence  of  oxygen. 

When  the  proper  refining  point  has  been  passed,  another  very  remarkable  circum- 
stance has  been  observed ;  namely,  that  the  surface  of  the  copper  oxydizes  more  difficultly, 
and  that  it  is  uncommonly  brilliant ;  reflecting  clearly  the  bricks  of  the  furnace  vault. 
This  fact  is  favorable  to  the  idea  suggested  above,  that  the  metal  is  in  that  case  combined 
with  a  small  quantity  of  carbon ;  which  absorbs  the  oxygen  of  the  air,  and  thus  protects 
the  metal  from  its  action. 

Copper  is  brought  into  the  market  in  difierent  forms,  according  to  the  purposes  which 
it  is  to  serve.  What  is  to  be  employed  in  the  manufacture  of  brass  is  granulated.  In 
this  condition  it  presents  more  surface  to  the  action  of  zinc  or  calamine,  and  combines 
with  it  more  readily.-  To  produce  this  granulation,  the  metal  is  poured  into  a  large 
ladle  pierced  with  holes,  and  placed  above  a  cistern  filled  with  water,  which  must  be 
hot  or  cold,  according  to  the  form  wished  in  the  grains.  When  it  is  hot,  round  grains 
are  obtained  analogous  to  lead  shot ;  and  the  copper  in  this  state  is  called  bean  shot. 
When  the  melted  copper  falls  into  cold  water  perpetually  renewed,  the  granulations  are 
irregular,  thin,  and  ramified ;  constituting /ea//ii?refll  shot.  The  bean  shot  is  the  form  em- 
ployed in  brass  making. 

Copper  is  also  made  into  small  ingots,  about  6  ounces  in  weight.  These  are  intended 
for  exportation  to  the  East  Indies,  and  are  known  in  commerce  by  the  name  of  Japan 
copper.  Whenever  these  little  pieces  are  solidified,  they  are  thrown,  while  hot,  into  cold 
water.  This  immersion  slightly  oxydizes  the  surface  of  the  copper,  and  gives  it  a  fine  red 
color. 

Lastly,  the  copper  is  often  reduced  into  sheets,  for  the  sheathing  of  ships,  and  many 
other  purposes.  The  Hafod  works  possess  a  powerful  rolling  mill,  composed  of  four 
pair?  of  cylinders.  It  is  moved  by  a  steam  engine,  whose  cylinder  has  40  inches 
diamete:.  See  the  representation  of  the  rolling  mill  of  the  Royal  Mint,  under 
Gold. 

The  cylinders  for  rolling  copper  into  sheets  are  usually  3  feet  long,  and  15  inches  in 
diameter.  They  are  uniform.  The  upper  roller  may  be  approached  to  the  under  one, 
by  a  screw,  so  that  the  cylinders  are  brought  closer,  as  the  sheet  is  to  be  made  thinner. 

The  ingots  of  copper  are  laid  upon  the  sole  of  a  reverberatory  furnace  to  be  heated ; 
they  are  placed  alongside  each  other,  and  they  are  formed  into  piles  in  a  cross-like  ar- 
rangement, so  that  the  hot  air  may  pass  freely  round  them  all.  The  door  of  the  furnace 
is  shut,  and  the  workman  looks  in  through  a  peep-hole  from  time  to  time,  to  see  if  they 
have  taken  the  requisite  temperature ;  namely,  a  dull  red.  The  copper  is  now  passed 
between  the  cylinders ;  but  although  this  metal  be  very  malleable,  the  ingots  cannot  be 
reduced  to  sheets  without  being  several  times  heated  ;  because  the  copper  cools,  and  ae 
quires,  by  compression,  a  texture  which  stops  the  progress  of  the  lamination. 

These  successive  heatings  are  given  in  the  furnace  indicated  above ;  though,  when  the 


i 


COPPER. 


477 


sheets  are  to  have  a  very  great  size,  furnaces  somewhat  dififerent  are  had  recourse  to. 
They  are  from  12  to  15  feet  long,  and  5  wide.    See  Brass.  ,     .  ^  r       a 

The  copper,  by  successive  heating  and  lamination,  gets  covered  with  a  co&i  o!  oxy^le^ 
which  is  removed  by  steeping  the  sheets  for  a  few  days  in  a  pit  filled  with  urine ;  they 
are  then  put  upon  the  sole  of  the  heating  furnace.  Ammonia  is  formed,  which  acts  on 
the  copper  oxyde,  and  lays  bare  the  metallic  surface.  The  sheets  are  next  rubbed  with 
a  piece  of  wood,  then  plunged,  whUe  still  hot,  into  water,  to  make  the  oxyde  scale  olT; 
vid  lastly,  they  are  passed  cold  through  the  rolling  press  to  smooth  them.  They  are  now 
tat  square,  and  packed  up  for  home  sale  or  exportation.  ,„,.,«  ♦    r 

The  following  estimate  has  been  given  by  MM.  Dufrenoy  and  Elie  de  Beaumont  of 
tte  expense  of  manufacturing  a  ton  of  copper  in  South  Wales. 

12|  tons  of  ore,  yielding  8|  per  cent,  of  copper  55 
20  tons  of  coals  -  -  -  -    8 

Workmen's  wages,  rent,  repairs,  &c.  -  -  13 


0 
0 
0 


d. 

0 
0 
0 


76    0    0 

The  exhalations  from  the  copper  smelting  works  are  very  detrimental  to  both  vegetaMe 
and  animal  life.  They  consist  of  sulphurous  acid,  sulphuric  acid,  arsenic,  and  arsenious 
acids  various  gases  and  fluoric  vapors,  with  solid  particles  mechanically  swept  away  into 
the  wr,  besides  the  coal  smoke.  Mr.  Vivian  has  invented  a  very  ingenious  method  of 
passing  the  exhalations  from  the  calcining  ores  and  malts  along  horizontal  flues,  or  rather 
galleries  of  great  dimensions,  with  many  crossings  and  windings  of  the  current,  and  ex- 
posure during  the  greater  part  of  the  circuit  to  copious  showers  of  cold  water.  By  this 
simple  and  powerful  system  of  condensation,  the  arsenic  is  deposited  in  the  bottoms  of 
the  flues,  the  sulphurous  acid  is  in  a  great  measure  absorbed,  and  the  nuisance  is  re- 
markably abated.  ^      .  ^    ^  ...  . 

The  following  figures  represent  certain  modifications  of  the  copper  calcining  and 
smelting  copper  furnaces  of  Swansea.  ^     ^^^    .x.  j    i 

Fig.  376,  is  the  section  of  the  roasting  furnace  lengthwise;  fig.  375,  the  ground  plan; 
in  which  a  is  the  fire-door;  b  the  grate;  c  the  fore-bridge;  d  the  chimney;  ee  working 
375  377 


apertures  on  each  of  the 
long  sides  of  the  furnace, 
through  which  the  ore  is  in- 
troduced, spread,  and  turned 
over ;  //  cast-iron  hoppers ; 
gg  openings  in  the  vaulted 
roof;  h  the  hearth-sole ;  i  i 
holes  in  this ;  fe  a  vaulted 
space  under  the  hearth.  The 
hearth  has  a  suitable  oval 
shape,  and  is  covered  with 
a  flat  arch.  Its  length  is 
16  feet,  breadth  13j^,  mean 

***JFi>  37?  U  a  longitudinal  section  of  the  melting  furnace ;  fig.  378,  the  ground  plan, 
in  whk  a'is  the  fire  door ;  b  the  grate ;  c  the  fire  biidge  j  d  the  chimney  ;e  the  side 
openings;/  the  working  doors;  g  the  raking-out  hole;  h  iron  spouts,  which  conduct 
the  melted  metal  into  pits  filled  with  water.  .,      ,,    i 

The  melting  furnace  is  altogether  smaller ;  but  its  firing  hearth  is  considerably  largef 


478 


COPPER. 


than  in  the  roasting  fbrnace.    The  long  axis  of  the  oval  hearth  is  14  feet ;  its  short 
JO  feet ;  its  mean  height  2  feet. 

878  

The  principal  ore  smelted  at  Chessy  is 
the  azure  copper,  which  was  discovered 
by  accident  in  1812.  Red  copper  ore,  also^ 
has  come  into  operation  there  since  1825. 
The  average  metallic  contents  of  the  richest 
azure  ore  are  from  33  to  36  per  cent. ;  of 
the  poorer,  from  20  to  24.  The  red  ore 
contains  from  40  to  67  parts  in  100.  The 
ore  is  sorted,  so  that  the  mean  contents  of 
metal  may  be  27  per  cent.,  to  which  20 
per  cent,  of  limestone  are  added  •  whence 
the  cinder  will  amount  to  60  per  xent.  of 
the  ore.  A  few  per  cents,  of  red  copper 
slag,  with  some  quicklime  and  gahrslag,  are 
added  to  each  charge,  which  consists  of 
200  pounds  of  the  above  mixture,  and 
,,  .  ,  ^50  pounds  of  coke.    When   the  furnace 

{fourneau  a  mancfu,  see  the  Scotch  smelting  hearth,  under  Lead)  is  in  good  action, 
from  10  to  14  such  charges  are  worked  in  12  hours.  When  the  crucible  is  fuU  of  metal 
at  the  end  of  this  period,  during  which  the  cinder  has  been  frequently  raked  off,  the  blast 
is  stopped,  and  the  matte  floating  over  the  metal  being  sprinkled  with  water  and  taken 
off,  leaves  the  black  copper  to  be  treated  in  a  similar  way,  and  converted  into  roHttts. 
The  refinmg  of  this  black  copper  is  performed  in  a  kind  of  reverberatory  furnace. 

The  cinders  produced  in  this  reduction  process  are  either  vitreous  and  light  blue, 
which  are  most  abundant ;  cellular,  black,  imperfectly  fused  from  excess  of  lime ;  or, 
lastly,  red,  dense,  blistery,  from  defect  of  lime,  from  too  much  heat,  and  the  passage  of 
proloxyde  mto  the  cinders.  They  consist  of  silicate  of  alumina,  of  lime,  protoxyde  of 
iron ;  the  red  contain  some  silicate  of  copper. 

The  copper-refining  fur- 
nace at  Chessy,  near  Ly- 
ons, is  of  the  kind  called 
Spleiss-o/en  (split  hearths) 
by  the  Germans.  Fig.  307 
is  a  section  lengthwise  ia 
the  dotted  line  a  b  of  Jig, 
380,  which  is  the  ground 
plan. 

The  foundation-walls  are 
made  of  gneiss;  the  arch, 
the  fire-bridge,  and  the 
chimney,  of  fire-bricks.  The 
hearth,  a,  is  formed  of  a 
dense  mixture  of  coal-dust, 
upon  a  bottom  of  well-beat 
clay,  6,  which  reposes  upon 
a  bed  of  brickwork  c.  Be« 
neath  this  there  is  a  slag 
bottom  d;  e  is  the  upper, 
and  /  the  under  discharge 
hole.  The  hearth  is  egg. 
shaped ;  the  longer  axis  be- 
ing 8  feet,  the  shorter  6| 

.    ,      J  J  r      •  L  J     ..,.   .^         ,  ^^^»  '"  ^^«  middle  it  is  10 

inch^  deep,  and  furnished  with  the  outlets  g  g,  which  lead  to  each  of  the  Spleus-hearth* 
h  h,fig,  380.  These  ouUets  are  contracted  with  fire-bricks  »  t,  till  the  proper  period  of 
the  discharge.  The  two  hearths  are  placed  in  communication  by  a  canal  k :  they  are  3* 
feet  m  diameter,  16  inches  deep ;  are  floored  with  weU-beat  coal  ashes,  and  receive  about 
27  cwt.  for  a  charge. 

lis  the  grate;  m,  the  fire-bridge;  n,  the  boshes  in  which  the  tuyeres  lie;  o,  the 
chimney;  p,  the  working  door  through  which  the  slags  may  be  drawn  off.  Above 
this  is  a  small  chimney,  to  carry  off  the  flame  and  smoke  whenever  the  door  ii 
opened. 

The  smelting  post  or  charge,  to  be  purified  at  once,  consists  of  60  cwt.  of  black 
copper,  to  which  a  little  granular  copper  and  copper  of  cementation  is  added  j  the 


COPPER. 


479 


sumption  of  pit-coal  amounts  to  36  cwt.     As  soon  as  the  copper  is  melted,  tht 
Wilows  are  set  a-going,  and  the  surface  of  the  metal  gets  soon  covered  with  • 

380 


moderately  thick  layer  of  cinder,  which  is  drawn  off.  This  is  the  first  skimming  or 
decrassage.  By  and  by,  a  second  layer  of  cinder  forms,  which  is  in  like  manner 
removed ;  and  this  skimming  is  repeated,  to  allow  the  blast  to  act  upon  fresh  metallic 
surfaces.  After  4  or  5  hours,  no  more  slag  appears,  and  then  the  fire  is  increased. 
The  melted  mass  now  begins  to  boil  or  work  {travaiUer),  and  continues  so  to  do,  for 
about  f  of  an  hour,  or  an  hour,  after  which  the  motion  ceases,  though  the  fire  be  kepC 
up.  The  gahrproof  is  now  taken ;  but  the  metal  is  seldom  fine  in  less  than  |  of  aq 
hour  after  the  boil  is  over.  Whenever  the  metal  is  run  off  by  the  tap-hole  into  the 
two  basins  i  t,  called  split-hearths,  a  reddish  vapor  or  mist  rises  from  its  surface, 
composed  of  an  infinite  number  of  minute  globules,  which  revolve  with  astonishing 
velocity  upon  their  axes,  constituting  what  the  Germans  called  spratzen  (crackling)  of 
the  copper.  They  are  composed  of  a  nucleus  of  metal,  covered  with  a  film  of  protoxyde, 
and  are  used  as  sand  for  strewing  upon  manuscript.  The  copper  is  separated,  as  usual,  by 
sprinkling  water  upon  the  surface  of  the  melted  metal,  in  the  state  of  rosettes,  which  are 
immediately  immersed  in  a  stream  of  water.  This  refining  process  lasts  about  16  or  17 
hours ;  the  skimmings  weigh  about  50  cwt.  ;  the  refuse  is  from  15  to  17  per  cent.  ;  the 
loss  from  2  to  3  per  cent.    The  gahrslag  amounts  to  11  cwt. 

The  refining  of  the  eliquated  copper  (called  darrlinge)  from  which  the  silver  has  been 
sweated  out  by  the  intervention  of  lead,  can  be  performed  only  in  small  hearths.  The 
ibilowing  is  the  representation  of  such  a  furnace,  called,  in  German,  Kupfergahrheerd, 
Fig,  381  is  the  section  lengthwise  ;  Jig.  382  is  the  section  across ;   and  Jig,  383  is  the 


381 


383 


1 


frmind  plan,  in  which  a  is  the  hearth-hollow;  b,  a  massive  wall;   c,  the  mass  out  cf 
Irtldi  the  hearth  is  formed;   d,  cast-iron  plates  covering  the  hearth;   e,  opening  fjt 


480 


COPPER. 


COPPER. 


481 


I 


njnning  otf  the   liquid  slag;  /,  a  small   waU;    g,  iron  curb  for  keeping  the  eoidi 

The  hearth  being  heated  with  a  bed  of  charcoal,  {  cwt.  of  darrlinge  are  laid  over  it, 
and  covered  with  more  fuel :  whenever  this  charge  is  melted,  another  layer  of  the  coaJ 
and  darrlinge  is  introduced,  and  thus  in  succession  till  the  hearth  become  full  or 
contain  from  2^  to  2J  cwt.  In  Neustadt  7^  cwt.  of  darrlinge  have  been  refined  in  one 
furnace,  from  which  5  cwt.  of  gahrcopper  has  been  obtained.  The  blast  oxydizes  the 
foreign  metal?,  namely,  the  lead,  nickel,  cobalt,  and  iron,  with  a  little  copper,  forming 
the  gahrslag ;  which  is,  at  first,  rich  in  lead  oxyde,  and  poor  in  copper  oxyde ;  but  at  the 
end,  this  order  is  reversed.  The  slag,  at  first  blackish,  assumes  progressively  a  copper 
red  tint.  The  slag  flows  off  spontaneously  along  the  channel  «,  from  the  surface  of  the 
hearth.  The  gahre  is  tested  by  means  of  a  proof-rod  of  iron,  called  gahr-eisen.  thrust 
though  the  luylre  into  the  melted  copper,  then  drawn  out  and  plunged  in  cold  water. 
As  soon  as  the  gahrspan  (scale  of  copper)  appears  brownish  red  on  the  outside,  and 
copper  red  within,  so  thin  that  it  seems  like  a  net-vork,  and  so  deficient  in  tenacity 
that  It  cannot  be  bent  without  breaking,  the  refining  is  finished.  The  blast  is  then 
stopped ;  the  coals  covering  the  surface,  as  also  the  cinders,  must  be  raked  oflf  the  copper, 
alter  bemg  left  to  cool  a  little;  the  surface  is  now  cooled  by  sprinkling  water  upon  it, 
and  the  thick  cake  of  congealed  metal  (rondelle)  is  lifted  off  with  longs,  a  process  called 
•chUissen  (shcmg),  or  sheibenreissen  (shaving),  which  is  continued  till  the  last  convex  cake 
at  the  bottom  of  the  furnace,  styled  the  kingspiece,  is  withdrawn.  These  rondelles  are 
immediately  immersed  in  cold  water,  to  prevent  the  oxydation  of  the  copper ;  whereupon 
the  metal  becomes  of  a  cochineal  red  color,  and  gets  covered  with  a  thin  film  of 
protoxyde.  Its  under  surface  is  studded  over  with  points  and  hooks,  the  result  of 
tearing  the  congealed  disc  from  the  liquid  metal.  Such  cakes  are  called  rosette  copper. 
When  the  metal  is  very  pure  and  free  from  protoxyde,  these  cakes  may  be  obtained  very 
thin,  one  24th  of  an  inch  for  example. 

The  refining  of  two  cwts.  and  a  half  of  darrlinge  takes  three  quarters  of  an  hour,  and 
yields  one  cwt.  and  a  half  of  gahrcopper  in  36  rosettes,  as  also  some  gahrslag.  Gahr- 
copper generally  contains  from  IJ  to  2|  per  cent,  of  lead,  along  with  a  little  nickel, 
silver,  iron,  and  aluminum. 

Smelting  of  the  Mann^feld  copper  schist^  or  bituminous  Mergelachiefer.— The  cupreous 
ore  is  first  roasted  in  large  heaps,  of  2000  cwts.,  interstratified  with  brush-wood  and 
with  some  slates  rich  in  bituminous  matter,  mixed  with  the  others.  These  heaps  arc 
3  ells  high,  and  go  on  burning  15  weeks  in  fair  and  20  in  rainy  weather.  The  bitumen 
IS  decomposed  ;  the  sulphur  is  dissipated  chiefly  in  the  form  of  sulphurous  acid  ;  the  metal 
gets  partially  oxydized,  particularly  the  iron,  which  is  a  very  desirable  circumstance 
towards  the  production  of  a  good  smelting  slag.  The  calcined  ore  is  diminished  one 
tenth  in  bulk,  and  one  eighth  in  weight ;  becoming  of  a  friable  texture  and  a  dirty  yellow 
gray  color.  The  smelting  furnaces  are  cupolas  (schachtofen) ,  14  to  18  feet  high;  the 
fuel  is  partly  wood  charcoal,  partly  coke  from  the  Berlin  gas-works,  and  Silesia.  'The 
blast  is  given  by  cylinder  bellows,  recently  substituted  for  the  old  barbarous  Blasebdleen 
or  wooden  bellows  of  the  household  form. 

The  cupreous  slate  is  sorted,  according  to  its  composition,  into  slate  of  lime,  clay,  iron, 
&c.,  by  a  mixture  of  which  the  smelting  is  facilitated.  For  example,  1  post  or  charge  may 
consist  of  20  cwt.  of  the  ferruginous  slate,  14  of  the  calcareous,  6  of  the  argillaceous,  with 
3  of  fluor  spar,  3  of  rich  copper  slags,  and  other  refuse  matters.  The  nozzle  at  the 
tuylre  is  lengthened  6  or  8  inches,  to  place  the  melting  heat  near  the  centre  of  the 
furnace.  In  15  hours  1  fodder  of  48  cwts.  of  the  above  mixture  may  be  smelted, 
whereby  4  to  5  cwts.  of  maiie  (crude  copper,  called  Kupferstein  in  Germany)  and  a 
laije  body  of  slags  are  obtained.  The  matte  contains  from  30  to  40  per  cent,  of  copper 
and  from  2  to  4  lo/hs  (1  to  2  oz.  )  of  silver.  The  slags  contain  at  times  one  tenth  theii 
weight  of  copper. 

The  rnatte  is  composed  of  the  sulphurets  of  copper,  iron,  silver,  zinc,  along  with  some 
arsenical  cobalt  and  nickei.  The  slaty  slag  is  raked  off  the  surface  of  the  melted  mattt 
from  time  to  time.  The  former  is  either  after  being  roasted  six  successive  times, 
smelted  into  black  copper;  or  it  is  subje^'ted  to  the  following  concentration  process.  It 
IS  broken  to  pieces,  roasted  by  brushwood  and  coals  three  several  tunes  in  brick-walled 
kilns,  containing  60  cwts.,  and  turned  over  aAer  every  calcination ;  a  process  of  four 
weeks'  duration.  The  ihrice  roasted  mass,  called  spurrost,  being  melted  in  the  cupola 
fig'  385,  with  ore-cinder,  yields  the  spurstein,  or  concentrated  matte.  From  30  to  40  cwts. 
of  spurrost  are  smelted  in  24  hours ;  and  from  48  to  60  per  cent,  of  spurstein  are  obtained, 
the  slag  from  the  slate  smelting  being  employed  as  a  flux.  The  spurstein  contains  from 
60  to  60  per  cent,  of  copper,  combined  with  the  sulphurets  of  copper,  of  iron,  and 

The  spurstein  is  now  mixed  with  dunnstein  (a  sulphuret  of  copper  and  iron  produced 
in  the  original  smeltings)  roasted  six  successive  times,  in  the  quantity  of  60  cwts.,  with 


) 


hrushwood  and  charcoal;  a  process  which  requires  from  7  to  8  weeks.  The  product  of 
this  six-fold  calcination  is  the  Gahrrost  of  the  Germans  (done  and  purified) ;  it  has  a 
color  like  red  copper  ore,  varying  from  blue  gray  into  cochineal  red  ;  a  granular  frac- 
ture; it  contains  a  little  of  the  metal,  and  may  be  immediately  reduced  into  metallic 
copper,  called  kupfermachen.  But  before  smelling  the  mass,  it  is  lixiviated  with  water, 
to  extract  from  it  the  soluble  sulphate,  which  is  concentrated  in  lead  pans,  and  crys- 
tallized. 

The  lixiviated  gahroste  mixed  with  from  *  to  1  of  the  lixiviated  dunnsteinrost,  and  ^  to  ^ 
of  the  copper  slate  slag,  are  smelted  with  charcoal  or  coke  fuel  in  the  course  of  24  hours, 
in  a  mass  of  60  or  80  cwts.  The  product  is  black  copper,  to  the  amount  of  about  J  the 
weight,  and  i  of  dunnstein  or  thin  matte.  This  black  copper  contains  in  the  cwt.  from 
12  to  20  loths  (6  to  10  oz.)  of  silver.  The  dunnstein  consists  of  from  60  to  70  per  cent, 
of  copper  combined  with  sulphur,  sulphuret  of  iron,  and  arsenic;  and  when  thrice 
roasted,  yields  a  portion  of  metal.  The  black  copper  lies  undermost  in  the  crucible  of 
the  furnace ;  above  it  is  the  dilnn^teinf  covered  with  the  stone  slag,  or  copper  cinder, 
resulting  from  the  slate-smelling.  The  slags  being  raked  off,  and  the  crucible  sufficiently 
full,  the  eye  or  nozzle  hole  is  shut,  the  dunnstein  removed  by  cooling  the  surface  and 
breaking  the  crust,  which  is  about  \\o\  inch  thick.  The  same  method  is  adopted  for 
taking  out  the  black  copper  in  successive  layers.  For  the  de-silvering  of  this  and  similar 
black  coppers,  see  Silver. 

384  Fig,  384  is  a  vertical  section 

through  the  form  or  tuyere  in 
the  dotted  line  a  b  of  yig.  386. 
Fig.  385  is  a  vertical  section  in 
the  dotted  line  c  d  of^g.  387.  a 
is  the  shaft  of  the  furnace,  b  the 
rest,  c  c  the  forms ;  d  the  sole  or 
hearth-stone,  which  has  a  slope 
of  3  inches  towards  the  front 
wall ;  €  e,  &c.  casing  walls  of  fire 
bricks ;  //,  &c.  filling  up  walls 
built  of  rubbish  stones  \  g  g  ^ 
mass  through  which  the  heat  is 
slowly  conducted  ;  h  h  the  two 
holes  through  one  or  other  of 
which  alternately  the  product  of 
the  smelting  process  is  run  off 
into  the  fore-hearth.  Beneatk 
the  hearth-sole  there  is  a  soW 
body  of  loam ;  and  the  fore- 
hearth  is  formed  with  a  mixture 
of  coal-dust  and  clay ;  k  is  the 
discharge  outlet.  Fig.  386  is  a 
horizontal  section  of  the  furnace 
through  the  hole  or  eye  in  the 
dotted  line  e  f  oTJig.  384 ;  fig. 
387,  a  horizontal  section  of  the 
shaft  of  the  furnace  through  the 
form  in  the  doited  line  g  h  of  figs.  384  and  385.  The  height  of  the  shaft,  from  the  line 
E  F  to  the  top,  is  14  feet ;  from  e  to  g,  25  inches ;  from  c  to  the  line  below  6,  2  feet ; 
from  that  line  to  the  line  opposite  g  g,  2  feet.  The  width  at  the  line  g  g  is  3  feet  3  inchcb, 
and  at  c  26  inches.    The  basins  i  i,fig.  386,  are  3  feet  diameter,  and  20  inches  deep. 

The  refining  of  copper  is  said  to  be  well  executed  at  Seville,  in  Spain ;  and,  therefore, 
some  account  of  the  mode  of  operating  there  may  be  acceptable  to  the  reader. 

The  first  object  is  to  evaporate  in  a  reverberatory  furnace  all  the  volatile  substantes, 
such  as  sulphur,  arsenic,  antimony,  &c.,  which  may  be  associated  with  the  sulphur;  ani 
the  second,  to  ox}'dize  and  to  convert  into  scoriae  the  fixed  substances,  such  as  iron,  lead, 
&c.,  with  the  least  possible  expense  and  waste.  The  minute  quantities  of  gold  and  sil- 
ver which  resist  oxydation  cannot  be  in  any  way  injurious  to  the  copper.  The  hearth 
is  usually  made  of  a  refractory  sand  and  clay  with  ground  charcoal,  each  mixed  in  equal 
volumes,  and  worked  up  into  a  doughy  consistence  with  water.  This  composition  is 
beat  firmly  into  the  furnace  bottom.  But  a  quartzose  hearth  is  found  to  answer  better, 
and  to  be  far  more  durable ;  such  as  a  bed  of  fire-sandstone. 

Before  kindling  the  furnace,  its  inner  surface  is  smeared  over  with  a  cream-con- 
sistenced  mixture  of  fire-clay  and  water. 

The  cast  pigs,  or  blocks  of  black  or  crude  copper,  are  piled  upon  the  hearth,  each  suc- 
cessive layer  crossing  at  right  angles  the  layer  beneath  it,  in  order  that  the  flame  maj 

31 


f 


462 


COPPFJL 


COFFiiK. 


483 


The  weight  of  the  charge  should  be  proportional  to  the  capacity  of  the  furnace  »n3 
such  that  the  level  of  the  metallic  bath  may  be  about  an  inch  alLve  the  nozzle  of  the 
bellows ;  for,  were  it  higher,  it  would  obstruct  its  operation,  and  were  it  too  low  the 
stream  of  air  wo.ild  strike  but  imperfectly  the  surface  of  the  metal,  and  would  fail  to 

^nl^/in '  T.'i  r'^'"^  *'  }?'-'  ^'''  7^"^"^  P'°"'''  ^y  **^*^i»S  »»»«  oxydation  and  vola^ 
liiization  of  the  foreign  metals  incomplete. 

the^U'o'f  rwi^d/rr^d!'"  '''  '"^''''  ''^^  ""''  '"^"^  ^^^^^^  ^^  ^"^  ^«^"«  ^-^  'o 
wf^lLm"nl«I;''^  copper  is  melted,  charcoal  is  to  be  kindled  in  three  iron  basins  lined 
Tnlr  T^^l  •  ^  alongside  the  furnace,  to  prepare  them  for  receiving  their  charge  o? 
copper,  whirh  is  to  be  converted  in  them,  into  rosettes.  ^ 

IS  ^coS-'^^L^tn  ^l^?K^'^rr -.f'"^^^^  "'^•"^'•^l  substances 

IS  so  cojMou.,  as  to  give  the  bath  a  boiling  appearance ;  some  drops  rise  up  to  the  roof 

giobule*.  This  phenomenon  proves  that  the  process  is  Roing  on  well ;  and  when  it 
ceases,  the  operatujn  is  nearly  completed.     A  small  proof  of  cSpp^r,  of    he  fo'rm  of  a 

end  ofa  polished  iron  roa,  previously  heated.  This  rod  is  dipped  two  or  three  inXS 
into  the  bath,  then  withdrawn  and  immersed  in  cold  water.    ThVcopper  ?ap  is  detaclel 

n?sT  (^loHnTtr'  h'  ^'^.""''r  f  "  '"T" '  '^"^  ^  ^^'^'-'  hfoZ.TLl  Us  thick- 
ness, color,  and  polish,  as  to  the  degree  of  purity  which  the  coDoer  has  acnnirprf     S.it 

AtThe7nforar„'t"n  I'  '^^""r  f'- '''  T^^  ^^"^  above  sHrrof,t?cr:^';o  ^ 
tJ.h\  o^  about  11  hours  of  finng,  the  numerous  small  holes  otiervable  in  the  first 
«.cr/cA  samples  begin  to  disappear;  the  outer  surface  passes  from  a  bright  red  to  adark^ 
hue  the. nner  one  becomes  of  a  more  uniform  color,  and  always  Jess"' and  lei  markS 
with  ye  lowish  spots  It  will  have  acquired  the  greatest  pitch  of  purity  that  the  ZcSs 
can  bestow,  when  the  watches  become  of  a  dark  crimson  color  ^  ^^^ 

ino  nn°!''f  ^^  ^*^^n  ^"^  '^''P  ^^'l  ^^^'"'''^  P'^^*^^^^  «^  ^^^  P'-oper  time;  for,  by  prolon- 
ing  It  unduly  a  small  quantity  of  cupreous  oxyde  would  be  formed,  which  findin- no 

oFSnatLl"'  '''  ""''  ""'"  ''^  "'"^^^  ^'y  ^'^°PP^^  *>-^'  br7ttTe,  and'ntye 
mnTI't  ^^?'"%™"st  "ow  be  emptied  of  their  burning  charcoal,  the  opening  of  the  tuyere 
Shi  •  ^  °^^'^',^"d;»^«.  ?^''«d  copper  allowed  to  flow  into  Ihem  through  The  tarSe 
which  IS  then  closed  w.th  loam.    Whenever  the  surface  is  covered  with  a  solid  cr^sTiJ 

L^f^Z^  Z'i^  r-"''  ^"^  ?'  ^°^"  ^'  '^^  ^"-"^^  '^  «»^«t  ]i  inch  thick  it  is  rated  upon 
hooks  above  the  bas.n,  to  drain  off  any  drops,  and  then  carried  away  from  the  furnaT 
If  these  cakes,  or  rosettes,  be  suddenly  cooled  by  plunging  them  immedktely  in  watS* 
they  will  assume  a  fine  red  color,  from  the  formation  of  a  film  of  oxTe         ^  ' 

sumjt 'on'o'fXVt^^^^^^^^^^^^  ''  '^^^^  ^ A  ^^  o^-pper,  with  the  con- 

it  into  wt'j^r ^Ith^  '^^^"^  ^^^^  ^?^  ^^PP^"  *^^*  ''^  "^^^"^  ^  «"  solidified  before  plunging 
i  iJln  '  ^fherwise  a  very  dangerous  explosion  might  ensue,  in  consequence  of   hi 

^t  V'TT'''''.''^  °*y^^''  ^"^"^  ^^^  ^'^^'^  ^^'al,  in  the  act  of  condensation  On  he 
other  hand,  the  cake  should  not  be  allowed  to  cool  too  long  in  the  aiV,  kst  it  L  neroxv 

Se^S^Stox^dr  wh"'h'"'  ''''}''T  '".^  ^^'  P"^P^^'  -^  yell';  shLdS  duf  toTfi^' 
oi  uie  piotoxyde,  which  manv  dealers  admire. 

they  (S^casion^'tL'^n '  ""^  ^"'^7"^-  '"'*  ^^^^^  ^^  ^«PP^  "«  *^«'"^''»^  ^'^^  copper, 
fa  harTb   me  vplK-  r"wt''^  micaceous  scales  in  the  fractured  faces.     Such  meta 

defects  ^renol^ow't/''^'"*-  ^"^  '^"  ^t  ""^'^"  ^«"'"»^^  "«^  wire-drawn.  These 
.Snvln  thpZ«J%Ih-\''-"'''  ^'.'^''  ^"'""^'^^  imagined;    but,  most  probably,  to 

According  to  M.  Frerejean,  proprietor  of  the  great  copper  works  of  Vienne  in 
Dauphiny,  too  low  a  temperature,  or  too  much  chlrcoal,  gi'JS  trthe  metalTcub.>^ 
structure,  or  that  of  divergent  rays;  in  either  of  which   iTteT it  wants  tenLV'^^ 

lre^lTlr;:e^^"^rs^:^^ 

these  three  states  in  the  space  of  ten  minutes  ^uccess^veiy  mrougn 

wh^^'  f  L?tJ  T  nf th*  ''"^''l"^  '^''^'^f  coppe;  pyrites  in  the  Lower  Hartz,  near  Goslar, 
nr^!Z^.T  I''  A  ^iP*""'  '%  collected.     It  is  a  vertical  section  of  a  truncated 

2,  thT^e  a  Z  ^^"       ^"^"'^  ^^'''  ''  "^"^^"^  *'  '^'  ^^  ^^'^'  Py '«°»W 


c,  a  wooden  chimney  which  stands  in  the  centre  of  the  mound  with  a  small  pile  ci 
charcoal  at  itj?  bottom,  c;  d  d  are  large  lumps  of  ore  surrounded  by  smaller  pieces;  // 

are  rubbish  and  earth  to  form  a  covering 
A  current  of  air  is  admitted  under  the 
billets  by  an  opening  in  the  middle  of 
each  of  the  four  sides  of  the  base  a  a, 
so  that  two  principal  currents  of  air 
cross  under  the  vertical  axis  c  of  the 
truncated  pyramid,  as  indicated  in  the 
figure. 

The  fire  is  applied  through  the  chimney  c  ;  the  ciiarcoal  at  its  bottom  c,  and  the  piles 
a  a  are  kindled.  The  sulphureous  ores,  d  /,  are  raised  to  such  a  high  temperature  as 
to  expel  the  sulphur  in  the  state  of  vapor. 

In  the  Lower  Hartz  a  roasting  mound  continues  burning  during  four  months.  Some 
days  after  it  is  kindled  the  sulphur  begins  to  exhale,  and  is  condensed  by  the  air  at  the 
upper  surface  of  the  pyramid.  When  this  seems  impregnated  with  it,  small  basins  1  1 
are  excavated,  in  which  some  liquid  sulphur  collects;  it  is  removed  from  lime  to  time 
with  iron  ladles,  and  thrown  into  water,  where  it  solidifies.  It  is  then  refined  and  cast 
into  roll  brimstone. 

A  similar  roasting  mound  contains,  in  the  Lower  Hartz,  from  100  to  liO  tons  of  ore 
and  730  cubic  feet  of  wood.  It  yields  in  four  months  about  one  ton  and  a  half  of 
sulphur  from  copper  pyrites.  Lead  ore  is  treated  in  the  same  way,  but  it  furnishes  less 
sulphur. 

There  are  usually  from  12  to  15  roasting  heaps  in  action  at  once  for  three  smelting 
works  of  the  Lower  Hartz.  After  the  first  roasting  two  heaps  are  united  to  form  a  third, 
which  is  calcined  anew,  but  under  a  shed;  the  ores  are  then  stirred  up  and  roasted  for 
the  third  time,  whence  a  crude  mixture  is  procured  for  the  smelting-house. 

The  most  favorable  seasons  for  roasting  in  the  open  air  are  spring  and  autumn  ;  the 
best  weather  is  a  light  wind  accompanied  with  gentle  rain.  When  the  wind  or  rain 
obstructs  the  operation,  this  inconvenience  is  remedied  by  planks  distributed  round  the 
upper  surface  of  the  truncated  pyramid  over  the  sulphur  basins. 

Manufacturing  assays  of  copper. — The  first  thing  is  to  make  such  a  sample  as  will 
represent  the  whole  mass  to  be  valued ;  with  which  view,  fragments  must  be  taken  from 
different  spots,  mixed,  weighed,  and  ground  together.  A  portion  of  this  mixture  being 
tried  by  the  blow-pipe,  will  show,  by  the  garlic  or  sulphurous  smell  of  its  fumes,  whether 
arsenic,  sulphur,  or  both,  be  the  mineralizers.  In  the  latter  case,  which  often  occurs, 
100  gr.  or  1000  gr.  of  the  ore  are  to  be  mixed  with  one  half  its  weight  of  saw-dust, 
then  imbued  with  oil,  and  heated  moderately  in  a  crucible  till  all  the  arsenical  fumes  be 
dissipated.  The  residuum,  being  cooled  and  triturated,  is  to  be  exposed  in  a  shallow 
earthen  cup  to  a  slow  roasting  heat,  till  the  sulphur  and  charcoal  be  burned  away.  What 
remains,  being  ground  and  mixed  with  half  its  weight  of  calcined  borax,  one  twelfth  its 
weight  of  lamp  black,  next  made  into  a  dough  with  a  few  drops  of  oil,  is  to  be  pressed 
down  into  a  crucible,  which  is  to  be  covered  with  a  luted  lid,  and  to  be  subjected,  in  a 
powerful  air  furnace,  first  to  a  dull  red  heat,  and  then  to  vivid  ignition  for  20  minutes. 
On  cooling  and  breaking  the  crucible,  a  button  of  metallic  copper  will  be  obtained.  Its 
color  and  malleability  indicate  pretly  well  the  quality,  as  does  its  weight  the  relative 
value  of  the  ore.  It  should  be  cupelled  with  lead,  to  ascertain  if  it  contains  silver  or 
gold.     See  Assay,  and  Silver. 

If  the  blow-pipe  trial  showed  no  arsenic,  the  first  calcination  may  be  omitted ;  apff  if 
neither  sulphur  nor  arsenic,  a  portion  of  the  ground  ore  should  be  dried,  and  treated 
directly  with  borax,  lamp-black,  and  oil.  It  is  very  common  to  n  ake  a  urv  assay  of 
copper  ores,  by  one  roasting  and  one  fusion  along  with  3  parts  of  black  fl'i\  :  Irom  m*. 
weight  of  the  metallic  button  the  richness  of  the  ore  is  inferred. 
The  humid  assay  is  more  exact,  but  it  requires  more  skill  and  time. 
The  sulphur  and  the  silica  are  easily  got  rid  of  by  the  acids,  which  do  not  dissolve 
them,  but  only  the  metallic  oxydes  and  the  other  earths.  These  oxydes  may  then  be 
thrown  down  by  their  appropriate  reagents,  the  copper  being  precipitated  in  the  state  of 
cither  the  black  oxyde  or  jmre  metal.  105  parts  of  black  oxyde  represent  ICO  of  copper. 
Before  entering  upon  the  complete  analysis  of  an  ore,  preliminary  trials  should  be  made, 
to  ascertain  what  are  its  chief  constituents.  If  it  be  sulphuret  of  copper,  or  coppei 
pyrites,  without  silver  or  lead,  100  grains  exactly  of  its  average  powder  may  be  weighed 
out,  treated  in  a  matrass  with  boiling  muriatic  acid  for  some  time,  gradually  adding  a  few 
drops  of  nitric  acid,  till  all  action  ceases,  or  tiU  the  ore  be  all  dissolved.  The  insoluble 
matter  found  floating  in  the  liquid  contains  most  of  the  sulphur;  it  may  be  separated 
upon  a  filter,  washed,  dried,  and  weighed  ;  then  verified  by  burning  away.  The  incom- 
bustible residuum,  treated  by  muriatic  acid,  may  leave  an  insoluble  deposite,  which  is 
to  be  added  to  the  former.    To  the  whole  of  the  filtered  solutions  carbonate  of  potash  if 


I'* 


f- ' 


484 


COPPER. 


to  be  added ;  and  the  resulting  precipitate,  being  washed,  and  digested  repeatedly  in  wa« 
ter  of  ammonia,  all  its  cupric  oxyde  will  have  been  dissolved,  whenever  the  ammonia  i$ 
ro  longer  rendered  blue. 

Caustic  potash,  boiled  with  the  ammoniacal  solution,  will  separate  the  copper  in  the 
state  of  black  oxyde ;  which  is  to  be  thrown  upon  a  filter,  washed,  dried,  and  wei?hed. 
The  matter  lefk  undissolved  by  the  ammonia,  consists  of  oxyde  of  iron,  with  probably  a 
little  alumina.  The  latter  being  separated  by  caustic  potash,  the  iron  oxyde  maybe  also 
washed,  dried,  and  weighed.  The  powder  which  originally  resisted  the  muriatic  acid,  is 
silica. 
jSssay  of  copper  ores,  which  contain  iron^  sulphur,  silver,  had,  and  antimony, 
100  grains  of  these  ores,  previously  sampled,  and  pulverized,  are  to  be  boiled  with 
nitric  acid,  adding  fresh  portions  of  it  from  lime  to  time,  till  no  more  of  the  matter  be 
dissolved.  The  whole  liquors  which  have  been  successively  digested  and  decanted  uff. 
are  to  be  filtered  and  treated  with  common  salt,  to  precipitate  the  silver  in  the  state  of  a 
chloride. 

The  nitric  acid,  by  its  reaction  upon  the  sulphur,  having  generated  sulphuric  acid,  this 
will  combme  with  the  lead  oxydized  at  the  same  time,  constituting  insoluble  sulphate  of 
lead,  which  will  remain  mixed  with  the  gangue.  Should  a  little  nitrate  of  lead  remain 
in  the  liquid,  it  may  be  thrown  down  by  sulphate  of  soda,  after  the  silver  has  been  sepa- 
rated. The  dilute  liquid,  being  concentrated  by  evaporation,  is  to  be  mixed  with  ammo- 
nia m  such  excess  as  to  dissolve  all  the  cupric  oxyde,  while  it  throws  down  all  the  oxyde 
of  iron  and  alumina ;  which  two  may  be  separated,  as  usual,  by  a  little  caustic  pot- 
ash. The  portion  of  ore  insoluble  in  the  nitric  acid  being  digested  in  muriatic  acid, 
everything  will  be  dissolved  except  the  sulphur  and  silica.  These  being  collected  upon 
a  filter,  and  dried,  the  sulphur  may  be  burned  away,  whereby  the  proportion  of  each  is 
determined. 

Ores  of  the  oxyde  of  copper  are  easily  analyzed  by  solution  in  nitric  acid,  the  addition 
of  ammonia,  to  separate  the  other  metals,  and  precipitation  by  potash.  The  native  car- 
bonate  is  analyzed  by  calcining  100  grains ;  when  the  loss  of  weight  will  show  the 
amount  of  water  and  carbonic  acid ;  then  that  of  the  latter  may  be  found,  by  expelling  it 
from  another  100  grains,  by  digestion  in  a  given  weight  of  sulphuric  acid.  The  copper 
IS  finally  obtained  in  a  metaUic  state  by  plunging  bars  of  zinc  into  the  solution  of  the 
sulphate. 

The  native  arseniates  of  copper  are  analyzed  by  drying  them  first  at  a  moderate  heat; 
after  which  they  are  to  be  dissolved  in  nitric  acil.  To  this  solution,  one  of  nitrate  of 
lead  is  to  be  added,  as  long  as  it  occasions  a  precipitate ;  the  deposite  is  to  be  drained  up- 
on a  filter,  and  the  clear  liquid  which  passes  through,  being  evaporated  nearly  to  drvness 
IS  to  be  digested  in  hot  alcohol,  which  will  dissolve  everything  except  a  little  arseniateof 
lead.  This  being  added  to  'lie  arseniate  first  obtained,  from  the  weight  of  the  whole,  the 
arsenic  acid,  constituting  35  per  cent.,  is  directly  inferred.  The  alcoholic  solution  bein" 
now  evaporated  to  dryness,  the  residue  is  to  be  digested  in  water  of  ammonia,  when  the 
cupric  oxyde  will  be  dissolved,  and  the  oxyde  of  iron  will  remain.  The  copper  is  procured, 
m  the  state  of  black  oxyde,  by  boiling  the  filtered  ammoniacal  solution  with  the  proper 
quantity  of  potash. 

The  analysis  of  muriate  of  copper— atacamite— is  an  easy  process.  The  ore  being 
dissolved  in  nitric  acid,  a  solution  of  nitrate  silver  is  added,  and  from  the  weight  of  the 
chloride  precipitated,  the  equivalent  amount  of  muriate  or  chloride  of  copper  is  given  ;  for 
100  of  chloride  of  silver  represent  93  of  chloride  of  copper,  and  43-8  of  its  metallic  basis. 
I  his  calculation  may  be  verified  by  precipitating  the  copper  of  the  muriate  from  its  solu- 
tion in  dilute  sulphuric  acid,  by  plates  of  zinc. 

The  phosphate  of  copper  may  be  analyzed  either  by  solution  in  nitric  acid,  and  precipi- 
tation by  potash  ;  or  by  precipitating  the  phosphoric  acid  present,  by  means  of  acetate  of 
lead.  Ihe  phosphate  of  lead  thus  obtained,  after  being  washed,  is  to  be  decomposed  by 
dilute  sulphuric  acid.  The  insoluble  sulphate  of  lead,  being  washed,  dried,  and  weighed, 
indicates  by  Its  equivalent  the  proportion  of  phosphate  of  lead,  as  also  of  phosphate  of 
copper;  lor  100  of  sulphate  of  lead  correspond  to  92-25  phosphate  of  lead,  and  89-5  pho»- 
phate  of  copper ;  and  this  again  to  52-7  of  the  black  oxyde. 

Copper  forms  the  ba-is  of  a  greater  number  of  important' alloys  than  any  other  metal. 
With  zmc.  It  forms  Brass  m  all  its  varieties;  which  see. 

Bronze  and  Bell  Metal  are  alloys  of  copper  and  tin.  This  compound  is  prepared  in 
crucibles  when  only  small  quantities  are  required ;  but  in  reverberatory  hearths,  when 
statues,  bells,  or  cannons  are  to  be  cast.  The  metals  must  be  protected  as  much  as  pos- 
sible  during  their  combination  from  contact  of  air  by  a  layer  of  pounded  charcoal,  other- 
'Vise  two  evils  would  result,  waste  of  the  copper  by  combustion,  and  a  rapid  oxydizement 
«f  the  tin,  so  as  to  change  the  proportions  and  alter  the  properties  of  the  alloy.  The  fused 
materials  ought  to  be  well  mixed  by  stirring,  to  give  uniformity  to  the  compound.    See 

OAONZE. 


rii_, 


COPPER. 


r 


i 


485 


An  ailoy  of  100  of  copper  and  4*17  of  tin  hag  been  proposed  by  M.  Cftaudei  for  ihz 
ready  manutaciure  of  medals.  After  melting  this  aUoy,  he  casts  it  in  moulds  made  of 
such  bone-ash  as  is  used  for  cupels.  The  medals  are  afterward  subjected  to  the  action 
of  the  .^oining  press,  not  for  striking  them,  for  the  mould  furnishes  perfect  impressions, 
but  for  linishing  and  polishing  them. 

By  a  recent  analysis  of  M.  Berthier,  the  bells  of  the  penduks,  or  ornamental  clocks, 
made  in  Paris,  are  found  to  be  composed— of  copper  72-00,  tin  26-56,  iron  1*44,  in  100 
parts. 

An  alloy  of  100  of  copper  and  14  of  tin  is  said  by  M.  Dussaussy  to  furnish  tools,  which, 
hardened  and  sharpened  in  the  manner  of  the  ancients,  aflx)rd  an  edge  nearly  equal  to 
that  of  steel. 

Cymbals,  gongs,  and  the  tamtam  of  the  Chinese  are  made  of  an  alloy  of  100  of  copper 
with  about  25  of  tin.  To  give  this  compound  the  sonorous  propertv  in  the  highest  de- 
gree, it  must  be  subjected  to  sudden  refrigeration.  M.  D'Arcet,  to  whom  this  di«:coverT 
IS  due,  recommends  to  ignite  the  piece  after  it  is  cast,  and  to  plunge  it  immediately  into 
cold  water.  The  sudden  cooling  Rives  the  particles  of  the  alloy  such  a  disposition, 
that,  with  a  regulated  pressure  by  skilful  hammerins,  they  may  be  made  to  slide  over  each 
other,  and  remain  permanently  in  their  new  position.  When  by  this  means  the  instru- 
ment has  received  its  intended  form,  it  is  to  be  heated  and  allowed  to  cool  slowly  in  the 
air.  The  particles  now  take  a  different  arrangement  from  what  they  would  have  done 
by  sudden  refrigeration ;  for  instead  of  being  ductile,  they  possess  such  an  elasticity, 
that  on  being  displaced  by  a  slight  compression,  they  return  to  their  primary  position 
after  a  series  of  extremely  rapid  vibrations ;  whence  a  very  powerful  sound  is  emitted 
Bronze,  bell-metal,  and  probably  all  the  other  alloys  of  tin  with  copper,  present  the  same 

The  alloy  of  100  of  copper  with  from  60  to  33  of  tin  forms  common  bell-metal     It  is 
yellowish  or  whitish  gray,  brittle,  and  sonorous,  but  not  so  much  so  as  the  preceding' 
The  metal  of  house-clock  bells  contains  a  little  more  tin  than  that  of  church-bells  and  the 
bell  of  a  repeater  contains  a  little  zinc  in  addition  to  the  other  ingredients  ' 

The  bronze-founder  should  study  to  obtain  a  rapid  fusion,  in  order  to  avoid  the  causes 
of  waste  indicated  above.  Reverberatory  furnaces  have  been  long  adopted  for  this  oDera- 
'  L" u^T"l^nT'  *5^  elliptical  are  the  best.  The  furnaces  with  spheroidal  domes 
are  used  by  the  bell-founders,  because  their  alloy  being  more  fusible,  a  more  moderate 
melUng  heat  is  required ;  however,  as  the  rapidity  of  the  process  is  always  a  matter  of 
consequence,  they  also  would  find  advantage  in  employing  the  elliptical  hearths  (see  th* 
form  of  the  melting  furnace,  as  figured  under  Smelting  of  copper  ores.)  Coal  is  now 
universally  preferred  for  fuel.  o    .,      ^x-  /  » «  uuw 

1  J^'^t^^.f  ^^  o^.coPPer  with  50  of  tin,  or  more  exacUy  of  32  of  the  former  with 
14t  of  the  latter,  constitutes  speculum  metal,  for  making  mirrors  of  reflecting  tele^cooes. 
This  compound  IS  near  y  white,  very  brittle,  and  susceptible  of  a  fine  polish  with  ^a  bril- 
liant surface.  The  following  compound  is  much  esteemed  in  France  for  makin<'  snecula. 
Melt  2  parts  of  pure  copper  and  1  of  grain-tin  in  separate  crucibles,  incorporate  thor- 
oughly with  a  wooden  spatula,  and  then  run  the  metal  into  moulds.  The  lower  surfac«» 
IS  the  one  that  should  be  worked  into  a  mirror.  sunace 

Mr.  Edwards,  in  the  Nautical  Almanack  for  1787,  gave  the  following  instructions  for 
making  speculum  metal. 

The  quality  of  the  copper  is  to  be  tried  by  making  a  series  of  alloys  with  tin  in  the  nro. 
portion  of  100  of  the  former  to  47,  to  48,  to  49,  and  to  50  of  the'latter  met'al ;  whe^n^ 
the  proportions  of  the  whitest  compound  may  be  ascertained.  Beyond  the  last  proportion 
the  alloy  begins  to  ose  in  brilliancy  of  fracture,  and  to  take  a  bluish  tint.  Haviticr  deter-' 
mined  this  point,  take  32  parts  of  the  copper,  melt,  and  add  one  part  of  brass  and  as  much 
silver,  covering  the  surface  of  the  mixture  with  a  little  black  flux;  when  the  whole  is 
melted,  stir  with  a  wooden  rod,  and  pour  in  from  *15  to  16  parts  of  melted  tin  Cas  indir. 
ted  by  the  preparatory  trials),  stir  the  mixture  again,  and  immediately  pour  it  out  into 
cold  water.  Then  melt  again  at  the  lowest  heat,  adding  for  every  16  parts  of  the  com- 
pound 1  part  of  white  arsenic,  wrapped  in  paper,  so  that  it  may  be  thrust  down  to  the 
bottom  of  the  crucible.  Stir  with  a  wooden  rod  as  long  as  arsenical  fumes  rise  and  then 
pour  It  into  a  sand  mould.  While  still  red  hot,  lay  themetal  in  a  pot-full  of  ve^r  hot  e " 
bers,  that  it  may  cool  very  slowly,  whereby  the  danger  of  its  cracking  or  flying  into 
splinters  is  prevented.  °        "J'"s  *"*" 

Having  described  the  different  alloys  of  copper  and  tin,  I  shall  now  treat  of  the  method 
of  separating  these  metals  from  each  other  as  they  exist  in  old  cannons,  damaged  bells, 
&c.  The  process  employed  on  a  very  great  scale  in  France,  during  the  Revolution,  fS 
obtaining  copper  from  bells,  was  contrived  by  Fourcroy ;  founded  upon  the  chemical  fad 
that  tin  IS  more  fusible  and  oxydizable  than  copper. 

1.  A  certain  quantity  of  bell  metal  was  completely  oxydized  by  calcination  '»  a  rrver 
beratory  furnace ;  the  oxyde  was  raked  out,  and  reduced  to  a  fine  powder. 

2.  Into  the  same  furnace  a  fresh  quantity  of  the  same  metal  was  introdueed  •  it  wa« 


I 


r  f; 


f .- 
1,1 


{C 


486 


COPPER. 


laelled,  and  there  was  added  to  it  one  half  of  its  weiarht  of  the  oxvde  formed  *«  the  first 
operation.  The  temperature  was  increased,  and  the  mixture  well  incorporated ;  at  the 
<»nd  of  a  few  hours,  there  was  obtained  on  the  one  hand  copper  almost  pure,  which  sub- 
sided in  a  liquid  state,  and  spread  itself  upon  the  sole  of  the  hearth,  while  a  compound 
of  oxyde  of  tin,  oxyde  of  copper,  with  some  of  the  earthy  matters  of  the  furnace,  collected 
on  the  surface  of  the  metallic  bath  in  a  pasty  form.  These  scoriae  were  removed  with  a 
rake,  and  as  soon  as  the  surface  of  the  melted  copper  was  laid  bare,  it  was  run  out.  The 
scoriae  were  levigated,  and  the  particles  of  metallic  copper  were  obtained  after  elutriation. 
By  this  process,  from  100  pounds  of  bell-metal,  about  50  pounds  of  copper  were  extracted, 
containing  only  one  per  cent,  of  foreign  matters. 

3.  The  washed  scoriae  were  mixed  with  |  their  weight  of  pulverized  charcoal;  the  mix- 
ture was  triturated  to  effect  a  more  intimate  distribution  of  the  charcoal ;  and  it  was  then 
put  into  a  reverberatory  hearth,  in  which,  by  aid  of  a  high  heat,  a  second  reduction  was 
effected,  yielding  a  fluid  alloy  consisting  of  about  60  parts  of  copper  and  20  of  tin;  while 
the  surface  of  the  bath  got  covered  with  new  scorise,  containing  a  larger  proportion  of 
tin  than  the  first. 

4.  The  alloy  of  60  of  copper  with  40  of  tin  was  next  calcined  in  the  same  reverbera- 
tory furnace,  but  with  stirring  of  the  mass.  The  air,  in  sweeping  across  the  surface  of  the 
bath,  oxydized  the  tin  more  rapidly  than  the  copper ;  whence  proceeded  crusts  of  oxyde 
that  were  skimmed  off  from  time  to  time.  This  process  was  continued  till  the  metallic 
alloy  was  brought  to  the  same  standard  as  bell-metal,  when  it  was  run  out  to  be  subjected 
to  the  same  operations  as  the  metal  of  No.  1. 

The  layers  of  oxyde  successively  removed  in  this  way  were  mixed  with  charcoal,  and 
reduced  in  a  foumeau  a  manchef  or  Scotch  lead  smelting  furnace. 

I  shall  not  prosecute  any  further  the  details  of  this  complicated  process  of  Fourcroy ; 
because  it  has  been  superseded  by  a  much  better  one  contrived  by  M.  Breant.  He  em- 
ployed a  much  larger  quantity  of  charcoal  to  reduce  the  scoriae  rich  in  tin;  and  increased 
the  fusibility  by  adding  crushed  oyster-shells,  bottle  glass,  or  even  vitrified  scoriae,  ac- 
cording to  the  nature  of  the  substance  to  be  reduced ;  and  he  treated  them  directly  in  a 
reverberatory  furnace. 

The  metal,  thus  procured,  was  very  rich  in  tin.  He  exposed  it  in  masses  on  a  sloping 
hearth  of  a  reverberatory  furnace,  where,  by  a  heat  regulated  according  to  the  proportions 
of  the  two  metals  in  the  alloy,  he  occasioned  an  eliquation  or  sweating  out  of  the  tin  Me- 
tallic drops  were  seen  to  transpire  round  the  alloyed  blocks  or  pigs,  and,  falling  like  rain, 
flowed  down  the  sloping  floor  of  the  furnace ;  on  whose  concave  bottom  the  metal  collect- 
ed, and  was  ladled  out  into  moulds.  When  the  alloy,  thus  treated,  contained  lead,  this 
inetal  was  found  in  the  first  portions  that  sweated  out.  The  purest  tin  next  came  forth, 
while  the  last  portions  held  more  or  less  copper  in  solution.  By  fractioning  the  products* 
therefore,  there  was  procured — 

1.  Tin  with  lead. 

2.  Tin  nearly  pure. 

3.  Tin  alloyed  with  a  little  copper. 

A  spongy  mass  remained,  exhibiting  sometimes  beautiful  crystallizations ;  this  mass, 
eommonly  too  rich  in  copper  to  afford  tin  by  liquation,  was  treated  by  oxydizeraent.  In 
this  manner,  M.  Breant  diminished  greatly  the  reductions  and  oxydations;  and  therefore 
incurred  in  a  far  less  degree  the  enormous  waste  of  tin,  which  flies  off  with  the  draught 
of  air  in  high  and  long-continued  heats.  He  also  consumed  less  fuel  as  well  as  labor, 
and  obtained  purer  products  of  known  composition,  ready  to  be  applied  directly  ia 
many  arts. 

He  treated  advantageously  in  this  manner  more  than  a  million  of  kilogrammes  (1000 
tuns)  of  scoriae,  for  every  2  cwts.  of  which  he  paid  40  centimes  (four-pence),  while  sev- 
eral million  kilogrammes  of  much  richer  scoriae  had  been  previously  sold  to  other  refiners 
at  5  centimes  or  one  sous. 

I  have  said  that  the  ancients  made  their  tools  and  military  weapons  of  .Bronze.  Scr- 
eral  of  these  have  been  analyzed,  and  the  results  are  interesting. 

An  antique  sword,  found  in  1799,  in  the  peat  moss  of  the  Somme,  consisted  of  copper 
87-47;  tin  12-53,  in  100  parts. 

The  bronze  springs  for  the  balistae,  according  to  PhUo  of  Byzantium,  were  made  of 
copper  97,  tin  3. 

Hard  and  brittle  nails  afforded  by  analysis,  92  of  copper,  and  8  of  tin. 

Of  three  antique  swords  found  in  the  env'rons  of  Abbeville,  one  was  found  to  consist 
of  85  of  copper  to  15  of  tin.  The  nails  of  the  handle  of  this  sword  were  flexible ;  they 
were  composed  of  copper  95,  tin  5. 

Another  of  the  swords  consisted  of  90  of  copper  and  10  of  tin ;  and  the  third,  of  96 
copper,  with  4  tin. 

A  fragment  of  an  ancient  scythe  afforded  to  analysis  92*6  copper,  and  7*4  tin. 

The  process  of  coating  copper  with  tin,  exemplifies  the  strong  aflinity  between  the 
two  metals.     The  copper  surface  to  be  tinned  is  first  cleared  up  with  a  smooth  sand- 


1^ 


(( 


COPPER. 


487 


stone;  then  it  is  heated  and  rubbed  over  with  a  little  sal  ammoniac,  till  it  be  perfectlj 
clean  and  bright :  the  tin,  along  with  some  pounded  rosin,  is  now  placed  on  the  fopper, 
which  is  made  so  hot  as  to  melt  the  tin,  and  allow  of  its  being  spread  over  the  surlace  with 
a  dossil  or  pad  of  low.  The  layer  thus  fixed  on  the  copper  is  exceedingly  thin  ;  Bayeo 
found  that  a  copper  pan,  9  inches  in  diameter  and  3J  inches  deep,  being  weighed  imme- 
diately before  and  after  tinning,  became  only  21  grains  heavier.  Now  as  the  area  tinned, 
including  the  bottom,  amounted  to  155  square  inches,  1  grain  of  tin  had  been  spread  over 
nearly  7^  square  inches ;  or  only  20  grains  over  every  square  foot. 

Copper  and  Jrsenic  form  a  white-colored  alloy,  sometimes  used  for  the  scales  of 
thermometers  and  barometers;  for  dials,  candlesticks,  &c.  To  form  this  compound,  suc- 
cessive layers  of  copper  clippings  and  white  arsenic  are  put  into  an  earthen  crucible; 
which  is  then  covered  with  sea  salt,  closed  with  a  lid,  and  gradually  healed  to  redness. 
If  2  parts  of  arsenic  have  been  used  with  5  of  copper,  the  resulting  compound  com 
monly  contains  one  tenth  of  its  weight  of  metallic  arsenic.  It  is  white,  slightly 
ductile,  denser,  and  more  fusible  than  copper,  and  without  action  on  oxygen  at  ordinary 
temperatures ;  but,  at  higher  heats,  it  is  decomposed  with  the  exhalation  of  arsenions 
acid.  The  white  copper  of  the  Chinese  consists  of  40*4  copper;  31*6  nickel;  25*4 
zinc;  and  26  iron.  This  alloy  is  nearly  silver  white;  it  is  very  sonorous,  well 
polished,  malleable  at  common  temperatures,  and  even  at  a  cherry  red,  but  very  brittle 
at  a  red-white  heat.  "When  heated  with  contact  of  air,  it  oxydizes,  burning  with  a 
white  flame.  Its  specific  gravity  was  8*432.  When  worked  with  great  care,  it  may 
be  reduced  to  thin  leaves,  and  to  wires  as  small  as  a  needle.  See  German  Silver, 
infra. 

Tutenag,  formerly  confounded  with  while  copper,  is  a  different  composition  from  the 
above.  Keir  says  it  is  composed  of  copper,  zinc,  and  iron ;  and  Dick  describes  it  as  a 
short  metal,  of  a  grayish  color,  and  scarcely  sonorous.  The  Chinese  export  it,  in  large 
quantities,  to  India. 

Copper,  White,  or  German  silver.  M.  Gersdorf,  of  Vienna,  states,  that  the  propor 
tions  of  the  metals  in  this  alloy  should  vary  according  to  the  uses  for  which  it  is  destined. 
When  intended  as  a  substitute  for  silver,  it  should  be  composed  of  25  parts  of  nickel,  25 
of  zinc,  and  50  of  copper.  An  alloy  better  adapted  for  rolling,  consists  of  25  of  nickel, 
20  of  zinc,  and  60  of  copper.  Castings,  such  as  candlesticks,  bolls,  &.C.,  may  be  made 
of  an  alloy,  consisting  of  20  of  nickel,  20  of  zinc,  and  60  of  copper;  to  which  3  of  lea^ 
are  added.  The  addition  of  2  or  2J  of  iron  (in  the  shape  of  tin  plate  ?)  renders  the  pack 
fong  much  whiter,  but,  at  the  same  time,  harder  and  more  brittle. 

Keferstein  has  given  the  following  analysis  of  the  genuine  German  silver,  as  madefros 
the  original  ore  found  in  Hildburghausen,  near  Suhl,  in  Henneberg : — 

Copper        -        -  -         40*4 

Nickel 31-6 

Zinc  ....        25*4 

Iron        .....      2*6 


100*0 


!1 


Chinese  packfong,  according  to  the  same  authority,  consists  of  5  parts  of  copper,  aDoj 
ed  with  7  parts  of  nickel,  and  7  parts  of  zinc. 

The  best  alloy  for  making  plummer  blocks,  bushes,  and  steps  for  the  steel  or  iron  gtxd 
geons  and  pivots  of  machinery  to  run  in,  is  said  to  consist  of  90  parts  of  copper,  5  ol 
zinc,  and  5  of  antimony. 

A  factitious  protoxyde  of  copper,  of  a  fine  red  color,  may  be  made  by  melting  together 
with  a  gentle  heat,  100  parts  of  sulphate  of  copper,  and  59  of  carbonate  of  soda  in  crys 
tals,  and  continuing  the  heat  till  the  mass  become  solid.    This  being  pulverized  antf 
mixed  exactly  with  15  parts  of  copper  filings,  the  mixture  is  to  be  heated  to  whiteness,  in 
a  crucible,  during  the  space  of  20  minutes.    The  mass,  when  cold,  is  to  be  reduced  \i 
powder,  and  washed.     A  beautiful  metallic  pigment  may  be  thus  prepared,  at  the  cost 
of  2s.  a  pouud. 

All  the  oxydes  and  salts  of  copper  are  poisonous ;  they  are  best  counteracted  by  ad 
ministering  a  large  quantity  of  sugar,  and  sulphureted  hydrogen  water. 

The  following  scientific  summary  of  copper  ores  in  alphabetical  order  may  prove  ac- 
ceptable to  many  readers,  amid  the  present  perplexing  distribution  of  the  native  metallic 
compounds  in  mineralogical  systems. 

1.     Jtrseniate  of  Copper. 

A.  Erinite,  rhomboidal  arseniate  of  copper,  micaceous  copper,  kup/er glimmer. 
Emerald  green:  specific  gravity  4*043;  scratches  calc-spar;  yields  water  by  heat: 
fusible  at  the  blowpipe,  and  reducible  into  a  white  metallic  globule.  Soluble  in  nitric 
acid;  the  solution  throws  down  copper  by  iron.  It  consists  of  arsenic  acid  33*78; 
oxyde  of  copper  59-24;  water  5;  alumina  1*77.  It  is  found  in  Cornwall,  Ireland, 
Hungary. 

B.  Liroconite ;  octahedral  arseniate  of  copper ;  lens  ore,  so  called  fn»n  the  flatnesi 


I; 


Ill 

«■ 

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488 


COPPER. 


COPPER. 


48$ 


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I 


rf  ihe  cr^'stal.  BIjc;  specific  gravity  2-88;  scratches  calc-spar.  It  consists  of  aretnie 
ftcid  14;  oxyde  of  copper  49;  water  35.  It  is  found  in  Huel-Mutrel,  Huel-Gorland, 
Iliiel-Unitv,  mines  in  Cornwall. 

C.  OHvenile ;  right  prismatic  arseniate  of  copper ;  olive-ore.  Dull  green ;  specific 
gravity  4-28  ;  scratches  fluor ;  yields  no  water  by  heat ;  fusible  at  the  blowpipe  into  a 
glassy  bead,  enclosinsr  a  white  metallic  grain.  It  consists  of  arsenic  acid  45,  oxyde  of 
copper  50-62.  It  affords  indications  of  phosphoric  acid,  which  the  analysts  seem  to  have 
overlooked     It  occurs  in  the  above  and  many  other  mines  in  Cornwall. 

D.  Jphane.se.  Trihedral  arseniate  of  copper.  Bluish  green,  becoming  gray  upon  the 
surface ;  specific  gravity  4*28 ;  scarcely  scratches  calc-spar ;  yields  water  with  heat ;  ani? 
traces  of  phosphoric  acid. 

The  fibrous  varieties  called  wood  copper,  contain  water,  and  resemble  the  last  species 
in  composition. 

2.  Carbonate  of  Copper. 

A.  ^2ttn7g;  kupferlazur.  Blue.  Crystallizes  in  oblique  rhomboidal  prisms ;  specilie 
gravity  3  to  3-83 ;  scratches  calc-spar,  is  scratched  by  fluor;  yields  water  with  heat, 
and  blackens.  Its  constituents  are,  carbonic  acid  25-5 ;  oxyde  of  copper  69*1 ;  water 
5-4.  The  Chessy  and  Banat  azurite  is  most  profitably  employed  to  make  sulphate  of 
copper. 

B.  Malachite ;  green  carbonate  or  mountain  green.  Crystallizes  in  right  rhomboidal 
prisms  ;  specific  gravity  3*5 ;  aflbrds  water  with  heat,  and  blackens.  It  consists  of  car- 
bonic acid  18-5;  oxyde  of  copper  72  2;  water  9*3. 

C.  Mysorine ;  anhydrous  carbonate  of  copper.  Dark  brown  generally  stained  green 
or  red ;  conchoidal  fracture ;  soft,  sectile ;  specific  gravity  2'62.  It  consists  of  carbonic 
acid  16-7;  oxyde  of  copper  60-75 ;  peroxyde  of  iron  19-5;  silica  2'10.  This  is  a  rare 
mineral  found  in  the  Mysore. 

3.  Chromate  of  Copper  and  Lead ;  vauquelinite.  Green  of  various  shades ;  specific 
gravity  6-8  to  7-2;  brittle;  scratched  by  fluor;  fusible  at  the  blowpipe  with  froth  and 
the  production  of  a  leaden  bead.  It  consists  of  chromic  acid  28-33  ;  oxyde  of  lead  60*87; 
oxyde  of  copper  10*8.    It  occurs  at  Berezof  in  Siberia  along  with  chromate  of  lead. 

4.  Dioptase;  silicate  of  copper;  emerald  copper.  Specific  gravity  3-3 ;  scratches 
glass  with  difficulty  ;  affords  water  with  heat,  and  blackens  ;  infusible  at  the  blowpipe. 
it  consists  of  silica  43-18;  oxyde  of  copper  45-46;  water  11-36.  This  rare  substance 
comes  from  the  government  of  Kir^is. 

The  silicate  of  Dillenberg  is  similar  in  composition. 

5.  Gray  copper  ore  called  Panabase,  from  the  number  of  metallic  bases  which  it 
contains;  and  Fahlerz.  Steel  gray  ;  specific  gravity  4-79  to  5-10;  crystallizes  in  regular 
tetrahedrons;  fusible  at  the  blowpipe,  with  disengagement  of  fumes  of  antimony  and 
occasionally  of  arsenic ;  swells  up  and  scorifies,  affording  copper  with  soda  flux.  Is  acted 
upon  by  nitric  acid  with  precipitation  of  antimony  ;  becomes  blue  with  ammonia  ;  yields 
a  blue  precipitate  with  ferrocyanide  of  potassum ;  as  also  indications  frequently  of  zinc, 
mercnrv,  silver,  &c.  Its  composition  which  is  very  complex  is  as  follows :  sulphur  26-83 ; 
antimony  12-46;  arsenic  10*19;  copper  4060;  iron  4-66;  zinc  3-69;  silver  0-60 
Some  specimens  contain  from  5  to  31  per  cent,  of  silver.  The  gray  copper  ores  are  very 
common;  in  Saxony;  theHartz;  :!r)rnwall;  at  Dillenberg ;  in  Mexico  <  Peru,  &c.  They 
are  important  on  accounLboth  of  their  copper  and  silver.  TennantHe  is  a  variety  o( 
Fahlerz.  It  occurs  in  Cornwall.  Its  constituents  are,  sulphur  28-74 ;  arsenic  11-84  j 
copper  45-32 ;  iron  9-26. 

6.  Hydrated  silicate  of  Copper ;  or  Chrysocolla.  Green  or  bluish  green  ;  specific 
gravity  203  to  2-16;  scratched  by  steel ;  very  brittle;  affords  water  with  heat,  and 
blackens;  is  acted  upon  by  acids,  and  leaves  a  silicious  residuum.  Solution  becomes 
blue  with  ammonia.  Its  constituents  are  silica  26 ;  oxyde  of  copper  50 ;  water  17 ; 
carbonic  acid  7. 

7.  Muriate  of  Copper.  Gtakamite;  green;  crystallizes  in  prisms;  specific  gravity 
4*43.  Its  constituents  arc,  chlorine  15-90;  copper  14-22;  oxyde  of  copper  54-22;  water 
14'16;  oxyde  of  iron  1*50.  The  green  sand  of  Peru,  collected  by  the  inhabitants  of 
Atakama,  is  this  substance  in  a  decomposed  state. 

8.  Oxyde  of  Copper. 

A.  Black,  or  Melaconise ;  a  black  earthy  looking  substance  found  at  Chessy  and 
other  places.     It  is  dentoxydc  of  copper. 

B.  Protoxyde  or  red  oxyde  of  copper ;  ziegelerr.  Crystallizes  in  the  regular  octahe 
dron;  specific  gravity  5-69 ;  scratches  calc-spar;  fusible  at  the  blowpipe  into  the  black 
oxyde ;  and  reducible  in  the  smoke  of  the  flame  to  copper ;  acted  upon  by  nitric  acid 
with  disengagement  of  nitrous  gas;  solution  is  rendered  blue  by  ammonia.  Its  constitu- 
ents are  oxygen  11*22 ;  copper  88*78.  It  occurs  near  Chessy,  and  upon  the  eastern  slope 
of  the  Altai  mountains. 

9.  Phosphate  of  Copper.  Dark  green ;  crystallizes  in  octahedrons ;  specific  gravity 
3*6  to  3-8;    scratches  calc-spar ;   yields  water  with  heat;    and  affords  metallic  coppci 


i 


i 


with  soda  flux  j  acted  on  by  nitric  acid.    Its  constituents  are,  phosphoric  acid  28*7 ; 
oxyde  of  copper  639;  water  7*4.    It  occurs  at  the  mines  of  Libethen  in  Hungary. 

10.  Pyri'ous  Copper ;  Kupferkies;  a  metallic  looking  substance,  of  a  bronze-yellow 
color,  crystallizing  in  octahedrons  which  pass  into  tetrahedrons;  specific  gravity  4-16; 
fusible  at  the  blowpipe  into  beads  attractable  by  the  magnet,  and  which  afterwards 
afford  copper  with  a  soda  flux;  soluble  in  nitric  acid;  solution  is  rendered  blue  by  am- 
monia, and  affords  an  abundant  precipitate  of  iron.  Its  composition  is,  sulphur  36; 
copper  34-5;  iron  30-5;  being  a  combined  sulphuret  of  these  two  metals.  This  is  the 
most  important  metallurgic  species  of  copper  ores.  It  occurs  chiefly  in  primitive  forma- 
tions, as  among  gneiss  and  mica  slate,  in  veins,  or  more  frequently  masses,  in  very 
many  parts  of  the  world — Cornwall,  Anglesea,  Wicklow,  &c.  It  is  found  among  the 
early  secondary  rocks,  in  Shetland,  Yorkshire,  Mannsfeldt,  &c.  The  finest  crystallized 
specimens  come  from  Cornwall,  Derbyshire,  Freyberg,  and  Saint  Marie-aux-Mines  in 
France. 

11.  Sekniale  of  Copper ;  Berzeline.  Is  of  metallic  aspect ;  silver  white;  ductile;  fusi- 
ble at  the  blowpipe  into  a  gray  bead,  somewhat  malleable;  is  acted  upon  by  nitric  acid; 
consists  of  selenium  40  ;  copper  64, 

12.  Sulphate  of  Copper ;  Cyanose.  Blue;  soluble,  &c.  like  the  artificial  sulphates^ 
which  see. 

Brochantite  is  a  subsulphate  of  copper,  observed  in  small  crystals  at  Ekaterinenbourg 
in  Siberia. 

13.  Sulphuret  of  Copper;  Kupferglanz.  Of  a  steel  gray  metallic  aspect;  crystallizes 
in  rhomboids ;  specific  gravity  5*69 ;  somewhat  sectile,  yet  brittle ;  fusible  with  intu- 
mescence at  the  blowpipe,  and  yields  a  copper  bead  with  soda ;  soluble  in  nitric  acid ; 
becomes  blue  with  ammonia,  but  lets  fall  scarcely  any  oxyde  of  iron.  Its  constituents 
are  sulphur  19;  copper  79'5;  iron  0*75;  silica  1*00.  It  occurs  in  small  quantities  in 
Cornwall,  &c. 

The  chemical  preparations  of  copper  which  constitute  distinct  manufactures  are,  Blue 
or  Roman  vitriol ;  for  which  see  Sulphate  of  Copper ;  Scheele's  green  and  Schweinurtb 
green,  Verdiler,  and  Verdigris.    See  these  articles  in  their  alphabetical  places. 

The  copper  mines,  now  so  important,  were  so  little  worked  until  a  recent  period,  that 
in  1799  we  are  told  in  a  Report  on  the  Cornish  mines,  "it  was  not  until  the  begin- 
ning of  the  last  century  that  copper  was  discovered  in  Britain."  This  is  not  correct  for 
in  1250.  a  copper  mine  was  worked  near  Keswick  in  Cumberland.  Edward  HI. 
granted  an  indenture  to  John  Ballanter  and  Walter  Bolbolter,  for  working  all  "mines 
of  gold,  silver,  and  copper;"  but  that  the  quantity  found  was  very  small  is  proved  from 
the  fact  that  Acts  of  Parliament  were  passed  in  the  reigns  of  Henry  VIII.  and  Edward 
VI.  to  prevent  the  exportation  of  brass  and  copper,  "lest  there  should  not  be  metal 
enough  left  in  the  kingdom,  fit  for  making  guns  and  other  engines  of  war,  and  for 
household  utensils;"  and  in  1665  the  calamine  works  were  encouraged  by  the  govern- 
ment^ as  "  the  continuing  these  works  in  England  will  occasion  plenty  of  rough  copper 
to  be  brought  in." 

At  the  end  of  the  seventeenth  century  some  "gentlemen  from  Bristol  made  it  their 
business  to  inspect  the  Cornish  mines,  and  bought  the  copper  for  2/.  lOs.  per  ton,  and 
scarce  ever  more  than  41.  a  ton." 

In  1700,  one  Mr.  John  Costor  introduced  an  hydraulic  engine  into  Cornwall,  by 
which  he  succeeded  in  draining  the  mines,  and  "he  taught  the  people  of  Cornwall  also 
a  better  way  of  assaying  and  dressing  the  ore." 

The  value  and  importance  of  copper  mines  since  that  period  has  been  regularly 
increasing.     During  a  terra  of  about  30  years  220  mines  have  sold  their  ores  at  ths 

Sublic  sales.     The  following  table  (p.  490)  from  a  report  by  Sir  Charles  Lemon,  Bart 
L  P.,  represents  the  progress  of  copper  mining,  from  1771  to  1837. 

« 

The  produce  of  the  copper  mines  of  Cornwall  since  1845,  has  been  as  follows. 


Years. 

Ore  in  Tons. 

Copper  in  Tons. 

Money  Value. 

1845 
1846 
1847 
1848 
1849 
1850 

162,557 
150,431 
155,985 
147,701 
146,326 
155,025 

12,883 
11,851 
12,754 
12,422 
11,683 
12,254 

£.            t. 

919,934     6 
796.182     6 
889,287     0 
720,090     0 
763,614     0 
840,410     0 

i 


490 


COPPER. 


Yeara. 


1771 

1780 

1799 

1800 

1802 

1805 

1808 

1809 

1812 

1814 

1816 

1818 

1821 

1825 

1827 

1831 

1837 


Tons  of  Ore. 


Tona  of  Copper. 


Total  Value  of 
Ore. 


27,896 

24,433 

61,273 

66,981 

63,937 

78,452 

67,867 

76,245 

71,647 

74,322 

77,334 

86,174 

98,426 

107,454 

126,700 

146,502 

140,753 


8,347 
2,932 
4,223 
6,187 
6,228 
6,234 
6,796 
6,821 
6,720 
6,369 
6,697 
6,849 
8,514 
8.226 
10,311 
12,218 
10,823 


189,609 

171,231 

469,664 

660,926 

445,094 

864,410 

495,303 

770,028 

649,665 

627,501 

447,959 

686,006 

60.5,968 

726,353 

745,178 

817,740 

908,613 


Standard  Value 
per  Ton. 


81 
83 
121 
133 
111 
170 
100 
143 
111 
130 
98 
166 
103 
124 
106 
100 
119 


With  the  improvements  m  the  construction  of  the  steam-engine,  the  facilities  for 
working  the  mines  have  been  increased,  The  first  steam  engine  employed  in  the 
county  was  set  to  work  at  Huel  Vor  tin  mines,  near  Helstone,  in  1713,  by  Newcomen- 
but  it  was  not  until  the  reconstruction  of  the  engine  was  effected  by  Watt  that  steam 
power  was  generally  employed  for  draining  the  mines.  The  rapid  advance  made  br 
Cornish  engineers  in  the  perfection  of  their  engines  will  be  seen  by  the  following  return 
of  the  duty,  that  is,  the  performance  of  each,  which  is  reckoned  by  the  number  of 
nuilions  of  pounds  lifted  a  foot  high  by  the  consumption  of  a  bushel  of  coals  •— 


Name  of  Mine. 


Highest  Duty. 


Stray  Park,  1813 
Dolcoath,  1816 
Consolidated  Mines,  1822 
Consolidated  Mines,  1827 
Fowey  Consols,  1834 
United  Mines,  1842 


Copper  exported  :— 


29,000,000 
40,000,000 
44,000,000 
67,000,000 
97,000,000 
108,000,000 


Years  ending 


5th  January,  1825  - 

1826  - 

1827  - 

1828  - 

1829  - 
J830  - 

1831  - 

1832  - 

1833  - 

1834  - 

1835  - 

1836  - 

1837  - 


Wrought. 


To  all  parts. 


Tons. 


6327 
6172 
5171 
5855 
5417 
4787 
5948 
6105 


Unwroufht. 


To  India. 


Tons. 


1801 
2317 
2423 
2312 
1769 
2104 
1993 
1588 


To  all  paru. 


Totu. 
960 


Total. 


To  ail  part*. 


I 


Tmu. 


I 


130 

1329 

1079 

2682 

8,009 

3150 

9,322 

3714 

8,885 

4569 

10,424 

4019 

9,436 

5283 

10,072 

5935 

11,883 

3909 

10,014» 

*  Supplement  to  the  Mining  Jouma<,  Feb.  98,  1838. 


COPPER. 


491 


i 


Statistics  of  Copper  for  Cornwall  in  1837-— The  total  quantity  of  ore  sold  was  142,089 
tons  (of  21  cwts.)  yielding  an  average  produce  of  eight  per  cent;  the  quantity  of  fine 
copper  being  11,209  tons  1  cwt;  and  the  average  price  of  the  ore  5/.  153.  6<i;  the 
total  amount  of  the  sales  for  the  twelve  months  being  822,516/.  The  standard  upon 
the  6th  of  January  was  127/.  16«. ;  this  was  the  highest  for  the  year.  Upon  the  22a  of 
June  it  was  at  the  lowest,  being  only  93/.  18«.  It  went  up  again  to  120/.  10*.  upon  the 
Bth  of  October;  but  declined  with  some  slight  fluctuation  to  107/.  18jf.  upon  the  28th 
of  December.  The  largest  quantity  sold  at  any  one  ticketing  was  4670  tons,  upon  the 
4th  of  May ;  and  the  smallest  1088,  upon  the  17th  of  August  The  highest  produce 
was  nine  and  five  eighths  per  cent  upon  the  13th  of  July;  and  the  lowest,  seven,  upon 
the  26th  of  January.  The  greatest  weekly  total  was  25,887/.,  upon  the  2d  of  Novem- 
ber, and  the  least  5694/.  upon  the  I7th  of  August  The  average  sum  per  week  was 
16,817/.* 


Quantity  of  Copper  produced  in  the  several  districts  of  Great  Britain  and  Ireland : — 


With  Ores  from— 

1828. 

1829. 

1830. 

1831. 

1832. 

Cornwall              .           -           .          - 
Devonshire          .... 
Other  parts  of  England - 
Island  of  Anglesea          .           .           - 
Other  parts  of  VValea      ... 
Ireland      -           .           -           -           . 
Isle  of  Man          .... 

Total  copper  from  the  ores  of 
the  United  Kingdom  - 
Copper  smelted  from  Foreign  ores    - 

General  total    .           .           - 

Tons. 

1966 
404 
71 
738 
259 
706 

Tons. 

9763 

318 

36 

901 

172 

790 

4 

Tons. 

10,890 

368 

10 

815 

237 

768 

9 

Tons. 

12,218 

313 

31 

809 

123 

972 

15 

Tons. 

12,099 

249 

42 

852 

237 

974 

12 

12,169 

11,994 
30 

13,097 
124 

14,480 
100 

14,4&5 
56 

12,169 

12,024 

13,221 

14,580 

14,541 

Table  of  the  produce  of  Copper  Ores  and  fine  Metal  in  Cornwall,  from  1800  to  1830. 


Year*. 

Ores. 

Metal. 

Value  of  Ore. 

Metal. 

Average  Standard. 

Tons  of  21  Cwts. 

Tons.     Cwt. 

Per  Cent,  of  Ore. 

Price  per  ' 

Ton. 

£           a. 

d. 

£        a. 

d. 

1800 

55,981 

5187    0 

550,925    0 

0 

9i 

133      3 

6 

1801 

56,611 

5268    0 

476,331     0 

0 

9i 

117    8 

0 

1802 

53,937 

5228  15 

445,094    0 

0 

9| 

no  18 

0 

1804 

64,637 

5374  18 

507,840  11 

0 

8| 

136    5 

0 

1806 

79,269 

6863  10 

730,845    6 

0 

8| 

138    5 

0 

1308 

67,867 

6795  13 

495,303  10 

0 

10 

100    7 

0 

1810 

66,048 

5682  19 

570,035    8 

0 

8J 

132    5 

0 

1812 

71,547 

6720    7 

549,665     6 

0 

n 

111     0 

0 

1814 

74,322 

6369  13 

627,501   10 

0 

8* 

130  12 

0 

1816 

77,334 

6697    4 

447,959  17 

0 

8| 

98  13 

0 

1818 

86,174 

6849    7 

686,005    4 

0 

71 

134  15 

0 

1820 

91,473 

7508    0 

602,441  12 

0 

8| 

113  15 

0 

1822 

104,523 

9140    8 

663,085  13 

0 

8| 

104    0 

0 

1824 

99,700 

7823  15 

587,178    0 

0 

7| 

110    0 

0 

1826 

117,308 

9026  12 

788,971  15 

0 

7f 

123    3 

0 

1828 

130,366 

9921     1 

756,174  16 

0 

7| 

112    7 

0 

1829 

124,502 

9656  10 

717,334    0 

0 

7f 

109  14 

0 

1830 

143,296 

11,224  19 

887,900    0 

0 

n 

114    4 

0 

1834 
1835 

1 150,617 

12,271  14 

893,402  15 

0 

^ 

106  11 

°  1 

;f 


The  following  table,  extracted  from  the  London  Mining  Journal,  July  18,  1852 
gives  the  comparative  averages  of  the  weekly  sales  of  Copper  Ores  for  ten  yeara^  to  th« 
second  week  in  July,  1852,  at  the  Royal  Hotel,  Truro,  Cornwall. 

*  Mining  Review,  Feb.  28, 1838. 


t 


492 


COPPER. 


1 

Year. 

Tons. 

Produce. 

Amount. 

Stamlard. 

Price  of 
Copper  Ore. 

Price  of 
Copper  Cake. 

X     #.  <t 

£.    $. 

X    «. 

X    1.    d. 

1842 

2196 

6| 

9,676    8    6 

108    7 

67  13 

92    0     0 

1843 

2986 

8* 

16,788  13    6 

105    5 

70  14 

82    0    0 

1844 

2021 

6| 

13.012  11    6 

107    3 

66    6 

83    0     0 

1845 

3205 

7 

18,254    5    6 

107  18 

72  15 

88     0     OA 

1846 

2289 

8 

12,156    6    6 

98  13 

65    0 

93    9    6 

1847 

2386 

8 

h 

14.184  19    0 

IW  10 

72    2 

98  10    1 

1848 

2372 

9 

11,039  11    0 

80    2 

M  19 

88    0    0 

18 19 

2538 

8 

13.913    5    6 

94    9 

62  18 

79    0    0 

ia50 

2490 

9 

15,3a5    2    6 

97  14 

67  13 

84    0    0 

1       1851 

2541 

14,015  14    6 

99  14 

66  10 

84    0    84 

An  account  of  the  quantities  of  Foreign  wrought  and  unwrought  Copper,  and  Copper 
Ore,  imported  and  exported,  and  of  British  wrought  and  unwrought  Copper  exported 
from  the  United  Kingdom ;  together  with  the  quantities  and  value  of  Copper  Ore 
smelted  in  Cornwall  and  Swansea,  and  the  quantity  of  Copper  produced  in  those  places; 
and  in  the  county  of  Devon ;  together  with  the  market  prices  of  sheet  and  cake  Cop 
per.  in  the  year  ending  5th  January,  1836: — 


Foreign  Copper  imported : 

Unwrought  in  bricks  or  pigs,  rose  and  cast  copper,  Cwts. 
Part  wrought,  viz.,  bars,  rods,  or  ingots,  hammered 
or  raised  -------- 

"Wrought  plates  and  coin      ----- 

—      old  for  re-manufacture  -        -        -        - 

Copper  ore  Foreign      ------ 

Manufactures  of  copper,  entered  by  weight  - 

—  entered  at  value     - 
Foreign  copper  exported,  viz : — 

Unwrought,  in  bricks  and  pigs,  rose  and  cast  cop- 
per ---------  Cwts. 

Part  wrought,  viz.,  bars,  rods,  or  ingots,  hammered 
or  raised  -------- 

Old,  fit  only  for  re-manufacture    -        -        -        - 

Smelted  in  the  United  Kingdom  from  foreign  ore    - 
Manufactures  of  copper,  entered  by  weight  - 

—  entered  at  value 

BRITISH  COPPER. 

Exported,  unwrought,  in  bricks  and  pigs  -        -        -  Cwts, 
—       wrought  sheets,  nails,  &c.         -        -        - 

—  wire  ------ 

—  of  other  sorts      -        -        -        - 
Total  of  British  copper  exported  -        .        -        - 

Ores  sold  in  Cornwall : — 

Quantity  of  ore  -------  Ton* 

Value  of  ditto      ------- 

Quantity  of  metal        ------  Tons 

Standard      _----.-- 

Produce  per  cent.         --.--- 

Ores  sold,  &c.  in  Swansea : — 
Quantity  of  ore  -------  Tons 

Value  of  ditto     ------- 

Quantity  of  metal        ------  Tons 

Standard     -------- 

Produce  per  cent.        ------ 

Copper  sold  in  Devonshire   <  ^^^1  S     "        '        '  ■'^*^* 

Total  quantity  of  copper  raised  in  the  United  Kingdom,  ^ 

exclusive  of  Anglesea  and  Staffordshire,  and  deducting  I 

1083  tons  of  metal,  value  88,207/.,  the  produce  of  4985  ( 

tons  of  foreign  ore  sold  at  Swansea,  included  above,      J 


Qaantity. 


6,389 

1,968 

2 
493 

278,900 
650 


6,898 

2,013 

265 

65,456 

650 


63,252 

103,433 

66 

15,197 
182,225 


14,474 


Value. 


£      s,    d. 


5,363    0    0 


112    0    0 


893,403  0  0 

106  11  0 

223,958  0  0 

101  18  0 


1 


COPPER. 


493 


Quantity  of  coppei  ore  raised  in  Cornwall  in  the  year  1846,  150,431  tons;  value  o^ 
796,182/.  6«.  6d. 

Quantity  raised  in  the  year  1847,  165,985  tons;  value  of,  889,287/.  0*.  6<£ 

Quantity  of  metallic  copper  produced  in  the  former  year,  11,850  tons;  in  the  latter, 
12,754. 

Produce  per  cent  7^  and  8|  respectively.     See  Metaluc  Statistics. 


Pescriptioa. 

Imports. 

Entries  for 
Consumption. 

Exports, 
Foreign. 

Exports, 
British. 

Duty  oa 
IniI>orts. 

1850. 

1851. 

1850. 

1851. 

1850. 

1851. 

1850. 

1851. 

1850. 

1851. 

Copper  ore  and  regulus, 
tons. 

unwrought  and  part 
wrought,  cwts. 

bricks  and  pige,  cwts.    - 

sheets,  nails,  &.C.  (in- 
cluding mixed  or  yel- 
low metal  for  sheath- 
ing), cwts. 

wrought  of  other  sorts, 
cwts,    -          -           . 

45,862 
97,621 

•              * 

42,476 
106,064 

*       • 

45,705 
83,626 

42,219 

103,500 

*        . 

16,685 

25,746 

-       • 

154,678 

263,008 
8,468 

l'u,939 

216,075 
19,939 

2,285 
523 

211 
647 

Coppering  Iron  and  Zixa  The  great  advantages  which  would  arise  from  per- 
fecting a  plan  whereby  the  easily  oxidizable  metals,  such  as  iron  and  zinc,  could  be 
coated  with  copper  at  a  cheap  rate,  induced  Messrs.  Eisner  <fe  Philip,  of  Berlin,  to 
undertake  a  series  of  experiments,  to  ascertain  if  such  could  not  be  effected  more  eco- 
nomically than  by  employing  the  eyanuret  of  potassium,  and  in  this  they  have  been  suc- 
cessful. For  coating  iron  the  article  must  be  well  cleaned  in  rain  or  soft  water,  and 
rubbed  before  immersing  it  in  the  solution,  which  may  be  either  chloride  of  potassium, 
chloride  of  sodium,  with  a  little  caustic  ammonia  added,  or  tartrate  of  potash,  with  a 
email  portion  of  carbonate  of  potash.  At  the  extremity  of  the  wire,  in  connection  with 
the  copper,  or  negative  pole  of  the  battery,  is  fixed  a  thin  flattened  copper  plate,  and 
the  article  to  be  coated  is  attached  to  the  wire  from  the  zinc,  or  positive  pole,  and  both 
are  then  immersed  in  the  exciting  solution,  the  copper  plate  only  partially.  The  liquid 
should  be  kept  at  a  temperature  of  from  16°  to  20°  Centigrade,  and  the  success  of  the 
operation  depends  greatly  on  the  strength  and  uniformity  of  the  galvanic  current  "When 
the  chlorides  are  employed,  the  coating  is  of  a  dark,  natural  copper  color;  and  with  tar- 
trate of  potash,  it  assumes  a  red  tinge,  similar  to  the  red  oxide  of  copper.  When  suffi- 
ciently covered,  the  article  is  rubbed  in  sawdust,  and  exposed  to  a  current  of  warm  air 
to  dry,  when  they  will  take  a  fine  polish,  and  resist  all  atmospheric  influence.  In 
coating  zinc  with  copper,  the  same  general  principles  will  apply  as  for  iron,  only  ob- 
serving that,  in  proportion  to  the  size  of  the  article,  the  galvanic  current  must  be  less 
powerful  for  zinc.  The  surfaces  must  be  perfectly  smooth,  and  fcr  this  reason  it  is  well 
to  rub  them  thoroughly  with  fine  sand,  and  polish  with  a  brush.  Tartrate  of  potash  is 
the  best  existing  liquid  for  coating  zinc.  By  very  simple  means  large  articles  in  iron 
and  zinc  may  be  coated  with  copper  by  the  above  cheap  chemical  solutions,  which 
could  not,  at  any  former  period,  be  effected  from  the  high  price  of  eyanuret  of  potas- 
sium. 

Copper  Medals  and  Medallions  may  be  readily  made  in  the  following  way: — 
Let  black  oxide  of  copper,  in  fine  powder,  be  reduced  to  the  metallic  state,  by  ex- 
posing it  to  a  stream  of  hydrogen,  in  a  gun-barrel,  heated  barely  to  redness.  The 
metallic  powder  thus  obtained  is  to  be  sifted,  through  crape,  upon  the  surface  of 
the  mould,  to  the  thickness  of  ^  or  |  of  an  inch,  and  is  then  to  be  strongly  pressed  upon 
it,  first  by  the  hand,  and  lastly  by  percussion  with  a  hammer.  The  inipression  thus 
formed  is  beautiful;  but  it  acquires  much  more  solidity  by  exposure  to  a  red  heat,  out 
of  contact  with  air.  Such  medals  are  said  to  have  more  tenacity  than  melted  copper, 
and  to  be  sharply  defined. 

M.  Boettger  proposes  the  following  improvement  upon  the  above  plan  of  Mr.  Osann : — 
He  prepared  the  powder  of  copper  easier  and  of  better  quality,  by  precipitating  a 
boiling  hot  solution  of  sulphate  of  copper,  with  pieces  of  zinc,  boiling  the  metallic 
powder  thus  obtained  with  dilute  sulphuric  acid  for  a  little,  to  remove  all  traces  of  the 
zinc  or  oxide,  washing  it  next  with  water,  and  drying  it  in  a  tubulated  retort  by  the 
heat  of  a  water  bath,  while  a  stream  of  hydrogen  is  passed  over  it  This  cuprous 
precipitate  possesses  so  energetic  an  affinity  for  oxygen,  that  it  is  difficult  to  prevent  its 
passing  into  the  state  of  orange  oxide.  If  it  be  mixed  with  one  half  its  atomic  weight 
of  precipitated  sulphur,  and  the  two  be  ground  together,  they  combine  very  soon  into 
sulphuret  of  copper  with  the  evolution  of  light 


h 


w 

I 


494 


COPROLITES. 


Copper,  Purifying.— Copper  may  be  purified  by  melting  100  parts  of  it  with  10 
parts  of  copper  scales  (black  oxideX  along  with  10  parts  of  ground  bottle-glass  or  other 
flux.  Mr.  Lewis  Thompson,  who  received  a  gold  medal  from  the  Society  of  Arts  for 
this  invention,  says,  that  after  the  copper  has  been  kept  in  fusion  for  half  an  hour,  it  will 
be  found  at  the  bottom  of  the  crucible  perfectly  pure ;  while  the  iron,  lead,  arsenic,  Ac., 
with  which  this  metal  is  usually  contaminated,  will  be  oxidized  by  the  scales,  and  will 
dissolve  in  the  flux,  or  be  volatilized.  Thus  he  has  obtained  perfectly  pure  copper 
from  brass,  bell-metal,  gun-metal,  and  several  other  alloys,  containing  from  4  up  to  50 
per  cent  of  iron,  lead,  antimony,  bismuth,  arsenic,  dec  The  scales  of  copper  are  cheap, 
being  the  product  of  every  large  manufactory  where  that  metal  is  worked. 
COPPERAS.  (Couperose  verte,  Fr. :  Eisenvitriol,  Germ.)  Sulphate  of  iron. 
COPROLITES,  OR  FOSSIL  MANURE.  Wherever  there  is  an  out-cropping  of  the 
upper  green  sand  (the  stratum  in  which  coprolites  are  found) — and  it  extends  a  con- 
siderable distance  around  Cambridge — there  these  peculiar  nodules  may  be  met  with. 
And  this,  the  surface  bottom  of  an  ancient  deep  sea,  appears  to  have  been  the  receptacle 
of  the  bones  and  fiecal  matter  of  its  inhabitants  for  a  long  period,  which  matter  is  now, 
by  the  united  penetrating  researches  of  the  chemist  and  geologist,  brought  to  light,  as 
containing  the  fertilizing  principle  and  pabulum  of  vegetable  life,  verifying  the  axiom 
of  chemistry,  that  nothing  is  lost  in  organic  atoms,  and  that  the  refuse  of  former  ages, 
in  an  indirect  manner,  produces  the  food  of  the  present  The  parish  of  Barnwell  con- 
tains an  extensive  area  of  these  coprolites  or  fossil  dung. 

The  appearance  of  these  nodules  is  in  shape  various ;  generally  a  hard,  black,  water- 
worn  looking  stone,  with  excrescences;  some  with  convoluted  marks,  bearing  the 
impress  of  the  intestine,  and  rounded  off  at  the  extremities ;  the  surface  of  all  exhibitr 
ing  lines  from  the  decomposition  of  its  more  destructible  component  parts.  Portions 
of  coral,  ammonites,  Crustacea,  sponges,  Ac,  may  be  found  in  the  agglutinated  mass. 
They  vary  in  size  from  a  small  bird's  egg  to  masses  the  size  of  a  fist  A  large  selection 
from  our  own,  as  well  as  from  distant  localities— the  lias  of  Lyme,  the  chalk  of  Farn- 
ham,  the  slate  of  Newhaven,  and  the  crag  of  SuflFolk— are  open  for  the  inspection  of 
those  interested  in  most  geological  collections. 

The  process  which  .they  go  through  to  render  them  available  for  use  is  as  follows:— 
After  being  selected  from  the  soil,  they  are  well  washed  by  rotary  machinery  erected 
on  the  spot,  and  then  conveyed  by  rail  to  the  manufactory,  where  they  are  ground  to  a 
very  fine  powder;  an  operation,  from  their  hardness,  of  no  small  difficulty,  vertical 
granite  and  buhr  stones  being  required.  The  powder  is  mixed  with  about  an  equal 
portion  by  weight  of  strong  sulphuric  acid.  This  is,  I  believe,  a  part  of  the  process 
used  in  the  manufactory  of  Mr.  Lawes,  who  produces  a  very  superior  article,  and  to 
whom  we  are  much  indebted  for  his  early  attention  to  supply  the  increasing  demand 
for  phosphates  as  artificial  manures,  and  who  has  been  supplied  with  thousands  of  tons 
from  digging  over  a  four-acre  field  at  Walton,  in  Suffolk,  the  subsoil  of  which  was  crag, 
producing  to  the  farmer  a  much  richer  harvest  than  grain  at  the  present  free-trade 
prices.  In  an  article  varying,  as  it  necessarily  must,  from  extraneous  matter,  the  com- 
ponent parts  materially  differ.  The  following  analysis  may  be  taken  as  an  average  of 
their  composition,  100  parts  containing — 


Earthy  phosphates 
Carbonate  of  lime  and  iron 
Insoluble   -  -  - 

Moisture    -  -  - 


61 

24 

12 

3 

100 


Mr.  Lawes,  from  a  sample  from  the  same  locality,  made  7  more  parts  of  phosphates, 
and  Mr.  Potter  4  less,  than  the  above  analysis. 

There  is  a  prevalent  idea  that  these  coprolites  are  almost  the  same  as  guano.  This 
is  a  great  mistake ;  for  although  our  own  production  yields  a  larger  proportion  of  the 
phosphates,  it  is  devoid  of  salts  of  urea  and  ammonia,  which,  in  combination  with  the 
phosphates,  increases  to  a  considerable  extent  the  fertilizing  principle  for  which  that 
foreign  article  is  so  celebrated.  It  has  been  the  object  (»f  artificial  manures  to  supply 
Bvnthetically  the  composition  of  guano  at  a  much  reduced  rate. 

'  In  respect  to  the  value  of  coprolites  in  Suffolk,  besides  giving  employment  at  the 
slack  season  to  many  idle  hands,  a  bonus  has  been  given  for  the  right  of  royalty  over  the 
soils,  and  5s.  per  ton  is  paid  the  proprietor  for  all  raised.  This,  with  labor,  washing— 
a  troublesome  and  tedious  process— and  rail  charges  for  delivery  in  London,  costs  from 

35».  to  40».  per  ton.  .  •      ^i.      i.      v 

To  show  the  comparative  value  of  the  different  substances  containing  the  phosphates, 
and  that  of  guano,  an  analysis  of  a  good  sample  is  here  given,  and  that  of  the  phos- 
phates and  carbonate  of  lime  in  various  bones.     That  portion  contained  in  the  fossil 


COPROLITES. 


495 


Analysis  of  Guano  from  Peru. 
Urate  and  salts  of  ammonia 

Various  phosphates  -  -  .  ] 

Carbonate  of  lime  -  -  .  ] 

Soda  and  potash    -  -  . 

Silex  ...."" 

Water  and  indefinite  organic  matter 

Comparative  Analysis  of  Bones. 


-  84-05 

-  87-04 

-  1-65 

-  8-92 

-  4-28 

-  14-06 

100-00 


Phosphates. 


Recent  human  bones 
Ancient  ditto  from  Roman  tumulus 
Fossil  bone  from  the  crag   - 
Recent  ox  bones  -        -        . 

Sheep  bones        .... 
Bones  of  the  hen        -        -        . 

frog        -        -        . 

fishes      -        .        . 


«< 


81-09 
76-38 
60-02 
57-35 
80.00 
88-09 
95-02 
91-09 


Carbonate  of  Lime. 


10-03 
10-13 

18-00 

3-85 

l9-<^)3 

10-04 

2-04 

6-03 


The  foUowing  two  samples  from  the  coast  of  Suffolk  were  found  to  consist  of-. 


Water  with  a  little  organic  matter 
Salts  soluble  in  water  (chloride  of 
sodium  and  sulphate  of  soda)    - 
Carbonate  of  lime 

do.  magnesia 
Sulphate  of  lime  - 
Phosphate  of  lime  (3  Ca  O,  PO^)  - 

do.      magnesia 
Perphosphate  of  iron  (2  Fe'  03 
3P0«)    -  -  .  I 

Phosphate  of  alumina  (2  Al"  03 
3  P0«)    -  .  .  1 

Oxide  of  Manganese 

Fluoride  of  calcium 

Silicic  acid  colored  red  by  a  little 
undecomposed  silicate  of  iron    - 


I 

4-00 

traces 
10-280 

a  trace 

distinct  traces 
70-920=PO5  32-765 
traces  only 

6-850=PO'5  3-244 

1.650=PO5  0-870 

traces 
0-608 

5.792 


IL 
3-560 


8-959 

0-611 
69-099= 


traces 

a  trace 

-P05  31-924 
traces 


8'6I6=P05  4-081 


2-026= 

0-804 

6-309 


-P06  1-158 
traces 


^^^•^^^=-P<^*  36-889  lOO-OOO^POo^Ti^- 

cent  of  nitrogen.  "mmonium,  which  is  equivalent  to  00254  per 

It  is  said  that  the  coprolites  which  Mr   LawA«  Amr^^«^»  •     ^l 
well-known  "  Coprolite  manure."  are  obtled  fTom  the  S  Jffolk  o^"  /"^""^^^^--^  of  his 
character  to  the  above.  ^  tsuffolk  coast,  and  are  similar  in 

In  an  excellent  paper  "  On  the  Phosphoric  Strata  of  fha  r-K  n  t^ 
in  the  first  number  of  the  Journal  T  the  R^^^^^^^ 

for  the  last  year,  Mr.  Way  observes,  that  he  hasTi  n^thT       '  -^  ^^  ^"^^^"^ 

to  contain  from  52  to  54  per  cent  of  bone  earth  nh.  w  ^^P^'^'^^es  froui  this  district 
informed  him,  that  in  se^veral  analyses    vh^rehTd''^^  ''"'?''•  ^'^'^-^  »-<i 

several  tons  of  the  ground  coprolites,  he  hid  found  fh^  ""^  '^™P'^'''  ^^^'^'^^  ^''O'" 
hme  to  vary  between  55  and  57  per  cent  it  T?"t-wr^P''''P^!;^'^"  ^^  phosphate  of 
Part  III  pf  235)  found  from  22-?0  to  28-74  nVrn.nf  ^?"^^  "^r^"'  ^^  ^^''"'-  ^oc 
equivalent  to  from  48-31  to  59  07  of  tribasl/nh  v^S'^^-P'^f  P^^'''^  '^^'^^'  ^^'"'^'^  « 
deposits  of  this  county.  '^^''''  phosphate,  in  those  from  the  tertiary 

^LfLZ.:^^^^^^^^  ?n^d^in1xtvr^-^^  'V  '--''-^■'  ^"* 

bony  structure.     The  specific'gravity  it  waTCnd^m?^-^"^/"/^  evidences  of  a 

of  the  numerous  air  cavities  it  contained  ^'"Possible  to  determine,  on  account 


496 


CORAL. 


CORK. 


497 


I 


Analysis  showed  it  to  possess  the  following  per  centage 

Water  driven  off  at  from  300°  to  350°  F  - 

do.  and  organic  matters  expelled  at  a  red  heat  - 

Chloride  of  sodium,  <fec                -             "  *             ' 

Carbonate  of  lime           -            '            '  '\ 

do.         magnesia         -            '            '  '            ^ 
Sulphate  of  lime              -            " 

Phosphate  of  lime  (tribasic)        -            •  •            ' 

do.        magnesia         '            '           '  ' 
Perphosphate  of  iron      -            - 

Phosphate  of  alumina     "             "             "  ^ 

Peroxide  of  iron               -            "             "  ' 

Alumina              .            -            •            "  " 

Fluoride  of  calcium        .            -            -  • 

Silicic  acid          .            -            -            -  * 


composition  :— 

2-600 
9-000 

evident  traces 

39-500 
0-620 

distinct  traces 
15-860—PO^  5-287 
traces 
.      9-200-=PO''  4-358 
.      4^08— PO^  2-764 
.    •  none 

-  6-212 
.  1-698 
.     10-601 


99-899— P0»  12.4U9 


The  proportion  of  nitrogen  in  this  specimen  was  not  estimated. 

Ill   This  coprolite  was  discovered  in  the  lias  strata  of  Lyme  Regis. 

It  was  rather  large,  being  above  9  ozs.  in  weight,  was  of  a  grayish  color,  and  when 
brolrexh  bited  so^me  traces  of  crystalline  structure.  It  was  considerably  softer  than 
Sr  of  the  preceding,  and  furnished  a  grayish-white  powder.  Many  scales  of  dif- 
ferent ext  net  fishes  and  other  organic  renVains,  were  to  be  perceived  on  the  external 
l^faL  the  sr^^^^^^^^^  proportion  of  them  appeared  to  belong  to  a  species  of  fish  which 
rknown  to  ifhthyo  JgisU  by  the  name  oi  Fholidophorus  hrnbatus  Its  specific  gravity 
wi  about  2-644  or  2-700,  and  the  composition  per  cent  was  as  follows :- 


XL 


Mean. 


Water  driven  off  at  from  300°  to 

350°  F.     -            -            "  ,,  ; 
Water  and  organic  matters  expelled 

at  a  red  heat       -            -  * 

Chloride    of    sodium,    with  some 

sulphate  of  soda  -             -  " 

Carbonate  of  lime   -            -  " 

do.   of  magnesia 
Sulphate  of  lime      - 
Phosphate  of  do.  (tribasic) 


do. 


magnesia 


Perphosphate  of  iron 
Phosphate  of  alumina 
Peroxide  of  iron      -  -  " 

Alumina      -  -  -"    ,  .     " 

Silicic  acid,  with  fluoride  of  calcium 
and  loss  -  -  "  ' 


2-560 

2-668 

2-6140 

3-680 

3-456 

3.5680 

traces 

traces 

traces 

23-640 

23-708 

23-6740 

none 

none 

none 

1-740 

1-801 

1-7705 

60-726 

60-813 

60-7695— P0»  28-047 

a  little 

a  little 

a  little 

3-980 

4-135 

4-0575— PO^  1-922 

a  little 

a  little 

a  little 

2-094 

1-894 

1-9940 

none 

none 

none 

1-580 

1-525 

1-5526 

100-000       100-000 


The  proportion  of  nitrogen  in  this  specimen  was  rather  large,  being  0-0826  per  cent- 

^cT)RrM(7tTFr;;  Koralle,  Germ.)  is  a  calcareous  substance.  {or-dJ>y  ^P^^^^^^ 
of  sea  polvpus,  which  construct  in  concert  immense  ramified  habitations  consisting 
of  an  assen^blage  of  small  cells,  each  the  abode  of  an  animal  The  cora  ^^  therefore  a 
real  poWpary,  which  resembles  a  tree  stripped  of  its  leaves.  It  has  no  roots,  bu  a  foot  not 
unUke  a  hemispherical  skull-cap,  which  applies  closely  to  every  point  of  the  s»»(a«7P«J 
wh  ch  ft  stands,  and  is  therefore  difficult  to  detach.  It  ^^f.^y.rVwnot  o  an  orX 
Tort  to  the  coral,  but  contributes  in  no  manner  to  its  growth,  like  the  root  of  an  ordi- 
Sarv  tree  for  detached  pieces  have  been  often  found  at  the  bottom  of  the  sea  m  a  state  of 
hfcrease  and  reproduction.  From  the  above  base  a  stem,  usually  sing  e.  proceeds,  which 
Ipldors™^^^^  an  inch  in  diameter,  and  from  it  a  small  number  of  branches  rannify  in 
very  TrreX  dir^^  ^Mch  studded  over  with  cells,  each  containing  an  insect 

Th7DoTvf  i  when  they  extend  their  arms,  feelers,  or  tenfacula,  resemble  flowers,  whence. 
Is  well  arfr  Jm  the  fo^rm  of  the  coral,  they  were  classed  among  vegetable  productions. 
Thev  are  now  styled  zoophites  by  the  writers  upon  Natural  History. 

The  fin^st^oral  is  found  in  the  Mediterranean.     It  is  fished  for  upon  the  coasts  of 
Provence,  and  constitutes  a  considerable  branch  of  trade  at  Marseilles.     The  coral  is  at- 

Mn  the  fir^t  of  those  analyses,  the  phosphoric  acid  was  estimated  by  M.  Schulze's  method,  as  per- 
phosphate  of  iron ;  in  the  second,  as  phosphate  of  lead.       - 


lached  to  the  submarine  rocks,  as  a  tree  is  by  its  roots,  but  the  branches,  instead  of 
growing  upwards,  shoot  downwards  towards  the  bottom  of  the  sea ;  a  conformation 
favorable  to  breaking  ihem  ofl'  and  bringing  them  up.  For  this  kind  of  fishing,  eight 
men,  who  are  excellent  divers,  equip  a  felucca  or  small  boat,  called  commonly  a  coral- 
line. They  carry  with  them  a  large  wooden  cross,  with  strong,  equal,  and  long  arms, 
each  bearing  a  stou^  oag-net.  They  attach  a  strong  rope  to  the  middle  of  the  crosa^ 
and  let  it  down  horizontally  into  the  sea,  having  loaded  its  centre  with  a  weight  sufficient 
to  sink  it  The  diver  follows  the  cross,  pushes  one  arm  of  it  after  another  into  the  hol- 
lows of  the  rocks,  so  as  to  entangle  the  coral  in  the  nets.  Then  his  comrades  in  the  boa! 
pull  up  the  cross  and  its  accompaniments. 

Coral  fishing  is  nearly  as  dangerous  as  pearl  fishing,  on  account  of  the  number  of  shark| 
which  frequent  the  seas  where  it  is  carried  on.  One  would  think  the  diving-bell  in  its 
now  very  practicable  slate  might  be  employed  with  great  advantage  for  both  purposes. 

Coral  IS  mostly  of  a  fine  red  color,  but  occasionally  it  is  flesh-colored,  yellow,  or  white. 
The  red  is  preferred  for  making  necklaces,  crosses,  and  other  female  ornaments.  It  il 
worked  up  like  precfeus  stones.    See  Lapidary. 

CORK  (Liege,  Fr. ;  Kork,  Germ.)  is  the  bark  of  the  quercus  liber,  Linn.,  a  species  of 
oak-tree,  which  grows  abundantly  in  the  southern  provinces  of  France,  Italy,  and  Spain. 
The  bark  is  taken  off*  by  making  coronal  incisions  above  and  below  the  portions  to  be 
removed;  vertical  incisions  are  then  made  from  one  of  these  circles  to  another, whereby 
the  bark  may  be  easily  detached.  It  is  steeped  in  water  to  soften  it,  in  order  to  be  flat- 
tened by  pressure  under  heavy  stones,  and  next  dried  at  afire  which  blackens  iU surface. 
The  cakes  are  bound  up  in  bales  and  sent  into  the  market. 

There  are  two  sorts  of  cork,  the  white  and  the  black ;  the  former  grows  in  France  and 
the  latter  m  Spain.  The  cakes  of  the  white  are  usuaUy  more  beautiful,  more  smooth, 
lighter,  freer  from  knots  and  cracks,  of  a  finer  grain,  of  a  yeUowish  gray  color  on  both 
sides,  and  cut  more  smoothly  than  the  black.  When  this  cork  is  burned  in  close  vessels 
It  forms  the  pigment  called  Spanish  black. 

This  substance  is  employed  to  fabricate  not  only  bottle  corks,  but  small  architectural 
and  geognostic  models,  which  are  very  convenient  from  their  lightness  and  solidity. 

The  cork-cutters  divide  the  boards  of  cork  first  into  narrow  fillets,  which  they  after 
wards  subdivide  into  short  parallelopipeds,  and  then  round  these  into  the  proper  conical 
or  cylindrical  shape.  The  bench  before  which  they  work  is  a  square  table,  where  4 
workmen  are  seated,  one  at  every  side,  the  table  being  furnished  with  a  ledge  to  prevent 
the  corks  from  falhng  over.  The  cork-cfu tier's  knife  is  a  broad  blade,  very  thin,  and  fine 
edged.  It  is  whetted  from  time  to  time  upon  a  fine-grained  dry  whetstone.  The  work- 
man ought  not  to  draw  his  knife  edge  over  the  cork,  for  he  would  thus  make  misses,  and 
might  cut  himself,  but  rather  the  cork  over  the  knife  edge.  He  should  seize  the  knife 
with  his  left  hand,  rest  the  back  of  it  upon  the  edge  of  the  table,  into  one  of  the  notches 
made  to  prevent  it  from  slipping,  and  merely  turns  its  edge  sometimes  upright  and  some- 
times to  one  side.  Then  holding  the  squared  piece  of  cork  by  its  two  ends,  between  his 
finger  and  his  thumb,  he  preseats  it  in  the  direction  of  its  length  to  the  edge  :  the  cork  is 
now  smoothly  cut  into  a  rounded  form  by  being  dexterously  turned  in  the  hand.  He  next 
cuts  ofl- the  two  ends,  when  the  cork  is  finis;hed  and  thrown  into  the  proper  basket  along. 
6iae,  to  be  afterwards  sorted  by  women  or  boys. 

Of  late  years  a  much  thicker  kind  of  cork  boards  have  been  imported  from  Catalonia, 
from  which  longer  and  better  corks  may  be  made.  In  the  art  of  cork-cutting  the  French 
surpass  the  English,  as  any  one  may  convince  himself  by  comparing  the  corks  of  their 
champagne  bottles  with  those  made  in  this  countrj% 

Cork,  on  account  of  its  buoyancy  in  water,  is  extensively  employed  for  making  floats 
to  fishermen's  nets,  and  m  the  construction  of  life-boats.  Its  impermeability  to  water  nas 
\ed  to  its  employment  for  inner  soles  to  shoes. 

When  cork  is  rasped  into  powder,  and  subjected  to  chemical  solvents,  such  as  alcohol, 

&c.,  It  leaves  70  per  cent,  of  an  insoluble  substance,  called  suberine.     When  it  is  treated 

,  with  nunc  ac.d    it  yields  the  following  remarkable  products:  —  White  fibrous  matter 

0-18,  resm  14-72,  oxahc  acid  16-00,  suberic  acid  (peculiar  acid  of  cork)  14-4  in  100 

parts.  ^  *-*  •*  »"  *wv 

Machine  cork-cutting.  —  A  patent  was  obtained  some  years  ago  by  Sarah  Thomson  for 
this  purpose.  The  cutting  of  the  cork  into  slips  is  effected  by  "fixing  it  upon  the  sliding 
bed  of  an  engine,  and  bnngmg  it,  by  a  progressive  motion,  under  the  action  of  a  circular 
knife,  by  which  it  is  cut  into  slips  of  equal  widths.  The  nature  or  construction  of  a 
rnachine  to  be  used  for  this  purpose  may  be  easily  conceived,  as  it  possesses  no  new  me- 
chanical  feature,  except  m  its  application  to  cutting  cork.  The  motion  communicated 
w  me  Knife  by  hand,  steam,  horse,  or  other  power,  moves  at  the  same  time  the  bed  also 
Which  carries  the  cork  to  be  cut. 

The  second  part  of  the  invention,  viz.,  that  tor -Separating  the  cork  into  square  pieces 
alter  it  has  been  cut  into  slips  as  above,  is  effected  by  a  moving  bed  as  before,  upon  which 


498 


COTTON  DYEING. 


i  I 


V 


the  slips  are  to  be  placed  and  submitted  to  the  action  of  a  cntfinc  i.^         i,-  v 
regulated  to  chop  the  cork  into  pieces  of  any  given  len/tb  ^     '^'''  ^^'""^  "''^^  ^ 

Ihe  third  part  of  the  invention,  viz.,  that  for  rounding  or  finishin.,  th.       % 
of  an  engine  to  which  is  attached  a  circular  knife  that  turns  vlr«?i.^  *'T^''  ^^""'"^ 
or  frame  upon  its  side  that  revolves  on  its  axle  horizon tlZ         ''''"^'  "^^  *  «""««« 

a  pTet  :rt;74.::rert^erb^^^^^^^^  f -<^^!^  -peetively  to  hold 

pendicularlj ;  which  c^rps  arTcrntXd  to  hav.  11^  ^f  'T^'"^  '^  lengthways  per- 
at  the  low  J'end  of  their  a^xlesTrrlin^ln^'^:;^^^^^^^^     "^^^^^"'  ^^  "^^^  ^^^  P-- 

orrn^Xr'SiVtVew^^^^^^^ 

the  circular  knife  revolvesTertic^l  v  tLfr^^.  .  ^-'^'^^^l  ^'l^  ^^  ^^"  ««™^  ^ime  that 
cork,  turns  horizontal! jXin.Tnrt^h^^  containing  the  clamps  with  the  pieces  of 

to  render  each  piece  of  cork  of  ,"nHrt„? Tk  i  ^^  """^  "P  *^  *^^  ^^^^  ^^  ^^^  knife,  when, 
axes,  independ^t^;  of  ?heir^e^^^^^^^^^  "^^Tf  ^^^scribed,  revolve  upon  thei; 

cork  is  brought  under  the  action  l^fLT  v  !u  ""^^"«  ^^^  whole  circumference  of  the 
off,  and  the  f ork^finfsVetroTh Id  ytti^  '""^iToZS^:''  ?"  T^'T'^  ^'^'^ 
Bumption  amount*  to  about  2200  tons  /e7an"  urn  ^  ^  '"^""'^  ^^^  ^^™'  ^*^°- 

CORROSIVE  SUBLIMATF-  k;«m^^-I  *°!^"™- 

CORUNDriM  '^^iJ.^^^.^AJ^;  bichloride  of  mercury. 


COTTON  FACTORY. 


Alumina 
Lime 
Silica     - 
Oxide  of  iron 


Blue  Sapphire, 
China. 


98-5 
0-5 
0-0 
10 


84-0 

0-a 

6-6 

7-6 


Corundum, 
Bengal 


89-5 
0-0 
6-6 
1.25 


Emery, 
Naxoa. 


86-0 
3  0 
8-0 
4-0 


100-0  Klapr.    |       980  Chen.     |  982  Tennent    |  96-0  Tennent. 


The  perfectly  white  crystals  of  sapphire  are  pure  alumina. 

OrlnTal  r^brofTl^rtheSa^^^^^^^^^^^  ^^^/^hire  so  called,  and  the 

3-97.     Their  form  is  a  Si v  acute  rhomho;^      1m  'P'"'^"  ^'l''^^^'  ^^'"^  ^'^  «g«in«t 
inferior  in  hardness  onlyfo  tL  di^^^^^^^  ^T ^'-^  ''^'^^'T'  ^"^  ^« 

COTTON    nvvmr      ,>W'7       ^'     i*^^  ^^PP"'^^  occurs  also  in  6-8ided  prisma 
CoVton    an?  hSen  yfrS    and" doth.  Iv^'"'  ^^'ll     ^---^-^-llen/arberei,  ^Gen^.) 
may  therefore  wrh^propriety  be  t  e^^^         T/ Ln^%  T'.."®"^^^./^^  ^>'^^'   ^"^ 

=U  reSi^H^^S^^^^  ^^^^^ 

^s;Xi-^^l^{=^       rr^^^^^ 

fix  these  particles  so  that  thevVm  not  ^^^  ?''f^  'f^  ''^""^"^^  properties  as  wiU 
be  subjected     All  tL  ^nL     ^u^i  •  separate,  to  whatever  ordinary  trial  they  mav 

tunal  ydonotZe^sth^^^^^^^^  ^"^'^  bedesirable  to  transfer  to  these  stuffs  unTor! 

constancy  a^eHt  the  dfscovTr^^^^^^^^^^  ^"'^  °^  '"'"'"  ""^"^"^  ^"  '^''  ^"^PO'-^^"t  art  have 
of  fast  colo^  those  dyes  whTr.7  fr^.T  "'"^  ^'■^'''''^  ^^^"^  "^^^  ^^^"^^^'^  ^^^o  the  class 
goods  manufactu?^  of  cotTon  flax  or  hemn  ^^-'.^^n  ^""z"'^''  ^^'"^^^  ^»  ^^« 
therefore,  to  be  so  dyed  as  to  Jesi  J'the  nH'  ^"^'""^^  ^**  ?^  ''^'^^^'  ^"'i  «"gt»^ 
the  laundry.  Vitalis  distin°u?she1  HvZl  Jn.t  ^l'^  '^^^^  '°^"^'°"^  commonly  used  in 
fancy-colored   (pefitteint)   "^^^^^^^  'v^^  ^^^^  ^^^^^^^5  1.  the  >^7i>e,  or 

boils  with  soapr2    ho  fwhiTh  re  J^^^^^^  ^^V  T  ^''''''^'^  ^^  ^^ ''  ^^o 

fast  colors  (^rand  teint)        T^Tll^l  ^^Brt^^^^  may  be  called 

Kie fugitive;  those  made  with  madd^wkhnnf^  ^^1^°^"^^' "^^^^^^^  safflower,  &c., 
der  with  an  oily  mordant,  a  e  A^/It^  hoi?  ^''^  ^"-l^'  ^""^  «^«^'^''  ^"'I  those  of  mad^ 
for  giving  theseVerentW^^^^^^^  t::^'i^::^^ ^^^^'  -^  -^-  P-esses 

atiLtf"ci^T^^p;,r^^^^^^^^^  Parag^phs,  the  oper'aSs  conducive  to  the  fix- 

J;mpt:'d^otvV[^^^^^^^^^^  S^eTeptatr  ^2  i'rlV^^  ^"^  1^?  ""'^^''' 

pound  of  cotton,  being  coarseLf  pounded   are?o  hpn^:*  •  .         "^"""^  of  galls  for  every 

30  gallons  of  water  fof  over,  loVpo^s^r^tl'TaaXri:?^^^^ 


I*-- 
•> 


499 


of  galls  feel  pasty  between  the  fingers.  The  fire  being  withdrawn,  when  the  bath  becomes 
moderately  cool,  it  is  passed  through  a  hair-cloth  sieve.  If  during  this  operation  the 
liquor  should  become  cold,  it  must  be  made  once  more  as  hot  as  the  hand  can  bear.  A 
portion  of  it  is  now  transferred  into  another  vessel,  called  a  back,  in  which  the  cotton  is 
worked  till  it  be  well  penetrated  with  the  decoction.  It  is  then  taken  out,  wrung  at  the 
peg  or  squeezed  in  a  press,  and  straightway  hung  up  in  the  drying-houst.  Some  more 
of  the  fresh  decoction  being  added  to  the  partially  exhausted  liquor  in  the  back,  the  pro 
cesj  is  resumed  upon  fresh  goods. 

The  manipulation  is  the  same  with  sumach,  but  the  bath  is  somewhat  differently  made; 
because  the  quantity  of  sumach  must  be  double  that  of  galls,  and  must  be  merely  infused 
in  very  hot  water,  without  boiling.  When  galls  and  sumach  are  both  prescribed,  their 
baths  should  be  separately  made  and  mixed  together. 

2.  »4Iuming.  Alum  is  a  salt  which  serves  to  prepare  cotton  for  receiving  an  indefinite 
variety  of  dyes.  Its  bath  is  made  as  follows  :  For  100  pounds  of  scoured  cotton,  about 
30  gallons  of  water,  being  put  into  the  copper,  are  heated  to  abou  .2^^.,  when  4  ounces 
of  alum,  coarsely  pounded,  are  thrown  in  for  every  pound  of  cotton,  and  instantly  dis- 
solved. Whenever  the  heat  of  the  bath  has  fallen  to  about  98°  F.,  the  cotton  is  well 
worked  in  it,  in  order  that  the  solution  may  thoroughly  penetrate  all  its  pores.  It  is  then 
token  out,  wrung  at  the  peg  or  squeezed  in  the  press,  and  dried  in  the  shade.  The  solu- 
tion of  alum  is  of  such  constant  employment  in  this  kind  of  dyeing,  that  it  should  be 
made  in  large  quantities  at  a  time,  kept  in  the  alum  tun,  where  it  can  suffer  no  deteriora 
tion,  and  drawn  off  by  a  spigot  or  stop-cock  as  wanted. 

There  are  certain  colors  which  require  alum  to  be  deprived  of  a  portion  of  its  acid  ex- 
cess, as  a  supersalt;  which  may  be  done  by  putting  1  ounce  of  crystals  of  soda  into  the 
tun  for  every  pound  of  alum.  But  so  much  soda  should  never  be  used  as  to  cause  any 
permanent  precipitation  of  alumina.  When  thus  prepared,  it  is  called  saturated  alum 
though  It  is  by  no  means  neutral  to  litmus  paper;  but  it  crystallizes  differently  from  ordi- 
nary alum. 

Cotton  does  not  take  up  at  the  first  aluming  a  sufficient  quantity  of  alum ;  but  it  must 
receive  a  second,  or  even  a  third  immersion.  In  every  case  the  stuff  should  be  thoroughly 
dried,  with  an  interval  of  one  or  two  days  between  each  application  ;  and  it  may  even  be 
left  for  10  or  12  hours  moist  with  the  alum  bath  before  being  hung  in  the  air.  When 
the  cotton  is  finally  dry,  it  must  be  washed  before  being  plunged  into  the  dye  bath ;  other- 
wise, the  portion  of  alum  not  intimately  combined  with  the  cotton,  but  adherin*  exter- 
nally to  its  filaments,  would  come  off  by  the  heat,  mix  with  the  bath,  alter  th'i  color 
by  dissolvmg  in  it,  and  throw  it  down  to  the  bottom  of  the  copper,  in  the  form  of  a  lake 
to  Ihe  great  loss  of  the  dyer.  Madder  reds,  weld  yellows,  and  some  other  colors  are 
more  brilliant  and  faster  when  acetate  of  alumina,  prepared  with  acetate  of  lead  alum 
and  a  little  potash,  is  used,  than  even  saturated  alum.  This  mordant  is  emnloved  cold' 
and  at  4°  Ban  me.  ^    "'  » 

3.  Mordants.     See  this  article  in  its  alphabetical  place. 

4.  Dye  baths  are  distinguished  into  two  classes;  the  coloring  bath,  and  the  dyein«'bath 
The  former  serves  to  extract  the  coloring  matters  of  the  different  substaiu.cs  wfth  the 
exception  of  madder,  which  is  always  used  in  substance,  and  never  as  an  extract  infu- 
sion, or  decoction.  In  all  these  cases,  when  the  color  is  extracted,  thai  is  wnen  the  dye 
bath  IS  completed  by  the  degree  of  heat  suited  to  each  substance,  ii  is  tnen  allowed  to 
cool  down  a  certain  way,  and  the  cotton  is  worked  or  winced  through  ii,  to  tH  ihe  wished 
for  tmt.      This  is  what  is  called  the  dye  bath.      Several  coloring  batns  are  made  in  the 

^nli'  *  r  ^,  ^  ^^""^^  *°  ^^^  "^^®  ^"  *^^  ^^^^  5  ^"^  ^^®  greater  part  require  a  heat  of  90°  or 
100°  to  facilitate  the  penetration  of  the  stuffs  by  the  coloring  particles.  The  descriotion 
of  the  several  dye  baths  is  given  under  the  individual  dyes. 

5.  Of  the  washing  after  the  dyeing.— The  washing  of  the  cottons  after  they  have  re- 
ceived the  dyes,  is  one  of  the  most  important  operations  in  the  business.  If  it  is  not  care- 
ruUy  performed,  the  excess  of  color  not  combined  with  the  fibres  is  apt  to  stain  whatever 
It  touches.  This  inconvenience  would  be  of  little  consequence,  if  the  friction  carried 
off  the  color  equaLy  from  all  the  points ;  but  it  does  not  do  so,  and  hence  the  surface  ap- 
pears mottled.  A  well-planned  dye  house  should  be  an  oblong  gallery,  with  a  stream  of 
wrater  flowing  along  m  an  open  conduit  in  the  middle  line,  a  sWies  of  dash-wheels  ar- 
ranged against  the  wall  at  one  side,  and  of  dyeing  coppers,- furnished  with  self-acting 
jrincps  or  reels  against  the  other.  In  such  a  gallery,  the  washing  may  be  done  either  by 
hand,  ny  the  rinsing  machine,  or  by  the  dash-wheel,  according  to  the  quality  of  the  dve 
ind  the  texture  of  the  stuffs.  And  they  may  be  stripped  of  the  water  either  by  the  jack 
and  pin,  by  the  squeezin?  roller,  or  by  the  press.  Wooden  pins  are  placed  in  some  dye 
houses  on  each  side  of  the  wash  cistern  or  pool.  They  are  somewhat  conical,  U  foot 
high  3i  inches  in  diameter  at  the  base,  1|  at  the  top,  are  fixed  firmly  upright,  and  at  a 
level  of  about  3  feet  above  the  bottom  of  the  cistern,  so  as  to  be  handy  for  the  workmen. 


500 


COTTON  FACTORY. 


COTTON  FACTORY. 


501 


1^ 


See  Brazil  Wood,  Fustic,  Madpek,  Black  Dye,  Brown  Dye.  <to     ns  «]««  P 

Br.vn,  Caluo  Print.ng.  Dcnging.  Dyking.  <fec  ^        '  '"''  ^^'^  ^^^^^ciiing. 

CW/on  may  he  distinguished  from  Linen  in  a  cloth  fabric  by  means  of  a  (rood  m\or 
soopo ;  tl.e  foniK-r  fibres  being  flat,  riband-like  and  more  or  less  contorted  or  shrivXT 
and  the  latter  straight,  round,  and  with  cross  knots  at  certain  distances  Thesp  twn 
hbrons  .natters  may  be  also  distinguished  by  the  action  at  a  boiling  heat  of  a  strnn^ 
caustic  ve.  made  by  dissolving  fused  potash  in  its  own  weight  of  water.  By  dic.e«Hnn 
in  this  liquor,  l.nen  yard  becorries  immediately  yellow,  while  the  cotton  yaVn  r?ma  ns 
white.  The  best  way  of  operating  is  to  immerse  a  square  inch  of  the  cloth  to  be  tested 
for  two  minutes  in  the  above  boiling  hot  caustic  \ye,  to  lift  it  out  on  a  glass  rod  Tre^ 
I  dry  between  folds  of  blotting-paper,  and  then  to  pull  out  a  few  of  the  warp  and  weft 
threads-when  he  linen  ones  will  be  found  of  a  deep  yellow  tint,  but  the  cotton  whUe 
or  very  pale  yellow.  ^-wi-iwu,  wane 

f ,v?f "^^  (f  ^^a^^-^^cf).     The  merfiurized  cotton,  as  it  has  been  called,  is  chemically  iden- 

o^t  r-  1  ''''^"'?''  .^k"^  '"'^"^^  ^^  ^''^^"S  ^^  fi^^^^«  «^t^"«^  «"d  twisted,  it  hal  hem 
cyhndncal,  as  seen  m  the  microscope.     In  fact,  the  moment  they  are  touched  by  the 

aftpr  thir/  '^  untwist  themselves,  contract  in  length,  and  retain  the  rounded  form 
after  the  soda  is  removed  by  washing.  We  can  thus  conceive  how  a  larger  quantity  o7 
dye  may  be  imbibed,  as  the  substance  becomes  more  porous.     The  formula  of  the 

rmpToye"""  "  ''"'"  ^^  ^''  ^^^'^^^°^  ^  ^-  ^-  ^-  ^^'  -^-^  P^^-^  Ts  the  al kail 

COTTON  FACTORY  {General  Construction  o/).-There  is  no  textile  rubstance 
whose  filaments  are  so  susceptible  of  being  spun  into  fine  threads  of  uniform  tw"sL 
strength,  and  diameter,  as  cotton  wool.  It  derives  this  property  from  the  srao^thne^ 
tenacity  flexibility,  elasticity,  peculiar  length,  and  spiraffor^m  of  thellarnuThen^ 
when  a  few  of  them  are  pulled  from  a  heap  with  the  fingers  and  thumb,  they  lay  hold 
of  and  draw  out  many  others.  Were  they  much  longe?  they  could  not  be  so  readX 
attenuated  into  a  fine  thread,  and  were  they  much  shorter  the  thread  would  be  deficient 
n  cohesion.  Even  the  differences  in  the  lengths  of  the  cotton  staple  are  of  advantage 
in  adapting  them  to  different  styles  of  spinning  and  different  textures  of  cloth  ^ 

♦],:\.r  1  f  1  ^  \  \  ''''\^''''  '^''''^  '"  ^^'^  ^^^^  ^"°*^'  °°^  ««'^'"g  t^e  projecting  fibres  with 
the  right  slowly  draw  them  out,  we  shall  perceive  with  whSt  r.^'aikable  facility  they 
glide  past  each  other,  and  yet  retain  their  mutual  connexion,  while  they  are  extended 
and  arranged  m  parallel  lines,  so  as  to  form  a  little  riband  susceptible  of  considerable 
elongation.  This  demonstration  of  the  ductility,  so  to  speak,  of  ^cotton  wool,  succeeds 
still  better  upon  the  carded  fleece  ,n  which  the  filaments  have  acquired  a  certain 
parallelism;  for  m  this  case  the  tiny  riband  in  being  drawn' out  by  the  fingers  to  a 
moderate  length,  may  at  the  same  time  receive  a  gentle  twist  to  preserve  ite  cohesion 
till  It  becomes  a  line  thread. 

Hence  we  may  imagine  the  steps  to  be  taken  or  the  mechanical  processes  to  be 
pursued  in  cotton  spinning  After  freeing  the  wool  of  the  plant  from  all  foreign 
substances  of  a  lighter  or  a  heavier  nature,  the  next  thing  is  to  arrange  the  filaments  in 
lines  as  parallel  as  possible,  then  to  extend  them  into  regular  ribands^  to  elongate  the  e 
ribands  by  many  successive  draughts,  doubling,  quadrupling,  or  even  octupling  them 
meanwhile  so  as  to  give  them  perfect  equality  of  size,  consistence  and  texturef  and  at  the 
same  time  to  coniplete  the  parallelism  of  the  fibres  by  undoing  the  natural  cinvolutiona 

tlnfrr  •"  ?f  ^;f  •     ^^^'"  '^'  ^^^'•""^«'*  ^^^^"«'«"  ^««  ^^^^  thus  carried  to  the 
fineness  required  by  the  spinner,  or  to  that  compatible  with  the  staple,  a  slight  degree 

l^ZnT  '""-^  f,<^«r,P""^  ^^''  ^"^^'^^^  attenuation;    which  torsiLn  may\e  either 
Finn  W  ;?'  "'  '"  ^^''  ^V^'  ''^'"-  ™^"^^"^'  «^  permanent,  as  in  the  bobbin  and  fly  frame 
fwl  !^V  •  .'  T'FT^^^  attenuated  soft  thread,  called  a  fne  roving,  is  drawn  out  and 
«ri  fwl"r     ^"'^^^^„«°^t,«"  yr".  either  by  continuous  indefinite  gradations  of  drawing 

lenit  ^n    '^;-"'  '"  ''"  !''"'''';  "'  ^^  B^ecessive  stretches  and  toTsions  of  considerablf 
Jengtlis  at  a  time,  as  in  the  mule. 

Mechanical  spinning  consists  in  the  suitable  execution  of  these  different  processes  by 
a  seres  of  different  machines  After  the  carding  operation,  these  are  made  to  ac^ 
simultaneously  upon  a  multitude  of  ribands  and  spongy  cords  or  threads  by  a  multitude 
of  meehnnieal  hands  and  fingers.  However  simple  and  natural  the  above  descr  bed 
course  of  manulacLure  may  appear  to  be,  innumerable  difliculties  stood  for  ages  in  the 
way  of  Its  accomplishment,  and  so  forn.idable  were  they  as  to  render  their  entire 

In' M        ;'•'  ^'"''^  '"f  k'  '"''*'"  ^"'-'"^'^^  ^^  ^°S^«"^  «»«  of  '^^  greatest  and  most 
honorable  achievements  of  human  geniu3.  ^^  mwoi. 

1  The  cleaning  ami  oj.ening  up  or  loosening  the  flocks  of  cotton  wool,  as  imported 
in  the  bags,  so  as  to  separate  at  once  the  coarser  and  heavier  impurities  as  well  as  those 
of  a  lighter  and  liner  kind.  *  ' 


J 


2.  The  carding,  which  is  intended  to  disentangle  every  tuft  or  knot,  to  remove  every 
remaining  impurity  which  might  have  eluded  the  previous  operation,  and  finally  to 
prepare  for  arranging  the  fibres  in  parallel  lines,  by  laying  the  cotton  first  in  a  fleecy  web, 
and  then  in  a  riband  form. 

8.  The  doubling  and  drawing  out  of  the  card-ends  or  ribands,  in  order  to  complete  the 
parallelism  of  the  filaments,  and  to  equalize  their  quality  and  texture. 

4.  The  roving  operation,  whereby  the  drawings  made  in  the  preceding  process  are 
greatly  attenuated,  with  no  more  twist  than  is  indispensable  to  preserve  the  uniform 
continuity  of  the  spongy  cords;  which  twist  either  remains  in  them,  or  is  taken  out 
immediately  after  the  attenuation. 

5,  The  fine  roving  and  stretching  come  next ;  the  former  operation  being  effected  by 
the  fine  bobbin  andf  fly  frame,  the  latter  by  the  stretcher  mule. 

^  6u  The  spinning  operation  finishes  the  extension  and  twist  of  the  yam,  and  is  done 
cither  in  a  continuous  manner  by  the  water  twist  and  throstle,  or  discontinuously  by 
the  mule;  in  the  former,  the  yarn  is  progressively  drawn,  twisted,  and  wound  upon  the 
bobbins;  in  the  latter  it  is  drawn  out  and  twisted  in  lengths  of  about  56  inches,  which 
are  then  wound  all  at  once  upon  the  spindles. 

7.  The  seventh  operation  is  the  winding,  doubling,  and  singeing  of  the  yams,  to  fit 
them  for  the  muslin,  the  stocking,  or  the  bobbin  net  lace  manufacture. 

8.  The  packing  press,  for  making  up  the  yarn  into  bundles  for  the  market,  concludes 
this  series. 

9.  To  the  above  may  be  added  the  operations  of  the  dressing  machines,  and, 

10.  The  power-looms. 

The  site  of  the  factory  ought  to  be  carefully  selected  in  reference  to  the  health  of  the 
operatives,  the  cheapness  of  provisions,  the  facilities  of  transport  for  the  raw  materials, 
and  the  convenience  of  a  market  for  the  manufactured  articles.  An  abundant  supply 
of  labor,  as  well  as  fuel  and  water  for  mechanical  power,  ought  to  be  primary  con- 
siderations in  setting  down  a  factory.  It  should  therefore  be  placed,  if  possible,  in  a 
populous  village,  near  a  river  or  canal,  but  in  a  situation  free  from  marsh  malaria, 
and  with  such  a  slope  to  the  voider  stream  as  may  ensure  the  ready  discharge  of 
all  liquid  impurities.  These  circumstances  happily  conspire  in  the  districts  of  Stock- 
port, Hyde,  Stayleybridge.  Duckenfield,  Bury,  Blackburn,  Ac,  and  have  eminently 
favored  the  rapid  extension  of  the  cotton  manufactures  for  which  these  places  are  pre- 
eminent 

Mr.  OrrelPs  Cotton  Factory.— The  mill  consists  of  a  main  body  with  two  lateral 
wings,  projecting  forwards,  the  latter  being  appropriated  to  store-rooms,  a  counting- 
S.?"*u  Mj^'"^  ^^^  winding  the  yarn  on  bobbins,  and  other  miscellaneous  purposes. 
The  building  has  6  floors  besides  the  attic  story.  The  ground-plan  comprehends  a  plot 
of  ground  280  feet  long  by  200  feet  broad,  exclusive  of  the  boiler  sheds. 

The  right-hand  end,  a  {fg.  389)  of  the  principal  building,  is  separated  from  the  main 
body  by  a  strong  wall,  and  serves  in  the  three  lower  stories  for  accommodating  two 
nmety-horse  steam  engines,  which  are  supplied  with  steam  from  a  range  of  boilers 
contained  in  a  low  shed  exterior  to  the  mill. 

The  three  upper  stories  over  the  steam  engine  galley  are  used  for  unpacking,  sorting, 
picking,  cleaning,  willowing.  batting,  and  lapping  the  cotton  wool.  Here  are  the 
willow,  the  blowing,  and  the  lap  machines,  in  a  descending  order,  so  that  the  lap 
machine  occupies  the  lowest  of  the  three  floors,  being  thus  most  judiciously  placed  on 
the  same  level  with  the  preparation  room  of  the  building.  On  the  fourth  main  floor  of 
the  factory  there  are,  in  the  first  place,  a  line  of  carding  engines  arranged,  near  and 
parallel  to  the  windows,  as  shown  at  b,  b,  in  the  ground  plan  (Jig.  3891  and,  in  the 
second  place,  two  rows  of  drawing  frames,  and  two  of  bobbin  and  fly  frames,  in  alternate 
lines,  parallel  to  each  other,  as  indicated  by  d.  c,  d,  c,  for  the  drawing  frames,  and 
B,  K.  K,  K,  for  the  bobbin  and  fly  frames  in  the  ground  plan.  The  latter  machines  are 
close  to  the  centre  of  the  apartment 

The  two  stories  next  under  the  preparation  room  are  occupied  with  throstle  frames, 
distributed  as  shown  at  f.  f.  in  the  ground  plan.  They  stand  in  pairs  alongside  of 
each  other,  whereby  two  may  be  tended  by  one  person.  These  principal  rooms  are 
280  feet  long,  and  nearly  50  feet  wide.  The  two  stories  over  the  preparation  room,  vizL, 
the  fifth  and  sixth  floors  from  the  ground,  are  appropriated  to  the  mule  jennies,  which 
are  placed  in  pairs  fronting  each  other,  so  that  each  pair  may  be  worked  by  one  man. 
Their  mode  of  distribution  is  shown  at  o  o,  in  the  ground-plan.  The  last  single 
mule  18  seen  standing  against  the  end  wall,  with  its  head-stock  projecting  in  the 
middle.  ^   ''        ^ 

The  ground  floor  of  the  main  building,  as  well  as  the  extensive  shed  abutted  behind 
It,  marked  by  n,  h,  h,  in  the  plan,  is  devoted  to  the  power  looms,  the  mode  of  placing 
v;hich  IS  plainly  seen  at  h,  h,  h.  .  "^         ® 


n 


502 


COTTON  FACTORY. 


889 


>•  > 


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I  *  * 


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3°    I— t;— i-c— I     C 


10    0  ao  io» 

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890 


i 


. 


COTTON  FACTORY. 


891 


808 


iiaiaiatid 


I  [□  [a  im  PI  la 

itaiiaijapu 
iiaiaiai 

i[aini.[ai[a 


IRREGULAR  PAGINATION 


I 


504 


COTTON  FACTORY. 


The  attic  story  accommodates  the  warping  mills,  and  the  warp  dressing  machines 
subservient  to  power  weaving.  ^  ^  macnmea 

^u"^^  winding  machines,  and  some  extra  mules  (self-actors)  are  placed  in  the  winffs 
the  live  winding  machines  being  in  the  two  top  rooms  of  the  left  wing. 
We  shall  briefly  sum  up  the  references  in  the  ground-plan  as  follows: 

A,  the  grand  apartment  for  the  steam  engines. 

B,  the  distribution  of  the  carding  engines,  the  moving  shaft  or  axis  runDine  in  a 
straight  line  through  them,  with  its  pulleys  for  receiving  the  driving  bands. 

c,  c,  the  drawing  frames. 

D,  D,  the  jack,  or  coarse  bobbin  and  fly  frames. 

E,  E,  the  fine  roving  or  bobbin  and  fly  frames. 

the^d'anTsd  fl^aT^"'  ""^  ^^^  throstle  frames,  standing  in  pairs  athwart  the  gallery,  in 

G  the  mules  are  here  represented  by  their  roller  beams,  and  the  outlines  of  their  head- 
stocks,  as  placed  in  the  5th  and  6th  stories. 

H,  the  looms  with  their  driving  pulleys  projecting  from  the  ends  of  their  main  axes. 
Sometimes  the  looms  are  placed  in  parallel  straight  lines,  with  the  rigger  pulleys  of  the 
one  alternately  projected  more  than  the  other,  to  permit  the  free  play  of  the  driying- 
belte ;  sometimes  the  looms  are  placed,  as  generally  in  this  engraving,  alternately  to  the 
right  and  left,  by  a  smal  space,  when  the  pulleys  may  all  project  equally.  The  former 
plan  18  the  one  adopted  in  Mr.  Orrell's  mill.  J       f   J        H      J  »"^'^*r 

I,  represents  the  cast-iron  girders  which  support  the  floors  of  this  fire-proof  building. 

f V^f*  f V"-!f  Ttu  ^If^  "^  S;^^  ^rr*  •"  *^^  ^•^^"^^^  «^  »  ^'°<^  of  pilasters  built  againit 
«ie  outside  of  the  edifice.  These  hollow  shafts  are  joined  at  top  by  horizontal  pipes, 
which  all  terminate  in  a  chest  connected  with  the  suction  axes  of  a  fan,  whereby  T  con- 
stant draught  of  air  circulates  up  the  shafts,  ventilates  the  apartments,  and  prevents  the 
reflux  of  oflfensiye  effluvia  from  the  water-closets,  however  careless  the  work-people  may 
be.  Tlie  tunnels  toward  the  one  end  of  the  building  are  destined  for  the  men;  to- 
ward  the  other  for  the  women.  ' 

L,  L,  are  the  staircases,  of  a  horse-shoe  form,  the  interior  space  or  shaft  in  the  middle 

being  used  for  the  teagle  or  hoist     In  the  posterior  part  of  the  shaft  a  niche  or  groove 

latform         ^^'""^^^-^^'g'^^^  ^^  ^^'^^  i°.  <>"*  of  the  way  of  the  ascending  and  descending 

M,  M,  are  the  two  porters'  lodges,  connected  to  the  corner  of  each  wing  by  a  handsome 
iron  balustrade.     They  are  joined  by  an  iron  gate. 

/  }^  yj^l  be  observed  that  the  back  loom-shed  has  only  one  story,  as  shown  in  section, 
W  ^91)-  In  the  ground-plan  of  the  shed,  n  represents  the  roofing,  of  wood-work. 
Ihe  rafters  of  the  floors  rest  at  their  ends  upon  an  iron  plate,  or  shoe  with  edges  (as  it 
18  called),  for  the  girders  to  bear  upon.  g     ^aa  n. 

The  two  steam  engines,  of  fully  90  horse  power  each,  operate  by  cranks,  which 
stand  at  right  angles  upon  the  shaft  marked  a  both  in  the  plan  and  section  In  the 
centre,  between  the  bearings,  is  a  large  cog-wheel,  driying  a  smaller  one  upon  the 
shaft  marked  6  in  both  figures,  to  which  the  fly-wheel  c  belongs.  That  prime  motion 
wheel  is  magnificent,  and  possesses  a  strength  equal  to  a  strain  of  300  horses.  From 
this  shaft  motion  IS  given  to  the  main  or  upright  shaft  d,  in  the  section,  by  two  bevel 
wheels  visible  at  the  side  and  on  the  top  of  the  great  block  of  stone,  about  6  tons 
weight  (Jig.  391),  which  gives  a  solid  basis  to  the  whole  moving  apparatus. 

Ihe  velocity  of  the  piston  in  these  steam  engines  is  240  ft  per  minute. 

ihe  trst  shaft  makes  44  3  revolutions  per  minute;  the  main  upright  shaft  68-84 
per  minute.  The  steam  engines  make  16  strokes  per  minute;  and  the  length  of  their 
stroKes  is  7  it  6  in. 

As  the  one  engine  exerts  its  maximum  force  when  the  other  has  no  force  at  all.  and 
as  the  one  increases  as  the  other  diminishes  in  the  course  of  each  pair  of  strokes,  the 
two  thus  cooperate  m  imparting  an  equable  impulsion  to  the  great  geering  and  shafts 
which,  being  truly  made  highly  polished,  and  placed  in  smooth  beafings  of  hard  brass 
revolve  most  silently  and  without  those  vibrations  which  so  regularly  recurred  in  the 
frame      "^^         ^^         ^  detrimental  to  the  accurate  performance  of  delicate  spinning 

To  the  horizontal  ramifications  from  the  upright  shaft  any  desired  velocity  of  rotation 
may  be  given  by  duly  proportioning  the  diameters  of  the  bevelled  wheels  of  communi- 
cation  between  them,-  thus,  if  the  wheel  on  the  end  of  the  horizontal  shaft  have  one 
half  or  one  third  the  diameter  of  the  other,  it  will  give  it  a  double  or  a  triple  speed. 

In  the  lowest  floor,  the  second  bevel  wheel  above  the  stone  block  drives  the  horizontal 
shaft  e,  seen  m  the  ground  plan  ;  and  thereby  the  horizontal  shaft  /,  at  right  angles  to 
the  former,  which  runs  throughout  the  length  of  the  building,  as  the  other  did  through 
Its  breadth,  backward.    The  shaft  /  lies  alongside  of  the  back  window  wall,  near  tJe 


I 


i 


COTTON  FACTORY. 


[503] 


ceiling ;  and  from  it  the  tranverse  slender  shafts  proceed  to  the  right  and  left  in  the 
main  buil<ling,  and  to  the  shed  behind  it,  each  of  them  serving  to  drive  two  lines  of 
looms.  These  slender  or  branch  shafts  are  mounted  with  pulleys,  each  of  which  drives 
four  looms  by  four  separate  bands. 

In  the  second  and  third  floors,  where  the  throstles  are  placed,  the  shaft  d  is  seen  in 
the  section  to  drive  the  following  shafts: — 

Upon  the  main  upright  shaft  d  {fig.  390),  there  are  in  each  of  these  stories  two 
horizontal  bevel  wheels,  with  their  faces  fronting  each  other  (shown  plainly  over  dd),  by 
which  are  moved  two  smaller  vertical  bevel  wheels,  on  whose  respective  axes  are  two 
parallel  shafts,  one  over  each  other,  g,  g,  which  traverse  the  whole  length  of  the  building. 
Tliese  two  shafts  move  therefore  with  equal  velocities,  and  in  opposite  directions.  They 
run  along  the  middle  space  of  each  apartment;  and  wherever  they  pass  the  rectangular 
line  of  two  throstle  frames  (as  shown  at  f  in  the  ground  plan)  they  are  each  provided  with 
a  pulley;  while  the  steam  pulleys  on  the  axes  of  two  contiguous  throstles  in  one  line 
are  placed  as  far  apart  as  the  two  diameters  of  the  said  shaft-pulleys.  An  endless  strap 
goes  from  the  pulley  of  the  uppermost  horizontal  shaft  g,  round  the  steam  or  driving- 
pulley  of  one  throstle  frame ;  then  up  over  the  pulley  of  the  second  or  lower  shaft,  g\ 
next  up  over  the  steam  pulley  of  a  second  throstle ;  and,  lastly,  up  to  the  pulley  of  the 
top  shaft  g.     See  ^g'va.  the  throstle  floors  of  the  cross  section. 

In  the  preparation  room,  three  horizontal  shafts  are  led  pretty  close  to  the  ceiling 
through  the  whole  length  of  the  building.  The  middle  one,  A  (see  the  plan  fig.  389^ 
IS  driven  immediately  by  bevel  wheels  from  the  main  upright  shaft  d  {fig.  390).  The 
two  sides  ones,  i,  i,  which  run  near  the  window  walls,  are  driven  by  two  horizontal  shafts, 
which  lead  to  these  side  shafts.  The  latter  are  mounted  with  pulleys,  in  correspondence 
with  the  steam  pulleys  of  two  lines  of  carding  engines,  as  seen  between  the  cards  in 
the  plan.  The  middle  shaft  A,  drives  the  two  lines  of  bobbin  and  fly  frames,  e,  e,  k,  b 
(see  cross  section),  and  short  shafts  i,  i,  seen  in  the  cross  section  of  this  floor,  moved 
from  the  middle  shaft  A,  turning  in  gallows  fixed  to  the  ceiling,  over  the  drawing 
and  jack  frames,  give  motion  to  the  latter  two  sets  of  machines.  See  c  d  in  the  cross 
section. 

To  drive  the  mules  in  the  uppermost  story,  a  horizontal  shaft  k  (see  longitudinal  and 
cross  sections,  as  well  as  ground  plan)  runs  through  the  middle  line  of  the  building, 
and  receives  motion  from  bevel  wheels  placed  on  the  main  upright  shaft  d,  immediately 
beneath  the  ceiling  of  the  uppermost  story.  From  that  horizontal  shaft  *,  at  every 
second  mule,  a  slender  upriglit  shaft  A  passing  through  both  stories,  is  driven  (see  both 
sections).  Upon  these  upright  branch  shafts  are  pulleys  in  each  story,  one  of  which 
serves  for  two  mules,  standing  back  to  back  against  each  other.  To  the  single  mules 
at  the  ends  of  the  rooms  the  motions  are  given  by  still  slenderer  upright  shafts,  which 
stand  upon  the  head  stocks,  and  drive  them  by  wheel-work,  the  steps  (top  bearings)  of 
the  shafts  being  fixed  to  brackets  in  the  ceiling. 

In  the  attic,  a  horizontal  shaft,  m  ?n,  runs  lengthwise  near  the  middle  of  the  roof,  and 
IS  driven  by  wheel  work  from  the  upright  shaft  This  shaft  in,  gives  motion  to  the 
warping  mills  and  dressing  machines. 

This  cotton  mill  having  been  erected  according  to  plans  devised  and  executed  by 
that  very  eminent  engineer,  Mr.  Fairbairn,  of  Manchester,  may  be  justly  reckoned  a 
model  of  factory  architecture.  It  is  mounted  with  1,100  power  looms,  of  which  100 
require  steam  power  equivalent  to  25  horses  to  impel  them,  inclusive  of  the  preparation 
and  spinning  operations  competent  to  supply  the  looms  with  yarn.  A  third  steam 
engine  is  added. 

Ten  looms,  with  the  requisite  dressing,  without  spinning,  are  considered  to  be  equi- 
valent to  1  horse  power  in  a  steam  engine.    Steam  power  equivalent  to  1  horse  will 


drive — 


600  mule  spindles, 
300  self-actor  spindles, 

180  throstle  spindles  of  the  common  construction;  in  which  estimate  the  requisite 
preparation  processes  are  included. 


In  Mr.  Orrell's  mill  there  are  6,474  spindles  in  each 
of  the  throstle-frame  floors      -  -  . 

And  14  pairs  of  mules  in  each  of  the  2  mule  floors, 
containing  altogether  ... 

19  self-actors  in  the  wing,  containing 


12,948    spindles 


24,928 
7,984 


« 
it 


Total  yarn  spindles    -    45,860 


m 


[504] 


COTTON  FACTORY. 


m 


One  of  the  most  compact  and  best-regulated  modern  factories,  on  the  small  scale 
"which  I  visited  in  Lancashire,  consisted  of  the  following  system  of  machines: ^ 

1  willow,  1  blowing  machine,  1  lap  machine,  capable,  together,  of  cleaning  and 
.        lapping  9,000  pounds  of  cotton  per  week,  if  required. 

21  cards,  breakers,  and  finishers,  which  carded  5,000  Iba.  of  cotton  every  week  of 

69  hours'  work,  being  about  240  lbs.  per  card. 
3  drawing-frames,  of  3  heads  each. 
3  coarse  bobbin  and  fly  frames. 
7  fine  da  No  stretcher  mule. 

12  self-actor  mules,  of  Sharp  and  Roberts's  construction,  of  404  spindles  each 

•=4,848  mule  spindles. 
10  throstle  frames,  of  236  spindles  each  —2,360  spindles. 
7  dressing  machines. 
236  power  looms. 

2  warping  mills. 

800  winding  spindles  for  winding  the  warp. 
The  rovings  have  4  hanks  in  the  pound,  and  are  spun  into  yarn  No.  38  on  the 
tiirostlc,  as  well  as  the  mule. 

One  bobbin  of  the  roving  (compressed)  lasts  5  days  on  the  self-actors,  and  6  days  on 
the  throstles.  -»  j 

According  to  the  estimate  of  Peile  <fe  Williams,  of  Manchester,  66  horses  power  of 
a  steam  engine  are  equivalent  to  396  power  looms,  including  16  dressing  machines; 
the  cloth  being  36  mehes  wide  upon  the  average,  and  the  yarn  varying  in  fineness  from 
12  8  to  40  s,  the  mean  being  26's.  Here,  the  spinning  and  preparation  not  being 
included,  the  allowance  of  power  will  appear  to  be  high.  The  estimate  given  above 
assigns  10  looms,  with  the  requisite  dressing,  to  1  horse ;  but  the  latter  assigns  no  more 
than  6. 

For  the  following  experimental  results,  carefully  made  with  an  improved  steam- 
engme  indicator,  upon  the  principle  of  Mr.  Watt's  construction,  1  am  indebted  to  Mr. 
Bennet,  an  eminent  engineer  in  Manchester.  His  mode  of  proceeding  was  to  deter- 
inine,  first  of  all,  the  power  exerted  by  the  factory  steam  engine  when  all  the  machines 
of  the  various  floors  were  in  action ;  then  to  detach,  or  throw  out  of  geer,  each  system 
of  machines,  and  to  note  the  diminution  of  force  now  exercised.  Finally,  when  all  the 
machines  were  disengaged,  he  determined  the  power  requisite  to  move  the  enWne  itself 
as  well  as  the  great  geering-wheels  and  shafts  of  the  factory.  °  ' 

He  found  at  the  factory  of  S.  A  Beaver,  Esq.,  in  Manchester,  that  500  calico  looms 
(without  dressing)  took  the  power  of  33  horses,  which  assigns  15  looms  to  1  horse 
power. 

At  Messrs.  Birlie's  factory,  in  Manchester,  he  found  that  1,080  spindles  in  3  self- 
afttor  mules  took  2.59  horses,  being  417  spindles  for  1  horse  power;  that  3,960  spindles 
m  11  self-actors  took  8.33  horses,  being  475  spindles  per  horse  power;  1080  spindles 
in  3  self-actors  took  2  horses,  being  540  spindles  per  horse. 

At  Messrs.  Clarke  &  Sons,  in  Manchester,  that  585  looms  for  weaving  fustians  of 
various  breadths  took  54  horses  power,  exclusive  of  dressing  machines,  being  11  looms 
to  1  horse. 

At  J.  A  Beaver's,  on  another  occasion,  he  found  that  1,200  spindles,  of  Danforth's 
construction,  took  21  horses,  being  67  spindles  per  horse  power;  and  that  in  a  second 
trial  the  power  of  22  horses  was  required  for  the  same  eflFect^  being  64  Danforth's 
spindles  per  horse  power. 

An  excellent  engine  of  Messrs.  Bolton  A  Watt,  being  tried  by  the  indicator,  aflForded 
the  following  results  in  a  factory : 

A  60  horse  boat-engine  (made  as  for  a  steam  boat)  took  14^  horses 

power  to  drive  the  engine  with  the  shafts  -  -  -  -  14-5 

3|  blowing  machines,  with  their  three  fans    ...  -  21'55 

10  dressing  machines  --.....  10'>5 

12  self-actor  mules,  of  360  spindles  each  (720  spindles  per  horse  power)  6-00 
6  Danforth  throstle  frames,  containing  570  spindles  (96  in  each),  being 

93  spindles  to  1  horse  power  -  -  .  .  _  6-20 

At  Boliington,  in  a  worsted  mill,  he  found  that  106|  spindles,  including  preparation 
took  1   horse  power  upon  throstles.     N.  B.  There  is  no  carding  in  the  long  wool  or 
worsted  manufacture  for  merinos: — 

At  Bradford,  in  Yorkshire,  he  found  that  a  40  horse  power  boat-engine,  of  Bolton 
&  Watts,  drove  698  calico  looms,  6  dressing  machines  (equivalent  to  dress  warp  for 
180  of  the  said  looms),  and  1  mechanic's  workshop,  which  took  2  horses  power.  Othei 
engineers  estimate  200  common  throstie  spindles,  by  themselves,  to  be  equivalent  to  the 
power  of  1  horse. 


COTTON  FACTORY. 


505 


f 


0'^ 


The  shafts  which  drive  the  cards  revolve  about  120  times  per  minute,  with  a  driving 
pulley  of  from  15  to  17  inches  in  (Jiameter. 

The  shafts  of  the  drawing,  and  the  bobbin  and  fly  frames,  revolve  from  160  to  200 
times  per  minute,  with  pulleys  from  18  to  24  inches  in  diameter. 

The  shafts  of  throstle  frames  in  general  turn  at  the  rate  of  from  220  to  240  times  per 
minute,  with  driving  pulleys  18  inches  in  diameter,  when  they  are  spinning  yarn 
of  from  No.  35  to  40.  The  shafts  of  mules  revolve  about  130  times  per  minute,  with 
pulleys  16  inches  in  diameter. 

^    The  shafts  of  power  looms  revolve  from  110  to  120  times  per  minute,  -with  pulleys  15 
inches  in  diameter. 

^   The  shafts  of  dressing  machines  revolve  60  times  per  minute,  with  pulleys  14  inches 
m  diameter.  ^  r       j 

Before  quitting  the  generalities  of  the  cotton  manufacture  I  way  state  the  following 
facts  communicated  also  by  Mr.  Bennet: — 

A  wagon-shaped  boiler,  well  set,  will  evaporate  12  cubic  ft  of  water  with  1  cwt  of 
coals;  and  a  steam  boiler  with  winding  flues  will  evaporate  17  cubic  ft  with  the  same 
weight  of  fuel :  7^2_  ibs.  of  coals  to  the  former  boiler  are  equivalent  to  1  horse  power 
exerted  for  an  hour,  estimating  that  a  horse  can  raise  33,000  lbs.  1  foot  high  in  a 
minute. 

The  first  cotton  mill  upon  the  fire-proof  plan  was  erected,  I  believe,  by  the  Messrs. 

?o'r!i^*^  .u^  ?^JPi?'''ri''  ^^^  y''^';  ^^J^ '  ***^*'  «^  ^«*^''«-  P^»"'PS  *  Lee,  at  Manchester,  in 
1801 ;  that  of  H.  Houldsworth,  Esq.,  of  Glasgow,  in  1802  ;  and  that  of  James  Kennedy, 
at  Manchester  in  1805;  since  which  time  all  good  factories  have  been  built  fire-proof 
hke  Mr.  Orrell  s.  *^        * 

The  heating  of  the  apartment  of  cotton  factories  is  eff'ected  by  a  due  distribution  of 
cast-iron  pipes,  of  about  7  or  8  inches  diameter,  which  are  usually  suspended  a  little 
way  below  the  ceilings,  traverse  the  rooms  in  their  whole  length,  and  are  filled  with 
steam  from  boilers  exterior  to  the  building.  It  has  been  ascertained  that  one  cubit 
foot  of  boiler  will  heat  fully  more  than  2,000  cubic  ft  of  space  in  a  cotton  mill,  and 
maintain  it  at  the  temperature  of  about  75^  Fahr.  If  we  reckon  25  cubit  ft  contents 
of  water  in  a  waggoned-shaped  steam  boiler  as  equivalent  to  1  horse  power,  such  a 
boiler  would  be  capabe  of  warming  50,000  cubic  ft  of  space;  and  therefore  a  10 
horse  steam  boiler  will  be  able  to  heat  500,000  cubic  ft  of  air  from  the  average 
temperature,  50°,  of  our  climate,  up  to  76°  or  perhaps  even  80°  Fahr. 

It  has  been  also  ascertained  that  in  a  well-built  cotton  mill,  one  superficial  foot  of 
exterior  surface  of  cast-iron  steam  pipe  will  warm  200  cubic  ft  of  air.  In  common  cases 
for  heating  churches  and  public  rooms,  I  believe  that  one  half  of  the  above  heating  sur- 
face will  be  found  adequate  to  produce  a  sufficiently  genial  temperature  in  the  air.  The 
temperature  of  the  steam  is  supposed  to  be  the  same  with  that  in  Mr  Watt's  low- 
pressure  engines,  only  a  few  degrees  above  212^^— the  boiling  point  of  water 

The  pipes  must  be  freely  slung,  and  left  at  liberty  to  expand  and  contract  under 
the  changes  of  temperature,  having  one  end  at  least  connected  with  a  flexible  pipe  of 
copper  or  wrought  iron,  of  a  swan-neck  shape.  Through  this  pipe  the  water  of 
condensation  is  allowed  to  run  off:  The  pipes  should  not  be  laid  in  a  horizontal 
direction,  but  have  a  sufficient  slope  to  discharge  the  water,  llie  pipes  are  cast  from 
half  an  inch  to  three  quarters  thick  in  the  metal.  In  practice  the  expansion  of  steam 
pipes  of  cast-iron  may  be  taken  at  about  one  tenth  of  an  inch  in  a  length  of  10  feet, 
when  they  are  heated  from  a  little  above  the  freezing  to  the  boiling  point  of  water 
The  upper  surface  of  a  horizontal  steam  pipe  is  apt  to  become  hotter  than  the  bottom, 
if  the  water  be  allowed  to  stagnate  in  it;  the  difterence  being  occasionally  so  great  as 
to  cause  a  pipe  60  feet  long  to  be  bent  up  2  inches  in  the  middle. 

In  arranging  the  steam  pipes  provision  ought  to  be  made  not  only  for  the  discharge 
of  the  water  of  condensation,  as  above  stated,  but  for  the  ready  escape  of  the  air  •  other- 
wise the  steam  will  not  enter  freely.  Even  after  the  pipes  are  filled  with  steam,' a  litUe 
of  It  should  be  allowed  to  escape  at  some  extreme  orifice,  to  prevent  the  re-accnmulation 
of  air  discharged  from  the  water  of  the  steam  boiler.  In  consequence  of  water  being 
left  in  the  pipes  serious  accidents  may  happen;  for  the  next  time  the  steam  is  admitted 
into  them,  the  regu  arity  of  heating  and  expansion  is  impeded,  some  part  of  the  pipe 
may  crack  or  a  violent  explosion  may  take  place,  and  the  joints  may  be  racked  to  • 
very  considerable  distance,  every  way,  from  the  place  of  rupture,  by  the  alternate 
expansions  and  condensations.  The  pipes  should  therefore  be  laid,  so  as  to  have  the 
least  possible  declivity,  in  the  direction  of  the  motion  of  the  steam. 

Formerly,  when  drying  rooms  in  calico  printing  works  were  heated  by  iron  stoves  or 
cockles,  their  inmates  were  very  unhealthy,  and  became  emaciated ;  since  they  hive 
been  heated  by  steam  pipes  the  health  of  the  people  has  become  remarkably  good,  and 
their  appearance  frequently  blooming. 

COTlbN    MANUFACTURE.      {Filature    de    Coton,    Fr.;     JBaumu>ollenspinnerte, 


506 


COTTON  MANUFACTURE. 


Gem.)    Colton  is  a  filamentous  down,  which  invests  t5ic  seeds  of  the  plant  called  iw. 
i^Mim  by  Linnaeus,  and  placed  by  him  in  the  class  monadelphia,  and  order  monandHa 
Dut  belongmg  to  the  natural  family  of  malvacea:.    It  has  a  cup-shaped  calyx  obtusely 
five-toolhed,  enclosed  in  a  three-clefl  exterior  calyx  ;  the  leaflets  are  united  at  their  base 
of  a  heart  shape,  ind  toothed;  stigmas  three  to  five;  capsule  three  to  five  celled  and 
many  seeded ;  seeds  bearing  a  downy  wool.      Thirteen  species  are  described  by  Decan- 
dolle,  but  their  characters  are  very  uncertain,  and  no  botanist  can  assign  to  a  definite 
species  of  the  plant,  the  very  dissimilar  staples  of  the  cotton  filaments  found  in  commerce 
The  leaves  are  generally  palmate  and  hairy;  and  the  blossoms  are  large,  and  of  a  beau- 
tiful yellow.     The  gossypium  religiosum  of  Tranqnebar  has  while  blossoms  in  some  of 
Its  varieties,  to  which  probably  the  white  colton  of  Rome,  cultivated  in  the  Jardin  des 
Plantes  at  Pans,  belongs.     The  filaments  differ  in  length,  flexibility,  tenacity,  and  thick 
ness,  in  difl^erent  cottons,  whence  the  great  diflferences  of  their  value  to  the  cotton-spin- 
f "'  fSox  ^  P"7f.  *=""^"t  '"  t^e  market  show.     Thus,  at  Liverpool,  on  the  1st  of  Decem- 
fcer,  ISd5,  the  following  values  were  assigned  to  the  following  cottons  :— 


COTTON  MANUFACTURE. 


507 


Sea-island 

Demarara  and  Berbice 

Pernanibuco 

Egyptian 

New  Orleans 

Bahia 

Upland  Georgia 

West  Indian 

Surat 

Madras 

Beneal 


8.    d. 
1     6   to 
0    9 
0  lOf 
0  111 

8i 


0 
0 
0 
0 
0 
0 
0 


d. 

6 
0 

ll 

2| 
0 


7| 
7| 

6| 


0  10 
0  111 
9 
8 

8 

eh 


0 
0 
0 
0 


But  It  IS  to  be  observed,  that  there  are  varieties  of  the  Sea-island  Georgian  cotton,  so 

T?K    IV        ^^  ^^/  spinner  of  fine  yam,  as  to  fetch  3^.,  4*.,  or  even  5*.  per  pound. 

ine  niaments  of  cotton,  when  examined  with  a  good  microscope,  are  seen  to  be  more 

or  less  nband-iike,  and  twisted ;  having  a  breadth  varying  from  _L_  of  an  inch  in  the 

strongest  Smyrna  or  candle-wick  cotton  of  the  Levant,  to  ,  »_  of  ^  inch  in  the  finest 

Sea-island.  *^*"" 

«rrIn\^.^'"i'^'f'"fK'°r  ^^^'^^^''  *'*'"°"'  '"  *^^  ^^  '^  *^^*  «^  ^he  black  seeded  and  the 
f^uVL  7\  ^he  former  part  with  their  downy  wool  very  readily  to  a  pair  of  simple 
latPr;.?«^  ti*"  ^^^°^e  nearly  in  contact,  by  the  power  of  the  human  am;  while  the 
lal  pS  hi  ^  T^^  ""'^^  ?°"*'^-  ^^'i*^^'  ^"^  '•^"^^^  *«  ^«  ?i"n«J»  as  the  operation  is 
^Pr  ^5^.V°T  ir  '''-,  '^.^••^"^^'-  saw-mechanism,  usually  driven  by  horse  or  water 
^7vL  tl^'  T  ^'?^^  v!'  ^^"'  separated  from  the  seeds,  it  is  packed  in  large 

S?P  for  tif^  '  ^^^^^^^y  ^th  the  aid  of  a  screw  or  hydraulic  press,  into  a  very  denle 
1^  of  .nrt^  *^^"^^°'^!S!  of  transport.  Each  of  the  American  bags  contains  about  34o 
flockv  thlt  h  ;    f  ^'"  this  cotton  is  delivered  to  the  manufacturer,  it  is  so  foul  and 

S  ^  tL  .  ^  """'^  ''^r''''  ^"'^  disentangle  it  with  the  utmost  care  before  he  can  subject 
M  10  Ine  carding  operation.  •' 

Fig.  390,  A  B,  is  a  roller,  about  9  inches  in  diameter, 
which  revolves  in  the  direction  of  the  arrow.  This 
cylinder  consists  of  a  parallel  series  of  oblique  pointed 
circular  saws  made  fast  to  one  axis,  and  parted  from 
J  each  other  by  wooden  rings  nearly  one  inch  and  a  half 
m  thickness.  Above  the  cylinder,  is  a  kind  of  hopper 
IK  E  F,  into  which  the  ginner  throws  the  seed  cotton,  which 

«r  ♦».«  o«^  ♦    ♦I.       .    .  ?"^  ^P®"  *  grating,  up  through  which  small  segments 

of  the  saw-teeth  project  so  as  to  lay  hold  of  the  fibres  in  their  revolution,  and  pull  them 
through,  while  the  seeds,  being  thus  separated,  roll  down  the  slope  of  the  grid,  to  be 
discharged  from  the  spout  i  k.  m  is  a  cylindrical  brush  placed  below  the  gmting, 
which  revolves  against  the  saw-teeth,  so  as  to  clear  them  of  the  adhering  cotton 
niaments.  ° 

The  willow,  which  was  originally  a  cylindrical  willow  basket,  whence  its  name,  but  is 
BOW  a  box  made  of  wood  with  revolving  iron  spikes,  is  the  first  apparatus  to  which 
cotton  wool  IS  exposed,  after  it  has  been  opened  up,  pickfti,  and  sorted  by  hand  or  a 
rake,  m  what  is  called  a  bing.  The  willow  exercises  a  winnowing  action,  loosens  the 
large  flocks,  and  shakes  out  much  of  the  dirt  co„tained  in  them.  The  frame  of  the 
willow  IS  about  2  feet  wide,  and  turns  with  its  spikes  at  the  rapid  rate  of  600  revolutions 
per  minute,  whereby  it  tosses  the  cotton  about  with  great  violence.  The  heavy  im- 
purities  fall  down  through  the  grid  bottom.  It  is  exposed,  however,  for  only  a  few 
minutes  to  the  action  of  this  machine.  For  factories,  which  work  up  chiefly  the  coarser 
ind  fouler  cottons  of  India,  and  Upland  Georgia,  the  conical  self-acting  willow   ea 


391 


constructed  by  Mr.  Lillie  at  Manchester,  is  much  employed.  In  it,  the  cotton  is  put  in  at 
the  narrow  end  of  the  truncated  cone,  which,  being  spiked,  and  revolving  rapidly  within 
a  nearly  concentric  case  upon  a  horizontal  axis,  wafts  it  on  towards  the  wide  end,  while 
its  impurities  are  partly  shaken  out  through  the  grid  or  perforated  bottom,  and  partly 
sucked  up  through  revolving  squirrel  wire  cages,  by  the  centrifugal  action  of  a  fan.  This 
is  a  powerful  automatic  engine,  deserving  the  study  of  the  curious,  and  is  as  safe  as  it  is 
powerful.  The  cone  of  this  huge  machine  makes  from  400  to  600  turns  per  minute,  and 
wiU  clean  7200  pounds,  or  24  bags,  in  a  day. 

After  shaking  out  the  grosser  impurities  by  the  willow,  the  cotton  spinner  proceeds 
to  separate  each  individual  filament  of  cotton  wool  from  its  fellow,  so  as  to  prepare  it 
for  carding,  and  to  free  it  from  every  particle  of  foreign  matter,  whether  lighter  or 
heavier  than  itself.  This  second  operation  is  performed  by  what  are  called  batting 
{beating),  scutching,  and  blowing  machines,  which  are  all  now  much  the  same,  what- 
ever difference  of  signification  the  name  may  have.    Indeed,  each  machine  not  only 

beats,  scutches,  bU  blows.  Fig.  391  ex- 
hibits a  longitudinal  section  of  a  good 
blowing  engine  of  modern  construction. 
The  machine  is  about  18  or  19  feet  long, 
and  three  feet  across  within  the  case.  The 
whole  frame  is  made  of  cast-iron,  lined 
with  boards,  forming  a  close  box,  which  has 
merely  openings  for  introducing  the  raw 
cotton  wool,  for  taking  out  the  cleansed 
wool,  and  removing  the  dust  as  it  collects 
at  the  bottom.  These  doors  are  shut  du- 
ring the  operation  of  the  machine,  but  may 
be  opened  at  pleasure,  to  allow  the  interior 
to  be  inspected  and  repaired. 

The  introduction  of  the  cotton  is  effected 
by  means  of  an  endless  cloth  or  double 
apron,  which  moves  in  the  direction  of 
the  arrow  a  a,  at  the  left  end  of  the  figure, 
by  passing  round  the  continually  revolving 
rollers  at  b  and  c.    The  two  rollers  at  «, 
being  the  ones  which  immediately  intro- 
duce the  cotton  into  the  jaws,  as  it  were, 
of  the  machine,  are  called  the  feed  rollers. 
The  batting  arm,  or  revolving  diameter, 
/«,  turns  in  the  direction  of  the  arrow,  and 
strikes  the  flocks  violently  as  they  enter,  so 
as  to  throw  down  any  heavy  particles  upon 
the  iron  grating  or  grid  at  n,  while  the 
light  cotton  filaments  are  wafted  onwards 
with  the  wind,  from  the  rotation  of  the 
scutcher  in  the  direction  of  arrow  a\  along 
the  second  travelling  apron,  upon  which  the 
squirrel  cage  cylinder  presses,  and  applies 
the  cotton  in  the  form  of  a  lap.     Above  the 
cylindric  cage  h,  which  turns  in  the  di- 
rection of  its  arrow,  there  is  a  pipe  fe,  the 
continuation   of  the  case   t.     This   pipe. 
though  broken   off"  in   the   figure,   com- 
municates by  a  branch  pipe  with  an  air- 
sucking  fan  ventilator,  not  seen   in  this 
figure,  but  explained  under  Foundry.  The 
cage  A,  by  its  rotation,  presses  down,  as  we 
have  said,  the  half  cleaned  cotton  upon  the 
cloth  a',  which  carries  it  forward  to  the 
second  scutcher  /',  by  the  second  set  of 
feed  rollers  e'.    The  second  scutcher  throws 
down  the  heavy  dust  upon   the  second 
grid  n',  through  which  it  falls  upon  the 
bottom  of  the  case.     The  first   scutcher 
makes  about  1280  strokes  of  each  of  its 
two  arms  in  a  minute ;  the  second  1300. 
The  fbed  rollers  for  each  are  fluted.    The  feed  cloth  is  either  sustained  by  a  board,  or 
is  made  of  parallel  spars  of  wood,  to  secure  it  against  bagging,  which  would  render  th« 


508 


COTTON  MANUFACTURE. 


P 


i 


I 


392 


delivery  of  the  cotton  irregular.  The  feed  rollers  mal<e  8  turns  in  iht.  «,;«„»-  j 
their  diameter  is  1|  inches,  they  will  introduce  8  times  the^  cr„mference  rs^^  inle! 
of  the  cotton  spread  upon  the  apron  in  that  lime.  Upon  every  12th  part  of  an  nrh  «? 
the  cotton,  therefore,  nearly  3  blows  of  the  scutcher  irm  wiAe  app^fel  '^xL^^^oSd 
feed  rollers  move  relatively  with  more  slowness,  so  fhat  for  every  2-4  blows  of  th« 
scutcher,  only  one  twelfth  of  an  inch  of  cotton  wool  is  presented 

The  fan  is  enclosed  in  a  cylindrical  case.  The  wings  or  vanes  revolve  from  120  to 
150  times  m  the  minute ;  and  while  they  throw  the  air  out  with  nearly  this  veSci  ? 
at  their  iccentric  outle^  m  the  circumference,  they  cause  it  to  enter,  with  eqral  ve^ 
locity,  at  the  centre.    With  this  centre  the  squirrel  cage  is  connected  by  a  pipe,T  above 

stated.  The  sound  filaments  of 
the  cotton  are  arrested  by  the 
sieve  surface  of  the  cylindric  cage, 
and  nothing  but  the  broken  frag- 
ments and  the  light  dust  can  pass 
through. 

The  cotton  wool  in  the  blowing 
machine  is  wafted  by  the  second 
scutcher  into  the  space  x,  w,  w, 
provided  with  a  fine  grid  bottom ; 
or  it  is  sometimes  wound  up  there 
by  rollers  into  a  lap. 

In  fig.  391   an  additional  venti- 
lator is  introduced  beneath  at  wi, 
0,   o,   to   aid   the   action   of  the 
scutchers  in  blowing  the  cotton 
onwards  into   the  oblong  trough 
o.    The  outlet  of  that  fan  is  at 
/;  and  it  draws  in  the  air  at  its 
axis  q.    n  and  v  are  two  doors 
or  lids  for  removing  the  cleaned 
cotton  wool.     This  last    fan   is 
suppressed  in  many  blowing  ma- 
chines,   as    the    scutching    arms 
supply  a  suflicient  stream  of  air. 
The  dotted  lines  show  how  the 
motion   is   transmitted   from   the 
first  mover  at  *,  to  the  various 
parts  of  the  machine.    6'  6'  rep- 
resent the  bands  leading  to  the 
main    shafting   of   the   mill.      A 
machine  of  this  kind  can  clean 
fully  600  pounds  of  short-stapled 
cotton  wool  in  a  day,  with  the 
superintendence  of  one  operative, 
usually  a 
tribute  the 
feed  cloth. 

The  second   Blowing  machine 
is  usually  called  a  lap  machine, 
because,  after  blowing  and  scutch- 
ing the  cotton,  as  above  described, 
it  eventually  coils  the  fleece  upon 
a  wooden  roller  at  the  delivering 
end  of  the  apparatus.     It  is  some- 
times,  also,   called    a    spreading 
machine.      A    section    of    it    is 
shown  in  fig.  392.    The  breadth 
of  this  machine  is  about  3  feet,  as 
the   lap  formed    is   prepared   for 
the  usual  breadth  of  the  breaker 
cards,  namely,  3  feet.     Where  the 
cards  are  only  18  inches  broad, 
the  lap  machine  is  also  made  of 
see  the   feed-cloth,  the   scutching  barrel,   the 
and  the   rollers   for  coiling  up  the  lap.     The 
the   pressure  weight  from    the  axis  of  the  lap 


young 


"  woman,  to  dis- 
cotton  upon  the  first 


tlie  same  breadth.    In  the   fig^ire 
squirrel  suction,  and    spreading 
lever  shown   below  is  for 


we 
cage, 


removing 


^f 


COTTON  MANUFACTURE.  509 

rollers,  when  a  fuU  one  is  to  be  removed,  and  replaced  by  an  empty  one.  m,  at  the  top, 
fJl  *^°°^°?^"'^^«>ent  of  the  pipe  which  leads  to  the  suction  fan,  or  ventilator.  The 
tn.ckness  of  the  lap  i„  this  machine  must  be  nicely  regulated,  as  it  determine;  in  a 
great  measure,  the  grist  of  the  card-ends,  and  even  the  rovings.  '  In  12  hours  such  a  ^aj 
machine  will  prepare  650  pounds  of  cotton.  ^ 

A  B  if  fhfrJ.V!lf  fh"'  scutching  machine,  now  never  seen  except  in  the  oldest  factories. 
A  B  is  the  feed  cloth ;  g  h  and  m  n  are  the  two  scutcher  frames. 


..^mm^ 


393 


^^^z  %i::.ZsTo'^tJ:,,t:^^^^^^^  th'emV^^*^-'^  ^^frt;!^ 

doubled   up   and   convoluted,   as   thev   usuallv    «r7  •  ^  lengthwise,  instead  of  being 
machines.     Carding  consist  in  the  r^ntnTl Jt-rl''    leaving  the  blowing  and  lap 

^^^  395 


a  MM        > 

f,  -- — m    — • 

n   »»- 


a  flock  or  tuft  of  cotton  placed  between  tL.^,pi!Tfr'  Parallel.    Now  suppose 

in  the  direction  of  its  arrowrand  let  fbe  moved  t  th?  "^  r^?""'-  •  ^"*  **  ^  "°^^^ 
remain  at  rest.     Every  filam'ent  of  the  cotrn  wil   be  ^^0^^  b^^  T  T?}""'  t' 

When  their  surfaces  are  thus  drawn  over  each  other  thP  wh  r  ^  -.f  ^  u^^  ?^  ^^f^^' 
forward  direction,  while  those  ofT will  tpn^f..^'  ^^^  ^eeth  of  a  will  pull  them  in  a 
The  loops  or  doublings  wm  by  bot^mo^^^^^^  them,  or  to  pull  them  backwanls. 

flocks  will  be  converged  jLLws  of ^arX^fi?  ^^  TT^  ^'  ^'^^"  °"^'  ^°  ^^^^  ^he 
other.    Each  tooth  w  11  secure  to  iNelf ^Z        ^l^^^^^ts,  lying  alongside  or  before  each 

Let  us  suppose  this  end  eflTected,  and  that  all  the  fihrpe  >,«^«  v        ,        r       ^         , 
card  a,  a  transverse  stroke  of  6  will  draw  over  to  it  ^oLt  •       ^T  transferred  to  the 
deed  at  each  stroke  there  will  be  a  new  n^rth^on  hit       ll\  ""°'^''  ""^  ^^""^'  "^  '»- 
parallelism,  but  still  each  card  wilfrltaTa  greaf  deaTof  thr  T"^''  V""  ^"?^^^"^ 
rwnt«5-'  '''  '-''  ''  -  ^^  ^^-  "-  X^lTr-.r^^:- 

combVut  aTor'ZoT^^'hrfireill^^^^^^^  ^'^  ^^"  ^"^^^^"^ 

eition,  no  power  of  retaining  them  Even  t?e  douWed  Ty.r.T^V^  *  ^T', '"  '^''  ^ 
slopini?  point  of  6,  in  obedience  to  the  traction  of?  If  oops  will  slip  over  the 
positions  of  the  cards,  which  take  placl  In  hand  eaVd.  ^  '^^'k'""^  '^^'^  '^*^  7^"'^^^ 
any  person  will  be  able  to  understand  the  nl^vn^o^rT^^^  ^l  reversing  one  of  them 
against  another  cylinder  car^re  respective  tplthK  ^y^'"}^^' ^^^d  against  its  flat  top,  or 
position  of /?g.  394;  and  also  the  pC^^^^^ 
in  What  maV  be  called  the  stripp^n^Stt^nV^g^^^^^^^^^^     ^^^^^"^'  '""^ '^^'^  ^^^^^-^ 

we^ete^ngrntsTnv^rr^fllv'i  Z^%:^j^^t  f ''''''''  'T'^  ^^^^' 
«d  brought  into  nearly  their  present "o^lt^sunr^^^ 


510 


COTTON  MAMJFACTURE. 


COTTON  MANUFACTURE. 


511 


» 1 

V- 


Wi 


carding  engine  consists  of  one  or  more  cylinders,  covered  with  card-leather  (somelimcf 
called  card  cloth),  and  a  set  of  plane  surfaces  similarly  covered,  made  to  work  against 
each  other  but  so  that  their  points  do  not  come  into  absolute  contact.  Some  cards 
consist  entirely  of  cylinders,  the  central  main  cylinder  being  surrounded  by  a  series  of 
smaller  ones  called  urchins  or  squirrels.  These  are  used  solely  for  preparing  the  coarser 
stapled  cotton,  and  sheep's  wool  for  the  wool  spinner.  „.     ,      , 

Fig.  396  represents  a   card  of  excellent  construction,  which  may  be  called  a  breakef 
and  finisher,  as  it  is  capable  of  working  up  the  fleece  roll  of  the  lapping  machine  di 
rectly  into  a  card-end  or  riband  fit  for   the  drawing  machine.     In  fine  spinning  mills 
there  are  always,  however,  two  cards ;  one  coarser,  called  a  breaker,  which  turns  off 


the  cotton  in  a  broad  fleece  of  extreme  thinness,  which  is  lapped  round  a  cylinder  j 
and  constitutes  the  material  presented  to  the  finisher  card,  which  has  teeth  of  a  finci 
construction. 

a  is  one  of  the  two  upright  slots,  which  are  fixed  at  each  side  of  the  engine  for  re- 
ceiving the  iron  gudgeons  of  the  wooden  cylinders  round  which  the  fleece  of  the  lapping 
machine  is  rolled.  The  circumference  of  this  coil  rests  upon  a  roller  6,  which  is  made  10 
turn  slowly  in  such  a  direction  as  to  aid  the  unfolding  of  the  lap  by  the  fluted  cylinders 
e.  The  lap  proceeds  along  the  table  seen  beneath  the  letter  c,  in  its  progress  to  the  fluted 
rollers,  which  are  an  inch  and  one  sixth  in  diameter,  and  have  28  fluiings  in  their  cir- 
cumference, g  is  a  weight  which  hangs  upon  the  axis  of  the  upper  roller,  and  causes 
it  to  press  upon  the  under  one :  /  is  the  main  card  drum ;  g  g  g)  the  arch  formed  by 
the  flat  top  cards;  h,  the  small  card  cylinder  for  stripping  off  the  cotton,  and  therefore 
called  the  doffer,  as  we  have  said ;  i,  the  doffer-knife  or  comb  for  stripping  the  fleecy 
web  from  the  doffer ;  klqm,  Ihe  lever  mechanism  for  iBoving  these  parts.  At  d  there  is 
a  door  for  permitting  the  tenter  to  have  access  to  the  interior  of  the  engine,  and  to  re- 
move whatever  dirt,  &c.  may  happen  to  fall  into  it.  In  fig.  397  we  see  the  manner  of  fix- 
ing the  flat  tops  g  g  over  the  drum ;  and  for  making  the  matter  clearer,  three  of  the  tops 
are  removed.  Upon  the  arched  cast-iron  side  of  the  frame,  a  row  of  strong  iron  pins  k 
are  made  fast  in  the  middle  line ;  and  each  top  piece  hiife,  at  each  of  its  ends,  a  hole, 
which  fits  down  upon  two  such  opposite  pins.  /  I  are  screws  whose  heads  serve  as 
supports  to  the  tops,  by  coming  into  contact  with  the  bottom  of  the  holes,  which  are  not 
of  course  bored  through  the  wood  of  the  tops.  By  turning  the  heads  of  these  screws  a 
little  the  one  way  or  the  other,  the  pins  may  be  lengthened  or  shortened  in  any  degree, 
so  as  to  set  the  tops  very  truly  in  adjustment  with  the  drum  teeth  revolving  beneath 
them,  h'  is  the  small  runner  or  urchin,  and  t'  the  large  runner ;  both  of  which  are 
spirally  covered  from  end  to  end  with  narrow  card  fillets  in  the  same  manner  as  the 
doffer.  The  main  drum  is  on  the  contrary  covered  with  card  cloth,  in  strips  laid  on 
parallel  to  its  axis,  with  interjacent  parallel  smooth  leather  borders.  The  teeth  of  these 
several  cards  are  set  as  represented  in  the  figure,  and  their  cylinders  revolve  as  the  arrows 
indicate.  The  runners  as  well  as  the  doffer  cylinder  may  be  set  nearer  to  or  farther 
from  the  drum  /;  but  the  screws  intended  for  this  adjustment  are  omitted  in  the  draw- 
ings, to  avoid  confusion  of  the  lines. 

The  card-end  or  fleece  taken  off  the  doffer  h  by  the  crank  and  comb  mechanism  «  k  m, 
passes  through  the  tin  plate  or  brass  funnel  riyfig.  396,  whereby  it  is  hemmed  in  and 
contracted  into  a  riband,  which  is  then  passed  through  between  a  pair  of  drawing  roll- 
ers 0.  It  is  next  received  by  the  rollers  u  v,  which  carry  it  off  with  equable  velocity, 
and  let  it  fall  into  the  tin  cans  placed  below,  or  conduct  it  over  a  friction  pulley,  to  be 
wound  along  with  many  other  card-ends  upon  a  lap  roller  or  large  bobbin.  The  latter 
nechanism  is  not  shown  in  this  figure.    A  sloping  curved  tin  or  brass  plate^  channelled  or 


ridged  along  its  surface,  conducts  the  card  ribands  separately ;  there  are  two  smooth 
iron  rollers  for  condensing  the  several  ribands,  and  a  wooden  pin  round  which  the  ribands 
.ire  lapped,  resting  between  two  leather-covered  rollers,  one  of  which  receives  motion 


from  mill  gearing,  and  imparls  it  by  friction  to  the  lap  roller  over  it.  The  iron  ends  of 
the  lap  roller  lie  in  upright  slots,  which  allow  them  freedom  to  rise  as  the  roller  gets 
filled  with  fleece. 

The  two  pairs  of  rollers  at  o  effect  the  extension  of  the  card-end,  and  reduce  its  size. 
The  under  rollers  are  made  of  iron  and  fluted ;  the  upper  ones  are  also  made  of  iron, 
but  they  are  covered  with  a  coat  of  leather,  nicely  glued  on  over  a  coat  of  flannel,  which 
two  coats  render  them  both  smooth  and  elastic.  Two  weights,  w,  press  the  upper  cylin- 
ders steadily  down  upon  the  under  ones.  Between  the  first  and  second  pair  there  is  a 
certain  interval,  which  should  be  proportioned  to  the  length  of  the  cotton  staple.  The 
second,  or  that  furthest  from  the  funnel,  revolves  with  greater  velocity  than  the  first,  and 
therefore  turns  out  a  greater  length  of  riband  than  it  receives  from  its  fellow ;  the  con- 
sequence is  a  corresponding  extension  of  the  riband  in  the  interval  between  the  two  pairs 
of  rollers. 

The  motions  of  the  several  parts  of  the  engine  are  effected  in  the  following  way.  The 
band,  p  p,  fig.  397,  which  comes  down  from  the  pulley  upon  the  main  shaft  near  the  ceiling 
of  the  work-room,  drives,  by  means  of  the  pulley  q,  the  drum/,^g.  396,  with  a  velocity 
of  from  130  to  140  revolutions  in  a  minute.  From  another  pulley  r,  on  the  axis  of  the 
drum,  the  axis  of  t  is  driven  by  the  band  s  working  round  the  pulley  /  on  its  end.  This 
shaft  drives  the  crank  and  lever  mechanism  of  the  stripper  knife  i.  A  third  pulley  of  the 
same  size  as  r  is  fixed  just  within  the  frame  to  the  other  end  of  the  drum,  and  from  it  a 
crossed  or  close  band  r'  goes  to  a  pulley  upon  the  small  runner  h',  to  give  this  its  rapid 
rotation.  Upon  the  opposite  end  of  the  engine  in  fig.  396,  these  wheels  and  pulleys 
are  marked  with  dotted  lines.  Here  we  may  observe,  first,  a  pulley  y  upon  the  drum,  and 
a  pulley  a',  which  receives  motion  from  it  by  means  of  the  band «.  The  axis  of  a' 
carries  in  front  a  pinion  m',  which  sets  in  motion  the  wheel  n'.  The  latter  imparts  mo- 
tion, by  means  of  a  pinion  and  intermediate  wheel  o',  to  the  wheel  h  on  the  doffer 
cylinder,  and  consequently  to  that  cylinder  on  the  one  hand ;  and  it  turns,  by  the  carrier 
wheel  p\  a  wheel  x,  whose  axis  is  marked  also  with  x  in  fig.  396,  upon  the  other 
hand.  The  axis  of  x',  fig.  396,  carries,  towards  the  middle  of  the  engine,  a  very  broad 
wheel,  which  is  represented  by  a  small  dotted  circle.  The  toothed  wheel  v  of  the  smooth 
'•oiler  v\fig.  396,  and  the  two  toothed  wheels  o  o,  fig,  396,  of  the  under  rollers  o  o,  fig, 
396,  work  into  that  broad  wheel.  The  wheel  of  the  second  or  delivery  fluted  roller  is 
seen  to  be  smaller  than  that  of  the  first,  by  which  means  the  difference  of  their  velocities 
IS  obtained.  The  large  runner  t  is  driven  from  the  main  drum  pulley,  by  means  of  the 
band  s',  and  the  pulley  m',  fig.  396.  The  said  band  is  crossed  twice,  and  is  kept  in  ten- 
sion by  the  pulley  f,  round  which  it  passes.  The  motion  of  the  fluted  rollers  e,  which 
feed  in  the  cotton  fleece,  is  effected  by  means  of  a  bevel  wheel  b'  on  the  end  of  the  doffer, 
which  works  into  a  similar  wheel  c'  on  the  oblique  axis  d'  (dotted  lines  across  the  drum), 
of  the  pinion  e'  upon  the  lower  end  of  the  same  axis  which  turns  the  wheel/*,  upon  the 
under  feed  roller. 

Each  of  the  feed  rollers,  ^g.  397,  bears  a  pinion  «  e  at  one  end,  so  that  the  upper  roUex 
turns  round  with  the  under  one.    The  roller  b,fig.  396,  is  set  in  motion  by  means  of 

33 


1  i 
s  ! 


512 


COTTON  MANUFACTURE. 


its  wheel  a:';  which  is  driven  by  a  wheel  r'  on  the  other  end  of  the  under  feed  roncr, 
through  the  intervention  of  the  large  carrier  wheel  w'.  The  original  or  fir.t  motion  of 
6  must  be  as  quick  as  that  of  the  fluted  feed  rollers  «,  m  order  that  the  former  may  uncoil 
as  much  lap  as  the  latter  can  pass  on.  ' 

The  annexed  table  exhibits  the  proper  velocities  of  the  different  cylinders  and  rollers 
of  the  carding  engine,  which,  however,  are  not  invariable,  but  may  be  modified  according 
to  circumstances,  by  changing  the  pinions  e',/tg.  396,  and  w',  according  to  the  quality  or 
length  oi  the  coiton  staple.  Ihe  velocities  stated  in  the  table  will  be  obtained  when  the 
pulley  a ,  Jig,  396,  is  made  greater  than  y  in  the  proportion  of  3  to  2,  and  the  wheels 
and  pinions  have  the  following  number  of  teeth  :  m',  18;  «',  50;  its  pinion,  18;  A,  128: 

^\f^ '  J?^  *l'°**^  7^.^^^  "P*'''  ^^^  ^^*^^  *^^  ^'  37  teeth  ;  the  wheel  o  of  the  first  fluted 
roller,  3o;  that  of  the  second,  21 ;  r,  44  ;  6'  and  e',  54  ;  €',  10 ;  f,  63 


Names  of  the  parts. 


Drum  /  - 

DofferA 

Runner  or  urchin  i'  - 

Ditto  A'        -        -        - 

Fluted  feed  roller  e  - 

First  drawing  roller  o    - 

Second  ditto 

Smooth  delivery  roller  v 


Diameter  in 
inches. 


35 
14 
•25 
■5 
•167 


167 


2-5 


Circumference 
in  inches. 


109-9 
43-96 
19-62 
11- 
3-664 
3-14 
3-664 
7-85 


Revolationain 
one  minute. 


130 
4-38 
5- 
470- 
0-696 
68-71 
114-52 
54-66 


Velocity. 


142-87 
192-5 
98-1 
5170- 

2-55 
215-75 
419-6 
429-08 


The  operauon  of  the  runners,  h'  and  i',  becomes  very  plain  on  comparing  their  ^peed 
with  one  another  and  with  that  of  the  main-drum,  and  taking  into  account  the  direction 
of  the  card  teeth.  The  cotton  wool,  taken  off  from  the  feed-rollers  by  the  drum  is 
caught  by  the  opposite  teeth  of  the  large  runner  i',  which,  on  account  of  its  slower  sir- 
face  rotation  (98  inches  per  minute),  may  be  considered  to  be  at  rest  with  reference  to  the 
drum,  and  therefore,  by  holding  the  cotton  in  its  teeth,  wUl  commence  its  cardin*'  The 
small  runner  A,  in  consequence  of  its  greater  surface  velocity  (5170  inches  per  minuie\ 
will  comb  the  cotton-wool  back  out  of  the  teeth  of  the  large  runner,  but  it  will  give  it 
up  in  Its  turn  to  the  swifter  teeth  of  the  drum,  which,  in  carrying  it  forwards,  encoun- 
ters the  teeth  of  the  top  cards,  and  delivers  up  the  filaments  to  their  keeping  for  some 
time.  We  thus  see  how  essential  the  runners  are  to  the  perfection  as  well  al  to  the  ac- 
celeration of  the  carding  process  for  ordinary  cotton  wool,  though  for  the  slenderer  and 
.onger  filaments  of  the  sea-island  kind  they  are  not  so  well  adapted.  In  cleaning'  the 
carding-engmes  the  httle  runner  must  be  looked  to  every  time  that  the  drum  is  examined. 
The  large  runner  and  the  doffer  require  to  be  cleaned  together.  The  quantity  of  cotton 
spread  upon  the  feed^iloth,  the  velocity  of  it,  and  of  the  drawing-rollers,  must  all  be 
carefully  adjusted  to  the  grist  of  the  yam  intended  to  be  spun. 

Suppose  the  sizes  and  velocities  to  be  as  represented  in  the  preceding  table,  that  the 
engine  is  a  double  card  36  inches  broad,  and  that  it  is  furnished  with  a  lap  from  the  lan- 
machme  of  which  30  feet  in  length  weigh  5  lbs.  In  one  minute  the  surface  of  the  feedl 
rollers  e,  passes  255  inches  of  that  lap  onwards;  in  the  same  time  the  main-drum  wUI 
work  It  ofl.  To  card  the  whole  30  feet,  therefore,  141  minutes,  or  2  hours  and  21  minutes 
wiUbe  required.  In  this  time  the  circumference  of  the  rollers,  «  r,  moves  throueh  a 
space  of  141X42,908  in  =5042  ft.,  and  delivers  a  card-end  of  thatTngth,w^^^^^^ 
?079*'f.Tr  r'  ''"^-  ^""'T^'^f'  Ihat  is,  4  lbs.  1 1|  oz.  One  pound  will  form  a  riband 
.v-Jlr  Vr^'  t^'"?'  ^T:?^"?  ^°  ^\^  English  mode  of  counting,  about  number  |,  or 
Ml  T  ^J-T'T  ^/  ^}^^  cotton-fleece  to  this  degree  proceeds  as  follows  :-In  the 
141  minutes  which  the  feed-rollers  take  to  introduce  the  30  feet  of  lap,  the  dotferT 
makes  617-08  revolutions  and  the  comb,  or  doffer  knife,  t,  detaches  from Ve  doffer  te'eth 
a  thm  fleecy  web  of  2262  feet  in  length.    The  first'  drawing  pair  of  fluted  rollers, 

by  its  quick  motion,  with  the  aid  of  the  funnel, 
wj,  converts  this  fleece  into  a  riband  2535  feet 
long.  The  second  pair  of  the  fluted  rollers  ex- 
tends this  riband  to  4390  feet,  since  their  sur- 
face velocity  is  greater  than  the  first  pair  in  that 
proportion.  The  slight  elongation  (of  only  112 
feet,  or  about  -I- )  which  takes  place  between 
the  delivery  fluted  rollers  and  the  smooth  cylin- 
ders, Vy  tt,  serves  merely  to  keep  the  card-end 
steadily  upon  the  stretch  without  folding.  Fig, 
398  is  a  plan  of  the  card  and  the  fleece,  where  h 
is  the  cylinder,  n  is  the  funnel,  u  the  pressing 
rollers,  and  A'  the  card-ends  in  the  can. 


COTTON  MANUFACTURJ:. 


513 


Fig»,  399, 400,  represent  skeletons  of  the  old  cards  to  facilitate  the  comprehens'.on  of 
these  complex  machines.    Fig,  399  is  a  plan ;  f  is  the  main  drum ;  m  m  is  the  doffef 


knife  or  comb ;  g  the  carded  fleece  hemmed  in  by  the  funnel  a,  pressed  between  the  roll* 
ers  6,  and  then  falling  in  narrow  fillets  into  its  can.  Fig.  400,  k  l  are  the  feed  rollers; 
A  B  the  card  drum  ;  c  d  the  lops ;  e  f  the  doffer  card ;  m  k  the  doffer  knife ;  d-  6,  c,  the 
card-end  passing  between  compressing  rollers  into  the  can  a. 

The  drawing  and  doubling  are  the  next  operation.  The  ends,  as  they  come  from  the 
cards,  are  exceedingly  tender  and  loose,  but  the  filaments  of  the  cotton  are  not  as  yet  laid 
80  parallel  with  each  other  as  they  need  to  be  for  machine  spinning.  Before  any  degree 
of  torsion  therefore  be  communicated,  a  previous  process  is  required  to  give  the  filaments 
a  level  arrangement  in  the  ribands.  The  drawing  out  and  doubling  accomplish  this  pur- 
pose, and  in  a  manner  equally  simple  and  certain.  The  means  employed  are  drawing- 
rollers,  whose  construction  must  here  be  fnlly  explained,  as  it  is  employed  in  all  the  fol- 
lowing machines ;  one  example  of  their  use  occurred,  indeed,  in  treating  of  the  cards. 

Let  a  and  6,  fig.  401,  represent  the  section  of  two  rollers  lying 
over  each  other,  which  touch  with  a  regulated  pressure,  and  turn  in 
contact  upon  their  axes,  in  the  direction  shown  by  the  arrows. 
These  rollers  will  lay  hold  of  the  fleecy  riband  presented  to  them  at 
a,  draw  it  through  between  them,  and  deliver  it  quite  unchanged. 
The  length  of  the  piece  passed  through  in  a  given  time  will  be 
equal  to  the  space  which  a  point  upon  the  circumference  of  the 
roller  would  have  percured  in  the  same  time ;  that  is,  equal  to  the 
periphery  of  one  of  the  rollers  multiplied  by  the  number  of  its  en- 
tire revolutions.  The  same  thing  holds  with  regard  to  the  trans- 
mission of  the  riband  through  between  a  second  pair  of  rollers, 
c,  rf,  and  a  third,  e,f.  Thus  the  said  riband  issues  from  the  third  pair  exactly  the  same 
as  if  entered  at  a,  provided  the  surface  speed  of  all  the  rollers  be  the  same.  But  if  the 
surface  speed  of  c  and  d  be  greater  than  that  of  a  and  6,  then  the  first-named  pair  will 
deliver  a  greater  length  of  riband  than  the  last  receives  and  transmits  to  it.  The  conse- 
quence can  be  nothing  else  in  these  circumstances  than  a  regulated  drawing  or  elonga- 
tion of  the  riband  in  the  interval  betwixt  a,  6,  and  c,  d,  and  a  condensation  of  the  fila- 
ments as  they  glide  over  each  other,  to  assume  a  straight  parallel  direction.  In  like 
manner  the  drawing  may  be  repeated  by  giving  the  rollers,  e,f,  a  greater  surface  speed 
than  that  of  the  rollers,  c  and  d.  This  increase  of  velocity  may  be  produced,  either  by 
enlarging  the  diameter,  or  by  increasing  the  number  of  turns  in  the  same  lime,  or 
finally  by  both  methods  conjoined.  In  general  the  drawing-machine  is  so  adjusted,  that 
the  chief  elongation  takes  place  between  the  second  and  third  pair  of  rollers,  while  that 
between  the  first  and  second  is  but  slight  and  preparatory.  It  is  obvious,  besides,  that 
the  speed  of  the  middle  pair  of  rollers  can  have  no  influence  upon  the  amount  of  the 
extension,  provided  the  speed  of  the  first  and  third  pair  remains  unchanged.  The  roll- 
ers, flf,  b,  and  c,  d,  maintain  towards  each  other  continually  the  same  position,  but  they 
may  be  removed  with  their  frame-work,  more  or  less,  from  the  third  pair,  e,f,  according 
as  the  length  of  the  cotton  staple  may  require.  The  distance  of  the  middle  point  from 
6  and  d,  or  its  line  of  contact  with  the  upper  roller,  is,  once  for  all,  so  calculated,  that  it 
shall  exceed  the  length  of  the  cotton  filaments,  and  thereby  that  these  filaments  are  never 
in  danger  of  being  lorn  asunder  by  the  second  pair  pulling  them  while  the  first  holds 
them  fast.  Between  d  and/,  where  the  greatest  extension  lakes  place,  the  distance  must 
be  as  small  as  it  can  be  without  risk  of  tearin?  them  in  that  way ;  for  thus  will  the  uni- 
formity of  the  drawing  be  promoted.  If  the  distance  between  d  and  /  be  very  ereat,  a 
riband  passing  through  will  become  thinner, or  perhaps  break  in  the  middle;  whe.ix,e  we 
see  that  the  drawing  is  more  equable,  the  shorter  is  the  portion  submitted  to  extension  at 
a  time,  and  the  nearer  the  rollers  are  to  each  other,  supposing  Jiem  always  distant 
enough  not  to  tear  the  staple. 


514 


COTTON  MANUFACTURE. 


The  under  rollers,  6  rf/,  are  made  of  iron,  and,  to  enable  them  to  lay  firmer  hold  of  th« 
filaments,  their  surfaces  are  fluted  with  triangular  channels  parallel  to  their  axes.  Th« 
upper  rollers,  a  c  e,  are  also  made  of  iron,  but  they  are  smooth,  and  covered  with  a  dou- 
ble coating,  which  gives  them  a  certain  degree  of  softness  and  elasticity.  A  coat  of 
flannel  is  first  applied  by  sewing  or  glueing  the  ends,  and  then  a  coat  of  leather  in  the 
same  way.  The  junction  edges  of  the  leather  are  cut  slanting,  so  that  when  joined  by 
the  glue  (made  of  isinglass  dissolved  in  ale)  the  surface  of  the  roller  may  be  smoothly 
cylindrical.  The  top  rollers  are  sometimes  called  the  pressersy  because  they  press  by 
means  of  weights  upon  the  under  ones.  These  weights  are  suspended  to  the  slight  rods 
k  k' ;  of  which  the  former  operates  on  the  roller  e  alone,  the  latter  on  the  two  rollers 
a  and  e  together.  For  this  purpose  the  former  is  hung  to  a  c  shaped  curve  t,  whose 
upper  hook  embraces  the  roller  e ;  the  latter  to  a  brass  saddle  A,  which  rests  upon  a  and 
c.  A  bar  of  hard  wood,  g,  whose  under  surface  is  covered  with  flannel,  rests,  with 
merely  its  own  weight,  upon  the  top  roller,  and  strips  off"  all  the  loose  hanging  filaments. 
Similar  bars  with  the  same  view  are  made  to  bear  up  under  the  fluted  rollers  6  d  /,  and 
press  against  them  by  a  weight  acting  through  a  cord  passing  over  a  pulley.  Instead 
of  the  upper  dust-covers,  light  wooden  rollers  covered  with  flannel  are  occasionally 
applied. 

Were  the  drawing  of  a  riband  continued  till  all  its  fibres  acquired  the  desired  degree 
of  parallelism,  it  would  be  apt,  from  excessive  attenuation,  to  tear  across,  and  thereby 
to  defeat  the  purpose  of  the  spinner.  This  dilemma  is  got  rid  of  in  a  very  simple  way, 
namely,  by  laying  several  ribands  together  at  every  repetition  of  the  process,  and  incor- 
porating them  by  the  pressure  of  the  rollers.  This  practice  is  called  doubling.  It  is  an 
exact  imitation  of  what  takes  place  when  we  draw  a  tuft  of  cotton  wool  between  our 
fingers  and  thumb  in  order  to  ascertain  the  length  of  the  staple,  and  replace  the  drawn 
filaments  over  each  other,  and  thus  draw  them  forth  again  and  again,  till  they  are  all 
parallel  and  of  nearly  equal  length.  The  doubling  has  another  advantage,  that  of  causing 
the  inequalities  of  thickness  in  the  ribands  to  disappear,  by  applying  their  thicker  to  theix 
thinner  portions,  and  thereby  producing  uniformity  of  substance. 


402 


^    11 


The  drawing  frame,  as  shown  in  section  in  figs.  401,  403,  and  in  a  back  view  in  fig, 
402,  will  require,  after  the  above  details,  little  further  explanation.  /  /  are  the  weights 
which  press  down  the  top  rollers  upon  the  under  ones,  by  means  of  the  rods  k  k'  and  hook 
t.  Each  fluted  roller  is,  as  shown  at/,  ^g.  402,  provided  in  the  middle  of  its  length  with 
a  thinner  smooth  part  called  the  neck,  whereby  it  is  really  divided  into  two  fluted  portions, 
represented  by  c  e  in  the  figure.  Upon  this  middle  neck  in  the  pressure  rollers,  the  hook 
t  and  the  saddle  h  immediately  bear,  as  shown  in  the  former ^ig.  401.  The  card-ends,  to 
the  number  probably  of  six,  are  introduced  to  the  drawing  frame  either  from  tin  cans, 
placed  at  e  e,fig.  403,  and  at  a,  fig.  402,  or  from  lap-bobbins ;  and,  after  passing  through  it, 
the  ribands  or  slivers  are  received  either  into  similar  tin  cans,  as  g,  or  upon  other  lap- 
bobbins  upon  the  other  side.  These  appendages  may  be  readily  conceived,  and  are  therefore 
not  exhibited  in  all  the  drawings.  Three  of  the  slivers  being  laid  together  are  again  intro- 
duced to  the  one  fluted  portion  a  b,fig.  401,  and  three  other  slivers  to  the  other  portion* 
The  sloping  curved  tin  or  brass  plate  s,  fig.  402,  with  its  guide  pins  /,  serves  to  conduct 
the  slivers  to  the  rollers.  When  the  two  threefold  slivers  have  passed  through  between  the 
three  pairs  of  rollers,  and  been  thereby  properly  drawn,  they  run  towards  each  other  in  aq 
cUique  direction,  behind  the  last  roller  pair  e  f,fig.  401,  and  unite,  on  issuing  through  tbt 


COTTON  MANUFACTURE. 


515 


eonical  funnel  m,  yig.  402,  into  a  single  riband  or  spongy  sliver ;  which  is  immeJiatel> 
carried  olf  with  equable  velocity  by  two  smooth  cast-iron  rollers,  n  o,figs.  402  and  403, 
and  either  dropped  into  a  can,  or  wound  upon  a  large  bobbin.  The  surface  speed  of 
these  rollers  is  made  a  trifle  greater  than  that  of  the  delivery  drawing  rollers,  in  order  to 
keep  the  portion  of  sliver  between  them  always  in  an  extended  state.  Four  fluted  draw- 
ing portions  are  usually  mounted  in  one  drawing  frame,  which  are  set  a-going  or  at  rest 
together.  To  save  all  unnecessary  carrying  of  the  cans  from  the  back  to  the  front  of 
the  frame,  the  drawing  heads  are  so  placed,  that  the  first  and  third  discharge  their  slivers 
at  the  one  side,  and  the  second  and  fourth  at  the  other.  By  this  arrangement,  the  cans 
filled  behind  one  head,  are  directly  pushed  aside  in  front  of  the  next  drawing  head ;  by 
which  alternate  distribution  the  work  goes  on  without  interruption. 

The  fast  pulley  u^fig.  403,  by  which  the  whole  machine  is  driven,  derives  its  motion 
from  the  main  shaft  of  the  mill  by  means  of  the  band  w.  The  similar  pulley  z,  which 
sits  loose  upon  the  axis,  and  turns  independently  of  it,  is  called  the  loose  pulley ;  both 
together  being  technically  styled  riggers.  "When  the  operative  desires  to  stop  the  ma- 
chine, he  transfers  the  band  from  the  fast  to  the  loose  pulley  by  means  of  a  lever,  bearing 
a  fork  at  its  end,  which  embraces  the  band.  Upon  y,  four  pulleys  such  as  x  are  fixed, 
each  of  which  sets  in  motion  a  drawing  head,  by  means  of  a  band  like  w  going  round 
the  pulleys  x  and  ft.  On  account  of  the  inverted  position  of  the  heads,  which  requires 
the  motion  of  u  to  be  inverted,  the  bands  of  the  first  and  third  heads  are  open,  but  those 
of  the  second  and  fourth  are  crossed.  Every  head  is  provided  with  a  loose  pulley  r,  as  well 
as  the  fast  pulley  u,  in  order  to  make  the  one  stop  or  move  without  affecting  the  others. 
The  shaft  of  the  pulley  «  is  the  prolonged  shaft  of  the  backmost  fluted  roller  /.  It  car- 
ries besides  a  small  pulley  q,  which,  by  means  of  the  band  r,  and  the  pulley  p^fig.  402, 
sets  in  motion  the  undermost  condensing  roller  o.  The  upper  roller  n  presses  with  its 
whole  weight  upon  it,  and  therefore  turns  by  friction.  The  toothed  wheel-work,  by 
which  the  motions  are  communicated  from  the  backmost  fluted  roller  to  the  middle  and 
front  ones,  is  seen  in^g.  403. 

The  wheel /,/g.  401,  of  20  teeth,  works  in  a  44-toothed  carrier-wheel,  on  whose 
axis  there  are  two  smaller  wheels;  2  with  26  teeth,  and  1  with  22  teeth.  The  wheel  d, 
fig.  403  of  the  middle  roller,  and  the  wheel  h  of  the  front  roller,  are  set  in  motion  by  other 
carrier  wheels ;  the  first  has  27  teeth,  and  the  last  40.  For  every  revolution  of  6,  the 
roller  d  makes  nearly  If  turns,  and  the  roller  /  4  revolutions.  The  top  rollers  revolve, 
as  we  have  stated,  simply  by  the  friction  of  contact  with  the  lower  ones.  Now  suppose 
the  diameter  of  the  rollers  h  and  d  to  be  1  inch  or  12  lines,  that  of/  \\  inches  or  15 
lines,  the  surface  velocities  of  the  three  pairs  of  rollers  in  the  series  will  be  as  1,  If,  and 
5.  Every  inch  of  the  cotton  sliver  will  be  therefore  extended  between  the  first  and  second 
pairs  of  rollers  into  If  inches,  and  between  the  second  and  third  or  delivery  pair  into  6 
inches ;  and  after  the  sliver  has  passed  through  all  the  four  drawing  heads,  its  length 
will  be  increased  625  times  =r  5  X  5  X  5  X  5- 

The  further  the  drawing  process  is  pushed,  the  more  perfectly  will  its  object  be  ac- 
complished, namely,  the  parallelism  of  the  filaments.  The  fineness  of  the  appearance 
of  the  sliver  after  the  last  draught  depends  upon  the  number  of  doublings  conjointly 
with  the  original  fineness  and  number  of  drawings.  The  degree  of  extension  may  be 
increased  or  diminished,  by  changing  the  wheels  in  fig.  403,  for  others  with  a  diflferent 
number  of  teeth.  Thus  the  grist  or  fineness  of  the  sliver  may  be  modified  in  any  desired 
degree ;  for,  when  the  subsequent  processes  of  the  mill  remain  the  same,  the  finer  the 
drawings  the  finer  will  be  the  yarn.  For  spinning  coarse  numbers  or  low  counts,  for 
example,  six  card-ends  are  usually  transmitted  through  the  first  drawing  head,  and  con- 
verted into  one  riband.  Six  such  ribands  again  form  one  in  the  second  draught ;  six  of 
these  again  go  together  into  the  third  sliver ;  and  this  sliver  passes  five-fold  through  the 
last  draught.  By  this  combination  1080  of  the  original  card-ends  are  united  in  the 
finished  drawn  sliver  =6  X  6  X  6  X  5.  The  fineness  of  the  sliver  Is,  however,  in  conse- 
quence of  these  doublings,  not  increased,  but  rather  diminished.  For,  by  the  drawing, 
the  card-end  has  been  made  625  times  longer,  and  so  much  smaller ;  by  the  doubling 
alone  it  would  have  become  1080  times  thicker ;  therefore,  the  original  grist  is  to  the 
i  resent  as  1  to  the  fraction  t^^tt  5  ^^^^  is,  supposing  1072  feet  of  the  riband  delivered 
by  the  card  to  weigh  one  pound,  625  feet,  the  sliver  of  the  last  drawing,  will  also  weigh 
a  pound,  which  corresponds  in  fineness  to  number  0*24,  or  nearly  \. 

The'rearmost  or  last  drawing  roller  has  a  circumference  of  nearly  4  inches,  and  makes 
about  150  revolutions  per  minute;  hence,  each  of  these  drawing  heads  may  turn  off 
35,000  feet  of  sliver  in  12  hours. 

Some  manufacturers  have  lately  introduced  a  double  roller  beam,  and  a  double  draught 
at  the  same  doubling,  into  their  drawing  frames.  I  have  seen  this  contrivance  working 
satisfactorily  in  mills  where  low  counts  were  spun,  and  where  the  tube  roving  frame  was 
employed ;  but  I  was  informed  oy  competent  judges,  that  it  was  not  advisable  where  a 
level  yam  was  required  for  good  printing  calicoes 


1 


I' 


516 


COTTON  MANUFACTURE. 


The  loss  which  the  cotton  suffers  in  the  drawing  frame  is  quite  inconsiderable.  It 
consists  of  those  filaments  which  remain  upon  the  drawing  rollers,  and  collect,  in  a 
great  measure,  upon  the  flannel  facing  of  the  top  and  bottom  cleaner  bars.  It  is  thrown 
among  the  lop  cleanings  of  the  carding  engine.  When  from  some  defect  in  the  rollers, 
or  negligence  in  piecing  the  running  slivers,  remarkably  irregular  portions  occur 
in  the%ibands,  these  must  be  torn  off,  and  returned  to  the  lap  machine  to  be  carded 

anew. 

The  fiAh  operation  may  be  called  the  first  spinning  process,  as  in  it  the  cotton  sliver 
receives  a  twist ;  whether  the  twist  be  permanent,  as  in  the  bobbin  and  fly  frame,  or  be 
undone  immediately,  as  in  the  tube-roving  machine.  In  fact,  the  elongated  slivers  of 
parallel  filaments  could  bear  little  further  extension  without  breaking  asunder,  unless  the 
precaution  were  taken  to  condense  the  filaments  by  a  slight  convolution,  and  at  the  same 
time  to  entwine  them  together.  The  twisting  should  positively  go  no  further  than  to 
fulfil  the  purpose  of  giving  cohesion,  otherwise  it  would  place  an  obstacle  in  the  way  of 
the  future  attenuation  into  level  thread.  The  combination  of  drawing  and  twisting  is 
what  mainly  characterizes  the  spinning  processes,  and  with  this  fifth  operation,  therefore, 
commences  the  formation  of  yarn.  As,  however,  a  sudden  extension  to  the  wished-for 
fineness  is  not  practicable,  the  draught  is  thrice  repeated  in  machine  spinning,  and  after 
each  draught  a  new  portion  of  torsion  is  given  to  the  yarn,  till  at  last  it  possesses  the 
degree  of  fineness  and  twist  proportioned  to  its  use. 

The  prelimmary  spinnmg  process  is  called  roving.  At  first  the  torsion  is  slight  in 
Oronortion  to  the  extension,  since  the  solidity  of  the  still  coarse  sliver  needs  that  cohesive 

aid  only  in  a  small  degree,  and  looseness 
of  texture  must  be  maintained  to  facilitate 
to  the  utmost  the  further  elongation. 

Fig.  404  is  a  section  of  the  can  rovinf 
frame,  the  ingenious  invention  of  Ark 
Wright,  which,  till  within  these  14  years> 
was  the  principal  machine  for  communi 
eating  the  incipient  torsion  to  the  spongi 
cord  furnished  by  the  drawing  heads.  Ir 
differs  from  that  frame  in  nothing  bni 
the  twisting  mechanism ;  and  consists  oi 
two  pairs  of  drawing  rollers,  a  and  b,  be 
tween  which  the  sliver  is  extended  in  the 
usual  way ;  c  are  brushes  for  cleaning  th^ 
rollers ;  and  d  is  the  weight  which  presses 
the  upper  set  upon  the  lower.  The  wiping 
covers  (not  shown  here)  rest  upon  a  b. 
The  surface  speed  of  the  posterior  or  second 
pair  of  rollers  is  3,  4,  or  5  times  greatei 
than  that  of  the  front  or  receiving  pair, 
according  to  the  desired  degree  of  attenua* 
tion.  Two  drawn  slivers  were  generally  united  into  one  by  this  machine,  as  is  shown  is 
the  figure,  where  they  are  seen  coming  from  the  two  cans  e  e,  to  be  brought  together  by 
the  pressure  rollers,  before  they  reach  the  drawing  rollers  a  b.  The  sliver,  as  it  escape? 
from  these  rollers,  is  conducted  into  the  revolving  conical  lantern  g,  through  the  funnel 
/  at  its  top.  This  lantern-can  receives  its  motion  by  means  of  a  cord  passing  over  a 
pulley  fe,  placed  a  little  way  above  the  step  on  which  it  turns.  The  motion  is  steadied 
by  the  collet  of  the  funnel  /,  being  embraced  by  a  brass  busk.  Such  a  machine  gene- 
rally contained  four  drawing  heads,  each  mounted  with  two  lanterns;  in  whose  side  there 
was  a  door  for  taking  out  the  conical  coil  of  roving. 

The  motion  imparted  to  the  back  roller  by  the  band  pulley  or  rigger  m,  was  conveyed 
to  the  front  one  by  toothed  wheel  work. 

The  vertical  guide  pulley  at  bottom,  n,  served  to  lead  the  driving  band  descending 
from  the  top  of  the  frame  round  the  horizontal  whorl  or  pulley  upon  the  under  end  of 
the  lantern.  The  operation  of  this  can-frame  was  pleasing  to  behold ;  as  the  centrifugal 
force  served  both  to  distribute  the  soft  cord  in  a  regular  coU,  and  also  to  condense  a  great 
deal  of  it  most  gently  within  a  moderate  space.  Whenever  the  lantern  was  filled,  the 
tenter  carried  the  roving  to  a  simple  machine,  where  it  was  wound  upon  bobbins  by 
hand.  Notwithstanding  every  care  in  this  transfer,  the  delicate  texture  was  verj'  apt  to 
be  seriously  injured,  so  as  to  cause  corresponding  injuries  in  every  subsequent  operation, 
mnd  in  the  finished  yarn.  Messrs.  Cocker  and  Higgins,  of  Salford,  had  the  singular 
merit,  as  I  have  said,  of  superseding  that  beautiful  but  defective  mechanism,  which  had 
held  a  prominent  place  in  all  cotton  mills  from  almost  the  infancy  of  the  factory  system, 
by  the  following  apparatus. 
The  Bobbin  and  Fly  frame  is  now  the  great  roving  machine  of  the  cotton  manufa^ 


COTTON  MANUFACTURE. 


!^n 


tore ;  to  which  may  be  added,  for  coarse  spinning,  the  tube  roving  frame.     Of  such  « 
complicated  machine  as  the  bobbin  and  fly  frame,  it  is  not  possible  to  give  an  ade- 

quately  detailed  description  in  the 
space  due  to  the  subject  in  this 
Dictionary.  Its  mechanical  com- 
binations are,  however,  so  admira- 
ble as  to  require  such  an  account 
as  will  make  its  functions  inteUi- 
gible  by  the  general  reader. 


Fig.  405  exhibits  a  back  view  oi" 
this  machine ;  and  fig.  406  a  sec- 
tion of  some  of  the  parts  not  very 
visible  in  the  former  figure.  The 
back  of  the  machine  is  the  side  at 
which  the  cotton  is  introduced  be- 
tween the  drawing  rollers. 

The  cans,  or  lap-bobbins  filled 
with  slivers  at  the  drawing  frame, 
are  placed  in  the  situation  marked 
B,  fig.  406,  in  rows  parallel  with 
the  length  of  the  machine.     The 
sliver  of  each  can,  or  the  united 
slivers  of  two  contiguous  cans,  arc 
conducted  upwards  along  the  sur 
face    of   a   sloping   board  f,   and 
through  an  iron  staple  or  guide  e, 
betwixt  the  usual  triple  pair  of 
drawing  rollers,  the  fiirst  of  which 
is  indicated  by  a,  b.     In  fig.  405, 
for  the  purpose  of  simplifying  the 
figure,  the  greater  part  of  these 
rollers  and  their  subordinate  parts 
are    omitted.     After    the    slivers 
have    been    sufficiently    extended 
and  attenuated  between  the  rollers, 
they  proceed  forwards,  towards  the 
spindles  1 1 1,  where  they  receive 
the  iwist,  and  are  wound  upon  the 
bobbins  h.    The  machine  deline 
ated  contains  thirty  spindles,  but 
many  bobbin  and  fly  frames  con- 
tain double  or  even  four  times  that 
number.    Only  a  few  of  the  spin 
dies  are  shown  in^g.  405,  for  feai 
of  confu.sing  the  drawing. 
With  regard  to  the  drawing  functions  of  this  machine,  I  have  already  given  abundanJ 


518 


COTTON  MANUFACTURE. 


explanation,  so  far  as  the  properties  and  operation  of  the  rollers  are  concerned.  The 
frame-work  of  this  part  of  the  machine,  called  the  rolUr^am,  is  a  cast-iron  bench  npo» 
which  nine  bearers,  c,  are  mounted  for  carrying  the  rollers.  The  fluted  rollers  aaa  fig, 
407,  are  constructed  in  four  pieces  for  the  whole  length,  which  are  parted  from  each 
other  by  tliinner  smooth  cylindric  portions,  z,  called  necks.  Seven  such  partings  for 
four  rollers,  and  one  parting  for  two  rollers,  constitute  together  the  30  fluted  rollers  of 
which  the  whole  series  consists.  The  coupling  of  these  roller  subdivisions  into  one 
cylinder,  is  secured  by  the  square  holes  x,  and  square  pins  y,fig.  407,  which  fit  into  the 

holes  "of  the  adjoining  subdivision.  The 
top  or  pressure  rollers  b,  are  two-fold  over 
the  whole  set;  and  the  weighted  saddle 
presses  upon  the  neck  tr,  which  connects 
*     .no      rrv  .  ^  ^^^^y  P^'""*  ^s  ^^^'s  already  explained  under 

fig,W2.  These  weights  g  g,yig.406,  are  applied  in  this  as  in  the  drawing  frame ;  d  are 
the  bars  faced  with  flannel  for  cleaning  the  top  rollers.  A  similar  bar  is  applied  beneath 
the  rollers,  to  keep  the  flutings  clean. 

The  structure  and  operation  of  the  spindles  t  may  be  best  understood  by  examining 
the  section  Jig.  408.     They  are  made  of  iron,  are  cylindrical  from 
the  top  down  to  a2,  but  from  this  part  down  to  the  steel  tipped  rounded 
points  they  are  conical.     Upon  this  conical  portion  there  is  a  pulley 
k,  furnished  with  two  grooves  in  its  circumference,  in  which  the  cord 
runs  that  causes  the  spindle  to  revolve.    The  wooden  bobbin  h  ia 
slid  upon  the  cylindrical  part,  which  must  move  freely  upon  it,  as 
will  be  presently  explained.     To  the  bobbin  another  two-grooved 
pulley  or  whorl  g  is  made  fast  by  means  of  a  pin  r,  which  passes 
through  it ;  by  removing  this  pin,  the  bobbin  can  be  instantly  taken 
oflT  the  spindle.     The  upper  end  of  the  spindle  bears  a  fork  s  t, 
which  may  be  taken  ofl"  at  pleasure  by  means  of  its  lefl-handed 
screw ;  this  fork,  or  flier,  has  a  funnel-formed  hole  at  r.     One  arm 
of  the  fork  is  a  tube,  .v,  u,  open  at  top  and  bottom ;  the  leg,  t,  is 
added  merely  as  a  counterpoise  to  the  other.     In  fig.  406,  for  the 
sake  of  clearness,  the  forks  or  fliers  of  the  two  spindles  here  repre- 
sented are  left  out ;  and  in  fig.  405,  only  one  is  portrayed  for  the 
same  reason.     It  is  likewise  manifest  from  a  comparison  of  these 
two  figures  that  the  spindles  are  alternately  placed  in  two  rows,  so 
that  each  spindle  of  the  back  range  stands  opposite  the  interval 
between  two  in  the  front  range.    The  object  of  this  distribution 
is  economy  of  space,  as  the  machine  would  need  to  be  greatly  longer 
if  the  spindles  stood  all  in  one  line.     If  we  suppose  the  spindles  and 
the  bobbins  (both  of  which  have  independent  motions)  to  revolve 
simultaneously  and  in  the  same  direction,  their  operation  will  be 
as  follows:  The  sliver,  properly  drawn  by  the  fluted  rollers,  enters 
the  opening  of  the  funnel  v,  proceeds  thence  downwards  through 
the  hole  in  the  arm  of  the  fork,  runs  along  its  tube  «,  *,  and  then 
winds  round  the  bobbin.    This  path  is  marked,  in  fig.  408,  by  a  dot- 
ted line. 

The  revolution  of  the  spindles  in  the  above  circumstances  effects  the  twisting  of  the 
Oliver  into  a  soft  cord;  and  the  flier  s,  ty  or  particularly  its  tubular  arm  s,  lavs  this  cord 
upon  the  bobbin.  Were  the  speed  of  the  bobbins  equal  to  that  of  the  spindles,  that  is, 
did  the  bobbin  and  spindle  make  the  same  number  of  turns  in  the  same  lime,  the  pro- 
cess would  be  limited  to  mere  twisting.  But  the  bobbin  anticipates  the  fliers  a  little, 
that  is,  it  makes  in  a  given  time  a  somewhat  greater  number  of  revolutions  than  the 
spindle,  and  thereby  effects  the  continuous  winding  of  the  cord  upon  itself.  Suppose 
the  bobbin  to  make  40  revolutions,  while  the  spindle  completes  only  30 ;  30  of  these  revo- 
lutions of  the  bobbin  will  be  inoperative  towards  the  winding-on,  because  the  fliers  fol- 
low at  that  rate,  so  that  the  cord  or  twisted  sliver  will  only  be  coiled  10  times  round  the 
bobbin,  and  the  result  as  to  the  winding-on  will  be  the  same  as  if  the  spindle  had  stood 
still,  and  the  bobbin  had  made  40  —  30  =  10  turns.  The  30  turns  of  the  spindles  serve, 
therefore,  merely  the  purpose  of  communicating  twist. 

The  mounting  and  operation  of  the  spindles  are  obvious-.y  the  same  as  they  are  upon 
the  household  flax  wheel.  In  the  bobbin  and  fly  frame  there  are  some  circumstances 
which  render  the  construction  and  the  winding-on  somewhat  difficult,  and  the  mechanism 
not  a  little  complicated.  It  may  be  remarked,  in  the  first  place,  that  as  the  cord  is  wound 
on,  the  diameter  of  the  bobbin  increases  very  rapidly,  and  therefore  every  turn  made 
round  it  causes  a  greater  length  of  rovins  to  be  taken  up  in  succession.  Were  the 
motions  of  the  bobbins  to  continue  unchanged  in  this  predicament,  the  increased 
Telocity  of  the  winding-on  would  require  an  increased  degree  of  extension,  or  it  wouU 


COTTON  MANUFACTURE. 


519 


occasion  the  rupture  of  the  cord,  because  the  front  fluted  rollers  move  with  uniform 
speed,  and  therefore  deliver  always  the  same  length  of  sliver  in  the  same  time.  ,It 
is  therefore  necessary  to  diminish  the  velocity  of  the  bobbins,  or  the  number  of  their 
turns,  in  the  same  proportion  as  their  diameter  increases,  in  order  that  the  primary 
velocity  may  remain  unchanged.  Moreover,  it  is  requisite  for  the  proper  distribution 
of  the  cord  upon  the  bobbin,  and  the  regular  increase  of  its  diameter,  that  two  of  its 
•uccessive  convolutions  should  not  be  applied  over  each  other,  but  that  they  should  be 
laid  close  side  by  side.  This  object  is  attained  by  the  up  and  down  sliding  motion  of  the 
bobbin  upon  the  spindle,  to  the  same  extent  as  the  length  of  the  bobbin  barrel.  This 
up  and  down  motion  must  become  progressively  slower,  since  it  increases  the  diameter 
of  the  bobbin  at  each  range,  by  a  quantity  equal  to  the  diameter  of  the  sliver.  What 
has  now  been  stated  generally,  will  become  more  intelligible  by  an  example. 

Let  it  be  assumed  that  the  drawing  rollers  deliver,  in  10  seconds,  45  inches  of 
roving,  and  that  this  length  receives  30  twists.  The  spindles  must,  in  consequence, 
make  30  revolutions  in  10  seconds,  and  the  bobbins  must  turn  with  such  speed,  that 
they  wind  up  the  45  inches  in  10  seconds.  The  diameter  of  the  bobbin  barrels  being 
Ij^  inches,  their  circumference  of  course  4^  inches,  they  must  make  10  revolution^more 
in  the  same  lime  than  the  spindles.  The  effective  speed  of  the  bobbins  will  be  thus 
30-|-10=:40  turns  in  10  seconds.  Should  the  bobbins  increase  to  3  inches  diameter, 
by  the  winding-on  of  the  sliver,  they  will  take  up  9  inches  at  each  turn,  and  con- 
sequently 45  inches  in  5  turns.  Their  speed  should  therefore  be  reduced  to  30-[-5=35 
turns  in  10  seconds.  In  general,  the  excess  in  number  of  revolutions,  which  the 
bobbins  must  make  over  the  spindles,  is  inversely  as  the  diameter  of  the  bobbins. 
The  speed  of  the  bobbins  must  remain  uniform  during  the  period  of  one  ascent  or 
descent  upon  the  spindle,  and  must  diminish  at  the  instant  of  changing  the  direction 
of  their  up  and  down  motion ;  because  a  fresh  range  of  convolutions  then  begins  with 
a  greater  diameter.  When,  for  example,  30  coils  of  the  sliver  or  roove  are  laid  in  one 
length  of  the  bobbin  barrel,  the  bobbin  must  complete  its  vertical  movement  up  or 
down,  within  30  seconds  in  the  first  case  above  mentioned,  and  within  60  seconds  in 
the  second  case. 

The  motions  of  the  drawing  rollers,  the  spindles,  and  bobbins,  are  produced  in  the 
following  manner : — A  shaft  c',  figs.  405  and  406,  extending  the  whole  length  of  the 
machine,  and  mounted  with  a  fly  wheel  d',  is  set  in  motion  by  a  band  from  the  running 
pulley  upon  the  shaft  of  the  mill,  which  actuates  the  pulley  a',  b'  is  the  loose  pulley 
upon  which  the  band  is  shifted  when  the  machine  is  set  at  rest.  Within  the  pulley  a', 
but  on  the  outside  of  the  frame,  the  shaft  c'  carries  a  toothed  wheel  bi  with  50  teeth, 
which  by  means  of  the  intermediate  wheel  c2  turns  the  wheel  d'2  upon  the  prolonged 
shaft  of  the  backmost  fluted  roller  (m2,  fig.  406.)  This  wheel  rfs  has  usually  54  teeth  ; 
but  it  may  be  changed  when  the  roove  is  to  receive  more  or  less  twist ;  for  as  the 
spindles  revolve  with  uniform  velocity,  they  communicate  the  more  torsion  the  less 
length  of  sliver  is  delivered  by  the  rollers  in  a  given  time.  Upon  the  same  shaft  with 
di,  a  pinion  d  of  32  teeth  is  fixed,  which  works  in  a  wheel  /a  of  72  teeth.  Within 
the  frame  a  change  pinion  g2  is  made  fast  to  the  shaft  of  /2.  This  pinion,  which  has 
usually  from  24  to  28  teeth,  regulates  the  drawing,  and  thereby  the  fineness  or  number 
of  the  roving.  It  works  in  a  48-toothed  wheel  hi  upon  the  end  of  the  backmost  fluted 
roller  a^fig.  406.  The  other  extremity  of  the  same  roller,  or,  properly  speaking,  line  of 
rollers,  carries  a  pinion  Za,  furnished  with  26  teeth,  which,  by  means  of  the  broad 
intermediate  wheel  fea,  sets  in  motion  the  pinion  t's  of  22  teeth  upon  the  middle  roller. 
When  the  diameter  of  all  the  drawing  rollers  is  the  same,  suppose  1  inch,  their  propor- 
tional velocities  will  be,  with  the  above  number  of  teeth  in  the  wheel  work,  if  g2  have 
24  teeth,  as  1  :  MS  :4-5;  and  the  drawn  sliver  will  have  4|  times  its  original  length. 
The  front  or  delivery  roller  of  the  drawing  frame  is  of  late  years  usually  made  1 J  or 
1|  inches  in  diameter.  If  625  feet  of  the  sliver  from  the  drawing  frame  weighed  one 
pound,  2790  feet  of  the  roving  will  now  go  to  this  weight,  and  the  number  will  be 
M2;  that  is,  1  hank  and  12  hundredths  to  the  pound.  The  front  pair  of  fluted 
rollers  makes  about  90  revolutions,  and  deliver?  282-6  inches  of  roving  in  the  minute, 
when  of  one  inch  diameter. 

The  spindles  i  (figs.  405  and  406),  rest,  with  their  lower  ends,  in  steps  7,  which  are 
fixed  in  an  immoveable  beam  or  bar  m.  To  protect  it  from  dust  and  cotton  filaments, 
this  beam  is  furnished  with  a  wooden  cover  n,  in  which  there  are  small  holes  for  the 
passage  of  the  spindles  right  over  the  steps.  In  fig.  405,  two  of  the  eight  covers  «,  which 
compose  the  whole  range  wi,  are  removed  to  let  the  steps  be  seen.  The  cylindrical  part 
of  each  spindle  passes  through  a  brass  ring  o ;  and  all  these  30  rings,  whose  centres 
must  be  vertically  over  the  steps  /,  are  made  fast  to  the  copping  beam  p.  This  beam 
is  so  called,  because  it  is  destined  not  merely  to  keep  the  spindles  upri?ht  by  the  rings 
attached  to  it,  but,  at  the  same  time,  to  raise  and  lower  along  the  spindles  the  bobbins 


520 


Iff 


COTTON  MANUFACTURE. 


COTTON  MANUFACTURE. 


521 


\M 


m 


Which  rest  on  these  rings;  for  which  puriKJse  the  two  racks,  or  toothed  bars  mt  nA 
made  fast  to  it,  are  designed,  as  will  be  presently  explained.  To  effect  the  revolution 
of  the  spindles,  there  are  attached  to  the  main  shaft  c'  two  whorls  or  pulleys  e'f  each 
bearing  four  grooves  of  equal  diameter.  Each  of  these  pullevs  puts  one  half  oV  the 
spindles  in  motion,  by  means  of  a  cord,  which,  after  going  round  the  whorls  k  turns 
four  times  about  the  pulleys  of  the  shaft  c'.  Two  guide  pulleys  h',  each  four-grooved 
and  two  others  t',  with  a  single  groove,  which  turn  independently  of  the  others  upon 
the  above  shaft,  serve  to  give  the  whorl  cords  the  proper  direction,  as  well  as  to'  keep 
them  tight.  The  spindles  revolve  200  times  or  thereby  in  the  minute ;  and  therefore 
impart  two  turns  or  twists  to  every  three  inches  of  the  roving. 

The  revolution  of  the  bobbins  is  independent  of  that  of  the  spindles,  althou«»h  it  like- 
wise proceeds  from  the  shaft  c',  and  differs  from  it  in  being  a  continually  retarded 
motion.  The  simplest  method  of  effecting  this  motion,  is  by  means  of  the  wooden  or 
Un  plate  cone  &',  which  revolves  equaDy  with  the  shaft  c',  and  at  the  same  time  slides 
along  It. 

The  manner  in  which  this  operates  is  shown  in  section  in  Jig.  409.  Here  we  per- 
ceive the  rod  52,  which  extends  from  the  base  toward  the  narrow  end  of  the  truncated 
eone,  dhd  pi  a  forked  bearer  or  carrier  made  fast  to  the  shaft  c  by  a  screw,  which 
compels  the  cone,  by  means  of  that  rod,  to  obey  the  movements  of  c'.     In  the  large  end 


Of  the  cone  there  is  an  aperture,  throush  which  the  bearer  can  be  ?ot  at.  The  smaller 
end  carries  outside  a  projection  02,  provided  with  a  groove,  which  is  embraced  by  the 
^rked  end  of  a  rod  q'.fig.  410,  that  serves  to  shove  the  cone  alon?  upon  the  sh^  C 
Directly  under  the  cone,  there  is  an  upright  round  pillar  p\  upon  which  the  holder  ff 
of  the  two  guide  pulleys  r  is  adjustable.  A  bar  r  2  placed  along-side  of  the  holder 
prevents  \\%  turning  round,  but  allows  it  to  slide  along  p'  by  friction.  The  weight  of  the 
holder  and  the  pulley  is  sufficient  to  distend  the  endless  band  n',  which  runs  from  the 
cone  fe ,  ihrou-h  under  the  pulley  /',  and  round  the  small  drum  m'  on  the  shaft  «2  A 
pulley  or  whorl  t%  with  four  grooves,  is  made  fast  by  means  of  a  tube  to  this  shaft'  and 
slides  along  it  backwards  and  forwards,  without  ever  ceasing  to  follow  its  revolutions. 
lh€  Shalt  possesses  for  this  purpose  a  long  fork,  and  the  interior  of  the  tube  a  corre- 
sponuing  tongue  or  catch.  There  is  besides  upon  the  tube  beneath  the  pulley,  at  tn,  a 
groove  that  goes  round  it,  m  which  the  staple  or  forked  end  of  an  arm  like  rfl,  fie.  410. 
made  fast  to  the  copp.ng  beam  p,  catches.  By  the  up  and  down  movement  of  that 
beam,  the  pulley  1 2  takes  along  with  it  the  arm  that  embraces  the  tube,  which  therefore 
rises  and  falls  equally  with  the  bobbins  h',  and  their  pulleys  or  whorls  a.  This  is 
requisite,  smce  the  bobbms  are  made  to  revolve  by  the  pulleys  1 2,  by  means  of  two  endless 
cords  or  bands.  '    '  ^-^ui^^m 

«rTi^^i?S-  ^"^."^^^^  y^'\f  the  mechanism  is  the  adjustment,  by  which  the  revolution 
of  the  bobbins  is  continualy  retarded,  and  their  up  and  down,  or  copping  motion,  along 
he  spindles,  IS  also  retarded  in  like  proportion.  The  vertical  pulley  /'  (towards  the 
left  end  of  the  shaft  c)  has  at  its  right  side  a  somewhat  larger  disc  or  sheave  g-, 
with  a  perfect  y  uniform,  but  not  a  very  smooth  surface.  Upon  this  sheave,  a  smaller 
horizontal  pulley  x  rubs,  whose  upper  face  is  covered  with  leather  to  increase  the  friction 
The  under  end  of  the  shaft  y%  of  the  pulley  x^  turns  in  a  step,  which  is  so  connected  with 
tte  arm  t,  of  the  large  bent  lever  /'  r',  that  it  always  stands  horizontally,  whatever 
direction  the  arms  of  that  lever  may  assume.    The  shaft  yi  is  steadied  at  top  by  aa 


annular  holder  or  bush,  which  embraces  the  fast  arm  xZ  with  its  forked  end.  Upon  iU 
opposite  side,  this  arm  carries  a  pulley  y2,  upon  which  a  cord  goes,  that  is  made  fast  to 
the  holder  of  the  shaft  y\  and  loaded  with  the  weight  z\  The  weight  presses  the 
pulley  x'  against  the  surface  of  g',  in  such  wise  as  to  effect  the  degree  of  friction  necessary 
in  order  that  the  revolution  of  g^  may  produce  an  uninterrupted  revolution  in  x'.  ^  A 
pinion  u'',  whose  length  must  be  equal  at  least  to  the  semi-diameter  of  the  sheave  g',  is 
placed  upon  the  under  end  of  the  shaft  yi.  It  has  22  teeth,  and  takes  into  a  62-toothed 
horizontal  wheel  z2.  Upon  the  upper  end  of  this  wheel  the  conical  pinion  a3  is  made 
fast  which  may  be  changed  for  changing  the  speed,  but  usually  has  from  28  to  30  teeth. 
By  this  pinion  the  conical  wheel  63  is  turned,  which  has  30  teeth,  and  whose  shaft  is  c3. 
This  shaft  carries  upon  its  opposite  end  a  six-leaved  pinion,  d3,  which  takes  into  the 
calender  wheel  /3,  formed  with  cogs  like  a  trundle,  upon  the  long  shaft  e3.  In  fig,  411 
the  wheel  p  is  exhibited  with  its  pinion  ds.  Here  we  may  remark,  that  in  the  circum- 
ference of  the  wheel  there  is  a  vacant  place,  ^3,  void  of  teeth.  When,  by  the  motion  of 
the  wheel,  the  pinion  comes  opposite  to  this  opening,  it  turns  round  about  the  last  tooth 
of  the  wheel,  falls  into  the  inside  of  the  toothed  circle  innrked  by  the  dotted  lines,  and 
thus  gives  now  an  inverse  movement  to  the  wheel  /3,  while  itself  revolves  always  in  the 
tame  direction.    This  reversed  motion  continues  tiU  the  opening  g3  comes  once  more 


CE 


412 

1— ^ 


K 


\5h. 


opposite  to  the  pinion,  when  this  turns  round  about  the  last  tooth  of  that  side,  and  begins 
again  to  work  in  the  exterior  teeth.  Thus,  by  the  uniform  motion  of  ds  and  its 
dependant  parts,  the  wheel  p,  with  its  shaft  e3,  revolves  alternately  to  the  right  hand 
and  the  left.  That  this  result  may  ensue,  the  shaft  c3  of  the  pinion  must  be  able  to 
slide  endwise,  without  losing  its  hold  of  a3  and  63.  This  adjustment  is  effected  by 
placing  the  end  of  the  said  shaft,  nearest  63,  in  a  box  or  holder  t3,  in  which  it  can  turn, 
and  which  forms  a  vertical  tube  to  this  box,  as  a  downward  prolongation  which  is  fixed 
to  the  tail  of  the  conical  pinion  a\  Fig,  412  shows  this  construction  in  section  upon 
an  enlarged  scale.  The  second  bearer  of  the  shaft  nearest  rf3,  must  possess  likewise  the 
means  of  lateral  motion.  When  therefore  the  pinion  d3  shifts  through  the  opening 
of  the  wheel  /3  outwards  or  inwards,  its  shaft  c3,  makes  a  corresponding  small  angular 
motion  upon  the  pivot  of  a3,  by  means  of  the  tube  i3 ;  a3  and  63  remain  thereby  com- 
pletely in  gear  with  one  another. 

The  above-described  alternate  revolutions  of  the  wheel  /3  serve  to  produce  the  up 
and  down  motions  of  the  bobbins.  The  shaft  63  has  for  this  purp^/Se  two  pinions  n*  n«, 
-which  work  in  the  rack  teeth  m^  ms  of  the  copping  rail  p,  and  thus  alternately  raise  and 
sink  it  with  the  bobbins  which  rest  upon  it.  The  weight  of  the  copping  beam  and  all 
its  dependant  parts,  is  poised  by  two  counterweights  m*,  whose  cords  run  over  the 
pulleys  04  04  04,  fig,  405,  and  have  their  ends  made  fast  to  the  frame,  so  as  to  make  the 
upward  motion  as  easy  as  the  downward.  The  two  upper  pulleys  out  of  the  three  of 
each  weight  are  fixed  to  the  frame;  the  under  one,  round  which  the  cord  first  runs,  is 
attached  to  the  cooping  beam,  rising  and  falling  along  with  it. 

As  long  as  the  friction  disc  x'  remains  at  the  same  height,  the  pulley  g'  derives  its 
motion  from  the  same  circle  of  the  said  disc,  and  the  up  and  down  motion  of  the  copping 
beam  is  also  uniform.  But  when  that  disc  ascends  so  as  to  describe  with  its  edge  a  small 
circle  upon  the  face  of  g',  its  motion  must  become  proportionally  more  slow.  This  is  the 
method,  or  principle  of  retarding  the  copping  motions  of  the  bobbins.  It  has  been  shown, 
however,  that  the  rotation  of  the  bobbins  should  be  also  retarded  in  a  progressive  manner. 
This  object  is  effected  by  means  of  the  cone  k',  which,  as  the  band  n  progressively 
approaches  towards  its  smaller  diameter,  drives  the  pulleys  or  whorls  q  of  the  bobbins 
with  decreasing  speed,  though  itself  moves  uniformly  quick  with  the  shaft  c.  To  effect 
this  variation,  the  cone  is  shifted  lengthwise  along  its  shaft,  while  the  band  running 
upon  it  remains  continually  in  the  same  vertical  plane,  and  is  kept  distended  by  the 
weight  of  the  pulley  0'.  The  following  mechanism  serves  to  shift  the  cone,  which  may 
be  best  understood  by  the  aid  of  the  figures  413, 414,  and  410.    A  long  cast  iron  bar  in*. 


522 


COTTON  MANUFACTURE. 


If 


which  hears  two  horizontal  projecting  poppets,  o3o3,  is  made  fast  to  the  front  nprigh 
face  of  the  copping  beam  a.    Through  the  above  puppets  a  cylindrical  rod  n3  passes  freely 

413 


<*!*#' 


i 


rfr-t^ 


^         ^^O^ 


^ 


m 


& 


which  is  left  out  in  Jig.  410,  that  the  parts  lying  behind  it  may  he  better  seen.    Upon 

this  rod  there  is  a  kmd  of  fork,  p3p3,  to  which  the  alternating  rack  bars  o3  are  made 

fast.     The  teeth  of  these  racks  are  at  unequal  distances  from  each  other,  and  are  so 

arranged,  that  each  tooth  of  the  under  side  corresponds  to  the  space  between  two  teeth 

m  the  upper  side.    Their  number  depends  upon  the  number  of  coils  of  roving  that  may 

be  required  to  fill  a  bobbin  ;  and  consists  in  the  usual  machines  of  from  20  to  22     The 

rod  «3  may  be  shifted  in  the  puppet  o3,  like  the  fork  p3  of  the  rack-rod,  upon  the  rod 

n3,  and  along  the  surface  of  ws,  where  two  wings  tt3  ^3  are  placed,  to  keep  the  fork  in 

a  straight  direction.     Upon  the  bar  tn3,  there  are  the  pivots  or  fulcra  of  two  stop  catches 

w3  a;3,  of  which  the  uppermost  presses  merely  by  its  own  weight,  but  the  undermost  by 

means  of  a  counterweight  y3,  against  the  rack,  and  causes  them  thus  to  faU  in  between 

the  teeth.      In  fig.   414,  v^  shows  the  pivot  of  the  catch  or  detent  w;3  by  itself,  the 

detent  itself  being  omitted,  to  render  the  construction  plainer.    A  pushing  rod  /3,  upon 

which  there  is  a  pin  above  at  53,  that  passes  behind  the  rack  rod,  between  this  and 

the  bar  m^,  has  for  its  object  to  remove  at  pleasure  the  one  or  the  other  of  the  two 

catches;  the  upper,  when  the  upper  end  of  the  rod  pushes  against  it;  the  under,  by 

means  of  the  above  mentioned  pin  s3.     Both  the  catches  are  never  raised  at  once,  but 

either  the  under  or  the  upper  holds  the  rack  bar  fast,  by  pressing  against  one  of  the 

teeth.    The  vertical  motion  up  or  down,  which  the  rod  Is  must  take  to  effect  the  lifting 

of  the  catches,  is  given  to  it  from  the  copping  beam  p ;  since  upon  it  a  horizontal  arm 

r«,  fig.  414,  is  fixed,  that  lays  hold  of  that  rod.     Upon  the  pushing  rod  are  two  rings 

A3  and  fcs,  each  made  fast  by  a  screw.     When  the  copping  beam  is  in  the  act  of  going 

up,  the  arm  v3  at  the  end  of  this  movement,  pushes  against  the  ring  A3,  raises  up  the 

rod  Z3,  and   thus  removes  the  catch  w3,  fig.  4J0,  from  the  teeth  of  the  rod  93,  before 

which  It  lies  flat.     At  the  descent  of  the  coppin?  rail,  t?2  meets  the  ring  fea,  when  the 

motion  in  this  direction  is  nearly  completed,  draws  down  the  rod  /a  a  little,  by  means  of 

the  same,  and  thereby  effects  the  removal  of  the  catch  z3,  fig.  414,  from  the  rod  qa. 

Every  iirae  that  one  of  the  catches  is  lifted,  the  rack  recovers  its  freedom  to  advance  a 

lilUe  bit  in  the  direction  of  the  arrow;  so  far,  namely,  till  the  other  catch  lavs  hold  upon 

the  tooth  that  next  meets  it.     The  reason  is  thus  manifest  why  the  teeth  of  the  upper 

and  under  sides  of  the  bar  53  are  not  right  opposite  to  each  other,  but  in  an  alternate 

position.  ' 

From  the  rack-bar,  the  sliding  of  the  cone  fc',  and  the  raising  of  the  shaft  yi,  each  by 
minute  steps  at  a  time,  is  produced  as  follows :  — 

A  large  rectangular  lever  /i,  t;»,  whose  centre  of  motion  is  at  pi,  has  at  the  upper  end 
?i-/^ll?."?  *''™.  '  ^,'°"^  ^^^^  through  which  a  stud  r3  upon  the  rack  q3  goes,  (figs.  413, 
414,  410,)  so  that  the  lever  must  follow  the  motions  of  the  rack  bar.  The  end  of  the 
short  arm  of  the  lever  bears,  as  already  mentioned,  the  step  of  the  shaft  y2;  hence  the 
friction  disc  x'  will  be  raised  in  proportion  as  the  rack  bar  advances,  and  wiU  come 
nearer  to  the  middle  point  of  gi ;  consequently,  its  revolution  and  the  shifting  of  the 
bobbins  will  become  slower.  Upon  the  cylindrical  rod  n3,  the  piece  «>  «»  furnished 
with  a  long  slot  is  made  fast,  by  means  of  a  tube  jl,  (fig.  410,)  and  a  screw.  A  fork 
«  u,  which  by  means  of  the  screw  nut  a*  is  made  fast  in  the  slot,  embraces  the  arm  /»  of 
the  beut  lever ;  and  a  tube  n  riveted  to  the  surface  of  ji,  is  destined  to  take  up  the  draw 
rod  qi  of  the  cone  k^.fig.  410.  A  weight  /«,  whose  cord  64  is  made  fast  to  the  cylindri- 
cal  rod  7i3,  endeavors  to  draw  this  rod  continually  in  the  direction  of  the  arrow.  In 
consequence  of  this  arrangement,  every  time  that  the  pushing  bar  t3  lifts  up  one  of  the 
ealches,  the  cone  fc',  the  lever  a  »»,  and  by  it  the  rack  bar  qs,  are  set  in  motion.    It  it 


COTTON  MANUFACTURE. 


523 


obvious,  that  the  motion  of  the  eone  may  be  made  greater  or  less,  according  as  the  fork 
tt  1*  is  fixed  further  up  or  down  in  the  slot  of  sK  .     m 

The  number  of  the  teeth  upon  the  bar  q3  is  so  ordered,  that  the  bobbins  are  quite  full 
when  the  last  tooth  has  reached  the  catch  and  is  released  by  it.  The  rack  bar,  being 
restrained  by  nothing,  immediately  slides  onwards,  in  consequence  of  the  traction  of  the 
weight  /4,  and  brings  the  machine  to  repose  by  this  very  movement,  for  which  purpose 
the  following  construction  is  employed.  A  rectangular  lever  which  has  its  centre  of 
motion  in  gi  is  attached  to  the  side  face  of  the  beam  a,  and  has  at  the  end  of  its  hori- 
zontal arm  a  pulley  d*,  over  which  the  cord  b*  of  the  counterweight  /»  is  passed.  The 
end  of  the  perpendicular  arm  is  forked  and  embraces  the  long  and  thin  rod  k*,  to  whose 
opposite  end  the  fork  l<  is  made  fast.  Through  this  fork  the  band  which  puts  the  ma- 
chine in  motion  passes  down  to  the  pulley  a'.  With  the  bent  lever  another  rod  c4  is 
connected  at  h*y  which  lies  upon  the  puppet  e3  with  a  slot  at  e4,  and  hereby  keeps  the 
lever  g*  in  its  upright  position  notwithstanding  the  weight  fi.  In  the  moment  when,  as 
above  stated,  the  rack  bar  53  becomes  free,  the  arm  p3  of  its  fork  pushes  in  its  rapid 
advance  against  the  under  oblique  side  of  €4,  raises  this  rod,  and  thereby  sets  the  lever  g* 
free  whose  upright  arm  bends  down  by  the  traction  of  the  weight,  drives  the  rod  k* 
before  it  into  the  ring  i*  fastened  to  it,  and  thus,  by  means  of  the  fork  Z4,  shifts  the  band 
apon  the  loose  pulley  &*.  But  the  machine  may  be  brought  to  repose  or  put  out  of  gear 
at  any  time  merely  by  shifting  the  rod  ki  with  the  hand. 

The  operation  of  the  bobbin  and  fly  frame  may  be  fully  understood  from  the  preceding 
description.  A  few  observations  remain  to  be  made  upon  the  cone  fei,  the  rack-bar  93, 
and  the  speed  of  the  work. 

When  we  know  the  diameter  of  the  empty  bobbins,  and  how  many  turns  they  should 
make  in  a  given  time  in  order  to  wind-on  the  sliver  delivered  by  the  fluted  rollers  and  the 
spindles ;  when  we  consider  the  diameters  of  the  spindle  pulleys  9,  and  t%  as  also  the 
drum  m\,fig.  405,  we  may  easily  find  the  diameter  which  the  cone  must  have  for  pro- 
ducing that  number  of  turns.  This  is  the  diameter  for  the  greatest  periphery  of  the 
base.  The  diameter  of  the  smaller  is  obtained  in  the  same  way,  when  the  diameter  of 
the  bobbins  before  the  last  winding-on,  as  well  as  the  number  of  turns  necessary  in  a 
given  time,  are  known. 

A  bobbin  and  fly  frame  of  the  construction  just  described  delivers  from  each  spindle 
in  a  day  of  twelve  hours,  from  6  to  8  lbs.  of  roving  of  the  fineness  of  1|  English  counts. 
One  person  can  superintend  two  frames,  piece  the  broken  slivers,  and  replace  the  fuU 
bobbins  by  empty  ones.  The  loss  of  cotton  wool  in  this  machine  consists  in  the  portions 
carried  off  from  the  torn  slivers,  and  must  be  returned  to  the  lapping  machine. 

The  fiivt  bobbin  and  fly  frame  does  not  differ  essentially  from  the  preceding  machine. 
The  rovings  from  the  coarse  bobbin  and  fly  frame  are  placed  in  their  bobbins  in  a  frame 
called  the  creel,  behind  and  above  the  roller  beam,  two  bobbins  being  allowed  for  one 
fluted  portion  of  the  rollers.  These  rovings  are  united  into  one,  so  as  to  increase  the 
uniformity  of  the  slivers. 

The  invention  of  the  beautiful  machine  above  described  is  due  to  Messrs.  Cocker  and 
Higgins,  of  Manchester,  and  as  lately  improved  by  Henry  Houldsworth,  jun.,  Esq.,  it 
may  be  considered  the  most  ingeniously  combined  apparatus  in  the  whole  range  of  pro- 
ductive industry. 

In  the  fine  roving  frame  the  sliver  is  twisted  in  the  contrary  direction  to  that  of  the 
coarse  roving  frame.  For  this  reason  the  position  of  the  cone  is  reversed,  so  as  to  pre- 
sent in  succession  to  the  band,  or  strap,  diameters  continually  greater,  in  order  that  the 
rotation  of  the  bobbins  may  be  accelerated  in  proportion  as  their  size  is  increased, 
because  here  the  flier  and  the  bobbin  turn  in  the  same  direction,  and  the  winding-on 
is  eflfected  by  the  precession  of  the  bobbin ;  but  if  the  winding-on  took  place  by  its  falling 
behind,  as  in  the  coarse  bobbin  and  fly  frame,  that  is,  if  the  flier  turned  less  quickly  than 
the  bobbin,  the  rotatory  speed  of  the  bobbin  would  be  uniformly  retarded ;  in  which  case 
the  cone  would  be  disposed  as  in  the  coarse  frame. 

When,  by  any  means  whatever,  a  uniform  length  of  thread  is  delivered  by  the  rollers 
in  a  given  time,  the  bobbin  must  wind  it  up  as  it  is  given  out,  and  must  therefore  turn 
with  a  speed  decreasing  with  the  increase  of  its  diameter  by  successive  layers  of  thread. 
Hence  proceeds  the  proposition,  that  the  velocity  of  the  bobbin  must  be  in  the  inverse 
ratio  of  its  diameter,  as  already  explained. 

With  respect  to  the  bobbin  and  fly  frame,  the  twist  is  given  to  the  sliver  by 
means  of  a  spindle,  or  flier,  which  turns  in  the  same  direction  with  the  bobbin,  but 
qnicker  or  slower  than  it,  which  establishes  two  predicaments.  The  first  case  is  where 
the  flier  turns  faster  than  the  bobbin.  Here  the  winding-on  goes  in  advance,  as  in 
the  coarse  roving  frame,  or  as  in  throstle  spinning,  where  the  yarn  is  wound  on  merely 
in  consequence  of  the  friction  of  the  lower  disc  or  washer  of  the  bobbin  upon  the 
copping  rail,  and  of  the  drag  of  the  yam.  The  second  case  is  where  the  flier  revolves 
more  slowly  than  the  bobbin.    Here  the  winding  goes  on  in  arrear,  and  as  the  bobbin 


If 


524 


COTTON  MANUFACTURE. 


COTTON  MANUFACTURE. 


525 


twns  faster,  it  must  receive  a  peculiar  motion,  which  is  uniformly  retarded  in  the  ratie 
01  Its  increase  of  diameter.  This  is  the  case  with  the  fine  bobbin  and  fly  frame  When 
the  cone  is  placdl  as  in  Jig  405,  the  winding-on,  in  either  the  coarse  or  fine  frame,  re- 
sults from  the  difference,  whether  greater  or  less,  between  the  rotatory  soeed  of  the  flier 
and  bobbin.  j     h    u  «i  mc  iuc» 

The  motion  of  the  bobbin  and  spindle  is  simultaneous,  and  takes  place  in  the  same 

direction,  with  a  difference  varying  more  or  less  with   the  varying  diameters  of  the 

bobbins.    To  render  the  matter  still  clearer,  suppose  for  a  moment  the  spindle  to  be 

motionless,  then  the  bobbin  must  revolve  with  such  a  speed  as  to  lap-on  the  rovinc  as 

.  fast  as  the  rollers  deliver  it.     The  sliver  comes  forward  uniformly ;  but  the  bobbin  bv 

Its  increase  of  diameter,  must  revolve  with  a  speed  progressively  slower.     Now    mZ 

pose  the  spindle  set  a-whirUng,  it  is  obvious  that  the  bobbin  must  add  to  the  movement 

requisite  for  wmding-on   the  sliver,  that  of  the  spindle  in  the  case  of  winding-on  in 

arrear,  or  when  it  follows  the  fliers,  and    subtract  its  own  motion  from  the  twisting 

motion  of  the  spindles,  in  the  case  of  winding-on  in  advance,  that  is,  when  the  bobbin 

precedes  or   turns  faster   than   the  fliers;    for  the  diameter  of  the  bobbin   bein-  Ih 

inches,  10  turns  will  lake  up  45  inches.    Deducting  these  10  turns  from  the  30  made 

by  the  spmdle  m  the  same  time,  there  will  remain  for  the  effective  movement  of  the 

^bbin  only  20  turns;  or  when  the  diameter  of  the  bobbin  becomes  3  inches,  5  turns 

will  take  up  the  45  inches,  if  the  spindle  be  at  rest;  but  if  it  makes  30  turns  in  the 

!?°'VKt-^^^'''J''fl  "'f'^'^^  f  ^^^  ^°^^^"  ^'^"  ^^  25  turns,  =  30-5.  Hence  in  the 
fine  bobbin  and  fly  frame,  the  number  of  turns  of  the  spindle,  minus  the  number  of 
turns  made  by  the  bobbin  in  equal  times,  is  in  the  inverse  ratio  of  the  diameter  of  the 
bobbin      We  thus  perceive,  that  in  the  coarse  frame  the  bobbin  should  move  faster 

1^1  KK- '^*!!  '^'^  ^""^  ^^^1-  "^  'P^^'^  '^°**^^  «l^*ys  <l'minish;  whilst  in  the  fine  frame 
the  bobbin  should  move  slower  than  the  spindle,  but  its  speed  should  always  increase. 
It  is  easy  to  conceive,  therefore,  why  the  cones  are  placed  in  reverse  directions  in  the 
two  machines.  Not  that  this  inversion  is  indispensably  necessary;  the  cone  of  the  fine 
roving  frame  miaht,  in  fact,  be  placed  like  that  of  the  coarse  roving  frame ;  but  as  the 
torsion  of  the  roving  becomes  now  considerable,  and  as  on  that  account  the  bobbin  would 
need  to  move  still  faster,  which  would  consume  a  greater  quantity  of  the  moving  power 
It  has  been  deemed  more  economical  to  give  its  movement  an  opposite  direction  ' 

We  mentioned  that  the  twist  of  the  sliver  in  the  fine  roving  frame  was  the  reverse  of 
that  in  the  coarse;  this  is  a  habit  of  the  spinners,  for  which  no  good  reason  has  been 

The  divisions  of  the  rack-bar,  and  the  successive  diameters  of  the  cone,  must  be 
mcely  adjusted  to  each  other.  The  first  thing  to  determine  is,  how  much  the  rack 
should  advance  for  every  layer  or  range  of  roving  applied  to  the  bobbin,  in  order  that 
the  cone  may  occupy  such  a  place  that  the  strap  which  regulates  the  pulley  barrel  mav 
be  at  the  proper  diameter,  and  thus  fulfil  every  condition.  The  extent  of  this  nro 
gressive  movement  of  the  rack  depends  upon  the  greater  or  less  taper  of  the  cone  and 
the  increase  which  the  diameter  of  the  bobbin  receives  with  every  traverse,  that  is  every 
layer  of  roving  laid  on.  But  care  sliould  be  taken  not  to  taper  the  cone  too  rapidlV  esoe- 
cially  m  the  fine  rovmg  frame,  because  in  its  progress  towards  the  smaller  end  the  strap 
would  not  slide  with  certainty  and  ease.  We  have  already  shown  that  the  number  of 
effective  turns  of  the  bobbin  is  inversely,  as  the  diameter  of  the  bobbin ;  or  directly  as 
the  successive  diameters  of  the  different  points  of  the  cone. 

H.  Houldsworth,  jun.  Esq.  has  introduced  a  capital  improvement  into  the  bobbin  and 
ny  !rame,by  his  differential  or  equation-box  mechanism,  and  by  his  spring  fingers,  which 
by  pressing  the  soft  sliver  upon  the  bobbin,  cause  at  least  a  double  quantity  to  be  wound 
opon  Its  barrel.    With  the  description  of  his  patent  equation-box,  I  shall  conclude  the 
description^ of  the  bobbin  and  fly  frame.  *"  ^  »  .  ""'-•"ue  me 

Fig.  415  represents  a  portion  of  a  fly  frame  with  Mr.  Houldsworth's  invention. 
-„^  t^'i  i  K  T  ^'^T"^  '■''"^'■''  ^"'■"'"S  "P°"  bearings  in  the  top  of  the  machine, 
actu^ed  ^  ^^  '^^'^^''  '"^  ^^^  ^""^  *^*'  ^*^^S  rollers  are  usually 

From  the  drawing  rollers,  the  filaments  of  cotton  or  other  material,  b  ft,  are  brought 
down  to  and  passed  through  the  arms  of  the  fliers  c  c,  mounted  oi  th^  t..ps  of  the 
spindles  d  rf,  which  spindles  also  carry  the  loose  bobbins  e  e.  In  the  ordinary  mode  of 
constructing  such  machines,  the  spindles  are  turned  by  cords  or  bands  passing  from  a 
rotatory  drum  round  their  respective  pulleys  or  whirls/,  and  the  loose  bobbins  «,  turn 
with  them  by  the  friction  of  their  slight  contact  to  the  spindle,  as  before  said ;  in  the 
improved  machine,  however,  the  movements  of  the  spindles  and  the  bobbins  ai^e  inde- 
pendent  and  distinct  from  each  other,  being  actuated  from  different  sources. 

The  mam  shaft  of  the  engine  g,  turned  by  a  band  and  rigger  a  as  usual,  communicates 
motion  by  a  train  of  wheels  A,  through  the  shaft  z,  to  the  drawing  rollers  at  the 
reverse  end  of  the  machine,  and  causes  them  to  deliver  the  filaments  to  be  twisted. 


Upon  the  main  shaft  g,  is  mounted  a  cylindrical  hollow  box  or  drum-pulley,  whence 
one  cord  passes  to  drive  the  whirls  and  spindles  /  and  d,  and  another  to  drive  the 
bobbins  e. 


This  cylindrical  box  pulley  is  made  in  two  parts,  fe  and  /,  and  slipped  upon  the  axle  with 
a  toothed  wheel  m,  intervening  between  them.  The  box  and  wheel  are  shown  detached 
in  fig.  416,  and  partly  in  section  at^g.  417.  That  portion  of  the  box  with  its  pulley 
marked  Z,  is  fixed  to  the  shaft  g ;  but  the  other  part  of  the  box  and  its  pulley  fe,  and  the 
toothed  wheel  m,  slide  loosely  round  upon  the  shaft  g,  and  when  brought  in  contact  and 
confined  by  a  fixed  collar  w,  as  in  the  machine  shown  at  fig.  415,  they  constitute  two 
distinct  pulleys,  one  being  intended  to  actuate  the  spindles,  and  the  other  the  bobbins. 

In  the  web  of  the  wheel  m,  a  small  bevel  pinion  o,  is  mounted  upon  an  axle  standing 
at  right  angles  to  the  shaft  g,  which  pinion  is  intended  to  take  into  the  two  bevel  pinions 
p  and  5,  respectively  fixed  upon  bosses,  embracing  the  shaft  in  the  interior  of  the  boxes  k 
and  L  Now  it  being  remembered  that  the  pinion  q,  and  its  box  Z,  are  fixed  to  the  shaft 
g,  and  turn  with  it,  if  the  loose  wheel  m  be  independently  turned  upon  the  shaft,  with  a 
different  velocity,  its  pinion  o,  taking  into  q,  will  be  made  to  revolve  upon  its  axle,  and 
to  drive  the  pinion  p,  and  pulley  box  /r,  in  the  same  direction  as  the  wheel  m  ;  and  this 
rotatory  movement  of  the  box  fc  and  wheel  m,  may  be  faster  or  slower  than  the  shaft  g 
and  box  /,  according  to  the  velocity  with  which  the  wheel  m  is  turned. 

Having  explained  the  construction  of  the  box  pulleys  k  and  /,  which  are  the  peculiar 
features  of  novelty  claimed  under  this  patent,  their  office  and  advantage  will  be  seen  by 
describing  the  general  movements  of  the  machine. 

The  main  shaft  g,  being  turned  by  the  band  and  rigger  a,  as  above  said,  the  train  of 
wheels  A,  connected  with  it,  drives  the  shaft  i,  which  at  its  reverse  end  has  a  pinion  (not 
seen  in  the  figure)  that  actuates  the  whole  series  of  drawing  rollers  a.  Upon  the  shaft 
t  there  is  a  sliding  pulley  r,  carrying  a  band  s,  which  passes  down  to  a  tension  pulley  / 
and  IS  kept  distended  by  a  weight.  This  band  s,  in  its  descent,  comes  in  contact  with 
the  surface  of  the  cone  «,  and  causes  the  cone  to  revolve  by  the  friction  of  the  band 
running  against  it.  The  pulley  r  is  progressively  slidden  along  the  shaft  i,  by  means  of 
a  rack  and  weight  not  shown,  but  well  understood  as  common  in  these  kind  of  machines, 
and  which  movement  of  the  pulley  is  for  the  purpose  of  progressively  shifting  the  band 
*  from  the  smaller  to  the  larger  diameter  of  the  cone,  in  order  that  the  speed  of  its 
rotation  may  gradually  dimmish  as  the  bobbins  fill  by  the  winding-on  of  the  yarns. 

At  the  end  of  the  axle  of  the  cone  u  a  small  pinion  v  is  fixed,  which  takes  into  the 
teeth  of  the  loose  wheel  m,  and,  as  the  cone  turns,  drives  the  wheel  m  round  upon  the 
shaft  g,  with  a  speed  dependant  always  upon  the  rapidity  of  the  rotation  of  the  cone. 
Now  the  box  pulley  /,  being  fixed  to  the  main  shaft  g,  turns  with  one  uniform  speed, 
•nd  by  cords  passing  from  it  over  guides  to  the  whorls  /,  drives  all  the  spindles  and 
lliers,  which  twist  the  yarns  with  one  continued  uniform  velocity ;  but  the  box  pulley  k 


526 


COTTON  MANUFACTURE. 


COTTON  MANUFACTURE. 


527 


beins:  loose  npon  the  shaft,  and  actuated  by  the  bevel  pinions  within,  as  described,  is 
made  to  revolve  by  the  rotation  of  the  wheel  m,  independent  of  the  shaft,  and  with  a 
different  speed  from  the  pulley  box  / ;  cords  passing  from  this  pulley  box  fr,  over  guides 
to  small  pulleys  under  the  bobbins,  communicate  the  motion,  whatever  it  may  be,  of  the 
pulley  box  k,  to  the  bobbins,  and  cause  them  to  turn,  and  to  take  up  or  wind  the  yarn 
with  a  speed  derived  from  this  source,  independent  of,  and  different  from,  the  speed  of 
the  spindle  and  flier  which  twist  the  yarn. 

It  will  now  be  perceived,  that  these  parts  being  all  adjusted  to  accommodate  the 
taking  up  movements  to  the  twisting  or  spinning  of  any  particular  quality  of  yam 
intended  to  be  produced,  any  variations  between  the  velocities  of  the  spinning  and 
taking  up,  which  another  quality  of  yarn  may  require,  can  easily  be  effected,  by  merely 
changing  the  pinion  r,  for  one  with  a  different  number  of  teeth,  which  will  cause  the 
wheel  m,  and  the  pulley  box  fr,  to  drive  the  bobbins  faster  or  slower,  as  would  be  required 
in  winding-on  fine  or  coarse  yarn,  the  speed  of  the  twisting  or  spinning  jeing  the 
same. 

The  rovings  or  spongy  cords,  of  greater  or  less  tenuity,  made  on  the  bobbin  and  fly, 
or  tube  roving  frame,  are  either  spun  immediately  into  firm  cohesive  yarn,  or  receive  a 
further  preparation  process  in  the  stretching  frame,  which  is,  in  fact,  merely  a  mule- 
jenny,  without  the  second  draught  and  second  speed,  and  therefore  need  not  be  described 
at  present,  as  it  will  be  in  its  place  afterwards. 

The  finishing  machines  of  a  cotton  mill,  which  spin  the  cohesive  yarn,  are  of  two 
classes ;  1.  the  water-twist  or  throstle,  in  which  the  twisting  and  winding  are  performed 
simultaneously  upon  progressive  portions  of  the  roving;  and,  2.  the  mule,  in  which  the 
thread  is  drawn  out  and  stretched,  with  little  twist,  till  a  certain  length  of  about  5  feet 
is  extended,  then  the  torsion  is  completed,  and  the  finished  thread  is  immediately  wound 
upon  the  spindles  into  double  conical  coils  called  cops. 

The  water-twist  frame,  so  called  by  its  inventor.  Sir  R.  Arkwright,  because  it  was  first 
driven  by  water,  is  now  generally  superseded  by  the  throstle  frame,  in  which  the  me- 
chanical spinning  fingers,  so  to  speak,  are  essentially  the  same,  but  the  mode  of  commu- 
nicating the  motion  of  the  mill-gearing  to  them  is  somewhat  different.  Fig.  418  exhibits 
a  vertical  section  of  the  throstle.  This  machine  is  double,  possessing  upon  each  side  of 
its  frame  a  row  of  spindles  with  all  their  subsidiary  parts.  The  bobbins,  filled  with 
rovings  from  the  bobbin  and  fly,  or  the  lube  frame,  are  set  up  in  the  creel  a  a,  in  two 
ranges.  6,  c,  rf,  are  the  three  usual  pairs  of  drawing  rollers,  through  which  the  yarn 
is  attenuated  to  the  proper  degree  of  fineness,  upon  the  principles  already  explained. 
At  its  escape  from  the  front  rollers,  every  thread  runs  through  a  guide  eyelet  e  of  wire, 
which  gives  it  the  vertical  direction  down  towards  the  spindles/,  g.  The  spindles  which 
perform  at  once  and  uninterruptedly  the  twisting  and  winding-on  of  the  thread  delivered 
by  the  rollers,  are  usually  made  of  steel,  and  tempered  at  their  lower  ends.  They  stand 
at  g  in  steps,  pass  at  v  through  a  brass  bush  or  collet  which  keeps  them  upright,  and 
revolve  with  remarkable  speed  upon  their  axes.  The  bobbins  hj  destined  to  take  up  the 
yarn  as  it  is  spun,  are  stuck  loosely  upon  the  spindles,  and  rest  independently  of  the 
fetation  of  the  spindles  upon  the  copping  beam  /,  with  a  leather  washer  between.  Upon 
the  top  of  the  spindles  an  iron-wire  fork,  called  a  fly  or  flier,  t,  Ar,  is  made  fast  by  a 
left-hand  screw,  and  has  one  of  its  forks  turned  round  at  the  end  into  a  little  ring. 
The  branch  of  the  flier  at  /  is  tubular,  to  allow  the  thread  to  pass  through,  and  to 
escape  by  a  little  hole  at  its  side,  in  order  to  reach  the  eyelet  at  the  end  of  that  fork. 
From  this  eyelet  i,  it  proceeds  directly  to  the  bobbin.  By  the  twirling  of  the  spindle, 
the  twisting  of  the  portion  of  thread  between  the  front  roller  d  and  the  nozzle  /  is 
effected.  The  winding-on  takes  place  in  the  following  way: — Since  the  bobbin  has  no 
other  connexion  with  the  spindle  than  that  of  the  thread,  it  would,  but  for  it,  remain 
entirely  motionless,  relatively  to  the  spindle.  But  the  bobbin  is  pulled  after  it  by  the 
thread,  so  that  it  must  follow  the  rotation  of  the  spindle  and  fly.  When  we  consider 
that  the  thread  is  pinched  by  the  front  roller  rf,  and  is  thereby  kept  fully  upon  the 
stretch,  we  perceive  that  the  rotation  of  the  bobbin  must  be  the  result.  Suppose  now 
the  tension  to  be  suspended  for  an  instant,  while  the  rollers  d  deliver,  for  example,  one 
inch  of  yarn.  The  inertia  or  weight  of  the  bobbin,  and  its  friction  upon  the  copping 
beam  l^  by  means  of  the  leather  washer,  will,  under  this  circumstance,  cause  the  bobbin 
to  hang  back  in  a  state  of  rest,  till  the  said  inch  of  yarn  be  wound  on  by  the  whirling 
of  the  fly  I,  and  the  former  tension  be  restored.  The  delivery  of  the  yarn  by  the  drawing 
rollers,  however,  does  not  take  place  inch  after  inch,  by  starts,  but  at  a  certain  continu- 
ous rate ;  from  whence  results  a  continuous  retardation  or  loitering,  so  to  speak,  of  the 
bobbins  behind  the  spindles,  just  to  such  an  amount  that  the  delivered  yam  is  wound  up 
at  the  same  time  during  the  rotation. 

This  process  in  spinning  is  essentially  the  same  as  what  occurs  in  the  fine  bobbin 
and  fly  frame,  but  is  here  simplified,  as  the  retardation  regulates  itself  according  to 
the  diameter  of  the  bobbin  by  the  drag  of  the  thread.    In  the  fly  frame  the  employmen. 


<f  this  itAJim  is  impossible,  because  the  roving  has  too  little  cohesion  to  bear  the  strain; 
and  henoe  it  is  necessary  to  give  the  bobbins  that  independent  movement  of  rotation 
which  so  complicates  this  machine. 

The  up  and  down  motion  of  the  bobbins  along  the  spindles,  which  is  required  for 
the  equal  distribution  of  the  yarn,  and  must  have  the  same  range  as  the  length  of  the 
bobbin  barrels,  is  performed  by  the  following  mechaninn.  Every  copping  rail,  /,  is 
made  fast  to  a  bar  m,  and  this,  which  slides  in  a  vertical  groove  or  slot  at  the  end  of 
the  frame,  is  connected  by  a  rod  n,  with  an  equal-armed,  moveable  lever  o.  The  rod  p 
carries  a  weight  r,  suspended  from  this  lever ;  another  rod,  g,  connects  the  great  lever  o 
with  a  smaller  one  »,  t,  upon  which  a  heart-shaped  disc  or  pulley,  »,  works  from  below 
at  t.  By  the  rotation  of  the  disc  «,  the  arm  t,  being  pressed  constantly  down  upon  it  by 
the  reaction,  the  weight  r  must  alternately  rise  and  fall ;  and  thus  the  copnine  rail  I  must 
obviously  move  with  the  bobbins  h  up  and  down ;  the  bobbins  upon  one  side  of  the  frame 
rising,  as  those  upon  the  other  sink.  Strictly  considered,  this  copping  motion  should 
become  slower  as  the  winding-on  proceeds,  as  in  the  fly  roving  frame ;  but,  on  account 
of  the  smallness  of  the  finished  thread,  this  construction,  which  would  render  the 
machine  complicated,  is  without  inconvenience  neglected,  with  the  result  merely  that  the 
coils  of  the  yarn  are  successively  more  sparsely  laid  on,  as  the  diameter  of  the  bobbin 
increases. 

The  movement  of  the  whole  machine  proceeds  from  the  shaft  of  a  horizontal  dnun, 
which  drives  the  spindles  by  means  of  the  endless  bands  x  x.  Each  spindle  is  mounted 
with  a  small  pulley  or  wharf,  w,  at  its  lower  part,  and  a  particular  band,  which  goes 
round  that  wharf  or  whorl,  and  the  dmm  y.  The  bands  are  not  drawn  tense,  but  hang 
down  in  a  somewhat  slanting  direction,  being  kept  distended  only  by  their  own  weight. 
Thus  every  spindle,  when  its  thread  breaks,  can  readily  be  stopped  alone,  by  applying  a 
slight  pressure  with  the  hand  or  knee,  the  band  meanwhile  gliding  loosely  round  the  whorL 
The  velocities  of  rotation  of  the  three  drawing  rollers  are,  according  to  this  arrange^ 
ment,  in  the  proportion  of  1  :  1^  :  8 ;  and  as  their  diameters  are  the  same,  namely,  one 
inch,  the  elongation  of  the  yam  in  spinning  is  eight-fold.  If,  for  example,  the  roving 
was  of  the  number  4|,  the  yarn  would  become  No.  36.  The  extension  of  the  thread 
may  be  changed  by  changing  the  wheels  of  the  drawing  rollers.  To  perceive  the  power 
of  this  change,  let  us  put,  for  example,  in  the  place  of  the  18-toothed  wheel  of  the  back 
rollers,  a  wheel  with  16  teeth ;  we  shall  find  that  the  elongation  will  amount,  in  that 
case,  only  to  7J  times,  whence  the  number  of  the  yarn  would  come  out  32  =  7^  X  4|. 
The  extension  by  the  throstle  is  extremely  various :  it  amounts,  in  some  cases,  to  only  4 
Umes ;  at  others  to  10,  12,  or  even  15. 

The  copping  motion  of  the  bobbins  is  produced  in  consequence  of  a  bevel  pinion  work- 
ing in  a  small  bevel  wheel  upon  an  upright  shaft;  while  this  wheel  gives  a  slow  motion 
fcy  means  of  a  worm  screw  to  the  wheel  of  the  heart-shaped  pulley  u,fig.  418. 

The  driving  pulley  makes  about  600 
turns  in  a  minute ;  and  as  the  diameter  of 
the  drum  y,  fig.  418,  is  six  times  the  di- 
ameter of  the  spindle  wharves  to,  it  will 
give  3600  turns  to  the  spindle  in  that  time. 
If  the  pulley  be  driven  faster,  for  example, 
700  times  in  a  minute,  it  will  increase  the 
revolutions  of  the  spindles  to  4200.  The 
degree  of  twist  which  will  be  thereby  im- 
parted to  the  yarn,  depends,  with  like  speed 
of  spindles,  upon  the  rate  at  which  the  soft 
yarn  is  delivered  by  the  drawing- rollers ; 
for  the  quicker  this  delivery  the  quicker  is 
the  winding-on,  and  the  less  twist  goes  into 
a  given  length  of  yarn.  If,  for  example, 
the  front  rollers  d  turn  24  times  in  a 
minute,  giving  out  of  course  72  inches  of 
yarn  in  this  time,  upon  which  the  3600 
revolutions  of  the  spindle  are 'expended, 
there  will  be  50  twists  to  every  inch  of 
-       ,^       ,        ...  yarn.    By  changing  the  wheel- work  of 

Jig.  418,  or  by  sticking  greater  or  smaller  wharves  upon  the  spindles,  the  proportion  be- 
tween their  velocity  and  that  of  the  drawing  rollers,  and  thence  the  degree  of  twist,  can 
be  modified  at  pleasure. 

The  number  of  spindles  in  a  throstle  frame  12  feet  long  is  about  60  on  each  side. 
The  drawing  rollers  are  coupled  together  as  in  the  bobbin  and  fly  frame,  so  that  each 
row  forms  one  continuous  cylinder.  There  is  a  complete  roller  beam  on  each  side-; 
each  of  the  rollers  of  the  front  row  is  pressed  bv  its  top  rollers  with  a  weight  of  ten 

34 


418 


CJOXTON  MANUFACTURE. 

twelve  pounds ;  but  those  of  the  middle  and  back  rows  bear  weights  of  only  one  pound. 
In  the  throstles,  there  is  a  guide  bar  which  traverses  a  small  way  horizontally  to  the  left 
and  right,  in  front  of  the  roller  beam,  to  lead  the  thread  along  different  points  of  the 
rollers,  and  thus  prevent  the  leather  of  the  top  ones  from  being  grooved  by  its  constant 
pressure  in  one  line. 

For  the  service  of  240  spindles,  in  two  double  frames,  one  young  woman  and  an  assist- 
ant piecer  are  sufficient.  They  mend  the  broken  ends,  and  replace  the  empty  bobbins 
in  the  creel  with  full  ones,  and  the  full  bobbins  of  the  throstle  by  empty  ones.  The 
average  quantity  of  yarn  turned  ofi'  in  a  week  of  69  hoiirs  i«  about  24  hanks  per  spindle 
of  30's  twist.  Throstle  yarn  is  of  a  firm  wiry  quality,  adapted  to  the  warps  of  fustians 
and  other  strong  stuffs,  as  well  as  to  the  manufacture  of  stockings  and  sewing  thread. 

There  are  many  modifications  of  the  throstle  system  besides  the  one  above  described ; 
the  most  celebrated  of  which  are  Danforth's,  called  the  American  throstle,  Montgomery's, 
and  Gore's.  I  must  refer  for  an  account  of  them  to  my  work  entitled  "  The  Cotton  Ma- 
nufacture of  Great  Britain,'*  where  they  are  minutely  described  and  illustrated  with 
accurate  figures.  < 

Mule-spinning. — The  general  principles  of  the  mule  have  been  already  stated.    This 
machine  is  so  named  because  it  is  the  offspring,  so  to  speak,  of  two  older  machines,  the 
jenny  and  the  water-frame.    A  mule  is  mounted  with  from  240  to  1000  spindles,  and 
pins,  of  course,  as  many  threads. 

Figi419  represents  the 

original   jenny    of   Har- 

4J9  W  ^    t  ~^^^  greaves,   by   which    one 

person  was  enabled  to 
spin  from  16  to  40  threads 
at  once.  The  soA  cords 
of  rovings  wound  in  dou- 
ble conical  cops  upon 
skewers  were  placed  in 
the  inclined  frame  at  c; 
the  spindles  for  first 
twisting  and  then  wind- 
ing-on  the  spun  yarn 
were  set  upright  in  steps 
and  bushes  at  a,  being 
furnished  near  their  lower 
ends  with  whorls,  and  endless  cords,  which  were  driven  by  passing  round  the  long- 
revolving  drum  of  tin  plate  e.  d  is  the  clasp  or  clove,  having  a  handle  for  liAing 
its  upper  jaw  a  little  way,  in  order  to  allow  a  few  inches  of  the  soft  roving  to  be 

introduced.  The  com- 
pound clove  D  being  now 
pushed  forward  upon  its 
friction  wheels  to  a,  was 
next  gradually  drawn 
backward,  while  the  spin- 
dles were  made  to  revolve 
with  proper  speed  by  the 
right  hand  of  the  opera- 
tive turning  the  fly-wheel 
B.  Whenever  one  stretch 
was  thereby  spun,  the 
clove  frame  was  slid 
home  towards  a;  the 
spindles  being  simulta- 
neously whirled  slowly 
to  take  up  the  yam, 
which  was  laid  on  in  a 
conical  cop  by  the  due 
depression  of  the  faller 
wire  at  a  with  the  spin- 
ner's leA  hand. 

Fig.  420  is  a  diagram 
of  Arkwright's  original 
water  ^  frame  spinning 
machine,  called  aAer< 
wards  the  water  -  twiti 


I 


COTTON  MANUFACTURE. 


529 


frame.  The  rovings  mounted  upon  bob- 
bins in  the  creel  a  a,  have  their  ends  led 
through  between  the  three  sets  of  twin 
rollers  below  b  b,  thence  down  through 
the  eyelet  hooks  upon  the  end  of  the  fliers 
of  the  spindles  c,  and  finally  attached  to 
their  bobbins.  The  spindles  being  driven 
by  the  band  d  d  upon  their  lower  part,  con- 
tinuously twist  and  wind  the  finished  yarn 
upon  the  bobbins;  constituting  the  first 
unremitting  automatic  machine,  for  spinning 
which  the  world  ever  saw. 

Contrast  with  the  above  admirable  sys- 
tem, the  primitive  cotton  wheel  of  India,  as 
represented  in  the  annexed  figure  421.  By 
the  aid  of  mechanical  fingers,  one  English- 
man at  his  mule  can  turn  off  daily  more 

,.     „•  j-r      »     .    .         ^  „.  J  y*^**  ^^^  °^  ^'^^  fi^er  quality  than  200  of 

tM  most  diligent  spinsters  of  Hmdostan. 

Fig.  422  is  a  transverse  section  of  the  mule,  in  which  its  principal  parts  arc  shown* 


The  machine  consists  of  two  main  parts ;  a  fixed  one  corresponding  in  some  moi- 
sure  to  the  water-frame  or  throstle,  and  a  moveable  one  corresponding  to  the  jenny. 
The  first  contains  m  a  suitable  frame  the  drawing  roller-beam  and  the  chief  movinjr 
machinery:  the  second  is  called  the  carriage,  in  which  the  remainder  of  the  moving 
mechanism  and  the  spmdles  are  mounted. 

The  fnime  of  the  fixed  part  consists  of  two  upright  sides,  and  two  or  more  intermediate 
parallel  bearings,  upon  which  the  horizontal  roller  beam  o,  the  basis  of  the  drawing  rollers 
is  supported.  6,  c,  d,  are  the  three  ranges  of  fluted  iron  rollers ;  e,/,  g,  are  the  upper  iron 
rollers  covered  with  leather;  A,  the  wooden  wiper-rollers  covered  with  flannel,  which 
being  occasionally  rubbed  with  chalk,  imparts  some  of  it  to  the  pressure  rollers  beneath, 
so  as  to  prevent  the  cotton  filaments  adhering  to  them.    The  rollers  are  made  through- 


530 


COTTON  MANUFACTURE. 


'I 


>ii 


!  I 


t 


ont  the  whole  length  of  the  male  in  portions  containing  six  flutings,  which  are  coupled 
together  by  squared  ends  fitted  into  square  holes. 

The  skewers  upon  which  the  bobbins  containing  the  rovings  from  the  bobbin  and  fly 
or  stretching  frame  are  set  up,  are  seen  at  ai,  ai,  a>,  arranged  in  three  rows  in  the 
creel  z.  The  soft  threads  unwound  from  these  bobbins,  in  their  way  to  the  drawing 
rollers,  pass  first  through  eyelets  in  the  ends  of  the  wire  arms  b\  then  through  the 
rings  or  eyes  of  the  guide  bar  w,  and  enter  between  the  back  pair  of  rollers.  Th€ 
lumber  of  these  bobbins  is  equal  to  the  number  of  spindles  in  the  mule,  and  twice  as 
f  real  as  the  number  of  fluted  portions  of  the  rollers ;  for  two  threads  are  assigned  to 
each  portion. 

The  carriage  consists  of  two  cast-iron  side  pieces,  and  several  cast-iron  intermediate 
similar  pieces,  such  as  /a,  which  all  together  are  made  fast  to  the  planks  62,  c«,  d».  The 
top  IS  covered  in  with  the  plank  ka.  The  carriage  runs  by  means  of  its  cast-iron  grooved 
wheels,  upon  the  cast-iron  railway  /2,  which  is  fixed  level  on  the  floor. 

The  spindles  stand  upon  the  carriage  in  a  frame,  which  consists  of  two  slant  rails  xs, 
xiy  connected  by  two  slender  rods  ya,  and  which  frame  may  be  set  more  or  less  obliquely. 
The  lower  rail  carries  the  brass  steps  for  the  points  of  the  spindles  b»;  upon  the  upper 
rail  brass  slips  are  fixed  pierced  with  holes  through  which  the  tops  of  the  spindles  play. 
The  spindles  are  as  usual  made  of  steel,  perlectly  straight,  turned  truly  round,  and  are 
all  arranged  in  one  plane.  To  each  of  them  a  small  wooden  or  cast-iron  whorl  gi  is 
u  A^^'  "^^^^  ^""^  distributed  into  groups  of  24,  and  the  whorls  are  arranged  at 
such  different  heights,  that  only  two  of  them  in  each  group  are  upon  a  level  with  each 
other.  A  small  brass  head  A2,  which  every  spindle  has  beneath  the  upper  slant  rail  of 
the  frame  xa,  prevents  their  sitting  down  into  the  step,  during  their  rotation,  or 
Sliding  off  their  cop  of  yarn, 

ci  are  drums,  mounted  in  the  carriage  in  a  plane  at  right  angles  to  the  plane  in 
which  the  spindles  are  placed.  At  top  they  have  a  double  groove  for  a  cord  to  run 
in,  and  the  motion  which  they  receive  from  the  great  fly  wheel,  or  rim  of  the  mule  (not 
visible  m  this  view)  they  impart  to  the  spindles.  Such  a  drum  is  assigned  to  every  24 
spindles ;  and  therefore  a  mule  of  480  spindles  contains  20  drums.  In  the  middle  of 
the  carriage  is  seen  the  horizontal  puUey  fca,  furnished  with  three  grooves,  which  stands 
in  a  Ime  with  the  drums  c3. 

The  motion  is  given  to  the  drums  c3,  upon  the  right  hand  half  of  the  carriage,  by  a 
single  endless  band  or  cord  which  proceeds  from  the  middle  groove  of  the  pulley  fc3 
The  rotation  of  the  spindles  is  produced  by  a  slender  cord,  of  which  there  are  12  upon 
each  drum  c3;  because  every  such  cord  ?oes  round  the  drum,  and  also  every  two  wharves 
which  stand  at  the  same  level  upon  the  spindles.  It  is  obvious  that  the  drums,  and 
consequently  the  spindles,  must  continue  to  revolve  as  long  as  the  main  rim  of  the  mule 
IS  turned,  whether  the  carriage  be  at  rest  or  in  motion  upon  its  railway. 

If  we  suppose  the  carriage  to  be  run  in  to  its  standing  point,  or  to  be  pushed  home 
to  the  spot  from  which  it  starts  in  spinning,  its  back  plank  di  will  strike  the  post  os 
upon  the  fixed  frame,  and  the  points  of  the  spindles  will  be  close  in  front  of  the  roller 
beam.  The  rollers  now  begin  to  turn  and  to  deliver  threads,  which  receive  immediately 
a  portion  of  their  twist  from  the  spindles;  the  carriage  retires  from  the  roller  beam 
with  somewhat  greater  speed  than  the  surface  speed  of  the  front  rollers,  whereby  the 
threads  receive  a  certain  degree  of  stretching,  which  affects  most  their  thicker  and  less 
twisted  portions,  and  thereby  contributes  greatly  to  the  levelness  of  the  yarn.  When 
the  carriage  has  run  out  to  the  end  of  its  course,  or  has  completed  a  stretch,  the  fluted 
roUers  suddenly  cease  to  revolve  (and  sometimes  even  beforehand,  when  a  second 
stretch  is  to  be  made),  but  the  spindles  continue  to  whiri  till  the  fully  extended  threads 
have  received  the  proper  second  or  after-twist.  Then  the  carriage  must  be  put  up,  or  run 
back  towards  the  rollers,  and  the  threads  must  be  Avound  upon  the  spindles. 

This  IS  the  order  of  movements  which  belong  to  the  mule.  It  has  been  shown  how 
the  rotation  of  the  spindles  is  produced. 

For  winding-on  the  yarn  the  carriage  has  a  peculiar  apparatus,  which  we  shall  now 
describe.  In  front  of  it,  through  the  whole  extent  to  the  right  hand  as  well  as  the  left, 
a  slender  iron  rod,  ds,  runs  horizontally  along,  in  a  line  somewhat  higher  than  the  mid- 
die  of  the  copping  portion  of  the  spindles,  and  is  supported  by  several  props,  such  as 
f .  Upon  each  end  of  the  two  rods,  ds,  there  is  an  arm,  gs ;  and  betwixt  these  arms  an 
iron  wire,  called  the  copping  wire,  /S,  is  stretched,  parallel  with  the  rod  d5.  For  the 
support  of  this  wire,  there  arc  several  slender  bent  arms  hs  extended  from  the  rod  ds 
at  several  points  betwixt  the  straight  arms  gs.  The  rod  ds  has,  besides,  a  wooden 
handle  at  the  place  opposite  to  where  the  spinner  stands,  by  which  it  can  be  readily 
grasped.  This  movement  is  applied  at  the  left  division  of  the  machine,  and  it  is  com- 
municated to  the  right  by  an  apparatus  which  resembles  a  crane's  bill.  The  two  arms. 
^,  m  the  middle  of  the  machine,  project  over  the  rods  ds,  and  are  connected  by  hinges 
with  two  vertical  rods;5,  which  hang  together  downwards  in  like  manner  with  two  a^i 
P,  proceeding  from  a  horizontal  axis  ks. 


COTTON  MANUFACTURE. 


531 


By  means  of  that  apparatus  the  yam  is  wound  upon  the  spindles  in  the  following 
manner.  As  long  as  the  stretching  and  twisting  go  on,  the  threads  form  an  obtuse  angle 
with  the  spindles,  and  thereby  slide  continually  over  their  smooth  rounded  tips  during 
their  revolution,  without  the  possibility  of  coiling  upon  them.  When,  however,  the  spin- 
ning process  is  completed,  the  spinner  seizes  the  carriage  with  his  left  hand  and  pushes 
it  back  towards  the  roller  beam,  while  with  his  right  hand  he  turns  round  the  handle  of 
the  rim  or  fly  wheel,  and  consequently  the  spindles.  At  the  same  time,  by  means  of 
the  handle  upon  the  rod  rfs,  he  moves  the  copping- wire /s,  so  that  it  presses  down  all  the 
threads  at  once,  and  places  them  in  a  direction  nearly  perpendicular  to  the  spindles ; 
as  shown  by  the  dotted  line  ys.  That  this  movement  of  the  copping  wire,  however,  may 
take  place  without  injury  to  the  yarn,  it  is  necessary  to  turn  the  rim  beforehand  a  little 
in  the  opposite  direction,  so  that  the  threads  may  get  uncoiled  from  the  upper  part  of  the 
spindles,  and  become  slack ;  an  operation  called  in  technical  language  the  backing  off. 
The  range  upon  which  the  threads  should  be  wound,  in  order  to  form  a  conical  cop  upon 
the  spindle,  is  hit  by  depressing  the  copping  wire  to  various  angles,  nicely  graduated  by 
an  experienced  eye.  This  faller  wire  alone  is  not,  however,  sufficient  for  the  purpose  of 
winding-on  a  seemly  cop,  as  there  are  always  some  loose  threads  which  it  cannot  reach 
without  breaking  others. 

Another  wire  called  the  counter-faller,  Is,  must  be  applied  under  the  threads.  It  may 
be  raised  to  an  elevation  limited  by  the  angular  piece  ps  ;  and  is  counterpoised  by  a  very 
light  weight  ms,  applied  through  the  bent  lever  n5,  which  turns  upon  the  fulcrum  o«. 
This  wire,  which  applies  but  a  gentle  pressure,  gives  tension  to  all  the  threads,  and 
brings  them  regularly  into  the  height  and  range  of  the  faller  fs.  This  wire  must  be 
raised  once  more,  whenever  the  carriage  approaches  the  roller  beam.  At  this  instaxt  a 
new  stretch  commences ;  the  rollers  begin  again  to  revolve,  and  the  carriage  resumes  its 
former  course.  ^  These  motions  are  performed  by  the  automatic  machinery. 

There  is  a  little  eccentric  pulley  mechanism  for  moving  the  guide  beam  to  and  frc 
with  the  soft  yarns,  as  they  enter  between  the  back  rollers.  On  the  right  hand  end  of 
the  back  roller  shaft,  a  worm  screw  is  formed  which  works  into  the  oblique  teeth  of  a 
pinion  attached  to  the  end  of  the  guide  beam,  in  which  there  is  a  series  of  holes  f(5r  the 
passage  of  the  threads,  two  threads  being  assigned  to  each  fluted  roller.  In  the  flat  disc 
of  the  pinion^  an  eccentric  pin  stands  up  which  takes  into  the  jointed  lever  upon  the  end 
of  the  guide  beam,  and,  as  it  revolves,  pushes  that  beam  alternately  to  the  left  and  the 
nght  by  a  space  equal  to  its  eccentricity.  This  motion  is  exceedingly  slow,  since  for 
each  revolution  of  the  back  roller,  the  pinion  advances  only  by  one  tooth  out  of  the  33 
which  are  cut  in  its  circumference. 

After  counting  the  number  of  teeth  in  the  different  wheels  and  pinions  of  the  mule,  or 
measuring  their  relative  diameters,  it  is  easy  to  compute  the  extension  and  twist  of  the 
yams;  and  when  the  last  fineness  is  given  to  ascertain  their  marketable  value.  Let  the 
ratio  of  speed  between  the  three  drawing  roUers  be  1  :  13  .  7| .  and  the  diameter  of  the 
back  and  middle  roller  three  quarters  of  an  inch  :  that  of  the  front  roller  one  inch ;  in 
which  case  the  drawing  is  thereby  increased  1|  times,  and  7^  X  1§  =  10.  If  the  rovings 
in  the  creel  bobbms  have  been  No.  4,  the  yarn,  after  passing  through  the  rollers,  will  b? 
No.  40.  By  altering  the  change  pinion  (not  visible  in  this  view)  the  fineness  may  be 
changed  withm  certain  limits,  by  altering  the  relative  speed  of  the  rollers.  For  one  revo- 
lution of  the  great  rim  or  fly  wheel  of  the  mule,  the  front  roller  makes  about  6  tenths  of 
a  turn,  and  delivers  therefore  22-6  lines  or  12ths  of  an  inch  of  yarn,  which,  in  conse- 
quence of  the  tenfold  draught  through  the  rollers,  corresponds  to  2-26  lines  of  roving  fed 
in  at  the  back  rollers.  The  spindles  or  their  whoris  make  about  66  revolutions  for  one 
turn  of  the  rim.  The  pulleys  or  grooved  wheels  on  which  the  carriage  runs,  perform 
0*107  part  of  a  turn  while  the  rim  makes  one  revolution,  and  move  the  carriage  24*1 
lines  upon  its  rails,  the  wheels  being  6  inches  in  diameter.  ** 

The  22-6  lines  of  soft  yarn  delivered  by  the  front  rollers  wUl  be  stretched  li  lines 
by  the  carriage  advancing  24-1  lines  in  the  same  time.  Let  the  length  of  the  railway, 
or  of  each  stretch,  be  5  feet,  the  carriage  will  complete  its  course  after  30  revolutions  of 
the  rim  wheel,  and  the  5  feet  length  of  yam  (of  which  56^  inches  issue  from  the  drawing 
rollers,  and  3|  inches  proceed  from  the  stretching)  is,  by  the  simultaneous  whiriing  of 
the  spmdies,  twisted  1980  times,  being  at  the  rate  of  33  twists  for  every  inch.  The 
second  twist,  which  the  threads  receive  after  the  carriage  has  come  to  repose,  is  regu- 
lated according  to  the  qualitj;  of  the  cotton  wool,  and  the  purpose  for  which  the  yarn  is 
spun.  Fo'- warp  yarn  of  No.  40  or  50,  for  example,  6  or  8  turns  of  the  rim  wheel,  that 
is,  from  396  to  528  whirls  of  the  spindles  for  the  whole  stretch,  therefore  from  7  to  9 
twists  per  inch  will  be  sufficient.  The  finished  yarn  thus  receives  from  40  to  42  twists 
per  inch. 

One  spinner  attends  to  two  mules,  which  face  each  other,  so  that  he  needs  merely 
turn  round  m  the  spot  where  he  stands,  to  find  himself  in  the  proper  position  for  the 
other  mule.    For  this  reason  the  rim  wheel  and  handle,  by  which  he  operates,  are  not 


532 


COTTON  MANUFACTURE. 


COTTON  MANUFACTURE. 


533 


s> 


placed  m  the  niiddle  of  the  length  of  the  machine,  but  about  two  fifths  of  the  spindles 
are  to  the  ngh  hand  and  three  fifths  to  the  left ;  the  rim  wheel  being  towards  his  rijfht 
hand.  The  carriage  of  the  one  mule  is  in  the  act  of  going  out  and  spinning,  while  that 
of  the  other  is  finishing  its  twist,  and  being  put  up  by  the  spinner. 

The  quantity  of  yarn  manufactured   by  a  mule   in  a  given  time,  depends  directly 
upon  the  number  of  the  spindles,  and  upon  the  time  taken  to  complete  every  stretch  of 
the  carriage.     Many  circumstances  have  an  indirect  influence  upon  that  quanlily  and 
particular])' the  degree  of  skill  possessed  by  the  spinner.    The  better  the  machine,  the 
steadier  and  softer  all  ils  pans  revolve,  the  better  and  more  abundant  is  its  production. 
When  the  toothed  wheels  do  not  work  truly  into  their  pinions,  when  the  spindles  shake 
in  their  bushes,  or  are  not  accurately  made,  many  threads  break,  and  the  work  is 
much  injured  and  retarded.    The  better  the  staple  of  the  cotton  wool,  and  the  more 
careful  has  been  its  preparation  in  the  carding,  drawing,  and  roving  processes,  the  more 
easy  and   excellent  the   spinning  wUl  become :    warmth,  drj  ness,  coW,  and   moisture 
nave  great  influence  on  the  ductility,  so  to  speak,  of  cotton.    A  temperature  of  66<»  F.. 
with  an  atmosphere  not  too  arid,  is  found  most  suitable  to  the  operations  of  a  spinnine 
null.    The  finer  the  yarn,  the  slower  is  the  spinning.     For  numbers  from  20  to  3^ 
irom  2  to  3  stretches  of  warp  may  be  made  in  a  minute,  and  nearly  3  stretches  of  weftl 
for  numbers  above  50  up  to  100,  about  2  stretches;  and  for  numbers  from  100  to  150 
one  stretch   in   the   minute.     Still  finer  yarns  are   spun   more   slowly,  which   is   not 
wonderful,  since,  in   the   fine   spinning   mills  of  England,  the  mules  usually  contain 
upwards  of  oOO  spindles  each,  in  order  that  one  operative  may  manage  a  great  number 
and  skS'  ^  ^         ^^"  *"*^^  ^^^  ^*^^^  *^  ^***^*  ^""^  remunerate  his  assiduity 

In  spinning  fine  numbers,  the  second  speed  is  given  before  the  carriage  is  run  out  to 
the  end  of  its  railway ;  during  which  course  of  about  six  inches,  it  is  made  to  move  very 
slowly.  This  IS  called  the  second  stretch,  and  is  of  use  in  making  the  varn  level  by 
drawing  down  the  thicker  parts  of  it,  which  take  on  the  twist  less  readily  than  the 
tJimner,  and  therefore  remain  softer  and  more  extensible.  The  stretch  may  therefore 
be  divided  into  three  stages.  The  carriage  first  moves  steadily  out  for  about  4  feet 
while  the  drawing  rollers  and  spindles  are  in  full  play ;  now  the  rollers  stop,  but  the 
spindles  go  on  whirling  with  accelerated  speed,  and  the  carriage  advances  slowly  about 
b  inches  more;  then  it  also  comes  to  rest,  while  the  spindles  continue  to  revolve  for  » 
httle  longer,  to  give  the  final  degree  of  twist.  The  acceleration  of  the  spindles  in  the 
second  and  third  stages,  which  has  no  other  object  but  to  save  time,  is  effected  by  a 
mechanism  called  the  counter,  which  shifts  the  driving  band,  at  the  proper  time,  upon  the 
loose  pulley,  and,  moreover,  a  second  band,  which  had,  till  now,  lain  upon  its  loose  pul- 
ley, upon  a  small  driving  pulley  of  the  rim-shaft.  At  length,  both  bands  are  shifted  upon 
tneir  loose  pulleys,  and  the  mule  comes  to  a  state  of  quiescence. 

The  SELF-ACTOR  MULE,  or  the  IRON  MAN,  as  it  has  been  called  in  Lancashire,  is  an 
invention  to  which  the  combinations  among  the  operative  spinners  obliged  the  masters 
to  have  recourse.  It  now  spins  good  yarn  up  to  40s  with  great  uniformity  ana 
promptitude,  and  requires  only  juvenile  hands  to  conduct  it,  to  piece  the  broken  yams, 
to  replace  the  bobbins  of  rovings  in  the  creel,  and  to  remove  the  finished  cops  from  the 
spindies. 

The  self-acting  mules  were  first  constructed,  I  believe,  by  Messrs.  Eaton,  formerly  of 
Manchester,  who  mounted  ten  or  twelve  of  them  in  that  town,  four  at  Wiln,  in  Derby- 
shire, and  a  few  in  France.  From  their  great  complexity  and  small  productiveness,  the 
whole  were  soon  relinquished,  except  those  at  Wiln.  M.  de  Jong  obtainctl  two  patents 
for  self  actmg  mules,  and  put  twelve  of  them  in  operation  in  a  mill  at  Warrington,  of 
Which  he  was  part  proprietor ;  but  with  an  unsuccessful  result.  I  saw  the  debris  of  one 
o!  M.  de  Jong's  self-actors  in  the  factory  of  M.  Nicholas  Schlumberger,  at  GuebwiUer 
m  Alsace,  where  the  machine  had  been  worked  for  three  months,  without  advantae^ 
under  the  care  of  the  inventor,  who  is  a  native  of  that  valley. 

The  first  approximation  to  a  successful  accomplishment  of  the  objects  in  view,  was  an 
jnyention  of  a  self-acting  mule,  by  Mr.  Roberts,  Of  Manchester ;  one  of  the  principal 
points  of  which  was  the  mode  of  governing  the  wiuding-on  of  the  yam  into  the  form  of 
a  cop;  the  entire  novelty  and  great  ineenuity  of  which  invention  was  universally  admit- 
ted,  and  proved  the  main  step  to  the  JSnal  accomplishment  of  what  had  so  h.ng  been  a 
desideratum.  For  tliat  invention  a  patent  was  obtained  in  1825,  and  several  headstocks 
upon  the  principle  were  made,  which  are  still  working  successfully.  - 

In  1830,  Mr.  Roberts  obtained  a  patent  for  the  invention  of  certain  improvements- 
and  by  a  combination  of  both  his  inventions,  he  produced  n  self-acting  mule,  which  i^ 
generally  admitted  to  liave  exceeded  the  most  sanguine  expectations,  and  which  has  been 
extensively  adopted.  There  are  probably,  at  present,  upwards  of  half  a  million  of  simi. 
dies  of  Messrs.  Sharp,  Roberts,  and  Co.'s  construction,  at  work  in  the  United  Kingdom 
giving  great  satisfaction  lo  their  possessors.  The  advantages  of  these  self-ictors' 
are  the  followmg : — 


The  saving  of  a  spinner's  wages  to  each  pair  of  mules,  piecers  only  being  required, 
as  one  overlooker  is  sufficient  to  manage  six  or  eight  pairs  of  mules.  The  production 
of  a  greater  quantity  of  yarn,  in  the  ratio  of  from  15  to  20  per  cent.  The  yarn  pos- 
sesses a  more  uniform  degree  of  twist,  and  is  not  liable  to  be  strained  during  the  spin- 
ning, or  in  winding-on,  to  form  the  cop ;  consequently,  fewer  threads  are  broken  in  these 
processes,  and  the  yarn,  from  having  fewer  piecings,  is  more  regular. 

The  cops  are  made  firmer,  of  better  shape,  and  with  undeviating  uniformity ;  and,  from 
being  more  regularly  and  firmly  wound,  contain  from  one  third  to  one  half  more  yarn 
than  cops  of  equal  bulk  wound  by  hand ;  they  are  consequently  less  liable  to  ihjury  in 
packing  or  in  carriage,  and  the  expense  of  packages  and  freight  (when  charged  by 
measurement)  is  considerably  reduced. 

Froin  the  cops  being  more  regularly  and  firmly  wcmnd,  combined  with  their  superior 
formation,  the  yarn  intended  for  warps  less  frequently  breaks  in  winding  or  reeling,  con- 
sequently there  is  a  considerable  saving  of  waste  in  those  processes. 

Secondly,  the  advantages  connected  with  weaving. 

The  cops  being  more  regularly  and  firmly  wound,  the  yarn,  when  used  as  weft,  sel- 
dom breaks  in  weaving ;  and  as  the  cops  also  contain  a  greater  quantity  of  weft,  there 
are  fewer  bottoms,  consequently  there  is  a  very  material  saving  of  waste  in  the  process 
of  weaving. 

From  those  combined  circumstances,  the  quality  of  the  cloth  is  improved,  by  being 
more  free  from  defects  caused  by  the  breakage  of  the  warp  or  weft,  as  well  as  the  sel- 
vages being  more  regular. 

The  looms  can  also  be  worked  at  greater  speed ;  and,  from  there  being  fewer  stop- 
pases,  a  greater  quantity  of  cloth  may  be  produced. 

That  the  advantages  thus  enumerated,  as  derivable  from  the  use  of  self-acting  mules, 
have  not  been  overrated,  but,  in  many  instances,  have  been  considerably  exceeded,  I 
have,  by  extensive  personal  inquiry  and  observation,  had  ample  opportunity  of  ascer- 
taining. 

Statement  of  the  quantity  of  yarn  produced  on  Messrs.  Sharp,  Roberts,  and  Co.*s  self- 
acting  mules,  in  twelve  working  hours,  including  the  usual  stoppages  connected  with 
spinning,  estimated  on  the  average  of  upwards  of  twenty  miUs  : — 


No.  of  Weft. 

4|  hanks  per  spindle. 
4|  - 

4f  - 

4^ 


No.  of  Yam.  Nu.  of  Twist. 

16        -        -        4|  hanks 

24        -        -       4J    —  -        - 

32       -        -        4      —  -        - 

40        -        -        3f    —  -        - 

Of  the  intermediate  numbers  the  quantities  are  proportionate. 

Results  of  trials  made  by  Messrs.  Sharp,  Roberts,  and  Co.,  at  various  mills,  to  aseer* 
tain  the  comparative  power  required  to  work  self-acting  mules,  in  reference  to  hand* 
mules,  during  the  spinning,  up  to  the  period  of  backing  ofif. 

Particulars  of  the  trials  referred  to,  and  their  results : — 


U.8 

■ss 

§, 

At  what  Mill,  and  the  Description  of 

No.  and  kind 

5SS 

Total  Force 

Mule. 

of  Yarn. 

ill 

rolnt 

lley< 

Wh 

0   k. 

Employed  in 
Spinning. 

«2 

S,  3 

Pi  ft. 

p; 

Messrs.  Birley  and  Kirk, 

Weft. 

Ins, 

ft*. 

1b», 

Self-acting  mule,  360  sps.  -    - 

30  to  34 

12 

58 

30 

5463 

•  Hand-mule,  180  sps.  -    -    - 

ditto 

15 

36 

26 

3669) 
X2=7338  J 

Messrs.  Leech  and  Vandrey, 

Twist. 

t  Self-acting  mule,  324  sps.    - 

36 

12 

70 

36 

7912 

Hand-mules,  324  sps.   •    -    • 

36 

29 

58 

161 

7273 

Messrs.  Duckworth  4r  Co, 

TwUt. 

Self-acting  mule,  324  sps.  -    - 

40 

12 

62 

33 

6421 

Hand-mule,  324  sps.     -    -    - 

40 

47 

36 

151 

6646 

The  mode  adopted  to  make  the  trials  was  as  follows,  viz. : 

A  force,  indicated  by  weight  in  pounds,  was  applial  to  the  strap  working  upon  the 

!  S"  !^*l  '^"  ^isadvanta^eoue  for  the  hand-mulee,  bein;  two  for  360  epindles. 


5U 


COURT  PLASTER. 


I 


driving-pulley  of  the  respective  mules,  sufficient  to  maintain  the  motion  of  the  mnk 
whilst  spinning,  which  weight,  being  multiplied  by  the  length  of  strap  delivered  by  each 
revolution  of  the  pulley,  and  again  by  the  number  of  revolutions  made  by  the  pulley 
whilst  spinning,  gave  the  total  force  in  pounds,  applied  to  the  respective  mules  whilst 
spinning ;  for  instance,  suppose  a  mule  to  be  driven  by  a  pulley  12  inches  diameter  (3*  14 
feet  in  circumference),  such  pulley  making  58  revolutions  during  the  spinning  as  above, 
and  that  it  required  a  force  equal  to  30  lbs.  weight  to  maintain  the  motion  of  the  mule, 
then  30  lbs.  X  3-14  feet  circumference  of  pulley  X  58  revolutions  in  spinning  =  5,463  lbs. 
of  force  employed  during  the  spinning,  to  the  period  of  backing  off. 

Mr.  James  Smith,  of  Deanstone  cotton  works  in  Scotland,  obtained  a  patent  for  the 
invention  of  a  self -actor ,  in  February,  1834.  He  does  not  perform  the  backing-off  by 
reversing  the  rotation  of  the  spindle,  as  in  common  mules,  or  as  in  Mr.  Roberts',  but  by 
elevating  the  counicrfaller  wire,  which,  being  below  the  ends  of  the  yam  or  thread, 
along  the  whole  extent  of  the  carriage,  thereby  pulls  off  or  strips  the  spiral  coils  at  the 
point  of  the  spindle,  instead  of  unwinding  them,  as  of  old.  This  movement  he  con- 
siders to  be  of  great  importance  towards  simplifying  the  machinery  for  rendering  the 
mule  self-acting ;  and  the  particular  way  in  which  he  brings  the  stripper  into  action  is 
no  doubt  ingenious,  but  it  has  been  supposed  by  many  to  strain  the  yam.  He  claims  as 
his  invention  the  application  and  adaptation  of  a  mangle  wheel  or  mangle  rack  to  the 
mule,  for  effecting  certain  successive  movements,  either  separately  or  in  conjunction ;  he 
claims  that  arrangement  of  the  carriages  of  a  pair  of  mules,  by  which  the  stretch  is 
caused  to  take  place  over  part  of  the  same  ground  by  both  carriages,  and  thereby  the 
space  required  for  the  working  of  the  pair  of  mules  is  greatly  diminished ;  and  he  claims 
the  application  of  a  weight,  spring,  or  friction,  for  balancing  the  tension  of  the  ends  of 
the  threads. 

A  patent  was  granted,  in  April,  1835,  to  Mr.  Joseph  Whitworth,  engineer  in  Man 
diester,  for  some  ingenious  modifications  of  the  mechanism  of  the  mule,  subservient  to 
automatic  purposes.  His  machinery  is  designed,  first,  to  traverse  the  carriage  in  and 
out,  by  means  of  screws  or  worm-shafts,  which  are  placed  so  as  to  keep  the  carriage 
parallel  to  the  drawing  rollers,  and  prevent  the  necessity  of  squaring  bands,  hitherto 
universally  employed  :  secondly,  his  invention  consists  in  an  improved  manner  of  work- 
ing the  drums  of  a  self-acting  mule  by  gear ;  thirdly,  in  the  means  of  effecting  the 
backing  off;  fourthly,  in  the  mechanism  for  working  the  faller-wire  in  building 
the  cops;  and  fifthly,  in  the  apparatus  for  effecting  the  winding  of  the  yams  upoa 
the  spindles.  As  regards  the  throstles  and  doubling  frames,  his  improvements  apply, 
first,  to  the  peculiar  method  of  constructing  and  adapting  the  flyers  and  spindles,  and 
producing  the  drag ;  and,  secondly,  to  the  arrangement  of  the  other  parts  of  the  doubling 
machinery. 

See    Lace-Making,    Singeing,    Textile   Fabric,   Thbead   Manufacture,    and 
Weaving. 

We  extract  the  following  from  the  Circular  of  Hermann  Cox  and  Co.,  dated  19th 
July,  1852. 

Export  from  Ut  January  to  5th  May,  as  follows : 

1853.  1851. 

Exportationa  of  Yarn    -  -  -        60,399,189  lbs.        42,630,812  lbs. 

„  Manufactured  Goods    -      509,360,295  yda     493,915,720  yds. 

consequently  a  considerable  surplus  on  both  over  last  year ;  the  official  return  till  6th 
June,  just  out^  again  shows  an  increase,  viz. : 

1852.  1851. 

ExportetionsofYarn    -  -  -        68,418,111  lbs.         54,634,870  lbs. 

„  Manufactured  Goods    -      649,841,927  yda      630,581,674  yda 

The  following  is  a  return  of  exports  from  Hull,  from  Ist  January  till  30th  June : 


Twist. 

Other  Yam. 

Manufactured 
Cotton  Goods. 

Raw  Cotton. 

1862. 

-     83,182  bale& 

12,115  bales. 

11,536  bales. 

66,186  bales. 

1861. 

-     31,601     „ 

9,634    „ 

11,347     „ 

83,054     „ 

COTTON. 
AMERICA 


535 


1351. 

1R.W, 

Stock  Ist  September  in  the  Ports    - 
Receipts  till  22d  June          ... 

Shipments  to  Europe  till  22d  June 

Deduct  Stock  22d  June        -            .            - 
American  Consumption  for  1861 

148,000  bales. 
2,250,000    „ 

128,000  bales. 
2,936,000     „ 

2,398,000     „ 
1,768,000    „ 

640,000    „ 
304,000    „ 

3,064,000    „ 
2,263,000     „ 

801,000    „ 
201,000     „ 

336,000  bales. 

600,000  bales. 

Last  year  the  American  spinners  took  from  the  above-named  last  date  till  Ist  Sept, 
137,000  bales. 

FRANCE. 

Notwithstanding  96,348  bales  larger  supply,  the  stock  is  still  12,293  bales  smaller 
than  last  year. 


1851. 

Stock, 
1st  January. 

Imports 
to  Ist  July. 

Total. 

Deduct  Stock, 
Ist  July. 

Leaves  for 
Consumption. 

Havre 
Marseilles 

or  7,612  bales  per 

Havre 

Marseilles 

39,825 
15,095 

210,140 
26,124 

249,965 
41,219 

78,377 
17,479 

171,588  bales. 
23,740    „ 

64,920 
week. 

22,767 
7,661 

236,264 

297,514 
36,098 

291,184 
1S52. 

320,281 
42,759 

95,856 

75,271 
8,292 

195,328  bales. 

245,010  balea 
34,467     „ 

30,428 

332,612 

363,040 

83,663 

279,477  balea 

or  10,749  bales  per  week  this  year  against  7,512  bales  in  the  same  period  last  year,  of 
7,326  bales  average  of  1851. 

REMAINING  CONTINENT. 
We  find  the  consumption  of  the  first  six  months  of  1851  and  1852  to  be  as  follows: 


i851. 

Stock, 
Ist  January. 

Direct 
Imports. 

ToUL 

Deduct  Stock, 
UtJuly. 

Leaves  for 
Coiwumption. 

Hamburg              ... 
Bremen      .... 
Petersburg:  and  Sweden 
Amsterdam           .           -          - 
Rotterdam             ... 
Antwerp    .          •          .          • 
Trieste       .           -           .           - 
Sp«iQ,  Portugal,  and  Italy 

6,300 

89 

5,575 

1,362 

467 

4,578 

22,596 

6,000 

33,730 

21,191 

7,000 

4,888 

1,912 

25,173 

79.582 

68,000 

40,030 

21,280 

12.575 

6.250 

2,379 

29,751 

102,178 

74,000 

6,730 
12,133 
4,0(10 
2.698 
1,333 
8,500 
49,004 
8,000 

33.300  bales. 

9,147     „ 

8,575     „ 

3.552      „ 

1,046      „ 

21,251      „ 

53,174      ., 

66,000      „ 

46,967 

241,476 

Ad(j 

288,413                 92,398 
1  Export  from  England 

196,045  bales. 
95,300      „ 

Total 

. 

291,345  bales. 

or  11,206  bales  per  week. 


536 


COTTON. 


1852. 


Hamburg  -  -  - 

Bremen      .  -  - 

Petersburg  and  Sweden 
Amsterdam 
Rotterdam 

Antwerp    -  -  - 

Trieste       ... 
Spain,  Portugal,  and  Italy 


stock. 

Direct 

ToUL 

1st  Januitry. 

Iiii|K>rt8. 

5,900 

65,929 

71.829 

1,664 

16.306 

17,967 

2,000 

23,000 

25,000 

2,101 

6,890 

8.991 

928 

11.581 

12,509 

1,196 

54.282 

55.478 

25,914 

72.392 

98,306 

4,219 

97,000 

101,219 

847,377 

Deduct  Stock 
1st  July. 


17,990 
3,304 
5,000 
4,157 
8.350 
22,000 
29,857 
9,000 


99,658 
Export  firom  England 

Total 


Leaves  for 

Consumption. 

53,839  bales. 

14663 

20.000 

n 

4,834 

» 

4,159 

33.478 

t9 

68,449 

It 

92,219 

•> 

291,641  bales. 

147,000 

" 

438,641  bales.   1 

or  16,870  bales  per  week,  against  11,205  bales  in  the  first  half  of  last  year,  or  against 
11,664  bales  average  of  the  whole  period  of  1851. 

The  total  consumption  of  all  countries  according  to  the  preceding  statements  is  as 
follows : 


England 

America 

France 

Kemaining  Continent 


89,683  bales,  against  29,851  bales,  1851. 
11,538  „  6,461 

10,749  „  7,512 

16,870  „  11,205  „ 


78,840  65,029  bales  per  week 

To  which  we,  however,  consider  it  advisable  to  add,  that  this  increase  in  the  consump- 
tion for  the  first  half  year  (viz.,  23,811  bales  per  week)  should  not  be  taken  as  any 
criterion  against  the  consumption  of  the  same  period  last  year,  when  it  was  so  much 
restricted  through  the  drooping  state  of  prices,  and  when  spinners  were  induced  to  use 
up  their  whole  stocks.  We  affirm  therefore  that  this  increase  of  consumption  should 
only  be  considered  in  comparison  with  the  average  consumption  of  the  whole  of  last 
year,  viz. : 

In  England       •-  •  •  >  -81,973  bales  in  1851. 

America       --.---        9,479  „ 

France  .--...        7,326  „ 

Remaining  Continent  -  -  •  -      11,664 


M 


Against 


60,442  bales  per  week. 
78,840      „     this  year. 


We  have  thus  far  represented  the  consumption — the  extraordinary  increase  of  the 
same  in  all  countries,  without  exception,  proves  how  cheap  food,  with  peace,  tends  to 
enlarge  consumption ;  and  it  remains  therefore  only  to  be  hoped  that  the  favorable 
prospects  for  the  ensuing  crop  be  not  blighted.  It  is  clearly  evident  that  present  prices 
do  not  affect  the  consumption  ;  for  the  planters  they  are  sufficiently  remunerative  to 
induce  an  extension  of  the  culture,  and  so  provide  for  the  world  such  stocks  as  would 
prevent  any  ill  effect  arising  from  a  future  small  or  bad  crop. 

It  shall  now  be  our  endeavor  to  point  out  the  position  of  stocks  in  all  Europe 
on  the  31st  December  this  year,  supposing  the  consumption  to  continue  at  its  present 
rate: 


The  American  crop    -  -  -  -  - 

Of  which  were  received  by  the  last  list  of  22d  June 

Remain  to  receive      -  -  -  -  - 

Stocks  in  the  ports  and  on  shipboard  22d  June 


The  average  stock  left  in  the  ports  during  the  last  six  years 
was  about  150,000  bales,  but  we  will  take  for  this  year 
only         ------- 

Would  leave  for  all  Europe 
Suppose  American  spinners  take  nothing  more  from  22d  June 
till  Ist  September. 


8,000,000  bales. 
2,936,329     „ 


63,671     „ 
201,773     „ 


265«4U 
100,000    „ 


165,444    „ 


COTTON. 

Brought  forward 

From  America,  floating  to  England      -             .  -  - 

„            „            „         to  other  countries       -  -  - 

„      India           „        to  England      -            -  -  - 

to  receive  from  other  countries  till  3 Ist  December,  equal  to  last  year. 

England        -    from  Egypty  Brazils,  and  Sundries  -  83,000 

France           -      „      Egypt,  Brazils,  and  Smyrna  -  26,000 


53T 


165.444  bale«. 
150,000  „ 
100,000 
100,000 


>f 


Trieste,  and  )  -r.       ^  t»      -i         j  a 

other  Ports,  \      »»     ^P^  Brazds,  and  Smyrna 


40,000 


Total  supply  for  Europe 

Add  stocks  in  all  European  ports  on  1st  July 


149,000    „ 

664,444    „ 
900,421     „ 


Total 


Quantity  of  American,  next  crop,  to  be  received  in  England 
Ditto  in  Continental  ports        .... 


1,564,865     „ 

150,000     „ 
75,000    „ 


1,789,685  bales. 
Therefore,  if  the  present  consumption  of  Europe  were  to  continue  to  the  end  of  th« 
year,  the  stock  would  be  only  39,084  in  all  European  ports,  not  enough  for  one  week. 

Table  of  Imaginary  Stocks  in  Great  Britain  on  Slat  December,  1852. 
The  American  crop       ......     8,000,000  balea 

Of  which  were  received  by  the  last  list  of  22d  June    -  -     2,936,329    „ 

Remain  to  receive         -  .  .  -  - 

Stocks  in  the  ports  and  on  shipboard  22d  June 


The  average  stock  left  in  the  ports  during  the  last  six  years  was 
about  150,000  bales,  but  we  will  take  for  this  year  only 

We  will  suppose  American  spinners  to  take  nothing  more  till 
1st  September,  and  supposing  the  32  ships  loading  for 
France,  and  125  for  other  ports  take  only 

Would  leave  for  Great  Britain  - 

As  the  stocks  in  the  interior  markets  are  only  one  third  of  those 
of  last  year,  shipments  after  August  must  fall  very  short ; 
but  supposing  England  to  receive  from  1st  September  till 
31st  December       -.---- 
Now  floating  to  England  -  -  -  -  - 

From  India  we  will  suppose      .  -  -  .  - 

From  Brazils,  Egypt,  Ac,  like  last  year  in  the  same  period    - 


Add  stock  1st  July  in  Great  Britain 


Total  to  receive    - 


JExport 

until  Ist  July  last  year  was  95,300  bales,  for  the  same  period  this 
year  147,000  bales.  We  have  shown  that  the  Continental  stocks, 
notwithstanding  so  much  larcer  receipts,  are  only  near  on  a  par 
with  those  of  last  year ;  this  leads  us  to  suppose  that  our  market 
must  later  assist  those  by  large  exports,  but  we  will  take  such  only 
equal  to  last  year,  viz.         --.... 


63,671 
201,773 

n 

tt 

265,444 

t» 

100,000 

n 

165,444 

n 

65,444 

tt 

100,000 

tt 

150,000 

150,000 

100,000 

83,000 

>« 
»» 
»» 

583,000 
717,200 

1,300,200  balea 

121.000  balesw 


Leaves         -  -  .  .  .     i,i79,200    „ 

Whereas  the  present  rate  of  consumption  requires  till  31st  Dec     -     1,031,758  bales. 
This  would  leave  us  a  stock  at  this  year's  end  of  all  descriptions  of  147,442  bales  only, 
not  sufficient  for  the  consumption  of  four  weeks ;  supposing,  however,  the  consumption 
to  fall  to  only  83,000  bales  per  week,  the  remaining  stock  would  be  only  821,000  bale% 
against  494,000  bales  at  the  end  of  last  year. 


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COTTON  (GUN). 


COTTON  SPINNING.  Messrs.  Tatham,  Cbeetham,  and  Duncan,  obtained  in  1846 
n  patent  for  sundry  improvements  in  apparatus  for  cotton  spinning.  Their  first  in- 
vention applies  \o  the  scutcher,  a  machine  by  which  the  cotton  is  cleansed  and  lapped 
in  a  compact  and  even  sheet  or  lap  upon  a  roller  preparatory  to  its  being  fed  into  the 
carding  engine,  and  consists  in  a  new  arrangement  of  rollers  for  compressing  or  calen- 
dering thelheet  of  tjotton  previous  to  its  being  lapped  upon  the  roller;  and  also  in  a 
new  method  of  weighting  the  calendering  rollers,  whereby  the  pressure  is  gradually  in- 
creased as  the  sheet  of  cotton  approaches  the  lap.  The  second  part  of  the  invention 
consists  in  the  employment  of  an  apparatus  for  collecting  the  fibres  of  cotton  from  the 
dust  which  is  blown  by  the  fan  from  the  scutcher. 

Tlie  third  part  of  the  invention  is  an  improvement  upon  machinery  patented  by 
Tatham  &  Cheetham  in  March,  1844,  which  caused  the  sliver  to  be  twisted  as  it  is 
delivered  from  the  carding  engine  into  the  tin-can  receptacle. 

The  fourth  relates  to  the  apj)lication  of  gutta  percha  tintawan  for  covering  rollers 
used  in  the  several  machines  employed  in  cotton  spinning.  These  substances  may  be 
used  either  alone,  or  combined  with  sulphurets,  <fec. 

The  fifth  invention  relates  to  the  "flyer"  now  usually  employed  in  "presser  frames.'* 
Here  the  legs  or  arms  of  the  flyer  (being  jointed  above  the  top  or  elbow)  are  caused  to  act 
upon  the  bobbin  like  tongs,  and  thus  dispense  with  the  small  spur  or  level  at  the  bottom 
of  the  flyer,  called  the  presser.  Through  the  boss  or  upper  part  of  the  flyer  the  sliver 
or  roving  of  cotton  passes  to  the  hollow  arm.  The  top  part  and  arms  are  joined  to- 
gether, and  swivel  upon  a  central  pin  or  stud.  At  this  joint  a  coiled  spring,  exactly  simi- 
lar to  the  ordinary  snuffers-spring,  is  inserted,  one  end  of  which  is  to  be  fast  to  the  head, 
and  the  other  end  to  the  arm  of  the  flyer;  whereby  the  desired  elasticity  is  imparted  to 
the  arms,  to  effect  the  pressure  on  the  bobbin.  The  lower  end  of  the  arm  must  be  smal- 
ler, to  lap  one  or  two  folds  of  the  roving  around  it  to  create  the  drag  usually  obtained 
by  the  folds  around  the  common  press  or  level. — Newton's  Journal,  xxxi.,  p.  77. 

In  cotton  spinning  machines  the  roving  and  slubbing  frames  move  at  a  great  velocity, 
and  are  liable  to  vibrations,  and  consequently  to  much  wear  and  tear,  wliieh  Mr.  Ed- 
mund Hartley,  of  Oldham,  has  tried  to  remedy  by  patented  contrivances,  while  the 
speed  is  increased.  He  has  also  sought  to  improve  the  backing  off  motion  in  self-actor 
mules.     For  description  of  his  invention,  see  Newton's  Journal,  vol.  xxxvi.,  p.  300. 

COTTON  (GUN).  M.  Schonbein,  the  patentee,  states  that  the  invention  consists  in 
the  manufacture  of  explosive  compounds  applicable  to  mining  purposes  and  to  projec- 
tiles, and  as  substitutes  for  gunpowder,  by  treating  and  combining  matters  of  vegetable 
origin  with  nitric  and  sulphuric  acids. 

The  matter  of  vegetable  origin  which  he  prefers,  as  being  best  suited  for  the  purposes 
of  the  invention,  is  cotton,  as  it  comes  into  this  country,  freed  from  extraneous  matters; 
and  it  is  stated  to  be  desirable  to  operate  on  the  clean  fibres  of  the  cotton  in  a  dry 
state.  The  acids  are  nitric  acid  of  from  145  to  1*50  specific  gravity,  and  sulphuric  acid 
of  1"85  specific  gravity. 

The  acids  are  mixed  together  in  the  proportions  of  1  measure  of  nitric  to  3  measures 
of  sulphuric  acid,  in  any  suitable  or  convenient  vessel  not  liable  to  be  affected  by  the 
acids.  A  great  degree  of  heat  being  generated  by  the  mixture,  it  is  left  to  cool  until  its 
temperature  falls  to  60*  or  50*  Fahr.  The  cotton  is  then  immersed  in  it,  and  in  order  that 
it  may  become  thoroughly  impregnated  or  saturated  with  the  acids,  it  is  stirred  with  a 
rod  of  glass  or  other  material  not  affected  by  the  acids.  The  cotton  should  be  introduced 
in  as  open  a  state  as  practicable.  The  acids  are  then  poured  or  drawn  off,  and  the  cotton 
gently  pressed  by  a  presser  of  glazed  earthenware,  to  press  out  the  acids,  after  which 
it  is  covered  up  in  the  vessel,  and  allowed  to  stand  for  about  an  hour.  It  is  subsequently 
washed  in  a  continuous  flow  of  water  until  the  presence  of  the  acids  is  not  indicated  by 
the  ordinary  test  of  litmus  paper.  To  remove  any  uncombined  portions  of  the  acids 
which  may  remain  after  the  cleansing  process,  the  patentee  dips  the  cotton  in  a  weak 
solution  of  carbonate  of  potash,  composed  of  1  oz.  of  carbonate  of  potash  to  1  gallon 
of  water,  and  partially  dries  it  by  pressing,  as  before.  The  cotton  is  then  highly  explo- 
sive, and  may  be  used  in  that  state ;  but,  to  increase  its  explosive  power,  it  is  dipped  in 
a  weak  solution  of  nitrate  of  potash,  and,  lastly,  dried  in  a  room  heated  by  hot  air  or 
steam  to  about  1 50*  Fahr. 

It  is  considered  probable  that  the  use  of  the  solutions  of  carbonate  of  potash  and 
nitrate  of  potash  may  be  dispensed  with,  although  actual  experience  does  not  warrant 
such  an  omission.  The  patentee  remarks,  that  nitric  acid  may  be  employed  alone  in 
the  manufacture  of  explosive  compounds,  but  that,  as  far  as  his  experience  goes,  the 
article  when  so  manufactured  is  not  so  good,  and  far  more  costly. 

"When  used,  care  should  be  taken  to  employ  a  much  less  quantity  by  weighty  to  pro- 
duce the  same  result,  than  of  gunpowder ;  and  it  has  been  found  that  three  parts  by 
weight  of  the  cotton  produce  the  same  effect  as  eight  parts  by  weight  of  the  Tower- 
proof  gunpowder. 


COTTON  (GUN). 


547 


The  cotton,  when  prepared  in  the  manner  before  mentioned,  may  be  rammed  into  a 
piece  of  ordnance,  a  fowling-piece,  or  musket ;  or  may  be  made  up  into  the  shape  of 
cartridges;  or  may  be  pressed,  when  damp,  into  moulds  of  the  form  of  the  bore  of  the 
piece  of  ordnance  for  which  it  is  intended,  so  that^  when  dried,  it  shall  retain  the  re- 
quired figure;  and  it  may  also  be  placed  in  caps,  like  percussion  caps,  and  made  to  ex- 
plode by  impact  Lastly,  the  patentee  states,  that  although  he  prefers  the  use  of  cotton, 
other  matters  of  vegetable  origin  may  be  similarly  treated  with  acids  to  form  an  explo- 
sive compound,  and  that  acids  of  an  inferior  specific  gravity  may  be  employed. 

Cotton  (Gun),  spontaneous  combustion  of,  {by  Dr.  Gladstone). — "  Gun-cotton,  as  com- 
monly produced,  especially  for  preparation  of  collodium,  is  a  mixture  of  two  distinct 
though  analogous  substances.     The  one  is  designated  pyroxyline,  and  has  the  formula 

It  leaves  no  residuum  on  explosion  ;  is  insoluble  in  ether,  <fec. 
the  appellation  Cotton-xyloidine,  and  the  formula 


The  other  has  received 


^'  \  3N04  \  ^2° 


It  leaves  a  residue  on  explosion  ;  is  soluble  in  ether,  <kc. 

"  Pyroxyline,— This  substance  is  produced  only  when  cotton  or  cotton-xyloidine  is 
immersed  in  a  mixture  of  nitric  acid,  of  sp.  gr.  1-5,  with  strong  oil  of  vitrol.  Although 
it  contains  so  large  an  amount  of  oxide  of  nitrogen,  I  am  acquainted  with  no  clear  in- 
stance in  which  it  has  undergone  spontaneous  decomposition.  Specimens  obtained  by 
the  action  of  the  mixed  acids  on  cotton-xyloidine  have  shown  no  indications  of  change  • 
and  pyroxyline  obtained  in  a  compact  translucent  form,  from  solution  in  acetic  ether* 
has  also  remained  unaltered.  * 

"  Cotton-Xyloidin€.—Th.\»  may  be  prepared  in  a  state  of  purity,  and  in  a  pulverulent 
condition,  by  dissolving  cotton  or  pyroxyline  in  nitric  acid  of  about  sp.  gr.  1-46  and 
precipitating  the  substance  by  water.  ' 

"Several  specimens  of  this  compound  made  from  both  sources  have  hitherto  suffered 
no  decompositions,  but  they  have  been  generally  kept  in  the  dark.  One  sample  of  pre- 
cipitated cotton-xyloidine  placed  in  a  stoppered  bottle  remained  in  a  cupboard,  the  door 
of  which  was  sometimes  opened  and  sometimes  closed.  After  the  lapse  of  about  three 
years  it  suddenly  began  to  evolve  nitric  oxide  and  water:  the  action  continued  for  a 
few  weeks,  and  then  nothing  remained  but  a  small  quantity  of  a  transparent  gummy 
mass  of  a  light  brown  color,  and  possessed  of  a  very  peculiar  odor.  Several  months 
produced  no  further  alteration. 

"This  product  of  decomposition,  which  had  about  the  tenacity  and  consistency  of 
ordinary  gum,  was  not  explosive :  when  heated  in  a  closed  tube,  per  se,  it  gave  off  red 
fumes,  and  afterward  swelled  up,  being  carbonized,  and  evolving  empyreumatic  oils.  It 
was  found  to  be  insoluble  in  cold  water,  but  when  boiled  in  that  liquid,  it  swelled  up  as 
a  gelatinous  mass,  and  became  disintegrated.  There  resulted  a  solution  which  reddened 
litmus  paper  slightly,  containing,  however,  no  oxalic  acid,  but  a  small  quantity  of  an- 
other  acid,  which  gave  a  flocculent  white-lead  salt,  insoluble  in  excess  of  acetic  acid- 
the  substance  m  question,  though  insoluble  in  cold  water,  dissolved  readily  in  aqueous 
solution  of  potash:  yet  it  appeared  to  be  altered  in  combining  with  the  alkali,  for  it 
was  not  re-precipitated  when  the  potash  was  supersaturated  by  an  acid. 

"  Starch-Xyloidin£.—ThiB  is  the  well-known  substance  produced  when  starch  is 
treated  with  strong  nitric  acid,  and  water  is  added  to  the  viscid  mass.  Its  composition 
varies ;  but  it  is  in  general  analogous  to,  if  not  identical  with,  that  ascribed  above  to 
cotton-xyloidine. 

"A  large  specimen,  freely  exposed  to  the  light  during  more  than  four  years,  re- 
mained unaltered.  j      "> 

**  Higher  Starch  Compound— When  ordinary  starch-xyloidine  is  treated  with  a  mix- 
ture of  fuming  nitric  and  sulphuric  acids,  and  subsequently  washed,  it  is  found  to  have 
greatly  increased  in  weight  The  resulting  substance  is  more  combustible  than  the 
origina  xyloidine,  and  differs  from  it  in  several  respects,  but  is  not  identical  with  the 
pyroxyline  obtained  from  woody  fibre. 

"A  sample  of  this  product,  which  had  been  left  eight  or  nine  months  in  a  room  where 
ight  freely  entered  was  found  wholly  decomposed  ;  nitrous  fumes  and  vapor  of  water 
had  been  evolved  leaving  a  dark  sticky  residue.  This  new  substance  was  soluble  in 
water  and  in  alcohol ;  crystallizing  from  the  latter  in  tufts,  which  under  the  microscope 
had  a  beautiful  arborescent  appearance.  It  remained  a  couple  years  or  more  dissolved 
in  a  very  small  quantity  of  water.  What  changes  may  have  taken  place  in  it  during 
that  period  is  unknown,  since  no  proper  examination  had  been  previously  made,  but 
after  the  lapse  of  that  Ume,  the  solution  was  found  to  be  almost  black  and  strongly  acid 


548 


COTTON  (GUN). 


When  neutralized  with  an  alkali  it  gave  a  copious  precipitate  on  the  addition  of  nitrat« 
of  silver,  and  a  floceulent  salt,  or  rather  mixture  of  salts,  with  chloride  of  calcium, 
which,  when  dried  and  heated  with  hydrate  of  potash,  evolved  ammonia.  At  the  bot- 
tom of  the  vessel  containing  the  aqueous  solution  there  had  grown  a  compound  crystal, 
transparent  and  colorless,  with  the  exception  of  a  few  brown  specks.  It  had  the  rhom> 
boidal  form  which  oxalic  acid  usually  assumes,  and  upon  further  examination  and 
analysis  proved  to  be  that  substance. 

"A  small  sample  of  this  same  starch  compound,  which  had  been  washed  repeatedly 
with  glacial  acetic  acid  for  complete  purification,  and  which  had  been  kept  constantly 
in  the  dark  was  found  to  have  suffered  decomposition,  nothing  remaining  but  a  vis- 
cous acid  liquid.  When  examining  these  decomposed  explosive  compounds,  I  found  in 
my  laboratory  a  bottle  filled  with  a  brown  sticky  mass ;  the  label  having  been  de- 
stroyed by  evolved  acid,  it  could  not  be  positively  identified,  but  I  have  good  reason 
to  believe  it  had  originally  been  the  higher  starch  compound  :  the  substance  had  a 
strong  odor  of  hydrocyanic  acid.  Its  solution,  in  either  water  or  alcohol,  had  a  strong 
acid  reaction.  It  gave  no  precipitate  with  chloride  of  calcium.  Floceulent  salts  con- 
taining metallic  oxides  or  baryta,  all  easily  soluble  in  nitric  acid,  were  readily  pro- 
duced. Its  combinations  with  the  alkalis  gave  dark  brown  aqueous  solutions,  from 
which  they  separated  in  an  amorphous  form  on  evaporation,  but  though  exceedingly 
soluble  in  water,  they  were  precipitated  on  the  addition  of  alcohol.  The  mass  was 
probably  a  mixture  of  different  acids,  principally  non-azotized,  for  little  nitrogen  was 
discoverable ;  and  although  oxalic  acid  itself  was  absent,  it  is  by  no  means  improbable 
that  some  higher  members  of  the  series,  Cn  Ilni  O4  were  present. 

"  Hitro-Mannite. — ^This  substance,  first  described  by  MM.  Flores  Domonte  and  Me- 
nard, is  formed  when  mannite  is  dissolved  in  fuming  nitric  acid,  and  precipitated  by 
sulphuric  acid.  Its  formula,  according  to  Strecker,  is  Cu  Ha  (NO4  )  Oi*.  It  is  the 
only  known  crystallizable  body  belonging  to  this  group. 

"My  sample  of  nitro-mannite  kept  in  a  glass  tube,  generally  in  the  dark,  has  suf- 
fered some  decomposition ;  acid  fumes  have  been  given  off,  but  the  action  has  nut  pro- 
ceeded far. 

•'  Sugar  Compound. — It  is  well  known  that  cane-sugar  submitted  to  the  action  of 
mixed  nitric  and  sulphuric  acids  is  converted  into  a  pasty  exp1o.»ive  substance,  readily 
soluble  in  alcohol,  but  insoluble  in  water,  to  which,  however,  it  communicates  an  in- 
tensely bitter  flavor.  According  to  the  observations  of  H.  Vohl,  several  different 
compounds  are  produced  simultaneously  in  this  reaction.  Diabetic  sugar  similarly 
treated  gives  a  similar  substance. 

"  I  have  kept  samples  of  this  product,  some  of  which  had  been  merely  kneaded  with 
water  until  the  acid  was  removed,  others  regained  from  solution  in  alcohol.  They 
have  shown  little  signs  of  decomposition. 

"  Milk-Sugar  Compound. — By  the  same  treatment  a  substance  is  obtained  from  milk- 
sugar  closely  resembling  that  just  described.  Like  the  previous  compound,  it  can  be 
purified  by  solution  in  alcohol,  but  does  not  present  itself  in  a  crystalline  form. 

"A  sample  kept  in  paper  was  found  to  be  much  decomposed. 

"  Caramel  Compound. — I  procured  a  similar  compound  from  pure  caramel,  prepared 
by  means  of  absolute  alcohol.  The  caramel  having  been  dried  and  pounced,  was 
placed  in  fuming  nitric  acid  :  it  dissolved ;  upon  the  addition  of  sulphuric  acid,  a  dark- 
colored  oil  separated,  which  became  hard  and  yellow  when  washed  with  water.  It 
was  soluble  in  alcohol,  but  came  out  from  solution  without  crystallizing,  and  always 
of  the  same  color.  The  compound  bore  a  close  resemblance  in  its  various  properties 
to  those  obtained  from  sugar. 

"The  sample  kept  by  me  has  suffered  little  or  no  alteration. 

"  6v,m  Compound. — At  least  two  different  substances  of  this  explosive  character  may 
be  produced  by  the  action  of  nitric  acid  on  gum.  If  the  gum  be  treated  with  the  fuming 
acid,  it  dissolves  into  a  mucilaginous  solution,  from  which  water  precipitates  a  white 
body,  slightly  soluble  in  that  liquid,  and  very  soluble  in  alcohol.  A  sample  of  this 
substance  has  not  yet  suffered  any  decomposition. 

"  If  sulphuric  acid  be  added  to  the  solution  of  gum  in  fuming  acid,  it  precipitates  a 
white  substance  resembling  that  from  sugar,  but  not  nearly  so  soluble  in  alcohol,  and 
very  slightly  in  ether.  Moreover,  it  is  only  softened,  not  melted,  by  a  temperature  of 
212^  Fahr.     No  specimen  of  this  compound  was  preserved. 

"  While  treating  upon  this  subject,  it  may  not  be  amiss  to  append  a  few  observations 
upon  another  decomposition  of  pyroxyline.  When  good  gun-cotton  is  heated  at  a  tempe- 
rature a  little  exceeding  that  of  boiling  water,  it  becomes  brown  in  color,  and  is  disin- 
tegrated. The  odor  of  nitrous  fumes,  along  with  that  of  some  cyanogen  compound, 
is  very  perceptible.  It  thus  becomes  explosive  at  a  lower  temperature  than  formerly, 
a  fact  which  may  account  for  some  of  those  hitherto  unexplained  accidents  which  have 
•risen  from  this  article,  for  it  is  evident  that  gun-cotton  exposed  for  some  time  to  a 


CRANES  (TUBULAR).  549 

degree  of  heat  quite  insufficient  under  ordinary  circumstances  to  cause  explosion,  may 
yet  be  eventually  dissipated  from  the  formation  of  this  product 

"The  brown  substance  thus  obtained  underwent  no  visible  alteration  in  the  space  of 
foiir  jrears.  When  examined  lately  it  was  found  to  be  very  soluble  in  water,  but  insol- 
uble in  alcohol  or  ether.  Its  aqueous  solution  tasted  somewhat  bitter,  it  reacted 
slightly  acid,  no  crystals  were  obtained  on  evaporation.  When  boiled  with  a  solution 
of  potash,  it  evolved  ammonia.  When  mixed  with  a  salt  of  lead  or  copper  it  formed 
brown  floceulent  precipitates,  but  none  appeared  with  a  silver  or  lime  salt  The  organic 
substance  which  fell  in  combination  with  oxide  of  lead,  contained  a  large  amount  of 
nitrogen.  That  portion  of  the  fibre  which  had  not  become  brown  with  heat  was  found 
to  be  no  longer  pyroxyline ;  when  freed  from  the  brown  matter  by  washing  with  water, 
and  dried,  it  left  little  residue  on  explosion;  but  on  the  other  hand,  it  dissolved  very 
readily  m  ether,  alcohol,  or  cold  sulphuric  acid ;  properties  of  cotton-xyloidine,  but  not  of 
the  original  substance.  When,  however,  the  manner  of  its  production  is  considered,  we 
can  hardly  conceive  it  identical  with  a  body  which  would  require  the  introduction  of  two 
atoms  of  hydrogen  if  formed  from  pyroxyline.  Whether  this  change  which  gun-cotton 
undergoes  at  a  high  temperature  is  at  all  analogous  to  the  spontaneous  decomposition 
mentioned  above,  can  scarcely  be  determined,  but  the  presence  of  azotized  compounds 
m  considerable  quantity,  and  of  ammonia,  rather  indicates  the  reverse. 

"  The  rationale  of  these  decompositions  is  far  from  being  elucidated  by  the  observations 
here  recorded,  but  as  the  substances  themselves  are  not  now  in  existence,  nor  are  capable 
of  being  procured  without  long  delay,  I  cannot  pursue  the  investigation  further  The 
only  general  conclusion  which  can  be  drawn  appears  to  be,  that  several  substances  of 
the  character  above  described  have  a  tendency  to  suffer  spontaneous  decomposition  from 
being  oxidized  into  non-azotized  acids  at  the  expense  of  the  peroxide  of  nitrogen  NO^. 
they  contain,  which  is  reduced  to  the  condition  of  nitric  oxide,  NO2,  and  evolved  as  such, 
a  portion  of  water  being  always  given  off  at  the  same  time." 

COURT  PLASTER  is  a  considerable  object  of  manufacture.  It  is  made  aa 
follows: 

Black  silk  is  strained  and  brushed  over  ten  or  twelve  times  with  the  following  pre- 
paration:— Dissolve  I  an  ounce  of  balsam  of  benzoin  in  6  ounces  of  rectified  spirite  of 
wme;  and  in  a  separate  vessel  dissolve  1  ounce  of  isinglass  in  as  little  water  as  may  be. 
Strain  each  solution,  mix  them,  and  let  the  mixture  rest  so  that  any  undissolved  parU 
may  subside;  when  the  clear  liquid  is  cold  it  will  form  a  jelly,  which  must  be  warmed 
before  It  is  applied  to  the  silk.  When  the  silk  coated  with  it  is  quite  dry  it  must  be 
linished  off  with  a  coat  of  a  solution  of  4  ounces  of  Chian  turpentine  in  6  ounces  of 
tincture  of  benzoin,  to  prevent  its  cracking.* 

COW  DUNG  SUBSTITUTE,  in  calico  printing.  Sulphate,  carbonate  and  phos- 
pnate  of  hme  and  soda.  ^ 

CRANES,  Tubular,  of  Mr.  W.  Fairbairn.^AmoTig  the  many  happy  applica- 
tions of  the  hollow-girder  system  of  our  great  engineer,  this  is  one  of  the  most  inee- 
nious.  ° 

"  Ktg.  425  is  a  vertical  section  of  a  crane,  constructed  according  to  my  said  invention 
and  calculated  for  lifting  or  hoisting  weights  up  to  about  8  ton&    Fig.  426  is  an 
elevation  of  the  same;  fgs.  427,  428,  429,  and  430,  are  cross-sections,  on  the  lines  a  b 
cd,ef,gh;  andjig.  431  a  transverse  vertical  section  on  the  line  ik.     a  a  is  the  jib  which 
in  Its  general  outline,  is  of  a  crane-neck  form,  but  rectangular  in  its  cross-section  as 
particularly  shown  m  Jig.t.  428,  429,  and  430.     The  four  sides  are  formed  of  metal 
plates,  firmly  riveted  together.     Along  the  edges  the  connection  of  the  plates  is  effected 
by  means  of  pieces  of  angle  iron.    The  connections  of  the  plates  at  the  cross-joints 
on  the  convex  or  upper  side  of  the  jib,  are  made  by  the  riveting  on  of  a  plate,  which 
covers  or  overlaps  the  ends  of  the  two  plates  to  be  joined;  the  riveta  at  this  part  are 
disposed  as  represented  m  /^.  432  (a  plan  of  the  top  plates),  and  known  as  'chain 
riveting;   b  b  is  the  pillar,  which  is  firmly  secured  by  a  base  plate  p,  to  a  stone  founda- 
tion b;    and  fits  at  top  into  a  cup-shaped  bearing  c,  which  is  so  firmly  secured  to 
the  side  plates  of  the  jib  at  or  near  to  the  point  where  the  curvature  commences,  and 
on  which  bearing  the  jib  is  free  to  revolve.     Fig.  431  is  a  transverse  vertical  section 
of  the  lower  part  of  the  jib,  showing  the  manner  of  fitting  the  bearings  for  the  chain- 
barrel  (which  is  placed  m  the  interior),  and  the  spindles  and  shafts  of  the  wheel-geering. 
by  which  the  power  is  applied  there  to  d,  is  the  chain  pulley,  which  is  inserted  in  an 
aperture  formed  in  the  top  of  the  jib.     The  chain  passing  over  this  pulley,  enters  the 
interior  of  the  crane,  and  is  continued  down  to  the  chain  barrel,     e  is  a  pulley  or  roller, 
which  IS  interposed  about  half-way  between  the  chain-pulley  and  the  chain-barrel,  for 
the  purpose  of  preventing  the  chain  rubbing  against  the  plates.     J^g.  433  is  a  plan  of 
the  lower  platea 

^ParUI  Pharmacologia. 


550 


CRANES  (TUBULAR). 


Mg.  484  is  a  vertical  section  of  another  crane  constructed  upon  the  same  principle 
as  that  just  described,  but  calculated  for  lifting  ranch  greater  weights  (says  20  tons); 
it  diflfers  in  having  the  lower  or  concave  side  a  a,  of  the  jib  strengthened  by  means  of 
three  additional  plates  b  b  b,  whereby  the  interior  is  divided  into  one  large  and  three 
smaller  cells,  as  shown  in  Jigs.  435  and  436,  which  are  cross  sections  upon  the  lines  a  b, 


425 


f 


483 


482 


»GO*Oo«ftO 


ft  '-o&c.ftA.TTTYTrf^TjflCfct,  4»Aietoa<6A*c*>(*cb*,tc''-t^vV 


and  c  <f  of  fig.  484.  This  arrangement  of  the  cells  to  strengthen  the  lower  or  concave 
side  is  advisable,  in  order  to  obtain  sufficient  resistance  to  the  compression  exerted  by 
the  load  lifted,  without  unnecessarily  increasing  the  weight  of  the  other  part*. 
The  tension  exerted  upon  the  upper  or  convex  plates  does  not  require  so  m\ich  ma- 
terials to  withstand  it;  c,  is  the  toe  of  the  jib,  which  rests  in  a  step  formed  in  the  bot- 
tom of  the  cylindrical  castings  d,  which  is  built  into  the  masonry  forming  the  basis  of 
the  machine,  e  e  are  two  of  a  set  of  pulleys,  which  are  mounted  between  two  rings  ff, 
and  serve  an  anti-friction  rollers  for  the  upper  bearing  of  the  jib.  The  lowermost  of  tlie 
rings  F  F,  rests  upon  a  set  of  rollers  o  g,  which  are  fitted  into  the  top  of  the  casting  d, 
■o  that  as  the  jib  is  turned  round,  the  rings  f  f,  and  the  anti-friction  rollers  which  they 
carry,  have  perfect  freedom  to  move  along  with  it ;  h  is  a  platform,  upon  which  the 
persons  working  the  machine  may  stand,  and  which  supports  a  column  i,  within  which 
there  is  mounted  a  spindle  k,  the  lower  end  of  which  has  keyed  to  it  a  pinion  l,  which 
gears  into  a  circular  rack  m  m,  bolted  to  the  top  of  the  cylindrical  casing  d.  n  is  a 
worm-wheel  keyed  to  the  top  of  the  spindle  k,  into  which  an  endless  screw,  worked  by 


CRAPE. 


551 


a  hand-wheel,  is  geered,  so  that,  by  turning  the  hand-wheel,  the  jib  of  the  crane  is  made 
to  move  round  in  any  required  direction,  o  is  the  chain-barrel ;  p  the  chain-wheel ; 
B  R  pulleys  or  rollers  which  support  the  chain,  and  prevent  its  rubbing  against  the  plates 
of  the  jib. 

"In  the  cranes  and  hoisting  machines  which  I  have  described,  the  chain-barrels  are 
inclosed  within  the  jib,  and  the  spindles  of  the  wheel-gearing  are  also  inside ;  and  this 


is  the  disposition  of  those  parts,  which  I  prefer ;  but  it  will  be  obvious  that  they  may  be 
also  placed  outside  of  the  jib,  in  a  manner  similar  to  that  generally  followed  in  the  con- 
struction of  ordinary  cranes.  And  having  now  described  my  said  invention,  and  in 
what  manner  the  same  is  to  be  performed,  I  declare  that  what  I  claim  is  the  construc- 
tion of  cranes  and  other  light  lifting  or  hoisting  machines,  with  jibs  composed  of  a  series 
of  metal  plates,  arranged  and  combined  so  as  to  form  a  connected  series  of  tubular  or 
cellular  compartments,  as  before  exemplified  and  described." 

CRAPE  {CrSpe,  Fr.;  Krepp,  Germ.)  A  transparent  textile  fabric,  somewhat 
like  gauze,  made  of  raw  silk,  gummed  and  twisted  at  the  mill.  It  is  woven  with  any 
crossing  or  tweel.  When  dyed  black,  it  is  much  worn  by  ladies  as  a  mourning  dress. 
Crapes  are  crisped  {crepes)  or  smooth ;  the  former  being  double,  are  used  in  close 
mourning,  the  latter  in  less  deep.  White  crape  is  appropriate  to  young  unmarried 
females,  and  to  virgins  on  taking  the  veil  in  nunneries.  The  silk  destined  for  the 
first  is  spun  harder  than  for  the  second ;  since  the  degree  of  twist,  particularly  for  the 
warp,  determines  the  degree  of  crisping  which  it  assumes  after  being  taken  from  the 
loom.     It  is  for  this  purpose  steeped  in  clear  water,  and  rubbed  with  prepared  wax. 


U 


SS2 


CRAYONS. 


Crapes  are  all  wc  vcn  and  dyed  with  the  silk  in  the  raw  state.    They  are  finished  with 
a  stmening  of  gum  water. 

Crnpe  is  a  Bolognese  invention,  but  has  been  long  manufactured  with  superior 
excellence  at  Lyons  in  France,  and  Norwich  in  England.  There  is  now  a  magnificent 
fabric  of  it  at  Yarmouth,  by  power-loom  machinery. 

There  is  another  kind  of  stuff,  called  crepon,  made  either  of  fine  wool,  or  of  wool  and 
silk,  of  which  the  warp  is  twisted  much  harder  than  the  weft  The  crepons  of  Naples 
consist  altogether  of  silk.  '^ 

CRAYONS.  (Eng.  and  Fr.;  Pastehtifte,  Germ.)  Slender,  soft,  and  somewhat 
friable  cylinders,  variously  colored  for  delineating  figures  upon  paper,  usually  called 
chalk  drawings.  Red,  green,  brown,  and  other  colored  crayons,  are  made  with  fine 
pipe  or  china  clay  paste,  intimately  mixed  with  earthy  or  metallic  pigments,  or  in 
general  with  body  or  surface  colors,  then  moulded  and  dried.  The  brothers  Joel,  in 
Paris,  employ  as  crayon  cement  the  following  composition:  6  parts  of  shellac,  4  parts 
of  spirit  of  wme,  2  parts  of  turpentine,  12  parts  of  a  coloring  powder,  such  as  Prussian- 
blue,  orp.  men  t,  white  lead,  vermilion,  &c.,  and  12  parts  of  blue  clay.  The  clay  beine 
elutriated  passed  through  a  hair  sieve,  and  dried,  is  to  be  well  incorporated  by  tritu. 
ration  with  the  solution  of  the  sheUac  in  the  spirit  of  wine,  the  turpentine,  and  the 
pigment ;  and  the  doughy  mass  is  to  be  pressed  in  proper  moulds,  so  as  to  acquire  the 
desired  shape.     They  are  then  dried  by  a  stove  heat. 

In  order  to  make  cylindrical  crayons,  a  copper  cylinder  is  employed,  about  2  inches 
m  diameter,  and  1|  inches  long,  open  at  one  end,  and  closed  at  the  other  with  a  per- 
lorated  plate,  containing  holes  corresponding  to  the  sizes  of  the  crayons.  The  paste  is 
introduced  into  the  open  end,  and  forced  through  the  holes  of  the  bottom  by  a  piston 
moved  by  a  strong  press.  The  vermicular  pieces  that  pass  through  are  cut  to  the 
proper  lengths,  and  dried.  As  the  quality  of  the  crayons  depends  entirely  upon  the 
tineness  of  the  paste,  mechanical  means  must  be  resorted  to  for  effecting  this  object  ii 
the  best  manner.    The  following  machine  has  been  found  to  answer  the  purpose  exceed 


^Flg.m  18  a  vertical  section  through  the  centre  of  the  crayon  mill.  Fig,  438  is  a 
view  of  the  mill  from  above,  a,  the  mill  tub,  whose  bottom  b  must  be  a  hard  flat  plate 
of  ca«t  iron  ;  the  sides  a  being  of  wood  or  iron  at  pleasure.  In  the  centre  of  the  bottom 
there  is  a  pivot  c.  screwed  into  a  socket  cast  upon  the  bottom,  and  which  may  be 
•trengthened  by  two  cross  bars  d.  made  fast  to  the  frame  e.  f,  the  millstone  of  cast- 
iron,  concave  whose  diameter  18  considerably  smaller  than  that  of  the  vessel  a:  it  is 
furnished  within  wi  h  a  circular  basin  of  wood  g,  which  receives  the  materials  to  be 
ground,  and  directs  them  to  the  holes  h,  which  allow  them  to  pass  down  between  the 
under  part  of  the  miiller,  and  the  bottom  of  the  tub.  to  undergo  trituration. 

JJj  the  centrifugal  motion,  the  paste  is  driven  toward  the  sides  of  the  vessel  risei 


\ 


CREOSOTE. 


553 


oyer  the  sides  of  the  muller,  and  comes  again  through  the  holes  n,  so  as  to  be  repeatedly 
■ubjected  to  the  grinding  operation.  This  millstone  is  mounted  upon  an  upright  shaft 
I,  which  receives  rotary  motion  from  the  bevel-wheel  work  k,  driven  by  the  winch  l. 

The  furnace  in  which  some  kinds  of  crayons,  and  especially  the  factitious  black-lead 
pencils,  are  baked,  is  represented  in^^r.  439,  in  a  front  elevation;  .and  in^^r.  440,  which 
18  a  vertical  section  through  the  middle  of  the  chimney. 

A  A,  six  tubes  of  greater  or  less  size,  according  as  the  substance  of  the  crayons  is  a 
better  or  worse  conductor  of  heat.  These  tubes,  into  which  the  crayons  intended  for 
baking  are  to  be  put,  traverse  horizontally  the  laboratory  b  of  the  furnace,  and  are  sup- 
ported by  two  plates  c,  pierced  with  six  square  holes  for  covering  the  axes  of  the  tubes 
A.  These  two  plates  are  hung  upon  a  common  axis  d;  one  of  them,  with  a  ledge,  shuts 
the  cylindrical  part  of  the  furnace,  as  is  shown  in  the  figure.  At  the  extremity  of  the 
bottom,  the  axis  d  is  supported  by  an  iron  fork  fixed  in  the  brickwork;  at  the  front  it 
crosses  the  plate  c,  and  lets  through  an  end  about  4  inches  square  to  receive  a  key,  by 
means  of  wiiif;h  the  axis  d  may  be  turned  round  at  pleasure,  and  thereby  the  two  plates 
c,  and  the  six  tubes  a,  are  thus  exposed  in  succession  to  the  action  of  the  fire  in  an 
equal  manner  upon  each  of  their  sides.  At  the  two  extremities  of  the  furnace  are  two 
chimneys  e,  for  the  purpose  of  diffusing  the  heat  more  equably  over  the  body  of  the 
crayons,  f,  Jig.  439,  is  the  door  of  the  fire-place,  by  which  the  fuel  is  introduced ;  o, 
fig.  440,  the  ash-pit ;  h,  the  fire-place ;  i,  holes  of  the  grate  which  separate  the  fire-place 
irom  the  ash-pit ;  k,  brickwork  exterior  to  the  furnace. 

General  Lomet  proposes  the  following  composition  for  red  crayons.  He  takes  the 
softest  hematite,  grinds  it  upon  a  porphyry  slab,  and  then  carefully  elutriates  it  He 
makes  it  into  a  plastic  paste  with  gum  arabic  and  a  little  white  soap,  which  he  forms 
by  moulding,  as  above,  through  a  syringe,  and  drying,  into  crayons.  The  proportions 
of  the  ingredients  require  to  be  carefully  studied. 

Crayons,  lithographic.  Various  formulae  have  been  given  for  the  formation  of  these 
crayons.  One  of  these  prescribes,  white  wax,  4  parts ;  hard  talloAv-soap,  shellac,  of 
each  2  parts;  lamp  black,  1  part.  Another  is,  dried  tallow  soap  and  white  wax,  each 
6  parts  ;  lamp  black,  1  part  This  mixture  being  fused  with  a  gentle  heat,  is  to  be  cast 
into  moulds  for  forming  crayons  of  a  proper  size. 

CREOSOTE,  or  the  Jlesh-preserver,  from  xpcns  and  erw^w,  is  the  most  important  of  the 
five  new  chemical  products  obtained  from  wood  tar  by  Dr.  Reichenbach.  The  other  four, 
paraffi.ne,  eupione,  picamar,  and  pitiacal,  have  hitherto  been  applied  to  no  use  in  the  arts, 
and  may  be  regarded  at  present  as  mere  analytical  curiosities. 

Creosote  may  be  prepared  either  from  tar  or  from  crude  pyroligneous  acid.  The  tar 
must  be  dij;tilled  till  it  acquires  the  consistence  of  pitch,  and  at  the  utmost  till  it  begins 
to  exhale  th^  white  vapors  of  paraffine.  The  liquor  which  passes  into  the  receiver 
divides  itself  into  3  strata,  a  watery  one  in  the  middle,  placed  between  a  heavy  and  a  light 
oil.     The  lower  stratum  alone  is  adapted  to  the  preparation  of  creosote. 

1.  The  liquor,  beins  saturated  with  carbonate  of  potash,  is  to  be  allowed  to  settle,  and 
the  oily  matter  which  floats  at  top  is  to  be  decanted  off.  When  this  oil  is  distilled,  it 
affords,  at  first,  products  lighter  than  water,  which  are  to  be  rejected,  but  the  heavier  oil 
which  follows  is  to  be  separated,  washed  repeatedly  by  agitation,  with  fresh  portions  of 
dilute  phosphoric  acid,  to  free  it  from  ammonia,  then  left  some  time  at  rest,  after  which 
it  must  be  washed  by  water  from  all  traces  of  acidity,  and  finally  distilled  along  with 
a  new  portion  of  dilute  phosphoric  acid,  taking  care  to  cohobate,  or  pour  baik  the  dis- 
tilled product  repeatedly  into  the  retort. 

2.  The  oily  liquid  thus  rectified  is  colorless ;  it  contains  much  creosofe,  but  at  the 
same  time  some  eupioiie,  &c.  It  must  therefore  be  mixed  with  potash  ley  at  1*12  sp. 
grav.,  which  dissolves  the  creosote.  The  upione  floats  upon  the  surface  of  that  solution, 
and  may  be  decanted  off.  The  alkaline  solution  is  to  be  exposed  to  the  air,  till  it 
Blackens  by  decomposition  of  some  foreign  matter.  The  potash  being  then  saturated 
with  dilute  sulphuric  acid,  the  creosote  becomes  free,  when  it  may  be  decanted  or 
syphoned  off  and  distilled. 

8.  The  treatment  by  potash,  sulphuric  acid,  &c.,  is  to  be  repeated  upon  the  brownish 
creosote  till  it  remains  colorless,  or  nearly  so,  even  upon  exposure  to  air.  It  most  be 
now  dissolved  in  the  strongest  potash  ley,  subjected  to  distillation  anew,  and,  lastly,  re- 
distilled wiih  the  rejection  of  the  first  products  which  contain  much  water,  retaining  only 
the  following,  but  taking  care  not  to  push  the  process  too  far. 

In  operating  upon  pyroligneous  acid,  if  we  dissolve  eflloresced  sulphate  of  soda  in  it  to 
saturation,  at  the  temperature  of  167°  F.,  the  creosote  oil  will  separate,  and  float  upon 
the  surface.  It  is  to  be  decanted,  left  in  repose  for  some  days,  during  which  it  will  part 
with  a  fresh  portion  of  the  vinegar  and  salt.  Being  now  saturated  while  hot,  with  car- 
bonate of  potash,  and  distilled  with  water,  an  oily  liquor  is  obtained,  of  a  pale  yellow 
color.  This  is  to  be  rectified  by  phosphoric  acid,  &c.,  like  the  crude  product  of  creosote 
from  tar. 


554 


CRUCIBLES. 


Creosote  is  apparently  composed  of  76'2  carbon,  1'8  hydrogen,  and  16*0  oxygen,  in 
100  parts.  It  is  an  oily-looking  liquid,  slightly  greasy' to  the  touch,  void  of  coloi: 
•end  burning  taste,  and  capable  of  corroding  the  epidermis  in  a  short  time.  It  possesses 
a  penetrating  disagreeable  smell,  like  that  of  highly  smoked  hams,  and,  when  inhaled  up 
the  nostrils,  causes  a  flow  of  tears.  Its  specific  gravity  is  1-037,  at  58**  F.  Its  consist- 
cnce  is  similar  to  that  of  oil  of  almonds.  It  has  no  action  upon  the  colors  of  litmus  oi 
turmeric,  but  communicates  to  white  paper  a  stain  which  disappears  spontaneously  in  i 
few  hours,  and  rapidly  by  the  application  of  heat. 

It  boils  without  decomposition  at  398°  F.,  under  the  average  barometric  prefsure, 
remains  fluid  at  16°  F.,  is  a  non-conductor  of  electricity,  refracts  light  powerfully,  and 
burns  in  a  lamp  with  a  ruddy  smoky  flame. 

When  mixed  with  water  at  58°  F.  it  forms  two  different  combinations,  the  first  being  a 
solution  of  1  part  of  creosote  in  400  of  water;  the  second,  a  combination  of  1  part  of 
water  with  10  parts  of  creosote.  It  unites  in  all  proportions  with  alcohol,  hydric  ether, 
acetic  ether,  naptha,  eupione,  carburet  of  sulphur,  &c. 

Creosote  dissolves  a  large  quantity  of  iodine  and  phosphorus,  as  also  of  sulphur  with 
the  aid  of  heat,  but  it  deposites  the  greater  part  of  them  in  crystals,  on  cooling.  It  com- 
bines with  potash,  soda,  ammonia,  lime,  baryta,  and  oxyde  of  copper.  Oxyde  of  mercury 
converts  creosote  into  a  resinous  matter,  while  itself  is  reduced  to  the  metallic  state. 
Strong  sulphuric  and  nitric  acids  decompose  it. 

Creosote  dissolves  several  salts,  particularly  the  acetates,  and  the  chlorides  of  calcium 
and  tm ;  it  reduces  the  nitrate  and  acetate  of  silver.  It  also  dissolves  indigo  blue ;  a 
remarkable  circumstance.  Its  action  upon  animal  matters  is  very  interesting.  It  coagu- 
lates albumen,  and  prevents  the  putrefaction  of  butchers'  meat  and  fish.  For  this  pur- 
pose these  substances  must  be  steeped  a  quarter  of  an  hour  in  a  weak  watery  solution  of 
creosote,  then  drained  and  hung  up  in  the  air  to  dry.  Hence  Reichenbach  has  inferred 
that  it  is  owing  to  the  presence  of  creosote  that  meat  is  cured  by  smoking ;  but  he  is  not 
correct  in  ascribing  the  effect  to  the  mere  coagulation  of  the  albumen,  since ^6n«e  alone, 
without  creosote,  will  putrefy  in  the  course  of  24  hours,  during  the  heats  of  summer.  It 
kills  plants  and  small  animals.    It  preserves  flour  paste  unchanged  for  a  long  time. 

Creosote  exists  in  the  tar  of  beech- wood,  to  the  amount  of  from  20  to  25  per  cent.,  and 
in  crude  pyroligneous  acid,  to  that  of  1|. 

It  ought  to  be  kept  in  well-stoppered  bottles,  because  when  left  open  it  becomes  pro- 
gressively yellow,  brown,  and  thick. 

Creosote  has  considerable  power  upon  the  nervous  system,  and  has  been  applied  to  the 
teeth  with  advantage  in  odontalgia,  as  well  as  to  the  skin  in  recent  scalds.  But  its  me- 
dicinal and  surgical  virtues  have  been  much  exaggerated.  Its  flesh-preserving  quality 
is  rendered  of  little  use,  from  the  difficulty  of  removing  the  rank  flavor  which  it 
imparts. 

Having  been  employ^ed  by  a  chemical  manufacturer  to  examine  his  creosote,  and  com- 
pare it  with  others  with  a  view  to  the  improvement  of  his  process,  I  found  that  the 
article,  as  made  by  eminent  houses,  diflfered  considerably  in  its  properties. 

The  specific  gravities  varied  in  the  several  specimens  as  follows :  1,  a  specimen  given 
rae  by  Messrs.  Zimmer  and  Sell,  at  their  factory  in  Sachsenhausen,  by  Frankfort-on-the- 
Maine,  had  a  specific  gravity  of  1*0524;  2,  a  sample  made  in  the  north  of  England,  sp. 
gr.  1057,  and  its  boiling  point  varied  from  370^  to  380°  Fahr.  Mr.  Morson's  creosote, 
which  is  much  esteemed,  has  a  sp.  gr.  of  1*070,  and  boils  first  at  280°,  but  progres- 
sively rises  in  temperature  up  to  420°,  when  it  remains  stationary.  The  German  creo- 
sote was  distilled  from  the  tar  of  the  pyrolignous  acid  manufacture.  Creosote,  I  believe, 
is  often  made  from  Stockholm  tar.  Berzelius  gives  the  sp.  gr.  of  creosote  at  r0S7,  and 
its  boiling  point  at  203°  C.=-397-4°  F.  I  deemed  it  useless  to  subject  to  ultimate  analy- 
sis products  differing  so  considerably  in  their  physical  properties.  They  were  all  very 
soluble  in  potash  lye. 

CROSS-FLLTCKANS  or  FLOOKANS.  The  name  given  by  the  Cornish  miners  to 
clay  veins  of  more  ancient  formation. 

CRUCIBLES  {Creu»ets,  Fr. ;  Schmelztiegel,  Germ.)  are  small  conical  vessels,  narrower 
at  the  bottom  than  the  mouth,  for  reducing  ores  in  docimasy  by  the  dry  analysis,  for 
fusing  mixtures  of  earthy  and  other  substances,  for  melting  metals,  and  compounding 
metallic  alloys.  They  ought  to  be  refractory  in  the  strongest  heats,  not  readily  acted 
upori  by  the  substances  ignited  in  them,  not  porous  to  liquids,  and  capable  of  bearing 
considerable  alternations  of  temperature  without  cracking;  on  which  account  they 
should  not  be  made  too  thick.  The  best  crucibles  are  formed  from  a  pure  fire-clay, 
mixed  with  finely-ground  cement  of  old  crucibles,  and  a  portion  of  black-lead  or  gra- 
phite. Some  pounded  coke  may  be  mixed  with  the  plumbago.  The  clay  should  be 
prepared  in  a  similar  way  as  for  making  pottery  ware;  the  vessels  after  being  formed 
must  be  slowly  dried,  and  then  properly  baked  in  the  kiln.  Crucibles  formed  of  a 
mixture  of  8  parts  in  bulk  of  Stourbridge  clay  and  cement,  6  of  coke,  and  4  of  graphite, 


CRYSTAL. 


555 


have  been  found  to  stand  28  meltings  of  76  pounds  of  iron  each,  in  the  Royal  Berlin 
foundry.  Such  crucibles  resisted  the  greatest  possible  heat  that  could  be  produced,  in 
which  even  wrought  iron  was  melted,  equal  to  150°  or  155°  Wedge  wood ;  and  bore 
sudden  cooling  without  cracking.  Another  composition  for  brass-founding  crucibles  ia 
the  following:  j^  Stourbridge  clay;  \  burned-clay  cement;  |  coke  powder;  \  pipe  clay. 
The  pasty  mass  must  be  compressed  in  moulds.  The  Hessian  crucibles  from  Great  Al- 
merode  and  Epeterode  are  made  from  a  fire-clay  which  contains  a  little  iron,  but  no 
lime ;  it  is  incorporated  with  siliceous  sand.  The  dough  is  compressed  in  a  mould, 
dried,  and  strongly  kilned.  They  stand  saline  and  leaden  fluxes  m  docimastic  opera- 
tions very  well ;  are  rather  porous  on  account  of  the  coarseness  of  the  sand,  but  are 
thereby  less  apt  to  crnck  from  sudden  heating  or  cooling.  They  melt  under  the  fusing 
point  of  bar  iron.  Benufoy  in  Paris  has  lately  succeeded  in  making  a  tolerable  imita- 
tion of  the  Hessian  crucibles  with  a  fire-clay  found  near  Namur  in  the  Ardennes. 

Berthier  has  published  the  following  elaborate  analyses  of  several  kinds  of  cruci* 
Nes: — 


Hescian. 

Beaufay. 

English  for 

St.  Etienn(> 
for 

GlasB  Pots 

Bohemian 

Glass  Pote 

Cast  Steel. 

Cast  Stee]. 

at  Nemours 

Glass  Puts. 

of  Creusot. 

Silica     -    -    - 

70-9 

64-6 

63-7 

65-2 

67-4 

68-0 

680 

Alumina     -    - 

24-8 

34-4 

20-7 

25-0 

32-0 

29-0 

280 

Oxyde  of  Iron  - 

3-8 

1-0 

4-0 

7-2 

0-8 

2-2 

2-0 

Magnesia    -     - 

trace 

— 

-- 

trace 

trace 

0-5 

trace 

Water    -    -    - 

— 

— 

10-3  • 

— 

— 

— 

10 

Wurzer  states  the  composition  of  the  sand  and  clay  in  the  Hes6i&n  crucibles  as  fol- 
lows : — 

Clay;  silica  10*  1 ;  alumina  65-4;  oxydes  of  iron  and  manganese  1*2;  lime  0-3;  water  23 
Sand;  95-6  2-1  1-5  0-8 

Black  had  crucibles  are  made  of  two  parts  of  graphite  and  one  of  fire  clay  ;  mixed 
with  water  into  a  paste,  pressed  in  moulds,  and  well  dried ;  but  not  baked  hard  in  the 
kiln.  They  bear  a  higher  heat  than  the  Hessian  crucibles,  as  well  as  sudden  changes  of 
temperature ;  have  a  smooth  surface,  and  are  therefore  preferred  by  the  mellers  of  gold 
and  silver.    This  compound  forms  excellent  small  or  portable  furnaces. 

Mr.  Anstey  describes  his  patent  process  for  making  crucibles,  as  follows :  Take  two 
parts  of  fine  ground  raw  Stourbridge  clay,  and  one  part  of  the  hardest  gas  coke,  pre- 
viously pulverized,  and  sifted  through  a  sieve  of  one  eighth  of  an  inch  mesh  (if  the 
coke  is  ground  too  fine  the  pots  are  very  apt  to  crack).  Mix  the  ingredients  together  with 
the  proper  quantity  of  water,  and  tread  the  mass  well.  The  pot  is  moulded  by  hand  upon 
a  wooden  block,  supported  on  a  spindle  which  turns  in  a  hole  in  the  bench ;  there  is  a 
gauge  to  regulate  the  thickness  of  the  melting  pot,  and  a  cap  of  linen  or  cotton  placed 
wet  upon  the  core  before  the  clay  is  applied,  to  prevent  the  clay  from  sticking  partially 
to  the  core,  in  the  taking  off;  the  cap  adheres  to  the  pot  only  while  wet,  and  may  be 
removed  without  trouble  or  hazard  when  dry.  He  employs  a  wooden  bat  to  assist  in 
moulding  the  pot ;  when  moulded,  it  is  carefully  dried  at  a  gentle  heat.  A  pot  dried  as 
above,  when  wanted  for  use,  is  first  warmed  by  the  fire-side,  and  is  then  laid  in  the  fur- 
nace with  the  mouth  downwards  (the  red  cokes  being  previously  damped  with  cold 
ones  in  order  to  lessen  the  heat)  ;  more  coke  is  then  thrown  in  till  the  pot  is  covered, 
and  it  is  now  brought  up  gradually  to  a  red  heat.  The  pot  is  next  turned  and  fixed  in  a 
proper  position  in  the  furnace,  without  beine  allowed  to  cool,  and  is  then  charged  with 
cold  iron,  so  that  the  metal,  when  melted,  shall  have  its  surface  a  little  below  the  mouth 
of  the  pot.  The  iron  is  melted  in  about  an  hour  and  a  half,  and  no  flux  or  addition  of 
any  kind  is  made  use  of.  A  pot  will  last  for  fourteen  or  even  eighteen  successive  melt- 
ings, provided  it  is  not  allowed  to  cool  in  the  intervals;  but  if  it  cool,  it  will  probably 
crack.  These  pots,  it  is  said,  can  bear  a  greater  heat  than  others  without  softening,  and 
will,  consequently,  deliver  the  metal- in  a  more  fluid  state  than  the  best  Birmingham  pots 
will.     See  a  figure  of  the  crucible  mould  under  Steel. 

CRYSTAL  is  the  geometrical  form  possessed  by  a  vast  number  of  mineral  and  saline 
substances;  as  also  by  many  vegetable  and  animal  products.  The  integrant  particles  of 
matter  have  undoubtedly  determinate  forms,  and  combine  with  one  another,  by  the 
attraction  of  cohesion,  according  to  certain  laws,  and  points  of  polarity,  whereby  they 
assume  a  vast  variety  of  secondary  crystalline  forms.  The  investigation  of  these  laws 
belongs  to  crystallography,  and  is  foreign  to  the  practical  purpose  of  this  volume. 

*  This  cnictble  had  been  analyzed  before  being  baked  in  tlie  kiln. 


556 


CURRYING  OF  LEATHER. 


Btmctions  are  given  nncler  each  oWeet  of  manufacture  which  requires  crystallization, 
how  to  conduct  this  proeees.     See  13orax,  Salt,  Ac. 

CUDBEAR  was  first  made  an  article  of  trade  in  this  country,  by  Dr.  Cuthbert 
Gordon,  from  whom  it  derived  its  name,  and  was  originally  manufactured  on  a  great 
scale  by  Mr.  G.  Mackintosh,  at  Glasgow,  nearly  80  years  ago.  Cudbear  or  persio  is  a 
powder  of  a  violet  red  color,  difficult  to  moisten  with  water,  and  of  a  peculiar  but  not 
disagreeable  odor.  It  is  partially  soluble  in  boiling  water,  becomes  red  with  acids,  and 
violet  blue  with  alkalis.  It  is  prepared  in  the  same  way  as  archil,  only  towards  the 
end  the  substance  is  dried  in  the  air,  and  is  then  ground  to  a  fine  powder,  taking  care  to 
avoid  decocnposition,  which  renders  it  glutinous  In  Scotland  they  use  the  lichen  tar- 
tareus,  more  rarely  the  lichen  calcareus,  and  omphalodes ;  most  of  which  lichens  are 
imported  from  Sweden  and  Norway,  under  the  name  of  rock  moss.  The  lichen  is  suffered 
to  ferment  for  a  month,  and  is  then  stirred  about  to  allow  any  stones  which  may  be  pre- 
sent to  fall  to  the  bottom.  The  red  mass  is  next  poured  into  a  flat  vessel,  and  left  to 
evaporate  till  its  urinous  smell  has  disappeared,  and  till  it  has  assumed  an  agreeable 
color  verging  uiMjn  violet.  It  is  then  ground  to  fine  powder.  During  the  fermentation 
of  the  liclien,  it  is  watered  with  stale  urine,  ot  with  an  equivalent  ammoniacal  liquor  of 
any  kind,  as  in  making  archil. 

CUPELLATION  is  a  mode  of  analyzing  gold,  silver,  palladium,  and  platinum,  by 
adding  to  small  portions  of  alloys,  containing  these  metals,  a  bit  of  lead,  fusing  the 
mixture  in  a  little  cup  of  bone  earth  called  a  cupel,  then  by  the  joint  action  of  heat  and 
air,  oxydizing  the  copper,  tin,  &c.,  present  in  the  precious  metals.  The  oxydes  thus  pro- 
duced are  dissolved  and  carried  down  into  the  porous  cupel  in  a  liquid  state,  by  the 
vitrified  oxvde  of  lead.     See  Assay,  Gold,  and  Silver. 

CURRYING  OF  LEATHER  (Corroyer,  Fr. ;  Zurichten,  Germ.)  is  the  art  of 
dressing  skins  after  they  are  tanned,  for  the  purpose  of  the  shoe-maker,  coach  and  harness 
maker,  &c.,  or  of  giving  them  the  necessary  smoothness,  lustre,  color,  and  suppleness. 
The  currier's  shop  has  no  resemblance  to  the  tanner's  premises,  having  a  quite  different 
set  of  tools  and  manipulations. 

The  currier  employs  a  strong  hurdle  about  a  yard  square,  made  either  of  basket  twigs, 
or  of  wooden  spars,  fixed  rectangularly  like  trellis  work,  with  holes  3  inches  square, 
upon  which  he  treads  the  leather,  or  beats  it  with  a  mallet  or  hammer,  in  order  to  soAen 
it,  and  render  it  flexible. 

The  head  knifCj  called  in  French  couteau  cl  revers,  on  account  of  the  form  of  its  edge, 
which  is  much  turned  over,  is  a  tool  5  or  6  inches  broad,  and  15  or  16  long;  with 
two  handles,  one  in  the  direction  of  the  blade,  and  the  other  perpendicular  to  it,  for  the 

purpose  o(  guiding  the 
edge  more  truly  upon 
the  skin.  The  pommel 
(paumelle)  is  so  called 
because  it  clothes  the 
palm  of  the  hand,  and 
performs  its  functions. 
It  is  made  of  hard  wood, 
and  is  of  a  rectangular 
shape,  1  foot  long,  5 
inches  broad,  flat  above 
and  rounded  below.  It  is 
furrowed  over  the  round- 
ed surface  with  transverse 
parallel  straight  grooves. 
These  grooves  are  in 
section  sharp-edged  isos- 
celes triangles.  Fig3, 
441  and  442,  repre- 
sent the  pommel  in  an 
The  flat  surface  is  provided  with  a  leather  strap  lor  secur- 
Pommels  are  made  of  different  sizes,  and 


uppt:/  and  under  view. 

ing  «t  to   the  hand   of  the  workman. 

witL  grooves  of  various  degrees  of  fineness.      Cork  pommels  are  also  used,  but  they 

are  rot  grooved.     Pommels  serve  to  give  grain  and  pliancy  to  the  skins. 

The  stretching  iran,  Jig.  443,  is  a  flat  plate  of  iron  or  copper,  fully  a  fourth  of  an 
inch  t»»ick  at  top,  and  thinning  off  at  bottom  in  a  blunt  edge,  shaped  like  the  arc  of  a 
circle  of  large  diameter,  having  the  angles  a  and  6  rounded,  lest  in  working  they  should 
penetrate  the  leather.  The  top  cis  mounted  with  leather  to  prevent  it  from  hurting  the 
hands.  A  copper  stretching  knife  is  used  for  delicate  skins.  The  workman  holds  this 
tool  nearly  perpendicular,  and  scrapes  the  thick  places  powerfully  with  his  two  hands, 
esnecially  those  where  some  tan  or  flesh  remains.     He  thus  equalizes  the  thickness  of 


CURRYING  OF  LEATHER. 


557 


the  skin,  and  renders  it  at  the  same  time  more  dense  and  uniform  in  texture.    This 
tool  is  of  very  general  use  in  currying. 

The  round  knife,  Jigs.  444  and  445  {lunette  in  French),  is  a  circular  knife  from  10  to 
12  inches  in  diameter,  with  a  round  4  or  5  inch  hole  in  its  centre,  for  introducing  the 
hands  and  working  it  It  is  concave,  as  shown  in  the  section  Jig.  446,  presenting  the 
form  of  a  spherical  zone.  The  concave  part  is  that  applied  to  he  ^km.  Its  edge  is  not 
perfectly  straight;  but  is  a  little  turned  over  on  the  side  opposite  to  the  skin,  to  preven* 


446 


so 


444  ^^ "^^  1^  445  *'  from  entering  too  far  into  the  lea- 

ther. The  urrier  first  rlopes  off  with 
the  head  kn\fe  from  the  edges,  a  por- 
tion equal  to  what  he  afterwards  re- 
moves with  the  round  onr.  By  this 
division  the  work  is  done  sooner  and 
more  exactly.  All  r\e  rUeo  )r  greased 
skins  are  dressed  with  the  roand  knife. 
The  cleaner  is  a  straight  two-han- 
dled knife  two  inches  broad,  of  which 
there  are  two  kinds,  a  sharp-edged  and  a  blunt  one.    Fig.  446. 

The  mace  is  made  of  wood,  having  a  handle  30  inches  long,  with  a  cubical  head  or 
mallet ;  upon  the  two  faces  of  which,  parallel  to  the  line  of  the  handle,  there  are  4  pegs 
of  hard  wood  turned  of  an  egg-shape,  and  well  polished,  so  as  not  to  tear  the  moistened 
leather  when  it  is  strongly  beat  and  softened  with  the  mace. 

The  horse  or  trestle.  Jig.  447,  consists  of  a  strong  wooden  frame,  A  b  c  d,  which  serves  as 
a  leg  or  foot.  Upon  the  middle  of  this  frame  there  are  two  uprights,  e  f,  and  a  strong 
cross  beam,  g,  for  supporting  the  thick  plank  h,  upon  which  the  skins  are  worked.  This 
plank  may  be  set  at  a  greater  or  less  slope,  according  as  its  lower  end  is  engaged  in  one 
or  other  of  the  cross  bars,  1 1 1 1,  of  the  frame.  In  the  figure,  a  skin  £  is  represented  upon 
the  plank  with  the  head  knife  upon  it,  in  the  act  of  being  pared. 

A  cylindrical  bar  fixed  horizontally  at  its  ends  to  two  buttresses  projecting  from  the 
wall,  serves  by  means  of  a  parallel  stretched  cord,  to  fix  a  skin  by  a  coil  or  two  in  order 
to  dress  it.  This  is  accordingly  called  the  dresser.  The  tallow  cloth  is  merely  a  mop 
made  of  stout  rags,  without  the  long  handle  ;  of  which  there  are  several,  one  for  wax, 
another  for  oil,  &.c.  Strong-toothed  pincers  with  hook-end  handles,  drawn  together 
by  an  endless  cord,  are  employed  to  stretch  the  leather  in  any  direction,  while  it  is  being 
dressed.  The  currier  uses  clamps  like  the  letter  U,  lo  fix  the  edges  of  the  leather  to  his 
table.  His  polisher  is  around  piece  of  hard  wood,  slightly  convex  below,  with  a  handle 
standing  upright  in  its  upper  surface,  for  seizing  it  firmly.  He  first  rubs  with  sour  beer, 
and  finishes  with  barberry  juice. 

Every  kind  of  tanned  leather  not  intended  for  soles  or  such  coarse  purposes,  is 
generally  curried  before  being  delivered  to  the  workmen  .who  fashion  it,  such  as  shoe- 
makers, coachmakers,  saddlers,  &c.    The  chief  operations  of  the  currier  are  four  : — 

1.  Dipping  the  leather,  which  consists  in  moistening  it  with  water,  and  beating  it 
with  the  mace  or  a  mallet  upon  the  hurdle.  He  next  applies  the  cleanersy  both  blunt 
and  sharp,  as  well  as  the  head  knife,  to  remove  or  thin  down  all  inequalities.  After  the 
leather  is  shaved,  it  is  thrown  once  more  into  water,  and  well  scoured  by  rubbing  the 
grain  side  with  pumice  stone,  or  a  piece  of  slaty  grit,  whereby  it  parts  with  the  bloom,  a 
whitish  matter,  derived  from  the  oak  bark  in  the  tan  pit. 

2.  Applying  the  pommel  to  give  the  leather  a  granular  appearance,  and  correspondent 
flexibility.  The  leather  is  first  folded  with  its  grain  side  in  contact,  and  rubbed  strongly 
with  the  pommel,  then  rubbed  simply  upon  its  grain  side  ;  whereby  it  becomes  extremely 
flexible. 

3.  Scraping  the  leather.  This  makes  it  of  uniform  thickness.  The  workman  holds 
the  tool  nearly  perpendicular  upon  the  leather,  and  forcibly  scrapes  the  thick  places  with 
both  his  hands. 

4.  Dressing  it  by  the  round  knife.  For  this  purpose  he  stretches  the  leather  upon 
the  wooden  cylinder,  lays  hold  of  the  pendent  under  edge  with  the  pincers  attached  to 
his  girdle,  and  then  with  both  hands  applies  the  edge  of  the  knife  to  the  surface  of  the 
leather,  slantingly  from  above  downwards,  and  thus  pares  off  the  coarser  fleshy  parts  of 
the  skin.  This  operation  requires  great  experience  and  dexterity;  and  when  well  per- 
formed  improves  greatly  the  look  of  the  leather. 

The  hide  or  skin,  being  rendered  flexible  and  uniform,  is  conveyed  to  the  shed  or  drying 
house,  where  the  greasy  substances  are  applied,  which  is  called  dubbing  (daubing)  or 
stufl^ng.  The  oil  used  for  this  purpose  is  prepared  by  boiling  sheep-skins  or  doe-skins, 
in  cod  oil.  This  application  of  grease  is  often  made  before  the  graining  board  or  pommel 
is  employed. 

Before  waxing,  the  leather  is  commonly  colored  by  rubbing  it  with  a  brush  dipped 
into  a  composition  of  oil  and  lamo  black  on  the  flesh  side,  till  it  be  thoroughly  black ;  it  is 


558 


CUTLERY. 


then  black-sized  -with  a  bnish  or  sponge,  dried,  tallowed  with  the  proper  cloth,  and 
slicked  upon  the  flesh  with  a  broad,  smooth  lump  of  glass;  sized  again  with  a  sponge* 
and  when  dry,  again  curried  as  above  described. 

Currying  leather  on  the  hair  or  grain  side,  termed  black  on  the  grain,  is  the  same  in 
the  first  operation  with  that  dressed  on  the  flesh,  till  it  is  scoured.  Then  the  first  black 
is  applied  to  it  while  wet,  by  a  solution  of  copperas  put  upon  the  grain,  after  this  has 
been  rubb^'d  with  a  stone ;  a  brush  dipped  in  stale  urine  is  next  rubbed  on,  then  an  iron 
slicker  is  ased  to  make  the  grain  come  out  as  fine  as  possible.  It  is  now  slufled  with 
oil.  When  dr>',  it  is  seasoned ;  that  is,  rubbed  over  with  a  brush  dipped  in  copperas 
water,  on  the  grain,  till  it  be  perfectly  black.  It  is  next  slicked  with  a  good  grit-stone, 
to  take  out  the  wrinkles,  and  smooth  the  coarse  grain.  The  grain  is  finally  raised  with 
the  pommel  or  graining  board,  by  applying  it  to  the  leather  in  diflerent  directions. 
When  thoroughly  dry,  it  is  grained  again  in  two  or  three  ways. 

Hides  intended  for  covering  coaches  are  shaved  nearly  as  thin  as  shoe  hides,  and 
blacked  upon  the  grain. 

CUTLERY.  (Coutelkrie,  Fr. ;  Messerschmidwaare,  Germ.)  Three  kinds  of  steel 
are  made  use  of  in  the  manufacture  of  different  articles  of  cutlery,  viz.,  common  steel, 
shear  steel,  and  cast  steel.  Shear  steel  is  exceedingly  plastic  and  tough.  All  the  edge 
tools  which  require  great  tenacity  without  great  hardness  are  made  of  it,  such  as  table 
knives,  scythes,  plane-irons,  &c. 

Cast  steel  is  formed  by  melting  blistered  steel  in  coveitx:  crucibles,  with  bott*  glass, 
and  pouring  it  into  cast-iron  moulds,  so  as  to  form  it  into  ingots ;  these  ingots  are  then 
token  to  the  tilt,  and  drawn  into  rods  of  suitable  dimensions.  No  other  than  cast  steel 
<an  assume  a  very  fine  polish,  and  hence  all  the  finer  articles  of  cutlery  are  made  of  it, 
such  as  the  best  scissors,  penknives,  razors,  &c. 

Formerly  cast  steel  could  be  worked  only  at  a  very  low  heat ;  it  can  now  be  made  so 
as  to  be  welded  to  iron  with  the  greatest  ease.  Its  use  is  consequently  extended  to 
making  very  superior  kinds  of  chisels,  plane-irons,  &c. 

Forging  of  table  knives.  —  Two  men  are  generally  employed  in  the  forging  of  table 
knives ;  one  called  the  foreman  or  maker,  and  the  other  the  striker. 

The  steel  called  common  steel  is  employed  in  making  the  very  common  articles;  but 
for  the  greatest  part  of  table  knives  which  require  a  surface  free  from  flaws,  shear  steel 
is  generally  preferred.  That  part  of  the  knife  termed  the  blade,  is  first  rudely  formed 
and  cut  off".  It  is  next  welded  to  a  rod  of  iron  about  |  inch  square,  in  such  a  manner 
as  to  leave  as  little  of  the  iron  part  of  the  blade  exposed  as  possible.  A  sufficient  quantity 
of  the  iron  now  attached  to  the  blade,  is  taken  off  from  the  rod  to  form  the  bolster  or 
shoulder,  and  the  tang. 

In  order  to  make  the  bolster  of  a  given  size,  and  to  give  it  at  the  same  time  shape 
and  neatness,  it  is  introduced  into  a  die,  and  a  swage  placed  upon  it ;  the  swage  has  a 
few  smart  blows  given  it  by  the  striker.  This  die  and  swage  are,  by  the  workman, 
called  prints. 

After  the  tangs  and  bolster  are  finished,  the  blade  is  heated  a  second  time,  and  the 
foreman  gives  it  its  proper  anvil  finish  ;  this  operation  is  termed  smithing.  The  blade 
is  now  heated  red-hot,  and  plunged  perpendicularly  into  cold  water.  By  this  means  it 
becomes  hardened.  It  requires  to  be  tempered  regularly  down  to  a  blue  color :  in  which 
state  it  is  ready  for  the  grinder. 

Mr.  Brownill's  method  of  securing  the  handles  upon  table-knives  and  forks,  is,  by 
lengthening  the  tangs,  so  as  to  pass  them  completely  through  the  handle,  the  ends  of 
which  are  to  be  tinned  after  the  ordinary  mode  of  tinning  iron;  and,  when  passed 
through  the  handle,  the  end  of  the  tang  is  to  be  spread  by  beating,  or  a  small  hole 
drilled  through  it,  and  a  pin  passed  to  hold  it  upon  the  handle.  After  this,  caps  of 
metal,  either  copper  plated  or  silver,  are  to  be  soldered  on  to  the  projecting  end  of  the 
tang,  and  while  the  solder  is  in  a  fluid  state,  the  cap  is  to  be  pressed  upon  the  end  of 
the  handle  and  held  there  until  the  solder  is  fixed,  when  the  whole  is  to  be  cooled  by 
being  immersed  in  cold  water. 

Mr.  Thomason's  patent  improvements  consist  in  the  adaptation  of  steel  edges  to  the 
blades  of  gold  and  silver  knives.  These  steel  edges  are  to  be  attached  to  the  other 
metal,  of  whatever  quality  it  may  be,  of  which  the  knife,  &c.  is  made,  by  means  of 
•  solder,  in  the  ordinary  mode  of  effecting  that  process.  After  the  edge  of  steel  is  thus 
attached  to  the  gold,  silver,  &c.,  it  is  to  be  ground,  polished,  and  tempered  by  immersion 
in  cold  water  or  oil  after  being  heated.  This  process  being  finished,  the  other  parts  of 
the  knife  are  then  wrought  and  ornamented  by  the  engraver  or  chaser,  as  usual. 

A  patent  was  obtained  in  1827,  by  Mr.  Smith  of  Sheffield,  for  rolling  out  knives  at  one 
operation. 

.     In  the  ordinary  mode  of  making  knives,  a  sheet  of  steel  being  provided,  the  blades  are 
cut  out  of  the  sheet,  and  the  backs,  shoulders,  and  tangs,  of  wrought  iron,  are  attached  to 


CUTLERY. 


559 


the  steel  blades,  by  welding  at  the  forge.    The  knife  is  then  ground  to  the  proper  shape, 
and  the  blade  polished  and  hardened. 

Instead  of  this  welding  process,  the  patentee  proposes  to  make  the  knives  entirely  of 
steel,  and  to  form  them  by  rolling  in  a  heated  state  between  massive  rollers ;  the  shoul- 
ders or  bolsters,  and  the  tangs  for  the  handles  being  produced  by  suitable  recesses  in 
the  peripheries  of  the  rollers ;  just  as  railway  rails  are  formed.  When  the  knife  is  to 
be  made  with  what  is  called  a  scale  tang,  that  is,  a  broad  flat  tang,  to  which  the  handle 
is  to  be  attached  in  two  pieces,  riveted  on  the  sides  of  the  tang,  the  rollers  are  then  only 
to  have  recesses  cut  in  them,  in  a  direction  parallel  to  the  axis  for  forming  the  bolster. 

The  plate  of  steel,  having  been  heated,  is  to  be  pressed  between  the  two  rollers,  by 
which  the  blades  and  the  parts  for  the  scale  tangs  will  be  pressed  out  flat  and  thin,  and 
those  parts  which  pass  between  the  grooves  or  recess  will  be  left  thick  or  protuberant, 
forming  the  bolster  for  the  shoulder  of  the  blade.  But  if  the  tangs  are  to  be  round  in 
order  to  be  fixed  into  single  handles,  then  it  will  be  necessary  also  to  form  transverse 
grooves  in  the  rollers,  that  is,  at  right  angles  to  those  which  give  shape  to  the  bolsters, 
the  transverse  grooves  corresponding  in  length  to  the  length  of  the  intended  tang. 
When  the  plates  of  steel  have  been  thus  rolled,  forming  three  or  more  knives  in  a 
breadth,  the  several  knives  are  to  be  cut  out  by  the  ordinary  mode  of  what  is  called  slit- 
ting, and  the  blades  and  shoulders  ground,  hardened,  and  polished  in  the  usual  way. 

Forks  are  generally  a  distinct  branch  of  manufacture  from  that  of  knives,  and  are 
purchased  of  the  fork  makers  by  tLe  manufacturers  of  table  knives,  in  a  state  fit  for  re- 
ceiving the  handles. 

The  rods  of  steel  from  which  the  forks  arc  made,  are  about  |ths  of  an  inch  square. 
The  tang  and  shank  of  the  fork  are  first  roughly  formed.  The  fork  is  then  cut  off, 
leaving  at  one  end  about  1  inch  of  the  square  part  of  the  steel.  This  part  is  afterwards 
drawn  out  flat  to  about  the  length  of  the  prongs.  The  shank  and  tang  are  now 
heated,  and  a  proper  form  given  to  them  by  means  of  a  die  and  swage.  The  prongs  are 
afterwards  formed  at  one  blow  by  means  of  the  stamp ;  this  machine  is  very  similar  to 
that  used  in  driving  piles,  but  it  is  worked  by  one  man.  It  consists  of  a  large  anvil 
fixed  in  a  block  of  stone  nearly  on  a  level  with  the  ground.  To  this  anvil  are  attached 
two  rods  of  iron  of  considerable  thickness,  fixed  twelve  inches  asunder,  perpendicularly  to 
the  anvil,  and  diagonally  to  each  other.  These  are  fastened  to  the  ceiling.  The  ham- 
mer or  stamp,  about  100  lbs.  in  weight,  having  a  groove  upon  either  side  corresponding  to 
the  angles  of  the  upright  rods,  is  made  to  slide  freely  through  its  limited  range,  being 
conducted  by  its  two  iron  supporters.  A  rope  is  attached  to  the  hammer,  which  goes 
over  a  pulley  on  the  floor  of  the  room  above,  and  comes  down  to  the  person  who  works 
the  stamp :  two  corresponding  dies  are  attached,  one  to  the  Kammer,  and  the  other  to 
the  anvil.  That  part  of  the  fork  intended  to  form  the  prongs,  is  heated  to  a  pretty  white 
heat  and  placed  in  the  lower  die,  and  the  hammer  containing  the  other  die  is  made  to 
fall  upon  it  from  a  height  of  about  7  or  8  feet.  This  forms  the  prongs  and  the  middle 
part  of  the  fork,  leaving  a  very  thin  substance  of  steel  between  each  prong,  which  is 
afterwards  cut  out  with  an  appropriate  instrument  called  a  fly-press.  The  forks  are  now 
annealed  by  surrounding  a  large  mass  of  them  with  hot  coals,  so  that  the  whole  shall 
become  red-hot.  The  fire  is  suffered  gradually  to  die  out,  and  the  forks  to  cool  without 
beins  disturbed.  This  process  is  intended  to  soften,  and  by  that  means  to  prepare  them 
for  filing.  The  inside  of  the  prongs  is  then  filed,  after  which  they  are  bent  into  their 
proper  form  and  hardened.  When  hardened,  which  is  effected  by  heating  them  red-hot 
and  plunging  them  into  cold  water,  they  are  tempered  by  exposing  them  to  the  degree  of 
heal  at  which  grease  inflames.     See  Stamps. 

Penknives  are  generally  forged  by  a  single  hand,  with  the  hammer  and  the  anvil  sim 
ply.  The  hammer  in  this  trade  is  generally  light,  not  exceeding  3|  lbs.  The  breadlfi 
of  the  face,  or  the  striking  part,  is  about  one  inch;  if  broader,  it  would  not  be  conven- 
ient for  striking  so  small  an  object.  The  principal  anvil  is  about  5  inches,  and  10  upon 
the  face,  and  is  provided  with  a  groove  into  which  a  smaller  anvil  is  wedged.  The 
smaller  anvil  is  about  2  inches  square  upon  the  face.  The  blade  of  the  knife  is  first 
drawn  out  at  the  end  of  the  rod  of  steel,  and  as  much  more  is  cut  off  along  with  it  as 
is  thought  necessary  to  form  the  joint.  The  blade  is  then  taken  in  a  pair  of  tongs,  and 
heated  a  second  time  to  finish  the  joint  part,  and  at  the  same  time  to  form  a  temporary 
tang  for  the  purpose  of  driving  into  a  small  haft  used  by  the  grinder.  Another  heat  is 
taken  to  give  the  blade  a  proper  finish.  The  small  recess  called  the  nail-hole,  used  in 
opening  the  knife,  is  made  while  it  is  still  hot  by  means  of  a  chisel,  whicn  is  round  on 
one  side,  and  flat  upon  the  other.  * 

Penknives  are  hardened  by  heating  the  blade  red-hot,  and  dipping  them  into  water  up 
to  the  shoulder.  They  are  tempered  by  setting  them  side  by  side,  with  the  back  down- 
wards upon  a  flat  iron  plate  laid  upon  the  fire,  where  they  are  allowed  to  remain  till  thej 
are  of  a  brown  or  purple  color. 

36 


560 


CUTLEKy 


The  blades  of  pocket  knives,  and  aU  that  come  under  the  denomination  of  Bvnne 

knives,  are  made  m  the  same  way.  ^     ° 

The  forging  of  razors  is  performed  by  a  foreman  and  striker,  as  in  making  table 

Thev  are  generally  made  of  cast  steel.  The  rods,  as  they  come  from  the  tilt,  are 
about  t  inch  broad,  and  of  a  thickness  sufficient  for  the  back  of  a  razor 

There  is  nothing  peculiar  in  the  tools  made  use  of  in  forging  razors :'  the  anvil  is  a 
.ittle  rounded  at  the  sides,  which  affords  the  opportunity  of  making  the  eclsre  thinner  and 
laves  an  immense  labor  to  the  grinder.  "  >    "«• 

Razors  are  hardened  and  tempered  in  a  similar  manner  to  penknives.    They  are 
however,  left  harder,  being  only  let  down  to  yelJow  or  brown  color  * 

The  for-ing  of  scissors  is  wholly  performed  by  the  hammer,  and  all  the  sizes  are  made 
by  a  single  hand.  The  anvil  of  the  scissor-maker  weighs  about  U  cwt.;  it  measures, 
on  the  face,  about  4  by  II  inches.  It  is  provided  with  two  grates  o?  grooves  for  the  r^ 
ception  of  various  little  indented  tools  termed  by  the  workman  bosses;  one  of  these 
bosses  IS  employed  to  give  proper  figure  to  the  shank  of  tl^*  scissors ;  another  for  form- 
ing that  part  which  has  to  make  the  joint ;  and  a  third  is  n4lle  use  of  for  giving  a  proper 
figure  to  the  upper  side  of  the  blade.  There  is  also  another  anvil  placed  on  the  same 
block  containing  two  or  three  tools  called  beak-irons,  each  consisting  of  an  upright  stem 
about  6  mcht^s  high,  at  the  top  of  which  a  horizontal  beak  projects ;  one  of  these  beaks 
IS  conical,  and  is  used  for  extending  the  bow  of  the  scissors ;  the  other  is  a  segment  of  a 
cylinder  with  the  round  side  upwards,  containing  a  recess  for  giving  a  proper  shape  and 
smoothness  to  the  mside  of  the  bow.  s      f    h     »     pc  «uu 

The  shank  of  the  scissors  is  first  formed  by  means  of  one  of  the  bosses,  above  de- 
scribed, leaving  as  much  steel  at  the  end  as  will  form  the  blade.  A  hole  is  then  punched 
about  J  inch  m  width,  a  little  above  the  shank.  The  blade  is  draT^n  out  and  finished 
and  the  scissors  separated  from  the  rod  a  little  above  the  hole.  It  is  heated  a  third  time! 
and  the  small  hole  above  mentioned  is  extended  upon  the  beak-irons  so  as  to  form  the 
bow.  This  finishes  the  forging  of  scissors.  They  are  promiscuously  made  in  this  way. 
without  any  other  guide  than  the  eye,  having  no  regard  to  their  being  in  pairs.  They 
are  next  annealed  for  the  purpose  of  filing  such  parts  of  them  as  cannot  be  ground,  and 
afterwards  paired.  ' 

The  very  large  scissors  are  made  partly  of  iron,  the  blades  being  of  steel. 
ci^^^^^'^J^^  forging,  the  bow  and  joints,  and  such  shanks  as  cannot  be  ground,  are 
filed.  The  rivet  hole  is  then  bored,  through  which  they  are  to  be  screwed  or  riveted 
together.  This  common  kind  of  scissors  is  only  hardened  up  to  the  joint  They 
are  tempered  down  to  a  purple  or  blue  color.  In  this  state  they  are  taken  to  the 
grinder. 

Grinding  and  polishing  of  cutlery.— The  various  processes  which  come  under  this 
denomination  are  performed  by  machinery,  moving  in  general  by  the  power  of  the  steam- 
engine  or  water-wheel. 

Grinding  wheels  or  grinding  mills  are  divided  into  a  number  of  separate  rooms  •  every 
room  contains  six  places  called  troughs  ;  each  trough  consists  of  a  convenience  for  run- 
ning a  grindstone  and  a  polisher  at  the  same  time,  which  is  generally  occupied  by  a  man 

The  business  of  the  grinder  is  generally  divided  into  three  stages,  viz.,  erindine. 
glazing,  and  polishing.  '  ^  ^' 

The  grinding  is  performed  upon  stones  of  various  qualities  and  sizes,  depending  on  the 
articles  to  be  ground.  Those  exposing  much  flat  surface,  such  as  saws,  fenders,  &c., 
require  stones  of  great  diameter,  while  razors,  whose  surface  is  concave,  require  to  be 
ground  upon  stones  of  very  small  dimensions.  Those  articles  which  require  a  certain 
temper,  which  is  the  case  with  most  cutting  instruments,  are  mostly  ground  on  a  wet 
stone;  [or  which  purpose  the  stone  hangs  within  the  iron  trough,  filled  with  water  to 
such  a  height  that  its  surface  may  just  touch  the  face  of  the  stone. 

Glazing  IS  a  process  following  that  of  grinding:  it  consists  in  giving  that  degree  of 
lustre  and  smoothness  to  an  article  which  can  be  eflfected  by  means  of  emery  of  the 
various  degrees  of  fineness.  The  tool  on  which  the  glazing  is  performed,  is  termed  a 
glazer.  It  consists  of  a  circular  piece  of  wood,  formed  of  a  number  of  pieces  in  such  a 
manner  that  its  edge  or  face  may  always  present  the  endway  of  the  wood.  Were  it 
made  otherwise,  the  contraction  of  the  parts  would  destroy  its  circular  figure.  It  is 
fixed  upon  an  iron  axis  similar  to  that  of  the  stone.  Some  glazers  are  covered  on  the 
face  with  leather,  others  with  metal,  consisting  of  an  alloy  of  lead  and  Un ;  the  latter 
are  termed  caps.  In  others,  the  wooden  surface  above  is  made  use  of.  Some  of  the 
leather-faced  glazers,  such  as  are  used  for  forks,  table  knives,  edge  tools,  and  all  the 
coarser  polished  articles,  are  first  coated  with  a  solution  of  glue,  and  then  covered  with 
emery.    The  surfaces  of  the  others  are  prepared  for  use  by  first  turning  the  face  verf 


CIDER. 


561 


true,  then  filling  it  with  small  notches  by  means  of  a  sharp-ended  hammer,  and  lastly 
filling  up  the  interstices  with  a  compound  of  tallow  and  emery. 

The  pulley  of  the  glazer  is  so  much  less  than  that  of  the  stone,  that  its  velocity  is 
more  than  double,  haying  in  general  a  surface-speed  of  1,600  feet  in  a  second. 

The  process  of  polishing  consists  in  giving  the  most  perfect  polish  to  the  different 
articles.  Nothing  is  subjected  to  this  operation  but  what  is  made  of  cast  steel,  and  has 
been  previously  hardened  and  tempered. 

The  polisher  consists  of  a  circular  piece  of  wood  covered  with  buff  leather,  the  sur- 
face of  which  is  covered  from  time  to  time,  while  in  use,  with  the  crocus  of  iron,  called 
also  colcothar  of  vitriol. 

The  polisher  requires  to  run  at  a  speed  much  short  of  that  of  the  stone,  or  the  glazer. 
Whatever  may  be  its  diameter,  the  surface  must  not  move  at  a  rate  exceeding  70  or  80 
feet  in  a  second. 

CYANATES;  saline  compounds  of  cyanic  acid  with  the  bases  potash,  soda,  ammo- 
ma,  baryta,  <fec.  The  first  is  prepared  by  calcining  at  a  dull  red  heat,  a  mixture  of 
ferro-cyanide  of  potassium  (prussiate  of  potash)  and  black  oxide  of  manganese.  The 
cyanates  have  not  hitherto  been  applied  to  any  use  in  the  arts. 

CYANHYDRIC  ACID;  another  name  for  the  hydrocyanic  or  prussic  acid.  See 
Prussian  Blue  and  Prussic  Aao. 

CYANIDES ;  compounds  of  cyanogen  with  the  metals ;  as  cyanide  of  potassium 
sodium,  bnrium,  calcium,  iron,  mercury.     The  last  is  the  only  one  of  importance  in  a 
manufacturing  point  of  view,  since  from  it  prussic  acid  is  often  made. 

CYANIDES,  FERRO.  Double  compounds  of  cyanogen  with  iron,  and  of  cyanogen 
with  another  metal,  such  as  potassium,  sodium,  barium,  <fee.  The  ordinary  yellow  prus- 
siate of  potash  has  this  constitution,  and  is  called  the  ferro-cyanide 

CYANIDE  OF  POTASSIUM.  This  salt,  so  much  used  now  in  the  electrotype  pro- 
cesses, IS  prepared,  according  to  Liebig's  formula,  by  mixing  8  parts  of  pounded  prussiate 
of  potasli,  sharply  dried,  with  3  parts  of  pure  carbonate  of  potash,  fusing  the  mixture 
m  an  iron  crucible,  by  a  moderate  red  heat,  and  keeping  it  so,  till  the  glass  or  iron  rod 
wiUi  which  the  fluid  mass  should  be  occasionally  stirred,  comes  out  covered  with  a 
white  crust.  The  crucible  is  then  to  be  removed  from  the  fire;  and  after  the  disen- 
gaged iron  has  fallen  to  the  bottom,  the  supernatant  fluid,  still  obscurely  red  hot,  is  to 
be  poured  off  upon  a  clean  surface  of  iron  or  platinum.  After  concretion  and  cooling 
the  white  saline  mass  is  to  be  pounded  while  hot,  and  then  kept  in  a  well-stopped  bot- 
tle. It  consists  of  about  only  60  per  cent  of  cyanide  of  potassium,  and  1  of  cyanate  of 
potash.  For  most  purposes,  and  the  analysis  of  ores,  the  latter  ingredient  is  no  ways 
detrimental.     It  contains  much  of  other  potash  salts. 

CYANOGEN.  A  gaseous  compound  of  two  prime  equivalents  of  charcoal  =  12,  and 
one  of  azote  =  14  =  26;  hydrogen  being  the  radix,  or  I.  It  consists  of  two  volumes 
ol  vapor  of  carbon,  and  one  volume  of  azote,  condensed  into  one  volume;  and  has  there- 
fore  a  density  equal  to  the  sum  of  the  weights  of  these  three  gaseous  volumes  =  1-815 
Cyanogen  is  readily  procured  by  exposing  the  cyanide  of  mercury  to  a  dull  red  heat  iii 
a  retort ;  the  gas  is  evolved  and  may  be  collected  over  mercury.  Its  smell  is  very  sham 
and  penetrating ;  it  perceptibly  reddens  tincture  of  litmus;  it  is  condensable  by  pre-^sure 
at  a  low  temperature  into  a  liquid  ;  and  by  a  still  greater  degree  of  cold,  it  is  solidified 
When  a  lighted  taper  is  applied  to  a  mixture  of  cyanogen  and  oxygen,  an  explosion  takes 
place ;  carbonic  acid  is  formed,  and  the  azote  is  set  at  liberty. 

For  a  connected  view  of  the  various  compounds  of  cyanogen  employed  in  the  arts  see 
Prussian  Blue.  j    y-^ 

CIDER  (Cidrc,  Fr.;  Jpfelv-ein,  Germ.);  the  vinous  fermented  juice  of  the  annle 
The  ancients  were  acquainted  with  cider  and  perry,  as  we  learn  from  the  following  pas^ 
sage  of  Piny  the  naturalist :  «  Wine  is  made  from  the  Syrian  pod,  from  pears  and  Ipples 
of  every  kind."  Book  xiv.  chap.  19.  The  term  cider  or  cidre  in  French,  at  first  written 
ndre,  is  derived  from  the  Latin  word  sicera,  which  denoted  all  other  fermented  liquors 
except  grape  wine.  Cider  seems  to  have  been  brought  into  Normandy  by  the  Moors  of 
Biscay,  who  had  preserved  the  use  of  it  after  coming  into  that  country  from  Africa  It 
was  afterwards  spread  through  some  other  provinces  of  France,  whence  it  was  intro- 
duced into  England  Germany,  and  Russia.  It  is  supposed  that  the  first  growths  of  Nor- 
mandy afiord  still  the  best  specimens  of  cider.  Devonshire  and  Herefordshire  are  the 
counties  of  England  most  famous  for  this  beveraffe. 

Strong  and  somewhat  elevated  ground,  rather  dry,  and  not  exposed  to  the  air  of  the 
sea,  or  to  high  winds,  are  the  best  situations  for  the  growth  of  the  cider  apple.  The 
fruit  should  be  gathered  m  dry  weather.  The  juice  of  apples  is  composed  of  a  great 
deal  of  water;  a  little  sugar  analogous  to  that  of  the  grape;  a  matter  capable  of  causing 
fermentation  with  contact  of  air;  a  pretty  large  proportion  of  mucilage,  with  malic  acid 
acetic  acid,  and  an  azolized  matter  in  a  very  small  quantity.  The  seeds  contain  a  bitter 
substance  and  a  little  essential  oil ;  the  pure  parenchyma  or  cellular  membrane  con«»titute» 


662 


CIDER. 


not  more  than  two  per  cent  of  the  whole.     After  the  apples  are  gathered  they  are  left 
in  the  barn-loft  for  fifteen  days  or  upwards  to  mellow ;  some  of  them  in  this  case  how 
ever  become  soft  and  brown.     This  degree  of  maturation  diminishes  their  muiilaffe 
and  develops  alcohol  and  carbonic  acid;  in  consequence  of  which  the  cider  suffers  no 
injury.     There  is  always,  however,  a  little  loss;  and  if  this  ripening  goes  a  little  further 
It  IS  very  apt  to  do  harm,  notwithstanding  the  vulgar  prejudice  of  the  country  peonle 
to  the  contrary     Too  much  care,  indeed,  cannot  be  taken  to  separate  the  sound  from 
the  spoiled  apples;  for  the  latter  merely  furnish  an  acid  leaven,  give  a  disagreeable 
taste  to  the  juice,  and  hinder  the  cider  from  fining,  by  leaving  in  it  a  certain  portion 
of  the  pnrenchyma,  which  the  gelatinous  matter  or  the  fermentation  has  diffused  throuffh 
It     Unnpe  apples  should  be  separated  from  the  ripe  also,  for  they  possess  too  little 
saccharum  to  be  properly  susceptible  of  the  vinous  fermentation. 

In  France,  where  cider-making  is  most  scientifically  practised,  it  is  prepared  by 
crushing  the  apples  in  a  mill  with  revolving  edge-stones,  turned  in  a  circular  stone  cis- 
tern by  one  or  two  horses.  When  the  fruit  is  half  mashed,  about  one  fifth  of  its  weight 
of  river  water  18  added,  or  the  water  of  lakes.  The  latter  has  been  found  by  experi- 
ence to  be  preferable  to  other  water.  j  ^  i  tru 

In  some  places  a  mill  composed  of  two  cast-iron  fluted  cylinders,  placed  parallel  to 
each  other  under  the  bottom  of  a  hopper,  is  employed  for  crushing  the  apples.  One  of 
the  cylinders  is  turned  by  a  winch,  and  communicates  its  motion  in  the  opposite  direc- 
rion  by  means  of  the  flutings  working  into  each  other.  Each  portion  of  the  fruit  must 
be  passed  thrice  through  this  rude  mill  in  order  to  be  sufficiently  mashed ;  and  the  same 
quantity  of  Avater  must  be  added  as  in  the  edge  stone  mill. 

Af\er  the  apples  are  crushed  they  are  usually  put  into  a  large  tub  or  tun  for  12  or  24 
Mours.  This  steeping  aids  the  separation  of  the  juice,  because  the  fermentative  motion 
which  tak3s  place  m  the  majs  breaks  down  the  cellular  membranes;  but  there  is  always 
a  loss  of  alcohol  carried  oft^  by  the  carbonic  acid  disengaged,  while  the  skins  and  seeds 
develop  a  disagreeable  taste  in  the  liquid.  The  vatting  might  be  suppressed  if  the  apples 
were  so  comminuted  as  to  give  out  their  juice  more  readily.  With  slight  modifications, 
the  process  employed  in  rasping  and  squeezing  the  beet-roots  might" in  my  opinion  be 
applied  with  great  advantage  to  the  cider  manufacture.     See  Sugar. 

After  the  vatting,  the  mashed  fruit  is  carried  to  the  press  and  put  upon  a  square  wicker 
frame  or  into  a  hair  bag,  sometimes  between  layers  of  straw,  and  exposed  stratum  super 
stratum  to  strong  pressure  till  what  is  called  a  cheese  or  cake  is  formed.  The  mass 
is  to  be  allowed  to  drain  for  some  time  before  applying  pressure,  which  ouo\n  to 
be  very  gradually  increased.  The  juice  which  exudes  .vith  the  least  r-»ssure 
affords  the  best  cider ;  that  which  flows  towards  the  end  acquires  a  disagreeable  taste 
from  the  seeds  and  the  skins.  The  must  is  put  into  casks  with  large  bun'^holes  where 
It  soon  begins  to  exhibit  a  tumultuous  fermentation.  The  cask  must  be  completely 
filled,  m  order  that  all  the  light  bodies  suspended  in  the  liquid  when  floated  to  the  top 
by  the  carbonic  acid  may  flow  over  wiih  the  froth;  this  means  of  clearin*'  cider  is 
particularly  necessary  with  the  weak  kinds,  because  it  cannot  be  expected  that  these 
matters  in  suspension  will  fall  to  the  bottom  of  the  casks  after  the  motion  has  ceased 
In  almost  every  circumstance  besides,  when  no  saccharine  matter  has  been  added  to  the 
must,  that  kind  of  yeast  which  rises  to  the  top  must  be  separated,  lest  by  precipitation 
it  may  excite  an  acid  fermentation  in  the  cider.  The  casks  are  raised  upon  gawntrees 
or  stilhons,  m  order  to  place  flat  tubs  below  them  to  receive  the  liquor  which  flows  over 
with  the  froth.  At  the  end  of  two  or  three  days,  for  weak  ciders  which  are  to  be 
drunk  somewhat  sweet,  of  6  or  10  days  or  more  for  stronger  ciders,  with  variations  for 
the  state  of  the  weather,  the  fermentation  will  be  sufficiently  advanced,  and  the  cider  may 
be  racked  off  into  other  casks.  Spirit  puncheons  preserve  cider  better  than  any  other, 
but  in  all  cases  the  casks  should  be  well  seasoned  and  washed.  Sometimes  a  snlphur 
match  IS  burned  in  them  before  introducing  the  cider,  a  precaution  to  be  generally 
recommended,  as  it  suspends  the  activity  of  the  fermcntaUon,  and  prevents  the  formation 
of  vinegar. 

The  cider  procured  by  the  first  expression  is  called  cider  without  water.  The  cake 
remaining  in  the  press  is  taken  out,  divided  into  small  pieces,  and  mashed  anew,  adding 
about  half  the  weight  of  water,  when  the  whole  is  carried  back  to  the  press  and  treated 
as  above  described.  The  liquor  thus  obtained  furnishes  a  weaker  cider  which  will  not 
keep,  and  therefore  must  be  drunk  soon. 

The  cake  is  once  more  mashed  up  with  water,  and  squeezed,  when  it  yields  a  liquor 
which  may  be  used  instead  of  water  for  moistening  fresh  ground  apples. 

The  processes  above  described,  although  they  have  been  long  practised,  and  have 
therefore  the  stamp  of  ancestral  wisdom,  are  extremely  defective.  Were  the  apples  ground 
with  a  proper  rotatory  rasp  which  would  tear  all  their  cells  asunder,  and  the  mash  put 
through  the  hydraulic  press  in  bags  between  hurdles  of  wicker-work,  the  juice  would 
be  obtained  in   a  state  of  perfection  fit  to  make  a  ckler  superior  to  many  wines 


DAGUERREOTYPE. 


563 


I 


An  experimental  process  of  this  kind  has  been  actually  executed  in  France  upon  a  con- 
siderable scale,  with  the  best  results.  The  juice  had  the  fine  flavor  of  the  apple,  was 
fermented  by  itself  without  any  previous  fermentation  in  the  mash,  and  afforded  an 
excellent  strong  cider,  which  kept  well. 

When  the  must  of  the  apples  is  weak  or  sour,  good  cider  cannot  be  made  from  it 
without  the  addition  of  some  saccharine  matter.  The  syrup  into  which  potato  farina 
is  convertible  by  diastase  (saccharine  ferment),  see  Starch  and  Sugar,  would  answer 
well  for  enriching  poor  apple-juice. 

The  value  of  apples  to  produce  this  beverage  of  good  quality  is  proportionate  to  the 
specific  gravity  of  their  juice.  M.  Couverchel  has  given  the  following  table,  illustrative 
of  that  proposition : — 


Juice  of  the  green  renette,  queen  apple  {reinette  verte) 

English  renette  ... 

Red  renette  ... 

Musk  renette  ... 

Fouillet  ray&  ... 

Orange  apple  ... 

Renette  of  Caux  ... 
Water 


1094 
1080 
1072 
1069 
1064 
1063 
1060 
1000 


Cider  apples  may  be  distributed  into  three  classes — the  sweet,  the  bitter,  and  the 
sour.  The  second  are  the  best;  they  afford  a  denser  juice,  richer  in  sugar,  which  clari- 
fies well,  and  when  fermented  keeps  a  long  time ;  the  juice  of  sweet  apples  is  difficult 
to  clarify ;  but  that  of  the  sour  ones  makes  bad  cider.  Late  apples  are  in  general  to 
be  preferred.  With  regard  to  the  proper  soil  for  raising  apple-trees,  the  reader  may 
consult  with  advantage  an  able  essay  upon  "The  Cultivation  of  Orchards  and  the 
making  of  Cider  and  Perry,"  by  Frederick  Falkner,  Esq.,  in  the  fourth  volume  of  the 
Royal  Agricultural  Journal.  He  adverts  judiciously  to  the  necessity  of  the  presence 
of  alkaline  and  earthy  bases  in  the  soils  of  all  deciduous  trees,  and  especially  of  such 
as  produce  acid  fruits. 

In  November,  2340  kilogrammes  of  apples  (2|  tons  English,  nearly)  are  supposed  to 
afford  1000  litres  (220|  gallons)  of  pure  cider ;  and  600  litres  of  a  small  cider  made 
with  the  marc  mixed  with  water  and  pressed.  But  many  persons  mix  all  together,  and 
thus  manufacture  1600  litres  out  of  the  above  weight  of  fruit  In  France,  the  fermented 
liqiior,  as  soon  as  it  is  clear,  is  often  racked  off"  into  casks  containing  the  fumes  of  burn- 
ing sulphur,  whereby  it  ceases  to  ferment,  and  preserves  much  of  its  sugar  undecom- 
Cosed.  It  is  soon  afterwards  bottled.  Average  cider  should  yield  6  per  cent  of  alco- 
ol  on  distillation. 

D. 

DAGUERREOTYPE  This  new  and  most  ingenious  invention,  for  producing  pic- 
tures by  the  action  of  light  is  due  to  M.  Daguerre  and  M.  Niepce,  two  Frenchmen.  It 
was  purchased  from  them  by  the  French  government  for  the  benefit  of  the  nation  at 
large ;  but  was  made  the  subject  of  an  exclusive  patent  in  this  country  by  K  Daguerre, 
as  our  government  never  purchases  any  scientific  invention. 

The  fixation  of  the  images,  formed  in  the  focus  of  the  camera  obscura,  is  made  on 
very  smooth  surfaces  of  pure  silver  plated  on  copper.  The  process  is  divided  into  five 
operations.  1.  The  first  consists  in  polishing  and  cleaning  the  silver  surface,  by  fric- 
tion  with  cotton  fleece  imbued  with  olive  oil,  upon  the  plate,  previously  dusted  over 
with  very  finely-ground  dry  pumice-stone  out  of  a  muslin  bag.  The  hand  of  the 
operator  should  be  moved  round  in  circles,  of  various  dimensions.  The  plates  should 
be  laid  upon  a  sheet  of  paper  solidly  supported.  The  pumice  must  be  ground  to 
an  impalpable  powder  upon  a  porphyry  slab  with  water,  and  then  dried.  The  sur- 
face is  next  to  be  rubbed  with  a  dossil  of  cotton,  slightly  moistened  with  nitric  acid, 
diluted  with  sixteen  parts  of  water,  by  applying  the  tuft  to  the  mouth  of  the  phial  ol 
acid,  and  inverting  it  for  a  moment.  Two  or  three  such  dossils  should  be  used  in 
succession.  The  plate  is  lastly  to  be  sprinkled  with  pumice  powder  or  Venetian 
tripoli,  and  rubbed  clean  with  cotton. 

The  next  step  is  to  heat  the  plate  by  placing  it  in  a  wire  frame  {fig.  449),  with  the 
silver  surface  uppermost,  over  a  spirit  lamp,  meanwhile  moving  it  so  as  to  act  equally 
on  every  part  of  the  plate.  In  about  five  minutes  a  whitish  coating  will  indicate  that 
this  operation  is  completed.  The  plate  must  now  be  laid  upon  a  flat  metal  or  marble 
skb  to  cool  it  quickly.  The  white  surface  is  to  be  brightened  by  rubbing  it  with 
cotton  and  pumice  powder.  It  must  be  once  more  rubbed  with  the  cotton  imbued 
with  acid,  and  afterward  dried  by  friction  with  cotton  and  pumice ;   avoiding  to  touch 


564 


DAGUEBREOTYPE. 


the  plate  with  th3  fingers,  or  with  the  part  of  the  cotton  held  in  them,  or  to  breatbf 
upon  the  plate,  since  spots  would  thereby  be  produced.  After  cleaning  with  cotton 
alone,  the  plate  is  ready  for  the  next  operation. 

2.  Here  the  following  implements  are  required  :    1,  the  box  represented  in  Jigs.  450 
and  451 ;  2,  the  thin  lK>ard  or  frame,  Jig.  452 ;  four  small  metallic  bands  of  the  same 


& 

i«o 

h          • 

0«-j 

d 

d     d 

d 

"J. 

-m-^ml^ 

metals  as  the  plates,  also  shown  in  ^g,  452,  a  small  handle  and  a  box  of  small  nails  Of 
tacks,  and  a  phial  of  iodine. 

After  fixing,  by  the  metallic  bands  and  the  small  nails,  the  plate  upon  the  thin 
board,  with  the  silver  uppermost,  several  particles  of  iodine  are  then  to  be  spread  in 
the  dish  d,  at  the  bottom  of  the  box,^g^.  450,  and  451.  The  thin  board  with  the  plate, 
18  next  placed,  with  the  silver  beneathy  upon  small  supports  at  the  four  comers  of  the 
box,  and  its  cover  is  applied.  The  plate  must  be  left  in  this  position  till  the  surface  of 
the  silver  acquires  a  fine  golden  hue,  caused  by  the  vapors  of  the  iodine  rising  through 
the  gauze  cover  of  the  dish,  and  condensing  upon  it ;  but  it  should  not  be  allowed  to 
assume  a  violet  tint.  The  room  should  be  darkened,  and  no  heat  should  be  employed. 
When  the  box  is  in  constant  use  it  gets  impregnated  with  iodine,  and  acts  more  uni- 
formly and  rapidly ;  but  in  general  states  of  the  atmospheric  temperature  this  operation 
will  be  efiected  in  about  twenty  minutes.  If  the  purple  color  be  produced,  the  plate 
must  be  repolished,  and  the  whole  process  repeated. 

The  plate  with  its  golden  hue  is  to  be  introduced  with  its  board  into  the  frame,  Jigs, 
453, 454, 455,  which  is  adapted  to  the  camera  obscura.  During  this  transfer  the  light  must 
not  be  suffered  to  strike  upon  the  surface  of  the  plate ;  on  which  account,  the  camera 
obscura  may  be  lighted  briefly  with  a  small  wax  taper. 

3.  The  plate  is  now  submitted  to  the  third  operation,  that  of  the  camera  obscurn. 
Jigs.  456  and  448,  and  with  the  least  possible  delay.  The  action  of  this  machine  is  ob- 
viously quicker  the  brighter  the  light  which  acts  upon  it ;  and  more  correct,  according 
as  the  focus  is  previously  accurately  adjusted  to  the  place  of  the  plate,  by  moving 
backwards  and  forwards  a  roughened  pane  of  glass,  till  the  focal  point  be  found ;  and 
the  plate  is  to  be  inserted  precisely  there,  see  Jigs.  453,  454,  455.  This  apparatus  ex- 
actly replaces  the  ground  glass.  While  the  prepared  plate  is  being  fastened,  the  camera 
must  be  closed.  The  darkening  sliutters,  b  b,  of  the  apparatus  are  opened  by  means  of 
the  two  semicircles,  a  a.  The  plate  is  now  in  a  proper  position  to  receive  and  retain 
the  impression  of  the  image  of  the  objects  presented  the  moment  that  the  camera  is 
opened.  Experience  alone  can  teach  the  proper  length  of  time  for  submitting  the  plate 
to  the  concentrated  rays  of  light ;  because  that  time  varies  with  the  climate,  the  sea- 
sons, and  the  time  of  day.  More  time  should  not  be  allowed  to  pass  than  what  is 
necessary  for  fixing  a  distinct  impression,  because  the  parts  meant  to  be  clear  would 
be  apt  to  become  clouded. 

4.  The  fourth  is  the  operation  with  quicksilver,  which  must  follow  as  soon  as  pos- 
sible the  completion  of  the  third.  Here  a  phial  of  quicksilver,  a  spirit-lamp  (the 
apparatus  represented  in  Jigs.  457  and  458),  and  a  glass  funnel  with  a  long  neck,  are 
required.    Tlie  funnel  is  used  for  pouring  the  mercury  into  the  cup  c,  placed  in  the 


DAGUERREOTYPE. 


565 


bottom  of  the  apparatus,  so  as  to  cover  the  bulb  of  the  thermometer  /  ^o  daylight 
must  now  be  admitted,  but  that  of  a  small  taper  only  should  be  used  by  the  operator 
in  conducting  the  process.    The  board  with  the  plate  is  to  be  withdrawn  from  the 


J' 


camera,  and  inserted  into  the  grooves  of  the  blackened  board,  b,  Ji^.  467.  This  black 
board  is  laid  back  into  the  box  at  an  angle  of  45°  with  the  horizon ;  the  prepared 
metal  surface  h  being  placed  undermost,  so  that  it  may  be  viewed  through  the  side 
glass  (7;  and  the  cover,  a,  of  the  box  must  be  put  down  gently,  to  prevent  any  par- 
tides  of  mercury  from  being  thi-own  about  by  the  agitation  of  the  air.  The  whoU 
being  thus  prepared,  the  spirit-lamp  is  lighted,  and  j>laeed  under  the  cup  containing 
the  mercury,  and  left  there  until  the  thermometer  indicates  a  temperature  of  140*^ 
Fahr.,  when  the  lamp  is  to  be  removed.    The  heat  should  in  no  case  be  permitted  to 

exceed  167^  F.  „  ,  ,       1  .      • 

Tlie  impression  of  the  image  of  nature  is  now  actually  made  upon  the  plate ;  but  it 
is  yet  invisible ;  and  it  is  only  after  a  lapse  of  several  minutes  that  faint  tracings  of 
the  objects  begin  to  be  seen  through  the  peep-glass  by  the  momentary  gleam  of  a 
taper.  The  plate  should  be  left  in  the  box  till  the  thermometer  has  cooled  to  113°  F., 
when  it  is  to  be  taken  out  • 

After  each  operation,  the  interior  of  the  apparatus,  and  the  black  board  or  frame, 
should  be  carefully  wiped,  in  order  to  remove  every  particle  of  mercury. 

The  picture  may  now  be  inspected  in  a  feeble  light,  to  see  how  far  the  process  has 
succeeded.  The  plate,  freed  from  the  metallic  bands,  is  to  be  placed  in  a  box,  pro- 
vided with  a  cover  and  grooves,  to  exclude  the  light,  till  it  is  made  to  undergo  the  fifth 
and  last  operation,  which  may  be  done  after  any  convenient  interval  of  time  without 
detriment,  provided  the  plate  be  kept  in  the  dark.  The  following  articles  are  now 
required :  1,  strong  brine,  or  a  weak  solution  of  hyposulphate  of  soda ;  2,  the  api^- 
ratus  represented  in  Jigs.  459  and  460 ;  3,  two  troughs  of  tin-plate ;  4,  a  jug  of  dis- 
tilled water.    The  object  of  this  process  is  to  fix  the  photogenic  picture.    One  of  the 


566 


DAGUERREOTYPE. 


troughs  is  to  be  filled  with  brine  to  the  depth  of  an  inch,  and  the  other  with  pur« 
water,  both  liquids  being  heated  somewhat  under  the  boiling  pitch.  The  solirtion  of 
hyposulphite  of  soda  is  preferable,  and  does  not  need  to  be  warm.  The  plate  is  to  be 
first  immersed  in  the  pure  water  for  a  moment,  and  transferred  immediately  to  the 
saline  solution,  and  moved  to  and  fro  in  it  to  equalize  the  action  of  the  liquor.  When- 
ever the  yellow  tint  of  the  iodine  is  removed,  the  plate  is  to  be  lifted  out  by  the 
edges,  and  dipped  straightway  in  the  water-trough.  The  apparatus  of  fas.  459,  and  460, 
is  then  brought  into  use,  with  a  vessel  filled  with  distilled  water,  hot^  but  not  boiling. 
The  plate,  when  lifted  out  of  the  water-trough,  is  to  be  placed  immediately  on  the 
inclined  plane  e ;  and  without  allowing  it  time  to  dry,  is  to  be  floated  over  with  the 
hot  distilled  water  from  the  top,  so  as  to  carry  oflF  all  the  saline  matter.  As  the  quick- 
silver which  traces  the  images  will  not  bear  touching,  the  silvered  plate  should  be  se- 
cured by  a  cover  of  glass,  made  tight  at  the  edges  by  pasting  paper  round  them. 

In  Jig.  451,  which  is  a  plan  view  of  the  iodine-box  apparatus,  e  is  an  interior  cover; 
d  is  the  iodine-dish  ;  e  is  the  thin  board  to  which  the  silvered  plate  is  fixed,  as  shown 
at  fg.  450 ;  g  is  the  cover  of  the  box ;  h  h  are  small  rods,  at  the  four  corners  of  the 
inclined  lining,  k,  of  the  box,  to  support  the  lid  c ;  ^'  is  a  gauze  of  wire-cloth  cover,  to 
diffuse  the  iodine  vapor;  k  is  the  wooden  lining,  sloping  like  a  hopper;  d  d,\xi  Jig. 
454,  are  buttons  to  fasten  the  board  on  the  doors;  e  shows  the  thickness  of  the  frame; 
/is  the  silvered  plate.  In  Jig.  461,  a  is  the  ground  glass  of  the  camera;  6  is  a  mirror 
inclined  about  45°  to  the  horizon,  by  means  of  the  rod  /.  The  image  of  the  object  is 
easily  brought  into  focus  by  moving  forward  or  backward  the  sliding-box  d,  in  laying 
hold  of  it  with  both  hands  by  the  projections  a,  Jig.  454.  When  the  focus  is  adjusted, 
the  thumbscrew,  /t,  fixes  the  whole.  The  mirror  is  kept  closed  by  two  hooks  at  /, 
which  take  into  small  eyes  at  g.  The  frame  and  ground  glass  plate  are  withdrawn 
and  replaced  by  the  frame  carrying  the  prepared  plate,  as  represented  hnfg.  448,  with 
the  shading  doors,  h,  open  in  the  camera.  These  doors  and  the  sliding-box  d  are  lined 
with  black  velvet.  The  object  glass  is  achromatic  and  periscopic,  the  concave  being 
outside  in  the  camera;  its  diameter  is  about  3|  inches,  and  focus  about  13  inches.  A 
diaphragm  is  placed  before  the  object  glass,  at  3|  inches  from  it,  and  its  aperture  may 
be  closed  by  a  plate  moving  in  a  pivot.  This  camera  reverses  the  objects  from  left  to 
right;  but  this  may  be  obviated  by  placing  a  plane  mirror  on  the  outside  beyond  the 
aperture  of  the  diaphragm,  as  at  /,  Jig.  456,  where  it  is  fixed  by  means  of  a  screw,  k. 
Loss  of  light  is  thereby  occasioned. 

Fig.  457  is  an  upright  section,  &ndfg.  458,  a  front  elevation  of  the  mercurial  appa- 
ratus, a,  the  cover;  b,  the  black  board,  with  grooves  to  receive  the  board.  A;  e,  the 
cup  of  quicksilver;  d,  the  spirit-lamp;  e,  a  small  cock,  through  whixjh  the  quicksilver 
may  be  run  off,  if  the  apparatus  be  laid  to  one  side ;  /,  the  thermometer ;  g,  a  glass 
window ;  h,  the  board  bearing  the  metallic  plate  ;  /,  a  stand  for  the  spirit-lamp,  which 
is  held  by  the  ring  k,  so  that  its  flame  may  strike  the  bottom  of  the  cup.  The  whole 
of  the  inside  of  the  apparatus  should  be  blackened  and  varnished. 

Mg.  459  is  a  front  view  of  the  washing  apparatus  made  of  tin  plate,  varnished.  The 
plates,  to  be  washed,  are  laid  on  the  angular  ledge,  d;  eisa  ledge  to  conduct  the  water 
to  the  receptacle  c.  Fig.  460  is  a  side  view  of  the  washing  apparatus.  The  patent 
was  enrollea  in  February,  1840.     {See  Newton's  Journal,  C.  S.  xyl,  I.) 

Mr.  Richard  Beard  having  purchased  from  M.  Daguerre  a  license  to  practise  his 
invention  above  described,  received  from  a  foreigner  a  communication  of  certain  im- 
provements, for  which  he  obtained  a  patent  in  June,  1840.  The  first  of  these  is  the 
substitution  of  a  concave  reflecting  mirror  for  the  lens  in  the  camera  obscura.  Fig. 
462  represents  in  section  a  slight  wooden  box,  a  a,  open  at  the  front,  opposite  to 
the  person  sitting  for  the  portrait  In  the  back  part  of  the  box  a  concave  mirror, 
b,  is  placed,  to  reflect  the  rays  coming  from  the  person.  A  small  frame,  f,  is  fixed  to 
an  adjustable  pedestal,  d,  which  slides  in  grooves  in  the  bottom  of  the  box,  for  the 
purpose  of  being  set  at  the  focal  point  of  the  mirror.  In  this  frame,  e,  a  polished 
Burface  is  first  to  be  placed  for  trial,  to  receive  the  image  correctly,  as  observed  by  the 
operator,  by  looking  through  the  opening,  e,  in  the  top  of  the  box.  The  prejjared 
silvered  plate  is  now  substituted  in  the  exact  place  for  the  trial  one.  Tlie  luminous 
impression  being  made,  the  slide,  c^  is  withdrawn,  and  the  plate  removed ;  carefully 
shut  up  in  a  box  from  the  light 

The  second  object  of  this  patent  is  making  the  prepared  surface  more  uniform,  h> 
passing  two  plates,  with  their  silvered  faces  in  contact^  several  times  between  hardened 
rollers,  annealing  them  at  a  low  red  heat  after  each  passage. 

His  third  object  is  to  use  a  compound  of  bromine  and  iodine,  instead  of  the  lattei 
alone,  for  coating  the  silver;  which  increases  its  sensibility  to  light,  thereby  shortening 
and  improving  the  operation  of  taking  likenesses.  He  also  recommends  to  use  a  com- 
bination of  iodine  with  nitric  acid.  Finally,  Mr.  Beard  finds  that  by  placing  a  screen 
of  any  desired  color  behind  the  sitter,  the  appearance  of  his  Daguerreotype  portrait  is 
improved.    {Newton's  Journal,  zziiL,  112.) 


DAGUERROTYPE. 


537 


M.  A.  J.  F.  Claudet,  who  had  also  purchased  a  license  from  M.  Daguerre,  obtained 
a  patent  in  December,  1841,  for  certain  improvements  upon  the  original  process.  His 
first  object  is  to  give  the  front  of  the  camera  obscura  such  an  aperture  as  to  admit 
the  largest  object-glass  intended  to  be  used;  and  of  such  he  provides  a  series  of  dif- 
ferent dimensions,  each  attached  to  its  board,  that  may  be  fitted  by  a  slide  to  the  front 

of  the  camera.  vi—    r 

One  of  the  greatest  difficulties  in  the  Daguerrotype  process  was  the  impossibility  of 
ascertaining  the  precise  moment  at  which  the  light  had  produced,  on  the  prepared 
plate,  the  effect  requisite  for  the  vapor  of  mercury  to  bring  out  the  image.  By  apply- 
ing that  vapor  to  the  plate  while  the  silver  surface  is  being  acted  upon  by  the  ligh^ 
the  operator  is  enabled  to  see  when  his  picture  is  complete.  Another  advantage  of 
this  joint  operation  is,  that  the  effect  of  the  mercury  upon  those  parts  of  the  plate 
which  have  been  acted  upon  by  the  light,  are  more  perfect  when  caused  to  take  place 
immediately  under  the  luminous  influence.  Hence,  instead  of  using  the  distinct  box 
with  the  cup  of  quicksilver,  he  places  a  cup  containing  that  metal  in  the  camera  ob- 
scura, with  its  spirit-lamp,  and  exhales  the  vapors  there.  When  the  mercury  has  risen 
to  the  proper  temperature,  the  aperture  of  the  object-glass  is  thrown  open,  and  the 
light,  reflected  from  the  object  to  be  delineated,  is  allowed  to  operate. 

He  watches  the  effect  through  an  opening  in  the  side  of  the  camera,  where  he  views 
the  prepared  plate  by  the  light  of  a  lantern  passing  through  a  piece  of  red  or  orange- 
colored  glass  in  the  (other)  side  of  the  camera.  Whenever  the  light  and  mercury, 
by  their  simultaneous  action,  have  produced  a  good  image,  the  object-glass  is  covered, 
and  the  silver  plate,  with  its  picture,  removed,  in  order  to  be  washed  and  finished. 
M.  Claudet  embellishes  his  Daguerrotype  portraits  by  placing  behind  the  sitter  screens 
of  painted  scenery,  which  furnish  pleasing  back  grounds.  He  specifies  also  various 
kinds  of  artificial  illumination,  to  L-;  used  in  the  absence  of  solar  light.  {Newton's 
Joumaly  C.  S.  xx.  430.) 

According  to  M.  Barnard,  Daguerre's  iodized  plate  should  be  exposed  for  half  a 
minute  to  the  action  of  chlorine,  mixed  with  a  large  proportion  of  common  air; 
whereby  it  becomes  so  sensitive,  that  the  pictorial  impression  is  produced  in  the  short 
space  of  time  necessary  for  removing  and  replacing  the  screen  of  the  camera.  The 
mercury  is  afterward  employed ;  as  also  the  hyposulphite  wash.  Daguerrotype  pic- 
tures are  colored  by  dusting  over  them  powders  of  proper  hues,  which  are  immediately 
washed  by  passing  the  plate  through  water.  What  remains  of  the  color  after  this  ab- 
lution does  not  seem  in  the  least  to  injure  the  appearance  or  alter  the  form  of  the 
image.  It  would  seem  that  those  parts  of  the  picture  which  were  at  first  black,  retain, 
after  being  washed,  a  larger  proportion  of  the  coloring  matter  than  the  lighter  parts. 

Several  valuable  improvements  seem  to  have  been  made  in  Vienna  upon  the  Da- 
guerrotype process ;  and  among  others,  the  mode  of  using  chloriodine. 

The  best  form  of  box  for  applying  the  chloriodic  vapor  is  square,  with  its  bottom  of 
plate  glass,  supported  a  little  above  the  table  by  feet,  a  thumb-screw  being  one  of 
them,  in  order  to  give  a  certain  inclination  to  the  glass  plate  for  spreading  the  chlor- 
iodine over  it  uniformly.  A  sheet  of  white  paper  being  laid  beneath  the  box,  enables 
the  operator  to  see  whether  the  liquid  chloriodine  is  properly  distributed.  There  is  a 
groove  round  the  top  of  the  box,  into  which  the  letlge  of  the  lid  fits  tight.  A  thermom- 
eter is  placed  in  the  box. 

Voigtlatd*s  lenses  consist  of  two  achromatic  object-glasses  placed  apart ;  the  first  near- 
est the  object,  having  an  aperture  of  18  lines  ;  the  second  one  of  19  lines ;  the  solar  fo- 
cus of  the  two  is  5J  fnches.  A  system  of  lenses  of  so  short  a  focus  with  so  large  aper- 
tures affords  from  1 1  to  12  times  more  illumination  than  Daguerre's  original  apparatus 
did.  The  finest  p)rtraits  can  be  produced  in  the  course  of  from  10  to  30  seconds  with 
this  arranjjement.  Such  an  apparatus,  elegantly  made  in  brass,  costs  only  120  gulden, 
or  about  10  guineas. 

Voigtland  has  recently  made  a  camera  with  two  object-glasses,  as  above  arranged, 
each  having  an  aperture  of  37  lines,  and  a  combined  focus  of  12  inches.  By  means  of 
this  instrument,  portraits  5^  inches  in  size  can  be  made.  The  landscapes  produced  in 
them  are  very  beautiful.  Its  price  is  144  gulden,  about  12  guineas.  Along  with  the 
above  apparatus,  a  box  with  a  bdttom  of  amalgamated  copper  is  used  for  applying  the 
vapor  of  mercury.  . 

By  peculiar  methods  of  polishing  the  silvered  copper  plate,  peculiar  tones  and  tints 
may  be  given  to  the  picture.  The  olive-oil  and  pumice-powder  are  indispensable  for 
i«moving  the  scratches  from  the  plate  and  to  render  its  surface  uniform.  If  a  delicate 
blue  tone  be  desired,  the  plate  should  be  a  second  time  polished  with  sulphuric  ether 
and  washed  tripoli ;  and  a  third  time  with  dilute  nitric  acid  and  Paris  red,  rubbing  the 
plate  lastly  with  a  peace  of  washleather  and  crocus.  But  if  a  brownish  black  tone  be 
wished  for,  a  like  series  of  operations  is  to  be  gone  through,  only  instead  of  the  ether 
and  tripoli,  spirit  of  ammonia  and  Vienna  lin^e  is  to  be  used. 


568 


DAMASCUS  BLADES. 


DAMASK. 


569 


To  give  the  plate  the  utmost  sensibility  to  light,  a  film  of  iodine  should  be  given  in 
the  first  place.     If  with  dry  iodine,  this  should  be  strewed,  then  covered  with  cotton, 
and  lastly  with  a  sheet  of  paper,  and  the  plate  above  the  last,  but  not  so  as  to  touch  it. 
This  may  be  done  also  with  a  solution  of  1  part  of  iodine  in  6  of  spirits  of  wine,  put 
into  a  saucer,  which  is  laid  on  the  bottom  of  the  box,  and  covered  with  gauze.    The 
plate  is  to  be  removed  whenever  it  has  acquired  a  faint  brazen  tint.     By  this  means  the 
plate  receives  the  impressions  of  light  so  well  as  to  produce  good  contrasts  between  the 
white  and  the  dark  places.     The  application  of  bromine  afterward  causes  a  rapid 
reception  of  the  image,  and  occasions  the  deep  black  shades  of  an  object.     The  best 
form  is  brome  water,  made  by  dissolving  the  bromine  in  a  little  distilled  water,  and  then 
adding  more,  when  it  is  wanted,  till  the  solution  acquires  a  straw-yellow  color.    A 
delicate  thermometer  being  put  into  the  box,  the  solution  is  to  be  spread  uniformly  on 
its  glass  b*)ttom,  the  plate  being  laid  on  above  and  covered  up,  while  the  time  of  expo 
sure  must  ye  counted  by  seconds,  with  a  clock  or  watch.    If  the  temperature  be 
41°  F.,  the  time  should  be  258  seconds. 

50^  230    — 

89*  201    — 

68*  158    — 

IT  113     — 

By  attending  to  these  instructions,  exact  results  may  be  always  obtained. 
A  second  mode  of  experimenting  is  with  bromiodine ;  prepared  by  dissolving  1  part 
of  bromine  in  an  alcoholic  solution  of  5  parts  of  iodine;  and  diluting  this  mixture  with 
water,  till  it  acquires  the  color  of  Bavarian  beer.  The  action  of  this  application  upon 
the  plate  is  so  rapid  as  hardly  to  leave  time  for  consideration.  It  must  be  watched  ev- 
ery instant  till  the  dark  gold  yellow  tint  appear,  when  it  is  ready  for  the  camera. 

The  best  time  of  day  for  Daguerrotype  operations  is  from  an  hour  after  the  sun  rises 
till  he  comes  within  45®  of  the  meridian,  and  not  again  till  he  has  passed  the  meridian 
by  45**.  When  the  sitting  is  too  long,  the  parts  which  should  be  pure  white  become 
of  a  dirty  blue  tint,  and  the  dark  parts  become  brown.  The  picture  is  burnt,  so  to 
speak. 

Chloride  of  gold  applied  to  the  picture  has  the  efiect  of  fixing  and  enlivening  the 
tints.  A  small  graie  being  fixed  by  a  clamp  to  the  edge  of  a  table,  the  plate  is  laid 
upon  it  with  the  image  uppermost,  and  overspread  evenly  with  solution  of  chloride  of 
gold,  by  means  of  a  fine  broad  camel-hair  brush,  without  letting  any  drop  over  the  edge. 
A  spirit  lamp  is  now  brought  under  the  plate,  and  moved  to  and  fro  till  a  number  of 
amall  steam  bubbles  appear  upon  the  image.  The  spirit  lamp  must  be  immediately 
withdrawn.  The  remainder  of  the  chloride  solution  must  be  poured  back  into  the  phia), 
to  be  used  on  another  occasion.  It  is  lastly  to  be  washed  and  examined.  This  opera- 
tion has  been  repeated  three  or  four  times  with  the  happiest  effect,  of  giving  fixity  and 
force  to  the  picture.     It  may  then  be  wiped  with  cotton  without  injury. 

By  dusting  various  pigment  powders  from  small  cotton-wool  dossils  npon  the  picture^ 
previously  coated  with  an  alcoholic  solution  of  copal,  and  nearly  dry,  the  appearance  of  a 
colored  miniature  has  been  very  successfully  imitated.  The  varnish  must  be  applied 
delicately  with  one  stroke  of  a  broad  brush  of  badger  hair.* 

DAOTJERREoryPE  Engraving.  This  new  art,  patented  by  M.  A.  F.  J.  Claudet  on  the 
2l8t  November,  1843,  is  established  on  the  following  facts.  A  mixed  acid,  consisting 
of  water,  nitric  acid,  nitrate  of  potash,  and  common  salt,  in  certain  proportions,  being 
poured  upon  a  Daguerreotype  picture,  attacks  the  pure  silver,  forming  a  chloride  of 
that  metal,  but  does  not  aft'ect  the  w^hite  parts,  which  are  produced  by  the  mercury  of 
the  picture.  This  action  does  not  last  long.  Water  of  ammonia,  containing  a  little 
chloride  of  silver  in  solution,  dissolves  the  rest  of  that  chloride,  which  is  then  washed 
away,  leaving  the  naked  metal  to  be  again  attacked,  especially  with  the  aid  of  heat. 
The  metallic  surface  should  have  been  perfectly  purified  by  means  of  alcohol  and  caus- 
tic potass.  For  the  rest  of  the  ingenious  but  complex  details,  see  Newton's  Jtmrnal, 
C.  S.,  vol.  XXV.,  p.  112. 

DAPILINE,  the  same  as  Inuline,  the  fecula  obtained  from  elecampane,  analogous  in 
many  respects  to  starch.     It  is  not  employed  in  the  arts. 

DAMASCUS  BLADES,  are  swords  or  scymitars,  presenting  upon  their  surface  n  va- 
riegated appearance  of  watering,  as  white,  silvery,  or  black  veins,  in  fine  lines,  or  fillets; 
fibrous,  crossed,  interlaced  or  parallel,  <fec  They  are  brought  from  the  East  being  fab- 
ricated chiefly  at  Damascus,  whence  their  name.  Their  excellent  quality  has  become 
proverbial ;  for  which  reason  these  blades  are  much  sought  after  by  military  men,  and 
are  high  priced.  The  oriental  processes  have  never  been  satisfactorily  described  ;  but 
of  late  years  methods  have  been  devised  in  Europe  to  imitate  the  fabric  very  well. 


*  See  Praktiscbc  Anweisung  aura  Daguerrotypiren,  Leipzig.  &c.    1843. 


I 


i 


Clouet  and  Hachette  pointed  out  the  three  following  processes  for  producing  Da* 
mascus  blades  :  1,  that  of  parallel  fillets ;  2,  that  by  torsion ;  3,  the  mosaic.  The  first, 
which  is  still  pursued  by  some  French  cutlers,  consists  in  scooping  out  with  a  graving 
tool  the  faces  of  a  piece  of  stuff  composed  of  thin  plates  of  different  kinds  of  steel. 
These  hollows  are  by  a  subsequent  operation  filled  up,  and  brought  to  a  level  with  the 
external  faces,  upon  which  they  subsequently  form  tress-like  figures.  2.  The  method  of 
torsion  which  is  more  generally  employed  at  present,  consists  in  forming  a  bundle  of 
rods  or  slips  of  steel,  which  are  welded  together  into  a  well-wrought  bar,  twisted 
several  times  round  its  axis.  It  is  repeatedly  forged,  and  twisted  alternately ;  aftei 
which  it  is  slit  in  the  line  of  its  axis,  and  the  two  halves  are  welded  with  their  outsidei 
in  contact ;  by  which  means  their  faces  will  exhibit  very  various  configurations.  3.  Th« 
mosaic  method  consists  in  preparing  a  bar,  as  by  the  torsion  plan,  and  cutting  this  bai 
into  short  pieces  of  nearly  equal  length,  with  which  a  fagot  is  formed  and  welded 
together;  taking  care  to  preserve  the  sections  of  each  piece  at  the  surface  of  the  blade. 
In  this  way,  all  the  variety  of  the  design  is  displayed,  corresponding  to  each  fragment  of 
the  cut  bar. 

The  blades  of  Clouet,  independently  of  their  excellent  quality,  their  flexibility,  and 
extreme  elasticity,  have  this  advantage  over  the  oriental  blades,  that  they  exhibit  in  the 
very  substance  of  the  metal,  designs,  letters,  inscriptions,  and,  generally  speaking,  all 
kinds  of  figures  which  had  been  delineated  beforehand. 

Notwithstanding  these  successful  results  of  Clouet,  it  was  pretty  clear  that  the  watered 
designs  of  the  true  Damascus  cimeter  were  essentially  different.  M.  Breant  has  at 
last  completely  solved  this  problem.  He  has  demonstrated  that  the  substance  of  the 
oriental  blades  is  a  cast-steel  more  highly  charged  with  carbon  than  our  European  steels, 
and  in  which,  by  means  of  a  cooling  suitably  conducted,  a  crystallization  lakes  place 
of  two  distinct  combinations  of  carbon  and  iron.  This  separation  is  the  essential  condi- 
tion ;  for  if  the  melted  steel  be  suddenly  cooled  in  a  small  crucible  or  ingot,  there  is  no 
damascene  appearance. 

If  an  excess  of  carbon  be  mixed  with  iron,  the  whole  of  the  metal  will  be  converted 
into  steel;  and  the  residuary  carbon  will  combine  in  a  new  proportion  with  a  portion  of 
the  steel  so  formed.  There  will  be  two  distinct  compounds ;  namely,  pure  steel,  and 
carbureted  steel  or  cast-iron.  These  at  first  being  imperfectly  mixed  will  tend  to 
separate,  if  while  still  fluid  they  be  left  in  a  state  of  repose ;  and  form  a  crystallization 
in  which  the  particles  of  the  two  compounds  will  place  themselves  in  the  crucible  in  an 
order  determined  by  their  aflinity  and  density  conjoined.  If  a  blade  forged  out  of  steel 
so  prepared  be  immersed  in  acidulous  water,  it  will  display  a  very  distinct  Damascus 
appearance;  the  portions  of  pure  steel  becoming  black,  and  those  of  carbureted  steel 
remaining  white,  because  the  acids  with  difficulty  disengage  its  carbon.  The  slower 
such  a  compound  is  cooled,  the  larger  the  Damascus  veins  will  be.  Travernier  relates 
that  the  steel  crucible  ingots,  like  those  of  wootz,  for  making  the  true  oriental  Damascus, 
come  from  Golconda,  that  they  are  of  the  size  of  a  halfpenny  roll,  and  when  cut  in  two, 
form  two  swords. 

Steel  combined  with  manganese  forges  easily,  but  it  is  brittle  when  cold ;  it  display* 
however  the  Damascus  appearance  very  strongly. 

A  mixture  of  100  parts  of  soft  iron,  and  2  of  lamp  black,  melts  as  readily  as  ordinary 
steel.  Several  of  the  best  blades  which  M.  Breant  presented  to  the  Societe  d'Encourage- 
ment  are  the  product  of  this  combination.  This  is  an  easy  way  of  making  cast-steel 
without  previous  cementation  of  the  iron.  100  parts  of  filings  of  verj'  gray  cast-iron,  and 
100  parts  of  like  filings  previously  oxydized,  produced,  by  their  fusion  together,  a  beautiful 
damascene  steel,  fit  for  forging  into  white  arms,  sabres,  swords,  &c.  This  compound  is 
remarkable  for  its  elasticity,  an  essenial  quality,  not  possessed  by  the  old  Indian  steel. 
The  greater  the  proportion  of  the  oxydized  cast-iron,  the  tougher  is  the  steel.  Care  should 
be  taken  to  stir  the  materials  during  their  fusion,  before  it  is  allowed  to  cool ;  otherwise 
they  will  not  afford  a  homogeneous  damasc.  If  the  steel  contains  much  carbon  it 
is  difficult  to  forge,  and  cannot  be  drawn  out  except  within  a  narrow  range  of  temperature. 
When  heated  to  a  red-white  it  crumbles  under  the  hammer ;  at  a  cherry-red  it  becomes 
hard  and  brittle;  and  as  it  progressively  cools  it  becomes  still  more  unmalleable.  It  re- 
sembles completely  Indian  steel,  which  European  blacksmiths  cannot  forge,  because  they 
are  ignorant  of  the  suitable  temperature  for  working  it.  M.  Breant,  by  studying  this 
point,  succeeded  in  forging  fine  blades. 

Experience  has  proved  that  the  orbicular  veins,  called  by  the  workmen  knots  or 
thorns  (ronces),  which  are  seen  upon  the  finest  Eastern  cimeters,  are  the  result  of  the 
manner  of  forging  them,  as  well  as  the  method  of  twisting  the  Damascus  bars.  If 
these  be  drawn  in  length,  the  veins  will  be  longitudinal ;  if  they  be  spread  equally  in  all 
directions,  the  stuff  will  havo  a  crystalline  aspect;  if  they  be  made  wavy  in  the  two 
directions,  undulated  veins  will  be  produced  like  those  in  the  oriental  Damascus. 

DAMASK  is  a  variegated  textile  fabric,  richly  ornamented  with  figures  of  flowers. 


570 


DAMASKEENING. 


fruits,  landscapes,  animals,  &c.,  woven  in  the  loom,  and  is  by  far  the  most  rich,  elegant, 
and  expensive  species  of  ornamental  weaving,  tapestry  alone  excepted.  The  name  is 
mid  to  be  derived  from  Damascus,  where  it  was  anciently  made. 

Damask  belongs  to  that  species  of  texture  which  is  distinguished  by  practical  men  by 
the  name  of  tweeline,  of  which  it  is  the  richest  pattern.  The  tweel  of  damask  is  usually 
half  that  of  full  satin,  and  consequently  consists  of  eight  leaves  moved  either  in  regulai 
succession  or  by  regular  intervals,  eight  leaves  being  the  smallest  number  which  will  ad- 
mit of  alleniate  tweeling  at  equal  intervals. 

In  the  article  Carpet,  two  representations  have  been  given  of  the  damask  draw- 
loom. 

The  generic  difference  of  tweeling,  when  compared  with  common  cloth,  consists  in  the 
intersections,  although  uniform  and  equidistant,  being  at  determinate  intervals,  and  not  be- 
tween the  alternate  threads.  Hence  we  have  specimens  of  tweeled  cloth,  where  the  in- 
tersections take  place  at  the  third,  fourth,  fifth,  sixth,  seventh,  eighth,  or  sixteenth  interval 
only.  The  threads  thus  deflecting  only  from  a  straight  line  at  intervals,  jreserve  more 
of  their  orisinal  direction,  and  a  much  greater  quantity  of  materials  can  be  combined  in 
an  equal  space,  than  in  the  alternate  intersection,  where  the  tortuous  deflection,  at  every 
interval,  keeps  them  more  asunder.  On  this  principle  tweeled  cloths  of  three  and  four 
leaves  are  woven  for  facility  of  combination  alone.  The  coarser  species  of  ornamented 
cloths,  known  by  the  names  of  dornock  and  diaper,  usually  intersect  at  the  fifth,  or  half 
satin  interval.  The  sixth  and  seventh  are  rarely  used,  and  the  intersection  at  the 
eighth  is  distinguished  by  the  name  of  satin  in  common,  and  of  damask  in  ornamental 
tweeling.  It  will  further  be  very  obvious,  that  where  the  warp  and  woof  cross  only  at 
every  eighth  interval,  the  two  sides  of  the  cloth  will  present  a  diversity  of  appearance; 
for  on  one  side  the  longitudinal  or  warp  threads  will  run  parallel  from  one  end  of  a  web 
to  the  other,  and,  on  the  other,  the  threads  of  woof  will  run  also  parallel,  but  in  a  trans- 
verse direction  across  the  cloth,  or  at  right  angles  to  the  former.  The  points  of  intersec- 
tion being  only  at  every  eighth  interval,  appear  only  like  points ;  and  in  regular  tweeling 
these  form  the  appearance  of  diagonal  lines,  inclined  at  an  angle  of  45°  (or  nearly  so)  to 
each  of  the  former. 

The  appearance,  therefore,  of  a  piece  of  common  tweeled  cloth  is  very  similar  to  that 
of  two  thin  boards  glued  together,  with  the  grain  of  the  upper  piece  at  right  angles  to 
that  of  the  under  one.  That  of  an  ornamental  piece  of  damask  may,  in  the  same  man- 
ner, be  very  properly  assimilated  to  a  piece  of  veneering,  where  all  the  wood  is  of  the 
same  substance  and  color,  and  where  the  figures  assume  a  diversity  of  appearance  from 
the  ground,  merely  by  the  grain  of  the  one  being  disposed  perpendicularly  to  that  of  the 
other.     See  Textile  Fabric. 

From  this  statement  of  the  principle,  it  results  that  the  most  unlimiced  variety  of  figures 
will  be  produced,  by  constructing  a  loom  by  which  every  individual  thread  of  warp  may 
be  placed  either  above  or  below  the  woof  at  every  intersection ;  and  to  effect  this,  in 
boundless  variety,  is  the  object  of  the  Jacquard  mounting ;  which  see. 

The  chief  seat  of  this  manufacture  is  probably  the  town  and  neighborhood  of  Dun- 
fermline, in  Fifeshire,  and  Lisburn  and  Ardoyne,  near  Belfast,  where  it  is  considered  as 
the  staple,  having  proved  a  very  profitable  branch  of  traffic  to  the  manufacturer,  and 
given  employment  to  many  industrious  people. 

The  material  used  there  is  chiefly  linen ;  but  many  have  been  recently  woven  of  cotton, 
since  the  introduction  of  that  article  into  the  manufacture  of  cloth  has  become  so  prev- 
alent. The  cotton  damasks  are  considerably  cheaper  than  those  of  linen ;  but  are  not 
considered  either  so  elegant  or  durable.  The  cotton,  also,  unless  frequently  bleached,  does 
not  preserve  the  purity  of  the  white  color  nearly  so  well  as  the  linen. 

DAMASKEENING ;  the  art  of  ornamenting  iron,  steel,  &c.,  by  making  incisions  upon 
its  surface,  and  filling  them  up  with  gold  or  silver  wire ;  chiefly  used  in  enriching  sword 
blades,  guards,  and  gripes,  locks  of  pistols,  &,c. 

Its  name  shows  the  place  of  its  origin,  or,  at  least,  the  place  where  it  has  been  prac- 
tised in  the  greatest  perfection ;  viz.,  the  city  of  Damascus,  in  Syria ;  though  M.  Felibiea 
attributes  the  perfection  of  the  art  to  his  countryman,  Cursinet,  who  wrought  under  the 
reisrn  of  Henry  IV. 

Damaskeening  is  partly  mosaic  work,  partly  engraving,  and  partly  carving.  As  mosaic 
work  it  consists  of  pieces  inlaid ;  as  engraving,  the  metal  is  indented,  or  cut  in  intaglio  | 
and  as  carving,  gold  and  silver  are  wrought  into  it  in  relievo. 

There  are  two  ways  of  damaskeening ;  in  the  first,  which  is  the  most  beautiful,  tha 
artists  cut  into  the  metal  with  a  graver,  and  other  tools  proper  for  engraving  upon 
steel,  and  afterwards  fill  up  the  incisions,  or  notches,  with  a  pretty  thick  silver  or  gold 
wire.  In  the  other,  which  is  only  superficial,  they  content  themselves  to  make  hatches, 
or  strokes  across  the  iron,  <fec.,  with  a  cutting  knife,  such  as  is  used  in  making  sidmL 
files.     As  to  the  firsts  it  is  necessary  for  the  gravings  or  incisions  to  be  made  in  the  dove 


DECOMPOSITION. 


571 


4 


tail  form;  that  the  gold  or  silver  wire,  which  is  thrust  forcibly  into  them,  may  adhere  the 
more  strongly.  As  to  the  second,  which  is  the  more  usual,  the  method  is  this :— Having 
heated  the  steel  till  it  changes  to  a  violet,  or  blue  color,  they  hatch  it  over  and  across 
with  the  knife ;  then  draw  the  ensign  or  ornament  intended,  upon  this  hatching,  with  a 
fine  brass  point  or  bodkin.  This  done,  they  take  fine  gold  wire,  and  conducting  or  chasing 
it  according  to  the  figures  already  designed,  they  sink  it  carefully  into  the  hatches  of  thr 
metal  with  a  copper  tool. 

DAMASSIN  IS  a  kind  of  damask,  with  gold  and  silver  flowers,  woven  in  the  warp  an^i 
wof)f ;  or  occasionally  with  silk  organzine. 

DAMPS,  in  mining,  are  noxious  exhalations,  or  rather  gases,  so  called  from  the  German 
damp/,  vapor.  There  are  two  principal  kinds  of  mine  gases,  the  fire-dampy  or  carbureter* 
hydrogen,  and  the  choke-damp,  or  carbonic  acid  gas.     See  Mines. 

DAPHNINE  ;  the  bitter  principle  of  the  Daphne  Mpina. 

DATOLITE.     A  mineral  composed  of  silica,  lime,  and  boracic  acid. 

DECANTATION  (Eng.  and  Fr. ;  Jbgiessen,  Germ.)  is  the  act  of  pouring  off  the  clear 
supernatant  fluid  from  any  sediment  or  deposile.  It  is  mucn  employed  in  the  chemical 
arts ;  and  is  most  conveniently  effected  by  a  syphon. 

DECOCTION  (Eng.  and  Fr. ;  Mkochungy  Germ.)  means  either  the  act  of  boiling 
a  liquid  along  with  some  organic  substance,  or  the  liquid  compound  resulting  from  that 

act 

DECOMPOSITION  (Eng.  and  Fr. ;  Zersetzung,  Germ.)  is  the  separation  of  the  con- 
stituent principles  of  any  compound  body.  The  following  table,  the  result  of  important 
researches  recently  made  by  M.  Persoz,  Professor  of  Chemistry  at  Strasburgh,  shows  the 
order  in  which  decompositions  take  place  among  the  successive  substances. 


Nitric  Acid. 

Oxyde  of  Magnesium 

—  Silver 

—  Cobalt 

—  Nickel 
Protox.  of  Cerium 
Oxyde  of  Zinc 
Protox.  of  Manganese 
Oxyde  of  Lead 

: —        Cadmium 

—  Copper 

—  Glucinum 

—  Alumium 

—  Uranium 

—  Chromium 
Protox.  of  Mercury 
Oxyde  of  Mercury 

—  Iron 

—  Bismuth 


Muriatic  Acid. 

Oxyde  of  Magnesium 

—  Cobalt 

—  Nickel 
Protox.  of  Mercury 

—  Cerium 
Oxyde  of  Zinc 
Protox.  of  Manganese 

—  Iron 

—  Uranium 

—  Copper 

—  Tin 
Oxyde  of  Glucinum 

—  Alumium 

—  Uranium 

—  Chromium 

—  Iron 

—  Tin 

—  Bismuth 


—        Antimony 

By  means  of  the  cupric  oxyde  we  may  separate,  1,  the  ferric  oxyde  from  the  manganoits 
oxyde ;  2,  the  cobaltic,  nickelic,  zincic  and  cerous  oxydes  from  the  uranic,  ferric,  chromic, 
and  aluminic  oxydes ;  3,  the  ferrous  oxyde  from  the  chromic  oxyde,  when  dissolved  in  the 
muriatic  acid. 

In  boiling  a  muriatic  solution  of  the  cobaliic,  nickelic,  and  manganous  oxydes,  with  the 
mercuric  oxyde,  the  first  two  oxydes  alone  are  precipitated.  Alumina  separates  the  cad- 
mic  oxyde  from  the  bismuthic  oxyde,  the  stannous  oxyde  from  the  stannic  oxyde,  and  the 
Stannous  oxyde  from  the  antimonic  acid.  The  cupric  oxyde  separates  also  by  precipita- 
tion, the  aluminic,  uranic,  chromic,  titanic,  and  vanadic  oxydes  from  all  the  oxydes  which 
are  precipitable  in  the  state  of  sulphuret,  by  hydrosulphoret  of  ammonia. 

As  an  example  of  this  mode  of  analysis — 

Dissolve  pech-blende  in  aqua  regia,  precipitate  its  copper  by  sulphureted  hydrogen, 
boil  the  liquid  along  with  nitric  acid,  in  order  to  transform  all  the  uranium  into  uranic 
acid.  Next  boil  it  along  with  cupric  oxyde,  which  precipitates  only  the  uranic  and  ferric 
oxydes.  Redissolve  the  precipitate  in  nitric  acid,  and  boil  the  solution  with  mercuric 
oxyde,  which  does  not  precipitate  the  ferric  oxyde.  Finally,  separate  the  copper  and  the 
mercury  from  the  uranium,  by  means  of  sulphureted  hydrogen.  In  this  process  we  may 
substitute  plumbic  oxyde  for  the  cupric  oxyde,  and  succeed  equally  well. 

Knowledge,  like  the  above,  of  the  elective  affinities  and  habitudes  of  chemical  bodies, 
simple  and  compound,  imparts  to  its  possessor  an  irresistible  power  over  the  unions  and 


572 


DEPOSITION  OF  METALS. 


I 


iisunioM  of  tlie  elements,  which  he  can  exercise  with  certainty  in  effecting  innumerable 
transformations  in  the  arts. 

DECREPITATION  (Eng.  and  Fr. ;  Verknisiem,  Germ.)  is  the  crackling  noise^ 
attended  with  the  flying  asunder  of  their  parts,  made  by  several  salts  and  minerals, 
when  heated.  It  is  caused  by  the  unequal  sudden  expansion  of  their  substance  by  the 
heat.  Sulphate  of  baryta,  chloride  of  sodium,  calcareous  spar,  nitrate  of  baryta,  and  many 
more  bodies  which  contain  no  water,  decrepitate  most  violently,  separating  at  the  natural 
joints  of  their  crystalline  structure.  Some  chemists  have  preposterously  enough  ascribed 
the  phenomenon  to  the  expansion  of  the  combined  water  into  steam.  What  a  specimen 
of  inductive  philosophy  ! 

DEFECATION  (Eng.  and  Fr. ;  Klaren,  Germ.),  the  freeing  from  dregs  or  impurities. 

DEFLAGRATION  (Eng.  and  Fr.  ;  Verpuffung,  Germ.),  the  sudden  blazing  up  of  a 
combustible;  as  of  a  charcoal  or  sulphur  when  thrown  into  melted  nitre. 

DELPHINIA.  The  vegeto-alkaline  principle  of  the  Delphinium  staphysagria,  or 
stavesacre.    It  is  poisonous. 

DELIQUESCENT  (Zerjliessen^  Germ.)  is  said  of  a  softd  which  attracts  so  much 
moisture  from  the  air  as  to  become  spontaneously  soft  or  liquid ;  such  as  potash  and 
muriate  of  lime. 

DEPHLEGMATION  is  the  process  by  which  liquids  are  deprived  of  theii  watery  par- 
ticles. It  is  applied  chiefly  to  spirituous  liquors,  and  is  now  nearly  obsolete,  as  involving 
the  alchemistical  notion  of  a  peculiar  principle  called  phlegm. 

DEPHLOGISTICATED ;  deprived  of  phlogiston,  —  formerly  supposed  to  be  the 
common  combustible  principle.  It  is  nearly  synonymous  with  oxygenated.  The  idea 
originally  attached  to  the  word  having  proceeded  from  false  logic,  the  word  itself  should 
never  be  used  either  in  science  or  manufactures. 

DEPILATORY  (Depilatoire,  Fr. ;  Enthaarensmittel,  Germ.)  is  the  name  of  any 
substance  capable  of  removing  hairs  from  the  human  skin  without  injuring  its  texture. 
They  act  either  mechanically  or  chemically.  The  first  are  commonly  glutinous 
plasters  formed  of  pitch  and  rosin,  which  stick  so  closely  to  the  part  of  the  skin  where 
they  are  applied,  that  when  removed,  they  tear  away  the  hairs  with  them.  This  method 
is  more  painful,  but  less  dangerous  than  the  other,  which  consists  in  the  solvent 
action  of  a  menstruum,  so  energetic  as  to  penetrate  the  pores  of  the  skin,  and  destroy 
the  bulbous  roots  of  the  hairs.  This  is  composed  either  of  caustic  alkalis,  sulphuret  of 
baryta,  or  arsenical  preparations.  Certain  vegetable  juices  have  also  been  recommended 
for  the  same  purpose;  as  spurge  and  acacia.  The  bruised  eggs  of  ants  have  likewise 
been  prescribed.  But  the  oriental  rusma  yields  to  nothing  in  depilatory  power. 
Gadet  de  Gassincourt  has  published  in  the  Dictionnaire  des  Sciences  Medicalesj  the  follow- 
ing recipe  for  preparing  it. 

Mix  two  ounces  of  quicklime  with  half  an  ounce  of  orpiment  or  realgar,  (sulphuret 
of  arsenic ;)  boil  that  mixture  in  one  pound  of  strong  alkaline  ley,  then  try  its  strength 
by  dipping  a  feather  into  it,  and  when  the  flue  falls  off,  the  rusma  is  quite  strong  enough. 
It  is  applied  to  the  human  skin  by  a  momentary  friction,  followed  by  washing  with 
warm  water.  Such  a  caustic  liquid  should  be  used  with  the  greatest  circumspection, 
beginning  with  it  somewhat  diluted.  A  soap  is  sometimes  made  with  lard  and  the 
above  ingredients ;  or  soft  soap  is  combined  with  them ;  in  either  case  to  form  a  depila- 
tory  pommade.  Occasionally  one  ounce  of  orpiment  is  taken  to  eight  ounces  of  quicklime, 
or  two  to  twelve,  or  three  to  fifteen ;  the  last  mixture  being  of  course  the  most  active. 
Its  causticity  may  be  tempered  by  the  addition  of  one  eighth  of  starch  or  rye  flour,  so  as 
to  form  a  soft  paste,  which  being  laid  upon  the  hairy  spot  for  a  few  minutes,  usually  car- 
ries away  the  hairs  with  it. 

The  rusma  should  never  be  applied  but  to  a  small  surface  at  a  time,  for  independently 
of  the  risk  of  corroding  the  skin,  dangerous  consequences  might  ensue  from  absorption 
of  the  arsenic. 

DEPOSITION  OF  METALS.  Felted  fabrics  have  been  coated  with  metals  of 
various  kinds,  by  means  of  electricity,  in  the  following  way : — A  plate  of  copper,  fof 
example,  as  a  dye  or  matrix,  is  coated  on  one  side  with  a  resinous,  non-conducting 
varnish,  and  on  the  other  with  graphite  or  plumbago,  and  the  cloth  is  strained  over  it^ 
and  cemented  to  it  The  matrix  being  immersed  in  a  solution  of  sulphate  of  copper, 
and  connected  with  a  zinc  pole  of  a  galvanic  battery ;  while  another  plate  of  copper  ia 
immersed  in  the  solution  and  connected  with  the  copper  pole  of  the  battery,  the  depo* 
sition  of  the  metal  upon  the  matrix  commences.  When  the  surface  of  the  matrix  ii 
covered  with  a  thin  film  of  copper,  the  depositing  metal  begins  to  penetrate  the  inter- 
stices of  the  cloth,  and  if  the  operation  is  continued  sufticiently  long,  will  appear  in  small 
globules  at  the  other  side.  As  soon  as  the  required  thickness  of  metal  has  been  de- 
posited, the  matrix  is  removed  from  the  solution,  and  the  cloth  separated  therefrom. 
The  surface  of  the  metallic  coating  will  be  either  plain  or  ornamented,  according  as  the 


♦ 


DEXTRINE. 


573 


surface  of  the  matrix  is  prepared,  whether  with  a  raised  or  sunk  pattern.  And  the 
noetallic  deposit  may  be  afterward  gilt  or  otherwise  ornamented.  Other  details  are 
given  in  the  specification  of  M.  Julius  Schatlaender. — Newtoti's  Journal,  C.  S.,  xxv.,  96. 

DESICCATING  APPARATUS.  The  useful  problem  of  depriving  timber  of  its 
moisture  has  received  a  complete  solution  by  Messrs.  Davison  «fe  Symington,  who  in 
November,  1843,  patented  a  method  of  transmitting  currents  of  air  highly  heated  (by 
an  arrangement  smiilar  to  those  employed  in  the  hot  blast  of  iron-smelting),  through 
casks  made  of  green  wood,  or  through  chambers  in  which  the  deals  or  planks  are  piled 
up.  The  same  means  have  since  been  found  effective  for  cleansing  old  tainted  beer 
tuns,  or  wine  hogsheads,  of  their  fermentative  qualities ;  and  hence  they  are  now  very 
generally  had  recourse  to  in  breweries.  A  fan  or  other  blowing  machine  is  used  for 
propelling  the  heated  air.  Mechanical  friction  with  chains  or  otherwise  is  used  in  con- 
junction with  the  ventilating  process. 

Desiccating  System,  "  When  we  first  noticed  this  system  we  instanced  its  application 
to  the  seasoning  of  beer  casks,  as  the  most  striking  exemplification  of  its  eflScacy  which 
then  offered  itself  to  our  observation;  but  though  we  have  been  fully  borne  out  in  our 
views  of  the  importance  of  that  application,  by  the  subsequent  adoption  of  Messrs. 
Davison  &  Symington's  plans  in  some  of  the  largest  breweries  in  the  kingdom,  this 
turns  out  to  be,  after  all,  but  one  of  the  least  of  the  triumphs  which  the  system  has 
achieved.  From  the  seasoning  of  casks  the  patentees  have  gone  on,  step  by  step,  till 
they  now  undertake  seasoning  of  wood  and  wooden  articles  of  every  description  ;  and 
give  fair  promise  of  benefiting  largely,  not  only  every  art  and  manufacture  of  which 
wood  is  an  element,  but  the  public  at  large.  We  have  been  obligingly  permitted  by 
them  to  inspect  and  make  extracts  from  their  '  Dry  Seasoning  Book,'  and  some  of 
these  extracts  afford  the  best  possible  proofs  of  the  advantages  derivable  from  this  des- 
iccating system.  They  are  records  of  work  actually  done — not  by  way  of  experiment 
merely,  but  in  the  ordinary  course  of  an  established  and  fast  increasing  trade.  Each 
extract  shows,  first,  the  weight  of  the  wood  when  sent  in  to  be  seasoned ;  next,  the 
daily  diminution  in  weight  produced  by  the  desiccating  process ;  and  lastly,  the  total 
quantity  of  moisture  expelled — moisture  which  if  allowed  to  remain  in  the  wood  could 
tend  only  to  produce  rot  and  decay.  The  extracts  give  also,  in  the  case  of  planks,  the 
degree  of  shrinkage  in  width  produced.  Some  of  the  results  are  exceedingly  startling. 
Mahogany  is  reduced  in  weight  by  desiccation  24*4  per  cent,  and  pine  planks  34-5. 
The  woods  least  affected  are  fir  and  white  deal,  which  lose  12-60  per  cent  The  de- 
gree of  shrinkage  produced  is  still  more  remarkable;  amounting,  in  both  the  cases  no- 
ticed, to  no  less  than  three  fourths.  It  will  be  observed,  moreover,  that  all  these 
effects  are  produced  in  the  course  of  a  few  days,  some  ten  or  twelve  at  most,  while  by 
the  ordinary  mode  of  drying  they  could  hardly  be  accomplished  in  as  many  months.** 
— Mr.  Robertson,  nt  his  Mechanics'  Magazine. 

We  need  scarcely  add  that  the  less  moisture  there  is  left  in  wood,  the  greater  its 
strength— the  more  complete  its  fitness  for  every  purpose  to  which  it  can  be  applied. 

DETONATION.  See  Fulminating,  for  the  mode  of  preparing  detonating  powder 
for  the  percussion  caps  of  fire-arms. 

DEUTOXIDE  literally  means  the  second  oxide,  but  is  usually  employed  to  denote  a 
compound  containing  two  atoms  or  two  prime  equivalents  of  oxygen  to  one  or  more  of 
a  metal.  Thus  we  say  deutoxide  of  copper,  and  deutoxide  of  mercury.  Berzelius  has 
abbreviated  this  expression  by  adopting  the  principles  of  the  French  nomenclature  of 
1787  ;  according  to  which  the  higher  stage  of  oxidizement  is  characterized  by  the  ter- 
mination ic,  and  the  lower  by  ous,  and  he  writes  accordingly  cupric  and  mercuric,  to 
designate  the  deutoxides  of  these  two  metals  ;  cuprous  and  mercurous  to  designate  their 
protoxides.  I  have  adopted  this  nomenclature  in  the  article  DECOMPOsixiox  and  in 
some  other  parts  of  this  Dictionary,  as  being  short  and  suflSciently  precise.       ' 

DEXTRINE  is  a  matter  of  a  gummy  appearance  into  which  the  interior  substance 
of  the  molecules  of  starch  are  converted,  through  the  influence  of  diastase  or  acids  It 
derives  its  names  from  the  circumstance  that  it  turns,  more  than  anv  other  bodv  the 
plane  of  polarization  to  the  right  hand.  It  is  white,  insipid,  without  smell,  transparent, 
m  thin  plates,  friable,  with  a  glassy  fracture  when  well  dried.  It  is  not  altered  by  the 
heat  of  boihng  water,  but  at  280°  F  it  becomes  brown,  and  acquires  the  flavor  of 
toasted  bread.  It  is  not  colored  by  iodine,  like  starch,  it  does  not  form  mucic  acid  with 
the  nitric  as  common  gum  does,  and  it  is  transformed  into  grape  sugar,  when  heated 
along  with  dilute  sulphuric  acid  or  diatase. 

Dextrine  is  much  employed  by  the  French  pastrycooks  and  confectioners:  it  is  a 
good  substitute  for  gum  arable  in  medicine.  For  the  conversion  of  potato  or  other 
starch  into  dextrine,  by  the  action  of  diastase,  see  Brewing. 

This  substance  has  exactly  the  same  chemical  composition  as  starch,  consisting  of  24 
atoms  of  carbon,  20  of  hydrogen,  and  10  of  oxygen  (Dumas) ;  but  it  is  distinguished 


574 


DIAMOND. 


from  starch  by  its  solubility  in  cold  water,  like  gum,  and  not  being  affected  by  iodine^ 
British  gum,  as  it  is  called,  or  roasted  starch,  is  merely  dextrine  somewhat  discolored 
a  substance  apparently  used  for  the  paste  on  the  Queen's  head  post  office  letter  stamps. 
A  process  discovered  by  M.  Payen,  and  patented  in  France  by  M.  Henz6,  for  making 
dextrine,  consists  in  moistening  one  ton  of  dry  starch  with  water  containing  4^  lbs.  of 
strong  nitric  acid.  The  starch  thus  uniformly  wetted,  is  made  up  into  small  bricks  or 
loaves,  and  dried  in  a  stove.  It  is  then  rubbed  down  into  a  coarse  powder,  and  ex- 
posed in  a  stove-room  to  a  stream  of  air  heated  to  about  160°  F.  Being  now  triturated, 
sifted,  and  heated  in  a  stove  to  about  228°  F.,  it  forms  a  perfect  dextrine  of  a  fair  color, 
because  the  acid  acts  as  a  substitute  for  the  higher  heat,  used  in  making  the  British 
gum.  Such  an  article  makes  a  fine  dressing  for  muslin  and  silk  goods,  and  is  muck 
employed  in  French  surgery,  for  making  a  stiff  paste  support  to  the  bandages  of  frao 
tured  liml>8. 

DIAMOND.  Since  this  body  is  merely  a  condensed  form  of  carbon,  it  cannot  in  a 
i>iEmical  classiHcaiion  be  ranked  among  stones;  but  as  it  forms  in  commerce  the  most 
precious  of  the  gems,  it  claims  our  first  attention  in  a  practical  treatise  on  the  arts. 
Diamonds  are  distinguishable  by  a  great  many  peculiar  properties,  very  remarkable  and 
easily  recognised,  both  in  their  rough  state,  and  when  cut  and  polished.  Their  most 
absolute  and  constant  character  is  a  degree  of  hardness  superior  to  Ihatof  everj'  mineral, 
whence  diamonds  scratch  all  other  bodies,  and  are  scratched  by  none.  Their  peculiar 
adamantine  lustre,  not  easy  to  define,  but  readily  distinguishable  by  the  eye  from  that  of 
every  other  gem,  is  their  most  obvious  feature.  Their  specific  gravity  is  3*55.  Whether 
rough  or  polished,  diamonds  acquire  by  friction  positive  electricity,  but  do  not  retain  it 
for  more  than  half  an  hour.  The  natural  form  of  diamonds  is  derivable  from  an  octahe^ 
dron,  and  they  never  present  crjstals  having  one  axis  longer  than  the  other.  Their  struc- 
ture is  very  perceptibly  lamellar,  and  therefore,  notwithstanding  their  great  hardness, 
they  are  brittle  and  give  way  in  the  line  of  their  cleavage,  afiibrding  a  direct  means  of 
arriving  at  their  primitive  form,  the  regular  octahedron. 

The  diamond  possesses  either  single  or  double  refraction,  according  to  its  different  crys- 
talline forms ;  its  refractive  power  on  light  is  far  greater  than  it  ought  to  be  in  the  ratio 
of  its  density  ;  the  index  of  refraction  being  2*44,  whence  Newton  long  ago  supposed  it  tc 
consist  of  inflammable  matter.  Its  various  forms  in  nature  present  a  circumstance  peculiar 
to  this  body ;  its  faces  are  rarely  terminated  by  planes,  like  most  other  native  crystals, 
but  they  are  often  rounded  off,  and  the  edges  between  them  are  curved.  When  these 
secondary  faces  are  attentively  examined  with  a  lens,  we  remark  that  they  are  marked 
with  striae,  sometimes  very  fine  and  almost  imperceptible,  but  at  others  well  defined  ;  and 
that  these  striae  are  parallel  to  the  edges  of  the  octahedron,  and  consequently  to  those  of 
the  plates  that  are  applied  on  the  primitive  faces  of  this  figure. 

Diamonds  are  usually  colorless  and  transparent ;  when  colored,  their  ordinary  tint 
verges  upon  yellow,  or  smoke-yellow,  approaching  sometimes  to  black ish-brown.  Green 
diamonds  are  next  to  yellow  the  most  comifion ;  the  blue  possess  rarely  a  lively  hue,  but 
they  are  much  esteemed  in  Scotland.  The  rose  or  pink  diamonds  are  the  most  valued  of 
the  colored  kind,  and  exceed  sometimes  in  price  the  most  limpid ;  though  generally 
speaking  the  latter  are  the  most  highly  prized. 

The  geological  locality  of  the  diamond  seems  to  be  in  diluvial  gravel,  and  among  con- 
glomerate rocks;  consisting  principally  of  fragments  of  quartz,  or  rolled  pebbles  of  quarta 
mixed  with  ferruginous  sand,  which  compose  sometimes  hard  aggregated  masses.  This 
kind  of  formation  is  called  cascalho  in  Brazil.  Its  accompanying  minerals  are  few  in 
number,  being  merely  black  oxyde  of  iron,  micaceous  iron  ore,  pisiform  iron  ore,  fragment? 
of  slaty  jasper,  several  varieties  of  quartz,  principally  amethyst.  In  Mr.  Heuland's 
splendid  collection  there  was  a  Brazilian  diamond  imbedded  in  brown  iron  ore  ;  another 
in  the  same,  belonging  to  M.  Schuch,  librarian  to  the  Crown  Princess  of  Portugal ;  and 
in  the  cabinet  of  M.  Eschwege  there  is  a  mass  of  brown  iron  ore,  containing  a  diamond 
in  thedrusy  cavity  of  a  green  mineral,  conjectured  to  be  arseniate  of  iron.  From  these 
facts  it  may  be  inferred  with  much  probability  that  the  matrix  or  original  repository  of  th# 
diamond  of  Brazil  is  brown  iron  ore,  which  occurs  in  beds  of  slaty  quartzose  micaceouf 
iron  ore,  or  in  beds  composed  of  iron-glance  and  magnetic  iron  ore,  both  of  which  ar< 
apparently  subordinate  in  that  country  to  primitive  clay  slate. 

The  loose  earth  containing  diamonds  lies  always  a  little  way  beneath  the  surface  of 
the  soil,  towards  tne  lower  outlet  of  broad  valleys,  rather  than  upon  the  ridges  of  the 
adjoining  hills. 

Only  two  places  on  the  earth  can  be  adduced  with  certainty  as  diamond  mines,  oi 
rather  districts;  a  portion  of  the  Indian  peninsula,  and  of  Brazil. 

India  has  been  celebrated  from  the  most  remote  antiquity  as  the  country  of  diamonds. 
Its  principal  mines  are  in  the  kingdoms  of  Golconda  and  Visapour,  extending  from 


J 


^ 


DIAMOND. 


575 


Cape  Comorin  to  Bengal,  at  the  foot  of  a  chain  of  mountains  called  the  Orixa,  which 
appear  to  belong  to  the  trap-rock  formation.  In  all  the  Indian  diamond  soils,  these 
gems  are  so  dispersed,  that  they  are  rarely  found  directly,  even  in  searching  the  richest 
spots,  because  they  are  enveloped  in  an  earthy  crusty  which  must  be  removed  before  they 
can  be  seen.  The  stony  matter  is  therefore  broken  into  pieces,  and  is  then,  as  well  as 
the  looser  earth,  washed  in  basins  scooped  out  on  purpose.  The  gravel  thus  washed  is 
eollected,  spread  oat  on  a  smooth  piece  of  ground,  and  left  to  dry.  The  diamonds  arc 
now  recognised  by  their  sparkling  in  the  sun,  and  are  picked  out  from  the  stones. 

The  diamond  mines  of  Brazil  were  discovered  in  1728,  in  the  district  of  Scrro-do- 
t>rio.  The  ground  in  which  they  are  imbedded  has  the  most  perfect  resemblance  to  that 
of  the  East  Indies,  where  the  diamonds  occur.  It  is  a  solid  or  friable  conglomerate, 
consisting  chiefly  of  a  ferruginous  sand,  which  encloses  fragments  of  various  magnitude 
of  yellow  and  bluish  quartz,  of  schistose  jasper,  and  grains  of  gold  disseminated  with 
oliffist  iron  ore ;  all  mineral  matters  different  from  those  that  constitute  the  neighboring 
mountains;  this  conglomerate,  or  species  of  pudding-stone,  almost  always  superficial, 
occurs  sometimes  at  a  considerable  height  on  the  mountainous  table-land.  The  most 
celebrated  diamond  mine  is  that  of  Mandarga,  on  the  Jisitonhonha,  in  the  district  of 
Serro-do-Frio  to  the  north  of  Rio  Janeiro.  The  river  Ji?itonhonha,  three  times  broader 
than  the  Seine  at  Paris,  and  from  3  to  9  feet  deep,  is  made  nearly  dry,  by  drawing  the 
waters  off  with  sluices  at  a  certain  season  ;  and  the  cascalho  or  diamond-?ravel  is  removed 
from  the  channel  by  various  mechanical  means,  to  be  washed  elsewhere  at  leisure.  This 
cascalho,  the  same  as  the  matrix  of  the  gold  mines,  is  collected  in  the  dry  season,  to  be 
searched  into  during  the  rainy ;  for  which  purpose  it  is  formed  into  little  mounds  of  15 
or  16  tons  weight  each.  The  washing  is  carried  on  beneath  an  oblong  shed,  by  means 
of  a  stream  of  water  admitted  in  determinate  quantities  into  boxes  containing  the  cas- 
calho. A  negro  washer  is  attached  to  each  box;  inspectors  are  placed  at  regular  dis- 
tances on  elevated  stools,  and  whenever  a  negro  has  found  a  diamond,  he  rises  up  and 
exhibits  It.  If  it  weighs  17^  carats,  he  receives  his  liberty.  Many  precautions  are 
taken  to  prevent  the  negroes  from  secreting  the  diamonds.  Each  squad  of  workmen 
consists  of  200  negroes,  with  a  surgeon  and  an  almoner  or  priest. 

The  flat  lands  on  either  side  of  the  river  are  equally  rich  in  diamonds  over  their  whole 
surface,  so  that  it  becomes  very  easy  to  estimate  what  a  piece  of  ground  not  yet  washed 
may  produce. 

It  is  said  that  the  diamonds  surrounded  with  a  greenish  crust  are  of  the  first  water, 
or  are  the  most  limpid  when  cut.     The  diamonds  received  in  the  different  mines  of  the 
district  are  deposited  once  a  month  in  the  treasury  of  Tejuco ;  and  the  amount  of  what  , 
was  thus  delivered  from  1801  to  1806,  may  be  estimated  at  about  18  or  19  thousand  ca- 
rats per  annum. 

On  the  banks  of  the  torrent  called  Rio  Pardo,  there  is  another  mine  of  diamonds. 
The  ground  presents  a  great  many  friable  rocks  of  pudding-stone,  distributed  in  irregu- 
lar strata.  It  is  chiefly  in  the  bed  of  this  stream  that  masses  of  cascalho  occur,  pecu- 
liarly rich  m  diamonds.  They  are  much  esteemed,  particularly  those  of  a  greenish-blue 
color.  The  ores  that  accompany  the  diamond  at  Rio  Pardo  differ  somewhat  from  those 
of  the  washing  grounds  of  Mandanga,  for  they  contain  no  pisiform  iron  ore ;  but  a  great 
many  pebbles  of  slaty  jasper.  This  table  land  seems  to  be  very  high,  probably  not  less 
than  5500  feet  above  the  level  of  the  sea. 

Tocaya,  a  principal  village  of  Minas  Novas,  is  34  leagues  to  the  northeast  of  Tejuco 
in  an  acute  angle  of  the  confluence  of  the  Jigitonhonha  and  the  Rio  Grande.  In  the 
bed  of  the  streamlets  which  fall  westward  into  the  Jigitonhonha,  those  rolled  white 
topazes  are  found  which  are  known  under  the  name  of  minas  novas  with  blue  topazes,and 
aquamarine  beryls.  In  the  same  country  are  found  the  beautiful  cymophanes  or  cnso- 
beryls  so  much  prized  in  Brazil.  And  it  is  from  the  cantons  of  Indaia  and  Abaite  thai 
the  largest  diamonds  of  Brazil  come;  yet  they  have  not  so  pure  a  water  as  those  of  the 
district  of  Serro-do-Frio,  but  incline  a  little  to  the  lemon  yellow. 

Diamonds  are  said  to  come  also  from  the  interior  of  the  island*  of  Borneo,  on  the  banks 
of  the  river  Succadan,  and  from  the  peninsula  of  Malacca. 

It  is  known  that  many  minerals  become  phosphorescent  by  heat,  or  exposure  to  the 
sun's  light.  Diamonds  possess  this  property,  but  all  not  in  equal  decree,  and  certain 
precautions  must  be  observed  to  make  it  manifest.  Diamonds  need  to  be  exposed  to  the 
sunbeam  for  a  certain  time,  in  order  to  become  self-luminous;  or  to  the  blue  rays  of  the 
prismatic  spectrum,  which  augment  still  more  the  faculty  of  shinin?  in  the  dark.  Dia- 
monds susceptible  of  phosphorescence  exhibit  it  either  after  a  heat  not  raised  to  redness, 
or  the  electric  discharge.  They  possess  not  only  a  great  refractive  power  in  the  mean 
ray  of  light,  but  a  high  dispersive  agency,  which  enables  them  to  throw  out  the  most 
varied  and  vivid  colors  in  multiplied  directions. 

Louis  de  Berquem  discovered,  in  1476,  the  art  of  cutting  diamonds  by  rubbing  them 

37 


576 


DIAMOND. 


against  one  another,  and  of  polishing  them  with  their  own  powder.  These  operations 
may  be  abridged  by  two  methods:  1.  by  availing  ourselves  of  the  direction  of  tlie 
laminte  of  the  diamond  to  split  them  in  that  direction,  and  thus  to  produce  several  facets. 
This  process  is  called  cleaving  the  diamond.  Some,  which  appear  to  be  made  crystals, 
resist  this  mechanical  division,  and  are  called  diamonds  of  nature.  2.  by  sawing  the 
diamonds  by  means  of  a  very  delicate  wire,  coated  with  diamond  powder: 

Diamonds  take  precedence  of  every  gem  for  the  purpose  of  dress  and  decoration ;  and 
hence  the  price  attached  to  those  of  a  pure  water  increases  in  so  rapid  a  proportion,  that, 
beyond  a  certain  term,  there  is  no  rule  of  commercial  valuation.  The  lai^est  diamond 
that  is  known  seems  to  be  tliat  of  the  Rajah  of  Mattan,  in  the  East  Indies.  It  was  of  the 
purest  water,  and  weighs  367  carats,  or  at  the  rate  of  4  grains  to  a  earat^  upward  of  8 
ounces  troy.  It  is  shaped  like  an  egg,  with  an  indented  hollow  near  the  smaller  end ; 
it  was  discovered  at  Landak  about  100  years  ago;  and  though  the  possession  of  it 
has  cost  several  wars,  it  remained  in  the  Mattan  family  for  90  years.  A  governor  of 
Batavia,  after  ascertaining  the  qualities  of  the  gem,  wished  to  be  the  purchaser,  and 
oflFered  150,000  dollars  for  it,  besides  two  war  brigs  with  their  guns  and  ammunition, 
together  with  a  certain  number  of  great  guns,  and  a  quantity  of  powder  and  shot.  But 
this  diamond  possessed  such  celebrity  in  India,  being  regard  as  a  talisman  involving 
the  fortunes  of  the  Rajah  and  his  family,  that  he  refused  to  part  with  it  at  any  price. 

The  Mogul  diamond  passed  into  the  possession  of  the  ruling  fatnily  of  Kabul,  as  has 
been  invariably  affirmed  by  the  members  of  that  family,  and  by  the  jewellers  of  Delhi 
and  Kabul.  It  has  been  by  both  parties  identified  with  the  great  diamond,  now  known 
under  the  name  of  the  Koim-Nook^  or  mountain  of  light,  which  was  displayed  by  its 
present  proprietor,  her  Majesty  the  Queen,  at  the  recent  Great  Exhibition.  '  It  is  now 
being  properly  cut  by  skilful  Dutch  artists,  under  the  charge  of  Messrs.  Garrard, 
jewellers  in  London,  in  order  to  bring  out  all  its  lustre,  and  remove  some  superficial 
specks  or  clouds.     The  weight  of  it  has  been  of  old  various  stated. 

The  diamond  possessed,  in  the  time  of  the  traveller  Tavernier,  by  the  emperor  of 
Mogul,  a  kingdom  now  no  more,  weighed  279  carats,  and  was  reckoned  worth  upwards 
of  400,000/.  sterling.  It  was  said  to  have  lost  the  half  of  its  original  weight  in 
the  cutting.  After  these  prodigious  gems,  the  next  are: — 1.  That  of  the  emperor  of 
Russia,  bought  by  the  late  empress  Catharine,  which  weighs  193  carats.  It  is  said  to 
be  of  the  size  of  a  pigeon's  cgz^  and  to  have  been  bought  for  90,000/.,  besides 
an  annuity  to  the  Greek  merchant  of  4000/.  It  is  reported  that  *he  above  diamond 
formed  one  of  the  eyes  of  the  famous  statue  of  Sheringan,  in  the  temple  of  Brama,  and 
that  a  French  grenadier,  who  had  deserted  into  the  Malabar  service,  found  the  means  of 
robbing  the  pagoda  of  this  precious  gem ;  and  escaped  with  it  to  Madras,  where  he 
disposed  of  it  to  a  ship  captain  for  2,000/.,  who  resold  it  to  a  Jew  for  12,000/.  From 
him  it  was  transferred  for  a  large  sum  to  the  Greek  merchant.  2.  That  of  the  emperor 
of  Austria,  which  weighs  139  carats,  and  has  a  slightly  yellowish  hue.  It  has,  however, 
been  valued  at  100,000/.  3.  That  of  the  king  of  France,  called  the  Regent  or  Pitt 
diamond,  remarkable  for  its  form  and  its  perfect  limpidity.  Although  it  weighs  only  136 
carats,  its  fine  qualities  have  caused  it  to  be  valued  at  160,000/.,  though  it  cost  only 
100,000/. 

The  largest  diamond  furnished  by  Brazil,  now  in  possession  of  the  crown  of  Portugal, 
weighs,  according  to  the  highest  estimates,  120  carats.  It  was  found  in  the  streamlet 
of  Abaite,  in  a  clay-slate  district. 

The  diamonds  possessed  of  no  extraordinary  magnitude,  but  of  a  good  form  and  a 
pure  water,  may  be  valued  by  a  certain  standard  rule.  In  a  brilliant,  or  rose-diamond 
of  regular  proportions,  so  much  is  cut  away  that  the  weight  of  the  polished  gem  does 
not  exceed  one  half  the  weight  of  the  diamond  in  the  rough  state ;  whence  the  value  of 
a  cut  diamond  is  esteemed  equal  to  that  of  a  similar  rough  diamond  of  double  weight, 
exclusive  of  the  cost  of  workmanship.  The  weight  and  value  of  diamonds  are  reckoned 
by  carats  of  4  grains  each ;  and  the  comparative  value  of  two  diamonds  of  equal  quality 
but  different  weights,  is  as  the  squares  of  these  weights  respectively.  The  average  price 
of  rough  diamonds  that  are  worth  working  is  about  2/.  for  one  of  a  single  carat ;  but  as 
a  polished  diamond  of  one  carat  must  have  taken  one  of  2  carats,  its  price  in  the  rough 
state  is  double  the  square  of  2/.,  or  8/.  Therefore,  to  estimate  the  value  of  a  wrought 
diamond,  ascertain  its  weight  in  carats,  double  that  weight,  and  multiply  the  square  of 
this  product  by  21. 

Hence,  a  wrought  diamond  of  1  carat  is  worth 

2  — 


3 

4 
5 
6 


£  8 
32 
72 
128 

200 
288 


DIAMOND. 


577 


of  7  carats  is  worth    892 

8  —  612 

9—612 

10  —  800 

Tz:::z^::r  ^^\^----^.  vr7,r..^ojz  KaifntbTrtfVuth^:; 

cuUirXt  wZ^"''•  «"^^/%f,<^.«»"«tive  gems,  but  for  more  useful  purposes,  as  for 
cutting  glass  by  the  glazier,  and  all  kinds  of  hard  stones  by  the  lapidarV. 

vaUons  nndT7V      T  ^}^^%\^''^^^^^  we  possess  some  very  interesting  obser- 
bro  X  t^  /i'f '"^^  Dr  Wollaston.     He  remarks,  that  the  hardest  substances 

Alnnf  r.  a\TK  P"""*  '''•'"^t.  ^^^"^  ^"^«^^'  b"<^  ^^  «ot  cut  it,  and  that  diamonds 

alone  possessed  that  property;  which  he  ascribes  to  the  peculiarity  of  its  crystalirtLn 
in  rounded  faces  and  curvilinear  edges.  For  glass-cutting,  thoseVough  dfamonds  ar^ 
always  selected  which  are  sharply  crystallizedrhence  callld  diamond  sparks  but  ciU 
dmrnonas  are  never  used.  The  inclination  to  be  given  to  a  set  diamond  fncuit'ineeU^ 
IS  comprised  w.th.n  very  narrow  limits;  and  it  ought,  moreoverto  be  moveHn  1^ 
direction  of  one  of  its  angles.  The  curvilinear  edge  adjoining  the  curved  f^es  ente.  n* 
as  a  wedge  into  the  furrow  opened  up  by  itself,  thus  tends  to  sepa^e  the  Srts  of  hf 
glass ;  and  in  order  that  the  crack  which  causes  the  seoaratinn  of  fhlV;?^.  ^  !•  i 

3:is'%fn"'/'^''^'"rt'"r  '^  ""'''  al-st  Ve^r/nd^riaf  o'^thT^fL^^^^^^^ 
wJ.  .   I        r'^K  PT^  ^^^  '^^""'"^  ^y^"  experiment.     If,  by  suitable  cutting  with  the 
wheel,  we  make  the  edge*  of  a  spinel  ruby,  or  corundura-telesie  fsannhire    curvi  np«r 

5elrreL\\"d  \  r  U'thl^^^^^         f""  ""'  T'''^''  as  weira'a^gS^^dfronr^ 

not  seem  to  exceed  the  two-hundredth  of  an  inch^        "  ^"^^""^  penetrates,  does 

^:^l^^^^i:i^:^^^  -  ^-^  choice  of  rough 

the  coat  be  smooth  and  bright,  with  a  liule  tincture  of%Teen1n'jr?f  t  Lv  T  ^ 

and  seldom  proves  bad,  but  iT  there  is  a  mixture  of  ydlow'^kS  gretn  then  b  wareT/u- 
It  IS  a  soft  greasy  stone,  and  will  prove  bad.  ^        '  ^'^^  ^^  ^^' 

li  the  stone  has  a  rough  coal,  so  that  you  can  hardlv  sep  fhrniKrh  -t  o„^  ♦»,         *  u 
white  and  look  as  {(  it  wpre  rou-h  bv  art  \m\  M*>«r  «r  fl^        through  it,  and  the  coat  be 

the  heart  of  the  stone  to  be  white  (and  if  IherrbTanv  black  slt^l^^^^^^^  ""^^  ''^•'"'•^ 
it,  they  may  be  discovered  by  a  true  eye  althou-h  th^Lt  .r  tK^  f'  or  flaws,  or  veins  la 
such  stones  are  generally  goUand  clear.  °  '^^'  °^  '^'  ''^'^"  ^^  '^^  ^^"^^^^  ^^^ 

If  a  diamond  appears  of  a  greenish  bri^^ht  coat  rp«pmKKno.  »     •  *• 

inclining  ,o  black  it  generally  provi  hari,  a^d  sel^,^  bad^  ".JTI  "^  ^l^^"  «i'^ 
known  to  have  been  of  the  Brst  water,  and  seldom  wo^^.h.;,  ,K  °?  t'»™.,'«" 

tinct^eof  ,e.lowsee.os  to  be  .nixed  ^ith  V;orj;CnT  oriu^t^  a'^'e^' Sa"5 

All  diamonds  of  cinnamon  color  are  dubious-  hut  iT  ^r  <.   k..:„i.*         .       •     i 

{:::^rclT::?;u::Lr  tt  sotf  "'•  ?^ 

surface  or  in  their  intPrinr      A  i^T  **'^°^"i^"  grams,  that  sometimes  occur  on  their 

...4erieeUr^:U^et?rt«i:t::r^^^^^^^^^ 


578 


DIAMOND  DUST. 


crystals.     When  this  happens,  the  stone  does  not  readily  cut  and  polish,  and  is  there- 
fore of  inferior  value. 

In  the  cut  and  polished  gem,  the  thickness  must  always  bear  a  certain  proportion  to 
the  breadth.  It  must  not  be  too  thin  nor  thick;  for,  when  too  thin,  it  loses  much  of 
its  fire,  and  appears  not  unlike  glass. 

The  term  carate  is  said  to  be  derived  from  the  name  of  a  bean,  the  produce  of  a  speciee 
of  eri/thina,  a  native  of  the  district  of  Shangallas,  in  Africa,  a  famous  mart  of  gold-dust. 
The  tree  is  called  kuara,  a  word  signifying  sun  in  the  language  of  the  country;  because 
it  bears  flowers  and  fruit  of  a  flame  color.  As  the  dry  seeds  of  this  pod  are  always  of 
nearly  uniform  weight,  the  savages  have  used  them  from  time  immemorial  to  weigh 
gold.  The  beans  were  transported  into  India,  at  an  ancient  period,  and  have  been 
long  employed  there  for  weighing  diamonds.  The  carat  of  tlie  civilized  world  is,  in 
fact,  an  imaginary  weight,  consisting  of  4  nominal  grains,  a  little  lighter  than  4  grains 
troy  {jpoids  de  marc);  it  requires  74  carat  grains  and    l    to  equipoise  72  of  the  other. 

In  valuing  a  cut  diamond,  we  must  reckon  that  one  half  of  its  weight  has  been  lost  in 
the  lapidary's  hands;  whence  its  weight  in  this  state  should  be  doubled  Wfore  we 
calculate  its  price  by  the  general  rule  for  estimating  diamonds.  The  French  multinly 
by  48  the  square  of  this  weight,  and  they  call  the  product  in  francs  he  value  of  "the 
di8.mond.  Thus,  for  example,  a  cut  diamond  of  10  carats  would  be  worth  (10  X  ?)' 
X  48:^19,200  francs,  or  768/.,  allowing  only  25  francs  to  the  pound  sterling. 

The  diamond  mines  of  Braizil  have  brought  to  its  government,  from  the  year  1730 
till  1814,3,023,000  carats;  being  at  the  average  rate  annually  of  36,000  carats,  or  a 
little  more  than  16  lbs.  weight.  They  have  not  been  so  productive  in  the  later 
years  of  that  period;  for,  according  to  Mr.  Mawe,  between  1801  and  1806,  onl> 
115,675  carats  were  obtained,  being  19,279  a  year.  The  actual  expenses  incurred  by 
the  government,  during  this  interval,  was  4,419,700  francs;  and,  deducting  the  pro- 
duction in  gold  from  the  washings  of  the  diamond  gravel,  or  cascalho,  it  is  found  that 
the  rough  diamonds  cost  in  exploration,  per  carat,  38  francs  20  c,  or  nearly  31*. 
British  money.  The  contraband  is  supposed  to  amount  to  one  third  of  the  above 
legitimate  trade.  Brazil  is  almost  the  only  country  where  diamonds  are  mined  at  the 
present  day ;  it  sends  annually  to  Eiurope  from  25  to  30  thousand  carats,  or  from  10  to 
16^  lbs. 

DIAMONDS,  cuffing  of.  Although  the  diamond  is  the  hardest  of  all  known  sub- 
stances, yet  it  may  be  split  by  a  steel  tool,  provided  a  blow  be  applied ;  but  this  requires 
a  perfect  knowledge  of  the  structure,  because  it  will  only  yield  to  such  means  in  certain 
directions.  This  circumstance  prevents  the  workmi-i  from  forming  faceltes  or  planes 
generally,  by  the  process  of  splitting;  he  is  therefore  obliged  to  resort  to  the  process 
of  abrasion,  which  is  technically  called  cutting.  The  process  of  cutting  is  effected  by 
fixing  the  diamond  to  be  cut  on  the  end  of  a  stick,  or  handle,  in  a  small  ball  of 
cement,  that  part  which  is  to  be  reduced  being  left  to  project.  Another  diamond  is 
also  fixed  in  a  similar  manner;  and  the  two  stones  being  rubbed  against  each  other 
with  considerable  force,  they  are  mutually  abraded,  flat  surfaces,  or  facettes,  being 
thereby  produced.  Other  faceltes  are  formed  by  shifting  the  diamonds  into  fresh 
positions  in  the  cement,  and  when  a  sufficient  number  are  produced,  they  are  fit  for 
polishing.  The  stones,  when  cut,  are  fixed  for  this  purpose,  by  imbedding  them  in  soft 
solder,  contained  in  a  small  copper  cup,  the  part,  or  facelle,  to  be  polished,  being  left  to 
protrude. 

A  flat  circular  plate  of  cast-iron  is  then  charged  with  the  powder  produced  during 
the  abrasion  of  the  diamonds ;  and  by  this  means  a  tool  is  formed  which  is  capable  of 
producing  the  exquisite  lustre  so  much  admired  on  a  finely-polished  gem.  Those 
diamonds  that  are  unfit  for  working,  on  account  of  the  imperfection  of  their  lustre  or 
color,  are  sold,  for  various  purposes,  under  the  technical  name  of  Bort.  Stones  of  this 
kind  are  frequently  broken  in  a  steel  mortar,  by  repeated  blows,  until  they  are  reduced 
to  a  fine  powder,  which  is  used  to  charge  metal  plates,  of  various  kinds,  for  the  use  of 
jewellers,  lapidaries,  and  others.  Bort,  in  this  state  of  preparation,  is  incapable  of 
polishing  any  gems ;  but  it  is  used  to  produce  flat  surfaces  on  rubies  and  other  precious 
stones. 

Fine  drills  are  made  of  small  splinters  of  bort,  which  are  used  for  drilling  small  boles 
in  rubies,  and  other  hard  stones,  for  the  use  of  watch-jewellers,  gold  and  silver  wire- 
drawers,  and  others,  who  require  very  fine  holes  drilled  in  such  substances.  These  drills 
are  also  used  to  pierce  holes  in  china,  where  rivets  are  to  be  inserted  ;  also  for  piercing 
holes  in  artificial  enamel  teeth,  or  any  vitreous  substances,  however  hard. 

DIAMOND  DUST.  The  demand  for  diamond  dust  within  a  few  years  has  in- 
creased very  materially,  on  account  of  the  increased  demand  for  all  articles  that  are 
wrought  by  it,  such  as  cameos,  intaglios,  &c.  Recently  there  has  been  a  discovery 
made  of  the  peculiar  power  of  diamond  dust  upon  steel ;  it  gives  tlie  finest  edge  to  all 


i 


Di  AS'IASE.  579 

kinds  of  cutlery,  and  threatens  to  displace  the  hone  of  Hunffarv  It  is  wpTI  Vn^w,,  ,u  * 
ofZ'ZV  ?"T2  (!'-,i-^<^-^  -'-tance  in  naturefthf  dT^t  is  ^  a'd  on  thTteerh 
throrh  ThT  '"^'^  fu^'T^  ""^  ^^•"^  P^^^«"^«  the  instrument  from  making  its  wav 

DIAMOND  MICROSCOPES  were  first  suff^est^^d  bv  r>r    r- «.;.,„        ^  i, 

ferent  crystalline  forms  of  the  diamond  prob»bIvth/Lfj!S  ?"S. ""  ."  ^''■ 

the  only  ones  thai  will  give  a  sinervi.'ion  ft  will  ■  °<"*''«'''»n  »"<)  ihe  o"!)*  are 
grind  iamond  lenses  pwLn>Tbo  rbeca  .sI  wrfiZ?  °?"^ ''%°'^"'"u'''''.  »? 
aberration,  and  because  it  saves  the  trouble  of  grTniine  ofe  shifT.l.*  '""^ 'P^"'^ 

pletin^g  a  double  eon'veJof  ejua,  r^C^U^^ZZO:^-^::^ :: :Z: 
ture  of  ,tj  of  an  ,nch  w,th  distinctness  upon  o,?,'q„e  object^  and  i^  entire  diameter 

ilrration  by  the  interpofiUon  F.  y"a  sil' e  „t,S  tlZZn  "l'^"'  r'""""' 
ture  of  it  with  an  eyeglass,  is  evident     We  thus  bli^  1'  '!'"''"''»'  'ookmg  at  a  pio- 

'  mXi^FR  -- --.^/y  an^t  U^^fral\::;ro7o  Jetr'  '■"-'  ""^'^'"^ 

without  thraid  of  J^vn,'  ^  'i^P'^'  ^"'^  '"  ^'•°"^'^'  entirely  by  the  weaver! 

onlVilft^vt  «  tZs/lSL-rv^arw-hentror  h^  ^^fr:^';^^'^  T^^  ^ 

are  generally  five-leaf  tweehthatls  to  J^^  mounting  ,s  called  diaper.     Diapers 

woof,  and  is^aiseJ  anro^l^ur'e   a  erlven  ^Uh'th'Tfth  "Th""'"^'"  ^'^'^  "^ 
cessively,  formin-  diagonals  at  A^°  ,, nnn  t h«  «i  Ti  u     ■'     ^^'^  '^  "^^'"^  ^'^^^^  sue- 

is  called' 'the  broken  tC     The  lat"^"   s  Ven^^nT  J  notT''  ''  ^  ^i"^^^^'  "^'^^ 
n,anufacture  of  diaper.     The  reason  of  n-pf^r^.i'. if     u  ^'^'^--^^lly'  ^dopted  in  the 

where  ornaments  are^o  be  fLedtrveryoTvrusVhe^h^^^^^^  '"    r'  ^^'"^^^  ^"'^•^^• 
flushing  to  give  the  appearance  of  ohi:nM;«rr    ^'^e  ,^J.«'e  dependmg  upon  reversed 

destroy  much  of  theXrand  Lt  Ha    '«%%    ren?auty"o7'the'f:b''  ^^^'k"?^' 
tweel,  on  the  contrary,  restores  to  the  tweeled  cicnh  a  'real  sin^  laHtv'r  '  ^''*^"'* 

plam,  or  alternately  interwoven  fabrics,  and  at  the  samP  .1  ^^  ""^  appearance  to 

producing  ornaments  by  reversin^^  the  flushing      Th^^f    T  .  r-^T""?  ^^^  ^^^^''^^  °^ 
will  be  found  describeJunder  Textile  Fabr"S.  "^''''  ^'"^'  "^  '""""''^^^  '^^«'* 

DIASTASE.     This  curious  substance  extra*«tpH  Kv  nrof».  e  ^    .       , 

cipitated  from  that  infusion  bv  alcoh^ras  isTe.cKbL  u^^^^  ""'^'^  "^"^'v*"^  ^'^' 

made  the  subject  of  new  researches  by  m!  Guer7n  Varrv    Vh?'^^''^^^^^  **-" 

from  his  interesting  experiments  are  the  foIlowiJicr  1        ^'     ^^  conclusions  deducible 

tato  s^arcVot  ^f  t^^  o?^;:,^^  iot'^xSelri?  T'?  ^"  ^''^  '''  '-''  ^'  ^ 
in  the  course  of  63  days   under 'a  telTeVre^Ta^^l^g^'l?^^^^^^^  -^«^-- 

paft-s  Tf^stai'rrb'u  :r  r:  erp:ir.!;\:ra:h^-^  ^^  '^-  -r  {-  ^^^^^  ^^  ^^- 

which  bursts  them  into' a  pa  L^  l^fol WsXt  d^^l"'"^  "^^  '^^'  ""^'^^  ^«' ^«'«' 
germination,  towards  eliminating  the  te^^mPnu  of  !h  .^''k  ""  P*'^  '?  ^^^  P'«"^^«  ^^ 
rior  portion 'into  sugar,  and  a  gumL^^^lttr^sLlfe^  ^ptnU.  ^""'"°^"^  '''  ^^'" 


580 


DIES  FOR  STAMPING. 


DIES  FOR  STAMPING. 


581 


8.  Diastase  liquefies  and  saccharifies  the  paste  of  starch  without  absorption  or  disen- 
gagement of  gas ;  a  reaction  which  takes  place  equally  in  vacuo  as  in  the  open  air. 

4.  100  parts  of  starch  made  into  a  paste  with  39  times  their  weight  of  water,  mixed 
with  6"13  parts  of  diastase  dissolved  in  40  parts  of  water,  and  kept  for  an  hour  between 
140°  and  149^  Fahr.,  afforded  86*91  parts  of  sugar. . 

5.  A  paste  containing  100  parts  of  starch,  and  1393  parts  of  water,  put  in  contact 
with  12-25  parts  of  diastase  dissolved  in  367  parts  of  cold  water,  having  been  main- 
tained at  68°  Fahr.  during  24  hours,  produced  77*64  parts  of  sugar. 

6.  The  preceding  experiment,  repeated  at  the  temperature  of  melting  ice,  afforded  at 
the  end  of  2  hours,  11*82  parts  of  sugar. 

7.  T-he  most  favorable  proportions  and  circumstances  for  the  production  of  a  great 
quantity  of  sugar,  are  a  slight  excess  of  diastase  or  barley  malt  (at  least  25  per  cent, 
of  the  latter),  about  50  parts  of  water  to  one  of  starch,  and  a  temperature  between  140° 
and  149°  Fahr.  It  is  of  the  greatest  consequence  for  the  saccharification  to  take 
place  as  speedily  as  possible,  so  that  the  sugar  produced  may  not  be  left  in  contact  with 
much  gummy  matter  {dextrine),  in  which  case  the  diastase  will  not  convert  the  latter 
into  sugar.  In  fact,  the  liquefaction  and  saccharification  should  proceed  simultane- 
ously. 

8.  The  sugar  of  starch  prepared  either  with  diastase,  or  sulphuric  acid,  crystallizes 
in  cauliflowers,  or  in  prisms  with  rhomboidal  facets.  It  has  the  same  composition  as 
sugar  of  grapes. 

9.  Diastase  even  in  excess  does  not  saccharify  the  gummy  matter  dissolved  in  the 
water  along  with  the  starch-sugar,  but  when  the  gum  is  insulated,  it  is  convertible 
almost  entirely  into  sugar. 

10.  Gum  arable,  cane  sugar,  and  beer  yeast,  suffer  no  change  from  diastase. 

11.  A  watery  solution  of  diastase  readily  decomposes  on  keeping,  either  in  contact 
or  out  of  contact  of  air. 

12.  When  starch-sugar,  whether  obtained  by  means  of  diastase  or  sulphuric  acid, 
is  submitted  to  the  spirituous  fermentation,  the  sum  of  the  weights  of  the  alcoljol,  car- 
bonic acid,  and  water  of  crystallization  of  the  sugar,  is  less  than  the  weight  of  the 
sugar  by  about  3|  per  cent  This  difference  proceeds  in  a  great  mensure  from  the  form- 
ation of  some  acetic  acid,  lactic  acid,  volatile  oil,  and  probably  aome  other  unknown 
products  in  the  act  of  fermentation. 

DIDYM.  A  new  metal,  found  in  oxide  of  cerium,  and  so  called  as  being  associated 
in  that  ore  as  a  ttoin  brother  of  lanthanum. 

DIES  FOR  STAMPING.  (Coins,  Fr. ;  Munzstampeln,  Germ.)  The  fii-st  circum- 
stance that  claims  particular  attention  in  the  manufacture  of  dies,  is  the  selection  of  the 
best  kind  of  steel  for  the  purpose,  and  this  must  in  some  measure  be  left  to  the  expe- 
rience of  the  die-former,  who,  if  well  skilled  in  his  art,  will  be  able  to  form  a  tolerably 
correct  judgment  of  the  fitness  of  the  metal  for  the  purpose,  by  the  manner  in  which  it 
works  upon  the  anvil.  It  should  be  rather  fine-grained  than  otherwise,  and  above  all 
things  perfectly  even  and  uniform  in  its  texture,  and  free  from  spots  and  patches  finer  or 
coarser  than  the  general  mass.  But  the  very  fine  and  uniform  steel  with  a  silky  frac- 
ture, which  is  so  much  esteemed  for  some  of  the  purposes  of  cutlery,  is  unfit  for  our 
present  purpose,  from  the  extreme  facility  with  which  it  acquires  great  hardness  by  pres- 
sure, and  its  liability  to  cracks  and  flaws.  The  very  coarse-grained  or  highly  crystalline 
steel  is  also  equally  objectionable ;  it  acquires  fissures  under  the  die-press,  and  seldom 
admits  of  being  equally  and  properly  hardened.  The  object,  therefore,  is  to  select  a  steel 
of  a  medium  quality  as  to  fineness  of  texture,  not  easily  acted  upon  by  dilute  sulphuric 
acid,  and  exhibiting  a  uniform  texture  when  its  surface  is  washed  over  with  a  little 
aqua-fortis,  by  which  its  freedom  from  pins  of  iron,  and  other  irregularities  of  composi- 
tion, is  sufficiently  indicated. 

The  best  kind  of  steel  being  thus  selected,  and  properly  forged  at  a  high  heat  into 
the  rough  die,  it  is  softened  by  very  careful  annealing,  and  in  that  state,  having  been 
smoothed  externally,  and  brought  to  a  table  in  the  turning  lathe,  it  is  delivered  to  the 
engraver. 

The  process  of  annealing  the  die  consists  in  healing  it  to  a  bright  cherry  red,  and  suf- 
fering it  to  cool  gradually,  which  is  best  eflected  by  bedding  it  in  a  crucible  or  iron  pot 
of  coarsely-powdered  charcoal,  that  of  animal  substances  bemg  generally  preferred.  In 
this  operation  it  is  sometimes  supposed  that  the  die,  or  at  least  its  superficial  parts,  be- 
comes super-carbonized,  or  highly-converted  steel,  as  it  is  sometimes  called ;  but  expe- 
rience does  not  justify  such  an  opinion,  and  I  believe  the  composition  of  the  die  is 
scarcely,  certainly  not  materially,  affected  by  the  process,  for  it  does  not  remain  long 
enough  in  the  fire  for  the  purpose. 

The  engraver  usually  commences  his  labors  by  working  out  the  device  with  small 
steel  tools,  in  intaglio ;  he  rarely  begins  in  relief  (though  this  is  sometimes  done)  ;  and 
having  ultimately  completed  his  design,  and  satisfied  himself  of  its  general  effect  and 


correctness,  by  impressions  in  clay,  and  dabs,  or  casts  in  type  metal,  the  die  is  ready  for 
the  important  operation  of  hardening,  which,  from  various  causes,  a  few  of  which  I 
shall  enumerate,  is  a  process  of  much  risk  and  diflliculty ;  for  should  any  accident  now 
occur,  the  labor  of  many  months  may  be  seriously  injured,  or  even  rendered  quite 
useless. 

The  process  of  hardening  soft  steel  is  in  itself  very  simple,  though  not  very  easily 
explained  upon  mechanical  or  chemical  principles.     We  know  by  experience  that  it 
is  a  property  of  this  highly  valuable  substance  to  become  excessively  hard,  if  heated 
and  suddenly  cooled  ;  if,  therefore,  we  heat  a  bar  of  soft  malleable  and  ductile  steel  red 
hot,  and  then  suddenly  quench  it  in  a  large  quantity  of  cold  water,  it  not  only  becomes 
hard,  but  fragile  and  brittle.     But  as  a  die  is  a  mass  of  steel  of  considerable  dimen- 
sions, this  hardening  is  an  operation  attended  by  many  and  peculiar  diflBculties,  more 
especially  as  we  have  at  the  same  time  to  attend  to  the  careful   preservation  of  the 
engraving.    This  is  effected  by  covering  the  engraved  face  of  the  die  with  a  protecting 
face,   composed  of  fixed   oil  of  any  kind,  thickened  with   powdered   charcoal :    some 
persons  add  pipe-clay,  others  use  a  pulp  of  garlic,  but  pure  lamp-black  and  linseed  oi. 
answer  the  purpose  perfectly.    This  is  thinly  spread  upon  the  work  of  the  die,  which, 
if  requisite,  may  be  further  defended  by  an  iron  ring ;  the  die  is  then  placed  with  its 
face  downwards  in  a  crucible,  and  completely  surrounded  by  powdered  charcoal.     It  u 
heated  to  a  suitable  temperature,  that  is,  about  cherry  red,  and  in  that  state  is  taken  out 
with  proper  tongs,  and  plunged  into  a  body  of  cold  water,  of  such  magnitude  as  not 
to  become  materially  increased  in  temiwr  tture ;  here  it  is  rapidly  moved  about,  until  all 
noise  ceases,  and  then  leH  in  the  water  till  quite  cool.    In  this  process  it  should  produce 
a  bubbhng  and  hissmg  noise;  if  it  pipes  and  sings,  we  may  generally  apprehend  a  crack 
or  fissure. 

No  process  has  been  found  to  answer  better  than  the  above  simple  and  common  mode 
of  hardening  dies,  though  others  have  had  repeated  and  fair  trials.  It  has  been  proposed 
to  keep  up  currents  and  eddies  of  cold  water  in  the  hardening  cistern,  by  means  of 
dehvery.pipes,  commg  from  a  height ;  and  to  subject  the  hot  die,  with  its  face  upper- 
most,  to  a  sudden  and  copious  current  of  water,  let  upon  it  from  a  large  pipe,  supplied 
from  a  high  reservoir ;  but  these  means  have  not  in  any  way  proved  Ejore  successfui, 
either  m  saving  the  die  or  in  giving  it  any  good  qualities.  It  will  be  recollected,  from 
the  form  of  the  die,  that  it  is  necessarily  only,  as  it  were,  case-hardened ;  the  hardest 
strata  being  outside,  and  the  sofYer  ones  within,  which  envelop  a  core,  something  in 
the  manner  of  the  successive  coats  of  an  onion ;  an  arrangement  which  we  sometimes 
have  an  opportunity  of  seeing  displayed  in  dies  which  have  been  smashed  by  a  violent 
blow. 

The  hardening  having  been  effected,  and  the  die  being  for  the  time  safe,  ^ome  fur- 
ther steps  may  be  taken  for  its  protection ;  one  of  these  consists  in  a  ^ery  mild  kind  of 
tempering  produced  by  putting  it  into  water,  gradually  raised  to  tiie  boiling  point, 
till  heated  throughout,  and  thei  suffering  it  gradually  to  cool.  This  operation  rendera 
the  die  less  apt  to  crack  in  very  cold  weather.  A  great  safeguard  is  also  obtained  by 
thrusting  the  cold  die  into  a  red-hot  iron  ring,  which  just  fits  it  in  that  state,  and  which, 
by  contracting  as  it  cools,  keeps  its  parts  together  under  considerable  pressure,  pre! 
venting  the  spreading  of  external  cracks  and  fissures,  and  oflen  enabling  us  to  employ  a 
split  or  die  for  obtaining  punches,  which  would  break  to  pieces  without  the  protecting 

If  the  die  has  been  successfully  hardened,  and  the  protecting  paste  has  done  its  duty, 
by  preserving  the  face  from  all  injury  and  oxydizement,  or  burning,  as  it  is  usually 
called.  It   IS  now  to   be  cleaned   and   polished,  and  in  this  state   constitutes  what  is 
technically  called  a  matrix;  it  may,  of  course,  be  used  as  a  multiplier  of  medals,  coins, 
or  impressions,  but  it  is  not  generally  thus  employed,  for  fear  of  accidents  happening 
to  It  in  the  coming  press,  and  because  the  artist  has  seldom  perfected  his  work  upon 
It  m  this  state.     It  is,  therefore,  resorted  to  for  the  purpose  of  finishing  a  punch,  or 
steel  impression  for  relief.     For  this  purpose  a  proper  block  of  steel  is  selected,  of 
the  same  quality,  and  jyith  the  same  precautions  as  before,  and  being  carefully  annealed, 
or  softened,  is  turned  like  the  matrix,  perfectly  true  and  flat  at  the  bottom,  and  obtusei; 
conical   at  top.     In   this   state,  its   conical    surface   is  carefully  compressed   by  pow- 
erful and  proper  machinery  upon  the  matrix,  which,  being  very  hard,  soon  allows  it  to 
receive  the  commencement  of  an  impression;  but  in  thus  receiving  the  impression,  it 
becomes  itself  so  hard  by  condensation  of  texture  as  to  require,  during  the  o^ration,  to 
be  repeatedly  annealed,  or  softened ;  otherwise  it  would  split  into  small  superficial  fis- 
Wres,  or  would  injure  the  matrix ;  much  practical  skill  is  therefore  required  in  taking 
this  impression,  and  the  punch,  at  each  annealing,  must  be  carefully  protected,  so  that 
the  work  may  not  be  injured.  j  y  t 

Thus,  afler  repeated  blows  in  the  die-press,  and  frequent  annealing,  the  impressio* 


582 


DIGESTER. 


from  the  matrix  is  at  length  perfected,  or  brought  completely  up,  and  having  been 
retouched  by  the  engraver,  is  turned,  hardened,  and  collared,  like  the  matrix,  of  which 
It  IS  now  a  complete  impression  in  relief,  and,  as  we  have  before  said,  is  called  a 
punch. 

This  punch  becomes  an  inexhaustible  parent  of  dies,  without  further  reference  to  the 
original  matrix ;  for  now  by  impressing  upon  it  plusfs  of  soft  steel,  and  by  pursuing  with 
them  an  exactly  similar  operation  to  that  by  which  the  punch  itself  was  obtained,  we 
procure  impressions  from  it  to  any  amount,  which  of  course  are  fac-similes  of  the  matrix, 
and  these  dies  being  turned,  hardened,  polished,  and,  if  necessary,  tempered,  are  employed 
for  the  purposes  of  coinage. 

The  distinction  between  striking  medals  and  common  coin  is  very  essential,  and  the 
work  upon  the  dies  is  accordingly  adjusted  to  each.  Medals  are  usually  in  very  high 
relief,  and  the  effect  is  produced  by  a  succession  of  blows;  and  as  the  metal  in  which 
they  are  struck,  be  it  gold,  silver,  or  copper,  acquires  considerable  hardness  at  each 
stroke  of  the  press,  they  are  repeatedly  annealed  during  the  process  of  bringing  them  up. 
in  a  beautiful  medal,  which  Mr.  Wyon  some  time  since  completed  for  the  Royal  Navy 
College  the  obverse  represents  a  head  of  the  King,  in  very  bold  relief;  it  required 
thirty  blows  of  a  very  powerful  press  to  complete  the  impression,  and  it  was  necessary 
to  anneal  each  medal  afler  every  third  blow,  so  that  they  went  ten  times  into  the  fire 
*or  that  purpose.  In  striking  a  coin  or  medal,  the  lateral  spread  of  the  metal,  which 
Otherwise  would  ooze  out  as  it  were  from  between  the  dies,  is  prevented  by  the  applica- 
tion or  a  steel  collar,  accurately  turned  to  the  dimensions  of  the  dies,  and' which, 
wnen  lelt  plain,  gives  to  the  edge  of  the  piece  a  finished  and  polished  appearance;  it  is 
•ometimes  grooved,  or  milled,  or  otherwise  ornamented,  and  occasionally  lettered,  im 
which  case  it  is  made  in  three  separate  and  moveable  pieces,  confined  by  a  rin?,  into 
which  they  are  most  accurately  fitted,  and  so  adjusted  that  the  metal  may  be  forced  intc 
the  letters  by  its  lateral  spread,  at  the  same  time  that  the  coin  receives  the  blow  of  the 
screw-press. 

Coins  are  generally  completed  by  one  blow  of  the  coinins-press.  These  presses  arc 
worked  in  the  Royal  Mint  by  machinery,  so  contrived  that  they  shall  strike,  upon  an 
average,  sixty  blows  in  a  minute;  the  blank  piece,  previously  properly  prepared  and  an- 
nealed, being  placed  between  the  dies  by  part  of  the  sa-ne  mechanism. 

The  number  of  pieces  which  may  be  struck  by  a  sinele  die  of  good  steel,  properly 
hardened  and  duly  tempered,  not  unfrequently  amounts  at  the  Mint  to  between  three  and 
four  hundred  thousand,  but  the  average  consumption  of  dies  is  of  course  much  greater 
owing  to  the  variable  qualities  of  steel,  and  to  the  casualties  to  which  the  dies  are 
liable :  thus,  the  upper  and  lower  die  are  often  violently  struck  together,  owin<'  to  an 
error  m  the  layer-on,  or  in  that  part  of  the  machinery  which  ought  to  put  the  bla'nk  into 
Us  place,  but  which  now  and  then  fails  so  to  do.  This  accident  very  commonly  arises 
from  the  boy  who  supermtends  the  press  neglecting  to  feed  the  hopper  of  the  layer-on 
with  blank  pieces  If  a  die  is  too  hard,  it  is  apt  to  break  or  split,  and  is  especially  sub- 
jeet  to  fissures,  which  run  from  letter  to  letter  upon  the  edse.  If  too  soft,  it  swells,  and 
the  collar  will  not  rise  and  fall  upon  it,  or  it  sinks  in  the  centre,  and  the  work  becomes 
distorted  and  faulty.  He,  therefore,  who  supplies  the  dies  for  an  extensive  coinage  has 
many  accidents  and  difliculties  to  encounter.  There  are  eieht  presses  at  the  Mint  fre- 
quently at  work  for  ten  hours  each  day,  and  the  destruction  of  eight  pair  of  dies  per  day 
(one  pair  for  each  press)  may  be  considered  a  fair  average  result,  though  they  much  more 
frequently  fall  short  of,  than  exceed  this  proportion.  It  must  be  remembered  that  each 
press  produces  3600  pieces  per  hour,  but,  making  allowance  for  occasional  stoppat'es  we 
may  reckon  the  daily  produce  of  each  press  at  30,000  pieces;  the  eight  pressesl  there- 
fore,  will  furnish  a  diurnal  average  of  240,000  pieces. 

DIGESTER  is  the  name  of  a  strong  kettle  or  pot  of  small  dimensions,  made  very 
strong,  and  mounted  with  a  safety  valve  in  its  top.  Papin,  the  contriver  of  this  appa- 
ratus, used  It  for  subjecting  bones,  cartilages,  &c.  to  the  solvent  action  of  high-pressure 
steam,  or  highly  heated  water,  whereby  he  proposed  to  facilitate  their  digestion  in 
the  stomach.  This  contrivance  is  the  origin  of  the  French  cookery  pans,  called 
uuloclaves,  because  the  lid  is  self-keyed,  or  becomes  steam-tight  by  turning  it  round 
nnder  clamps  or  ears  at  the  sides,  having  been  previously  ground  with  emery  to  fit  the 
edge  of  the  pot  exactly.  In  some  autoclaves  the  lid  is  merely  laid  on  with  a  fillet  of 
Unen  as  a  lute,  and  then  secured  m  its  place  by  means  of  a  screw  bearing  down  upon  its 
fentre  from  an  arched  bar  above.  The  safety  valve  is  loaded  either  by  a  weight  placed 
rertically  upon  it,  or  by  a  lever  of  the  second  kind  pressing  near  its  fulcrum,  and 
acted  upon  by  a  weight  which  may  be  made  to  bear  upon  any  point  of  its  graduated 
arm. 

^   Chevreul  has  made  a  useful  application  of  the  digester  to  vegetable  analysis.    His 
instrument  consists  of  a  strong  copper  cylinder,  into  which  enters    a  tight  cylinder  of 


DISTILLATION. 


583 


silver  having  its  «dge  turned  over  at  right  angles  to  the  axis  of  the  cylinder,  so  as  to 
form  the  rim  of  the  digester.  A  segment  of  a  copper  sphere,  also  lined  with  silver 
fitops  the  aperture  of  the  silver  cylinder,  being  applied  closely  to  ita  rim.  It  has  a 
conical  valve  pressed  with  a  spiral  spring,  of  any  desired  force,  estimated  by  a  steelyard, 
ihis  spring  is  enclosed  within  a  brass  box  perforated  with  four  holes;  which  mav  be 
screwed  into  a  tapped  orifice  in  the  top  of  the  digester.  A  tube  screwed  into  another 
hole  serves  to  conduct  away  the  condensable  vapors  at  pleasure  into  a  Woulfe's 
apparntua  ^ 

DIMITY  is  a  kind  of  cotton  cloth  originally  imported  from  India,  and  now  manu- 
factured in  great  quantities  in  various  parts  of  Britain,  especially  in  Lancashire.  Dr 
Johnson  calls  It  dimmity,  and  describes  it  as  a  kind  of  fustian.  The  distinction  between 
fustian  and  dimity  seems  to  be,  that  the  former  designates  a  common  tweeled  cotton 
cloth  of  a  stout  fabric,  which  receives  no  ornament  in  the  loom,  but  is  most  frequently 
dyed  after  being  woven.  Dimity  is  also  a  stout  cotton  cloth,  but  not  usually  of  so  thick 
a  texture;  and  is  ornamented  in  the  loom,  either  with  raised  stripes  or  fancy  fiirures. 
18  seldom  dyed,  but  usually  worn  white,  as  for  bed  and  bed-room  furni tine.  The 
striped  dimities  are  the  most  common,  they  require  less  labor  in  weaving  than  the 
others;  and  the  mounting  of  the  loom  being  more  simple,  and  consequently  less  expen- 
sive they  can  be  sold  at  much  lower  rates.  See  Textile  Fabrics,  for  particular  details 
of  the  plan  of  mounting  them.  ^  v.«.»»o 

DISINFECTION  OF  CLOTHING,  (JW.  Davison  arul  SymingtorCs  patent  proces A 
—The  absorption  of  noxious  effluvia  by  clothes  or  soft  and  porous  articles  of  inerchan- 
^is'sub'ecr''  ^•^cognised  as  a  fact  by  men  who  have  directed  special  attention  to 

The  use  of  the  various  liquid  disinfectants,  which  have  of  late  been  proposed,  is  not 
applicable  to  articles  of  clothing;  and  the  common  practice  of  baking  clothes  in  ovens 
18  liable  to  lead  to  their  destruction,  owing  to  the  impossibility  of  regulating  the  tem- 
perature to  which  It  18  necessary  to  expose  them.     The  only  plan  which  combines 
economy  with  certainty  of  disinfection,  is  that  which  has  been  patented  by  Messrs. 
Davison  and  Synriington,  and  which  is  now  extensively  employed  in  various  manu- 
factures.    Ihi8  plan  consists  in  exposing  the  articles  of  clothing  in  a  large  chamber  to 
rapid  currents  of  air  heated  to  a  temperature  insufficient  to  iniure  them  i  e  varvin^ 
from  20po  to  250O.     We  have  had  an 'opportunity  of  witnessing"' this  proT;^  a"  ap^lle! 
to  certain  branches  of  manufacture,  and  the  results  were  of  the  most  satisfactory  kind. 
In  the  case  of  infected  clothing.  ,t  is  obvious,  that  while  a  high  temperature  tJnds  to 
destroy  the  animal  poisons,  a  rapid  current  of  air,  constantly  passing  through  the  chamber 
tends  to  carry  them  off.     The  temperature  of  the  current  of  air  can  be  so^egulatedthai 
common  albumen  is  speedily  dried  into  a  yellow  transparent  solid,  without  loagulation. 
or  if  necessary,  the  heat  may  be  increased  from  400°  to  500^,  according  to  the  nature 
of  the  articles  which  are  exposed      Dr.  Copland  has  already  directed  the  attention  of 
the  profession  to  this  process,  and  observes  that,  "the  great  advantage  of  this  method 
IS  Its  easy  applicability  to  all  kinds,  and  to  any  number  of  objects  and  articles  without 
njury  to  their  textures  or  fabrics."     From  an  inspection  of  one  of  these  chambers,  when 
tl.e  temperature  of  the  current  of  air  was  116^,  we  can  state  that  the  process  of  Messrs. 
Davison  and  Symington  for  the  drying  and  disinfecting  of  the  clothing  of  cholera  and 
fever  patients,  will  l>e  far  more  efficacious  than  the  common  plan  of  washino-  „„d  bakin.. 
In  our  opinion,  an  apparatus  of  this  kind,  fitted  up  in  large  hospital^  intirmariet 
prisons  and  workhouses,  as  well  as  all  quarantine  stations,  would  be  admirably  adapted 
to  prevent  the  diffusion  of  infectious  diseases.  ^  «u«ptea 

DISTILLATION  (Eng.  and  Fr. ;  Branntuevnhrennerei,  Germ.)  means,  in  the  commer- 
cial  languaffe  of  this  countrj',  the  manufacture  of  intoxicating  spirits;  under  which  we 
comprehended  the  four  processes,  o(  mashing  the  vegetable  materials,  roo//ng  the  wori^ 
exciting  the  vinous  /crm^/a/ton  and  separating  by  a  peculiar  vessel,  called  a  stilL  Xhi 
alcohol  combined  with  more  or  less  water.     This  art  of  evoking  the  fiery  demon  of 
drunkenness  from  his  attempered  state  in  wine  and  beer,  was  unknown  to  the  ancient 
Greeks  and  Ronrians.     It  seems  to  have  been  invented  by  ihe  barbarianTof  the  north  rf 
Europe,  as  a  solace  to  their  cold  and  humid  clime;  and  was  first  made  known  to  lh* 
sou  hern  nations  m  the  writmgs  of  Arnoldus  de  Villa  Nova,  and  his  pupil,  Raymond 
Lully  of  Majorca   who  declares  this  admirable  essence  of  wine  to  be  an  emanat  on  of 
the  Divmity,  an  element  newly  revealed  to  man,  but  hid  from  antiquity,  because  the  h  ,, 
man  race  were  then  too  young  to  need  this  beverage,  destined  to  ?eviv;  Te  energii  of 
modern  decrepitude.     He  further  imagined  that  the  discovery  of  this  aqua  rii<B,  as  it  wm 
called,  indicated  the  approaching  consummation  of  all  things— the  end  of  this  world 
However  much  he  erred  as  to  the  value  of  this  remarkable  essence,  he  truly  predicted  its 
n^t  influence  upon  humanity,  since  to  both  civilized  and  savage  nations  it  has  realize? 
ireater  ills  than  were  threatened  m  the  fabled  box  of  Pandora. 


: 


584 


DISTILLATION. 


DISTILLATION. 


585 


I  shall  consider  in  this  place  the  first  three  of  these  subjects,  reserving  for  the  article 
Still  an  account  of  the  construction  and  use  of  that  apparatus. 

Whiskey,  from  the  Irish  word  Usquebaugh,  is  the  British  name  of  the  spirituous 
liquor  manufactured  by  onr  distillers,  and  corresponds  to  the  Eau  de  vie  of  the  French 
and  the  Branntwein  of  the  Germans.  It  is  generated  by  that  intestine  change  which 
grape  juice  and  other  glutino-saccharine  liquids  spontaneously  undergo  when  exposed  to 
the  atmosphere  at  common  temperatures ;  the  theory  of  which  will  be  expounded  under 
the  article  Fermentation.  The  production  of  whiskey  depends  upon  the  simple  fact, 
that  when  any  vmous  fluid  is  boiled,  the  alcohol,  being  very  volatile,  evaporates  first,  and 
may  thereby  be  separated  from  the  aqueous  vecetable  infusion  in  which  it  took  its  birth. 
Susar  IS  the  only  substance  which  can  be  transformed  into  alcohol.  Whatsoever  fruits, 
seeds,  or  roots  afford  juices  or  extracts  capable  of  conversion  into  vinous  liquor,  either 
eontam  sugar  ready  formed,  or  starch  susceptible  of  acquiring  the  saccharine  state  by 
proper  treatment.  In  common  language,  the  intoxicating  liquoV  obtained  from  the  swe«» 
juices  of  fruits  is  called  wine;  and  that  from  the  infusions  of  farinaceous  seeds,  beer; 
though  there  is  no  real  diflerence  between  them  in  chemical  constitution.  A  similar 
beverage,  though  probably  less  palatable,  is  procurable  from  the  juices  and  infusions  of 
many  roots,  by  the  process  of  fermentation.  Wine,  cider,  beer,  and  fermented  wash  of 
every  kind,  when  distilled,  yields  an  identical  intoxicating  spirit,  which  differs  in  these 
dillerent  cases  merely  in  flavor,  in  consequence  of  the  presence  of  a  minute  quantity  of 
volatile  oils  of  different  odors. 

L  The  juices  of  sweet  fruits  contain  a  glutinous  ingredient  which  acts  as  a  ferment  in 
causing  their  spontaneous  change  into  a  vinous  condition ;  but  the  infusions  of  seeds, 
even  m  their  germinated  or  malted  state,  require  the  addition  of  a  glutinous  substance 
called  yeast,  to  excite  the  best  fermentation.  In  the  fabrication  of  wine  or  beer  for  drink- 
ing, the  fermentative  action  should  be  arrested  before  all  the  fruity  saccharum  is 
decomposed;  nor  should  it  on  any  account  be  suffered  to  pass  into  the  acetous  stage ; 
whereas  for  making  distillery  wash,  that  action  should  be  promoted  as  long  as  the 
proportion  of  alcohol  is  increased,  because  the  formation  of  a  little  acetic  acid  is  not 
injurious  to  the  quality  of  the  distilled  spirit,  but  rather  improves  its  flavor  by  the 
addition  of  acetic  ether,  while  all  the  undecomposed  sugar  is  lost.  Disiillers  operate 
upon  the  saccharine  matter  from  corn  of  various  kinds  in  two  methods ;  in  the  first  they 
draw  off  a  pure  watery  extract  from  the  grain,  and  subject  this  species  of  wort  to  fer- 
mentation;  m  the  second  they  ferment  and  distil  the  infused  mass  of  grains.  The 
former  is  the  practice  of  the  distillers  in  the  United  Kingdom,  and  is  preferable  on 
many  accounts;  the  latter,  which  is  adopted  in  Germany,  Holland,  and  the  north 
01  Europe,  is  less  economical,  more  uncertain  in  the  product,  and  aflbrds  a  cruder 
spirit,  in  consequence  of  the  fetid  volatile  oil  evolved  from  the  husks  in  the 
still.  The  substances  employed  by  the  distillers  may  be  distributed  into  the  following 
classes  : —  ° 

1.  Saccharine  juices.  At  the  head  of  these  stands  cane-juice,  which  fresh  from  the 
mill  contains  from  12  to  Ifi  per  cent,  of  raw  su?ar,  and  like  the  must  of  the  grape 
enters  into  the  vinous  fermentation  without  the  addition  of  yeast,  affording  the  specief 
of  spirit  called  Rum,  which  is  possessed  of  a  peculiar  aroma  derived  from"  an  essential 
oil  m  the  cane.  An  inferior  sort  of  rum  is  fabricated  from  molasses,  mixed  with  the 
skunmmgs  and  washings  of  the  sugar  pans.  When  molasses  or  treacle  is  diluted  with 
twenty  times  its  weight  of  warm  water,  and  when  the  mixture  has  cooled  to  78°  F.,  if 
one  twelfth  of  Its  weight  of  yeast  be  added,  fermentation  will  speedily  ensue,  and  an 
ardent  spirit  will  be  generated,  which  when  distilled  has  none  of  the  aroma  of  rum; 
proving  this  to  reside  in  the  immediate  juice  or  substance  of  the  cane,  and  to  be  di'j'i- 
pated  at  the  high  temperature  emjiloyed  in  the  production  of  molasses.  Though  the 
cane  juice  will  spontaneously  undergo  the  vinous  fermentation,  it  does  so  more  slowly 
and  irregularly  than  the  routine  of  business  requires,  and  therefore  is  quickened  by  the 
addition  of  the  lees  of  a  preceding  distillation.  So  sensible  are  the  rum  distillers  of 
the  advantage  of  such  a  plan,  that  they  soak  woollen  cloths  in  the  yeast  of  the  ferment- 
ing vats,  m  order  to  preserve  a  ferment  from  one  sugar  season  to  another.  In  Jamaica 
and  some  other  of  our  colonies,  50  gallons  of  spent  wash  or  lees  are  mixed  with  6  gal- 
lons of  molasses,  36  gallons  of  sugar-pan  skimmings  (a  substance  rich  in  aroma),  and 
8  gallons  of  water;  in  which  mixture  there  is  about  one  twelfth  part  of  solid  saccha- 
rum. Those  who  attend  more  to  the  quality  than  the  quantity  of  their  rum,  will  use 
a  smaller  proportion  of  the  spent  wash,  which  is  always  empyreumatic,  and  imparts  more 
or  less  of  its  odor  to  the  spirit  distilled  from  it.  The  fermentation  is  seldom  complete 
in  less  than  9  days,  and  most  commonly  it  requires  from  12  to  15;  the  period  being 
dependant  upon  the  capacity  of  the  fermenting  tun,  and  the  quality  of  its  contents! 
The  liquid  now  becomes  clear,  the  froth  having  fallen  to  the  bottom,  and  few  bubbles 
nnSf  aif/^t"c*led  from  It,  while  its  specific  gravity  is  reduced  from  1-050  down  tc 
0-992.    The  sooner  it  is  subjected  to  distillation  after  this  period,  the  better,  to  prevem 


the  loss  of  alcohol  by  the  supervention  of  the  acetous  stage  of  fermentation,  an  accident 
very  liable  to  happen  in  the  sugar  colonies.  The  crude  spirit  obtained  from  the  large 
single  SI  ill  at  the  first  operation,  is  rectified  in  a  smaller  still.  About  114  gallons  of 
rum,  proof  streosth,  specific  gravity  0-920,  are  obtained  from  1200  gallons  of  wash. 
Now  these  1200  erallons  weigh  12,600  lbs.,  and  contain  nearly  one  eighth  of  their  weight 
of  sugar=1575  lbs.;  which  should  yield  nearly  its  own  weight  of  proof  spirit,  whose 
bulk  is  =  h57s  =  ni2  pound  measures=17l-2  gallons;  whereas  only  114  are  obtained; 
proving  the  processes  to  be  conducted  in  a  manner  far  from  economical,  even  with  every 
reasonable  allowance. 

Mr.  Edwards  gives  the  following  estimate:  "The  total  amount  of  sweets  from  an 
estate  in  Jamaica  which  makes  200  hogsheads  of  sugar,  is  16,666  gallons.  The  wash  set 
at  the  rate  of  12  per  cent,  sweets  should  return  34,720  gallons  of  low  wines,  which  should 
give  14,412  gallons  of  rum,  or  131  puncheons  of  110  gallons  each." 

By  my  own  experiments  on  the  quantity  of  proof  spirit  obtainable  from  molasses  by  fer- 
mentation (afterwards  to  be  detailed),  one  gallon  of  sweets  should  yield  one  gallon  of 
spirit;  and  hence  the  above  16,666  gallons  should  have  afforded  the  same  bulk  of  rum. 
But  here  we  are  left  somewhat  in  the  dark,  by  not  knowing  the  specific  gravity  of  the  mm 
spoken  of  by  Mr.  Edwards.  The  only  light  let  in  upon  us  is  when  he  mentions  rum  oil- 
proof,  that  is,  a  spirit  in  which  olive  oil  will  sink ;  indicating  a  density  nearly  the  same 
with  our  actual  excise  proof,  for  olive  oil  at  60°  F.  has  the  specific  gravity  0-919.  When 
a  solution  of  sugar  of  the  proper  strength  is  mixed  with  wine  lees,  and  fermented,  it 
affords  a  spirit  by  distillation  not  of  the  rum,  but  of  the  brandy  flavor. 

The  sweet  juices  of  palm  trees  and  cocoa  nuts,  as  also  of  the  maple,  and  ash,  birch, 
&c.,  when  treated  like  cane  juice  afford  vinous  liquors  from  which  ardent  spirits,  under 
various  names,  are  obtained  ;  as  arrack,  &c. ;  the  quantity  being  about  50  pounds  of 
alcohol  of  0-825  for  every  100  pounds  of  solid  saccharine  extract  present.  Honey  sim- 
ilarly treated  affords  the  metheglin  so  much  prized  by  our  ancestors.  Good  whey,  freed 
from  curd  by  boiling,  will  yield  4  per  cent,  of  spirit  of  wine,  when  fermented  with  the 
addition  of  a  little  yeast. 

2.  The  juices  of  apples,  pears,  currants,  and  such  fruits,  afford  by  fermentation  quan. 
titles  of  alcohol  proportional  to  the  sugar  they  contain.  But  the  quality  of  the  spirit  is 
much  better  when  it  is  distilled  from  vinous  liquids  of  a  certain  age,  than  from  recently 
fermented  must.  Cherries  are  employed  in  Germany,  and  other  parts  of  the  Continent, 
for  making  a  high-flavored  spirit  called  Kirsch-wasser,  or  cherry  water.  The  fully  ripe 
fruit  is  crushed  by  a  roller  press,  or  an  edge-stone  mill,  along  with  the  kernels ;  the  pulp 
is  fermented  in  a  mass,  the  liquid  part  is  then  drawn  off,  and  distilled.  More  or  less 
prussic  acid  enters  from  the  kernels  into  this  spirit,  which  renders  it  very  injurious,  as  a 
liquor,  to  many  constitutions.  I  was  once  nearly  poisoned  by  swallowing  a  wine  glass  of 
it  in  the  valley  of  Chamouni.  The  ripened  red  fruit  of  the  mountain  ash  constitutes  a 
good  material  for  vinous  fermentation.  The  juice  being  mixed  with  some  water  and  a 
little  yeast,  affords  when  well  fermented,  according  to  Hermstaedt,  12  pounds,  or  1| 
gallons,  of  alcohol  from  2  bushels  of  the  ripe  berries. 

3.  Many  roots  contain  sugar,  particularly  beet,  from  which  no  less  than  7  per  cent,  of 
it  may  be  extracted  by  judicious  means.  Hermstaedt  recommends  to  mash  the  steam 
boiled  clean  roots,  and  add  to  the  paste  two  thirds  of  its  weight  of  boiling  water,  and  a 
thirtieth  of  its  weight  of  ground  malt,  mixing  the  materials  well,  and  then  leaving  them 
three  hours  in  a  covered  vessel.  The  mixture  must  now  be  passed  through  a  wire  sieve, 
with  meshes  of  one  third  of  an  inch  square  each  ;  the  residuum  is  washed  with  a  little 
cold  water,  and,  when  the  temperature  has  fallen  to  77°  F.,  the  proper  quantity  of  yeast 
must  be  added,  and  the  fermentation  suffered  to  proceed  in  a  covered  tun.  In  5  or  6 
days  it  will  be  complete,  and  will  afford  by  distillation,  from  100  pounds  of  beet  root, 
about  10  or  12  pounds  of  proof  spirits.  Carrots  and  parsnips,  when  similarly  treated, 
yield  a  considerable  quantity  of  alcohol. 

II.  JlrderU  spirits  or  whiskey  from  feciila  or  starchy  materials, 

I  have  already  pointed  out,  in  the  article  Beer,  how  the  starch  is  transformed  into  a 
saccharine  condition,  by  malting  and  mashing;  and  how  a  fermentable  wort  may  be  ob- 
tained from  starchy  meal.  By  like  operations  may  all  vegetable  substances,  which  con- 
sist chiefly  of  starch,  become  materials  for  a  whiskey  distillery.  To  this  class  belong 
all  the  farinaceous  grains,  potatoes,  and  the  pods  of  shell  fruits,  as  beans,  vetches,  horse- 
ehestnuts,  acorns,  &c. 

1.  Whiskey  from  com.  All  those  species  of  corn  which  are  employed  in  breweries 
answer  for  distilleries  ;  as  wheat,  rye,  barley,  and  oats ;  as  well  as  buckwheat,  and  maize  or 
Indian  com.  The  product  of  spirits  which  these  different  grains  afford,  depends  upon 
the  proportion  of  starch  they  contain,  including  the  small  quantity  of  uncrystallizable 
sugar  present  in  them.  Hermstaedt,  who  has  made  exact  experiments  upon  the  subject, 
reckons  a  quart  (Prussian  or  British)  of  spirits,  containing  30  per  cent,  of  the  absolute 
alcohol  of  Richter,  for  2  pounds  of  starch.    Hence  100  pounds  of  starch  should  yield 


586 


DISTILLATION. 


DISTILLATION. 


587 


pfoS.'*'*'^*  ""^  *^'''*^°^ '  *''"  ^'^^^  ^*"°"^  imperial,  equal  to  7-8  gallons  of  spirits,  excise 

100  pounds  of  the  following  grains  afford  in  spirits  of  specific  gravity  0  94'>7  coa 
taming  45  per  cent,  of  absolute  alcohol,  (=  ^9^  of  British  proof,)  the  following  ^uan- 

Wheat,  40  to  45  pounds  of  spirits ;  rye,  36  to  42;  barley,  40;  oats,  36 ;  buckwheat, 
40;  maize,  40.  The  mean  of  the  whole  may  be  taken  at  40  pounds,  equal  to  41  gallons 
imperial,  of  0-9427  specific  gravity  =  3-47  gallons,  at  excise  proof.  The  chief  difference 
in  these  several  kinds  of  corn  consists  in  their  different  bulks  under  the  same  weight;  a 
matter  of  considerable  importance ;  for  since  a  bushel  of  oats  weighs  little  more  than  the 
half  of  a  bushel  of  wheat,  the  former  becomes  for  some  purposes  less  convenient  in  use 
than  the  latter,  though  it  affords  a  good  spirit. 

Barley  and  rye  are  the  species  of  grain  most  commonly  employed  in  the  European 
distilleries  for  making  whiskey.  Bariey  is  mostly  taken  either  partly  or  altogether  ia 
the  malted  state;  while  the  other  corns  are  not  malted,  but  merely  mixed  with  a  certain 
propor  ion  of  bariey  malt  to  favor  the  saccharine  fermentation  in  the  mashing.  It  is 
deemed  preferable  to  use  a  mixture  of  several  sorts  of  grain,  instead  of  a  single  one;  for 
example,  wheat  with  barley  and  oats ;  or  barley  with  rye  and  wheat;  for  the  husks  of 
the  oats  diffused  through  the  wheat  flour  and  rye  meal  keep  it  open  or  porous  when 
mashed,  and  thus  favor  the  abstraction  of  the  wort ;  whUe  the  gluten  of  the  wheat  tends 
to  convert  the  starch  of  the  barley  and  oats  into  sugar.  When  the  whole  of  the  grain, 
however,  is  malted,  a  much  more  limpid  wort  is  obtained  than  from  a  mixture  of  malt 
with  raw  gram  ;  hence  the  pure  malt  is  preferable  for  the  ale  and  porter  brewer,  while 
the  mixture  affords  a  larger  product,  at  the  same  cost  of  materials  to  the  distiller.  Whea 
barley  is  the  only  gram  employed,  from  one  third  to  one  sixth  of  malt  is  usually  mixed 
with  It;  but  when  wheat  and  rje  are  also  taken,  the  addition  of  from  one  eighth  to  one 
sixteenth  of  bar  ey  mall  is  sufficient.  Oats  are  peculiariy  proper  to  be  mixed  with  wheaL 
to  keep  the  meal  open  in  the  mashing. 

The  following  are  the  proportions  used  by  some  experienced  Scotch  distillers. 
250  bolls,  containing  6  bushels  each,  being  used  for  a  mashing,  consist  of. 


25  bolls  of  oats,  weighing  284  lbs.  per  boll,  or  47|  lbs.  per  bushel: 
42  malt  240  40 

25  rve  320  53 1 


158 


250 


barley 


320 


53i 
mean  48| 


From  each  boll,  weighing  291  lbs.,  14  imperial  gallons  of  proof  whiskey  are  obtained 
on  an  average;  equivalent  to  11-2  gallons  at  25  over  proof. 

The  malting  for  the  distilleries  is  to  be  conducted  on  the  same  principles  as  for  the 
breweries,  but  the  malt  ought  to  be  lightly  kiln-dried,  and  that  preferably  at  a  steam  heat, 
instead  of  a  hre,  which  is  apt  to  give  an  empyreumatic  smell  to  the  grain  that  passes  into 
tlie  spirit?  For  ruch  persons,  indeed,  as  relish  the  smell  of  burned  turf,  called  i.eat-reek 
m  Scotland,  the  malt  should  be  dried  by  a  turf  fire,  whereby  the  whiskey  will  acquire 
that  peculiar  odor.  ^ 

But  this  smell,  which  was  originally  prized  as  a  criterion  of  whiskey  made  from  pure 
malt,  moderately  fermented  and  distilled  with  peculiar  cire,  has  of  late  years  lost  its 
value,  since  the  artifice  of  impregnating  bad  raw  grain  whiskey  with  peat-smoke  has  been 
extensively  practised. 

Dr.  Kolle,  in  his  treatise  on  making  spirits,  describes  a  malting  kiln  with  a  copper 
plate  heated  with  steam,  18  feet  long,  and  12  feet  broad,  on  which  a  quantity  of  malt 
bein?  spread  thm,  is  changed  every  3  or  4  hours,  so  that  in  24  hours  he  turns  out  upwards 
of  28  cwt.  of  an  excellent  and  well  kilned  article.  The  malt  of  the  distiller  should  be  as 
pale  as  possible,  because  with  the  deepening  of  the  color  an  empyreumatic  principle  is 

When  Indian  corn  is  the  subject  of  distillation,  it  must  be  malted  in  the  same  way  as 
described  in  the  article  Beer.  According  to  Hermstaedt,  its  flour  may  be  advan- 
tageously mixed  with  the  crushed  malt  in  the  mash  tun.  But  its  more  complete  dissolu- 
tion may  be  accomplished  by  Siemen's  mode  of  operating  upon  potatoes,  presently  to  be 

1.  Mashing.  Barley  and  raw  grain  are  ground  to  meal  by  millstones,  but  malt  is  mereij 
crushed  between  rollers.  If  only  one  tenth  or  one  eighth  of  malt  be  used  with  nine 
tenths  or  seven  eighths  of  bariey,  some  husks  of  oats  are  added,  to  render  the  mash 
raixture  more  drainable. 

When  40  bushels  of  bariey  and  20  of  malt  form  one  mashing,  from  600  to  700 
gallons  of  water,  heated  to  150°  F.,  are  mixed  with  these  60  bushels  in  the  mash  tun, 


and  carefully  incorporated  by  much  manual  labor  with  wooden  oars,  or  in  great  concerns 
by  the  mechanical  apparatus  used  in  the  breweries.  This  agitation  must  be  continued 
for  2  or  3  hours,  with  the  admission  from  time  to  time  of  about  400  additional  gallons  of 
water,  at  a  temperature  of  190°,  to  counteract  the  cooling  of  the  materials.  But  since 
the  discovery  of  diastasey  as  the  best,  heat  for  saccharifying  starch  is  shown  to  be  not 
higher  than  160°  F.,  it  would  be  far  better  to  mash  in  a  tun,  partially,  at  least,  steam 
incased,  whereby  we  could  preserve  the  temperature  at  the  appropriate  degree  for  gene- 
rating the  greatest  quantity  of  sugar. 

If  the  wort  be  examined  every  half-hour  of  the  mashing  period,  it  will  be  found 
to  become  progressively  sweeter  to  the  taste,  thinner  in  appearance,  but  denser  in 
reality. 

The  wort  must  be  drawn  off  from  the  grains  whenever  it  has  attained  its  maximum 

density,  which  seldom  exceeds  150  lbs.  per  barrel ;  that  is, jt =  1*42,  or  42 

'360 

per  cent.  As  the  corn  of  the  distiller  of  raw  grain  has  not  the  same  porosity  as  the 
brewer's,  the  wort  cannot  be  drawn  off  from  the  bottom  of  the  tun,  but  through  a  series 
of  holes  at  the  level  of  the  liquor,  bored  in  a  pipe  stuck  in  at  the  corner  of  the  vessel. 
About  one  third  only  of  the  water  of  infusion  can  thus  be  drawn  off  from  the  pasty 
mass.  More  water  is  therefore  poured  on  at  the  temperature  of  190°,  well  mixed  by" 
agitation  for  half  an  hour,  then  quietly  infused  for  an  hour  and  a  half,  and  finally  draws 
off  as  before.  Fully  400  gallons  of  water  are  used  upon  this  occasion,  and  nearly  as 
much  liquor  may  be  drawn  off.  Lastly,  to  extract  from  the  grains  everything  soluble, 
about  700  gallons  of  boiling  hot  water  are  turned  in  upon  them,  thoroughly  incorpo- 
rated, then  left  quietly  to  infuse,  and  drawn  off  as  above.  This  weak  wort  is  commonly 
reserved  for  the  first  liquor  of  the  next  mashing  operation  upon  a  fresh  quantity  of  meal 
and  malt. 

The  English  distiller  is  bound  by  law  to  make  his  mixed  worts  to  be  let  down  into  the 
fermenting  tun  of  a  specific  gravity  not  less  than  1*050,  nor  more  than  1  090;  the  Scotch 
and  Irish  distillers  not  less  than  1*030,  nor  more  than  1*080;  which  numbers  are  called, 
gravity  50,  90,  30,  and  80,  respectively. 

With  the  proportion  of  malt,  raw  grain,  and  water,  above  prescribed,  the  infusion  first 
drawn  off  may  have  a  strength  =  20  per  cent.  =  spec.  grav.  1*082,  or  73  lbs.  per  barrel ; 
the  second  of  50  lbs.  per  barrel,  or  14  per  cent. ;  and  the  two  together  would  have  a 
strength  of  61*2  lbs.  per  barrel  =  17  per  cent.,  or  spec.  grav.  1*070.  From  experiments 
carefully  made  upon  a  considerable  scale,  it  appears  that  no  more  than  four  fifths  of  the 
soluble  saccharo-starchy  matter  of  the  worts  is  decomposed  in  the  best  regulated  fermen- 
tations of  the  distiller  from  raw  grain.  For  every  2  lbs.  so  decomposed,  1  lb.  of  alcohol, 
spec.  grav.  0*825,  is  generated ;  and  as  every  gallon  of  spirits  of  the  spec.  grav.  0*909 
contains  4*6  lbs.  of  such  alcohol,  it  will  take  twice  4*6  or  9'2  lbs.  of  saccharine  matter  tc 
produce  the  said  gallon.  To  these  9*2  lbs.,  truly  transmuted  in  the  process,  we  must  add 
one  fifth,  or  1*84  lbs.,  which  will  raise  to  11*04  the  amount  of  solid  matter  employed  in 
producing  a  eallon  of  the  above  spirits. 

Some  distillers  mash  a  fourth  time ;  and  always  use  the  feeble  wort  so  obtained  ia 
mashing  fresh  grain. 

2.  As  the  imperfect  saccharine  infusion  obtained  from  raw  grain  is  much  more  aces- 
cent than  the  rich  sugary  solution  got  from  malt  in  the  breweries,  the  distiller  must 
use  every  precaution  to  cool  his  worts  as  quickly  as  possible,  and  to  keep  them  clear  from 
any  acetous  taint.  The  different  schemes  of  cooling  worts  are  considered  under  Beer 
and  Refrigeration.  As  the  worts  cool,  a  quantity  of  starchy  matter  is  precipitated,  but 
it  is  all  carefully  swept  along  into  the  fermenting  tun,  and  undoubtedly  contributes  to  in- 
crease the  production  of  alcohol.  During  the  winter  and  temperate  months,  when  the 
distilleries  are  most  actively  at  work,  the  temperature  at  which  the  worts  are  set  is 
usually  about  70°  F.  When  much  farinaceous  deposite  is  present,  the  heat  may  be  only 
65°,  because,  in  this  case,  a  slow  fermentation  seems  to  favor  the  conversion  of  that 
starch  into  sugar.  In  some  German  distilleries  a  little  chalk  is  mixed  with  the  worts,  to 
check  acidity. 

3.  The  fermentation. 

The  yeast  added  to  the  worts  as  a  ferment,  ought  to  be  the  best  top  barm  of  the 
London  porter  breweries.  About  1  gallon  of  it  is  requisite  for  every  2  bushels  of  meal 
and  malt  worked  up  in  the  mashing  process ;  and  of  this  quantity  only  a  certain  propor- 
tion is  introduced  at  the  beginning;  the  remainder  being  added  by  degrees,  on  the  second 
and  third  days. 

Should  the  fermentation  flag,  a  little  more  may  be  added  on  the  fourth  or  fifth  day, 
and  the  contents  of  the  tun  may  be  roused  by  an  agitator.  About  8  or  9  gallons  may  be 
introduced  four  days  in  succession  to  the  quantity  of  worts  extracted  from  60  bushels  of 
the  farinaceous  materials ;  or  the  third  day's  dose  may  be  intermitted,  and  joined  to  the 
fourth  on  the  subsequent  day. 


588 


DISTILLATION. 


DISTILLATION. 


589 


Great  diversity  and  no  little  caprice  prevail  amons  distillers  in  respect  of  the  periods  of 
administering  the  yeast ;  but  they  should  be  governed  very  much  by  the  appearance  of 
the  fermentation.  This  process  continues  from  nine  to  twelve  or  even  fourteen  days, 
accordin*'  to  circumstances ;  the  tuns  being  left  quite  open  during  the  first  five  days,  but 
being  covered  moderately  close  afterwards  to  favour  the  full  impregnation  of  the  liquor 
with  carbonic  acid,  as  a  fermenting  agent.  In  consequence  of  the  great  attenuation  of 
the  wort  by  the  generation  of  so  much  alcohol,  no  good  body  of  yeast  continues  to  float 
on  the  surface,  and  what  is  formed  is  beat  down  into  the  liquor  on  purpose  to  promote 
the  fermentation.  The  temperature  of  the  wash  gradually  increases  till  towards  the  end 
of  the  fourth  day,  when  it  attains  its  maximum  height  of  about  25°  above  the  pilch  of 
65°  or  60°  at  which  it  may  have  been  set.  The  time  of  the  greatest  elevation  of  tem- 
perature, as  well  as  its  amount,  depends  conjointly  upon  the  quality  of  the  yeast,  the 
nature  of  the  saccharo-slarchy  matter,  and  the  state  of  the  weather.  It  is  highly  pro- 
bable that  the  electrical  condition  of  the  atmosphere  exercises  a  considerable  influence 
upon  fermentation.  We  know  the  power  of  a  thunder-storm  to  sour  vinous  fluids.  An 
experimental  inquirv  into  the  relation  between  electricity  and  fermentation,  could  not  fail 
to  prove  both  curious  and  profitable.  ,      ,.    •„  u 

The  dimunition  of  the  density  of  the  wort  is  carefully  watched  by  the  distiller,  as  the 
true  criterion  of  the  success  of  his  process.     This  attenuation^  as  he  calls  it,  is  owing 
partly  to  the  decomposition  of  the  sugar,  which  communicated  its  gravity  to  the  solution, 
and  partly  to  the  introduction  of  the  lighter  alcoholic  particles.     Were  a."  the  saccharo- 
starchy  matter  resolved  into  gaseous  compounds,  the  wort  would  become  water ;  out  since 
a  part  of  it  remains  undecomposed,  and  a  portion  of  alcohol  is  produced  at  the  expense 
of  the  decomposed  part,  the  degree  of  attenuation  becomes  a  somewhat  complicated  pro- 
blem in  a  theoretical  point  of  view ;  the  density  due  to  the  residuary  sugar  being  masked 
and  counteracted  by  the  spirit  evolved.     Could  the  alcohol  be  drawn  off"  as  it  is  formed, 
the  attenuation  would  probably  become  greater,  because  the  alcohol  checks  the  fermenta- 
tive action,  and  eventually  stops  it,  before  all  the  saccharum  is  decomposed.     After  the 
wash  has  taken  its  highest  degree  of  temperature,  not  much  more  spirit  is  found  to  be 
generated ;  were  this  therefore  removed  by  proper  means,  the  remaining  vegetable  mat- 
ter would  undoubtedly  yield  a  further  product  of  alcohol.  ,  «/.«     v  ♦ 
In  the  attenuation  of  raw-grain  wash,  the  specific  gravity  seldom  arrives  at  1-000 ;  but 
most  commonlv  stops  short  at  1-002  or  1-004.     When  the  vinous  fermentation  comes  to 
an  end,  the  acetous  is  apt  to  commence,  and  to  convert  a  portion  of  the  alcohol  into  vin- 
egar -  a  result  which  is  easily  ascertained  by  the  increasing  specific  gravity,  sour  smell, 
and  acidulous  reaction  of  the  wash  upon  litmus  paper,  which  remains  after  the  paper  is 
heated,  showing  that  the  red  color  is  not  caused  by  carbonic  acid.  r    u     -i- 

Fermentation  proceeds  with  more  uniformity  and  success  in  the  large  tuns  of  the  dis- 
tiller, than  in  the  experimental  apparatus  of  the  chemist;  because  the  body  of  heat 
generated  in  the  former  case  maintains  the  action.  Bui  I  have  succeeded  in  obviating 
this  inconvenience  in  operating  upon  80  or  90  gallons,  by  keeping  up  the  temperature, 
when  it  begins  to  flag,  by  transmitting  hot  water  through  a  recurved  pipe  plunged  into 

the  tun.  -     .  .  .    .  r  • 

We  have  already  mentioned  that  one  gallon  of  spirits,  one  in  ten  over-proof,  is  upon 
the  average  generated  from  11-04  lbs.  of  starch  sugar;  hence  we  conclude  that  one 
pound  water-measure  of  spirits  at  proof  (=  .^-  imperial  gallon)  is  produced  from  one  pound 

of  the  saccharum.  ,    . 

Malt  whiskey.— The  treatment  and  produce  of  malt  distilleries  are  in  some  respects 
diflferent  from  those  of  raw  grain.  Having  been  professionally  emp  oyed  by  the 
proprietors  of  both,  I  am  prepared  to  state  the  peculiarities  of  the  latter,  by  an 
example.  500  bushels  of  ground  malt  are  first  mashed  with  9000  gallons  of  waler, 
heated  to  the  temperature  of  160°  F. :  6000  gallons  of  worts  are  drawn  off  mlo  the 
coolers,  and  let  down  into  the  fermenting  tun  at  68°.  From  3  to  4  per  cent,  of  a 
mixture  of  London  porter  yeast  with  quick  Scotch  barm  are  added,  and  well  stirred 
through  the  mass.  At  the  end  of  two  or  three  days,  in  general,  the  fermentation  is 
finished.  On  the  residuary  grains  of  the  malt,  from  4500  to  5000  gallons  of  waler  at 
180°  are  run,  which  after  proper  mashing  as  before,  are  drawn  oflf;  then  4500  more  are 
poured  on,  the  drainage  of  which  is  added  to  the  second.  Both  of  these  together,  con- 
Btituting  9000  gallons,  are  heated  next  day,  and  employed  for  the  mashing  of  500  bushels 
of  fresh  malt.  During  the  fermentation,  the  wash  which  was  set  at  the  spec.  grav.  1-065, 
comes  down  to  water  =  1-000. 

The  wash  is  distilled  in  two  stills,  appropriated  to  it,  of  about  800  gallons  capacity 
each  provided  with  a  rotatory  chain  apparatus  for  preventing  the  lees  from  adhering  to 
the  bottom  of  the  still.  Into  about  800  gallons  of  wash  8  lbs.  of  soap  are  put.  The 
Hquor  obtained  at  this  first  distillation  is  called  low  wines.  These  low  wines  are  redis* 
tiUcd  in  the  spirit  stills;  the  first  and  last  portions  of  liquid  being  "'«f«^^'*;*'f^,^'"^_^' 
■li^ky  in  color^  and  rank  in  flavor,  are  run  into  a  separate  receiver  called  the  faints-back  i 


While  the  middle  portion,  constituting  in  a  well-managed  distillery,  from  three  fourths  to 
four  fifths  of  the  whole,  are  received  into  the  spirit-back.  The  faints  are  mixed  with  a  largf 
quantity  of  water,  and  redistilled,  in  order  to  free  them  from  the  fetid  oil  derived  from 
the  husks  of  the  grain.  The  interception  of  this  noxious  oil  may  be  best  eftected  by  a 
self-regulating  bath,  between  the  capital  of  the  still  and  the  refrigeratory,  as  will  be 
explained  in  treating  of  Stills.  The  capitals  of  the  common  Scotch  stills  are  made  from 
15  to  20  feet  high,  in  order  to  prevent  the  chance  of  the  wash  boiling  over  into  the 
worm ;  and  they  are,  towards  the  beginning  of  the  process,  struck  from  time  to  time 
with  a  rod,  and  by  the  sound  emitted  it  is  known  whether  they  be  empty,  partially 
filled,  or  in  danger  of  an  overflow;  in  which  case  the  fire  is  damped,  by  a  spout 
near  the  furnace  door,  connected  by  a  leather  pipe  with  an  elevated  reservoir  of  wat"/. 
When  very  pure  spirits  are  wished  for,  a  third  or  even  a  fourth  distillation  is  had  recourse 
to ;  there  being  a  quantity  of  water  mixed  each  time  with  the  spirit  in  the  still,  to  pre- 
vent its  acquiring  a  harsh  alcoholic  flavor. 

According  to  some  experienced  distillers  from  raw  grain,  the  mashing  temperature  of 
the  first  liquor  should  not  exceed  140°  F. ;  whereas  with  malt  't  may  be  safely  and 
beneficially  165°  or  170°.  When  rye  is  used  instead  of  malt,  90  bushels  of  it  are  mixed 
with  190  bushels  of  raw  grain,  constituting  280  bushels  in  whole,  for  the  mashing  of 
which  5200  gallons  of  water  are  required.  An  hour  and  a  half  more  time  is  necessary 
for  settling  the  mashing  of  the  above  mixture,  than  of  grain  alone.  Gin  is  made  in  this 
way. 

The  distiller  of  malt  whiskey  calculates  on  obtaining  two  gallons  of  proof  spirits  from 
one  bushel  of  malt,  in  average  years.  The  highest  yield  is  20  gallons  per  quarter  of  8 
bushels ;  and  the  lowest  is  16,  when  the  malt  and  fermentation  are  indifferent.  The  best 
temperature  to  set  the  fermenting  tun  with  malt  wash  is  about  70°  or  72°  F. 

When  malt  is  5s.  the  bushel,  6  bushels  at  30*.  will  yield  12  gallons  of  proof  spirits. 
These  cost  therefore  2s.  6d.  per  gallon  for  the  malt ;  to  which  must  be  added  3d,  per 
bushel  for  the  amount  of  malt  duty  not  returned,  or  l§(f.  on  the  gallon ;  this  added  to  the 
Scotch  duty  of  3s.  Ad.  the  gallon,  makes  the  price  altogether  5s.  ll^d.;  besides  the  ex- 
penses in  fuel,  yeast,  labor,  and  rent,  which  may  be  estimated  at  8^d.  per  gallon.  But3(i. 
may  be  deducted  for  what  is  paid  by  the  dairymen  for  the  spent  wash  and  grains.  The 
total  cost,  therefore,  exclusive  of  use  of  capital,  is  6s.  5d.  per  gallon  in  Scotland. 

The  following  is  the  work  of  a  Scotch  distillery,  where  good  malt  whiskey  wa« 
made. 

One  bushel  of  the  malt  weighed  35  lbs.,  or  the  boll,  =  6  bushels,  210  lbs.  In  mashing 
each  boll  of  malt,  110  gallons  of  water  were  run  on  it  at  160°  F.  As  soon  as  the  fer- 
menting tun  of  3000  gallons  capacity  was  charged  with  the  wash  at  from  64°  to  74°  F.,  2 
gallons  per  cent,  of  barm  were  added.  When  the  wash  had  become  attenuated  from 
1-060  to  1-040,  another  gallon  of  barm  was  introduced. 

The  temperature  of  the  fermenting  wash  sometimes  rises  to  96°,  which  is,  however, 
an  extreme  case,  and  not  desirable.  When  the  bubbles  of  carbonic  acid  mount  in  rapid 
succession,  it  is  reckoned  an  excellent  sign.  If  the  tun  be  small,  and  stand  in  a  cool 
apartment,  it  should  be  started  at  a  higher  temperature  than  in  the  reverse  predicament. 
Should  the  fermentation  be  suffered  to  flag,  it  is  in  £,eneral  a  hopeless  task  to  /estore 
vigorous  action.  Some  try  the  addition  of  bubs,  that  is,  of  some  wort  brought  into  a  state 
of  rapid  fermentation  in  a  tub,  by  a  large  proportion  of  yeast,  but  seldom  with  much 
success.  Indeed,  the  law  prohibits  the  addition  of  any  wort  to  the  tun  at  a  later  period 
than  24  hours  after  it  is  set ;  so  that  if  bubs  are  used  afterwards,  the  distiller  is  apt  to 
incur  a  penalty. 

The  maximum  quantity  of  proof  spirits  obtained  on  the  great  scale  at  any  time  from 
raw  grain  mixed  with  from  one  fourth  to  one  eighth  of  malt,  seems  to  be  22  gallons  per 
quarter. 

By  the  British  laws  a  distille-^'S  not  allowed  to  brew  and  distil  at  the  same  time  j 
but  he  must  work  alternately,  one  week,  for  instance,  at  fermentation,  and  next  week  at 
distillation. 

In  fermenting  solutions  of  sugar  mixed  with  good  yeast,  the  attenuation  has  been 
carried  down  to  0*984,  and  even  0*982,  that  is,  in  the  language  of  the  excise,  16  and  18  de- 
grees below  water,  from  1*060,  the  density  at  which  it  was  originally  set  in  the  tun.  This 
was  excellent  work  done  on  the  scale  of  a  great  distillery  nearly  30  years  ago,  when  dis- 
tillation from  sugar  was  encouraged,  in  consequence  of  bad  corn  harvests. 

In  an  experiment  which  I  made  in  1831,  for  the  information  of  a  committee  of  the 
House  of  Commons,  on  the  use  of  molasses  in  the  breweries  and  distilleries,  I  dissolved 
1  cwt.  of  raw  sugar  in  water,  so  as  to  form  74^  gallons,  inclusive  of  2  gallons  of  yeast. 
The  specific  gravity  of  the  mixture  was  1-0593  on  the  31st  of  March.  By  the  6th  of 
April,  that  is,  in  6  days,  the  gravity  had  sunk  to  0-992,  or  8  degrees  under  water,  which 
was  reckoned  a  good  attenuation,  considering  the  circumstances  and  the  small  quantity 
operated  upon.  By  distillation  it  afforded  at  the  rate  of  14*875  gallons  of  proof  spiritt 
for  100  gallons  of  the  wash. 


/>90 


DISTILLATION. 


DISTILLATION. 


591 


li 


When  the  distillers  first  worked  from  sugar,  they  only  obtained  upon  an  average  from 
1  cwt.   10-09  gallons  imp.  of  proof  spirit;  but  they  afterwards  got  no  less  than  11-92 

imp.  gallons. 

The  following  experiment,  which  I  made  upon  the  fermentation  of  West  India  molasset 
into  spirits,  for^'the  information  of  the  said  committee,  may  prove  not  uninteresting  to 
my  readers.  150  lbs.  were  dissolved  in  water  and  mixed  with  2  gallons  of  yeast, 
weighing  exactly  20  lbs.  The  wash  measured  70  gallons,  and  had  a  spec,  gravity  of 
1-0647  at  60^  F.  In  two  days  the  gravity  had  fallen  to  1-0055;  in  three  days  to 
1*0022 ;  and  in  five  days  to  1-001.  The  temperature  was  Kept  up  at  from  80"  to  90"  F., 
during  the  last  two  days,  by  means  of  a  steam  pipe,  to  favor  the  fermentation.  The 
product  of  spirits  was  11  gallons,  and  ^^A  of  a  gallon.  Now  150  lbs.  of  the  above 
molasses  were  found  to  contain  of  solid  matter,  chiefly  uncrystallizable,  112  lbs.  And  as 
112  lbs.  of  sugar  are  estimated  by  the  revenue  laws  to  afford  by  fermentation  11^  gallons 
imp.  of  proof  spirit,  the  result  of  that  experiment  upon  molasses  must  be  considered 
satisfactory,  bearing  in  mind  that  the  saccharine  S"Hstance  in  molasses  has  been  not  only 
partially  decomposed  by  heat,  but  is  mixed  with  some  of  the  glutinous  or  extractive  mattei 
of  the  cane. 

Since  the  alteration  of  the  excise  laws  relative  to  distillation  in  1825  and  1826,  when 
permission  was  given  to  set  the  wort  at  lower  gravities,  the  quantity  of  spirits  produced 
from  1  quarter  of  corn  has  been  much  increased,  even  up  to  fully  20  gallons ;  and  the 
proportion  of  malt  has  been  much  diminished.  The  latter  was  soon  reduced  from  three 
sevenths  malt,  and  four  sevenths  barley,  or  two  fifths  malt  and  three  fifths  barley,  to  one 
fifth  of  malt  and  now  to  one  tenth  or  even  one  sixteenth. 

A  discussion  having  lately  taken  place  in  Ireland  between  certain  persons  connected 
with  the  distilleries  and  the  officers  of  the  excise,  whether,  and  to  what  extent,  raw 
grain  worts  would  pass  spontaneously  into  the  vinous  fermentation,  the  Board  in  London 
requested  me  to  superintend  a  series  of  researches  in  a  laboratory  fitted  up  at  their  office, 
to  settle  this  important  point.  I  shall  content  myself  here  with  giving  the  result  of  one 
experiment,  out  of  several,  which  seems  to  me  quite  decisive.  Three  bushels  of  mixed 
grains  were  taken,  consisting  of  two  of  barley,  one  half  of  oats,  and  one  half  of  malt, 
which,  being  coarsely  ground  by  a  hand-mill,  were  mashed  in  a  new  tun  with  24  gallons 
of  water  at  155".  The  mash  liquor  drawn  off  amounted  to  18  gallons,  at  the  density  of 
1-0465  ;  and  temperature  of  82°  F.  Being  set  in  a  new  tun,  it  began  to  ferment  in  the 
course  of  12  hours,  and  in  4  days  it  was  attenuated  down  to  gravity  1-012.  This  yielded, 
apon  distillation  in  low  wines,  322  gallons,  and  by  rectification,  in  spirits,  3*05 ;  while 
the  quantity  equivalent  to  the  attenuation  by  the  tables  was  3-31,  being  an  excellent 
accordance  in  such  circumstances. 

The  inquisitorial  regime  imposed  by  law  upon  our  distilleries,  might  lead  a  stranger 
to  imagine  that  our  legislators  were  desirous  of  repressing  by  every  species  of  annoyance 
the  fabrication  of  the  fiery  liquid  which  infuriates  and  demoralizes  the  lower  population 
of  these  islands.  But  alas!  credit  can  be  given  them  for  no  such  moral  or  philanthropic 
motive.  The  necessity  of  the  exchequer  to  raise  a  great  revenue,  created  by  the  wasteful 
expenditure  of  the  state,  on  the  one  hand,  and  the  efforts  of  fraudulent  ingen-iity  on  the 
other,  to  evade  the  payment  of  the  high  duties  imposed,  are  the  true  origin  of  that  regime. 
Examinations  in  distilleries  are  constantly  making  by  the  officers  of  excise.  There  is  a 
survey  at  6  o'clock  in  the  morning,  when  the  officers  take  their  accounts  and  gauges, 
and  make  calculations  which  occupy  several  hours.  At  10  o'clock  they  again  survey, 
going  over  the  whole  premises,  where  they  continue  a  considerable  time,  frequently  till 
the  succeeding  officer  comes  on  duly;  at  2  in  the  afternoon  another  survey  takes  place, 
but  not  by  the  same  people ;  at  6  in  the  evening  the  survey  is  repeated ;  at  10  there 
comes  another  survey  by  an  officer  who  had  not  been  engaged  in  any  of  the  previous 
surveys  of  that  day.  He  is  not  relieved  till  6  o'clock  next  morning.  In  addition  to  these 
regular  inspections,  the  distilleries  are  subject  to  frequent  and  uncertain  visits  of  the 
surveyor  and  general  surveyor.  "  We  are  never,"  says  Mr.  Smith,  the  eminent  distiller 
of  Whitechapel,  "  out  of  their  hands."* 

Before  the  fermented  wort  goes  into  the  still,  a  calculation  is  made  of  the  quantity 
of  wash  drawn  from  the  wash  back,  and  which  is  first  pumped  into  what  is  called  the 
wash  charger.  If  the  quantity  in  the  wash  charger  .  exceeds  the  quantity  in  the  wash 
back,  the  distiller  is  charged  upon  the  higher  quantity ;  if  it  contains  less,  he  must  pay 
according  to  the  wash  back,  as  being  the  larger  quantity.  When  the  quantity  of  wash  is 
all  transferred  to  the  charger,  the  discharge  cock  of  the  wash  charger  is  unlocked,  and 
the  wash  is  allowed  to  be  drawn  off  from  the  charger  into  the  still,  the  charging  and 
discharging  cock  of  the  still  being  locked  by  the  officer.  There  can  be  no  transfer  of 
wash  but  through  the  pumps,  which  are  locked  also.  The  first  distillation  from  the 
wash  is  worked  into  the  low-wine  receiver,  which  is  also  a  locked  up  vessel ;  then  of 

*  Report  of  Committee  on  Molasses,  2198. 


those  low  wiaes,  the  strength  and  quantity  are  ascertained  by  the  excise.  The  account 
of  them  afl^ards  a  comparison  with  the  quantity  which  the  contents  of  the  wash-fc<tck  had 
been  estimated  to  produce ;  they  are  then  pumped  from  the  low  wine  receiver,  through 
pumps  previously  locked  into  the  low  wine  charger,  which  is  also  a  locked  up  vessel; 
from  the  locked  up  charger,  after  the  officer  has  done  his  duty  regarding  it,  they  are  allow- 
ed to  be  drawn  off  into  the  low  wine  still,  which  is  a  distillation  of  the  second  extraction; 
then  that  low  wine  still  works  into  another  locked  up  cask,  called  the  spirit  receiver,  for 
the  receiving  of  raw  spirits  ;  when  that  distillation  is  finished,  the  officer,  attending  again 
on  regular  notice  for  that  purpose,  takes  the  quantity  and  strength  of  the  spirits  therein, 
and  upon  the  quantity  so  ascertained  he  charges  the  duty.  In  distilling  low  wines,  one 
portion  of  them  goes  into  the  spirit  receiver,  and  a  portion  into  what  is  called  the  faint 
receiver,  which  is  another  locked  up  vessel.  These  faints  are  in  the  next  distillation 
united  with  the  low  wines,  from  the  succeeding  wash-back  on  their  second  distillation, 
and  are  worked  together;  the  united  produce  of  these  goes  partly  into  the  spirit  cask, 
and  partly  back  again  into  the  faint  cask.  The  operation  is  thus  continued  till  all  the 
backs  in  the  house  are  emptied.* 

There  is  a  kind  of  ardent  spirits  manufactured  in  Holland,  vulgarly  called  Dutch  gin, 
Hollands,  and  sometimes  geneva^  from  genievre,  the  French  for  juniper,  a  plant  with  the 
essential  oil  of  whose  berries  it  is  flavored.  One  cwt.  of  ground  malt  mixed  with  two 
cwts.  of  rye  meal  are  mashed  for  two  hours,  with  about  450  gallons  of  water  at  the  tem- 
perature of  160**  F.  The  mash  drawn  off  is  reduced  with  cold  water  till  the  liquid  part 
has  the  density  of  45  lbs.  per  barrel,  =  specific  gravity  1-047  ;  and  is  then«put  all  together 
into  the  fermenting  back  at  the  temperature  of  80"  F.  One  or  two  gallons  of  yeast  are 
added.  The  fermentation  soon  becomes  so  vigorous  as  to  raise  the  heat  to  90"  and  up- 
wards, but  it  is  not  pushed  far,  being  generally  over  in  two  days,  when  the  gravity  of  the 
wash  still  indicates  12  pounds  of  saccharum  per  barrel.  By  this  moderate  attenuation 
like  that  practised  by  the  contraband  distillers  of  the  Highlands  of  Scotland,  it  is  supposed 
that  the  fetid  oil  of  the  husks  is  not  evolved,  or  at  least  in  very  small  quantity.  The 
grains  are  put  into  the  alembic  along  with  the  liquid  wash,  and  distilled  into  low  wines 
which  are  rectified  twice  over,  some  juniper  berries  and  hops  bein?  added  at  the  last  dis! 
tillation.  But  the  junipers  are  sometimes  bruised  and  put  into  the  mash.  The  produce 
of  worts  so  imperfectly  fermented,  is  probably  little  more  than  one  half  of  what  the 
British  distiller  draws  from  the  same  quantiiy  of  grain.  But  the  cheapness  of  labor  and 
of  grain,  as  well  as  the  superior  flavor  of  the  Skiedam  spirits,  enables  the  Dutch  distiller 
to  carry  on  his  business  with  a  respectable  profit.  In  opposition  to  the  above  facts  Du- 
brunfaut  says  that  about  one  third  more  spirits  is  obtained  in  Holland  from  grain  than  in 
France,  because  a  very  calcareous  spring  water  is  employed  in  the  mashing  operation 
Were  this  account  well  founded,  all  that  the  distillers  of  other  countries  would  have  to  do 
would  be  merely  to  introduce  a  portion  of  chalk  into  their  mash  tuns,  in  order  to  be  on  a 
par  with  the  Dutch.    But  the  statement  is  altogether  a  mistake. 

In  the  vine  countries,  the  inferior  wines  or  those  damaged  by  keeping,  as  ako  a  fer- 
mented mash  of  the  pressed  grapes,  mixed  with  water,  are  distilled  to  form  the  eau  devli 
de  Cognac  of  the  French,  called  Brandy  in  this  country.     It  contains  less  essential  c'l 
and  that  of  a  more  agreeable  flavor,  than  corn  spirits.     See  Brandy.  * 

Berzelius  says  that  there  are  distillers  v.'ho  are  guilty  of  putting  a  little  arsenious  acid 
into  the  still ;  that  the  spirits  contain  pretty  frequently  traces  of  arsenic,  which  may  be 
detected  by  adding  to  them  a  little  muriatic  acid,  then  evaporating  off  the  alcohol  and 
passing  a  current  of  sulphureted  hydrogen  gas  through  the  residuary  liquid,  which  will 
give  it  the  characteristic  orpiment  yellow  tinge,  arstnic  being  present.  Copper  which  is 
sometimes  introduced  into  distilled  grain,  or  even  malt  spirits,  in  consequence  of  the  soap 
employed  in  the  process  of  distillation,  may  be  detecfr/l  best  by  the  brown  precipitate  which 
it  occasions  with  ferroprussiate  of  potash.     No  arsc^  c  is  ever  used  in  this  country. 

When  damaged  grain  has  been  mashed  in  makina:  whiskey,  a  peculiar  oily  sul^tance 
makes  its  appearance  in  it.  On  approaching  the  nostrils  to  such  whiskey  slightly  heated 
this  volatile  matter  irritates  the  pituitary  membrane  and  the  eyes  very  powerfully.  These 
*pirits  have  exactly  the  smell  of  an  alcoholic  solution  of  cyanogene ;  they  intoxicate  more 
powerfully  than  pure  alcohol  of  equal  strength,  and  produce  even  temporary  phren-^v 
with  subsequent  sickness  and  disordered  functions.  This  volatile  body  is  not  cvano«'ene* 
though  it  be  so  like  it,  for  it  forms  no  such  combinations  as  cyanogene  doe-*.  It  may  be 
extracted  from  diluted  alcohol  by  agitating  it  with  an  unctuous  oil,  and  then  distillin«»  the 
oil  along  with  water.  At  the  end  of  3  or  4  months,  this  volatile  matter  disappears'in  a 
great  measure,  even  when  the  spirits  impregnated  with  it  are  enclosed  in  well-corked 
bottles ;  obviously  from  its  undergoing  a  spontaneous  decomposition.  It  may  be  preserv- 
ed much  longer  in  the  state  of  a  watery  solution. 

When  acetic  ether  is  added  to  well  purified  or  clean  spirits,  such  as  the  distillers  call 

♦  Thomas  Smith,  Esq.,  of  Whitechapel  Road,  in  Report  of  Molasses  Committee,  Part  II.  p  149 

38 


592 


DISTILLATION. 


DISTILLATIOIf. 


593 


•  i 


rilent  whiskey,  it  gives  it  somewhat  of  the  flavor  of  brand)'.  For  this  purpose,  also,  the 
spirits  are  rectified  from  bruised  prunes,  or  the  lees  of  the  cognac  disiilleries,  whereby 
they  acquire  additional  flavor.  The  astringent  taste  of  old  brandy  is  imitated  by  the  in- 
troduction of  a  little  catechu  into  the  British  spirits.  Burned  sugar  is  employed  as  a 
coloring  in  these  imitations. 

IV.  Of  making  whiskey  from  potatoes. — This  root,  in  certain  localities  where  it 
abounds  at  a  moderate  price,  is  an  excellent  material  for  fermenting  into  alcohol.  When 
sound,  it  possesses  from  20  to  25  per  cent,  of  solid  substance,  of  which  starch  consti- 
tutes at  least  three  fourths ;  hence  100  pounds  contain  from  16  to  22  pounds  of  starch 
susceptible  of  being  saccharified.  In  the  expressed  juice  there  is  a  small  quantity  of 
tartaric  acid. 

Previously  to  mashing,  potatoes  must  be  first  well  washed  in  a  horizontal  cylindrical 
cage  revolving  partially  in  a  trough  of  water,  as  will  be  described  in  tix^ting  of  the 
manufacture  of  sugar  from  beet  root.  They  must  be  then  boiled  in  a  close  vessel  with 
steam,  provided  with  a  perforated  bottom  a  few  inches  above  the  real  one.  The  top  has 
an  opening  with  a  cover  fitted  tightly  to  it ;  through  that  the  potatoes  are  intr'iuced ; 
and  immediately  above  the  false  bottom  there  is  a  similar  aperture  through  which  the 
boiled  potatoes  are  taken  out.  The  steam-pipe  enters  at  the  top,  runs  down  the 
side  a  little  way,  and  terminates  in  a  widened  mouth.  The  large  lids  are  secured  by 
cross  bars,  the  small  hole  by  folds  of  linen.  In  the  lower  valve  there  are  two  small  holes 
closed  with  pins,  for  inserting  a  wire  to  feel  whether  the  potatoes  be  suflicienlly  boiled. 
If  so,  the  steam  is  immediately  stopped  oflT,  the  lower  lid  is  removed,  and  the  potatoes 

pulled  out  with  a  hook  into  a 
tub.  They  must  be  imme- 
diately made  into  a  homoge- 
neous paste  before  they  get 
cold.  Fig.  464  represents,  in 
plan,  or  horizontal  section,  the 
apparatus  used  in  France  for 
this  purpose,  a  b  are  two 
cylinders  covered  with  wire 
cloth,  but  open  at  the  ends; 
c  c  and  d  d  are  two  pieces  of 
wood  fixed  on  the  two  axes, 
in  the  form  of  two  cones,  with 
the  adjoining  surfaces  trun- 
cated; upon  which,  as  also 
upon  iron  rings  £  f,  of  the 
same  diameter,  made  fast  to 
G  H,  the  smaller  has  18,  the 
is   14  inches,  the  length   18. 


the  axes,  the  wire  cylinder  rests.     Of  the  two  wheels 

greater  has  21   teeth.     The  diameter  of  each  cylinder 

Above  and  between  the  two  cylinders,  there  is  a  hopper  for  the  reception  of  the  boiled 

potatoes.     This  machine  triturates  1200  pounds  of  potatoes  per  hour.     Their  paste  must 

be  forthwith  mashed  with  some  ground  wheat  or  barley,  and  a  proportion  of  malt ;  then 

be  set  a  fermenting. 

As  in  the  above  mode  of  trituration,  the  potatoes  are  apt  to  cool  to  such  a  degree  as  to 
obstruct  their  ready  admixture  with  water,  it  is  better  to  make  them  into  a  paste  in  the 
vessel  in  which  they  are  steamed.  The  apparatus  contrived  by  Siemens  fully  answers 
this  end.  It  consists  essentially  of  a  tub  a,  represented  in  fig.  465,  in  section.  It  is 
cylindrical,  and  made  of  planks  from  3  to  4  inches  thick,  joined  firmly  and  steam-tight; 
the  upper  and  under  ends  being  well  secured  with  iron  hoops.  The  lower  part  is  about  2 
inches  more  in  diameter  than  the  upper.  About  a  foot  from  the  bottom,  in  a  circular 
groove,  a  cast  iron  partition  w,  or  disc  full  of  holes,  is  made  fast,  which  serves  the  pur- 
pose of  a  searce,  the  apertures  being  an  inch  asunder ;  above,  from  |  to  ^L  of  an  inch 
in  diameter,  and  below,  scooped  out  to  half  an  inch.  This  disc  is  half  an  inch  thick  in 
the  edges,  and  five  fourths  of  an  inch  in  the  middle. 

Through  the  female  screw  a  in  the  top  of  the  cylinder,  there  passes  the  screwed 
rod  b,  one  and  a  half  inches  thick,  provided  at  top  with  a  strong  cross  bar  c  c,  for 
turning  it  round.  The  under  end  of  this  rod  has  a  square  piece  terminating  in  a  short 
screw,  upon  which  a  wrought  iron  cross  is  secured  by  means  of  a  ^crew  nut, 
so  as  to  stand  at  right  angles  to  the  rod.  This  cross  is  composed  of  two  distinct 
arms ;  of  ^hich  one  of  them  is  mounted  on  the  upper  side  with  little  knives  an  inch 
and  a  half  long ;  the  other,  upon  the  under  side,  with  a  Wire  brush,  that  may  be  made 
to  rub  against  the  perforated  cast  iron  disc.  On  the  side  of  the  cylinder  at  e,  fig.  465, 
there  is  a  narrow  aperture  provided  with  a  bung  secured  by  a  cross  bar,  and  near  the 
bottom  at  h  there  is  another  like  it.  Both  openings  serve  for  taking  out  the 
residuary  matter.  Through  the  opening  e,  the  above  two  arms  are  introduced ;  and 
•ecured  to  the  square  of  the  rod  by  the  screw  nut.     In  the  top  there  is  an  opening,,!)^ 


for  putting  in  the  potatoes  which  may  be  shut  in  the  same  way.  From  the  lid  there 
likewise  issues  a  lateral  tube  f,  which  terminates  in  a  tubful  of  waier,  for  condensing 
the  waste  steam,  g  is  the  tube  connected  with  the  steam  boiler,  for  conducting  the  steam 
into  the  space  under  the  iron  disc  w. 

With  this  apparatus  the  potatoes  are  prepared  as  follows :  when  the  screw  rod  is  so 
fixed  that  the  cross  touches  the  disc,  the  cylinder  is  to  be  filled  with  washed  potatoes  to 
within  one  foot  of  the  top,  leaving  them  some  space  to  expand.  The  orifice  d  is  to  be 
then  closed,  and  the  steam  admitted.  When  the  potatoes  are  boiled  enough,  two  laborers 
lay  hold  of  the  lever  handles  c  c,  of  the  screw  rod  b,  and  turn  it  round  with  the  effect  of 
screwing  up  the  spiked  cross,  and  of  triturating  the  potatoes ;  an  operation  which  may 
be  still  more  effectually  done  by  screwing  it  down  again.  The  potato  paste  is  now  let 
off  by  the  plug  hole  h.  into  the  tub  l,  where  it  is  mixed  with  about  30  per  cent,  of  boil- 
ing water,  and  one  thousandth  part  of  potash,  made  caustic  with  quicklime,  in  order  to 
dissolve  the  albuminous  matter  coagulated  by  the  heat,  and  give  complete  fluidity  to  the 
mass.  The  alkali  also  neutralizes  the  tartaric  acid  present.  The  mashed  matter  must 
now  be  mixed  with  the  crushed  malt  diffused  through  40  or  50  pounds  of  cold  water  for 
every  100  pounds  of  potatoes,  which  lowers  the  temperature  to  167*.  The  wort  must 
be  then  diligently  stirred  during  two  hours;  mixed  with  40  or  50  pounds  of  cold  water 
for  100  pounds  of  potatoes,  and,  when  reduced  to  the  temperature  of  77°,  put 
into  the  fermenting  tun  along  with  the  proper  quantity  (3  or  4  per  cent.)  of  yeast. 
As  potatoes  readily  pass  into  the  acetous  fermentation,  the  admixture  of  the  malt,  the 
mashing,  and  the  cooling  should  be  rapidly  performed,  while  the  utmost  cleanliness  must 
be  observed. 

The  fermentation  is  brisk,  probably  from  the  agency  of  the  albumen,  and  furnishes  a 
good  head  of  barm,  which  answers  well  for  the  bakers ;  100  pounds  of  potatoes  yield 
from  18  to  20  pounds  measure  of  spirits,  nine  elevenths  of  our  excise  proof;  or  about  16 
pounds  measure  of  proof,  =  about  If  gallons. 

It  has  been  observed  that  after  the  month  of  December  potatoes  begin  to  yield  a 
smaller  product  of  fermented  spirits;  and  when  they  have  once  sprouted  or  germinated, 
they  afford  very  little  indeed.  From  the  difficulty  of  keeping  and  transporting  potatoes, 
distillation  from  them,  even  though  our  laws  now  permit  it,  can  never  become  general  till 
some  plan  be  adopted  for  overcoming  these  disadvantages.  A  scheme  of  this  kind,  how- 
ever, has  been  successfully  practised  in  Vienna,  which  consists  in  subjecting  the  washed 
potatoes  to  strong  pressure  in  a  perforated  chest  by  a  hydraulic  or  screw  press,  whereby 
they  lose  about  three  fourths  of  their  weight,  and  may  then  be  readily  dried  into  a  white 
flour,  that  may  be  kept  for  several  years  without  injury,  and  transported  to  considerable 
distances  with  comparative  ease.  This  flour,  mixed  with  a  moderate  quantity  of  ground 
malt,  and  saccharified  by  mashing  with  water,  at  the  temperature  of  167°  F.,  becomes 
capable  of  affording  a  sweet  wort  convertible  by  fermentation  either  into  beer  or 
whiskey. 

Horse-chestnuts,  according  to  Hermstaedt,  are  an  eligible  material  for  producing  alco- 
hol, as  128  pounds  of  them  afford  100  pounds  of  meal ;  which  100  pounds  yield,  by 
S roper  treatment,  34  pounds  of  spirits,  containing  36  per  cent,  of  absolute  alcohol,  by 
Lichtor's  tables.  Barlry  to  the  extent  of  10  pounds  per  190  should  be  ground  up  witb 
them,  after  they  have  been  boiled  in  a  steam  apparatus,  not  only  for  the  purpose  oi 
softening  them,  but  freeing  them  from  their  bitter  astringent  matter.  Acorns  are  pro 
ductive  of  alcohol  by  similar  treatment. 

The  best  means  hitherto  discovered  for  depriving  bad  whiskey  of  its  nauseous  smell 
and  taste  is  to  pass  it  through  well  burned  and  coarsely  pulverized  charcoal,  distributed 
as  follows  in  a  series  of  cylindrical  casks.  Each  vessel  must  have  a  double  bottom,  the 
false  one  being  perforated  with  conical  holes,  and  placed  a  few  inches  above  the  true. 
Upon  this  perforated  board  a  layer  of  chopped  clean  straw,  one  inch  thick,  is  laid ;  and 
over  the  straw,  a  stratum  of  small  river  gravel,  the  size  of  large  peas.  This  is  to  be 
covered  with  a  pretty  thick  stratum  of  the  charcoal,  previously  freed  from  dirt  and  dust 
by  washing;  upon  which  a  piece  of  close  canvass  is  to  be  spread,  and  pressed  down  by 
a  thin  bed  of  river  sand.  The  cylinder  or  cask  should  be  filled  with  these  successive 
layers  to  within  two  inches  of  its  top,  and  it  is  then  to  be  closed  air-tight.  Immediately 
below  the  head,  a  round  orifice  is  pierced  in  the  side,  for  receiving  an  overflow  tube, 
which  is  either  screwed  rectangularly  to  another  elbow  pipe,  or  is  bent  (when  of  block 
tin)  so  as  to  enter  tight  into  an  orifice  beneath  the  false  bottom  of  the  second  cylinder  or 
cask.  In  this  way,  the  series  may  be  continued  to  any  desired  number  of  vessels;  the 
last  discharging  the  purified  spirit  into  the  store-back.  The  foul  spirit  must  be  made  to 
flow  into  the  bottom  space  of  the  first  cylinder  down  through  a  pipe  in  communication 
with  a  charging-back  placed  upon  such  an  elevated  level  as  to  give  suflScient  pressure  to 
force  the  spirits  up  through  the  series  of  filters;  the  supply-pipe  being  provided  with  a 
regulating  stop-cock.    The  spirit  may  be  filtered  downwards  through  sand  and  cloth  is 


i^i 


594 


DOCIMACY. 


its  final  passage  to  the  receiver.     It  has  been  found,  with  very  cmde  epints,  that  eight 
luceessive  cylinders  were  required  to  deprive  them  entirely  of  the  rank  flavor. 

Fig.  466  represente  one  form  of  the  worm-safe,  which  is  a  contrivance  for  permittmg 

trivance  for  permitting  the  distiller  to 
observe  and  note  at  any  period  of  the 
distillation  the  alcoholic  strength  or  the 
specific  gravity  of  his  spirits,  without 
access  to  the  still  or  the  means  of  pur* 
loining  the  product  before  it  has  paid  duty. 
The  nose-pipe  of  the  worm-tub  terminatef 
in,  and  is  firmly  cemented  to  the  side  ©f  th« 
glass  globe,  a,  from  whose  bottom  the  dis« 
charge-pipe  descends  vertically,  but  has  a 
stop-coek  upon  it,  and  a  branch  small  pip« 
h,  turned  up  parallel  to  the  former.  This 
branch  is  surmounted  with  a  glass  cylinder, 
c,  which,  when  the  stop-cock  is  opened,  getf 
filled  with  the  spirits,  and  then  receives  » 
hydrometer  to  show  the  gravity  of  the  fluid. 
The  stop-cock  mechanism  is  so  contrived, 
that  only  one  full  of  the  small  glass  eylior 
der  can  be  obtained  at  a  time. 

The  following  is  the  gross  produce  ©f 
the  exeise  duties  on  British  distilled  spirits 
for  the  United  Kingdom  annually  fron» 
1830  to  1840  inchisive  :  183 1,  5,196,.n5i.  ? 
1852, 5,163,3731. ;  1833, 5,258,572f.  j  1834^ 
&,287,G32L;  1835,  5,073,276^  j  1836,  5,. 
485,883L;  1837,5,006,697*.;  1838,  5,451,792/.;  1839,5,363,220/.;  1840,  5,208,04^. 
The  net  produce  is  very  nearly  the  same.  In  1838<,  26,486,543  railliens  of  gallons  paid 
duty;  in  1839,  25,190,843  ;  and  in  1840,  21,859,337.     Sec  Rrm,  SrrRiTS,  and  Sriii- 

DIVIDIVI,   is    an    indigenous    production    ©f   Jaraaroa.      Mr.    Rootsey  obtaraed 
a  mean   prod'uce  of  6-625  gra.  of  leather  from  60-  grs.  of  <?rvidivT,  while  the  earae 
quantity  of  the  best  Aleppo  galls  yielded  only  »  mean  pro^ee  of  4ft25.     Bence  it 
Jppears  from  Sir  Humphry  Davy's  estimate,   th««  the  6^  grs;  of  dirxdm  eofltam 
i'Oilb  grs.  or  5079  per  cent,  of  tannin  and  60  grs.  of  galls,  on  2127»4  grains,  or  S4& 
per  cent    Sixty  grs.  of  oak  bark  yielded  only  1-75  grains  of  leather  ;  whence  it  fo*low» 
Uiftt  It  contains  but  0*805  of  a  grain  of  tannin  to  the  drachm,  or  not  more  than  1-34166. 
DOCIMACY,  from   the  Greek    AoKifia^u,   I   prove    (JDocir.natie,  Ft,;   Prohierkwutf 
Germ.);   is  the  art   by  which  the  nature  and  proportions  of  an  ore  are  determine*. 
This  analytical  examination  was  originally  conducted  inr  the  dry  way,  the  metal  bein| 
extracted  from  its  mineralizers,  by  means  of  heat  and  certarrw  fluxes.    But  this  method 
was  eventually  found  to  be  insufficient  and  even  fallacious,  especiaHy  when  voKitilf 
metals  were  in  question,  or  when  the  fluxes  could  absorb  them.     The  latter  eircnm. 
stance  became  a  very  serious  evil,  whenever  the  object  was  to  appreciate  an  ore  that  waf 
to  be  worked  at  great  expense.     Bergmann  first  demonstrated,  m  an  elaborate  disser. 
tation   that  the  humid  analysis  was  much  to  be  preferred  ;    and=  since  his  time  the  dry 
way    has  been   consecrated   chiefly  to  the   direction  of  metalhirfftc   operations,  or,  at 
least,  it  has  been  employed  merely  in   concert  with  the  hm»id,  i»  trial*  »p©n  the 

After  discovering  an  ore  of  some  valuable  metal,  it  is  esserrtial  to  ascertain  if  it» 
quantity  and  state  of  combination  will  justify  an  adventurer  in  working  the  mine,  and 
smelting  its  products.  The  metal  is  rarely  found  in  a  condition  approachmg  to  purrtyj 
it  is  oAen  disseminated  in  a  mineralizing  gangiie  far  more  bulky  than  itself;  and  more 
frequently  still  it  is  combined  with  simple  non-metallic  substances,  such  as  sulphur, 
carbon,  chlorine,  oxygen,  and  acids,  more  or  less  difficult  to  get  rid  of.  In  these 
compound  states  its  distinctive  characters  are  so  altered,  that  it  is  not  an  easy  task 
either  to  recognise  its  nature,  or  to  decide  if  it  can  be  smelted  with  advantage.  The 
assayer,  without  neglecting  any  of  the  external  characters  of  the  ore,  seeks  to  penetrate, 
80  to  speak,  into  its  interior;  he  triturates  it  to  an  impalpable  powder,  and  then  subjects 
it  to  the  decomposing  action  of  powerful  chemical  reagents ;  sometimes  with  the  aid  of 
alkalis  or  salts  appropriate  to  its  nature,  he  employs  the  dry  way  by  fire  alone;  at 
others  he  calls  in  the  solvent  power  of  acids  with  a  digesting  heat;  happy,  if  after  a 
series 'of  labors,  long,  varied,  and  intricate,  he  shall  finally  succeed  in  separating  a 
notable  proportion  of  one  or  more  metals  either  in  a  pure  state,  or  in  a  form  of  com- 
bination such  that  from  the  amount  of  this  known  compound,  he  can  infer,  with 
precision  the  quantity  of  fine  metal,  and  thereby  the  probable  value  of  the  mine.  The 
blow-pipe   skilfully   applied   aflfords  ready  indications  of  the  nature  of  the  metallic 


DONARIUM. 


595 


constituents,  and  is  therefore  usually  the  preliminary  test.  The  separation  of  the 
several  constituents  of  the  ore  can  be  effected,  however,  only  by  a  chemist,  who  joins 
to  the  most  extensive  knowledge  of  the  habitudes  of  mineral  substances,  much  expe- 
rience, sagacity,  and  precision,  in  the  conduct  of  analytical  operationa  Under  the 
individual  metals,  as  also  in  the  articles  Metallurgy,  Mines,  and  Ores,  I  have  endeav- 
ored to  present  such  a  copious  and  correct  detail  of  docismastic  processes,  as  will  serve  to 
guide  the  intelligent  student  through  this  most  mysterious  labyrinth  of  nature  and  art 

DONARIUM,  a  recently/  discovered  metal. — Dr.  Bergemann  received  through  Mr. 
Krantz  a  mineral  from  Brerig  in  Norwav,  which  is  found  in  the  same  zircon-syenite 
that  contains  wohlerite  and  eukolite,  and  he  discovered  in  it  the  oxide  of  a  new  metal 
combined  with  silicic  acid.  This  metal  he  calls  Donarium,  after  the  god  Donar,  and 
he  assigns  to  it  the  symbol  Do. 

The  silicate  of  the  oxide  of  donarium,  D02  O3  Si  Os  -f2  H  0,  is  yellowish  red,  in  some 
fragments  passing  into  brown,  in  others  into  yellow;  when  scratched  or  powdered,  it 
is  light  orange.  In  thin  films  it  is  almost  transparent,  the  thicker  ones  translucid. 
Some  pieces  have  a  distinctly  laminated  structure,  in  others  the  fracture  is  more  flat,  or 
conchoidal.    Its  hardness  is  between  that  of  fluor  spar  and  apatite;  its  spec,  gra v.i— 5-397. 

Small  films  heated  in  a  platina  spoon  break  .'own  into  a  dark  brown  mass,  which 
reassumes  an  orange  color  when  cold :  the  larger  pieces  lose  their  transparency.  By 
heating  it  in  a  glass  tube,  watery  vapor  is  driven  off".  Fragments  held  by  the  platina 
forceps  in  the  flame  of  a  spirit  lamp  decrepitate.  Heated  by  the  blowpipe  on  charcoal, 
it  does  not  melt,  a  slight  vitrification  being  sometimes  observed  on  the  edges,  perhaps 
in  con8e<juence  of  the  intermixture  of  some  foreign  substance.  Fused  with  soda, -the 
6ilicio  acid  is  dissolved.  The  other  constituents  are  seen  in  the  non-transparent  mass, 
by  the  help  of  a  glass,  as  small  yellow  particles.  Borax  yields  a  yellow  bead,  which 
is  colorless  when  cold.  The  phosphates  produce  in  the  external  part  of  the  flame  a 
reddish  glass,  which  is  colorless  when  cold ;  in  the  inner  part  of  the  flame  the  bead 
becomes  yellow,  and  when  cold  is  colorless. 

The  mineral  is  readily  and  completely  decomposed  by  acids,  and  yields  when  treated 
by  hydrochloric  acid  a  clear  and  transparent  gelatinous  matter.  At  the  same  time 
(Bome  carbonic  acid  is  evolved.  The  color  of  the  solution  is  deep  yellow,  like  that  of  a 
concentrated  solution  of  iron.  The  mineral  is  also  affected  by  diluted  acids,  even  by 
tartaric  acid.  After  having  been  exposed  to  a  strong  heat,  the  essential  parts  of  the 
mineral  are  no  longer  acted  upon  even  by  concentrated  acids. 

The  analysis  showed  the  presence  of  lime,  water,  and  the  new  oxide,  also  some  traces 
of  magnesia,  manganese,  carbonate  of  soda,  and  iron. 

The  oxide  of  donarium  belongs  to  the  class  of  earthy  bodies,  and  ranks  next  to 
zirconia  and  yttria.  The  hydrate,  which  is  thrown  down  by  ammonia  of  a  beautiful 
white  color,  becomes  yellow,  and  at  last  yellowish  red,  losing  its  hydrate  water  in  the 
air.  By  heat  the  latter  is  completely  removed,  and  the  oxide,  which  is  insoluble  in 
muriatic  acid,  can  be  perfectly  deprived  by  this  acid  of  the  contained  iron.  The  analysis 
showed  the  constituents  to  be : — 


Silicic  acid  -  -  . 

Oxide  of  donarium 

Carbonate  of  lime 

Oxide  of  iron  ... 

Magnesia  and  oxide  of  manganese 

Potash  and  a  little  soda    - 

Water        .... 


17-696 
71-247 
4-042 
0-310 
0-214 
0-303 
6-900 

100-741 


The  metal  is  obtained  as  a  black  powder,  by  treating  the  oxide  with  potassium. 
If  the  alkaline  solution  be  directly  poured  off  and  the  powder  washed  with  water, 
it  can  be  kept  for  from  24  to  36  hours  under  water  without  alteration;  but  if  it 
remains  under  hot  water,  a  yellowish  gray  mass  is  gradually  formed,  in  consequence  of 
oxidation.  The  black  metallic  powder  forms  heavy  flocculi,  which  soon  conglomerate 
and  are  easily  separated  by  filtration.  When  in  the  dried  state  they  assume  a  metallic 
lustre  when  rubbed  with  an  agate ;  and  then  can  be  preserved  in  this  condition  for 
several  hours,  even  in  a  damp  atmosphere,  without  developing  any  smell.  The  specific 
gravity  is  nearly —7-35.  The  powder  thrown  into  a  flame  burns  with  a  reddish  light, 
and  yields  the  red  oxide;  so  also,  if  the  black  powder  be  heated  in  a  platina  spoon,  it 
burns,  and  moreover  appears  to  glow,  but  only  transitorily.  Neither  cold  nor  boiling 
muriatic  acid  affects  the  metal ;  nitric  acid  acts  not  when  cold,  and  but  slowly  when 
heated;  nitro-rauriatic  acid  readily  produces  the  red  oxide,  of  which  a  small  portion 
is  dissolved;  by  the  application  of  a  few  drops  of  sulphuric  acid  a  sulphate  is  formed, 
while  at  the  same  time  the  smell  of  sulphurous  acid  is  perceived.    The  grayish  yellow 


-i    i 


596 


DRYING  HOUSE. 


substance  produced  bj  potash  water,  quickly  forms,  when  heated  by  itself  or  moistened 
with  nitric  acid,  the  red  oxide.  This  powder  also,  when  thrown  into  the  flame  of  a 
spirit  lamp,  glows. 

Hydrated  Oxide  of  Donarium.— The  precipitate  produced  by  ammonia  from  the 
muriatic  solution  of  the  mineral  is,  by  long  digestion  with  sulphuric  acid,  converted 
into  sulphate  of  the  oxide  of  donarium,  and  from  this  the  hydrated  oxide  is  precipitated 
by  ammonia.  The  voluminous  precipitate,  dried  at  ordinary  temperatures,  forms 
yellow  gummy  masses,  the  powder  of  which  is  reddish.  In  this  condition  the  substance 
represents  the  pure  hydrated  oxide,  which,  like  oxide  of  iron,  probably  combines  with 
different  proportions  of  water.  The  water  is  expelled  by  a  slight  increase  of  tem- 
perature. The  hydrate  is  dissolved  by  all  acids  at  common  temperatures,  and  more  so 
when  heated.     If  muriatic  acid  be  employed,  no  chlorine  is  developed. 

Oxide  of  Donarium  is  obtained  by  heating  the  hydrate  to  redness.  Its  sp.  erav,  is 
6-576,  color  deep  red;  its  form  heavy  glittering  scales.  Finely  powdered  it  is  orange; 
darker  when  strongly  heated,  and  lighter  again  when  cold.  Muriatic  acid,  nitric  acid, 
aqua  regia,  and  even  fluoric  acid,  have  no  effect  upon  the  oxide  which  has  been  heated 
to  redness.  By  the  continued  action  of  concentrated  sulphuric  acid  it  is  rendered 
soluble,  if  it  be  afterward  mixed  with  much  water.  If  the  oxide,  however,  be  exposed 
only  to  that  temperature  which  expels  the  water  from  the  hydrate,  it  is  slightly  acted 
upon  by  muriatic  acid,  without  the  development  of  chlorine. 

DORNOCK  is  a  species  of  figured  linen  of  stout  fabric,  which  derives  its  name 
from  a  town  m  Scotland,  where  it  was  first  manufactured  for  table-cloths.  It  is  the 
most  simple  in  pattern  of  all  the  varieties  of  the  diaper  or  damask  style,  and  therefore 
the  goods  are  usually  of  coarse  quality  for  common  household  wear.  It  receives  the 
figure  by  reversing  the  flushing  of  the  warp  and  woof  at  certain  intervals,  so  as  to 
form  squares,  or  oblong  rectangles  upon  the  cloth.  The  most  simple  of  these  is  a  suc- 
cession of  alternate  squares,  forming  an  imitation  of  a  checker  board  or  mosaic  work. 
The  coarsest  kinds  are  generally  woven  as  tweels  of  three  leaves,  where  every  thread 
floats  over  two,  and  is  intersected  by  the  third  in  succession.  Some  of  the  finer  are 
tweels  of  four  or  five  leaves,  but  few  of  more ;  for  the  six  or  seven  leaf  tweels  are  sel- 
dom or  never  used,  and  the  eight  leaf  tweel  is  confined  almost  exclusively  to  damask. 
See  Textile  Fabric. 

DRAGON'S  BLOOD,  {Sangdraeon,  Fr. ;  Drachenhlut  Germ.)  is  a  resinous  substance, 
which  comes  to  us  sometimes  in  small  balls  about  the  size  of  a  pigeon's  egg,  sometime* 
in  rods  like  the  finger,  and  sometimes  like  irregular  cakes.  Its  color,  in  lump,  is  dark 
brown  red;  in  powder,  bright  red;  friable;  of  a  shining  fracture;  sp.  grav.  1-196. 
It  contains  a  little  benzoic  acid,  is  insoluble  in  water,  but  dissolves  readily  in  alcohol, 
ether,  and  oils.  It  is  brought  from  the  East  Indies,  Africa,  South  America,  as  the 
produce  of  several  trees,  the  Draccena  Draco,  the  Pterocarpus  santalinus,  Pteroearpu* 
Draco  and  the  Calamus  Rotang. 

Dragon's  blood  is  used  chiefly  for  tinging  spirit  and  turpentine  varnishes,  for 
preparing  gold  lacquer,  for  tooth  tinctures  and  powders,  for  staining  marble,  Ac 
According  to  Herbenger,  it  consists  of  907  parts  of  red  resin,  2  of  fat  oil,  3  of  benzoic 
acid,  1-6  of  oxalate,  and  3-7  of  phosphate  of  lime. 

DRUGGET  is  a  coarse,  but  rather  slight,  woollen  fabric,  used  for  covering  carpets, 
and  as  an  article  Of  clothing  by  females  of  the  poorer  classes.  It  is  now-a-days  nearly 
superseded  by  coarse  cotton  goods. 

DRYING  HOUSK  An  apartment  fitted  up  in  a  peculiar  manner  for  drying 
calicoes  and  other  textile  fabrics.  Mr.  Southworth,  of  Sharpies,  a  Lancashire  bleacher, 
obtained  a  patent,  in  1823,  for  the  following  ingenious  arrangement,  which  has  been 
since  generally  adopted,  with  certain  modifications,  in  most  of  our  extensive  bleaching 
and  printing  works.  Fig.  467  is  a  section  of  the  drying-house,  where  a  is  a  furnace 
and  boiler  for  the  purpose  of  generating  steam ;  it  is  furnished  with  a  safety  valve  in 
the  tube  6,  at  top,  and  from  this  tube  the  steam  main  c  passes  down  to  the  floor  of  the 
basement  story.  From  this  main,  a  series  of  steam-pipes,  as  d  d,  extend  over  the  surface 
of  the  floor,  and  from  them  heat  is  intended  to  be  diffused  for  the  purpose  of  warming 
the  drymg-house.  r     r  o 

Along  the  middle  of  the  building  a  strong  beam  of  timber  e  e  extends,  and  is  sup- 
ported by  cast-iron  pillars ;  from  this  beam  to  bearings  on  the  side  walls,  a  series  of 
rails  are  carried  in  a  cross  direction,  over  which  rails  the  wet  cloth  is  to  be  hung  in 
folds,  and  the  steam  or  evaporation  emitted  in  drying  is  allowed  to  escape  through 
apertures  or  ventilators  in  the  roof. 

The  mode  in  which  the  cloth  is  delivered  on  to  the  rails,  on  either  side  of  the  beam, 
will  be  best  understood  by  reference  to  the  delivering  carriage,  which  is  shown  with 
its  rollers  partly  in  section. 

The  wet  cloth  is  first  to  be  coiled  upon  a  roller,  and  then  placed  in  the  carriage,  as 
•t/,  with  its  pivots  bearing  upon  inclined  planes.    The  carriage  is  to  be  placed  at  the 


DRYING  MACHINE. 


597 


commencement  of  the  rails,  running  upon  the  middle  beam,  and  also  upon  the  side- 
bearings  or  railways  extending  along  the  side  walls  of  the  building,  parallel  to  and 
upon  a  level  with  the  same  beam.     It  is  made  to  travel  by  means  of  an  endless  band 


passing  over  two  riggers,  g  and  A,  in  fg.  467,  and  over  pulleys  and  a  band-wheel 
attached  t»  the  carnage,  as  will  be  explained.  The  rigger  g,  which  moves  this  endless 
band,  is  axjtuated  by  bevel  geer,  seen  at  t,  which  is  put  in  motion  by  a  pinion  at  the  end 
of  a  revolving  shaft  leading  from  a  steam  engine. 

In  the  same  ^.,  kk'\%  the  endless  band  j^assing  over  a  pulley  under  the  band-wheel 
and  oyer  the  pulley  «,  by  which  it  will  be  perceived  that  the  traversing  of  the  band,  as 
described,  would  cause  these  pulleys  and  wheels  to  revolve.  On  the  axle  of  the  band- 
wheel  m,  there  is  a  drum  against  which  the  roll  of  wet  cloth  /  presses,  and  as  this 
drum  revolves,  Uie  roll  of  wet  cloth  ifi^  by  its  friction,  made  to  turn  in  a  contrary  di- 
rection, and  to  deliver  off  tlie  cloth  on  to  the  periphery  of  the  drum,  whence  it 
passes  over  a  roller  and  descends  to  the  rails.  Upon  the  end  of  the  axle  of  the 
band  wheel  >«,  tliere  is  a  pinion  which  takes  into  the  teeth  of  the  large  wheel  and 
upon  tlie  axle  of  this  large  wheel  there  is  a  pinion  that  actuates  the  intermediate  wheel 
which  turns  another  toothed  wheel  This  last-mentioned  toothed  wheel  takes  into 
cogs  upon  the  side  railway,  and  hence,  as  the  train  of  wheels  moves  round,  the  carriage 
to  which  the  wheels  are  attached  is  slowly  impelled  forward. 

As  soon  a3  the  wheels  begin  to  move,  and  the  carriage  to  advance,  the  wet  cloth 
begins  to  uncoil,  and  to  pass  down  over  the  first  roller;  a  small  roller  attached  to  the 
carnage,  as  it  passes  over  the  rails  in  succession,  holds  the  cloth  against  each  rail  for  a 
short  space  of  tinie,  and  prevente  it  from  slipping,  by  which  means  the  cloth  descends 
in  folds  or  loops  between  the  rails,  and  is  thereby  made  to  hang  in  a  series  of  folds  or 
loops,  as  shown  m  the  figure. 

It  will  be  perceived  that  as  the  pivots  of  the  cloth  roller/  bear  upon  inclined  planes, 
the  roller  will  continually  slide  down  as  the  cloth  diminishes  in  bulk,  keeping  in  con- 
tact  with  the  drum,  and  delivering  the  cloth  from  the  roller  on  to  the  several  rails,  as 
described.  ^ 

In  order  to  stop  the  carriage  in  any  part  of  its  course,  or  to  adjust  any  of  the  folds  of 
the  cloth,  a  man  is  usually  placed  upon  the  platform  travelling  with  the  carriage, 
over  which  he  has  perfect  command.  This  apparatus  may  be  also  employed  for  takmg 
the  cloth  when  dried  off  the  rails;  in  which  case  the  carriage  must  be  made  to  travel 
backward,  and  by  first  gmding  the  end  of  the  cloth  on  to  the  roller/  and  then  putting 
the  wheels  in  a  retrograde  motion,  the  cloth  will  be  progressively  coiled  upon  the  roU^ 
/,  in  a  similar  way  to  that  by  which  it  was  uncoiled. 

DRYING  MACHINE  (CENTRIFUGAL).  {Hydro-extracteur ;  Machh^  d.  essorer, 
Fr.)— By  this  contnvance,  Peutzoldt  was  enabled  to  deprive  all  kinds  of  wet  clothes 
in  a  few  minutes  of  their  moisture,  without  compression  or  heat  Kelly,  a  dyer. 
»nd  Alliott,  a  bleecher,  have  since  obtained  a  patent  for  the  above  machine  with 
improvementa  i^^^.  468  represents  a  partial  section  of  the  machine,  a,  a,  is  the 
frame;  b,  the  vertical  shaft  turning  in  the  step  a,  fixed  on  the  bridge  b.  This  shaft 
bears  on  ite  upper  part  a  friction  cone  c,  from  which  it  receives  its  movement  of  roUtion 


--^  % 


598 


DRYING  MACHINE. 


DUNGING. 


599 


i; ') 


'•I 


as  will  be  shown  presently;  c  is  a  drum  containing  two  concentric  compartments  d e^ 
of  the  form  represented  in  the  figure ;  this  drnm  moves  freely  upon  the  shaft  b,  and 

468. 


rests  when  it  is  not  in  motion  upon  two  conical  projections  /,  g,  which  form  a 
part  of  the  shaft.  These  two  compartments  are  each  composed  mainly  of  metal, 
and  their  sides  consist  of  tinned  iron  wire  coiled  circularly  at  very  small  distances 
from  each  other,  and  soldered  together  crosswise  by  small  slips  of  metal.  The  top, 
which  covers  the  inner  compartment  d,  is  secured  by  bolts  and  screws  to  a  circle  of 
iron  which  retains  the  wire  sides  of  the  same  metal,  but  that  which  serves  as  a  cover 
to  the  little  compartment  e,  in  which  alone  the  goods  are  placed,  is  disposed  so  that 
it  may  be  removed  with  ease,  when  these  are  to  be  introduced  or  withdrawn.  It  is 
furnished  with  an  outer  and  inner  border,  disposed  so  that  when  the  top  is  fixed  the 
inner  border  presses  upon  the  convex  circumference  of  the  central  compartment,  while 
the  exterior  border  falls  oatside  of  the  edges  of  the  other  compartment.  "While  the 
machine  is  at  work,  the  second  plate  is  maintained  in  its  place  by  pins  or  bolts,  not 
shown  in  the  figure. 

The  sides  of  the  outer  compartment  d,  are  connected  with  the  bottom  by  means  of  • 
prolongation  of  cross  bauds  of  metal  which  unite  the  wires  and  are  riveted  or  soldered 
to  the  two  outer  plates.  The  wires  of  the  interior  compartment  are  attached  by  an 
iron  hoop,  to  which  they  are  riveted  and  soldered,  and  are  united  to  the  bottom  plate 
by  means  of  a  rim  upon  this  plate ;  a  rim  somewhat  flattened  upon  the  sides  which  are 
nveted  and  soldered. 

D,  is  a  regulator  suspended  in  the  inner  compartment  d,  and  whose  two  branches  A,  A, 
are  loaded.  These  two  branches  having  room  to  play  around  the  bolts  which  serve  as 
points  of  attachment,  and  which  are  fixed  to  the  upper  plate,  terminate  in  kneed  bran- 
ches whose  extremities  rest  upon  a  rope  ff,  which  projects  from  the  shaft,  i:,  is  an  ex- 
terior envelope  secured  to  the  frame  a,  a.  It  encloses  the  whole  drum  except  at  top, 
and  serves  to  catch  the  water  thrown  out  of  the  goods.  At  y  there  is  a  stopcock  for 
the  dischai^e  of  this  water,  and  the  bottom  contains  besides  the  end  of  a  pipe  by  which 
hot  air  is  introduced. 

The  vertical  shaft  b  receives  a  movement  of  rotation  and  carries  with  it  the  drum. 
The  more  rapid  this  movement  is  the  more  does  the  centrifugal  force  tend  to  expel 
the  water  contained  in  the  clothes  or  yarn  to  be  dried.  But  as  this  force  might  also 
displace  the  central  shaft,  if  the  weight  was  not  rightly  distributed  in  the  drum,  and 
cause  the  dislocation  of  the  machine  when  the  great  velocity  requisite  for  quick 
drying  is  given  to  it,  the  regulator  d  is  tested  to  prevent  accident.  The  branches 
of  this  regulator  spread  wider  the  more  the  velocity  is  increased,  and  raise  conse- 
quently the  drum  c  above  the  conical  enlargements,  which  permits  the  drum  to  be 
somewhat  misplaced  and  to  rectify  its  position  conformably  to  the  inequalities  of  its 
load,  so  that  its  centre  of  gravity  may  always  coincide  with  its  centre  of  rotation.  The 
drum  is  connected  with  the  shaft  as  is  shown  in  z,  leaving  it  free  to  take  the  requisite 
adjustment.  To  hinder  it  from  rising  too  suddenly,  a  spiral  spring  k  is  fixed  over  the 
shaft  immediately  above  the  conical  enlargement  or.  In  order  to  maintain  the  equi- 
librium more  certainly,  the  apparatus  is  surrounded  with  a  hollow  crown  f,  half  filled 
with  water,  and  if  during  the  revolution  of  the  machine  the  weight  of  the  goods 
predominates  on  one  side,  that  of  the  water  which  accumulates  on  the  other  side  serves 
the  more  to  counterbalance  it     The  effect  of  this  crown  may  be  increased  by  dividing  it 


into  two  compartments  or  more,  o,  is  a  lai^e  pipe  by  which  steam  or  hot  air  is  intro- 
duced into  the  belly  of  the  drum,  which  is  pierced  in  this  place  with  a  great  number  of 
small  holes  to  receive  it 

The  rotary  movement  is  transmitted  to  the  drum  in  the  following  way. 

I  is  a  conical  disc  mounted  upon  the  extremity  of  a  shaft  which  actuates  the  cone  o 
and  the  shaft  b  by  means  of  friction ;  l  is  a  cone  fixed  upon  the  extremity  of  the  shaft 
K  L  "is  another  cone  of  the  same  dimension,  but  whose  base  fronts  the  top  of  the  other 
and  which  is  placed  on  the  shaft  k"  commanded  by  the  prime  mover,  m  is  the  belt 
which  embraces  the  two  cones,  and  whose  lateral  displacement^  effected  by  means  of  a 
fork,  permits  the  velocity  of  the  machine  to  be  regulated  at  pleasure,  n  is  the  pulley 
which  directly  receives  the  movement  In  place  of  a  single  friction  disc  i,  another  may  be 
employed,  if  judged  necessary,  and  placed  between  the  two,  an  additional  friction  pole  in 
order  better  to  equalize  the  friction.  In  this  case  the  disc  and  additional  cone  should 
turn  freely  upon  their  own  shafts.  We  may  also  adopt  another  arrangement  for  the 
bottom  of  the  vertical  shaft  The  shaft  immediately  above  the  step  is  surrounded  br 
a  loose  rim,  around  which  a  certain  quantity  of  lead  shot,  or  other  granular  matter,  is 
contained  in  the  rim  in  the  box  which  serves  for  the  step.  The  top  of  this  box  is 
pierced  with  an  opening,  into  which,  when  the  machine  is  at  rest  a  cord  connected  with 
the  shaft  sinks,  controlled  by  the  shaft  ai<l  when  the  drum  is  raised  by  the  action  of  the 
regulator  d,  this  cord  quits  its  place,  which  allows  the  shaft  to  displace  the  shot  a  little, 
and  to  take  a  position  conformably  to  the  point  of  the  centre  of  gravity. 

But  after  all  great  attention  should  be  paid  to  the  proper  working  of  the  machine. 

DUCTILITY  (Sireckbarkeiff  Germ.)  is  the  property  of  being  drawn  out  in  length 
without  breaking,  possessed  in  a  pre-eminent  degree  by  go.C  and  silver,  as  also  by  many 
other  metals,  by  glass  in  the  liquid  state,  and  by  many  semifluid  resinous  and  gummy 
substances.  The  spider  and  the  silk-worm  exhibit  the  finest  natural  wtercise  of  ductility 
upon  the  peculiar  viscid  secretions  from  which  they  spin  their  threads.  When  a  bodj 
can  be  readily  extended  in  all  directions  under  the  hammer,  it  is  said  to  be  malleable,  and 
when  into  fillets  under  the  rolling  press,  it  is  said  to  be  laminable. 

TabU  of  the  ductility  and  malleability  of  Metals, 


Metals  ductile  and 

Brittle  metals 

Mntals  in  the  order 

Metala  in  the  order  of 

malleable  in  alphabetical 

in 

of  their  wire-drawing' 

their  laminable 

order. 

alphabetical  order. 

ductility. 

ductility. 

Cadmium. 

Antimony. 

Gold. 

Gold. 

Copper. 

Arsenic. 

Silver. 

Silver. 

Gold. 

Bismuth. 

Platinum. 

Copper. 

Iron, 

Cerium.  1 

Iron. 

Tin. 

Iridium. 

Chromium. 

Copper. 

Platinum. 

Lead. 

Cobalt. 

Zinc. 

Lead. 

Magnesium. 

Columbium. 

Tin. 

Zinc. 

Mercury. 

Iridium. 

Lead. 

Iron. 

Nickel. 

Manganese. 

Nickel. 

Nickel. 

Osmium. 

Molybdenum. 

Palladium.  ? 

Palladium.  ? 

Palladium. 

Osmium. 

Cadmium.  ? 

Cadmium.  1 

Platinum. 

Rhodium. 

Potassium. 

Tellurium. 

Silver. 

Titanium. 

Sodium. 

Tungsten. 

Tin. 

Uranium. 

» 

Zinc. 

I 


There  appears  to  be,  therefore,  a  real  difference  between  ductility  and  malleability; 
for  the  metals  which  draw  into  the  finest  wire  are  not  those  which  afford  the  thinnest 
leaves  under  the  hammer  or  in  the  rolling  press.  Of  this  fact  iron  affords  a  eood  illus- 
tration. Among  the  metals  permanent  in  the  air,  17  are  ductile  and  16  are  brittle.  But 
the  most  ductile  cannot  be  wire-drawn  or  laminated  to  any  considerable  extent  without 
being  annealed  from  time  to  time  during  the  progress  of  the  extension,  or  rather  the 
sliding  of  the  particles  alongside  of  each  other,  so  as  to  loosen  their  lateral  cohesion. 

DUNGING,  in  calico-printing,  is  the  application  of  a  bath  of  cowdung,  diffused 
through  hot  water,  to  cotton  goods  in  a  particular  stase  of  the  manufacture.  Dunging 
and  scouring  are  commonly  alternated,  and  are  two  of  the  most  important  steps  in  the 
process.     The  operation  of  dunging  has  for  its  objects  : — 

1.  To  determine  the  entire  combination  of  the  aluminous  sub-salts  with  the  stufis,  by 


600 


DUNGING. 


DYEING. 


601 


separating  almost  all  the  acetic  acid  which  was  not  volatilised  in  the  stove-drying  of  the 
mordant. 

2.  To  dissolve  and  carry  off  from  the  cloth  a  portion  of  the  thickening  matters. 

3.  To  separate  from  the  cloth  the  part  of  the  mordant  that  is  uncombined^  and  merely 
mixed  mechanically  with  the  gum  or  starch. 

4.  To  prevent,  by  the  peculiar  action  of  the  dung,  the  uncombined  mordant,  as  well  as 
the  acetic  acid  with  which  the  bath  is  apt  to  get  loaded,  from  affecting  the  blank  parts 
of  the  cloth,  or  being  injurious  to  the  mordant. 

The  aluminous  base  or  mordant  on  the  cloth,  more  or  less  neutralized  by  the  dunging, 
is  next  subjected  to  the  dash-wheel  or  fulling  mill,  where  by  the  stream  of  water  the 
remainder  of  the  thickening  and  other  impurities  are  washed  away. 

No  very  exact  analysis  has  been  made  of  cowdung.  Morin's,  which  is  the  most  receaC 
and  elaborate,  is  as  fo'llows ; — 

Water       -        -        .  -        .        -    70-00 

Vegetable  fibre 24-08 

Green  resin  and  fat  acids  -        -        -        -       1-52 

Undecomposed  biliary  matter         -        -  0-60 

Peculiar  extractive  matter  (btHmline)  -        -       1*60 
Albumen       ------  0-40 

Biliary  resin  -  -        -        -        -      1*80 

According  to  M.  Koechlin's  practical  knowledge  on  the  great  scale,  it  consists  of  • 
moist  fibrous  vegetable  substance,  which  is  animalized,  and  forms  about  one  tenth  of  its 
weight ;  2.  of  albumen  ;  3.  of  animal  mucus ;  4.  of  a  substance  similar  to  bile ;  5.  of 
muriate  of  soda,  muriate  and  acetate  of  ammonia,  phosphate  of  lime  and  other  salts;  6. 
of  benzoin  or  musk. 

Probably  the  hot  water  in  which  the  calico-printer  diffuses  the  dung  exerts  a  powerful 
solvent  action,  and  in  proportion  as  the  uncombined  mordant  floats  in  the  bath  it  is  pre- 
cipitated by  the  albumen,  the  animal  mucus,  and  the  ammoniacal  salts;  but  there  is  rea- 
son to  think  that  the  fibrous  matter  in  part  animalized  or  covered  with  animal  matter, 
plays  here  the  principal  part ;  for  the  great  affinity  of  this  substance  for  the  aluminous 
salts  is  well  known. 

All  practical  men  are  aware  that  the  afl^nity  of  cotton  for  alumina  is  increased  by 
its  combination  with  oil  or  animal  substances,  to  such  a  degree  as  to  take  it  from  the 
dung  bath ;  which  would  not  be  possible  without  this  combination.  It  would  therefore 
appear  that  the  principal  function  of  dunging  is  to  hinder  the  uncombined  mordant, 
diffused  in  the  dung  bath,  from  attaching  itself  to  the  unmordanted  portion  of  the 
cloth,  as  already  observed  ;  for  if  we  merely  wished  to  abstract  the  thickening  stuffs,  or 
to  complete  by  the  removal  of  acetic  acid  the  combination  of  the  aluminous  base  with 
the  goods,  dung  would  not  be  required,  for  hot  water  would  suffice.  In  fact,  we  may 
observe,  that  in  such  cases  the  first  pieces  passed  through  the  boiler  are  fit  for  dyeing ; 
but  when  a  certain  number  have  been  passed  through,  the  mordant  now  dissolved  in  the 
water  is  attracted  to  the  white  portions  of  the  cloth,  while  the  free  acid  impoverishes 
the  mordanted  parts,  so  that  they  cannot  afford  good  dyes,  and  the  blank  spaces  are 
tarnished. 

The  cowdung  may  be  in  some  measure  replaced  by  bran,  but  not  with  perfect  success. 
The  former  both  answers  the  purpose  better  and  is  cheaper.  The  bran  is  only  preferred 
for  the  most  delicate  yellows,  for  cochineal  pinks  and  lilachs,  to  which  the  dung  may 
sometimes  impart  a  greenish  cast.  It  is  to  be  presumed  that  the  action  of  the  bran  in 
this  process  has  much  analogy  with  that  of  the  dung,  and  that  the  ligneous  fibre  is  the 
3Jost  active  constituent ;  with  which  the  gluten  and  mucilage  co-operate,  no  doubt,  in 
seizing  the  aluminous  salts. 

It  seems  to  be  ascertained  that  the  mordant  applied  to  the  cloth  does  not  combine  en- 
tirely with  it  during  the  drying;  that  this  combination  is  more  or  less  perfect  according 
to  the  strength  of  the  mordants,  and  the  circumstances  of  the  dr)'ing  ;  that  the  operation 
of  dungin?,  or  passing  through  hot  water,  completes  the  combination  of  the  cloth  with 
the  aluminous  base  now  insoluble  in  water;  that  this  base  may  still  contain  a  very  mi- 
nute quantity  of  acetic  acid  or  sulphate  of  alumina ;  that  a  long  ebullition  in  water 
impoverishes  the  mordant  but  a  little;  and  that  even  then  the  liquid  does  not  contain  an} 
perceptible  quantity  of  acetate  or  subsulphate  of  alumina. 

The  manner  of  immersing  the  goods,  or  passing  them  through  the  dnng  bath,  is  an 
important  circumstance.  They  should  be  properly  extended  and  free  from  folds,  w^ich 
is  secured  by  a  series  of  cylinders. 

The  cistern  is  from  10  to  12  feet  long,  4|  feet  wide,  and  6  or  8  feet  deep.  The 
piece  passes  alternately  over  the  upper  rollers  and  under  rollers  near  the  bottom. 
There  are  two  main  squeezing  rollers  at  one  end,  which  draw  the  cloth  through  between 
them.    Whenever  the  goods  come  out  of  the  bath  they  are  put  into  the  dash-wheeL 


The  immersion  should  take  place  as  fast  as  possible,  for  the  Jioment  the  hot  water  pene- 
trates the  mordanted  cloth,  the  acetic  acid  quits  it ;  and,  therefore,  if  the  immersion  was 
made  slowly  or  one  ply  after  another,  the  acid  as  well  as  the  uncombined  mordant  become 
free,  would  spread  their  influence,  and  would  have  time  to  dissolve  the  aluminous  sub- 
salts  now  combined  with  the  cloth ;  whence  inequalities  and  impoverishment  of  the  colorft 
would  ensue. 

It  is  difficult  to  determine  the  number  of  pieces  which  may  be  passed  through  a  given 
luantity  of  dung  and  water.  This  depends  upon  the  state  of  the  mordants,  whether 
they  are  strong  or  acid,  and  on  the  quantity  of  the  surface  covered  with  the  figures. 
The  number  varies  usually  from  20  to  60  pieces,  for  from  240  to  300  gallons  of  water 
and  6  gallons  of  dung.  The  time  of  the  immersion  varies  with  the  concentration  of  the 
mordants,  and  the  nature  of  their  thickening.  The  temperature  must  be  regulated  by 
the  same  circumstances ;  for  starch  or  flour  paste  a  much  warmer  bath  is  needed  than 
for  gum.  The  heal  varies  usually  from  130°  to  212*  P,  When  the  printing  is  heavy 
and  the  thickening  is  starch  or  flour,  the  goods  are  usually  twice  dunged,  with  two  wash- 
ings between  the  two  dungs.  A  strong  acid  mordant  is  more  difficult  to  dung  and  to 
wash  than  a  neutral  mordant,  especially  when  it  is  to  receive  the  madder  dye.  Some- 
times a  little  chalk  is  added  to  the  bath,  when  the  goods  have  been  padded  in  an  acid 
mordant.  Too  much  dung  is  injurious  to  weak  mordants,  as  well  as  to  pinks.  It  has 
also  been  lemarked  that  a  mordant  when  neutralized  does  not  produce  as  brilliant  tints, 
especially  yellows.  The  latter  are  obtained  of  a  finer  shade  when,  instead  of  dunging, 
they  are  exposed  for  an  hour  in  a  stream  of  water,  provided  its  temperature  is  not  too 
low.  In  winter  they  are  passed  through  a  slightly  chalky  water,  then  washed  at  the 
wheel,  and  dyed  in  quercitron  or  weld. 

A  very  able  and  learned  memoir  upon  this  subject,  by  M.  Penot,  Professor  of  Chem- 
istry, appeared  in  the  Bulletin  of  the  Society  of  Mulhausen,  in  October,  1834,  with  an 
ingenious  commentary  upon  it,  under  the  title  of  a  Report  by  M.  Camille  Koechlin,  ia 
March,  1835. 

Experience  has  proved  that  dunging  is  one  of  the  most  important  steps  in  the  process 
of  calico  printing,  and  that  if  it  be  not  well  performed  the  dyeing  is  good  for  nothing. 
Before  we  can  assis?n  its  peculiar  function  to  the  dung  in  this  case,  we  must  know  its 
composition.  Fresh  cow's  dung  is  commonly  neutral  when  tested  by  litmus  paper;  but 
sometimes  it  is  slightly  alkaline,  owing,  probably,  to  some  peculiarity  in  the  food  of  the 
animal. 

The  total  constituents  of  100  parts  of  cow  duns:  are  as  follows :  Water,  69-58 ;  bitter 
matter,  0-74 ;  sweet  substance,  0-93 ;  chlorophylle,  0-28 ;  albumine,  0-63  ;  muriate  of 
soda,  0-08;  sulphate  of  potash,  0-05 ;  sulphate  of  lime,  0-25 ;  carbonate  of  lime,  0-24; 
phosphate  of  lime,  0-46;  carbonate  of  iron,  009;  woody  fibre,  26-39 ;  silica,  0-14; 
loss,  0-14. 

In  dunging  calicoes  the  excess  of  uncombined  mordant  is  in  part  attracted  by  the 
soluble  matters  of  the  cow's  dung,  and  forms  an  insoluble  precipitate,  which  has  no 
affinity  for  the  cloth,  especially  in  presence  of  the  insoluble  part  of  the  dung,  which 
strongly  attracts  alumina.  The  most  important  part  which  that  insoluble  matter  plays, 
is  to  seize  the  excess  of  the  mordants,  in  proportion  as  they  are  dissolved  by  the  water 
of  the  balh,  and  thus  to  render  their  reaction  upon  the  cloth  impossible.  It  is  only  ia 
the  deposite,  therefore,  that  the  matters  carried  off  from  the  cloth  by  the  dung  are  to 
be  found. 

M.  Camille  Koechlin  ascribes  the  action  of  cow  dung  chiefly  to  its  albuminous  con- 
stituent, combining  with  the  alumina  and  iron,  of  the  acetates  of  these  bases  dissolved 
by  the  hot  water  of  the  bath.  The  acids  consequently  set  free,  soon  become  evident  by 
the  test  of  litmus  paper,  after  a  few  pieces  are  passed  through,  and  require  to  be  got  rid 
of  either  by  a  fresh  bath  or  by  adding  chalk  to  the  old  one.  The  dun?  thus  serves  also 
to  fix  the  bases  on  the  cloth,  when  used  in  moderation.  It  exercises  likewise  a  disoxyda- 
ting  power  on  the  iron  mordant,  and  restores  it  to  a  state  more  fit  to  combine  with  color- 
ing  matter. 

DYEING,  (Teinturey  Fr. ;  Farherei,  Germ.)  is  the  art  of  impregnating  wool,  sUk, 
cotton,  linen,  hair,  and  skins,  with  colors  not  removable  by  washing,  or  the  ordinary 
usage  to  which  these  fibrous  bodies  are  exposed  when  worked  up  into  articles  of  furniture 
or  raiment.  I  shall  here  consider  the  general  principles  of  the  art,  referring  for  the 
particular  dyes,  and  peculiar  treatment  of  the  stuffs  to  be  dyed,  to  the  different  tinctorial 
substances  m  their  alphabetical  places ;  such  as  cochineal,  indigo,  madder,  &c. 

Dyeing  is  altogether  a  chemical  process,  and  requires  for  its  due  explanation  and 
practice  an  acquaintance  with  the  properties  of  the  elementary  bodies,  and  the  laws 
which  regulate  their  combinations.  It  is  true  that  many  operations  of  this,  as  of  other 
chemical  arts,  have  been  practised  from  the  most  ancient  times.  Ion?  before  any  jusi 
▼lews  were  entertained  of  the  nature  of  the  changes  that  took  place.  Mankind,  equally 
in  the  rudest  and  most  refined  state,  have  always  sought  to  gratify  the  love  of  distinctioa 


602 


DYEING. 


by  staining  their  dress,  sometimes  even  their  skin,  with  gaudy  colors.  Moses  speaks  of 
raiment  dyed  blue,  and  purple,  and  scarlet,  and  of  sheep  skins  dyed  red;  circumsiancet 
Which  indicate  no  small  degree  of  tinctorial  skill.  He  enjoins  purple  siufls  for  the  works 
of  the  tabernacle  and  the  vestments  of  the  high  priest. 

In  the  article  Calico  Printing,  I  have  shown  from  Pliny  that  the  ancient  Egyptians 
cultivated  that  art  with  some  degree  of  scientific  precision,  since  they  knew  the  use  of 
mordants,  or  those  substances  which,  though  they  may  impart  no  color  themselves,  yet 
enable  white  robes  (Candida  vela)  to  absorb  coloring  drugs  (colorem  sorbetidibus  medi- 
carmntis).  Tyre,  however,  was  the  nation  of  antiquity  which  made  dying  its  chief 
occupation  and  the  staple  of  its  commerce.  There  is  little  doubt  that  purple,  the  sacred 
symbol  of  royal  and  sacerdotal  dignity,  was  a  color  discovered  in  that  city,  and  that  it 
contributed  to  its  opulence  and  grandeur.  Homer  marks  no  less  the  va'lue  than  the 
antiquity  of  this  dye,  by  describing  his  heroes  as  arrayed  in  purple  robes.  Purple  habits 
are  mentioned  among  the  presents  made  to  Gideon  by  the  Israelites  from  the  spoils  of  the 
kings  of  Midian. 

The  juice  employed  for  communicating  this  dye  was  obtained   from  two  diiferent 
kinds  of  shell-fish,  described  by  Pliny  under  the  names  of  pwrpttra  and  buccinum;  and 
was  extracted  from  a  small  vessel,  or  sac,  in  their  throats,  to  the  amount  of  only  one 
drop  from  each  animal,    A  darker  and  inferior  color  was  also  procured  by  crushing  the 
whole  substance  of  the  buccinnm.     A  certain  quantity  of  the  juice  collected  from  a  vast 
number  of  shells  being  treated  with  sea-salt  was  allowed  to  ripen  for  three  days ;  after 
which  it  was  diluted  with  five  times  its  bulk  of  water,  kept  at  a  moderate  heat  for  six 
days  more,  occasionally  skimmed  to  separate  the  animal  membranes,  and  when   thus 
clarified  was  applied  directly  as  a  dye  to  white  wool,  previously  prepared  for  this  purpose 
by  the  action  of  lime-water,  or  of  a  species  of  lichen  called  fucus.    Two  operations  were 
requisite  to  communicate  the  finest  Tyrian  purple ;  the  first  consisted  in  plunging  the 
wool  into  the  juice  of  the  purpura  :  the  second,  into  that  of  the  buccinum.    Fifty  drachms 
of  wool  required  one  hundred  of  the  former  liquor,  and  two  hundred  of  the  latter.     Some- 
times a  preliminary    tint  was  given  with  coccus,  the  kermes  of  the  present  day,  at 
cloth  received  merely  a  finish  from  the  precious  animal  juice.    The  colors,  though 
'  not  nearly  so  brilliant  as  those  producible  by  our  cochineal,  seem  to  have  beei 
ible,  for  Plutarch  says,  in  his  Life  of  Mexander,  (chap.  36,)  that  the  Greeks 
he  treasury  of  the  King  of  Persia  a  large  quantity  of  purple  cloth,  which  v 
itiful  as  at  first,  though  it  was  190  years  old.* 

he  difficulty  of  collecting  the  purple  juice,  and  the  tedious  complication  of  the 
ess,  made  the  purple  wool  of  Tyre  so  expensive  at  Rome,  that  in  the  time  of  i 
a  pound  of  it  cost  nearly  30/.  of  our  money.f      Notwithstanding  this  enormous 
such  was  the  wealth  accumulated  in  that  capital,  that  many  of  the  leading  citizens  deco- 
rated themselves  in  purple  attire,  till  the  emperors  arrogated  to  themselves  the  privilege 
of  wearing  purple,  and  prohibited  its  use  to  every  other  person.     This  prohibition  opera- 
ted so  much  to  discourage  this  curious  art  as  eventually  to  occasion  its  extinction,  first  in 
the  western  and  then  in  the  eastern  empire,  where,  however,  it  existed  in  certain  imperial 
manufacturies  till  the  eleventh  century. 

Dyeing  was  little  cultivated  in  ancient  Greece;  the  people  of  Athens  wore  generally 
woolJendresses  of  the  natural  color.  But  the  Romans  must  have  bestowed  some  pains 
upon  this  an.  In  the  games  of  the  circus  parties  were  distinguished  by  colors.  Four  of 
these  are  described  by  Pliny,  the  green,  the  orange,  the  gray,  and  the  white.  The  follow- 
ing ingredients  were  used  by  their  dyers.  A  crude  native  alum  mixed  with  copperas, 
copperas  itself,  blue  vitriol,  alkanet,  lichen  rocellus,  or  archil,  broom,  madder,  woad,  nut- 
galls,  the  seed  of  pomegranate,  and  of  an  Egyptian  acacia. 

Gage,  Cole,  Plumier,  Reaumur,  and  Duhamel  have  severally  made  researches  concern- 
ing the  colormg  juices  of  shell-fish  caught  on  various  shores  of  the  ocean,  and  have  suc- 
ceeded m  formmg  a  purple  dye,  but  they  found  it  much  inferior  to  that  furnished  by  other 
means.  The  juice  of  the  buccinum  is  at  first  white ;  it  becomes  by  exposure  to  air  of  a 
yellowish  green  bordering  on  blue;  it  afterwards  reddens,  and  finally  changes  to  a  deep 
purple  of  considerable  vivacity.  These  circumstances  coincide  with  the  minute  descrip- 
tion of  the  manner  of  catching  the  purple-dye  shell-fish  which  we  possess  in  the  work  of 
an  eye-witness,  Eudocia  Macrembolitissa,  daughter  of  the  Emperor  Constaniine  VIII., 
who  lived  in  the  eleventh  century. 

The  moderns  have  obtained  from  the  New  World  several  dye-drugs  unknown  to  the 
•ncients ;  such  as  cochineal,  quercitron,  BrazU  wood,  logwood,  annalto ;  and  they  have 

iw  "^"°n|  ot^"  things,  there  was  purple  of  Hermione  (T)  to  the  amount  of  five  thou.and  talenH." 
(Flutareh  8  Lives,  translated  by  Langhorne,  Wrangham's  edition,  vol.  v.  p.  240.)  Horace  celebrates  th« 
Laconian  dye  m  the  following  hnes :—  *~         /  «• 

Nen  Lanonicas  mihi 

Trahant  honests  purpuras  cliente. 

AW  .1-  .  J    <■  1^     .     . .     ..       .  _»  (Carm.  lib.  ii.,  Ode  18.) 

f  niiy  saya  that  a  pound  of  the  doible-dipped  Tyrian  purple  was  sold  in  Rome  for  a  hundred  crowniL 


DYEING. 


603 


discovered  the  art  of  using  indigo  as  a  dye,  which  the  Romans  knew  only  as  a  pigment. 
Bat  the  vast  superiority  of  our  dyes  over  those  of  former  times  must  be  ascribed  princi- 
pally to  the  employment  of  pure  alum  and  solution  of  tin  as  mordants,  either  alone  or 
mixed  with  other  bases;  substances  which  give  to  our  common  dye-stutts  remarkable 
depth,  durability,  and  lustre.  Another  improvement  in  dyeing  of  more  recent  date  is  the 
application  to  textile  substances  of  metallic  compounds,  such  as  Prussian  blue,  chrome 

yellow,  manganese  brown,  &c.  ..../•«•    i  ..i»~*o 

Indiijo,  the  innoxious  and  beautiful  product  of  an  interesting  tribe  of  tropical  plants, 
which  is  adapted  to  form  the  most  useful  and  substantial  of  all  dyes,  was  actually  denoun- 
ced as  a  dangerous  drug,  and  forbidden  to  be  used,  by  our  parliament  in  the  reign  of 
Queen  Elizabeth.  An  act  was  passed  authorizing  searchers  to  burn  both  it  and  logwood 
in  every  dye-house  where  they  could  be  found.  This  act  remained  m  full  force  till  the 
time  of  Charles  II. ;  that  is,  for  a  great  part  of  a  century.  A  foreigner  l  ight  have  sup- 
posed that  the  legislators  of  England  entertained  such  an  affection  for  their  native  woad, 
with  which  their  naked  sires  used  to  dye  their  skins  in  the  old  times,  that  they  would 
allow  no  outlandish  drug  to  come  in  competition  with  it.  A  most  instructive  book  might 
be  written  illustrative  of  the  evils  inflicted  upon  arts,  manufactures,  and  commerce,  in 
consequence  of  the  ignorance  of  the  legislature.* 

Colors  are  not,  properly  speaking,  material ;  they  are  impressions  which  we  receive 
from  the  rays  of  light  reflected,  in  a  decomposed  state,  by  the  surfaces  of  bodies.  It  is 
well  known  that  a  white  sunbeam  consists  of  an  indeterminate  number  Oi'  -'ifferently  col- 
ored rays  which  being  separated  by  the  refractive  force  of  a  glass  prism,  .brm  the  solar 
spectrum  'an  image  distinguishable  into  seven  sorts  of  rays ;  the  red,  orange,  yellow, 
green,  blue,  indigo,  and  violet.  Hence,  when  an  opaque  body  appears  colored,  for  ex- 
ample, red,  we  say  that  it  reflects  the  red  rays  only,  or  in  greatest  abundance,  mixed  with 
more  or  less  of  the  white  beam,  which  has  escaped  decomposition.  According  to  this 
manner  of  viewing  the  coloring  principle,  the  art  of  dyein?  consists  in  fixing  upon  stuffs, 
by  means  of  corpuscular  attraction,  substances  which  act  upon  light  in  a  different  manner 
from  the  surfaces  of  the  stuffs  themselves.  The  dyer  ought,  therefore,  to  be  familiar  with 
two  principles  of  optics ;  the  first  relative  to  the  mixture  of  colors,  and  the  second  to  their 

simultaneous  contrast. 

Whenever  the  different  colored  rays,  which  have  been  separated  by  the  p--i5m,  are 
totally  reunited,  they  reproduce  white  light.  It  is  evident,  that  in  this  composition 
of  lit'ht,  if  some  rays  were  left  out,  or  if  the  colored  rays  be  not  in  a  certain  proportion, 
we  should  not  have  white  light,  but  light  of  a  certain  color.  For  example;  if  we 
separate  the  red  rays  from  the  light  decomposed  by  a  prism,  the  remaining  colored 
rays  will  form  by  their  combination  a  peculiar  bluish  green.  If  we  separate  in  like 
manner  the  orange  rays,  the  remaining  colored  rays  will  form  by  their  combination 
a  blue  color.  If  we  separate  from  the  decomposed  prismatic  light  the  rays  of  greenish 
yellow  the  remaining  colored  rays  will  form  a  violet.  And  if  we  separate  the  rays  of 
yellow'bordering  on  orange,  the  remaining  colored  rays  will  form  by  their  union  an  indigo 

Thus  we  see  that  every  colored  light  has  such  a  relation  with  another  colored  light 
that,  by  uniting  the  first  with  the  second,  we  reproduce  white  light ;  a  relation  which  we 
express  by  saying  that  the  one  is  the  complement  of  the  other.  In  this  sense,  red  is  the 
complementary  color  of  bluish  green;  orange,  of  blue;  greenish  yellow,  of  violet;  and 
orange  yellow,  of  indigo.  If  we  mix  the  yellow  ray  with  the  red,  we  produce  orange; 
the  bine  rar  with  the  yellow,  we  produce  green ;  and  the  blue  with  the  red,  we  produce 
violet  or  indigo,  according  as  there  is  more  or  less  red  relatively  to  the  blue.  But  these 
tints  are  distinguishable  from  the  orange,  green,  indigo,  and  violet  of  the  solar  spectrum, 
because  when  viewed  through  the  prism  they  are  reduced  to  their  elementary  compound 

If  the  dyer  tries  to  realize  the  preceding  results  by  the  mixture  of  dyes,  he  will  succeed 
only  with  a  certain  number  of  them.  Thus,  with  red  and  yellow  he  can  make  orange ; 
with  blue  and  yellow,  green ;  with  blue  and  red,  indigo  or  violet.  These  facts>  the 
results  of  practice,  have  led  him  to  conclude  that  there  are  only  three  primitive  colors ; 
the  red,  yellow,  and  blue.  If  he  attempts  to  make  a  white,  by  applying  red,  yellow, 
and  blue  dyes  in  certain  quantities  to  a  white  stuff,  in  imitation  of  the  philosopher's  ex- 
periment on  the  synthesis  of  the  sunbeam,  far  from  succeeding,  he  wUl  deviate  still  further 
from  his  purpose,  since  the  stuff  will  by  these  dyes  become  so  dark  colored  as  to  appear 

black 

The  fact  must  not,  however,  lead  us  to  suppose  that  in  every  case  where  red,  yellow, 
and  blue  are  applied  to  white  cloth,  black  is  produced.  In  reality,  when  a  little  ultra- 
marine cobalt  blue,  Prussian  blue,  or  indigo,  is  applied  to  goods  with  the  vrow  of  giving 
them  the  best  possible  white,  if  only  a  certain  proportion  be  used,  the  goods  wiU  appear 
whiter  after  this  addition  than  before  it.     What  happens  in  this  case  ?     The  violet  blue 

*  Author,  in  Penny  Cyclopedia. 


7   1 


604 


DYEING. 


DYEING. 


605 


i 


fomw,  with  the  brown  yellow  of  the  goods,  a  mixture  tending  to  white  or  less  colnr«i 
than  the  yellow  of  the  goods  and  the  blue  together  were.     For  thrsameTeaco^  Tm^ 

!h!  M^Tlf^  ''l*"'',?"  r-^'"'^"*^^  *°  *  P"'«  *>^"«'  ''«'  «"  examining  closely  the  co  of  i 
the  s.lk  to  be  neutralized  It  was  found  by  the  relations  of  the  complementary  colo^,  thM 
the  violet  was  more  suitable  than  the  indigo  blue  formerly  used.  The  dyer  shouOnow 
that  when  he  applies  several  different  coloring  matters  to  stuffs,  as  yeUow  and  blue  foi 
example  If  they  appear  green,  it  is  because  the  eye  cannot  distinguish  the  t^nts  wh  ch 
reflect  the  yellow  from  those  which  reflect  the  blue;  and  that,  consequentHt  17^ 

TxWn  '  ^f  .^"^^^^'^  ^«  r'  P^'^'^^"'  '^^'  ^  "^'^'"••^  «^  combination  appears  ^Whe„wJ 
examine  certam  gray  substances,  such  as  hairs,  feathers,  &c.,  with  the  microscone  w« 
see  that  the  gray  color  results  from  black  points  disseminated  over  a  coLTiror  suthly 
:Slltret;!ke  dy"e "'"'""  to  compound  colors,  this  instrument  might  be^u^s^^wlJj 

colI^L^  '^Wh'''''?i'*  ^  acquainted  also  with  the  law  of  the  simultaneous  contrast  of 
colors.  When  the  eye  views  two  colors  close  alongside  of  each  other,  it  sees  them 
differing  mos   m  their  optical  composition,  and  in  the  height  of  their  Tne' when  the  iw^ 

^iSonThln'r''  "'  'r"-'"''''-    r  \^''  ^PP^"  '"^^^  ^^^'^'^^  ^^  toTheir  optVal^^^^  • 
ThuTnJ.V.      '^^^P'^^^"^.?  °f/he  one  of  them  is  added  to  the  color  of  the  other.- 

green  ben^fdZ  f^ .t  *'^°^'*^^  ^^.^  r"^« -<>"«;  the  red  color  complementary  of 
green,  being  added  to  the  orange,  wiU  make  it  appear  redder;  and   in  like  manner  the 

tensely  blue.  In  order  to  appreciate  these  differences,  let  us  take  two  green  strides  and 
two  orange  stnpes,  placing  one  of  the  green  stripes  near  one  of  the  oran 'e  Len  nla^ 
^e  two  others  so  that  the  green  stripe  may  be  at  a  distance  from  the  o^ her  i^reen  strio? 
^^side  ''"''  "'^"'  *"^  '**'  "'*"""  ^'  ^  '^^^^""^^  ^^^"^  '^^  other  on;nge,'aL  on  uS 
to^^  Nn^?  TnTf}''  t"^  ^'T^J  ""^  ?^'^"^'  ^^  ""^y  ^^''^r  ourselves  by  taking  the 
oy  placing  iVo  2  and  No.  15  close  alongside,  putting  No.  1  at  a  distance  from  No   2 

Zar  l^rjtl'  '"'  ^°-  'Y\  ""  '''1'''''  ^'-^"^  ^'-  ''  «"  ^he  same  i^e'we  sM 
see  (If  the  pallet  is  sufficiently  lowered  in  tone)  No.  2  equal  to  No.   1   and  No    IS 

equal  to^o.  16;  whence  it  follows  that  No.  2,  by  the  vicinity  of  No   15  wUl  an^elx 
to  have  lost  some  of  its  color;  while  No.  15  will  appear  to  havj acquired  coW       Wto 
black  or  gray  figures  are  printed  upon  colored  grounds,  these  figures  are  of  the  color 
crotTa.'?  "'  ^''-^"""r'-      ^«-^''-»^^y»  -  «^der  to  judge  of  thdr    dor,  we  mis 
bn      tT  *  r-r^  ^^  ^.'l^  ^'  ^^'^^  P^P^""'  ^«  *«  ^«  ^"«^  the  eye  to  see  nothing 

Irl    5      r^'V'  ^""^  f  ^^  "^''^  '«  ^^^"^P*''^  fi?"'^^  «^  the  same  color,  applied  uiSn 

The  relations  of  dyeing  with  the  principles  of  chemistry,  constitute  the  theory  of  the 
art,  properly  speaking;  this  theory  has  for  its  basis,  the  knowledge-1.  of  the  species  of 

^L7ac"   s'^f^fh'T'"'  '"""i"^?  '^"^^^^i  '•.  '^  ^^«  circumstances  in  ;hfchSese 
pkI^  «r  ,k'      ,    i,  *"  Phf."^'".^'^^  ^i^ich  appear  during  their  action;  and  4.  of  the  prop. 

iT.nVi:tztiZ^T^s:^'" ^"  ^^^"^- '''''' '-''''''''''  "-^  '^  '^^- 

thi*hTi!f  P^^r'*^'''"  ""^  ^^^  '^"^'  *°  ^  '^y^'^'  ^^e^he*-  fi^'-es,  yarn,  or  cloth ;  under 
^e^ heads  of  ligneous  matter,  cotton,  hemp,  flax;  and  of  the  animal  matters,  silk  ami 

2.  The  mutual  action  of  these  stuffs,  and  simple  bodies. 
d,  Ihe  mutual  action  of  these  stuffs,  and  acids. 

4.  The  mutual  action  of  these  stuffs,  and  salifiable  bases,  as  alumina,  &c. 

5.  J  he  mutual  action  of  these  stuffs,  and  salts. 

6.  The  mutual  action  of  these  stuffs,  and  neutral  compounds  not  saline. 

ft    nPA?'\}  T'''''  °^.'^^'^  ^^"^''  *"^  °^  °^«  o'-  "ore  definite  compounds. 

«.  Ut  dyed  stufls  considered  in  reference  to  the  fastness  of  their  color,  under  the  in. 
fluence  of  heat,  light,  water,  oxygen,  air,  boilings  with  soap,  and  reagenU. 

?A    /^r  ?,^'"-'  considered  in  its  connexions  with  chemistry, 
opt^w.         ^^'"^'  considered  in  its  relations  with  caloric,  mechanics,  hydrauUcs,  and 

1.  The  preparation  of  stuffs. 

The  operations  to  which  stuffs  are  subjected  before  dyeing,  are  intended-1.  to  sepa. 
rae  from  them  any  foreign  matters;  2.  to  render  them  mire  apt  to  unite  withX 

S^rr^fJ^K  ""'  "^^"^  K^n'^^r  P''^P°^"^  '°  «^  "P«»  »»»«">  i»  o^der  to  give  them  • 
Tni-rf  K  '  ""^  °»ore  brilliant  aspect,  or  to  lessen  their  tendency  to  assume  a  soiled 
appearance  by  use,  which  while  surfaces  so  readily  do.  The  foreign  matters  are  eithS 
naturally  mlierent  m  the  stufls,  or  added  to  them  ia  the  spinning,  weaving,  or  oth« 


™.inipulation  of  manufacture.  The  ligneous  fibres  must  be  freed  from  the  colored  azo- 
l^xed  varnish  on  their  surface,  from  a  yellow  coloring  matter  in  their  substance,  from 
some  lime  and  iron,  from  chlorophylle  or  leaf-green,  and  from  pectic  acid ;  all  natural 
combinations.  Some  of  these  principles  require  to  be  oxygenized  before  alkaline  leys 
can  cleanse  them,  as  I  have  stated  in  the  article  Bleaching,  which  may  be  consulted  in 
reference  to  this  subject.  See  also  Silk  and  Wool.  A  weak  bath  of  soda  has  the  prop- 
erty of  preparing  wool  for  taking  on  a  uniform  dye,  but  it  must  be  well  rmsed  and  aired 
before  bein?  put  into  the  dye-vat. 

2.  Mutual  action  of  stuffs  and  simple  bodies.  . 
Stuffs  chemically  considered  being  composed  of  three  or  four  elements,  already  m  a 

state  of  reciprocal  saturation,  have  but  a  feeble  attraction  for  simple  substances.  We 
know  in  fact,  that  the  latter  combine  only  with  each  other,  or  with  binary  compounds, 
and  that  in  the  greater  number  of  cases  where  they  exert  an  action  upon  more  complete 
compounds,  it  is  by  disturbing  the  arrangement  of  their  elements,  and  not  by  a  resulting 
affinity  with  the  whole  together. 

3,  4.  Although  stuffs  may  in  a  general  point  of  view  be  considered  as  neutral  in 
relation  to  coloring  reagents,  yet  experience  shows  that  they  are  more  disposed  to  com- 
bine with  acid  than  with  alkaline  compounds ;  and  that  consequently  their  nature  seems 
to  be  more  alkaline  than  acid.  By  steeping  dry  wool  or  other  stuff  in  a  clean  state  in 
an  alkaline  or  acid  solution  of  known  strength,  and  by  testing  the  liquor  after  the  stuff 
is  taken  out,  we  shall  ascertain  whether  there  be  any  real  affinity  between  them,  by  the 
solution  being  rendered  more  dilute  in  consequence  of  the  abstraction  of  alkaline  or  acid 
particles  from  it.  Wool  and  silk  thus  immersed,  abstract  a  portion  of  both  sulphuric  and 
teuriatic  acids;  but  cotton  and  flax  imbibe  the  water,  with  the  rejection  of  a  portion  of 
the  acid.  The  acid  may  be  again  taken  from  the  stuffs  by  washing  them  with  a  sufficient 
quantity  of  water.  ... 

6.  The  affinity  between  saline  bodies  and  stuffs  may  be  ascertained  in  the  same  way 
as  that  of  acids,  by  plunging  the  dry  stuffs  into  solutions  of  the  salts,  and  determining 
the  density  of  the  solution  before  the  immersion,  and  after  withdrawing  the  stuffs. 
Wool  abstracts  alum  from  its  solution,  but  it  gives  it  all  out  again  to  boiling  water. 
The  sulphates  of  protoxyde  of  iron,  of  copper,  and  zinc,  resemble  alum  in  this  respect. 
When  silk  is  steeped  for  some  time  in  solution  of  protosulphate  of  iron,  it  abstracts  the 
oxyde,  gets  thereby  dyed,  and  leaves  the  solution  acidulous.  Wool  put  in  contact  with 
cream  of  tartar  decomposes  a  portion  of  it;  it  absorbs  the  acid  into  its  pores,  and  leaves 
a  neutral  salt  in  the  liquor.  The  study  of  the  action  of  salts  upon  stuffs  is  at  the  pres- 
ent day  the  foundation  of  the  theory  of  dyeing ;  and  some  of  them  are  employed  imme- 
diately as  dye-drugs. 

6.  Mutual  action  of  stuffs,  and  neutral  compounds  not  saline. 

Several  sulphurets,  such  as  those  of  arsenic,  lead,  copper,  antimony,  tin,  are  suscepti- 
ble of  being  applied  to  stuffs,  and  of  dyeing  them  in  a  more  or  less  fast  manner.  Indigo, 
hematine,  breziline,  carmine,  and  the  peculiar  coloring  principles  of  many  dyes  belong 

to  this  division. 

7.  Mutual  action  of  goods  with  one  or  more  definite  compounds,  and  dye  stuffs. 

I  shall  consider  here  in  a  theoretical  point  of  view,  the  most  general  results  which 
a  certain  number  of  organic  coloring  matters  present,  when  applied  upon  stuffs  by  the 

dyer. 

Indigo.  This  dye-drug,  when  tolerably  good,  contains  half  its  weight  of  indigotine. 
The  cold  vat  is  prepared  commonly  with  water,  copperas,  indigo,  lime,  or  sometimes  car- 
bonate of  soda,  and  is  used  almost  exclusively  for  cotton  and  linen ;  immersion  in  acidu- 
lated watei  Is  occasionally  had  recourse  to  for  removing  a  little  oxyde  of  iron  which 
attaches  itself  to  the  cloth  dyed  in  this  vat. 

The  indigo  vat  for  wool  and  silk  is  mounted  exclusively  with  indigo,  good  potashes  of 
commerce,  madder,  and  bran.  In  this  vat,  the  immediate  principles  with  base  of  carbon 
and  hydrogen,  such  as  the  extracts  of  madder  and  bran,  perform  the  disoxydizing  func- 
tion of  the'^copperas  in  the  cold  vat.  The  pastel  vats  require  most  skill  and  experience, 
in  consequence  of  their  complexity.  The  greatest  difficulty  occurs  in  keeping  them  in  a 
good  condition,  because  they  vary  progressively  as  the  dyeing  goes  on,  by  the  abstraction 
sf  the  indigotine,  and  the  modification  of  the  fermentable  matter  employed  to  disoxyge- 
nate  the  indigo.  The  alkaline  matter  also  changes  by  the  action  of  the  air.  By  the  suc- 
cessive additions  of  indigo,  alkali,  &c.,  this  vat  becomes  very  difficult  to  manage  with 
profit  and  success.  The  great  affair  of  the  dye  •  's  the  proper  addition  of  lime ;  too  much 
or  too  little  being  equally  injurious.  ,      r/.  .u  i    w« 

Sulphate  of  indigo  or  Saxon  blue  is  usea  also  to  dye  silk  and  wool.  If  the  wools  t>e 
ill  sorted  it  will  show  their  differences  by  the  inequalities  of  the  dye.  Wool  dyed  m  this 
bath  put  'into  water  saturated  with  sulphureied  hydrogen,  becomes  soon  colorless,  owing 
to  the  disoxygenation  of  the  indigo.  The  woollen  cloth,  when  exposed  to  the  air  for  some 
time  resumes  its  blue  color,  but  not  so  intensely  as  before. 


606 


DYEING. 


DYEING. 


607 


The  properties  of  hematine  explain  the  mode  of  using  logwood.  When  stuffs  are 
dyed  in  the  infusion  or  decoction  of  this  wood,  under  the  influence  of  a  base  which  acts 
upon  the  hematine  in  the  manner  of  an  alkali,  a  blue  dye,  bordering  upon  violet  is 
obtained.  Such  is  the  process  for  dyeing  cotton  and  wool  a  logwood  blue  by  means  of 
verdigris,  crystallized  acetate  of  copper,  and  acetate  of  alumina. 

When  we  dye  a  stuff  yellow,  red,  or  orange,  we  have  always  bright  tints;  with  blue, 
we  may  have  a  very  dark  shade,  but  somewhat  violet ;  the  proper  black  can  be  obtained 
only  by  using  the  three  colors,  blue,  red,  and  yellow,  in  proper  proportions.  Hence  we 
can  explain  how  the  tints  of  yellow,  red,  orange,  blue,  green,  and  violet,  may  be  browned, 
by  applying  to  them  one  or  two  colors  which  along  with  themselves  would  produce 
black ;  and  also  we  may  explain  the  nature  of  that  variety  of  blacks  and  grays  which 
seems  to  be  indefinite.  Nutgalls  and  sulphate  of  iron,  so  frequently  employed  for  the 
black  dye,  give  only  a  violet  or  bluish  gray.  The  pyrolignite  of  iron,  which  contains 
a  brown  empyreumatic  matter,  gives  to  stuffs  a  brown  tint,  bordering  upon  greenish 
yellow  in  the  pale  hues,  and  to  chestnut  brown  in  the  dark  ones.  By  galling  cotton 
and  silk,  and  giving  them  a  bath  of  pyrolignite  of  iron,  we  may,  after  some  alterna- 
tions, dye  them  black.  Galls,  logwood,  and  a  salt  of  iron,  produce  merely  a  very  deep 
violet  blue;  but  by  boiling  and  exposure  to  air,  the  hematate  of  iron  is  changed,  becom- 
ing red-brown,  and  favors  the  production  of  black.  Galls  and  salts  of  copper  dye  stuflt 
an  olive  drab,  logwood  and  salts  of  copper,  a  violet  blue;  hence  their  combination  should 
produce  a  black.  In  using  sumach  as  a  substitute  for  galls,  we  should  take  into  account 
the  proportion  of  yellow  matter  it  contains.  When  the  best  possible  black  is  wanted 
upon  wool,  we  must  give  the  stuff  a  foundation  of  indigo,  then  pass  it  into  a  bath  of  log- 
wood, sumach,  and  proto-sulphate  of  iron.  The  sumach  may  be  replaced  by  one  third  of 
its  weight  of  nutgalls. 

8.  Of  dyed  stuffs  considered  in  reference  to  the  fastness  of  their  colors,  when  exposed 
to  water,  light,  heat,  air,  oxygen,  boiling,  and  reagents. 

Pure  water  without  air  has  no  action  upon  any  properly  dyed  stuff. 

Heat  favors  the  action  of  certain  oxygenized  bodies  upon  the  carbonaceous  and  hydro- 
genous constituents  of  the  stuff;  as  is  seen  with  regard  to  chromic  acid,  and  peroxyde  of 
manganese  upon  cotton  goods.  It  promotes  the  solvent  action  of  water,  and  it  even  affects 
some  colors.  Thus  Prussian  blue  applied  to  silk,  is  reduced  to  peroxyde  of  iron  by  long 
boiling. 

Light  without  contact  of  air  affects  very  few  dyes. 

Oxygen,  especially  in  the  nascent  state,  is  very  powerful  upon  dyes.     See  Bleaching, 

The  atmosphere  in  a  somewhat  moist  state  affects  many  dyes,  at  an  elevated  tcm 
perature.  Silk  dyed  pink,  with  safflower,  when  heated  to  400*  F.,  becomes  of  a  dirty 
white  hue  in  the  course  of  an  hour.  The  violet  of  logwood  upon  alumed  wool  becomes 
of  a  dull  brown  at  the  same  temperature  in  the  same  time.  But  both  stand  a  heat  of 
300*  F.  Brazil  red  dye,  turmeric,  and  weld  yellow  dyes,  display  the  same  phenomena. 
These  facts  show  the  great  fixity  of  colors  commonly  deemed  lender.  The  stuffs 
become  affected  to  a  certain  degree,  under  the  same  circumstances  as  the  dyes.  The 
alterabiliiy  even  of  indigo  in  the  air  is  shown  in  the  wearing  of  pale  blue  clothes ;  in 
the  dark  blue  cloth  there  is  such  a  body  of  color,  that  it  resists  proportionally  longer ; 
but  the  seams  of  coats  exhibit  the  effect  very  distinctly.  In  silk  window  curtains,  which 
have  been  long  exposed  to  the  air  and  light,  the  stuff  is  found  to  be  decomposed,  as  well 
as  the  color. 

Boiling  was  formerly  prescribed  in  France  as  a  test  of  fast  dyes.  It  consisted  in 
putting  a  sample  of  the  dyed  goods  in  boiling  water,  holding  in  solution  a  determinate 
quantity  of  alum,  tartar,  soap,  and  vinegar,  &c.  Dufay  improved  that  barbarous  lest. 
He  considered  that  fast-dyed  cloth  could  be  recognised  by  resisting  an  exposure  of  twelve 
hours  to  the  sunshine  of  summer,  and  to  the  midnight  dews;  or  of  sixteen  days  in 
winter. 

In  trying  the  stability  of  dyes,  we  may  offer  the  following  rules : — 

That  every  stuff  should  be  exposed  to  the  light  and  air ;  if  it  be  intended  to  be  worn 
abroad,  it  should  be  exposed  also  to  the  wind  and  rain ;  that  carpets,  moreover,  should  be 
subjected  to  friction  and  pulling,  to  prove  their  tenacity;  and  that  cloths  to  be  washed 
should  be  exposed  to  the  action  of  hot  water  and  soap. 

In  examining  a  piece  of  dyed  cotton  goods,  we  may  proceed  as  follows: — 

Suppose  its  color  to  be  orange-brown.  We  find  first  that  it  imparls  no  color  to  boil- 
ing water;  that  protochloride  of  tin  takes  out  its  color;  that  plunged  into  a  solution 
of  ferroprussiate  of  potash  it  becomes  blue ;  and  that  a  piece  of  it  being  burned,  leaves 
a  residuum  of  peroxyde  of  iron ;  we  may  thence  conclude  that  the  dyeing  matter  is 
peroxyde  of  iron. 

Suppose  we  have  a  blue  stuff  which  may  have  been  dyed  either  with  indigo  or  with 
Prussian  blue,  and  we  wish  to  know  what  it  will  become  in  use.  We  inquire  first  into 
the  nature  of  the  blue.    Hot  water  slightly  alkaline  will  be  colored  blue  by  it,  if 


it  has  been  dyed  with  sulphate  of  indigo ;  it  will  not  be  colored  if  it  was  dyed  in  the  indigo 
vat,  but  it  will  become  yellow  by  nitric  acid.  Boiling  water,  without  becoming  colored 
itself,  will  destroy  the  Prussian  blue  dye ;  an  alkaline  water  will  convert  its  color  into  an 
iron  rust  tint;  nitric  acid,  which  makes  the  indigo  dye  yellow,  makes  that  of  Prussian 
blue  green.  The  liquor  resulting  from  boiling  alkaline  water  on  the  Prussian  blue  cloth, 
will  convert  sulphate  of  iron  into  Prussian  blue. 

9.  Division.     Of  dyeing  viewed  in  its  relation  to  chemistry. 

The  phenomena  of  dyeing  have  been  ascribed  to  very  different  causes  ;  by  some  they 
were  supposed  to  depend  upon  mechanical  causes,  and  by  others  upon  the  forces  from 
which  chemical  effects  flow.  Hellot,  in  conformity  with  the  first  mode  of  explanation, 
thought  that  the  art  of  dyeing  consisted  essentially  in  opening  the  pores  in  order  to  admit 
coloring  matters  into  them,  and  to  fix  them  there  by  cooling,  or  by  means  of  a  mordant 
imagined  to  act  like  a  cement. 

Dufay  in  1737,  Bergmann  in  1776,  Macquer  in  1778,  and  Berthollet  in  1790,  had  re- 
course to  chemical  affinities,  to  explain  the  fixation  of  the  coloring  principles  upon  stuffs, 
either  without  an  intermedium,  like  indigc^  walnut  peels,  annotto;  or  by  the  interven- 
tion of  an  acid,  a  salifiable  base,  or  a  salt,  which  were  called  mordants.  W^hen  bodies 
present  phenomena  which  we  refer  to  an  attraction  uniting  particles  of  the  same 
nature,  whether  simple  or  compound,  to  form  an  aggregate,  or  to  an  aflinity  which 
unites  the  particles  of  different  natures  to  form  them  into  a  chemical  compound,  these 
bodies  are  in  apparent  contact.  This  happens  precisely  in  all  the  cases  of  the  mutual 
action  of  bodies  in  an  operation  of  dyeing ;  if  their  particles  were  not  in  apparent  con- 
tact, there  would  be  absolutely  no  change  in  their  respective  condition.  When  we  see 
stuffs  and  metallic  oxydes  in  apparent  contact,  form  a  mutual  union  of  greater  or  less 
force,  we  cannot  therefore  help  referring  it  to  aflinity.  We  do  not  know  how  many 
dyes  may  be  fixed  upon  the  same  piece  of  cloth ;  but  in  the  operations  of  the  dye-house 
sufl5ciently  complex  compounds  are  formed,  since  they  are  always  stuffs,  composed  of 
three  or  four  elements,  which  are  combined  with  at  least  binary  acid  or  basic  com- 
pounds; with  simple  salts  compounded  themselves  of  two  immediate  principles  at  least 
binary ;  with  double  salts  composed  of  two  simple  salts ;  and  finally  with  organic  dye- 
stuffs  containing  three  or  four  elements.  We  may  add  that  different  species  belonging 
to  one  of  these  classes,  and  different  species  belonging  to  different  classes,  may  nniie 
simultaneously  with  one  stuff.  The  union  of  stuffs  with  coloring  matters  appears,  in 
general,  not  to  lake  place  in  definite  proportions;  thouzh  there  are  probably  some 
exceptions. 

We  may  conclude  this  head  by  remarking,  that,  besides  the  stuff  anl  the  coloring 
matter,  it  is  not  necessary,  in  dyeing,  to  distinguish  a  third  body,  under  the  name  of  mor' 
dant ;  for  the  idea  of  mordant  does  not  rest  upon  any  definite  fact;  the  body  to  which 
this  name  has  been  given  being  essentially  only  one  of  the  immediate  principles  of  the 
colored  combination  which  we  wish  to  fix  upon  the  stuff. 

10.  Division.  Of  dyeing  in  its  relation  with  caloric,  mechanics,  hydraulics,  pneumatics, 
and  optics. 

Dyeing  baths,  or  coppers,  are  heated  directlyby  a  furnace,  or  by  means  of  steam  con- 
ducted in  a  pipe  from  a  boiler  at  a  certain  distance  from  the  bath.  In  the  first  case,  the 
vessels  are  almost  always  made  of  copper ;  only,  in  special  cases,  for  the  scarlet  and  some 
delicate  silk  dyes,  of  lin ;  in  the  second  case,  they  are  of  copper,  iron,  or  wood.  A  direct 
fire  is  more  economical  than  heating  steam  pipes,  where  there  is  only  one  or  two  baths  to 
heat,  or  where  the  labors  are  often  suspended.  Madder  and  indigo  vats,  when  heated  by 
steam,  have  it  either  admitted  directly  into  the  liquor,  or  made  to  circulate  through  pipes 
plunged  into  it,  or  between  the  copper  and  an  exterior  iron  or  wood  case.  See  the  end 
of  this  article. 

Everything  else  being  equal,  dyeing  with  heat  presents  fewer  difliculties  towards  obtain- 
ing an  evenly  color,  than  dyeing  in  the  cold ;  the  reason  of  which  may  be  found  in  the 
following  facts  :— The  air  adhering  to  the  surface  of  stuffs,  and  that  interposed  between 
the  fibres  of  their  constituent  yarns,  is  more  easily  extricated  in  a  hot  bath  than  a  cold 
one,  and  Ihus  allows  the  dye  liquor  to  penetrate  more  easily  into  their  interior :  in  the 
second  place,  the  currents  which  take  place  in  a  hot  bath,  and  which  tend  incessantly  to 
render  its  contents  uniform,  by  renewing  continually  the  strata  of  liquid  in  contact  with 
the  stuff,  contribute  mainly  to  render  the  dyeing  evenly.  In  cold  dyeins:,  it  is  necessary 
to  3tir  up  the  bath  from  time  to  time  :  and  when  goods  are  first  put  in,  they  must  he  care- 
fully dipped,  then  taken  out,  pressed,  and  wrung,  several  times  in  succession  till  they  be 
uniformly  moistened. 

The  mechanical  relations  are  to  be  found  in  the  apparatus  employed  for  wincing, 
sh-mg,  and  pressing  the  goods,  as  we  have  described  under  Calico  Printing  and 
Bandana.  The  hydraulic  relations  refer  to  the  wash-wheels  and  other  similar  ap- 
paratus, of  which  an  account  is  given  under  the  same  articles.      The  optical  relations 

39 


608 


DYEING. 


have  been  already  considered.    In  the  sequel  of  this  article  an  antomatic  dyeing  vat  wiJ 
be  described. 

The  extracts  of  solutions  of  native  dye-stufis  may  be  divided  into  two  classes,  in  refer- 
ence to  their  habitudes  with  the  oxygen  of  the  atmosphere ;  such  as  continue  essentially 
unaltered  in  the  air,  and  such  as  sufler  oxydalion,  and  thereby  precipitate  a  determinate 
coloring  matter.  The  dyes  contained  in  the  watery  infusions  of  the  different  vegetable 
and  animal  substances  which  do  not  belong  to  the  second  class,  are  feebly  attached  to 
their  solvents,  and  quit  them  readily  for  any  other  bodies  that  possess  an  attraction  foi 
them.  On  this  principle,  a  decoction  of  cochineal,  logwood,  brazil  wood,  or  a  solution 
of  sulphate  of  indiso,  by  digestion  with  powdered  bone  black,  lose  their  color,  in  conse* 
quence  of  the  coloring  particles  combining  by  a  kind  of  capillary  attraction  with  the 
porous  carbon,  without  undergoing  any  change.  The  same  thing  happens  when  well- 
scoured  wool  is  steeped  in  such  colored  liquids ;  and  the  color  which  the  wool  assumes 
by  its  attraction  for  the  dye,  is,  with  regard  to  most  of  the  above  colored  solutions,  but 
feeble  and  fugitive,  since  the  dye  may  be  again  abstracted  by  copious  washing  vrith  simple 
water,  whose  attractive  force  therefore  overcomes  that  of  the  wool.  The  aiu  of  a  high 
temperature,  indeed,  is  requisite  for  the  abstraction  of  the  color  from  the  wool  and  the 
bone-black,  probably  by  enlarging  the  size  of  the  pores,  and  increasing  the  solvent  power 
of  the  water. 

Those  dye-baths,  on  the  contrary,  whose  coloring  matter  is  of  the  nature  of  extractive 
Cr  apotheme,  form  a  faster  combination  with  stuffs.  Thus  the  yellow,  fawn,  and  brown 
dyes,  which  contain  tannin  and  extractive,  become  oxygenated  by  contact  of  air,  and  in- 
soluble in  water ;  by  which  means  they  can  impart  a  durable  dye.  When  wool  is  impreg- 
nated with  decoctions  of  thai  kind,  its  pores  get  charged  by  capillarity,  and  when  the  liquid 
becomes  oxygenated,  they  remam  filled  with  a  color  now  become  insoluble  in  water.  A 
similar  change  to  insolubility  ensues  when  the  yellow  liquor  of  the  indigo  vat  getsoxydized 
in  the  pores  of  cotton  and  wool,  into  which  it  had  been  introduced  in  a  fluid  state.  The 
same  change  occurs  when  protosulphate  of  iron  is  converted  into  persulphate,  with  the 
deposition  of  an  insoluble  peroxyde  in  the  substance  of  the  stuff.  The  change  here 
effected  by  oxydation  can,  in  other  circumstances,  be  produced  by  acids  which  have  the 
power  of  precipitating  the  dye-stuff  in  an  insoluble  state,  as  happens  with  decoction  of 
fustic. 

Hence  we  perceive  that  the  dyeing  of  fast  colors  rests  upon  the  principle,  that  the 
colors  dissolved  in  the  vat,  during  their  union  with  the  stuff,  should  suffer  such  a  change 
as  to  become  insoluble  in  their  former  menstruum.  The  more  this  dye,  as  altered  in  its 
union  with  the  stuff,  can  resist  other  menstrua  or  agents,  the  faster  it  will  be.  This  is 
the  essential  difference  between  dyeing  and  painting ;  or  applying  a  coat  of  pigment  de- 
void of  any  true  affinity  for  the  surface. 

If  we  mix  a  clear  infusion  of  a  dye  with  a  small  quantity  of  a  solution  of  an  earthy 
or  metallic  salt,  both  in  water,  the  limpid  liquids  soon  become  turbid,  and  there  grad- 
ually subsides  sooner  or  later,  according  to  the  nature  of  the  mixture,  a  colored 
precipitate,  consisting  of  the  altered  dye  united  with  a  basic  or  subsalt.  In  this  com- 
pound the  coloring  matter  seems  to  actr  the  part  of  an  acid,  which  is  saturated  by  a 
small  quantity  of  the  basis,  or  in  its  acid  relationship  is  feeble,  so  that  it  c  in  also 
combine  with  acids,  being  in  reference  to  them  a  base.  The  decomposition  of  a  salt,  as 
alum,  by  dyes,  is  effected  principally  through  the  formation  of  an  insoluble  subsalt, 
with  which  the  color  combines,  while  a  supersalt  remains  in  the  bath,  and  modifies,  by 
its  solvent  refaction,  the  shade  of  the  dyed  stuff.  Dyed  stuffs  may  be  considered  as 
composed  of  the  fibrous  body  intimately  associated  with  the  coloring  matter,  the  oxyde, 
and  acid,  all  three  constituting  a  compound  salt.  Many  persons  have  erroneously 
imagined,  that  dyed  goods  contained  none  of  the  acid  employed  in  the  dye  bath ;  but 
they  forget  that  even  potash  added  to  alum  does  not  throw  down  the  pure  earthy  basis, 
but  a  subsalt ;  and  they  should  not  ascribe  to  coloring  matter  a  power  of  decomposition 
8t  all  approaching  to  that  of  an  alkali.  Salts,  containing  stro»g  acids,  saturate  a  very 
large  quantity  of  coloring  matter,  in  proportion  to  their  place  in  the  scale  of  chemicid 
equivalents.  Mere  bases,  such  as  pure  alumina,  and  pure  oxyde  of  tin,  have  no  power 
of  precipitating  coloring  matter ;  when  they  seem  to  do  so,  they  always  contain  some 
acid. 

Such  salts,  therefore,  as  have  a  tendency  to  pass  readily  into  the  basic  state,  are  pecu- 
liarly adapted  to  act  as  mordants  in  dyeing,  and  to  form  colored  lakes.  Magnesia  alfords 
as  fine  a  white  powder  as  alumina,  and  answers  equally  well  to  dilute  lakes,  but  its 
soluble  salts  cannot  be  employed  to  form  lakes,  because  they  do  not  pass  into  the  basic 
state.  This  illustration  is  calculated  to  throw  much  light  upon  dyeing  processes  in 
general. 

The  color  of  the  lake  depends  very  much  upon  the  nature  of  the  acid,  and  the 
basis  of  the  precipitating  salt.  If  it  be  white,  like  alumina  and  oxyde  of  tin,  the  lake 
vill  have,  more  or  less,  the  color  of  the  dye,  but  brightened  by  the  reflection  of  white 


DYEING. 


609 


fight  from  the  basis ;  while  the  difference  of  the  acid  occasions  a  difference  in  the  hue. 
The  colored  bases  impart  more  or  less  of  their  color  to  the  lakes,  not  merely  in  virtue  of 
Uicir  own  tints,  but  of  their  chemical  action  upon  the  dye. 

Upon  these  principles  a  crinison  precipitate  is  obtained  from  infusions  of  cochineal  by 
alum  and  salt  of  tm,  wh-ch  becomes  scarlet  by  the  addition  of  tartar;  by  acetate  of 
ead,  a  violet  blue  precipitate  is  obtained,  which  is  durable  in  the  air;  by  muriate  of 
lime,  a  pmk  brown  precipitate  falls  which  soon  becomes  black,  and  at  last  dirty  green: 
by  the  solution  of  a  ferruginous  salt,  the  precipiutes  are  dark  violet  and  black;  and 
J^  like  manner,  all  other  salts  with  earthy  or  metallic  bases,  afford  diversities  of  shade 
•rith  cochineal.    If  this  dye  stuff  be  dissolved  in  weak  water  of  ammonia,  and  be  pre- 

Wn^f.'"''^  ^'T^  ""f  ^'^1'  ^  ^'"'^  ^?^'.  ''  °^^'"«^'  ^hich,  after  some  time!  wfu 
become  green  on  the  surface  by  contact  of  air,  but  violet  and  blie  beneath  Hence  it 
appears,  that  the  shade  of  color  of  a  lake  depends  upon  theTgree  of  oxvdlfron  or 
change  of  the  color  caused  by  the  acid  of  the  precipitating  salt,  u^=k  thele^ee  of  ox?! 
dation  or  color  of  the  oxyde  which  enters  into  union  with  the  dye,\nd  upon  its  quantU^ 
in  reference  to  that  of  the  coloring  principle.  J  »  «•  "  "P""  "s  quanmy 

Such  lakes  are  the  difficultly  soluble  salts  which  constitute  the  dyein*'  materials  of 
stuffs.  Their  particles,  however,  for  the  purposes  of  dyeing,  must  exis^in  a  state  of 
extremely  fine  division  in  the  bath  liquor,  in  order  that  they  may  pLe^rate  alon-  wfth  it 
into  the  mmule  pores  of  textile  fibres,  and  fill  the  cavities  obse^^ed  by  mean!  of  the 
microscope  m  the  filaments  of  wool,  silk,  cotton,  and  flax.  I  have  exainLTthese  stiS-s 
with  an  achromatic  microscope,  and  find  that  when  they  are  properly  dyed  with  fast  ^ 
ors  the  interior  of  their  tubular  texture  is  filled,  or  lined  at  least,  with  coSg  matJ^" 
)^rn  .  «l  ^^^^  '*'"'^''''  ^^^  *^^^°""^  P^*"^^^^^^'  s«  finely  'I'vided  that  they  caTpa^ 
i^„?L  fl  '"?"  f '^7'  "  T  ''P"l''.  f  ^y^^"^ '  ^"^  '^  the  infusion  mixed  whh  Us  mo^ 
dant  be  flocculenl  and  ready  to  subside,  it  is  unfit  for  the  purpose.  In  the  latter  T^e 
the  ingredients  of  the  dye  have  already  become  aggregated  intrcompoundst^coherlj 
and  too  gross  for  entering  into  combination  with  fibrous  stuffs.  Extractive  matter  and 
tonnin  are  particularly  liable  to  a  change  of  this  kind,  by  the  prolonged  acUon  of  heaUa 

^?h  wh.  ^'"'?  "'fK'.K"  "^"""  ^.^^"^^^"  °^  *  ^^^«""&  °^^"e^  affords  ruseful  dye 
baUi   when  m.xed  with  the  solution  of  a  salt  having  an  earthy  or  metallic  basis 

These  circumstances,  which  are  of  frequent  occurrence  in  the  dye-house   render  it 

necessary  always  to  have  the  laky  matter  in  a  somewhat  soluble  condition   and  to  effect 

us  precipitation  within  the  pores  of  the  stuffs,  by  previously  imprTgna  ng  them  with  SJe 

salme  solutions  by  the  aid  of  heat,  which  facilitates  their  iniroductfon.     " 

^\iL^  """i:  ?i  u  *PP^'^  ^°  *"y  ^^"^'  ^^^  portion  of  it  remaining  upon  the  su-face 
of  the  fibres  should  be  removed;  since,  by  its  combination  with  the  color?n?  matter  h 
would  be  apt  to  form  an  external  crust  of  mere  pigment,  which  woSrblLkuDJhi 

Z2:^T''  '""'cTr^^  S^  ^'!  ^'^^^  ^^^  ^»^«"«'-'  «"d  also  exCst  to  no  purple 
the  dye  ng  power  of  the  bath.  For  this  reason  the  stuffs,  after  the  applicat"onTf^e 
mordarit,  are  dramed,  squeezed,  washed,  and  sometimes  (particularly  witrcotton  and 
Imen,  m  calico  printing)  even  hard  dried  in  a  hot  stove. 

The  saline  mordants,  moreover,  should  not  in  general  possess  the  crystallizine  nronertr 
jn  any  considerable  degree,  as  this  opposes  their  affinity  of  composition  for  Uiecforh%  J 
this  account  the  deliquescent  acetates  of  iron  and  alumina  are  more  ready  o  aid  the 
dyeing  of  cotton  than  copperas  and  alum.  ^  ® 

Alum  is  the  great  mordant  employed  in  wool  dyeinff.     It  is  freouentlv  r?;cc/.i,r^  • 
water,  holding  tartar  equal  to  one  fourth  the  weight' of  Ike  alum  in'S^^^^^ 
addition  Its  tendency  to  crystallize  is  diminished,  and  the  resulting  color  Tbri/htTn^ 
The  alum  and  tartar  combine  with  the  stuff  without  suffering  any  chan4    and^: 
decomposed  only  by  the  action  of  the  coloring  matters  in  the  dve  bath      Th^  «in^ 
eTLt:^saltt'"'''  ^H  "'^'""^  -<i  aniearthy  baslfth'/Ut'te  oT'^otasT p^rSl 
^uld  ^l?^\     Z^-    }^'.  '"J^/l^"'-    "'°'^'  '^  *  ^"^P^ate  of  alumina  free  fromlZ 
could  be  readily  obtained,  it  would  prove  a  preferable  mordant  to  alum.     It  is  also  nrX 
able,  for  the  reasons  above  assigned,  that  soda  alum,  a  salt  much  less  mio  crZalUze 
than  potash  or  ammonia  alum,  would  suit  the  dver  vpw  w*.ll      Tn  Vr^Jl  ♦  crjstauize 

tendency  of  common  alum  to  crystallize  Vnd  to  ^o^^eTs^^ 
ctaVor  sella'!'  '"'  °'  '^  ""^^''  "'  ^^^"^^  ^^  ^''^'  ^  '^  sll.Z^r  ZV^^^^^^^^ 

We  shall  conclude  this  account  of  the  general  principles  of  dyeing,  with  Mr.  Delaval's 
observations  on   he  nature  of  dyes,  and  a  list  ,f  the  different  subst^ices  used  in  dyekg 
in  reference  to  the  colors  produced  by  them.  ">eia^. 

Sir  Isaac  Newton  supposed  colored  matters  to  reflect  the  rays  of  lic^ht  •  some  bodie. 

tL  Id  vol  ^r'.K  Vif  °"  -^  '^J'^u^  ""S  ^^^'''  '^o^o^-  Mr.  Delaval,  however,  proved,  S 
^  2d  vol.  of  the  «  Memoirs  of  the  Philosophical  and  Literary  Society  of  Manchester^ 
that,  « in  transparent  colored  substances,  the  coloring  substince  dL  not  reflet  «n, 


610 


DYEING. 


DYEING. 


611 


! 
51 


light ;  anc  that  when,  by  intercepting  the  light  which  was  transmitted,  it  is  hindered 
from  passing  through  substances,  they  do  not  vary  from  their  former  color  to  any  otlier 
color  but  become  entirely  black  ;"  and  he  instances  a  considerable  number  of  colored 
liquors,  none  of  them  endued  with  reflective  powers,  which,  when  seen  by  transmitted 
light,  appeared  severally  in  their  true  colors ;  but  all  of  them,  when  seen  by  incident 
light,  appeared  black ;  which  is  also  the  case  of  black  cherries,  black  currants,  black 
berries,  &c.,  the  juices  of  which  appeared  red  when  spread  on  a  white  ground,  or  other- 
wise viewed  by  transmitted  instead  of  incident  light ;  and  he  concludes,  that  bleached 
linen,  &c.,  "  when  dyed  or  painted  with  vegetable  colors,  do  not  differ  in  their  manner 
of  actinff  on  the  rays  of  light,  from  natural  vegetable  bodies ;  both  yielding  their  colors 
by  transmitting  through  the  transparent  colored  matter  the  light  which  is  reflected  from 
the  white  ground :"  it  being  apparent,  from  difl'erent  experiments,  "  that  no  reflecting 
power  resides  in  any  of  their  components,  except  in  their  white  matter  only,"  and  that 
« transparent  colored  substances,  placed  in  situations  by  which  transmission  of  light 
through  them  is  intercepted,  exhibit  no  color,  but  become  entirely  black." 

The  art  of  dyeing,  therefore,  (according  to  Mr.  Delaval,)  "consists  principally  in  cover- 
ing white  substances,  from  which  light  is  strongly  reflected,  with  transparent  colored 
media,  which,  according  to  their  several  colors,  transmit  more  or  less  copiously  the  rays 
reflected  from  the  white,"  since  "  the  transparent  media  themselves  reflect  no  light;  and 
it  is  evident  that  if  they  yielded  their  colors  by  reflecting,  instead  of  transmitting  the 
rays,  the  whiteness  or  color  of  the  ground  on  which  they  are  applied,  would  not  in  any- 
wise alter  or  aflfect  the  colors  which  they  exhibit." 

But  when  any  opaque  basis  is  interposed,  the  reflection  is  doubtless  made  by  it,  rather 
than  by  the  substance  of  the  dyed  wool,  silk,  &c.,  and  more  especially  when  such  basis 
consists  of  the  white  earth  of  alum,  or  the  white  oxyde  of  tin ;  which,  by  their  strong 
reflective  powers,  greatly  augment  the  lustre  of  colors.  There  are,  moreover,  some 
opaque  coloring  matters,  particularly  the  acetous,  and  other  solutions  of  iron,  used  to 
stain  linen,  cotton,  &c.,  which  must  necessarily  themselves  reflect,  instead  of  Uansmit- 
ting  the  light  by  which  their  colors  are  made  perceptible. 

The  compound  or  mixed  colors,  are  such  as  result  from  the  combination  of  two  diflTcr- 
cntly  colored  dye  stuffs,  or  from  dyeing  stufl's  with  one  color,  and  then  with  another. 
The  simple  colors  of  the  dyer  are  red,  yellow,  blue,  and  black,  with  which,  when  skil- 
fully  blended,  he  can  produce  every  variety  of  tint.  Perhaps  the  dun  or  fawn  col<w 
might  be  added  to  the  above,  as  it  is  directly  obtained  from  a  great  many  vegetable  sub- 
ctftncpg 

1.  Red  with  yellow,  produces  orange ;  a  color  which,  upon  wool,  is  given  usually  with 
the  spent  scarlet  bath.  To  this  shade  may  be  referred  flame  color,  pomegranate,  capu- 
chin, prawn,  jonquil,  cassis,  chamois,  cafe  au  laity  aurora,  marigold,  orange  peel,  mor- 
dores,  cinnamon,  gold,  &c.  Snufi",  chestnut,  musk,  and  other  shades  are  produced  by 
substituting  walnut  peels  or  sumach  for  bright  yellow.  If  a  little  blue  be  added  to  orange, 
an  olive  is  obtained.  The  only  direct  orange  dyes  are  annotto,  and  subchromate  of  lead ; 
see  Silk  and  Wool  Dyeing. 

2.  Red  with  blue  produces  purple,  violet,  lilach,  pigeon's  neck,  mallow,  peach-blossom, 
bleu  de  roi,  lint-blossom,  amaranth. 

3.  Red  with  black  ;  brown,  chocolate,  marone,  &c. 

4.  Yellow  with  blue ;  green  of  a  great  variety  of  shades,  such  as  nascent  green,  gay 
green,  grass  green,  spring  green,  laurel  green,  sea  green,  celadon  green,  parrot  green, 
cabbage  green,  apple  green,  duck  green.  .  j  c  •     j- 

5.  Mixtures  of  colors,  three  and  three,  and  four  and  four,  produce  an  indefinite  diva 
sity  of  tints ;  thus  red,  yellow,  and  blue,  form  brown  olives,  and  greenish  grays ;  in 
which  the  blue  dye  ought  always  to  be  first  given,  lest  the  indigo  vat  should  be  soiled  by 
other  colors.  Red,  yellow,  and  gray,  (which  is  a  gradation  of  black,)  give  the  dead-leaf 
tint,  as  well  as  dark  orange,  snufi*  color,  &c.  Red,  blue,  and  gray,  give  a  vast  variety 
of  shades ;  as  lead  gray,  slate  gray,  wood-pigeon  gray,  and  other  colors,  too  numerous  to 
specify.     See  Brown  Dye. 

The  following  list  of  dyes,  and  the  coloring  substances  which  produce  them,  may  prove 

useful.  1.       1         J 

Hed.    Cochineal,  kermes,  lac,  madder,  archil,  carthamus  or  safflower,  brazil  wood. 

logwood,  periodide  of  mercury,  alkanet. 

Yellow.  Quercitron,  weld,  fustic,  (yellow  wood,)  annotto,  sawwort,  dyer's  broom,  tur- 
meric,  fustet,  (rhus  cotinus,)  Persian  and  Avignon  berries,  {rhamnus  iiifectorius,)  willow, 
peroxyde  of  iron ;  chromate  of  lead,  (chrome  yellow,)  sulphuret  of  arsenic,  hydrosul- 
phuret  of  antimony ;  nitric  acid  on  silk.  j     •  u 

Blue,    Indigo,  woad  or  pastel,  Prussian  blue,  turnsole  or  litmus,  logwood  with  a  salt 

cf  eopper. 


\ 


Black,    Galls,  sumach,  logwood,  walnut  peels,  and  other  vegetables  which  contain 
tannin  and  gallic  acid,  along  with  ferruginous  mordants.     The  anacardium  of  India. 

Green.     These  are  produced  by  the  blue  and  yellow  dyes  skilfully  combined ;  with  the 
exception  of  the  chrome  green,  and  perhaps  the  copper  green  of  Schweinfurt. 

Orange.     Annotto,  and  mixtures  of  red  and  yellow  dyes ;  subchromate  of  lead. 

Brown.    See  the  remarks  at  the  beginning  of  this  article ;  Brown  in  its  alphabetical 
place ;  Calico  Printing,  Catechu,  and  Manganese. 

Fawn,  Dun,  or  Root.     Walnut  peels,  sumach,  birch-tree,  henna,  sandal  wood.      See 
Calico  Printing,  for  a  great  variety  of  these  dyes. 

Figs.  469  and  470  represent  in  a  cross  and  longitudinal  section  the  automatic  dyeing 
tteam  copper,  si  generally  employed  in  the  well-appointed  factories  of  Lancashire. 

A  is  the  long  reel,  composed  at  each  end  of  six 
radial  iron  arms  or  spokes,  bound  at  their  outer  ex- 
tremities with  a  six-sided  wooden  frame;  these  two 
terminal  hexagons  are  connected  by  long  wooden 
laths,  seen  above  and  below  a  in  fig.  470.  t  shows 
the  sloping  border  or  ledge  of  the  copper,  b  and  c 
are  rollers  laid  horizontally,  for  facilitating  the  con- 
tinuous motion  of  the  series  of  pieces  of  goods 
stitched  together  into  an  endless  web,  which  are 
made  to  travel  by  the  incessant  rotations  of  the  reel. 
Immediately  above  the  roller  b  in  fig.  469,  all  the 
spare  foldings  of  the  web  are  seen  resting  upon  the 
sloping  wooden  grating,  which  guides  them  onwards 
in  the  direction  indicated  by  the  arrow.  The  dye 
stufis  are  put  within  the  middle  grating,  like  a  hen- 
coop, marked  g.  Each  dopper  is  6  feet  long,  3|  feet 
wide,  3 1  feet  deep,  exclusive  of  the  top  ledge,  9 
inches  high.  Such  steam  coppers  are  usually  erected 
in  pairs,  and  moved  by  a  common  horizontal  bevel 
wheel  seen  at  d  in  fig.  470,  fixed  upon  a  vertical  shaft. 


IV 


K 


shiflcd  into  gear  by  a  wheel  at  its  top,  with  one  of  the  driving  shafts  of  the  factory.  Upon 
each  side  of  d,  the  two  steam  pipes  for  supplying  the  right  and  left  hand  coppers  are 
seen ;  each  provided  with  a  stop  cock  for  admitting,  regulating,  or  cutting  ofi"  the  steam. 
These  steam  pipes  descend  at  e  e,  the  horizontal  branch  having  sever^  orifices  in  its 
upper  surface.  The  horizontal  shafl  in  a  line  with  the  axes  of  the  reels,  and  which 
turns  them,  is  furnished  upon  each  side  with  a  clutch  for  putting  either  of  the  reels  into 
or  out  of  gear,  that  is  to  say,  setting  it  a  going,  or  at  rest,' in  a  moment  by  the  touch  of  a 
forked  lever. 

The  steam  pipe  of  distribution  e  lies  horizontally  near  the  bottom  of  the  middle  coop, 
M  shown  under  g  in  fig.  469,  and  sends  up  the  steam  through  its  numerous  orifices, 
among  the  dye-stuflfs  and  water  by  which  it  is  covered.     Thus  the  infusion  or  decoo- 


612 


EAU  DE  COLOGNE. 


EBULLITION. 


613 


Ml 


tion  is  continually  advancing  in  the  copper,  during  the  incessant  locomotion  of  the 
endless  web.  The  horizontal  pipe  traverses  the  copper  from  end  to  end,  and  is  not 
stopped  short  in  the  middle.  Each  of  these  coppers  can  receive  two,  three,  or  more 
parallel  pieces  of  goods  at  a  time,  the  reel  and  copper  being  divided  into  so  many  com- 
partments by  transverse  wooden  spars. 


E. 


EARTHS.  (Terres,  Fr. ;  Erden,  Germ.)  Modern  science  has  demonstrated  that  the 
substances  called  primitive  earths,  and  which  prior  to  the  great  electro-chemical  career 
of  Sir  H.  Davy,  were  deemed  to  be  elementary  matter,  are  nil  compounds  of  certain 
metallic  bases  and  oxygen,  with  the  exception  of  silica,  whose  base,  silicon,  being  analo- 
gous to  boron,  has  led  that  compound  to  be  regarded  as  an  acid ;  a  title  characteristic 
of  the  part  it  extensively  performs  in  neutralizing  alkaline  bodies,  in  mineral  nature, 
and  in  the  processes  of  art.  Four  of  the  earths,  when  pure,  possess  decided  alkaline 
properties,  being  more  or  less  soluble  in  water,  having  (at  least  3  of  them)  an  acrid 
alkaline  taste,  changing  the  purple  infusion  of  red  cabbage  to  green,  most  readily  satu- 
rating the  acids,  and  affording  thereby  neutro-saline  crystals.  These  four  are  baryta, 
«trontia,  lime  (calcia),  magnesia.  The  earths  proper  are  five  in  number;  alumina^ 
glucina,  yttria,  zirconia,  and  thorina.  These  do  not  change  the  color  of  infusion  of  cab- 
bage or  tincture  of  litmus,  do  not  readily  neutralize  acidity,  and  are  quite  insoluble  in 
water.  The  alkalis  are  soluble  in  water,  even  when  carbonated ;  a  property  which 
distinguishes  them  from  the  alkaline  earths.  Lithia  must  for  this  reason  be  considei*e(1 
to  be  an  alkali.     See  the  above  substances  in  their  alphabetical  places. 

EAU  DE  COLOGNR  This  well-known  perfume  is  a  solution  of  different  volatile 
oils  in  pure  strong  spirit  The  principal  condition  for  the  preparation  of  a  fine  water,  is 
the  employment  of  a  spirit  quite  devoid  of  fusel-oil  (oil  of  grain),  and  of  all  foreign  odor. 

In  respect  to  the  proportion  and  kind  of  oils  employed,  we  have  numerous  formulse. 
It  is  of  importance  that  these  oils,  which  are  usually  purchased  of  the  druggists  of  the 
south  of  France,  should  be  of  the  finest  quality,  and  that  no  oil  should  be  used  in  suffi- 
cient quantity  to  allow  of  its  peculiar  odor  being  recognisable  in  the  mixture.  The 
oils  are  to  be  dissolved  in  spirit,  and  the  mixture  allowed  to  stand  for  some  weeks  (or 
still  better  for  some  months)  to  improve  its  odor.  Distillation  does  not  effect  this;  on 
the  contrary  a  fresh  distilled  water  requires  to  be  kept  a  much  longer  time.  Distilla- 
tion is  indeed  objectionable,  for  on  account  of  the  great  volatility  of  the  spirit,  the  oils 
in  part  remain  behind  in  the  still.  Distillation  can  improve  the  odor  only  when  the 
less  volatile  oil  has  been  used  in  too  great  a  quantity,  and  we  wish  to  obtain  a  better 
proportion.  Before  all  things,  we  should  employ  a  pure,  old,  strong  spirit,  and  not  too 
much  of,  nor  a  too  strongly  smelling  oil. 

The  different  sorts  of  volatile  oil  which  are  obtained  from  varieties  of  citrons,  oranges, 
and  lemons,  in  different  states  of  maturity,  are  the  most  important ;  and,  therefore,  it 
is  most  important  to  ascertain  their  purity  and  goodness. 

Forster  gives  the  following  formula  for  the  preparation  of  a  fine  eau  de  Cologne : 
Take  of  rectified  spirit  82  per  cent  of  Tralles  (=8p.  gr.  0*855),  6  (wine)  quarts ;  essence 
of  pranges,  essence  of  bergamot,  essence  of  citron,  essence  of  limette,  and  essence  of 
petita  grains,  of  each,  ^j ;  essence  of  cedro,  essence  of  cedrat  essence  de  Portugal,  and 
essence  de  neroli,  of  each  ^ss;  oil  of  rosemary,  3'j;  and  oil  of  thyme,  Zy 

Otto  gives  the  following  formula  for  a  good  eau  de  Cologne :  Rectified  spirit  of  86 

Eer  cent  of  Tralles  (=0'846  sp.  gr.),  200  (wine)  quarts;  oil  of  citrons,  lb.  iv;  oil  of 
ergamot  lb.  ij ;  oil  of  neroli,  fib. ;  oil  of  lavender,  lb.  ss;  oil  of  rosemary,  \  lb. ;  and 
spirit  of  ammonia,  |ss.     Mix.     Don't  distil. 

This  preparation  has  long  possessed  great  celebrity,  in  consequence  chiefly  of  the 
numerous  virtues  ascribed  to  it  by  its  venders;  and  is  resorted  to  by  many  votaries  of 
fashion  as  a  panacea  against  ailments  of  every  kind.  It  is,  however,  nothing  more 
than  aromatized  alcohol,  and  as  such,  an  agreeable  companion  of  the  toilet  Numerous 
fictitious  recipes  have  been  offered  for  preparing  eau  de  Cologne;  the  following  may 
be  reckoned  authentic,  having  been  imparted  by  "Farina  himself  to  a  friend. 

Take  60  gallons  of  silent  brandy;  sage,  and  thyme,  each  6  drachms;  balm-mint  and 
spearmint,  each  12  ounces ;  calamus  aromaticus,  4  drachms ;  root  of  angelica,  2  drachms 
camphor,  1  drachm ;  petals  of  roses  and  violets,  each  4  ounces ;  flowers  of  lavender,  2 
ounces ;  flowers  of  orange,  4  drachms ;  wormwood,  1  ounce ;  nutmegs,  cloves,  cassia, 
lignea,  mace,  each  4  drachms.  Two  oranges  and  two  lemons,  cut  in  pieces.  Allow  the 
whole  to  macerate  in  the  spirit  during  24  hours,  then  distil  off  40  gallons  by  the  heat 
of  a  water  bath.  Add  to  the  product : 
Essence  of  lemons,  of  cedrat,  of  balm-mint^  of  lavender,  each  1  ounce  4  drachms; 


neroli  and  essence  of  the  seed  of  anthos,  each  4  drachms ;  essence  of  jasmin,  1  ounce ; 
of  bergamot  12  ounces.     Filter  and  preserve  for  use.  v    *u    f  n  «,;««  ..^/.ir^. 

Cadet  de  Gassineourt  has  proposed  to  prepare  eau  de  Cologne  by  the  following  recipe. 
Take  alcohol  at  32°  B.,  2  quarts;  neroli,  essence  of  cedrat,  of  orange,  of  lemon  ot  ber- 
gamot,  of  rosemary,  each  24  drops;  add  2  drachms  of  the  seeds  of  lesser  cardaniom^ 
distil  by  the  heat  of  a  water  bath  a  pint  and  a  half.  When  prepared  as  thus  by  simple 
mixture  of  essences  without  distillation,  it  is  never  so  good.      ,     ,       ,  .       .       t 

EAU  DE  LUCE,  is  a  compound  formed  of  the  distilled  oil  of  amber  and  water  of 

ammonia.  _        ^     ,,_        .,      i    ..  e  «-.  ^^^„ 

EBULLITION.     (Eng.  and  Fr.;    Kochen,  Germ.)     When  the  bottom  of  an.op«n 
vessel  containin<r  water  is  exposed  to  heat,  the  lowest  stratum  of  fluid  immediately 
expands,  becomes  therefore  specifically  lighter,  and  is  forced  upward  by  the  superior  gra- 
vity of  the  superincumbent  colder  and  heavier  particles.     The  heat  is  in  this  way  dittused 
through  the  whole  liquid  mass,  not  by  simple  communication  of  that  power  from  par- 
ticle to  particle  as  in  solids,  called  the  conduction  of  caloric,  but  by  a  translation  of  the 
several  particles  from  the  bottom  to  the  top,  and  the  top  to  the  bottom,  in  alternate 
succession.     This  is  denominated  the  carrying  power  of  fluids,  being  common  to  both 
liquid  and  gaseous  bodies.    These  internal  movements  may  be  rendered  very  conspic- 
uous and  instructive,  by  mingling  a  little  powdered  amber  with  water,  contained  in  a 
tall  glass  cylinder,  standing  upon  a  sand-bath.     A  column  of  the  heated  and  lighter 
particles  will  be  seen  ascending  near  the  axis  of  the  cylinder,  surrounded  by  a  hollow 
column  of  the  cooler  ones  descending  near  the  sides.    That  this  molecular  translation 
or  locomotion  is  almost  the  sole  mode  in  which  fluids  get  heated,  may  be  demonstrated 
by  placing  the  middle  of  a  pretty  long  glass  tube,  nearly  fiUed  with  water,  obliquely 
over  an  argand  flame.     The  upper  half  of  the  Mquid  will  soon  boU,  but  the  portion  under 
the  middle  will  continue  cool,  so  that  a  lump  of  ice  may  remain  for  a  considerable  time  at 
the  bottom.    When  the  heat  is  rapidly  applied,  the  liquid  is  thrown  into  agitation,  in 
consequence  of  elastic  vapor  being  suddenly  generated  at  the  bottom  of  the  vessel,  and 
being  as  suddenly  condensed  at  a  little  distance  above   it  by  the   surrounding   cold 
columns.     Thtte  alternate  expansions  and  contractions  of  volume  become  more  manifest 
as  the   liquid   becomes   hotter,  and   constitute   the   simmering  vibratory  sound  which 
is  the  prelude  of  ebullition.     The  whole  mass  being  now  heated  to  a  pitch  compatible 
with  its  permanent  elasticity,  becomes  turbulent  and   explosive  under  the  continued 
influence  of  fire,  and  emitting  more   or  less  copious  volumes   of  vapor,  is   said   to 
boil.     The  further   elevation   of   temperature,   by   the   influence   of  caloric,   becomes 
impossible  in   these   circumstances   with   almost  all   liquids,  because   the  vapor  car- 
ries off  from  them  as  much  heat  in  a  latent  state  as  they  are  capable  of  receiving  from 

the  fire.  .        .  ,    ,     ,  r    * 

The  temperature  at  which  liquids  boil  in  the  open  air  vanes  with  the  degree  ol  atmo- 
spheric pressure,  being  higher  as  that  is  increased,  and  lower  as  it  is  diminished.  Hence 
boiling  water  is  colder  by  some  degrees  in  bad  weather,  or  in  an  elevated  situation,  with 
a  depressed  barometer,  than  in  fine  weather,  or  at  the  kttom  of  a  coal-pit,  when  the 
barometer  is  elevated.  A  high  column  of  liquid,  also,  by  resisting  the  discharge 
of  the  steam,  raises  the  boiling  point.  In  ractto,  all  liquids  boil  at  a  temperature  about 
124*  F.  lower  than  under  the  average  atmospheric  pressure.  For  a  table  of  elasticities, 
see  Vapor.  Gay  Lussac  has  shown  that  liquids  are  converted  into  vapors  more  readily, 
or  with  less  turbulence,  when  they  are  in  contact  with  angular  or  irregular,  than 
with  smooth  surfaces ;  that  they  therefore  boil  at  a  heat  2?  F.  lower  in  metallic  than  in 
glass  vessels,  probably  owing  to  the  greater  polish  of  the  latter.  For  example,  if  into 
water  about  to  boil  in  a  glass  matrass,  iron  filings,  ground  glass,  or  any  other  insoluble 
powder  be  thrown,  such  a  brisk  ebullition  will  be  instantly  determined  as  will  sometimes 
throw  the  water  out  of  the  vessel ;  the  temperature  at  the  same  time  sinking  two  degrees 
F.  It  would  thence  appear  that  the  power  of  caloric,  like  that  of  electricity,  becomes 
concentrated  by  points. 

The  following  table  exhibits  the  boiling  heats,  by  Fahrenheit's  scale,  of  the  most  im- 
portant liquids  : — 


Ether,  specific  gravity  0-7365  at  48^ 
Carburet  of  sulphur 
Alcohol,  sp.  grav.  0-813  - 
Nitric  acid,  1*500  - 

Water      -  -  -  - 

gaturated  solution  of  Glauber  salt 


Urc 
Dalton 


Biot 
do.        do.  Acetate  of  lead      -  -  do. 

do.        do.  Sea  salt      -  -  -  do. 

do.        do.  Muriate  of  lime,    -  -         Ure 

do.        do.  do.  1  -At  water  2,   do. 

do.        do.  do.         35*5  +    do.  64*5,  do. 


1000 

113 

173-6 

210 

212 

213| 

215f 

224| 

285 

230 

235 


614 


EBULLITION  ALCOHOLMETER. 


EBULLITION  ALCOHOLMETER. 


615 


Saturated  solution  of  Muriate  of  lime  40-54- water  69  5  Ure 


Muriatic  acid,  sp.  gray.  1*094 

do.  do.  1-127 

Nitric  acid,  do.  1  -4^ 

do.  do.  1-30 

Rectified  petroleum 

Oil  of  turpentine 

Sulphuric  acid,  ep.  gray.  1-848 


do. 

do. 

do. 

do. 

do. 

do. 

do. 
Phosphorus 
Sulphur 
Linseed  oil 
Mercury 

do. 


do. 

do. 

da 

da 

da 

da 

do, 


1-810 

1-780 

1-700 

1-650 

1-620 

1-408 

1-300 


Baltoo, 

da 

do. 

do. 
Ure, 

do. 
Dal  ton, 

da 

da 

do. 

do. 

do. 

do. 

da 

do. 

do. 

do. 
Dulong, 
Crighton, 


Saturated   solution   of   Acetate  soda,  containing  60  per  cent  Griffiths! 


Nitrate  of  soda,  60 

Rochelle  salt,  90 

Nitre,  74 

Muriate  of  ammonia,      60 
Tartrate  of  potash,  68 

Muriate  of  soda,  30 

Sulphate  of  magnesia,  57-5 
Borax, 

Phosphate  of  soda, 
Carbonate  of  soda, 
Alum, 

Chlorate  of  potash, 
Sulphate  of  copper. 

Ebullition 


62-5 

? 

I 

62 

40 

45 

ALCOnOLMETER. 


do. 
do. 
do. 
do. 
do. 
da 
do. 
do. 
do. 
do. 
do. 
do. 
do. 
That 


the 


24a 

232 
222 
248 
236 
306 
316 
600 
473 
435 
374 
350 
290 
260 
240 
664 
670 
640 
66!^ 
656 
256 
246 
240 
238 
236 
234 
224 
222 
222 
222 
220 
220 
218 
216 
boiling 


temperature  of  water  is  increased  by  holding  neutro- 
saline  and  saccharine  substances  in  solution  has  been 
long  known,  and  has  been  the  subject  of  many  ex- 
penments,  made  partly  with  the  view  of  ascertaining 
from  that  temperature  the  proportion  of  the  salt  or 
sugar,  and  partly  with  the  view  of  obtaining  a  practi- 
cal liquid  bath.     But  it  seems  to  have  been  reserved 
for  the  Abbe  Brossard-Vidal,  of  Toulon,  to  have 
discovered  that  the  boiling  temperature  of  alcoholic 
liquors  is,  in  most  cases,  proportional  to  the  quantity 
of  alcohol,  irrespectively  of  the  quantity  of  neutro- 
saline  or  saccharine  matter  dissolved  in  them.   When, 
however,  such  a  quantity  of  dry  carbonate  of  potash* 
or  sugar,  is  added  to  a  spirituous  liquor  as  to  abl 
Btract  or  fix  in  the  solid  state  a  portion  of  the  water 
present,  then  the  boiling  temperature  of  that  mixture 
will  be  lowered  in  proportion  to  the  iioncentration 
of  the  alcohol,  instead  of  being  raised,  as  would  be 
the  case  with  water  so  mixed.    But,  generally  speak- 
ing, it  may  be  assumed  as  a  fact,  that  the  boiling 
point   of  an   alcoholic   liquor  is  not  altered   by   a 
moderate  addition  of  saline,  saccharine,  or  extractive 
matter.     On  this  principle,  M.  Brossard-Vidal  con- 
structed the  instrument  represented  in  fp.  471,  for 
determining  by  that  temperature  the  proportion  of 
alcohol  present.    His  chief  object  was  to  furnish  the 
revenue  boards  of  France  with  a  means  of  esti- 
mating directly  the  proportion  of  alcohol  in  wines, 
80  as  to  detect  the  too  common  practice  of  intro- 
ducing brandy  into  their  cities  and  towns  under  the 
naask  of  wine,  and  thereby  committing  a  fraud  upon 
the  octroi ;    as  the  duty  on  spirita  is  much  higher 
than  on  wines. 


The  above  instrument  consists  of  a  spirit-lamp,  surmounted  by  a  small  boiler,  into 
which  a  large  cylindric  glass  bulb  is  plunged,  having  an  upright  stem  of  such  calibre, 
that  the  quicksilver  contained  in  them  may,  by  its  expansion  and  ascent  when  heated, 
raise  before  it  a  little  glass  float  in  the  stem,  which  is  connected  by  a  thread  with  a  simi- 
lar glass  bead,  that  hangs  in  the  air.  The  thread  passes  round  a  pulley,  which  turning 
with  the  motion  of  the  beads  causes  the  index  to  move  along  the  graduated  circular 
scale.  The  numbers  on  this  scale  represent  per  centages  of  absolute  alcohol,  so  that 
the  number  opposite  to  which  the  index  stops,  when  the  liquor  in  the  cylinder  over 
the  lamp  boils  briskly,  denotes  the  per  centage  of  alcohol  in  it 

That  instrument  was  placed  in  my  hands  three  years  ago  by  Mr.  Field,  who  had 
obtained  a  patent  in  this  country  for  determining  thereby  the  strength  of  spirituous 
liquor&     I  have  made  a  great  many  experiments  on  the  boiling  points  of  alcohol  at 

various  successive  degrees  of  watery  dilution, 
and  verified  the  general  utility  of  the  contriv- 
ance; but  I  found  the  construction  of  the  in- 
strument subject  to  general  defects.  The  mass 
of  mercury  to  be  heated  in  the  large  bulb  was 
so  great  as  to  occasion  some  loss  of  alcohol  in 
the  course  of  the  experiment;  the  length  of  the 
thread  was  liable  to  be  affected  by  the  moisture 
of  the  air;  it  occasionally  failed  to  move  the 
pulley  with  sufficient  delicacy  on  account  of 
friction,  and  when  the  spirit  in  the  lamp  got 
heated  in  its  case,  it  flared  up  and  burned  the 
thread,  thus  rendering  the  apparatus  useless  till 
a  fresh  thread  was  experimentally  adjusted  to 
the  beads. 

On  these  accounts  I  renounced  the  construc- 
tion of  M.  Vidal,  and  adopted  the  more  simple 
and  direct  form  of  indication  represented  in 
Jig.  472. 

It  consists,  1,  of  a  flat  spirit-lamp  a,  sur- 
rounded by  a  saucer  for  containing  cold  water 
to  keep  the  lamp  cool,  should  many  experiments 
require  to  be  made  in  succession ;  2,  of  the 
boiler  B,  which  fits  by  its  bottom  cage  c,  upon 
the  case  of  the  lamp.  At  the  point  c,  is  seen 
the  edge  of  the  damper-plate  for  modifying  the 
flame  of  the  lamp,  or  extinguishing  it  when  the 
experiment  is  completed,  d  is  the  thermometer, 
made  with  a  very  minute  bore,  in  the  manner 

Dr  ^     ^     €flH  ^^   ^^^    B.ev.    Mr.    WoUaston's    instrument    for 
u              ll^"""""-— -^-"^  H  measuring   the   height   of    a   mountain   by   the 
■        X  H  boiling  point  of  water  on  its  summit     The  bot- 

X^^  j^  tom  of  the  scale  in  the  ebullition  thermometer, 

^ "^   is  marked  p  for  proof  on  the  left  side,  and  100 

(of  proof  spirit)  on  the  right  side.  It  corresponds  to  178-6  Fahr.  very  nearly,  or  the 
boiling  point  of  alcohol  of  0920  specific  gravity.  The  following  table  gives  the  boil- 
ing points  corresponding  to  the  indicated  densities: — 

Sneeific  ma.ril\ . 

U.  P. 


The  above  table  is  the  mean  of  a  great  many  experiments.  When  alcohol  is  stronger 
than  0-92,  or  the  excise  proof,  its  boiling  point  varies  too  little  with  its  progressive  in- 
crease of  strength,  to  render  that  test  applicable  in  practice.  In  fact  even  for  proof 
spirits,  or  spirits  approaching  in  strength  to  proof,  a  more  exact  indication  may  be  ob- 
tained by  diluting  tliem  with  their  own  bulk  of  water,  before  ascertaining  their 
•trength,  and  then  doubling  it 

The  boiling  point  of  any  alcoholic  liquor  is  apt  to  rise  if  the  heat  be  long-continued, 
and  thereby  to  lead  into  error  in  using  this  instrument  This  source  of  fallacy  may  be 
in  a  great  measure  avoided  by  adding  to  the  liquor  in  the  little  boiler  about  a  tea- 
spoonful  (thirty-five  grains)  of  common  culinary  salt  which  has  the  curious  effect  of 
arresting  the  mercury  in  the  thermometer  at  the  true  boiling  point  of  the  spirit,  wine, 


Temp.  Fahr. 

Specific  gravity. 

Temp.  Fahr. 

Specific  gravity. 

178-6 

-     0-9200     P. 

185-6 

-     0-9665     50  I 

179-75 

-    0-9321     10  U.  P. 

189-0 

-    0-9729     60 

180-4 

-    0-9420    20    „ 

191-80 

-    0-9786    70 

18100 

-    0.9516     30     „ 

196-4 

-    0-9850     80 

183-40 

-    0-960      40     „ 

202-0 

-    0-992       90 

616 


EBULLITION  ALCOHOLMETER. 


EBULLITION  ALCOHOLMETER. 


617 


i  .^ 


or  beer,  to  enable  a  correct  reading  to  be  had.  The  small  measure  marked  m,  holds 
the  requisite  quantity  of  salt 

The  thermometer  is  at  first  adjusted  to  an  atmospheric  pressure  of  29-6  inches. 
When  that  pressure  is  higher  or  lower,  both  water  and  alcohol  boil  at  a  somewhat 
higher  or  lower  temperature.  In  order  to  correct  the  error  which  would  hence  arise 
in  the  indications  of  this  instrument  under  different  states  of  the  weather,  a  barometri- 
cal equation  is  attached  by  means  of  the  subsidiary  scale  e,  to  the  thermometer  d 

Having  stated  the  principles  and  the  construction  of  the  ebullition  alcoholmeter  I 
shall  now  describe  the  mode  of  its  application.  * 

First — Light  the  spirit  lamp  a. 

Second.— charge  the  boiling  vessel  b,  with  the  liquid  to  be  tested  (to  within  an  inch 
of  the  top),  introducing  at  the  same  time  a  paper  of  the  powder :  then  place  the  vessel 
B  (the  damper  plate  being  withdrawn)  on  to  the  lamp  a. 

.u^v '"'^••7"^'^,^^®  thermometer  d  on  the  stem  attached  toB,  with  its  bulb  immersed  id 
the  liquid.     The  process  will  then  be  in  operation. 

The  barometrical  scale  indicated  on  the  thermometer  is  opposite  the  mean  boiling 
point  of  water  Prior  to  commencing  operations  for  the  day,  charge  the  boiler  b  with 
water  only,  and  fix  the  instrument  as  directed ;  when  the  water  boils  freely,  the  mercury 
will  become  stationary  in  the  stem  of  the  thermometer,  opposite  to  the  true  barometrt 
cal  indication  at  the  time.  Should  the  mercury  stand  at  the  line  295,  this  will  be  the 
height  of  the  barometer,  and  no  correction  will  be  required ;  but  should  it  stand  at  any 
other  line,  above  or  below,  then  the  various  boiling  points  will  bear  reference  to  that 
boiling  point 

In  testing  spirituous  or  fermented  liquors  of  any  kind,  when  the  mercury  begins  to 
rise  out  of  the  bulb  of  the  thermometer  into  the  stem,  push  the  damper-plate  half-way 
m  its  groove  to  moderate  the  heat  of  the  flame.  When  the  liquor  boils  freely,  the  mer- 
cury will  become  stationary  in  the  stem ;  and  opposite  to  its  indication,  on  the  left  the 
under-proof  per-centage  of  spirit  may  be  read  off  at  once,  if  the  barometer  stand  that 
day  at  29-5  inches;  while  on  the  right  hand  scale,  the  per  centage  of  proof  spirit  is 
shown ;  being  the  difference  of  the  former  number  from  100.  The  damper-plate  is  to 
be  immediately  pushed  home  to  extinguish  the  flame. 

The  alcoholmeter  will  by  itself  only  indicate  the  per  centage  of  alcohol  contained  in 
any  wine,  but  by  the  aid  of  the  hydrometer,  the  proportionate  quantity  of  saccharuro 
m  all  wines  may  be  readily  and  easily  determined.  The  hydrometer 'will  show  the 
specific  gravity  of  Ihe  liquid  upon  reference  to  table  No.  1,  annexed.  In  testing  a 
sample  of  wme,  first  take  the  specific  gravity,  and  suppose  it  to  be  989,  then  charge  the 
boiler  of  the  alcoholmeter  with  the  wine,  as  directed,  and  at  the  boiling  point  it  indi- 
cates  the  presence  of  alcohol  at  69-6  per  cenfP-  whose  specific  gravity  will  be  fonnd  to 

I?  u  ,\  /^"''^  ^^^^  ^""^^^^y  ^^0"  t^«  gravity  of  the  bulk,  or  989.  and  10  will  remain 
which  10  degrees  of  gravity,  upon  reference  to  the  wine  table,  will  be  found  to  represent 
25  lbs.  of  saccharine  or  attractive  matter  in  every  100  gallons,  combined  with  30  *  th 
gallons  of  proof  spirit  TU 

Sike's  hydrometer  will  only  show  the  sp.  gr.  of  liquids  lighter  than  water  (or  lOOOl 
and  for  wines  m  general  use,  the  gravities  being  lighter  than  that  article,  will  answer 
every  purpose;  but  there  are  wines  whose  gravities  are  heavier  than  water  such  as 
mountain  tent,  rich  Malagas,  lachrymre  Christi,  Ac,  to  embrace  which  additional  weiffhts 
to  the  hydrometer  will  be  required,  as  for  cordialized  spirits,  <fec.  In  testing  a  sample 
of  rich  mountain  its  sp.  gr.  was  found  to  be  1039.  or  39  degrees  heavier  than  water 
that  wine  at  the  boiling  point  indicated  the  alcohol  725  per  cent  "P;  but  980  sp  ct 
deducted  from  1039  leaves  69  degrees  of  sp.  gr. ;  against  59  of  the  wine  tables  will  be 
louna  147-5  or  147^  lbs.  of  saccharine  or  extractive  matter,  combined  with  27*  gallons 
of  proof  spirit  to  eveiy  100  gallons. 

Should  the  barometer  for  the  day  show  any  other  indication  above  or  below  the 
standard  of  29-5,  the  thermometer  scale  will  then  only  show  the  apparent  strength 
and  reference  must  be  had  to  the  small  ivory  indicator,  f,  it  being  the  counterpart  of 
the  barometrical  scale  of  the  thermometer;  thus  should  the  barometer  indicate  80, 
P  f  f  ^H,  u  ^^r  ^°^^<^?^^  ag^nst  the  boiling  point  of  the  liquid,  and  opposite  the  line  of 
29-5  will  be  found  the  true  strength. 

Example  \  Baronaeter  at  30.— Suppose  the  mercury  to  stop  at  the  boiling-point 
72'»P,  place 30  of  the  indicator  against  72  on  the  thermometer,  and  the  line  of  29-5  wiU 
cut  69-6  "P,  the  true  strength. 

Example  2  Barometer  at  29.— Suppose  the  mercury  to  stop  at  the  same  point,  72-p. 
place  29  of  the  indicator  against  72  on  the  thermometer,  and  the  line  29-5  will  cut 
74-3  "P,  the  true  strength. 

For  malted  Liquors— To  all  brewers  and  dealers  in  fermented  liquors,  the  principle 
by  Its  application,  will  supply  a  great  desideratum,  as  it  will  not  only  show  the  alcohol 
treated  in  the  wort  by  the  attenuation,  as  well  as  the  original  weight  of  the  wort  prior 


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ttammatdkm,Mt  «— . . 


618 


EBULLITION  ALCOHOLMETER. 
No.  2. 


EBULLITION  ALCOHOLMETER. 


619 


til 


TABLE,  showing  the  lbs.  of  Sugar  per  Gallon  in  Cordialized  Spirits,  with  Per-Centagea 
to  be  added  to  the  indicated  Strength,  per  the  Alcoholmeter. 


Difference  of 
Gravity. 

10 

15 

20 

25 

30 

35 

40 

45 

50 

Difference  of 
Gravity. 

4oz. 

6oz. 

8  oz. 

10  oz. 

12   oz. 

14  oz. 

oz. 

oz 

Libs,  of  Sugar 

or  25 

37i 

50 

62i 

75 

87J 

10 

1-2 

1-4 

Llbg.  of  Sugar 
per  Gallon. 

per  Gallon. 

to  100. 
1-6 

to  100. 

to  100. 

to  100. 

to  100. 

to  100. 

7-1 

8-1 

9-0 

Sp.    Grav. 

of  Spirit 

920 

Per  Cent, 
of  Spirit. 

Pf. 

2-5 

3-4 

4-4 

6-3 

6-2 

Per  Cent, 
of  Spirit. 

Pf. 

Sp.    Grar. 
of  Spirit. 

920 

923 

2-5 

1-6 

2-6 

3-3 

4-3 

5-2 

6-1 

6-9 

7-8 

8-8 

2-6 

923 

926 

6- 

1-5 

2-4 

3-2 

4-2 

6-0 

6-9 

6-8 

7-7 

8-6 

5- 

926 

929 

7-5 

1-5 

2-3 

3-2 

4-1 

4-9 

5-8 

6-6 

7-5 

8-4 

7-6 

929 

932 

10- 

1-4 

2-2 

31 

4-0 

4-8 

5-7 

6-5 

7-4 

8-2 

10- 

932 

935 

12-5 

1-4 

2-2 

3-1 

3-9 

4-7 

6-5 

6-3 

7-2 

8-0 

12-5 

935 

938 

15- 

1-4 

21 

3  0 

3-8 

4-6 

6-4 

6-2 

7-0 

7-8 

16- 

93S 

940 

17-5 

1-3 

21 

2-9 

3-7 

4-5 

6-3 

6-0 

6-8 

7-6 

17-5 

940 

943 

20- 

1-3 

2-0 

2-8 

3-6 

4-4 

5-2 

5-9 

6-7 

7-5 

20- 

943 

945 

22-5 

1-3 

2-0 

2-7 

3-5 

4-3 

5-0 

5-7 

6-5 

7-3 

22-5 

945 

948 

25* 

1-2 

1-9 

2-6 

3-4 

41 

4-8 

5-5 

6-3 

7-0 

25- 

948 

950 

27-5 

1-2 

1-9 

2-5 

3-3 

40 

4-7 

5-3 

6-1 

6-8 

27-5 

950 

952 

30- 

11 

1-8 

2-4 

3-1 

3-8 

4o 

5-1 

5-8 

6-5 

30- 

952 

954 

32-5 

M 

1-7 

2-3 

3-0 

3-6 

4-3 

4-8 

5-5 

6-2 

32-5 

954 

956 

36- 

1-0 

1-6 

2-2 

2-9 

3-5 

41 

4-6 

5-3 

6  0 

36- 

956 

958 

37-5 

10 

1-6 

2-1 

2-8 

3-4 

3-9 

4-4 

61 

6-8 

37-6 

958 

960 

40- 

•9 

1-5 

2  0 

2-7 

3-2 

3-8 

4-3 

4-9 

5-5 

40- 

960 

962 

42-5 

•9 

1*5 

2  0 

2-6 

3  1 

3-6 

4-1 

4*7 

6-3 

42-6 

962 

964 

45- 

•9 

1-4 

1-9 

2-5 

3-0 

3-5 

4-0 

4-6 

51 

45- 

964 

965 

47-5 

•8 

1-4 

1-9 

2-4 

2-9 

3-4 

3-9 

4-4 

4-9 

47-6 

965 

907 

60- 

•8 

1-3 

1-8 

2-3 

2-8 

3-3 

3-8 

4-3 

4-8 

50- 

967 

969 

52-5 

•7 

1-2 

1-7 

2-2 

2-6 

31 

3-6 

41 

4-5 

52-5 

969 

970 

55- 

•7 

1-2 

1-6 

2  0 

2-4 

2-9 

3-4 

3-8 

4-2 

55- 

970 

972 

67-5 

•6 

11 

1-5 

1-9 

2-2 

2-7 

3-1 

3-5 

3-9 

67-5 

972 

973 

60- 

•6 

10 

1-4 

1-8 

21 

2-5 

2-9 

3-3 

3-6 

60- 

973 

974 

62-5 

•6 

1-0 

1-3 

1-7 

2-0 

2-4 

2-7 

31 

3-4 

62-5 

974 

976 

65- 

•5 

•9 

1-2 

1-5 

1-8 

2-2 

2-5 

2-8 

31 

65- 

976 

977 

67-5 

•5 

•8 

11 

1-4 

1-7 

2-0 

2-3 

2-6 

2-9 

67-5 

977 

979 

70- 

•4 

•7 

1-0 

1-3 

1-5 

1-8 

21 

2-4 

2-6 

70- 

979 

980 

72-5 

•4 

•7 

•9 

1-1 

1-3 

1-6 

1-9 

21 

2-3 

72-6 

980 

982 

75- 

•3 

•6 

•8 

1-0 

1-2 

1-4 

1-6 

1-8 

2-0 

75- 

982 

983 

77-5 

•3 

•5 

•7 

•9 

1-0 

1-2 

1-4 

1-6 

1-8 

77-5 

983 

984 

80- 

•2 

•4 

•6 

•8 

•9 

1-0 

1-2 

1-4 

1-6 

80- 

984 

986 

82-5 

•2 

•3 

•5 

•7 

•8 

•9 

10 

1-2 

1-4 

82-5 

986 

988 

85- 

•2 

•2 

•4 

•6 

•7 

•8 

•9 

1-0 

1-2 

85- 

988 

990 

87-5 

•1 

•2 

•3 

•5 

•6 

•7 

•8 

•9 

10 

87-6 

990 

992 

90- 

•1 

•1 

•2 

•4 

•5 

•6 

•7 

•8 

•9 

90- 

992 

994 

92-5 

-   - 

•1 

•2 

•3 

•4 

•5 

•6 

•7 

•8 

92-5 

994 

996 

95- 

-   - 

-   - 

•1 

•2 

•3 

•4 

•5 

•6 

•7 

95- 

996 

998 

97-5 

-   - 

-   - 

-   - 

•1 

•2 

•3 

•4 

•5 

•6 

97-6 

998 

to  fermentation,  but  it  will  indicate  the  value  of  malt  liquors  in  relation  to  their  com- 
ponent  parts.  It  will  likewise  be  a  ready  means  of  testing  the  relative  value  of  worta 
from  sugar  compared  with  grain,  as  well  as  being  a  guide  to  the  condition  of  stock 
beers  and  ales. 

To  ascertain  the  strength  of  malt  liquors  and  their  respective  values^  the  instrument 
has  been  supplied  with  a  glass  saccharometer,  testing-glass,  and  slide-rule.  Commence 
by  charging  the  testing-glass  with  the  liquid,  then  insert  the  saccharometer,  to  ascertain 
Its  present  gravity  or  density  per  barrel,  and  at  whatever  number  it  floats,  that  will 
indicate  the  number  of  pounds  per  barrel  heavier  than  water. 

Example  1.— Suppose  the  saccharometer  to  float  at  the  figure  8,  that  would  indicate 
8  lbs.  per  barrel ;  then  submit  the  liquid  to  the  holing  test,  with  the  salt  as  before 
directed,  and  suppose  it  should  show  (the  barometrical  differences  being  accounted  for) 
90  "P,  that  would  be  equivalent  to  10  per  cent  of  proof  alcohol.     Refer  to  the  slide-rule. 


ond  place  a  on  the  slide  against  10  on  the  upper  line  of  figures,  and  facing  b  on  the 
lower  line  will  be  18,  thus  showing  that  18  lbs.  per  barrel  have  been  decomposed  to 
constitute  that  per  centage  of  spirit;  then,  by  adding  the  18  lbs.  to  the  present  8  lbs. 
per  barrel,  the  result  will  be  26  lbs.,  the  original  weight  of  the  wort  after  leaving  the 

Example  2.— The  saccharometer  marks  10  lbs.  per  barrel,  and  at  the  boiling  point  it 
indicates  88  "p,  equivalent  to  12  gallons  of  proof  spirit  per  cent;  place  a  against  12, 
and  opposite  b  wfll  be  21 1  lbs.  per  barrel,  when,  by  adding  that  to  the  10  lbs.  present, 
81i  lbs.  will  be  the  result  „      ,         x    i.    ©u 

To  ascertain  the  relative  FaZwe.— Suppose  the  price  of  the  26  lbs.  beer  to  »«  f  6*  per 
barrel,  and  the  31  i  lbs.  beer  to  be  40«.  per  barrel,  to  ascertain  which  beer  will  be  the 
cheapest,  place  26  on  the  opposite  side  of  the  rule  against  36,  and  opposite  31 1  ibs.  will 
be  43«.  7/,  showing  that  the  latter  beer  is  the  cheapest  by  3«.  7d  per  barrel. 

By  taking  an  account  of  the  malt  liquors  by  this  instrument  prior  to  stocking,  it 
may  be  ascertained  at  any  time  whether  any  alteration  has  taken  place  in  their  condi- 
tion, either  by  an  increase  of  spirit  by  after  fermentation  and  consequent  loss  of  sac- 
charum,  or  whether  by  an  apparent  loss  of  both,  acetous  fermentation  has  been  going 
on  towards  the  ultimate  loss  of  the  whole. 

This  instrument  will  likewise  truly  indicate  the  quantity  of  spirit  per  cent  created 
in  distillers'  worts,  whether  in  process  of  fermentation  or  ready  for  the  still,  the  only 
diff^erence  will  be  in  the  allowances  on  the  slide-rule. 

N.B.— The  saccharometers  applicable  to  the  foregoing  rules  for  beers,  ales,  Ac,  have 
been  adjusted  at  the  temperature  eo**  Fahrenheit  and  will  be  found  correct  for  gen- 
eral purposes ;  but  where  extreme  minuteness  is  required,  the  variation  of  temperature 
must  be  taken  into  account,  therefore  for  every  10  degrees  of  temperature  above  60, 
3  ths  of  a  pound  must  be  added  to  the  gross  amount  found  by  the  slide-rule;  on  the 
co^ntrary,  for  every  10  degrees  below  60,  .jS^ths  of  a  pound  must  be  deducted. 

For  cordialized  Spirits.— The  operation  in  this  instance  is  somewhat  diff"erent  firom 
that  of  beers  which  have  the  alcohol  created  in  the  original  worts;  whereas,  in  cor- 
dialized spirits,  gins,  &c.,  the  alcohol  is  the  original,  and  the  saccharine  matter,  or 
sugar,  is  an  addendum.  •       j  * 

If  100  gallons  of  spirit  are  requu-ed  at  a  given  strength,  say  50  per  cent  under  proof, 
60  gallons  of  proof  spirit,  with  the  addition  of  50  gallons  of  water,  would  effect  tha„ 
object,  and  upon  testing  it  by  the  alcoholmeter,  it  would  be  found  as  correct  as  by  the 
hydrometer.  But  in  cordializing  spirit  it  is  different,  for  to  the  50  gallons  of  proof 
spirit,  50  gallons  of  sugar  and  water  would  be  added,  thereby  rendering  the  hydrometer 
useless,  except  for  taking  the  specific  gravity  of  the  bulk,  and,  according  to  the  quantity 
of  sugar  present,  so  a  relative  quantity  of  water  must  have  been  displaced ;  and  as  the 
sugar  has  no  reducing  properties,  the  alcoholmeter  will  only  show  the  strength  of  the 
cordial  in  relation  to  the  water  contained  in  it^  as  the  principle  indicates,  irrespectively 
of  saccharine  or  extractive  matter  present  .  ^     .1. 

Suppose,  in  making  100  gallons  of  cordial  at  50^,  3  lbs.  of  sugar  are  put  to  the 
gallon,  or  300  lbs.  to  the  100  gallons,  that  300  lbs.,  displacing  IS^y^th  gallons  of  water, 
only  31-33  th  gallons  of  water  instead  of  50  have  been  applied;  the  sugar,  without 
reducing  p?operties,  making  up  the  bulk  of  100  gallons,  which  is  meant  to  represent 

ThT alcoholmeter  will  only  show  at  the  full  point  of  ebullition  the  alcoholic  strength 
in  relation  to  the  water  in  the  100  gallons  of  the  mixture,  or  35  per  cent  "p,  leaving  lo 
per  cent  to  be  accounted  for  on  the  bulk. 

As  the  quantity  of  sugar  present  must  be  determined  before  that  per  centage  can  be 
arrived  at;  a  double  object  will  be  effected  by  so  doing,  namely,  eliciting  in  all  instances 
the  quantity  of  sugar  present  as  well  as  the  per  centage  of  spirit  to  be  accounted  for. 

Example  1.— In  taking  the  sp.  gr.  of  a  cordial,  suppose  it  to  be  found  1076,  then 
submit  the  liquid  to  the  boiling  point,  and  having  ascertained  the  per  centage  of  alco- 
hoL  and  it  proves  to  be  35  "p,  the  sp.  gr.  of  alcohol  at  that  strength  will  be  found  to  l>e 
956;  deduct  956  from  the  sp.  gr.  of  the  bulk,  or  1076,  and  120  will  remain;  refer  that 
to  its  amount  on  the  head  line  of  table  No.  2,  namely,  120,  under  which  will  be  found 
S.  representing  3  lbs.  of  sugar  to  the  gallon ;  and  by  running  the  eye  down  its  column 
U>  opposite  the  alcoholic  strength  indicated  (35  »p)  will  be  found  14-9,  which  represents 
the  per  centage  of  water  displaced  by  the  sugar,  and  which  amount  of  149,  ajided  to 
I     the  35  per  cent  ascertained,  makes  the  total  upon  the  bulk  49*9  per  cent  »p,  with  3  lbs. 

of  sugar  to  the  gallon.  .    ,    ,     /•       jak^t.*i,,>« 

For  Gins,  ac.— Example  3.  In  taking  the  sp.  gr.,  suppose  it  to  be  found  957 ,  then 
submit  to  the  boiling  point,  and  it  proves  to  be  14  "p,  whose  sp.  gr.  is  937,  which, 
deducted  from  957,  loaves  sp.  gr.  20;  on  the  head-line  of  table  No.  2,  under  20,  will 
be  found  J  or  i  lb.  of  sugar  to  the  gallon,  and  on  running  the  eye  down  to  opposite 


><.^ 


«.-.-'.rt"iaatta<ll>«l^lJinnr««t'1i'  ir    T    iiii»i. 


aey 


620 


ELAINE. 


ELASTIC  BANDS. 


621 


ii 


I 


li-T,  will  be  found  80,  which,  added  to  the  14,  makes  the  total  on  the  bulk  17  per 
cent"P,  with  50  lbs  of  sugar  to  the  100  gallons. 

To  chemists  for  their  tinctures,  <fec.,  this  instrument  will  be  found  essentially  useful 
N.B. — Care  must  be  taken  that  the  mercury  is  entirely  in  the  bulb  of  the  thermo- 
meter before  it  is  fixed  on  the  stem  for  operation,  and  in  all  cases  (except  for  water) 
the  salt  must  be  used. 

Conclusion. — Wines  are  peculiarly  subject  to  be  mystified  by  adulterations  of  various 
kinds.  It  will  prove  of  great  advantage  to  the  public  when  the  relative  quantity  of 
fruit,  or  sacckarum,  and  alcohol  requisite  to  constitute  the  normal  wine  of  each  species 
is  well  ascertained. 

Some  beers  possess  a  remarkable  narcotic  power,  by  which  they  cause  drowsiness 
and  stupor  without  corresponding  previous  exhilaration.  Such  beverages  may  justly 
be  suspected  of  having  been  sophisticated  with  occulm  indicns,  opium,  or  some  analo- 
gous drug ;  and  this  suspicion  may  become  certainty,  if  they  be  shown  by  the  alco- 
holmeter  to  contain  only  a  few  per  cents,  of  fermented  spirit 

The  instrument  in  its  complete  state  is  made  and  sold  by  Mr.  Joseph  Long,  Little 
Tower  Street  The  tables,  of  which  the  above  is  only  a  portion,  and  the  barometric 
indicator,  have  been  constructed  by  him  and  Mr.  Atlee. 

EDGE  TOOLS.  Mr.  James  Bouydell  welds  iron  and  steel  together  in  such  aTOan- 
ner  that  when  cut  up  to  form  edge  tools,  the  steel  will  constitute  a  thin  layer  to  form 
the  cutting  edge.  He  piles  a  slab  or  plate  of  steel  upon  two  or  more  similar  plates 
of  iron,  heats  in  a  furnace  to  a  good  welding  heat,  and  then  passes  between  grooved 
or  other  suitable  rollers,  to  convert  it  into  bars;  the  steel  being  in  a  thin  layer  either  on 
one  of  the  outer  surfaces  of  the  bar,  or  between  two  surfaces  of  iron  according  to  the 
kind  of  tool  to  be  made  therefrom.  The  bars  thus  produced  are  cut  up  and  manufac- 
tured into  the  shape  of  the  desired  articles  by  foiling.  If  the  cutting  edge  is  to  extend 
but  a  short  distance,  the  steel  is  applied  only  near  one  edge  of  the  pile.  In  this  man- 
ner hatchets,  adzes,  choppers,  knives  of  all  kinds,  scissors,  scythes,  chisels,  gouges,  <fec, 
may  be  economically  manufactured ;  the  steel  being  used  merely  for  forming  the  edge, 
while  the  requisite  stiffness  of  the  tools  is  obtained  by  the  iron.  The  compound  bars 
which  have  the  steel  on  one  side  are  suitable  for  chisels  and  other  tools,  which  have  a 
cutting  edge  on  one  side,  the  iron  being  ground  away  when  making  or  sharpening  the 
tool.  Mr.  B.  manufactures  spades  on  a  somewhat  similar  plan. — Newtotta  Journal^ 
vol.  xxvi.  p.  183.     See  Cutlery  and  Steel. 

EDULCORATE,  {Edulcorer,  Fr. ;  AusHUKnen,  Germ.)  is  a  word  introduced  by  th# 
alchemists  to  signify  the  sweetening,  or  rather  rendering  insipid,  of  acrimonious  pul- 
verulent substances,  by  copious  ablutions  with  water.  It  means,  in  modern  language, 
the  washing  away  of  all  particles  soluble  in  water,  by  agitation,  or  trituration  with  this 
fluid,  and  subsequent  decantation  or  filtration. 

EFFERVESCENCE  (Eng.  and  Fr. ;  Aufbramen,  Germ.)  When  gaseous  matter  is 
suddenly  extricated  with  a  hissing  sound  during  a  chemical  mixture,  or  by  the  appli- 
cation of  a  chemical  solvent  to  a  solid,  the  phenomenon,  from  it«  resemblance  to  that 
of  simmering  or  boiling  water,  is  called  effervescence.  The  most  familiar  example  is 
afforded  in  the  solution  of  sodiac  powders;  in  which  the  carbonic  acid  gas  of  sesqui 
carbonate  of  soda  is  extricated  by  the  action  of  citric  or  tartaric  acid. 

EFFLORESCENCE,  (Eng.  and  Fr. ;  Verwittern,  Germ.)  is  the  spontaneous  conversion 
of  a  solid,  usually  crystalline,  into  a  powder,  in  consequence  either  of  the  abstraction 
of  the  combined  water  by  the  air,  as  happens  to  the  crystals  of  sulphate  and  carbonate 
of  soda;  or  by  the  absorption  of  oxygen  and  the  formation  of  a  saline  compound,  as  in 
the  case  of  alum  schist  and  iron  pyrites.  Saltpetre  appears  as  an  eflBorescence  upon 
the  ground  and  walls  in  many  situations. 

EGGS,  HATCHING.     See  Incubation,  Artificial. 

EIDER  DOWN,  is  a  kind  of  precious  down,  so  called  because  it  is  obtained  from 
the  Mder-duck.  These  birds  build  their  nests  among  precipitous  rocks,  and  the  female 
lines  them  with  fine  feathers  plucked  from  her  breast  among  which  she  lays  her  five 
e^s.  The  natives  of  the  districts  frequented  by  the  eider-ducks  let  themselves  down 
by  cords  among  the  dangerous  cliffs,  to  collect  the  downs  from  the  nests.  It  is  used 
to  fill  coverlets,  pillows,  cushions,  Ac. 

ELAINE  is  the  name  given  by  Chevreul  to  the  thin  oil,  which  may  be  expelled 
from  tallow,  and  other  fats,  solid  or  fluid,  by  pressure  either  in  their  natural  state  or 
after  being  saponified,  so  as  to  hnrden  the  ntearine.  It  may  be  extracted  also  by  digest- 
ing the  fat  in  7  or  8  times  its  weiirht  of  boiling  alcohol,  spec.  grav.  0-798,  till  it  dissolves 
the  whole.  Upon  cooling  the  solution,  the  stearine  falls  to  the  bottom,  while  the  elaine 
collects  in  a  layer  like  olive  oil,  upon  the  surface  of  the  supernatant  solution  reduced 
by  evaporation  to  one  eighth  of  \U  bulk.  If  this  elaine  be  now  exposed  to  a  cold  tem- 
perature, it  will  deposit  its  remaining  stearine,  and  become  pure.  See  Fat,  Oils,  and 
Stearins. 


ELASTIC  BANDS.  (Tisms  Elastiques,  Fr. ;  Federharz-zeige,  Germ.)  The  manu 
facture  of  braces  and  garters,  with  threads  of  caoutchouc,  either  naked  or  covered, 
seems  to  have  originated,  some  time  a-o,  in  Vienna,  whence  it  was  a  few  years  since 
imported  into  Paris,  and  Ihence  into  this  country.  At  first  the  pear-shaped  bottle  of 
Indian  rubber  was  cut  into  long  narrow  strips  by  the  scissors;  a  single  operative 
turning  off  only  about  100  yards  in  a  day,  by  cutting  the  pear  in  a  spiral  direction.  He 
succeeded  next  in  separating  with  a  pair  of  pincers  the  several  layers  of  which  the  bottle 
was  composei.  Another  mode  of  obtaining  fine  threads  was  to  cut  them  out  of  a  botUc 
which  had  beea  rendered  thin  by  inflation  with  a  forcing  pump.  All  these  operations 
are  facilitated  by  previously  steeping  the  caoutchouc  in  boiling  water,  m  its  moderately 
mflated  state.  More  recently,  machines  have  been  successfully  employed  for  cutting 
out  these  filaments,  but  for  this  purpose  the  bottle  of  caoutchouc  is  transformed  into 
a  disc  of  equal  thickness  in  all  its  parts,  and  perfectly  circular.  This  preliminary  opera- 
tion is  executed  as  foUows:  1.  the  bottle,  softened  in  hot  water,  is  squeezed  between 
the  two  plates  of  a  press,  the  neck  having  been  removed  beforehand,  as  useless  in  this 
point  of  view;  2.  the  bottle  is  then  cut  into  two  equal  parts,  and  is  allowed  to  con- 
solidate by  cooling  before  subjecting  it  to  the  cutting  instrument.  When  the  bottle  is 
strong  enough,  and  of  variable  thickness  in  its  different  points,  each  half  is  submitted  to 
powerful  pressure  in  a  very  strong  cylindrical  mould  of  meUl,  into  which  a  metallic 
plunger  descends,  which  forces  the  caoutchouc  to  take  the  form  of  a  flat  cylinder  with  a 
circular  base.  The  mould  is  plunged  into  hot  water  during  the  compression.  A  stem  or 
rod  of  iron,  which  goes  across  the  hollow  mould  and  piston,  retains  the  latter  in  its  place, 
notwithstanding  the  resilience  of  the  caoutchouc,  when  the  mould  is  taken  from  the  press. 
The  mould  being  then  cooled  in  water,  the  caoutchouc  is  withdrawn. 

The  transformation  of  the  disc  of  caoutchouc  into  fine  threads  is  performed  by  two 
machines ;  the  first  of  which  cuts  it  into  a  riband  of  equal  thickness  in  its  whole  extent, 
running  in  a  spiral  direction  from  the  circumference  to  the  centre ;  the  second  subdi- 
vides this  riband  lengthwise  into  several  parallel  filaments  much  narrower  but  equally 

thick. 

The  following  figs.  473,  474,  475,  represent  the  machine  for  cutting  the  spiral  riband. 
The  disc  d,  placed  horizontally,  turns  round  its  vertical  axis,  so  as  to  present  its 


473 


474 


periphery  to  the  edge  of  a  knife  c,  formed  like  a  circular  blade,  whose  plane  is  perpen- 
dicular to  that  of  the  bases  of  the  disc.  This  knife  turns  round  its  centre,  which  is 
fixed.  The  rotatory  motion  of  the  disc  forces  the  knife  to  penetrate  further  and  further 
into  its  mass  and  the  motion  of  the  knife  itself  makes  it  cut  the  riband  more  easily.  It 
is  obvious  that  if  the  disc  alone  revolve,  the  motionless  knife  could  act  only  by  pressure, 
and  would  meet  with  an  enormous  resistance.  A  third  movement  becomes  necessary. 
In  proportion  as  the  disc  is  diminished  by  the  removal  of  the  spiral  band,  the  centre  of 
this  disc  must  advance  upon  the  knife,  in  order  that  the  riband  may  have  always  the 
same  breadth.    The  inspection  of  fis-  475  will  make  the  accordance  of  the  three  motions 

intelligible.  i.-  . 

The  knife  c  is  placed  upon  a  shaft  or  axis  a,  which  carries  a  pulley,  round  which  a 
belt  or  cord  runs  which  drives  the  whole  machine.  This  knife  is  six  inches  in  diameter. 
In  order  that  by  being  kept  cool  it  may  cut  the  caoutchouc  better,  it  is  plunged  at  its 
lower  part  into  a  trough  b,  full  of  water ;  a  stopcock  r,  serves  to  empty  this  trough. 

The  shaf\  a  bears  a  pinion  p,  which  takes  into  a  wheel  r,  placed  upon  the  shaft  a'  ; 
upon  which  there  is  cut  a  worm  or  endless  screw,  v,  v.      This  worm  bears  a  nut  s, 


.  f»T''IHllll 


t^t^t^tumm'  Wi  [■[■^—iW t^>J_3:j 


622 


ELECTIVE  AFFINITY. 


which  advances  as  the  screw  turns,  and  carries  w.•f^  If  .  ♦•  ,..  i.  .    . 

the  disc  D,  carried  upon  a  shoulder  con«f«nfi  1  *  ^  *'f  "*  '^^'''^  ^"  '^s  turn  pushes 
guided  by  two  ears  wlTich  slide  in  two '^^v\"s/„t^^^^^^^^  /h^\^"'^"r  P'«  ^^ouFder  is 
diameter  of  the  pinion  p  is  about  one  fifth  of  TJJX  ^^'''^''^'^  «^  ^^  table.  The 
A  tnrns  five  times  less  quickly  than  the  arbor  A'     «n^^^^  ^  *^*'  ^^^  arbor 

butes  further  to  slacken  the  movement  of  traLtaJion  of  rh'  ^."'"'''  ^^  ^^^  ^^''^^  ^  «>«tfi- 

When  the  disc  is  all  cut  down,  the  sho^wir  Z  f  ^^  ^'^\ 
to  their  original  position  by  lifting  the  nut  wh^h   l''v"^  1^'  ""'^  i?  ^"*"^»^*  »«** 
upon  the  shoulder  by  means  of  sharp  noints  «nH  "  ^'"^^^  **"•      ^^^^  disc  is  fixed 

the  washer  have  a  /ery  small  dSerin  orSer  tTatirknT'"-  •  '''^  •^'^'U^"  '^'^^^ 
disc,  advance  as  near  as  possible  to  the  centre  ^^'  ""  ^^'^^'''S  ^^'^  *^« 

The  rotatory  movement  of  the  disc  and  itJ  c»,«.,m  •  • 
w,^  which  governs  a  pinion  p' provid^  with  in  t  '/k''  ^7'"  ^^/"  ^"^^^^^  ^'^'-^'^ 
ppoi  which  the  shoulder  is  m';,Cd  Thf arL  x'  nV^ v  '^'"if  ^^  '^^  '^^^  ^ 
Its  motion  from  the  first  shaft  a,  by  mears  of  thP^K  i  "i  ^?^^^''  "^''^^  ^^<^«^^ 
shafts,  and  of  an  intermediate  wheel  s^  Th.i  y'^^,^'^  s  and  s'  mounted  upon  these 
the  shaft  A",  is  intended  merely  to  allow  this  '  hT^'f '  ""^  ^  ^T'^^'  ^"^^  ^«  ^»»»«  «<" 
di^eterof  the  wheel  Of  this  iLt  ^^i^^o^^^^^'^^::^^^^^^^ 

^^P'i^^etZ^^^^^^^^  /i^-  476.-The  riband  is  engaged 

washers  keep  these  knives  apart  ^t  a  dttanc.wh'K^  "P°"  '^'  '^^^'''  «'  ^  5  thin^rass 
washers  mounted  with  screXon  each  rdCm  Jn/'''  T^  ^^  ^^"^^'  «"d  two  extreme 
these  rollers  traverse  two  uprr^hts  l  i  r„?^- "u^i''  ^^^  ^^«^«  ^y^tem.  The  axes  of 
screws  to  approximate  them  ar;retur::\^^^^  brasses,  aad  with  adjusting 

P  cosure.     xne  axis  of  the  lower  roller  carries  a  wheel 
476 


»,  which  takes  into  another  smaller  wHp*.!  ♦^  »i..^  IT  : —     

which  is  driven  by  a  cord.  The  dirmefer^'/?K  k"^?  ^^^  J^™^  '^^"  ««  ^he  pulley  p. 
wheel  r'.  The  pulley  p  s  twice  thrill  o/ it" Ju'f  l''  '^'a''  ''""^  ^''ealer  thaMhe 
drum  B,  which  drives  the  rest  o?  the  machine  '  ^"'^  '^'  '°'^  P^^^^«  «>'»»d  a 

The  threads,  when  brought  to  this  Bfat«  «r  i  j 
filled  with  cold' water;  they  are  n ex  softened  nwT'/  ^''  ^i^'  ««ccessively  into  tubs 
possible  in  the  following  manner  -Thevar.  w  J  h  ^^"'  ^"^,  ^^°"=*^^^  ^^  much  as 
the  operative  stretches^the  caoutchouc  thread  wUrhisXSd'  Tn  iv'"''  ^."^^''^^'  ^^"^ 
8  or  10  times  longer.  The  reels  when  thus  filled  «r.nw!^'  ^  ■  *^"  "^^  '^  ^^  rendered 
apartment,  where  the  threads  become  firm  « mil       t^K^  ^"u"-^  '^'"^  ^^^^  ^n  a  cold 

This  state  of  stiffness  is  esseS fhr  /J'  ^^^™  ]P  '^^^""^  ^^^'^  "^ture. 
threads  are  commonly  covered  wUh  a  sheath  nri."^  '^  subsequent  operations.  The 
chine,  and  are  then  placed  as  wTrn  in  a  ?^^  '^  ^'^\'  "''"'?'  °'  ^^"^°'  ^^  «  braiding  ma- 
garters,  &c.  If  the  gum  werlto  el?.^":  ""  T^^"  ^^  ?'°^  *  "^'"'•^^  ^^^b  for  braces, 
ferent  threads  would  beTenXVed  anS  .hn  '^' J^^^^'^^'r.  during  this  operation,  the  dlf! 
a  puckered  tissue.  It  is  Jequisife  therefor,  to^'w  '"  ^VT^^l  ?^""^^>  ««  ^^  ^o  form 
extensible,  or  at  least  incon?rac  le^nnH;/^  ^^^""r  ^^^  ^^'^^^^  ^"  ^heir  rigid  and  in^ 
to  the  threads  of  caoutchouc    herapp^^^^^^^^^  '^'  %l'}' ^'  ^«-en^o  restore 

effected  by  passing  a  hot  smoothinTirorover  h.  t'^*   'f  ^^^?  restoration  is  easily 

with  blanket  stuff.    See  Braiding  MAcmNE  '"""^^"^  "P^"  *  ^^^^«  *^«^ered 

ferSlTo^p™^^^  Germ.)  denotes  the  order  of  pre- 

really,  the  gradation  of  attractive  for  eYnftej  rifmiltfw'^  '^''  *"  *=""^^"^ '  «' 
Objects  Of  nature,  Which  determines  ^^rfJ^l^^ZZ':^^^:^^^^^^^^ 


ELECTRIC  TELEGRAPHS. 


623 


amidst  indefinite  variety  of  combination.  The  discussion  of  this  interesting  subject 
belongs  to  pure  chemistry.     See  DEOOMPOsmoN. 

ELECTRO-TELEGRAPHY.  Magnetic  Needle  Telegraphs.— ASiev  CErsted  had  dis- 
covered the  mutual  action  of  electric  currents  and  magnetic  needles,  Ampere  "  pro- 
posed, in  consequence  of  an  idea  suggested  to  him  by  the  illustrious  Laplace,  to  employ 
as  many  circuits  as  there  were  letters  of  the  alphabet,  and  to  make  each  of  them  act  on 
a  separate  needle." 

Schweiger's  invention  of  the  galvanometer,  followed  more  recently  by  "Wheatstone's 
discovery  of  the  velocity  of  electricity,  gave  renewed  impulse  to  these  inquiries. 
Professor  Ritchie  illustrated  Ampere's  idea  on  a  small  scale,  but  rather  with  a  view 
of  pointing  out  the  difficulties  which  enveloped  it  than  to  propose  it  for  practical  pur- 
poses. Alexander's  telegraph  had  thirty  galvanometric  needles  and  thirty-one  wires ; 
each  needle  supported  a  screen,  which  it  carried  with  it  when  deflected,  and  thus  ex- 
posed a  letter.  Davy's  first  telegraph  was  of  the  same  character,  only  the  letters  were 
illuminated.  Baron  Schelling  and  Fechner  proposed  to  limit  this  number  by  employ- 
ing fewer  needles  and  observing  their  combined  motions,  a  different  character  being 
indicated  according  to  the  number  of  needles  in  motion. 

Mr.  Bain  has  proposed  to  fix  the  magnet  and  deflect  the  coil.  The  arrangements 
peculiar  to  Mr.  Wheatstone's  needle  telegraph  are,  that  he  has  one  wire  only  for  each 
needle;  that  two  needles  are  thus  always  included  in  the  circuit;  that  the  combination 
of  the  two  needles  out  of  five,  which  he  generally  used,  will  produce  20  signals,  and 
that  by  a  key-board,  peculiarly  his  contrivance,  these  several  circuits  can  be  readily 
formed.  By  combining  three  or  four  needles,  200  signals  can  be  given.  As  the  motion 
of  these  deflected  needles  was  not  of  itself  sufficiently  violent  to  ring  a  bell  in  order  to 
call  attention,  arrangement  was  made  that  one  of  the  needles  by  its  deflection  should 
complete  the  circuit  of  a  distant  battery,  and  this  would  then  make  an  electromagnet, 
and  liberate  the  detent  of  an  alarm.  Other  modes  of  sounding  an  alarm  were  adopted 
on  account  of  the  difficulties  which  attended  the  early  experiments  on  that  form  of 
telegraph  which  we  shall  presently  describe.  As  it  is  not  the  intention  to  give  here 
a  history  of  telegraphs,  the  above  illustrations  of  the  chief  applications  of  the  galvan- 
ometer to  this  purpose  will  suffice. 

"The  instruments  to  be  first  described  are  the  inventions  of  Messrs.  "W.  Fothergill 
Gooke  and  Charles  Wheatstone,  F.RS.     They  arc  of  two  kinds:  the  one,  in  which  a 


n 


62'! 


ELECTRIC  TELEGRAPHS. 


ELECTRIC  TELEGRAPHS. 


625 


1ft 


R't 


f 


single  galvanometer  is  employed  ;  the  other,  in  which  there  is  a  pair  of  galvanometera. 
The  former  will  serve  our  present  purpose,  as  the  mechanical  adjustments  of  the  latter 
are  merely  the  double  of  this.  I  have  removed  the  case  from  the  instrument  in  order 
to  give  a  clear  view  of  all  the  essential  parts;  and  have  engraved  a  back  view  of  it  {fig. 
477)  with  the  battery  k  attached  as  if  for  use;  and  the  circuit  of  the  galvanometer  a 
completed  by  the  wire  w  w. 

"The  instrument  is  possessed  of  a  two-fold  character;  it  is  passive,  or  ready  for 
receiving  signals  from  another  instrument;  it  is  active,  or  ready  for  transmitting  signals 
to  another  instrument.  By  describing  first  how  it  is  fitted  for  receiving  signals,  and 
then  how  it  is  arranged  for  transmitting  them,  we  shall  be  better  able  conveniently  to 
analyze  it,  and  to  comprehend  its  general  structure.  The  frame  of  the  coil  b  is  of  brass, 
or  (which  is  in  many  respects  better)  of  polished  wood  or  of  ivory ;  it  is  screwed  upon 
the  face  of  the  instrument,  which  face  is  a  brass  plate  varnished  on  the  inner  side. 
Looking  at  the  coil,  a  short  wire  from  its  right-hand  end  comes  to  a  screw  terminal, 
which  latter,  by  a  slip  of  brass  neatly  laid  on  the  instrument  case,  is  connected  with 
another  terminal  u.  The  left-hand  end  of  the  coil  comes  also  to  a  terminal,  from  which 
a  slip  of  brass  descends  to  a  brass  plate  here,  partly  hidden ;  but  its  form  may  be  gathered 
from  a  similar  plate,  visible  on  the  left  side.  These  twin  plates  are  in  metallic  connec- 
tion by  means  of  the  two  upright  springs,  plainly  shown  in  the  drawing.  The  springs 
are  of  stout  steel,  and  press  strongly  on  two  points  in  a  short  insulated  brass  rod  n,  which 
is  screwed  in  the  wooden  framework  of  the  instrument  The  left-hand  plate  is  con- 
nected with  the  terminal  d,  also  by  a  slip  of  brass.  If  now,  the  two  terminals  u  and  d 
are  connected  by  a  wire  w  w,  the  circuit  will  be  complete,  as  follows:  from  the  terminal 
u  into  the  coil  at  the  right-hand  side;  out  of  the  coil,  at  the  left-side  downwards  to  the 
right-hand  plate;  up  the  right-hand  steel  spring,  across  the  brass  rod  n  to  the  left-hand 
steel  spring;  downward  by  this  spring  to  the  left-hand  plate,  thence  by  the  slip  of 
brass  to  the  terminal  d,  and  thence  by  the  wire  w  w  the  terminal  u,  whence  we  started. 
If  now  the  wire  from  u  went  up  the  line  of  railway,  and  the  wire  from  d  down  the 
line,  and  the  circuit  were  in  some  way  kept  complete  on  the  large  scale,  as  it  has  been 
here  described  on  the  small  scale,  any  electric  current  passing  along  the  wire  from  a 
distant  station,  would  traverse  this  coil  in  its  course,  would  deflect  the  needle,  and  so 
make  a  signal.  I  should  here  mention  that  for  the  sake  of  regularity,  we  adopt  one 
unvaried  order  in  attaching  wires  to  the  instrument;  it  is  to  put  the  up  wire  on  the 
terminal,  shown  by  u  on  the  figure,  the  coils  being  all  uniformly  wound. 

"So  far  for  receiving  a  signal — now  for  sending  one.  Were  we  to  go  out  on  the 
open  railway,  taking  with  us  a  battery,  and  to  cut  any  one  of  the  wires,  and  place  its 
two  ends,  thus  obtained,  upon  the  two  terminal  ends  of  the  battery,  a  current  would 
pass  along  the  line,  and  the  needles  on  that  wire  would  be  deflected ;  and  if  we  changed 
bands  so  as  to  reverse  the  connections,  the  deflection*  of  the  needle  would  be  reversed. 
The  same  would  happen  were  we  to  cut  a  wire  inside  the  office,  or  inside  the  tele- 
graph, and  to  treat  it  in  a  similar  way.  Now,  in  every  apparatus  contrived  for  trans- 
mitting signals,  we  have  a  place  corresponding  to  such  a  cut  wire ;  and  near  this  place 
are  the  poles  of  the  battery,  mounted  and  moveable,  so  that  they  may  be  readily 
applied  in  the  breach,  one  way  or  other  as  required.  The  place  here  {fig.  477)  is  the 
top  of  the  springs.  They  are  xiot  joined  to  the  brass  rod  n;  but,  as  I  said  before,  press 
hard  upon  it,  and  can  readily  be  raised  with  the  finger,  or  otherwise.  It  is  obvious 
that,  when  either  of  them  is  raised,  the  circuit  is  broken.  Now,  near  this  place  is  a 
mechanical  contrivance,  by  which  the  poles  of  the  battery  may  make  a  breach  in 
the  circuit,  and  be  applied  in  the  breach  in  either  direction.  The  drum  b  is  of  box- 
wood, the  ends  c  and  z  being  capped  with  brass,  and  insulated  from  each  other  by 
the  wood,  6,  left  between  them.  The  drum  is  moveable  by  a  handle,  not  in  sight 
here,  and  is  supported  as  shown  in  the  present  figure.  A  stout  steel  wire  c'  is  screwed 
beneath  into  the  c  end  of  the  drum ;  and  a  similar  z'  is  screwed  above  into  the  z  end. 
These  two  wires  are  the  poles  of  the  battery,  z'  being  connected  with  the  zinc  end, 
and  c'  with  the  copper,  thus: — from  the  copper  end  of  the  battery  a  wire  is  led  to 
the  terminal  c;  thence  a  slip  of  brass  leads  to  a  curved  brass  spring  which  presses 
closely  on  the  drum  at  c ;  from  the  zinc  end  of  the  battery  a  wire  goes  to  the  terminal 
2,  and  thence  a  slip  of  brass  leads  to  a  similar  curved  spring,  pressing  on  the  continuation 
of  the  z  end  of  the  drum,  as  shown  in  the  figure.  It  will  be  seen  that,  whenever  the 
drum  is  moved,  the  steel  wire  z'  will  lift  up  one  or  other  of  the  upright  steel  springs; 
it  is  now  lifting  up  the  right-hand  one,  and  so  breaks  the  circuit;  but,  by  a  little  further 
motion  of  the  drum,  the  wire  c'  will  press  upon  the  boss  below,  as  shown  in  the  figure, 
and  thus  there  will  be  a  battery  pole  on  each  side  of  the  breach,  and  a  signal  will  be 
made  on  this,  and  on  all  instruments  connected  with  it  And,  from  the  peculiar 
arrangement  with  the  drum,  the  motion  can  be  changed  as  rapidly  as  the  hand  can 
move.  I  have  shown  the  battery  connections  exactly  as  they  occur  in  practice;  and 
the  connections  are  such  that,  if  the  right-hand  springs  are  moved  of^  the  needle  moves 
to  tU>  right,  and,  if  the  left,  to  the  left    The  needle  on  the  face  of  the  instrument  always 


hcis  its  north  end  upward,  and  the  needle  within  the  coil  its  north  end  downward,  so 
i-hat  if  we  look  at  the  face  of  an  instruments,  and  see  the  top  end  of  the  needle  move  to 
tiift  right,  we  may  be  sure  that  in  the  half  of  the  coil  nearest  to  us  the  current  is  ascending."* 

Thus  the  wires  are  the  channels  through  which  electric  influences  are  conveyed  to 
great  distances  with  inconceivable  velocity,  and  the  moveable  magnets,  or  galvanometers, 
<:o  which  the  wires  are  attached  at  the  stations,  are  the  parts  of  the  apparatus  by 
which  signals  are  made.  The  mode  of  interpreting  these  signals  is  thus  described  by 
the  author: — 

"  Double-needle  Code. — Having  described  the  apparatus  and  means  employed  for 
producing  at  pleasure  the  transmission  of  signals  to  distant  places,  it  now  remains  to 
us  to  explain  the  manner  of  interpreting  these  signals,  so  that  each  person  shall  under- 
stand the  ideas  the  other  would  convey. 

"We  have  to  describe  how,  out  of  only  two  needles,  each  of  which  has  but  two 
movements,  the  telegraph  alphabet  is  formed.  On  the  face  of  the  instrument  are  the 
letters  of  the  alphabet  arranged,  as  it  will  be  seen,  seriatim  in  two  lines,  beginning  at 
the  left^  and  ending  at  the  rights  as  ii.  writing.  The  commencing  series  from  A  to  P 
is  above  the  top  end  of  the  needles ;  and  the  concluding  series  from  R  to  Y  below  the 
bottom  end.  It  will  also  be  seen  that  some  letters  are  engraved  once,  some  ttoice,  and 
others  three  times.  To  make  a  letter  engraved  once,  requires  one  motion  of  the  needle ; 
to  make  one  engraved  twice,  tvoo  motions  of  the  needle ;  and  to  make  one  engraved  three 
times,  three  motions.  In  respect  to  the  upper  row,  the  needle  nearest  to  the  letter  iu 
moved,  and  it  is  moved  so  as  to  point  toward  the  letter.  In  respect  to  the  lower  row, 
both  needles  are  moved,  and  their  lower  end  is  made  to  point  in  the  direction  of  the 
letter  required.  Six  of  the  letters  C,  D,  L,  M,  and  U,  V,  require  a  twofold  motion 
of  the  needle  or  needles,  first  to  the  right  then  to  the  left  for  C,  L,  and  U,  and  first  to 
the  left  then  to  the  right  for  D,  M,  and  V.  These  six  letters  are  engraved  intermediate^ 
and  with  a  double  row  between.  The  alphabet  produced  by  this  arrangement  is  of  a 
simple  character,  and  is  very  readily  acquired.  To  the  stranger  it  appears  confused; 
but  when  he  has  the  key  to  it  the  difficulty  disappears;  it  might  at  first  sight  appear 
<^bat  a  dial  instrument — a  telegraph,  that  is,  provided  with  alphabets  engraved  on  a 
c'Veular  dial,  and  an  index  made  to  revolve,  and  point  to  any  required  letter,  is  more 
simple;  several  such  telegraphs  exist;  and  among  them  are  some  very  happily  arranged ; 
and  there  is  something  so  simple  in  the  fact  of  being  able  to  point  to  any  desired  letter, 
that  it  is  no  wonder  the  public  generally  may,  on  a  hasty  glance,  and  before  studying 
the  practical  merits  of  the  case,  be  ready  to  decide  in  their  favor,  and  prefer  them  to 
any  other  plan,  the  A,  B,  C  of  which  is  less  obvious. 

"But  is  it  such  a  very  serious  matter  to  learn  another  alphabet?  Every  school- 
boy, now-a-days,  knows  some  half-dozen  alphabets;  there  are  ROMAN  letters  lai^e, 
and  Roman  letters  small;  3fAN US CRIF 2' Utters  large,  and  manuscript  letters  small; 
#ltt  JSnfllisf)  large,  and  Old  English  small ;  Greek  large,  and  Greek  small,  and  so  on, 
and  all  different.,  and  not  one  of  them  in  which  the  letters  are  represented  by  so  few 
strokes  of  the  pen  as  are  the  telegraph  letters  by  beats  of  the  needle.  Take  one  of  our 
plainest  alphabets  as  an  example ;  the  ROMAN  CAPITALS,  for  instance,  and  place 
a  few  of  them  in  juxta-position  witli  the  corresponding  telegraph  signals: — 

A  \\  E  /  G  /// 

B  \\\  F  //  H  \ 

"The  simplicity  of  these  symbols  is  obvious.  Two  diagonal  and  one  horizontal 
line  are  required  for  the  Roman  A ;  two  diagonal  lines  for  the  telegraph  A ;  one 
vertical  and  three  horizontal  lines  make  the  Roman  E;  one  diagonal  the  telegraph  E, 
and  so  on;  the  difference  being  that  all  the  world  have  learned  the  Roman  alphabet, 
and  only  a  chosen  few  have  studied  the  telegraphic  symbols.  That  the  latter  really 
are  simple  and  distinctive:  that  they  are  full  of  meaning  and  very  legible;  that  they 
are  applicable  to  ordinary  language,  and  good,  ay,  very  good!  no  one  will  for  a  moment 
doubt,  who  has  seen  the  rapidity  and  accuracy  with  which  a  telegraph  officer  receives 
a  dispatch. 

"To  one  who  sees  a  telegraph  in  operation  for  the  first  time,  the  eficct  borders  on 
the  marvellous ;  setting  out  of  the  question  the  fact  that  the  needles  are  caused  to" 
move  by  an  individual  perhaps  a  hundred  miles  off;  the  motion  of  the  needles  hither 
and  thither;  quicker  than  the  untrained  eye  can  follow ;  the  want  of  all  apparent  order 
and  rule  in  their  movement;  the  ringing  of  the  changes  between  one  and  the  other, 
and  both;  the  quiet  manner  in  which  the  clerk  points  his  needle  to  the  letter  E,  in 
rapid  intervals,  implying  that  he  understands  the  word;  while,  to  the  uninitiated 
looker-on,  all  is  wonder  and  mystery,  and  confusion ;  and  the  rare  occurrence  of  the 
clerk  pointing  to  »J«,  implying  he  did  not  understand;  and,  finally,  the  quiet  manner 
with  which  the  clerk  tells  you,  very  coolly,  as  the  result  of  his  operations,  "That  the 
very  pretty  girl,  with  bright  blue  eyes  and  long  curls,  has  sailed  for  Boulogne  in  th* 
Princess  Clementine,  now  leaving  Folkstone  Harbor;  and  that  she  is  accompanied  by 


,; 


626 


ELECTRIC  TELEGRAPHS. 


F; 


the  tall,  handsome  man,  with  the  dark  moustache  and  military  eloak.'  As  he  tells  jon 
thip,  and  says,  'Message  and  answer,  forty  words  two  mien  at  10ft  6dl,  one  guinea, 
porterage  n  shilling — one  pound  two.'  If  you  happen  to  be  the  papa  of  the  pair  of 
blue  eyos,  you  are  bewildered,  and  wish  you  were  an  electric  current,  and  could  be 
sent  after  them." — From  Electric  Telegraph  Manipulation,  by  C.  V.  Walker. 

An  invention  apparently  very  simple  and  comprehensive  for  electro-telegraphic 
correspondence,  was  made  the  subject  of  a  patent  in  February,  1851,  in  Newton's 
Journal.  It  consists  in  the  use  of  such  parts  or  arrangement?  of  apparatus  as  will 
allow  two  or  more  persons,  by  the  agency  of  electricity,  to  send  or  receive  signals  or 
intelligence  by  one  common  wire  of  communication  or  main  conductor,  whilst  the 
rapidity  or  closeness  in  the  order  of  succession  of  the  signals,  consequent  on  the  in- 
definite short  time  the  main  conductor  is  in  actual  use  in  conveying  the  electric  current 
for  transferring  the  signal  shall  be  such,  that  all  the  persons  so  employed  in  these 
telegraphic  operations  can  be  continually  and  simultaneously  occupied,  in  like  manner 
as  if  each  one  of  them  had  a  distinct  wire  of  communication  all  the  time  waiting  for 
or  appropriated  to  his  particular  use.  By  this  invention  the  same  practical  telegraphic 
results  are  obtained,  through  agency  of  the  one  wire  or  main  conductor,  as^  in  the 
varieties  of  the  electric  telegraph  before  known  or  used,  would  require  several  distinct 
wires  of  communication.  According  to  this  improved  plan  of  working,  the  wire  of 
communication  or  electric  conductor  may  be  considered  as  a  public  word  road,  or  an 
omnitelegraphic  way;  whereas,  in  contradistinction,  the  conductor,  as  heretofore  used, 
may  be  considered  a  private  word  road,  or  a  unitelegraphic  way.  In  addition  to  the 
ability  of  allowing  divers  parties  simultaneously  to  telegraph  at  will  either  all  in  the  same 
or  in  contrary  directions,  over  or  along  one  wire  of  communication,  this  improvement 
enables  each  one  of  the  operators,  so  employed,  to  have  and  to  use  as  many  distinct 
short  wires  or  accessory  conductors,  all  related  to  the  main  conductor,  as  the  operators 
may  desire  to  have  separate  signals;  whereby  the  facility  of  making  and  receiving  or 
recording  signals  or  intelligence  is  greatly  increased.  Thus,  for  example, — suppose  ten 
men  at  each  end  of  the  wire  of  communication  are  all  using  the  same  wire  of  communi- 
cation which  connects  the  distant  places,  tlieir  practical  telegraphic  facilities  would  be 
greater  than  could  be  had  by  the  old  system,  if  these  twenty  men  had  twenty  different 
wires  of  communication  in  place  of  only  one  such  wire;  and  would  be  as  great  as  could 
be  had  by  the  old  system,  if  each  of  those  twenty  men  had  as  many  such  wires  as  they 
might  desire  to  make  or  receive  different  signals.  Thus,  supposing  twenty-five  signals  to 
be  made  and  twenty-five  to  be  received,  for  each  of  these  twenty  men,  1,000  separate  wires 
or  main  conductors  would  be  required,  in  order  to  accomplish  what^  by  the  new  system, 
requires  only  one  such  main  conductor,  aided  by  1,000  short  wires  or  accessory  conduct- 
ors) or  signal-making  and  signal-receiving  wires,  which  need  be  of  but  a  few  inches  in 
length  severally,  or  so  long  as  to  reach  to,  or  be  systematically  put  into,  electric  relation 
with  the  respective  ends  of  the  main  conductor  or  wire  of  communication ;  or,  otherwise 
by  motion  be  successively  brought  into  electric  communicition  with,  and  so  momentarily 
forming  in  succession,  portions  of  the  conductor,  by  which  the  electric  current,  circuit, 
or  line  of  inductive  action  is  established,  maintained,  or  broken,  from  time  to  time.  It 
may  be  stated  that  this  improvement  rests  upon  taking  advantage  of  the  circumstance 
Itliat,  practically  speaking,  no  sensible  portion  of  the  time  employed  in  working  the 
telegraph  is  expended  in  the  actual  transmission  of  the  electric  influence,  which  is  the 
medium  or  agent  of  the  communication,  but  that  is  due  to  the  operation  of  making  or 
recording  the  signals.  One  wire,  reaching  between  the  distant  places,  is  therefore  capable 
of  being  the  instrument  of  transmitting  an  indefinite  number  of  different  signals  in  a  sec- 
ond of  time,  provided  that  suitable  adaptations  are  made  to  enable  so  many  different  sig- 
nals to  be  separately  placed  upon  one  end  of  the  main  conductor,  and  received  or  recorded 
at  the  other  end  of  the  conductor,  in  an  intelligible  manner.  There  are  an  indefinite  num- 
ber of  methods  of  applying  to  practice  this  improvement^  differing  more  or  less  in  kinds 
of  apparatus  used,  and  in  modifications  of  electrical  actions  applied.  But  all  are  sub- 
stantially the  same  improvement;  inasmuch  as  their  action  would  be  to  set  apart  distinct 
and  small  and  successive  fractions  of  a  second  or  other  period,  and  assign  and  apply 
.such  email  fractions  of  time  to  different  uses  or  for  different  persons;  so  that,  although 
many  persons  should  all  simultaneously  be  employed  in  using  one  common  wire  of  com- 
munication, yet  all  the  signals  so  transmitted  by  it  maybe  successive;  the  rapidity  of  the 
electric  conduction  admitting,  by  this  invention,  the  divers  signals  to  be  transmitted 
successively  along  the  wire,  and  yet  so  quickly  the  one  after  the  other,  as  to  give  a  like 
practical  result,  as  if  they  were  simultaneously  transmitted  by  separate  wires  or  main 
conductors.  A  convenient  mode  of  applying  this  improvement  to  practice,  and  for 
illustrating  the  principle  of  the  invention,  may  be  understood  by  referring  to  the  diagram 
{fig.  478),  wherein  two  pendulums,  supposed  to  be  actuated  by  clock  work  or  other 
suitable  means,  are  indicated;  such  pendulums  being  made  to  vibrate  as  nearly  as 
possible  together  in  position  and  in  time  of  vibration.    At  the  chief  station  a,  the 


ELECTRIC  TELEGRAPHS. 


627 


standard  pendulum  is  situate;  and  the  dependent  telegraph  station  is  also  provided 
with  a  pendulum,  as  at  b.  d,  d  are  the  pendulum  rods,  with  these  balls  or  weights; 
E,  the  prolonged  end  of  the  pendulum  rods,  which  should  be  much  longer  in  proportion 
than  represented  in  the  drawing;  f,  slight  springs,  united  to  the  prolonged  end  of  the 


I  p-rY>y-ynrrYVYYY^  YTYYTYYYrrr^^ 


pendulum  rods;  and  p,  b,  p,  andp,  9,  p,  are  two  grooves  or  pathways,  so  made  that  the 
spring  F  shall  fall  into  the  groove  p,  r,  p,  when  the  pendulum  makes  the  vibration  from 
left  to  right,  and  shall  fall  into  the  groove  p,  s,  p,  when  making  the  vibration  from  right 
to  left;  c,  c,  is  the  main  conductor  or  wire  of  communication,  connecting  the  two  tele- 
graphic stations  a  and  b  together ;  x,  x,  are  ground  plates  and  ground  wires.     At  station 
A,  there  are  metallic  points  over  which  the  spring  f  passes,  touching  the  surface  each 
vibration, — which  points  are  connected  with  the  conductors  l,  x.     The  groove  p,  r,  p, 
at  station  b,  is  of  metal,  and  in  electric  communication  with  l  and  x.     The  spring  f,  in 
moving  in  either  of  the  grooves  p,  r,  p,  or  in  the  p,  s,  p,  of  station  a,  is  kept  in  its  path  by 
an  insulated  or  non-conducting  guide ;  z  is  a  Leyden  jar,  prime  conductor  of  an  electrical 
machine,  or  galvanic  pile,  kept  constantly  charged,  or  capable  of  giving  a  great  number 
of  visible  sparks  or  electric  pulsations  per  second,  on  making  or  breaking  the  electi'ic 
circuit  or  line  of  inductive  action.     The  wire  c,  C3,  c,  has  a  metallic  connection  with  the 
upper  end  of  the  pendulum  rods,  which  arc  also  metallic  as  well  as  their  prolonged  ter- 
minations.    In  this  condition  of  things,  whenever  the  spring  f,  at  station  a,  passes  over 
K,  K,  in  its  vibrations,  there  will  be  an  electric  communication  or  circuit  from  z  to  k, 
through  L,  X,  to  the  ground  at  station  a;  also  from  z  to  the  metallic  groove  p,  r,  p,  at 
station  b,  and  to  the  ground  there ;  provided  the  pendulum  at  station  b  is  making  its 
vibration  from  left  to  right,  when  the  pendulum  at  station  a  carries  its  spring  f  over 
the  conducting  point  k.     At  k  on  the  left-hand  side  of  the  standard  pendulum,  there  are 
two  metallic  faces  near  together;  by  this  arrangement  it  can  be  known  at  station  b  when 
the  pendulum  at  station  a  is  in  motion,  and  the  position  of  its  vibrations  exactly  deter- 
mined; so  that  the  pendulum  at  b  can  be  from  time  to  time  set  in  motion,  accelerated 
or  retarded,  in  order  to  maintain  that  degree  of  synchronism  in  the  action  of  the  pendu- 
lums, and  similarity  of  position,  which  are  necessary  for  success  of  the  telegraphic  opera- 
tions.    When  the  pendulum  at  b  is  correctly  timed  in  its  motions,  there  will  be  visible 
two  sparks  on  the  left-hand  side,  and  one  spark  on  the  right-hand  side,  of  the  conduct- 
ing groove  at  k,  k,  at  station  b,  equal  distance  from  the  centre  of  vibration ;  but  when 
this  pendulum  is  not  in  its  proper  position  or  motion,  these  sparks  can  be  seen  at  other 
places  along  the  groove,     h^  and  u2,  at  both  stations  are  signal-making  wires;  and 
g',  g2,  at  both  stations,  are  signal-receiving  wirea     These  signal  wires  are  to  be  sup- 
posed as  numerous  in  each  set  as  the  number  of  different  signals  desired  to  be  used — 
say  not  less  than  the  letters  of  the  alphabet;  a  smaller  number  is,  however,  shown 
in    the   drawing  for  distinctness'  sake.      All   the   signal-receiving  wires   reach    into 
the   groove  or  pathways  p,  s,  p,  in   such    a   manner,  that  the  spring  f  shall  touch 
and  slide  over  the  flattened  faces  or  ends  of  these  wires  in  succession  each  time 
the  pendulum  moves  from  right  to  left     The  signal-making  wires  on  the  contrary, 


628 


ELECTRO-GILDING. 


I 


rii    ' 


II  .' 


stand  a  little  off,  out  of  the  groove  or  pathway,  but  are  intended  to  be  so  mounted  that 
each  may  be  raised  with  the  pressure  of  the  finger,  and  brought  into  the  line  of  the 
groove  or  pathway,  to  be  touched  by  the  spring  f,  when  the  pendulum  swings  from 
left  to  right  All  these  signal  wires  are  united  by  one  end  to  the  conductor  l,  l,  but 
are  free  and  independent  at  the  other  end.  The  free  end  of  the  signal-receiving  wires 
may  have  a  width  of  half  an  inch,  more  or  less,  where  f  passes  over  them.  The  cor- 
responding ends  of  the  signal-making  wires  may  be  put  on  edge  or  line;  so  that  the 
signal-making  wires  can  be  touched  by  f  but  for  a  moment,  whilst  the  signal-receiving 
wires  will  be  touched  for  a  sensible  time  by  f,  in  passing  over  them. 

Under  these  circumstances,  if  any  one  of  the  signal-making  wires  ill,  at  station  a,  be 
touched  and  brought  into  contact  with  the  end  f,  of  the  vibrating  pendulum,  a  con- 
ducting circuit  or  electric  current  will  be  established  for  the  moment,  the  correspond- 
ing pendulum  at  station  b  will  be  in  front  of  the  group  of  signal-receiving  wires  nl  of 
that  station.  Therefore,  from  the  electric  circuit  existing  for  that  moment  of  contact, 
there  would  be  a  spark  visible  upon  the  flattened  end  of  that  one  of  the  signal-receiving 
wires  which  corresponds  to  that  one  of  the  signal-making  wires  at  the  other  station,  which 
may  have  been  pressed  upon  and  brought  into  the  pathway  of  f;  all  these  signal  wires 
in  each  set  being  marked  by  and  signifying  the  different  letters  of  the  alphabet,  Ac 
It  is  obvious,  that  if  the  left-hand  wire  of  each  set  be  marked  a,  the  next  b,  next  f,  Ac, 
then,  should  a,  6,  or  c,  of  a  signal-making  group  h^,  station  a,  be  pressed  upon  and 
touched  by  f,  this  act  will  be  known  at  station  b,  by  the  appearance  of  a  spark  on  the 
end  of  that  one  of  the  signal-receiving  wires  a,  6,  or  c,  of  group  u^  station  b,  correspond- 
ing to  that  wire  which  may  have  been  so  touched  at  station  a.  Thus,  at  will,  can  any- 
signal  or  letter  be  sent  from  station  a  to  station  b,  and  during  the  operation  of  signal- 
making,  by  one  person  at  station  a,  to  another  at  station  b.  It  will  now  be  seen  that 
another  person,  or  the  same  person  at  station  b,  by  the  use  of  the  wires  n^,  can  telegraph 
in  reply  to  station  a,  by  making  use  of  the  set  of  wires  ill  of  each  station,  in  a  manner 
similar  to  those  in  which  the  wires  h1,  before  described,  wefe  used.  Suppose  that  the 
time  of  a  double  vibration  of  these  pendulums  is  equal  to  the  time  necessary  for  con- 
veniently making  and  observing  a  signal,  then,  by  the  use  of  the  four  seta  of  signal 
wires  above  named,  a  person  may  send  to  or  receive  signals  from  or  between  stations 
a  and  B  reciprocally;  or  four  persons  may  be  continually  and  simultaneously  employed 
in  making  and  receiving  signals  at  each  station.  The  use  of  these  signal- wires  referred 
to,  as  able  to  employ  four  persons  in  continual  telegraphic  intercourses,  will  in  no 
way  interfere  with  the  simultaneous  employment  of  two  or  four  other  operators  using 
the  other  signal  wires  on  the  right-hand  half  of  the  vibrations  marked  u2  and  g2;  so 
also  by  lengthening  out  the  ends  of  the  pendulum  rods,  or  increasing  the  angular  mo- 
tion of  the  pendulums,  more  ppace  or  places  may  be  had  for  carrying  out  a  larger  num- 
ber of  telegraphic  operations  indefinitely. 

It  has  been  said  that  the  pendulum  at  station  b  may  be  kept  adjusted  to  the  motions 
of  the  jegulating  pendulum,  by  the  appearance  of  sparks  at  k,  k;  but  this  synchronism 
may  be  more  perfectly  maintained  by  using  any  of  the  known  forms  of  electro-magnets. 
In  the  above  illustration  the  electric  spark  from  an  electrical  machine  has  for  simplicity 
been  chosen  as  the  visible  signal ;  but  should  it  be  desired  to  make  signals  by  the 
hydro-electric  current  and  the  deflection  of  a  needle,  then  each  one  of  the  signal-receiv- 
ing wires,  before  uniting  with  the  common  conductor  l,  may  be  lengthened  out  suf- 
ficiently to  form  the  coil  of  a  galvanometer ;  and  the  current  passing  through  any  one 
of  these  wires  can  make  itself  known,  or  a  signal  be  so  given,  by  the  deflection  of  the 
needle  of  the  galvanometer  belonging  to  that  particular  signal-receiving  wire  so  signal- 
ized ;  or,  in  like  manner,  those  prolonged  signal-receiving  wires  may  each  one  enclose 
a  bar  of  iron,  in  place  of  a  magnetic  needle,  so  as  to  have  an  electro-magnet  and  keeper 
belonging  to  each  one  of  these  wires ;  then  the  passage  of  the  current  through  any  of 
the  wires  may  give  magnetism  to  the  bar,  or  actuate  the  magnet  or  its  keeper ;  and 
from  this  motion  the  signals  may  be  perceived,  or  recorded  and  printed  in  any  con- 
venient form.  From  the  above  explanations,  it  will  be  obvious  that  divers  stations  and 
complex  systems  of  telegraphic  lines  of  communications  can  be  established  on  the  prin- 
ciple of  this  invention ;  and  it  will  be  also  understood,  that  the  invention  is  susceptible 
of  an  indefinite  number  of  modifications  or  forms,  as  respects  the  apparatus  employed 
in  carrying  it  into  use.  The  patentee  claims,  rendering  available  conducting  power  of 
electric  telegraph  wires,  so  that  they  may  transmit  one  or  more  electric  currents  (in  the 
same  or  opposite  directions)  during  the  time  that  must  necessarily  elapse  between  the 
transmission  of  succeeding  signals  which  have  reference  to  one  and  the  same  communi- 
cation.— Newton's  Journal,  xl.  36. 

ELECTRO-GILDING  AND  SILVERING.  According  to  Le  Docteur  Philipp, 
the  vessel  required  for  this  purpose  should  be  made  of  the  same  material  as  that 
commonly  employed  for  flower-pots:  before  being  used  it  must  be  tested  in  the  follow- 
ing manner :  On  being  filled  with  water,  if  it  becomes  simply  damp,  without  allowing 
the  water  to  filter  through  it^  it  is  fit  for  use,  but  not  otherwise.     This  vessel  is  sur* 


ELECTRO-METALLURGY. 


629 


rounded  by  a  cylinder  of  zinc,  and  then  introduced  into  another  vessel  (a  wooden  tub 
for  instance)  containing  dilute  sulphuric  acid.  The  earthen  vessel  is  intended  to  con- 
tain the  solution  of  gold  or  silver,  and  is  furnished  with  a  web  of  copper  wire,  which 
is  made  to  communicate  with  the  zinc  by  means  of  one  or  more  conducting  wires.  The 
objects  to  be  gilt  or  silvered  are  placed  upon  the  net-work.  The  earthen  vessel  contain- 
ing a  zinc  cylinder,  and  some  hydrochloric  acid,  is  introduced  into  another  vessel,  con- 
taining the  solution  of  gold  or  silver,  placed  in  the  centre  of  a  wire  web  partition, 
which  communicates  with  the  zinc  cylinder  by  means  of  a  conducting  wire.  In  the 
first  case,  the  articles  which  are  to  receive  the  thickest  coating  are  placed  nearest  the 
outer  sides  of  the  apparatus;  in  the  second,  nearest  to  the  earthen  vessel;  in  both  cases 
it  is  advisable  to  shift  their  position  occasionally.  By  combining  these  different 
arrangements,  the  deposit  obtained  is  more  abundant,  and  more  equally  distributed 
upon  the  surface  to  be  gilded  or  to  be  silvered.  For  this  purpose  an  opening  is  made 
in  the  centre  of  the  web  in  which  the  zinc  cylinder  is  inserted,  with  connecting  wires 
to  the  web.  When  the  articles  to  be  operated  upon  can  be  easily  suspended  from  a 
given  point,  the  web  of  the  apparatus  may  be  made  with  wider  meshes,  and  the  articles 
suspended  vertically  between  them.  Dr.  Philipp  prefers  a  single  galvanic  arrangement 
to  a  battery,  as  it  affords  more  solid  deposition. 

ELECTRO-METALLURGY.     By  this  elegant  art  perfectly  exact  copies  of  any 
object  can  be  made  in  copper,  silver,  gold,  and  some  other  metals,  through  the  agency 
of  voltaic  electricity.    The  earliest  application  of  this  kind  seems  to  have  been  prac- 
tised about  16  years  ago,  by  Mr.  Bessemer,  of  Camden  Town,  London,  who  deposited 
a  coating  of  copper  on  lead  castings,  so  as  to  produce  antique  heads  in  relief,  about  8 
or  4  inches  in  size.     He  contented  himself  with  forming  a  few  such  ornaments  for  his 
mantelpiece;  and  though  he  made  no  secret  of  his  purpose,  he  published  nothing  upon 
the  subject     A  letter  of  the  22d  of  May,  1839,  written  by  Mr.  J.  C.  Jordan,  which  ap- 
peared m  the  Mechanics'  Mag.  for  June  8,  following,  contains  the  first  printed  notice  of  the 
manipulation  requisite  for  obtaining  electro-metallic  casts;  and  to  this  gentleman,  there- 
fore, the  world  is  indebted  for  the  first  discovery  of  this  new  and  important  application 
of  science  to  the  uses  of  life.     It  appears  that  Mr.  Jordan  had  made  his  experiments  in 
the  preceding  summer,  and  having  become  otherwise  busily  occupied,  did  not  think  of 
publishing  till  he  observed  a  vague  statement  in  the  Journals,  that  Professor  Jacobi,  of 
»t  Petersburg,  had  done  something  of  the  same  kind.     Mr.  Jordan's  apparatus  consisted 
of  a  glass  tube  closed  at  one  extremity  with  a  plug  of  plaster  of  Paris,  and  nearly  filled 
with  a  solution  of  sulphate  of  copper.    This  tube,  and  its  contents,  were  immersed  in 
a  solution  of  common  salt.     A  plate  of  copper  was  plunged  in  the  cupreous  solution, 
and  was  connected  by  means  of  a  wire  and  solder,  with  a  zinc  plate  dipped  in  the 
brine.     A  slow  electric  action  was  thus  established  through  the  moist  plaster,  and 
copper  was  deposited  on  the  metal  in  a  thin  plate,  corresponding  to  the  former  in 
smoothness  and  polish ;  so  that  when  he  used  an  engraved  metal  matrix,  he  obtained 
an  impression  of  it  by  this  electric  agency.     "  On  detaching  the  precipitated  metal," 
says  he,  "  the  most  delicate  and  superficial  markings,  from  the  fine  particles  of  powder 
used  in  polishing  to  the  deeper  touches  of  a  needle  or  graver,  exhibited  their  corres- 
pondent impressions  in  relief  with  great  fidelity.     It  is,  therefore,  evident  that  this 
principle  will  admit  of  improvement,  and  that  casts  and  moulds  may  be  obtained 
from  any  form  of  copper.    This  rendered  it  probable  that  impressions  might  be  obtained 
from  those  other  metals  having  an  electro-negative  relation  to  the  zinc   plate  of  the 
battery.     With  this  view  a  common  printing  type  was  substituted  for  the  copper-plate, 
and  treated  in  the  same  manner.    This,  also,  was  successful ;  the  reduced  copper 
coated  that  portion  of  the  type  immersed  in  the  solution.    This,  when  removed,  was 
found  to  be  a  perfect  matrix,  and  might  be  employed  for  the  purpose  of  casting,  where 
time  is  not  an  object.     Casts  may  probably  be  obtained  from  a  plaster  surface  sur- 
rounding a  plate  of  copper,  &.c." 

On  the  12th  of  September  following  the  above  publication,  Mr.  Thomas  Spencer 
read  a  paper  "  On  Voltaic  Electricity  applied  to  the  purpose  of  working  in  Metal," 
before  the  Polytechnic  Society  of  Liverpool ;  which  he  had  intended  to  present  to  the 
British  Association  at  Birmingham  in  the  preceding  August,  but  not  being  well  received 
there,  he  exhibited  merely  some  electro-metallic  casts  which  he  had  prepared.  The 
Bociety  published  Mr.  Spencer's  paper,  and  thereby  served  to  give  rapid  diflusion  to  the 
practice  of  electro-metallurgy. 

One  of  the  most  successful  cultivators  of  this  art  has  been  Mr.  C.  V.  Walker, 
lecretarj'  to  the  London  Electrical  Society.  He  has  published  an  ingenious  little  work 
in  two  parts,  entitled  Electrotype  Manipulation,  where  he  presents,  in  a  lucid  manner, 
the  theory  and  practice  of  working  in  metals,  by  precipitating  them  from  their  solutions 
through  the  agency  of  voltaic  electricity.  His  first  part  is  devoted  to  the  explanation 
of  principles,  to  the  preparation  of  moulds,  to  the  description  of  the  voltaic  apparatus 
to  be  used,  to  bronzing,  to  coating  busts  with  copper,  to  the  multiplication  of  engraved 
plates,  and  to  the  deposition  of  other  metals. 


630 


ELECTRO-METALLURGY. 


\t 


n 


^ 


« 


F^g.  479.  represents  a  si!>gle-cell  voltaic  apparatus  for  electro-metallui^y.     z  is 
479  a  rod  of  amalgamated   zinc,  m  is  the  mould   on   which  the  metal 

is  to  be  deposited;  tr,  is  the  wire  joining  them;  c  is  a  strong 
solution  of  sulphate  of  copper  in  the-  lau-ge  vessel;  p,  is  a  tube 
or  cylinder  of  porous  earthenware,  standing  in  the  other,  and 
containing  dilute  sulphuric  acid.  The  solution  of  blue  vitriol  is 
kept  saturated,  during  the  progress  of  its  depositing  copper,  by 
^  piling  crystals  of  the  salt  upon  the  shelf,  shown  by  the  dots  under  p. 
The  mould  to  be  coated  should  not  be  too  small  in  reference  to 
the  surface  of  zinc  under  voltaic  action.  The  time  for  the  depo- 
sition to  be  effected  depends  upon  the  temperature;  and  is  less  the 
higher  this  is  within  certain  limits;  and  at  a  freezing  temperature 
it  ceases  almost  entirely.  When  a  mould  of  fusible  metal  is  used, 
it  should  not  be  placed  in  the  voltaic  apparatus  till  everything 
is  arranged,  otherwise  oxide  will  be  deposited  upon  it,  and  spoil 
the  effect.  When  the  circuit  is  completed  the  mould  may  be  im- 
mersed, but  not  before.  Wax  moulds  are  rendered  electric  con- 
ductors, and  thereby  depositors  as  follows :  After  breathing  on 
the  wax,  rub  its  surface  with  a  soft  brush  dipped  in  plumbago ;  breathing  and 
rubbing  alternately  till  the  surface  be  uniformly  covered.  Attach  a  clean  wire 
to  the  back  of  the  mould,  connecting  it  by  plumbago  with  the  blackened  wax. 
Sealing-wax  is  coated  in  like  manner.  Casts  of  Paris  plaster  are  first  well  im- 
bued with  melted  wax  or  tallow,  and  then  black-leaded.  Objects  in  Paris  plaster 
should  be  thoroughly  penetrated  with  hot  water,  but  not  wet  on  the  surface, 
before  wax  casts  are  made  from  them.  Moulds  are  best  taken  from  medals  in  stearine 
(stearic  acid).  For  plating  and  gilding  by  electro-chemical  agency,  the  following 
simple  plan  of  apparatus  is  used.  Fig.  480,  is  a  rectangular  porcelain  vessel,  which 
contains  in  its  centre  a  porous  cell  for  containing  the  solution  of  oxide  of  silver  or 
gold,  by  means  of  cyanide  of  potassium  ;  and  this  porous  cell  is  surrounded  at  a  little 
distance  by  a  similarly  formed  vessel  of  zinc.  The  connexion  is  formed  between  the 
zinc  and  the  suspended  object  to  be  coated,  either  by  a  pinching  screw,  or  by  the 
pressure  of  its  weight  upon  the  wire.  The  dilute  acid  which  excites  the  zinc  should, 
in  this  case,  be  very  weak,  in  reference  to  the  strength  of  the  cyanide  solution,  which 
■hould  be  recruited  occasionally  by  the  addition  of  oxide. 

It  has  been  found  that  with  cyanide  solutions  of  gold  and  shfer  in  the  electro- 
chemical  apparatus,  the  nascent  cyanogen  at  the  positive  pole  or  plate,  in  a  decon^ 
position  cell,  will  act  upon  and  dissolve  gold  and  silver.  Two  oi  three  of  Daniell*i 
cylindric  cells,  as  shown  at  a  in  fig.  481,  of  a  pint  size,  for  actij^^  upon  solutions  of 


jold  or  silver,  will  in  general  suffice.  The  decomposition  cell  b  is  made  of  glass  or 
porcelain.  The  zinc  may  be  amalgamated,  and  excited  with  brine ;  the  copper  cell 
contains,  as  usual,  a  solution  of  blue  vitriol.  To  the  end  of  the  wire  attached  to  the 
copper  cylinder  of  the  battery,  a  plate  of  silver  or  gold  is  affixed ;  and  to  the  end  of 
the  wire  attached  to  the  zinc  cylinder  is  affixed  the  mould,  or  surface,  to  be  plated  or  gilt. 
The  plates  of  silver  or  gold  and  zinc  should  be  placed  face  to  face  as  shown  in  the  figure 
in  the  decomposition  cell ;  which  is  filled  by  the  cyanide  solution.  A  certain  degree 
Df  heat  favors  the  piocesses  of  electro-gilding  and  plating.  The  surface  is  dead  as  first 
obtained,  but  it  may  be  easily  polished  with  leather  and  plaie-powder,  and  burnished  in 
whole  or  in  parts  with  a  steel  or  agate  tool. 


ELECTRO-METALL  URGY. 


631 


In  March,  1840,  Messrs.  Elkington  obtained  a  patent  for  the  use  of  pru»date  of 
potanh,  as  a  solvent  for  the  oxides  "of  gold  and  silver  in  the  electro-chemical  apparatus 
for  plating  and  gilding  metals.  They  also  «  sometimes  employ  a  solution  of  protoxide 
(purple  of  Cassius)  in  the  muriates  of  potash,  &c."  The  chemical  misnomers,  in  their 
specification,  are  very  remarkable,  and  do  great  discredit  to  the  person  employed  to 
draw  it  up.  Prussiate  of  potash  is  the  ordinary  commercial  name  of  a  saU  very  different 
from  the  cyanide  of  potassium — the  substance  really  meant  by  the  patentees — and  the 
purple  of  Cassius  is  very  different  from  protoxide  of  gold. 

In  plating  or  gilding  great  care  must  be  bestowed  in  making  the  articles  clean,  bright, 
and  perfj2tly  free  from  the  least  film  of  grease.  For  this  purpose,  they  should  be 
boiled  in  a  solution  of  caustic  alkali,  then  scoured  with  sand  and  water,  next  dipped 
into  a  dilute  acid,  and  finally  rinsed  with  water.  A  solution  of  the  nitrate  or  cyanide 
of  mercury  may  also  be  used  with  advantage  for  cleaning  surfaces.  The  following 
metals  have  been  deposited  by  electro-chemistry : — 

Gold,  platinum,  silver,  copper,  zinc,  nickel,  antimony,  bismuth,  cobalt,  palladium, 
cadmium,  lead,  and  tin ;  of  these,  the  first  five  are  the  most  important  and  valuable. 
The  gilding  solution  may  be  prepared  by  placing  slips  or  sheets  of  gold  in  a  solution 
of  cyanide  of  potassium,  and  attaching  to  the  negative  pole  of  a  voltaic  battery,  a  small 
plate  of  gold,  but  to  the  positive  pole  a  much  larger  one ;  whereby  the  latter  com- 
bines with  the  cyanogen,  under  the  influence  of  positive  electricity,  and  forms  a  solu- 
tion. Or,  oxide  of  gold,  precipitated  from  the  chloride  by  magnesia,  may  be  dissolved 
in  the  solution  of  the  cyanide. 

For  making  copper  medals,  &c.,  a  plate  of  amalgamated  zinc  is  to  be  put  into  a 
vessel  of  unglazed  earthenware,  or  of  any  other  porous  substance,  filled  with  dilute  sul- 
phuric acid  ;  which  vessel  is  set  into  a  trough  of  glass,  glazed  pottery,  or  pitched  wood, 
containing  blue  vitriol  in  the  state  of  solution,  as  well  as  in  the  state  of  crjstals  upon  a 
perforated  shelf,  near  the  surface  of  the  liquid. 

The  moulds  to  be  covered  with  copper  are  to  be  attached  by  a  copper  wire  to  the 
zinc  plate.  The  surface  of  zinc  excited  by  the  acid  should  be  equal  to  that  of  the 
moulds ;  with  which  view  a  piece  of  zinc,  equivalent  in  size  to  the  mould,  should  be 
suspended  in  front  of  it.  •        r  r  •  i 

For  depositing  copper  upon  iron,  Messrs.  Elkington  use  a  solution  of  ferrocyanide 
of  copper  in  cyanide  of  potassium  in  the  decomposition  trough,  instead  of  sulphate  of 
coppet,  neutralized  from  time  to  time  with  a  little  caustic  alkali,  as  in  the  commoE 
practice  ot  making  medals,  &c.,  of  copper.  I  should  imagine  that  the  black  oxide  of 
copper  dissolved  in  solution  of  cyanide  of  potassium  would  answer  better ;  as  the  iron 
in  the  ferrocyanide  might  be  rather  injurious.  The  iron  to  be  coppered  being  previously 
well  cleaned  from  rust,  &c.,  with  the  aid  of  a  dilute  acid,  is  to  be  plunged  into  the 
cyanide  solution  heated  to  120°  Fahrenheit,  and  connected  by  a  wire  with  the  negative 
pole  of  a  voltaic  battery,  as  formerly  described.  In  from  five  to  ten  minutes,  the  iron 
will  be  completely  coated.  It  is  then  to  be  scoured  with  sand,  and  plunged  into  solution 
of  sulphate  of  copper ;  whereby  it  will  show  black  spots  wherever  there  are  any  defec- 
tive places.  In  this  case,  it  is  to  be  cleaned  and  replaced  under  the  cyanide  solution, 
in  the  decomposition  cell  for  a  minute  or  two.  Zinc  may  be  deposited  from  a  solution 
of  its  sulphate  by  a  like  arrangement. 

Metallic  cloth  may  be  made  as  follows  : — On  a  plate  of  copper  attach  quite  smoothly 
a  stout  linen,  cotton,  or  woollen  cloth,  and  connect  the  plate,  with  the  negative  pole  of 
a  voltaic  battery :  then  immerse  it  in  a  solution  of  copper  or  other  metal,  connecting  a 
piece  of  the  same  metal  as  that  in  the  solution  with  the  positive  pole ;  decomposition 
takes  place,  and  the  separated  metallic  particles  in  their  progress  toward  the  metal 
plate  or  negative  pole,  insinuate  themselves  into  the  pores  of  the  tissue,  and  form  a  com- 
plete sheet  of  flexible  metal.  Lace  is  metallized  by  coating  it  with  plumbago,  and  then 
subjecting  it  to  the  electro-metallurgic  process. 

The  gilding  solution  should  be  used  in  the  electric  process  at  a  temperature  of 
130*  F.  The  more  intense  the  electric  power,  the  denser  and  harder  is  the  metallic 
coat  deposited. 

Metallic  silver  may  be  combined  with  cyanogen  by  subjecting  it  to  the  joint  action 
of  a  solution  of  cyanide  of  potassium  and  positive  electricity.  Or  cyanide  of  silver  may 
be  precipitated  from  the  nitrate  by  a  little  cyanide  of  potassium,  and  afterward  dissolved 
by  means  of  an  excess  of  cyanide  of  potassium.  The  quantity  of  electric  power  or  sur- 
face-size of  the  battery  should  in  all  cases  be  proportioned  to  the  surface  of  the  articles 
to  be  placed  or  gilt,  and  the  electric  intensity  or  number  of  sets  of  jars  proportioned  to 
the  density  of  the  solution.  Plating  is  accomplished  in  from  4  to  6  hours.  The  articles 
ihould  be  weighed  before  and  after  this  operation,  to  ascertain  how  much  silver  they 
kave  taken  on. 

Messrs.  Elkington  make  their  moulds  with  wax,  combined  with  a  little  phosphorus. 
Which  reduces  upon  their  surfaces  a  thin  film  of  gold  or  silver,  from  solutions  of  these 


f 


632 


ELECTRO-METALLURGY. 


ELECTROTYPIE. 


633 


, 

1 

1 

i 

i 

1 

1 

1 

'':! 

jj 

I 

1 

l! 

i 

i 

i)i( 


metals,  which  films  are  hetter  than  the  black-leaded  surfaces  for  receiving  the  copper 
deposit.     They  also  recommend  to  add  a  little  alkali  to  the  solution  of  sulphate  of 
copper,  intended  to  afford  a  deposite  of  metal.     The  single  cell,  first  described  above, 
is  best  adapted  for  this  purpose. 

M .  Ruolz  employs  for  gilding,  a  solution  of  snlpharet  of  gold  in  sulphuret  of  p^^tas- 
sium,  which  he  prepares  by  precipitating  a  solution  of  gold  in  aqua  regia,  by  sulphu- 
retted hydrogen,  and  redissolving  the  precipitate  with  sulphuret  of  potassium.  By 
the  use  of  this  solution  of  gold,  he  obtains  a  very  beautiful  and  solid  gilding,  and  at  less 
expense  than  with  cyanide  of  potassium.  Every  metal  which  is  a  negative  electrode  to 
gold  may  be  gilded. 

Platinizing  is  effected  best  by  means  of  a  solution  of  the  potash-chloride  of  platinum 
m  caustic  potash.  1  milligramme  (0-015  grain)  covers  completely  a  surface  of  50 
square  centimeters  (2  inches  square) ;  the  film  of  platinum  is  only  one  hundridth  of  a 
niilligramme  thick. 

M.  BoBttger  has  shown  that  we  may  easily  tin  copper  and  brass  in  the  moist  way  by 
dissolvmg  peroxide  of  tin  (putty)  in  hydrate  of  potash  (caustic  potash  ley),  putting  at 
the  bottom  of  the  vessel  holding  that  solution  some  turnings  of  tin,  setting  the  piece  of 
copper  or  brass  upon  the  turnings,  and  makinar  the  liquor  boil.  An  electric  current  is 
produced  by  the  contact  of  the  dissimilar  metals ;  and  as  the  tin  is  withdrawn  by  the 
copper  or  brass  from  the  solution,  it  is  restored  to  it  by  the  turnings.  Zinking  may  be 
done  in  the  same  way  ;  by  putting  pieces  of  zinc  into  a  concentrated  solution  of  chlorine, 
by  setting  the  piece  of  metal  to  be  zinked  in  contact  with  these  pieces,  and  applying  heat 
to  the  vessel  containing  the  whole. 

For  certain  new  methods  of  constructing  and  arranging  voltaic  batteries  for  electro- 
inetallurgic  operations,  a  patent  was  obtained  by  Dr.  Leeson  in  June,  1842. 

Fig.  482,  is  a  longitudinal  section  of  the  batterj-,  and  ^g.  483,  a  plan  view  of  the  frame 
to  which  the  metal  plates  are  attached,  o  is  a  rectangular  wooden  trough,  containing 
a  wooden  frame  b,  formed  with  vertical  grooves  in  its  sides,  to  receive  a  series  of  porous 
cells  c,  c,  c.  The  plates  of  the  battery  are  suspended  in  the  fluid  or  fluids  by  brass 
lorks  d,  d,  fastened  to  a  wooden  frame  e,  e,  which  rests  upon  the  trough  a,  and  is  con- 
nected to  the  other  frame  6,  by  two  pins/,  when  they  are  required  to  be  raised  together 
out  of  the  trough  a,  a. 

The  battery  may  be  charged  as  usual  with  one  or  two  fluids  ;  one  of  them  in  the  latter 
ease  being  contained  in  the  porous  cells  c,  c,  e :  and  plates  of  copper  and  zinc  or  any 
other  suitable  metals  may  be  employed.  ' 

The  second  improvement  consists  in  cleaning  copper  and  zinc  plates  after  they  have 
been  used  in  a  battery,  by  the  employment  of  a  voltaic  battery;  and  also  in  amalga- 

483 


482 


mating  or  coating  with  mercury  the  surfaces  of  zinc  plates,  by  the  same  means  to  render 
them  suitable  for  being  used  in  the  construction  of  the  voltaic  apparatus. 

The  third  improvement  consists  in  exciting  electricity  by  a  combination  of  nitric, 
sulphuric,  or  muriatic  acid,  with  any  of  the  following  substances;  viz,  impure  ammoni- 
acl  or  lime  liquor  of  the  gas  works,  solutions  of  alkaline  and  earthy  sulphurets,  the 
alkalies  and  their  carbonates,  or  lastly,  the  acidulous  sulphate  of  iron  generated  from 

^"^  AnouVer^f  Dr.  Leeson's  manifold  improvements  for  depositing  metallic  alloys  con- 
siste  in  the  employment  of  one  battery,  "  with  the  alternating  cathode,  represented  m 
fig  484  It  is  composed  of  a  beam,  a,  mounted  on  the  shaft,  6,  which  turns  in  bearings 
carried  by  standards,  c  ;  the  beam  communicates  with  the  anode  of  the  battery  by  the 
wire,  d,  and  a  vibrating  motion  is  given  to  it  by  the  rod,  e,  from  the  shatt,/,  which  is 
driven  by  an  electro-magnetic  engine,  or  any  other  suitable  prime  mover,  g,  g,  are 
two  vessels  containing  mercury,  connected  by  wires,  h,  h,  with  the  cathode  plates  ot 
the  two  metals  composing  the  alloy  (but  if  the  alloy  is  to  consist  of  more  than  two  metals, 
then  more  vessels,  a,  will  be  required,  one  for  each  cathode  plate);  these  plates  are 
immersed  in  a  solution  composed  of  similar  salts  of  the  diflferent  metals  to  be  deposited, 
to«rether  with  the  anode,  or  surface  to  be  deposited  upon,  which  is  connected  by  a  wire 
wfth  the  cathode  of  the  battery.  A  communication  is  established  between  the  two 
cathode  plates,  or  supply  of  metals,  and  the  anode  of  the  battery,  by  means  of  the  rods, 
t  i  which  are  caused,  by  the  vibration  of  the  beam,  a,  to  dip  alternately  into  either  the 
one  or  the  other  of  the  vessels,  g;  and  thus  each  metal  will  be  deposited  on  the  article 
to  be  coated  during  the  time  that  the  connection  is  established  between  it  and  the  bat- 
tery, by  the  immersion  of  its  rod  into  the  vessel  of  mercury.  The  relative  proportions 
of  the  two  metals  is  adjusted  by  lengthening  or  shortening  the  rods,  i,  i,  as  shown  m 
the  fi<«-ure,  so  that  they  may  be  immersed  for  a  longer  or  shorter  period  in  the  mercury. 

Where  the  electrical  current  enters  the  electrolyte,  is  the  anode;  where  it  leads  it, 
is  the  cathode.  .         .  _ 

The  patentee  describes  ten  other  improvements,  which  seem  to  be  ingenious,    tsee 

Newton*s  Journal,  xxii.  292.  tv      i       i  i.  a 

ELECrrROTYPIE  by  TnERMO-ELECTRicrry.  1.  For  silvering.— VissoUe  1  troy  ponna 
of  silver  in  nitiic  acid,  dilute  with  a  gallon  of  water,  precipitate  the  silver  by  solution 
of  carbonate  of  soda  (1  lib.)  at  100^  Fahr. ;  wash  the  precipitate  on  the  filter  with 
warm  water.  In  another  vessel  dissolve  8  libs,  of  hyposulphite  of  soda  in  2|  gallons 
of  water  at  100°,  add  1  lib.  of  carbonate  of  soda  with  the  carbonate  of  silver,  stirring 
until  the  silver  be  dissolved.  Filter  the  solution  for  use.  It  is  advantageous  to  add 
1  lib.  avoirdupois  of  hyposulphite,  and  one-third  of  a  pound  of  carbonate  of  soda  for 
every  pound  troy  of  silver  that  may  be  deposited.  ^ 

2.  Gold  solution,— One  ounce  troy  of  fine  gold  is  dissolved  in  nitro-muriatic  acid,  and 
the  solution  is  evaporated  till  it  assumes  a  deep  red  color,  and  crystallizes  upon  cool- 
in«'.  Dilute  with  a  pint  of  pure  water  and  filter.  Heat  this  solution  to  about  200° 
Faiir.  and  precipitate  the  gold  by  water  of  ammonia.  Wash  the  precipitate  well  on 
the  filter  with  hot  water.  Dissolve  this  gold  in  1  gallon  of  water  containing  8  ounces 
of  hyposulphite  of  soda,  and  boil  together  for  an  hour.  The  solution  when  filtered  is 
fit  for  use.  In  gilding,  this  solution  may  be  warmed  to  about  130°  Fahr.  A  small 
anode  of  gold,  of  about  one-tenth  the  size  of  the  article  to  be  gilded,  and  a  current  of 
two  pairs  of  common  galvanic  plates,  are  used. 

3.  Copper  solution.— Dissolve  1  pound  of  carbonate  of  copper  m  8  pounds  of  hypo- 
sulphite of  soda,  and  1  pound  of  carbonate  of  soda  dissolved  in  2^  gallons  of  distilled 
water  at  100°  Fahr.,  or  thereabouts,  and  filtered  to  obtain  a  clear  solution.  It  is  then 
fit  for  use,  with  currents  of  electricity  at  100°  Fahr.  ^ 

Description  of  the  thermo-electric  battery.— 100  pieces  of  German  silver,  containing 
from  20  to  25  per  cent  of  nickel,  and  100  pieces  of  iron,  each  piece  being  1  inch 
broad,  1  foot  long,  and  one-eighth  of  an  inch  in  thickness.  These  200  pieces 
are  soldered  to  each  other,  so  that  iron  is  always  combined  with  German  silver. 
To  get  a  compact  form,  10  rows  must  be  first  arranged  (every  one  of  20  pieces  or 
10  pairs),  and  these  rows  must  be  so  soldered  tx)  each  other  that  they  are  parallel,  and 
the  whole  take  the  form  of  a  square  ;  taking  care  that  the  several  pieces  are  soldered 
totrether  in  such  a  way  that  iron  will  always  be  in  connection  with  German  silver. 
When  the  whole  is  united,  it  is  placed  in  a  rim  or  frame  of  iron  y>late,  1  foot  2  inf'VJs 
high  but  so  that  the  metals  do  not  touch  each  other,  nor  the  iron  rim  or  frame,  and  fill 
the  rim  with  plaster  of  Paris  or  clay,  so  that  all  soldered  parts  of  the  series  of  plates 
or  bars  are  uncovered,  that  is,  the  under  ends  1  inch,  and  the  upper  ends  3  inches. 
The  clay  is  covered  at  the  surface  with  a  laver  of  pilch.  The  frame  containing  the 
series  of  bars  or  plates,  is  so  placed  that  the'lower  end  of  the  series  (1  inch)  dip  into 
a  sand  bath  which  is  heated  nearly  to  redness.     The  upper  ends  (3  inches)  are  to 


634 


ELEMENTS. 


EMBALMING. 


635 


f ' 


ii 


be  kept  as  cold  as  possible,  and  for  this  purpose  a  current  of  cold  water  is  caused  to 
flow  from  one  vessel  over  this  battery  to  another  vessel.  The  upper  end  of  the  metals 
v3  inches)  may  be  covered  with  a  lac  or  varnish.  There  is  an  anode  wire  leading  from 
the  German  silver  plate ;  and  an  artule  wire  leading  from  the  iron  plate. 

The  thermo-electric  apparatus  is  intended  for  the  deposition  of  metals,  from  the  above 
described  solutions 

ELEMENTS  (Eng.  and  Fr.;  Grundstoffe,  Germ.)  Tlie  ancients  considered  fire,  air, 
water,  and  earth,  as  simple  substances,  essential  to  the  constitution  of  all  terrestrial 
bemgs.  This  hypothesis,  evidently  incompatible  with  modern  chemical  discovery, 
may  be  supposed  to  correspond,  however,  to  the  four  states  in  which  matter  seems  to 
exist ;  namely,  1.  the  unconfinable  powers  or  fluids,— caloric,  light,  electricity ;  2.  pon- 
derable gases,  or  elastic  fluids;  3.  liquids;  4.  solids.  The  three  elements  of  the  alche- 
mists, salt^  earth,  mercury,  were,  in  their  sense  of  the  words,  mere  phantasms. 


I 


Deaoininatioa  of  the  Substances. 


Aluminium  .  .  . 

Antimony  .  .  . 

Arsenicum  .  .  . 

Barium    •  .  .  . 

Bismuth  -  .  .  . 

Boron      •  .  .  . 

Brome     -  .  .  . 

Cadmium  .  .  . 

Calcium  -  -  .  . 

Carbon    -  .  .  . 

Cerium  (Marignac)  - 

Chlorine  -  .  .  . 

Chromium  .  .  . 

Cobalt      -  -  .  . 

Copper    -  .  .  . 

Didymium  (Marignac) 

Erbium  -  .  . 

Fluorine  -  .  -  . 

Gold         .  .  .  . 

Glucinium  -  -  . 

Hydrogen  .  .  . 

Iodine     •  .  .  . 

Iridium   -  .  .  . 

Iron         .  .  .  . 

Lantbanium  (Marignac) 

Lead        .  .  .  . 

Lithium  -  .  .  . 

Magnesium        .  .  . 

Manganese        .  .  . 

Mercury  -  -  -  . 

Molybdenum      -  .  . 

Nickel     -  .  .  . 

Niobium  .... 

Nitrogen-  .  .  . 

Norium   -  -  .  . 

Osmium  •  .  .  . 

Oxygen   .... 

Palladium  ... 

Pelopium  ... 

Phosphorus        ... 

Platinum  ... 

Potassium  ... 

Rhodium  ... 

iluthenium,  according  to  Claus 

Selenium  ... 

Silicium  -  .  .  . 

Silver      -  -  .  . 

Sodium    •  .  .  . 

Sulphur   .... 

Strontium  ... 

Tantaliam  ... 

Tellurium  ... 

Terbium  .... 
Thorium .  .  .  - 

Titanium-  ... 

Tin  .... 

Tungsten  ... 

Uranium  .... 
Vanadium  .  .  - 

Yttrium  .... 
Zinc  .... 
Zirconium         ... 


c 
.o 

E 


Al. 

Sb. 

As. 

Ba. 

Bi. 

B. 

Br. 

Cd. 

Ca. 

C. 

Ce. 

CI. 

Cr. 

Co. 

Cu. 

D. 

E. 

Fl. 

Au. 

G. 

H. 

I. 

Ir. 

Fe. 

La. 

Pb, 

LI 

Mg. 

Mn. 

Hg. 

Mo. 

Ni. 

Nb. 

N. 

No. 

Os. 

O. 

Pd. 

Pe. 

P. 

Pt. 

K. 

R. 

Ru. 

Se. 

SL 

Ag. 

Na. 

S. 

Sr. 

Ta. 

Te. 

Tb. 

Th. 

Ti. 

Sn. 

W. 

u. 

V. 
Y. 

Zn. 
Zr. 


I.  Equivalents. 


0=100. 


170-900 
16I2£K)3 
938-800 
«55  290 
1330-377 
136  204 
999-620 
696767 
251-651 
75-120 
590-800 
443  280 
328-870 
368.650 
395-600 
620000 

2a5433 

24.58  330 

87-124 

12-480 

1585-992 

1232-080 

350-527 

588 -(100 

1294-645 

81660 

158140 

344.684 

1251-290 

596-100 

S69  330 

175-060 

1242-624 
100  000 
655.477 

892-041 

1232080 

488-856 

651-962 

6.51-000 

495-285 

277-778 

1349-660 

289-729 

200-750 

545  929 

1148  365 

801-760 

743  860 
301-550 
735-294 
1188-360 
742-875 
856-892 

406-591 
419-728 


H=l. 


13  694 
129-269 
75-224 
68-533 
106-600 
10-914 
80-098 
55  831 
20-164 
6-019 
47-261 
35517 
26  352 
29-539 
31-699 
49-600 

18-865 

196  982 

69(il 

1-000 

127082 

98-724 

28-087 

47-(«0 

103-738 

6-543 

12671 

27-619 

100-026 

47-764 

29-594 

14-027 

99-569 

8-000 

53-323 

31.414 
98-724 
39171 
52-240 
52-163 
39  686 
22  258 
108146 
23215 
16-086 
43744 
92-016 
64-244 

59-604 
24-158 
58-918 
95-220 
59-525 
68-661 

32-579 
33«32 


II.  Atomic  Weights. 


O=I00. 


170-9<i0 
806-452 
4694(10 
85.5-290 
1330  377 
136-204 
499-810 
696-767 
250000 
75120 
590  800 
221-640 
328-870 
368  650 
3956(10 
620-000 

117-717 

1229-165 

87-124 

6-240 

792  996 

1232080 
a50-527 
588  000 

1294  645 

81-660 

158-140 

344^84 

1250-000 
596-100 
369-330 

87-530 

1242-624 
100.000 
665-477 

196021 

1232-080 

488  856 

651-962 

651-000 

4*5-285 

277-778 

1349-660 

289-729 

200-750 

545-929 

1148  365 

801-760 

743.860 
301-550 
735294 
188-360 
742-875 
856-892 

406-591 
419-728 


H=I. 


27-388 

129-239 

75-224 

137-(;66 

213-200 

21-828 

80098 

111-662 

40-000 

12-038 

94-528 

35517 

52-704 

59-078 

63-398 

99-200 

18-865 

196  982 

13962 

1-000 

127-082 

197-448 

56-174 

94-080 

207-476 

13-086 

25342 

55  238 

200-000 

9.5528 

59-188 

14027 

199-138 

16-000 

106  646 

31-414 

197-448 

78-342 

104-326 

104-326 

79-372 

44-516 

216-292 

46  430 

32-171 

87-488 

184  032 

128  488 

119-208 
48-316 
117-836 
190-442 
119050 
137-322 

65158 
67  264 


III.  Equivalents  (aOer 
Gerbatdtand  Laurent). 


0=100. 


85-63 

403-25 

468  50 

425  00 

1312-50 

67-50 
500-00 
350-00 
125-00 

7500 

221-87 
162-50 
185-00 
198.75 


116-85 
1225-00 

6-25 
787-50 

17500 

650-00 

40-16 

75-00 

175-00 

625-00 

18500 

87  50 


10000 


200-00 
618-75 
243-75 


490-90 
87-50 
675  00 
143-75 
200-00 
275-00 

800-00 


368-75 
60000 
750-00 


206^ 


H=l. 


13-70 
64  50 
7500 
68  00 
210-00 
10-80 
80-00 
5600 
2000 
12-00 

35-60 
26  00 
29  60 
31-80 


18-60 
19600 

1-00 
126-00 

28-00 

104-00 

6-40 

12  00 

2800 

100  00 

29«) 
1400 

16-00 


8200 
99  OO 
8900 


78-50 
1400 
108-00 
23  00 
32-00 
44-00 

128^0 


59-00 

96-00 

12000 


33-00 


In  modern  science,  the  term  Element  signifies  merely  a  substance  which  has  not  yet 
Deen  resolved  by  analysis  into  any  simpler  form  of  matter ;  and  it  is  therefore  synonymous 


with  undecoranounded.  This  class  comprehends  62  different  bodies,  of  which  no  less 
than  52  are  metallic.  Five  may  be  styled  Archceal,  from  the  intensity  and  universality 
of  their  affinities  for  the  other  bodies,  which  they  penetrate,  corrode,  and  apparently 
consu.ne  wit  h  the  phenomena  of  light  and  heat  These  5  are  chlorine,  oxygen,  iodine, 
hrmnine' fluorine.  Eight  elements  are  eminently  inflammable  when  acted  upon  by  any 
of  tlie  preceding  five,  and  are  thereby  converted  into  incombustible  compounds.  Ihe 
simple  non-metallic  inflammables  are  hydrogen,  azote,  mlphur,  phosphorus,  selenium, 

carbon,  boron  silicon.  ,,,,.      .,,i,-i       a 

The  preceding  table  exhibits  all  the  undecompounded  bodies  in  alphabetical  ordei% 
with  their  prime  equivalent  numbei-s,  atomic  weights,  or  reciprocal  combining  and 
saturating  proportions,   in  reference  to  oxygen   and   hydrogen,   reckoned    100,000, 

The  numbers  contained  in  columns  I.  and  II.  are  deduced  from  those  given  by 
Berzelius,  in  the  fifth  edition  of  his  Lehrbuch  ;  and  in  column  III.  those  atomic  weighU 
are  added  which  Gerhardt  and  Laurent  have  quoted  in  the  first  number  of  the  fifth 

volume  of  the  Comptes  Rendus.  ,  ^     ,  ,  •         i.      •  * 

The  following  is  a  table  of  atomic  weights  corrected  and  fixed  by  various  chemista 

in  recent  times: — 


Denomination  of  the  Substances. 


Calcium  (Erdmann  and  Marchand) 
Carbon  (ditto) 

Hydrogen  ... 

Iron  (Erdmann  and  Marchand) 
Mercury  (ditto)     - 

Phosphorus  (Pelouze)  - 
Sodium  (diUo^ 

Strontium        (ditto) 
Sulphur  (Erdmann  and  Marchand) 


5 

E 
>> 
w 


Ca. 
C. 
H. 
Fe. 

rr- 

Na. 

Sr. 

S. 


Equivalents. 


0=100. 


250-000 

75000 

12000 

350-000 

1250  000 

400-000 

287-170 

M8-020 

200-000 


H=l 


Atomic  Weij^hta. 


20000 

6-000 

1000 

23-000 

100-(HX) 

32-024 

22-973 

43-841 

16000 


OailOO. 


H=rl. 


250-000 

75000 

6250 

250-100 

1250000 

200-150 

287-170 

548020 

200-000 


40-000 
12000 
1-000 
56-000 
200-000 
32-024 
45-046 
87«82 
32i)06 


Within  the  last  few  years  the  following  atomic  weights  have  been  revised: — 


Barium  - 

Calcium  - 

Chromiunti 

Chromium 

Fluorine 

Magnesium 

Magnesium 

Magnesium 

Molybdenum 

Molybdenum 


Ba.  856*770  Marignac. 

Ca.  350.000  Erdm.  and  March. 

Cr.  833-500  Lefort 

Cr.  835  091  Moberg. 

Fl.  237-500  Louyet 

Mg.  162-550  Jacquelain. 

Mg.  164-490  Svanberg. 

Mg.  160.000  March,  and  Scheer. 

Mo.  574-750  Berlin. 

Mo.  574-829  Svanb.  and  Struve. 

W.  1150-780  Schneider. 


Tungsten 

ELEMI  is  a  resin  which  exudes  from  incisions  made  during  dry  weather  through 
the  bark  of  the  amyris  elemifera,  a  tree  which  grows  in  South  America  and  Brazil.  It 
comes  to  us  in  yellow,  tender,  transparent  lumps,  which  readily  soften  by  the  heat  of 
the  hand.  They  have  a  strong  aromatic  odor,  a  hot  spicy  taste,  and  contain  12|  per 
cent  of  etherous  oil.  The  crystalline  resin  of  elemi  has  been  called  Elemine.  It  ia 
used  in  making  lacquer,  to  give  toughness  to  the  varnish.  .      ,  , ,         , 

ELUTRIATE.  \Soutirer,  Fr.;  Schlemmen,  Germ.)  When  an  insoluble  pulve- 
rulent matter,  like  whitening  or  ground  flints,  is  diflfused  through  a  large  body  of 
water,  and  the  mixture  is  allowed  to  settle  for  a  little,  the  larger  particles  will  subside. 
If  the  supernatant  liquid  be  now  carefully  decanted,  or  run  off,  with  a  syphon,  it  wUl 
contain  an  impalpable  powder,  which  on  repose  will  collect  at  the  bottom,  and  may  be 
taken  out  to  dry.    This  process  is  called  elutriation. 

EL  VAN.  The  name  given  by  the  Cornish  miners  to  porphyry,  as  also  to  the 
heteroo-eneous  rocky  masses  which  occur  in  the  granite  or  in  the  clay  slate,  deranging 
the  direction  of  their  metallic  veins,  or  even  the  mineral  strata ;  but  elvan  generally 
indicates  a  felspar  porphyry.  . 

EMBALMIiSG.  {Embaument,  Fr. ;  Einbalsamen,  Germ.)  Is  an  operation  in 
i^hich  balsams  {baumes,  Fr.)  were  employed  to  preserve  human  corpses  from  putrefac- 
tion; whence  the  name.  •       xu    v  j*        * 

The  ancient  Egyptians  had  recourse  to  this  process  for  preserving  the  boilies  ol 
numerous  families,  and  even  of  the  animals  which  they  loved  or  worshipped.  An 
excellent  account  of  their  methods  is  given  in  Mr.  Pettigrew's  work  upon  Mummies. 
Modern  chemistry  has  made  us  acquainted  with  many  means  of  counteracting  putre- 


I*       n  a    WjA 


\\\ 

'      «       : 


f 


636 


EMBOSSING  CLOTH. 


faction  more  simple  and  efBeacions  than  the  Egyptian  system  of  salting,  8moV;i».gi 
spicing,  and  bitumenizing.     See  Putrefactiox. 

EMBOSSING  CLOTH.  Mr.  Tbunas  Greig,  of  Rose  Bank,  near  Bury,  patented 
an  invention,  in  November,  1835,  which  consists  in  an  ingenious  construction  of  ma- 
chinery for  both  embossing  and  printing  silk,  cotton,  woollen  cloth,  paper,  and  othei 
fabrics,  in  one  or  more  colors,  at  one  operation. 

Figs.  486,  486  represent  three  distinct  printing  cylinders  of  copper,  or  other  suitabU 

'^  ~  material,  a,   d,   c,   with 

their  necessary  appen- 
danges  for  printing  three 
different  colors  up>on 
the  fabric  as  it  passes 
through  the  machine 
either  of  these  cylinder! 
A,  B,  or  c,  may  be  em« 
ployed  as  an  embossing 
cylinder,  without  per« 
forming  the  printing  pro* 
cess,  or  may  be  made  t« 
effect  both  operations  at 
the  same  time. 

The  fabric  or  goods 
to  be  operated  upon  be- 
ing first  wound  tightly 
upon  a  roller,  that  roller 
is  to  be  mounted  upon 
an  axle  or  pivot,  bearing 
in  arms  or  brackets  at 
the  back  of  the  machine, 
as  shown  at  d.  From 
this  roller  the  fabric 
a  a  a  a  is  conducted  be- 
tween tension  rails,  and 
passed  under  the  bed 
cylinder  or   paper  bowl 

E,  and  from  thence  pro- 
ceeds over  a  carrier  roller 

F,  and  over  steam  boxes 
not  shown  in  the  draw- 
ing, or  it  may  be  con- 
ducted into  a  hot  room, 
for  the  purpose  of  drying 
the  colors. 

The  cylinders  A,  b, 
and  c,  havinar  neither  en- 
graved or  raised  surfaces, 
are  connected  to  feeding 
rollers  b  b  by  revolving 
in  the  ink  or  colored 
troughs  c  c  c ;  or  endless  ts,  called  sieves,  may  be  employed,  as  in  ordinary  printing 
machines,  for  supplying  the  color,  when  the  device  on  the  surface  of  the  cylinders  is 
raised :  these  cylinders  may  be  famished  with  doctors  or  scrapers  when  required,  or  the 
same  may  be  applied  to  the  endless  felts. 

The  blocks  have  adjustable  screws  g  g,  for  the  purpose  of  bringing  the  cylinders  np 
against  the  paper  bowl,  with  any  required  degree  of  pressure :  the  cylinder  b  is  support- 
ed by  its  gudgeons  running  in  blocks,  which  blocks  slide  in  the  lower  parts  of  the 
lide  frames,   and  are  connected    to  perpendicular  rods  t,  having  adjustable  screw 

nuts. 

The  lower  parts  of  these  rods  bear  upon  weighted  levers  fe  fe,  extending  in  front  of  the 
Hachme ;  and  by  increasing  the  weights  1 1,  any  degree  of  upward  pressure  may  be  givea 
to  the  cylinder  b. 

The  color  boxes  or  troughs  c  c  Cy  carrying  the  feeding  rollers  bbb,  are  fixed  on  boards 
«rhich  slide  in  grooves  in  the  side  frames,  and  the  rollers  are  adjusted  and  brought  into 
contact  with  the  surface  of  the  printing  cylinders  by  screws. 

If  a  back  cloth  should  be  required  to  be  introduced  between  the  cylindrical  bed  or 
Daper  bowl  e,  and  the  fabric  a  a  a,  as  the  ordinary  felt  or  blanket,  it  may,  for  printing 
and  embossing  cotton,  silk,  or  paper,  be  of  linen  or  cotton  ;  but  if  woollen  goods  are  to 
be  operated  upon,  a  cap  of  felt,  or  some  such  material,  must  be  bound  round  the  paper 


EMBOSSING  CLOTH. 


637 


bowl,  and  the  felt  or  blanket  must  be  used  for  the  black  cloth,  which  is  to  be  conducted 
over  the  rollers  h  and  l 

For  the  purpose  of  embossing  the  fabric,  either  of  the  rollers  a,  b,  or  c,  may  be 
employed,  observing  that  the  surface  of  the  roller  must  be  cut,  so  as  to  leave  the  pallera 
or  device  elevated  for  embossing  velvets,  plain  cloths,  and  papers ;  but  for  woollens  the 
device  must  be  excavated,  that  is,  cut  in  recess. 

The  pattern  of  the  embossing  cylinder  will,  by  the  operation,  be  partially  marked 
through  the  fabric  on  to  the  surface  of  the  paper  bowl  e  ;  to  obliterate  which  marks 
from  the  surface  of  the  bowl,  as  it  revolves,  the  iron  cylinder  roller  g  is  employed ;  but 
as  in  the  embossing  of  the  same  patterns  on  paper,  a  counter  roller  is  required  to 
produce  the  pattern  perfectly,  the  iron  roller  is  in  that  case  dispensed  with,  the  impres- 
sion given  to  the  paper  bowl  being  required  to  be  retained  on  its  surface  until  the  opera- 
tion is  finished. 

In  this  case  the  relative  circumferences  of  the  embossing  cylinder,  and  of  the  paper 
bowl,  must  be  exactly  proportioned  to  each  other ;  that  is,  the  circumference  of  the  bowl 
must  be  equal,  exactly,  to  a  given  number  of  circumferences  of  the  embossing  cylinder, 
very  accurately  measured,  in  order  to  preserve  a  perfect  register  or  coincidence,  as  they 
continue  revolving  between  the  pattern  on  the  surface  of  the  embossing  cylinder,  and 
that  indented  into  the  surface  of  the  paper  bowl. 

The  axle  of  the  paper  bowl  e,  turns  in  brasses  fitted  into  slots  in  the  side  frames,  ana 
it  may  be  raised  by  hand  from  its  bearings  when  required,  by  a  lever  /c,  extending  in 
front.  This  lever  is  affixed  to  the  end  of  a  horizontal  shaft  l,  l,  crossing  the  machine 
seen  in  the  figures,  at  the  bac.i  of  which  shaft  there  are  two  segment  levers  p,  p,  to  which 
bent  rods  q,  q,  are  attached,  having  hooks  at  their  lower  ends,  passed  under  the  axle  of 
the  bowl.  At  the  reverse  end  of  the  shaft  l,  a  ratchet-wheel  r,  is  affixed,  and  a  pall  or 
click  mounted  on  the  side  of  the  frame  takes  into  the  teeth  of  the  wheel  r,  and  thereby 
holds  up  the  paper  bowl  when  required. 

When  the  iron  roller  g,  is  to  be  brought  into  operation,  the  vertical  screws  /,  t,  mount- 
ed in  the  upper  parts  of  the  side  frames,  are  turned,  in  order  to  bring  down  the  brasses  M, 
which  carry  the  axle  of  that  roller  and  slide  in  slots  in  the  side  frames. 

The  cylinders  a,  b,  and  c,  are  represented  hollow,  and  may  be  kept  at  any  desired  tem- 
perature during  the  operation  of  printing,  by  introducing  steam  into  them ;  and  under  the 
color  boxes  c,  c,  c,  hollow  chambers  are  also  made  for  the  same  purpose.  The  degree  of 
temperature  required  to  be  given  to  these  must  depend  upon  the  nature  of  the  coloring 
material,  and  of  the  goods  operated  upon.  For  the  purpose  of  conducting  steam  to  these 
hollow  cylinders  and  color  boxes,  pipes,  as  shown  at  r,  v,  Vy  are  attached,  which  lead  from 
a  steam  boiler.  But  when  either  of  these  cylinders  is  employed  for  embossing  alone,  or 
for  embossing  and  printing  at  the  same  time,  and  particularly  for  some  kinds  of  goods 
where  a  higher  temperature  may  be  required,  a  red-hot  heater  is  then  introduced  into  the 
hollow  cylinder  in  place  of  steam. 

If  the  cylinder  b  is  employed  as  the  embossing  cylinder,  and  it  is  not  intended  to 
print  the  fabric  by  that  cylinder  simultaneously  with  the  operation  of  embossing,  the 
feeding  roller  6,  must  be  removed,  and  also  the  color  box  c,  belonging  to  that  cylin- 
der ;  and  the  cylinders  a  and  c,  are  to  be  employed  for  printing  the  fabric,  the  one 
applying  the  color  before  the  embossing  is  efl"ected,  the  other  after  it.  It  is  however 
to  be  remarked,  that  if  a,  and  c,  are  to  print  colors  on  the  fabric,  and  b  to  emboss  it, 
in  that  case  it  is  preferred,  where  the  pattern  would  allow  it.  a  and  c,  are  wooden  roll, 
ers  having  the  pattern  upon  their  surfaces,  and  not  metal,  as  the  embossing  cylinders  must 
of  necessity  be. 

It  will  be  perceived  that  this  machine  will  print  one,  two,  or  three  colors  at  the  same 
time,  and  that  the  operation  of  embossing  may  be  performed  simultaneously  with  the 
printing,  by  eithe."  of  the  cylinders  a,  b,  ore,  or  the  operation  may  be  performed  consecu- 
tively by  the  cylinders,  either  preceding  or  succeeding  each  other. 

The  situations  of  the  doctors,  when  required  to  be  used  for  removing  any  superfluous 
color  from  the  surface  of  the  printing  cylinder,  are  shown  at  d,  d,  d  ;  those  for  removing 
any  lint  which  may  attach  itself,  at  e,  e,  e.  They  are  kept  in  their  bearings  by  weighted 
levers  and  screws,  and  receive  a  slight  lateral  movement  to  and  fro,  by  means  of  the  ver- 
tical rod  m,  which  is  connected  at  top  to  an  eccentric,  on  the  end  of  the  axle  of  the  roller 
Kj  and  at  its  lower  end  to  a  horizontal  rod  mounted  at  the  side  of  the  frame  ;  lo  this  hori- 
zontal rod,  arms  are  attached,  which  are  connected  to  the  respective  doctors ;  and  thus, 
by  the  rotation  of  the  eccentric,  the  doctors  are  made  to  slide  laterally. 

When  the  cylinders  a,  b,  or  c,  are  employed  for  embossing  only,  those  doctors  will  not 
be  required.  The  driving  power  is  communicated  lo  the  machine  from  any  first  mover 
through  the  agency  of  the  toothed  gear,  which  gives  rotatorv  motion  to  the  cylinder  b, 
and  from  thence  to  the  other  cylinders  a,  and  c,  by  toothed  geer  shown  in  Fig.  485. 

EMBOSSING   OF   LEATHER.      Beautiful    ornaments  in   basso-relievo   for    deco- 
rating the  exteriors  or  interiors  of  buildings,  medallions,  picture-frames,  cabinet  work. 


638 


EMBROIDERING  MACHINE. 


EMBROIDERING  MACHINE. 


639 


liiii  i' 


It 


I'     t: 


<tc.,  have  been  recently  made  by  the  pressure  of  metallic  blocks  and  dies,  for  which 
invention  a  patent  was  obtained  in  June,  1 839,  V)y  M.  Claude  Schroth.  The  dies  are  made 
of  type  metal,  or  of  the  fusible  alloy  with  bismuth,  called  d'Arcet's.  The  leather  is 
beaten  soft  in  water,  then  wrung,  pressed,  rolled,  and  fulled  as  it  were,  by  working 
it  with  the  hands  till  it  becomes  thicker  and  quite  supple.  In  this  state  it  is  laid  on 
the  mould,  and  forced  into  all  its  cavities  by  means  of  a  wooden  bone,  or  copper  tool. 
In  other  cases,  the  embossing  is  performed  by  the  force  of  a  presa  The  leather,  when 
it  has  become  dry,  is  easily  taken  off  the  mould,  however  deeply  it  may  be  inserted 
into  its  crevices,  by  virtue  of  its  elasticity.  A  full  detail  of  all  the  processes  is  given 
in  IfevotorCs  Journal^  vol.  xxii.  p.  122. 

EMBOSSING  WOOD.  {Bossage,  Fr.;  Erhahene^,  Arbeit,  Germ.)  Raised  figures 
upon  wood,  such  as  are  employed  in  picture-frames  and  other  articles  of  ornamental 
cabinet  work,  are  usually  produced  by  means  of  carving,  or  by  casting  the  pattern  in 
plaster  of  Paris,  or  other  composition,  and  cementing,  or  otherwise  fixing  it  on  the 
surface  of  the  wood.  The  former  mode  is  expensive;  the  latter  is  inapplicable  on 
many  occasions.  The  invention  of  Mr.  Streaker  may  be  used  either  by  itself,  or  in  aid 
of  carving ;  and  depends  on  the  fact,  that  if  a  depression  be  made  by  a  blunt  instrument 
on  the  surface  of  the  wood,  such  depressed  part  will  again  rise  to  its  original  level  by 
subsequent  immersion  in  the  water. 

The  wood  to  be  ornamented  having  been  first  worked  out  to  its  proposed  shape,  is  in 
a  state  to  receive  the  drawing  of  the  pattern ;  this  being  put  on,  a  blunt  steel  tool,  or 
burnisher,  or  die,  is  to  be  applied  successively  to  all  those  parts  of  the  pattern  intended 
to  be  in  relief,  and,  at  the  same  time,  is  to  be  driven  very  cautiously,  without  breaking 
the  grain  of  the  wood,  till  the  depth  of  the  depression  is  equal  to  the  intended  prom- 
inence of  the  figures.  The  ground  is  then  to  be  reduced  by  planing  or  filing  to  the 
level  of  the  depressed  part ;  after  which,  the  piece  of  wood  being  placed  in  water,  either 
hot  or  cold,  the  part  previously  depressed  will  rise  to  its  former  height,  and  will  then 
form  an  embossed  pattern,  which  may  be  finished  by  the  usual  operations  of  carving. 

For  this  invention  the  Society  of  Arts  voted  to  Mr.  Streaker  their  silver  Isis  rtiedal 
and  ten  guineas. 

EMBROIDERIXG  MACHINE^  {Machine  a  hroder,  Fr. ;  Steckmasehine,  Germ.) 
This  art  has  been  till  of  late  merely  a  handicraft  employment,  cultivated  on  account  of  its 
elegance  by  ladies  of  rank.  But  a  few  years  agoM.  Heilmann,  of  Mulhause,  invented  a  ma- 
chine of  a  most  ingenious  kind,  which  enables  a  female  to  embroider  any  design  with  80 
or  100  needles  as  accurately  and  expeditiously  as  she  formerly  could  do  with  one.  A  brief 
account  of  this  remarkable  invention  will  therefore  be  acceptable  to  many  readers.  It 
was  displayed  at  the  national  exposition  of  the  products  of  industry  in  Paris  for  1834,  and 
was  unquestionably  the  object  which  stood  highest  in  public  esteem ;  for  whether  al  rest 
or  in  motion,  it  was  always  surrounded  with  a  crowd  of  curious  visiters,  admiring  the 
figures  which  it  had  formed,  or  inspecting  its  movements  and  investigating  its  mechanism. 
130  needles  were  occupied  in  copying  the  same  pattern  with  perfect  regularity,  all  set  in 
motion  by  one  person. 

Several  of  these  machines  are  now  mounted  in  France,  Germany,  and  Switzerland. 
I  have  seen  one  factory  in  Manchester,  where  a  great  many  of  them  are  doing  beautiful 
work. 

The  price  of  a  machine  having  130  needles,  and  of  consequence  260  pincers  or  fingers 
and  thumbs  to  lay  hold  of  them,  is  5000  francs,  or  200/.  sterling ;  and  it  is  estimated  to 
do  daily  the  work  of  15  expert  hand  embroiderers,  employed  u[»on  the  ordinary  frame.  It 
requires  merely  the  labor  of  one  grown-up  person,  and  two  assistant  children.  The 
operative  must  be  well  taught  to  use  the  machine,  for  he  has  many  things  to  attend  to; 
with  the  one  hand  he  traces  out,  or  rather  follows  the  design  with  the  point  of  the  pan- 
tograph ;  with  the  other  he  turns  a  handle  to  plant  and  pull  all  the  needles,  which  are 
seized  by  pincers  and  moved  along  by  carriages,  approaching  to  and  receding  from  the 
web,  rolling  all  the  time  along  an  iron  railway ;  lastly,  by  means  of  two  pedals,  upon 
which  he  presses  ahernately  with  the  one  foot  and  the  other,  he  opens  tlie  130  pincers 
of  the  first  carriage,  which  ought  to  give  up  the  needles  after  planting  them  in  the  stuff, 
and  he  shuts  with  the  same  pressure  the  130  pincers  of  the  second  carriage,  which  is  to 
receive  the  needles,  to  draw  them  from  the  other  side,  and  to  bring  them  back  aeain. 
The  children  have  nothing  else  to  do  than  to  change  the  needles  when  all  their  threads 
•re  used,  and  to  see  that  no  needle  misses  its  pincers. 

This  machine  deserves  particular  attention,  because  it  is  no  less  remarkable  for  the 
happy  arrangement  of  its  parts,  than  for  the  effects  which  it  produces.  It  may  be  descri- 
bed under  four  heads:  1.  the  structure  of  the  frame  ;  2.  the  disposition  of  the  web;  3.  the 
arransement  of  the  carriages;  and  4.  the  construction  of  the  pincers. 

1.  The  structure  of  the  frame.  It  is  composed  of  cast-iron,  and  is  very  massive. 
Fig.  487  exhibits  a  front  elevation  of  it.  The  length  of  the  machine  depends 
upon  the  number  of  pincers  to  be  worked.      The  model  at  the  exposition  had  260 


pincers,  and  was  2  metres  and  a  half  (about  100  inches  or  8  feet  4  inches  English) 
long.  The  figure  here  given  has  been  shortened  considerably,  but  the  other  propor- 
tions are  not  disturbed.  The  breadth  of  the  frame  ought  to  be  the  same  for  every 
machine,  whether  it  be  long  or  short,  for  it  is  the  breadth  which  determines  the  length  of 
the  thread  to  be  put  into  the  needles,  and  there  is  an  advantage  in  giving  it  the  full 
breadth  of  the  model  machine,  fully  100  inches,  so  that  the  needles  may  carry  a  thread 
at  least  40  inches  long. 

Biaposition  of  the  piece  to  be  embroidered. — ^We  have  already  stated  that  the  pincers 
which  hold  the  needles  always  present  themselves  opposite  to  the  same  point,  and  that 
in  consequence  they  would  continually  pass  backward  and  forward  flirough  the  same 
hole,  if  the  piece  was  not  displaced  with  sufficient  precision  to  bring  successively  opposite 
the  tips  of  the  needles  every  point  upon  which  they  are  to  work  a  design,  such  as  a  flower. 

The  piece  is  strained  perpendicularly  upon  a  large  rectangular  frame,  whose  four 
Bides  are  visible  in/<7,  487  ;  namely,  the  two  vertical  sides  at  f  f,  and  the  two  horizontal 
sides,  the  upper  and  lower  at  f'  f".     We  see  also  in  the  figures  two  long  wooden  rollers 


o  and  6,  whose  ends,  mounted  with  iron  studs,  are  supported  upon  the  sides  f  of  the 
frame,  so  as  to  turn  freely,  These  form  a  system  of  beams  upon  which  the  piece  des- 
tined to  receive  the  embroidery,  is  wound  and  kept  vertically  stretched  to  a  proper  de- 

41 


iiio^ 


I{ll' 


t  > 

V 


640 


EMBROIDERING  MACHINE. 


gree,  for  each  of  these  beams  bears  upon  its  end  a  small  ratchet  wheel  ff,  g  ;  the  teeth 
of  one  of  them  being  inclined  in  the  opposite  direction  to  those  of  the  other.  Besides 
this  system  of  lower  beams,  there  is  another  of  two  upper  beams,  which  is  however  but 
imperfectly  seen  in  the  figure,  on  account  of  the  interference  of  other  parts  in  this  view 
of  the  %naehine.  One  of  these  systems  presents  the  web  to  the  inferior  needles,  and 
the  other  to  the  upper  needles.  As  the  two  beams  are  not  in  the  aame  vertical  plane, 
the  plane  of  the  web  would  be  presented  obliquely  to  the  needles  were  it  not  for  a 
straight  bar  of  iron,  round  whose  edge  the  cloth  passes,  and  which  renders  it 
vertical.  The  piece  is  kept  in  tension  crosswise  by  small  brass  templets,  to  which  the 
strings  g"  are  attached,  and  by  which  it  is  pulled  toward  the  sides  of  the  frame  f.  It 
remains  to  show  by  what  ingenious  means  this  frame  may  be  shifted  in  every  possible 
direction.  M.  Ileilmann  has  employed  for  this  purpose  the  pantograph  which  draughts- 
men  use  for  reducing  or  enlarging  their  plans  in  determinate  proportions. 
.  .*  *'/'.  ^"  ^fiO-  487)  represents  a  parallelogram  of  which  the  four  angles  b,  b\  f,  b"  are 
jointed  in  sucii  a  way  that  they  may  become  very  acute  or  very  obtuse  at  pleasure, 
while  the  sides  of  course  continue  of  the  same  length ;  the  sides  b  b'  and  b  b"  are  pro- 
longed, the  one  to  the  point  d,  and  the  other  to  the  point  c,  and  these  points  c  and  d 
are  chosen  under  the  condition  that  in  one  of  the  positions  of  the  parallelogram,  the 
line  c  c?  which  joins  them  passes  through  the  point/;  this  condition  may  be  fulfilled  in 
an  infinite  number  of  manners,  since  the  position  of  the  parallelogram  remaining  the 
same,  we  see  that  if  we  wished  to  shift  the  point  d  further  from  the  point  b\  it  would 
be  sufficient  to  bring  the  point  c  near  enough  to  b",  or  vice  versa ;  but  when  we 
have  once  fixed  upon  the  distance  b'  d,  it  is  evident  that  the  distance  6"  c  is  its  necessary 
consequence.  Now  the  principle  upon  which  the  construction  of  the  pantograph  rests 
is  this;  it  is  sufficient  that  the  three  points  d,/,  and  c  be  in  a  straight  line,  in  one  only 
of  the  positions  of  the  parallelogram,  in  order  that  they  shall  remain  always  in  a 
straight  line  in  every  position  which  can  possibly  be  given  to  it 

We  see  in  the  figure  that  the  side  b  c  has  a  handle  b"  with  which  the  workman  puts 

the  machine  in  action.     To  obtain  more  precision  and  solidity  in  work,  the  sides  of  the 

pantograph  are  joined,  so  that  the  middle  of  their  thickness  lies  exactly  in  the  vertical 

plane  of  the  piece  of  goods,  and  that  the  axes  of  the  joints  are  truly  perpendicular  to 

this  plane,  in  which  consequently  all  the  displacements  are  effected.     We  arrive  at 

this  result  by  making  fast  to  the  superior  great  cross  bar  d"  an  elbow  piece  d'\  having  a 

suitable  projection,  and  to  which  is  adapted  in  its  turn  the  piece  d\  which  receives  in  a 

locket  the  extremity  of  the  side  b,  a  ;    this  piece  d'  is  made  fast  to  d"  by  a  bolt,  but  it 

carries  an  oblong  hole,  anJ  before  screwing  up  the  nut,  we  make  the  piece  advance  or 

recede,  till  the  fulcrum  point  comes  exactly  into  the  plane  of  the  web.    This  condition  being 

fulfilled,  we  have  merely  to  attach  the  frame  to  the  angle  /of  the  parallelogram,  which  is 

done  by  means  of  the  piece  f". 

It  is  now  obvious  that  if  the  embroiderer  takes  the  handle  b"  in  his  hand  and  makes 
the  pantograph  move  in  any  direction  whatever,  the  point  /  will  describe  a  figure  simi- 
lar to  the  figure  described  by  the  point  c,  and  six  times  smaller,  but  the  point  /  cannot 
move  without  the  frame,  and  whatever  is  upon  it  moving  also.  Thus,  in  the  movement 
of  the  pantograph,  every  point  of  the  web  describes  a  figure  equal  to  that  described  by 
the  point  /,  and  consequently  similar  to  that  described  by  the  point  c,  but  six  times 
smaller;  the  embroidered  object  being  produced  upon  the  cloth  in  the  position  of  that 
of  the  pattern.  It  is  sufficient  therefore  to  give  the  embroidering  operative  who  holds 
the  handle  b",  a  design  six  times  greater  than  that  to  be  executed  by  the  machine,  and  to 
afford  him  at  the  same  time  a  sure  and  easy  means  of  tracing  over  with  the  point  c,  all  the 
outlines  of  the  pattern.  For  this  purpose  he  adapts  to  c,  perpendicularly  to  the  plane 
of  the  parallelogram,  a  small  style  terminated  by  a  point  c',  and  he  fixes  the  pattern 
upon  a  vertical  tablet  e,  parallel  to  the  plane  of  the  stufi*  and  the  parallelogram,  and 
distant  from  it  only  by  the  length  of  the  style  c  c" ;  this  tablet  is  carried  by  the  iron 
rod  e\  which  is  secured  to  a  cast  iron  fool  e',  serving  also  for  other  purposes,  as  we  shall 
presently  see.  The  frame  loaded  with  its  beams  and  its  cloth  forms  a  pretty  heavy 
mass,  and  as  it  must  not  swerve  from  its  plane,  it  needs  to  be  lightened  in  order  that  the 
operative  may  cause  the  point  of  the  pantograph  to  pass  along  the  tablet  without  strain- 
ing or  uncertainty  in  its  movements.  M.  Heilmann  has  accomplished  these  objects  in  the 
following  way.  A  cord  c  attached  to  the  side  6  c  of  the  pantograph  passes  over  a  return 
pulley,  and  carries  at  its  extremity,  a  weight  which  may  be  graduated  at  pleasure ;  this 
weight  equipoises  the  pantograph,  and  tends  slightly  to  raise  the  frame.  The  lower 
side  of  the  frame  carries  two  rods  h  and  h,  each  attached  by  two  arms  h  hy  a.  little  bent 
to  the  left;  both  of  these  are  engaged  in  the  grooves  of  a  pulley.  Through  this  mecha- 
nism a  pressure  can  be  exercised  upon  the  frame  from  below  upwards,  which  may  be 
regulated  at  pleasure,  and  without  preventing  the  frame  from  moving  in  all  directions, 
it  hinders  it  from  deviating  from  the  primitive  plane  to  which  the  pantograph  was  adjust- 
ed.    The  length  of  the  rods  h  ought  to  be  equal  to  the  amount  of  the  lateral  movement 


EMBROIDERING  MACHINE. 


641 


of  the  frame.     Two  guides  t  t  carried  by  two  legs  of  cast  iron,  present  vertical  elite  in 

which  the  lower  part  of  the  frame  f'  is  engaged. 

Disposition  of  tJu  carriages.— The  two  carriages,  which  are  similar,  are  placed  the  one 
to  the  right,  and  the  other  to  the  left  of  the  frame.  The  carriage  itself  is  composed 
merely  of  a  long  hollow  cylinder  of  cast  iron  l,  carrying  at  either  end  a  system  of  two 
grooved  castors  or  pulleys  l',  which  roll  upon  the  horizontal  rails  k  ;  the  pulleys  are  mount- 
ed upon  a  forked  piece  I',  with  two  ends  to  receive  the  axes  of  the  pulleys,  and  the  piece 
r  is  itself  bolted  to  a  projecting  ear  Zcast  upon  the  cylinder. 

This  assemblage  constitutes  properly  speaking  the  carriage,  resting  in  a  perfectly 
stable  equilibrium  upon  the  rails  k,  upon  which  it  may  be  most  easily  moved  backwards 
and  forwards,  carrying  its  train  of  needles  to  be  passed  or  drawn  through  the  cloth. 

M.  Heilmann  has  contrived  a  mechanism  by  which  the  operative  without  budging 
from  his  place  may  conduct  the  carriages,  and  regulate  as  he  pleases  the  extent  of  their 
course,  as  well  as  the  rapidity  of  their  movements.  By  turning  the  axes  m"  in  the  one 
direction  or  the  other,  the  carriage  may  be  made  to  approach  to,  or  recede  from  the 
web. 

When  one  of  the  carriages  has  advanced  to  prick  the  needles  into  the  stuff,  the  other 
is  there  to  receive  them;  it  lays  hold  of  them  with  its  pincers,  pulls  them  through 
performs  its  course  by  withdrawing  to  stretch  the  thread,  and  close  the  stitch  then  it 
goes  back  with  the  needles  to  make  its  pricks  in  return.  During  these  movements  the 
first  carriage  remains  at  its  post  waiting  the  return  of  the  second.  Thus  the  two  chariots 
make  in  succession  an  advance  and  a  return,  but  they  never  move  together. 

To  effect  these  movements  M.  Heilmann  has  attached  to  the  piece  o'  made  fast  to 
the  two  uprights  a  c  and  a  d  of  the  frame,  a  bent  lever  n  o  n'  n"  moveable  round  the 
point  o ;  the  bend  n'  carries  a  toothed  wheel  o',  and  the  extremity  n"  a  toothed  wheel 
o  ;  the  four  wheels  m  m'  o'  and  o"  have  the  same  number  of  teeth  and  the  same 
diJimeter;  the  two  wheels  o' and  o"  are  fixed  in  reference  to  each  other,  so  that  it  is 
sufficient  to  turn  the  handle  n  to  make  the  wheel  o"  revolve,  and  consequently  the 
wheel  o' ;  when  the  lever  n  o  is  vertical,  the  wheel  o'  touches  neither  the  wheel  m  nor  the 
wheel  M';  but  if  it  be  inclined  to  the  one  side  or  the  other,  it  brings  the  wheel  o'  alter- 
nately  into  gear  with  the  wheel  m  or  the  wheel  m'.  As  the  operative  has  his  two  hands 
occupied,  the  one  with  the  pantograph  and  the  other  with  the  handle  of  impulsion,  he 
has  merely  his  leet  for  acting  upon  the  levern  o,  and  as  he  has  many  other  things  to 

•.u  :•    r  ^^^  adapted  before  him  a  system  of  two  pedals,  by  which  he  executes 

with  his  leet  a  series  of  operations  no  less  delicate  than  those  which  he  executes  with  his 
bands. 

The  pedals  p  are  moveable  round  the  axis  p,  and  carry  cords  p'  wound  in  an  opposite 
direction  upon  the  pulleys  p' ;  these  pulleys  are  fixed  upon  a  moveable  shaft  p",  sun- 
ported  upon  one  side  by  the  prop  e',  and  on  the  other  in  a  piece  k'  attached  to  the  two 
great  uprights  of  the  frame.  In  depressing  the  pedal  p  (now  raised  in  the  figure),  the 
upper  part  of  the  shaft  p'  will  turn  from  the  left  to  the  right,  and  the  lever  n  o  will  be- 
come inchned  so  as  to  carry  the  wheel  o'  upon  the  wheel  m',  but  at  the  same  time  the 
pedal  which  is  now  depressed  will  be  raised,  because  its  cord  will  be  forced  to  wind  itself 
upon  Its  pulley,  as  much  as  the  other  cord  has  unwound  itself;  and  thus  the  apparatus 
will  be  ready  to  act  in  the  opposite  direction,  when  wanted. 

Disposition  of  the  pincers.— The  shaft  l'  carries,  at  regular  intervals  of  a  semi-diame- 
ter, the  appendages  q  q  cast  upon  it,  upon  which  are  fixed,  by  two  bolts,  the  curved 
branches  q  destined  to  bear  the  whole  mechanism  of  the  pincers.  When  the  pincers  are 
opened  by  their  appropriate  leverage,  and  the  half  of  the  needle,  which  is  pointed  at 
each  end,  with  the  eye  m  the  middle,  enters  the  opening  of  its  plate,  it  gets  lod«^ed  in  an 
angular  groove,  which  is  less  deep  than  the  needle  is  thick,  so  that  when  the  pincers  are 
c  osed,  the  upper  jaw  presses  it  into  the  groove.  In  this  way  the  needle  is  firmly  held 
alihough  touched  in  only  three  points  of  its  circumference.  * 

Suppose,  now,  that  all  the  pincers  are  mounted  and  adjusted  at  their  proper  distances 
upon  their  prismatic  bar,  forming  the  upper  range  of  the  right  carriage.  For  opening  ail 
the  pincers  there  is  a  long  plate  of  iron,  u,  capable  of  turning  upon  its  axis,  and  which 
extends  from  the  one  end  of  the  carriage  to  the  other.  This  axis  is  (trried  by  a  kind  of 
forks  which  are  bolted  to  the  extremity  of  the  branches  q.  By  turning  that  axis  the 
workman  can  open  the  pincers  at  pleasure,  and  they  are  again  closed  by  sprin<'s.  This 
movement  is  performed  by  his  feet  acting  upon  the  pedals. 

The  threads  get  stretched  in  proportion  as  the  carriage  is  run  out,  but  as  this  tension 
has  no  elastic  play,  inconveniences  might  ensue  which  are  prevented  by  adapting  to  the 
carriage  a  mechanism  by  means  of  which  all  the  threads  are  pressed  at  the  same  time  by 
a  weight  susceptible  of  graduation.  A  little  beneath  the  prismatic  bar,  wkich  carries 
the  pincers,  we  see  m  the  figure  a  shaft,  y,  going  from  one  end  of  the  carriage  to  the 
other,  and  even  a  hltle  beyond  it ;  this  shaft  is  carried  by  pieces  y  which  are  fixed  to  the 
arms  q,  and  in  which  it  can  turn.    At  its  left  end  it  carries  two  smaU  bars  y'  and  to',  and 


T 


I 


642 


EMERY. 


EMERY. 


'  f 


at  its  right  a  single  bar  y\  and  a  counterweight  (not  visible  in  this  view);  the  ends  of 
the  two  bars  y"  are  joined  bj  an  iron  wire  somewhat  stout  and  perfectly  straight.  When 
the  carriage  approaches  the  web,  and  before  the  iron  wire  can  touch  it,  the  little  bar  «• 
presses  against  a  pin,  u>',  which  rests  upon  it,  and  tends  to  raise  it  more  and  more.  In 
■what  has  preceded  we  have  kept  in  view  only  the  upper  range  of  pincers  and  needles, 
but  there  is  an  inferior  range  quite  similar,  as  the  figure  shows,  at  the  lower  ends  of  the 
arms  q.  In  conclusion,  it  should  be  stated,  that  the  operative  does  not  follow  slidingly 
with  the  pantograph  the  trace  of  the  design  which  is  upon  the  tablet  or  the  picture,  but 
he  must  stop  the  point  of  the  style  upon  the  point  of  the  pattern  into  which  the  needle 
should  enter,  then  remove  it,  and  put  it  down  again  upon  the  point  by  which  the  needle 
ought  to  re-enter  in  coming  from  the  other  side  of  the  piece,  and  so  on  in  succession.  To 
facilitate  this  kind  of  reading  off,  the  pattern  upon  the  tablet  is  composed  of  right  lines 
terminated  by  the  points  for  the  entrance  and  return  of  the  needle,  so  that  the  operative 
(usually  a  child)  has  continually  under  her  eyes  the  series  of  broken  lines  which  must 
be  followed  by  the  pantograph ;  if  she  happens  to  quit  this  path  an  instant,  without  hav- 
ing left  a  mark  of  the  point  at  which  she  had  arrived,  she  is  under  the  necessity  of  look- 
ing at  the  piece  to  see  what  has  been  already  embroidered,  and  to  find  by  this  comparison 
the  point  at  which  she  must  resume  her  work,  so  as  not  to  leave  a  Wank,  or  to  repeat 
the  same  stitch. 

Explanation  of  figure. 

A,  lower  cross  bars,  which  unite  the  legs  of  the  two  ends  of  the  frame. 

a,  the  six  feet  of  the  front  end  of  the  frame. 

a',  the  six  feet  of  the  posterior  end  of  the  frame. 

a",  curved  pieces  which  unite  the  cross  bars  a"  to  thi  uprights. 

b",  handle  of  the  pantograph. 

h  h'  h"y  three  of  the  angles  of  the  pantograph. 

c,  point  of  the  side  h  b"  on  which  the  point  is  fixed, 
c",  point  of  the  pantograph. 

d",  cross  bar  in  form  of  a  gutter,  which  unites  the  upper  parts  of  the  frame. 

d,  fixed  point,  round  which  the  pantograph  turns. 

E,  tablet  upon  which  the  pattern  to  be  embroidered  is  put. 
e",  support  of  that  tablet. 

e,  cord  attached  at  one  end  to  the  side  6  c  of  the  pantograph  passing  over  a  guide  p•^ 
ley^  and  carrying  a  weight  at  the  other  end. 

tf',  iron  rod  by  which  the  tablet  k  is  joined  to  its  support  i'. 

F,  F,  uprights  of  the  cloth-carrying  frame. 
f',  f',  horizontal  sides  of  the  same  frame, 
o,  four  roll  beams. 

g",  the  piece  of  cloth. 

</",  the  strings,  which  serve  to  stretch  the  cloth  laterally. 

EMERALD  {Emeraude,  Fr. ;  Smaragd,  Germ.),  is  a  precious  stone  of  a  beautiful 
green  color;  valued  next  to  diamond,  and  in  the  same  rank  as  oriental  ruby  and 
sapphire.  It  occurs  in  prisms  with  a  regular  hexagonal  base;  »\\  gi*av.  2-7;  scratches 
quartz  with  difficulty;  is  scratched  by  topaz;  fusible  at  the  blowpipe  into  a  frothy 
bead;  the  precipitate  afforded  by  ammonia,  from  its  solution,  is  soluble,  in  a  great 
measure,  in  carbonate  of  ammonia.  Its  analysis  is  given  very  variously  by  different 
chemists.  It  contains  about  14  per  cent  of  glucina,  which  is  its  characteristic  con- 
stituent; along  with  68  of  silica,  16  of  alumina,  a  very  little  lime  and  iron.  The  beau- 
tiful emerald  of  Peru  is  found  in  a  clay  schist  mixed  with  some  calcareous  matter.  A 
stone  of  4  grains  weight  is  said  to  be  worth  from  4/.  to  6/. ;  one  of  8  grains,  10/. ;  one 
of  15  grains,  being  line,  is  worth  60/;  one  of  24  grains  fetched,  at  the  sale  of  M.  de 
Drue's  cabinet,  2400  francs,  or  nearly  100/. 

The  beryl  is  analogous  in  composition  to  the  emerald,  and  is  employed  (when  of  the 
common  opaque  kind,  found  near  Limoges),  by  chemists,  for  procuring  the  earth 
glucina. 

EMERY.  This  mineral  was  long  regarded  as  an  ore  of  iron ;  and  was  called  by 
Haiiy /(?r  oxide  quartzifere.  It  is  very  abundant  in  the  island  of  Naxos,  at  cape  Emeri, 
whence  it  is  imported  in  large  quantities.  It  occurs  also  in  the  islands  of  Jersey  and 
Guftrnsey,  at  Almaden,  in  Poland,  Saxony,  Sweden,  Persia,  <kc.  Its  color  varies  from 
red  brown  to  dark  brown  ;  its  specific  gravity  is  about  4'000;  it  is  so  hard  as  to  scratch 
quartz  and  many  precious  stones.  By  Mr.  Teimnt's  analysis,  it  consists  of  alumina, 
80;  silica,  3;  iron,  4.  Another  inferior  kind  yielded  32  of  iron,  and  only  50  of 
alumina. 

We  have  recent  accounts  of  emery  discoveries  in  Minesota,  but  nearly  all  that  is  used 
at  present  in  the  arts  comes  from  Turkey,  near  ancient  Smyrna.  Dr.  Lawrence  Smith, 
the  American  geologist,  made  a  discoveiy  of  a  deposit  of  emery  while  residing  in 
Smyrna,  and  he  made  an  examination  of  the  locality  in  1847. 


643 


Dr.  Smith  having  reported  his  discoveries  to  the  Turkish  government,  a  commission 
of  inquiry  was  instituted,  and  the  business  soon  assumed  a  mercantile  form.  The  mo- 
nopoly of  the  emery  of  Turkey  was  sold  to  a  mercantile  house  in  Smyrna,  and  since 
then  the  price  has  diminished  in  the  market 

The  mining  of  the  emery  is  of  the  simplest  character.     The  natural  decomposition 
of  the  rock  m  which  it  occurs  facilitates  its  extraction.     The  rock  decomposes  into  an 
earth,  in  which  the  emery  is  found  imbedded.    The  quantity  procured  under  these  cir- 
cumstances IS  so  great  that  it  is  rarely  necessary  to  explore  the  rock.    The  earth  in  the 
neighborhood  of  the  block  is  almost  always  of  a  red  color,  and  serves  as  an  indication 
to  those  who  are  m  search  of  the  mineral.     Sometimes,  before  beginning  to  excavate 
the  spota  are  sounded  by  an  iron  rod  with  a  steel  point,  and  when  anv  resistance  is  met 
wiUi,  the  rod  IS  rubbed  in  contact  with  the  resisting  body,  and  the  effect  produced  on 
the  point  enables  a  practised  eye  to  decide  whether  it  has  been  done  by  emery  or  not 
Ihe  blocks  which  are  of  a  convenient  size  are  transported  in  their  natural  state,  but  are 
frequently  broken  by  large  hammers;  when  they  resist  the  action  of  the  hammer,  they 
are  subjec  ed  to  the  action  of  fire  for  several  hours,  and  on  cooling  they  most  commonly 
yield  to  blows.     It  sometimes  happens  that  large  masses  are  abandoned,  from  the  im- 
possibility of  breaking  them  into  pieces  of  a  convenient  size,  as  the  transportation,  either 
on  camels  or  horses,  requires  that  pieces  shall  not  exceed  100  lbs.  each  m  weight 
^ery  appears  to  be  a  mechanical  mixture  of  corundum  and  oxide  of  iron 
When  reduced  to  a  powder,  it  varies  in  color  from  dark  grey  to  black.     The  color 
of  Its  powder  affords  no  indication  of  its  commercial  value.     The  powder  examined 
under  the  microscope  shows  the  distinct  existence  of  two  minerals,  corundum  and  oxide 
oi  iron.     H^mery,  when  moistened,  always  affords  a  very  strong  argillaceous  odor      Its 
hardness  's  i^  most  important  property  in  its  application  to  the  arts,  and  was  ascer- 
tained by  Mr.  Smith  in  the  following  manner  .-—Fragments  were  broken  from  the  piece 
to  be  examined,  and  crushed  m  a  diamond  mortar  with  two  or  three  blows  of  a  hammer 
then  thrown  into  a  sieve  with  400  holes  to  the  inch.    The  powder  is  then  weighed,  and 
the  hardness  tested  with  a  circular  piece  of  glass,  about  four  inches  in  diameter,  and  a 
small  agate  mortar.     The  glass  is  first  weighed,  and  placed  on  a  piece  of  glazed  paper  • 
"  •t.^ri'^T?.    ^™f  yj«  then  thrown  upon  it  at  intervals,  rubbing  it  against  the  glas^ 
witli  the  bottom  of  the  agate  mortar.     The  emery  is  brushed  off  the  glass  from  tinTe  t^ 
time  with  a  feather  and  when  all  the  emery  has  been  made  to  pass  once  over  the  glass 
It  was  collected,  and  passed  through  the  same  operation  three  or  four  times.     The  glass 
was  then  weighed,  again  subjected  to  the  same  operation,  the  emery  by  this  time  being 
rnlvlin  i*l  an  impalpable  powder.     This  series  of  operations  is  continued  until  the  los! 
Z  wlln  ^1    If  ^    ""  •''  ^^^n^'^gly  ^"'••^H-     The  total  loss  in  the  glass  is  then  noted, 
and  when  all  the  specimens  of  emery  are  submitted  to  this  operation  under  the  same 
circumstances,  an  exact  idea  of  their  relative  hardness  is  obtained.     The  advantages  of 
using  glass  and  agate  are,  that  the  latter  is  sufficiently  hard  to  crush  the  emery,  and  in 
a  certain  space  of  time  to  reduce  it  to  such  an  impalpable  state,  that  it  has  no  longer  any 
sensible  effect  on  the  glass;  and,  on  the  other  hand,  the  glass  is  soft  enough  to  lose 
during  this  time  sufficient  of  its  substance  to  allow  of  accurate  comparative  results. 
By  this  method,  the  best  emery  was  found  capable  of  wearing  away  ibout  half  of  its 
weight  of  common  French  window-glass.     The  blue  sapphire  of  Ceylon,  pulverized  and 
experimented  with  in  this  manner,  wears  away  more  than  four-fifths  of  its  weight 
This  furnished  the  standord  of  comparison.  weiguu 

In  the  ordinary  process,  the  lumps  of  emery  ore  are  broken  up  in  the  same  manner  as 
stone  IS  for  repairing  Macadamised  roads,  and  into  lumps  of  similar  size.  These  lumps 
then  crushed  under  stampers,  such  as  are  used  for  pounding  metallic  ores,  driven  by 

rnlf[  ''\\^  1?'"'"  P'^TT',    I.V.l'"PP^'^^  ^^^^  t'^«  stampers  leave  the  fragments  more 
angular  than  they  would  be  if  they  were  ground  under  runners,  a  mode  which  is  some- 
times employed.     The  coarse  powder  is  then  sifted  through  sieves  of  wire  cloth,  which 
are  generally  cylmdncal  like  the  bolting  cylinders  of  corn-mills;  but  the  sieves  are 
covered  with  wire  cloth,  haying  ,n  general  about  ninety  to  sixteen  wires  to  the  inch. 
No  10  sieve  gives  emery  of  about  the  size  of  mustard-seed;  and  coarser  fragments,  ex- 
tending nearlv  to  the  size  of  pepper-corns,  are  also  occasionally  prepared  for  the  use  of 
engineers.     The  sieves  have  sometimes  as  many  as  120  wires  to  the  inch ;  but  the  very 
fine  sizes  of  emei-y  are  more  commonly  sifted  through  lawn  sieves.     The  finest  emery 
that  IS  obtained  from  the  manufacturers  is  that  which  floats  in  the  atmosphere  of  thi 
stamping-room,  and  ,s  deposited  on  the  beams  and  shelves,  from  which  it  is  occasionally 
collected.     The  manufacturers  rarely  or  never  wash  the  emery ;  this  is  mostly  done  by 
obLineTbv'siftin  ^  "'  '^"^"'"^  *  ^^^""^^"^  ^^^^^^  of  precision  than  can  bi 

Washing"  emery  by  hand  is  far  too  tedious  for  those  who  require  very  large  quantities 
of  emery,  such  as  the  manufacturers  of  plate-glass  and  some  others  who  generally  adopt 
the  following  method  .--Twelve  or  more  cylinders  of  sheet  copper,  of  the  common 


A 


644 


EMERY. 


height  of  about  two  feet,  and  varying  from  about  three,  five,  eight,  to  thirty  or  forty 
inches  in  diameter,  are  placed  exactly  level,  and  communicating  at  their  upper  edges, 
each  to  the  next,  by  small  troughs  or  channels;  the  largest  vessel  has  also  a  waste-pipe 
near  the  top.  At  the  commencement  of  the  process,  the  cylinders  are  all  filled  to  the 
brim  with  clean  water;  the  pulverised  emery  is  then  churned  up  with  abundance  of 
water  in  another  vessel,  and  allowed  to  run  into  the  smallest  or  three-inch  cylinder, 
through  a  tube  opposite  the  gutter  leading  to  the  second  cylinder.  The  water  during 
its  short  passage  across  the  three-inch-  cylinder,  deposits  in  that  vessel  such  of  the 
coarsest  emery  as  will  not  bear  suspension  for  that  limited  time ;  the  particles  next  finer 
are  deposited  in  the  five-inch  cylinder,  during  the  somewhat  longer  time  the  mixed 
steam  takes  in  passing  the  brim  of  that  vessel ;  and  so  on.  Eventually  the  water  forms 
a  very  languid  eddy  in  the  largest  cylinder,  and  deposits  therein  the  very  fine  particles 
that  have  remained  in  suspension  until  this  period ;  and  the  water,  lastly,  escapes  by 
the  waste-pipe  nearly  or  entirely  free  from  emery.  In  this  simple  arrangement,  time 
IS  also  the  measure  of  the  particles  respectively  deposited  in  the  manufacture  to  which 
the  emery  is  applied.  When  the  vessels  are  to  a  certain  degree  filled  with  emery,  the 
process  is  stopped,  the  vessels  are  emptied,  the  emery  is  carefully  dried  and  laid  by 
and  the  process  is  recommenced.  * 

Emery  paper  is  prepared  by  brushing  the  paper  over  with  thin  glue,  and  dusting  the 
enoery-powder  over  it  from  a  sieve.  There  are  about  six  degrees  of  coarseness.  Sieves 
with  thirty  3nd  ninety  meshes  per  linear  inch,  are  in  general  the  coarsest  and  finest 
81^8  employed.  When  used  by  artizans,  the  emery-paper  is  commonly  wrapped  around 
a  file  or  a  shp  of  wood,  and  applied  just  like  a  file,  with  or  without  oil,  according  to 
circumstances.    The  emery-paper  cuts  more  smoothly  with  oil,  but  leaves  the  work  dull. 

Emery  cloth  only  differs  from  emery-paper  in  the  use  of  thin  cotton  cloth  instead  of 
paper,  as  the  material  upon  which  the  emery  is  fixed  by  means  of  glue.  The  emery 
cloth,  when  folded  around  a  file,  does  not  ply  so  readily  to  it  as  emery-paper,  and  is  apt 
to  unroll  Hence  smiths,  engineers,  and  others,  prefer  emery-paper  and  emery -sticks ; 
but  for  household  and  other  purposes,  where  the  hand  alone  is  used,  the  greater  dura- 
bility of  the  cloth  is  advantageous 

Enriery-sticks  are  rods  of  board  about  eight  or  twelve  inches  lonir,  planed  up  square ; 
or  with  one  side  rounded  like  a  half-round  file.  Nails  are  driven  into  each  end  of  the 
stick  as  temporary  handles ;  they  are  then  brushed  over  one  at  a  time  with  thin  glue,  and 
dabbed  at  all  parts  in  a  heap  of  emery-powder,  and  knocked  on  one  end  to  shake  off  the 
excess.  Two  coats  of  glue  and  emery  are  generally  used.  The  emery-sticks  are  much 
more  economical  than  emery-paper  wrapped  on  a  file,  which  is  liable  to  be  torn. 

Emerjr-cake  consists  of  emery  mixed  with  a  little  beeswax,  so  as  to  constitute  a  solid 
lump,  with  which  to  dress  the  edges  of  buff  and  glaze  wheels.  The  ingredients  should 
be  thoroughly  incorporated  by  stirring  the  mixture  whilst  fluid,  after  which  it  is  fre- 
quently poured  into  water,  and  thoroughly  kneaded  with  the  hands,  and  rolled  into 
lumps  before  it  has  time  to  cool.  The  emery-cake  is  sometimes  applied  to  the  wheels 
whilst  they  are  revolving;  but  the  more  usual  course  is,  to  stop  the  wheel,  and  rub  in 
the  emery-cake  by  hand.     It  is  afterwards  smoothed  down  by  the  thumb. 

Emery-paper,  or  patent  razor-strop  paper,  an  article  in  which  fine  emery  and  glass 
are  mixed  with  paper  pulp,  and  made  into  sheets  as  in  making  ordinary  paper;  the 
emery  and  glass  are  said  to  constitute  together  60  per  cent  of  the  weight  of  the  paper, 
which  resembles  drawing-paper,  except  that  it  has  a  delicate  fawn  color.  The  emeryl 
paper  is  directed  to  be  pasted  or  glued  upon  a  piece  of  wood,  and  when  rubbed  with  a 
little  oil,  to  be  used  as  a  razor-strop. 

In  1842,  Mr.  Henry  Barclay  took  out  a  patent  for  a  method  of  combining 
powdered  emery  into  discs  and  laps  of  different  kinds,  suitable  to  grinding,  cutting, 
and  polishing  glass,  enamels,  metals,  and  other  hard  substances.  The  process  of 
manufacture  is  as  follows: — Coarse  emery-powder  is  mixed  with  about  half  its 
weight  of  pulverized  Stourbridge  loam  and  a  little  water  or  other  liquid,  to  make  a 
thick  paste ;  this  is  pressed  into  a  metallic  mould  by  means  of  a  screw-press,  and  after 
having  been  thoroughly  dried,  is  baked  or  burned  in  a  muffle  or  close  receiver  at  a 
temperature  considerably  above  a  red  heat,  and  below  the  full  white  heat  In  this  case, 
the  clay  or  elumma  serves  as  a  bond,  and  unites  the  particles  very  completely  into  a 
solid  artificial  emery-stone,  which  cuts  very  greedily,  and  yet  seems  hardly  to  suffer 
perceptible  wear. 

Superfine  grinding  emery  is  formed  into  wheels  exactly  in  the  same  manner  as  the 
above,  but  the  proportion  of  loam  is  then  only  one-fourth  instead  of  one-half  that  of  the 
emery.  Those  emery  stones,  which  are  of  medium  fineness,  cut  less  quickly,  but  more 
smoothly  than  the  above. 

Flour-emery,  when  manufactured  into  artificial  stones,  requires  no  uniting  substance, 
but  the  moistened  powder  is  forced  into  the  metal  mould  and  fired  ;  some  portions  of 
the  alumina  being  sufficient  to  unite  the  whole.    These  fine  wheels  render  the  works 


ENAMELS. 


645 


submitted  to  them  exceedingly  smooth,  but  they  do  not  produce  a  high  polish  on  account 
of  the  comparative  coarseness  of  the  flour-emery. 

^  The  alumina  of  emery  is  believed  to  be  aggregated  to  the  same  degree  of  hardness  as 
in  corundum  or  adamantine  spar ;  which  is  one  of  the  hardest  minerals  known.  Emery 
18  extensively  employed  for  grinding  metals,  glass,  Ac. ;  for  which  purpose  it  is  reduced 
to  powders  of  different  degrees  of  fineness  by  grinding  and  elutriation. 

2,000  tons  per  annum  at  from  60  to  70  dollars  each,  according  to  quality,  are  con- 
sumed  m  the  United  Kingdom.  ^        "^ 

EMPYREUMA,  means  the  offensive  smell  produced  by  fire  applied  to  organic 
?*"*•■?,». ^^'^^^y  v«?«^*»^«»  i*^  c^ose  vessels.  Thus,  empyreumatic  vinegar  is  obtained 
by  distilling  wood  at  a  red  heat,  and  empyreumatic  oU  from  many  animal  substances  in 
the  same  way. 

ENAMELS  (Emaux,  Fr. ;  Sckmelzglas,  Germ.)  are  varieties  of  glass,  generally  opaque 
and  colored,  always  formed  by  the  combination  of  different  metallic  oxydes,  to  wSch 
certain  fixed  fusible  salts  are  added,  such  as  the  borates,  fluates,  and  phosphates. 

The  simplest  enamel,  and  the  one  which  serves  as  a  basis  to  most  of  the  others,  is 
obtained  by  calcining  first  of  all  a  mixture  of  lead  and  tin,  in  proportions  varying  from 
15  to  50  parts  of  tin  for  100  of  lead.     The  middle  term  appears  to  be  the  most  suitable 
for  the  greater  number  of  enamels;  and  this  alloy  has  such  an  affinity  for  oxygen,  that 
It  may  be  calcined  with  the  greatest  ease  in  a  flat  cast-iron  pot,  and  at  a  temperatui^  not 
above  a  cherry  red  provided  the  dose  of  tin  is  not  too  great.    The  oxyde  is  drawn  off  to 
the  sides  of  the  melted  metal  according  as  it  is  generated,  new  pieces  of  the  alloy  being 
thrown  in  from  time  to  time,  till  enough  of  the  powder  be  obtained.     Great  care  ought 
to  be  taken  that  no  metallic  particles  be  left  in  the  oxyde,  and  that  the  calcining  heat  be 
as  low  as  is  barely  sufficient ;  for  a  strong  fire  frits  the  powder,  and  obstructs  its  subse- 
,nent  comminution.    The  powder  when  cold  is  ground  in  a  proper  mill,  levigated  with 
water,  and  elutriated,  as  wUl  be  described  under  Red  lead.     In  this  state  of  fineness  and 
parity,  it  is  called  calcine,  or  flux,  and  it  is  mixed  with  silicious  sand  and  some  alkaline 
matter  or  sea-salt.     The  most  ordinary  proportions  are,  4  of  sand,  1  of  sea-salt,  and  4  ol 
calcine.     Chaptal  states  that  he  has  obtained  a  very  fine  product  from  100  parts  of  cal- 
cine, made  by  calcining  equal  parts  of  lead  and  tin,  100  parts  of  ground  flint,  and  200 
parts  of  pure  subcarbonate  of  potash.     In  either  case,  the  mixture  is  put  into  a  crucible, 
or  laid  simply  on  a  stratum  of  sand,  quicklime  spontaneously  slaked,  or  wood-ashes! 
placed  under  a  pottery  or  porcelain  kiln.    This  mass  undergoes  a  semi-vitrification;  or 
even  a  complete  fusion  on  its  surface.    It  is  this  kind  of  frit  which  serves  as  a  radical 
to  almost  every  enamel ;  and  by  varying  the  proportions  of  the  ingredient,  more  fusible, 
more  opaque,  or  whiter  enamels  are  obuined.     The  first  of  these  qualities  depends  on 
the  quantity  of  sand  or  flux,  and  the  other  two  on  that  of  the  tin 

The  sea-salt  employed  as  a  flux  may  be  replaced  either  by  salt  of  tartar,  by  pxut 
^i    '.*"*■  .Z  ^''l  ^^'  ^^"^^  ^^  ^^^^^  ^"^^  Si^^^  peculiar  qualities  to  the  enamel. 
rt,J^^J'J?ti*''r  ^**°,^*^«  ^""^»  ?«  the  preparation  of  enamels,  insist  a  great  deal  oa 
itn  o^^fh.  Lf     r^i""^  '"^'^"^^  '^'  particular  sand  that  should  inter  into  the  comp^ 

Ip^^f  1  nJr  «r  ?  ?  ^r  T%    r^^  *^'*"''''*  ^  ^^'""^^  t^^t  t^e  sa"d  ought  to  contain  a 
least  1  part  of  talc  for  3  of  silicious  matter,  otherwise  the  enamel  obtained  is  never  verv 
glassy,  and  that  some  wrinkled  spots  from  imperfect  fusion  are  seeen  on  Us  surface  •  aS 

Ku  n?  r  ^T"'^"^  '"  'T"°i^  ^^^^'^^^^  ^°  "^^^^  "««  "^g'-o""^  flints,  frit  ^  by  means 
of  salt  of  tartar  or  some  other  flux.  It  would  thence  appear  that  the  presence  of  Ulc  U 
of  no  use  towards  the  fusibility  of  the  silica,  and  that  its  absence  may  tesuppned  by  in! 
creasing  the  dose  of  the  flux.  In  all  cases,  however,  we  ought  to  beware  of  metoUic 
oxydes  in  the  sand,  particularly  those  of  iron  and  manganese,  which  IstTrruenlly  ^cur 
and  always  injure  the  whiteness  of  the  frit.  "cqucnuy  occur, 

The  ancients  carried  the  art  of  enamelling  to  a  very  hieh  nerfection   nnrl  w»  «^n-c:«« 
ally  find  beautiful  specimens.of  their  work, 'of  which  wetnSwtrerttT^^^^^^^^^ 
nor  the  manner  of  applying  ,t.      Then,  as  at  present,  each  artist  made  a  mvsTrv  of  the' 
means  that  succeeded  best  with  him,  and  thus  a  multitude  of  curious  proceSrsh7vebe^^^^ 
buned  with  their  authors.    Another  cause  contributes  powerfully  to  tKrt  of  declen" 
sion  m  the  arts.     Among  the  vast  number  of  recipes  which  have^een  pubTshed  for  ihe 

We?be\rocTJ5hl*;r^''-'^^^^^^^  ^ ''''''^  ''"^''^^''^  are  mentioned  that  ian  no 
ce^lannotTw  h^VnT,„^  •"'  """^""^  "^  *  '^*"§^^  *'**  denomination,  or  because  the  substan- 
oW  HenVr^  Inv  .1  '"  ^^^"l^^^^,  or  because  they  are  not  if  the  same  nature  as  of 
w2*  h,^r„nir  IT/  cases,  we  find  it  impossible  to  obtain  satisfactory  results.  What 
r^o«  nil  hZf in/  -r'  ''  ^^''f^^^  ^^^^  ^^^  operations  should  be  resumed  anew,  or 
h,  Z  nL^Sn  n?  ^^  *'"'^^^'^''  ^''*"  the  kuowu  chcmical  facts,  we  should  employ 

in  the  production  of  enamels,  raw  materials  of  the  purest  kind.  ^ 

fJoc^H V„H'l?»ILir.''  in  possession  of  the  best  enamel  processes,  and  they  supply  the 
French  and  other  nations  with  the  best  kinds  of  enamel,  of  every  colored  shade. 


646 


ENAMELS. 


Enamels  are  distinguished  into  transparent  and  opaque ;  in  the  former  all  the  elements 
have  experienced  an  equal  degree  of  liquefaction,  and  are  thus  run  into  crystal  ghiss, 
whilst  in  the  others,  some  of  their  elements  have  resisted  the  action  of  heat  more,  so  that 
their  particles  retain  sufficient  aggregation  to  prevent  the  transmission  of  light.  This 
effect  is  produced,  particularly  by  the  oxyde  of  tin,  as  we  shall  perceive  in  treating  of 
white  enamel. 

The  frits  for  enamels  that  are  to  be  applied  to  metallic  surfaces  require  greater  fusibil- 
ity, and  should  therefore  contain  more  flux  ;  and  the  sand  used  for  these  should  be  calcined 
beforehand  with  one  fourth  its  weight  of  sea-salt ;  sometimes,  indeed,  metallic  fluxes  are 
added,  as  minium  or  litharge.  For  some  metallic  colors,  the  oxydes  of  lead  are  very  in- 
jurious, and  in  this  case  recourse  must  be  had  to  other  fluxes.  Clouet  stales  that  he  had 
derived  advantage  from  the  following  mixtures,  as  bases  for  purples,  blues,  and  some 
other  delicate  colors  : — 

Three  parts  of  silicious  sand,  one  of  chalk,  and  three  of  calcined  borax;  or,  three  of 
glass  (of  broken  crystal  goblets),  one  of  calcined  borax,  one  fourth  of  a  part  of  nitre,  and 
one  part  of  well  washed  diaphoretic  antimony.  These  compositions  afford  a  very  white 
enamel,  which  accords  perfectly  well  with  blue. 

It  is  obvious  that  the  composition  of  this  primary  matter  may  be  greatly  varied ;  bat 
we  should  never  lose  sighi  of  the  essential  quality  of  a  good  enamel ;  which  is,  to  acquire, 
at  a  moderate  heat,  suflScient  fluidity,  to  take  a  shining  surface,  without  running  loo  ihin. 
It  is  not  complete  fusion  which  is  wanted  ;  but  a  pasty  state,  of  such  a  degree  as  may 
give  it,  after  cooling,  the  aspect  of  having  suffered  complete  liquefaction. 

Dead-whiL  Enamel. — This  requires  greater  nicety  in  the  choice  of  its  materials  tham 
any  other  enamel,  as  it  must  be  free  from  every  species  of  tint,  and  be  perfectly  white ; 
hence  the  frit  employed  in  this  case  should  be  itself  composed  of  perfectly  pure  ingre- 
dients. But  a  frit  should  not  be  rejected  hastily  because  it  may  be  somewhat  discolored, 
since  this  may  depend  on  two  causes ;  either  on  some  metallic  oxydes,  or  on  fuliginous 
particles  proceeding  from  vegetable  or  animal  substances.  Now  the  laiiter  impurities  may 
be  easily  removed  by  means  of  a  small  quantity  of  peroxyde  of  manganese,  which  has 
the  property  of  readily  parting  with  a  portion  of  its  oxygen,  and  of  thus  facilitating  the 
combustion,  that  is  to  say,  the  destruction  of  the  coloring  carbonaceous  mailer.  Manga- 
nese indeed  possesses  a  coloring  power  itself  on  glass,  but  only  in  its  highest  slate  of 
oxydizement,  and  when  reduced  to  the  lower  state,  as  is  done  by  incombustible  matters, 
it  no  longer  communicates  color  to  the  enamel  combinations.  Hence  the  proportion  of 
manganese  should  never  exceed  what  is  just;  for  the  surplus  would  cause  color.  Some- 
times, indeed,  it  becomes  necessary  to  give  a  little  mansanej^e  color,  in  order  to  obtain  a 
more  agreeable  shade  of  white ;  as  a  little  azure  blue  is  added  to  linens,  to  brighten  or 
counteract  the  dulness  of  their  yellow  tint. 

A  white  enamel  may  be  conveniently  prepared  also  with  a  calcine  composed  of  twb 
parts  of  tin  and  one  of  lead  calcined  together ;  of  this  combined  oxyde,  one  part  is  melted 
with  two  parts  of  fine  crystal  and  a  very  little  manganese,  all  previously  ground  together. 
When  the  fusion  is  complete,  the  vitreous  matter  is  to  be  poured  into  clear  water,  and  th« 
frit  is  then  dried,  and  melted  anew.  The  pouring  into  water  and  fusion  are  sometimes 
repeated  four  times,  in  order  to  secure  a  very  uniform  combination.  The  crucible  must  be 
carefully  screened  from  smoke  and  flame.  The  smallest  portions  of  oxyde  of  iron  or  cop- 
per admitted  into  this  enamel  will  destroy  its  value. 

Some  practitioners  recommend  the  use  of  washed  diaphoretic  antimony  (antimoniate 
of  potash,  from  metallic  antimony  and  nitre  deflagrated  together)  for  white  enamel ;  but 
this  product  cannot  be  added  to  any  preparation  of  lead  or  other  metallic  oxydes ;  for  it 
would  tend  rather  to  tarnish  the  color  than  to  clear  it  up ;  and  it  can  be  used  therefore 
only  with  ordinary  glass,  or  with  saline  fluxes.  For  three  parts  of  white  glass  (without 
lead)  one  part  of  washed  diaphoretic  antimony  is  to  be  taken ;  the  substances  are  well 
ground  together,  and  fused  in  the  common  way. 

Blue  enamel. — This  fine  color  is  almost  always  obtained  from  the  oxyde  of  cobalt  oi 
some  of  its  combinations,  and  it  produces  it  with  such  intensity  that  only  a  very  little  can 
be  used,  lest  the  shade  should  pass  into  black.  The  cobalt  blue  is  so  rich  and  lively 
that  it  predominates  in  some  measure  over  every  other  color,  and  masks  many  so  that 
they  can  hardly  be  perceived ;  it  is  also  most  easily  obtained.  To  bring  it  out,  however, 
in  all  its  beauty,  the  other  colors  must  be  removed  as  much  as  possible,  and  the  cobalt 
itself  should  be  tolerably  pure.  This  metal  is  associated  in  the  best  known  ores  wiih  a 
considerable  number  of  foreign  substances,  as  iron,  arsenic,  copper,  nickel,  and  sulphur, 
and  it  is  difficult  to  separate  them  completely ;  but  for  enamel  blues,  the  oxyde  of  cobalt 
does  no*  require  to  be  perfectly  free  from  all  foreign  metals;  the  iron,  nickel,  and  copper, 
being  most  prejudicial,  should  be  carefully  eliminated.  This  object  may  be  most  easily 
attained  by  dissolving  tlve  ore  in  nitric  acid,  evaporating  the  solution  to  a  sirupy  consis- 
tence, to  expel  the  excess  of  acid,  and  separate  a  portion  of  arsenic.  It  is  now  diluted 
with  water,  and  solution  of  carbonate  of  soda  is  dropped  slowly  into  it  with  brisk  agita- 


ENAMELS. 


647 


tion,  till  the  precipitate,  which  is  at  first  of  a  whitish  gray,  begins  to  turn  of  a  rose-red 
Whenever  this  color  appears,  the  whole  must  be  thrown  on  a  filter,  and  the  liquid 
which  passes  through  must  be  treated  with  more  of  the  carbonate  of  soda,  in  order 
to  obtain  the  arseniate  of  cobalt,  which  is  nearly  pure.  Since  arsenic  acid  and  iU 
derivatives  are  not  capable  of  communicating  color  themselves,  and  as  they  moreover 
are  volatile,  they  cannot  impair  the  beauty  of  the  blue,  and  hence  this  preparation 
affords  it  m  great  perfection. 

Metallic  fluxes  are  not  the  most  suitable  for  this  color ;  because  they  alwavs  commu- 
nicate a  tint  of  greater  or  less  fdrce,  which  never  fails  to  injure  the  purity  of  the  blue. 
Nitre  IS  a  useful  addition,  as  it  keeps  the  oxyde  at  the  maximum  of  oxydation,  in  which 
•tale  it  produces  the  richest  color. 

Yellow  Enamel.— There  are  many  processes  for  making  this  color  in  enamel ;  but  it 
IS  somewhat  difficult  to  fix,  and  it  is  rarely  obtained  of  a  uniform  and  fine  lint.  It 
may  be  produced  directly  with  some  preparations  of  silver,  as  the  phosphate  or  sulphate; 
but  this  method  does  not  always  succeed,  for  too  strong  a  heat  or  powerful  fluxes  readily 
destroy  it,  and  nitre  is  particularly  prejudicial.  This  uncertainty  of  success  with  the 
raits  of  silver  causes  them  to  be  seldom  employed ;  and  oxydes  of  lead  and  antimony  are 
therefore  preferred,  which  afford  a  fine  yellow  when  combined  with  some  oxydes  that  arc 
refractory  enough  to  prevent  their  complete  vitrification.  One  part  of  white  oxyde  of 
antimony  may  be  taken  with  from  one  to  three  parts  of  white  lead,  one  of  alum,  and 
one  of  sal-ammoniac.  Each  of  these  substances  is  to  be  pulverized,  and  then  all  are  to 
be  exactly  mixed,  and  exposed  to  a  heat  adequate  to  decompose  the  sal-ammoniac.  This 
operation  is  judged  to  be  finished  when  the  yellow  color  is  well  brought  out.  There  is 
produced  here  a  combination  quite  analogous  to  that  known  under  the  name  of  Naples 
yellow.  *■ 

Other  shades  of  yellow  may  be  procured  either  with  the  oxyde  of  lead  alone,  or  by 
adding  to  it  a  little  red  oxyde  of  iron ;  the  tints  varying  with  the  proportion  of  the 
latter. 

Clouet  says,  in  his  memoir  on  enamels,  that  a  fine  yellow  is  obtained  with  pure  oxyde 
of  silver,  and  that  it  is  merely  necessary  to  spread  a  thin  coat  of  it  on  the  spot  to  be  col- 
ored. The  piece  is  then  exposed  to  a  moderate  heat,  and  withdrawn  as  soon  as  this  has 
reached  the  proper  point.  The  thin  film  of  metallic  silver  revived  on  the  surface  being 
removed,  the  place  under  it  will  be  found  tinged  of  a  fine  yellow,  of  hardly  any  thickness. 
As  the  pellicle  of  silver  has  to  be  removed  which  covers  the  color,  it  is  requisite  to  avoid 
fixing  this  film  with  fluxes;  and  it  ought  therefore  to  be  applied  after  the  fusion  of  the 
rest.  The  yellows  require  in  general  little  flux,  and  they  answer  better  with  one  of  a 
metallic  nature. 

Green  Enamel. — It  is  known  that  a  green  color  may  be  produced  by  a  mixture  of  yellow 
and  blue  ;  but  recourse  is  seldom  had  to  this  practice  for  enamels,  as  they  can  be  obtain- 
ed almost  always  directly  with  the  oxyde  of  copper;  or  still  better  with  the  oxjde  of 
throme,  which  has  the  advantage  of  resisting  a  strong  heat. 

Chemists  describe  two  oxydes  of  copper,  the  protoxyde,  of  an  orange  red  color,  wbieh 
communicates  its  color  to  enamels,  but  it  is  difficult  to  fix;  the  deutoxyde  is  blue  in  the 
state  of  hydrate,  but  blackish-brown  when  dry,  and  it  colors  green  all  the  vitreous  com- 
binations into  which  it  enters.  This  oxyde  requires,  at  most,  one  or  two  proportions  of 
flux,  either  saline  or  metallic,  to  enter  into  complete  fusion ;  but  a  much  smaller  dose  is 
commonly  taken,  and  a  little  oxyde  of  iron  is  introduced.  To  four  pounds  of  frit,  for  in- 
stance, two  ounces  of  oxyde  of  copper  and  48  grains  of  red  oxyde  of  iron  are  used  •  and 
the  ordinary  measures  are  pursued  for  making  very  homogeneous  enamel.  ' 

The  green  produced  by  the  oxyde  of  chrome  is  much  more  solid ;  it  is  not  affected  by  a 
powerful  fire,  but  it  is  not  always  of  a  fine  shade.  It  generally  inclines  too  much  to  th« 
dead-leaf  yellow,  which  depends  on  the  degree  of  oxygenation  of  the  chrome. 

Red  Enamel.— We  have  just  stated  that  protoxyde  of  copper  afforded  a  fine  coloi 
when  It  could  be  fixed,  a  result  difficult  to  obtain  on  account  of  the  fugitive  nature  of 
this  oxyde;  slight  variations  of  temperature  enabling  it  to  absorb  more  oxygen  The 
proper  point  of  fusion  must  be  seized,  for  taking  it  from  the  fire  whenever  the  desired 
color  IS  brought  out.  Indeed,  when  a  high  temperature  has  produced  peroxydizement, 
this  may  be  corrected  by  adding  some  combustible  matter,  as  charcoal,  tallow,  tartar, 
&,c.  The  copper  then  returns  to  its  minimum  of  oxydizement,  and  the  red  color  which 
had  vanished,  reappears.  It  is  possible,  in  this  way,  and  by  pushing  the  heat  a  little, 
to  accomplish  the  complete  reduction  of  a  part  of  the  oxyde ;  and  the  particles  of  metallic 
copper  thereby  disseminated  in  a  reddish  ground,  give  this  enamel  the  aspect  of  the 
stone  called  avanturine.  The  surest  and  easiest  method  of  procuring  protoxyde  of 
copper  IS  to  boil  a  solution  of  equal  parts  of  sugar,  and  sulphate  or  rather  acetate  of 
copper,  in  four  parts  of  water.  The  sugar  takes  possession  of  a  portion  of  the  oxygen 
of  the  cupreous  oxjde,  and  reduces  it  to  the  protoxyde;  when  it  may  be  precipitated"  in 
the  form  of  a  granular  powder  of  a  brilliant  red.      After  about  two  hours  of  moderate 


648 


ENAMELIS. 


ENAMELS. 


649 


I 


m 


I 


;'  i 


ebullition,  the  liquid  is  set  aside  to  settle,  decanted  off  the  precipitate,  which  is  washed 
and  dried. 

This  pure  oxyde,  properly  employed  hy  itself,  furnishes  a  red  which  vies  wiih  the  fines 
carmine,  and  by  its  means  every  lint  may  be  obtained  from  red  to  orange,  by  adding  a 
greater  or  smaller  quantity  of  peroxyde  of  iron. 

The  preparations  of  gold,  and  particularly  the  oxyde  and  purple  of  Cassius,  are  like- 
wise employed,  with  advantage,  to  color  enamel  red,  and  this  composition  resists  a  power- 
ful fire  tolerably  well.  For  some  time  back,  solutions  of  gold,  silver,  and  platinum  have 
been  used  with  success  instead  of  their  oxydes ;  and,  in  this  way,  a  more  intimate  mix- 
ture may  be  procured,  and,  consequently,  more  homogeneous  tints. 

Black  Enamel. — Black  enamels  are  made  with  peroxyde  of  manganese  or  protoxyde  of 
iron  ;  to  which  more  depth  of  color  is  given  with  a  little  cobalt.  Clay  alone,  melted 
with  about  a  third  of  its  weight  of  protoxyde  of  iron,  gives,  according  to  Clouet,  a  fine 
black  enamel. 

Violet  Enamel.^The  peroxyde  of  manganese  in  small  quantity  by  itself  furnishes, 
with  saline  or  alkaline  fluxes,  an  enamel  of  a  very  fine  violet  hue ;  and  variations  of 
shade  are  easily  had  by  modifying  the  proportions  of  the  elements  of  the  colored 
frit.  The  great  point  is  to  maintain  the  manganese  in  a  state  of  peroxydation,  and  con- 
sequently to  beware  of  placing  the  enamel  in  contact  with  any  substance  attractive  of 
oxygen. 

Such  are  the  principal  colored  enamels  hitherto  obtained  by  means  of  metallic  oxydes ; 
but  since  the  number  of  these  oxydes  is  increasing  every  day,  it  is  to  be  wished  that  new 
trials  be  made  with  such  as  have  not  yet  been  employed.  From  such  researches  some 
interesting  results  would  unquestionably  be  derived. 

0/  painting  on  Enamel. — Enamelling  is  only  done  on  gold  and  copper;  for  silver  swells 
up,  and  causes  blisters  and  holes  in  the  coat  of  enamel.  All  enamel  paintings  are,  in 
fact,  done  on  copper  or  gold. 

The  goldsmith  prepares  the  plate  that  is  to  be  painted  upon.  The  gold  should  be  22 
carats  fine :  if  purer,  it  would  not  be  sufficiently  stiff;  if  coarser,  it  would  be  subject  to 
melt ;  and  its  alloy  should  be  half  white  and  half  red,  that  is,  half  silver  and  half  copper; 
whereby  the  enamel  with  which  it  is  covered  will  be  les?  disposed  to  turn  green,  than  if 
the  alloy  were  entirely  copper. 

The  workman  must  reserve  for  the  edge  of  the  plate  &  ijmall  fillet,  which  he  calls  the 
border.  This  ledge  serves  to  retain  the  enamel,  and  hinders  it  from  falling  off  when 
applied  and  pressed  on  with  a  spatula.  When  the  plate  is  not  to  be  counter-enamelled,  it 
should  be  charged  with  less  enamel,  as,  when  exposed  to  heat,  the  enamel  draws  up  the 
gold  to  itself,  and  makes  the  piece  convex.  When  the  enamel  is  not  to  cover  the  whole 
plate,  it  becomes  necessary  to  prepare  a  lodgment  for  it.  With  this  view,  all  the  out- 
lines of  the  figure  are  traced  on  the  plate  with  a  black-lead  pencil,  afier  which  recourse 
is  had  to  the  graver. 

The  whole  space  enclosed  by  the  outlines  must  be  hollowed  out  m  bas-relief,  of  a 
depth  equal  to  the  height  of  the  fillet,  had  the  plate  been  entirely  enamelled.  '  This 
sinking  of  the  surface  must  be  done  with  a  flat  graver  as  equally  as  possible;  for  if 
there  be  an  eminence,  the  enamel  would  be  weaker  at  that  point,  and  the  green' would 
appear.  Some  artists  hatch  the  bottom  of  the  hollow  with  close  lines,  which  cross  each 
other  in  all  directions ;  and  others  make  lines  or  scratches  with  the  edges  of  a  file  broken 
off  square.  The  hatchings  or  scratches  lay  hold  off  the  enamel,  which  might  otherwise 
separate  from  the  plate.  After  this  operation,  the  plate  is  cleansed  by  boiling  it  in 
an  alkaline  lye,  and  it  is  washed  first  with  a  little  weak  vinegar,  and  then  with  clear 
water. 

The  plate  thus  prepared  is  to  be  dovered  with  a  coat  of  white  enamel,  which  is  done 

488 


by  bruising  a  piece  of  enamel  in  an  agate  or  porcelain  mortar  to  a  coarse  powder  liks 
sand,  washing  it  well  with  water,  and  applying  it  in  the  hollow  part  in  its  moist  state. 


The  plate  may  meanwhile  be  held  in  an  ordinary  forceps.  The  enamel  powder  is 
spread  with  a  spatula.  For  condensing  the  enamel  powder,  the  edges  of  the  plate  are 
struck  upon  with  the  spatula. 

Whenever  the  piece  is  dry,  it  is  placed  on  a  slip  of  sheet  iron  perforated  with  several 
small  holes,  see  fa.  490,  which  is  laid  on  hot  cinders ;  and  it  is  left  there  until  it 
ceases  to  steam.  It  must  be  kept  hot  till  it  goes  to  the  fire  ;  for  were  it  allowed  to  cool 
it  would  become  necessary  to  heat  it  tiga\n  very  gradually  at  the  mouth  of  the  furnace 
of  fusion,  to  prevent  the  enamel  from  decrepitating  and  flying  off 


a 


a  DC 


H 


„:3 


^3 


Before  describing  the  manner  of  exposing  the  piece  to  the  fire,  we  must  explain  the 
construction  of  the  furnace.  It  is  square,  and  is  shown  in  front  elevation  in  Jiff.  491. 
It  consists  of  two  pieces,  the  lower  part  a,  or  the  body  of  the  furnace,  and  the  upper 
part  B,  or  the  capital,  which  is  laid  on  the  lower  part^  as  is  shown  in  fff.  492,  where  these 
two  parts  are  separately  represented.  The  furnace  is  made  of  good  fire-clay,  moderately 
baked,  and  resembles  very  closely  the  assay  or  cupellation  furnace.  Its  inside  dimen- 
sions are  9  inches  in  width  ;  13  inches  in  height  iu  the  body,  and  9  in  the  capital.  Its 
general  thickness  is  2  inches. 

The  capital  has  an  aperture  or  door  c,  fiff.  491,  which  is  closed  by  a  fire-brick  stopper 
tn,  when  the  fire  is  to  be  made  active.     By  this  door  fuel  is  supplied. 

The  body  of  the  furnace  has  likewise  a  door  d,  which  reaches  down  to  the  projecting 
shelf  E,  called  the  bib  {mentonniere),  whose  prominence  is  seen  at  e,  fp.  491.  This 
shelf  is  supported  and  secured  by  the  two  brackets,  f,  f;  the  whole  being  earthenware. 

The  height  of  the  door  d,  is  abridged  by  a  peculiar  fire-brick  o,  which  not  only  covers 
the  whole  projection  of  the  shelf  e,  but  enters  within  the  opening  of  the  door  d,  filling 
ita  breadth,  and  advancing  into  the  same  plane  with  the  inner  surface  of  the  furnace. 
This  plate  is  called  the  hearth;  its  purpose  will  appear  presently;  it  may  be  taken  out 
and  replaced  at  pleasure,  by  laying  hold  of  the  handle  in  its  front 

Below  the  shelf  e;  a  square  hole,  h,  is  seen,  which  serves  for  admitting  air,  and  for 
extracting  the  ashes.  Similar  holes  are  left  upon  each  side  of  the  surface,  as  is  shown 
in  the  ground  plan  of  the  base,  fg.  492,  at  h. 

On  a  level  with  the  shelf,  in  the  interior  of  the  furnace,  a  thin  fire-tile  i  resta,  per- 
forated with  numerous  small  holes.  This  is  the  grate  represented  in  a  ground  view  in 
fiff.  490.  Figs.  493,  494,  495,  represent,  under  different  aspects,  the  muffle.  Itg.  492  shows 
the  elevation  of  its  further  end ;  fg.  494,  its  sides ;  and  fg.  495,  its  front  part  At  J, 
fig.  492,  the  muffle  is  seen  in  its  place  in  the  furnace,  resting  on  two  bars  of  iron,  or, 
Btill  better,  on  ledges  of  fire-clay,  supported  on  brackets  attached  to  the  lateral  sides  of 
the  furnace.  The  muffle  is  made  of  earthenware,  and  as  thin  as  possible.  The  fuel 
consists  of  dry  beech-wood,  or  oaken  branches,  about  an  inch  in  diameter,  cut  to  the 
length  of  nine  inches,  in  order  to  be  laid  in  horizontal  strata  within  the  furnace,  one 
row  only  being  placed  above  the  muffle.  When  the  mufflle  has  attained  to  a  white  red 
heat,  the  sheet  iron  tray,  bearing  its  enamel  plate,  is  to  be  introduced  with  a  pair  of 
pincers  into  the  front  of  the  muffle,  and  gradually  advanced  toward  its  further  end. 
The  mouth  of  the  muffle  is  to  be  then  closed  with  two  pieces  of  charcoal  only,  between 
which  the  artist  may  see  the  progress  of  the  operation.  Whenever  the  enamel  begins 
to  flow,  the  tray  must  be  turned  round  on  its  base  to  insure  equality  of  temperature ; 


IPv^ 


650 


ENAMELLING. 


ENAMELLING. 


651 


!> 


• 


and  as  soon  as  the  whole  surface  is  melted,  the  tray  must  be  withdrawn  with  its  platS; 
but  slowly,  lest  the  vitreous  matter  be  cracked  by  sudden  refrigeration. 

The  enamel  plate,  when  cold,  is  to  be  washed  in  very  dilute  nitric  acid,  and  aller- 
wards  in  cold  water,  and  a  second  coat  of  granular  enamel  paste  is  to  be  applied,  with 
the  requisite  precautions.  This,  being  passed  through  the  fire,  is  to  be  treated  in  th« 
same  way  a  third  time,  when  the  process  will  be  found  complete.  Should  any  chinki 
happen  to  the  enamel  coat,  they  must  be  widened  with  a  graver,  and  the  space 
being  filled  with  ground  enamel,  is  to  be  repaired  in  the  muffle.  The  plate,  covered 
with  a  pure  white  enamel,  requires  always  to  be  polished  and  smoothed  with  sandstone 
and  water,  particularly  if  the  article  have  a  plane  surface ;  and  it  is  then  finally  glazed 
at  the  fire. 

The  painting  operation  now  follows.  The  artist  prepares  his  enamel  colors  by  pound- 
ing them  in  an  agate  mortar,  with  a  pestle  of  agate,  and  grinding  them  on  an  agate  slab, 
with  oil  of  lavender,  rendered  viscid  by  exposure  to  the  sun  in  a  shallow  vessel,  loosely 
covered  with  gauze  or  glass.  The  grinding  of  two  drachms  of  enamel  pigment  into  an 
impalpable  powder,  will  occupy  a  laborer  a  whole  day.  The  painter  should  have  along- 
side of  him  a  stove  in  which  a  moderate  fire  is  kept  up,  for  drying  his  work  whenever 
the  figures  are  finished.     It  is  then  passed  through  the  muffle. 

Enamelling  at  the  Lamp. — The  art  of  the  lamp  enameller  is  one  of  the  most  agreeable 
and  amusing  that  we  know.  There  is  hardly  a  subject  in  enamel  which  may  aOk  be 
executed  by  the  lamp-flame  in  very  little  time,  and  more  or  less  perfectly,  according  to 
the  dexterity  of  the  artist,  and  his  acquaintance  with  the  principles  of  modelling. 

In  working  at  the  lamp,  tubes  and  rods  of  glass  and  enamel  must  be  provided,  of  all 
sizes  and  colors. 

The  enamelling  table  is  represented  in  Jig.  489,  round  which  several  workmen,  with 
their  lamps,  may  be  placed,  while  the  large  double  bellows  d  below  is  set  a-blowing  by  • 
treadle  moved  with  the  foot.  The  flame  of  the  lamp,  when  thus  impelled  by  a  powerful 
jet  of  air,  acquires  surprising  intensity.  The  bent  nozzles  or  tubes,  a  a  a  a,  are  made 
oC  glass,  and  are  drawn  to  points  modified  to  the  purpose  of  the  enameller. 

Fig.  489  shows,  in  perspective,  the  lamp  a  of  the  enameller  standing  in  its  cistern  b; 
the  blowpipe  c  is  seen  projecting  its  flame  obliquely  upwards.  The  blowpipe  is  adjust- 
able in  an  elastic  cork  d,  which  fills  up  exactly  the  hole  of  the  table  into  which  it  enters. 
When  only  one  person  is  to  work  at  a  table  provided  with  several  lamps,  he  sits  down  at 
the  same  side  with  the  pedal  of  the  bellows;  he  takes  out  the  other  blowpipes,  and  plugt 
the  holes  in  the  table  with  solid  corks. 

The  lamp  is  made  of  copper  or  tin-plate,  the  wick  of  cotton  threads,  and  either  tallow 
or  oU  may  he  ised.  Between  the  lamp  and  the  workman  a  small  board  or  sheel'.of 
white  iron  b,  called  the  screen,  is  interposed  to  protect  his  eyes  from  the  glare  of  light. 
The  screen  is  fastened  to  the  tabic  by  a  wooden  stem,  and  it  throws  its  shadow  on  hia 
face. 

The  enamelling  workshop  ought  to  admit  little  or  no  daylight,  otherwise  the  artist, 
not  perceiving  his  flame  distinctly,  would  be  apt  to  commit  mistakes. 

It  is  impossible  to  describe  all  the  manipulations  of  this  ingenious  art,  over  which 
taste  and  dexterity  so  entirely  preside.  But  we  may  give  an  example.  Suppose  the 
enameller  wishes  to  make  a  swan.  He  takes  a  tube  of  white  enamel,  seals  one  of  its 
ends  hermetically  at  his  lamp,  and  while  the  matter  is  suflliciently  hot.,  he  blows  on 
it  a  minikin  flask,  resembling  the  body  of  the  bird  ;  he  draws  out,  and  gracefully  bends 
the  neck;  he  shapes  the  head,  the  beak,  and  the  tail;  then,  with  slender  enamel  rods 
of  a  proper  color,  he  makes  the  eyes;  he  next  opens  up  the  beak  with  pointed  scissors; 
he  forms  the  wings  and  the  lege;  finally  attaching  the  toes,  the  bird  stands  complete. 

The  enameller  also  makes  artificial  eyes  for  human  beings,  imitating  so  perfectly  the 
colors  of  the  sound  eye  of  any  individual,  as  to  render  it  diflicult  to  discover  that  he 
has  a  blind  and  a  seeing  one. 

It  is  difficult  to  make  large  articles  at  the  blowpipe  ;  those  which  surpass  5  or  6  inches 
become  nearly  unmanageable  by  the  most  expert  workmen. 

Enamelling  of  Cast  Iron  and  other  Hollow  Ware  for  Saucepans,  <fec. — In  De- 
cember, 1799,  a  patent  was  obtained  for  this  process  by  Dr.  Samuel  Sandy  Hickling. 
His  specification  is  subdivided  into  two  parts : — 

1.  The  coating  or  lining  of  iron  vessels,  <fec.,  by  fusion  with  a  vitrifiable  mixture, 
composed  of  6  parts  of  calcined  flints,  2  parts  of  cmnposilion  or  Cornish  stone,  9  parts  of 
litharge,  6  parts  of  borax,  1  part  of  argillaceous  earth,  1  part  of  nitre,  6  parts  of  calx  of 
tin,  and  1  part  of  purified  potash.     Or,  2dly, 

8  parts  of  calcined  flints,  8  red  lead,  6  borax,  5  calx  of  tin,  and  1  of  nitre.     Or,  3dly, 

12  of  potter's  composition,  8  borax,  10  white  lead,  2  nitre,  1  white  marble  calcined, 
1  argillaceous  earth,  2  purified  potash,  and  5  of  calx  of  tin.     Or,  4thly, 

4  parts  calcined  flint.,  1  potter's  composition,  2  nitre,  8  borax,  1  white  marble  cak 
cined,  |  argillaceous  earth,  and  2  calx  of  tin. 


Whichever  of  the  above  compositions  is  taken,  must  be  finely  powdered,  mixed,  fused  ; 
►he  vitreous  mass  is  to  be  ground  when  cold,  sifted,  and  levigated  with  water.  It  is 
then  made  into  a  pap  with  water  or  gum-water.  This  pap  is  smeared  or  brushed  ovei 
the  interior  of  the  vessel,  dried,  and  fused  with  a  proper  heat  in  a  muffle. 

Calcined  bones  are  also  proposed  as  an  ingredient  of  the  flux. 

The  fusibility  of  the  vitreous  compounds  is  to  vary  according  to  the  heat  to  be  applied 
to  the  vessel,  by  using  various  proportions  of  the  siliceous  and  fluxing  materials.  Col. 
ors  may  be  given,  and  also  gilding. 

The  second  part  or  process  in  his  specification  describes  certain  alloys  of  iron  and 
ix'ckel,  which  he  casts  into  vessels,  and  lines  or  coats  them  with  copper  precipitated 
from  its  saline  solutions.  It  also  describes  a  mode  of  giving  the  precipitated  copper  a 
brassy  surface  by  acting  upon  it  with  an  amalgum  of  zinc  with  the  aid  of  heat. 

A  factory  of  such  enamelled  hollow  wares  was  carried  on  for  some  time,  but  it  was 
given  up  for  want  of  due  encouragement. 

A  patent  was  granted  to  Thomas  and  Charles  Clarke  on  the  25th  of  May,  1839,  for 
a  method  of  enamelling  or  coating  the  internal  surfaces  of  iron  pots  and  saucepans,  in 
such  a  way  as  shall  prevent  the  enamel  from  cracking  or  splitting  off"  from  the  eflfecta 
of  fire.  The  specification  prescribes  the  vessel  to  be  first  cleansed  by  exposing  it  to 
the  action  of  dilute  sulphuric  acid  (sensibly  sour  to  the  taste)  for  three  or  four  hours, 
then  boiling  the  vessel  in  pure  water  for  a  short  time,  and  next  applying  the  composition. 
This  consists  of  100  lbs.  of  calcined  ground  flints ;  50  lbs.  of  borax  calcined,  and  finely 
ground  with  the  above.     That  mixture  is  to  be  fused  and  gradually  cooled. 

40  lbs.  weig"/  of  the  above  product  is  to  be  taken  with  5  lbs.  weight  of  potter's  clay ; 
to  be  ground  together  in  water  until  the  mixture  forms  a  pasty-consistenced  mass, 
which  will  leave  or  form  a  coat  on  the  inner  surface  of  the  vessel  about  one  sixth  of  an 
inch  thick.  When  this  coat  is  set,  by  placing  the  vessel  in  a  warm  room,  the  second 
composition  is  to  be  applied.  This  consists  of  125  lbs.  of  white  glass  (without  lead), 
25  lbs.  of  borax,  20  lbs.  of  soda  (crystals),  all  pulverized  together  and  vitrified  by  fu- 
sion, then  ground,  cooled  in  water,  and  dried.  To  45  lbs.  of  that  mixture,  1  lb.  of  soda 
is  to  be  added,  the  whole  mixed  together  in  hot  water,  and  when  dry,  pounded  ;  then 
sifted  finely  and  evenly  over  the  internal  surface  of  the  vessel  previously  covered  with 
the  first  coating  or  composition,  while  this  is  still  moist.  This  is  the  glazing.  The 
vessel  thus  prepared  is  to  be  put  into  a  stove,  and  dried  at  the  temperature  of  212°  F. 
It  is  then  heated  in  a  kiln  or  muffle,  like  that  used  for  glazing  china.  The  kiln  being 
brought  to  its  full  heat,  the  vessel  is  placed  first  at  its  mouth  to  heat  it  gradually,  and 
then  put  into  the  interior  of  the  fusion  of  the  glaze.  In  practice  it  has  been  found  ad- 
vantageous also  to  dust  the  glaze  powder  over  the  fused  glaze,  and  apply  a  second 
fluxing  heat  in  the  oven.  The  enamel,  by  this  double  application,  becomes  much 
smoother  and  sounder. 

Messrs.  Keurick  of  West  Bromwich  having  produced  in  their  factory  ana  sent  into 
the  market  some  excellent  specimens  of  enamelled  saucepans  of  cast  iron,  were  sued  by 
Messrs.  Clarke  for  an  invasion  of  their  patent  rights ;  but  after  a  long  litigation  in 
chancer)',  the  patentees  w^ere  nonsuited  in  the  court  of  exchequer.  The  previous  pro- 
cess of  cleansing  with  dilute  sulphuric  acid  appeared  by  the  evidence  on  the  trial  to 
have  been  given  up  by  the  patentees,  and  it  was  also  shown  by  their  own  principal 
scientific  witness  that  a  good  enamelled  iron  saucepan  could  be  made  by  Hickling's 
specification.  In  fact,  the  formulae  by  which  a  good  enamel  may  be  compounded  are 
almost  innumerable ;  so  that  a  patent  for  such  a  purpose  seems  to  be  untenable,  or  at 
least  most  easily  evaded.  I  have  exposed  the  finely-enamelled  saucepans  of  Messrs. 
Kenrick  to  very  severe  trials,  having  fused  even  chloride  of  calcium  in  them,  and  have 
found  them  to  stand  the  fire  very  perfectly  without  chipping  or  cracking.  I  consider 
such  a  manufacture  to  be  one  of  the  greatest  improvements  recently  introduced  into 
domestic  economy ;  such  vessels  being  remarkably  clean,  salubrious,  and  adapted  t« 
the  most  delicate  culinary  operations  of  boiling,  stewing,  making  of  jellies,  preserves, 
&c.  They  are  also  admirably  fitted  for  preparing  pharmaceutical  decoctions,  and  ordi- 
nary extracts. 

The  enamel  of  the  said  saucepans  is  quite  free  from  lead,  in  consequence  of  the  glass 
which  enters  into  its  composition  being  quite  free  from  that  metal.  In  several  of  the 
saucepans  which  were  at  first  sent  into  the  market  by  Messrs.  Clarke,  their  enamel 
was  found  on  analysis  by  several  chemists  to  contain  a  notable  proportion  of  oxide  of 
lead.  In  consequence  of  the  quantity  of  borax  and  soda  in  the  glaze,  this  oxide  was  so 
readily  acted  upon  by  acids,  that  sugar  of  lead  was  fcf-med  by  digesting  vinegar  in  them 
with  a  gentle  heat.  The  presence  of  this  noxious  metal  formed,  in  my  opinion,  a  legit- 
imate ground  for  contesting  the  patent,  being  in  direct  violation  of  the  terms  of  the 
specification.  Messrs.  Kenwick's  wares  have  been  always  free  from  this  deleterious 
metal.    Messrs.  Clarke,  I  understand,  have  for  some  time  been  careful  to  reject  from 


652 


ENAMELLING. 


ETCHING  VARNISH. 


653 


11 


their  enamel-composition  all  glass  which  contains  lead ;  and  they  now  manufacture  also 
wholesome  enamelled  ware.  Thus  the  public  have  profited  in  a  most  important  point 
by  the  aforesaid  litigation. 

Enamelled  iron  saucepans  had  been  many  years  ago  imported  from  Germany,  and 
sold  in  London.  I  had  occasion  to  analyze  their  enamel,  and  found  to  my  surprise 
that  it  contains  abundance  of  litharge  or  oxide  of  lead.  The  Prussian  government  has 
issued  an  edict  prohibiting  the  use  of  lead  in  the  enamelling  of  saucepans,  which  are  so 
extensively  manufactured  in  Peiz,  Gleiwitz,  &c.  Probably  the  German  ware  sent  to 
England  was  fabricated  for  exportation,  with  an  enamel  made  to  flux  easily  by  a  dose 
of  litharge.  The  composition  of  the  said  enamel  is  nearly  the  same  with  that  which  I 
found  upon  some  of  the  earlier  saucepans  of  Messrs.  Clarke.  Had  their  patent  been 
sustained,  the  important  legal  question  would  have  arisen,  whether  it  gave  the  patentees 
the  power  of  preventing  dealers  from  continuing  to  sell  what  they  had  been  habitually 
doing  for  a  great  many  years. 

A  suitable  oven  or  muffle  for  lining  or  coating  metals  with  enamel  may  have  the  fol- 
lowing dimensions : — 

The  outside,  8  feet  square,  with  14-inch  walls ;  the  interior  muffle,  4  feet  square  at 
bottom,  rising  6  inches  at  the  sides,  and  then  arched  over  ;  the  crown  may  be  18  inches 
high  from  the  floor  :  the  muffle  should  be  built  of  fire-brick,  2^  inches  thick.  Another 
arch  is  turned  over  the  first  one,  which  second  arch  is  7  inches  wider  at  the  bottom,  and 
4  inches  higher  at  the  top.  A  9-inch  wall  under  the  bottom  of  the  muffle  at  its  centre 
divides  the  fireplaces  into  two,  of  IH  inches  width  each,  and  3  feet  3  inches  long.  The 
flame  of  the  fire  plays  between  the  two  arches  and  up  through  a  3-inch  flue  in  front,  and 
issues  from  the  top  of  the  arch  through  three  holes,  about  4  inches  square ;  these  open 
into  a  flue,  i0-|-9  inches,  which  runs  into  the  chimney. 

The  materials  for  the  enamel  body  (ground  flint,  potter's  clay,  and  borax)  are  first 
mixed  together  and  then  put  into  a  reverberatory  furnace,  6  feet  6  inches  long,  by  3 
feet  4  wide,  and  12  inches  high.    The  flame  from  an  18-inch  fireplace  passes  over  the 
hearth.     The  materials  are  spread  over  the  floor  of  the  oven,  about  6  inches  thick,  and 
'united  or  fritted  for  four  or  five  hours,  until  they  begin  to  heave  and  work  like  yeast, 
Urhen  another  coating  is  put  on  the  top,  also  6  inches  thick,  and  fired  again,  and  so  on 
Ihe  whole  day.     If  it  be  fired  too  much,  it  becomes  hard  and  too  refractory  to  work  in 
the  muffles.     The  glaze  is  worked  in  an  oven  similar  to  the  above.   It  may  be  composed 
of  about  one  half  borax  and  one  half  of  Cornish  stone  in  a  yellowish  powder  procured 
from  the  potteries.     This  is  fritted  for  10  hours,  and  then  fused  into  a  glass  which  is 
Enamelled    Cast-Ieon.      Cast-iron  vessels  have  been  exceedingly  well  enamelled 
under  two  difl^erent  patents  within  these  few  years;  at  first,  by  Mr.  Clark,  of  "Wolver- 
hampton, and  in  November,  1846,  by  Messrs.  Kenriek,  of  West  Bromwich.     Before 
the  enamel  is  applied,  the  surface  of  the  iron  should  be  made  quite  clean  and  bright 
The  enamel  consists  of  two  coats;  the  one  forming  the  body,  and  the  other  the  glaze. 
The  body  is  made  by  fusing   100  lbs.  of  ground   flints,  and  75  of  borax,  and  grinding 
40  lbs.  of  this  frit  with  6  lbs.  of  potter's  clay  in  water  till  it  is  brought  to  the  con- 
sistence of  a  pap.     A  coating  of  this  pap  being  applied  and  dried,  but  not  hard,  th€ 
glaze  powder  is  sifted  over  it.     Tliis  consists  of  100  parts  of  Cornish  stone,  in  fine 
powder,  117  of  borax,  3.5  of  soda-ash,  35  of  nitre,  35  of  sifted  slaked  lime,  13  of  wliite 
Band,  and  50  of  pounded  white  glass.     These  are  all  fused  together ;  the  frit  obtained 
is  pulverized.     Of  this  powder  45  pounds  are  mixed  with  1  pound  of  soda-ash,  in  hot 
water ;  and  the  mixture  being  dried  in  a  stove  is  the  glaze  powder.     When  this  powder 
has  been  very  finely  sifted  over  the  body  coat,  the  cast  iron  article  is  put  into  a  stove, 
kept  at  a  temperature  of  about '212°,  to  dry  it  hard  ;  after  which  it  is  set  in  a  muffle 
kiln  to  be  fused  into  a  glaze. 

The  inside  of  pipes  is  enamelled  (after  being  cleaned)  by  pouring  the  above  body 
composition  through  them  while  the  pipe  is  being  turned  about,  to  insure  its  being 
uniformly  coated.  After  the  body  has  become  set,  the  glaze  pap  is  poured  in  in  a  like 
manner.     The  pipe  is  finally  fired  in  the  kiln. 

Enamelled  Leather.  Instead  of  enamelling  the  grain  surface  as  heretofore, 
Mr.  Nossiter  removes  that  surface  by  splitting  or  puffing,  and  then  produces  what  is 
called  "a  finish"  upon  the  surface  thus  fornied,  by  means  of  a  roller,  or  glass  instru- 
ment Or  the  flesh  side  may  be  thus  prepared  for  enamelling;  and  it  is  less  liable  to 
crack  and  the  enamel  to  become  cloudy,  than  the  grain  side.  He  also  shaves  hides  and 
skins  by  knives  set  tangentially  upon  a  rotary  axis,  with  a  certain  degree  of  obliquity. 
He  squeezes  the  grease  out  of  the  skins  by  hard  pressure  between  rollers;  and  he  uses 
a  rotary  brush  to  clear  away  all  filth. 

Enamellino  Metals.      In    February,    1847,   Mr.   Walton    patented    a  method    of 


enamelling  copper  and  other  vessels,  by  coating  them  (after  their  surfaces  are  scaled 
by  heat  and  cleaned)  with  powders  of  a  vitrifiable  kind  applied  in  a  thin  pasty  state 
with  a  brush,  then  drying  and  firing  them.  His  formula  for  the  composition  is  as 
follows:  6  parts  of  flint  glass,  8  of  borax,  1  of  red  lead,  and  1  of  oxide  of  tin  ;  mixed, 
fritted,  ground  into  powder,  made  into  a  thin  paste  with  water,  applied,  dried,  and  fused 
on  by' the  heat  of  an  enamel  kiln  (see  Pottery).  A  second  and  even  a  third  coat  ia 
prescribed.  Into  the  second  he  puts  calcined  bone  in  powder,  with  china  clay  and 
carbonate  of  potash.  These  materials  are  fritted,  ground,  and  mixed  with  certain  of 
the  former  vitrifiable  materials.  Being  reduced  to  a  creamy  consistence  with  water  in 
a  porcelain  mill,  the  mixture  is  painted  on  with  a  brush,  or  applied  by  dipping,  dried, 
and  fired.  One  of  his  formula;  consists  of  4  parts  of  ground  felspar,  4  of  white  sand, 
4  of  carbonate  of  potash,  1  of  arsenic,  6  of  borax,  1  of  oxide  of  tin,  1  of  nitre,  1  of 

whiting being  in  my  opinion  a  most  injudicious  farrago,  for  which  a  much  better  and 

simpler  combination  of  vitrifiable  china-like  materials  might  be  substituted. — NewtorCi 

Journal,  xxxL  p.  183. 
EPSOM  SAyi>^.     Sulphate  of  Magnesia. 

EQUIVALENTS,  CHEMICAL.  {Stochiomdrie,  Germ.)  This  expression  was  first 
employed  by  Dr.  Wollaslon,  to  denote  the  primary  proportions  in  which  the  various 
chemical  bodies  reciprocally  combine;  the  numbers  representing  these  proportion! 
being  referred  to  one  standard  substance  of  general  interest,  such  as  oxygen  or  hydrogen 
reckoned  unity,  or  1,000.  Dr.  Dalton,  who  is  the  true  author  of  the  gra.nd  discovery 
of  definite  and  multiple  chemical  ratios,  calls  these  equivalent  numbers  atomic  weights, 
when  reduced  to  their  lowest  terms,  either  hydrogen  or  oxygen  being  the  radix  of  ihe 
scale.  Though  it  belongs  to  a  chemical  work  to  discuss  the  principles  and  develop  the 
applications  of  the  Atomic  Theory,  I  shall  be  careful,  upon  all  proper  occasions,  to 
point  out  the  vast  advantages  which  the  chemical  manufacturer  may  derive  from  it,  and 
to  show  how  much  he  may  economize  and  improve  his  actual  processes  by  its  means. 
See  Element. 

ESSENCES  are  either  ethereous  oils,  in  which  all  the  fragrance  of  vegetable  products 
reside;  or  the  same  combined  and  diluted  with  alcohol.     See  Oils,  Ethereous. 

ESSENCE  D'ORIENT,  the  name  of  a  pearly  looking  matter  procured  frona  the 
Way  or  bleak,  a  fish  of  the  genus  cyprinus.  This  substance,  which  is  found  principally 
at  the  base  of  the  scales,  is  used  in  the  manufacture  of  artificial  pearls.  A  large  quan- 
tity of  the  scales  being  scraped  into  water  in  a  tub,  are  there  rubbed  between  the  hands 
to  separate  the  shining  stuff',  which  subsides  on  repose.  The  first  water  being  decanted, 
more  is  added  with  agitation  till  the  essence  is  thoroughly  washed  from  all  impurities ; 
when  the  whole  is  thrown  upon  a  sieve ;  the  substance  passes  through,  but  the  scales 
are  retained.  The  water  being  decanted  off",  the  essence  is  procured  in  a  viscid  r*rMe,  of 
a  bluish  white  color,  and  a  pearly  aspect.  The  intestines  of  the  same  fish  are  also 
covered  with  this  beautiful  glistening  matter.  Several  other  fish  yield  it,  but  in  smaller 
proportion.  When  well  prepared,  it  presents  exactly  the  appearance  and  reflections  of 
the  real  pearls,  or  the  finest  mother  of  pearl ;  properties  which  are  probably  owing  to  the 
interposition  of  some  portions  of  this  same  substance,  between  the  laminae  of  these 
shelly  concretions.  Its  chemical  nature  has  not  been  investigated ;  it  putrefies  readily 
when  kept  moist,  an  accident  which  may,  however,  b**  counteracted  by  water  of  ammo- 
nia.    See  Pearls. 

ETCHING  Varnish.  (Jetzgrund-Deckfimissy  Germ.)  Though  the  practice  of  thb 
elegant  art  does  not  come  within  the  scope  of  our  Dictionary,  the  preparation  of  the  var- 
nishes, and  of  the  biting  menstrua  which  it  employs,  legitimately  does. 

The  varnish  of  Mr.  Lawrence,  an  English  artist  resident  in  Paris,  is  made  as  follows: 
Take  of  virgin  wax  and  asphaltum,  each  two  ounces,  of  black  pitch  and  burgundy-pitch 
each  half  an  ounce.  Melt  the  wax  and  pitch  in  a  new  earthenware  glazed  pot,  and  add 
to  them,  by  degrees,  the  asphaltum,  finely  powdered.  Let  the  whole  boil  till  such  time 
as  that,  taking  a  drop  upon  a  plate,  it  will  break  when  it  is  cold,  on  bending  it  double 
two  or  three  times  betwixt  the  fingers.  The  varnish,  being  then  enough  boiled,  must  be 
taken  off"  the  fire,  and  after  it  cools  a  little,  must  be  poured  into  warm  water  that  it  may 
work  the  more  easily  with  the  hands,  so  as  to  be  formed  into  balls,  which  must  be 
kneaded,  and  put  into  a  piece  of  taflety  for  use. 

Care  must  be  taken,  first,  that  the  fire  be  not  too  violent,  for  fear  of  burning  the 
ingredients,  a  slight  simmering  being  sufficient ;  secondly,  that  whilst  the  asphaltum  is 
putting  in,  and  even  after  it  is  mixed  with  the  mgredients,  they  should  be  stirred  con- 
tinually with  the  spatula;  and  thirdly,  that  the  water  into  which  this  composition  is 
thrown  should  be  nearly  of  the  same  degree  of  warmth  with  it,  in  order  to  prevent  a 
kind  of  cracking  that  happens  when  the  water  is  too  cold. 

The  varnish  ought  alwaj's  to  be  made  harder  in  summer  than  in  winter,  and  it  will 
become  so  i£  it  be  s\ifl'ered  to  boil  longer,  or  if  a  greater  proportion  of  the  asphaltum  or 


1 


654 


ETHER. 


.  1 

i 


n 


fctown  rosin  be  used.    The  esperiraent  above  mentioned,  of  the  drop  snffered  to  cool, 
will  determine  the  degree  of  hardness  or  softness  that  may  be  suitable  to  Oie  season 

\ifii6Q  it  is  uscu* 

Preparation  of  the  hard  varnish  used  by  Callot,  commonly  called  the  Florence  Var- 
nish :— Take  four  ounces  of  fat  oil  very  clear,  and  made  of  good  linseed  oil,  like  that 
used  by  painters ;  heat  it  in  a  clean  pot  of  glazed  earthenware,  and  afterwards  put  to  it 
four  ounces  of  mastick  well  powdered,  and  stir  the  mixture  briskly  till  the  whole  be  weU 
melted,  then  pass  the  mass  through  a  piece  of  fine  linen  into  a  glass  bottle  with  a  long 
neck,  that  can  be  slopped  very  securely  ;  and  keep  it  for  the  use  that  will  be  explained 

Method  of  applying  the  soft  varnish  to  the  plate,  and  of  blackening  it :— The  plate 
being  well  polished  and  burnished,  as  also  cleansed  from  all  greasiness  by  chalk  or  Span- 
ish white,  fix  a  hand-vice  on  the  ed^e  of  the  plate  where  no  work  is  intended  to  be,  to 
serve  as  a  handle  for  managing  it  when  waim';  then  put  it  upon  a  chafing  dish,  in  which 
there  is  a  moderate  fire,  and  cover  the  whole  plate  equally  with  a  thin  coat  of  the  var- 
nish ;  and  whilst  the  plate  is  warm,  and  the  varnish  upon  it  in  a  fluid  state,  beat  every 
part  of  the  varnish  gently  with  a  small  ball  or  dauber  made  of  cotton  tied  up  in  taflety, 
which  operation  smooths  and  distributes  the  varnish  equally  over  the  plate. 

When  the  plate  is  thus  uniformly  and  thinly  covered  with  the  varnish,  it  must  be 
blackened  by  a  piece  of  flambeau,  or  of  a  large  candle  which  aflbrds  a  copious  snxxke ; 
sometimes  two  or  even  four  such  candles  are  used  together  for  the  sake  of  despatch,  vnat 
the  varnish  may  noc  grow  cold,  which  if  it  does  during  the  operation,  the  plate  must  be 
heated  again,  that  it  may  be  in  a  melted  state  when  that  operation  is  performed;  but 
great  care  must  be  taken  not  to  burn  it,  which,  when  it  happens,  may  be  easily  perceived 
by  the  varnish  appearing  burnt,  and  losing  its  gloss.  . 

The  menstruum  used  and  recommended  by  Turrell,  an  eminent  London  artist,  lor 
etching  upon  steel,  was  prepared  as  follows : — 

Take  Pyroligneous  acid  4  parts  by  measure. 
Alcohol  1  part,  mix,  and  add 

Nitric  acid  1  part. 

This  mixed  liquor  is  to  be  applied  from  1|  to  15  minutes,  according  to  the  depth 
desired.    The  nitric  acid  was  employed  of  the  strength  of  1-28— the  double  aquafortis  of 

the  shops.  .  .      .         i.  V 

The  eau  forte  or  menstruum  for  copper,  used  by  Callot,  as  also  by  Piranesi,  with  a  slight 
modification,  is  prepared  with  8  parts  of  strong  French  vinegar, 

4  parts  of  verdigris, 

4  ditto  sea  salt, 

4  ditto  sal  ammoniac^ 

1  ditto  alum, 

16  ditto  water. 

The  solid  substances  are  to  be  well  ground,  dissolved  in  the  vinegar,  and  diluted  with 
the  water ;  the  mixture  is  now  to  be  boiled  for  a  moment,  and  then  set  aside  to  cool. 
This  menstruum  is  applied  to  the  washed,  dried,  and  varnished  plate,  after  it  has  suf- 
fered the  ordinary  action  of  aquaf  :rtis,  in  order  to  deepen  and  finish  the  delicate  touches. 
It  is  at  present  called  the  eau  forte  a  passer. 

ETHER  is  the  name  of  a  class  of  very  light,  volatile,  inflammable,  and  fragrant 
spirituous  liquids,  obtained  by  distilling,  in  a  glass  retort,  a  mixture  of  alcohol  with 
almost  any  strong  acid.  Every  acid  modifies  the  result,  in  a  certain  degree,  whence 
several  varieties  of  ether  are  produced.  The  only  one  of  commercial  importance  is 
sulphuric  ether,  which  was  first  made  known  under  the  name  of  sweet  oil  of  vitriol, 
in  1540,  by  the  receipt  of  Walterus  Cordus.  Froberus,  190  years  after  that  date, 
directed  the  attention  of  chemists  afresh  to  this  substance,  under  the  new  denominalioa 

of  efher.  .       *.     ■ .      j 

There  are  two  methods  of  preparing  it ;  by  the  first,  the  whole  quantity  of  acid  and 
alcohol  are  mixed  at  once,  and  directly  subjected  to  distillation  ;  by  the  second,  the  alco- 
hol is  admitted,  in  a  slender  streamlet,  into  a  body  of  acid  previously  mixed  with  a  little 
alcohol,  and  heated  to  220°  Fahr. 

I.  Mix  equal  weights  of  alcohol  at  spec.  grav.  0'830,  and  sulphuric  acid  at  1-842,  by 
introducing  the  former  into  a  large  tubulated  retort,  giving  it  a  whirling  motion,  so 
that  the  alcohol  may  revolve  round  a  central  conical  cavity.  Into  this  species  of  whirl- 
pool the  acid  is  to  be  slowly  poured.  The  mixture,  which  becomes  warm,  is  to  be 
forthwith  distilled  by  attaching  a  sp  iclous  receiver  to  the  retort,  and  applying  the  heat 
of  a  sand-bath.  The  formation  of  ether  takes  place  oMy  at  a  certain  temperature.  If 
the  contents  of  the  retort  be  allowed  to  coo*,  and  be  then  slowly  heated  in  a  water-bath, 
•kohol  alone  will  come  over  for  some  time  without  ether,  till  the  mixture  acquires  Iht 


ETHER. 


655 


proper  degree  of  heat.  The  first  receiver  should  be  a  globe,  with  a  tube  pioceeding 
from  its  bottom,  into  »  second  receiver,  of  a  cylindric  shape,  surrounded  with  ice-cold 
water.  The  joints  must  be  well  secured  by  lutes,  after  the  expanded  air  has  been 
allowed  to  escape.  The  liquid  in  the  retort  should  be  kept  in  a  steady  state  of  ebulli- 
tion. The  ether,  as  long  as  it  is  produced,  condenses  in  the  balloon  and  neck  of  the 
receiver  in  striae ;  when  these  disappear  the  process  is  completed.  The  retort  must  now 
be  removed  from  the  sand ;  otherwise  it  would  become  filled  with  white  fumes  contain- 
ing sulphurous  acid,  and  denser  sirise  would  flow  over,  which  would  contaminate  the 
light  product  with  a  liquid  called  sweet  oil  of  wine. 

The  theory  of  etherification  demonstrates  that  when  strong  sulphuric  acid  is  mixed 
with  alcohol,  there  is  formed,  on  the  one  hand,  a  more  aqueous  sulphuric  acid,  and,  on 
the  other,  sulphovinic  acid.  When  this  mixture  is  made  to  boil,  the  sulphovinic  acid  is 
decomposed,  its  dihydrate  of  carbon  combines  with  the  alcohol,  and  constitutes  ether; 
while  the  proportion  of  sulphovinic  acid  progressively  diminishes.  Mr.  Hennell,  of  the 
Apothecaries'  Hall,  first  explained  these  phenomena,  and  he  was  confirmed  in  his  views 
by  the  interesting  researches  of  Serullas.  The  acid  left  in  the  retort  is  usually  of  a 
black  color,  and  may  be  employed  to  convert  into  ether  half  as  much  alcohol  again  j  on 
experiment  which  may  be  repeated  several  times  in  succession. 

The  most  profitable  way  of  manufacturing  ether  has  been  pointed  out  by  Boullay. 
It  consists  in  letting  the  alcohol  drop  in  a  slender  stream  into  the  acid,  previously  healed 
to  the  etherifyin^  temperature.  If  the  acid  in  this  case  were  concentrated  to  1-846,  the 
reaction  would  be  too  violent,  and  the  ether  would  be  transformed  into  bicarbureted 
hydrogen  (dihydrate  of  carbon).  It  is  therefore  necessary  to  dilute  the  acid  down  to 
the  density  of  1'780  ;  but  this  dilution  may  be  preferably  effected  with  alcohol,  instead  ol 
water,  by  mixing  three  parts  of  the  strongest  acid  with  2  of  alcohol,  specific  gravity 
0-830,  and  distilling  off  a  portion  of  the  ether  thereby  generated ;  after  which  ihe  stream 
of  alcohol  is  to  be  introduced  into  the  tnbulure  of  the  retort  through  a  small  olass  lube 
plunged  into  the  mixture;  this  tube  being  the  prolongation  of  a  metallic  syphon,  whose 
shorter  leg  dips  into  a  bottle  filled  with  the  alcohol.  The  longer  leg  is  furnished  with  a 
stop-cock,  for  regulating  at  pleasure  the  alcoholic  streamlet.  The  distilled  vapors  should 
be  transmitted  through  a  worm  of  pure  tin,  surrounded  by  cold  water,  and  the  condensed 
fluid  received  in  a  glass  bottle.  The  quantity  of  alcohol  which  can  be  thus  converted 
into  ether  by  a  given  weight  of  sulphuric  acid,  has  not  hitherto  been  accurately  deter- 
mined ;  but  it  is  at  least  double.  In  operating  in  this  way,  neither  sulphurous  acid  nor 
sweet  oil  of  wine  is  generated,  while  the  residuary  liquid  in  the  retort  continues  limpid 
and  of  a  merely  brownish  yellow  color.  No  sulphovinic  acid  is  formed,  and  according  to 
the  experiments  of  Geiger,  the  proportion  of  ether  approaches  to  what  theory  shows  to 
be  the  maximum  amount.  In  fact,  57  parts  of  alcohol  of  083  sp.  grav.  being  equiva- 
lent to  46-8  parts  of  anhydrous  alcohol,  yield,  according  to  Geiger,  33§  parts  of  ether; 
and  by  calculation  they  should  yield  37 J. 

The  ether  of  the  first  distillation  is  never  pure,  but  always  contains  a  certain  quantity 
of  alcohol.  The  density  of  that  product  is  usually  0-78,  and  if  prepared  by  the  first  oi 
the  above  methods,  contains,  besides  alcohol,  pretty  frequently  sulphurous  acid,  and 
sweet  oil  of  wine ;  impurities  from  which  it  must  be  freed.  Being  agitated  with  its 
bulk  of  milk  of  lime,  both  the  acid  and  the  alcohol  are  removed  at  the  same  time  •  and 
if  it  be  then  decanted  and  agitated,  first  with  its  bulk  of  water,  next  decanted  into  a 
retort  containing  chloride  of  calcium  in  coarse  powder,  and  distilled,  one  third  of  per- 
fectly pure  ether  may  be  drawn  over.  Gay  Lussac  recommends  to  agitate  the  ether 
first  with  twice  its  volume  of  water,  to  mix  it,  and  leave  it  in  contact  with  powdered 
unslaked  lime  for  12  or  14  hours,  and  then  to  distil  off  one  third  of  pure  ether.  The 
remaining  two  thirds  consist  of  ether  containing  a  little  alcohol.  If  in  preparing  eiher 
by  Boullay's  method,  the  alcohol  be  too  rapidly  introduced,  much  of  this  liquid  will 
come  over  unchanged.  If  in  this  slate  the  ether  be  shaken  with  water,  a  notable  quan- 
tity of  it  will  be  absorbed,  because  weak  alcohol  dissolves  it  very  copiously.  The  above 
product  should  therefore  be  re-distilled,  and  the  first  half  that  comes  over  may  be  con- 
sidered as  ether,  and  treated  with  water  and  lime.  The  other  half  must  be  exposeil 
afresh  to  the  action  of  sulphuric  acid. 

Pure  ether  possesses  the  following  properties.  It  is  limpid,  of  spec.  grav.  0-713  or 
0-715  at  60*;  has  a  peculiar  penetrating  strong  smell;  a  taste  at  first  acrid,  burnin«', 
sweetish,  and  finally  cooling.  It  has  neither  an  acid  nor  alkaline  reaction ;  is  a  non- 
conductor of  electricity,  and  refracts  light  strongly.  It  is  very  volatile,  boiling  at 
96"  or  97  F.,  and  produces  by  its  evaporation  a  great  degree  of  cold.  At  the  tem- 
perature of  62-4,  the  vapor  of  ether  balances  a  column  of  mercury  15  inches  high, 
or  half  the  weight  of  the  atmosphere.  When  ether  is  cooled  to  —24**  F.  it  begins'  to 
crystallize  in  brilliant  white  plates,  and  at  —47°  it  becomes  a  white  crystalline  solid. 
When  vapor  of  ether  is  made  to  traverse  a  red  hot  porcelain  lube,  it  deposites  within  it 
one  half  per  cent,  of  charcoal,  and  there  are  condensed  in  the  receiver  one  and  two  thirds 

42 


656 


EVAPORATION. 


EVAPORATION. 


657 


■V  • 


pei  cent,  of  a  brown  oil,  partly  in  crystalline  scales,  and  partly  viscid.  The  crystalline 
portion  is  soluble  in  alcohol,  but  the  viscid  only  in  ether.  The  remainder  of  the  decom- 
posed eiher  consists  of  bi-carbureteJ  hydrogen  gas,  tetrahydric  carburet,  carbonic  oxyde 
gas,  and  one  per  cent,  at  most  of  gaseous  carbonic  acid. 

Ether  takes  lire  readily,  even  at  so^ae  distance  from  a  flame,  and  it  should  not  there- 
fore be  poured  from  one  vessel  to  another  in  the  neighborhood  of  a  lighted  candle.  It 
raay  be  likewise  set  on  fire  by  the  electric  spark.  It  burns  all  away  with  a  bright  fuligi- 
nous flame.  When  the  vapor  of  ether  is  mixed  with  10  times  its  volume  of  oxygen,  it 
turns  with  a  violent  explosion,  absorbs  6  times  its  bulk  of  oxygen,  and  produces  4  times 
its  volume  of  carbonic  acid  gas. 

Ether  alters  gradually  with  contact  of  air;  absorbing  oxygen, and  progressively  chang- 
ing into  acetic  acid  and  water.  This  conversion  lakes  place  very  rapidly  when  the  ether 
is  boiled  in  an  open  vessel,  while  the  acid  enters  into  a  new  combination  forming  acetic 
ether.  Ether  should  be  preserved  in  bottles  perfectly  full  and  well  corked,  and  kept  in 
a  cool  place,  otherwise  it  becomes  sour,  and  is  destroyed.  In  contains  in  this  slate  15  per 
cent,  of  its  bulk  of  azote,  but  no  oxygen  gas,  as  this  has  combined  with  its  elements. 
Ether  is  composed  of  oxygen  21*24;  hydrogen  ]3*85;  carbon  65*05.  This  composi- 
tion may  be  represented  by  1  prime  equivalent  of  water,  and  4  primes  of  bi-carburetted 
hydrogen  gas ;  in  other  words,  ether  contains  for  1  prime  of  water,  once  as  much  olefiant 
gas  as  alcohol,  and  its  prime  equivalent  is  therefore  468*15  to  oxygen  100.  By  my  ana- 
lysis, as  published  in  the  Phil.  Trans,  for  1822,  ether  is  composed  of  oxygen  27*10;  hy- 
drogen 13-3;  and  carbon  59-6  in  100  parts.  The  density  of  my  ether  was  0*700. 
One  volume  of  vapor  of  ether  consists  of  one  volume  of  aqueous  vapor  and  two 
volumes  of  olefiant  gas  (bi-carbureted  hydrogen),  while  alcohol  consists  of  two  volumes 
of  each. 

ETHER,  ACETIC,  is  used  to  flavor  silent  corn  spirits  in  making  imitsrion  brandy.  It 
may  be  prepared  by  mixing  20  parts  of  acetate  of  lead,  10  parts  of  alcohol,  and  11|  of 
concentrated  sulphuric  acid;  or  16  of  the  anhydrous  acetate,  5  of  the  acid,  and  4|  of  ab- 
solute alcohol ;  distilling  the  mixture  in  a  glass  retort  into  a  very  cold  receiver,  agitating 
along  with  weak  potash  ley  the  liquor  which  comes  over,  decanting  the  supernatant  ether, 
and  rectifying  it  by  re-distillation  over  magnesia  and  ground  charcoal. 

Acetic  ether  is  a  colorless  liquid  of  a  fragrant  smell  and  pungent  taste,  of  spec.  grav. 
0-866  at  45"  F.,  boiling  at  166°  F.,  burning  with  a  yellowish  flame,  and  disengaging  fumes 
of  acetic  acid.     It  is  soluble  in  8  parts  of  water. 

Acetic  ether  may  be  economically  made  with  3  parts  of  acetate  of  potash,  3  of  very 
strong  alcohol,  and  2  of  the  strongest  sulphuric  acid,  distilled  together.  The  first  product 
must  be  re-distilled  along  with  one  fifth  of  its  weight  of  sulphuric  acid;  as  much  ether 
will  be  obtained  as  there  was  alcohol  employed. 

ETHIOPS  is  the  absurd  name  given  by  the  alchemists  to  certain  black  metallic  prepar- 
ations. Martial  eihiops  was  the  black  oxyde  of  iron ;  mineral  ethiops,  the  black  sulphuret 
of  mercury ;  and  ethiops  per  se,  the  black  oxyde  of  mercury. 

EVAPORATION  (Eng.  and  Fr. ;  Abdampfen ;  Mdunsten,  Germ.)  is  the  process  by 
which  any  substance  is  converted  into,  and  carried  oflf  in,  vapor.  Though  ice,  camphor, 
and  many  other  solids  evaporate  readily  in  dry  air,  I  shall  consider,  at  present,  merely  the 
vaporization  of  water  by  heat  artificially  applied. 

The  vapor  of  water  is  an  elastic  fluid,  whose  tension  and  density  depend  upon  the 
temperature  of  the  water  with  which  it  is  in  contact.  Thus  the  vapor  rising  from 
water  heated  to  165°  F.  possesses  an  elastic  force  capable  of  supporting  a  column  of  mer- 
cury 10*8  high  ;  and  its  density  is  such  that  80  cubic  feet  of  such  vapor  contain  one  pound 
weight  of  water ;  whereas  32|  cubic  feet  of  steam  of  the  density  corresponding  to  a  tem- 
perature of  212°  and  a  pressure  of  30  inches  of  mercury,  weigh  one  pound.  When  the 
temperature  of  the  water  is  given,  the  elasticity  and  specific  gravity  of  the  vapor  emitted 
by  it  may  be  found. 

Since  the  vapor  rises  from  ihe  water  only  in  virtue  of  the  elasticity  due  to  its  gaseous 
nature,  it  is  obvious  that  no  more  can  be  produced,  unless  what  is  already  incumbt'Ut  up- 
on the  liquid  have  its  tension  abated,  or  be  withdrawn  by  some  means.  Suppose  the 
temperature  of  the  water  to  be  midway  between  freezing  and  boiling,  viz.,  122°  Fahr.,  as 
also  that  of  the  air  in  contact  with  it,  to  be  the  same  but  replete  with  moisture,  so  that 
its  interstitial  spaces  are  filled  with  vapor  of  corresponding  elasticity  and  specific  gra- 
vity with  that  given  off  by  the  water,  it  is  certain  that  no  fresh  formation  of  vapor  can 
take  place  in  these  circumstances.  But  the  moment  a  portion  of  vapor  is  allowed  to  es 
cap«,  or  is  drawn  off  by  condensation  to  another  vessel,  an  equivalent  portion  of  vapor 
will  be  immediately  exhaled  from  the  water. 

The  pressure  of  the  air  and  of  other  vapors  upon  the  surface  of  water  in  an  open  vessel, 
does  not  prevent  evaporation  of  the  liquid ;  it  merely  retards  its  progress.  Experience 
shows  that  the  space  filled  with  an  elastic  fluid,  as  air  or  other  gaseous  body,  is  capable 
of  receiving  as  much  aqueous  vapor  as  if  it  were  vacuous,  only  the  repletion  of  that 


•pace  with  the  vapor  proceeds  more  slowly  in  the  former  predicament  than  in  the  lat. 
ter,  but  m  both  cases  it  arrives  eventually  at  the  same  pitch.  Dr.  Dalton  has  very  in- 
geniously proved,  that  the  particles  of  aeriform  bodies  present  no  permanent  ob^^tacle  to 
the  introduction  of  a  gaseous  atmosphere  of  another  kind  among  them,  but  merely  obstruct 
Its  dirtusion  momentarily,  as  if  by  a  species  of  friction.  Hence,  exhalation  at  atmospheric 
temperatures  is  promoted  by  the  mechanical  diffusion  of  the  vapors  through  the  air  with 
ventilating  fans  or  chimney  draughts ;  though  under  brisk  ebullition,  the  force  of  the 
steam  readily  overcomes  that  mechanical  obstruction. 

The  quantities  of  water  evaporated  under  different  temperatures  in  like  times  arc 
proportional  to  the  elasticities  of  the  steam  corresponding  to  these  temperatures'  A 
vessel  of  boiling  water  exposmg  a  square  foot  of  surface  to  the  fire,  evanorate«s  726 
grams  m  the  minute;  the  elasticity  of  the  vapor  is  equivalent  to  30  inches  of  mercury. 
To  find  the  quantity  that  would  be  evaporated  from  the  same  surface  per  minute  at  a 
heat  of  88°  F.  At  this  temperature  the  steam  incumbent  upon  water  is  capable  of  sud- 
portmg  1*28  inch  of  mercury ;  whence  the  rule  of  proportion  is  30  :  1*28  *  *  725  •  30*93  • 
showing  that  about  31  grains  of  water  would  be  evaporated  in  the  minute  If  the  air 
contains  already  some  aqueous  vapor,  as  it  commonly  does,  then  the  quantity  of  evaoora- 
tion  will  be  proportional  to  the  difference  between  "he  elastic  force  of  that  vaoor  and 
what  rises  from  the  water.  *^  ' 

Suppose  the  air  to  be  in  the  hygrometric  state  denoted  by  0-38  of  an  inch  of  mercury 
then  the  aW  formula  will  become :  30  :  1*28  -  0*38  :  :  725  :  21*41 ;  showing  that  noJ 
more  than  2Ii  grains  would  be  evaporated  per  minute  under  these  circumstances 

The  elastic  tension  of  the  atmospheric  vapor  is  readily  ascertained  by  the 'old  ex- 
periment  of  Le  Roi,  which  consists  infilling  a  glass  cylinder  (a  narrow  tumbler  for 
example)  with  cool  spring  water,  and  noting  its  temperature  at  the  instant  it  becomes 
so  warm  that  dew  ceases  to  be  deposited  upon  it.  This  temperature  is  that  which  cocre- 
spends  to  the  elastic  tension  of  the  atmospheric  vapor.     See  Vapor  Table  of. 

Whenever  the  elasticity  of  the  vapor,  corresponding  to  the  temperature  of  the  water 
is  greater  than  the  atmospheric  pressure,  the  evaporation  will  take  place  not  only  from 
Its  surface,  but  from  every  point  in  its  interior;  the  liquid  particles  throughout  the 
mass  assuming  the  gaseous  form,  as  rapidly  as  they  are  actuated  by  the  calodc  which 
subverts  the  hydrostatic  equilibrium  among  them,  to  constitute  the  phenomena  of  ebul- 
htion.  This  turbulent  vaporization  lakes  place  at  any  temperature,  even  down  to  the 
Ireezmg  point,  provided  the  pneumatic  pressure  be  removed  from  the  liquid  bv  the 
air  pump,  or  any  other  means.  Ebullition  always  accelerates  evaporation,  as  it  serva 
of  the  water       ^"^"^"""^  particles  not  simply  from  the  surface,  but  from  the  whole  body 

The  vapors  exhaled  from  a  liquid  at  any  temperature,  contain  more  heat  than  the 
fluid  from  which  they  spnng;  and  they  cease  lo  form  whenever  the  supply  of  heat  into 
the  liquid  IS  stopped.  Any  volume  of  water  requires  for  its  conversion  into  vapor  ^« 
and  a  half  times  as  much  heat  as  is  sufficient  to  heat  it  from  the  freezing  to  the  boiUng 
emperalure.  The  hea  ,  m  the  former  case,  seems  to  be  absorbed,  being  inappreciable  by 
the  thermometer  ;  for  steam  is  no  hotter  than  the  boiling  water  from  which  it  rises.  It 
has  been  therefore  called  latent  heat;  in  contradistinction  to  that  perceived  by  the  touch 
and  nieasured  by  the  thermometer,  which  is  called  sensible  heat.  The  quantity  of  he^ 
absorbed  by  one  volume  of  water  in  its  conversion  into  steam,  is  about  1000^  Fahr  • 
It  would  be  adequate  to  heat  1000  volumes  of  water,  one  degree  of  the  same  scale  -w 
to  rais  r.ne  volume  of  boihng  water,  confined  in  a  non-conducting  vessel,  to  118(? 
Were  tne  vessel  charged  with  water  so  heated,  opened,  it  would  be  instantaneously  emp! 
tied  by  vaporization,  ?.nce  the  whole  caloric  equivalent  to  its  constitution  as  steam  i^ 
present.  When,  upon  he  other  hand,  steam  is  condensed  by  contact  with  cold  Mih! 
stances,  so  much  heat  is  set  free  as  is  capable  of  heatin«»  five  and  n  hair  t.rv,^.  •.  •  vT 
of  water,  from  32°  to  212°  F.  If  the  supply  of  hea  ?o  a  copper  be  JiifZ  filT^^' 
and  a  half  will  be  required  to  drive  off  it's'w'ater  in  steam,7ovL'd%n"w'  w     t^Ten 

iressure."^  '  "^  '"^  ^^  ^'^'''^  ^'^'^'  ""^^^  ^^^  atmospheriS 

Equal  weights  of  vapor  of  any  temperature  contain  equal  quantities  of  heat;  for 
example,  the  vapor  exhaled  from  one  pound  of  water,  at  77°  F.,  absorbs  during  its 
formation  and  will  g»7<,»t  in  its  condensation,  as  much  heat  as  the  steam  pro^luced  by 
one  pound  of  water  at  212°  F.  The  first  portion  of  vapor  with  a  tensioniso  inch«J 
occupies  a  space  of  27*31  cubic  feet,*  the  second,  with  a  tension  of  0*92  inch, occupies  « 
space  of  890  cubic  feet.*  Suppose  that  these  890  volumes  were  to  be  compressed  into 
27*31  m  a  cylinder  capable  of  confining  the  heat,  the  temperature  of  the  tapor  wouW 
rise  from  77°  to  212°,  in  virtue  of  the  condensation,  as  air  becomes  .so  hot  by  com 

•  One  pound  ayoirdupoii  of  water  contains  27-72  cubic  inches  ;  one  cubic  inch  of  water  forms  16«6  cubi. 
is  *  r«7%l  !  SwlbKt:        "    "  ""'  ^"^^  ''^''"*'  '^^^  ''*™  2^-2*  '^"''''^  ^«"  «^"«^  •^™» :  "'d  ^n 


658 


EVAPORATIO]^. 


EVAPORATION. 


659 


press-ion  in  a  syringe,  as  to  ignite  amadou.  The  latent  heat  of  steam  at  212?  F.  n 
11800—180=1000;  that  of  vapor,  at  77°,  is  1180—45=1135*';  so  that,  in  fact,  the 
lower  the  temperature  at  which  the  vapor  is  exhaled,  the  greater  is  its  latent  heat,  as 
Joseph  Black  and  James  Watt  long  ago  proved  by  experiments  upon  distillation  and  the 
steam  engine. 

From  the  preceding  researches  it  follows,  that  evaporation  may  be  effected  upon  two 
different  plans : — 

1.  Under  the  ordinary  pressure  of  the  atmosphere ;  and  that  either, 

A,  by  external  application  of  heat  to  boilers,  with  a,  an  open  fire ;  6,  steam ;  c,  hot 
liquid  media, 

B,  by  evaporation  with  air;  a,  at  the  ordinary  temperature  of  the  atmosphere;  b,  by 
currents  of  warm  air. 

2.  Under  progressively  lower  degrees  of  pressure  than  the  atmospheric,  down  to 
evaporation  in  as  perfect  a  vacuum  as  can  be  made. 

It  is  generally  affirmed,  that  a  thick  metallic  boiler  obstructs  the  passage  of  the  heat 
throush  it  so  much  more  than  a  thin  one,  as  to  make  a  considerable  difference  in  their 
relative  powers  of  evaporating  liquids.  Many  years  ago,  I  made  a  series  of  experiments 
upon  this  subject.  Two  cylindrical  copper  pans,  of  equal  dimensions,  were  provided  ; 
but  the  metal  of  the  one  was  twelve  times  thicker  than  that  of  the  other.  Each  being 
charged  with  an  equal  volume  of  water,  and  placed  either  upon  the  same  hot  plate  of 
iron,  or  immersed,  to  a  certain  depth,  in  a  hot  solution  of  muriate  of  lime,  I  found  that 
the  ebullition  was  greatly  more  vigorous  in  the  thick  than  in  the  thin  vessel,  which  I 
ascribed  to  the  conducting  substance  up  the  sides,  above  the  contact  of  the  source  of 
heat,  being  12  times  greater  in  the  former  case  than  in  the  latter. 

If  the  bottom  of  a  pan,  and  the  portions  of  the  sides,  immersed  in  a  hot  fluid  medium, 
solution  of  caustic  potash  or  muriate  of  lime,  for  example,  be  corrugated,  so  as  to  contain 
a  double  expanse  of  metallic  surface,  that  pan  will  evaporate  exactly  double  the  quantity 
of  water,  in  a  given  time,  which  a  like  pan,  with  smooth  bottom  and  sides,  will  do 
immersed  equally  deep  in  the  same  bath.  If  the  corrugations  contain  three  times  the 
quantity  of  metallic  surface,  the  evaporation  will  be  threefold  in  the  above  circum- 
stances. But  if  the  pan,  with  the  same  corrugated  bottom  and  sides,  be  set  over  a  fire, 
or  in  an  oblong  flue,  so  that  the  current  of  flame  may  sweep  along  the  corrugations,  it 
will  evaporate  no  more  water  from  its  interior  than  a  smooth  pan  of  like  shape  and 
dimensions  placed  alongside  in  the  same  flue,  or  over  the  same  fire.  This  curious  fact 
I  have  verified  upon  models  constructed  with  many  modifications.  Among  others,  I 
caused  a  cylindrical  pan,  10  inches  diameter,  and  6  inches  deep,  to  be  made  of  tin- 
plate,  with  a  vertical  plate  soldered  across  its  diameter;  dividing  it  into  two  equal 
semi-cylindrical  compartments.  One  of  these  was  smooth  at  the  bottom,  the  other 
corrugated ;  the  former  afforded  as  rapid  an  evaporation  over  the  naked  fire  as  the 
latter^  but  it  was  far  outstripped  by  its  neighbor  when  plunged  into  the  heated  liquid 
medium. 

If  a  shallow  pan  of  extensive  surface  be  heated  by  a  subjacent  fire,  by  a  liquid  medium 
or  a  series  of  steam  pipes  upon  its  bottom ;  it  will  give  off  less  vapor  in  the  same  time 
when  it  is  left  open,  than  when  partially  covered.  In  the  former  case,  the  cool  in- 
cumbent air  precipitates  by  condensation  a  portion  of  the  steam,  and  also  opposes 
considerable  mechanical  resistance  to  the  diffusion  of  the  vaporous  particles.  In  the 
latter  case,  as  the  steam  issues  with  concentrated  force  and  velocity  from  the  contracted 
orifice,  the  air  must  offer  less  proportional  resistance,  upon  the  known  hydrostatic 
principle  of  the  pressure  being  as  the  areas  of  the  respective  bases,  in  communicating 
vessels. 

In  evaporating  by  surfaces  heated  with  ordinary  steam,  it  must  be  borne  in  mind 
that  a  surface  of  10  square  feet  will  evaporate  fully  one  pound  of  water  per  minute,  or 
725X  10  =  7250  gr.,  the  same  as  over  a  naked  fire;  consequently  the  condensing  sur- 
face must  be  equally  extensive.  Suppose  that  the  vessel  is  to  receive  of  water  2500 
lbs.,  which  corresponds  to  a  boiler  5  feet  long,  4  broad,  and  2  deep,  being  40  cubic 
feet  by  measure,  and  let  there  be  laid  over  the  bottom  of  this  vessel  8  connected  tubes 
each  5  inches  in  diameter  and  5  feet  long,  possessing  therefore  a  surface  of  5  feet  square. 
If  charged  with  steam,  they  will  cause  the  evaporation  of  half  a  pound  of  water  per 
minute.  The  boiler  to  supply  the  steam  for  this  purpose  must  expose  a  surface  of  5 
square  feet  to  the  fire.  It  has  been  proved  experimentally  that  10  square  feet  surface 
of  thin  copper  can  condense  3  lbs.  of  steam  per  minute,  with  a  difference  of  temperature 
of  90  degrees  Fahr.  In  the  above  example,  10  square  feet  evaporate  1  lb.  of  watei 
per  minute;  the  temperature  of  the  evaporating  fluid  being  212°  F.,  consequently 
3:1  :  :  90  :'^.  During  this  evaporation  the  difference  of  the  temperature  is  there- 
fore =  30°.  Consequently  the  heat  of  the  steam  placed  in  connexion  with  the  inte- 
rior of  the  boiler,  to  produce  the  calculated  evaporation,  should  be,  212 -|- 30  =  242?, 
corresponding  to  an  elastic  force  of  536  inches  of  mercury.    Were  the  temperature  oi 


the  steam  only  224,  the  same  boiler  in  the  same  time  would  produce  a  diminished  qiit» 
tity  of  steam,  in  the  proportion  of  12  to  30 ;  or  to  produce  the  same  quantity  the  boiler  oi 
tubular  surface  should  be  enlarged  in  the  profK)rtion  of  30  to  12.      In  general,  however 
steam  boilers  employed  for  this  mode  of  evaporation  are  of  such  capacity  as 'to  give  «• 
unfailing  supply  of  steam. 

I  shall  now  illustrate  by  some  peculiar  forms  of  apparatus,  different  systems  of  cv». 
poration.    Fig,  496  explains  the  principles  of  evaporating  in  vacuo,    a  b  represe&H 


!  ^1  ^  .^'f  '^^"''^^*^  "^'^^  ^^^  ^'^"^^  *^  ^^  evaporated.  The  somewhat  wide  oriiico 
tw«  t,  "  '^u^*^^T"P'"^'^^'"^^^  to  admit  the  hand  for  the  purpose  of  cleaning  it 
it^Z  I  f  out  when  the  operation  is  finished  ;  h  is  the  pipe  of  communication  with  the 
K^Z  fu'  *  '^  *  ^".^^  prolonged  and  then  bent  down  with  its  end  plunged  into  the 
liquor  to  be  evaporated,  contained  in  the  charging  back,  (not  shown  in  the  figure),  h  is 
IS  r,l  ^^^"'^""'cating  with  the  vacuum  pan  at  the  top  and  bottom,  to  show  by  the 
fteight  of  the  column  the  quantity  of  liquid  within.  The  eduction  evaporating  pipe 
c  »s  provided  with  a  stop-cock  to  cut  off  the  communication  when  required,  t  is  a  tube 
lor  the  discharge  of  the  air  and  the  water  from  the  steam-case  or  jacket;  the  refrigerator 
fiil  .K  ^"'■'"^'^  °^  ^^'"  "PPP^^  Jy^s  about  1  inch  in  diameter,  arranged  zig-zag  or  spirally 
ike  the  worm  of  a  st.ll  in  a  cylinder.  The  small  air-tight  condenser  f,  connected  with 
the  efflux  pipe /of  the  refrigerator,  is  furnished  below  with  ft  discharge  cock  ?,  and 
surrounded  by  a  coolmg  case,  for  the  collection  of  the  water  condensed  by  the  refri-er 

w!!h  fi,     '/'  "Pf  M P^'  ^5^?  ''  V"^«  *^'  ^'^*^  furnished  with  a  cock,  which  communicates 
with  the  steam  boiler,  and  through  which  the  pan  a  d  is  heated. 

The  operation  of  this  apparatus  is  as  follows:  after  opening  the  cocks  c  f  e 
and  before  admitting  the  cold  water  into  the  condenser  e,  the  cock  of  the  pipe  fc  ii 
opened,  m  order  that  by  injecting  steam  it  may  expel  the  included  air;  after  which  the 

and  th^  '"t  f  "''  '^  ''i''"'-  IK  ""'T  ""^'  "°^  ^'  '"^^^"^^d  into  the  condense" 
?hl  oK  T  .  k"''^^  '7*'T°"  J^^  ^T'^  ^"^  ^^  evaporated  rises  from  the  charging  back 
through  the  tube  6,  and  replenishes  the  vacuum  pan  to  the  proper  height,  as  shown  bv 
the  register  glass  tube  h.  Whenever  the  desired  evaporation  or  concentr'aSon  is  effect! 
fi,:n  f.  *^°*^^  c  ""^t^e  closed,  the  pipe  k  opened,  so  as  to  fill  the  pan  with  steam,  and 
then  the  efflux  cock  a  is  opened  to  discharge  the  residuary  liquor.  By  shutting  the 
,h.  n'nf  ^r  '  ^"'^^^^n^"^"?  Ihe  cock  6,  the  pan  will  charge  itself  afresh  with  liquor,  and 
the  operation  will  be  begun  anew,  after  b  has  been  shut  and  c  opened. 

The  contents  of  the  close  water  cistern  f,  may  be  drawn  off  during  each  operation. 
For  this  purpose,  the  cock  /must  first  be  shut,  the  cold  water  is  to  be  then  run  out  of 
the  condenser  g,  and  A:  and  g  are  to  be  opened.  The  steam  entering  by  k  makes  the 
water  flow,  but  whenever  the  steam  itself  issues  from  the  cock  g,  this  orifice  must  be 
immediately  shut,  the  cock  /  opened,  and  the  cold  water  again  introduced,  whereupon 
the  condensed  water  that  had  meanwhile  collected  in  the  under  part  of  the  refrigerator 
Bows  off  into  the  condenser  vessel  r.     Since  some  air  always  enters  with  the  liquoj 


i 


1 1 


660 


EVAPORATION. 


gneked  into  the  pan,  it  most  be  removed  at  the  time  of  drawing  oflf  the  water  from  the 
two  condensers,  by  driving  steam  through  the  apparatus.  This  necessity  will  be  less 
argent  if  the  liquor  be  made  to  boil  before  being  Introduced  into  the  vacuum  pan. 

Such  an  apparatus  may  be  modified  in  size  and  arrangement  to  suit  the  peculiar  object 
in  view,  when  it  will  be  perfectly  adapted  for  the  concentration  of  extracts  of  every  kind, 
as  well  as  saline  solutions  containing  vegetable  acids  or  alkalis.  The  interior  vessel  of 
A  B  should  be  made  of  tinned  or  plated  copper.  For  an  account  of  Howard's  vacuum 
pan,  made  upon  the  same  principle,  see  Sugar. 

When  a  boiler  is  set  over  a  fire,  its  bottom  should  not  be  placed  too  near  the  grate,  lest 
it  refrigerate  the  flame,  and  prevent  that  vivid  combustion  of  the  fuel  essential  to  the 
maximum  production  of  heat  by  its  means.  The  evil  influence  of  leaving  too  little  room 
between  the  grate  and  the  copper  may  be  illustrated  by  a  very  simple  experiment.  If  a 
small  copper  or  porcelain  capsule  containing  water  be  held  over  the  flame  of  a  candle  a 
little  way  above  its  apex,  the  flame  will  sufler  no  abatement  of  brightness  or  size,  but 
will  continue  to  keep  the  water  briskly  boiling.  If  the  capsule  be  now  lowered  into  the 
middle  of  the  flame,  this  will  immediately  lose  its  brightness,  becoming  dull  and  smoky, 
covering  the  bottom  of  the  capsule  with  soot;  and  cwing  to  the  imperfect  combustion, 
though  the  water  is  now  surrounded  by  the  flame,  its  ebullition  will  cease. 

Fig.  497  is  a  section  of  two  evaporating  coppers  en  suilBf  so  mounted  as  to  favor  the 


Djuiuiiiiiiiiiiiiiiiiiijjiiiiuuinniui' 


"'.1..  '.'T?fj.l'.  '..\ 


a 


b 


full  combustion  of  the  fuel,  a  is  the  hearth,  in  which  wood  or  coal  may  be  burned.  For 
coal,  the  grate  should  be  set  higher  and  be  somewhat  smaller,  a  is  the  door  for  feeding 
the  fire;  rf,  an  arch  of  fire-bricks  over  the  hearth ;  c,  a  grate  through  which  the  ashes 
fall  into  the  pit  beneath,  capable  of  being  closed  in  front  to  any  extent  by  a  sliding  door 
b,  B  and  c  are  two  coppers  incased  in  brickwork  ;  /  the  flue.  At  the  end  of  the  hearth 
near  m,  where  the  fire  plays  first  upon  the  copper,  the  sole  is  made  somewhat  lower  and 
wider,  to  promote  the  spreading  of  the  flame  under  the  vessel.  The  second  copper,  c, 
receives  the  benefit  of  the  waste  heat ;  it  may  be  placed  upon  a  higher  level,  so  as  to 
discharge  its  concentrated  liquor  by  a  slop-cock  or  syphon  into  the  first.  When  coals 
are  burned  for  heating  such  boilers,  the  grate  should  be  constructed  as  shown  in  the 
figure  of  the  brewing  copper,  page  122. 

Fig.  498  represents  a  pan  for  evaporating  liquids,  which  are  apt,  during  concentra- 
tion, to  let  fall  crystals  or  other  sediment. 
These  would  be  injured  either  by  the  fire  play 
ing  upon  the  bottom  of  the  pan,  or,  by  adhesion 
to  it,  they  would  allow  the  metal  to  get  red  hot, 
and  in  that  state  run  every  risk  of  being  burnt 
or  rent  on  the  sudden  intrusion  of  a  little  liquor 
through  the  incrustation.  When  large  coppers 
have  their  bottoms  planted  in  loam,  so  that  the 
flame  circulates  in  flues  round  their  sides,  they 
are  said  to  be  cold-set. 

A  is  a  pear-shaped  pan,  charged  with  the 
liquid  to  be  evaporated ;  it  is  furnished  with  a 
dome  cover,  in  which  there  is  an  opening  with 
a  flange  /,  for  attaching  a  tube,  to  conduct  the 
steam  wherever  it  may  be  required,  a  is  the 
fire-place  ;  b  the  ash-pit.  The  conical  part  ter- 
minates below  in  the  tube  g,  furnished  with  a 
stop-cock  at  its  nozzle  h.  Through  the  tube 
c  d  c',  furnished  above  and  below  with  the  stop- 
cocks c  and  c',  the  liquid  is  run  from  the 


EXPANSION. 


661 


charging  back  or  reservoir.  During  the  operation,  the  upper  cock  c  is  kept  partially 
open,  to  replace  the  fluid  as  it  evaporates ;  but  the  under  cock  c'  is  shut.  The  flame 
from  the  fire-place  plays  round  the  kettle  in  the  space  «,  and  the  smoke  escapes  down- 
wards through  the  flue  t  into  the  chimney.  The  lower  cylindrical  part  g  remains  thus 
comparatively  cool,  and  collects  the  crystalline  or  other  solid  matter.  After  some  time, 
the  under  stop-cock  c',  upon  the  supply-pipe,  is  to  be  opened  to  admit  some  of  the  coW 
liquor  into  the  cylindrical  neck.  That  cock  being  again  shut,  the  sediment  settled,  and 
the  large  stop  cock  (a  horizontal  slide-valve  would  be  preferable)  h  opened,  the  crystals 
are  suffered  to  descend  into  the  subjacent  receiver;  after  which  the  stop-cock  h  is  shut, 
and  the  operation  is  continued.  A  construction  upon  this  principle  is  well  adapted  for 
heating  dyeing  coppers,  in  which  the  sediment  should  not  be  disturbed,  or  exposed  to  the 
action  of  the  fire.     The  fire-place  should  be  built  as  for  the  brewing  copper. 

Fig.  499  represents  aa 
499  oblong  evaporating  pan, 

in  which  the  flame,  aAer 
beating  along  its  bottom, 
turns  up  at  its  further 
end,  plays  back  along  Uf 
surface,  and  passes  off  in* 
to  the  chimney,  a  is  a 
rectangular  vessel,  from 
10  to  15  feet  long,  4  to  6 

r   t  A  T«u     c     1-  .  .  ^^^^  broad,  and  1  or  1* 

leet  deep.  The  fire-bricks,  upon  which  the  pan  rests,  are  so  arranged  as  to  distribute 
the  name  equably  along  its  bottom. 

For  the  following  scheme  of  generating,  purifying,  and  condensing  steam,  Mr.  Charles 
Clarke  merchant,  London,  obtained  a  patent  in  January,  1843.  His  apparatus  for 
XTrfr^no ^"^^-^'Vk  ""^  economically  into  good  fresh  water,  is  represented  in  figs. 
BOO,  501  602.  A  IS  the  supply  cistern,  which  communicates  with  a  pipe  a,  with  a 
self-regulating  eduction  apparatus  n.  c  is  a  strong  wrought  iron  cylinder,  fitted  at 
fhlrVn  H  *>rT  ""g-pl'^cec,  and  covered  with  a  conical  top;  it  is  about  two 
thirds  filled  with  the  water  to  be  operated  upon,  d  is  a  cylindrical'  furnace  concentric 
with  the  water  cylinder  c;  rf is  an  upward  air  and  watertight  tube,  which  serves  both 

ZihtiT^'  ^T^^'  ^/^'"'^  i^"  l""^^  ''  ^"PP"^^  *«  the  furnace^  and  as  a  passage 
for  the  escape  of  the  smoke  and  other  gaseous  products  of  combustion;  e  is  a  hinged 
trap-door  through  which  the  fuel  is  passed  into  the  tube  d:  h  is  a  chimney  into  which 
the  pipe  d  terminates:  and  e,  a  damper,  by  which  the  degree  of  activity  given  to  the 
furnace  can  be  regulated  at  pleasure; /is  an  open  air-pipe,  which  l/ads  from  he 
outs.de,  through  the  boiler  into  the  furnace,  a  kittle  way  above  the  fire-bar^  and 
nssista  in  securing  a  good  draught  through  the  furnace  iito  the  chimney.  To  the 
water  cylinder  o  there  are  attached  gauge-cocks,  g  g,  for  ascertaining  from  time  to 
time  the  height  of  the  water;  /  is  a  cock  or  tap  fo? drawing  off  the  brine,  and^the? 
residual  matters  which  collect  at  tire  bottom  of 'the  boiler;  fn  is  a  screw  cap  and  hole 
through  which  access  may  be  had  to  the  interior  of  the  water  cylinder  g.  when  ii 
needs  to  be  cleaned;  e  is  a  short  pipe  fitted  into  the  conical  top  of  the  water  cylinder 
<;  which  conveys  the  steam  generated  in  it  into  the  steam-head  or  receiver  f-  o  is  a 
TZ^ll  5  k  ''*^'"^-  "P^"  ^*^«,^P  «f  the  pipe  E,  a  little  larger  than  that  pipe,  and 
kept  steady  by  a  weight,  k  of  one  or  more  pounds,  suspended  from  it  W  wires. 
This  plate  prevents,  m  a  great  measure,  the  escape-water  escaping  into  the  steam-head 
(an  accident  commonly  called  prtming  m  steam  engines);  becaufe,  till  the  steam  has 
acquired  a  pressure  exceeding  that  of  the  counterweight  h  it  cannot  raise  the  weight 
o^^  so  as  to  escape  freely  into  the  steam-head  f,  since  any  particle  of  water  must,  during 
the  ns.ng  of  the  cap  g.  strike  against  it.  and  drop  back,  either  into  the  water  iylindef 
hi^T^  ^  P'^.  *^  '''  'l^  ^^t  jPa^e  round  that  pipe  at  the  bottom  of  the  steam- 
head  h;  whence  it  may  be  withdrawn  by  the  cock  shown  in  the  drawing,  h  is  a 
pipe  which  conveys  the  steam  from  the  steam-head  f  to  the  rectifier  a.  This  consists 
simply  of  a  cylinder  about  one  third  the  size  of  the  cylinder  c)  laid  horizontally,  in 

l«l i^i  f  P^'i  "^'"'''Z  \^^  ^^  ;^*J''  'P"^^"^  «<>"«<^^  *n<i  serves  to  retain  any 
particle  of  undecomposed  matter,  which  may  come  over  with  the  steam,  as  it  con 
tinues  to  flow  in  from  the  boiler;  whereby  only  its  purer  portion*  may  pass  off  from 
the  rectifier  B,  by  the  pipe  n.  n  is  a  cock  or  tap,  at  the  bottom  of  the  cylinder  r  for 
drawing  off  its  water  occasionally ;  ei  is  a  second  steam-rectifier,  like  a,  into  which  the 
steam  passes  from  the  pipe  n,  and  is  thereby  still  further  purified;  but  when  the 
proportion  of  saline  matter  is  small,  r«  may  be  dispensed  with,  and  for  very  foul  water 
two  or  three  more  such  rectifiers  may  be  added. 

The  condenser  for  liquefying  the  purified  steam,  and  aerating  the  resulting  water 
18  shown  at  t\  C,  fi  It  18  composed  of  conical  upright  compartments  communicating 
with  each  other;  the  chamber  ti  is  surrounded  by  the  water  in  the  cistern  A  (slighUy 


I'l 


662 


EVAPORATION. 


heated  by  tiie  steam  in  that  chamber),  while  the  chambers  fi  and  fi  are  exposed  freely 
to  the  air.  The  lowest  of  these,  t\  terminates  at  bottom  in  a  tube,  u,  containing  at  the 
mouth  of  the  cone  two  or  three  plates  of  perforated  zinc,  for  admission  of  the  atme- 


•phere.  An  upright  steam-tight  tube  of  zinc,  at  about  the  middle  of  the  lowest 
chamber,  <3,  and  is  continued  to  the  top  of  the  uppermost  chamber,  i',  having  two  lateral 
branches.  This  tube  is  closed  at  its  lower  end,  but  open  at  top,  and  at  the  ends  of  the 
two  branches,  to  give  a  draught  of  cool  air  into  the  tube,  and  a  rapid  flow  of  heated 
air  from  the  top  of  the  tube.  W,  W,  are  pipes  which  pass  externally  from  about  the 
middle  of  the  chamber  <2,  to  near  the  bottom  of  the  chamber  /3.  At  their  lops  they 
are  of  large  dimensions,  as  represented,  but  diminish  gradually  to  small  pipes  at  bottoia 
Of  these  pipes,  there  should  be  as  many  as  can  be  conveniently  applied,  in  order  that 
the  process  of  condensation  may  be  effectually  promoted. 

From  the  second  rectifier,  R',  the  steam  is  conveyed  by  a  pipe,  Wf  of  graduaUy  in. 
creasing  dimensions,  to  near  the  top  of  the  middle  chamber,  i.  whence  it  diffuses  itself 
through  the  three  chambers,  where  it  gets  condensed.  The  hottest  steam  passes  int« 
<*,  and  is  there  most  powerfully  condensed.  The  main  body  of  the  water  produced 
therefrom,  either  drops  directly  into  the  bottom  of  the  chamber  <3,  or  runs  down  the  io* 
dined  sides  of  the  chambers  /»,  /2,  <3,  thence  through  the  outer  pipes  W,  W,  and  out  at 
the  bottom  of  the  tube,  getting  partially  aerated  in  its  progress,  by  means  of  the  air  as- 
cending constantly  through  the  tube  u. 

Z,  Z,  is  an  auxiliar  steam-pipe  from  the  rectifier  R»,  passing  twice  or  thrice  closa 
roand  the  water  supplying  the  cistern,  A,  and  terminating  in  a  cylinder  which  commu- 
nicates by  pipes  with  the  chambers,  i^  and  <3 ;  whereby  all  the  water  thus  condensed 


EVAPORATION. 


663 


may  fall  through  the  perforated  zinc  plates,  into  the  general  discharge  tube,  w.  x  ii 
an  outer  casing  of  wood  or  metal,  leaving  a  small  space  round  the  condenser,  with 
draught-holes,  «,  a^  for  the  admission  of  air.  The  refrigerator  is  made  of  protected 
metal  "(tinned  copper?),"  and  divided  into  three  compartments,  y',  y«,  y'. 

In  the  top  of  y>,  the  end  of  the  discharged  tubett  is  inserted;  and  at  a  little  distance 
from  this  tube  there  are  air  apertures,  a,  a,  furnished  with  shutters  in  the  inside, 
slanting  from  the  top  downward,  to  prevent  as  much  as  possible  the  escape  outward 
of  any  vapor  which  may  occasionally  be  carried  down  with  the  water  from  the  con- 
denser. The  middle  compartment,  y2,  is  perforated,  convex  at  top,  and  concave  at 
bottom ;  so  that  the  water  that  drops  from  the  tube  «,  in  the  convex  top  of  y2,  falls  off 
laterally  through  small  pipes  into  the  chamber  y%  while  its  concave  bottom  turns  the 
water  into  a  central  filtering-box,  c,  that  projects  a  little  into  y3,  set  to  receive  it. 
For  aerating  this  water,  the  bottom  of  yz  is  covered  about  an  inch  deep  with  small 
pebbles.  y3,  which  is  the  reservoir  of  the  purified  cool  water,  is  perforated  with  small 
holes,  c',  ci,  are  small  pipes  for  promoting  a  continual  upward  flow  of  cold  air.  y»  is 
furnished  with  a  tap  to  draw  off  its  water,  as  required. 

For  redistilling  or  rectifying  spirituous  liquids,  the  apparatus,  ^g.  501 ,  is  employed ; 
m  which  the  supply  cistern  A  is  much  larger,  and  close  at  top ;  the  upper  condensing 
chambers,  <',  i%  are  also  larger,  but  the  lowest,  ft,  is  narrowed.  The  second  rectifier 
of^.  500,  is  removed.  The  feints  collect  in  the  bottom  of  the  rectifier  R,  to  be  drawn 
off  by  a  cock ;  while  the  rectified  spirit  passes  off  at  top  into  the  condenser.  The  refri- 
gerator has  only  two  compartments,  and  no  pebbles.  F  is  a  funnel  into  which  the 
spirits  may  be  returned  for  redistillation. 

For  extracting  the  soluble  matter  of  vegetable  infusions,  the  apparatus,  shown  in 
fig.  502,i3  used.     The  rectifier  is  vertical,  has  a  screw-capped  hand-hold,  /,  for  admitting 
th€  vegetables,     g  is  a  steam-pipe ;  and  A  is  a  funnel  for  returning  portions  of  the 
liquid  extract.     R  is  connected  by  a  pipe,  fe,  with  the  condenser,  T,  made  in  two  por- 
tions, fitted  water-tight  together,  but  separable  for  the  purpose  of  cleansing.     The 
steam  which  passes  from  the  boiler  into  the  rectifier  r  disengages  the  soluble  portion 
of  the  vegetable  substances,  and  if  they  be  volatile,  carries  them  off  to  the  condenser; 
if  not,  it  combines  and  falls  with  them  to  the  bottom  of  the  vessel,  whence  this  portion 
of  the  extract  is  drawn  off  by  the  cock,  and  a  fresh  charge  may  be  introduced.     The 
steam  is  shut  off  from  the  rectifier  r  by  a  cock  on  pipe  g.     When  the  steam  is  after- 
ward admitted  to  assist  the  process  of  maceration,  the  supply  of  it  is  regulated  by  th« 
stop-cocks  in  the  pipes  g  and  k. — Newton\t  Journal,  xxiii.  p.  247,  C.  S. 

In  each  experiment  1,840  lbs.  weight  were  burnt,  and  the  relative  quantities  of  water 
evaporated  show  the  relative  economic  effect  Two  kinds  of  coal  were  used :  Knowles'a 
Clifton  coal,  a  free  burning  kind  which  does  not  cake,  and  produces  a  considerable 
quantity  of  ashes ;  Barker  and  Evan's  Oldham  coal,  a  slow  burning  rich  caking  coal, 
yielding  little  ashes.     The  boiler  was  a  24-hor8e  power,  of  Wait's  waggon  shape. 

Mr.  IT.  HouldswortKs  Economy  of  Evaporation. 


Eflect  per  Minute. 

Water  evapo 
rated  by 

Average 

Tempe- 

Eco- 

Wei^Ut of  Cbaije. 

Air. 

Coals 

Water 

1.840 

1  b.  of 

rature  in 
the  first 

nomic 
Eflect 

% 

burnt. 

etapo- 
rated. 

lbs.  of 
CoaL 

CoaL 

Flue. 

1 

Clifton  coal: 

Lht. 

GalU. 

GaJU. 

Lbt. 

Dcgreet. 

460  Ihs. 

No  air     - 

4-64 

2-5 

992 

5-41 

973 

106 

bs 

Q 

460  1bfl. 

45    square    Inches    constant 

s 

aperture          ... 

4-68 

3-21 

1263 

G-85 

1165 

135 

230  lbs. 

Air  regulated    partly  by  the 
eye,  and  partly  by  a  scale, 
varying  in  some  degree  with 

•if 

o 

the  action  of  combustion     • 

443 

809 

1280 

694 

1122 

136 

^ 

230  lbs. 

45  square  inches 

4-65 

305 

1210 

6^ 

1220 

129 

>k 

230  lbs. 

No  air     - 

4-43 

2-3 

942 

512 

995 

100 

"a 

460  lbs. 

Air  through  two  pipes  6  in. 
in  diameter,  each  regulated 

by  light           -          -          - 

4-65 

SIS 

1250 

6-8 

1160 

134 

i 

Oldham  coal : 

230  ll)«. 

No  air     - 

S«7 

2-65 

1S40 

7-3 

690 

100 

E 

.3 

230  \\M. 

35    square    inches    constant 

aperture 

405 

2-76 

1260 

6-85 

1080 

94 

230  Iba 

24     square    inches    constant 

a 

aperture         ... 

382 

2-82 

1360 

7-4 

1050 

102 

460  &  230  Ibe. 

Air  regulated  by  s  scale 

3-84 

2.94 

1410 

7.7 

1070 

106 

Ad 

230  lbs. 

Air  regulated   so  as  to  pro- 

1^ 

duce  no  smoke 

361 

2-87 

1530 

83 

lav) 

114 

N 

Uald  Oldham, 

1 

half  Clifton- 

.... 

AM 

29 

1320 

7-2 

1060 

664 


EXPANSION. 


EXPANSION. 


665 


h  ! ' 


I  il  I 


II 


85  per  cent 
34      „ 
4       » 


The  average  heat  given  in  the  first  flue,  as  ascertained  by  a  pyrometer  and  deduced 
from  pyrometric  diagrams.  The  air  was  admitted  partly  at  the  door  and  partly  at  the 
bridge ;  at  the  latter  point  through  one  of  Mr.  Williams's  diffusion  boxes,  except  in  the 
last  experiment  with  Clifton  coal.  They  showed  the  effect  of  admitting  air  in  greater 
or  less  quantity  permanently  or  periodically  by  a  uniform  or  varying  aperture ;  and  the 
general  result  arrived  at  is,  that  by  the  simple  and  inexpensive  plan  of  admitting  air 
into  the  furnaces  at  both  the  door  and  bridge  by  permanent  apertures  always  open, 
varying  in  aggregate  area  from  1^  to  3  square  inches  (according  to  the  quality  of  the 
coals)  for  every  square  foot  of  area  of  grate,  an  important  saving  in  fuel  is  effected,  an^ 
^9_  of  the  dense  smoke  prevented,  without  any  special  care  of  the  fireman. 

Deductions  from  the  experiments  on  Clifton  Coal: 

Gain  in  evaporation  by  regulated  admission  of  air 

I)o.  by  45  square  inches  constant  aperture 

Do.  by  charges  of  460  lbs.  instead  of  230  lbs. 

Steam  produced  in  a  given  time : — 

^o  air  -  .  230  lbs.  charges 

No  air  -  -  460  lbs.     do. 

53  square  inches  air  -  230  lbs.     do. 
Air  regulated  -  -  230  lbs.     do. 

63  square  inches         -  460  Iba     do. 
showing  that  the  admission  of  air  increases  the  production  of  steam  in  a  given  time 
from  30  to  40  per  cent 

EUDIOAIKTER,  is  the  name  of  any  apparatus  subservient  to  the  chemical  examina* 
tion  of  the  atmospheric  air.  It  means  a  measure  of  purity,  but  it  is  employed  merely  to 
determine  the  proportion  of  oxygen  which  it  may  contain.  The  explosive  eudiometer,  ia 
which  about  two  measures  of  hydrogen  are  introduced  into  a  graduated  glass  tube,  con- 
taining five  measures  of  atmospheric  air,  and  an  electric  spark  is  passed  across  the  mix- 
ture, is  the  best  of  all  eudiometers ;  and  of  these  the  syphon  form,  proposed  by  me  in  a 
paper  published  by  the  Royal  Society  of  Edinburgh  in  1819,  is  probably  the  surest  and 
most  convenient.  Volta's  explosive  eudiometer,  as  made  in  Paris,  costs  3  guineas ;  min« 
may  be  had  nicely  graduated  for  6  or  8  shillings. 

EXPANSION  (Eng.  and  Fr. ;  Ausdehnung^  Germ.)  is  the  increase  of  bulk  experienced 
by  all  bodies  when  heated,  unless  a  change  of  chemical  texture  takes  place,  as  in  tha 
case  of  clays  in  the  potter's  kiln.  Table  i.  exhibits  the  linear  expansion  of  several  solida 
by  an  increase  of  temperature  from  32^  to  212**  Fahr. ;  Table  II.  exhibits  the  expansion 
in  bulk  of  certain  liquids. 

TABLE  l.^Linear  Dilatation  of  Solids  by  Heat, 
Dimensions  which  a  bar  takes  at  212°,  whose  length  at  32?  is  1-000000. 


100 
109 
132 
134 
140 


Dilatation 

Dilatation 

Substances 

Authority. 

in 

in  Vulgar 

Decimals. 

Fractions. 

Glass  tube  -        -        -        -        - 

Smeaton 

1-00083333 

do.     -        ...        - 

Roy    -        .        - 

1-00077615 

do.         •        -        .        .        . 

Deluc's  mean  - 

1-00082800 

niB 

do.     ....        . 

do.         ..... 

Dulong  and  Petit 
Lavoisier  and  Laplace 

1-00086130 
1-00081166 

TTTl 

Plate  glass       -        -        -        . 

do.                do. 

1-000890890 

ll^J 

do.  crown  glass      ... 

do.               do. 

1-00087572 

Ti4iy 

do.          do.         ... 

do.               do. 

1-00089760 

IT  XT 

do.          do.             ... 

do.               do. 

1-00091751 

10^ 

do.  rod       -        .        -        , 

Roy 

1-00080787 

Deal 

Roy,  as  glass 

1 

Platina 

Borda     -        -        - 

1-00085655 

do.         ..... 

Dulong  and  Petit 

1-00088420 

1 
TT3T 

do.     ....        . 

Troughton 

1  00099 180 

do.  and  glass  .... 

Berthoud     . 

1-00110000 

Palladium         .... 

Wollaston 

1-00100000 

Antimony    .        .        -        -        - 

Smeaton 

1-00108300 

Cast-iron  prism        ... 

Roy        .        .        - 

1-00110940 

Cast-iron     ..... 

Lavoisier,  by  Dr  Young: 

1-00111111 

Steel        

Troughton 

100118990 

Substances. 


do.  at  a  higher  heat 


Steel  rod      ... 
Blistered  Steel     - 

do. 
Steel  not  tempered 
do.      do. 

do.  tempered  yellow   . 
do.      do.  do. 

do.      do. 
Steel   - 

Hard  Steel 

Annealed  steel    .... 

Tempered  steel    -        .        -        - 

Iron    --...- 

do.     .....        . 

Soft  iron,  forged    -         .         .        - 
Round  iron,  wire  drawn 
Iron  wire     -         -         .         .         - 
Iron    -        .        .        .        ... 

Bismuth       ..... 

Annealed  gold     .... 

Gold 

do.   procured  by  parting     - 
do.   Paris  standard,  unannealed  - 
do.         do.  annealed 

Copper        -        .        _        _        . 
do.  ..... 

do.  ..... 

do.  ..... 

do.  -        .        -        .        _ 

Brass  ..... 

do.  -        -        .        .        _ 

do.  ..... 

Brass  scale,  supposed  from  Hamburg 
Cast  brass  -         -        -        .        . 
English  plate-brass,  in  rod    . 

do.  do. 

Brass  - 
Brass  wire  - 
Brass  - 

Copper  8,  tin  1 
Silver  . 
do.   . 
do.    . 
do. 
do. 
Silver 
Brass  16,  tin  1     - 
Speculum  metal   .  •        . 

Spelter  solder;  brass  2,  zinc  1 
Malacca  tin         .... 

Tin  from  Falmouth      ... 
Fine  pewter        .... 

Grain  tin    -        ...        . 

Tin 

Soft  solder ;  lead  2,  tin  1       - 
Zinc  8,  tin  1,  a  little  hammered    . 
Lead  ...... 

do.     -.--.. 
Zinc  --..-. 
Zinc,  hammered  out  ^  inch  per  foot 
Glass,  from  32°  to  212'' 
do.      from  212°  to  392°      . 
do.      from  392°  to  572°      - 


in  a  trough  form 


of  cupel     . 
Paris  standard 


Authority. 


Roy 

Phil.  Trans.  1795,  428 
Smeaton  ... 
Lavoisier  and  Laplace 
do.  do. 

do.  do. 

do.  do. 

do.  do. 

Troughton 
Smeaton  -        .        - 
Muschenbroek 

do. 
Borda      ... 
Smeaton  ... 
Lavoisier  and  Laplace 

do.  do. 

Troughton 
Dulong  and  Petit 
Smeaton  ... 
Muschenbroek 
EUicot,  by  comparison 
Lavoisier  and  Laplace 
do.  do. 

do.  do. 

Muschenbroek 
Lavoisier  and  Laplace 

do.  do. 

Troughton 
Dulong  and  Petit 
Borda       ... 
Lavoisier  and  Laplace 

do.  do. 

Roy 

Smeaton  ... 
Roy         ... 
do.  ... 

Troughton 

Smeaton  ... 
Muschenbroek 
Smeaton  ... 
Herbert    -         .        _ 
EUicot,  by  comparison 
Muschenbroek 
Lavoisier  and  Laplace 

do.  do. 

Troughton 

Smeaton  ... 
do.       ... 
do.       - 
Lavoisier  and  Laplace 

do.  do. 

Smeaton  ... 

do.      - 
Muschenbroek 
Smeaton  ... 

do.       . 
Lavoisier  and  Laplace 
Smeaton  .        .        - 
do.      - 
do. 
Dulons 
do. 
do. 


and  Petit 
do. 
do. 


Diiatatiuu 

in 
Decimals. 


1-00114470 

1-00112500 

1-00115000 

1-00107875 

1-00107956 

1-00136900 

100138600 

1-00123956 

1-00118980 

1-00122500 

1-00122000 

1-00137000 

1-00115600 

J -00125800 

1-00122045 

1-00123504 

1-00144010 

1-00118203 

1-00139200 

1-00146000 

1-00150000 

1-00146606 

1-00155155 

1-00151361 

10019100 

100172244 

1-00171222 

1-00191880 

1-00171821 

1-00178300 

1-00186871 

1-00188971 

1-00185540 

1-00187500 

1  00189280 

1-00189490 

1-00191880 

1-00193000 

1-00216000 

1-00181700 

1-00189000 

1-0021000 

1-00212000 

1-00190974 

1-00190868 

1-00-20826 

1-00190800 

1-00193300 

1-00205800 

1-00193765 

1-00217298 

1-00228300 

1-00248300 

1-00284000 

1-00250800 

1-00269200 

1-00284836 

1-00286700 

1  00294200 

1-00301100 

1-00086130 

1-00091827 

1-000101114 


The  last  two  measurements  by  an  air  thermometer. 


Dilatation 
in  Vulvar 
Fractions. 


92B 


jJt 


ffi« 


1 

6T5 
1 

_1 
SJ2 


1 

S^4 


1 


1 
JIT 


1 

ITeT 

losd 


i« 


IN 


666 


EXTRACTS. 

TABLE  n. 

Expansion  of  certain  Liquids  by  being  Heated  from  32?  <o  212". 


SulMtances. 

Authority. 

Expaniioa 

in 
Decimala. 

Expantin. 
in  Volgftr 
Fraction.. 

Mercury    -            -           -            - 
do.      in  glass   -            -            - 
Water,  from  its  maximum  density 
Muriatic  acid  (sp.  gr.  1-137) 
Nitric  acid  (sp.  gr.  1-40)   - 
Sulphuric  acid  (sp.  gr.  1-85) 
Alcohol  (to  its  boiling  point)  ? 
Water       -           -            -           - 
Water,  saturated  with  common  salt 
Sulphuric  ether  (to  its  boiling  point)  ? 
Fixed  oils              .            .             - 
Oil  of  turpentine    -            -            - 

Dulong  and  Petit     - 

do.              do. 
Kirwan 
Dalton 

do. 

do. 

do. 

do.              • 

do. 

do. 

do. 

do. 

0-01801800 

0-01543200 

0-04332 

00600 

0-1100 

0-0600 

0-1100 

00460 

00500 

00^-00 

0-0800 

00700 

h 

tV 

i 

1 

If  the  density  of  water  at  39°  be  called   - 
at  212°  it  becomes 
and  its  volume  has  increased  to 
at  77°  it  becomes    - 
and  its  volume  has  increased  to  only 


1-00000, 

0-9548, 

104734; 

0-9973587, 

1-00265, 


which,  though  one  fourth  of  the  whole  range  of  temperature,  is  only    i    of  the  to- 
tal expansion.    Water  at  60°  F.  has  a  specific  gravity  of  -        0-9991953, 

and  has  increased  in  volume  from  39°  to    -         1-00008, 
which  is  only  about  JL-  of  the  total  expansion  to  212°,  with  _i    of  the  total  range  of 
temperature. 

All  gases  expand  the  same  quantity  by  the  same  increase  of  temperature,  which  from 
32°  to  212^  Fahr.  =  1^°  =  f,  or  100  volumes  become  1-375.  For  each  degree  of  F«hr. 
the  expansion  is  t4-q. 

When  dry  air  is  saturated  with  moisture,  its  bulk  increases,  and  its  specific  gravity 
diminishes,  because  aqueous  vapor  is  less  dense  than  air,  at  like  temperatures. 

The  following  table  gives  the  multipliers  to  be  employed  for  converting  one  volume  of 
Hioist  gas  at  the  several  temperatures  into  a  volume  of  dry  gas. 


Temperature. 

Multiplier. 

Temperature. 

Multiplier. 

53°  F. 

0-9870 

64° 

0-9799 

54 

0-9864 

65 

0-9793 

55 

0-9858 

66 

0-9786 

56 

0-9852 

67 

0-9779 

57 

0-9846 

68 

0-9772 

58 

0-9839 

69 

0-9765 

59 

0-9833 

70 

0-9758 

60 

0-9827 

71 

0-9751 

61 

0-9820 

72 

0-9743 

62 

0-9813 

73 

0-9735 

63 

0-9806 

Ezpanaion  of  certain  Solidi. 


Brass    -  -  - 

Hammered  iron 

Carrara  marble 

Marble  of  St  Beat 

Marble  of  Saht 

Stone  of  Vernon  on  Seine 

Stone  of  St  Lew 

Stone  of  Veilvie  (volcanic) 

Alloy  of  D'Arcet 

Bismuth 


Absolute 
Dilatation. 


0-00187821 
000122043 
0-00084867 
0-00041810 
0-00056849 
0*00043027 
0-00064890 
000020390 
0-00169688 
0-00121034 


Dilatation  of  a 
Metre. 


1-8782 
1-2204 
0-8486 
0-4181 
0-6685 
0-4303 
0-6489 
0-2039 
1-6968 
1-2103 


FAINTS. 


667 


EXTRACTS.  {Extraits,  Fr. ;  Extracten,  Germ.)  The  older  apothecaries  used  thig 
term  to  designate  the  product  of  the  evaporation  of  any  vegetable  juice,  infusion,  or 
decoction ;  whether  the  latter  two  were  made  with  water,  alcohol,  or  ether ;  whence 
arose  the  distinction  of  aqueous,  alcoholic,  and  etherous  extracts. 

Fourcroy  made  many  researches  upon  these  preparations,  and  supposed  that  they 
had  all  a  common  basis^  which  he  called  the  extractive  pnnciple.  But  Chevreul  and 
other  chemists  have  since  proved  that  this  pretended  principle  is  a  heterogeneous  and 
very  variable  compound.  By  the  term  extract  therefore  is  now  meant  merely  the 
whole  of  the  soluble  matters  obtained  from  vegetables,  reduced  by  careful  evaporation 
to  either  a  pasty  or  solid  consistence.  The  watery  extracts,  which  are  those  most  com- 
monlv  made,  are  as  various  as  the  vegetables  which  yield  them ;  some  containing 
chiefly  sugar  or  gum  in  great  abundance,  and  are  therefore  innocent  or  inert;  while 
others  contain  very  energetic  impregnations.  The  conduct  of  the  evaporating  heat  is 
tlie  capital  point  in  the  preparation  of  extracts.  They  should  be  always  prepared  if 
possible  from  the  juice  of  the  fresh  plant,  by  subjecting  its  leaves  or  other  succulent 
part,  to  the  action  of  a  powerful  screw  or  hydraulic  press;  and  the  evaporation  should 
be  effected  by  the  warmth  of  a  water  bath,  heated  not  beyond  100*^  or  120*^  F.  Steam 
heat  may  perhaps  be  applied  advantageously  in  some  cases,  where  it  is  not  likely  to  de- 
compose any  of  the  principles  of  the  plant  But  by  far  the  best  process  for  making 
extracts  is  in  vacuo,  upon  the  principles  explained  in  the  article  Evaporation.  It  is 
much  easier  to  fit  up  a  proper  apparatus  of  this  kind,  than  most  practical  men  imagine. 
The  vacuum  may  either  be  made  through  the  agency  of  steam,  as  there  pointed  out»  or 
by  means  of  an  air-pump.  One  powerful  air-pump  may  form  and  maintain  a  good 
vacuum  under  several  receivers,  placed  upon  the  flat-ground  flanges  of  so  many  basins, 
each  provided  with  a  stop-cock  at  its  side  for  exhaustion.  The  air-less  basin  containing 
the  juice  being  set  on  the  shelf  of  a  water-bath,  and  exposed  to  a  proper  temperature, 
will  furnish  in  a  short  time  a  large  quantity  of  medicinal  extract,  possessing  the 
properties  of  the  plant  unimpaired. 

For  exceedingly  delicate  purposes,  the  concentration  may  be  performed  in  the  cold, 
by  placing  saucers  filled  with  the  expressed  juice  over  a  basin  containing  sulphuric 
acid,  putting  a  glass  receiver  over  them,  and  exhausting  its  air. 

These  preparations  of  vegetables  for  medicinal  use  are  made  either  by  evaporating  the 
infusions  of  the  dried  plant  in  water,  or  in  alcohol,  or  the  expressed  juice  of  the  fresh 
plant ;  and  this  evaporation  may  be  effected  by  a  naked  fire,  a  sand  bath,  an  air  bath,  a 
steam  heat,  or  a  liquid  balneum  of  any  nature,  all  of  which  may  be  carried  on  eitlier  in 
the  open  air,  or  in  vacuo.  Of  late  years,  since  the  vacuum-pan  has  been  so  successfully 
employed  in  concentrating  syrups  in  sugar-housea,  the  same  system  has  been  adopted  for 
making  pharmaceutical  extracts.  An  elegant  apparatus  of  this  kind  invented  by  Mr. 
Barry,  of  Plough  Court,  was  made  the  subject  of  a  patent  about  35  years  ago.  The 
use  of  the  air-pump  for  evaporating  such  chemical  substances  as  are  readily  injured  by 
heat,  has  been  very  common  since  Professor  Leslie's  discovery  of  the  eflSeacy  of  the  com- 
bined influence  of  rarified  air  and  an  absorbing  surface  of  sulphuric  acid  in  evaporating 
water  at  low  temperatures.  It  has  been  supposed  that  the  virtues  of  narcotic  plants  in 
particular  might  be  better  obtained  and  preserved  by  evaporation  in  vacuo  than  other- 
wise, as  the  decomposing  agency  of  heat  and  atmospheric  oxygen  would  be  thereby  ex- 
cluded. There  is  no  doubt  that  extracts  thus  made  from  the  expressed  juices  of  fresh 
vegetables  possess,  for  some  time  at  least,  the  green  aspect  and  odor  of  the  plants  in 
far  greater  perfection  than  those  usually  made  in  the  air,  with  the  aid  of  artificial  heat 
Dr.  Meurer,  in  the  Archiv.  der  Pharmacie  for  April,  1843,  has  endeavored  to  show  that 
the  color  and  odor  are  of  no  use  in  determining  the  value  of  extracts  of  narcotics^ 
that  the  albumen  left  unchanged  in  the  extracts  made  in  vacuo  tends  to  cause  their 
spontaneous  decomposition,  and  that  the  extracts  made  with  the  aid  of  alcohol,  as  is 
the  practice  in  Germany,  are  more  eflficacious  at  first,  and  much  less  apt  to  be  injured 
by  keeping.  M.  Baldenius  has,  in  the  same  number  of  the  Archiv.,  detailed  experi- 
ments to  prove  that  the  juices  of  recent  plants  mixed  with  alcohol,  in  the  homoeopathic 
fashion,  are  very  liable  to  spontaneous  decomposition.  To  the  above  expressed  juice, 
the  Germans  add  the  alcoholic  tincture  of  the  residuary  vegetable  matter,  and  evapora- 
ting both  together,  with  filtration,  prepare  very  powerful  extracts. 


I 


F. 

FAHLERZ.     Gray  copper-ore,  called  also  Panabase,  from  the  many  oxides  it  con- 
tains. 

FAINTS  is  the  name  of  the  impure  spirit  which  comes  over  first  and  last  in  the 


fii 


II 


II 


f  I 


f 


668 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


distillation  of  whiskey ;  the  former  being  called  the  strong,  and  the  latter,  which  is  nriuch 
more  abundant,  the  weak  faints.  This  crude  spirit  is  much  impregnated  with  foetid 
essential  oil,  is  therefore  very  unwholesome,  and  must  be  purified  by  rectifications. 

FAIRBAIRN'S  TUBULAR  BRIDGES.  Of  the  tubular  bridge  system,  the  Con- 
way  and  Menai  are  the  first,  and  will  probably  for  ever  remain  the  most  remarkable 
specimens,  to  attest  the  scientific  genius  of  Mr.  W.  Fairbairn,  their  inventor  and  con- 
structor. His  claims,  indeed,  are  exclusive  and  palpable.  Mr.  Robert  Stephenson,  how- 
ever, has  fortunately  for  himself,  claimed  the  entire  merit  of  having  not  only  first 
conceived  the  idea  of  constructing  a  tubular  bridge  of  such  huge  dimensions  as  to 
allow  the  passage  of  locomotive  engines  and  railway  trains  through  the  interior  of  it^ 
and  of  such  length  as  to  span  distances  of  from  400  to  500  feet,  but  of  having  assured 
himself  by  laborious  investigation  and  calculation  of  "the  perfect  feasibility  of  the 
work,"  without  consulting  any  one  else  on  the  subject;  and  he  has  assigned  to  Mr. 
Fairbairn,  in  a  very  slighting  fashion  the  place  of  a  mere  after  adviser,  of  one  who, 
in  common  with  two  other  gentlemen  (Mr.  Eaton  Hodgkinson  and  Mr.  Edv/in 
Clarke),  but  not  more  than  either  of  them,  assisted  him  in  working  out  the  construction 
which  he  "first  broached."  Mr.  Fairbairn  maintains,  on  the  contrary,  that  the  idea 
of  a  tubular  bridge,  though  it  unquestionably  originated  with  Mr.  Stephenson,  was 
in  his  hands  nothing  more  than  a  crude  conception,  very  hesitatingly  entertained,  until 
he  (Mr.  Fairbairn)  was  called  in  to  work  it  out,  and  that  it  has  been  wholly  owing  to 
his  determined  perseverance  in  the  execution  of  the  task  confided  to  him,  and  to  his 
numerous  and  elaborate  experiments^  that  "  the  true  principle  on  which  tubular  bridges 
should  be  constructed  has  been  established,  and  thereby  Mr.  Stephenson's  vague  idea 
successfully  carried  into  execution." 

"At  the  period  of  the  consultation  in  April,  1845,  there  were  no  drawings  illustrative 
of  the  original  idea  of  the  bridge,  nor  had  any  calculations  been  made  as  to  the  strength, 
form,  or  proportions  of  the  tube.  I  was  asked  whether  such  a  design  was  practicable, 
and  whether  I  could  accomplish  it:  it  was  ultimately  arranged  that  the  subject  should 
be  investigated  experimentally,  to  determine  not  only  the  value  of  Mr.  Stephenson's 
original  conception,  but  that  of  any  other  tubular  form  of  bridge  which  might  present 
itself  in  the  prosecution  of  my  researches.  The  matter  was  placed  unreservedly  in  my 
hands;  the  entire  conduct  of  the  investigation  was  intrusted  to  me ;  and,  as  an  experi- 
menter, I  was  to  be  left  free  to  exercise  my  own  discretion  in  the  investigation  of 
whatever  forms  or  conditions  of  the  structure  might  appear  to  me  best  calculated  to 
secure  a  safe  passage  across  the  Straits."    (  W.  Fairhaim's  Correspondence.) 

In  commenting  on  the  treatise  of  Mr.  Fairbairn  "on  the  Construction  of  the 
Britannia  and  Conway  Bridges,"  the  editor  of  the  Mechanics'  Magazine  says,  "We 
have  read  it  carefully,  and  not  without  strong  prepossessions  in  favor  of  the  inculpated 
party,  but  we  feel  honestly  bound,  however,  to  say,  that  the  perusal  has  left  ns  con- 
vinced, in  spite  of  all  leanings,  that  Mr.  Fairbairn  has  not  received  at  Mr.  Stephenson's 
hands  that  justice  to  which  he  was  entitled,  but,  on  the  contrary,  has  been  treated  most 
ungenerously  and  ungratefully.  We  will  not  say,  that  but  for  Mr.  Fairbairn  the 
tubular  bridge  idea  would  never  have  been  carried  out  into  practice,  for  that  would 
be  to  assume  that  he  engrossed  in  his  single  person  all  the  practical  skill  of  the 
country ;  but,  looking  into  the  facts  of  the  case  as  they  stand,  and  as  we  see  them 
established  in  the  volume  before  us  beyond  all  possibility  of  dispute,  we  hesitate  not 
to  affirm,  that  it  is  more  owing  to  Mr.  Fairbairn,  than  to  any  one  other  individual 
whatever,  not  excepting  Mr.  Stephenson  himself,  that  it  is  now  the  triumphant  reality 
which  it  ia.  Another  might  possibly  have  done  the  part  which  fell  to  the  lot  of 
Mr.  Fairbairn  as  well,  but  none  could  possibly  have  done  it  better.  He  conceived 
and  directed  all  the  preliminary  experiments, — all  at  least  with  an  exception  or  two, 
which  were  of  any  practical  value,  exhibiting  therein  a  combination  of  }>hilo8ophical 
painstaking  with  mechanical  skill  and  ingenuity,  such  as  is  not  often  witnessed ;  he 
finally  settled  the  form  which  it  was  best  to  give  to  the  tube,  and  ai-ranged  the 
whole  of  the  executive  details;  he  personally  superintended  the  construction  of  the 
Conway  Bridge,  which  our  readers  are  aware  is  but  the  Menai  or  Britannia  Bridge 
on  a  smaller  scale;  and  he  only  retired  from  further  co-operation  with  Mr.  Stephenson 
in  the  affair,  when  nothing  new  was  left  to  be  discovered  or  achieved.  The  motives 
for  his  retirement  are  thus  very  fairly  and  temperately  stated  : — 

"  1 1  have  now  brought  down  this  correspondence  to  the  period  when  my  oflScial  con- 
nection with  the  Chester  and  Holyhead  Railway  Company  as  engineer,  for  the  con- 
struction of  the  tubular  bridges,  may  be  said  to  have  virtually  ceased,  and  I  should 
willingly  have  passed  over  in  silence  the  remainder  of  the  events  which  transpired,  were 
it  not  that  the  completeness  of  the  narrative,  as  well  as  the  justification  of  my  conduct, 
demanded  some  explanation,  independently  of  the  regret  which  I  experienced  in  with- 
drawing from  an  undertaking  to  which  I  had  devoted  so  much  time  and  thought^ — an 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


669 


undertaking  fraught  with  the  greatest  interest,  and  which  had,  as  it  were,  grown  up  in 
all  its  magnificent  proportions  under  my  own  directions.  I  can  truly  say  that  the  dis- 
agreement which  took  place  with  Mr.  Stephenson  is  on  my  part  much  deplored.  But  I 
trust  that  the  reader  of  the  foregoing  pages  will  at  least  have  arrived  at  the  conclusion, 
that  I  had  taken  the  most  important  part  in  developing,  and  giving  a  practical  form 
to  Mr.  Stephenson's  idea,  and  also  in  the  superintending  the  construction  and  erectioQ 
of  the  first  Conway  tube.  The  fact  is,  I  labored  almost  incessantly  in  devising  plans, 
or  in  watching  over  the  practical  details  of  the  work,  from  the  day  in  which  Mr. 
Stephenson's  suggestion  was  communicated  to  me  until  the  close  of  my  engagement; 
and  I  can  sincerely  say  that  I  was  always  actuated  by  the  principle  of  leaving  nothing 
undone  which  could  in  any  way  contribute  to  the  successful  accomplishment  of  the 
undertaking.  Regardless  of  the  prognostications  of  failure  with  which  the  scheme  was 
assailed,  and  in  despite  of  the  opposition  of  those  whose  assistance  I  had  solicited,  I 
uniformly  advocated  the  peculiar  principle  on  which  the  Conway  Bridge  has  been  con- 
structed.      • 

"  *Such  being  my  position,  and  viewing  the  extent  of  services  I  had  rendered,  it  will,  I 
think,  be  generally  allowed  that  it  was  very  natural  that  I  should  desire  to  have  my 
name  publicly  associ^ited  with  Mr.  Stephenson's  as  joint  engineer  for  these  bridges. 
Indeed,  it  may  very  fairly  be  said  that  I  might  have  ventured  to  claim  this  distinction, 
since  it  had  been  conferred  upon  me  by  the  Board  of  Directors  on  Mr.  Stephenson's  own 
recommendation.  If,  instead  of  success  having  crowned  our  efforts,  failure  had  im- 
fortunately  ensued,  would  not  my  reputation  have  suffered  as  well  as  Mr.  Stephenson's? 
The  working  plans  having  gone  forth  with  my  name  alone  attached  to  them,  and  from 
my  being  recognised  as  the  acting  engineer,  might  not  the  whole  blame  have  been  con- 
veniently thrown  on  me  in  case  of  failure? 

"  *It  was  not,  however,  on  any  of  these  grounds  that  I  was  induced  to  resign  mv 
appointment,  for  there  had  not  then  occurred  any  opportunity  where  I  conceived  it 
necessary  to  have  my  position  publicly  recognised ;  and  I  had  always  believed  that, 
when  the  proper  time  came,  Mr.  Stephenson  would  be  the  first  to  establish  that  position, 
and  acknowledge  the  services  I  had  rendered.  The  recognition  was,  however,  very 
shortly  afterwards  denied  me.  The  first  Conway  tube  having  been  completed,  and  the 
success  of  the  principle  established,  I  conceived  that  the  construction  of  the  remaining 
tubes  simply  required  a  close  attention  to  the  system  of  construction  already  adopted, 
and  therefore  might  safely  be  entrusted  to  those  gentlemen  whose  constant  presence 
during  the  building  of  the  first  tube  had  rendered  them  thoroughly  acquainted  with  the 
whole  details  of  the  work.  By  such  an  arrangement,  moreover,  the  Company  would  save 
the  amount  which  had  hitherto  been  paid  for  my  services,  and  I  should  be  enabled  to 
devote  my  time  to  other  pursuits  which  I  had  neglected  for  this  work,  and  which  now 
urgently  demanded  my  attention.  This  was  one  reason  for  my  retirement ;  but  what 
chiefly  led  me  to  this  decision,  was  the  position  assumed  by  Mr.  Stephenson,  his  public 
misrepresentation  of  the  position  I  held  under  the  Company,  and  his  endeavor  to 
recognise  my  services  as  the  labors  of  an  assistant  under  his  control,  and  acting  entirely 
under  his  direction.  Had  Mr.  Stephenson  in  his  public  address  done  me  the  justice  to 
state  my  independent  claim  to  some  of  the  most  important  principles  observed  in  the 
construction  of  the  tubes,  I  might,  perhaps,  have  continued  my  services  until  the  final 
completion  of  the  whole  undertaking;  and,  most  assuredly,  this  work  would  never  have 
come  before  the  public.  I  now  appeal  to  the  preceding  pages  of  this  narrative, 
whether  Mr.  Stephenson's  assertions  are  borne  out  by  the  simple  statement  of  facts? 
I  have  overstated  nothing,  concealed  nothing;  and  the  reader  is  left  to  draw  his  own 
conclusions  from  these  facts,  after  having  become  acquainted  with  the  course  pursued 
by  Mr.  Stephenson,  which  I  will  in  conclusion  concisely  relate.'  (p.  111.) 

"  Mr.  Fairbairn  proceeds  then  to  give  an  account  of  a  public  dinner  to  celebrate  the 
completion  of  the  Conway  Bridge,  which  took  place  on  the  17th  of  May,  1848;  on 
which  occasion  it  was,  Mr.  Stephenson  first  openly  assumed  that  position  in  regard  to  Mr. 
Fairbairn  and  the  undertaking,  which  has  made  the  present  appeal  to  public  justice 
necessary.  Mr.  Stephenson's  speech  was  confessedly  a  studied  affair— he  had  announced 
beforehand  that  he  would  avail  himself  of  the  opportunity  of  'setting  the  question  at 
rest;*  but  for  all  that  it  does  not  take  Mr.  Fairbairn  many  words  to  demolish  it 
utterly. 

•  ♦  The  inaccuracies,  both  as  to  facts  and  dates,  in  the  statements  of  Mr.  Stephenson, 
are  very  numerous.  It  simply  requires  a  reference  to  the  short  description  of  the 
Ware  Bridge,  and  to  the  drawings,  to  disprove  the  assertion,  that  it  is  a  thin  tubular 
bridge,  although  not  precisely  the  same  as  the  present,  yet  in  principle  precisely  the 
same ;  and  it  can  easily  be  shown  too,  that  considering  the  Ware  Bridge  as  a  simple 
girder  bridge,  it  is  exceedingly  defective  in  design.  Is  there  anything  new  in  this  ap- 
plication of  wrought-iron  plate  girders?   As  well  might  it  be  said  that  the  combinatioQ 


670 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


of  wroiight-iron  deck  beams,  8o  many  years  applied  in  iron  ships  for  the  support  of  the 
decks,  is  a  "  counterpart  of  the  proposed  cellular  top  for  the  Britannia  tubes."  I  really 
caoDot  but  regret  that  Mr,  Stephenson,  whose  name  will  be  always  associated  with  the 
grandest  bridge  that  has  ever  been  constructed,  should  have  committed  himself  in 
making  such  an  erroneous  assertion  as  that  it  was  by  reviving  and  extending  his  original 
conception  of  this  imperfect  structure  at  Ware,  that  he  was  led  to  originate  the  bridges 
crossing  the  Conway  and  Menai  Straits. 

"*Mr.  Stephenson's  remarks  further  admit  of  the  disingenuous  construction  that  his 
scheme  was  matured  before  the  Bill  for  the  Chester  and  Holyhead  Railway  was  passed 
by  Parliament,  and  before  I  was  consulted,  and  that  he  was  at  that  early  period  ac- 
quainted with  the  present  design  of  the  bridge.  He  refers  to  the  incredulous  glances 
which  were  directed  towards  him  when  the  description  of  the  bridge  was  explained  to 
the  Committee ;  and  intimates,  "  that  it  was  not  until  the  Bill  had  been  obtained,  and  it 
became  necessary  to  commence,  that  he  requested  my  assistance."  Now,  my  advice  was 
asked  by  Mr.  Stephenson  before  his  evidence  to  the  Parliamentary  Committee  was  given, 
and  he  announced  his  idea  to  that  Committee  strengthened  by  more  than  one  opinion  of 
its  feasibility.  Let  the  reader  turn  again  to  the  earlier  letters  of  the  correspondence,  and 
he  will  find  of  what  a  crude  and  dangerous  scheme  that  idea  consisted ;  how  totally 
dissimilar  in  form  and  principle  it  was  to  the  present  tubular  structures,  and  how 
slowly  Mr.  Stephenson  was  persuaded  to  give  up  his  earliest  conceptions.  Again  ;  Mr. 
Stephenson  states  that  he  called  in  the  aid  of  Mr.  Hodgkinson  and  myself  at  the 
same  time;  now  it  is  essential  to  the  proof  of  my  claims  that  this  assertion  should  be 
explicitly  contradicted.  It  was  I,  and  not  Mr.  Stephenson,  who  solicited  Mr.  Hodg- 
kinson's  co-operation,  and  this  was  not  done  until  I  had  been  actively  engaged  for 
several  months  in  my  experimental  researches,  and  after  I  had  discovered  the  principle 
of  strength  which  was  offered  in  the  cellular  top,  and  not  only  proved  the  impractica- 
bility of  Mr.  Stephenson's  original  conception,  but  had  given  the  outline  of  that  form 
of  tube  which  was  ultimately  carried  into  execution. 

"'When  Mr.  Stephenson  had  made  up  his  mind  to  claim  in  the  manner  he  did  the 
whole  merit  of  the  undertaking,  it  is  noti  difficult  to  understand  his  reason  for  giving 
Mr.  Clarke,  his  own  assistant,  so  prominent  a  position.  I  willingly  bear  my  testimony 
to  the  great  value  of  the  services  rendered  by  Mr.  Clarke,  to  his  talents,  and  to  the 
great  energy  which  he  displayed  in  working  out  his  several  duties,  but  these  had  no 
reference  whatever  to  the  designing  of  the  structures.'  (p.  178.) 

"  There  is  one  part  of  the  case  on  which  we  think  Mr.  Fairbairn  does  not  insist  enough, 
thougli,  in  our  judgment,  it  is  of  itself  decisive  of  the  inordinateness  of  Mr.  Stephenson's 
pretensions.  Mr.  Stephenson  and  his  friends,  for  obvious  reasons,  slur  it  over  alto- 
gether. We  refer  to  Mr.  Fairbairn's  appointment  to  be  joint  engineer  along  with  Mr. 
Stephenson  to  the  Conway  and  Britannia  Bridges.  The  evidence  of  this  is  a  Minute 
of  the  Board  of  Directors  of  the  Chester  and  Holyhead  Railway,  dated  13th  May,  1846, 
which  we  here  quote  at  length  from  the  work  before  us. 

"'Resolved — Ist  That  Mr.  Fairbairn  be  appointed  to  superintend  the  construction 
and  erection  of  the  Conway  and  Britannia  Bridges,  in  conjunction  with  Mr.  Stephenson. 

"'2d.  That  Mr.  Fairbairn  have,  with  Mr.  Stephenson,  the  appointment  of  such 
persons  as  are  necessary,  subject  to  the  powers  of  their  dismissal  by  the  Directors. 

"'3d.  That  Mr.  Fairbairn  furnish  a  list  of  the  persons  he  requires,  with  the  salaries 
he  proposes  for  all  foremen  or  others  above  the  class  of  workmen. 

"'4th.  That  advances  of  money  be  made  on  Mr.  Fairbairn's  requisition  and  certi- 
ficates, which,  with  the  accounts,  or  vouchers,  are  to  be  furnished  monthly. 

"  '5th.  That  the  Directors  appoint  a  bookkeeper  at  each  spot,  the  Conway  and  the 
Menai.' 

"To  talk,  after  this,  of  Mr.  Fairbairn's  being  only  entitled  to  a  secondary  and  subor- 
dinate place  in  the  affair,  is  to  outrage  all  truth  and  propriety. 

"  We  can  but  regard  with  profound  pity  the  hallucination  which  has  betrayed  a  man 
of  Mr.  Stephenson's  genius  and  worth  (this  unfortunate  episode  notwithstanding)  into 
so  false  a  position. 

"  We  do  not  overlook  that  we  have  as  yet  Mr.  Fairbairn's  statement  of  the  case  only, 
and  that  we  may  expect  to  see,  ere  long,  sometliing  of  a  very  opposite  complexion  from 
Mr  Stephenson  or  some  of  his  friends.  We  shall  give  all  due  consideration  to  any  such 
counter-statement  when  it  comes  before  us;  but  so  well  is  all  Mr.  Fairbairn  says  borne 
out  by  written,  and  therefore  unalterable  proofs,  that  we  do  not,  in  the  meanwhile, 
hesitate  to  avow  our  firm  belief  that  nothing  which  can  possibly  be  adduced  in  the 
way  of  either  evidence  or  argument,  can  ever  alter  materially  the  conclusion  at  which 
we  have  already  arrived." — Mechanic's  Magazine.) 

Fairbairn's  Tubular  Girder  Bridges. — William  Fairbairn,  Esq.,  of  Manchester, 
F.  R.  S.,  and  Member  of  the  Institute  of  France,  has  been  long  recognised  as  the  most 
accomplished  of  our  factory  engineers  and  the  most  skilful  of  our  millwrights,  by  his 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


671 


admirable  fire-proof  buildings  and  his  magnificent  hydraulic  machines.  Having  a  few 
years  ago  directed  his  constructive  genius  to  the  building  of  iron  steam-ships,  he 
became  thereby  well  acquainted  with  the  prodigious  stiffness  and  strength  of  which 
hollow  girders  of  thin  sheet  iron  were  susceptible.  He  was  naturally  pitched  upon  by 
Mr.  Stephenson,  the  engineer  of  the  Chester  and  Holyhead  Railway,  as  the  fittest  per- 
son to  execute  the  tubular  bridge  which  was  regarded  by  him  as  the  only  means  of 
carrying  ponderous  railway  trains  over  the  tremendous  sea-gulf  of  Menai's  Straits  or 
Conway's  roaring  flood.  The  tidal  torrents  of  these  two  places  being  deep  and  rapid, 
required  to  be  crossed  by  bridges  of  extraordinary  span  and  strength.  No  centrings 
or  other  substructures  usually  resorted  to  for  mounting  such  huge  pontitectures  could 
be  erected.  In  such  a  dilemma,  the  most  obvious  resource  of  the  engineer  was  a  sus- 
pension bridge;  but  the  failure  of  more  than  one  attempt  of  that  kind  had  proved  the 
impossibility  of  running  railway  trains  over  such  bridges  with  safety. 

Under  Mr.  Stephenson's  direction,  numerous  other  schemes  had  been  devised.  Both 
timber  and  cast-iron  arches  had  been  thought  of;  and  a  model  of  a  very  handsome 
bridge  for  crossing  the  Menai  Straits  on  the  latter  principle  had  been  constructed,  and 
submitted  to  the  consideration  of  a  parliamentary  committee.  The  possibility  of 
throwing  cast-iron  arches  over  so  great  a  span  as  450  ft  was  however  questionable ; 
and  the  security  of  such  a  bridge  must  have  been  endangered  by  the  great  changes 
which  the  material  would  have  been  subjected  to  from  atmospheric  influences,  and  from 
vibrations  produced  by  the  passage  of  heavy  trains.  But  a  more  important  objection 
even  than  these  caused  the  withdrawal  of  this  design.  The  Lords  Commissioners  of  the 
Admiralty,  as  conservator  qf  the  navigation,  opposed  the  erection  of  any  structure 
which  should  offer  a  hindrance  to  the  free  passage  of  vessels  under  it,  and  insisted  on  a 
clear  headway  of  105  ft  from  the  level  of  high  water.  Mr.  Stephenstm  then  conceived 
the  original  idea  of  a  huge  tubular  bridge,  to  be  constructed  of  riveted  plates,  and  sup- 
ported by  chains,*  and  of  such  dimensions  as  to  allow  of  the  passage  of  locomotive 
engines  and  railway  trains  through  the  interior  of  it  The  illustrious  Galileo,  in  de- 
monstrating the  strength  of  tubular  structures,  adverted  to  the  quills  of  birds  and  the 
stalks  of  corn  ;  but  in  our  days  we  see  that  idea  amplified  into  colossal  dimensions. 
«i  Y/^  ^'^'*  reference  to  this  expedient,  after  all  others  had  been  found  inapplicable, 
that  Mr.  Fairbairn  was  consulted  by  him,  and  requested  to  give  his  opinion— first,  as 
to  the  practicability  of  the  scheme  ;  and  secondly,  as  to  the  means  necessary  for  carrr- 
mg  It  out  The  consultation  took  place  early  in  April,  1845.  Mr.  Stephenson  con- 
ceived that  the  tube  should  be  either  of  a  circular  or  egg-shaped  sectional  form ;  and 
he  was  strongly  impressed  with  the  primary  importance  of  the  use  of  chains,  placing  his 
reliance  in  them  as  the  principal  support  of  the  bridge.  He  never  for  a  moment  enter- 
tained the  idea  of  making  the  tube  self-supporting.  The  wrought-iron  tube,  according 
to  his  Idea,  was  indeed  entirely  subservient  to  the  chains,  and  intended  to  operate  from 
Its  rigidity  and  weight  as  a  stiffener,  and  to  prevent,  or  at  least  to  some  extent  coun- 
teract, the  catenary  principle  of  construction. 

"  February  23d,  1846. 
**  My  dear  Sir, 

"I  have  been  considering  the  principle  on  which  you  purpose  attaching  the  chain 
for  the  support  of  the  tube;  and  with  every  deference  to  your  judgment,  1  am  almost 
inclined  to  differ  with  you  upon  that  point 

"It  appears  to  me  that  the  great  and  important  consideration  is  to  relieve  the  strain 
upon  the  tube.  It  is  quite  clear  that  a  series  of  chains  on  each  side  of  the  plates,  well 
fitted  and  tightly  screwed  up,  would  tend  to  stiffen  the  sides,  and  give  greater  rigidity 
to  these  parts.  This  is,  however,  not  what  is  wanted.  The  rigidity  is  required  on  the 
top  side;  as  in  all  the  experiments  the  sides  seldom  get  out  of  form  unless  distorted  by 
the  crushing  of  the  top  side.  Under  these  circumstances  the  stiffening  should  in  my 
opinion  be  on  the  top  platform  of  the  tube"— William  Fairbairn  to  Mr.  Robert  Ste- 
phenson.^ 

For  many  months  afterwards,  and  even  up  to  the  time  of  the  experiments  on  the 
model  tube  in  December  1846,  Mr.  Stephenson  insisted  on  the  application  of  such 
chains.  "  I  always  felt,"  says  Mr.  Fairbairn,  "that  in  a  combination  of  two  bodies, 
the  one  of  a  perfectly  rigid,  and  the  other  of  a  flexible  nature,  there  was  a  principle  of 
weakness;  for  the  vibrations  to  which  the  one  would  be  subjected,  would  call  into 
operation  forces  whose  constant  action  upon  the  rivets  and  fastenings  of  the  other  could 
not  but  tend  to  loosen  them,  and  thus,  by  a  slow  but  sure  agency,  to  break  up  the 
bridge.** 

In  consequence  of  the  favorable  opinion  entertained  by  Mr.  Stephenson  on  the  cylin- 

♦  These  chains,  not  only  superfluotis  hut  dangerous,  would  have  cost  150.0001 
t  Conway  and  Menai  Bridges,  by  W,  Fairbairn,  C.  E.,  p.  48. 

43 


672 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


673 


II 


drical  tubes,  it  was  deemed  expedient  to  commence  experiments  upon  models  of  that 
kind,  and  to  extend  them  subsequently  to  elliptical  tubes.  Experiments  carefully 
made,  demonstrated  the  weakness  of  the'se  two  forms,  and  the  vastly  greater  strength  of 
the  rectangular  tubes,  which  were  accordingly  adopted  with  cellular  top  and  bottom. 

In  Mr.  Stephenson's  examination  before  the  Select  Committee  of  Railways  of  the 
House  of  Commons,  5th  and  6th  of  May,  1845,  he  says:  "I  am  instituting  a  series  of 
experiments  in  conjunction  with  Mr.  Fairbairn  of  Manchester,  who  is  already  in  pos- 
session of  experiments  on  iron  ships,  which  place  the  thing  beyond  all  doubt  He  has 
ascertained  that  a  vessel  of  250  ft  in  length  supported  at  the  ends  will  not  yield  with 
all  tlie  machinery  in  the  middle. 

"Have  your  calculations  been  submitted  to  any  other  engineers? 

"  /  have  made  them,  in  conjunction  with  Mr.  Fairbairn  of  Manchester,  whose  experience 
is  greater  than  any  other  man's  in  England.  There  is  an  iron  vessel  now  building  by  Mr. 
Fairbairn  220  ft  in  length;  and  he  says  that  he  will  engage,  that,  when  it  is  finished, 
it  shall  be  }>ut  down  on  the  stocks  at  each  end,  and  shall  have  1000  tons  of  machinery 
in  the  middle  of  it  and  it  will  not  affect  it  But  that  is  not  so  strong  as  a  tube,  and 
therefore,  any  experiment  that  this  would  carry  out,  the  tube  would  fully  bear." 

The  floating  ofthejirst  Conway  tube — "The  transport  of  a  huge  mass  of  iron  412  ft 
long,  26  ft  6  in.  high,  15  ft  wide,  and  weighing  not  less  than  1300  tons,  was  a  task  of 
no  ordinary  difficulty.  No  former  effort  with  which  we  are  acquainted  can,  I  think,  be 
said  to  have  equalled  it,  when  the  unwieldiness  of  its  form,  and  the  extraordinary  natural 
difficulties  to  be  encountered,  are  taken  into  consideration.  Many  of  the  works  of  the 
ancients  are  stupendous  in  conception  and  colossal  in  dimensions ;  and  it  has  been  a 
constant  matter  of  inquiry,  in  what  manner  a  people,  ignorant  of  the  mechanical  ap- 
pliances which  we  possess,  could  raise  structures  which  have  resisted  all  the  inroads  of 
time,  and  which  are  to  the  present  generation  objects  of  awe  and  admiration.  In  more 
recent  times,  the  transport  of  the  immense  granite  block  which  forms  the  base  of  the 
statue  of  Peter  the  Great  at  St  Petersburg,  was  looked  upon  as  a  most  extraordinary 
achievement ;  but  it  cannot  he  said  to  have  been  so  formidable  an  undertaking  as  the 
moving  of  the  Conway  tube.  The  granite  block  was  a  compact  mass,  being  42  ft  at 
the  base,  21  ft  thick,  and  17  ft  high,  and  capable  of  being  moved  on  rollers,  Ac,  to  the 
raft  which  carried  it  down  the  Neva  to  the  site  of  the  city;  but  in  the  case  of  the  Con- 
way tube,  after  the  most  anxious  consideration,  and  when  numerous  schemes  and  pro- 
posals had  been  weighed,  examined,  and  rejected,  that  of  floating  the  mass  on  pontoons 
or  barges  was  decided  upon  as  the  most  feasible  and  most  secure,  the  centre  of  gravity 
being  in  this  case,  necessarily  raised  several  feet  In  addition  to  this  disadvantage,  the 
whole  had  to  be  handled  and  manoiuvred  in  probably  the  most  difficult  tideway  in 
Europe,  where  the  current  rushes  through  a  narrow  gorge  of  great  depth  to  fill  the 
broad  expanse  of  the  inland  bay,  at  a  rate  of  6  or  7  miles  an  hour ;  and  the  utmost 
nicety  had  moreover  to  be  observed  in  bringing  the  tube  to  its  place,  as  there  was  only 
a  clearance  of  12  inches;  that  is,  the  distance  between  the  opposite  masses  of  masonry 
was  only  12  inches  greater  than  the  length  of  the  tube.  All  these  obstacles  may  well 
be  termed  formidable;  and  I  therefore  conceive  that  the  utmost  praise  is  due  to  Mr. 
Stephenson  for  the  admirable  arrangements  and  contrivances  which  rendered  the  first 
attempt  at  so  gigantic  an  operation  perfectly  successful" 

I  have  quoted  these  liberal  remarks  of  Mr.  Fairbairn  in  proof  of  his  good  feeling  to- 
wards the  engineer  associated  with  him  conformably  to  the  Minute  of  the  directors  of 
the  Chester  and  Holyhead  Railway,  of  date  May  13,  1846,  already  quoted. 

How  defective,  and  even  erroneous,  Mr.  Stephenson's  conceptions  were  of  the  tubular 
girder  construction  so  late  as  the  26th  October,  1846,  appears,  from  his  stating  in  a 
letter  of  that  date  addressed  to  Mr.  Fairbairn,  "that  this  was  not  the  first  time  he  had 
the  idea  of  employing  wrought-iron  tubular  bridges;  for  three  years  ago,  or  there- 
abouts, I  had  erected  at  Ware,  on  the  Northern  and  Eastern  Railway,  a  cellular  plat- 
form of  wrought-iron.  It  was,  in  fact  I  believe,  a  counterpart  of  the  proposed  top  of 
the  Britannia  bridge."  r    r  r 

"As  this  statement,"  says  Mr.  Fairbairn,  "has  been  frequently  repeated  since  the 
letter  was  written,  I  feel  myself  called  upon  to  show  that  Mr.  Stephenson  has  no  claim 
to  originality  in  this  bridge,  and  that  it  has  no  resemblance  whatever,  either  in  principle 
or  construction,  to  the  Conway  or  Britannia  tubes.  On  the  contrary,  the  bridge  in 
question  is  constructed  upon  the  principle  of  the  common  cast-iron  girder  bridge,  each 
separate  beam  being  formed  of  wrought-iron  plates  connected  together  by  angle  irons. 
This  form  of  wrought-iron  girder  had  been  long  in  use  before  the  erection  of  the  "Ware 
Bridge  ;  and  it  is  defective  as  well  in  principle  as  in  construction  ;  the  great  body  of  the 
material  is  not  in  the  top  flanches,  as  it  ought  to  be,  in  order  to  attain  the  section  of 
greatest  strength.  In  Experiments  14,  15,  and  16  (see  Appendix  and  p.  10  in  the 
Report),  it  is  clearly  shown  that  the  top  flanche  of  a  wrought-iron  girder,  if  made  solid, 


should  be  more  than  twice  the  area  of  the  bottom  flanche.  Now  it  appears  that  the 
top  flanche  in  the  said  bridge  at  Ware  is  to  the  bottom  flanche  as  4  to  15  nearly;  an 
exceedingly  defective  structure.  If  this  beam  were  turned  upside  down  it  would  carry 
more  than  double  the  weight  From  the  defective  principle  upon  which  the  bridge  is 
constructed,  it  is  evident  that  Mr.  Stephenson  was  not  then  acquainted  with  the  proper 
form  of  wrought-iron  girder  bridges.  Nor  is  this  surprising,  as  no  experimental  facts 
were  at  that  time  in  existence  to  show  the  diflFerence  between  the  two  resisting  forces 
of  compression  and  extension  of  wrought-iron  beams.** — Conway  and  Britannia  Bridges^ 
by  Mr.  Fairbairn,  pp.  113,  114. 

"It  is  impossible  to  trace  any  analogy  between  a  combination  of  this  form  of  beam 
and  a  tubular  girder  with  a  cellular  top.  The  beams  in  the  Ware  Bridge  do  not  offer  a 
united  resistance  to  strain  in  the  manner  which  beams  with  a  cellular  structure  do ;  on 
the  contrary,  each  beam  has  its  distinct  part  of  the  load  to  carry,  and  that  imperfectly, 
for  want  of  a  due  proportion  in  the  top  and  bottom  flanches." — Ibidem. 

A  striking  proof  of  the  accuracy  of  Mr.  Fairbairn  is  afforded  by  the  fact,  that  it  was 
not  till  the  latter  part  of  1846,  that  Mr.  Stephenson  finally  made  up  his  mind  to  aban- 
don the  use  'of  the  chains,  for  in  the  engravings  of  both  the  Conway  and  Britannia 
Bridges,  which  were  published  in  that  year,  there  is  attached  to  them  the  name  of 
Robert  Stephenson,  Esq.,  engineer.     These  drawings  represent,  with  tolerable  accuracy, 

the  proportions  and  forms  of  the  tubes  of  both  bridges  as  they  now  exists vit, 

the  long,  low,  rectangular  galleries,  which  Mr.  Fairbairn's  experiments  had  shown  to 
be  much  better  adapted  to  the  purpose  than  the  elliptical  tubes  proposed  by  Mr. 
Stephenson.  But  mark,  in  both  cases  the  chains  are  absolutely  slwwn  attached  to  the  tubes. 
They  are  a  prominent  feature  in  the  drawing,  and  therefore  conclusive  evidence  that 
up  to  that  time  at  least  and  notwithstanding  the  discovery  of  the  increased  strength 
and  security  to  be  derived  from  the  adoption  of  the  tube  with  a  rectangular  section, 
And  the  distribution  of  the  material  on  the  top  side  in  the  form  of  cells,  Mr.  Stephen- 
eon  still  thought  the  auxiliary  support  indispensable. 

From  the  moment  that  Mr.  Fairbairn  commenced  this  experimental  investigation, 
the  whole  matter,  as  regarded  the  development  of  the  best  form  of  the  tubes,  was  un- 
reservedly in  his  own  hands.  Mr.  Stephenson  was  not  present  at  the  experiments,  he 
neither  superintended  nor  directed  them,  but  was  simply  made  acquainteawith  results, 
and  approved,  when  completed,  what  Mr.  Fairbairn  did.  And  now  what  did  Mr.  Fair- 
bairn's experiments  show  ?  They  first  of  all  confirmed  his  own  early  opinion,  that  the 
security  of  the  bridge,  if  built  at  all,  must  depend  solely  upon  the  self-contained  strength 
of  the  tube,  and  that  the  application  of  any  form  of  catenanr  would  introduce  into  the 
sU-ucture  an  agency  of  a  destructive  tendency.  They  proved  the  weakness  and  total  in- 
adequacy  of  either  of  the  sectional  forms  of  tubes  (cylindrical  or  elliptical),  thought 
of  by  Mr.  Stephenson.  They  led  Mr.  Fairbairn,  after  carefully  observing  all  the  signs 
and  symptoms  of  weakness  shown  by  the  models  when  under  strain,  to  recommend,  as 
a  stronger  form  of  tube  one  having  a  rectangular  section.  They  brought  to  light 
some  curious  and  anomalous  appearances  exhibited  by  wrought-iron  when  subjected  to 
a  crushing  force.  They  showed  that  tubes  of  a  uniform  distribution  of  material,  when 
loaded  with  an  increasing  weight,  first  yielded  on  the  upper  side ;  and  this  /a<r<,' there- 
fore, induced  Mr.  Fairbairn,  firsts  to  thicken  the  material  in  that  part^  and,  subse- 
quently, led  him  to  suggest  that  distribution  of  the  material  in  the  form  of  hollow 
cells  or  tubes,  wherein  lies  the  secret  of  the  strength  of  this  system  of  tubular  con- 
struction. 

Mr.  Fairbairn  therefore,  reasoning  from  his  experiments, — Ist,  suggested  the  rect- 
angular sections  for  the  tubes ;  2d,  discovered  that  important  and  beautiful  element  of 
strength  and  lightness,  the  cellular  arrangement  of  the  top;  and  3d,  was  mainly  instru- 
mental in  causing  the  final  abandonment  of  chains. 

Beyond  this,  after  he  was  appointed  engineer  with  Mr.  Stephenson  for  the  structure, 
he  worked  out  the  detail  of  the  tubes,  had  the  whole  of  the  working  drawings  for  the 
tubes  of  both  bridges  made  at  his  own  oflSce,  and  under  his  constant  supervision,  pro- 
portioned the  different  parts,  and  (again  the  result  of  reasoning  from  experiment)  sug- 
gested that  admirable  system  of  chain  riveting  which  is  adopted  in  those  parts  of  the 
tubes  liable  to  a  tensile  strain,  and  which  adds  in  a  material  degree  to  the  strength  of 
the  structure. 

A  bridge  with  several  spans  of  neariy  500  feet  each  was  wanted,  which  should  not 
only  be  unyielding  with  its  own  necessarily  enormous  weighty  but  which  should  possess 
within  itself  such  an  excess  of  strength  as  would  satisfy  an  incredulous  public  that  it 
would  be  abundantly  safe  when  subjected  to  the  shocks  and  vibrations  of  a  heavy  loco- 
motive engine  with  its  accompanying  train  passing  across  it  at  a  speed  of  forty  miles  an 
hour.  The  situations  both  at  Conway  and  the  Straits  afford  obstacles  of  extraordinary 
magnitude :  at  both  places  the  estuaries  were  of  great  depth,  de^ng  the  use  of  scaffold- 


674 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


I 


i 
I 


ft 


ng  to  assist  m  the  erection  of  the  bridges,  and  the  tides  washed  through  with  appalling 

Zrrr^-.7\'^trr^"'?°^*  ^"^^^  ^^«  moreover  to  stretch  from  sCe  tS 
shore  at  a  giddj  height  of  more  than  100  feet  from  the  level  of  high  water,  and  as  if 
to  render  insuperable  the  obstacles  which  Nature  had  raised  to  the  progress  of  the  engi- 

S!tL'r  ;>,^^l?'^'K^''^*'"^''^?^^"^"*^^^«^  ^««  ^^^^^^  from  the^co^troners  of  the 
?h  !  f  Ir  V  wf  ^^""^^  7^!  ^i^  «*^o™P»«hed  without  hindrance  or  obstruction  t^ 
the  rights  which  they  guarded  The  manner  in  which  all  these  necessities  were  com? 
phed  with  18  well  known      The  Britannia  and  Conway  Bridges  exist,  the  pride  ofTe 

TntTnTl  P'^^r^'  '^'"'  *"".™P^^«  ^^  ^^'  constructive  f rts.  and  immortal  monu! 
ments  to  the  men  who  were  associated  in  their  contrivance  and  execution.     It  is  t^  be 

t£:!ir''""^'''^u''  '^^'^'^^T'"'  «"^  "^*>"^«  «h«"l<i  have  arisen  under  crcum- 
1«  nf%7  '  '*"  T""^  ''°ru"  ^"^  "^""^  ^^«  t«  be  divided.  The  grandeur  and  bold- 
the  inlnuitroT?hr«rT"  ^'^"J  Stephenson's,  but  the  merits  of  tlfe  existing  struciue, 
faoVnf  .h.  f^K  1  ^.•''•*."f«'"e"t,  and  proportions  of  the  material.-the  discovery,  in 
fact,  of  the  tubular  principles  of  construction.-are  William  Fairbairn'a  ^ 

withfW  w^X.  /i  *f^^?*^^^  introductory  experiments  made  in  connection 
iTil  ,mn  •  .  r,*"^  ^^^^^  ^^^^"^  ^^  ™"«t  ^«g««-<l  the  ^q"a"y  important,  though 
Ta^tTrt?^  ^"^  • ''!;  F^''  '^'^T '  ^^'  °^^  «^^  ««'«°tifi«  ^i^overy  of  great  Td 
InS^  11  'Tu^  ^'^"^  a  peculiar  combination  of  material,  applied  to  the  simple 
and  generally  used  beam  or  girder.  A  tubular  girder,  as  the  name  implies  is  a  boTlow 
beam  constructed  of  metal  r>lates  firmly  riveted  or  fastened  togrher%;rsubi^^^^^^^^ 

^verv  boSrr-.'''r5  "'*  H?  '^°^'"^  ^«  ^''^^  ^''  ^^e  law,^ which  is  ap^lieaSe  t^ 
every  body,  be  it  solid  or  hollow,  is  observable.     The  parts  of  the  girder  above  the 

^^^'Itr'tl^^^''^''^''^^^^  -  compresfive  strain,  w^ 

tLc  extreme  diffinU  ''f  ^'^l^^f^J.^^bjected  to  a  force  tending  to  draw  them  asunder! 
known  Td  in  fK.^r  ^r"^*^'rr  ^"^  '^  ^''""^  P^^^*-  ^  »-««»«t  tension,  were  well 
pZI  '  the  earlier  stages  of  the  inquiry  it  was  considered  feasible,  and  frequent 

^^^h^lTTL™^^!,*^^""^"-".^'^"  P"""^  ^"  such  manner  that  these  kno^n  properties 

Txf erimLt  L"ffl.^dTh  "^-  "'  "  ^' V^^  "PP^^  "'^'^  ^^"^^  «^^^  ^^  ^^e  girder,  Lt^;ery 
coLtr3°r  fW  K  ^  ^"g««"'ty  of  the  contrivance,  and  nature  Son  taught  the 
P«t«S  /  ^  .u^^  unerring  laws  were  not  to  be  disregarded.  This  point  beine 
charaitPr  ^/.'h'  ?"'  '^^  ^iftribution  of  the  metal  in  a  tubullr  giixier  could^change  hf 
character  of  the  forces  which  would  act  upon  it,  Mr.  Fairbai?n's  great  merit  lies  in 
ur>nlr^«T'^.H ''^-^.^'^t  ^^  ^^^Pted  his  new  material  to  those  strains.  In  tie  top  Z 
ihFU  \  1^''^A^^  ^^  distributed  it,  in  that  beautiful  cellular  form  which  impart* 
riarflhl      '"^'   •^'''^  security  to  the  structure,  and  in  the  bottom  he  connected  the 

wlt^h^atTtrsTd'pYat!"         "'""^  "'"'  """"^'^'  '^^  ^^'^"^^^^  ^'  ^^«  J-^^ 

The  description  of  one  of  the  best  constructed  tubular  girders  will  give  the  most 

correct  idea  of  their  power  and  peculiarity.     We  select  for  iUustrl^io/ the  beauS 

503 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


670 


bridge  erected  across  the  Trent  at  Gainsborough.    Fia  603  reoresentj,  ,i  ..^nn^i    t 

&«.i  thfL    ^  •         i"     ".'"  'PV  """"S  "4  feet  each.     The  width  of  road  war 

war     The  w'dthTthf '."'T  "•^'  ''^  f ""«  ^^P'^  ■■'"""  f<"-  «  "J"""'  «"«  of  "if 
way.     ine  width  of  the  centre  pier  is  12  feet,  and  the  tubular  girders  have  a  he»r;,>» 

2d™  Z^  ''^?"'""  "'  "  'f  *•    ^?  «»*  represents  a  cross  sef tion7orm  of  ?hc  m"?f 
^f  fcv.?  li'  "%  """"  f  "■""  ''P'"'"'  «"«"«»°  i"  order  to  make  tl"  peculiariUes 

thi^'Snsril™  Z  bl  f'"''  ^'^•'"  °'  '»'=''.s'"^"  f™™  -"J '»  -SriaTeet 

rn;;«Tofmreriar;U^from\l^:'Zl«^  T'^""'  "'"•»  K'"™"" 

paraboHc  form  and  pr.ctie:«'^thT;r„;^rrf^^^^^^^^^ 

"'^'.V^;  thicknesses  instead  of  the  linear  dimensions  of  the  part™^         ^  ^ 

pla^'I  f  ^"rett'd  Wct'ht  i„"7h^  '^"""J'  '"""^  of  '■"""e  thicknesses  of  long  rolled 

^?rsZs\ttletat  °H    'is^Sntd^^^^^ 

that  part  of  the  structure  to  one  unbroken  ^M  . hi '?J^;r™;'  'f-'Vi'"  '"^™''"'« 

the  best  distribution  of  form     Each  olateTs  19  w  i        ^  '(  Pr«<='""'''le   would  be 

Uthickness  according  to  itsposittlrotte'^in'tr^^UX^^nlpVo^tle^ 


tmonnt  of  material  is  accumulated.     The  bottom  is  necessarily  connected  to  the  6id«8 
of  the  girder  by  long  bars  of  heavy  L  or  angle  iron,  firmly  riveted  to  both. 


676 


FAIRBAIRN»S  TUBULAR  BRIDGES. 


The  Sides  of  the  Girder.— The  side  plates  are  2  feet  wide  throughout,  and  of  uniform 
thickness,  excepting  in  the  immediate  neighborhood  of  the  piers  and  abutments,  where 
they  are  strengthened  and  stiffened  by  pillars  of  strong  T  iron,  to  offer  a  due  resistance 
to  the  dead  weight  of  the  girder  itself.  The  joints  are  made  with  external  covering 
plates  4|  inches  wide,  and  internal  ribs  of  T  iron,  which  suffice  to  keep  the  side  plates 
rigid,  and  enable  them  to  accomplish  their  duty  of  separating  the  top  and  bottom  of 
the  girder. 

The  Top  of  the  Girder.— In  this  part  the  principal  novelty  and  ingenuity  are  obaerr- 
able.  A  single  sheet  of  iron,  like  a  sheet  of  paper  is  easily  put  out  of  shape  by  a  com- 
pressive strain.  It  crumples  up,  and  at  once  loses  all  power  of  resistance.  A  sheet  of 
common  writing  paper,  which  when  placed  on  edge  will  nearly  support  itself,  when 
rolled  into  a  cylinder,  say  of  1  inch  diameter,  will  carry  a  considerable  weight  In 
the  same  manner  a  given  sectional  area  of  plate,  if  placed  in  that  simple  form  in  the 
top  of  the  Trent  girder,  would  crumple  up  with  a  comparatively  small  weight,  but 
when  distributed  according  to  Mr.  Fairbairn's  tubular  arrangement  it  offers  extraordi- 
nary resistance  to  compression. 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


677 


605 


The  value  of  this  arrangement  will  be  understood  when  it  is  stated  that  notwithstand- 
ing the  superior  tenacity  of  wronght-iron,  a  well  constructed  tubular  girder  only  requires 
an  excess  of  sectional  area  in  the  top  over  the  bottom  of  i..    In  the  Trent  girder  (see 

^.  604X  the  top  compartment  is  3  feet  |  inch  wide,  and  15  inches  deep,  divided  bya 
vertical  plate  into  two  rectangular  cells,  and  all  firmly  connected  by  rivets,  and  L  inm . 
Those  angle  irons  constitute  important  elements  in  its  strength.  Since  the  construction  of 
the  Trent  bridge,  the  cost  of  construction  of  tubular  girders  has  been  much  diminished  by 
a  different  arrangement  of  the  parts  of  the  top  compartment,  as  shown  in  the  following. 
Jig.  506.    This  form  is  equally  powerful  in  its  resistance.    When  the  span  of  the  bridge 


606 


reaches  180  or  200  feet,  the  top  compartment  is  arranged  as  shown  in  Jig.  507,  and 
when  it  is  under  60  feet  as  shown  injig.  508.    It  will  be  noticed  that  in  every  case  the 


eells  are  proportioned,  so  as  to  admit  of  the  entrance  of  a  man  for  the  purposes  of 
painting  or  repairs. 


71*—- >} 


7%e  Cross  Beams  or  Supports  of  the  Roadway. — ^These  are  generally,  and  ought  to  be 
universally,  made  of  iron.  In  the  Trent  bridge  they  are  made  hollow  or  box  beams,  as 
shown  in  the  annexed  figure,  fig.  509.  Their  construction  is  now  much  simpler  and 
equally  good,  thus^.  510. 

510  Ttie  Riveting. — ^Upon  the  judicious  fas- 

tenings of  the  plates  together  depends  in 
a  great  measure  the  safety  of  a  tubular 
girder  bridge.  The  system  of  riveting 
followed  in  the  several  parts  should  have 
reference  to  the  strains  which  occur  in 
those  parta  What  are  technically  called 
"lap  joints,"  where  the  ends  of  the  plate 
overlap  each  other,  and  are  connected  by 
a  single  row  of  rivets,  (vide  fig.  511,) 
should  be  avoided  in  every  part  of  the 
structure,  as  they  have  been  proved  to 
be  weak  and  insufficient  Mr.  Fairbairn 
{Phil  Trans,  part  ii.  1862)  gives  the  value 
of  single  and  double  riveted  joints,  as  70 
and  56  respectively,  the  solid  plate  being 
assumed  to  be  100. 

"Butt  joints"  and  covering  plates  are  used  throughout  the  girder,  the  length  and 
substance  of  these  covering  plates  and  the  number  of  rivets  varying  according  to  situ- 
ation. In  the  top  compartment  the  ends  of  the  plates  having  been  carefully  fitted  to 
each  other,  so  as  to  take  their  portion  of  the  strain  the  moment  the  load  is  applied,  are 
covered  by  strips  of  sufficient  width  to  receive  a  double  row  of  rivets,  one  on  each  side 
of  the  joint»  thus,  as  shown  in  fig.  512.  This  arrangement  effectually  prevents  some 
such  effect  as  indicated  in^^.  513,  which  would  occur  were  the  lap  joint  used,  and  the 
load  very  great  In  the  tops  the  rivets  are  generally  spaced  8  inches  apart  from  centre 
to  centre. 


*i 


678 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


"'f^'^^yf^wyyyaii  -^^m 


512 


As  before  mentioned,  instead  of  simple  strips  covering  the  vertical  joints  of  the  side 
plates,  mside  T  iron  bars  are  used  to  afford  stiffness,  and  prevent  the  approach  of  the 
-  top  and  bottom  (vide  fig.  514.)    Thus,  the  rivete 

being  spaced  8  inches,  the  strips  give  to  the  ex- 
ternal elevation  of  the  girder  the  appearance  of 
a  series  of  panels. 

In  the  bottom  an  exceedinglj  ingenious  and 
beautiful   arrangement  of  riveting  has  been  in- 
troduced by  Mr.  Fairbairn.     It  is  evident  that 
to  join   two  plates  together  (these   two   plates 
having  to  resist  a  force  tending  constantly  to 
separate  them)  a  certain  number  of  rivets  or  pins 
i-«         f*".^  required,  and  according  to  the  old  system  of 
wz^^msszz^   J'^'J^ting,  these  rivets  were  placed  in  single  rows 
along  the  edge  of  the  plates,  being  in  fact  either 
single  lap  joints,  or  single  butt  jointa     Suppose 
the  plates  \x\  fig.  515  to  be  each  2  feet  wide,  and 
.   ,  ,      .  \  inch   thickj  and  that  to  connect  them  there 

were  wanted  16  rivets,  each  1  inch  diameter.  It  is  evident  the  resisting  powers  of 
P'ates  are  weakened  exactly  by  the  amount  of  material  punched  out,  in  this  case 
one-third,  the  section  of  resistance  bein^  through  the  line  a  6,  and  not  through  the 
Jme  c  d.  J3ut  if  these  16  rivets,  instead  of  being  placed  all  parallel  with  the  joint, 
are  arranged  as  shown  in  fig.  516  and  covered  with  long  "  covering  plates"  instead 


515 


516 


of  "8tni)8,  It  is  equally  evident  that  they  are  in  this  position  equally  fitted  to  their 
duty  of  joining  the  plates,  and  that  the  punching  has  weakened  the  resting  powers 
of  the  plates  only  ^i^  instead  of  |.  These  proportions  will  readily  explain  the  saving 
in  material  and  weight  which  Mr.  Fairbairn's  "chain  riveting"  has  effected,  and  the 
following  figure  of  the  "  bottom"  of  the  Trent  bridge  will  show  how  it  is  practically 
applied  {fig.  517.)    The  joints  of  the  angle  irons  in  the  bottom  are  also  jointed  by 


.|f,e!L 


■^ 


517 


aocoo6o  ioo^oi 


r. ^6^ 


i  o'o  e  o  e 

-! > 


5TT3T" 
0  b  o  o  e 


3oOooaoccaoo 


0  o^ocola o  a  o  p 
)         I 

o  o>o  eolo  o  o  0  o 


o  o&e  o  oo 


k— 


;0  o  g  o  0-&  6  o  o  o  c  o  o  o  c-Q-  gy  ^^"5^—6-^^^ Vq-Q-Q  oTp-'r oT  o ^d-ll^'o -^^Sfe- 


-^.i8r_„^ 


i'  ioooo-, 


{  o;«°Ooaicaoooooeoeoc 


eoa  o  e 

OOP  o e 


o  o  oo  o 

o  o  oo  o 


-s: 


■  OOO  O  0!0 

o  o  "i.'O  ao  oo  oQOoi&o  o<yO! 


r      r 


long  corner  pieces,  as  may  be  noticed  at  a,  in  fig.  518,  which  is  a  view  of  a  short 
length  of  the  bottom  of  the  main  Trent  girder.  Having  thus  described  the  tubular 
girder  bridge  in  its  best  and  most  generally  adopted  form,  a  glance  at  the  following 
figures  {fi^s.  519,  520)  will  indicate  modifications  of  the  system  which  have  gained 
favor  in  some  quarters. 


FAIRBAIRN'S  TUBULAR  BRIDGES. 

518 


679 


519 


V 

^ 

•  1  « 

•  it 

«i 

h 

*i ' 

*w 

\» 

©  i 

A^ 

A  1   « 

«  1  « 

i%\ 

S'fB^T.j..irr77^ 

The  Proportions  and  Strength  of  Tubular  Girders. — ^The  limits  of  this  article  will  not 
admit  of  a  lengthened  examination  of  these  interesting  topics.  A  well  proportioned 
beam  or  girder  should  have  such  a  sectional  distribution  of  its  material,  that  when 
subjected  to  a  transverse  strain,  the  top  should  yield  to  compression  and  the  bottom 
to  extension  at  one  and  the  same  time;  and  as  nearly  all  materials  offer  unequal 
resistances  to  the  two  forces,  direct  experiment  can  alone  determine  the  exact  relative 
proportions  of  the  two  parts.  Thus,  the  resisting  power  of  cast-iron  to  compression 
18  nearly  six  times  greater  than  that  which  it  offers  to  extension;  but  Mr.  Fairbairn's 
ingenious  distribution  of  the  wrought-iron  plates  in  the  "  cellular  top"  has  enabled 
him  to  fix  the  relative  sectional  areas  of  the  tops  and  bottoms  of  tubular  beams  in 

the  ratio  of  12  to  11. 

The  tables  of  the  following  page  show  the  proportions  for  tubular  girder  bridges  of 
spans  from  30  up  to  300  feet 

Mr.  Fairbairn's  formula  for  calculating  the  strength  of  tubular  girder  bridges  has 
been  much  disputed,  but  at  the  same  time  it  has  had  many  able  defenders,  and  may  be 
followed  with  perfect  reliance  and  safety.  If  it  errs^  it  errs  on  the  right  side — that  of 
understating  the  real  strength;  it  is 


w« 


ade 


where  lo— »the  centre  breaking  weight  in  tons  irrespective  of  the  weight  of  the  girder 
a  —  sectional  area  of  bottom  in  inches 
<2— depth  of  beam  in  inches 

c— a  constant  derived  from  experiment  for  the  particular  form  of  girder,  and 
/—length  of  girder  between  the  supports  in  inchea 
The  formula  always  assumes  a  well  made  and  well  proportioned  girder,  having  the 
relative  areas  of  12  to  11  in  the  top  and  bottom  and  the  chain  riveting. 

The  constant  c  for  the  tubular  girders  we  have  described  was  ascertained  to  be  80. 
Let  us  now  find  by  this  formula  the  strength  of  one  of  the  spans  of  the  Trent  bridge 


'^•-■» 


680 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


681 


iff 


Table  showing  the  Proportions  of  Tubular  Girder  Bridges,  from  30  to  150  Feet 

Span. 


Span 


Fe«t.  In. 

30  0 

85  0 

40  0 

45  0 

50  0 

55  0 

60  0 

65  0 

10  0 

•75  0 

80  0 

85  0 

90  0 

95  0 

100  0 

110  0 

120  0 

130  0 

140  0 

150  0 


Centre  Breakinir 

Weight  of 

Bridj^e. 


Tons. 
180 
210 
240 
270 
300 
330 
360 
390 
420 
450 
480 
510 
540 
570 
600 
660 
720 
780 
840 
900 


Sec  Area  of 

Bottom  of  one 

Girder. 


Inches. 

14-63 

17-06 

19-60 

21-94 

24-38 

26-81 

29-25 

31-69 

3413 

36-56 

39-00 

41-44 

43-88 

46-31 

48-76 

53-63 

58-50 

63-38 

68-25 

73-13 


Sec.  Area  of 

Top  of  one 

Oirder. 


Inches. 

17-06 

19-91 

22-75 

25-59 

28-44 

31-28 

34-13 

36-97 

39-81 

42-67 

45-50 

48-34 

51-19 

54-03 

66-88 

62-56 

68-25 

73-94 

79-63 

86-31 


Depth  at  the 

Oirder  in  the 

Middle. 


Feet    In. 
2       4 


2 
3 
S 


8 
1 
6 


3  10 

4  8 


4 

1 

5 

0 

5 

6 

5 

9 

6 

2 

6 

1 

6 

11 

7 

4 

1 

8 

8 

6 

9 

3 

10 

0 

10 

9 

11 

6 

Table  showing 


the  Proportions  of  Tubular  Girder  Bridges,  from  160  to  300  Feet 

Span. 


Span. 


Feet.  In. 

160  0 

170  0 

180  0 

190  0 

200  0 

210  0 

220  0 

230  0 

240  0 

260  0 

260  0 

270  0 

280  0 

290  0 

300  0 


Centre  Breaking 

Weight  of 

Bridge. 


Sec.  Area  of 

Bottom  of  one 

Oirder. 


Sec.  Area  of 

Top  of  one 

Girder. 


Tons. 

Inches. 

Inches. 

960 

90-00 

106-00 

1020 

95-63 

111-56 

1080 

101-26 

11813 

1140 

106-88 

124-69 

1200 

112-50 

131-25 

1260 

118-13 

137-81 

1320 

123-75 

144-38 

1380 

129-38 

150-94 

1440 

135-00 

157-50 

1600 

140-63 

164-06 

1560 

146-25 

170-63 

1620 

151-88 

177-19 

1680 

157-60 

183-75 

1740 

163-13 

190-31 

1800 

168-76 

196.88 

Depth  at  the 

Girder 

in  the 

Middle. 

feet. 

In. 

10 

8 

11 

4 

12 

0 

12 

8 

13 

4 

14 

0 

14 

8 

15 

4 

16 

0 

16 

8 

17 

4 

18 

0 

18 

8 

19 

4 

20 

0 

--^-5?XH42i?.o.3e,.etons 

as  the  weight  which  a  tubnlar  girder  154  feet  between  the  supports  will  carry  sus- 
pended from  one  point  in  the  centre  before  fracture.  Now  the  actual  weight  of  this 
girder  itself  is  under  70  tons,  and  it  iiiay  safely  he  asserted  that  no  other  form  of  construc- 
Uon  would  give  so  favorable  a  result  The  centre  breaking  weight  of  one  girder  being 
864i  tons,  It  would  carry  729  tons  equally  distributed  along  its  entire  length,  and  therf 
being  two  mam  girdera  to  the  bridge,  the  ultimate  strength  of  the  structure  is  in  round 
numbers,  1,600  tons.    It  would  be  possible,  by  both  lines  of  railway  being  covered  with 


, 


heavy  goods  train,  to  have  a  load  on  the  bridge  of  about  260  tons  at  one  and  the  same 
tiu)e,  atjd  we  thus  see  there  is  a  margin  of  strength  of  six  times  the  greatest  poesible 
load.  Engineers  diflFer  in  opinion  as  to  the  excess  of  strength  which  it  is  desirable 
that  railway  structures  should  possess;  some  are  satisfied  with  even  as  low  an  ultimate 
breaking  strength  as  three  times  the  load;  but  with  a  comparatively  untried  material, 
and  one  moreover  liable  to  deterioration  from  atmospheric  influences,  the  larger  excess 

18  til  6  l^t/t^r 

On  the  discovery  of  Mr.  Fairbairn's  cellular  arrangement  for  the  top  compartment  of 
the  CJonway  and  Britannia  Bridges,  several  able  mathematicians  advocated  the  intro- 
duction of  iron  cylindrical  instead  of  rectangular  cells,  as  being  a  better  distribution  of 
the  material  to  resist  the  compressive  strain.  Mr.  Fairbairn's  original  views  were  in 
the  same  direction,  but  were  abandoned  on  account  of  the  complexity  of  construction 
and  the  difficulties  of  manufacture,  and  it  is  curious  to  notice  now  that  subsequent 
scientific  investigations  have  confirmed  the  practical  engineer's  views,  and  shown  that 
the  rectangular  cells  are  superior  in  strength.  Mr.  Tate  especially  thus  ingeniously 
argues: — "The  cells  in  a  transverse  strain  undergo  a  different  kind  of  strain  to  what 
they  are  subjected  to  in  a  simple  crushing  force  equally  distributed  over  the  section  of 
the  tube.  In  this  case  all  the  parts  of  the  section  are  equally  compressed,  and  it  is 
reasonable  to  conclude  that  the  best  form  of  cell  will  be  that  in  which  the  material  is 
equally  distant  from  the  axis  of  pressure ;  but  the  case  of  transverse  strain  is  very 
different,  the  upper  edge  undergoes  the  greatest  strain,  and  of  the  other  parts  that  which 
is  nearest  the  natural  axis  of  the  beam  undergoes  the  least ;  in  this  case  therefore  the 
material  in  the  square  cells  is  symmetrically  distributed  with  respect  to  the  axis  of 
pressure,  the  neutral  axis  of  the  beam."  . 

The  Durability  of  Tubular  Girders— On  this  head  there  is  as  yet  but  a  very  limited 
experience  as  a  basis  for  positive  assertion.  There  can  be  no  doubt  that  if  neglected  the 
eflFects  of  oxidation  upon  the  wrought-iron  plates  and  rivets  would  speedily  be  pro- 
ductive of  very  disastrous  results.  On  the  other  hand,  there  are  many  existing  ex- 
amples of  wrought-iron  structures,  such  as  iron  ships  and  other  vessels,  suspension 
bridges,  <fec,  which  with  proper  care  and  attention  have  withstood  the  wear  and  tear  of 
constant  exposure  and  use  without  any  serious  impairment  of  their  powers  of  resistance, 
for  periods  of  upward  of  thirty  years.  It  will  be  noticed  too  that  tubular  bridges 
have  been  designed  with  an  especial  view  to  the  easiest  access  to  every  part  for  the 
purposes  of  painting  and  repairs,  and  it  is  not  therefore  improbable  that  with  attention 
these  structures  will  prove  to  be  more  durable  than  either  cast-iron,  timber,  or  other 
structures  similarly  situated. 

ITieir  Cost. — In  estimating  the  cost  of  a  tubular  girder  bridge,  one  of  their  most 
important  recommendations  must  not  be  overlooked,  viz.,  the  saving  which  they  afford 
in  the  construction  of  the  masonry,  abutments,  and  piers.  For  example,  in  the  for- 
mation of  a  bridge  of  150  feet  span,  if  cast  iron  or  stone  be  the  material  employed,  vast 
sums  of  money  would  have  to  be  expended  in  the  formation  of  ponderous  and  solid 
abutments  to  receive  the  thrust  of  the  arch  and  its  load,  whereas  with  the  girder  bridge 
two  simple  well-constructed  walls  giving  a  bearing  of  five  or  six  feet  to  the  ends  of  the 
girders  is  all  that  is  necessary,  the  girders  themselves  receiving  and  maintaining  the 
strain  due  to  the  load.  The  mere  iron  superstructure  may  thus  in  some  cases  appear 
costly,  but  when  the  whole  of  the  adjuncts  of  a  bridge  are  taken  into  consideration 
there  is  perhaps  no  other  form  of  pontitecture  which  can  compete  with  the  wrought- 
iron  girder  when  the  clear  space  exceeds  70  feet.  In  estimating  the  cost  of  the  iron 
superstructure  it  may  be  assumed,  when  the  value  of  manufactured  iron  is  at  an 
average  rate,  at  20/.  per  ton  weight  fixed  and  erected. 

General  Advantages. — ^The  more  prominent  advantages  of  these  ingenious  structures, 
viz.  lightness,  strength,  security,  and  economy,  have  been  referred  to  in  the  foregoing 
remarks.  In  addition  they  are  a  ready  resource  to  the  engineer  in  localities  where 
he  is  limited  for  space.  Thus,  in  crossing  at  a  low  level  a  road,  river,  or  canal,  a  height 
of  15  inches  from  the  bottom  of  the  bridge  to  the  level  of  the  roadway  will  suffice  for 
a  width  of  bridge  which  will  admit  of  a  double  line  of  railway  or  ordinary  turnpike 
road. 

Again,  the  structures  are  inexpensively  fixed.  The  Trent  girders,  for  example, 
were  constructed  on  the  railway  embankment  close  to  the  west  abutment  of  the 
bridge,  and  drawn  across  to  their  permanent  places  without  the  expense  of  scaffolding, 
Ac  in  the  river.  The  main  girders  themselves,  in  addition  to  forming  the  main 
strength  of  the  bridge,  form  parapets  and  protection  to  the  traffic 

In  conclusion,  it  may  bo  stated  that^  although  devoid  of  the  massive  but  imposing 

elegance  of  the  stone  arch  or  the  fairy  lightness  of  the  suspension  roadway,  the  beauty 

of  a  tubular  girder  bridge  consists  in  its  usefulness  and  its  evident  fitness  for  the 

work  it  has  to  perform. 

The  Bridge  ovee  the  Rhine  bt  Cologne. — "During  the  course  of  autumn,  1849, 


682 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


683 


III 

III 

nil 


^J"-.  ^a"*bairn  of  Manchester,  was  induced  hy  representations  made  to  him  through 
a  high  official  functionary,  to  propose  to  the  Prussian  Government  a  plan  for  an  iron 
bridge  across  the  Rhine  at  Cologne  on  the  tubular  principle.     This  plan  met  with  the 
entire  approbation  of  the  scientific  world  at  Berlin,  was  sanctioned  by  the  King  and 
was  all  but  adopted  by  the  Prussian  Cabinet.     It  happened,  however,  that  simulta- 
neously with  the  proposal  of  Mr.  Fairbairn,  one  Oberbaurath  Lentze  had  become  convinced 
that  a  suspension  bridge  was  the  true  means  of  communication  across  the  Rhine.     He 
had  arrived  at  this  conclusion  after  years  of  patient  investigation,  and  so  far  worthy  of 
all  praise  though  it  somewhat  unfortunately  chanced  that  his  discovery  was  some  thirty 
years  too  late,  so  that  his  labors,  which  would  have  been  at  the  height  of  science  in  1820 
have  only  served  to  illustrate  a  job  in  1850.     Here,  in  England,  we  have  some  little 
notion  ot  the  nature  of  jobs,  but  we  question  whether  any  more  colossal  in  this  kind  has 
ever  been  perpetrated  in  our  palmiest  days  of  corruption  than  the  attempt  of  our  worthy 
friend  Herr  Van  der  Heydt,  in  whose  paper,  if  we  are  not  mistaken,  the  celebrated 
tgment  of  the  payment  of  6,000/.  to  the  editors  of  the  'Times'  by  the  Danish  Govern- 
ment first  appeared,  to  bolster  up  the  scheme  of  M.  Lentze,  and  to  throw  cold  water 
upon  that  of  Mr.  Fairbairn.     What  mattered  it  that  Baron  Humboldt,  the  Nestor  of 
physical  science,  sided  with  Mr.  Fairbairn,  or  that  the  King  of  Prussia,  in  one  of  his 
happy  moments,  had  graciously  extended  his  royal  protection  to  the  English  engineer! 
Was  not  M.  Van  der  Heydt,  and  the  whole  army  of  the  Prussian  bureaucracy,  whose  name 
18  Legion,  arrayed  on  the  other  side  ?   Still  the  English  scheme  must  be  burked  officially 
It  was  to  be  smothered  in  due  form  with  the  cushion  of  bureaucracy ;  so  a  commission 
was  appointed  to  inquire  into  the  English  tubular  bridges;  and  of  whom  do  our  readers 
suppose  that  it  consisted?  Why  of  Herr  Oberbaurath  Lentz  himself  and  another  person 
who  after  due  deliberation,  set  off  for  England  on  their  scientific  mission.     Why  need 
we  detail  at  length  the  wanderings  of  these  duumviri  of  bureaucracy?  how  they  landed 
in  England— how  they  were  received  with  marked  courtesy  by  Mr.  Fairbairn— how  they 
saw  the  Conway  Bridge,  the  Britannia  Bridge,  and  other  structures  of  minor  dimensions 
in  Lancashire?    Suffice  it  to  say  that  they  were  quite  blind  to  the  merits  of  tubular 
bridges,  and  made  their  report  dead  against  tubular  bridges  and  strongly  in  favor  of 
sus^nsion  bridges— a  report  which  was  adopted  by  the  government,  that  is  to  say 
by  Herr  Van  der  Heydt,  who  forthwith  issued  his  famous  notice,  calling  upon  the 
engineers  of  the  whole  world  to  compete  for  the  honor  of  contributing  to  the  glorifica- 
tion of  Herr  Oberbaurath  Lentze,  whose  plans  have  been  long  since  in  the  bureau  of 
M.  Van  der  Heydt,  and  in  all  probability  will  be  ultimately  carried  out"— Times, 

W.  Fairbairn,  Eiq.,  to  Baron  Humboldt. 

"My  dear  Baron  Humboldt,— I  gather,  from  an  article  which  has  recently  appeared 
m  the  '  Times'  newspaper,  and  from  a  communication  which  his  Excellency  AL  Van 
der  Heydt  has  honored  me  with,  that  a  most  unfortunate  decision  has  been  come  to  by 
the  authorities  at  Berlin,  with  reference  to  the  important  structure  by  which  it  is  in- 
tended to  connect  the  opposite  banks  of  the  Rhine  at  Cologne.  It  having  been  my  good 
fortune  to  have  been  consulted,  many  months  ago,  on  the  subject  of  this  important 
bridge,  and  to  have  visited  Berlin  for  the  purpose  of  submitting  my  proposals,  I  hold  it 
due  to  the  warm  recommendation  which  emanated  from  our  excellent  friend  in  Lon- 
don, the  Chevalier  Bunsen— to  the  lively  interest  you  manifested  in  favor  of  the  object 
of  my  journey,  and  also  to  the  gracious  approval  expressed  by  His  Majesty  the  King 
of  Prussia  in  person— to  make  known  as  widely  as  possible  the  insuperable  objections 
which  in  my  opinion,  attach  to  the  limited  programme  which  has  recently  been  issued 
from  the  bureau  of  the  Minister  of  Public  Works. 

ir  "^  ^'*?T^  ^®*'^®  ^^"  ^®  allowed  to  convey  an  intimation  of  a  genuine  conviction,  M. 
Van  der  Heydt  acknowledged  at  the  palace,  on  the  1st  of  November  last,  that  no  struc- 
ture should  ever  be  allowed  to  cross  the  Rhine  which  was  not  calculated  to  meet,  with 
perfect  security,  the  utmost  requirements  of  the  most  extended  traffic,  and  the  possible 
contingencies  of  great  military  operations.  Your  own  enlarged  conceptions  at  once 
prompted  you  to  acknowledge  that  the  design  (which  at  that  time  had  received  the 
sanction  of  the  authorities)  was  totally  unfit  for  these  purposes,  and  to  admit  that  a  sus- 
pension bridge,  owing  its  strength  to  a  flexible  catenary,  was  inadequate  to  the  transport 
of  heavy  weights.  But  when  I  submitted  the  results  which  had  been  accomplished  in 
this  country  by  the  judicious  application  of  a  material  until  recently  untried  in  such 
structures— when  I  announced  the  successful  realization  of  one  of  the  boldest  con- 
ceptions of  modern  times— when  I  stated  that  tidal  streams,  such  as  the  river 
Conway  and  the  Menai  Straits,  had  been  crossed  by  solid  and  unyielding  bridges 
of  enormous  span,  which  were  capable  nevertheless  of  sustaining  ten  times  the  greatest 
possible  strain  that  the  heaviest  railway  traffic  could,  in  practice,  subject  them  to— 
when  I  had  shown  that  this  new  principle  of  construction  was  peculiarly  adapted 


.,„  ^,  #  <^  -J 


to  surmount  the  numerous  difficulties  which  the  passage  of  the  Rhine  offers,  by 
requiring  very  few  and  comparatively  small  piers  in  the  stream,  and  thus  allowing 
of  the  passage  of  large  timber  rafts  in  the  summer,  and  offering  the  least  possible 
resistance  in  times  of  floods  and  breaking  up  of  ice  in  the  v/inter;  and,  above  all, 
when  I  had  proved  that  a  structure  so  much  superior  could  be  erected  and  fixed 
at  an  outlay  considerably  below  that  which  had  been  demanded  for  a  very  imper- 
fect one — I  confess  I  was  not  prepared  to  find  the  Minister  of  an  enlightened  and 
powerful  people  asking  for  the  assistance  of  the  world  at  large  to  perpetuate  a 
scheme  unworthy  of  Prussia,  unworthy  of  the  practical  scientific  knowledge  of  the 
age,  and  in  opposition  to  the  deliberate  and  carefully-weighed  opinion  of  Science's 
greatest  ornament. 

"Pardon  me  for  the  warmth  with  which  I  address  to  you  this  remonstrance; 
but  1  feel  that  your  unwearied  exertions,  and  the  friendship  which  yon  unreservedly 
testified  to  me,  call  upon  me  to  urge,  as  forcibly  as  I  can,  the  retracing  of  the  un- 
fortunate steps  already  taken.  We  live  in  times  of  progress.  A  scientific  discovery, 
or  a  practical  improvement  of  any  kind,  cannot  be  confined  to  a  particular  locality  or 
to  one  countrv,  it  becomes  at  once  the  property  of  all.  The  community  of  Knowl 
edge — the  most  powerful  destroyer  of  national  prejudices  and  antipathies,  as  it  is 
the  surest  foundation  for  general  and  permanent  peace  and  good  will — must  ride  over 
and  bear  down  individual  ignorance  and  petty  bureaucratic  objections.  Punctuality 
and  rapidity  in  our  inter-communications  have  become  almost  essentials  of  our  ex- 
istence; and  in  this  manner  all  Europe  may  be  said  to  be  interested  in  the  completion 
of  that  railway  system  which  will  traverse  the  Prussian  dominions  from  one  extremity 
to  the  other. 

"  And  now  let  me  point  out  the  lamentable  imperfections  which  characterise  the 
Minister's  programme,  and  the  limitations  and  requirements  which  will  effectually 
trammel  the  efforts  of  men  of  genius,  and  deter  those  of  experience  and  reputation  from 
entering  at  all  upon  the  competition. 

"  It  is  an  express  condition  of  the  scheme  that  the  railway  communicatio*  is  not 
to  be  continuous,  and  the  public  will  therefore  continue  to  suffer  the  annoyance 
and  inconvenience  of  considerable  delays ;  for  it  may  be  safely  said  that  the  proposal 
of  disintegrating  a  train  at  one  terminus  and  drawing  it  across  to  the  other  by  men 
or  horses,  bit  by  bit,  and  hour  by  hour,  will  offer  equal,  if  not  greater,  obstacles  to 
a  rapid  journey  than  the  existing  system  does.  How  much  better  would  it  be  that 
the  bridge  should  embody  within  itself  such  elements  of  strength  and  durability 
as  would  afford  at  all  times  and  in  all  seasons  a  safe  transit  to  those  means  of 
locomotion  which  constitute  the  wonder  and  glory  of  the  age?  Instead  of  such  a 
permanent  and  substantial  structure,  will  the  Prussian  Government  sanction  the  erec- 
tion of  one,  the  feeble  and  rickety  constitution  of  which  would  shudder  at  the  very 
sight  of  a  locomotive?  Surely  not  1  Public  opinion  must  step  in  and  forbid  it  What 
is  wanted  is  a  bridge  to  connect  the  existing  railways,  not  one  that  will  permanently 
separate  them. 

"But  again;  it  is  stated  that  the  difference  between  the  levels  of  the  existing 
railways  and  that  required  for  the  roadway  of  the  intended  bridge  is  too  great  to  be 
overcome  by  the  locomotive  within  a  short  distance  of  length.  The  objection  is  purely 
imaginary;  for  I  can  state  from  personal  examination,  that  the  necessary  gradient 
would  not  be  so  heavy  as  several  which  are  worked  with  great  ease  in  this  country 
Besides,  on  the  left  bank  of  the  Rhine  the  terminus  of  the  Aix-la-Chapelle  line  is  at  the 
right  level ;  and  that  on  the  side  of  Deutz  may  without  difficulty  be  reached  by  any 
easy  gradient  of  less  than  1  in  100. 

"Without  meaning  the  slightest  disrespect  to  the  author  of  the  design  for  the  chain 
bridge,  I  must  repeat  my  firm  and  deliberate  conviction,  that  it  would  prove  an  incom- 
plete and  unsatisfactory  structure.     A  permanent,  inflexible,  durable,  and  handsome 
bridge,  of  enormous  strength  (the  breaking  weight  of  the  bridge  I  proposed,  with  the 
span  of  310  feet  was  equal  to  6,000  tons  or  120,000  cwt,  equally  distributed  over 
each  span,  giving  as  the  ultimate  strength  of  the  bridge,  with  four  spans,  24,000  tons, 
or  480,000  cwts),  adapted,  by  arrangements  which  I  have  now  in  progress  of  execution 
for  similar  purposes  in  this  country,  to  give  every  possible  facility  to  the  navigation 
'  th*^  river — calculated  to  carry  across  the  heaviest  railway  train  at  any  speed, 
I  you  might  cover  with  the  most  powerful  ordnance  from  end  to  end, 
»d  at  Cologne  within  the  sum  which  has  been  demanded  for  the  chaiv. 
_^  .  <  statements  are  not  the  imaginings  of  a  sanguine  mind ;  but  their  accuracy  iw  ^ 
be  corroborated  by  numerous  examples  of  a  similar  character  which  have  been  erected 
in  this  country. 

"If,  therefore,  the  determination  of  the  Minister  of  Public  Works  to  erect  a  chain 
bridge  cannot  be  shaken,  I  confidently  anticipate  that  such  an  event  will  not  be  allowed 
to  pass  by  without  a  strong  protest  on  the  part  of  those  who  are  in  advance  of  the 


684 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


i 


i«to  to'f«rwrn5"t'"''°"'  a  much  greater  length  than  I  at  first  anticipated.  My  anr- 
mStt tr.;i,^y"f„?r  '""""y-P^^^lview.  on  .he  eubject  .fa  fi«d  Lfdge 
go^'hetl^  "P'e^ion  of  my  profound  esteem,  and  with  best  wishes  for  your  continued 

obSS  «"*.nt  "■"""•  "^  *■*"  ^"''  °'"»'»'<">  y»«  «'7  ^"'W"'  "d  veiy 


"Mancheflter,  April  15.' 


"  "William  Fairbaibn." 


Strurturei.     By  \V.  FairS  E^    P  F     ?^     Vx.  '^P'"'^?  ">  JJ""'""*'  and  other 
Chester  indHol^h^nL-^    E.ver  Conway  and  the  Menai  Straits  on  tie  line  of  the 

n/w  e^a  ?a  ^e  S?rr?nf  k'!^^^'  T^  only  attained  that  object,  but  it  has  established  a 
«n^,VHM.oIf  •  1  J  of  badges,  by  the  development  of  the  properties  of  a  hitherto 
whTl  arn^^^^^^  "^^  engineer  of  t*he  present  da^  t^o  conqur  obstacles 

"An  „n5  J^       /°*  1*^  "^^""^  considered  insurmountable.  ^ 

tiio«f  ^rf  •  5^  f  ,  '"■'^^  »»nportance  to  the  scientific  world,  to  the  public  and  to 
be?oTanvthir  d  f'/  '"^''k'^'  ^"^"'^ ^  ^'^^^  responsibilities  on  C  eCeer' 
«Htnf!!^  •  ^r^^°'^^  ^^""^^  ^^  accomplished,  it  became  absolutely  necessarfU)  in' 
SudL.fK"'"-*'^  experimenteto  determine  the  practicability  of  su Jh  a  sSre    n 

r  q  u^?  ^f  Mr  ^^.1' "^'^Zl^P^^'^'^^  ^?^  «^^«^  P^^P^'^^^^  ^^  the  tube     I?  the 

"  E^DerimP„fi?n    °     i'     ^?r  '^  ?^°^'  ^^  *^"'"^  «^'^«^«^  ^^  «o°d««t  this  inquiry 
taken^butl?  iln  K     '"^*''  -i^'P^f^'  ^^  rectangular  tubes  were  accordingly  unL- 

form  were  best^l^fw^^  ^'^"  '^'  '^"^^  ^^'^'"^^  ^^'^^  ^^«««  ^^  ^  rectangular 

lorm  were  best  calculated  for  the  purpose.     It  was  not,  however  until  I  had  adnnf^/1 

^atentardlntctT/r  M  '"^  ^'^C'"*  T'  ™'"«  «'  'l>rSar  form  beoam'eP^,^ 
cSny  ?o7cL       ^  '''»°''"«'y  «qn«"«  'n  that  part  to  offer  sufficient  resistonce  to  the 

.imp'y'7ute°''tL\''°if!tiSMW  h"'"''"'""  ^''^  the  details  of  the  e:.periment,  but 
TtEe  eir^t^ir^L'' ,w'''ft^^'^™5  necessary  to  adopt  some  other  shape  thanVhose 
t«I«  as  to  effX,?  AtllEi  f  ^l."'''  '  w  "■  ^  P'-opo'-tio-  the  top  and  bottom  sides  of  the 
S  enrur*:  thfml.'^^r f  ce  tfTs  Z  "eT  t'T^l  '"^.r """'T'  """^  '""' 
dearly  indicated  by  the  rectangular":,™    .id  tKrCLn'^fTelfsTthrtl'sid: 

s::m7iS.:!^rhi"s7ng"  ";,r**"" »» "■*  -^^-^ '»-  """■  ""o  brd-LM: 

i^iTl''  discovery  of  the  cellular  top,  and  the  greatly  increased  value  which  a  tube 
fcalp^t^^ter^^^^^  experimen^  at  one!  suggLed  a  modified  foTm  of  tubular 
giraer  adapted  to  shorter  spans.  This  description  of  bridge  is  now  becomine  eeneral  • 
"eryTs:SS^^^^^^  of  resistance,  greWseeurity'and  its  adapSnTalmost 

wfe7if  ro7pnn«ll!  T  'k^^  "^f^  reasonably  infer  that  wrought  iron  is  cheaper  and 
W  no  douhfT^^ll  r^^^  with  any  other  description  of  miterials.  It  may,  and  I 
aS  d^av  than  <^^^^^^  urged,  that  wrought-iron  is  much  more  subject  to  oxidation 
Sn  XiriL  ?r^  '  n?  *""  'i^°' '  "  <'''-t»»"«^°<^«  ^^ch  cannot  be  disputed ;  but  that 
artwo  LatHf  Zf  n?r  "fS  'g^^^^  oji  the  part  of  those  having  charge  of  the  structure, 
du^WeTr  afmos?  anv  Ki'77  three  years  will  effectuali;  protect  it,  and  render  it 
accTss  ble  L  eve?v  3  tn?V^  ^Ti  ^"^'^^^  *^^  girders,  as  now  constructed,  are 
nnf  hflf  Anl?  ^  ?^  J  r^.^"""^'  ^^  ^^'^^^'^^  attention,  I  can  see  no  reason  why  they  should 
^rn?fnn^K -f  •   1^^  T  l^  y«*"-     Another  objection  brought  againsFthisdc 

S  tL  Sr/ltirVl'^'  "^^^  ^^^^'"i"?  ^^«««;  ^^^  fr«™  the  numb  r  of 
joints,  the  whole  is  considered  by  some  as  dangerous  and    nsecure.     Now  as  regards 

single  rivet  to  get  loose  (unless  the  wo^k  is  impT^n/  x^ted)  •  'and  Tl^e'wL: 

^c"r^  ?n^rw:'l/adTn."d^"^"t^^'  ^^^^  A  S^sc^iptio^"  of    Minting  sotrraln^ 
f  «^!V  .•     n  ^^*P^^J^  r^^'f'  «"y  description  of  strain,  as  that  of  riveted  platen 

stXLl'^t    ^K-      "°^rff^"^'^^?  this  subject;  and' I  have  only  to  instance 
steam  boilers,  iron  ships,  and  other  vessels  subjected  to  severe  strain,  as  examples  of 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


685 


the  strength  and  tenacity  of  riveted  plates;  in  fact,  rivets  seldom  or  never  get  loose, 
but  retain  their  position  under  every  species  of  strain,  and  become,  as  it  were,  integral 
parts  of  the  structure  in  common  with  the  plates  themselves. 

"  In  submitting  these  remarks  to  the  consideration  of  the  Commissioners,  and  in 
order  to  bear  them  out,  it  may  not  be  uninteresting  briefly  to  notice  a  few  of  the  results 
of  the  experiments  illustrative  of  this  subject,  and  to  show,  with  a  greater  degree  of 
exactitude,  the  nature  and  value  of  this  description  of  structure.  ^  For  these  objects,  I 
beg  to  insert  a  few  of  the  earlier  experiments  on  different  descriptions  of  tubes,  as  re- 
corded in  a  report  addressed  to  Mr.  Stephenson  and  the  directors  of  the  Chester  and 
Holyhead  Railway,  the  particulars  of  which  have  already  been  before  the  public.** 

(Here  follow  the  details  of  the  experiments  referred  to.) 

The  experiments,  of  which  the  above  is  a  brief  notice,  have  led  to  other  improve- 
ments of  great  utility  in  practical  science,  and  probably  of  equal  value  with  those  for 
which  they  were  originally  undertaken. 

"  I  have  already  stated  that  the  difiiculty  which  the  weakness  of  the  material  to 
resist  a  crushing  force  occasioned,  was  overcome  by  the  adoption  of  the  cellular  form 
of  top;  but  another,  and,  to  my  mind,  very  serious  diflSculty  presented  itself,  in  the  re- 
ductK>n  in  the  strength  of  the  plates  at  -the  joints  bjr  the  ordinary  method  of  riveting, 
in  the  bottom  and  those  parts  where  the  tensile  strain  came  into  operation.  This  led 
to  a  new  system  of  riveting,  which,  without  weakening  the  body  of  the  plate  to  so  great 
an  extent  as  formerly,  gives  a  joint  of  almost  equal  strength  with  the  plate  itself,  and 
thus  adds  in  a  most  material  manner  to  the^security  of  the  structure. 

**  Consequent  upon  the  experiments  and  the  results  obtained  therefrom,  numerous 
advantages  presented  themselves  in  the  construction  of  wrought-iron  girders.  Tho 
strength,  ductility,  and  comparative  lightness  of  the  material  are  the  important  elements 
of  tiese  girders ;  and  their  elasticity,  retention  of  form,  and  other  properties,  render 
them  infinitely  more  secure  than  those  composed  of  cast-iron,  which,  from  the  brittle 
nature  of  the  material  and  imperfections  in  the  castings,  are  liable  to  break  without 
notice,  and  to  which  the  wrought-iron  girder  is  not  subject  This  is,  however,  pro- 
bably of  less  importance,  as  the  wrought-iron  girder  will  be  found  not  only  cheaper, 
but  (when  well  constructed,  and  upon  the  right  principle)  upwards  of  three  times  the 
strength  of  cast-iron.  I  have  elsewhere  stated  to  the  Commissioners  that  the  experi- 
ments attracted  the  notice  generally  of  railway  engineers,  and,  amongst  others,  that  of 
Mr.  Vignoles,  who  immediately  gave  an  order  for  two  wrought-iron  girder  bridges  for 
the  Blackburn  and  Bolton  Railway  Company: — one  to  cross  the  Liverpool  and  Leeds 
Canal,  and  the  other  over  the  turnpike  road,  both  in  the  vicinity  of  Blackburn.  These 
bridges  were  constructed  simultaneously  with  another  of  similar  form  (with  a  cast-iron 
top)  executed  by  Mr.  Dockray,  under  the  direction  of  Mr.  Robert  Stephenson,  for 
carrying  the  turnpike  road  over  the  London  and  North-Western  Railway  at  Camden 
Town.  Those  for  the  Blackburn  and  Bolton  Railway  were,  however,  the  first  adapted 
for  railway  traffic ;  and  although  they  are  probably  not  so  well  proportioned  as  others 
since  constructed,  they  nevertheless  exhibit  extraordinary  powers  of  resistance ;  and 
conceiving  that  a  description  of  these  bridges,  with  the  tests  to  which  they  were  sub- 
jected, might  be  useful,  I  have  great  pleasure  in  submitting  the  same,  with  the  necea- 
aary  drawings,  to  the  consideration  of  the  Commissioners. 

Explanation  of  the  Engravings,  descriptive  of  the  Hollow  Girder  Bridge  over  the  Turnpike 

Road  near  Blackburn. 

"Fig.  621  is  an  elevation  or  side  view  of  the  girder,  each  66  ft  long,  and  bedded  on 
cast-iron  base  plates. 

*^Fig.  622  is  a  transverse  section  of  the  bridge,  showing  the  sides  of  the  cross-beams, 
and  the  cross  sections  of  the  outside  and  middle  girders. 

"Fig.  523  is  an  enlarged  transverse  section  of  the  outside  girder,  showing  the  at- 
tachment of  the  cross-beams,  which  are  riveted  to  the  bottom  of  the  girder,  exclusive 
of  two  bolts  A  A,  which  extend  through  the  bottom  plates  and  angle  iron  of  the  girder, 
and  the  top  and  bottom  plates  of  the  cross-beam. 

"  Fig.  624  is  an  enlarged  view  of  a  part  of  the  side  of  the  large  girder,  exhibiting  a 
transverse  section  of  the  cross  beam,  at  b,  which  is  made  of  wrought-iron,  with  the  top 
and  bottom  plates  so  proportioned  as  to  equalise  its  powers  of  resistance  to  the  force  of 
compression  on  the  top,  and  that  of  tension  on  the  bottom.  It  also  exhibits  the  mode 
of  riveting  up  the  joints  of  the  side  plates  with  the  covering  strip  c  o  c,  and  the  addition- 
al strength  as  obtained  by  the  attachment  of  T  iron  in  the  interior  of  the  tube. 

''Ftg.  525  is  a  plan  of  the  bridge,  showing  on  one  side  the  platform  and  the  rails,  and 
on  the  other  the  cross-beams,  which  in  this  bridge  are  placed  6  ft.  asunder ;  but  in  those 
more  recently  constructed,  I  have  placed  them  at  distances  of  only  4  ft,  and  consider 
this  arrangement  preferable. 


Ill 


; 


w 


i 


) 


686 


FAIRBAIRN'S  TUBULAR  BRIDGES. 


622 


524 


525 


II  II  II  n  n  II  n  I)  II  n  n  II  n  n  11^ 


ff 


"From  the  above  description  it  will  be  seen  that  the  whole  is  a  strong  and  perfectly- 
rigid  structure.  With  three  longitudinal  girders,  a  bridge  of  this  description  will 
support  a  load  equally  distributed  of  760  tons;  and  in  order  to  render  it  safe,  under 
every  species  of  strain,  the  middle  girder  is  made  nearly  double  the  strength  of  those  on 
the  outside.  This  is  essential,  as  two  trains  may  be  passing  the  bridge  at  the  same 
moment;  in  which  case  the  middle  girder  would  be  subjected  to  a  pressure  equal  to 
double  the  load  on  the  outside  girders. 

"In  the  construction  of  bridgesof  larger  span,  I  generally  prefer  only  two  large  longi- 
tudinal girders  with  strong  cross-beams  every  three  feef^  of  sufficient  length  to  admit  two 
lines  of  rails,  and  sufficient  room  for  two  trains  to  pass  at  the  same  time.  This  mode  of 
construction  is  preferable  to  the  three  girders,  as  it  effects  greater  simplicity  in  the 
structure,  and,  from  every  appearance,  renders  the  bridge  equally  effective  and  secure. 

"Having  thus  described  tlie  advantages  peculiar  to  this  description  of  bridge,  I  will 
now  direct  the  attention  of  the  Commissioners  to  the  tests  to  which  the  Blackburn 
Bridge  was  subjected,  previous  to  its  opening  for  public  traffic.  The  experiments  were 
made  in  the  presence  of  Captain  Coddington,  the  Government  Inspector  of  Railways, 
and  Mr.  Flanagan,  engineer  of  the  line,  as  follows: — 

"Three  locomotive  engines,  weighing  60  tons,  were  coupled  together,  and  passed 
over  the  bridge  at  velocities  varying  from  5  to  15,  and  25  miles  an  hour.  This  load 
(60  tons)  produced  a  deflection  of  -025  of  a  foot,  or  about  -^^jths  of  an  inch,  and  that 
without  any  perceptible  increase  in  the  deflection  arising  from  the  different  rates  of 
speed.     In  fact  the  deflection  was  found  to  be  the  same  at  all  velocities. 

"After  these  tests  were  made,  two  wedges  or  inclined  plates  were  fitted  to  the  rails, 
jig.  626,  at  the  middle  of  the  bridge,  and  the  engines  run  over  them  at  the  rate  of  1  to 

526 


RAIL 


7 


10  miles  an  hour.  The  shock  of  the  engines,  as  they  respectively  fell  upon  the  girders, 
from  a  height  of  one  inch,  the  thickness  of  the  wedge  at  d,  gave  an  increased  deflection 
from  025  to  -035  of  a  foot,  and  another  set  of  wedges,  \\  feet  in  height,  gave  a  further 
increase  of  deflection  (at  the  same  velocity)  of  •035  to  .045  of  a  foot 

"From  the  above  experiments  it  appears  evident  that  wrought-iron  girders  are  well 


FATS. 


687 


calculated  to  resist  not  only  a  heavy  dead  weight,  but  the  force  of  impact  administered 
with  an  unsparing  hand ;  for,  in  fact,  the  girders  were  not  injured  by  the  blows  inflicted 
by  engines  falling  a  height  of  \\  inches  upon  them,  but  restored  themselves  to  their 
original  position  from  which  they  were  deflected  by  the  shock. 

"On  the  whole  we  may,  therefore,  reasonably  conclude  that  the  present  structure  is 
not  only  the  strongest,  but  the  best  calculated  to  resist  strain  when  applied  to  lai^e 
spans,  and  particularly  in  situations  where  bridges^  with  a  perfectly  horizontal  soffit, 
are  alone  admissible. 

(Signed)        ""William  FAmBAiHN." 
"  Manchester,  ApHl  26th,  184a'' 

FAN  (Eventail,  Fr. ;  Fdctur,  Germ.)  is  usually  a  semi-circular  piece  of  silk  or  paper, 
pasted  double,  enclosing  slender  slips  of  wood,  ivory,  tortoise-shell,  whale-bone,  &c., 
arranged  like  the  tail  of  a  peacock,  in  a  radiatiag  form,  and  susceptible  of  being  folded 
together,  and  expanded  at  pleasure.  This  well-known  hand  ornament  is  used  by  ladies 
to  cool  their  faces  by  agitating  the  air.  Fans  made  of  feathers,  like  the  wing  of  a  bird, 
have  been  employed  from  time  immemorial  by  the  natives  of  tropical  countries. 

Fan  is  also  the  name  of  the  apparatus  for  winnowing  corn.  For  an  account  of  thff 
powerful  blowing  and  ventilating  fan  machine,  see  Foundry  and  Ventilator. 

FARINA  (Farirusy  Fr. ;  MM,  Germ.)  is  the  flour  of  any  species  of  corn,  or  starchj 
root,  such  as  potato,  arrow  root,  &c.    See  Bread  and  Stajich. 

FATS  (Graisses,  Fr. ;  Fette,  Germ.)  occur  in  a  great  number  of  the  animal 
tissues,  being  abundant  under  the  skin  in  what  is  called  the  cellular  membrane,  round 
the  kidneys,  in  the  folds  of  the  omentum,  at  the  base  of  the  heart,  in  the  mediastinum, 
the  mesenteric  webb,  as  well  as  upon  the  surface  of  the  intestines,  and  among  many  d 
the  muscles.  They  vary  in  consistence,  color,  and  smell,  according  to  the  animals 
from  which  they  are  obtained ;  thus,  they  are  generally  fluid  in  the  cetaceous  tribes, 
soft  and  rank-flavored  in  the  carnivorous,  solid  and  nearly  scentless  in  the  ruminants, 
usually  white  and  copious  in  well-fed  young  animals ;  yellowish  and  more  scanty  in  the 
old.  Their  consistence  varies  also  according  to  the  organ  of  their  production ;  being 
firmer  under  the  skin,  and  in  the  neighborhood  of  the  kidneys,  than  among  the  moveable 
viscera.  Fat  forms  about  one  twentieth  of  the  weight  of  a  healthy  animal.  But  as 
taken  out  by  the  butcher  it  is  not  pure,  for  being  of  a  vesicular  structure,  it  is  always 
enclosed  in  membranes,  mixed  with  blood,  blood-vessels,  lymphatics,  &c.  These  foreign 
matters  must  first  be  separated  in  some  measure  mechanically,  after  the  fat  is  minced 
small,  and  then  more  completely  by  melting  it  alon?  with  hot  water,  passing  it  through 
a  sieve,  and  letting  the  whole  cool  very  slowly.  By  this  means  a  cake  of  cleansed  fat 
will  be  obtained.  Many  plans  of  purifying  fats  have  been  proposed ;  one  of  the  best  is 
to  mix  two  per  cent,  of  strong  sulphuric  acid  with  a  quantity  of  water,  in  which  the 
tallow  is  heated  for  some  time  with  much  stirring ;  to  allow  the  materials  to  cool,  to 
take  off  the  supernatant  fat,  and  re-melt  it  with  abundance  of  hot  water.  More  tallow 
will  thus  be  obtained,  and  that  considerably  whiter  and  harder  than  is  usually  procured 
by  the  melters. 

I  have  found  that  chlorine  and  chloride  of  lime  do  not  improve,  but  rather  deterio> 
rate,  the  appearance  of  oils  and  other  fatty  bodies.     According  to  Appert,  minced  suet 
subjected  to  the  action  of  high-pressure  steam  in  a  digester,  at  250°  or  260"  F.,  becomes 
80  hard  as  to  be  sonorous  when  struck,  whiter,  and  capable,  when  made  into  candles,  of 
giving  a  superior  light.    A  convenient  mode  of  rendering  minced  tallow,  or  melting  it,  it 
to  put  it  in  a  tub,  and  drive  steam  through  it  from  numerous  orifices  in  ramifying  pipes 
placed  near  the  bottom.     Mr.  Watt  assures  me  that  his  plan  of  purifying  fats,  patented 
in  March,  1836,  has  been  quite  successful.    He  employs  dilute  sulphuric  acid,  to  which 
he  adds  a  little  nitric  acid,  with  a  very  small  quantity  of  bichromate  of  potash,  "  to  sup- 
ply oxygen ;"  and  some  oxalic  acid.     These  are  mixed  with  the  fat  in  the  steaming 
tub.     When  the  lumps  of  it  are  nearly  dissolved,  he  takes  for  every  ton  of  fat^  one 
pound  of  strong  nitric  acid,  diluted  with  one  quart  of  water;  to  which  he  adds  two 
ounces  of  alcohol,  naphtha,  sulphuric  ether,  or  spirits  of  turpentine;    and  after  intro- 
ducing this  mixture,  he  continues  the  boiling  for  half  an  hour.     The  fat  is  finally 
washed.     As  I  do  not  comprehend  the  modus  operandi  of  these  ingredients,  I  shall 
abstain  from  any  comment  upon  the  recipe. 

Others  have  proposed  to  use  vegetable  or  animal  charcoal  first,  especially  for  rancid 
oils,  then  to  heat  them  with  a  solution  of  sulphate  of  copper  and  common  salt,  which  is 
supposed  to  precipitate  the  fetid  albuminous  matter.  Milk  of  lime  has  been  also  pre- 
scribed: but  it  is,  I  believe,  always  detrimental. 

Davidson  treats  whale  oil  with  infusion  of  tan,  in  order  to  separate  the  gelatine  and 
albumine  in  flocks;  next  with  water  and  chloride  of  lime,  to  destroy  the  smell;  and 
lastly,  with  dilute  sulphuric  acid,  to  precipitate  all  the  lime  in  the  state  of  a  sulphate. 
This  is  certainly  one  of  the  cheapest  and  most  effective  methods  of  purifying  that 
substance. 

44 


688 


FATS. 


FATS. 


689 


il 


Braconnot  and  Raspail  have  shown  that  solid  animal  fals  are  composed  of  vury  small, 
microscopic,  partly  polygonal,  partly  renifonn  particles,  which  are  connected  together 
by  very  thin  membranes.  These  may  be  ruptured  by  mechanical  means,  then  separated 
by  triturating  the  fresh  fats  with  cold  water,  and  passing  the  unctuous  matter  througb 
a  sieve.  The  particles  float  in  the  water,  but  eventually  collect  in  a  white  granulai 
crj'stalline  appearance,  like  starch.  Each  of  them  consists  of  a  vesicular  integument,  of 
the  nature  of  stearine,  and  an  interior  fluid  like  elaine,  which  aHerwards  exudes.  Th€ 
granules  float  in  the  water,  but  subside  in  spirits  of  wine.  When  digested  in  strong 
alcohol,  the  liquid  part  dissolves,  but  the  solid  remains.  These  particles  diflfer  in  shape 
and  size,  as  obtained  from  different  animals ;  those  of  the  calf,  ox,  sheep,  are  polygonal, 
^"*™  5o  ^°  F5  0^  ®^  **"  '"^^  *"  diameter;  those  of  the  sow  are  kidney-shaped,  and  from  JL 
*°  1 00 '  *^°*^  of  man  are  polygonal,  and  from  JL  to  i-;  those  of  insects  are  spherical, 
and  at  most  .^-1—  of  an  inch. 

Fats  all  melt  at  a  temperature  much  under  212*  F.  When  strongly  heated  with  con- 
tact of  air,  they  diffuse  white  pungent  fumes,  then  blacken,  and  lake  fire.  When  sub- 
jected to  distillation,  they  afford  a  changed  fluid  oil,  carbureted  hydrogen,  and  the  other 
products  of  oily  bodies.  Exposed  for  a  certain  time  to  the  atmosphere,  they  become 
rancid,  and  generate  the  same  fat  acids  as  they  do  by  saponification.  In  their  fresh 
state  they  are  all  composed  principally  of  stearine,  margarine,  and  oleine,  with  a  little 
coloring  and  odorous  matter ;  and,  in  some  species,  hircine,  from  the  goat ;  phocenine, 
from  the  dolphin  ;  and  butyrine,  from  butter.  By  subjecting  them  to  a  great  degree  ol 
cold,  and  compressing  them  between  folds  of  blotting  paper,  a  residuum  is  obtained,  con- 
sisting chiefly  of  stearine  and  margarine ;  the  latter  of  which  may  be  dissolved  out  by 
oil  of  turpentine. 

Beef  and  Mutton  Suet. — ^When  fresh,  this  is  an  insipid,  nearly  inodorous  fat,  of  a  firm 
consistence,  almost  insoluble  in  alcohol,  entirely  so  if  taken  from  the  kidneys  and  mesen- 
teric web  of  the  ox,  the  sheep,  the  goat,  and  the  stag.  It  varies  in  its  whiteness,  con- 
sistence, and  combustibility,  with  the  species  and  health  of  the  animals.  That  of  the 
sheep  is  very  white  and  very  solid.  They  may  all  be  purified  in  the  manner  above  de- 
scribed. Strong  sulphuric  acid  developes  readily  the  acid  fats  by  stirring  it  through 
melted  suet.  Alkali,  by  saponification,  give  rise  at  once  to  the  three  acids, — the  stearic, 
margaric,  and  oleic.  Beef  suet  consists  of  stearine,  margarine,  and  oleine ;  mutton  and 
goat  suet  contain  a  little  hircine.  The  specific  gravity  of  the  tallow  of  which  common 
candles  are  made  is,  by  my  experiments,  0-936.  The  melting  point  of  suet  is  from  98* 
to  104°  F.  The  proportion  of  solid  and  fluid  fat  in  it  is  somewhat  variable,  but  the  for- 
mer is  in  much  larger  proportion.  Mutton  suet  is  soluble  in  44  parts  of  boiling  alcohol, 
of  0*820 ;  beef  suet  in  44  parts.  Marrow  fat  consists  of  76  of  stearine,  and  24  of  oleine ; 
it  melts  at  115°  F. 

Hog's-lard  is  soft,  fusible  at  81®  F.,  convertible,  by  an  alkaline  solution,  into  a  stearate, 
margarate,  oleate,  and  glycerine.  Its  sp.  grav.  is  0*938,  at  50°  F.  It  consists  of  62  of 
oleine,  and  38  of  stearine,  in  100  parts. 

Goose-fat  consists  of  68  oleine  and  32  stearine. 

Butter,  in  summer,  consists  of  60  of  oleine  and  40  of  stearine ;  in  winter,  of  35  of 
oleine,  and  65  of  stearine;  the  former  substance  being  yellow,  and  the  latter  whito. 
Il  differs,  howe^ier,  as  produced  from  the  milk  of  diflerent  cows,  and  also  according  to 
their  pasture. 

The  ultimate  constituents  of  stearine,  according  to  Chevreul,  are  79  carbon,  11*7 
hydrogen,  and  9*3  oxygen,  in  100  parts. 

1,294,009  cwts.  of  the  tallow  imported  in  1837  were  retained  for  internal  consumption* 
See  Margarine,  Oleine,  Soap,  Stearine. 

The  following  statement  is  given  on  the  authority  of  Braconnot:— 


Fresh  Butter  in  summer 

in  winter 

Hog's  Lard 
Ox  Marrow 
Goose  Fat 
Duck  Fat 
Ox  Tallow 
Mutton  Suet    - 


Oleine. 


60 
87 
62 
24 
68 
72 
26 
26 


Stearine. 


40 
68 
88 

76 
82 

28 
76 

74 


M.  Dnmas  says  that  butter  contains  no  stearine.  The  purification  and  decoloration 
of  fats  have  been  the  object  of  many  patents.  Under  Candle,  Hempel's  process  for 
refining  palm-oil  and  extracting  its  mai^arine  is  described. 

About  30  years  ago,  palm-oil  was  deprived  of  color  to  a  certain  degree  by  mixing 
with  the  melted  oil,  previously  freed  from  its  impurities  by  filtration,  some  dilute  nitric 


acid,  wooden  vessels  beiug  used,  and  the  oil  being  in  a  melted  state.     This  process  was 
both  expensive  and  imperfect     More  lately  whitening  has  been  prescribed  by  means 
of  chromic  ncid,  which,  in  the  act  of  decomposition   into  chromic  oxide,   gives  out 
pxyge".  and  thereby  destroys  vegetable  colors.     One  pound  of  bichromate  of  potash 
in  Rolution  is  to  be  mixed  with  two  pounds  of  strong  sulphuric  acid,  diluted  before- 
hand  with  about  two  gallons  of  water;    and   this  mixture  is  to   be  incorporated    bv 
diligent  stirring  with   2  cwt   of  the  filtered  palm-oil,  at  a  temperature  of  about 
100  F.,  contained  in  a  wooden  vessel.    The  palm-oil  is  afterward  to  be  washed  in 
warm  lime-water,  to  which  some   solution  of  chloride  of  lime  may  be  advantageous!} 
added.     By  this  process,  well  managed,  a  fat  may  be  obtained  from  palm-oil  fit  for 
making  white  soap.     Tallow  may  be  also  blanched  to  a  consideiable  degree  by  a  like 
operation. 

Instead  of  sulphuric  acid,  the  muriatic  may  be  used  to  convert  the  chromic  acid  into 
chromic  oxide  in  the  above  process,  and  thereby  to  liberate  the  blanching  oxygen. 
The  resulting  solution  of  green  muriate  of  chrome  being  freed  from  some  adhering  oil, 
is  to  be  mixed  with  so  much  milk  of  lime  as  just  to  neutralize  the  excess  of  acid  that 
may  be  present.  The  clear  green  muriate  is  then  to  be  decomposed  in  a  separate 
vessel,  by  the  addition  of  well-slaked  and  sifted  lime,  in  some  excess.  The  green  mix- 
ture of  lime  and  chrome-oxide  is  now  to  be  dried,  and  gently  ignited,  whereby  it  is 
converted  into  yellow  chromate  of  lime,  with  some  unsaturated  lime.  This  compound 
being  decomposed  by  dilute  sulphuric  acid,  affords  chromic  acid,  to  be  applied  again  in 
the  decoloring  of  palm-oil,  on  the  principles  above  explained. 

Mr.  Prynne  obtained  a  patent  in  March,  1840,  for  purifying  tallow  for  the  candle- 
maker,  by  heating  it  along  with  a  solution  of  carbonate  of  potash  or  soda  for  8  hours, 
letting  the  whole  cool,  removing  the  tallow  to  another  vessel,  heating  it  by  means  of 
tteam  up  to  206°  F.,  along  with  dry  carbonate  of  potash  (pearlash)  :  letting  this  mix- 
ture cool  very  slowly ;  and  finally  removing  the  tallow  to  a  vessel  enclosed  in  steam,  so 
as  to  expel  any  subsidiary  moisture. — Newton^s  Journal,  xxi.  258. 

A  patent  for  a  like  purpose  was  obtained  in  June,  1842,  by  Mr.  H.  H.  Watson.  He 
avails  himself  of  the  blanching  power  of  oxygen,  as  evolved  from  manganate  of  potash 
(chameleon  mineral),  in  the  act  of  its  decomposition  by  acids,  while  in  contact  with 
the  melted  i'at.  He  prescribes  a  leaden  vessel  (a  well-joined  wooden  tub  will  also 
serve)  for  operating  upon  the  melted  tallow,  with  one  twentieth  of  its  weight  of  the 
manganate,  dissolved  in  water,  and  acidulated  to  the  taste.  The  whole  are  to  be  well 
mixed,  and  gradually  heated  from  150^  up  to  212°  F.,  and  maintained  at  that  tem- 
perature for  an  hour.  On  account  of  the  tendency  of  the  dissolved  manganate  to 
spontaneous  decomposition,  it  should  be  added  to  the  dilute  acid,  mixed  with  the  fat 
previously  melted  at  the  lowest  temperature  consistent  with  its  fluidity. 

Palm-oil  may  be  well  blanched  in  the  course  of  12  hours  by  heat  alone;  if  it  be 
exposed  in  a  layer  of  one  or  two  inches  to  the  air  and  sunshine,  upon  the  surface  of 
water  kept  up  at  nearly  the  boiling  point  by  a  coil  of  steam-pipes  laid  in  the  bottom  of 
a  square  cistern  of  lead  or  wood,  well  jointed. 

Mr.  Wilson,  of  Vauxhall,  has  applied  centrifugal  action  to  the  separation  of  the  more 
liquid  from  the  more  solid  parts  of  fatty  matters,  using  in  preference  tlie  hydro-extractor :i 
used  by  Seyrig  and  Co.,  for  drying  textile  fabrics.  Mr.  Wilson  employs  a  stout  cotton 
twill  in  addition  to  the  wire  grating;  and  in  order  to  avoid  the  necessity  of  digging  the 
concrete  parts,  and  to  prevent  them  from  clogging  the  interstices  for  the  discharge  of 
the  oily  matter,  he  places  the  whole  in  a  bag  8  inches  in  diameter,  and  of  such  length 
that  when  laid  on  the  rotating  machine  against  the  grating  the  two  ends  will  meet. 
The  speed  of  the  machine  must  be  kept  below  that  at  which  stearic  acid  or  stearine 
would  pass;  which  is  known  by  the  limpidity  of  the  expressed  fluid.  To  take  advan- 
tage of  the  liquefying  influence  of  heat,  he  keeps- the  temperature  of  his  room  about  2P 
F.  above  that  of  the  substances  under  treatment. 

^The  improved  fat  and  candle  factory,  called  Price's,  of  which  Mr.  Wilson,  of  Belmont, 
Vauxhall,  seems  to  be  the  main  conductor  and  schemer,  is  mounted  upon  a  colossal 
scale.  It  has  five  separate  works  near  London,  great  plantations  of  cocoa-nut  trees  in 
Ceylon,  with  a  capital  of  about  half  a  million  sterling,  an  annual  division  of  profits  to 
the  atnount  of  50,000/.,  and  it  employs  about  800  work-people,  whose  physical  and  moral 
well-being  is  well  looked  after  by  the  benevolent  manager  of  the  whole  concern.  See 
Candles. 

Tallow  imported  for  home  consumption  in  1850,  1,219,101  cwL ;  in  1851,  1,085,660 
cwt  Gross  amount  of  duty  received,  78,270/.  and  68,035/.  respectively ;  the  duty  being 
\d.  per  cwt  from  British  possessions,  and  1«.  Q>d.  per  cwt  from  foreign  countries. 

Fat  Bleacuing.  By  transmitting  streams  of  atmospheric  air  through  heated  palm- 
oil  and  other  colored  and  odorous  fatty  matters,  they  are  deprived  so  far  of  their 
color  and  smell  as  to  be  capable  of  forming  white  soaps.  Mr.  A  Dunn  obtained  a 
patent  for  this  object  in  1843. 


lit 


S90 


FEATHERS. 


FELTED  CLOTH. 


691 


I' 


FAULTS  {Failles,  Fr.),  in  mining,  are  disturbances  of  the  strata  which  interrupt 
ihe  miner's  operations,  and  put  him  at  fault,  to  discover  where  ihe  vein  of  ore  or  bed  oj 
coal  has  been  thrown  by  the  convulsions  of  nature.  Many  examples  of  faults  are  exhibk 
ited  under  Pitcoal. 

FEATHERS  (Plumesy  Fr. ;  Fedem,  Germ.)  constitute  the  subject  of  the  manufacture 
of  the  Plumassier,  a  name  given  by  the  French  (and  also  the  English)  to  the  artisan  who 
prepares  the  feathers  of  certain  birds  foromaments  to  the  toilet  of  ladies  and  for  military 
men,  and  to  him  also  who  combines  the  feathers  in  various  forms.  We  shall  content  our- 
selves with  describing  the  method  of  preparing  ostrich  feathers,  as  most  others  are  pre- 
pared in  the  same  way. 

Several  qualities  are  distinguished  in  the  feathers  of  the  ostrich ;  those  of  the  male,  in 
particular,  are  whiter  and  more  beautiful.  Those  upon  the  back  and  above  the  wings 
are  preferred ;  next,  those  of  the  wings,  and  lastly,  of  the  tail.  The  down  is  merely  the 
feathers  of  the  other  parts  of  the  body,  which  vary  in  length  from  4  to  14  inches.  This 
down  is  black  in  the  males,  and  gray  in  the  females.  The  finest  white  feathers  of  the 
female  have  always  their  ends  a  little  grayish,  which  lessens  their  lustre,  and  lowers  their 
price.  These  feathers  are  imported  from  Algiers,  Tunis,  Alexandria,  Madagascar,  and 
Senegal;  this  being  the  order  of  their  value. 

The  scouring  process  is  thus  performed : — 4  ounces  of  while  soap,  cut  small,  are  dis- 
solved in  4  pounds  of  water,  moderately  hot,  in  a  large  basin  ;  and  the  solution  is  made 
into  a  lather  by  beating  with  rods.  Two  bundles  of  the  feathers,  tied  with  packthread, 
are  then  introduced,  and  are  rubbed  well  with  the  hands  for  five  or  six  mmutes.  After 
this  soaping  they  are  washed  in  clear  water,  as  hot  as  the  hand  can  bear. 

The  whitening  or  bleaching  is  performed  by  three  successive  operations. 

1.  They  are  immersed  in  hot  water  mixed  with  Spanish  white,  and  well  agitated  in  it; 
•fler  which  they  are  washed  in  three  waters  in  succession. 

2.  The  feathers  are  azured  in  cold  water  containing  a  little  indigo  tied  up  in  a  fine  cloth. 
They  should  be  passed  quickly  through  this  bath. 

3.  They  are  sulphured  in  the  same  way  as  straw  hats  are  (See  Souhuring)  ;  they  arc 
then  dried  by  hanging  uiwn  cords,  when  they  must  be  well  shaken  from  time  to  time  to 
open  the  fibres. 

The  ribs  are  scraped  with  a  bit  of  glass  cut  circularly,  in  order  to  render  Ihero  very- 
pliant.  By  drawing  the  edge  of  a  blunt  knife  over  the  filaments  they  assume  the  curly 
form  so  much  admired.  The  hairs  of  a  dingy  color  are  dyed  black.  For  20  pounds 
of  feathers,  a  strong  decoction  is  made  of  25  pounds  of  logwood  in  a  proper  quantity  of 
water.  After  boiling  it  for  6  hours,  the  wood  is  taken  out,  3  pounds  of  copperas  are 
thrown  in ;  and,  after  continuing  the  ebullition  for  15  or  20  minutes,  the  copper  is  taken 
from  the  fire.  The  feathers  are  then  immersed  by  handfuls,  thoroughly  soaked,  and  worked 
about ;  and  left  in  for  two  or  three  days.  They  are  next  cleansed  in  a  very  weak  alkaline 
ley,  and  soaped  three  several  times.  When  they  feel  very  soft  to  the  touch,  they  must 
be  rinsed  in  cold  water,  and  afterwards  dried.  While  feathers  are  very  difficult  to  dye 
a  beautiful  black.  The  acetate  of  iron  is  said  to  answer  better  than  the  sulphate,  as  a 
mordant. 

For  dying  other  colors,  the  feathers  should  be  previously  well  bleached  by  the  action 
of  the  sun  and  the  dew ;  the  end  of  the  tube  being  cut  sharp  like  a  toothpick,  and  the 
feathers  being  planted  singly  in  the  grass.  After  fifteen  days'  exposure,  they  are  cleared 
with  soap  as  above  described. 

Rose  color  or  pink,  is  given  with  safflower  and  lemon  juice. 

Deep  red,  by  a  boiling  hot  bath  of  Brazil  wood,  after  aluming. 

Crimson.    The  above  deep  red  feathers  are  passed  through  a  bath  of  cudbear. 

Prune  de  Monsieur.     The  deep  red  is  passed  through  an  alkaline  bath. 

Blues  of  every  shade,  are  dyed  with  the  indigo  vat. 

Yellow ;  after  aluming,  with  a  bath  of  turmeric  or  weld. 

Other  lints  may  be  obtained  by  a  mixture  of  the  above  dyes. 

Feathers  have  some  more  useful  employments  than  the  decoration  of  the  heads  of 
women  and  soldiers.  In  one  case,  they  supply  us  with  a  soft  elastic  down  on  which  wc 
can  repose  our  wearied  frames,  and  enjoy  sweet  slumbers.  Such  are  called  bed  feathers. 
Others  are  employed  for  writing,  and  these  are  called  quills. 

Goose  feathers  are  most  esteemed  for  beds,  and  they  are  best  when  plucked  from  the 
living  bird,  which  is  done  thrice  a  year,  in  spring,  midsummer,  arjl  the  beginning  of 
harvest.  The  qualities  sought  for  in  bed  feathers,  are  softness,  elasticity,  lightness,  and 
warmth.  Their  only  preparation  when  cleanly  gathered  is  a  slight  beating  to  clear 
•way  the  loose  matter,  but  for  this  purpose  they  must  be  first  well  dried  either  by  the  sun 
or  a  stove.  Bleaching  with  lime  water  is  a  bad  thing,  as  they  never  can  be  freed  from 
white  dust  afterwards. 

The  feathers  of  the  eider  duck,  anas  molUssima,  called  eider  down,  possess  in  a  supe- 
rior degree  all  the  good  qualities  of  goose  down.  It  is  used  only  as  a  covering  to  beds, 
and  never  should  be  slept  upon,  as  it  thereby  loses  its  elasticity. 


Quills  for  writing.  These  consist  usually  of  the  feathers  plucked  out  of  the  wind's  of 
geese.  Dutch  quills  have  been  highly  esteemed,  as  the  Dutch  were  the  first  who  hit  upon 
the  art  of  preparing  them  well,  by  clearing  ihem  both  inside  and  outside  from  a  fatty 
humor  with  whieh  they  are  naturally  impregnated,  and  which  prevents  the  ink  from  flow- 
ing freely  along  the  pens  made  with  them.  The  Dutch  for  a  long  time  employed  hot 
cinders  or  ashes  to  attain  this  end ;  and  their  secret  was  preserved  very  carefully,  but  it 
at  length  transpired,  and  the  process  was  then  improved.  A  bath  of  very  fine  sand  mu^t 
be  kept  constantly  at  a  suitable  temperature,  which  is  about  140°  F. ;  into  this,  the  quiU 
end  of  the  feather  must  be  plunged,  and  left  in  il  a  few  instants.  On  taking  them  out 
they  must  be  strongly  rubbed  with  a  piece  of  flannel,  after  which  they  are  found  to  be 
white  and  transparent.  Both  carbonate  of  potash  in  solution  and  dilute  sulphuric  acid 
have  been  tried  to  effect  the  same  end,  but  without  success.  The  yellow  tint  which  gives 
auills  the  air  of  age,  is  produced  by  dipping  them  for  a  little  in  dilute  muriatic  acid,  and 
Ihen  making  them  perfectly  dry.  But  this  process  must  be  preceded  by  the  sand-bath 
operation.     The  above  is  the  French  process. 

QuillK  are  dressed  by  the  London  dealers  in  two  ways;  by  the  one,  they  remain  of  their 
latura  color;  by  the  other,  they  acquire  a  yellow  tint.  The  former  is  called  the  Dutch 
method,  and  the  principal  workman  is  called  a  Dutcher.  He  siis  before  a  small  stove  fire, 
Jnto  which  he  thrusts  the  barrel  of  the  quill  for  about  a  second,  then  lays  its  root  quickly 
Jelow  his  blunt-edged  knife  called  a  hook,  and,  pressing  this  firmly  with  the  left  hand, 
iraws  tl^e  quill  brK.kly  through  with  his  right.  The  bed  on  which  the  quill  is  laid  to  re- 
ceive this  pressure  is  called  the  plate.  It  is  a  rectangular  smooth  lump  of  iron,  about  S 
nches  long,  i|  broad,  and  2^  thick,  which  is  heated  on  his  stove  to  about  the  350th  de- 
jree  i-ahr.  The  hook  is  a  ruler  of  about  15  inches  in  length,  somewhat  like  the  patten- 
caker  s  knife.  Its  fulcrum  being  formed  at  the  one  end  by  a  hook  and  staple,  and  the 
power  of  pressure  being  applied  by  the  hand  at  the  other  end.  The  quill,  rendered  soft 
ma  elastic  by  the  heat,  endures  the  strong  scraping  action  of  the  tool,  and  thus  geU 
stripped  of  Its  opaque  outer  membrane,  without  hazard  of  being  split.  A  skilful  work- 
man can  pass  2000  quills  through  his  liands  in  a  day  of  10  hours. 

They  are  next  cleaned  by  being  scrubbed  by  a  woman  with  a  piece  of  rough  dog-fish 
»Kin,  and  bnally  lied  up  by  a  man  in  one  quarter  of  a  hundred  bundles. 

In  another  mode  of  dressing  quills,  they  are  steeped  a  night  in  decoction  of  turmeric,  to 
stain  them  yellow;  taken  out  and  dried  in  warm  sand  contained  in  a  pot, then  scraped  bv 
the  Dutcher  as  above  described.  The  first  are  reckoned  to  make  the  best  pens,  though 
•he  second  may  appear  more  beautiful. 

Crow  quills  for  draughtsmen,  as  well  as  swan  quills,  are  prepared  in  the  same  way. 

lelnT"  f '"^^'^^'i,^'^^"?  ^e>l-fed  living  birds  have  most  elasticity,  and  are  least  subjelt  fo 

^!^?  r  m""-  T*"^  ^u'  ^'^  '^""'^  P^"^'^^'^'  «^  ^h'*=h  a^e  spontaneously  cast  n  the 
month  .f  May  or  June,  because  they  are  then  fully  ripe.      In  the  goose's  wing  the  five 

aU  Z n  ■"'  If '^"/^  Tu  '"^""""  ^"^  ^^"^'"-^-  The  first  is  ihe  hardest  and  roundest  of 
all  but  ."-e  shortest.  The  next  two  are  the  best  of  the  five.  Thev  are  sorted  into  those 
of  he  I  ight  and  the  left  wing,  which  are  diflerently  bent.  The  heaviest  quills  are,  g^ 
preparation       '  ^^^^^'  steaming  for  four  hours  has  been  proposed  as  a  good 

FECULA  (Fecule,  Fr. ;  Siarkemehl,  Germ.)  sometimes  signifies  corn  flour,  sometimes 
starch  from  whatever  source  obtained.  '  iomeumes 

.^^^^^.^f-'^^.iOr^hose,  Fr  ;  Feldspalh,  Gevm.)  is  a  mineral  crystallizing  in  oblique 
rhomhoidal  prisms,  susceptible  of  two  clivages;  lustre  more  pearly  than  vitreous^ 
spec  grav.  2.39  to  2..58 ;  scratches  glass;  yields  no  water  when  calcined ;  fuble  a! 
Ihe  blowpipe  into  a  white  enamel;  not  aflected  by  acids.  The  liquid  kft  from  it. 
analyt,cal  treatment  with  nitrate  of  baryta,  nitric  acid,  and  carbonate  of  amZn  a^ 
aflords  on  evapora  ion  an  alkaline  residuum  which  precipitates  plalina  from  its  "hSe 
and  appears  from  tins  as  well  as  other  tests,  to  be  potash.  Feldspar  consists  of-sii  c^' 
66-70 ;  alumina  17-50;  potash,  12;  lime,  125;  oxyde  of  iron,  0-75.  Rose.  Th5 
^e\17i'L'rr'r'''"'"''^  "[""•'''  ^"^  •"  '''  decomposed  state  furnishes  the 
CZes.  '  "^  """'^  "'"'^   '''  ^^^   porcelain  and  best  pottery  manu- 

FK LTED  CLOTH  Tliis  woollen  fabric,  made  without  spinning  and  weaving,  was 
made  the  subject  of  a  patent  by  Mr.  T  R.  Williams  in  February,  1850.  A  copious 
d.'scnption  of  the  process  is  given  in  Newton?8  Journal  xxii   1 

Varuhlud  or  Japanned  Felt  is  made  by  imbuing  the  stuff  of  coarse  hat  bodies  with 
di-v.M-  „il,  preparea  by  boiling  50  lbs.  of  linseed  oil  with  white  lead,  litharge,  and 
uu.Ur,  <,t  .>aeh  one  pound.     The  felt  is  to  be  dried  in  a  stove,  and  then  polished  by 
IM..MI.M.  sione.     Five  or  six  coats  of  oil  are  required.     The  surface  is  at  last  varnished 
W  lu'i.  the  ol.ject  IS  intended  to  be  stiflf,  like  visors,  the  fabric  is  to  be  impregnated  first 


692 


FERMENT. 


FERMENTATION. 


693 


of  all  with  flour-paste,  then  stove-dried,  cut  into  the  desired  shape,  next  imbued  with 
the  drying-oil,  and  pumiced  repeatedly;  lastly  placed,  to  the  number  of  20,  in  a  hot 
iron  mould,  and  exposed  to  strong  pressure.  Japanned  hats,  made  in  this  way,  are  sold 
in  France  at  1«.  3c?.  a  piece ;  and  they  will  stand  several  years'  wear. 

FELTING.  {Feutrage,  Fr.;  Mlzen,  Germ.)  is  the  process  by  which  loose  flocks 
of  wool,  and  hairs  of  various  animals,  as  the  beaver,  rabbit,  hare,  Ac,  are  mutually  in- 
terlaced into  a  compact  textile  fabric.  The  first  step  toward  making  felt  is  to  mix,  in 
the  proper  proportions,  the  different  kinds  of  fibres  intended  to  form  the  stuff;  and  then, 
by  the  vibratory  strokes  of  the  bowstring,  to  toss  them  up  in  the  air,  and  to  cause  them 
to  fall  as  irregularly  as  possible,  upon  the  table,  opened,  spread,  and  scattered.  The 
workman  covers  this  layer  of  loose  flocks  with  a  piece  of  thick  blanket  stuff  slightly 
moistened;  he  presses  it  with  his  hands,  moving  the  hairs  backward  and  forward  in 
all  directions.  Thus  the  different  fibres  get  interlaced,  by  their  ends  pursuing  ever 
tortuous  paths ;  their  vennioular  motion  being  always,  however,  root  foremost  As  the 
matting  geti  denser,  the  hand  pressure  should  be  increased  in  order  to  overcome  the  in 
creasing  resistance  to  the  decussation. 

A  first  thin  sheet  of  soft  spongy  felt  being  now  formed,  a  second  is  condensed  upon  it 
in  like  manner,  and  then  a  third,  till  the  requisite  strength  and  thickness  be  obtained. 
These  different  pieces  are  successively  brought  together  disposed  n  a  way  suitable  to  the 
wished-for  article,  and  united  by  continued  dexterous  pressure.  The  slufl"  must  be  next 
subjected  to  the  fulling-mill.     See  Hat  Manufacture. 

FERMENT  (Eng.  and  Fr. ;  Hefe,  Germ.)  is  the  substance  which,  when  added  in  a 
small  quantity  to  vegetable  or  animal  fluids,  tends  to  excite  those  intestine  motions  and 
changes  which  accompany  fermentation.  It  seems  to  be  the  result  of  an  alteration  which 
▼eietable  albumen  and  gluten  undergo  with  contact  of  air  amidst  a  fermenting  mass. 
The  precipitate  or  lees  which  fall  down  when  fermentation  is  finished  consist  of  a  mix- 
ture of  the  fermenting  principle  with  the  insoluble  matters  contained  in  the  ferijented 
liquor,  some  of  which,  like  hordeine,  existed  in  the  worts,  and  others  are  probably  genera- 
ted at  the  time. 

To  prepare  a  pure  ferment,  or  at  least  a  compound  rich  in  that  principle,  the  precipi- 
tate separated  during  the  fermentation  of  a  clear  infusion  of  mall,  commonly  called 
yeast  or  barm,  is  made  use  of.  This  pasty  matter  must  be  washci  in  cold  distilled  water, 
drained  and  squeezed  between  the  folds  of  blotting  paper.  By  this  treatment  it  becomes 
a  pulverulent  mass,  composed  of  small  transparent  grains,  yellowish  gray  when  viewed 
in  the  compound  microscope.  It  contains  mucli  water,  and  is  therefore  soft,  like  moist 
gluten  and  albumen.  When  dried,  it  becomes  like  these  bodies,  translucid,  yellowish 
brown,  horny,  hard,  and  brittle.  la  the  soft  humid  state  it  is  insipid,  inodorous,  in- 
soluble in  water  and  alcohol.  If,  in  this  state,  the  ferment  be  left  to  itself  at  a  tempera- 
ture of  from  60°  to  70'  F.,  but  not  in  too  dry  a  situation,  it  putrefies  with  the  same  phe- 
nomena as  vegetable  gluten  and  albumen,  and  leaves,  like  them,  a  residuum  resembling 
old  cheese. 

At  the  beginning  of  this  change,  particularly  if  the  ferment  be  enclosed  in  a  limited 
portion  of  air,  there  is  an  absorption  of  oxygen  gas  with  a  fivefold  disengagement  of  car- 
bonic acid  gas;  while  acetic  acid  makes  its  appearance  in  the  substance.  When  distilled 
by  itself  it  affords  the  same  products  as  gluten.  Dilute  acids  dissolve  it  very  readily  ; 
and  so  does  potash  with  the  production  of  ammonia,  a  peculiar  circumstance,  for  in  dis- 
solving gluten  the  alkali  causes  no  such  evolution. 

The  property  possessed  by  yeast  of  determining  the  fermentation  of  a  properly  diluted 
solution  of  sugar  is  very  fleeting,  and  is  lost  by  very  trifling  alterations.  It  is  destroyed 
by  complete  desiccation,  and  cannot  be  restored  by  moistening  it  again.  The  attempts 
made  in  London  to  squeeze  out  the  liquid  part  of  yeast  in  bags  placed  in  a  powerful  press, 
and  to  obtain  a  solid  cake,  in  order  to  transport  ferment  to  India,  have  had  but  a  very 
partial  success ;  for  its  virtue  is  so  impaired  that  it  will  rarely  excite  a  perfect  fermenta- 
tion in  the  best  prepared  worts.  The  same  method  is  adopted  in  Germany,  to  send  yeast 
to  only  moderate  distances ;  and  therefore  with  more  advantage. 

If  yeast  be  boiled  for  ten  minutes,  it  loses  the  greater  part  of  its  fermenting  power, 
and  by  longer  boiling  it  becomes  inert. 

When  alcohol  is  poured  upon  yeast,  it  immediately  destroys  its  fermenting  faculties, 
though,  on  filtering  it  off,  it  seems  to  carry  no  remarkable  principle  with  it.  One  thou- 
sandth part  of  sulphuric  acid  equally  deprives  yeast  of  its  peculiar  property,  and  so  does 
a  little  strong  acetic  acid.  All  the  acids  and  the  salts,  especially  those  which  part  readily 
with  their  oxygen,  produce  the  same  efl'ect.  A  very  small  quantity  of  sulphurous  acid, 
or  sulphites,  mustard  powder,  particularly  the  volatile  oil  of  mustard,  and  in  general  the 
volatile  oils  that  contain  sulphur,  as  well  as  the  vegetables  which  yield  them,  such  as 
horse-radish  and  garlic,  all  kill  the  fermenting  agent.  Lastly,  fermentation  is  completely 
•topped  by  a  moderate  depression  of  temperature. 


During  fermentation  the  yeast  undergoes  a  change;  it  loses  the  property  of  causing 
another  wort  to  ferment.  This  change  probably  depends  upon  the  chemical  reaction 
between  the  ferment  and  the  sugar  that  is  decomposed ;  for  a  certain  quantity  of  yeast 
can  effect  the  fermentation  of  only  a  certain  quantity  of  sugar,  and  all  the  sugar 
exceeding  this  quantity  remains  unaltered  in  the  liquor.  It  has  been  concluded  from 
some  rather  loose  experiments,  that  one  part  and  a  half  of  yeast  (supposed  to  be  in  the 
dry  state),  is  adequate  to  the  fermentation  of  a  solution  of  100  parts  of  pure  sugar. 
When  such  a  solution  is  fermented  by  the  precise  proportion  of  yeast,  the  fermenting 
principle  is  exhausted,  for  no  new  yeast  is  formed  in  it.  There  is  a  deposit  indeed  to 
about  half  the  weight  of  the  yeast  employed,  of  a  white  matter  insoluble  in  water, 
which  affords  no  ammonia  by  dry  distillation,  and  is  incapable  of  acting  as  a  ferment 
upon  a  fresh  saccharine  solution. 

Of  all  the  bodies  convertible  into  yeast  during  fermentation,  vegetable  gluten  and 
albumen  possess  the  most  rapid  and  energetic  powers.  But  ordinary  glue,  isinglass, 
animal  fibrine,  curd  or  caseum,  albumine,  urine,  and  other  azotized  substances,  all 
enjoy  the  property  of  causing  a  solution  of  sugar  to  ferment;  with  this  difference, 
that  whilst  yeast  can  establish  a  complete  fermentation  in  less  than  an  hour,  at  a  tem- 
perature of  about  68'-',  the  above  substances  require  several  days,  with  a  heat  of  from 
77°  to  87*^  F,  for  becoming  ferments,  and  for  occasioning  fermentation.  Substance! 
devoid  of  nitrogen  do  not  produce  a  ferment 

FERMENTATION.  (Eng.  and  Fr. ;  Gahrung,  Germ.)  When  organic  substances, 
under  the  influence  of  water,  air,  and  warmth,  are  abandoned  to  the  reciprocal  operation 
of  their  proximate  principles  (sugar,  starch,  gluten,  &c.),  they  are  entirely  changed  and 
decomposed,  so  that  their  ultimate  principles  (oxygen,  hydrogen,  carbon,  and  in  some  cases 
azote)  combine  in  new  proportions,  and  thus  give  birth  to  various  new  compounds.  To 
this  process,  the  general  name  of  fermentation  has  been  given.  These  operations  and 
their  products  differ  according  to  the  differences  of  the  substance?,  and  of  the  circumstan- 
ces in  which  they  are  placed.  The  following  may  be  enumerated  as  sufficiently  distinct 
species  of  fermentation.  1.  The  saccharine  fermentation,  in  which  starch  and  gum  are 
changed  into  sugar.  2.  The  vinous  fermentation,  in  which  sugar  is  converted  into  alco- 
hol. 3.  The  mucilaginous  fermentation,  in  which  sugar  is  converted  into  slime,  instead 
of  alcohol.  4.  The  acetous  fermentation,  in  which  alcohol  and  other  substances  are  con* 
verted  into  vinegar.  5.  The  putrid  fermentation  or  putrefaction,  which  characterizes 
particularly  the  decomposition  of  azotized  organic  substances. 

I.  The  saccharine  fermentation.  When  a  paste  made  by  boiling  one  part  of  starch 
with  twelve  parts  of  water  is  left  entirely  to  itself,  water  merely  being  stirred  in  as  it 
evaporates,  at  the  end  of  a  month  or  two  in  summer  weather  it  is  changed  into  sugar, 
equal  in  weight  to  from  one  third  to  one  half  of  the  starch,  and  into  gum,  equal  to  from 
one  fifth  to  one  tenth,  with  a  residuum  of  starch  paste  somewhat  altered.  This  sac- 
charifying process  advances  much  quicker  through  the  co-operation  of  vegetable  albu- 
mine or  gluten,  acting  as  a  ferment.  If  we  boil  two  parts  of  potato  starch  into  a 
paste  with  twenty  parts  of  water,  mix  this  paste  with  one  part  of  the  gluten  of  wheat 
flour,  and  set  the  mixture  for  8  hours  in  a  temperature  of  from  122*  to  167°  F.,  the 
mixture  soon  loses  its  pasty  character,  and  becomes  by  degrees  limpid,  transparent,  and 
sweet,  passing  at  the  same  lime  first  into  gum,  and  then  into  sugar.  The  remainder 
consists  of  the  unchanged  starch  with  the  altered  gluten,  which  has  become  sour,  and 
has  lost  the  faculty  of  acting  upon  fresh  portions  of  starch.  It  is  probable,  however, 
that  the  sugar  formation  in  the  first  case,  when  the  starch  undergoes  a  spontaneous 
change,  may  be  due  to  the  action  of  a  small  portion  of  gluten  and  albumine  left  in 
the  starch,  since  a  putrefactive  smell  is  eventually  evolved  indicative  of  that  azotized 
matter.  The  gum  into  which  during  this  process  the  starch  is  first  converted,  and  which 
becomes  afterwards  sugar,  is  of  the  same  nature  as  British  gum,  formed  by  the  roasting 
of  starch. 

This  production  of  sugar  takes  place  in  the  germination  and  kiln-drying  of  malt ;  and 
the  mashing  of  the  brewer  as  well  as  the  sweetening  of  bread  in  baking,  rests  upon  the 
same  principles.  In  many  cases  the  vinous  fermentation  precedes  the  saccharification, 
or  accompanies  it ;  the  starchy  parts  of  the  fermenting  mass  changing  into  sugar, 
while  the  previously  formed  sugar  becomes  wine  or  beer.  In  the  sweetening  of  fruits 
by  keeping,  a  similar  process  occurs ;  the  gummy  and  starchy  fibres  become  sugar  from 
the  action  of  the  glutinous  ferment  which  they  contain ;  as  happens  also  to  the  juices  of 
many  fruits  which  sweeten  for  a  little  while  after  they  have  been  expressed. 

The  nature  of  this  susar  formation  through  the  influence  of  gluten  upon  starch,  is  un- 
doubtedly the  same  as  the  conversion  of  starch  into  sugar,  by  boiling  it  with  sulphuric 
acid ;  though  the  whole  theory  of  this  change  is  not  entirely  developed- 

The  most  energetic  substance  for  the  conversion  of  starch  into  sugar,  is  the  malt  of 
barley.      According  to  the  researches  of  Payen  and  Persoz,  the  gum  which  by  thi« 


694 


FERMENTATION. 


FERMENTATION. 


695 


Ai 


process  is  first  formed,  may  be  prevented  from  going  into  sugar,  hy  merely  exposing  it 
to  a  boiling  heat,  and  hence  we  have  it  in  our  power  either  to  make  sugar  or  gum  at 
pleasure.  Of  finely  ground  malt  from  10  to  25  parts  must  be  taken  for  100  parts  of  starch. 
Into  a  pan  placed  in  a  water  hath,  400  parts  of  water  being  warmed  to  from  77*^  to  86^^  F., 
the  ground  malt  must  be  stirred  in,  and  the  temperature  must  be  raised  to  140°.  The  100 
parts  of  starch  must  now  be  added,  and  well  mixed.  The  heat  is  then  to  be  increased 
to  158*^  F. ;  and  be  so  regulated  that  it  shall  not  fall  below  149°,  nor  rise  above  167°. 
In  the  course  of  20  or  30  minutes  the  originally  milky  and  pasty  liquid  will  become 
graduall^r  more  attenuated,  and  eventually  it  will  turn  as  fluid  nearly  as  water.  This 
is  the  point  of  time  in  which  the  starch  has  passed  into  gum,  or  into  the  substance 
lately  denominated  dextrine  by  the  chemists.  Should  this  mucilaginous  matter,  which 
appears  to  be  a  mixture  of  gum  and  a  little  starchy  sugar,  be  wished  for  in  that  state, 
the  temperature  of  the  liquid  must  be  suddenly  raised  to  the  boiling  pointy  whereby 
the  further  action  of  the  malt  upon  it  is  stopped.  But  on  the  other  hand,  if  sugar 
be  desired,  then  the  temperature  mtist  be  steadily  maintained  at  from  158°  to  167° 
*or  three  quarters  of  an  hour,  in  which  time  the  greater  Dart  of  the  starch  will  have 
become  sugar,  and  from  the  evaporation  of  the  fluid  a  starchy  syrup  will  be  obtained, 
entirely  similar  to  that  procurable  by  the  action  of  very  dilute  sulphuric  acid  upon 
itarch. 

gagar,  and  from  the  evaporation  of  the  fluid  a  starchy  sirup  will  be  obtained,  entirely 
similar  to  that  procurable  by  the  action  of  verj-  dilute  sulphuric  acid  upon  starch. 

The  substance  which  operates  this  saccharine  change,  or  the  appropriate  yeast  of  the 
sugar  fermentation,  which  had  been  previously  imagined  to  be  a  residuum  of  gluien  or 
vegetable  albumen  in  the  germinated  grain,  has  been  traced  by  Payen  and  Persoz  to  a 
peculiar  proximate  vegetable  principle  called  by  them  diastase.     This  substance  is  gen- 
erated during  the  germination  of  barley,  oats,  and  wheat,  and  may  be  obtained  separate./ 
by  infusing  the  ground  malt  in  a  small  quantity  of  cold  water,  straining  ofl*  the  liquor, 
then  filtering  it,  and  heating  the  clear  solution  in  a  water-bath  to  the  temperature  of 
158°  F.     The  greater  part  of  the  vegetable  albumen  is  thus  coagulated,  and   must  be 
separated  by  a  fresh  filtration;  the  liquid  is  afterwards  treated  with  alcohol  as  long  as 
the  flocculent  precipitate  of  diastase  falls.      In  order  to  purify  it  still  more  complelely 
from  the  azotized  matter,  it  may  be  once  more  dissolved  in  water,  and  again  precipitated 
by  alcohol.     When  dried  at  a  low  temperature,  it  appears  as  a  white  solid,  which   con- 
tains no  azote,  is  insoluble  in  strong  alcohol,  but  dissolves  in  weak  alcohol  and  water. 
Its  solution  is  neutral  and  tasteless ;  and  if  left  to  itself,  it  changes  spontaneously,  sooner 
or  later,  according  to  the  degree  of  warmth,  and  becomes  sour.     At  the  temperature  of 
from  149°  to  168°,  it  has  the  property  of  converting  starch  into  gum  or  dexirinc,  and 
sugar;  and,  when  sufficiently  pure,  it  does  this  with  such  energy,  that  one  pari  of  it  is 
capable  of  saccharifying  2000  parts  of  dry  starch.     It  acts  the  more  rapidly  the  larger 
its  proportion.     Whenever  the  solution  of  diastase  with  starch  or  dextrine  has  beec 
heated  to  the  boiling  point,  it  loses  the  property  of  transforming  these  substances.     One 
hundred  parts  of  well  malted  barley  appear  to  contain  about  one  part  of  this  new  body. 
2.  Tke  Vinous  Fermentation. — In  this  fermentation  the  sugar  existing  in  watery  solu- 
tion is,  by  the  operation  of  the  ferment  or  yeast,  converted  into  alcohol,  with  disengage- 
ment of  carbonic  acid  gas.    If  we  dissolve  one  part  of  pure  sugar  in  ten  parts  of  water, 
and  leave  the  solution  in  a  temperature  of  from  68°  to  77°  F.,  which  is  that  iik>sI  favor- 
able to  fermentation,  it  will  remain  unaltered.    But  if  we  stir  into  that  solution  some  beer 
yeast,  the  phenomena  of  fermentation  soon   appear  in  the  above  circumstances  ;  for  car- 
bonic acid  gas  is  evolved,  with  intestine  movements  of  the  liquid,  and  an  increase  of  its 
temperature.   A  body  of  yeast  rises  to  the  surface,  and  exhibits  a  continual  formation  and 
rupture  of  air  bubbles.     At  length  the  sugar  being  in  a  great  measure  decomposed,  the 
motions  cease,  the  liquor  becomes  clear,  and  instead  of  being  a  sirup,  it  is  now  a  dilute 
alcohol.    The  yeast  has  by  this  time  fallen  to  the  bottom  in  a  somewhat  compact  form, 
and  of  a  whitish  color,  deprived  of  the  property  of  exciting  fermentation  in  fresh  sirup, 
provided  no  undue  excess  of  it  was  added  at  first,  for  that  alone  would  remain  elfective. 
Experience  shows  that  for  the  conversion  of  a  determinate  quantity  of  sugar  by  fermen- 
tation, a  determinate  quantity  of  yeast  is  necessary,  which  has  been  estimated  at  abou; 
1|  per  cent,  in  the  dry  state.     When  the  yeast  has  been  decomposed  by  fermenting  its 
definite  proportion  of  sugar,  it  loses  its  fermentable  properly,  and  leaves  the  excess  of 
sugar  unaffected,  forming  a  sweet  vinous  solution.    The  same  thing  happens  if  the  yeast 
be  separated  from  the  wort  by  a  filler  in  the  progress  of  the  fermentation,  for  then  all 
intestine  motion  speedily  stops,  although  much  saccharine  matter  remains. 

In  the  juices  of  sweet  fruits,  of  grapes,  for  example,  the  ferment  is  intimately  asso- 
ciated with  the  sugar.  It  is  at  first  soluble  and  inactive,  till  it  absorbs  oxygen  from  the 
atmosphere,  whereby  it  becomes  an  operative  ferment,  but,  at  the  same  time,  insoluble, 
so  as  to  precipitate  at  the  end  of  the  process.  When  the  expressed  juice  of  the  grape, 
or  mtutf  is  enclosed  in  ^  vessel  out  of  contact  of  air,  and  there  subjected  to  the  heat  of 


boiling  water,  the  small  portion  of  oxygen  present  is  rendered  inactive,  and  the  liquor  ex- 
periences no  fermentative  change.  If  the  grapes  be  squeezed  in  an  atmosphere  deprived 
of  oxygen,  and  confined  in  the  same,  the  juice  will  also  remain  unaltered.  Recently  ex* 
pressed  grape  juice  is  limpid,  and  manifests  the  commencement  of  fermentation  by  the 
separation  of  the  yeasty  substance,  which  can  take  place  only  with  access  of  air.  The 
Bolution  becomes  turbid  after  a  certain  time,  gas  begins  to  be  evolved,  and  the  separated 
ferment  decomposes  the  sugar.  At  the  end  of  the  process  the  yeast  collects  at  the  bot- 
tom of  the  vessel,  usually  in  larger  quantity  than  was  suflicient  to  complete  the  fermen- 
tation ;  and  hence  a  considerable  portion  of  it  possesses  still  the  fermentative  faculty. 
The  fermentation  itself,  when  once  begun,  that  is,  whenever  the  yeasty  particles  arc 
eiolvedand  float  in  the  liquid,  for  which  evolution  a  very  minute  quantity  of  oxygen  is 
suflicient,  is  thenceforth  independent  of  the  contact  of  air,  and  goes  on  as  well  in  close 
as  in  open  vessels ;  so  that  the  production  of  alcohol  and  carbonic  acid  depends  solely 
upon  the  mutual  reaction  of  the  ferment  and  the  sugar. 

The  yeast,  which  may  be  obtained  tolerably  pure  from  a  fine  infusion  of  malt  in  a 
state  of  fermentation,  after  being  washed  with  cold  water  to  separate  the  soluble,  gummy, 
and  saccharine  matter,  and  after  being  pressed  between  fclds  of  blotting  paper,  consti- 
tutes a  pulverulent,  grayish  yellow,  granular  substance,  destitute  of  both  taste  and  smell, 
insoluble  both  in  water  and  alcohol.  Cold  water  dissolves,  indeed,  only  ^^y  and  boiling 
water  very  little  more. 

The  essentially  operative  constituent  of  yeast  is  a  peculiar  azotized  matter,  which  m 
the  wine  vat  is  mixed  with  some  tartar  and  other  salts,  and  in  the  beer  tun  with  gum, 
starch,  &c.  This  animalized  substance  may  be  obtained  in  a  separate  slate,  according 
to  Braconnot,  by  acting  upon  the  washed  yeast  powder  with  a  weak  ley  of  carbonate  oi 
potash,  and  by  decomposing  the  solution  wiih  vinegar,  whereby  the  matter  is  thrown 
down  in  a  gelatinous  form.  The  substance  thus  obtained  is  insoluble  in  cold  water 
and  alcohol,  but  dissolves  readily  in  verj'  dilute  alkaline  leys,  and  even  in  lime  water 
When  diflfused  through  water,  it  assumes  a  homogeneous  aspect,  as  if  it  were  really 
dissolved ;  but  when  this  mixture  is  heated,  the  animalized  matter  coagulates,  and 
separates  in  thick  flocks.  In  this  state  it  has  lost  its  former  properties,  being  no  longer 
soluble  in  alkaline  leys,  even  when  concentrated.  Acids  exercise  no  solvent  power  over 
this  peculiar  matter ;  they  precipitate  it  from  its  solutions,  as  do  also  the  earthy  and 
metallic  salts,  which,  moreover,  combine  with  it.  This  is  also  the  case  with  tannin. 
The  combination  of  the  ferment  stuff  with  acids  increases  the  stability  of  its  constitution, 
and  counteracts  its  tendency  to  influence  solutions  of  sugar.  These  proi)erlies  of  the 
operative  principle  of  yeast  explain  many  of  the  phenomena  of  fermentation,  as  we  shall 
presently  see. 

The  animalized  matter  of  yeast  resembles  gluten,  albumen,  caseum,  and  other  azotized 
substances ;  if  any  one  of  these  be  put  into  a  saccharine  solution  ready  for  fermentation, 
it  will  begin  to  operate  a  change,  when  aided  by  warmth  and  time,  if  it  be  previously 
decomposed  in  some  measure  to  facilitate  its  influence ;  or  if  these  substances  be  brought 
into  a  slightly  putrescent  state  beforehand,  they  will  cause  more  speedy  fermentation. 
Thus  white  of  egg,  when  added  to  saccharine  liquors,  requires  a  period  of  three  weeks, 
with  a  temperature  of  96°  F.,  before  it  will  excite  fermentation ;  afterwards  the  excess 
of  the  albumen  forms  a  precipitate  which  may  be  used  instead  of  yeast  upon  other  sweet 
worts.  The  rapidity  with  which  such  azotized  substances  are  capable  of  being  converted 
into  ferments  of  more  or  less  purity  and  power  is  very  variable ;  vegetable  gluien  and 
albumen  being  best  fitted  for  this  purpose.  This  conversion  is  accelerated  when  the 
sweet  liquor  in  which  the  substance  is  diffused  or  dissolved  has  already  begun  to  ferment; 
whence  it  appears  that  the  presence  of  carbonic  acid  gas,  combined  with  the  liquor,  is 
here  of  singular  influence.  Upon  it,  in  fact,  the  formation  and  elimination  of  the  yeast 
in  fermenting  liquors  depend. 

A  solution  of  pure  sugar,  which  has  been  made  to  ferment  by  the  addition  of  yeast, 
furnishes  no  new  yeast ;  but  there  remains  after  the  process  a  portion  of  the  yeast  origi- 
nally mixed,  in  an  altered  inoperative  condition,  should  its  quantity  have  been  exactly 
adequate  to  the  decomposition  of  the  sugar,  or  in  an  operative  state,  should  the  quantity 
have  been  originally  excessive. 

But  if  the  fermentable  liquor  contains  vegetable  albumen  and  gluten,  as  is  commonly 
the  case  with  the  sweet  juices  of  fruits  and  beer  worts,  these  substances  become  clianged 
into  ferments  in  the  course  of  the  fermentation  induced  by  the  yeast,  and,  being  super- 
fluous, so  to  speak,  for  that  particular  process,  they  remain  entire  at  the  end,  and  may  be 
collected  for  use  in  other  operations. 

Upon  this  principle  is  founded  the  increased  production  of  yeast,  and  the  manufacture 
of  what  has  been  called  artificial  barm,  in  which  the  fermentation  is  conducted  chiefly 
with  a  view  to  the  formation  of  yeast.  To  the  fermenting  mass,  those  kinds  of  meal  are 
•dded,  which  abound  in  albumen  and  gluten,  as  barley,  beans,  or  wheat,  for  instance ; 


696 


FERMENTATION. 


i>'  t. 


It 


and  the  process  is  similar  to  the  production  of  a  great  lump  of  leaven,  from  the  action 
of  a  small  piece  of  it  upon  dough.  The  following  prescription  will  illustrate  this  subject. 
Take  three  ounces  of  bean  flour,  add  to  it  five  quarts  of  boiling  water,  and  boil  th« 
mixture  for  half  an  hour.  Pour  the  decoction  into  a  vessel,  and  stir  into  it,  while  hot, 
56  ounces  of  wheaten  flour.  After  the  mixture  cools  to  the  temperature  of  54°  F.,  add 
to  it  about  two  quarts  of  beer  barm,  stirring  the  whole  well  together.  About  24  hours 
after  the  commencement  of  the  fermentation,  incorporate  with  the  mixture  1 12  ounces  of 
barley  or  bean  flour,  till  it  becomes  a  uniform  dough,  which  must  be  thoroughly  kneaded, 
rolled  out  into  cakes  about  an  inch  thick,  and  cut  into  pieces  of  the  size  of  a  dollar. 
These  cakelets  must  be  dried  upon  laths  in  the  sun  in  favorable  weather,  and  then  put 
up  in  a  dry  situation.  For  use,  one  of  these  discs  is  to  be  broken  into  pieces,  laid  in 
warm  water,  and  set  in  a  warm  place  during  12  hours.  The  soft  mass  will  then  serve 
the  purpose  of  beer  yeast. 

Or  we  may  mix  equal  parts  of  barley  malt,  wheat  malt,  and  crushed  rye,  pour  water 
at  the  temperature  of  122°  F.  over  them  into  a  tub  till  it  stand  a  span  above  their  sur- 
face;  then  stir  well  together,  and  allow  the  whole  to  remain  at  rest  for  a  few  hours, 
till  it  cools  to  about  65°  F.  We  must  now  add  for  each  pound  of  the  mingled  meals, 
a  quarter  nf  an  ounce  of  beer  barm.  The  tub  must  be  then  covered,  and  preserved  at 
a  temperature  of  63°  F.  The  husks,  as  they  begin  lo  rise  to  the  surface,  in  consequence 
of  the  fermentation,  must  be  taken  ofl"  and  squeezed  through  a  cloth  over  the  vessel. 
Wlien  the  meal  comes  afterwards  to  subside  to  the  bottom,  the  whole  musi  be  strained 
Ihrough  a  canvass  bag,  and  freed  from  the  superfluous  moisture  by  squeezin-,  The  bag 
with  its  doughy  mass  must  next  be  surrounded  with  dry  ashes,  lo  remove  the  remaining 
humidity,  and  to  arrest  any  further  fermentation.  This  consistent  ferment  may  be  tised 
instead  of  beer  yeast. 

It  is  difficult  to  prepare  an  artificial  yeast  without  barm.  The  best  process  for  this 
purpose  is  the  followins.  Take  five  parts  of  honey,  one  part  of  powdered  tartar,  and 
sixteen  parts  of  wheat  or  barley  malt,  stir  the  whole  in  water  of  the  temperature  of  122* 
F.,  and  place  in  a  fermenting  heat;  when  the  yeast  will,  as  usual,  be  eliminated. 

The  change  which  gluten  or  vegetable  albumen  undergoes  in  the  different  kinds  of 
meal,  when  it  becomes  a  ferment,  consists  apparently  in  an  oxydation,  since  analysis 
shows  that  this  ferment  contains  more  oxygen  than  gluten  does. 

It  has  been  already  stated  that  yeast  in  its  liquid  condition  readily  putrefies,  and 
becomes  altogether  useless  for  the  process  of  fermentation.  In  order  to  preserve  it  for 
some  time,  it  must  be  dried  to  such  a  degree  as  to  resist  spontaneous  decomposition 
without  losing  its  fermentative  faculty;  but  completely  dried  yeast  loses  that  properly, 
and  does  not  recover  it  by  being  again  moistened.  Beer  barm  may  be  dried  after  being 
washed  sevei'al  times  with  cold  water,  till  the  last  quantity  comes  off  clear;  but  the  in- 
soluble portion  must  be  allowed  to  settle  fully  before  the  water  is  poured  away  from  it. 
The  residuum  being  freed  as  much  as  possible  from  water,  by  drainage  and  pressure 
between  flannel  cloths,  is  to  be  dried  in  the  shade  by  a  current  of  warm  air  as  quickly 
as  possible,  with  the  aid  of  frequent  turning  over.  It  must  be  afterwards  kept  in  dry 
earthen  vessels.  Yeast  may  also  be  preserved  a  short  lime  in  activity  by  being  kneaded 
with  as  much  barley  or  wheat  flour  as  it  can  take  up  without  losing  the  doughy  con- 
sistence. Dried  yeast  has,  however,  always  an  impaired  activity.  The  easiest  and  most 
certain  method  of  preserving  yeast  in  its  primitive  power,  is  by  mixing  it,  after  pressure 
in  flannel,  with  as  much  pulverized  sugar  as  will  render  it  dry,  and  putting  up  the  mix- 
ture in  air-tight  vessels.  The  fermentative  power  of  yeast  is  destroyed  by  the  following 
means  :  1 .  as  already  stated,  by  making  it  completely  dry  either  by  the  evaporation  of 
the  water,  or  its  abstraction  by  alcohol ;  2.  by  boiling,  which  if  continued  for  ten  minutes 
renders  yeast  quite  inoperative ;  3.  by  the  action  of  such  substances  as  dissolve  out  its 
essential  constituents;  by  alkalis,  for  instance,  since  the  particles  of  yeast  seem  to  be 
operative  only  in  their  insoluble  granular  state  ;  4.  by  such  substances  as  form  combina- 
tions with  it,  and  thereby  either  alter  its  nature,  or  at  least  increase  the  cohesion  of  its 
constituent  parts,  so  that  they  can  no  longer  operate  upon  sweet  liquors  by  the  decompo- 
sing affinity  of  its  ultimate  particles.  Such  bodies  are  the  acids,  especially  the  mineral 
ones,  tannin  and  most  salts,  particularly  ihe  metallic,  which  unite  with  the  yeast  into  new 
compounds.  The  volatile  oils  which  contain  sulphur  exercise  the  same  paralyzing  influ- 
ence upon  yeast. 

The  circumstances  which  promote,  and  are  necessary  to,  the  vinous  fermentation  are, 
conformably  to  the  above  views,  the  following-.— 1.  The  presence  of  the  proper  quantity 
of  active  yeast,  and  its  proper  distribution  through  the  worts.  If  in  the  course  of  a  slack 
fermentation  the  yeast  subsides  lo  the  bottom,  the  intestine  motions  cease  entirely,  but 
they  may  be  excited  anew  by  stirring  up  the  ingredients,  or  rousing  the  tun,  as  Ihe  brew- 
ers say.  2.  A  certain  degree  of  warmth,  which  should  never  be  less  than  51°  F.,  nor 
more  than  86°  j  the  temperature  of  from  68°  lo  77°  being  the  most  propitious  for  the 


FERMENTATION. 


697 


commencement  and  progress  of  fermentation.  "When  other  circumstances  are  the  same^ 
the  rapidity  of  the  fermentation  is  proportional  to  the  temperature  within  certain 
limits,  80  that,  by  lowering  it,  the  action  may  be  moderated  at  pleasure.  3.  The  fer- 
mentation proceeds  the  better  and  more  equably  the  greater  tl>e  mass  of  fermenting 
liquor,  probably  on  account  of  the  uniformly  high  temperature,  as  well  as  the  uniform 
distribution  of  the  active  particles  of  the  yeast  by  the  greater  energy  of  the  intestine 
movements.  4.  The  saccharine  solution  must  be  sufficiently  diluted  with  water;  when 
too  much  concentrated  it  will  not  ferment  Hence  very  sweet  musts  furnish  wines 
containing  much  undecomposed  sugar.  For  a  complete  fermentative  action,  one  part  of 
sugar  should  be  dissolved  in  ten  parts  of  water. 

Fermentation  maybe  tempered  or  stopped:  1.  by  those  means  which  render  the 
yeast  inoperative,  particularly  by  the  oils  that  contain  sulphur,  as  oil  of  mustard  ;  as 
also  by  the  sulphurous  and  sulphuric  acids.  The  operation  of  the  sulphurous  acid  in 
obstructing  the  fermentation  of  must  consists  partly,  no  doubt,  in  its  absorbing  oxygen, 
whereby  the  elimination  of  the  yeasty  particles  is  prevented.  The  sulphurous  acid, 
moreover,  acts  more  powerfully  upon  fermenting  liquors  that  contain  tartar,  as  grape 
juice,  than  sulphuric  acid.  This  acid  decomposes  the  tartaric  salts,  and  combining 
with  their  bases,  sets  the  vegetable  acid  free,  which  does  not  interfere  with  the  fermen- 
tation; but  the  sulphurous  acid  operates  directly  upon  the  yeast:  2,  by  the  separation 
of  the  yeast,  either  with  the  filter  or  by  subsidence ;  3,  by  lowering  the  temperature  to 
45*^  F.  If  the  fermenting  mass  become  clear  at  this  temperature,  and  be  drawn  off 
from  the  subsided  yeast,  it  will  not  ferment  again,  though  it  should  be  heated  to  the 
proper  pitch. 

The  products  of  vinous  fermentation  are  carbonic  acid  gas,  and  alcohol;  of  whidi  the 
former  escapes  during  the  process,  except  in  the  case  of  the  sparkling  wines,  like  cham- 
paign, that  are  partially  fermented  in  close  vessels.  The  alcohol  remains  in  the  ferment- 
ed liquor.  100  parts  of  sugar  afford  by  complete  decomposition  nearly  50  parts  of  alco- 
hol. According  to  Thenard,  100  parts  of  sugar  are  converted  into  46*8  parts  of  carbonic 
acid,  and  49-38  of  alcohol ;  besides  3*82  parts  of  carbon  otherwise  employed,  which  the 
sugar  contained,  above  what  is  present  in  the  former  two  products.  This  chemist  found 
in  the  fermented  liquor  4  per  cent,  of  an  extractive  matter,  soluble  in  water,  and  having 
an  acidulous  reaction,  to  whose  formation,  probably,  that  excess  of  carbon  may  be  neces- 
sary. In  what  way  the  action  of  the  yeasty  particles  upon  the  saccharine  substance  is 
carried  on  in  the  vinous  fermentation,  or  what  may  be  the  interior  working  of  this  pro- 
cess, is  not  accurately  understood.  The  quantitative  relation  of  the  carbonic  acid  and 
alcohol  to  the  sugar  is  pretty  well  made  out ;  but  the  determination  of  the  ultimate  prin- 
ciples of  the  ferment  itself,  before  and  after  the  vinous  change,  and  of  the  residuum  dis- 
solved in  the  fermented  liquor,  has  not  been  well  ascertained.  It  is  probable  that  the 
yeast  undergoes  in  the  process  a  similar  decomposition  to  that  of  the  putrefactive,  and 
that  its  elementary  constituents  enter  into  new  combinations,  and  abstract  so  much  carbon 
and  hydrogen  from  the  sugar,  that  the  remainder,  amounting  to  96  per  cent,  of  the  whole, 
may  constitute  one  atom  of  alcohol  and  one  of  carbonic  acid. 

3.  The  slimy  or  glutinous  fermentation. — This  process  takes  place  in  weak  solutions 
of  sugar,  at  ordinary  fermenting  temperatures,  where,  from  defect  of  good  yeast,  the 
vinous  fermentation  cannot  proceed.  In  such  circiimstances,  from  one  part  of  sugar,  one 
third  part  of  gum  is  formed.  According  to  Desfosses,  however,  100  parts  of  sugar  afford 
109-48  of  cum  or  slime.  This  is  formed  when  one  part  of  sugar  is  dissolved  in  twenty 
parts  of  water,  which  had  been  previously  boiled  with  washed  barm  or  gluten,  and  then 
filtered.  The  process  proceeds  slowly  and  quietly,  equally  well  in  close  vessels,  as  with 
contact  of  air,  and  continues  at  ordinary  temperatures  about  12  days ;  but  it  goes  on  more 
rapidly  and  completely  at  the  heat  of  from  77°  to  86°  F.  A  small  quantity  of  hydrogen 
and  carbonic  acid  gas  is  disengaged,  in  the  proportion  of  two  to  one  by  volume.  The 
fermented  liquor  becomes  turbid,  and  assumes  a  tough  thready  appearance,  like  a  decoc- 
tion of  linseed.  A  small  addition  of  sulphuric  or  sulphurous  acid,  of  muriatic  acid  and 
alum,  or  of  tannin,  impedes  this  species  of  fermentation  ;  because  these  substances  com- 
bine, as  in  the  vinous  fermentation,  with  the  ferment  into  an  insoluble  precipitate,  unsus- 
ceptible of  further  change.  In  many  wines,  especially  when  bottled,  this  slimy  fermenta- 
tion occurs,  and  occasions  their  ropiness,  which  may  be  best  remedied  or  prevented  by 
the  addition  of  as  much  tannin  as  will  precipitate  the  dissolved  mucous  matter.  This 
species  of  fermentation  attacks  very  rapidly  the  rinsing  waters  of  the  sugar  refiner, 
which  always  contain  some  fermentative  gluten.  A  little  alum  is  the  best  preventive 
in  this  case,  because  it  precipitates  the  dissolved  ferment. 

4.  Tii£  acetous  or  sour  fermentation. — In  this  process,  alcohol,  more  or  less  dilute,  is 
resolved  into  water  and  vinegar  in  consequence  of  the  operation  of  the  ferment  j  oxy- 


; 


•  I 


I 


698 


FERMENTATION. 


dizement  of  the  alcohol  being  effected  by  the  oxygen  of  the  atmospherical  air.  Tlie 
requisites  of  this  process  have  been  already  detailed  under  the  article  Acktic  Acid. 
They  are  the  presence  of  atmospherical  air ;  alcohol  diluted  to  a  certain  degree  with 
water  ferment  or  yeast,  and  a  temperature  above  66°  F.  The  most  active  ferments  are 
such  substances  as  have  already  passed  into  the  acetous  state;  hence  vinegar,  especially 
when  it  contains  some  yeasty  particles,  or  is  combined  with  porous  and  spongy  bodies, 
so  as  to  multiply  its  points  of  contact  with  the  vinous  liquor,  is  particularly  powerful. 
Common  yeasl  may  also  be  employed  for  vinegar  ferments,  if  it  be  imbued  with  a  little 
vinegar,  with  leaven,  crusts  of  bread  soaked  in  vinegar,  the  stalks  and  husks  of  grapes, 
sawdust  and  shavings  of  beech  or  oak  impregnated  with  vinegar,  or  the  slimy  sediment 
of  vinegar  casks  called  mother ;  all  of  which  operate  as  ferments  chiefly  in  consequence 
of  the  vinegar  which  they  contain.  The  inside  shavings  of  the  staves  of  vinegar  tuns 
act  on  the  same  principle. 

The  acetous  fermentation  may,  r:oreover,  go  on  along  with  the  vinous  in  the  same 
liquor,  when  this  contains  sugar  as  well  as  alcohol.  Whilst  the  acidification  of  the  alcohol 
is  effected  by  the  absorption  of  oxygen  from  the  atmosphere,  the  sugar  becomes  alcohol 
with  disengagement  of  carbonic  acid,  and  then  passes  into  vinegar.  Since  most  liquors 
intended  for  making  vinegar,  such  as  wine,  juices  of  fruits,  ales,  &c.,  contain  still  a  little 
sugar,  they  disengage  always  a  little  carbonic  acid.  Besides  spirits,  some  other  substan- 
ces, such  as  gum,  the  mucilage  of  plants,  and  starch  paste,  directly  ferment  into  vinegar. 
Sugar  also  seems  to  be  convertible  into  vinegar  without  any  vinous  change.  The  albu- 
minous matter  of  potato  juice,  precipitated  by  vinegar,  serves  as  a  proper  ferment  for 
that  purpose,  when  added  in  its  moist  state  to  weak  sirup.     5.  See  Putrefaction. 

Mr.  William  Black,  in  his  treatise  on  Brewing,  has,  with  much  ingenuity  and  apparent 
truth,  endeavored  to  show  that  the  process  of  fermentation  is  strongly  influenced  by 
electricity,  not  only  that  of  the  atmosphere,  as  has  been  long  known  from  the  circumstance 
if  beer  and  wine  becoming  speedily  sour  after  thunderstorms,  but  the  voltaic,  produced 
by  electric  combinations  of  metals  in  the  fermenting  tuns.  He  therefore  recom- 
mends these  tuns  to  be  made  with  as  little  metallic  work  as  possible,  and  to  be  insulated 
from  the  floor  of  the  brewhouse.  For  the  propriety  of  this  advice  he  adduces  some 
striking  examples.  Wort  which  had  become  stationary  in  its  fermentation,  on  being 
pumped  out  of  square  gyles  imbedded  in  the  floor,  into  casks  placed  upon  wooden 
stillions,  began  immediately  to  work  very  well,  and  gained  about  6  degrees  of^  attenuation 
while  throwing  off  its  yeast.  From  the  stagnation  of  the  process  in  the  gyles,  he  had 
in  the  morning  predicted  an  approaching  thunderstorm,  which  accordingly  supervened 
in  the  course  of  the  evening.  In  further  support  of  his  views  he  instances  the  fact,  that, 
in  dairies  where  the  milk  is  put  into  porcelain  vessels,  and  placed  upon  wooden  shelves, 
it  is  seldom  injured  By  lightning;  but  when  contained  in  wooden  or  leaden  vessels,  and 
placed  upon  the  ground,  it  almost  invariably  turns  sour  in  thunder}  weather.  His 
general  conclusion  i?,  "  that  the  preservation  or  destruction  of  beer  depends  upon  elec- 
tricity ;  and  the  most  certain  mode  of  preservation  is  to  insulate  as  much  as  possible, 
both  the  squares  and  all  other  utensils  or  vessels  connected  with  the  brewing  or  storing 
of  beer." 

Mr.  Black  further  considers  that  unsoundness  of  worts  is  often  the  result  of  electricity 
excited  between  the  mash  tun  and  the  copper. 

Why  is  beer  liable  to  get  spoiled  in  thunder-storms,  though  apparently  well  insulated 
in  glass  bottles  ? 

I  shall  conclude  this  article  with  Mr.  Black's  description  of  the  phenomena  of  beer 
fermentation.  In  every  regular  process  there  are  five  distinct  stages.  In  the  first 
we  see  a  substance  like  cream  forming  all  round  the  edges  of  the  gyle  tun ;  which  ex- 
tends towards  the  centre  until  the  whole  is  creamed  over,  constituting  the  first  change. 
Next  a  fine  curl  appears  like  cauliflower,  which  also  spreads  over  the  square  surfacs, 
and  according  to  the  strength  and  appearance  of  this  curl,  the  quality  of  the  fermenta- 
tion may  be  predicated.  This  he  calls  the  second  stage.  What  is  technically  called 
the  stomach  or  vinous  vapor  now  begins  to  be  smelt,  and  continues  to  gain  strength 
till  the  process  is  concluded.  From  the  vinous  energy  of  this  odor,  and  the  progressive 
attenuation  of  the  wort,  the  vigor  of  the  fermentation  may  be  inferred.  The  experienced 
brewer  is  much  guided  in  his  operations  by  the  peculiarity  of  this  effluvium.  The  third 
change  is  when  the  cauliflower  or  curling  top  rises  to  a  fine  rocky  or  light  yeasty  head; 
and  when  this  falls  down,  the  fourth  stage  has  arrived.  Finally  the  head  should  rise  to 
what  is  called  close  yeastv,  having  the  appearance  of  yeast  all  over.  About  this  period 
the  gas  becomes  so  powerful  as  to  puff  up  occasionally  in  little  bells  or  bladders  about  the 
size  of  a  walnut,  which  immediately  break.  The  bells  should  appear  bright  and  clear. 
If  they  be  opaque  or  whey  colored,  there  is  some  unsoundness  in  the  wort.     The  great 


FERMENTATION. 


699 


point  is  to  add  just  so  much  yeast  as  to  carry  the  fermentation  completely  through 
these  five  changes  at  the  regular  periods. 

The  terra  fermentation  has  been  of  late  extended  t^  several  operations  besides  those 
formerly  included  under  it  The  phenomena  which  it  exhibits  under  these  different 
phases  and  the  changes  which  it  eflTecte  among  the  various  subjects  of  its  operations,  are 
no  less  striking  and  mysterious  in  their  principle  than  important  in  their  application  to 
the  arts  of  life.  Fermentations  are  now  arranged  into  twelve  classes — 1,  the  alcoholic; 
2,  the  glucosic  or  saccharine ;  3,  the  viscous  or  mucous;  4,  the  lactic;  5,  the  ascetic ;  6, 
the  gallic;  7,  thepectic;  8,  the  benzoilic ;  9,  the  sinapic ;  10,  the  ammoniacal ;  11,  the 
putrid  ;  and  12,  the  fatty. 

Fermentation,  in  the  most  general  sense,  may  be  defined  to  be  a  spontaneous  re- 
action, a  chemical  metamorphosis,  excited  in  a  mass  of  organic  matter  by  the  mere 
presence  of  another  substance,  which  neither  extracts  from,  nor  gives  to,  the  matter 
which  it  decomposes  any  thing  whatever.  This  process  requires  the  following  con- 
ditions:— 1.  A  temperature  from  45°  to  9(P  F. ;  2.  Water;  3.  The  contact  of  air; 
4.  The  presence  of  a  neutral  organic  azotized  matter,  in  a  very  small  quantity,  and  of  a 
crystallizable  non-azotized  substance,  in  considerable  quantity.  Tlie  former  is  the 
ferment.,  the  latter  undergoes  fermentation.  In  ordinary  chemical  actions  we  perceive 
one  body  unite  to  another  to  form  a  new  compound  ;  or  one  body  turn  another  out  of 
a  combination,  and  take  its  place,  in  virtue  of  a  superior  aflSnity.  These  effects  are 
foreseen  and  explained  by  the  intervention  of  that  molecular  force  which  governs  all 
chemical  operations,  that  attractive  power  which  unites  the  particles  of  dissimilar 
bodies.  Thus,  also,  in  the  ordinary  phenomena  of  decomposition,  we  perceive  the 
agency  of  heat  at  one  time,  at  another  of  light,  or  of  electricity ;  forces  of  which,  though 
we  are  not  acquainted  with  the  essence,  yet  we  know  the  exact  effect  under  determi- 
nate circumstances.  But  fermentation,  on  the  contrary,  can  be  explained  neither  by 
the  known  laws  of  chemical  affinity  nor  by  the  intervention  of  the  powers  of  light,  elec- 
tricity, or  heat.  Fermentation  reduces  complex  organic  substances  to  simpler  com- 
pounds, thereby  reducing  them  nearer  to  the  constitution  of  mineral  nature.  It  is  an 
operation  analogous,  in  some  respects,  to  that  effected  by  animals  upon  their  vegetable 
food. 

With  a  good  microscope,  any  person  :nay  convince  himself  that  ferment  or  yeast  ii 
an  organized  matter,  formed  entirely  of  globules,  or  of  corpuscles  slightly  ovoid,  from 
the  three  to  the  four  thousandth  part  of  an  inch  in  diameter.  Sometimes  their  surface 
seems  to  have  a  little  tail,  which  has  been  regarded  as  a  bud  or  germ  attached  to  the 
mother  cell.  Whenever  the  fermentation  begins,  the  yeast  does  not  remain  an  instant 
idle.  These  small  round  bodies  become  agitated  in  all  directions,  and  if  the  substance 
undergoing  fermentation  is  mixed  with  an  azotized  matter,  as  in  beer-worts,  the  cor- 
puscles become  larger,  the  small  tails  get  developed,  and  on  acquiring  a  certain  size 
they  separate  from  the  parent  globule,  to  live  by  themselves  and  give  birth  to  new  cor- 
puscles.* In  the  fermentation  of  beer  from  malt,  this  series  of  multiplications  produces 
a  quantity  of  yeast  seven  times  greater  than  what  was  added  at  the  commencement. 
Were  the  above  ingenious  speculations  demonstrated  with  certainty,  we  should  be  led 
to  admit,  in  all  these  phenomena,  actions  truly  vital,  and  a  reproduction  like  that  of 
buds  in  the  vegetable  kingdom.  The  existence  of  a  vital  force  seems  to  be  rendered 
probable  by  the  fact  that  in  incomplete  fermentation,  such  as  that  of  fine  syrup  with  too 
little  yeast,  the  ferment  loses  its  properties  and  powers.  If,  however,  we  add  to  the  so- 
lution of  pure  sugar  an  albuminous  substance,  a  caseous  or  fleshy  matter,  the  devel- 
opment of  yeast  becomes  manifest,  and  an  additional  quantity  of  it  is  found  at  the  end 
of  the  operation.  Thus  with  nourishment,  ferment  engenders  ferment.  It  is  for  this 
reason  that  a  little  fermenting  must,  added  to  a  body  of^  fresh  grape-juice,  excites  fer- 
mentation in  the  whole  mass.  These  effects  are  not  confined  to  alcoholic  fermentation. 
The  smallest  portions  of  sour  milk,  of  sour  dough,  or  sour  juice  of  beet-root,  of  putrefied 
flesh  or  blood,  occasion  like  alterations  in  fresh  milk,  dough,  juice  of  beet-roots,  flesh, 
and  blood.  But  further,  and  which  is  a  very  curious  circumstance,  if  we  put  into  a  li- 
quid containing  any  fermenting  substance,  another  in  a  sound  state,  the  latter  would 
Bufl'er  decomposition  under  the  influence  of^  the  former.  If  we  place  urea  in  presence 
of  beer-yeast,  it  experiences  no  change  ;  while  if  we  add  to  it  sugar-water  in  a  ferment- 
ing state,  the  urea  is  converted  into  carbonate  of  ammonia.  We  thus  possess  two  modes 
of  decomposition,  the  one  direct,  the  other  indirect. 

Although  yeast  has  all  the  appearances  of  an  organized  substance,  it  is  merely  by  anal- 
ogy that  its  multiplication  by  growth  is  assumed,  for  this  is  a  phenomenon  very  difficult 
of  experimental  demonstration.  When  blood,  cerebral  substance,  gall,  pus,  and  such 
like  substances,  in  a  putrid  state,  are  laid  upon  fresh  wounds  in  animals,  vomiting,  de- 

*  M.  Turpin,  M.  Cagniard  Latour,  M.  Qu€venne,  and  Professor  Mitscherlich. 


\* 


700 


FERMENTATION. 


II 


debility,  and  death  soon  anpervene.     The  scratches  from  bones  in  putrid  bodies  have 
been  often  the  causes  of  disease  and  death  to  anatomists     The  poison  in  bad  sausages 
is  of  the  same  class  of  ferments.     In  "Wurtemberg,  where  sausages  are  prepared  from 
very  miscellaneous  matters,  as  blood,  livers,  brains,  and  offal  of  many  other  kinds,  with 
bread,  meal,  salt,  and  spices,  fatal  results  from  eating  them  are  not  uncommon.     Death 
in  these  cases  is  preceded  by  the  gradual  wasting  of  the  muscular  fibre,  and  of  all  the 
like  constituents  of  the  human  body ;  so  that  the  patient  becomes  emaciated,  dries  into 
a  complete  mummy,  and  soon  expires.     The  cadaver  is  stiff  as  if  frozen,  and  is  not 
subject  to  putrefaction.     During  the  progress  of  the  satisage  disease,  the  saliva  becomes 
viscid,  and  emits  an  offensive  smell.     No  peculiar  poison  can  be  detected  by  analysis 
in  the  sausages ;  but  they  are  rendered  wholesome  food  for  animals  by  the  action  of 
alcohol,  or  by  that  of  boiling  water,  which  destroy  the  noxious /owej»  without  acquiring 
it  themselves;  and  thus  decompose  the  putrefactive  ferment  of  the  sausages.     When 
this,  however,  passes  unchanged  through  the  stomach  into  the  circulating  system,  it 
imparts  its  peculiar  action  to  the  constituents  of  the  blood,  operating  upon  it  as  yeast 
does  upon  wort     Poisons  of  a  like  kind  are  produced  by  the  body  itself  in  some 
diseases.      In  piague,  small-pox,  measles,  <fec.,  substances  of  a  peculiar  fermentative 
nature  are  generated  from  the  blood,  which  are  capable  of  inducing  in  the  blood  of  a 
healthy  person  a  decomposition  like  that  of  which  themselves  are  the  subjects.     The 
morbid  virus  reproduces  itself,  and  multiplies  indefinitely,  just  as  the  particles  of  yeast 
do  in  the  fermentation  of  beer.     The  temperature  of  boiling  water,  and  alcohol  applied 
to  matters  imbued  with  such  poisonous  secretions,  renders  their  poison  inert     Many 
acids,  chlorine,  iodine,  bromine,  empyreumalic  oils,  smoke,  creosote,  strong  decoction 
of  coffee,  have  the  same  salutaiy  effect.     All  these  agents  are  known  to  counteract  fer- 
mentation, putrefaction,  and  that  dry  wasting  of  organic  matter  called  eremacausis,  or  slow 
combustion.  It  is  most  deserving  of  remark  that  the  poisons  chemically  neutral  or  alkaline, 
such  as  those  of  small-pox  in  man,  and  of  typhus  ruminantium  in  cows,  lose  their  bane> 
ful  power  when  subjected  to  the  action  of  the  stomach  ;  whereas  that  of  bad  sausages, 
which  is  acid,  resists  the  modifying  power  of  the  digestive  organs. 

Alcoholic  fermentation  has  been  copiously  discussed  in  the  Dictionary.  I  may  here 
add  that  ammonia,  being  a  product  of  that  change  in  solution  of  pure  sugar,  proves  the 
presence  of  azote  in  the  yeast ;  and  that  sulphuretted  hydrogen,  being  made  manifest  in 
the  disengaged  gaseous  products,  by  their  blackening  paper  imbued  with  acetate  of  lead, 
proves  the  presence  of  sulphur.  The  acid  liquor  accompanying  yeast  may  be  washed 
away,  without  impairing  materially  its  fermenting  power,  while  the  acid  so  removed  has 
of  itself  no  such  virtue. 

Yeast,  freed  from  all  soluble  matters  by  water,  alcohol,  and  ether,  contains,  indepen- 
dently of  ashes — carbon,  50*6  ;  hydrogen,  7-3  ;  azote,  15;  oxygen,  sulphur,  and  phospho- 
rous, 27' 1,  in  100  parts.  Viewed  atomically,  yeast  bears  a  close  analogy  to  albumen. 
Like  albuminous  matter,  yeast  takes  a  violet  tint  with  muriatic  acid,  and  it  may  be  re- 
placed as  ferment  by  gluten.  Caseum  (the  curd  of  milk)  and  flesh  operate  the  same 
effect.  All  these  fermentative  powers  have  the  same  globular  appearance  in  the  mi- 
croscope with  yeast.  When  the  activity  of  yeast  has  been  destroyed  by  heat,  &c.,  it 
can  be  restored  by  the  positive  energy  of  the  voltaic  battery,  which  causes  its  combina- 
tion with  oxygen.  The  best  proportion  of  sugar  and  water,  for  exhibiting  the  phenom- 
ena of  fermentation,  is  1  of  the  former  to  3  or  4  of  the  latter,  and  5  parts  of  sugar  to  1 
of  fresh  yeast  may  be  added ;  though  in  the  course  of  fermentation,  100  parts  of  sugar 
do  not  consume  2  parts  of  yeast,  estimated  in  the  dry  state.  The  quickest  fermenting 
temperature  is  from  68^  to  86°.  A  very  little  oil  of  turpentine  or  creosote,  or  of  the 
mineral  acids,  prevents  or  stops  fermentation  completely ;  oxalic  and  prussic  acids  have 
the  same  effect,  as  also  corrosive  sublimate  and  verdigris.  It  has  been  known  from 
time  immemorial  in  Burgundy,  that  a  little  red  precipitate  of  mercury,  when  added  to 
the  must-tun,  stopped  the  fermentation.  All  alkalies  counteract  fermentation,  but  when 
they  are  saturated  it  recommences.  The  first  person  who  described  the  microscopic 
globules  of  yeast  with  precision  was  Desmazieres,  who  arranged  them  among  the  my- 
codermes  (fungus-skinned),  under  the  name  of  mycoderma  cerevisia.  They  have  not 
the  flattened  form  of  the  globules  of  blood,  but  are  rather  egg-shaped.  One  small  black 
point  may  be  seen  on  their  surface,  which,  after  some  days,  is  associated  with  3, 4,  or  5 
others.     Their  average  diameter  is  from  _-J —  to  — I of  an  inch.     Sometimes  more 

5000  4000 

minute  globules  cluster  round  one  of  ordinary  size,  and  whirl  about  with  it,  when  the 
liquor  in  which  the  globules  float  is  agitated. 

Fresh  yeast  loses,  by  drying,  68  parts  in  the  100,  and  becomes  solid,  horny-looking, 
and  semitransparent,  breaking  readily  into  gray  or  reddish  fragments.     With  water,  it 
resumes  immediately  its  pristine  appearance.    When  fresh  yeast  is  triturated  with  itf 
own  weight  of  white  sugar,  it  forms  a  liquid  possessing  the  fluidity  of  oil  of  almonds 
and  a  yellow  color.      The   globules  continue  unchanged,  except  perhaps  becoming 


FERMENTATION. 


701 


eomewhat  smaller.     Yeast  in  the  dry  state  retains  its  fermentative  virtue  for  a  long 

time. 

Saccharine  Fermentation  is  that  by  which  starch  and  dextrine  are  converted  into 
sugar,  as  shown  remarkably  in  the  action  of  diastase  upon  these  bodies.  If  we  mix  2 
parts  of  starch  paste  with  1  part  of  dry  gluten,  and  keep  the  mixture  at  a  temperature 
of  from  122°  to  140°  Fahr.,  we  obtain  a  good  deal  of  sugar  and  dextrine.  Some  lactic 
acid  is  also  formed.  Flour  paste,  long  kept,  spontaneously  produces  sugar  by  a  like 
reaction.     See  Fermentation  in  the  Dictionary. 

Lactic  Fermentatim. — Almost  all  azotized  organic  matters,  after  being  modified  by 
the  contact  of  air,  become  capable  of  giving  rise  to  this  fermentation.  Oxygen  docs 
not  come  into  play,  except  as  the  means  of  transforming  the  animal  substances  into  a 
ferment.  Diastase  and  caseum  are  well  adapted  to  exhibit  this  change.  The  body 
that  is  to  furnish  the  lactic  acid  may  be  any  one  of  the  neutral  vegetable  matters,  pos- 
sessing a  like  composition  with  lactic  acid,  such  as  cane-sugar,  grape  or  potato  sugar, 
dextrine,  and  sugar  of  milk.  All  the  agents  which  stop  the  alcoholic,  stop  also  the 
lactic  fei-mentation  ;  while  diastase  and  caseum  are  its  two  best  exciters.  For  produ- 
cing abundance  of  lactic  acid,  we  have  merely  to  moisten  malt,  to  expose  it  to  the  air 
for  a  few  days,  then  to  triturate  it  with  a  quantity  of  water,  and  leave  the  emulsion  for 
some  days  more  in  the  air,  at  a  temperature  between  67°  and  86°  F.  We  then  saturate 
the  liquor  with  chalk,  afler  having  filtered  it,  and  thereby  obtain  the  lactate  of  lime 
which  may  be  crystallized  in  alcohol,  to  deprive  it  of  the  dextrine  and  earthy  phosphates ; 
and  then  decomposed  by  sulphuric  acid. 

Lactic  jlcid,  formed  from  curd  (caseum),  exhibits  more  remarkable  phenomena.  Tims 
whfn  milk  is  lefl  alone  for  some  time  it  becomes  sour,  and  coagulates.  The  coagulum 
e  formed  of  caseum  and  butter ;  while  the  whey  of  it  contains  sugar  of  milk  and  some 
•alts.  The  coagulation  of  the  caseum  has  been  occasioned  by  the  lactic  acid,  which 
was  generated  in  consequence  of  an  action  which  the  caseum  itself  exercised  upon  thf 
sugar  of  milk.  Thus  with  the  concourse  of  air,  the  caseum  becomes  a  ferment,  and 
excites  the  conversion  of  the  sugar  of  milk  into  lactic  acid.  The  lactic  acid  in  its  turn 
coagulates  the  caseum,  which  in  the  consolidation  of  its  particles  attracts  the  butter. 
The  caseum  then  ceases  to  act  upon  the  sugar  of  milk,  and  consequently  produces  no 
more  lactic  acid. 

But  now,  if  the  lactic  acid  already  formed  be  saturated,  the  caseum  will  redissolve, 
and  the  phenomena  will  recommence  in  the  same  order.  This  is  easily  done  by  adding 
a  due  dose  of  bicarbonate  of  soda  to  the  soured  milk.  In  the  course  of  30  hours  a 
fresh  portion  of  lactic  acid  will  be  generated,  and  will  have  coagulated  the  milk  again. 
We  may  also  add  some  sugar  of  milk  to  the  liquid,  and  to  a  certain  extent  convert  it 
into  lactic  acid.  Milk  boiled,  and  kept  from  contact  of  air,  will  not  coagulate,  and 
remains  fresh  for  many  months.  Animal  membranes,  modified  by  exposure  to  moist  air 
for  some  time,  form  a  true  ferment  for  the  lactic  fermentation,  and  acidify  solutions  of 
sugar,  dextrine,  and  gum,  but  the  membranes  must  not  be  putrescent.  Cane-sugar, 
starch-sugar,  and  sugar  of  milk,  by  assuming  or  losing  a  little  w.iter,  acquire  the  con- 
stitution of  lactic  acid. 

Viscous  or  Mucous  Fermentation. — Every  one  is  acquainted  with  this  spontaneous 
modification  of  white  wine  and  ale,  which  gives  them  a  stringy  or  oily  aspect,  and  is 
called  in  French  graisse,  or  fat  of  wines,  and  in  English  the  ropiness  of  beer.  The 
viscous  fermentation  may  be  excited  by  boiling  yeast  with  water,  and  dissolving  sugar 
in  the  decoction,  after  it  has  been  filtered.  The  syrup  should  have  a  specific  gravity 
from  1*040  to  1'055,  and  be  kept  in  a  warm  place.  It  soon  assumes  the  consistence 
and  aspect  of  a  thick  mucilage,  like  linseed  tea,  with  the  disengagement  of  a  little  car- 
bonic acid  and  hydrogen,  in  the  proportion  of  2  or  3  of  the  former  gas  to  1  of  the 
latter.  A  ferment  of  globular  texture  like  that  of  yeast  is  formed,  which  is  capable 
of  producing  viscous  fermentation  in  any  saccharine  solution  to  which  it  is  added,  pro- 
vided the  temperature  be  suitable.  The  viscid  matter  being  evaporated  to  dryness 
forms  transparent  plates,  of  a  sub-nauseous  taste,  and  soluble  in  water,  but  less  easily 
than  gum  arabic.  Its  mucilage  is,  however,  thicker  than  that  of  gum,  and  yields  with 
nitric  acid,  oxalic  acid,  but  no  mucic  acid.  Four  parts  of  sugar,  treated  as  above 
described,  furnish  2*84  of  unchanged  sugar,  and  1*27  of  the  mucilage;  from  which  it 
appears  that  water  becomes  fixed  in  the  transformation.  Muriatic,  sulphuric,  sulphur- 
ous acids,  and  alum,  prevent  the  production  of  the  viscous  fermentation,  by  precipitating 
its  ferment.  It  is  probably  the  soluble  portion  of  gluten  which  is  the  cause  of  this  spe- 
cies of  fermentation.  It  has  been  found,  accordingly,  that  tannin,  which  precipitates  the 
said  glutinous  ferment,  completely  stops  the  viscous  fermentation,  or  graisse,  of  wines. 
It  is  owing  to  the  tannin  which  the  red  wines  derive  from  the  grape-stalks,  with  which 
they  are  long  in  contact  during  fermentation,  that  they  are  preserved  from  this  malady 
of  the  white"* wines.    The  gluten  of  must  is  of  two  kinds  the  one  soluble  in  virtue  of 


702 


FERMENTATION. 


FERMENTATION. 


703 


^ 


the  alcohol  and  tartaric  acid,  and  producing  the  viscous,  the  other  insoluble,  and 
producing  the  alcoholic  fermentation.  The  art  of  the  wine  maker  consists  in  precipi- 
tating the  injurious  ferment,  without  impeding  the  action  of  the  beneficial  one:  an  art 
of  considerable  delicacy  with  regard  to  sparkling  wines. 

Add  Fermentation  h^s  been  fully  discussed  under  acetic  acid.  It  requires  the  pre^ 
cnce  of  ready  formed  alcohol  and  air.  The  lactic  fermentation,  on  the  contrary,  may 
take  place  with  starchy  or  saccharine  substances,  without  the  intervention  of  alcohol  or 
constant  exposure  to  the  atmosphere ;  and  when  once  begun,  it  can  go  on  without  air. 
Acetification  has  a  striking  analogy  with  nitrification,  as  is  shown  by  the  necessity  of  a 
sil?face°trth     '"^'  ^  ^"""""^  ^"^^^^  ^""^  exposing  the  liquid  on  a  great 

Benzoic  Fermentatim  is  that  which  transforms  the  azotised  neutral  crystalline  matter 
existing  in  bitter  almonds,  which  has  no  action  upon  the  animal  economy,  into  new  and 
remarkable  products,  among  others  the  hydrure  of  benzoile  and  hydrocyanic  (prussic) 
acid,  which  together  constitute  the  liquid,  called  oil,  or  essence,  of  bitter  almonds,  a 
compound  possessed  of  volatility  and  poisonous  qualities.  The  attentive  study  of  this 
Hn'.Tn  hvl  '  ''7^^!?  ^  great  fact  in  vegetable  physiology,  the  spontaneous  pro- 
duct  on  by  means  of  certain  artifices,  of  certain  volatile  oils,  not  pre-existing  in  the 
plants,  yet  capable  of  being  generated  in  the  products  of  their  decomposition.  The 
volatile  Oil  of  bitter  almonds  constitutes  in  this  respect  a  starting  point,  from  which 
drJnrr'^rl'^"  °'^  of  mustard,  the  oil  of  spir^a,  and  which  wiU  hkely'lead  toX5 
discoveries  of  the  same  kmd.     See  Almond  and  Amygdaline 

Sinapic  Fermentation  is  that  by  which  the  oil  of  mustard  is'formed,  and  which  takes 
place  by  the  contact  of  water,  under  certain  conditions,  of  too  refined  and  scientific  a 
nature  for  this  practical  work. 

PecticFermeniati(m.—Veciic  acid  may  be  obtained  from  the  expressed  luice  of  cai 
rots,  and  it  seems  to  be  formed  in  the  process  of  extraction  by  the  reaction  of  albumine 

!?-n?"?\"P^''^^,"^'*^"'=^  called  pectine ;  a  transformation  analogous  therefore 
with  that  which  takes  place  in  the  formation  of  the  essence  of  bitter  almonds. 

Gallic  Fermentation.— GaUic  acid  does  not  exist  ready  formed  in  nut-galls,  but  la 
generated  from  their  tannin  when  ihey  are  ground,  made  pasty  with  water,  and  exposed 
to  the  air.  This  conversion  may  be  counteracted  by  the  red  oxide  of  mercury,  alcohol, 
suJphuric,  muriatic,  and  nitric  acids,  bromine,  essence  of  turpentine,  creosote,  oxalic 
acetic,  and  prussic  acids.  The  tannin  disappears  in  the  sequel  of  the  above  metamor' 
pnosis. 

Fatty  Fermentation.— All  fats  are  transformed  by  the  action  of  an  alkaline  or  other 
base  into  certain  acids,  the  stearic,  margaric,  the  oleic,  ethalic,  &c.  When  these  acids 
are  once  foiled,  they  can  not  by  any  means,  hitherto  known,  be  reconverted  into  the  prim- 
itive tat.  By  the  fixation  of  water  in  the  acid  and  the  base  (called  glycerine),  a  chan-e 
is  effected  which  can  not  be  undone,  because  the  glyceric  base  is  incapable  by  itself  to 
displace  the  water,  once  combined  in  the  hydrated  fat  acid.  The  circumstances  neces- 
sary to  the  fluty  fermentation,  are  like  those  of  other  fermentations;  namely  the  co- 
operation  of  an  albuminoid  matter,  along  with  water,  and  a  temperature  of  from  60°  to  S&* 
J? . ;  under  these  conditions,  the  matter  becomes  warm,  and  assumes  speedily  the  charac 
ter  of  rancidity;  acid  is  generated,  and  the  carbonate  of  soda  can  then  form  salts,  while 
the  fatty  acid  is  hberated;  a  circumstance  impossible  when  the  fat  was  vz-ted  upon  in 
the  neutral  state.     This  altered  fat,  treated  with  water,  gives  up  to  ii  g/vaWc  alcohol. 

Digestive  iemen/aiton.— Digestion  of  food  maybe  considered  in  its  essential  features 
as  a  peculiar  fermentative  process.     The  gastric  juice  is  a  genuine  ferment.     Tiedmann 
^melin   and  Prout,  have  shown  that  the  gastric  juice  contains  muriatic  acid ;  and 
li-berli  has  made  interesting  experiments  on  the  digestion  of  food  out  of  the  body   with 
water  containing  a  few  drops  of  the  same  acid.     He  observed  that  when  this  liquid  con 
tamed  none  of;  the  mucous  secretion  of  the  stomach,  it  did  not  dissolve  the  aliments  put 
into  It;  but  with  a  little  of  that  mucus  it  acquired  that  property  in  an  eminent  degree 
li-ven  the  mucus  of  the  bladder  had  a  like  eflect.     Schwann  and  Vogel  have  produced 
this  digestive  principle  in  a  pure  state,  called  by  them  pepsine,  as  obtained  most  abun- 
dantly from  the  stomachs  of  swine.     The  glandular  part  of  that  viscus  being  separated 
from  the  serous,  is  cut  into  small  pieces,  and  washed  with  cold  distilled  water.     After 
digestion  for  24  hours,  that  water  is  poured  off,  and  fresh  water  is  poured  on.     This 
operation  IS  repeated  for  several  days,  till  a  putrid  odor  begins  to  be  felt.     The  watery 
infusion  thMs  obtained  is  precipitated  by  acetate  of  lead,     this  white  flaky  precipitate 
contains  the  ptpsine,  accompanied  with  much  albumen.     It  is  then  washed,  mixed  with 
wate, ,  and  subjected  to  a  stream  of  sulphuretted  hydrogen.     The  whole  being  now 
thrown  on  a  filter,  the  coagulated  albumen  remains  on  the  paper,  along  with  the  sul. 


phuret  of  lead,  while  the  pepsine  liquor  passes,  associated  with  some  acetic  acid.  If  to 
this  liquor  a  very  small  quantity  of  muriatic  acid  be  added,  it  becomes  capable  of  carry- 
ing on  artificial  digestion.  Dry  pepsine  may  be  obtained  by  evaporating  the  above 
filtered  liquor  on  a  water  bath,  to  a  syrupy  consistence,  then  adding  to  it  absolute 
alcohol,  which  causes  a  bulky  whitish  precipitate.  This  dried  in  the  air  constitutes 
pepsine.  It  contains  a  minute  quantity  of  acetic  acid,  which  may  be  removed  com- 
pletely, by  heating  it  some  hours  on  the  water  bath.  The  white  powder  then  obtained 
is  soluble  in  water,  and  betrays  the  presence  of  no  acid  whatever.  According  to  Vogel, 
this  substance  is  composed  of,  carbon,  57' 72  ;  hydrogen,  5*67  ;  azote,  21-09;  oxygen, 
&c.,  15.52  =  100.  Vogel  has  proved  the  analogy  between  the  action  of  pepsine  and 
diastase  by  the  following  experiment : — 

He  dissolved  two  grains  of  pepsine  in  very  weak  muriatic  acid,  and  put  into  this 
liquor  heated  to  81°  F.,  small  bits  of  boiled  beef.  In  the  course  of  a  few  hours  the 
pieces  became  transparent  on  their  edges,  and  not  long  after  they  were  completely  dis- 
solved. He  now  added  fresh  morsels  in  succession,  till  those  last  put  in  remained  un- 
changed. He  found  by  analysis,  that  1*98  grains  of  the  pepsine  were  left,  showing  how 
minute  a  portion  of  this  ferment  was  necessary  to  establish  and  effect  digestion.  In 
fact,  we  may  infer  that  pepsine,  like  yeast,  serves  to  accomplish  digestion  without  any 
waste  of  its  own  substance  whatever,  or  probably  with  its  multiplication. 

Rennet,  with  which  milk  is  coagulated  in  making  cheese,  is  somewhat  of  the  same 
nature  as  pepsine.  It  has  been  called  chymosine.  But  the  simplest  digesting  liquor  is 
the  following : — 

If  10,000  parts  of  water  by  weight  be  mixed  with  6  parts  of  ordinary  muriatic  acid 
and  a  little  rennet,  a  liquor  is  obtained  capable  of  dissolving  hard  boiled  white  of  egg, 
beef,  gluten,  &c.,  into  a  transparent  jelly  in  a  feW  hours. 

Ammoniacal  Fermentation. — Under  this  title  may  be  described  the  conversion  of  urea 
into  carbonate  of  ammonia  under  the  influence  of  water,  a  ferment,  and  a  favorable 
temperature.     Urea  is  composed  in  atoms ;  reckoned 

In  volumes,  Carbon  4 ;  hydrogen  8 ;  azote  4 ;  oxygen  2 ; 

which  by  fixing  —  4 ;      —  2 ; 


give 


4; 


12; 


4; 


4: 


which  is  4  vol.  of  carbonic  acid,  and  8  of  ammonia;  equivalent  to  ordinary  carbonate 
of  ammonia.  The  fermentation  of  urea  plays  an  important  part  in  the  reciprocal  offices 
of  vegetable  and  animal  existence.  By  its  conversion  into  carbonate  of  ammonia,  urea 
beconies  a  food  fit  for  plants ;  and  by  the  intervention  of  the  mucous  ferment  which  urine 
contain^,  that  conversion  is  effected.  Thus  the  urea  constitutes  a  neutral  and  innocu- 
ous substance  while  it  remains  in  the  bladder,  but  is  changed  into  a  volatile,  alkaline, 
and  acrid  substance,  when  it  is  acted  upon  by  the  air.  Yeast  added  to  pure  urea  mixed 
with  water,  exercises  no  action  on  it  in  the  course  of  several  days ;  but  when  added  to 
urine,  it  soon  causes  decomposition,  with  the  formation  of  carbonate  of  ammonia,  and 
disengagement  of  carbonic  acid.  The  deposite  on  chamberpots  ill-cleaned  acts  as  a  very 
powerful  ferment  on  urine,  causing  the  complete  decomposition  of  fresh  urine  in  one 
fifth  of  the  time  that  would  otherwise  be  requisite. 

Nitrous  Fermentation,  as  exhibited  in  the  formation  of  nitric  acid  from  the  atmosphere, 
and  consequent  production  of  nitrates  in  certain  soils,  has  been  with  much  probability 
traced  to  the  action  of  ammonia  on  oxygen,  as  the  interiredium  or  ferment. 

Caseous  and  putrid  Fermentations. — Curd  is  convertea  into  cheese,  when  after  being 
coagulated  by  rev.net,  it  is  left  to  itself  under  certain  conditions;  and  this  constitutes  the 
true  distinctive  character  of  caseum.    In  the  production  of  cheese  there  is  evidently  the 
intervention  of  a  peculiar  ferment  which  is  gradually  formed,  and  the  decomposition  ol 
the  curd  into  new  products. 

For  animal  and  vegetable  matters  to  run  into  putrefaction,  they  must  be  in  contact 
with  air  and  water,  at  a  certain  temperature ;  viz.,  between  the  freezing  and  boiling 
points  of  water.  The  contact  of  a  putrid  substance  acts  as  a  ferment  to  fresh  animal 
and  vegetable  matters.  The  reagents  which  counteract  fermentation  in  general  stop 
also  putrefaction.  In  this  process,  myriads  of  microscopic  animalcules  make  their  ap- 
pearance, and  contribute  to  the  destruction  of  the  substances. 

A  dispute  haying  taken  place  between  some  distillers  in  Ireland  and  officers  of 
Excise,  concerning  the  formation  of  alcohol  in  the  vats  or  tuns  by  spontaneous  fermen. 
tation,  without  the  presence  of  yeast,  the  Commissioners  of  Excise  thought  fit  to  cause 
a  series  of  experiments  to  be  made  upon  the  subject,  and  they  were  placed  under  my 
general  superintendence.  An  experiment  was  made  on  the  6th  of  October,  with  the 
following  mixture  of  corn : — 

45 


704 


FERMENTATION. 


FERMENTATION. 


Mi 


t 


2  Bushels  of  Barley,  weighing 
I  Bushel  of  Malt, 
j^  Bushel  of  Oats 


-  lOOlbs.  5  07. 
-21         7 

-  20       12 


Total,  3  Bushels,  weighing    - 


142 


8 


The  bruised  corn  was  wetted  with  26  gallons  of  water  at  the  temperature  of  160°  F., 
and,  after  proper  stirring,  had  8  gallons  more  of  water  added  to  it  at  the  average  tem- 
perature of  194^.  The  mash  was  again  well  stirred,  and  at  the  end  of  45  minutes 
the  whole  was  covered  up,  having  at  that  time  a  temperature  of  138°  F.  Three  hours 
afterward,  16  gallons  of  wash  only  were  drawn  off;  being  considerably  less  than 
should  have  been  obtained,  had  the  apparatus  been  constructed  somewhat  differently, 
as  shall  be  presently  pointed  out.  The  gravity  of  that  wash  was  1*060,  or,  in  the  lan- 
guage of  the  distiller,  60^.  After  a  delay  of  two  hours  more,  twenty  additicnal 
gallons  of  water  at  the  temperature  of  200°  were  introduced,  when  the  mash  was  well 
stirred,  and  then  covered  up  for  two  hours,  at  which  period  23  gallons  of  fine  worts 
of  specific  gravity  1-042  were  drawn  off.  An  hour  afterward  12  gallons  of  water  at 
200°  were  added  to  the  residual  grains,  and  in  an  hour  and  a  half  11  gallons  of  wort 
of  the  density  1*033  were  obtained.  N^xt  morning  the  several  worts  were  collected 
in  a  new  mash  tun.  They  consisted  of  48  gallons  at  the  temperature  80°,  and  of  a 
specific  gravity  2-0465  when  reduced  to  60°.  Being  set  at  80°,  fermentation  soon 
commenced;  in  two  days  the  specific  gravity  had  fallen  to  1*0317,  in  three  days  to 
1*018,  in  four  days  to  1-013,  and  in  five  days  to  1.012,  the  temperature  having  at  last 
fallen  to  78*  F.  The  total  attenuation  was  therefore  34|°,  indicating  the  production 
of  3-31  gallons  of  proof  spirit,  while  the  produce  by  distillation  in  low  wines  was  3-22; 
and  by  rectification  in  spirits  and  feints  it  was  3-05.  The  next  experiment  was  com- 
menced on  the  12th  of  October,  upon  a  similar  mixture  of  corn  to  the  preceding. 
48  gallons  of  worts  of  1-043  specific  gravity  were  set  at  82°  in  the  tun,  which  next 
day  was  attenuated  to  1-0418,  in  two  days  to  1-0202,  in  three  days  to  1-0125,  and  in 
five  days  to  1*0105,  constituting  in  the  whole  an  attenuation  of  32|°,  which  indicates 
the  production  of  3*12  gallons  of  proof  spirits ;  while  the  produce  of  the  first  distiUk 
tion  was  2-93  in  low  wines,  and  that  of  the  second  in  feints  and  spirits  was  2*66.  Ii 
these  experiments  the  wash,  when  fermenting  most  actively,  seemed  to  simmer  and  boil 
on  the  surface,  with  the  emission  of  a  hissing  noise,  and  the  copious  evolution  of  car- 
bonic acid  gas.  They  prove  beyond  all  doubt  that  much  alcohol  may  be  generated  in 
grain  worts  without  the  addition  of  yeast,  and  that,  also,  at  an  early  period;  but  the 
fermentation  is  never  so  active  as  with  yeast,  nor  does  it  continue  so  long,  or  proceed 
to  nearly  the  same  degree  of  attenuation.  I  was  never  satisfied  with  the  construction 
of  the  mash  tun  used  in  these  experiments,  and  had  accordingly  suggested  another 
form,  by  which  the  mash  mixture  could  be  maintained  at  the  proper  temperature 
during  the  mashing  period.  It  is  known  to  chemists  that  the  diastase  of  malt  is  the 
true  saccharifying  ferment  which  converts  the  fecula,  or  starch  of  barley  and  other 
corn,  into  sugar ;  but  it  acts  beneficially  only  between  the  temperatures  of  145°  and 
168°  F.  When  the  temperature  falls  below  the  former  number,  saccharification  lan- 
guishes ;  and  when  it  rises  much  above  the  latter,  it  is  entirely  checked.  The  new 
mash  tun  was  made  of  sheet  zinc,  somewhat  wider  at  bottom  than  top;  it  was 
placed  in  a  wooden  tun,  so  much  larger  as  to  leave  an  interstitial  space  between  the 
two  of  a  couple  of  inches  at  the  sides  and  bottom.  Through  this  space  a  current 
of  water  at  160°  was  made  to  circulate  slowly  during  the  mashing  period.  Three 
bushels  of  malt,  weighing  125  lbs.  3  oz.,  were  wetted  with  30  gallons  of  water  at  167°, 
and  the  mixture  being  well  agitated,  the  mash  was  left  covered  up  at  a  temperature 
of  140°  during  three  hours,  when  19  gallons  of  fine  worts  were  drawn  off  at  the  spe- 
cific gravity  of  1-0902  or  90-2°.  Twenty  gallons  more  water  at  167°  were  then  added 
to  the  residuum,  which  afforded  after  two  hours  28  gallons  of  wort  at  the  gravity 
1*036;  12  gallons  of  water  at  167°  were  now  poured  on,  which  yielded  after  other 
two  hours  15  gallons  at  the  gravity  1-0185.  Forty  gallons  of  fine  worts  at  1-058 
gravity  and  68"^  temperature  were  collected  in  the  evening  of  the  same  day,  and  let 
into  the  tun  with  5  per  cent,  of  yeast.  The  attenuation  amounted  in  six  days  to  54°. 
The  third  wort  of  this  brewing,  amounting  to  15  gallons,  being  very  feeble,  was  mixed 
with  7  gallons  of  the  first  and  second  worts,  put  into  a  copper,  arid  concentrated  by 
boiling  to  11  gallons,  which  had  a  gravity  1*058  at  60°  F.  They  were  separately 
fermented  with  5  per  cent,  of  yeast,  and  suffered  an  attenuation  of  48|°.  The  produce 
of  spirit  from  both  indicated  by  the  attenuation  was  5*36  gallons ;  the  produce  in  low 
wines  was  actually  5-52,  and  that  in  spirits  and  feints  was  5-33,  being  a  perfect  accord- 
ance with  the  Excise  tables. 

The  next  experiments  were  made  with  a  view  of  determining  at  what  elevation  of 
temperature  the  activity  or  efficiency  of  yeast  would  be  paralysed,  and  how  far  the 


705 


attenuation  of  worts  could  be  pushed  witliin  six  hours,  which  is  the  time  limited  by 
law  for  worts  to  be  collected  into  the  tun,  from  the  time  of  beginning  to  run  from  the 
coolers.     When  worts  of  the  gravity  1*0898  were  set  at  96°  Fahr.,  with  5  per  cent  of 
•    yeast,  they  attenuated  26*9°,  m  6  hours ;  worts  of  1*0535  gravity  set  at  1 10°  with 
5  per  cent,  of  yeast,  attenuated  16^  in  about  5  hours;  but  when  worts  of  1-0533  were 
set,  as  above,  at  120°,  they  neither  fermented  then,  nor  when  allowed  to  cool ;  show- 
ing that  the  activity  of  the  yeast  was  destroyed.    When  fresh  yeast  was  now  added  to 
the  last  portion  of  worts,  the  attenuation  became  5*8  in  2  hours,  and  28*4°  in  3  days  * 
showing  that  the  saccharine  matter  of  the  worts  still  retained  its  fermentative  faculty' 
Malt  worts,  being  brewed  as  above  specified,  were  set  in  the  tun,  one  portion  at  a  tem- 
perature of  70°,  with  a  gravity  of  1*0939,  and  5  per  cent,  of  yeast,  which  attenuated 
66°  in  3  days ;  other  two  portions  of  the  same  gravity  were  set  at  120°  with  about  10 
per  cent,  of  yeast,  which  underwent  no  fermentative  change  or  attenuation  in  6  hours, 
all  the  yeast  having  fallen  to  the  bottom  of  the  tuns.    When  these  two  samples  of 
worts  were  allowed,  however,  to  cool  to  from  74°  to  72°,  fermentation  commenced, 
and  produced  m  two  days  an  attenuation  of  about  79°.     It  would  appear,  from  these 
last  two  experiments,  that  yeast  to  the  amount  of  5  per  cent,  is  so  powerfully  affected 
by  strong  worts  heated  to  120°  as  to  have  its  fermentative  energy  destroyed;  but  that 
when  yeast  is  added  to  the  amount  of  10  per  cent.,  the  5  parts  of  excess  are  not  per- 
manently decomposed,  but  have  their  activity  merely  suspended  till  the  saccharine 
liquid  falls  to  a  temperature  compatible  with  fermentation.    Yeast,  according  to  my 
observations,  when  viewed  in  a  good  acromatic  microscope,  consists  altogether  of  trans- 
lucent spherical  and  spheroidal  particles,  each  of  about  the  6000th  part  of  an  inch  in 
diameter.     When  the  beer  in  which  they  float  is  washed  away  with  a  little  water  they 
are  seen  to  be  colorless;  their  yellowish  tint,  when  they  are  examined  directh' from 
the  fermenting  square  or  round  of  a  porter  brewery,  being  due  to  the  infusion  of  the 
brown  malt.    The  yeast  of  a  square  newly  set  seems  to  consist  of  particles  smaller 
than  those  of  older  yeast,  but  the  difference  of  size  is  not  considerable.    The  re- 
searches of  Schulze,  Cagniard  de  la  Tour,  and  Schwann,  appear  to  show,  that  the 
vinous  fermentation,  and  the  putrefaction  of  animal  matters,  processes  which  have  been 
hitherto  considered  as   belonging   entirely  to  the   domain  ol   chemical  affinity—are 
essentially  the  results  of  an   organic  development  of  living  beings.    This  position 
seems  to  be  established  by  the  following  experiments:    1.  A   matrLs   or  flask   con- 
taining a  few  bits  of  flesh,  being  filled  up  to  one  third  of  its  capacity  with  water,  wa« 
closed  with  a  cork,  into  which  two  slender  glass  tubes  were  cemented  air-ti?ht.     Both 
of  these  tubes  were  passed  externally  through  a  metallic  bath,  kept  constantly  melted, 
at  a  temperature  approachmg  to  that  of  boiling  mercury.      The  end  of  one  of  the 
Tu!V.  7^rS»«^^?  ^'om  the  bath,  was  placed  in  communication  with  a  jjasometer. 
in  it  Td  t"hP  ^[  ^^^"^t'^^s^  ^^•■e  now  made  to  boil  briskly,  so  that  the  air^contained 
n?,rrnn.    r   t    "    f  ^•"^^'  '''"'  ^^1^"^^*     The  matrass  being  then  allowed  to  cool,  a 
tpr^h;?t  "'''''  l^n-^l'"'^  "^^^  T'^^  constantly  to  pass  through  it  from  the  gasome- 
ter  ^lhlle  the  metallic  bath  was  kept  constantly  hot  enough  to  decompose  the  livino 
particles  m  the  air.     In  these  experiments,  which  were  many  times  repeated,  no  infu^ 
soria  or  fungi  appeared,  no  putrefaction  took  place,  the  flesh  underwent  no  chan-e 
and  the  liquor  remained  as  clear  as  it  was  immediately  after  beine  boiled.     As  it  wa^* 
found  very  troublesome  to  maintain  the  metallic  bath  at  the  meltfng  pitch,  the  foHow- 
mg  mod.ficaiion  of  the  apparatus  was  adopted  in  the  subsequent  researches  :     A  flalk 
of  three  ounces  capacity,  being  one  fourth  filled  with  water  and  flesh,  was  closed  with 
cnri'    .1''°    '  ^^cT'^  '"  Its  place  by  wire.     Two  glass  tubes  were  pass.^d  through  the 
cork;  the  one  of  them  was  bent  down,  and  dipped  at  its  end  into  a  small  capsule  con- 
taining quicksilver,  covered  with  a  layer  of  oil ;  the  other  was  bent  on  leaving,  the 
cork,  lirst  into  a  horizontal  direction,  and  downward  for  an  inch  and  a  half  afterward 
no  nf^  P^i:  *>f  «P"-^I  J"r"s>  then  upward,  lastly  horizontal,  whence  it  was  drawn  out  to. 
K;  fl     ^^  pores  of  the  cork  having  been  filled  with  caoutchouc  varnish,  the  contents 
thin    .^f  V"""^  boiled  till  steam  issued  copiously  through  both  of  the  glass  tubes,  and 

fir^n  M  r  ^"^  °'  ^."'^T  ^'  ^^'  ^'  ^^"^'^^  ^^^*^^-  ^'^  «rder  that  no  living  par- 
ticles could  be  generated  in  the  water  condensed  beneath  the  oil,  a  few  fragments  of 
eorrosive  sublimate  were  laid  upon  the  quicksilver.  During  the  boiling,  the  flame  of 
a  spirit  lamp  was  drawn  up  over  the  spiral  part  of  the  second  glass  tube^by  means  of 
a  glass  chimney  placed  over  it,  so  as  to  soften  the  slass,  while  the  further  part  of  the 
tube  was  heated  by  another  spirit  lamp,  to  prevent  its  getting  cracked  by  the  condens- 
ation  of  the  steam.     After  the  ebullition  had  been  kept  up  a  quarter  of  an  hour,  the 

♦  K  "^WK  Tk  ^"^  ''°*'''  ^""^  '^^  ^"^^  ^'^h  air  through  the  hot  spiral  of  the  second 
lube.  When  the  contents  were  quite  cold,  the  end  of  this  tube  was  hermetically 
sealed,  the  part  of  it  between  the  point  and  the  spiral  was  heated  strongly  with  the 
names,  and  the  lamps  were  then  withdrawn.    The  matrass  contained  now  nothing  but 


706 


FERRIC  ACID. 


m 


boiled  flesh  and  gently  ignited  air.    The  air  was  renewed  occasionallj  through  the 
second  tube,  its  spiral  part  being  first  strongly  lieated,  its  point  then  broken  oflF,  and 
connected  with  a  gasometer,  which  caused  the  air  to  pass  onward  slowly,  and  escape 
at  the  end  of  the  first  tube  immersed  in  the  quicksilver.    The  end  of  the  second  tube 
was  a?ain  hermetically  closed,  while  the  part  interjacent  between  it  and  the  spiral  was 
exposeil  to  the  spirit  flame.     By  means  of  these  precautions,  decoctions  of  flesh  were 
preserved,  during  a  period  of  six  weeks,  in  a  temperature  of  from  14^  to  20^  R.  (oSg 
to  77^  F.),  without  any  appearance  of  putrefaction,  infusoria,  or  mouldiness  :  on  open- 
ing the  vessel,  however,  the  contents  fermented  in  a  few  days,  as  if  the,    had  beea 
boiled  in  the  ordinary  manner.     In  conducting  such  researches,   the  greatest  pams 
must  be  taken  to  render  the  cork  and  junctions  of  the  glass  tubes  perfectly  air-tight. 
The  following  more  convenient  modification  of  the  experiment,  but  one  equally  suc- 
cessful and  demonstrative,  was  arranged  by  F.  Schulze.     The  glass  tubes  connected 
with  the  flask  were  furnished  each  with  a  bulb  at  a  little  distance  from  the  cork ;  into 
one  of  which  globes  caustic  alkaline  ley  being  put,  and  into  the  other  strong  sul- 
phuric acid,  air  was  slowly  sucked  through  the  exiremity  of  the  one  lube,  while  it 
entered  at  the  other,  so  as  to  renew  the  atmosphere  over  the  decoction  of  flesh  in  the 
flask.     In  another  set  of  experiments,  four  flasks  being  filh  I  with  a  solution  of  cane- 
sugar  containing  some  beer-yeast,  were  corked  and  plunged  m  boiling  water  till  they 
acquired  its  temperature.     They  were  then  taken  out,  inverted  in  a  mercurial  bath, 
uncorked,  and  allowed  to  cool  in  that  position.     From  one  third  to  one  fourth  of  then 
volume  of  atmospherical  air  was  now  introduced  into  each  of  the  flasks;    into  two  of 
them  through  slender  glass  tubes  kept  red  hot  at  a  certain  point,  into  the  other  two 
through  glass  tubes  not  heated.     Bv  analysis  it  was  found  that  the  air  thus  heated 
contafned  only  19-4  per  cent,  of  oxygen,  instead  of  20-8;   but,  to  compensate  ior  this 
deficiency,  a  little  more  air  was  admitted  into  the  two  flasks  connected  with  the  heatea 
tubes  than  into  the  two  others.     The  flasks  were  now  corked  and  placed   in  an  in- 
verted position,  in  a  temperature  of  from  10^  to  14-   R.  (541^^  to  63|-"  F.).      After  a 
period  of  from  four  to  six  weeks,  it  was  found  that  fermentation  had  taken  place  m 
both  of  the  flasks  which  contained  the  non-ignited  air—for,  in  loosening  the  corks, 
Bome  of  the  contents  were  proiected  with  force — but,  in  the  other  two  flasks,  there 
was  no  appear*nce  of  fermentation,  either  then,  or  in  double  the  time.     As  the  extract 
of  nux  vomica  is  known  to  be  a  poison  to  infusoria  (animalcules),  but  not  to  vegetating 
mould,  while  arsenic  is  a  poison  to  both,  by  these  tests  it  was  proved  that  the  living 
particles  instrumental  to  fermentation  belonged  to  the  order  of  plants  of  the  confer- 
void  family.     Beer  veast,  according  to  Schwann,  consists  entirely  of  microscopic  fungi, 
in  the  shape  of  small  oval  grains  of  a  yellowish  white  color,  arranged  in  rows  oblique 
to  each  other.     Fresh  grapes  must  contain  none  of  them ;  but  after  being  exposed  to 
the  air  at  20"  R.,  for  36  hours,  similar  grains  become  visible  in  the  microscope,  and 
may  be  observed  to  grow  larger  in  the  course  of  an  hour,  or  even  in  half  that  time. 
A  few  hours  after  these  plants  are  first  perceived,  gas  begins  to  be  disengaged.    They 
multiply  greatly  in  the  course  of  fermentation,  and  at  its  conclusion  subside  to  the  bottom 
of  the  beer  in  the  shape  of  a  yellow  white  powder. 

FERRIC  ACID.  This  new  compound  having  been  prescribes  as  a  source  of  sup- 
plying oxygen  to  persons  confined  in  diving-bells  and  in  mines,  by  M.  Payerne,  in  a 
patent  recently  granted  to  him,  merits  notice  in  a  practical  work.  M.  Fremy  is 
the  discoverer  of  this  new  acid,  which  he  obtains  in  the  state  of  ferrate  of  pot- 
ash, by  projecting  10  parts  of  dry  nitre  in  powder  upon  5  parts  of  iron  filings, 
ignited  in  a  crucible ;  when  a  reddish  mass,  containing  much  ferrate  of  potash,  is 
formed.  The  preparation  succeeds  best  when  a  large  crucible,  capable  of  holding 
about  a  pint  of  water,  is  heated  so  strongly  that  the  bottom  and  a  couple  of  inches 
above  it,  appear  faintly,  but  distinctly  red,  in  which  state  the  heat  is  just  adequate  to 
eflfect  due  deflagration  without  decomposition.  An  intimate  mixture  of  about  200  grains 
of  dried  nitre  with  about  one  half  its  weight  of  the  finest  iron  filings,  is  to  be  thrown  at 
once  upon  the  side  of  the  crucible.  The  mixture  will  soon  swell  and  deflagrate.  The 
crucible  being  taken  from  the  fire,  and  the  ignited  mass  being  cooled,  is  to  be  taken 
out  with  an  iron  spoon,  pounded,  immediately  put  into  a  bottle,  and  secluded  from  the 
tir,  in  which  it  would  speedily  attract  moisture,  and  be  decomposed.  It  is  resolved 
by '  the  action  of  water,  especially  with  heat,  into  oxygen  gas,  peroxide,  and  nitrate 

Mr.  J.  D.  Smith  prepares  the  ferrate  of  potash  by  exposing  to  a  full  red  heat  a  mix- 
lure  of  finely  powdered  peroxide  of  iron  with  four  times  its  weight  of  dry  nitre.  It 
has  an  amethyst  hue,  but  so  deep  as  to  appear  black,  except  at  the  edges.  Oxygen  is 
rapidly  evolved  by  the  action  of  the  sulphuric  or  nitric  acid  upon  its  solution.  He  con- 
siders the  atom  of  iron  to  exist  in  this  compound,  associated  with  3  atoms  of  oxygen,  or 
double  the  proportion  of  that  in  the  red  oxide.    Hence  52  grains  of  pure  ferric  acid 


4 

I 

I 


FIBRE,  VEGETABLE.  707 

should  give  off  12  grains  of  oxygen,  equal  to  about  36  cubic  inches;  but  how  much  of 
the  ferrate  of  potash  may  be  requisite  to  produce  a  like  quantity  of  oxygen  cannot  be 
stated,  from  the  uncertainty  of  the  operation  by  which  it  is  produced 

FERRIC-CYANIDE  OF  POtIsSIUM,  ^or  Red  Pruliate^  Potash.  This 
beautiful  and  useful  salt,  discovered  by  L.  Gmelin,  is  prepared  by  pissing  chlorine  gal 
through  a  weak  solution  of  the  prussiate  of  potash  (ferro-cyanide  of  potassium)  lilf  k 
ceases  to  aff-ect  solution  of  red  sulphate  of  iron,  taking  care  to  agitate  the  liquid  all  the 

fTp  fl^r.  TJ""  HI  ^°  ^"""'^  ""^  '^^2"°^-  ^^  ^««^^"S  ^^'•^^^h  the  weak  solution  to 
the  flame  of  a  candle,  one  may  see  the  period  of  change  from  the  greenL.h  to  the  red 
hue,  which  indicates  the  completion  of  the  process.  The  liquor  being  filtered  and 
evaporated  in  a  dish  with  upright  sides,  will  eventually  aff^ord  c^rstalline  needles  ^^ 
sessed  of  an  almost  metallic  lustre,  and  a  yellow  color,  inclining  to  red.  These  be^t 
dissolved  and  recrystallized,  wil  become  extremely  beautiful.  This  salt  is  composed 
of  33-68  parts  of  potassium,  16-48  of  iron,  and  47-84  of  cyanogen.    It  is  therefore  a 

tilt  of  'h    n  t'^-i"^';  •  ^^  ^■^'''  "^  '°V^  ^."*"'  «"^  ^^  i*  forms^hen  the  Lst  deSc^tc 
test  of  the  protoxide  of  iron,  is  very  useful  in  Clorometry.-^See  Appendix. 

yf2%lteZfrielllT!L'''''^  ^'^  ^^"^^"^  ^^-^^  P^-P^'tates  with  the  soluUon. 


Titanium 

Uranium 

Manganese 

Cobalt 

Nickel 

Copper  • 

Silver 

Mercury 

Tin 

Zinc 

Bismuth 

Lead 

Iron  protoxide  - 

peroxide  - 


Brownish  yellow. 

Reddish  brown. 

Brownish  gray. 

Deep  reddish  brown. 

Yellowish  brown. 

Dirty  yellowish  brown. 

Orange  yellow. 

Yellow,  with  both  the  protoxide  and 

peroxide  salts. 
White. 

Orange  Yellow. 
Yellowish  brown. 
No  precip. 
Blue. 
No  precip. 


The  ferric-oyanide  of  potassium  has  been  introduced  into  dyeing  and  calico-printin- 
In  e,ise  an  excess  of  chlorine  has  been  used  in  preparing  the  above  salt  Poiett 
recommends  to  add  to  its  solution,  when  near  the  ery^lline  point  a  ?ew  dropsof 
po  nsh  lye,  in  order  to  decompose  a  green  substance  thit  is  present  ihich  takes  place 
with  the  precipitation  of  a  little  peroxide  of  iron.  ^ 

FERROCYANATE  or,  more  correctly,  FERROCYANIDE.  (Ferrocyanure  Fr  • 
Etsencyanid  Germ.)  Several  compounds  of  cyanogen  and  metals  possess  Ihe  prineri; 
of  uni  mg  together  into  double  cyanides ;  of  which  there  are  none  so  remark ableTnthS 
respec,as  the  protocyanide  of^ iron.  This  appears  to  be  capable  of  combtn  L  with 
several  simple  cyanides,  such  as  that  of  potassium,  sodium,  barium,  s.^ntium"  cflcUim 
and  ammonium.  The  only  one  of  these  double  cyanides  of  any  importance  in  man' 
ufacfires  is  the  first,  which  is  described  under  its  commercial  name,  Prussiatk  «; 

FERROPRUSSIATES;  another  name  for  Ferrocyanides 

FIBRE,  VEGETABLE,  called    also  Lignine   (Ligneux    Fr  •     P/fan^^  r        /  /r 
Germ.)   is  the  most  abundant  and  general  ingredient^oTpS,  fxiVtingt  a^tfef  ^ 

o'qt'^  'q^  ^''''!'  ^\V.'^"^^/'?"  ^^.^^••«>  «"^  '^'  ^'••"'^ ;  amounting  in^Le  compact  w^ 
W  ll  hV"'?"^  /' ''  obtamedm  a  pure  state  by  treating  sawfdust  successively  whh 
hot  alcohol,  water,  dilute  muriatic  acid,  and  weak  potash  l?y,  which  dissofve  first  the 
inirr'  «^/°"^;/he  extractive  and  saline  matters ;  third,  the  carbonatran^^^^^^^ 
of  hme ;  and,  astly,  any  residuary  substances.  Ligneous  fibres,  such  as  saw-dus°  Cw- 
dered  barks,  s  raw  hemp,  flax,  linen,  and  cotton  cloth,  are  convertible  by  the  aciorrf 

Slnrthato're  7^,^''  '  '"""'  ^"'^^^"^^  ^'^'^^^^^^^  '^  ^'--'  ^^^  sugaT  re'^m- 

an5^nrinkll'n!^.^•f'qT  ""T"/^  ?T'-^^  ^"'^'^^'  «^  ^^y  ^^  cordage,  chopped  smaU, 
and  sprmkle  over  it  34  parts  of  sulphuric  acid,  by  degrees,  so  as  to  avoid  heating  the 
mixture,  while  we  constantly  stir  it;  and  if,  in  a  quarter  of  an  hour  we  trifulte  the 

ti^fur  ""^^  ^^^  r'^  ^^  produced,  almost  entirely  soluble  in  waier.  The  |um 
being  thus  formed,  may  be  separated  from  the  acid  by  dilution  with  water,  and  additi^ 
of  the  requisite  quantity  of  chalk;  then  straining  the  saturated  liquid  through  lineS 
cloth,  concentrating  it  by  evaporaUon,  throwing  down  any  remaining  hme  b^r  oxaUt 


708 


FIBRINE. 


FILE. 


709 


\¥l^ 


mcid,  filtering  anew,  and  mixing  the  mucilage  wiih  alcohol  in  great  excess,  which  will 
take  up  the  free  acid,  and  throw  down  the  gum.  From  24  parts  of  hemp  fibres  thiis 
treated,  fully  24  parts  of  a  gummy  mass  may  be  obtained,  containing,  however,  probabiy 

When  instead  of  saturating  the  diluted  acid  paste  with  chalk,  we  boil  it  for  10  hour*, 
the  gummy  matter  disappears,  and  is  replaced  by  sugar,  which  may  be  purified  without 
any  difficulty,  by  saluraiion  with  chalk,  filtration,  and  evaporation  to  the  consistence  of 
sirup  In  24  hours  crystallization  begins,  and,  in  2  or  3  days,  a  concrete  mass  of  grape 
sugar  is  formed;  which  needs  merely  to  be  pressed  strongly  between  old  linen  cloths 
doubled,  and  then  crystallized  a  second  time.  If  this  sirup  be  treated  with  bone  black, 
a  brilliant  white  sugar  will  be  procured.  20  parts  of  linen  rags  yield  23  of  good  sugar. 
Braconnot.  Guerin  got  87|  of  dry  sugar  from  100  parts  of  rags,  treated  with  250  of  sul- 
phuric acid.  See  Wood.  .  ..  •  •  i  , 
FIBRINE  (Eng.  and  Fr. ;  Thierischer  Fasersioff,  Germ.)  constitutes  the  principal  pari 
of  animal  muscle ;  it  exists  in  the  chyle,  the  blood,  and  may  be  regarded  as  the  most 
abundant  constituent  of  animal  bodies.  It  may  be  obtained  in  a  pure  state  by  agjtaling 
or  beating  new  drawn  blood  with  a  bundle  of  twigs,  when  it  will  attach  itself  to  them  in 
lon«'  reddish  filaments,  which  may  be  deprived  of  color  by  working  them  with  the  hands 
und'er  a  streamlet  of  cold  water,  and  afterwards  freed  from  any  adhering  grease  by  diges- 
tion in  alcohol  or  ether.  ,.,,,.••,•  j  a  „«,«, 
Fibrine,  thus  obtained,  is  solid,  white,  flexible,  slightly  elastic,  insipid,  inodorous,  denser 
than  water,  but  containing  four  fifths  of  its  weight  of  it,  and  without  action  on  litmus. 
When  dried,  it  becomes  semi-transparent,  yellowish,  stiff,  and  brittle :  water  restores  its 
softness  and  flexibility.  100  parts  of  fibrine  consist  of  53-36  carbon,  19-68  oxygen,  7-02 
hydrogen,  and  19-31  azote.  As  the  basis  of  flesh,  it  is  a  very  nutritious  substance,  and  is 
essential  to  the  sustenance  of  carnivorous  animals.                                  ,      .      *    *i. 

FILE  {Lime,  Fr. ;  Feile.  Germ.)  is  a  well  known  steel  instrument,  having  teeth  upom 
the  surface  for  cutting  and  abrading  metal,  ivory,  wood,  &c.  ,     j    ,  •    i       ,     a 

When  the  teeth  of  these  instruments  are  formed  by  a  straight  sharp-edged  chisel,  extend- 
ing across  the  surface,  they  are  properly  called  files ;  but  when  by  a  sharp-pmnled  tool,  in 
the  form  of  a  triangular  pyramid,  they  are  termed  rasps.  The  former  are  used  for  all  the 
metals,  as  well  as  ivory,  bone,  horn,  and  wood ;  the  latter  for  wood  and  horn. 

Files  are  divided  into  two  varieties,  from  the  form  of  their  teeth.  When  the  teeth  are 
a  series  of  sharp  edges,  raised  by  the  flat  chisel,  appearing  like  parallel  furrows,  either 
at  right  angles  to  the  length  of  the  file,  or  in  an  oblique  direction,  they  are  termed  single 
cut  But  when  these  teeth  are  crossed  by  a  second  series  of  similar  teeth,  they  are  said 
to  be  double  cut.  The  first  are  fitted  for  brass  and  cop|)er,  and  are  found  to  answer  bet- 
ter when  the  teeth  run  in  an  oblique  direction.  The  latter  are  suited  for  the  harder  met- 
als  such  as  cast  and  wrouslit  iron  and  steel.  Such  teeth  present  sharp  angles  to  the  sub- 
stance, which  penetrate  it,  while  single  cut  files  would  slip  over  the  surface  of  these  met- 
als.  The  double  cut  file  is  less  fit  for  filing  brass  and  copper,  because  its  teeth  would  be 
very  liable  to  become  clogged  with  the  filings. 

Files  are  also  called  by  different  names  according  to  their  various  degrees  of  fineness. 
Those  of  extreme  roughness  are  called  rough ;  the  next  to  this  is  the  bastard  cut;  the 
third  is  the  second  cut ;  the  fourth,  the  smooth  ;  and  the  finest  of  all,  the  dead  smooth. 
The  very  heavy  square  files  used  for  heavy  smith-work,  are  sometimes  a  little  coarser  than 
the  rough ;  they  are  known  by  the  name  of  rubbers.     „      ,   ,^         .  ^^  > 

FiWare  also  distinguished  from  their  shape,  as  flat,  half-round  three-square,  four- 
square,  and  round.  The  first  are  sometimes  of  uniform  breadth  and  thickness  throughout, 
and  sometimes  tapering.  The  cross  section  is  a  parallelogram.  The  half-round  is  gen- 
erally tapering,  one  side  being  flat,  and  the  other  rounded.  The  cross  section  is  a  seg- 
ment of  a  circle,  varying  a  little  for  different  purposes,  but  seldom  equal  to  a  semi-circ  e. 
The  three-square  generally  consists  of  three  equal  sides,  being  equUateral  prisms,  mostly 
tapering;  those  which  are  not  tapering  are  used  for  sharpening  the  teeth  ol  saws.  Ihc 
four-square  has  four  equal  sides,  the  section  being  a  square.  These  files  are  generaUy 
thickest  in  the  middle,  as  is  the  case  with  the  smith's  rubber.  In  the  round  file,  the  sec- 
tion is  a  circle,  and  the  file  generally  conical.  ,  r  vv  ♦  -^ 
The  heavier  and  coarser  kinds  of  files  are  made  from  the  inferior  marks  of  blistered 
steel  Those  made  from  the  Russian  iron,  known  by  the  name  of  old  sable,  called  from 
its  m'ark  CCND,  are  excellent.  The  steel  made  from  the  best  Swedish  iron,  called  hoop 
L  or  Dannemora,  makes  the  finest  Lancashire  files,  for  watch  and  clock  makers ;  a  man- 
ufacture for  which  the  house  of  Stubbs  in  Warrington  is  celebrated. 

The  steel  intended  for  files  is  more  highly  converted  than  for  other  purposes,  to  give 
them  proper  hardness.  It  should  however  be  recollected,  that  if  the  l^^rdness  be  no» 
accompanied  with  a  certain  degree  of  tenacity,  the  teeth  of  the  file  break,  and  do  but  litdc 

**  faSi  files  are  mostly  made  of  cast  steel,  which  would  be  the  best  for  all  others,  if 


ft  were  not  for  its  higher  price.  It  is  much  harder  than  the  blistered  steel,  and  fiom 
having  been  in  the  fluid  state,  is  entirely  free  from  those  seams  and  loose  parts  so  common 
to  blistered  steel,  which  is  no  sounder  than  as  it  comes  from  the  iron  forge  before  con- 
version. 

The  smith's  rubbers  are  generally  forged  in  the  common  smith's  forge,  from  the  con- 
verted bars,  which  are,  for  convenience,  made  square  in  the  iron  before  they  come  into 
this  country.  The  files  of  lesser  size  are  made  from  bars  or  rods,  drawn  down  from  the 
Mistered  bars,  and  the  cast  ingots,  and  known  by  the  name  of  tilted  steel. 

The  file-maker's  forge  consists  of  large  bellows,  with  coke  as  fuel.  The  anvil-block, 
particularly  at  Sheffield,  is  one  large  mass  of  mill  stone  girt.  The  anvil  is  of  consider- 
able size,  set  into  and  wedged  fast  into  the  stone;  and  has  a  projection  at  one  end,  with 
a  hole  to  contain  a  sharp-edged  tool  for  cutting  the  files  from  the  rods.  It  alsc 
contains  a  deep  groove  for  containing  dies  or  bosses,  for  giving  particular  forms  to  the 
files. 

The  flat  and  square  files  are  formed  entirely  by  the  hammer.  One  man  holds  the  hot 
bar,  and  strikes  with  a  small  hammer.  Another  stands  before  the  anvil  with  a  two-hand- 
ed hammer.  The  latter  is  generally  very  heavy,  with  a  broad  face  for  the  large  files. 
They  both  strike  with  such  truth  as  to  make  the  surface  smooth  and  flat,  without  what  is 
called  hand-hammering.  This  arises  from  their  great  experience  in  the  same  kind  of 
work.     The  expedition  arising  from  the  same  cause  is  not  less  remarkable. 

The  half-round  files  are  made  in  a  boss  fastened  into  the  groove  above  mentioned. 
The  steel  being  drawn  out,  is  laid  upon  the  rounded  recess,  and  hammered  till  it  fills 
the  die. 

The  three-sided  files  are  formed  similarly  in  a  boss,  the  recess  of  which  consists  of  two 
sides,  with  the  angle  downwards.  The  steel  is  first  drawn  out  square,  and  then  placed 
in  a  boss  with  an  angle  downwards,  so  that  the  hammer  forms  one  side,  and  the  boss  two. 
The  round  files  are  formed  by  a  swage  similar  to  those  used  by  common  smiths,  but  a 
little  conical. 

The  file-cutter  requires  an  anvil  of  a  size  greater  or  less,  proportioned  to  the  size  of  his 
files,  with  a  face  as  even  and  flat  as  possible.  The  hammers  weigh  from  one  to  five  or  six 
pounds.  The  chisels  are  a  little  broader  than  the  file,  sharpened  to  an  angle  of  about  20 
degrees.  The  length  is  just  sufficient  for  them  to  be  held  fast  between  the  finger  and 
thumb,  and  so  strong  as  not  to  bend  with  the  strokes  of  the  hammer,  the  intensity  of 
which  may  be  best  conceived  by  the  depth  of  the  impression.  The  anvil  is  placed  in  the 
face  of  a  strong  wooden  post,  to  which  a  wooden  seat  is  attached,  at  a  small  distance  be- 
low the  level  of  the  anvil's  face.  The  file  is  first  laid  upon  the  bare  anvil,  one  end  pro- 
jecting over  the  front,  and  the  other  over  the  back  edge  of  the  same.  A  leather  strap 
now  goes  over  each  end  of  the  file,  and  passes  down  upon  each  side  of  the  block  to  the 
workman's  feet,  which,  being  put  into  the  strap  on  each  side,  like  a  stirrup,  holds  the  file 
firmly  upon  the  anvil  as  it  is  cut.  WhUe  the  point  of  the  file  is  cutting,  the  strap  passes 
over  one  part  of  the  file  only,  the  point  resting  upon  the  anvil,  and  the  tang  upon  a  prop 
on  the  other  side  of  the  strap.  When  one  side  of  the  file  is  single  cut,  a  fine  file  is  run 
slightly  over  the  teeth,  to  take  away  the  roughness ;  when  they  are  to  be  double  cut, 
another  set  of  teeth  is  cut,  crossing  the  former  nearly  at  right  angles.  The  file  is  now 
finished  upon  one  side,  and  it  is  evident  that  the  cut  side  cannot  be  laid  upon  the  bare 
anvil  to  cut  the  other.  A  flat  piece  of  an  alloy  of  lead  and  tin  is  interposed  between  the 
toothed  surface  and  the  acvil,  while  the  other  side  is  cut,  which  completely  preserves  the 
side  already  formed.  Similar  pieces  of  lead  and  tin,  with  angular  and  rounded  grooves 
are  used  for  cutting  triangular  and  half-round  files.  ' 

Rasps  are  cut  precisely  in  the  same  way,  by  using  a  triangular  punch  instead  of  a  flat 
chisel.  The  great  art  in  cutting  a  rasp  is  to  place  every  new  tooth  as  much  as  possible 
opposite  to  a  vacancy. 

IVfany  abortive  attempts  have  been  made  to  cut  the  teeth  of  files  by  machinery.  Th* 
following  plan,  for  which  a  patent  was  obtained  by  Mr.  William  Shilton,  of  Birming- 
ham, in  April,  1833,  is  replete  with  ingenious  mechanical  resources,  and  deserves  to 
succeed. 

The  blanks  of  steel  for  making  the  files  and  rasps,  are  held  in  a  pair  of  clamps  in 
connexion  with  a  slide,  and  are  moved  forward  at  intervals  under  the  head  of  the  tilt 
hammer  which  carries  the  tool ;  the  distance  which  the  blank  is  to  be  advanced  at 
every  movement  being  dependant  upon  the  required  fineness  or  coarseness  of  the  cut  of 
the  file,  TThich  movement  is  effected  and  regulated  by  a  rack  and  pinion,  actuated  by  a 
pall  and  ratchet  wheel,  or  the  movement  may  be  produced  by  any  other  convenient 
means. 

When  the  machine  is  employed  for  cutting  or  indenting  the  teeth  of  rasps,  the  cutting 
tool  being  pointed  and  only  producing  one  tooth  at  a  blow,  the  tilt  hammer  carrying  th« 
tool  mast  be  made  to  traverse  at  intervals  across  the  width  of  the  blank  piece  of  steel 


710 


FILE. 


FILE- 


711 


from  one  edge  to  the  other  and  back  again ;  the  blank  being  advanced  m  jength  only 
when  the  hammer  has  produced  the  last  cut  or  tooth  toward  either  edge  of  the  rasp. 

In  order  to  render  this  invention  better  understood,  two  views  of  the  apparatus  for  pro- 
ducing the  cross-cut  or  teeth  of  the  files  are  given. 

Fig,  527  is  an  elevation  of  the 
upper  part  of  the  file-cutting  machine, 
as  seen  on  one  side ;  fig,  528  is  • 
plan  or  horizontal  view,  as  the  ma- 
chine appears  on  the  top. 

a,  is  the  head  of  the  lilt  hammec 
placed  in  the  end  of  the  lever  In, 
which  is  mounted  on  an  axle  c, 
turning  in  proper  bearings  in  the 
framework  of  the  machine ;  d,  is  the 
tilt  wheel  mounted  on  another  axle  s, 
also  turning  in  bearings  on  the  frame 
work  of  the  machine,  and  having  any 
required  number  of  projections  or 
tappets  npon  it  for  depressing  the  tail 
or  shorter  end  of  the  hammer  or  tilt 
lever  6. 

The  tilt  wheel  d,  receives  its  rota- 
tory motion  from  the  toothed  wheel 
/,  mounted  upon  the  same  axle,  and 
it  takes  into  gear  with  a  pinion  g, 
upon  the  main  shaft  A,  which  is  ac- 
tuated by  a  band  passed  from  any 
first  mover  to  the  rigger  on  its  end, 
or  in  any  other  convenient  manner. 
The  bed  upon  which  the  blank  piece 
of  steel  bears  is  marked  i.  This  bed 
is  firmly  supported  upon  masonry 
placed  upon  proper  sleepers ;  _;',  is 
one  of  the  blank  pieces  of  steel  under 
operation,  and  is  shown  secured  in 
the  pair  of  jaws  or  holding  clamps  fc, 
mounted  on  centre  pins  in  the  slide 
/,  fig.  528 ;  which  slide  is  held  down 
by  a  spring  and  slide  beneath,  and  is 
moved  backwards  and  forwards  in  the  machine  upon  the  (v)  edges  m,  tw,  of  the  frame, 
by  means  of  the  rack  n,  and  its  pinion ;  the  latter  being  mounted  upon  the  axle  of  the 
ratchet  wheel  |J,  and  which  ratchet  wheel  is  made  to  turn  at  intervals  by  means  of  the 
pall  g,  upon  the  end  of  the  lever  r,  fig.  528.  This  lever  is  depressed,  after  every  cut 
has  been  efi'ected  upon  the  blank  by  means  of  the  teeth  or  tappets  of  the  wheel  «,  coming 
in  contact  with  the  inclined  plane  t,  upon  the  lever  r.  The  tappet  wheel  *,  is  mounted 
upon  the  end  of  the  axle  e,  of  the  tilt  wheel,  and  consequently  revolves  with  it,  and  by 
depressing  the  lever  r,  every  time  that  a  tooth  passes  the  inclined  plane  /,  the  click  g, 
is  made  to  drive  the  ratchet  wheel  p,  and  thereby  the  advancing  movement  of  the  blank 
is  effected  after  each  blow  of  the  tilt  hammer. 

There  is  a  strong  spring  «,  attached  to  the  upper  side  of  the  tilt  hammer,  its  end  being 
confined  under  an  adjustable  inclined  plane  r,  mounted  in  the  frame  U',  which  inclined 
plane  can  be  raised  or  lowered  by  its  adjusting  screws  as  required,  to  produce  more  or 
less  tension  of  the  spring. 

A  similar  spring  is  placed  on  the  under  side  of  the  tilt  hammer,  to  raise  and  sustain 
the  cutter  or  tool  clear  of  the  bed  after  every  blow,  and  in  conjunction  with  safety  hold- 
ers or  catchers,  to  counteract  any  vibration  or  tendency  the  spring  u  may  have  to  cause 
the  hammer  to  reiterate  the  blow. 

The  end  of  the  lower  spring  acts  on  an  inclined  plane,  mounted  in  the  frame  w,  which 
has  an  adjusting  screw  similar  to  r,  to  regulate  the  tension  of  the  spring. 

In  case  the  under  spring  should  raise,  that  is,  return  the  hammer,  with  sufficient  force 
or  velocity  to  cause  the  top  spring  t*,  to  reiterate  the  blow,  the  ends  of  the  safety  holders 
or  catchers  are  made  to  move  under  and  catch  the  tail  of  the  lever  6,  immediately  on  its 
being  raised  by  the  under  springs,  whidi  is  effected  by  the  following  means  : — The  hold- 
ers are  mounted  upon  a  plate  or  carriage  1,  fig.  527,  which  turns  upon  a  small  pin  or 
axle  mounted  in  the  cars  of  a  cross  bar ;  the  upper  ends  of  the  holders  are  kept  inclined 
towards  the  tail  of  the  tilt  hammer  by  means  of^a  spring  fixed  to  the  cress  bar,  and  which 
aeu  upon  one  end  of  the  plate  or  carriage  1. 


r 


In  order  that  the  holders  may  be  removed  out  of  the  way  of  the  tail  of  the  hammer  h, 
when  the  tilt  wheel  is  about  to  effect  a  blow,  the  tooth  of  the  tilt  wheel  which  last  acted 
upon  the  hammer  comes  in  contact  with  an  inclined  plane  fixed  on  the  plate  or  carnage 
1  and  by  depressing  that  end  of  the  plate,  causes  the  upper  ends  of  the  holders  to  be 
withdrawn  from  under  the  tail  of  the  hammer  b.  The  tilt  wheel  continuing  to  revolve, 
the  next  tooth  advances,  and  depresses  the  tail  of  the  hammer,  but  before  it  leaves  the 
tail  of  the  hammer,  the  tooth  last  in  operation  will  have  quitted  the  inclined  plane  and 
allowed  the  spring  to  return  the  holders  into  their  former  position.  After  the  tooth  has 
escaped  from  the  tail  of  6,  the  hammer  will  immediately  descend  and  effect  the  blow  or 
cut  on  the  blank,  and  as  the  tail  of  the  hammer  rises,  it  will  come  in  contact  with  the 
inclined  planes  at  the  upper  ends  of  the  holders,  and  force  them  backwards ;  and  as  soon 
as  the  tail  of  the  hammer  has  passed  the  top  of  the  holders,  the  spring  will  immediately 
force  the  holders  forward  under  the  tail  of  the  hammer,  and  prevent  the  hammer  rising 
again  until  the  next  tooth  of  the  tilt  wheel  is  about  to  depress  the  end  of  the  hammer, 
when  the  same  movements  of  the  parts  will  be  repeated,  and  the  machine  will  continue 
in  operation  until  a  sufficient  length  of  the  blank  of  steel  (progressively  advanced  under 
the  hammer)  has  been  operated  upon,  when  it  will  be  thrown  out  of  gear  by  the 

following  means : —  .,.,!./•• 

Upon  the  sliding  bar  6  there  is  placed  an  adjustable  stop,  against  which  the  foremost 
end  of  the  slide  1 1,  fig.  528,  comes  in  contact  as  it  is  moved  forward  by  the  rack  n,  and 
its  pinion.  The  sliding  bar  6  is  connected  at  its  left  end  to  the  bent  lever  8,  the  other 
end  of  this  lever  being  formed  into  a  forked  arm,  which  embraces  a  clutch  upon  the  main 
shaft,  and  as  the  slide  I  continues  to  advance,  it  will  come  in  contact  with  a  slop ;  and 
when  it  has  brought  a  sufficient  length  of  the  blank  pieces  of  steel  under  the  operation 
of  the  cutting  tool,  the  slide  /,  in  its  progress,  will  have  moved  that  stop  and  the  bar  6 
forward,  and  that  bar,  by  means  of  the  bent  lever  8,  will  withdraw  the  clutch  on  the 
main  shaft,  from  locking  into  the  boss  of  the  fly-wheel,  and  consequently  stop  the  further 
progress  of  the  machine ;  the  rigger  and  fly-wheel  turning  loosely  upon  the  main  shaft. 

The  cut  file  can  now  be  removed  from  out  of  the  clamps,  and  reversed  to  cut  the  other 
side,  or  another  blank  piece  put  in  its  place ;  and  after  throwing  back  the  pall  q  of  the 
ratchet  wheel  p,  the  slide  Z,  and  with  it  the  fresh  blank  may  be  moved  back  into  the 
machine  by  turning  the  winch  handle,  on  the  axle  of  the  ratchet  wheel  p,  the  reverse 
way,  which  will  turn  the  pinion  backwards,  and  draw  back  the  rack  n,  without  affecting 
any  other  parts  of  the  machine ;  and  on  moving  back  the  bar  6,  by  the  handle  11,  placed 
on  the  stop,  the  clutches  will  be  thrown  into  gear  again,  and  the  machine  proceed  to  cut 
the  next  blank. 

When  the  blanks  have  been  thus  cut  on  one  side,  and  are  reversed  in  the  machine  to 
form  the  teeth  upon  the  other  side,  there  should  be  a  piece  of  lead  placed  between  the 
blank  and  the  bed  to  protect  the  fresh  cut  teeth. 

It  will  be  seen  that  the  position  of  the  stop  upon  the  bar  6  will  determine  the  length 
or  extent  of  the  blank  piece  of  steel  which  shall  be  cut  or  operated  upon ;  and  in  order 
that  the  progressive  movement  of  the  blanks  under  the  cutting  tool  may  be  made  to  suit 
different  degrees  of  fineness  or  coarseness  of  the  teeth  (that  is,  the  distance  between  the 
cuts),  there'is  an  adjusting  screw  upon  the  lever  r,  the  head  of  which  screw  stops  against 
the  under  side  of  an  ear  projecting  from  the  frame-work,  and  thereby  determines  the 
extent  of  the  motion  of  the  lever  r,  when  depressed  by  the  tappets  of  the  wheel  »,  acting 
upon  the  inclined  plane  /,  consequently  determining  the  number  of  teeth  the  ratchet 
wheel  p  shall  be  moved  round  by  the  pall  q ;  and  hence  the  extent  of  motion  communi- 
cated by  the  rack  and  pinion  to  the  slide  i,  and  the  blank  j,  which  regulates  the  distance 
that  the  teeth  of  the  file  are  apart,  and  the  lever  r  is  forced  upwards  by  a  spring  pressing 
against  its  under  side. 

Ii  will  be  perceived  that  the  velocity  of  the  descent  of  the  hammer,  and  consequently 
the  force  of  the  blow,  may  be  regulated  by  raising  or  lowering  the  inclined  plane  v  of  the 
spring  tt  ;  and  in  order  to  accommodate  the  bed  upon  which  the  blanks  rest  to  the  differ- 
ent inclinations  they  may  be  placed  at,  that  part  of  the  bed  is  formed  of  a  serai-globular 
piece  of  hardened  steel,  which  fits  loosely  into  a  similar  concavity  in  the  bed  r,  and  u 
therefore  capable  of  adjusting  itself  so  that  the  blanks  shall  be  property  presented  to  the 
cutting  tool,  and  receive  the  blow  or  cut  in  an  equal  and  even  manner ;  or  the  piece  of 
steel  may  be  of  a  conical  shape,  and  fit  loosely  in  a  similar  shaped  concavity. 

There  are  guides,  16,  placed  on  thr  top  of  the  bed  i,  for  the  purpose  of  keeping  the 
blanks  in  their  proper  position  towards  the  cutting  tool,  and  these  can  be  regulated  to 
suit  blanks  of  any  width,  by  turning  the  right  and  left  handed  screw  17.  There  is  also 
another  adjustable  stop  on  the  jaws  or  clamps  fe,  which  serves  as  a  guide  when  placing 
the  blanks  within  the  jaws;  and  19  is  a  handle  or  lever  for  raising  the  clamps  when 
required,  which  has  a  weight  suspended  from  it  for  the  purpose  of  keeping  down  the 
blanks  with  sufficient  pressure  upon  the  bed.  .     ,        , 

The  cutting  tool  in  the  face  of  the  hammer,  can  be  placed  at  any  required  angle  or 


712 


FILE. 


FILTRATION. 


713 


i  \Vi 


i  ■ 


inclination  with  the  blank,  it  being  secured  in  the  head  of  the  hammer  by  clamps  and 
screws.  In  cutting  fine  files  a  screw  is  employed  in  preference  to  the  rack  and  pinion, 
for  advancing  the  slide  /,  and  the  blank  piece  of  steel  in  the  machine. 

Hardening  of  files. — This  is  the  last  and  most  important  part  of  file  making.  What- 
ever may  be  the  quality  of  the  steel,  or  however  excellent  the  workmanship,  if  it  is  not 
well  hardened  all  the  labor  is  lost. 

Three  things  are  strictly  to  be  observed  in  hardening ;  first,  to  prepare  the  file  on  the 
surface,  so  as  to  prevent  it  from  being  oxydated  by  the  atmosphere  when  the  file  is  red 
hot,  which  effect  would  not  only  take  off  the  sharpness  of  the  tooth,  but  render  the 
whole  surface  so  rough  that  the  file  would,  in  a  little  time,  become  clogged  with  the 
substance  it  had  to  work.  Secondly,  the  heat  ought  to  be  very  uniformly  red  throughout, 
and  the  water  in  which  it  is  quenched,  fresh  and  cold,  for  the  purpose  of  giving  it  the 
proper  degree  of  hardness.  Lastly,  the  manner  of  immersion  is  of  great  importance,  to 
prevent  the  files  from  warping,  which  in  long  thin  files  is  very  difficult. 

The  first  object  is  accomplished  by  laying  a  substance  upon  the  file,  which,  when  it 
fuses,  forms,  as  it  were,  a  varnish  upon  the  surface,  defending  the  metal  from  the  action 
of  the  oxygen  of  the  air.  Formerly  the  process  consisted  in  first  coaling  the  surface  of 
the  file  with  ale  grounds,  and  then  covering  it  over  with  pulverized  common  salt  (muri- 
ate of  soda).  After  this  coating  became  dry,  the  files  were  heated  red  hot,  and  hardened; 
after  this,  the  surface  was  lightly  brushed  over  with  the  dust  of  cokes,  when  it  appeared 
white  and  metallic,  as  if  it  had  not  been  heated.  This  process  has  lately  been  improved, 
at  least  so  far  as  relates  to  the  economy  of  the  salt,  which,  from  the  quantity  used,  and 
the  increased  thickness,  had  become  a  serious  object.  Those  who  use  the  improved 
method  are  now  consuming  about  one  fourth  the  quantity  of  salt  used  in  the  old  method. 
The  process  consists  in  dissolving  the  salt  in  water  to  saturation,  which  is  about  three 
pounds  to  the  gallon,  and  stiffening  it  with  ale  grounds,  or  with  the  cheapest  kind  of 
flour,  such  as  that  of  beans,  to  about  the  consistence  of  thick  cream.  The  files  require 
to  be  dipped  only  into  this  substance,  and  immediately  heated  and  hardened.  The 
grounds  or  the  flour  are  of  no  other  use  than  to  give  the  mass  consistence,  and  by  that 
means  to  allow  a  larger  quantity  of  salt  to  be  laid  upon  the  surface.  In  this  method 
the  salt,  forms  immediately  a  firm  coating.  As  soon  as  the  water  is  evaporated,  the 
whole  of  it  becomes  fused  upon  the  file.  In  the  old  method  the  dry  salt  was  so  loosely 
attached  to  the  file,  that  the  greatest  part  of  it  was  rubbed  off  into  the  fire,  and  was 
sublimed  up  the  chimney,  without  producing  any  effect. 

The  carbonaceous  matter  of  the  ale  grounds  is  supposed  to  have  some  effect  in  giving 
hardness  to  the  file,  by  combining  with  the  steel,  and  rendering  it  more  highly  carbon- 
ated. It  will  be  found,  however,  upon  experiment,  that  vegetable  carbon  does  not  com- 
bine with  iron,  with  sufficient  facility  to  produce  any  effect,  in  the  short  space  of  time 
a  file  is  heating  for  the  purpose  of  hardeninff.  Some  file  makers  are  in  the  habit  of 
using  the  coal  of  burnt  leather,  which  doubtless  produces  some  effect ;  but  the  carbon 
is  generally  so  ill  prepared  for  the  purpose,  and  the  time  of  its  operation  so  short,  as  to 
render  the  result  inconsiderable.  Animal  carbon,  when  properly  prepared  and  mixed 
with  the  above  hardening  composition,  is  capable  of  giving  hardness  to  the  surface  even 
qS  an  iron  file. 

This  carbonaceous  matter  may  be  readily  obtained  from  any  of  the  soft  parts  of  ani- 
mals, or  from  blood.  For  this  purpose,  however,  the  refuse  of  shoemakers  and  curriers 
is  the  most  convenient.  After  the  volatile  parts  have  been  distilled  over,  from  an  iron 
still,  a  bright  shining  coal  is  left  behind,  which,  when  reduced  to  powder,  is  fit  to  mix 
with  the  salt.  Let  about  equal  parts,  by  bulk,  of  this  powder,  and  muriate  of  soda  be 
^ound  together,  and  brought  to  the  consistence  of  cream,  by  the  addition  of  water. 
Or  mix  the  powdered  carbon  with  a  saturated  solution  of  the  salt,  till  it  become  of 
the  above  consistence.  Files  which  are  intended  to  be  very  hard  should  be  covered 
with  this  composition  previous  to  hardening.  All  files  intended  to  file  iron  or  steel, 
particularly  saw  files,  should  be  hardened  with  the  aid  of  this  mixture,  in  preference  to 
that  with  the  flour  or  grounds.  Indeed,  it  is  probable  that  the  carbonaceous  powder 
might  be  used  by  itself,  in  point  of  economy,  since  the  ammonia  or  hartshorn,  obtained 
by  distillation,  would  be  of  such  value  as  to  render  the  coal  of  no  expense.  By  means 
of  this  method  the  files  made  of  iron,  which,  in  itself,  is  unsusceptible  of  hardening, 
acquire  a  superficial  hardness  sufficient  for  any  file  whatever.  Such  files  may,  at  the 
same  lime,  be  bent  into  any  form ;  and,  in  consequence,  are  particularly  useful  for  scnlp- 
tors  and  die-sinkers. 

The  next  point  to  be  considered  is  the  best  method  of  heating  the  file  for  hardening. 
For  this  purpose  a  fire,  similar  to  the  common  smith's  fire,  is  generally  employed.  The 
file  is  held  in  a  pair  of  tongs  by  the  tang,  and  introduced  into  the  fire,  consisting  of 
very  small  cokes,  pushing  it  more  or  less  into  the  fire  for  the  purpose  of  heating  it 
regularly.  It  must  frequently  be  withdrawn  with  the  view  of  observing  that  it  is  not 
too  hot  in  any  part.     When  it  is  uniformly  heated,  from  the  tang  to  tie  point,  of  a 


eherry  red  color,  it  is  fit  to  quench  in  the  water.  At  present  an  oven  formed  of  fire- 
bricks is  used  for  the  larger  files,  into  which  the  blast  of  the  bellows  is  directed,  bemg 
open  at  one  end,  for  the  purpose  of  introducing  the  files  and  the  fuel.  Near  to  the  top 
of  the  oven  are  placed  two  cross  bars,  on  which  a  few  tiles  are  placed,  to  be  partially 
heating.  In  the  hardening  of  heavy  files  this  contrivance  affords  a  considerable  sav- 
ing, in  point  of  time,  while  it  permits  them  also  to  be  more  uniformly  and  thoroughly 

heated.  .         ^  j        .u 

After  the  file  is  properly  heated  for  the  purpose  of  hardening,  in  order  to  produce  the 
greatest  possible  hardness,  it  shoiild  be  cooled  as  soon  as  possible.  The  most  common 
method  of  effecting  this  is  by  quenching  it  in  the  coldest  water.  Some  file-makers  have 
been  in  the  habit  of  putting  different  substances  in  their  water,  with  a  view  to  increase 
its  hardening  property.  The  addition  of  sulphuric  acid  to  the  water  was  long  held  a 
great  secret  in  the  hardening  of  saw  files.  After  all,  however,  it  will  be-found  that  clear 
spring  water,  free  from  animal  and  vegetable  matter,  and  as  cold  as  possible,  is  the  best 
calculated  for  hardening  files  of  every  description. 

In  quenching  the  files  in  water,  some  caution  must  be  observed.  All  files,  except  the 
half-round,  should  be  immersed  perpendicularly,  as  quickly  as  possible,  so  that  the  upper 
part  shall  not  cool.  This  management  prevents  the  file  from  warping.  The  half-round 
file  must  be  quenched  in  the  same  steady  manner ;  but,  at  the  same  time  that  it  is  kept 
perpendicular  to  the  surface  of  the  water,  it  must  be  moved  a  little  horizontally,  in  the 
direction  of  the  round  side,  otherwise  it  will  become  crooked  backwards. 

After  the  files  are  hardened,  they  are  brushed  over  with  water  and  powdered  cokes, 
when  the  surface  becomes  perfectly  clean  and  metallic.  They  ought  also  to  be  washed 
well  in  two  or  three  clean  waters,  for  the  purpose  of  carrying  off  all  the  salt,  which,  if 
allowed  to  remain,  will  be  liable  to  rust  the  file.  They  should  moreover  be  dipped  into 
lime-water,  and  fapidly  dried  before  the  fire,  after  being  oiled  with  olive  oil,  containing  a 
little  oil  of  turpentine,  while  still  warm.     They  are  then  finished. 

FILLIGREE  (Filigrane,  Fr. ;  FUigran,  or  Peine  Drahtgeflecht,  Germ.)  is,  as  the  last 
term  justly  expresses  it,  intertwisted  fine  wire,  used  for  ornamenting  gold  and  silver 
trinkets.  The  wire  is  seldom  drawn  round,  but  generally  flat  or  angular,  and  soldered 
by  gold  or  silver  solder  with  borax  and  the  blowpipe.  The  Italian  word,  fiiligranay  is 
compounded  of  filum  and  granum,  or  granular  net- work ;  because  the  Italians,  who  first 
introduced  this  style  of  work,  placed  small  beads  upon  it. 

FILTRATION  (Eng.  and  Fr. ;  Filtriren,  Germ.)  is  a  process,  purely  mechanical,  for 
separating  a  liquid  from  the  undissolved  particles  floating  in  it,  which  liquid  may  be  either 
the  useful  part,  as  in  vegetable  infusions,  or  of  no  use,  as  the  washings  of  mineral  pre- 
cipitates. The  filtering  substance  may  consist  of  any  porous  matter  in  a  solid,  folia- 
ted, or  pulverulent  form  ;  as  porous  earthenware,  unsized  paper,  cloth  of  many  kinds,  or 
sand.  The  white  blotting  paper  sold  by  the  stationers,  answers  extremely  well  for  filters 
in  chemical  experiments,  provided  it  be  previously  washed  with  dilute  muriatic  acid,  to 
remove  some  lime  and  iron  that  are  generally  present  in  it.  Filter  papers  are  first  cut 
square,  and  then  folded  twice  diagonally  into  the  shape  of  a  cornet,  having  the  angular 
parts  rounded  off.  Or  the  piece  of  paper  being  cut  into  a  circle,  may  be  folded  fan-like 
from  the  centre,  with  the  folds  placed  exteriorly,  and  turned  out  sharp  by  the  pressure  of 
the  finger  and  thumb,  to  keep  intervals  between  the  paper  and  the  funnel  into  which  it 
IS  fitted,  to  favor  the  percolation.  The  diameter  of  the  funnel  should  be  about  three 
fourths  of  its  height,  measured  from  the  neck  to  the  edge.  If  it  be  more  divergent,  the 
slope  will  be  too  small  for  the  ready  efflux  of  the  fluid.  A  filter  covered  with  the  sedi- 
ment is  most  conveniently  washed  by  spouting  water  upon  it  with  a  little  syringe.  A 
small  camel's-hair  paint  brush  is  much  employed  for  collecting  and  turning  over  the  con- 
tents in  their  soft  state.  Agitation  or  vibration  is  of  singular  efficacy  in  quickening  per- 
colation, as  it  displaces  the  particles  of  the  moistened  powders,  and  opens  up  the  pores 
which  had  become  closed.  Instead  of  a  funnel,  a  cylindrical  vessel  may  be  employed, 
having  its  perforated  bottom  covered  with  a  disc  of  filtering  powder  folded  up  at  the 
edges,  and  made  light  there  by  a  wire  ring.  Linen  or  calico  is  used  for  weak  alkaline 
liquors ;  and  flannels,  twilled  woollen  cloth,  or  felt-stuff,  for  weak  acid  ones.  These 
filter  bags  are  often  made  conical  like  a  fool's  cap,  and  have  their  mouths  supported  bf  a 
wooden  or  metallic  hoop.  Cotton  wool  put  loose  into  the  neck  of  a  funnel  answers  well 
for  filtering  oils  upon  the  small  scale.  In  the  large  way,  oil  is  filtered  in  conical  woollen 
bags,  or  in  a  cask  with  many  conical  tubes  in  its  bottom,  filled  with  tow  or  cotton  wool. 
Stronger  acid  and  alkaline  liquors  must  be  filtered  through  a  layer  of  pounded  glass, 
quartz,  clean  sand,  or  bruised  charcoal.  The  alcarrhazas  are  a  porous  biscuit  of  stone 
ware  made  in  Spain,  which  are  convenient  f  r  filtering  water,  as  also  the  porous  filtering 
stone  of  Teneriffe,  largely  imported  into  England  at  one  time,  but  now  siiperseded  ma 
great  measur  eby  the  artificial  filters  patented  under  many  forms,  consisting  essentially 
of  siraia  of  e:ravel,  sand,  and  charcoal  powder.  r  t     -j 

It  is  convenient  to  render  the  filter  self-acting,  by  accommodating  the  supply  of  liqu«| 


1 


714 


FILTRATION. 


FILTRATION. 


715 


to  the  rate  of  percolation,  so  that  the  pressure  upon  the  porous  surface  may  be  always 
equally  great.  Upon  the  small  scale,  the  lamp-fountain  or  birdVglass  form,  so  generally 
used  for  lamps,  will  be  found  to  answer. 

Fig.  529  represents  a  class  bottle,  a,  partly  filled  with  the  fluid  to  be  filtered,  supported 
in  the  ring  of  a  chemical  stand,  and  having  its  mouth  inverted  into  the  same  liquor  in 
the  filter  funnel.  It  is  obvious  that  whenever  this  liquor  by  filtration  falls  below  the 
lip  of  the  boille,  air  will  enter  into  it.  let  down  a  fresh  supply  to  feed  the  filter,  and 
keep  the  funnel  regularly  charged.    If  larger  quantities  are  to  be  operated  upon,  the 

following  apparatus  may 
be  employed.  Fig.  530, 
A  B,  is  a  metallic  vessel 
which  may  be  made  air- 
tight ;  c  is  the  under  pipe, 
provided  with  a  stopcock, 
R,  for  letting  down  the 
liquor  into  the  filter  a  6. 
The  upper  pipe  /,  through 
which  the  fluid  is  poured 
by  means  of  the  funnel  e, 
has  also  a  stopcock  which 
opens  or  shuts,  at  the 
same  time,  the  small  side 
tube  u  tf  through  which, 
during  the  entrance  of  the 
fluid,  the  air  is  let  off  from 
the  receiver.  A  glass 
tube,  g,  shows  the  level 
of  the  liquor  in  the  body 
of  the  apparatus.  In  using 
it,  the  cock  r  must  be  first 
closed,  and  the  cock  s 
must  be  opened  to  fill  the 
receiver.  Then  the  filter 
is  set  a  going,  by  re-open- 
ing the  cock  R,  so  as  to  keep  the  fluid  in  the  filter  upon  a  level  with  the  opening  of  the 
tube  c.  Both  these  pieces  of  apparatus  are  essentially  the  same. 
In  many  manufactures,   self-acting  filters   are   fed   by  the  plumber's  common  con- 

533  531 


I 


! 


triytnce  of  a  ball-cock,  in  which  the  sinking   and  rising   of  the  ball,  within   certain 

limits,  serves  to  open  or 

532  _       nil'  I  I  shut   off  the    supply    o| 

liquor,  as  it  may  be  re- 
quired or  not.  Dumont 
has  adopted  this  expedient 
for  his  system  of  filtering 
sirup  through  a  stratum  of 
granularly  ground  animal 
charcoal  or  bone-black. 
Fig.  531  is  a  front  view 
of  this  apparatus  with  4 
filters,  c ;  and^^.  532  is  a 
cross  section.  The  frame- 
work B  supports  the  cis- 


tern  a,  in  which  the  sirup  is  contained.    From  it  the  liquor  flows  through  the  stopcoek 


6,  and  the  connexion-tube  a,  into  the  common  pipe  c,  which  communicates,  by  the  short 
branch  tubes  «,  with  each  of  the  four  filters.  The  end  of  the  branch  tube,  which  is  inside 
of  the  filler  tub,  is  provided  with  a  stop-cock  d  /,  whose  opening,  and  thereby  the  efflux 
of  tne  liquor  from  the  cistern  through  the  tube  a,  is  regulated  by  means  of  the  float-ball  g. 
Upon  the  brickwork  d  the  filter  tub  stands,  furnished  at  h.  with  a  false  bottom  of  zinc  or 
copper  pierced  with  fine  holes ;  besides  which,  higher  up  at  t  there  is  another  such  plate 
of  metal  furnished  with  a  strong  handle  fc,  by  which  it  may  be  removed,  when  the  bone 
black  needs  to  be  changed.  In  the  intervening  space  /,  the  granular  coal  is  placed,  o  is 
the  cover  of  the  filter  tub,  with  a  handle  also  for  lifting  it.  One  portion  of  it  may  be  rais- 
ed by  a  hinge,  when  it  is  desired  to  inspect  the  progress  of  the  filtration  within,  m  m  is  a 
slender  vertical  tube,  forming  a  communication  between  the  bottom  part  A,  and  the  upper 
portion  of  the  filter,  to  admit  of  the  easy  escape  of  the  air  from  that  space,  and  from  among 
the  bone  black  as  the  sirup  descends  ;  otherwise  the  filtration  could  not  go  on.  p  is  the 
stopcock  through  which  the  fluid  collected  in  the  space  under  h,  is  let  off  from  time  to  time 
into  the  common  pipe  g,^g.  531.  r  is  a  trickling  channel  or  groove  lying  parallel  to  the 
tube  9,  and  in  which,  by  means  of  a  tube  «,  inserted  at  pleasure,  the  sirup  is  drawn  off 
in  case  of  its  flowing  in  a  turbid  state,  when  it  must  be  returned  over  the  surface  of  the 
charcoal. 

The  celerity  with  which  any  fluid  passes  through  the  filter  depends,  1.  upon  the  porosi- 
ty o{  the  filtering  substance ;  2.  upon  the  pressure  exercised  upon  it ;  and  3.  upon  the  ex- 
tent of  the  filtering  surface.  Fine  powders  in  a  liquor  somewhat  glutinous,  or  closely 
compacted,  admit  of  much  slower  filtration  than  those  which  are  coarse  and  free ;  and  the 
former  ought,  therefore,  to  be  spread  in  a  thinner  stratum  and  over  a  more  extensive  sur- 
face than  the  latter,  for  equal  effect ;  a  principle  well  exemplified  in  the  working  of  Da- 
monl's  apparatus,  just  described. 

In  many  cases  filtration  may  be  accelerated  by  the  increase  of  hydrostatic  or  pneu- 
matic pressure.  This  happens  when  we  close  the  top  of  a  filtering  cylinder,  and  con- 
nect it  by  a  pipe  with  a  cistern  of  fluid  placed  upon  a  higher  level.  The  pressure  of  the 
air  may  be  rendered  operative  also  either  by  withdrawing  it  partially  from  a  close 
vessel,  into  which  the  bottom  of  the  filter  enters,  or  by  increasing  its  density  over  the 
top  of  the  liquor  to  be  filtered.  Either  the  air  pump  or  steam  may  be  employed  to 
create  a  partial  void  in  the  receiver  beneath  the  filter.  In  like  manner,  a  forcing  pump 
or  steam  may  be  employed  to  exert  pressure  upon  the  surface  of  the  filtering  liquor.  A 
common  syphon  may,  on  the  same  principle,  be  made  a  good  pressure  filter,  by  making 
its  upper  leg  trumpet-shaped,  covering  the  orifice  with  filter  paper  or  cloth,  and  filling 
the  whole  with  liquor,  the  lower  leg  being  of  such  length  so  as  to  create  considerable 
pressure  by  the  difference  of  hydrostatic  level.  This  apparatus  is  very  convenient  either 
on  the  small  or  great  scale,  for  filtering  off  a  clear  fluid  from  a  light  muddy  sediment. 
The  pressure  of  the  atmosphere  may  be  elegantly  applied  to  common  filters,  by  the  appa- 
ratus represented  in^g.  533,  which  is  merely  a  funnel  enclosed  within  a  gasometer.  The 
case  A  B  bears  an  annular  hollow  vessel  o  6,  filled  with  water,  in  which  receiver  the  cyl- 
indrical gasometer  (i,  e,  /,  t,  is  immersed.  The  filter  funnel  is  secured  at  its  upper 
edge  to  the  inner  surface  of  the  annular  vessel  a  h.  In  consequence  of  the  pressure  of 
the  gasometer  regulated  by  the  weight  g,  upon  the  air  enclosed  within  it,  the  liquid  is 
equally  pressed,  and  the  water  in  the  annular  space  rises  to  a  corresponding  height  on  the 
outer  surfcij?  of  the  gasometer,  as  shown  in  the  figure.  Were  the  apparatus  made  of 
wheet  iron,  the  annular  space  might  be  charged  with  mercury. 

In  general,  relatively  to  the  application  of  pressure  to  filters,  it  may  be  remarked, 
that  it  cannot  be  pushed  very  far,  without  the  chance  of  deranging  the  apparatus,  or 
rendering  the  filtered  liquor  muddy.  The  enlargement  of  the  surface  is,  generally 
speaking,  the  safest  and  most  eflicacious  plan  of  increasing  the  rapidity  of  filtration, 
especially  for  liquids  of  a  glutinous  nature.  This  expedient  is  well  illustrated  in  the  creased 
bag  filter  now  in  use  in  most  of  the  sugar  refineries  of  London.     See  Sugar. 

In  many  cases  it  is  convenient  so  to  construct  the  filtering  apparatus,  as  that  the 
liquid  shall  not  descend,  but  mount  by  hydrostatic  pressure.  This  method  has  two 
advantages  :  1.  that  without  much  expensive  apparatus,  any  desired  degree  of  hydro- 
static pressure  may  be  given,  as  also  that  the  liquid  may  be  forced  up  through  several  fil- 
tering surfaces  placed  alongside  of  each  other ;  2.  that  the  object  of  filtering,  which  is  to 
separate  the  particles  floating  in  the  fluid  without  disturbing  the  sediment,  may  be  per- 
fectly attained,  and  thus  very  foul  liquids  be  cleared  without  greatly  soiling  the  filtering 
surface. 

Such  a  construction  is  peculiarly  applicable  to  the  purification  of  water,  either  alone, 
or  combined  with  the  downwards  plan  of  filtration.  Of  the  former  variety  an  example 
is  shown  in  fig,  534.  The  wooden  or  zinc  conical  vessel  is  provided  with  two  per- 
forated bottoms  or  sieves  e  e,  betwixt  which  the  filtering  substance  is  packed.  Over 
this,  for  the  formation  of  the  space  h  A,  there  is  a  third  shelf,  with  a  hole  in  its  diddle, 
through  which  the  lube  d  6  is  passed,  so  as  to  be  water  tight.    This  places  the  upper 


716 


FILTRATION. 


FIRE  ARMS. 


717 


I 


I 


open  part  of  the  apparatus  in  communicaiion  with  the  lowest  space  a.  From  the  com* 
partment  h  h  &  small  air  tube  /  runs  upwards.  The  filtering  substance  consists  at  bottom 
of  pebbles,  in  the  middle  of  gravel,  and  at  the  top  of  fine  sand,  which  may  be  mixed  with 
coarsely  ground  bone  black,  or  covered  with  a  layer  of  the  same.  The  water  to  be  filter- 
ed being  poured  into  the  cistern  at  top,  fills  through  the  tube  6  d  the  inferior  compartment 
a,  from  which  the  hydrostatic  pressure  forces  the  water  upward  through  the  perforated 
shelf,  and  the  filtering  materials.  The  pure  water  collects  in  the  space  h  A,  while  the  air 
escapes  by  the  small  tube  /,  as  the  liquid  enters.  The  stopcock  t  serves  to  draw  off  the 
filtered  water.  As  the  motion  of  the  fluid  in  the  filter  is  slow,  the  particles  suspended  in 
it  have  time  to  subside  by  their  own  gravity  ;  hence  there  collects  over  the  upper  shelf  at 
d,  as  well  as  over  the  under  one  at  a,  a  precipitate  or  deposite  which  may  be  washed  out 
of  the  latter  cavity  by  means  of  the  stopcock  m. 

As  an  example  of  an  upwards  and  downwards  filter, ^g.  535  may  be  exhibited,    a  b  cd 


535 


JP 


'm 


■■■■■■HKji^amaMn 


a 


I 


E 


vf  a  n    \% 


'•»}i)iHI»)W)}))»}>}>l}>ll}rTTT7Tt 


534 


I 


is  a  wooden  or  metallic  cistern  fur- 
nished with  the  perforated  shelf 
c  d  near  its  under  part,  upon  which 
a  vertical  partition  is  fixed  through 
the  axis  of  the  vessel.  A  semi- 
circular perforated  shelf  is  placec 
at  a,  and  a  second  similar  one  at 
6.  These  horizontal  shelves  rest 
upon  brackets  in  the  sides  of  the 
cisterns,  so  that  they  may  be  read- 
ily lifted  out.  The  space  g  is 
filled  with  coarse  sand,  J  with  mod- 
erately fine,  and  h  with  very  fine. 
The  foul  water  is  poured  into  the 
chamber  £,  and  presses  through 
G  J  H  and  into  the  space  f  ;  whence 
it  may  be  drawn  by  the  stop- 
cock/. 

JFig.  536  represents  in   section  a  filtering  apparatus   consisting  of  two    concentric 
chambers;  the  interior  being  destined  for  downwards  filtration,  and  the  exterior  for 
Within  the  larger  cistern  a,  a  smaller  one  b  is  placed  concentrically,  with  its 

under  part,  and  is  left  open  from 
H  distance  to  distance,  to  make  a 
communication  between  the  in- 
terior cavity  and  the  exterior 
annular    space.      These     cavities 


Jc 


upwards 
536 


to    the  marked    height 

sand     and     gravel.        The 

cylindrical   space   has   fine 

below,   then    sharper    sand 

granular     charcoal,     next 

sand,   and    lastly    gravel. 


are  filled 
with 
inner 
sand 
with 
coarse 

The  annular  space  has  in  like 
manner  fine  sand  below.  The 
foul  water  is  introduced  by  the 
pipe  £,  the  orifice  at  whose  end 
is  acted  upon  by  a  ball-cock 
with  its  lever  a ;  whereby  the 
water  is  kept  always  at  the  same 
level  in  the  inner  vessel.  The  water  sinks  through  the  sand  strata  of  the  middle  vessel, 
passes  outwards  at  its  bottom  into  the  annular  space,  thence  up  through  the  sand  in  it, 
and  collecting  above  it,  is  let  off  by  the  stopcock  on  the  pipe  h.  When  a  muddy  deposite 
forms  after  some  time,  it  may  be  easily  cleared  out.  The  cord  «,  running  over  the  pulleys 
//,  being  drawn  tight,  the  ball  lever  will  shut  up  the  valve.  The  stopcock  d  made  fast 
to  the  conducting  tube  e  must  then  be  opened,  so  that  the  water  now  overflows  into  the 
annular  space  at  a  ;  the  tube  c,  in  communication  with  the  inner  space  b,  being  opened 
by  taking  out  the  stopper  h.  The  water  thereby  percolates  through  the  sand  strata  in  the 
reverse  direction  of  irj  usual  course,  so  as  to  clear  away  the  impurities  in  the  space  b,  and 
to  discharge  them  by  the  pipe  c  h.  An  apparatus  of  this  kind  of  moderate  size  is  capable 
of  filtering  a  great  body  of  water.  It  should  be  constructed  for  that  purpose  of  masonry  ; 
but  upon  a  small  scale  it  may  be  made  of  stone- ware. 

A  convenient  apparatus  for  filtering  oil  upwards  is  represented  in^g.  537.  g  is  an  oil 
eosk,  in  which  the  impure  parts  of  the  oil  have  accumulated  over  the  bottom.  Imme- 
diately above  this,  a  pipe  a  is  let  in,  which  communicates  with  an  elevated  water  cistern 


•     f  is  the  filter  (placed  on  the  lid  of  the  cask),  furnished  with  two  perforated  shelves, 
oie  at  t  and  another  at  d;  which  divide  the  interior  of  the  filter  into  t»ree  <5o»n. 

partments.  Into  the  lower  space  immedmtely  over  the  shelf  «, 
the  tube  6,  furnished  with  a  stopcok,  enters,  to  establish  a 
communicaiion  with  the  cask  ;  the  middle  cavity  t  is  filled  with 

.  coarsely  ground  charcoal  or  other  filtering  materials ;  and  the 

"11  ^iMrfK     upper  one  has  an  eduction  pipe,  /.    When  the  stopcocks  of  the 

<M  HMH.         ^y|,gg  ^  jjnd  6  are  opened,  the  water  passes  from  the  cistern  into 

the  oil  cask,  occupies  from  its  density  always  the  lowest  place, 
and  presses  the  oil  upwards,  without  mixing  the  two  liquids; 
whereby  first  the  upper  and  purer  portion  of  the  oil  is  forced 
through  the  tube  6  into  the  filter,  and  thence  out  through  the 
pipe  Z.  When  the  fouler  oil  follows,  it  deposites  its  impurities 
in  the  space  under  the  partition  c,  which  may  from  time  to  time 
be  drawn  off  through  the  stopcock  fe,  while  the  purer  oil  is 
pressed  upwards  through  the  filter.  In  this  way  the  different 
strata  of  oil  in  the  cask  may  be  filtered  off  in  succession,  and 
^.  .   .  kept  separate,  if  found  necessary,  for  sale  or  use,  without  run- 

nin<r  anv  risk  of  mixin?  up  the  muddy  matter  with  what  is  clear.  According  to  the 
heilht  of  the  water  cistern  n,  will  be  the  pressure,  and,  of  course,  the  filtering  force. 
When  the  filter  gels  choked  with  dirt,  it  may  be  easily  recharged  with  fresh  materials. 

In  filtering  caustic  alkaline  leys  through  linen  or  quartz,  it  is  proper  to  exclude  the 
free  contact  of  air;  which  is  done  by  enclosing  the  upper  vessel,  and  attaching  a  pipe  of 
communication  between  its  cover  and  the  shoulder  of  the  l<>^^"7t'l°'r"P'«"'/I  v« 
leys.  In  proportion  as  these  flow  down,  they  will  displace  their  bulk  of  air,  and  drive 
it  into  the  top  of  the  upper  vessel  above  the  foul  leys.  ,    •    »u-    ««„«t«r. 

Many  modifications  of  the  above  described  apparatus  are  now  on  sale  in  this  countiy, 
but  certainly  the  neatest,  most  economical,  and  effective  means  of  transforming  the  water 
of  a  stagnant  muddy  pool  into  that  of  a  crystalline  fountam,  is  afforded  by  the  Royal 

Patent  Filters  of  George  Robins.  .,..,,...      v        u      ♦i,  ♦  ^r  «».- 

FIRE  ARMS,  Manufacture  of.  This  art  is  divided  into  two  branches  that  of  the 
metallic  and  of  the  wooden  work.  The  first  includes  the  barrel,  the  lock,  and  the  mount- 
ing, as  also  the  bayonet  and  ramrod,  with  military  arms.  The  second  comprises  the  stock, 
and  in  fowling  pieces,  likewise  the  ramrod. 

1.  The,  Barrel.    Its  interior  is  called  the  bore;  Us  diameter,  the  calibre ;  the  back 
end,  the  breech ;  the  front  end,  the  muzzle ;  and  the  closing  of  the  back  end,  the  breech 
Din  or  pluc.    The  barrel  is  generally  made  of  iron.    Most  military  muskets  and  low- 
priced  guns  are  fashioned  out  of  a  long  slip  of  sheet-iron,  folded  together  edgewise 
round  a  skewer  into  a  cylinder,  are  then  lapped  over  at  the  seam,  and  welded  at  a 
while  heat.     The  most  ductile  and  tenacious  soft  iron,  free  from  aU  blemishes,  must  be 
selected  for  this  slip.     It  is  frequently  welded  at  the  common  forge,  but  a  proper  atr- 
furnace  answers  better,  not  being  so  apt  to  burn  it.     It  should  be  covered  with  ashes 
or  cinders.    The  shape  of  the  bore  is  given  by  hammering  the  cylinder  upon  a  sted 
mandril,  in  a  groove  of  the  anvil.     SLv  inches  of  the  barrel  at  either  end  are  left  open 
for  formin"  the  breeck  ind  the  muzzle  by  a  subsequent  welding  operation  ;  the  extrem- 
ity put  into  the  fire  be:ng  stopped  with  clay,  to  prevent  the  introduction  of  cinders. 
For  every  leneth  of  two  inches  there  are  from  two  to  three  welding  operations,  divided 
into  alternating  high  and  low  heats ;  the  latter  being  intended  to  correct  the  defects  of 
the  former.     The  breech  and  muzzle  are  not  welded  upon  the  mandril,  but  upon  the 
horn  of  the  anvil ;  the  breech  being  thicker  in  the  metal,  is  more  highly  heated,  and  is 
made  somewhat  wider  to  save  labor  to  the  borer.    The  barrel  is  finally  hammered  m 
the  groove  of  the  anvil  without  the  mandril,  during  which  process  it  receives  a  heat 
eveiT  two  minutes.    In  welding,  the  barrel  extends  about  one  third  in  length ;  and 
for  muskets,  is  eventually  left  from  3  to  3^  feet  long ;  but  for  cavalry  pistols,  only  9 

The  best  iron  plates  for  gun-barrels  are  those  made  of  stub  iron,  that  is,  of  old 
horse-shoe  nails  welded  together,  and  forged  into  thin  bars,  or  rather  narrow  ribands. 
At  one  time  datnascus  barrels  were  much  in  vogue ;  they  were  fashioned  either  as  aoove 
described,  from  plates  made  of  bars  of  iron  and  steel  laid  parallel,  and  welded  together, 
or  from  ribands  of  the  sauie  damascus  stuff  coiled  into  a  cylinder  at  a  red  heat,  ana  men 
welded  together  at  the  seams.  The  best  modern  barrels  for  fowling  pieces  are  con- 
structed of  stub-nail  iron  in  this  manner.  The  slip  or  fillet  is  only  half  an  inch  broad, 
or  sometimes  less,  and  is  left  thicker  at  the  end  which  is  to  form  the  breech,  an^  h.nner 
at  the  end  which  is  to  form  the  muzzle,  than  in  the  intermediate  portion.  Ihis  tiiiet 
being  moderately  heated  to  increase  its  pliancy,  is  then  lapped  round  the  mandril  m  a 
spiral  dire<.tion  till  a  proper  length  of  cylinder  is  formed;  the  edges  ^eing  made  to 
OTcrla?  a  little  in  order  to  give  them  a  better  hold  in  the  weldmg  process.    The  coi 


C^ 


718 


FIRE  ARMS. 


FIRE  ARMS. 


719 


m 


1^ 


:,: 


^ 


539 


being  taken  ofl  the  mandrU  and  again  heated,  is  struck  down  vertically  with  its  mnzzta 
end  upon  the  anvil,  whereby  the  spiral  junctions  are  made  closer  and  morT  un ifoiT  ft 
K  now  welded  at  several  successive  heats,  hammered  by  horizontal  strokes,  called  yimi. 
tng,  and  brought  into  proper  shape  on  the  mandril.  The  finer  barrels  are  made  of  «m 
narrower  siub-iron  slips,  whence  they  get  the  name  of  wire  twist.     On  the  Cont  nen 

evZtr%rrerLf '' ";"k7'«'!?  '''''^''  lengthwise,  then  coiled  spirally  n^i 
Tk  w.        f-      r   *u^  ^"^  ^^^/^^  require  to  be  made  of  thicker  iron,  and  that  of 

the  very  bes   quality,  for  they  would  be  spoiled  by  the  least  portion  of  scale  upon  thdr 

tSebayon^      '  "'"  "'  '^''^'"^  ^  ^''^'  ^'  ^^^  °»"^^»''  '^  S^^^  »  «^««t  holLg  to 

The  barrels  thus  made  are  annealed  with  a  ppntl«»  >»«.o*  ;«  «  ^«-.-      r  • 

slowly  cooled..  They  are  now  ready  for  trborerf"  s'  n  Xn^sq^T^.l/o"? 
steel,  pressed  m  Us  rotation  against  the  barrel,  by  a  slip  of  wood  applied  to  one  of  t 
fla  sides  and  held  m  its  place  by  a  ring  of  metal.  The  boring  bench  works  horizon! 
tally,  and  has  a  very  shaky  appearance,  in  respect  at  least  of  th%  "^17 some  cases 
however,  it  has  been  attempted  to  work  the  barrfk  nnH  h.».,  o*  -  •  i"  .•  '=»ses, 
horizon  of  30^  in  order  u,  Lili.ate  .he  dt h^^"  Vth'e  t^  in"s  ""Thf  ^  Jd  i  "h'elS 
u,  .  slot  l^^nly  one  pom.,  .0  allow  i.  l«  humor  .he  B,oveme'n.s  of  lheli,7er  which 

would  otherwise  be  infallibly 
broken.  The  bit,  as  repre- 
sented in  Jig.  538,  has  merely 
its  square  head  inserted  into  a 
clamp-chuck  of  the  lathe,  and 
plays  freely  through  the  rest 
of  its  length. 

Fig.  539  represents  in  plan 
the   boring   bench   for  musket 
„_.  „    r  •       ,.  .     .  barrels;  //is  the  sledge  or 

fnt  K^  u  I"^  *"  '^^"'^  ^^^  ^^''■^'  '^  supported;  a  is  the  revolving  chuck  of  the  lathe, 
i^;L7  !  .u^  ^''"•^'■^  ^"'^  ''^  *^^  ^'^'-f^^'  538,  is  inserted  ;  b  is  the  barrel,  clamped  at  it^ 
middle  to  the  carnage,  and  capable  of  being  pressed  onwards  against  the  tapering  bit  of 
ine  borer,  by  the  bent  lever  c,  worked  by  the  left  hand  of  the  operative  against  fulcrum 
KnoDs  at  rf,  which  stand  about  two  inches  asunder.  Whenever  the  barrel  has  been 
iftereby  advanced  a  certain  space  to  the  right,  the  bent  end  of  the  lever  is  shifted  against 
anoiner  knob  or  pm.  The  borer  appears  to  a  stranser  to  be  a  very  awkward  and  unsteady 
mechanism,  but  its  perpetual  vibrations  do  not  affect  the  accuracy  of  the  bore.     The 

?™'"."  fu^f  ""^^  ^^  ""^^  ^"^""^  °^  pentagonal  form,  and  either  gradually  tapered 
Irom  Its  thickest  part,  or  of  uniform  diameter  till  within  two  inches  ofthe  end,  whence 
It  IS  suddenly  tapered  to  a  point. 

j^^JsK?!,"^,^'^^  ""^^i*"  "^^"^  ^^"^  ^""*  *  ^^^^^y  beginning  with  the  smallest  and  end- 
ing with  the  largest.  But  this  multiplication  of  tools  becomes  unnecessary,  by  laying 
agBinst  the  cutting  part  of  the  bit  slips  of  wood,  called  spales,  of  gradually  increasing 
inickness,  so  that  the  edge  is  pressed  by  them  progressively  further  from  the'axis.  The 
Dore  IS  next  polished.  This  is  done  by  a  bit  with  a  very  smooth  edge,  which  is  mounted 
as  above,  with  a  w-dge  of  wood  besmeared  with  a  mixture  of  oil  and  emery.  The  inside 
IS  finished  by  workm?  a  cylindrical  steel  file  quickly  backwards  and  forwards  within  it. 
wniie  It  IS  revolving  slowly.  ' 

In  boring,  the  bit  must  be  well  oiled  or  greased,  and  the  barrel  must  be  kept  cool  by 
llnL/^  ^'■"'^1^  T  'i '  ^°''  ^^^  ^''^'  revolving  at  the  rate  of  120  or  140  times  a  minute, 
fw  «o?-*  f^^^  ^^^1  9^  ^^^^'  ^^  *  ^«^  ^^  detected  in  the  barrel  during  the  boring 
that  part  is  hammered  in,  and  then  the  bit  is  employed  to  turn  it  out. 
f\,^^J  sportsmen  are  of  opinion  that  a  barrel  with  a  bore  somewhat  narrowed  towards 
J^,.r^^  1  ^V^^  ^°  ^^^P  ^^^^  ^^"^^  together;  and  that  roughening  its  inside  with 
pounded  glass  has  a  good  effect,  with  the  same  view.     For  this  purpose,  also,  fine  spiral 

ZZ^  7  f"!  T^^  :,"  '^f''  •"'"'••«'  ^"•■^«*=^-  The  justness  of  its  calibre  is  tried  by 
^.>^?nn  h.VL"  I  -r"^  'y^'"'^"''  ^^ '*""''  3  ""'  ^  '"^^^^  '«"^'  ^hich  ought  to  movc  without 
friction,  but  with  uniform  contact  from  end  to  end  of  the  barrel.  Whatever  irregularities 
appear  must  be  immediately  removed. 

The  outer  surface  of  the  barrel  is  commonly  polished  upon  a  dry  grindstone,  but  it  is 
Jl^ritiTK  '  "^  less  dan-eTously  to  the  workman,  at  a  turning  lathe  with  a  slide  rest, 
into  Ih"  h  ^u    ^^- '      '  "^A^i  ^^  T^^  *°  '■^^^'^^  «t  the  mouth  of  a  tunnel  of  some  kind, 

moL  ninth  '  r  fh*  ^T^  u'l"^^*  '^  '."'■y  ""^  '^^  ferruginous  particles.  A  piece  of 
moist  cloth  or  leather  should  be  suspended  before  the  orifice 

Rifle  barrels  have  parallel  grooves  of  a  square  or  angularVorm  cut  within  them,  each 
groove  being  drawn  in  succession.  These  grooves  run  spirally,  and  form  each  an 
Vl^a^-^A  ?A^  revolution  from  the  chamber  to  the  muzzle.  Rifles  should  not  be  too 
deeply  indented;  only  so  much  as  to  prevent  the  ball  turning  round  within  the  barrel. 


and  the  spires  should  be  truly  parallel,  that  the  ball  may  glide  along  with  a  regular 
pace.    See  infra. 

The  Parisian  gun-makers,  who  are  reckoned  very  expert,  draw  out  the  iron  for  the 
barrels  at  hand  forges,  in  fillets  only  one  ninth  of  an  inch  thick,  one  inch  and  a  half 
broad,  and  four  feet  long.  Twenty-five  of  these  ribands  are  laid  upon  each  other,  between 
two  similar  ones  of  double  thickness,  and  the  bundle,  weighing  60  pounds,  bound  with 
wire  at  two  places,  serves  to  make  two  barrels.  The  thicker  plates  are  intended  to 
protect  the  thinner  from  the  violence  of  the  fire  in  the  numerous  successive  heats  neces- 
sary to  complete  the  welding,  and  to  form  the  bundle  into  a  bar  two  thirds  of  an  inch 
broad,  by  half  an  inch  thick ;  the  direction  of  the  individual  plates  relatively  to  the 
breadth  being  preserved.  This  bar,  folded  flat  upon  itself,  is  again  wrought  at  the 
forge,  till  it  is  only  half  an  inch  broad,  and  a  quarter  of  an  inch  thick,  while  the  plates  of 
the  primitive  ribands  are  now  set  perpendicular  to  the  breadth  of  the  narrow  fillet ;  the 
length  of  which  must  be  15  or  16  feet  French  (16  or  17  English),  to  form  a  fowling 
piece  from  28  to  30  inches  long.  This  fillet,  heated  to  a  cherry  red  in  successive 
portions,  is  coiled  into  as  close  a  spiral  as  possible,  upon  a  mandril  about  two  fiAhs 
of  an  inch  in  diameter.  The  mandril  has  at  one  end  a  stout  head  for  drawing  i  out, 
by  means  of  the  hammer  and  the  grooves  of  the  anvil,  previous  to  every  heating.  The 
welding  is  performed  upon  a  mandril  introduced  after  each  heat ;  the  middle  of  the 
barrel  being  first  worked,  while  the  fillets  are  forced  back  against  each  other,  along  the 
surface  of  the  mandril,  to  secure  their  perfect  union.  The  original  plates  having  in  the 
formation  of  the  ultimate  long  riband  become  very  thin,  appear  upon  the  surface  of  the 
barrel  like  threads  of  a  fine  screw,  with  blackish  tints  to  mark  the  junctions.  In  making 
a  double-barrelled  gun,  the  two  are  formed  from  the  same  bundle  of  slips,  the  coils  of  the 
one  finished  fillet  being  turned  to  the  right  hand,  and  those  of  the  other  to  the  left. 

The  Damascus  barrels  forged  as  above  described,  from  a  bundle  of  steel  and  iron 
plates  laid  alternately  together,  are  twisted  at  the  forge  several  times,  then  coiled  and 
welded  as  usual.  Fifteen  Parisian  workmen  concur  in  one  operation  :  six  at  the  forge ; 
two  at  the  boring  mill;  seven  at  filing,  turning,  and  adjusting;  yet  all  together  make 
only  six  pairs  of  barrels  per  week,  which  are  sold  at  from  100  to  300  francs  the  pair,  ready 
for  putting  into  the  stock. 

the  common ;  the  chamber,  plug,  or  mortar.  Jig.  540 ; 
and  the   patent.  Jig.  541.     The  common 


The  breeching  is  of  three  kinds  : 

541 


was  formerly  used  for  soldiers'  muskets 
and  inferior  pieces.  The  second  is  a 
trifling  improvement  upon  it.  In  the 
patent  breeching,  the  screvirs  do  not  in- 
terfere with  the  touch-hole,  and  the  ignition 
is  quicker  in  the  main  chamber. 

The  only  locks  which  it  is  worth  while 
to  describe  are  those  upon  the  percussion 
principle,  as  flint  locks  will  certainly  soon 
cease  to  be  employed  even  in  military 
muskets.     Forsyth's  lock  (Jig.  542)  was 


an  ingenious  contrivance. 


It 


has  a  maga- 


zine a,  for  containing  the  detonating  pow- 
der, which  revolves  round  a  roller  6,  whose 
end  is  "fecrewed  into  the  breech  of  the 
barrel.  The  priming  powder  passes  through 
a  small  hole  in  the  roller,  which  leads  to  a 
channel  in  communication  with  the  chamber 

of  the  gun. 

The  pan  for  holding  the  pninmg  is  placed  immediately  over  thelitt.e  hole  in  the  roller. 
There  is  a  steel  punch  c,  in  the  magazine,  whose  under  end  stands  above  the  pan,  ready 


:M 


720 


FIRE  ARMS. 


r»    ^ 


to  ignite  the  priming  when  struck  upon  the  top  by  the  cock  rf,  whenever  the  trigger  it 
drawn.  The  punch  immediately  aAer  being  driven  down  into  the  pan  is  raised  by  the  action 
of  a  spiral  spring.  For  each  explosion,  the  magazine  must  be  turned  so  far  round  as  to 
let  fall  a  portion  of  the  percussion  powder  into  the  pan ;  after  which  it  is  turned  back, 
and  the  steel  punch  recovers  its  proper  position  for  striking  another  blow  into  the 
pan. 

The  invention  of  the  copper  percussion  cap  was  another  great  improvement  upon  the 
detonating  plan.  Fig.  543  represents  the  ordinary  percussion  lock,  which  is  happily 
divested  of  three  awkward  projections  upon  the  flint  lock,  namely,  the  hammer,  hammer 
spring,  and  the  pan.  Nothing  now  appears  upon  the  plate  of  the  lock,  but  the  cock 
or  striking  hammer,  which  inflicts  the  proper  blow  upon  the  percussion  cap.  It  is 
concave,  with  a  small  metallic  ring  or  border,  called  a  shield  or  fence,  for  the  purpose 
of  enclosing  the  cap,  as  it  were,  and  preventing  its  splinters  doing  injury  to  the  sportsman, 
as  also  protecting  against  the  line  of  flame  which  may  issue  from  the  touch-hole  in  the 
cap  nipple.  This  is  screwed  into  the  patent  breech,  and  is  perforated  with  a  small 
hcle. 

543 


The  safety  lock  of  Dr.  Somerville  is  a  truly  humane  invention.  Its  essential  feature 
is  a  slide  stop  or  catch,  placed  under  the  trigger  a,  Jig.  544.  It  is  pulled  forward  into 
a  notch  in  the  trigger,  by  means  of  a  spring  b,  upon  the  front  of  the  guard,  which  is 
worked  by  a  key  c,  pressing  upon  the  spring  when  the  piece  is  discharged.  In  another 
safety  plan  there  is  a  small  moveable  curved  piece  of  iron,  a,  which  rises  through  an  opening 
B,  in  the  lock-plate  c,  and  prevents  the  cock  from  reaching  the  nipple,  as  represented  in 
the  figure,  until  it  is  drawn  back  within  the  plate  of  the  lock  when  the  piece  is  fired. 

544 


To  fire  this  gun,  two  different  points  must  be  pressed  at  the  same  time.  If  by 
accident  the  key  which  works  the  safety  be  touched,  nothing  happens,  because  the  trigger 
is  not  drawn  ;  and  the  trigger  touched  alone  can  produce  no  eflfect,  because  it  is  locked. 
The  pressure  must  be  applied  to  the  trigger  and  the  key  at  the  same  instant,  otherwise 
the  lock  will  not  work. 

The  French  musket  is  longer  than  the  British,  in  the  proportion  of  44*72  inches  to  4S 
but  the  French  bayonet  is  15  inches,  whereas  the  British  is  17. 


FIRE  ARMS. 

Eng.  Dimeniiont. 

Diameter  of  the  bore     -        -        -  -    0.75  in. 

Diameter  of  the  ball       ...  -     0'676 

Weight  of  the  ball  in  oz.        -        -  -      1-06 

Weight  of  the  firelock  and  bayonet  in  lbs.  -    12*25 
Length  of  the  barrel  and  bayonet  -  -   59*00 

Within  these  few  j'ears  a  great  many  contrivances  have  been 


721 


Ft.  Dimensi 
0*69  in. 
0-65 
0*958 
10*980 
69*72 
brought  forward,  and 


several  have  been  patented  for  fire  arms.  The  first  I  shall  notice  is  that  of  Charles 
Random,  Baron  de  Berenger.  Fig.  545  shows  the  lock  and  breech  of  a  fowling  piece, 
with  a  sliding  protector  on  one  of  the  improved  plans ;  a  is  the  hammer,  b  the  nipple  of 
the  touch-hole,  c  a  bent  lever,  turning  upon  a  pin,  fixed  into  the  lock-plate  at  d.  The 
upper  end  of  this  bent  lever  stands  partly  under  the  nose  of  the  hammer,  and  while  in 
that  situation  stops  it  from  striking  the  nipple.  A  slider  g  /  A,  connected  with  the  under 
part  of  the  gun-stock,  is  attached  to  the  tail  of  the  bent  lever  at  »;  and  when  the  piece 
is  brought  to  the  shoulder  for  firing,  the  hand  of  the  sportsman  pressing  against  the  bent 
part  of  the  slider  at  g,  forces  this  back,  and  thereby  moves  the  end  of  the  lever  c  forward 


from  under  the  nose  of  the  cock  or  hammer,  as  shown  by  the  dotted  lines.  The  trigger 
being  now  drawn,  the  piece  will  be  discharged ;  and  on  removing  the  hand  from  the  end 
g,  of  the  slider  /,  the  spring  at  h  acting  against  the  guard,  will  force  the  slider  forward, 
and  the  lever  into  the  position  first  described. 

Mr.  Redford,  gun-maker  of  Birminghan,  proposes  a  modification  of  the  lock  for 
small  fire-arms,  in  which  the  application  of  pressure  to  the  sear  spring  for  discharging 
the  piece  is  made  by  means  of  a  plug,  depressed  by  the  thumb,  instead  of  the  force  of 
the  finger  exerted  against  the  trigger.     Fig.  546  represents  a  fowling  piece  partly  in 


546 


-^^ 


section.  The  sear  spring  is  shown  at  a.  It  is  not  here  connected  with  the  irigger  as  Uk 
other  locks ;  but  is  attached  by  a  double-jointed  piece  to  a  lever  6,  which  turns  upon  a 
fulcrum  pin  in  its  centre.  At  the  reverse  end  of  this  lever  an  arm  extends  forwards, 
like  tjat  of  an  ordinary  sear  spring,  upon  which  arm  the  lower  end  of  the  plug  c  is 
intended  to  bear;  and  when  this  plug  is  depressed  by  the  thumb  bearing  upon  it,  that 
end  of  the  lever  b  will  be  forced  downwards,  and  the  reverse  end  will  be  raised,  so  as  to 
draw  up  the  end  of  the  sear  spring,  and  set  oflf  the  piece.  For  the  sake  of  protection, 
the  head  of  the  plug  c  is  covered  by  a  moveable  cap  d,  forming  part  of  a  slider  €,  which 
moves  to  and  fro  in  a  groove  in  the  stock,  behind  the  breech  end  of  the  barrel ;  this 
slider  e  is  acted  upon  by  the  trigger  through  levers,  which  might  be  attached  to  the  other 
side  of  the  lock-plate ;  but  are  not  shown  in  this  figare,  to  avoid  confusion.  When  the 
piece  is  brought  to  the  shoulder  for  firing,  the  fore-finger  must  be  applied  as  usual  to 
the  trigger,  but  merely  for  the  purpose  of  drawing  back  the  slider  «,  and  uncovering  the 
head  of  the  plu? ;  when  this  is  done,  the  thumb  is  to  be  pressed  upon  the  head  of  the  plug, 
and  will  thus  discharge  the  piece.  A  spring  bearing  against  the  lever  of  the  slider  e,  will, 
when  the  finger  is  withdrawn  from  the  trigger,  send  the  slider  forward  again,  and  cover 
the  head  of  the  plug,  as  shown. 

It  is  with  pleasure  I  again  advert  to  the  humane  ingenuity  of  the  Rev.  John  Somerville, 
of  Currie.  In  April,  1835,  he  obtained  a  patent  for  a  further  invention  to  prevent  the 
accidental  discharge  of  fire  arms.  It  consists  in  hindering  the  hammer  from  reaching  the 
nipple  of  a  percussion  lock,  or  the  flint  reaching  the  steel  of  an  ordinary  one,  by  the 
interposition  of  moveable  safety  studs  or  pins,  which  protrude  from  under  the  false 
breech  before  the  hammers  of  the  locks,  and  prevent  them  from  descending  to  strike. 


722 


FIRE  ARMS. 


FIRE  ARMS. 


723 


I 


I 


These  safely  stads  or  pins  are  moved  ont  of  the  way  hy  the  pressure  of  the  right  hand  ol 
the  person  using  the  gun  only  when  in  the  act  of  firing,  that  is,  when  the  force  of  lh« 
Tight  hand  and  arm  is  exerted  to  press  the  butt  end  of  the  stock  of  the  gun  against  the 
shoulder  while  the  aim  is  taken  and  the  trigger  pulled.  In  carrying  the  gun  at  rest,  the 
proper  parts  of  the  thumb  or  hand  do  not  come  over  Mr.  Somerville's  moveable  buttons  or 
studs. 

Fig.  547  is  a  side  view  of  part  of  a  double  percussion  gun  ;  and  fig,  548  is  a  lop  or 
plan  view,  which  will  serve  to  explain  these  improveraenls,  and  show  one,  out  of  many, 
methods  of  carrying  them  into  effect.  a  is  the  stock  of  the  gnn;  b  the  barrels;  c  the 
breech  ;  d  the  nipples ;  e  the  false  breech,  on  the  under  side  of  which  the  levers  which 
work  the  safety  studs  or  pins  are  placed  ;  f  is  the  shield  of  the  false  breech;  g,  triggers; 
H  the  lock-plate ;  and  i  the  hammers :  all  of  which  are  constructed  as  usual :  a  a  are 
the  safely  studs  or  pins,  which  protrude  before  the  shield  f,  and  work  through  guide 
pieces  on  the  under  side  of  the  false  breech.  The  button  piece  is  placed  in  the 
position  for  the  thumb  of  the  right  hand  to  act  upon  it ;  but  when  the  pressure  of  the 
ball  of  the  right  thumb  is  to  produce  the  movement  of  the  safety  studs,  it  must  be  placed 


in  or  near  the  position  k  ;    and  when  the  heel  of  the  right  hand  is  to  effect  the  move 
menu  of  the  safety  studs,  the  button  piece  must  be  placed  at  l,  or  nearly  so. 
548  -  -  549 


In  these  last  two  positions,  the  lever  (which  is  acted  upon  by  the  button  piece  to  work 
the  safety  studs  through  a  slide)  would  require  to  be  of  a  different  shape  and  differ- 
ently mounted.  When  the  hammers  are  down  upon  the  nipples  after  discharging  the 
gun,  the  ends  of  the  safety  pins  press  against  the  inner  sides  of  the  hammers.  When  this 
invention  is  adapted  to  single-barrelled  guns,  only  one  pin,  a,  one  lever  and  button  piece 
will  be  required. 

Mr.  Richards,  gun-maker,  Birmingham,  patented,  in  March,  1836,  a  modification  of 
the  copper  cap  for  holding  the  percussion  powder,  as  represented  fig.  549 ;  in  which 
the  powder  is  removed  from  the  top  of  the  cap,  and  brought  nearer  the  mouth ;  a  being 
the  top,  b  the  sides,  and  c  the  position  of  Ihe  priming.  The  dotted  lines  show  the  direc- 
tion of  the  explosion,  whereby  it  is  seen  that  the  metal  case  is  opened  or  distended  only 
in  a  small  degree,  and  not  likely  to  burst  to  pieces,  as  in  the  comnion  caps,  the  space 
between  a  and  c  being  occupied  by  a  piece  of  any  kind  of  hard  metal  d,  soldered  or  other- 
wise fastened  in  the  cap. 

George  Lovell,  Esq.,  director  of  the  Royal  Manufactory  of  Arms  at  Enfield,  has  re- 
cently made  a  great  improvement  upon  the  priming  chamber.  He  forms  it  into  a  verti- 
cal double  cone,  joined  in  the  middle  by  the  common  apex ;  the  base  of  the  upper  cone 
being  in  contact  with  the  percussion  cap,  presents  the  most  extensive  surface  to  the  ful- 
minate upon  the  one  hand,  while  the  base  of  the  under  one  being  in  a  line  with  the  inierior 
stkiface  of  the  barrel,  presents  the  largest  surface  to  the  gunpowder  charge,  upon  the 
other.  In  the  old  nipple  the  apex  of  the  cone  being  at  its  top,  afforded  very  injudiciously 
the  minimum  surface  to  the  exploding  force. 

Guns,  Rifling  of  the  Barreh.  —  The  outside  of  rifle  barrels  is,  in  general,  octagonal, 
AAer  the  barrel  is  bored,  and  rendered  truly  cylindrical,  it  is  fixed  upon  the  rifling 
machine.  This  instrument  is  formed  upon  a  square  plank  of  wood  7  feet  long,  to  which 
is  fitted  a  tube  about  an  inch  in  diameter,  with  spiral  grooves  deeply  cut  internally 
through  its  whole  length;  and  to  this  a  circular  plate  is  attached,  about  5  inches 
diameter,  accuralAy  divided  in  concentric  circles,  into  from  5  to  16  equal  parts,  and 
■upported  by  two  rings  made  fast  to  the  plank,  in  which  rings  it  revolves.  An  arm 
connected  with  the  dividing  graduated  plate,  and  pierced  with  holes,  through  which  a 


pin  is  passed,  regulates  the  change  of  the  tube  in  giving  the  desired  number  of  grooves 
to  the  barrel.  An  iron  rod,  with  a  moveable  handle  at  the  one  end,  and  a  steel  cutter  ia 
the  other,  passes  through  the  above  rifling  lube.  This  rod  is  covered  with  a  core  of  lead 
one  foot  long.  The  barrel  is  firmly  fixed  by  two  rings  on  the  plank,  standing  in  a  straight 
line  on  the  tube.  The  rod  is  now  drawn  repeatedly  through  the  barrel,  from  end  to  end, 
until  the  cutter  has  formed  one  groove  of  the  proper  depth.  The  pin  is  then  shifted  to 
another  hole  in  the  dividing  plate,  and  the  operation  of  grooving  is  repeated  till  the  whole 
number  of  riflings  is  completed.  The  barrel  is  next  taken  out  of  the  machine,  and  fin- 
ished. This  is  done  by  casting  upon  the  end  of  a  small  iron  rod  a  core  of  lead,  which, 
when  besmeared  with  a  mixture  of  fine  emery  and  oil,  is  drawn,  for  a  considerable  time, 
by  the  workmen,  from  the  one  end  of  the  barrel  to  the  other,  till  the  inner  surface  has 
become  finely  polished.  The  best  decree  of  spirality  is  found  to  be  from  a  quarter  to 
half  a  revolution  in  a  length  of  three  feet. 

Military  Rifles.— An  essential  improvement  in  this  destructive  arm  has  lately  been  in- 
troduced into  the  British  service  at  the  suggestion  of  Mr.  Lovell. 

The  intention  in  all  rifles  is  to  impart  to  the  ball  a  rotatory  or  spmning  motion 

round  its  axis,  as  it  passes  out  through  the  barrel.     This  object  was  attained,  to  a  certain 

degree,  in  the  rifles  of  the  old  pattern,  by  cutting  seven  spiral  grooves  into  the  inside  of 

the  barrel,  in  the  manner  shown  by  Jig.  550,  the  spherical  ball,  fig.  551,  being  a  little 

663  552  550  551 


larger  than  the  bore,  was  driven  down  with  a  mallet,  by  which  the  projecting  ribs  were 
forced  into  the  surface  of  the  ball,  so  as  to  keep  it  in  contact  with  their  curvatures,  during 
its  expulsion.  Instead  of  this  laborious  and  insecure  process,  the  barrel  being  now  cut 
with  only  two  opposite  grooves,  fig.  552,  and  the  ball  being  formed  with  a  projecting 
belt,  or  zone,  round  its  equator,  of  the  same  form  as  the  two  grooves,  fig.  553,  it  enters 
so  readily  into  these  hollows,  that  little  or  no  force  is  required  to  press  it  down  upon  the 
powder.  So  much  more  hold  of  the  barrel  is  at  the  same  time  obtained,  that  instead  of  one 
quarter  of  a  turn,  which  was  the  utmost  that  could  be  safely  given  in  the  old  way,  with- 
out danger  of  stripping  the  ball,  a  whole  turn  round  the  barrel,' in  its  length,  can  be  given 
to  the  two  grooved  rifles;  whereby  a  far  more  certain  and  complete  rotatory  motion  is 
imparted  to  the  ball.  The  grand  practical  result  is,  that  better  practice  has  been  per- 
formed by  several  companies  of  the  Rifle  Corps,  at  300  yards,  than  could  be  produced 
with  the  best  old  military  rifles  at  150  yards;  the  soldier  being  meanwhile  enabled  to  load 
with  much  greater  ease  and  despatch.  The  bell  is  bevelled  to  its  middle  line,  and  not  so 
flat  as  shown  in  the  figure. 

This  mode  of  rifling  is  not,  however,  new  in  England.  In  fact,  it  is  one  of  the 
oldest  upon  record  ;  and  appears  to  have  fallen  into  disuse  from  faults  in  the  execution. 
The  id^  was  revived  within  the   last  few  years  in  Brunswick,  and  it  was  tried  ia 


Mr.  LoveWs  Lode, 


Hanover  also,  but  with  a  lens-shaped  (Linsenformig)  ball.     The  judicious  modifications 
and  improvements  it  has  finally  received  in  Mr.  Lovell's  hands,  have  brought  out  all  its 


i 


!' 


1 

I 


it 


I 


I 


724 


FIRE  ARMS. 


advantages,  and  rendered  it,  when  skilfullj  used,  a  weapon  of  unerring  aim,  even  at  the 
prodigious  distance  of  TOO  yards. 

The  locks,  also,  for  the  military  service  generally,  are  now  receiving  an  important  im- 
provement by  means  of  his  labors,  having  been  simplified  in  a  remarkable  manner.  The 
action  of  the  main  spring  is  reversed,  as  shown  hjfig.  554;  thus  rendering  the  whole 
mechanism  more  solid,  compact,  and  convenient;  while  the  ignition  of  the  charge 
being  effected  by  percussion  powders  in  a  copper  cap,  the  fire  of  the  British  line  will, 
in  future,  be  more  murderous  than  ever,  as  a  miss-fire  is  hardly  ever  experienced  with 
the  fire-arms  made  at  the  Royal  manufactury,  under  Mr.  Lovell's  skilful  superinten- 
dence. 

Barrel-welding  hy  Machinery. — ^The  barrels  of  musquets,  birding-guns,  Ac,  or  what 
are  called  plain,  to  distinguish  them  from  those  denominated  stub  or  twisted  barrels, 
have  of  late  years  been  formed  by  means  of  rolls,  a  process  in  which  the  welding  is 
first  effected  on  a  short  slab  of  thick  iron,  and  then  the  barrel  is  brought  down  to  its 
destined  length,  and  form,  by  repeatedly  passing  it  between  a  pair  of  rolls,  that  have 
been  previously  grooved  to  the  exact  shape  of  the  barrel  intended  to  be  made. 

This  method  has  entirely  superseded  the  skelp-welding  by  hand  described  in  the 
Vic.  of  Man.,  p.  471,  and  is  conducted  as  follows  : — 

The  iron  being  thoroughly  refined,  and  reduced  into  flat  bars  by  the  process  de- 
scribed at  length  at  p.  705,  is  cut  by  the  shears  into  slabs  or  lengths  of  10  to  12  inches, 
and  10  to  10|  lbs.  weight,  or  less,  according  to  the  description  of  gun-barrel  that  i« 
intended  to  be  made.  These  slabs  are  then  heated,  and  bent  in  their  whole  length,  bj 
means  of  conveniently  grooved  bending  rolls,  until  they  assume  the  form  of  rough  tubes, 
555       of  the  kind  of  section  shown  by  Affig.  5.55.    They  are  then  placed  c*.  thf 

O  hearth  of  the  reverberatory  furnace  {Did.  p.  701),  and  brought  to  a  AiJ 
welding  heat,  and  as  soon  as  the  edges  of  a  tube  come  to  a  semi-fluid  states 
it  is  taken  out  and  passed  between  rolls  having  grooves  somewhat  smallet 
in  diameter  than  the  exterior  of  the  tube,  by  which  means  the  tuba 
is  perfectly  welded  from  end  to  end ;  and  if  care  be  taken  in  the 
management  of  the  heat,  and  the  juncture  be  kept  clear  of  dirt  and  cinders,  the  iron 
will  be  found  perfectly  homogeneous  in  every  part,  and  there  will  be  no  appearance 
whatever  of  the  seam  where  the  edges  came  together.  These  lubes  are  repeatedly 
heated,  and  passed  between  the  barrel  rolls,  which  are  of  sufficient  diameter  to  admit 
of  gradually  decreasing  grooves,  the  whole  length  of  the  intended  barrel  being  indented 
on  their  surfaces. 

To  preserve  the  tubular  form,  and  insure  regularity  in  the  size  of  the  bore  during 
the  welding  process,  they  are  taken  out  of  the  furnace,  bv  thrusting  into  them  a  tool 
called  a  mandril  b,  which  consists  of  a  long  rod  of  iron,  havmg  a  short  steel  treblett  on 
its  end,  of  the  diameter  that  the  bore  of  the  barrel  is  meant  to  bore.  This  rod  is  so 
adjusted  by  means  of  a  strong  iron  plate  c,  near  its  handle,  which  is  of  wood,  and  long, 
that  when  passed  with  the  heated  tube  on  it  between  two  tranverse  holding  bars,  the 
thort  steel  treblett  d,  shall  be  found  exactly  between  the  point  of  impact  of  the  barrel- 
rolls,  £  E. 


556 


B 


0 


The  adhesion  of  the  hot  iron  to  the  surface  of  the  rolls  is  strong  enough  to  draw  th« 
tube  off  the  mandril,  which  thus  keeps  the  bore  open  from  end  to  end,  and  by  repeating 
the  process  through  the  whole  series  of  grooves  in  the  rolls,  the  barrel  is  gradually 
elongated,  and  brought  down  to  the  exact  form  required :  any  superfluous  length  at  the 
muzzle  is  then  cut  off.  The  breach  end  is  then  adjusted  by  the  hammer — a  tripple-seat 
welded  on  by  hand  if'  it  be  intended  for  a  percussion  lock,  and  then  the  barrel  is  ready 
lo  go  forward  to  the  mill  to  be  bored,  turned,  and  finished. 

Gun-barrels  formed  by  this  mechanical  method  are  found  to  stand  proof  better  than 
(hose  worked  by  hand,  because  the  heat  is  more  equalized ;  and  any  imperfections  in 
the  original  mass  of  iron  are  more  dispersed  over  the  whole  extent  of  the  tube. 

Mr.  Wells  Ingram,  of  Bradford  street,  Birmingham,  has  lately  perfected  a  very  com- 
plete lathe  for  turning  the  exterior  of  gun-barrels  of  all  descriptions,  a  process  which  is 


FIRE  ARMS. 


725 


fast  superseding  the  use  of  the  grindstone,  for  equalising  the  barrels  of  all  kinds  of  fire- 
arm& 

I  am  indebted  for  this  article  to  Mr.  Lovell,  Director  of  the  Royal  Arms  Manufactory. 
See  MusQUET. 

Since  the  first  edition  of  the  Dictionary  large  strides  have  been  made  towards  in- 
creasing the  efficacy  of  military  fire  arms;  the  French  had  found  in  their  skirmishes 
with  Abd-el-Kader  in  Africa,  that  the  long  matchlocks  of  the  Arabs  told  at  fearful  odds 
against  their  men  at  distances  where  the  ordinary  French  musquet  was  powerless  of 
ofifence. 

After  a  while  it  was  found  that  this  increased  range  was  due  solely  to  the  greater 
elevation  taken  by  the  natives  in  aiming,  and  their  expertness  in  judging  their  dis- 
tances, taught  by  long  practice  and  experience ;  for  the  Arab  arms  and  ammunition 
taken  at  Constantine  were  found  of  the  rudest  construction. 

These  observations  led  the  French  officers  of  artillery  to  institute  all  sorts  of  experi- 
ments to  render  their  small  arms  more  effective ;  by  the  adoption  of  wall-pieces  of 
wider  bore ;  by  introducing  a  more  general  use  of  rifled  barrels,  but  at  the  same  time 
avoiding  the  tedious  method  of  loading  by  means  of  mallets  formerly  observed  with 
such  kind  of  arms. 

The  first  attempt  towards  such  object  was  that  proposed  by  M.  Delvigne,  an  oflSeer 
of  the  royal  ex-guard,  {fg,  557),  in  which  the  upper  orifice  of  the  chamber  that 


contained  the  powder  took  the  form  of  a  cup,  wherein  the  ball  (somewhat  wider  in 
diameter)  was  received,  and  by  two  or  three  smart  blows  of  a  heavy-headed  rammer  (also 
cupped  out  for  the  purpose)  became  expanded  latterly,  and  thus  the  rotary  motion  was 
imparted  to  it  by  the  spiral  grooves  of  the  barrel  in  passing  out  Colonel  Poncharra 
suggested  the  addition  of  a  wood  bottom  or  sabot  under  the  ball  and  a  greased  woollen 
patch;  and  Colonel  Thouvesino  proposed  (fg.  568)  a  steel  stem  or  pillar  about  2  inches 

558 


long  inserted  into  the  face  of  the  breech-pin;  round  this  pin,  the  charge  of  powder  was 
received,  and  the  diameter  of  the  ball,  when  resting  on  the  top  of  the  pin  was  enlarged 
by  the  blows  of  the  heavy-headed  rammer,  as  suggested  by  Delvigne. 

This  system  took  the  name  of  "  Carabine  4  Tige,"  and  has  been  very  generally  intro- 
duced for  the  service  of  fusilier  battalions  in  continental  armies;  very  grave  objections, 
however,  have  been  found  against  it  in  use,  from  the  impossibility  of  keeping  the 
chamber  (or  post  round  the  pin)  clear ;  and  from  the  severe  labor  to  the  soldier  in 
ramming  down  and  enlarging  the  diameter  of  the  ball  sufficiently  to  ensure  the  rotary 
motion  desired. 

But  if  the  ultimate  results  thus  attained  with  spherical  balls  turned  out  not  entirely 
satisfactory,  it  was  made  clearly  manifest,  in  the  course  of  the  experiments  carried  on, 
that  no  insuperable  diflSculty  stands  in  the  way  of  rendering  the  fire  of  infantry  very 
much  more  accurate  and  powerful,  by  the  use  of  rifled  barrels  throughout  the  army, 
and  thus  leading  to  a  verification  of  the  prediction  made  by  Robins  above  one  hundred 
years  ago,  that  "  whatever  state  shall  thoroughly  comprehend  the  nature  and  advan- 
tages of  rifled  barrel  pieces,  and  having  facilitated  and  completed  their  construction, 
shall  introduce  into  their  armies  their  general  use,  with  dexterity  in  the  management 
of  them,  will  by  this  means  acquire  a  superiority  which  will  almost  equal  any  thing 
that  has  been  done  at  any  time. 

But  besides  smoothing  the  way  to  such  an  essential  improvement,  it  has  been  elicited 
of  late  years,  that  when  the  accuracy  of  flight  is  secured  by  the  rotary  motion  derived 
from  the  rifling,  the  bullet,  instead  of  being  limited  to  the  form  of  a  sphere  as  hereto- 
fore, may,  up  to  certain  limits,  be  elongated  with  considerable  increase  of  destructive  ef- 
fect; and  with  an  augmentation  of  range  very  much  beyond  anything  that  has  hither- 
to been  considered  to  lie  within  the  reach  of  small  arms — placing  them,  in  fact^  with 
reference  to  artillery  and  cavalry,  in  the  first  place  instead  of  the  last. 

An  immensely  extended  field  has  thus  been  opened  to  experimenters.  Ist  Mons. 
Didon  proposed  a  true  oval  {fg.  659)  as  the  best  form  of  bullet^  so  that  when  shortened 
by  the  blows  of  the  heavy  rammer  and  widened  in  its  diameter  it  might  be  brought 
nearer  to  the  spherical  shape  before  leaving  the  barrel. 


726 


FIRE  ARMS. 


( 


■  f. 


Delvigne  took  a  patent  for  a  bullet  {fig.  560)  under  the  designntion  of 
;ivale;"  it  had  a  conical  opening  behind,  in  which  he  imagined  tliat  ihe 
owder  would  exert  itself  with  sufficient  energy  to  expand  the  lead  perma- 


2d.  Mons.  Deb 
"  Cylindro  Ogivale" 

lorce  01  iiie  powder  nuuiu  v-a^iv  iwv^ji  mvuouiiiuicub  cuciiiy  tv  cauouvi  mc  itov*  j/tin.w 
nently,  and  so  make  the  ball  take  the  rotary  movement  derived  from  the  rifling,  with- 
out any  fatigue  to  the  soldier  in  loading;  with  this  projectile,  indeed,  the  operation  ia 
but  slightly  more  difficult  than  with  the  ordinary  cartridge  and  smooth  barrels. 


}    H 


The  bullet  {fig.  661)  of  the  "  Carabine  k  Tige"  was  called  "  Cylindro  Conique,"  and 
was  said  to  possess  this  advantage  over  the  preceding,  that,  being  brought  more  to  a 
point  in  front,  it  bored  its  way  through  the  air  with  greater  ease,  and  thus  retained 
greater  velocity,  and  of  course  more  extended  range;  and  with  this  bullet  it  was  that 
Mons.  Tamisier  introduced  three  sharp-edged  channels  round  it,  which  he  stated  were 
necessary  to  keep  its  flight  steady,  by  ofi'ering  a  resistance  to  the  action  of  the  air. 

Finally  Mons.  Minie,  anofficer  of  the  French  line,  suggested  {fig.  562)  the  addition  of 
a  denoyau  or  culot  to  the  hollow  ball  of  Delvigne.  This,  in  the  form  ot  a  little  cup 
made  of  sheet  iron,  is  placed  in  the  orifice  of  the  conical  hollow  of  the  ball  behind,  and 
by  the  enei^y  of  the  powder  is  driven  into  the  ball,  enlarging  its  diameter  permanently, 
and  thus  giving  all  the  accuracy  of  the  rifle,  with  nearly  the  same  facility  of  loading  as 
with  the  plain  barrel. 

The  principle  of  the  invention,  as  thus  developed,  has,  we  learn,  been  adopted  by  our 
government  for  the  general  use  of  the  army,  seeing  that  it  offers  so  great  advantages 
over  the  system  of  plain  barrels,  but  the  bullet  {fig.  663),  as  modified  by  the  Inspector 
of  Small  Arms,  has  on  its  exterior  no  channels,  they  being  found  not  only  useless  as  to 
steadying  the  flight  of  the  projectile,  but  absolutely  injurious  in  lowering  its  velocity. 
The  bulletin  its  improved  form,  too,  being  more  truly  balanced  in  its  proportions,  and 
made  by  mechanical  means  instead  of  by  casting,  has  no  tendency  to  the  gyrations 
which  appear  to  have  so  puzzled  French  artillerists,  and  for  which  they  have  invented 
the  word  "  derivation,"  and  wasted  much  learned  disquisition. 

Though  well  satisfied  with  the  results  of  their  course  of  experiments,  our  neighbors, 
however,  do  not  appear  to  have  come  to  any  final  decision  as  yet ;  indeed,  the  fact  of 
being  able  to  make  use  of  an  elongated  projectile  with  a  rifle  has  let  loose  such  a  crowd 
of  inventors,  that  they  seem  to  be  entirely  bewildered.  In  Switzerland  every  Canton 
has  its  peculiar  form  of  bullet,  each  one,  of  course,  being  the  best,  and  from  the  length 
and  size  of  a  small  caterpillar  upwards,  every  man  seems  to  have  his  own  maggot, 
which  he  vaunts  before  the  world. 

But  even  if  it  were  ever  to  happen,  which  is  not  likely,  that  these  various  projectors 
could  be  brought  to  agree  as  to  the  best  form  of  projectile,  they  will  then  find  out, 
that  although  by  the  general  introduction  of  rifled  and  elongated  bullets  an  immense 
advantage  has  been  realised  over  plain  barrels,  their  plans,  based  as  they  all  are  upon 
a  system  of  loading  at  the  muzzle,  are  at  best  but  one  step  in  advance  ;  and  that  a  good 
sound  military  fire-arna  loading  at  the  breech  will,  after  all,  remain  the  great  desidera- 
tum— an  arm  that,  without  any  less  accuracy  or  power  to  reach  masses  of  artillery  or 
cavalry  at  a  thousand  yards'  distance,  will  enable  the  soldier  to  triple  the  quantity  of 
his  fire  at  any  moment  that  he  may  be  called  upon  to  repel  a  charge  of  cavalry  or  at 
tack  or  defend  a  breach  at  close  quarters ;  of  such  simple  construction,  and  so  easily 
handled  in  every  position  of  the  body,  that  the  soldier  can  pour  every  shot  of  his  most 
murderous  fire  upon  the  enemy  with  unerring  precision,  whilst  he  himself  may  lay 
coolly  behind  a  stone  or  in  a  ditch  in  entire  security. 

These  are  no  longer  wild  imaginings,  although  so  many  hundreds  of  attempts  towards 
the  same  object,  from  the  earliest  period  to  the  present  day,  have  been  one  a'ter  another 
seen  invariably  to  fail.  The  Germans  have  been  long  and  steadily  pursuirg  the  great 
object,  until  at  length  Herr  Dreysa,  of  Sommerda  in  Thuringia,  has  succeeded,  after 
more  than  twenty  years  of  continued  labor,  in  establbhing  a  musquet,  under  the  name 


FIRE-WORKS. 


727 


of  "Ziindnadelg^wehr,"  which  if  not  quite  perfect,  has  been  found  to  work  so  well  in 
the  hands  of  the  men,  that  the  Prussian  government  has  already  80,000  in  possession, 
and  they  are  going  on  to  arm  the  whole  of  their  line  regiments  and  Landwehr  with 
them. 

Even  with  the  assistance  of  a  diagram,  it  is  hardly  possible  to  convey  a  clear  notion 
of  the  construction  of  this  musquet,  because  the  several  parts  work  one  within  the 
other,  and  their  combination,  which  is  without  pin  or  screw,  is  hard  to  comprehend  by 
a  mere  description. 

There  is  a  strong  socket,  fig.  564),  a,  open  on  the  upper  side,  screwed  on  to  the  barrel, 

664 


665 


6,  which  is  rifled  in  the  usual  manner ;  within  this  socket  is  a  slider  c,  which  in  fact 
constitutes  the  lock,  as  it  contains  the  spiral  spring  and  mechanism  that  produces 
ignition  by  percussion ;  it  has  a  stout  hebel  or  handle,  by  which  it  is  moved  backwards 
and  forwards  freely. 

The  cartridge  {fig.  665)  consists  of  the  ball  a,  the  sabot  6,  or  bottom  of  hard  paper,  and 
holding  the  priming  matter,  and  lastly  the  charge  of  powder,  c,  the  whole 
being  made  up  in  paper  pasted  together.  In  use,  the  slider  being  drawn 
back,  the  soldier  puts  the  cartridge  with  the  point  of  the  ball  in  front  into 
the  open  breech  of  the  barrel,  pushes  the  slider  forward,  and  secures  its  close 
junction  by  a  turn  to  the  right  against  an  inclined  edge  of  the  open  socket 
The  spiral  spring  is  then  brought  into  action  (or  the  gun  is  cocked)  \>j 
pressing  the  spring  case  forward  with  the  thumb. 

On  pulling  the  trigger,  the  interior  needle,  from  which  the  musquet  takes 
its  name,  is  darted  forwai'd  through  the  charge  of  powder  into  the  percus- 
sion primer  in  the  sabot,  and  thus  efi\icts  the  ignition  inside  the  barrel 

The  principle  of  loading  at  the  breech  carries  with  it  so  many  other 
advantages  beyond  that  by  the  muzzle,  that  many  ingenious  men  are  oc- 
cupying   themselves  with  its  improvement;    Lefaucheur    and  Robert  in 
France;  Montigny  in  Belgium ;    Kufahl  Schultz  and  Friedrix  in  Prussia; 
Sears  and  Needham  in  England,  have  lately  brought  forward  various  plans; 
and  now  that  the  idea  is  taken  up  upon  a  right  base,  there  can  be  little 
doubt  that  eventually  a  system  will  be  hit  upon,  that  shall  secure  all  the 
requisites  for  military  service,  and  avoid  all  objections. 
But  it  is  clear,  from  the  recent  publications  on  gunnery  and  the  observations  of  ancient 
warriors,  that  the  advocates  for  heavy  battalion  movements,  for  drawing  up  their 
infantry  in  long  lines  and  compact  bodies  for  destruction  by  artillery,  will  be  with 
difficulty  brought  to  look  with  patience  upon  the  scrambling  and  desultory  sort  of 
warfare  which  the  general  introduction  of  these  improved  rifles  must  bring  about 
Time,  however,  daily  goes  on  to  work  wonders  upon  prejudice,  and  the  day  will  come 
when  it  will  be  found  that  cross-belts  and  blank-cartridges  may  be  abolished  without 
utter  ruin  to  the  army ;  and  that  men  behind  trees,  with  effective  weapons  in  their 
hands,  may  be  more  dangerous  enemies,  at  long  ranges,  than  when  strapped  up  and 
paraded  out  in  masses,  and  carrying  arras  that  at  any  distance  over  300  are  powerless 
of  oflFence. 
FIRE-DAMP ;  the  explosive  carburetted  hydrogen  of  coal  mines.     See  Pftcoal. 
FIRE- WORKS.     {Feux  d'artifice,   Fr.;   Feuerwerke,   Germ.)     The   composition   of 
luminous  devices  with  explosive  combustibles,  is  a  modern  art  resulting  from  the  dis- 
covery of  gunpowder.    The  finest  inventions  of  this  kind  are  due  to  the  celebrated 
Ruggieri,  father  and  son,  who  executed  in  Rome  and  Paris,  and  the  principal  capitals  of 
Europe,  the  most  brilliant  and  beautiful  fire-works  that  were  ever  seen.   The  following 
description  of  their  processes  will  probably  prove  interesting  to  many  of  my  readers. 

The  three  prime  materials  of  this  art  are,  nitre,  sulphur,  and  charcoal,  along  with  filings 
of  iron,  steel,  copper,  zinc,  and  resin,  camphor,  lycopodium,  <fcc.  Gunpowder  is  used 
either  in  grain,  half  crushed,  or  finely  ground,  for  diff'erent  purposes.  The  longer  the  iron 
filings,  the  brighter  red  and  white  sparks  they  give ;  those  being  preferred  which  are 
made  with  a  very  coarse  file,  and  quite  free  from  rust  Steel  filings  and  cast-iron  bor- 
ings contain  carbon,  and  afford  a  more  brilliant  fire,  with  wavy  radiations.  Copper 
filings  give  a  greenish  tint  to  flame ;  those  of  zinc  a  fine  blue  color ;  the  snlphuret  of 
antimony  gives  a  less  greenish  blue  than  zinc,  but  with  much  smoke ;  amber  affords 
a  yellow  fire,  as  well  as  colophony,  and  common  salt ;  but  the  last  must  be  very  dry. 
Lampblack  produces  a  very  red  color  with  gunpowder,  and  a  pink  with  nitre  in  exceaa. 


H 


U 


m 


p 


728 


FIRE-WORKS. 


It  serves  for  making  golden  showers.  The  yellow  sand  or  glistening  miaa,  communicates 
lo  fire- works  golden  radiations.  Verdigris  imparts  a  pale  green  ;  sulphate  of  copper  and 
sal-ammoniac,  a  palm-tree  green.  Camphor  yields  a  very  white  flame  and  aromatic  fumes, 
which  mask  the  had  smell  of  other  substances.  Benzoin  and  storax  are  used  also  on 
account  of  their  agreeable  odor.  Lycopodium  burns  with  a  rose  color  and  a  magnificent 
flame ;  but  it  is  principally  employed  in  theatres  to  represent  lightning,  or  to  charge  th« 
torch  of  a  fury. 

Fire- works  are  divided  into  three  classes:  1.  those  to  be  set  off  upon  the  ground;  2. 
those  which  are  shot  up  into  the  air ;  and  3.  those  which  act  upon  or  under  water. 

Composition  for  jets  o/Jire ;  the  common  preparation  for  rockets  not  more  than  |  of  an 
inch  in  diameter,  is;  gunpowder,  16  parts;  charcoal,  3  parts.  For  those  of  larger  diam- 
eter; gunpowder,  16;  steel  filings,  4. 

Brilliant  revolving  wheel ;  for  a  tube  less  than  f  of  an  inch;  gunpowder,  16;  steel 
filings,  3.    When  more  than  | :  gunpowder,  16 ;  filings,  4. 

Chinese  or  Jasmine  fire  ;  when  less  than  J  of  an  inch  :  gunpowder,  16 ;  nitre,  8 ;  char- 
coal (fine),  3  ;  sulphur,  3 ;  pounded  cast-iron  borings  (small),  10.  When  wider  than  | : 
gunpowder,  16;  nitre,  12;  charcoal,  3;  sulphur,  3;  coarse  borings,  12. 

«tf  fixed  brilliant ;  less  than  |  in  diameter :  gunpowder,  16 ;  steel  filings,  4 ;  or,  gun- 
powder, 16;  and  finely  pounded  borings,  6. 

Fixed  suns  are  composed  of  a  certain  number  of  jets  of  fire  distributed  circularly,  like 
the  spokes  of  a  wheel.  All  the  fusees  take  fire  at  once  through  channels  charged  with 
qaick  matches.  Glories  are  large  suns  with  several  rows  of  fusees.  Fans  are  portioni 
of  a  sun,  being  sectors  of  a  circle.     The  Palte  d^oie  is  a  fan  with  only  three  jets. 

The  mosaic  represents  a  surface  covered  with  diamond  shaped  compartments,  formed 
by  two  series  of  parallel  lines  crossing  each  other.  This  effect  is  produced  by  placing  at 
each  point  of  intersection,  four  jets  of  fire,  which  run  into  the  adjoining  ones.  The  in- 
tervals between  the  jets  must  be  associated  with  the  discharge  of  others,  so  as  to  keep 
up  a  succession  of  fires  in  the  spaces. 

Palm  trees.  Ruggieri  contrived  a  new  kind  of  fire,  adapted  to  represent  all  sorts  of 
trees,  and  especially  the  palm.  The  following  is  the  composition  of  this  magnificent 
green  fire-work  :  crystallized  verdigris,  4  parts  ;  sulphate  of  copper,  2 ;  sal-ammoniac,  1. 
These  ingredients  are  to  be  ground  and  moistened  with  alcohol.  An  artificial  tree  of  any 
kind  being  erected,  coarse  cotton  rovings  about  2  inches  in  diameter,  impregnated  with 
that  composition,  are  to  be  festooned  round  the  trunk,  branches,  and  among  the  leaves; 
and  immediately  kindled  before  the  spirits  have  had  time  to  evaporate. 

Cascades  imitate  sheets  or  jets  of  water.  The  Chinese  fire  is  best  adapted  to  such 
decorations. 

Fixed  stars.  The  bottom  of  a  rocket  is  to  be  stuffed  with  clay,  and  one  diameter  in 
height  of  the  first  preparation  being  introduced,  the  vacant  space  is  to  be  filled  with  the 
following  composition,  and  the  mouth  tied  up.  The  pasteboard  must  be  pierced  into  thf 
preparation,  with  five  holes,  for  the  escape  of  the  luminous  rays,  which  represent  a  star. 

Composition  affixed  stars  .•— 


Ordinary. 

Brighter. 

Colored. 

Nitre   - 

-    16 

12 

0 

Sulphur 

-      4 

6 

6 

Gunpowder  meal 

-      4 

12 

16 

Antimony 

-      2 

1 

2 

Lances  are  long  rockets  of  small  diameter,  made  with  cartridge  paper.  Those  which 
bum  quickest  should  be  the  longest.  They  are  charged  by  hand  without  any  mould, 
with  rods  of  different  lengths,  and  are  not  strangled  at  the  mouth,  but  merely  stuffed  with 
a  quick  match  of  tow.  These  lances  form  the  figures  of  great  decorations;  they  are 
fixed  with  sprigs  upon  large  wooden  frame  works,  representing  temples,  palaces,  pago- 
das, &c.  The  whole  are  placed  in  communication  by  conduits,  or  small  paper  cartridges 
like  the  lances,  but  somewhat  conical,  that  they  may  fit  endwise  into  one  another  to  any 
extent  that  may  be  desired.  Each  is  furnished  with  a  match  thread  fully  ]|  inches  long, 
at  its  two  ends. 

Composition  for  the  white  lances :  nitre,  16 ;  sulphur,  8 ;  gunpowder,  4  or  3.  For  a 
Uuish-white :  nitre,  16 ;  sulphur,  8 ;  antimony,  4.  For  blue  lances  :  nitre,  16 ;  antimony, 
B.  Foi-  yellow:  nitre,  16;  gunpowder,  16;  sulphur,  8;  amber,  8.  For  yellower  ones: 
nitre,  16 ;  gunpowder,  16 ;  sulphur,  4 ;  colophony,  3 ;  amber,  4.  For  greenish  ones :  nitre, 
16;  sulphur,  6;  antimony,  6 ;  verdigris,  6.  For  pink  lances  :  nitre,  16;  gunpowder,  3; 
lampblack,  1.  Others  less  vivid  are  made  with  nitre,  16;  colophony,  3;  amber,  3  ;  ly- 
copodium, 3. 

Cordage  is  represented  in  fire-works,  by  imbuing  soft  ropes  with  a  mixture  of  nitre,  2 ; 
sulphur,  16 ;  antimony,  1 ;  resin  of  juniper,  1. 


FIRE-WORKS. 


729 


The  Bengal  flames  rival  the  light  of  day.  Tliey  consist  of,  nitre,  7  ;  sulphur,  2;  an- 
timony, 1.  This  mixture  is  pressed  strongly  into  earthen  porringers,  with  some  bits 
of  quick  match  strewed  over  the  surface.  These  flames  have  a  fine  theatrical  effect  for 
conflagrationa 

Revolving  suns,  are  wheels  upon  whose  circumference  rockets  of  different  styles  are 
fixed,  and  which  communicates  by  conduits,  so  that  one  is  lighted  up  in  succession  after 
another.  The  composition  of  their  common  fire  is,  for  sizes  below  |  of  an  inch  :  gun- 
powder meal,  16;  charcoal,  not  too  fine,  8.  For  larger  sizes:  gunpowder,  20;  char- 
'*.oal,  not  too  fine.  4.  Yor fiery  radiations:  gunpowder,  16;  yellow  micaceous  sand,  2 
or  3.     For  mixed  radiatio}<,/< :  gunpowder,  16:  pitcoal,  1;  yellow  sand,  1  or  2. 

The  waving  or  double  Cviherine  wheels,  are  two  suns  turning  about  the  same  axis  in 
opposite  directions.  The  fusees  are  fixed  obliquely  and  not  tangentially  to  their  peri- 
pheries. The  wheel  spokes  are  charged  with  a  great  number  of  fusees ;  two  of  the  four 
wings  revolve  in  the  one  direction,  and  the  other  two  in  the  opposite;  but  always  in 
a  vertical  plane. 

The  girandoles,  caprices,  spirals,  and  some  others  have  on  the  contrary  a  horizontal 
rotation.  The  fire-worker  may  diversify  their  effects  greatly  by  the  arrangement  and 
color  of  the  jets  of  flame.  Let  us  take  for  an  example  the  globe  of  light.  Imagine  a 
large  sphere  turning  freely  upon  its  axis,  along  with  a  hollow  hemisphere,  which  re- 
volves also  upon  a  vertical  axis  passing  through  its  under  pole.  If  the  two  pieces  be 
covered  with  colored  lances  or  cordage,  a  fixed  luminous  globe  will  be  formed,  but  if 
horizontal  fusees  be  added  upon  the  hemisphere,  and  vertical  fusees  upon  the  sphere, 
the  first  will  have  a  relative  horizontal  movement,  the  second  a  vertical  movement, 
which  being  combined  with  the  first,  will  cause  it  to  describe  a  species  of  curve,  whose 
effect  will  be  an  agreeable  contrast  with  the  regular  movement  of  the  hemisphere. 
Upon  the  surface  of  a  revolving  sun,  smaller  suns  might  be  placed,  to  revolve  like  sat- 
ellites round  the  primaries. 

Ruggieri  exhibited  a  luminous  serpent  pursuing  with  a  rapid,  winding  pace  a  but- 
terfly which  flew  continually  before  it  This  extraordinary  effect  was  produced  in  the 
following  way.  Upon  the  summits  of  an  octagon  he  fixed  eight  equal  wheels  turning 
freely  upon  their  axles,  in  the  vertical  plane  of  the  octagon.  An  endless  chain  passed 
round  their  circumference,  going  from  the  interior  to  the  exterior,  covering  the  out- 
side semi-circumference  of  the  first,  the  inside  of  the  second,  and  so  in  succession ; 
whence  arose  the  appearance  of  a  great  festooned  circular  line.  The  chain  like  that  of 
a  watch,  carried  upon  a  portion  of  its  length  a  sort  of  scales  pierced  with  holes  for  re- 
ceiving colored  lances,  in  order  to  represent  a  fiery  serpent.  At  a  little  distance  there 
was  a  butterfly  constructed  with  white  lances.  The  piece  was  kindled  commonly  by 
other  fire-works,  which  seemed  to  end  their  play,  by  projecting  the  serpent  from  the 
bosom  of  the  flames.  The  motion  was  communicated  to  the  chain  by  one  of  the  wheels, 
which  received  it  like  a  clock  from  the  action  of  a  weight  This  remarkably  curious 
mechanism  was  called  by  the  artists  a  salamander. 

The  rockets  which  rise  into  the  air  with  a  prodigious  velocity,  are  among  the  most 
common,  but  not  least  interesting  fire-works.  When  employed  profusely  they  form 
those  rich  volleys  of  fire  which  are  the  crowning  ornaments  of  a  public  f^te.  The 
cartridge  is  similar  to  that  of  the  other  jets,  except  in  regard  to  its  length,  and  the  ne- 
cessity of  pasting  it  strongly,  and  planing  it  well ;  but  it  is  charged  in  a  different  man- 
ner. As  the  sky-rockets  must  fly  off  with  rapidity,  their  composition  should  be  such 
as  to  kindle  instantly  throughout  their  length,  and  extricate  a  vast  volume  of  elastic 
fluids.  To  effect  this  purpose,  a  small  cylindric  space  is  left  vacant  round  the  axis; 
that  is,  the  central  line  is  tubular.  The  fire-workers  call  this  space  the  soul  of  the  rocket 
{ame  de  la  fusee).  On  account  of  its  somewhat  conical  form,  hollow  rods,  adjustable  to 
different  sizes  of  broaches  or  skewers,  are  required  in  packing  the  charge  ;  which  must 
be  done  while  the  cartridge  is  sustained  by  its  outside  mould,  or  copper  cylinder.  The 
composition  of  sky-rockets  is  as  follows  (see  next  page). 

The  cartridge  being  charged  as  above  described,  the  pot  must  be  adjusted  to  it,  with 
the  garniture ;  that  is,  the  serpents^  the  crackers,  the  stars,  the  showers  of  fire,  Ac. 
The  pot  is  a  tub  of  pasteboard  wider  than  the  body  of  the  rocket,  and  about  one-third 
of  its  length.  After  being  strangled  at  the  bottom  like  the  mouth  of  a  phial,  it  is  at- 
tached to  the  end  of  a  fusee  by  means  of  twine  and  paste.  These  are  afterward  covered 
with  paper.  The  garniture  is  introduced  by  the  neck,  and  a  paper  plug  is  laid  over  it 
The  whole  is  enclosed  within  a  tube  of  pasteboard  terminating  in  a  cone,  which  is  firmly 
pasted  to  the  pot  The  quick-match  is  now  finally  inserted  into  the  soul  of  the  rocket 
The  rod  attached  to  the  end  of  the  sky-rockets  to  direct  their  flight  is  made  of  willow 
or  any  other  light  wood.  M.  Ruggieri  replaced  the  rod  by  conical  wings  containing 
explosive  materials,  and  thereby  made  them  fly  further  and  straighter. 

The  garnitures  of  the  sky-rocket  pots  are  the  following: — 

1.  Stars  are  small,  round,  or  cubic  solids,  made  with  one  of  the  following  compo- 


I1 


■l 


I  il 


730 


FISH-HOOKS. 


When  the  bore  is 

1  of  an  inch ; 

1  to  174 ; 

U; 

Nitre     - 

16 

16 

16 

Charcoal 

7 

8 

9 

Sulphur 

4 

4 

4 

Brilliant  Fire. 

Nitre     - 

16 

16 

16 

Charcoal 

6 

7 

8 

Sulphur 

4 

4 

4 

Fine  steel  filings 

3 

4 

6 

Chinese  Fire. 

Nitre     - 

16 

16 

16 

Charcoal 

4 

5 

6 

Sulphur 

3 

3 

4 

Fine  borings  of  cast-iron 

3  coarser 

4  mixed 

5 

sitions,  and  soaked  in  spirits.     White  atars,  nitre,  16 ;  sulphur,  8 ;  gunpowder,  3.  Others 
more  vivid  consist  of  nitre,  16;  sulphur,  7;  gunpowder   4. 

Stars  for  golden  showers,  nitre,  16;  sulphur,  10;  charcoal,  4;  gunpowder,  16;  lamp- 
black, 2.  Others  yellower  are  made  with  nitre,  16;  sulphur,  8;  charcoal,  2;  lampblack, 
2 ;  gunpowder,  8. 

The  serpe-nts  are  small  fusees  made  with  one  or  two  playing  cards ;  their  bore  being 
less  than  half  an  inch.  The  lardons  are  a  little  larger,  and  have  three  cards ;  the  ve* 
tilles  are  smaller.  Their  composition  is,  nitre,  16 ;  charcoal,  not  too  fine,  2 ;  gunpowder, 
4;  sulphur,  4  ;  fine  steel  filings,  6. 

The  petards  are  cartridges  filled  with  gunpowder  and  strangled. 

The  saaxms  are  cartridges  clayed  at  each  end,  charged  with  the  brilliant  turning  fire, 
and  perforated  with  one  or  two  holes  at  the  extremity  of  the  same  diameter. 

The  cracker  is  a  round  or  square  box  of  pasteboard,  filled  with  granulated  gunpowder, 
and  hooped  all  round  with  twine. 

Roman  candles  are  fusees  which  throw  out  very  bright  stars  in  succession.  With  the 
composition  (as  under)  imbued  with  spirits  and  gum-water,  small  cylindric  masses  are 
made,  pierced  with  a  hole  in  their  centre.  These  bodies,  when  kindled  and  projected 
into  the  air,  form  the  stars.  There  is  first  put  into  the  cartridge  a  charge  of  fine  »un' 
powder  of  the  size  of  the  star ;  above  this  charge  a  star  is  placed ;  then  a  charge  of 
composition  for  the  Roman  candles. 

The  stars,  when  less  than  |  of  an  inch,  consist  of  nitre,  16;  sulphur,  7;  gunpowder,  0. 
When  larger,  of  nitre,  16 ;  sulphur,  8 ;  gunpowder,  8. 

Roman  candles,  nitre,  16 ;  charcoal,  6 ;  sulphur,  3.  When  above  f  of  an  inch,  nitre, 
16;  charcoal,  8;  sulphur,  6. 

The  girandes,  or  bouquets,  are  those  beautiful  pieces  which  usually  conclude  a  fire- 
work exhibition ;  when  a  multitude  of  jets  seem  to  emblazon  the  sky  in  every  direction, 
and  then  fall  in  golden  showers.  This  eflfect  is  produced  by  distributing  a  number  of 
eases  open  at  top,  each  containing  140  sky-rockets,  communicating  with  one  another 
by  quick-match  strings  planted  among  them.  The  several  cases  communicate  with  each 
other  by  conduits,  whereby  they  take  fire  simultaneously,  and  produce  a  volcanic  display. 

The  water  fire-works  are  prepared  like  the  rest ;  but  they  must  be  floated  either  by 
woode.1  bowls,  or  by  discs  and  hollow  cartridges  fitted  to  them. 

Blue  fire  for  lances  may  be  made  with  nitre,  16  ;  antimony,  8 ;  very  fine  zinc  filings,  4. 
Chinese  paste  fur  the  stars  of  Roman  candles,  bombs,  &c. :— Sulphur,  16;  nitre,  4; 
gunpowder  meal,  12 ;  camphor,  1 ;  linseed  oil,  1  j  the  mixture  being  moistened  with 
spirits. 

The  feu  gregois  of  Ruggieri,  the  son :— Nitre,  4;  sulphur,  2;  naptha,  1.     See  Pyro- 

TECHNY  and  ROCKKTS. 

The  red  fire  composition  is  made  by  mixing  40  parts  of  nitrate  of  strontia,  13  of  flowen 
of  sulphur,  5  of  chlorate  of  potash,  and  4  of  sulphuret  of  antimony. 

While  fire  is  produced  by  igniting  a  mixture  of  48  parts  nitre;  13 J  sulphur;  7J  sul- 
phuret of  antimony;  or,  24  nitre,  7  sulphur,  2  realgar;  or,  75  nitre,  24  sulphur,  1  cA&r- 
coal;  or,  finally,  100  of  gunpowder  meal,  and  25  of  cast-iron  fine  borincs. 

The  blue  fire  composition  is  4  parts  of  gunpowder  meal;  2  of  nitre;  sulphur  and 
zinc,  each  3  parts. 

FISH-HOOKS  (Hamecons,  Fr. ;  Fishangeln,  Germ.)  are  constructed  with  simple 
tools,  but  require  great  manual  dexterity  in  the  workmen.    The  iron  wire  of  which  they 


t 


FLANNEL. 


731 


they  are  made  should  be  of  the  best  quality,  smooth  and  sound.  A  bundle  of  such 
wire  is  cut  in  lengths,  either  by  shears  or  by  laying  it  down  upon  an  angular  wedge  of 
hard  steel  fixed  horizontally  in  a  block  or  anvil,  and  striking  off  the  proper  lengths  by 
the  blows  of  a  hammer.  In  fashioning  the  barbs  of  the  hooks,  the  straight  piece  of  wire 
18  laid  down  in  the  groove  of  an  iron  block  made  on  purpose,  and  is  dexterously  struck 
by  the  chisel  in  a  slanting  direction,  across  so  much  of  the  wire  as  may  be  deemed 
necessary.  A  sharp-pointed  little  wedge  is  thus  formed,  whose  base  graduates  into  the 
substance  of  the  metal. 

The  end  of  the  wire  where  the  line  is  to  be  attached  is  now  flattened  or  screw-tapped ; 
the  other  end  is  sharp  pointed,  and  the  proper  twisted  curvature  is  given.  The  soft  iron 
hooks  are  next  case-hardened,  to  give  them  the  steely  stiff'ness  and  elasticity,  by  imbed- 
ding them  in  animal  charcoal  contained  in  an  earthen  or  iron  box ;  see  Case-Hard- 
ENiNG ;  after  which  they  are  brightened  by  heating  and  agitating  them  with  bran,  and 
finally  tempered  by  exposure  to  a  regulated  temperature  upon  a  hot  iron  plate.  Hooks 
for  salt-water  fishing  are  frequently  tinned,  to  prevent  them  wearing  rapidly  away  in 
rust.     See'Tm  Plate. 

FLAKE  WHITE  is  the  name  sometimes  given  to  pure  white-lead. 

FLAME  {Flamme,  Fr.  and  Germ.)  is  the  combustion  of  an  explosive  mixture  of  an 
inflammable  gas  or  vapor  with  air.  That  it  is  not,  as  many  suppose,  combustion  merely 
at  the  exterior  surface,  is  proved  by  plunging  a  fragment  of  burning  phosphorus  or  sul- 
phur into  the  centre  of  a  large  flame  of  alcohol.  Either  of  these  bodies  will  continue  to 
burn  there  with  its  peculiar  light ;  thus  proving  that  oxygen  is  mixed  with  the  whole  of 
the  burning  vapor.  If  we  mix  good  coal  gas  with  as  much  atmospheric  air  as  can  con- 
vert all  its  carbon  into  carbonic  acid,  the  mixture  will  explode  with  a  feeble  blue  li?ht; 
but  if  we  mix  the  same  gas  with  a  small  quantity  of  air,  it  will  burn  with  a  rich  white 
flame.  In  the  latter  case  the  carbonaceous  particles  are  precipitated,  as  Sir  H.  Davy 
first  showed,  in  the  interior  of  the  flame,  become  incandescent,  and  constitute  white 
light :  for  from  the  ignition  of  solid  matter  alone  can  the  prismatic  rays  be  emitted  in 
that  concentrated  union.  Towards  the  interior  of  the  flame  of  a  candle,  a  lamp,  or  a  gas 
jet,  where  the  air  is  scanty,  there  is  a  deposition  of  solid  charcoal,  which  first  by  its  igni- 
tion, and  afterwards  by  its  combustion,  increases  in  a  high  degree  the  intensity  of  the 
light.  If  we  hold  a  piece  of  fine  wire  gauze  over  a  jet  of  coal  jjas  close  to  the  orifice, 
and  if  we  then  kindle  the  gas,  it  will  burn  above  the  wire  with  its  natural  brilliancy; 
but  if  we  elevate  the  gauze  progressively  higher,  so  as  to  mix  more  and  more  air  with  it 
before  it  reaches  the  burning  point,  its  flame  will  become  fainter  and  less  white.  At  a 
certain  distance  it  becomes  blue,  like  that  of  the  above  explosive  mixture.  Since  the 
combustion  of  all  the  constituents  is  in  this  case  direct  and  complete,  the  heat  becomes 
greatest  in  proportion  nearly  as  the  light  is  diminished.  If  a  few  platina  wires  be  held 
in  that  dim  flame  they  will  grow  instantly  white  hot,  and  illuminate  the  apartment.  On 
reversing  the  order  of  this  experiment,  by  lowering  progressively  a  flat  piece  of  wire 
gauze  from  the  summit  towards  the  base  of  a  gas  flame,  we  shall  find  no  charcoal  depos- 
ited at  its  top,  because  plenty  of  air  has  been  introduced  there  to  convert  all  the  carbon 
of  the  gas  into  carbonic  acid,  and  therefore  the  apex  is  blue ;  but  as  we  descend,  more 
and  more  charcoal  will  appear  upon  the  meshes.  At  the  very  bottom,  indeed,  where  the 
atmospheric  air  impinges  upon  the  gauze,  the  flame  is  again  blue,  and  no  charcoal  can 
therefore  be  deposited. 

The  fact  of  the  increase  of  the  brilliancy  and  whiteness  of  flame  by  the  developmen 
and  ignition  of  solid  matter  in  its  bosom  illustrates  many  curious  phenomena.  We  can 
thus  explain  why  defiant  gas  affords  the  most  vivid  illumination  of  all  the  gases ;  because, 
being  surcharged  with  charcoal,  its  hydrogen  lets  it  go  in  the  middle  of  the  flame,  as  if 
does  in  an  ignited  porcelain  tube,  whereby  its  solid  particles  first  get  ignited  to  white- 
ness, and  then  burn  away.  AVhen  phosphorus  is  inflamed  it  always  yields  a  pure  white 
light,  from  the  ignition  of  the  solid  particles  of  the  snowy  acid  thus  produced. 

In  the  blowpipe  the  inner  blue  flame  has  the  greatest  heal,  because  there  the  combus- 
tion of  the  whole  fatty  vapor  is  complete.  The  feeble  light  of  burning  hydrogen,  car- 
bonic oxyde,  and  sulphur,  may,  upon  the  principles  now  expounded,  be  increased  by 
simply  placing  in  them  a  few  particles  of  oxyde  of  zinc,  slender  filamants  of  amianthus,  or 
fine  platina  wire.  Upwards  of  twenty  years  ago  I  demonstrated,  in  my  public  lectures 
in  Glasgow,  that  by  narrowing  the  top  of  a  long  glass  chimney  over  an  argand  flame 
either  from  oil  or  coal  gas,  the  light  could  be  doubled  at  the  same  cost  of  material.  The 
very  tall  chimneys  used  by  the  Parisian  lampists  are  very  wasteful.  I  find  that  with  a 
narrow  chimney  of  half  the  length  of  theirs,  I  can  have  as  good  a  light,  and  save  30  per 
cent,  of  the  oil.  Thus  the  light  of  a  flame  may  be  increased  by  diminishing  its  heat,  or 
the  intensity  of  its  combustion;  and  conversely  the  heat  of  a  flame  may  be  increased  by 
diminishing  its  light. 

FLANNEL ;  a  plain  woollen  stuflT,  of  a  rather  open  and  slight  fabric. 


h^ 


732 


FLAX. 


FLAX.  The  general  appellation  of  the  fibrons  produce  used  in  the  manufacture  of 
linen  threads,  <fec,  of  the  plant  Linum  usitatissimum,  which  is  cultivated,  not  for  this 
produce  only,  but  for  that  of  its  seed,  employed  in  agriculture  for  feeding  and  fatten- 
ing cattle,  as  well  as  in  commerce  for  making  the  oil  so  well  known  as  "  linseed 
oil." 

This  plant  grows  to  the  height  of  2  or  3  feet,  having  a  round  and  hollow  stem,  which 
divides  into  several  branches,  bearing  blue  flowers;  these  become  the  seed-pods  of  10 
cells,  each  of  which  contains  one  seed.  As  varieties,  we  distinguish  the  "spring"  flax 
with  short  knotty  stems,  whose  seed  capsules  at  the  period  of  maturity  open  with  a 
perceptible  sound;  and  the  "close"  flax,  with  longer,  smoother  stems,  whose  capsules 
give  out  the  seed  only  when  thrashed  ;  the  latter  variety  is  the  one  most  generally  cul- 
tivated. Owing  to  the  many  improveraenta  recently  made  in  the  various  processes  of 
the  flax  manufacture,  all  the  operations  for  converting  the  raw  plant  to  its  ultimate 
useful  and  ornamental  state  have  been  greatly  simplified  and  facilitated,  and  much  at- 
tention has  been  paid  to  improving  its  cultivation,  which  has  necessarily  produced 
many  changes  in  the  formerly  established  modes  of  husbandry. 

Flax  may  be  grown  upon  a  great  vai-iety  of  soils:  the  best  is  a  sound,  dry,  deep  loam, 
with  a  clay  subsoil ;  this  should  be  properly  drained,  as  too  much  underground  or  surface 
water  is  alike  injurious.  It  is  necessary  that  the  land  should  be  brought  to  an  ex- 
ceedingly fine  state  by  frequent  ploughings  and  harrowings,  commenced  in  the  autumn 
previous  to  the  sowing,  which  should  take  place  toward  the  end  of  March,  or  be- 
ginning of  April  From  2  to  2^  bushels  of  seed  are  required  for  one  acre:  the 
seed  selected  should  be  of  a  bright  brown  color,  heavy,  shining,  and  of  an  oily  feel, 
avoiding  such  as  have  hard  end&  Riga  is  the  best  for  the  greatest  variety  of  soils, 
though  Dutch  is  frequently  used  with  great  success.  American  does  not  generally  suit, 
as  it  is  apt  to  produce  a  coarse,  branchy  stem.  The  manner  of  sowing  should  be  varied 
according  to  the  purpose  for  which  the  crop  is  intended.  When  grain  is  the  object  of 
the  grower,  the  sowing  should  be  thin,  as  the  plants  then  put  out  more  branches,  and 
thus  yield  more  seed,  but  the  fibrous  produce  becomes  soft  and  meagre  ;  the  contrary 
is  the  case  when  the  sowing  is  thick.  Being  one  of  the  most  tender  plants  of  field  cul- 
tivation, it  requires  very  peculiar  care  in  weeding,  so  as  not  to  be  injured  by  either  the 
neglect  or  excess  of  this  work,  which  should  be  done  when  the  plants  are  about  3 
inches  high,  that  is,  about  a  month  after  sowing.  Guano  and  bone  dust  are  suitable 
manures  if  farm  dung  is  scarce.  The  following  artificial  manure,  it  has  been  said,  will 
replace  chemically  the  constituents  of  the  plants  produced  from  an  acre  of  land,  viz: 

Muriate  of  potash  -  ...  39  lbs.  ? 

Common  salt       -----  28  lbs. 

Burned  gypsum,  powdered         -  -  •         -  34  lbs. 

Bone  dust  -----  54  lbs. 

Sulphate  magnesia  -  -  -  -  66  lbs. 

The  average  produce  of  seed  is  12  bushels  to  the  acre. 

In  regard  to  flax  being  considered  a  wasting  crop  for  the  land  there  are  some  ob- 
servations to  be  made  that  may  controvert  that  idea  and  establish  one  more  sound  in 
its  place. 

Assuming  that  the  ashes  of  plants  left  after  they  are  consumed  by  fire  form  a 
criterion  of  the  quantity  of  nutritive  matter  they  have  extracted  from  the  soil,  there 
may  at  first  sight  appear  much  truth  in  the  prevailing  opinion  as  to  the  exhaust- 
ing nature  of  the  flax  crop,  since  the  a«hes  of  this  plant  are  6-0  of  the  whole,  which 
is  a  large  proportion.  But  as  no  ashes  result  from  burning  the  pure  fibre,  which 
is  solely  the  part  that  may  not  be  reconsumed  upon  the  land,  it  proves  that  the 
fertility  of  the  soil  is  not  injured  by  that  production.  The  nutrition  withdrawn 
by  the  other  parts  can  be  as  easily  replaced  by  this  plant  as  by  any  other,  9_ths  by 
the  water  alone  in  which  the  steeping  is  to  be  afterward  carried  on,  and  which  should 
therefore  be  kept  and  employed  as  a  liquid  manure,  to  which  must  be  added  that 
more  solid  resulting  from  feeding  cattle  on  the  seed  or  oil  cake,  and  from  the  ashes 
of  the  chafl^  and  thus  a  far  greater  part  of  the  constituent  of  this  plant  is  returned 
than  of  almost  any  other.  Though  the  color  of  the  flax  is  rather  improved  by  letting 
the  water  run  in  a  small  stream  through  the  steeping-pond  during  the  operation  yet 
perhaps  it  may  be  a  greater  object  to  retain  it  for  manure  than  to  waste  it  for  that  pur- 
pose. '^ 

Whenever  the  flax  is  ripe,  which  is  shown  by  the  bottom  of  the  stalk  becoming  yel- 
low, and  the  leaves  beginning  to  drop  off,  it  must  be  immediately  reaped  by  pulling  it 
up  by  the  roots.  The  seeds  are  still  immature,  fit  merely  for  the  oil  press,  and  not  for 
sowing.  When  the  seed  crop  is  the  object,  the  plant  must  be  suffered  to  acquire  its 
full  maturity;  in  which  ease  the  fibres  are  less  fine  and  soft 

The  flax  is  carried  oflf  the  field  in  bundles  to  be  rippled,  or  stripped  of  its  seeds,  which 


FLAX. 


733 


is  done  by  drawing  it  by  handfuls,  through  an  iron  comb  with  teeth  eight  inches  long, 
fixed  upright  in  a  horizontal  beam.  When  the  seeds  are  more  fully  ripened,  they  may 
be  separated  by  the  thrashing  mill. 

The  operations  next  performed  upon  the  flax  will  be  understood  by  attending  to  the  struc- 
ture of  the  stem.  In  it  two  principal  parts  are  to  be  distinguished ;  the  woody  heart  or 
boon  and  the  harl  (covered  outwardly  with  a  fine  cuticle),  which  encloses  the  former 
like  a  tube  consisting  of  parallel  lines.  In  the  natural  state,  the  fibres  of  the  harl  are 
attached  firmly,  not  only  to  the  boon,  but  to  each  other,  by  means  of  a  green  or  yellowish 
substance.  The  rough  stems  of  the  flax,  after  being  stripped  of  their  seeds,  lose  in  mois- 
ture by  drying  in  warm  air,  from  55  to  65  per  cent,  of  their  weight ;  but  somewhat  less 
when  they  are^quite  ripe  and  woody.  In  this  dry  stale  they  consist  in  100  parts  of  from 
20  to  23  per  cent,  of  harl,  and  from  80  to  77  per  cent,  of  boon.  The  latter  is  composed 
upon  the  average  of  69  per  cent,  of  a  peculiar  woody  substance,  12  per  cent,  of  a  matter 
soluble  in  water,  and  19  per  cent,  of  a  body  not  soluble  in  water,  but  in  alkaline  leys. 
The  harl  contains  at  a  mean  58  per  cent,  of  pure  flaxen  fibres,  25  parts  soluble  in  water 
(apparently  extractive  and  albumen),  and  17  parts  insoluble  in  water,  being  chiefly 
gluten.  By  treating  the  harl  with  either  cold  or  hot  water,  the  latter  substance  is  dyed 
brown  by  the  soluble  matter,  while  the  fibres  retain  their  coherence  to  one  another 
Alkaline  leys,  and  also,  though  less  readily,  soap  water,  dissolve  the  gluten,  which  seems 
to  be  the  cement  of  the  textile  fibres,  and  thus  set  them  free. 

The  cohesion  of  the  fibres  in  the  rough  harl  is  so  considerable  that  by  mechanical 
means,  as  by  beatine,  rubbing,  &c.,  a  complete  separation  of  them  cannot  be  effected, 
unless  with  great  loss  of  time  and  rupture  of  the  filaments.  This  circumstanc* 
thews  the  necessity  of  having  recourse  to  some  chemical  method  of  decomposing  the 
gluten.  The  process  employ^  with  this  view  is  a  species  of  fermentation,  to  which  the 
flax  stalks  are  exposed ;  it  is  called  retting,  a  corruption  of  rotting,  since  a  certain  degree 
of  putrefaction  takes  place.  The  German  term  is  rusting.  This  is  the  first  important 
step  in  the  preparation  of  flax.  After  the  retting  is  completed,  the  boon  of  the  stalks 
must  be  removed  by  the  second  operation  called  breaking,  and  other  subordinate  process- 
es. The  harl  freed  from  the  woody  parts  contains  still  a  multitude  of  fibres,  more  or  less 
coherent,  or  entangled,  and  of  variable  lengths,  so  as  to  be  ill  adapted  for  spinning.  These 
are  removed  by  the  heckle,  which  separates  the  connected  fibres  into  their  finest  filaments, 
removes  those  that  are  too  short,  and  disentangles  the  longer  ones. 

I.  0/ retting. — The  fermentation  of  this  process  may  be  either  rendered  rapid  by  steep- 
ing the  flax  in  water,  or  slow  by  using  merely  the  ordinary  influence  of  the  atmospheric 
damp,  dews,  and  rain.  Hence  the  distinction  of  water-retting  and  dew-retting.  Both 
may  also  be  combined. 

Prior  to  being  retted,  the  flax  should  be  sorted  according  to  the  length  and  thickness  of 
its  stalks,  and  its  state  of  maturity  :  the  riper  the  plant,  the  longer  must  the  retting  last. 
The  due  length  of  the  process  is  a  point  too  little  studied. 

Waier-retting. — When  flax  stalks  are  macerated  in  water,  at  a  temperature  not  too 
low,  fermentation  soon  begins,  evinced  in  the  dingy  infusion,  by  disengagement  of 
carbonic  acid  gas,  and  the  production  of  vinegar.  If  the  flax  be  taken  out  at  the  end  of 
a  few  days,  dried,  and  rubbed,  the  textile  filaments  are  found  to  be  easily  separable  from 
each  other.  By  longer  continuance  of  the  steep,  the  water  ceases  to  be  acid,  it  becomes 
to  a  certain  degree  alkaline,  from  the  production  of  ammonia,  diffuses  a  fetid  odor,  from 
the  disengagement  of  sulphureted  hydrogen  gas,  along  with  the  carbonic  acid;  the  acetous 
fermentation  being  in  fact  now  changed  into  the  putrid.  The  filaments  become  yellowish 
brown,  afterwards  dark  brown,  and  lose  much  of  their  tenacity,  if  the  process  be  carried 
further. 

When  the  operation  is  conducted  with  discernment,  the  water-retting  may  be  completed 
by  the  acetous  fermentation  alone,  as  the  putrefaction  should  never  be  suffered  to  proceed 
to  any  length ;  because  when  over-retted,  flax  is  partially  rotten,  gets  a  bad  color,  and 
yields  a  large  proportion  of  tow. 

For  water-retting,  the  flax  must  be  bound  up  in  sheaves,  placed  in  layers  over  each 
other  in  the  water,  or  sometimes  upright,  with  the  roots  undermost.  Straw  may  be  put 
below  to  keep  it  from  touching  the  ground,  and  boards  may  be  laid  upon  the  top,  with 
weights  to  hold  it  immersed  about  a  foot  beneath  the  surface,  especially  when  the  fer- 
mentative gases  make  it  buoyant.  As  soon  as  it  sinks  at  the  end  of  the  fermentation,  it 
must  be  inspected  at  least  twice  a  day,  and  samples  must  be  taken  out  to  see  that  no 
over-retting  ensues.  A  single  day  too  long  often  injures  the  flax  not  a  little.  We  may 
judge  that  the  retting  is  sufficient  when  the  harl  separates  easily  from  the  boon  by  the 
fingers,  when  the  boon  breaks  across  without  bending,  and  when  several  stalks  knotted 
together  sink  to  the  bottom  upon  being  thrown  into  the  water.    For  this  completion,  a 


11 


'i   t 


I 


734 


FLAX. 


Bhorter  or  longer  time  is  required  according  to  the  quality  of  the  flax,  the  temperature, 
Ac,  so  that  the  term  may  vary  from  five  to  fourteen  days.  It  may  be  done  either  in 
running  or  in  stagnant  water.  For  the  latter  purpose,  tanks  five  feet  deep  are  dug  in  the 
ground.  In  stagnant  water,  the  process  is  sooner  finished,  but  it  is  more  hazardous  and 
gives  a  deeper  stain  to  the  fibres,  than  in  a  stream,  which  carries  off"  much  of  the  color. 
Tlie  best  place  for  steeping  flax  is  a  pond  with  springs  of  water  at  its  bottom;  or  a 
tank  into  which  a  rivulet  of  water  can  be  occasionally  admitted,  while  the  foul  water 
IS  let  off.  For  every  fresh  quantity  of  flax,  the  pond  should  be  emptied,  and  supplied 
with  clear  water.  Water  impregnated  with  iron  stains  flax  a  permanent  color,  and 
should  therefore  never  be  used.  After  retting,  the  flax  should  be  taken  out  without 
delay,  rinsed  in  clean  water,  and  exposed  in  an  airy  situation  to  dry  by  the  sun. 

Rough  rippled  flax  stalks,  well  seasoned  before  being  retted,  and  dried  afterward, 
show  a  loss  of  weight,  amounting  to  20  or  30  per  cent,  affecting  both  the  boon  and  the 
harl.  This  loss  is  greater  the  finer  the  stems,  and  the  longer  the  retting.  The  harl 
contains,  besides  the  textile  filaments,  a  certain  portion  of  a  glutinous  cement;  but 
nothing  soluble  in  water.  The  destruction  of  the  gluten  can  not  be  pushed  to  the  last 
point  by  steeping,  without  doing  an  essential  injury  to  the  filaments. 

JJew-retting.— The  fetid  and  noxious  exhalations  which  the  water-retting  diffuses 
oyer  an  extensive  district  of  country,  and  the  danger  of  over-retting  in  that  way,  espe- 
cially with  stagnant  water,  are  far  from  recommending  that  process  to  general  adop- 
tion. Dew-retting  accomplishes  the  same  purpose,  by  the  agency  of  the  air,  dews,  and 
'k'"'iIiV  '""^^  "^*^*'^  convenient,  though  far  slower  manner.  The  flax,  with  this  view, 
should  be  spread  out  thin  upon  meadow  or  grass  lands,  but  never  upon  the  bare  ground, 
and  turned  over,  from  time  to  time,  till  the  stems,  on  being  rubbed  between  the  fingers, 
show  that  the  harl  and  the  boon  are  ready  to  part.  The  duration  of  dew-retting  is, 
of  course,  very  various,  from  two  to  six  or  eight  weeks,  as  it  depends  upon  the  state  . 
of  the  w«ather;  a  moist  air  being  favorable,  and  dry  sunshine  the  reverse.  The  loss 
of  weight  by  dew-retting  is  somewhat  less  than  by  water-retting;  and  the  textile  fibres 
are  of  a  brigliter  color,  softer  and  more  delicate  to  the  touch. 

Mixed  rettinf;.— This  may  be  fairly  regarded  as  the  preferable  plan,  the  retting  being 
begun  in  the  water  and  finished  in  the  air.  The  flax  should  be  taken  out  of  the  steep 
whenever  the  acetous  fermentation  is  complete,  before  the  putrid  begins,  and  exposed 
for  two  or  three  weeks,  on  the  grass. 

Within  the  last  two  years,  the  hazardous  and  tedious  process  above  described  ha« 
been  attempted  to  be  superseded  by  steeping  the  flax  plant  in  vats  of  water  artificially 
heated  to  70°  Fjihr.,  whereby  the  effects  are  produced  in  sixty  or  seventy  hours.  Drying 
by  fire  in  kilns  is  pernicious  alike  to  the  seed  or  fibrous  produce;  as  in  the  former  it 
dries  up  too  soon  the  nutritious  particles  that  would  be  absorbed  by  the  seed  from  its 
pod  or  outer  covering,  and  in  the  latter  impairs  the  rich  and  oily  property  of  the  flax. 
The  following  is  a  description  of  an  establishment  for  the  prosecution  of  Mr.  Schenck's 
process,  situated  at  Newport  river,  county  Mayo.  The  tenements  containing  the  vats 
and  drying  shelves  are  simple  wooden  sheds  of  cheap  construction.  In  one  end  of  the 
building  are  four  vats  set  parallel  to  each  other  the  length  of  the  house;  they  are  made 
of  inch  deal  in  the  form  of  a  parallelogram,  fifty  feet  long,  six  broad,  and  four  deep. 
There  are  false  bottoms  perforated  with  holes;  underneath  these  are  introduced  the 
steam-pipes,  crossing  the  vats,  and  having  stop-cocks  at  their  entrance,  by  which  the 
steam  can  be  let  on  from  the  main  pipe  as  required.  The  steam  is  generated  in  a  small 
boiler,  which  also  serves  to  turn  two  hydro-€xtractor\  a  patent  apparatus  used  to  drive 
off  a  portion  of  the  water  with  which  the  flax  is  saturated,  on  being  taken  from  the 
vat&  The  flax  is  packed  into  the  empty  vats,  on  the  butt  ends,  in  a  half  sloping 
position,  precisely  as  in  the  case  of  a  steep  pool,  only  one  layer  being  the  depth.  The 
water  is  then  let  in,  and  a  frame  fastened  over  the  top  of  the  flax,  answering  the  end 
of  stones  and  straw  or  soda  in  the  steeping  pools,  for  prevention  of  the  rising  of  the 
flax  in  course  of  fermentation.     This  process  is  now  renounced. 

The  steam  is  then  let  into  the  pipes  liy  turning  the  stopcocks,  and  the  water  is  some 
eighteen  or  twenty  hours  in  becoming  heated  to  the  required  point,  85°  or  90".  The 
ferrnentation  then  commences,  and  no  further  steam  is  required,  the  action  going  on 
until  the  flax  is  thoroughly  retted,  which  is  in  forty  hours  afterward,  being  sixty  from 
the  time  of  the  admission  of  the  water.  At  the  end  of  the  sixty  hours,  the  flax  is  taken 
out  the  water  allowed  to  run  off,  and  the  vat  permitted  to  cool.  The  same  process  is 
then  repeated  with  fresh  water  and  fresh  flax.  When  taken  from  the  water,  the  flax 
IS  packed  in  the  hydro-extractor,  which  is  a  round  vessel  of  iron  made  to  revolve  by 
steam  power  with  great  velocity,  the  water  being  driven  out  of  the  flax  on  the  principle 
of  the  centrifugal  force.  Thirty  beefs  or  small  handfuls  are  placed  in  this  machine  at 
a  time,  and  about  20  lbs.  of  water  are  extracted  in  from  three  to  five  minutes.  A  few- 
hours  suflSce  for  the  contents  of  a  vat  each  vat  containing  2  tons  of  flax  straw.  The 
hydro-extractor  only  separates  a  portion  of  the  water;  the  flax  now  remains  to  be 


}i 


\ 


FLAX. 


735 


thoroughly  dried.  In  summer,  or  indeed,  for  six  months  in  the  year,  this  can  be 
accomplished,  as  usual,  by  spreading  upon  grass  land  in  the  open  air.  During  winter, 
however,  it  is  necessary  to  procure  other  means  of  drying.  A  shed  has  therefore  been 
erected,  communicating  by  doors  with  the  vat  house,  filled  with  ranges  of  shelves,  com- 
posed simply  of  railings  of  lathwood  in  five  or  six  tiers.  The  flax  is  spread  lightly 
along  these  shelves  by  women,  and  the  house  is  heated  by  steam-pipes.  This  house  is 
capable  of  drying  the  full  of  one  vat  per  diem.  The  flax,  when  dried,  is  made  up  in 
beets  or  handfuls,  of  a  size  suited  for  feeding  into  the  breaking  rollers  of  the  mill. 

2.  The  breaking  is  performed  by  an  instrument  called  a  brake.  In  order  to  give  the 
wood  or  boon  such  a  degree  of  brittleness  as  to  make  it  part  readily  from  the  harl, 
whereby  the  execution  of  this  process  is  rendered  easy,  the  flax  should  be  well  dried  in 
the  sun,  of  what  is  more  suitable  to  the  late  period  of  the  year,  in  a  stove.  Such  is 
often  attached  to  the  bakers' ovens  in  Germany,  and  other  flax-growing  countries.  The 
drying  temperature  should  never  exceed  120°  F.,  for  a  higher  heat  makes  it  brittle, 
easy  to  tear,  and  apt  to  run  into  tow.  Before  subjecting  the  flax  to  the  brake,  the 
stems  should  be  equalized  and  laid  parallel  by  the  hand,  and  the  entangled  portions 
should  be  straightened  with  a  coarse  heckle.  The  brake  has  one  general  construction, 
and  consists  of  two  principal  parts,  the  frame  or  case,  and  the  sword  or  beater.  In  the 
simplest  brakes,  the  frame  e^jfig.  566,  is  a  piece  of  wood  cleft  lengthwise  in  the  middle, 
supported  by  the  legs  a  and  c.  The  sword/,  also  of  hard  wood,  is  formed  with  an  edge 
beneath,  and  turns  round  the  centre  of  motion  at  q,  when  seized  by  the  handle  A,  and 
moved  up  and  down.  As  it  descends,  the  sword  enters  the  cleft  of  the  frame,  and  breaks 
the  flax  stalks  laid  transversely  upon  it,  scattering  the  boon  in  fragments. 


/    f      \ 


B 

f¥ 

\A 

'  N 

A 

A  s 

i  i 

U 

ta  %m 

567 


But  those  hand  brakes  are  more  convenient  which  are  provided  with  a  double  cleft, 
or  triple  row  of  oblong  teeth,  with  a  double  sword.  This  construction  will  be  under- 
stood by  inspecting  figs.  566,  567,  568.  Fig.  566  is  the  section  of  that  side  at  which 
the  operative  6\\&;  fig.  567  is  a  section  in  the  line  a  b,  oi  fig.  566;  and  fig.  568,  the 
ground  plan.  The  whole  machine  is  made  of  hard  wood,  commonly  red  beech.  Two 
planks,  a  and  <•,  form  the  legs  of  the  implement  a  is  mortised  in  a  heavy  block,  to  give 
the  brake  a  solid  bearing;  two  stretchers  d  bind  a  and  c  firmly  together.  The  frame  « 
consists  of  three  thin  boards,  which  are  placed  edgewise,  and  have  their  ends  secured  in 
a  and  c.  The  sword  /  is  a  piece  of  wood,  so  chamfered  from  i  to  k,  that  it  appears 
forklike,  and  embraces  the  middle  piece  of  the  frame ;  its  centre  of  motion  is  the  wooden 
pin  q;  in  front  is  the  handle  /<,  which  the  operative  seizes  with  the  right  hand.  Both 
the  lathes  of  the  frame  and  those  of  the  sword  are  sharpened,  from  I  to  the  front  end,  as 
is  best  shown  in  fig.  567 ;  but  the  edges  must  not  be  too  sharp,  for  fear  of  injuring  the 
flax;  and,  for  the  same  reason,  the  sword  should  not  sink  too  far  between  the  lathes  of 
the  frame.  Such  hand-brakes  are  laborious  in  use,  and  often  tear  the  harl  into  tow. 
The  operative,  usually  a  female,  in  working  the  brake,  seizes  with  her  left  hand  a  bundle 
of  flax,  lays  it  transverely  across  the  frame,  and  strikes  it  smartly  with  repeated  blows 
of  the  sword,  pushing  forward  continually  new  portions  of  the  flax  into  the  machine. 
She  begins  with  the  roots,  turns  next  round  the  tips,  then  goes  on  through  the  length 
of  the  stalks.  Flax  is  frequently  exposed  twice  to  the  brake,  with  a  stove-drying 
between  the  two  applications. 

The  brake  machines  afford  a  far  preferable  means  of  cleaning  flax  than  the  above 
hand  tools.  The  essential  part  of  such  a  machine  consists  in  several  deeply  fluted 
rollers  of  wood  or  iron,  whose  teeth  work  into  each  other,  and  while  they  stretch  out 
the  flaxen  stalks  between  them,  they  break  the  wood  or  boon,  without  doing  that  violence 

47 


7a6 


FLAX. 


FLAX 


737 


to  the  harl  which  hand  mechanisms  are  apt  to  do.     The  following  may  be  regarded  aa 
one  of  the  b^st  constructions  hitherto  contrived  for  breaking  flax.     Mg.  569  is  a  view 
of  the  right  side  of  this  machine.    Mg.  570,  Uie  view  from  behind,  where  the  broken 
570  569 


is 


I 


flax  issues  from  between  the  rollers.  The  frame  is  formed  by  the  two  side  pillars  or 
walls  a,  «,  which  are  mortised  into  the  bottom  6,  b ;  and  are  firmly  fixed  to  it  by 
braces.  Two  transverse  rods  d,  d,  secure  the  base,  two  others  d'  d",  the  sides.  In  each 
of  these  a  lateral  arm  e,  is  mortised  in  an  oblique  direction ;  a  cross  bar  /,  unites  both 

arms.  Fig.  571  shows  the  inside  of 
the  left  side  of  the  frame,  with  the 
subsidiary  parts.  The  three  rollers, 
g,  i,  k,  may  be  made  of  red  beech, 
with  iron  gudgeons,  and  fluted  in 
their  length,  each  of  the  flutes  being 
Sjths  of  an  inch  broad,  and  ^^^ths  deep. 

he  large  roller  y,  bears  upon  the 
right  side,  a  handle  A,  which  on  being 
turned,  sets  the  whole  train  in  motion. 
The  side  partitions  a,  a,  are  furnished 
with  brasses  in  whose  round  holes,  /,  g, 
fig.  571,  the  gudgeons  g  work.  For 
the  extremities  of  the  two  smaller 
rollers,  there  are  at  a  and  e  slots 
in  brasses,  as  may  be  seen  in  fig. 
669.  Within  the  partition  a,  there 
are  movable  brasses  I,  for  the  pivots 
of  %  and  k,  shown  in  fig.  571.  Each 
brass  slides  in  a  groove,  between 
two  ledges.  A  strong  cord  made 
fast  at  m  to  the  partition  o,  runs 
over  the  brass  of  t,  next  over  that 
of  k,  then  descends  perpendicularly, 
1^  and  passes  over  the  cross  bar  n^ 
^N  jips.  669  and  570.  This  construc- 
,  tion  being  repeated  at  both  ends  of 

the  rollers,  the  rod  n  binds  both  cords.  Against  the  cross  bar  d'  of  the  frame, 
a  lever  o  is  sustained,  which  lies  upon  the  rod  n,  and  carries  a  weight  p.  The 
farther  or  nearer  this  weight  hangs  toward  the  end  of  the  lever,  it  stretches  the  cord 
more  or  less,  and  presses  by  means  of  the  brasses  /,  the  rollers  i,  k,  toward  the  main 
roller  g.  A  table  q,  serves  for  spreading  out  the  flax  to  be  broken,  and  a  second  one  r, 
for  the  reception  of  the  stalks  at  their  issuing  from  between  the  rollers.    Both  tablet 


^^ 


hang  by  means  of  iron  hooks  to  rings  of  the  frame  »,  t,  figs.  669  and  671,  and  are 
supported  by  the  movable  legs  w,  m,  w,  fign.  669  and  670.  In  using  the  machine  the 
operative  lays  an  evenly  spread  handful  of  flax  upon  the  table  q,  introduces  their  root 
ends  with  his  left  hand  between  the  rollers  g  and  t,  and  turns  round  the  handle  h,  with 
the  right  The  stems  are  first  broken  betwixt  g  and  «,  then  between  g  and  k,  and  come 
out  upon  the  table  r.  The  handle  is  moved  alternately  forward  and  backward,  in 
order  that  the  flax  may  be  rolled  alternately  in  the  same  directions,  and  be  more 
perfectly  broken.  The  boon  falls  down  in  very  small  pieces,  and  the  harl  remains 
expanded  in  parallel  bands.  This  should  be  drawn  over  the  points  of  a  heckle,  then 
laid  for  a  couple  of  days  in  a  cellar  to  absorb  some  moisture,  and  afterward  worked 
once  more  through  the  machine,  whereby  the  flax  acquires  a  peculiar  softness. 

The  advantages  of  this  brake  machine  are  chiefly  the  following : 

It  takes  up  little  room,  and  from  its  simplicity  is  easily  and  cheaply  constructed ;  it  re- 
quires no  more  power  to  work,  than  the  ordinary  hand-brake ;  it  tears  none  of  the  fila- 
ments, and  grmds  nothing  except  the  boon,  in  consequence  of  the  flutings  of  the  rollers 
going  much  less  deep  into  each  other,  than  the  sword  of  the  hand-brake ;  it  prevents  all 
entanglements  of  the  flax,  whence  in  the  subsequent  heckling  the  quantity  of  short  fibreg 
or  tow  is  diminished ;  and  it  accomplishes  the  cleaning  of  even  the  shortest  flax,  which 
cannot  be  well  done  by  hand  machines. 

The  comminution  of  the  boon  of  the  stems,  which  is  the  object  of  the  Ireaking 

process,  can  however  be  performed  by  thrashing  or  beating,  although  in  this  way  the 

•eparation  of  the  woody  matter  from  the  textile  fibres  is  much  less  completely  eflfected. 

"^  It  is  the  practice  in  Great  Britain,  instead  of 

breaking,   to    employ    a  water-driven  wooden 
mallet,  between  which  and  a  smooth  stone  the 
flax  is  laid.      In  that  part  of  Belgium  where 
the  preparation  of  flax  has  been  studied,  the 
brake  is  not  used,  but  beating  by  means  of  the 
Bott-hammer^  to  the  great  improvement,  it   is 
said,  of  the  flax.  The  Bott -hammer ^  Jig.  572,  is 
a  wooden  block,  having  on  its  under  face  chan- 
nels or  flutings,  5  or  6  lines  deep,  and  it  is  fixed 
to  a  long  bent  helve  or  handle.      In  using  it,  a 
bundle  of  the  dried  flax  stalks  is  spread  evenly 
upon  the  floor,  then  powerfully  beaten  with  the 
hammer,  first  at  the  roots,  next  at  the  points, 
and  lastly  in  the  middle.     When  the  upper  sur- 
face has  been  well  beat  in  this  way,  it  is  turned 
over,  that  the  under  surface  may  get  its  turn. 
The  flax  is  then  removed,  and  well  shaken  to 
free  it  from  the  boon. 

By  the  brake  or  the  hammer  the  whole  wood  is  never  separated  from  the  textile 
fibres,  but  a  certain  quantity  of  chaflfy  stuflf  adheres  to  them,  which  is  removed  by  another 
operation.  This  consists  either  in  rubbing  or  shaking.  The  rubbing  is  much  practised 
in  Westphalia,  and  the  neighboring  districts.  In  this  process,  the  operative  lays  the 
rubbm?  apron  on  a  piece  of  dressed  leather,  one  foot  square,  upon  her  knee ;  then  seizes 
a  bundle  of  flax  in  the  middle  with  her  left  hand,  and  scrapes  it  strongly  with  the  Ribbt- 
knife  held  in  her  right,  fig.  573.  This  tool,  which  consists  of  a  wooden  handle  s,  and  a 
thin  iron  blade  r,  with  a  bhint  and  somewhat  bent  edge,  acts  admirably  in  cleanin*'  and 
also  in  parting  the  filaments,  without  causing  needless  waste  in  flax  previously^  well 
broken.  ' 

The  winnowing,  which  has  the  very  same  object  as  the  rubbing,  is,  however,  much 
more  generally  adopted  than  the  latter.  Two  distinct  pieces  of  apparatus  belon«'  to  it, 
namely,  the  swing-stock  and  the  swing-knife.  The  first  consists  of  an  upright  boani  with 
a  groove  in  its  side,  into  which  a  handful  of  flax  is  so  placed  that  it  hand's  down  over 
half  the  surface  of  the  board.  While  the  left  hand  holds  the  flax  fast  above,  the  right 
carries  the  swmg-knife,  a  sabre^shaped  piece  of  wood  from  J|  to  2  feet  long,  planed  to 
an  edge  on  the  convex  side,  and  provided  with  a  handle.  With  this  knife  the  flax  is 
struck  parallel  to  the  board,  with  perpendicular  blows,  so  as  to  scrape  ofl!"  its  woody  asperi- 
ties. The  breadth  of  the  swing-knife  is  an  important  circumstance ;  when  too  narrow  it 
easily  causes  the  flax  to  twist  round  it,  and  thereby  tears  away  a  portion  of  the  fibres. 
When  8  or  10  inches  broad,  it  is  found  to  act  best.  Knives  made  of  iron  will  not  answer, 
for  they  injure  the  filaments. 

Figs.  574,  575  show  the  best  construction  of  the  swing-stock.  The  board  a  has 
for  its  base  a  heavy  block  of  wood  6,  upon  which  two  upright  pins  e  «,  are  fixed.  The 
band/,  which  is  stretched  between  the  pins,  serves  to  guide  the  swing-knife  in  its 
movements,  and  prevent  the  operative  from  wounding  his  feet.  The  under  edge  of  the 
groove  c,  upon  which  the  flax  comes  to  be  laid,  is  cut  obliquely  and  rounded  oif  (see  d 


UwMAAAWAwJ 


738 


FLAX. 


if- 


w'ff  in^re'lheXr  ^^^^""^  ^*'  '^^  swing-knife  can  never  strike  against  that  edge,  00 
Fig,  576  exhibits  the  form  of  a  very  convenient  implement  which  is  employed  in 

Belgium  instead  of  the  swing-knife.  It  is  a  sort  of 
wooden  hatchet,  which  is  not  above  two  lines  thick, 
and  at  the  edge  g  h  is  reduced  to  the  thickness  of  the 
back  of  a  knife.  The  fly  k  gives  force  to  the  blow, 
and  preserves  the  tool  in  an  upright  position.  The 
short  flat-pressed  helve  i  is  glued  to  that  side  of  the 
leaf  which  in  working  is  turned  from  the  swing-slock; 
and  is,  moreover,  fastened  wiih  a  wooden  pin. 

The  rubbing  and  swinging  throw  olf  the  coarsest 
sort  of  tow,  by  separating  and  shaking  out  the  shortest 
fibres  and  those  that  happen  to  get  torn.  That  tow  m 
used  for  the  inferior  qualities  of  sacking,  being  mixed 
with  many  woody  fibres. 

We  may  in  general  estimate  that  100  pounds  of 
the  stalks  of  retted  flax,  taken  in  the  dry  state,  affonf 
^    -     .  ,  .  from  45  to  48  pounds  of  broken  flax,  of  which,  in  th# 

swingmg  or  scutching,  about  24  pounds  of  flax,  with  9  or  10  pounds  of  scutch  tow  are 
oDtamed.  The  rest  is  boon-waste.  The  breaking  of  100  poundi  of  stalks  requires,  in  the 
ominary  rod..ne  of  a  double  process  by  hand,  about  20  hours;  and  with  the  above  de- 
scribed machine,  from  17  to  18  hours.  To  scutch  100  pounds  of  broken  flax  clean,  130 
Hours  oflabor  are  required  by  the  German  swinging  method. 

Mr.  Bundy  obtained  a  patent  in    1819,  for  certain  machinery  for  breaking  and  pre- 
paring  flax,  which  merits  description  here.    Fig.  577,  a  a  a  a,  is  the  frame,  made  either  of 
577 


FLAX. 


739 


wood  or  metal,  which  supports  the  two  conical  rollers  b  and  c.  These  revolve  independ- 
ently  of  each  other  m  proper  brass  bearings.  A  third  conical  roller  d  is  similarly 
supported  under  the  top  piece  e  of  the  machine.  All  these  rollers  are  frusta  of  cones 
made  of  cast  iron.  Whatever  form  of  tooth  be  adopted,  they  must  be^^so  shaped  and 
disposed  with  regard  to  each  other  as  to  have  considerable  play  between  them,  in  order 
to  admit  the  quantity  of  flax  stem  which  is  intended  to  be  broken  and  prepared.     The 

^^^IaK'^?u^  ""^ -^r  ""^^^'"^  '^^•'^^  *^"'*^^  t^  «PP"  conical  roller  d,  is  fixed  or  at- 
tached  to  the  mam  frame  a  a  a  a  by  strong  hinges  or  any  other  moveable  joint  a?G,  and 
rods  of  iron  or  other  sufficiently  strong  material;  h  h  is  attached  at  its  upper  end  by  a 
join  to  the  top  piece  e  through  a  ho  e  near  i,  and  is  fixed  at  its  lower  end  by  anoihe? 
joint  K  o  the  treadle  or  lever  k  i^  which  turns  upon  the  joint  or  hinges  m.  A  spring  or 
weight  (but  the  former  is  preferable  for  many  reasons)  is  applied  to  !he  machine  in  such 
manner,  that  its  action  will  always  keep  the  upper  piece  e,  and  consequently  the  upper 
roUer  D,  m  an  elevated  or  raised  position  above  the  rollers  b  and  c,  when  the  machine  ia 
not  in  ac  ion  ;  and  of  course  the  end  l  of  the  treadle  will  also  be  raised,  which  admits  of 
the  flax  to  be  worked  being  introduced  between  the  rollers,  viz.,  ov^r  the  two  lower 
roUers  b,  c,  and  under  the  upper  roller  d  ;  such  a  spring  may  be  applied  in  a  variety  of 
ways,  ••  between  the  top  piece  e,  and  the  top  or  platform  of  the  machine  at  n  •  or  it 


rollers  b,  g,  and  under  the  upper  roller  d  ;  such  a  spring  may  be  applied  in  a  variety  of 
ways,  as  between  the  top  piece  E,  and  the  top  or  platform  of  the  machine  at  n;  or  it 
may  be  a  strong  spiral  wire  spring,  having  its  upper  end  fastened  to  the  platform  while 
its  lower  extremity  is  fixed  to  the  rod  h  h,  round  which  it  coils  as  shown  at  o,  or  it  may 
be  placed  under  the  end  l  of  the  treadle ;  but  in  every  case  its  strength  must  be  no 
more  than  will  be  just  suflicient  to  raise  the  upper  roller  d  about  two  inches  from  the 
lower  rollers,  otherwise  it  will  occasion  unnecessary  fatigue  to  the  person  working  the 

machine. 

The  manner  of  using  it  is  as  follows :  the  upper  and  lower  rollers  being  separated  as 
aforesaid,  a  small  handful  of  dried  flax  or  hemp  stems  is  to  be  introduced  between  them, 
and  held  extended  by  the  two  hands,  while  the  rollers  are  brought  together  by  the  pres- 
sure of  the  foot  upon  the  treadle  l.  This  pressure  being  continued,  the  flax  or  hemp  is 
to  be  drawn  backwards  and  forwards  by  the  hands  between  the  rollers,  in  a  direction 
at  right  angles  to  their  axes,  and  eventually  withdrawn  by  pulling  with  one  hand  only. 
The  foot  is  now  to  be  removed  until  the  flax  or  hemp  is  again  replaced,  and  each  end 
is  this  way  to  be  drawn  several  times  through  the  machine,  until  such  ends  are  respec- 
tively finished. 

By  a  succession  of  these  operations,  using  the  pressure  of  the  foot  upon  l,  each  time 
that  the  flax  or  hemp  is  introduced  between  the  rollers,  and  regulating  such  pressure 
according  to  the  progress  of  the  work,  the  flax  or  hemp  will  soon  be  sufiiciently  worked 
and  the  fibre  brought  into  a  clean  and  divided  state  fit  for  bleaching ;  or  if  it  be  re- 
quired to  spin  it  in  the  yellow  state,  it  maj^  be  made  suflaciently  fine  by  a  longer  con- 
tinuation of  the  same  process,  particularly  if  worked  between  the  smaller  ends  of  the 
rollers. 

Indeed,  the  operation  may  be  commenced  and  continued  for  some  time,  with  the 
larger  part  of  the  rollers,  and  finished  with  their  smaller  ends;  and,  in  this  point  of 
view,  the  invention  of  conical  rollers  will  be  found  both  convenient  and  useful ;  for  as 
the  flutes,  grooves,  or  teeth  vary  in  their  distance  from  each  other  at  all  points  between 
the  large  and  small  ends,  so  it  becomes  almost  impossible  for  the  workman  to  draw  the 
flax  or  hemp  through  such  rollers  in  the  same  track  ;  and  thus  the  breaking  of  the  boon 
must  be  much  more  irregular,  and  the  fibre  will  be  much  more  efi"ectually  cleansed  than 
it  can  be  by  the  flutes,  grooves,  or  teeth  of  cylinders,  or  other  such  contrivances  formerly 
employed ;  because  they  would  probably  fall  frequently  upon  the  same  points  of  the 
fibres.  If  it  is  intended  that  the  flax  shall  be  bleached  before  it  is  spun,  then  the  second 
part  of  Mr.  Bundy's  invention  may  be  had  recourse  to,  which  consists  in  moving  certain 
tra3S  or  cradles  in  the  water,  or  other  fluid  used  for  bleaching  the  flax  or  hemp  in  the 
manner  following,  viz. :  The  flax  or  hemp,  after  having  been  broken  and  worked  in  the 
machine,  should  be  divided  into  smaller  quantities  of  about  one  ounce  each,  and  these 
should  be  tied  loosely  in  the  middle  with  a  string,  and  in  this  state  laid  in  the  trays  or 
cradles,  and  then  be  soaked  in  cold  soft  water  for  a  day  or  two,  when  each  parcel  should 
be  worked  separately,  w^hile  wet,  through  a  machine,  precisely  similar  to  that  already 
described,  except  only  that  the  rollers  should  be  cylindrical,  and  made  entirely  of  wood 
with  metal  axles,  and  the  teeth,  which  will  be  parallel,  should  be  similar  in  form  to 
those  shown  in  section  at  q.  Jig.  578.  Such  operation  will  loosen  the  gluten  and  colouring 
matter,  for  the  rinsing  and  wringing  which  must  follow.  The  flax  must  then  be  again 
disposed  in  a  flat  and  smooth  manner,  in  such  trays  or  cradles,  and  once  more  set  to 
soak  in  suflScient  soft  water  to  cover  it,  in  which  a  small  quantity  of  soap,  in  the  pro- 
portion of  about  seven  pounds  of  soap  to  each  hundred  weight  of  flax,  has  been  pre- 
viously dissolved,  and  in  this  state  it  should  remain  for  two  or  three  days  longer,  and 
then  be  finally  worked  through  the  machine,  rinsed  with  clear  water,  and  wrung : 
which  will  render  it  sufficiently  white  for  most  purposes. 

Can  fax  be  prepared  without  retting  ? — The  waste  of  time  and  labour  in  the  steeping 
of  flax ;  the  dyeing  of  the  fibres  consequent  thereon,  which  must  be  undone  h\  bleach- 
ing ;  the  danger  of  injuring  the  staple  by  the  action  of  putrescent  water ;  and,  lastly, 
the  diminished  value  of  flax  which  is  much  water-retted,  are  all  circumstances  which 
have  of  late  years  suggested  the  propriety  of  superseding  that  process  entirely  by 
mechanical  operations.  It  was  long  hoped,  that  by  the  employment  of  breaking 
machines,  the  flax  merely  dried  could  be  freed  from  itis  woody  particles,  while  the  tex- 
tile filaments  might  be  sufficiently  separated  by  a  subsequent  heckling.  Experience 
has,  however,  proved  the  contrary.  The  machines,  which  consisted  for  the  most  part  of 
fluted  rollers  of  iron  or  wood,  though  expensive,  might  have  been  expected  to  separate 
the  ligneous  matter  from  the  fibres ;  but,  in  the  further  working  of  the  flax  no  advan- 
tage was  gained  over  the  water-retting  process. 

1.  Unretted  flax  requires  a  considerably  longer  time  for  breaking  than  retted,  under 
the  employment  of  the  same  manipulations. 

2.  Unretted  stalks  deliver  in  the  breaking  and  heckling  a  sonaewhat  greater  product 
than  the  same  weight  of  flax  which  has  been  retted ;  but  there  is  no  real  advantage  in 

5  B  2 


740 


FLAX. 


this^  as  the  greater  weight  of  the  unretted  flax  consists  in  the  remainder  of  ligneous  or 
glutinous  matter,  which  being  foreign  to  the  real  fibre,  must  be  eventually  removed. 
In  the  bleaqhing  process,  the  water  and  the  alkaline  lyes  take  away  that  matter,  so  that 
the  weight  of  the  bleached  fibre  is  not  greater  from  the  unretted  than  the  retted  flax. 

3.  The  parting  of  the  fibres  in  the  unretted  stalks  is  imperfectly  effected  by  the 
heckling ;  the  flax  either  remains  coarser  as  compared  with  the  retted  article,  and  affords 
a  coarser  thread,  or  if  it  be  made  to  receive  greater  attenuation  by  a  long-continued 
heckling,  it  yields  incomparably  more  torn  filaments  and  tow. 

4.  The  yam  of  unretted  flax  feels  harder,  less  glossy,  and  rougher ;  and,  on  account 
of  these  qualities,  turns  out  worse  in  the  weaving  than  the  retted  flax.  If  or  is  the  yam 
of  unretted  flax,  whether  unbleached  or  bleached,  in  any  degree  stouter  than  the  yam 
of  the  retted  flax. 

6.  Fabrics  of  unretted  flax  require  for  complete  bleaching  about  a  sixth  less  time  and 
materials  than  those  of  the  retted.  This  is  the  sole  advantage,  but  it  is  more  than 
counterbalanced  by  the  other  drawbacks  above  specified. 

The  foregoing  operations  having  brought  the  flax  into  the  ordinary  fibrous  merchan- 
table state,  suitable  for  the  spinner,  it  now  remains  to  pass  through  the  following  pro- 
cesses, by  which  it  is  manufactured  into  yarns  for  sale  or  use,  viz.,  Ist,  heckling,  2nd, 
preparing,  3rd,  spinning,  4th,  reeling,  5th,  drying,  and  6th,  making  up. 

6.  Heckling.  The  operation  of  heckling  has  for  its  objects,  1st,  that  of  combing 
or  straightening  the  filaments  entangled  as  coming  from  the  scutching.  2d,  that  of 
splitting  them,  with  a  view  of  lessening  and  equalizing  their  size.  In  accomplishing 
these  objects  the  material  is  unavoidably  divided  into  two  portions.  The  long  and 
straight  fibres  constituting  the  first,  called  "  line,"  and  the  short,  broken,  and  confused 
of  the  second,  "  tow."  Both  the  line  and  tow  are  capable  of  being  spun,  but  the  line  is 
much  the  more  valuable,  being  used  for  the  better  descriptions  of  yams,  Ac,  with 
greater  facility  than  the  tow  for  the  inferior.  The  aim,  therefore,  of  good  heckling  is  to 
produce  the  larger  proportion  of  line  from  a  given  quantity  of  flax,  the  attainment  of 
which  leaves  much  scope  for  care  and  judgment,  whether  the  older  method  of  heck- 
ling by  hand  or  the  more  recent  by  machine  is  adopted.  In  hand  heckling  the 
instmments  are  a  comb-fashioned  tool,  called  the  heckle  or  hdckle  :  a  surface  studded 
more  or  less  thickly  with  metal  points,  called  heckle  teeth ;  over  v.  hich  the  flax  is  drawn 
in  such  a  way  that  the  above  three  required  operations  may  be  properly  accomplished. 

The  heckles  ordinarily  used  for  hand  heckhng  in  this  country  are  in  the  form  of 
rectangular  parallelograms,  presenting  a  line  of  7  inches  towards  the  worker  and  4  to  5 
inches  deep.  The  first  tool  employed  is  called  the  "  ruffer,"  the  pins  of  which  are  about 
\  inch  square  at  their  base,  and  7  inches  long,  and  brought  to  a  fine  point ;  the  second  is 
the  "  common  8,"  which  is  always  used  after  the  "  ruffer ;"  then  the  "  fine  8,"  the  "  10,"  the 
"12,"  the  "  18."  The  pins  of  all  these  tools  are  similarly  placed  to  those  of  the  ruffer, 
but  are  somewhat  shoHer  in  length  and  are  more  slender  as  the  tools  increase  in  fineness. 
In  all  these  tools  the  pins  are  held  in  wooden  stocks  of  about  f  inch  in  thickness  and 
covered  with  sheet  tin.  This  sheet  tin,  through  which  the  pins  are  driven,  helps  to  sup- 
port them  and  prevent  the  wood  from  splitting.  These  tin  covered  stocks  are  only  of  a 
size  necessary  for  the  extent  of  pins  employed,  and  are  themselves  screwed  to  other  larger 

pieces  of  board,  a  little 
5801 


579 


11 


C 


broader  and  some  inches 
longer    than    themselves, 

. ^ and    by  which  they   are 

*'  '  '   ultimately    fixed    to    the 

heckler's  bench,  inclining 
somewhat  backward  with 
their  points  from  the 
worker,  and  a  sloping 
board  behind  to  prevent 
the  flax  entering  too 
much  in  the  pins, 
thus : 

Fig.     579.     end     view 

of    a    heckle ;  Jig.    580. 

581         front    view    of     heckle ; 

fig.      581.      heckle,      Ac. 

fixed  up  for  working,  a  pins ;  6  tin  covered  stock ;  c  foundation  board ;  d  beam  of  table 
or  bench ;  e  back  board ;  /  table  to  receive  the  tow,  Ac. ;  g  hand  of  workman.  Such  ia 
the  form  of  heckle  used  in  England,  and  also  the  manner  they  are,  of  whatever  descrip- 
tion, fixed  for  work. 


f 


582 


FLAX.  "^^l 

In  Germany  the  common  construc- 
tion of  the  heckle  is  the  following;  (see 
fi^.  582.)  Fig.  682.  is  the  groimd 
plan,  &na fig.  583.  is  the  section.  Upon 
an  oblong  plank  a  b,  two  circular  or 
square  blocks  of  wood  c  and  d  are 
fixed,  in  which  the  heckle  teeth 
stand  upright  To  give  these  a 
firmer  hold  they  are  stuck  into  holes 
in  a  brass  or  iron  plate,  'with  which 
the  upper  surface  of  c  and  d  is  covered. 
]3oth  heckles  may  be  either  asso- 
ciated upon  one  board  or  separated ;  and  of  different  finenesses ;  that  is,  the  teeth  of  the 
one  may  be  thinner,  and  stand  closer  together ;  because  the  complete  preparation  of  the 
flax  requires  for  its  proper  treatment,  a  two-fold  heckling ;  one  upon  the  coarse,  and  one 
upon  the  fine  heckle  ;  nay,  sometimes  3  or  4  heckles  are  employed  of  progressive  fineness. 
The  heckle  teeth  are  usually  made  of  iron,  occasionally  of  steel,  and  from  1  to  2  inchea 
long.  Their  points  must  be  very  sharp  and  smooth,  all  at  an  e^ual  level,  and  must  all 
graduate  very  evenly  into  a  cylindrical  stem,  like  that  of  a  sewing  needle,  without  any 
irregularity.  The  face  of  the  heckle  block  must  be  uniformly  beset  with  teeth,  which 
is  done  by  different  arrangements,  some  persons  setting  them  in  a  circle,  and  others  in 
parallel  rows.  The  coarse  heckle  is  furnished  with  teeth  about  one-tenth  of  an  inch 
thick,  one  and  a  quarter  of  an  inch  long,  and  tapering  from  the  middle  into  a  very  fine 
point  In  the  centre  of  the  circular  heckle  is  a  tooth  planted ;  the  rest  are  regularly 
set  in  12  similar  concentric  circles,  of  which  the  outermost  is  5f  inches  in  diameter. 
The  fine  heckles  contain  no  fewer  than  1,109  teeth.  Instead  of  making  the  points  of 
the  teeth  round,  it  is  better  to  make  them  quadrangular,  in  a  rhombus  form,  m  which 
case  the  edges  serve  to  separate  or  dissect  the  fibres. 

The  operation  of  manual  heckling  is  simple  in  principle,  although  it  requires  much 
experience  to  acquire  dexterity. 

The  workman  having  first  divided  the  flax  into  handfuls  or  stricks,  of  which  there 
are  300  to  400  to  the  cwt,  proceeds  to  grasp  one  as  flatly  spread  as  possible  between  his 
forefinger  and  thumb,  by  about  its  middle,  and  wind  the  top  end  round  his  hand  in  order 
the  better  to  prevent  the  slipping  of  the  fibres ;  he  then  begins  by  a  circular  swing  of 
his  arm  to  lash  the  root  end  into  the  heckle,  taking  care  to  comnience  as  near  the 
extremity  as  possible,  now  and  then  collecting  the  fibres  by  holding  his  left  hand  in  front 
of  the  tool,  turning  the  strick  from  time  to  time ;  he  thus  gradually  works  up  as  near  as 
possible  to  his  right  hand,  when  he  seizes  the  ruffed  part  of  the  strick  and  holds  it  in 
the  same  manner  as  at  first  and  proceeds  by  similar  treatment  to  "  raff"  the  top  end ; 
when  this  is  finished  the  "ruffed"  work  is  taken  to  the  tool  called  a  "common  8,"  the 
pins  of  which  are  much  closer  placed  than  those  of  the  ruffer,  and  are  only  4  or  5 
inches  long.  This  "  8 "  is  always  used  after  the  ruffer,  but  from  it  the  work  can  be 
taken  to  any  of  the  finer  tools,  viz.  8,  10,  12,  and  sometimes  18.  It  is  usual  and  better 
to  dress  both  ends  over  each 'tool  before  taking  the  work  to  the  next  The  pins  of  all 
these  tools  are  4  inches  long,  in  order,  as  was  supposed,  to  have  sufficient  spring.  The 
flax  is  not  lashed  into  them  as  into  the  ruffers,  neither  are  the  ends  required  to  be 
wound  round  the  hand-  But  the  root  end  of  the  flax  is  always  the  one  to  be  first 
worked,  and  the  heckling  begun  at  nearly  the  extremity  of  the  strick,  which  on  being 
drawn  through  the  heckle  is  received  by  the  left  hand  of  the  workman,  and  by  it  car- 
ried back  and  laid  upon  the  back  board  and  over  the  point  of  the  pins,  for  the  angle 
of  inclination  of  the  heckles  and  a  slight  lowering  of  the  right  hand  causes  it  to  enter 
sufficiently  on  being  drawn  forward.  As  it  is  impossible  to  ruff  or  dress  entirely  up  to 
the  hand,  when  the  hold  is  changed  in  either  operation,  there  must  of  necessity  be  left 
a  certain  space  to  be  repassed  through  the  tools ;  this  is  called  the  "  shift,"  but  the 
less  length  that  is  required  for  this  purpose  the  better  for  the  yield  of  lime.  The 
numerous  long  fibres  that  slip  from  the  strick  in  mffing  must  be  collected  and  drawn 
from  the  mass  of  tow  attached  to  them,  when  they  can  be  relaid  in  the  strick,  or  kept 
to  be  dressed  separately  under  the  name  of  "  shorts,"  and  from  time  to  time  the  short 
fibres  or  tow  sticking  to  the  teeth  of  the  finer  tools  are  removed.  Whenever  one- 
half  of  the  length  of  the  strake  of  flax  is  heckled,  it  is  turned  round  to  heckle  the 
other  half.  This  process  is  repeated  upon  each  heckle.  From  100  pounds  of  well- 
cleaned  flax,  about  45  or  50  pounds  of  heckled  line  may  be  obtained  by  the  hand 
labour  of  12  hours ;  the  rest  being  tow,  with  a  small  waste  in  bony  particles  of  dust 
The  process  is  continued,  till  by  careful  handling  little  more  tow  is  formed. 

To  aid  the  heckle  in  splitting  the  filaments,  three  methods  have  been  had  recourse 
to ;  beating,  brushing,  and  boiling  with  soap-water,  or  an  alkaline  lye. 

Beating  flax  either  after  it  is  completely  heckled,  or  between  the  first  and  second 


142 


FLAX, 


FLAX. 


YiS 


heckling,  is  practised  in  Bohemia  and  Silesia.  Each  heckled  tress  of  flax  is  folded  in 
the  middle,  twisted  once  round,  its  ends  being  wound  about  with  flaxen  threads ;  and 
this  head,  as  it  is  called,  is  then  beat  by  a  wooden  mallet  upon  a  block  and  repeatedly 
turned  round  till  it  has  become  hot  It  is  next  loosened  out,  and  rubbed  well  between 
the  hands.  The  brushing  is  no  less  a  very  proper  operation  for  parting  the  flax  into  fine 
filaments,  softening  and  strengthening  it  without  risk  of  tearing  the  fibres.  This  pro-, 
cess  requires  in  tools,  merely  a  stiff  binish  made  of  swines'  bristles,  and  a  smooth 
board,  3  feet  long  and  1  foot  broad,  in  which  a  wooden  pin  is  made  fast  The  end  of 
the  flax  is  twisted  two  or  three  times  round  this  pin  to  hold  it,  and  then  brushed 
through  its  whole  length.  Well  heckled  flax  suffers  no  loss  in  this  operation;  un- 
heckled,  only  a  little  tow ;  which  is  of  no  consequence,  as  the  waste  is  thereby 
diminished  in  the  following  process.  A  cylindrical  brush  turned  by  machinery  might 
be  employed  here  to  advantage.  These  have  been  tried  in  establishments  for  machine 
spinning,  but  not  found  advantageous. 

The  boiling  of  flax  with  potash  lye  alone,  or  with  lye  and  soap,  dissolves  that  portion 
of  the  glutinous  cement  which  had  resisted  the  retting,  completes  the  separation  of  the 
fibres,  and  was  therefore  supposed  a  good  practical  means  of  improving  flax.  When 
it  is  performed  upon  the  heckled  fibres,  a  supplementary  brushing  is  requisite  to  free 
it  from  the  dust,  soapy  particles,  Ac,  but  this  also  is  now  abandoned. 

Machine  heckling. — ^As  intimated  above,  the  object  of  all  heckling  was  that  of  pro- 
ducing a  good  yield  of  line  with  tows  of  good  quality,  that  is  to  say,  free  from  broken 
unsplit  fibres,  lumps  and  knots :  the  care  and  attention  to  do  this,  together  with  the 
expense  and  uncertain  results  of  the  individual  skill  of  workmen,  urged  manufacturers 
some  time  since  to  attempt  the  establishment  of  machines  for  dressing  flax  mechanically. 
Therefore  many  contrivances  have  been  made  with  this  view,  but  it  was  long  doubted 
whether  any  of  them  made  such  good  work  with  so  little  loss  as  hand  labour.  In 
heckling  by  the  hand,  it  was  siipposed  the  operative  would  feel  at  once  the  degree  of 
resistance,  and  be  able  to  accommodate  the  traction  to  it,  or  throw  the  flax  more  or  less 
deeply  among  the  teeth,  according  to  circumstances,  and  draw  it  with  suitable  force  and 
velocity.  For  a  considerable  period  these  ideas,  or  rather  prejudices  as  they  may  now 
be  called,  seemed  to  be  confirmed :  for  the  earlier  attempts  to  supersede  hand  heckling, 
like  those  in  many  other  undertakings,  though  partially  favourable,  were  upon  the  whole 
somewhat  discouraging :  in  attaining  one  point  desired  another  one  was  lost,  for  too  much 
still  depended  upon  the  care  and  attention,  if  not  upon  the  actual  skill,  of  the  attendants. 
Therefore,  a  review  of  those  machines  that  really  came  into  operation,  to  a  more  or  less 
limited  extent,  as  well  as  a  slight  mention  of  some  of  those  patented,  but  never  publicly 
shown,  may  not  be  useless  as  a  lesson  for  preventing  a  repetition  of  things  already 
known,  as  well  also  for  illustrating  the  steps  by  which  these  first  prejudices  have  been  gra- 
dually overcome.  The  first  heckling  machine  invented,  or  at  least  published,  was  called 
the  "  Peter,"  and  was  intended  to  imitate  as  closely  as  possible  the  movements  of  the 
hand  heckles.  In  commencing  the  work,  the  flax  was  fii*st  divided  into  small  convenient 
portions  or  handfuls,  of  about  4  ounces  each,  called  "  stricks,"  and  which,  before  being 
taken  to  the  machine,  were  slightly  straightened  and  dressed  over  the  ordinary  hand 
•'  ruffer."  Each  of  these  stricks  was  then  placed  between  a  pair  of  short  iron  bars,  one 
of  these  bars  having  an  indentation  along  its  middle,  and  the  other  a  corresponding 
projection  ;  thus,  when  tightened  together  by  screws  4-^  inches  apart  (such  a  length  being 
equal  to  a  hand-heckler's  grasp),  the  flax  was  firmly  held  while  exposed  to  the  action  of 
the  heckles,  (this  pair  of  bars  with  screws  being  called  a  "  holder  ").  This  holder  was 
then  suspended  from  movable  levers  over  a  truncated  rectangular  cylinder,  upon  the 
truncated  angles  of  which  were  fixed,  at  a  certain  angle,  heckles  similar  to  those  used  in 
the  manual  operation.  The  levers  supporting  the  holders  received  from  a  crank  a  short 
up  and  down  motion,  so  timed  in  their  oscillations  as  to  strike  the  holder  nearly  against 
the  points  of  the  pins  at  the  time  thej  were  passing  under,  coming  thus  as  nearly  as  pos- 
sible to  the  effect  of  a  man  striking  in  and  drawing  through  the  heckles,  with  the  ex- 
ception that  the  flax  remained  nearly  stationary,  and  the  heckle  was  drawn  through  it  by 
the  rotation  of  the  cylinder ;  such  machine  carried  two  holders.  The  tow  made  and  col- 
lected in  the  heckles,  was  seized  and  taken  off  by  boys  stationed  for  that  purpose,  while 
another  at  the  ring  of  a  bell  took  out  and  changed  the  sides  of  the  stricks  to  be 
presented  to  the  action  of  the  heckles,  and  subsequently  withdrew  them  from  the  first 
machine  to  another  similar  but  with  finer  heckles,  and  thus  continued  till  the  root  «nd 
(always  the  first  to  be  operated  upon)  was  dressed  to  the  desired  degree  of  fineness,  when 
they  would  be  taken  to  a  table  where  another  set  of  boys,  previously  to  removing  the 
first  holder,  put  on  a  second  to  the  already  heckled  part,  leaving  a  short  length  of  2^ 
or  3  inches  to  be  reheckled.  This  operation  is  termed  shifting,  and  the  space  left  the 
, "  shift,"  and  is  thus  performed  and  so  called  at  the  present  day  ;  the  only  change  in  the 
holder  now  in  use  being,  that  one  screw  is  used  for  two  stricks  instead  of  two  screws 
for  one  strick.     Fig.  584.  will  more  clearly  show  the  construction  of  this  machine. 


A  square  truncated  cylinder  carrying  the 
heckles ;  b  oscillating  arm  or  lever  for  support- 
ing the  holder;  c  o  c  fi:aming;  d  crank  and 
shaft;  B  connecting  rod  from  crank  to  oscil- 
lating arm ;  f,  f,  f,  f  heckles ;  g  g  g  g  back  board ; 
u  holder.  The  first  motion  was  given  by  pulleys 
on  the  shaft  d,  which  revolved  4  times  to  1  of 
the  heckle  cylinder,  by  the  intervention  of 
suitable  wheels.  The  worm  and  wheels  for  the 
bell  motion  were  attached  in  the  usual  manner 
to  the  shaft  of  the  cylinder. 

Machines  of  this  construction  continued  in 
rather  limited  use  without  any  change  or 
competition  till  about  the  year  1826,  when  a 
patent  was  taken  for  a  machine  known  as  the 
pendulum  machine.  The  flax  in  the  holder 
being  suspended  and  swung  backwards  and 
forwards  while  the  heckle  remained  fixed,  thus 
the  flax  was  heckled,  stroke  for  stroke,  on  each 
of  its  sides.  The  boys  as  in  the  last  described,  snatching  off  the  tow  as  it  was  formed, 
and  at  certain  times,  that  is  at  each  rise  of  the  pendulum,  for  it  had  a  rising  and  fall- 
ing motion  to  imitate  the  hand  workers  in  commencing  at  the  extreme  end  of  the  flax, 
passing  the  holder  from  one  recess  to  another  of  the  pendulous  table,  so  as  to  arrive  at 
the  progressively  finer  tools  when  ranged  along  the  machine,  but  sometimes  the  differ- 
ent tools  were  fixed  upon  the  angles  of  a  square  cylinder  that  presented  a  finer  range, 
the  whole  length  of  the  machine,  by  turning  up  a  new  angle  at  each  rise  of  the  pendu- 
lum, when  the  labour  of  the  boys  was  simply  to  put  in  the  tow  and  take  out  from  it  the 
flax.  The  adjoining  diagram,  (jig.  585.)  without  entering  on  any  details  of  a  machine 
that  was  so  little  used,  will  make  the  theory  of  its  action  quite  clear. 

—  A  heckle    bench   sometimes  re- 

volving so  as  to  present  different 
degrees  of  heckles  at  its  various 
angles,  sometimes  stationary  with 
the  gradations  of  heckles  upon  its 
length ;  b  b,  pendulum  arras ;  c  c, 
equal  wheels  working  into  each 
other ;  d  d,  crank  arms ;  k  radial 
slide-bars  to  preserve  the  holder 
table  vertical ;  h,  holder  table ; 
F,  f,  f,  f,  heckles ;  o,  g,  back  boards ; 
1 1,  direction  in  which  the  holders 
swing ;  there  were  the  same  wheels, 
Ac,  at  each  end  of  the  machine, 
and  the  holder  table  h  reached 
from  one  to  the  other.  The  wheels 
c,  c,  with  all  attached  to  them,  were 
made  to  rise  and  lower  upon  the 
heckles,  and  the  back-boards  g  to 
rise  when  the  heckle  bench 
turned. 

About  the  same  time  another 
patent  was  taken  out  for  a  machine, 
where  the  holders  were  suspended 
above  one  end  of  a  travelling  sheet 
of  heckles.  This  machine  also 
required  hand  labour  to  turn  and  transfer  the  stricks,  though  the  tow  was  caused  to 
fall  clear  from  the  heckles  by  mechanical  means.  The  following  sketch  {fig.  586. )  shows 
the  principle  upon  which  this  machine  works,  and  though  never  much  employed  at 
the  time  of  its  appearance,  has  subsequently  served  as  a  foundation  for  those  that  are 
now  in  the  zenith  of  their  prosperity.  *     i.i.     v    i. 

A  A  {fig.  586.)  sheet  of  heckles ;  b  support  for  holders;  c,  c  carrier  puUeys  for  the  sheet 
of  heckles.  Fig.  587.,  a  larger  view  of  the  heckle  bar  g  g,  in  order  better  to  show  the 
faller  d  d  d  in  the  staples  or  grooves  e,  e,  and /a.  588.  at  the  end  of  the  heckle-bar  q  g  ; 
F  F  pins  of  the  heckles,  between  the  rows  of  which  the  faller  d  d  d  acts  to  Push  the 
tiw  off  the  pins.  There  is  a  clearing  faller  d  to  each  heckle,  which  is  kept  to  the  bot- 
tom of  the  heckles  at  that  part  of  their  course  where  they  are  in  contact  with  the  flax, 
but  at  the  turn  f  d  fly  beyond  the  points,  as  shown  by  the  effect  of  the  centrifugal  force. 
All  these  machines^  possessing  great  sunilarity  of  features  in  regard  to  the  personal 


744 


FLAX. 


i 


686 


sm — wm e^    ^ ml 


ma. — ^ — Ea — Eza — y/.t^    i^.>tji 


dG 


attention  required,  never  came  into  such  general  operation  as  to  supersede  entirely 
hand-dressing,  either  from  their  own  defects  or  prejudices  against  their  employment 
About  the  year  1830,  in  consequence  of  the  new  mode  of  spinning,  hereafter  to  be  de- 
scribed, being  carried  on  with  considerable  energy,  it  was  found  advantageous  to  cut  the 
flax  into  2,  3,  or  more  lengths  previously  to  heckling,  which  rendered  it  necessary  to  have 
machines  peculiarly  adapted  for  this  new  short  description  of  material.  This  machine, 
known  as  the  excentric  or  circular  machine,  deserves  considerable  attention  for  its  own 
inherent  merits,  and  the  extensive  utility  it  has  proved  to  be  of  in  suggesting  the 
principal  parts  of  those  by  which  it  has  been  sufiplanted.  In  its  original  form  it  was 
made  of  a  breadth  suitable  for  only  one  strick,  and  consisted  of  a  cylinder  3  ft  diameter, 
upon  the  whole  circumference  of  which  at  intervals  of  3  or  4  inches  were  fixed  the 
heckles.  As  each  machine  could  only  carry  one  description  of  heckle,  it  was  neces- 
sary to  employ  a  series  of  these  machmes,  called  a  "  class,"  when  the  flax  reauired  to 
be  dressed  over  a  succession  of  finer  tools,  each  succeeding  machine  carrying  a  finer  tool 
than  its  predecessor.  The  heckles  were  cleared  of  tow  by  coming  in  contact  at  one 
part  of  their  revolution  with  a  brush  roller,  which  also  revolved  in  contact  with  a 
cylinder  covered  with  card  clothing,  the  points  of  the  pins  being  in  such  a  direction  as 
to  clear  the  brush  from  tow,  and  allow  itself  to  be  in  its  turn  cleared  by  the  oscillations 
of  a  comb,  whence  by  rollere  the  tow  was  brought  into  a  sliver.  In  order  to  preserve  the 
continuity  of  the  supply  of  tow,  and  maintain  the  regularity  of  the  sliver  produced  by  it, 
the  holders  with  the  flax  were  presented  to  the  heckle  cylinder  in  a  manner  peculiar  to 
this  machine,and  in  endless  succession  by  means  of  certain  circular  carriers  placed  at  each 
end  of  the  heckle  cylinder,  but  excentric  thereto,  and  at  such  a  distance  apart  as 
each  should  bear  one  end  of  the  holder  as  it  extended  across  the  cylinder  parallel 


\IU 


FLAX. 


745 


to  its  axle.  Thus,  the  holders  introduced  at  that  part  of  the  circumference  of  these 
carriers  furthest  from  the  heckles  were  carried  forward,  while  the  flax  was  in  opera-* 
tion,  till  they  were  brought  almost  into  contact  with  the  points  of  the  pins,  when  by 
the  intervention  of  a  slide  they  were  withdrawn  from  the  machine,  but  with  one  side 
only  of  the  flax  dressed,  and  that  but  on  one  tool ;  therefore,  the  holder  required 
replacing  in  the  same  machine,  in  order  that  the  second  side  of  the  strick  should  be 
dressed  as  was  the  first  The  holders  then  required  to  be  carried  by  hand  to  each 
succeeding  machine  of  the  class. 

The  preceding  figure  (589.)  shows  the  leading  features  of  these  machines: 

A  A  {Jig.  589.)  heckle  cylinder;  bb  excentric  wheel  to  carry  holders  in  its  recesses 
hj  h,  Jiy  h^h,;  0  slide  upon  which  the  holders  were  laid  so  as  to  fall  into  the  recesses 
h,  hoi  wheel  b ;  x>  slide  for  taking  out  holders ;  e  brush  cylinder  with  brushes ;  g 
cylinder  covered  with  card  clothing ;  h  holder  come  out ;  i  doffing  comb.  The  space 
of  the  holder  carrying  wheel  was  filled  with  holders,  and  so  maintained  in  endless 
succession,  and  thus  each  served  in  some  measure  to  keep  the  end  of  its  preceding 
one  down  into  the  heckles. 

About  1833,  a  machine  was  patented  consisting  of  two  parallel  cylinders,  over 
which  the  flax  was  carried,  revolving  in  its  progress  so  as  to  present  the  alternate 
sides  of  the  strick  to  the  heckles,  the  progressively  finer  tools  being  ranged  along  these 
cylinders,  so  that  having  passed  the  length  of  one  cylinder  one  end  was  completely 
finished.  "When  the  holder  was  taken  out,  "  shifted,"  and  replaced,  it  was  carried 
back  along  the  second  cylinder,  and  thus  returned  to  where  it  conmienced,  finished. 
This  machine,  however,  never  was  carried  further  than  the  experimental  one  for  the 
patent 

Another  machine  the  same  year  made  its  appearance,  and  which  for  some  time  en- 
joyed much  celebrity.  It  consisted  of  two  parallel  vertical  sheets  of  heckles  running 
together,  and  so  geared  that  the  heckles  of  one  intersected  the  interstices  of  the  other. 
The  flax  suspended  in  its  holder  from  a  species  of  trough  passed  between  these  two 
sheets,  and  was  thus  heckled  simultaneously  on  each  side  in  its  course  through  the 
progressively  finer  heckles  from  one  end  of  the  machine  to  the  other. 

A,  A  (690.)  heckle  sheets ;  b  b  holder  trough  or  slide ;  c,  c;  c,  c,  pulleys  for  carrying  the 


heckle  sheets ;  n,  d  brush  rollers ;  k,  e  rollers  covered  with  card  clothing  to  clear  the 
brushes  ;  f,  f  doffer  combs ;  g,  g,  g,  g  heckles ;  h  holder ;  i,  i  brushes. 

At  about  the  same  period  a  foreign  machine  was  patented,  known  as  Evans's  ma- 
chine, of  which  the  following  description  will  give  a  correct  idea  of  its  principle 
of  action,  and  also  of  its  holders,  which  are  different  from  those  already  described. 

Vol.  L  2  a 


Y46 


FLAX 


There  are  two  series  of  combs,  see^igr.  691.,  attached  to  two  movable  frames  represented 
"^  """      ~  at  a  and  6.  Each  frame  is  formed  by  vertical 

bars  a  6,  with  lateral  branches  or  arms, 
which  carry  the  heckle  points.  The  branch- 
es or  arms  are  parallel,  and  at  equal  dis 
tances  apart,  but  fixed  in  such  positions  in 
gggCach  frame  that  they  may  occupy  the  inter- 
vening space  when  the  frames  are  brought 
together  a^Jig.  592.  The  frames  are  put  in 
motion  by  means  of  revolving  cranks  to 
which  they  are  attached  as  shown  in  /«. 
692.,  and  when  the  cranks  turn  upon  their 
axes,  the  branches  of  one  frame  pass  be- 
tween those  of  the  other  without  touching. 
This  forms  what  may  be  called  a  set  of 

\^-„ 3  .    ^1         .         „    ,  combs ;  the  points  of  the  combs  of  one  set 

bemg  opposed  to  the  pomts  of  the  combs  in  the  other  set. 

«l,nw«  ^^l^""  ^}^''^^-  *^^«e"es  of  combs  that  compose  one  set  act  upon  the  flax,  is 
shown  m  the  side  view  /^r.  591.  When  the  cranks  are  nearly  verticaVUie  pobt^of 
both  frames  are  away  from  the  flax,  but  as  the  cranks  move  roUd  in  the  dfreTon  of 

he:klTo?one  of  t^  ^r"'  ''i'  ^"^.'^^^  P^^^^^^"'  ^"^  ''  '^  ^^^  thIrtheToln"  or 
or XTde  itrfiw!  5?°^"%^,^^^^^*^,  penetrate  the  flax,  and  descending  they  comb 
or  divide  its  fibres.     The  rotation  of  the  cranks  continuing,  the  two  frames  a  and  h 

tr flaTand'  tCe'o?  ^T  ^'^f '  ''''^  ^^^P°^^^«  «^  ^^^  ^^^^  a  w'thra^ing  w' 
tne  flax,  and  those  of  the  frame  b  approaching  and  pushing  the  fibres  off  from  the 

T  w'-i^^'^  ^'l  °^^  '^"^^^^  ^y  the  descending  stroL  of  the  pointe. 
«/J  .u  "'^'^  ^f  P^^^^e^ved  that  as  the  combs  of  the  frame  a  and  h  respectively 

^:t.^Ti^V^^  however,  of  such  combs  or  heckles  acting  only  on  one  side  of  the  flax 
would  but  imperfectly  perform  the  operation  of  opening  its  fibres ;  it  is  therefore 
tZT^'  '?  ^'?''  ^l  accomplish  the  desired  object  in  the  most  eft^ctual  way  that 

strick  of  fl'!l'  '^  '''"!?7'  \r^''  ^^^^^^  ^'  ^^^i^*  *«  ^''  «"  opposite  sid^s^'f  the 
stnck  of  flax,  suspended  in  the  position  shown  in  the  figures.     The  cranks  of  the  two 

ffi't  l'*'i^^  <^o«^b-frames  or  heckles  a,  b,  and  c,  /are  connecS^i  by  a  pafr^f 

IctiaLd'at'ot:'  (Cl^'-  T"  "'-^^  ^^"''  '^^^^^^  "^^^^^'  ^y  -^i«^  theVec£es  are 
actuated  at  once,  the  two  sets  moving  m  opposite  directions,  but  with  similar  speeds 

Wp  wT^'^^f''^  heckling  of  the  material  will  go  on  in  the  way  shown  T  the 
figxire  last  indicated.     The  tow  being  collected  as  drawn  off  the  loVer  end  of  the 

anf  de  WyVon^^^^^  "'^'"'^  ^^'"^'^^  ^^  '^^^^  ^^^^^'  ^^^^  ''  '^  ^^^^^  ^J --^ 

use^'  fSZr^Jl^"""  ^/^'i  considerably  from  the  clamps  which  are  commonly 
used  1  shall  therefore  particularly  describe  their  construction,  before  showing  them 
m  operation.     Mgs.  694.  and  595.  are  views  of  the  clamp  in  tVo  different  pofition^ 

a  and  b  are  two  boards  united  together  by  a 
hinge  c,  at  top,  which  of  course  allows  them  to 
shut  and  open.  The  lower  parts,  forming  the 
jaws  of  the  clamps,  are  made  with  teeth  or  in- 
dentations, between  which  parts  the  ends  of 
the  flax  or  hemp  are  securely  held  when  the 
j/     rU^  .     ///  VV  clamps   are  brought   together;    d  d,  are  two 

\?Jrn    tly         ^^^    i  <^        pieces  projecting  from  the  board  6,  at  the  end 
\y       '     Y^  *^        of  each  of  which  is  an  eye  shown  by  dots,  and 

Jo  «  ^^,  VI  J  1  X       .  *^  *^®  ^^^^  ®^  ^^®  board  a,  (see /cr.  694.)  there 

w  a  double  aimed  lever  ^,  turning  upon  a  fixed  pin/,  which  lever  carries  two  circular 
wedges  g  g  These  wedges  pass  into  the  eyes  of  the  pieces  d  d,  when  the  clamps  are 
closed,  and  hold  them  fast.  There  is  a  segment  ratchet  A,  at  the  upper  part  of  the 
board  a,  which  turns  upon  a  stud  i,  and  is  pressed  downward  by  a  spring  k.  This 
ratchet  receives  the  end  of  the  lever  e,  and  consequently  keeps  the  circular  wedges 

^nTK'^l  t^t^  '^^i'S  ^""^^  .^^^  "^^^""P^  securely  together,  and  prevent  their  open- 
ing by  the  shaking  of  the  machine.  ^      o         .  r  f 

^Z^!'T ' -i^  Wfed  to  open  the  clamps,  the  ratchet  A,  must  be  raised,  and  the  lever  e 
pushed  aside  by  its  handle  I,  which  draws  the  circular  wedge/  from  the  eyes  of  the 
S  «f,!  A-  1^/"?/^®  ^^  *^^  ''^^'"P^  immediately  separate.  For  the  convenience 
^r.^i!!^®''^'^^.  ®  ?^^*^^r^  \°  ^^^  machines,  a  piece  of  sheet  iron  m  is  bent  at  right 
angles,  and  fastened  to  the  back  of  the  board  6,  as  seen  in  Jig.  695.,  forming  a  groove 
by  means  of  which  the  holders  are  enabled  to  slide  into  the  machine  and  hang  there. 


FLAX. 


'^47 


About  the  year  1840  an  improvement  took  place  in  the  excentric  circular,  by  which 
one  screw  of  the  holder  retained  two  stricks,  and  the  machines  made  wide  enough  to 
take  four  stricks,  and  also  a  movement  was  made  by  which  the  holder  was  carried  over 
two  cylinders,  so  that  each  side  of  the  strick  was  dressed  before  taking  out.  These 
improved  machines  had  a  very  extensive  sale,  as  wages  and  the  necessity  of  attention 
were  much  reduced  by  them.  Also  the  third  machine,  herein-before  described,  was  re- 
vived, having  a  rising  and  falling  motion  for  the  holder  support,  and  was  known  as  the 
Belfast  machine ;  and  similar  improvement  was  made  in  the  double  vertical  sheet  ma- 
chine. But,  as  none  of  these  sufficiently  dressed  the  line  for  the  finest  jarns,  a  machine 
called  the  "  crank  machine"  was  invented  for  that  purpose,  but  was  in  use  for  a  very  short 
time ;  its  object  was  more  to  perfect  the  dressing  after  the  excentric  machine  than  to  do 
the  whole  work  itself.  In  this  machine  the  flax  was  suspended,  and  then  stmck  simul- 
taneously on  each  side  by  heckles  having  an  al)rupt  angular  movement,  first  to  strike 
into,  and  then  draw  down  the  line,  in  order  to  draw  off  the  tow ;  the  work  was  begun 
at  the  end  and  gradually  advanced  up  to  the  holder. 

A,  A  {Jig.  596.)  arms  for  carrying  the  heckles;  b,  b, 
trough  or  slide  for  holders ;  c  o  sliding  piece  to  carry 
pivots  or  the  carriers  a,  a,  so  as  to  rise  and  fall  by  the 
motion  of  the  bell  crank  d  ;  e  connection  of  bell-crank 
D  with  excentric  f,  to  give  the  downward  stroke  when 
the  heckles  are  closed  upon  the  flax  by  the  action 
of  the  crank,  g,  connected  by  arm  i  with  the  carrier 
A ;  II  holder ;  k  connecting  rod  for  the  carriers  a,  a  ; 
L  and  M  pivots  for  the  respective  carriere  a,  a  ;  n,  n  the 
heckles. 

This  machine,  capable  of  doing  the  work  but  very 
slowly,  and  with  great  expense  of  heckles,  was  at- 
tempted to  be  improved  upon  by  another  made  of  two 
parallel  cylinders  constructed  of  a  series  of  bars  run- 
ning at  equal  speeds  in  contrary  directions.  Upon 
these  bars  were  fixed  the  heckles,  which  were  kept  in 
a  horizontal  position  during  their  entire  revolution,  by 
a  crank  at  the  end  of  each  bar,  guided  in  a  circular  path 
excentric  to  that  of  the  bars  themselves.  The  flax  sus- 
pended passed  with  a  rising  and  falling  motion  from 
one  emi  oi  the  machine  to  the  other,  each  succeeding  heckle  being  finer  than  its 
preceding. 

A  A  {Jig.  597.)  circular  discs  keyed  to  the  shafts  b,  b  ;    c,  c  circular  discs  running 
apon  the  excentric  bosses  D,  d  ;  e,  e  heckle  bars ;  f  slide  for  holders ;  o  holder. 
The  discs  a,  a  are  alike  at  each  end  of  the  machine,  and  have  suitable  bearings  to 


carry  the  heckle  shafts  e  by  thdr  round  necks  a,  a.  The  discs  c,  c  have  similar  and 
equal  number  of  bearings  to  carry  the  cranked  ends  of  the  heckle  bars  c,  and  arecarrie<i 
round  by  them  from  the  movement  communicated  to  a  a.    By  this  arrangement  th« 

5C2 


Ub 


FLAX. 


FLAX. 


749 


pins  of  the  heckle  are  always  in  the  position  shown,  and  penetrate  the  flax  at  right 
angles  to  its  length. 

As  all  the  preceding  machines  have  now  passed  into  oblivion,  it  may  be  as  well  to 
trace  the  reasons.  The  fault  of  the  first  was  the  great  attention  it  required  to  turn  the 
stricks  and  to  carry  them  by  hand  from  tool  to  tool ;  the  want  of  the  rising  and  falling 
motion  caused  the  heckles  to  strike  at  once  into  the  middle  of  the  flax,  thereby  reduc- 
ing the  yield  of  line,  and  rendering  the  tow  knotty  and  torn.  Though  some  of  these 
defects  were  remedied  in  the  second,  there  still  remained  the  transferring  of  the  flax, 
the  taking  out  of  the  tow,  to  be  performed  by  the  attendant,  and  the  motion  of  the  line 
through  air  was  objectionable.  In  the  third  another  step  was  gained,  that  of  taking 
out  the  tow ;  but,  for  the  want  of  the  rising  and  falling,  the  work  was  too  abruptly 
torn  into.  The  fourth  was  suitable  but  for  short  flax ;  it  was  very  expensive  on  account 
of  the  liability  of  the  holders  falling  upon  the  heckles,  and  the  turning  and  transferring 
the  flax  by  hand,  even  when  afterwards  these  expenses  were  slightly  reduced  by  the 
improvement  above  alluded  to.  The  fifth,  never  coming  out  of  the  workshop,  waa 
perhaps  found  deficient  for  want  of  the  rising  and  falling,  which,  though  partially  obviat- 
ed by  the  cylinder  end  being  conical,  might,  even  by  this  mode  of  palliation,  lead  to 
further  difficulties  of  a  practical  nature,  aud  by  the  turning  movement  being  continued,  a 
further  inconvenience  would  no  doubt  have  been  found  in  the  edges  of  the  stricks  being 
as  long  exposed  to  the  heckles  as  the  sides.  The  sixth,  for  a  long  time  popular,  was 
found,  by  heckling  both  sides  at  the  same  time,  to  tear  away  the  flax,  and  from  the  im- 
possibility of  getting  the  pins  to  work  near  up  to  the  holder,  a  long  shift  was  re- 
quired,— another  reason  by  which  the  yield  was  reduced.  Seventh  ;  Evans'  machine, 
though  only  put  up  for  experiment  in  this  country,  has  been  more  extensively  tried 
abroad ;  but  it  made  tow  so  knotty  for  want  of  a  clear  stroke  through,  that  it  was 
immediately,  and  is  now  perhaps  entirely,  abandoned  everywhere.  Eighth  ;  the  crank 
machine  was  very  troublesome  and  expensive,  and  could  hardly  ever  be  said  to  have  got 
beyond  its  experimental  state.  It  is  now  altogether  laid  aside.  Ninth ;  the  double 
cylinder  machine  answers  well  for  very  short  line,  but,  for  much  the  same  reason  as 
the  above,  makes  but  indiflferent  tow,  and  its  use  is  now  nearly  discontinued. 

Besides  the  above  there  have  been  several  others  patented ;  some  have  never  been 
wholly  constructed,  and  others  never  been  used :  neither  appear  to  have  suggested  any 
principles  or  modes  of  action  capable  of  being  modified  into  a  useful  or  practical  state. 

We  now  come  to  explain  those  heckling  machines  by  which  the  flax-spinning  trade 
is  at  present  actually  carried  on,  in  which  it  will  be  seen  that  the  best  parts  of  all  the 
preceding  are  combined,  so  as  to  form  machines  of  the  utmost  efficiency,  and  capable 
of  working  with  a  closer  approximation  to  the  utmost  degree  of  economy. 

The  first  in  order  is  the  transverse  sheet  machine.  This  machine  is  on  the  same 
principle  as  the  third,  above  described,  having  a  horizontal  sheet  to  each  heckle,  but 
each  running  in  an  opposite  direction,  and  a  rising  and  falling  trough,  along  which  the 
holders  are  impelled  from  one  end  of  the  machine  to  the  other.  It  is  so  arranged,  that 
when  one  side  of  the  strick  is  heckled  the  slide  or  trough  rises,  and  the  holder  being 


K 


i 


suddenly  pushed  forward,  the  flax  thereto  attached  comes  m  contact  with  the  next 
sheet  running  in  a  reverse  direction,  and  has  thereby  ita  other  side  dressed.  This  is 
repeated  over  as  many  tools  as  may  be  desired,  generally  three,  but  sometimes  four. 
For  the  better  elucidation  refer  to  fig.  698.,  section  of  machine. 

A  A  f  /?(/  698  )  frame  ;  b  b  heckle  bearing  sheet  running  m  the  direction  of  the  arrow ; 
c  c  another  heckle  sheet  running  in  the  opposite  direction;  d  holder,  a^d  its  rising  and 
falHng  support  in  the  form  of  a  trough,  along  which  it  shdes  from  one  end  of  the  machine 
to  the  other :  k  chain  to  which  is  attached  the  balance  weight  of  slides  <fec. ;  f,  g  h  the 
carriers  of  the  sheets,  of  which  f  and  h  are  keyed  to  their  respective  shafts,  as  it  is  by 
them  the  sheets  b,  b  and  c,  c  are  driven,  and  drive  their  carriers  g  oose  upon  the  shafL 

It  is  somewhat  objectionable  in  the  above  machine,  that  the  holder  shde  has  to  rise 
to  a  great  height,  so  as  to  take  the  ends  completely  off  the  tool,  otherwise  the  strick 
is  liable  to  be  crossed  by  one  side  being  for  the  moment  pulled  in  one  direction,  and 
the  other  in  a  contrary  ;  and  also  that  the  tow  and  waste  might  be  apt  to  coUect  in 
the  spaces  where  the  sheets  cross  each  other,  and  thus  occasion  derangement 

The  following  known  as  Baxter's  self-acting  cylmder  and  sheet  machmes  (these 
appellations  being  given  accordingly  as  cylinders  or  endless  sheets  were  employed  to 
carry  the  heckles),  of  which  the  distinctive  feature  is  turnmg  the  holders,  avoids  this 

"^The  holders*  from  which  the  flax  is  suspended  are  supported  above  the  centre  of  the 
cylinder  (when  a  cylinder  is  employed),  or  of  the  rotatory  carrier  of  the  endless  sheet, 
when  that  method  of  applying  the  heckles  is  adopted;  but  instead  of  their  supporting 
slide  or  trough  being  in  one  continuous  piece,  it  is  divided,  accordmg  as  the  machine  is 
intended  for  3  or  4  gradations  of  tools,  into  6  or  8  divisions,  each  equal  to  the  length  of 
the  holder     Of  these  half  the  number  always  remain  in  a  direction  parallel  to  the  axis 
of  the  cylinder,  while  the  others,  placed  between  or  alternately  with  them,  are  connected 
together  by  gearing,  so  as  to  turn  simultaneously  in  a  horizontal  direction,  and  the  whole 
arl  combined  to  approach  and  recede  to  and  from  the  heckles  together  by  a  falling  and 
rising  motion.    The  brushes,  card-clothed  cylinder,  and  comb,  when  employed  are 
similarly  combmed  for  clearing  and  delivering  the  tow  as  those  already  described  for 
the  same  purpose  in  the  excentrlc  circular  machine ;  but  m  general  for  the  sheet  machmes 
a  simple  faller  is  found  sufficient.  Thus,  the  flax  mtroduced  mto  the  first  division  when 
the  slide  is  at  the  top  of  its  course,  is  dressed  durmg  its  descent,  and     dwell    upon 
the  first  half  length  of  the  first  tool;  on  being  risen  it  is  pushed  forward  by  mecha- 
nism  into  the  next  division  of  the  slide,  which  then  by  turning  half  round,  or  end  for 
end,  presents  the  second  side  of  the  strick  to  the  second  half  of  the  same  tool,  upon  which 
it  thus  becomes  dressed,  as  was  the  first :  on  again  rising,  the  flax  is  pushed  into  the  third 
division  of  the  slide,  which  presents  the  side  of  the  strick  that  was  second  on  the  first 
tool  to  be  first  exposed  to  the  action  of  the  second,  and  thus,  at  each  nse  is  the  flax 
advanced  towards  the  finer  tools,  turning  at  each  alternate  advance,  till  the  reqmred 
number  of  tools  is  passed  over.    This  is  the  construction  generally  employed,  but  it  is 
sometimes  necessary  that  each  holder  turns  m  its  place,  thus  heckling  each  side  of  the 
strick  on  the  same  identical  heckle  ;  thus  the  flax  is  more  worked,  for  it  is  exposed  to 
6  or  8  gradations  of  tools,  instead  of  3  or  4  by  the  other  method,  but  a  machine  upon 
the  foraier  will  do  nearly  double  the  weight  of  flax  than  upon  the  latter  mode  of  work- 
ine     Though  the  progress  but  of  one  holder  has  here  been  traced,  it  must  be  under- 
stood that  there  are  necessarily  6  or  8  in  simultaneous  operation    according  to  the 
description  of  machine;  for  the  propelling  motion  being  at  one  end  requires  the  full 
complement  of  holders  to  push  one  another  forward.    This  machme  and  the  Jast  per- 
form pretty  nearly  the  same  quantity  of  work,  which,  with  6  or  7  boys,  amounts  to  about 
1  cwt  per  hour,  and  are  applicable  for  long  flax,  and  for  cut  as  far  as  60  or  70  leas ; 
the  latter  is  sometimes  used  with  4  gradations  of  tools  as  far  as  1 00  leas.     The  con- 
struction of  these  machines,  whether  cylmder  or  shee^  is  bo  smai^ar,  that  the  same  le  ters 
and  figures  refer  to  the  same  parts  of  each.    Figs.  699  and  600.  front  and  profile  views 
of  cylinder  machine,  and  Figs.  601.  and  602  front  and  profile  of  sheet  machme 

A  i  general  framing ;  b  driving  pulley  on  the  shaft  of  brush  roller ;  c  c  mam  cylinder 
D  D  brush  roller ;  b  e  card-covered  roler ;  f,  f  rails  constituting  part  of  the  falhng  and 
rising  head  and  to  which  are  fixed  the  movable  parts  for  turhmg  the  holder;  go  the 
first  part  of  the  slides  along  which  the  holders  pass ;  h,  h  the  alternate  turnmg  parts ;  i^  i 
the  holders,  those  No.  1.  a?e  with  the  side  as  put  ii^  and  those  No.  2.  are  when  turned; 
K^KK  supports  from  the  rail  f  to  fixed  parts  of  sUdes  g  ;  l  the  supports  with  pivots  for 
Sir  turniSe  parts  of  the  slide  h  h  ;  to  these  pivots  are  fixed  respectively  the  wheels 
Ilo  q  •  the  intermediate  wheels  n,  p  being  loose  upon  their  axis,  serve  tx»  connect  the  mo- 
don  of  the  series  •  e  lever  and  lock  to  retain  the  wheels  fixed  during  the  fall  and  r^e  ;  s 
luDDort  for  the  lever  r  ;  t  support  for  the  pendulous  lever  u,  which  by  the  pusher  v  drives 
SCldSs  foi^ard  when  introduced  into^he  slide ;  w  slide  inclined  to  conduct  the  hold- 
Ss  on  a  table;  x  x  doffing  comb  shaft;  y  connector  between  the  rails  f  and  balance 
wdght  lever  z;  a  a  excentric  to  give  the  up  and  down  motion  to  moving  head; 


w 


750 


FLAX. 


FLAX. 


761 


^ 


^ 


b  friction  bowl ;  c  balanct  weight :  this  arrangement  of  connector,  lever  weieht  and 
excentncs  are  the  same  at  each  end  of  the  machine,  as  the  shaft  d,  upon  which  the  ex 
centnesare  fixed,  extends  the  whole  length  of  the  machine;  e,/,  q  train  of  wheels  and 
puuons  to  reduce  the  speed  of  cylinder  shaft  c  to  the  excentric  shaft  d-  Ki  wheel 
and  pmions  to  drive  the  excentric  by  which  the  doffing  comb  is  moved  by  the  con 


caused  by  the  rise  and  fall  of  the  head.  The  followmg  figures  show  the  form  of 
the  "sheet"  machines,  but  which  do  not,  from  their  similarity  of  P"°^jP^«  *"^^J^^ 
Btmction  to  the  foregoing,  require  a  detailed  description ;  as  the  only  diflFerences  are 


necting  rod  l;m,n,o,p,g  trains  of  wheels  from  driving  pulley  b  to  cylinder  c  and  card 
roUer  e;  the  propulsion  of  the  holders  is  caused  by  the  radial  movement  of  the  lever  z, 


762 


FLAX. 


FLAX. 


76i 


that  a  sheet  is  used  to  carry  the  heckles  instead  of  a  cylinder,  and  doffer  bars  for 
knocking  out  the  tow  instead  of  the  more  complicated  arrangement  of  brush,  comb,  <fec 

Those  machines  that  are  now  employed  for  finest  work  are  called  Mar&den'i  huer 
Meeting  machine,  and  combined  intersecting. 

The  intersecting  machine  is  so  called  from  the  peculiarity  of  its  construction,  being 
somewhat  similar  in  principle  to  that  already  described,  of  two  cylinders  of  heckles 
carried  on  cranked  bars,  but  instead  of  their  being  so  closely  placed  together,  there  are 
but  six,  eight,  or  more  bars  bearing  the  heckles,  forming  as  it  were  a  sort  of  a  skeleton 
cylinder,  of  which  there  are  two,  parallel  to  each  other  in  each  machine :  the  flax 
passes  along  the  machine  between  these  two  cyhnders,  and  is  struck  by  their  heckles 
alternately,  and  in  successive  order  on  its  opposite  side.  MarsderCs  combined  inter- 
secting machine  has  in  addition  to  these  cylinders  a  pair  of  sheets  of  heckles,  by  which 
the  first  tool  work  is  performed  previously  to  the  flax  arriving  at  the  intersecting 
cylinders,  and  the  flax  is  rather  more  severely  heckled.  In  both  of  these  machines  the 
holder  slide  is  provided  with  a  rising  and  falling  motion,  as  being  absolutely  necessary  for 
the  production  of  good  work :  these  machines  penetrate  the  flax  better  than  the  cylinder, 
as  from  its  position  between  the  heckles,  the  flax  is  rigorously  exposed  to  their  eflFect, 
but  the  tow  thereby  produced  is  rather  more  lumpy  and  uneven,  and  is,  therefore,  con- 
sidered inferior  to  that  from  the  cylinder  machines,  see  Jigs.  603.  604.  605.  of  com- 
bined intersecting  machine. 

Mg.  603.  end  \ievr;Jig.  604.  side  view ;  Jig.  605.  sheets  ;/5r.  606.  holder ;  a  a  a  fram- 
ing ;  B  B  holder  trough  or  slide  ;  c  jointed  rod,  having  a  horiiiontal  motion  to  push  forward 
the  holders  by  the  clicks  a,  a,  which  catch  the  holders  in  one  direction  only ;  d  pendulous 


ever  receiving  a  reciprocity  motion  from  the  radial  arm  k,  at  the  rising  and  falliii(; 
of  the  sliding  head ;  f  support  for  the  pendulous  lever  d  ;  g,  g  carriers  of  the  heckle 
bearing  sheets,  h,  h  ;  i,  i  heckles  fixed  to  the  sheets  or  straps  h  ;  k  k  card-clothed  cylindw 
for  receiving  the  tow  from  the  brush  cylinder ;  l  doflSng  comb ;  m  brush  cylinder ; 
N  N,  o  o  slide  shafts,  upon  which  are  ke3^ed  the  carrier  arms  p,  p  of  the  intersecting 
heckle  bars  q  q:  R.  R  crank  arms  fixed  to  the  heckle  bars,  and  guided  by  their  extre 
mities  in  the  slides  o,  o,  by  which  the  peculiar  position  of  the  heckles  is  maintained ; 
t?,  connector  tetween  sliding  head  and  lifter  excentric,  or  cam;  t,  u  the  friction  bowl 
for  pulling  downwards  the  slide  head,  to  which  a  tendency  is  given  to  rise  by  balance 
weights,  not  necessary  to  be  shown ;  v  wheel  commanding  excentric  to  give  the  oscil- 
lations to  the  doflSng  combs. 

In  all  heckling  machines,  whether  those  of  sheets  or  cylinders  running  m  opposit* 
directions,  and  not  therefore  requiring  the  turning  motion  for  the  holder.or  those  with  the 
turning  motion,  and  having  therefore  but  one  sheet  or  cylinder ;  or  agAin  those  called 
the  intersecting  and  combined  intersecting,  the  hand  labour  required,  and  the  number 
of  holders  or  work  turned  out  in  a  given  time,  are  nearly  the  sarne  for  similar  degre£« 
of  dressing,  and  all  these  machines  are  provided  with  change  pinion^  to  mcrease  or 
diminish  the  quantity  of  heckling  in  any  required  degree. 

The  hand  labour  consists,  first,  of  dividing  the  flax  into  stricks,  for  long  flax,  of  4  or 
5  ozs.  each,  and  for  cut,  1^  to  2  ozs.  Then  screwing  these  into  the  holders,  and  whea 
one  end  is  worked,  taking  out  the  holders,  performing  the  "shift/'  and  replacing  them. 

Vol.  L  6  D 


7«4 


FLAX. 


606 


by  which  It  18  evident  that  the  manual  work  is  reduced  to  nearly  the  lowest  powible 
point;  for  the  taking  out  the  holder  and  performing  the  shift  are  the  only  opTatiorthat 
can  by  po88ibihty  be  done  mechanically ;  and  it  is  desirable  that  this  should  be  so  effeetei 
not  only  with  a  view  of  saving  the  expense  in  wages,  but  to  avoid  the  waste  and  en 
tangWnt,  and  consequent  reduction  of  yield,  to  which  by  handling  the  flax  is  exposed 

;^Lh  f-'*°'fVh°'^  ''i?"''  *^  1*^^  f  ^?\*  ^^^^^  «"  °^^<i  f«r  reliance  upon  the  care 
and  attention  of  the  workers  employed.  A  holder  with  this  intention  was  patented  about 
three  years  since,  which,  from  its  novelty  of  construction,  deserves  a  record  for  thoTh 

opposed  alike  to  this  as  to  all  other  innovations.  I'ftyuuices 

Previously,  however,  to  entering  upon  a  description  of  this  holder,  it  will  be  neces- 

jaij,  in  order  to  make  our  account  of  heckling  machines  now  actually  in  use  comp'X 

fn  Fn.lJ^r.r''  ?:-  ^^^ri^""^''  wecamgue  ,y,tem  Busk,  from  the  name  of  ite  inventor, 
:Se!5f  tentrit^^^^^^  *""'""^^  ^^^^"*"^  ^^^  doublecylinder  machines hav^ 
Flax  A«cA/^,  called  Peignetise  Mecanique,  on  the  system  of  Bmk,  as  dAcribed  in  a 
Rrench  jyubhcaU<m  vndustriel^lt  has  been  found  in  practice  that  to  obfain  the  beat 
result-  It  IS  absolutely  necessary  to  attack  the  flax  by  the  end  of  the  strick.  and  to 

.i^L^ltT  "^r '"^  -"^V^"'  ^^  *^'  P^^^^'  ^  *^^  invention  of  Mr.  Busk,  the  author 
oJrZ?^    •''!?   TT  flf,^-«P/«ning  machines,  unites  in  itself  all  the  different  poinU 

tr^f^^ZJ'^'''^^^^'7^^^^''\^''^  ''^^\%  inconveniences  of  the  rival  systems.^  The 
force  requisite  to  dnve  it  is  hardly  one-half  of  a  horse-power ;  is  capabli  of  heckling 

?4  S  ?T  ^^''^}^^  ^''^^  ^'}>''''^  '^^'■^^^^  of  hanS-work,  about  500  kilogramm^ 

2..^?^/'  ^^'^''l  ^'^J^'l'  according  to  the  nature  of  the  flax.     It  is  applied  with 
equal  advantage  to  the  long  or  the  cut  line.    It  may  be  conducted  or  miiaged  by 


FLAX 


iiSk 


4  or  6  children  merely,  employed  to  screw  and  unscrew  the  clamps  (presses),  an  easy 

""^S^wrt^^ton  of  the  machiM,^Fig.  607.  longitudinal  elevation  of  the  mechanical 
heckle. 


^g.  608.     Elevation  of  one  of  the  sides,  or  as  seen  from  the  end. 


i, 


K.  Large  cylinder,  in  whose  circumference  the  heckle  teeth  are  fixed.     The  distanea 
between  the  points  varies  according  to  the  perfection  which  is  desired  in  the  heckling^ 

5D2 


766 


FLAX. 


FLAX. 


757 


I    :| 


It 


and  the  <juality  of  the  flax.     The  length  of  the  cylinder  (2  metres  40  cents)  admits  of 
multiplying  the  heckle  points,  and  varj-ing  their  distances.  ^ 

B.  SmaU  plates  (pWrf^ea)  fixed  between  the  heckles,  to  determine  the  denth 

^rraTg^dafp^leSe^  ^'*"  '^'^  '"  ^^^^'^^-  ^^'^  ^'^'^^  ^^^  — ^^^  -  -  t?be 
a  Carriage  bearing  the  pincers  in  which  the  stricks  are  fixed,  d.  TTpright  arbours 
on  which  the  carriage  rises  and  falls  by  means  of  the  sockets  e,  fixed  to  tL  carrL^to 
machii^  Tf.f  ^'^^.^^^^^^t  effected  ty  aid  of  an  excentric  placed  on  the  side  of  the 
Znnlhnn/ n  V'T*??  ''  balanced  by  counter  weights.  One  of  its  sides  is  furnished 
throughout  all  its  length  with  a  cast-iron  rack,  in  which  all  the  pincer  bearers  (wh  cl, 
are  toothed  on  their  upper  part)  wort.  ^  "carers  ^wnicii 

F.  The  pincer  carriers,  whose  upper  part  is  a  toothed  wheel,  and  whose  lower  part 
terminates  m  hooks  {crochets)  that  receive  the  pincers  in  wood.  Rigi^bai  connect 
the  pmcere  m  the  upper  part;  so  that  thev  all  work  at  the  same  time 

6.   Wooden  pincers  clasping  the  stricks  of  flax  by  means  of  a  screw 
l.pntll'l  •  .     ^'i^  brushes  for  removing  the  tow,  which  had  been  retained  by  the 
heckle  points,  and  carrying  them  to  the  cylinder  i,  furnished  with  cards.  ^ 

J.  llecke  which  deposits  its  tow  into  a  box  placed  to  receive  it     All  the  pincers  o 

ina^il'^^''*''^-^^'?!^^^  *'"  ^^'^  ^^  '^'  ^^^^  ^^  t^^  P^^«<^-  t,earers.      On  set  .ng The 
machine  m  motion,  the  carriage  g,  commanded  by  an  excentric  intended  to  give  it  a  pro- 
gressive velocity,  calculated  proportionally  to  the  thickness  of  the  strick  descends  and 
puta  the  flax  in  contact  with  the  heckle  teeth  fixed  romid  the  large  cySer  a  actuated 
by  a  continuous  movement     When  this  operation  is  terminated;  all  the  stricks  of  flax 
submitted  to  the  action  of  the  cylinder  having  been  heckled  on  ine  s  de,  the  excentrS 
which  had  caused  the  carriage  to  descend,  makes  it  mount  again ;  at  whtch  moment  the 
other  excentric  acts  destined  to  communicate  to  all  the  pincers  the  horizonX'otion - 
fW  f^  ^A     P^^^«^,  bearers  are  m  toothed  geer  with  the  carriage,  the  consequence  is 
that  m  advancing  the  pincer  bearers  pivot  on  themselves,  so  that  the  carriage  desceixd- 
mganew,  pesents  to  the  action  of  the  heckle  points  the  other  face  of  the  flax. 
thf^'LTT  J"?  ^f^g  *^,^  repeated  even  to  the  extremity  of  the  carriage,  works  on 
the  flax  by  heckle  teeth  closer  and  closer  together.     When  thev  hnve  arrived  at  this 
pomt  the  pincer  earners  continue  to  advance,  passing  by  thc^ijuck  of  the  machine- 
Dut  this  side  of  the  carriage  having  no  rackwork,  the  pincer  bearers  do  not  pivot  (turn 
round)  and  proceed  without  changing  position,   at  which  point  the  heckled  flax  is 
replaced  by  the  unheckled. 

The  tow  is  disengaged  by  the  brusli-cylinder,   and  transmitted  to  the  cylinder 
mounted  with  cards:  a  heckle  then  detaches  it  and  drops  it  into  a  box. 

Such  was  the  state  of  heckling  machines  when  the  holder  above  aUuded  to  was  first 
ada  "  A  *  ^*^^  ^'   ^^^^  applied  to  this  machine,  for  which  it  is  peculiarly 

All  the  holders  that  have  hitherto  been  used  are  similar  to  those  described  at  the 
beginning  of  the  article,  consisting  of  two  clamps  of  wood  or  iron  pressed  together  by 
screws,  except  in  Evans's  machme,  where  an  inclined  plane  was  used  for  that  purpose 
But  the  holders  now  referred  to  are  on  an  entirely  different  principle :  the  holding  pres- 
sure being  produced  by  the  eff'ect  of  leverage  of  the  clamps  or  jaws  themselves  which 
are  for  this  reason,  and  also  for  better  supporting  the  end  of  flax  out  of  operatioi  made 
irom  7  to  9  inches  broad ;  and  while  one  of  their  edges  are  hooked  or  fastened  together 
by  a  pair  of  double-acting  hinges,  similar  to  those  used  at  the  bottom  of  turnpike  gates 
the  others  are  held  together  by  a  clasp,  and  thus  the  flax  is  very  firmly  grasped  or  held 
■\^t  P^^^^"'*^  *^  ^be  joint  or  hinge,  and  the  end  of  the  flax  not  exposed  to  the  heckle 
IS  held  vertical  and  straight  by  the  breadth  of  the  clamps.     These  holders  do  not  slide 
of  themselves  along  a  trough,  as  do  the  other  description,  but  there  are  "carriers"  for 
them  attached  to  the  sliding  and  turning  apparatus,  by  which  they  are  carried  forward 
and  turned  as  desired.    These  carriers  are  so  constructed  as  to  retain  the  holder  by  one 
of  its  clamps  or  jaws  always  vertical,  but  leaves  the  other  free  to  fold  from  one  side  to 
the  other;  when  this  folding  takes  place,  which  is  during  the  dwell  of  the  other  holders 
upon  the  heckles,  that  end  of  the  flax  which  was  contained  between  the  clamp  becomes 
liberated,  and  the  previously  pendant  one  is  lapped  up  and  enclosed  between  them 
when  the  rise  of  the  head  taking  place,  the  catch  replaces  itself,  and  the  holder  is  ear- 
ned forward  to  return  along  the  second  cylinder  of  the  machine,  and  ultimately  arrives 
at  the  place  where  it  was  first  put  in  with  the  line  completely  dressed.     As  all  these 
movements  are  performed  automatically  by  the  machine  itself  the  whole  of  the  wages 
neeessanr,  when  the  other  holders  are  used,  for  taking  out,  and  screwing  and  unscrrw- 
mg,  and  replacing  them,  amounting  to  nearly  half  of  the  whole  expense,  is  6u\.,l 
besides  much  indirect  trouble  and  confusion.  * 

^  1»  ^  2,  jaws  of  the  holder ;  b  b  carriage  or  frame  for  supporting  the  holder ;  c  o,  a 
toothed  wheel,  having  a  groove  on  one  side  to  allow  it  to  be  carried  by  th«  raila  of  th« 


moving  head  of  the  machine,  of  which /^.  609,  is  apian  or  bird's-eye  view ;  d,  d,  links  or 
bars  connecting  the  series  of  wheels  c,  g    These  wheels  are  of  such  a  diameter,  that 


M 


610 


611 


k 


-when  propelled  from  1  to  2,  they  will  at  the  same  time  make  one  exact  half  revo- 
lution ;  and  thus  the  holder  attached  to  each  presents  its  opposite  side  to  the  heckl^ 
at  each  advance  similar  to  other  machines.  To  cause  this  half  revolution,  the  teeth 
of  the  wheels  c,  c  engage  those  of  the  racks  e,  e  and  f,  f  ;  but  the  slides  are  so  made  as 
to  maintain  the  wheels  in  one  position  from  e  to  f  at  one  end  of  the  machine,  and  from 
F  to  E  at  the  other;  gh  the  position  and  place  where  the  holder  stands  to  be  shifted; 
and  I K  when  first  put  in  or  to  be  taken  out  of  the  machine ;  l  m,  axis  of  heckle  cylinder 
to  dress  the  flax  after  "shifting;"  therefore  its  coarser  tools  are  at  end  m;  no  axis  of 
cyhnder  for  dressing  the  root  ends;  therefore,  its  coarser  tools  are  at  end  n.  The 
arrows  show  the  direction  of  movement  of  all  these  parts.  The  mode  of  action  of  the 
bolder  is  as  follows.  The  jaw  a  2  is  first  laid  upon  a  table,  and  the  flax  placed  upon 
it,  when  the  jaw  a  1  is  caused  to  engage  the  pin  3,  which  are  similar  at  each  end  of 
the  holder,  when  it  is  folded  down  upon  a  2,  and  the  catch  fixed  to  2  engages  the  rack 
fixed  to  A  2  at  5,  and  the  whole  is  firmly  combined  together  and  placed  into  the  carrier, 
and  maintained  by  the  pins  projecting  for  the  purpose  from  a  1  entering  into  vertical 
grooves  in  the  carrier,  when,  having  passed  over  the  heckles  on  cylinder  n  o,  it  ultimately 
arrives  at  o  ii,  when,  during  the  descent  of  the  sliding  head,  the  lever  attached  to  the 
catch  5  strikes  against  a  fixed  point,  and  is  thereby  lifted  out  of  the  rack,  thus  leaving 
at  liberty  the  jaw  a  2  to  turn.  This  is  effected  by  a  projecting  pin  2,  being  actuated 
by  a  crank  having  a  suitable  intermitting  motion,  which  carnes  it  in  the  direction  of 
the  dotted  line,  while  the  hinge  pins  quit  recess  8,  and  the  other  enters  the  recess  4^ 
and  the  rack  engages  the  catch  opposite  to  the  one  it  has  quitted ;  and  thus  the  shift 
is  completed  with  a  length  equal  to  the  thickness  of  the  holder  at  3,  4. 

The  cutting  of  flax,  which  is  done  in  order  the  better  to  select  and  separate  its 
various  qualities,  is  an  operation  of  some  delicacy,  and  requires  a  peculiar  machine 
for  the  purpose,  which,  though  not  complicated,  requires  great  nicety  m  its  making 
and  arrangement;  for  the  flax  must  not  be  cut  too  abruptly,  but  be  gradually  reduced 
to  a  taper  and  somewhat  natural  end.  The  cutting  should  be  done  before  the  flax  is 
heckled.  The  machine  for  the  purpose  consists  of  a  species  of  circular  saw  about  20 
in.  diameter ;  but,  instead  of  a  single  blade,  is  constructed  of  3  or  4  plates  of  steel, 
each  about  i  in.  thick,  and  having  angular  projections  from  their  circumference.  This 
revolves  at  a  considerable  velocity,  while  the  flax  firmly  grasped  in  each  hand  by  its 
ends,  is  still  further  held  and  slowly  carried  against  the  saw  by  two  pair  of  grooved 
pulleys  pressed  together  by  a  considerable  weight  It  is  thus  partly  sawn  and  partly 
broken  through.  Flax  may  be  cut  into  2,  3,  and  sometimes  4  divisions :  and  some- 
times the  dead  harsh  fibres  that  are  frequently  found  at  each  of  its  ends  only  are  cut 
off  and  used  as  tow ;  but  more  generally  the  diflferent  portions  are  heckled  and  usea 
for  the  purposes  they  are  sorted  for.  ,       .  -i.  :• 

Description  of  flax  cutting  machine,  {figs.  612,  613.)  a  a,  framing  ;  b,  the  grooved 
pulleys  for  holding  and  carrying  the  flax;  c  c,  the  driving  pulley;  d,  saw  or  cutter; 


768 


FLAX. 


FLAX 


159 


E,  F,  wheels  for  geonng  together  the  pair  of  holding  puUeys;  g,  n,  i,  k,  pinions  and 
wheels  ior  producing  the  proper  relative  speeds  between  the  cutter  and  pulleys;  l, 
weight,  which  by  levers  m  and  n,  causes  the  pressure  of  the  holding  pulleys. 

4th.  Preparing.— By  this  term  is  understood  those  preliminary  operations  through 
which  both  line  and  tow  must  pass  after  the  heckling  and  before  the  spinning  process. 

The  mechanism  and  modes  of  proceeding  for  this  purpose,  which  consist  of  repeated 
drawings,  are  similar  for  "  long "  line  or  *'cut;"  though  the  dimensions  and  fineness 
of  the  machinery  must  be  made  suitable  for  their  various  lengths  and  qualities.  But 
m  the  preparation  of  tow  a  peculiar  additional  operation  is  demanded,  as  a  conse 
^uence  of  the  diflferent  state  of  the  fibres  of  which  the  material  is  composed;  this  opera- 
tion, termed  "  carding,"  has  for  object  to  bring  the  highly  irregular  and  entangled 
mass  into  a  somewhat  more  homogeneous  and  uniform  state,  previously  to  its  being 
afterwards  drawn  and  ecj^ualised  in  a  manner  similar  to  line. 

In  the  preparation  of  hne  the  first  operation  is  called  "spreading,"  and  the  machine 
employed  a  "spreader,"  or  first  drawing:  those  subsequently  are  the  second  and  third 
"drawings"  (sometimes  a  fourth  is  used),  and  lastly  the  "roving."  It  is  upon  the 
spreader  that  the  separate  stricks  of  line  are  first  combined  and  drawn  into  long 
uniform  bands  or  ribbons,  called  "slivers,"  of  determinate  lengths.  This  is  eflfected 
by  subdividing  the  stricks  into  two  or  three  portions,  and  then  placing  them  consecu- 
tively slightly  elongated  ;  and  overlaying  each  other  about  fths  of  their  length  upon 
and  in  the  direction  of  an  endless  creeping  sheet  or  apron.  The  machines  are  generally 
made  with  two  of  these  creeping  sheets  or  aprons,  and  upon  each  sheet  are  thus  laid  two 
distinct  lines  of  stricks ;  each  of  which  forms  a  thick  uniform  body  of  line,  capable 
of  being  maintained  to  an  indefinite  length.  These  endless  creeping  sheets  supply 
continuously  another  part  of  the  machine,  where  the  body  of  "  line  "  is  drawn  out 
to  between  20  and  60  times  its  original  length,  according  to  whether  it  is  composed 
of  cut  or  long  flax.  This  part  of  the  machine  comprises  a  pair  of  holding  or  back 
rollers ;  an  endless  succession  of  bars  called  fallers,  bearing  combs  of  closely  ranged 
steel  pins,  through  which  the  slivers  are  drawn ;  a  pair  of  drawing  rollers ;  an  ar- 
rangement of  diagonal  or  doubling  bars  ;  and  a  pair  of  delivering  rollei-s  •  'is  gene- 
rally termed  the  "gill  frame,"  or  "gill  head,"  probably  from  the  French  word 
"aiguilles"  (needles),  as  descriptive  of  the  combs,  and  to  distinguish  this  machine 
from  those  formerly  used  for  the  same  purpose,  which  simply  consisted  of  a  series  of 
rollers  under  and  over  which  the  line  was  passed. 

The  following  figures  614,  615,  show  the  outline  of  the  present  most  approved  gill 
spreader  or  first  drawing. 

A  A,  general  frame  of  the  machine;  b,  driving  pulleys;  c,  auxiliary  frame  for  endless 
sheets ;  d,  n,  d,  d,  rollers  for  carrying  the  endless  sheets  or  aprons ;  e,  e,  conductors  to  guide 
and  slightly  condense  the  four  bodies  or  slivers  of  line ;  f,  can  for  receiving  the  sliver ;  o, 
lever  for  weight  on  front  or  drawing  roller;  h,  lever  for  weight  on  back  roller;  k,  de- 
hvenng  roller  shaft,  spring  and  bell,  which,  by  the  intervention  of  geering  between 
it  and  the  front  roller,  is  caused  to  ring  when  any  desired  length  of  sliver  is  delivered. 

a  0,  the  iron  drawing  roller  or  boss ;  6  6  6,  the  wooden  or  pressing  roller,  by  the  pressure 


of  which  upon  a  a  the  sliver  is  held  during  the  greater  velocity  of  these  rollers  over 
thJofV^he  holding  or  back  rollers  elongate  in  exact  proportion  of  its  augmentation; 
tt  hling^^^^^^^^^^  like  manner  pressJ  against  another  in  order  U>  assist  the  "  gills- 

,TXS  the  fibres  •  k,  L  hooked  rods  to  connect  the  weighted  lever  A  with  the  hold- 
L  ron^c^and  by  S;  preLsu  thus  caused  insure  its  effect;  dd,  the  sheet  or  surface 
7"  cills"  compose^d  of  separate  bars,  as  seen  at^^.  614*  616.* ;  e,  rubber  or  cleaner  of 
Dressing  rolle^n,  /.  conductors  to  contract  laterally  the  sliver  at  the  moment  of  draw- 
FnTaXte  of  metaThaving  diagonal  openings  at  an  angle  of  45°  (this  plate  is  sometimes 
caUeSthf"doS>lkg  bars,"  haling  been  first  made  of  separate  S?""^)  ^^  ^^T'^-!?^ 
couree  of  the  s?i^er,  in  order  to  enable  it  to  be  turned  in  a  rectangolar  direction  and  gmdcd 
J^  the  delivering  rollers  h,h ;  this  direction  of  the  sliver  is  more  distinctly  seen  at  Jig.  6lU 
i  hanger  or  connector  of  pressing  roller  6  to  its  weight  lever  c ;  /  /,  the  screws  or  woroi 
riiaft  for  earJp^ng  the  gill  bar  <WT  mm,  the  shaft  with  bevel  wheels  by  which  the  soreira 


Al  ODDOsite  sides  of  the  frame  are  caused  to  move  simultaneously;  n^n  pinions  for  coo- 
"ecZg  t  le  upper  and  lower  spirals  of  each  pair;  oo,  the  cams  or  excentncs  for  lowering 
•^  raling  tSe  gill  bars ;  pp,  weighted  guide  lever  or  bell  cranks  for  guidmg  the  faUe. 


7«0 


FLAX. 


FLAX. 


761 


in  ite  descent,  and  moderating  the  shock  caused  by  its  weight  ^hen  coming  in  conUct 
with  the  lower  slide  or  support ;  q  and  r,  worm  and  wheel  for  l)ell  motion ;  «, «,  tj  «,  w, 
X,  line  of  wheels  from  pulley  to  front  roller  and  from  front  roller  to  back ;  1  2  3  line 
of  geering  from  back  roller  to  sheet ;  4,  6,  6,  7,  line  of  geenng  from  roller  to  delivering 
roller;  8,  front  roller  to  brush;  y  y,  from  back  shaft  to  back  roller.    _  ,,,,„*:„ik 

The  machines  for  the  second,  third,  and  fourth  drawings,  though  m  principle  essentially 
the  same,  yet  differ  in  some  of  their  minor  details  from  the  foregoing,  as  they  do  not  re 
quire  the  feeding  sheet  to  supply  them,  the  "  sliver,"  from  the  spreader  having  sufficient 
Coherence  as  to  allow  itself  to*be  drawn  from  the  cans  direct  by  the  back  rollers  of  these 
machines-neither  is  a  bell  motion  requisite  to  determine  thelength  o^  ^^^/^  P'^^fi^f  ^ 
by  them.    The  subjoined  sketches  show  the  general  parts  requisite  {Jigs,  bib,  bn.) 


A  A  {fig.  616.  617.),  framing;  b,  driving  pulley;  c,  support  of  sliver  carrier;  d,  roller 
for  carrying  sliver ;  e,  conductors ;  f,  can  containing  the  slivers  from  the  first  drawing ; 
G,  receiving  can ;  h  n,  the  heckle  carrying  spirals ;  i,  the  diagonal  or  doubling  bars ; 
K,  delivering  rollers ;  l,  the  drawing  rollers ;  m,  m^  rn,  the  retaining  rollers. 

The  roving  frame  is  the  same  in  regard  to  the  arrangement  of  its  back  and  front 


6E 


V62 


FLAX. 


rollers  and  gills,  as  the  drawing  frames  ;  and  as  the  position  and  manner  of  regulatine 
the  spoles  are  generally  the  same  as  adopted  for  cotton,  the  description  of  these  parte 
therefore  does  not  require  to  be  repeated  ;  but  an  improvement  patented  a  few  years 
emce  by  Mr.  P.  Fairbairn,  of  Leeds,  of  that  part  of  these  frames  which  relates  to 
regulating  the  taking  up  movement  of  the  bobbin  merits  particular  attention  as  bv  ii 
the  mconveniences  of  the  older  method  of  a  weighted  belt  and  cone,  and  those  of  the 
more  recent  disc  frames,  are  entirely  overcome.  The  principle  of  this  improvement 
consists  of  driving  a  pulley  by  pressure  between  two  discs  running  at  equal  speeds  in 
opposite  directions,  as  seen  Sit  figs.  618,  619,  620. 

Mgs.  618,  619.  To  obtain  the  variable  speed,  instead  of  using  a  cone  and  belt  as  in 
some  frames,  or  the  pulley  and  single  disc  as  in  others,  a  b,  the  horizontal  driving  discs, 
the  lower  one  a  is  keyed  to  the  shaft  d,  while  the  upper  6  is  free  to  turn  upon  it  •  t,  bevel 


wheel  titled  to  or  forming  one  piece  with  the  upper  disc  6;  c  bevel  wheel  keyed  to  shaft 
d;  e  intermediate  bevel  wheel  geering  in  the  bevel  wheels  c  and  i,  so  as  to  turn  them 
in  opposite  directions,  and  consequently  the  disc  to  which  they  are  directly  or  indi- 
rectly attached ;  g  the  variable  pulley  covered  with  leather  and  resting  upon  the  lower 
disc  a,  and  itself  pressed  upon  bv  the  weight  of  disc  6;  it  is  thus  driven  at  speeds 
varying  according  to  its  approach  to  or  from  the  shaft  d,  thus  answering  the  purpose 
of  the  traversing  leather  belt  of  the  cone  movement ;  h  shaft  keyed  in  the  pulley  o, 
from  which  the  variable  motion  is  transferred  to  the  bobbins, 

A  series  of  preparing  machines,  termed  a  •'  system,"  consists  in  general  of  1  spreading 
of  4  slivers  at  the  drawing  rollers,  united  into  one  by  the  doubling  bars  at  the  delivering 
roller,  2  frames  of  second  drawing,  in  all  24  bosses  2  frames,  third  drawing  containing  to- 
gether 36  bosses :  if  a  fourth  drawing  is  required,  2  frames  of  24  bosses  each,  or  48  bosses 
in  all.     180  spindles  of  roving  in  3  frames  will  well  supply  3000  spindles  of  medium 
spmnmg.     The  mode  of  using  this  "system  "  is,  as  has  already  been  said,  fii-st  to  spread 
the  stacks  of  line  upon  the  feeding-sheet  of  the  "spreader,"  then  to  receive  the  sliver  or 
slivers  there  produced  into  cans  capable  of  holding  1,000  to  1,200  yards  of  slivers.    Those 
cans  specially  intended  to  receive  the  slivers  from  this  machine  are  all  made  to  one  regu- 
lar weight ;  thus,  when  filled,  the  weight  of  line  each  contains  is  correctly  ascertained, 
and  by  the  bell  motion  the  length  is  also  known.     Upon  this  basis  is  founded  the  method 
of  producing  any  desired  number  of  yarn,  and  by  doubling  the  slivers,  a  degree  of 
equalisation  that  the  simple  spreading  would  be  unable  to  effect,  for  at  each  drawing 
and  at  the  roving  several  of  the  slivers  from  the  preceding  drawing  are  put  together, 
to  be  again  reduced  to  one  for  this  object  alone.     Hence,  the  weight  of  a  determmate 
length  in  yards  of  the  desired  yarn  being  known,  a  calculation  is  made,  combined  of  the 
drafts  and  number  of  doublings  the  material  has  to  undergo,  to  determine  what  the 
weight  should  be  of  that  length  of  slivers  contained  in  the  cans  from  the  spreader.     It 
is  ordinary  to  put  10  or  16  of  these  "cans"  together,  to  form  what  is  called  a  "set," 
the  slivers  of  which  are  united  at  the  second  drawing  with  the  subsequent  drawings 
and  rovmgs :  the  combination  of  two  or  three  slivers  at  each  boss  is  sufficient. 


FLAX. 


763 


Though  the  above  is  descriptive  of  the  "gill"  frames  now  in  use,  yet  it  should  be 
understood  they  are  by  no  means  the  first  or  only  results  of  the  attempts  made  to 
correct  the  defective  principle  of  the  original  roller  machines,  which  were  incapable 
of  holding  or  retaining  the  flax  with  a  suflicient  degree  of  regularity  owing  to  its 
unequal  length  and  unadhesive  nature.  The  consequences  were  that  the  yarns  pro- 
duced were  "lumpy"  and  unlevel,  making  it  evident  that  softie  improved  means  were 
necessary  for  more  completely  restraining  and  regulating  the  drawing  of  the  fibres. 
The  most  obvious  way  to  do  this  was  to  introduce  some  mode  of  partial  detention  by 
creating  a  friction  among  the  fibres  to  imitate  the  action  of  the  fingers  in  hand-spinning. 
This  led  to  causing  the  slivers  to  pass  through  and  among  several  ranks  of  serrated 
pins,  which  was  found  very  nearly  to  attain  the  object,  and  certainly  greatly  improved 
the  levelness  and  uniformity  of  the  sUvers.     Thus  the  use  of  "gills"  became  general 

about  thirty  years  since.  ,      .  ,      .      ,      a-  i  * 

Those  first  brought  into  general  use  were  constructed  with  circular  discs  or  plates 
for  carrying  the  faller  or  gill  bar,  which  at  the  same  time  were  guided  by  their  ends 
passing  in  fixed  slides  so  as  to  bring  the  gill  in  as  vertical  a  position  and  as  near  tlie 


drawing  roller  as  possible.  The  figures  (621,622.)  are  profile  and  front  views  of  the 
working  parts  of  one  of  these  gills :— a,  slotted  plate  or  disc,  of  which  a  pair  were  keyed 
upon  a  shaft  b,  so  as  to  carry  each  end  of  the  faller,  d,  passing  through  the  slots  c,c;% 
the  fixed  excentric  slide ;  o,  h  the  drawing  rollers ;  e  the  holding  rollers. 

This  was  succeeded  by  the  "chain  gill,"  in  which  the  fallers  were  carried  forward 
by  an  endless  series  of  connected  links,  or  jointed  together  "slotted  plates,"  instead  of 
the  simple  circular.  The  object  of  this  was  to  increase  the  flat  surface  of  gill  bars 
between  the  holding  and  drawing  rollers,  making  it  more  suitable  for  the  longer  de- 
scriptions of  material.  The  slides  and  rollers,  being  similar  in  these  machines  to  those 
in  the  former,  are  not  repeated,  but  the  sketch  of  five  slotted  plates  is  given  mfig.  62S. 


623 


From  the  evident  importance  of  bringing  the  retaining  effects  of  the  gills  as  closely 
as  possible  to  the  point  where  the  movement  of  the  drawing  fibres  is  greatest,  severaj 
attempts  have  been  made  to  improve  the  above  described  gills  m  this  respect     With 

6E2 


- 

I 

1 

■ 

' 

764 


FLAX 


'(jl1^^)^^l\l:^:^AI::^^^^^  or  considerable  ingenuity, 

Bcription  is  as  follows :—  mention,  though  it  never  came  into  use.     Its  de^ 

parallel  parte  of  the"li,^8  .7  th.  J^  wft'-nV'  I""*  ""  t""'  bell^^ranks  aro  i„  the 
Live  at^the  contracted  part  thfgufded  ent  w  .  h  t''"'  t^-  'f'"',  "  *'  •""  «">«»  ">«; 
consequently  the  gill  depressed  i!  o  2  ■  f  !?•  •  *^'  '*^°"^'"  '°'<'  "'«  ?»«!"«■>  «  %  and 
drawilg  roller,  »h^en,  oSa  cltiniit  ttir  ^"^  lu""  """'*  "•."»  »»  "='«"  *»>« 
and  penetrate  the  sliier  b/the  reveSiLwLTnf  ?!.'''%"*  T'"  "'"^^  »»  "»« 
The  objection  to  this  infenio  JStetrth:  t^,::^ottC' :^::t,'^^ 


624 


Ur^l  •"•'.0  **  «     F=n 

V  V««^^^'S''w2-  '■ "."i'.-"-'.-    o  •    ■' 


■=1^ 


/? 


o; 


i^u^e'd  a^grtt  twtT  °'  "'  ^'"-  "^  ''^  ''<""'''=  f"""-  ''^"--fe.  -<i  g^I  necessarily 


FLAX. 


765 


m*nnpr  thev  were  first  constructed,  to  approach  closer  than  even  in  the  most  perfected 
rnstmclion  oT^he  othe^  side  of  the  drawing  roller,  and  still  maintain  the  pins  m 

TveSpo^^^^^^^  Recently  this  object  has  been  more  perfectly  attained  by  a  patented 
rmproved  construction  adopted  by  Messrs.  P.  Fairbairn  &  Co.,  whereby  the  obstacle  to  he 
SFerXllv  touching  the  roller-has  been  removed,  and  thus  producing  the  fuU  holding 
eslZ  If  theVll  to  latest  possible  moment.  This  is  effected  by  employing  a  niethod 
of  supportine  the  spirals  by  their  working  in  tubular  recesses  m  the  side  plate  of  the 
macUne  along  these  recesses  are  longitudinal  openings  through  which  the  faller  end 
Zies  to'en  erl^etween  the  threads  of  the  spiral,  and  which  serve  also  as  slides  to  sup^ 
S^  the  faller.  As  by  this  means  the  supports  or  plummet  blocks  that  intervened 
Eetween  the  end  of  the  spirals  and  the  roller  are  suppressed,  the  faller  is  enabled  to 
advance  to  the  place  they  formerly  occupied.  Fig.  625.  and  626.  show  this  comparison  of 
th^^X'afd'rit'rL^^tm  /b spiral/;  c,  ^  the  par^  by  wluch  the^^^^^^^^^ 

ported  beinjr  in  fia.  625.  small  pivots  m  plummet  block  dd,  and  in  fig.  626.  hoUow  tuoe- 

Fike  rlsses'in  & 

F  bearinffs-  g  drawing-rollers  ;  u  pressing-rollers ;  1 1  passage  of  the  taller  s  aescent. 

Here  ft  may  be  as  well  to  observe  that  the  same  parties  have  still  more  lately  mtroj 
daced  anoSer  important  amelioration  in  these  machines  for  remedying  the  noise  and 
wear  and  tear  which  ordinarily  attend  them  by  the  abrupt  and  violent  descent  ^the 
feller. %r  627.  shows  a  sectional  front  view  of  a  head  havmg  this  improvement 

n=  "" 


* 


applied  A  A  supports  for  screws ;  6,  c  top  and  bottom  screws ;  d,  d  the  new  cams  fixed 
on  shafts  parallel  with  the  screws  and  revolving  at  the  same  speed.  Thus,  these  cam. 
ii  receive  the  faller  e  e  at  their  largest  diameter,  at  the  moment  they  are  iree  to 
descend  and  guide  them  gradually  down  to  the  lower  slide.  . 

Th^  constructed,  the  "screw  gill"  continues  to  be  the  most  esteemed  m  principle, 
though  not  without  some  serious  objections  in  practice.     For  the  abrupt  and  angular 
movements  of  the   "  faller"  even  here  not  only  liberate  too  suddenly  a  portion  of  the 
fibres  that  should  be  but  gradually  relaxed  at  the  moment  of  being  drawn,  but  cause 
consTderable  wear  and  tear  to  itself,  the  slides,  and  the  gills  attached  to  it ;   to  which 
Z  e  Jdestniction  must  be  added  the  great  friction  of  the  worm  movement ;  these, 
however  in-line"  preparing,  where  the  fibres  are  long  and  straight,  and  the  drafts  em- 
XTed Targe,  and  w^hcr^  coLquently,  a  comparatively  slow  movement  of  the  gills  is 
Sed  afe  not  so  much  felt  as  in  the  preparation  of  tow,  where  they  become  serious^ 
Jn"  tow  preparing"  the  first  operation,  as  before  stated,  consists  of  -carding,    which 
is  generally  repeated  over  two  separate  machines,  which  are  respectively  called  the 
"breaker"  and  the  "finisher"  cards.     'Diey  are  essentially  the  same  in  principle,  and 
vary  but  little  in  construction,  the  only  difference  being  that  the  "breaker"  is  fed  or 
lupplied  by  the  disjointed  parcels  of  tow  from  a  creeping  sheet  (as  the  spreader  with 
"Hne  "Una  delivers  its  slivei-s  into  a  can,  whereas  the  finisher  is  fed  from  a  bobbin  upon 
whLh  several  of  the  slivers  from  the  "  breaker"  are  united  by  a  machine  expressly  for 
Jhat  purpose  called  a  "lap  frame ;"  this  card  thus  receives  its  supply  of  work  in  a  very 
Regular  form,'  and  previously  to  delivering  it  in  the  form  of  slivers  causes  them  to  pass 
Tvf  r  a  jH?{  to  consolidate  and  strengthen  them  before  delivering  them  mto  the  receiving 
^In.  its  also  generally  clothed  with  a  finer  description  of  wire  fiUetmg  than  the 
breaker     Though  it  is  the  bettor  method  to  card  thus  the  tow  twice,  yet  this  second 
cirding  is  sometimes  dispensed  with;  in  that  case  this  auxiliary   "  g.ll"  .is  similarly 
fixed  to  the  first  card  or  breaker.     The  cards  employed  for  tow  are  machines  of  con- 
mderable  weight  and  importance,  the  main  cylinder,  or,  as  it  is  sometimes  called,     switt, 
being  from  4  to  5  feet  diameter  and  4  to  8  feet  long;   those  most  generally  emdoyed 
^rie  feet  long.     Previously  to  entering  upon  the  detailed  description  of  a  card,  it  may 
be  as  well  firit  to  trace  in  general  terms  the  progress  of  its  operations,  as  tendmg  to 

^^-Ttt^l^TsftrS  Parcelsof  10  to  20  drachms;  these  are 

fhPn  shaken  out  and  spread  so  as  to  cover  certain  definite  portions  of  the  creeping 
fLding  Shelby  which  they  are  conducted  to  the.first  pair  of  rollers  called  the  feeder. 
These  rollers  are  covered  with  a  leather  band,  in  which  are  fixed  in  close  array  a 
number  of  wire  points  about  \  an  inch  long,  and  having  a  tangential  inclination  to  the 


766 


FLAX. 


FLAX. 


767 


.M 


circumference  of  the  rollers,  which  are  about  2*  inches  diam^tpr     Th^  ir.rrr  ^     • 


movable  pulley  f  ;  o,  g,  g,  workers ;  i,  i,  i,  the  three  doffers  :  h.  n  h  intermediate  wheels 

Sce^^r«7i5      '  1^  del^^erjn^  ro  lers:  m,  back  roller  of  auxiliary,  gill:  n,  gill 
surface ,  o,  p,  drawmg  rollers ;  <3^  delivenng  rollers  and  bell  motion  for  melsuring  the 


628 


629 


slivers  into  the  cans  e;  ss,  doubling  plate ;  t,  pulley  for  driving  auxiliary  gills  by  bell 
from  the  pulley  e. 

The  lap  frame  to  which  allusion  has  already  been  made  as  the  necessary  adjunct  to 
the  cards  when  double  carding  is  to  be  performed,  is  employed  to  collect  together  a 
number  of  slivers  from  the  "  breaker  "  by  winding  or  lapping  them  upon  a  cylindrical 
piece  of  wood,  which  may  be  described  as  a  bobbin^shank,  thus  producing  an  equalisation 
of  the  slivers  of  tow  as  the  making  up  of  sets  effected  in  line  preparing ;  from  50  to 
fiOlbs.  of  tow  is  the  usual  complement  of  one  of  these  bobbins,  the  length  and  the 
diameter,  when  full,  about  22  inches ;  thus,  a  6  feet  wide  finisher  card  will  take  off  these 
bobbins  at  once;  from  15  to  20  is  the  number  of  slivers  usually  wound  together,  and 
the  completion  of  a  bobbin  by  the  ringing  of  a  bell,  connected  with  the  measuring 
cylinder  of  the  machine.     The  following  is  a  descriptive  drawing  of  the  lap  machme. 

AAA,  (Jiff.  630.  &  631.)  framing;  b,  measuring  and  pressing  cylinder;  c,  c,  c,  driving 
pulleys  connected  with  different  geering  to  change  the  speed  as  the  bobbins  fill ;  d,  bob- 
bin or  shank  intended  to  be  filled ;  e,  table  to  receive  the  bobbin  when  about  to  be  taken 
from  the  machine ;  f,  weight  to  increase  the  effect  of  pressure  of  the  measuring  cylinder 
by  the  connecting  rods  g,  g,  g,  which  are  split  for  part  of  their  length  in  order  to  pass 
the  shaft  h,  and  at  another  gg  have  racks  into  which  work  pinions  keyed  on  the  shaft  of 


*IQ% 


FLAX. 


FLAX. 


769 


tlie  hand  wheel  i,  for  the  convenience  of  raising  and  lowering  the  cylinder  and  weight 
The  shaft  h  is  divided  at  the  plates  k  and  l.,  and  provided  with  sockets  to  receive  the 
end  of  the  bobbin  shank  b,  which  is  introdnced  by  sliding  back  the  piece  h  n,  and 
returning  it  by  lever  m,  and  thus  is  coupled  and  turns  together  with  two  pieces  of  shaft 
B,  as  also  the  disc  plates  k  and  l,  which  are  to  serve  as  temporary  ends  to  the  bobbin 
during  the  time  of  its  filling,  and  thus  b^  turning  with  it  avoid  that  rubbing  and 
felting  effect  upon  the  edges  of  the  tow  so  injurious  in  the  machines  formerly  constructed. 


and  by  the  bobbin  acting  as  the  driver  to  the  cylinder  the  slivers  are  drawn  tighter, 
and  thereby  avoid  those  plaites  that  the  other  machines  were  so  liable  to  produce. 

As  before  mentioned,  some  objections  were  found  to  the  working  of  the  screw-gill,  of 
a  nature  detrimental  to  the  machines  themselves,  which,  though  not  of  great  importance 
in  "line,"  were  much  aggravated  in  tow  preparing,  as  the  lesser  drafts  there  employed 
cause  a  greater  wear  and  tear  of  the  fallers  and  gills.  The  objection  to  these  machines, 
however,  is  not  confined  to  this  point  only,  but  extends  also  to  their  effect  upon  the 
material  itself.  The  fibres  of  the  tow  sliver,  as  coming  from  the  cad,  are  in  a  light  and 
much  confused  state,  which  renders  them  liable  to  be  easily  separated ;  so  that  the  faller, 
by  its  sudden  descent,  has  a  tendency  to  draw  some  down,  and  become  lapped  by  them, 
as  well  as  to  make  so  marked  a  difference  in  the  thickness  of  the  sliver,  by  the  with- 
drawal of  the  retaining  comb,  as  materially  to  injure  the  quality  of  the  yarn.  Thus 
this  "gill"  was  not  enabled  to  hold  its  place  in  tow  spinning,  when  other  circumstances 
led  to  greater  attention  being  paid  to  this  important  branch  of  the  flax  business,  and  it 
became  a  desideratum  to  have  a  machine  free  from  these  defects,  and  capable  of  working 
without  derangement,  at  much  greater  velocity  than  was  safe  with  the  "screw-gill." 
These  desiderata  the  "  rotary  "  gill,  patented  by  Messi-s.  Fairbairn  <fe  Co.,  amply  supplies. 
For  in  this  gill  the  circular  form  of  the  gill  sheet  obviates  the  necessity  of  having 
several  fallers,  and  the  simple  motion  creates  neither  friction  nor  abruptness  of  effect, 
while  the  retention  of  the  fibres  being  continuous,  the  slivers  produced  are  perfectly 
level  and  uniform,  consequently  these  gills  are  extensively  applied,  as  the  auxiliary  gill 
explained  in  carding,  as  well  as  for  the  subsequent  drawings  and  rovings  of  tow,  and 
sometimes,  as  will  be  afterwards  seen,  to  coarse  spinning.  The  theoretical  construction 
of  these  rotary  gills  will  be  seen  by  the  annexed  sketch. 

M,  {Jiff.  632.)  back  rollers,  but  when  applied  to  a  card  at  top  and  bottom  holding  rollers 
are  again  employed  ;  n,  the  rotary  gill  sheet  having  the  pins  inclined  backwards,  so  as 
to  insure  the  impalement  of  the  sliver  when  the  fibres  begin  to  draw :  p  and  o,  the  draw- 
ing and  pressing  rollers ;  the  doubling  bars  or  plates  are  the  same  to  these  gills  as  to 
the  "screw-gills." 

Subsequently  to  the  carding  the  preparation  of  tow  is  completed  by  making  up  set* 


# 


of  cans  for  the  second  drawing,  as  explained  for  line ;  these  slivei-s  are  doubled  and 
drawn  once  or  twice  more,  and  then  roved.  The  drafts  used  in  tow  preparing  are 
from  6  to  8,  for  as  the  fibres  are  shorter,  it  necessitates  the  eraplo}Tnent  of  less  draft. 
In  both  line  and  tow  preparing,  lesser  drafts  are  employed  as  the  stages  advance  the 
gills  finer,  and  the  conductors  narrower ;  also  for  both  materials  much  attention  is 
requisite  to  keep  the  various  parts  of  the  machines  in  good  order,  free  from  bent  or 
broken  pins,  and  chipped  or  indented  rollers,  for  no  subsequent  operation  can  cure 
the  defects  that  may  be  produced  b}^  negligence  in  these  particulars.  The  drawing 
and  roving  frames  for  tow  are  shown  in  figs.  633,  634,  635. 

A  A,  {Jig.  634.) drawing  framing;  b,  driving  pulleys;  c,  rotary  gill  sheet;  d,  drawing 
roller;  e  pressing;  f,  g,  pairs  of  delivering  rollers;  a,  doubling  plate;  i,  back  con- 
ductor ;  K  back  roller  wheel  with  pulley  to  turn  the  sliver  rail  i. 

A  A,  {Jig.  634  <fe  635.)  roving  frame ;  b,  pulley  and  flv  wheel  combined ;  c,  drawing 
roller :  d,  rotary  gill ;  a  a,  stand  for  gill  movement  The  regulation  of  the  bobbins 
is  effected  in  the  same  manner  as  already  described  for  line  roving. 

6th.  Spinnijig.—Thk  operation  consists  in  drawing  the  "rovings"  down  to  the  last 
degree  of  tenuity  desired,  and  twisting  them  into  hard  cylindrical  cords,  which  are 
called  "yarns." 

There  are  three  modes  of  performing  this  operation ;  the  first,  and  perhaps  oldest,  is 
that  where  the  drawing  and  twisting  are  performed  altogether,  with  the  material  pre- 
served dry,  and  without  breaking  or  shortening  the  fibre ;  the  second  is  that  which 
likewi^,  without  changing  the  length  of  the  fibres,  draws  them  while  dry,  but  wets 
them  just  at  the  moment  before  twisting.  This  method  is  the  nearest  imitation  of 
hand  spinning,  and  makes  the  yarn  more  solid  and  wiry  than  the  first ;  as  the  fibres 
of  flax  losing  their  elasticity  while  wetj  unite  and  incorporate  better  with  one  another. 
The  third  mode  of  spinning  has  been  much  more  recently  introduced  than  either  of 

Vol.  L  6  F 


■ma 


770 


FLAX. 


FLAX. 


771 


1 1 


!  ' 

.!         I 


636 


the  others,  and  by  it  the  fibres  are  wetted  to  saturation  previously  to  being  drawn, 
whereby  they  are  not  only  much  reduced  in  length,  but  their  degree  of  fineness  is  in- 
creased by  the  partial  solution  of  the  gummy  matter,  inherent  in  the  flaxen  material : 
owing  to  these  circumstances  equally  good  j-arns  can  be  produced  by  this  mode  of 
spinning  from  line  and  tow  of  inferior  quality,  to  what  could  be  employed  upon  either 
of  the  others,  and  not  only  that,  but  much  finer  yams  can  be  now  spun  than  were 
possible  previous  to  its  introduction.  It  has  therefore  not  only  nearly  superseded  all 
other  methods  of  spinning  for  yarns  from  20*8  to  the  finest,  but  has  much  increased 
the  extent  and  importance  of  the  flax  manufacture. 

The  only  difference  in  spinning  frames  for  "  line  or  tow,"  when  employed  for  the 
older  methods,  consists  in  the  length  of  reach,  which  generally  involves  the  necessity 
of  having  separate  machines  for  each  material,  though  sometimes  they  are  mad«  with 
a  capacity  to  be  adapted  to  either  purpose.  In  the  third  method  the  same  machines 
were  used  promiscuously  for  "  line  or  tow." 

The  yams  spim  wholly  dry  are  used  for  the  coarse  description  of  woven  goods,  as 
packing  canvass  corn  sacks,  and  when  partially  bleached  for  sheetings  and  towellings 


as  from  its  greater  elasticity  and  openness  it  fills  up  better  in  weaving.     Those  spun 

partially  wetted  are  employed  for  a  somewhat  superior  de- 
scription of  linen  goods,  and  the  solid  silky  appearance  qua- 
lifies them  for  drills,  damasks,  Ac,  as  well  as  for  sewing 
and  shoe  threads ;  a  somewhat  inferior  material,  by  this 
manner  of  treatment,  makes  an  equally  good  yarn  as  a 
better  material  spun  dry.  The  yarn  produced  from  this  wet 
principle  is  rather  inclined  to  have  a  cottony  appearance,  and 
from  the  comparative  ease  with  which  an  inferior  material  can 
be  made  to  represent  an  apparently  fine  good  yarn,  the  appli- 
cation of  yarns  thus  produced  is  exceedingly  various  and  some- 
times deceptive,  though  when  good  materials  are  used,  these 
yarns  afford  durable  and  handsome  drills,  shirtings,  lawns,  and 
cambrics,  as  well  as  fine  sewing  threads. 

The  mechanical  arrangement  for  twisting,  and  then  wind- 
ing the  yarn  upon  a  bobbin,  is  called  the  "  throstle  "  principle, 
supposed  to  be  so  called  from  the  whistling  noise  they  create 
when  working  at  full  speed,  which  is  from  2,500  to  4,000 
revolutions  a  minute.  The  following  diagram  will  explain  the 
principle,  which  is  applied  alike  to  all  the  mqdes  of  spinning 
above  described. 

A  A,  {fig.  636.)  the  spindle;  b,  the  bobbin,  loose  and  inde- 
pendent of  the  spindle  in  regard  to  turning,  and  rising,  and 
lowering,  but  through  which  the  spindle  passes ;  c  c,  the  flyer 
screwed  to  the  spindle  top;  d,  table  called  bobbin  lifter, 
as  while  at  work  it  rises  and  lowers  to  lay  the  yarn  on 
the  whole  bobbin  equally;  e,  a  small  cord  to  press  on  the 
bobbin  by  the  weight  f;  g,  pulley  by  which  the  spindle  is 
driven. 

Many  attempts  have  been  made  to  improve  upon  this 
principle,  in  order  to  avoid  or  lessen  the  strain  upon  the 
thread  in  its  passage  Irom  the  drawing  rollers  to  the  flyer 
eye;  but^  till  recently,  without  any  degree  of  success.  The 
onl^'  improvement  at  present  known,  and  which  promises 
to  become  general,  is  that  where  the  necessity  to  have  a  top  to  the  bobbin  is  avoided. 
It  will  be  seen  from  the  above  diagram,  that  the  yarn  is  compelled  to  rub  the  top  of 
the  bobbin,  and  the  friction  thereby  created  quickly  causes  it  to  become  rough ;  and 
therefore  it  has  a  tendency  to  catch  and  break  the  thread.  The  desirableness,  there- 
fore, of  having  a  clear  course  for  the  yarn  was  evident,  and  this  improvement  that 
we  are  about  to  explain  produces  the  effect  by  employing  what  is  called  a  coping 
motion,  whicli,  like  that  used  in  mule  spinning,  preserves  the  layers  of  thread  upon  the 
bobbia  ever  in  a  pointed  or  conical  state,  and  therefore  self-supporting  without  the  aid 
of  the  wooden  end  of  the  bobbin.     See  Cotton  Spinning. 

The  arrangement  of  the  rollers  for  holding  and  drawing  the  slivers  or  rovings,  as 
well  as  the  plates  and  rollers  for  aiding  to  retain  the  twist  of  the  rovings,  in  order  to 
render  their  elongation  more  equable  when  to  be  drawn  dry  and  spun  upon  the  older 
methods,  will  be  seen  '\nfig.  637. 

A,  (Jig.  637.)  roving  bobbin  ;  b,  back  or  holding  roller ;  c,  carrying  roller,  d  flat  plate 
with  a  slightly  curved  face ;  the  carrying  roller  and  plate  are  so  placed  as  to  cause  a 
degree  of  friction  to  the  roving  when  passing  over  them,  so  as  to  retain  the  twist,  and 
thus  act  as  the  pins  in  the  "gill  frames;"  e,  tin  conductor  for  contracting  the  roving 
at  the  moment  of  being  drawn;  /,  metal  roller;  g,  wooden  roller  pressed  against  the 
drawing  roller  in  order  to  pinch  the  roving ;  A,  lever  and  weight  When  it  is  intended 
to  wet  the  yarn  previously  to  twisting,  the  trough  i  is  used,  in  which  is  water,  which 
is  supplied  to  the  roller  g  by  the  capillary  attraction  of  a  piece  of  cloth  immersed 
therein,  and  bearing  against  the  roller  by  lever  k. 

The  machines  for  "  wet"  spinning  are  of  a  very  different  construction  and  appearance ; 
as  the  close  proximity  of  the  holding  and  drawing  rollers  prevents  the  intervention  of 
holding  rollers  or  friction  bars,  while  the  force  requisite  to  draw  the  rovings  at  the  short 
reaches  used,  varying  from  2^  to  4  inches,  requires  each  pair  to  be  deeply  and  accurately 
fluted  into  one  another.  The  water  used  is  heated,  in  order  by  the  expulsion  of  the 
fixed  air  more  rapidly  and  completely  to  saturate  the  rovings  while  passing  through 
it.  The  following  drawings  and  description  will  be  sufficient  to  give  an  accurate  idea 
of  the  principle  of  these  machines,  which  are  generally  20  to  30  feet  in  length,  and 
contain  200  to  nearly  300  spindles;  that  is,  100  to  150  on  each  side. 

A  A  A  A,  {fig.  638.  &  639.)  framing ;  b  b,  stand  for  roving  bobbins ;  c,  driving  pulleys 
fixed,  upon  the  axle  of  cylinder  d,  from  which  pass  endless  cords  to  drive  the  spindles 

5F 


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112 


FLAX. 


I   i 


FLAX. 


11Z 


c  •;  F,  step  rail  of  spindles ;  g,  collar  rail  for  ditto ;  h,  bobbin  lifter ;  1 1,  front  roller ;  k  k, 
back  roller ;  l,  back  pressing  roller ;  m,  top  pressing  roller  (these  are  generally  made  of 
box  wood,  but  sometimes  of  gutta  percha) ;  n,  n,  levers  in  connection  with  the  excentric  to 
produce  the  rise  and  fall  of  the  bobbin  lifter ;  o  o,  thread  plate ;  q,  q,  saddles  or  transverse 
oars  resting  on  the  axles  of  the  back  and  front  pressing  rollers,80  that  one  lever  and  weight 
acts  for  both  by  the  connecting  rod  to  lever  r  r,  which,  in  order  to  cause  more  pressure 
on  the  drawing  than  on  the  back  roller,  is  placed  on  the  saddle  nearer  the  former  than 
the  latter.     1,  2,  8,  4,  6,  6,  1,  8,  train  of  wheel  work,  by  which  the  movements  are  dia- 


^ributed.  a,  a,  a,  the  trough  of  hot  water  maintained  by  steam-pipes  at  the  desired  tem- 
^>erature ;  b,  b,  guide  rods  or  pipes  to  cause  the  roving  to  pass  under  the  water.  In 
order  to  avoid  the  rollers  becoming  indented  by  the  roving  always  passing  on  the  same 
place,  they  are  caused  to  traverse  the  breadth  of  the  rollers  by  a  traversing  guide  rail, 
moved  by  an  excentric  at  the  worm  apd  wheel  c;  d,  flyers,  and/,  spindles. 

Here  it  may  be  proper  to  introduce  a  description  of  the  machines  for  twisting  the 
yarns  when  spun  into  "  threads  "  used  for  sewing,  <fec.  The  yarns  spun  for  this  purpose 
should  always  be  made  of  a  somewhat  superior  description  of  line  to  that  employed  for 
the  same  number  of  yarns  for  weaving,  and  have  rather  less  twist.  They  are  generally 
taken  while  wet  on  the  spinning  bobbins  to  the  twisting  frame,  and,  when  combined 
together,  the  union  is  eflFected  by  a  torsion  in  the  opposite  direction  to  the  original  twist 
of  the  separate  yarns. 

6.  Reeling.  —  This  operation  consists  in  winding  the  yam  off  the  bobbins  of  the 
spinning  or  twisting  frames,  and  forming  it  into  hanks  or  skeins.  The  various  denomi- 
nations of  the  skeins  into  which  yarn  is  reeled,  and  then  the  forms  or  combinations 
they  are  made  up  into,  are  as  follows : — 

The  lea  containing  300  yards 

10  leas  making  1  bank 

20  hanks    „  1  bundle 

6  bundles,,  1  packet 

It  is  by  the  standard  lea  of  300  yards  that  the  description  of  yarn  is  known  from  the 
number  contained  in  1  lb.  weight ;  thus  No.  20.  contains  20  leas  or  6000  yards  for  1  lb. 
weight.  In  Scotland,  the  subdivisions  are  rather  diflferent  from  the  foregoing,  which 
are  employed  in  England  and  Ireland;  the  lea,  however,  remaining  the  same: — 

88  leas  make  1  spindle 
6  „  1  rand 

12  rands,,  1  dozen. 

The  reeling  is  peformed  upon  exceedingly  simple  machines,  generally  put  in  motmu 
by  the  hand  of  the  person  attending  them,  though  sometimes  they  are  driven  by 
the  motive  power  of  the  factory.  The  reel  is  made  suflSciently  long  to  receive  twenty 
bobbins,  and  the  barrel  upon  the  yam  is  found  in  one  length ;  the  diameter,  however, 
varies  so  as  to  suit  the  different-sized  yarns  to  be  reeled.  For  the  coarsest  yams  and 
down  to  16.  and  20.,  the  largest  circumference  is  used  of  3  yards,  from  that  to  about 
No.  100.  2i  yards,  and  for  the  finest  yarn  li  yards  is  found  most  convenient  These 
various  circumferences  are  compensated  either  by  putting  a  great  number  of  threads 


ti 


7^4 


FLAX. 


FLAX. 


115 


till 


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li 


into  each  "  tye,"  or  increasing  the  number  of  tyes,  so  that  opposite  to  each  one  of  the 
20  bobbins  an  entire  hank  should  be  formed  before  taking  the  yarn  off;  thus  at  each 
"  stripping,"  one  bundle  is  turned  off.  To  facilitate  the  stripping,  one  of  the  rails  of  the 
barrel  is  made  to  fall  in,  and  thus  slacken  the  hanks;  care  is  taken  to  leave  the  leas 
bands  very  loose,  in  order  to  allow  the  yarn  to  be  spread  out  in  drying  and  bleaching. 
The  determinate  lengths  of  yarn,  when  wound  on  the  reel,  are  notified  by  the  ringing 


of  a  bell  connected  with  the  axle  of  the 
ordinary  hand-reel. 


barrel.     Figure  below  shows  the  form  of  an 

A  A  (Jiff.  640.)  framing;  b  b 
reel  barrels;  c  box  or  trough  to 
receive  empty  bobbins,  Ac. ;  d  d 
bobbins  in  position  of  being  reeled ; 
E  £  guide  rails  moveable  so  as  to 
place  the  leas  side  by  side  on  the 
reel;  //  bell  wheels;  g  g  bells 
for  each  reel  barrel  suspended  ou 
springs. 

To  these  hand-reels  there  are 
many  objections ;  for  it  is  evident 
that  the  correctness  of  measure  de- 
pends entirely  upon  the  attention 
of  the  reeler,  and  the  stoppages 
arising  from  the  breaking  of  a 
thread  or  the  finishing  of  a  bobbin 
interrupt  the  work  of  all  the  others. 
These  objections  rendered  it  necessary  to  attempt  some  ameliorations  of  the  system  by 
the  introduction  of  a  reel  that  should  automatically  prevent  these  causes  of  error. 
Such  a  reel  was  patented  a  few  years  since,  and  is  now  in  general  use  in  Scotland ; 
it  is  80  contrived  as  to  have  the  capacity  of  stopping  itself  when  a  thread  breaks,  when 
a  bobbin  finishes,  and  leas  and  hanks  completea ;  and  having  but  four  or  five  bobbins 
in  one  compartment,  the  stoppages  affect  but  few  at  a  time ;  and  as  this  machine  can 
be  worked  by  less  skilful  persons  without  possibility  of  error,  much  saving  is  effected 
both  in  wages  and  material.  The  annexed  figure  (641.)  shows  the  principle  of  this 
Unproved  reel. 

A  A  {Jig  641.)    framing;  b  reels;  c,  c  pendulums  on  which  are  hung  the  bobbins 

to  be  wound  off;    n  drivmg  shaft  with  ratchet  wheels    opposite  to  each  pendulum, 

so  that  when  a  thread   breaks,  the  pendulum  to  which  it  was  attached  falls  into  the 

ratchet  wheel,  and  thus  stops  it. 

The  drying  of  wet  spun  yarns  should  always,  when  possible,  be  done  in  the  open  air 


oy  spreading  the  hanks  upon  horizontal  poles  through  them,  with  another  similar  pole 
resting  inside  upon  their  lower  extremities,  in  order  to  keep  them  straight.  If  arti- 
ficial heat  is  employed,  that  from  steam  or  hot  water  is  preferable,  and  it  should 
never  exceed  90°  Fahr.,  as  otherwise  the  yarn  is  apt  to  become  harsh. 


1.  Making  up. — ^By  this  operation  is  first  produced  upon  the  yams  a  certain  soft- 
ness and  suppleness,  and  then  the  hanks  are  folded  and  tied  up  m  conveniently-sized 
packages. 

In  order  to  give  the  yarns  that  soft  and  mellow  feel  so  agreeable  and  characteristic 
of  flax  yams,  the  hanks,  when  brought  from  the  drying,  are  what  is  called  shaken 
down  and  pin-worked.  This  is  done  by  separating  a  few  at  a  time,  and  passing  them 
on  to  a  strong  arm  of  wood  fixed  to  a  wall  or  pillar,  when  with  a  heavy  baton  put 
through  them,  the  workman  proceeds  to  stretch  the  hanks  with  a  sudden  check  or 
jerk,  which  operation  he  repeats  in  two  or  three  places  so  as  to  thoroughly  straighten 
and  sliake  them  loose ;  he  then,  vising  the  same  baton  as  a  lever,  twists  them  lightly 
backwards  and  forwards  till  the  desired  degree  of  suppleness  is  obtained.  A  brush 
is  sometimes  used  to  aid  the  straightening  and  separating,  as  well  as  to  increase  the 
gloss  on  the  yam.  The  hank  or  hanks  will  then  be  found  to  have  assumed  a  flat 
shape,  as  on  the  reel,  which  facilitates  their  folding  with  a  dexterous  twist  by  their 
middle,  when  they  are  laid  in  square  piles  upon  a  table  with  their  twisted  folds  one 
upon  another.  They  are  majntamed  in  the  perpendicular  by  a  few  supports  fixed  in 
the  table.  Sometimes  these  packages,  which,  according  to  the  sizes  of  the  yarn,  con- 
sist of  from  J  of  a  bundle  to  5  or  6  bundles,  are  bound  together  by  some  of  their  own 
hanks,  but  sometimes  by  cords  in  three  or  four  places  of  their  length.  It  is,  however, 
better  to  employ  a  bundling  press  than  an  ordinary  table,  as  the  yarn  can  then  be 
made  up  more  solidly,  thus  both  improving  its  appearance,  and  causing  it  to  occupy 
less  space  for  packing  and  stowage.  The  bundling  presses  are  made  upon  the  same 
principle,  but  on  a  smaller  scale,  for  making  up  the  small  packets,  in  which  sewing 
threads  are  generally  presented  for  sale,  and  are  upon  the  following  construction, 
(Jigs.  642,  643). 


JFig.  642.  front  view ;  Mg.  643.  profile.  AAA  frame ;  b  table  or  flat  top  of  frame ;  c 
rising  table ;  d  d  iron  uprights  fixed  to  b  ;  e  k  bars  hinged  at  one  end  to  uprights  d  d, 
to  shut  across  the  press,  and  be  caught  and  latched  down  by  the  spring  catch  l  fixed 
to  the  upright  d  along  one  side  of  the  press ;  f  f  racks  for  lifting  the  table  c  by  the 
pinions  on  shaft  g  ;  h  crossed  levers  for  turning  the  shaft  o ;  i  ratchet  wheel  engaging 
the  detent  k,  and  thus  retaining  the  shaft  o  in  any  required  position,  and  thus  of  course 
maintaining  the  pressure  of  table  c  against  the  top  cross-bars  k. 

8.  Weaving,  is  the  operation  by  which  the  yarns  are  combined  into  textile  fabric*, 
such  as  canvas,  linen,  drills,  damasks,  Ac,  and  a  great  variety  of  other  denominations 
of  article  for  use  and  ornament. 

Hitherto  the  weaving  of  linens  has  been  carried  on  by  the  ancient  and  well  known 
hand  process,  so  ancient  and  so  well  known  as  to  place  the  operative  practising  it 
among  the  worst  paid  of  any  other  art.  Now,  however,  there  are  several  extensive  and 
thriving  establishments,  where  machinery  has  taken  the  place  of  much  squalid  misery, 
and  at  much  cheaper  rates  produces  to  consumers  superior  articles,  and  still  affords  good 
payment  to  the  operative.  The  improvements  in  power  weaving  which  have  led  to 
this  result  are  not  founded  upon  one  or  even  a  few  successful  inventions  or  contrivances, 
but  are  the  combination  of  a  great  many  that  have  occupied  much  time  to  mature. 
Many  difiiculties  had  to  be  overcome  in  the  weaving  of  flax  that  did  not  exist  in  that  of 
other  materials ;  and  for  a  considerable  period  the  expense  of  linens  rendered  their 


Ji 


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1 1' 


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FLAX. 


consumption  so  limited,  as  to  make  their  production  by  power  weaving  but  a  very 
secondary  object  The  ^eatest  obstacle  of  a  practical  nature  to  the  introduction  of  the 
automatic  weaving  of  hnens  was,  the  stubbornness  or  want  of  elasticity  in  the  yam, 
which  caused  frequent  breakages,  and  much  confusion.  In  woollen  or  cotton  gocdsl 
if  a  thread  or  yarn  should  chance  to  be  a  little  tighter  than  the  others  in  the  warp,  its 
elasticity  will  allow  it  to  come  up  to  the  general  bearing  of  the  others  when  the  weft 
is  struck  up  by  the  reed ;  but  in  linen,  from  the  want  of  that  elasticity,  a  thread  so 
situated  would  break,  and  by  crossing  some  others  cause  them,  if  not  to  be  broken 
direct  by  that  circumstance,  at  all  events  cause  an  obstruction  to  the  shuttle  that  would 
lead  to  further  mischieC  Hence  it  was  most  material  in  linens  to  have  such  a  method 
of  winding  the  yarns  upon  the  warp  beams  that  should  insure  the  greatest  regularity ; 
but  strange  to  say,  that  point,  though  now  attained,  was  at  first  wholly  lost  sight  of. 
That  circumstance,  as  well  as  the  great  mistake  of  attempting  to  use  the  same  looms  as 
are  found  suitable  for  cotton,  produced  so  much  discouragement  in  the  earlier  attempts 
as  to  give  rise  to  a  high  degree  of  prejudice  against  the  possibility  of  success  in  this 
undertaking,  which  may  account  for  the  backwardness  ^in  which  this  branch  of  the 
flax  manufacture  was  found  till  quite  recently.     See  article  Flax  Weaving  Loom. 

The  new  roving  machine,  called  by  the  ingenious  inventor,  Mr.  W.  K.  Westley,  of 
Leeds,  the  Sliver  Roving  Frame,  seems  to  be  a  philosophical  induction  happily  drawn 
from  the  nature  of  the  material  itself,  and  accommodated  to  its  peculiar  constitution. 
It  is  remarkable  for  the  simplicity  of  its  construction,  and,  at  the  same  time,  for  its 
comprehensiveness ;  requiring  no  nicety  of  adjustment  in  its  application,  and  no  tedi- 
ous apprenticeship  to  be  able  to  work  it. 

It  18  known,  that  the  glutinous  matter  of  the  plant  may  be  softened  by  water,  and 
hardened  again  by  heat ;  of  this  fact  advantage  is  taken,  in  order  to  produce  a  roving 
wholly  without  twist ;  that  is,  in  the  form  of  a  ribbon  or  sliver,  in  which  the  fibres  are 
held  together  by  the  glutinous  matter  which  may  be  natural  to  them ;  or  which  may, 
for  that  purpose,  be  artificially  applied.  The  sliver  roving,  as  long  as  it  remains  dry, 
possesses  all  rec[uisite  tenacity,  and  freely  unwinds  from  the  bobbin,  but  on  becoming 
again  wetted  in  the  spinning  frame,  it  readily  admits,  with  a  slight  force,  of  being 
drawn  into  yam,  preserving  the  fibres  quite  parallel. 

The  diagram,  Jig,  644.,  shows  in  explanation,  that 

a,  is  the  drawing  roller  of  the  roving  frame  in  front  of  the  usual  comb. 

B,  the  pressing  drawing  roller. 

c,  a  shallow  trough  of  water. 

D,  a  cylinder  heated  by  steam. 

E,  a  plain  iron  roller  for  winding. 

F,  a  bobbin  lying  loose  upon  the  winding 

roller,  and  revolving  upon  it,  by  the  friction 
of  its  own  weight. 

The  roving,  or  sliver,  as  shown  by  the 
dotted  line,  after  leaving  the  drawing  rol- 
lers, a,  B,  passes  through  the  water,  in  the 
trough  c,  which  softens  the  gluten  of  the 
fibres ;  and  then  it  is  carried  round  by  the 
steam  cylinder  d,  which  dries  it,  and  de- 
livers it  hard  and  tenacious  to  the  bobbin 
F,  on  which  it  is  wound  by  the  action  of  the 
roller  e. 

This  is  the  whole  of  the  mechanism  re- 
quired in  producing  the  sliver  roving.  All 
the  complex  arrangements  of  the  common 
cone  roving  are  superseded,  and  the  machine 
at  once  becomes  incomparably  more  dur- 
able, and  easier  to  manage;  requiring  only 
half  the  motive  power,  and  occupying  only  half  the  room.  A  frame  of  48  bobbins  is 
only  6  feet  long,  and  affords  rovings  sufficient  to  supply  1200  spinning  spindles. 

This  machine,  though  here  described,  is  but  little  used,  being  capable  of  but  very 
limited  application. 

The  following  sketch  shows  the  arrangement  of  the  machinery  in  the  most  important 
rooms  in  a  modern  flax  mill  of  1000  to  8000  spindles,  capable  of  producing,  weekly, 
about  1900  bundles  of  line  yam,  No.  25.'s  to  120. 's;  and  about  700  bundles  of  tow- 
yam.  No.  10. 's  to  40. 'a. 
There  are  three  systems  of  long  line  machinery  for  No.  26.*b  to  70.*b;  two  systemaof 


FLAX. 


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Vf.^    \^!J-\.:/  ^W>— ^..Xf-  .......jM^^-,;— ^^.;^.«_-g;^^, ^,...j^^,^,>>j—^gjf>^-^;^^ 


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■97mrf. — m\ — jm — >»¥\=:7^i^=m%. — m/^ — f.J/t     lj-a — »>,:x__,,jj\ 1;},^     (^m\     ^^.^^     ff,.^    ^.^^.^^  j»>m,.\ 


cut  line  machinery  for  No.  10. 's  to  120.'s ;  and  three  systems  of  tow  machinery  for  No. 
lO.'s  to  40. 's. 

The  building  is  56  feet  wide  and  162  feet  long;  which  is  a  very  suitable  and  con- 
venient size,  and  which  admits  of  the  most  economical  arrangement  of  the  machinery. 

The  following  is  a  df'scription  of  the  machines  shown  in  the  preparing  room :  — 

A,  A,  two  of  Baxter's  patent  sheet  hackling  machines  for  long  tow. 

B,  a  flax-cutting  machine. 

c,  one  of  P.  Fairbairn  <fe  Co.'s  patent  double  line  of  holder  hackling  machines  for  cut 
line. 

D,  D,  are  two  breaker  cards  4  feet  diameter  X  6  feet  wide. 

E,  lap  machine. 

F,  F,  F,  are  three  finisher  cards  4  feet  diameter  X  6  feet  wide,  with  P.  Fairbairn  ife 
Co.'s  patent  rotar}^  gill  drawing  heads  attached. 

6,  G,  are  two  patent  rotary  gill  drawing  frames  for  long  tow,  12  slivers  each. 
H,  II,  two  ditto  regulating  roving  frames  48  spindles  each  for  long  tow. 
I,  is  a  screw  gill  second  drawing  frame  of  3  heads  for  cut  line  tow. 
K,  is  a  screw  gill  third  drawing  frame  of  3  heads  for  cut  line  tow. 
L,  a  screw  gill  regulating  roving  frame  of  72  spindles  for  cut  line  tow. 
M,  M,  M,  are  three  long  line  first  drawing  frames  or  spreaders  of  4  bosses  each. 
N,  N,  N,  are  three  long  line  second  drawing  frames  of  2  heads  each. 
o,  o,  o,  are  three  long  line  third  drawing  frames  of  2  heads  each. 
p,  p,  H,  three  long  line  regulating  roving  frames  60  spindles  each. 
%  Q,  are  two  cut  line  spreaders  of  4  bosses  each. 
R,  R,  two  cut  line  second  drawing  frames  2  heads  each. 
8,  8,  two  cut  line  third  drawing  frames  2  heads  each. 
N,  T,  two  eiitline  regulating  roving  frames  72  spindles  each. 

The  spinning  room  contains  34  spinning  frames  of  184  to  244  spindles  each,  appor- 
tioned to  the  several  systems  as  described  below. 

L  System  of  long  line  machinery  for  spinning  No.  25.'s  to  40. 's. 

1  Baxter's  patent  sheet  hackling  machine,  6  tools. 

1  spreading  or  first  drawing  frame,  4  bosses. 

1  second  drawing  frame,  2  heads  4  bosses  each. 

1  thii*d  drawing  frame,  2  heads  6  bosses  each. 

1  patent  disc  regulating  roving  frame  60  spindles,  10  spindles  per  head,  8  incheg 
X  4  inches  bobbin. 

5  spinning  frames  2f  inches  pitch,  200  spindles  each,  1000  spindles. 
The  production  of  this  system  is  about  66  bundles,  or  say,  420  lbs.  of  No.  SO.'syam 

per  day. 
IL  Two  systems  of  long  line  machinery  for  No.  40. 's.  to  70. 's. 

1  Baxter's  patent  sheet  hackling  machine,  8  tools. 

2  spreaders  or  first  drawing  frames  4  bosses  each. 
2  second  drawing  fi-ames,  2  heads  of  6  bosses  eacli. 
2  third  drawing  frames,  2  heads  of  8  bosses  each. 

2  patent  disc  regulating  roving  frames,  60  spindles  each,  12  spindles  per  head,  6 

inches  X  3^  inches  bobbin. 
10  spinning  frames,  220  spindles  each,  2^  inches  pitch,  2200  spindles.     Production 

about  130  bundles,  or  472  lbs.  of  No.  65. 's  yarn  per  day. 

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III.  Two  systems  of  three  cut  line  machinery  for  No.  40.'8  to  120/9  (one  for  40.*8  to 
70. 'a,  and  one  for  70. 's  to  120.'8). 

1  flax  cutting  machine. 

1  P.  Fairbairn  <fe  Co.'s  patent  double  line  of  holder  hackling  machine. 

2  spreaders  or  first  drawing  frames  4  bosses  each. 

2  second  drawing  frames,  2  heads  each,  6  slivers  per  head. 

2  third  drawing  frames,  2  heads  each,  8  slivers  per  head. 

2  patent  disc  regulating  roving  frames,  72  spindles  each,  12  spindles  per  head, 

6  X  3i  inches  bobbin. 
5  spinning  frames  220  spindles  each,  1\  inches  pitch,  =  1100  spindles. 
5  spinning  frames  244  spindles  each,  2^  inches  pitch,  =  1220  spindles. 
Production  about  65  bundles  or  236  lbs.  of  No.  SS.'s  yarn  per  day,  and  about  60 

bundles  or  105  lbs,  of  No.  95.'8  jam  per  day. 

IV.  Two  systems  of  long  tow  machmery  for  No.  10. 's  to  25.'8. 

1  breaker  card  4  feet  diameter  6  feet  wide,  doffed  by  rollers. 

1  lap  machine. 

2  finisher  cards  4  feet  X  6  feet  with  P.  Fairbairn  <fe  Co.'s  patent  rotary  gill  draw- 
ing frames  attached. 

2  patent  rotary  gill  drawing  frames  12  slivers  each. 

2  patent  rotary  gill  disc  regulating  roving  frames,  48  spindles  each,  8  inches  X  4 
inches  bobbin. 

8  spinning  frames,  184  spindles  each,  3  inches  pitch  for  No.  lO.'s  to  18.'8  =  552 
spindles. 

3  spinning  frames  200  spindles  each,  2f  inches  pitch  for  No.  IC's  to  25.'8  =  600 
spindles. 

Production  about  39  bundles,  or  488  lbs.  No.  IC.'s  per  day,  and  about  39  bundles, 
or  312  lbs..  No.  25,'s  per  day. 

V.  One  system  of  cut  tow  machinery  for  No.  25. 's  to  40.'8. 

1  Breaker  card  4  feet  diameter  6  feet  wide,  doffed  by  combs. 

1  Finisher  card  with   P.   Fairbairn   <fe    Co.'s  patent  rotary  gill  drawing  frame 

attached. 
1  Screw  gill  second  drawing  frame  3  heads  each,  4  bosses  per  head. 
1  Screw  gill  third  drawing  frame  3  heads  each,  6  bosses  per  head. 
1  Screw  gill  patent  disc  regulating  roving  frame  72  spindles,  12  spindles  per  head, 

6  X  3|-  inches  bobbins, 
3  spinning  frames  of  220  spindles  each  ;  2^  inches  pitch,  =  660  spindles. 
Production  about  36  bundles,  or  240  lbs.  of  No.  30. 's  per  day. 
The  reeling  is  generally  carried  on  in  the  attic  above  the  spinning  room,  and  the 
number  of  reels  required  is  about  the  same  as  the  number  of  spinning  frames. 

Summary   view. 

There  are  3200  spindles  long  line,  producing  196  bundles,  or,  890  lbs.  of  yam  per  day. 

1152   „    long  tow,    „    78    ,,800      „ 

2320   „    3  cut  line,    „    115     „     340       „ 

660   „     cut  tow,    „     36     „     240       „ 

7332  spindles  425  bundles       2270  lbs,  of  yam  per  day. 

The  waste  in  line  spinning  is  generally  about  10  per  cent,  and  in  tow  spinning  about 

25  per  cent.,  so  that  the  quantity  of  raw  flax  required  to  produce  the  above  stated 

quantity  of  yarn  would  be  about  20  cwts.  of  flax  for  long  line  and  long  tow  spinning, 

and  about  6  cwts.  of  flax  for  cut  line  and  cut  tow  spinning. 


Clausxcn'i  Patent  Process. — ^The  great  interest  which  has  of  late  been  excited  in 
the  public  mind  with  respect  to  flax,  in  part  by  the  enlarged  sphere  of  application  which 
is  supposed  to  be  opened  out  to  it  by  the  discoveries  of  Mr,  Claussen,  and  more  par- 
ticularly from  the  fact,  that  it  is  a  material  of  home  growth,  and  capable  of  production 
in  unlimited  quantities  in  Ireland,  would  seem  to  demand  from  us  special  comment 
We  are  not  the  less  inclined  to  this  course,  as  the  public  is  ever  ready  to  take  upon 
trust  the  practicableness  of  any  new  projects,  when  their  promised  results  chime  in 
with  any  feeling  of  sympathy  which  happens  to  pervade  the  community ;  thus  where 
the  interest  of  Ireland  is  concerned,  we  find  that  commercial  schemes  for  aiding  its  ad- 
vancement are  eagerly  seized  upon,  and  confided  in  almost  without  inquiry ;  but  this 
is  far  from  a  prudent  course.  There  can  be  no  question  that  the  flax  trade  is  the 
growing  manufacture  of  Ireland,  and,  as  such,  too  much  attention  cannot  be  given  to 
the  production  of  the  raw  material ;  it  has  therefore  been  encouraged  in  every  legiti- 
mate way,  but  it  may  be  questioned  whether  the  late  announcements  which  have 
been  made  of  its  almost  universal  applicability  to  textile  fabrics,  will  not  tend  to 
direct  capital  to  too  great  an  extent  into  this  now  thriving  branch  of  industry,  and 
therebv'  quickly  induce  a  false  and  ruinous  competition  between  manufacturers. 

Flax,  though  apparently,  from  its  fibrous  character,  better  suited  b}'  nature  than 
either  cotton  or  wool  to  be  formed  into  thread,  nevertheless  presents  many  difficulties  to 
manufacturers,  which  are  quite  foreign  to  the  working  of  these  short  staples,  and  which 
can  only  be  in  part  remedied  by  the  adoption  of  a  somewhat  different  process  of  manu- 
facture. In  contradistinction  to  cotton,  wliich  may  be  considered  the  fruit  of  the  plant, 
flax  is  the  filamentous  substance  contained  in  the  stalk  of  the  plant.  It  has  therefore 
to  be  obtained  from  stripping  oflF  the  bark  or  woody  coating,  termed  the  "boon." 
But,  in  order  to  eff^ect  this,  as  well  as  to  detach  the  fibres  from  each  other,  it  is 
necessary  to  dissolve  the  gum  or  resinous  sap,  which  pervades  the  plant  and  binds 
the  several  parts  together.  Various  plans  have  been  suggested  for  attaining  this 
end ;  and  it  is  upon  the  efficiency  of  the  process  adopted  that  the  ultimate  suct-ess 
of  the  flax  trade  mainly  depends.  When  it  is  understood  that  the  growth  of  the 
flax  plant  is  principally  in  the  hands  of  small  farmers  without  capital,  and  that  the 
bulk  of  the  flax,  when  reaped,  is  so  disproportionate  to  the  yield  for  manufacturing 
pui-poses  as  to  preclude  the  removal  of  the  article  to  any  great  distances  in  the 
state  of  straw,  it  will  readily  be  seen,  that  no  process  of  dissolving  the  gum  or  of 
"retting"  as  it  is  termed — requiring  the  purchase  of  expensive  apparatus,  or  de- 
manding the  exercise  of  scientific  knowledge — can  be  brought  into  general  use, 
however  efficient  that  process  may  prove  to  be.  It  cannot  therefore,  be  wondered  at 
that  the  old  plans  of  water-retting  and  dew-retting  still  prevail,  although  a  far 
superior  method,  which  we  shall  presently  explain,  has  been  introduced. 

Retting  is  simply  bringing  the  plant  to  a  certain  stage  of  decay,  which  causes  a  per- 
fect loosening  or  separation  of  its  fibres.  In  carrying  out  the  water-retting  process  pits 
are  dug  in  the  ground  and  filled  with  water,  and  the  flax  is  thrown  in  in  bundles  and 
pressed  down  by  weighted  boards,  to  keep  it  under  water.  After  a  short  time,  fermen- 
tation commences,  and  in  about  ten  days  (more  or  less,  according  to  the  mean  tempd- 
rature)  the  decaying  process  will  have  proceeded  sufficiently  far ;  the  flax  is  then  taken 
out  and  dried,  and  the  boon  is  removed  by  hand.  The  retting  may  be  carried  on  in 
either  mnning  or  stagnant  water;  but  the  latter,  although  the  more  expeditious  method, 
requires  closer  watching,  to  prevent  the  flax  from  losing  its  strength  of  fibre  by  oyer 
decay.  It  will  be  obvious  that  large  masses  of  vegetable  matter  exposed  to  putrefaction 
must  generate  such  exhalations  as  are  very  injurious  to  the  health  of  the  community. 
Yet  this  practice  not  only  prevails,  but  will,  as  we  think,  necessarily  increase  in  propor- 
tion to  the  increase  in  the  growth  of  the  plant,  unless  some  energetic  means  are  adopted 
to  put  down  the  practice*.  Dew-retting  is  a  process  that  is  less  objectionable,  but  its 
operation  is  far  slower,  and  it  is  altogether  beyond  the  means  of  many  farmers  to  adopt. 
In  this  instance  the  flax  is  strewn  thinly  over  meadow  or  grass  land,  and  then  submitted 
to  the  action  of  the  air,  dews,  and  rain,  which,  in  a  period  varying  (according  to  the 
mean  temperature)  between  three  and  six  weeks,  will  effect  the  required  disunion  of  the 
plant  This  plan  has  an  advantage  over  the  water-retting,  inasmuch  as  the  flax  is 
yielded  of  a  brighter  colour, — the  latter  process  being  very  apt  to  impart  a  deep  stain 
to  the  fibres,  as  well  as  to  destroy  their  tenacity. 

The  improved  plan  of  retting,  above  alluded  to,  was  introduced  into  Ireland  from 
the  United  States  in  1847,  by  Mr,  Schenck  of  New  York,  It  had  been  tried  there  suc- 
cessfully on  hemp ;  the  strength  of  the  fibre,  when  made  into  cables,  having  been  proved 
in  some  of  the  government  navy  yards  to  exceed  any  that  had  been  retted  on  the  old 
system.  The  process  was  patented  in  the  United  Kingdom  in  1846,  and  is  now  in 
profitable  work  near  Belfast  A  recent  inspection  of  the  factory  will  enable  us  to 
state  in  detail  the  manner  of  proceeding  to  separate  the  long  fine  fibres  of  the  flax  from 
the  boon.    The  principal  apartment  in  the  building  contains  a  number  of  large  circular 

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vats,  in  which  the  flax  is  steeped,  and  these  are  provided  with  steam-pipes  connected  to 
the  steam  engine  boiler.    The  flax  to  be  operated  upon  is  placed  in  these  vats  and  piled 
np  to  a  given  height ;  strong  cross-bars  of  wood,  forming  a  kind  of  framework,  are  then 
laid  above  the  flax  and  secured  to  the  respective  vats, — the  object  of  this  framing  being 
to  keep  the  flax  down  in  the  vat»  as  otherwise  it  would  rise  as  it  swelled  in  fermenting, 
and  protrude  above  the  water.    When  a  mass  of  flax  is  thus  secured,  water  is  run  into 
the  vats,  and  as  it  becomes  absorbed,  more  water  is  added.   Steam  is  now  admitted  into 
and  made  to  circulate  through  the  steam-pipe  at  the  bottom  of  the  vat,  so  as  to  raise  the 
water  to  about  90**  Fahr.,  and  maintain  it  at  that  temperature.    In  a  few  hours  acetous 
fermentation  is  established  in  the  vat,  and  the  decomposition  of  the  resinous  or  gummy 
matter  in  the  stalk  proceeds  with  rapiditj.     After  about  sixty  hours  the  decomposition 
is  completed,  and  that  without  the  exudation  of  any  inodorous  or  noxious  eflluvium.    The 
water  surcharged  with  the  mucilage  is  then  drawn  off",  the  framing  is  removed,  and  the  flax 
is  taken  out  of  the  vat  to  be  dried,  either  in  the  open  air  or  by  artificial  means.   Thus, 
not  only  is  the  objection  to  the  old  plan,  on  the  score  of  injury  to  health,  removed,  but 
a  considerable  economy  in  point  of  time  is  efi^ected;  the  flax  also  is  less  liable  to  dete- 
rioration in  colour  and  strength  of  fibre,  if  ordinary  care  is  used  in  conducting  the  opera- 
tion.    When  the  weather  is  favourable  for  drying  in  the  open  air,  the  flax,  tied  up,  in 
tufts  or  handfuls,  is  suspended  in  rows  tier  above  tier,  in  an  open  framing,  covered  in  at 
top  by  a  penthouse  roof.    This  mode  of  packing  admits  of  a  large  quantity  of  flax  being 
stowed  in  a  small  compass,  and  yet  allows  of  a  free  access  of  air  through  the  whole  mass. 
When  it  has  hung  a  sufficient  time  to  dry,  it  is  next  submitted  to  the  scutching  operation. 
Or,  instead  of  open  air  drying,  the  flax,  in  damp  weather,  is  piled  loosely  m  a  drying 
chamber,  into  which  a  current  of  air,  heated  after  Messrs.  Davison  <fe  Symington's 
method,  is  passed,  and  the  moisture  is  quickly  expelled.     The  cost  of  this  operation,  as 
carried  on  at  the  works,  must  be  verj^  trifling,  as  the  waste  steam  from  the  engine, 
which  works  on  the  high-pressure  principle,  is  found  amply  sufficient  for  heating  the 
air ;  an  advantage  consequent  on  this  mode  of  heating  is,  that  no  carelessness  on  the 
part  of  the  attendants  will  render  the  air  liable  to  be  heated  to  an  extent  that  would  in- 
jure the  flax.     The  flax  having  been  retted  and  dried,  is  next  carried  to  the  rolling  or 
crushing  mill,  and  there  passed,  by  hand,  between  rotating  horizontal  rollers,  which 
crack  the  boon  already  loosened  by  the  retting  process,  and  spread,  or  partially  separate, 
the  long  fibres.     The  flax,  as  it  is  delivered  out  of  the  machine,  is  gathered  up  by  boys, 
and  handed  to  others,  who  submit  it  by  handfuls  to  the  action  of  rotating  knives.    These 
knives  are  attached  to  the  face  of  a  vertical  wheel,  several  of  which  are  mounted  on  one 
and  the  same  shaft,  at  about  three  feet  apart,  and  receive  motion  from  the  engine. 
There  is  an  attendant  stationed  at  every  wheel,  whose  duty  is  to  submit  the  flax  to  the 
action  of  the  knives,  by  holding  it  over  a  fixed  bar,  contiguous  thereto,  and  allowing  the 
rotating  knives  to  strike  the  flax  in  the  direction  of  its  length.     When  the  boon  on  the 
half  length  of  the  flax  is  broken  away  or  knocked  off",  the  flax  is  turned  over  and  the 
other  end  is  subjected  to  similar  treatment.   To  further  clear  the  flax  of  the  woody  par- 
ticles, it  is  again  submitted  to  a  similar  operation  before  another  set  of  wheels, — the 
action  of  the  knives  being,  in  this  instance,  more  thorough  and  searching,  as  the  flax 
has  now  approached  nearer  to  a  stick  of  fine  fibres.    Having  undergone  this  treatment, 
the  flax  is  now  ready  for  sale  in  the  market ;  and  it  is  in  this  state  that  it  enters  the 
flax  mill  to  be  acted  upon  by  the  heckling-machine,  for  the  removal  of  the  tow  or  short 
staple,  prior  to  undergoing  the  various  operations  of  preparing  and  spinning,  to  convert 
it  mto  yarn.     From  this  description,  it  will  be  understood,  that,  so  long  as  the  cul- 
tivation of  flax  is  in  the  hands  of  small  farmers,  Mr.  Schenck's  process  is  not  likely  to 
put  the  old  practice  out  of  use ;  for  the  water-retting  is  carried  on  at  little  or  no  outlay 
of  money ;  and  the  cleaning  of  the  flax  by  hand  is  made  a  sort  of  wet-day  occupation : 
the  bulk  of  the  flax  in  the  state  of  dry  straw, — which,  as  we  have  before  said,  is  so 
disproportionate  to  the  amount  of  useful  fibre  as  virtually  to  prevent  its  carriage  to  any 
distant  part  prior  to  undergoing  the  retting  operation — scarcely  exceeds,  when  carried 
to  the  market,  20  per  cent,  of  its  original  weight 

M.  Claussen's  patented  process  (the  merits  of  which  have  been  so  confidently  paraded), 
does  not  seem  to  be  in  favour  with  the  Irish  flax  spinners,  although  the  specimens  con- 
tained in  the  Exhibition  appeared  to  the  eye  to  realize  everything  that  could  be  wished : 
but  here,  as  in  many  other  manufactures,  it  is  not  the  attainment  of  a  high  degree  of  ex- 
cellence that  is  the  diflSculty,  but  the  cost  at  which  such  a  result  may  be  arrived  at. 
Thus  flax  may  be  dressed  from  the  straw,  as,  indeed,  it  was  once  proposed  to  be  done, 
without  being  subjected  to  the  retting  process.  The  waste  of  material,  however,  soon 
showed  the  impracticability  of  the  plan,  although  a  good  article  was  produced ;  it  is 
possible,  therefore,  that  M.  Claussen's  specimens  may  have  been  obtained  without  regard 
to  cost.  We  do  not  assert  this  as  a  fact  but  rather  to  show,  that  in  commercial  matters 
no  just  conclusions  can  be  arrived  at  without  the  question  of  cost  being  taken  into 
account     His  mode  of  treating  the  flax  will  be  readily  understood  from  the  following 


description,  which  we  have  compiled  from  his  specification.  The  straw,  having  been 
stripped  of  its  seeds,  is  steeped  in  a  solution  of  caustic  alkali,  of  about  the  strength  of  l® 
Twaddle's  hydrometer,  either  in  a  boiling  state,  which  renders  an  immersion  of  six 
hours  sufficient,  or  at  a  temperature  of  150°  Fahr.,  which  will  necessitate  the  continu- 
ance of  an  immersion  for  about  twelve  hours.  By  this  means  the  glutinous  matters, 
which  connect  the  fibres  with  the  woody  portions  of  the  plant,  are  dissolved,  and  the 
colouring  matters  contained  in  the  straw  are  discharged  and  prevented  from  staining  the 
fibres.  When  the  flax  is  required  to  be  spun  in  long  staple,  the  straw  is  next  steeped 
for  about  two  hours  in  dilute  sulphuric  acid,  containing  one  part  of  acid  to  from  two  to 
five  hundred  parts  of  water,  for  the  purpose  of  ridding  it  of  the  alkali  which  it  has  taken 
up ;  the  straw  is  then  removed  from  the  acid-bath  and  well  washed  in  water :  this  is  one 
process.  But  the  one  which  has  raised  the  public  curiosity,  is  that  which  purports  to 
split  the  fibres  into  fine  filaments  like  those  of  cotton  or  wooL  This  operation  is 
etfected  as  follows  : — ^The  straw  is  put  into  a  bath  containing  a  strong  solution  of 
bicarbonate  of  soda,  and  allowed  to  remain  there  for  three  or  four  hours.  When  well 
saturated  with  the  bicarbonate,  it  is  immersed  in  water,  acidulated  with  sulphuric  acid, 
in  the  proportion  of  one  part  of  acid  to  two  hundred  parts  of  water ;  the  sulphuric  acid 
will  then  combine  with  the  soda  and  effect  the  disengagement  of  carbonic  acid  gas  in  the 
fibrous  tubes,  which  gas,  by  its  expansive  force,  will  split  the  fibres  into  fine  filaments, 
having  the  appearance  of  fine  cotton  wool,  and  capable  of  similar  treatment  This  split- 
ting process  may  be  applied  to  the  plant  either  in  the  state  of  straw,  or  after  it  has  been 
retted  and  brought  to  the  state  of  long  fibre  ;  and  it  is  therefore  capable  of  general 
application,  as  far  as  the  inconvenience  arising  from  bulk  is  concerned.  What  manufac- 
turers will  eventually  say  to  working  up  fibres  that  have  been  steeped  in  sulphuric  acid, 
may  depend  upon  the  means  taken  to  extract  this  corroding  substance  from  the  flax ;  but 
at  present  we  think  there  is  a  strong  feeling  against  its  use. 

Mr.  Claussen's  patent  process  for  treating  flax  is  described  as  follows,  in  his  specifica- 
tion of  March,  1851 : —  .  . 

"  1.  My  said  invention,  in  so  far  as  respects  improvement  in  bleaching,  has  reference 
to  the  bleaching  of  all  kinds  of  vegetable  productions,  and  of  fabrics  or  articles  com- 
posed of  such  productions,  and  consists  of  the  following  improved  processes.  In  the 
usual  methods  of  bleaching  fabrics,  such  as  calico,  the  goods  are  first  immersed  in 
a  bleaching  liquor  (commonly  the  solution  of  hypochlorite  of  lime,  '  the  chloride  of 
lime'  of  commerce),  and  then  are  steeped  in  a  bath  of  water,  acidulated  with  sulphuric 
acid.  By  this  plan,  the  chlorine  is  set  free,  either  in  its  simple  form,  or  in  combination 
with  oxygen  (as  chlorous  or  hypochlorous  acids),  or  in  chemical  union  with  the 
hydrogen  of  the  water  (as  hydrochloric  acid),  and  thus  either  is  wasted,  by  its  escape, 
or  is  rendered  injurious  to  the  fabric,  bv  remaining  too  long  in  contact  with  it 

"  Now  instead  of  this  I  adopt  the  following  process,  whereby  the  whole,  or  a  great 
portion  of  the  chlorine,  or  chloro-compound,  is  kept  in  a  combined  state,  and  recovered 
for  further  use.  By  the  term  '  chloro-compound,*  I  do  not  mean  a  salt  containing 
*  chlorine,'  but  an  acid  having  '  chlorine'  for  its  base,  such  as  chlorous  or  hypo- 
chlorous  acid-  ,      <.        1       1  J    1.         1 

"  In  this  process,  then,  of  bleaching,  I  take  the  goods,  after  they  have  passed  through 
the  bleaching  liquor  (say  a  solution  of  the  hypochlorite  of  lime),  and  then  steep  them 
in  a  strong  solution  of  some  salt  whose  acid  has  a  more  powerful  affinity  for  lime  than 
hypochlorous  acid ;  thus  a  strong  solution  of  sulphate  of  magnesia  may  be  employed, 
the  sulphuric  acid  of  which,  having  a  strong  affinity  for  lime,  combines  with  the  earthy 
base  of  the  bleaching  salt  above-mentioned,  and  forms  sulphate  of  lime,  and  the  chloro- 
compound  being  thus  liberated  unites  with  the  magnesia  of  the  sulphate  of  magnesia, 
and  forms  a  new  salt  (hypochlorite  of  magnesia),  having  bleaching  properties  similar  to 

the  lime-salt  first  employed.  ,.,,..  . 

"  This  newly  formed  compound  may  be,  m  the  next  instance,  used  as  a  primary 
bleaching  agent  and  may  again  be  subjected  to  the  process  of  double  decomposition,  as 
in  the  foregoing  example.  Thus,  the  goods  having  been  exposed  to  the  action  of 
hypochlorite  of  magnesia  in  solution,  may  then  be  steeped  in  a  liquid  holding  in  solution 
some  carbonate  or  other  salt^  for  whose  base  the  hjrpochlorous  acid  has  a  greater  affinity 
than  for  the  magnesia.  In  such  a  case,  the  carbonic  acid  having  also  a  strong  attraction 
for  the  magnesia,  combines  with  it,  to  form  a  carbonate  of  that  earth,  and  the  liberated 
chloro-compound,  instead  of  escaping,  or  remaining  so  long  in  contact  with  the  goods 
as  to  injure  them,  combines  with  the  base  of  the  carbonate  employed  to  produce  de- 
composition, and  forms  a  new  salt,  having  bleaching  properties.  This  salt  may  also 
be  brought  under  the  same  laws  of  double  decomposition,  as  exemplified  before,  and  with 

similar  results.  .       .  ,    j  i  u       ^      c 

"  Thus,  if  the  carbonate  employed  in  the  foregoing  instance  had  been  carbonate  of 

barytes,  and  a  solution  of  sulphate  of  magnesia  or  of  lime  were  brought  into  contact 

with  the  resulting  chloro-compound  salt  of  barytes,  a  precipitate  of  the  base,  as  a 


** 


782 


FLAX. 


ulphate  of  barytes,  will  take  place,  and  the  chloro-compounds  will  unite  with  the  lime 
or  magnesia,  to  form  a  bleaching  salt 

"  I  would  mention,  however,  that,  in  bleaching  flax,  or  other  like  vegetable  material 
for  making  linen,  no  compounds  should  be  used  which  are  likely,  during  their  decom- 
position, to  evolve  any  gaseous  matters,  such  as  carbonic  acid  or  chlorine,  as,  by  their 
development  and  expansion  in  the  fibrous  tubes,  the  flax,  or  any  similar  material,  would 
be  rendered  not  so  fit  for  spinning  with  the  ordinary  flax  spinning  niachinery ;  but  in 
bleaching  flax,  or  any  similar  material  which  is  to  be  combined  with  other  materials 
for  spinning  and  feltmg,  according  to  my  invention,  compounds  evolving  gas  may  be 
safely  used,  as  I  shall  hereafter  more  fully  specify  and  explain. 

"  For  the  purpose  of  bleaching  by  the  method  of  double  decomposition,  I  do  not 
confine  myself  to  the  compounds  already  mentioned  as  examples,  nor  to  any  particular 
salts  or  class  of  salts ;  but  I  claim  a  right' to  use  salts,  which,  when  placed  under  the  like 
circumstances,  as  before  exemplified  in  the  case  of  goods  treated  by  the  hypochlorite  of 
lime  and  the  sulphate  of  magnesia,  will  be  subject  to  the  same  chemical  law  of  decom- 
position, and  will  produce  the  same  result.  However,  I  may  particularise  as  among  the 
salts  suitable  for  decomposing  the  chloro-compounds,  or  assisting  themselves  in  the 
process  of  bleaching,  the  carbonates  (such  as  the  carbonate  or  bicarbonate  of  soda), 
sulphates  (as  sulphate  of  magnesia,  Ac),  nitrates  (as  nitrate  of  soda,  Ac),  acetates 
(as  acetates  of  potash  and  of  lead,  &c.\  prussiates  (as  prussiates  of  potash,  <fec.), 
chromates  (as  chromate  and  bichromate  of  potash,  <fec.),  tartrates  (as  tartrate  and 
bitartrate  of  potash,  <fec.) ;  but  I  repeat  that  I  do  not  confine  myself  to  these,  which  are 
merely^  given  as  examples. 

"  Another  mode  of  bleaching  which  I  sometimes  employ,  and  which  is  especially 
applicable  to  goods  composed  of  both  animal  and  vegetable  fibre,  is  as  follows : — I  take 
the  goods,  after  they  have  been  steeped  in  any  of  the  ordinary  bleaching  liquors,  such 
as  the  solution  of  hypochlorite  of  lime  (chloride  of  lime),  and  while  they  are  still  wet^ 
I  expose  them  to  the  fumes  of  sulphur,  slowly  burning  in  a  suitable  chamber  or  stove. 
In  this  case,  I  have  two  powerful  bleaching  agents  at  work,  viz.,  the  hj'poehlorite  com- 
pound, and  the  sulphurous  acid  produced  by  the  combustion  of  the  sulphur.  A 
portion  of  the  sulphurous  acid  combines  with  the  base  of  the  chloro-compound  salt,  to 
form  a  sulphate  of  lime  or  magnesia,  as  the  case  may  be,  and  a  small  portion  of 
sulphuric  acid  may  also  in  this  case  be  formed,  which,  with  the  earth  or  base,  would 
form  a  sulphate.  In  this  way  the  chlorine,  or  chloro-compound,  remaining  in  the 
wetted  goods  is  liberated,  and  allowed  to  act  freely  upon  the  articles  to  be  bleached. 
In  this  last  method  of  bleaching  I  have  ascertained  that  there  may  be  occasionally 
substituted  for  the  ordinary  and  known  bleaching  liquids  certain' chromates,  man- 
ganates,  and  hypermanganates,  <fec. 

"Secondly.  My  improvements  in  the  preparation  of  materials  for  spinning  and  felting 
have  special  relation  to  flax  and  hemp,  and  other  plants,  to  which  the  same  may  be 
applicable :  and  the  processes  I  use  to  prepare  the  same,  though  possessed  of  some 
features  common  to  the  whole,  vary  according  to  the  purposes  to  which  the  fibre 
obtained  from  the  said  materials  is  to  be  applied,  that  is  to  say,  according  as  the  fibre  is 
required  to  be  long  or  short,  fine  or  coarse,  and  the  machinery  in  which  it  is  to  be  spun 
is  adapted  to  the  spinning  of  one  or  other  sort  of  fibre.  By  the  term  ♦  fibre,'  as  used 
throughout  the  specification,  I  mean  that  portion  of  each  plant  which  is  capable  of 
being  spun  or  felted  ;  and  my  invention  applies  to  the  'fibre'  surrounding  the  stems 
of  dicotyledonous  plants,  and  to  that  existing  in  the  stems  and  leaves  of  monocotyle- 
donous  plants. 

"  In  the  following  exemplifications  of  my  improved  modes  of  preparation,  I  shall 
throughout  suppose  flax  or  hemp  to  be  the  material  operated  upon. 

"  If  1  have  to  deal  with  the  plant  from  the  time  of  its  being  first  cut  down  or  pulled 
for  use,  I  take  it  in  the  state  of  straw  (after  the  seed  had  been  stripped  from  it),  and 
subject  it  to  the  following,  which  I  call  my  'primary  process' : — 

"I  first  steep  the  straw  in  a  solution  of  a  caustic  alkali  of  about  1°  of  Twaddle's 
hydrometer,  and  for  such  a  length  of  time  as  may  be  most  convenient.  If  despatch  is 
required,  I  use  the  solution  in  a  boiling  state  ;  in  which  case  an  immersion  of  about  six 
hours  is  sufficient.  If  more  time  can  be  conveniently  allowed,  I  employ  a  solution  of  a 
temperature  of  about  150°  Fahr.,  and  prolong  the  immersion  for  about  twelve  hours ; 
and  oo  in  proportion  to  the  degree  of  temperature.  The  solution  may  be  even  used  at  a 
lower  temperature,  with  a  corresponding  prolongation  of  time,  but  in  no  case  need  tha 
immersion  exceed  a  couple  of  days  at  the  utmost 

"The  object  of  the  preceding  treatment  is  two-fold: — first  to  decompose,  dissolve,  of 
remove  (more  or  less,  as  required),  the  glutinous,  gummy,  or  other  matters,  which 
connect  the  fibre  with  the  woody  portions  of  the  plants;  and  second,  to  discharge  or 
decompose  any  oleaginous,  colouring,  or  extraneous  matter  contained  in  the  straw,  with- 
out allowing  the  matters  so  discharged  to  stain  the  fibre  ;  and  these  results  are  obtained 


FLAX. 


783 


by  the  action  of  the  alkaline  solution.  In  the  preceding  mode  of  preparing  vegetable 
materials,  I  generally  use  a  solution  of  caustic  soda;  but  other  alkaline  liquors  will 
answer  the  purpose, — such  as  a  solution  of  caustic  potash,  or  of  lime  dissolved  in  or 
diffused  in  water,  or,  indeed,  any  substance  having  the  like  power  of  removing,  dis- 
charging, or  decomposing  the  colouring,  glutinous,  gummy,  or  other  foreign  matters 
contained  in  the  straw,  and  which  would  interfere  with  the  whiteness  of  the  fibre,  or 
with  its  ready  separation  and  manufacture. 

"  If  the  fibre  is  required  to  be  long,  like  that  now  commonly  spun  in  flax  machinery, 
I  subject  the  straw  to  a  second  process,  for  the  purpose  of  getting  rid  of  any  of  the 
alkali  still  adhering  to  the  straw  or  fibre,  and  for  the  purpose  of  completing  (if  neces- 
sary) the  removal  of  any  glutinous,  gummy  colouring,  or  extraneous  matters. 

"To  this  end  I  will  take  the  straw  from  the  alkaline  solution,  and  steep  it  for  about 
two  hours  in  water  acidulated  by  sulphuric  acid,  in  the  proportion  of  about  one  part 
of  the  acid  to  from  two  to  five  hundred  parts  of  water.  Some  other  dilute  acids  will 
also  answer  this  purpose,  such  as  dilute  muriatic  acid,  <fec. ;  but  sulphuric  acid  is  to  be 
preferred.  Or,  I  transfer  the  straw,  while  yet  wet  with  the  alkaline  solution,  to 
a  suitable  chamber  or  stove,  where  I  subject  it  to  the  action  of  sulphurous  acid,  or  the 
fumes  produced  by  the  slow  combustion  of  sulphur.  In  both  cases,  the  acid  combines 
with  any  free  alkali  remaining  on  the  straw  or  fibre,  to  form  a  sulphite  or  sulphate, 
according  to  the  acid  employed ;  while  an  excess  of  either  sulphuric  or  of  sulphurous 
acid  will  complete  the  decomposition,  discharge,  or  removal  of  the  glutinous,  colouring, 
and  other  matters. 

"  I  next  remove  the  straw  from  the  acid  bath,  or  sulphur  chamber  or  stove,  and  wash 
or  otherwise  treat  it  with  water,  till  all  soluble  matters  are  removed. 

"  If  the  fibre  is  required  to  be  discolorised,  the  straw  may  now  be  exposed  to  one  of 
the  bleaching  processes  which  I  have  already  described,  or  to  any  of  the  other  knowD 
bleaching  processes.  It  may  then  be  dried,  and  made  ready  for  breaking  and  crushing, 
by  the  means  ordinarily  followed  in  the  manufacture  of  long  flax. 

"  I  would  mention  here  that  in  some  cases  it  will  be  found  advantageous  to  pass  the 
straw  between  rollers,  or  to  break  it  roughly  or  partially,  before  subjecting  it  to  the 
process  above  described,  for  the  purpose  of  facilitating  the  action  of  the  chemical 
agents  upon  it 

"  By  the  aforesaid  method,  I  am  enabled  to  remove  from  the  straw  certain  matters, 
which  water  alone  can  discharge.  The  fibre  thus  prepared  is  also  fi-eer  to  heckle,  and 
the  straw  more  easy  to  scutch,  than  fibre  and  straw  treated  in  the  ordinary  way. 
Much  time  and  much  material  are  also  saved ;  while  the  noxious  exhalations  attendant 
upon  the  water-rotting  system  are  wholly  prevented. 

"  If  the  fibre  is  required  to  be  short  so  that  it  may  be  felted  or  carded,  and  adapted  for 
spinning  on  cotton,  silk,  wool,  worsted  or  tow-spinning  machinery,  either  alone  or  in 
combination  with  cotton,  hair,  fur,  silk,  or  shoddy,  I  take  the  fibre,  after  treating  it  by 
the  processes  just  described,  and  divide  it  in  proper  lengths,  by  some  suitable  instru- 
ment or  machine.  I  then  transfer  the  straw  or  fibre  to  a  bath  containing  a  strong 
.  solution  of  bicarbonate,  or  even  carbonate  of  soda,  or  any  other  similar  com- 
pound ;  but  the  first  two  of  these  are  to  be  preferred,  as  most  abounding  in  carbonic 
acid.  In  this  bath  I  allow  it  to  remain  for  about  three  or  four  hours,  during  which 
time  the  fibre  becomes  well  saturated  with  the  salt  I  then  immerse  the  materials, 
impregnated  with  the  solution  of  the  carbonates  before  named,  for  about  a  couple  of 
houi-s  in  water  acidulated  by  sulphuric  acid,  of  about  the  strength  of  one  part  of  acid 
to  two  hundred  parts  of  water.  Or,  instead  thereof,  I  expose  the  saturated  materials^ 
while  wet  to  the  action  of  burning  sulphur  in  a  suitable  chamber  or  stove. 

"  In  this  operation  it  appears  that  a  certain  portion  of  gas  being  developed  in  the 
fibrous  tubes,  splits  and  divides  them  by  its  expansive  power  into  filaments,  having  the 
character  and  appearance  of  fine  cotton  wool ;  in  which  state  they  may  be  dyed  and 
manufactured  like  cotton  or  wool. 

"The  same  means  of  eff^ecting  the  splitting  of  the  fibre  may  of  course  be  employed  in 
the  preparation  of  long  fibre,  and  I  do  not  limit  myself  to  its  use  for  the  preparation  of 
short  fibres  alone,  but  when  the  fibre  is  of  its  original  lengtli,  the  solution  employed 
takes  a  longer  time  to  penetrate  the  interior. 

"  The  decomposition  of  the  bicarbonate  of  soda  or  other  suitable  compound,  with 
which  the  fibre  is  saturated,  may  be  also  effected  by  means  of  electric  ageuc}^,  when  a 
like  evolution  of  gas  and  splitting  up  of  the  fibre  will  take  place. 

"  After  the  fibre  has  been  subjected  to  the  splitting  process,  it  must  be  carefully 
washed  to  remove  all  soluble  matters,  and  then  dried. 

"  The  splitting  process  may  be  applied  to  the  plant  either  in  the  straw  (the  wood  of 
-which  is  to  be  afterwards  removed  by  proper  means  and  machinervX  or  in  the  state  of 
long  fibre,  whether  prepared  by  my  before-described  process,  or  by  any  of  the  usual 
and  known  processes. 

"  Thirdly,  my  invention,  in  so  far  as  it  relates  to  improvements  in  yarns  and  felti^ 


784 


FLAX. 


FLAX. 


785 


fi 


\ 


ii  ! 


consists  in  composing  the  same  of  tlie  following  new  combination  of  materials.  I 
manufacture  a  yarn  which  I  call  'flax  cotton  yarn/  composed  partly  of  flax  fibre 
prepared  and  cut  into  short  lengths,  as  aforesaid  and  partly  of  cotton,  varying  the  pro- 
portions at  pleasure.  This  yarn  is  much  stronger  than  yarn  composed  of  cotton  alone, 
and  also  much  whiter  and  more  glossy,  while  it  is  equally  capable  of  being  spun  in  the 
ordinary  cotton  spinning  machinery. 

♦'  I  also  manufacture  yams  composed  in  like  manner,  partly  of  hemp  fibre  or  of  jute, 
or  of  phormium  tenax,  or  of  other  like  vegetable  fibre  (china  grass  excepted),  prepared 
and  cut  into  short  lengths,  as  aforesaid,  and  partly  of  cotton,  which  yarns  each  possess 
the  same  properties  (more  or  less)  as  the  flax-cotton  yam. 

"I  manufacture  also  a  yarn,  which  I  call  'flax-wool  yam,'  composed  partly  of  flax 
prepared  and  cut  into  short  lengths  as  aforesaid,  or  of  anv  other  like  vegetable  fibre 
(cotton  and  china  grass  excepted)  and  partly  of  wool,  or  of  that  description  of  it  called 
'  tschudy,'  or  partly  of  fur  or  hair,  or  partly  of  any  two  or  more  of  the  said  materials ; 
which  yarn  is  stronger  than  any  yarn  composed  of  wool  alone.  Some  wools  also, 
which  are  too  short  to  be  spun  by  themselves,  may,  by  being  mixed  with  flax  fibre,  cut 
into  short  lengths,  form  a  material  very  suitable  for  spinning. 

"  I  manufacture  also  a  yarn,  composed  partly  of  flax  or  other  like  vegetable  fibre 
(china  grass  excepted),  prepared  and  cut  into  short  lengths,  as  aforesaid,  and  partly  of 
waste  silk,  that  is,  silk  of  the  short  lengths  in  which  it  exbts  before  reeling,  or  silk 
rags  cut  into  short  lengths  and  carded. 

"Lastly,  flax-felts,  of  a  fineness  and  softness  equal  to  the  best  felts  composed  wholly 
of  wool,  and  superior  to  them  in  point  of  durability,  are  also  produced  by  a  mixture 
of  flax  fibre,  prepared  and  cut  into  short  lengths,  as  aforesaid,  with  wool,  fur,  hair  or 
any  other  feltable  material. 

"And  I  declare  that  what  I  claim,  as  secured  to  me  by  the  said  letters  patent,  is  as 

follows: — 

"First,— I  claim  the  method  of  bleaching  by  double  decomposition,  before  described, 
whereby  the  various  bleaching  agents  and  compounds  used  may  be  recovered  and 
economised. 

"Second,— I  claim  the  method  of  bleaching  by  the  combined  action  of  chlorides,  or 
carbonates,  or  chromates,  or  any  other  bleaching  agent^  with  fumes  of  sulphur,  as 
before  described. 

"Third, — I  claim  the  preparing  of  flax  and  hemp,  and  of  all  vegetable  fibre  capable 
of  being  spun  or  felted,  from  whatever  description  of  plants  obtainable,  by  steeping  the 
plant  from  which  the  fibre  is  derived,  while  in  the  state  of  straw,  stem,  lea^  or  fibre, 
first  in  a  solution  of  caustic  soda,  or  other  solution  of  like  properties,  and  then  in  a 
bath  of  dilute  sulphuric  or  other  acid,  as  before  exemplified  and  described. 

"Fourth, — I  claim  the  preparing  of  the  said  vegetable  fibre  for  spinning  in  cotton 
and  silk  machinery,  and  for  being  confined  with  cotton,  wool,  raw  silk,  or  other 
materials  of  short  staple,  by  firstly  steeping  the  same  in  a  solution  of  caustic  soda,  or 
other  solution  of  like  properties.  Secondly,  steeping  them  in  a  bath  of  dilute  sulphuric 
or  other  suitable  acid,  or  exposing  them  to  the  fumes  of  sulphur.  Thirdly,  saturating 
them  with  a  solution  of  bicarbonate  of  soda  or  any  other  like  agent,  and  then  de- 
composing such  salt,  however  such  decomposition  may  be  effected ;  and,  fourthly, 
cutting  them  up  into  short  lengths,  all  as  before  exemplified  and  described. 

"Fifth, — I  claim  the  employment  generally  in  the  preparation  of  flax,  hemp,  and 
other  sorts  of  vegetable  fibre,  of  the  mode  of  splitting  by  gaseous  expansion,  as  before 
described,  whether  the  fibre  is  long  or  short,  and  whatever  may  be  the  purpose  to 
which  the  same  is  to  be  applied. 

"Sixth, — I  claim  the  manufacture  of  yams  and  felts  from  a  combination  of  flax,  or 
like  vegetable  fibre  (china  grass  excepted),  prepared  and  mixed,  as  aforesaid,  with 
cotton  wool,  '  tschudy,'  silk  waste,  fur,  and  hair,  all  or  any  of  them  as  before  exempli- 
fied and  described." 

Another  process  for  treating  flax  is  shortly  to  be  introduced,  which  is  said  to  surpass 
that  of  M.  Claussen  in  its  results.  This  is  the  patented  invention  of  Mr.  Bower,  of 
Hunslet,  but  as  his  specification  is  not  yet  enrolled,  we  withhold,  for  obvious  reasons, 
the  details  of  his  plan,  and  forbear  to  express  any  opinion  of  its  practicability.  The  treat- 
ment of  flax,  in  its  early  stages,  is  a  matter  of  vast  importance  to  this  country ;  and  per- 
haps there  is  no  one  problem  throughout  our  manufactures  whose  solution  would  better 
repay  the  successful  experimenter,  than  how  the  facilities  for  working  cotton  and  wool 
are  to  be  communicated  to  flax. — Newton's  Journaly  October,  1851. 

Mr.  D.  F.  Bower  obtained  in  March,  1851,  a  patent  for  retting  and  preparing  flax, 
in  which  he  submits  the  flax,  after  steeping  it  for  six  days  in  cold  or  hot  water,  to  the 
pressure  of  rollers  once  and  again,  with  steeping,  in  order  to  expel  the  glutinous  matter, 
and  then  dries  it  Line  is  treated  with  dUute  water  of  ammonia,  or  alkaline  saline 
solution.  He  also  avails  himself  of  the  air-pump,  along  with  the  above  solvents^  for 
the  extraction  of  the  gluten  by  means  of  hot  water. 


With  the  object  of  giving  the  flax  grower  the  means  of  rendering  his  produce  fit 
for  the  market,  Mr.  M'Pherson,  of  Edinburgh,  has  constructed  a  portable  breaking  and 
scutching  machine,  suitable  for  a  farmstead.     It  consists  of  two  rectangular  wooden 
cases,  of  unequal  size,  connected  together  side  by  side,  the  smaller   containing  the 
breaking  apparatus,  and  the  larger  the  parts  for  scutching  the  flax.     The  small  case  i» 
provided  with  a  horizontal  table,  having  a  fluted  surface,  whereon  the  flax  is  laid;  and 
over  the  table  a  fluted  roller  is  caused  to  travel,  for  the  purpose  of  cracking  the  boon, 
or  woody  portion  of  the  flax  plant     The  axes  or  pivots  of  the  roller  move  in  horizontal 
guides,  which  can  be  lifted  by  depressing  a  treadle,  for  the  purpose  of  raising  the  roller, 
and  the  traverse  of  the  roller  is  effected  by  its  connection,  through  a  rod,  with  a  crank 
on  the  end  of  a  short  horizontal  shaft,  which  is  caused  to  revolve  by  horse  or  other 
power.     The  shaft  also  carries  a  spur  wheel,  gearing  into  a  pinion  upon  another  hori- 
zontal shaft,  that  extends  through  the  large  case.     IJpon  this  second  shaft  (within  the 
large  case)  are  fixed  two  discs  or  bosses,  to  which  four  pairs  of  long  radial  arms  are 
bolted;  and  to  the  outer  ends  of  each  pair  of  arms  is  fastened  a  wooden  beater,  of  a 
L  shape,  in  the  transverse  section.     At  the  top  of  the  large  case  two  channels  are 
made  to  receive  the  clamps,  in  which  the  stricks  of  flax  to  be  scutched  are  held  to 
receive  the  blows  of  the  beaters.     The  flax  is  first  laid  upon  the  fluted  table,  and  sub- 
mitted to  the  action  of  the  traversing  roller  until  the  boon  is  broken  up  and  suflicientlj 
loosened  from  the  fibre ;  it  is  then  removed,  and  secured  in  given  quantities  between 
a  pair  of  clamps,  in  such  a  manner  that  one-half  the  length  of  the  plant  is  pendent 
therefrom.     Clamps  or  holders  thus  filled  are  successively  passed  into  one  of  the 
channels  in  the  large  case,  and  as  they  are  pushed  forwards  towards  the  other  end  of 
the  machine,  the  stricks  of  flax  are  brought  under  the  action  of  the  rotating  beater, 
whereby  the  pendent  portion  of  the  flax  is  cleared  of  its  boon.     When  this  is  effected, 
the  holders  are  removed  from  the  channels  and  opened,  to  turn  the  end  of  the  flax; 
the  clamps  are  then  again  tightened  and  introduced  into  the  other  channel,  to  bring 
the  other  end,  in  like  manner,  under  the  action  of  the  beaters.     When  the  apparatus 
is  in  full  operation,  botli  channels  will  be  full  of  holders ;  and  the  introduction  of  a 
fresh  holder  at  one  end  is  the  means  whereby  a  holder,  containing  a  strick  of  scutched 
flax,  is  discharged  at  the  opposite  end.     This  machine,  according  to  the  statement  of 
the  inventor,  is  calculated,  by  the  application  of  from  three  to  four  horse  power,  t« 
clean  half  an  acre  of  flax  per  diem. 

Mr.  Pluinmer,  of  Newcastle-ui^on-Tyne,  has  exhibited  machinery,  and  of  a  new  con 
struction,  for  breaking  and  scutching  flax,  and  for  heckling  what  is  technically  known 
as  "  cut  line."  The  breaker  consists  of  a  cast-iron  framing,  carrying  five  fluted  rollep 
of  similar  diameters,  and  connected  together  by  geering  wheels,  so  that  the  driving 
of  the  axle  of  one  by  a  band  and  pulley  will  cause  the  other  to  rotate  at  the  same 
speed.  This  machine  is  provided  with  two  platforms,  the  one  for  conducting  the 
flax  to  the  rollers,  and  the  other  for  guiding  it  out  of  the  machine.  Tlie  rollers  are  so 
arranged  as  to  bite  the  flax  three  times  during  its  passage  through  the  machine ;  and 
the  top  rollers  are  weighted,  for  insuring  a  proper  amount  of  pressure  bciug  put  upoc 
the  flax. 

The  scutching  machine  consists  of  a  rotary  vertical  disc  inclosed  in  a  casing,  and 
carried  by  an  axle  working  in  suitable  bearing,  supported  by  the  frame  of  the  machine. 
On  each  side  of  the  disc  radial  beaters,  or  wooden  knives,  having  a  bevelled  edge  od 
their  inner  face,  are  fixed ;  but  on  one  side  of  the  disc  the  beaters  are  alternated  by 
radial  brushes,  the  object  being  to  submit  the  flax,  first  to  the  action  of  the  beaten 
only,  and  then  to  effect  the  more  thorough  separation  of  the  boon  from  the  fibre  by 
the  combined  action  of  brushes  and  a  second  set  of  beaters.  An  opening  is  formed  in 
the  front  of  the  case  through  which  the  flax  is  introduced  by  hand  to  the  action  oi 
the  beaters.  When  one  end  is  cleaned,  the  operator  turns  ends,  and  again  submits 
the  flax  to  the  scutching  operation.  By  the  use  of  a  solid  disc  in  place  of  radial  arms 
(as  hitherto  used)  for  carrying  the  beaters,  it  would  seem  that  greater  speed  than 
hitherto  applied  may  be  used  without  the  risk  of  breaking  the  staple,  as  tlie  objection 
presented  by  the  arms,  of  causing  the  flax  to  lash  round  them,  and  thereby  get  broken 
when  working  at  great  speed,  is  necessarily  avoided. 

The  next  stage  of  treating  flax  is  to  subject  it  to  the  action  of  the  heckling  machine^ 
whereby  the  flax  is  combed  out,  and  its  fibres  are  subdivided  to  the  extent  required  j 
the  short  entangled  fibres  being  at  the  same  time  removed  from  the  more  valuable 
staple.  The  extent  to  which  the  separation  is  carried  is  to  produce  a  yield  of  onlj 
from  50  to  80  lbs.  of  "  dressed  line,"  as  the  more  valuable  staple  is  termed,  out  of 
112  lbs,  of  scutched  flax,  the  remainder  constituting  the  raw  material  known  as  tow, 
which  in  general  goes  to  form  an  inferior  description  of  yarn.  If  the  flax  is  intended 
to  be  spun  to  a  fine  quality  of  yarn,  or  a  *'  high  number,"  it  is  cut  into  two,  three,  or 
more  lengths,  before  being  submitted  to  the  heckling  machine ;  the  coarser  parts  of  the 
staple,  that  is,  the  extremities,  being  separated  from  the  others,  to  form  a  mediuna 

Vol.  L  5  H 


ft- 


786 


FLAX. 


FLAX. 


787 


quantitv  of  yarn,  while  the  middle  portions  are  selected  for  conyei^ion  into  fine  ^arn. 
The  action  of  th^  heckling  machine,  as  far  as  the  operation  itself  is  concerned,  is  th« 
same  whether  the  long  or  short  staple  be  heckled ;  but,  to  eftect  the  operation  econo- 
micallv  that  is,  without  making  an  undue  amount  of  tow,  different  constructions  of 
machines  are  preferred  for  dressing  the  long  and  the  cut  line.     For  heckling  the  latter 
kind  of  staple,  Mr.  Plummer  exhibited  a  machine  embracing  some  novel  points  deserving 
of  notice.     It  is  of  that  class  of  machines  which  have  two  heckle  cylinders  revolving  in 
opposite  directions,  and  dressing  both  sides  of  the  strick  of  flax  simultaneously,  but 
which  have  hitherto  met  with  very  partial  success,  as  the  cost  with  which  they  work 
scarcely  compensates  for  the  waste  of  material  they  occasion,  from  the  fact  of  two  sets 
of  heckles  entering  the  strick  simultaneously,  and  tearing  through  it  without  the  power 
of  yielding  to  the  entangled  or  interlocked  tibres.     Now,  in  order  to  remedy  this  evil  in 
part  one  of  tlie  cylinders  is  mounted  on  sliding  bearings ;  so  that  each  strick  of  flax  on 
being  first  presented  to  the  heckle-pins,  will  be  partially  combed  by  the  cylinder,  which 
ismounted  in  stationary  bearings,  before  the  traversing  cylinder  approaches  to  act  upon 
the  strick.     These  cylinders  are  furnished  with  three  grades  ot  heckle-pins,  and  the 
rows  on  the  first,  or  coarsest  set,  are  alternated  by  rows  of  brushes.    ITie  motion  for 
traversing  the  holders,  containing  the  stricksof  flax  through  the  machine  is  somewhat 
novel  and  ingenious.     Mounted  near  one  end  of  the  holder  trough  (which  receives  it* 
up-and-down  motion  for  bringing  the  length  of  stricks  gradually  under  the  operation 
ot'the  heckle  cylinders  by  the  ordinary  arrangements  of  mechanism)  is  a  short  axle, 
which  carries  three  pinion^  two  of  which  take  into  vertical  racks,  attached  to  the  end 
framing ;  and  the  central  pinion  geers  into  a  rack  formed  on  a  horizontal  reciprocating 
bar,  carried  by  the  trough,  and  provided  with  loose  pendent  fingers.     As  the  trough 
asc^nd^  to  take  in  a  fresh  holder,  the  pinions,  working  on  the  fixed  vei-tical  racks,  are 
rotated,  and  thus  the  central  pinion  is  made  to  draw  forward  its  rack  with  the  sliding  rod 
by  whidi  means  the  pendent  fingers  are  brought  in  contact  with  the  ho  dei-s  and  caused 
to  propel  them  forward.     On  the  descent  of  the  trough,  the  reverse  action  takes  place , 
and  the  reciprocating  bar  being  slidden  back,  the  fingers,  which  are  hinged  so  as  to 
pass  back  over  the  holders,  are  brought  to  a  proper  position  for  propelling  then,  for- 
ward on  the  next  ascent  of  the  trough  ;  this  reciprocating  bar  is  common  to  ^^"7 J^^c^- 
ling  machines,  but  the  mode  of  actuating  it  appears  to  us  to  be  ^^^VZ^ni  tZ  ^ 
On  the  ascent  of  the  trough  to  receive  another  holder,  and  discharge  at  the  same  time  a 
holder  of  heckled  flax,  the  traversing  cylinder  is  caused  to  retire  by  ^,^^^«^P^  "^^^^;^^";;^ 
contrivance,  and  thul  allow  of  the  strick  of  flax  just  received  into  the  machine  as  well 
^  thoL  which,  in  consequence,  have  been  shifted  forward  to  a  finer  set  of  heckle  pins, 
t^  rS^^ughtTfirst  under  the  action  of  the  heckle  cyiinder,  which  works  in  stationa^ 
bearing  and  then  under  the  action  of  the  pins  of  the  traversing  cylinder,  as  before 
SSed!  the  ascent  of  the  trough  being  made  the  means  of  driving  fcack  the  cylinder 
and  its  decent  allowing  of  its  moving  forward  to  operate  upon  the  Aax.     The  heckle 
cylinders  are  cleaned  af  usual  by  rotating  brushes ;  and  an  endless  band  of  lattice-work 
L  prov^ed  for  gathering  the  tow  into  a  proper  receptacle.     ^^  he  her  or  no  this  ma- 
IFne  I   destined  to  takf  a  permanent  place  in  our  flax  manufactories,  a  mere  inspec- 
Uon  of  it  in  ks  quiescent  state  is  not  sufficient  to  enable  us  to  judge :  as  regards  com- 
D^tnesi    t  has  greatly  the  advantage  of  the  double  cylinder  machines  of  Messrs. 
?,rwsonVson?o!  Lee^s,  whose  cont^ribution  we  shall  next  notice;  but  we  can  give 
no  opinion  of  their  relative  merits  in  other  respects.  ,•  ^^^^  ti,« 

This  firm  has  made  by  far  the  largest  display  of  flax  machmery;  and,  indeed  the 
credi  is  rainW  due  to  them  that  the  Great  Exhfbition  has  represented  this  important 
branch  of  our  manufactures.  Their  contribution  may  be  briefly  stated  to  have  included 
a  complete  set  of  machinery  for  heckling,  spreading,  drawing,  and  '•"^»«|  l^"/J°f^J^' 
flax  •  also  for  carding,  drawing,  and  roving  tow  ;  for  spinning  coarse  and  fine  flax  yarn , 
and'hkeW  for  manufacturing  thread."  For  treating  «i>«rt  flax,  a  pair  of  cylinder 
heck  ng  machines  were  exhibited.  The  cylinders,  instead  of  being  set  abreast  of  each 
other  and  acting  simultaneously  on  the  flax,  are  mounted  in  a  line,  and  revolve  m 
opposite  directions,  so  that  the  flL  is  dressed,  first  on  one  side  by  one  cylinder,  and 
Xn  on  the  opposite  side  by  the  other  cylinder.  The  objection  o  this  arrangement  ib. 
as  before  indicated,  the  want  of  compactness;  as  machines  working  on  th)S  principle 
Tre  1  eq  dred  to  be  double  the  length  ot"  those  which  turn  the  strick  and  heckle  both  side« 
on  the^sar^e  heckle-pins,  or  heckle  it  simultaneously  on  both  sides.  To  remedy  this  ol^ 
jection,  however,  MeLs^.awson  apply  two  troughs  to  the  niachme,  and  arc  thj  enabled 
to  submit  two  rows  of  stricks  to  the  action  of  the  same  rotatmg  heckle  cylinder.  Tlie 
mode  oTtraTersTng  the  flax  holders  through  the  machine  is  analogous  to  that  described 
S  reference  to  Mr.  Plummer's  machine,  and  therefore  need  not  to  be  repeated.  The 
"ylSs  are ?^^^^^^  with  two  gradesof  heckle-pins ;  and  ^^^ll^-^^^^,^^^^^ 
aid  falling  plates  (which  take  their  motion  from  excentrics)  are  fitted  for  the  purpose 


of  determining  the  depth  that  the  heckle-pins  shall  enter  the  stricks.     Between  the 
rows  of  the  finer  grade  of  heckles,  small  flat  brushes  being  set  in  one  edge  of  the  rising 
and  falling  plates  form  a  sort  of  bed  for  the  flax  to  lie  on  while  under  the  action  of  the 
heckle&     The  stricks,  in  passing  over  one  cylinder,  are  heckled  on  one  side  ;  they  are 
then  brought  under  the  action  of  the  second  cylinder,  which,  revolving  in  an  opposite 
direction,  will  finish  the  other  side  of  the  strick.     The  machine  exhibited  by  this  firm 
for  operating  upon  long  fibres  is  provided  with  two  endless  bands  of  heckles,  set  side  by 
Bide,  and  arranged  so  as  to  present  an  inclined  surface  to  the  flax.     These  bands  are  set 
at  opposite  inclines,  and  revolve  in  different  directions,  for  the  purpose  of  operating 
upon  different  sides  of  the  stricks  of  flax.     Tliese  are  the  only  arrangements  of  heckling 
and  machinery  which  the  Exhibition  contained.     It  must,  therefore,  be  considered  as 
very  deficient  in  this  respect,  as  the  rival  inventions  of  Messrs.  Marsden,  of  Manchester, 
and  Messrs.  Combe,  of  Belfast,  for  turning  the  stricks  of  flax,  and  causing  them  to  be 
operated  upon  on  both  sides  by  the  same  cj^linder  (which  have  recently  been  the  cause 
of  so  much  litigation)  are  unrepresented.     So  also  is  a  still  more  recent  improvement 
of  Messi-s.  Combe,  for  heckling  both  sides  of  the  strick  without  turning,  by  the  use  of 
but  one  cylinder.    In  this  machine  (which  we  have  had  recently  an  opportunity  of  seeing 
in  action  at  Belfast)  the  means  of  operating  on  both  sides  of  the  strick  is  obtained  by 
merely  reversing  the  direction  of  rotation  of  the  cylinder,  while  the  trough  is  ascending 
to  take  in  a  fresh  holder.     Another  arrangement  of  a  promising  character,  for  passing 
once  through  the  machine,  has  recently  been  devised  by  Messrs.  Harding,  Cocker,  & 
Co.,   of  Lille;  but  as  this  machine  was  not  included  m  their  contribution  to    the 
Exhibition,  we  conclude  that  it  is  not  yet  brought  into  the  market.     The  flax,  after 
leaving  the  heckling  machine,  is  slightly  combed  by  hand,  and  sorted  into  parcels, 
according  to  the  quality  of  the  staple  ;  it  is  then  packed  away  in  a  cool,  dry,  dark  room, 
and  by  lying  there  for  a  i^w  months  its  quality  is  said  to  improve.     When  the  flax  is 
taken  from  the  "  dressed  line  store,"  it  is  subjected  to  the  action  of  the  following 
machines,  for  the  purpose  of  converting  it  into  yarn,  viz. ;  1.  The  first  drawing  frame, 
or  spreader,  the  use  of  which  is  to  convert  the  flax,  as  delivered  from  the  heckling 
machine,  into  a  continuous  sliver  or  band  of  filaments;  2.  The  second  drawing  frame, 
by  which  the  sliver  is  attenuated  ;  3.  The  third  drawing  frame,  whereby  several  slivers 
from  the  second  drawing  frame  are  united  together  ^nd  redrawn,  to  obtain  a  finer  sliver, 
with  greater  regularity  of  fibre;  4.  The  roving  frame,  which  further  elongates  the 
sliver,  and  converts  it  into  a  spongy  cord  or  roving;  5.  The  throstle  frame,  which 
extends  the  spongy  or  loose  roving,  and  spins  it  into  yarn.     The  flax  drawing  frame  is 
very  different  in  construction  to  that  formerly  described  as  employed  for  drawing  cotton, 
although  the  action  is  precisely  analogous.     Its  constructions  and  mode  of  operation 
may  be  thus  briefly  described  :  at  the  back  of  the  machine  is  an  endless  travelling  feed- 
cloth,  on  which  the  stricks  of  flax  are  laid,  so  as  to  overlap  each  other,  and  which  carries 
the  flax  to  what  are  termed  the  back  holding  rollers.     In  front  of  these  rollei-s,  and 
arranged  parallel  thereto,  is  a  series  of  "  gills  "  or  straight  bars  furnished  with  heckle- 
pins,  whose  office  is  to  receive  the  flax  as  it  is  delivered  from  between  the  holding- 
rollers,  and  carry  it  forward  to  the  drawing-rollers.     These  gills  are  supported  and 
traversed  by  their  extremities,  taken  into  the  threads  of  two  screw  sliafts,  set  at  right 
angles  to  the  holding  rollers,  which  shafts,  as  they  rotate,  carry  the  gills  forward. 
When  they  have  arrived  at  the  end  of  the  shaft  they  severally  fall,  and  are  received  bv 
a  pair  of  screw  shafts  below,  having  a  quicker  thread,  which  carry  them  back  to  the 
holding  rollers,  and  a  sweep,  on  the  end  of  these  shafts,  lifts  the  gills  up  again  into  geer 
with  the  upper  screw  shafts.     Thus  an  endless  chain,  as  it  were,  of  gills  is  provided, 
which,  having  a  somewhat  greater  speed  than  the  holding  rollers,  combs  the  flax  straight 
and  delivers  it  with  perfectly  parallel  fibres  to  the  drawing  rollers.     By  these  the  sliver 
is  drawn  to  the  requisite  fineness,  and  then,  passing  between  a  pair  of  calendering 
rollers,  it  is  delivered  to  a  can.     The  cans  of  sliver,  thus  produced,  are  now  set  up 
behind  the  second  drawing  frame,  to  undergo  the  second  operation.     This  frame,  and 
also  the  third,  are  similar  in  construction  to  the  first ;  the  only  difference  being,'  that 
they  are  fed  from  cans  instead  of  by  a  cloth  ;  and  as  the  progress  of  drawing  out  the  sliver 
advances,  the  size  of  the  working  parts  are  required  to  be  less,  and  the  fineness  of  the 
gills  to  be  increased.     The  operation  of  drawing  is  the  same  in  all  cases  ;  but  in  the 
second  and  third  frames,  the  sliver  is  doubled,  to  give  it  an  evenness,  or  structural 
equality,  as  it  is  elongated. 

Messrs.  Lawson  have  exhibited  screw  gill  spreaders  (as  the  first  drawing  fi-ame  is 
termed)  for  both  long  and  cut  flax;  also  gill  frames  for  completing  the  drawing  of  the 
long  and  short  fibre,  but  further  than  being  well  made  machines,  they  present  no  points 
for  comment. 

Messrs.  Higgins  <fe  Sons  have  also  exhibited  a  screw  gill  spreader  and  a  second 
drawing  frame  for  long  lines.  In  the  former  of  these  machines  the  front  top  rollers  are 
weighted  by  an  arrangement  of  compound  levers,  which  is  said  to  have  the  advantage 

6  H  2 


it  i 


788 


FLAX. 


FLAX. 


789 


i 


ill 


1 


of  convenicfice  over  the  ordinary  plan  ;  and  in  the  latter,  the  roller  and  gilla  are  driven 
at  the  middle  instead  of  the  side  of  the  machine;  thus  relieving  the  rollers  of  a  great 
portion  of  the  strain  to  which  they  are  ordinarily  exposed,  and  permitting  of  the  use 
of  smaller  rollers,  which,  for  some  descriptions  of  work,  is  considered  of  importance. 

The  sliver,  as  it  is  delivered  into  cans  from  the  third  drawing  frame,  is  taken  to  the 
roving  frame  to  be  still  further  reduced  and  wrought  into  a  loose  thread  ;  but  as  this 
operation  is  precisely  similar,  whether  for  long  line,  cut  line,  or  tow,  it  may  be  well  to 
explain  briefly  the  means  of  bringing  tow  to  a  proper  state  for  undergoing  the  first 
spinning  process  before  speaking  of  the  roving  frame.  The  tow,  which  we  have  said  is 
the  short  and  irregular  fibres  combed  out  of  the  strick  of  flax  by  the  heckling  machine, 
is  subjected  to  the  action  of  a  carding  engine,  somewhat  similar  in  construction  to  that 
used  for  carding  cotton.  It  consists  principally  of  a  large  central  cylinder,  covered  with 
■wires,  cards,  and  surrounded  by  card  rollers  termed  "workers"  and  "strippers,"  revol- 
ving in  contact  therewith.  The  tow  is  carried  into  the  machine  by  an  endless  travelling 
cloth,  which  delivers  it  to  a  pair  of  feed  rollers,  situate  below  the  main  cylinder,  where- 
by it  is  transferred  to  the  large  cylinder.  By  this  it  is  brought  under  the  action  of 
the  workers,  when  combed  or  carded ;  and  it  is  then  stripped  or  "  doffed  "  from  the 
cylinder  by  card  rollers,  which  in  their  return  are  relieved  of  the  staple  by  doff'er  combs ; 
these  take  it  off  in  the  form  of  a  sliver,  and  it  is  eventually  delivered  from  the  machine 
by  delivering  rollers  into  cans.  In  order  to  prevent  the  liability  of  the  sliver  breaking 
by  being  pressed  down  into  the  cans,  and  also  to  avoid  the  necessity  of  using  a  separate 
machine  for  performing  the  first  drawing  operation,  it  has  lately  been  the  practice  to 
apply  one  or  more  gill-drawing  heads  to  the  carding  engine,  according  to  the  number 
of  strippers  employed  and  slivers  produced,  and  carry  on  the  carding  and  the  fii-st 
drawing  processes  simultaneously.  This  arrangement,  patented  by  Messrs.  Fairbairn 
&  Co.,  was  applied  to  Messrs.  Lawson  &  Son's  carding  engine.  It  is  provided  with 
three  strippers,  which  are  capable  (by  being  set  at  different  distancesfrom  the  main  cy- 
linder) of  taking  off  different  lengths  of  staple  from  the  card  surface,  and  thereby 
sorting  out  or  dividing  the  qualities  of  the  tow.  In  this  machine,  however,  there  is 
but  one  gill-head ;  all  the  slivers,  therefore,  are  united  in  the  first  drawing  process,  and 
form  together  a  continuous  sliver;  the  completion  of  the  operatic  i  of  drawing  tow  is 
precisely  similar  to  that  already  described  with  reference  to  long  and  cut  line. 

To  obtain  a  flax  roving,  it  is  usual,  after  drawing  the  sliver  to  the  required  amount, 
to  put  in  its  slight  twist.  Messrs.  Higgins  exhibited  a  roving  frame  with  six  heads  and 
sixty  spindles,  for  producing  roving  of  this  kind.  This  roving  frame  is,  in  fact,  to  de- 
scribe it  shortly,  a  drawing  frame,  with  the  addition  of  spindles ;  the  gills  and  rollers 
being  driven  according  to  their  improved  plan,  before  noticed. 

The  roving  frame  for  cut  flax  exhibited  by  Messrs.  Lawson,  is  intended  to  produce  a 
roving  without  twist,  v/Lich,  for  obtaining  fine  qualities  of  yarn,  is  very  desirable  ;  the 
gummy  matter  in  the  flax  is  here  taken  advantage  of  to  give  the  roving  the  necessary 
cohesive  property.  A  correct  notion  of  the  construction  of  this  roving  frame  may  be 
best  conveyed  by  tracing  the  progress  of  the  sliver  through  the  machine.  The  sliver 
passes  from  the  can  over  a  pulley  through  fixed  guides  over  travelling  gills,  between  a 
pair  of  drawing  rollers,  then  into  a  trough  containing  hot  water  (for  the  purpose  of  dis- 
solving the  gummy  matter  in  the  flax),  then  over  a  heated  cylinder  which  dries  thu 
8taple,°and  finally  it  is  wound  on  to  a  bobbin,  which  rests  upon  and  turns  in  contact 
with  a  horizontal  fluted  roller.  Rovings  thus  produced  are  capable,  it  is  said,  of  being 
drawn  to  almost  any  degree  of  fineness,  with  little  reference  to  the  inaterial ;  because 
one  fibre  can  be  glued  to  another ;  at  any  portion  of  its  length  a  roving  can  be  made. 
Messrs.  Lawson  also  contributed  machinery  for  wet  and  dry  spinning,  viz.,  a  dry  tow 
spinning  frame,  with  100  spindles ;  a  fine  spinning  frame  for  spinning  the  roving  through 
cold  water;  a  double  water  frame,  with  136  spindles;  and  a  double  twisting  frame  with 
96  spindles.  The  only  noticeable  novelty  in  these  machines  (the  construction  of  which 
will  be  understood  from  the  description  already  given  of  cotton  spinning  machinery)  is 
a  new  tape  motion  for  driving  the  spindles.  A  spinning  frame,  by  Messrs.  Iliggius, 
containing  144  spindles  was  also  exhibited ;  but  further  than  being  a  specimen  of  good 
design  and  workmanship,  it  calls  for  no  special  remark. 

netting  of  Flax. — Mr.  Watt's  system  of  flax  retting  may  be  briefly  described  as  fol- 
lows:  ^The  flax  straw  is  delivered  at  the  works  by  the  grower,  in  a  dry  state,  with  the 

seed  on.  The  seed  is  separated  by  metal  rollers,  and  afterwards  cleaned  by  fanners. 
The  straw  is  then  placed  in  close  chambers,  with  the  exception  of  two  doors,  which 
serve  the  purpose  of  putting  in  and  discharging  the  straw.  The  top,  which  is  of  cast 
iron,  serves  the  double  purpose  of  a  top  and  condenser.  The  straw  is  then  laid  on  a 
perforated  false  bottom  of  iron,  and  the  doors  being  closed,  and  made  tight  by  means 
of  screws,  steam  is  driven  in  by  a  pipe  round  the  chambers,  and  between  the  bottoms ; 
and,  penetrating  the  mass,  at  firet  removes  certain  volatile  oils  contained  in  the  plant, 
and'  afterwards  is  condensed  on  the  bottom  of  the  iron  tank,  and  descends  as  a  con- 
tinuous shower  of  condensed  water,  saturating  the  straw.  This  water  is  a  decoction 
of  extractive  matter,  to  which  attach  the  fibrous  and  more  porous  portions.  This  liquor 
is  run  of  from  time  to  time,  the  more  concentrated  portions  being  used  for  feeding. 


The  process  is  shortened  by  using  a  pump,  or  such  an  arrangement  as  rapidly  washes 
the  mass,  with  the  water  allowed  to  accumulate.  In  about  eight  or  twelve  hours, 
varj'ing  with  the  nature  of  the  straw,  it  is  removed  from  the  chambers,  and,  having 
been  robbed  of  its  extractive  matter,  it  is  then  passed  through  the  rollers  for  the  pur- 
pose of  removing  the  epidermis,  or  skin  of  the  plant,  and  of  discharging  the  greater 
part  of  the  water  contained  in  the  saturated  straw,  and  while  in  the  wet  and  swollen 
state,  splitting  it  up  longitudinally.  The  straw  then  (being  free  of  all  products  of 
decomposition)  is  easily  dried,  and  in  a  few  hours  ready  for  scutching. 

In  tne  experimental  trial,  personally  superintended,  throughout  all  its  details,  by 
the  Committee,  a  quantity  of  flax  straw,  of  ordinary  quality,  was  taken  from  the  bulk 
of  the  stock  at  the  works,  weighing  13|  cwts.  with  the  seed  on.  After  the  removal  of 
the  seed,  which,  on  being  cleaned  thoroughly  from  the  chaff,  measured  3f  Imperial 
bush.,  the  straw  was  reduced  in  weight  to  10  cwt  1  qr.  21  lbs.  It  was  then  placed  in 
the  vat,  where  it  was  subjected  to  the  steaming  process  for  about  eleven  hours.  After 
steeping,  wet-rolling,  and  drying,  it  weighed  7  cwt  0  qrs.  11  lbs. ;  and,  on  being  scutched, 
the  yield  was  187  lbs.  of  flax;  and  of  scutching  tow,  12  lbs.  6^  ozs  fine,  and  35  lbs.  3 
ozs.  coarse.  The  yield  of  fibre,  in  the  state  of  good  flax,  was,  therefore,  at  the  rate  of 
13|  lbs.  from  the  cwt.  of  straw  with  seed  on ;  18  lbs.  from  the  cwt  of  straw  without 
seed ;  26^^  lbs.  from  the  cwt.  of  steeped  and  dried  straw. 

The  time  occupied  in  actual  labour,  in  the  processes,  from  the  seeding  of  the  flax  to 
the  commencement  of  the  scutching,  was  13^^  hours,  to  which,  if  11  hours  be  added  for 
the  time  the  flax  was  in  tlie  vat,  24  hours  would  be  the  time  required  up  to  this  point 
The  scutching,  by  four  stands,  occupied  six  hours  sixteen  minutes.  But^  in  this  state- 
ment, the  time  required  for  drying  is  not  included,  as,  owing  to  some  derangement  in 
the  apparatus,  no  certain  estimate  could  be  made  of  the  actual  time  required  in  that 
process.  It  would  appear,  however,  that  about  thirty-six  hours  would  include  the 
time  necessarj^  in  a  well-organized  festablishment,  to  convert  flax  straw  into  fibre  for 
the  spinner. 

The  cost  of  all  these  operations,  in  this  experiment,  leaving  out  the  drying,  for  the 
reasons  noted,  appeared  to  be  under  10/.  per  ton  of  clean  fibre,  for  labour,  exclusive  of 
general  expenses. 

A  portion  of  the  fibre  was  sent  to  two  spinning-mills  to  be  hackled,  and  to  have  a 
value  put  upon  it  The  valuation  of  the  samples  varied  from  66/.  to  70/.  per  ton,  ac- 
cording to  the  quality  of  the  stricks  of  fibre  sent,  and  the  j'ield  on  the  hackle  was  con- 
sidered quite  satisfactory. 

On  the  results  of  this  experiment,  which  was  necessarily  of  a  limited  nature,  the 
Committee  think  it  best  to  offer  no  general  remarks.  They  are  sufficiently  favourable 
to  speak  for  themselves.    It  remains  to  be  ascertained  whether  the  qualities  of  flax  fibre 

Erepared  by  this  method  are  such  as  to  suit  the  spinner  and  manufacturer.  They  have 
een  informed,  by  a  spinner  who  has  been  trying  some  flax  prepared  by  Mr.  Watt's 
system,  that  the  yarn  made  from  it  appears  equal  in  all  respects  to  what  is  ordinarily 
spun  from  good  Irish  flax,  of  the  finer  sorts.  They  believe  that  before  long,  informa 
tion  will  be  given  by  several  individuals  who  are  about  to  carry  out  more  extended 
trials  on  the  spinning  and  manufacturing  departments. 

The  Committee  conceive  that  the  most  prominent  and  novel  feature  of  this  plan 
consists  in  the  substitution  of  maceration,  or  softening,  for  fermentation.  In  the  steep 
ing  of  flax,  both  by  cold  and  hot  water,  the  fibre  is  freed  from  the  substance  termed 
gum,  by  the  decomposition  of  the  latter,  while  in  Watt's  sj'stem  the  maceration  of  the 
stems  loosens  the  cuticle  and  gum,  which  are  further  separated  mechanically  in  the 
crushing  o|)eration,  and,  after  the  drying  of  the  straw,  readily  part  with  the  wood, 
under  the  action  of  the  scutch-mill. 

Before  concluding  this  statement,  the  Committee  wish  to  call  attention  to  a  very 
curious  feature  in  Mr.  Watt's  invention.  The  water  from  the  vats,  in  place  of  being 
offensive  and  noxious,  as  is  the  case  with  ordinary  steep  water,  contains  a  certain 
amount  of  nutritive  matter.  This  arises  from  its  being  an  infusion  of  .the  flax  stems, 
in  place  of  holding  in  suspension  or  solution  the  products  of  the  decomposition  of  the 
gum,  and  other  substances  contained  in  the  stems.  The  inventor  is  now  emplojing 
this  water,  along  with  the  chaff  of  the  seed-bolls,  for  feeding  pigs.  It  is  of  much  in 
terest,  therefore,  to  note  in  how  far  this  may  be  found  practically  to  answer,  as,  be- 
tween the  seed,  the  chaff,  and  the  water,  by  far  the  greatest  portion  of  what  the  flax 
plant  abstracts  from  the  soil,  would  thus  be  returned  in  the  shape  of  manure.  How- 
ever this  may  turn  out^  the  avoidance  of  all  nuisance  in  smell,  and  of  the  poisonous 
liquid  which  causes  some  damage  among  fish  when  let  off  into  rivers,  is  a  matter  of 
some  consequence. 

Appended  to  this  report  is  a  note  of  the  time  occupied  in  the  different  processes 
during  the  experiment,  and  of  the  number  of  persons  employed  in  each. 

It  is  to  be  hoped  that  so  promising  a  plan  ma}-,  on  more  extended  experience,  be 
found  fully  to  warrant  the  high  anticipations  formed  from  what  is  already  known 
concerning  it  ^  (Signed  on  behalf  of  the  Committee), 

RicuABD  NiVEN,  Chairmar. 

Belfast  3d  Nov.,  1852. 


'li-' 


i\ 


190 


FliAX. 


APPENDIX. 

XT  *  f  fv,^  fir^..  oP*.iiDied  and  of  the  number  of  persons  employed  in  each  of  the 
pro'^ctef  witLS  bTtuTcommittee,  on  the  experital  trial  of  Mr.  Watt's  systea. 
of  preparing  flax  fibre:—  No.  of  persons  employed.       ^ 

Men.  Women  and  Boys. 


Time  occupied. 
Hours.  Minutes. 


Seeding, 

Placing  in  Vat,  .   -        -        "        " 

Cleaning  Seed,       -  .     - 

Taking  out  of  Vat,        -         -         - 

Wet-rolling  and  putting  m  Drying 

Room, 

Rolling  for  Scutching,   -      ,  - 
Stricking  for  do.,  .        .        - 


4 
8 
1 
2 

1 
0 
0 


8 
4 
0 
8 

16 
11 

1 


1 
0 
8 
0 

2 
1 
4 


15 

15 

0 

30 

20 

8 

47 


Total, 


11  49  13        15 

Q     f  T,-  .         .        4  0  6         16 

CultiZionohlax  in  Fl under s.-Theve  is  a  very  fine  long  variety  of  flax  ^vhich  is 
euSed  in  thVnetrhbourh^  of  Courtray,  in  Flanders;  it  requires  a  very  good  soil 
t^grof^^^^^^  is  so  long  and  Blender,  that,  if  it  were  not  suppor^M^^ 

WtTind  would  break  it  and  lay  it  flat,  in  which  case,  the  quality  of  the  flax  %yould  be 
m^ch^mp^^^^^^^^^  quantit/reduced.  To  prevent  this,  short  stakes  are  driven  into 

Z  ^r3  n  a  straight  line  at  8  or  10  feet  from  each  other,  and  long  slender  rod.  are 
t?ed?o  ?hem  witl  oi^^^^^  about  1  foot  or  18  inches  from  the  ground,  forming  a  sl.gU 

Lmng    olupp^rt  r  flax^  a  number  of  these  are  placed  i^  tlie  same  -n.ner  a^  a  shoH 
^;»fanPP  from  each  other  in  parallel  lines  all  over  the  field,  and  the  flax  is  tuus  pre 
vented  from  berng  beat  down.     A  better  method,  which  is  not  common  y  adopted,  is 
Thlt  stXKut  rows,  and  thin  -Pes  t^d  to  them,  instead  o  -d^;^^^^^ 
these  lengthwise  and  others  across  them  at  right  angles,  a  kind  ^ll^'S^""^^^^^^^ 

ovpr  the  whole  field  and  none  of  the  flax  can  possibly  be  laid  flat     15y  using  cneap 

%:ro:fcrm^7vS;ol  tJ  rofVllr  Wk  w^h  a  stronger  stem ;  if 
it  k^o?sownTerthick  it  will  throw  out  branches  at  top  and  produce  °^"«h  «««d  ^  »^ 
L  LreforeTrtCr  of  calculation  whether  it  will  be  most  profitable  to  have  finer  flax 

seed  sooner     When  linseed  is  the  principal  object,  this  variety  is  preferred  ;  but  the 

^li:t7v"Vi:^^tfla^^^  and  shoots  out  stems  to  a  con  si  d  era  Wo 

he^ht     It  came  originally  from  Siberia,  and  was  much  recommended  at  onetime,  but 
height      At  ^ame  or  gi        y  ^         ^^^  ^     ^^  ^^^^  ^^^^^  ^^^^^ 

by  WnT'i g^^^^^^^^^^^         be  prSbly  cultivated  for  the  seed;  and  if  the  flax  is 
infer^r  fA  ou^lfty,  it  might  still  be  of  some  value  for  coarse  maniifactures ;  it  re- 
QuirerhoweTer  to  be  renewed  every  three  or  four  years  and  sown  in  fresh  ground 
^^Ss^rblJt' adapted  to  the  gro  jth  of  fl^^^^^^  a  deep  nch  loam  in  ^^^^^^^^^^ 

much  ^--YJou^'d  botoS'nither  to^  too  mlt;  either  extreme  infallibly 

but  anv  other  so  l  may  be  so  tilled  and  prepared  as  to  produce  good  flax.     It  thnves 

wellTnye  rich  alluvial  land  of  Zealand  and  the  Polders,  but  it  is  also  raised  with  great 

recess   n  the   igl Lands  of  Flanders,  but  much  more  careful  tillage  and  n;anuringare 

remii red      The  land  on  which  flax  is  sown  must  be  very  free  from  weeds  the  weeding 

ofTws  crop  being  a  very  important  part  of  the  expense  of  cultivation.      These  circvun- 

Inces  sulge^  the  best^mode  of  preparing  the  land.     A  long  fallow,  such  as  is  sorne^ 

tWs^ivef  to  the  land  in  Essex,  including  two  winters  and  a  summer,  may  be  a  good 

l^naSn  on  the  heavier  loams^  which  should  be  trenched,  ploughed  and  worked  deep ; 

?h7manure  sLuld  be  dung  fully  rotten,  or  a  compost  of  earth  and  dung ;  »t  shoi^M  be 

nut  on  the  land  in  autumn,  and  well  incorporated  before  the  seed  is  sown      K  the  land 

P     ffioLntl  V  olean  a  crop  of  potatoes  well  manured  may  be  substituted  with  advantage 

fo't  faUo^  but  at  leTst  dLble  the  usual  quantity  o'f  dung  should  be  given  to  this 

tor  tl^e  callow     out  ^^^  ^^^  ^^^     j^.^^  ^^  ^^^j  i^^^/  . 

crop,  that  enough  ma^r^^^^^^^^  S  in  the  lighter  loams  there  is  some  doubt  of  its 

contains  a  g^^^  P^^^^^^Yj  I'^li  ^  should  not  be  used  immediately  before  the  flax  is 
advantage  for  flax.     At  all  even  ^^^  ^^^^^^^^^  ^^^  ^,^^  ^^^^      ^ 

sown,  but  for  ^^^^  Fe>  lousjop^  ^^  ^^^  ^^^      ^^^  ^^^^  ^^  peat-ashes, 

Se  madTn  ^hrburnrnl  oTweedsind  earth  in  a  smothered  fire  are  a  good  substitute, 
those  maae  D>  tne  """^""'s  .    .,     gweepines  of  the  streets  in  towns,  mixed  with  the 

But  the  most  efl^ective  manure  ^^^  ^^^^^^  ^^^  ^^^^^^^ 

t^l'Z^u^^ri^^^^^  -<i  -^-  night-soil  cannot  be  obtained  in 


FLAX. 


791 


eufficient  quantities,  rape-cakes,  from  which  the  oil  has  been  expressed,  dissolved  in 
cow's  urine,  form  the  best  manure.  In  many  parts  of  Flanders,  600  rape-cakes  are 
used  for  every  acre  of  flax,  besides  the  usual  quantity  of  Dutch  ashes  and  of  liquid 
manure,  which  is  the  drainings  of  dunghills,  and  the  urine  of  cattle  collected  in  a 
cistern,  and  allowed  to  become  putrid. 

In  eouthern  climates  flax  is  sown  before  winter,  because  too  great  heat  would 
destroy  it.  It  is  then  pulled  before  the  heat  of  summer.  In  northern  climates  the 
frost,  and  especially  the  alternations  of  frost  and  thaw,  in  the  early  part  of  spring, 
would  cause  the  flax  to  perish ;  it  is,  consequently,  sown  as  early  in  8i)riiig  as  may  be, 
so  as  to  avoid  the  efi'ect  of  hard  frost  This  is  in  March  or  April,  in  Great  Britain  and 
Ireland,  and  in  Holland  and  Flanders.  In  no  country  is  the  ground  better  prepared 
for  the  growth  of  flax  than  in  Flanders ;  and  it  may,  therefore,  be  interesting  to  follow 
the  whole  process  of  Flemish  cultivation  for  several  crops,  preparatory  to  that  of  flax, 
which  is  the  most  important  produce  in  that  country,  and  that  which,  when  well 
managed,  gives  the  greatest  profit  to  the  farmer.  The  best  flax  grows  near  Courtray. 
The  soil  is  a  good  deep  loam,  rather  light  than  heavy.  It  is  not  naturally  so  rich  as 
the  soil  of  the  Polders  in  Flanders  and  Zealand,  but  the  tillage  and  cultivation  are  far 
more  perfect,  and  the  produce,  if  not  more  abundant,  is  of  a  finer  quality.  Every 
preceding  crop  has  a  reference  to  the  flax,  and  is  so  cultivated  as  to  improve  the 
texture  of  the  soil,  which  is  abundantly  manured,  in  order  to  leave  a  considerable 
surplus  in  the  ground.  If  the  land  has  not  been  trenched  all  over  with  the  spade,  to 
the  depth  of  18  or  20  inches,  it  has  been  equally  well  stirred  by  the  narrow  open 
drains,  which  are  dug  out  12  or  16  inches  deep  every  year,  between  the  stitches,  in 
which  it  is  laid  by  the  plough.  These  drains  or  water  furrows  are  a  foot  wide,  and 
from  a  foot  to  18  inches  deep.  The  earth  taken  out  of  them  is  spread  evenly  over  the 
land  after  the  corn  is  sown.  When  the  ground  is  ploughed  again,  care  is  taken  that 
the  place  of  these  water-fuiTows  shall  be  shifted  a  foot  on  each  side.  Thus,  in  six 
years,  the  whole  soil  is  deepened  and  thoroughly  mixed  with  whatever  manure  has 
been  put  on.  This  produces  the  same  eff"ect  as  trenching,  and  even  more  perfectly. 
The  whole  of  the  land  in  which  the  best  flax  grows  has  been  so  treated  for  several 
generations,  and  may  be  looked  upon  as  a  species  of  compost  18  inches  deep. 
Potatoes  or  colza  are  usually  planted  with  a  double  portion  of  manure,  after  which 
wheat  is  sown,  slightly  manured ;  then  rye  with  turnips  sown  the  same  year,  after  tlte 
rye.  These  are  taken  up  in  September  or  October,  and  stored  for  winter  use.  Th<* 
land  has  been  well  weeded  while  the  turnips  were  growing,  and  all  the  manure  is  de- 
composed and  mixed  with  the  soil.  It  is  ploughed  in  stitches  before  winter,  some 
manure  having  being  previously  spread  over  it  if  necessary:  and  it  is  left  to  the 
mellowing  eft'ects  of  frost  and  snow.  As  soon  as  the  winter  is  over,  and  the  snow  is 
melted,  the  final  preparation  goes  on.  Deep  ploughing  and  harrowing  further  divide 
and  pulverize  it ;  the  surface  is  laid  as  level  and  as  smooth  as  possible ;  and  if  there  is  no 
fear  of  too  much  wet,  which  in  this  light  loam  soon  disappears,  the  whole  is  laid  flat 
and  level  as  a  bowling-green,  or  else  divided  into  beds,  with  water-furrows  between 
them-  On  this  the  liquid  manure  is  poured  out,  and  the  Dutch  ashes  spread,  if  any 
are  used,  or  the  rape-cakes,  as  mentioned  before.  The  harrows  arc  drawn  over  the 
land,  and  it  is  left  so  a  few  days,  that  the  manure  may  sink  in.  It  is  then  again 
harrowed,  and  the  linseed  is  sown  broadcast  by  hand,  very  thick,  and  even  about 
1^  ewt  to  the  acre.  A  bush  harrow  or  a  hurdle  is  drawn  over,  merely  to  cover  the 
seed,  which  would  not  vegetate  were  it  buried  half  an  inch  deep.  According  to  the 
state  of  the  land,  it  is  rolled  or  not>  or  the  seed  is  trodden  in  by  men,  as  is  done  with 
fine  seeds  in  gardens.  This  is  only  in  the  lightest  soils.  Most  commonly  the  traineau 
is  drawn  over  the  land.  This  is  a  wooden  frame  with  boards  nailed  closely  over  it, 
which  is  drawn  flat  over  the  ground,  to  level  and  gently  press  it  In  a  short  time  the 
plants  of  flax  come  up  thick  and  evenly,  and  with  them  also  some  weeds.  As  soon  an 
the  flax  is  a  few  inches  high,  the  weeds  are  carefully  taken  out  by  women  and  children, 
who  do  this  work  on  their  hands  and  knees,  both  to  see  the  weeds  better,  and  not  to 
hurt  the  flax  with  their  feet  They  tie  pieces  of  coai-se  flax  round  their  knees,  and 
creep  on  with  their  face  to  the  wind  if  possible.  This  is  done  that  the  tender  flax 
which  has  been  bent  down  by  creeping  over  it,  may  be  assisted  by  the  wind  in  rising. 
This  shows  what  minute  circumstances  are  attended  to  by  this  industrious  people.  The 
weeding  is  repeated  till  the  flax  is  too  high  to  allow  of  it 

The  seed  which  is  used  is  generally  obtained  from  Riga,  it  being  found  that  the  flax 
raised  from  home-grown  seed  is  inferior  after  the  first  year.  But  many  intelligent  men 
maintain  that  if  a  piece  of  ground  were  sown  thin  with  linseed,  so  that  the  flax  could 
rise  with  a  strong  stem  and  branch  out,  and  if  the  seed  were  allowed  to  ripen,  the 
Flemish  seed  would  be  as  good  as  that  from  Riga  ;  but  it  still  remains  to  be  proved 
whether  it  would  be  cheaper  to  raise  it  or  to  import  it 

When  the  flax  begins  to  get  yellow  at  the  bottom  of  the  stem,  it  is  time  to  pull  it,  if 
very  fine  flax  is  desired,  such  as  is  made  into  thread  for  lace  or  fine  cambric ;  but  then 
the  seed  will  be  of  little  or  no  value.  It  is  therefore  generally  left  standing  until  the 
capsules  which  contain  the  seed  are  fully  grown,  and  the  seed  formed.     Every  flax- 


i 


^ 


792 


FLAX. 


crower  rndges  for  himself  what  is  most  profitable  on  the  whole.  The  pull  ing  then  be^na, 
whkh  iTdone  carefully  by  small  handfuls  at  a  time.  These  are  aid  upon  he  ground  to 
In  two  and  tvvo  obliquely  across  each  other.  Fine  weather  is  essentjal  to  this  part 
of^the  operation.  Soon  after  this  they  are  collected  in  the  larger  bundles,  and  placed 
with  the  root  end  to  the  ground,  the  bundlesbeing  slightly  tied  near  the  seed  end  ;  the 
Ither  end  is  spread  out  that  the  air  may  not  have  access  and  the  ram  may  not  damage 
the  flax  When  sufficiently  dry  they  are  tied  more  firmly  in  the  middle,  and  stacked 
Sloncrnarrow  stocks  on  the  ^ouni  These  stacks  are  built  ns  wide  as  the  bundles 
are  long  aXabout  8  or  9  flet  high.  The  length  depends  on  the  frop:  ^hey  are 
Lldomfiade  above  20  or  30  feet  long.  If  the  field  is  extensive,  several  ot  these  stacks 
I^e  formed  at  regular  distances ;  the/are  carefully  thatched  at  top,  and  the  ends^which 
we  mi'te  perpendicular,  are  kept  up  by  means  of  two  strong  poles  driven  perpendicularly 
^to^  he  |roS  The^e  stacks  look  from  a  distance  like  short  mud  walls,  ^«ch  as  are 
^en  in  Devonshire.  This  is  the  method  adopted  by  those  who  defer  the  steeping  till 
Another  season  Some  carry  the  flax  as  soon  as  it  is  dry  under  a  shed,  and  take  ott  the 
eapsu^^^^^  rippl-g.  -l^i<^^  i«  drawing  the  flax  through  amron  comb 

fixed  in  a  block  of  wood  f  the  capsSles  which  are  too  large  to  pass  between  he  teeth  of 
^e  comb  are  thus  brokei  off  an'd  fall  into  a  basket  or  cloth  below  Sometame^  it  the 
eaosules  are  brittle,  the  seed  is  beaten  out  by  means  of  a  flat  wooden  bat  like  a  small 
Set  bat  The  bundles  are  held  by  the  root  end,  and  the  other  end  is  laid  on  a  board 
Tnd  turned  round  with  the  left  hand  while  the  right  with  the  bat  breaks  the  capsules 
lid  the  linseed  falls  on  a  cloth  below.  The  flax  may  then  be  immediately  steeped :  but 
Jhe  mo  t  expelenccd  flax-steepers  defer  this  operation  till  the  next  season  In  li^  case 
it  is  put  in  barns,  and  the  seed  is  beat  out  at  leisure  in  winter.  W  hen  flax  s  housed  care 
must^be  taken  that  it  be  thoroughly  dry  ;  and  if  the  seed  is  left  on  -Inch  is  an  advan- 
t.age  to  it,  mice  must  be  guarded  against,  for  they  are  very  fond  of  linseed,  and  would 
Boon  take  away  a  good  share  of  the  profits  by  their  depredations. 

Steeping  the^flax  is  a  very  important  process  which  requires  experience  and  skill  to 
do  it  p?operlv     The  quantity  ahd  coloir  depend  much  on  the  mode  of  steeping,  and 
ie  st?eT|th  S  the  fib?e  may  "be  injured  by  an'  injurious  mode  of  f  ^forming  this  o^ra- 
tion     The  obiect  of  steeping  is  to  separate  the  bark  from  the  woody  part  of  the  stem,  by 
dissolv  1^  a  glutinous  m^attlr  which  causes  it  to  adhere  and  -^l\^^'''^rVZZTTa 
vessels  which  are  interwoven  with  the  l?ngitudinal  fibres  and  keep  thojnto^^^^^^^^^ 
kind  of  web.     A  certain  fermentation  or  incipient  putrefaction  is  excited  b^  the  steeping, 
which  must  be  carefully  watched  and  stopped  at  the  right  time     The  usual  mode  of 
«^eepln"  is  to  place  the\undles  of  flax  horizontally  in  the  shallow  pool  or  di  ches  of 
.tagnaift  water,  keeping  them  under  water  by  means  of  poles  or  boards  with  stones  or 
TefZs  laid  upon  them^.     AVater  nearly  putrid  was  supposed  the  most  efficacious ;  and 
Te  mud  is  often  laid  over  the  flax  to  accelerate  the  decomj^osition,  but  this  has  been 
found  to  s  ain  the  flax,  so  thatit  was  very  difficult  to  bleach  itor  thelmenmadefro^^^^ 
afterwards.     The  method  adopted  by  the  steepers  of  Cour  ray,  where  steeping  flax  is  a 
ktinct  trade,  is  different.     The  bunies  of  flax  are  placed  alternately;  ^j^^^^^»^;^^^^^^^^^^^ 
of  the  one  to  the  root  end  of  the  other,  the  latter  projecting  a  few  mches ;  as  many  ot 
?hese  are  tied  together  near  both  ends  as  form  a  thck  bundle  -^-fjj^f'l^'^^^^^^^^^ 
A  frame  made  of  oak-rails  nailed  to  strong  upright  pieces  in  the  form  of  a  box  10  feet 
square  and  4  deep,  is  filled  with  these  bundles  set  upright  and  closely  packed.  •  The 
lole  is  then  imm^^rsed  in  the  river,  boards  loaded  with  stones  being  Placed  upon  the 
flax  till  the  whole  is  sunk  a  little  under  the  surface  of  the  water     Ihe  bottom  does  not 
reach  the  ground,  so  that  the  water  flows  over  and  under  it.     There  are  posts  di.  ven  m 
the  river,  to  keep  the  box  in  its  place,  and  each  steeper  has  a  certain  portion  of  the  bank 
which  i    a  valuable  property.^  The  flax  takes  somewhat    onger  tin^yn/eep^^^^ 
this  manner  than  it  does  in  stagnant  or  putrid  water,  and  it  ,s  asserted  by  tl>ose  who 
adhere  to  the  old  method  that  the  flax  loses  more  weight ;   but  the  colour  ^^^o  much 
finer,  that  flax  is  sent  to  be  steeped  in  the  Lys  from  every  part  of  Flanders.     When  it  s 
Bupposed  that  the  flax  is  nearly  steeped  sufficiently,  which  depends  on  the  temperature 
of  the  air,  the  flax  being  sooner  steeped  in  warm  weather  than  in  cold,  it  ^«  '^-^ajnined 
carefully  every  day,  and  towards  the  latter  part  of  the  time  several  times  in  the  day.  m 
order  to  ascertain  whether  the  fibres  really  separate  from  the  wood  the  whole  length  of 
the  stem.     As  soon  as  this  is  the  case  the  flax  is  taken  out  of  the  water :    even  a  few 
hours  more  or  less  than  is  necessary  will  make  a  difference  in  the  value  of  the  flax     If 
it  is  not  steeped  enough,  it  will  not  be  easily  scutched,  and  the  wood  will  adhere  to  it   It 
it  has  been  t^o  long  in  the  water,  its  strength  is  diminished  and  more  of  it  breaks  "jto  tow. 
The  bundles  are  now  untied,  and  the  flax  is  spread  evenly  in  rows  ^^'fpj'^^^j^^'-^^l 
each  other  on  a  piece  of  clean  smooth  grass  which  has  been  mown  or  fed  off  c^os^  ^ine 
weather  is  essential  to  this  part  of  the  process,  as  rain  would  now  much  injure  the  fla^c 
it  is  occasionally  turned  over,  which  is  done  dexterously  by  pushing  *\  l«"g  ^^^^f^^  J«^ 
nnder  the  rows,  and  taking  up  the  flax  neai'  the  end  wkch  overlaps  the  next  row  and 
turning  it  quite  over.     Thus,' when  it  is  all  turned,  it  ovej'laps  as  before  but  in  the 
contra!-y  direction.     It  remains  spread  out  upon  the  grass  for  a  fortnight,  more  or  less 
according  to  the  season,  till  the  woody  part  becomes  brittle,  and  some  of  the  finest  fibres 


ii  i  i 


FLAX. 


793 


separate  from  it  of  their  own  accord.  It  is  then  taken  up,  and  as  soon  as  it  is  quite  dry 
it  18  tied  up  again  in  bundles,  and  carried  into  a  barn  to  be  broken  and  heckled  at 
leisure  during  the  winter.  . ..        . 

The  total  annual  production  of  flax  in  Belgium  amounts,  by  a  recent  estimation,  to 
about  forty  millions  of  pounds.  Its  total  value  is  calculated  at  about  two  mimons  and 
a  half  sterling.  This  flax  is  of  very  superior  quality,  and  is  principally  emplo)  ^^^^ 
the  manufacture  of  the  finest  class  of  fabrics.  Attempts  are  being  now  made  on  a  large 
scale  to  cultivate  this  important  plant  in  England  and  Ireland.  Belgium  exports  about 
five  millions  of  pounds  of  flax  to  England.  That  flax  grown  in  the  Courtray  district  is 
universally  considered  to  be  of  the  finest  quality. 

Flax  Weaving  Loom.-a  a  a.  Fig.  648.,  frame  of  loom ;  b.  beam  on  which  he  yarn 
for  warp  is  wound ;  c  cloth  receiving  beam ;  d  driving  pulleys  and  fly-wheel ,  e  hana 


rail  for  supporting  the  reed  ;  r  swords  of  supports  of  going  part;  o  picking  sticks  lor 
drivine  the  shuttle  ;  ii  leather  straps  for  connecting  the  picking  sticks  with  theiF 
actuating  levers  l;  m,  x,  jaws  of  a  clamp  to  cause  the  retaining  friction  on  the  collars 
of  the  beam  b,  by  which  friction  the  quantity  of  weft  is  regulated ;  o  end  of  lever 
bearing  the  weight  by  which  the  jaws  are  brought  together ;  r,  lever,  keyed  at  one  end 
to  the  upright  shaft  ^  and  connected  with  the  other  to  the  fulcrum  of  the  weighted 
lever  o  •  R  lever,  one  end  of  which  is  also  keyed  to  the  upright  shaft  q,  and  the  other  is 
Drovided  with  a  wood  sole,  and  is  pressed  by  a  strong  spring  against  the  yarn  wound 
Spon  the  beam  b.  It  will  be  seen  that,  as  the  yarn  is  taken  off  the  beam  b  and  it« 
diameter  consequently  reduced,  the  lever  p  moves  the  tulcrum  of  the  weighted  lever  o, 
and  thus  rec'ulates  the  pressure  upon  the  clamps  m  and  n,  causing  an  equal  tension 
UDon  the  vam  from  the  full  to  the  empty  beam  ;  a  treddles,  actuated  by  the  cams  6 
driven  bv  the  wheels  c,  d,  c,  from  the  picking  shaft/;  g,  g  shuttle  boxes  at  each  end 
of  the  eoing  part ;  /»,  h  arrangement  of  levers  to  conduct  ec^ually  each  end  of  the  geers 
i.  I  This  loom  has  also,  in  addition  to  the  ordinary  stopping  arrangement  connected 
with  the  shuttle,  one  also  for  relaxing  the  reed  in  case  the  shuttle  should  be  arrested 
in  its  course  across  the  warp,  whereby  the  danger,  ordinarily  incurred  by  that  accident, 
of  breaking  many  threads  in  the  warp,  is  avoided ;  it  will  also  be  seen  that  the  bands 
called  picking  barids  are  supereeded  by  the  ends  of  the  picking  levers  striking  the  shuttJe 
direct ;  thus,  by  these  improvements,  drUls  are  currently  woven  m  this  loom  at  the  rate 
of  12o'to  130  picks  per  minute. 


Imports  of  flax  and  tow,  or  codilla  of  hemp  and 

flax  -  - 

Linen  yarn  exported    -     ^   ,,.",.    ". 
Linen  manufactures  exported  (including  linen    - 

yarn,  881,312/.  and  935,939/.)  declared  value  - 

Vol.  L  fi  ^ 


cwts. 
lbs. 


1850 

1,822,918 
18,220,688 


1851 

1,194,184 
18,518,273 


£    4,839,779  5,053,792 


II 


i 
I 

At 


i  i 
!  c 


I 


794 


FLINT. 


FLINT.  (Pierre  ci  fusil,  Fr. ;  Fmcrstein,  Germ.)  The  fracture  of  this  fossil  « 
nerfecilv  conchoidal,  sometimes  glossy,  and  sometimes  dull  on  the  surface.  It  ,s  y^vy 
Sard  but  breaks  eadly,  and  affords  very  sharp-edged  splintery  fragments;  whence  it  is 
a  s^one  which  strikes  most  copious  sparks  with  steel.  It  is  feebly  translucid  has  so  fine 
LThlogeneous  a  texture  as  to  beAr  polishing,  but  possesses  little  lustre  Its  colours 
are  very  Various,  but  never  vivid.  The  blackish-brown  flint  is  that  usually  found  m 
tie  whL  chalk  It  is  nearly  black  and  opaque,  loses  its  colour  in  the  fire,  and  becomes 
cmTsrwhUe  and  perfectly'  opaque.  Flints  occur  almost  always  in  nodules  or  tuber- 
fulL  concretions  of^varioui  and  very  irregular  forms.  These  nodules,  distributed  in 
strata  aronrthe  chalk,  alongside  of  one  another  and  almost  in  contact,  form  extensive 
beds  inTerrupted  indeed,  by  a  multitude  of  void  spaces,  so  as  to  present,  if  freed  from 
the  eaHhrma^^^^^^^^^  i"  whi^h'they  are  imbedded,  a  speciesof  network  with  meshes,  very 
irrpo-nlarboth  in  form  and  dimension.  ,  , 

S  nodule  of  sUex,  especially  those  found  in  the  chalk,  are  not  always  homogeneouB 
and  solid  Sometmes  there  is  Remarked  an  organic  form  towards  their  centre,  as  a 
madr^po^e  orTsS  which  seems  to  have  served  as  their  nucleus ;  occasionally  the 
Sntre^is  hollow  and  ts  sides  are  studded  over  with  crystals  of  quartz,  carbonate  of 
iron,  pyritetrncre^^^  silex  or  calcedony,  filled  with  pulverulent  silica  nearly  pure, 

or  silex  mixed  with  sulphur ;  a  very  singular  circumstance. 

Flints  are  observed  to  be  generally  humid  when  broken  imrnediately  after  being  dug 
out  of  the  ground;  a  proplrty  which  disappears  after  a  short  exposure  to  the  air. 
When  dried^tney  beconre  more'brittle  and  more  splintery,  and  sometimes  their  surfaces 
eat  covered  at  old  fractures  with  a  thin  film  or  crust  of  opaque  silex. 
^Flints  calcined  and  ground  to  a  powder  enter  into  the  composition  of  all  sorts  of  fine 

^'^Th^nrxU^iportant  application  of  this  siliceous  substance  i«  ^^  th«/ormation  of  gun. 
flints  for  which  purpose'^it  must  be  cut  in  a  peculiar  manner  The  following  characters 
d  stineuLh  good  iiint  nodules  from  such  as  are  less  fit  for  being  manufactured.  The 
best Te  somewhat  convex,  approaching  to  globular;  those  which  are  very  irregular, 
knobbld  branlhed  and  tuberose,  are  generally  full  of  imperfection.  Good  nodules 
Sm  weigh  more  than  20  pounds ;  when  less  than  2,  they  are  not  worth  the  working 
^eHhou  d  have  a  greasy  lustre,  and  be  particularly  smooth  and  fine  grained.  The 
SoL  X  vary  from  honey-yellow  to  blackish-brown,  but  it  should  be  uniform 
?hrouZut  tSmp.  and  the  translucency  should  be  so  great  as  to  render  letters  legible 
through  a  sli^^^^^  one-fiftieth  of  an  inch  thick,  laid  down  upon  the  paper.    The 


FLINT. 


795 


fracture  should  be  perfectly  smooth,  uniform,  and  slightly  conchoidal ;  the  last  property 
being  essential  to  the  cutting  out  of  perfect  gun  flints. 

Four  tools  are  employed  by  the  gun-flint  makers. 

First,  a  hammer  or  mace  of  iron  with  a  square  head,  from  1  to  2  pounds  weight,  with 
a  handle  7  or  8  inches  long.  The  tool  is  not  made  of  steel,  because  so  hard  a  metal 
would  render  the  strokes  too  harsh,  or  dry,  as  the  workmen  say.  and  would  shatter  the 
nodules  irregularly,  instead  of  cutting  them  with  a  clean  conchoidal  fracture. 

Second,  a  hammer  with  2  points,  made  of  good  steel  well  hardened,  and  weighing 
from  10  to  16  ounces,  with  a  handle  7  inches  long  passing  through  it  in  such  a  way 
that  the  points  of  the  hammer  are  nearer  the  hand  of  the  workman  than  the  centre  of 
gravity  of  the  mass. 

Third,  the  disc  hammer  or  roller,  a  small  solid  wheel  or  flat  segment  of  a  cylinder, 
parallel  to  its  base,  only  two  inches  and  a  third  in  diameter,  and  not  more  than  12 
ounces  in  weight.  It  is  formed  of  steel  not  hardened,  and  is  fixed  upon  a  handle  6 
inches  long,  which  passes  through  a  square  hole  in  its  centre. 

Fourth,  a  chisel  tapering  and  bevelled  at  both  extremities,  7  or  8  inches  long,  and  2 
inches  broad,  made  of  steel  not  hardened  ;  this  is  set  on  a  block  of  wood,  which  serves 
also  for  a  bench  to  the  workmen.  To  these  4  tools  a  file  must  be  added,  for  the  pur- 
pose of  restoring  the  edge  of  the  chisel  from  time  to  time. 

After  selecting  a  good  mass  of  flint,  the  workman  executes  the  four  following  oper- 
ations on  it 

1.  He  breaks  the  block.  Being  seated  upon  the  ground,  he  places  the  nodule  of  flint  on 
his  left  thigh,  and  applies  slight  strokes  with  the  square  hammer  to  divide  it  into  smaller 
pieces  of  about  a  pound  and  a  half  each,  with  broad  surfaces  and  almost  even  fractures. 
The  blows  should  be  moderate,  lest  the  lump  crack  and  split  in  the  wrong  direction. 

2.  He  cleaves  or  chips  the  flint.  The  principal  point  is  to  split  the  flint  well,  or  to 
chip  off  scales  of  the  length,  thickness,  and  shape  adapted  for  the  subsequent  formation 
of  gun-flints.  Here  the  greatest  dexterity  and  steadiness  of  manipulation  are  necessary ; 
but  the  fracture  of  the  flint  is  not  restricted  to  any  particular  direction,  for  it  may  be 
chipped  in  all  parts  with  equal  facility. 

The  workman  holds  the  lump  of  flint  in  his  left  hand,  and  strikes  with  the  pointed 
hammer  upon  the  edges  of  the  great  planes  produced  by  the  firet  breaking,  whereby  the 
white  coating  of  the  flint  is  removed  in  small  scales,  and  the  interior  body  of  the  flint 
is  laid  bare ;  after  which  he  continues  to  detach  similar  scaly  portions  from  the  clean 
mass. 

These  scaly  portions  are  nearly  an  inch  and  a  half  broad,  two  inches  and  a  half 
long,  and  about  one-sixth  of  an  inch  thick  in  the  middle.  They  are  slightly  convex 
below,  and  consequently  leave  in  the  part  of  the  lump  from  which  they  were  separated 
a  space  slightly  concave,  longitudinally  bordered  by  two  somewhat  projecting  straight 
lines  or  ridges.  The  ridges  produced  by  the  separation  of  the  first  scales  must  naturally 
constitute  nearly  the  middle  of  the  subsequent  pieces ;  and  such  scales  alone  as  have 
their  ridges  thus  placed  in  the  middle  are  fit  to  be  made  into  gun-flints.  In  this  man- 
ner the  workman  continues  to  split  or  chip  the  mass  of  flint  in  various  directions,  until 
the  defects  usually  found  in  the  interior  render  it  impossible  to  make  the  requisite  frac- 
tures, or  until  the  piece  is  too  much  reduced  to  sustain  the  smart  blows  by  which  the 
flint  is  divided. 

3.  He  fasldous  the  gun-flints.  Five  different  parts  maybe  distinguished  in  a  gun- 
flint.  1.  The  sloping  facet  or  bevel  part,  which  is  impelled  against  the  hammer  of  the 
lock.  Its  thickness  should  be  from  two  to  three  twelfths  of  an  inch  ;  for  if  it  were 
thicker  it  would  be  too  liable  to  break ;  and  if  more  obtuse,  the  scintillations  would  be 
less  vivid.  2.  The  sides,  or  lateral  edges,  which  are  always  somewhat  irregular. 
3.  The  back  or  thick  part  opposite  the  tapering  edge.  4.  The  under  surface,  which  is 
smooth  and  rather  concave.  And  5.  The  upper  face,  which  has  a  small  square  plane 
between  the  tapering  edge  and  the  back,  for  entering  into  the  upper  claw  of  the  cock. 

In  order  to  fashion  the  flint,  those  scales  are  selected  which  have  at  least  one  of  the 
above-mentioned  longitudinal  ridges ;  the  workman  fixes  on  one  of  the  two  tapering 
borders  to  form  the  striking  edge,  after  which  the  two  sides  of  the  stone  that  are  to  form 
the  lateral  edges,  as  well  as  the  part  that  is  to  form  the  back,  are  successively'  placed  on 
the  edge  of  the  chisel  in  such  a  manner  that  the  convex  surface  of  the  flint  which  rests 
on  the  forefinger  of  the  left  hand,  is  turned  towards  that  tool.  Then  with  the  disc  ham- 
mer he  applies  some  slight  strokes  to  the  flint  just  opposite  the  edge  of  the  chisel  uuder- 
ueatli,  and  thereby  breaks  it  exactly  along  the  edge  of  the  chisel. 

4.  Tlie  finishing  operation  is  the  trimming^  or  the  process  of  giving  the  flint  a  smootli 
and  equal  edge ;  this  is  done  by  turning  up  the  stone  and  placing  the  edge  of  its 
tapering  end  upon  the  chisel,  in  which  position  it  is  completed  by  five  or  six  slight  strokes 
of  the  disc  hammer.  The  whole  operation  of  making  a  gun-flint,  which  I  have  used  so 
many  words  to  describe,  is  performed  in  less  than  one  minute.  A  good  workman  is  able 
to  manufacture  1,000  good  chips  or  scales*  in  a  day  (if  the  flint-balls  be  of  good  quality)^ 

6X2 


■H 


"796 


FLOUR  OF  WHEAT. 


FLY  POWDER. 


V97 


or  500  gun-flints.     Hence,  in  the  space  of  three  days,  he  can  easily  cleave  and  finish 

'^T'::^:^n:i^^^^^^  for  scarcely  more  than,  half  the  scales  are 

.o^L^and  Sy  ha?f  the  mass  in  the  best  flints  is  incapable  of  being  ch.pped  out ;  so 
?hrt\  seldom  happens  that  the  largest  nodules  furnish  more  than  60  g"";fl>nt8. 
^ints  form  exceUent  building  materials ;  because  they  give  a  firm  hold  to  the  mortar 
Wh.fr  Sr^Srlv  rough  surfaces,  and  resist,  by  their  nature,  every  vicissitude  of 
tCther.     ThTcou^ties  of  Kent,  Essex,  Suftblk,  an'd  Norfolk,  contain  many  substantial 

'^'^OOrA^"^"'^^^^^        given  by  the  Cornish  miners  to  a  vein  of  clay-stone,  often 

?rnrPvtouslv  brushed  over  ..ith  glue-size,  and  rubbed  smooth  with  pumice  stones. 
^hrfrundftLr^ai^^^^^^^^^  ^.ith  nnseed  oil  and  ochre,  or  any  cheap  -lo"""^  "-"^;; 
i«  fin  tl^ok  to  be  applied  by  the  brush,  and  is  therefore  spread  evenly  by  a  long  narrow 

their  grain  crossing  one  ^l^o|tier  ^  f^^^^^^  Ire  cut  awav  that  correspond  to  the  im- 

slices  between.     Applied  in  this  ^»i' *« '*'3  ^'1'"^  of  the  block  whiih  takes  up 

%t^7lZ  ^'S;^tr.  is  the  fluia  glass  floating  iipon  the  iron  produced 

'^^^^^^Jli:i!^^rtZ^i:f^^'^^''  -™e   given  to  the 
FLObb-felLK  y^«<>?f"^'     v!I^.ffTn  tho  filature  of  the  cocoons,  which  is  carded  like 
portions  of  ravelled  silk  broken  ''%^'' ^^'^^^^^^^^  for  making  bands,  shawli, 

Cotton  or  wool,  and  spun  ^"to  a  soft  coar^e  >  arn  or  tln-e^^^^^^^^  obtained,  must  be 

socks,  and  other  common  ^^^^  fabrics^    The  flo^ 

steeped  in  water,  and  then  subjected  to  P^ff^^^^^^' "'j^'^^^^'^,^^       After  being  dned  it  is 
Which  rendci-s  it  too  harsh  anct  short  [^^  .tj^^.f ^i"^\^f  J^h  "he  hands.     It  is  now  ready 

made  still  more  pliant  by  j:«r^^^g.\^^"^.^,"l^CoN  Manufa^^^^^^^        It  is  spun  upo^ 
■to  be  submitted  to  the  carding  engine,     (teee  Cotton  j>ianli.aoiu      ;  r 

the  flax  wheel.  ^„^^„ii^rwpnr  clothes  of  homespun  floss  silk.    Of 

The  female  peasants  of  Lombardy  generally  wear  ""^^y'f.^^^^  j^^^^  been  pro- 

late years,  by  \mproyed  processes.  Pretty  fne  fabrics  of  this  ^^^^^J^J  /^J^^^^f?  h^ 
duced,  both  in  England  and  France.     M.  ^4^^,'  ^f^i^>^"''  JJ  ,^^^  of  scarfs  and 

French  national  exhibitions  of  the  objects  of  industry,  a  f  ^J^^J  f/jf  > 
^Sare  shawls,  on<^rre  d.  soie,  closely  ---^^-^^^  ^^^^^^^  or  cerealia.     See 

FLOUR  ;  the  finely  ground  meal  ot  wheat,  and  oi  any  omer  i.uiii!> 

^'^^St'b  r>v  WTIKAT  AdulUration,  of,  to  detect.— ^e  first  method  is  by  specific 
JlS^\?loTJ^Z^iiMTi^^  ia  frequently  done  in  F™"-. --^^^ 
|,Wcblontai,fs  one  pound  of  wheat  flour  will  contain  one  poand  and  a  hajf  of  the  fec-J^ 

^•'^Lrlllerrettd^rbytLTJ^^^^^ 

.ample  will  afl-ord,  by  the  process  prescribed  under  the  article  Bread. 

'^Z'^^^r^ir^^^^:^'^^^  .heat  «o„.  of  .  fine  orange  yellow, 
whereas  it  aftects  the  coloui'  neither  of  fecula  nor  starch. 


2nd.  Pure  muriatic  acid  colours  good  wheat  flour  of  a  deep  violet,  but  dissolves 
fecula  or  starch,  and  forms  with  it  a  light,  colourless,  viscous  fluid,  decomposable  b;r 
alkalis.  It  may  also  be  observed,  that  as  fecula  absorbs  less  water  than  flour,  this 
affords  a  ready  means  of  detection.  .      .    .,•  * 

The  adulteration  with  bean  or  pea  flour  may  be  detected  by  pouring  boiling  water 
upon  it,  which  developes  the  pecuhar  smell  of  these  two  substances. 

FLUWEPwS  {Fleurs,  Ft.;  Blwnen,  Germ.)  of  benzoin,  of  sulphur,  of  zinc,  <fec.,  is  the 
appellation  given  by  the  older  chemists  to  such  substances  as  were  obtained  in  a  pul- 
verulent or  rather  minutely  crystalline  form  by  the  process  of  sublimation. 

FLOWERS,  ARTIFICIAL,  ^L\NUFACTURE  OF.  The  art  of  representing  by- 
flowers,  leaves,  plants,  <fee.,  vegetable  nature  in  her  ornamental  productions,  consti- 
tutes the  business  of  the  artificial  florist.  The  Italians  appear  to  have  been  the  first 
people  in  Europe  who  excelled  in  the  art  of  making  artificial  flowers ;  but  of  late  years 
the  French  have  been  most  ingenious  in  this  branch  of  industry. 

Ribbons  folded  in  different  forms  and  of  different  colours  were  originally  employed 
for  imitating  flowers,  by  being  attached  to  wire  stems.  This  imitation  soon  gave  way 
to  that  by  feathers,  which  are  more  delicate  in  texture,  and  more  capable  of  assuming 
a  variety  of  flower-like  figures.  But  a  great  difficulty  was  encountered  in  dyeing  them 
with  due  vivacity.  The  savages  of  South  America  manufacture  perfect  feather  flowers, 
derived  from  the  brilliant  plumage  of  their  birds,  which  closely  resemble  the  products 
of  vegetation.    The  blossoms  and  leaves  are  admirable,  while  the  colours  never  fade. 

The  Italians  employ  frequently  the  cocoons  of  the  silk- worm  for  this  purpose  ;  these 
take  a  brilliant  dye,  preserve  their  colour,  and  possess  a  transparent  velvety  appear- 
ance suitable  for  petals.  Of  late  years,  the  French  have  adopted  the  finest  cambric  for 
making  petals,  and  the  taffeta  of  Florence  for  the  leaves.  M.  de  Bernardiere  employs 
whalebone  in  very  thin  leaves  for  artificial  flowers ;  and  by  bleaching  and  dyeing  them  of 
various  hues,  he  has  succeeded  in  making  his  imitations  ot  nature  to  be  very  remarkable. 

The  colouring  matters  used  in  flower  dyeing  are  the  following :  — 

For  red ;  carmine  dissolved  in  a  solution  of  carbonate  of  potash. 

For  blue :  indigo  dissolved  in  sulphuric  acid,  diluted  and  neutralised  in  part  by 

Spanish  whitening.  ^     ,         .  .       ,      .         ^  ^  ^    ^ 

For  bright  yellow;   a  solution  of  turmeric  in  spirit  of  wine.     Cream  of  tartar 

brightens  all  these  colours. 

For  violet ;  archil,  and  a  blue  bath. 

For  lilac;  archil.  . 

Some  petals  are  made  of  velvet,  and  are  coloured  merely  by  the  application  of  the 

finger  dipped  in  the  dye. 

FLUATES,  more  properly  fluorides  (Eng.  and  Fr. ;  Flussaure,  Germ.j ;  compounds 
of  fluorine  and  the  metals;  as  fluor  spar,  for  example,  which  consists  of  fluorine  and 

calcium.  ^         v     ,,,.  •        •        ^      r^ 

FLUOR  SPAR.  {Chaux  fluatee,  Fr.;  Spath  fluor,  Germ.)  This  mineral  often 
exhibits  a  variety  of  vivid  colours.  It  crystallizes  in  the  cubic  system  ;  with  regular 
octahedral  and  tetrahedral  cleavages;  spec.  grav.  3'1  to  3-2;  scratches  calc  spar,  but 
is  scratched  by  a  steel  point ;  usually  phosphorescent  with  heat ;  fusible  at  the  blow- 
pipe into  an  opaque  head ;  acted  on  by  the  acids,  with  disengagement  of  a  vapour 
which  corrodes  glass;  its  solution  affords  precipitates  with  the  oxalates,  but  ni;t  with 
ammonia.     Its  constituents  are,  fluorine,  48-13  ;  calcium,  51 '87  in  100. 

Fluor  spar  occurs  subordinate  to  metallic  veins  ;  as  to  those  of  lead,  ia  Derbyshire; 
of  tin,  in  Saxony  and  Bohemia ;  but  it  is  found  also  in  masses  of  veins,  either  in  crys- 
talline rocks,  associated  with  quartz,  heavy  spar,  Ac,  as  in  Auvergne,  Forez,  A^osgea, 
Norberg  in  Sweden  ;  Norway ;  Petersburg ;  near  Hall ;  Gourock,  in  Scotland,  &c. ;  or 
among  secondary  limestones,  slates,  and  sandstones,  in  Derbyshire,  Cumberland,  Corn- 
wall and  New  Jei-sey.  It  exists  also  in  the  amygdaloids  of  Scotland,  and  in  the  vol- 
canic products  of  Mount  Somma  at  Vesuvius.  The  variously  coloured  specimens, 
called  Derbyshire  spar,  are  worked  upon  the  turning  lathe  into  vases  and  other  orna- 
mental objects.  .    .      .^  ,  11      i.  *• 

FLUX,  (Eng.  and  Fr. ;  Iluss,  Germ.)  signifies  any  substance  capable  of  promoting 
the  fusion  of  earihs  or  metallic  ores  by  heat.  White  flux  is  the  residuum  of  the  defla- 
gration in  a  red  hot  crucible,  of  a  mixture  of  two  parts  of  nitre,  and  one  of  cream  of 
tartar.  It  is  in  fact  merely  a  carbonate  of  potash.  Black  flux  is  obtained  when  equal 
parts  of  nitre  and  tartar  are  deflagrated.  It  owes  its  colour  to  the  carbonaceous  matter 
of  the  tartaric  acid,  which  remains  unconsumed ;  the  quantity  of  nitre  being  too  small 
for  that  purpose.  The  presence  of  the  charcoal  renders  this  preparation  a  convenient 
flux  for  reducing  calcined  or  oxidized  ores  to  the  metallic  state  Limestone,  fluor-spar, 
borax,  and  several  earthy  or  metallic  oxides  are  employed  as  fluxes  in  metallurgy. 

FLY  POWDER ;  the  black  coloured  powder  obtained  by  the  spontaneous  oxidize- 
mcnt  of  metallic  arsenic  in  the  air. 


IRREGULAR  PAGINATION 


798 


FORMULA  CHEMICAL. 


FODDER ;  is  the  name  of  a  weight  by  which  lead  and  some  other  metals  arc  sold 
in  this  country.  Its  varies  in  its  amount  in  different  parts  of  the  kingdom ;  being  in 
Northumberland  estimated  at  21  cwts,,  and  in  other  counties  22,  23  or  even  more  cwta. 

FO^'DUS;  is  the  name  given  by  the  French  to  a  particular  style  of  caliijo  printing 
resembling  the  rainbow,  in  which  the  colours  are  graduated  or  melted  (fondus)  into 
one  another,  as  in  the  prismatic  spectrum.  See  Papee  Hanging,  for  a  description  of 
the  process. 

FORGE;  (Eng.  andFr.;  Feuer,  Germ.)  is  the  name  either  of  the  furnace,  where 
wrought  iron  is  hamniered  and  fashioned  with  the  aid  of  heat,  or  the  great  workshop 
where  iron  is  made  malleable.  The  former  is  called  a  smith's  forge,  the  latter  a 
shingling  mill     See  Iron. 

I'tg.  649.  represents  a  portable 
truck  forge  of  a  very  commodious 
construction,  a  is  the  cylindric 
leather  bellows,  pressed  down  by 
a  helical  spring,  and  worked  by 
means  of  the  handle  at  b,  which ' 
moves  the  horizontal  shaft  c,  with 
its  two  attached  semi-circular" 
levers  and  chains,  d,  is  the  pipe 
which  conducts  the  blast  to  the 
nozzle  at  e.  The  hearth  may  be 
covered  with  a  thin  fire-tile  or 
with  cinders,  f,  is  a  vice  fixed  to 
the  strong  rectangular  trame. 
This  apparatus  answers  all  the  or- 
dinary purposes  of  a  smith's  forge ; 
and  is  peculiai'ly  adapted  to  ships, 
and  to  the  execution  of  engineer- 
ing jobs  upon  railways,  or  in  the 
country.  The  height  is  2  feet  6 
inches;  the  length  is  2  feet  9 
inches  ;  the  width  2  feet  Weight 
about  2  cwt. 

FORGERY,  PREVENTION.— Forgeries  of  Bank  cheques  and  other  cash  documents 
are  proposed  to  be  prevented  under  the  patent  recently  granted  to  Messrs.  Henry 
Glynn  and  Rudolph  Appel.  They  prepare  paper  by  mixing  its  pulp  with  solution  of 
nitrate  or  sulphate  of  copper,  to  which  mixture  alkaline  saline  matter  is  added,  to 
produce  a  cupreous  precipitate  (phosphate  of  sode  being  preferred),  so  that  reddened 
litimus  paper  will  be  rendered  blue  by  it.  One  ounce  of  nitrate  of  copper  is  sufficient 
for  two  gallons  of  the  pulp,  or  even  more  if  the  cupreous  colour  is  objectionable. 
Tlie  pulp  is  to  be  then  washed  with  water.  A  mixture  of  equal  i>arts  of  white 
soft  soap  and  old  palm  oil  is  to  be  dissolved  in  boiling  water,  using  half  a  pound  of 
soap  to  one  gallon  of  water.  Into  this  saponaceous  solution,  the  paper  impregnated 
with  the  said  pulp  is  to  be  dipped,  and  then  sized.  They  also  prevent  a  transfer 
being  taken  with  paper,  by  washing  it  with  solution  of  sulphate  of  copper,  drying 
it,  and  dipping  it  in  phosphate  of  soda  strong  enough  to  convert  the  sulphate  into  a 
phosphate. 

FORMIATES ;  are  compounds  of  formic  acid,  with  the  salifiable  bases.  Many  of 
them  are  susceptible  of  crystallization. 

FORMIC  ACID ;  {Acide  Formique,  Fr. ;  Ameimnsaure,  Germ.)  exists  in  the  bodies 
of  wood  ants,  associated  with  the  malic  or  acid  of  apples.  The  artificial  formation 
of  this  animal  secretion,  is  one  of  the  most  remarkable  triumphs  of  modern  chemistry. 
If  10  parts  of  tartaric  acid,  14  of  black  oxide  of  manganese,  15  of  concentrated  sul- 
phuric acid,  and  from  20  to  30  of  water  be  mixed  and  distilled  in  a  retort,  formic  acid 
will  be  the  liquid  product;  while  carbonic  acid  will  be  disengaged.  It  may  also  be 
generated  from  other  mixtures.  This  acid  is  transparent  and  colourless,  of  a  pungent 
sour  smell,  a  strongly  acid  taste,  of  specific  gravity  1-1168  at  60°  F.,  and  may  be 
rc-distiiled  without  suffering  any  change.  It  contains  in  its  most  concentrated  form 
1 9f  per  cent  of  water.  The  dry  acid,  as  it  exists  in  the  formiat€&,  is  composed  of 
32-54  carbon,  2*68  hydrogen,  and  64-78  oxygen:  or  of  two  volumes  carbonic  oxide 
gas,  and  one  volume  of  vapour  of  water.  It  reduces  the  oxides  of  mercury  and  silver 
to  the  metallic  state.     It  has  not  hitherto  been  applied  to  any  use  in  the  arts. 

FORMULA  CHEMICAL,  are  symbols  representing  the  different  substances,  simple 
and  compound. 


FORMUL-E,  CHEMICAL. 


801 


Name. 

Formula. 

Oxygen =100 

Hydrogen =1.  | 

Oxygen' 

0 

100-000 

16  026 

Hydrogen         .            .            • 

H 

6-2398 

1-000 

«H 

12-4796 

2-000 

Nilrogea          ,            •            . 

N 

88-518 

14186 

VOX 

177086 

28-372 

Phosphorus      .           •           • 

p 

196-155 

31-436 

«p 

392-310 

68-872 

Chlorine 

CI 

221-325 

35-470 

2C1 

442-650 

70-940 

Iodine  .            •            •            • 

I 

768-781 

123-206 

21 

1537-562 

246-412 

Carbon            •           •           . 

C 

76-437 

12-250 

2C 

152-875 

24-500 

Boroa  •           •                       • 

B 

135-983 

21-793 

2B 

271-966 

43-586 

Silicon .           •           •           • 

8i 

277-478 

44-469 

Selenium          •            •            • 

Se 

494-582 

79  263 

Arsenic            •            •            • 

As 

470-042 

75-329 

2As 

940-084 

150-659 

Chromium        ... 

Cr 

351-819 

56-383 

2Cr 

703-638 

112-766 

Molybdenum    •            • 

Mo 

598-525 

95-920 

Tungstenium  • 

TuorW 

1183-200 

189-621 

Antimony        •           •           . 

Sb 

806-452 

129-243 

2Sb 

1612-904 

258-486 

Tellurium 

Te 

806-452 

129-243 

Tantalum         • 

Ta 

1153-715 

184-896 

2Ta 

2307-430 

369  792 

Titaniam         ,           ,           , 

Ti 

389-092 

62-356 

Gold  (aurum)  .           ,           . 

Au 

1243013 

199-207 

2Au 

2486-026 

398-415 

Platina 

Pt 

1215220 

194-753 

Rhodium 

R 

750-680 

120-305 

2R 

1501-360 

240610 

Palladium        .             . 

Pd 

714-618 

114-526 

Silver  (argentum) 

Ag 

1351-607 

216-611 

Mercury  (hydrargyrus)            . 

Hg 

1265-822 

202-863 

2Hg 

2531-645 

405  725 

Copper  (cuprum)         .           • 

Ca 

395-695 

63415 

2Cu 

791-390 

126-829 

Uranium          .            •            . 

U 

2711-360 

434-527 

x%*              *.t_ 

VXS 

5422-720 

869-154 

Bismuth           .            • 

Bi 

1330-376 

213-208 

2Bi 

2660-752 

426-416 

Tin  (stannum)             •           . 

Sa 

735-294 

117-839 

Lead  (plumbum)          .            . 

Pb 

1294-498 

207-458 

• 

2Pb 

2588-996 

414-917 

Cadmium         •            •            • 

F7  * 

Cd 

696-767 

111-665 

Zinc    .... 

Za 

403-2-26 

64-621 

Nickel              , 

Ni 

369-675 

59-245 

Cobalt 

Co 

368-991 

59-135 

2Co 

737-982 

118-270 

Iron  (fcrrum)  ,            •            , 

Fe 

339-213 

54-363 

^  ^ 

2Fe 

678-426 

108-725 

Manganese      •           •           . 

Mn 

355-787 

57-019 

Cerium            ,           , 

2Mii 

711-575 

114-038 

Ce 

574-718 

92-105 

2Ce 

1149-436 

184-210 

Zirconiam 

Zr 

420-238 

67-348 

vr^d    • 

2Zr 

840-476 

134-696 

yttrium           .           , 

Y 

401-840 

64-395 

Beryllium  (glucinnm) 

Be 

331-479 

53-123 

2Be 

662-958 

106-247 

802 


formulje,  chemical. 


FORMULiG,  CHEMICAL. 


80S 


I 


Name. 

Formula.                    | 

()x>geii=  100. 

IIydropeii=  1. 

Aluminum 

Magnesium 

Calcium 

Strontium 

Baiyt'im 

Lithium 

Natrium  (sodium) 

Kalium  (potassium)     . 

Ammonia 

Cyanogen 

Al 
2A1 
Mg 
Ca 
Sr 
Ba 

T. 
Na 
2\a 

K 

•2.N  210 

2\C 

171-167 

342-234 

158-353 

256-019 

547  285 

856-88 

J  27-757 

290-897 

581-794 

489-916 

214-474 

329  911 

27-431 
54-863 
25-378 
41-030 
87-709 
137-325 
20  474 
46-620 
93-239 
78-515 
34-372 
52-872 

S:-lphurete(l  hydrogen  . 

2HS 

213-644 

34-239 

Hydrochloric  acid 

2HC1 

455-129 

72-940 

Hydrocyanic  acid 

2HNC 

342-390 

54-872 

Water 

211 

112-479 

18-026 

Protoxyde  of  nitrogen  . 

2N 

277-036 

44-398 

Deutoxyde  of  nitrogen 

N 

188-518 

30-212 

Nitrous  acid    . 

2N 

477-036 

76-449 

Nitric  acid       .            . 

2N 

677-036 

108-503 

Hyposulphurous  acid  . 

• 

S 

301-165 

48-265 

Sulphurous  acid           .            • 

•• 

s 

401-165 

64-291 

Hypo«ulphuric  acid 

•  • 

2S 

902-330 

144-609 

Sulphuric  acid               .             • 

••• 

s 

501-165 

80-317 

Phosphoric  acid 

2P 

892-310 

143-003 

Chloric  acid     .             .             • 

2C1 

942-650 

151-071 

Perchloric  acid            .            • 

2C1 

1042-650 

167-097 

Iodic  acid         .             .            • 

21 

2037-562 

326-543 

Carbonic  acid  .            •            • 

•• 

C 

276-437 

44-302 

Oxalic  acid      .            .            • 

••• 

2C 

452-875 

72-578 

Boracic  acid    .             .            . 

2B 

871-966 

139-743 

Silicic  acid       .             .             • 

Si 

577-478 

92-548 

Selenic  acid     . 

•• 

Se 

694-582 

111-315 

Arsenic  acid    . 

•  ■  • 

2As 

1440-084 

230-790 

Protoxyde  of  chrome    . 

•  •• 

2Cr 

1003-638 

160-840 

Chromic  acid  . 

Cr 

651-819 

104-462 

Molybdic  acid              .            . 

Mo 

898-525 

143-999 

Tunslic,  or  wolfram  acid 

W 

1483-200 

237-700 

Oxyde  of  antimony 

••• 

2Sb 

1912-904 

306-565 

Antimonious  acid         •            • 

Sb 

1006-452 

161-296 

2Sb 

2012-904 

322-591 

Antimonic  acid 

2Sb 

2112-904 

338-617 

Name. 


Oxyde  of  tellurium 
Tantaiic  acid  . 
Titanic  acid    . 
Protoxyde  of  gold 
Pcroxyde  of  gold 
Oxyde  of  platina 
Oxyde  of  rhodium 
Oxyde  of  palladium 
Oxyde  of  silver 
Protoxyde  of  mercury 
Peroxyde  of  mercury 
Protoxyde  of  copper 
Peroxyde  of  copper 
Protoxyde  of  uranium 
Peroxyde  of  uranium 
Oxyde  of  bismuth 
Protoxyde  of  tin 
Peroxyde  of  tin 
Oxyde  of  lead . 
Minium  . 

Brown  oxyde  of  lead 
Oxyde  of  cadmium 
Oxyde  of  zinc 
Oxyde  of  nickel 
Oxyde  of  cobalt 
Peroxyde  of  cobalt 
Protoxyde  of  iron 
Peroxyde  of  iron 
Protoxyde  of  manganese 
Oxyde  of  manganese 
Perox)'de  of  manganese 
Manganesic  acid 
Protoxyde  of  cerium 
Oxyde  of  cerium 
Zirconia 
Yttria 
GIncina,  or  berryllia 


Formala. 


Te 
2Ta 
Ti 
2Au 
2Au 
Pt 
2R 
Pd 

M 

2Hg 

Hg 
2Cu 

Cu 
U 
2U 
2iBi 
Sn 
Sn 
Pb 

2Pb 

Pb 

Cd 

Za 
Ni 
Co 

2Co 

Fe 

2F 

Mn 
2Mn 

Mn 
2*Mii 

Ce 

2Ce 

2Zr 
Y 

2Be 


Oxygrea=  100 

.   Hydrogen=l 

1006-452 

161-296 

2607-430 

417-871 

589-092 

94-409 

2586-026 

414-441 

2786-026 

446-493 

1415-220 

226-086 

1801-360 

228-689 

814-618 

130-552 

1451-607 

232-637 

2631-645 

421-752 

1365-822 

218-889 

801-390 

142-856 

495-695 

79-441 

2811-360 

450-553 

5722-720 

917-132 

2960-752 

474-49 

835-294 

133-866 

935-294 

149-892 

1394-498 

223-484 

2888-996 

462-995 

1494-498 

239-511 

796-767 

127-691 

503-226 

80-649 

469-675 

75-271 

468-991 

75-161 

1037-982 

166-349 

439-213 

70-389 

978-426 

156-804 

455-787 

73-045 

1011-575 

162-117 

555-787 

89-071 

1211-575 

194-169 

674-718 

108-132 

1449-436 

232-289 

1140-476 

182-775 

501-840 

80-425 

962-958 

154-325 

804 


FOUNDING. 


. 


Name                                   { 

Formalii. 

Oxygen=100. 

Hydrog«n=l., 

Alnroina          •            •            • 

•  •• 

2A) 

642-334 

t 

109-942 

Magnesia         •            •            • 

Mg 

258-353 

41-404 

Lime    .            «           •            • 

Cft 

356-019 

57-056 

Strontia            •            •            • 

• 

Sr 

647-285 

103-735 

Baryta             •            •            • 

Ba 

956-880 

153-351 

Lithia              •            •            • 

• 

L 

227-757 

36-501 

Natron,  or  soda           •            • 

Nft 

390-897 

62-646 

Peroxyde  of  sodinin     •            • 

2Na 

881-794 

141-318 

Kali,  or  potassa           •            • 

• 

K 

589-916 

94-541 

Peroxyde  of  potassium             . 

••• 

K 

789-916 

126-593 

Sulphate  of  potassa      .            • 

■    ••• 

KS 

1091081 

174-859 

Protosulphate  of  iron  •            • 

FeS 

940-378 

150-706 

Persulphate  of  iron      .             • 

2FeS3 

2481-906 

397-754 

Protochloride  of  iron   .            • 

Fe2Cl 

781-863 

125-303 

Perchloride  of  iron      . 

2Fe  2Cls 

2006-376 

321-545 

Protochloride  of  mercury         • 

2Hg  2C1 

2974-295 

476-666 

Perchloride  of  mercury            • 

Hg2Cl 

1708-472 

273-803 

Ferrocyanide  of  iron    .            • 

Fe  2NC-f  2K  2NC 

2308-778 

370-008 

Alum  .            •            •            . 

KS-1-2A1S3-I-24  2H 

5936-406 

951-378 

Feldspar 

K  Si-f  2A1  Si3 

3542-162 

567-673 

FOUNDING  of  metals,  chiefly  of  Iron.  The  operations  of  an  iron  foundry  consist  iu 
re-melting  the  pig-iron  of  the  blast  furnaces,  and  giving  it  an  endless  variety  of  forms, 
by  casting  it  in  moulds  of  different  kinds,  prepared  in  appropriate  manners.  Coke  is  the 
only  kind  of  fuel  emplcyzd  to  effect  the  fusion  of  the  cast-iron. 

The  essential  parts  of  a  well-mounted  iron  foundry  are, 

1.  Magazines  for  pig-irons  of  d-fferent  qualities,  which  are  to  be  mixed  in  certain  pro- 
portions, for  producing  castings  cf  peculiar  qualities;  as  also  for  coal,  coke,  sands,  clay, 
powdered  charcoal,  and  cow-hair  for  giving  tenacity  to  the  loam  mouldings. 

2.  One  or  more  coke  ovens. 

3.  A  workshop  for  preparing  the  patterns  and  materials  of  the  moulds.  It  should 
contain  small  edge  millstones  for  grinding  and  mixing  the  loam,  and  another  mill  for 
grinding  coa?  ^nd  charcoal. 

4.  A  vast  area,  called  properly  the  foundry,  in  which  the  moulds  are  made  and  filled 
with  the  melted  metal.  These  moulds  are  in  general  very  heavy,  consisting  of  two  parts 
at  least,  which  must  be  separated,  turned  upside  down  several  times,  and  replaced  very 
exactly  upon  one  another.  The  casting  is  generally  effected  by  means  of  large  ladles 
or  pots,  in  which  the  melted  iron  is  transported  from  the  cupola,  where  it  is  fused. 
Hence,  the  foundry  ought  to  be  provided  with  cranes,  having  jibs  moveable  in  every 
direction. 

5.  A  stove  in  which  such  moulds  may  be  readily  introduced  as  require  to  be  entirely 
deprived  of  humidity,  and  where  a  strong  heat  may  be  uniformly  maintained. 

6.  Both  blast  and  air  furnaces,  capable  of  melting  speedily  the  quantity  of  cast-iron  to 
be  employed  each  day. 

7.  A  blowing  machine  to  urge  the  fusion  in  the -furnaces. 

Fig.  650  represents  the  general  plan  of  a  well-mounted  foundry, 
o  is  a  cupola  furnace,  of  which  the  section  and  view  will  be  afterwards  given ;  it  is 
capable  of  containing  5  tons  of  cast-iron, 
d  is  a  similar  furnace,  but  of  smaller  dimensions,  for  bringing  down  If  tons. 
«"  is  a  furnace  like  the  first,  in  reserve  for  great  castings. 


FOUNDING.  go5 

•n^*  nh  *'  ^'  ?  v«stToundry  apartmerit,  whose  floor,  to  a  yard  in  depth,  is  Termed  of  san  * 
and^charcoal  powder,  which  have  already  been  used  for  castings,  and  are  readrfor  hraiC 

mg  up  into  a  substratum,  or  to  be  scooped  out 
when  depth  is  wanted  for  (he  moulds.  There  are 
besides  several  cylindrical  pits,  from  five  to  seven 
yards  m  depth,  placed  near  the  furnaces.  They 
are  lined  with  brick  work,  and  are  usually  left  fuL 
of  moulding  sand.  They  are  emptied  in  order  to 
receive  large  moulds,  care  being  had  that  their  top 
IS  always  below  the  orifice  from  which  the  melted 
metal  is  tapped. 

These  moulds,  and  the  ladles  full  of  melted 
metal,  are  lifted  and  transported  by  the  arm  of  one 
or  more  men,  when  their  weight  is  moderate ;  but 
if  It  be  considerable,  they  are  moved  about  by 
cranes  whose  vertical  shafts  are  placed  at  c,  d,  e, 
m  correspondence,  so  that  they  may  upon  occasion 

^ J       •     .     „      ^  transfer  the  load  from  one  to  another.    Each  crane 

K  composed  principally  of  an  upright  shaft,  embraced  at  top  by  a  collet,  and  tuS 
below  upon  a  pivot  ma  step;  next  of  a  horizontal  beam,  stretched  out  from  nearly  hf 
top  of  ihe  former,  with  an  oblique  stay  running  downwards,  like  that  of  a  gaHows  ^The 

JaTre  tt  we^M^^'rlf-  *  ^""'"*^!'  ""7'"^^^'  *°  ^^'^^^  '^'  '^'^^'  »«  suspended  for 

E«m  Vv  ml   '   r       ^^^''f  '''"■'■f^^  'f  "^^^  ^^  8^^'^*^  backwards  or  forwards  along  the 

wiZ'rlaro7ttVoSl\rir  ^^"^°"  --^-ism,  whose  long  handle  desLds 

By  these  arrangements  in  the  play  of  the  three  cranes,  masses  weighing  five  tons  mav 

kterio"rTf '  t^.  ?h  '  '"^  ^n  ^'^'  ^'^  ^''^'''''  ^'"''''^^  "P^»  «»y  P«i«^  whatever  n  the 
interior  of  the  three  circles  traced  upon  Jig.  650  with  the  points  c,  d,  e,  as  centres 

Ea^4':sh^an\'6  air"^  ^'^^'  ^'^  "^^^^^^^  ^^^^^  «^  '^^  ^»^-  --  -^  -^  turn. 
^^is  the  drying  stove,  having  its  floor  upon  a  level  with  that  of  the  foundry. 
/^,f,  IS  a  supplementary  stove  for  small  articles. 
Si  Sy  ffj  are  the  coking  ovens. 
A,  is  the  blowing  machine  or  fan. 

|ld'.heTa"c"oK,f  """"  '"«  '■'"'' '"«  '»"■"-'?«  ^'"-^ 
t",  are  the  boiler  and  the  furnace  of  the  engine 
k\  workshop  for  preparing  the  loam  and  other  materials  of  moulding. 
/,  is  the  apartment  for  the  patterns. 

.J**^  r  M  r°"'  ^'^^u'  ^'''  ^'^  P^'^^^^  ^'^^^^  "n^e'-  sheds  or  in  the  open  air  round  the 

mm^nt'dtt'hl''  ""^'''t-'  «^««  V«'"'^»»'«  forge,  a  carpenter's  shop,'and  an  Tpanmlnt 
mounted  with  vices  for  ch.pp.ng  and  rough  cleaning  the  castings  by  chisels  and  files 

.n^  '  Mr,i"""^Tr^?  ^^  ^'.^"'"^  "P«"  *  ^"^'•^  s»^^*ce  of  abSut  80  yards  in  each  side 
and  wil   be  capable,  by  casting  in  the  afternoon  and  evening  of  each  day,  piJtly  in  large 

lishm'ent  of"loTnn/'r''  '^  TJ"^  ""'  ^^"°^  '^^  '^  ««^  ^«"«  ^'  annum;  wTth  an  esU^ 
lishment  of  100  operatives,  including  some  moulding  boys.  • 

O/nmkmg  the  moulds.- 1    E^ch  mould  ought  to  present  the  exact  form  of  its  object. 

2.  It  should  have  such  solidity  that  the  melted  metal  may  be  poured  into  it  and  fill 
entirely  without  altering  its  shape  in  any  point.  ^  '  " 

3.  The  air  which  occupies  the  vacant  spaces  in  it,  as  well  as  the  carbureted  eases 

S'Tx^andC  the  he'I'tTnd  ""'''  ^  T'^  ^?/'  ^^^  ''  ^''^^  are\ut  p^rL' I'^conLTd 
iney  expand  b>  the  heat,  and  may  crack,  even  blow  up  the  moulds,  or  at  anv  rate  become 
dispersed  through  the  metal,  making  it  vesicular  and  unsound.  ^ 

Ihere  are  three  distinct  methods  of  making  the  moulds  — 

J .  In  green  sand ;  2.  In  baked  sand ;  3.  In  loam. 

limUs  "oreSl'i  ?o'  ,i,'?'^^^"V'"^\"«  ^°;Pl«yed  to  make  every  sort  of  mould  exceeds  the 
what  isT™  tn«n',h      '"'•  r^  '^'"  merely  indicate  for  each  species  of  moulding, 
Tuch  mou?d^r",il«    Ic^^""    '°",'  '  -^"^  '  '^^"  '^^"  ^^'^''^^  the  fabrication  of  a  few 
M^Sr^yj     most  proper  to  give  general  views  of  this  peculiar  art. 

fromT^^frahv/hTl'^rh  T:^^^  """"^  ?r""  ^'S^^^»  t««  mixture  of  the  sand  as  it  comes 
«1  Tn  iLh  1  '  ^"^^^"to"e  twelfth  its  bulk  of  coal  reduced  to  powder,  and  damp- 

t^P  ohl.r.  •  "'^""^;;«^  t«  ^«™^  PO^o»s  compound,  capable  of  prcsc/vin?  the  forms  <5^ 
nni  pvi.  h'"'^''"'''^  T^"  -''  .  ^^'^  '^"^  °"g^t  to  be  slightly  argillaceous;  with  particks 
hPPn  fi^r.  " -..*  pin's  head  in  size      When  this  mixture  has  once  served  for  a  mould,  anl 

Ltenn  -n""  f^f'^lv  ''""'V^'  '"^P^^^^^  ^^^''^  '^<^'P'  ^^^  the  coarsest  castings;  and 
IS  generally  used  for  filhng  up  the  bottoms  of  fresh  moulds. 

i-or  moulding  any  piece  in  green  sand,  an  exact  pattern  of  the  object  must  be  pre- 


It  lit 


806 


FOUNDING. 


1       ' 

t 

1 

■i  = 

pared  in  wood  or  metal ;  the  latter  being  preferable,  as  not  liable  ^o  warping,  swelling, 

or  shrinkage. 

A  couple  of  iron  frames  form  a  case  or  box,  which  serves  as  an  envelope  to  the  mould. 
Such  boxes  constitute  an  essential  and  very  expensive  part  of  the  furniture  of  a  foundry. 
It  is  a  rectangular  frame,  without  bottom  or  lid,  whose  two  largest  sides  are  united  by  a 
series  of  cross  bars,  parallel  to  each  other,  and  placed  from  6  to  8  inches  apart. 

The  two  halves  of  the  box  carry  ears  corresponding  exactly  with  one  another ;  of 
which  one  set  is  pierced  with  holes,  but  the  other  has  points  which  enter  truly  into  these 
holes,  and  may  be  made  fast  in  them  by  cross  pins  or  wedges,  so  that  the  pair  becomes 
one  solid  body.  Within  this  frame  there  is  abundance  of  room  for  containing  the  pattern 
of  the  piece  to  be  moulded  with  its  incasing  sand,  which  being  rammed  into  the  frame, 
is  retained  by  friction  against  the  lateral  faces  and  cross  bars  of  the  mould. 

When  a  mould  is  to  be  formed,  a  box  of  suitable  dimensions  is  taken  asunder,  and 
each  half,  No.  1  and  No.  2,  is  laid  upon  the  floor  of  the  foundry.  Green  sand  is  thrown 
with  a  shovel  into  No.  1,  so  as  to  fill  it;  when  it  is  gently  pressed  in  with  a  rammer. 
The  object  of  this  operation  is  to  form  a  plain  surface  upon  which  to  lay  in  the  pattern 
with  a  slight  degree  of  pressure,  varying  with  its  shape.  No.  1  being  covered  with  sand, 
the  frame  No.  2  is  laid  upon  it,  so  as  to  form  the  box.  No.  2  being  now  filled  car^ 
fully  with  the  green  sand,  the  box  is  inverted,  so  as  to  place  No.  1  uppermost,  which  is 
then  detached  and  lifted  off  in  a  truly  vertical  position ;  carrying  with  it  the  body  of 
sand  formed  at  the  commencement  of  the  operation.  The  pattern  remains  inribedded  in 
the  sand  of  No.  2,  which  has  been  exactly  moulded  upon  a  great  portion  of  its  surface. 
The  moulder  condenses  the  sand  in  the  parts  nearest  to  the  pattern,  by  sprinkling  a  little 
water  upon  it,  and  trimming  the  ill-shaped  parts  with  small  iron  trowels  of  different 
kinds.  He  then  dusts  a  little  well-dried  finely-sifted  sand  over  all  the  visible  surface  of 
the  pattern,  and  of  the  sand  surrounding  it ;  this  is  done  to  prevent  adhesion  when  he 
replaces  the  frame  No.  1. 

He  next  destroys  the  preparatory  smooth  bed  or  area  formed  in  this  frame,  covers  the 
pattern  with  green  sand,  replaces  the  frame  1  upon  2,  to  reproduce  the  box,  and  proceeds 
to  fill  and  ram  No.  1,  as  he  had  previously  done  No.  2.  The  object  of  this  operation  is 
to  obtain  very  exactly  a  concavity  in  the  frame  No.  1,  having  the  shape  of  the  part 
of  the  model  impressed  coarsely  upon  the  surface  formed  at  the  beginning,  and  which 
was  meant  merely  to  support  the  pattern  and  the  sand  sprinkled  over  it,  till  it  got 
imbedded  in  No.  2. 

The  two  frames  in  their  last  position,  along  with  their  sand,  may  be  compared  to  a  box 
of  which  No.   1  is  the  lid,  and  whose  interior  is  adjusted  exactly  upon  the  enclosed 

Pattern.  .  •     ,v 

If  we  open  this  box,  and  after  taking  out  the  pattern,  close  its  two  halves  again,  then 
pour  in  melted  metal  till  it  fill  every  void  space,  and  become  solid,  we  shall  obviously 
attain  the  wished-for  end,  and  produce  a  piece  of  cast  iron  similar  to  the  pattern.  But 
many  pi-ecautions  must  still  be  taken  before  we  can  hit  this  point.  We  must  first  lead 
through  the  mass  of  sand  in  the  frame  No.  1  one  or  more  channels  for  the  introduction 
of  the  la-slted  metal ;  and  though  one  may  suffice  for  this  purpose,  another  must  be  made 
for  letting  the  air  escape.  The  metal  is  run  in  by  several  orifices  at  once,  when  the 
piece  has  considerable  surface,  but  little  thickness,  so  that  it  may  reach  the  remotest 
points  sufficiently  hot  and  liquid.  ,     . , 

The  parts  of  the  mould  near  the  pattern  must  likewise  be  pierced  with  small  holes,  by 
means  of  wires  traversing  the  whole  body  of  the  sand,  in  order  to  render  the  mould  more 
porous,  and  to  facilitate  the  escape  of  the  air  and  the  gases.  Then,  befor;  liftmg  off 
the  frame  No.  1,  we  must  tap  the  pattern  slightly,  otherwise  the  sand  enclosing  it  would 
stick  to  it  in  several  points,  and  the  operation  would  not  succeed.  These  gentle  jolts 
are  given  by  means  of  one  or  more  pieces  of  iron  wire  which  have  been  screwed  vertically 
into  the  pattern  before  finally  ramming  the  sand  into  the  frame  No.  1,  or  which  enter 
merely  into  holes  in  the  pattern.  These  pieces  are  sufficiently  long  to  pass  out  through 
the  sand  when  the  box  is  filled ;  and  it  is  upon  their  upper  ends  that  the  horizontal 
blows  of  the  hammer  are  given ;  their  force  being  regulated  by  the  weight  and  magni- 
tude of  the  pattern.  These  rods  are  then  removed  by  drawing  them  straight  out ;  after 
which  the  frame  No.  1  may  he  lifted  off  smoothly  from  the  pa"tlern. 

The  pattern  itself  is  taken  out,  by  lifting  it  in  all  its  parts  at  once,  by  means  of  screw 
pins  adjusted  at  the  moment.  This  manoeuvre  is  executed,  for  large  pieces,  almost 
always  by  several  men,  who,  while  they  lift  the  pattern  with  one  hand,  strike  it  with  the 
other  with  small  repeated  blows  to  detach  the  sand  entirely,  in  which  it  is  generally  more 
engaged  than  it  was  in  that  of  the  frame  No.  1.  But  in  spite  of  all  these  precautions, 
there  are  always  some  degradations  in  one  or  other  of  the  two  parts  of  the  mould ;  which 
are  immediately  repaired  by  the  workman  with  damp  sand,  which  he  applies  and  presses 
gently  with  his  trowel,  so  as  to  restore  the  injured  forms.  i  •  j     v 

Hitherto  I  have  supposed  all  the  sand  rammed  into  the  box  to  be  of  one  kmdj  bat 


FOUNDING. 


807 


from  economy,  the  green  sand  is  used  only  to  form  the  portion  of  the  mould  next  the 
pattern,  in  a  stratum  of  about  an  inch  thick ;  the  rest  of  the  surrounding  space  is  filled 
with  the  sand  of  the  floor  which  has  been  used  in  former  castings.  The  interior  layer 
round  the  pattern  is  called,  in  this  case,  new  sand. 

It  may  happen  that  the  pattern  is  too  complex  to  be  taken  out  without  damaging  the 
mould,  by  two  frames  alone ;  then  3  or  more  are  mutually  adjusted  to  form  the  box. 

When  the  mould,  taken  asunder  into  two  or  more  parts,  has  been  properly  repaired,  its 
interior  surface  must  be  dusted  over  with  wood  charcoal  reduced  to  a  very  fine  powder, 
and  tied  up  in  a  small  linen  bag,  which  is  shaken  by  hand.  The  charcoal  is  thus  sifted 
at  the  moment  of  application,  and  sticks  to  the  whole  surface,  which  has  been  previously 
damped  a  little.  It  is  afterwards  polished  with  a  fine  trowel.  Sometimes,  in  order  to 
avoid  using  too  much  charcoal,  the  surfaces  are  finally  dusted  over  with  sand,  very  finely 
pulverized,  from  a  bag  like  the  charcoal.  The  two  frames  are  now  replaced  with  great 
exactness,  made  fast  together  by  the  ears,  with  wedged  bolts  laid  truly  level,  or  at  the 
requisite  slope,  and  loaded  with  considerable  weights.  When  the  casting  is  large,  the 
charcoal  dusting,  as  well  as  that  of  fine  sand,  is  suppressed.  Everything  is  now  ready 
for  the  introduction  of  the  fused  metal.  • 

Moulding  in  baked  or  used  sand. — ^The  mechanical  part  of  th:?  process  is  the  same  as 
of  the  preceding.  But  when  the  castings  are  large,  and  especially  if  they  are  tall,  the 
hydrostatic  pressure  of  the  melted  metal  upon  the  sides  of  the  mould  cannot  be  counter- 
acted by  the  force  of  cohesion  which  the  sand  acquires  by  ramming.  We  must  in  that 
case  adapt  to  each  of  these  frames  a  solid  side,  pierced  with  numerous  small  holes  to  give 
issue  to  the  gases.  This  does  not  form  one  body  with  the  rest  of  the  frame,  but  is  attached 
extemporaneously  to  it  by  bars  and  wedged  bolts.  In  general,  no  ground  coal  is  mixed 
with  this  sand.  Whenever  the  mould  is  finished,  it  is  transferred  to  the  drying  stove, 
where  it  may  remain  from  12  to  24  hours  at  most,  till  it  be  deprived  of  all  its  humidity. 
The  sand  is  then  said  to  be  baked  or  annealed.  The  experienced  moulder  knows  how 
to  mix  the  different  sands  placed  at  his  disposal,  so  that  the  mass  of  the  mould  as  it 
comes  out  of  the  stove  may  preserve  its  form,  and  be  sufficiently  porous.  Such  moulds 
allow  the  gases  to  pass  through  them  much  more  readily  than  those  made  of  green 
sand ;  and  in  general  the  castings  they  turn  out  are  less  vesicular,  and  smoother  upon 
the  surface.  Sometimes  in  a  large  piece,  the  three  kinds  of  moulding,  that  in  green 
sand,  in  baked  sand,  and  in  loam,  are  combined  to  produce  the  best  result. 

Moulding  in  loam. — This  kind  of  work  is  executed  from  drawings  of  the  pieces  to  be 
moulded,  without  being  at  the  expense  of  making  patterns.  The  mould  is  formed  of  a 
pasty  mixture  of  clay,  water,  sand,  and  cow's-hair,  or  other  cheap  filamentous  matter, 
kneaded  together  in  what  is  called  the  loam  mill.  The  proportions  of  the  ingredients  are 
varied  to  suit  the  nature  of  the  casting.  When  the  paste  requires  to  be  made  very  light, 
horse  dung  or  chopped  straw  is  added  to  it. 

I  shall  illustrate  the  mode  of  fabricating  loam  moulds,  by  a  simple  case,  such  as  that 
of  a  sugar  pan.  Fig.  651  is  the  pan.  There  is  laid  upon  the  floor  of  the  foundry  an 
annular  platform  of  cast-iron,  a  by  fig.  652;  and  upon  its  centre  c,  rests  the  lower  extrem- 
ity of  a  vertical  shaft,  adjusted  so  as  to  turn  freely  upon  itself,  while  it  makes  a  wooden 
pattern,  e  /,  fig.  653,  describe  a  surface  of  revolution  identical  with  the  internstl  surface 
reversed  of  the  boiler  intended  to  be  made.  The  outline,  e  g,  of  the  pattern  is  fashioned 
so  as  to  describe  the  surface  of  the^edge  of  the  vessel.  Upon  the  part  a  d  b  dyfig.  652, 
of  th^  flat  cast-iron  ring,  there  must  next  be  constructed,  with  bricks  laid  either  flat  or 
on  their  edge,  and  clay,  a  kind  of  dome,  h  i  k,  fig.  653,  from  two  to  four  inches  thick, 

652 

653 
661 


according  to  the  size  and  weight  of  the  piece  to  be  moulded.  The  external  surface  of 
the  bricif  dome  ought  to  be  everywhere  two  inches  distant,  at  least,  from  the  surface  de- 
scribed by  the  arc  e  /.  Before  building  up  the  dome  to  the  point  t,  coals  are  to  be  placed 
m  its  inside  upon  the  floor,  which  may  be  afterwards  kindled  for  drying  the  mould.  The 
top  is  then  formed,  leaving  at  t,  round  the  upright  shaft  of  revolution,  only  a  very  small 
outlet.  This  aperture,  as  also  some  others  left  under  the  edges  of  the  iron  ring,  enable 
the  moulder  to  light  the  fire  when  it  becomes  necessary,  and  to  graduate  it  so  as  to  make 
it  last  long  enough  without  needing  more  fuel,  till  the  mould  be  quite  finished  and  dry. 
The  combustion  should  be  always  extremely  slow. 
Over  the  brick  dome  a  pasty  layer  of  loam  is  applied,  and  rounded  with  the  mould 


808 


FOUNDING. 


FOUNDING. 


809 


lit  I 


I 


&i    I 


I 


II 


g  «/;  this  surface  is  then  coated  with  a  much  smoother  loam,  by  means  of  the  concave 
edge  of  the  same  mould.  Upon  the  latter  surface,  the  inside  of  the  sugar  pan  is  cast; 
the  line  f  g  having  traced,  in  its  revolution,  a  ledge  m.  The  fire  is  now  kindled,  and  as 
the  surface  of  the  mould  becomes  dry,  it  is  painted  over  by  a  brush,  with  a  mixture  of 
water,  charcoal  powder,  and  a  little  clay,  in  order  to  prevent  adhesion  between  the  sur- 
face already  dried  and  the  coats  of  clay  about  to  be  applied  to  it.  The  board  g  e  /  is 
now  removed,  and  replaced  by  another,  g'  e'  f.  Jig.  654,  whose  edge  «'  f  describes  the 
outer  surface  of  the  pan.  Over  the  surface  e,  /,  a  layer  of  loam  is  applied,  which  is 
turned  and  polished  so  as  to  produce  the  surface  of  revolution  e'  /',  as  was  done  for  the 
surface  ef;  only  in  the  latter  case,  the  line  e'  g'  of  the  board  does  not  form  a  new  shoulder, 
but  rubs  lightly  against  m. 

The  layer  of  loam  included  between  the  two  surfaces  e  /,  t'  fy  is  an  exact  representa- 
tion of  the  sugar  pan.  When  this  layer  is  well  dried  by  the  iieat  of  the  interior  fire,  it 
must  be  painted  like  the  former.  The  upright  shaft  is  now  removed,  leaving  the  small 
vent  hole  through  which  it  passed  to  promote  the  complete  combustion  of  the  coal. 
There  must  be  now  laid  horizontally  upon  the  ears  of  the  platform  d  rf,  jig.  652,  an- 
other annular  platform  p  q,  like  the  former,  but  a  little  larger,  and  without  any  cross-bar. 


654 


The  relative  position  of  these  two  platforms  is  shown  in  fig.  656.  Upon  the  surface 
e'  /',  fig.  655,  a  new  layer  of  loam  is  laid,  two  inches  thick,  of  which  the  surface  is 
smoothed  by  hand.  Then  upon  the  platform  p  g,  fig.  656,  a  brick  vault  is  constructed, 
whose  inner  surface  is  applied  to  the  layer  of  loam.  This  contracts  a  strong  adherence 
■with  the  bricks  which  absorb  a  part  of  its  moisture,  while  the  coat  of  pamt  spread  over 
the  surface  e'  /',  prevents  it  from  slicking  to  the  preceding  layers  of  loam.  The  brick 
dome  ought  to  be  built  solidly. 

The  whole  mass  is  now  to  be  thoroughly  dried  by  the  continuance  of  the  fire,  the 
draught  of  which  is  supported  by  a  small  vent  left  in  the  upper  part  of  the  new  dome  ;  and 
when  all  is  properly  dry,  the  two  iron  platforms  are  adjusted  to  each  other  by  pin  points, 
and  p  q  is  lifted  off,  taking  care  to  keep  it  in  a  horizontal  position.  Upr n  this  platform 
are  removed  the  last  brick  dome,  and  the  layer  of  loam  which  had  been  applied  next  to 
it;  the  latter  of  which  represents  exactly  by  its  inside  the  mould  of  the  surface  «'/',  that 
is,  of  the  outside  of  the  pan.  The  crust  contained  between  e  f  and  e'  f  is  broken  away, 
an  operation  easily  done  without  injury  to  the  surface  e  /,  which  represents  exactly  the 
inner  surface  of  the  pan ;  or  only  to  the  shoulder  w,  corresponding  to  the  edge  of  the 
"vessel.  The  top  aperture  through  which  the  upright  shaft  passed  must  be  now  closed ; 
only  the  one  is  kept  open  in  the  portion  of  the  mould  lifted  off  upon  p  q ;  because  through 
this  opening  the  melted  metal  is  to  be  poured  in  the  process  of  casting.  The  two  plat- 
forms being  replaced  above  each  other  very  exactly,  l^y  means  of  the  adjusting  pin  points, 
the  mould  is  completely  formed,  and  ready  for  the  reception  of  the  metal. 

When  the  object  to  be  moulded  presents  more  complicated  forms  than  the  one  now 
chosen  for  the  sake  of  illustration,  it  is  always  by  analogous  processes  that  the  workman 
construct'  his  loam  moulds,  but  his  sagacity  must  hit  upon  modes  of  executing  many 
things  which  at  first  sight  appear  to  be  scarcely  possible.  Thus,  when  the  forms  of  the 
interior  and  exterior  do  not  permit  the  mould  to  be  separated  in  two  pieces,  it  is  divided 
into  several,  which  are  nicely  fitted  with  adjusting  pins.  More  than  two  cast-iron 
rings  or  platforms  are  sometimes  necessary.  When  ovals  or  angular  surfaces  must  be 
traced  instead  of  those  of  revolution,  no  upright  shaft  is  used,  but  wooden  or  cast-iron 
guides  made  on  purpose,  along  which  the  pattern  cut-out  board  is  slid  according  to  the 
drawing  of  the  piece.  Iron  wires  and  claws  are  often  interspersed  through  the  brick 
work  to  give  it  cohesion.  The  core,  kernel,  or  inner  mould  of  a  hollow  casting  is  fre- 
quently fitted  in  when  the  outer  shell  is  moulded.  I  shall  illustrate  this  matter  in  the 
case  of  a  gas-light  retort, /g.  657.  The  core  of  the  retort  cnght  to  have  the  form  e  «  «  «, 
and  be  very  solid,  since  it  cannot  be  fixed  in  the  outer  mould,  for  the  casting,  except  in 
the  part  standing  out  of  the  retort  towards  m  m.  It  must  be  modelled  in  loam,  upon 
a  piece  of  cast-iron  called  a  lanternj  made  expressly  for  this  purpose.  The  lantern  is  a 
cylinder  or  a  truncated  hollow  cone  of  cast-iron,  about  half  an  inch  thick ;  and  differ- 
ently shaped  for  every  different  core.  The  surface  is  perforated  with  holes  of  about 
half  an  inch  in  diameter.    It  is  mounted  by  meaiiis  of  iron  cross-bars,  upon  an  Iron  axil, 


which  traverses  it  in  the  direction  of  its  length.     Fig.  658  represents  a  horizontal 
section  through  the  axis  of  the  core;  g  h  is  the  axis  of  the  lantern,  figured  itself  »i  i  h 


657 


668 


659 


fc  t ;  o  1 1  0  is  a  kind  of  disc  or  dish,  perpendicular  to  the  axis,  open  at  1 1,  forming  one 
piece  with  the  lantern,  whose  circumference  o  o  presents  a  curve  similar  to  the  section 
of  the  core,  made  at  right  angles  to  its  axis.  We  shall  see  presently  the  two  uses  for 
which  this  dish  is  intended.  The  axis  g  A  is  laid  upon  two  gudgeons,  and  handles  are 
placed  at  each  of  its  extremities,  to  facilitate  the  operation  in  making  the  core.  Upon 
the  whole  surface  of  the  lantern,  from  the  point  h  to  the  collet  formed  by  the  dish,  a  hay 
cord  as  thick  as  the  finger  is  wound.  Even  two  or  more  coils  may  be  applied,  as  occa- 
sion requires,  over  which  loam  is  spread  to  the  exact  form  of  the  core,  by  applying  with 
the  hand  a  board,  against  the  dish  o  o,  with  its  edge  cut  out  to  the  desired  shape ;  as  also 
against  another  dish,  adjusted  at  the  time  towards  A;  while  by  means  of  the  handles  a 
rotatory  movement  is  given  to  the  wh<Jle  apparatus. 

The  hay  interposed  between  the  lantern  and  the  loam,  which  represents  the  crust  of 
the  core,  aids  the  adhesion  of  the  clay  with  the  cast-iron  of  the  lantern,  and  gives  passage 
to  the  holes  in  its  surface,  for  the  air  to  escape,  through  in  the  casting. 

When  the  core  is  finished,  and  has  been  put  into  the  drying  stove,  the  axis  g  ^  is  taken 
out,  then  the  small  opening  which  it  leaves  at  the  point  A,  is  plugged  with  clay.     This  is 
done  by  supporting  the  core  by  the  edges  of  the  dish,  in  a  vertical  position.    It  is  now 
ready  to  be  introduced  into  the  hollow  mould  of  the  piece. 
This  mould  executed  in  baked  sand  consists  of  three  pieces,  two  of  which,  absolutely 

similar,  are  represented,  fig.  659,  at  p  q,  the  third  is 
shown  at  r  s.  The  two  similar  parts  p  q,  present  each 
the  longitudinal  half  of  the  nearly  cylindrical  portion 
of  the  outer  surface  of  the  gas  retort ;  so  that  when 
they  are  brought  together,  the  cylinder  is  formed;  r  « 
contains  in  its  cavity  the  kind  of  hemisphere  which 
forms  the  bottom  of  the  retort.  Hence,  by  adding  this 
part  of  the  mould  to  the  end  of  the  two  others,  the 
resulting  apparatus  presents  in  its  interior,  the  exact 
mould  of  the  outside  of  the  retort ;  an  empty  cylin- 
drical portion  t  /,  whose  axis  is  the  same  as  that  of  the 
cylinder  u  tt,  and  whose  surface,  if  prolonged,  would  be 
everywhere  distant  from  the  surface  tt  tt,  by  a  quan- 
tity equal  to  the  desired  thickness  of  the  retort.  The 
diameter  of  the  cylinder  t  t  is  precisely  equal  to  that  of  the  core,  which  is  slightly  conical, 
in  order  that  it  may  enter  easily  into  this  aperture  t  /,  and  close  it  very  exactly  when  it 
is  introduced  to  the  collet  or  neck. 

The  three  parts  of  the  mould  and  the  core  being  prepared,  the  two  pieces  p  q,  must 
first  be  united,  and  supported  in  an  upright  position  ;  then  the  core  must  be  let  down 
into  the  opening  t  f,  fig.  660.  When  the  plate  or  disc  o  o  of  the  core  is  supported  upon 
the  mould,  we  must  see  that  the  end  of  the  core  is  everywhere  equally  distant  from  the 
edge  of  the  external  surface  u  «,  and  that  it  docs  not  go  too  far  beyond  the  line  q  q. 
Should  there  be  an  inaccuracy,  we  must  correct  it  by  slender  iron  slips  placed  under  the 
edge  of  the  disc  o  o ;  then  by  means  of  a  cast-iron  cross,  and  screw  bolts  v  v,  we  fix  the 
core  immoveably.  The  whole  apparatus  is  now  set  down  upon  r  *,  and  we  fix  with  screw 
bolts  the  plane  surface  q  q  upon  r  r;  then  introduce  the  melted  metal  by  an  aperture  z, 
which  has  been  left  at  the  upper  part  of  the  mould. 

When,  instead  of  the  example  now  selected,  the  core  of  the  piece  to  be  cast  must  go 
beyond  the  mould  of  the  external  surface,  as  is  the  case  with  a  pipe  open  at  each  end, 
the  thing  is  more  simple,  because  we  may  easily  adjust  and  fix  the  core  by  its  two  ends. 
In  casting  a  retort,  the  metal  is  poured  into  the  mould  set  upright.  It  is  important  to 
maintain  this  position  in  the  two  last  examples  of  casting;  for  all  the  foreign  matters 
which  may  soil  the  metal  during  its  flow,  as  the  sand,  the  charcoal,  gases,  scoriae,  being 
less  dense  than  it,  rise  constantly  to  the  surface.  The  hydrostatic  pressure  produced  by 
a  high  gate,  or  filling-in  aperture,  contributes  much  to  secure  the  soundness  and  solidity 
of  the  casting.    This  gate-piece  being  superfluous,  is  knocked  off  almost  immediately 


:■  ! 


I* 


810 


FOUNDING. 


FOUNDING. 


811 


III 


^fler,  or  even  before  the  casting  cools.  Very  long,  somewhat  sle.ider  pieces,  are  usually 
cast  in  moulds  set  up  obliquely  to  the  horizon.  As  the  metal  shrinks  in  cooling,  the 
mould  should  always  be  somewhat  larger  than  the  object  intended  to  be  cast.  The  iron 
founder  reckons  in  general  upon  a  linear  shrinkage  of  a  ninety-sixth  part ;  that  is,  one  eighth 
of  an  inch  per  foot. 

Melting  of  the  cast  iron.  —  The  metal  is  usually  melted  in  a  cupola  furnace,  of  which 
the  dimensions  are  very  various.  Fig.  661  represents  in  plan,  section,  and  elevation, 
one  of  these  furnaces  of  the  largest  size ;  being  capable  of  founding  5  tons  of  cast  iron  at 
a  time.  It  is  kindled  by  laying  a  few  chips  of  wood  upon  its  bottom,  leaving  the  orifice 
c  open,  and  it  is  then  filled  up  to  the  throat  with  coke.  The  fire  is  lit  at  c,  and  in  a 
quarter  or  half  an  hour,  when  the  body  of  fuel  is  sufficiently  kindled,  the  tuyere  blast  is 
set  in  action.  The  flame  issues  then  by  the  mouth  as  well  as  the  orifice  c,  which  has 
been  left  open  on  purpose  to  consolidate  it  by  the  heat.  Without  this  precaution,  the 
sides,  which  are  made  up  in  argillaceous  sand  after  each  day's  work,  would  not  present 
the  necessary  resistance.  A  quarter  of  an  hour  afterwards,  the  orifice  c  is  closed  with  a 
lump  of  moist  clay,  and  sometimes,  when  the  furnace  is  to  contain  a  great  body  of  melted 
metal,  the  clay  is  supported  by  means  of  a  small  plate  of  cast  iron  fixed  against  the 
furnace.  Before  the  blowing  machine  is  set  a  going,  the  openings  g  g  g  had  been  kept 
shut.  Those  of  them  wanted  for  the  tuyeres  are  opened  in  succession,  beginning  at  the 
lowest,  the  tuyeres  being  raised  according  as  the  level  of  the  fused  iron  stands  higher  in 
the  furnace.  The  same  cupola  may  receive  at  a  time  from  one  to  six  tuyeres,  through 
which  the  wind  is  propelled  by  the  centrifugal  action  of  an  eccentric  fan  or  ventilator. 
It  does  not  appear  to  be  ascertained  whether  there  be  any  advantage  in  placing  more 
than  two  tuyeres  facing  each  other  upon  opposite  sides  of  the  furnace.  Their  diameter 
at  the  nozzle  varies  from  3  to  5  inches.  They  are  either  cylindrical  or  slightly  conical. 
A  few  minutes  after  the  tuyeres  have  begun  to  blow,  when  the  coke  sinks  in  the  furnace, 
alternate  charges  of  coke  and  pig  iron  must  be  thrown  in.  The  metal  begins  to  melt  in 
about  20  minutes  after  its  introduction ;  and  successive  charges  are  then  made  every 
10  minutes  nearly ;  each  charge  containing  from  2  cwts.  to  5  cwts.  of  iron,  and  a  quantity 
proportional  to  the  estimate  given  below.  The  amount  of  the  charges  varies  of  course 
with  the  size  of  the  furnace,  and  the  speed  required  for  the  operation.  The  pigs  must 
be  previously  broken  into  pieces  weighing  at  most  14  or  16  pounds.  The  vanes  of  the 
blowing  fan  make  from  625  to  650  turns  per  minute.  The  two  cupolas  represented 
Jig,  661,  and  another  alongside  in  the  plan,  may  easily  melt  6|  tons  of  metal  in  2f  hours; 


that  is,  2|  tons  per  hour.    This  result  is  three  or  four  times  greater  than  what  was 


formerly  obtained  in  similar  cupolas,  when  the  blast  was  thrown  in  from  sn.all  nozzles 
with  cylinder  bellows,  moved  by  a  steam  engine  of  10  horse  power. 

In  the  course  of  a  year,  a  considerable  foundry  like  that  represented  in  the  plan, 
fig.  650,  will  consume  about  300  tons  of  coke  in  melting  1240  tons  of  cast  iron  ;  consisting 
of  940  tons  of  pigs  of  different  qualities,  and  300  tons  of  broken  castings,  gate-pieces, 
&c.  Thus,  it  appears  that  48  pounds  of  coke  are  consumed  for  melting  every  2  cwt. 
of  metal. 

Somewhat  less  coke  is  consumed  when  the  fusion  is  pushed  more  rapidly  to  collect  a 
great  body  of  melted  metal,  for  casting  heavy  articles ;  and  more  is  consumed  when,  as  in 
making  many  small  castings,  the  progress  of  the  founding  has  to  be  slackened  from  time 
to  time  ;  otherwise,  the  metal  would  remain  too  long  in  a  state  of  fusion,  and  probably 
become  too  cold  to  afford  sharp  impressions  of  the  moulds. 

It  sometimes  happens  that  in  the  same  day,  with  the  same  furnace,  pieces  are  to  be 
cast  containing  several  proportions  of  different  kinds  of  iron ;  in  which  case,  to  prevent 
an  intermixture  with  the  preceding  or  following  charges,  a  considerable  bed  of  coke  is 
interposed.  Though  there  be  thus  a  little  waste  of  fuel,  it  is  compensated  by  the 
improved  adaptation  of  the  castings  to  their  specific  objects.  The  founding  generally  begins 
at  about  3  o'clock,  p.  m.,  and  goes  on  till  6  or  8  o'clock.  One  founder,  aided  by  four 
laborers  for  charging,  &c.,  can  manage  two  furnaces. 

The  following  is  the  work  of  a  well-<nanaged  foundry  in  Derby. 

200  lbs.  of  coke  are  requisite  to  melt,  or  bring  down  (in  the  language  of  the  founders), 
1  ton  of  cast-iron,  after  the  cupola  has  been  brought  to  its  proper  heat,  by  the  combustion 
in  it  of  9  baskets  of  coke,  weighing,  by  my  trials,  40  pounds  each,  =  360  lbs. 

The  chief  talent  of  the  founder  consists  in  discovering  the  most  economical  mixtures, 
and  so  compounding  them  as  to  produce  the  desired  properties  in  the  castings.  One 
piece,  for  example,  may  be  required  to  have  great  strength  and  tenacity  to  bear  heavy 
weights  or  strains;  another  must  yield  readily  to  the  chisel  or  the  file;  a  third  must  resist 
sudden  alternations  of  temperature ;  and  a  fourth  must  be  pretty  hard. 

The  filling  in  of  the  melted  metal  is  managed  in  two  ways.  For  strong  pieces,  whose 
moulds  can  be  buried  in  the  ground  at  7  or  8  yards  distance  from  the  furnace,  the  metal 
may  be  run  in  gutters,  formed  in  the  sand  of  the  floor,  sustained  by  plates  or  stones.  The 
clay  plug  is  pierced  with  an  iron  rod,  when  all  is  ready. 

When  from  the  smaller  size,  or  greater  distance  of  the  moulds,  the  melted  metal 
cannot  be  run  along  the  floor  from  the  furnace,  it  is  received  in  cast-iron  pots  or  ladles, 
lined  with  a  coal  of  loam.  These  are  either  carried  by  the  hands  of  two  or  more  men, 
or  transported  by  the  crane.  Between  the  successive  castings,  the  discharge  hole  of  the 
furnace  is  closed  with  a  lump  of  clay,  applied  by  means  of  a  stick,  having  a  small  disc  of 
iron  fixed  at  its  end. 

After  the  metal  is  somewhat  cooled,  the  moulds  are  taken  asunder,  and  the  excres- 
cences upon  the  edges  of  the  castings  are  broken  off  with  a  hammer.  They  are  afterwards 
more  carefully  trimmed  or  chipped  by  a  chisel  when  quite  cold.  The  loss  of  weight  in 
founding  is  about  6^  per  cent,  upon  the  pig  iron  employed.  Each  casting  always  requires 
the  melting  of  considerably  more  than  its  own  weight  of  iron.  This  excess  forms  the 
gates,  false  seams,  &c.  ;  the  whole  of  which  being  deducted,  shows  that  1  cwt.  of  coke 
is  consumed  for  every  3  cwts.  of  iron  put  into  the  furnace ;  for  every  138  cwts.  of  crude 
metal,  there  will  be  100  cwts.  of  castings,  32  of  refuse  pieces,  and  6  of  waste. 

Explanation  of  the  plates. 

Manner  of  constructing  the  Mould  of  a  Sugar-pan. 

Fig.  651.  View  of  the  pan. 

—  652.  Flat  ring  of  cast-iron  for  supporting  the  inner  mould. 

—  653.  Construction  of  the  inner  mould. 

—  654.  Formation  of  the  outer  surface  of  the  pan. 

—  655.   Finished  mould. 

—  956.  Position  of  the  two  flat  cast-iron  rings,  destined  to  sustain  the  moulds  of  the 
inner  and  the  outer  surface. 

Gas-retort  Moulding, 

—  657.  Vertical  projection,  perpendicular  to  the  axis  of  the  retort ;  and  two  sections, 
the  one  upris:ht,  the  other  horizontal. 

—  658.  Construction  of  the  core  of  the  retort. 

—  659.  Disposition  of  the  outer  mould. 

—  660.  Adjustment  of  the  core  in  the  mould. 

—  661.  Cupola  furnace.    It  is  3  feet  wide  within,  and  131  high. 
m  m,  solid  body  of  masonry,  as  a  basis  to  the  furnace. 


T 


812 


FOUNDING. 


b  6,  octagonal  platform  of  cast  iron,  with  a  ledge  in  which  the  plates  a  a  a  a  are  en- 
gaged. 

a  a,  eight  plates  of  cast  iron,  1  inch  thick,  absolutely  similar ;  only  one  of  them  it 
notched  at  its  lower  part  in  c,  to  allow  the  melted  metal  to  run  out,  and  two  of  the  othen 
have  six  apertures  g  g  g,  &c.  to  admit  the  tuyeres. 

c,  orifice  for  letting  the  metal  flow  out.  A  kind  of  cast  iron  gutter,  e,  lined  with  loam, 
is  fitted  to  the  orifice. 

d,  hoops  of  hammered  iron,  4J  inches  broad ;  one  half  of  an  inch  thick  for  the  bottom 
ones,  and  a  quarter  of  an  inch  for  the  upper  ones.  The  intermediate  hoops  decrease  in 
thickness  from  below  upwards  between  these  limits. 

e,  cast  iron  gutter  or  spout,  lined  with  loam,  for  running  off  the  metal. 

//,  cylindrical  piece  of  cast  iron,  for  increasing  the  height  and  draught  of  the 
furnace. 

g,  side  openings  for  receiving  the  tuyeres,  of  which  there  are  six  upon  each  side  of  the 
furnace.  Each  of  them  may  be  shut  at  pleasure,  by  means  of  a  small  cast  iron  plate  h, 
made  to  slide  horizontally  in  grooves  sunk  in  the  main  plate,  pierced  with  the  holes 


es 


k  kf  interior  lining  of  the  surface,  made  of  sand,  somewhat  argillaceous,  in  the  following 

way.  After  having  laid  at 
the  bottom  of  the  furnace  a 
bed  of  sand  a  few  inches  thick, 
slightly  sloped  towards  the 
orifice  of  discharge,  there  is 
set  upright,  in  the  axis  of  the 
cupola,  a  wooden  cylinder  of 
its  whole  height,  and  of  a 
diameter  a  little  less  than  that 
of  the  vacant  space  belonging 
to  the  top  of  the  furnace. 
Sand  is  to  be  then  rammed  in 
so  as  to  fill  the  whole  of  the 
furnace ;  after  which  the 
wooden  cylinder  is  with- 
drawn, and  the  lining  of  sand 
is  cut  or  shaved  away,  till  it  has 
received  the  proper  form. 
This   lining   lasts   generally 

5  or  6  weeks,  when  there  are 

6  meltings  weekly. 
i  I,  cast  iron  circular  plate, 

through  which  the  mouth  of 
the  furnace  passes,  for  protect- 
ing the  lining  in  k  during  the 
introduction  of  the  charges. 

K  K,  level  of  the  floor  of  the 
foundry.  The  portion  of  it 
below  the  running  out  orifice 
consists  of  sand,  so  that  it  may 
be  readily  sunk  when  it  is  wish- 
ed to  receive  the  melted  metal 
in  ladles  or  pots  of  large  di- 
mensions. 

The  fan  distributes  the  blast 
from  the  miiin  pipe  to  three 
principal  p«)ints,  by  three 
branch  tubes  of  distribution. 
A  register,  consisting  of  a 
cast-ircn  plate  sliding  with 
friction  in  z  frame,  serves  to 
intercept  the  blast  at  any  mo- 
iseat,  when  it  is  not  desirable 
to  stop  the  moving  power. 
A  large  main  pipe  of  zinc  or 
sheet  iron  is  fitted  to  the  ori- 
fice of  the  slide  valve.  It  is 
square  at  the  beginning,  ot 
only  rounded  at  the  angles 


!      ',1 


FOUNDINlt. 


813 


but  at  a  little  distance  it  becomes  cylindrical,  and  conducts  the  blast  to  the  divaricating 
points.  There,  each  of  the  branches  turns  up  vertically,  and  terminates  at  bb,  Jig.  662, 
where  it  presents  a  circular  orifice  of  7^  inches.  Upon  each  of  the  upright  pipes  6,  the 
one  end  of  an  elbow-tubeof  zinc  c  c  c  Cy  Jig.  662,  is  adjusted  rather  loosely,  and  the 
other  end  receives  a  tuyere  of  wrought  iron  d  rf,  through  the  intervention  of  a  shiAing 
hose  or  collar  of  leather  c  c  dy  hooped  with  iron  wire  to  Doth  the  tube  and  the  tuyere. 
The  portion  c  c  c  c  may  be  raised  or  lowered,  by  sliding  upon  the  pipe  b,  in  order  to 
bring  the  nozzle  of  the  tuyere  d  dy  to  the  requisite  point  of  the  furnace.  The  portion 
c  c  c  c  may  be  made  also  of  wrought  iron.  A  power  of  4  horses  is  adequate  to  drive  this 
fan,  for  supplying  blast  to  3  furnaces. 

The  founders  have  observed  the  efflux  of  air  was  not  the  same  when  blown  into  the 
atmosphere,  as  it  was  when  blown  into  the  furnaces ;  the  velocity  of  the  fan,  with  the 
same  impulsive  power,  being  considerably  increased  in  the  latter  case.  They  imagine  that 
this  circumstance  arises  from  the  blast  being  sucked  in,  so  to  speak,  by  the  draught  of  the 
furnace,  and  that  the  fan  then  supplied  a  greater  quantity  of  air. 

The  following  experimental  researches  show  the  fallacy  of  this  opinion.  Two  water 
syphons,  c  e  <?,  ///,  made  of  glass  tubes,  one  fifth  of  an  inch  in  the  bore,  were  inserted 
into  the  tuyere,  containing  water  in  the  portions,  gggyhhh.  The  one  of  these  fnino- 
meters  for  measuring  the  pressure  of  the  air  was  inserted  at  fe,  the  other  in  the  centre  of 
the  nozzle.  The  size  of  this  glass  tube  was  loo  small  to  obstruct  in  any  sensible  degree 
the  outlet  of  the  air.  It  was  found  that  when  the  tuyeres  of  the  fan  discharged  into"  the 
open  air,  the  expenditure  by  a  nozzle  of  a  constant  diameter  was  proporiional  to  the 
number  of  the  revolutions  of  the  vanes.  It  was  further  found,  that  when  the  speed  of  the 
vanes  was  constant,  the  expenditure  by  one  or  by  two  nozzles  was  proportional  lo  ihe  total 
area  of  these  nozzles.  The  following  formulae  give  the  volume  of  air  furnished  bv  the 
fan,  when  the  number  of  turns  and  the  area  of  the  nozzles  are  known. 


Volume 
Volume 


25-32  S  n 


1-000,000 
0-86'6'7  S  n 

1,000,000 


(1) 
(2) 


The  volume  is  measured  at  32°  Fahr.,  under  a  pressure  of  29-6  inches  barom. 
S  =  is  the  total  area  of  the  orifices  of  the  tuyeres  in  square  inches, 
n  =  the  number  of  turns  of  the  vanes  in  a  minute. 

After  measuring  the  speed  of  the  vanes  blowing  into  the  atmosphere,  if  we  introduce 
the  nozzle  of  discharge  into  the  orifice  of  the  furnace,  we  shall  find  that  their  speed  im- 
mediately augments  in  a  notable  degree.  We  might,  therefore,  naturally  suppose  that 
the  fan  furnishes  more  air  in  the  second  case  than  in  the  first ;  but  a  little  reflection  will 
show  that  it  is  not  so.  In  fact,  the  air  which  issues  in  a  cold  state  from  the  tuyere 
encounters  instantly  in  the  furnace  a  very  high  temperature,  which  expands  it,  and 
contributes,  along  with  the  solid  matters  with  which  the  furnace  is  filled,  to  diminish 
the  facility  of  the  discharge,  and  consequently  to  retard  the  efflux  by  the  nozzles.  The 
oxygen  gas  consumed  is  replaced  by  a  like  volume  of  carbonic  acid  gas,  equally  expan- 
sible by  heat.  Reason  leads  us  to  conclude  that  less  air  flows  from  the  nozzles  into  the 
furnace  than  into  the  open  atmosphere. 

The  increase  in  the  velocity  of  the  vanes  takes  place  precisely  in  the  same  manner, 
when  after  having  made  the  nozzles  blow  into  the  atmosphere,  we  substitute  for  these 
nozzles  others  of  a  smaller  diameter,  instead  of  directing  the  larger  ones  into  the  furnace. 
Hence  we  may  conceive  that  the  proximity  of  the  charged  furnace  acts  upon  the  blast 
like  the  contraction  of  the  nozzles.  When  the  moving  power  is  uniform,  and  the  velocity 
of  the  vanes  remains  the  same,  the  quantity  of  air  discharged  must  also  be  the  same  in  the 
two  cases. 

Two  tuyeres,  one  5  inches  in  diameter,  the  other  4|,  and  which,  consequently,  pre- 
sented a  total  area  of  35  J  square  inches,  discharged  air  into  one  of  the  furnaces,  from  a 
fan  whose  vanes  performed  654  turns  in  the  minute.  These  two  nozzles  being  briskly 
withdrawn  from  the  furnace,  and  turned  round  to  the  free  air,  while  a  truncated  paste- 
board cone  of  SJ  inches  diameter  was  substituted  for  the  nozzle  of  4|  inches,  whereby 
the  area  of  efflux  was  reduced  to  29-3  square  inches,  the  velocity  of  the  vanes  continued 
exactly  the  same.  The  inverse  operation  having  been  performed,  that  is  to  say,  the  two 
original  nozzles  having  been  smartly  replaced  in  the  furnace,  to  discover  whether  or  not 
the  moving  power  had  changed  in  the  interval  of  the  experiment,  they  betrayed  no  per- 
ceptible alteration  of  speed.  From  the  measures  taken  to  count  the  speed,  the  error 
could  not  exceed  3  revolutions  per  minute,  which  is  altogether  unimportant  upon  tho 
number  654. 


814 


FREEZING. 


It  follows,  therefore,  that  when  the  vanes  of  the  fan  have  the  velocity  of  6o4  turns  p« 
minute,  the  expenditure  by  two  nozzles,  whose  joint  area  is  35^  square  inches,  both 
blowing  into  a  furnace,  is  to  the  expenditure  which  lakes  place  when  the  same  nozzld 
blow  into  the  air,  as  35-5  is  to  29-3 ;  that  is,  a  little  more  than  four  fifths 

If  this  be,  as  is  probable,  a  general  rule  for  areas  and  speeds  considerably  different 
from  the  above,  to  find  the  quantity  of  air  blown  into  one  or  more  furnaces  by  the  fan, 
we  should  calculate  the  volume  by  one  of  the  above  formute  (1)  or  (2),  and  take  four  fiftht 

of  the  result  as  the  true  quantity.  .      «  j  v    »# 

The  fan  a  c  here  represented  is  of  the  best  eccentric  form,  as  constructed  by  Messrs. 
Braithwaite  and  Ericsson.  D  is  the  circular  orifice  round  the  axis  by  ^^'ch  the  air  is 
admitted ;  and  c  c  b  is  the  eccentric  channel  through  which  the  air  is  wafted  towards 

the  main  discharge  pipe  e.  ^  •  i    «    .    „r  ♦!,-  ««,-*i. 

FOUNTAIN  Ta  stream  of  water  rising  up  through  the  superficial  strata  of  the  earth. 

See  Artksian  Wells.  .    .      .i  •  „  „r  u»«   «  «i.. 

FOXING  is  a  term  employed  by  brewers  to  characterize  the  souring  of  beei  .m  thf 

process  of  its  fermentation  or  ripening.  „rn— 

FRANKFORT  BLACK  is  made  by  calcining  vine  branches,  and  the  other  relu8«» 
lees  of  the  vinegar  vats  in  Germany.    They  must  be  previously  washed. 

FREEZING.  (Congelatioiiy  Fr. ;  Gefrierung,  Germ.)  The  three  general  forms,  solid, 
liquid,  and  gaseous,  under  one  or  other  of  which  all  kinds  of  matter  exist,  seem  to  b« 
immediately  referable  to  the  influence  of  heat ;  modifying,  balancing,  or  subduing  the 
attraction  of  cohesion.  Every  solid  may  be  liquefied,  and  every  liquid  may  be  vaporized, 
by  a  certain  infusion  of  caloric,  whether  this  be  regarded  as  a  moving  power  or  an  elas- 
tic  essence.  The  converse  of  this  proposition  is  equally  true ;  for  many  cases,  till  lately 
styled  permanent,  may  be  liquefied,  nay,  even  solidified,  by  diminution  of  their  tempera- 
ture,  either  alone,  or  aided  by  a  condensing  force,  to  bring  their  particles  within  the 
sphere  of  aggregative  attraction.  When  a  solid  is  transformed  into  a  liquid  and  a  liquid 
into  a  gas  or  vapor,  a  quantity  more  or  less  considerable  of  heal  Is  absorbed,  or  becomes 
latent,  to  use  the  term  of  Dr.  Black,  the  celebrated  discoverer  of  this  great  law  of  nature. 
When  the  opposite  transformation  takes  place,  the  heat  absorbed  is  again  em i  ted,  or 
what  was  latent  becomes  sensible  caloric.  Upon  the  first  principle,  or  the  absorption  of 
heat,  are  founded  the  various  artificial  methods  of  producing  cold  and  congelation. 
Tables  exhibiting  a  collective  view  of  all  the  Frigorific  Mixtures  contained  in 

Mr.  Walker's  publication,  1808. 
I.— Table  consisting  of  Frigorific  Mixtures,  composed  of  ice,  with  chemical  salts  and 

Frigorific  Mixtures  with  Ice. 


MIXTURES. 


Thennometer  sinks. 


Degree  of  cold 
produced. 


Snow,  or  pounded  ice 
Muriate  of  soda 


Snow,  or  pounded  ice 
Muriate  of  soda 
Muriate  of  ammonia  - 


-  2  parts 

-  1 

-  5  parts 

-  2 
.  1 


Snow,  or  pounded  ice 
Muriate  of  soda     _  - 
Muriate  of  ammonia 
Nitrate  of  potash - 


24  parts 
10 

5 

5 


Snow,  or  pounded  ice 
Muriate  of  soda 
Nitrate  of  ammonia  - 


12  parts 
5 
5 


0) 

u 

0 


a. 

a 

>» 

a 
« 

S 

o 

u 


to  — 5« 


to—12P 


to— 18» 


to  —  25* 


Snow  -  -  -    3  parts 

Diluted  sulphuric  acid  -    2 


From  -f  32»  to  —  23* 


55 


Snow 
Muriatic  acid 


-  8  parts 

-  6 


From  -f  32«  to  —  27» 


59 


Snow 

Diluted  nitric  acid 

Snow 

Muriate  of  lime 


-  7  parts 

-  4 


From  -f  32?  to  —  30° 


62 


-  4  parts 

-  5 


From  -I-  32°  to  —  iOP 


72 


Snow  -  - 

Cryst.  muriate  of  lime 


2  parts  I       p^^^  -I-  32°  to  —  50° 


82 


Snow 
L_Potash^ 


3  parts 
4 


From  4-  32?  to  —  51° 


83 


FREEZING. 


815 


N.  B. — The  reason  for  the  omissions  in  the  last  column  of  the  preceding  table  is,  the 
thermometer  sinking  in  these  mixtures  to  the  degree  mentioned  in  the  preceding  coliuniu 
and  never  lower,  whatever  may  be  the  temperature  of  the  materials  at  mixing. 

II. — Table,  consisting  of  Frigorific  Mixtures,  having  the  power  of  generating  or  cre- 
ating cold,  without  the  aid  of  ice,  sufficient  for  all  useful  and  philosophical  purposes,  in 
any  part  of  the  world  at  any  season. 

Frigorific  Mixtures  without  Ice. 


MIXTURES. 

Thermometer  sinks. 

Degree  of  cold 
produced. 

Muriate  of  ammonia  -            -    5  parts 
Nitrate  of  potash       -            -    5 
Water           -            -            -  16 

From  -j-  50°  to  -{-  10° 

40» 

Muriate  of  ammonia              -    5  parts 
Nitrate  of  potash       -            -    5 
Sulphate  of  soda        -            -    8 
Water            -            -            -  16 

From  -j-  50°  to  -f-  4° 

46 

Nitrate  of  ammonia  -           -    1  part 
Water            -            -            -     1 

From  +  50°  to  -|-  4° 

46 

Nitrate  of  ammonia  -            -     1  part 
Carbonate  of  soda     -           -    1 
Water            -            -            -     1 

From  -f  50°  to  —  7° 

57         i 

^1 

Sulphate  of  soda        -            -    3  parts 
Diluted  nitric  acid    -            -    2 

From  -{-  50°  to  —  3° 

53*       ; 

Sulphate  of  soda        -           -    6  parts 
Muriate  of  ammonia             -    4 
Nitrate  of  potash       -            -    2 
Diluted  nitric  acid    -            -    4 

From  -f  50°  to  —  10° 

1 
60 

Sulphate  of  soda        -            -    6  parts 
Nitrate  of  ammonia  •            -    5 
Diluted  nitric  acid    -            -    4 

From  -f  50°  to  —  14° 

64 

Phosphate  of  soda      -             -     9  parts 
Diluted  nitric  acid    -            -    4 

From  -j-  50°  to  —  12° 

62 

Phosphate  of  soda     -            -    9  parts 
Nitrate  of  ammonia  -            -    6 
Diluted  nitric  acid     -            -    4 

From  +  50°  to  —  21° 

71 

Sulphate  of  soda        -            -    8  parts 
Muriatic  acid    -        -            -    6 

From  4-  60°  to  0° 

50 

Sulphate  of  soda        -           -    5  parts 
Diluted  sulphuric  acid            -    4 

From  4-  50  to  -f  3°                      47 

N.  B. — If  the  materials  are  mixed  at  a  warmer  temperature  than  that  expressed  in  the 
table,  the  eflfect  will  be  proportionably  greater ;  thus,  if  the  most  powerful  of  these 
mixtures  be  made  when  the  air  is  -|-  85°,  it  will  sink  the  thermometer  to  -j-  2°. 

HI. — ^Table  consisting  of  Frigorific  Mixtures  selected  from  the  foregoing  Tables,  and 
combined  so  as  to  increase  or  extend  cold  to  the  extremest  degrees. 

Combinations  of  Frigorific  Mixtures. 


MIXTURES. 

Thermometer  sinks. 

DegTe»  of  eM 
produced. 

Phosphate  of  soda     -            -    5  parts 
Nitrate  of  ammonia  -            -    3 
Diluted  nitric  acid     -            -    4 

From  0°  to  —  34° 

S4» 

Phosphate  of  soda     -            -    3  parts 
Nitrate  of  ammonia  -            -    2 
Diluted  mixed  acids  -           -    4 

From  —  34°  to  —  60° 

16 

Snow             -            -            •    3  parts 
Diluted  nitric  acid    -           -    2 

From  0°  to  —  46°                        46 

816 


II 


FUEL. 
TABLE  m.—coniinued. 


FUEL. 


817 


IdiXTURES. 

Thermometer  •inks. 

Beg.  of  cold 
produced. 

Snow             ... 
Dilated  sulphuric  acid 
Diluted  nitric  acid 

•    8  parts 
.    3 
-    3 

From  —  l(y*  to  —  66" 

46 

Snow  -         -        -        - 
Diluted  sulphuric  acid  - 

-  1  part 

-  1 

From  —  20®  to  —  60* 

40 

Snow  -        -        -        - 
Muriate  of  lime   - 

•    3  parts 
-    4 

From  -\-  2(P  to  —  48® 

68 

Snow  -        -        -        - 
Muriate  of  lime   - 

-  3  parts 

-  4 

From  4-  10°  to  —  54° 

64 

Snow  -        .        -        - 
1    Muriate  of  lime   - 

-  2  parts 

-  3 

From  —  15°  to  —  68° 

53 

Snow  -        -        -        - 
Cryst.  muriate  of  lime  - 

-  1  part 

-  2 

From  0°  to  —  66° 

66 

Snow  -        -        -        - 
Cryst.  muriate  of  lime  - 

-  1  part 

-  3 

From  —  40°  to       73° 

33 

Snow  -        -        -        - 
Diluted  sulphuric  acid  - 

-  8  parts 

-  10 

From  —  68°  to  —  91° 

23 

^-  B'— The  materials  in  the  first  column  are  to  be  cooled,  previously  to  mixing,  to  the 
temperature  required,  by  mixtures  taken  from  either  of  the  preceding  tables. 

Water  absorbs  1000  degrees  of  heat  in  becoming  vapor;  whence,  if  placed  in  a  saucer 
within  an  exhausted  receiver,  over  a  basin  containing  strong  sulphuric  acid,  it  will  freeze 
by  the  rapid  absorption  of  its  heat  into  the  vapor  so  copiously  formed  under  these  circum- 
stances. 

But  the  most  powerful  means  of  artificial  refrigeration  is  afforded  by  the  evaporation 
of  liquefied  carbonic  acid  gas;  for  the  frozen  carbonic  acid  thus  obtained  has  probably  a 
temperature  100°  under  zero;  so  that  when  a  piece  of  it  is  laid  upon  quicksilver,  it  in- 
stantly congeals  this  metal.  The  more  copious  discussion  of  this  subject  belongs  to 
chemical  science. 

FRENCH  BERRIES;  Berries  of  Avignon. 

FRICTION,  counteraction  of;  see  Lubrication, 

FRIT ;  see  Enamel  and  Glass. 

FUEL  (Combustible,  Fr. ;  Brennstoff,  Germ.) 

Such  combustibles  as  are  used  for  fires  or  furnaces  are  called  fuel,  as  wood,  turf,  pit- 
coal.     These  differ  in  their  nature  and  in  their  power  of  giving  heat. 

I.  Wood,  which  is  divided  into  hard  and  soft.  To  the  former  belong  the  oak,  the 
beech,  the  alder,  the  birch,  and  the  elm  ;  to  the  latter,  the  fir,  the  pine  of  different  sorts, 
the  larch,  the  linden,  the  willow,  and  the  poplar. 

Under  like  dryness  and  weight  different  woods  are  found  to  afford  equal  desrees  of 
heat  in  combustion.  Moisture  diminishes  the  heating  power  in  three  ways  ;  by  diminish- 
ing the  relative  weight  of  the  ligneous  matter,  by  wasting  heat  in  its  evaporation,  and 
by  causing  slow  and  imperfect  combustion.  If  a  piece  of  wood  contain,  for  example,  25 
per  cent,  of  water,  then  it  contains  only  75  per  cent,  of  fuel,  and  the  evaporation  of  that 
water  will  require  ^  part  of  the  weight  of  the  wood.  Hence  the  damp  wood  is  of  less 
value  in  combustion  by  ^  or  2  than  the  dry.  The  quantity  of  moisture  in  newly  felled 
wood  amounts  to  from  20  to  50  per  cent.  ;  birch  contains  30,  oak  35,  beech  and  pine  39, 
t^r'  ^^'  -^^^°^^'^^?  to  their  different  natures,  woods  which  have  been  felled  and 
cleft  for  12  months  contain  still  from  20  to  25  per  cent,  of  water.  There  is  never  less 
than  10  per  cent,  present,  even  when  it  has  been  kept  long  in  a  dry  place,  and  though  it 
be  dried  in  a  strong  heat,  it  will  afterwards  absorb  10  or  12  per  cent,  of  water.  If  it  be 
too  strongly  kiln  dried,  its  heating  powers  are  impaired  by  the  commencement  of  carbon- 
ization, as  if  some  of  its  hydrogen  were  destroyed.  It  may  be  assumed  as  a  mean  of 
many  experimental  results,  that  1  pound  of  artificially  dried  wood  will  heat  35  pounds 
of  water  from  the  freezing  to  the  boiling  point;  and  that  a  pound  of  such  wood  as  con- 
tains from  20  to  25  per  cent,  of  water  will  heat  26  pounds  of  ice-cold  water  to  the  same 
degree.  It  is  better  to  buy  wood  by  measure  than  by  weight,  as  the  bulk  is  very  little 
mcreased  by  moisture.  The  value  of  different  woods  for  fuel  is  inversely  as  their  mois- 
ture, and  this  may  easily  be  ascertained  by  taking  their  shavings,  drying  them  in  a  heat 
of  140°  F.,  and  seeing  how  much  weight  they  lose. 

From  every  combustible  the  heat  is  diffused  either  by  radiation  or  by  direct  commnni- 
eation  to  bodies  in  contact  with  the  flame.  In  a  wood  fire  the  quantity  of  radiating  heat 
IS  to  that  diffused  by  the  air  as  1  to  3 ;  or  it  is  one  fourth  of  the  whole  heating  power 


k3  ^^''''°''^-  ^^«  different  charcoals  afford,  under  equal  weights,  equal  quantities  ot 
hH  in.Tl  ""y/^*^^^°"'  "P^l^  an  average,  that  a  pound  of  dry  charcoal  is  capabkof 
henting  73  pounds  of  water  from  the  freezing  to  the  boiling  point;  but  when  it  has  been 

dalllTJ'""'  'T'^  J?  '^'  ^'l'  ^^^"'^^."•"^  ^*  ^«^«»  10  P^r  <^ent.  of  water,  whichl  p^- 
Ually  decomposed  in  the  combustion  into  carbureted  hydrogen,  which  causes  flwne. 
whereas  pure  dry  charcoal  emits  none.  ^      s    *        *^"  vouaca  uoiuc, 

an^from'h?rS'wL:^^?9'?^\?°°'  '""a  ^^.  ^^'^^s,  Upon  an  average,  from  8  to  9  pounds, 
«  WhTo.  •  iV^  '"^  ^^  P°""if '  *"^  ^^"^^  ^^^  ^^"er  are  best  adapted  to  m^ntain 

rhivlof'thr^hTemitrer"*    ^'^  "'^^^^'^^  ^^^'  ^'-^  ^^--^  fires' constitutes  one 

rimfi'n,f,nt v^'  Jl^  ?"^*i^ •  ""^  ^^t  ''^^'^  *'^  «'"^°st  indefinite,  and  give  out  very  va- 
nous  quantities  of  heat  m  their  combustion.  The  carbon  is  the  heat-giving  constituent, 
and  It  amounts,  in  different  coals,  to  from  75  to  95  per  cent.  One  pou^d  of  go«i  dS 
will  upon  an  average,  heat  60  pounds  of  water  from  the  freez"ngTthe  LlungC^^t 
Small  coal  gives  out  three  fourths  of  the  heat  of  the  lar-er  lumos  The  raSi«?^/hp«i 
emitted  by  burning  pitcoal  is  greater  than  that  by  charcoa?        ^  ^  ^^^ 

tn  fiQ      n  ^fpii/oal.-The  heating  power  of  good  coke  is  to  that  of  pitcoal  as  75 

to  69.     One  pound  of  the  former  will  heat  65  pounds  of  water  from  32°  to  212^    so  that 
Its  power  ,s  equal  to  nine  tenths  of  that  of  wood  charcoal  ' 

V.  Turf  or  peat.— One  pound  of  this  fuel  will  heat  from  25  to  30  pounds  of  water 
erh/;rrticL'\^d  il^'rkd'r  '''"'  '^-^^^^l  "P°"  ^^^  compactness  anrf"eiom  fJ^m 

«.wi^^  following  table  the  fourth  column  contains  the  weight  of  atmospherical  air 
substance.'^'"  ""  '"'^"'''^  ^"'  '^'  '""^^^^^  combustion  of  a  ^und  of  each  paSculS 


Species  of  Rombastible. 


Perfectly  dry  wood 

Wood  in  its  ordinary  state 

Wood  charcoal     - 

Pitcoal     -  -  . 

Coke        -  .  . 

Turf 

Turf  charcoal 

Carbureted  hydrogen  gas  - 

Oil 

Wax 

Tallow 

Alcohol  of  the  shops 


Pounds  of  water 

>vhich  a  pound  can 

heat  from  0°  to  212°. 


leu 


35  00 
26-00 
73-00 
6000 
65-00 
30-00 
64-00 
76-00 

78-00 

52-60 


Pounds  of  boiling 

water  evaporated  by 

1  pound. 


6-36 
4-72 
13-27 
10-90 
11-81 
5-45 
11-63 
13-81 

14-18 

9-56 


Weight  of  atmospheric 

air  at  32°,  to  bam 

1  pound. 


5-96 
4-47 

11-46 
9-26 

11-46 
4-60 
9-86 

14-58 

1500 
11-60 


The  quantity  of  air  stated  in  the  fourth  column  is  the  smallest  possible  reonired  in 

iTh  n^r"'^"'''^'"' ""^  ^^  ^^^"^'y  ^^^«  than  would  be  necessary^!n  p  acS  wte  e 
much  of  the  air  never  comes  into  contact  with  the  burning  body  and  where  h  ^n!^ 
quently  never  has  its  whole  oxygen  consumed.    The  heating  powe'r  seated  rthe  seco-S 

Tne  draught  of  air  usually  carries  off  at  least  1  of  the  heat  and  mnrp  if  iiJ\^ 
ture  be  very  high  when  it  leaves  the  vessel.  ^In  this^  e  It  ^lyTmoim  to  o^^^ 
of  the  whole  heat  or  more,-   without  reckoning  the  loss  by  radiaiiorand  cond"rction 
which,  however,  may  be  rendered  very  small  by  enclosing  the  fire  and  flues  within  nr^' 
per  non-conducting  and  non-radiating  materials  ^ 

It  appears  that,  in  practice,  the  quantity  of  heat  which  may  be  obtained  from  anv  com 

£e"  S'  VS:'JlCT\^''r''''  "^r  ^^^^  -^^^  lhVnaJ^:re  "f  theTl^^^^^ 
heated.     In  heating  chambers  by  stoves,  and  water  boilers  by  furnace^;  the  effluent  heat 

i"uan?itv  rcL'nt'l ''"r  ^/k"'?  V^^  ^ ""^^^  ^^''^  ^-y  be  reduced  to  a  ver^  molrafe 
herth^'ln  hPr^hrJ,rh  /^^'^^/^  ^'^^^'^  ^^^^^  ^^^  ^^^^  constructed  re/erberatory 
to  concert  7^nLlV.nrw^^  °^'*^*'".  ^"^•""^''  ^"^  P^""'^  "^  <^°«^  '«  '^^^^^''^  «^^<l««te 
hP  frpl^InJlT  1-r  '^'^^  ^^J:^'  ^"^^^  ^^P«^'-  «^  to  heat  41f  pounds  of  water  from 
fJZZnf  w,t^  *^''i"^PJi"*-  ^^^  P«""d  of  fir  of  the  usual*dlyness  will  evaporate 
ry^wlnCtt  ''''  *^^^' 22  pounds  to  the  boiling  temperature ;  which  is  about  two 

fhi  tplf    .  T  "  '^T  f  '^'f  combustible.     According  to  Watt's  experiments  up<,a 

^!Jr     L    At'^""^  ^r"^  f  ^°^^  ^^'^  ^'^  ««">  ^ith  the  best  built  boiler,  9  pounds  «1 
water;  the  deficiency  from  the  maximum  effect  being  here  If,  or  nearly  one  skth. 

In  many  cases,  the  hot  air  which  passes  into  the  flues  or  chimneys  may  be  bene- 


Ill 


11 


818 


FULLER'S  EARTH. 


ficially  applied  to  the  heating,  drying,  or  roasting  of  objects ;  but  care  ought  to  be  takeu 
that  the  draught  of  the  fire  be  not  thereby  impaired,  and  an  imperfect  combustion  of  th« 
fuel  produced.  For  at  a  low  smothering  temperature  both  carbonic  oxyde  and  carburet* 
ed  hydrogen  may  be  generated  from  coal,  without  the  production  of  much  heat  in  the 
fire-place. 

To  determine  exactly  the  quantity  of  heat  disengaged  by  any  combustible  in  the  act 
of  burning,  three  different  systems  of  apparatus  have  been  employed :  1.  the  calorimeter 
of  Lavoisier  and  Laplace,  in  which  the  substance  is  burned  in  the  centre  of  a  vessel,  whose 
walls  are  lined  with  ice ;  and  the  amount  of  ice  melted,  measures  the  heat  evolved  ;  2.  the 
calorimeter  of  Watt  and  Rumford,  in  which  the  degree  of  heat  communicated  to  a  given 
body  of  water  affords  the  measure  of  temperature ;  and  3.  by  the  quantity  of  water  evap- 
orated by  different  kinds  of  fuel  in  similar  circumstances. 

If  our  object  be  to  ascertain  the  relative  heating  powers  of  different  kinds  of  fuel,  we 
need  not  care  so  much  about  the  total  wasle  of  heat  in  the  experiments,  provided  it  be 
the  same  in  all ;  and  therefore  they  should  be  burned  in  the  same  furnace,  and  in  the 
nme  way.    But  the  more  economically  the  heat  is  applied,  \Le  greater  certainty  will 

there  be  in  the  results.  The  apparatus ^g.  480, 
is  simple  and  well  adapted  to  make  such  com- 
parative trials  of  fuel.  The  little  furnace  is 
covered  at  top,  and  transmits  its  burned  a'r  by  c, 
through  a  spiral  tube  immersed  in  a  cistern  of 
water,  having  a  thermometer  inserted  near  its 
top,  and  another  near  its  bottom,  into  little  side 
orifices  a  a,  while  the  efiluent  air  escapes  from  the 
upright  end  of  the  tube  b.  Here  also  a  ther- 
mometer bulb  may  be  placed.  The  average  in- 
dication of  the  two  thermometers  gives  the  mean 
temperature  of  the  water.  As  the  water  evapo- 
rates from  the  cistern,  it  is  supplied  from  a  vessel 
placed  alongside  of  it.  The  experiment  should  be 
begun  when  the  furnace  has  acquired  an  equa- 
bility of  temperature.  A  throttle  valve  at  c  serves  to  regulate  the  draught,  and  to 
equalize  it  in  the  different  experiments  by  means  of  the  temperature  of  the  effluent 
air.  When  the  water  has  been  heated  the  given  number  of  degrees,  which  should  be 
the  same  in  the  different  experiments,  the  fire  may  be  extinguished,  the  remaining  fuel 
weighed,  and  compared  with  the  original  quantity.  Care  should  be  taken  to  make  the 
combustion  as  vivid  and  free  from  smoke  as  possible. 

On  the  measurement  of  heat,  and  the  qualities  of  different  kinds  of  coal,  I  made  an 
elaborate  series  of  experiments,  a  few  vears  aso,  of  which  the  following  is  an  outline. 

The  first  and  most  celebrated,  though  probably  not  the  most  accurate  apparatus  for 
measuring  the  quantity  of  heat  transferable  from  a  hotter  to  a  colder  body,  was  the 
calorimeter  of  Lavoisier  and  Laplace.  It  consisted  of  three  concentric  cylinders  of  tin 
plate,  placed  at  certain  distances  asunder ;  the  two  outer  interstitial  spaces  being  filled 
with  ice,  while  the  innermost  cylinder  received  the  hot  body,  the  subject  of  experiment. 
The  quantity  of  water  discharged  from  the  middle  space  by  the  melting  of  the  ice  in  it, 
served  to  measure  the  quantity  of  heat  given  out  by  the  body  in  the  central  cylinder. 
A  simpler  and  better  instrument  on  this  principle  would  be  a  hollow  cylinder  of  ice  of 
proper  thickness,  into  whose  interior  the  hot  body  would  be  introduced,  and  which 
would  indicate  by  the  quantity  of  water  found  melted  within  it  the  quantity  of  heat 
absorbed  by  the  ice.  In  this  case,  the  errors  occasioned  by  the  retention  of  water  among 
the  fragments  of  ice  packed  into  the  cylindric  cell  of  the  tin  calorimeter,  would  be 
avoided.  One  pound  of  water  at  172**  F.,  introduced  into  the  hollow  cylinder  above 
described,  will  melt  exactly  one  pound  of  ice  j  and  one  pound  of  oil  heated  to  172°  will 
melt  half  a  pound. 

The  method  of  refrigeration,  contrived  at  first  by  Meyer,  has  been  in  modem  times 
brought  to  great  perfection  by  Dulong  and  Petit.  It  rests  on  the  principle,  that  two 
surfaces  of  like  size,  and  of  equal  radiating  force,  lose  in  like  times  the  same  quantity 
of  heat  when  they  are  at  the  same  temperature.  Suppose  for  example,  that  a  vessel  of 
polished  silver,  of  small  size,  and  very  thin  in  the  metal,  is  successively  filled  with  dif- 
ferent pulverized  substances,  and  that  it  is  allowed  to  cool  from  the  same  elevation  of 
temperature ;  the  quantities  of  heat  lost  in  the  first  instant  of  cooling  will  be  always 
equal  to  each  other;  aud  if  for  one  of  the  substances,  the  velocity  of  cooling  is  double 
of  that  for  another,  we  may  conclude  that  its  capacity  for  heat  is  one  half,  when  its 
weight  is  the  same  ;  since  by  losing  the  same  quantity  of  heat,  it  sinks  in  temperature 
double  the  number  of  degrees. 

The  method  of  viixtures, — In  this  method,  two  bodies  are  always  employed ;  a  hot 
body  which  becomes  cool,  and  a  cold  body,  which  becomes  hot,  in  such  manner  that  all 


FUEL. 


819 


the  caloric  which  goes  out  of  the  former  is  ( xpended  in  heating  the  latter.  Suppose 
tor  example,  that  we  pour  a  pound  of  quicksilver  at  212°  F.,  into  a  pound  of  wateVlt 

nilrl  ^l"'*^'^^»Iver  will  cool  and  the  water  will  heat,  till  the  mixture  by  stirring  ac 
VZu  u  ^''"^'"O"  temperature.  If  this  temperature  was  122°,  the  wa»er  and  mercury 
mn.i  nftiT!  T^'  capacities,  since  the  same  quantity  of  heat  would  produce  in  an  equiU 
t^e  wa  Pr  rnV^H  ^^^^^^^^^^/^S^   changes  of  temperature,  viz.,  an  elevation  of  9^^ 

o  hive  a MnPrT"'''?  ''?^,\"o'^?  '^^''^^'y-  B'^t  in  realit;,  the  mixture  is  found 
watPr  .. ;„  t^^7^5?,t"^«  o^  «"ly  37r,  showing  that  while  the  mercury  loses  174^°  the 

tTat  the  «  r//v  ">  '  '"""  '"'"'^^T  V"  [^'  ^"'^«  «^^^«"^  32  to  1 ;  whence  it  is  concluded, 
hat  the  c*   ac.ty  of  mercury  ,s  J-  of  that  of  water.     Corrections  must  be  made  for  Si 

ThTfnir.      '  vessel  and  for  the  heat  dissipated  during  the  time  of  the  experiment. 

ford  LrwZ^'l.Lr-^'' •"""''''  ^^""^"'^  ^P^"  '^'  •''^"^^  l>"'^^ipl^  ^«  that  of  Count  Rum- 

for  measu^^^  ZTlll?'^'"'''"TT'  "'''^'  ^^  «^o«^idered  as  an  equally  correct  instrument 

bn  sTn?P  if'..n  i\       •  ^"^u"*^  ^^'^  preceding,  but  one  of  much  more  general  applica- 

the  latent  hit  nff'""''""/''",  ^"''"'^^^  ^^  ^"^^  disengaged  in  combustion,  as  well  um 
ine  latent  heat  of  steam  and  other  vapors.  ,  «  «• 


^•"1^-^    I        III- 


(Scale  about }  inch  to  the  foot.) 


wirlrrfraVe^  rZ^A'dit^.l^^^^^^^  ^'  f^^%  '00  gallons  of 
a  zig-zag  horizontal  flue,  or  flat  p?pe  rfc  ^n^  in.h.c T^  ?*  '°/°"'  different  levels,  by 
in  a  round  pipe  at  c,  whU^hvltlth^^^^  ?"1°'''  deep,  ending  below 

receives  there  into  it  the  top  o?a  Lall  bSj  Jd  ^ur"  a"ef  '  tV.T"  '"''  ^'  ^^  ^""^ 
contains  the  fuel.  It  is  surrounded  at  the  distance  of  one  in. h^  '""^"™°!.t  <^r"cible 
which  is  enclosed  at  the  same  time  hy  the  \u{lTnf*hl  f  ^  ^J  ""  '^^'^^'^  crucible, 
of  stagnant  air  between  the  crucTbls's eJvinl  to  pLventTheTertV^^^'T'  '  ^'-^  '"'^"^ 
.nto  the  atmosphere  round  the  body  of  the  furnace  A  ^^l  .^r  """^  ^^'?^  dissipated 
louble  bellows,  enters  the  ash-pit  of  the  furnace  at*  ontsT  t'S"""^  V''  °^  ^y^^^^^^' 
gentle  blast,  to  carry  on  the  combustion,  kindkd  at  firsr  W  h«ir  '"P^^'^'  ^  ''"^^^  ^"^ 
charcoal.     So  completely  is  the  heat  wh  ch?s  dJ.PnL/i  K^il^u^""  •^'^''^^  °^  '"ed-hot 

by  the  wacer  in  the  bath,  that  tSe  air  dtchargeTrthe^^^^  orffio"'"'^.^  '"^'  "^"^^^ 
«ame  temperature  as  the  atmosphere       '^''"^'^^^^  ^^  ^*^«  t<>P  orifice  g,  has  usually  the 

the  zig-zag  tin  plate  flue,  and  a  rim  o7^;„„fht  Ir™  1^3r",rT''-  J-"^""""* 
Since  the  specific  heat  of  copper  is  to  thaTrf  water" s'm  To  ^nnn.T''""  f  r""^; 
the  vessel  is  equal  to  that  of  8  pounds  of  water  fnrws\,i'^'  "■*  ^'""""^  '""  "^ 
tion  is  made  by  leaving  8  pound'  of  water  ou,  of  the^Mt?  nn^^^^^  "/  exact  eorre.v 
experiment.  """' "''"^  wO,  or  1,000  pounds  used  in  eack 

rn^:^:r^.7''r::r?^^^^^  f^l^  ^;-^>  the  combustion  wa. 

the  top  orifice  of  the  flue  a  variable  quandtvof^h.T    ""^  ^.T"".'  ^^"^^«^^"^d  oflf  at 

When  the  object  is  to  determine  1^12  ^  T^  difficult  to  estimate. 

be  introduced  through  a  tube  kito  the  orifice  i^tL  l  ^^eamand  other  vapors,  they  mat 
elevation  of  temperature  in  the  ^^:r'Jr%7i:^^^  ^^^^^^^^ 


820 


FUEL. 


Ill 


from  the  quantity  of  liquid  discharged  into  a  measure  glass  from  the  bottom  outlet  c 
In  this  case,  the  furnace  is  of  course  removed. 

Tiie  heatin?  power  of  the  fuel  is  measured  by  the  r.ambcr  of  degrees  of  tempei-ature 
which  the  combustion  of  one  pound  of  it,  raises  600  or  1,000  pounds  of  water  in  the 
bath,  the  copper  substance  of  the  vessel  being  taken  into  account.  One  pound  of  dry 
wood  charcoal  by  its  combustion  causes  6,000  pounds  of  water  to  become  20°  hottci. 
For  the  sai^e  of  brevity,  we  shall  call  this  calorific  energy  12,000  unities.  In  like  cii^ 
cumslances,  one  pound  of  Llangennoek  coal  will  yield  by  combustion  11,500  unities  of 
caloric.  One  pound  of  charcoal  after  exposure  to  the  air  gives  out  in  burning  only 
10,500  unities ;  but  when  previously  deprived  of  the  moisture  which  it  so  greedily  im- 
bibes from  the  atmosphere,  it  aflords  the  above  quantity.  One  pound  of  Lambton's 
Wall's-end  coals,  aflords  8,500  unities;  and  one  of  anthracite  11,000. 

It  must  be  borne  in  mind  that  a  coal  which  gives  ofl"  much  unburnt  carburetted  hy- 
drogen gas,  does  not  afibrd  so  much  heat,  since  in  the  production  of  the  gas  a  great 
deal  of  heat  is  carried  off  in  the  latent  state.  I  have  no  doubt,  that  by  this  distillatory 
process,  from  one  third  to  one  fourth  of  the  total  calorific  efl'ect  of  many  coals  is  dissi- 
pated in  the  air.  But  by  means  of  such  a  furnace  as  the  patent  Argand  invention  of 
Mr.  C.  W.  Williams,  the  whole  heat  produceable  by  the  hydrogen  as  well  as  the  carbon 
is  obtained ;  and  it  should  be  borne  in  mind  that  a  pound  of  hydrogen  in  burning  gener- 
ates as  much  heat  as  three  pounds  of  carbon. 

Mr.  Berthier  proposes  to  determine  the  proportion  of  carbon  in  coals  and  other  kinds 
of  fuel,  by  igniting  in  a  crucible  a  mixture  of  the  carbonaceous  matter  with  litharge, 
both  finely  comminuted,  and  observing  the  quantity  of  lead  which  is  reduced.  Foi 
every  34  parts  of  lead,  he  estimates  1  part  of  carbon,  apparently  on  the  principle,  thai 
when  carbon  is  ignited  in  contact  with  abundance  of  litharge,  it  is  converted  into  car- 
bonic acid.  Each  atom  of  the  carbon  is  therefore  supposed  to  seize  two  atoms  of 
oxygen,  for  which  it  must  decompose  two  atoms  of  litharge,  and  revive  two  atoms  of 
lesui.     Calling  the  atom  of  carbon  6,  and  that  of  lead  104,  we  shall  have  the  following 

ratio : — 6  :  104X2  : :  1  :  34.66,  being  Berthier's  proportion,  very  nearly. 

On  subjecting  this  theory  to  the  touchstone  of  experiment,  I  have  found  it  to  be  en 
tirely  fallacious.  Having  mixed  very  intimately  10  grains  of  recently  calcined  char- 
coal with  1,000  grains  of  litharge,  both  in  fine  powder,  I  placed  the  mixture  in  a  crucible 
which  was  so  carefully  covered,  as  to  be  protected  from  all  fuliginous  fumes,  and  ex- 
posed it  to  distinct  ignition.  No  less  than  603  grains  of  lead  were  obtained ;  whereas 
by  Berthier's  rule,  only  340  or  346.6  were  possible.  On  igniting  a  mixture  of  10  grains 
of  pulverized  anthracite  from  Merthyr  Tydfil,  with  500  grains  of  pure  litharge  (pre- 
viously fused  and  pulverized),  I  obtained  380  grains  of  metallic  lead.  In  a  second 
similar  experiment  with  the  same  anthracite  and  fttharge,  I  obtained  450  grains  of  lead ; 
and  in  a  third  only  350  grains.  It  is  therefore  obvious  that  this  method  of  Berthier  is 
altogether  nugatory'  for  ascertaining  the  quantity  of  carbon  in  coals,  and  is  worse  than 
useless  forjudging  of  the  calorific  qualities  of  difierent  kinds  of  fuel. 

In  my  researches  upon  coals,  I. have  also  made  it  one  of  my  principal  objects  to  de- 
termine the  quantity  of  sulphur  which  they  may  contain ;  a  point  which  has  been 
hitherto  very  little  investigated  in  this  country  at  least,  but  which  is  of  great  conse- 
quence, not  only  in  reference  to  their  domestic  combustion,  but  to  their  employment 
by  manufacturers  of  iron  and  gas.  That  good  iron  can  not  be  produced  with  a  sul- 
phureous coal,  however  well  coked,  has  been  proved  in  France  by  a  very  costly  experi- 
ence. The  presence  of  a  notable  proportion  of  sulphur  in  a  gas  coal  is  most  injurious 
to  the  gaseous  products,  because  so  much  sulphuretted  hydrogen  is  generated  as  to  re- 
quire an  operose  process  of  washing  or  purification,  which  improverishes  the  gas,  and 
impairs  its  illuminating  powers  by  the  abstraction  of  its  olefiant  gas,  or  bicarburetted 
hydrogen.  In  proof  of  this  proposition,  I  have  only  to  state  the  fact,  that  I  found  in 
a  specimen  of  coal  gas  as  delivered  from  the  retorts  of  one  of  the  metropolitan  compa- 
nies, no  less  than  18  per  cent,  of  olefiant  gas,  while  in  the  same  gas,  after  being  passed 
through  the  purifiers,  there  remained  only  1 1  per  cent,  of  that  richly-illuminating  gas. 
By  using  a  gas-coal,  nearly  free  from  sulphur,  such  as  No.  4,  in  the  subjoined  list,  I 
think  it  probable  that  10  per  cent,  of  more  light  may  be  realized  than  with  the  common 
more  sulphureous  coal.  This  is  an  important  circumstance  which  the  directors  of  gas- 
works have  hitherto  neglected  to  investigate  with  analytical  precision,  though  it  is  one 
upon  which  their  success  and  profits  mainly  depend. 

How  little  attention  indeed  has  been  bestowed  upon  the  sulphureous  impregnation 
of  pit-coal  may  be  inferred  from  the  fact  that  one  of  our  professional  chemists  of  note, 
in  a  public  report,  upon  a  great  commercial  enterprise,  stated  that  a  certain  coal  analyzed 
by  him  was  free  from  sulphur,  which  coal  I  found  by  infallible  chemical  evidence  to 
contain  no  less  than  7  per  cent,  of  sulphur,  being  about  the  double  of  what  is  contained 
in  English  coals  of  average  quality.  The  proportion  of  sulphur  may  in  general  be  in- 
ferred from  the  appearance  and  quantity  of  the  ashes.  If  these  be  of  a  red  or  ochrey 
color,  and  amount  to  above  10  per  cent.,  we  may  be  sure  that  the  coal  is  eminently 


> 


FUEL, 


821 


snlphureous.  The  coal  above  referred  to  afforded  from  15  to  16  per  cent,  of  ferrugin- 
ous ashes.  I  believe  that  sulphur  exists  in  coal  generally,  though  not  always  in  the  state 
01  pyrites,  either  in  manifest  particles,  or  invisibly  disseminated  through  their  substance. 
The  readiest  method  of  determining  rigidly  the  quantity  of  sulphur  in  anv  compound, 
is  to  mix  a  given  weight  of  it  with  a  proper  weight  of  carbonate  of  potassa,  nitre,  and 
common  salt,  each  chemically  pure,  and  to  ignite  the  mixture  in  a  platinum  crucible. 
A  whitish  mass  is  obtained,  in  which  all  the  sulphur  has  been  converted  into  sulphate 
01  potassa.  By  determining  with  nitrate  of  baryta  the  amount  of  sulphuric  acid  pro- 
duced, that  of  the  sulphur  becomes  known.  By  means  of  this  process  applied  to  dif- 
ferent samples  of  coals,  I  obtained  the  following  results  :~ 


Gas 

Ci>ais. 

No.  1 

2 

3 

4 


Sulphur  in 
100  parts. 

3-00 

3-90 

2-42 

3-80 


Gas 

Coals. 

No.  5 

6 

7 

8 


Sulphur  in 
100  parts. 

2-50 

5-20 

3-40 

3-50 


Coals  for  puddling  cast  iron, 
to  be  converted  into  steel, 

No.  1,  hard  foliated  or  splent  coal,  specific  gravity 

2,  ditto 

3,  ditto  -------. 

4,  cubical  and  rather  soft        -        -        -        _ 


1-258 
1-290 
1-273 
1-267 


Sulphur  ia 
100  parts. 
0-80 
0-96 
3-10 
0-80 


1-57 

4-82 
3-25 
10-5 


Tht  lasv  coal  being  rich  in  bitumen,  would  prove  an  excellent  one  for  the  production 
ofa  pure  coal  gas.     See  Pitcoal. 

FUEL,  ECONOMY  OF.  In  the  report  of  the  Transactions  of  the  Institution  of 
Civil  Engineers  for  February,  1838,  the  results  of  exact  comparisons  between  the  per- 
lormance  of  difierent  steam-engines  exhibit  this  economy  in  a  remarkable  manner  It 
la  there  shown  that  a  condensing  engine  of  the  most  perfect  construction,  and  in  peifect 
condition,  of  the  common  low  pressure  crank-kind,  not  working  expansively,  performs 
a  duty  of  not  more  than  20  or  21  millions  of  lbs.  raised  one  foot  high,  by  90  or  94  lbs 
of  coal ;  or  ten  lbs.  of  coal  per  horse  power  per  head. 

The  following  table  exhibits  the  relative  value  of  diflTerent  engines  in  lbs.  of  coalner 
horse  power  per  hour  : —  01*/^* 

Cornish  Pumping  Engine      -        -       -        -       _ 

Bolton  and  Watt's  Single  Engine  -        -        -        - 

Cornish  Double  Engine         ..... 

Bolton  and  Watt's  Double  Engine 

The  greatest  duty  performed  by  the  measured  bushel  of  84  lbs.  was  86|  millions  of 

lbs.     There  was  raised  by  the  Huel  Towan  engine  in  Cornwall  1,085  tons  (of  waters 

one  foot  high  for  one  farthing.     Hence  the  weight  of  a  man  (l^  cwt.)  would  be  raised 

ten  miles  for  one  penny !  v  -«         /  «iacu 

In  order  to  raise  steam  with  economy,  the  surface  of  water  in  the  boiler,  exposed  to 
the  fare,  ought  not  to  be  less  thon  10  square  feet  per  horse  power ;  but  the  usual  allow- 
ance in  Lancashire  is  only  7^;  and  by  Messrs.  Boulton  and  Watt,  5  square  feet 

The  values  of  the  mean  of  the  Cornish,  Warwick,  London,  Lancashire,  and  loco- 
motive experiments,  as  reported  by  Mr.  Josiah  Parkes,  were  respectively  21    18    13i 
and^K)  cubic  feet  of  water  evaporated  by   112  lbs.  of  coals,  from  water  heat'ed  to 

FUEL    GRANT'S  PATENT       This  fuel  is  composed  of  coal-dust  and   coal-tar 
pitch ;  these  materials  are  mixed  together,  under  the  influence  of  heat,  in  the  following 
Rrop<,rtions  :-20  lbs.  of  pitch    to   1   cwt.  of  coal-dust,   by   appropriate   machinery^ 
consisting  of  crushing-rollers  for  breaking  the  coal  in  the  first  instance  sufiiciently 
small,  so  that  it  may  pass  through  a  screen  the  meshes  of  which  do  not  exceed  a  quarter 
oLo"  '.''u     f  ""^^'•5  2dly,  of  mixing-pans  or  cylinders,  heated  to  the  temperature  of 
220  ,  either  by  steam  or  heated  air;  and,  3dly,  of  moulding  machines,  by  which  the 
fuel  IS  compressed,  under  a  pressure  equal  to  five  tons,  into  the  size  of  a  common  biick . 
the  fuel  bricks  are  then  whitewashed,  which  prevents  their  stickin?  together,  either  ir 
the  coal  bunkers  or  ,n  hot  climates.     The  advantages  of  Grant's  fuel  over  even  the 
best  coal  may  be  stated  to  consist,  first,  in  its  superior  efficacy  in  generating  steam, 
which  may  be  thus  stated— 200  tons  of  this  fuel  will  perform  the  same  work  as  30l 
tins  of  coal,  such  as  are  generally  used  ;  secondly,  it  occupies  less  space;  that  is  to  say, 
500  tons  of  It  may  be  stowed  in  an  area  which  will  contain  only  400  tons  of  coal; 
thirdly,  it  is  used  with  much  greater  ease  by  the  stokers  or  firemen  than  coal,  and  it 
creates  little  or  no  dirt  or  dust,  considerations  of  some  importance  when  the  delicate 
machinery  of  a  steam-engine  is  considered;  fourthly,  it  produces  a  very  small  propor 
tion  of  clinkers,  and  thus  it  is  far  less  liable  to  choke  and  destroy  the  furnace  bars  and 


822 


FUEL. 


« 


J- 


II 


bcHlers  than  coal ;  fifthly,  the  ignition  is  so  complete  that  comparatively  little  smoke,  and 
only  a  small  quantity  of  ashes,  are  produced  by  it ;  sixthly,  from  the  mixture  of  the  patent 
fuel,  and  the  manner  of  its  manufacture,  it  is  not  liable  to  enter  into  spontaneous  ignition. 
Fuel  chiefly  Pit  Coal.  "  Considering  the  vast  importance  of  the  subject,  it  is 
somewhat  remarkable  that  no  exact  mode  of  determining  the  true  value  of  coal  as  a  fuel 
has  ever  yet  been  invented.  Of  the  methods  hitherto  in  use  there  is  not  one  which 
deserves  the  title  even  of  an  approximation  to  the  truth.  The  plan  of  Berthier,  as  has 
been  well  shown  by  Dr.  Ure,  is  beyond  all  things  fallacious,  though  this  very  plan  is  that 
most  relied  on  by  the  experimenters  connected  with  the  late  Admiralty  investigation  re- 
specting the  coals  best  suited  for  the  steam  navy.  It  needs,  however,  but  a  moment'9 
reflection  to  see  that  this  process  of  Berthier  can  never  afford  a  correct  result,  for  the  agent 
employed  is  litharge,  a  substance  not  acted  on  at  all  until  exposed  to  heat  more  than 
auflScient  for  the  expulsion  of  the  volatile  constituents  of  coal,  and  moreover  a  substance 
capable  of  being  reduced  at  high  temperatures  by  the  carbonic  oxide  gas  of  the  fire 
employed  to  eflFect  the  assay.  Here  then  are  two  enormous  sources  of  error  ;  for  in  the 
first  place  the  hydrogenous  constituents  of  the  coal  can  never  be  estimated  at  all,  and  in 
the  second  the  litharge  by  mere  exposure  in  a  crucible  to  the  action  of  the  fire  will  give 
metallic  lead  exactly  the  same  as  if  coal  existed  in  it,  so  that  not  the  least  dependence  in 
the  world  can  be  placed  in  this  method.  Numerous  and  carefully  conducted  experiments 
have  fully  confirmed  the  original  observations  of  Dr.  Ure  upon  this  matter,  and,  in  fact, 
the  results  from  four  crucibles,  each  charged  with  the  same  quantities  of  coal  and  litharge, 
taken  from  the  same  massive  powder,  and  placed  side  by  side  in  the  same  furnace,  and 
treated  in  all  respects  exactly  alike,  have  shown  a  discordance  equal  to  the  numbers 
117,  142,  166,  and  163.  To  think  of  attaching  any  value  to  any  of  these,  or  to  the 
average  which  they  present,  is  to  lose  sight  of  the  most  important  province  of  chemistry 
in  its  relation  to  the  arts. 

"  Another,  and  certainly  a  preferable  method,  is  to  consume  a  given  amount  of  each 
coal  in  a  calorimeter,  so  as  to  measure  the  total  heat  disengaged  during  combustion. 
But  here,  again,  we  meet  with  diflficulties  more  than  enough  to  destroy  all  confidence  in 
the  results.  Thus  it  is  not  possible  thoroughly  to  consume  the  whole  of  the  fuel  in  thia 
way.  Of  the  volatile  constituents  of  the  coal,  a  portion  always  passes  off  unbumt  in  the 
shape  of  carburetted  hydrogen,  tar,  and  soot,  whilst  of  the  carbou  or  fixed  constituents, 
part  is  constantly  lost  in  the  form  of  carbonic  oxide  gas.  So  that  no  real  estimate 
of  the  calorific  value  of  a  coal  can  be  arrived  at  in  this  way,  and  even  comparative 
experiments  are  worthless  from  the  great  inequalities  which  prevail  in  the  ratio 
of  the  volatile  and  fixed  ingredients  in  different  coals,  as  well  as  from  the  changes 
induced  by  accidental  variations  of  draught  through  the.  body  of  the  fuel  Of  course 
the  same  objections  apply  to  what  are  called  practical  experiments,  conducted  with  any 
one  particular  form  of  furnace  or  setting  of  a  boiler.  The  form  of  furnace,  as  is  well 
known,  requires  to  be  adapted  to  the  fuel,  and  not  the  fuel  to  the  furnace :  nevertheless, 
m  the  Admiralty  experiments  already  alluded  to,  the  only  f»rm  of  furnace  and  boiler 
employed  was  that  called  the  Cornish  setting,  though  this  particular  form  was  expressly 
invented  for,  and  will,  as  is  notorious,  do  justice  to  no  other  kind  of  coal  than  anthracite. 
Hence  the  parliamentary  reports  which  chronicles  the  results  of  the  Procrustean  theorem, 
though  yet  almost  wet  from  the  press,  is  even  now  rapidly  on  its  road  to  the  butter- 
shop,  there  to  expiate,  by  the  humblest  of  services,  its  previous  utter  inutility  to  the 
public.  To  know  the  precise  amount  of  heat  evolved  from  coals  during  their  com- 
bustion, must,  as  has  been  before  remarked,  be  a  subject  of  the  greatest  possible 
interest,  for  until  the  total  calorific  power  be  taken  into  account,  it  is  impossible  for  ua 
to  appreciate  the  loss  which  ensues  under  the  existing  modes  of  consuming  fuel  At 
present  it  seems  generally  agreed,  that  ordinary  Newcastle  coal  will  evaporate  about 
8  times  Its  weight  of  water,  or  in  other  words,  that  a  ton  of  such  coal  will  boil  off  or  con 
vert  into  steam  17,920  lbs.  of  water.  If,  however,  we  proceed  to  a  practical  analysis  of 
this  very  coal,  by  examining  the  heating  power  of  its  gaseous  and  fixed  constituents 
after  these  have  been  separated  from  each  other,  we  shall  find  that  the  above  is  very  fai 
short  of  the  most  moderate  estimate  that  can  be  formed  of  the  heat  which  must  be  dis- 
engaged ;  and  whether  the  difference  be  lost  by  imperfect  combustion,  or  by  the  action 
of  the  chimney,  or  in  what  other  way,  remains  stQl  to  be  decided  by  those  who  seek  to 
improve  our  present  modes  of  consuming  fuel.  The  following  table  represents  the  actual 
heat  evolved,  and  of  water  evaporated,  by  the  different  constituents  of  one  ton  of  the 
Newcastle  coal  called  Pelton ;  and  it  must  be  remembered,  that  so  far  as  chemical 
research  has  yet  gone,  the  heat  evolved  from  a  combustible  is  in  proportion  to  the 
amount  of  oxygen  consumed,  and  has  no  connection  with  the  particular  mechanical  state 
of  the  combustible.  For  instance,  there  is  no  reason  to  supposie  that  gaseous  carbon, 
if  we  possessed  such  a  substance,  would  evolve  either  more  or  less  heat  than  its 
Muivalent  weight  of  solid  carbou,  in  combining  with  the  same  quantity  of  o.xygen  gas. 
Whether,  therefore,  we  regard  the  constituents  of  coal  as  existing  in  the  solid  or  gaseous 


I 


. 


FUEL. 


823 


form,  does  not,  according  to  our  present  knowledge,  alter  the  proportion  of  heat  which 
these  constituents  would  give  out  during  their  perfect  oxidatioa  Now  one  ton  of 
Pelton  coal  affords 

10,000  cubic  feet  of  gaseous  matters, 
10  gallons  or  about  126  lbs.  of  tar, 
and  41  bushels  or  1680  lbs.  of  coke ; 
and,  by  experiment,  it  has  been  found  that  the  above  gas  before  purification  will  boil  oflf 
for  every  cubw  foot  consumed  10^  ounces  of  water ;  that  3  gallons  of  tar  are  equal  to 
about  one  bushel  of  coke ;  and  that  the  coke  will  boil  off  10  times  its  weight  of  water 
Hence  we  have  the  total  amount  of  water  evaporated  as  under : 

10,000  cubic  feet  of  gas  at  10^  ounces  per  foot  =  6537  lbs. 
10  gallons  of  tar  equal  to  333  bushels  of  coke  =  1365  lbs. 
1680  lbs.  of  coke  at  10  lbs.  per  lb.         -         -    =  16800  lbs. 


Total  24702 
or  upwards  of  1 1  lbs.  of  water  for  every  lb.  of  coal.  It  happens,  however,  that  even  thia 
estimate  is  too  low,  and  that  actual  experiments  on  this  very  coal  shows  its  true  heating 
power  to  be  not  less  than  12.  To  elucidate  this  it  becomes  necessary,  however,  to  enter 
into  an  explanation  of  the  means  employed  for  ascertaining  the  precise  amount  of  heat 
evolved  by  any  combustible  during  its  complete  oxidation,  and  which  is  perhaps  the  only 
approach  to  accuracy  that  has  yet  been  proposed  with  this  view.  A  copper  vessel, 
shaped  like  a  parallelogram,  and  having  in  its  ends  two  small  openings  provided 
with  stop  cocks,  has  also  in  its  lower  surface  a  large  opening  of  two  inches  in  diameter, 
terminating  in  a  tube  or  neck  of  about  two  inches  in  length  and  fitted  with  an  earthen- 
ware plug  or  stopper.  This  parallelogram  is  enclosed  in  another  and  larger  one  capable 
of  holding  m  addition  20  lbs.  of  water.  The  smaller  vessel  should  have  an  internal 
capacity  of  about  half  a  cubic  foot,  or  800  cubic  inches,  and  the  different  openings  must 
pass  out  of  and  through  the  larger  vessel.  The  earthenware  stopper  is  to  be  provided 
with  two  small  openings,  in  which  pass  two  insulated  copper  wires,  and  on  the  top  of  the 
stopper  IS  a  cavity  capable  of  holding  50  grains  of  coal  in  coarse  powder,  throu«-h  which 
a  fine  platinum  wire  passes  connected  with  the  terminal  ends  of  the  two  aipper  wires, 
and  over  the  whole  a  cage  of  stout  platinum  wire  is  placed  so  as  to  prevent  the  coal  from 
being  thrown  out  during  the  experiment,  and  also  to  insure  the  complete  combustion  of 
all  the  volatile  and  fuliginous  matter.  To  use  this  apparatus,  60  grains  of  the  coal  in 
quejition  are  placed  in  the  cavity  of  the  stopper,  and  the  necessary  connections  beinxr 
made  by  means  of  a  fine  platmum  wire,  the  cage  is  applied,  and  the  whole  inserted  in 
tlie  neck  or  opening  left  for  it,  and  which  it  hermetically  closes :  as  soon  as  this  is  com- 
pleted, a  current  of  oxygen  gas  is  made  to  traverse  the  smaller  vessel  by  means  of  the 
stop-cocks  in  the  sides,  and  this  is  continued  until  the  atmospheric  air  bein"-  almost 
wlioUy  expelled,  the  vessel  remains  full  of  oxygen  gas  ;  when  this  is  the  case  water  must 
be  poured  into  the  larger  vessel,  and  a  piece  of  ice  introduced  into  it  until  the  tempera- 
ture has  fallen  about  6°  below  that  of  the  apartment,  when  the  ice  must  be  withdrawn 
and  the  coal  lighted  by  means  of  a  small  galvanic  battery,  the  poles  of  which  need  be 
applied  but  for  a  moment  to  the  copper  wires  which  pass  through  the  earthenware 
stopper.  Ignition  instantly  ensues,  and  is  finished  in  two  or  three  seconds,  when  the  heat 
of  the  water  in  the  larger  vessel  must  be  ascertained  by  a  delicate  thermometer  after 
proper  agitation.  It  is  of  course  necessary  to  take  the  usual  precautions  followed  in 
experiments  of  this  kind,  and  to  surround  the  whole  of  the  larger  vessel  by  non-con- 
ductors of  caloric,  having  carefully  determined  beforehand  the  absorption  of  heat  due  to 
the  apparatus,  so  that  this  may  be  added  to  that  of  the  water  •  the  water  itself  should 
either  be  actually  weighed  or  measured  with  great  accuracy  at  a  mean  temperature  and 
the  ice  must  also  be  weighed  before  and  after  immersion.  The  accompanying  sketch  in 
section  will  perhaps  facilitate  the  comprehension  of  this  instrument        ^     -^    ^ 

*A,  cover  made  of  wood;  b,  lai^er 
vessel  of  copper;  c,  smaller  vessel  of 
copper ;  d,  entrance  for  oxygen  gas ; 
K,  exit  for  atmospheric  air^  f,  plati- 
num cage  ;  g,  earthenware  stopper 
with  cavity  in  top;  h  h,  copper  wires 
for  conveying  electricity,  between  the 
upper  extremities  of  which  a  fine  pla- 
tinum wire  is  loosely  stretched  which 
passes  through  the  mass  of  powdered 
coal. 

The  results  hitherto  obtained  by 
this  apparatus  are  not  very  extensive, 
but    nevertheless    they    embrace    sub- 


■ 


824 


FUEL. 


stantiallj  many  of  the  best  established  coals,  and  as  might  d  priori  he  imagined,  they 
moreover  demonstrate  in  an  undeniable  manner  the  superiority  of  bituminous  over  antbra- 
citic  coals  and  coke,— a  position  directly  the  reverse  of  the  absurd  assumptions  and 
foregone  conclusions  contained  in  the  parliamentary  report  of  Sir  H.  de  la  Beche  and 
Dr.  Playfair.  The  following  is  a  tabular  view  of  these  results,  with  a  column  showing 
the  evaporative  power  of  each,  deduced  by  assuming  980  as  the  latent  beat  of  steam. 


Newcastle  : 
Pelton      - 
Garesfield  (Bates) 
Hastings  Hartley- 
West  Hartley     - 
Bates  Hartley  - 
Newcastle  Hartley 
Heat  on    - 
Gosford   - 
Killingworth    - 

Durham: 

Hetton    • 
Lambtoo 
Rainton  - 

YORKSHIKE  : 

Woodthorpe    - 
Mortemly 

North  "Wales  : 
Brymbo  - 
Ruabon   - 

South  "Wales  : 
Anthracite  No.  1. 
Anthracite  No.  2. 
Neath  (Bituminous) 

Ireland  : 
Anthracite 

"WlGAN  : 

Cannel  Ince  Hall 

Scotch: 

Lesmahago  Cannel  - 

Newcastle  : 

Ramsev's  Cannel 


Unities  of  Caloric. 


Lbs.  of  "Water 

caiMble  of  being 

evaporated  by  1  lb. 

of  Coal. 


14800 
15200 
16175 
16280 
15985 
16330 
15075 
16000 
14875 


15660 
15460 
14995 


13780 
14010 


13876 
14200 


13090 
12875 
18845 


12990 
14340 
12285 
14420 


lbs 


151 
15  5 
16-6 
16-6 
16-3 
16-6 
15-6 
158 
151 


160 
15-7 
15-3 


14-0 
14-3 


141 
145 


13-3 
131 
140 


18-2  — 
14-6  — 
12  5  — 
14-7  — 


Comparing  these  results  with  the  actual  working  of  most  of  the  above  bituminous 
coals,  it  appears  that  very  nearly  one  half  of  all  the  heat  evolved  is  lost  in  practice,  and 
either  passes  off  in  the  shape  of  unconsumed  fuel,  or  is  wasted  in  the  chimney.  With  a 
view  to  ascertain  how  much  of  the  loss  is  due  to  this  latter  circumstance,  Mr.  F.  J.  Evans, 
the  eminent  engineer  of  the  Westminster  station  of  the  Chartered  Gas  Company,  made 
some  time  ago  an  experiment  bearing  upon  this  subject,  and  in  which  the  loss  of  heat  is 
necessa  ily  very  high,  from  the  fact  that  the  substance  heated  by  the  fiirnnce  was  almost 
white  hot,  whereas  in  a  steam  boiler  the  temperature  never  exceeds  300°  of  Fahr.  Mr. 
Evans's  experiment,  which  shows  no  trifling  anK)unt  of  ingenuity,  nevertheless  demon- 
strates that  not  more  than  3  per  cent,  of  the  fuel  passes  off  by  the  heat  of  the  chimney ; 
consequently  at  least  15  times  this  amount  must  be  lost  by  im'perfect  combustion,  and  fly 
away  in  the  shape  of  carburetted  hydrogen,  tarry  vapour,  or  carbonic  oxide;  thus  leav- 
ing a  wide  field  for  improvement  in  burning  and  applying  fuel.  We  give  the  following 
in  Mr.  Evans's  own  words. 


.* 


U 


FUEL. 


826 


*'  *  Experiments  on  waste  heat :  to  determine  the  quantity  of  heat  going  away  to  the 
chimney  from  a  setting  of  8  retorts.  A  deal  box  was  constructed  of  the  following  dimen- 
sions ;  jfength  5  feet  6  inches,  width  11  inches,  and  depth  7  inches,  and  quite  water-tight 
Within  this  box,  and  running  through  it,  was  placed  an  iron  tube  of  the  following  dimen- 
sions ;  length  81  inches,  width  9  inches,  depth  3  inches.  This  tube  formed  by  subsequent 
arrangement  a  portion  of  the  flue  through  which  the  air  from  the  furnace  passed  to  the 
chimney,  as  is  shown  in  the  sketch  below,  where  a  represents  an  iron  plate  closing  the 
main  flue,  and  compelling  the  hot  air  to  pass  through  the  iron  tube  contained  in  th^ 
wooden  box,  into  which  water  was  ultimately  placed,  as  will  be  explained. 


V!!!Je^fei^^^>y^J^^.>-../>l^^/.-^iy^ 


I 


MAIN 


\  I 

V  I WOODEN     BOX 


,.MM^'^M2fJ2W}M>>JMJ....MJjmy>J»J^»^^^^^^ 


FLUE 


ii))}jy  ij '  rffwvj^f^rr^ 


'rtM.-,,,W^^.fl^'  f 


X    FOR  WATER 


IRON     TUBt      OR    TCMFORART      FLUE 


_ 


,J^^,,,,,^,,,,,,,,,,l>in»>ll»>tll>l>milUMn^,,%m.,,,,,,,•l•<>>>llln.^,yTr,frfm 


===A 


**  •  Matters  being  thus  arranged,  and  the  iron  plate  at  a  securely  fixed,  it  necessarily- 
followed  that  all  the  heat  from  the  setting  of  8  retorts  passed  through  the  81  inches  of 
iron  tube  contained  in  the  box,  and  would  therefore  impart  heat  to  the  water  placed  in 
that  box,  which  was  filled  with  this  fluid  at  71°  Fahr.  to  the  extent  of  112  lbs.  Thia 
water  being  kept  in  constant  motion  afforded  the  annexed  thermometric  indications. 


Commenced  experiment  at  6*45 
Observation  made  at  648 

6-51 
•  6-54 

«  6'57 

«  7-01 

"  706 

«  707 


Temperature  of  water. 
71° 
.       88 

-  94 

-  110 

-  114 

-  132 

-  148 

-  150 


Thus  showing  that  112  lbs.  of  water  were  raised  89°  in  22  minutes,  which  is  equal  to 
2-62  lbs.  of  water  at  32°  made  to  boil  in  each  minute.  Consequently  in  24  hoars 
8628-8  lbs.  of  such  water  might  be  made  to  boil,  or  6041  lbs.  of  water  be  converted 
into  steam  in  the  same  period  of  time,  and  as  coke  will  evaporate,  according  to  Lavoisier, 
more  than  10  times  its  weight  of  water,  this  implies  the  consumption  of  nearly  60^  lbs* 
of  coke,  the  heat  of  which  is  entirely  lost  in  the  chimney.  And  if  this  be  compared 
with  the  total  coke  consumed  for  24  hours  in  the  same  setting  of  retorts,  it  amounts  to 
about  3  per  cent,  only,  and  is  therefore  under  the  circumstances  remarkably  trifling.* 
Hence  it  would  appear,  as  has  been  before  remarked,  that  some  very  considerable 
improvements  are  needed  in  the  present  mode  of  consuming  bituminous  coals.  The  pro- 
bability is,  that  a  flat  boiler  surface  exposed  freely  to  a  single  sheet  of  flame  from  such 
coals  is  the  best  form,  for  it  is  certain  that  long  narrow  flues  act  like  the  meshes  of  wire 
gauze  upon  the  volatile  constituents,  and  cool  them  down  below  the  point  at  which 
Ignition  can  go  on.  In  support  of  this  view  we  have  only  to  recollect  that  though 
the  gases  from  a  blast  furnace  will  burn  freely  when  they  first  issue  from  the  fur- 
nace and  are  white  hot,  yet  after  being  once  cooled  down  to  the  ordinary  tempera- 
ture they  refuse  altogether  to  burn  or  afford  heat.  The  use  of  long  and  narrow 
flues,  with  combustibles  of  low  accendibility,  is  therefore  highly  improper,  and  suffi- 
ciently explains  the  miserable  results  arrived  at  by  the  Admiralty  coal  investigatong 
with  a  Cornish  boiler." — Mr.  L.  Thompson. 

FULGURATION  ;  designates  the  sudden  brightening  of  the  melted  gold  and  silver 
in  the  cupel  of  the  assayer,  when  the  last  film  of  vitreous  lead  and  copper  leaves 
their  surface. 

FULLER'S  EARTH,  {Terre  a  foulon,  Argile  Smectique,  Fr. ;  Walkererde,  Germ.) 
is  a  soft,  friable,  coarse  or  fine  grained  mass  of  lithomarge  clay.  Its  colour  is  greenish, 
or  yellowish  gray ;  it  is  dull,  but  assumes  a  fatty  lustre  upon  pressure  with  the  fingers, 
feels  unctuous,  does  not  adhere  to  the  tongue,  and  has  a  specific  gravity  varying  from 
1-82  to  219.  It  falls  down  readily  in  water,  into  a  fine  powder,  with  extrication  of  air 
bubbles,  and  forms  a  non-plastic  paste.  It  melts  at  a  high  heat  into  a  brown  slag.  Its 
constituents  are  53-0  silica;  100  alumina;  9*75  red  oxide  of  iron;  1-25  magnesia;  0'6 
lime;  24  water,  with  a  trace  of  potash.  Its  cleansing  action  upon  woollen  stuffs 
depends  upon  its  power  of  absorbing  greasy  matters.  It  should  be  neither  tenacious 
nor  sandy  ;  for  in  the  first  case,  it  would  not  diffuse   itself  well  through  water, 


826 


FULLING  MILL. 


and  in  the  second  it  would  abrade  the  cloth  too  much.  The  finely  divided  silica  is  one 
of  its  useful  ingredients. 

Fuller's  earth  is  found  in  several  counties  of  England;  but  in  greatest  abundance  in 
Bedfordshire,  Berkshire,  Hampshire,  and  Surry. 

In  the  county  of  Surry  there  are  great  quantities  of  fuller's  earth  found  about  Nut- 
field,  Ryegate,  and  Blechingley,  to  the  south  of  the  Downs,  and  some,  but  of  inferior 
quality,  near  Sutton  and  Croydon,  to  the  north  of  them.  The  most  considerable  pits 
are  near  Nutfield,  between  which  place  and  Ryegate,  particularly  on  Redhill,  about  a 
mile  to  the  east  of  Ryegate,  it  lies  so  near  the  surface  as  frequently  to  be  turned  up  by 
the  wheels  of  the  wagons.  The  fuller's  earth  to  the  north  of  the  road  between  Red- 
hill  and  Nutfield,  and  about  a  quarter  of  a  mile  from  the  latter  place,  is  very  thin ;  the 
seam  in  general  is  thickest  on  the  swell  of  the  hill  to  the  south  of  the  road.  It  is  not 
known  how  long  this  earth  has  been  dug  in  Surry ;  the  oldest  pit  now  wrought  is  said 
to  have  lasted  between  50  and  60  years,  but  it  is  fast  wearing  out.  The  seam  of  fuller's 
«arth  dips  in  different  directions.  In  one,  if  not  in  more  cases,  it  inclines  to  the  west 
.vith  a  considerable  angle.  There  are  two  kinds  of  it,  the  blue  and  the  yellow ;  the 
former,  on  the  eastern  side  of  the  pit,  is  frequently  within  a  yard  of  the  surface,  being 
covered  merely  with  the  soil— a  tough,  wet,  clayey  loam.  A  few  yards  to  the  west, 
the  blue  kind  appears  with  an  irony  sand-stone,  of  nearly  two  yards  in  thickness,  between 
it  and  the  soil.  The  blue  earth  in  this  pit  is  nearly  16  feet  deep.  In  some  places  the 
yellow  kind  is  found  lying  upon  the  blue ;  there  seems,  indeed,  to  be  no  regularity  either 
in  the  position  or  inclination  of  the  strata  where  the  fuller's  earth  is  found,  nor  any  mark 
by  which  its  presence  could  be  detected.  It  seems  rather  thrown  in  patches  than  laid  in 
any  continued  or  regular  vein.  In  the  midst  of  the  fuller's  earth  are  often  found  large 
pieces  of  stone  of  a  yellow  color,  translucent  and  remarkably  heavy,  which  have  been 
found  to  be  sulphate  of  barjtes,  encrusted  with  quartzose  crystals.  These  are  carefully 
removed  from  the  fuller's  earth,  as  the  workmen  say  they  often  spoil  many  tons  of  it 
which  lie  about  them.  There  is  also  found  with  the  yellow  fuller's  earth  a  dark  brown 
crust,  which  the  workmen  consider  as  injurious  also.  In  Surry  the  price  of  fuller's  earth 
seems  to  have  varied  very  little,  at  least  for  these  last  80  years.  In  1730,  the  price  at 
the  pit  was  6d.  a  sack,  and  6*.  per  load  or  ton.  In  1744,  it  was  nearly  the  same.  It  is 
carried  in  was:ons,  each  drawing  from  three  to  four  tons,  to  the  beginning  of  the  iron 
railway  near  Westham,  along  which  it  is  taken  to  the  banks  of  the  Thames,  where  it  is 
sold  at  the  different  wharves  for  about  25*.  or  26*.  per  ton.  It  is  then  shipped  off  either 
to  the  north  or  west  of  England. 

The  next  characteristic  stratum,  owing  to  its  forming  a  ridge  of  conspicuous  hills  through 
the  country,  is  the  AVoburn  land,  a  thick  ferruginous  stratum,  which  below  its  middle  con- 
tains a  stratum  of  fuller's  earth.  This  is  thicker  and  more  pure  in  Aspley  and  Hogstyc- 
end,  two  miles  north-west  of  Woburn,  than  in  any  known  place. 

Fuller's  earth  is  found  at  Tillington,  and  consumed  m  the  neighboring  fulling  mills. 

Mode  of  preparing  fuller's  earth  : — 

After  baking  it  is  thrown  into  cold  water,  where  it  falls  into  powder,  and  the  separ- 
ation of  the  coarse  from  the  fine  is  effectually  accomplished,  by  a  simple  method  used  in 
the  dry  color  manufactories,  called  washing  over.  It  is  done  in  the  following  manner: 
Three  or  four  tubs  are  connected  on  a  line  by  spouts  from  their  tops;  in  the  first  the 
earth  is  beat  and  stirred,  and  the  water,  which  is  continually  running  from  the  first  to 
the  last  through  intermediate  ones,  carries  with  it  and  deposites  the  fine  whilst  the  coarse 
settles  in  the  first.  The  advantages  to  be  derived  from  this  operation  are,  that  the  two 
Kinds  will  be  much  fitter  for  their  respective  purposes  of  cleansing  coarse  or  fine  cloth ; 
for  without  baking  the  earth  they  would  be  unfit,  as  before  noticed,  to  incorporate  so 
minutely  with  the  water  in  its  native  state ;  it  would  neither  so  readily  fall  down,  nor  so 
easily  be  divided  into  different  qualities,  without  the  process  of  washing  over.  When  fuel 
is  scarce  for  baking  the  earth,  it  is  broken  into  pieces  of  the  same  size,  as  mentioned 
above,  and  then  exposed  to  the  heat  of  the  sun. 

The  various  uses  of  fuller's  earth  may  be  shortly  explained.  Accordinar  to  the  above 
method,  the  coarse  and  fine  of  one  pit  being  separated,  the  first  is  used  for  cloths  of 
an  inferior,  and  the  second  for  those  of  a  superior  quality.  The  yellow  and  the  blue 
earths  of  Surry  are  of  different  qualities  naturally,  and  are,  like  the  above,  obtained  arti- 
ficially, and  used  for  different  purposes.  The  former,  which  is  deemed  the  best,  is 
employed  in  fulling  the  kerseymeres  and  finer  cloths  of  Wiltshire  and  Gloucestershire, 
whilst  the  blue  is  principally  sent  into  Yorkshire  for  the  coarser  cloths.  Its  effect  on 
these  cloths  is  owing  to  the  aflinity  which  alumine  has  for  greasy  substances ;  it  unites 
readily  with  them,  and  forms  combinations  which  easily  attach  themselves  to  different 
stuffs,  and  thereby  serve  the  purpose  of  mordants  in  some  measure.  The  fullers  generally 
apply  it  before  they  use  the  soap. 

FULLING;  for  the  theory  of  the  process,  see  Felting  and  Wool. 

FULLING  MILL.    Willan  and  Ogle  obtained  a  patent  in  1825  for  improved  ful- 


I 


■ 


FULMINATES. 


827 


66Y  ling  machinery,  designed  to  act  in  a  sim- 

ilar way  to  the  ordinary  stocks,  in  which 
cloths  are  beaten,  for  the  purpose  of  wash- 
ing and  thickening  them ;  but  the  standard 
and  the  bed  of  the  stocks  are  made  of  iron 
instead  of  wood  as  heretofore;  and  a  steam 
vessel  is  placed  under  the  bed,  for  heating 
the  cloths  during  the  operation  of  fulling ; 
whereby  their  appearance  is  said  to  be  great- 
ly improved. 

Fig.  667  is  a  section  of  the  fulling 
machine  or  stocks ;  a  is  a  cast-iron  pillar, 
made  hollow  for  the  sake  of  lightness ;  b 
is  the  bed  of  the  stocks,  made  also  of  iron, 
and  polished  smooth,  the  side  of  the  stock 
being  removed  to  show  the  interior ;  c  is 
the  lever  that  carries  the  beater  d.  The 
cloths  are  to  be  placed  on  the  bed  (,  at 
bottom,  and  water  allowed  to  pass  through  the  slock,  when  by  the  repeated  blows  of  the 
beater  </,  which  is  raised  and  let  fall  in  the  usual  way,  the  cloths  are  beaten,  and  become 
cleansed  and  fulled. 

A  pan  of  the  bed  at  e,  is  made  hollow,  for  the  purpose  of  forming  a  steam  box,  into 
which  steam  from  a  boiler  is  introduced  by  a  pipe  with  a  stop-cock.  This  steam  heats 
the  bed  of  the  stock,  and  greatly  facilitates,  as  well  as  improves  the  process  of  cleansing 
and  fulling  the  cloths. 

The  smoothness  of  the  surface  of  the  polisfcHl  metal,  of  which  the  bed  of  the  stock  is 
constituted,  is  said  to  be  very  much  preferable  to  the  rougbness  of  the  surface  of  wood 
of  which  ordinary  fullinsr  stocks  are  made,  as  by  these  iron  slocks  less  of  the  nap  or  felt 
of  the  cloth  is  removed,  and  its  appearance  when  finished  is  T«ry  much  superior  to  cloths 
fulled  in  ordinary  stocks. 

In  the  operation  of  fulling,  the  cloths  are  turned  over  on  the  bed,  by  the  falling  of  the 
beaters,  but  this  turning  over  of  the  cloths  will  depend  in  a  great  measure  upon  the  form 
of  the  front  or  breast  of  the  slock.  In  these  improved  stocks,  therefore,  there  is  a  con- 
trivance by  which  the  form  of  the  front  may  be  varied  at  pleasure,  in  order  to  suit  cloths 
of  different  qualities;  /,  is  a  moveable  curved  plate,  constituting  the  front  of  the  stock; 
its  lower  part  is  a  cylindrical  rod,  extending  along  the  entire  width  of  the  bed,  and  being 
fitted  into  a  recess,  forms  a  hinge  joint  upon  which  the  curved  plate  moves ;  g,  is  a  rod 
attached  to  thp  back  of  the  curved  plate  /,  with  a  screw  thread  upon  it ;  this  rod  passes 
through  a  nut  A,  and  by  t'arning  this  nut,  the  rod  is  moved  backward  or  forward,  and  con- 
sequently the  position  of  the  curved  plate  altered. 

The  nut  hy  is  a  wheel  with  teeth,  taking  into  two  other  similar  toothed  wheels,  one  on 
each  side  of  it,  which  are  likewise  the  nuts  of  similar  rods  jointed  to  the  back  of  the 
curved  plate  /;  by  turning  the  central  wheel,  therefore,  which  may  be  done  by  a  winch, 
the  other  two  wheels  are  turned  also,  and  the  curved  plate  moved  backward  or  forward. 
At  the  upper  part  of  the  plate  there  are  pins  passing  through  curved  slots,  which  act  as 
guides  when  the  plate  is  moved. 

The  patentees  state  in  conclusion,  that  steam  has  been  employed  before  for  heating 
cloths  while  fulling  them,  they  therefore  do  not  exclusively  claim  its  use,  except  in  the 
particular  way  described ;  the  advantages  arising  from  the  construction  of  iron  stocks, 
with  polished  surfaces  in  place  of  wooden  ones,  together  with  the  moveable  curved  plates 
described,  are  in  their  opinion  "  sufliciently  important  to  constitute  a  patent  right." 

FULMINATES,  or  fulminating  powders.  Of  these  explosive  compounds,  there  are 
several  speqies;  such  as  fulminating  gold,  mercury,  platinum,  silver;  besides  the  old 
fusible  mixture  of  nitre,  sulphur,  and  potash.  The  only  kind  at  all  interesting  in  a  man- 
ufacturing point  of  view  is  the  fulminate  of  mercury,  now  so  extensively  used  as  a  pri- 
ming to  the  caps  of  percussion  locks.  Having  published  a  paper  in  the  Journal  of  the 
Royal  Institution  for  1831,  upon  gunpowder  (see  Gunpowder),  the  result  of  an  elaborate 
suite  of  experiments,  I  was  soon  afterwards  requested  by  the  Hon.  the  Board  of  Ordnance 
to  make  such  researches  as  would  enable  me  to  answer,  in  a  satisfactory  practical  manner, 
a  series  of  questions  upon  fulminating  powders,  subservient  to  the  future  introduction  of 
percussion  muskets  into  the  British  army.  The  following  is  a  verbatim  copy  of  my  re- 
port upon  the  subject : — 

To  the  Secretary  of  the  Board  of  Ordnance. 
"  Sir,— I  have  the  honor  of  informing  you,  for  the  instruction  of  the  Honorable  the 
Master  General  and  the  Board  of  Ordnance,  that  the  researches  on  fulminating  mercury, 
which  I  undertook  by  their  desire,  have  been  brought  to  a  satisfactory  conclusion,  after 


.! 


828 


FULMINATES. 


a  numerous,  diversified,  and  somewhat  hazardous  series  of  experiments.     The  following 
are  the  questions  submitted  to  me,  with  their  respective  answers : — 

Question  1,  What  proportions  of  mercury,  with  nitric  acid  and  alcohol  of  certain 
strengths,  will  yield  the  greatest  quantity  of  pure  fulminate  of  mercury  ? 

jlnswer.  One  hundred  parts,  by  weight,  of  mercury,  must  be  dissolved  with  a  gentle 
heat,  in  1000  parts  (also  by  weight)  of  nitric  acid,  spec.  gr.  1*4;  and  this  solution,  at 
the  temperature  of  about  130°  Fahr.,  must  be  poured  into  830  parts  by  weight  of  alcohol, 
spec.  gr.  0-330. — Note.  830  parts  of  such  alcohol,  by  weight,  constitute  1000  by  measure ; 
and  1000  parts  of  such  nitric  acid,  by  weight,  constitute  740  by  measure.  Hence,  in 
round  numbers,  one  ounce  weight  of  quicksilver  must  be  dissolved  in  7i^  oz.  measures  of 
the  above  designated  nitric  acid,  and  the  resulting  solution  must  be  poured  into  10  oz. 
measures  of  the  said  alcohol. 

Question  2.  What  is  the  most  economical  and  safe  process  for  conducting  the  manipu- 
lation, either  as  regards  the  loss  of  nitrous  gas  and  residuum,  or  as  respects  danger  to 
the  operator ;  also,  what  is  the  readiest  and  safest  mode  of  mixing  the  fulminate  inti- 
mately with  its  due  proportions  of  common  gunpowder. 

Answer.  The  mercury  should  be  dissolved  in  the  acid  in  a  glass  re*ort,  the  beak  of 
which  is  loosely  inserted  into  a  large  balloon  or  bottle  of  glass  or  earthenware,  whereby 
the  offensive  fumes  of  the  nitrous  gas  disengaged  during  the  solution,  aie,  in  a  consider 
able  measure,  condensed  into  liquid  acid,  which  should  be  returned  into  the  retort.  As 
soon  as  the  mercury  is  all  dissolved,  and  the  solution  has  acquired  the  prescribed  tem- 
perature of  about  130°,  it  should  be  slowly  poured,  through  a  glass  or  porcelain  funne*^ 
into  the  alcohol  contained  in  a  glass  matrass  or  bottle  capable  of  holding  fully  6  times 
the  bulk  of  the  mixed  liquids.  In  a  few  minutes  bubbles  of  gas  will  proceed  from  the 
bottom  of  the  liquid;  these  will  gradually  increase  in  number  and  magnitude  till  a  gen- 
eral fermentative  commotion,  of  a  very  active  kind,  is  generated,  and  the  mixture  assumes 
a  somewhat  frothy  appearaiice.  A  white  voluminous  gas  now  issues  from  the  orifice  of 
the  matrass,  which  is  very  combustible,  and  must  be  suffered  to  escape  freely  into  the 
air,  at  a  distance  from  any  flame.  These  fumes  consist  of  an  ethereous  gas,  holding 
mercury  in  suspension  or  combination.  I  have  made  many  experiments  with  the  view 
of  condensing  this  gas,  or,  at  least,  the  mercury,  but  with  manifest  disadvantage  to  the 
perfection  of  the  process  of  producing  fulminate.  When  the  said  gas  is  transmitted, 
through  a  glass  tube,  into  a  watery  solution  of  carbonate  of  soda,  a  little  oxyde  of 
mercury  is,  no  doubt,  recovered ;  but  the  pressure  on  the  fermentative  mixture,  though 
slight,  necessary  to  the  displacement  of  the  soda  solution,  seems  to  obstruct  or  impair 
the  generation  of  the  fulminate ;  this  effect  is  chiefly  injurious  towards  the  end  of  the 
operation,  when  the  gaseous  fumes  are  strongly  impregnated  with  nitrous  gas.  When 
this  is  not  allowed  freely  to  come  off,  a  portion  of  subnitrate  or  nitrate  of  mercury  is  apt 
to  be  formed,  to  the  injury  of  the  general  process  and  the  product. 

As  soon  as  the  effervescence  and  concomitant  emission  of  gas  are  observed  to  cease, 
the  contents  of  the  matrass  should  be  turned  out  upon  a  paper  double  filter,  fitted  into  a 
glass  or  porcelain  funnel,  and  washed  by  the  affusion  of  cold  water  till  the  drainings  no 
longer  redden  litmus  paper.  The  powder  adhering  to  the  matrass  should  be  washed  out 
and  thrown  on  the  filter  by  the  help  of  a  little  water.  Whenever  the  filter  is  thoroughly 
drained,  it  is  to  be  lifted  out  of  the  funnel,  and  opened  out  on  plated  copper  or  ston« 
ware,  heated  to  212°  Fahr.  by  steam  or  hot  water.  The  fulminate,  being  thus  dried,  is  to 
be  put  up  in  paper  parcels  of  about  100  grains  each ;  the  whole  of  which  may  be  aAer- 
wards  packed  away  in  a  tight  box,  or  a  bottle  with  a  cork  stopper.  The  excellence  of 
the  fulminate  may  be  ascertained  by  the  following  characters.  It  consists  of  brownish- 
gray  small  crystals  which  sparkle  in  the  sun,  are  transparent  when  applied  to  a  slip  of 
glass  with  a  drop  of  water,  and  viewed  by  transmitted  light.  These  minute  spangles 
are  entirely  soluble  in  130  limes  their  weight  of  boiling  water  ;  that  is  to  say,  an  imperial 
pint  of  boiling  water  will  dissolve  67  grs.  of  pure  fulminate.  Whatever  remains  indicates 
impurity.  From  that  solution  beautiful  pearly  spangles  of  fulminate  fall  down  as  the 
liquid  cools. 

It  may  now  be  proper  to  show  within  what  nice  and  narrow  limits  the  best  proportions 
of  the  ingredients  used  in  making  the  fulminate  of  mercury  lie.  The  following  are 
selected  from  among  many  experiments  instituted  to  determine  that  point,  as  well  as  the 
most  economical  process. 

1.  According  to  the  formula  given  by  the  celebrated  chemist  Berzelius,  in  the  4th 
vol.  of  his"Traite  de  Chimie,"  recently  published  (p.  383),  the  mercury  should  be 
dissolved  in  12  times  its  weight  of  nitric  acid,  sp.  gr.  1-375;  and  alcohol  of  sp.  gr. 
0-8.50,  amounting  to  16-3  limes  the  weight  of  the  mercury,  should  be  poured  at  inter- 
vals into  the  nitric  solution.  The  mixture  is  then  to  be  healed  till  effervescence  with  the 
characteristic  cloud  of  gas  appears.  On  the  action  becoming  violent,  alcohol  is  to  b€ 
poured  in  from  time  to  time  to  repress  it,  till  additional  16.3  parts  have  been  em* 
ployed. 

On  this  process  I  may  remark,  that  it  is  expensive,  troublesome,  dangerous,  and  un- 
productive of  genuine  pure  fulminate.      One  fifth  more  nitric  acid  is  expended  very 


FULMINATES. 


829 


♦ 


II 


., 


nearly  than  what  is  necessary,  and  almost  four  times  the  weight  of  alcohol  which  b 
beneficial.  Of  alcohol  at  0-83,  8-3  parts  by  weight  are  sufficient ;  whereas  Berzelius 
prescribes  nearly  4  times  this  quantity  in  weight,  though  the  alcohol  is  somewhat  weaker, 
being  of  sp.  gr.  0-850.  By  using  such  an  excess  of  alcohol,  much  of  the  fulminate  is 
apt  to  be  revived  into  globules  of  quicksilver  at  the  end  of  the  process,  as  I  shc-sred 
in  my  paper  on  this  subject  published  in  the  Journal  of  the  Royal  Institution  two  years 
ago.  There  is  no  little  hazard  in  pouring  th-  alcohol  into  the  nitric  solution ;  for  at 
each  affusion  an  explosive  blast  takes  place,  whereas  by  pouring  the  solution  into  the 
alcohol,  as  originally  enjoined  by  the  Hon.  Mr.  Howard,  the  inventor  of  the  process,  no 
danger  whatever  is  incurred.  100  parts  of  mercury  treated  in  the  way  recommended 
by  Berzelius  afforded  me  only  112  parts  of  fulminate,  instead  of  the  130  obtained  by  my 
much  more  economical  and  safe  proportions  and  process  from  the  same  weight  of  Juick- 
•ilver. 

2.  If  10  parts  of  nitric  acid  of  sp.  gr.  1-375  be  used  for  dissolving  1  of  quicksilver, 
and  if  14  parts  of  alcohol  of  sp.  gr.  0*85  be  thereafter  mixed  with  the  solution,  the  pro- 
duct  of  such  proportions  will  either  be  not  granular,  and  therefore  not  fulminating,  or 
it  will  be  partially  gianular  and  partially  pulverulent,  being  a  mixture  of  fulminate  and 
subnitrate  of  mercury  ill  adapted  for  priming  detonating  caps.  Instead  of  130  parts  of 
genuine  fulminate,  as  I  do  obtain,  probably  not  more  than  10  parts  of  powder  will  be 
produced,  and  that  of  indifferent  quality.  In  fact,  whenever  the  ethereous  fermentation 
is  defective,  or  not  vigorous,  little  true  fulminate  is  generated ;  but  much  of  the  mercury 
remains  in  the  acidulated  alcoholic  liquid. 

3.  If  the  alcohol  be  poured  in  successive  portions,  and  of  proper  strength  (sp.  gr.  0-83), 
into  a  proper  nitric  solution  of  mercury,  the  explosive  action  which  accompanies  each 
affusion  dissipates  much  of  the  alcohol,  and  probably  impairs  the  acid,  so  that  the  sub- 
sequent ethereous  fermentation  is  defective,  and  little  good  fulminate  is  formed.  From 
100  parts  of  mercury  submitted  to  this  treatment,  I  obtained  in  one  experiment,  carefully 
made,  only  51  parts  of  a  powder,  which  was  impalpable,  had  a  cream  color,  and  was  not 
explosive  either  by  heat  or  percussion. 

4.  When,  with  100  parts  of  mercury.  800  of  nitric  acid  of  sp.  gr.  1*375,  are  employed 
with  650  of  alcohol  of  sp.  gr.  '846,  no  fulminate  whatever  is  generated. 

5.  When,  with  the  proper  proportions  of  mercury,  acid,  and  alcohol,  the  process  is 
advanced  into  a  proper  energy  of  fermentative  commotion,  if  the  matrass  be  immersed  ix 
cold  water  so  as  materially  to  repress  that  action,  the  process  will  be  impaired,  and  wiH 
turn  out  ultimately  defective  both  as  to  the  quantity  and  quality  of  the  fulminate.  It  is 
therefore  evident  that  a  certain  energy  or  vivacity  of  etherization  is  essential  to  the  full 
success  of  this  curious  process,  and  that  anything  which  checks  it,  or  obstructs  its  taking 
place,  is  injurious  and  to  be  avoided. 

When  my  proportions  are  observed  in  making  fulminating  mercury,  somewhat  less 
than  one  fourth  of  the  nitric  acid  used  in  making  the  solution  remains  in  the  alcoholic 
mixture  along  with  the  fulminate.  When  other  proportions  are  taken,  much  more  acid 
remains.  This  acid  is  not  recoverable  to  any  useful  or  economical  purpose,  nor  is  the 
alcohol  that  is  associated  with  it.  Many  distillations,  with  various  reagents,  have  led  me 
to  this  practical  conclusion.  In  fact,  when  the  process  is  most  complete,  as  described  in 
the  first  paragraph,  the  alcohol  is  entirely  and  profitably  employed  in  etherization,  an 
generating  fulminic  acid. 

I  have  made  a  series  of  analytical  experiments  on  the  pure  fulminate  of  mercury,  with 
the  view  of  determining  its  composition,  the  quantity  of  quicksilver  present  in  it,  and 
consequently  the  loss  of  mercury  in  the  operation.  I  have  stated  that  my  maximum  pro- 
duct of  fulminate  from  100  grs.  of  quicksilver  is  130  grs.  Occasionally,  from  slight  dif- 
ferences in  the  temperature  of  the  mixture,  or  the  ambient  atmosphere,  2  grs.  less  may 
be  obtained. 

A.  I  dissolved  130  grs.  with  a  gentle  heat  in  muriatic  acid  contained  m  a  small  matrass 
adding  a  few  drops  of  the  nitric  to  quicken  the  solution.  On  evaporating  it  to  dryness 
with  much  care  to  avoid  volatilization  of  the  salt,  I  obtained  125  grs.  of  corrosive  sub- 
limate or  bi-chloride  of  mercury.  But  125  grs.  of  this  bi-chloride  contain  only  9M 
grs.  of  quicksilver.  Therefore,  by  this  experiment,  130  grs.  of  fulminate  contain  no 
more  than  9M  of  mercury,  indicating  an  exhalation  of  8*9  parts  in  the  form  of  fumes, 
or  a  retention  in  the  residuary  liquid  of  some  of  these  8-9  parts,  out  of  the  100  originally 
employed. 

B.  In  another  experiment  for  analysis,  130  grs.  dissolved  as  above,  were  thrown 
down  by  carbonate  of  soda.  95  grs.  of  black  oxyde  of  mercury  were  obtained,  which 
are  equivalent  to  91-2  grs.  of  quicksilver ;  affording  a  confirmation  of  the  preceding 
result. 

C.  130  grs.  of  fulminate  were  dissolved  in  strong  muriatic  acid,  and  the  solution  was 
decom{»osed  by  crystals  of  proto-muriate  of  tin  at  a  boiling  temperature.  The  mercury 
was  precipitated  in  globules  to  such  amount  as  to  verify  the  two  preceding  exper- 
iments. 

Regarding  fulminate  of  mercury  as  a  bi^yanate,  that  is,  as  a  compound  of  one  aton 


i* 


830 


or 
find 


FULMINATES. 

one  equivalent  prime  of  deutoxyde  of  mercury  and  two  primes  of  cyanic  acid,  we  sluOl 
d  ite  theoretical  composition  to  be  as  follows,  hydrogen  bemg  the  radix,  or  1. 


ipositi( 

2  primes  of  Cyanic  or  Fulminic  Acid  =  34  X  2  =  68 
Deutoxyde  of  Mercury  =  216 

284 


24 
76 

100 


As  these  284  parts  of  fulminate  contain  200  of  quicksilver  so  142  parts  of  f"l«"n*te 
wiU  contain  100  of  quicksilver.  Whence  it  appears,  that  when  only  130  parts  of  ful- 
m  naS^nV  obtained  in  practice  from  100  of  quicksilver,  8^  parts  of  qu.cks.lver  out 
Tf  the  1^  aVe  unproductive,  that  is,  are  expended  in  the  etherized  gas,  or  eft  m  the 
res  duarfacidulous  liquid.  By  the  above  experimental  and  theoretical  analysis  91 -6 
parts  of  VTcksilver  enter  into  the  composition  of  130  parts  of  true  crystalline  fuljninate^ 
Ke  complete  accordance  here  exhibited  between  theory  and  practice  removes  every 
shadow  of  doubt  as  to  the  accuracy  of  the  statements.  100  parts  of  fulminate  con- 
sist of — 

Mercury  )  70-4  >  p^roxyde  76-0 

Oxygen    ^    5-b  > 

Fulminic  acid  -        -  24 

1000 
Question  3.    May  the  gas  or  vapor  produced  by  the  inflammation  of  the  fulminate  of 
mercury,  when  combined  with  a  portion  of  gunpowder,  be  considered  in  its  nature  corro- 

"^^T^trer!"  Thav?  suggested  to  Mr.  Lovell,  of  Waliham  Abbey  works,  that  the  ful- 
minate may  be  probably  diluted  most  advantageously  with  spirit  varnish  made  o  a 
proper  consistence  by  dissolving  sandarach  in  alcohol.  When  well  mixed  with  this 
varnish,  a  small  drop  of  the  mixture  will  suffice  for  priming  each  copper  cap  or  disc; 
and  as  the  spirit  evaporates  immediately,  the  fulminate  will  be  fixed  to  the  copper 
beyond  the  risk  of  shaking  or  washing  away.  On  the  Continent,  tincture  of  benjamm 
is  used  for  the  same  purpose ;  but  as  that  balsamic  resin  leaves  in  ^o/nbustion  a  volu- 
minous coal,  which  sandarach  does  not,  the  latter,  which  is  the  mam  ««««  f  "^»'J^f 
spirit  varnish,  seems  better  adapted  for  this  purpose.  It  is  sufficiently  combustible,  and 
may  be  yet  m'ade,  by  a  due  proportion,  to  soften  the  violence  of  the  explosive  mercury 
on  the  nipple  of  the  touch-hole.  Fulminate  prepared  by  my  fornjula  has  no  con-osive 
influence  whatsoever  on  iron  or  steel;  and,  therefore,  if  such  a  medium  of  applying  it,  as 
I  have  now  taken  leave  to  suggest,  should  be  found  to  answer,  all  fears  on  the  score  of 

corrosion  may  for  ever  be  set  at  rest.        ^  „  ,    .  ,  j    m-  vi«  t^Ko  offr./.to/i 

Quesfion  4.  How  far  is  the  mixture  (of  fulminate  and  gunpowder)  liable  to  be  affected 
by  the  moisture  of  the  atmosphere,  or  by  the  intrusion  of  water;  and  will  such  an  acci- 
dent  affect  its  inflammability  when  dried  agam  ?  .  ,       ,        ,  ,„„„„  „„ 

jlnsvoer.  Well  made  fulminate,  mixed  with  gunpowder  and  moistened,  undergoes  no 
change,  nor  is  it  apt  to  get  deteriorated  by  keeping  any  length  of  time  in  a  damp  climate 
or  a  hazy  atmosphere.  Immersion  in  water  would  be  apt  to  wash  the  nitre  out  of  the 
pulvertne;  but  fhis  result  would  be  prevented  if  the  match  or  priming  mixture  were 
liquefied  or  brought  to  the  pasty  consistence,  not  with  water,  but  spirit  varnish.  Such 
detonating  caps  would  be  indestructible,  and  might  be  alternately  moistened  and  diied 

^'q^tiam'  Is  it  at  all  probable  that  the  composition  would  be  rendered  more  inflam- 
mable or  danirerous  of  use  by  the  heat  of  tropical  climates  ? 

jltiswer.  No  elevation  of  temperature  of  an  atmospheric  kind,  compatible  with  hu- 
man existence,  could  cause  spontaneous  combustion  of  the  fulminating  mercury,  or  the 
detonating  matches  made  with  it.  In  fact,  its  explosive  temperature  is  so  high  as  367- 
of  Fahrenheit's  scale,  and  no  inferior  heat  will  cause  its  detonation. 

Question  6.  Is  the  mercurial  vapor  or  gas  arising  from  the  ignition  of  a  great  number 
of  primers,  and  combined  with  the  smoke  of  gunpowder  in  a  confined  space  (as  in  the 
case  of  trcips  in  close  bodies,  squares,  casemates,  &c.),  likely  m  its  nature  to  be  found 

oreiudicial  to  human  health  ?  ^        .        /.  r  i    •     #-  «i 

JSnswer  I  have  exploded  in  rapid  succession  of  portions,  100  grains  of  fulminate  ol 
mercury  (equivalent  to  300  or  400  primers),  in  a  close  chamber  of  small  d»jnens»o««J 
without  exneriencing  the  slightest  inconvenience  at  the  period,  or  afterwards,  though  my 
held  was  surrounded  by  the  vapors  aU  the  time  of  the  operation.  These  vapors  are,  m 
fact%rhe;Tthat  they'subside'almost  immediate^^  When  the  ruhninate  mixed  wih 
nulverine  is  exploded  in  the  primers  by  condensed  masses  of  troops,  the  mercary  wiii 
Lte  no  /nju^/to  their  health  nor  100th  part  of  the  deleteho'is.  impressi^^^^^^^ 
lungs  which  the  gases  of  exploded  gunpowder  might  by  Ppssibihty  inflict  These  g^e. 
are  all,  theoretically  speaking,  noxious  to  respiration  ;  such  as  carbonic  f^J^  ?a^^^^^ 
carbureted  hydrogen,  and  sulphureted  bydrosen  a  deadly  gas.  Yet  the  s^^^^^^^^  who 
•hould  betray  any  fear  of  gunpowder  smoke  would  be  an  object  of  just  ridicule. 


FULMINATES. 


831 


In  the  following  September,  I  executed  for  the  Board  of  Ordnance  a  set  of  experi- 
ments, complementary  to, those  of  the  memoir,  with  the  view  of  ascertaining  the  best 
manner  of  protecting  the  fulminate  when  applied  to  the  copper  caps,  from  being 
detached  by  carriage,  or  altered  by  keeping.  The  following  were  my  results  and  con- 
clusions. 1    V      41. 

« 1.  Fulminate  of  mercury  moistened  upon  copper  is  speedily  decomposed  by  the 
superior  affinity  of  the  copper  over  mercury,  for  oxygen  and  fulminic  acid.  Dryness 
is,  therefore,  essential  to  the  preservation  of  the  fulminate;  and  hence  charcoal,  which 
is  apt  to  beci.me  moist,  should  not  be  introduced  into  percussion  caps  destined  for  distant 
service 

2.  An  alcoholic  solution  of  sandarach,  commonly  called  spirit  varnish,  acts  power- 
fully on  copper,  with  the  production  of  a  green  efflorescence,  which  decomposes  ful- 
minate of  mercuiy.  Indeed,  sandarach  can  decompose  the  salts  of  copper.  It  is  there- 
fore ill  adapted  for  attaching  the  fulminate  to  copper  caps. 

3.  An  alcoholic  solution  of  shellac  acts  on   copper,  though  more  feebly  than  the 

sandarach.  ^  ,     ,        ,  .     ,      ...   r  i    • 

4.  A  solution  of  mastic  in  spirits  of  turpentine,  whether  alone  or  mixed  with  lulmi- 
nate,  has  no  action  whatever  on  bright  copper,  but  protects  it  from  being  tarnished.  Suck 
a  varnish  is  very  cheap,  dries  readily,  adheres  strongly,  screens  the  fulminate  from  danapj 
and  does  not  impair  or  counteract  its  detonating  powers.  This,  therefore,  is,  in  my  opin- 
ion, the  fittest  medium  for  attaching  the  fulminate,  and  for  softening  the  force  of  its  im- 
pulsion in  any  degree  preporlional  to  the  thickness  of  the  varnish." 

Fulminate  of  mercury  is  obtained  in  white  grains,  or  short  needles,  of  a  silky  lustre, 
which  become  gray  upon  exposure  to  light,  and  detonate  either  by  a  blow  or  at  a  heat  un- 
der 370°  F. ;  with  the  disengagement  of  azote,  carbonic  acid,  as  also  of  aqueous  and  mer- 
curial vapors ;  to  the  sudden  formation  of  which  gaseous  products  the  report  is  due.  It 
detonates  even  in  a  moist  condition ;  and  when  diy  it  explodes  readily  when  struck  between 
two  pieces  of  iron,  less  so  between  iron  and  bronze,  with  more  difficulty  between  marble 
and  glass,  or  between  two  surfaces  of  marble  or  glass.  It  is  hardly  possible  to  explode 
it  by  a  blow  with  iron  upon  lead ;  and  impossible  by  striking  it  with  iron  upon  wood.  It 
fulminates  easily  when  rubbed  between  two  wooden  surfaces  ;  less  so  between  two  of 
marble,  two  of  iron,  or  one  of  iron  against  one  of  wood  or  marble.  The  larger  its  crys- 
tals, the  more  apt  they  are  to  explode.  By  damping  it  with  5  per  cent,  of  water,  it  be- 
comes less  fulminating;  the  part  of  it  struck  still  explodes  with  a  proper  blow,  but  will 
not  kindle  the  adjoining  portion.  Though  moistened  with  30  per  cent,  of  water,  it  will 
occasionally  explode  by  trituration  between  a  wooden  muller  and  a  marble  slab,  but  only 
to  a  small  extent,  and  never  with  any  danger  to  the  operator.  When  an  ounce  of  it,  laid 
upon  the  bottom  of  a  cask,  is  kindled,  it  strikes  a  round  hole  down  through  it,  as  if  it 
had  been  exposed  to  a  four-pound  shot,  without  splintering  the  wood.  If  a  tram  of  ful- 
minate of  mercury  be  spread  upon  a  piece  of  paper,  covered  with  some  loose  gunpowder, 
in  exploding  the  former  the  latter  will  not  be  kindled,  but  merely  scattered.  When  gun- 
powder, however,  is  packed  in  a  cartridge,  or  otherwise,  it  may  be  certainly  kindled  by  a 
percussion  cap  of  the  fulminate,  and  more  completely  than  by  a  priming  of  gunpowder. 
8*  parts  of  gunpowder  exploded  by  a  percussion  cap,  have  an  equal  projectile  force  as  10 
exploded  by 'a  flint  lock.  If  we  add  to  this  economy  in  the  charge  of  the  barrel,  the 
saving  of  the  powder  for  priming,  the  advantage  in  military  service  of  the  percussion 

system  will  become  conspicuous.  .  .      i  i  -i    ni  iv  i  v 

The  French  calculate  that  1  kilogramme  of  mercury  will  furnish  IJ  kil.  (2t  lbs.  nearly) 
of  fulminate,  which  will  be  sufficient  to  charge  40,000  percussion  caps.  For  this  pur- 
pose they  grind  the  crystalline  salt  along  with  30  per  cent,  of  water  upon  a  marble  table 
with  a  wooden  muller;  mixing  with  every  10  parts  of  the  fulminate  6  of  gunpowder.  A 
consistent  dough  is  thus  obtained,  which,  being  dried  in  the  air,  is  ready  for  introducing 
into  the  bottoms  of  the  copper  caps.     One  quarter  of  a  grain  of  the  fulminate  is  said  to 

be  fully  sufficient  for  one  priming.  .  .        ,  . 

Mr.  Lovell,  of  the  Royal  Manufactory  of  Arms,  has  lately  executed  a  series  ot  experi- 
ments upon  priming  powders.  His  trials,  which  occupied  nearly  18  months,  were  made 
for  the  purpose  of  ascertaining  what  is  the  advantage  in  point  oi"  force  obtained  by  using 
percussion  primes.  He  had  anticipated  some  extra  energy  would  be  imparted  to  the 
charge  of  powder  in  the  barrel,  because  he  had  repeatedly  proved  that  a  good  strong  cap, 
exploded  by  itself  on  the  nipple  of  the  musket  (without  any  charge  of  gunpowder),  will 
exert  sufficient  force  upon  the  air  within  the  barrel  to  blow  a  candle  out  at  a  distance  of 
12  feet  from  the  muzzle.  He  concluded  also  that  stopping  the  escape  of  fluid  from  the 
vent  as  is  done  by  the  cap,  would  have  some  effect,  but  he  attributed  most  to  the  quick- 
ness'and  energy  with  which  the  powder  of  the  charge  is  ignited  by  the  vivid  stream  of 
flame,  generated  by  the  percussion  prime.  The  trials  were  made  from  one  and  the  same 
barrel,  having  a  percussion  lock  on  one  side  and  a  flint  lock  on  the  other.  The  balls  were 
fired  against  Austen's  recoiling  target,  a  very  delicate ;)/egom«<er,  beginning  with  a  charge 
of  150  grains  (the  present  musket  charge),  and  descending  by  10  grains  at  a  time  (firing 


832 


FURNACE 


descending  by  10  grains  at  a  time  (firing  30  rounds  with  each  weight),  down  to  60 
grains.  The  machine  marked  the  decrease  of  force  at  each  reduction  in  the  charge  verv 
^tisfactorilj,  and  the  result  of  the  whole  average  was  that  884  parts  of  eunoowder 
fired  by  percussion  are  equal  to  10  parts  fired  by  the  flint  e     F"«  uer 

To  find  out  what  sort  of  liberties  might  be  taken  with  fulminate  of  mercurv  in 
handhng  it,  he  placed  8  grains  on  an  anvil,  putting  the  end  of  a  steel  punch  gently  on 
the  top  of  it,  and  while  so  placed  he  covered  the  fulminate  over  with  a  drachm  of  drv 
gunpowder.  He  then  ignited  the  fulminate  by  a  blow  on  the  pimch  with  the  hamme? 
but  not  a  grain  of  the  gunpowder  was  lighted,  though  it  was  blown  about  in  all 
^Tl'Z^'  I  ^^^°  ^l""":^^  ^  ^'■^'"  ""^  fuhninate  as  thick  as  a  quill,  and  about  3  feet  lone 
end     flni%?  r  ITr*^  Ik  T'^^^"*^^^^^  gunpowder  except  about  an  inch  at  one 

^1  f\u  ^^^^^^  V^^  ^?*.  ''■^°'  ^^'^^  *^^  ^^«le  t»-»'°  ^e°t  oflF  without  blazing  a 
mS.h  W  n^Tr'^^rJ  T^'"^^  ^^  ^^^P^  *^S^^^^^  ^°^  ^1^^  »P  afterwards  with  a 
Jfafho;  ^Vfi!"  '^J'fu**^^?''  containing  500  copper  caps,  made  a  hole  in  the  top  of 
the  box,  and  through  this  hole  ignited  one  of  the  caps  in  the  middle,  by  means  of  the 
punch  and  hammer  on  the  outside ;  only  two  other  caps  besides  the  one  struck  exploded  • 
r^J.of' iT  ^^«,«",'*ta'°ed  by  the  remainder,  except  being  discoloured.  This  he  tried 
repeatedly  and  always  with  the  same  kind  of  result,  nevir  more  than  3  or  4  caps  ex 
pioding^  He  then  made  a  steel  rammer  red  hot,  and  passed  it  through  the  hole  in  the 
o^nZf  ?"  amongst  the  caps,  but  it  only  ignited  them  where  the  iron  came  in  actual 
^nlT  T  P"""!"^  composition ;  when,  however,  he  placed  a  few  grains  of  gun- 

off  the  whX  oTtheL      ''^^''        ^""^  "'°°  "^^^^"^  *^'''  ^""^  produced  a  flame  that  blew 

rJSl%?fnn^.*^'".^  has  been  tried  at  Woolwich,  where  large  packages  of  percussion  caps 
hi?  kV?k  f  "it^  have  been  fired  at  with  musquet  balls,  and  only  a  few  of  the  caps  actually 
fhiS,  1  exploded;  but  when  any  cartridges  were  connected  with  the  packages, 

the  whole,  caps  and  all,  were  blown  up.     The  flame  of  the  fulminate  is  therefore  ha- 
S!«K   ^;-w         ?^  ^"^  ""^""T-  «i^e'*ea^'  't  requires  for  making  primes  an  admixture  of  some 
?TTTl!rTXTS.**?^'T^^  *"  ^'"^^  gunpowder,  to  condense  or  modify  the  flame. 
t  ULMmiC   ACID ;    (Acid  fxdminique,    Fr. ;   Knalhaure,  Germ.)    is   the   explosive 

constituent  of  the  fulminating  mercury  of 
Howard,   and   the   fulminating   silver   of 
Brugnatelli,  being  generated   by  the  re- 
action of  alcohol  and  the  acid  nitrates  of 
these  metals.    It  is  a  remarkable  chemical 
fact,  that  fulminic  acid  has  exactly  the 
same  composition  as  cyanic  acid;  though 
the  salts  of  the  latter  possess  no  detonat- 
ing property,  and  afford,  in  their  decom- 
position by  an  oxygen  acid,  ammonia  with 
carbonic  acid ;  while  those  of  the  former 
afford  ammonia  and  prussic  acid.      All 
attempts   to  insulate  fulminic  acid   have 
proved  unsuccessful,  as  it  explodes  with 
the  slightest  decomposing  force.     It  con- 
sists, by  weight,  of  2  primes  of  carbon, 
1  of  azote,  and  1  of  oxygen  ;    or  of  two 
volumes  of  carbonic  acid,  and  one  of  azote;, 
When  two  different  bodies,  like  the  above, 
have  the  same  composition,  they  are  said 
to  be  isomeric. 

FUMIGATION,  is  the  employment  of 
fumes  or  vapours  to  purify  articles  of  ap- 
parel, and  goods  or  apartments  supposed 
to  be  imbued  with  some  infectious  or  con- 
tagious poison  or  fumes.  The  vapours  of 
vinegar,  the  fumes  of  burning  sulphur,  ex- 
plosion of  gunpowder,  have  been  long  pre- 
scribed and  practised,  but  they  have  iu  all 
probability  little  or  no  efficacy.  The  dif- 
fusion of  such  powerful  agents  as  chlorine 
gas,  muriatic  acid  gas,  or  nitric  acid  va- 
pour, should  alone  be  trusted  to  for  the 
destruction  of  morbific  effluvia. 
FUR ;  see  Peltrt. 

FURNACE  OF  ASSAY.  Under 
Assay.  I  have  referred  to  a  furnace  con- 
structed by  Messrs.  Anfrye  and  d'Arcet 


FUSEL  OIL. 


833 


"which  gives  some  peculiar  facilities  and  economy  to  the  ancient  process  by  fire.  It  had 
originally  a  small  pair  of  bellows  attached  to  it,  for  raising  the  heat  rapidly  to  the  proper 
vitrifying  pitch.  The  furnace,  17^  inches  high,  and  7^  inches  wide,  made  of  pottery  or 
fine  clay,  is  represented  Jig.  481.,  supported  upon  a  table,  having  a  pair  of  bellows 
beneath  it.  The  laboratory  is  at  6,  the  blow-pipe  of  the  bellows  at  d,  with  a  stop-cock, 
and  the  dome  is  surmounted  by  a  chimney  a,  c,  in  whose  lower  part  there  is  an  opening 
with  a  sliding  door,  for  the  introduction  of  the  charcoal  fuel.  The  furnace  is  formed  in 
three  pieces  ;  a  dome,  a  body,  and  an  ash-pit.  A  pair  of  tongs,  a  stoking-hook,  and 
cupel,  are  seen  to  the  right  hand,  and  the  plan  of  the  stone- ware  grate,  pierced  with 
conical  holes,  and  a  poker,  are  seen  to  the  left  This  grate  suits  the  furnace  repre- 
sented under  Assay.  The  following  are  comparative  experiments  made  by  means  of 
this  furnace : 


Numbers. 

Sliver  employed. 

IiCftd  employed. 

Time  of  A  ssay. 

Standards. 

Charcoal  used. 

1 
2 
3 
4 

1  Grain 

4  Grains. 

12  minutes. 

11 

13 

10 

947  milli^mes. 

950 

949 

949 

173  Grains. 
86 
93 
60 

Each  assay  was  therefore  performed  at  an  average  in  1 1^  minutes,  and  not  much  more 
than  a  quarter  of  a  pound  of  charcoal  was  used.  An  experiment  of  verification  in  the 
ordinary  assay  furnace  showed  the  standard  to  be  949  thousandths. 

This  furnace  becomes  a  very  convenient  one  for  melting  small  quantities  of  metals  in 
analyses,  by  removing  the  muffle,  and  closing  the  several  apertures  with  their  appropriate 
stoppers.  A  small  pedestal  may  be  then  set  in  the  middle  of  the  grate,  to  support 
a  crucible,  which  may  be  introduced  through  the  opening  h.  Coke  may  also  be  used 
as  fuel,  either  by  itself  or  mixed  with  charcoal.  For  descriptions  of  various  furnaces,  see 
Assay  ;  Beer  ;  Coppee  ;  Evaporation  ;  Iron  ;  Metallurgy  ;  Ores  ;  Silver  ;  Tin,  <fcc. 

FUR-SKIN"  DRESSING.  Fur-skins  are  usually  dressed  by  placing  them  in  their 
dried  state  in  tubs,  where  they  undergo  a  treading  operation  with  men's  feet,  until  they 
are  sufficiently  soft  and  bend  easily.  The  skins  if  large  are  sewn  up,  the  fur  being  turned 
inwards;  but  if  small  skins,  such  as  ermine,  are  being  dressed,  they  require  no  sewing. 
This  sewing  is  preparatory  to  the  greasing  with  butter  or  lard,  and  is  intended  to  ])rotect 
the  fur  from  the  grease,  and  to  promote  the  softening  in  the  succeeding  treading  opera- 
tion. The  skins  are  next  wetted,  and  their  flesh  is  removed ;  or  they  are  fleshed  and 
then  hung  up  to  dry.  They  are  again  subjected  to  treading  in  tubs  containing  sawdust; 
and  afterwards  in  tubs  containing  plaster  of  Paris,  or  whitening,  sprinkled  between  the 
skins.  They  are  then  beaten  with  a  stick,  and  combed ;  when  the  dressing  is  completed. 
M.  Pierre  Thirion  proposes,  in  his  patent  of  June,  1845,  to  soften  the  skins,  not  by  tread- 
ing, but  by  beating  stocks,  of  a  construction  like  the  fulling  mill.  They  are  next  sewn  up, 
and  again  fulled  in  a  strong  vessel,  where  they  are  forced  upwards  by  the  beaters,  turned 
over  and  over,  and  thus  speedily  softened.  They  are  now  fleshed,  and  then  returned 
to  the  beating  stocks,  and  mahogany  or  other  sawdust  is  sprinkled  upon  the  fur,  before 
the  beating  is  renewed.  They  are  next  placed  in  a  heated  barrel,  furnished  within  with 
radial  pins  for  turning  the  goods  over  ana  over,  in  order  that  they  may  be  acted  upon  by 
various  dry  substances,  which  are  thrown  into  the  barrel,  and  absorb  the  fat  from  tho 
skins.  Through  the  hollow  shaft  of  the  barrel,  steam  is  introduced,  which  heats  the 
skins,  softening  the  fivt,  which  is  then  absorbed  by  sand,  flour,  or  any  other  desiccative 
powder.  It  is  proper  to  take  the  skins  out  of  the  barrel  from  time  to  time  to  comb 
them.  Such  as  have  been  sufficiently  acted  upon  may  then  be  set  aside.  They  are  lastly 
freed  from  the  dust  by  being  subjected  to  a  grated  cylinder  in  a  state  of  rotation,  and 
then  combed  by  hand. 

FUSEL  OIL  is  the  German  name  of  the  offensive  smelling  oil  which  exists  in 
alcohol,  as  distilled  from  the  fermented  infusions  of  malt,  and  corn  meal  of  all  kinds,  as 
also  from  the  fermented  wash  of  potatoes,  and  of  beeis,  <fec.  A  like  oil  occurs  in 
the  alcohol  distilled  from  the  fermented  must  of  grapes,  and  the  juices  of  many  sweet 
fruits.  This  oil  is  not,  however,  identical  from  these  several  sources ;  as  may  indeed  be 
inferred  from  the  diversity  in  the  flavours  of  the  different  liquors.  But  they  all  a^ree  in 
being  somewhat  less  volatile  than  water,  and  therefore  make  their  appearance  chiefly  in 
the  spirits  towards  the  end  of  the  distillation  process.  It  is  to  the  presence  of  this  oil  that 
the  milkiness  of  the  last,  and  also  sometimes  of  the  first,  portions  of  the  spirit  that  come 
over,  called  feints,  owe  their  opalescence  and  their  penetrating  odour.  When  the  milky 
fluid  is  redistilled,  alcohol  and  water  first  pass  over  with  very  little  oil,  but  if  the  heat 
of  the  still  be  moderate,  the  oil  may  be  made  a  residuum,  and  obtained  in  a  tolerably 
concentrated  state.  The  oil  from  potatoes  was  first  analyzed  by  Dumas,  and  was  shown 
by  him  to  be  composed  of  68-2  per  cent,  of  carbon,  136  of  hydrogen,  and  18-2  of 
oxygen;  according  to  the  formula  CioHuO,  HO.    It  belongs  therefore  to  the  class  of 

53 


834 


FUSTIAN. 


alcohols,  one  whose  radical  is  CjoHn,  or  amyle,  and  is  an  amyl  oxyhydrate ;  just  aa 
common  alcohol  is  an  oxyhydrate  of  ethyle.  The  potato  amyle  spirit  is  a  colourless  fluid 
of  an  acrid  burning  taste,  and  of  a  most  offensive,  penetrating,  durable  smell.  When 
the  vapour  of  it  is  inhaled  it  produces  an  oppressive  nausea,  headache,  giddiness,  and 
retching.  It  has  a  poisonous  action  on  the  animal  system.  By  oxydizing  agents  it  is 
converted  into  valerianic  (Baldrian)  acid.  According  to  Balard  the  amyle  spirit  occurs 
along  with  the  senanthic  ether  in  the  oil,  which  contaminates  brandy,  and  is  probably 
derived  from  the  husks  of  the  grapes.  This  noxious  spirit  exists  most  abundantly  in 
the  whisky  of  malt,  and  especially  in  that  from  raw  grain  ;  and  is  now  an  article  of  con- 
siderable sale,  being  used  to  bum  m  lamps,  to  dissolve  copal  and  other  resins  for  varnish 
making  and  other  purposes. 

Besides  this  liquid  amyle  spirit  com  spirits  contain  a  concrete  fatty  matter,  of  a  brown 
colour,  an  acid  reaction,  and  an  offensive  smell  and  taste.  It  has  a  green  tinge,  which 
I  believe  is  derived  from  the  copper  worm  of  the  still.  Mulder  has  shown  that  this  fatty 
product  consists  of  an  easily  fusible  and  a  difficultly  fusible  portion.  The  former  he 
regards  as  the  ether  of  senanthic  acid;  consisting  of  85  carbon,  10*3  hydrogen,  and  4*8 
oxygen,  and  is  therefore  quite  different  from  the  amyle  spirit.  Margaric  acid  is  mixed 
with  the  less  fusible  portion.  He  says  that  one  million  parts  of  malt  whisky  contain 
30  of  aenanthic  acid,  9  of  aenanthic  ether,  and  5  of  corn  oil  (amyle  spirit).  There  are 
probably  many  varieties  of  these  oils  of  crude  alcohol. 

FUSIBILITY.    That  property  by  which  solids  assume  the  fluid  state. 

Some  chemists  have  asserted  that  fusion  is  simply  a  solution  in  caloric;  but  this  opinion 
includes  too  many  yet  undecided  questions,  to  be  hastily  adopted. 


Fusibility  of  Meialsy  as  given  by  M.  Thenard. 


1. 


Fusible  below  a 
red  heat. 


Infusible  below  a 
red  heat. 


Centigr. 

Mercury  — 39*> 

Potassium  +58° 
Sodium  90 

Tin  210 

Bismuth  256 

Lead  260 

Tellurium  A  little  less  fusible  than  lead. — ^Elaproth. 

Arsenic  Undetermined. 

Zinc  370°        Brongniart. 

Antimony  A  little  below  a  read  heat. 
Cadmium  Stromeyer. 

Pyrometer  of  Wedjewood. 


Gay  Lussac  and  Thenard. 

Newton. 
Biot. 


Silver 
Copper 
Gold 
Cobalt 

Iron 

Manganese 

Nickel 

Palladium 

Molybdenum 

Uranium 

Tungsten 


20         Kennedy. 

27  ) 

32  <     Wedgewood. 

A  little  less  diflicult  to  melt  than  iron. 
130         Wedgewood. 
158         Sir  G.  M'Kenzie. 
160  Guyton. 

As  manganese. — Richter. 

Nearly  infusible ;  and  to  be  obtained  at  * 
forge  heat  only  in  small  buttons. 


Infusible  at  the  forge  furnace, 
the  oxyhydrogen  blowpipe. 

FIP£. 


Fusible  a\ 
See  Blow- 


Chromium 

Titanium 

Cerium 

Osmium 

Iridium 

Khodium 

Platinum 

Colambium         J 
FUSIBLE  METAL.    See  Alloy. 

FUSTET.  (Fuslec,  Fr.)  The  wood  of  the  rhus  cotinus,  a  fugitive  yellow  dye. 
FUSTIAN  is  a  species  of  coarse  thick  tweeled  cotton,  and  is  generally  dyed  of  aa 
olive,  leaden,  or  other  dark  color.  Besides  the  common  fustian,  which  is  known  by  the 
name  of  pillow  (probably  pilaw),  the  cotton  stuffs  called  corduroy,  velverett,  velveteen, 
thicksett,  used  for  men's  wearing  apparel,  belong  to  the  same  fabric.  The  commonest 
iund  is  merely  a  tweel  of  four,  or  sometimes  five  leaves,  of  a  very  close  stout  texture, 
and  very  narrow,  seldom  exceeding  17  or  18  inches  in  breadth.  It  is  cut  from  the  loom 
in  half  pieces,  or  ends,  as  they  are  usually  termed,  about  35  yards  long,  and  after  under* 
going  the  subsequent  operations  of  dyeing,  dressing,  and  folding,  is  ready  for  tb^ 
market 


I 


FUSTIAN. 


835 


The  draught  and  cording  of  common  fustian  is  very  simple,  being  generally  a  regular 
or  unbroken  tweel  of  four  or  five  leaves.  Below  are  specimens  of  a  few  different  kinds, 
selected  from  those  most  general  in  Lancashire. 

The  number  of  leaves  of  heddles  are  represented  by  the  lines  across  the  paper,  and  the 
cording  by  the  ciphers  in  the  little  squares,  those  which  raise  every  leaf  bein?  distin- 
guished by  these  marks,  and  those  which  sink  them  left  blank,  as  more  particularly 
explained  in  the  article  Textile  Fabric. 

Of  velvet,  there  are  properly  only  two  kinds,  that  with  a  plain,  and  that  with  a  tweeled, 
or,  as  it  is  here  called,  a  Genoa  ground,  or  back.  When  the  material  is  silk,  it  is  called 
velvet,  when  cotton,  velveteen ;  and  this  is  the  sole  difference.  In  the  same  way  a  com- 
mon twceled  cloth,  when  composed  of  silk  is  called  satin ;  when  of  cotton,  fustian  oi 
jean  •  of  woollen,  plaiding,  serge,  or  kerseymere ;  and  in  the  linen  trade  is  distinguished 
by  a  variety  of  names  according  to  the  quality  or  fineness,  or  the  place  where  the  article 
is  manufactured. 


XVp.  1. — Pillow  Fustian. 

No.  2.- 

-Plain  Velveret. 

iO|    i    1    1       4               5 

1 

♦ 

1     |0|     1     1     i 

3          1 

" 

1     I0|     1     1           9          6 

* 

|0I     1     1     1     1 

5 

~ 

1     1     |0|     |6             2                  3 

« 

|0|     1     |0|0| 

0               2 

^■"  • 

1      1      1      I0|      5               1             4 

^ 

1      1      1      |0|      1 

6          4 

~ 

2    4    3     1 

4    6    2    3    1 

Of  the  above,  each  contains  four  leaves  of  heddles  or  healds ;  that  represented  by  No  1 
IS  wrought  by  four  treddles,  and  that  which  is  distinguished  by  No.  2  by  five ;  the  suc- 
cession of  inserting  the  threads  of  warp  into  the  heddles  will  be  discovered  by  the  figures 
between  the  lines,  and  the  order  in  which  the  treddles  are  to  be  successively  pressed 
down  by  the  figures  below. 


No.  3. — Double  Jean. 


No.  4.— Plain  Thickset. 


o| 


10 


(> 


I0| 


2 


I      I0|0|      I 


J_l|O|0|O|      I 


6      4 


I     |0|     |0|      4 


^         III 


4    2    3    1 


« 


0| 


U  |0 


3     I 


4    6 


1 

7 


These,  like  the  former,  are  wrought  with  leaves.     No.  3  requires  four,  and  No.  4  fire 
treddles.     The  succession  of  inserting  the  threads  of  warp,  and  of  workin?  the  treddles, 
are  marked  by  the  respective  numbers  between  and  under  the  lines,  as  in  the  former 
example.    Both  are  fabrics  of  cloth  in  very  general  use  and  estimation  as  low  priced- 
articles. 


No.  5.— Best  Thickset. 


No.  6.— Velvet  Tuft. 


|0i 


|0|_0_ 
0 


»        I     |Q|    1115 


1 


0 


»  I     |0|0|     I     I 


4      2 


.1     I0|0|     I     I 

6    4    2    3 
5 


« 


0 


0|0| 


1 


I     I     I     |0|     I 
6    4    2    3    1 


3      I 


These  are  further  specimens  of  what  may  be,  and  is,  executed  with  four  leaves,  and  in 
both  examples  five  treddles  are  used.  With  two  other  specimens  we  shall  conclude  our 
examples  of  this  description  of  work,  and  shall  then  add  a  very  few  specimens  of  the 
more  extensive  kinds. 


No.  7.--Cord  and  Velveret. 


No.  8.— Thickset  Cord. 


I    101    I    I    I 


I      I0|0|      I      I        5 
|0|      I     |0|0|    6 
I     I     I     |Q|     1  4 


3      1  (, 


|0|    I    loioi" 


I      I0|      I      I      I 

I  I  I  I  I  I 


4  2    3     1 

6     5 


± 

»  I      I0|0|      I     I 

5    4    3    2    1 


9      7 


10      8      6 


In  these  the  succession  of  drawing  and  working  are  marked  like  the  former.  The  next 
are  examples  of  patterns  wrought  with  six  leaves.  No.  9  has  eight,  and  No.  10  five 
neddles. 


836 


FUSTIAN. 


No.  9.— Double  Coriuroy. 


No.  10. — Genoa  Thickset. 


I    I    I    iO|    |0|    i» 


I    |oi    I    I    !0|    I 

I  0  I  0|0|0|0|     \     I 


Tl    I    iO|    io|    I 


I     MM     l"i     I     I     I 


01 


u 


o|     |0|0|     I 


|0|      |0|0| 


0|      |0|      |0| 


|0 


0 


2  4  6  8  10  12  3  1 
7  5 
11   9 


4  2  5  3  1 
8  6  11  9  7 
1    2   10 


!• 


In  both  these  the  warp  is  inserted  into  the  heddles  the  same  way.  The  difference  is 
enliiely  in  the  application  of  ihe  cords,  and  in  the  succession  of  pressing  u^wn  the 
treddles.  We  now  give  four  specimens  of  the  flushed  and  cut  work,  known  by  the  name 
of  velveteen.  They  are  also  upon  six  leaves,  and  the  difference  is  solely  in  the  cording 
tad  in  the  treading. 


No.  11. 


Queen's  Velveteens. 


No.  12. 


I     |0|     |U|0|     i 


f) 


I    I    |o|0|    I    I 


I    I    I    10  10  Id 
I    I    |0|    |0|    I 

|01     |0|0|     I     I 


0 


I    IQJ    |01 


|0|      |010| 


|0|0| 


o|    |0|    |o| 


I      |0|0| 


|0|0| 


1     2   12    8    4    2 
5    7  6 

9  11  10 

No.  13. — Plain  Velveteen. 


2    4     3 
6    8    7 
10  12  11   9 


1 


No.  14. — Genoa  Velveteen. 


1  I  I'M 


I  |0|  I 


|0| 


|0|0|  I 


1   I   |0| 


u 


I   |0|0|   |0 


0|0 


0|0|  |0|  I 


|0|0| 


|0|0|   |0j 


|0| 


3 
7 


4  8 


2 
6 
10 


8  12  3 

i 

11 


The  additional  varieties  of  figure  which  might  be  given  are  almost  endless,  but  the 
limits  of  this  article  will  not  admit  a  further  detail.  Those  already  given  are  the  articles 
in  most  general  use.  The  varieties  of  fancy  may  be  induked  to  a  great  extent;  but  it  is 
aniversally  found,  that  the  most  simple  patterns  in  every  department  of  ornamental 
weaving  are  those  which  attract  attention  and  command  purchasers.  We  shall  therefore 
only  add  two  examples  of  king's  cord  or  corduroy,  two  of  Genoa  and  common  velvet,  and 
two  more  of  jean.    These  will  be  found  below. 

No.  15.— King's  Cord.  No.  16.— Dutch  Cord. 


1   1   1   1    \^\^\ 

1 
2 

1     1     1 
1      |0| 

0|      1      1 

4         1 

1     1     |0|     1     |0| 

1      I0| 

5       a 

1     1     |0|0|     1     1 

7            3 

|0|     1 

|0|     1 

6        3 

1     1     1     |0|0|     t 

8            4 

1     |0| 

o|    1    1 

7 

"       1      |0|     1     lOjOl 

5 

10 

0|      |0| 

8 

|0|     |0|     1     1     1 

6 

|0|0| 

|0|0| 

9 

13    8    6    4    2 
5    7 

No.  17.— Genoa  Velvet. 

6    4 

2    3     1 
5 

No.  18.- 

—Plain  Velvet. 

■      1    1    I'M     1    MM 

1 

1     1     1 

III                       1 

"      1     |010|0|     1     I 

2 

1     1 

III                   2 

"     loiol    1    1    1    1 

3 

III                     3 

1    1    |0|0|    1    1 

4 

III                 * 

1      |0|      |0|     i      1 

5 

1      1      1      1              5 

1    I0|     |0|     1     1 

6 

1     1 

6 

2    4    8  12    3     1 
ft                     7    5 
10                  11    9 

1     3 

7    5 

4    2    8 

After  the  fustian  cloth  is  taken  from  the  loom-beam,  it  is  carried  to  the  cutter,  who 
nps  up  the  surface-threads  of  weft,  and  produces  thereby  a  hairy-looking  stuff. 


FUSTIC. 


837 


Preparatory  to  its  being  cut,  the  cloth  is  spread  evenly  upon  a  table  about  six  feet  long, 
upon  each  end  of  which  a  roller  mounted  with  a  ralchet- wheel  is  fixed;  the  one  to  ^ive 
off,  and  the  other  to  wind  up  the  piece,  in  the  above  six-feet  lengths. 

The  knife  is  a  steel  rod  about  two  feet  long,  and  three  eighths  of  an  inch  square,  hay- 
ing a  square  handle  at  the  one  end  ;  the  other  end  is  laperwl  away  to  a  blade,  as  thin  as 
paper.  To  prevent  this  point  from  turning  downwards  and  injuring  the  cloth,  its  under 
side  is  covered  by  a  guide  which  serves  to  stiffen  it,  as  well  as  to  prsvent  its  lower  edge 
from  cutting  the  fustian. 

The  operative  (male  or  female)  grasps  the  handle  in  the  right  hand,  and  insinuating 
the  projecting  point  of  the  guide  under  the  weft,  pushes  the  knife  smaitly  forward  through 
the  whole  length  of  six  feet,  with  a  certain  dexterous  movement  of  the  shoulder  and 
right  side,  balancing  the  body  meanwhile,  like  a  fencer,  upon  the  left  foot.  This  process 
is  repeated  upon  every  adhesive  line  of  the  weft. 

The  next  process  to  which  fustians  are  exposed  is  steeping  in  hot  water,  to  take  out 
the  dressing  paste.  They  are  then  dried,  reeled,  and  brushed  by  a  machine,  &c. 
From  twenty  to  thirty  pieces,  each  eighty  yards  long,  may  be  brushed  in  an  hour.  The 
breadth  of  the  cloth  is  twenty  inches.  The  maceration  is  performed  by  immersing  the 
bundled  pieces  in  tanks  of  water,  heated  by  waste  steam  ;  and  the  washing  by  means  of 
a  reel  or  winch,  kept  revolving  rapidly  under  the  action  of  a  stream  of  cold  water,  for 
an  hour  or  longer. 

After  being  thus  ripped  up,  it  is  taken  to  the  brushing  or  teazling  machine,  to  make  it 
shasgy. 

This  consists  of  a  series  of  wooden  rollers,  turning  freely  upon  iron  axles,  and  covered 
with  tin-plate,  rough  with  the  burs  of  punched  holes;  and  blocks  of  wood,  whose  con- 
cave under  surfaces  are  covered  with  card-cloth  or  card-brushes,  and  which  are  made  to 
traverse  backwards  and  forwards  in  the  direction  of  the  axes  of  the  revolving  rollers, 
during  the  passage  of  the  cloth  over  them. 

After  they  are  brushed  in  the  machine,  the  goods  are  singed  by  passing  their  cut  surface 
over  a  cylinder  of  iron,  laid  in  a  horizontal  direction,  and  kept  red  hot  by  a  flue.  See 
Sing  KING.  They  are  now  brushed  again  by  the  machine,  and  once  more  passed  over  the 
singeing  surface.  The  brushing  and  singeing  are  repeated  a  third,  or  even  occasionally 
a  fourth  lime,  till  the  cord  acquires  a  smooth  polished  appearance. 

The  goods  are  next  steeped,  washed,  and  bleached,  by  immersion  in  solution  of  chloride 
of  lime.  They  are  then  dyed  by  appropriate  chemical  means.  After  which  they  are 
padded  (imbued  by  the  padding  machine  of  the  calico  printers)  with  a  solution  of  glue, 
and  passed  over  steam  cylinders  to  stiffen  them. 

Smooth  fustians,  when  cropped  or  shorn  before  dyeing,  are  called  moleskins;  but  when 
shorn  afier  being  dyed,  are  called  beaverleen  :  they  are'both  tweeled  fabrics.  Cantoon  is 
a  fustian  wiih  a  fine  cord  visible  upon  the  one  side,  and  a  satiny  surface  of  yarns  running 
at  risht  angles  to  the  cords  upon  the  other  side.  The  satiny  side  is  sometimes  smoothed 
by  singeing.  The  stuff  is  strong,  and  has  a  very  fine  aspect.  Its  price  is  one  shilling 
and  sixpence  a  yard. 

Common  plain  fustian,  of  a  brown  or  drab  color,  with  satin  top,  is  sold  as  low  as 
seven  pence  a  yard. 

A  fustian,  with  a  small  cord  running  in  an  oblique  direction,  has  a  very  agreeable  ap- 
pearance. It  is  called  diagonal.  Moleskin  shorn,  of  a  very  strong  texture^  and  a  drab 
dyed  lint,  is  sold  at  20d.  per  yard. 

The  weight  of  90  yards  of  the  narrow  velveteen,  in  the  green  or  undressed  state,  is 
about  24  pounds.  The  goods  made  for  the  German,  Italian,  and  Russian  markets  are 
lighter,  on  account  of  the  peculiarity  in  the  mode  of  levying  the  import  duty  in  these 
countries. 

Velveteens  as  they  come  from  the  loom,  are  sold  wholesale  by  weight,  and  average  a 
price  of  20rf.  per  pound.  They  are  usually  woven  with  yarns  of  Upland  and  Brazil  cotton 
wool,  spun  together  for  the  warp ;  or,  sometimes,  New  Orleans  alone.  The  weft  is  usu- 
ally Upland,  sometimes  mixed  with  East  India  cotton  wools. 

Trouser  velveteens  are  woven  19  inches  wide,  if  they  are  to  be  cut  up;  if  not,  they 
are  woven  30  inches,  and  called  beaverleen. 

Cutting  or  cropping  fustians  by  hand  is  a  very  laborious  and  delicate  operation. 
The  invention  of  an  improved  apparatus  for  effecting  the  same  end  with  automatic  pre- 
cision and  despatch,  was  therefore  an  object  of  no  little  interest  to  this  peculiar  manufac- 
ture oC  Manchester.  An  ingenious  machine,  apparently  well  calculated  for  this  purpose, 
was  made  the  subject  of  a  patent  by  Messrs.  William  Wells  and  George  Scholefield,  of 
Salford,  in  November,  IK34. 

FUSTIC.  (Bois  jaune,  Fr. ;  Gelbholz,  Germ.)  The  old  fustic  of  the  English  dyer, 
as  the  article  fustet  is  their  yellow  fustic.  It  is  the  wood  of  the  Morus  tinctoria.  It  is 
lisrht,  not  hard,  and  pale  yellow  with  orange  veins ;  it  contains  two  coloring  matters,  one 
resinous,  and  another  soluble  in  water.  The  latter  resembles  weld,  but  it  has  more  of 
an  orange  cast,  and  is  not  so  lively. 


i 


838 


GALL-NUTS. 


Its  decoctions  in  water  are  brightened  by  the  addition  of  a  little  glue,  and  more  by  car 
died  milk.  This  wood  is  rich  in  color,  and  imparts  permanent  dyes  to  woollen  stuffs^ 
when  aided  by  proper  mordants.  It  unites  well  with  the  blue  of  the  indigo  vat,  and 
Saxon  blue,  in  producing  green  of  various  shades.  Alum,  tartar,  and  solution  of  tin, 
render  its  color  more  vivid  ;  sea  salt  and  sulphate  of  iron  deepen  its  hue.  From  5  to  6 
parts  of  old  fustic  are  sufficient  to  give  a  lemon  color  1o  16  parts  of  cloth.  The  color  of 
weld  is  however  purer  and  less  inclining  to  orange ;  but  that  of  fustic  is  less  affected  by 
acids  than  any  other  yellow  dye.  This  wood  is  often  employed  with  sulphate  of  iron  in 
producing  olive  and  brownish  tints,  which  agree  well  with  its  dull  yellow.  For  the  same 
reason  it  is  much  used  for  dark  greens. 

GABRONITE  is  a  yellowish  stony  substance,  of  a  greasy  lustre  and  spec.  gr.=2-74 ; 
affording  no  water  by  calcination ;  fusible  at  the  blowpipe  into  an  opaque  glass ;  soluble 
in  muriatic  acid ;  solution  affords  hardly  any  precipitate  by  oxalate  of  ammonia.  This 
mineral  is  distinguished  by  the  large  quantity  of  soda  which  it  contains ;  its  constituents 
being— silica,  54;  alumina,  24;  soda,  17-25;  magnesia,  1-5;  oxyde  of  iron,  1*25;  water, 
2.     It  belongs  to  the  species  Nepheline. 

GADOLINITE,  called  also  Yttrite  and  Ylterbite,  is  a  mineral  of  a  black,  brownish, 
or  yellowish  color,  granular,  or  compactly  vitreous,  and  conchoidal  fracture ;  of  spec, 
grav.  4-23  ;  readily  scratching  glass ;  fusible  at  the  blowpipe  into  an  opaque  glass,  some- 
times with  intumescence.  It  affords,  with  acids,  a  solution  that  lets  fall,  with  caustic 
soda,  a  precipitate  partly  re-soluble  in  carbonate  of  ammonia.  It  is  remarkable  for  con- 
taining from  45  to  55  per  cent,  of  the  earth  Yltria;  its  remaining  constituents  being  sili- 
ca, 25-8 ;  oxyde  of  cerium,  17-92;  oxyde  of  iron,  11-43.  This  mineral  is  very  rare,  hav- 
ing been  hitherto  found  only  in  the  neighborhood  of  Fahlon  and  Ytterby,  in  Sweden;  its 
peculiar  constituent  was  discovered  by  Professor  Gadolin. 

GALACTOMETER,  or  LACTOMETER,  is  an  instrument  to  ascertain  the  quality 
of  milk;  an  article  often  sophisticated  in  various  ways.  Fresh  milk,  rich  in  cream,  has  a 
less  specific  gravity  than  the  same  milk  after  it  has  been  skimmed ;  and  milk  diluted  with 
water  becomes  proportionably  lighter.  Hence,  when  our  purpose  is  to  determine  the 
quantity  of^  cream,  the  galactometer  may  consist  merely  of  a  long  graduated  glass  tube 
standing  upright  upon  a  sole.  Having  filled  100  measures  with  the  recent  milk,  we  shall 
see,  by  the  measures  of  cream  thrown  up,  its  value  in  this  respect.  A  delicate  long- 
ranged  glass  hydrometer,  graduated  from  1-000  up  to  1-060,  affords  the  most  convenient 
means  of  detecting  the  degree  of  watery  dilution,  provided  the  absence  of  thickening  ma- 
terials has  been  previously  ascertained  by  filtration.  Good  fresh  milk  indicates  from  1*030 
to  1-032;  when  the  cream  is  removed,  1-035  to  1-037.  When  its  density  is  less  than  1028, 
we  may  infer  it  has  been  thinned  with  water. 

GALBANUM  is  a  gum-resin,  which  occurs  sometimes  in  yellow,  shining  tears,  easily 
agglutinated  ;  of  a  strong  durable  smell ;  an  acrid  and  bitter  taste;  at  other  times  in  lumps. 
It  exudes  either  spontaneously  or  from  incisions  made  into  the  stem  oClhe  bubon  galbanum, 
a  plant  of  the  family  of  umbelliferaf  which  grows  in  Africa,  particularly  in  Ethiopia.  It 
contains  67  of  resin;  19-3  of  gum;  6-4  of  volatile  oil  and  water;  7-5  of  woody  fibres  and 
other  impurities ;  with  traces  of  acid  malate  of  lime. 

GALENA,  {Plomb  sulfure.Yt. ;  BUiglam,  Germ. ;)  is  a  metallic  looking  substance  of 
a  lead-gray  color,  which  crystaUizes  in  the  cubical  system,  and  is  susceptible  of  cleavages 
parallel  to  the  faces  of  the  cube ;  spec.  gr.  7-7592 ;  cannot  be  cut ;  fusible  at  the  blow- 
pipe with  exhalation  of  sulphureous  vapors ;  is  easily  reduced  to  metallic  lead.  Nitric 
acid  first  dissolves  it,  and  then  throws  down  sulphate  of  lead  in  a  white  precipitate;  the 
solution  affording,  wiih  plates  of  zinc,  brilliant  laminae  of  lead  (arbor  Saturni.)  It  con- 
sists of  sulphur,  13  ;  lead,  85 ;  with  a  little  iron,  and  sometimes  a  minute  quantity  of  silver. 
This  is  the  richest  ore  of  lead,  and  it  occurs  in  almost  every  geological  formation,  in 
veins,  in  masses,  or  in  beds.  It  is  almost  always  accompanied  by  sulphuret  of  zinc,  dif- 
ferent salts  of  lead,  heavy  spar,  fluor  spar,  &c.  Galena  in  powder,  called  Alquifoux,  is 
employed  as  a  glaze  for  coarse  stoneware. 

GALIPOT  is  a  name  of  a  white  semi-solid  viscid  rosin  found  on  fir-trees  ;  or  an  infe- 
rior sort  of  turpentine,  poor  in  oil. 

GALLATES ;  salts  consisting  of  gallic  acid  combined  with  bases ;  the  most  important 
being  that  with  oxyde  of  iron,  constituting  a  principal  part  of  the  black  dye. 

GALLIC  ACID  is  the  peculiar  acid  extracted  from  gall-nuts;  which  see. 

GALLIPOLI  OIL  is  a  coarse  olive  oil,  containing  more  or  less  mucilage ;  imported  from 
a  seaport  so  named,  of  the  province  of  Otranto,  in  the  kingdom  of  Naples. 

GALL-NUTS,  or  GALLS,  (Noix  de  Galle,  Fr. ;  Galldpfely  Germ. ;)  are  excrescences 
found  upon  the  leaves  and  leaf-stalks  of  a  species  of  oak,  called  Qxurcus  infecto- 
ria,  which  grows  in  the  Levant.  They  are  produced  in  consequence  of  the  puncture 
of  the  female  of  the  gall  wasp  (Cynips  folii  quercus),  made  in  order  to  deposite  her 


GALL-NUTS. 


839 


' 


eggs ;  round  which  the  juice  of  the  tree  exudes,  and  dries  in  concentric  portions.    When 
the  insect  gets  fully  formed,  it  eats  through  the  nut,  and  flies  off. 

The  Levant  galls  are  of  two  different  appearances  and  qualities;  the  first  aie  heayy 
compact,  imperforated,  the  insect  not  having  been  sufficiently  advanced  to  eat  its  way 
through  the  shell ;  prickly  on  the  surface ;  of  a  blackish  or  bluish  green  hue ;  about  the 
size  of  a  musket-ball.  These  are  called  blacky  blue,  or  Aleppo  galls.  The  second  are 
light,  spongy,  pierced  with  one  or  more  holes ;  smooth  upon  the  surface,  of  a  pale  grayish 
or  reddish  yellow  color,  generally  larger  than  the  first,  and  are  called  white  galls.  Be- 
sides the  galls  of  the  Levant,  others  come  from  Dalmatia,  Illyria,  Calabria,  &.c. ;  but  they 
are  of  inferior  quality,  being  found  upon  the  Quercus  Cerris  ;  they  are  smaller,  of  a  brown- 
ish color,  and  of  inferior  value.  The  further  south  the  galls  are  grown,  they  are  reckoned 
the  better. 

Galls  consist  principally  of  three  substances;  tannin  or  tannic  acid;  yellow  extractive; 
and  gallic  acid.  Their  decoction  has  a  very  astringent  and  unpleasant  bitter  taste.  The 
following  are  their  habitudes  with  various  reagents : — 

Litmus  paper  is  powerfully  reddened. 

Stannous  chloride  (protomuriate  of  tin)  produces  an  Isabel  yellow  precipitate. 

Alum ;  a  yellowish  gray  precipitate. 

Acetate  of  lead  ;  a  thick  yellowish  white  precipitate. 

Acetate  of  copper ;  a  chocolate  brown  precipitate. 

Ferric  sulphate  (red  sulphate  of  iron) ;  a  blue  precipitate. 

Sulphuric  acid ;  a  dirty  yellowish  precipitate. 

Acetic  acid  brightens  the  muddy  decoction. 

The  galls  of  the  Quercus  Cerris  and  common  oak  (Galles  a  Vepine,  Fr. ;  Knopper%f 
Germ.)  are  of  a  dark  brown  color,  prickly  on  the  surface,  and  irregular  in  shape  and  size. 
They  are  used  chiefly  for  tanning  in  Hungary,  Dalmatia,  and  the  southern  provinces  of 
the  Austrian  states,  where  they  abound. 

Tannin  or  tannic  acid  is  prepared  as  follows  :  Into  a  long  narrow  glass  adopter  tube, 
shut  at  its  lower  orifice  with  a  cotton  wick,  a  quantity  of  pounded  galls  are  put,  and 
slightly  pressed  down.  The  tapering  end  of  the  tube  being  inserted  into  a  matrass  or 
bottle,  the  vacant  upper  half  of  the  tube  is  filled  with  sulphuric  ether,  and  then  closed  with 
a  ground-glass  stopper.  Next  day  there  will  be  found  in  the  bottle  a  liquid  in  two  dis- 
tinct strata;  of  which  the  more  limpid  occupies  the  upper  part,  and  the  other,  of  a  sirupy 
consistence  and  amber  color,  the  lower.  More  ether  must  be  filtered  through  the  galls, 
till  the  thicker  liquid  ceases  to  augment.  Both  are  now  poured  into  a  funnel,  closed  with 
the  finger,  and  after  the  dense  liquor  is  setlled  at  the  bottom,  it  is  steadily  run  off"  into  a 
capsule.  This,  after  being  washed  repeatedly  with  ether,  is  to  be  transferred  into  a  stove 
chamber,  or  placed  under  the  receiver  of  an  air  pump,  to  be  evaporated.  The  residuary 
aiatter  swells  up  in  a  spongy  crystalline  form  of  considerable  brilliancy,  sometimes  color- 
less, but  more  frequently  of  a  faintly  yellowish  hue. 

This  is  pure  tannin,  which  exists  in  galls  to  the  amount  of  from  40  to  45  per  cent.  It 
is  indispensable  that  the  ether  employed  in  the  preceding  process  be  previously  agitated 
with  water,  or  that  it  contain  some  water,  because  by  using  anhydrous  ether,  not  a  parti- 
cle of  tannin  will  be  obtained. 

Tannic  acid  is  a  while  or  yellowish  solid,  inodorous,  extremely  astringent,  very  soluble 
In  water  and  alcohol,  much  less  so  in  sulphuric  ether,  and  uncrystallizable.  Its  watery 
solution,  out  of  contact  of  air,  undergoes  no  change;  but  if,  in  a  very  dilute  state, 
*t  be  leii  exposed  to  the  atmosphere,  it  loses  gradually  its  transparency,  and  lets  fall  a 
slightly  grayish  crystalline  matter,  consisting  almost  entirely  of  gallic  acid.  For  procuring 
this  acid  in  a  perfectly  pure  state,  it  is  merely  necessary  to  treat  that  solution  thus 
changed  with  animal  charcoal,  and  to  filter  it,  in  a  boiling  state,  through  paper  pre- 
viously washed  with  dilute  muriatic  acid.  The  gallic  acid  will  fall  down  in  crystals  as 
the  liquid  cools. 

If  the  preceding  experiment  be  made  in  a  graduated  glass  tube  containing  oxygen  over 
mercury,  this  gas  will  be  absorbed,  and  a  corresponding  volume  of  carbonic  acid  gas  will 
be  disengaged.  In  this  case  the  liquor  will  appear  in  the  course  of  a  few  weeks  as  if 
traversed  with  numerous  crystalline  colorless  needles  of  gallic  acid. 

Tannin  or  tannic  acid  consists  of  carbon  51-56  ;  hydrogen  4*20 ;  oxygen  44-24. 

From  the  above  facts  it  is  obvious  that  gallic  acid  does  not  exist  ready  formed  in  gall- 
nuts,  but  that  it  is  produced  by  the  reaction  of  atmospheric  oxygen  upon  the  tannin  of 
these  concretions. 

Gallic  acid  is  a  solid,  feebly  acidulous  and  styptic  to  the  taste^  inodorous,  crystallizing 
in  silky  needles  of  the  greatest  whiteness ;  soluble  in  about  100  times  its  weight  of  col<5 
and  in  a  much  smaller  quantity  of  boiling  water ;  more  soluble  in  alcohol  than  in  water, 
Out  litUe  so  in  sulphuric  ether. 

Gallic  acid  does  not  decompose  the  salts  of  protoxyde  of  iron,  but  it  forms,  with  the 
sulphate  of  the  perotyde,  a  dark  blue  precipitate,  much  less  insoluble  than  the  tannate 
of  iron.     Gallic  acid  takes  the  oxyde  from  the  acetate  and  nitrate  of  lead,  and  throws 


840 


GALL  OF  ANIMALS. 


down  a  white  gallale  unchangeable  in  the  air,  when  it  is  mixed  with  that  acetate  and 
nitrate.  It  occasions  no  precipitate  in  solutions  of  gelatine  (isinglass  or  glue),  by  which 
criteridn  its  fieedom  from  tannin  is  verified. 

Gallic  acid  occurs  but  seldom  in  nature  ;  and  always  united  to  brucine,  veratrine,  or 
lime.  Its  constituents  are  carbon  49-89  ;  hydrogen  3*49 ;  oxygen  46-62.  Li  the  crystal- 
line state  it  conlains  one  atom  of  water,  which  it  loses  by  drying. 

Scheele  obtained  gallic  acid  by  infusing  pounded  galls  for  3  or  4  days  in  8  times  their 
weisht  of  water,  and  exposing  the  infusion  to  the  air,  in  a  vessel  covered  loosely  with 
paper.  At  the  end  of  two  inonihs,  the  liquor  had  almost  all  evaporated,  leaving  some 
mouldiness  mixed  with  a  crystalline  precipitate.  The  former  being  removed,  the  de- 
posite  was  squeezed  in  a  linen  cloth,  and  then  treated  with  boiling  water.  The  solution, 
being  gradually  evaporated,  yielded  crystals  of  gallic  acid,  granular  or  star-like,  of  a 
grayish  color.  These  crystals  might  be  whitened  by  boiling  their  solution  along  with  a 
little  animal  charcoal.  About  one  fifth  of  gallic  acid  may  be  obtained  by  Scheele's  pro- 
cess from  good  gall-nuts. 

From  a  decoction  of  500  parts  of  galls.  Sir  H.  Davy  obtained  185  parts  of  solid  extract ; 
which  consisted  of  130  parts  of  tannin  ;  31  parts  of  gallic  acid  with  extractive;  13  parts 
of  mucilage;  12  parts  of  lime  and  salts.  Hence  gall-nuU  would  seem  to  contain,  by 
this  statement,  more  than  two  thirds  of  their  weight  of  tannin.  This  result  is  now  seen, 
from  the  above  experiments  of  Pelouze,  to  have  been  incorrect,  in  consequence  of  the 
admixture  of  yellow  extractive  in  Davy's  tannin. 

The  use  of  galls  in  many  processes  of  dyeing,  and  in  making  black  ink,  is  detailed 
under  their  respective  heads. 

GALL  OF  ANIMALS,  or  OX-GALL,  purification  of .  Painters  in  water  colors, 
scourers  of  chithes,  and  many  others,  employ  ox-gall  or  bile;  but  when  it  is  not  purified, 
it  is  apt  to  do  harm  from  the  greenness  of  its  own  lint.  It  becomes  therefore  an  impor- 
tant object  to  clarify  it,  and  to  make  it  limpid  and  transparent  like  water.  The  following 
process  has  been  given  fur  that  purpose.  Take  the  gall  of  newly  killed  oxen,  and  after 
having  allowed  it  to  settle  for  12  or  15  hours  in  a  basin,  pour  the  supernatant  liquor  off 
the  sediment  into  an  evaporating  dish  of  stone  ware,  and  expose  it  to  a  boiling  heat  in  a 
water  bath,  till  it  is  somewhat  thick.  Then  spread  it  upon  a  dish,  and  place  it  before  a 
fire  till  it  becomes  nearly  dry.  In  this  state  it  may  be  kept  for  years  in  jelly  pots  cov- 
ered with  paper,  without  undergoing  any  alteration.  When  it  is  to  be  used,  a  piece  of 
it  of  the  size  of  a  pea  is  to  be  dissolved  in  a  table  spoonful  of  water. 

Another  and  probably  a  belter  mode  of  purifying  ox-gall  is  the  following.  To  a  pint 
of  the  gall  boiled  and  skimmed,  add  one  ounce  of  fine  alum  in  powder,  and  leave  the 
mixture  on  the  fire  till  the  alum  be  dissolved.  When  cooled,  pour  into  a  bottle,  which 
is  to  be  loosely  corked.  Now  take  a  like  quantity  of  gall,  also  boiled  and  skimmed,  add 
an  ounce  of  common  salt  to  it,  and  dissolve  with  heat ;  put  it  when  cold  into  a  bottle, 
which  is  likewise  to  be  loosely  corked.  Either  of  these  preparations  may  be  kept  for 
several  years  without  their  emitting  a  bad  smell.  After  remaining  three  months,  at  a 
moderate  temperature,  they  deposite  a  thick  sediment,  and  become  clearer,  and  fit  for 
ordinary  uses,  but  not  for  artists  in  water  colors  and  miniatures,  on  account  of  their 
yellowish-green  color.  To  obviate  this  inconvenience,  each  of  the  above  liquors  is  to 
be  decanted  apart,  after  they  have  become  perfectly  settled,  and  the  clear  portion  of  both 
mixed  together  in  equal  parts.  The  yellow  coloring  matter  still  retained  by  the  mix- 
lure  coagulates  immediately  and  precipitates,  leaving  the  ox-gall  perfectly  purified  and 
colorless^  If  wished  to  be  still  finer,  it  may  be  passed  through  filtering  paper;  but  it 
becomes  clearer  with  age,  and  never  acquires  a  disagreeable  smell,  nor  loses  any  of  its 
good  qualities. 

Clarified  ox-gall  combines  readily  with  coloring  matters  or  pigments,  and  gives  them 
solidity  either  by  being  mixed  with  or  passed  over  them  upon  paper.  It  increases  the 
brilliancy  and  the  durability  of  ultramarine,  carmine,  green,  and  in  general  of  all  delicate 
colors,  whilst  it  contributes  to  make  them  spread  more  evenly  upon  the  paper,  ivory, 
&c.  When  mixed  with  gum-arabic,  it  thickens  the  colors  without  communicating  to 
them  a  disagreeable  glistering  appearance;  it  prevents  the  gum  from  cracking,  and 
fixes  the  colors  so  well  that  others  may  be  applied  over  them  without  degradation. 
Along  with  lamp  black  and  gum,  it  forms  a  good  imitation  of  China  ink.  When  a  coat 
of  ox-gall  is  put  upon  drawings  made  with  black  lead  or  crayons,  the  lines  can  no  longer 
be  effaced^  but  may  be  painted  over  safely  with  a  variety  of  colors  previously  mixed  up 
with  the  same  ox-gall. 

Miniature  painters  find  a  great  advantage  in  employing  it;  bypassing  it  over  ivory, 
it  removes  completely  the  unctuous  matter  from  its  surface;  and  when  ground  with  the 
colors,  it  makes  them  spread  with  the  greatest  ease,  and  renders  them  fast. 

It  serves  also  for  transparencies.  It  is  first  passed  over  the  varnished  or  oiled  paper, 
and  is  allowed  to  dry.  The  colors  mixed  with  the  gall  are  then  applied,  andcannol 
aAerwards  be  removed  by  any  means. 

It  is  adaptedfinally  for  taking"  out  spots  of  grease  and  oil. 


GARNET. 


841 


GALL  OF  GLASS,  called  also  sandiver,  is  the  neutral  salt  skimmed  off  the  surface 
of  melted  crown  glass ;  which,  if  allowed  to  remain  too  long,  is  apt  to  be  reabsorbed 
in  part,  and  to  injure  the  quality  of  the  metal,  as  the  workmen  call  it. 

GALVANIZED  IRON,  is  the  somewhat  fantastic  name  newly  given  in  France  to  iron 
tinned  by  a  peculiar  patent  process,  whereby  it  resists  the  rusting  influence  of  damp 
air,  and  even  moisture,  much  longer  than  ordinary  tin  plate.  The  following  is  the  pre* 
scribed  process.  Clean  the  surface  of  the  iron  perfectly  by  the  joint  action  of  diluto 
acid  and  friction,  plunge  it  into  a  bath  of  melted  zinc,  covered  with  sal-ammoniac,  and 
stir  it  about  till  it  be  alloyed  superficially  with  this  metal ;  when  the  raetal  thus  pre- 
pared is  exposed  to  humidity,  the  zinc  is  said  to  oxidise  slowly  by  a  galvanic  action, 
and  to  protect  the  iron  from  rusting  within  it,  whereby  the  outer  surface  remains  for  a 
long  period  perfectly  white,  in  circumstances  under  which  iron  tinned  in  the  usual  way 
would  have  been  superficially  browned  and  corroded  with  rust. 

G A LVANO- PLASTIC  is  the  German  name  of  Electro-Metallurgy. 

GAMBOGE ;  {Oomme  Chttte,  Fr. ;  Ghitti,  Germ.)  is  a  gum  resin,  concreted  in  the  air, 
from  the  milky  juice  which  exudes  from  several  trees.  The  gamhogia  giUta,  a  tree  which 
grows  wild  upon  the  coasts  of  Ceylon  and  Malabar,  produces  the  coarsest  kind  of  gam- 
boge ;  the  guttcefera  vera  {Stalagmites  camhogioides)  of  Ceylon  and  Siam  affords  the 
best.  It  comes  to  us  in  cylindrical  lumps,  which  are  outwardly  brown  yellow,  but 
reddish  yellow  within,  as  also  in  cakes ;  it  is  opaque,  easily  reducible  to  |>owder  of 
specific  gravity  1-207,  scentless,  and  nearly  devoid  of  taste,  but  leaves  an  acrid  feeling 
in  the  throat.  Its  powder  and  watery  emulsion  are  yellow.  It  consists  of  80  parts  of  a 
hyacinth  red  resin,  soluble  in  alcohol;  and  20  parts  of  gum;  but  by  another  analysis,  of 
89  of  resin,  and  105  of  gum.  Gamboge  is  used  as  a  pigment,  and  in  miniature  painting, 
to  tinge  gold  varnish ;  in  medicine  as  a  powerful  purge.  It  should  never  be  employed 
by  confectioners  to  colour  their  liqueurs,  as  they  sometimes  do. 

GANGUE.  A  word  derived  from  the  German  ga7ig,  a  vein  or  channel.  It  signifies 
the  mineral  substance  which  either  encloses  or  usually  accompanies  any  metallic  ore  in 
the  vein.  Quartz,  lamellar  carbonate  of  lime,  sulphate  of  baryta,  sulphate  and  fluate  of 
lime,  generally  form  the  gangues ;  but  a  great  many  other  substances  become  such  when 
they  predominate  in  a  vein.  In  metallurgic  works  the  first  thing  is  to  break  the  mixed 
ore  into  small  pieces,  in  order  to  separate  the  valuable  from  the  useless  parts,  by  pro- 
cesses called  stamping,  picking,  sorting.     See  Metallurgy  and  Mines. 

GARANCINE,  is  a  dyeing  substance  prepared  from  madder,  called  in  the  French 
language  garance. 

A  patent  was  gianted  in  August,  1843,  to  Mr.  F.  Steiner,  for  the  manufacture  of 
Oarancitie  from  used  madder,  formerly  thrown  away,  as  being  exhausted  of  its  dyeing 

Erinciple.     His   process   is  as  follows:— "A   large   filter  is  constructed  outside   the 
uilding  in  which  the  dye- vessels  are  situated,  formed  by  sinking  a  hole  in  the  ground, 
and  lining  it  at  the  bottom  and  sides  with  bricks  without  any  mortar  to  unite  them. 
A  quantity  of  stones  or  gravel  is  placed  upon  the  bricks,  and  over  the  stones  or  gravel 
common  wrappering,  such  as  is  used   for  sacks.     Below  the   bricks  is  a  drain  to  take 
off  the  water  which  passes  through  the  filter.    In  a  tub  adjoining  the  filter  is  kept  a 
quantity  of  dilute  sulphuric  acid,  of  about  the  specific  gravity  of  105,  water  being  100. 
Hydrochloric  acid  will  answer  the  several  purposes,  but  sulplmric  acid  is  preferred  n» 
more  economical.    A  channel  is  made  from  the  dye- vessels  to  the  filter.    The  madder 
which  has  been   employed   in   dyeing  is  run  from  the  dye- vessels  to  the  filter-   and 
while  it  is  so  running,  such  a  portion  of  the  dilute  sulphuric  acid  is  run  in  and  mixed 
with  it  as  changes  the  colour  of  the  solution  and  the  undissolved  madder  to  an  orange 
tint  or  hue.     This  acid  precipitates  the  colouring  matter  which  is  held  in  solution,  and 
prevents  the  undissolved  madder  from  fermenting  or  otherwise  decomposino-.      When 
the  water  has  drained  from  the  madder  through  the  filter,  the  residuum  is  taken  from 
off  the  filter  and  put  into  bags.     The  bags  are  then  placed  in  an  hydraulic  press,  to  have 
as  much  water  as  possible  expressed  from  their  contents.     In  order  to  break  the  lumps 
which  have  been  formed  by  compression,  the  madder  or  residuum  is  passed  through  a 
sieve.    To  5  cwt.  of  madder  in  this  state,  placed  in  a  wood  or  lead  cistern,  1  cwt  of 
sulphuric  acid  of  commerce  is  sprinkled  on  the  madder  through  a  lead  vessel  similar 
in  form  to  the  ordinary  watering-can  used  by  gardeners.    An  instrument  like  a  garden 
spade  or  rake  is  next  used,  to  work  the  madder  about,  so  as  to  mix  it  intimately  with 
the  acid.     In  this  stage  the  madder  is  placed  upon  a  perforated  lead  plate,  which  is 
fixed  about  five  or  six  inches  above  the  bottom  of  a  vessel.    Between  this  plate  and 
the  bottom  of  the  vessel  is  introduced  a  current  of  steam  by  a  pipe,  so  that  it  passes 
through  the  perforated  plate  and  the  madder  which  is  upon  it.     During  this  process, 
which  occupies  from  one  to  two  hours,  a  substance  is  produced  of  a  dark  brown  colour 
approaching  to   black.     This    substance  is   garancine  and  insoluble  carbonized  matter. 
Wijen  cool,  it  is  placed  upon  a  filter  and  washed  with  clear  cold  water  until  the  water 


S42 


GAS. 


I 

If 


passes  from  it  without  an  add  taste.  It  is  then  put  into  hags  and  pressed  with  an 
n)»draulic  press.  The  substance  is  dried  in  a  stove  and  ground  to  a  fine  powder  under 
ordinary  madder  stones,  and  afterwards  passed  through  a  sieve.  In  order  to  neutralize 
any  acid  that  may  remain,  from  4  to  5  lbs.  of  dry  carbonate  of  soda  for  every  hundred 
weight  of  tliis  substance  is  added  and  intimately  mixed.  The  garancine  in  tliis  state  is 
ready  {or  use." 

GARNET  {Grenat,  Fr. ;  Granat,  Germ.);  is  a  vitreous  mineral  of  the  cubic  system, 
of  which  the  predominating  forms  are  the  rhomboidal  dodecahedron  and  the  trapaezo- 
hedron ;  specific  gravity  varying  from  3-35  to  4-24 ;  fusible  at  the  blowpipe.  Its  con- 
stituents are,  silica,  42  ;  alumina,  200  ;  lime,  340;  protoxide  of  iron,  4.  Garnets  are 
usually  disseminated,  and  occur  in  all  the  primitive  strata  from  gneiss  to  clay  slate. 
The  finer  varieties,  noble  garnet  or  Almandine,  and  the  reddish  varieties  of  Grossulaire 
(Essonite),  are  employed  in  jewelry ;  the  first  are  called  the  Syrian  or  oriental ;  the 
others,  hyacinth.  In  some  parts  of  Germany  garnets  are  so  abundant  as  to  be  used 
as  fluxes  to  some  iron  ores :  in  others,  the  garnet  gravel  is  washed,  pounded,  and  em- 
{)loyed  as  a  substitute  for  emery.  The  garnets  of  Jfegu  are  most  highly  valued.  Fac- 
titious garnets  may  be  made  by  the  following  composition :— Purest  while  glass,  2 
ounces ;  glass  of  antimony,  1  ounce ;  powder  of  cassius,  1  grain ;   manganese,  1  grain. 

GAULTHERIA  OIL;  an  aromatic  oil,  called  in  commerce  wintergreen  oil.  It 
is  obtained  from  a  shrub  of  the  Ericeen  family,  {Qaultheria  procumbens  L,  Canadian  tea.) 
The  oil  occurs  in  all  parts  of  the  plant,  but  mostly  in  the  flowers,  and  may  be  extracted 
by  alcohol,  but  not  by  water  from  the  dried  or  scentless  plant.  The  same  oil  is  obtained 
from  the  bark  of  sweet  birch,  by  distilling  it  with  water,  whereby  it  results  from  the 
mutual  action  of  a  body  like  emulsion  upon  a  body  like  amygdalin.  The  oil  is  colourless, 
but  becomes  reddish  in  the  air,  as  it  is  found  in  commerce.  Its  specific  gravity  is  1-173, 
and  its  boiling  point  211°  C. ;  it  distils  at  the  constant  heat  of  220°;  it  has  then  a 
gravity  1-18:  the  watery  solution  of  the  oil  produces  with  the  red  salts  of  iron  a  violet 
tint,  which  becomes  with  excess  of  oil  very  deep  and  rich.    Its  constituents  are 

C„  =  1200  63-16 

Ha  =     100  5-26 

O.   =     600  31-58 


1900 


100-00 


If  we  distil  the  oil  with  an  excess  of  caustic  potash,  wood  spirit  comes  over,  and  the 
renaainder  consists  of  salicylate  of  potash.  The  oil  is  a  natural  compound  wood  ether, 
which  may  be  prepared  artificially  by  distilling  together  two  parts  of  salicylic  acid 
with  two  parts  of  dry  wood  spirit,  and  one  part  of  oil  of  vitriol.  The  ether  is  separable 
from  the  distilled  liquor  by  means  of  chlorcalcium.  Bromine  and  chlorine  act  violently 
upon  the  oil.  The  gaultheria  oil  combines  without  decomposition  into  a  peculiar  class 
of  salts. 

GAULTHERINE.  When  the  pulverized  dried  bark  of  hetula  lenta  is  exhausted 
with  cold  alcohol  of  95°,  it  can  afford  no  more  oil  The  fluid  which  contains  the 
gaultherine  has  a  slight  bitterish  taste,  and  by  evaporation  it  forms  a  dry  gummy  mass, 
which  at  a  high  heat  leaves  a  coaly  residual. 

Oil  of  vitriol  dissolves  the  gaultherine  with  a  red  colour  and  a  flavour  of  the  oil. 

GAS  (Eng.  and  Fr.;  Gaz,  Germ.)  is  the  generic  name  of  all  those  elastic  fluids  which 
are  permanent  under  a  considerable  pressure,  and  at  the  temperature  of  zero  of  Fahren- 
heit. In  many  of  them,  however,  by  the  joint  influence  of  excessive  cold  and  pressure, 
the  repulsive  stale  of  the  particles  may  be  balanced  or  subverted,  so  as  to  transform  the 
elastic  ^as  into  a  liquid  or  a  solid.  For  this  most  interesting  discover}-,  we  are  indebted 
to  the  fine  genius  of  Mr.  Faraday. 

The  following  table  exhibits  the  temperatures  and  pressures  at  which  certain  gases  are 
liquefied. 


Name  of  the  gas. 

Becomen  liquid 

Calculated  boiling  point ; 
fiaroni.  =  30  inches. 

At 

Under  a  pressure  of 

Sulphurous  acid 

Chlorine 

Ammonia          _            -            - 

Sulphureted  hydrogen    - 

Carbonic  acid    -            -            - 

Hydrochloric  or  muriatic  acid    - 

Deutoxide  of  azote 

59°  F. 

60 

50 

50 

32 

50 

45 

3  atmospheres. 

4 

6-5 
17 
36 
50 
50 

—  4°  Fahr. 
-•  22 

—  64 

—  142 

—  229 

—  249 
~  254 

GAS-LIGHT. 


843 


) 


i 


Liquid  carbonic  acid  becomes  solidified,  into  a  snowy-looking  substance,  by  its  own 
rapid  evaporation.  Oxygen,  hydrogen,  and  azote,  have  hitherto  resisted  all  attempts  to 
divest  them  of  their  elastic  form.  For  this  purpose,  it  is  probable  that  a  condensing  force 
equal  to  that  of  650  atmospheres,  will  be  required. 

The  volume  of  aoy  gas  is,  generally  speaking,  inversely  as  the  pressure  to  which  it  is 
exposed  ;  thus,  under  a  double  pressure  its  bulk  becomes  one  half;  under  a  triple  pres- 
sure, one  third ;  and  so  on.  For  the  change  of  volume  in  gaseous  bodies  by  heat,  see 
Expansion. 

Ammonia,  carbonic  acid,  carbureted  hydrogen,  chlorine,  muriatic  acid,  sulphurous 
acid,  sulphureted  hydrogen,  are  the  gases  of  most  direct  interest  in  the  arts  aoH  manu* 
factures.     Their  detailed  examination  belongs  to  a  work  on  chemistry. 

GAS-LIGHT.  (Eclairage  par  gas,  Fr. ;  GasHcht,  Germ.)  Dr.  Clayton  iemon- 
strated,  by  numerous  experiments  in  1737  and  1738,  that  bituminous  pit-coal  subjected  to 
a  red  heat  in  close  vessels,  afforded  a  great  deal  of  an  air  simJar  to  the  fire-damp  of 
mines,  but  which  burned  with  a  brighter  flame.  It  does  not  appear  that  this  species 
of  factitious  air  was  ever  produced  from  pit-coal  for  the  purpose  of  artificial  illumination 
till  1792,  when  Mr.  William  Murdoch,  engineer  to  Messrs.  Bolton  and  Walt,  employed 
^^al  gas  for  lighting  his  house  and  offices,  at  Redruth  in  Cornwall.  The  gas  was  gen- 
erated in  an  iron  retort,  whence  it  was  received  in  a  gasometer,  distributed  in  diflfer- 
ent  situations  by  pipes,  and  finally  burned  at  small  apertures  which  could  be  opened 
and  stopped  at  pleasure.  He  moreover  made  this  light  moveable,  by  confining  the  gas 
in  portable  tin-plate  vessels,  and  burning  it  wherever  he  pleased.  Between  this  period 
and  1802,  Mr.  Murdoch  continued  at  intervals  to  make  similar  experimer.ts ;  and 
upon  occasion  of  the  national  illumination  in  the  spring  of  the  latter  year,  at  the 
peace  of  Amiens,  he  lighted  up  part  of  the  Soho  manufactory  with  a  public  display  of  gas- 
lights. 

The  earliest  application  of  this  artificial  light,  on  a  large  systematic  scale,  was  made 
at  Manchester ;  where  an  apparatus  for  lighting  the  great  cotton  mills  of  Messrs. 
Philips  and  Lee,  was  fitted  up  in  1804  and  1805,  under  the  direction  of  Mr.  Murdoch. 
A  quantity  of  light,  nearly  equal  to  3000  candles,  was  produced  and  distributed  in  this 
building.  This  splendid  pattern  has  been  since  followed  very  generally  in  Great  Britain, 
and  more  or  less  in  many  parts  of  the  continents  of  Europe  and  America.  By  the  yeai 
1822,  8:as-lighting  in  London  had  become  the  business  of  many  public  companies.  At 
the  Peter  street  station,  for  example,  300  retorts  had  been  erected,  supplying  15  gasome- 
ters, having  each  an  average  capacity  of  20-626  cubic  feet,  but,  being  never  quite  filled, 
their  total  contents  in  gas  might  be  estimated  at  309,385  cubic  feet.  The  extent  of  main 
pipes  of  distribution  belonging  to  this  station  was  then  about  57  miles,  with  two  separate 
mains  in  some  of  the  streets.  The  product  of  gas  was  from  10,000  to  12,000  cubic  feet 
from  a  chaldron  of  coals.  The  annual  consumption  of  coals  was  therefore  altogether  9282 
chaldrons,  aff'ording  11,384,000  cubic  feet  of  gas,  allowing  153  retorts  to  be  in  constant 
daily  action,  upon  an  average  of  the  year;  and  illuminating  10,660  private  lamps,  2248 
street  lamps,  and  3894  theatre  lamps. 

At  the  Brick-lane  works,  371  retorts  were  fixed  in  1822,  133  being  worked  on  an  aver 
age  of  summer  and  winter.     There  were  12  gasometers,  charged  with  an  average  quantity 
of  gas  amounting  to  197,214  cubic  feet.     Of  coals,  8060  chaldrons  were  annually  con- 
sumed ;  96,720,000  cubic  feet  of  gas  were  generated  ;  for  the  supply  of  1978  public  lamps, 
and  7366  private  ones,  connected  with  main  pipes  40  miles  long. 

At  the  Curtain-road  gas  establishment,  there  were  240  retorts ;  but  the  greatest  number 
worked  in  1821  was  only  80,  and  the  lowest  21.  The  six  gasometers  had  an  average 
contents  of  90,467  cubic  feet.  Of  coals,  3336  chaldrons  were  annually  consumed,  yield- 
ing 40,040,000  cubic  feet  of  gas,  that  supplied  3860  private  lamps,  and  629  public  ones, 
by  means  of  mains  25  miles  long.  The  above  three  stations  belonged  to  the  London  Gas- 
Lisht  and  Coke  Company. 

The  City  of  London  Gas-Light  Company,  Dorset  street,  had  built  up  230  retorts,  and 
6  gasometers,  while  two  were  preparing;  having  a  total  capacity  of  181,282  cubic  feet. 
Of  private  lamps  5423  were  lighted,  and  2413  public  ones,  from  mains  extending  50  miles. 
The  quantify  of  coals  carbonized  amounted  to  8840  chaldrons ;  producing  106,080,000 
cubic  feet  of  eas. 

The  South  London  Gas-Light  and  Coke  Company  had  mounted  at  Bankside  143  retorts, 
with  3  gasometers;  the  contents  of  the  whole  being  41,110  cubic  feet,  connected  with 
mains  from  30  to  40  miles  long.  At  their  other  station,  in  Wellington  street,  9  large 
gasometers  were  then  erecting,  with  a  capacity  of  73,565  cubic  feet,  which  were  to  be 
supplied  with  gas  from  Bankside,  till  retorts  were  mounted  for  them. 

The  Imperial  Gas-Light  and  Coke  Company  had  at  that  lime  6  gasometers  in  progresi 
at  their  Hackney  station. 

In  1822  there  were  thus  four  great  companies,  having  in  all  47  gasometers  at  work, 
capable  of  containing  917,940  cubic  feet  of  gas,  supplied  by  1315  retorts,  which  generated 


844 


GAS-LIGHT. 


Tlfis"'!^  "'"''^^''''.'^P^^'^^^'T'f '^/"^^"^S^^^'^y  ^^»*=^  «''203  private  lan,|»,and 
7268  public  or  street  lamps,  were  huhted  in  the  metropolis.  Besides  these  publircom- 
panies,  tliere  were  likewise  several  private  ones. 

1.  Of  the  genera/iou  of  illuminating  gam.— Pure  hydrogen  gas  bums  with  too  feeble 
a  flame  lo  be  employed  lor  illumination.  But  carbureted  hydrogen  having  the  property 
of  prec.p.tat.ng  its  carbon  in  the  act  of  burning,  its  solid  particles  become  incandescenL 
and  diiiuse  a  v.vid  light.  The  more  carbon  it  contains,  the  more  brightly  does  it  burn. 
This  gas  exists  in  two  distinct  stales  of  combination.  In  the  first,  two  measures  of  hy- 
drosen  gas  are  combined  with  one  measure  of  the  vapor  of  carbon,  forming  together  one 
TnTJ^  !''^  specific  gravity  is  of  course  the  sum  of  the  weights  of  the  constituents, 
?.  lo  J  f "",^f»»^^^'-'f  ^  a/  being  1000.  This  is  the  gas  which  is  found  in  mines,  and 
L.  r  h  J  '"  '^'"^^'  ^'''"'  .decomposing  vegetable  matter.  In  the  second,  two  meas- 
ures  ol  hydrogen  gas  are  combined  with  two  of  gaseous  carbon,  forming  also  one  volume 
or  measure  whose  weight  or  specific  gravity  is  0-985.     This  was  at  one  time  called  the 

?r  .n»v  iJ^^'n "T"'^  'n^^?l  °''''^^  "^'^^  ^*^'°''"^  *"  «^'y  ^o«^'"«  compound  was  produced. 
It  may  be  called  as  well  oil  gas,  because  it  is  generated  in  considerable  quantities  by  the 

trnn:  irT^'^K*"  °^r^"-     '^^'"^  '^^  "'^^^"^  ?^^  ^«»^*'"^  •»  ^h«  same  volume  double 
ablv  br^"  ;  erl/r^I      Th  '°"'"'^"  carbureted  hydrogen,  and  it  burns  with  a  proportion- 
ably  brighter  flame.     The  gaseous  oxyde  of  carbon,  as  well  as  sulphureted  hydro-en  gas 
burns  with  a  feeb  e  blue  light,  but  the  latter  produces  in  combustion  su  phuroUs  add,^an 
oflensive  and  noxious  gas.  ^  ' 

origin '^i:  ^^'^"'^^•^"  ^^  carbonization  in  close  vessels,  all  bodies  of  vegetable  and  animal 
ZSnot  L^ut!.^  carbureted  hydrogen  gas;  even  charcoal,  when  placed  in  ignition  in 
carT,?p.pH  hv]  '  ^y  '^^^^'^P^S'"?  the  water,  produces  abundance  of  carbonic  acid, 
Zh  Zy*  T'  ^y?-"*?^"'  '^"^  ^^^••^"^c  «^yde.  After  separating  the  carbrmic  acid 
ThlrlTl         k'       '  ""'""'i  gas  contains  in  100  measures,  20  of  carbureted  hydrogen  ; 

arp  nZ^i  -^  '^  ^u'^  substances  for  furnishing  a  gas  rich  in  luminiferous  materials 

are  p  tcoal,  especia  ly  the  cannel  coal,  resin,  oU,  fats  of  all  kinds,  tar,  wax,  &c.  In  some 
cases  the  gases  evolved  during  the  igneous  decomposition  of  bones  and  other  animal  mat- 

ipt  to  emk  aTtid  oZ.      ^'"°''"'''  "^^  ^'  '""^^"^'^  ^"'  ^'"'"""^  ^'^^'^'  ^"'  '^'^  ^^^^ 

is  ^'I^.nowf  f'  ^'^'ilV  T.^''"''''  '^^u'^  ^°  ^^"'^'°"'  ^^^  P''^?''^^^  «^  decomposition 
IS  as  lo  lows.     First  and  before  the  retort  becomes  red  hot,  steam  issues  along  with  the 

atmospheric  air.  When  the  retort  begins  to  redden,  tar  distils  in  consi.lerable  quantity 
with  some  combustible  gas,  of  which  hydrogen  mixed  with  ammoniacal  gas  forms  a  part. 
The  evolution  of  gas  increases  as  the  retort  becomes  hotter,  with  a  continual  production 
nnif  «  wl^^h^Jr"'^''  i'quoras  well  as  sulphurous  acid  from  the  pyrites  of  the  coal,  which 
unites  with  the  ammonia.     When  the  retort  has  come  to  a  bright  cherry  red  heat   the 

eTntZrclli  "-.- --t -tlve.  By  and  by  the  gaseous  product!:>7Jiminishi\'nd 
eventually  ceases  entirely,  although  the  heat  be  increased.  In  the  retort  a  quantity  of 
carbonized  coal  or  coke  .emains  while  tar  is  found  at  the  bottom  of  the  receiver,  covered 
phureted  rdTori!""^  '*""'"'  combined  with  carbonic  and  sulphurous  acids,  and  sul. 
^PvLI"'!"'    ^h's^«sti»ation,  the  combustible   gas  be  collected  and  examined  at   the 

That  lb  cTL  '^T^.T'  V.'  ^"""^  '?  '^''^''  '""'''"^'^y  ^'^  '''  ^"'"iniferous  powers. 
Iha    which  comes  ofl    before  the  retort  has  acquired  its  proper  temperature  gives  a 

%tlf\:  r^  ''^"^'1,"'  '^'  gas  obtained  by  the  ignition  of  m'oist  chaCrcons  s  fng 

red  heat  is'thT";  7^u'  ''°^''^  ^'t"  '^'  T''  ^^'  ^"^^  «^^"'^^^'  throughout  a  vivid 
Frnm  tn  1  ,  ^"^'^  ""^  ^"'  *^«"«'^t'"^  "^^'^^V  ^^  bi-carburctcd  hydrogen  or  olefiant  gas. 
:  K  ^?Au''f'  '^  consists,  for  example,  in  100  measures,  of  13  of  olefiant  gas,  82-5  of 
TrtlT'^  A^i^T?'  ^'^  .^^••bonic  oxyde,  1-3  azote;  the  mixture  having  a  specmi  gravity 
of  K  .i  K  'f'''  P^'"'"'^' «s  after  5  hours,  it  contains  7  measures  of  olefiant  gas,  56 
of  carbureted  hydrogen,  11  of  carbonic  oxyde,  21-3  of  hydrogen,  47  of  azote;  the  tn'ec^ 
fie  gravity  of  the  whole  being  0-500.  Towards  the  end  of  the%peration,  as  aft;r  10  hour  , 
,t  contains  twenty  measures  of  carbureted  hydrogen,  10  of  carbonic  oxyde,  60  of  hydros 
gen  10  of  azote  with  a  specific  gravity  of  only  0-345.  The  hydrogen  becomes  sulphur- 
eted  hydrogen,  if  there  be  much  pyrilous  matter  in  the  coal.     The  larger  proportion  of 

^l  T  '''^\r-.^^'t  "!:  '5'  ^■"'^  ^*^"'''  ^'"^""lin?  to  about  one  fiAh  of  the  whole ;  in 
the  three  fulluw.ng  hours  the  disengagement  is  tolerably  uniform,  constituting  in  all  fifty- 

""hltedtiis!"  ^'^  ^"^'  »^-r,aisone  tenth;  in  the  seyenth  and  efghth  hour^s, 
From  these  observations  are  derived  the  rules  for  the  production  of  a  good  light  gas 

ZlTt":  I^"^  '^?'''''^''  Ik'  t'*""^r  ^^""^^  ^«™^^"^«  ^ith  a  retort  preiiou^sly 
heaed  loa  cherry  red,  since   thereby  good  gas  is  immediately  produced,  and  a  portioj 

Sine.  •/'  !i''*.T''''u^'^  '"l""  gas  instead  of  being  simply  distilled  over  into  the  con- 
frn T^  r  «  K  ^  K  ^^^^  u^'^I'J**  ^^  u^^^^'^y  continued  during  the  whole  opeiation, 
trom  6  lo  8  hours;  that  it  should  not  be  increased,  especially  towards  the  end,  for  feax 


GAS-LIGHT. 


845 


of  generating  carbonic  ox/de  and  hydrogen  gases,  as  well  as  of  injuring  the  retort  when 
the  cooling  agency  of  gaseficaiion  has  become  feeble;  and  that  the  operation  should  be 
stopped  some  time  before  gas  ceases  to  come  over,  lest  gases  with  feeble  illuminating  power 
should  impoverish  the  contents  of  the  gasometer.  Upon  the  average,  a  pound  of  good  coai 
atfords  four  cubic  feet  of  gas,  or  a  chaldion=26  cwts.  London  measure,  jifTords  from  12,000 
lo  15,000  cubic  feet,  according  to  the  form  of  the  retort,  and  the  manner  of  firing  it. 

When  oil,  fats,  rosin,  tar,  &c.  are  employed  for  the  production  of  a  light  gas,  it  is  not 
sufficient  to  introduce  these  substances  into  the  retorts,  and  to  heat  them,  as  is  done 
with  coals.  In  this  case,  the  greater  part  of  them  would  distil  over  in  the  state  of  vola- 
tile oils,  and  very  little  gas  be  generated,  only  as  much  as  corresponded  to  the  quantity 
of  fat,  &.C.  in. immediate  contact  wit^  the  retort.  It  becomes  therefore  necessary  to 
fill  the  retorts  with  pieces  of  brick  or  coke ;  and  to  keep  them  in  ignition,  while  the 
oil,  &c.  is  slowly  introduced  into  their  interior.  The  fats  instantly  assume  the  vaporous 
stale,  and  thus  coming  into  contact  upon  an  extensive  surface  with  Ihe  ignited  bricks, 
are  decomposed  into  combustible  gases.  A  small  portion  of  carbonaceous  matter  re- 
mains in  the  retort,  while  much  olefiant  gas  is  formed,  possessing  a  superior  illumi- 
nating power  lo  common  coal  gas,  and  entirely  free  from  sulphureous  impregnation. 
The  best  oil  gas  is  generated  at  a  dull  red,  a  heal  much  below  what  is  requisite  for  the 
decomposition  of  coal.  A  more  intense  heat  would  indeed  produce  a  greater  volume 
of  gas,  but  of  a  poorer  quality,  because  the  olefiant  gas  thereby  deposites  one  half  of 
its  carbon,  and  is  converted  into  common  carbureted  hydrogen.  Oil  affords  at  a  lively 
red  heat,  gases  which  contain  in  100  measures,  19  of  olefiant  gas,  32-4  of  carbureted 
hydrogen,  122  of  carbonic  oxyde  gas,  32-4  of  hydrogen,  and  4  of  azote;  the  mean  specific 
gravity  being  only  0-590.  At  a  more  moderate  temperature  it  yields  22-5  of  the 
olefiant,  50-3  carbureted  hydrogen,  15-5  carbonic  oxyde,  7-7  hydrogen,  and  4  azote, 
with  a  specific  gravity  of  0*758.  It  contains  when  generated  by  dull  ignition,  as  is 
usual  in  works  on  the  manufacturing  scale,  in  100  parts  from  38  to  40  of  olefiant  gas, 
and  besides  the  carbureted  hydrogen,  a  few  per  cent,  of  carbonic  oxyde  and  azote, 
with  a  specific  gravity  of  0-900,  and  even  upwards.  One  pound  of  oil  or  fluid  fat  aflfords 
15  cubic  feet  of  gas ;  of  tar  afibrds  about  12  cubic  feet ;  of  rosin  or  pitch,  10  cubic  feet. 

When  the  oil  gas  is  compressed  by  a  force  of  from  15  to  20  atmospheres,  as  was  the 
practice  of  the  Portable  Gas  Company,  about  one  fifth  of  the  volume  of  the  gas  becomes 
liquefied  into  an  oily,  very  volatile  fluid,  having  the  specific  gravity  0-821.  It  is  a 
mixture  of  three  fluids  (consisting  of  carbureted  hydrogen),  of  different  degrees  of 
volatility.  The  most  volatile  of  these  boils  even  under  32"  F.  Some  of  the  vapor  of 
this  gas-oil  is  mixed  with  the  olefiant  gas  in  the  general  products  of  decomposition;  in 
consequence  of  which  they  are  sometimes  richer  in  carbon  than  even  olefiant  gas,  and 
have  a  higher  illuminating  power.  Oil  gas  contains  about  22  per  cent,  and  coal  gas 
about  3 J  per  cent,  of  this  oily  vapor.  In  the  estimations  of  the  composition  of  the 
gases  given  above,  this  vapor  is  included  under  olefiant  gas.  This  vapor  combines 
readily  with  sulphuric  acid,  and  is  thus  precipitated  from  the  gaseous  mixture.  The 
amount  of  olefiant  gas  is  shown,  by  adding  to  the  gas,  contained  over  water,  one  half  of 
its  volume  of  chlorine,  which,  in  the  course  of  an  hour  or  two,  condenses  the  olefiant  gas 
into  an  oily  looking  liquid  (chloride  of  hydrocarbon.)  After  the  mixture,  the  gases 
must  be  screened  from  the  light,  otherwise  the  common  carbureted  hydrogen  would  also 
combine  with  the  chlorine,  while  water  and  carbonic  acid  would  make  their  appearance. 

The  oil  employed  for  aflfdrding  gas  is  the  crudest  and  cheapest  that  can  be  bought ;  even 
the  blubber  and  sediment  of  whale  oil  are  employed  with  advantage.  After  all,  however, 
coal  is  so  much  cheaper,  and  the  gas  produced  from  it  is  now  so  well  purified,  that  oil 
and  rosin  are  very  little  used  in  gas  apparatus. 

Apparatus  for  Coal  Gas. — Coal  gas,  as  it  issues  from  the  retort,  cannot  be  directly 
employed  for  illumination ;  for  it  contains  vapors  of  tar  and  coal  oil,  as  also  steam 
impregnated  with  the  carbonate,  sulphite,  and  hydrosulphuret  of  ammonia.  These 
vapors  would  readily  condense  in  the  pipes  through  which  the  gas  must  be  dis- 
tributed, and  would  produce  obstructions  ;  they  must  therefore  be  so  far  removed  by 
previous  cooling,  as  to  be  liable  to  occasion  no  troublesome  condensation  at  ordinary 
temperatures.  The  crude  coal  gas  contains  moreover  sulphureted  hydrogen,  whose  com- 
bustion for  light  would  exhale  an  oflTensive  sulphureous  odor,  that  ought  to  be  got 
rid  of  as  much  as  possible.  Carbonic  acid  and  carbonic  oxyde  gases,  generated  at  first 
from  the  decomposition  of  the  steam  by  the  ignited  coal,  enfeeble  the  illuminating  power 
of  the  gas,  and  should  be  removed.  The  disengagement  of  gas  in  the  retorls  is  never 
uniform,  but  varies  with  the  degree  of  heal  lo  which  they  are  exposed;  for  which 
reason  the  gas  must  be  received  in  a  gasometer,  where  it  may  experience  uniform  pres- 
sure, and  be  discharged  uniformly  into  the  pipes  of  distribution,  in  order  to  ensure  a 
steady  discharge  of  gas,  and  uniform  intensity  of  light  in  the  burners.  A  coal  gas  appa- 
ratus ought  therefore  to  be  so  constructed  as  not  only  to  generate  the  gas  itself,  but  to  fiUfil 
the  above  conditions. 


846 


GAS-LIGHT. 


1/ 


^f 


In^^.  669,  such  an  apparatus  is  represented,  where  the  various  parts  are  shown  coft 
mected  with  each  other,  in  section. 

A  is  the  furnace  with  its  set  of  cylindrical  or  elliptical  retorts,  five  in  number.     From 
each  of  these  retorts,  a  tube  b  proceeds  perpendicularly  upwards,  and  then  by  a  curvt 

or  saddle-tube,  it  turns  down 
wards,  where  it  enters  a  long 
horizontal  cylinder  under  b,  shut 
at  each  end  with  a  screw  cap,  and 
descends  to  beneath  its  middle, 
so  as  to  dip  about  an  inch  into 
the  water  contained  in  it.  From 
one  end  of  this  cylinder  the  tube 
d  passes  downward,  to  connect 
itself  with  a  horizontal  tube 
which  enters  into  the  tar  pit  or 
cistern  c,  by  means  of  the  verti 
cal  branch/.  This  branch  reach 
es  to  near  the  bottom  of  the  cy- 
lindrical vessel,  which  sits  on  the 
sole  of  the  tar  cistern.  From  the 
other  side  of  the  vertical  branch 
/,  the  main  pipe  proceeds  to  the 
condenser  d,  and  thence  by  the 
pipe  /,  into  the  purifier  e  ;  from 
which  the  gas  is  immediately 
transmitted  by  the  pipe  p  into  the 
gasometer  f. 

The  operation  proceeds  in  the 
following  way : — As  soon  as  gas 
begins  to  be  disengaged  from  the 
ignited  retort,  tar  and  ammoni- 
acal  liquor  are  deposited  in  the 
cylindrical  receiver  b,  and  fill  it 
up  till  the  superfluity  runs  over 
by  the  piperf,  the  level  being  con- 
stantly preserved  at  the  line 
shown  in  the  figure.  By  the  same 
tarry  liquid,  the  orifices  of  the 
several  pipes  ft,  issuing  from  the 
retorts,  are  closed  ;  whereby  the 
gas  in  the  pipe  d  has  its  com- 
munication cut  off  with  the  gas 
in  the  retorts.  Hence  if  one  of 
the  retorts  be  opened  and  emp- 
tied, it  remains  shut  oflTfrom  the 
rest  of  the  apparatus.  This  in- 
sulation of  the  several  retorts  is 
the  function  of  the  pipe  under  b, 
and  therefore  the  recurved  tubed 
must  be  dipped  .ns  far  under  the 
surface  of  the  tarry  liquid,  as  to 
be  in  equilibrio  with  the  pressure 
of  the  gas  upon  the  water  in  the 
purifier.  The  tube  b  is  closed  at 
top  with  a  screw  cap,  which  can 
be  taken  off  at  pleasure,  to  per- 
mit the  interior  to  be  cleansed. 

Both  by  the  overflow  from  the 
receiver-pipe  b,'  and  by  subse- 
quent condensation  in  the  tube  i,  tar  and  ammoniacal  liquor  collect  prosressively  in  the 
cistern  or  pit  under  c,  by  which  mingled  liquids  the  lower  orifice  of  the  vertical  tube/  is 
closed,  130  that  the  gas  cannot  escape  into  the  empty  space  of  this  cistern.  These  liquids 
flow  over  the  edges  of  the  inner  vessel  when  it  is  full,  and  may  from  time  to  lime  be 
drawn  oflT  by  the  stopcock  at  the  bottom  of  the  cistern. 

Though  the  gas  has,  in  its  progress  hitherto,  deposited  a  good  deal  of  its  tarry  and 
ammoniacal  vapors,  yet,  in  consequence  of  its  high  temperature,  it  still  retains  a  con- 
siderable portion  of  them,  which  must  be  immediately  abstracted,  otherwise  the  tar 


GAS-LIGHT. 


847 


would  pollute  the  lime  in  the  vessel  e,  and  interfere  with  its  purification.  On  this  ac 
count  the  gas  should,  at  this  period  of  the  process,  be  cooled  as  much  as  possible,  in  order 
to  condense  these  vapors,  and  to  favor  the  action  of  the  lime  in  the  purifier  e,  upon  the 
sulphureled  hydrogen,  which  is  more  energetic  the  lower  the  temperature  of  the  gas. 
The  c(»al  gas  passes,  therefore,  from  the  tube  /  into  the  tube  h  of  the  condenser  d,  which 
is  placed  in  an  iron  chest  g  filled  with  water,  and  it  deiK>sites  more  tar  and  ammoniacal 
liquor  in  the  under  part  of  the  cistern  at  t,  I.  When  these  liquids  have  risen  to  a  certain 
level,  they  overflow  into  the  tar-pii,  as  shown  in  the  figure,  to  be  drawn  oflf  by  the  stop- 
cock as  occasion  may  require. 

The  refrigerated  gas  is  now  conducted  into  the  purifier  e,  which  is  filled  with  milk  of 
lime,  made  by  mixing  one  part  of  slaked  lime  with  25  parts  of  water.  The  gas,  as  it 
enters  by  the  pipe  /,  depresses  the  water  in  the  wide  cylinder  n,  thence  passes  under  the 
perforated  disc  in  the  under  part  of  that  cylinder,  and  rising  up  througli  innumerable 
small  holes  is  distributed  throughout  the  lime  liquid  in  the  vessel  m.  By  contact  with 
the  lime  on  this  extended  surface,  the  gas  is  stripped  of  its  sulphureted  hydrogen  and 
carbonic  acid,  which  are  condensed  into  the  hydro-sulphuret  and  carbonate  of  lime ;  it  now 
enters  the  gasometer  f  in  a  purified  state,  through  the  pipep  t,  and  occupies  the  space  q. 
The  gasometer,  pressing  with  a  small  unbalanced  force  over  the  counterweight  «,  expels 
it  through  the  main  u  u,  in  communication  with  the  pipes  of  distribution  through  the 
buildings  or  streets  to  be  illuminated. 

The  parts  abode  and  f,  of  which  this  apparatus  consists,  are  essential  constituents 
of  every  good  coal-gas  work.  Their  construction  rests  upon  peculiar  principles,  is  sus- 
ceptible of  certain  modifications,  and  therefore  deserves  to  be  considered  in  detail. 

The  Retorts.  —  These  are  generally  made  of  cast  iron,  though  they  have  occasionally 
been  made  of  baked  clay,  like  common  earthenware  retorts.  The  original  form  was  a 
cylinder,  which  was  changed  to  an  ellipse,  with  the  long  axis  in  a  horizontal  direction, 
then  into  the  shape  of  the  letter  d  with  the  straight  line  undermost,  and  lastly  into  a 
semi-cylinder,  with  its  horizontal  diameter  22  inches,  and  its  vertical  varying  from  9  to 
12.  The  kidney  form  was  at  one  time  preferred,  but  it  has  been  little  used  of  late. 
The  form  of  retort  represented  in  Jig.  670  has  been  found  to  yield  the  largest  quantity 

of  good  gas  in  the  shortest  time,  and  with 
the  least  quantity  of  firing.  The  length  is 
7|,  and  the  transverse  area,  from  one  foot 
to  a  foot  and  a  half  square.  The  arrows 
show  the  direction  of  the  flame  and  draught 
in  this  excellent  bench  of  retorts,  as 
mounted  by  Messrs.  Barlow. 

The  charge  of  coals  is  most  conveniently 
introduced  in  a  tray  of  sheet  iron,  made 
somewhat  like  a  grocer's  scoop,  adapted  to 
the  size  of  the  retort,  which  is  pushed  home 
to  its  further  end,  inverted  so  as  to  turn 
out  the  contents,  and  then  immediately 
withdrawn. 

The  duration  of  the  process,  or  the  time 
of  completing  a  distillation,  depends  upon 
the  nature  of  the  coal  and  the  form  of  the 
retort.  With  cylindrical  retorts  it  cannot 
be  finished  in  less  than  6  hours,  but  with 
elliptical  and  semi-cylindrical  retorts,  it  may 
be  completed  in  4  or  5  hours.  If  the  dis- 
tillation be  continued  in  the  former  for  8 
hours,  and  in  the  latter  for  6,  gas  will  continue  to  be  obtained,  but  during  the  latter  period 
of  the  operation,  of  indiflerent  quality. 

The  Receiver.  —  If  the  furnace  contains  only  2  or  3  retorts,  a  simple  cylindrical  vessel 
Standing  on  the  ground  half  filled  with  water,  may  serve  as  a  receiver;  into  which  the 
tube  from  the  retort  may  be  plunged.  It  should  be  provided  with  an  overflow  pipe  for  the 
tar  and  ammoniacal  liquor.  For  a  range  of  several  retorts,  a  long  horizontal  cylinder  is 
preferable,  like  that  represented  at  b  in  Jig.  671.  Its  diameter  is  from  10  to  15  inches. 
This  cylinder  may  be  so  constructed  as  to  separate  the  tar  from  the  ammoniacal  liquor, 
by  means  of  a  syphon  attached  to  one  of  its  ends. 

The  Condenser. —  The  condenser,  represented  in  Jig.  669,  consists  of  a  square  chest  g, 
made  of  wrought  iron  plates  open  at  top,  but  having  its  bottom  pierced  with  a  row  of 
holes,  to  receive  a  series  of  tubes.  To  these  holes  the  upright  four-inch  tubes  h  h  are 
secured  by  flanges  and  screws,  and  they  are  connected  in  pairs  at  top  by  the  curved  at 
saddle  tubes.  The  said  bottom  forms  the  cover  of  the  chest  t,  /,  which  is  divided  by  ver 
tieal  iron  partitions,  into  half  as  many  compartments  as  there  are  tubes. 


848 


GAS-LIGHT. 


GAS-LIGHT. 


849 


itt  proceeding  from  one  compartment  lo  another. 


These  partition  plates  are  left  open  at  bottom,  so  as  to  place  the  liquids  of  each  com- 
partment m  communication.      Thereby  the  gas  passes  up  and  down  (he  series  of  tubes, 

♦       .  .  .u-_      rpjj^  condensed  liquids  descend  into  the 

box  tj  tj  and  flow  over  into  the  tar 
cistern,  when  they  rise  above  ihe  leve, 
/,  /.  The  tar  may  be  drawn  off  from 
time  to  time  by  the  stopcock.  Through 
the  tube  fr,  cold  water  flows  into  the 
condenser  chest,  and  the  warm  water 
passes  away  by  a  pipe  at  its  upper 
edge. 

TiiC  extent  of  surface  which  the  gas 
requires  for  its  refrigeration  before  it 
is  admitted  into  the  washing-lime  ap- 
paratus, depends  upon  the  tempera- 
ture of  the  milk  of  lime,  and  the 
quantity  of  gas  generated  in  a  certain 
time. 

It  may  be  assumed  as  a  determination 
sufliciently  exact,  that  10  square  feet 
of  surface  of  the  condenser  can  cool 
a  cubic  foot  of  gas  per  minute  to  the 
temperature  of  the  cooling  water. 
For  example,  suppose  a  furnace  or 
arch  with  5  retorts  of  150  pounds  of 
. .     _         -  coal  each,  to  produce  in  5  hours  3000 

cnbiic  teet  of  gas,  or   10  cubic  feet  per  minute,  there  would  be  required,  for  the  cooling 
surface  of  the  condenser,  100  square  feet  =  10  X  10.      Sui)pose  100,000  cubic  feet  ol 
gas  to  be  produced  m  24  hours,  for  which  8  or  9  such  arches  must  be  employed,  the  con- 
densmg  surface  must  contain  from  800  to  900  square  feet. 

r/ie  Pttn^er.— The  apparatus  represented  in  the  preceding  figure  is  composed  of  a 
cylindrical  iron  vessel,  with  an  air- tieht  cover  screwed  ^pon  it,  through  which  the  cylinder 
n  IS  also  fixed  air-ti?ht.  The  bottom  of  this  cylinder  spreads  out  like  the  biim  of  a  hat, 
Ibrming  a  horizontal  circular  partition,  which  is  pierced  with  holes.  Through  a  stuffing 
box,  m  the  cover  of  this  interior  cylinder,  the  vertical  axis  of  the  agitator  passes,  which 
IS  turned  by  wheel  and  pinion  work,  in  order  to  stir  up  the  lime  from  the  bottom  of  the 
water  in  the  purifier.  The  vessel  o  serves  for  introducing  fresh  milk  of  lin)e,  as  also  for 
letting  It  oflT  by  a  stopcock  when  it  has  become  too  foul  for  further  use. 

The  quantity  of  lime  should  be  proportioned  to  the  quantity  of  sulphureted  hydrogen 
and  carbonic  acid  contained  in  the  gas.  Supposing  that  in  good  coal  gas  there  is  5  per 
cent,  of  these  gases,  about  one  pound  and  a  half  of  lime  will  be  requisite  for  every  hun- 
dred cubic  feet  of  coal  gas  generated,  which  amounts  to  nearly  one  sixteenth  of  the 
weight  of  coal  subjected  to  decomposition.  This  quantity  of  lime  mixed  with  the  proper 
quantity  of  water  will  form  about  a  cubic  foot  of  milk  of  lime.  Consequently,  the 
capacity  of  the  purifier,  that  is,  of  the  interior  space  filled  with  liquid,  may  be  taken  at 
tour  sevenths  of  a  cubic  foot  for  every  hundred  cubic  feet  of  gas  passing  through  it  in 
one  operation ;  or  for  175  cubic  feet  of  gas,  one  cubic  foot  of  liquor.  After  every 
operation,  that  is,  afier  every  five  or  six  hours,  the  purifier  must  be  filled  afresh.  Sup- 
pose  that  m  the  course  of  one  operation  20,000  cubic  feet  of  gas  pass  through  the 
„.,.       «v     u     u  ,       ,,  20,000 

machine,  this  should  be  able  to  contain-jy3-  =  1 14  cubic  feet  of  milk  of  lime ;  whence 

its  diameter  should  be  seven  feet,  and  the  height  of  the  liquid  three  feet.    If  the  capacity 
of  «ie  vessel  be  less,  the  lime  milk  must  be  more  frequently  changed. 

*n  some  of  the  large  gas  works  of  London  the  purifier  has  the  following  construction, 
whereby  an  uninterrupted  influx  and  efflux  of  milk  of  lime  takes  place.  Three  single 
purifiers  are  so  connected  together,  that  the  second  vessel  stands  higher  than  the  first, 
and  the  third  than  the  second  ;  so  that  the  discharge  tube  of  the  superior  vessel,  placed 
somewhat  below  Its  coyer,  enters  into  the  upper  part  of  the  next  lower  vessel;  conse- 
quently, should  the  milk  of  limo  in  the  third  and  uppermost  vessel  rise  above  its  ordi- 
nary level,  it  will  flow  over  into  the  second/ and  thence  in  the  same  way  into  the  first; 
from  which  It  is  let  off  by  the  eduction  pipe.  A  tube  introduces  the  gas  from  the  con- 
denser into  the  first  vessel,  another  tube  does  the  same  thing  for  the  second  vessel,  &c., 
and  the  tube  of  the  third  vessel  conducts  the  gas  into  the  gasometer.      Into'lhe  third 


vepsel,  milk  of  lime  is  constantly  made  to  flow  from  a  cistern 


upon  a  higher  level. 


By  this  arrangement,  the  gas  passing  through  the  several  vessels  in  proportion  as  it 
IS  purified,  comes  progressively  into  contact  with  purer  milk  of  lime,  whereby  its  purifi. 
cation  becomes  more  complete.      The  agitator  c,  provided  with  two  stirring  paddles,  if 


kept  in  continual  rotation.    The  pressure  which  the  gas  has  here  to  overcome  is  naturally 
three  times  as  great  as  with  a  single  purifier  of  like  depth. 

Fig.  612  is  a  simple  form  of  purifier,  which  has  been  found  to  answer  well  in  practice. 
Through  the  cover  of  the  vessel  a  b,  the  wide  cylinder  c  d  is  inserted,  having  its  lower 
end  pierced  with  numerous  holes.  Concentric  with  that  cy..nder  is  the  narrower  one  s  z, 
bound  above  with  the  flange  a  b,  but  open  at  top  and  bottom.  The  under  edge  g  h  of 
.this  cylinder  descends  a  few  inches  below  the  end  c  d  of  the  outer  one.  About  the  middle 
"of  the  vessel  the  perforated  shelf  m  n  is  placed.  The  shaft  of  the  agitator  /,  passes 
through  a  stuffing  box  upon  the  top  of  the  vessel.  The  gas-pipe  g,  proceeding  from  the 
condenser,  enters  through  the  flange  a  6  in  the  outer  cylinder,  while  the  gas-pipe  h  goes 
from  the  cover  to  the  gasometer.  A  stopcock  upon  the  side,  whose  orifice  of  discharge  is 
somewhat  higher  than  the  under  edge  of  the  outer  cylinder,  serves  to  draw  off  the  milk 
of  lime.  As  the  gas  enters  through  the  pipe  g  into  the  space  between  the  two  cylinders, 
it  displaces  the  liquor  till  it  arrives  at  the  holes  in  the  under  edge  of  the  outer  cylinder 
through  which,  as  well  as  under  the  edge,  it  flows,  and  then  passes  up  through  the  aper- 
tures of  the  shelf  m  n  into  the  milk  of  lime  chamber;  the  level  of  which  is  shown  by 
the  dotted  line.  The  stirrer,  /,  should  be  turned  by  wheel  w^ork,  thou^'h  it  is  here  shown 
as  put  in  motion  by  a  winch  handle. 

In  order  to  judse  of  the  degree  of  purity  of  the  gas  aftei  its  transmission  through  the 
lime  machine,  a  slender  syphon  tube  provided  with  a  stopcock  may  have  the  one  end 
inserted  in  its  cover,  and  the  other  dipped  into  a  vessel  containing  a  solution  of  acetate 
of  lead.  Whenever  the  solution  has  been  rendered  turbid  by  the  precipitation  of  sulpha- 
ret  of  lead,  it  should  be  renewed.  The  saturated  and  fetid  milk  of  lime  is  evaporated 
in  oblong  cast-iron  troughs  placed  in  the  ash-pit  of  the  furnaces,  and  the  dried  lime 
is  partly  employed  for  luting  the  apparatus,  and  partly  disposed  of  for  a  mortar  or 
manure. 

By  this  purifier,  and  others  of  similar  construction,  the  gas  in  the  preceding  parts  of 
the  apparatus,  as  in  the  retorts  and  the  condenser,  suffers  a  pressure  equal  to  a  column 
of  water  about  two  feet  high  ;  and  in  the  last  described  purifier  even  a  greater  pressure. 
This  pressure  is  not  disadvantageous,  but  is  of  use  in  two  respects ;  1.  it  shows  by  a 
brisk  jet  of  gas  when  the  apparatus  is  not  air-tight,  and  it  prevents  common  air  from 
entering  into  the  retorts ;  2.  this  compression  of  the  gas  favors  the  condensation  of  the 
tar  and  ammoniacal  liquor.  The  effect  of  such  a  degree  of  pressure  in  expanding  the 
metal  of  the  ignited  retorts  is  quite  inconsiderable,  and  may  be  neglected.  Two  contri- 
vances have,  however,  been  proposed  for  taking  off  this  pressure  in  the  purifier. 

In  fig.  673,  m  m  are  two  similar  vessels  of  a  round  or  rectangular  form,  furnished  at 
their  upper  border  with  a  groove  filled  with  water,  into  which  the  under  edge  of  the 
cover  fits,  so  as  to  make  the  vessel  air-tight.  The  cover  is  suspended  by  a  cord  or  chain 
which  goes  over  a  pulley,  and  may  be  raised  or  lowered  at  pleasure.  The  vessels  them- 
selves have  perforated  bottoms,  r  r',  covered  with  wetted  moss  or  hay  sprinkled  over  with 
slaked  and  sifted  quicklime.  The  gas  passes  through  the  loosely  compacted  matter  of 
the  first  vessel,  by  entering  between  its  two  bottoms,  rises  into  the  upper  space  /  thence 
it  proceeds  to  the  second  vessel,  and,  lastly,  through  the  pipe  tt,  into  the  gasometer. 

674  Th's  method,  however,  requires 
twice  as  much  lime  as  the  former, 
without  increasing  the  purity  ol* 
the  gas. 

The  second  method  consists  in 
compressing  the   gas   by  the  ac- 
tion of  an  Archimedes  screw,  to 
such  a  degree,  before  it  is  admit- 
ted  into  the  purifier,  as  that   it 
may   overcome   the   pressure  of 
the    column    of   water    in    that 
vessel.     Fig.    674  exhibits   this 
apparatus  in  section,     d  d  is  the 
Archimedes   worm,   the   axis  of 
which  revolves  at   bottom   upon 
the  gudgeon  e;    it   possesses  a 
three-fold  spiral,   and   is  turned 
in  the  opposite  direction  to  that 
in    which    it    scoops    the    water. 
The  cistern  which  contains  it  has 
an  air-tight  cover.      The  gas  to 
be  purified   passes    through   the 
pipe  c  into  the  space  d,  over  the 
water  level  d;  the  upper  cells  of  the  worm  scoop  in  the  gas  at  thU  point,  and 


I 


850 


GAS-LIGHT. 


carry  it  downwards,  where  it  enters  at  g  into  the  cavity  e  of  a  second  cistern.  In  order 
thai  the  gas,  after  it  escapes  from  the  bottom  of  the  worm,  may  not  partially  return 
throucrh  /into  the  ca<rily  d,  an  annular  plate  g  h  is  attached  to  its  under  edge  so  as  to 
turn  over  it.  The  compressed  gas  is  conducted  from  the  cavity  e  through  the  pipe  g 
into  the  purifying  machine ;  a  is  a  manometer,  to  indicate  the  elastic  tension  of  the  gas 
in   D.      On   the  top  of  the  worm   a  mechanism  is   Btted  for  keeping  it  in   constant 

^°  A  perfect  purification  of  light-gas  from  sulphureted  hydrogen,  either  by  milk  of  lime 
or  a  solution  of  the  green  sulphate  of  iron,  is  attended  with  some  difficulty,  when  carried 
so  far  as  to  cause  no  precipitation  of  sulphuret  in  acetate  of  lead,  because  such  a  degree 
of  washing  is  required  as  is  apt  to  diminish  its  illuminating  power,  by  abstracting  the 
vapor  of  the  rich  oily  hydrocarburet  which  it  contains.  Moreover,  the  coal  gas  obtained 
towards  the  end  of  the  distillation  contains  some  sulphuret  of  carbon,  which  aHords  sul- 
phurous acid  on  being  burned,  and  can  be  removed  by  no  easy  method  hitherto  known. 
The  lime  in  the  purifier  disengages  from  the  carbonate  and  hydro-sulphuret  of  ammonia 
carried  over  with  the  gas,  especially  when  it  has  been  imperfectly  cooled  m  the  condenser, 
a  portion  of  ammoniacal  gas,  which,  however,  is  not  injurious  to  its  illuminating  power. 
The  best  agent  for  purifying  gas  would  be  the  pyrolignite  of  lead,  were  it  not  rather  ex 
pensive,  because  it  would  save  the  trouble  of  stirring,  and  require  a  smaller  and  simpler 

apparatus.  .      r  •  •       «», 

The  Gasometer.— The  gasometer  serves  not  merely  as  a  magazine  for  receiving  itic 
gas  when  it  is  purified,  and  keeping  it  in  store  for  use,  but  also  for  communicating  to 
the  gas  in  the  act  of  burning  such  a  uniform  pressure  as  may  secure  a  steady  unflick- 
ering  flame.  It  consists  of  two  essential  parts  ;  1.  of  an  under  cistern,  open  at  top  and 
filled  with  water ;  and  2.  of  the  upper  floating  cylinder  or  chest,  which  is  a  similar 
cistern  inverted,  and  of  somewhat  smaller  dimensions,  called  the  gas-holder;  see  r, 
fig.  669.  The  best  form  of  this  vessel  is  the  round  or  cylindrical ;  both  because  under 
equal  capacity  it  requires  least  surface  of  metal,  and  it  is  least  liable  to  be  warped  by  its 
own  weight  or  accidents.  Since  a  cylindrical  body  has  the  greatest  capacity  with  a 
given  surface  when  its  height  is  equal  to  its  semi-diameter,  its  dimensions  ought  to  be 
such  that  when  elevated  to  the  highest  point  in  the  water,  the  height  may  be  equal  to 
the  radius  of  the  base.  For  example,  let  the  capacity  of  the  gas-holder  »n  cubic 
feet    be  fe,  the  semi-diameter  of  its  base  be  x,  the  height  out  of  the  water  be  ^; 

hi&=x  =  V_Jc_  ^  This  height  may  be  increased  by  one  or  two  feet,  according  to  its 

3*14  * 
magnitude,  to  prevent  the  chance  of  any  gas  escaping  beneath  its  nnder  edge,  when  it  is 
raised  to  its  highest  elevation  in  the  water. 

The  size  of  the  gasometer  should  be  proportional  to  the  quantity  of  gas  to  be  con 
sumed  in  a  certain  time.  If  120,000  cubic  feet  be  required,  for  instance,  in  10  nours 
for  street  illumination,  and  if  the  gas  retorts  be  charged  four  times  in  24  hours,  dU,UUU 
feet  of  gas  will  be  generated  in  6  hours.  Hence  the  gasometer  should  have  a  capacity 
of  at  least  70,000  cubic  feet,  supposing  the  remaining  50,000  cubic  feet  to  be  produced 
during  the  period  of  consumption.  If  the  gasometer  has  a  smaller  capacity,  it  must  be 
supplied  from  a  greater  number  of  retorts  during  the  lighting  period,  which  is  not 
advantageous,  as  the  first  heating  of  the  supernumerary  retorts  is  wasteful  of  luel. 
Some  engineers  consider  that  a  capacity  of  30,000  cubic  feet  is  the  largest  which  can 
with  propriety  be  given  to  a  gasometer;  in  which  case  they  make  its  diameter  42  teet, 
and  its  height  23.  When  the  dimensions  are  greater,  the  sheet  iron  must  be  thicker 
and  more  expensive ;  and  the  hoUow  cylinder  must  be  fortified  by  strong  internal  cross 

The  water  cistern  is  usually  constructed  in  this  country  with  cast-iron  plates  bolted  to- 
gether, and  made  tisrht  with  rust-cement.  .  ,    ,     •  •     . 

In  cases  where  the  weight  of  water  required  to  fill  such  a  cistern  might  be  inconvenient 
to  sustain,  it  may  be  made  in  the  form  represented  in  fig.  675 ;  which,  however,  will  cost 
nearly  twice  as  much.  Parallel  with  the  side  of  the  cistern,  a  second  cylinder  c,  of  the 
same  shape,  but  somewhat  smaller,  is  fixed  in  an  inverted  position  to  the  bottom  ol  the 
first  so  as  to  leave  an  annular  space  b  b  between  them,  which  is  filled  witli  water,  and 
in  which  the  floating  gasometer  a  plays  up  and  down.  The  water  must  stand  above  the 
cover  of  the  inverted  cylinder.  a  and  6  are  the  pipes  for  leading  the  gas  m  and  out. 
Through  an  opening  in  the  masonry  upon  which  the  gasometer  apparatus  rests,  the 
space  c  may  be  entered,  in  order  to  make  any  requisite  repairs.  j      •  v*     •,». 

The  water  cistern  may  also  be  sunk  in  the  ground,  and  the  sides  made  tight  wiin 
hydraulic  mortar,  as  is  shown  in  fig.  675,  and  to  make  it  answer  with  less  water,  a  con- 
centric  cylindrical  mass  of  masonry  may  be  built  at  a  distance  of  2  or  3  inches  ^»tnin  ic 

Every  lar«'e  gasometer  must  be  strengthened  interiorly  with  cross  iron  rods,  to  stmen 
both  ite  top°and  bottom.    The  top  is  supported  by  rods  stretching  obliquely  down  to 


GAS-LIGHT. 


851 


tJie  sides,  and  to  the  under  ed?e  an  iron  ring  is  attached,  consisting  of  curved  cast  iron 
bars  bolted  together  ;  with  which  the  oblique  rods  are  connected  by  perpendicular  ones. 


676 
B   TJ    B 


675 


E  F 

OHier  vertical  rods  stretch  directly  from  the  top  to  the  bottom  edge.  Upon  the  periphery 
of  the  top,  at  the  end  of  the  rods,  several  rings  are  made  fast,  to  which  the  gas-holder 
IS  suspended,  by  means  of  a  common  chain  which  runs  over  a  pulley  at  the  centre. 
U{>on  the  other  end  of  the  chain  there  is  a  counterpoise,  which  takes  off  the  greater  pari 
of  the  weight  of  the  gas-holder,  leaving  only  so  much  as  is  requisite  for  the  expulsion  of 
the  gas.  The  inner  and  outer  surfaces  of  the  gas-holder  should  be  a  few  times  rubbed 
over  with  hot  tar,  at  a  few  days'  interval  between  each  application.  The  pulley  must  be 
made  fast  to  a  strong  frame. 

If  the  water  cistern  be  formed  with  masonry,  the  suspension  of  the  gas-holder  may  be 
made  in  the  following  way.  a  a,  fig.  676,  is  a  hollow  cylinder  of  casi  iron,  standing  up 
through  the  middle  of  the  gasometer,  and  which  is  provided  at  either  end  with  another 
small  hollow  cylinder  g,  open  at  both  ends  and  passing  through  the  top,  with  its  axis 
placed  in  the  axis  of  the  gas-holder.  In  the  hollow  cylinder  G,the  counterweight  moves 
up  and  down,  with  its  chain  passing  over  the  three  pulleys  b,  b,  b,  as  shown  in  fig.  676. 
E  F  are  the  gas  pipes  made  fast  to  a  vertical  iron  rod.  Should  the  srasometer  be* made  to 
work  without  a  counterweight,  as  we  shall  presently  see,  the  central  cylinder  a  a,  serves 
as  a  vertical  sruide. 

In  proportion  as  the  gas-holder  sinks  in  the  water  of  the  cistern,  it  loses  so  much  of 
Its  weight,  as  is  equal  to  the  weight  of  the  water  displaced  by  the  sides  of  the  sinkin*' 
vessel;  so  that  the  gas-holder  when  entirely  immersed,  exercises  the  least  pressure  upon 
the  gas,  and  when  entirely  out  of  the  water,  it  exercises  the  greatest  pressure.  In  order 
to  counteract  this  inequality  of  pressure,  which  would  occasion  an  unequal  velocity  in 
the  efflux  of  the  gas,  and  of  course  an  unequal  intensity  of  light  in  its  flame,  the  weight  of 
the  chain  upon  which  the  gas-holder  hangs  is  so  adjusted  as  to  be  equal,  throughout  the 
length  of  its  motion,  to  one  half  of  the  weight  which  the  gas  holder  loses  by  immersion. 
In  this  case,  the  weight  which  it  loses  by  sinking  into  the  water,  is  replaced  by  the  por- 
tion of  the  chain  which,  passing  the  pulley,  and  hanging  over,  balances  so  much  of  the 
ci.ain  upon  the  side  of  the  counterweight ;  and  the  weight  which  it  eains  by  risin?  out 
of  the  water,  is  counterpoised  by  the  links  of  the  chain^ which,  passing  over  the  pulley, 
add  to  the  amount  of  the  counterweight.  The  pressure  which  the  gas-holder  exercises 
upon  the  gas,  or  that  with  which  it  forces  it  through  the  first  mam  pipe,  is  usually  so  reg- 
ulated as  to  sustain  a  column  of  from  one  to  two  inches  of  water;  so  that  the  water  will 
staid  in  the  cistern  from  one  to  two  inches  higher  within,  than  without  the  gas-holder. 
The  following  computation  will  place  these  particulars  in  a  clear  light. 

Let  the  semi-diameter  of  the  gas-holder,  equal  to  the  vertical  extent  of  its  motion  into 
and  out  of  the  water,  =Xi  let  the  weight  of  a  foot  square  of  the  side  of  the  gas-holder, 
including  that  of  the  strengthening  bars  and  ring,  which  remain  plunged  under  the  water, 
be  =  p ;   then 


652 


aAS-LIGH'i. 


GAS-LIGHT. 


853 


1.  the  weight  of  the  gas-holder  in  ita  highest  position  =  3  p  ir  x«; 

2.  the  wei-'ht  of  the  sides  of  the  gas-holder  which  play  in  the  water  =  2  p  t  xt; 

^  2  17  TT  xS* 

S.  the  cubic  contents  of  the  immersed  portion  of  the  gas-holder  =  -—-— 

112  ^^' 

4.  its  loss  of  weight  in  water  =  —p^^fl. 

5    the  weight  of  the  gas-holder  in  its  lowest  position  = 

/  1 1  •>  \ 


p  V  xi  13  — i_ 

\         400 /~ 


2-72pirx2; 

56 


6.  the  weight  of  n  inches,  height  of  water  =  "jg  n  n-  x* ; 


56n\ 

7.  the  amount  of  the  counterweight  =  n  afi)  3  p —  ^^  )  » 

8.  the  weight  of  the  chain  for  the  length  x  =  ^  p  ^  ^^ 

If  we  reduce  the  weight  of  the  gas-holder  in  its  highest  ^^^^  lowest  positioi«  to  th 
heichTof  a  stratum  of  water  equal  to  the  surface  of  its  top,  this  height  is  that  of  the 
column  of  water  which  would  press  the  gas  within  the  gasometer,  were  no  counterweight 
employed  ;  it  consists  as  follows  : — 

3p 

9.  for  the  highest  position  =  —  ; 

2-72  p . 


10.  for  the  lowest  =- 


For  the  case,  «hen  the  height  of  the  gas-holder  is  different  from  iU  ,emi-diamet.r. 
let  thi8  height  U  m  X ;  then  the  height  of  the  water  level  y>- 

11.  for  the  highest  position  =  p  ^      55      j  » 


4-t-l\72m\ 


12.  for  the  lowest  =  p{ — ^-g        ) 

13.  the  counterweight  =  7rx2^p(l-i-2m)—  _--j  ; 


112 
J 4.  the  weight  of  the  equalizing  chains  —  j»  ir  m  x2. 

•  ^%iStfu^%ii?r;-rp:s^^^^^^^ 

in  cubic  feet  will  be  IU,W/ ;,  p  -  *  P""'      '     ,   .    .     ^pi^ht  of  the  cha  n  for  a  length  of 

When  n  =  ^.^''-^^liTZ'^L^J^^^^^^  ^^«  -"-^  ^^^^ 

The  above  estimate  is  made  on  the  S'^PP^^^^^^"  ?J.^^^/,^  ^vVnearW  Uue  with  rega  d  to 
same  specific  gravity  as  the  atmospherica  air  wh  ch  w^^^^^  J^^j^^„ 

oil  gas  under  the  ordinajr  pressure,    ^ut  coal  g«s  whose  specinc  g        >^^^J^    ^^.^^ 

on  an  average  at  about  0-5,  exercises  J^^^^y^^^yi^ftJe  cub  c  foot  of  gas  to  be  =0-0364 

fouXthrcy^^^r^^^^^  ^---  '^  ^ 

"'ir  ihe^weTghTif^^^^^^^^^  hfghrst'position  =  3  p.  x^im  x,; 

,/3p-?i^\-0-1143x2; 

16.  the  counterweight  =  irx2ior       jg  / 

112  ^01143x3 

17.  the  weight  of  the  chain  for  the  length  ^-^^P""'  2       ' 

18   The  height  of  the  water  pressure  for  the  highest  position,  without  the  counter- 

,,     3pir— 01143  X. 

weight  =-i- — J  „  „_ 

2*72  p  .    *   . 
*      ^  m  feel 


56 


19.  the  same  for  the  lowest  position  =  -^ 


The  preceding  values  of  p  and  x  are, 

(16)  =  3147;  (17)  =  203 ;  (18)  =  2-44  inches;  (19)  =  2-33  inches. 
J  he  water  columns  in  the  highest  and  lowest  situations  of  the  gas-holder  here  diflei 
about  01  of  an  inch,  and  this  difJerenco  becomes  still  less  when  p  has  a  smaller  value, 
lor  example,  3  pounds,  or  when  the  diameter  of  ihe  gas-holder  is  still  greater. 

It  would  thus  appear  that  for  coal-gas  gasometers,  in  which  the  height  of  the  gas-holder 
does  not  exceed  its  semi-diameter,  and  especially  when  it  has  a  considerable  size,  neither 
a  compensation  cham  nor  a  counterweight  is  necessary.  The  only  thing  requisite,  is  to 
preserve  the  vertical  motion  of  the  gas-holder  by  a  sufficient  number  of  guide  rods  or 
pillars,  placed  either  withm  the  water  cisiern,  or  round  about  it.  Should  the  pressure 
of  the  gas  in  the  pipe  proceeding  from  the  gasometer,  be  less  than  in  the  -asomeler  itself, 
this  may  be  regulated  by  the  main  valve,  or  by  water  valves  of  various  kinds.  Or  a  small 
intermediate  regulating  gasometer  may  be  introduced  between  the  great  gas-holder,  and 
the  main  pipe  of  distribution.  With  a  diameter  of  61  feet  in  the  gas-holder,  the  pressure 
jn  the  highest  and  lowest  positions  is  the  same. 

The  gasometers  employed  in  storing  up  gas  until  required  for  use,  occupy,  upon  the 
old  plan,  much  space,  and  are  attended  with  considerable  expense  in  erecting  The 
water  tank,  whether  sunk  in  the  ground  or  raised,  must  be  of  equal  dimensions  with 
the  gasometer,  both  in  breadth  and  depth.  The  improved  construction  which  we  are 
about  to  describe,  affords  a  means  of  reducing  the  depth  of  the  tank,  dispensing  with  the 
bridge  of  suspension,  and  of  increasing  at  pleasure  the  capacity  of  the  gasometer,  upon  a 
given  base;  thus  rendering  a  small  apparatus  capable,  if  required,  of  holding  a  lar^'c 
quantity  of  gas,  the  first  cost  of  which  will  be  considerably  less  than  even  a  small  gi. 
ometer  constructed  upon  the  ordinary  plan. 

Mr.  Tait,  of  Mile-End  Road,  the  inventor,  has,  we  believe,  been  for  some  years 
connected  with  gas  establishments,  and  is  therefore  fully  aware  of  the  practical  defects 

or  advantages  of  the  different  constructions  of 
gasometers  now  in  use.  Fig.  t>l7  is  a  section 
of  Mr.  Tail's  improved  contrivance ;  a  a  is  the 
tank,  occupied  with  water,  6  b  two  iron  col- 
umns, with  pulley-wheels  on  the  top,  c  c, 
chains  attached  to  a  ring  of  iron,  d  rf,  extend- 
ing round  the  gasometer,  v.rhich  chains  pass 
over  the  pulley-wheels,  and  are  loaded  at  their 
extremilies,  for  the  purpose  of  balancing  the 
weight  of  the  mateiials  of  which  the  gasometer 
is  composed. 

The  gasometer  is  formed  by  2  or  3  cylinders, 
sliding  one  within  the  other,  like  the  tubes 
of  a  telescope ;  t,  g,  c,  is  the  first  or  outer  cyl 
inder,  closed  at  the  top,  and  having  the  rinj^ 
of  iron  rf,  passing  round  it,  by  which  "the  whole 
is  suspended  ;  //,  is  the  second  cylinder,  sliding 
freely  within  the  first,  and  there  may  be  a  third 
-„.        ,        .  and  fourth  within  these  if  necessary. 

When  mere  is  no  gas  in  the  apparatus,  all  the  cylinders  are  slidden  down,  and  remain 
one  withm  the  other  immersed  in  the  tank  of  water;  but  when  the  gas  rises  through  the 
water  pressing  against  the  top  of  the  gasometer,  its  buoyancy  causes  the  cylinder  c  to  as- 
cend. Round  the  lower  edge  of  this  cylinder  a  groove  is  formed  by  the  turning  in  of  the 
plate  of  iron  and  as  it  rises,  the  edge  takes  hold  of  the  lop  rimof  ihe  cylinder/,  which  is 
overlapped  for  that  purpose.  'We  groove  at  the  bottom  of  the  cylinder  fills  itself  with 
water  as  11  ascends,  and  by  the  rim  of  the  second  cylinder  falling  into  it,  an  air-light  hy- 
draulic  joint  is  produced.  s  »  "/ 

Thus  several  cylinders  may  be  adapted  to  act  in  a  small  tank  of  water,  by  sliding  one 
within  the  other,  with  lapped  edges  forming  hydraulic  joints,  and  by  supporting  the  ap- 
paratus  m  the  way  shown,  the  centre  of  gravity  will  always  be  below  the  points  of  sus^ 
pension  A  gasometer  may  be  made  upon  this  plan  of  any  diameter,  as  there  will  be  no 
need  of  frame-work,  or  a  bridge  to  support  it ;  and  the  increasing  weight  of  the  appara. 
tus  as  the  cylinders  are  raised  one  after  the  other,  may  be  counterpoised  by  loading  tke 
ends  of  the  chains  c  c.  /  s  »"c 

The  water  in  the  gasometer  need  not  be  renewed;  but  merely  so  much  of  u  as 
evaporates  or  leaks  out,  is  to  be  replaced.  Indeed,  the  surface  of  the  water  in  the  cistern 
gets  covered  with  a  stratum  of  coa  oil,  a  few  inches  deep,  which  prevents  its  evaporation, 
and  allows  the  gas  to  be  saturated  with  this  volatile  substance,  so  as  to  increase  its  lUu- 
minating  powers. 

The  gasometer  may  be  separated  from  the  purifier  by  an  intermediate  vessel  such 
Its  IS  represented  Jig-  678,  with  which  the  two  gas  pipes  are  connected,    a  is  the 


854 


GAS-LIGHT. 


GAS-LIGHT. 


I 


I 


cylindrical  vessel  of  cast  iron  a,  the  end  of  the  gas  pipe  which  comes  from  the  purifier 

immersed  a  few  mchcs  deep  mto  the  liquid  with 
which  the  vessel  is  about  two  thirds  filled ;  6  is 
the  gas-pipe  which  leads  into  the  gasometer; 
c  is  a  perpendicular  tube,  placed  over  the  boiiom 
of  the  vessel,  and  reaching  to  within  one  third  of 
the  top,  through  which  the  liquid  is  introduced 
678  into  the  vessel,  and  through  which  it  escapes  when 
it  overflows  the  level  d.  In  this  tube  the  liquid 
stands  towards  the  inner  level  higher,  in  propor- 
tion to  the  pressure  of  the  gas  in  the  gasometer. 
The  fluid  which  is  condensed  in  the  gas-pipe  b,  and 
in  its  prolongation  from  the  gasometer,  runs  off 
into  the  vessel  a  ;  and  therefore  the  latter  must  be 
laid  so  low  that  the  said  tube  may  have  the  requisite 
declivity.  A  straight  stopcock  may  also  be  attached 
to  the  side  over  the  bottom,  to  draw  ofFany  sediment. 

II.  Application  of  Light-Gas. 
1    Disirihulion  of  the  pipes.— The  pressure  by  which  the  motion  of  the  gas  is  main- 
tained  in  \he  pii^^^^  a  certain  height  of  water  in  the  c  stern  of  the  gasom- 

eter      From  the  SsiX^^^^      this  pressure,  and  the  quantity  of  gas  wh.ch  .n  a  g.ven 
Ume  as  an  hourrmust  be  transmitted  through  a  certain  length  of  P'P^^' depends  the 
wTdth  or  the  d'ameter  that  they  should  have  in  order  that  the  "^«^^-,-^y  ^JJ^^^^Jfi^^^ 
by  the  friction  which  the  gas,  like  all  other  fluids,  experiences  '^/"^f '  ^"f^.^j^^^^/, ^^^ 
sas  might  be  prevented  from  issuing  with  the  velocity  required  for   he  j els  of  flame^ 
The  velocitv  of  the  gas  in  the  main  pipe  increases  in  the  ratio  of  the  squa.e  root  ol  ine 
pr"cll  of  w^ter  upon  the  gisLeter,  and  ^l-refore  by  increasm^^^^^^^^ 
the  gas  may  be  forced  more  rapidly  along  the  remoter  «"^  ,^'"^"f /^^"^  f^^*^^^^^^ 
nimi      Thus  it  haonens  however,  that  the  gas  will  be  discharged  from  the  onhccs  near 
f^gksom  ter  wth'r^^^  velocity.,     it  is  therefore  .f-fjl^f  .^^r^^yj,^ 

such  a  manne?,  that  in  every  point  of  their  length  the  velocity  of  discharge  maj  be  nearly 

the'^rsuTersTmovin^ralong  the  pipes,  ^^fl^^l^Z^'^^^^^^^^^^^ 
.nitial  velocity   varies  with  the  square  root  of  flie  length.    The  volume  ol  gas  discnaigea 
from  the  enTof  a  P?pe^^^^  ^«  '^'^  ^^"^'^  of  its  diameter,  and  m- 

v^ely  as  the  sqLr^root  of  its  length  ;  or,  calling^the  length  l,  the  diameter  r>,  the  cubic 


855 


feet  of  gas  discharged  in  an  hour  k ;  then  k  — 


VL 


Experience  likewise  shows,  Iha 


for  a  pipe  250  feet  long,  which  transmits  in  an  hour  200  cubic  feet  of  gas,  one  inch  is 

a  suflficient  diameter. 

1  D«  __ 

Consequently,  200  :  fc  :: *•  "Jf  ?   and  D=  V  fe  V  l 

144  1/250      VL  -^^000" 

From  this  formula  the  following  table  of  proportions  is  calculated. 


Number  of  cubic  feet  per  hour. 


L 


50 

250 

500 

700 

1000 

1500 

2000 

2000 

2000 

2000 

6000 

6000 

80(X) 

8000 


Length  of  pipe,  in  feet. 


Diameter,  in  inches 


These  dimensions  are  applicable  to  the  case  where  the  body  of  gas  is  transmitted  through 


pipes  without  being  let  off  in  its  way  by  burners,  that  is,  to  the  mains  which  conduct  the 
gjs  to  the  places  where  it  is  to  be  used.  If  the  main  sends  off  branches  for  burners, 
"lenlor  the  same  length  the  diameter  may  be  reduced,  or  for  like  diameter  the  lensth 
my  be  greater.  For  example,  if  a  pipe  of  5-32  inches,  which  transmits  2000  cubic  feet 
through  a  length  of  2000  feet,  gives  off,  in  this  space,  1000  cubic  feet  of  gas ;  then  the 
remamaer  oi  the  pipe,  having  the  same  diameter,  can  continue  to  transmit  the  gas  throtigh 

a  length  of  2450  feet  =  (^^??-^) 2  with  undiminished  pressure  for  the  purposes  of  light- 

ing.  Inversely,  the  diameter  should  be  progressively  reduced  in  proportion  to  the  numb-r 
ol  jets  sent  off  m  the  length  of  ihe  pipe. 

„.??''r!t'  ^'^''  ^"^'\"^e'  ^he  gasometer  to  discharge  2000  cubic  feet  per  hour,  and  the  la  it 
point  of  the  jets  to  be  at  a  distance  of  4000  feet.  Suppose  also  that  from  the  gasomet  .t 
Hi.^  ,  r^T  ?^  ''^.^.^?-'  ^^^  '^^^  proceeds  through  1000  feet  of  close  pipe,  the 
diameter  of  the  pipe  will  be  here  4-47  inches;  in  the  second  1000  feet  of  length,  sup- 
fuL  ,1'^.^    °  f '''^  ''^'  ""^  ^^"^^  distances,  1000  cubic  feet  of  gas,  the  diameter  in 

this  lens-th  (calculated  at  1500  cubic  feet  for  1000  feet  long)  =  3-87  inches-  in  the 

Jecko'nint"~n'o  'T  Z'^/'?.^^^!^^  ^^f'  "^  ^""^  ""^  ^^  ^'^'^  ««">  ^^  the  diameler 
(reckoning  /OO  cubic  feet  for  1000  feet  long)  will  be  2-65   inches;  in  the  fourth  and 

noh  Tr^^"^^'^^  '"^'^^^.^^  ^"  ^^««  ^'''  '«"^>  ^^^  P'I^«  ^»-^  a'diameterof  onlyan 
h.il7h  ^  m'  f '  ""Y-'  '"^  P'^'^''^'  *  '^^-'"^^  ^^^^  ^""O"  P'Pe  is  substituted ;  this 
serted  *"  '°*'"''  '"^''  '^^''''^'    ^'''"''^  P'^^'  ^'^'^  ^^  conveniently  in- 

The  same  relations  hold  with  regard  to  branch  pipes  through  which  th-  gas  is  trans- 
muted into  buildings  and  other  places  to  be  illuminated.  If^such  pipes  rrlke  lUuent 
an^n lar  turnings,  whereby  they  retard  the  motion  of  the  gas,  they  must  be  a  third^or  a 
Ht'tiTanTnc'hTrborr^  ^"^^"^^'  '^'''  of  distribution  ar/ never  less  than  on^ 

nl«yi!!.?rr'"'*'".r^  ""^"V'^^  ^^'  '^°'"^'  *  ^^'■y  S^""^^^  quantity  of  light  is  required  in  panic 
ular  localities,  there  ought  to  be  placed  near  these  spots  gasometers  of  distribution  which 
being  filled  durino:  the  slack  hours  of  the  day,  are  ready  to  supply  the  bu  ne  s  a't  ^i^ht' 
without  makmg  any  considerable  demand  upon  the  original  main  pipe.  Suppose  he  first 
mam  be  required  to  supply  8000  cubic  feet  in  the  hoar,  for  an  ilium  nation  of  8  hours  a 
the  distance  of  2000  feet,  a  pipe  lOf  inches  in  diamete'r  would  be  necessary  but  if  tVo 
iLZ"  ^'"'.'''^T'  °^  '''^^•^^^"tion,  or  station  gasometer.,  be  had  recourse  [0  into  whilh 
fL^  I  e  cTtra  J '""'^r^K'  hours  would  flow  through  .he  same  distance  conlinuousT; 
S  of  8  Ono  fRf^r^  V^l-  ^"^"'^'y  ""^"''"^  ^''  ^°"'"  ^'-^^  *h^™  ^'^"'J  be  only  one 
inches  "  '"''  ^''"^^"^"'Jy  the  diameter  for  such  a  pipe  is  only  6-15 

All  the  principal  as  well  as  branch  pipes,  whose  interior  diameter  exceeds  an  inch  and 

ft  ifiecTss^n  '     Th^'  '""  'T  V""  '  '''t  ^^"='-"'''  ^'^°^  ^^^^  <=-'  -  them  wher' 
It  IS  necessary.      These  pipe  lengths  are  shown  in  Jig.  679,  havin-  at  one  end  a  wid/- 

socket  a,  and  at  the  other  a  nozzle  6,  which  fits  the  former.  '  Afier^nserlin-  the  one  i n 

the  other  m  their  proper  horizontal  position,  a  coil  of  hemp  soaked  with  tar  is  driven 

home  at  the  junction  ;  then  a  luting  of  clay  is  applied  at  the  mouth,  within  which  a  rina 

of  lead  IS  cast  mto  the  socket,  which  is  driven  tight  home  with  a  m^lllt  andllunt  chi-? 


679 

ETTTriTr 'i'^^i^^..f„ 
linnnun,,,, 


680 


The  pipes  should  be  proved  by  a  force  nnmn  hor«n«  k  •  •     j  • 

iwo  or  three  lengths  of  them  should  be  io^nThr.^""  T^'^'f  '"^^  ^'"^  ^^«  ^«'''f»; 
be  placed  at  least  two  feet  I  ow  the  suIZ^  to  °'"'  '»y'"§^  .^hem  down,  and  they  should 
of  temperature,  which  would  looTenthet^^^^^^^  TheTutl  fo"  ""?"'  fvTi  '^  ^^""^^ 
of  small  size,  are  made  of  lead,  copper  w  ought  Iron,  o^^  a  "     ^-^"^>"tion,  when 


856 


GAS-LIGHT 


Iflslrad  of  a  stopcock  for  letting  off  the  eas  in  regulated  quantities  from  the  gas- 
ometer, a  pecu.iarly  formed  water  or  mercurial  valve  is  usually  employed.  Fig.  680 
shows  the  mode  of  construction  for  a  water  trap  or  lute,  and  is,  in  fact,  merely  a  gas- 
ometer in  miniature,  c  d  e  f  is  a  square  cast  iron  vessel,  in  the  one  side  of  which  a  pipe 
A  is  placed  in  communication  with  the  gasometer,  and  m  the  other,  one  with  the  main  b, 
The  moveable  cover  or  lid  h  g  i  k  has  a  partition,  i.  M,  in  its  middle.  If  this  cover  be 
raised  by  its  counterweight,  the  gas  can  pass  without  impediment  from  a  to  b  ;  but  if  the 
ct.unterweisht  be  diminished  so  as  to  let  the  partition  plate  l  m  sink  into  the  water,  the 
communication  of  the  two  pipes  is  thereby  interrupted.  In  this  case  the  water-level 
stands  in  the  compartment  a  so  much  lower  than  outside  of  it,  and  in  the  comparimeni 
B,  as  is  equivalent  to  tlie  pressure  in  the  gasometer ;  therefore  the  pipes  a  and  b  must 
project  thus  far  above  the  water.  In  order  to  keep  the  water  always  at  the  same  height, 
and  to  prevent  it  from  flowing  into  the  mouths  of  these  pipes,  the  rim  c  D  of  the  outer 
vessel  stands  somewhat  lower  than  the  orifices  A  b  ;  and  thence  the  vessel  may  be  kepi 
always  full  of  water. 
If  a  quicksilver  valve  be  preferred,  it  may  be  constructed  as  shown  in  Jig.  681.    a  b  are 

the   terminations   of  the   two   gas   pipes, 
which  are  made  fast  in  the  rectangular 
iron  vessel  m.      e  is  an  iron  vessel  of  the 
same  form,  which  is  filled  with  quicksilver 
up  to  the  level  a,  and  which,  by  means  of 
the  screw   g,  which    presses    aeainst    its 
bottom,  and  works  in  the  fixed  female  screw 
c  c,  may  be  moved  up  or  down,  so  that  the 
vessel  M  may  be  immersed  more  or  less  into 
the  quicksilver.    The  vessel  m  is  furnishet' 
with  a  vertical  partition  m  ;  the  passage  oi 
the  gas  from  a  to  b  is  therefore  obstructed 
when  this  partition  dips  into  the  quick- 
silver, and  from  the  gradual  depression  of 
the  vessel  e  by  its  screw,  the  interval  be 
tween  the  quicksilver  and  the  lower  edge 
of  the  partition,  through  which  the   gag 
must  enter,  may  be  enlarged  at  pleasure, 
whereby  the  pressure  of  the  gas  in  b  may 
be  regulated  to  any  degree.      The  trans- 
verse section  of  that  interval  is  equal  to 
the  area  of  the  pipe  or  rather  greater ;  the 
breadth   of   the   vessel    m   from    a   to   b 
amounts  to  the  double  of  that  space,  and 
its  length  to  the  mere  diameter  of  a  or  b. 
The  greatest  height  to  which  the  partition 
m  can  rise  out  of  the  quicksilver,  is  also 
equal  to  the  above  diameter,  and  in  this 
case  the  line  a  comes  to   the  place  of  b. 
The  vertical  movement  of  the  outer  vessel 
e,  is  secured  by  a  rectangular  rim  or  hoop 
which  surrounds  it,  and  is  made  fast  to  the 
upper  part  of  the  vessel  m,  within  which 
guide  it  moves  up  and  down.      Instead  of 
the  lever  d  d,  an  index  with  a  graduated 
plate  may  be  employed  to  turn  the  screw, 
and  to  indicate  exactly  the  magnitude  in 
the  opening  of  the  valve. 

In  order  to  measure  the  quantity  of  iraa 
which  passes  through  a  pipe  for  lightitg  a 
factory,  theatre,  &c.,  the  gas-meter  is  em- 
ployed, of  whose  construction  asitficientiy 
precise  idea  may  be  formed  from  the  con- 
sideration oCJig.  682,  which  shows  the  in- 
strument in  a  section  perpendicular  to  its 
axis. 

Within  the  cylindrical  case  a,  there  is 
a  shorter  cylinder  b  6,  shut  at  both  ends, 

and   moveable   round   an    axis,  which   is 

divided    into   four    compartments,   that    communicate    by    the    opening    d,   with    the 
interval    between    this  cylinder  and    the  outer  case        The    mode    in   which    this 


GAS-LIGHT. 


867 


cylinder  turns  round  its  axis  is  as  follows  :— The  end  of  the  tube  c,  which  is  made  fast  to 
the  side  of  the  case,  and  by  which  the  gas  enters,  carries  a  pivot  or  gudgeon,  upon  which 
the  centre  of  its  prop  turns ;  the  other  end  of  the  axis  runs  in  the  cover,  which  here  forms 
the  side  of  a  superior  open  vessel,  in  which,  upon  the  same  axis,  there  is  a  toothed  wheeL 
The  vessel  is  so  far  filled  with  water,  that  the  tube  c  just  rises  above  it,  which  position 
is  secured  by  the  level  of  the  side  vessel.  When  the  gas  enters  through  the  tube  c,  by 
its  pressure  upon  the  partition  e  (Jig.  682),  it  turns  the  cylinder  from  right  to  left  upoB 
its  axis,  till  the  exterior  opening  d  rises  above  the  water,  and  the  gas  expands  itself  in 
the  exterior  space,  whence  it  passes  off  through  a  lube  at  top.  At  every  revolution,  a 
certain  volume  of  gas  thus  goes  through  the  cylinder,  proportional  to  its  known  capa- 
city. The  wheel  on  the  axis  works  in  other  toothed  wheels,  whence,  by  means  of  an 
index  upon  a  graduated  disc  or  dial,  placed  at  the  top  or  in  front  of  the  gas-meter, 
the  number  of  cubic  feet  of  gas,  which  pass  through  this  apparatus  in  a  given  time,  is 
registered. 

B.  Employment  of  the  gas  for  lighting. — The  illuminating  power  of  different  gases 
burned  in  the  same  circumstances,  is  proportional,  generally  speaking,  to  their  specific 
gravity,  as  this  is  to  the  quantity  of  carbon  they  hold  in  combination.  The  following 
table  exhibits  the  different  qualities  of  gases  in  respect  to  illumination. 


Density  or  specific  gravity. 

Propoition  of  light  afforded  by  coal 
gas  to  oil  gas. 

Coal  gas. 

Oil  gas. 

0-659 
0-578 
0-605 
0-407 
0-429 
0-508 

0-818 
0-910 
1-110 
0-940 
0-965 
1-175 

100  :  140 
100  :  225 
100  :  250 
100  :  354 
100  :  356 
100  :  310 

Mean  0.529 

0-96 

100  :  272                        j 

In  the  last  three  proportions,  the  coal  gas  was  produced  from  coals  of  middle  quality ; 
in  the  first  three  proportions,  from  coals  of  good  quality ;  and  therefore  the  middle  pro- 
portion of  100  to  270  may  be  taken  to  represent  the  fair  average  upon  the  great  scale. 
On  comparing  the  gas  from  bad  coals,  with  good  oil  gas,  the  proportion  may  become 
100  to  300.  Nay,  coal  gas  of  specific  gravity  0-4,  compared  to  oil  gas  of  1-1,  gives  the 
proportion  of  1  to  4.  A  mould  tallow  candle,  of  6  in  the  pound,  burning  for  an  hour, 
is  equivalent  to  half  a  cubic  foot  of  ordinary  coal  gas,  and  to  four  tenths  of  a  foot  o{ 
good  gas.  The  flame  of  the  best  argand  lamp  of  Carcel,  in  which  a  steady  supply  of  oil 
is  maintained  by  pump-work,  consuming  42  grammes  =  649  grains  English  in  an  hour, 
and  equal  in  light  to  9-38  such  candles,  is  equivalent  to  3-75~cubic  feet  of  coal  gas  per 
hour.  The  sinumbra  lamp,  which  consumes  50  grammes  =  772  grains  English,  of  oil 
per  hour,  and  gives  the  light  of  8  of  the  above  candles,  is  equivalent  to  the  light  emitted 
by  3-2  cubic  feet  of  coal  gas  burning  for  an  hour.  A  common  argand  lamp,  equal  to  4 
candles,  which  consumes  30  grammes  =  463  grains  English  per  hour,  is  represented  by 
1-6  cubic  feet  of  gas  burning  during  the  same  time.  A  common  lamp,  with  a  flat  wick 
and  glass  chimney,  whose  light  is  equal  to  1-13  tallow  candles,  and  which  consumes  11 
grammes  =  169-8  grains  English  per  hour,  is  represented  by  0*452  of  a  ^ubic  foot  of 
gas  burning  for  the  same  time. 

Construction  of  ihe  Burners. — The  mode  of  burning  the  gas  as  it  issues  from  the  jets 
has  a  great  influence  upon  the  quantity  and  quality  of  its  light.  When  carbureted 
hydrogen  gas  is  transmitted  through  ignited  porcelain  tubes,  it  is  partially  decomposed 
with  a  precipitation  of  some  of  its  carbon,  while  the  resulting  gas  burns  with  a  feebler 
flame.  Coal  gas,  when  kindled  at  a  small  orifice  in  a  tube,  undergoes  a  like  decompo- 
sition and  precipitation,  its  hydrogen,  with  a  little  of  its  carbon,  bums  whenever  it 
comes  into  contact  with  the  atmospherical  air,  with  a  bluish  colored  flame;  but  the 
carbonaceous  part  not  being  so  accendible,  takes  fire  only  when  mixed  with  more  air ; 
therefore  at  a  greater  distance  from  the  beak,  and  with  a  white  light  from  the  vivid 
ignition  of  its  solid  panicles.  Upon  this  principle  pure  hydrogen  gas  may  be  made  tc 
burn  with  a  white  instead  of  its  usual  blue  flame,  by  dusting  into  it  particles  of  lamp 
black,  or  by  kindling  it  at  the  extremity  of  a  tube  containing  finely  pulverized  zinc. 
The  metallic  particles  become  ignited,  and  impart  their  bright  light  to  the  pale  blue 
flame.  Even  platinum  wire  and  asbestos,  when  placed  in  the  flame  of  hydrogen  gas, 
serve  to  whiten  it.  Hence  it  has  been  concluded,  that  the  intensity  of  light  which  a 
gas  IS  capable  of  affording  is  proportional  to  the  quantity  of  solid  particles  which  it 


I 

I 


858 


GAS-LIGHT 


GAS-LIGHT. 


859 


contains,  and  can  precip.tate  in  the  act  of  burninu.  Carbonic  oxyde  g&s  burns  witl.  thf 
feeblest  light  next  It)  hydrogen,  because  it  deposiles  no  carbon  in  the  act  of  burning 
Phosphureted  hydrogen  gives  a  brilliant  light,  because  the  phosphoric  acid,  into  which 
its  base  is  converted  during  the  combustion,  is  a  solid  substance,  capable  of  being 
ignited  in  the  flame,  defiant  gas,  as  also  the  vapor  of  hydro-carbon  oil,  emits  a 
more  vivid  light  than  common  coal  gas ;  for  the  first  is  composed  of  two  measures  of 
hydrogen  and  two  measures  of  the  vapor  of  carbon  condensed  into  one  volume  ;  while 
the  last  contains  only  one  measure  of  the  vapor  of  carbon  in  the  same  bulk,  and 
combined  with  the  same  proportion  of  hydrogen,  defiant  gas  may  therefore  be  ex- 
pected to  evolve  a  double  quantity  of  carbon  in  its  flame,  which  should  emit  a  double 

light. 

The  illuminating  power  of  the  flame  of  coal  gas  is,  on  the  contrary,  impaired,  when, 
by  admixture  with  other  species  of  gas  which  precipitate  no  carbon,  its  own  ignited  par- 
ticles are  diflTused  over  a  greater  surface.  This  happens  when  it  is  mixed  with  hydrogen, 
carbonic  oxyde,  carbonic  acid,  and  nitrogen  gases,  and  the  diminution  of  the  light  is  pro- 
portional to  the  dilution  of  the  coal  gas. 

In  like  manner  the  illuminating  power  of  coal  gas  is  impaired,  when  it  is  consumed 
loo  rapidly  to  allow  time  for  the  separation  and  ignition  of  its  carbonaceous  matter;  it 
burns,  in  this  case,  without  decomposition,  and  with  a  feeble  blue  flame.  1.  This 
occurs  when  the  light-gas  is  previously  mixed  with  atmospherical  air,  because  the 
combustion  is  thereby  accelerated  throughout  the  interior  of  the  flame,  so  as  to  prevent 
the  due  separation  of  carbon.  A  large  admixture  of  atmospherical  air  makes  the  flame 
entirely  blue.  2.'  When  it  issues,  with  considerable  velocity,  from  a  minute  orifice, 
whereby  the  gas,  by  expansion,  gets  intimately  mixed  with  a  large  proportion  of  atmos- 
pherical air.  If  the  jet  be  vertical,  the  bottom  part  of  the  flame  is  blue,  and  the  more 
so  the  less  carbon  is  contained  in  the  gas.  The  same  thing  may  be  observed  in  the  flame 
of  tallow,  wax,  or  oil  lights.  The  burning  wick  ads  the  part  of  a  retort,  in  decom- 
posing the  fatty  matter.  From  ihe  lower  part  of  the  wick  tne  gases  and  vapors  of  the 
fat  issue  with  the  greatest  velocity,  and  are  most  freely  mixed  with  the  air ;  while  the 
gases  disengaged  from  the  upper  part  of  the  wick  compose  the  interior  of  the  flame,  and 
being  momentarily  protected  from  the  action  of  the  atmosphere,  acquire  the  proper  high 
temperature  for  the  deposition  of  carbon,  which  is  then  diflTused  on  the  outec  surface  in 
an  ignited  slate,  and  causes  its  characteristic  white  light.  Hence  with  coal  gas,  the  light 
increases  in  a  certain  ratio  with  the  size  of  the  flame  as  it  issues  from  a  larger  orifice, 
because  the  intermixture  of  air  becomes  proportionately  less.  3.  If  by  any  means  too 
great  a  draught  be  given  to  the  flame,  its  light  becomes  feebler  by  the  rapidity  and  com- 
pleteness with  which  the  gras  is  burned,  as  when  too  tall  a  chimney  is  placed  over  an 
argand  burner,  see  Jig.  683.  Fig.  684,  c,  is  a  view  of  the  upper  plate,  upon  which  the 
glass  chimney  6  rests.  The  gas  issues  through  the  smaller  openings  of  the  inner  ring, 
and  forms  a  hollow  cylindrical  flame,  upon  the  outside  as  well  as  the  inside  of  which  the 
atmospherical  air  acts.  The  illuminating  power  of  this  flame  may  be  diminished  at 
pleasure,  according  as  more  or  less  air  is  allowed  to  enter  through  the  orifices  beneath. 
With  a  very  f (111  draught  the  light  almost  vanishes^  leaving  only  a  dull  blue  flame  of 
great  heating  power,  like  that  of  the  blowpipe,  corresponding  to  the  perfect  combustion 
of  the  gas  without  precipitation  of  its  carbon.  4.  On  the  other  hand,  too  small  a  draught 
of  air  is  equally  prejudicial;  not  merely  because  a  portion  of  the  carbon  thus  escape? 
unconsumed  in  smoke,  but  also  because  the  highest  illuminating  power  of  the  flame  is 
obtained  only  when  the  precipitated  charcoal  is  heated  to  whiteness;  a  circumstance 
which  requires  a  considerable  draught  of  air.  Hence  the  flame  of  dense  oil  gas,  or  of 
oil  in  a  wick,  burns  with  a  yellow  light  without  a  chimney ;  but  when  it  is  increased  in 
"ntensity  by  a  chimney  draught,  it  burns  with  a  brilliant  white  flame. 

From  the  consideration  of  the  preceding  facts,  it  is  possible  to  give  to  coal  gas  ita 
highest  illuminating  power.  The  burners  are  either  simple  beaks  perforated  with  a 
small  round  hole,  or  circles  with  a  series  of  holes  to  form  an  argand  flame,  as  shown  in 
fig,  684,  or  two  holes  drilled  obliquely,  to  make  the  flame  cross,  like  a  swallow's  tail,  oi 
with  a  slit  constituting  the  sheet  of  flame  called  a  bat's  wing,  like  most  of  the  lamps  in 
ths  streets  of  London.  These  burners  are  mounted  with  a  stopcock  for  regulating  the 
quantity  of  gas. 

The  height  of  the  flame,  which  with  like  pressure  depends  upon  the  size  of  the  orifice, 
and  with  like  orifice  upon  the  amount  of  pressure,  the  latter  being  modified  by  the  stop- 
cock, is,  for  simple  jets  in  the  open  air,  as  follows : — 

2  3 

55-6        100 

60-5     101-4 

109 


Length  of  Ihe  flame 
Intensity  of  the  light 
Volume  of  gas  consumed    - 
Light  with  equal  consumption 

When  the  length  exceeds  five  inches,  nothing  is  gained  in  respect  to  light.    For  oil 


100 


4 

5 

6  inches. 

150 

197-8 

247.4 

126-3 

143-7 

182-2 

131 

150 

IdO 

686 


eas  the  «iame  statements  will  serve,  only  on  account  of  its  superior  richness  in  carbon,  i1 
does  not  bear  so  long  a  flame  without  smoke.     Thus: 

Length  of  the  flame  -  1  2  3  4  5  inches. 

Intensity  of  the  light  -        22        63-7  96-5  141  178 

Gas  consumed  -         -     331         78*5  90  1J8  153 

Light  with  equal  consumption  100  122  159  181  174 

The  diameter  of  the  orifice  for  single  jets,  or  for  several  jets  from  the  same  beak,  is 
one  twenly-eiahlh  of  an  inch  for  coal  gas,  and  one  forty-fifth  for  oil  gas. 

When  several  jets  issue  from  the  same  burner,  the  light  is  improved  by  making  all  the 
flames  unite  into  one.     In  this  case  the  heat  becomes   greater,  for  the  combined   flame 
presents  a  smaller  surface  to  be  cooled,  than  the  sum  of  the  smaller  flames.     The  advan- 
tage gained   in  this  way  may  he  in  the  ratio  of  3  to  2,  or  50  per  cent.       In  an  argand 
burner  the  distances  of  the  orifices  for  coal  gas  should  be  from  JJL  to  -^S-  of  an  inch 
and  for  oil  gas  ^l^^.    If  the  argand  ring  has  10  orifices,  the  diameter  of  the  central  open- 
ing should  be  =  --i^  of  an  inch;  if  25  orifices,  it  should  be  one  inch  for  coal  gas;  but 
for  oil  gas  with  10  orifices,  the  central  opening  should  have  a  diameter  of  half  an  inch, 
and  lor  20  orifices,  one  inch.    The  pin  holes  should  be  of  equal  size,  otherwise  the  larger 
ones  will  cause  smoke,  as  in  an  argand  flame  with  an  uneven  wick.     The  glass  chimney 
is  not  necessary  to  promote  the  combustion  of  an  argand  coal  gas  flame,  but  only  to  pre- 
vent It  from  flickering  with  the  wind,  and  therefore  it  should  be  made  so  wide  as  to 
exercise  liille  or  no  influence  upon  the  draught.     A  narrcw  chimney  is  necessary  merely 
to  prevent  smoke,  when  a  very  strong  light  with  a  profusion  of  gas  is  desired.  '  Oil  gas 
burned  in  an  argand  beak  requires  a  draught  chimney,  like  a  common  argand  lamp,^on 
account  of  the  large  quantity  of  carbon  to  be  consumed.      The  most  suitable  mode  of 
regulating  the  degree  of  draught  can  be  determined  onlv  by  experiment,  and   the  best 
construction  hitherto  ascertained  is  that  represented  in  Jig.  685.     Fig.  686  exhibits  the 

view  from  above,  of  the  rim  or  ring  c,  upon  which 
the  chimney  6  stands,  and  which  surrounds  the  per- 
forated beak.  The  ring  is  made  of  open  fretwork, 
to  permit  the  free  passage  of  air  upwards  to  strike 
the  outside  of  the  flame.  The  thin  annular  dsic  rf, 
Q  685  which  is  laid  over  its  fellow  disc  c,  in  the  bottom 
of  the  chimney-holder,  being  turned  a  little  one  way 
or  other,  will  allow  more  or  less  air  to  pass  through 
for  promoting,  more  or  less,  the  draught  or  ven- 
tilation. The  draught  in  the  central  tube  of  the 
•  burner  may  be  regulated  by  the  small  disc  e,  whose 
diameter  is  somewhat  smaller  than  that  of  the  ring 
of  the  burner,  and  which,  by  turning  the  milled 
head/,  of  the  screw,  may  be  adjusted  with  the  greatest  nicety,  so  as  to  admit  a  greater 
or  smaller  body  of  air  into  the  centre  of  the  cylindrical  flame. 

In  mounting  gas-lights,  and  in  estimating  beforehand  their  illuminating  eflfects,  we 
must  keep  in  mind  the  optical  proposition,  that  the  quantity  of  light  is  inversely  as  the 
square  of  the  distance  from  the  luminous  body,  and  we  must  distribute  the  burners 
accordingly.  When,  for  example,  a  gas-light  placed  at  a  distaace  of  ten  feet,  is  required 
for  reading  or  writing  to  aflford  the  same  light  as  a  candle  placed  at  a  distance  of  twa 
feet;  squaring  each  distance,  we  have  100-4;  therefore  15.0  _  25,  shows  us  that  25 
such  lights  will  be  necessary  at  the  distance  of  10  feet. 

Concerning  portable  gas-light,  with  the  means  of  condensing  it,  and  carrying  it  from 
the  gas  woii<s  to  the  places  where  it  is  to  be  consumed,  we  need  say  nothing,  as  bv  the 
improvements  lately  made  in  the  purification  and  distribution  of  coal  gas,  the  former 
system  has  been  superseded. 

It  is  well  known  that  light  gas  deteriorates  very  considerably  by  keeping,  especially 
when  exposed  to  water  over  an  extensive  surface ;  but  even  to  a  certain  degree  over  oil, 
or  in  close  vessels.  An  oil  gas  which  when  newly  prepared  has  the  specific  gravity  of 
1-054,  will  give  the  light  of  a  candle  for  an  hour,  by  consuming  200  cubic  inches ;  will, 
after  two  days,  give  the  same  light  by  consuming  215  cubic  inches  per  hour;  and  after 
fou-  Jays,  by  consuming  240  cubic  inches  in  the  like  time.  With  coal  gas  the  deieriora 
tion  appears  to  be  more  rapid.  When  newly  prepared,  if  it  afl!brds  the^  light  of  a  candle 
with  a  consumption  of  400  cubic  inches  per  hour,  it  will  not  give  the  same  light  after 
being  kept  two  days,  except  with  a  consumption  of  430  inches ;  and  after  four  days,  of 
460.  Oil  gas  three  weeks  old  has  become  so  much  impaired  in  quality  that  600  inches 
of  it  were  required  i>er  hour  to  furnish  the  light  of  a  candle.  All  light  gas  should  be 
nsed  therefore  as  soon  as  possible  after  it  is  properly  purified. 

Economical  consideration's. — The  cost  of  gas-light  depends  upon  so  many  local  cir 
cumstances,  that  no  estimate  of  it  can  be  made  of  general  application ;  only  a  fev. 


f 


860 


GAS-LIGHT. 


leading  points  may  be  stated.  The  coals  required  for  heating  the  retorts  used  to  constitute 
one  half  of  the  quantity  required  for  charging  the  retorts  themselves.  When  five  retorts 
are  healed  by  one  fire,  the  expenditure  for  fuel  is  only  one  third  of  that  when  each  retort 
has  a  fire.  The  coke  which  remains  in  the  retorts  constitutes  about  60  per  cent,  of  the 
weight  of  the  original  coal ;  but  the  volume  is  increased  by  the  coking  in  the  proportion 
of  100  to  75.  When  the  coke  is  used  for  heating  the  retorts,  about  one  half  of  the  whole 
is  required.  If  we  estimate  the  coke  by  its  comparative  heating  power,  it  represents  65 
per  cent,  of  the  coals  consumed.  One  hundred  pounds  of  good  coal  yield  in  distillation 
10  pounds  of  ammoniacal  liquor,  from  which  sulphate  or  muriate  of  ammonia  may  be 
made,  by  saturation  with  sulphuric  or  muriatic  acid,  and  evaporation.  The  liquor  con- 
tains likewise  some  cyanide  of  ammonia,  which  may  be  converted  into  Prussian  blue  by 
the  addition  of  sulphate  of  iron,  after  saturation  with  muriatic  acid. 

Two  hundred  pounds  of  coal  afford  about  17  pounds  of  tar.  This  contains  in  100 
pounds  26  pounds  of  coal  oil,  and  48  pounds  of  pitch.  The  tar  is  sometimes  employed  as 
a  paint  to  preserve  wood  and  walls  from  the  influence  of  moisture,  but  its  disagreeable 
smell  limits  its  use.  The  coal  oil,  when  rectified  by  distillation,  is  extensively  employed 
for  dissolving  caoutchouc  in  making  the  varnish  of  waterproof  cloth,  and  also  for  burning 
in  a  peculiar  kind  of  lamps  under  the  name  of  naptha.  Oil  of  turpentine,  however,  is 
often  sold  and  used  for  this  purpose,  by  the  same  name.  If  the  coal  oil  be  mixed  with 
its  volume  of  water,  and  the  mixture  be  made  to  boil  in  a  kettle,  the  mingled  vapors  when 
passed  through  a  perforated  nozzle  may  be  kindled,  and  employed  as  a  powerful  means 
of  artificial  heat.  The  water  is  not  decomposed,  but  it  serves  by  its  vapor  to  expand  the 
bulk  of  the  volatile  oil,  and  to  make  it  thereby  come  into  contact  with  a  larger  volume 
of  atmospherical  air,  so  as  to  burn  without  smoke,  under  a  boiler  or  any  other  vessel. 
The  pitch  may  be  decomposed  into  a  light-gas. 

The  relative  cost  of  light  from  coal  gas  and  oil  gas  may  be  estimated  as  one  to  six  at 
least.     Rosin  gas  is  cheaper  than  oil  gas.     See  Rosin. 

I  shall  conclude  this  article  with  a  summary  of  the  comparative  expense  of  different 
modes  of  illumination,  and  some  statistical  tables. 

One  pound  of  tallow  will  last  40  hours  in  six  mould  candles  burned  in  succession,  and 
costs  8d. ;  a  gallon  of  oil,  capable  of  affording  the  liirht  of  15  candles,  for  40  hour^, 
costs  5*. ;  being  therefore  ^  of  the  price  of  mould  candles,  and  J^-  of  the  price  of  <ii\».i. 
The  cost  of  wax  is  about  85  times  that  of  tallow;  and  coal  gas,  as  sold  at  the  rate  of 
9s.  for  1000  cubic  feet,  will  be  one  sixth  the  price  of  mould  candles ;  for  500  cubic  inches 
of  coal  gas  give  a  light  equal  to  the  above  candle  for  an  hour ;  therefore  40  X  500  .  ~ 
20,000  cubic  inches  =  1 1  57  cubic  feet,  worth  Ijd.,  which  multiplied  by  6  gives  7|d., 
the  average  price  of  mould  candles  per  pound. 

The  author  of  the  article  Gas-light  in  the  Encyclopsedia  Britannica,  observes,  in  refei 
ence  to  the  economy  of  this  mode  of  illumination,  that  while  the  price  of  coal,  in  cons**- 
quence  of  the  abundant  and  regular  supply  of  that  article,  is  liable  to  little  fluctuation, 
the  cost  of  wax,  tallow,  and  oil,  on  account  of  the  more  precarious  nature  of  the  sources 
from  which  they  are  obtained,  varies  exceedingly  in  different  seasons.  "Assuming  that 
a  pound  of  tallow  candles,  which  last  when  burned  in  succession  forty  hours,  costs  nine- 
pence"  (seven-pence  halfpenny  is  the  average  price),  *'  that  a  gallon  of  oil,  yielding  the 
light  of  600  candles  for  an  hour,  costs  two  shillings"  (five  shillings  is  the  lowest  price  oi* 
a  gallon  of  such  oil  as  a  gentleman  would  choose  to  bun.  in  his  lamp),  "  that  the  expense 
of  the  light  from  wax  is  three  times  as  great  as  from  tallow,  and  that  a  thousand  cubic 
feet  of  coal  s^as  cost  nine  shillings ;"  he  concludes  the  relative  cost  to  be  for  the  same 
quantity  of  light, — from  wax,  100;  tallow,  25;  oil,  5;  and  coal-gas,  3.  I  conceive  the 
estimate  given  above  to  be  much  nearer  the  truth ;  when  referred  to  wax  called  100,  it 
becomes,  for  tallow,  28-6  ;  oil,  14*3  ;  coal-gas,  4*76. 

Gas-lighting  has  received  a  marvellous  development  in  London.  In  the  year  1834,  the 
number  of  gas  lamps  in  this  city  was  168,000,  which  consumed  daily  about  4,200,000 
cubic  feet  of  gas.  For  the  purpose  of  generating  this  gas,  more  than  200,000  chaldrons, 
or  10,800,000  cubic  feet  of  coals  were  required. 

For  ihe  following  valuable  statistical  details  upon  gas-light,  my  readers  are 
indebted  to  Joseph  Hedley,  Esq.,  engineer,  of  the  Alliance  Gas  Works,  Dublin ;  a 
gentleman  who  to  a  sound  knowledge  of  chemistry,  joins  such  mechanical  talent  and 
indefatigable  diligence,  as  qualify  him  to  conduct  with  success  any  great  undertaking 
committed  to  his  care.  He  has  long  endeavored  to  induce  the  directors  of  the  London 
gas-works  to  employ  a  better  coal,  and  generate  a  more  richly  carbureted  gas,  which  m 
much  smaller  quantify  would  give  as  brilliant  a  light,  without  heating  the  apartments 
unpleasantly,  as  their  highly  hydrogenated  gas  now  does.  Were  his  judicious  views 
adopted,  coal  gas  would  soon  supersede  oil,  and  even  wax  candles,  for  illuminating  pri- 
vate mansions. 


GAS-LIGHT. 


861 


Copy  of  a  paper  laid  before  a  Committee  of  the  House  of  Commons,  showing  not  only 
the  relative  values  of  the  Gases  produced  at  the  undermentioned  places,  but  showing  in 
hke  manner  the  relative  economy  of  Gas,  as  produced  at  the  different  places,  over  can- 
dies.     By  Joseph  Hedley,  Esq. 


^-g 


Nuiiies 

of  the  Places 

where  experiments 

were  made. 


Birmingham  ;  1 
Birmingham  and  I 
Staffordshire  ;  j 
two  Companies  J 


pa 
Stockport  - 
Manoti  ester 
Liverpool       Old 

Company  t 
Liverpool  New 

Gas  Comjiany 
niadfoid    • 
].e<-d!i 
Sheffield    - 
Leicester  - 
Nottingham 
Derby 
Preston 

London 


*■"      -     w 

ao^-  2  fi  §  ^ 


Z  be  9i 


-   op  <u  « 


fc.'C 
GO   n 

-     *      I      QC  O 
3  ;_    «    -    U 

—         O 


Equal  to 
Candles. 


2-572 

3-254 
3000 

2-369 

4-408 

2-190 
2-970 
2-434 
2-435 
l-fi45 
1  937 
2136 

^083 


on   V 


a  i- 


li  a  s 


■  Ai  ^*^  at 

.1^  CO  5 
=  S  c  =  I  «s  =<=>  « 

(A     ^      w     ^^    '  *»m  ..^     n        *"   ^ 


'  "2 ' 


.C    '"   -"    i  I    !"    -3 


JZJS 


Cubic  Feet. 
1-22 

•85 

-825 

11 

-9 

1-2 
■855 
1-04 
11 
1-3 
1-2 
1  15 

1-13 


O 


a  3 


Cubic  Feet. 


2704 

1489 
1536 

2646 

1164 

3123 
1644 
2440 
2575 
4200 
3521 
3069 

3092 


-«i 

V 
«    95  >~ 

I-    0    0 

*-   hn  =  -»- 

?'l 

Gas 
atin 
lbs. 
lies. 

—    CO 

>?  =0 

,S  "o 

0 

P  -z  0 
^-=- 

s.  d. 

L.  s.  d. 

10  0 

1    7    0 

10  0 

0  )4  11 

8  0 

0  12    3 

10  0 

1     6    5 

10  0 

0  11    8 

9  0 

1    8    1 

8  0 

0  13    2 

8  0 

0  19    6 

7  6 

0  19    3 

9  0 

1  17    9 

10  0 

1   15    4 

10  0 

1  10    8 

10  0 

1  10  11 

s  • 
5-5 

•of 


C3 


_j  *  ® 
si  M 

fc-      —      ^ 


O" 

v..  ■"■  oi 

CSV 

-2=3 
8  =  5 

u  a 
^  I" 


Percent:,  L.    $.    d. 


9 

121 

Hi 

6i 

6i 

4 
15 

15 

15 

15 

none 

allowed 


1    4    7 

0  13    0 

0  lU  10 

1  4    9 

0    9  10 


1  4 
0  12 
0  18 

0  16 

1  11 
1  10 
1    6 


I  10  11 


5? 

tea 
u 

a. 


•541 

•539 
-534 

•462 

•580 

•420 
•530 
•466 
-5-28 
•424 
•448 
•419  t 

-412 


*  }^  ''"'.-  *'^  ca»<'l«s  are  csliniHted  to  burn  5700  hoars,     t  The  candles  cost  3/.  2s.  6<i. 

t  1  he  Liverpool  Old  Company  have  since  resorted  to  the  use  of  Cannel  coal,  and  consequently  very  nearly 

BSimilate  to  the  T.ivomon     Mo«r  /-„.„„«...,  ;..  :n ; .; ^  ^  J  ucaiijr 


■ -,-  — .-J     .....v>     oiB.v^^     t\a\wm\.\j     Hf    1,110     UOT3    \fl 

assimilate  to  the  Liverpool  New  Company  in  illuminating  power. 


Memorandum.— It  will  not  fail  to  be  observed  that  in  deducing  the  comparative  value 
between  candles  and  gas  by  these  experiments,  the  single  jet^and  in  every  instance, 
ol  course,  it  was  the  same)  has  been  the  medium.  This,  however,  though  decidedly 
the  most  correct  way  of  making  the  comparative  estimate  of  the  illuminating  power  of 
the  several  gases,  is  highly  disadvantageous  in  the  economical  comparison,  inasmuch 
as  cas  burnt  in  a  properly  regulated  argand  burner,  with  its  proper  sized  glass,  air 
aperture,  and  sufficient  number  of  holes,  gives  an  advantage  in  favor  of  gas  consumed 
in  an  argand,  over  a  jet  burner,  of  from  30  to  40  pur  cent.  At  the  same  lime  it  must 
not  be  overlooked,  that  in  many  situations  where  great  light  is  not  required,  it  will  be 
lound  far  more  economical  to  adopt  the  use  of  sinsle  je's,  which,  by  means  of  swin<» 
brackets  and  light  elegant  shades,  becoinne  splendid  substitutes  for  candles,  in  banking 

^  establishments,  offices,  libraries,  &c.  &c. 

Note.— In  Glasgow,  Edinburgh,  Dundee,  Perlh,  and  the  Scotch  towns  generally,  the 
Parrot  or  Scotch  Cannel  coal  is  used ;  in  illumiaatmg  power  and  specific  gravity  the 
gas  produced  i«  equal  lo  that  from  the  be?t  J^s.-ription  of  Cannel  coal  in  England 
The  price  per  1000  cubic  feet  ranges  about  9.-.,  with  from  5  to  30  per  cent,  off  for  dis^ 
cotmts,  leaving  the  net  price  about  9s.  to  hi-,  equal  in  the  above  table  to  100  lbs  of 
candles. 


Epitome  of  E.xperiments  made  in  Gas  prc^Iucc-:  from  different  qualities  of  Coal  and 
consumed  in  different  kinds  of  Burners:  ' 

Tried  at  the  Sheffield  Gas  Light  Company's  Works,  and  laid  before  a  Committee  of  the 

House  of  Commons.     By  Joseph  Hedley,  Esq. 


Ditfe 
1835. 

May 
8 
9 
9 

8 

9 

9 

Description 
of  Burner. 

Species  of 
Coal. 

> 

1° 

Distance  of 

Candle  from 

Shadow. 

Gas  consumed 
per  Hour. 

^0 

Equal  lo  Mould 
T.-tllow  Can- 
dles, 6  to  the 

pound, 9  inches 
long  each. 

Gas  equal  to 

100  lbs.  of 

Mould  Candles. 

Cost  of  Gas 

at  8*.  per  1000 

cubic  feet. 

§^  ^  a 

Sins^le  Jet 
Ditto 
Ditto 
Arg'and     ) 
14  holes   1 
Ditto 
Ditto 

Deep  Pit 

Mortormley 

Cannel 

Deep  Pit 

Moitormley 
Cannel 

•410 
-450 
•660 

•410 

-450 
-660 

Inches 
75 
74 
61J 

34 

33 
29 

Cubic 
Feet. 
1- 
•95 

•7 

3-3 

3  1 

2-6 

Inches 
4 
4 
4 

3.1 
3| 

Candles. 
2-36 
2-434 
354 

1153 

12-24 
1.5-85 

Cubic 

Feet. 

2415 

2224 

1127 

1631 

1443 
935 

L.  s.     d. 

0  19    3§1 
0  17    9i 
0    9    0 

0  13    Oi  ' 

0  11     6i 

0    7     53J 

L.    3.    d. 
3     2     6 

862 


GAS-LIGHT. 


Copy  of  Experiments  made  at  the  Alliance  Gas  Company's  Works  in  Dublin,  during  lh€ 

past  year  1837.     By  Joseph  Hedley,  Esq. 

Results  of  experiments  on  the  qualities  of  various  coals  for  the  production  of  gas;  its 
value  in  illuminating  power;  produce  of  coke,  and  quality ;  and  other  particulars  impor- 
tant in  gas-making : — 

1st  Experiment,  Saturday,  May  27,  1837.— Deane  coal  (Cumberland),  2  cwts.  of  112 
lbs.  each  (or  224  lbs.)  produced  970  cubic  feet  of  gas;  4  bushels  of  coke  of  middling 
quality  ;  specific  gravity  of  the  gas,  475.  Consumed  in  a  single-jet  burner,  flame  4 
inches  high,  Ij^^lhs  cubic  feet  per  hour;  distance  from  shadow  76  inches,  or  2-3 
mould  candles.  Average  quantity  of  gas  made  from  the  charge  (6  hours)  4-33  cubic  feet 
per  lb.,  or  9,700  cubic  feet  per  ton  of  20  cwts.  Increase  of  coke  over  coal  in  measure,  not 
quite  30  per  cent.  Loss  in  weight  between  coal,  coke,  and  breize  56  lbs.,  converted 
into  gas,  tar,  ammonia,  &c.  « 

2d  Experiment,  May  28.— Carlisle  coal  (Blenkinsopp).  224  lbs.  produced  1010  cubic 
feet  of  gas,  4  bushels  cf  coke  of  good  quality  though  small;  increase  of  coke  over  coal  in 
measure  not  quite  30  per  cent.  Loss  in  weight,  same  as  foregoing  experiment.  Average 
quantity  of  gas  made  from  the  charge  (6  hours)  4-5  cubic  feet  per  lb.  or  10,080  per  ton. 


Illuminating  power  of  the  Gas. 


i 


Consumed 
per  hour, 
single  jet. 

Distance 
from  cuiidle. 

Equal 
to  cuiidles. 

Specific 

giavily. 

At  the  end  of  the  first  hour 

Ditto          ditto          with  20-hole  ) 

argand  burner       -         -            5 
When  charge  nearly  off      - 
When  charge  quite  off,  with  20-  > 

hole  argand  burner        -         -  \ 

feet. 
5 
9 

inches. 
70 

25 

85 

100 

2-72 
21-33 
1-84 
notl 

•475 
•475 
•442 
•266 

3d  Experiment,  May  29.— Carlisle  coal  (Blenkinsopp).     112  lbs.  produced  556  cubic 
feet  of  gas.     Other  products,  loss  of  weight,  &-c.,  same  proportion  as  foregoin<'  experi- 
ment.    Average  quantity  of  gas  made  from  the  charge  (6  hours)  496  cubic  feel  per  lb 
or  J  1,120  per  ton  '* 

In  this  exj)eriment  the  quantity  of  gas  generated  every  hour  was  ascertained  •  the 
illuminating  power,  the  specific  gravity,  and  the  quantity  of  gas  consumed  by  the  s'in'^le 
jet  with  a  flame  4  inches  high,  was  tried  at  the  end  of  each  hour,  with  the  respective 
gases  generated  at  each  hour ;  and  the  following  is  a  table  of  results. 

RESULTS. 


Consumed 

Hour. 

Gas  producred. 

\if\  hour, 
per  single  jet, 

Specific  gravity. 

Distance  of 
candle  from 

Illuminating 
power  equal  to 

4  inches  high. 

shadow. 

mould  candles. 

cubic  feet. 

cubic  feei. 

inches. 

1st. 

150        j 

lU-lOths    > 
or  1-15      J 

•534 

70 

2^72 

2d. 

120 

11 

•495 

75 

2-36 

3d. 

95 

12 

•344 

75 

2-36 

4th. 

95 

15 

•311 

80 

2-08 

5th. 

80 

17 

•270 

85 

1-81 

6th. 
Total 

16 

29 

•200 
feet  9  inches. 

100 

not  one 

556   or 

92ior2 

92i 


115 


Average  of  the  above  gas,  6-hour  charge. 
16-lOths,  nearly         '359  81 

Average  of  the  above  gas  at  4-hour  charge. 
12|-10ths,  -421  76 


203 


2^36 


Troduction  of  gas  in  6  hours  556  feet,  or  at   he  rate  of  11,120  cubic  feet  per  ton. 
Ditto  in  4  hoars  460  feet,  or  at  the  rate  of    9,200  ditto 


GAS-LIGHT. 


863 


The  relative  value  of  these  productions  of  gas  is  as  follows,  viz. : 
11,120  at  16-lOths  per  hour  nearly  (or  1-5916  accurately),  and  equal  to  203  candles; 
the  11,120  feet  would  be  equal  to  and  last  as  long  as  1597  candles,  or  2661.  lbs.  of 
candles. 

9200  at  12J-10ths  per  hour  (or  12375  accurately),  and  equal  to  236  candles;    the 
9200  feet  would  be  equal  to  1949  candles,  or  324^  lbs.  candles. 
Now  2661  lbs.  of  mould  candles,  at  7s.  6d.  per^dozen  lbs.,  will  cost  8/.  6s.  4|d.,  whilst 
3245  lbs.  of    do.        do.        at  7s.  6d.  per    do.  do.  10/.  3*. 

Showing  the  value  of  4-bour  charges  over  6-hour  charges ;  and  of  9,200  cubic  feet 
over  11,120  cubic  feet. 

Note. — 9500  cubir  feet  of  Wijran  cannel  coal  gas  are  equal  in  illtuninating  power  to  859  l-6th  lbs  of  can- 
dles, which  at  7s.  6d.  per  dozen  lbs.  will  cost  25/.  lOs.  b^d.  It  is  also  found  that  any  burner  with  superior 
gas  will  consume  only  about  half  the  quantity  it  would  do  with  coinmou  gas. 

ith  Experiment,  May  30th. — Cannel  and  Cardiff  coal  mixed  |  and  |,  together  112  lbs., 
produced  460  feet  of  gas;  2  bushels  of  coke  of  good  quality;  increase  of  coke  over  coal 
in  measure,  about  30  per  cent. ;  loss  in  woight,  41  lbs. ;  coke  weighed  71  lbs.,  no  breize. 
Average  quantity  of  gas  made  from  the  <-.  irge  (4  hours;,  4-1  cubic  feet  per  lb.,  or  9-200 
per  ton. 

Illuminating  power. — At  the  end  of  the  first  hour. 

Caudles. 
Distance  of  candle  from  )  -yo  nr  9  AQ  5  Consumed  per  hour,  single 
shadow      -        -        _^'^oTz^if^      jet,  4  inche*  high       ^- 
At  end  of  2d  hour,  do.       70  or  2-72      Do.         do.         do. 
At  end  of  3d  hour.         This  gas  very  indifferent. 
Average  of  the  three      -    70  or  2-72      Do.        do.        do. 
Specific  gravity  3-44;  5  feet  per  hour,  with  a  20-hole  argand  burner,  equal  to  14-66 
candles. 

blh  Experiment,  May  3Ut. — Carlisle  coal,  112  lbs.   produced  410  feet  of  gas;    other 
products,  same  as  in  former  experiments  with  this  coal,  but  heat  very  low. 
Illuminating  power  and  produce  of  gas. 

''Average  of  this  gas:  specific  gravity,  540; 
distance  of  candle  from  shadow,  55  inches, 
or  4-4  candles  consumed  per  single  jet, 
9-lOths  of  a  cubic  foot  per  hour.    20-hole 


Cubic  feet. 
12-lOths. 
ll|-10lhs. 

ll|-10ths. 


flsi  hour  120  cubic  feet 

^'""•^^     To 

{  4th  100 


< 


argand  burner,  4  feet  per  hour,  equal  to 
21-33  candles. 

It  is  possible,  from  the  superior  quality  of  this  gas,  that  a  little  of  the  cannel  gas  made 
for  a  particular  purpose,  may  have  got  intermixed  with  it  in  the  experimental  gasholder 
and  apparatus. 

A  variety  of  other  experiments  were  tried  on  different  qualities  of  coal,  and  mixtures 
of  ditto,  too  tedious  to  insert  here,  though  extremely  valuable,  and  all  tending  to  show 
the  superior  value  of  gas  produced  at  short  over  long  charges ;  and  also  showing  the  im- 
portance and  value  of  coal  producing  gas  of  the  highest  illuminating  power;  among 
which  the  cannel  coal  procured  in  Lancashire,  Yorkshire,  and  some  other  counties  o£ 
England  and  Wales,  and  the  Parrot  or  splent  coal  of  Scotland,  stand  pre-eminent. 

Note. — In  all  the  foregoing  experiments  the  same  single-jet  burner  was  used  ;  its  flame  in  all  instances 
exactly  4  inches  high. 

The  coal  when  drawn  from  the  retort  was  slaked  with  water,  and  after  allowing  some  short  time  toi 
drying,  was  weighed. 

A  Table  of  the  number  of  hours  Gas  is  burnt  in  each  month,  quarter,  and  year. 


, 

. 

. 

^ 

a 

Xi 

4) 

>. 

>» 

C9 

3 

3 

3 

Time  of  Burning. 

•s 

s 
2" 
< 

•" 
M 

3 
U 

O 

> 

« 

U 

Q 

cs 

3 

a 

s 

u 

fa- 

< 

^ 

S 

6 

s 

3 
»-3 

ii 

a- 
u 

"3    C 

-3 

Total 
year 

o'clock. 

From  dusk  to  6 

— 

— 

2 

.11 

02 

80 

65 

33 

4 

_ 

___ 



2 

173 

102 

277 

** 
y 

—            7 

— 

14 

22 

02 

4-3 

111 

90 

61 

31 

4 



_ 

4 

30 

205 

18S 

493 

3 

—             8 

— 

40 

."42 

93 

122 

142 

127 

89 

62 

28 

4 

_ 

32 

92 

.3.17 

278 

7.59 

O 

—            9 

13 

71 

82 

121 

152 

173 

158 

117 

93 

58 

29 

8 

95 

106 

449 

308 

1078 

.-: 

—            10 

44 

10-2 

112 

155 

182 

204 

1.S9 

145 

124 

88 

60 

38 

ISO 

2.'iS 

.541 

4.58 

1443 

!d:= 

—            11 

75 

133 

142 

180 

212 

235 

220 

173 

155 

118 

91 

68 

277 

3.')0 

633 

548 

1808 

~  s 

—           12 

106 

104 

172 

217 

242 

206 

251 

201 

186 

148 

1S2 

9H 

.•?08 

442 

725 

638 

2173 

All  night 

217 

307 

345 

421 

473 

527 

512 

411 

382 

295 

24S 

195 

732 

809 

1421 

1305 

4327 

-3    9 

Morning  from  4 

— 

16 

48 

80 

no 

137 

137 

98 

71 

28 

« 

30 

04 

327 

306 

727 

5g 

—            5 

— 

— 

18 

49 

80 

106 

106 

70 

40 

3 

_^ 

3 

IS 

235 

216 

472 

Kfi 

—            6 

— 

— 

— 

18 

50 

75 

75 

42 

9 





143 

126 

269 

Im 

--            7 

1 

20 

44 

44 

14 

~~' 

—^ 

^~ 

~"^ 

~~' 

64      58 

122 

!^ 

864 


GAS-LIGin\ 


Copy  of  a  Paper  submitted  to  a  Committee  of  the   House  of  Commons  in   the   Session  of  ISW, 

of  England ;  and  procured  by  actual  Survey  and 


I 


1 

No.  of 

Name  of  the 
Place  where 

Price  of  Gas  per  Meter, 

Price  of  Coal, 

and 
Description ; 
delivered  per 

Ton. 

Coks 
made  frora 
a  Ton  of 

Coal. 

Selhn; 
Price  of 

Ma- 
terial 
usual  to 

Quail- 
used 

Public 

or 
Street 

Descnption. 

Price 
paid  per 
Anpum 

Who  ti^U, 
cleans,  putseMi 

Gas  Works 
are  uiiuited. 

and  Discounts  allowed. 

^2- 

Coke. 

heat 
Retorts. 

per  Ton 
of  Coal. 

Lamps 
sup- 

Bise or  Sort. 

for 
Ditto. 

and  repairs. 

i 

1 

plied. 

Cu./t. 

L.  ».  d. 

Birmingham 
Can  Com- 

10*. per  meter  cub.  feet. 
Di«coiiiits 

Lump  coal 

6,500 

33 

8«.  Id   per 

Slack. 

About 

490 

Batswings. 

1  10    0 
8    0    0 

Company,  and 

from  West 

bushels. 

quarter 

5  cwt. 

460 

provides  poata* 

pany. 

10/.    to      30/.  s   i'}   . 

Bromwich 

delivered, 

of  slack. 

ID 

services,  &^. 

30/.    to      SO/.*   4    c 

pits,  risen 

or  about 

at  6s. 

50/.    to      75/.  t  7i  S 

much  of  late. 

3d.  per 

per  ton, 

75/.     to     I00/.**I0    t 

1837,  lU.  lOd. 

bushel. 

25  per 

Brming'ham 

100/.  &-  upwards  15    »• 
10*.  permetercub.  feet. 

From  West 

6,500 

24  bush. 

2s.  lOd. 

Slack. 

cent. 
5  cwt. 

1,500 

Batswings. 

averare 

i    la      A 

Ditto. 

and  Staf- 

Discounts as  above. 

Bromwich 

but  larger 

per  sack 

and 

of  slack. 

1  18    0 

fordshire. 

pits,  1837, 
9s.  3d. 

measure 
than  Bir- 
mingham. 

of  8 
bushels. 

Tar. 

at  4«. 

25  per 
cent. 

Macclesfield. 

10«.  per  meter  cub.  feel. 

Discounts 

50/.       ,      75/.     5 

75/.  -  ^  100/.     7,  • 

•100/.  5^   125/.  10  = 

0  125/. -3  t  I5'V,   laiS 

<jisn/.  2  S  175/.  15"  i 

175/.       »>  200/.   I7ic- 

Common,  8s. 
average  1834. 

6,720 

IS  cwt. 

lOs. 
per  ton. 

Coke. 

No 

account 

kept. 

ISO 

Ditto. 

a  10  0 

Company* 

Stockport. 

200/.itiipwards20 
10*.  permeier  c'lb.  feet. 

Coal   10s.  6d. 

7,800 

7  cwt. 

6s.  8d. 

Coal, 

Ditto. 

830 

Ditto 

I     0 

1«K. 

Comm.  proTida 

Di»cu'iitssame  as  Mac- 

cannel 194.6<f. 

per  ton. 

coke. 

lamps  &,  posts. 

clesfield.  Macclesfield 

about  hall  and 

and  tar. 

8    0    0      Company's 

discounts  taken  from 

half  used. 

1837.       service  light. 

Siockncrl  card. 

Averasre  15«. 

repair,  clean, 
and  extinguish. 

1834. 

Manchester. 

10».  per  m. cub. ft.  1834. 

15*.  2d. 

9,500 

14  cwt. 

Ditto. 

Coke. 

4,  t-lds 

S,375 

Single  Jets 

1    8    0  CoiiiiaissiaaK's 

3i.  anil  8i.     —      1837. 

average. 

cwt. 

and  tlat 

8    0    0 

ul  polic*. 

Discounts 

Oldham    )- 

flames. 

50/.            100/.      2  J 

Water-   f  = 

about  half 

100/.     S     laO/.      5     . 

eaie      L  S 

and  half. 

150/.    -g     Son/.      7}  = 

Wigan     y  " 

SfMM.     5     225^.     in    S 

Mixed,  1834. 

225/.    -3     250/.     mi 

250/.     5     300/.     15"  eu 

300/.            400/.     17i 

Liverp'l    Old 

400/.  &  upwards  20 
10*.  per  iiieier  cub.  feel. 

7s.3d.  perton 

8,200 

HI  cwt. 

8s.  4d. 

Slack, 

Siewt. 

1,700 

Batswings. 

4  10    0 

Company 

Coinpany, 

Discounts 

of  112  lbs.  per 

» 

per  ton  of 

7s.  8d. 

30 

IJet, 

S    5    0  light,  clean,  pMt 

1834 

10/.  &.  imder  50/.  i\^ 

30/.     to          100/.  5  « 

100/.     to          200/.  7Jt 

cwt.     Orms- 

kirk  or  Wig- 

an  slack. 

1121b. 
per  cwt. 

per  ton. 

8    — 

3  - 

4  — 

2  13    0  out,  and  repair 

3  8    9j                   ^ 
3  13  11 

Ditto,  ditto. 

300t  and  upwards  10   * 
111  IS35,  tlii3  Company 

resorted  to  the 

use  of 

cannel   Co 

at   similar 

to  the  L 

iverpool 

New  G 

as  and  Coal 

Company,    pro<1ucinf 
4    0    0,Cominissioner» 

Liverpool 
Nevk'  Gas  and 

IDs.  per  me'.er  cub.  feet. 

18*.  all  cannel 

9,500 

13  cwt. 

7«.  6d. 

Coke 

5^  cwt. 

Only  a 

Argands. 

Dincoiiiits  same  as  Liv- 

Wigan. 

per  ton. 

and 

few. 

1 

Cole,  1833. 
Brndlord, 

erpool  Old  Comp'ny. 
9«.  per  meter  cubic  feet 

8».6d.  perton. 

8,000 

IS  cwt. 

12«. 

slack. 
Coke. 

8|cwt. 

no 

Batswings 

8  IS    2  Company  liglit. 

1644. 

to  larw'e  consumers. 
Discounts 

3  sorts  used 
average. 

per  ton. 

repair,  &e. 

20/.      to      30      5 

Slack  &t.  6d. 

30/.      to      40      7J  ^ 

Low  moor 

40/.      to      60    10     S 

8s.  lOd. 

60.'.      to      80     li'i  Z 

Catherine 

8C/.       to     100     15     * 

slack  8s. 

100/.  (tup  wards  80 
Small  Consumers, 

lOs.  per  meter  cub.  feet, 
and    5    per    cent,    off 

from  10/.  to  SOi. 

Leeds,   834. 

i».  per  meter  cu'oii  feet. 

Discounts 

a;  )  percent.   (    15/. 

5'  f     on  l:alf-   >    30/. 

7)  {     yearly     )    SO/. 

10    J  payments.  (  100/. 

St.  per  ton 

averajsi. 

S-3ds.  cola  to 

7s. 

l-3d  cannel 

10«. 

6,500 

Itcwu 

7*.  6d. 
per  ton. 

Ditto. 

5|fwt. 

517 

DKo. 

8  18    6 

CominissiaMn.j 

except  extin-  • 

guishing,  for   1 

which  Comp'ny 

pay  3*.  lOil  per 

lamp. 

Sheflie'd. 

8».  piT  meter  cubic  feet. 

7».9d.  perton 

8,000 

10  cwt. 

I0«. 

Ditto. 

IJcwt. 

aoo 

Ditto. 

S  10    0 

Compar.7 

1836. 

Disc'nts  same  as  Leeds. 

average. 
3  sorts  used, 

1,  S-lOihs 
caii'el.at  16*. 

8,  2-IOths 
deep  pit   7s. 

l-lOili 
silkslone,  lOs. 

of  saleable 
coke. 

oer  ton. 

pr>  vide   lampa,j 
clt   n,  repair,   i 
pu.  out,  &c. 

Lcirester, 

7s.  6d.  per  meter  cub.ft. 

I3»-.  6d. 

7,500 

4  quarters 

10«.  8d. 

Coke, 

About 

44 

Ditto. 

1  18    6 

Compao)  light. 

1837 

Disc'nls  on  half-yearly 

averatfe. 
Derbyshire 

or  t*.  8d. 

tar,  &c 

1-Sd  of 

put  out,   «d 

rental,  not  exceeding 

perqr. 

cc.ke. 

clean. 

10/.,  5  per  rent. 

soft  coal. 

10/.  „  V,  20/.     7\    . 

«20/.   £■=   30/.    10     S 

>30/.    -"3   40/.    Iti   S 

-=40/.   =  S   50/.    IS     u 

<50/.    *g   60/.   20     %, 

60/.&.upwards95 

Derby.  1834. 

10*.  per  meter  cub.  feet. 

Discounts 

i  to  35  per  cent. 

Same  coal 
used  as  at 
Leicester. 

7,000 

Ditto. 

Ditto. 

Coke. 

Ditto. 

tI9 

Ditto. 

8    8    0 
8    7    0 

Commissionert 
light,  put  out, 

&.C. 

Nottingham, 

9».  per  meter  cubic  feet. 

Ditto. 

7,000 

Ditto. 

Ditto. 

Ditto 

Ditto. 

300 

BItto. 

8    8    0 

Commiasioncra 

1834. 

Discouuu  as  above. 

light,  clean, 
repair,  &c. 

London,  1834 

ie».  permetercub.  feet. 
No  discounts. 

17».  average. 
Newcastle. 

8,500 

26  bush. 

12*.  ytet 
chaldron. 

Ditto. 

11  bush. 

86,880 

Ditto 

4    0    0 

C  >n»patMr  tight,! 
Cl'^ll,  fttt  ou*. 

b—  9V  repi.ir 

Uitto.UI7. 

Dhto 

Ditto. 

8,500 

Ditto. 

Ditto. 

Ditto. 

Ditto. 

80.400 

Ditto. 

4    0    0 

-»  "^ 

GAS-LIGHT. 


865 


b<>Ag  a  Synopsis  of  the  proceedings  of  the  undermentioned   principal  (ras-Light   Establishmeata 
Experiments  between  the  Years  1831  and  1837.    By  Joseph  rlediey,  Elsq. 


no.  of  Hours, 

orTime    i.iiii 

■ji  liie  Ifsii. 


Gas 

con- 
sumed 
in  each 
Lamp 

per 
Hour. 


u  w 

S.Z 
O 


S2S  nights  or 
8^33  hutirs,  9 
iiioiiths,nmit- 
ting  5  nights 
for  moons. 


8-^4  nights,  or 
304S  liours. 


8  months, 
omilliii|r  5 
nights  h>r 


8  months,  4 
nights  omit- 
tedfor  moons. 
837  nights— 
ttOO  hours. 

1390  hours. 


1000  hours. 


nearly  similar 
8000  hours. 


Smooths, 

emitting  7 
Ibirhu.     8000 

oours  to  4 
o'clock  in  the 

moruing. 


5  feet 
hour. 


Ditto. 


4  feet 
hour. 


Ditto. 


I  foot. 

8  feet, 

per 

hour. 


"  =  S  • 

"3*-    -  9 

IS  Vol 


«.  d. 

30  10 
40  18 


1    3i 


8    0 


t.    d. 

18    0 


8330  hours. 


8800  hours. 


From  August 

14th  to 

September 

1st,  omitting 

I  nights  for 

aoons,  3000 

hours. 


SITS  hours, 
from   August 

to  May. 
All  the  year, 

4887  hours 


5  feet 
hour. 


results. 

Si  feet 

per 

hour. 

(feel 

hour. 


8    6 


6    6 
5    6 


4    4 


which 
5    6 


S    1 


18    0 


18    0 


IS    6 


nothin° 


4  feet 

I.P" 
hour. 


Ditto. 


Sfeet 

per 

hour. 


Ditto. 
Ditto. 


f    S 


s   >i 


>  4I 


IS    0 


see. 
nothing 


IS    6 


S  10 


IS    0 


7    0 


4887  horirs,  t 
all  tba  jiar.  j     per 
bour 


4    0 

nearly 

I    0 

nearly 

4  feet      4    3 


Ditt*. 


Oitta. 


4   til 


Per  Centage  of 
Loss  of  Gas  made. 


Receives  net 

about  6*.  8d.  per 

meter  cubic  feet. 


Receives  net 
about  St.  6d.  per 
meter  cubic  feel. 


Could  not  say. 


Ditto. 


About  IS  to  I7i 

per  cent  receive 

about  7t.  4d.  per 

meter  cubic  feet, 

public  and 

private. 

Nearly  all  by 

meter. 


Could  not  learn 

in  the  absence  of 

the  manager. 


Nearly  all  by 
meter. 

Receive  8s.  per 

meter  cubic  teel, 

less  5|  per  cent 


.3    0 


11    0 


Receive  for  public 

and  private  OS.  8d. 

per  meter  cubic 

feet.    Public  5*. 

private  7* ;  meters 

used  5  to  1  for 

private  rental. 

Receive  for  public 

and  private  Its.  5«. 

per  meter  cubic 

feet.     Public 

S«.  Std.,  private 

5«.  9\d.    Few 

meters  used. 


Not  sufficiently 
long,  at  7«.  6d. 


Lose  about  17| 
per  cent. 

Could  not  learn. 


Receive  for  public 

and  private  lights 

7«.  public,  ii. 

private,  8«.  fe\ 

meters  used. 

Ditto. 


Greatest 

Quantity  of 

Gas 

delivered 

in  One 

Night. 


Cubic  Feet. 
48  millions 
in  the  year. 


85  millions 
in  the  year. 


80,000. 

Total  for 

year  about 

IS  millions. 


65,000. 
Total  for 
year  about 
18  millions. 


500,000. 
Total  for 

year  100 
millions. 


360,000. 
Total  for 

year  72 
millions. 


Not  suffi- 
ciently long 
at  work. 
48,500. 
Total  for 

vear 
8,^19,000. 


176,000. 
Total  for 

year  81 
millions. 


aso,ooo. 

Total  for 

year  40 

rnillioiis. 


Total  for 
year  18 
millions. 


Ditto. 


Ditto. 


Total  for 

year  1000 

millions. 

Longest 

night 
4.910,000. 
Total  for 
year  1400 
millions. 
Longest 

night 
7,180,000. 


Duration 

of 
Charges. 


Method 

of  Purifi. 

cation. 


6  hours. 


Ditto. 


8  hours. 


Ditto. 


6  hours. 


3  hours, 
large 

retorts, 
hoMing 

6  cwt. 

each. 

4  hours. 


Dry  lime. 


Ditto. 


Ditto. 


Ditto. 


Wet  lime. 


Wet  and 
dry  lime, 
prin- 
cipally 
dry. 


Wet  lime. 


Number  of 

Gas 

Holders. 


4,  and  8  in 

the  town, 

and  large 

new  gas 

station. 


6,  and  6  in 
the  town  7 
miles  off. 


3ga8 
holders. 


4  gas 
holders. 


10  gas 

holders,  and 

8  in  the 

town. 


8  gas 

holders  in 

all,  4  in  tb« 

town,  1000 

yards  off  the 

works. 


8  hours.    Dry  lime 


6  hours. 


Ditto. 


Ditto. 


Ditto. 
Ditto. 
Ditto. 

Ditto. 


Ditto. 


Ditto. 


Ditto. 


Wet  lime 
Ditto. 
Ditto 

Ditto. 


8  large 
gas  holders. 

4gas 
holders. 


o 

Is 


Q. 
OQ 


•453 


<-  1 
oOE) 

a  o 


o.z  <-< 


9 
*^   U 

o  ^ 

3  ^ 

—  c 

j;  3 
—  o 


iii 


=  5  "^ 


5  f-~   =-i 


um 


•455 


Not 
taken 


•539 


•534 


86S 


•580 
•4K) 


hoi' 


1^1 


lers. 


4  gas 

holders, 

and  8  more 

erscting. 


8  gas 

holders,  and 
I  erecting 


4  gas 
holders. 


IIO  gas 
holders. 


176  gas 
hohurs. 


Inch, 
72 


JCarf/M 
1,929 


,c  o 
OS 

CuTrt. 

1-28 


c 

Cu./t. 
•8 


70 


64 


66 


75 

M 

78 


•530 


•466 


•588 


1,989,    l-n  I       -8 


804    Not 
taken 


8,441 


•85 


=  25 
•  cr 
Inch. 


*i 


M 


2,295    •SSS  ;   '475 


1,777 


SM 


I'l 


8,306.       -9 
1,6481      n 


67 


74 


74 


•448 
•424 

•418 

•418 


63 

90 
60 

80 


8,888 


1,836 


•8M 


1,886 


104 


M 


1,453 


1,884 


Ik 
•t 


\U 


f  ••• 

w 
I 


>l 


•7» 


1-8      -M 


I  8  ' 1  i7S 


l,53li    1-iS  I       84 


l^ 


8 
8 

n 


II 


•84 


r  ( 


SG6 


GAS-LIGHT. 


II 


> 

e 
a 


D 
O 

0) 

o 

3 

o 


2  6- 


I    >^    .««    «_    .^*i    k  _     «w%    aMk  X.     ^     *  * 


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GAS-LIGHT. 


Bffr 


Tbials  of,  and  Experiments  on,  various  Kinds  of  Coal  as  regards  the  Production  o 

Gas  from  each,  and  its  Quality  or  Illuminating  Power;  by  Joseph  Hedley,  Esq.,  Co»- 

sulting  Gas  Engineer,  London. 

Note.— In  ail  the  experiments  the  gas  was  passed  through  a  governor,  on  a  pressure  of  5  lOths  of  «■ 
Inch. 

1.       8.       3.        4.        &       ft.  7.  &  9.      la    IL      IX    13.    14.    IS.    1&    If. 


Haine  and 

«   or   Tube   with- 
Oths    of   an  Inch,! 
ight  of  Flame.        j 

1 

a 

-J 

o  o 

'•S 

>. 

X 

1 

St 

Equal  in 
Illuini- 

s ;  outer  Diameter 
nch ;     inner    ditto 
Holes    40th   of  an 
Distances    apart, 
;  full  Illuminating 
Candles;  consum- 

itli  30  Holes ;  outer  Diame- 
Inch ;  inner  ditto  7-8  of  an 
oles  40th    of  an   Inch   Di- 
Distances  apart,    llOth  of 
full    Illuminating    Power 
36  Candles;   Consumption 

i 

i 

"a 
a 

9 

^ 

i 

i 

1 

Description  of 

?;^x 

fL 

S<H 

S, 

^1 

nating 

u 

"§ 

:; 

•g 

•o 

^ 

^ 

Coal. 

o 

E 

3 

a 

Power 
to 

-•S        5        3  3 

s 

I 

(0 

15 

3S 

o 

S 

;s 

i 

1 

t 

J3  O  *> 

S 

o 

S 

o 

o 

I" 

ffO*  <0  !-• -<  ft"  t) 

5  I.  t-l  C        3  '- 

11 

H 

tn 

w 

-< 

< 

o   . 

H 

^.ti 

i 

U.J 

«i  J 

«rf 

• 

■s«; 

UU 

s«> 

•J  J 

11 

n 

Inch's 

^u 

pd 

-^i 

^8 

Candle* 

Cubic  Feet 

Cubic  Feet. 

?§ 

n.S 

3 

•^^ 

•§8 

■ss 

■i^ 

ui* 

a 

oi* 

0&. 

«,li 
», 

o>* 

K 

ot* 

o"^ 

oh. 

w«* 

u»* 

§►.; 

Lismabago,  or 

Glaagow  Can- 

f 

nel   -    •    •    • 

91to2a 

13 

li 

12-1 

7-3 

2-77 

B-8 

3-9 

•737 

101 

l» 

39 

37 

33 

11 

< 

1 

Hewcaatle  coal 

18 

16 

16-2 

ll-l 

1-76 

6- 

7-5 

.476 

104 

30 

30 

18 

16 

16 

« 1 

Welsh  Cannel 

23 

11 

9 

131 

71 

3- 

«• 

8- 

•737 

103 

s 

60 

30 

30 

8 

1 

Pelaw,     New- 

castle Coal  • 

18 

16 

»^ 

16-1 

HI 

1-75 

»• 

7-5 

•444 

1(» 

3 

S9 

30 

17 

14 

« 

Pclton,  ditto  - 

18 

16 

16-3 

U-3 

1-73 

6* 

7M 

.437 

103 

3 

38 

20 

19 

14 

6 

Bickers  talf,  Li- 

' 

verpool   ditto 

19 

14 

ei 

16-3 

111 

3-04 

4-e 

6-S 

.476 

103 

3, 

30 

34 

18 

10 

4 

Wigan  Caanel 

S3 

11 

» 

131 

7.2 

3- 

8- 

3- 

.606 

100 

^k 

38 

30 

18 

4 

Blenkinsopp, 
Carlisle  Coal 

• 

27 

16 

?» 

161 

11-1 

1-87 

4-6 

7. 

•631 

100 

3 

98 

84 

18 

10 

Neath  Coal  - 

18 

16 

191 

121 

W6 

6-23 

7-5 

•468 

100 

3 

96 

81 

SO 

18 

» 

Note.— The  candle  here  used  was  a  composition  candle,  with  plaited  wick,  requiring  no  snuffing 
firing  at  least  one  third  more  light  than  mould  tallow  candles. 

Attention  to  the  preceding  tabular  statement  of  experiments  is  important,  as  exhibit- 
ing several  very  important  facts,  particularly  interesting  at  this  moment  to  the  science 
of  gas-lighting,  and  now  for  the  first  time  made  public. 

It  will  not  fail  to  be  observed  by  these  experiments  that  all  the  coals  produced  nearly 
equal  quantities  of  gas,  notwithstanding  the  variable  characters  and  qualities  of  this 
coal.  The  greatest  quantity  produced  being  at  the  rate  of  11*648  cubic  feet  per  ton  of 
20  cwt.,  the  smallest  1 1'200  cubic  feet.  All  these  experiments  were  performed  with  the 
greatest  care,  and  under  precisely  similar  circumstances  as  to  pressure,  manufacture,  &e., 
&.C.  The  time  in  which  the  quantity  of  gas  is  produced  from  the  several  coals  varies  con- 
siderably, and  deserves  notice,  as  it  most  materially  affects  the  economy  of  production 
— that  coal  being  the  most  valuable,  all  other  things  being  alike,  which  yields  or  gives  oat 
its  gas  in  the  shortest  time ;  and  particular  attention  is  claimed  to  this  fact.  For  the 
more  ready  reference  to  the  table  the  columns  are  numbered.  No.  11  exhibits  this 
difference,  and  it  will  also  be  seen  by  this  column  that  the  time  varies  as  the  quaiUf 
of  the  coal,  the  best  coal  yielding  its  gas  in  two  hours,  and  the  worst  in  three  hours. 

Another  most  important,  material,  and  interesting  fact  is  established  by  these  experi 
ments— that  the  fiow  of  gas  is  as  its  density — demonstrated  by  the  variation  in  the 
heights  of  the  flames,  as  shown  in  column  No.  1,  being  18  inches  in  the  inferior  gase* 
to  22  inches  in  the  superior;  while  the  quantity  of  gas  required  to  supply  these  flamea 
is  in  the  inverse  ratio  of  their  heights,  the  longer  flame  requiring  but  twelve  cubic  feet 
to  maintain  it,  when  the  shorter  flame,  from  the  inferior  gas,  required  sixteen  cubic  feet. 
See  column  No.  2. 

Remarkable  as  this  difference  in  the  heights  of  the  flames  and  the  consumption  is 
it  is  not  so  great  as  the  difference  caused  by  the  quality  or  illuminating  power  of  the 
several  gases,  shown  by  columns  Nos.  5  and  6 ;  where  it  will  be  seen  that  the  consump* 
tion  of  the  best  gas  per  hour  was  only  ^-  of  a  cubic  foot,  and  its  light  was  equal  to 
3  candles,  while  that  of  the  worst  gas  was  |,2  ©f  a  cubic  foot,  and  its  lights  equal 
only  to  1*75  candles,  or  nearly,  the  best  to  the  worst,  as  1  to  3. 

The  next  column.  No.  7,  exhibits  similar  results  as  to  the  superior  value  or  illumina. 
ting  power  of  one  gas  over  another.  In  this  case  an  argand  burner  was  used.  The 
best  gas  required  only  two  feet  to  be  equal  to  twelve  candles,  while  the  inferior  required 
five  feet  to  be  equal  to  the  same. 

And  in  column  No.  8,  in  which  another  and  superior  argand  burner  was  used,  the 
best  gas  required  only  three  feet  to  be  equal  to  twenty-five  mould  candles,  while  the 
inferior  required  seven  and  a  half  feet :  from  this  it  results  that  the  7^  cubic  feet  of 


898 


GAS-LIGHT. 


I 


inferior  gas,  to  be  equal  to  the  8  feet  of  good  gas,  should  have  given  light  equal  to 
nxty  two  and  a  half  candles,  whereas  they  only  gave  light  equal  to  ttoenty-Jiw  candles, 
to  great  is  the  difference  in  the  qualitus  of  gas  for  jn-oducing  light. 

Whilst  on  the  subject  of  the  illuminating  power  and  the  value  of  one  gas  over 
another,  it  will  not  fail  to  be  observed,  by  the  table,  that  another  great  difference 
also  exists,  caused  by  the  use  of  particular  burners ;  as,  for  example,  the  best  gas  in 
column  No.  6.,  where  the  single  jet  was  used,  required  teventenths  of  a  cubic  foot  to 
be  equal  to  three  candles,  whilst  the  same  gas  in  column  No.  7.,  where  a  20-hole 
argand  burner  was  used,  required  only  two  feet  to  be  equal  to  twelve  candles ;  and  in 
column  No.  8.,  where  a  30-hole  argand  burner  was  used,  only  three  feet  were 
required  to  be  equal  to  twenty-Jive  candles ;  demonstrating  the  fact  that  a  great  and 
extraordinary  improvement  in  the  quantity  of  illuminating  power  is  effected  by  the 
simple  increase  or  enlargement  of  the  burner,  affording,  where  great  light  in  one 
position  is  required,  a  most   extraordinary  economy  in  the  use  of  gas,  shown  in  fact 

Sractically  by  the   recent  introduction  of  the   celebrated  "Bude"  light,  patented  by 
[r.  €k>ldsworthy  Gurney. 

Tabular  Statkmknt,  deduced  from  the  foregoing  Experiments,  showing  the  Cost  of 
Candles  to  produce  as  much  light  as  9,000  Cubic  Feet  of  Gas  would  afford,  being 
the  Product  of  One  Ton  of  Coal.  (The  candles  are  moulds,  6  to  the  pound,  9 
inches  long,  and  each  candle  is  calculated  to  burn  9^  hours.  Cost  of  Candles  lyL 
per  pound,  or  7».  6d  per  dozen  pounds.) 


CWdlw  would  eeat,  to  be  «qiiiTaIent  to 

Where  a  single 

Jet  Earner  it 

lued. 

Where  a  30-hole 

Argand  Burner 

is  used. 

WherBa30-bole 

Argand  Burner 

is  used. 

Where  a  Bude 

Burner  is  used, 

according  to 

Slatement  of 

Company. 

Common  coal  gas     ------ 

Qood            do.    -----.-    - 



£  s.   d. 

10  18     6 
25  18    4 

£  H.   d. 
15  15    8 
89    9    6 

£  «.    d. 
21  18    e 
54  16    7 

£   ».    d. 

59    8    7 

148    0    9 

Tablk,  also  deduced  from  the  foregoing,  showing  the  Cost  of  Gas  at  the  several 
Prices  undermentioned,  and  equivalent  to  100  lbs.  of  Mould  Candles,  coatinjr 
Zl  2«.  6(1  * 


•fG^. 

If  burnt 

in  a 

Single  Jet 

Oaa  «qiial 

to  100  lbs. 
of  Mould 
Gindles. 

Gas  would  cost  at 
per  thousand 
Cubic  Feet. 

If  burnt  in 
a  30-hole 
Argand 
Bam«>r, 

Qa»  equal 

to  1(10  lbs. 

of  Candlrs. 

Qm  would  eoet  at 

per  thousand 

Cubic  Feet. 

If  burnt  in 

a  80-hole 

Argnnd 

Burner, 

Gas  equal 

to  100  lbs. 
of  Cai.dles. 

Oaa  would  eoet  at 
per  thoussdd 
Cubic  FeeU 

Oommon 
Good     - 

Cubic  te«t. 

h,. 

Is. 

9«. 

Cubic  feet. 

6«. 

It. 

9t. 

Cubic  Feet. 

6s. 

7*. 

»«. 

2,687 
1,072 

t.    d. 

13  5 
6  4 

t.  d. 

18  9 

7  5 

(.    d. 

24  2 

9  7 

1,781 
712 

8  10 
8    6 

t.  d. 

12    5 

4  11 

I.  d. 

16  0 
64 

1,282 
513 

«.    d. 

6  5 

2  7 

t.    d. 

8  11 
3    7 

«.  d. 
11  « 

4  7 

I  have  received  from  Mr.  Hedley,  an  engineer  of  great  eminence  and  experience, 
plans  and  drawings  of  gas  works  and  of  apparatus  of  the  most  approved  and  modem 
construction,  and  on  the  very  largest  scale  as  to  extent  of  business  or  manufacture :  also 
plans  and  drawings  of  a  gas  work  on  a  smaller  scale,  with  its  corresponding  apparatus. 
In  the  first,  or  large  work,  purification  by  wet  lime,  before  described,  is  used;  in  the 
latter,  by  dry  lime. 

The  large  work  referred  to  is  calculated  for  and  is  arranged  to  contain  400  retorts,  12 
wet-lime  purifiers,  and  2  washers;  12  large  double  or  telescopic  gasholders,  capaHe  of 
storing  1,000,000  cubic  feet  of  gas ;  and  coal  stores  capable  of  holding  10,000  tons  of 
coaL 

The  smaller  work  is  calculated  for  and  will  contain  40  retorts,  2  dry-lime  purifiers, 
and  a  wash  vessel ;  2  gas-holders  capable  of  storing  50,000  cubic  feet  of  gas ;  and  coal 
stores  sufficient  for  1000  tons  of  coaL 

Fig.  687.  is  the  side  elevation  (front  view)  of  a  gas  work  capable  of  containing  400 
retorts,  and  all  their  dependencies. 

Mg.  688.  is  the  plan  of  the  retort  house,  coal  stores,  tanks,  gas-holders,  Ac,  on  the 
largest  scale  and  most  approved  form,  viz.,  a  the  retort  house,  300  feet  long,  56  feet 
wide ;  b,  retort  beds ;  c,  chimney  stack ;  d,  flues ;  k,  hydraulic  mains ;  f,  coal 
stores,  each  300  feet  long,  30  feet  wide;  g,  condensers;  h,  engine  houses;  j,  wash 
vessels;  k,  purifiers  and  connections;  l,  lime  store  and  mixing  tub;  m,  smiths' 
and  fitters'  shop;  n,  refuse  lime  pits;  o,  meter  houses;  p,  tar  tank;  q,  tanks,  gas- 
holders, bridges,  columns,  valves,  and  connections ;  a,  governors ;  a,  coke  stores ; 
T,  inlet  pipes ;  v,  outlet  pipes ;  w,  house  and  offices  ;  x,  stores. 


GAS-LIGHT. 


;  Fig.  689.    TntDsverse  sectioo  and  elevatioo  of  a  bed  of  6  d  retorts ;   a,  transyerse 
Mction  ;  b,  elevatiop. 


«87 


J  fi 


-5v 


i 


1 


I 


870 


GAS-LIGHT. 


Fig.  690.    Longitudinal  section  of  a  bed  of  6  d  retorts. 

Fig.  691.  Elevation  of  an  upright  air  condenser,'  consisting  of  6  chambers,  with  ft 
series  of  10-inch  pipes. 

J^^.  692.  Elevation  of  a  double  or  telescopic  gas-holder,  of  a  modem  and  approred 
form,  with  part  of  tank. 


GAS-LIGHT. 


871 


688 


tig.  693.    End  elevation  and  plan  of  air  condenser ;  a,  end  elevation ;  b,  plan. 

^g.  694.  Set  of  8  wet-lime  purifiers  and  wash-vessels  in  elevation  and  section,  with 
feed-heads,  agitators,  valves,  ana  connections,  raised  for  the  lime  liquor  to  run  from  one 
purifier  to  the  next  below  it,  and  ultimately  into  the  refuse  lime-pits,  viz.  a,  section  of 
wash- vessel ;  b,  section  of  purifier ;  o,  elevation  of  purifier. 


Fig.  695.    Front  elevation  of  gas  works  on  a  smaller  scale,  where  dry  lime  is  used. 

Fig.  696.  Plan  of  gas  works,  consisting  of,  viz. :  a,  retort  house;  b,  retort  beds; 
C  chimney  stack ;  d,  flue ;  s,  hydraulic  main ;  r,  coal  store ;  o,  lime  store ;  h, 
w»*hor  and  purifiers ;  j,  store ;  k,  tar-tank ;  l,  horizontal  condenser  laid  on  the 
p'-jund  ;  M,  inlet  pipe;  n,  outlet  pipe;  o,  tanks  and  gas-holders;  p,  meter  and 
f  rernor ;  q,  smith's  shop ;  r,  office ;  8,  coke  store. 


87SI 


GAS-LIGHT. 


GAS-UGHT. 


873 


11^ 


f 


Fig.  697.    Elevations  and  sections  of  dry-lime  purifiers ;  a,  longitudinal  elevatioa ;  b 
ditto  section ;  c,  transverse  elevation ;  d,  ditto  sectioa 


London,  Manchester,  Liverpool,  Birmingham,  Chester,  Bristol,  Ac.  <&&,  in  all  which 
places  lie  has  erected  gas-works.  To  this  gentleman's  genius  and  skill  the  public 
are  mainly  indebted  for  many  valuable  improvements  in  the  application  of  gas  from 
coal  to  purposes  of  illumination. 


693 


'^  y= 


I  am  well  convinced  that  a  distribution  and  arrangement  of  gas-works,  combining 
eflbctiveness,  economy,  convenience,  and  elegance,  at  all  equal  to  the  preceding,  havs 
never  before  met  the  public  eye,  in  this  or  any  other  country. 


H^ 


Ih  the  brief  description  of  the  meter  given  in  this  Dictionary,  I  omitted  to  state, 
that  this  most  ingenious  scientific  contrivance  for  measuring  aeriform  or  gaseous  fluids 
as  they  flow  through  pipes  is  the  invention  of  Samuel  Clegg,  Esq.,  Civil  Engineer,  of 


l<  • 


WH 


GAS-LIGHT. 


Brought  up  m  ihe  great  engineering  establishment  of  Messrs  Boulton  and  Watt. 
^L  K^'T"  ^^*;?"»g^*?^'  he  became  connected  with  Mr.  Wm.  Murdoch,  who  moet 
rrZr!.1?/^.T/K  w'''*'*''  ^*^^<>"g»°»t<»-  of  gas-lighting,  as  the  evidence  given  before 
»  Committee  of  the  House  of  Commona  in  the  year  1809  abundantly  verified.     H« 


II  i 


GAS-LIGHT. 


87ft 


demonstrated  that  the  light  produced  from  gas  was  superior  in  economy  to  all  other 
modes  of  artificial  illumination;  and  by  tfeat  evidence,  though  so  long  "back  as  1809, 
it  will  be  seen  that  all  the  information  of  the  present  day  was  even  then  known  to  him, 
dearly  pomted  out,  and   illustrated  by   his   experiments,  which   strangely  contrasted 


876 


GAS-LIGHT. 


GAS-LKJHT. 


877 


Fig.  62.  Elevations  and  secUons  of  dry-Ume  purifiers;  A,  longitudinal  elevaUoB 
U;  ditto  section ;  C,  transverse  elevation ;  D,  ditto  section. 


697 


^ 

B 

S2 

o           

1 

1 

_i                  ^ 

o 

..,<;> ^ 

• 

1 

K 

.    .      t 

1- 

-?- 


llL 


Jl 


"With  the  statements  put  forward  by  the  parties  then  attempting  to  introduce  this  mode 
of  lighting  into  the  metropolis.  All  the  ephemeral  plans  of  those  parties,  have,  how- 
ever, long  since  disappeared,  or  nearly  all.  One,  unfortunately,  remains,  and  that  a 
most  unlucky  one— the  unprofitable  manufacture  of  coke  in  gas-making— an  article 
worthless  in  the  scale  of  value,  which  should  never  have  been  sought  for.  Messrs. 
Watt  and  Murdoch  predicted  that  when  the  parties  became  incorporated  by  Par- 
liament, they  would  resort  to  their  apparatus,  notwithstanding  their  repudiation  of  it 
at  the  time,  alleging  their  own  schemes  to  be  so  much  superior ;  and  they  verified  this 
prediction  a  very  few  years  afterwards  by  engaging  the  services  of  Mr.  Clegg,  to  extri- 
cate them  from  their  manifold  and  egregious  errors.  He  began  by  introducing  the  very 
apparatus  of  Messrs.  Murdoch  and  Watt,  so  inconsiderately  condemned  by  them. 

Mr.  Clegg  put  up  the  Jirst  gas-holder  ever  erected  in  London. 

To  Mr.  Clegg  is  due  also  the  introduction  of  lime  for  the  purification  of  the  gas, 
without  which  gas-lighting  would  to  this  day  have  afforded  little  comfort  and 
economy.  The  hydraulic  main,  for  separating  the  gas  making  from  the  gas  made, 
valves,  lutes,  and  many  other  admirable  contrivances,  are  peculiarly  due  to  Mr.  Clegg. 
But  the  crowning  performance  of  all  his  inventions,  was  that  for  measuring  out  the  gas 
to  the  several  parties  rec^uiring  it  exactly  according  to  their  demands.  The  manu- 
facture of  gas  having  by  this  time  been  so  far  mechanically  perfected  as  to  be  brought 
to  our  doors,  it  became  at  once  apparent  that  some  contrivance  should  be  found  by  the 
use  of  which  every  person  might  consume  as  much  or  as  little  gas  as  he  pleased,  paying 
only  for  what  he  really  used,  thus  making  science  subservient  to  fair  dealing. 

Mr.  Clegg  took  out  a  patent  for  the  gas  meter  about  the  year  1814 ;  but  great  as 
its  merits  were,  he  soon  found  that  serious  difficulties  remained  to  be  overcome,  in  in- 
ducing parties  to  support  and  encourage  its  use,  even  where  their  interests  should  have 
prompted  them  to  adopt  it.  Mr.  Clegg  had,  however,  fortunately  associated  with  him, 
towards  the  completion  of  the  apparatus,  Mr.  Samuel  Crosley ;  and  by  their  joint 
labours  it  acquired  its  present  precision. 

The  value  of  the  meter  is  primarily  to  the  gas  companies,  next  to  the  public.  By 
its  use,  the  gas  companies  are  enabled  to  supply  gas  to  all  places  where  light  is  re- 
quired, at  a  rate  proportioned  to  its  just  value.  The  public  thereby  see  the  economy 
afforded  by  gas  over  candles,  oil,  or  other  material ;  but  they  gain  also  in  another  most 
important  way— by  the  use  of  the  meter,  gas  companies,  being  duly  i*id,  are  eiwbled 
to  reduce  the  price  of  gas,  and  yet  realite  e^'\tal  projits,  thus  bringing  it  within  the  reach 


of  a  much  larger  class  of  the  community ;  and  it  is  a  well  established  fact  that  in  towni 
where  gas  is  sold  by  meter,  gas  companies  can  and  do  sell  at  nearly  one  half  the  price 
they  otherwise  could  do. 

Reduction  of  price  increases  demand ;  increased  demand  increases  profits ;  increased 
profits  again  enable  prices  to  be  reduced ;  and  again,  reduced  prices  increase  the  demand, 
thus  benefiting  reciprocally  companies  and  consumers. 

Notwithstanding,  however,  all  these  advantages,  there  are  not  wanting  persons  whc 
have  set  up  an  outcry  against  the  use  of  the  meter,  by  impugning  its  accuracy,  and  accu- 
sing Ihe  gas  companies  with  fraud  in  charging  by  it.  It  would  be  idle  to  follow  these 
parties  in  their  baseless  allegations.  An  action  for  pirating  it  was  brought  and  tried  in 
the  Court  of  King's  Bench,  in  which  not  only  the  novelty  of  the  machine  was  fully  estab- 
lished, but  its  accuracy  and  usefulness  proved  by  the  ablest  mathematicians,  mechanicians, 
and  chemists  of  the  day ;  and  a  verdict  in  its  favour  obtained.  Subsequently  very  large 
damages  have  been  given  for  the  infringement — in  one  case  as  much  as  5000<.,  and  in  an- 
other, in  the  Court  of  Chancery,  a  decree  was  made  referring  it  to  the  Master,  to  take  an 
account  of  the  profits  made  by  the  use  of  the  meter ;  this  is  not  yet  finally  settled,  the 
Master's  report  finding  6000/.  to  be  due ;  but  this  is  excepted  to  by  the  parties  infring- 
ing :  the  Chancellor,  however,  allowed  the  exceptions  to  be  ai^ued,  only  on  payment  by 
the  infringers  of  4000/.  into  court  to  meet  the  patentee's  law  costs.  These  exceptioiis 
have  no  reference  whatever  to  the  question  of  the  accuracy  of  the  meter,  but  are  simply 
as  to  whether  the  advantages  of  the  meter  were  as  great  as  allowed  by  the  Master. 

The  patent  for  the  meter  expired  about  the  year  1828 ;  since  that  period  numerous 
competitors  have  commenced  making  the  machine. 

Mr.  Clegg  has  recently  obtained  a  patent  for  a  dry  gas-meter,  of  which  the  following 
are  its  advantages  and  construction,  as  described  by  the  very  meritorious  inventor : — 

1.  Working  without  water. 

2.  Working  without  membranes  or  valves. 

8.   Working  without  requiring  the  least  pressure. 

4.   Working  without  interference  with  the  perfect  steadiness  of  the  lights. 

6.   Registering  more  accurately  than  any  other  meter. 

6.  Occupying  only  one- tenth  of  the  space  of  the  common  meters. 

7.  Being  subject  to  little  or  no  wear  and  tear. 

8.  And  being  cheaper. 
J'riees. — For  plain  meters.— 

£  ».    d. 

Three-light  meter  ....    1  12    0 

Six-light         do 2  4     0 

Twelve-light  do.    ....    8  80 

The  highest  numbers  will  be  still  cheaper  in  proportion. 

Ornamental  meters,  appearing  like  handsome  time  pieces,  for  halls,  living-rooms,  com 
mittee-rooms,  offices,  counting-houses,  Ac.,  are  charged  extra,  at  ten  shillings  each  and  np 
wards,  according  to  pattern. 

Description  of  Clegg  s  patent  dry  Gas-meter. 

The  two  ^gs.  698,9.  are  half  the  full  size  of  the  apparatus,  and  the  letters  of  referenot 
are  the  same  in  both. 

B,  B,  Jig.  698.,  represents  a  cylindrical  vessel,  about  three  inches  and  three  quarters 
diameter,  and  four  inches  deep,  being  the  dimensions  of  a  meter  capable  of  measuring 
gas  for  three  burners,  called  a  three-light  meter.  In  this  vessel  are  two  glass  cylinders  F, 
F,  connected  together  by  the  bent  tube  d.  The  cylinders  being  perfectly  exhausted  of  air, 
and  half  filled  with  alcohol,  are  made  to  vibrate  on  centres  e  and  «,  and  are  balanced  by 
the  weight/. 

This  instrument  accurately  indicates  the  excess  of  heat  to  which  either  cylinder  may 
be  exposed,  upon  the  principle  of  Leslie's  differential  thermometer. 

C  is  a  hollow  brass  box,  called  the  heater,  about  four  inches  long,  and  half  an  inch 
broad,  projecting  out  of  the  meter  about  one  inch.  At  a  issues  a  small  jet  of  gas,  which, 
when  inflamed,  gives  motion  to  the  cylinders. 

The  gas  enters  the  meter  by  the  pipe  A,  and  circulates  throughout  the  double  case  B: 
having  passed  round  the  case  B,  a  portion  of  it  enters  the  top  of  the  box  C,  by  the  pipe 
D,  and  passes  out  again  at  the  bottom  by  the  tube  e,  into  the  meter ;  the  rest  of  the  gas 
enters  the  body  of  the  meter  through  holes  in  the  curved  faces  of  the  hoods  EE,  and, 
after  blowing  on  the  glass  cylinders,  passes  to  the  burners  by  the  outlet  pipe. 

To  put  the  meter  in  action,  let  the  jet  a  be  lighted  about  an  hour  before  the  burners 
are  wanted.    In  most  cases  this  jet  will  be  lighted  all  day  ua  a  useful  flame.    The 


878 


GAS-LIGHT. 


hole  a  }4  so  situated  on  the  box  C,  that  whatever  be  the  size  of  the  jet,  a  fixed  tem- 
perature is  given  to  the  box,  that  temperature  depending  on  the  quantity  of  flame  in 


ft 
1 '  > 


ii 


U 


contact  with  the  box,  and  not  at  all  on  the  length  of  the  jet.  The  jet  being  lighted, 
and  the  box  C  thereby  healed,  the  gas  which  passes  through  it  is  raised  to  the  same 
temperature,  and,  flowing  out  at  the  tube  c,  impinges  on  the  glass  cylinder  which 
happens  for  the  time  to  be  lowest;  the  heated  gas  soon  raises  a  vapor  in  the 
lower  cylinder,  the  expansion  of  which  drives  the  liquid  into  the  upper  one,  until  it 
becomes  heavier  than  the  counterpoise/,  when  the  cylinders  swing  on  their  centre,  the 
higher  one  descends,  and  comes  in  the  line  of  the  current  of  hot  gas,  and  the  lower  one 
ascends;  the  same  motion  continues  as  long  as  the  jet  a  burns.  The  same  effect  on 
the  cylinder  is  maintained,  however  the  outward  temperature  may  change,  by  the 
cold  gas,  which,  issuing  from  the  curved  side  of  the  hood  EE,  impinges  on  the  uppei 
cylinder,  ard  hastens  the  condensation  of  the  vapor  which  it  contains. 

The  coU  gas  and  the  heater  vary  in  temperature  with  the  room,  and  thus  counteract 
each  other. 

The  lighting  of  the  jet  a  is  essential  to  the  action  of  the  meters ;  in  order  to  insure 
this,  the  supply  of  gas  to  the  burners  is  made  to  depend  on  it  in  the  following  manner. 
The  pipe  G,  by  which  the  gas  leaves  the  meter,  is  covered  by  a  slide  valve,  which  is 
opened  and  shut  by  the  action  of  the  pyrometer  g  ;  the  pyrometer  is  in  communication 
with  and  receives  heat  from  the  jet,  and  opens  the  valve  when  hot,  closing  it  again 
when  cold. 

The  speed  at  which  the  cylinders  vibrate  is  an  index  of  the  quantity  of  heat  com- 
municated to  them,  and  is  in  exact  proportion  to  the  quantity  of  gas  blowing  on  them 
through  the  pipe  c  and  curved  side  of  the  hoods  EE. 

The  gas  passed  through  the  heater  is  a  fixed  proportion  of  the  whole  gas  passing  the 
meter ;  therefore  the  number  of  vibrations  of  the  cylinders  is  in  proportion  to  the  gaa 
consumed. 

A  train  of  wheel-work,  with  dials  similar  to  thai  used  in  the  common  meter,  regis- 
ters the  vibrations. 

Simplicity,  accuracy,  and  compactness,  are  the  most  remarkable  features  of  this 
instrument,  and  the  absence  of  all  corrosive  agents  will  insure  its  durability. 


GAS-LIGHT. 

Directums  for  fixing  and  using  Clegg^s  patent  dry  Gas-meteru 


879 


Choose  a  situation  for  fixing  the  meter,  where  the  small  jet  of  flame  will  be  of  the 
greatest  use,  such  as  an  office-desk  or  counter,  taking  care  to  screw  the  same  firm  and 
level  on  its  base.  When  the  jet  at  the  top  of  the  meter  is  required  to  be  kept  con- 
stantly  burning  as  a  useful  flame,  press  in  the  brass  knob  at  the  front  of  the  meter,  and 
before  lighting  the  burners  pull  it  out ;  when  the  small  flame  is  not  required,  let  it  be 
lighted  about  an  hour  before  you  want  the  burners  lighted.  Adjust  the  size  of  the 
small  flame  at  pleasure  by  the  screw  h. 

On  the  back  of  each  meter  is  marked  the  number  of  lights  it  will  supply. 

The  inlet  and  outlet  pipes  are  marked  at  the  bottom  of  the  meter. 

The  ((uantity  of  gas  consumed  is  recorded  by  the  index  in  the  usual  way. 

For  testing  Clegg's  patent  dry  Gas-meters. 

Pass  the  gas  through  two  meters  at  least,  and  take  the  mean.  Vary  the  number  of 
lights  at  pleasure,  not  exceeding  the  number  marked  on  the  meter,  and  when  one  or 
two  hundred  cubic  feet  of  gas  have  been  consumed,  compare  the  indices. 

These  meters  are  not  for  measuring  small  fractional  parts ;  but  taking  the  average 
for  any  periodical  consumption,  are  more  accurate  than  any  other  meter. 

Mr.  Thomas  Edge,  of  Great  Peter  Street,  Westminster,  has  contrived  the  following 
meter,  of  which  drawings  are  annexed. 

Fig.  700  is  a  front  view  of  a  three-light  meter,  the  front  pl&te  bemg  removed,  and 
•ome  of  the  parts  shown  in  section  65. 


Fig.  701  is  a  transverse  section  of  the  same.  ^ .  ,   .       , 

The  gas  enters  at  a  into  the  small  chamber  b,  in  the  bottom  of  which  is  a  lever 
valve  (part  of  Mr.  Edge's  patent  improvements),  moving  upon  its  axis  and  attached 
by  the  rod  to  a  metal  float  c,  which  in  the  present  drawing  is  buoyant.  The  object 
of  this  arrangement  is  to  intercept  the  passage  of  the  gas  into  the  meter,  unless  a 
sufficient  quantity  of  water  is  in  it,  that  being  necessary  to  its  proper  action;  the  gas 
then  passes  through  the  inverted  syphon  or  tunnel  into  the  convex  cover,  whence  it 
passes  into  the  chambers  of  the  drum. 

Another  of  Mr.  Edge's  improvements  consists  in  the  cutting  down  of  this  sypnonpipe 
or  tunnel  to  the  proper  water  level,  and  connecting  the  bottom  of  it  to  a  waste  water- 
box  into  which  any  surplus  water  must  fall.  The  importance  of  this  precaution  will  be 
t^een  on  investigating  the  drum,  as  an  excessive  height  of  the  water  will  materially 
interfere  with  the  measurement,  the  quantity  of  gas  delivered  per  revolution  being 
considerably  less.    This,  in  connexion  with  the  lever  valve  and  float,  conhnes  the 


880 


GAS-LIGHT. 


GAS-LIGHT. 


881 


i 


li 


rariJition  of  the  water  levels  within  such  narrow  limits,  that  the  measurement  may  be 
considered  perfectly  just  on  all  occasions. 

^^_^^^^_^__^  The  last  patent  by  Mr.  Edge  is  for  an*  improved 

/  \    II  index,  which  is  composed  of  a  series  of  moving 

j  I  dials,  with  10  figures  upon  each,  one  figure  only  ap- 

I  701  pearing  of  each  series  at  a  time. 

I  This  contrivance  is  very  ingenious,  and  will  no 

I  I  J  doubt  be  applied  to  other  machines,  where  indexes 

(indices)  of  quantity  are  required. 

Recurring  to  Mr.  Clegg,  he  is  also  the  inventor 
of  an  instrument  of  great  value— appropriately 
called  a  "governor."  Its  purpose  is  to  render 
equal  the  height  of  flame  of  the  several  burners  in 
any  house  or  establishment,  and  to  keep  them  so, 
notwithstanding  any,  and  whatever  alteration  may 
be  made  in  the  pressure  at  the  works  or  elsewhere. 
This  instrument  is  perfected,  and  successfully  ap- 
plied, though  it  is  not  so  generally  in  use  as  it 
ought  to  be.  By  the  use  of  this  instrument  a  light 
once  set  at  the  height  desired  will  maintain  that 
height  uniformly,  and  without  the  least  variation 
the  whole  evening;  and  continue  to  do  so  till 
altered. 

Without  this  instrument,  it  is  necessary  to  pay 
attention  to  the  burning  of  gas-lights,  as  their 
heights  are  frequently  affected  by  the  most  trifling 
circumstance,  such,  for  example,  as  their  extinction 
at  the  hour  of  closing  the  shops,  which  makes  a  sen- 
sible diiference  in  the  neighborhood. 
All  these  works  have  prodigiously  increased  in  the  quantity  of  gas  made  and  sup. 
phed.  Since  the  account  in  the  former  edition  of  this  work,  large  additional  manufac- 
tories have  been  erected  by  new  companies,  and  great  additions  made  by  the  old  ones. 
Ihere  are  now  in  the  metropolis  alone  15  public  gas  companies,  having  among  them 
16  gas  establishments.  The  quantity  of  gas  manufactured  by  these  23  gas-works,  and 
supplied  to  the  pubhc  was  during  the  past  year  three  thousand  one  hundred  millions 

Ar.^^.^^  ^^^  °^^^ '  *^^  ^^®  *=°^^  ^sed  to  produce  this  quantity  of  gas  was  at  the  least 
400,000  tons  I 

Baked  clay  retorts  are  very  generally  used  in  Scotland,  and  found  to  be  most  economi- 
cal as  regards  wear  and  tear;  in  London,  however,  they  are  mostly  of  cast  iron. 
T     A    P^^^^^**^^  "P®**  ^^6  retorts  is  caused  principaUy  by  the  use  of  wet  lime,  used  in 
London,  because  the  process  is  less  expensive  and  less  cumbersome  than  dry  lime. 
Wet  lime  can  not  be  used  with  clay  retorts,  owin?  to  this  excess  of  pressure. 

Merit  is  due,  for  enlarging  the  capacities  of  double  gas-holders,  to  the  late 
Mr.  Joshua  Horton,  of  West  Bromwich,  near  Birmingham;  and  to  Mr.  Stephen 
Hutchinson,  engineer  of  the  New  London  Gas- Works,  Vauxhall,  where  they  were  first 
successfully  mtroduced,  and  manufactured  by  .vir.  Horton.  They  have  now  come  very 
generaUy  into  u»:;  throughout  the  kingdom^  and  are  manufactured  by  all  eas-holder 
makers.  "^ 

Separate  gas-holders  are  advisable  and  advantageous,  but  they  are  not  generally 
ased,  except  in  Glasgow,  Manchester,  Birmingham,  Sheffield,  and  a  few  other  places. 

llie  annexed  drawing  represents  Mr.  Croll's  vessels  for  the  purification  of  gas  fVom 
ammonia,  which  is  effected  by  means  of  dilute  sulphuric  acid  applied  between  the  con- 
densers with  the  ordinary  lime  purifiers.  The  vessels  are  made  of  either  wood  or  iron, 
and  lined  with  lead ;  have  a  wash-plate  similar  to  the  wet  lime  purifiers.  The  radi- 
ating bottom  formed  of  wooden  bars,  as  shown  in  the  drawing,  is  for  the  purpose  of 
tupportmg  the  wash-plate  and  distributing  the  gas. 

Fig,  702 :  a,  is  the  inlet  pipe ;  6,  the  outlet  pipe ;  c,  c,  the  tube  with  funnel  for 
introducing  the  sulphuric  acid;  d,  the  first  purifying  vat;  e,  the  second  ditto,  both 
lined  with  lead,  and  which  are  filled  up  to  the  dotted  line  with  the  dilute  acid  •  f  f 
.he  water  supply-pipe ;  g,  g,  the  discharging  cocks. 

Fig.noz  represents  a  ground-plan  of  the  vats,  each  10  feet  in  diameter;  A,  the 
bottom  of  the  middle  ;  B,  the  inlet  of  the  gas ;  C,  the  outlet  of  ditto. 

In  commencing  the  process,  these  vessels  are  charged  with  water  and  sulphuric  acid, 
m  the  proportion  of  seven  pounds,  or  thereabouts,  of  the  latter,  to  100  gallons  of  the 
former.  As  the  acid  is  neutralized  by  the  ammonia  contained  in  the  gas  passing 
through  the  vessels,  the  above  proportion,  as  near  as  may  be,  is  kept  up  by  a  continuous 
dropping  or  running  of  acid,  regulated  according  to  the  quantity  of  ammona  contained 


in  the  gas,  from  a  reservoir  placed  on  the  top  of  the  saturator.    This  mode  of  supplying 
the  acid  is  continued  until  the  specific  gravity  of  the  solution  arrives  at  1170,  or  cloM 


to  the  point  of  crystallization,  after  which  the  supply  of  acid  is  discontinued,  and  the 
liquor  retained  in  the  vessel  until  neutral,  when  it  is  drawn  oflf  and  evaporated,  and 
yields  a  pure  sulphate  of  ammonia. 

This  process  has  been  introduced  at  several  of  the  provincial  gas-works,  the  three 
stations  of  the  Chartered,  the  Imperial,  Phoenix,  &c.,  &c.  Mr.  Croll  is  also  now  in 
treaty  with  several  other  companies  for  its  introduction. 

The  produce — sulphate  of  ammonia — from  the  process,  by  the  gas-companies  using 
It,  now  amounts  to  several  tons  per  week — and  it  may  be  here  mentioned,  as  one  of  the 
advantages  of  science,  that  the  ammonia  so  produced  before  the  adoption  of  this  process 
passed  along  with  the  gas  to  the  consumer,  destroying  rapidly  the  main  pipes,  fittings, 
and  metres,  through  which  it  was  transmitted,  as  well  as  deteriorating  the  illuminating 
power  of  the  gas,  and  producing  a  choky  efl'ect  when  consumed  in  close  apartments.  It  is 
now  employed  as  a  manure,  and  found  to  be  superior  in  its  effects  as  a  fertilizer,  as  well 
as  comparatively  cheaper  than  any  of  the  other  artificial  manures ;  so  that  whether 
Mr.  C.'s  invention  be  looked  upon  as  affecting  improvements  in  the  manufacture  of 
gas,  hitherto  unknown,  or  as  producing  a  valuable  manure,  the  results  are  alike  of  the 
utmost  importance. 

(When  Mr.  Croll's  process  is  employed  before  the  lime  purifiers,  dry  lime  can  be 
used  without  creating  the  nuisance  hitherto  complained  of,  and  a  much  less  quantity  ia 
required  for  this  purification.) 

Mr.  Croll  has  recently  patented  another  invention,  connected  also  with  the  manufac- 
ture of  gas,  which  consists  in  the  combination  of  clay  and  iron  retorts,  so  that  the  heat 
of  the  furnace  first  acts  on  the  clay  retorts  and  then  passes  to  those  of  iron. 

The  annexed  drawing  is  a  transverse  section  • — 

A  is  the  fireplace. 

B  B  are  piers  of  fire-bricks,  placed  at  intervals  to  form  nostrils  or  flues,  and  the  fire 
tile  resting  upon  them  in  conjunction  with  the  front  and  back  wall,  form  the  bed  or 
support  of  the  clay  retort  1,  and  the  clay  retort  2  is  also  supported  by  the  front  and 
back  brickwork,  and  a  lump,  or  fire-brick,  e,  placed  midway  on  the  crown  of  the 
retort  1. 

F  is  a  wall  which  separates  the  clay  retorts  1  and  2,  and  the  iron  retorts  l°and  2®;  a 
space  being  left  between  the  top  of  the  said  wall  f,  and  the  under  surface  of  the  arch, 
to  allow  the  fire  or  heated  air  to  pass  freely  from  the  clay  to  the  iron  retorts. 

G  G  is  the  bed,  and  h  h  is  the  flue  under  the  iron  retort  1°.  The  retort  2®  is  sup- 
ported by  the  front  wall  and  pieces  or  lumps. 

J,  placed  at  the  back  and  crown  of  the  retort  1®,  in  connexion  with  the  horizontal 
flue.     H  is  a  vertical  flue,  forming  a  passage  thence  into  the  shafl  or  chimney. 

The  heat  passes  from  the  furnace  or  fireplace  a,  through  the  spaces  or  nostrils  formed 
by  the  piers  b  b,  and  around  the  clay  retorts  1  and  2,  over  the  wall  f,  descends  between 
and  around  the  iron  retorts  and  along  the  flue  h,  and  escapes  by  the  vertical  flue  into 
the  chimney.     The  advantages  of  this  mode  of  setting  retorts  are  the  small  quantitv  of 


I    / 


1  I 

11 


882 


GAS-LIGHT. 


brickwork  necessary  for  the  erections,  the  increased  durability  of  the  retorts,  and  iic 
economy  in  fuel.  From  adopting  th?s  mode  of  setting  a  brick  lump^  it  has  beea  fa.ind 
that  12  tons  of  coke  will  carbonize  100  tons  of  coal. 


gas-light. 


883 


l<! 


il 


L  is  the  chimney  stalk,  and  d  is  a  damper  or  register  plate  for  regulating  the  chimney 
draught. 

Before  dismissing  Mr.  Croll*s  patent  improvements,  it  is  proper  to  state,  that  the  sul- 
phuric acid  used  for  condensing  the  ammonia  should  be  free  from  iron,  otherwise  the 
8'tlphuretted  hydrogen  of  the  coal  gas  is  apt  to  give  rise  to  sulphuret  of  that  metal  whick 
will  blacken  the  sulphate  of  ammonia  and  reduce  its  value  in  the  market.  An  occur- 
rence of  this  kind  was  recently  brought  professionally  before  me  for  investigation.  The 
^phurie  acid  had  been  made  from  pyrites. 

Mr.  Kirkham,  engineer,  obtained  a  patent,  in  June,  1837,  for  an  miproved  mo<le  of 
removing  the  carbonaceous  incrustation  from  the  internal  surfaces  of  gas  retorts.  He 
employs  a  jet  or  jets  of  heated  atmospheric  air  or  other  gases  containing  oxygen,  which 
he  impels  with  force  into  the  interior  of  such  retorts  as  have  become  incrusted  in  con- 
sequence of  the  decomposition  of  the  coal.  The  retort  is  to  be  kept  thoroughly  red 
hot  during  the  application  of  the  proposed  jets.    An  iron  pipe,  constructed  with  several 


flexible  joints,  leading  from  a  blowing  machine,  is  bent  in  such  a  way  as  to  allow  its 
nozzle  end  to  be  introduced  within  the  retort,  and  directed  to  any  point  of  its  surface. 

I  sliould  suppose  that  air,  even  at  common  temperatures,  applied  to  a  retort  ignited  to 
the  pitch  of  making  gas,  would  bum  away  the  incrustations  ;  but  hot  air  will,  no  doub^ 
be  more  powerful. 

Bude-light.  —  This  brilliant  mode  of  illumination  has  been  so  called  from  the 
name  of  the  residence  in  Cornwall  of  Mr,  Goldsworthy  Gurney,  who  obtained  a 
patent  for  it  in  the  year  1838.  In  its  first  form  it  consisted  of  a  common  Argand  oil 
name  or  lamp  of  rather  narrow  circular  bore,  into  the  centre  of  whose  wick  a  jet  of 
oxygen  gas  was  admitted  through  a  tube  inserted  in  the  middle  of  the  burner.  This 
contrivance  was  not,  however,  new  in  this  country,  for  a  similar  lamp,  similarly  aup- 

f)lied  with  oxygen  gas,  was  employed  by  the  celebrated  Dr.  Thomas  Young  in  hi» 
ectures  at  the  Royal  Institution  of  Great  Britain  for  the  purpose  of  illuminating  a 
solar  microscope,  or  gas  microscope,  about  40  years  ago,  and  1  had  done  the  same  thing 
in  Glasgow  in  the  year  1806  or  1807.  When  used  as  a  light  for  lighthouses  or  foi 
other  continuous  illumination,  it  has  been  found  to  be  too  expensive  and  difficult  to 
manage.  It  was  tried  upon  a  good  scale  a  few  years  ago  both  by  the  Trinity  Honao 
in  Tower  Hill,  and  in  one  of  their  lighthouses  on  the  coast,  as  well  aa  by  the  House 
of  Commons.  The  Masters  of  the  Trinity  did  not  find  it  to  be  essentially  superior  for 
the  use  of  their  lighthouses  to  their  old  and  ordinary  plan  of  illumination  with  » 
number  of  Argand  lamps  placed  in  the  focus,  or  near  the  focus,  of  reflecting  mirrora 
It  was,  after  several  expensive  trials  by  them,  and  in  the  House  of  Commons,  abaH' 
doned  by  both. 

In  the  course  of  numerous  experiments  in  the  Trinity  House,  Tower  Hill,  Mi. 
Gurney  had  occasion  to  examine  the  structure  and  see  the  performance  of  Mr.  Fresnel'* 
compound  Argand  lamps  which  are  used  in  the  French  lighthouses,  furnished  with 
refracting  lenses  of  peculiar  forms  which  surround  these  lamps,  and  transmit  their  con- 
centrated light  in  any  desired  horizontal  direction  along  the  surface  of  the  sea.  Two  of 
Mr.  Fresnel's  lamps  are  placed  in  the  lamp  apartment  of  the  Trinity  House.  Each 
consists  of  a  series  of  4,  5,  or  6  concentric  wicks  in  the  same  plane,  supplied  with  oil 
from  the  fountain  below  by  means  of  a  pumping  mechanism,  as  in  the  well-known 
Parisian  lamps  of  Carcel  and  Gagneau.  The  effect  of  4,  5,  or  6  concentric  flames  thm 
placed  in  close  proximity  to  each  other,  with  suitable  supply  of  air  through  the  interior 
of  the  innermost  tube  and  the  interstices  between  the  exterior  ones,  is,  to  increase  th« 
heat  in  a  very  remarkable  degree,  and  by  this  augmentation  of  the  heat  to  increase  pro- 
portionably  the  light.  For  it  has  been  long  known  that  a  piece  of  even  incombustibk 
matter,  such  as  a  lump  of  brick,  intensely  heated,  sends  forth  a  most  brilliant  irradia- 
tion of  light.  This  fact  was  applied  first  to  the  purpose  of  illuminating  objects  by  Pro- 
fessor Hare,  of  Philadelphia,  fully  40  years  ago.  By  directing  the  very  feebly  lumio- 
ous  flame  cf  the  compound  jet  of  hydrogen  and  oxygen  upon  a  bit  of  clay,  such  as  one 
•of  Wedgwood's  pyrometer  pieces,  a  most  vivid  illumination  was  sent  forth  from  it  a» 
•eoon  as  it  became  intensely  heated.  More  lately,  a  piece  of  lime  has  been  used  instead 
of  a  bit  of  clay,  as  it  is  not  so  apt  to  change  by  the  ignition,  and  affords,  therefore,  a 
more  durable  effect.  It  is  used  in  our  modern  gas  microscopes.  Mr.  Gurney  suggested 
the  use  of  lime  for  the  above  purpose  in  a  work  on  chemistry  which  he  published 
more  than  twenty  years  ago.  It  was  afterwards  adopted  by  Mr.  Drummond,  in  order 
to  make  signal  lights  in  the  trigonometrical  survey  of  the  Board  of  Ordinance,  and  wa» 
therefore  called  the  Drummond  light,  though  he  had  no  share  whatever  in  the  merit  of 
the  invention. 

The  structure  of  the  Fresnel  lamp  would  naturally  suggest  to  Mr.  Gurney  the  idea 
of  trying  the  effect  of  a  similar  construction  of  an  Argand  gas  lamp.  But  prior  to  the 
execution  of  this  scheme,  he  obtained  a  second  patent  in  the  year  1839,  for  increasing 
the  illuminating  power  of  coal  gas  by  feeding  its  flame  in  a  common  Argand  burner 
with  a  stream  of  oxygen.  But  here  a  serious  difiiculty  occurred.  The  stream  of  oxygen, 
when  admitted  into  the  centre  of  such  a  flame,  instead  of  augmenting  its  quantity  of 
light,  destroys  it  almost  entirely.  This  result  might  have  been  predicted  bv  a  person 
well  versant  in  the  principles  of  gas  illumination,  as  long  ago  expounded  in  Sir  Hunv 
phry  Davy's  admirable  Researches  on  Flame.  This  philosopher  demonstrated  that 
the  white  light,  of  gas-lamps,  as  also  of  oil  lamps,  was  due  to  the  vivid  ignition  of  solid 
particles  of  carbon  evolved  by  the  igneous  decomposition  of  the  hydro-carbaret,  either 
m  the  state  of  gas  or  vapour ;  and  that  if,  by  any  means,  these  particles  were  not  de- 
posited, but  burned  more  or  less  completely  in  the  moment  or  act  of  their  evolution 
from  the  hydro-carburet,  then  the  illumination  would  be  more  or  less  impaired.  Mr. 
Gurney,  on  observing  this  result,  sought  to  obviate  the  evil,  by  charging  the  coal  ga» 
with  the  vapour  of  naphtha.  Thus  a  larger  supply  of  hydro-carburet,  and  of  carbon  of 
course,  being  obtained,  the  flame  of  the  naphthalized  gas,  admitted  with  advantage 
the  application  of  oxygen  gas,  for  the  increase  of  its  light ;  on  the  principle  of  greater 


884 


GA.S-LIGHT. 


intensity  of  ignition,  and  consequently  of  light,  being  produced  by  the  burning  of  carbon 
in  oxygen  than  in  common  air,  as  had  been  long  known  to  the  chemical  world.  But 
an  obstruction  to  the  permanent  employment  of  naphtlialized  gas  was  experienced  by 
Mr.  Gurney,  from  the  deposition  of  liquid  naphtha  in  the  pipes  of  distribution.  He 
■was  therefore  induced  to  renounce  this  project.  He  then  resorted  to  the  use  of  coalgaa, 
purified  in  a  peculiar  way,  and  burned  in  compound  Argand  lamps,  consisting  of  two 
or  more  concentric  metallic  rings,  perforated  with  rows  of  holes  in  their  upper  surfaces, 
having  intervals  between  the  rings  for  the  admission  of  a  proper  quantity  of  air,  the 
burner  being  enclosed  in  a  glass  chimney  at  the  level  of  the  name,  surmounted  by  a 
tall  iron  chimney.  Between  these  two  chimneys,  a  certain  space  is  left  for  the  admis- 
•ion  of  air,  and  to  favour  draught  and  ventilation.  The  intensity  and  whiteness  of  the 
cylinder  of  light  produced  by  the  combustion  of  coal-gas  in  this  lamp  are  truly  ad- 
mirable, and  form  such  an  improvement  in  illumination  for  streets,  churches,  public 
rooms  and  private  houses,  as  to  merit  the  protection  of  a  patent,  and  the  encourage- 
Bieat  of  the  public  at  large. 

General  Estimate  of  Sizes,  Number  of  Concentrics,  Consumption  of  Gas,  and 

Comparative  Light 


Size. 

Number  of 
Concentrics. 

Bnde  Consump- 
tion per  hour. 

Height  of 

Flame. 

Comparative  Light 

Argand 

Consumption 

per  hour. 

Inches. 

Feet.     Inches. 

Inches. 

15-hole  Argands. 

Cubic  Feet. 

2i 

2 

10           6 

3 

5 

30 

3 

2 

16           4 

8 

8 

48 

H 

2 

21           6 

3 

10 

60 

4 

2 

26          4 

3 

IS 

72 

4i 

2 

33          7 

3 

IS 

90 

5 

S 

40          0 

H 

18 

108 

5i 

3 

43          5 

H 

20 

120 

6 

8 

66          4 

4 

24 

144 

Laming  and  Evans's  Invention. — The  first  part  of  this  invention  consists  of  an  im- 
provement in  retorts  for  making  gas,  and  for  other  uses ;  and  in  making  pots,  crucibles, 
muffles,  stoves,  fire-bricks  and  lumps,  and  other  articles  of  clay,  required  to  stand  the 
action  of  fire  without  cracking.  The  improvement  consists  in  mixing  with  the  fireclay, 
which  is  to  enter  into  the  composition  of  any  of  the  aforesaid  articles,  about  025  per 
cent  of  its  weight  of  asbestos  or  fibrous  silicate  of  magnesia ;  the  vessels  are  then  to 
be  constructed  and  burned  in  the  usual  manner.  The  patentees  state  that  they  do 
not  confine  themselves  to  any  particular  forms  of  the  articles,  each  of  which  may  be 
made  of  one  or  more  pieces,  as  at  present ;  and  the  proportion  of  silicate  of  mag- 
nesia may  be  varied  to  meet  the  exigencies  of  particular  cases,  its  introduction  being 
for  the  purpose  of  giving  greater  tenacity  to  the  materials  used,  and  thus  diminishing 
their  tendency  to  become  cracked  under  the  influence  of  change  of  temperature. 

Tliey  claim  under  this  head  of  the  invention,  the  introduction  of  asbestos  or  fibrous 
silicate  of  magnesia  among  the  materials  used  for  making  articles  of  clay,  intended  to 
be  submitted  to  a  great  heat ;  and  the  use  of  all  such  articles,  made  with  asbestos  or 
fibrous  silicate  of  magnesia  in  their  composition. 

Another  part  of  this  invention  consists  in  an  arrangement  of  apparatus  for  making 
gas  from  oil,  tar,  melted  pitch,  resin,  fat,  or  other  analogous  material,  in  conjunction 
or  not  with  water.  The  apparatus  consists  of  an  iron  or  clay  retort,  compoped  of  two 
horizojital  chambers,  one  above  the  other,  and  communicating  at  the  back  only.  The 
ends  of  the  chambers  are  closed  by  three  man-hole  doors ;  two  of  which  are  secured 
over  the  front  end  of  the  chambers ;  and  the  third,  which  is  a  large  door,  serves  to 
close  the  hind  ends  of  both  chambers  ; — the  three  doors  all  projecting  beyond  the  brick- 
work petting  of  the  retort  Upon  the  upper  chamber,  near  the  front  end  thereof,  is  an 
inverted  funnel  of  large  diameter,  closed  by  a  cover,  the  edge  of  which  is  turned  down, 
and  dips  into  a  hydraulic  joint,  or  into  a  joint  filled  with  metal,  fusible  at  the  tempe- 
rature to  which  it  is  exposed,  or  else  it  is  secured  in  the  same  manner  as  the  ordinary 
man  hole  doors.  The  cover  is  fitted  with  a  double  syphon,  furnished  with  a  stop-cock. 
The  eduction-pipe,  leading  to  the  hydraulic  main,  is  connected  with  the  front  end  of 
the  lower  chamber  of  the  retort.  To  use  this  apparatus,  previously  raised  to  the  usual 
temperature,  the  patentees  charge  the  upper  chamber  with  coke,  heaping  it  some- 
"what  just  beneath  the  funnel,  and  allowing  some  pieces  to  fall  over  against  the 
large  man-hole  dt)or  at  the  back,  and  they  charge  the  lower  chamber  either  with  coal 
or  coke.    A  stream  of  oil,  tar,  melted  pitch,  resin,  fat,  or  other  analogous  matter,  in 


GAS-LIGHT. 


885 


conjunction  or  not  with  water,  is  then  allowed  to  fall  from  the  double  syphon  throueh 
the  large  funnel,  on  to  the  red-hot  coke  beneath ;  it  passes  thence,  partly  as  gas  and 
partly  as  liquid,  through  the  upper  chamber  to  the  back  of  the  lower  one,  aW  which 
It  next  nr(K5eeds,  chiefly  in  the  state  of  gas,  and  escapes,  mixed  with  the  gaseous  products 
Of  the  lower  chamber,  through  the  eduction  pipe  into  the  hydraulic  main.  When  the 
ower  chamber  of  this  apparatus  is  charged  with  coal,  the  liquid  should  not  be  permitted 
to  flow  from  the  double  syphon,  till  the  coal  has  had  time  to  give  off"  the  greater  part  of  its 
richer  gas  and  to  become  heated  throughout;  but  when  coke  is  used  in  both  chambere, 
the  liquid  13  admitted  from  the  commencement,  and  without  intermission,  until  the 
passages  of  the  gas  apparatus  need  to  be  opened  and  cleaned  out 

The  patentees  do  not  claim  the  making  of  gas  from  tar,  or  any  other  form  of 
hydro-carbon,  or  water,  by  means  of  red-hot  coke,  or  the  combining  of  any  materials 
affording  gas.  What  they  claim  is.  the  combination  and  arrangement  of  the  apparatus 
particularly  of  the  large  funnel,  with  the  double  chambers,  and  back  and  front  man-hole 
doors,  for  making  ^as  by  the  decomposition  of  any  suitable  hydro-carbon,  or  water,  by 
bringing  it,  in  a  fluid  state,  into  contact  with  red-hot  coke  or  other  suitable  material 

Another  part  of  the  invention  consists  in  elongating  the  eduction  pipes  of  retorts, 
nsed  for  making  gas  for  illumination,  into  their  interior,  and  arranging  them  in  lin^ 
near  their  axes.  The  further  ends  of  these  pipes  are  left  open,  and  they  are  supported 
by  bearers.  Hole,  should  be  made  along  the  pipes,  but  only  in  sufficient  number  to 
permit  of  the  free  escape  of  the  gas  as  it  is  generated;  or  a  longitudinal  slit  may  be 
made  in  the  under  side  of  the  horizontal  pipe,  from  its  further  end  to  near  its  ascendine 
portion;  and  this  arrangement  is  preferred,  because  it  admits  of  the  passage  beini 
cleared  out  by  a  proper  tool,  in  the  event  of  its  becoming  choked.  The  impfovemer^ 
IS  applicable  to  retorts  of  any  material,  and  of  the  ordinary  forms ;  but  it  wiU  be  found 
more  easy  to  charge  the  retorts,  to  which  this  improvement  is  applied,  when  they  are 
made  large  enough  to  receive  a  charging-scoop  on  either  side  of  the  horizontal  eduction 
pipes  Ihe  object  of  the  improvement  is  to  diminish  the  contact  of  a  gas  with  a  surface 
heated  high  enough  to  cause  it  to  deposit  some  portion  of  its  carbon;  and  thus  to 
produce  a  richer  gas,  or  a  larger  quantity  of  equally  rich  gas,  from  a  given  quantity 

The  claim  made  under  this  head  is  for  the  elongation  of  the  eduction-pipes  of  retorts, 
used  for  making  gas  for  illumination,  along  or  near  their  axes. 

Another  part  of  the  invention  consists  in  a  process  for  obtaining  light  by  means  of 
platinum,  heated  to  whiteness  by  coal  gas  or  peat  gas.  It  is  known,  Uiat  when  water 
IS  decomposed,  and  he  resulting  hydrogen  burnt  within  a  small  cage,  made  of  platinum 
wire  or  platinum  foil,  in  such  a  manner  as  to  heat  the  metal  to  whiteness,  the  platinum 
becomes  luminous,  and  remains  so  as  long  as  its  temperature  is  maintained ;  but  it  is 
equally  well  known  that  hydrogen  gas,  resulting  from  the  decomposition  of  water,  U 
not  readily  obtainable  under  the  generality  of  circumstances  when  light  is  required 
Ihe  improvement  consists  in  replacing  hydrogen  gas  from  water  by  coal  gas  (which  is 
to  be  obtained  almost  universally,  and  which  answers  the  purpose)  or  by  peat  gas.  In 
carrying  out  this  improvement  it  is  preferred  to  burn  the  gas  either  by  itself  or  mixed 
with  atmospheric  air,  within  a  platinum  wire  cylinder,  greater  in  height  and  diameter 
and  made  of  coarser  material,  as  the  quantity  of  gas  burned  within  it  in  a  given  time 
18  greater,— the  only  practical  rule  that  it  is  necessary  to  give  being,  that  all  the  metal 
be  placed,  with  respect  to  the  flame,  in  the  best  position  for  becoming  white-hot  The 
advantages  which  result  from  this  part  of  the  invention  are,  first  with  resect  to 
ordinary  coal  gas,  that  more  light  is  obtained  in  proportion  to  the  quantity  of  coal  gas 
consumed,  thaii  is  the  case  when  platinum  is  not  used;  and,  second Iv,  that  by  its 
means,  a  good  light  is  obtained  by  the  combustion  of  peat  gas,  or  of  coafgaa  of  inferior 

Under  this  head,  the  patentees  state,  that  they  neither  claim  nor  restrict  themselves 
to  the  use  of  any  particular  form  or  dimensions  of  the  platinum  apparatus;  but  what 
they  claim  is,  the  use  of  coal  or  peat  gas,  mixed  or  not  with  air,  for  heating  platinum 
wire  or  foil  to  whiteness,  and  thereby  producing  light 

A  previous  patent  has  been  obtained  by  one  of  the  patentees  (Mr.  Lamin^),  for 
purifying  coal  gas  by  a  solution  of  muriate  of  iron,  mixed  with  porous  materials ;  and  also 
by  muriate  of  iron,  decomposed  by  lime  into  chloride  of  calcium  and  oxide  of  iron,  and 
made  porous  by  suitable  materials.  Now,  one  part  of  the  present  invention  consists  in 
combining  known  processes,  so  as  to  obtain  the  last-named  purifying  materials.  The 
patentees  decompose  sulphate  of  iron,  in  solution,  by  its  equivalent  quantity  of  chloride 
of  sodium ;  and,  having  separated,  by  known  means,  the  resulting  sulphate  of  soda, 
they  add  to  the  solution  of  muriate  of  iron  concentrated  by  evaporation,  first,  enough 
dry  sawdust,  or  other  suitable  matter,  to  absorb  it  and  then  enough  hydrate  of  lime 
to  decompose  it  into  chloride  of  calcium  and  precipitated  oxide  of  iron.  Coal  gas  is 
purified  with  this  mixture,  disposed  in  dry  purifiers ;  and,  afterwards,  sulphur,  cyanogen. 


I 


686 


GAS-LIGHT. 


GAS-LIGHT. 


887 


! 


and  munate  of  ammonia,  are  extracted  from  the  used  material  by  any  ordinary  pro- 
cesses adapted  for  that  purpose.  Sometimes  the  purifying  material  is  modified  in  the 
following  manner  :  an  equivalent  quantity  of  ground  or  granulated  sulphate  of  iron  or 
chloride  of  sodium,  is  mixed  with  the  other  of  these  salts  in  solution,  absorbed  into 
aawdust  or  other  smtable  matter ;  and  then  an  equivalent  of  hydrate  of  lime  is  stirred 
in.  This  modified  material,  after  being  used  in  dry  purifiers  for  purifying  coal  ^as 
affords  by  lixiviation  a  mixed  solution  of  sulphate  of  soda  and  muriate  of  ammonia  • 
sulphur  and  cyanogen  also  may  be  extracted  from  it.  as  m  the  former  case.  Sometimes 
the  sulphate  of  iron  is  replaced  by  sulphate  of  copper  ;  and  then  the  resultino-  oxide  of 
course,  is  the  oxide  of  that  metal  instead  of  the  oxide  of  iron.  °  ' 

The  patentees  claim,  under  this  head,  the  combination  of  processes  above  described 
for  making  a  purifying  material,  containing  chloride  of  calcium,  and  precipitated  oxide 
of  iron  or  copper  ;  and  likewise  the  composition  of  the  modified  material,  as  described. 
They  also  claim  the  use  of  both  kinds  of  materials  for  purifying  coal  gas 

Another  part  of  the  invention  consists  in  purifying  coal  gas  by  means  of  a  cheap 
material,  made  by  mixiiig  refuse  sulphate  of  lime  or  gypsum,  in  a  finely  divided  state, 
with  sulphate  of  iron.  The  sulphate  of  iron  should  be  either  ground  fine  or  granulated 
and  mixed  with  sawdust,  or  other  matter,  suitable  for  separating  its  particles  •  or  it  mar 
be  merely  mixed,  m  a  divided  state,  with  the  earthy  salt,  or  absorbed  into  its  mass  or 
mto  sawdust,  or  other  porous  matter.  The  gypsum  should  be  previously  baked  at  a 
red  heat,  to  prevent  its  tendency  to  solidify  with  water.  The  material,  thus  prepared. 
w  used  m  dry  purifiers,  m  the  way  well  understood  for  purifying  by  hydrate  of  lim^ 
For  the  sulphate  of  iron  other  metallic  salts  may  be  substituted  with  similar  resulU- 
such,  for  example,  as  muriate  of  iron,  sulphate  or  muriate  of  zinc,  sulphate  or  muriate 
of  manganese,  or  even  sulphate  or  muriate  of  copper;  but  sulphate  of  iron  is  preferred 
The  resulting  mass  is  either  used  as  a  manure,  or  else  it  is  subjected  to  certain  known 
chemical  processes  for  obtaining  from  it  an  ammoniacal  salt,  or  salts,  sulphur  and 
cyanc^en.  *^       * 

The  claim  under  this  head  is  for  the  purification  of  coal  gas  by  the  use  of  sulphate  of 
hme  mixed  with  any  of  the  metallic  salts  above  named;  and  the  use  of  the  spent 
purifying  material  as  a  manure.  '^ 

Another  improvement  consists  in  causing  impure  coal  gas  to  pass  through  dry  puri- 
fiers charged  with  a  porous  solid  material,  which  is  made  by  mixing,  in  about  equiva- 
Jent  proportions,  hydrated  or  precipitated  oxide  of  iron,  with  carbonate  of  lime  mae- 
aesia,  carbonate  of  magnesia,  or  magnesian  limestone,  in  fine  powder,  or  else  burned  or 
slaked,  either  by  themselves,  or  rendered  more  pervious  to  the  gas  by  sawdust  or 
other  suitable  matter.  A  mixture  of  precipitated  oxide  of  iron  and  lime  answers' the 
same  purpose,  and  was  claimed  by  Mr.  Laming,  under  a  former  patent.  In  each  of  the 
above  cases  oxide  of  copper  may  be  substituted  for  the  oxide  of  iron.  All  the  several 
compounds,  when  they  begin  to  act  on  the  impure  gas,  purify  it  from  sulphuretted 
hydrogen  and  cyanogen;  and  any  one  of  them,  having  been  once  made  foul,  and 
afterwards  placed  m  contact  with  atmospheric  air  for  a  few  hours,  acquires  the  property 
of  purifying  coal  gas  from  ammonia  also.  The  spent  materials  afford,  by  process^ 
well  known,  cyanogen,  sulphur,  and  ammoniacal  products. 

The  patentees  claim,  under  this  head,  the  purification  of  coal  gas,  by  mixtures  made 
as  described,  whether  with  hydrated  or  precipitated  oxide  of  copper  or  of  iron 

Another  part  of  the  invention  consists  in  a  particular  way  of  using  chloride  of  mac- 
nesium  or  sulphate  of  magnesia,  for  withdrawing  from  coal  gas  ammonia  and  carbomc 
acid,  bawdust  or  other  solid  matter  calculated  to  expose  an  extensive  surface  to  the 
gas,  without  opposing  great  resistance  to  its  passage,  is  caused  to  absorb  a  saturated 
solution  of  one  or  both  of  the  above  named  salts  ;  or  those  salts  may  be  mixed  sin^rly 
or  together,  m  a  divided  and  solid  state,  with  sawdust  or  other  suitable  matter  in  a 
damp  state  ;  and  then  the  mixture  is  placed  in  dry  purifiers,  through  which  the  eas  ia 
made  to  pass  in  its  way  from  the  condensers  to  the  gas-holders.  When  the  gas  ceases 
to  be  purified  from  its  ammonia,  the  contents  of  the  purifier  are  taken  out  and  wa-^hed. 
to  obtain  an  ammoniacal  solution  ;  and  a  new  charge  of  similar  purifying  materials  is 
mtroduced  into  the  purifier.  r      j    &  c»w  » 

The  claim  made  under  this  head  is  for  the  extraction  of  ammonia  and  carbonic  acid 
from  coal  gas,  by  chloride  of  magnesium,  or  sulphate  of  magnesia  and  water,  diffused 
through  sawdust  or  other  sohd  matter,  capable  of  exposing  an  extensive  surface  of  the 
re-agents  to  the  gas,  without  materially  impeding  its  passage. 

A  further  improvement  consists  in  purifying  coal  gas  by  the  use  of  a  solid  material, 
oontainmg  chloride  of  magnesium  or  of  calcium,  or  sulphate  of  magnesia,  mixed  with 
hydrated  or  precipitated  oxide  of  copper.  To  make  this  purifying  material,  the 
patentees  take  sawdust,  or  other  suitable  matter,  wetted  with  a  strong  solution  of 
suitable  matter,  wetted  with  a  strong  solution  (.f  muriate  or  sulphate  of  copper,  or  else 
either  of  those  salts  of  copper  in  a  finely-divided  state,  and  mixed  with  moistened 


sawdust  or  other  suitable  matter,  and  they  mix  therewith  enough  lime,  magnesia,  or  its 
carbonate,  or  magnesian  limestone,  burned  and  slaked  with  water  or  powdered,  to 
decompose  the  salt  of  copper  into  precipitated  oxide  of  the  metal,  and  a  salt  of  lime  or 
magfjesia,  or  both.  Or,  instead  of  making  extemporaneously  both  or  either  of  the  salts 
of  magnesia  and  lime  and  oxide  of  copper,  thev  mix  sulphate  of  magnesia  or  chloride  of 
magnesium  or  of  calcium,  ready  formed  anci  in  a  state  of  mechanical  division,  or  in 
solution,  with  oxide  of  copper  and  sawdust,  or  other  suitable  matter.  These  purifying 
materials  are  used  in  dry  purifiers,  like  hydrate  of  lime.  They  can  be  employed  for 
removing  ammonia,  carbonic  acid,  and  sulphuretted  hydrogen  from  the  gas;  or  they 
may  be  used  for  the  latter  impurity  without  the  two  former.  In  the  first  case,  it  is  found 
useful  to  add  to  them  about  half  an  equivalent  of  fine  carbonate  of  lime,  or  of  carbonate 
of  magnesia,  or  of  both;  and  in  the  latter  case  it  is  preferred  to  make  either  the 
same  addition,  or,  in  lieu  thereof,  to  add  about  the  same  quantity  of  caustic  lime  or 
magnesia,  or  of  both  of  them.  When  the  used  material  will  no  longer  purify  the  gas 
from  sulphuretted  hydrogen,  either  it  is  taken  out  of  the  purifier  and  exposed  to  the 
atmosphere,  or  else  a  current  is  directed  through  it  while  in  that  vessel ;  a  vent-hole  in 
the  purifier,  below  the  level  of  the  foul  purifying  matter  being  open,  or  not,  at  the  same 
time  as  may  be  found  necessary.  The  purifying  energy  of  the  material  is  thus  restored, 
ana  this  alternate  expenditure  and  restoration  of  energy  can  be  repeated  a  number  of 
times,  until  the  material  becomes  sufficiently  charged  with  sulphur  and  with  ammoniacal 
and  cyanogen  products,  or  either  of  them,  to  render  it  worUi  while  to  extract  it  or  them 
m  any  known  way. 

The  patentees  claim  under  this  head,  the  purifying  coal  gas  by  the  repeated  use  of  a 
solid  material,  containing  sulphate  of  magnesia,  or  chloride  of  magnesium,  or  calcium,  or 
more  than  one  of  those  re-agents,  in  combination  with  oxide  of  copper,  and  mixed  or  not 
wiUi  lime  or  magnesia,  or  both,  or  either,  or  both  of  the  carbonates  of  those  earths. 

ihe  next  part  of  the  invention  consists  in  a  process  for  converting  the  ammoniacal 
liquor,  produced  in  making  gas,  or  by  distilling  animal  matters,  into  sulphate  of 
ammonm.  By  repeatedly  using  the  same  portion  of  hydrated  or  precipitated  oxide  of 
iron  or  copper,  m  conjunction  with  lime,  magnesia,  carbonate  of  lime,  carbonate  of  magnesia, 
or  any  compound  of  lime  or  magnesia,  susceptible,  under  the  circumstances  in  which  it  is 
used  ot  being  decomposed  by  carbonate  of  ammonia,— for  purifying  coal  gas,  with  subse- 
quent exposure  to  atmospheric  air,  the  spent  material  eventually  becomes  in  ereat  part 
dianged  into  sulphate  of  lime  or  sulphate  of  magnesia,  mixed  with  oxide  of  a  metal 
When  tins  has  taken  place,  the  spent  material  is  mixed  in  a  vat  for  an  hour  or  two,  with 
nearly  as  niuch  of  the  ammoniacal  liquor  as  it  will  decompose  ;  the  fluid  is  next  drawn  off 
and  hltered ;  the  saturation  of  any  ammonia  which  it  may  contain  in  a  volatile  state  is 
effected  by  sulphuric  acid;  and  then  it  is  evaporated  to  obtain  crystals  of  ammoniacal 
sulphate.  The  same  process  is  followed  by  another  good  result;  for  the  decomposition 
of  the  carbonate  of  ammonia  by  the  sulphate  of  lime,  or  sulphate  of  magnesia,  reproduces 
m  the  spent  material  a  carbonate  of  the  earth,  which  fits  it  for  beginniSg  anew  the  work 
of  purity mg  coal  gas.  ©         o 

The  patentees  claim  the  use  of  the  spent  materials,  above  described,  for  convertins 
so  u  ions  of  carbonate  of  ammonia,  mixed  or  not  with  hydrosulphate  of  ammonia,  int! 
solutions  of  ammoniacal  sulphate ;  by  which  use,  also,  the  sulphate  of  lime  or  sulphate 
of  magnesia,  m  the  said  mixtures,  is  changed  into  carbonate  of  lime,  or  carbonate  of 
magnesia. 

When  solid  or  porous  mixtures,  containing  hydrated  or  pretipitated  oxide  of  iron  or 
copper,  or  a  salt  of  either  of  those  metals,  decomposable  into  hydro  sulphuret  of  the 
metal  are  employed  to  absorb  sulphuretted  hydrogen  from  coal  gas,  and  aVe  afterwards 
brought  into  contact  with  atmospheric  air,  the  mixture  rapidly  absorbs  oxygen    and 
thereby  acquu-es  an  elevated  temperature,  greater  in  proportion  as  it  is  free 'from 
moisture     In  certain  cases,  when  the  materials  are  at  first,  or  become  by  use,  dry  to  the 
touch,   their   temperature  during   the  subsequent   absorption   of    oxygen   rises   muck 
higher  than  is  desirable.     One  way  of  preventing  this  injurious  accession  of  heat  is  by 
communicating  humidity  to  the  mixture  of  materials,  at  a  proper  time  ;  and  this  consti- 
tutes another  part  of  the  invention.     This  improvement  is  put  into  practice,  either  by 
sprmkling  the  used  purifying  materials  with  water,  on  removing  the  cover  from  the 
vessel,  which  contains  them ;  or  by  pipes,  properly  disposed  within  the  vessel,  distribut- 
ing water  over  the  surface  of  the  materials,  without  the  cover  being  removed;  or  by 
sprinkling  the  materials  with  water,  after  they  have  been  thrown  ouf  of  the  vessel  •  or 
lastly,  by  placing  the  purifier  in  communication  with  a  steam-boiler,  and   directing 
through  the  used  materials  a  sufficient  quantity  of  the  vapour  of  water  to  moisten  them 
and  subsequently  submitting  them  to  the  influence  of  a  current  of  atmospheric  air.  also 
directed  through  them.     Tiie  patentees  state,  that  thev  know  it  to  be  necessary  that  the 
metallic  oxides  used  for  purifying  coal  gas  from   sulphuretted    hydrogen   should  be 
hydrated  ;  that  is  to  say,  combined  with  a  certain  portion  of  water  in  a  dry  state  •  but 


■■PP 


888 


GAS-LIGHT. 


II 


experience  has  proved  to  them,  contrary  to  common  opinion,  that  the  said  oxides  act  less 
energetically  on  the  sulphuretted  hydrc^en  in  the  gas,  and  also  that  they  regain  their 
expended  energy  less  suddenly,  when  they  contain  water  in  a  liquid  state,  than  wheo 
they  are  free  from  hygroraetric  water. 

The  patentees  do  not  claim  the  regeneration  of  the  purifying  energy  of  any  spent 
purifying  mixtures,  by  exposing  them  to  atmospheric  air;  but  what  they  claim  is,  tlia 
means,  above  described,  for  checking  the  rapidity  of  the  regenerating  action,  and,  conse- 
quently, preventing  the  temperature  of  the  materials  from  rising  to  a  pernicious  height ; — 
▼it,  by  wetting  them  with  water,  or  by  condensing  steam  in  their  mass,  either  in  or  out 
of  the  purifier,  at  any  time  after  they  commence  to  purify  the  gas,  and  before  they  are 
put  in  communication  with  the  atmosphere. 

The  patentees  have  found  that  mixtures  containing  hydrated  or  precipitated  oxide  of 
iron,  changed  into  hydro-sulphuret  of  iron,  by  purifying  coal  gas  from  sulphuretted 
hydrogen,  do  not  readily  re-absorb  oxygen,  and,  consequently,  do  not  readily  recover 
their  purifying  energy  at  temperatures  below  32°  Fahr. 

Now,  another  improvement  consists  in  applying  to  such  used  mixtures,  during  frosty 
weather,  atmospheric  air,  artificially  warmed  to  about  60°  Fahr. :  by  the  ordinary  opera- 
tions of  the  "  retort  house,"  or  in  any  other  convenient  manner.  The  warmed  air  may  be 
used  there,  or  conducted  thence  to  the  purifiers,  by  suitable  pipes,  in  which  a  draft  ia 
established  by  any  known  means. 

The  claim  under  this  head  is  for  the  use  of  air,  artificially  warmed,  for  promoting,  in 
cold  weather,  the  regeneration  of  hydrated  oxide  of  iron,  in  mixtures  which  have  beea 
used  for  purifying  coal  gas  from  sulphuretted  hydrogen, — whether  the  warmed  air  be 
conveyed  to  the  used  purifying  mixtures,  or  the  latter  be  carried  to  the  warm  air. 

Another  part  of  the  invention  consists  in  the  use  of  phosphate  of  lime,  dissolved  in 
hydrochloric  acid,  for  purifying  coal  gas,  and  for  decomposing  the  ammoniacal  liquors 
produced  in  making  gas,  and  in  the  distillation  of  animal  matters,  and  the  appliciitioit  of 
the  products  as  manures.  In  carrying  out  the  improvement,  bones,  or  other  form  of 
phosphate  of  lime,  are  dissolved  in  hydrochloric  acid.  This  solution  is  prepared  for  puri- 
fying gas  by  mixing  it  with  sawdust  or  other  suitable  solid  matter;  and  thus  it  is  exposed 
to  the  impure  gas  in  dry  purifiers.  To  use  the  solution  for  decomposing  ammoniacal 
liquors,  one  of  the  fluids  is  added  to  the  other,  until  the  hydro-sulphuric  and  carbonic 
acids  combined  with  the  ammonia  have  escaped.  To  facilitate  the  transport  of  the  pro- 
duct, and  its  application  as  a  manure,  it  is  heated  in  pans  until  it  becomes  dry.  The 
product  of  the  purification  of  gas  is  also  a  good  manure,  mixed  as  it  i&  with  the  sawdust 
or  other  absorbent  matter  used. 

The  patentees  claim  under  this  head  the  use  of  a  solution  of  phosphate  of  lime  in 
hydrochloric  acid,  for  purifying  coal  gas  and  for  saturating  ammoniacal  solutions ;  and 
also  the  use  of  the  products  as  manure. 

Another  part  of  the  invention  relates  to  certain  processes  for  obtaining,  in  an  economi- 
cal manner,  one  of  the  re-agents  which  the  patentees  use  for  purifying  gas, — namely 
chloride  of  calcium.  In  certain  chemical  works,  hydrochloric  acid  gas  is  a  residuary  pro- 
duct,— not  only  of  no  value,  but  even  costly  to  get  rid  of  without  nuisance  to  the  neigh- 
bourhood. One  of  the  processes  consists  in  causing  hydrochloric  acid  gas  to  pass,  in  9 
heated  state,  over  beds  of  lime,  or  carbonate  of  lime,  in  its  way  from  the  furnaces,  where 
it  is  generated,  to  the  condensers,  where  it  would  else  become  absorbed  into  water. 
The  beds  of  lime,  or  carbonate  of  lime,  are  formed  on  the  bottom  of  the  ordinary 
conduits ;  two  conduits  being  arranged  in  a  line,  and  worked  and  discharged  alternately. 
When  the  lime  in  one  passage  has  been  converted  into  chloride,  the  draft  through 
it  is  diverted  into  the  neighbouring  passage  by  means  of  dampers  arranged  for  that  pur- 
pose ;  and  the  finished  charge  is  withdrawn  through  doors  made  at  convenient  distances. 
When  this  is  done,  the  bed  is  re-charged  with  lime  or  its  carbonate,  in  readiness  to 
receive  the  current  of  hydrochloric  acid,  after  it  shall  have  saturated  the  lime  in 
the  second  conduit.  When  this  saturation  is  completed,  the  dampers  are  reversed, 
so  as  to  divert  the  acid  gas  again  into  the  first  conduit,  while  the  charge  of  the 
second  is  being  withdrawn,  preparatory  to  re-charging  it  a  second  time  ;  and  so  on  con- 
tinually. By  the  second  process,  hydrochloric  acid  is  obtained  in  a  concentrated  state, 
preparatory  to  its  saturation  in  a  fluid  form  by  lime  or  its  carbonate,  or  to  its  application 
to  other  uses.  This  process  is  carried  on  with  only  one  conduit  leading  from  the  fur- 
naces where  the  hydrochloric  acid  is  generated.  The  conduit  is  lined  with  hard  glazed 
bricks,  or  tiles,  or  sandstone ;  and  its  bottom  is  so  constructed,  that  any  fluid  formed 
^thin  it  shall  escape  by  a  pipe  adjusted  to  its  lowest  part  Along  this  conduit  a 
number  of  porous  earthenware  vessels  are  arranged  in  a  line  or  lines,  standing  on  its 
floor,  and  built  into  its  arch  or  cover  up  to  their  necks.  These  vessels  are  filled  with 
water,  and  made  to  communicate,  by  means  of  syphons,  with  one  another,  and  with  a 
reservoir  of  water  placed  with  its  highest  part  on  the  same  level  as  the  mouths  of  the 
earthenware  vessels.    By  well-known  arrangements,  the  water  is  kept  at  a  constant  level 


GAS-LIGHT. 


889 


in  the  reservoir,  and  consequently  at  a  constant  level  in  the  earthenware  vessels  which 
communicate  with  it.  The  consequences  of  this  arrangement  are,  that  the  water  con- 
tained in  the  vessels  within  the  heated  conduit  is  speedily  raised  to  a  temperature  of 
212°  F. ;  that  the  gaseous  contents  of  the  conduit  are  reduced  to  that  temperature,  or 
nearly  so, — and  that  the  water  which  exudes  from  the  porous  earthenware  absorbs  as 
nauch  hydrochloric  acid  gas  as  it  can  combine  with.  Now,  as  strong  hydrochloric  acid 
18  condensable  at  a  temperature  above  212°  Fahr, ;  and  as  the  vapour  of  water  is  not 
condensable  at  that  temperature,  the  strong  acid  flows  down  the  outsides  of  the  porous 
vessels  and  runs  in  a  stream  to  the  most  depending  part  of  the  passage,  where  it  escapee 
by  the  pipe  placed  for  that  purpose.  By  treating  the  acid  so  obtained  with  lime  or  it« 
carbonate,  chloride  of  calcium  or  muriate  of  lime  is  obtained,  with  hardly  any  cost  for 
evaporatioa 

The  patentees  claim,  under  this  head,  making  chloride  of  calcium,  by  causing  the 
hydrochloric  acid  gas,  which  results  from  the  decomposition  of  common  salt  by  sulphuric 
acid,  to  act  on  lime  or  carbonate  of  lime  in  its  passage  from  the  furnace  where  the 
decomposition  is  effected  ;  and  also  the  collecting  of  concentrated  hydrochloric  acid,  for 
making  chloride  of  calcium  or  other  purposes,  by  condensing  hydrochloric  acid  gas  in 
water  by  means  of  earthen  vessels  built  into  a  conduit  or  flue,  conducting  from  furnacea 
in  which  chloride  of  sodium  is  decomposed  by  sulphuric  acid,  and  containing  water  kept 
at  about  212°  Fahr.  by  the  heated  products  of  the  said  furnaces. 

The  next  part  of  the  invention  is  a  new  way  of  using  certain  forms  of  carbon  for 
purifying  coal  gas  and  obtaining  ammonia  therefrom.  It  consists  in  alternately  causing 
the  material  to  absorb  impurities  from  the  gas,  and  to  discharge  them  under  the  influence 
either  of  heat  or  of  a  current  of  air,  or  steam  directed  through  the  purifying  material. 
In  carrying  out  this  improvement,  a  dry  lime  purifier,  or  other  convenient  vessel,  is  filled 
with  animal  charcoal  in  coarse  powder,  and  impure  coal  gas  is  directed  through  it,  until 
it  no  longer  issues  from  the  vessel  pure.  The  gas  is  then  sent  in  another  direction,  and  a 
current  of  steam  or  air,  heated  or  otherwise,  is  passed  through  the  foul  material ;  the 
volatile  products  being  received  into  any  desirable  acid  or  other  substance  calculated  to 
fix  the  ammonia,  or  else  the  ammonia,  combined  with  carbonic  and  hydro-sulphuric  acids, 
is  condensed  by  water,  or  by  the  abstracting  of  heat,  in  any  suitable  apparatus.  If  steam 
be  used,  it  brings  away  nearly  the  whole  of  the  ammonia,  but  it  damps  the  purifying 
material,  which  then  needs  to  be  dried  by  a  current  of  hot  air  or  otherwise ;  and  if  air 
be  used,  in  the  first  instance,  to  bring  away  the  ammonia,  part  of  it  becomes  sulphate  of 
that  base,  and  must  be  removed  by  washing.  In  addition  to,  or  without  the  introduction 
of  air  or  steam  among  the  purifying  material,  it  may  be  heated  by  steam  or  hot  water 
contained  in  a  jacket  around  the  vessel,  or  in  pipes  within  it ;  or  the  foul  material  may 
be  removed  from  the  purifier  and  heated  to  about  212°  Fahr.  in  any  suitable  close  vessel 
Coke,  wood,  charcoal,  or  peat  charcoal  may  be  substituted  for  animal  charcoal,  in  the  pro- 
cess above  described,  but  with  inferior  results. 

The  patentees  do  not  claim  the  exclusive  use  of  any  form  of  carbon  for  absorbino-  the 
impurities  of  coal  gas ;  their  claim  being  for  the  means  above  described,  for  making^coke 
and  charcoal  repeatedly  useful  for  purifying  coal  gas,  and  for  obtaining  its  ammonia  by 
their  agency. 

Anotlier  part  of  the  invention  consists  of  certain  processes  by  which  prussiate  of  potasli, 
prussiate  of  soda,  and  prussiate  of  ammonia,  are  obtained  from  prussiate  of  lime.  With 
respect  to  prussiate  of  potash,  the  process  is  to  mix  well  together  equivalent  quantities  of 
prussiate  of  lime  and  sulphate  of  potash,  or  carbonate  of  potash,  previously  dissolved  in 
separate  portions  of  water ;  and  then,  after  subsidence  of  the  sulphate  or  carbonate  of 
lime  which  is  formed,  to  evaporate  and  crystallize  the  clear  solution.  The  prussiates  of 
soda  and  of  ammonia  are  made  in  like  manner,  by  substituting  the  sulphates  or  carbonates 
of  the  respective  bases  for  the  sulphate  or  carbonate  of  potash. 

The  claim  under  this  head  is  for  the  manufacture  of  the  prussiates  of  potash,  soda,  and 
ammonia,  by  decomposing  solutions  of  the  sulphates  or  carbonates  of  those  bases  by  solu- 
tions of  prussiate  of  lime. 

Another  improvement  consists  in  a  process  for  obtaining  carbonic  acid  gas  for  converting 
the  hydrosulphate  of  ammonia  in  gas  liquor  into  carbonate  of  ammonia,  and  for  other 
useful  purposes  to  which  carbonic  acid  gas  is  applicable.  It  is  known  that  hydrosulphate 
of  ammonia  is  decomposable  by  carbonic  acid,  and  that  hydrosulphate  of  ammonia  existo 

in  gas  liquor.  To  change  it  into  carbonate  of  ammonia,  the  patentees  proceed  as  follows : 

They  make  a  mixture  of  deutoxide  of  copper  and  charcoal,  or  other  form  of  carbon,  in 
fine  powder,  in  the  proportion  of  twelve  parts,  by  weight,  of  the  former  to  one  part  of 
the  latter,  and  introduce  the  mixture  into  a  retort,  made  red  hot,  and  furnished  with  an 
eduction  pipe  which  passes  through  cold  water  and  finally  enters  into  gas  liquor.  The 
formation  of  carbonic  acid  gas  soon  takes  place,  by  the  union  of  the  carbon  with  the 
oxygen  of  the  metal :  and  this  gas,  combining  with  the  base  of  the  hydrosulphate  of 
ammonia,  combined  in  the  gas  liquor,  converts  it  into  carbonate,  causing  hydrosulphuric 


a9o 


GAS-LIGHT. 


GAS-LIGHT. 


891 


acid  to  escape.  When  the  carbonic  acid  ceasea  to  come  away,  nearly  all  the  carbon 
will  have  disappeared  from  the  retort,  and  the  copper  which  it  contains  become  reduced 
to  thj  metallic  state.  The  charge  is  then  drawn  and  left  to  cool,  while  a  second  charge, 
of  aimilar  materials,  is  being  worked  off;  during  which  lime  the  copper  re-absorbs  oxygen 
from  the  air,  and  becomes  again  deutoxide  of  copper,  which  may  then  be  used  anew  with 
fresh  carbon. 

The  patentees  claim  making  carbonic  acid  gas  for  converting  hydrosulphate  of  am- 
monia into  carbonate  of  ammonia,  and  for  all  other  purposes  in  the  arts,  by  exposing  a 
proper  mixture  of  deutoxide  of  copper  and  carbon  in  powder  to  a  red  heat  in  suitable 
vessels. 

The  last  part  of  this  invention  is  a  pro(?)BS8  for  consilidating  peat  to  be  used  in  furnish- 
ing gas  or  charcoal,  or  for  feul.  The  process  is  as  follows :— The  peat,  without  being 
previously  dried,  is  treated  with  water  in  a  mill  in  a  way  similar  to  that  in  which  chalk 
ia  treated  for  the  manufacture  of  whitening,  and  which  is  well  understood.  The  resulting 
uquor  is  made  to  pass  through  a  strainer  of  wire-work  (tine  enough  to  prevent  the  pas- 
sage of  the  large  fabres)  into  tanks  or  backs,  cut  in  the  earth,  or  built  upon  the  surfiice  of 
the  ground  if  necessary  ;  where  it  is  left  to  deposit  the  finer  parts  of  the  peat.  When 
this  18  effected,  the  supernatent  liquor  is  run  off  from  the  deposit,  and  the  magma 
taken  out  from  the  tanks  or  backs  and  dried,  either  by  the  air,  by  the  sun,  or  on  arches 
of  brick  or  other  absorbent  material,  heated  by  flues  underneath. 

The  patentees  claim  under  this  head  the  separation  of  the  grosser  from  the  finer  parts 
of  the  peat,  and  the  consolidation  of  the  latter  by  the  process  above  described. 

Oan-light,  Purification  of.    The  purification  of  coal  gas  has  lately  received  one  of  those 
important  improvements,  which  constitute  an  era  in  the  practical  application  of  science  to 
the  arts.     From  the  commencement  of  the  manufacture  of  gas  up  to  a  very  recent 
period,  the  only  agent  in  use  for  the  removal  of  the  impurities  of  coal-gas  was  the 
hydrate  of  hme.     The  impurities  in  question  are,  as  is  well  known,  carbonic  acid  and 
sulphuretted  hydrogen  united  to  ammonia,  and  held  in  the  gas  more  by  a  principle  of 
diffusion  than  from  their  own  proper  volatility.      Hence  mere  condensation  bv  cold,  or 
the  application  of  water,  unless  both  of  these  are  employed  to  an  injurious  excess,  will 
not  combine  with  or  precipitate  the  bicarbonate  and  hydrosulphate  of  ammonia  present 
in  impure  coal  gas.    The  hydrate  of  lime,  however,  readily  decomposes  both  of  these 
salts,  with  the  production  of  carbonate  and  hydrosulphate  of  lime  and  the  liberation  of 
free  ammonia,  the  greater  part  of  which  may  subsequently  be  removed  bv  the  use  of  a 
dilute  acid,  or  the  application  of  cold  water  in  an  apparatus  similar  to'  the  "  cascade 
cheniique"  of  Clement  Desormes.     Thus,  then,  it  was  possible  by  lime  to  remove  the 
whole,  or  at  least  nearly  the  whole,  of  the  impurities  of  coal-gas,  and  as  we  have  before 
«tated.  this,  up  to  within  a  very  recent  date,  was  the  general  practice  whenever  coal-ffajt 
was  manufactured.     But  the  use  of  lime  in  this  way  entailed  many  and  serious  Sis 
advantages  in  a  sanitary  point  of  view,  to  obviate  or  rather  to  diminish  which  considerable 
outlay  was  incurred  in  large  towns,  for  it  is  a  property  of  the  hydrosulphate  of  lime  t« 
be  decomposed  with  singular  rapidity  by  carbonic  acid,  and  as  the  atmosphere,  more 
especially  in  crowded  localities,  always  contains  a  notable  proportion  of  this  latter  gas,  it 
follows  that  the  hydrosulphate  of  lime  begins  to  decompose  the  moment  it  comes  in  con« 
tact  with  the  air,  and,  consequently,  an  intolerable  nuisance  and   pestilential  effluvium 
were  tJms  originated,  not  only  in  the  neighbourhood  of  the  gas-works  themselves,  but 
also  in  those  localities  to  which  this  gas-lime  refuse  happened  to  be  transported ;  of  which 
a  lamentable  illustration  occurred  not  long  ago  in  Pimlico,  where  a  sewer  had  been 
covered  over  by  this  kind  of  refuse ;  and  though  three  or  four  years  had  intervened 
between  the  deposition  of  this  matter  and  the  accident  we  now  relate,  yet  no  less  than 
five  healthy  individuals  were  struck  dead,  as  if  by  lightning,  on  entering  the  sewer 
beneath  tiie  spot  where  the  refuse  lime  had  been  placed.     With  so  terrific  a  pr(K)f  of  the 
deleterious  action  of  the  hydrosulphate  of  lime,  even  after  many  years  had  elapsed  it 
becomes  superfluous  to  dwell  upon  the  necessity  whicli  existed  for  discontinuiiig  the 
formation  of  this  poisonous  substance,  and,  fortunately,  science  has  stepped  in  at  the 
eleventh  hour  to  the  relief  of  the  public. 

About  the  year  1847,  a  Mr.  Lamins:,  of  Paris,  took  out  a  patent  for  the  employment 
of  various  metallic  oxides  in  lieu  of  lime  for  the  purification  of  gas,  which  oxides 
were  used  at  the  same  time  or  in  combination  with  muriate  of  lime.  The  effect  of  this 
arrangement  was  two- fold,  for  as  we  have  seen  that  the  impurities  to  be  taken  away 
consist  of  ammonia,  carbonic  acid,  and  sulphuretted  hvdrogen,  then  by  the  use  of 
muriate  of  lime,  Mr.  Laming  was  able  to  remove  the"  carbonic  acid  and  ammonia, 
whilst  by  the  metallic  oxide  he  removed  the  sulphuretted  hydrogen ;  producing  in 
the  first  case  muriate  of  ammonia  and  carbonate  of  lime,  and  in  the  second  a  metallic 
sulphuret  and  water.  The  oxides  patented  were  those  of  manganese,  iron,  zinc,  and 
lead  ;  but  there  was  this  insuperable  difficulty  connected  with  their  employment,  that 
as  they  could  be  formed  only  by  the  decomposition  of  a  metallic  salt  and  its  equivalent 


of  lime,  they  necessarily  cost,  for  an  equal  amount  of  work  done,  the  whole  value  of  the 
lime  plus  that  of  the  metallic  salt.  The  expense  of  purification  by  this  plan,  therefore, 
stood  as  an  insurmountable  barrier  to  its  introduction,  though  the  peculiar  defect  of  lime 
was  entirely  got  rid  of  in  the  use  of  the  metallic  oxide,  as  this  did  not  suffer  decomposi- 
tion by  atmospheric  carbonic  acid,  and  therefore  evolved  no  sulphuretted  hydrogen. 
Nevertheless,  the  process  languished,  and  threatened  to  die  out  on  the  score  of  C(»st.  Mr. 
Laming's  first  essays  with  this  patent  seem  to  have  been  made  almost  entirely  with  the 
oxides  of  manganese  and  lead,  and  oxide  of  iron  does  not  appear  to  have  been  employed 
or  tried  on  a  large  scale  until  about  three  years  ago,  when,  in  conjunction  with  Mr. 
F.  J.  Evans,  of  the  Chartered  Gas  Works,  it  was  put  in  use  by  Mr.  Lamina  at 
Westminster.  The  success  of  the  experiment  was  complete  as  to  purification,  but  the 
question  of  expense  could  only  be  decided  by  a  few  consecutive  trials,  and  there- 
fore, fresh  materials  were  sent  for  this  purpose,  whilst  the  old,  or  as  it  was  called 
"spent"  material  was  cast  on  one  side.  During  the  progress  of  the  ensuing  experi- 
ments it  was,  however,  observed  by  Mr.  Evans,  that  this  spent  material,  consisting  as  it 
did  of  black  sulphuret  of  iron,  rapidly  regained  its  original  red  colour,  and  looked  like 
oxide  of  iron.  This  induced  him  to  give  it  another  trial  in  the  purifier,  when,  to  his 
astonishment,  he  discovered  that  its  purifying  power  was  completely  restored,  and  that, 
in  fact,  it  might  be  used  over  and  over  again,  10,  15,  or  20  times,  or  even  more  in  succes^ 
sion,  nothing  being  required  to  restore  its  power  but  a  few  hours'  exposure  to  the  air. 
From  that  moment  the  practical  employment  of  oxide  of  iron  in  the  purification  of  coal- 
gas  became  un  fait  accompli;  for  the  question  of  expense  was  altogether  done  away 
with  by  a  material  which,  though  costly  in  the  first  instance,  soon  ceased  to  be  so  from 
repeated  and  continuous  usage  without  additional  outlay.  And  it  is  here  worthy  of 
remark,  that  oxide  of  iron  is  the  only  oxide  yet  discovered  which  fully  answers  this 
purpose,  for  the  sulphurets  of  manganese,  zinc,  and  lead,  do  not  become  reconverted 
into  oxides  by  simple  exposure  at  ordinary  temperatures  to  the  action  of  the  air.  And 
as  oxide  of  iron  is  contained  in  the  blood  of  all  animals,  it  opens  out  an  interesting 
question  in  physiology,  how  far  this  gas  purification  process  may  be  analogous  to  that 
ot  the  blood,  through  the  agency  of  the  pulmonary  system.  We  shall  now,  however, 
merely  give  a  condensed  view  of  the  oxide  of  iron  method,  as  practised  at  the  West- 
minster and  other  g:as  works,  without  offering  more  than  a  few  brief  theoretical  remarks 
by  way  of  explanation. 

Impure  coal-gas,  as  it  leaves  the  condenser,  contains  about  two  per  cent,  in  bulk  of 
carbonic  acid,  and  one  per  cent,  of  sulphuretted  hydrogen,  with  a  quantity  of  ammonia, 
generally  insufficient  to  saturate  these  two  acids",  though  this  varies  much  with  the 
variations  of  the  weather  and  the  state  of  the  condenser.  For  the  most  part,  however, 
the  amount  of  ammonia  is  equal  to  the  carbonic  acid,  and  in  this  case  the  new  process  is' 
perfect;  but  if  the  ammonia  be  less  than  will  saturate  the  carbonic  acid,  then  the  excess 
of  this  acid  remains  in  the  gas,  and  to  this  extent  the  coal-gas  may  be  said  to  be  impure. 
Taking  the  normal  conditi«»n  of  gas  as  it  quits  the  condenser,  it  is  first  made  to  traverse 
a  quantity  of  sawdust,  saturated  with  a  very  strong  solution  of  muriate  of  lime. 
Here  double  decomposition  goes  on,  accompanied  by  the  formation  of  cjirbonate  of 
liu)e  and  muriate  of  ammonia,  and  the  gas  becomes  deprived  of  its  carbonic  acid  and 
ammonia,  consequently  it  now  contains  only  sulphuretted  hydrogen ;  and  when  the 
niuriate  of  lime  in  the  sawdust  is  totally  decomposed,  the  muriate  of  ammonia  which 
it  then  contains  is  dissolved  out  by  lixiviation,  and  crystallised  as  a  marketable  product 
The  impure  gas  is  next  transmitted  through  a  mixture  of  the  hydrated  peroxide  of  iron 
and  sawdust,  damped  with  a  solution  of  muriate  of  lime,  by  which  the  whole  of  the 
sulphuretted  hydrogen  is  absorbed,  and  also  any  traces  of  carbonate  of  ammonia  which 
may  have  escaped  the  first  purifier.  In  this  way  the  peroxide  of  iron  is  reduced  to  the 
state  of  protoxide,  with  the  formation  of  water  and  deposition  of  half  an  atom  of 
sulphur,  whilst  the  protoxide  of  iron  as  it  is  produced  reacts  upon  the  remaining 
sulphurerted  hydrogen,  and  yields  a  hydrated  proto-sulphuret  of  iron  of  a  black  colour, 
BO  that  the  resulting  products  are  water,  sulphur,  and  hydrated  protosulphate  of  iron! 
So  soon,  however,  as  these  are  exposed  to  the  air,  the  iron  of  the  protosulphuret  com- 
bines with  t)xygen  and  liberates  free  sulphur,  whilst  it  nevertheless  retains  the  water  of 
combination  belonging  to  the  protosulphuret,  thus  generating  a  mixture  of  hydrated 
and  anhydrous  peroxide  of  iron ;  and  as  it  is  the  former  of  tiiese  alone  which  is  use- 
ful in  purification,  there  is  after  each  renewal  a  slight  loss  of  power,  and  this  slowly 
increasing  ultimately  renders  the  whole  mass  inefficacious  after  from  18  to  20  expo- 
sures. At  the  same  time  the  free  sulphur  in  the  material  goes  on  augiuenting,  and 
at  last  a  period  arrives  in  which  the  mixture  becomes  pyrophor.c,  and  it  is  almost  impos- 
sible to  prevent  it  from  catching  fire.  The  effect  of  the  muriate  of  lime  is  to 
diminish  this  tendency  ;  but  this  gives  rise  to  the  presence  of  carbonate  of  lime,  as 
we  have  seen  alxive,  and  when  much  carbonate  of  lime  has  made  its  appearance,  then 
the  di8po8iti«»n  of  the  sulphur  to  form  sulphuric  acitl  is  increaseil  by  the  readiness  fur  Its 
absorption  by  the  carbonate  of  lime,  and  therefore  the  proneness  to  inflammation  is 


892 


GAS-LIGHT. 


again  manifested ;  so  that  in  practice  a  small  specimen  of  this  material  is  seldom  used 
more  than  twenty  times  in  succession  before  it  is  removed  from  tlje  gas  works.  It  is, 
however,  now  very  far  from  being  valueless,  as  it  not  only  contains  a  vast  amount  of  free 
sulphur,  but  also  of  ferrocyanic  acid ;  a  product  scarcely  to  have  been  expected  in  a  com- 
mercial sense.  Nevertheless,  it  is  found  that  one  ton  of  Newcastle  coals  gives  oflf  in 
distillation  sufficient  cyanogen  to  produce  from  5  to  8  lbs.  of  Prussian  blue  with  the 
hydrated  oxide  of  iron ;  and  it  is  part  of  the  process  now  carried  on  by  Mr.  Laming  at 
Mill  Wall,  to  extract  this  ferrocyanic  acid  from  the  spent  material,  and  convert  it  into 
prussiate  of  potash  or  Prussian  blue  at  pleasure.  The  great  advantage  of  this  invention 
IS  not  therefore  confined  to  its  sanitary  details,  but  extends  into  the  merit  of  having  dis- 
covered a  new  and  fertile  source  for  the  production  of  an  article  of  great  commercial 
value,  and  rendered  both  useful  and  profitable  that  which  was  previously  a  pestilential 
waste  threatening  to  interfere  very  seriously  with  the  progress  of  gas  manufacturing.— 
Mr.  L.  Thompaon. 

Lowe  and  Evans's  Improvements.  On  the  20th  January,  1852,  a  patent  was  granted  to 
George  Lowe,  of  Finsbury-circus,  in  the  city  of  London,  civil  engineer,  and  Frederick 
John  Evans,  of  Horseferry  Road,  in  the  city  of  Westminster,  civil  engineer,  for  improve- 
ments in  the  manufacture  of  gas  for  the  purpose  of  illumination,  and  of  improvements  in 
the  purification  of  gas. 

The  first  part  of  this  invention  refers  to  certain  means  of  enriching  or  improving  the 
quality  of  gases,  so  as  to  render  them  fit  for  the  purposes  of  illuminatioa 

In  carrying  out  this  improved  manufacture  of  gas,  the  patentees  pass  gas.  obtained 
from  any  of  the  sources  hereinafter  specified,  through  heated  retorts  containing  cannel 
coal,  coal,  lignite,  resin,  pitch,  tar,  oil,  retinite,  or  other  substance  or  8ubstai»ces°capable 
of  yielding  carburetted  hydrogen  gas:  by  which  means  such  a  combination  of  rich  and 
poor  gases  may  be  produced  as  will  be  exactly  suited  to  the  purposes  of  illuminatioa 
For  this  purpose,  it  is  proposed  to  use  retorts  open  at  both  ends,  as  shown  in  the  draw- 
ing given  in  jig.  705.,  which  represents  a  longitudinal  vertical  section  of  the  apparatus 

employed  in  carrying  out  this  part  of  the  in- 
vention. Only  one  retort  is  exhibited  ;  but 
a  similar  arrangement  of  retorts  may  be 
adopted  to  that  in  general  use  in  gas-works. 
a  is  the  retort,  set  in  a  suitable  furnace  for 
heating  the  same  ;  and  b,  b  are  mouth- pieces 
and  lids,  fitted  to  both  ends  of  the  retorts,  c 
is  the  pipe  for  carrying  off  the  gaseous  pro- 
ducts generated  in  the  retort;  and  d,  is  a  pipe 
for  introducing  into  the  retort  the  gas  which 
is  intended  to  combine  with  the  gaseous  pro- 
ducts of  the  substances  under  distillation  in 
tlie  retort.  As  soon  as  the  retort  is  charged 
with  coal  or  other  carbonaceous  matter,  a  cock 
c,  in  the  pipe  d,  is  opened,  which  allows  the 
gas  to  flow  into  the  retort ;  and  it  then  passes 
in  the  direction  of  the  arrows,  and  mingles 
with  the  gas  that  is  evolved  from  the  carbo- 
naceous matters  contained  in  the  retort :  whereby  a  compound  gas  is  formed,  possessing 
a  much  hiji:her  illuminatinj?  power  than  could  have  been  obtained  had  the  combination 
taken  place  after  instead  of  at  the  time  of  the  generation  of  the  gas  in  the  retort  a.  The 
gas,  which  is  brought  to  the  retort  by  means  of  the  pipe  d,  may  be  forced  into  the  retort, 
so  as  to  overcome  the  internal  pressure  put  on  the  retort  by  means  of  the  hydraulic 
main ;  or,  instead  thereof,  an  exhauster  may  be  applied  to  draw  off  the  gas  from  the 
retort.  Should  tar,  oil,  resin  (previously  melted),  or  any  liquid  hydrocarbon  be  employed 
for  the  generation  of  the  gas,  it  is  to  be  run  into  the  retort  in  the  way  generally  adopted 
for  making  oil  or  resin  gas. 

The  sources  from  which  the  patentees  propose  to  obtain  inflammable  gases,  to  be 
applied  as  above  indicated,  are  wood,  sawdust  in  a  damp  or  dry  state,  spent  tanner's 
bark,  and  other  like  substances  capable  of  yielding  an  inflammable  gas.  These  substances 
must  be  put  into  a  red-hot  retort,  and  distilled  like  coal.  The  resulting  gases  may  be 
either  purified  at  once,  or  passed  directly  to  the  retort  containing  the  coal  or  other  car- 
bonaceous materials.  As  a  general  rule,  however,  these  gases  are  preferred  to  be  stored 
in  gas  holders  for  use  ;  as,  in  that  case,  a  more  uniform  and  constant  supply  to  the  coal 
retort  may  be  relied  on. 

Another  source  of  inflammable  gas  is  from  coal  of  an  inferior  description,  or  from 
peat-  Tliese  substances  having  been  distilled  in  a  retort,  the  resulting  gas  can  l>e  then 
employed  as  above  indicated.  It  is  also  proposed  to  conduct  carbonic  oxide  gas  into 
retorts  containing  carbonaceous  matters  under  distillation.  This  gas  the  patentees 
obtain  from  carbonic  acid,  by  passing  the  latter  gas  (which  may  be  obtained  from  any 


GAS-LIGHT. 


893 


convenient  source)  through  a  retort  or  furnace  containing  red  or  white  hot  coka  Or, 
they  utilize  a  portion  of  the  gases  generated  in  furnaces,  by  collecting  these  gases  and 
converting  the  carbonic  acid  they  contain  into  carbonic  oxide,  by  passing  them  through 
a  retort  or  furnace,  as  descril)ed  for  treating  carbonic  acid ;  or  the  gases  may  be  con- 
ducted directly  into  retorts,  wherein  carburetted  hydrogeu  is  being  generated,  for  the 
purpose  of  effecting  the  desired  combination. 

From  the  foret'oing  description,  it  will  be  understood,  that  the  object  of  this  part  of 
the  invention  is  to  obtain  gas  of  a  uniform  quality, — that  is,  possessing  a  definite  amount 
of  illuminating  power.  Now,  it  is  well  known  that  if  the  gas  be  too  rich  in  carbon  it 
will  burn  with  a  dull  flame,  and  give  off  a  large  amount  of  smoke  ;  and  that,  if  deficient 
in  carbon,  it  will  burn  with  a  blue  flame,  and  possess  very  little  illuminating  power. 
It  is  therefore  proposed  to  mix  the  rich  and  poor  gases,  obtained  as  above  described,  in 
such  proportions  as  will  be  needful  to  produce  a  highly  illuminating  quality  of  gas. 
As  the  proportions  will  depend  entirely  on  the  quality  of  the  gases  to  be  combined,  no 
rule  can  be  laid  down  for  the  aniount  of  the  gas  required  to  be  passed  into  the  retorts, 
wherein  the  distillation  is  proceeding.  The  mode,  however,  in  which  the  gas  burns,  on 
issuing  from  the  retort,  will  be  a  sufiicient  test  for  the  workmen  in  attendance. 

The  second  part  of  this  invention  refers  to  the  purification  of  coal  gas  from  sulphu- 
retted hydrogen  ;  and  consists  in  effecting  this  operation  by  the  use  of  what  has  been 
considered  by  chemists  to  be  the  ferrate  of  potash,  but  what  is  now  found  to  be  a  per- 
oxide of  iron  in  a  peculiar  state,  and  such  as  results  from  the  employment  of  the  follow- 
ing means : — First  the  patentees  heat  together  peroxide  of  iron  and  caustic  potash  or 
soda  to  a  dull  red  heat,  by  which  a  kind  of  ferrate  or  ferrite  of  potash  or  soda  is  pro- 
duced ;  and  when  this  substance  is  washed  in  water,  it  undergoes  decomposition,  with 
the  reproduction  of  caustic  potash  or  soda  (which  remains  in  solution),  and  the  precipi- 
tation of  peroxide  of  iron  in  the  state  fit  for  the  purification  of  gas.  All  or  any  of  the 
peroxides  of  iron  may  be  used  for  the  above  purposes,  and  will,  by  its  means,  become 
useful  for  purifying  gas,  though  previously  inert ;  and  the  solution  of  potash  or  soda, 
when  evaporated  to  dryness,  may  be  again  and  again  employed  upon  fresh  portions  of 
peroxide  of  iron,  so  as  to  communicate  to  them  the  peculiar  property  desired.  Or  per- 
oxide of  iron  may  be  heated  with  a  smaller  quantity  of  caustic  potash  or  soda,  and  a 
portion  of  common  salt,  in  order  to  economize  the  potash  or  soda:  the  heat  in  this  case 
should  be,  as  before,  a  dull  red ;  and  the  same  measures  must  be  adopted  for  recovering 
the  potash  or  soda  and  common  salt,  which  may  be  used  over  and  over  again  with  fresh 
portions  of  peroxide  of  iron.  Or  the  patentees  heat  the  common  hydrated  peroxide  of 
iron,  to  about  600o  Fahr., — taking  care  that  the  heat  never  reaches  a  bright  red ;  and 
in  this  way  they  obtain  a  peroxide  of  iron,  having  the  requisite  properties.  Or  they 
heat  in  the  same  way,  and  with  the  same  precautions,  such  of  the  native  ochres  or  ferru- 
ginous compounds  as  will,  after  such  treatment,  become  rapidly  black  upon  being  sub- 
jected to  the  action  of  a  stream  of  sulphuretted  hydrt^en. 

A  quantity  of  peroxide  of  iron,  fit  for  purifying  gas,  having  been  procured,  by  any 
of  the  means  thus  indicated,  the  oxide  is  next  to  be  mixed  with  sawdust  or  other  con- 
venient material,  and  damped  slightly  with  water  ;  and  the  mixture  is  then  to  be 
spread  in  a  dry  lime  purifier,  and  used  in  the  way  adopted  with  hydrate  of  lime ;  or  it 
may  be  mixed  with  water,  and  run  into  a  wet  lime  purifier,  and  used  in  the  way  adopt- 
ed with  regard  to  lime  when  employed  in  this  kind  of  apparatus.  In  both  cases  it  will 
be  necessary,  after  the  peroxide  of  iron  has  ceased  to  act  upon  the  gas,  to  expt>se  it  to 
the  air,  by  which  its  energies  are  renewed,  so  that  it  may  be  again  and  again  used  for 
the  purification  of  gas.  With  the  dry  lime  purifier,  simple  exposure  is  all  that  is  re- 
quired. With  the  wet  lime  purifier,  the  mixture  must  be  run  out  and  left  at  rest  for 
some  time ;  then,  when  the  fluid  has  entirely  separated  from  the  solid  part,  it  may  be 
allowed  to  escape ;  and  as  the  solid  portion  dries,  its  power  will  become  renewed  :  after 
which  it  may  be  mixed  with  water  and  employed  as  before.  The  renewal  of  the  peroxide 
of  iron,  in  both  these  cases,  is  known  by  its  changing  from  black  to  red  or  deep  brown. 

Another  part  of  the  invention  relates  to  the  use  of  the  sulphite  and  bisulphite  of  lead 
for  the  removal  of  the  sulphuretted  hydrogen  from  coal-gas. 

These  substances  are  to  be  employed  singly  or  together,  mixed  with  water,  in  a  wet 
lime  purifier,  exactly  as  is  practised  with  regard  to  lime.  When  they  cease  to  purify 
the  gas,  the  mixture  is  run  out  of  the  purifier ;  and  after  the  water  has  been  removed 
by  subsidence  and  decantation,  or  by  a  filter,  the  residue  is  dried  and  burned,  so  as  to 
make  sulphurous  acid,  which  is  employed  in  the  manufacture  of  fresh  sulphite  or  bi- 
sulphite of  lead,  or  in  the  production  of  sulphuric  acid.  The  matter  which  remains, 
after  this  burning  process,  is  carefully  roasted,  and  thus  converted  into  oxide  of  lead  or 
litharge,  from  which  sulphite  or  bisulphite  of  lead  may  be  again  produced. 

The  patentees  claim  the  combining  of  gases  which  possess  different  degrees  of  illu- 
minating power,  by  the  introduction  of  gas,  obtained  in  any  of  the  ways  above  iihlicate»| 
into  retorts  or  vessels  containing  carbonaceous   matters  under  distillation.     They  also 


894 


GELATINE. 


claim,  as  their  improvements  in  the  purification  of  gas,  First, — the  use  of  anhydrous  per- 
oxide of  iron  prepared  as  above  described ;  and.  Secondly, — the  use  of  sulphite  and  bisulphite 
of  lead,  for  the  removal  of  sulphuretted  hydn^en  from  coal-gas. — Neioton's  Journal. 

We  are  indebted  to  Mr.  Thomas  G.  Barlow,  an  eminent  engineer,  for  a  vast  body  of 
information  on  coal-gas,  contained  in  his  excellent  Journal  of  Gas  Lighting,  commenced 
on  the  10th  of  February,  1849,  and  continued  in  monthly  numbers  ever  since.  His  first 
number  presented  a  list  of  the  London  Gas  Companies,  and  the  value  of  their  shares  at 
the  Stock  Exchange,  to  which  we  have  added  the  ruling  rates  in  the  present  year. 


Paid  up. 


£ 
25 
160 
60 
50 
50 
50 
60 
50 
49 
90 
25 


Name. 


Commercial  .  -  - 
City  of  London  -  - 
Chartered  -  -  -  - 
Equitable     -     -     -     - 

Imperial 

Independent  -  -  - 
London  (Vauxhall)  - 
Ditto  (preference) 

Phoenix 

Ratcliff 

South  Metropolitan   - 


January,  1848. 


£  £ 

25  to  26 
285  —  290 
58—  69 
38—  39 
80—   84 


35  J  to  86J 
18  —  80 
28  —  80 


January,  1849. 


£  £ 

25  to  26 
240  —  245 

48—  49 

33—  35 

62—  64 

60—  62 

10—  20 

20—  SO 
28—  30 
72—  74 

21—  23 


September,  1852. 


£ 
30 
124 

36  — 

26  — 

76  — 

46  — 

2i- 

15  — 

26  — 

60  — 

20  — 


£ 
to  32 

—  126 

—  87 

—  26 

—  80 

—  47 
3 

18 
27 
65 
22 


GENERAL  SUMMARY. 

For  lighting  London  and  its  suburbs  with  gas,  there  are  — 
18  public  gas  works. 
12         do.         companies. 

2,800.000/.  capital  employed  in  works,  pipes,  tanks,  gas-holders,  apparatua 
450,000/.  yearly  revenue  derived. 

134,300  private  burners  supplied  to  about  40,000  consumers. 
30,400  public  or  street  do.     N.  B.  about  2650  of  these  are  in  the  citt/  of  London. 
380  lamplighters  employed. 

176  gas-holders;  several  of  them  double  ones,  capable  of  storing  6,500,000  cubic  feet 
890  tons  of  coal  used  in  the  retorts  on  the  shortest  day,  in  24  hours. 
7,120,000  cubic  feet  of  gas  used  in  the  longest  night,  24th  December. 
About  2500  persons  are  employed  in  the  metropolis  alone,  in  Uiis  branch  of  manu- 
facture. 

Between  1822  and  1827  the  quantity  nearly  doubled  itself,  and  that  in  5  years. 

Between  1827  and  1837  it  doubled  itself  again. 

ITie  consumption  of  coals  of  all  kinds  for  the  supply  of  gas  to  the  metropolis  during 
the  year  ending  June,  1852,  is  almost  exactly  408,000  tons,  which  on  an  average  would 
yield  al)out  4.000  millions  of  cubic  feet  of  gas. 

GASHOLDER;  a  vessel  for  containing  and  preserving  gas,  of  which  various  forms 
are  described  by  chemical  writers. 

GASOMETER,  means  properly  a  measurer  of  gas,  though  it  is  employed  often  to 
denote  a  recipient  of  gas  of  any  kind.     See  the  article  Gas-Light. 

GAUZE  WIRE  CLOTH,  is  a  textile  fabric,  either  plane  or  tweeled,  made  of 
brass,  iron,  or  copper  wire,  of  very  various  degrees  of  fineness  and  openness  of  textureat 
Its  chief  uses  are  for  sieves  and  safety  lamps. 

GAY-LUSSITE,  is  a  white  mineral  of  a  vitreous  fracture,  which  crystallizes  in 
oblique  rhomboidal  prisms;  specific  gravity  from  1-93  to  1-95;  scratches  gvpsum,  but 
is  scratched  by  calcspar  ;  affords  water  by  calcination  ;  it  consists  of  carbonic  acid 
28-66;  soda,  20  44;  lime,  1770;  water,  8220;  clay,  100.  It  is  in  fact,  by  my  ana- 
lysis, a  hydrated  soda-carbonate  of  lime  in  atomic  proportions.  This  mineral  occurs 
abundantly  in  insulated  crystals,  disseminated  through  the  bed  of  clay  which  covers  the 
nrao,  or  native  sesquicarbonate  of  soda,  at  Lagunilla  in  Columbia. 

GELATINE ;  (Eng.  and  Fr. ;  Gallert,  Leitn,  Germ.)  is  an  animal  product  which  is 
never  found  in  the  humours,  but  it  may  be  obtained  by  boiling  with  water  the  soft  and 
solid  parts;  as  the  muscles,  the  skin,  the  cartilages,  bones,  ligaments,  tendons,  and  mem- 
iM^nes.  Isinglass  consists  almost  entirely  of  gelatine.  This  substance  is  very  soluble  in 
boiling  water;  the  solution  forms  a  tremulous  mass  of  jelly  when  it  cools.  Cold  water 
has  little  action  upon  gelatine.  Alcohol  and  tannin  (tannic  acid,  see  Gall-nuts)  pre- 
cipitate gelatine  from  its  solution;  the  former  by  abstracting  the  water,  the  latter  by 
combining  with  the  substance  itself  into  an  insoluble  compound,  of  the  nature  of  leather. 
No  other  acid,  except  the  tannic,  and  no  alkali,  possesses  the  property  of  precipitating 


GELATINE. 


895 


gelatine.  But  chlorine  and  certain  salts  render  its  solution  more  or  less  turbid ;  as  the 
nitrate  and  bi-chloride  of  mercury,  the  proto-chloride  of  tin,  and  a  few  others. 
Sulphuric  acid  converts  a  solution  of  gelatine  at  a  boiling  heat  into  sugar.  See 
Ligneous  Fibee.  Gelatine  consists  of  carbon,  47*88 ;  hydrogen,  7*91  ;  oxygen,  27'21. 
See  Glue  and  Isinglass. 

This  substance  is  produced  by  boiling  the  skin  of  animals  in  water,  which  in  its 
crude  but  solid  state  is  called  glv^,  and  when  a  tremulous  semi-liquid,  size.  The 
latter  preparation  is  greatly  used  by  the  paper-makers,  and  was  much  improved  by  the 
following  process,  for  which  Mr.  William  Rattray  obtained  a  patent  in  May,  1838.  The 
parings  and  scrows  of  skins  are  steeped  in  water  till  they  begin  to  putrefy  ;  they  are 
then  washed  repeatedly  in  fresh  water  with  the  aid  of  stampers,  afterwards  subjected,  in 
wooden  or  leaden  vessels,  to  the  action  of  water  strongly  impregnated  with  sulphurous 
acid  for  from  12  to  24  hours;  they  are  now  drained,  washed  with  stampers  in  cold 
water,  and  next  washed  with  water  of  the  temperature  of  120°  F.,  which  is  poured  upon 
them  and  run  off  very  soon  to  complete  their  purification.  The  scrows  are  finally  con- 
verted into  size,  by  digestion  in  water  of  120°  for  24  hours;  and  the  solution  is  made 
perfectly  fine  by  being  strained  through  several  thicknesses  of  woollen  cloth.  They  must 
be  exhausted  of  their  gelatinous  substance,  by  repeated  digestions  in  the  warm  water. 
The  claim  is  for  the  sulphurous  acid  which,  while  it  cleanses,  acts  as  an  antiseptic. — 
Netoton^s  Journal,  xiv.  173. 

A  fine  gelatine  for  culinary  uses,  as  a  substitute  for  isinglass,  is  prepared  by  Mr. 
Nelson's  patent,  dated  March,  1839.  After  washing  the  Darings,  <fec.,  of  skin,  he  scores 
their  surfaces,  and  then  digests  them  in  a  dilute  caustic  soda  lye  during  ten  days. 
They  are  next  placed  in  an  air-tight  vat,  lined  with  cement,  kept  at  a  teinperatiire  of 
70°  Fahr. ;  then  washed  in  a  revolving  cylinder  apparatus  with  plenty  of  cold  water,  and 
afterwards  exposed  to  the  fumes  of  burning  sulphur  (sulphurous  acid)  in  a  wooden 
chamber.  They  are  now  squeezed  to  expel  the  moisture,  and  finally  converted  into 
soluble  gelatine,  by  water  iu  earthen  vessels,  enclosed  in  steam  cases.  The  fluid  gelatine 
is  purified  by  straining  it  at  a  temperature  of  100°  or  120°  Fahr.  I  have  examined  this 
patent  gelatine,  and  found  it  to  be  remarkably  good,  and  capable  of  forming  a  fine 
calfs-foot  jelly. 

Very  recently  a  very  beautiful  sparkling  gelatine  has  been  prepared  under  a  patent 
granted  to  Messrs.  J.  and  G.  Cox,  of  Edinburgh.  By  their  process  the  substance  is 
rendered  perfectly  pure,  while  it  possesses  a  gelatinizing  force*feuperior  even  to  isinglass. 
It  makes  a  splendid  calves'-feet  jelly  and  a  milk-white  blanc-mange.  The  patentees  also 
prepare  a  semi-solid  gelatine,  resembling  jujubes,  which  readily  dissolves  in  warm 
water,  as  also  in  the  mouth,  and  may  be  employed  to  make  an  extemporaneous  jelly. 

The  gelatine  of  bones  may  be  extracted  best  by  the  combined  action  of  steam 
and  a  current  of  water  trickling  over  their  crushed  fragments  in  a  properly  con- 
structed apparatus.  When  the  gelatine  is  to  be  used  as  an  alimentary  article,  the 
bones  ought  to  bo  quite  fresh,  well  preserved  in  brine,  or  to  be  dried  strongly  by  a 
stove.  Bones  are  best  crushed  by  passing  them  between  grooved  iron  rolls.  The 
cast-iron  cylinders  in  which  they  are  to  be  steamed,  should  be  three  times  greater  in 
length  than  in  diameter.  To  obtain  1000  rations  of  gelatinous  soup  daily  a  charge 
of  four  cylinders  is  required ;  each  being  3^  feet  long,  by  14  inches  wide,  capable  of 


896 


GELATINE. 


holding  70  lbs.  of  bones.  These  will  yield  ejich  hour  about  20  gallons  of  a  strong 
jelly,  and  will  require  nearly  1  gallon  of  water  in  the  form  of  steam,  and  5  gallons 
of  water  to  be  passed  through  thera  in  the  liquid  state.  The  5  quarts  of  ielly  pro- 
duced honrly  by  each  cylinder,  proceeds  from  the  1  quart  of  steam-water  and  4  quarts 
of  percolating  water. 

The  boiler  should  furnish  steam  of  about  223°  Fahr.,  at  a  pressure  of  about  4  lbs. 
on  the  square  inch. 

In  fig.  706.  a,  b,  c,  d,  represents  a  vertical  section  of  the  cylinder ;  o,  h,  i,  k,  a 
■ection  of  the  basket  or  cage,  as  filled  with  the  bruised  bones,  inclosed  in  the  cylinder  ; 
E,  c,  c,  the  pipe  which  conducts  the  steam  down  to  the  bottom  of  the  cylinder ;  l,  s, 
a  pipe  for  introducing  water  into  the  interior ;  m,  a  stopcock  for  regulating  the 
quantity  of  water  (according  to  the  force  of  the  steam  pressure  within  the  apparatus), 
which  should  be  3^  quarts  per  hour ;  n  is  a  tube  of  tin  plate  fitting  tightly  into  the 
part  s  of  the  pipe  l;  it  is  shut  at  r,  and  perforated  below  with  a  hole;  it  is 
userted  in  its  place,  after  the  cage  full  of  bones  has  been  introduced.    Fig.  707.  is  an 


elevation  of  the  apparatus,  a,  b,  c,  d,  represent  the  four  cylinders,  raised  about 
20  inches  above  the  floor,  and  fixed  in  their  seats  by  screws ;  h  h,  are  the  lids  • 
g,  g,  tubulures  or  valves  in  the  lids ;  «,  ring  junction  of  the  lid ;  p,  a  thermometer ; 
/,  /,  stop-cocks  for  drawing  off  the  jelly,  n,  n  small  gutters  of  tin  plate;  m,  the 
general  gutter  of  discharge  into  the  cistern  5  ;  o,  a  block  and  tackle  for  hoisting  the 
cageful  of  bones  in  and  out.     Fig,  708.  is  an  end  view  of  the  apparatus ;  a,  the  main 

steam-pipe ;  a,  h,  c,  c,  branches  that  conduct  that 
steam  to  the  bottom  of  the  cylinder;  o,  the 
tsickle  for  raising  the  cage ;  »,  stopcock ;  n,  small 
gutter ;  m,  main  conduit ;  h,  cistern  of  reception. 
When  a  strong  and  pure  jelly  is  wished  for, 
the  cylinder  charged  with  the  bones  is  to  be 
wrapped  in  blanket  stuff;  and  whenever  the 
grease  ceases  to  drop,  the  stopcock  which  admits 
the  cold  water  is  to  be  shut,  as  also  that  at  the 
bottom  of  the  cylinder,  which  is  to  be  opened  only 
at  the  end  of  every  hour,  and  so  little  as  to  let 
the  gelatinous  solution  run  out,  without  allow 
ing  any  of  the  steam  to  escape  with  it. 

Butchers'  meat  contains  on  an  average  in  100 
pounds,  24  of  dry  flesh,  56  of  water,  and  20  of 
bones.  These  20  pounds  can  furnish  6  pounds 
of  alimentary  substance  in  a  dry  state ;  whence 
it  appears  that,  by  the  above  means,  one  fourth 
more  nutritious  matter  can  be  obtained  than  is 
usually  got.  I  am  aware  that  a  keen  dispute 
has  been  carried  on  for  some  time  in  Paris,  be- 
tween the  partisans  and  adversaries  of  gelatine 
as  an  article  of  food.  It  is  probable  that  both 
parties  have  pushed  their  arguments  too  far. 
Calf's-foot  jelly  is  still  deemed  a  nutritious 
article  by  the  medical  men  of  tliis  country,  at  least,  though  it  is  not  to  be  trusted 


GERHARDT'S  ACETIC  ACID. 


897 


to  alone,  but   should    have  a  due    admixture  or   interchange  of  fibrine,   albumine, 
caseum,  &c. 

GEMS,  are  precious  stones,  which,  by  their  colour,  limpidity,  lustre,  brilliant  polish, 
purity,  and  rarity,  are  sought  after  as  objects  of  dress  and  decoration.  They  form  the 
principal  part  of  the  crown  jewels  of  kings,  not  only  from  their  beauty,  but  because  they 
are  supposed  to  comprise  the  greatest  value  in  the  smallest  bulk ;  for  a  diamond,  no 
larger  than  a  nut  or  an  acorn,  may  be  the  representative  sign  of  the  territorial  value  of  a 
whole  country,  the  equivalent  in  commercial  exchange  of  a  hundred  fortunes  acquired  by 
severe  toils  and  privations. 

Among  these  beautiful  minerals  mankind  have  agreed  in  forming  a  select  class,  to 
which  the  title  of  gems  or  Jewels  has  been  appropriated  ;  while  the  term  precious  stone  is 
more  particularly  given  to  substances  which  often  occur  under  a  more  considerable 
volume  than  fine  stones  ever  do. 

Diamonds,  sapphires,  emeralds,  rubies,  topazes,  hyacinths,  and  chrysoberyls,  are  reck- 
oned the  most  valuable  gems. 

Crystalline  quartz,  pellucid,  opalescent  or  of  various  hues,  amethyst,  lapis  lazuli, 
malachite,  jasper,  agate,  <fec.,  are  ranked  in  the  much  more  numerous  and  inferior  class  of 
ornamental  stones.  These  distinctions  are  not  founded  upon  any  strict  philosophical 
principle,  but  are  regulated  by  a  conventional  agreement,  not  very  well  defined ;  for  it  is 
impossible  to  subject  these  creatures  of  fashion  and  taste  to  the  rigid  subdivisions  of 
science.  We  have  only  to  consider  the  value  currently  attached  to  them,  and  take  care 
not  to  confound  two  stones  of  the  same  colour,  but  which  may  be  very  differently  prized 
by  the  virtuoso. 

Since  it  usually  happens  that  the  true  gems  are  in  a  cut  and  polished  Hate,  or  even  set 
in  gold  or  silver,  we  are  thereby  unable  to  apply  to  them  the  criteria  of  mineralogical 
and  chemical  science.  The  cutting  of  the  stone  has  retnoved  or  masked  its  crystalline 
character,  and  circumstances  rarely  permit  the  phenomena  of  double  or  single  refraction 
to  be  observed ;  while  the  test  by  the  blowpipe  is  inadmissable.  Hence  the  only 
scientific  resources  that  remain  are  the  trial  by  electricity,  which  is  often  inconclusive ; 
the  degree  of  hardness,  a  criterion  requiring  great  experience  in  the  person  who  employs 
it ;  and,  lastly,  the  proof  by  specific  gravity,  unquestionably  one  of  the  surest  means  of 
distinguishing  the  really  fine  gems  from  ornamental  stones  of  similar  colour.  This  proof 
can  be  applied  only  to  a  stone  that  is  not  set ;  but  the  richer  gems  are  usually  dis- 
mounted when  offered  for  sale. 

This  character  of  specific  gravity  may  be  applied  by  any  person  of  common  intelligence, 
with  the  aid  of  a  small  hydrostatic  balance.  If,  for  example,  a  stone  of  a  fine  crimson-red 
colour,  be  offered  for  sale,  as  an  oriental  ruby,  the  purchaser  must  ascertain  if  it  be  not 
a  Siberian  tourmaline,  or  ruby  spinel.  Supposing  its  weight  in  air  to  be  100  grains,  if  he 
finds  it  reduced  to  69  grains,  when  weighed  in  water,  he  concludes  that  its  bulk  is  equal 
to  that  of  31  grains  of  water,  which  is  its  loss  of  weight.  Now,  a  real  sapphire  which 
weighs  100  grains  in  air,  would  have  weighed  766  in  water ;  a  spinel  ruby  of  100  grains 
would  have  weighed  72'2  in  water,  and  a  Siberian  tourmalme  of  100  grains  would 
have  weighed  only  69  grains  in  water.  The  quality  of  the  stone  in  question  is, 
therefore,  determined  beyond  all  dispute,  and  the  purchaser  may  be  thus  protected  from 
fraud. 

The  sard  of  the  English  jewellers  {Sardoine,  French)  is  a  stone  of  the  nature  of  agate, 
having  an  orange  colour  more  or  less  deep,  and  passing  by  insensible  shades  into  yellow, 
reddish,  and  brown ;  whence  it  has  been  agreed  to  unite  under  this  denomination  all  the 
agates  whose  colour  verges  upon  brown.  It  should  be  remarked,  however,  that  the  sard 
presents,  in  its  interior  and  in  the  middle  of  its  ground,  concentric  zones,  or  small 
nebulosities,  which  are  not  to  be  seen  in  the  red  cornelian,  properly  so  called.  The 
ancients  certainly  knew  our  sard,  since  they  have  left  ua  a  great  many  of  them  engraved, 
but  they  seem  to  have  associated  under  the  title  sarda  both  the  sardoine  of  the  French, 
and  our  cornelians  and  calcedonies.  Pliny  says  that  the  sarda  came  from  the  neighbour- 
hood of  a  city  of  that  name  in  Lydia,  and  from  the  environs  of  Babylon.  Among  the 
engraved  sards  which  exist  in  the  collection  of  antiques  in  the  Bibliotheqne  Royale  of 
Paris,  there  is  an  Apollo  remarkable  for  its  fine  colour  and  great  size.  When  the  stone 
forms  a  part  of  the  agate-onyx,  it  is  called  sardonyx.  For  further  details  upon  Gems,  and 
the  art  of  cutting  and  engraving  them,  see  LAPiDAav. 

GEOGNOSY,  means  a  knowledge  of  the  structure  of  the  earth :  Geology,  a  description 
of  the  same.  The  discussion  of  this  subject  does  not  come  within  the  province  of  this 
Dictionary. 

GERHARDT'S  ANHYDROUS  ACETIC  ACID.  Mix  perfectly  dry  fused  acetate 
of  potash  with  about  half  its  weight  of  chloride  of  benzoyle,  and  applying  a  gentle 
heat,  a  limpid  liquid  distils  over,  which  after  being  rectified  has  a  constant  boil- 
ing point  of  2-79°  Fahr.,  is  heavier  than  water,  with  which  it  does  not  mix  till  after 
it  has  been  agitated  with  it  for  some  time.     It  dissolves  at  once  in  hot  water,  forming 


B98 


GIN. 


•it 


a  hydrated  acetic  acid.      Its  composition  agrees  perfectly  with  the  atomic  numbers 
KuA  A  PTT>    Apeticl 

GERMAN  SILVER.     See  the  latter  end  of  the  article  Copper. 

GERMINATION;  (Eng.  and  Fr.;  Das  Keimen,  Germ.)  is  the  first  sprouting  of  a 
seed  after  it  is  sown,  or  when,  after  steeping,  it  is  spread  upon  the  malt  floor.     See  Beer. 

GIG  MACHINES,  are  rotatory  drums,  mounted  with  thistles  or  wire  teeth  for 
teazling  cloth.     See  Woollen  Manufacture. 

GILDING  [Dorure,  Fr. ;  Vergoldung,  Germ.) ;  is  the  art  of  coating  surfaces  with 
a  thin  film  of  gold.  For  a  full  discussion  of  this  subject,  see  Gold.  Mr.  Elkingttm, 
gilt  toy  maker,  obtained  a  patent,  in  June,  1836,  for  gilding  copper,  brass,  <fec.,  by 
means  of  potash  or  soda  combined  with  carbonic  acid,  and  with  a  solution  of  gold. 
Dissolve,  says  he,  5  oz.  troy  of  fine  gold  in  52  oz.  avoirdujjois  of  nitromuriatic  acid  of 
the  following  proportions;  viz.  21  oz.  of  pure  nitric  acid,  of  spec.  grav.  145,  17  oz. 
of  pure  muriatic  acid,  of  spec.  grav.  i'15;  with  14  oz.  of  distilled  water. 

The  gold  being  put  into  the  mixture  of  acids  and  water,  they  are  to  be  heated  in 
a  glass  or  other  convenient  vessel  till  the  gold  is  dissolved;  and  it  is  usual  to  continue 
the  application  of  heat  after  this  is  effected,  until  a  reddish  or  yellowish  vapour  ceases 
to  rise. 

The  clear  liquid  is  to  be  carefully  poured  off  from  any  sediment  which  generally 
appears  and  results  from  a  small  portion  of  silver,  which  is  generally  found  in  alloy  with 
gold.  The  clear  liquid  is  to  be  placed  in  a  suitable  vessel  of  stone;  pottery  ware  is 
preferred.  Add  to  the  solution  of  gold  4  gallons  of  distilled  water,  and  20  pounds  of  bicar- 
bonate of  potash  of  the  best  quality ;  let  the  whole  boil  moderately  for  iwo  hours,  tbt 
mixture  will  then  be  ready  for  use. 

The  articles  to  be  gilded  having  been  first  perfectly  cleaned  from  scale  or  grease,  they 
aie  tc  be  suspended  on  wires,  conveniently  for  a  workman  to  dip  them  in  the  liquid,  which 
is  kept  boiling.  The  time  required  for  gilding  any  particular  article  will  depend  on  cir- 
cumstances, partly  on  the  quantity  of  gold  remaining  in  the  liquid,  and  partly  on  the  size 
and  weight  of  the  article ;  but  a  little  practice  will  readily  give  sufficient  guidance  to  the 
workman. 

Supposing  the  articles  desired  to  be  gilded  be  brass  or  copper  buttons,  or  smaQ 
articles  for  gilt  toys,  or  ornaments  of  dress,  sr.;h  as  ear-rings  or  bracelets,  a  considerable 
number  of  which  may  be  strung  on  a  hoop,  -:r  bended  piece  of  copper  or  brass  wire,  and 
dipped  into  the  vessel  containing  the  boiling  liqi'Id  above  described,  and  moved  therein, 
the  requisite  gilding  will  be  generally  obtained  in  from  a  few  seconds  to  a  minute;  this 
is  when  the  liquid  is  in  the  condition  above  described,  and  depending  on  the  quality  of 
the  gilding  desired ;  but  if  the  liquid  has  been  used  some  time,  the  quantity  of  gold  will 
be  lessened,  which  will  vary  the  time  of  operating  to  produce  a  given  effect,  or  the 
color  required,  all  which  will  quickly  be  observed  by  the  workman;  and  by  noting 
the  appearance  of  the  articles  from  time  to  time,  he  will  know  when  the  desired  object 
is  obtained,  though  it  is  desirable  to  avoid  as  much  as  possible  taking  the  articles  out  of 
the  liquid. 

When  the  operation  is  completed,  the  workman  perfectly  washes  the  articles  so  gilded 
with  clean  water ;  they  may  then  be  submitted  to  the  usual  process  of  coloring. 

If  the  articles  be  cast  figures  of  animals,  or  otherwise  of  consideiable  weight,  compared 
with  the  articles  above  mentioned,  the  time  required  to  perform  the  process  will  be 
greater. 

In  case  it  is  desired  to  produce  what  is  called  a  dead  appearance,  it  may  be  performed 
by  several  processes :  the  one  usually  employed  is  to  dead  the  articles  in  the  process  of 
cleaning,  as  practised  by  brass-founders  and  other  trades;  it  is  produced  by  an  acid,  pre- 
pared for  that  purpose,  sold  by  the  makers  under  the  term  "  deading  aquafortis,"  which 
is  well  understood. 

It  may  also  be  produced  by  a  weak  solution  of  nitrate  of  mercury,  applied  to  the 
articles  previous  to  the  gilding  process,  as  is  practised  in  the  process  of  gilding  with 
mercury,  previous  to  spreading  the  amalgam,  but  generally  a  much  weaker  solution;  or 
the  articles  havins:  been  gilded  may  be  dipped  in  a  solution  of  nitrate  of  mercury,  and 
submitted  to  heat  to  expel  the  same,  as  is  practised  in  the  usual  process  of  gilding. 

It  is  desirable  to  remark,  that  much  of  the  beauty  of  the  result  depends  on  the  well 
cleaning  of  the  articles,  and  it  is  belter  to  clean  them  by  the  ordinary  processes,  and  at 
once  pass  them  into  the  liquid  to  be  gilded.     See  Gold,  towards  the  end. 

GIN,  or  Geneva,  from  Gemevre  (juniper),  is  a  kind  of  ardent  spirits  manufactured  in 
Holland,  and  hence  called  Hollands  gin  in  this  country,  to  distinguish  it  fr(»m  British 
gin.  The  materials  employed  in  the  distilleries  of  Schiedam,  are  two  parts  of  unmalled 
rye  from  Riga,  weighing  about  54  lbs.  per  bushel,  and  one  part  of  malted  bigg, 
weighing  about  37  lbs.  per  bushel.  The  mash  tun,  which  serves  also  as  the  fermenting 
tun,  has  a  capacity  of  nearly  700  gallons,  being  about  five  feet  ia  diameter  at  the  mouti^ 


GLASS. 


899 


rather  narrower  at  the  bottom,  and  4  J  feet  deep ;  the  stirring  apparatus  ia  an  oblonr 
rectangular  iron  grid  made  fast  to  the  end  of  a  wooden  pole.  About  a  barrel,  =  3$ 
^llons  of  water,  at  a  temperature  of  from  162°  to  168°  (the  former  heat  being  best  for 
the  most  highly  dried  rye),  are  put  into  the  mash  tun  for  every  1^  cwt.  of  meal  after 
which  the  malt  is  introduced  and  stirred,  and  lastly  the  rye  is  added  Powerful  agitation 
18  given  to  the  magma  till  it  becomes  quite  uniform ;  a  process  which  a  vigorous  work- 
man piques  himself  upon  executing  in  the  course  of  a  few  minutes.  The  mouth  of  the 
tun  IS  immediately  covered  over  with  canvas,  and  further  secured  by  a  close  wooden  lid 
to  confine  the  heat ;  it  is  left  in  this  state  for  two  hours.  The  contents  being  then  stirred 
up  once  more,  the  transparent  spent  wash  of  a  preceding  mashing  is  first  added,  and  next 
as  much  cold  water  as  will  reduce  the  temperature  of  the  whole  to  about  85°  F  The 
best  Flanders  yeast,  which  had  been  brought,  for  the  sake  of  carriage,  to  a  dout'hy  con- 
sistence  by  pressure,  is  now  introduced  to  the  amount  of  one  pound  for  every  100* gallons 
of  the  mashed  materials.  "^         ° 

The  gravity  of  the  fresh  wort  is  usually  from  33  to  38  lbs.  per  Dicas'  hydrometer  •  and 
the  fermentation  is  carried  on  from  48  to  60  hours,  at  the  end  of  which  time  the  atte'nua- 
tion  js  from  7  to  4  lbs.,  that  is,  the  specific  gravity  of  the  supernatant  wash  is  from  1-00^ 

to  roo4. 

The  distillers  are  induced,  by  the  scarcity  of  beer- barm  in  Holland,  to  skim  off  a  quan- 
tity of  the  yeast  from  the  fermenting  tuns,  and  to  sell  it  to  the  bakers,  whereby  they 
obstruct  materially  the  production  of  spirit,  though  they  probably  improve  its  quality  by 
preventing  its  impregnation  with  yeasty  particles ;  an  unpleasant  result  which  seldom  faii 
to  take  place  in  the  whiskey  distilleries  of  the  United  Kingdom. 

Ori  the  third  day  after  the  fermenting  tun  is  set,  the  wash  containing  the  grains  u 
transferred  to  the  still,  and  converted  into  low  wines.  To  every  100  gallons  of  this  liquor 
two  pounds  of  juniper  berries,  from  3  to  5  years  old,  being  added  along  with  about  one 
quarter  of  a  pound  of  salt,  the  whole  are  put  into  the  low  wine  still,  and  the  fine  Holland 
spirit  13  drawn  off  by  a  gentle  and  well-regulated  heat,  till  the  magma  becomes  exhausted  • 
the  first  and  the  last  products  being  mixed  together;  whereby  a  spirit,  2  to  3  per  cent' 
above  our  hydrometer  proof,  is  obtained,  possessing  the  peculiar  fine  aroma  of  gm  The 
quantity  of  spirit  varies  from  18  to  21  gallons  per  quarter  of  grain ;  this  large  product  beinff 
partly  due  to  the  employment  of  the  spent  wash  of  the  preceding  fermentation  •  an  addi 
tion  which  contributes  at  the  same  time  to  improve  the  flavour.  * 

For  the  above  instructive  details  of  the  manufacture  of  genuine  Hollands  I  am 
indebted  to  Robert  More,  Esq.,  formerly  of  Underwood,  distiller,  who,  after  studying  the 
art  at  Schiedam,  tried  to  introduce  that  spirit  into  general  consumption  in  this 
country,  but  found  the  palates  of  our  gin-drinkers  too  much  corrupted  to  relish  sc 
pure  a  beverage. 

GINGER  BEER.  Boil  05  gallons  of  river  water,  H  cwt.  of  the  best  loaf  suffar  and 
2  lbs.  of  the  best  race  ginger,  bruised,  half  an  hour ;  then  add  the  whites  of  10  eggs, 
beaten  to  a  froth  with  2  ounces  of  dissolved  isinglass.  Stir  it  wfll  in,  and  boil  '>0 
minutes  longer,  skimming  it  the  whole  time.  Then  add  the  thin  rinds  of  50  lemons 
boiling  them  lo  minutes  more.  Cut  28  lbs.  of  good  Malaga  raisins  in  half,  take  away  the 
stones  and  stalks,  and  put  them,  with  the  juice  of  the  lemon,  strained,  into  the  ho«^s- 
head-  Strain  the  hot  liquor  into  a  cooler,  and  when  it  has  stood  two  hours  and"*!* 
settled,  draw  it  off  the  lees,  clear,  and  put  it  into  the  cask ;  filter  the  thick  and  fill 
up  with  it.  Leave  the  bung  out,  and  when  at  the  proper  temperature  stir  3  quarts 
^/  *'"S.^^.^'*''^'  ale  yeast  well  into  it;  put  on  the  bung  lightly,  and  let  it  ferment  6  or  1 
days,  filling  up  with  liquor  as  it  ferments  over.  When  the  fermentation  has  ceased  pour 
in  6  quarts  of  French  brandy,  and  8  ounces  of  the  best  isinglass,  dissolved  in  a  gallon  of 
the  wine;  then  secure  the  bung  effectually,  and  paste  paper  over  it,  Ac  Keep  it  « 
years  in  a  cool  cellar,  then  bottle  it,  using  the  best  corks,  and  sealing  them  •  and 
when  it  is  4  years  old  commence  using  it.  ' 

GINNING,  is  the   name  of  the   operation   by  which   the   filaments   of  cotton   are 
separable  from  the  seeds.     See  Cottox  Manufactuee. 

GLANCE   COAL,  or  anthracite,  of  which    there   are    two   varieties,  the  slaty  and 
the  cotichmdaJ.     See  Anthuacitk  and  Pitcoal. 

GLASS  {Verre,  Fr. ;  Glas,  Germ.);  is  a  transparent  solid  formed  by  the  fusion  of 
siliceous  ami  alkaline  matter.  It  was  known  to  the  Phoenicians,  and  constituted  for 
a  long  time  an  exclusive  manufacture  of  that  people,  in  consequence  of  its  ingredients 
natron,  sand,  and  fuel,  abounding  upon  their  coasts.  It  is  probable  that  the  more 
ancient  Egyptians  were  unacquainted  with  glass,  for  we  find  no  mention  of  it  in  the 
writings  of  Moses.  But  according  to  Pliuy  and  Strabo,  the  glass  works  of  Sidon  and 
Alexandria  were  famous  in  their  times,  and  produced  beautiful  articles,  which  were 
cut,  engraved,  gilt,  and  stained  of  the  most  brilliant  colours,  in  imitation  of  precious 
stones.  The  Romans  employed  glass  for  various  purposes;  and  have  left  specimen* 
in  Herculaneura  of  window-glass,  which  must  have  been  blown  by  methods  analo^-ous  to 


^ 


GLASS. 


GLASS-MAKING. 


901 


the  modem.  The  Phoenician  processes  seem  to  have  been  learned  by  the  Crusaders,  and 
transferred  to  Venice  in  the  13th  century,  where  they  were  long  lield  secret,  and  formed 
a  lucrative  commercial  monopoly.  Soon  after  the  middle  of  the  17th  century,  Colbert 
enriched  France  with  the  blown  mirror  glass  manufacture. 

Chance  undoubtedly  had  a  principal  share  in  the  invention  of  this  curious  fabrication, 
but  there  were  circumstances  in  the  most  ancient  arts  likely  to  lead  to  it ;  such  as  the 
fusing  and  vitrifying  beats  required  for  the  formation  of  pottery,  and  for  the  extraction  of 
metals  from  their  ores.  Pliny  ascribes  the  origin  of  glass  to  the  following  accident.  A 
merchant  ship  lad^D  with  natron  being  driven  upon  the  coast  at  the  mouth  of  the  river 
Belus,  in  tempestuous  weather,  the  crew  were  compelled  to  cook  their  victuals  ashore, 
and  having  placed  lumps  of  the  natron  upon  the  sand,  as  supports  to  the  kettles,  found 
to  their  surprise  masses  of  transparent  stone  among  the  cinders.  The  sand  of  this  small 
stream  of  Galilee,  which  runs  from  the  foot  of  Mount  Carmel,  was  in  consequence  sup- 
poseil  to  possess  a  peculiar  virtue  for  making  glass,  and  continued  for  ages  to  be  sought 
after  and  exported  to  distant  countries  for  this  purpose. 

Agricola,  the  oldest  author  who  has  written  technically  upon  glass,  describes  furnaces 
and  processes  closely  resembling  those  employed  at  the  present  day.  Neri,  Kunckel, 
Henckel,  Pott,  Achard,  and  some  other  chemists,  have  since  then  composed  treatises 
upon  the  subject ;  but  Neri,  Bosc,  Antic,  Loysel,  and  Allut,  in  the  Encyclopedia 
Methodique,  are  the  best  of  the  older  authorities. 

The  wmdow-glass  manufacture  was  first  begun  in  England  in  1557,  in  Crutched  Friars, 
London ;  and  fine  articles  of  flint-glass  were  soon  afterwards  made  in  the  Savoy  House, 
Strand.  In  1635  the  art  received  a  great  improvement  from  Sir  Robert  Mansell,  by  the 
use  of  coal  fuel  instead  of  wood.  The  first  sheets  of  blown  glass  for  looking-glasses  and 
coach  windows  were  made  in  1673  at  Lambeth,  by  Venetian  artisans  employed  under  the 
patronage  of  the  Duke  of  Buckingham. 

The  casting  of  mirror-plates  was  commenced  in  France  about  the  year  1688,  by 
Abraham  Thevart ;  an  invention  which  gave  rise  soon  afterwards  to  the  establishment  of 
the  celebrated  works  of  St.  Gt)bain,  which  continued  for  nearly  a  century  the  sole  place 
where  this  highly-prized  object  of  luxury  was  well  made.  In  cheapness,  if  not  in  excel- 
lence, the  French  mirror-plate  has  been  for  gome  time  rivalled  by  the  English. 

The  analysis  of  modern  chemists,  which  will  be  detailed  in  the  course  of  this  article, 
and  the  light  thrown  upon  the  manufacture  of  glass  in  general  by  the  accurate  means 
now  possessed  of  purifying  its  several  ingredients,  would  have  brought  the  art  long  since 
to  the  highest  state  of  perfection  in  this  country,  but  for  the  vexatious  interference  and 
obstructions  of  our  excise  laws. 

The  researclies  of  Berzelius  having  removed  all  doubts  concerning  the  acia  character 
of  silica,  the  general  composition  of  glass  presents  now  no  difficulty  of  conception. 
This  substance  consists  of  one  or  more  salts,  whicli  are  silicates  with  bases  of  potash, 
Hoda,  lime,  oxide  of  iron,  alumina,  or  oxide  of  lead ;  in  any  of  which  compounds  we  can 
substitute  one  of  these  bases  for  another,  provided  that  one  alkaline  base  be  left.  Silica 
in  its  turn  may  be  replaced  by  the  boracic  acid,  without  causing  the  glass  to  lose  ita 
principal  characters. 

Under  the  title  glass  are  therefore  comprehended  various  substances  fusible  at  a  high 
temperature,  solid  at  ordinary  temperatures,  brilliant,  generally  more  or  less  transparent, 
and  always  brittle.     The  following  chemical  distribution  of  glasses  lias  been  proposed. 

1.  Soluble  glass;  a  simple  silicate  of  potash  or  soda;  or  both  of  these  alkalis. 

2.  Bohemian  or  crown  glass  ;  silicate  of  potash  and  lime. 

3.  Common  window  and  mirror  glass  •.  silicate  of  soda  and  lime ;  sometimes  also  of  potash. 

4.  Bottle  glass ;  silicate  of  soda,  lime,  Alumina  and  iron. 

5.  Ordinary  crystal  glass ;  silicate  of  potash  and  lead. 

6.  Flint  glass ;  silicate  of  potash  and  lead ;  richer  in  lead  than  the  preceding. 

7.  Strass ;  silicate  of  potash  and  lead ;  still  richer  in  lead. 

8.  Enamel ;  silicate  and  stannate  or  antimoniate  of  potash  or  soda,  and  lead 

The  glasses  which  contain  several  bases  are  liable  to  suffer  different  changes  when 
they  are  n:elted  or  cooled  slowly.  The  silica  is  divided  among  these  bases,  forming  new 
compounds  in  definite  proportions,  which  by  crystallizing  separate  from  each  other,  so 
that  the  general  mixture  of  the  ingredients  which  constitute  the  glass  is  destroyed.  It 
becomes  then  very  hard,  fibrous,  opaque,  much  less  fusible,  a  better  conductor  of  electri- 
city and  of  heat ;  forming  what  Reaumur  styled  devitrijied  glass ;  and  what  is  called  after 
him  Reaumur's  porcelain. 

This  altered  glass  can  always  be  produced  in  a  more  or  less  perfect  »«tate,  by  melting 
the  glass  and  allowing  it  to  cool  very  slowly ;  or  merely  by  heating  it  to  the  softening 
pitch,  and  keeping  it  at  this  heat  for  some  time.  The  process  succeeds  best  with  the 
most  complex  vitreous  compounds,  such  as  bottle  glass ;  next  with  ordinary  window 
glass ;  and  lastly  with  glass  of  potash  and  lead. 

This  property  ought  to  be  kept  constantly  in  view  in  manufacturing  glass.     It  shows 


why  m  making  bottles  we  should  fashion  them  as  quickly  as  possible  with  the  aid  of  a 
mould  and  reheat  them  as  seldom  as  may  be  absolutely  necessary.  If  it  be  often  heated 
and  cooled,  the  glass  loses  its  ductility,  becomes  refractory,  and  exhibits  a  multitude  of 
stony  granulations  throughout  its  substance.  When  coarse  glass  is  worked  at  the  enamel- 
ler  8  lamp,  it  is  apt  to  change  its  nature  in  the  same  way,  if  the  workman  be  not  quick  and 
expert  at  his  business. 

From  these  facts  we  perceive  the  importance  of  making  a  careful  choice  of  the  glass 
mtended  to  be  worked  in  considerable  masses,  such  as  the  large  object  glasses  of  tele- 
scopes; as  their  annealing  requires  a  very  slow  process  of  refrigeration,  which  is  apt  to 
cause  devitrified  specks  and  clouds.  For  such  purposes,  therefore,  no  other  species  of 
glass  18  well  adapted  except  that  with  basis  of  potash  and  lead ;  or  that  with  basis  of 
potash  and  lime.  These  two  form  the  best  flint  glass,  and  crown  glass ;  and  they  «:hould 
be  exclusively  employed  for  the  construction  of  the  object  glasses  of  achromatic  telescopes. 
Crystal  glass  is  rapidly  corroded  by  the  sulphate  of  ammonia  at  a  heat  of  600°  Fahr. 

The  following  is  an  account  of  the  exports  of  British  manufacture : 


Flint  glass cwts. 

Window  glass cwts. 

Bottles,  green  or  common    -  cwts. 

Plate  glass value 


Quantities. 


1851. 


23,870 

15,517 

296,065 


1852. 


25,755 

16,460 

825,804 


Declared  Value. 


1851. 


1852. 


£106,500 

20,077 

162,843 

18,335 


£110,519 

22,234 

172,880 

20,929 


Imports  and  exports  of  Glass  of  Foreign  and  Colonial  produce  in  the  years  endino- 

respectively  5th  January,  1851  and  1852:—  ^  o 

Window  glass,  not  exceeding  \  of  an  inch  thick,  and  shades  and  cylinders :  imports 

?l'^l?  '"'^i^;  ol"il  ^^'^^^  ^'^^•'  ^*P°^^^'  ^^'604  c^*s.  and  2,059  cwta;  duty  on  imports! 
1,656/.  and  1,877/.  r    ~» 

All  glass  exceeding  »  of  an  inch  thick,  all  silvered  or  polished  glass  of  whatever  thick- 
ness: imports,  122,394  sq.  ft.  and  173,935  sq.  ft.;  exports,  32,388  sq.  ft  and  36.550 
sq.  ft. ;  duty  received,  1,845/.  and  2,841/.  '  i  »     " 

^..^^'^')*^fJo*.n^lf  ^  ^"^^  ^^^''^^}.  ^''*^^^')  "^*  ^'^*'  engraved,  or  otherwise  ornamented: 
lof/'Tnd  108/  '^^^        '  ^''^'■*''  '^^'^^^  ^^''  ^""^  ^^'^^^  ^^'- '  ^"*y  ^^<^^'^^ed, 

11  ^^^  ^J"lol'n,^^^?u' ^'°^  coloured  glass,  and  fancy  ornamental  glass:  imports,  880,981 
and4''454/      '  '  ^^^'^''  ^^^'^^^  ^^''  ^"^  ^^^'^^^  lbs. ;  duty  received,  5,542/. 

GLASS-MAKING,  general  principles  of.  Glass  may  be  defined  in  technical  phrase- 
ology, to  be  a  transparent  homogeneous  compound  formed  by  the  fusion  of  silit^  with 
oxides  of  the  alkaline  earthy,  or  common  metals.  It  is  usually  colourless,  and  then 
resembles  rock  crystal,  but  is  occasionally  stained  by  accident  or  design  with  coloured 
metallic  oxides.  At  common  temperatures  it  is  hard  and  brittle,  in  thick  pieces  •  in  thin 
plaesor  threads,  flexible  and  elastic;  sonorous  when  struck;  fracture  conchoidal  and 
of  that  peculiar  lustre  called  vitreous;  at  a  red  heat,  becoming  soft,  ductile  and  plastia 
Besides  glass  properly  so  called,  other  bodies  are  capable  of  entlring  into  vitreous  fusio^ 
as  phosphoric  acid  boracic  acid,  arsenic  acid,  as  also  certain  metaUic  oxides,  as  of  lead 
an.  antimony,  and  several  chlorides;  some  of  which  are  denominated  glasses  Impure 
and  opaque  v. triform  masses  are  called  slags;  such  are  the  production Sf  blast  iron  fur! 
naces  and  many  metallurgic  operations. 

Silica,  formerly  styled  the  earth  of  flints,  which  constitutes  the  basis  of  all  commercial 
g^ass,  •«  'nfusib^  by  itself  in  the  strongest  fire  of  our  furnaces;  but  its  vitreous  fusLnts 
cas  y  eff-ected  by  a  competent  addition  of  potash  or  soda,  either  alone  or  mixed  with  lime 
>Lo«  nTfr.  if  fr-  '  "i  Tx!"^  ^u  ^^•g^r^^d  ^  belonging  to  the  class  of  acids,  com- 
be eu  J  L'l'^^  f"T  ""f-  *^'''.  ^''.'''  ^?^^,  '^^'''^  compounds ;  and  hence  glasL  may 
be  Mewed  as  a  silicate  of  certain  oxides,  m  which  the  acid  and  the  bases  exist  in  equiva- 

ZJr\T    T"-  .^T  ^^^«^P'•«P«[t.«°^.  or  the  quantities  of  the  bases  which  silica 

ZVnZJ'Vr'  «^*"'-fV,''\''\*''^  "'^^•'°-  P^^"*'  "^^*^^l3^  ascertained,  we  micrht  readily 
determine  beforehand  the  best  proportions  of  materials  for  the  glass  manufacture.     But 

nf  .^  nrt.  ^''7,,^'"^.^'^^  «^!«'  «"^  as  it  is,  moreover,  not  improbable  that  the  capacity 
of  saturation  of^he  silica  varies  with  the  temperature,  and  that  the  properties  of  gla4 
also  vary  with  the  bases,  we  must,  in  the  present  state  of  our  knowlldge.  regulate  the 
proportions  rather  by  practice  than  by  theory,  though  the  latter  may  throw  an  indirect 
ight  upon  the  subject.  For  example,  a  good  colourless  glass  has  been  found  by  analysU 
to  consist  of  72  parts  of  silica,  13  parts  of  potash,  and  10  parts  of  lime,  in  95  parts.  If 
we  reduce  these  numbers  to  the  equivalent  ratios,  we  shall  have  the  followii^  results- 
taking  the  atomic  weights  as  given  by  Berzelius.  * 


902 


GLASS-MAKING. 


GLASS-MAKING. 


M» 


1  atom  potash  =    590 

14.67 

1           lime            356 

8-84  > 

3           silica         1722 

42-79  S 

2           silica         1155 

28-70  ) 

is  soda  ;  for  potash  does  not  assimilate  well  with  the  calcareous 


571-49 


3823 


95-00 


This  glass  would  therefore  have  been  probably  better  compounded  with  the  just  atomic 
proportions,  to  which  it  nearly  approaches,  viz.  71*49  silica,  14*67  potash,  and  8*84  lime, 
instead  of  those  given  above  as  its  actual  constituents. 

The  proportions  in  which  silica  unites  with  the  alkaline  and  other  oxydes  are  mo- 
dified by  the  temperature  as  above  stated ;  the  lower  the  heat,  the  less  silica  will  enter 
into  the  glass,  and  the  more  of  the  base  will  in  general  be  required.  If  a  glass  which 
contains  an  excess  of  alkali  be  exposed  to  a  much  higher  temperature  than  thai  of  ils 
formation,  a  portion  of  the  base  will  be  set  free  to  act  upon  the  materials  of  the  earthen 
pot,  or  to  be  dissipated  in  fumes,  until  such  a  silicate  remains  as  to  constitute  a  per- 
manent glass  corresponding  to  that  temperature.  Hence  the  same  mixture  of  vitrifiable 
materials  will  yield  very  different  results,  according  to  the  heats  in  which  it  is  fused  and 
worked  in  the  glass-house ;  and  therefore  the  composition  should  always  be  referrible  to 
the  going  of  the  furnace.  When  a  species  of  glass  which  at  a  high  temperature  formed 
a  transparent  combination  with  a  considerable  quantity  of  lime,  is  kept  for  some  time  in 
fusion  at  a  lower  temperature,  a  portion  of  the  lime  unites  with  the  silica  into  another 
combination  of  a  semi-vitreous  or  even  of  a  stony  aspect,  so  as  to  spoil  the  transparency 
of  the  glass  altogether.  There  is  probably  a  supersilicate  and  a  sub-silicate  formed  in 
such  cases  ;  the  latter  being  much  the  more  fusible  of  the  two  compounds.  The  Reau- 
mur's porcelain  produced  by  exposing  bottle  glass  to  a  red  heat  for  24  hours,  is  an  exam- 
ple of  this  species  of  vitreous  change,  in  which  new  affinities  are  exercised  at  a  lower 
temperature.  An  excess  of  silica,  caused  by  the  volatilization  of  alkaline  matter  with 
too  strong  firing,  will  bring  on  similar  appearances. 

The  specific  gravity  of  glass  varies  from  2-3  to  3'6.  That  of  least  specific  gravity  con- 
sists of  merely  silica  and  potash  fused  together ;  that  with  lime  is  somewhat  denser,  and 
with  oxyde  of  lead  denser  still.  Plate  glass  made  from  silica,  soda,  and  lime,  has  a  speci- 
fic gravity  which  varies  from  2*50  to  2*6 ;  crystal  or  flint  glass  from  3*0  to  3*6. 

The  power  of  glass  to  resist  the  action  of  water,  alkalis,  acids,  air,  and  light,  is  in 
general  the  greater,  the  higher  the  temperature  employed  in  its  manufacture,  the  smallei 
the  proportion  of  its  fluxes,  and  the  more  exact  the  equivalent  ratios  of  its  constituents. 
When  glass  contains  too  much  alkali,  it  is  partially  soluble  in  water.  Most  crystal  glass 
is  aflected  by  having  water  boiled  in  it  for  a  considerable  time ;  but  crown  glass  being 
poorer  in  alkali,  and  containing  no  lead,  resists  that  action  much  longer,  and  is  therefore 
better  adapted  to  chemical  operations.  The  affinity  of  glass  for  water,  or  its  hygrometric 
attraction,  is  also  proportional  to  the  quantity  of  alkali  which  it  contains.  In  general 
also  potash  glass  is  more  apt  to  become  damp  than  soda  glass,  agreeably  to  the  respective 
hygrometric  properties  of  these  two  alkalis,  and  also  to  the  smaller  proportion  of  soda 
than  of  potash  requisite  to  form  glass. 

Air  and  light  operate  upon  glass  probably  by  their  oxydizing  property.  Bluish  or 
greenish  colored  glasses  become  by  exposure  colorless,  in  consequence  undoubt- 
edly of  the  peroxydizement  of  the  iron,  to  whose  protoxyde  they  owe  their  tint; 
other  glasses  become  purple  red  from  the  peroxydizement  of  the  manganese.  The  glasses 
which  contain  lead,  suffer  another  kind  of  change  in  the  air,  if  sulphureted  hydrogen 
be  present ;  the  oxyde  of  lead  is  converted  into  a  sulphuret,  with  the  efl'ect  of  rendering 
the  surface  of  the  glass  opaque  and  iridescent.  The  more  lead  is  in  the  glass,  the 
quicker  does  this  iridescence  supervene.  By  boiling  concentrated  sulphuric  acid  in  a 
glass  vessel,  or  upon  glass,  we  can  ascertain  its  power  of  resisting  ordinary  men- 
strua. Good  glass  will  remain  smooth  and  transparent ;  bad  glass  will  become  rough 
and  dim. 

The  brittleness  of  unannealed  glass  by  change  of  temperature  is  sometimes  very 
great.  I  have  known  a  thick  vessel  to  fly  by  vicissitudes  of  the  atmosphere  alone.  This 
defect  may  be  corrected  by  slowly  heating  the  vessel  in  salt  water  or  oil  to  the  highest 
pitch  consistent  with  the  nature  of  these  liquids,  and  letting  it  cool  very  slowly.  Within 
the  limits  of  that  range  of  heat,  it  will,  in  consequence  of  this  treatment,  bear  alternations 
of  temperature  without  cracking  as  before. 

It  has  been  said  that  glass  made  from  silica  and  alkalis  alone  will  not  resist  the  action 
of  water  but  that  the  addition  of  a  little  lime  is  necessary  for  this  effect.  In  general 
100  parts  of  quartzose  sand  require  33  parts  of  dry  carbonate  of  soda  for  their  vitrifica- 
tion, and  45  parts  of  dry  carbonate  of  potash.  But  to  make  unchangeable  alkaline  glass, 
especially  with  potash,  a  smaller  quantity  of  this  than  the  above  should  be  used,  with  a 
very  violent  heat.  A  small  proportion  of  lime  increases  the  density,  hardness,  and  lustre 
of  glass ;  and  it  aids  in  decomposing  the  alkaline  sulphates  and  muriates  always  present 
in  the  pearlash  of  commerce.  From  7  to  20  parts  of  dry  slaked  lime  have  been  added 
Tx  100  of  silica,  with  advantge,  it  is  said,  ia  some  German  glass  manufactories,  where 


the  alkaline  matter 
earth. 

In  many  glass  works  on  the  Continent,  sulphate  of  soda  is  the  form  ander  which  alkaline 
matter  is  introduced  into  glass.  This  salt  requires  the  addition  of  8  per  cent,  of  char- 
coal  to  decompose  and  dissipate  its  acid;  a  result  which  takes  place  at  a  high  heat,  with- 
out the  addition  of  any  lime.  88  pounds  of  quartz-sand,  44  pounds  of  dry  glauber  salt, 
and  3  pounds  of  charcoal,  properly  mixed  and  fused,  afford  a  limpid,  fluent,  and  workable 
g  ass ;  with  the  addition  of  17  pounds  of  lime,  these  materials  fuse  more  readily  into  a 
plastic  mass.  If  less  carbon  be  added,  the  fusion  becomes  more  tedious.  The  two  follow- 
ing formulae  afford  good  glauber  salt  glass. 

L  2. 

Sand       .... 

Calcined  sulphate  of  soda 

Lime      .... 

Charcoal         -        .        -  -      ^  y,^  *,, 

The  first  mixture  has  been  proved  in  the  looking-glass  manufactory  of  Ncthaus  near 
Vienna,  and  the  second  by  the  experiments  of  Kirn.  The  fusion  of  the  first  requires 
1^,  of  the  second  21  hours.  The  bluish  green  tinge  which  these  otherwise  beautiful  and 
brilliant  glasses  possess,  is  not  removeable  by  the  ordinary  means,  such  as  mano-anese  or 
arsenic  which  decolor  alkaline  glass.  When  the  sulphate  of  soda  and  charcoaf  are  used 
in  smaller  proportions,  the  glass  becomes  more  colorless.  The  tinge  is  no  doubt  owing 
to  the  sulphur  combining  with  the  oxyde  of  sodium,  in  some  such  way  as  in  the  pismenl 
ultramarine.  y  s    ^"^ 

By  a  proper  addition  of  galena  (the  native  sulphuret  of  lead),  to  glauber  salt  and  quarts 
sand,  without  charcoal,  it  is  said  a  tolerably  good  crystal  glass  may  be  formed.  The 
sulphuric  acid  of  the  salt  is  probably  converted  by  the  reaction  of  the  sulphuret  of  lead 
into  sulphurous  acid  gas,  which  is  disengaged. 

One  atom  of  sulphuret  of  lead  =  1495-67,  is  requisite  to  decompose  3  atoms  of  sulphate 
oi  soda  =  2676.  It  is  stated,  on  good  authority,  that  a  j?ood  colorless  glass  may  be  ob- 
tamed  by  using  glauber  salt  without  charcoal,  as  by  the  following  formula. 

Quartz-sand    -        -        -        -        100  pounds 

Calcined  glauber  salt        -        -  24 

Lime 20 

Cullet  of  soda  glass  -        -  12 

The  melting  heat  must  be  continued  for  26|  hours.  A  small  quantity  of  the  sand  is 
reserved  to  be  thrown  in  towards  the  conclusion  of  the  process,  in  order  to  facilitate  the 
expulsion  of  air  bubbles.  The  above  mixture  will  bear  to  be  blanched  by  the  addition 
of  raansanese  and  arsenic.  The  decomposition  of  the  salt  is  in  this  case  effected  by  the 
hme,  with  wi>!ch  the  sulphuric  acid  first  combines,  is  then  converted  into  sulphurous  acid, 
and  dissipated.  Glass  made  m  this  way  was  found  by  analysis  to  consist  of  79  parts  of 
saica,  12  lime,  and  9-6  soda,  without  any  trace  of  gypsum  or  sulphuric  acid 

Glauber  salt  is  partially  volatilized  by  the  heat  of  the  furnace,  and  acts  upon  the  arch 
of  the  oven  and  the  tops  of  the  pots.  This  is  best  prevented  by  introducing  at  first  into 
the  pots  the  whole  of  the  salt  mixed  with  the  charcoal,  the  lime,  and  one  fourth  part  of 
the  sand ;  fusing  this  mixture  at  a  moderate  heat,  and  adding  gradually  afterwards  the 
remainder  of  the  sand,  mcreasing  the  temperature  at  the  same  time.  If  we  put  in  the 
whole  ingredients  together,  as  is  done  with  potash  glass,  the  sand  and  lime  soon  fall  to 
the  bottom,  while  the  salt  rises  to  the  surface,  and  the  combination  becomes  difficult  and 

UucQ  ufllJ  • 

Sulphate  of  potash  acts  in  the  same  way  as  sulphate  of  soda 

Muriate  of  soda  also,  according  to  Kirn,  may  be  used  as  a  glass  flux  with  advantage. 
H^Z^mI  /";^^^^^,P^°P«rt.ons  are  4  parts  of  potash,  2  of  common  salt,  and  3  of  l^e. 
agreeably  to  the  following  compositions : * 

L  2. 

Quartz-sand        ... 
Calcined  carbonate  of  potash 
Common  salt       •        •        . 
Lime  .       •       '.       . 

For  No.  L,  the  melting  heat  must  be  10  hours,  whicli'turns  out  a  very  pure,  '^iTd.  good 
gla^s;  for  No  2.,  23  hours  of  the  furnace  are  required.  Instead  of  the  potash,  glkuber 
salt  may  be  substituted ;  the  proportions  being  then  19-1  glauber  salt,  9-5  muriate  of  soda. 
14-3  lime,  7 51  sand,  and  1-3  charcoal  * 

The  oxide  of  lead  is  an  essential  constituent  of  the  denser  glasses,  and  may  be  regarded 
as  replacing  the  lime,  so  as  to  form  with  the  quartz-sand  a  silicate  of  lead.  It  assimilates 
best  with  purifaed  pearl  ash,  on  account  of  the  freedom  of  this  alkali  from  iron  which  ia 
present  m  most  sodas.  '  " 


904 


GLAS». 


GLASS-MAKING. 


905 


Its  atomic  constitution  may  be  represented  as  follows : — 


I 


I 


i« 


Silicic  acid 

Oxide  of  lead     .    -    -     -    • 

Potash 

Oxides  of  iron  and  manglmese 

5  atoms    =    28'77* 
1                =     1394-5 
1                =      690-0 

Gompatation. 

Analysis. 

59-19 
28-68 
12-13 

59-20 

28.20 

9-00 

1-40 

4861-6 

100-00 

100-00 

The  above  analysis  by  Berthier  relates  to  a  specimen  of  the  best  English  crystal  glass, 
perfectly  colourless  and  free  from  air-bubbles.     This  kind  of  glass  may  however  take 
several  different  proportions  of  potash  and  silica  to  the  oxide  of  lead. 

The  composition  of  mirror-plate,  as  made  on  the  Continent,  is  as  follows  : — 

White  quartz- sand  -----  300  pounds 

Dry  carbonate  of  soda        -  -  -  -  -  100 

Lime  slaked  in  the  air        -  -  -  -  -  48 

Gullet,  or  old  glass  -  -  -  •  •  800 

The  manganese  should  not  exceed  one-half  per  cent,  of  the  weight  of  soda. 
Optical  glass  requires  to  be  made  with  very  peculiar  care.    It  is  of  two  different  kinds; 
namely,  crown  glass  a.ndjlint  glass.    The  latter  contains  a  considerable  proportion  of  lead, 
in  order  to  give  it  an  increased  dispersive  power  upon  the  rays  of  light,  in  proportion  to 
its  mean  refractive  power. 

Optical  crown  glass  should  be  perfectly  limpid,  and  have  so  little  colour,  that  a  pretty 
thick  piece  of  it  may  give  no  appreciable  tinge  to  the  rays  of  light.    It  should  be  exempt 
from  striae  or  veins  as  well  as  air-bubbles,  and  have  not  the  slightest  degree  of  milkiness. 
It  should  moreover  preserve  these  qualities  when  worked  in  considerable  quantities. 
Potash  is  preferable  to  soda  for  making  optical  crown  glass,  because  the  latter  alkali  is 
apt  to  make  a  glass  which  devitrifies  and  becomes  opalescent,  by  long  exposure  to  heat 
in  the  annealing  process.     A  simple  potash  silicate  would  be  free  from  this  defect,  but 
it  would  be  too  attractive  of  moisture,  and  apt  to  decompose  eventually  by  the  humidity 
of  the  atmosphere.     It  should  therefore  contain  a  small  quantity  of  lime,  and  as  little 
potash  as  suffices  for  making  a  perfect  glass  at  a  pretty  high  temperature.    It  is  probably 
owing  to  the  high  heats  used  in  the  English  crown  glass  works,  and  the  moderate  quantity 
of  alkali  (soda)  which  is  employed,  that  our  crown  glass  has  been  found  to  answer  so  well 
for  optical  purposes. 

The  following  recipe  for  crown  glass  is  excellent : — 

5  atoms  of  silica  (2^  ?)  -  -  -  -     80 

1  carbonate  of  soda      -  -  -  -  -     54 

5  silica  -  -  -  -  -  -     80 

1  carbonate  of  lime      -  -  -  -  -     50 

1  atom  of  carbonate  of  baryta  -  -  -     98 

5  atoms  of  silica         -  -  -  -  -    80 

Silicates  of  lime  and  baryta  per  se,  or  even  combmed,  are  very  refractory ;  but  they 
vitrify  well  along  with  a  third  silicate,  such  as  that  of  soda,  or  potash. 

Practical  Details  of  the  Manufacture  of  Glass, 

The  Venetians  were  the  first  in  modern  times  who  attained  to  any  degree  of  excellence 
in  the  art  of  working  glass,  but  the  French  became  eventually  so  zealous  of  rivalling 
them,  particularly  in  the  construction  of  mirrors,  that  a  decree  was  issued  by  the  court 
of  France,  declaring  not  only  that  the  manufacture  of  glass  should  not  derogate  from  the 
dignity  of  a  nobleman,  but  that  nobles  alone  should  be  masters  of  glass-works.  Within 
the  last  30  or  forty  years,  Great  Britain  has  made  rapid  advances  in  this  important  art, 
and  at  the  present  day  her  pre-eminence  in  every  department  hardly  admits  of  dispute. 

There  are  five  different  species  of  glass,  each  requiring  a  peculiar  mode  of  fabrication, 
and  peculiar  materials  :  1.  The  coarsest  and  simplest  form  of  this  manufacture  is  bottle 
glass.  2.  Next  to  it  in  cheapness  of  material  may  be  ranked  broad  or  spread  window 
glass.  An  improved  article  of  this  kind  is  now  made  near  Birmingham,  under  the  name 
of  British  or  German  plate.  3.  Crown  glass  comes  next,  or  window  glass,  formed  in 
large  circular  plates  or  discs.  This  glass  is  peculiar  to  Great  Britain.  4.  Flint  glasf, 
crystal  glass,  or  glass  of  lead.     5.  Plate  or  fine  mirror  glass. 

The  materials  of  every  kind  of  glass  are  vitrified  in  pots  made  of  a  pure  refractory 
day  ;  the  best  kind  of  which  is  a  species  of  shale  or  slate  clay  dug  out  of  the  coal-form- 
ation near  Stourbridge.  It  contains  hardly  any  lime  or  iron,  and  consists  of  silica 
and  alumina  in  nearly  equal  proportions.  The  masses  are  carefully  picked,  brushed; 
and  ground  under  edge  iron  wheels  of  considerable  weight,  and  siAed  through  sieves 


having  20  meshes  in  the  square  inch.  This  powder  is  moistened  with  water  (best  hot), 
and  kneaded  by  the  feet  or  a  loam-mill  into  a  uniform  smooth  paste.  A  large  body  of 
this  (lough  should  be  made  up  at  a  time,  and  laid  by  in  a  damp  cellar  to  ripen.  Pre- 
viously to  working  it  into  shapes,  it  should  be  mixed  with  about  a  fourth  of  its  weight  of 
cement  of  old  pots,  ground  to  powder.  This  mixture  is  sufficiently  plastic,  and  being 
less  contractile  by  heat,  forms  more  solid  and  durable  vessels.  Glass-house  pots  have 
the  figure  of  a  truncated  cone,  with  the  narrow  end  undermost ;  those  for  bottle  and 
window-glass  being  open  at  top,  about  30  inches  diameter  at  bottom,  40  inches  at  the 
mouth,  and  40  inches  deep;  but  the  flint-glass  pots  are  covered  in  at  top  with  a  dome-cap, 
having  a  mouth  at  the  side,  by  which  the  materials  are  introduced,  and  the  glass  is  ex- 
tracted. Bottle  and  crown-house  pots  are  from  3  to  4  inches  thick ;  those  for  flint-houses 
are  an  inch  thinner,  and  of  proportionally  smaller  capacity. 

The  well-mixed  and  kneaded  dough  is  first  worked  upon  a  board  intc  t  cake  for 
the  bottom ;  over  this  the  sides  are  raised,  by  laying  on  its  edges  rolls  of  clay  above 
each  other  with  much  manual  labor,  and  careful  condensation.  The  clay  is  made 
into  lumps,  is  equalized,  and  slapped  much  in  the  same  way  as  for  making 
Pottery.  The  pots  thus  fashioned  must  be  dried  very  prudently,  first  in  the 
atmospheric  temperature,  and  finally  in  a  stove  floor,  which  usually  borrows  its  heat 
directly  from  the  glass-house.  Before  setting  the  pots  in  the  furnace,  they  are  annealed 
during  4  or  5  days,  at  a  red  heat,  in  a  small  reverberalory  vault,  made  on  purpose. 
When  completely  annealed,  they  are  transferred  with  the  utmost  expedition  into  their 
seat  in  the  fire,  by  means  of  powerful  tongs  supported  on  the  axle  of  an  iron-wheel 
carriage  frame,  and  terminating  in  a  long  lever  for  raising  them  and  swinging  them 
round.  The  pot-setting  is  a  desperate  service,  and  when  unskilfully  conducted  without 
due  mechanical  aids,  is  the  forlorn  hope  of  the  glass-founder. — Quceque  ipse  miserrima 
vidi.  The  celebrated  chemist.  Dr.  Irvine,  caught  his  last  illness  by  assisting  imprudently 
at  this  formidable  operation.  The  working  breast  of  the  hot  furnace  must  be  laid  bare 
so  as  to  open  a  breach  for  the  extraction  of  the  faulty  pot,  and  the  insertion  of  the  fresh 
one,  both  in  a  stale  of  bright  incandescence.  It  is  frightful  to  witness  the  eyes  an^ 
fuming  visages  of  the  workmen,  with  the  blackening  and  smoking  of  their  scorched  wool- 
len clothes,  exposed  so  long  to  the  direct  radiations  of  the  flame.  A  light  mask  and  sack 
dress  coated  with  tinfoil,  would  protect  both  their  faces  and  persons  from  any  annoyance, 
at  a  very  cheap  rate. 

The  glass-houses  are  usually  built  in  the  form  of  a  cone,  from  60  to  100  feet  high, 
and  from  50  to  80  feet  in  diameter  at  the  base.  The  furnace  is  constructed  in  the  centre 
of  the  area,  above  an  arched  or  groined  gallery  which  extends  across  the  whole  space,  and 
terminates  without  the  walls,  in  large  folding  doors.  This  cavern  must  be  sufficiently  high 
to  allow  laborers  to  wheel  out  the  cinders  in  their  barrows.  The  middle  of  the  vaulted 
top  is  left  open  in  the  building,  and  is  covered  over  with  the  grate-bars  of  the  furnace. 

1.  Bottle  glass. — The  bottle-house  and  its  furnace  resemble  nearly  yig.  505.  The  fur- 
nace is  usually  an  oblong  square  chamber,  built  of  large  fire-bricks,  and  arched  over  with 
fire-stone,  a  silicious  grit  of  excellent  quality  extracted  from  the  coal  measures  of  New- 
castle. This  furnace  stands  in  the  middle  of  the  area;  and  has  its  base  divided  into  three 
compartments.  The  central  space  is  occupied  by  the  grate-bars ;  and  on  either  side  is 
the  platform  or  fire-brick  siege  (seat),  raised  about  12  inches  above  the  level  of  the  ribs 
upon  which  the  pots  rest.     Each  siege  is  about  3  feet  broad. 

In  the  sides  of  the  furnace,  semi-circular  holes  of  about  a  foot  diameter  are  left  oppo- 
site to,  and  a  little  above  the  top  of.  each  pot,  called  working  holes,  by  which  the  work- 
men shovel  in  the  materials,  and  take  out  the  plastic  glass.  At  each  angle  of  the  furnace 
there  is  likewise  a  hole  of  about  the  same  size,  which  communicates  with  the  calcining 
furnace  of  a  cylindrical  form,  dome-shaped  at  top.  The  flame  that  escapes  from  the  found- 
ing or  pot-furnace  is  thus  economically  brought  to  reverberate  on  the  raw  materials  of  the 
bol tie-glass,  so  as  to  dissipate  their  carbonaceous  or  volatile  impurities,  and  convert  them 
into  a  frit.  A  bottle-house  has  generally  eight  other  furnaces  or  fire-arches ;  of  which 
six  are  used  for  annealing  the  bottles  after  they  are  blown,  and  two  for  annealing  the 
pots,  before  setting  them  in  the  furnace. 

The  laws  of  this  country  till  lately  prohibited  the  use  for  makmg  common  bottled  of 
any  fine  materials.  Nothing  but  the  common  river  sand,  and  soap-boilers'  waste,  was 
allowed.  About  3  parts  of  waste,  consisting  of  the  insoluble  residuum  of  kelp,  mixed 
with  lime  and  a  little  saline  substance,  were  used  for  1  part  of  sand.  This  waste  was  first 
of  all  calcined  in  two  of  the  fire  arches  or  reverberatories  reserved  for  that  purpose,  called 
the  coarse  arches,  where  it  was  kept  at  a  red  heat,  with  occasional  stirring,  from  24  to  30 
hours,  being  the  period  of  a  journey  or  joumce,  in  which  the  materials  could  be  melted 
and  worked  into  bottles.  The  roasted  soap-waste  was  then  withdrawn,  under  the  name 
of  ashes,  from  its  arch,  coarsely  ground,  and  mixed  with  its  proper  proportion  of  sand. 
This  mixture  was  now  put  into  the  fine  arch,  and  calcined  during  the  working  jour- 
ney,  which  extended  to  10  or  12  hours.     Whenever  the  pots  were  worked  out,  tnat  frit 


M 


i| 


906 


GLASS-MAKING. 


was  immediately  transferred  into  them  in  its  ignited  state,  and  the  founding  process 
proceed*  d  with  such  despatch  that  this  first  charge  of  materials  was  completely  melted 
down  in  6  hours,  so  that  the  pots  might  admit  to  be  filled  up  again  with  the  second  charge 
of  frit,  which  was  founded  in  4  hours  more.  The  heat  was  briskly  continued,  and  in  the 
course  of  from  12  to  18  hours,  according  to  the  size  of  the  pots,  the  quality  of  the 
fuel,  and  the  draught  of  the  furnace,  the  vitrification  was  complete.  Before  blowing  the 
bottles,  however,  the  glass  must  be  left  to  settle,  and  to  cool  down  to  the  blowing  con- 
sistency, by  shutting  the  care  doors  and  feeding  holes,  so  as  to  exclude  the  air  from  the 
fire-grate  and  the  bottom  of  the  hearth.  The  glass  or  metal  becomes  more  dense,  and 
by  its  subsidence  throws  up  the  foreign  lighter  earthy  and  saline  matters  in  the  form  of 
a  scum  on  the  surface,  which  is  removed  with  skimming  irons.  The  furnace  is  now 
charged  with  coal,  to  enable  it  to  afford  a  working  heal  for  4  or  5  hours,  at  the  end  of 
which  time  more  fuel  is  cautiously  added,  to  preserve  adequate  heat  for  finishing  the 
journey. 

It  is  hardly  possible  to  convey  in  words  alone  a  correct  idea  of  the  manipulations  neces- 
sary to  the  formation  of  a  wine  bottle ;  but  as  the  manufacturers  make  no  mystery  of  this 
matter,  any  person  may  have  an  opportunity  of  inspecting  the  operation.  Six  people  are 
employed  at  this  task  ;  one,  called  a  gatherer,  dips  the  end  of  an  iron  tube,  about  five  feet 
long,  previously  made  red-hot,  into  the  pot  of  melted  metal^  turns  the  rod  round  so  as  to 
surround  it  with  glass,  lifts  it  out  to  cool  a  little,  and  then  dips  and  turns  it  round  again  ; 
and  so  in  succession  till  a  ball  is  formed  on  its  end  sufficient  to  make  the  required  bottle. 
He  then  hands  it  to  the  blower,  who  rolls  the  plastic  lump  of  glass  on  a  smooth  stone  or 
cast-iron  plate,  till  he  brings  it  to  the  very  end  of  the  tube ;  he  next  introduces  the 
pear-shaped  ball  into  an  open  brass  or  cast-iron  mould,  shuts  this  together  by  pressing  a 
pedal  with  his  foot,  and  holding  his  tube  vertically,  blows  through  it,  so  as  to  expand  the 
cooling  glass  into  the  form  of  the  mould.  Whenever  he  takes  his  foot  from  the  pedal-lever, 
the  mould  spontaneously  opens  out  into  two  halves,  and  falls  asunder  by  its  bottom  hinge. 
He  then  lifts  the  bottle  up  at  the  end  of  the  rod,  and  transfers  it  to  the  finisher,  who, 
touching  the  glass  tube  at  the  end  of  the  pipe  with  a  cold  iron,  cracks  off  the  bottle 
smoothly  at  its  mouth-ring.  The  finished  bottles  are  immediately  piled  up  in  the  hot  an- 
nealing arch,  where  they  are  afterwards  allowed  to  cool  slowly  for  24  hours  at  least.  See 
Bottle  Mould. 

2.  Broad  or  spread  vnndow-glass. — This  kind  of  glass  is  called  inferior  window-glass, 
in  this  country,  because  coarse  in  texture,  of  a  wavy  wrinkled  surface,  and  very  cheap, 
but  on  the  Continent  spread  window-glass,  being  made  with  more  care,  is  much 
better  than  ours,  though  still  far  inferior  in  transparency  and  polish  to  crown  glass, 
which  has,  therefore,  nearly  superseded  its  use  among  us.  But  Messrs.  Chance  and 
Hartley,  of  West  Bromwich  near  Birmingham,  have  of  late  years  mounted  a  spread-glass 
work,  where  they  make  British  sheet  glass,  upon  the  best  principles,  and  turn  out  an  ar- 
ticle quite  equal,  if  not  superior,  to  anything  of  the  kind  made  either  in  France  or  Bel- 
gium. Their  materials  are  those  used  in  the  crown-glass  manufacture.  The  vitrifying 
mixture  is  fritted  for  20  or  30  hours  in  a  reverberatory  arch,  with  considerable  stirring 
and  puddling  with  long-handled  shovels  and  rakes ;  and  the  frit  is  then  transferred  by 
shovels,  while  red  hot,  to  the  melting  pots  to  be  founded.  When  the  glass  is  rightly 
vitrified,  settled,  and  brought  to  a  working  heat,  it  is  lifted  out  by  iron  tubes,  as  will  be 
described  under  the  article  Crown  Glass,  blown  into  pears,  which  being  elongated 
into  cylinders,  are  cracked  up  along  one  side,  parallel  to  the  axis,  by  touching  them  with 
a  cold  iron  dipped  in  water,  and  are  then  opened  out  into  sheets.  Glass  cylinders 
are  spread  in  France,  and  at  West  Bromwich,  on  a  bed  of  smooth  stone  Paris-plaster, 
or  laid  on  the  bottom  of  a  reverberatory  arch;  the  cylinder  being  placed  on  its  side 
horizontally,  with  the  cracked  line  uppermost,  gradually  opens  out,  and  flattens  on  the 
hearth.  At  one  time,  thick  plates  were  thus  prepared  for  subsequent  polishing  into  mir- 
rors ;  but  the  glass  was  never  of  very  good  quality  ;  and  this  mode  of  making  mirror-plate 
has  accordingly  been  generally  abandoned. 

The  spreading  furnace  or  oven  is  that  in  which  cylinders  are  expanded  into  tables  or 
plates.  It  ought  to  be  maintained  at  a  brisk  red  heat,  to  facilitate  the  softening  of  the 
glass.  The  oven  is  placed  in  immediate  connexion  with  the  annealing  arch,  so  that  the 
tables  may  be  readily  and  safely  transferred  from  the  former  to  the  latter.  Sometimes 
the  cylinders  are  spread  in  a  large  muffle  furnace,  in  order  to  protect  them  from  being 
tarnished  by  sulphureous  and  carbonaceous  fumes. 

Fig.  709  represents  a  ground  plan  of  both  the  spreading  and  annealing  furnace ;  Jig. 
•710  is  an  oblong  profile  in  the  direction  of  the  dotted  line  x  x^fig.  709. 

a  is  the  fire-place ;  6  6  the  canals  or  flues  through  which  the  flame  rises  into  both 
furnaces;  c  the  spreading  furnace,  upon  whose  sole  is  the  spreading  slab,  d  is  the  cool- 
ing and  annealing  oven ;  e  e  iron  bars  which  extend  obliquely  across  the  annealing  arch, 
and  serve  for  resting  the  glass  tables  against,  during  the  cooling.  /  /  the  channel 
■long  which  the  previously  cracked  cylinders  are  slid,  so  as  to  be  gradually  warmed  { 


GLASS-MAKING.  907 

g  the  opening    .-i  the  spreading  furnace,  for  enabling  the  workmen  to  regulate  the  pro- 


cess ;  h  a  door  in  the  annealing  arch,  for  introducing  the  tools  requisite  for  raising  uf 
and  removing  the  tables. 

In  forming  glass-plates  by  the  extension  of  a  cylinder  into  a  plane,  the  workman  first 
blows  the  lump  of  glass  into  the  shape  of  an  oblong  pear,  the  length  of  which  must  be 
nearly  equal  to  the  length  of  the  intended  plate,  and  its  diameter  such,  that  the  circum- 
ference, when  developed,  will  be  equal  to  the  breadth  of  the  plate.  He  now  rests  the 
blowing  iron  on  a  stool  or  iron  bar,  while  an  assistant,  with  a  pointed  iron,  pierces  a  hole 
into  the  extreme  end  of  the  pear,  in  the  line  of  the  blowing-pipe.  This  opening  is  then 
enlarged,  by  introducing  the  blade  of  a  pair  of  spring-tongs,  while  the  glass  is  turned 
round;  and  by  skilful  management,  the  end  of  the  pear  is  eventually  opened  out  into  a 
cylindrical  mouth.  The  workman  next  mounts  upon  a  stool,  and  holds  the  blowing-iron 
perpendicularly.  The  blown  cylinder  is  now  cracked  off,  a  punto  rod  of  iron  having  been 
previously  stuck  to  its  one  end,  to  form  a  spindle  for  working  the  other  by.  This  rod  has 
a  flai  disc  on  its  end,  or  three  prongs,  which  being  dipped  in  melted  glass,  are  applied  to 
the  mouth  of  the  cylinder.  By  this  as  a  handle,  the  glass  cone  is  carried  to  the  fire,  and 
the  narrow  end  being  heated,  is  next  opened  by  spring  tongs,  and  formed  into  a  cylinder 
of  the  same  size  as  the  other  end.  The  cylinder,  thus  equalized,  is  next  cracked  or  slit 
down  in  its  side  with  a  pair  of  shears,  laid  on  a  smooth  copper  plate,  detached  from  the 
iron  rod,  spread  out  by  heal  into  a  plane  surface,  and  finally  annealed.  This  series  of 
transformations  is  represented  in  fig.  711,  at  a,  b,  c,  d,  e,  f,  g,  h. 

Figs.  712  and  713  represent  a  Bohemian  furnace  in  which  excellent  white  window 
glass  is  founded.  Fig.  712  is  a  longitudinal  section  of  the  glass  and  annealing  furnace. 
Fig.  713  is  the  ground  plan,  a  is  the  ash-pit  vaulted  under  the  sole  of  the  furnace  ;  the 
fire-place  itself  is  divided  into  three  compartments  ;  with  a  middle  slab  at  </,  which  is  hol- 
lowed in  the  centre,  for  collecting  any  split  glass,  and  two  hearth  tiles  or  slabs  b  b.    c  c 

are  the  draught  or  air  holes ;  €  e  are 
arches  upon  which  the  bearing  slabs 
//  partly  rest.  In  the  middle  be- 
tween these  arches,  the  flame  strikes 
upwards  upon  the  pots  g  g,  placed 
as  closely  together  as  possible,  for 
economy  of  room.  A  is  the  breast 
/  wall  of  the  furnace;  ijfig.  713,  the 
opening  through  which  the  pois  are 
introduced;  it  is  bricked  up  as  soon 
as  they  are  set.  k  A:,  is  the  base  of 
the  cone  or  dome  of^  the  furnace; 
I  I  Ij  the  working  orifices,  which 
are  made  larger  or  smaller  accord- 
ing to  the  size  of  the  glass  articles 
to  be  made,  m  is  the  flue  which 
leads  to  the  annealing  stove  n,  with 
an  arched  door.  Exterior  to  this, 
there  is  usually  a  drying  kiln  not 
shown  in  the  figure ;  and  there  are 
adjoining  stoves  called  archesy  for 
drying  and  annealing  the  new  pots  before  they  are  set. 

The  cooling  or  annealing  arch,  or  leer,  is  often  built  independent  of  the  glass-house 
furnace,  is  then  heated  by  a  separate  fire-place,  and  constructed  like  a  very  long  rever- 
beratory furnace.     See  Copper. 

The  leer  pans  or  trays  of  sheet-iron,  are  laid  upon  its  bottom  in  an  oblong  series,  and 
hooked  to  each  other. 

3.  Crown-glass. — The  crown-glass  house  with  its  furnace  is  represented  in  fig.  714. 
where  the  blowing  operation  is  shown  on  the  one  side  of  the  figure,  and  the  flashing  on 
the  other.  The  furnace  is  usually  constructed  to  receive  4  or  6  pots,  of  such  dimen- 
sions as  to  make  about  a  ton  of  glass  each  at  a  time.    There  are,  however,  several  sub- 


713 


sidiary  furnaces  to  a  crown-house. 


H 


114 


908  GLASS-MAKING. 

1.  A  reverberatory  furnace  or  calcar,  ior  calcining  oi 
fritting  the  materials;  2.  a  Oiow 
ing  furnace,  for  blowing  the  peaj- 
shaped  balls,  made  at  the  pot- 
holes, into  large  globes ,  3.  a 
flashing  furnace,  and  bottoming 
hole  for  communicating  a  soften- 
ing heat,  in  expanding  the  globe 
into  a  circular  plate;  4.  the 
annealing  arch  for  the  finished 
tables ;  5.  the  reverberatory  oven 
for  annealing  the  pots  prior  to 
their  being  set  upon  the  founding 
siege. 

The  materials  of  crown  glass 
used  to  be,  fine  sand,  by  measure 
5  parts,  or  by  weight  10 ;  ground 
kelp  by  measure  11  parts,  or  by 
weight  16^;  but  instead  of  kelp, 
soda  ash  is  now  generally  employed. 
From  6  to  8  cwts.  of  sand,  lime, 
^    J      ,  .,,        ,       ,  and  soda-ash,  mixed   together   in 

wooden  boxes  with  a  shovel,  are  thrown  on  the  sole  of  a  large  reverberatory,  such  as  is 
represented  m  the  article  Copper.  Here  the  mixture  is  well"  worked  together,  with  iron 
paddies,  flat  shovels,  and  rakes  with  long  handles ;  the  area  of  this  furnace  being  about 
6  feet  square,  and  the  height  2  feet.  The  heat  soon  brings  the  materials  to  a  pasty  con- 
sistence, when  they  must  be  diligently  turned  over,  to  favor  the  dissipation  of  the  carbon, 
sulphur,  and  other  volatile  matters  of  the  kelp  or  soda  ash,  and  to  incorporate  the  fixed 
ingredients  uniformly  with  the  sand.  Towards  the  end  of  three  hours,  the  fire  is  con- 
siderably raised,  and  when  the  fourth  hour  has  expired,  the  fritting  operation  is  finished. 
Ihe  mass  is  now  shovelled  or  raked  out  into  shallow  cast-iron  square  cases,  smoothed 
down,  and  divided,  before  it  hardens  by  cooling,  into  square  lumps,  by  cross  sections  with 
the  spade.  These  frii-bricks  are  afterwards  piled  up  in  a  large  apartment  for  use;  and 
have  been  supposed  to  improve  with  age,  by  the  efflorescence  of  their  saline  constituents 
into  carbonate  of  soda  on  their  surface. 

The  founding.pots  are  filled  up  with  these  blocks  of  frit,  and  the  furnace  is  powerfully 
urged  by  opening  all  the  subterranean  passages  to  its  grate,  and  closing  all  the  doois 
and  windows  of  the  glass-house  itself.  After  8  or  10  hours  the  vitrification  has  made 
such  progress,  and  the  blocks  first  introduced  are  so  far  melted  down,  that  another  charge 
of  Irit  can  be  thrown  m,  and  thus  the  pot  is  fed  with  frit  till  the  proper  quantity  is  used. 
In  about  16  hours  the  vitrification  of  the  frit  has  taken  place,  and  a  considerable  quanti- 
ty, amounting  often  to  the  cwt.  of  liquid  saline  matter,  fluats  over  the  glass.  This  salt  is 
carefully  skimmed  off  into  iron  pots  with  long  ladles.  It  is  called  Sandiver  or  Glass-gall, 
and  consists  usually  of  muriate  of  soda,  with  a  little  sulphate.  The  pot  is  now  ready  for 
receiving  the  topping  of  cullet,  which  is  broken  pieces  of  window  glass,  to  the  amount  of 
3  or  4  cwts.  This  is  shovelled  in  at  short  intervals;  and  as  its  pressure  forces  up  the 
residuary  saline  matter,  this  is  removed;  for  were  it  allowed  to  remain,  the  body  of  the 
glass  would  be  materially  deteriorated. 

The  heat  is  still  continued  for  several  hours  till  the  elass  is  perfect,  and  the  extrication 
ot  gas  called  the  boil,  which  accompanies  the  fusion  of  crown  glass,  has  nearly  terminated, 
when  the  fire  is  abated,  by  shutting  up  the  lower  vault  doors  and  every  avenue  to  the 
^i!*'f'  ^"^  order  that  the  glass  may  settle  fine.  At  the  end  of  about  40  hours  altogether, 
the  fire  being  slightly  raised  by  adding  some  coals,  and  opening  the  doors,  the  glass  is 
carefully  skimmed,  and  the  working  of  the  pots  commences. 

Before  describing  it,  however,  we  may  state  that  the  marginal  figure  715  shows  the 
'^^  base  of  the  crown -house  cone,  with  the 

four  open  pots  in  two  ranges  on  opposite 
sides  of  the  furnace,  sitting  on  their  raised 
sieges,  at  each  side  of  the  grate.  At  one 
side  of  the  base  the  door  of  the  vault  is 
shown,  and  its  course  is  marked  by  the 
dotted  lines. 

Detailed  description  of  the  crown-glass  furnace^  figs.  716,  717. — It  is  an  oblong  square, 
built  in  the  centre  of  a  brick  cone,  large  enough  to  contain  within  it,  two  or  three  pots 
at  each  side  of  the  grate  room,  which  is  either  divided  as  shown  in  the  plan,  or  runs  the 
whole  length  of  the  furnace,  as  the  manufacturer  chooses.  Fig.  716  is  a  ground  plan,  ami 
Jig.  Ill  a  front  elevation,  of  a  six-pot  furnace.     1,  2,  3,  fig.  717,  are  the  working  holes 


GLASS-MAKING. 


909 


for  the  purposes  of  ventilation,  of  putting  in  the  materials,  and  of  taking  out  the  metal 
to  be  wrought.  4,  5,  6,  7,  are  pipe  holes  for  warming  the  pipes  before  beginning  to  work 
with  them.  8,  9,  10,  are  foot  holes  for  mending  the  pots  and  sieges.  11  is  a  barof  iroii 
for  binding  the  furnace,  and  keeping  it  from  swelling. 


The  arch  is  of  an  elliptic  form ;  though  a  barrel  arch,  that  is,  an  arch  shaped  like  the 
half  of  a  barrel  cut  longwise  through  the  centre,  is  sometimes  used.  But  this  soon  gives 
way  when  used  in  the  manufacture  of  crown  glass,  although  it  does  very  well  in  the  clay- 
furnace  used  for  bottle  houses.  , 

The  best  stone  for  building  furnaces  is  fire-stone,  from  Coxgreen  in  the  neighbor- 
hood of  Newcastle.  Its  quality  is  a  close  grit,  and  it  contains  a  greater  quantity  of 
talc  than  the  common  fire-stone,  which  seems  to  be  the  chief  reason  of  its  resisting  the 
fire  better.  The  great  danger  in  building  furnaces  is,  lest  the  cement  at  the  top  should 
give  way  with  the  excessive  heat,  and  by  dropping  into  the  pots,  spoil  the  metal.  The  top 
should  therefore  be  built  with  stones  only,  as  loose  as  they  can  hold  together  after  the  cen- 
tres are  removed,  and  without  any  cement  whatever.  The  stones  expand  and  come  quite 
close  together  when  annealing ;  an  operation  which  takes  from  eight  to  fourteen  days  at 
most.    There  is  thus  less  risk  of  any  thing  dropping  from  the  roof  of  the  furnace. 

The  inside  of  the  square  of  the  furnace  is  built  either  of  Stourbridge  fire-clay  annealed, 
or  the  Newcastle  fire-stone,  to  the  thickness  of  sixteen  inches.  The  outside  is  built  of 
common  brick  about  nine  inches  in  thickness. 

The  furnace  is  thrown  over  an  ash-pit,  or  cave,  as  it.  is  called,  which  admits  the  atmo- 
spheric air,  and  promotes  the  combustion  of  the  furnace.  This  cave  is  built  of  stone 
until  it  comes  beneath  the  grate  room,  when  it  is  formed  of  fire-brick.  The  abutments 
are  useful  for  binding  and  keeping  the  furnace  together,  and  are  built  of  masonry.  The 
furnaces  are  stoutly  clasped  with  iron  all  round,  to  keep  them  tight.  In  four-pot  furnaces 
this  is  unnecessary,  provided  there  be  four  good  abutments. 

Fig.  718  is  an  elevation  of  the  flashing  furnace.  The  outside  is  built  of  common  brick, 
the  inside  of  fire-brick,  and  the  mouth  or  nose  of  Stourbridge  fire-clay. 

Fig.  719  is  the  annealing  kiln.  It  is  built  of  common  brick,  except  round  the  grate 
room,  where  fire-brick  is  used. 

Few  tools  are  needed  for  blowing  and  flashing  crown-glass.  The  requisite  ball  of 
plastic  glass  is  gathered,  in  successive  layers  as  for  bottles,  on  the  end  of  an  iron  tube,  and 
rolled  into  a  pear-shape,  on  a  cast-iron  plate ;  the  workman  taking  care  that  the  air 
blown  into  its  cavity  is  surrounded  with  an  equal  body  of  glass,  and  if  he  perceives  any 
side  to  be  thicker  than  another,  he  corrects  the  inequality  by  rolling  it  on  the  sloping 
iron  table  called  marver,  (marbre).    He  now  heats  the  bulb  in  the  fire,  and  rolls  it  so  a. 


'  ll 


910 


GLASS-MAKING. 


to  form  the  g.ass  upon  the  end  of  the  tube,  and  by  a  dexterous  swing  or  two  he 
lengthcHs  it,  as  shown  in  i,  fig.  720.  To  extend  the  neck  of  that  pear,  he  next  rolls  it 
over  a  smooth  iion  rod,  turned  round  in  a  horizontal  direction,  into  the  shape  Kyfig.  720. 
By  further  expansion  ai  the  blowing-furnace,  he  now  brings  it  to  the  shape  l,  repre- 
sented inyig.  720. 

I       K       L      720 
718 


^  '  .  ' 


Trr 


i-   I ;  I    ■    irx 


&■ 


VT:  i;  f 


This  spheroid  having  become  cool  and  somewhat  stiff,  is  next  carried  to  the  bottoming 
hole  (like  fig.  718),  to  be  exposed  to  the  action  of  flame.  A  slight  wall  erected  before 
one  half  of  this  hole,  screens  the  workman  from  the  heat,  but  leaves  room  for  the  globe  to 
pass  between  it  and  the  posterior  wall.  The  blowins-pipe  is  made  to  rest  a  little  way  from 
the  neck  of  the  globe,  on  a  hook  fixed  in  the  front  wall ;  and  thus  may  be  made  easily  lo  re- 
volve on  Its  axis,  and  by  giving  centrifugal  force  to  the  globe,  while  the  bottom  of  it,  or. 
part  opposite  to  the  pipe,  is  softened  by  the  heat,  it  soon  assumes  the  form  exhibited  in 
M,  fig.  720. 

In  this  stale  the  flattened  globe  is  removed  from  the  fire,  and  its  rod  being  rested  on 
the  casherbox  covered  with  coal  cinders,  another  workman  now  applies  the  end  of  a  solid 
iron  rod  tipped  with  melted  glass,  called  a  punto,  to  the  nipple  or  prominence  in  the 
middle ;  and  thus  attaches  it  to  the  centre  of  the  elobe,  while  the  first  workman  cracks 
oil  the  globe  by  touching  its  tubular  neck  with  an  iron  chisel  dipped  in  cold  water.  The 
workman  having  thereby  taken  possession  of  the  globe  by  its  bottom  or  knobbed  pole 
attached  to  his  punty  rod,  he  now  carries  it  to  another  circular  opening,  where  he  exposes 
It  to  the  action  of  moderate  flame  with  regular  rotation,  and  thus  slowly  heats  the  thick 
projecting  remains  of  the  former  neck,  and  opens  it  slightly  out,  as  shown  at  n,  in 
fig.  <20.  He  next  hands  it  to  the  flasher,  who,  restinj?  the  iron  rod  in  a  hook  placed 
near  the  side  of  the  orifice  a,  fig.  718,  wheels  it  rapidly  round  opposite  to  a  powerful 
flame,  till  it  assumes  first  the  fieureo,  and  finally  that  of  a  flat  circular  table. 

The  flasher  then  walks  ofl^  with  the  table,  keeping  up  a  slight  rotation  as  he  moves 
along,  and  when  it  is  sufficiently  cool,  he  turns  down  his  rod  into  a  vertical  position, 
and  lays  the  table  flat  on  a  dry  block  of  fire-clay,  or  bed  of  sand,  when  an  assistant 
nips  It  ofl^  from  the  punio  with  a  pair  of  long  iron  shears,  or  cracks  it  ofi'  with  a  toucl 
of  cold  iron.  The  loose  table  or  plate  is  lastly  lifted  up  horizontally  on  a  double  prongec 
iron  fork,  introduced  into  the  annealing  arch /g.  719  and  raised  on  edge;  an  assistant  with 
a  long-kneed  fork  preventing  it  from  falling  too  rapidly  backwards.  In  this  arch  a  great 
S?"y  ^®^'^^*^^?^^^^  *^^  P'^^  "P  ^"  i''on  frames,  and  slowly  cooled  from  a  heat  of  about 
600°  to  100°  F.,  which  takes  about  24  hours ;  when  they  are  removed.  A  circular  plate 
or  table  of  about  5  feet  diameter  weighs  on  an  average  9  pounds. 

4.  Flint  g/aw.— This  kind  of  glass  is  so  called  because  originally  made  with  calcined 
flints,  as  the  silicious  ingredient.  The  materials  at  present  employed  in  this  country 
for  the  rinest  flint  glass  or  crystal,  are  first,  Lynn  sand,  calcined,  sifted,  and  washed : 
second,  an  oxyde  of  lead,  either  red  lead  or  litharge;  and  third,  pearlash.  The  pearl- 
ash  of  commerce  must  however  be  purified  by  digesting  it  in  a  very  little  hot  water, 
which  dissolves  the  carbonate  of  potash,  and  leaves  the  foreisn  salts,  chiefly  sulphate  of 
potash,  muriate  of  potash,  and  muriate  of  soda.  The  solution  of  the  carbonate  being 
allowed  to  cool  and  become  clear  in  lead  pans,  is  then  run  oflT  into  a  shallow  iron  boiler, 
and  evaporated  to  dryness.  Nitre  is  generally  added  as  a  fourth  ingredient  of  the  body 
of  the  glass ;  and,  it  serves  to  correct  any  imperfections  which  might  arise  from 
accidental  combustible  particles,  or  from  the  lead  being  not  duly  oxydized.  The  above 
four  substances  constitute  the  main  articles;  to  which  we  may  add  arsenic  and  man- 
ganese, introduced  in  very  small  quantities,  to  purify  the  color  and  clear  up  the 
transparency  of  the  glass.  The  black  oxyde  of  manganese,  when  used  in  such  quantity 
only  as  to  peroxydize  the  iron  of  the  sand,  simply  removes  the  creen  tinge  caused  by  the 
iron;  but  if  more  manganese  be  added  than  accomplishes  that  purpose,  it  will  give  a 
purple  tinge  to  the  slass ;  and  in  fact,  most  manufacturers  prefer  to  have  an  excess 
rather  than  a  defect  of  manganese,  since  cut  glass  has  its  brilliancy  increased  by  a  faint 
lilach  hue.  The  arsenic  is  supposed  to  counteract  the  injury  arising  from  excess  of  man- 
ganese, but  is  itself  very  apt  on  the  other  hand  to  communicate  some  degree  of  opalescence. 


GLASS-MAKING. 


911 


or  at  least,  to  impair  the  lustre  of  the  glass.  When  too  much  manganese  has  been 
added,  the  purple  tinge  may  indeed  be  removed  by  any  carbonaceous  matter,  as  by 
thrusting  a  wooden  rod  down  into  the  liquid  glass ;  but  this  cannot  be  done  with  good 
cflTect  in  practice,  since  the  final  purple  tinge  is  not  decided  till  the  glass  is  perfectly 
formed,  and  then  the  introduction  of  charcoal  would  destroy  the  uniformity  of  the  whole 
,ontents  of  the  pot. 

The  raw  materials  of  flint  glass  are  always  mixed  with  about  a  third  or  a  fourth  of 
their  weight  of  broken  crystal  of  like  quality ;  this  mixture  is  thrown  into  the  pot 
with  a  shovel ;  and  more  is  added  whenever  the  preceding  portions  by  melting  subside ;  the 
object  being  to  obtain  a  pot  full  of  glass,  to  facilitate  the  skimming  oflf  the  impurities 

and  sandiver.  The  mouth  of  the  pot 
is  now  shut,  by  applying  clay-lute  round 
the  stopper,  with  the  exception  of  a 
small  orifice  below,  for  the  escape  of 
the  liquid  saline  matter.  Flint  glass 
requires  about  48  hours  for  its  complete 
vitrification,  though  the  materials  be 
more  fusible  than  those  of  crown  glass ; 
in  consequence  of  the  contents  of  the 
pot  being  partially  screened  by  its  cover 
from  the  action  of  the  fire,  as  also  from 
the  lower  intensity  of  the  heat. 

Fig.  721  represents  a  flint  glass 
house  for  6  pots,  with  the  arch  or  leer 
on  one  side  for  annealing  the  crystal 
ware.  In  fig.  722,  the  base  of  the 
cone  is  seen,  and  the  glass  pots  in  situ 
on  their  platform  ranged  round  the  cen- 
tral fire  grate.  The  dotted  line  denotes 
the  contour  of  the  furnace,  ^g.  721. 

Whenever  the  glass  appears  fine, 
and  is  freed  from  its  air  bubbles,  which 
it  usually  is  in  about  36  hours,  the 
heat  is  suflTered  to  fall  a  little  by  closing 
the  bottom  valves,  &c.,  that  the  pot 
may  settle ;  but  prior  to  working  the 
metal  the  heat  is  somewhat  raised  again. 
It  would  be  useless  to  describe  the 
manual  operations  of  fashioning  the 
various  articles  of  the  flint-glass  manufacture,  because  they  are  indefinitely  varied  to  suit 
the  conveniences  and  caprices  of  human  society. 

Every  diflferent  flint-house  has  a  peculiar  proportion  of  glass  materials.  The  following 
have  been  oflfered  as  good  practical  mixtures. 

1.  Fine  white  sand      ------ 

Red  lead  or  litharge  -  -  .  -  - 

Refined  pearlashes  .  -  ,  -  - 

Nitre  .-.---- 

Arsenic  and  manganese,  a  minute  quantity. 

In  my  opinion,  the  proportion  of  lead  is  too  great  in  the  above  recipe,  which  is  given 
on  the  authority  of  Mr.  James  Geddes,  of  Leith.  The  glass  made  with  it  would  be 
probably  yellowish  and  dull. 

2.  Fine  sand             ----.-. 
Litharge  ---..--- 
Refined  pearlashes  (carbonate  of  potash,  with  5  per  cent,  of  water) 
Nitre 

100-0 
To  these  quantities  from  30  to  50  parts  of  broken  glass  or  euUet  are  added ;  with  about 
a  two-thousandth  part  of  manganese,  and  a  three-thousandth  part  of  arsenic.     But  man- 
ganese varies  so  extremely  in  its  purity,  and  contains  often  so  much  oxyde  of  iron,  the 
nothing  can  be  predicated  as  to  its  quantity  previously  to  trial. 

M.  Payen,  an  eminent  manufacturing  chemist  in  France,  says  that  the  composition  of 
crystal  does  not  deviate  much  from  the  following  proportions  ; — 

Wood  fire.  Coal  fire 

Silicious  sand     •        -        ...        3  3 

Minium     --....2  2^ 

Carbonate  of  potash  .        .        -        -        1|  If 


300  parts. 
200 

80 

20 


912 


GLASS-MAKING. 


I  conceive  that  this  glass  contains  too  much  lead  and  potash.  Such  a  mlTture  will  nrc« 
duce  a  dull  metal,  rery  attractive  of  moisture;  defects  to  which  the  French  crown-glass 
also  IS  subject.  ° 

The  flint-glass  leer  for  annealing  glass,  is  an  arched  gallery  or  large  flue,  about  36  feet 
long,  3  feet  high,  4  wide;  having  iis  floor  raised  above  2  feet  above  the  ground  of  the 
glass-house.  The  hot  air  and  smoke  of  a  fire-place  at  one  end  pass  along  this  gallery, 
and  are  discharged  by  a  chimney  8  or  10  feet  short  of  the  other  end.  On  the  floor  of  the 
vault,  large  iron  trays  are  laid  and  hooked  to  each  other  in  a  series,  which  are  drawn  from 
the  fire  end  towards  the  other  by  a  chain,  wound  about  a  cylinder  by  a  winch-handle  pro- 
jecting  through  the  side.  The  flint-glass  articles  are  placed  in  their  hot  state  into  the 
iray  next  the  fire,  which  is  moved  onwards  to  a  cooler  station  whenever  it  is  filled,  and 
an  empty  tray  i^  set  m  its  place.  Thus,  in  the  course  of  about  20  hours,  the  glass  ad- 
vances  to  the  cool  end  thoroughly  annealed. 

Besides  colorless  transparent  glass,  which  forms  the  most  important  part  of  this 
manufacture,  various  colored  glasses  are  made  to  suit  the  taste  of  the  public.  The 
taste  at  Paris  was  lately  for  opaline  crystal;  which  may  be  prepared  by  adding  to  the 
above  composilion  (No^  2)  phosphate  of  lime,  or  well  burnt  bone  ash  in  fine  powder! 
washed  and  dried.  The  article  must  be  as  uniform  in  thickness  as  possible,  and 
speedily  worked  into  shape,  with  a  moderate  heat.  Oxyde  of  tin,  putty,  was  formerly 
used  for  making  opalescent  glass,  but  the  lustre  of  the  body  was  always  impaired  by  its 
means.  j        f  j    « 

Crystal  vessels  have  been  made  recently  of  which  the  inner  surface  is  colorless,  and  aU 
the  external  facets  colored.  Such  works  are  easily  executed.  The  end  of  the  blowino- 
rod  must  be  dipped  first  in  the  pot  containing  colorless  glass,  to  form  a  bulb  of  a  certafa 
size,  which  being  cooled  a  little  is  then  dipped  for  an  instant  into  the  poc  oi  colored  glass. 
The  two  layers  are  associaied  without  intermixture;  and  when  the  article  is  finished  in 
Its  form,  It  is  white  within  and  colored  without.  Fluted  lines,  somewhat  deeply  cut,  pass 
through  the  colored  coat,  and  enter  the  colorless  one;  so  that  when  they  cross,  their  ends 
alone  are  colored.  ' 

For  some  time  past,  likewise,  various  crystal  articles  have  been  exhibited  in  the  market 
With  colored  enamel-fignres  on  their  surface,  or  with  white  incrustations  of  a  silverv 
lustre  in  their  interior.  The  former  are  prepared  by  placing  the  enamel  object  in  the 
brass  mould,  at  the  place  where  it  is  sought  to  be  attached.  The  bulb  of  glass  being  put 
mto  the  mould,  and  blown  while  very  hot,  the  small  plate  of  enamel  gets  cemented  to  the 
surface.  For  making  the  white  argentine  incrustations,  small  figures  are  prepared  with 
an  impalpable  powder  of  dry  porcelain  paste,  cemented  into  a  solid  by  means  of  a  little 
gypsum  plaster.  When  these  pieces  are  thoroughly  dried,  they  are  laid  on  the  glass 
while  It  IS  red  hot,  and  a  large  patch  of  very  liquid  glass  is  placed  above  it,  so  as  to  encase 
It  and  forrn  one  body  with  the  whole.  In  this  way  the  incrustation  is  completely  enclosed  • 
and  the  polished  surface  of  the  crystal,  which  scarcely  touches  it,  gives  a  brilliant  aspect' 
pleasing  to  the  eye.  ^     * 

A  uniform  flint-glass,  free  from  striae,  or  wreath,  is  much  in  demand  for  the  optician 
It  would  appear  that  such  an  article  was  much  more  commonly  made  by  the  En«'lish 
manufacturers  many  years  ago,  than  at  present ;  and  that  in  improving  the  brilliancy  of 
crystal-glass  they  have  injured  its  fitness  for  constructing  optical  lenses,  which  depends 
not  so  rnuch  on  its  whiteness  and  lustre  as  on  the  layers  of  different  densities  being  parallel 
to  each  other.  The  oxyde  of  lead  existing  in  certain  parts  of  a  potful  of  glass  in  greater 
proportion  than  m  other  parts,  increases  the  density  unequally  in  the  same  mass,  so  that 
the  adjoining  strata  are  often  very  different  in  this  respect.  Even  a  potful  of  pretty 
uniform  glass,  when  it  stands  some  time  liquid,  becomes  eventually  unequable  by  the  sub- 
sidence of  the  denser  portions;  so  that  striae  and  gelatinous  appearances  begin  to  manifest 
themselves,  and  the  glass  becomes  of  little  value.  Glass  allowed  to  cool  slowly  in  mass  in 
the  pot  is  particularly  fall  of  wreath  ;  and  if  quickly  refrigerated,  that  is,  in  two  or  three 
hours.  It  IS  apt  to  split  into  a  multitude  of  minute  splinters,  of  which  no  use  can  be  made 
For  optical  purposes,  the  glass  must  be  taken  out  in  its  liquid  state,  being  gathered  oil 
the  end  of  the  iron  rod  from  the  central  portion  of  a  recently  skimmed  pot,  after  the  uooer 
layers  have  been  worked  off  in  general  articles. 

•  ^'^"^'^^^^^^  «^  Brennets  near  Geneva,  appears  to  have  hit  upon  processes  that  fur- 
nished  almost  certainly  pieces  of  flint-glass  capable  of  forming  good  lenses  of  remarkable 
dimensions,  even  of  11  inches  diameter;  of  adequate  density  and  transparency  and 
nearly  free  from  stria.  M.  Cauchoix,  the  eminent  French  optician,  says,  that  out  of 
ten  object  glasses,  4  inches  in  diameter,  made  with  M.  Guinand's  flint  glass  eight  oi 
nine  turned  out  very  good,  while  out  of  an  equal  number  of  object  glasses  made  of  the 
flint  glass  of  the  English  and  French  manufactories,  only  one,  or  twoai  most,  were  found 
serviceable.  The  means  by  which  M.  Guinand  arrived  at  these  results  have  not  been 
published.  He  has  lately  died,  and  it  is  not  known  whether  his  son  be  in  possession  of 
ms  secret.  *^ 


GLASS-MAKING. 


913 


An  achromatic  object  glass  for  telescopes  and  microscopes  consists  of  at  least  two 
lenses ;  the  one  made  with  glass  of  lead,  or  flint-glass,  and  the  other  with  crown-glass  j 
the  former  possessing  a  power  of  dispersing  the  colored  rays  relatively  to  its  mean  refrac- 
tive power,  much  greater  than  the  latter ;  upon  which  principle  the  achromatism  of  the 
image  is  produced,  by  reuniting  the  different  colored  rays  into  one  focus.  Flint-glass  to 
be  fit  for  this  delicate  purpose  must  be  perfectly  homogeneous,  or  of  uniform  density 
throughout  its  substance,  and  free  from  wavy  veins  or  wreaths ;  for  every  such  inequal- 
ity would  occasion  a  corresponding  inequality  in  the  refracti'n  and  dispersion  of  the 
light ;  like  what  is  perceived  in  looking  through  a  thick  and  thin  solution  of  g'.!m-arabic 
imperfectly  mixed.  Three  plans  have  been  prescribed  for  obtaining  homogeneous  pieces 
of  optical  glass :  1.  to  lift  a  mass  of  it  in  large  ladles,  and  let  it  cool  in  them ;  2.  to 
pour  it  out  from  the  pots  into  moulds;  3.  to  allow  it  to  cool  in  the  pots,  and  afterwards 
to  cut  it  off  in  horizontal  strata.  The  last  method,  which  is  the  most  plausible,  seldom 
affords  pieces  of  uniform  density,  unless  peculiar  precautions  have  been  adopted  to  settle 
the  flint  glass  in  uniform  strata ;  because  its  materials  are  of  such  unequal  density,  the 
oxyde  of  lead  having  a  specific  gravity  of  8,  and  silica  of  2*7,  that  they  are  apt  to  stand 
at  irregular  heights  in  the  pots. 

One  main  cause  of  these  inequalities  lies  in  the  construction  of  the  furnace,  whereby 
the  bottom  of  the  pot  is  usually  much  less  heated  than  the  upper  part.  In  a  plate  glass 
furnace  the  temperature  of  the  top  of  the  pot  has  been  found  to  be  130'  Wedgew.,  while 
that  of  the  bottom  was  only  110°,  constituting  a  difference  of  no  less  than  2610°  F. 
The  necessary  consequence  is  that  the  denser  particles  which  subside  to  the  bottom, 
during  the  fusion  of  the  materials,  and  after  the  first  extrication  of  the  gases,  must 
remain  there,  not  being  duly  agitated  by  the  expansive  force  of  caloric,  acting  from 
below  upwards. 

The  preparation  of  the  best  optical  glass  is  now  made  a  great  mystery  by  one  or  two 
proficients.  The  following  suggestions,  deduced  from  a  consideration  of  principles,  may 
probably  lead  to  some  improvements,  if  judiciously  applied.  The  great  object  is  to  coun- 
teract the  tendency  of  the  glass  of  lead  to  distribute  itself  into  strata  of  different  densi- 
ties ;  which  may  be  effected  either  by  mechanical  agitation  or  by  applying  the  greates* 
heat  to  the  bottom  of  the  pot.  But  however  homogeneous  the  glass  may  be  thereby  made, 
its  subsequent  separation  into  strata  of  different  densities  must  be  prevented  by  rapid 
cooling  and  solidification.  As  the  deeper  the  pots,  the  greater  is  the  chance  of  unequal 
specific  gravity  in  their  contents,  it  would  be  advisable  to  make  them  wider  and  shal- 
lower than  those  in  use  for  making  ordinary  glass.  The  intermixture  may  be  effected 
either  by  lading  the  glass  out  of  one  pot  into  another  in  the  furnace,  and  back  again,  with 
copper  ladles,  or  by  stirring  it  up  with  a  rouser,  then  allowing  it  to  settle  for  a  short 
time,  till  it  becomes  clear  and  free  from  air  bubbles.  The  pot  may  now  be  removed  from 
the  furnace,  in  order  to  solidify  its  contents  in  their  homogeneous  state ;  after  which  the 
glass  may  be  broken  in  pieces,  and  be  perfected  by  subjecting  it  to  a  second  fusion ;  or, 
what  is  easier  and  quicker,  we  may  form  suitable  discs  of  glass  without  breaking  down 
the  potful,  by  lifting  it  out  in  flat  copper  ladles  with  iron  shanks,  and  transferring  the 
lumps  after  a  little  while  into  the  annealing  leer. 

To  render  a  potful  of  glass  homogeneous  by  agitation,  is  a 
more  difficult  task,  as  an  iron  rod  would  discolor  it,  and  a 
copper  rod  would  be  apt  to  melt.  An  iron  rod  sheathed  in 
laminated  platinum  would  answer  well,  but  for  its  expense. 
A  stone-ware  tube  supported  within  by  a  rod  of  iron,  might 
also  be  employed  for  the  purpose  in  careful  hands ;  the  stir- 
ring being  repeated  several  times,  till  at  last  the  glass  is 
suffered  to  stiffen  a  little  by  decrease  of  temperature.  It 
must  then  be  allowed  to  settle  and  cool,  after  which  the  pot, 
being  of  small  dimensions,  may  be  drawn  out  of  the  fire. 

2.  The  second  method  of  producing  the  desired  uniformity 
of  mixture,  consists  in  applying  a  greater  heat  to  the  bottom 
than  to  the  upper  part  of  the  melting  pot.  Fig.  723  repre- 
sents in  section  a  furnace  contrived  to  effect  this  object.  It 
is  cylindrical,  and  of  a  diameter  no  greater  than  to  allow  the 
flames  to  play  round  the  pot,  containing  from  three  to  four 
cwts.  of  vitreous  materials,  a  is  the  pot,  resting  upon  the 
arched  grid  6  a,  built  of  fire-bricks,  whose  apertures  are  wide 
enough  to  let  the  flames  rise  freely,  and  strike  the  bottom  and 
sides  of  the  vessel.  From  IJ  to  2  feet  under  that  arch,  the 
fuel  grate  c  d  is  placed,  b  c  are  the  two  working  openings 
for  introducing  the  materials,  and  inspecting  the  progress  oi 
the  fusion ;  they  must  be  closed  with  fire-tiles  and  luted  with 
fire-clay  at  the  beginning  of  the  process.   At  the  back  of  the  furnace,  opposite  the  mouth 


li 


'I  : 

■il 


[M 


914 


GLASS-MAKING. 


of  the  fire-place  there  is  a  door-way,  which  is  bricked  up,  except  upon  occasion  of  put- 
ting m  and  taking  out  the  pot.  The  draught  is  regulated  by  means  of  a  slide-plate  upon 
the  mouth  of  ihe  ash-pit  /.  The  pot  being  heated  to  the  proper  pitch,  some  purified 
pearJash  mixed  wilh  fully  twice  ils  weight  of  colorless  quartz  sand,  is  to  be  thrown  into 
It,  and  after  the  coniplele  fusion  of  this  mixture,  the  remaining  part  of  the  sand  alon?  with 
the  oxyde  of  lead  (fine  litharge)  is  to  be  strown  upon  the  surface.  These  silicious  par- 
ticles in  their  Jescent  serve  to  extricate  the  air  from  the  mass.  Whenever  the  whole  is 
lused,  the  heat  must  be  strongly  urged,  to  ensure  a  complete  uniformity  of  combination 
by  the  internal  motions  of  the  particles.  As  soon  as  the  glass  has  been  found,  by  making 
test  vials  to  be  perfectly  fine,  the  fire  must  be  withdrawn,  the  two  working  holes  must 
be  opened,  as  well  as  the  mouths  of- the  fire-place  and  ash-pit,  to  admit  free  in-ress  to 
cooling  currents  of  air,  so  as  to  congeal  the  liquid  mass  as  quickly  as  possible:  a  condi- 
tion  essential  to  the  uniformity  of  the  glass.  It  may  be  worth  while  to  stir  it  a  little 
with  the  pottery  rod  at  the  commencement  of  the  coolin-  process.  The  solidified  glass 
may  be  afterwards  detached  by  a  hammer  in  conchoidal  discs,  which,  after  chipping  off 
their  edges,  are  to  be  placed  in  proper  porcelain  or  stone-ware  dishes,  and  exposed  to  a 
soltenmg  heat,  in  order  to  give  them  a  lenticular  shape.  Great  care  must  be  taken  that 
the  heat  thus  applied  by  the  muffle  furnace  be  very  eqtiable,  for  otherwise  wreaths 
might  be  ver5'  readily  reproduced  in  the  discs.  A  small  oven,  upon  the  plan  of  a 
bakers,  is  best  fitted  for  this  purpose,  which  being  healed  to  dull  redness,  and  then 
exunguished,  is  ready  to  soAen  and  afterwards  anneal  the  conchoidal  pieces. 

Gumand  s  dense  optical  flint  glass,  of  specific  gravity  3-616,  consists,  by  analysis,  of 
oxyde  of  lead,  43-0o ;  silica,  44-3  ;  and  potash,  11-75;  but  requires  for  its  formation  the 
following  mgredients :  100  pounds  of  ground  quartz;  100  pounds  of  fine  red  lead:  35 
pounds  of  purified  potash  ;  and  from  2  to  4  pounds  of  saltpetre.  As  this  species  of  glass 
is  injured  by  an  excess  of  potash,  it  should  be  compounded  with  rather  a  defect  of  it 
and  melted  by  a  proportionably  higher  or  longer  heat.  A  good  optical  glass  has  been 
made  in  Germany  with  7  parts  of  pure  red  lead,  3  parts  of  finely  ground  quartz,  and  2 
parts  of  calcined  borax.  >  «"«  ^ 

5.  Plate  glass. 

This,  like  English  crown-glass,  has  a  soda  flux;  whereas  flint-glass  requires  potash 
and  is  never  of  good  quality  when  made  with  soda.  We  shall  distribute  our  account  of 
this  manufacture  under  two  heads. 

1.  The  different  furnaces  and  principal  machines,  without  whose  knowledge  it  would 
be  impossible  to  understand  the  several  processes  of  a  plate-glass  factory. 

2.  The  materials  which  enter  into  the  composition  of  this  kind  of  glass,  and  the  series 
of  operations  which  they  undergo;  devoting  our  chief  attention  to  the  changes  and  im- 
provements  which  long  experience,  enlightened  by  modern  chemistry,  has  introduced  into 
the  great  manufactory  of  Saint-Gobin,  in  France,  under  the  direction  of  M.  Tassaert  It 
may  however  be  remarked,  that  the  English  plate-glass  manufacture  derives  peculiar 
advantages  from  the  excellence  of  its  grinding  and  polishing  machinery. 

The  clay  for  making  the  bricks  and  pots  should  be  free  from  lime  and  iron,  and  very 
refractor)'.  It  is  mixed  wilh  the  powder  of  old  pots  passed  through  a  silk  sieve.  If  the 
clay  be  very  plastic  it  will  bear  ils  own  weight  of  the  powder,  but  if  shorter  in  quality. 
It  will  take  only  three  fifths.  But  before  mingling  it  with  the  cement  of  old  pots,  it  must 
be  dried,  bruised,  then  picked,  ground,  and  finally  elutriated  by  agitation  with  water 
decantation  through  a  hair  sieve,  and  subsidence.  The  clay  fluid  after  passing  the  sieve 
IS  called  slip  (coulis). 

The  furnace  is  built  of  dry  bricks,  cemented  with  slip,  and  has  at  each  of  its  four 
angles  a  peculiar  annealing  arch,  which  communicates  with  the  furnace  interiorly,  and 
thence  derives  suflicient  heat  to  effect  'in  part,  if  not  wholly,  the  annealing  of  the  pots 
which  are  always  deposited  there  a  long  time  before  they  are  used.  Three  of  these 
arches,  exclusively  appropriated  to  this  purpose,  are  called  pot-arches.  The  fourth  is 
called  the  arcA  of  ihe  materials,  because  it  serves  for  drying  them  before  they  are  founded, 
tach  arch  has,  moreover,  a  principal  opening  called  the  throat,  another  called  bonnard, 
by  the  French  workmen,  through  which  fire  may  be  kindled  in  the  arch  itself,  when  it 
was  thought  to  be  necessary  for  the  annealing  of  the  pots ;  a  practice  now  abandoned. 
Ihe  duration  of  a  furnace  is  commonly  a  year,  or  at  most  14  months ;  that  of  the  arches 
IS  30  years  or  upwards,  as  they  are  not  exposed  to  so  strong  a  heal. 

In  the  manufacture  of  plate-glass  two  sorts  of  crucibles  are  employed,  called  the 
pots  and  the  basins  (cuvettes).  The  first  serve  for  containing  the  materials  to  be 
founded,  and  for  keeping  them  a  long  time  in  the  melted  state.  The  cuvettes  receive  the 
melted  glass  after  it  is  refined,  and  decant  it  out  on  the  table  to  be  rolled  into  a  plate. 
Three  pots  hold  liquid  glass  for  six  small  basins,  or  for  three  large  ones,  the  latter  bein^ 
employed  for  making  mirrors  of  great  dimensions,  that  is,  100  inches  long  and  up. 


GLASS-MAKING. 


915 


wards.  Furnaces  have  been  lately  constructed  with  6  pots,  and  12  cuvettes,  8  of  which 
are  small,  and  4  large;  and  cuvettes  of  three  sizes  are  made,  called  small,  middling,  and 
large.  The  small  are  perfect  cubes,  the  middling  and  the  large  ones  are  obh.ng  parallel 
opipeds.  Towards  the  middle  of  their  height,  a  notch  or  groove,  two  or  three  inches 
broad,  and  an  inch  deep,  is  left,  called  the  girdle  of  the  cuvette,  by  which  part  they  are 
grasped  with  the  tongs,  or  rather  are  clamped  in  the  iron  frame.  This  frame  goes  round 
the  four  sides  of  the  small  cuvettes,  and  may  be  placed  indifferently  upon  all  their  sides; 
in  the  other  cuvettes,  the  girdle  extends  only  over  the  two  large  sides,  because  they  cau- 
not  be  turned  up.     See  m  T,Jig.  724,  p.  918. 

The  pot  is  an  inverted  truncated  cone,  like  a  crown  glass  pot.  It  is  about  30  inches 
high,  and  from  30  to  32  inches  wide,  including  its  thickness.  There  are  only  a  few  inches 
of  diflerence  between  the  diameter  of  the  top  and  that  of  vhe  bottom.  The  bottom  is 
3  inches  thick,  and  ihe  body  turns  gradually  thinner  till  it  is  an  inch  at  the  mouth  of  the 
pot. 

The  large  building  or  factory,  of  which  the  melting  furnace  occupies  the  middle  space, 
IS  called  the  halle  in  French.  At  Ravenhead  in  Lancashire  it  is  called  the  foundry,  and 
is  of  magnificent  dimensions,  being  probably  the  largest  apartment  under  one  roof  'm 
Great  Britain,  since  ils  length  is  339  feel,  and  ils  breadth  155.  The  famous  halle  of  Si. 
Gobin  IS  174  feet  by  120.  Along  the  two  side  walls  of  the  halky  which  are  solidly  con- 
structed of  hewn  stone,  there  are  openings  like  those  of  common  ovens.  These  ovens^ 
destined  for  the  annealing  of  the  newly  cast  plates,  bear  the  name  of  carquaises.  Their 
soles  are  raised  two  feet  and  a  half  above  the  level  of  the  ground,  in  order  to  bring  then 
into  the  same  horizontal  plane  with  the  casting  tables.  Their  length,  amounting  some- 
times to  30  feet,  and  their  breadth  to  20,  are  required  in  order  to  accommodate  6,  8,  or 
even  10  plates  of  glass,  alongside  of  each  other.  The  front  aperture  is  called  the  throat, 
and  the  back  door  the  little  throat  (gueulette).  The  carquaise  is  heated  by  means  of  a 
fire-place  of  a  square  form  called  a  tisar,  which  extends  along  its  side. 

The  founding  or  melting  furnace  is  a  square  brick  building  laid  on  solid  foundations 
being  from  8  to  10  feet  in  each  of  ils  fronts,  and  rising  inside  into  a  vault  or  crown  about 
10  feet  high.  At  each  angle  of  this  square,  a  small  oven  or  arch  is  constructed,  likewise 
vaulted  withm,  and  communicating  with  the  melting  furnace  by  square  flues,  called  lu- 
nettes, through  which  it  receives  a  powerful  heat,  though  much  inferior  to  that  round  the 
pots.  The  arches  are  so  distributed  as  that  two  of  the  exterior  sides  of  the  furnace  stand 
wholly  free,  while  the  two  other  sides,  on  which  the  arches  encroach,  offer  a  free  spate 
ol  only  three  feet.  In  this  interjacent  space,  two  principal  openings  of  the  furnace,  of 
equal  size  m  each  side,  are  left  in  the  building.  These  are  called  tunnels.  They  are 
destined  for  the  introduction  of  the  pots  and  the  fuel. 

On  looking  through  the  tunnels  into  the  inside  of  the  furnace,  we  perceive  to  the  right 
hand  and  the  left,  along  the  two/ree  sides,  two  low  platforms  or  sieges,  at  least  30  inches 
m  height.and  breadth.     See  Jigs,  7l5,  7l7.  s    ,        c«»»  ou  mtues 

These  sieges  (seals)  being  intended  to  support  the  pots  and  the  cuvettes  filled  witk 
heavy  materials,  are  terminated  by  a  slope,  which  ensures  the  solidity  of  the  fire-clar 
mound.  The  slopes  of  the  two  sieges  extend  towards  the  middle  of  the  furnace  so  near 
as  to  leave  a  space  of  only  from  6  to  10  inches  between  them  for  the  hearth.  The  end 
of  this  is  perforated  with  a  hole  sufficiently  large  to  give  passage  to  the  liquid  glass  of  a 
broken  pot,  while  the  rest  is  preserved  by  lading  it  from  the  mouth  into  the  adjoining 

In  the  two  large  parallel  sides  of  the  furnace,  other  apertures  are  left  much  smaller 
ihan  the  tunnels,  which  are  called  ouvreaux  (peep  holes).  The  lower  ones,  or  the  ouvreauz 
en  bas,  called  cuvette  openings,  because,  being  allotted  to  the  admission  of  these  ve<«selaL 
they  are  exactly  on  a  level  wilh  the  surface  of  the  sieges,  and  with  the  floor  of  the  halU 
Plates  of  cast-iron  form  the  thresholds  of  these  openings,  and  facilitate  the  ingress  and 
egress  of  the  cuvettes.  The  apertures  are  arched  at  top,  with  hewn  stone  Uke  the  tun- 
nels, and  are  18  inches  wide  when  the  cuvettes  are  16  inches  broad. 

The  upper  and  smaller  apertures,  or  the  higher  ouvreaux  called  the  lading  boles,  be^ 
cause  they  serve  for  Iransvasing  the  liquid  glass,  are  three  in  number,  and  a.e  placed  31 
or  32  inches  above  the  surface  of  the  sieges.  As  the  pots  are  only  30  inches  high,  k 
becomes  easy  to  work  through  these  openings  either  in  the  pots  or  the  cttw««.  The 
pots  stand  opposite  to  the  two  pillars  which  separate  the  openings,  so  that  a  space  is  left 
between  them  for  one  or  more  cuvettes  according  to  the  size  of  the  latter.  Il  is  obvious 
that  if  the  tunnels  and  ouvreaux  were  left  open,  the  furnace  would  not  draw  or  take  the 
requisite  founding  heat.  Hence  the  openings  are  shut  by  means  of  fire-tUes.  These  are 
put  in  their  places,  and  removed  by  means  of  two  holes  left  in  them,  in  correspondence 
with  the  two  prongs  of  a  large  iron  fork  supported  by  an  axle  and  two  iron  wheels,  aiul 
terminated  by  two  handles  which  the  workmen  lay  hold  of  when  they  wish  to  move 
the  tile. 

The  closing  of  the  tunnel  is  more  complex.    When  it  is  shut  or  ready  for  the  finng, 


« 


t 

;■ 
I- 
i 

I 


916 


GLASS-MAKING. 


II 


the  aperture  appears  built  up  with  bricks  and  mortar  from  the  top  of  the  arch  to  the 
middle  of  the  tunnel.  The  remainder  of  the  door-way  is  closed ;  1.  on  the  two  sides 
down  lo  the  bottom,  by  a  small  upright  wall,  likewise  of  bricks,  and  8  inches  broad, 
called  walls  of  the  glaye;  2.  by  an  assemblage  of  pieces  called  pieces  of  the  glaye^  be- 
cause the  whole  of  the  closure  of  the  tunnel  bears  the  name  of  glaye.  The  upper  hole, 
4  inches  square,  is  called  the  tisar,  through  which  billets  of  wood  are  tossed  into  the 
fire.  Fuel  is  also  introduced  into  the  posterior  openings.  The  fire  is  always  kept  up  on 
the  hearth  of  the  tunnel,  which  is,  on  this  account,  4  inches  higher  than  the  furnace- 
hearth,  in  order  that  the  glass  which  may  accidentally  fall  down  on  it,  and  which  does 
not  flow  off  by  the  bottom  hole,  may  not  impede  the  combustion.  Should  a  body  of  glass, 
however,  at  any  time  obstruct  the  grate,  it  must  be  removed  with  rakes,  by  opening  the 
tunnel  and  dismounting  the  fire-tile  stoppers  of  the  glaye. 

Formerly  wood  fuel  alone  was  employed  for  heating  the  melting-furnaces  of  the 
mirror-plale  manufactory  of  Saint  Gobin ;  but  within  these  few  years,  the  Director  of 
the  works  makes  use  with  nearly  equal  advantage  of  pit-coal.  In  the  same  establishment, 
two  melting  furnaces  may  be  seen,  one  of  which  is  fixed  with  wood,  and  the  other  with 
coals.  Without  any  difference  being  perceptible  in  the  quality  of  the  glass  furnished  by 
either.  It  is  not  true,  as  has  been  stated,  that  the  introduction  of  pit-coal  has  made  it 
necessary  to  work  with  covered  pots  in  order  to  avoid  the  discoloration  of  the  materials, 
or  that  more  alkali  was  required  to  compensate  for  the  diminished  heat  in  the  covered 
pots.  They  are  not  now  covered  when  pit-coal  is  used,  and  the  same  success  is  obtained 
as  heretofore  by  leaving  the  materials  two  or  three  hours  longer  in  the  pots  and  the  cu- 
rettes. The  construction  of  the  furnaces  in  which  coal  is  burned,  is  the  same  as  that 
with  wood,  with  slight  modifications.  Instead  of  the  close  bottomed  hearth  of  the  wood 
furnace,  there  is  an  iron  grate  in  the  coal-hearth  through  which  the  air  enters,  aad  the 
waste  ashes  descend. 

When  billets  of  wood  were  used  as  fuel,  they  were  well  dried  beforehand,  by  being 
placed  a  few  days  on  a  frame- work  of  wood  called  the  wheel,  placed  two  feet  above  the 
furnace  and  its  arches,  and  supported  on  four  pillars  at  some  distance  from  the  angles  of 
the  building. 

Composi'ion  of  plate-glass. — This  is  not  made  now,  as  formerly,  by  random  trials. 
The  progress  of  chemistry,  the  discovery  of  a  good  process  for  the  manufacture  of  soda 
from  sea  salt,  which  furnishes  a  pure  alkali  of  uniform  power,  and  the  certain  methods 
of  ascertaining  its  purity,  have  rendered  this  department  of  glass-making  almost  entirely 
new,  in  France.  At  Saint  Gobin  no  alkali  is  employed  at  present  except  artificial 
crystals  of  soda,  prepared  at  the  manufactory  of  Chauny,  subsidiary  to  that  establish- 
ment. Leaden  chambers  are  also  erected  there  for  the  production  of  sulphuric  acid 
from  sulphur.  The  first  crop  of  soda  crystals  is  reserved  for  the  plate-glass  manufac- 
ture, the  other  crystals  and  the  mother-water  salts  are  sold  to  the  makers  of  inferior 
glass. 

At  the  mirror-plate  works  of  Ravenhead,  near  St.  Helen's  in  Lancashire,  soda  crys- 
tals, from  the  decomposition  of  the  sulphate  of  soda  by  chalk  and  coal,  have  been  also 
tried,  but  without  equal  success  as  at  Saint  Gobin ;  the  failure  being  unquestionably  due 
to  the  impurity  of  the  alkali.  Hence,  in  the  English  establishment  the  soda  is  obtained 
by  treating  sea-salt  with  pearl-ash,  whence  carbonate  of  soda  and  muriate  of  potash  re- 
sult. The  latter  salt  is  crystallized  out  of  the  mingled  solution,  by  evaporation  at  a  mod- 
erate heat,  for  the  carbonate  of  soda  does  not  readily  crystallize  till  the  temperature  of  the 
solution  falls  below  60°  Fahr.  When  the  muriate  of  potash  is  thus  removed,  the  alkaline 
carbonate  is  evaporated  to  dryness. 

Long  experience  at  Saint  Gobin  has  proved  that  one  part  of  dry  carbonate  of  soda  is 
adequate  to  vitrify  perfectly  three  parts  of  fine  silicious  sand,  as  that  of  the  mound  of 
Aumont  near  Senlis,  of  Alum  Bay  in  the  Isle  of  Wight,  or  of  Lynn  in  Norfolk.  It 
is  also  known  that  the  degree  of  heat  has  a  great  influence  upon  the  vitrification,  and 
that  increase  of  temperat  \re  will  compensate  for  a  certain  deficiency  of  alkali ;  for  it  is 
certain  that  a  very  strong  lire  always  dissipates  a  good  deal  of  the  soda,  and  yet  the  glass 
is  not  less  beautiful.  The  most  perfect  mirror-plate  has  constantly  afforded  to  M.  Vau- 
quelin  in  analysis,  a  portion  of  soda  inferior  lo  what  had  been  employed  in  its  formation. 
Hence,  it  has  become  the  practice  to  add  for  every  100  parts  of  cullet  or  broken  plate 
that  is  mixed  with  the  glass  composition,  one  part  of  alkali,  to  make  up  for  the  loss  that 
the  old  glass  must  have  experienced. 

To  the  above  mentioned  proportions  of  sand  and  alkali  independently  of  the  cullet 
which  may  be  used,  dry  slaked  lime  carefully  sifted  is  to  be  added  to  the  amount  of  one 
seventh  of  the  sand ;  or  the  proportion  will  be,  sand  7  cwts. ;  quicklime  1  cwt. ;  dry 
carbonate  of  soda  2  cwts.  and  37  lbs. ;  besides  cullet.  The  lime  improves  the  quality  of 
the  glass;  rendering  it  less  brittle  and  less  liable  to  change.  The  preceding  quantities 
oC  materials,  suitably  blended,  have  been  uniformly  found  to  aflbrd  most  advantageous 
results.    The  practice  formerly  was  to  dry  that  mixture  as  soon  as  it  was  made,  in  iht 


GLASS-MAKING.  917 

arch  for  the  materials,  but  it  has  been  ascertained  that  this  step  may  be  dispensed  with 
and  the  small  portion  of  huniidity  present  is  dissipated  almost  instantVXr  they  are 
™rtl'e''.'„[T"'T     Tf  •  '""V  ^''^^  n''«^i«««'y  applied  to  the  inside  of  th?  ^l 

but  .iZ.n  JT  ^^  •  r  \l'^  ^T ^'  L*?^  materials  are  neither  fritted  nor  even  dried, 
but  shovel  ed  directly  into  the  pot;  this  is  called  founding  raw.  Six  workmen  arc 
employed  m  shovelling-in  the  materials  either  frilled  or  othem^se  for  the  X  of  ex^ 

a;  S?"whX;rTh-'''  '"T;  r''''  T'^^-.  P^^  ^^^^^  «""«'  mi'xlureti^rrodTd 
at  nrst ,  whenever   his  is  melted,  the  second  third  is  thrown  in,  and  then  the  last     These 
three  sia^s  are  called  the  first,  second,  and  third  fusion  or  foundin- 
thr^f^  •"  ^^^  ^"'''^IJ  P'"a^\'<^^>  the  founding  and  refinins  were  both  executed  in 
the  ,K)ts  and  It  was  not  till  the  glass  was  refined,  that  it  was  laded  into  the  cTmtJs 
where  it   remained  only  3  hours,  the  time  necessary  for  the  disengagement  of  "he  S 
bubbles  mtrodticed  by  the  transvasion,  and  for  giving  the  metal  Ihl  proper  co^^^^^^^^^ 
for  casting.     At  present,  the  period  requisite  for  founding  and  refining^  is  equaU?  divldS 
between  the  pots  and  the  cuvettes.    The  materials  are  left  16  hours  in  tife  pots  Ind  ^ 
many  m  the  cuvettes;  so  that  in  32  hours  the  glass  is  ready  to  be  cas  .     Dunn,  the  la^ 
two  or  three  hours,  the  fireman  or  tiseur  ceases  to  add  fuel ;    all  the  openings  are  shut 
and  the  glass  is  allowed  to  assume  the  requisite  fluidity;  an  operation  SK^^Lgthe 
glass,  or  performing  the  ceremony.  ^  '  i-  cu  siuppmg  me 

The  transfer  of  the  glass  into  the  cuvettes,  is  called  lading,  (trejetage).    Before  this  is 
done  the  cuvettes  are  cleared  out,  that  is,  the  dass  remaininf  on  tLirUtomi  removed 
and   the  ashes  of  the  firing.      They  are  lifted   red   hot  out  of  the  furnace  Tv   the 

wUh  w^t'r^T  '   '"  I'  ^'T''^'  ""^    P'^*=^   «"   ^^   •»•«"   P^^te  nelra   tub   fiM 
with  water.     The  workmen,  by  means  of  iron  paddles  6  feet  long,  flattened  at  one  end 
and  hammered  to  an  edge,  scoop  out  the  fluid  gkss  expediliouslv"lndXowit!nto  water 
tlilT       "*'  "'''  '''"'"'^  '"  '^'  ^"^'^^'''  ^'^^  *  ^''^  ^i«"^^^  afterwards  the  Taing 
In  this  operation,  ladles  of  wrought  iron  are  employed,  furnished  with  Ion*  handles 

Ttelfti'sFr^'et  chart';  T]  ^'^^"^"^  ^  "^?-  'p^^^^  -  ladingToles,  and  imm^! 

thfpl    ^.f  In  f        .    ^^  ""^  ^^*''  '^^"^  ^^^  ^^^^^'^^^^^     Each  workman  dips  his  ladle  only 

the  te  rr^.V./'"^     '  VTT  '"'^  '^^  *=""""^-    ^>'  '^^'^  three  immersions  (whe^e 

nto  a      b  f^n    f     V^'f^'  S^"  large  iron  spoon  is  heated  so  much  that  when  plunged 

The  founding,  refining,  and  ceremony,  being  finished,  they  next  try  whether  the  al«« 

is^S  'rr^L  ^^  ''ll  "■^"'  '^^  ^".^  ^^  ^  ^^  '^  clipped  int^o'the'tuc'etw'h 
IS  called  drawing  the  glass;   the  portion  taken  up  being  allowed  to  runoff"  nlturallv 

assumes  a  pear-shape,  from  the  appearanceof  which,  they  can  judge  if  thrcon^iste^^^^^^^^ 

mZ'  '"^  ;^  ""^  "'!;  ^"^^'"^  ^^'"^•"-  '^  «"  ^'  ""''t,  the  c«i^/.f  are  taken  ouT'^ 
fu  nace,  and  conveyed  to  the  part  of  the  halle  where  their  contents  are  to  be  poured  ouu 
This  process  requires  peculiar  instruments  and  manipulations. 

Ca*/t«?.— While  the  glass  is  refining,  that  is,  coming  to  its  highest  noint  of  nerfeetinn 
preparation  ,s  made  for  the  most  important  process,'the  casUng  ofX  pkte  whose 
success  crowns  all  the  preliminary  labors  and  cares.  ^The  oven  or  mrZ  Jdeslii^d  to 
receive  and  anneal  the  plate  is  now  heated  by  its  small  fire  or  /tW,  t?sucTa  pS 
Its  sole  may  have  the  same  temperature  as  that  of  the  plates,  being  nearly  red  hot  at  the 
moment  of  their  being  introduced.  An  unequal  degree  of  heat  in  thlmrauaise  would 
rf'r  K?*""''  '^'';"  ^'*'''  7.^"  '"^^^"^  ^^^'^  i^  ^hen  rolled  towards  theTontdrrir 
tile  oven.'  "''"'  "^  ^"""'"'  '"^  '''  ''''^''''  ''  ^^""^^'^^  ^^'^'^^^^  ^«  ^he  level  ofThe  sole  of 

The  table  T,  fig.  724,  is  a  mass  of  bronre,  or  now  preferably  cast  iron  about  10  feet 
long,  o  feet  broad,  and  from  6  to  7  inches  thick,  supported  by  a  frameof  carne^trv  which 
res  .on  ,hree  cast  iron  wheels.  At  the  end  of 'the  table  oppLheTthat  neTt  to  t'hefr^^^ 
of  fh«  oveq,  IS  a  very  strona;  frame  of  timber-work  called  rh*»  nnLit  I  ?  ^  ^5  *^"' 
which  the  bronze  roller  which  spreads  the  Rlasll  ,;id:'i;fo  eL'd  a^lthVc'^^^^^  T^" 
IS  5  feet  long  by  1  foot  ,n  diameter;  it  is  thick  in  the  metal  but  Lllow  in  the  axfs  The 
same  ro Her  can  serve  onlv  for  two  nlat^e  «»  r»n«  «„.♦•  u         ""^ow  m  ine  axis,     ine 

an'l  the  firsf  .«  l«i,l  VciT.  !  /  m^^^J^t  One  casting,  when  another  is  put  in  its  place, 
an'  the  first  is  laid  aside  to  coo  ;  for  otherwise  the  hot  roller  would  at  a  third  castine 
make  the  plate  expand  unequa  y,  and  cause  it  to  rrai.lr      iVh^  ti        1?  casting 

aeiion  iHpv  nr*.  in.ii  oc.M-  .«  c  «-«*««!>e  ii  lo  cracK.     When  the  rollers  are  not  m 

the  two  sfdes  or-  i^  ^TmI  n  X  v  ''''?^'"  I""^"'^^''  ^'^^  '^^'^  ^"^P'^'y^d  by  sawvers.  On 
de.t  Z  to  .nl,r^  the  rnlW  f'  "'^f  '''  ^^""'*''  ^'^  ^^^  P"^"«'  ^ars  of  bronze,  /,  /, 
ts rle'mLT^^^^^^^  tX^fein^rhufa;^  ^"','  ^'^  '''^T'.  ^^  ''^'^ 


ii 


!!l 


•  (' 


-ii 


.V- 


918 


GLASS-MAKING. 


The  tongs  t,  fig.  724,  are  made  of  four  iron  bars,  bent  mio  a  square  frame  in  their 
middle,  for  embracing  the  bucket.  Four  chains  proceeding  from  the  corners  of  the  frame 
V  are  united  at  their  other  ends  into  a  ring 'which  fits  into  the  hook  of  the  craoe. 

724 


Things  bting  thus  arranged,  all  the  workmen  of  the  foundry  co-operate  in  the  manipn- 
lations  of  the  casting.  Two  of  them  fetch,  and  place  quickly  in  front  of  one  of  the  lower 
openings,  the  small  cuvette-carriage,  which  bears  a  forked  bar  of  iron,  having  two  pron?s 
corresponding  to  the  two  holes  left  in  the  fire-tile  door.  This  fork,  mounted  on  the  axle 
of  two  cast-iron  wheels,  extends  at  its  other  end  into  two  branches  terminated  by  handles, 
by  which  the  workmen  move  the  fork,  lift  out  the  tile  stopper,  and  set  it  down  against 
the  outer  wall  of  the  furnace. 

The  instant  these  men  retire,  two  others  push  forward  into  the  opening  the  extre- 
mity of  the  tongs-carriage,  so  as  to  seize  the  bucket  by  the  girdle,  or  rather  to  clamp  it. 
At  the  same  time,  a  third  workman  is  busy  with  an  iron  pinch  or  long  chisel,  detaching 
the  bucket  from  its  seat,  to  which  it  often  adheres  by  some  spilt  -lass  ;  whenever  it  is 
free,  he  withdraws  it  from  the  furnace.  Two  powerful  branches  of  iron  united  by  a 
bolt,  like  two  scissor  blades,  which  open,  come  together,  and  join  by  a  quadrant  near  the 
other  end,  form  the  tongs-carriage,  which  is  monnied  upon  two  wheels  like  a  truck. 

The  same  description  will  apply  almost  wholly  to  the  iron-plate  carriage,  on  which 
the  bucket  is  laid  the  moment  it  is  taken  out  of  the  furnace ;  the  only  difl!erence  in  its 
construction  is,  that  on  the  bent  iron  bars  which  form  the  tail  or  lower  steps  of  this  car- 
nage (m  place  of  the  tones)  is  permanently  fastened  an  iron  plate,  on  which  the  bucket 
IS  placed  and  carried  for  the  casting. 

Whenever  the  cuvelU  is  set  upon  its  carriage,  it  must  be  rapidly  wheeled  to  its  station 
near  the  crane.  The  tongs  t  above  described  are  now  applied  to  the  girdle,  and  are  then 
hooked  upon  the  crane  by  the  suspension  chains.  In  this  position  the  bucket  is  skim- 
med by  means  of  a  copper  tool  called  a  sabre,  because  it  has  nearly  the  shape  of  that 
weapon.  Every  portion  of  the  matter  removed  by  the  sabre  is  thrown  into  a  copper 
ladle  (j>oc}ie  de  gamin),  which  is  emptied  from  time  to  time  into  a  cistern  of  water.  After 
being  skimmed,  the  bucket  is  lifted  up,  and  brushed  very  clean  on  its  sides  and  bottom  ; 
then  by  the  double  handles  of  the  suspension-tongs  it  is  swung  round  to  the  table,  where 
It  is  seized  by  the  workmen  appointed  to  turn  it  over;  the  roller  having  been  previously 
laid  on  Its  ruler-bars,  near  the  end  of  the  table  which  is  in  contact  with  the  annealing 
oven.  The  cuvette-men  begin  to  pour  out  towards  the  right  extremity  e  of  the  roller,  and 
terminate  when  it  has  arrived  at  the  left  extremity  d.  While  preparing  to  do  so,  and 
at  the  instant  of  casting,  two  men  place  within  the  ruler-bar  on  each  side,  that  is,  between 
the  bar  and  the  liquid  glass,  two  iron  instruments  called  handsy  rriy  rn,  m,  m,  which  pre- 
vent the  glass  from  spreading  beyond  the  rulers,  while  another  draws  along  the  table  the 
wiping  bar  c,  <•,  wrapped  in  linen,  to  remove  dust,  or  any  small  objects  which  may  inter- 
pose between  the  table  and  the  liquid  glass. 

Whenever  the  melted  glass  is  poured  out,  two  men  spread  it  over  the  table,  guiding 
the  roller  slowly  and  steadily  along,  beyond  the  limits  of  the  «lass,and  then  run  it  smartly 
mto  the  wooden  standard  prepared  for  its  reception,  in  placeof  the  trestles  v,  v. 

The  empty  bucket,  while  still  red-hot,  is  hung  a?ain  upon  the  crane,  set  on  its  plate- 
iron  carriage,  freed  from  its  tongs,  and  replaced  in  the  furnace,  to  be  speedily  cleared 
out  anew,  and  charged  with  fresh  fluid  from  the  pots.  If  while  the  roller  glides  along, 
the  two  workmen  who  stand  by  with  picking  tools,  perceive  tears  in  the  matter  in  ad- 
vance of  the  roller,  and  can  dexterously  snatch  them  out,  they  are  suitably  rewarded, 
according  to  the  spot  where  the  blemish  lay,  whether  in  the  centre,  where  it  would 
have  proved  most  detrimental,  or  near  the  edge.     These  tears  proceed  usually  from 


GLASS-MAKING. 


919 


nnall  portions  of  semi-vitrified  matter  which  fall  from  the  vault  of  the  furnace,  and  from 
their  density  occupy  the  bottom  of  the  cuvettes. 

While  the  plate  is  still  red-hot  and  ductile,  about  2  inches  of  its  end  opposite  to  the 
earquaise  door  is  turned  up  with  a  tool;  this  portion  is  called  the  head  of  the  mirror ; 
against  the  outside  of  this  head,  the  shovel,  in  the  shape  of  a  rake  without  teeth,  is  ap- 
plied, with  which  the  plate  is  eventually  pushed  into  the  oven,  while  two  other  workmen 
press  upon  the  upper  part  of  the  head  with  a  wooden  pole,  eight  feet  long,  to  preserve 
the  plate  in  its  horizontal  position,  and  prevent  its  being  warped.  The  plate  is  now  left 
for  a  few  moments  near  the  throat  of  ♦he  earquaise^  to  give  it  solidity ;  after  which  it  is 
pushed  farther  in  by  means  of  a  very  long  iron  tool,  whose  extremity  is  forked  like  the 
letter  y,  and  hence  bears  that  name ;  and  is  thereby  arranged  in  the  most  suitable  spot  for 
allowing  other  plates  to  be  introduced. 

However  numerous  the  manipulations  executed  from  the  moment  of  withdrawing  the 
cuvette  from  the  furnace,  till  the  cast-plate  is  pushed  into  the  annealing  oven,  I  have  seen 
them  all  performed  in  less  than  five  minutes;  such  silence,  order,  regularity, and  despatch 
prevail  in  the  establishment  of  Saint-Gobin. 

When  all  the  plates  of  the  same  casting  have  been  placed  in  the  earquaise,  it  is  sealed 
up,  that  is  to  say,  all  its  orifices  are  closed  with  sheets  of  iron,  surrounded  and  made  tight 
with  plastic  loam.  With  this  precaution,  the  cooling  goes  on  slowly  and  equably  in  every 
part,  for  no  cooling  current  can  have  access  to  the  interior  of  the  oven. 

After  they  are  perfectly  cooled,  the  plates  are  carefully  withdrawn  one  after  another, 
keeping  them  all  the  while  in  a  horizontal  position,  till  they  are  entirely  out  of  the  car' 
quaise.  As  soon  as  each  plate  is  taken  out,  one  set  of  workmen  lower  quickly  and 
steadily  the  edge  which  they  hold,  while  another  set  raise  the  opposite  edge,  till  the  glass 
be  placed  upright  on  two  cushions  stuflled  with  straw,  and  covered  with  canvass.  In 
this  vertical  position  they  pass  through,  beneath  the  lower  edge  of  the  plate,  three  girths 
or  straps  each  four  feet  long,  thickened  with  leather  in  their  middle,  and  ending  in 
wooden  handles ;  so  that  one  embraces  the  middle  of  the  plate,  and  the  other  two,  the 
ends.  The  workmen,  six  in  number,  now  seize  the  handles  of  the  straps,  lift  up  the 
glass  closely  to  their  bodies,  and  convey  it  with  a  regular  step  to  the  warehouse.  Here 
the  head  of  the  plate  is  first  cut  oflf  with  a  diamond  square,  and  then  the  whole  is  atten- 
tively examined,  in  reference  to  its  defects  and  imperfections,  to  determine  the  sections 
which  must  be  made  of  it,  and  the  eventual  size  of  the  pieces.  The  pairings  and  small 
cuttings  detachet  are  set  aside,  in  order  to  be  ground  and  mixed  with  the  raw  materials 
of  another  glass-pot. 

The  apartment  in  which  the  roughing-down  and  smoothing  of  the  plates  is  performed, 
is  furnished  with  a  considerable  number  of  stone  tables  truly  hewn  and  placed  apart  like 
billiard  tables,  m  a  horizontal  position,  about  2  feet  above  the  ground.  They  are  rec- 
tangular, and  of  diflerent  sizes  proportional  to  the  dimensions  of  the  plates,  which  they 
ought  always  to  e^iceed  a  little.  These  tables  are  supported  either  on  stone  piUars  or 
wfoden  frames,  and  are  surrounded  with  a  wooden  board  whose  upper  edge  stands  some- 
what below  their  level,  and  leaves  in  the  space  between  it  and  the  stone  all  round  an  in- 
terval of  3  or  4  inches,  of  which  we  shall  presently  see  the  use. 

A  cast  plate,  unless  formed  on  a  table  quite  new,  has  always  one  of  its  faces,  the  one 
next  the  table,  rougher  than  the  other;  and  with  this  face  the  roughing-down  begins. 
With  this  view,  the  smoother  face  is  cemented  on  the  stone  table  with  Paris-plaster.  But 
often,  instead  of  one  plate,  several  are  cemented  alongside  of  each  other,  those  of  the  same 
thickness  being  carefully  selected.  They  then  take  one  or  more  crude  plates  of  about  one 
third  or  one  fourth  the  surface  of  the  plate  fixed  to  the  table,  and  fix  it  on  them  with 
liquid  gypsum  to  the  large  base  of  a  quadrangular  truncated  pyramid  of  stone,  of  a  weight 
proporiioned  to  its  extent,  or  about  a  pound  to  the  square  inch.  This  pyramidal  muUer, 
if  small  sized,  bears  at  each  of  its  angles  of  the  upper  face  a  peg  or  ball,  which  the 
grinders  lay  hold  of  in  working  it;  but  when  of  greater  dimension,  there  is  adapted  to  it 
horizontally  a  wheel  of  slight  construction,  8  or  10  feet  in  diameter,  whose  circumference 
is  made  of  wood  rounded  so  as  to  be  seized  with  the  hand.  The  upper  plate  is  now 
rubbed  over  the  lower  ones,  with  moistened  sand  applied  between. 

This  operation  is  however  performed  by  machinery.  The  under  plate  being  fixed  or 
imbedded  in  stucco,  on  a  solid  table,  the  upper  one  likewise  imbedded  by  the  same 
cement  m  a  cast  iron  frame,  has  a  motion  of  circumrotalion  given  to  it  closely  resem- 
bling that  communicated  by  the  human  hand  and  arm,  moist  sand  being  supplied 
between  them.  While  an  eccentric  mechanism  imparts  this  double  rotatory  movement 
to  the  upper  plate  round  its  own  centre,  and  of  that  centre  rojind  a  point  in  the  lower 
plate,  this  plate,  placed  on  a  moveable  platform,  changes  its  position  by  a  slow  horizonta. 
motion,  both  m  the  direction  of  its  length  and  its  breadth.  By  this  ingenious  con- 
trivance, which  pervades  the  whole  of  the  grinding  and  polishing  machinery,  a  remark- 
able regularity  of  friction  and  truth  of  surface  is  produced.  When  the  plates  are  suffi- 
eiently  worked  on  one  face,  they  are  reversed  in  the  frames,  and  worked  together  on 


'i 


II 


II 


u 


1  B 


920 


GLASS-MAKIT^G. 


the  ether.    The  Paris  plaster  is  usually  colored  red,  in  order  to  show  any  defects  in  tht 
^la$<:. 

The  smoothing  of  the  plates  is  effected  on  the  same  principles  by  the  use  of  moist 
emery  washed  to  successive  degrees  of  fineness,  for  the  successive  stages  of  the  operation ; 
and  the  polishing  process  is  performed  by  rubbers  of  hat-felt  and  a  thin  paste  of  colcothar 
and  water.  The  colcothar,  called  also  crocus,  is  red  oxyde  of  iron  prepared  by  the  igni- 
tion of  copperas,  with  grinding  and  elutriation  of  the  residuum. 

The  last  part  or  the  poli>*hing  process  is  performed  by  hand.  This  is  managed  by  fe- 
males, who  slide  one  plate  over  another,  while  a  little  moistened  putty  of  tin  finely  levi- 
gated is  thrown  between. 

Large  mirror-plates  are  now  the  indispensable  ornaments  of  every  large  and  sumptuous 
apartment ;  they  diffuse  lustre  and  gayety  round  them,  by  reflecting  the  rays  of  light  in  a 
thousand  lines,  and  by  multiplying  indefinitely  tne  images  of  objects  placed  between  op- 
posile  parallel  planes. 

The  silvering  of  plane  mirrors  consists  in  applying  a  layer  of  tin-foil  alloyed  with  mer- 
cury to  their  posterior  surface.  The  workshop  for  executing  this  operation  is  provided 
with  a  great  many  smooth  tables  of  fine  freestone  or  marble,  truly  levelled,  bavin?  round 
Iheir  contour  arising  ledge,  within  which  there  is  a  gutter  or  groove  which  terminates  by 
a  slight  slope  in  a  spout  at  one  of  the  corners.  These  tables  rest  upon  an  axis  of  wood 
or  iron  which  runs  along  the  middle  of  their  length  ;  so  that  they  may  be  inclined  easily 
into  an  angle  with  the  horizon  of  12  or  13  degrees,  by  means  of  a  hand-screw  fixed  be- 
low. They  are  also  furnished  with  brushes,  with  glass  rules,  with  rolls  of  woollen  stuff, 
several  pieces  of  flannel,  and  a  great  many  weights  of  stone  or  cast-iron. 

The  glass-tinner,  standing  towards  one  angle  of  his  table,  sweeps  and  wipes  its  surface 
with  the  greatest  care,  along  the  whole  surface  to  be  occui»ied  by  the  mirror-plate;  then 
taking  a  sheet  of  tin-foil  adapted  to  his  purpose,  he  spreads  it  on  the  table,  and  applies 
it  closely  with  a  brush,  which  removes  any  folds  or  wrinkles.     The  table  being  hori- 
zontal, he  pours  over  the  tin  a  small  quantity  of  quicksilver,  and  spreads  it  with  a  roll 
of  woollen  stuff;  so  that  the  tin-foil  is  penetrated  and  apparently  dissolved  by  the  mer- 
cury.    Placing  now  two  rules,  to  the  right  and  to  the  left,  on  the  borders  of  the  sheet,  he 
pours  on  the  middle  a  quantity  of  mercury  sufficient  to  form  everywhere  a  layer  about 
the  ihickness  of  a  crown  piece;  then  removing  with  a  linen  rag  the  oxyde  or  other  im- 
purities, he  applies  to  it  the  edge  of  a  sheet  of  paper,  and  advances  it  about  half  an  inch. 
Meanwhile  another  workman  is  occupied  in  drying  very  nicely  the  surface  of  the  glass 
that  is  to  be  silvered,  and  then  hands  it  to  the  master  workman,  who,  laying  it  flat, 
places  its  anterior  edge  first  on  the  table,  and  then  on  the  slip  of  paper;  now  pushing 
the  glass  forwards,  he  takes  care  to  slide  it  along  so  that  neither  air  nor  any  coal  of 
oxyde  on  the  mercury  can  remain  beneath  the  plate.     When  this  has  reached  its  position, 
he  fixes  it  there  by  a  weieht  applied  on  its  side,  and  gives  the  table  a  gentle  slope,  to 
run  off*  all  the  loose  quicksilver  by  the  gutter  and  spout.     At  the  end  of  five  minutes  he 
covers  the  mirror  with  a  piece  of  flannel,  and  loads  it  with  a  great  many  weights  which 
are  left  upon  it  for  twenty-four  hours,  under  a  gradually  increased  inclination  of  the  table. 
By  this  time  the  plate  is  ready  to  be  taken  off  the  marble  table,  and  laid  on  a  wooden  one 
•loped  like  a  reading  desk,  with  its  under  edge  resting  on  the  ground,  while  the  upper  is 
raised  successively  to  difl'erent  elevations  by  means  of  a  cord  passing  over  a  pulley  in  the 
ceiling  of  the  room.     Thus  the  mirror  has  its  slope  graduated  from  day  to  day,  till 
it  finally  arrives  at  a  vertical  position.     About  a  month  is  required  for  draining  out 
the  superfluous  mercury  from  large  mirrors;  and  from  18  to  20  days  from  those   of 
moderate  size.     The  sheets  of  tin-foil  being  always  somewhat  larger  than  the  glass 
plate,  their  edges  must  be  paired  smooth  oflT,  before  the  plate  is  lifted  ofl"  the  marble 
table. 

Process  for  silvering  concave  mirrors. — Having  prepared  some  very  fine  Paris  plaster  by 
passing  it  through  a  silk  sieve,  and  some  a  little  coarser  passed  through  hair-cloth,  the 
first  is  to  be  made  into  a  creamy  liquor  with  water,  and  after  smearing  the  concave  surface 
of  the  glass  with  a  film  of  olive  oil,  the  fine  plaster  is  to  be  poured  into  it,  and  spread  by 
turning  about,  till  a  layer  of  plaster  be  formed  about  a  tenth  of  an  inch  thick.  The 
second  or  coarse  plaster,  being  now  made  into  a  thin  paste,  poured  over  the  first,  and 
moved  about,  readily  incorporates  with  it,  in  its  imperfectly  hardened  state.  Thus  an 
exact  mould  is  obtained  of  the  concave  surface  of  the  glass,  which  lies  about  three  quar- 
ters of  an  inch  thick  upon  it,  but  is  not  allowed  to  rise  above  its  outer  edge. 

The  mould,  being  perfectly  dried,  must  be  marked  with  a  point  of  coincidence  on  the 
glass,  in  order  to  permit  of  its  being  exactly  replaced  in  the  same  position,  after  it  has 
been  lifted  out.  The  mould  is  now  removed,  and  a  round  sheet  of  tin-foil  is  applied  to  it, 
so  large  that  an  inch  of  its  edge  may  project  beyond  the  plaster  all  round ;  this  border 
being  necessary  for  fixing  the  tin  to  the  contour  of  the  mould  by  pellets  of  white  wax 
soAened  a  little  with  some  Venice  turpentine.  Before  fixing  the  tin-foil,  however,  it 
must  be  properly  spread  over  the  mould,  so  as  to  remove  every  wrinkle;   which  the 


GLASS-MAKING. 


92i 


pliancy  of  the  foil  easily  admits  of,  by  uniform  and  well-directed  pressure  with  the 
fingers. 

The  glass  being  placed  in  the  hollow  bed  of  a  tight  sack  filled  with  fine  sand,  set  in  a 
well-jointed  box,  capable  of  retaining  quicksilver,  its  concave  surface  must  be  dusted 
with  sifled  wood-ashes,  or  Spanish  white  contained  in  a  small  cotton  bag,  and  then  well 
wiped  with  clean  linen  rags,  to  free  it  from  all  adhering  impurity,  and  particularly  the 
moisture  of  the  breath.  The  concavity  must  be  now  filled  with  quicksilver  to  the  very 
lip,  and  the  mould,  being  dipped  a  little  way  into  it,  is  withdrawn,  and  the  adhering 
mercury  is  spread  over  the  tin  with  a  soft  flannel  roll,  so  as  to  amalgamate  and  brighten 
its  whole  surface,  taking  every  precaution  against  breathing  on  it.  Whenever  this 
brightening  seems  complete,  the  mould  is  to  be  immersed,  not  vertically,  but  one  edge 
at  first,  and  thus  obliquely  downwards  till  the  centres  coincide ;  the  mercury  meanwhile 
being  slowly  displaced,  and  the  mark  on  the  mould  being  brought  finally  into  coinci- 
dence with  the  mark  on  the  glass.  The  mould  is  now  left  to  operate  by  its  own  weight, 
in  expelling  the  superfluous  mercury,  which  runs  out  upon  the  sand-bag  and  thence 
into  a  groove  in  the  bottom  of  the  box,  whence  it  overflows  by  a  spout  into  a  leather  bag 
of  reception.  After  half  an  hour's  repose,  the  whole  is  cautiously  inverted,  to  drain  -iff 
the  quicksilver  more  completely.  For  this  purpose,  a  box  like  the  first  is  provided 
with  a  central  support  rising  an  inch  above  its  edges;  the  upper  surface  of  the  support 
being  nearly  equal  in  diameter  to  that  of  the  mould.  Two  workmen  are  required  to 
execute  the  following  operation.  Each  steadies  the  mould  with  the  one  hand,  and  raises 
the  box  with  the  other,  taking  care  not  to  let  the  mould  be  deranged,  which  they  rest 
on  the  (convex)  support  of  the  second  box.  Before  inverting  the  first  apparatus,  how- 
ever, the  reception  bag  must  be  removed,  for  fear  of  spilling  its  mercury.  The  redun- 
dant quicksilver  now  drains  off;  and  if  the  weight  of  the  sandbag  is  not  thought  sufli- 
cient,  supplementary  weights  are  added  at  pleasure.  The  whole  is  left  in  this  position 
for  two  or  three  days.  Before  separating  the  mirror  from  its  mould,  tl^  border  of  tin- 
foil, fixed  to  it  with  wax,  must  be  pared  off"  with  a  knife.  Then  the  weight  and 
sandbag  being  removed,  the  glass  is  lifted  up  with  its  interior  coating  of  tin- 
amalgam. 

For  silvering  a  convex  surface. — A  concave  plaster  mould  is  made  on  the  convex  glassy 
and  their  points  of  coincidence  are  defined  by  marks.  This  mould  is  to  be  lined  with 
tinfoil,  with  the  precautions  above  described ;  and  the  tin  surface  being  first  brightened 
with  a  little  mercury,  the  mould  is  then  filled  with  the  liquid  metal.  The  glass  is  to  be 
well  cleaned,  and  immersed  in  the  quicksilver  bath,  which  will  expel  the  greater  part  of 
the  metal.  A  sandbag  is  now  to  be  laid  on  the  glass,  and  the  whole  is  to  be  inverted  as 
in  the  former  case  on  a  support ;  when  weights  are  to  be  applied  to  the  mould,  and  the 
mercury  is  left  to  drain  off  for  several  days. 

If  the  glass  be  of  large  dimensions,  30  or  40  inches,  for  example,  another  method  is 
adopted.  A  circular  frame  or  hollow  ring  of  wood  or  iron  is  prepared,  of  twice  the  diam- 
eter of  the  mirror,  supported  on  three  feet.  A  circular  piece  of  new  linen  cloth  of  close 
texture  is  cut  out,  of  equal  diameter  to  the  ring,  which  is  hemmed  stoutly  at  the  border, 
and  furnished  round  the  edge  with  a  row  of  small  holes,  for  lacing  the  cloth  to  the  ring, 
so  as  to  leave  no  folds  in  it,  but  without  bracing  it  so  tightly  as  to  deprive  it  of  the  elas- 
ticity necessary  for  making  it  into  a  mould.  This  apparatus  being  set  horizontally,  a 
leaf  of  tinfoil  is  spread  over  it,  of  sufficient  size  to  cover  the  surface  of  the  glass;  the 
tin  is  first  brightened  with  mercury,  and  then  as  much  of  the  liquid  metal  is  poured  on  as 
a  plane  mirror  requires.  The  convex  glass,  well  cleaned,  is  now  set  down  on  the  cloth, 
and  its  own  weight,  joined  to  some  additional  weights,  gradually  presses  down  the  cloth, 
and  causes  it  to  assume  the  form  of  the  glass  which  thus  comes  into  close  contact  with 
the  tin  submersed  under  the  quicksilver.  The  redundant  quicksilver  is  afterwards  drained 
off  by  inversion,  as  in  common  cases. 

The  following  recipe  has  been  given  for  silvering  the  inside  of  glass  globes.  Melt  in 
an  iron  ladle  or  a  crucible,  equal  parts  of  tin  and  lead,  adding  to  the  fused  alloy  one  part 
of  bruised  bismuth.  Stir  the  mixture  well,  and  pour  into  it  as  it  cools,  two  parts  of  dry 
mercury ;  agitating  anew  and  skimming  off  the  drossy  film  from  the  surface  of  the  amal- 
gam. The  inside  of  the  glass  globe,  being  freed  from  all  adhering  dust  and  humidity,  is 
to  be  gently  heated,  while  a  little  of  the  semi-fluid  amalgam  is  introduced.  The  liquidity 
being  increased  by  the  slight  degree  of  heat,  the  metallic  coating  is  applied  to  all  the 
points  of  the  glass,  by  turning  round  the  globe  in  every  direction,  but  so  slowly  as  to 
favor  the  adhesion  of  the  alloy.  This  silvering  is  not  so  substantial  as  that  of  plane  mir- 
rors :  but  the  form  of  the  vessel,  whether  a  globe,  an  ovoid,  or  a  cylinder,  conceals  or 
palliates  the  defects  by  counter  reflection  from  the  opposite  surfaces. 

Colored  Glasses  and  Artificial  Gems, — The  general  vitreous  body  preferred  by  Fon- 
tanieu  in  his  treatise  on  this  subject,  which  he  calls  the  Mayence  base,  is  prepared  in 
the  following  manner.  Eight  ounces  of  pure  rock-crystal  or  flint  in  powder,  mixed 
with  24  ounces  of  salt  of  tartar,  are  baked  and  left  to  cool.    This  is  afterwards  poured 


i 


922 


GLASS-MAZING. 


II 


whpn  .h  r  f^  ,''',!'**"\*"?  Hf*l^^  "^'^^  ^""^^  "'^"^  »<^'^  t'"  it  ceases  to  effervewe, 
when  the  fnt  IS   o  be  washed  till  the  water  comes  off  tasteless.     The  frit  is  now  dried 

Jr^^.l'?/ w  tJ"  n  .  Truf  ^"^  "^^^  ^^"^»  '^"^  ^^^  °^^^'"'^  i«  »«  be  levigated  and  elu- 
triaied  with  a  l.ttie  distilled  water.    An  ounce  of  calcined  borax  is  to  be  added  to  abour 

J2  ounces  of  the  preceding  mixture  in  a  dry  state,  the  whole  rubbed  together  in  a  porce 
Iain  mortar,  then  melted  in  a  clean  crucible,  and  poured  out  into  cold  water.     ThisVitre- 
ous  matter  must  be  dried,  and  melted  a  second  and  a  third  time,  always  in  a  new  crucible, 
th,i  I'JT      ""^^V"^  P«"[^«l  »"lo  cold  water  as  at  first,  taking  care  to  separate  the  lead 

lddP.r/nJ',h  ""f  •  ^u  •  ^'  ^^'i  ^JT  ^^""'^  t°  P°^^«^'  fi^«  ^--^chms  of  nitre  are  to  be 
added,  and  the  mixture  being  melted  for  the  last  time,  a  mass  of  crystal  will  be  found  in 
the  crucible  with  a  beautiful  lustre.    The  diamond  is  well  imitated  by  this  Mayence 

J^hi  nunT^'.r  IV.  rj^/'"  "^''"^  "y  ^"  obtained, according  to  M.  Fontanieu,  from 
eigh  ounces  of  white  lead,  two  ounces  of  powdered  borax,  half  a  grain  of  manginese. 
and  three  ounces  of  rock-crystal,  treated  as  above.  luan^anese, 

»Z«1T  k"^  !f^"^'^*''^^  ^T'  *'^  obtai'icd  from  metaUic  oxydes.  The  oriental  topaz  is 
prepared  by  adding  oxyde  of  antimony  to  the  base;  the  amethyst  from  man^aneseT with 
•  little  purple  precipitate  of  Cassius;  the  beryl  from  antimony  and  a  very  liitle^obl 

LiaT  ""w  P  ^  ^'""^"".^  S"'^  "P^'  ^T  ^«^»-«"-^r  (cWoride  of  silver)  ;  blue  stone  from 
cobalt.     See  Pastes  and  Pigments  ViTKiFiABLE.  *c  nvm 

The  following  are  recipes  for  making  the  different  kinds  of  glass. 

fc«I;.f "*!'/*  ^'7*— ^^  P«»"ds  of  dry  glauber  salts;  12  pounds  of  soaper  salts;  a  half 
bushel   of  waste  soap  ashes ;    56  pounds  of  sand ;   22  pounds  of  slass  skimmi^s     1 

gill's.  ^'''''  '"  ^^^''  ^^  P°""^'  °^  ^^^'-  This  mixture  affords  a  S  ir^en 
teiVo^nlHT"?'^!;'^^  sand,  100  parts;  kelp,  30  to  40;  lixiviated  wood  ashes,  from  160 

Spoken K'  im     7u  ^u  k'  ^^  '?  i^  P"'^'  P°"^^'^  '^^y^  «0  ^«  100  P^'-ts    c""et  or 

T„  ?in  K't  I  ,  ^^  K^'*^^  ^^  "'^^'  ^^^  proportion  of  kelp  may  be  diminished. 
crLienT  Jd  hHTl  "'"'  '"  '^^  neighborhood  of  Valenciennes,  an  unknown  in- 
gredient,  so  Id  by  a  Belgian,  was  employed,  which  he  called  spar.  This  was  discovered 
Vy  chemical  analysis  to  be  sulphate  of  baryta.  The  glass-makers  observed  that  [^ 
bottles  which  contained  some  of  this  substance  were  denser,  more  homogeneous  more 
fusible,  and  worked  more  kindly,  than  those  formed  of  the  common  materLr    When 

«o?i  ~.  K  ^  7"^^  ^^*^'  ^"^  exposed  m  a   proper  furnace,  vitrification 

read.ly  ensues,  and  the  glass  may  be  worked  a  little  under  a  cherry  red  hea  with  S 
much  ease  a»a  glass  of  lead  and  has  nearly  the  same  lustre.  Since  the  ord^nXu^ 
of  glass-makers  are  not  familiar  with  atomic  proportions,  they  should  have  recourse  to 
a  scientific  chemist,  to  guide  them  in  using  such  a  proportion  of  sulphatlofTryta  as 

Jm?Zt'^'t7n^tl^n^T^'  ^^r;-^^  P^'^"'^'  °^  ^"^  ?^^"^^'-  «^^^'-  10  poinds  of 
soaper  salts,  half  a  bushel  of  lixiviated  soap  waste;  50  pounds  of  sand-  2'>  oound^  nC 
glass  pot  skimmings ;  1  cwt.  of  broken  green  glass  ^       "*  "»  sanu ,  z^  pounds  of 

lJ^' tnZT  fu"r^^.  ^""'^f  ^""^  ^^"^^5  200  of  good  soda  ash;  33  of  lime;  from 
6    mt '/  !?  "^;  """^  f^^'' '  'J  "/  °^an?anese ;  100  of  broken  glass  ^ ' 

Je;'^5*:rf wwtetu^^'''°""'^^'p°^^^^^^  '^^^^^^^^^  ^^^'--^^^  io^--^ 

Rihillf' '".^i"^  ^''7^^'^  ^**'^^'  5  100  of  sand ;  20  of  chalk ;  and  2  of  saltpetre 
.iottuil^l^ntnl''"''"'''^'  ''"  of  «""<'-'-' i  10  of  saltpetre,  J  of  a«. 

Jle^ef^^^Vof'::'L^):' '''"'''  ■""'"""'  '""^ ''"^o  ■^""'^  "■»«'  iof-"- 

pei^etToWafgair"'  ""'=  '"  "' '"'  "'«^'  40  of  purified  pearl«h,  20of  s.1.. 

mL^^^i^'^.  "''  '•''*  *"'•!}  ""^^ '  ^°  "'■  ''^  '««>!  8  of  pearlash  purified;  2  of  «iu 
peire  j  a  litUe  aisenious  acid  and  manganese.  '^ ,  *  w  muh* 


GLASS-CUTTING. 


923 


A  seventh.  -100  of  sand ;  45  of  red  lead;  35  of  purified  pearlashes ;  1  of  manganese ; 
i  of  arsenious  acid. 

8.  Plate  glass. — Very  white  sand  300  parts ;  dry  purified  soda  100  parts ;  carbonate 
of  lime  43  parts;  manganese  1 ;  cullet  300. 

Another.— Finest  sand  720;  purified   soda  450;  quicklime  80  parts;  saltpelrre  25 
parts ;  cullet  425. 

A  little  borax  has  also  been  prescribed ;  much  of  it  communicates  an  exfoliating  pro- 
perty to  glass. 

Tabular  view  of  the  composition  of  several  kinds  of  Glass. 


Silica   . 

No.l. 
71-7 

No.  2. 
69-2 

No.  3. 

No.  4. 

No.  5. 

No.  6. 

No.  7. 

No.  8. 

No.  9.  1 

62-8 

69-2 

60-4 

53-55 

59-2 

51-93 

42-5 

Potash 

12-7 

15-8 

22-1 

8-0 

3-2 

5-48 

9-0 

\3-77 

11-7 

Soda     - 

2-5 

3  0 

3-0 

S.  pot. 

Lime    - 

10-3 

7-6 

12-5 

13-0 

20-7 

29-22 

0-6 

Alumina 

0-4 

1-2 

3-6 

10-4 

6-01 

1-8 

Magnesia 

20 

) 

0-6 

0-6 

Oxyde  of  iron 

0-3 

0-5 

V2.6 

1-6 

3-8 

5-74 

0-4 

—  manganese 

0-2 

J 

1-0 

1 

—  lead    - 

28-2 

33-28 

43-5  1 

Baryta 

0-9 

No.  1  is  a  very  beautiful  white  wine  glass  of  Neuwelt  in  Bohemia. 
No.  2.  Glass  lubes,  much  more  fusible  than  common  wine  glasses. 
No.  3.  Crown  glass  of  Bohemia. 
No.  4.  Green  glass,  for  medicinal  vials  and  retorts. 
No.  5.  Flask  glass  of  St.  Etienne,  for  which  some  heavy  spar  is  used. 
No.  6.  Glass  of  Sevres. 

No.  7.  London  glass  employed  for  chemical  and  physical  purposes. 
No.  8.  English  flint  glass. 
No.  9.  Guinand's  flint  glass. 

The  manufacture  of  Glass  beads  at  Murano  near  Venice,  is  most  ingeniously  simple. 
Tubes  of  glass  of  every  color  are  drawn  out  to  great  lengths  in  a  gallery  adjoining  the 
glass-house  pots,  in  the  same  way  as  the  more  moderate  lengths  of  thermomfeter  and 
barometer  tubes  are  drawn  in  our  glass-houses.  These  tubes  are  chopped  into  very  smaL 
pieces  of  nearly  uniform  length  on  the  upright  edge  of  a  fixed  chisel.  These  elementary 
cylinders,  being  then  put  in  a  heap  into  a  mixture  of  fine  sand  and  wood  ashes,  are  stirred 
about  with  an  iron  spatula  till  their  cavities  get  filled.  This  curious  mixture  is  now 
transferred  to  an  iron  pan  suspended  over  a  moderate  fire  and  continually  stirred  about 
as  before,  whereby  the  cylindrical  bits  assume  a  smooth  rounded  form  ;  so  that  when  re- 
moved from  the  fire  and  cleared  out  in  the  bore,  they  constitute  beads,  which  are  packed 
in  casks,  and  exported  in  prodigious  quantities  to  almost  every  country,  especially  to 
Africa  and  Spain. 

GLASS  CUTllNG  AND  GRINDING,  for  common  and  optical  purposes.  By  this 
*nechanical  process  the  surface  of  glass  may  be  modified  into  almost  any  ornamental  or 
useful  form. 

1.  The  grinding  of  crystal  ware.  This  kind  of  glass  is  best  adapted  to  receive 
polished  facets,  both  on  account  of  its  relative  softness,  and  its  higher  refractive  power, 
which  gives  lustre  to  its  surface.  The  cutting  shop  should  be  a  spacious  long  apart- 
ment, furnished  with  numerous  sky-lights,  having  the  grinding  and  polishing  lathes 
aiTanged  right  under  them,  which  are  set  in  motion  by  a  steam  engine  or  water-wheel  at 
(^25  _  one  end  of  the  building.      A  shaft  is  fixed  as  usual 

in  gallowses  along  the  ceiling ;  and  from  the  pulleys 
of  the  shaft,  bands  descend  to  turn  the  different 
lathes,  by  passing  round  the  driving  pulleys  near 
their  ends. 

The  turning  lathe  is  of  the  simplest  construction. 
Fig.  725,  D  is  an  iron  spindle  with  two  well-turned 
prolongations,  running  in  the  iron  puppets  a  a, 
between  two  concave  bushes  of  tin  or  type  metal, 
which  may  be  pressed  more  or  less  together  by  the 
thumb-screws  shown  in  the  figure.  These  two 
puppets  are  made  fast  to  the  wooden  support  b, 
which  is  attached  by  a  strong  screw  and  bolt  to  the 
longitudinal  beam  of  the  workshop  a.      e  is  the  fast  and  loose  pulley  for  putting  the 


924 


GLASS-CUTTING. 


GLASS-CUTTING. 


925 


1 


i 


lathe  into  and  out  of  gear  with  the  drivm?  shaft.  The  projecting  end  of  Itc  spindle  n 
furnished  with  a  hollow  head-piece,  into  which  the  rod  c  is  pushed  ti-ht.  This  rod  car- 
ries  the  cutting  or  grinding  disc  plate.  For  heavy  work,  this  rod  is  fixed  into  the  head 
by  a  screw.  When  a  conical  fit  is  preferred,  the  cone  is  covered  with  lead  to  increase 
the  friction. 

Upon  projecting  rods  or  spindles  of  that  kind  the  different  discs  for  cutting  the  elass 
are  made  fast.  Some  of  these  are  made  of  fine  sandstone  or  polishing  slate,  from  8  to  10 
inches  m  diameter,  and  from|  to  ^  inch  thick.  They  must  be  carefully  turned  and  polish- 
ed  at  the  lathe,  not  only  upon  their  rounded  but  upon  their  flat  face,  in  order  to  grind  and 
polish  m  their  turn  the  flat  and  curved  surfaces  of  glass  vessels.  Other  discs  of  the 
^me  diameter  but  only  |  of  an  inch  thick,  are  made  of  cast  tin  truly  turned,  and  erve 
for  pohshin-  the  vessels  previously  ground;  a  third  set  consist  of  sheet  iron  from  i.  to  | 
an  inch  thick,  and  12  inches  in  diameter,  and  are  destined  to  cut  grooves  in  glass  by  the 
aid  of  sand  and  water  Small  discs  of  xvelUhammered  copper  from  |  to  3  inches  in 
diameter,  whose  circumference  is  sometimes  flat,  and  sometimes  concave  or  convex,  serve 
to  make  all  sorts  of  delmealions  upon  glass  by  means  of  emery  and  oil.  Lastly,  there 
are  rods  of  copper  or  brass  furnished  with  small  hemispheres  from  i  to  J  of  an  inch  in 
diameter,  to  excavate  round  hollows  in  glass.  Wooden  discs  are  also  employed  for  polish- 
m^  made  of  white  wood  cut  across  the  grain,  as  also  of  cork. 

The  culling  of  deep  indentations,  and  of  grooves,  is  usually  performed  by  the  iron 
disc,  with  sand  and  water,  which  are  allowed  constantly  to  trickle  down  from  a  wo<x^en 
hopper  placed  ri^ht  over  it,  and  furnished  with  a  wooden  stopple  or  plug  at  The  a^e^  to 
regulate  by  its  greater  or  less  looseness  the  flow  of  the  grinding  materills.  The  same 
ettect  may  be  produced  by  using  buckets  as  shown  in  fig.  126.  The 
sand  which  IS  contained  in  the  bucket  k,  above  the  lathe,  has  a  spigot 
and  faucet  inserted  near  its  bottom,  and  is  supplied  with  a  stream  of 
water  from  the  stopcock  in  the  vessel  g,  which,  together  running  down 
the  inclined  board,  are  conducted  to  the  periphery  of  the  disc  as'shown 
in  the  figure,  to  whose  lowest  point  the  glass  vessel  is  applied  with 
pressure  by  the  hand.  The  sand  and  water  are  afterwards  collected  in 
the  tub  H.  Finer  markings,  which  are  to  remain  without  lustre,  are 
made  with  the  small  copper  discs,  emery,  and  oil.  The  polishing  is 
eflecled  by  the  edge  of  the  tin  disc,  which  is  from  time  to  time  moisten- 
ed with  putty  (while  oxyde  of  tin)  and  water.  The  wooden  disc  is 
also  employed  for  this  purpose  with  putty,  colcothar,  or  washed  tripoli. 
i<or  fine  delineations,  the  glass  is  first  traced  over  with  some  colored 
varnish,  to  guide  the  hand  of  the  cutter. 

In  grinding  and  facetting  crystal  glass,  the  deep  grooves  are  first 

cut,  for  example  the  cross  lines,  with  the  iron  disc  and  rounded  ed*>e, 

.«^  io  •    u      ■    ^-  ^  "^^"^  ®,C!*"^  ^"'^  ^^ater.     That  disc  is  one  sixth  of  an  inch  thfck 

«r  iJc  •  "^  ^'  ""  ^'*™^^^''-  ^^'^^  ^"''^^^''  ^"«"  ^^^^  ^^""^  ^«lf  «"  inch  thick,  and  more 
or  less  in  diameter  according  to  the  curvature  of  the  surface,  the  grooves  may  be  widen- 

t«t.r  on  f^.K*""^  ?•  f  SP^rV'  T^^  ^^  "^^^  smoothed  down  with  the  sandstone  disc  and 
water,  and  then  polished  with  the  wooden  disc  about  half  an  inch  thick,  to  whose  edge 
^e  workman  applies,  from  lime  to  time,  a  bag  of  fine  linen  containing  some  ground  pumice 
moistened  with  water  When  the  cork  or  wooden  di.c  edged  with  hat  felt  is  used  fw 
polishing,  putty  or  colcothar  is  applied  to  it.  The  above  several  processes  in  a  lar-e 
manufactory  are  usually  committed  to  several  workmen  on  the  principle  of  the  division 

o^['  ^°  ^^^  ^^^^  ""^y  become  expert  in  his  department. 
.«r       I.  ^""'"'^^''f  "*/  ^^'^'^^^  glasses.-The  glasses  intended  for  optical  purposes,  being 
llclTnllr^T'^'  "'"  called  lenses;  and  are  used  either  as  simple  magnifiers  and  Tpec! 
InJ I'rh         ^^^^'^^^^^  «"^  microscopes.     The  curvature  is  always  a  portion  of  a  sphere, 
and  either  convex  or  concave.      This  form  ensures  the  convergence  or  divergence  of  the 

Zllf  ^'^^''   '^''  P"''  '^'^""^^  '^^°*'  *^  '^'  P«"«^i"?  does   the   brightness  of  the 

To ^^"5  ?"?K '"^  ""^  ^^^  '^"'^'  *'  performed  in  brass  moulds,  either  concave  or  convex, 
hinfnrv.  T'  """^^^^r"  "'  ^^^^  ^^'"^  ^"  ^^*^  ^^^^^^  ?  «"d  may  be  worked  either  b^ 
?.^ir  ^  Tfu  T'^\u  "^-^^"r^  '^  ^'''  ^"^  °"^  °»l  0^  *>''=^^s  «r  copper  plate  to  suit  ihj 
cu  vature  of  the  lens,  the  circular  arc  being  traced  by  a  pair  of  compasses.  In  this  way 
both  a  convex  and  concave  circular  gauge  are  obtained.  To  these  gauges  the  brass 
moulds  are  turned.  Sometimes,  also,  lead  moulds  are  used.  After  the  two  moulds  are 
made,  they  are  ground  face  to  face  with  fine  emery 

,1  Iv^jIZlo''^  ^iT"'  il  now  roughed  into  a  circukr  form  by  a  pair  of  pincers,  leaving 
In!  H  "• '  ^^",  /^^  ^""f  hed  lens  ought  to  be,  and  then  smoothed  round  upon  the 

«onedisc  or  in  an  old  mould  with  emery  and  water,  and  is  next  made  fast  toV  hold- 
«Ll;Ur  ■  If-  *^""f'«'^,/'^  ^J^°"°d  ^'^^l  plate  having  a  screw  in  its  back  ;  and  is  somewhat 
smaller  in  diameter  than  the  lens,  and  two  thirds  as  thick.    This  as  turned  concave  upon 


li 


the  lathe,  and  then  attached  to  the  piece  of  glass  by  drops  of  pitch  applied  to  several 
points  of  its  surface,  taking  care,  while  the  pilch  is  warm,  that  the  centre  of  the  glass 
coincides  with  the  centre  of  the  brass  plate.  This  serves  not  merely  as  a  holdfast,  by 
enabling  a  person  to  seize  its  edge  with  the  fingers,  but  it  prevents  the  glass  from  bend- 
ing by  the  necessary  pressure  in  grinding. 
.  The  glass  must  now  be  ground  with  coarse  emery  upon  its  appropriate  mould,  whethe" 
convex  or  concave,  the  entery  being  all  the  time  kept  moist  with  water.  To  prevent  the 
heat  of  the  hand  from  affecting  the  glass,  a  rod  for  holding  the  brass  platens  screwed  to 
its%ack.  For  every  six  turns  of  circular  motion,  it  must  receive  two  or  three  rubs  across 
the  diameier  in  diflerent  directions,  and  so  on  alternately.  The  middle  point  of  the  glass 
must  never  pass  beyond  the  edge  of  the  mould;  nor  should  strong  pressure  be  at  any 
lime  a^iplied.  Whenever  the  glass  has  assumed  the  shape  of  the  mould,  and  touches  it 
in  every  point,  the  coarse  emery  must  be  washed  away,  finer  be  substituted  in  its  place, 
and  the  grinding  he  continued  as  before,  till  all  the  scratches  disappear,  and  a  uniform 
dead  surface  be  produced.  A  commencement  of  polishing  is  now  to  be  given  with  pum- 
ice stone  powder.  During  all  this  time  the  convex  mould  should  be  occasionally  worked 
in  the  concave,  in  order  that  both  may  preserve  their  correspondence  of  shape  between 
them.  After  the  one  surface  has  been  thus  finished,  the  glass  must  be  turned  over,  and 
treated  in  the  same  way  upon  the  other  side. 

Both  surfaces  are  now  to  be  polished.  With  this  view  equal  parts  of  pitch  and  rosin 
must  be  melted  tosether,  and  strained  through  a  cloth  to  separate  all  impurities.  The 
concave  mould  is  next  to  be  heated,  and  covered  with  that  mixture  in  a  fluid  state  to  the 
thickness  uniformly  of  one  quarter  of  an  inch.  The  cold  convex  mould  is  now  to  be 
pressed  down  into  the  yielding  pilch,  its  surface  being  quite  clean  and  dry,  in  order  to 
give  the  pilch  the  exact  form  of  the  ground  lens ;  and  both  are  to  be  plunged  into  cold 
water  till  they  be  chilled.  This  pilch  impression  is  now  the  mould  upon  which  the 
glass  is  to  be  polished,  according  to  the  methods  above  described,  with  finely  washed 
colcothar  and  water,  till  the  surface  become  perfectly  clear  and  brilliant.  To  prevent  the 
pilch  from  changing  its  figure  by  the  friction,  cross  lines  must  be  cut  in  it  about  |an  inch 
asunder,  and  l-12lh  of  an  inch  broad  and  deep.  These  grooves  remove  all  the  super- 
fluous parts  of  the  polishing  powder,  and  tend  to  preserve  the  polishing  surface  of  the 
pitch  clean  and  unaltered.  No  additional  colcothar  after  the  first  is  required  in  this  part 
of  the  process;  but  only  a  drop  of  water  from  time  to  time.  The  pitch  gets  warm  as  the 
polishing  advances,  and  renders  the  friction  more  laborious  from  the  adhesion  between 
the  surfaces.  No  interruption  must  now  be  suflfered  in  the  work,  nor  must  either  water 
or  colcothar  be  added ;  but  should  the  pitch  become  too  adhesive,  it  must  be  merely 
breathed  upon,  till  the  polish  be  complete.  The  nearer  the  lens  is  brought  to  a  true  and 
fine  surface  in  the  first  grinding,  the  better  and  more  easy  does  the  polishing  become.  It 
should  never  be  submitted  to  this  process  with  any  scratches  perceptible  in  it,  even 
when  examined  by  a  magnifier. 

As  to  small  lenses  and  spectacle  eyes,  several  are  ground  and  polished  together  in  a 
mould  about  6  inches  in  diameter,  made  fast  to  a  stiflening  plate  of  brass  or  iron  of  a 
shape  corresponding  with  the  mould.  The  pieces  of  glass  are  affixed  by  means  of  drops 
of  pitch,  as  above  described,  to  the  mould,  close  to  each  other,  and  are  then  all  treated  as 
if  they  formed  but  one  large  lens.  Plane  glasses  are  ground  upon  a  surface  of  pilch 
rendered  plane  by  the  pressure  of  a  piece  of  plate  glass  upon  it  in  its  softened  state. 

Lenses  are  also  ground  and  polished  by  means  of  machinery,  into  the  details  of  which 
the  limits  of  this  work  will  not  allow  me  to  enter. 

Glass  in  the  Exhibition. — So  far  as  may  be  inferred,  from  the  analysis  of  ordinary 
commercial  samples  of  window-glass,  this  substance  has  not  only  a  verv  Variable  compo- 
sition, but,  worse  than  this,  is  out  of  all  keeping  with  anything  like  (lefiiiite  proportioa 
That  it  should  be  full  of  strise,  and,  therefore,  refract  the  rays  of  light  equally,  as  it  does, 
so  as  to  produce  the  most  hideous  appearances  of  distortion,  is  a  mere  natural  consequence 
of  its  mechanical  composition,  which  might,  and  must  one  day,  be  corrected  ;  but  that  whole 
nations  should  have  come  to  view  this  defect  as  an  unavoidable  peculiarity,  is  precisely 
one  of  those  surprising  facts  which  demonstrate  the  influence  of  habit  over  the  powers  of 
the  mind,  and  show  how  easily  human  reason  can  reconcile  itself  to  the  most  gross  incon- 
sistencies. If  window-glass  had  one  uniform  atomic  composition,  the  tendency  to  form 
these  striae  would  nowhere  exist  in  excess;  and,  therefore,  their  production  would 
diminish  as  the  skill  of  the  workmen  increased ;  but,  with  the  present  variable  com- 
pound, the  glass  stretches  unequally  in  ditferent  parts,  by  an  equal  application  of  force, 
and,  in  spite  of  human  skill,  presents  a  result  alternately  thick  or  thin,  as  accident 
determines.  That  these  striae  have  not  the  same  composition  as  the  parts  surrounding 
them  is  very  obvious,  from  the  circumstance  that,  if  striated  glass  be  cut  to  an  uniform 
thickness,  and  polished  on  both  sides,  the  optical  defects  remain  but  little  changed,  and 
occasionally  they  are  fouml  to  be  increased.  Again  it  is  known,  that  the  more 
complex  the  composition  of  any  glass  may  be,  the  greater  the  liability  to  this  striated 


526 


GLASS. 


GLASS. 


927 


8tructure,-of  which  flint  ?la«s  offers  an  opposite  illustration  •  for  here  in  addition  in 

^r:vi[v'nr--rTP'r,"^'^  ^^^'^  '^'  '^''^'^^^  ^'^^  i«  superadded     No\"  the  sZifi^ 
ilZ^  "f  ^'I'^'-^te  of  lead  is  verj;  high  compared  with  that  of  silicate  of  soda  Sh 

wit  in.;  n^'  r.^™P^^^^^  ^°  *^"  exact  quantity  to  form  a  chemical  SmbKon 
Inlu-  .1?  K^'^r*^'^  ^^'"^  mechanical  mixtur'e  is  produced  of  very  difft rent 
densities  throughout ;  and  the  product,  under  the  action  of  light,  displays^poLanentlv 

mhed   to^Mhp?  ir  ''^"  ^^^"  «y^"P  «"^  ^^*^'?«'-  ^l««»'ol  aSd  water  afe 

rifr!  r  ^  r  n  •  .*^^^ J' -^  '^y'  ^  ^^"^«  «f  cu'-^-ed  lines  are  formed  by  the  uneoual 
lefract.on  of  the  two  fluids,  which  entirely  disappear,  so  soon  as  perfect  admTxtTe^h^ 

^ffecL^'th'p  nt"^''^  '■'"""^"  '^''  "^^^  «^  «•" 'g^^^«'  ^'^^  the^utter  imp'S 
nS  bi^  necessary  union  between  its  various  parts.      Although,  however  th  sJan- 

easoLH  "^^^*^^"if  7'  y^\^  a  chemical  way,  nature  performs  such  operations  whh 
ease  and  unerring  fidelity.  The  French  chemist,  Berthier  long  ago  proved  that  nTanv 
neutral  salts  combine  together  by  fusion  in  atomic  proportfons^anrform  tw  and 
atom  fo^nT''""'^';  ^f '  ''^^"^*'  «f  P^'*'-^^^^  ^"d  carbonate  of  soda  wT.en  mixed 
Si  f  fu  ;  ""'*^  .^"?  P'^""^  ^  compound  more  easy  of  fusion  than  The  mS 
fusible  of  the  two  :-sim.larly,  either  of  these  carbonates  w-ill   act  with  carbonatHf 

^nA,{-Kl  "*'  f  r''"''*'  \"^  ^?^'"'  ^«"^-«P«^  ^"d  «»lph^te  of  lime,  two  r oSablv 
infusible   substances,  when  mixed,  melt  readily,  at   a  low  red  heat  inM  «  fl.,:  i  i  •/ 

and  transparent  as  water.     It  i^  useless  to -Multiply  ^xallefoA^ 
sands  exist;  and  the  alkaline  and  earthy  silicates  fomn7e?ception  to  thi^.l^^^^^^^ 
universal   rule.     A  mixture  of  silicate  of  potash  and  s^cate  of  soTTni    v'  '* 

ratios,  fuse  much  more  readily  than  eitherof  tLTatne      But  n^^^^  "^"'"" 

attempt  to  fuse  these  two  bodies  together,  in  anrier  p"  ttionThIn  tharKl'/h 
they  are  naturally  disposed  to  combine —.ay  that  thp  IKJ Tf  i  •  •  '"  ^'"^^^ 
then  the  silicate  of  potLh  would  unite  wWeLctiv.u^^^^^^  \'  "J  'T''' 

sC^trof'LT^'Td^ '''''''  ^^'"p^""^  abovr:;!L"oT:T^^^^^^^^  \t  trii  /t -b : 

'  miv  L  5l  *w  'n  excess,  would  form  a  kind  of  network  througLut  tL  ^asl 
t'  n?av  be  said,  that  a  higher  heat  would  overcome  this  diflicultv  hv  ihnr  Zu 
hqui^Mng  the  silicate  of  soda;  and  this  is  really  the  plarnow  use7'wirh  t  at  iel^ 
but  independent  of  the  fact,  that  the  mixed  silicate  of  potash  and  soda  would  X' 
undergo  a  corresponding  liquefaction,  and,  therefore,  favour  the  separation  of  ThT  silica  e 
of  soda;  yet,  as  chemical  union  is  impossible,  from  the  very  condition.  !rn?J 
penment.  even  the  most  perfect  mechanical  mixture,  under  th^  great st  ad v^nttes'of 

fu^ed  together,  mto,  probably,  one  of  the  most  antagonistic  componmls  that  could  ^ 
conceived,  refracting  and  dispersing  the  rav  of  ii^ht  in  fiftv  ,llC     J.""*..™"!"  •» 

5-\,'«?"    »*'pted   into  several  continental     angrefNererlM^^^^        ^T^A"'^ 

Ar^ley.  Pellatt  and  Co.  is  a  :„:tm'^re'„t"fo  ^Snst'^h^tl  .^  sl?c7tf  SLt^lT^": 
and  the  mere  mquirer  into  this  branch  of  manufacture  need  go  no  fartSr  ,„  it  a  neZ^ 
Z„  IJ'i^'?  "'  "•?  T**"'  ."l"'  """  ^  »'='"'=™''  t>y  "-e  manipulation  „?  thil  rn^a lerifl   TOe 

host  of  others  the  effect  is  DositivplvH^r'  7  '  ^^  """^  Summerfield,  and  a 
cover  the  faults  oVr^rlcfirnr^e^veli'tt"^,:^^^^^^^  -«^--t  to 

ance  ;  and  indeed,  the  glass  koh-i-noor  of  Mr  Pell  at  t  di'pHved  in  hi'  ^  ^'^'"^  ""-^^rZ: 
substituted  for  the  real  gem,  shown  in  the  main  avemirw  Zft  thl  1  ^I'^i  "V^?*.^ 
tion  on  the  part  of  the  million,  or  anv  great  los."of  br  li;rc?to  Jp  '  o7  "r  a  '''^''■ 
«o  perfect  is  the  imitation.    Is  it  not  tLo  to  be  ^X^rZ:r.^^l^'::^:S^ 


mingling  its  constituents  together?  But  we  must  turn  from  this  glittering  assortment 
and  descend  to  a  lower  level,  where  we  shall  find  Great  Britain  in  (ii'Sgrace,  and  suffer- 
ing severely  from  comparison  with  a  rival  inferior  in  capital  and  natural  resources,  but 


England  far  into  the  shade.     The  prodi „.  _,. ^„...  „.„„^.  .„„.,^  „, 

the  Exhibition ;  they  have  no  competitors ;  and  we  are  in  a  condition  to  prove  that 
chemistry  has  done  this.  Tlie  plate-glass  of  Montluyon,  too,  adds  to  the  defeat.  In  examin- 
ing the  refractive  aberrations  of  a  mirror,  the  spectator  will  find  his  task  facilitated  by 
standing  so  that  the  rays  of  light  from  any  geometrically  shaped  body  fjill  upon  the  glass, 
at  an  angle  of  25°  ;  when,  of  course,  they  will  be  reflected  towards  his  eye  at  the  same 
angle.  Now  gazing  intently  on  the  figure  in  question— and  which,  in  the  Exhibition,  may 
be  one  of  the  parallelograms  formed  by  the  rafters  of  the  roof,  let  him  gently  move  his 
head  from  one  side  to  the  other.  If  the  glass  be  of  English  manufacture,  he  will  imme- 
diately perceive  a  tumultuous  moyement  in  the  lines  of  the  figure,  as  if  this  were  subjected 
to  an  undulatory  action, — the  lines,  before  straight  and  parallel,  become  crooked  and  con- 
vergent in  places,  and  minute  objects  lose  entirely  their  outline  and  definition.  In 
the  case  of  the  St.  Gobain  glass,  shown  in  the  French  department,  not))ing  of  this  kind 
takes  place.  As  it  can  serve  no  good  purpose  to  dwell  upon  each  individual  example 
of  imperfection,  we  refrain  from  entering  further  into  the  comparative  merits  of  the 
British  exhibitors.  They  are  all  surpassed  by  the  French  makers,  both  in  respect  to 
uniformity  of  composition  and  fineness  of  polish.  The  St.  Gobain  Company  having  had 
the  good  sense  to  place  a  number  of  small  samples  of  their  glass  for  the  acceptance  of 
those  visitors  who  may  feel  an  interest  in  the  manufacture,  we  have  selected  and  analyzed 
one  of  these  little  squares,  and  shall  presently  detail  the  result ;  but  our  object  in  allu- 
ding to  them  here  is,  that  glass-makers  themselves  may  procure  one  of  these  specimens 
and  contrast  it  with  a  like  morsel  of  English  plate-glass.  If  the  two  be  laid  side  by  sJile 
upon  any  moderately  light-coloured  ground,  and  a  distant  object,  as  a  chimney  for  ex- 
ample, be  subjected  to  reflection,  it  will  be  found,  that  whilst  the  French  glass  gives  a 
clear  sharp  outline,  the  English  reflects  either  two  or  more  images  in  a  hazv  and  imper- 
fect manner.  There  is  no  getting  over  this  fact ;  and  therefore  improvement  is  imperative. 
The  mode  of  making  plate-glass  being,  so  to  say,  identical  in  the  two  countries,  the  dif- 
ference here  remarked  can  arise  from  nothing  else  than  a  difference  in  composition. 

In  France,  as  in  England,  the  ingredients  are  mixed  wnth  some  care,  and  introduced 
into  a  crucible,  heated  by  a  powerful  furnace.  These  ingredients  are  sand  or  silica, 
carbonate  of  soda,  and  carbonate  of  lime,  with  perhaps  a  little  ground  felspar  in  some 
cases.  The  carbonate  of  soda  is  first  attacked  by  the  silica,  and  its  carbonic  acid  driven 
off,  whilst  the  remaining  silica  and  carbonate  of  lime  becomes  imbedded  in  the  vitrifving 
mass.  As  the  heat  increases,  a  more  perfect  fusion  takes  place  ;  and  then  tke  carbonic 
acid  of  the  carbonate  of  lime  makes  its  way  through  the  fused  materials  by  which  they 
are  mechanically  mingled  together  during  the  effervescence,  which  is  technically  termed 
the  "  boil  ;"^  and,  provided  no  after  separation  ensues  from  the  process  of  "  settling,"  the 
whole  crucible  or  "  pot"  of  glass  will  have  a  uniform  composition,  But,  as  we  have  seen, 
this  depends  altogether  upon  the  relative  proportion  of  the  materials  towards  each  other] 
for  an  excess  of  either  one  or  other  of  the  bases  will  destroy  the  homogeneous  character 
of  the  whole,  and  introduce  a  plexus  of  stri.e.  Now  the  plate-glass^'of  St.  Gobain  is 
almost  exactly  an  atomic  compound,  and  consists  of  one  atom  of  tlie  trisilicate  of  soda 
and  one  atom  of  the  trisilicate  of  lime,  with  a  small  percentage  of  alumina.  The  union 
is  therefore  complete ;  and  when  it  is  remembered  that  the  celebrated  French  chemist 
Gay  Lussac,  was  regularly  employed  as  an  adviser  to  this  company,  and  that  his  son' ' 
M.  Jules  Lussac,  retains  that  appointment  to  this  day,  it  is  not  very'surprisino-  that  our 
manufacturers  are  defeated  in  the  article  of  plate-glass.  Science  must  ever  take  the  lead 
of  prejudice  and  custom. 

The  examination  of  English  plate-glass  fully  corroborates  the  general  result  deduced 
from  the  action  of  light.  There  is  no  approach  to  an  atomic  arrangement.  The 
principal  constituent  is  trisilicate  of  soda,  but  variable  quantities  of  lime,  alumina, 
and  even  magnesia,  exist  in  it.  Potash  is  sometimes  present,  and  oxide  of  iron  is 
invariably  so;  but  in  not  one  single  instance,  out  of  17  samples  examined  with  great 
care,  could  so  much  as  a  surmise  of  the  doctrine  of  combining  proportions  be  gathered 
from  the  result  of  the  analyses.  Similarly  fruitless  was  a  research  instituted  upon  flint- 
glass,  both  British  and  foreign.  Of  35  samples  analyzed,  no  satisfactory  evidence 
could  be  adduced  to  favour  the  opinion  that  science  had  been  a  helpmate  to  industrj-, 
or  was  at  all  concerned  in  this  branch  of  manufacture.  There  are.  however,  some 
points  of  vast  interest  associated  with  the  practical  working  out  of  tliis  matter.  Potash 
la  known  to  give  a  more  brilliant  and  harder  glass  than  soda,  and  alumina  seems  to  tend 
in  the  sanoe  direction.  The  Bohemian  glass,  so  celebrated  throughout  Europe,  is  a 
glass  of  this  description,  and  contains  silicate  of  alumina,  silicate  of  lime,  and  silicate  of 


'  t 


928 


GLASS. 


potash,  but  not  in  chemical  proportions.    This  (^lass  is  tht^rt^fnra  utriat^A  «  ». 

fefinn  w    •  '";r^""i  *^^*  .softness  and  liability  to  receive  scratches  which  are  so 
it  has  been  demonstrated  th.5,  durinV^itrmcTtit't'e  siUci    It  d  1  t^s'fo ttt'    Z 

c^T  of  r  'T  ^^'""'Vl  "^  -^^^0  o^^^^^^^^^^  poKo  ^oYpnll^b^e  or 

tW  ;i       K    ?!"^«"^^«  'f  b^'-yta,  and  112  of  oxide  of  lead  or  li  har^^e    ^SupZe    Ln 
tha   the  object  13  to  employ  carbonate  of  baryta  for  the  first  time  here  6  aTms  nr  o7A 

carbonate  of  baryta,  may  be  mixed  and  fused  together  with  every  Drosnect  of  nhMJnJn^ 
a  good  resul  ;  or  9  atoms  of  silica,  1  of  carbonate  of  potash  1  TSnato  of  3 
and  1  of  carbonate  of  baryta,  might  be  tried   without  fplrnf  f.^i    carbonate  of  soda, 

orr'ad!l"r-^^T'  V'  «V^'^T^''^  ^^^oZLT'^T^^^^^^ 

or  an  additional  atom  of  trisilicate  of  potash  might  be  used      For  manv  /I.rs  n^t 

M.  Dumas,  now,  perhaps,  the  first  chemist  in  France,  has  been  in  the  habif^?fl^     ' 

maw  .ho  wiu  adSt  thit  hi,  L  isTurf:;rh',^„  ^f  s.ioll\'„7i:a^;?;:i'-/4t 

To  assist  as  far  as  we  can  in  the  attainment  of  this  end  we  shall  nrnrPPrl  ♦«  .i       -u 
a  simple  means  for  the  analysis  of  glass,  which  will  enab  e  Ty  persotrnos'e  s^^^^ 
very  trifling  chemical  skill,  to  detennine  the  composition  oTL^^grJen^^^^^^^^^^^ 
in  a  comparatiyely  short  time.     From  the  nature  of  the  material^    LS  neoestTv 
to  divide  the  analysis  into  two  distinct  portions;  one  of  which  has  fortTnhriff^ 
estimation  of  its  alkaline  ingredients,  the  other  tha   of  the  eaT  hy  metall  c  an,fe'   *^^ 
matters      Having  heated  a  sufficient  quantity  of  the  sample  in  ^u^ 

must  be  suddenly  thrown,  whilst  still  hot,  into  a  basin  containing  cold  water    In  thi  wlv 
^ecomes  cracked  and  flawed  in  all  directions,  so  as  to  favour  its  reduction  into  powder 
When  dry  it  must,  therefore,  be  carefully  ground  in  an  agate  or  steel  mo  ?ar  Sit 
has  the  appearance  of  fine  flour.     Nor  is  it  a  matter  of  indifference  whXr  this  tales 
place  m  contact  with  water  or  not;  for  glass,  in  this  extreme  state  of  comminution 
readily  gives  up  a  part  of  its  alkali  to  water;  and  hence,  if  ground  in  the  pTeTence  of 
that  fluid,  the  resulting  analysis  would. prove  incorrect.     But  we  will  sunnote  fhnf  I 
quantity  of  fine  y  powdered  glass  has  been  obtained  as  above  indicated  anTtTe.ntwn? 
of  Its  alkah  IS  desired  ;  then  weigh  out  100  grains  of  the  glas^ndlreful  y  mix  wit^^ 
t  200  grains  of  pure  fluor  spar  in  a  similarly  powdered  rondit  on      PUoTtL  1^  T 
in  a  plat  num  or  leaden  vess&  and  pour  ovei^  ft  500  ^rks  of  Zng  ^^^^^^^ 
stirring  the  whole  well  together  with  a  silver  spoon     but  taking  carP  not  t  f         '"" 
any  portion  of  the  materials.      Xext,  apply  a   'eat  of  abo  f  ll°  F^hr^n^^^ 
process  draws  to  a  conclusion,  this  may  be  raised  as  high  as  SOO^.     When  ill  etllutn 
of  gaseous  fumes  has  ceased,  water  may  be  poured  on  the  residuary  ma-^s  to  thlexte 
of  four  or  five  ounces,  and  th6  mixture  thrown  on  a  filter      After  the  rle^r  fl?,:  i  i 
pa.ed  through,  a  little  more  water  must  be  added  to  the  filterso  a  'L  Ith     u    Z 
whole  of  the  soluble  matter;  these  washings  being  joined  to  the  original  clear  fl,    J 
which  consists  of  su  phate  of  soda  or  potash,  or  bSth,  with  a  quanti  y  "?  s"  plmte     f 
lime,  and  perhaps  also  of  magnesia  and  alumina.    To  this  an  excess  of  carbo     te  of 
ammonia  must  now  be  added,  to  admit  of   the  ^enaratinn  nf  tho  LJil  1    .    • 

effected  by  filtration.  The  clear  solution  is  next  boilKTu  t^o  d^^e  ^n^d  S^e  fduf 
IS  heated  red-hot  for  a  minute  or  wo.  This  residue  is  the  soda  oV  potash  o  both  for! 
L?ppU""^^-?^  '"-^S?  grains  of  the  glass,  but  now  united  to  sulphuric  ach i.  Havt^ 
ascertained  its  weight,  the  relative  proportions  of  potash  and  sola  may  be  found  b? 
testing  Its  content  of  sulphuric  acid  with  a  barytic  solution,  and  calculating  te  Lit 
by  the  well-known  Archimedean  equation;  or  by  dissolving  the  mixed  J t  in  a  snia  1 
quantity  of  water,  and,  after  adding  an  excess  of  tartaric  \ci<l,  leaving  the  whole  for  a 
iew  hours  covered  up  m  a  cool  place.     Almost  the  whole  of  th^  potash  will  Ie|^arate  in 


GLASS. 


929 


this  way  as  bitartrate  of  potash.  The  quantity  of  alkali  may  be  determined  from  the 
atomic  constitution  of  the  alkaline  salts.  Thus,  supposing  the  dry  residue  altogether  com- 
posed of  sulphate  of  soda,  then  as  72  grains  of  it  indicate  32  of  pure  soda,  the  result  may 
be  obtained  by  the  rule  of  proportion.  The  amount  of  alkali  being  known,  another  jwr- 
tion  of  the  powdered  glass  must  be  employed  for  ascertaining  the  remainder  of  the 
ingredients.     That  is  to  say,  100  grains  of  the  sample  must  be  mixed  with  200  grains  of 

f)ure  potash,  and  the  whole  fused  together  in  a  silver  crucible,  at  a  red  heat,  until  perfect 
iquefaction  ensues,  when  the  crucible  and  its  contents  may  be  withdrawn  from  the  fire, 
and,  as  soon  as  cool  enough,  boiled  in  half-a-pint  of  pure  water,  so  as  thoroughly  to  dis- 
solve the  fused  mass  from  the  crucible.  An  excess  of  nitric  acid  being  poured  into  the 
solution,  the  mixture  is  then  evaporated  to  dryness,  by  which  means  the  silicic  acid  is 
rendered  insoluble ;  consequently,  on  the  application  of  water,  this  remains,  and  may  be 
dried  and  weighed,  whilst  the  lime,  alumina,  and  lead  of  the  glass  may  be  separated 
from  the  soluble  portion  by  the  addition,  first,  of  sulphuretted  hydrogen,  which 
separates  the  lead,  then  of  ammonia,  which  throws  down  the  alumina,  and,  next,  by 
pouring  in  carbonate  of  ammonia,  which  precipitates  the  lime  as  a  carbonate.  Thus, 
therefore,  the  alkaline  matters  are  found  by  one  process,  and  the  silica,  earthy,  and 
metallic  constituents  by  another,  both  of  which  may  be  conducted  at  the  same  time.  It 
has  been  recommended  to  employ  carbonate  of  baryta  in  the  analysis  of  glass ;  but  the 
high  temperature  required  with  this  substance  dissipates  a  portion  of  the  alkaline  compo- 
nents, and  thus  leads  to  serious  errors.  Even  mere  fusion  in  a  glass  furnace  expels 
soda  from  glass,  and  renders  it  more  and  more  infusible ;  but  this  expulsion  is  much 
favoured  by  the  presence  of  baryta.  The  above  method  of  analyzing  glass  is,  therefore, 
to  be  preferred  to  the  baryta  plan,  by  individuals  not  habitually  engaged  in  manipulative 
chemistry.  Until  manufacturers  adopt  the  custom  of  examining  every  specimen 
of  glass  they  make,  the  chances  of  improvement  are  extremely  limited  ;  for  success 
one  day  is  constantly  followed  by  failure  in  another,  without  any  means  of  check- 
ing or  controlling  the  manufacture.  It  is  generally  said  that  the  best  glass  is  made 
during  cold  weather,  as  at  this  time  the  furnaces  give  most  heat,  from  the  increased 
activity  of  the  draught,  through  the  augmented  barometrical*  pressure.  The  assertion 
itself  is  most  likely  true  ;  but  the  explanation  of  its  cause  leaves  much  to  be  elucidated, 
even  if  a  higher  heat  prevails  at  the  period  in  q^uestion.  Admitting  the  beneficial 
agency  of  a  high  temperature,  or  "  sharp  fire,"  as  it  is  termed,  this  perhaps  depends 
upon  the  sudden  fusion  of  the  materials  before  the  carbonic  acid  of  either  of  the 
carbonates  has  had  time  to  escape;  consequently,  a  much  more  active  "boil"  and 
thorough  intermixture  must  occur  under  such  circumstances  than  where  this  gas  has 
been  suffered  to  pass  off  in  great  part  before  fusion.  This,  however,  would  only  diminish 
the  individual  size  of  the  striai  by  multiplying  their  number ;  and  such  glass  must, 
even  under  the  most  favourable  circumstances,  suffer  greatly  by  comparis()n  with  that 
of  St  Gobain.  Nor  can  improvement  be  hoped  for  until,  as  in  France,  in  this  particular 
case,  science  is  linked  hand  in  hand  with  manufacturing  industry.  Since  the  grand 
discovery  made  by  Dalton,  that  Nature  works  in  definite  proportions,  there  can  be 
no  excuse  for  continuing  to  follow  the  doctrine  of  chance,  with  its  occasional  successes 
and  frequent  failures — the  alternations  of  hope  and  despair.  The  laws  which  regu- 
late the  entire  universe  are  not  more  immutable  than  those  which  tend  to  unite  silica 
and  soda  in  equivalent  proportions.  It  is,  therefore,  simply  futile  to  battle  with 
such  a  power  ;  for  even  when  success  seems  on  the  point  of  attainment,  we  find 
Nature  reasserting  her  dominion,  and  stamping  those  works  of  man  which  have 
been  pursued  in  defiance  of  her  laws  with  the  indelible  impress  of  imperfection  and 
error. 

That  glass  of  all  kinds  may  be  made  in  this  country  quite  equal  to  that  of  St.  Gobain, 
is  saying  no  more  than  that  Nature's  laws  are  universal.  But,  remembering  the  great 
facilities  we  possess  as  a  glass  manufacturing  nation,  the  attainment  even  of  .'^uch  a 
result  is  but  a  sorry  flight  of  ambition.  We  are  placed  in  a  position  which  demands 
from  us  something  more  than  mediocrity  or  successful  competition,  as  no  nation  in  the 
world  possesses  the  same  amount  of  natural  advantages.  In  fuel,  in  s(»da,  in  sand,  in 
chalk,  in  litharge,  we  are  naturally  rich  to  overflowing.  Our  capital  and  conmieice  give 
us  the  command  of  every  market ;  our  manufacturers  need  only  ask  and  have.  So  long 
as  a  miserable  fiscal  impost  sat  like  an  incubus  upon  the  back  of  the  glas-j-making 
interest,  inferiority  was  unavoidable;  but  the  humiliating  aspect  of  the  British  plate 
glass  throughout  the  Great  Exhibition  is  scarcely  palliated  by  this  excise  reminiscence ; 
and  we  refrain  from  terming  it  a  national  disgrace  only  under  a  belief  that  already 
improvement  has  begun,  which  will  thrust  these  specimens  into  the  oblivious  records  of 
the  past. 

An  Achromatic  Telescope  of  gigantic  dimensions  and  powers,  which  is  now  being 
constructed  for  the  Rev.  Mr.  Craig,  Vicar  of  Leamington,  under  the  superintendence  of 
W.  Cravatt,  Esq.  F.R.S.,  has  been  the  occasion  of  the  manufacture  of  some  admirable 


930 


GLASS. 


optical  flmt  object  glasses  at  the  great  works  of  Messrs.  Chance,  of  Birmincrha.n      It  U 
24  inches  in  diameter,  and  is  perfectly  clear  and  homogeneous  in  structure.  ^The  crown 

S^  '"';^  f  1'  Tf'  "  ""^  P^^'*'  ^^^^'  ^""'^  ^y  ^^'^  Thimes  Plate-glass  Company.  The 
Ota  length  of  the  telescope  in  use  will  be  85  feet,  but  the  real  focal  length  ot' the  lens  s 
much  ess,  being  probably  about  76  feet.  A  quarter  of  an  inch  letter  ?an  be  read  with 
this  telescooe,  even  in  its  imperfect  state,  at  the  distance  of  half  a  mile.  It  promises  to  bo 
as  powerful  as  Lord  Rosses  colossal  reflector,  and  it  is  mounted,  in  its  observatory  on 
Wandsworth  Common  on  such  mechanical  principles,  as  to  be  moveable  in  any  direJ  ion 
with  the  slightest  touch  of  the  finger,  while  it  can  be  directed  to  objects  at  2o°  of  deva 
tion  above  the  hor.zen,  The  weight  of  the  tube  is  3  tons  ;  it  is  quite  inflexible  and  free 
flora  tremor  or  vibration.     The  cham  by  which  the  tube  is  lowered  or  raised  is  capable 

Glass  feom  Alkaline  Sulphates.  Messrs.  Balmain  and  Parnell  have  patented 
a  process  for  making  glass  from  alkaUne  sulphates,  m  which  they  first  make  T^  S 
by  ign.ting  sulphate  of  soda  with  sand  and  charcoal  powder,  for  example    so  art, 

nerl"n/'T  ^^"^i^^  *^-  '^^  ^'  ^^°*-  «^  ^^^^^'^'  To  make 'a  silicate  Cf  abou'  ^ 
per  cent,  of  soda,  they  mix  3  cwt.  of  sand,  2  cwt.  of  dry  sulphate  of  soda  in  fine 
powder,  and  from  16  to  18  lbs.  of  finely  ground  charcoal,  and^heat  t he  m  xture  to 
whiteness  ma  furnace.  As  the  silicate  faUs  from  the  fu;nace  it  is  received  into  a 
vesse  of  water,  which  renders  it  more  easy  to  grind,  and  by  dissolving,  the  excess 
of  sulphate,  presents  that  substance  in  a  convenient  form  for^  being  rec°overed  To 
make  a  silicate  of  soda  of  12  per  cent  of  soda,  3  parts  of  sand  and  1  p?rt  of  sZ^te  of 
8oda  are  mixed  and  the  mixture  is  heated,  with  occasional  stirring,  in  the  fnrnLe  Bv 
exposure  to  a  low  red  heat  for  from  6  to  10  hours,  a  perfect  sHi^te  of  0^111  hi 
formed  A  silicate  of  potash  of  26  per  cent,  is  made  by  Seating  3^  cwt.  of  sand  ^i  cwt 
l'£p  ^'^P"''''^'  '"'^  ]\  PT^^  '^  ^^^^°^^-  «onietim1.s  both  a  sulphatJ  'md 
TuWe  Jnicate^  ""■"  °  '  sometimes  two  bases  are  used  to  make  a 

of  InlnL'it'^'T  ^'^""i"^^  equivalents  are  observed  ;  a  single  equivalent  of  charcoal  to  one 
of  sulphate  To  make  a  double  silicate  of  soda  and  bary  tes,  either  of  the  followin-  mix- 
lures  may  be  used  : —  '^ 

Tf.f  o  h\V^  parts  of  sand,  72  sulphate  of  soda,  117  sulphate  of  bary  tes,  and  12  charcoal. 
•  h^^  f  °'^'  ^-  «"JP'^^'^  «f  ^"«da,  99  carbonate  of  barytes,  and  6  charcoal.   A  flow  of 
sulphate  indicates  want  of  charcoal,  and  a  brown  colour  in  the  result  an  excels  of  char- 
coal;  but  both  of  these  accidents  may  be  produced  by  too  low  a  heat  in  the  furnace, 

I  he  highest  working  temperature  is  a  fair  white  heat.  The  addition  of  5  or  10  per  cent 
of  common  salt  aids  the  fluxmg,  and  is  not  hurtful  to  the  result.  The  sulphate  should  be 
in  fine  powder.  The  patentees  also  use  a  sulphuret  or  hyposulphite  as  a  decomposing 
agent  for  the  sulphates  instead  of  cliarcoal.  Half  an  equivllent  proportion  of  suXret 
or  a  single  eqmvalent  of  hyposulphite,  should  be  used  in  the  place  of  each  equivalent  of 
the  charcoal;  as  for  example  20  parts  of  sulphuret  of  sodium  for  6  parts  of  charcoal 
Ihese  decompositions  and  combmations  are  efiected  by  means  of  a  peculiar  reverberatory 
furnace  with  two  inclined  beds  or  flues  through  which  the  fire  passes  and  plays - 
jye^otons  Journal,  XXXV.  223.  ^  F-Jo- 

ar  J^for"^— ^^  ^""^"^^^^  '"  ^^"^  ^' "'^""'^  Kingdom,  upon  the  different  descriptions  of  glass 

Window  glass,  any  kind,  not  exceeding  -^  inch 
thickness      -  -  -  -  -     0     3     6  per  cwt. 

All  glass  exceeding  ^  inch  thickness,  and  all 
silvered  or  polished  glass,  superficial  mea- 
sure: -  -  -  .  . 

Not  exceeding  9  square  feet        -  -00     3  per  square  foot. 

i^noo.i.r,„        9  and  not  14  square  f^^et  -     0     0     6  — 


Exceeding: 


—  14       „        36 

—  36  and  upwards 
Painted  or  ornamented 

All  white  flint  glass  bottles,  not  cut,  engraved, 
or  otherwise  ornamented,  and  beads  and 
bugles  -  -  -  .  . 

Wine  glasses,  tumblers,  and  all  other  white 
flint  glass  goods  not  cut,  engraved,  or  other- 
wise ornamented     -  -  •  . 

All  flint  cut  glass,  flint  coloured  glass,  and  fancy 
ornamental  glass    ...  * 


0  0     7i  — 

0  0     9  — 

0  0     9  per  superficial  foot. 

0  0  0^  per  lb. 

0  0  1     — 

0  0  2  per  lb. 


GLASS  (BOHEMIAN).  931 

£  s.  d. 

Bottles  of  glass  covered  with  wicker  (not  being 
flint  or  cut  glass),  or  of  green  or  common 
glass  -  -  -  -  -     0    0    9  per  cwt. 

Unenumerated,  and  old  broken  glass    -  -     0     3     6  per  cwt. 

Glass,  Austrian.  M.  Peligot  states  that  tlie  hard  glass  of  Bohemia  is  composed  of 
100  parts  of  silica,  12  parts  of  quicklime,  and  only  28  parts  of  carbonate  of  potash. 
These  proportions  give  a  glass  quite  unmanageable  in  ordinary  furnaces ;  but  the  ad- 
dition of  a  comparatively  small  quantity  of  boracic  acid  is  capable  of  determining 
fusion,  and  the  result  is  a  glass  having  all  the  requisite  limpidity  at  a  high  temperature 
and  possessing  at  the  same  time  a  great  brilliancy  and  hardness. 

Glass,  Bohemian.  Glasses  are  silicates  which  must  contain  at  least  50  per  cent,  of 
silica;  the  more  there  is  of  it,  the  more  perfect,  unalterable,  hard,  and  infusible  is  the 
glass.  The  hardest,  most  beautiful,  and  most  perfect  glass,  is  found  in  nature  in  the  state 
of  pure  silica  in  rock  crystal.  To  render  silica  fusible,  certain  fluxes  must  be  added : 
these  fluxes  are  potassa,  soda,  lime,  and  oxide  of  lead. 

Silica  fuses  very  well  with  the  alkalis,  but  the  resulting  glass  is  rapidly  changed  by 
absorbing  moisture  from  the  air.  To  prevent  this  alteration,  it  is  always  necessary,  in 
the  manufacture  of  glass,  to  introduce  a  certain  quantity  of  lime  or  of  oxide  of  lead. 

In  the  following  table  is  given  the  analyses  of  a  certain  number  of  Bohemian  glasses, 
which  will  indicate  their  composition  with  precision. 


Silica 

Potassa 

Soda 

(1.) 

(2.) 

(8.) 

(4.) 

(6.) 

(6.) 

(7.) 

(8.) 

71-6 
110 

71-7 

12-7 

2-3 

10-3 

0-4 
0-3 
0.2 

69-4 
11-8 

9-2 

9-6 

62-8 
22-1 

12-6 

2-6 

75-9 

17-5 

3-8 

2-8 

78-85 
5-5 

1205 
5-6 

3-5 

70- 
20- 

4- 

5- 

0-6 

0-4 

57- 
25- 

12-5 

s- 

1-8 

0-4 

Lime 

Magnesia  .... 
Alumina  .... 
Oxide  of  Iron  -  -  - 
Oxide  of  Manganese  - 

10- 
2-3 
2-2 
3-9 
0-2 

101-2 

981 

100- 

100- 

100- 

100-5 

100- 

99-2 

(1.)  Bohemian  glass  from  Neufeld,  (M.  Grus) ;  its  composition  is  represented,  nearly 
by  the  formula,  Ca  S*  -f  (Al  F)  S=  +  (K  Mg  Mn)  S». 

(The  reader  will  remember,  that  these  are  mineralogical,  and  not  chemical,  symbols 
since  the  letters  signify  the  oxides,  or  acids,  and  not  the  elementary  bases,  as  they  would 
in  chemistry. — Trans,) 

(2.)  A  tine  table  glass  from  Neuwelt  (M.  Berthier) ;  it  is  exceedingly  beautiful,  and 
is  prepared,  according  to  M.  Perdonnet,  with  a  mixture  of  100  quartz,  5o'caustic  lime,  75 
carbonate  of  potassa,  and  a  very  small  quantity  of  nitre,  arsenious  acid,  and  oxide  of 
manganese.  The  presence  of  arsenic  cannot  be  detected  by  analysis.  The  composition 
of  this  glass  is  expressed  by  the  formula  C  S «  +  (K  N)  S «. 

(3.)  Old  Bohemian  glass,  (M.  Dumas) ;  its  formula  is  (Al  C  K)  S*. 

(4.)  Crown  glass  of  German  manufacture,  (hL  Dumas) ;  its  composition  is  expressed 
by  the  formula  (K  C)  S  ♦. 

(5.)  Glass  for  mirrors,  (M.  Dumas) ;  it  is  represented  by  the  formula  (N  Al  C)  S  •. 

(6.)  Another  glass  for  mirrors,'  (M.  Dumas) ;  its  formula  lies  between  B  S »  and 
BS«. 

(7.)  White  table  glass,  from  Silberberg  near  Gratzen ;  its  composition  is  exactly  ex- 
pressed by  the  formula,  2  (K  Ca)  S  ^  -f  (Al  F)  S  \ 

(8.)  Mirror  glass  from  New-Hurkenthal,  for  the  manufacture  of  cast  mirrors.  It 
shows  a  greenish  tint  in  section,  and  softens  at  a  gentle  heat.  Its  composition  is  nearly 
represented  by  the  formula  ( Al  F)  S^  +  6  (K  C  M)  S^,  or  more  simply  (K  C  Al)  S'. 

Properties  of  Glass,  'Transparence,  Colourlessness. — Transparence  and  colourlessnesa 
are  the  first  properties  of  glass :  to  obtain  them,  the  materials  must  be  employed  ex- 
tremely pure,  and  the  least  possible  flux  added ;  an  excess  of  potassa  gives  the  glass  a 
greenish  tint;  soda  and  its  salts  give  it  a  yellow  tint,  and  lime  renders  it  milky.  A 
very  small  quantity  of  the  sulphate  of  potassa,  or  soda,  gives  it  a  yellowish,  or  blackish, 
brown  green ;  iron  colours  it  strongly  bottle  green ;  and  an  excess  of  the  manganese 
employed  to  remove  the  coloration  due  to  the  oxide  of  iron,  gives  it  a  bluish  tint,  which 
becomes  a  decided  violet  by  the  action  of  the  solar  light.     If  the  minium  employed  in 

6  C  2 


932 


GLOVE  MANUFACTURE. 


•i 


i  i! 


the  manufacture  of  crystal  contains  a  little  copper,  which  very  often  happens,  the  orvstal 
takes  a  slight  emerald  green  tint;  ths.  however,  is  not  to  b^  feared  in  Bohemia,  Xre 
there  is  but  a  smgle  establishment  which  makes  lead  glass. 

Charcoal  colours  glass  of  a  topaz  yellow,  more  or  less  dark,  and  sometimes  reachinn- 
a  purple,  so  that  it  is  impossible  to  obtain  a  perfectly  colourless  glass  in  furnaces  which 
smoke  or  m  those  which  are  heated  by  turfrTignite;  or  bituminous  coal;  andTnTS 
cases  it  IS  necessary  to  employ  covered  crucibles,  as  is  done  in  the  manufactory  of  crystal 
at  Cho.sy-le.Roi;  It  IS  also  necessary  on  this  account,  when  in  tlie  fabrication  of  glass 
«^^M1  carbonates  are  replaced  by  sulphate  of  soda,  to  add  in  the  crucible  a  little 
(about  Jj)  less  of  carbon  than  would  be  necessary  to  reduce  the  sulphate  completelv 
and  even  thus  but  common  glass  is  obtained  by  this  process,  smce  the  slight  excess  Jf 
sulphate  of  soda,  which  must  be  left,  gives  a  blackish  brown  tint  ^ 

IJardness,  Mashcity— The  Bohemian  glass  is,  within  certain  limits,  perfectly  elastic 
and  very  sonorous ;  when  well  made,  it  is  sufficiently  hard  to  strike  fire  with  s^ee  and 
m  scratched  with  difficulty.     The  lead  glasses,  on  the  other  hand,  have  but  little  hard 

r^nt'lf"^     fr,'"  PT'*'''"   ^'  ^^^y  ^"'^tai"  niore  oxide  of  lead;  besides  which  thev 
rapidly  lose  their  brilliancy  by  use.  - 

Fusibility  Cooling,  Annealing,  Bevitriji cation.- KM  glass  is  more  or  less  fusible  •  when 
U  IS  softened  by  the  action  of  heat,  it  may  be  worked  with  the  greatest  ease,  arid  may 

^■.ttT  -^^  \T  '*''?^"  ?.'  ^"."  ^^  *^^«^  "^  *^^  '^^^^^^^  °f  *h«  silkworm.  Glass,  when 
It  8  submitted  to  rapid  cooling,  becomes  very  fragile,  and  presents  several  very  remark- 
able phenomena,  among  which  I  will  cite  as  an  example  Prince  Rupert's  drops  Gla«s 
supports  variations  of  temperatures  better  in  proportion  as  it  has  been  more  slowly 
cooled  ;  thus  when  It  has  been  but  slightly  annealed,  or  not  at  all,  its  fragHty  3 
be  considerably  diminished  by  annealing  it  in  water,  or  better,  in  boilin..  oil  °  ^  ^ 
All  glass  exposed  during  a  longer  or  shorter  time  to  a  heat  sufficiently  elevated  loses 
Its  transparency,  and  becomes  extremely  hard,  and  much  less  brittle  than  before 
ivlfrv  J«  t  ^If  ^  ?  phenomenon  precisely  similar  to  that  which  we  see  taking  place 
VZLt^'  ^      ni         ""^^'"^  °5  *^u^  '^''*^'  ^^  ^"''  «"^1^"'S  ^"™^<^^«'  «"d  especially  in 

biirrs  ot^T        *       "  """""^  ^"^'^^^  ^"""^  ^^^^  ^^^"^  '^^°  ^^'*^  "^^^"^^ 

Density.— Be\ovf  is  given  the  density  of  several  glasses  without  lead:— 


GLOVE-SEWING. 


933 


Old  Bohemian  glass  (Dumas) 
Bohemian  bottle  glass 

do.  window  glass 

Fine  glass,  called  Bohemian  crystal 
Min-or  glass  of  Cherbourg.  (Dumas) 

da        St.  Gobain 

da        Newhaus  1812,  (Scholz) 

da  do.     1830. 


2-396 

3-782 
2-642 
2-892 
2-506 
2-488 
2-551 
2653 


Action  of  Atmospheric  and  Chemical  Agents.— The  harder  and  more  infusible  a  glass  is 
the  less  is  it  alterable  by  the  action  of  atmospheric  and  chemical  agents,  with  the  exception 
of  hydrofluoric  acid.  Glass  which  is  too  alkaline  attracts  gradually  the  moisture  of  the 
air  and  loses  its  lustre  and  polish.  Many  glasses  are  perceptibly  attacked  by  a  prolonjred 
boiling  with  water,  and  a  fortiori  by  acid  and  alkaline  solutions;  thus,  the  bottle  l'Hss 
IS  frequently  attacked  by  the  tartar  which  is  found  in  the  wine.  According  to  Guvton 
Morveau  all  glass  which  is  attacked  by  prolonged  boiling  with  concentrated  solutions 
ot  alum,  common  salt,  sulphuric  acid,  or  potassa,  is  of  bad  quality. 

The  silica  which  is  employed  in  Bohemia  in  the  manufacture  of  glass,  is  obtained  by 
calcining  crystalline  quartz,  and  afterwards  pounding  it  while  dry.  When  the  quartz 
has  been  heated  to  a  cherry-red,  it  is  withdrawn  from  the  fire,  and  thrown  immetJiatelv 
into  cold  water.  J 

Almost  all  the  Bohemian  glass  is  a  potash  glass,  because  soda  and  its  salts  cive  to 
glass  a  sensible  yellowish  tint.     The  limestone  which   is  used  is  as  white  as  Carrara 
marble.     The  clay  employed  for  the  crucibles  is  very  white,  and  consists  of  silica  45-8 
alumina  40 A,  and  water  13y"y.  »*' 

GLAUBER  SALT  is  the  old  name  of  sulphate  of  soda. 

GLAZES.    See  Pottery. 

GLAZIER,  is  the  workman  who  cuts  plates,  or  panes  of  glass,  with  the  diamond,  and 
iastens  them  by  means  of  putty  in  frames  or  window  casements.  See  Diamond  for  an 
explanation  of  its  glass-cutting  property.  ' 

GLOVE  MANUFACTURE.      In   February,   1822.  Mr.   James    Winter   of  Stoke 
onder-Hambdon,  m  the  county  of  Somerset,  obtained  a  patent  for  an  improvement  upon 


a  former  patent  machine  of  his  for  sewing  and 
pointing  leather  gloves.      Fig.  727  represents 
a  pedestal,  upon  which  the  instrument  called 
the  jaws  is  to  be  placed.     Fig.  728  shows  the 
jaws,  which  instead  of  opening  ana  closing  by 
a  circular  movement  upon  a  joint  as  described 
in  the  former  specification,  are  now  made  to 
open  and  shut  by  a  parallel  horizontal  move- 
ment, efiected  by  a  slide  and  screw ;  a  a  is  the 
fixed  jaw,  made  of  one  piece,  on  the   under 
side  of  which  is  a  tenon,  to  be  inserted  into 
the   top  of  the   pedestal.      By  means  of  this 
tenon  the  jaws  may  be  readily  removed,  and 
another  similar  pair  of  jaws  placed   in  their 
stead,  which  affords  the  advantage  of  expediting 
the  operation  by  enabling  one  person  to  pre- 
pare the  work  whilst  another  is  sewing  ;  6  6  is 
the  moveable  jaw,  made  of  one  piece.     The 
two  jaws  being  placed  together  in  ihe  manner 
shown  at^g.  728,  the  moveable  jaw  traverses 
backwards  and  forwards  upon  two  guide-bars, 
c,  which  are  made  to  pass  through  holes  ex- 
actly fitted  to  them,  in  the  lower  parts  of  the 
jaws.    At  the  upper  parts  of  the  jaws  are 
what  are  called  the  indexes,  d  d,  which  are 
pressed  tightly  together  by  a  spring,  shown  at 
fig,  729,  and   intended  to  be   introduced  be- 
tween the  perpendicular  ribs  of  the  jaws  at 
,       ..     /.      ,  *•      At  /  is  a  thumbscrew,  passing  through 

the  ribs  for  the  purpose  of  tightening  the  jaws,  and  holding  the  leather  fast  between  the 
indexes  while  being  sewn ;  this  screw,  however,  will  seldom,  if  ever,  be  necessary  if  the 
spring  is  sufficiently  strong ;  g  is  an  eye  or  ring  fixed  to  the  moveable  jaw,  through  which 
the  end  of  a  lever,  h,  in  fig.  727  passes  ;  this  lever  is  connected  by  a  spring  to  a  treadle, 
t,  at  the  base  of  the  pedestal,  and  by  the  pressure  of  the  right  foot  upon  this  treadle, 
the  moveable  jaw  is  withdrawn  ;  so  that  the  person  employed  in  sewing  may  shift  the 
leather,  and  place  another  part  of  the  glove  between  the  jaws.  The  pieces  called  indexes 
are  connected  to  the  upper  part  of  the  jaws,  by  screws  passing  through  elongated  holes 
which  render  them  capable  of  adjustment. 

The  patentee  states,  that  in  addition  to  the  index  described  in  his  former  patent,  which 
IS  applicable  to  what  is  called  round-seam  sewing  only,  and  which  permits  the  leather  tc 
expand  but  in  one  direction  when  the  needle  is  passed  through  it,  namely,  upwards  he 
now  makes  two  indexes  of  different  construction,  one  of  which  he  calls  the  recedine 
index,  and  the  other  the  longitudinally  grooved  index.     Fig.  730  represents  an  end  view 
u  •??:  ,       *  ^®P  y'^^  ^^^^^  receding  index,  which  is  particularly  adapted  for  what  are 
called  "drawn  sewing,  and  prick-seam  sewing;"  this  index,  instead  of  biting  to  the  ton 
IS  so  rounded  off  in  the  inside  from  th^  bottom  of  the  cross  grooves,  as  iS  permit  the 
needles,  by  being  passed  backwards  and  forwards,  to  carry  the  silk  thread  on  each  side 
of  the  leather  without  passing  over  it.     Fig.  732  represents  an  end  view  of  the  loneitu- 
dinally  grooved  index,  partly  open,  to  show  the  section  of  the  grooves  more  distinctly 
^nd  fig    iU  represents  an  inside  view  of  one  side  of  the  same  index,  in  which  the  lono-il 
ludinal  groove  is  shown  passing  from  k  to  /.     This  innex  is  more  particularly  adapted  to 
round  seam  sewing,  and  permits  the  leather  to  expand  in  every  direction  when  the  needle 
IS  passed  through  it,  by  which  the  leather  is  less  strained,  and  the  sewing  consequently 
rendei  ed  much  stronger.  r>  ^        j 

It  is  obvious  that  the  parallel  horizontal  movement  may  be  effected  by  other  mechani- 
cal  means  besides  those  adopted  here,  and  the  chief  novelty  claimed  with  respect  to  that 
movement,  is  its  application  to  the  purpose  of  carrying  the  index  used  in  sewing  and 
pointing  leather  gloves.  ° 

Importation  of  leather  gloves  for  home  consumption ;  and  amount  of  duty  in 
1836.  1837.  I  1836.  1837. 

1,461,769.      I      1,221,350.      |      £27,558.  £22,923. 

GLOVE-SEWING.  The  following  simple  and  ingenious  apparatus,  invented  by 
an  Enshshman,  has  been  employed  extensively  in  Paris,  and  has  enabled  its  proprietor* 
to  realize  a  handsome  fortune.  The  French  complain  that  "it  has  inundated  the  world 
with  aloves,  made  of  excellent  quality,  at  30  per  cent,  under  their  former  wholesale 


934 


GLUE. 


.:i 


i< 


GLUE. 


935 


I  *       s       s  1 


prices."  The  instrument  is 
shown  in  profile  ready  for  ac 
tion  in  Jig.  734.  It  resembles 
an  iron  vice,  having  the  upper 
portion  of  each  jaw  made  of 
brass,  and  lipped  with  a  kind 
of  comb  of  the  same  metal.  The 
teeth  of  this  comb,  only  one 
twelfth  of  an  inch  long,  are 
perfectly  regular  and  equal. 
Change  combs  are  provided  for 
different  styles  of  work.  The 
vice  A  A  is  made  fast  to  the 
edge  of  the  bench  or  table  b, 
of  the  proper  height,  by  a 
thumb-screw  c,  armed  with  a 
cramp  which  lays  hold  of  the 
wood.  Of  the  two  jaws  com- 
•    _  J    -   ^ ,    ,,     ,,  ,       ,  posing  the  machine,  the  one  d 

is  made  fast  to  the  loot  a  a,  but  the  other  e  is  moveable  upon  the  solid  base  of  the  machine, 
by  means  of  a  hmge  at  the  pomt  r.  At  n  is  shown  how  the  upper  brass  portion  is  ad- 
justed to  the  lower  part  made  of  iron  ;  the  two  being  secured  to  each  other  by  two  stout 
screws.  The  comb,  seen  separately  in  fig,  -JSe,  is  made  fast  to  the  upper  end  of  each 
jaw,  by  the  three  screws  nnn.  Fig.  735  is  a  front  view  of  the  jaw  mounted  with  its 
comb,  to  illustrate  its  construction. 

The  lever  k  corresponds  by  the  stout  iron  wire  l,  with  a  pedal  pressed  by  the  needle- 
woman s  foot,  whenever  she  wishes  to  separate  the  two  jaws,  in  order  to  insert  between 
them  the  parallel  edges  of  leather  to  be  sewed.  The  instant  she  lifts  her  foot,  the  two 
jaws  join  by  the  force  of  the  spring  g,  which  pushes  the  moveable  jaw  e  against  the 
stationary  one  d.    The  spring  is  made  fast  to  the  frame  of  the  vice  by  the  screw  h. 

Atier  putting  the  double  edge  to  be  sewed  in  its  place,  the  woman  passes  her  needle 
successively  through  aU  the  teeth  of  the  comb,  and  is  sure  of  makiiig  a  regular  seam  in 
every  direcuon,  provided  she  is  careful  to  make  the  needle  graze  along  the  bottom  of  the 
notches.  As  soon  as  this  piece  is  sewed,  she  presses  down  the  pedal  with  her  toes. 
Whereby  the  jaws  start  asunder,  allowing  her  to  introduce  a  new  seam,  and  so  in  quick 
succession.  ^ 

The  comb  may  have  any  desired  shape,  straight  or  curved;  and  the  teeth  may  be 
larger  or  smaller,  according  to  the  kind  of  work  to  be  done.  With  this  view,  the  combs 
mignt  be  changed  as  occasion  requires;  but  it  is  more  economical  to  have  sets  of  vices 
ready  mounted  with  combs  of  every  requisite  size  and  form. 

discov^rpH^t  ^vJ^^'^'r  ^'' '  ^'^7^^':^'  p^'"")'  i«  one  of  the  primitive  earths,  originally 

thie  mhl^l  h  ?"  ;"'  V"  ^"^^/"^  ^™"^^^^-  ^'  "^^y  ^  ^^tracted  from  either  of 
these  minerals,  by  treating  their  powder  successively  with  potash,  with  water  and  with 
muriatic  acid.    The  solution  by  the  latter,  being  evaporatecf  to  drV™  il  to  L  di-el^d 

7nt  If  I'i  """^  ^^*f ''^;  ^"  P°"""^  '^'^^'^  «f  ^'""^""i^  in  exJess  ito  he  liquid  we 
form  soluble  muriate  of  ammonia,  with  insoluble  carbonates  of  lime,  chrome  and  "ron  I^ 
also  carbonate  of  glucina,  which  may  be  dissolved  out  from  the  rest  by  anTx(;esrof  rarbo 

Lt^ciSd  in  twt^  ^"'  t^^'ri'^  T-^'  ^'^^  ^^"^'^  passTsThr^gh  ^nd  mt 
csTmnlo^l  ll^^^y  ^f  ^  carbonate  by  boiling  the  liquid,  which  expefs  ihe  excels 
It  n  wWte  ^^,.^f?  ^"^'  ^'y'^S,  ^^dc^lcmmg  the  carbonate,  pure  glucina  is  obtained. 

water  brtsohZ^n  ^Z^''  f^^^^.  '".'^'^  ^'^^  «^  *  «™^t^'«  ^«''&«.  in«"l"ble  in 
water  but  soluble  m  caustic  potash  and  soda;  as  also,  especially  when  it  is  a  hydrate 

iombinr  wk''4r2?r5  ''  '"."  T''^  ^^^^^  '^'"'^  gLinu^.^Jvhich  lOo'  pans 
rp;lLrn^n  manlf^ctuTJs"^"  '^  '""  *'^  ''''''''      ''  ''  '^^  ^^  '«  ^  ^--p'^'^^^ 

m  nF^f^/7.  V'^  ""T^  ^^"^ •  °  *^^^P^  ^'^^  ^^^""^^  ^n^ar  by  M.  Dumas, 
tin?  ^7!  d^  sta<e  'Thp'  ^''"'^  ^^^^^^erlnm.  Germ.)  is%he  chemical  substance  gela- 
tine i„  a  dry  state.  The  preparation  and  preservation  of  the  skin  and  other  animal 
matters  employed  m  the  manufacture  of  glue,  constitute  a  peculiar  branch  of  indu  "y 
to  S  m.nUh  f^'^'f  'f '^'""'^  ''k^^,*"  P"-^"^"^  *^«  fermentation  of  the Tubstancet  a  mi 
^  Zne  Thev  maf  Z:'r  ^y/.^P"^^"^  them  of  as  much  water  as  can  conveni'ently 
rpopr^'  ♦];  ^  r^  •  •  '^u^  '"  P'-eparation  by  macerating  them  in  milk  of  lime. 
LwormpdTnT.r  '/T''  ?  '^^  ''"■■' VJ  ^  ^^^•'"'S^^t  «^  thre^  ^«^ks.  This  process 
im^e  Ind  laid  in  .f!  ^^    /  ^^ ,"1^^^"^'.    They  are  next  taken  out  with  all  the  adhering 

wWe  thPv  ip  ^^Tl  "'  I  '°'^''  *^f ^'  *^  ^''f'"  ^"d  ^'y>  "P«n  *  «l«pi"g  pavement^ 
where  they  are  turned  over  by  prongs  two  or  three  times  a  Say.    The  action  of  the 


lime  dissolves  the  blood  and  certain  soft  parts,  attacks  the  epidermis,  and  disposes  the 
gelatinous  matter  to  dissolve  more  readily.  When  the  cleansed  matters  are  dried,  they 
may  be  packed  in  sacks  or  hogsheads,  and  transported  to  the  glue  manufactory  at  any 
distance.  The  principal  substances  of  which  glue  is  made  are  the  parings  of  ox  and 
other  thick  hides,  which  form  the  strongest  article*,  the  refuse  of  the  leather  dresser ; 
both  afford  from  45  to  55  per  cent,  of  glue.  The  tendons,  and  many  other  offals  of 
slaughter-houses,  also  afford  materials,  though  of  an*  inferior  quality,  for  the  purpose. 
The  refuse  of  tanneries,  such  as  the  ears  of  oxen,  calves,  sheep,  <tc.,  are  better  articles ; 
but  parings  of  parchment,  old  gloves,  and,  in  fact,  animal  skin  in  every  form,  uncom- 
bined  with  tannin,  may  be  made  into  glue. 

The  manufacturer  who  receives  these  materials  is  generally  careful  to  ensure  their 
purification  by  subjecting  them  to  a  weak  lime  steep,  and  rinsing  them  by  expiviure 
in  baskets  to  a  stream  of  water.  They  are  lastly  drained  upon  a  sloping  surface,  as  abovo 
described,  and  well  turned  over  till  the  quicklime  gets  mild  by  absorption  of  carbonic 
acid ;  for,  in  its  caustic  state,  it  would  damage  the  glue  at  the  heat  of  boiling  wator.  It 
is  not  necessary,  however,  to  dry  them  before  they  are  put  into  the  boiler,  because  they 
dissolve  faster  in  their  soft  and  tumefied  state. 

The  boiler  is  made  of  copper,  rather  shallow  in  proportion  to  its  area,  with  a  uniform 
flat  bottom,  equably  exposed  all  over  to  the  flame  of  the  fire.  Above  the  true  bottom 
there  is  a  false  one  of  copper  or  iron,  pierced  with  holes,  and  standing  upon  feotv  3  or  4 
inches  high;  which  serves  to  sustain  the  animal  matters,  and  prevent  them  from  bfiujf 
injured  by  the  fire.  The  copper  being  filled  to  two-thirds  of  its  height  with  soft  water, 
-s  then  heaped  up  with  the  bulky  animal  substances,  so  high  as  to  surmount  its  Urim. 
But  soon  after  the  ebullition  begins  they  sink  down,  and,  in  a  few  hours,  get  tiitirelv 
immersed  in  the  liquid.  They  should  be  stirred  about  from  time  to  time,  ami  well 
pressed  down  towards  the  false  bottom,  while  a  steady  but  gentle  boil  is  maintained. 

The  solution  must  be  drawn  off  in  successive  portions;  a  method  which  fractious  the 
products,  or  subdivides  them  into  articles  of  various  value,  gradually  decreasiiiij  troni 
till'  first  portion  drawn  off  to  the  last  It  has  been  ascertained  by  careful  expetinuMits 
that  gelatine  gets  altered  over  the  fire  very  soon  after  it  is  dissolved,  and  it  ought  thtMi- 
fore  to  be  drawn  off  whenever  it  is  sufficiently  fluid  and  strong  for  forming  a  clear 
gelatinous  mass  on  cooling  capable  of  being  cut  into  moderately  firm  slices  by  the  wire. 
This  point  is  commonly  determined  by  filling  half  an  egg-shell  with  the  liquor,  and 
exposing  it  to  the  air  to  cool.  The  jelly  ought  to  get  very  consistent  in  the  course  of  a 
few  minutes;  if  not  so,  the  boiling  must  be  persisted  in  a  little  longer.  When  tiiis  term 
is  attained,  the  fire  is  smothered  up,  and  the  contents  of  the  boiler  are  left  to  settle  for  a 
quarter  of  an  hour.  The  stop-cock  being  partially  turned,  all  the  thin  gelatinous  liquor 
is  run  off  into  a  deep  boiler,  immersed  in  a  warm  water  bath,  so  that  it  may  continue 
hot  and  fluid  for  several  hours.  At  the  end  of  this  time  the  supernatant  clear  liquid  is 
to  be  drawn  off  into  congealing  boxes,  as  will  be  presently  explained. 

The  grounds,  or  undissolved  matters  in  the  boiler,  are  to  be  again  supplied  with  a 
quantity  of  boiling  water  from  an  adjoining  copper,  and  are  to  be  once  more  subjected  to 
the  action  of  the  fire,  till  the  contents  assume  the  appearance  of  dissolved  jelly,  and 
afford  a  fresh  quantity  of  strong  glue  liquor,  by  the  stop-cock.  The  grounds  should  be 
subjected  a  third  time  to  this  operation,  after  which  they  may  be  put  into  a  bag,  and 
squeezed  in  a  press  to  leave  nothing  unextracted.  The  latter  solutions  are  usually  too 
weak  to  form  glue  directly,  but  they  may  be  strengthened  by  boiling  with  a  portion  of 
fresh  skin-parings. 

Fig.  737.  represents  a  convenient  apparatus  for  the  boiling  of  skins  into  glue,  in  which 
there  are  three  coppers  upon  three  different  levels ;  the  uppermost  being  acted  upon  bv 
the  w.oste  heat  of  the  chimney,  provides  warm  water  in  the  most  economical  way  ;  the 
second  contains  the  crude  materials,  with  water  for  dissolving  them ;  and  the  third 
receives  the  solution  to  be  settled.  The  last  vessel  is  double,  with  water  contained 
between  the  outer  and  inner  one ;  and  discharges  its  contents  by  a  stop-cock  into  buckets 
for  filling  the  gelatinizing  wooden  boxes.  The  last  made  solution  has  about  oue-five- 
liundredth  part  of  alum  in  powder  usually  added  to  it,  with  proper  agitation,  after  which 
it  is  left  to  settle  for  several  hours. 

The  three  successive  boils  furnish  three  different  qualities  of  glue. 

Flanders  or  Dutch  glue,  long  much  esteemed  on  the  Continent,  was  made  in  the 
manner  above  described,  but  at  two  boils,  from  animal  offals  well  washed  and  soaked,  so 
as  to  need  less  boiling.  The  liquor  being  drawn  off  thinner,  was  therefore  less  coloured, 
and  being  made  into  thinner  plates  was  very  transparent.  The  above  two  boils  gave 
two  qualities  of  glue. 

By  the  English  practice,  the  whole  of  the-animal  matter  is  brought  into  solution  at 
once,  and  the  liquor  being  drawn  off,  hot  water  is  poured  on  the  residuum,  and  made  to 
boil  on  it  for  some  time,  when  the  liquor  thus  obtained  is  merely  used  instead  of  water 


936 


GLUE. 


GLUTEN. 


937 


upon  a  fresh  quantity  of  glue  materials.     The  first  drawn  off  liquor  is  kept  hot  in  a 
settling  copper  for  five  hours,  and  then  the  clear  solution  is  drawn  off  into  the  boxes. 

inese  boxes  are  made  of  deal,  of  a  square  form,  but  a  little  narrower  at  bottom  than 
ai  lop.  When  very  regular  cakes  of  glue  are  wished  for,  cross  grooves  of  the  desired 
square  torm  are  cut  in  the  bottom  of  the  box.  The  liquid  glue  is  poured  into  the  boxes 
placed  very  level,  through  funnels  furnished  with  filter  cloths,  till  it  stands  at  the  brim 
oi  each.  Ihe  apartment  in  which  this  is  done  ought  to  be  as  cool  and  dry  as  possible, 
lo  lavour  the  solidification  of  the  glue,  and  should  be  floored  with  stone  flags  kept  very 
Clean,  so  that  if  any  glue  run  through  the  seams,  it  may  be  recovered.  At  the  end  of 
r  ^^'  «  ""'  ®^  "s^^%  in  the  morning  if  the  boxes  have  been  filled  over-night,  the 
glue  IS  sufficiently  firm  for  the  nets,  and  they  are  at  this  time  removed  to  an  upper  story, 
mounted  with  ventdating  windows  to  admit  the  air  from  all  quarters.  Here  the  boxes 
are  inverted  upon  a  moistened  table,  so  that  the  gelatinous  cake  thus  turned  out  will 
not  adhere  to  its  surface  ;  usually  the  moist  blade  of  a  long  knife  is  insinuated  round 
tne  sides  of  the  boxes  beforehand,  to  loosen  the  glue.  The  mass  is  first  divided  into 
nonzontal  layers  by  a  brass  wire  stretched  in  a  frame,  like  that  of  a  bow-saw,  and  guideil 
I       7^  A  ^''^  P^^^^"^  ^^  distances  corresponding  to  the  desired  thickness  of  the 

cake  ot  gJue.  The  lines  formed  by  the  grooves  in  the  bottom  of  the  box  define  the 
superhcial  area  of  each  cake,  where  it  is  to  be  cut  with  a  moist  knife.  The  gelatinous 
iayers  thus  formed,  must  be  dexterously  lifted,  and  immediately  laid  upon  nets  stretched 
m  wooden  frames,  till  each  frame  be  filled.  These  frames  are  set  over  each  other  at 
distances  of  about  three  inches,  being  supported  by  small  wooden  pegs,  stuck  into  mor- 
tise holes  m  an  upright,  fixed  round  the  room ;  so  that  the  air  may  have  perfectly  free 
access  on  every  side.  The  cakes  must  moreover  be  turned  upside  down  upon  the  nets 
twice  or  thrice  every  day,  which  is  readily  managed,  as  each  frame  may  be  slid  out  like 
a  drawer  upon  the  pegs  at  its  two  sides. 

The  drying  of  the  glue  is  the  most  precarious  part  of  the  manufacture.  The  least 
disturbance  of  the  weather  may  injure  the  glue  during  the  two  or  three  first  davs  of  its 
exposure  ;  should  the  temperature  of  the  air  rise  considerably,  the  gelatine  may  turn  so 
sott  as  to  become  unshapely,  and  even  to  run  through  the  meshes  upon  the  pieces  below, 
or  It  may  get  attached  to  the  strings  that  surround  them,  so  as  not  to  be  separable  with- 
out plunging  the  net  into  boiling  water.  If  frost  supervene,  the  water  may  freeze  and 
lorm  numerous  cracks  in  the  cakes.  Such  pieces  must  be  immediately  re-melted  and 
le-tormed.  A  slight  fog  even  produces  upon  glue  newly  exposed  a  serious  deterioration  • 
the  damp  condensed  upon  its  surface  occasioning  a  general  mouldiness.  A  thunder- 
storm sometimes  destroys  the  coagulating  power  in  the  whole  lamina  at  once  ;  or  causes 
the  glue  to  turn  on  the  nets,  m  the  language  of  the  manufacturer.  A  wind  too  dry  or 
too  hot  may  cause  it  to  dry  so  quickly,  as  to  prevent  it  from  contracting  to  its  proper 
size  without  numerous  cracks  and  fissures.  In  this  predicament,  the  closing  of  all  the 
flaps  of  the  windows  is  the  only  means  of  abating  the  mischief  On  these  accounts  it 
13  of  importance  to  select  the  most  temperate  season  of  the  year,  such  as  spring  and 
autumn,  for  the  glue  manufacture.  ^     ^ 

After  the  glue  is  dried  upon  the  nets  it  may  still  preserve  too  much  flexibility,  or 
softness  at  least,  to  be  saleable ;  in  which  case  it  must  be  dried  in  a  stove  bv  artificial 
wu  ^"*^^'"  '^  peculiarly  requisite  m  a  humid  climate,  like  that  of  Great  Britain. 
When  sufficiently  dry  it  next  receives  a  gloss,  by  being  dipped  cake  by  cake  in  hoi 


TcjH 


water,  and  then  rubbed  with  a  brush  also  moistened  in  hot  water ;  after  which  the  glue 
is  arranged  upon  a  hurdle,  and  transferred  to  the  stove  room,  if  the  weather  be  not 
sufficiently  hot.  One  day  of  proper  drought  will  make  it  ready  for  being  packed  up  in 
casks. 

The  pale-colored,  hard,  and  solid  article,  possessing  a  brilliant  fracture,  which  is  made 
from  the  parings  of  ox-hides  by  the  first  process,  is  the  best  and  most  cohesive,  and  is 
most  suitable  for  joiners,  cabinet-makers,  painters,  &c.  But  many  workmen  are  influ- 
enced by  such  ignorant  prejudices,  that  they  still  prefer  a  dark-colored  article,  with  some- 
what of  a  fetid  odor,  indicative  of  its  impurity  and  bad  preparation,  the  result  of  bad 
materials  and  too  long  exposure  to  the  boiling  heat. 

There  is  a  good  deal  of  glue  made  in  France  from  hones,  freed  from  the  phosphate  of 
lime  by  muriatic  acid.  This  is  a  poor  article,  possessing  little  cohesive  force.  It  dis- 
solves almost  entirely  in  cold  water,  which  is  the  best  criterion  of  its  imperfection.  Glue 
should  merely  soflten  in  cold  water,  and  the  more  considerably  it  swells,  the  better,  gener- 
ally speakin?,  it  is. 

Some  manufacturers  prefer  a  brass  to  a  copper  pan  for  boiling  glue,  and  insist  much 
on  skimming  it  as  it  boils ;  but  the  apparatus  I  have  represented  renders  skimming  of 
little  consequence.  For  use,  glue  should  be  broken  into  small  pieces,  put  along  with  some 
water  into  a  vessel,  allowed  to  soak  for  some  hours,  and  subjected  to  the  heat  of  a  boil- 
ing-water  bath,  but  not  boiled  itself.  The  surrounding  hot  water  keeps  it  long  in  a  fit  state 
for  joiners,  cabinet-makers,  &.C. 

Water  containing  only  one  hundredth  part  of  good  glue,  forms  a  tremulous  solid. 
When  the  solution,  however,  is  heated  and  cooled  several  times,  it  loses  the  property  of 
gelatinizing,  even  though  it  be  enclosed  in  a  vessel  hermetically  sealed.  Isinglass  or  fish- 
glue  undergoes  the  same  change.  Common  glue  is  not  soluble  in  alcohol,  but  is  pre- 
cipitated in  a  white,  coherent,  elastic  mass,  when  its  watery  solution  is  treated  with  that 
fluid.  By  transmitting  chlorine  gas  through  a  warm  solution  of  glue  a  combination 
is  very  readily  effected,  and  a  viscid  mass  is  obtained  like  that  thrown  down  by  alcohol. 
A  little  chlorine  suffices  to  precipitate  the  whole  of  the  glue.  Concentrated  sulphuric 
acid  makes  glue  undergo  remarkable  changes ;  during  which  are  produced,  sugar  of  gela- 
tine, leucine,  an  animal  matter,  &c.  Nitric  acid,  with  the  aid  of  heat,  converts  glue  into 
malic  acid,  oxalic  acid,  a  fat  analogous  to  suet,  and  into  tannin ;  so  that,  in  this  way, 
one  piece  of  skin  may  be  made  to  tan  another.  When  the  mixture  of  glue  and  niiric 
acid  is  much  evaporated,  a  detonation  at  last  takes  place.  Strong  acetic  acid  renders 
glue  first  sofl  and  transparent,  and  then  dissolves  it.  Though  the  solution  does  not 
gelatinize,  it  preserves  the  property  of  gluing  surfaces  together  when  it  dries.  Liquid 
glue  dissolves  a  considerable  quantity  of  lime,  and  also  of  the  phosphate  of  lime  recently 
precipitated.  Accordingly  glue  is  sometimes  contaminated  with  that  salt.  Tannin 
both  natural  and  artificial  combines  with  glue;  and  with  such  effect,  that  one  part  of 
glue  dissolved  in  5000  parts  of  water  affords  a  sensible  precipitate  with  the  infusion  of 
nutgalls.  Tannin  unites  with  glue  in  several  proportions,  which  are  to  each  other  as 
the  numbers  1,  1|,  and  2 ;  one  compound  consists  of  100  glue  and  89  tannin  ;  another 
of  100  glue  and  60  tannin  ;  and  a  third  of  100  glue  and  120  tannin.  These  two  sub- 
stances cannot  be  afterwards  separated  from  each  other  by  any  known  chemical 
process. 

Glue  may  be  freed  from  the  foreign  animal  matters  generally  present  in  it,  by  soft- 
ening it  in  cold  water,  washing  it  with  the  same  several  times  till  it  no  longer  gives  out 
any  color,  then  bruising  it  with  the  hand,  and  suspending  it  in  a  linen  bag  beneath  the 
surface  of  a  large  quantity  of  water  at  60°  F.  In  this  case,  the  water  loaded  with  the 
soluble  impurities  of  the  glue  gradually  sinks  to  the  bottom  of  the  vessel,  while  the  pure 
glue  remains  in  the  bag  surrounded  with  water.  If  this  softened  clue  be  healed  to  92" 
without  addins  water,  it  wdl  liquefy  ;  and  if  we  heat  it  to  122°,  and  filter  it,  some  albu- 
minous and  other  impurities  will  remain  on  the  filler,  while  a  colorless  solution  of  glue 
will  pass  through. 

Experiments  have  not  yet  explained  how  gelatine  «  formed  from  skin  by  ebullition. 
It  is  a  change  somewhat  analogous  to  that  of  starch  into  gum  and  sugar,  and  lakes  place 
without  any  appreciable  disengJigement  of  gas,  and  even  in  close  vessels.  Gelatine,  says 
Beizelius,  does  not  exist  in  the  living  body,  but  several  animal  tissues,  such  as  skin, 
cartilages,  hartshorn,  tendons,  the  serous  membranes,  and  bones,  are  susceptible  of  being 
converted  into  it. 

GLUTEN  (Co//g  Kcge/afe,  Fr. ;  KUbeVy  Germ.)  was  first  extracted  by  Beccaria  from 
wheat  flour,  and  was  long  regarded  as  a  proximate  principle  of  plants,  till  Einhof,  Tad- 
dei,  and  Berzelius  succeeded  in  showing  that  it  may  be  resolved  by  means  of  alcohol  into 
three  different  substances,  one  of  which  resembles  closely  animal  albuinine,  and  has  been 
called  Zi/f«o me,  or  vegetable  albumine;  another  has  been  called  G/ia(it«€;  and  a  third, 
Mucim.  The  mode  of  separating  gluten  from  the  other  constituents  of  wheat  flour  has 
been  described  towards  ihe  end  of  the  article  Bread. 
Gluten,  when  dried  in  the  air  or  a  stove,  diminishes  greatly  in  size,  becomes  hard,  bnt- 


938 


GLYCERINE. 


.'i 


brittle  glistening,  and  of  a  deep  yellow  colour.      It  13  insoluble  in  ethi^r  in  fiif  «n,l 
essential  o.ls  and  nearly  so  in  water.     Alcohol  and  acetic  ScTuse  gl.tn  lo  s  JeU  an 
make  a  sort  of  milky  solution.     Dilute  aqida  and   alkaline  lyes  dissolve  lluten      it 

H.S  process  ,s  a  mechanical  one   (resembling   that   long  practised    in   laWatorK; 
eTh:^^i;^ea  rmrhinly "  ^^^^^  '^--^^  ^^^^  ^  paste^wi^watt: 

Vn^vost'Z!^"d^^^^^^^  "^^^"1  applications  for  alimentary 

-luten  and  7  of  w^te?  k  hi,  ^'"''  '"  ^^^  P':«Portions  of  30  parts  of  flour.   10  of  fresL 
?erSeUi    and  oTher'ki^df  n^  ?^^'"P^"^^'^  ^"^  P^^'^"^  ""  «"P«""^  «^r'  «f  »»a<^«'-o«i. 

and  placed  m  the  Exhibition  samples  of  several  dieteticfl  substLces  3e  ^trXen ' 
^c^h^as  macaroni,  vermiceUi,  a  sort  of  gluten  chocolate,  and  a  kiiJo;  meal'iucuit 

hJt^nlf ™^  ^^  ^*rr"^'  u'^  ^'^^  ^^  ^''  «e"t"e's  foreman,  also  placed  in  the  Exhi- 

T„  f  J    i'°'"P^?''  ''^^Tr  «^  ^l'"^«"t^ry  preparations,  made  with  gluten 
«Jnlf^    »a/ne  category  belongs  Mr.  Bullock's   Semola,  if  which   lie   has  ffiven   an 
account  m  the  Zanc^^  of  December  15   1849  and  Marrh  q   iR^n      t*  :     l^'^'*.  S^®"   »« 
gluten  n«jde  into  a  paste  with  wheat  fl^r.Tnd  gran^urted.''  ''''•     ''  '''  "  '"^''  "'^* 

mediaLaU^r^rsE'lT'  ''f  ^^"''°  "'"Pt^^^  ^^  ^^^^  ^^^^^^^^^^  ^^-«^  wheat  by  a 
mecnanical  process  (hand  working),  as  practised  by  M.  E.  ]VL  Martin. 

Messrs.  Orlando  Jones  and  Co..  manufacturers  of  rice  staicli,  also  placed  in  the  Ex 

We  liail  with  much  satisfaction  these  attempts  to  introduce  into  use  as  alimentarv 
substances,    preparations   of   gluten.      No   one  has   hitherto   succeede^'i^  makTni  ?n 
Il-ngland  macarom  and  vermicelli  equal  to  the  Italian  pastes- for  altho^^t^^^^^^^ 
made  article  presented  a  tolerably  Jood  appearance  it  Sn'/n  ^    1     ^  •  1      ^"«^^.^^- 

If  welkf  eaZ'DarU  ^7?,hv'"'l'^"'?  j'^'f  "^^-^  >?«  '""■•^'"<"'  f™'"  '"%  substances. 

water  to  this,  we  remove  the  vp,<«p1  frnm  ti.^  «.«    1         ^  li.     ,.  V,  »  »""««  more 

^i       i*    1  u  J  M         ,    .  *^^»6i  ii^ora  tne  nre.  decant  the  liauor.  fi  ter  it  rwisa  snl. 

phuretted  hydrogen  through  it  to  spnamfo  +!,/»  1^0  i   *u      iiV  "4""^,  "lur  u,  pass  sui- 

the  liauor  as  much  as  no,,iKlo  «  f^P  I  u      •    ^^'^'  ^^^"  ^^*^''"  "♦'■^'''^'  ^'"^  concentrate 

must  TfinSlv  evaporat^^^^^  ^"'"'"^.  "P*'"  *^^'  ^'-^ndbath.     What  remains 

musi  DC  nnaiiy  evaporated  within  the  receiver  of  the  a  r  pump.     Glycerine  thus  nrP 

pared  is  a  transparent  liquid,  without  colour  or  smell,  and^of  a^syruprcon  Le,"ce  ^  f i 
has  a  very  sweet  taste.  Its  specific  gravity  is  1-27  at  the  temperatu  e^  of  60-  Whe„ 
hrown  upon  burning  coals,  it  takes  fire  and  burns  like  an  oiL^  Water  combines  with 
It  m  almost  all  proportions;  alcohol  dissolves  it  rpa,i;i,r .  «:/ •  ".'V^'^  *^''"''''"^^  ^itli 
oxalic  acid;  and'acc^rding  ioYo.el^'l^^X^,'),:^^  ^^^^ 

same  way  as  it  does  starch      Ferment  or  yeast  does  not  affect  it  in  any  de^'rcS^ 
Its  constituents  are.  carbon  40,  hydrogen  9,  oxygen  51.  in  100  ^       ° 

The  employment  of  glycerine  as  an  application  in  the  treatmeilt  of  deafness  and  also 
for  other  purposes  as  a  medicinal  agent,  has  given  rise  to  enquiries  on  tiie  subject,  oa 


GOLD. 


939 


which  account  a  few  practical  remarks  may  probably  be  interesting  to  some  of  our 
readers. 

Glycerine  is  one  of  the  products  of  the  saponification  of  fat  oils.  It  is  produced  in 
large  quantities  in  the  soap  manufactories  in  a  very  impure  state,  being  contaminated 
with  saline  and  empyreumatic  matters,  and  having  a  very  strong  disagreeable  odour. 
In  order  to  obtain  glycerine  from  th*is  source,  the  residuary  liquors  are  evaporated  and 
treated  with  alcohol,  which  dissolves  out  the  glycerine.  The  alcohol  having  been 
separated  by  evaporation,  the  glycerine  is  diluted  with  water,  and  boiled  with  animal 
charcoal.  This  process  must  be  repeated  several  times,  or  until  the  result  is  sufficiently 
free  from  smell.  It  is,  however,  extremely  difficult  to  obtain  pure  glycerine  from  this 
source,  on  account  of  the  nature  and  condition  of  the  ingredients  usually  employed  in 
making  soap,  which  it  is  almost  impossible  to  deprive  of  rancid  odour. 

The  best  method  of  obtaining  glycerine  for  medicinal  purposes  is  to  evaporate  the 
water  used  in  making  emplastrura  plumbi.  When  the  oil  employed  is  fresh,  and  the 
process  is  carefully  conducted,  the  result  is  easily  made  fit  for  use,  and  is  almost  without 
odour.  Any  lead  with  which  it  may  be  contaminated  is  separated  by  passing  a  stream 
of  sulphuretted  hydrogen  through  it  when  in  a  dilute  state.  The  excess  of  gas  escapes 
during  the  process  of  evaporation.  If  requisite,  it  may  be  boiled  with  animal  charcoal, 
filtered,  and  evaporated.  The  specific  gravity,  when  reduced  to  the  proper  consistence, 
is  1-27. 

It  is  now  about  twelve  months  since  an  announcement  appeared  in  the  medical 
journals,  respecting  a  new  cure  for  deafness,  discovered  by  Mr.  Yearsley.  The  remedy 
was  reported  to  be  perfectly  simple,  remarkably  safe  and  very  effectual.  Several  papers 
by  Mr.  Yearsley  appeared  in  the  Lancet  during  July  and  August,  1848;  and  from  the 
statements  therein  contained,  it  appeared  that  the  novelty  consisted  in  the  insertion  of 
a  piece  of  moistened  cotton  wool  into  the  ear  in  a  particular  manner.  In  answer  to 
the  intimation  that  he  "  had  not  so  fully  described  the  modus  operandi  as  to  enable 
others  to  adopt  it  with  more  than  a  mere  chance  of  success,"  Mr.  Yearsley  observes 
"  in  answer,  I  have  only  to  say,  that  the  experience  of  several  years  has  taught  me  that 
it  is  impossible  to  convey  to  others,  in  words,  such  explicit  directions  as  shall  enable 
them  to  manipulate  with  any  degree  of  certainty.  In  fact,  it  was  on  this  account  that 
I  have  so  long  held  back  from  publishing  any  account  of  the  remarkable  fact  I  had 
observed  in  my  practice." 

GNEISS,  is  the  name  of  one  of  the  great  mountain  formations,  being  reckoned  the 
oldest  of  the  stratified  rocks.  It  is  composed  of  the  same  substances  as  granite,  viz. 
quartz,  mica,  and  felspar.  In  gneiss,  however,  they  are  not  in  granular  crystals,  but  in 
scales,  so  as  to  give  the  mass  a  slaty  structure.     It  abounds  in  metallic  treasures. 

GOLD.  (Eng.  and  Germ. ;  Or,  Fr.)  This  metal  is  distinguished  by  its  splendid 
yellow  colour;  its  great  density  =  193  compared  to  water  TO;  its  fusibility  at  the 
32d  degree  of  Wedgewood's  pyrometer;  its  pre-eminent  ductility  and  malleability, 
whence  it  can  be  beat  into  leaves  only  l-282,000th  of  an  inch  thick  ;  and  its  insolu- 
bility in  any  acid  menstruum,  except  the  mixture  of  muriatic  and  nitric  acids,  styled 
by  the  alchemists  aqua  regia,  because  gold  was  deemed  by  them  to  be  the  king  of 
metals. 

Gold  is  found  only  in  the  metallic  state,  sometimes  crystallized  in  the  cube,  and  its 
derivative  forms.  It  occurs  also  in  threads  of  various  sizes,  twisted  and  interlaced  into 
a  chain  of  minute  octahedral  crystals ;  as  also  in  spangles  or  roundish  grains,  which 
when  of  a  certain  magnitude  are  called  pepitas.  The  small  grains  are  not  fragments 
broken  from  a  greater  mass ;  but  they  show  by  their  flattened  ovoid  shape  and  their 
rounded  outline  that  this  is  their  original  state.  The  spec.  grav.  of  native  gold  varies 
from  13*3  to  17 '7.  Humboldt  states  that  the  largest  pepita  known  was  one  found  in 
Peru  weighing  about  12  kilogi-ammes  (26^  lbs.  avoird.);  but  masses  have  been  quoted 
in  the  province  of  Quito  which  weighed  nearly  four  times  as  much. 

Another  ore  of  g(»ld  is  the  alloy  with  silver,  or  argental  gold,  the  electrum  of  Pliny, 
so  called  from  its  amber  shade.  It  seems  to  be  a  definite  compound,  containing  in  100 
parts,  64  of  gold  and  36  of  silver. 

The  mineral  formations  in  which  this  metal  occurs  are  the  crystalline  primitive  rocks, 
the  compact  transition  rocks,  the  trachytic  and  trap  rocks,  and  alluvial  grounds. 

It  ftever  predominates  to  such  a  degree  as  to  constitute  veins  by  itself.  It  is  either 
disseminated,  and  as  it  were  impasted  in  stony  masses,  or  spread  out  in  thin  plates  or 
grains  on  their  surface,  or,  lastly,  implanted  in  their  cavities,  under  the  shape  of  fila. 
ments  or  crystallized  twigs.  The  minerals  composing  the  veins  are  either  quartz,  calc- 
spar,  or  sulphate  of  baryta.  Tlie  ores  that  accompany  the  gold  in  tliese  veins  are  chiefly 
iron  pyrites,  copper  pyrites,  galena,  blende,  and  mispickel  (arsenical  pyrites). 

In  the  ores  called  auriferous  pyrites,  this  metal  occurs  either  in  a  visible  or  invisible 
form,  and  though  invisible  in  the  fresh  pyrites  becomes  visible  by  its  decomposition  ;  as 
the  hydrated  oxide  of  iron  allows  the  native  gold  particles  to  shine  forth  ou  their  reddish- 


940 


GOLD. 


W 


II 


ThsZlZ^''7!?I^'Z  Tu  ^'■'"T  "il^"^  °^^y  *=«"^^^^"^^  ^-^^y  ^^e  five  rr.Jionlh  part 
nrort .  r=c^  r  Ra^'nelsberg  in  the  Hartz.     In  that  state  it  has  been  extracted  with 

^:  sit  anlltt  tLtrtsufXeT'^  "^^^^"^^'  ^^"^^"^^  ^^'^^  '''  '^''  ^^  ^^  ^^^ 

cr?f.i  ^""T  TT  /^'  P'-'^il've '''*^^'  disseminated  in  small  grains,  spangles,  and 
crjsta  s.     Brazil  allords  a  remarkable  example  of  this  species  of  iold  mine.     Beds  of 

VirRYca"wh^h"fo?mTrrr'''"^  '^^"'  ^"  ^^^  ^'-^^^  ^^  ''''^^^  '^  leagues  beyond 

45^  ^-t-  ¥^^^-  ^^?::;:l:^^S5.i:t!:.^  --^  --^^^^  - 

its  tr^.  ^n'l  IT'     T  ?^'^''''^^  ^"  *">*  secondary  formation,  but  pretty  abundantly  in 

;r^  thl=^^tLs^^:;K:t^«^ '''''-'  ^^^^^"^  ^"^^-^^^  -'^^ 

nvWt''/.  n^rffn^'  Tr'   f  """"."'y  ^"'^  Transylvania,  composed  of  tellurium,  silver 
o^^rchne  i'r  r.  I  ''  '"'  and  native  gold,  lie  in  masses  or  powerful  veins  in\  rock 
?old  ore  of  K^ii^Aprr^r^V^'^K^P"  ^"^ordinate  to  it.      Such  is  the   locality  of  the 
!?ob,hTv  ?Lr  o?  fh       ^.'.  ""^  Telk-ebanya,  between  Eperies  and  Tokay  in  Hungary,  am 
^enen  'n  al^^^^  '[ ^^P"^*^^'  Felsobanya,  &c.,  in  Transylvania ;  an^arr'ange- 

of  SnaxuaL  of  RP?I      \\7^^^  ""T-^'r^  '"^  Equatorial  America.     The  auriferous  veins 
annZTZT'  ."^^^  ^^"^^'  ""^  Villalpando,  are  similar  to  those  of  Schemnitz  in 

l"e  rocks'  thev  ,r«?"  "^  Vk  ^"'^'.'  P"^'''°"'  '^'  "^^"''^  ^^  ^^»«  <^'''  they  include,  and  of 
dencTsof   heV;,irnrv?^  «'^  mineralogists  with     he  evi- 

minp!  nf  n^  -^  volcanic  fire.     Breislak  and  Hacquet  have  described  the  gold 

the"  achy'es  wi  ^hTrm  tT'''  ^"  ^^  "^^^^  ^'  ^"  ^"^^'"^  -'--•  I'is  certai^  fh^ 
alrnr  u&a^^^  eluding  gold,  are  now 

?ran%.  ^ana  are  rich  fn  tfr'' r'  ^'''!'^''''  ^^'"^  them,  which  in  Hun.ar/and 
the  ";ichvte  offh.  Fnl  ^  auriferous  deposites;  for  gold  has  never  been  found  in 
of Viver^ne.  al   of  whf  h''^  mountains    of  the  mountains  of  the  Vicentin,  of  those 

l^^f^Lri^.^^^^  !:rri;K.:::r^-ischia  it 

trJ1.e^%7:roriSd'ent  v^Sicr'"-^^^^^  ^^  ''  '''  ^  ^^^^  ^^ ^^ 
Gold  IS,  however,  much  more  common  in  the  alluvial  grounds  than  amon-  the  nrimJ 
t,ve  and  pyrogenous  rocks  just  described.  It  is  found  disseminated  u^er^he  fon,  of 
e'nedam-7n\h'  '^''"°"''  a'-gillaceous,  and  ferruginous  sands  of  certain  p^aTns  and  riers 
t'^porir^y  floodT  """^""^^  '"^^^"'  ^^  ^'^  ^^^^«"  ''  '^^  ^^^-^  -^  -^^er  storms  Inc 
hJlht^V'T"  supposed  that  the  gold  found  in  the  beds  of  rivers  had  been  torn  out 
pLn  L  h""?  u""""-  '^^  •'^"'"'  ^"'^  P^''"^^'^^  '^^^'>  ^hich  they  traverse.  Some  have 
^redourmelai  '  The"  loM  in'ihe'  Tr  ^^^'^^-^  «treams,'for  the  na.-ive  heTof  Z 
arthey  gnJe  aion^    ThL  nn  '""'''  ^""7"*'  '"^  '^"^  ^'"^""'^^  ^^'^^^^ed  by  the  waters 

Guettard    Rob  ta/f*  Sn T        '  ^"-f  t/'i  ^'  ^'St  by  Delius,  and  supported  bv  Deborn, 
D^ain?.nnt  r  '        \^'  ^""'^ ''  ^^""^^^  ^P^'^  J"st  observations.     1.  The  soil  of  these 

plains  contains,  frequently,  at  a  certain  depth  and  in  several  spot,    snan-les  of  Iold 

more  gold  after  storms  of  rain  upon  the  plains  than  in  any  other  circumstances      ^Tt 
happens  almost  always  that  gold  is  found  among  the  sands  of  rivers  on^V  in  a  ver/'cil 
d,d  uli    mlt.'r'"'  7  '''?'^'"^,  ""^^  "^"«  ^^^-  '^^^^  <=ease  to  artbrd  gold;  tlou%" 
source  onhe  r?eV^''V^ '"'^^^ ',^'"'^       ^^""^'^  ^^  ^'^""^   more  abundan.ly    ."r  "he 

rn^'tol'^^^unro^wil't^hlpo"  tITtI^'o  ^^^  f''"" .?''Tl  T  ''''  ^^^^^^  ^-- 
aiore  and  consenupntk  fir        ,V    ^  ^  T  ""<*  a^^^ds  gold  only  below  the  Lagu  Ma-- 

river,  as  i.  fl„ws  a„K,„g  Ae  moluijrf  S  yrriUluT^oVoU ''l.:.''^     .^'"ioa  of  ,h« 
into  the  plain  at  Siejer,  till  its  embouchure  i"'hrDa„ube  hslnih  '^  "-r'^"" 

an.l  are  even  rich  enc.ush  to  be  washed  with  profit  ""  """f^™"^ 

The  greater  part  of  the  auriferous  sands,  in  Euronp    A«;.    ar-  ■    . 

are  black  or  red,  and  onsequently  ferru"iious  ■  a  r^™»  b  kI  ^^""''  ""^  Ainerica 
geological  no'iti.m  or  alluvial  sold/ iMNaZne  Un  I  rih^^^^^^^  crcamstance  in  th. 
ginous  .rounds  is  due  to  the  decon,po"u'rof  ^S?^™,  3"' ^'if '■".IlL ""'■'^'^^'■™■ 
«.ad  occurring  in  Hungary  atoos.  ahiSys  in  .be  aeiglrhU'^f^he  bel%?" -^.1^ 


GOLD. 


941 


and  the  petrified  wood  covered  with  gold  grains,  found  buried  at  a  de,,th  of  55  yards  in 
clay,  in  the  mine  of  Vorospatak  near  Abrabanya  in  Transylvania,  might  lead  us  to  pre- 
sume that  the  epoch  of  the  formation  of  the  auriferous  alluvia  is  not  remote  from  that 
of  the  lignites.  The  same  association  of  nold  ore  and  fossil  wood  occurs  in  South 
America,  at  Moco.  Near  the  villasie  of  Lloro,  have  been  discovered  at  a  depth  of  20 
feel,  large  trunks  of  petrified  trees,  surrounded  with  fragments  of  trap  rucks  interspersed 
with  spangles  of  gold  and  platinum.  But  the  alluvial  soil  affords  likewise  all  *he  cha- 
racters of  the  basaltic  rocks;  thus  in  France,  the  Ceze  and  the  Gardon,  auriferous 
rivers,  where  they  atl'ord  most  gold,  flow  over  ground  apparently  derived  from  the 
destruction  of  the  trap  rocks,  which  occur  in  situ  higher  up  the  country.  This  fact  had 
struck  Reaumur,  and  this  celebrated  observer  had  remarked  that  the  sand  which  more 
immediately  accompanies  the  gold  spangles  in  most  rivets,  and  particularly  in  the  Rhone 
and  the  Rhine,  is  composed,  like  that  of  Ceylon  and  Expailly,  of  black  protoxyde  of  iron 
and  small  grains  of  rubies,  corindon,  hyacinth,  &c.  Titanium  has  been  observed  more 
recently.  It  has,  lastly,  been  remarked  that  the  gold  of  alluvial  formations  is  purer  than 
that  extracted  from  rocks. 

Principal  Gold  Mines, 

Spain  anciently  possessed  mines  of  gold  in  regular  ^eins,  especially  in  the  province  of 
Asturias ;  but  the  richness  of  the  American  mines  has  made  them  to  be  neglected. 
The  Tagus,  and  some  other  streams  of  that  country,  were  said  to  roll  over  golden  sands. 
France  contains  no  workable  gold  mines ;  but  it  presents  in  several  of  its  rivers  auri- 
ferous sands.  There  are  some  gold  mines  in  Piedmont ;  particularly  the  veins  of  aurife- 
rous pyrites  of  Macugnagna,  at  the  foot  of  Monte  Rosa,  lying  in  a  mountain  of  gneiss; 
and  although  they  do  not  contain  10  or  11  grains  of  gold  in  a  hundred  weight,  they  have 
long  defrayed  the  expense  of  working  them.  On  the  southern  slope  of  the  Pennine  Alps, 
from  the  Simplon  and  Monte  Rosa  to  the  valley  of  Aoste,  several  auriferous  districts  and 
rivers  occur.  Such  are  the  torrent  Evenson,  which  has  afforded  much  gold  by  washing; 
the  Oreo,  in  its  passage  from  the  Pont  to  the  Po;  the  reddish  grounds  over  which  this 
little  river  runs  for  several  miles,  and  the  hills  in  the  neighborhood  of  Chivasso,  contain 
gold  spangles  in  considerable  quantity. 

In  the  county  of  Wicklow,  in  Ireland,  a  quartzose  and  ferruginous  sand  was  discovered 
not  long  aoo,  containing  many  particles  of  gold,  with  pepit as  or  solid  pieces,  one  of  which 
weighed  22  ounces.     No  less  than  1000  ounces  of  gold  were  collected. 

There  a-e  auriferous  sands  in  some  rivers  of  Switzerland,  as  the  Reuss  and  the  Aar. 
In  Germaiij  no  mine  of  gold  is  worked,  except  in  the  territory  of  Salzburg,  amid  the 
chain  of  mountains  which  separates  the  Tyrol  and  Carinthia. 

The  mines  of  Hungary  and  Transylvania  are  the  only  gold  mines  of  any  importance  in 
Europe  ;  they  are  remarkable  for  their  position,  the  peculiar  metals  that  accompany  them, 
and  their  product,  estimated  at  about  1430  pounds  avoird.  annually.  The  principal  ones 
are  in  Hungary.  1.  Those  of  Konigsberg.  The  native  gold  is  disseminatetl  in  ores  of 
sulphuret  of  silver,  which  occur  in  small  masses  and  in  veins  in  a  decompo>in2  feldspar 
rock,  amid  a  conglomerate  of  pumice,  constituting  a  portion  of  the  Irachytic  formation. 
2.  Those  of  Borson,  Schemnitz.  And,  3.  of  Felsobanya ;  ores  also  of  auriferous  sulphu- 
ret of  silver,  occur  in  veins  of  sienite  and  greenstone  porphyry.  4.  Those  of  Telk©- 
banya,  to  the  south  of  Kaschau,  are  in  a  deposile  of  auriferous  pyrites  amid  trap  rocks 
of  the  most  recent  formation. 

In  Transylvania  the  gold  mines  occur  m  veins  often  of  great  magnitude,  6,  8,  and  some- 
times 40  yards  thick.  These  veins  have  no  side  plates  or  wall  stones,  but  abut  without 
intermediate  gangues  at  the  primitive  rock.  They  consist  of  carious  quartz,  ferriferous 
limestone,  heavy  spar,  fluor  spar,  and  sulphuret  of  silver.  The  mine  of  Kapnik  deserves 
notice,  where  the  gold  is  associated  with  orpiment,  and  that  of  Vcrospatak  in  eranite 
rocks ;  those  of  Ofl'enbanya,  Zaiatna,  and  Nagy-Ag,  where  it  is  associated  with  lellu 
num.     The  last  is  in  a  sienitic  rock  on  the  limits  of  the  trachyte. 

In  Sweden,  the  mine  of  Edelfors  in  Smoland  may  be  mentioned,  where  the  g(»ld 
occurs  native  and  iu  auriferous  pyrites ;  the  veins  are  a  brown  quartz,  in  a  mountain 
of  foliated  hornstone. 

In  Siberia,  iiative  gold  occurs  in  a  hornstone  at  Schlangenberg  or  Zmcof,  and  at 
Zmeino  gursk  in  the  Altai  mountains,  accompanied  with  many  other  ores. 

The  gold  mine  of  Berezof  in  the  Oural  mountains  has  been  long  known,  consisting  of 
partially  decomposed  auriferous  pyrites,  disseminated  in  a  vein  of  greasy  quartz.  About 
1820,  a  very  rich  deposit  of  native  gold  was  discovered  on  the  eastern  side  of  the  Oural 
mountains,  disseminated  at  some  yards  depth  in  an  argillaceous  loam,  and  accompanied 
with  the  debris  of  rocks  which  usually  compose  the  auriferous  alluvial  soils,  as  greensttine, 
serpentine,  protoxide  of  iron,  corundum,  <fec.  The  rivers  of  this  district  possess  auri- 
ferotia  sands.    The  product  of  the  gold  mines  of  the  Oural,  in  1845,  was  11,808  pounds 


942 


I 


I 


,  I 


GOLD.  • 


^m^!^i^S^;lJr^J^  P^^;  ^  of  Siberian  1845.  87,576  pound,  an. 

believed  that  in'  1847  and  1849  theTeld  wi^'^^iil  ^'°  'u"'^'^""^  ^^  ^^  ^^'-  ^^  i« 
materially  fallen  off.  as  it  is  stated  in  AW.  ^  j  'I'"  ^^l^^""'  ^"'  '^  "^"^^  «i"ce  l.ave 
exceed  20.000  pounds  troy  ''*  ^'''^''''  *^*^  ^^^«  3'ield  in  1851  will  not 

and;wt:;r^^^^^^^  -  .any  .ine,  stream,  rivers. 

such  golden  sands,  that  it  was  supposed  to  rnntttr'*?;'"'*-"-  "''f  ?^  ^y^'*'  •*o"*^J  «ve; 
But  these  deposits  are  now  poor  and  fn  J  h  t""^^  the  origm  of  the  wealth  of  CrcBsus. 

Borneo,  the  ^^ilippioes.TnS^re'ofhf  Snds  ^ftt^^^^^^^  '""^'^  ^"•"^^-' 

gold  mines.      Those  of  Borneo  are  woL  i  k     n     ^^f  .''^^'^P  Archipelago,  are  rich  in 
western  coast,  at  the  foot  of  a  chair7of      i^-^^'^  ^^'"-"^  '°  *"  ^""^'^^  ^''^  on  the 
Little  or  no  ffold   rnm       •  ?     5  volcanic  mountains. 

place  their  fortune  in  t^e'asure   and^Jo^!  toT   f'"'   ^T''   '■''  «"^^'^«  inhabitants 

i!^umerous  gold  mines  occur  on  ?h.  *         ,      ""^'^  VP  *^**  precious  metal 
the  Oundes.  a^ovin^of  Lhde  TwL\"^^rP^^  f,  l'^'  ^'^^^  «^  ^''«  Dallas  mountains  in 
very  crumbUng  reddish  granite  ^        ^^'  '"^  ^l"**"'^  ^^^'^  ^^^^^  traverse  a 

the^'Sidenr   1^^  |o^fwh?crrfH<l'/tin 'h^'''''^P''•t'^"  ^^  '^'  S«'^  Po— ^  by 
showing  that  the  mLl  is  Sined  Ku  ^^  the  market  is  alw^s  in  dust^ 

lected  m  the  north  of  that  coSnt  ^w'  '"^  l^'  ^ P?'-^^  ^^«'^^-      ^""«    '^  ''  is  coU 
the  quantity  of  gold  they  produce      '  """  ^''"'*  ^"^"'^'  °"^^  ^'^  remarkable  for 

trans;o^1^^^^^^^^  1.e  negroes 

prisoners  bound  with  golden  c^ainf  ambassadors  of  Cambyse.  all  their 

^,  rS  w^tt'taTtt'ltir?''^!"^  ''  ^^'^  «^"*^  «^  *^«  ^--^t  desert  of 
Palms.  The  gold  ^curs  in  snan.T'  ^T  i^'**  """"^^^  «^  '^^  Senegal  to  the  Cape  of 
bedofrivulets,^andah;ay    inaTrt"^^^^^^^  «"f^-  f '»-   --th.  iS  the 

-u  the  soil  to  a  depth  of  about  40  fee^t  unLnno^  7  k'"'"'  P^^^'"  ^'^^  "^^'"^^^^  <^'g  ^^^lls 
any  vein;  nor  do  they  construe?  a  ^llZ^^R  ^^.T  P'T'  '^'^"^^  ^^  not  follow 
gold  from  the  earthy  iatters  ^        •^-    "^^  ^^P^^ted  washings  they  separate  the 

an  J  Al^e^:.  t^tt  l^t?  ^tht,  K^TiKcf  ""'V'  T'''  *«  ^^^^  ^-• 
tweit-m(^  Sllle^;:^^!::^^^  Z^l  ^outL'::l'L.t,  between  the 

in  veins.     See  California,  infra.  '      "^  '"  ^^'^  ^^^  «^  "^'^rs ;  more  rarely 

There  is  little  gold  in  the  northern  part  of  America     Tn  isin 
weighing  28  pounds,  was  found  in  th4  *.ravel  nTu  nT'thJ        ,  '  ^T""^  «f  alluvial  gdd, 
Lebanon,  in  North  Carolina  ^  P      ""^  *^^  ''''^*''^'^  «^  Rockhole,  district  of 

regl'^hl^i^l^tJXS?*^^  and  Chili,  were  the 

Exhibition  was  one  who  forwarded  a  lump  of  Inld  n'  •  "^"  "^J""^  ^  **^*^  ^''^a* 

brought  up  from  a  deep  mine  on  the  back  oFa  Lfni    .        ^^J^^""?  ^  cwt,  which  was 
the  surface.  ^  °  ^''^  ^'*^''  **^  *  »n'°er,  from  a  depth  of  45  yards  beneath 

nume?oS'11hi?trntr;,"wLEtrin^^^^^^^^  ^"  the  argentiferous  veins,  so 

Silver.     The  silver  of  tfc  I  gentiCuTo  e^^^^^^  f '"''""^^  ""^^•''  *»^«  'Article 

weight  of  gold;  the  annual  pfoXct  Tthe  mfn\.f  ^"*''"'''*f  T*^'°"  «°«  ^BOth  of  its 
pounds  avoirdupois.  ^  ''^  ^^"^  ""'^^  *^'°g  valued  at  from  2640  to  3300 

t^a?e^?eVer^oJ'^etV„Ii:rl^'  ^^P"'""='^  -  ^"■<'  "''-  '-  «-■=„;  .hey 

ovef  LoWe,."3,"'  ""  """"'"  °'  '^^ ■  *»  '»  degrees  north  of  «,e  line,  flow 

Peru  is  not  rich  in  e-old  orpa      Tn  ♦»,/, 
is  mined  in  veins  of  greLy  q^r^z  IVeltTr'T^  of  Huailas  and  Pataz,  this  metal 
primitive  rocks.     Tl.!  mi/es''cXi  pZHtltZt  o7orf  "7"  ^P'^-"''"  '— 
containing  a  great  quantity  of  gold.  ^^  °^  "'""  ^"^  ^^PP^r  oxides, 


GOLD. 


943 


All  the  gold  furnished  by  New  Grenada  (New  Columbia)  is  the  product  of  washings 
established  in  alluvial  grounds.  The  gold  exists  in  spangles  and  in  grains,  disseminated 
among  fragments  of  greenstone  and  porphyry.  At  Choco.  along  with  the  gold  and 
platinum,  hyacinths,  zircons,  and  titanium  occur.  There  has  been  found,  as  already 
stated,  in  the  auriferous  localities,  large  trunks  of  petrified  trees.  The  gold  of  Antioquia 
is  20  carats  fine,  that  of  Choco  21,  and  the  largest  lump  or  pepita  of  gold  weighed  about 
27^  pounds  avoirdupois.     The  gold  of  Chili  also  occurs  in  alluvial  formations. 

Brazil  does  not  contain  any  gold  mine,  properly  so  called ;  for  the  veins  containing 
the  metal  are  seldom  worked. 

It  is  in  the  sands  of  the  Mandi,  a  branch  of  the  Rio-Dolce,  at  Catapreta,  that  the  auri- 
ferous ferruginous  sands  were  first  discovered  in  1682.  Since  then  they  have  been 
found  almost  everywhere  at  the  foot  of  the  immense  chain  of  mountains,  which  runs 
nearly  parallel  with  the  coast,  from  the  5th  degree  south  to  the  80th.  It  is  particularly 
near  Villa  Rica,  in  the  environs  of  the  village  Cocaes,  that  the  numerous  washings  for 
gold  are  established.  The  pepitas  occur  in  different  forms,  often  adhering  to  micaceous 
specular  iron.  But  in  the  province  of  Minas  Geriies,  the  gold  occurs  also  in  veins,  in 
beds,  and  in  grains,  disseminated  among  the  alluvial  loams.  It  has  been  estimated  in 
annual  product,  by  several  authors,  at  about  2800  pounds  avoirdupois  of  fine  metal. 

We  thus  see  that  almost  all  the  gold  brought  into  the  market  comes  from  alluvial 
lands,  and  is  extracted  by  washing. 

The  gold  coin  of  the  ancients  was  made  chiefly  out  of  alluvial  gold,  for  in  these  early 
times  the  raetallurgic  arts  were  not  sufficiently  advanced  to  enable  them  to  purify  it.  The 
gold  dust  from  Bambouk  in  Africa  is  of  22J  carats  fine,  and  some  from  Morocco  is  even 
23. 

The  gold  of  Giron,  in  New  Grenada,  is  of  23f  carats ;  being  the  purest  from  America. 
**  For  those  who  traffick  in  gold,"  says  Humboldt,  "it  is  suflicient  to  learn  the  place  where 
the  metal  has  been  collected,  to  know  its  title." 

Cali/ornian  Gold  Mines. — The  accident  which  first  revealed  the  golden  treasures  of  the 
Boil  of  California  is  thus  related  by  a  writer  of  Article  VII.  of  the  Quarterly  Review, 
for  September,  1852.  Captain  Suter,  the  first  white  man  who  had  established  himself 
in  the  district  where  the  Americanos  joins  the  Sacramento,  having  erected  a  saw-mill  on 
the  former  river,  whose  tail  race  turned  out  to  be  too  narrow,  took  out  the  wheel,  and 
let  the  water  run  freely  off.  A  great  body  of  earth  having  been  carried  away  by  the 
torrent,  laid  bare  many  shining  yellow  spangles,  and  on  examination,  Mr,  Marshall,  his 
surveyor,  picked  up  several  little  lumps  of  gold.  He  and  Captain  Suter  then  com- 
menced a  search  together  and  gathered  an  ounce  of  the  ore  from  the  sand  without  any 
difficulty  ;  and  with  his  knife  the  captain  picked  out  a  lump  of  an  ounce  and  a  half  from 
the  rock.  A  Kentuckian  workman  employed  at  the  mill  had  espied  their  supposed 
secret  discovery,  and  when  after  a  short  absence  the  gentlemen  returned,  he  showed  them 
a  handful  of  the  glittering  dust.  The  captain  hired  a  gang  of  fifty  Indians,  and  set 
them  to  work.  The  news  spread,  but  the  announcement  of  the  discovery  was  received 
with  incredulity  beyond  the  immediate  neighbourhood.  But  presently  when  large  and 
continuous  imports  of  gold  from  San  Francisco  placed  the  matter  beyond  doubt,  there 
ensued  such  a  stir  in  the  States,  as  even  in  that  go-a-head  region  is  wholly  without  pa- 
rallel :  numbers  of  every  age  and  of  every  variety  of  occupation  pushed  for  the  land 
of  promise.  Many  were  accompanied  by  their  families,  and  most  under  the  excitement 
of  the  hour  overlooked  their  physical  unfitness,  and  their  inability  to  procure  necessaries. 
The  waters  of  the  Humboldt,  from  their  head  to  their  "  sink,"  a  space  of  nearly  300 
miles,  are  in  the  dry  season  strongly  impregnated  with  alkali :  and  it  was  here  that  they 
first  began  to  faint.  Some  died  from  thirst,  others  from  ague,  others  fell  beneath  the 
burdens  they  attempted  to  carry  when  their  last  animal  dropped  into  the  putrid  marsh, 
which  grew  thicker  at  every  step.  Beyond  the  "  sink"  the  diminislied  bands  had  to 
encounter  sixty  or  seventy  miles  of  desert,  where  not  a  blade  of  herbage  grew,  and  not 
a  drop  of  pure  water  could  be  procured ;  and  those  who  pushed  safely  through  this 
ordeal  had  still  to  ascend  the  icy  slopes  of  Sierra  Nevada,  when  the  rig<»urs  of  winter 
were  added  to  all  other  difficulties.  At  different  points,  one  being  almost  in  sight  of  the 
golden  land,  overwearied  groups  had  formed  encampments,  in  case  perhaps  some  help 
might  reach  them.  It  is  to  the  credit  of  the  settlers  that  on  hearing  this,  they  strained 
their  resources  to  the  utmost  to  afford  relief.  Yet  when  all  was  done,  a  sick,  destitute, 
most  wretched  horde  of  stragglers,  was  all  that  remained  of  the  multitude,  who,  full  of 
hope  and  spirits,  had  commenced  the  prairie  journey. 

Enterprise  and  energy  have  now  overcome  or  smoothed  the  worst  difficulties  of  the 
route.  A  great  central  railroad  has  been  projected,  and  will  probably  at  no  distant 
time  be  formed. 

To  this  time,  the  stream  of  life  flowing  into  California  has  kept  continually  increasing. 
Upwards  of  20,000  souls,  and  about  50,000  animals,  forming  a  scattered  train  of  about 
700  miles  in  length,  passed  Fort  Kearney  in  the  month  of  May  last.    In  this  multitude 


944 


GOLD. 


'•'I 


fi 


the  strangest  contrasts  were  seen  ;  ladies  on  spirited  steeds,  in  full  Bloomer  costume  or 
m  the  more  modest  equestrian  habit  to  whicli  we  are  accustomed,  and  men  eallantlv 
mounted  with  Kossuth  hat  and  plume,  swept  by  the  humble  pedlar  driving  ass  or  mule 
and  toil-worn  women,  leading  their  chUdren  by  the  hand.     Some  had  their  little  stock 
of  provisions  strapped  on  their  backs  ;  others  trusted  to  hand-carts  and  wheelbarrows. 

"  The  journey  would  be  pleasant,"  writes  one  of  the  company,  "  but  for  the  vast  number 
of  graves  along  the  road.  There  are  about  80  graves  to  100  miles  so  far-  that  is 
new  ones,  the  old  ones  are  nearly  obliterated,  and  their  places  no  longer  known  by  man." 
This  passage  depicts  well  the  recklessness  with  which  in  the  States  life  is  squandered  in 
the  pursuit  of  gain.  By  sea,  the  arrivals  are  even  more  numerous  ;  upwards  of  10.000 
landed  at  the  port  of  San  Francisco  in  May.  and  about  an  equal  number  in  June.  In 
the  first  SIX  months  of  the  year  10.000  Chinamen  had  arrived  to  claim  part  in  the  golden 
harvest;  400  more  followed  m  the  first  fortnight  of  July,  and  eighteen  women,  in  the 
costume  of  the  Celestial  Empire,  had  come  infrom  Hong  Kong      The  population  of 

^nn^nV^f^  f^"^  1?'^^^  ^^  *^^  Commencement  of  the  present  year  f  it  will  be 
300,000  by  Its  close.  Already  the  seaboard  of  California  is  brought  within  a  month's 
passage  ot  England ;  and  its  exports  now  amount  in  value  to  one  fourth  the  exports  of 
the  United  Kingdom.  The  produce  of  California  up  to  the  10th  of  January,  1851,  is 
stated  by  Mr.  Scheer  at  about  62  millions  sterling;  but  these  figures  taken  from  a  gold 
circular  published  at  San  Francisco  must  be  much  too  high.  From  35  to  40  millions 
would  probably  be  nearer  the  mark.  17,339,544/.  is  the  amount  for  last  year,  as  care- 
fully computed  by  Mr.  Birkmyre.  See  Ihnes,  May  21.  The  exports  this  year  are 
known  to  have  been  during  the  three  first  months,  3,900,000  doUais  more  Uian  those  of 
the  three  corresponding  months  of  the  preceding  year.  1851. 

Jieport  of  Deposits  of  Gold  from  California,  at  the  several  Utu  ted  States  Mints, 


in  1848 
1849 
1850 
1851 


Hussey  &  Co  .'a  Circular,  San  Francisco,  July  30,  1852. 


dollars. 

-    44,177 

6,147,509 

36,074.062 

55.938,232 


Australian  Gold  Mi7tes.— The  discovery  of  a  great  gold  field  in  Australia  to  the 
westward  of  Bathurst,  about  150  miles  liom  Sydney,  was  officially  made  known  in 
Great  Britain,  by  a  despatch  from  Sir  C.  A.  Fitzroy  to  Earl  Grey,  on  the  18th  Sep- 
tember, 1851,  many  persons  with  a  tin  dish  having  obtained  from  one  to  two  ounces  pS 
day.  On  the  25th  of  May,  he  writes  that  lumps  have  been  obtained  varyino-  in  wei<'ht 
from  an  ounce  to  four  pounds.  On  the  29th  May,  he  writes  that  gold  has  "been  foJnd 
in  abundance,  that  people  of  every  class  are  proceeding  to  the  locality,  that  the  field 
IS  rich,  and  from  the  geological  formation  of  the  country  of  immense  area  By 
assay  the  gold  was  found  to  consist  of  91.1  of  that  metal  and  about  8.333  of  silver  with 
a  little  base  metal ;  or  of  22  carats  in  fineness.  July  17th,  a  mass  of  gold  wei'diino" 
106  pounds  was  found  imbedded  in  the  quartz  matrix,  about  53  miles  from  Bathur^t*^ 
and  much  more,  justifying  the  anticipations  formed  of  the  vast  richness  and  extent  of 
the  gold  field  in  this  colony.  This  magnificent  treasure,  the  property  of  Dr.  Kerr  sur- 
passes the  largest  mass  found  in  California,  which  was  28  pounds;  and  that  in  Russia 
which  was  70  pounds,  now  in  the  museum  at  Petersburg.  One  party  of  six  persons 
got  at  the  same  time  400/.  in  ten  days,  by  means  of  a  quicksilver  machine  •  and  a  party 
of  three,  who  were  unsuccessful  for  seven  days,  obtainecl  in  five  days  more,  200  ounces  A 
royalty  of  10  per  cent,  was  ordered  to  be  paid  on  gold  in  matrix  if  found  in  Crown  lands 
and  5  per  cent,  if  found  in  private  property.  Four  armed  men  travel  in  the  carriage 
that  conveys  the  gold  from  the  diggings  to  Sydney,  accompanied  by  two  armed  con- 
stables, in  general  weekly,  or  oftener  if  required.  The  licence  fee  is  30«  a  month 
August  19th,  1851,  the  Governor  Sir  C.  Fitzroy  reports  to  Earl  Grey,  that  trold  to  the 
value  of  70,000/.  had  been  already  collected;  and  on  the  21st,  that  3,614  ozs  had  that 
morning  arrived  at  Sydney  from  Bathurst,  worth  upwards  of  12.600/. 

August  25th,  1851,  Lieutenant  Governor  C.  J.  Latrobe  announced  to  Earl  Grey  from 
Melbourne,  the  discovery  of  large  deposits  of  gold  in  that  district  of  the  colony  In  a 
second  Parliamentary  blue  book,  issued  February  3,  1852,  it  is  stated  that  79  340  ounces 
of  gold,  worth  257,855/.  Is.  had  been  previously  forwarded  to  England  ;  and  that  the  gold 
fio(s  of  the  colony  of  Victoria  rival,  if  they  do  n<.t  exceed  in  value,  the  first  discovered 
gold  fields  of  New  South  W  ales  ;  the  total  value  being  now  300,000/.  •  and  a  little  time 
attt-rwar.ls  about  half  a  million  sterling.  Mr.  E.  Hargraves.  commissioner  for  Crown 
land.-,  annomice.^  from  Bathurst,  that  no  part  of  Calif.unia  which  he  had  seen  has  pro- 
duced  gold    H)  generally  and   to  Hwh  an   extent    as  Summerhill    Creek,    the  Tiiron 


GOLD. 


945 


River  and  its  tributaries.  A  letter  from  Sir  J.  F.  W.  Herschel,  Bart.,  dated  Royal  Mint, 
London,  February  7th,  1852,  says,  *'it  is  believed  that  in  California,  gold  to  theValue  of 
18  millions  sterling  had  been  found  during  each  of  the  two  last  years;  and  prior  to  the 
discovery  of  that  gold  region,  the  whole  annual  produce  throughout  the  world  was  sup- 
posed to  be  only  about  one-fifth  of  that  amount. 

Taking  the  actual  amount  shipped  from  Melbourne  to  the  end  of  March  last,  and 
allowing  for  the  quantity  supposed  to  be  at  the  diggings,  and  waiting  shipment,  it  would 
appear  that  about  700,000  ounces  had  been  raised  in  Victoria.  At  3/.  per  oz.  this  would 
be  worth  2,100,000/.  The  licences  up  to  the  same  date  were  49,386;  equivalent  to  42/. 
105.  as  the  average  monthly  earnings  of  each  licensed  digger.  The  amount  raised  in 
New  South  Wales  to  the  end  of  March  may  be  taken  at  320,000  ounces,  and  the  value  at 
960,000/.;  being  at  the  rate  of  31/.  35.  monthly  per  individual;  probably  about  1/.  daily 
for  each  digger.  Australia  will  soon  be  supplied  with  silver  coin.  The  shipments  on 
board  (September  13)  are  understood  to  amount  to  2.000,000/.  and  estimating  the  addi- 
tional sum  taken  out  by  emigrants,  it  is  probable  that  the  value  of  the  total  quantity 
exported  equals  that  of  the  gold  received.  The  diggers  must  be  largely  benefited  by 
these  shipments  of  coin,  as  the  gold,  which  in  London  would  realize  41.  per  oz.,  has  not 
always  brought  them  3/.  The  gold  fields  discovered  in  Australia  stretch  over  1000  miles, 
in  a  south-westerly  direction  from  Moreton  district  to  Ballarat. 

Up  to  the  first  week  in  June  last,  it  is  certain  from  the  actual  exports,  that  the  total 
gold  raised  in  Australia  must  have  amounted  in  value  to  4,000,000/.  sterling;  and  the 
produce  was  still  on  the  increase.  The  number  of  diggers  at  present  hardly  reaches 
20,000.  It  seems  moderate  to  assume  that  50,000  labourers  will  be  scattered  over 
the  Australian  gold  fields  before  the  end  of  the  present  year;  and  taking  their  earn- 
ings at  only  20/.  per  month,  we  shall  have  a  yield  then  of  12,000,000/.  yearly. 

Mr.  Birkmyre  supposes  that  in  1846  there  were  raised  from, — 


North  and  South  America 
Russia        -  -  -  -  - 

Austria      .  -  -  .  . 

Piedmont,  Spain,  and  North  Germany 
Africa         .  .  -  .  . 

Borneo        .  .  -  -  . 

Ava,  Malacca  and  other  countries 


This  total  is  exclusive  of  China  and  Japan. 


£ 

-  1,301.500 

-  3,414,427 

282,750 
20,696 
203,900 
805,900 
317,519 

£  5,846  692 


f 


Metallurgic  treatment  of  gold. — The  gold  found  in  the  sands  of  rivers,  or  in  auriferons 
soils,  needs  not  be  subjected  to  any  metallurgic  process,  properly  speaking.  The 
Orpaillers  separate  it  from  the  sands,  by  washing  them  first  upon  inclined  tables, 
sometimes  covered  with  a  cloth,  and  then  by  hand  in  wooden  bowls  of  a  particular  form. 
Amalgamation  is  employed  to  carry  ofl"  from  the  sand  the  minuter  particles  of  gold  they 
may  contain.  The  people  called  Bohemians,  Ciaans,  or  Tehinganes,  who  wash  the 
auriferous  sands  in  Hungary,  employ  a  plank  with  24  transverse  grooves  cut  in  its 
surface.  They  hold  this  plank  in  an  inclined  position,  and  put  the  sand  to  be  washed 
in  the  first  groove;  they  then  throw  water  on  it,  when  the  gold  mixed  with  a  little  sand 
collects  usually  towards  the  lowest  furrow.  They  remove  this  mixture  into  a  flat  wooden 
basin,  and  by  a  peculiar  sleight  of  hand,  separate  the  gold  entirely  from  the  sand.  The 
richest  of  the  auriferous  ores  consist  of  the  native  gold  quite  visihle,  disseminated  in  a 
gangue  but  the  veins  are  seldom  continuous  for  any  length.  The  other  ores  are  auri- 
ferous metallic  sulphurets,  such  as  sulphurets  of  copper,  silver,  arsenic,  &.C.,  and  particu- 
larly iron. 

The  stony  ores  are  first  ground  m  the  stamping  mill,  and  then  washed  in  hand-basins, 
or  on  wooden  tables. 

The  auriferous  sulphurets  are  much  more  common,  but  much  poorer  than  the  former 
ores ;  some  contain  only  one  200,000th  part  of  gold,  and  yet  they  may  be  worked  with 
advantage,  when  treated  with  skill  and  economy. 

The  jjold  of  these  ores  is  separated  by  two  different  processes  ;  namely,  by  fusion  and 
amalgamation. 

The  auriferous  metallic  sulphurets  are  first  roasted;  then  melted  into  mattes,  which 
are  roasted  anew ;  next  fused  with  lead,  whence  an  auriferous  lead  is  obtained,  which 
may  be  refined  by  the  process  of  cupellation. 

When  the  gold  ores  are  very  rich,  they  are  melted  directly  with  lead,  without  pre- 
limmary  calcination  or  fusion.  These  processes  are,  however,  little* practised,  because 
they  are  less  economical  and  certain  than  amalgamation,  especially  when  the  gohl  ores 
are  very  poor. 

If  these  ores  consist  of  copper  pyrites,  and  if  their  treatment  has  been  pushed  to  the  poini 


Ir 


1: 


^- 


ii 


946 


GOLD. 


of  obtaining  auriferoQs  rose  copper,  or  even  black  copper  includln?  eold,  the  precious 
metal  cannot  be  separated  by  the  process  of  liquation,  because  the  gold,  havi^  J^more^Z 

llZ  "T""  '^'"  ^T  ^''^,'  ''"  ^'  *^"'  ^^'•^•^"y  ^""  «ff  ^y  ^^e  latter  met!'  For  these 
reasons  the  process  of  amalcamation  is  far  preferable  ror  mesc 

rZ^lr'"'''''-  ^^V"^J'!u  '^"^.^°'  '"^^•■'  ^  ''^^^  ^^'^^-^e  its  description  for  this  metal 
The  rich  ores  in  which  the  native  gold  is  apparent,  and  merely  disseminated  in  aTony 
gangue,  are  directly  triturated  with  quicksilver,  without  any  preparatory  operation.  As 
to  the  poor  o,Ts,  m  which  the  gold  seems  lost  amid  a  great  mass  of  iron,  suhhu  et  of^ 
copper,  &c.,  hey  are  subjected  to  a  roasting  before  bein^  amalgamated.  T  is  process 
seems  requisite  to  lay  bare  the  gold  enveloped  in  the  sulphurets!    Thrqmck  i  ver  with 

it  mn'v  ^n'1  ^""^'''"^  ^^  '^^  'm^""'^  r^*^"''  ^'^^  ^^^^'  '^  ^''^  f'-om  copper  and  lead,  but 
^reTtdir,r«T;''"'"'''r:r     ^'  ^^"""^   ^^  separated  from  iron  and   tin  wi  hoS 

By  cupelJation  with  lead  gold  may  be  deprived  of  any  antimony  united  with  it 
Tin  gives  gold  a  remarkable  hardness  and  brittleness;  a  piece  of  cold  ex  nosed  for 
«>me  time  over  a  bath  of  red  hot  tin,  becomes  brittle.     The  s^ame  'l  inrhkpperl^^^ 

Inv  \^'""  T'^T'/'T  '^'  ^''^"^"•■•y  ^'^  ^^'^  "^^t«^-     A  two  thousandth  pa  t  of  TxU 
inony,  bismuth,  or  lead,  destroys  the  ductility  of  -old.     The  tin   may  be  eol  rid  of  bv 
throwing  some  corrosive  sublimate  or  nitre  into  a  crucible,  containin^^  the  melte    allov 
By  the  first   acent,  perchloride  of  tin   is  volatilized;  by  the  second,%aL«/rof  potash 
forms   which  is  carried  off  in  the  resulting  alkaline  scorii.  '  siavmite  ol   potash 

silver  T^^^M  ^^  ^^VP'"7^^f  «^  amalgamation,  contains  commonly  nothing  but  a  little 
t^Z\  I  ''!'  ''  "^"T^^^^  "''^  ^y  "•^'■•^  ^^^'^^  ^^'ch  leaves  the  gold  untmiched  but 
muTt  be'ibsireS!"'^  "''  "^'"^  ^"'  ^^^"^"^^  ^"  ^^^  ^-^^  scale,'several  precautions 

If  the  gold  do  not  contain  fully  two  thirds  of  its  weight  of  silver,  this  metal   beine 
thoroughly  enve  oped  by  the  gold,  is  partially  screened  from^he  action  of  the  acTd      When 
ever,  therefore,  it  is  known  by  a  trial  on  a  small  scale,  that  the  silver  is  much  below  thi, 
proportion,  we  must  bring  the  alloy  of  gold  and  silver  to  that  standard  by  addinl  the  re 
quelle  quantity  of  the  latter  metal.     This  process  is  called  quartation.  " 

1  his  alloy  IS  then  granulated  or  laminated ;  and  from  twice  to  thrice  its  wei-ht  of  sul- 
phuric  or  nm.c  ac.d  is  to  be  boiled  upon  it;  and  when  it  is  judged  that  the  solution  has 
been  pushed  as  far  as  possible  by  this  first  acid,  it  is  decanted,  and  new  acid  ifpoured  on 
Lastly,  after  having  washed  the  gold,  some  sulphuric  acid  is  to  be  boiled  over  it  which 

snl'^r  "f,^  '""''  ?'  '?''^  ihousandth  part  of  silver,  which  nitric  acid  alone  could  iot  diV 
solve.     Thus  perfectly  pure  gold  is  obtained. 

The  silver  held  in  solution  by  the  sulphuric  or  nitric  acid  is  precipitated  in  the  metallic 
state  by  copper,  or  in  the  state  of  chloride  by  sea-salt.     See  Parting  meiaiiic 

Not  only  has  the  ratio  between  the  value  of  gold  and  silver  varied  much  in  different 
ages  of  the  world;  but  the  ratio  between  these  metals  and  the  commodities  they  repre! 
sent  has  undergone  variations,  owing  to  the  circumstances  in  which  their  mines  have 
been  successively  placed;  since  they  have  always  ponred  a  greater  quantitvof  the  metals 
into  the  market  than  has  been  absorbed  by  use.  This  quantity  has  greLlv  inc?^ased 
since  the  discovery  of  America,  a  period  of  little  more  than  300  years!  The  mines  of 
that  continent,  rich,  numerous,  and  easily  worked,  by  augmenting  the  mass  of  gold  and 
silver,  necessarily  lessened  the  value  of  these  metals  compared  with  that  of  the  oLcts 
of  commerce  represented  by  them,  so  that  everything  else  being  equal,  there  is  now 
required  for  purchasing  the  same  quantity  of  commodities,  much"  more  gold  or  silveT 
than  was  necessary  m  the  reign  of  Henry  VII.,  before  the  discovery  of  America  This 
productiveness  of  the  American  mines  has  had  an  influence  on  those  of  .he  ancient  con- 
tinent;  many  of  whose  silver  and  goldmines  have  been  abandoned,  not  becTuseX 
veins  or  auriferous  sands  are  less  rich  than  they  were,  but  because  their  product  no 
longer  represents  the  value  of  human  labor,  and  of  the  goods  to  be  furnished  in  eturn 
for  their  exploitation.  *-"cu  lu  icium 

In  the  3d  vol  of  the  Mining  Journal,  p.  331,  we  have  the  following  statement  as  to 
r  .%n-."r  ""^t"  T"?r  '"'/^'oTo"  '"  ^^  y'^''^  ^'^"^  I'^O  to  1830,  Mexico  produced 
AllilAf  7''m  '^  ^^'^T.'  '"^  ^f '^J»>032/.  of  silver.  Chili,  2,768,488/.  of  goTd  and 
1,822,924/.  of  Sliver.  Buenos  Avres,  4,024,895/  of  eold  anrt  97  iso  ^tq;  "r  i 
Russia  3,703,743/.  of  gold,  and  1,502,98U.  of 's.rver!'  xfuC^SSo'^lnS'trHit "; 
47  millions  per  annum.  o  tumj,,  «• 

The  following  table  shows  what  proportion  the  product  of  the  mines  of  America  bears 
to  that  of  the  mines  of  the  ancient  continent. 


GOLD. 


94T 


Tabu  of  the  Quantities  of  Gold  which  may  be  considered  as  having  been  brought  into 
the  European  Market,  every  Year  on  an  Average,  from  1790  to  1802. 


Continent. 

Gold. 

Ancient  Continent. 

Ibe.  Armr. 

Asia:       -        .        -        -        . 

.        . 

Siberia        .... 

.        . 

3740 

Africa      -        .        -        -        . 

.        . 

3300 

Europe :  - 

^        ^ 

Hungary     .        -        - 

s           • 

1430 

Salzbourg    .... 

. 

165 

Austrian  States    -        -        - 

.    "^ 

Hartz  and  Hessia 

. 

Saxony         .... 

. 

Norway               ... 

. 

p 

165 

Sweden                ... 

.           . 

France                  ... 

.           . 

Spain,  &c.            ... 
Total  of  the  Ancient  Continent 
New  Continent. 

'J 

8800 

North  America  .... 

. 

2860 

South  America  -        .        .        . 

Spanish  dominions    - 

. 

22,000 

Brazil      -        -        -        - 
Total  of  the  New  Continent      - 

• 

15,400 

•               • 

40,260 

The  mines  of  America  have  sent  into  Europe  three  and  a  half  times  more  gold,  nmi 
twelve  times  more  silver,  than  those  of  the  ancient  continent.  The  total  quantity  of 
silver  was  to  that  of  gold  in  the  ratio  of  55  to  1 ;  a  very  different  ratio  from  that  whiek 
holds  really  in  the  value  of  these  two  metals,  which  is  in  Europe  as  1  to  15.  Thm 
difference  depends  upon  several  causes,  which  cannot  be  investigated  here  at  length; 
but  it  may  be  stated  that  gold,  by  its  rarity  and  price,  being  much  less  employed  in  the 
arts  than  silver,  the  demand  for  it  is  also  much  less ;  and  this  cause  is  sufficient  t* 
lower  its  price  much  beneath  what  it  would  have  been,  if  it  had  followed  the  ratio  of  its 
quantity  compared  to  that  of  silver.  Thus  also  bismuth,  tin,  &c.,  though  much  rarer 
than  silver,  are,  nevertheless,  very  inferior  in  price  to  it.  Before  the  discovery  of 
America,  the  value  of  gold  was  not  so  distant  from  that  of  silver,  because  since  that  en 
silver  has  been  distributed  in  Europe  in  a  far  greater  proportion  than  gold.  In  Asia 
the  proportion  is  now  actually  only  1  to  1 1  or  12 ;  the  product  of  the  gold  mines  in  that 
quarter,  being  not  so  much  below  that  of  the  silver  mines  as  in  the  rest  of  the 
world. 

The  total  annual  production  of  Gold  at  present  has  been  estimated  as  follows. 


From  the  ancient  Spanish  colonies  of  America  - 
Brazil        _         -         -         . 
Europe  and  Asiatic  Russia 
The  Indian  Archipelago 
Africa       .... 


10,400  kilogramme! 
600 

6,200 

4,700 
14,000? 


35,900=36  tons  nearlf 
without  taking  into  account  the  quantity  of  gold  now  extracted  from  silver. 

Gold  has  less  aflUnity  for  oxygen  than  any  other  metal.  When  alone,  it  cannot  be 
oxydized  by  any  degree  of  heat  with  contact  of  air,  although  in  combination  with  other 
oxydized  bodies,  it  may  pass  into  the  state  of  an  oxyde,  and  be  even  vitrified.  The  pnr- 
ple  smoke  into  which  gold  leaf  is  converted  by  an  electric  discharge  is  not  an  oxyde, 
for  it  is  equally  formed  when  the  discharge  is  made  through  it  in  hydrogen  gas.  There 
are  two  oxydes  of  gold ;  the  first  or  protoxyde  is  a  green  powder,  which  may  be  ob- 
tained by  pouring,  in  the  cold,  a  solution  of  potash  into  a  solution  of  the  metallic 
chloride.      It  is  not  durable,  but  soon  changes  in  the  menstruum  into  metallic  goM, 


948 


GOLD. 


'1 


•nd  peroxyde.  Its  constituents  are  96- 13  metal,  and  3-87  oxygen.  The  peroxyde  is  best 
prepared  by  adding  magnesia  to  a  solution  of  the  metallic  chloride;  washing  the  precipi- 
tate with  water  till  this  no  longer  takes  a  yellow  tint  from  muriatic  acid;  then  digesting 
strong  nitric  acid  upon  the  residuum,  which  removes  the  magnesia,  and  leaves  the  per- 
oxyde  in  the  form  of  a  black  or  dark  brown  powder,  which  seems  to  partake  more  of  the 
properties  of  a  metallic  acid  than  a  base.  It  contains  10-77  per  cent,  of  oxygen.  For 
the  curious  combination  of  gold  and  tin,  called  the  Purple  Pkecipitate  of  Cassius,  see 
this  article,  and  Pigments  Vitbifiable. 

Gold  beating. — This  is  the  art  of  reducing  gold  to  extremely  thin  leaves,  by  beating 
with  a  hammer.  The  processes  employed  for  this  purpose  may  be  applied  to  other 
metals,  as  silver,  platinum,  and  copper.  Under  tin,  zinc,  &c.,  we  shall  mention  such 
modifications  of  the  processes  as  these  metals  require  to  reduce  them  o  thin  leaves.  The 
Romans  used  to  gild  the  ceilings  and  walls  of  their  apartments ;  and  Pliny  tells  us,  that 
from  an  ounce  of  gold  forming  a  plate  of  4  fingers  square,  about  600  leaves  of  the  same 
area  were  hammered.  At  the  present  day,  a  piece  of  gold  is  extended  so  as  to  cover  a 
space  651,590  times  greater  than  its  primary  surface  when  cast. 

The  gold  employed  in  this  art  ought  to  be  of  the  finest  standard.  Alloy  hardens  gold, 
and  renders  it  less  malleable ;  so  that  the  fraudulent  tradesman  who  should  attempt  to  de- 
base the  gold,  would  expose  himself  to  much  greater  loss  in  the  operations,  than  he  could 
derive  of  profit  from  the  alloy. 

Four  principal  operations  constitute  the  art  of  gold  beating.  1.  The  casting  of  the 
gold  ingots.     2.  The  hammering.     3.  The  lamination  ;  and  4,  the  beating. 

1.  The  gold  is  melted  in  a  crucible  along  with  a  iittle  borax.  When  it  has  become 
-iquid  enough,  it  is  {wtired  out  into  the  ingot-moulds  previously  heated,  and  greased  on 
the  inside.  The  ingot  is  taken  out  and  annealed  in  hot  ashes,  which  both  soften  it  and 
free  it  from  grease.  The  moulds  are  made  of  cast  iron,  with  a  somewhat  concave  in- 
ternal surface,  to  compensate  for  the  greater  contraction  of  the  central  parts  of  the  metal 
in  cooling  than  the  edges.  The  ingots  weigh  about  2  ounces  each,  and  are  J  of  an  inch 
broad. 

2.  The  forging. — When  the  ingot  is  cold,  the  French  gold-beaters  hammer  it  out  on 
a  mass  of  steel  4  inches  long  and  3  broad.  The  hammer  for  this  purpose  is  called  the 
forging  hammer.  It  weighs  about  3  pounds,  with  a  head  at  one  end  and  a  wedge  at  the 
other,  the  head  presenting  a  square  face  of  1^  inches.  Its  handle  is  6  inches  long.  The 
workman  reduces  the  ingot  to  the  thickness  of  J  of  an  inch  at  most ;  and  during  this  op- 
eration he  anneals  it  whenever  its  substance  becomes  hard  and  apt  to  crack.  The  English 
gold-beaters  omit  this  process  of  hammering. 

3.  The  lamination. — The  rollers  employed  for  this  purpose  should  be  of  a  most  per- 
fectly cylindrical  figure,  a  polished  surface,  and  so  powerful  as  not  to  bend  or  yield  in  the 
operation.  The  ultimate  excellence  of  the  gold  leaf  depends  very  much  on  the  precision 
with  which  the  riband  is  extended  in  the  rolling  press.  The  laminating  machine  repre- 
sented under  the  article  Mint,  is  an  excellent  pattern  for  this  purpose.  The  gold-beater 
desires  to  have  a  riband  of  such  thinness  that  a  square  inch  of  it  will  weigh  65  grains. 
Frequent  annealings  are  requisite  during  the  lamination. 

4.  Beating. — The  riband  of  gold  being  thus  prepared  uniform,  the  gold-beater  cuts  it 
with  shears  into  small  squares  of  an  inch  each,  having  previously  divided  it  with  com- 
passes, so  that  the  pieces  may  be  of  as  equal  weight  as  possible.  These  squares  are  piled 
over  each  other  in  parcels  of  150,  with  a  piece  of  fine  calf-skin  vellum  interposed  between 
each,  and  about  20  extra  vellums  at  the  top  and  bottom.  These  vellum  leaves  are  about 
4  inches  square,  on  whose  centre  lie  the  gold  laminae  of  an  inch  square.  This  packet  is 
kept  together  by  being  thrust  into  a  case  of  strong  parchment  open  at  the  ends,  so  as  to 
form  a  belt  or  band,  whose  open  sides  are  covered  in  by  a  second  case  drawn  over  the 
packet  at  right  angles  to  the  first.  Thus  the  packet  becomes  sufiiciently  compact  to 
bear  beating  with  a  hammer  of  15  or  16  pounds  weight,  having  a  circular  face  nearly  4 
inches  diameter,  and  somewhat  convex,  whereby  it  strikes  the  centre  of  the  packet  most 
forcibly,  and  thus  squeezes  out  the  plates  laterally. 

The  beating  is  performed  on  a  very  strong  bench  or  stool  framed  to  receive  a  heavy 
block  of  marble,  about  9  inches  square  on  the  surface,  enclosed  upon  every  side  by  W(K)d- 
work,  except  the  front  where  a  leather  apron  is  attached,  which  the  workman  lays  be- 
fore him  to  preserve  any  fragments  of  gold  that  may  fall  out  of  the  packet.  The  hammer 
is  short-handled,  and  is  managed  by  the  workman  with  one  hand  ;  who  strikes  fairly  on 
the  middle  of  the  packet,  frequently  turning  it  over  to  beat  both  sides  alike  ;  a  feat  dex- 
terously done  in  the  interval  of  two  strokes,  so  as  not  to  lose  a  blow.  The  packet  is  oc- 
casionally bent  or  rolled  between  the  hands,  to  loosen  the  leaves  and  secure  the  ready 
extension  of  the  gold  ;  or  it  is  taken  to  pieces  to  examine  the  gold,  and  to  shift  the  cen- 
tral leaves  to  the  outside,  and  vice  versa,  that  every  thing  may  be  equalized.  Whenever 
the  gold  plates  have  extended,  under  this  treatment,  to  nearly  the  size  of  the  vellum, 
Ibey  are  removed  from  the  packet,  and  cut  into  four  equal  squares  by  a  knife.     Thev 


GOLD. 


949 


I 


are  thus  reduced  to  nearly  the  same  size  as  at  first,  and  are  again  made  up  into  packets 
and  enclosed  as  before,  with  this  difljerence,  that  skins  prepared  from  ox-gut  ure  nov 
interposed  between  each  gold  leaf  instead  of  vellum.  The  second  course  of  beating  is 
performed  with  a  smaller  hammer,  about  10  pounds  in  weight,  and  is  continued  till  the 
leaves  are  extended  to  the  size  of  the  skins.  During  this  period  the  packet  must  be  often 
folded,  to  render  the  gold  as  loose  as  possible  between  the  membranes ;  otherwise  tlje 
leaves  are  easily  chafed  and  broken.  They  are  once  more  spread  on  a  cushion,  and  sub- 
divided into  four  square  pieces  by  means  of  two  pieces  of  cane  cut  to  very  sharp  edges, 
and  fixed  down  transversely  on  a  board.  This  rectangular  cross  being  applied  on  each 
leaf,  with  slight  pressure,  divides  it  into  four  equal  portions.  These  are  next  made  up  into 
a  third  packet  of  convenient  thickness,  and  finally  hammered  out  to  the  area  of  fine  gold 
leaf,  whose  averase  size  is  from  3  to  3^  inches  square.  The  leaves  will  now  have  ob- 
tained an  area  192  times  greater  than  the  plates  before  the  hammering  begun.  As  these 
were  originally  an  inch  square,  and  75  of  them  weighed  an  ounce  (=  6^  X  75  =  487|), 
the  surface  of  the  finished  leaves  will  be  192  X  75  =  14,400  square  inches,  or  100  square 
feet  per  ounce  troy.  This  is  by  no  means  the  ultimate  degree  of  attenuation,  for  an 
ounce  may  be  hammered  so  as  to  cover  160  square  feel ;  but  the  waste  incident  in  this 
case,  fiom  the  number  of  broken  leaves,  and  the  increase  and  nicety  of  the  labor,  make 
this  an  unprofitable  refinement;  while  the  gilder  finds  such  thin  leaves  to  make  less 
durable  and  satisfactory  work. 

The  finished  leaves  of  gold  are  put  up  in  small  books  made  of  single  leaves  of  soft 
paper,  rubbed  over  with  red  chalk  to  prevent  adhesion  between  them.  Before  putting 
the  leaves  in  these  books,  however,  they  ure  lifted  one  by  one  with  a  delicate  yair  of  pin- 
cers out  of  the  finishing  packet,  and  spread  out  on  a  leather  cushion  by  blowing  them  flat 
down.  They  are  then  cut  to  one  size,  by  a  sharp-edge  square  moulding  of  cane,  glued 
on  a  flat  board.  When  this  square-framed  edge  is  pressed  upon  the  gold,  it  cuts  it  to  the 
desired  size  and  shape.    Each  book  commonly  contains  25  gold  leaves.  % 

I  shall  now  describe  some  peculiarities  of  the  French  practice  of  gold  beating.  The 
workman  cuts  the  laminated  ribands  of  an  inch  broad  into  portions  an  inch  and  a  half 
long.  These  are  called  quartiers.  He  takes  24  of  them,  which  he  places  exactly  over 
each  other,  so  as  to  form  a  thickness  of  about  an  inch,  the  riband  being  |  of  a  line,  or 
Jj  of  an  inch  thick ;  and  he  beats  them  together  on  the  steel  slab  with  the  round  face 
(panne)  of  the  hammer,  so  as  to  stretch  them  truly  out  into  the  square  form.  He  begins 
by  extending  the  substance  towards  the  edges,  thereafter  advancing  towards  the  middle ; 
he  then  does  as  much  on  the  other  side,  and  finally  hammers  the  centre.  By  repeating 
this  mode  of  beating  as  often  as  necessary,  he  reduces  at  once  all  the  quartiers  (squares) 
of  the  same  packet,  till  none  of  them  is  thicker  than  a  leaf  of  gray  paper,  and  of  the 
size  of  a  square  of  2  inches  each  side. 

When  the  quartiers  are  brought  to  this  state,  the  workman  takes  56  of  them,  which 
he  piles  over  each  other,  and  with  which  he  forms  the  first  packet  (caucher)  in  the  man- 
ner already  described  ;  only  two  leaves  of  vellum  are  interposed  between  each  gold  leaf. 
The  empty  leaves  of  vellum  at  the  top  and  bottom  of  the  packet  are  called  emplures. 
They  are  4  inches  square,  as  well  as  the  parchment  pieces. 

The  packet  thus  prepared  forms  a  rectangular  parallelopiped ;  it  is  enclosed  in  two 
sheaths,  composed  each  of  several  leaves  of  parchment  applied  to  each,  and  glued  at  the 
two  sides,  forming  a  bag  open  at  either  end. 

The  block  of  black  marble  is  a  foot  square  at  top,  and  18  inches  deep,  and  is  framed 
as  above  described.  The  hammer  used  for  beating  the  first  packet  is  called  the  flat, 
or  the  enlarging  hammer;  its  head  is  round,  about  5  inches  in  diameter,  and  very  slightly 
convex.  It  is  6  inches  high,  and  tapers  gradually  from  its  head  to  the  other  extremity, 
which  gives  it  the  form  of  a  hexagonal  truncated  pyramid.  It  weighs  14  or  15 
pounds. 

The  French  gold-beaters  employ,  besides  this  hammer,  three  others  of  the  same  form ; 
namely,  1.  The  commencing  hammer^  which  weighs  6  or  7  pounds,  has  a  head  4  inches 
in  diameter,  and  is  more  convex  than  the  former.  2.  The  spreading  hammer  (marleau 
d  chasser) ;  its  head  is  two  inches  diameter,  more  convex  than  the  last,  and  weighs  only 
4  or  5  pounds.  3.  The  finishing  hammer ;  it  weighs  12  or  13  pounds,  has  a  head  fopr 
inches  diameter,  and  is  the  most  convex  of  all. 

The  beatinc  processes  do  not  differ  essentially  from  the  English  described  above.  The 
vellum  is  rubbed  over  with  fine  calcined  Paris  plaster,  with  a  hare's  foot.  The  skin  of 
the  gold-beater  is  a  pellicle  separated  from  the  outer  surface  of  ox-gut ;  but  before 
being  employed  for  this  purpose,  it  must  undergo  two  preparations.  1.  It  is  sweated,  in 
order  to  expel  any  grease  it  may  contain.  With  this  view,  each  piece  of  membrane  is 
placed  between  two  leaves  of  white  paper ;  several  of  these  pairs  are  piled  over  each 
other,  and  struck  strongly  with  a  hammer,  which  drives  the  grease  from  the  gut  into  the 
paper. 

2.  A  body  is  given  to  the  pieces  of  gut ;  that  is,  they  are  moistened  with  an  infasioD 


950 


GOLD. 


of  cinnamon,  nutmeg,  and  other  warm  and  aromatic  ingredients,  in  order  to  preserve 
them ;  an  operation  repeated  aAer  they  have  been  dried  in  the  air.  When  the  leaves  of 
skin  ai-edry,  they  are  put  in  a  press,  and  are  now  ready  for  use.  After  the  parchment^ 
vellum,  and  gut  membrane  have  been  a  good  deal  hammered,  they  become  unfit  for  work, 
till  they  are  restored  to  proper  flexibility,  by  being  placed  leaf  by  leaf  between  leaves 
of  wliite  paper,  moistened  sometimes  with  vinegar,  at  others  with  white  wine.  They  are 
left  in  this  predicament  for  3  or  4  hours,  under  compression  of  a  plank  loaded  with  weights. 
When  they  have  imbibed  the  proper  humidity,  they  are  put  between  leaves  of  parchment 
12  inches  square,  and  beat  in  that  situation  for  a  whole  day.  They  are  then  rubbed 
over  with  fine  calcined  gypsum,  as  the  vellum  was  originally.  The  gut-skin  is  apt  to 
contract  damp  in  standing,  and  is  therefore  dried  before  being  used. 


The  average  thickness  of  common  gold  leaf  is 


of  an  inch. 


282000 

The  art  of  Gilding, — This  art  consists  in  covering  bodies  with  a  thin  coat  of  gold ; 
which  may  be  done  either  by  mechanical  or  chemical  means.  The  mechanical  mode  is 
the  application  of  gold  leaf  or  gold  powder  to  various  surfaces,  and  their  fixation  by  va- 
rious means.  Thus  gold  may  be  applied  to  wood,  plaster,  pasteboard,  leather ;  and  to 
metals,  such  as  silver,  copper,  iron,  tin,  and  bronze;  so  that  gilding,  geneially  speaking, 
includes  several  arts,  exercised  by  very  dififerent  classes  of  tradesmen. 

I.  Mechanical  Gilding. — Oil  gilding  is  the  first  method  under  this  head,  as  oil  is  the 
fluid  most  generally  used  in  the  operation  of  this  mechanical  art.  The  following  process 
has  been  much  extolled  at  Paris. 

1.  A  coat  of  impression  is  to  be  given  first  of  all,  namely,  a  coat  of  white  lead  paint, 
made  with  drying  linseed  oil,  containing  very  little  oil  of  turpentine. 

2.  Calcined  ceruse  is  to  be  ground  very  well  with  unboiled  linseed  oil,  and  tempered 
with  essence  of  turpentine,  in  proportion  as  it  is  laid  on.  Three  or  four  coats  of  this 
hard  tint  are  to  be  applied  evenly  and  dryly  on  the  ornaments  and  the  parts  wlych  are  to 
^  most  carefully  gilded. 

3.  The  Gold  color  is  then  to  be  smoothly  applied.  This  is  merely  the  dregs  of  the 
colors,  ground  and  tempered  with  oil,  which  remain  in  the  little  dish  in  which  painters 
3lean  their  brushes.  This  substance  is  extremely  rich  and  gluey ;  after  being  ground 
ap,  and  passed  through  fine  linen  cloth,  it  forms  the  ground  for  gol(^  leaf. 

4.  When  the  gold  color  is  dry  enough  to  catch  hold  of  the  Icni"  gold,  this  is  spread  on 
the  cushion,  cut  into  pieces,  and  carefully  applied  with  the  palette  knife,  pressed  down 
with  cotton,  and  in  the  small  ornaments  with  a  fine  brush. 

5.  If  the  gildings  be  for  outside  exposure,  as  balconies,  gratings,  statues,  &c.,  they 
must  not  be  varnished,  as  simple  oil  gilding  stands  belter ;  for  when  it  is  varnished,  a 
bright  sun-beam,  acting  after  heavy  rain,  gives  the  gilding  a  jagged  appearance.  When 
the  objects  are  inside  ones,  a  coat  of  spirit  varnish  may  be  passed  over  the  gold  leaf,  then 
a  glow  from  the  gilder's  chafing  dish  may  be  given,  and  finally  a  coat  of  oil  varnish.  The 
workman  who  causes  the  chafing  dish  to  glide  in  front  of  the  varnished  surface,  must 
avoid  stopping  for  an  instant  opposite  any  point,  otherwise  he  would  cause  the  varnish 
to  boil  and  blister.  This  heat  brings  out  the  whole  transparency  of  the  varnish  and 
lustre  of  the  gold. 

Oil  Gilding  is  employed,  with  varnish  polish,  upon  equipages,  mirror- frames,  and  other 
furniture.    The  following  method  is  employed  by  eminent  gilders  at  Paris. 

1.  White  lead,  with  half  its  weight  of  yellow  ochre,  and  a  little  litharge,  are  sepa- 
rately ground  very  fine ;  and  the  whole  is  then  tempered  with  linseed  oil,  thinned  with 
essence  of  turpentine,  and  applied  in  an  evenly  coat,  called  impression. 

2.  When  this  coat  is  quite  dry,  several  coats  of  the  hard  tint  are  given,  even  so  many 
as  10  or  12,  should  the  surface  require  it,  for  smoothing  and  filling  up  the  pores.  These 
coats  are  given  daily,  leaving  them  to  dry  in  the  interval  in  a  warm  sunny  exposure. 

3.  When  the  work  is  perfectly  dry,  it  is  first  softened  down  with  pumice  slone  and  water, 
afterwards  with  worsted  cloth  and  very  finely  powdered  pumice,  till  the  hard  tint  give 
no  reflection,  and  be  smooth  as  glass. 

4.  With  a  camel's  hair  brush,  there  must  be  given  lightly  and  with  a  gentle  heat,  from 
4  to  5  coats  at  least,  and  even  sometimes  double  that  number,  of  fine  lac  varnish. 

5.  When  these  are  dry,  the  grounds  of  the  panels  and  the  sculptures  must  be  first 
polished"  with  shave-grass  (de  laprlle)  ;  and  next  with  putty  of  tin  and  tripoli,  tempered 
with  water,  applied  with  woollen  cloth  ;  by  which  the  varnish  is  polished  till  it  shines 
like  a  mirror. 

6.  The  work  thus  polished  is  carried  into  a  hot  place,  free  from  dust,  where  it  receives 
very  lightly  and  smoothly  a  thin  coat  of  gold  color,  mu?h  softened  down.  This  coat  is 
passed  over  it  with  a  clean  soft  brush,  and  the  thinner  it  is  the  better. 

7.  Whenever  the  gold  color  is  dry  enough  to  take  the  gold,  which  is  known  by  laying 
the  back  of  the  hand  on  a  corner  of  the  frame  work,  the  gilding  is  begun  and  finished 
as  usual. 

8.  The  gold  is  smoothed  oflf  with  a  very  soft  bmsh,  one  of  camel's  hair,  for  example, 
of  three  fingers'  breadth ;  after  which  it  is  left  to  dry  for  several  days. 


GOLD. 


951 


I' 


I 


9.  It  is  then  varnished  with  a  spirit  of  wine  varnish ;  which  »s  treated  with  the  chafing 
dish  as  above  described. 

10.  When  this  varnish  is  dry,  two  or  three  coats  of  cepal  or  oil  varnish  are  applied,  at 
intervals  of  two  days. 

11.  Finally,  the  panels  are  polished  with  a  worsted  cloth,  imbued  with  tripoli  and 
water,  and  lustre  is  given  by  friction  with  the  palm  of  the  hand,  previously  softened  with 
a  little  olive  oil,  taking  care  not  to  rub  off"  the  gold. 

In  this  courttry,  burnished  gilding  is  practised  by  first  giving  a  ground  of  size  whiting, 
in  several  successive  coats ;  next  applying  gilding  size ;  and  then  the  gold  leaf,  which  is 
burnished  down  with  agate,  or  a  dog's  tooth. 

Gilding  in  distemper  of  the  French,  is  the  same  as  our  burnished  gilding.  Their  pro- 
cess seems  to  be  very  elaborate,  and  the  best  consists  of  17  operations ;  each  of  them 
said  to  be  essential. 

1.  Encollage,  or  the  glue  coat.  To  a  decoction  of  wormwood  and  garlic  in  water, 
strained  through  a  cloth,  a  little  common  salt  and  some  vinegar  are  added.  This  com- 
position, as  being  destructive  of  worms  in  wood,  is  mixed  with  as  much  good  glue ;  and  the 
mixture  is  spread  in  a  hot  state,  with  a  brush  of  boar's  hair.  When  plaster  or  marble  is 
to  be  gilded,  the  salt  must  be  left  out  of  the  above  composition,  as  it  is  apt  to  attract  hu- 
midity in  damp  places,  and  to  come  out  as  a  white  powder  on  the  gilding.  But  the  salt 
is  indispensable  for  wood.     The  first  glue  coating  is  made  thinner  than  the  second. 

2.  White  preparation.  This  consists  in  covering  the  above  surface  with  8,  10,  or  12 
coats  of  Spanish  white,  mixed  up  with  strong  size,  each  well  worked  on  with  the  brush, 
and  in  some  measure  incorporated  with  the  preceding  coat,  to  prevent  their  peeling  oflf 
in  scales. 

3.  Stopping  up  the  pores,  with  thick  whiting  and  glue,  and  smoothing  the  surface  with 
dog-skin. 

4.  Polishing  the  surface  with  pumice-stone  and  very  cold  water. 

5.  Reparation;  in  which  a  skilful  artist  retouches  the  whole. 

6.  Cleansing ;  with  a  damp  linen  rag,  and  then  a  soft  sponge. 

7.  Preler.  This  is  rubbing  with  horse's  tail  (shave-grass)  the  parts  to  be  yellowed,  in 
order  to  make  them  softer. 

8.  Yellowing.  With  this  view  yellow  ochre  is  carefully  ground  in  water,  and  mixed 
with  transparent  colorless  size.  The  thinner  part  of  this  mixture  is  applied  hot  over  the 
white  surface  with  a  fine  brush,  which  gives  it  a  fine  yellow  hue. 

9.  Ungraining  consists  in  rubbing  the  whole  work  with  shave-grass,  to  remove  any 
granular  appearance. 

10.  Coat  of  assiette ;  trencher  coat.  This  is  the  composition  on  which  the  gold  is  to 
be  laid.  It  is  composed  of  Armenian  bole,  1  pound  ;  bloodstone  (hematite),  2  ounces ; 
and  as  much  ealcna ;  each  separately  ground  in  water.  The  whole  are  then  mixed  to- 
gether, and  ground  up  with  about  a  spoonful  of  olive  oil.  The  assiette  well  made  and  ap- 
plied gives  beauty  to  the  gilding.  The  assiette  is  tempered  with  a  white  sheep-skin  glue, 
very  clear  and  well  strained.  This  mixture  is  heated  .nd  applied  in  three  successive 
coats,  with  a  very  fine  long-haired  brush. 

11.  Rubbing,  with  a  piece  of  dry,  clean  linen  cloth;  except  the  parts  to  be  burnished, 
vvfaich  are  to  receive  other  two  coats  of  assiette  tempered  with  glue. 

12.  Gilding.  The  surface,  being  damped  with  cold  water  (iced  in  summer),  has  then 
the  gold  leaf  applied  to  it.  The  hollow  grounds  must  always  be  gilded  before  the  pro- 
minent parts.  Water  is  dexterously  applied  by  a  soft  brush,  immediately  behind  the 
gold  leaf,  before  laying  it  down,  which  makes  it  lie  smoother.  Any  excess  of  water  is 
then  removed  with  a  dry  brush. 

13.  Burnishing  with  bloodstone. 

14.  Deadening.  This  consists  in  passing  a  thin  coat  of  glue,  slightly  warmed,  over  the 
parts  that  are  not  to  be  burnished. 

15.  Mending ;  that  is,  moistening  any  broken  points  with  a  brush,  and  applying  bits 
of  gold  leaf  to  them. 

16.  The  vermeil  coat.  Vermeil  is  a  liquid  which  gives  lustre  and  fire  to  the  gold  ;  and 
makes  it  resemble  or  moulu.  It  is  composed  as  follows  :  2  ounces  of  annotto,  1  ounce 
of  gamboge,  1  ounce  of  vermilion,  half  an  ounce  of  dragon's  blood,  2  ounces  of  salt  of 
tartar,  and  18  grains  of  saflTron,  are  boiled  in  a  litre  (2  pints  English)  of  water,  over  a 
slow  fire,  till  the  liquid  be  reduced  to  a  fourth.  The  whole  is  then  passed  through  a 
silk  or  muslin  sieve.  A  little  of  this  is  made  to  glide  lightly  over  the  gold,  with  a  very 
soft  brush. 

17.  Repassage  is  passing  over  the  dead  surfaces  a  second  coat  of  deadening  glue, 
which  must  be  hotter  than  the  first.     This  finishes  the  work,  and  gives  it  strength. 

Leaf  gilding,  on  paper  or  vellum,  is  done  by  giving  them  a  coat  of  gum  water  or  fine 
size,  applying  the  gokl  leaf  ere  the  surfaces  be  hard  dry,  and  burnishing  with  agate. 


962 


GOLD. 


Gold  Jetteringf  on  bound  books,  is  given  without  size,  by  laying  the  gold  leaf  on  the 
leather,  and  imprinting  it  with  hot  brass  types. 

The  edges  of  /he  leaves  of  books  are  gilded  while  they  are  in  the  press,  where  they  have 
been  cut  smooth,  by  applying  a  solution  of  isinglass  in  spirits,  and  laying  on  the  gold 
'when  the  edges  are  in  a  proper  state  of  dryness.  The  French  workmen  employ  a  ground 
of  Arnenian  bole,  mixed  with  powdered  sugar-candy,  by  means  of  white  of  egg.  This 
ground  is  laid  very  thin  upon  the  edges,  after  fine  size  or  gum  water  has  been  applied  ; 
and  when  the  ground  is  dry  it  is  rubbed  smooth  with  a  wet  rag,  which  moistens  it  suffi- 
ciently to  take  the  gold. 

Japanner's  gilding  is  done  by  sprinkling  or  daubing  with  wash  leather,  some  gold  pow- 
jer,  over  an  oil  sized  surface,  mixed  with  oil  of  turpentine.  This  gi\es  the  appearance 
of  frosted  gold.  The  gold  powder  may  be  obtained,  either  by  precipitating  gold  from  its 
solution  in  aqua  regia  by  a  solution  of  pure  sulphate  of  iron,  or  by  evaporating  away  the 
mercury  from  some  gold  amalgam. 

yi.  Chemical  gildingj  or  the  application  of  gold  by  chemical  affinity  to  metallic  sur 
faces. 

A  compound  of  copper  with  one  seventh  of  brass  is  the  best  metal  for  gilding  on  ;  cop- 
per by  itself  being  too  soft  and  dark  colored.  Ordinary  bras?,  however,  answers  very 
well.  We  shall  describe  the  process  of  wash  gilding,  with  M.  D'Arcel*s  late  improve- 
ments, now  generally  adopted  in  Paris. 

Wash  gilding  consists  in  applying  evenly  an  amalgam  of  gold  to  the  surface  of  a  cop- 
per alloy,  and  dissipating  the  mercury  with  heat,  so  as  to  leave  the  gold  film  fixed.  The 
surface  is  afterwards  burnished  or  deadened  at  pleasure.  The  gold  ought  to  be  quite 
pure,  and  laminated  to  facilitate  its  combination  with  the  mercury ;  which  should  also 
be  pure. 

Preparation  of  the  amalgam.  After  weighing  the  fine  gold,  the  workman  puts  it  in  a 
crucible,  and  as  soon  as  this  becomes  faintly  red,  he  pours  in  the  requisite  quantity 
of  mercury;  which  is  about  8  to  1  of  gold.  He  stirs  up  the  mixture  with  an  iron  rod, 
bent  hookwise  at  the  end,  leaving  the  crucible  on  the  fire  till  he  perceives  that  all  ihe 
gold  is  dissolved.  He  then  pours  the  amalgam  into  a  small  earthen  dish  containing  water, 
washes  it  with  care,  and  squeezes  out  of  it  with  his  fingers  all  the  running  mercury  that 
he  can.  The  amalgam  that  now  remains  on  the  sloping  sides  of  the  vessel  is  so  pasty  as 
to  preserve  the  impression  of  the  fingers.  When  this  is  squeezed  in  a  shamoy  leather 
bag,  it  gives  up  much  mercury;  and  remains  an  amalgam,  consisting  of  about  33  of  mer- 
cury, and  57  of  gold,  in  100  parts.  The  mercury  which  passes  through  the  bag,  under 
the  pressure  of  the  fingers,  holds  a  good  deal  of  gold  in  solution ;  and  is  employed  in  ma- 
king fresh  amalgam. 

Preparation  of  the  mercurial  solution.  The  amalgam  of  gold  is  applied  to  brass,  through 
the  intervention  of  pure  nitric  acid,  holding  in  solution  a  little  mercury. 

100  parts  of  mercury,  and  110  parts  by  weight  of  pure  nitric  acid,  specific  gravity  1*33, 
are  to  be  put  into  a  glass  matrass.  On  the  application  of  a  gentle  heat  the  mercury  dis- 
solves with  the  disengagement  of  fumes  of  nitrous  gas,  which  must  be  allowed  to  escape 
into  the  chimney.  This  solution  is  to  be  diluted  with  about  25  times  its  weight  of  pure 
water,  and  bottled  up  for  use. 

1.  .Annealing. — The  workman  anneals  the  piece  of  bronze  after  it  has  come  out  of  the 
hands  of  the  turner  and  engraver.  He  sets  it  among  burning  charcoal,  or  rather  peats, 
which  have  a  more  equal  and  lively  flame ;  covering  it  quite  up,  so  that  it  may  be  oxydized 
as  little  as  possible,  and  taking  care  that  the  thin  parts  of  the  piece  do  not  become  hotter 
than  the  thicker.  This  operation  is  done  in  a  dark  room,  and  when  he  sees  the  piece  of 
a  cherry  red  color,  he  removes  the  fuel  from  about  it,  lifts  it  out  with  long  tongs,  and  sets 
it  to  cool  slowly  in  the  air. 

2.  The  decapage. — ^The  object  of  this  process  is  to  clear  the  surface  from  the  coat  of 
oxyde  which  may  have  formed  upon  it.  The  piece  is  plunged  into  a  bucket  filled  with 
extremely  dilute  sulphuric  acid ;  it  is  left  there  long  enough  to  allow  the  coat  of  oxyde  to 
be  dissolved,  or  at  least  loosened ;  and  it  is  then  rubbed  with  a  hard  brush.  When  the 
piece  becomes  perfectly  bright,  it  is  washed  and  dried.  Its  surface  may  however  be  still 
a  little  variegated  ;  and  the  piece  is  therefore  dipped  in  nitric  acid,  specific  gravity  1*33, 
and  afterwards  rubbed  with  a  long-haired  brush.  The  addition  of  a  litile  common  salt 
to  the  dilute  sulphuric  acid  would  probably  save  the  use  of  nitric  acid,  which  is  so  apt  to 
produce  a  new  coat  of  oxyde.  It  is  finally  made  quite  dry  (after  washing  in  pure  water), 
by  being  rubbed  well  with  tanners'  dry  bark,  saw-dust,  or  bran.  The  surface  should 
now  appear  somewhat  de-polished ;  for  when  it  is  very  smooth,  the  gold  does  not  adhere 
to  well. 

Application  of  ihe  amalgam. — ^Thc  gilder's  scratch-brush  or  pencil,  made  with 
fine  brass  wire,  is  to  be  dipped  into  the  solution  of  nitrate  of  mercury,  and  is 
then  to  be  drawn  over  a  lump  of  gold  amalgam,  laid  on  the  sloping  side  of  an  earthen 
vessel,  after  which  it  is  to  be  applied  to  the  surface  of  the  brass.    This  process  is  to  be 


GOLD. 


953 


repeated,  dipping  the  brush  into  the  solution,  and  drawing  it  over  the  amalgam,  till  the 
whole  surface  to  be  gilded  is  coated  with  its  just  proportion  of  gold.  The  piece  is  then 
washed  in  a  body  of  water,  dried,  and  put  to  the  fire  to  volatilize  the  mercury.  If  one 
coat  of  gilding  be  insufficient,  the  piece  is  washed  over  anew  with  amalgam,  and  the  op- 
eration  recommenced  till  the  work  prove  satisfactory. 

4.  Volatilization,  of  the  mercury. — Whenever  the  piece  is  well  coated  with  amalgam, 
the  gilder  exposes  it  to  glowing  charcoal,  turning  it  about,  and  heating  it  by  degrees 
to  the  proper  point ;  he  then  withdraws  it  from  the  fire,  lifts  it  with  long  pincers,  and, 
seizing  it  in  his  left  hand,  protected  by  a  stufifed  glove,  he  turns  it  over  in  every  direc- 
tion, rubbing  and  striking  it  all  the  while  with  a  long-haired  brush,  in  order  to  equalize 
the  amalgam.  He  now  restores  the  piece  to  the  fire,  and  treats  it  in  the  same  way  till 
the  mercury  be  entirely  volatilized,  which  he  recognises  by  the  hissing  sound  of  a  drop 
of  water  let  fall  on  it.  During  this  time  he  repairs  the  defective  spots,  taking  care  to 
I'olatilize  the  mercury  very  slowly.  The  piece,  when  thoroughly  coaled  with  gold,  is 
washed,  and  scrubbed  well  with  a  brush  in  water  acidulated  with  vinegar. 

If  the  piece  is  to  have  some  parts  burnished,  and  others  dead,  the  parts  to  be  burnished 
are  covered  with  a  mixture  of  Spanish  white,  bruised  sugar-candy,  and  gum  •'•ssolved  in 
water.  This  operation  is  called  in  French  epargner  (protecting).  When  the  gilder  has 
protected  the  burnished  points,  he  dries  the  piece,  and  carries  the  heat  high  enough  to 
expel  the  little  mercury  which  might  still  remain  on  it.  He  then  plunges  it,  while  still 
a  little  hot,  in  water  acidulated  with  sulphuric  acid,  washes  it,  dries  it,  and  gives  it  the 
burnish. 

5.  The  burnish  is  given  by  rubbing  the  piece  with  burnishers  of  hematite  (blood- 
stone). The  workman  dips  his  burnisher  in  water  sharpened  with  vinegar,  and  rubs  the 
piece  always  in  the  same  direction  backwards  and  forwards,  till  it  exhibits  a  fine  polish, 
and  a  complete  metallic  lustre.  He  then  washes  it  in  cold  water,  dries  it  with  fine  linen 
cloth,  and  concludes  the  operation  by  drying  it  slowly  on  a  grating  placed  above  a  chafing 
dish  of  burning  charcoal. 

6.  The  deadening  is  given  as  follows.  The  piece,  covered  with  the  protection  on  those 
parts  that  are  to  be  burnished,  is  attached  with  an  iron  wire  to  the  end  of  an  iron  rod, 
and  is  heated  strongly  so  as  to  give  a  brown  hue  to  the  epargne  by  its  partial  carbon- 
ization. The  gilded  piece  assumes  thus  a  fine  tint  of  gold;  and  is  next  coated  over  with 
a  mixture  of  sea  salt,  nitre,  and  alum,  fused  in  the  water  of  crystallization  of  the  latter 
salt.  The  piece  is  now  restored  to  the  fire,  and  heated  till  the  saline  crust  which  covers 
it  becomes  homogeneous,  nearly  transparent,  and  enters  into  true  fusion.  It  is  then  taken 
from  the  fire  and  suddenly  plunged  into  cold  water,  which  separates  the  saline  crust,  car- 
rying away  even  the  coat  ot  epargne.  The  piece  is  lastly  passed  through  very  weak  nitrle 
acid,  washed  in  a  great  body  of  water,  and  dried  by  exposure  either  to  the  air,  over  a 
drying  stove,  or  with  clean  linen  cloths. 

7.  Of  or-moulu  color. — When  it  is  desired  to  put  a  piece  of  gilded  bronze  into  or- 
moulu  color,  it  must  be  less  scrubbed  with  the  scratch-brush  than  usual,  and  made  to 
come  back  again  by  heating  it  more  strongly  than  if  it  were  to  be  deadened,  and  allowing 
it  then  to  cool  a  little.  The  or-moulu  coloring  is  a  mixture  of  hematite,  alum,  and 
sea  salt.  This  mixture  is  to  be  thinned  with  vinegar,  and  applied  with  a  brush  so  as  to 
cover  the  gilded  brass,  with  reserve  of  the  burnished  parts.  The  piece  is  then  put  on 
glowing  coals,  urged  a  liitle  by  the  bellows,  and  allowed  to  heat  till  the  color  begins 
to  blacken.  The  piece  ought  to  be  so  hot  that  water  sprinkled  on  it  may  cause  a  hissing 
noise.  It  is  then  taken  from  the  fire,  plunged  into  cold  water,  washed,  and  next  rubbed 
with  a  brush  dipped  in  vinegar,  if  the  piece  be  smooth,  but  if  it  be  chased,  weak  nitric 
acid  must  be  used.  In  either  case,  it  must  be  finally  washed  in  a  body  of  pure  water,  and 
dried  over  a  gentle  fire. 

8.  Of  red  gold  color. — To  give  this  hue,  the  piece,  after  being  coated  with  amalgam 
and  heated,  is  in  this  hot  state  to  be  suspended  by  an  iron  wire,  and  tempered  with  the 
composition  known  under  the  name  of  gilder's  wax ;  made  with  yellow  wax,  red  ochre, 
verdigris,  and  alum.  In  this  state  it  is  presented  to  the  flame  of  a  wood  fire,  is  heated 
strongly,  and  the  combustion  of  its  coating  is  favored  by  throwing  some  drops  of  the  wax 
mixture  into  the  burning  fuel.  It  is  now  turned  round  and  round  over  the  fire,  so  that  the 
flame  may  act  equally.  When  all  the  wax  of  the  coloring  is  burned  away,  and  when  the 
flame  is  extinguished,  the  piece  is  to  be  plunged  in  water,  washed,  afid  scrubbed  with  the 
scratch-brush  and  pure  vinegar.  If  the  color  is  not  beautiful,  and  quite  equal  in  shade, 
the  piece  is  coated  with  verdigris  dissolved  in  vinegar,  dried  over  a  gentle  fire,  plunged 
in  water,  and  scrubbed  with  pure  vinegar,  or  even  with  a  little  weak  nitric  acid  if  the 
piece  exhibit  too  dark  a  li  le.  It  is  now  washed,  burnished,  washed  anew,  wiped  with 
linen  cloth,  and  finally  dried  over  a  gentle  fire. 

The  f»llowing  is  the  outline  of  a   complete  gilding  factory,  as  now  fitted   up  at 
Paris. 
Fig.  738.  Front  elevation  and  plan  of  a  complete  gilding  workshop. 


954 


GOLD. 


GRADUATOR. 


955 


p.  Fainace  «^  appelf  or  draught,  serving  at  the  same  time  to  heat  the  deadening  pao 
(p0iUni  au  mat). 

788 


P 


^^^^^ 


■"J^S^^ 


r.  Ashpit  of  this  furnace. 

N.  Chimney  of  this  furnace  constructed  of  bricks,  as  far  as  the  contraction  of  tiie 
great  chimney  s  of  the  forge,  and  which  is  termiDated  by  a  summit  pipe  rising  2  or  3 
yards  above  this  contraction. 

B.  Forge  for  annealing  the  pieces  of  bronze;  for  drying  the  gilded  pieces, &c. 

c.  Chimney  of  communication  between  the  annealing  forge  b,  and  the  space  d  below 
the  forge.  This  chimney  serves  to  carry  the  noxious  fumes  into  the  great  vent  of  the 
factory. 

u.  Bucket  for  the  brightening  operation. 

A.  Forge  for  passing  the  amalgam  over  the  piece. 

E.  Shelf  for  the  brushing  operations. 

E  E.  Coal  cellarets. 

0.  Forge  for  the  deadening  process. 
G.  Furnace  for  the  same. 

M.  An  opening  into  the  furnace  of  appd,  by  which  vapors  may  be  let  off  from  any  ope- 
ration by  taking  out  the  plug  at  m. 

1.  Cask  in  which  the  pieces  of  gilded  brass  are  plunged  for  the  deadening  process. 
The  vapors  rising  thence  are  carried  up  the  general  chimney. 

J  J.  Casement  with  glass  panes,  which  serves  to  contract  the  opening  of  the  hearths, 
without  obstructing  the  view.  The  casement  may  be  rendered  moveable  to  admit  lai^er 
objects. 

H  H.  Curtains  of  coarse  cotton  cloth,  for  closing  at  pleasure,  in  whole  or  part,  one  or 
several  of  the  forges  or  hearths,  and  for  quickening  the  current  of  air  in  the  places  whem 
the  curtains  are  not  drawn 

Q.  Opening  above  the  draught  furnace,  which  serves  for  the  heating  of  the  poejon  a% 
mat  (deadening  pan). 

Gilding  on  polished  iron  and  steel. — If  a  nearly  neutral  solution  of  gold  in  muriatic 
acid  be  mixed  with  sulphuric  ether,  and  agitated,'  the  ether  will  take  up  the  cold,  and 
float  above  the  denser  acid.  When  this  auriferous  ether  is  applied  by  a  hair  pencil  to 
brightly  polished  iron  or  steel,  the  ether  flies  off,  and  the  gold  adheres.  It  must  be  fixed 
by  polishing  with  the  burnisher.  This  gilding  is  not  very  rich  or  durable.  In  fact,  the 
affinity  between  gold  and  iron  is  feeble,  compared  to  that  between  gold  and  copper  or 
•ilrer.  But  polished  iron,  steel,  and  copper,  may  be  gilded  with  heat,  by  gold  leaf. 
They  are  first  heated  till  the  iron  takes  a  bluish  tint,  and  till  the  copper  has  attained  to 
a  like  temperature;  a  first  coat  of  gold  leaf  is  now  applied,  which  is  pressed  gently 


down  with  a  burnisher,  and  then  exposed  to  a  gentle  heat.      Several  leaves  either  single 
or  double  are  thus  applied  in  succession,  and  the  last  is  burnished  down  cold. 

Cold  gilding. — Sixty  grains  of  fine  gold  and  12  of  rose  copper  are  to  be  dissolved  in 
two  ounces  of  aqua  resia.  When  the  solution  is  completed,  it  is  to  be  dropped  on  clean 
linen  rag?,  of  such  bulk  as  to  absorb  all  the  liquid.  They  are  then  dried,  and  burned  in- 
to ashes.     These  ashes  contain  the  gold  in  powder. 

When  a  piece  is  to  be  eilded,  after  subjecting  it  to  the  preliminary  operations  of  soft- 
ening or  annealing  and  brightening,  it  is  rubbed  with  a  moistened  cork,  dipped  in  the 
above  powder,  till  the  surface  seems  to  be  sufficiently  gilded.  Large  works  are  there- 
after burnished  with  pieces  of  hematite,  and  small  ones  with  steel  burnishers,  along  with 
soap  water. 

In  gilding  small  articles,  as  buttons,  with  amalgam,  a  portion  of  this  is  taken  equivalent 
to  the  work  to  be  done,  and  some  nitrate  of  mercury  solution  is  added  to  it  in  a  wooden 
trough  ;  the  whole  articles  are  now  put  in,  and  well  worked  about  with  a  hard  brush,  till 
their  surfaces  are  equably  coated.  They  are  then  washed,  dried,  and  put  altogether  iRto 
an  iron  frying-pan,  and  healed  till  the  mercury  begins  to  fly  off,  when  they  are  turned  out 
into  a  cap,  in  which  they  are  tossed  and  well  stirred  about  with  a  painter's  brush.  The 
operation  must  be  repeated  several  times  for  a  strong  gilding.  The  surfaces  are  hnally 
brightened  by  brushing  them  along  with  small  beer  or  ale  grounds. 

Gold  wire  is  formed  by  drawmg  a  cylindrical  rod  of  the  metal,  as  pure  as  may  be, 
through  a  series  of  holes  punched  in  an  iron  plate,  diminishing  progressively  in  size.  The 
gold,  as  it  is  drawn  through,  becomes  hardened  by  the  operation,  and  requires  frequent 
annealing. 

Gold  thread,  or  spun  gold,  is  a  flatted  silver-gilt  wire,  wrapped  or  laid  over  a  thread  of 
yellow  silk,  by  twisting  with  a  wheel  and  iron  bobbins.  By  the  aid  of  a  mechanism  like 
the  Braiding  Machine,  a  number  of  threads  may  thus  be  twisted  at  once  by  one  master 
wheel.  The  principal  nicety  consists  in  so  regulating  the  movements  that  the  successive 
volutions  of  the  flatted  wire  on  each  thread  may  just  touch  one  another,  and  form  a 
continuous  covering.  The  French  silver  for  gilding  is  said  to  be  alloyed  with  5  or  6 
pennyweights,  and  ours  with  12  pennyweights  of  copper  in  the  pound  troy.  The  gold 
is  applied  in  leaves  of  greater  or  less  thickness,  according  to  the  quahly  of  the  gilt  wire. 
The  smallest  proportion  formerly  allowed  in  this  country  by  act  of  parliament,  was  100 
grains  of  gold  to  one  pound,  or  5760  grains  of  silver ;  but  more  or  less  may  now  be  used. 
The  silver  rod  is  encased  in  the  gold  leaf,  and  the  compound  cylinder  is  then  drawn  into 
round  wire  down  to  a  certain  size,  which  is  afterwards  flatted  in  a  rolling  mill  such  as  is 
described  under  Mint. 

The  liquor  employed  by  goldsmiths  to  bring  out  a  rich  color  upon  the  surface  of  their 
trinkets,  is  made  by  dissolving  1  part  of  sea  salt,  1  part  of  alum,  2  parts  of  nitre,  in  3  or 
4  of  water.  This  pickle  or  sauce,  as  it  is  called,  takes  up  not  only  the  copper  alloy,  but 
a  notable  quantity  of  gold  ;  the  total  amount  of  which  in  the  Austrian  empire,  has  been 
estimated  annually  at  47,000  francs.  To  recover  this  gold,  the  liquor  is  diluted  with  at 
least  twice  its  bulk  of  boiling  water ;  and  a  solution  of  very  pure  green  sulphate  of  iron 
is  poured  into  it.  The  precipitate  of  gold  is  washed  upon  a  filler,  dried,  and  purified  by 
melting  in  a  crucible  along  with  a  mixture  of  equal  parts  of  nitre  and  borax. 

Gold  refining. — The  following  process  has  been  patented  as  a  foreign  invention  by 
Mr.  W.  E.  Newton  in  Januarv,  1851. 

It  consists,  1,,  in  reducing  argentiferous  or  any  other  gold  bullion  to  a  granulated, 
or  spongy,  or  disintegrated  molecular  condition  by  fusion  therewith  of  zinc,  or  some 
other  metal  baser  than  silver,  and  the  subsequent  removal  of  the  zinc  by  dilute  sulphuric 
or  other  acid ;  that  is,  the  reducing  of  the  gold  bullion  to  a  state  to  allow  of  the  re- 
moval by  acids  of  the  silver  and  other  impurities  contained  therein,  so  as  to  fit  it  for 
coinage  and  other  purposes  without  quartation  with  silver  or  any  other  interineduite 
process.    And 

2.,  in  pulverizing  by  grinding  or  concussion  gold  bullion,  rendered  brittle  by  union 
with  lead,  solder,  or  other  suitable  metal,  the  silver  and  other  impurities  being  removed 
by  acids  in  this  as  in  the  preceding  case,  and  recovered  from  the  acid  solution  by  any  of 
the  known  chemical  means. 

Tliis  operation,  if  properly  conducted,  will  produce  fine  ductile  gold  in  a  state  of 
great  purity ;  that  is,  containing  from  985  to  995  per  cent,  of  pure  gold. 

GONG-GONG ;  or  tam-tam  of  the  Chinese  ;  a  kind  of  cymbal  made  of  a  copper 
alloy,  described  towards  the  end  of  the  article  Copper. 

GONIOMETER,  is  the  name  of  a  little  instrument  made  either  on  mechanical  or 
optical  principles,  for  measuring  the  angles  of  crystals.  It  is  indispensable  to  the  mine- 
ralogist. 

GRADUATOR,  called  by  its  contriver  M.  Wagenmann,  Essighilder,  which  means, 
in  German,  vinegar-maker,  is  represented  in  fig.  739.  It  is  an  oaken  tub,  5^  feet  high, 
Z^  feet  wide  at  top,  and  3  at  bottom,  set  upon  wooden  beams,  which  raise  its  bottom 


966 


GRAUWACKE. 


about  U  inches  from  the  floor.  At  a  distance  of  16  inches 
above  the  bottom,  the  tub  is  pierced  with  a  horizontal  row 
of  8  equidistant  round  holes,  of  an  inch  in  diameter.  At  6 
inches  beneath  the  mouth  of  the  tub,  a  thick  beech-wood 
hoop  is  made  fast  to  the  inner  surface,  which  supports  a 
circular  oaken  shelf,  leaving  a  space  round  its  edge  of  IJ^ 
inches,  which  is  stuffed  water-tight  with  hemp  or  tow.  In 
this  shelf,  400  holes  at  least  must  be  bored,  about  i  of  an 
inch  in  diameter,  and  1^  inches  apart;  and  each  of  these 
must  be  loosely  filled  with  a  piece  of  packthread,  or  cotton 
wick,  which  serves  to  filter  the  liquid  slowly  downwards. 
3ln  the  same  shelf  there  are  likewise  four  larger  holes  of 
1^  inches  diameter,  and  18  inches  apart,  each  of  which  re- 
ceives air-tight  a  glass  tube  3  or  4  inches  long,  having  its 
ends  projecting  above  and  below  the  shelf.  These  tubes  serve  to  allow  the  air  that 
enters  by  the  8  circumferential  holes,  to  circulate  freely  through  the  graduator.  ITie 
mouth  of  the  tube  is  covered  with  a  wooden  lid,  in  whose  middle  is  a  hole  for  the  insertion 
of  a  funnel,  when  the  liquor  of  acetification  requires  to  be  iniroduced.  One  inch  above 
the  bottom,  a  hole  is  bored  for  receiving  a  syphon-formed  discharge  pipe,  whose  upper 
curvature  stands  one  inch  below  the  level  of  the  holes  in  the  side  of  the  tub,  to  prevent 
the  liquor  from  rising:  so  high  as  to  overflow  through  them.  The  syphon  is  so  bent  as  to 
retain  a  body  of  liqiior  12  inches  deep  above  the  bottom  of  the  tub,  and  to  allow  the  ex 
cess  only  to  escape  into  the  subjacent  receiver.  In  the  upper  part  of  the  graduator,  but 
under  the  shelf,  the  bulb  of  a  thermometer  is  inserted  through  the  side,  some  way  into 
the  interior,  having  a  scale  exteriorly.  The  whole  capacity  of  the  cask  from  the  bottom 
up  to  within  one  inch  of  the  perforated  shelf,  is  to  be  filled  with  thin  shavings  of  beech 
wood,  grape  stalks,  or  birch  twigs,  previously  imbued  with  vinegar.  The  manner  of  using 
this  simple  apparatus  is  described  under  Acetic  Acid. 

GRANITE  is  a  compound  rock,  essentially  composed  of  quartz,  feldspar,  and  mica, 
each  in  granular  crystals.  It  constitutes  the  lowest  of  the  geological  formations,  and 
therefore  has  been  supposed  to  serve  as  a  base  to  all  ihe  rest.  It  is  the  most  durable 
material  for  buildins,  as  many  of  the  ancient  Egyptian  monuments  testify. 

The  obelisk  in  the  place  of  Saint  Jean  de  Lateran  at  Rome,  which  was  quarried  at 
Syene,  under  the  reian  of  Zetus.  king  of  Thebes,  1300  years  before  the  Christian  era  j 
and  the  one  in  the  place  of  Saint  Pierre,  also  at  Rome,  consecrated  to  the  Sun  by  a  son 
of  Sesostris,  have  resisted  the  weather  for  fully  3000  years.  On  the  other  hand  there  are 
many  granites,  especially  those  in  which  feldspar  predominates,  which  crack  and  crumble 
down  in  the  course  of  a  few  years.  In  the  same  mountain,  or  even  in  the  same  quarry, 
granites  of  very  different  qualities  as  to  soundness  and  durability  occur.  Some  of  the 
granites  of  Cornwall  and  Limousin  readily  resolve  themselves  into  a  white  kaolin  or 
argillaceous  matter,  from  which  pottery  and  porcelain  are  made. 

Granite,  when  some  time  dug  out  of  the  quarry,  becomes  refractory,  and  diflScult  to  cut. 
When  this  rock  is  intended  to  be  worked  it  should  be  kept  under  water  ;  and  that  variety 
ought  to  be  selected  which  contains  least  feldspar,  and  in  which  the  quartz  or  gray  crys- 
tals predominate.  ,  . 
GRANULATION  is  the  process  by  which  metals  are  reduced  to  minute  grains.  It  is 
effected  by  pouring  them,  in  a  melted  state,  through  an  iron  cullender  pierced  with  small 
holes,  into  a  body  of  water ;  or  directly  upon  a  bundle  of  twigs  immersed  in  water.  In 
this  way  copper  is  granulated  into  bean  shot,  and  silver  alloys  are  granulated  preparatory 
to  Parting  *  which  see. 

GRAPHITE  {Plomb'agiMyFr, ;  Reissblei,  Germ.)  is  a  mineral  substance  of  a  lead  or 
iron  gray  color,  a  n.etallic  lustre,  soft  to  the  touch,  and  staining  the  fingers  with  a  lead 
gray  hue.  Spec.  grav.  2-08  to  2-45.  It  is  easily  scratched,  or  cut  with  a  steel  edge,  and 
displays  the  metallic  lustre  in  its  interior.  Burns  with  great  difficulty  in  the  outward 
flame  of  the  blow-pipe.  It  consists  of  carbon  in  a  peculiar  state  of  aegreaation,  with  an 
extremely  minute  and  apparently  accidental  impregnation  of  iron.  Graphite,  called  also 
plumbaso  and  black  lead,  occurs  in  gneiss,  mica  slate,  and  their  subordinate  clay  slates 
and  lime  sUrnes ;  in  the  form  of  masses,  veins,  and  kidney-shaped  disseminated  pieces; 
as  also  in  the  transition  slate,  as  at  Borrodale  in  Cumberland,  where  the  most  precious 
deposite  exists,  both  in  reference  to  extent  and  quality,  for  making  pencils.  It  has  been 
found  also  among  the  coal  strata,  as  near  Cumnock  in  Ayrshire.  This  substance  is  em- 
ployed for  counteracting  friction  between  rubbing  surfaces  of  wood  or  metal,  for  making 
crucibles  and  portable  furnaces,  for  giving  a  gloss  to  the  surface  of  cast  iion,  &c.  See 
Plumbago,  for  some  remarks  concerning  the  Cumberland  mine. 

GRAUWACKE,  or  GREYWACKE,  is  a  rock  formation,  composed  of  pieces  of  quartz, 
flinty  slate, feldspar,  and  clay  slate,  cemented  by  a  clay-slate  basis;  the  pieces  varying  id 
size  from  small  grains  to  a  hen's  egg. 


GREEN  PAINTS. 


957 


GRAY  DYE.  (Teinture  grise,  Fr. ;  Graufdrbe,  Germ.)  The  gray  dyes,  in  theii 
numerous  shades,  are  merely  various  tints  of  black,  in  a  more  or  less  diluted  state,  from 
the  deepest  to  the  lightest  hue.  ,     /.      i,  u 

The  dyeing  materials  are  essentially  the  tannic  and  gallic  acid  of  galls  or  other 
astringents,  along  with  the  sulphate  or  acetate  of  iron,  and  occasionally  wine  stone. 
Ash  gray  is  given  for  30  pounds  of  woollen  stuff,  by  one  pound  of  gall  nuts,  ^  'h.  of  wine 
stone' (crude  tartar),  and  2^  lbs.  of  sulphate  of  iron.  The  galls  and  the  wine  stone  being 
boiled  with  from  70  to  80  pounds  of  water,  the  stuff  is  to  be  turned  through  the  de- 
coction at  a  boiling  heal  for  half  an  hour,  then  taken  out,  when  the  bath  being  re- 
freshed with  cold  water,  the  copperas  is  to  be  added,  and,  as  soon  as  it  is  dissolved,  the 
Stuff  is  to  be  put  in  and  fully  dyed.  Or,  for  36  pounds  of  wool ;  2  pounds  of  tartar, 
h  pound  of  galls,  3  pounds  of  sumach,  and  2  pounds  of  sulphate  of  iron  are  to  be 
taken.  The  tartar  being  dissolved  in  80  pounds  of  boiling  water,  the  wool  is  to  be 
turned  through  the  solution  for  half  an  hour,  and  then  taken  out.  The  copper  being 
filled  up  to  its  former  level  with  fresh  water,  the  decoction  of  the  galls  and  sumach  is  to 
be  p<.ured  in,  and  the  wool  boiled  for  half  an  hour  in  the  bath.  The  wool  is  then  taken 
out,  while  the  copperas  is  being  added  and  dissolved ;  after  which  it  is  replaced  in  the 
bath,  and  dyed  gray  with  a  gentle  heat. 

If  the  gray  is  to  have  a  yellow  cast,  instead  of  the  tartar,  its  own  weight  of  alum  is  to 
be  taken ;  instead  of  the  galls,  one  pound  of  old  fustic ;  instead  of  the  copperas,  |  of  a 
pound  of  Salizburg  vitriol,  which  consists,  in  22|  parts,  of  17  of  sulphate  of  iron,  and  5| 
of  sulphate  of  copper;  then  proceed  as  above  directed.  Or  the  stuff  may  be  first  stained 
in  a  bath  of  fustic,  next  in  a  weak  bath  of  galls  with  a  little  alum ;  then  the  wool  being 
Uken  out,  a  little  vitriol  (common  or  Saltzburg)  is  to  be  put  in,  previously  dis.solved  ia 
a  decoction  of  logwood ;  and  in  this  bath  the  dye  is  completed. 

Pearl  gray  is  produced  by  passing  the  stuff  first  through  a  decoction  of  sumach  and 
logwood  (2  lbs.  of  the  former  to  ^jne  of  the  latter),  afterwards  through  a  dilute  solution 
of  sulphate  or  acetate  of  iron ;  and  finishing  it  in  a  weak  bath  of  weld  containing  a  little 
alum.  Mouse-gray  is  obtained,  when  with  the  same  proportions  as  for  ash-gray,  a  small 
quantity  of  alum  is  introduced. 

For  several  other  shades,  as  tawny-gray,  iron-gray,  and  slate-gray,  the  stuff  must  re- 
ceive a  previous  blue  ground  by  dipping  it  in  the  indigo  vat ;  then  it  is  passed  first 
through  a  boiling  bath  of  sumach  with  galls,  and  lastly  through  the  jame  bath  at  a  lower 
temperature  after  it  has  received  the  proper  quantity  of  solution  of  iron. 

For  dyeing  silk  gray,  fustet,  logwood,  sumach,  and  elder-tree  bark,  are  employed 
instead  of  galls.  Archil  and  annotto  are  frequently  used  to  soften  and  beautify  the 
tint. 

The  mode  of  producing  gray  dyes  upon  cotton  has  been  sufficiently  explained  in  the 
articles  Calico  Printing  and  Dyeing. 

GREEN  DYE  is  produced  by  the  mixture  of  a  blue  and  yellow  dye,  the  blue 
being  first  applied.    See  Dyeing;   as  also   Blue  and   Yellow   Dyes,  and  Calico 

Printing.  .  •  v  • 

GREEN  PAINTS.  (Couleurs  vertes^  Fr. ;  Grune  pigmented  Germ.)  Green,  which  is 
so  common  a  color  in  the  vegetable  kingdom,  is  very  rare  in  the  mineral.  There  is  only 
one  metal,  copper,  which  affords  in  its  combinations  the  various  shades  of  green  in 
general  use.  The  other  metals  capable  of  protlucing  this  color  are,  chromium  in  its  prot- 
oxyde,  nickel  in  its  hydrated  oxyde,  as  well  as  its  salts,  the  seleniate,  arseniate,  and  sul- 
phate ;  and  titanium  in  its  prussiate. 

Green  pigments  are  prepared  also  by  the  mixture  of  yellows  and  blues ;  as,  for  ex- 
ample, the  green  of  Rinman  and  of  Gellert,  obtained  by  the  mixture  of  cobalt  blue,  and 
flowers  of  zinc ;  that  of  Barth,  made  with  yellow  lake,  Prussian  blue,  and  clay ;  but 
these  paints  seldom  appear  in  the  market,  because  the  greens  are  generally  extemporaneous 
preparations  of  the  artists.  *  .  . 

Mountain  green  consists  of  the  hydrate,  oxyde,  or  carbonate  of  copper,  either  factitious, 

or  as  found  in  nature. 

Bremen  or  Brunswick  green  is  a  mixture  of  carbonate  of  copper  with  chalk  or  lime, 
and  sometimes  a  little  magnesia  or  ammonia.  It  is  improved  by  an  admixture  of  white 
lead.  It  may  be  prepared  by  adding  ammonia  to  a  mixed  solution  of  sulphate  of  copper 
and  alum. 

Frise  green  is  prepared  with  sulphate  of  copper  and  sal  ammoniac. 

Miltis  green  is  an  arseniate  of  copper ;  made  by  mixing  a  solution  of  acetate  or  sul- 
phate of  copper  with  arsenite  of  potash.    It  is  in  fact  Scheele's  green. 

Sap  green  is  the  inspissated  juice  of  buckthorn  berries.    These  are  allowed  to  fer- 
ment for  8  days  in  a  tub,  then  put  in  a  press,  adding  a  little  alum  to  the  juice,  and  con 
centrated  by  gentle  evaporation.    It  is  lastly  put  up  in  pigs'  bladders,  where  it  becomes 
dry  and  lard 


958 


GUANO. 


GUANO. 


959 


Schweinfurt  green  ;  sec  Scuwkinfukt. 

Verona  green  is  merely  a  variety  of  the  mineral  called  green  earth 

GREEN  VITRIOL  is  sulphate  of  iron  in  green  crystals. 

GROW  AN.    The  name  given  by  the  Cornish  miners  to  granite,  and  to  rocks  of  like 

structure.  .  ,  i 

GUAIAC,  {Gaiac,  Fr. ;  Chuijaharz,  Germ.)  is  a  resin  which  exudes  from  the 
trunk  of  the  Gtiaiacum  officinaUy  a  tree  which  grows  in  the  West  India  islands.  It 
comes  to  us  in  large  green idi-brown,  semi-transparent  lumps,  having  a  conchoidal  or 
splintery  fracture,  brittle  and  easy  to  pulverize.  It  has  an  aromatic  smell,  a  bitterish, 
acrid  taste,  melts  with  heat,  and  has  a  spec  grav.  of  from  1-20  to  122.  It  consists  of 
67-88  carbon;  7  05  hydrogen;  and  25'07  oxygen;  and  contains  two  different  resins, 
the  one  of  which  is  soluble  in  all  proportions  in  ammonia,  and  the  other  forms,  with 
water  of  ammonia,  a  tarry  consistenced  mixture.  It  is  soluble  in  alkaline  lyes,  in  al- 
cohol, incompletely  in  ether,  still  less  so  in  oil  of  turpentine,  and  not  at  all  in  fat  oils. 
Its  chief  use  is  in  medicine. 

GUANO.  This  extraordinary  excremenlitious  deposite  of  certain  sea-fowls,  which 
occurs  in  immense  quantities  upon  some  parts  of  the  coasts  of  Peru,  Bolivia,  and 
Africa,  has  lately  become  an  object  of  great  commercial  enterprise,  and  of  intense 
interest  to  our  agricultural  world.  Four  or  five  years  ago  it  was  exhibited  and  talked 
of  merely  as  a  natural  curiosity.  No  one  could  then  have  imagined  that  in  a  short 
period  it  would  be  imported  from  the  coasts  of  the  Pacific  in  such  abundance,  and  at 
such  a  moderate  price,  as  to  cheer  by  its  fertilizing  powers  the  languid  and  depressed 
spirits  of  the  farmers  throughout  the  United  Kingdom.  Such,  however,  is  now  the 
result,  as  attested  by  the  concurring  reports  of  almost  all  the  agricultural  societies 
of  Great  Britain  and  Ireland.  No  less  than  28,500  tons  of  guano  have  been  already 
imported  from  Peru  and  Bolivia,  1,500  from  Chili,  and  8,000  from  Africa,  altogether 
38,000  tons,  while  more  is  on  the  way.  The  store  of  it,  laid  up  from  time  immemorial 
in  the  above  localities,  seems  to  be  quite  inexhaustible ;  especially  since  it  is  receiving 
constant  accessions  from  myriads  of  cormorants,  cranes,  &c. 

Having  been  much  occupied  w^ith  the  chemical  analyses  of  guano  during  the  last 
two  years  for  Messrs.  Gibbs,  of  London,  and  Messrs.  Myers,  of  Liverpool,  who  are  the 
co-agents  of  the  Peruvian  and  Bolivian  governments,  I  have  enjoyed  favorable  oppor- 
tunities of  examining  samples  of  every  description,  and  hope  to  show  that  many  of  the 
analyses  of  guano  hitherto  published  fiave  been  made  upon  specimens  not  in  their  nor- 
mal or  sound  state,  like  the  best  imported  by  the  above  houses  from  Chincha  and  Bolivia, 
but  'n  a  certain  state  of  cremacausis  and  decay. 

Huano,  in  the  language  of  Peru,  signifies  dung;  a  word  spelt  by  the  Spaniards  guano. 
The  natives  have  employed  it  as  a  manure  from  the  remotest  ages,  and  have  by  its  means 
given  fertility  to  the  otherwise  unproductive  sandy  soils  along  their  coasts.  While  Peru 
was  governed  by  its  native  incas,  the  buds  were  protected  from  violence  by  severe  laws. 
The  ptnishment  of  death  was  decreed  to  persons  who  dared  to  land  on  the  guanifer- 
ous  islands  during  the  breeding  period  of  the  birds,  and  to  all  persons  who  destroyed 
them  at  any  time.  Overseers  were  appointed  by  the  government  to  take  care  of  the 
guano  districts,  and  to  assign  to  each  claimant  his  due  share  of  the  precious  dung.  The 
celebrated  Baron  Von  Humboldt  first  brought  specimens  to  Europe  in  1804,  which  he 
sent  for  examination  to  Foureroy,  Vauquelin,  and  Klaproth,  the  best  analytical  chem- 
ists of  the  day;  and  he  spoke  of  it  in  the  following  terms  :  "  The  guano  is  deposited  m 
layers  of  50  or  60  feet  thick  upon  the  granite  of  many  of  the  South  sea  islands  oft  the 
coast  of  Peru.  During  300  years  the  coast  birds  have  deposited  guano  only  a  few 
lines  in  thickness.  This  shows  how  great  must  have  been  the  number  of  birds,  and 
how  many  centuries  must  have  passed  over  in  order  to  form  the  present  guano-beds." 
The  strata  have  undergone  many  changes,  according  to  the  length  of  tune  they  have 
been  deposited.  Here  and  there  they  are  covered  with  silicious  sand,  and  have  thu* 
been  protected  from  the  influence  of  the  weather  ;  but  in  other  places,  they  have  lain 
open  to  the  action  of  light,  air,  and  water,  which  have  produced  important  changes 
upon  them.  Fresh  guano  is  of  a  whitish  or  very  pale  drab  color,  but  it  becomes  pro- 
gressively browner  and  browner  by  the  joint  influence  of  the  above  three  atmospheri- 
cal agents.  Only  one  guano  examined  by  Foureroy  and  Vauquelin  was  found  to  con- 
tain a  fourth  of  its  weight  of  uric  acid  combined  with  ammonia,  whence  that  appears 
to  have  been  well  selected  by  Baron  Von  Humboldt.  They  also  found  phosphates  of 
ammonia,  of  lime,  with  urate  and  oxalate  of  ammonia,  and  some  other  const.Aients  of 
little  value  in  agriculture.  Klaproth's  analysis  reported  16  per  cent,  of  urate  of  ammo- 
nia, no  less  than  12-75  of  oxalate  of  lime,  10  of  phosphate  of  lime,  32  of  clay  and  sand, 
jvith  28-75  of  water  and  indeterminate  organic  matter.  From  the  great  proportion  of 
2lay  and  sand,  Klaproth's  sample  of  guano  was  obviously  not  genuine.  I  have  met 
▼ith  no  specimen  of  Peruvian  guano  that  contained  any  appreciable  quantity  of  clay, 
and  none  that  contained  above  4  or  5  per  cent,  of  silicious  sand. 


To  Mr.  Bland,  of  the  firm  of  Messrs.  Myers  and  Co.,  I  am  indebted  for  the  following 

valuable  information : —  ,         •  v  j 

The  Chincha  islands,  which  afford  the  best  Peruvian  guano,  are  three  in  number,  and 
lie  in  one  line  from  north  to  south,  about  half  a  mile  apart.  Each  island  is  from  five  to 
six  miles  in  circumference,  and  consists  of  granite  covered  with  guano  in  some  places  to 
a  hei<'ht  of  200  feet,  in  successive  horizontal  strata,  each  stratum  being  from  3  to  10 
inches  thick,  and  varying  in  color  from  light  to  dark  brown.  No  earthy  matter 
whatever  is  mixed  with  this  vast  mass  of  excrement.  At  Mr.  Bland's  visit  to  these 
islands  in  1842,  he  observed  a  perpendicular  surface  of  upward  of  100  feet  of  perfectly 
uniform  aspect  from  top  to  bottom.  In  some  parts  of  these  islands,  however,  the  deposite 
does  not  exceed  3  or  4  feet  in  thickness.  In  several  places,  where  the  surface  of  the 
guano  is  100  feet  or  more  above  the  level  of  the  sea,  it  is  strewed  here  and  there  with 
masses  of  granite,  like  those  from  the  Alpine  mountains,  which  are  met  with  on  the  slopes 
of  the  Jura  chain.  These  seem  to  indicate  an  ancient  formation  for  the  guano,  and  ter- 
raqueous convulsions  since  that  period.  No  such  granite  masses  are  found  imbedded 
within  the  guano,  but  only  skeletons  of  birds.  .     ^       ^     ,  r     • 

The  good  preservation  of  the  Chincha  guano  is  to  be  ascribed  to  the  absence  or  ram ; 
which  rarelv,  if  ever,  falls  between  the  latitude  of  W  south,  where  these  islands  lie, 
about  10  miles  from  the  main  land,  and  the  latitude  of  Paquica,  on  the  island  cf  Bo- 
livia in  21°  S.  L.  By  far  the  soundest  cargoes  of  guano  which  I  have  analysed  have 
come  from  Chincha  and  Bolivia.  Beyond  these  limits  of  latitude  where  rain  falls  in 
greater  or  less  abundance,  the  guano  is  of  less  value— and  what  has  been  imported  from 
Chili  has  been  found  by  me  far  advanced  in  decay— most  of  the  ammonia  and  azotised 
animal  substances  having  been  decomposed  by  moisture,  and  dissipated  in  the  air  (by  the 
eremacausis  of  Liebig),  leaving  phosphate  of  lime  largely  to  predominate  along  with 
effete  organic  matter.  The  range  of  the  American  coast  from  which  the  guano  is  taken 
must  therefore  be  well  considered ;  and  should  not  extend  much  beyond  the  Chincha 
islands  as  the  northern  limit,  and  Paquica,  in  Bolivia,  as  the  southern. 

The  relative  estimation  of  ^uano  and  nitrate  of  soda  among  the  Peruvians  is  well 
shown  by  the  following  fact  communicated  to  me  by  Mr.  Bland  :  "  N^ar  the  coast  of 
Peru,  about  45  miles  from  Iquique  (the  shipping  port  of  guano)  there  is  the  chief  deposite 
of  nitrate  of  soda.  The  farmers,  who  collect  and  purify  this  natural  product,  carry  it 
to  the  place  of  shipment,  and  always  require  to  be  paid  in  return  with  an  equivalent 
.  quantity  of  guano,  with  which  they  manure  their  land,  to  the  exclusion  of  the  far 
cheaper  nitrate  of  soda.  We  can  not  be  surprised  at  this  preference,  when  we  learn 
that  in  the  valley  of  Chancay,  about  40  miles  distant  from  Lima,  the  soil  produces, 
when  farmed  with  irrigation  in  the  natural  way,  a  return  upon  maize  of  only  15  for  1 ; 
whereas,  with  the  aid  of  guano,  it  produces  500  for  1 !  Hence  the  Peruvian  proverb: 
Huano,  though  no  saint,  works  many  miracles. 

In  the  pamphlet  recently  published  by  Messrs.  Gibbs  and  Myers,  -.ntitled  «  Peruvian 
and  Bolivian  Guano,  its  nature,  properties,  and  results,"  we  have  a  ver>-  interesting 
view  of  the  best  established  facts  with  regard  to  its  operation  and  effects  upon 
«A'ery  variety  of  soil,  and  in  every  variety  of  circumstance,  as  ascertained  by  th«^  most 
intelligent  agriculturists  of  the  United  Kingdom.  The  general  conclusion  that  may 
t>e  fairly  deduced  from  the  whole  evidence  is,  that  good  guano  will,  under  judicious 
application,  increase  the  crops  of  grain,  turnips,  potatoes,  and  grass,  by  about  33  per 
cent. ;  and  with  its  present  price  of  10/.  per  ton,  at  a  cost  considerably  under  the  aver- 
age cost  of  all  other  manures,  whether  farm-yard  dung  and  composts,  or  artificial  com- 
pounds. Guano  is,  moreover,  peculiarly  adapted  to  horticultural  and  floricultural  im- 
provement, by  its  relative  cleanliness  and  facility  of  application. 

The  following  observations  upon  guano,  by  Dr.  Von  Martins,  of  Munich,  addressed 
to  the  agricultural  society  of  Bavaria,  deserve  attention.  Among  animal  manures, 
says  he,  it  clearly  claims  the  first  place.  It  is  uncommonly  rich  in  ammoniacal  salts, 
which  act  very  favorable  on  vegetation.  The  ease  with  which  these  salts  are  decom- 
posed, and  exhale  their  ammonia  into  the  air,  is  by  him  assigned  as  the  reason  why 
plants  manured  with  guano  generally  present  early  in  the  morning  accumulations  of 
dew  on  the  points  of  their  leaves.  The  guano  absorbs  the  atmospheric  vapor,  as  well 
as  carbonic  acid  ;  whereby  it  becomes  so  valuable  a  manure  in  dry  barren  regions.  If 
we  compare  guano  with  other  excrementitious  manures,  we  shall  find  it  far  preferable 
to  those  afforded  by  man  or  other  mammalia,  which  do  not  generally  contain  more  than 
20  per  cent,  of  food  that  can  be  appropriated  by  plants.  It  is  therefore  five  tiines  better 
than  night-soil,  and  also  veiy  superior  to  the  French  poudrette,  which,  being  dried  night- 
soil,  loses,  through  putrefaction  and  evaporation,  the  greater  proportion  of  its  ammonia- 
cal elements.  In  birds,  the  excretions  both  of  the  kidneys  and  intestines  are  contained 
in  the  cloaca ;  wherebv  the  volatile  elements  of  the  former  get  combined  with  Uiemore 
fixed  components  of  the  latter.  The  guano  is  also  a  richer  manure,  on  account  of  its 
being  produced  bv  sea-fowl,  which  live  entirely  on  fish,  without  admixture  of  vegetable 


960 


GUANO. 


1 


II 


matter.  The  exposure  also  of  the  guano  as  soon  as  deposited  to  the  heat  of  a  tropical 
dun,  in  a  rainless  climate,  prevents  the  components  from  fermenting,  and  mummifies 
them,  so  to  speak,  immediately  into  a  concrete  substance  not  susceptible  of  decomposition 
till  it  gets  moisture  ;  whereas  the  dung  of  our  dove-cotes  suffers  a  considerable  loss  by 
exposure  to  our  humid  atmosphere.  But  in  their  action  on  vegetation,  and  in  their 
chemical  composition,  these  two  bird  excrements  are  analogous.  Davy  found  in  fresh 
dove-cote  manure  23  parts  in  100  soluble  in  water,  which  yielded  abundance  of  car- 
bonate  of  ammonia  by  distillation,  and  left  carbonaceous  matter,  saline  matter,  princi- 
pally common  salt,  and  carbonate  of  lime  as  a  residuum.  Pigeons'  dung  readily  fer- 
ments, but  after  fermentation  afforded  only  8  per  cent,  of  soluble  matter,  which  gave 
proportionably  less  carbonate  of  ammonia  in  distillation  than  the  dung  recently  voided. 
Dr.  Von  Martins  proceeds  to  compare  the  proportion  of  soluble  salts  in  guano  and 
pigeons'  dung,  and  thinks  that  by  that  comparison  alone  he  can  establish  the  superiority 
of  the  former ;  but  he  should  have  considered  that  the  insoluble  urate  of  ammonia, 
which  is  so  powerful  and  copious  a  constituent  of  good  guano,  and  is  present  in  much 
smaller  proportion  in  pigeons'  dung,  is  sufficient  of  itself  to  turn  the  balance  greatly  in 
favor  of  the  Peruvian  manure.  His  general  estimate,  however,  that  the  manuring  power 
of  genuine  guano  is  four  times  greater  than  that  of  pigeons'  dung,  is  probably  not  ^ride 
of  the  truth.  Besides  the  above-mentioned  constituents,  guano  derives  no  small  por- 
tion of  its  fertilizing  virtue  from  the  great  store  of  phosphoric  acid  which  it  contains, 
in  various  states  of  saline  combination,  with  lime,  magnesia,  and  ammonia.  Of  all  the 
principles  furnished  to  plants  by  the  soil,  the  phosphates  are,  according  to  Liebig,  the 
most  important.  They  afford,  so  to  speak,  the  bones  and  sinews  of  vegetable  bodies,  while 
ammonia  supplies  them  with  their  indispensable  element,  azote.  Their  carbon,  hydrogen, 
and  oxygen,  are  derived  from  the  air  and  water.  Those  products  of  vegetation  which 
are  most  nutritious  to  man  and  herbiverous  animals,  such  as  bread-corn,  beans,  peas,  and 
lentils,  contain  the  largest  proportion  of  phosphates.  The  ashes  of  these  vegetable 
substances  afford  no  alkaline  carbonates.  A  soil  in  which  phosphates  are  not  present, 
is  totally  incapable  of  producing  the  above  cereals.  Agreeably  to  these  views,  Liebig 
believes  that  the  importation  of  1  cwt.  of  guano  is  equivalent  to  the  importation  of  8 
cwts.  of  wheal ;  so  that  1  cwt.  of  that  manure  assumes,  with  due  culture,  the  form  of 
8  cwts.  of  substantial  foodtfor  man. 

Since  all  these  testimonies  concur  to  place  this  remarkable  excrementitious  product  in 
fuch  high  estimation,  it  becomes  a  paramount  duty  of  the  chemist  to  investigate  its  com- 
position, and  to  discover  certain  means  of  distinguishing  what  maybe  termed  the  sound 
or  normal  state  of  guano,  from  the  decomposed,  decayed,  and  effete  condition.  The 
analysis  by  Fourcroy  and  Vauquelin  of  a  sample  of  guano  presented  to  them  by  Baron 
Von  Humboldt,  gave  the  following  composition  in  100  parts  : — 


Urate  of  ammonia         -            -  - 

Oxalate  of  ammonia       -            -  - 

Oxalate  of  lime              -             -  . 
Phosphate  of  ammonia 

Phosphate  of  ammonia  and  magnesia  - 

Sulphate  of  potash        -            -  - 


soaa 


Sol  ammoniac    - 
Phosphate  of  lime 
Clay  and  sand 
Water  and  organic  matters 


9-0 

10-6 

7-0 

6-0 

5*6 

3-3 

4-2 

14-3 

4-7 
32-3 


til 


How  different  are  these  constituents  from  those  assigned  by  Klaproth — a  no  less  skil- 
ful analyst  than  the  French  chemists  !  and  how  much  this  difference  shows  not  only  the 
complexity  of  the  substance,  but  its  very  variable  nature ! 

The  general  results  of  an  analysis  by  Professor  Johnston,  published  in  his  paper  on 
guano,  in  the  3d  part  of  the  2d  vol.  of  the  Journal  of  the  Royal  Agricultural  Society 
of  England,  are  as  follows : — 

Ammonia  -  -  -  -  - 

Uric  acid  ---_-_- 

Water  and  carbonic  and  oxalic  acids,  &c.,  expelled  by  a  red  heat 
Common  salt,  with  a  little  sulphate  and  phosphate  of  soda 
Phosphate  of  lime,  &c.  -  -  -  . 

00-0 

The  specimen  of  guano  represented  by  this  analysis  must  have  been  (&i  advanced  in 
decomposition,  as  shown  by  the  very  scanty  portion  of  uric  acid ;  and  musv  have  been 
©riginally  impure  {.spurious  ?)  from  the  large  proportion  of  conmion  salt,  of  which  I  ha\  e 


GUANO. 


961 


not  found  above  4  or  6  per  cent,  in  any  of  the  genuine  guanos  which  I  have  had  occasioR 
to  analyze.  In  another  sample,  Professor  Johnston  found  44-4  of  phosphate  of  lime, 
with  a  little  phosphate  of  magnesia,  and  carbonate  of  lime.  These  results  resemble, 
to  a  certain  degree,  those  which  I  have  obtained  in  analyzing  several  samples  of  Chilian 
and  African  guanos,  especially  in  the  predominance  of  the  earthy  phosphates.  The  pro- 
portion of  ammonia  which  can  be  extracted  by  the  action  of  hydrate  of  soda  and  quick- 
lime, at  an  elevated  temperature,  is  the  surest  criterion  of  the  soundness  of  the  guano ; 
for  by  this  process  we  obtain  not  only  the  readi/  formed  ammonia,  from  its  several  saline 
compounds,  but  also  the  ammonia  producible  from  its  uric  acid,  and  undefined  animal 
matter.  These  two  latter  quantities  have  been  hitherto  too  little  regarded  by  most 
analysts,  though  they  constitute  the  most  durable  fund  of  azote  for  the  nutrition  of 
plants.  Uric  acid,  and  urate  of  ammonia,  which  contains  10-llths  of  uric  acid,  being 
both  nearly  insoluble  in  water,  and  fixed  at  ordinary  temperatures,  continue  to  give 
out  progressively  to  plants  in  the  soil,  the  azote,  of  which  they  contain  fully  one-third 
of  their  weight.  Under  the  influence  of  oxygen  and  a  certain  temperature,  uric  acid 
passes  through  a  very  remarkable  series  of  transformation  ;  producing  allantoin,  urea, 
and  oxalic  acid,  which  eventually  becomes  carbonic  acid.  These  changes  are  produci- 
ble immediately  by  the  action  of  boiling  water  and  peroxide  of  lead.  From  these 
metamorphoses,  we  can  readily  understand  how  much  oxalate  of  ammonia  and  of  lime  is 
reported  in  many  analyses  of  guano,  though  none,  I  believe,  is  to  be  found  in  the  normal 
state,  as  it  is  occasionally  imported  from  the  Chincha  Islands  and  Bolivia ;  nor  were  any 
oxalates  found  in  the  dung  of  the  gannet,  as  analyzed  by  Dr.  Wollaston,  or  of  the  sea 
eagle,  according  to  the  following  analysis  of  Coindet:  ammonia,  921  per  cent.;  uric  acid, 
84-65 ;  phosphate  of  lime,  61 3=1  GO.  The  Peruvian  sea-fowl,  by  feeding  exclusively  on 
fish,  would  seem  to  swallow  a  large  proportion  of  earthy  phosphates ;  since,  in  the  purest 
guano  that  has  come  in  my  way,  I  have  found  these  salts  to  amount  to  from  10  to  15  per 
cent  '^ 

Dr.  Von  Martius  proposes  to  use  the  degree  of  solubility  of  the  guano  in  water  as  a 
good  criterion  of  its  quality ;  but  this  is  a  most  fallacious  test.  Sound  guano  contains 
from  15  to  25  per  cent,  of  insoluble  urate  of  ammonia;  nearly  as  much  undefined  animal 
matter,  along  with  from  15  to  20  of  earthy  phosphates,  leaving  no  more  than  50  or  55  per 
cent  of  soluble  matter,  exclusive  of  moisture ;  whereas  decayed  guano  yields  often  60  or 
70  per  cent  of  its  weight  to  water,  in  consequence  of  the  uric  acid  and  animal  matter 
being  wasted  away,  and  the  large  portion  of  moisture  in  it,  the  latter  amounting  very 
often  to  from  25  to  35  per  cent  The  good  Peruvian  guano  does  not  lose  more  than  from 
7  to  9  per  cent,  by  drying,  even  at  a  heat  of  212°  Fahr. ;  and  this  loss  necessarily  includes 
a  little  ammonia.  Each  analysis  of  guano  executed  for  the  information  of  the  farmer 
should  exliibit  definitely  and  accurately  to  at  least  1  per  cent: — 

1.  The  proportion  of  actual  ammonia. 

2.  The  proportion  of  ammonia  producible  also  from  the  uric  acid  and  azotized 
animal  matter  present ;  and  which  may  be  called  the  potential  ammonia.  This  is  a 
most  valuable  product,  which  is,  however,  to  be  obtained  only  from  well-preserved  drt 
guano. 

3.  The  proportion  of  uric  acid,  to  which,  if  1  10th  of  the  weight  be  added,  the  quan- 
tity of  urate  of  ammonia  is  given. 

4.  The  proportion  of  the  phosphates  of  lime  and  magnesia. 

5.  The  proportion  of  fixed  alkaline  salts,  distinguishing  the  potash  from  the  soda 
salts ;  the  former  being  more  valuable,  and  less  readily  obtainable,  than  the  latter  can 
be  '  y  the  use  of  common  salt.  Wheat,  peas,  rye,  and  potatoes,  require  for  their  success- 
ful cultivation,  a  soil  containing  alkaline  salts,  especially  those  of  potash. 

6.  The  proportion  of  sandy  or  other  earthy  matter,  which,  in  genuine  guano  care- 
fully collected,  never  exceeds  2  per  cent,  and  that  is  silica.  ' 

7.  The  proportion  of  water,  separable  by  the  heat  of  212=^  F. 

The  farmer  should  never  purchase  guano  except  its  composition  in  the  preceding 
particulars  be  warranted  by  the  analysis  of  a  competent  chemist.  He  should  cork  up 
m  a  bottle  a  half-pound  sample  of  each  kind  of  guano  that  he  buys ;  and  if  his  crop 
shall  disappoint  reasonable  expectation,  he  should  cause  the  samples  to  be  analyzed; 
and  should  the  result  not  correspond  to  the  analysis  exhibited  at  the  sale,  he  is  fairly 
entitled  to  damages  for  the  loss  of  his  labor,  rent,  crop,  &c.  The  necessity  of  follow- 
ing this  advice  will  appear  on  considering  the  delusive  if  not  utterly  false  analyses, 
under  which  cargoes  of  guano  have  been  too  often  sold.  In  a  recent  case  which  came 
under  my  cognizance,  in  consequence  of  having  been  employed  professionally  to  analyze 
the  identical  cargo,  I  found  the  guano  to  be  nearly  rotten  and  efiete;  containing  aUo- 
gether  only  2.^  per  cent,  of  ammonia,  |  per  cent,  of  urate  of  ammonia,  nearly  f)  of  sea 
gait,  24  of  water,  and  45|  of  earthy  phosphates.  Now,  this  large  cargo,  of  many 
hundred  tons,  fetched  a  high  price  at  a  public  sale,  under  the  exhibition  of  the  follow- 
ing analysis  by  a  chemist  of  some  note : — 


962 


GUAJNO. 

Urate  of  ammonia,  ammoniacal  salts,  and  decayed  animal  matter  17'4 

Phosphate  of  lime,  phosphate  of  magnesia,  and  oxalate  of  lime  -  48- 1 

Fixed  alkaline  salts  -------_.  jo-g 

Earthy  and  stony  matter   --------  1.4 

Moisture           -------...  22*3 


100-0 


The  purchasers,  I  was  told  by  the  broker,  bought  it  readily  under  a  conviction  that 
the  guano  contained  17*4  of  ammonia,  though  the  proportion  of  ammonia  is  not  stated, 
bat  merely  mystified,  and  adroitly  confounded  with  the  decayed  animal  matter. 

By  the  following  hypothetical  analysis,  much  guano  has  been  well  sold  : — 

"  Bone  earth,  35  ;  lithic  acid,  &c.,  15  ;  carbonate  of  ammonia,  14 ;  organic  matter,  36 
=  100."  I  am  quite  certain  that  no  sample  of  guano  can  contain  14  per  cent,  of  carbonate 
of  ammonia— a  very  volatile  salt.  We  sWl  see  presently  the  state  of  combination  in 
which  the  ammonia  exists.  It  may  contain  at  the  utmost  4  or  5  per  cent,  of  the  carbo- 
nate ;  but  such  guano  must  have  been  acted  upon  powerfully  by  humidity,  and  will 
therefore  contain  little  or  no  uric  acid. 

In  the  very  elaborate  examination  of  guano  by  T.  Oellacher,  apothecary  at  Inns- 
bruck, published  in  a  recent  number  of  Buchner's  Repcrtorium  of  Pharmacy ,  it  is  said, 
that  if  a  glass  rod  dipped  into  muriatic  acid  be  held  over  guano,  strong  fumes  are  de- 
veloped; and  the  solution  of  guano  has  an  alkaline  reaction  with  litmus-paper.  These 
phenomena  evidently  indicate  the  presence  of  carbonate  of  ammonia,  and  of  course  a 
partially  decomposed  guano ;  for  sound  Chincha  and  Bolivian  guanos  have  an  acid  re- 
action, proceeding  from  the  predominance  of  phosphoric  acid.  Farmers  frequently 
judge  of  the  goodness  of  guano  by  the  strength  of  the  ammoniacal  odor ;  but  in  this 
judgment  they  may  egregiously  err,  for  the  soundest  guano  has  no  smell  of  ammonia 
whatever ;  and  it  begins  to  give  out  that  smell  only  when  it  is  more  or  less  decomposed 
and  wasted. 

Oellacher  could  find  no  evidence  of  urea  in  his  guano ;  I  have  obtained  fully  5  per 
cent,  of  this  substance  from  good  Peruvian  guano. 

I  shall  now  describe  my  own  system  of  analysis  : — 

1.  In  every  case  I  determine,  first  of  all,  the  specific  gravity  of  the  guano ;  which  I 
lake  by  means  of  spirits  of  turpentine,  with  a  peculiar  instrument  contrived  to  render 
the  process  easy  and  precise.  If  it  exceeds  1*75  in  density,  water  being  1*0,  it  must 
contain  sandy  impurities,  or  has  an  excess  of  earthy  phosphates,  and  a  defect  of  azotized 
animal  matter. 

2.  I  triturate  and  digest  200  grains  of  it  with  distilled  water,  filter,  dry  the  insoluble 
matter,  and  weigh  it. 

3.  The  above  solution,  diffused  in  2,000  gr.  measures,  is  examined  as  to  its  specific 
gravity,  and  then  with  test  paper,  to  see  whether  it  be  acid  or  alkaline. 

4.  One  naif  of  this  solution  is  distilled  along  with  slaked_  lime  in  a  matrass  connected 
with  a  small  quintuple  globe  condenser,  containing  distilled  water,  and  immersed  in  a 
basin  of  the  same.  As  the  condensing  apparatus  terminates  in  a  water-trap,  no  part 
of  the  ammonia  can  be  lost ;  and  it  is  all  afterward  estimated  by  a  peculiar  meter,  whose 
indicatioi.s  make  manifest  one  hundredth  part  of  a  grain. 

5.  The  other  half  of  the  solution  is  mixed  with  some  nitric  acid,  and  divided  into  3 
equal  portions. 

a,  the  first  portion,  is  treated  with  nitrate  of  barytes,  and  the  resulting  sulphate  ol 
barytes  is  collected,  ignited,  and  weighed. 

6.  the  second  portion,  is  treated  with  nitrate  of  silver,  and  the  resulting  chloride  of 
silver  ignited  and  weighed. 

c,  the  third  portion,  has  a  certain  measure  of  a  definite  solution  of  ferric  nitrate  mixed 
with  it,  and  then  ammonia  in  excess.  From  the  weight  of  the  precipitated  subphosphate 
of  iron  after  ignition,  the  known  amount  of  oxide  used  being  deducted,  the  quantity  of 
phosphoric  acid  in  the  soluble  portion  of  the  guano  becomes  known. 

/i,  the  three  above  portions  are  now  mixed,  freed  by  a  few  drops  of  dilute  sulphuric 
and  hydrochloric  acids  from  any  barytes  and  silver  left  in  them,  and  then  tested  by 
nitrate  of  lime  for  oxalate  of  ammonia.  The  quantity  of  oxalate  of  lime  obtained,  de- 
termines that  point. 

6.  The  last  liquor  filtered,  being  freed  from  any  residuary  particles  of  lime  by  oxalate 
of  ammonia,  is  evaporated  to  dryness  and  ignited,  to  obtain  the  fixed  alkaline  matter. 
This  being  weighed,  is  then  dissolved  in  a  little  water,  neutralized  with  acid,  and  treated 
with  soda-chloride  of  platinum.  From  the  quantity  of  potash-chloride  of  platinum,  which 
precipitates,  after  being  filtered,  dried,  and  weighed,  the  amount  of  potash  present  is 
deducted — the  rest  is  soda.  These  bases  may  be  assigned  to  the  sulphuric,  hydro-chloric, 
and  phosphoric  acids,  in  proportions  corresponding  to  their  respective  affinities. 

7.  The  proportion  of  organic  matter  in  the  above  solution  of  guano,  is  determined 
directly  by  evaporating  a  certain  portion  of  it  to  dryness,  and  igniting.      The  loss  of 


GUANO. 


963 


weight,  minus  the  anmaonia  and  oxalic  acid,  represents  the  amount  of  organic  matter. 

8.  A  second  portion  of  a  solution  of  the  guano  is  evaporated  to  dryness  by  a  gertle 
steam  heat,  weighed,  enclosed  in  a  stout  well-closed  phial  along  with  alcohol  of  0*825, 
and  heated  to  212^.  After  cooling,  the  alcoholic  solution  is  decanted  or  filtered  clear, 
evaporated  to  dryness  by  a  gentle  h  at,  and  weighed.  This  is  urea,  which  may  be  tested 
by  its  conversion  into  carbonate  of  a  imonia,  when  heated  in  a  test  tube  or  small  retort. 
In  this  way,  I  have  obtained  from  Bo.  ivian  guano,  5  per  cent,  of  urea ;  a  certain  proof 
of  its  entire  soundness. 

9.  .Analysis  of  the  insoluble  matter.  One  third  of  it  is  digested  with  heat  in  abundance 
of  Borax-water,  containing  ^i^.  of  the  salt,  filtered,  and  the  filter  dried  by  a  steam  heat. 
The  loss  of  weight  indicates  the  amount  of  uric  acid,  which  is  verified  by  supersaturating 
the  filtrate  with  acetic  or  hydrochloric  acid,  thus  precipitating  the  uric  acid,  throwing  it 
upon  a  filter,  drying,  and  weighing  it.  This  weight  should  nearly  agree  with  the  above 
loss  of  weight,  the  small  difference  being  due  to  soluble  organic  matter,  sometimes  called 
geine  and  ulmic  acid.  The  uric  acid  is  evidenced,  1,  by  its  specific  gravity,  which  1 
find  to  be  only  1'25,  as  also  that  of  the  urate  of  ammonia ;  2,  by  its  aflbrding  fine  purple 
murexide  when  heated  in  a  capsule  along  with  nitric  acid,  and  then  exposed  to  the  vapor 
of  ammonia  from  a  feather  held  over  it ;  3,  by  its  dissipation  when  heated,  without 
emitting  an  empyreumatic  odor. 

10.  Another  third  of  the  solid  matter  is  distilled  along  with  half  its  weight  of  slaked 
lime,  and  10  times  its  weight  of  water,  in  the  apparatus  already  described,  and  the  am- 
monia obtained  from  it  estimated. 

11.  The  remaining  third  having  been  ignited,  is  digested  with  a  gentle  heat  in  weak 
hydrochloric  acid,  and  the  undissolved  silica  and  alumina  washed  on  a  filter,  dried,  and 
weighed.  To  the  hydrochloric  solution,  dilute  sulphuric  acid  is  added,  and  the  mixture 
is  heated  till  all  the  h^'drochloric  acid  be  expelled,  with  the  greater  part  of  the  water. 
Alcohol  of  0'850  is  now  poured  upon  the  pasty  residuum,  and  the  whole,  after  being  well 
stirred,  is  thrown  upon  a  filter.  The  phosphoric  acid  passes  through,  as  also  the  magnesia 
in  union  with  sulphuric  acid.  The  sulphate  of  lime,  which  is  quite  insoluble  in  spirits 
of  wine,  being  washed  with  them,  is  dried,  ignited,  and  weighed.  From  the  weight  of 
sulphate  of  lime,  the  quantity  of  phosphate  of  that  earth,  that  was  present,  becomes 
known. 

12.  Ammonia  in  excess  is  now  added  to  the  filtrate,  which  throws  down  the  granular 
phosphate  of  ammonia  and  magnesia.  After  washing  and  drying  this  powder  at  a  heat 
of  l.^'O'^,  its  weight  denotes  the  quantity  of  that  compound  in  the  guano. 

13.  To  the  filtered  liquor  (of  12),  if  a  little  ammonia  be  added,  and  then  muriate  ol 
magnesia  be  slowly  dropped  in,  phosphate  of  ammonia  and  magnesia  will  precipitate, 
from  the  amount  of  which  the  quantity  of  phosphoric  acid  may  be  estimated. 

14.  The  pvoDortion  of  oxalate  of  lime  is  determined  by  igniting  the  washed  residuuic 
(of  9)  and  placing  it  in  an  apparatus  for  estimating  the  quantity  of  carbonic  acid  given 
off  in  dissolving  carbonate  of  lime.  The  apparatus,  either  fig.  1  or  2,  described  in  my 
littie  Treatise  on  Alkalimetry,  will  serve  that  purpose  well.  I  have  rarely  obtained 
more  than  ^  gr.  of  carbonic  acid  from  the  insoluble  residuum  of  100  gr.  of  good  guano, 
and  that  corresponds  to  less  than  1|  per  cent,  of  oxalate  of  lime  in  the  guano.  Some- 
times no  effervescence  at  all  is  to  be  perceived  in  treating  the  washed  residuum  with 
acid  af^er  ignition. 

15.  The  carbonate  of  ammonia  in  guano  is  readily  determined  by  filtering  the  solution 
of  it  in  cold  water,  and  neutralizing  the  ammonia  with  a  test  or  alkalimelrical  acid. 
(See  the  Treatise  on  Alkalimetry,  above  referred  to.) 

16.  Besides  the  above  series  of  operations,  the  following  researches  must  be  made  to 
complete  our  knowledge  of  guano.  The  insoluble  residuum  (of  10)  which  has  been 
deprived  by  two  successive  operations  of  its  uric  acid  and  ammonia,  may  contain  azo- 
tized organic  matter.  It  is  to  be  therefore  well  dried,  mixed  with  5  times  its  weight  of 
the  usual  mixture  of  hydrate  of  soda  and  quicklime,  and  subjected  to  gentle  ignition  in 
a  glass  or  iron  tube  closed  at  one  end,  and  connected  at  the  other  with  an  ammonia 
condensing  apparatus.  The  amount  of  ammonia  being  estimated  by  a  proper  ammonia 
meter,  represents  the  quantity  of  azote,  allowing  14  of  this  element  for  17  of  ammonia, 
beina:  the  potential  ammonia  corresponding  to  the  undefined  animal  matter.  In  a  sample 
of  Peruvian  guano  I  obtained  5  per  cent,  of  ammonia  from  this  source. 

17.  The  whole  quantity  of  ammonia  producible  from  guano  is  to  be  determined  by 
gently  igniting  25  gr.  of  it  well  dried,  and  mixed  with  ten  times  its  weight  of  the  mix- 
ture of  hydrate  of  soda  and  quicklime  (2  parts  of  the  latter  to  1  of  the  former;.  The 
ammonia  disengaged  is  condensed  and  measured,  as  described  above. 

18.  The  ready-formed  ammonia  is  in  all  cases  determined  by  distilling  a  mixture  ot 
100  gr.  of  it  with  50  gr.  of  slaked  lime,  condensing  the  disengaged  ammonia,  and  esti 
mating  it  exactly  by  the  meter. 

19.  The  relation  of  the  combustible  and  volatile  to  the  incombustible  and  fixed  con- 
stituents of  guano,  is  determined  by  igniting  100  gr.  of  it  in  a  poised  platinum  capsule. 


964 


GUANO. 


The  loss  of  weight  denotes  the  amount  of  combustible  and  volatile  matter,  including 
the  moisture,  which  is  known  from  a  previous  experiment. 

20.  The  insoluble  matter  is  digested  in  hot  water,  thrown  upon  a  filter,  dried,  and 
weighed.  The  loss  of  weight  is  due  to  the  fixed  alkaline  salts,  which,  after  concentra- 
ting their  solutions,  are  investigated  by  appropriate  tests  :  1,  nitrate  of  barytes  for  the 
sulphates;  2,  nitrate  of  silver  for  the  chlorides  and  sulphates;  and  3,  soda-chloride  of 
platinum,  for  distinguishing  the  potash  from  the  soda  salts. 

21.  The  insoluble  matter  (of  20)  is  digested  with  heat  in  dilute  nitric  or  hydro- 
chloric acid,  and  the  whole  thrown  upon  a  filter.  The  silica  which  remains  on  the 
filter  is  washed,  ignited,  and  weighed.  The  lime,  magnesia,  and  phosphoric  acid,  may 
be  determined  as  already  pointed  out. 

22.  I  have  endeavored  to  ascertain  if  muriate  of  ammonia  be  present  in  guano,  by 
evaporating  its  watery  solution  to  dryness,  and  subliming  the  residuum,  but  I  have 
never  obtained  a  satisfactory  portion  of  sal  ammoniac;  and  therefore  I  am  inclined  to 
think  there  is  little  of  it.  The  quantity  of  chlorine  to  be  obtained  from  guano  is  too  in- 
considerable to  lead  to  a  suspicion  of  its  presence,  except  in  combination  with  sodium 
and  potassium.  Phosphate  of  soda  is  also  a  doubtful  product — but  if  present,  it  may  be 
obtained  from  the  saline  matter  (of  20),  by  acidulating  it  with  nitric  acid ;  precipita- 
ting first  with  nitrate  of  barytes,  next  with  nitrate  of  silver,  taking  care  to  use  no  ex- 
cess of  these  two  re-agents,  then  supersaturating  the  residuum  with  ammonia,  and  ad- 
ding acetate  of  magnesia,  when  the  characteristic  double  phosphate  of  this  earth  should 
fall,  in  case  phosphate  of  soda  be  present. 

By  the  preceding  train  of  researches,  all  the  constituents  of  this  complex  product  may 
be  exactly  disentangled  and  estimated  ;  but  they  manifestly  require  much  care,  patience, 
time,  and  dexterity^  and  also  a  delicate  balance,  particularly  in  using  the  appropriate 
apparatus  for  generating  the  potential  ammonia,  and  for  measuring  the  whole  of  this 
volatile  substance  separated  in  the  several  steps  of  the  process.  It  may  be  easily  im- 
agined how  little  confidence  can  be  reposed  in  many  of  the  analyses  of  guano,  framed, 
I  fear,  too  often  with  the  view  of  promoting  the  sale  of  an  indiflferent  or  even  spurious 
article  of  commerce. 

A.  I  shall  now  give  in  detail  my  analytical  results  upon  three  diflferent  samples  of 
a  good  South  American  guano ;  and  next  the  general  results  upon  three  samples  of 
African  and  Chilian  guanos  : — 

1.  Guano  from  Bolivia,  imported  by  the  Mary  and  Anne.  Thb  sample  was  taken 
by  myself,  as  an  average  out  of  several  bags  in  the  lighter,  before  the  cargo  was  landed. 
Pale  yellow  brown  color,  dry,  partly  pulverulent,  partly  concreted,  in  small  lumps, 
with  a  few  small  fragments  of  granite  interspersed,  and  which,  being  obvious,  were 
separated  prior  to  the  analysis.  Specific  gravity  of  the  pulverulent  portion  without 
the  granite,  1  60  ;  of  the  concretions,  1-66;  mean  1'63.  Water  digested  on  the  formef 
portion  is  neutral  to  litmus,  that  on  the  latter  is  faintly  acid. 

2.  100  parts  lose  6-5  by  the  heat  of  boiling  water,  and  exhale  no  ammonia.  When 
digested  and  triturated  with  cold  water,  30'5  parts  dissolve,  and  69-5  are  obtained  after 
dr>'ing,  at  212°  F.  Of  those  30-5  parts,  6-5  are  therefore  water,  easily  separable,  and 
24-5  parts  are  solid  matter. 

3.  100  parts,  mixed  with  9  times  their  weight  of  water,  and  50  of  lime,  being  distilled 
in  an  alembic  connected  with  the  five-globe  condenser,  &c.,  afforded  exactly  4-2  of  am- 
monia. 20  grains  in  fine  powder,  along  with  200  of  a  mLxture,  consisting  of  2  parts  of 
dry  lime  and  1  of  hydrate  of  soda,  were  gently  ignited  in  a  combustion-tube  connected 
with  the  ammonia-condensing  apparatus,  and  they  produced  4-25  grains  of  ammonia-— 
equivalent  to  21-25  from  100  grains  of  the  guano.  Thus  only  4*2  per  cent,  of  ammonia 
were  ready  formed;  while  17*05  lurked,  so  to  speak,  in  their  azotized  elements. 

From  its  aspect,  and  its  want  of  ammoniacal  odor,  this  guano,  the  first  cargo  re- 
ceived from  Bolivia,  was  imagined  by  the  importers  to  be  of  bad  quality ;  and,  accord- 
ingly, my  very  favorable  report  of  its  analysis  surprised  them  not  a  little,  and  rather 
unsettled  the  little  faith  they  at  that  time  (January,  1843)  had  in  chemistry.  But  about 
a  fortnight  after  the  date  of  my  report  they  received  a  letter  from  Peru,  apprizing  them 
of  the  excellence  of  that  cargo  of  Bolivian  guano,  and  of  its  being  prized  by  the  Ameri- 
cans, as  possessing  fertilizing  powers  in  a  pre-eminent  degree.  I  consider  this  guano, 
therefore,  as  a  type  of  the  substance  in  its  best  state. 

II.  The  soluble  matter  was  analyzed,  in  the  manner  already  detailed,  and  was  found 
to  consist  of — 

1.  Urea 

2.  Sulphate  of  potash  -  .  - 

3.  Chloride  of  sodium  -  -  . 

4.  Biphosphate  of  ammonia 

5.  Oxalate  of  anmionia         -  -  - 


GUANO. 


965 


In  these  ammoniacal  salts  there  are  only  1-65  parts  of  ammonia;  but  I  obtained  2-55 
grains  m  distilling  the  soluble  matter  of  100  grains  of  the  guano.  The  remaining  0-9 
parts,  therefore,  must  have  proceeded  from  the  partial  decomposition  of  the  urea  during 
the  long  ebullition  necessary  to  extract  every  particle  of  ammonia,  in  distilling  the 
guano  along  with  lime. 

HI.  The  ivsoluble  matter  =69*5  parts,  was  found  to  consist  of— 


1. 
2. 
3. 
4. 
5. 


Silica     -----...  2'25 

Subphosphate  of  lime                -            -            -            .            .  9*00 

Phosphate  of  magnesia  and  ammonia               -            -            .  i.25 

Urate  of  ammonia         -            .            _            .            _            .  15*27 
Undefined  azotized  organic  matter,  aflfording,  with  the  14  parts 
of  uric  acid,  by  ignition  with  hydrate  of  soda,  17-05  parts 

of  ammonia                --,--_  41'73 


69-50 

This  result  as  to  the  large  proportion  of  organic  matter  in  the  dried  insoluble  residu- 
vm  was  verified  by  igniting  a  given  quantity  of  it,  when  it  was  found  to  lose,  out  of 
69-5  parts,  57 ;  corresponding  to  the  15-27  urate  of  ammonia,  41-73  of  undefined  organic 
matter,  and  0-08  of  ammonia,  in  the  double  magnesian  phosphate.  In  the  urate  and 
double  phosphate  are  1-35  of  ammonia,  which,  with  the  2-55,  make  3-9  parts;  the  other 
0-3  parts  may  be  traced  to  the  urea. 

As  these  results  difl'er  very  considerably  in  many  respects  from  those  of  the  analyses 
Bttade  by  respectable  German  chemists,  1  was  careful  to  verify  them  by  manifold  varia- 
tions of  the  process,  as  follows : —  « 

1.  The  soluble  matter,  with  acid  reaction,  of  100  parts  of  the  lumps  of  the  Bolivian 
guano,  was  examined  by  per-acetate  of  iron  and  ammonia,  for  phosphoric  acid,  and 
afforded  4  parts  of  it,  which  is  more  than  had  been  found  in  the  neutral  pulverulent 
guano.  After  the  phosphoric  acid  was  separated  by  that  method,  chloride  of  calcium 
gave  no  cloud  with  the  filtered  liquor,  proving  that  no  oxalic  acid  was  present  in  these 
nodules.  The  washed  insoluble  matter,  when  gently  ignited,  and  treated  with  dilute 
citric  acid,  aflTorded  no  effervescence  whatever,  and  therefore  showed  that  no  oxalate  of 
lime  had  been  present,  for  it  would  have  become  a  carbonate. 

It  is  necessary  to  determine  from  time  to  time  the  quantity  of  ferric  oxide  in  tne 
acetate  or  nitrate,  as  it  is  liable  to  be  deposited  from  the  solution  when  this  is  kept  for 
some  time.  If  this  point  be  not  attended  to,  serious  errors  would  be  committed  in  the 
estimation  of  the  phosphoric  acid. 

2.  The  quantity  of  uric  acid  was  verified  by  several  repetitions,  and  found  to  be  14 
per  cent. 

3.  The  undefined  organic  matter,  when  deprived  of  the  uric  acid  by  prolonged  diges- 
tion with  weak  borax,  being  subjected  to  ignition  along  with  hydrate  of  soda,  yielded 
the  quantity  of  ammonia  requisite  to  constitute  the  whole  sum,  that  producible  from  the 
uric  acid  also  being  taken  into  account. 

4.  The  little  lumps  of  the  guano  afforded,  by  distillation  along  with  quicklime   5-27 
per  cent,  of  ready-formed  ammonia,  probablv  from  the  uric  acid  havin<'  been  partially 
decomposed  by  the  moisture  which  had  caused  them  to  concrete.     It  is  a  curious  fact 
that  the  solution  of  borax,  from  being  of  an  alkaUne,  becomes  of  an  acid  reaction,  after 
digestion  with  the  Bolivian  guano. 

5.  For  distinguishing  and  separating  the  soda  salts  from  those  of  potash,  I  tried  the 
antimoniate  of  potash,  according  to  Wackenroder's  prescription,  but  I  found  reason  to 
prefer  very  much  the  crystallized  soda-chloride  of  platinum,  for  that  purpo«:e. 

From  another  specimen  of  the  Bolivian  guano,  I  extracted  3-5  per  ct.  of  the  ammonia- 
phosphate  of  magnesia. 

B.  A  sample  of  guano  from  the  Chincha  islands,  of  nearly  the  same  light  color  as 
the  preceding,  and  the  same  dryness,  being  an  early  importation  of  250  tons  in  the 
present  year,  was  subjected  by  me  to  a  careful  analysis. 

1.  The  solution  m  water  of  this  guano  had  an  alkaline  reaction  from  caibonate  of 
amrnonia,  which,  being  neutralized  by  test  acid,  indicated  0-34  per  cent,  of  ammonia, 
eiuivalent  to  about  1  of  the  smelling  sesqui-carbonate. 

2.  Of  this  guano,  47  per  cent,  were  soluble  in  water^  and  53  per  cent,  remained,  after 
drying  at  a  heat  of  212^  F.     Of  the  above  47  parts,  8-5  were  moisture  in  the  guano. 

.i.  The  solution  being  acidulated  with  nitric  acid,  was  treated  with  acetate  of  barytes, 
m  a  quantity  equivalent  to  the  sulphuric  acid  present,  and  it  afforded  12  parts  of  sul- 
phate of  barytes.  With  the  filtered  liquor,  700  water  grain  measures  of  ferric  acetate 
were  mixed,  and  then  ammonia  in  excess ;  18-5  parts  of  washed  and  ignited  sub-phosphate 
of  iron  were  obtained,  from  which  deducting  8-8  parts  present  in  the  acetate,  9-7  re- 
main as  the  quantity  of  phosphoric  acid ;  but  9-7  of  acid  produce  13-25  of  bi-phos- 
phate  of  ammonia,  which  contain  only  2-3  of  ammonia,  combined  with  0-95  of  water. 


966 


GUANO. 


or  its  elements.  From  the  alkaline  excess  in  the  guano,  there  can  be  no  doubt,  how- 
ever, that  it  contained  the  sub-phosphate  {faimd  in  the  urine  of  Carnivora),  and  not  the 
bi-phosphate  of  that  base.  In  this  case,  9-7  of  acid  produce  14-32  of  dry  saline  com- 
pound, containing  4*62  of  ammonia,  which,  with  the  0-34  of  ammonia  in  the  carbonate, 
constitute  a  sum  of  4'96.  To  the  liquor  freed  from  the  phosphate  of  iron,  and  acidu- 
lated with  nitric  acid,  acetate  of  lime  being  added,  3*33  parts  of  oxalate  of  this  base 
were  obtained,  which  are  equivalent  to  3*23  oxalate  ammonia,  containing  0*89  of  am- 
monia. 

4.  Nitrate  of  silver  now  produced  from  the  filtered  residual  solution  8  parts  of  chlo- 
ride, corresponding  to  nearly  3  of  sal  ammoniac,  which  contain  nearly  0*95  of  ammonia. 

5.  The  53  parts  insoluble  in  water  were  digested  with  weak  solution  of  borax  at  a  boil- 
ing heat,  thrown  on  a  filter,  and  the  uric  acid  being  precipitated  from  the  filtrate  by 
means  of  a  little  hydrochloric  acid,  washed  and  dried,  was  found  to  weigh  13-5  parts. 
There  were  left  on  the  filter  36*5  parts,  dried  at  212°  F.,  so  that  3  parts  of  soluble  or- 
ganic matter  had  passed  through  the  filter.  These  36*5  parts  lost  by  ignition  only  9*7 
parts  in  organic  matter,  became  white,  and  afforded  a  very  faint  eflfervescence  with 
hydro-chloric  acid,  showing  that  a  very  little  oxalate  of  lime  had  been  present.  1*23 
parts  of  silica  were  left  after  the  action  of  the  acid.  To  the  solution  of  the  26-55  parts, 
sulphuric  acid  was  added,  and  the  mixture  being  heated  to  expel  the  hydro-chloric  acid 
and  the  excess  of  the  sulphuric,  the  residuary  matter  was  digested  and  washed  with  di- 
lute alcohol,  and  thrown  on  a  filter ;  the  solution  of  magnesia  passed  through,  while  the 
sulphate  of  lime  remained.  After  ignition,  this  weighed  27*5  parts,  equivalent  to  22  of 
sub-phosphate  of  lime.  On  supersaturating  the  filtrate  with  ammonia,  4*5  parts  of  the 
magnesian  ammonia  phosphate  were  precipitated,  containing  0.32  of  ammonia.  With 
the  13»5  parts  of  uric  acid,  1*23  of  ammonia  had  be'en  originally  combined,  forming  14*73 
of  urate. 

6.  25  grains  of  the  dry  guano  afforded,  by  ignition  in  the  combustion-tube  along  with 
200  grains  of  the  mixed  lime  and  hydrate  of  soda,  4*165  of  ammonia,  which  correspond 
to  16*66  in  100  parts  of  the  dry,  or  to  15*244  in  the  natural  state;  leaving  therefore  5 
parts  for  the  quantity  of  potential  ammonia,  or  of  ammonia  producible  from  the  de 
composition  of  its  azotized  organic  matter.  This  guano  is,  therefore,  well  adapted  to 
promote  permanently  the  fertility  of  a  soil.  It  yields  besides  to  alcohol  a  notable 
quantity  of  urea,  which  I  did  not  think  it  worth  while  to  determine  quantitivelv,  and 
from  which  undoubtedly  a  portion  of  the  ammonia  proceeded,  in  the  distillation  vitL 
milk  of  lime. 

7.  100  parts  afforded  by  distillation  with  milk  of  lime,  10*2  of  ammonia. 

8.  The  total  constituents  of  that  guano,  being  tabulated,  are — 

1.     Matter  soluble  in  water  -  -  -  47*00 

consisting  of — 

1.  Sulphate  of  potash,  with  a  little  sulphate  of  soda 

2.  Muriate  of  ammonia  ... 

3.  Phosphate  of  ammonia 

4.  Sesqui-carbonate  of  ammonia 

5.  Sulphate  of  ammonia  -  -  - 

6.  Oxalate  of  ammonia  -  -  - 

7.  Water  .  .  .  .  . 
S.  Soluble  organic  matter  and  urea 


II.     Matter  insoluble  in  water 


consisting  of — 


1.  Silica  .  .  .  . 

2.  Undefined  organic  matter 

3.  Urate  of  ammonia      -  -  - 

4.  Oxalate  of  lime  -  _  . 

5.  Sub-phosphate  of  lime 

6.  Phosphate  of  magnesia  and  ammonia 


The  remaining  1.25  of  actual  ammonia  may  be  fairly  traced  to  the  partial  decomposi 
tion  of  the  urea  during  the  distillation  with  lime ;  whereas  the  5  per  cent,  of  potential 
ammonia  proceeded  from  the  transforming  decomposition  of  the  uric  acid. 

C.  Foliated  guanOy  from  Peru,  in  caked  pieces,  the  layers  very  thin,  parallel,  and  in- 
terspersed with  white  streaks.  This  guano  was  somewhat  dense  for  a  pure  specimen, 
having  a  specific  gravity  of  1*7.    The  insoluble  matter  afforded  by  digestion  with  borax 


—  — 

Ammonia 

6*00 

3*00 

0.95 

14-32 

4*62 

1-00 

0*34 

2*00 

0-50 

3*23 

0*89 

8*50 

8*95 

47-00 

53*00 

1-25 

9*52 

14*73 

1-23 

1*00? 

22*00 

4*50 

0*32 

53*00 

9*80 

GUANO. 


967 


water,  no  less  than  25*2  perct.  of  pale  yellow  uric  acid;  9  of  other  combustible  organic 
matter,  and  15  of  earthy  matter;  consisting  of  silica,  3*5;  phosphate  of  magnesia  and 
ammonia,  6-5 ;  and  only  5  of  sub-phosphate  of  lime  or  bone  earth.  It  lost  10  per  cent, 
when  dried  in  a  heat  of  212°  F.  The  remaining  30*8  parts  soluble  in  water,  had  a 
strong  acid  reaction,  and  afforded,  by  ferric  acetate  and  ammonia,  6  of  phosphoric  acid, 
equivalent  to  9*7  of  crystallized  bi-phosphale  of  ammonia,  after  acetate  of  barytes  had 
separated  the  sulphuric  acid.  No  less  than  17  parts  of  chloride  of  silver  were  obtained, 
by  precipitating  with  nitrate  of  silver  the  liquor  filtered  from  the  phosphate  of  iron,  and 
acidulated  with  nitric  acid.  As  the  present  is  an  accidental  sample,  and  not  an  average 
of  any  importation,  I  did  not  prosecute  the  research  further. 

I).  Chincha  guano,  of  a  somewhat  darker  color  than  the  preceding,  and  alkaline  re- 
action ;  specific  gravitj',  1*62.  Digested  with  water  and  strained,  56*75  parts  remained 
after  drying  it  at  212°  F.  The  solution,  evaporated  and  dried  also  at  212°,  afforded 
31*25  of  saline  matter.  This  saline  mass  being  mixed  with  four  fifths  of  its  weight  of 
slaked  lime,  nine  times  its  weight  of  water,  and  distilled,  aflforded  of  ammonia  14*28 
per  cent.  Some  chemists  have  prescribed  potash  instead  of  lime,  for  separating  the  am- 
monia in  distillation ;  but  no  person  of  intelligence  who  has  made  the  experiment  once 
will  choose  to  repeat  it,  because  the  potash  forms  with  the  organic  matter  of  the  guano 
a  viscid  compound,  that  froths  up  like  a  mass  of  soap-bubbles,  and  coming  over  with 
the  vapors,  obstructs  and  vitiates  the  result. 

2.  When  dried  altogether  by  a  steam  heat,  100  parts  lost  12  in  moisture ;  whereas  by 
evaporating  and  drying  the  soluble  matter  by  itself,  the  loss  amounted  to  16*3,  no 
doubt  by  the  dissipation  of  some  of  the  ammoniacal  salts ;  for  100  parts  of  the  entire 
guano  aflbrd,  by  distillation  with  quicklime,  9  parts  of  ammonia,  and  bv  the  trans- 
forming decomposition  with  hydrate  of  soda  and  lime,  16*25,  indicating  7*25  of  potential 
ammonia,  in  addition  to  the  9  of  ready  formed.  The  insoluble  matter  of  100  parts 
afforded  to  borax-water  a  solution  containing  16*5  of  uric  acid,  corresponding  to  18  of 
urate  of  ammonia.  There  remained  on  the  filter,  after  dr^'ing  it  at  212°  F.,  only  33*8 
parts;  so  that  about  5  parts  of  soluble  organic  matter  had  passed  through  the  filter  io 
the  borax  water.  These  33*8  consisted  of  subphosphate  of  lime  17,  magnes;an  phos- 
phate of  ammonia  5*5,  silica  0*7,  and  combustible  organic  matter  10*6. 

The  ammonia  in  the  soluble  portion  was  in  the  state  chiefly  of  phosphate;  there  was 
merely  a  faint  trace  of  oxalate  of  ammonia. 

E.  African  Guam).— Among  the  many  samples  of  African  guano  which  I  have  had 
occasion  to  analyze  for  the  importers,  none  has  contained  any  appreciable  quantity 
of  uric  acid,  or  by  consequence  of  potential  ammonia.  The  best  aflforded  me  10  per 
cent,  of  ready-formed  ammonia,  existing  chiefly  in  the  state  of  a  phosphate,  though  they 
all  contain  carbonate  of  ammonia,  and  have  of  consequence  an  alkaline  reaction.  The 
said  sample  contained  21*5  of  moisture,  separable  by  a  heat  of  212°  F.  Its  specific 
gravity  was  so  low  as  1*57,  in  consequence  of  the  large  proportion  of  moisture  in  it. 
It  contained  23  per  cent,  of  subphosphate  of  lime,  3  of  magnesian  phosphate  of  am- 
monia, 1  of  silica,  and  1*5  of  alkaline  sulphate  and  muriate.  The  remaining  50  parts 
consisted  of  decayed  organic  matter,  with  phosphate  of  ammonia,  and  a  little  carbonate, 
equivalent  to  half  a  grain  of  ammonia,  which  is  the  largest  quantity  in  such  guanos. 
Other  African  guanos  have  aflx)rded  from  24  to  36  of  moisture,  no  uric  acid ;  no  po^ 
tential  ammonia;  but  decayed  organic  matter;  from  5  to  7  of  ready-formed  ammonia  in 
the  state  of  phosphate,  with  a  little  carbonate;  from  25  to  35  per  cent,  of  subphosphate 
of  lime ;  5  or  6  of  the  magnesian  phosphate  of  ammonia ;  more  or  less  oxalates  from 
the  decomposition  of  the  uric  acid,  and  3  to  5  per  cent,  of  fixed  alkaline  salts. 

F.  The  Chilian  Guam  gathered  on  the  coasi,  already  adverted  to,  contained  a  remarka- 
ble proportion  of  common  salt,  derived  probably  from  the  sea  spray. 

The  following  is  the  general  report  of  the  chemical  examination  of  several 
samples  of  guano,  which  I  made  for  Messrs.  Gibbs  of  London,  and  Messrs.  Myers  of 
Liverpool : — 

"  In  these  various  analyses,  performed  with  the  greatest  care,  and  with  the  aid  of  the 
most  complete  apparatus  for  both  inorganic  and  organic  analysis,  my  attention  has  been 
directed,  not  only  to  the  constituents  of  the  guano  which  act  as  an  immediate  manure, 
but  to  those  which  are  admitted  by  practical  farmers  to  impart  durable  fertility  to  the 
grounds.  The  admirable  researches  of  Professor  Liebig  have  demonstrated  that  Azote, 
the  indispensable  element  of  the  nourishment  of  plants,  and  especially  of  wheat  and 
others  abounding  in  gluten  (an  azotized  product),  must  be  presented  to  them  in  the  state 
of  ammonia,  yet  not  altogether  ammonia  in  the  pure  or  saline  form,  for,  as  such,  it  is 
too  readdy  evaporated  or  washed  away ;  but  in  the  dormant,  or  as  one  may  say,  in  the 
potential  condition  in  contradistinction  from  the  actual.  Genuine  Peruvian  and  Bolivian 
guanos,  like  those  which  I  have  minutely  analyzed,  surpass  very  far  all  other  species 
of  manure,  whether  natural  or  artificial,  in  the  quantity  of  potential  ammonia,  and, 
therefore,  m  the  permanency  of  their  action  upon  the  roots  of  plants,  while,  in  conse 
quence  of  the  ample   store  of  actual  ammonia  which  they  contain  ready  formed,  they 


968 


GUANO. 


GUMS. 


i 

s 

3 
3 


ore  qualified  to  give  immediate  visror  to  vearetation.  Urate  of  airmonia  constitutes  a 
considerable  portion  of  the  azotized  organic  matter  in  well-pr( served  guano;  it  is 
nearly  insoluble  in  water,  not  at  all  volatile,  and  is  capable  of  yielding  to  the  soil,  by 
its  slow  decomposition,  nearly  one  third  of  its  weight  of  ammonia.  No  other  manure 
can  rival  this  animal  saline  compound.  One  of  the  said  samples  cf  guano  afforded  me 
no  less  than  17  per  cent,  of  potential  ammonia,  besides  4^  per  cent,  of  the  actual  or 
ready  formed ;  others  from  7  to  8  per  cent,  of  ammonia  in  each  of  these  states  re- 
spectively. These  guanos  which  I  have  examined  are  the  mere  excrement  of  birds, 
and  are  quite  free  from  the  sand,  earth,  clay,  and  common  salt,  reported  in  the  analyses 
of  some  guanos,  and  one  of  which  (sand)  to  the  amount  of  30  per  cent.  I  found  myself 
n  a  sample  of  guano  from  Chile. 

"  The  Peruvian  guano,  moreover,  contains  from  10  to  25  per  cent,  of  phosphate  of 
lime,  the  same  substance  as  bone-earth,  but  elaborated  by  the  birds  into  a  pulpy  con- 
sistence, which,  while  it  continues  insoluble  in  water,  has  been  thereby  rendered  more 
readily^  absorbable  and  digestible  (so  to  speak)  by  the  roots  of  ilants.  I  have  there- 
fore no  doubt,  that  by  the  judicious  application  of  these  genuine  guanos,  mixed  with 
twice  or  thrice  their  weight  of  a  marly  or  calcareous  soil,  to  convert  their  phosphate  of 
ammonia  into  phosphate  of  lime  and  carbonate  of  ammonia,  as  also  to  dilute  all  their 
ainmoniacal  compounds — such  crops  will  be  produced,  even  un  sterile  lands,  as  the 
farmer  has  never  raised  upon  the  most  improved  soil  by  the  best  crdinary  manure.  To 
the  West  India  planter,  guano  will  prove  the  greatest  boon,  sir  ce  it  condenses  in  a 
portable  and  inoffensive  shape  the  means  of  restoring  fertility  to  his  exhausted  cane- 
fields,  a  benefit  it  has  long  conferred  on  the  poorest  districts  of  Peru. 

**  I  respectfully  observe,  that  no  analysis  of  guano  hitherto  u  ade  public  at  all  ex- 
habits  the  value  of  tne  cargoes  referred  to  above,  while  none  gives  the  quantity  of 
ammonia  dormant  in  the  azotized  animal  matter  of  the  birds'  dung,  which,  called  into 
activity  with  the  seeds  in  the  soil,  becomes  the  most  valuable  of  its  constituents,  as  a 
source  of  perennial  fertility.  In  the  detailed  account  of  my  anrlyses  of  this  complex 
excretion  (now  preparing  for  publication),  all  the  above  statements  will  be  bioughl 
within  the  scope  of  general  comprehension.  I  shall  also  describe  my  '  ammonia  gene- 
rator,' based  on  the  process  invented  in  the  laboratory  of  Professor  Lii**big,  and  also  my 
*  ammonia  metei ,' which,  together,  can  detect  and  measure  one  hundredth  part  of  a 
grain  weight  of  absolute  ammonia,  whether  potential  or  actual,  in  any  sample  of 
guano. 

"  Meanwhile  the  following  may  be  oflered  as  the  average  result  of  my  analyses  of 
genuine  guano  in  reference  to  its  agricultural  value  : — 

*'  1.  Azotized  animal  matter,  including  urate  of  ammonia,  to- 
gether capable  of  afiording  from  8  to  16  per  cent,  of 
ammonia  by  slow  decomposition  in  the  soil  -  -  50 

2.  Water 8  to  11 

3.  Phosphate  of  lime      -  -  -  -  -       12  to  25 

4.  Phosphate  of  ammonia,  sulphate  of  ammonia,  ammonia- 

phosphate  of  magnesia,  together  containing  from  6  to 

9  parts  of  ammonia  -  -  -  •  -  13 

5.  Siliceous  sand  -  -  -  -  •  -     1 

100 

"  Very  moist  guano  has  in  general  more  actual  and  less  potential  ammonia  than  the 
d:y  guano. 

"Andrew  Ure. 
**  Londony  13  Charlotte  street,  Bedford  square, 
"  February  14,  1843." 

Oellacher's  analysis  of  a  brownish  yellow  guano  is  as  follows  [see  top  of  next 
page]  :— 

I  am  satisfied  from  its  large  proportion  of  oxalate  of  ammonia,  that  the  sample  Xhr% 
analyzea  was  by  no  means  a  fair  or  normal  specimen  of  guano  ;  and  it  is  in  fact  widely 
different  from  all  the  fresh  samples  which  have  passed  through  my  hands.  It  is 
described  as  "  knobby,  being  mixed  with  light  laminated  crystalline  portions,  in  white 
grains,  from  the  size  of  a  pea  to  that  of  a  pigeon's  e^^."  Having  some  lumpy  concre 
tions  of  a  similar  aspect  in  my  possession,  I  submitted  them  to  chemical  examination. 

G.  1,000  grains  being  digested  in  boiling  water  and  strained,  afforded  a  nearly  color- 
less solution.  This  was  concentrated  till  crystals  of  oxalate  of  ammonia  appeared.  It 
was  then  acidulated  with  hydrochloric  acid,  to  protect  the  phosphoric  acid  from  pre- 
cipitation, and  next  treated  carefully  with  a  solution  of  nitrate  of  lime  equivalent  to  the 
oxalic  acid  present.  The  oxalate  of  lime  thus  obtained  being  converted  into  carbonate 
weighed  80-5  grains,  corresponding  to  100  of  oxalate  of  ammonia,  being  10  per  cent, 
of  the  weight  of  the  guano. 


1.  Urate  of  ammonia 

2.  Oxalate  of  ammonia 

3.  Oxalate  of  lime        -  -  - 

4.  Phosphate  of  ammonia 

5.  Phosphate  of  ammonia  and  magnesia 

6.  Phosphate  of  lime     -  -  - 

7.  Muriate  of  ammonia 

8.  Chloride  of  sodium  (common  salt)   - 

9.  Carbonate  of  ammonia 

10.  Carbonate  of  lime 

11.  Sulphate  of  potash 

12.  Sulphate  of  soda 

13.  Humate  of  ammonia 

14.  Substance  resembling  wax  - 

15.  Sand  .  _  .  - 

16.  Water  (hygroscopic) 

17.  Undefined  organic  matter   - 


Ammonia. 

.  12-20 

1-06 

-  17-73 

6-50 

-     1-30 

-    6-90 

1-79 

-  11-63 

1-68 

-  20-16 

-    2-25 

0-72 

-    0-40 

-    0-80 

0-23 

-     1-65 

-    4-00 

-    4-92 

-     1-06 

009 

.    0-75 

■     1-68 

.     4-31 

8-26 

100-00 


12-07 


The  liquor  filtered  from  the  oxalate  was  precipitated  by  nitrate  of  barytes,  and 
afforded  112  grains  of  sulphate  of  barytes  =  38  sulphuric  acid;  and  the  last  filtrate 
being  mixed  with  a  given  measure  of  ferric  acetate,  and  the  mixture  supersaturated 
with  ammonia,  yielded  subphosphate  of  iron,  equivalent  to  5  per  cent  of  phosphoric 
acid.  I  digested  with  heat  other  500  grains  of  the  same  guano  in  a  weak  solution  of 
borax,  filtered,  acidulated  the  liquid,  but  obtained  merely  a  trace  of  uric  acid.  It  i* 
clear  thereft-TC  that  the  oxalate  of  ammonia  had  been  formed  in  this  guano  at  the 
expense  of  the  uric  acid,  and  that  its  concreted  state,  and  the  crystalline  nodules  dis- 
seminated through  it,  were  the  result  of  transformation  by  moisture  in  a  hot  climate, 
which  had  agglomerated  it  to  a  density  of  1-73 ;  whereas  clean  fresh  guano,  friable  and 
dry  like  the  above,  is  seldom  denser  than  1-65.  The  guano  contained  only  3-23  of 
ar-jmonia ;  65  of  insoluble  matter,  53  of  earthy  phosphates,  5  silica,  3  alkaline  salts 
(.fixed),  and  7  organic  matter. 

Oxalate  of  ammonia,  being  readily  washed  away,  it  is  a  bad  substitute  for  the  urate 
of  ammonia,  urea,  and  azotized  animal  matter,  which  it  has  replaced.  Oellacher 
eouid  find  no  urea  in  the  guano  which  he  analyzed ;  another  proof  of  its  dis- 
integration. 

Rartel's  analysis  of  a  brown-red  guano  is  as  follows : — 

1.  Muriate  of  ammonia        -        -  -        -        -        -       6-500 

2.  Oxalate  of  ammonia        -        -  ...        -     13-351 

3.  Urate  of  ammonia   --------      3*244 

4.  Phosphate  of  ammonia    -------       6-450 

5.  Substances  resembling  wax  and  resin       -        -        -        -       ^-600 

6.  Sulphate  of  potash  _.-----       4-277 

7.  Sulphate  of  soda     -        -        -        -        -        -        -        -1*119 

8.  Phosphate  of  soda 5*291 

9.  Phosphate  of  lime 9-940 

10.  Phosphate  of  ammonia  and  magnesia  -        _        -       4-196 

11.  Common  salt  --.---..       0-100 

12.  Oxalate  of  lime 16-360 

13.  Alumina  ---------      0*104 

14.  Sand  insoluble  in  nitric  acid,  and  iron      -         -         .        -       5-800 

15.  Loss  (water  and  volatile  ammonia  and  undefined  organic 

matter) 22*718 


100-000 
Voelckel,  in  his  analysis  of  guano,  states  7  per  cent,  of  oxalate  of  lime— a  result  quite 
at  variance  with  all  my  experience — for  I  have  never  found  so  much  as  2  per  cent,  of 
carbonate  of  lime  in  the  washed  and  gently  ignited  insoluble  mutter  ;  whereas,  accoi-ding 
to  Bartels  and  Voelckel,  from  10  to  5  per  cent,  of  carbonate  should  be  obtained,  as  the 
equivalents  of  the  proportions  of  the  oxalate  assigned  by  them. 

All  these  analyses  are  defective  moreover  in  not  showing  the  total  quantity  of  ammonia 
which  the  guano  is  capable  of  giving  out  in  the  soil ;  and  since  it  appears  that  the  freshest 
guano  abounds  most  in  what  I  have  called  potential  ammonia,  it  must  Dossess  of  con- 
sequence, the  greatest  fertilizing  virtue. 


f 


970 


GUM  RENINS. 


GUNPOWDER. 


971 


4 


sent 


A  sample  of  decayed  darh-hro^m  moist  guano  from  Chile,  being  examined  an  above 
described,  for  oxalate  of  ammonia,  was  found  to  contain  none  whatever  ;  and  it  contained 
less  than  1  per  cent,  of  uric  acid. 

H.  An  article  offered  to  the  public,  by  advertisement,  as  Peruvian  guano,  was  lately 
nt  to  me  for  analysis.     I  found  it  to  bo  a  spurious  composition ;  it  consisted  of — 

1.  Common  salt       -  -  .  .  - 

2.  Common  siliceous  sand     .... 
Sulphate  of  iron  or  copperas 
Phosphate  of  lime  .... 
Organic  matter  from  bad  guano,  «fcc  (to  give  it  smell) 
Moisture                           -  .  .  . 


3. 
4. 
6. 
6. 


320 
280 

5-2 

40,  with 
23-3 

7-6 


1000 


Genuine  guano,  wlien  burned  upon  a  red  hot  shovel,  leaves  a  white  ash  of  phos' 
phate  of  lime  and  magnesia ;  whereas  this  factitious  substance  left  a  black  fused  mass 
of  sea  salt,  copperas,  and  sand.  Tlie  specific  gravity  of  good  fresh  guano  is  seldom  more 
than  1-66,  water  being  100;  whereas  that  of  the  said  substance  was  so  high  as  2-17, 
produced  by  the  salt,  sand,  and  copperas. 

GUM  {Gomme,  Fr. ;  Gummi,  Pflamenschhim,  Germ.)  is  the  name  of  a  proximate 
vegetable  product,  which  forms  with  water  a  slimy  solution,  but  is  insoluble  in  alcohol, 
ether,  and  oils ;  it  is  converted  by  strong  sulphuric  acid  into  oxalic  and  mucic  acids. 

There  are  six  varieties  of  gum  :  1.  gum  arabic ;  2.  gum  Senegal ;  3  gum  of  the  cherry 
and  other  stone  fruit  trees  :  4.  gum  tragacanth;  5.  gum  of  Bassora ;  6.  the  gum  of  seeds 
and  roots.  The  first  five  spontaneously  flow  from  the  branches  and  trunks  of  their  trees, 
and  sometimes  from  the  fruits,  in  the  form  of  a  mucilage  which  dries  and  hardens  in  the 
air.     The  sixth  kind  is  extracted  by  boiling  water. 

Gum  arabic  and  gum  Senegal  consist  almost  wholly  of  the  purest  gum  ^.alled  arabine  by 
the  French  chemists;  our  native  fruit  trees  contain  some  c«rasj«e,  along  with  ars bine ; 
the  gum  of  Bassora  and  gum  tragacanth  consist  of  arabine  and  bassorine. 

Chim  arabic  flows  from  the  acacia  arabica,  and  the  acacia  veruj  which  grow  upon  the 
banks  of  the  Nile  and  in  Arabia.  It  occurs  in  commerce  in  the  form  of  small  pieces, 
rounded  upon  one  side  and  hollow  upon  the  other.  It  is  transparent,  without  smell, 
brittle,  easy  to  pulverize,  sometimes  colorless,  sometimes  with  a  yelk  -/  or  brownish 
tint.  It  may  be  bleached  by  exposure  to  the  air  and  the  sun-beams,  at  the  temperature 
of  boiling  water.  Its  specific  gravity  is  1-355.  Moistened  gum  arabic  reddens  litmus 
paper,  owing  to  the  presence  of  a  little  supermalate  of  lime,  which  may  be  removed  by 
boiling  alcohol ;  it  shows  also  traces  of  the  chlorides  of  potassium  and  calcium,  and  the 
acetate  of  potash.  100  parts  of  good  gum  contain  70*40  of  arabine,  17-60  of  water, 
with  a  few  per  cents,  of  saline  and  earthy  matters.  Gum  arabic  is  used  in  medicine,  as 
also  to  give  lustre  to  crapes  and  other  silk  stuifs. 

Gum  Senegal  is  collected  by  the  negroes  during  the  month  of  November,  from  the 
acacia  Senegal,  a  tree  18  or  20  feet  high.  It  comes  to  us  in  pieces  about  the  size  of  a 
partridge  egg,  but  sometimes  larger,  with  a  hollow  centre.  Its  specific  gravity  is  1*436. 
It  consists  of  81*10  arabine;  16*10  water;  and  from  2  to  3  of  saline  matters.  The 
chemical  properties  and  uses  of  this  gum  are  the  same  as  those  of  gum  arabic.  It  is 
much  employed  in  calico-printing. 

Cherry-tree  gum  consists  of  52*10  arabine;  54*90  cerasine ;  12  water;  and  1  saline 
matter. 

Gum  tragacanth  is  gathered  about  the  end  of  June,  from  the  astragalus  tragacaniha 
of  Crete  and  the  surrounding  islands.  It  has  the  appearance  of  twisted  ribands ;  is  while 
or  reddish ;  nearly  opaque,  and  a  little  ductile.  It  is  difllicult  to  pulverize,  without  heat- 
ing the  mortar.  Its  specific  gravity  is  1*384.  When  plunged  in  water,  it  dissolves  m 
part,  swells  considerably,  and  forms  a  very  thick  mucilage.  100  parts  of  it  consist  of 
53*30  arabine;  3330  bassorine  and  starch;  110  water;  and  from  2  to  3  parts  of  saline 
matters.     It  is  employed  in  calico  printing,  and  by  shoemakers. 

Gum  of  Bassora  ;  see  Bassorine. 

Gum  of  seeds,  as  linseed,  consists  of  52*70  arabine  ;  28*9  of  an  insoluble  matter  ;  10-3 
water;  and  7*11  saline  matter.  Neither  bassorine  nor  cerasine  seems  to  be  present  in 
seeds  and  roots.     For  British  Gum,  see  Starch. 

GUM  RESINS.  {Gomme-resines,  Fr.;  Schleimharzey  Germ.)  When  incisions  are 
made  in  the  stems,  branches,  and  roots  of  certain  plants,  a  milky  juice  exudes,  which 
gradually  hardens  in  the  air ;  and  appears  to  be  formed  of  resin  and  essential  oil,  held 
suspended  in  water  charged  with  gum,  and  sometimes  with  other  vegetable  matters, 
such  as  caoutchouc,  bassorine,  starch,  wax,  and  several  saline  matters.  Tie  said  con- 
crete juice  is  called  a  gum-resin  ;  an  improper  name,  as  it  gives  a  false  idea  of  the  nature 
of  the  substance.    They  are  all  solid  ;  heavier  than  water ;  in  general  opaque  and  brittle ; 


many  have  an  acrid  taste,  and  a  strong  smell ;  their  colour  is  very  variable.  They  are 
partiallv  soluble  in  water,  and  also  in  alcohol ;  and  the  solution  in  the  former  liquid 
seldom  becomes  transparent.  Almost  all  the  gum  resins  are  medicinal  substances,  and 
little  employed  in  the  arts  and  majiufactures.  The  following  is  a  list  of  them  :  assa- 
fcetida  ;  gum  anunoniac  ;  bdellium ;  euphorbium  ;  galbanum  ;  gamboge  ;  myrrh  ;  oliba- 
num  or  frankincense ;  opoponax ;  and  scammony.  Some  of  these  are  described  in  this 
work  under  their  peculiar  names. 

GUMS.  Under  the  generic  name  Gum  several  substances  have  been  classed,  which 
differ  essentially,  though  they  possess  the  following  properties  in  common ;  viz.  form- 
ing a  thick  mucilaginous  liquid  with  water,  and  being  precipitable  from  that  solution 
by  alcohol.  Properly  speaking,  we  should  style  gums  only  such  substances  as  are  trans- 
formed into  mucic  acid  by  nitric  acid;  of  which  bodies  there  are  three:  I.  Arabine, 
which  constitutes  almost  the  whole  of  gum  arabic ;  2.  Bassorine,  which  forms  the  chief 
part  of  gum  tragacanth ;  and  3.  Cerasine,  which  occurs  in  cheny-tree  gum,  and  ia  con- 
vertible into  gum  arabic  by  hot  water, 

1.  Gum  arabic,  in  its  ordinary  state,  contains  17  per  cent,  of  water,  separable  from  it 
by  a  heat  of  212°  Fahr. 

2.  Chorry-tree  gum  consists  of  52  per  cent  of  arabine,  and  35  of  a  peculiar  gum, 
which  has  been  called  Cerasine.  Tliis  latter  substance  is  convertible  into  grape  sugar 
oy  boiling  it  with  very  dilute  sulphuric  acid. 

GUNPOWDER.  The  following  memoir  upon  this  subject  was  published  by  me  in 
the  Journal  of  the  Royal  Institution  for  October,  1830.  It  contains  the  results  of 
several  careful  analytical  experiments,  as  also  of  observations  made  at  the  Roval 
Gunpowder  Works  at  Wallham  Abbey,  and  at  some  similar  establishments  in  the 
neighbourhood  of  London. 

Gunpowder  is  a  mechanical  combination  of  nitre,  sulphur,  and  charcoal ;  deriving 
the  intensity  of  its  explosiveness  from  the  purity  of  its  constituents,  the  proportion  in 
which  they  are  mixed,  and  the  intimacy  of  the  admixture. 

1.  On  the  nitre, — Nitre  may  be  readily  purified,  by  solution  in  water  and  crystalliza- 
tion, from  the  muddy  particles  and  foreign  salts  with  which  it  is  usually  contammated. 
In  a  saturated  aqueous  solution  of  nitre,  boiling  hot,  the  temperature  is  240°  F. ;  and 
the  relation  of  the  salt  to  its  solvent  is  in  weight  as  three  to  one,  by  my  experiments :  not 
five  to  one,  as  MM.  Bottee  and  Riffault  have  stated.  We  must  not,  however,  adopt  the 
general  language  of  chemists,  and  say  that  three  parts  of  nitre  are  soluble  in  one  of  boil- 
ing water,  since  the  liquid  has  a  much  higher  heat  and  greater  solvent  power  than  this 
expression  implies. 

Water  at  60*»  dissolves  only  one  fourth  of  its  weight  of  nitre;  or,  more  exactly,  this 
saturated  solution  contains  21  per  cent,  of  salt.  Its  specific  gravity  is  1*1415;  100  parte 
in  volume  of  the  two  constituents  occupy  now  97*91  parts.  From  these  data  we  may 
perceive  that  little  advantage  could  be  gained  in  refining  crude  nitre,  by  making  a  boiling- 
hot  saturated  solution  of  it;  since  on  cooling,  the  whole  would  concrete  into  a  moist 
saline  mass,  consisting  by  weight  of  2f  parts  of  salt,  mixed  with  1  part  of  water,  holding 
\  of  salt  in  solution,  and  in  bulk  of  1|  of  salt,  with  about  1  of  li(juid  ;  for  the  specific 
gravity  of  nitre  is  2*005,  or  very  nearly  the  double  of  water.  It  is  better,  therefore,  to 
use  equal  weights  of  saltpetre  and  water  in  making  the  boiling-hot  solution.  When  the 
filtered  liquid  is  allowed  to  cool  slowly,  somewhat  less  than  thii^e  fourths  of  the  nitre  will 
separate  in  regular  crystals ;  while  the  foreign  salts  that  were  present  will  remain  with 
fully  one  fourth  of  nitre  in  the  mother  liquor.  On  redissolving  these  crystals  with  heat, 
in  about  two  thirds  of  their  weight  of  water,  a  solution  will  result,  from  which  crystalline 
nitre,  fit  for  every  purpose,  will  concrete  on  cooling. 

As  the  principal  saline  impurity  of  saltpetre  is  muriate  of  soda  (a  substance  scarcely 
more  soluble  in  hot  than  in  cold  water),  a  ready  mode  thence  arises  of  separating  that 
salt  from  the  nitre  in  mother  waters  that  contain  them  in  nearly  equal  proportion. 
Place  an  iron  ladle  or  basin,  perforated  with  small  holes,  on  the  bottom  of  the  bailer  in 
which  the  solution  is  concentrating.  The  muriate,  as  it  separates  by  the  evaporation  of 
the  water,  will  fall  down  and  fill  the  basin,  and  may  be  removed  from  time  to  time. 
When  small  needles  of  nitre  begin  to  appear,  the  solution  must  be  run  ofl"  into  the  crys- 
tallizing cooler,  in  which  moderately  pure  nitre  will  be  obtained,  to  be  refined  by  another 
similar  operation. 

At  the  Waltham  Abbey  gunpowder  works  the  nitre  is  rendered  so  pure  by  successive 
solutions  and  crystallizations,  that  it  causes  no  opalescence  in  a  solution  of  nitrate  of 
silver.  Such  crystals  are  dried,  fused  in  an  iron  pot  at  a  temperature  of  from  500°  to 
600**  F.,  and  cast  into  moulds.    The  cakes  are  preserved  in  casks. 

About  the  period  of  1794  and  1795,  under  the  pressure  of  the  first  wars  of  their 
revolution,  the  French  chemists  employed  by  the  government  contrived  an  expeditious, 
economical,  and  sufficiently  effective  mode  of  purifying  their  nitre.  It  must  be  observed 
that  this  salt,  as  brought  to  the  gun  powder- works  in  France,  is  in  general  a  much  cruder 


972 


GUNPOWDER. 


GUNPOWDER. 


973 


11 
Ji 


article  than  that  imported  into  this  country  from  India.  It  is  extracted  from  the 
nttrous  salts  contained  in  the  mortar-rubbish  of  old  buildings,  especially  those  of  the 
lowest  and  filthiest  descriptions.  By  their  former  methods,  the  French  could  not  refine 
their  nitre  in  less  lime  than  eight  or  ten  days;  and  the  salt  was  obtained  in  great  lumps, 
very  difficult  to  dry  and  divide  ;  whereas  the  new  process  was  so  easy  and  so  quick,  that 
in  less  than  twenty-four  hours,  at  one  period  of  pressure,  the  crude  saltpetre  was  con- 
verted into  a  pure  salt,  brought  to  perfect  dryness,  and  in  such  a  state  of  extreme  division 
as  to  supersede  the  operations  of  grinding  and  sifting,  whence  also  considerable  waste 
was  avoided. 

The  following  is  a  brief  outline  of  this  method,  with  certain  improvements,  as  now 
practised  in  the  establishment  of  the  Administration  des  poudres  et  saltpetres^  in  France. 
The  refining  boiler  is  charged  over  night  with  600  kiloarammes  of  water,  afld  120C 
kilosrammes  of  saltpetre,  as  delivered  by  the  salpetriers.  No  more  fire  is  applied  than 
is  adequate  to  effect  the  solution  of  this  first  charge  of  saltpetre.  It  may  here  be  observed, 
that  such  an  article  contains  several  deliquescent  salts,  and  is  much  more  soluble  than 
pupa  nitre.  On  the  morrow  morning  the  fire  is  increased,  and  the  boiler  is  charged  at 
different  intervals  with  fresh  doses  of  saltpetre,  till  the  whole  amounts  to  3000  kilo- 
grammes. During  these  additions,  care  is  taken  to  stir  the  liquid  very  diligently,  and  to 
skim  off  the  froth  as  it  rises.  When  it  has  been  for  some  time  in  ebullilion,  and  when  it 
may  be  presumed  that  the  solution  of  the  nitrous  salts  is  effected,  the  muriate  of  soda  is 
scooped  out  from  the  bottom  of  the  boiler,  and  certain  affusions  or  inspersions  of  cold 
water  are  made  into  the  pot,  to  quicken  the  precipitation  of  that  portion  which  the  boiling 
motion  may  have  kept  afloat.  When  no  more  is  found  to  fall,  one  kilogramme  of  Flanders 
plue,  dissolved  in  a  sufficient  quantity  of  hot  water,  is  poured  into  the  boiler;  the  mix- 
lure  is  thoroughly  worked  together,  the  froth  being  skimmed  ofi",  with  several  successive 
inspersions  of  cold  water,  till  400  additional  kilogrammes  have  been  introduced,  const!- 
tutmg  altogether  1000  kilogrammes. 

When  the  refining  liquor  affords  no  more  froth,  and  is  grown  perfectly  clear,  all  manip. 
ulation  must  cease.  The  fire  is  withdrawn,  with  the  exception  of  a  mere  kindhng,  so  as 
to  maintain  the  temperature  till  the  next  morning  at  about  88°  C.  =  190-4  F. 

This  liquor  is  now  transferred  by  hand-basins  into  the  crystallizing  reservoirs,  taking 
care  to  disturb  the  solution  as  little  as  possible,  and  to  leave  untouched  the  impure 
matter  at  the  bottom.  The  contents  of  the  long  crystallizing  cisterns  are  stirred  back- 
wards and  forwards  with  wooden  paddles,  in  order  to  quicken  the  cooling,  and  the 
consequent  precipitation  of  the  nitre  in  minute  crystals.  These  are  raked,  as  soon  as  they 
fall,  to  the  upper  end  of  the  doubly-inclined  bottom  of  the  crystallizer,  and  thence  re- 
moved to  the  washing  chests  or  boxes.  By  the  incessant  agitation  of  the  liquor,  no  large 
crystals  of  nitre  can  possibly  form.  When  the  tem.porature  has  fallen  to  within  7°  or  8* 
F.,  of  the  apartment,  that  is,  after  seven  or  eight  hours,  all  the  saltpetre  that  it  can  yield 
will  have  been  obtained.  By  means  of  the  double  inward  slope  given  to  the  crystallizer, 
the  supernatant  liquid  is  collected  in  the  middle  of  the  breadth,  and  may  be  easily  laded 

The  saltpetre  is  shovelled  out  of  the  crystallizer  into  the  washing  chests,  and  heaped 
up  in  them  so  as  to  stand  about  six  or  seven  inches  above  their  upper  edges,  in  order  to 
allow  for  the  subsidence  which  it  must  experience  in  the  washing  process.  Each  of  these 
chests  being  thus  filled,  and  their  bottom  holes  being  closed  with  plugs,  the  salt  is  be- 
sprinkled from  the  rose  of  a  watering-can,  with  successive  quantities  of  water  saturated 
with  saltpetre,  and  also  with  pure  water,  till  the  liquor,  when  allowed  to  run  off,  indicates 
by  the  hydrometer,  a  saturated  solution.  The  water  of  each  sprinkling  ought  to  remain 
on  the  salt  for  two  or  three  hours;  and  then  it  may  be  suffered  to  drain  off  through  the 
plug-holes  below,  for  about  an  hour. 

AH  the  liquor  of  drainage  from  the  first  watering,  as  well  as  a  portion  of  the  second, 
is  set  aside,  as  being  considerably  loaded  with  the  foreign  salts  of  the  nitre,  in  order  to 
be  evaporated  in  the  sequel  with  the  mother  waters.  The  last  portions  are  preserved, 
because  they  contain  almost  nothing  but  nitre,  and  may  therefore  serve  to  wash  another 
dose  of  that  salt.  It  has  been  proved  by  experience,  that  the  quantity  of  water  employed 
in  washing  need  never  exceed  thirty-six  sprinklings  in  the  whole,  composed  of  three 
waterings,  of  which  the  first  two  consist  of  fifteen,  and  the  last  of  six  pots  =  3  gallons  E.; 
or  in  other  words,  of  fifteen  sprinklings  of  water  saturated  with  saltpetre,  and  twenty- 
one  of  pure  water.  . 

The  saltpetre,  after  remaining  five  or  six  days  in  the  washing  chests,  is  transported  into 
the  drying  reservoirs,  heated  by  the  flue  of  the  nearest  boiler;  here  it  is  stirred  up  from 
time  to  time  with  wooden  shovels,  to  prevent  its  adhering  to  the  bottom,  or  running  into 
lumps,  as  well  as  to  quicken  the  drying  process.  In  the  course  of  about  four  hours,  it 
gets  completely  dry,  in  which  state  it  no  longer  sticks  to  the  shovel,  but  falls  down  into  a 
soft  powder  by  pressure  in  the  handj  and  is  perfectly  white  and  pulverulent.      It  is  now 


passed  through  a  brass  sieve,  to  separate  any  small  lamps  or  foreign  particles  accidentally 
present,  and  is  then  packed  up  in  bags  or  barrels.  Even  in  the  shortest  winter  days,  the 
drying  basin  may  be  twice  charged,  so  as  to  dry  700  or  800  kilogrammes.  By  this  ope- 
ration, the  nett  produce  of  3000  kilogrammes  (3  tons)  thus  refined,  amounts  to  from 
1750  to  1800  kilogrammes  of  very  pure  nitre,  quite  ready  for  the  manufacture  of  gun- 
powder. 

The  mother  waters  are  next  concentrated ;  but  into  their  management  it  is  needless  to 
enter  in  this  memoir. 

On  reviewing  the  above  process  as  practised  at  present,  it  is  obvious  that,  to  meet  the 
revolutionary  crisis,  its  conductors  must  have  shortened  it  greatly,  and  have  been  content 
with  a  brief  period  of  drainage. 

2.  On  the  sulphur. — The  sulphur  now  imported  into  this  country,  from  the  volcanic 
districts  of  Sicily  and  Italy,  for  our  manufactories  of  sulphuric  acid,  is  much  purer  than 
the  sulphur  obtained  by  artificial  heat  from  any  varieties  of  pyrites,  and  may,  therefore, 
by  simple  processes,  be  rendered  a  fit  constituent  of  the  best  gunpowder.  As  it  is  not 
my  purpose  here  to  repeat  what  may  be  found  in  common  chemical  compilations,  I  shall 
say  nothing  of  the  sublimation  of  sulphur ;  a  process,  moreover,  much  too  wasteful  for 
the  gunpowder-maker. 

Sulphur  may  be  most  easily  analyzed,  even  by  the  manufacturer  himself ;  for  I  find  it 
to  be  soluble  in  one  tenth  of  its  weight  of  boiling  oil  of  turpentine,  at  316°  Fahrenheit, 
forming  a  solution  which  remains  clear  at  180**.  As  it  cools  to  the  atmospheric  tempera- 
ture, beautiful  crystalline  needles  form,  which  may  be  washed  sufficiently  with  cold  alco- 
hol, or  even  tepid  water.  The  usual  impurities  of  the  sulphur,  which  are  carbonate  and 
sulphate  of  zinc,  oxyde  and  sulphuret  of  iron,  sulphuret  of  arsenic  and  silica,  will  remain 
unaffected  by  the  volatile  oil,  and  may  be  separately  eliminated  by  the  curious,  though 
•uch  separaticn  is  of  little  practical  importance. 

Two  modes  of  refining  sulphur  for  the  gunpowder  works  have  been  employed ;  the 
first  is  by  fusion,  the  second  by  distillation.  Since  the  combustible  solid  becomes  as 
limpid  as  water,  at  the  temperature  of  about  230°  Fahrenheit,  a  ready  mode  offers  of 
removing  at  once  its  denser  and  lighter  impurities,  by  subsidence  and  skimming.  But 
I  may  take  the  liberty  of  observing,  that  the  French  melting  pot,  as  described  in  the 
elaborate  work  of  MM.  Bottee  and  Ritfault,  is  singularly  ill-contrived,  for  the  fire  is 
kindled  right  under  it,  and  plays  on  its  bottom.  Now  a  pot  for  subsidence  ought  to  be 
cold  set ;  that  is,  should  have  its  bottom  part  imbedded  in  clay  or  mortar  for  four  or  six 
inches  up  the  side,  and  be  exposed  to  the  circulating  flame  of  the  fire  only  round  its 
middle  zone.  This  arrangement  is  adopted  in  many  of  our  great  chemical  works,  and 
is  found  to  be  very  advantageous.  With  such  a  boiler,  judiciously  heated,  I  believe 
that  crude  sulphur  might  be  made  remarkably  pure;  whereas  by  directing  the  beat 
against  the  bottom  of  the  vessel,  the  crudities  are  tossed  up,  and  incorporated  with  the 
mass.     See  Evaporation. 

The  sulphur  of  commerce  occurs  in  three  prevailing  colors;  lemon  yellow  verging  on 
green,  dark  yellow,  and  brown  yellow.  As  these  different  shades  result  from  the  differ- 
ent degrees  of  heat  to  which  it  has  been  exposed  in  its  original  extraction  on  the  great 
scale,  we  may  thereby  judge  to  what  point  it  may  still  be  heated  anew  in  the  refinery 
melting.  Whatever  be  the  actual  shade  of  the  crude  article,  the  art  of  the  refiner  con- 
sists in  regulating  the  heat,  so  that  after  the  operation  it  may  possess  a  brixiant  yellow 
hue,  inclining  somewhat  to  green. 

In  seeking  to  accomplish  this  purpose,  the  sulphur  should  first  be  sorted  according  to 
its  shades ;  and  if  a  greenish  variety  is  to  be  purified,  since  this  kind  has  been  but  little 
heated  in  its  extraction,  the  fusion  may  be  urged  pretty  smartly,  or  the  fire  may  be  kept 
up  till  everything  is  melted  but  the  uppermost  layer. 

Sulphur  of  a  strong  yellow  tinge  cannot  bear  so  great  a  heat,  and  therefore  the  fire 
must  be  withdrawn  whenever  three  fourths  of  the  whole  mass  have  been  melted. 

Brown-colored  brimstone,  having  been  already  somewhat  scorched,  should  be  heated 
as  little  as  possible,  and  the  fire  may  be  removed  as  soon  as  one  half  of  the  mass  is 
fused. 

Instead  of  melting,  separately,  sulphurs  of  different  shades,  we  shall  obtain  a  better  re- 
sult by  first  filling  up  the  pot  to  half  its  capacity,  with  the  greenish-colored  article,  putting 
over  this  layer  one  quarter  volume  of  the  deep  yellow,  and  filling  it  to  the  brim  with 
the  brown-colored.  The  fire  must  be  extinguished  as  soon  as  the  yellow  is  fused.  The 
pot  must  then  be  closely  covered  for  some  time ;  after  which  the  lighter  impurities  will  be 
found  on  the  surface  in  a  black  froth,  which  is  skimmed  off,  and  the  heavier  ones  sink 
to  the  br'tom.  The  sulphur  itself  must  be  left  in  the  pot  for  ten  or  twelve  hours,  after 
which  it  is  laded  out  into  the  crystallizing  boxes  or  casks. 

Distillation  affords  a  more  complete  and  very  economical  means  of  purifying  sulphur, 
which  was  first  introduced  into  the  French  gunpowder  establishments,  when  their 
importation  of  the  best  Italian  and  Sicilian  sulphur  was  obstructed  by  the  British 
navy.    Here  the  sulphur  need  not  come  over  slowly  in  a  rare  va^r,  and  be  deposited 


974 


GUNPOWDER. 


in  a  pulverulent  form  called  flowers ;  for  the  only  object  of  the  refiner  is  to  bring  over 
the  whole  of  the  pure  sulphur  into  his  condensing  chamber,  and  to  leave  all  its  crudities 
in  the  body  of  the  stiJl.  Hence  a  strong  fire  is  applied  to  elevate  a  denser  mass  of 
vapors,  of  a  yellowish  color,  which  passing  over  into  the  condenser,  are  deposited  in 
a  liquid  state  on  its  bottom,  whilst  only  a  few  lighter  particles  attach  themselves  to  the 
upper  and  lateral  surfaces.  The  refiner  must  therefore  give  to  the  heat  in  this  opera- 
tion very  considerable  intensity ;  and,  at  some  height  above  the  edge  of  the  boiler,  he 
should  provide  an  inclined  plane,  which  may  let  the  first  ebullition  of  the  sulphur  over- 
flow into  a  safety  recipient.  The  condensing  chamber  should  be  hot  enough  to  main- 
tain the  distilled  sulphur  in  a  fluid  state— an  object  most  readily  procured  by  leading 
the  pipes  of  several  distilling  pots  into  it ;  while  the  continuity  of  the  operations  is  se- 
cured, by  chaining  each  of  the  stills  alternately,  or  in  succession.  The  heat  of  the  re- 
ceiver must  be  never  so  high  as  to  bring  the  sulphur  to  a  sirupy  consistence,  whereby  its 
color  is  darkened. 

In  the  sublimation  of  sulphur,  a  pot  containing  about  4  cwts.  can  be  worked  off  only 
once  in  twenty-four  hours,  from  the  requisite  moderation  of  its  temperature,  and  the  pre- 
raution  of  an  inclined  plane,  which  restores  to  it  the  accidental  ebullitions.  But,  by  dis- 
tillation, a  pot  containing  fully  ten  cwts.  may  complete  one  process  in  nine  hours  at  most, 
with  a  very  considerable  saving  of  fuel.  In  the  former  plan  of  procedure,  an  interval 
must  elapse  between  the  successive  charges ;  but  in  the  latter,  the  operation  must  be 
continuous  to  prevent  the  apparatus  from  getting  cooled ;  in  sublimation,  moreover,  where 
communication  of  atmospheric  air  to  the  condensing  chamber  is  indispensable,  explosive 
combustions  of  the  sulphurous  vapors  frequently  occur,  with  a  copious  production  of  sul- 
phurous acid,  and  correspondent  waste  of  the  sulphur  j  disadvantages  from  which  the  dis- 
tillatory process  is  in  a  great  measure  exempt. 

I  shall  here  describe  briefly  the  form  and  dimensions  of  the  distilling  apparatus 
employed  at  Marseilles  in  purifying  sulphur  for  the  national  gunpowder  works,  which 
was  found  adequate  to  supply  the  wants  of  Napoleon's  great  empire.  This  apparatus 
consists  of  only  two  still-pots  of  cast  iron,  formed  like  the  large  end  of  an  egg,  each 
about  three  feet  in  diameter,  two  feet  deep,  and  nearly  half  an  inch  thick  at  the  bottom, 
but  much  thinner  above,  with  a  horizontal  ledge  four  inches  broad.  A  pot  of  good 
cast  iron  is  capable  of  distilling  1000  tons  of  sulphur  before  it  is  rendered  unseryiceable, 
by  the  actiun  of  the  brimstone  on  its  substance,  aided  by  a  strong  red  heat.  The  pot  is 
covered  in  with  a  sloping  roof  of  masonry,  the  upper  end  of  which  abuts  on  the  brickwork 
of  the  vaulted  dome  of  condensation.  A  large  door  is  formed  in  the  masonry  in  front 
of  the  mouth  of  the  pot,  through  which  it  is  charged  and  cleared  out ;  and  between  the 
roof-space  over  the  pot,  and  the  cavity  of  the  vault,  a  large  passage  is  opened.  At  the 
back  of  the  pot  a  stone  step  is  raised  to  prevent  the  sulphur  boiling  over  into  the  con- 
denser. The  vault  is  about  ten  feet  wide  within,  and  fourteen  feet  from  the  bottom  up  to 
the  middle  of  the  dome,  which  is  perforated,  and  carries  a  chimney  about  twelve  feet  high, 
and  twelve  feet  diameter  inside. 

As  the  dome  is  exposed  to  the  expansive  force  of  a  strong  heat,  and  to  a  very  con- 
siderable pressure  of  gases  and  vapors,  it  must  possess  great  solidity,  and  be  theiefore 
bound  with  iron  straps.  Between  the  still  and  the  contiguous  wall  of  the  condensing 
chamber,  a  space  must  be  left  for  the  circulation  of  air ;  a  precaution  found  by  experience 
indispensable;  for  the  contact  of  the  furnaces  would  produce  on  the  wall  of  the  chamber 
such  a  heat  as  to  make  it  crack  and  form  crevices  for  the  liquid  sulphur  to  escape. 
The  sides  of  the  chamber  are  constructed  of  solid  masonry,  forty  inches  thick,  sur- 
mounted by  a  brick  dome,  covered  with  a  layer  of  stones.  The  floor  is  paved  with 
tiles,  and  the  wails  are  lined  with  them  up  to  the  springing  of  the  dome ;  a  square 
hole  being  left  in  one  side,  furnished  with  a  strong  iron  door,  at  which  the  liquid 
sulphur  is  drawn  off"  at  proper  intervals.  In  the  roof  of  the  vault  are  two  valve-holes 
covered  with  light  plates  of  sheet-iron,  which  turn  freely  on  hinges  at  one  end,  so  as 
to  give  way  readily  to  any  sudden  expansion  from  within,  and  thus  prevent  dangerous 
explosions. 

As  the  chamber  of  condensation  is  an  oblong  square,  terminating  upwards  in  an  oblong 
vault,  it  consists  of  a  parallelopiped  below,  and  semi-cylinder  above,  having  the  follow- 
ing dimensions : — 


Length  of  the  parallelopiped 
Width  .... 

Height         .        .        .        • 
Radius  of  the  cylinder        .        . 

Height  or  length  of  semi-cylinder 


16|  feet. 
16| 


Whenever  the  workman  has  introduced  into  each  pot  its  charge  of  ten  or  twelve  hun- 
dred weight  of  crude  sulphur,  he  closes  the  charging  doors  carefully  with  their  iron  plates 
and  cross-bars,  and  lutes  them  tight  with  loam.    He  then  kindles  his  fire,  and  makes  the 


GUNPOWDER. 


975 


sulphur  boil.  One  of  his  first  duties  (and  the  least  neglect  in  its  discharge  may  occasion 
serious  accidents)  is  to  inspect  the  roof-valves  and  to  clean  them,  so  that  they  may  play 
freely  and  give  way  to  any  expulsive  force  from  within.  By  means  of  a  cord  and  chain, 
connected  with  a  crank  attached  to  the  valves,  he  can,  from  time  to  time,  ascertain  their 
state,  without  mounting  on  the  roof.  It  is  found  proper  to  work  one  of  the  pots  a  certain 
time  before  fire  is  applied  to  the  other.  The  more  steadily  vapors  of  sulphur  are  seen  to 
issue  from  the  valves,  the  less  atmospherical  air  can  exist  in  the  chamber,  and  therefore 
the  less  danger  there  is  of  combustion.  But  if  the  air  be  cold,  with  a  sharp  north  wind, 
and  if  no  vapors  be  escaping,  the  operator  should  stand  on  his  guard,  for  in  such  circum- 
stances a  serious  explosion  may  ensue.  • 

As  soon  as  both  the  boilers  are  in  full  work  the  air  is  expelled,  the  fumes  cease,  and 
every  hazard  is  at  an  end.  He  should  bend  his  whole  attention  to  the  cutting  ofl*  all  com- 
munication with  the  atmosphere,  securing  simply  the  mobility  of  the  valves,  and  a  steady 
vigor  of  distillation.  The  conclusion  of  the  process  is  ascertained  by  introducing  his 
sounding-rod  into  the  pot,  through  a  small  orifice  made  for  its  passage  in  the  wall.  A 
new  charge  must  then  be  given. 

By  the  above  process,  well  conducted,  sulphurs  are  brought  to  the  most  perfect  stat4, 
of  purity  that  the  arts  can  require ;  while  not  above  four  parts  in  the  hundred  of  the  sul- 
phur itself  are  consumed ;  the  crude,  incombustible  residuum  varying  from  five  to  eight 
parts,  according  to  the  nature  of  the  raw  material.  But  in  the  sublimation  of  sulphur,  the 
frequent  combustions  inseparable  from  this  operation  carry  the  loss  of  weight  in  flowers  to 
about  twenty  per  cent.     See  Sulphur,  for  a  figure  of  the  subliming  apparatus. 

The  process  by  fusion,  performed  at  some  of  the  public  works  in  this  country,  does 
not  afibrd  a  return  at  all  comparable  with  that  of  the  above  French  process,  though  a 
much  better  article  is  operated  upon  in  England.  After  two  meltings  of  rough  sul- 
fAur  (as  imported  from  Sicily  or  Italy),  eighty-four  per  cent,  is  the  maximum  amount 
obtained,  the  average  being  probably  under  eighty  ;  while  the  product  is  certainly  inferior 
in  quality  to  that  by  distillation. 

3.  On  tfie  charcoal. — ^Tender  and  light  woods,  capable  of  afibrding  a  friable  and  porous  • 
charcoal,  which  burns  rapidly  away,  leaving  the  smallest  residuum  of  ashes,  and  con- 
taining therefore  the  largest  proportion  of  carbon,  ought  to  be  preferred  for  charring  in 
gunpowder  works. 

After  many  trials  made  long  ago,  black  dogwood  came  to  be  preferred  to  every  plant 
for  this  purpose ;  but  modern  experiments  have  proved  that  many  other  woods  afford  an 
equally  suitable  charcoal.  The  woods  of  black  alder,  poplar,  lime-tree,  horse-chestnut, 
and  chestnut-tree,  were  carbonized  in  exactly  similar  circumstances,  and  a  similar  gun- 
powder was  made  with  each,  which  was  proved  by  the  same  proof-mortar.  The  follow- 
ing results  were  obtained :— 


Poplar — mean  range 
Black  alder   - 
Lime 

Horse-chestuut 
Chestnut-tree 

•    1   1    1    1 
i    1   1    1    1 

Toisea. 

f  66v« 

113 
.10 
lU 
110 
109 

2 
4 
3 
3 

By  subsequent  experiments,  confirmatory  of  the  above,  it  has  been  further  found  that 
the  willow  presents  the  same  advantages  as  the  poplar,  and  that  several  shrubs,  such  as 
the  hazel-nut,  the  spindle-treee,  the  dogberry,  the  elder-tree,  the  common  sallow,  and 
some  others,  may  be  as  advantageously  employed.  But  whichever  wood  be  used,  we 
should  always  cut  it  when  full  of  sap,  and  never  after  it  is  dead ;  we  should  choose 
branches  not  more  than  five  or  six  years  old,  and  strip  them  carefully,  because  the  old 
branches  and  the  bark  contain  a  larger  proportion  of  earthy  constituents.  The  branches 
ought  not  to  exceed  three  quarters  of  an  inch  in  thickness,  and  the  larger  ones  should  be 
divided  lengthwise  into  four,  so  that  their  pith  may  be  readily  burned  away. 

Wood  is  commonly  carbonized  in  this  country  into  gunpowder-charcoal  in  cast-iron 
cylinders,  with  their  axes  laid  horizontally,  and  built  in  brick-work,  so  that  the  flame  of 
a  furnace  may  circulate  round  them.  One  end  of  the  cylinder  is  furnished  with  a  door, 
for  the  introduction  of  the  wood  and  the  removal  of  the  charcoal ;  the  other  end  termi- 
nates in  a  pipe,  connected  with  a  worm-tub  for  condensing  the  pyroligneous  acid,  and  giv- 
ing vent  to  the  carbureted  hydrogen  gases  that  are  disengaged.  Towards  the  end  of  the 
operation,  the  connexion  of  the  cylinder  with  the  pyroligneous  acid  cistern  ought  to  be 
cut  off,  and  a  very  free  egress  opened  for  the  volatile  matter,  otherwise  the  charcoal  is 
apt  to  get  coated  with  a  fuliginous  varnish,  and  to  be  even  penetrated  with  condensable 
matter,  which  materially  injure  its  qualities. 


I 


. 


976 


GUNPOWDER. 


In  France,  the  wood  is  carbonized  for  the  JTunpowder  works  either  in  oblong  vaulted 
ovens,  or  in  pits,  lined  with  brick-work  or  cylinders  of  strong  sheet-iron.  In  either  case, 
the  heat  is  derived  from  the  imperfect  combustion  of  the  wood  itself  to  be  charred.  In 
general,  the  product  in  charcoal  by  the  latter  method  is  from  16  to  17  parts,  by  weight, 
from  100  of  wood.  The  pit-process  is  supposed  to  afford  a  more  productive  return,  and 
a  better  article ;  since  the  body  of  wood  is  much  greater,  and  the  fuliginous  vapors  are 
allowed  a  freer  escape.  The  surface  of  a  good  charcoal  should  be  smooth,  but  not  glist. 
ening.    See  Charcoal. 

The  charcoal  is  considered  by  the  scientific  manufacturers  to  be  the  ingredient  most 
influential,  by  its  fluctuating  qualities,  upon  the  composition  of  gunpowder;  and, 
therefore,  it  ought  always  to  be  prepared  under  the  vigilant  and  skilful  eye  of  the 
director  of  the  powder  establishment.  If  it  has  been  kept  for  some  time,  or  quenched 
at  first  with  water,  it  is  unsuitable  for  the  present  purpose.  Charcoal  extinguished  in  a 
close  vessel  by  exclusion  of  air,  and  afterwards  exposed  to  the  atmosphere,  absorbs  only 
from  three  to  four  per  cent,  of  moisture,  while  red-hot  charcoal  quenched  with  water  may 
lose  by  drying  twenty-nine  per  cent.  When  the  latter  sort  of  charcoal  is  used  for  gun- 
powder, a  deduction  of  weight  must  be  made  for  the  water  present.  But  charcoal  which 
has  remained  long  impregnated  with  moisture,  constitutes  a  most  detrimental  ingredient 
of  gunpowder. 

4.  On  mixing  the  Constitiunts  and  forming  the  Powder. 

The  three  ingredients  thus  prepared  are  ready  for  manufacturing  into  gunpowder. 
They  are,  1.  Separately  ground  to  a  fine  powder,  which  is  passed  through  sorted  silk 
sieves  or  bolting  machines.  2.  They  are  nfixed  together  in  the  proper  proportions, 
which  we  shall  afterwards  discuss.  3.  The  composition  is  then  sent  to  the  gunpowder 
mill,  which  consists  of  two  edge-stones  of  a  calcareous  kind,  turning  by  means  of  a  hori- 
zontal shaft,  on  a  bed-stone  of  the  same  nature  ;  incapable  of  affording  sparks  by  col- 
lision with  steel,  as  sand-stones  would  do.  On  this  bed-stone  the  composition  is  spread, 
and  moistened  with  as  small  a  quantity  of  water  as  will,  in  conjunction  with  the  weight 
of  the  revolving  stones,  bring  it  into  a  proper  body  of  cake,  but  by  no  means  into  a  pasty 
state.  The  line  of  contact  of  the  rolling  edge-stone  is  constantly  preceded  by  a  hard 
copper  scraper,  which  goes  round  with  the  wheel,  regularly  collecting  the  caking  mass, 
and  bringing  it  into  the  track  of  the  stone.  From  50  to  60  pounds  of  cake  are  usually 
worked  at  one  operation,  under  each  millstone.  When  the  mass  has  been  thoroughly 
kneaded  and  incorporated,  it  is  sent  to  the  corning-house,  where  a  separate  mill  is  em- 
ployed to  form  the  cake  into  grains  or  corns.  Here  it  is  first  pressed  into  a  hard  firm 
mass,  then  broken  into  small  lumps ;  after  which  the  corning  process  is  performed,  by 
placing  these  lumps  in  sieves,  on  each  of  which  is  laid  a  disc  or  fiat  cake  of  lignum  vitae. 
The  sieves  are  made  of  parchment  skins,  or  of  copper,  perforated  with  a  multitude  of 
round  holes.  Several  such  sieves  are  fixed  in  a  frame,  Avhich,  by  proper  machinery,  has 
such  a  motion  given  to  it  as  to  make  the  lignum  vitse  runner  in  each  sieve  move  about 
with  considerable  velocity,  so  as  to  break  down  the  lumps  of  the  cake^  and  fojxt  its  sub- 
stance through  the  holes,  in  grains  of  certain  sizes.  These  granular 'particles  are  after- 
wards separated  from  the  finer  dust  by  proper  sieves  and  reels. 

The  corned  powder  must  now  be  hardened,  and  its  rougher  angles  removed,  by  causing 
it  to  revolve  in  a  close  reel  or  cask  turning  rapidly  round  its  axis.  This  vessel  resemi  les 
somewhat  a  barrel-chum,  and  is  frequently  furnished  inside  with  square  bars  parallel  to 
its  axis,  to  aid  the  polish  by  attrition. 

The  gunpowder  is  finally  dried,  which  is  now  done  generally  with  a  steam  heat,  or  in 
some  places  by  transmitting  a  current  of  air,  previously  heated  in  another  chamber,  over 
canvass  shelves,  covered  with  the  damp  grains. 

5.  On  the  proportion  of  the  Constituents, 

A  very  extensive  suite  of  experiments,  to  determine  the  proportions  of  the  constituents 
for  producing  the  best  gunpowder,  was  made  at  the  Essonne  works,  by  a  commission  of 
French  chemists  and  artillerists,  in  1794. 

Powders  in  the  five  following  proportions  were  prepared : — 


Nitre. 

CharcoAl. 

Sulphur. 

1 

76 

14 

10        Gunpowder  of  BAle. 

2 

76 

12 

12        Gunpowder  works  of  Grenelle. 

3 

76 

15 

9        M.  Guyton  de  Morvcau. 

4 

77-32 

13-44 

9-24   Idem. 

5 

77-5 

15 

7-5      M.  Riffault. 

GUNPOWDER. 


977 


The  result  of  more  than  two  hundred  discharges  with  the  proof-mortar  showed  that 
the  first  and  third  gunpowders  were  the  strongest;  and  the  commissioners  in  conse- 
quence recommended  the  adoption  of  the  third  proportions.  But  a  few  years  thereafter 
it  was  thought  proper  to  substitute  the  first  set  of  proportions,  which  had  been  found 
equal  in  force  to  the  other,  as  they  would  have  a  better  keeping  quality,  from  containing 
a  little  more  sulphur  and  less  charcoal.  More  recently  still,  so  strongly  impressed  have 
the  French  government  been  with  the  high  value  of  durability  in  gunpowders,  that  they 
have  returned  to  their  ancient  dosage  of  75  nitre,  12|  charcoal,  and  12|  sulphur.  In 
this  mixture,  the  proportion  of  the  substance  powerfully  absorbent  of  moisture,  viz.,  the 
charcoal,  is  still  further  reduced,  and  replaced  by  the  sulphur,  or  the  conservative  ingre- 
dient. 

If  we  inquire  how  the  maximum  gaseous  volume  is  to  be  produced  from  the  chemical 
reaction  of  the  elements  of  nitre  on  charcoal  and  sulphur,  we  shall  find  it  to  be  by  the 
generation  of  carbonic  oxyde  and  sulphurous  acid,  with  the  disengagement  of  nitrogen. 
This  will  lead  us  to  the  following  proportions  of  these  constituents. 


1  pnme  equivalent  of  nitre  -           •           - 
1                                 sulphur 
3                                 charcoal 

Hydrogen  =s  1. 

Per  cent 

102 
16 
18 

75-00 
11-77 
13-23 

136 

100-00 

The  nitre  contains  five  primes  of  oxygen,  of  which  three,  combining  with  the  three  of 
charcoal,  will  furnish  three  of  carbonic  oxyde  gas,  while  the  remaining  two  will  convert 
the  one  prime  of  sulphur  into  sulphurous  acid  gas.  The  single  prime  of  nitrogen  is, 
therefore,  in  this  view,  disengaged  alone. 

The  gaseous  volume,  on  this  supposition,  evolved  from  136  grains  of  gunpowder,  cqui 
valent  in  bulk  to  75|  grains  of  water,  or  to  three  tenths  of  a  cubic  inch,  will  be,  at  the 
atmospheric  temperature,  as  follows : — 


Carbonic  oxyde     .... 
Sulphurous  acid  .... 
Nitrogen        -        -        .        -        . 

Grains.       Cubic  Inches. 

42     =     141-6 
32     =      47-2 
14     =      47-4 

236-2 

being  an  expansion  of  one  volume  into  787*3.  But  as  the  temperature  of  the  gases  at 
the  mstant  of  their  combustive  formation  must  be  incandescent,  this  volume  may  be 
safely  estimated  at  three  times  the  above  amount,  or  considerably  upwards  of  two  thou- 
sand times  the  bulk  of  the  explosive  solid. 

But  this  theoretical  account  of  the  gases  developed  does  not  well  accord  with  Jie 
experimental  products  usually  assigned,  though  these  are  probably  not  altogether  exact. 
Much  carbonic  acid  is  said  to  be  disengaged,  a  large  quantity  of  nitrogen,  a  little  oxyde 
of  carbon,  steam  of  watery  with  carbureted  and  sulphureted  hydrogen.  From  experiments 
to  be  presently  detailed,  I  am  convinced  that  the  amount  of  these  latter  products  printed 
in  italics  must  be  very  inconsiderable  indeed,  and  unworthy  of  ranking  in  the  calculation ; 
for,  in  fact,  fresh  gunpowder  does  not  contain  above  one  per  cent,  of  water,  and  can 
therefore  yield  little  hydrogenated  matter.  Nor  is  the  hydrogen  in  the  carbon  of  any 
consequence. 

It  is  obvious  that  the  more  sulphur  is  present,  the  more  of  the  dense  sulphurous  acid 
will  be  generated,  and  the  less  forcibly  explosive  will  be  the  gunpowder.  This  is  suf- 
ficiently confirmed  by  the  trials  at  Essonne,  where  the  gunpowder  that  contained  12  of 
sulphur  and  12  of  charcoal  in  100  parts,  did  not  throw  the  proof-shell  so  far  as  that 
which  contained  only  9  of  sulphur  and  15  of  charcoal.  The  conservative  property  is, 
however,  so  capital,  especially  for  the  supply  of  our  remote  colonies  and  for  humid  cli- 
mates, that  It  justifies  a  slight  sacrifice  of  strength,  which  at  any  rate  may  be  compen. 
sated  by  a  small  addition  of  charge. 


;  i 


.:  I 


\i  I 


I 


1^1 


978 


GUNPOWDER. 
Table  of  Compontum^of  different  Gunpowders. 


Royal  Mills  at  Wallham  Abbey  • 
France,  national  establishment 
French,  for  sportsmen 
French,  for  mining  -        -        - 
United  States  of  America    - 
Prussia  -         -        -         -         - 
Russia       -        -        -        -        - 
Austria  (^musqitet)  -        -        - 
Spain         .        -        -        -        - 
Sweden  -        -        -        -        - 
Switzerland  (a  round  powder)     - 
Chinese  -        -        -        -        - 
Theoretical  proportions  (as  aboTe) 


Nitre. 


75 

75 

78 

65 

75 

75 

73 

72 

76-47 

76 

76 

75 

75 


Charcoal. 


78 


15 

12-5 

12 

15 

12-5 

13-5 

13-59 

17 

10-78 

15 

14 

14-4 

13-23 


Sulphur. 


10 

12-5 

10 

20 

12-5 

11-5 

12-63 

16 

12-75 

9 
10 

9-9 
11.77 


6.  On  the  Chemical  Examination  of  Gunpowders. 

I  nave  treated  five  different  samples :  1.  The  government  powder  made  at  Waltham 
Abbey;  2.  Glass  gunpowder  made  by  John  Hall,  Darlford  ;  3.  The  treble  strong  gun- 
powder  of  Charles  Lawrence  and  Son;  4.  The  Dartford  gunpowder  of  Pigou  and  Wilks; 
5.  Superfine  treble  strong  sporting  gunpowder  of  Curtis  and  Harvey.  Ihe  first  is 
coarse-grained,  the  others  are  all  of  considerable  fineness.  The  specific  gravity  of  each 
was  taken  in  oU  of  turnentine:  that  of  the  first  and  last  three  was  exactly  the  sam<v 
being  1-80 ;  that  of  the  second  was  1-793,  all  being  reduced  to  water  as  unity. 

The  above  density  for  specimen  first,  may  be  calculated  thus : — 


75  parts  of  nitre,  specific  gravity 
:5  parts  of  charcoal,  specific  gr. 
10  parts  of  sulphur,  specific  gr. 


2-000 
1-154 
2-000 


The  volume  of  these  constituents  is  55-5  (the  volume  of  their  weight  of  water  liemg 
100) ;  by  which  if  their  weight  100  be  divided,  the  quotient  is  1-80. 

The  specific  gravity  of  the  first  and  second  of  the  above  powders,  includmg  the  inter- 
stices of  their  grains,  after  being  well  shaken  down  in  a  vial,  is  102.  This  js  a  curioui 
result,  as  the  size  of  the  grains  is  extremely  different.  That  of  Pigou  and  Wilks,  sum- 
larly  tried,  is  only  099 ;  that  of  the  Battle  powder  is  1-03  ;  and  that  of  Curtis  and  Har- 
vey is  nearly  105.  Gunpowders  thus  appear  to  have  nearly  the  same  weight  as  water, 
under  an  equal  bulk ;  so  that  an  imperial  gallon  will  hold  from  10  pounds  to  10  pounds 

and  a  half,  as  above  shown.  ^       ,^  ...  .         u  .i,  »«j 

The  quantities  of  water  which  100  grains  of  each  part  with  on  a  steam  bath,  and 
absorb  when  placed  for  24  hours  under  a  moistened  receiver  standing  in  water,  arc  as 
follows  : — 

100  grains  of  Waltham  Abbey,  lose  M  by  steam  heat,  gain  0-8  over  water. 

of  HaU  -  -    0-5       -  -  -  2-2 

Lawrence   -  -    1-0       -  -  -  l-l 

Pigou  and  Wilks    -    0*6      -  -  -  2-2 

Curtis  and  Harvey  -    0-9       -  -  -  1*7 

ITi us  we  perceive  that  the  large  grained  government  powder  resists  the  hygrometric 
influence  belter  than  the  others ;  among  which,  however,  Lawrence's  ranks  nearly  as 
hi^h.     These  two  are  therefore  relatively  the  best  keeping  gunpowders  of  the  series. 

The  process  most  commonly  practised  in  the  analysis  of  gunpowder,  seems  to  be  toler- 
ably exact.  The  nitre  is  first  separated  by  hot  distilled  water,  evaporated  and  weighed. 
A  minute  loss  of  salt  may  be  counted  on,  from  its  known  volatility  with  boiling  water. 
I  hare  evaporated  always  on  a  steam  bath.  It  is  probable  that  a  small  portion  of  the 
lighter  and  looser  constituent  of  gunpowder,  the  carbon,  flies  off  in  the  operations  of 
corning  and  dusting.  Hence,  analysis  may  show  a  small  deficit  of  charcoal  below  the 
synthetic  proportions  originally  mixed.  The  residuum  of  charcoal  and  sulphur  left  on 
the  double  filter-paper,  being  well  dried  by  the  heat  of  ordinary  steam,  was  estimated,  as 
usual,  bv  the  difference  of  weight  of  the  inner  and  outer  papers.  This  residuum  was 
cleared  off  into  a  plalina  capsule  with  a  tooth-brush,  and  digested  in  a  dilute  solution 
of  potash  at  a  boiling  temperature.  Three  parts  of  potash  are  fully  sufficient  to  dis- 
solve out  one  of  sulphur.     When  the  above  solution  is  thrown  on  a  filter,  and  washed 


GUKPOWDER. 


979 


first  with  a  very  dilute  solution  of  potash  boiling  hot,  then  with  boiling  water,  and  after- 
wards dried,  the  carbon  will  remain  ;  the  weight  of  which  deducted  from  that  of  the  mixed 
powder,  will  show  the  amount  of  sulphur. 

I  have  tried  many  other  modes  of  estimating  the  sulphur  in  gunpowder  more  directly, 
but  with  little  satisfaction  in  the  results.  When  a  platina  capsule,  containing  gunpowder 
spread  on  its  bottom,  is  floated  in  oil,  heated  to  400**  Fahrenheit,  a  brisk  exhalation  of 
sulphur  fumes  rises,  but,  at  the  end  of  several  hours,  the  loss  does  not  amount  to  mort 
than  one  half  of  the  sulphur  present. 

The  mixed  residuum  of  charcoal  and  sulphur  digested  in  hot  oil  of  turpentine  gires 
up  the  sulphur  readily;  but  to  separate  again  the  last  portions  of  the  oil  from  the  char- 
coal or  sulphur,  requires  the  aid  of  alcohol. 

When  gunpowder  is  digested  with  chlorate  of  potash  and  dilute  muriatic  acid,  at  a  mod- 
orate  heat  in  a  retort,  the  sulphur  is  acidified ;  but  this  process  is  disagreeable  and  slow, 
and  consumes  much  chlorate.  The  resulting  sulphuric  acid  being  tested  by  nitrate  of 
baryta,  indicates  of  course  the  quantity  of  sulphur  in  the  gunpowder.  A  curious  fact 
occurred  to  me  in  this  experiment.  After  the  sulphur  and  charcoal  of  the  gunpowder 
had  been  quite  acidified,  I  poured  some  solution  of  the  baryta  salt  into  the  mixture,  but 
no  cloud  of  sulphate  ensued.  On  evaporating  to  dryness,  however,  and  redissolving,  the 
■itrate  of  baryta  became  effective,  and  enabled  me  to  estimate  the  sulphuric  acid  gene- 
rated; which  was  of  course  10  for  every  4  of  the  sulphur. 

The  acidification  of  the  sulphur  by  nitric  or  nitro-muriatic  acid  is  likewise  a  slow  and 
unpleasant  operation. 

By  digesting  gunpowder  with  potash  water,  so  as  to  convert  its  sulphur  into  a  sulphu- 
rct,  mixing  this  with  nitre  in  great  excess,  drying  and  igniting,  I  had  hoped  to  convert 
the  sulphur  readily  into  sulphuric  acid.  But  on  treating  the  fused  mass  with  dilute 
nitric  acid,  more  or  less  sulphurous  acid  was  exhaled.  This  occurred  even  though 
chlorate  of  potash  had  been  mixed  with  the  nitre  to  aid  the  oxygenation. 

The  following  are  the  results  of  my   analyses,  conducted   by  the  fir:t  described 
method  : 


— 

100  graii:8  afford,  of 

Nitre. 

Charcoal. 

Sulphui. 

1 
Water. 

Waltham  Abbey    -    - 

74-5 

14-4 

10-0 

1-1 

Hall,  Dartford  -     -     - 

76-2 

14-0 

9-0 

0-5  loss  0-3 

Pi^ou  and  Wilks  -     - 

77-4 

13-5 

8-5 

0-6 

Curtis  and  Harvey     - 

76-7 

12-5 

9-0 

M  loss  0-7 

Battle  gunpowder       -    ! 

77-0 

13-5 

8-0 

0-8  loss  0-7 

It  is  probable,  for  reasons  already  assigned,  that  the  proportions  mixed  by  the  manu- 
facturers may  differ  slightly  from  the  above. 

The  English  sporting  gunpowders  have  long  been  an  object  of  desire  and  emulation  in 
France.  Their  great  superiority  for  fowling  pieces  over  the  product  of  the  French  national 
manufactories,  is  indisputable.  Unwilling  to  ascribe  this  superiority  to  any  genuine  cause, 
M.  Vergnaud,  captain  of  French  artillery,  in  a  little  work  on  fulminating  powders  lately 
published,  asserts  positively,  that  the  English  manufacturers  of  *  poudre  de  chasse'  are 
guilty  of  the  *  charlatanisme'  of  mixing  fulminating  mercury  with  it.  To  determine  what 
truth  was  in  this  allegation,  with  regard  at  least  to  the  above  five  celebrated  gunpowders, 
I  made  the  following  experiments. 

One  grain  of  fulminating  mercury,  in  crystalline  particles,  was  mixed  in  water  will 
200  grains  of  the  Wa\dham  Abbey  gunpowder,  and  the  mixture  was  digested  over  a 
.amp  with  a  very  little  muriatic  acid.  The  filtered  liquid  gave  manifest  indications  of 
the  corrosive  sublimate,  into  which  fulminating  mercury  is  instantly  convertible  by  mu 
riatic  acid  ;  for  copper  was  quicksilvered  by  it ;  potash  caused  a  white  cloud  in  it  that 
oecame  yellow,  and  sulphnreted  hydrogen  gas  separated  a  dirty  yellow  white  precipi- 
tate of  bisulphuret  of  mercur\'.  When  the  Waltham  Abbey  powder  was  treated  alone 
with  dilute  muriatic  acid,  no  effect  whatever  was  produced  upon  the  filtered  liquid  by  the 
sulphureted  hydrogen  gas. 

200  grains  of  each  of  the  above  sporting  gunpowders  were  treated  prt>ei».'*y  in  the 
same  way,  but  no  trace  of  mercury  was  obtained  by  the  severest  tests.  Since  by  this 
process  there  is  no  doubt  but  one  10,000th  part  of  fulminating  mercury  could  be  de- 
tected, we  may  conclude  that  Captain  Vergnaud's  charge  is  groundless.  The  superiority 
of  our  sporting  gunpowders  is  due  to  the  same  cause  as  the  superiority  of  our  cotton 
fabrics— the  care  of  our  manufacturers  in  selecting  the  best  materials,  and  their  skill  ia 
combining  them. 

I  shall  subjoin  here  some  miscellaneous  observations  upon  gunpowder. 


980 


GYPSUM. 


GUTTA  PERCHA. 


I 


In  Bengal,  mixing  is  performed  by  shutting  up  the  ingredients  in  barrels,  which  are 
turned  either  by  hand  or  machinery ;  each  containing  50  lbs.  weight,  or  more,-  of  small 
brass  balls.  They  have  ledges  on  the  inside,  which  occasion  the  balls  and  composition 
to  tumble  about  and  mingle  together,  so  that  the  intermixture  of  the  ingredients,  after 
tne  process  has  been  eone  through,  cannot  fail  to  be  complete.  The  operation  is  con- 
imued  two  or  three  hours ;  and  I  think  it  would  be  an  improvement  in  Hier  Majesty  s 
svstemofmanufactureif  this  method  of  mixing  were  adopted. 

'  In  En«»land  two  or  three  pints  of  water  are  used  for  a  42  lb.  charge  :  but  the  quantity 
is  varisWe ;  both  the  temperature  and  the  humidity  of  the  atmosphere  influence  it. 

Bramah's  hydrostatic  press,  or  a  very  strong  wooden  press  working  with  a  powerful 
screw,  lever,  and  windlass,  constitutes  the  description  of  mechanism  by  which  density  is 
imparted  to  gunpowder.  The  incorporated  or  mill-cake  powder  is  laid  on  the  bed  or 
follower  of  the  press,  and  separated,  at  equal  distances,  by  sheets  of  copper,  so  that  when 
the  operation  is  over,  it  comes  out  in  large  thin  solid  cakes,  or  strata,  distinguished  by 
the  term  press-cake.  The  mill-cake  powder  at  Waltham  Abbey,  is  submitted  to  a  mean 
theoretic  pressure  of  70  to  75  tons  per  superficial  foot.'  r  v     *      *i.  ♦ 

Gunpowder  should  be  thoroughly  dried,  but  not  by  too  high  a  degree  of  heat ;  that 
of  140"  or  150°  of  Fahrenheit's  thermometer  is  sufllcient.  It  appears  to  be  of  no  conse- 
quence whether  it  be  dried  by  solar  heat,  by  radiation  from  red-hot  iron,  as  m  the  gloom 
Rtove,  or  by  a  temperature  raised  by  means  of  steam.  Her  Majesty's  gunpowder  is  dried 
by  the  last  two  methods.    The  grain  should  not  be  suddenly  exposed  to  the  highest  degree 

ol  heat,  but  gradually.  .v       j ^a,^.,^  «f 

The  method  of  trial  best  adapted  to  show  the  real  inherent  strength  and  goodness  of 
gunpowder,  appears  to  be  an  eight  or  ten  inch  iron  or  brass  mortar,  with  a  truly  spherical 
solid  shot,  having  not  more  than  one  tenth  of  an  inch  windage,  and  fired  with  a  low 
charge.  The  eight-inch  mortar,  fired  with  two  ounces  of  powder,  is  one  of  the  eslabUshea 
methods  of  proof  at  Her  Majesty's  works.  Gunpowders  that  range  equally  in  this  mode 
of  trial,  may  be  depended  on  as  being  equally  strong.  r  v^ 

Another  proof  is  by  four  drachms  of  powder  laid  in  a  small  neat  heap,  on  a  clean,  PoUshed 
copper  plate  3  which  heap  is  fired  at  the  apex,  by  a  red  hot  iron.  The  explocMon  shou  4 
be  sharp  and  quick  ;  not  tardy,  nor  lingering;  i^^hould  produce  a  sudden  concussion  m 
the  air  f  and  the  force  and  power  of  that  concussion  ought  to  be  judged  of  by  ^^P^^^J 
with  that  produced  by  powder  of  known  good  quality.  No  sparks  should  fly  off,  nor  should 
beads,  or  globules  of  alkaline  residuum,  be  left  on  the  copper.  If  the  copper  be  lelt 
clean,  i.  e.  without  gross  foulness,  and  no  lights,  i.  e  sparks,  be  seen,  Uie  »n?'-edienU 
may  be  considered  to'have  been  carefully  prepared,  and  the  powder  to  have  been  weU 
manipulated,  particularly  if  pressed  and  glazed ;  but  if  the  contrary  be  the  result,  there 
has  been  a  want  of  skill  or  of  carefulness  manifested  in  the  manufacture. 

«  Gunpowder,"  says  Captain  Bishop,  «  explodes  exactly  at  the  600«>  of  heat  by  Fa^ 
renheit's  thermometer;  when  gunpowder  is  exposed  to  500°  it  alters  its  "f  "^f  ^l;^«- 
ther ;  not  only  the  whole  of  the  moisture  is  driven  off,  but  the  saltpetre  and  sulphur  arc 
aciuillv  reduced  to  fusion,  both  of  which  liquefy  under  the  above  degree.  The  powder, 
on  coofing,  is  found  to  have  changed  its  color  from  a  gray  to  a  deep  black  j^he  grain  Hm 
oecome  extremely  indurated,  and  by  exposure  even  to  very  moist  air,  it  then  suflers  no 
alteration  bv  imbibing  moisture."  ,v     r  ii,.«r;n« 

The  mill'for  grinding  the  gunpowder  cake  may  be  understood  from  the  louowing 


981 


rpmeaentation  (  A<7.   740) ;    p,   is  the  water  wheel,  which  may  drive  several  pair.<  of 
nLe^rrtwo  vertical  bevel  wheels,  fixed  upon  the  axis  of  the  great  wheel-  r.  r.  two 


horizontal  bevel  wheels  working  in  q,  q,  and  turning  the  shafts  «,  » ;  t,  t,  two  horizontal 
spur  wheels  fixed  to  the  upper  part  of  the  vertical  shafts,  and  driving  the^arge  wheeh 

i    yJ"". *^^  -^""^^  ""^ ^^'''  ^^"^''  ^^^^^  "^ fi^«^  the  runners  v,  v,  which  traversl ur^n 
the  bed  stone  «,,  u, ;  xz,  are  the  curbs  surrounding  the  bed  stone  to  prevent  the  powdS 

bXt^ieTnd  clirr  '''  ""P"'    """'  '  "P""  ^^^  *  '''^'  ^"^  -"  »  a  sec&'SS 

r..t7fT''^^'  ^na/y*w  of.  M.  Bolley  dissolves  out  the  sulphur  from  charcoal  in  gun- 
powder (previously  freed  from  its  nitre  by  water)  by  digesting  it,  at  a  boiling  heat  fS?  2 
hours,  with  the  solut  on  of  20  times  its  weight  of^ufphite  of 'sX,  wh  ch  b  thereby 
converted  into  hyposulphite  To  the  mixture  water  must  be  added,  as  it  is  wasTed  bv  the 
boiling.  I  the  residum  be  heated  on  platinum  foU,  it  wiU  exha  e  sulphuTff  this  had 
not  been  all  removed  by  the  sulphurous  salt  "«F"ur,  u  laia  naa 

GUTTA  PERCHA  (Native).  "Although  the  trees  yielding  this  substance  abound 
hv  Dr  w't  "V*''  ^"^'^  Archipelago,  the  first  notice  tlken  of  it  appears thavT^^ 
^L?  T  ^''''ISomene,  in  a  letter  to  the  Bengal  Medical  Board,  in  the  beu^nlin^f 
1843,  wherein  he  recommends  the  substance  as  likely  to  prove  us;ful  for  some  sir^ic^l 

taken  to  Europe  by  Dr.  D  Almeida,  who  presented  it  to  the  Royal  Society  of  Arts  of 
London,  but  it  did  not  at  first  attract  much  attention,  as  the  Society  sim^y  ^knowled^ed 

J^'n'^lilP^iS^  ^^  ^^*  i  '^}'''^^  .^^^^^^^  ^f*^'  *h«y  th^^gbt  proper  to  a^^rdTgold  mSlal 
to  Dr.  W.  Montgomerie  for  a  similar  service.    Now,  as  the  discovery  of  Wh  of ^he^ 

ftTnZT'!?'"^.P''"^J^V'^  "P""  '^^  same  foundation,  the  accidS  famt  Tn  wtth 
It  m  the  hands  of  some  Malays,  who  had  found  out  its  greatest  peculiaritv  a^d  LvaM 
themselves  thereof,  manufactured  it  into  whips,  which  ^ere  broLht  nto  town  f^ilf 
there  does  not  appear  any  plausible  reason  for  the  passing  over  the  first  and  rewlrdtt 
die  second.  Both  gentlemen  are  highly  to  be  comm^ended^for  endeavoi^rirt^^ 
iTpr^^^!  n"''*"^  A'*"^'r'"  ^.^'"^  h««  P"-"^^^  ««  "«^f"l  and  interesting!  The  gutS 
^nhth!r«K^  rV\^  ^"i?'*'^  "'"'^  *'*^°*^«"'  ^°d  ^'  y^t  but  little  bf  ng  know^n  o^ 
published  about  ,t.  I  would  now  propose  to  supply,  to  the  best  of  my  ability  thUdesT 
deratum.  and  give  a  description  of  tW  tree,  its"^  product  and  uses,  so  for  as  ^i  h^  ZZ 
made  available  for  domestic  and  other  purposes  \n  the  place  of  its  origfi 

The  gutta  percha.  tree,  or  gutta  tuban,  as  it  ought  more  properly  to  be  called  th^ 

E^  .h  f  r^T^^  ^K;:"""'  ^''l'^'^  ^^^°"^^  *«  the  nature  far£ly%Vel  but  S.^ 
much  from  all  described  genera,  having  alliance  with  both  ^cAra/and^a,Sa  but  diSn^ 

i^enT'  fZ  r  hJT  ^\'^^'  ^  ""^  ^'^P^^^^  *«  th'"k  it  »  entitled  rr^k  La  ne^ 
fl^L  w  f  '  *'^"'^^«''^'  endeavour  to  give  its  general  character,  leaving  the  honourTf 
nammg  it  to  some  more  competent  botanist,  especially  as  I  have  not  quiteltisfied  mvL^f 
regarding  the  stamens,  from  want  of  specimens  for  observations  ^  «atisned  myself 
'  The  tree  is  of  a  large  size,  from  60  to  70  feet  in  height,'  and  from  2  to  3  fp«t  in 
diameter.  Its  general  appearance  resembles  the  genus  Durio,  or  weH  known  7>^ 
so  much  so  as  to  strike  the  most  superficial  observer.   ThfunTeV  su7face  of  tL  le^H^^^^^ 

"It  is  quite  extraordinary  how  difficult  it  is  to  obtain  specimens  of  either  the  flower  or 
the  fruit  of  this  tree  and  this  is  probably  the  reason  of  its  not  havinrbLeuTar Her 
recognised  and  described  by  some  of  the  many  botanists  who  have  visite    these  mrts 

"Only  a  short  time  ago  the  tuban  tree  was  tolerably  abundant  on  the  .  and  oK L o 
pore ;  but  already  all  the  large  timber  has  been  felled'  and  few.  if  any!o;her  thL^^^^^^^^ 
p  ants  are  now  to  be  found.  The  range  of  its  growth,  however  apDears  to  Kp  o^^  T 
tie,  it  being  found  all  up  the  Malayan  Peninsula,  \s  Tar  a;Tnrnywtr^Thr' 
ascertained  it  to  be  abundant ;  although,  as  yet.  the  inhabitants  do  not  stnToL  aware 
of  the  faet.  several  of  the  mercantile  houses  there  having  sent  down  orders  to  Si^A^'e 
for  supplies  of  the  article,  when  they  have  the  means  of  supplv  close  at  ham?  ^^^""P*"^® 

"  The  localities  it  particularly  likes  are  the  alluvial  tracts  alono-  the  foot  of  hills  «.h»r. 
.t  flourishes  luxuriantly,  forming,  in  many  spots,  the  principal  portion  onLiunffl^B^ 

IS  dSi'o'If  ttiotr"">r  "'T'"  °'  "■«  ''*'  "^  Wa^^-'"  abundance  a^ndwwi 
spread  a.itusion,  the  gutta  will  soon  become  a  verv  scarrp  nrtJ^lo  ;r  o,.r.,„  «,^  ^  •  j     . 

means  ^be  not  adopted  in  its  collection  than  thoTe^rp^^se^t'lTr^L^^^^^ 

-  T\m  mode  in  which  the  natives  obtain  the  gutta  is  by  cutting  down  the  trees  of  full 
growth,  and  ringing  the  bark  at  distances  of  about  12  to  18  inches  apart  LidTlac  nl  a 
cocoa-nut  shell,  sp^the  of  a  palm  or  such  like  receptacle,  under  the  fallen  J^^lt 
to  receive  the  m.lky  sap  that  mmediately  exudes  u^n  every  fresh  InS  ThU 
ap  18  collected  in  baniboos,  taken  to  thetr  houses,  alid  boile/  in  order  t«3rive  off 
the  watery  parUcles  and  inspissate  it  to  the  consistence  it  finally  assumes.     A   hou^S 


If. 


I 


.  •J 


982 


GUTTA  PERCHA. 


the  Drocesa  of  boilincr  appears  necessary  when  the  gutta  is  collected  in  large  quantities. 
^  a  U^e  be  freS  ly  ^ounSed.  a  small  quantity  allowed  to  exude,  and  it  be  collected  and 
moulded  in  the  iSnd.  it  will  consolidate  perfectly  in  a  few  minutes,  and  have  all  the 

^^r^rn^itltuitrpCelh^li"  r  is  of  a  grayish  white;  but  as  brought  to  market,  it 
is  more  ord  nar?ly  found  of  a  reddish  hue,  arising  from  chips  of  bark  that  fall  mto  the  sap 
n  X  act  of  mak^ing  the  incisions,  and  which  yield  their  colour  to  it.    Besides  these  acci- 
denUl  chips  there  is  a  great  deal  of  intentional  adulteration  by  ^^Y^^^^  wto  .„n 
materials.    Some  specimlns  I  have  lately  seen  brought  to  market  could  not  l^aye  con- 
tS  much  less  than  i  lb.  of  impurities ;  and  even  in  the  purest  specimens  I  could 
obut  Tsurglal  purpies.  one  pund  of 'the  substance  yielded  on  being  cleansed  one 
ou^c^  of  impurities^;  fJrtunktely,  U  is  neither  difficult  to  detect  or  f^^^^%^l''^.?^^ 
foreign  matter,  it  being  only  necessary  to  boil  it  n  water  until  well  softened,  roll  ou     he 
eubsfance  into  thin  sheets,  and  then  pick  out  al  impurities,  which  is  easily  done  ate 
gutta  does  not  adhere  to  anything,  and  all  foreign  matter  is  merely  ent^^glf^^  "^/^^^ 
fibres,  not  incorporated  in  its  substance.    Tlie  quantity  of  gutta  obtained  from  each  tree 
varies  from  5  to^20  catties,  so  that,  taking  the  average  at  10  catties,  which  is  a  tolerably 
liberal  one  it  will  require  the  destruction  of  ten  trees  to  produce  one  picul.     JNow,  the 
qSv  eiporTed  from  Singapore  to  Great  Britain  and  the  continent,  from  1st  January 
?8S    o^heVesen^^^^^^^^^  f minted  to  6,918  .iculs.  to  obtain  which  69,180  trees  must 
have  been  sacrificed.     How  much  better  would  it,  therefore,  be  to  adopt  the  method  ot 
tappin-  the  tree,  practised  by  the  Burmese  in  obtaining  the  caoutchouc  from  the  Funs 
e£itica  (yiz.  to  m^e  oblique  incisions  in  the  bark,  placing  bamboos  *«  r^^^^^^ /^^  «*P 
which  runs  out  freely),  thii  to  kiU  the  goose  in  the  manner  they  are  at  present  doing ! 
^e    ihZ  would  not  at  first  get  so  much  from  a  single  tree,  but  the  ultimate  gain 
would  be  incalculable,  particularly  as  the  tree  seems  to  be  one  of  slow  growth;  by  no 
mearS  so  rapid  as  the  ^icus  elastica.     I  should  not  be  surprised,  if  the  demand  increases 
and  the  pre^nt  method  of  extermination  be  persisted  m,  to  find  a  sudden  cessation  of  the 

*""^rop^fi«  of  the  0^tta.-ThiB  substance  when  fresh  and  pure  is   as  already  men- 
tioned. SI  dirty  white  colour,  and  of  a  greasy  feel,  with  a  pecuhar  leathery  smell.   It  is 
not  affected  by  boiling  alcohol,  but  dissolves  readily  in  boiling  sp>nts  of  turpentine,  also 
?n  naphtha  an^d  coal-tlr.     A  good  cement  for  luting  bottles  and  other  purposes  is  forn^ed 
byWling  together  equal  paFts  of  gutta  and  coal-tar  and  resm.     I  am  indebted  for  this 
hfnt  to  Mr    Little,  surgeon,  and  the  above  were  his  proportions.     I  have,  however, 
found  it  necessary    o  put  two  parts  of  the  gutta,  that  is,  one-half  instead  of  one-th.rd.  to 
enable  the  cement  to^tand  the  heat  of  this  climate.    When  reauired  for  use,  it  can 
Xays  be  made  plastic  by  putting  the  pot  containing  it  over  the  ^re  for  a  few  minutes. 
TheTutVa  itself ^is  highl v  iuflammable ;  a  strip  cut  off  takes    ight    and  burns  with 
a  brifht  flame,  emitting  sparks,  and  dropping  a  black  residuum  in  the  manner  of  seal- 
rnfwax,  wbiJh  in  its  combustion  it  very  much  resembles.     But  the  great  peculiarity 
of  tlTis  substance,  and  that  which  makes  it  so  eminently  useful  for  many  purp<«e. 
L  the  effect  of  billing  water  upon  it.     When  immersed  for  a  few  minutes  m  water 
above  ?50°  Fahr.,  it  becomes  sSt  and  plastic,  so  as  to  be  capable  of  being  moulded 
Tany  required  shape  or  form,  which  it  retains  upon  cooUng.    If  a  strip  of  it  be  cut  off 
aU  plunged  into  boiling  water,  it  contracts  in  size  both  in  length  and  breadth.    This 
La  very  anomalous  and  remarkable  phenomenon,  apparently  opposed  to  all  the  laws  of 

^'%  is  this  plasticity  when  plunged  into  boiling  water  that  has  allowed  of  its  being 
annliod  to  so  many  useful  purposes,  and  which  first  induced  some  Malays  to  fabricate  it 
Xwhips,  whTh  were  brought  into  town,  and  led  to  its  further  notice.    The  natives  have 
eXequen  ly  extended  their  manufactures  to  buckets,  basins,  and  jugs,  shoes   traces, 
veSels  for  cooling  wines,  and  several  other  domestic  uses;  but  the  number  of  patents 
[ately  taken  out  for  the  manufacture  of  the  article  in  England,  provee  how  much  atten- 
tion It  has  already  attracted,  and  how  extensively  useful  it  is  likely  to  become.     Of  all 
•  the  purposes,  however,  to  which  it  may  be  adapted,  none  is  so  valuable  as  its  applica- 
bilitrto  the  practice  of  surgery.     Here  it  becomes  one  of  the  most  useful  auxilmries 
Tilt  branch  of  the  healing  art  which  of  all  is   the  least  coniectural.     Its  easy 
elasticity  and  power  of  retaining  any  shape  given  to  it  when  cool,  at  once  pointed 
Ft  out  as  suitable  for  the  manufacture  of  bougies ;   and   accordingly  my  predecessor 
Dr  W  Monttromerie,  availed  himself  of  this,  made  several  of  the  above  instruments,  and 
recommended  the  use  of  it  to  the  Bengal  Medical  Board.     But,  like  many  other  good 
hbts  Tr  want  of  sufficient  inquiry,  I  fear  it  was  disregarded.     The  practice,  how- 
eTer   h^  been  continued  by  me.  and  I  find  many  advantages  in  the  use  of  this  sub- 
stance     It  also  answers  vefy  well  for  the  tubes  of  syringes,  which  are  always  gc  t.ng 
out  of' order  in  this  country,  when  made  of  caoutchouc.     But  my  late  experiments  have 
g?ven  it  a  much  higher  value,  and  proved  it  the  best  and  easiest  application  ever  yet 


GUTTA  PERCHA. 


983 


discovered  in  the  management  of  fractures,  combining  ease  and  comfort  to  the  patient, 
and  very  much  lessening  the  trouble  of  the  surgeon.  When  I  think  of  the  farrago  of 
bandages  and  splints  got  rid  of,  the  lightness  and  simplicity  of  the  application,  the  gutta 
would  be  no  trifling  boon  to  mankind,  were  it  to  be  used  solely  for  this  and  no  other  pur- 
po.se.  The  injuries  coming  under  my  observation,  wherein  I  have  tested  its  utility,  have, 
as  yet,  only  been  two  compound  fractures  of  the  leg,  and  one  of  the  jaw  ;  but  so  admira- 
bly has  it  not  only  answered,  but  exceeded  my  expectations,  that  I  should  think  myself 
culpable  in  not  giving  the  facts  early  publicity.  Its  utiUty  in  fracture  of  the  lower  jaw 
must  at  once  strike  any  surgeon.  So  well  does  it  mould  itself  to  every  sinuosity,  that  it 
is  more  like  giving  the  patient  a  new  bone  than  a  mere  support.  A  man  lately  brought 
into  hospital,  who  had  his  lower  jaw  broken  by  the  kick  of  a  horse,  and  which  was  so 
severe  as  to  cause  haemorrhage  from  the  ears,  smashing  the  bone  into  several  fragments, 
was  able  to  eat  and  speak  three  days  after  the  accident,  and  felt  so  well  with  his  gutta 
splint  that  he  insisted  on  leaving  the  hospital  within  ten  days.  My  mode  of  applying 
this  substance  to  fractures  of  the  leg  is  as  follows : — 

*•  Tlie  gutta  having  been  previously  rolled  out  into  sheets  of  convenient  size,  and  about 
one-fourth  of  an  inch  in  thickness,  is  thus  kept  ready  for  use.  When  required,  a  piece  of 
the  necessary  length  and  breadth  is  plunged  into  a  tub  of  boiling  water.  TTie  limb  of 
the  patient  is  then  gently  raised  by  assistance,  making  extension  in  the  usual  manner. 
The  surgeon,  having  ascertained  that  the  broken  bone  is  in  its  place,  takes  the  sheet  of 
gutta  out  of  the  hot  water,  and  allows  it  to  cool  for  a  couple  of  minutes.  It  is  still  soft 
and  pliable  as  wash  leather.  Place  it  whilst  in  this  state  under  the  limb,  and  gently 
lower  the  latter  down  on  it.  The  gutta  is  then  to  be  brought  round  and  moulded  care- 
fully to  the  whole  of  the  back  and  sides  of  the  leg,  bringing  the  edges  close  together,  but 
not  uniting  them.  If  there  be  any  superfluous  substance,  it  can  be  cut  off  with  scissors, 
leaving  an  open  slit  down  the  front  of  the  leg.  You  have  now  the  leg  in  a  comfortable, 
soft,  and  smooth  case,  which  in  ten  minutes  will  be  stiff  enough  to  retain  any  shape  the 
surgeon  may  have  given  it,  and  which  will  also  retain  the  bone  in  situ.  Place  the  leg 
so  done  up  on  a  double  incline  plane,  and  secure  it  thereto  by  passing  three  of  the 
common  loop  bandages  around  the  whole ;  that  is,  one  at  the  top,  one  in  the  middle, 
and  one  at  the  lower  end.  Let  the  foot  be  supported  by  a  foot-board,  and  a  case  of 
gutta  put  over  the  dorsum  of  the  foot,  to  bear  off  the  pressure  of  the  small  bands 
generally  used  to  secure  it  to  the  board.  Having  done  this,  the  surgeon  need  not  cause 
the  patient  another  twinge  of  pain  until  he  thinks  he  can  use  the  leg,  or  he  deems 
the  bone  sufficiently  united  to  bear  the  weight  of  his  patient.  If  it  be  a  compound 
fracture,  it  will  be  only  necessary  to  untie  the  loop  bandages,  separate  the  edges  of  the 
gutta  splint  to  the  required  distance,  wash  and  cleanse  the  limb  without  shifting  any- 
thing except  the  dressings,  and.  having  done  so,  shut  it  up  again.  The  most  perfect 
cleanliness  can  be  maintained,  as  the  gutta  is  not  affected  by  any  amount  of  ablution  • 
neither  is  it  soiled  or  rendered  offensive  by  any  discharge,  all  which  washes  off  as  easily 
from  the  gutta  case  as  from  oil-cloth.  I  have  had  a  patient  where  the  tibia  protruded 
through  the  integuments  fully  two  inches,  walking  about  in  six  weeks  from  the  injury, 
with  a  leg  as  straight  and  well  formed  as  ever  it  had  been.  It  is  quite  obvious,  there^ 
fore,  that  if  it  answers  so  well  for  compound,  it  will  answer  equally,  if  not  better,  for 
simple  fractures  ;  and  that  any  broken  bone  capable  of  receiving  mechanical  support  can 
be  supported  by  the  gutta  better  than  by  any  other  contrivance ;  for  it  combines  light- 
ness, and  smoothness,  and  durability,  and  a  capability  of  adjustment  not  possessed  by 
any  other  known  substance.  All  new  experiments  have  to  run  the  gauntlet  of  opposi- 
tion ;  and  I  do  not  suppose  that  these  recommendations  will  prove  any  exception  to  the 
rule ;  but  all  I  ask  of  any  surgeon  is,  to  try  the  experiment  ere  he  argues  on  its  pro- 
priety, and  I  feel  fully  convinced  that  all  other  splints  and  bandages  will  be  consioned 
to  the  tomb  of  the  Capulets.  There  are  some  other  uses  for  which  I  have  tried  this'sub- 
etance,  viz.,  as  capsules  for  transmission  of  the  vaccine  virus,  which  ought  to  keep  well 
when  thus  protected,  for  it  is  most  perfectly  and  hermetically  sealed  ;  but  I  have  not 
had  sufficient  experience  in  this  mode  of  using  it  to  pronounce  decidedly^  on  its  merits. 
I  am  at  present  trying  the  effects  of  it  on  ulcers,  by  enclosing  the  ulcerated  limb  in  a 
case  of  gutta,  so  as  to  exclude  all  atmospheric  air ;  and  so  far,  the  experiment  promises 
success. 

"Since  writing  the  foregoing  observations,  I  have  had  an  official  intimation  from 
Penang,  of  the  vaccine  virus  transmitted  in  the  gutta  capsules  having  been  received  in 
good  order,  and  of  its  having  succeeded  satisfactorily.  I  have  also  opened  a  capsule 
containing  a  vaccine  crust  that  had  been  kept  here  for  one  month,  and  it  also  seems  to 
have  lost  none  of  its  efficacy,  as  the  case  inoculated  has  taken.  This  Avill  appear  the 
more  striking  when  it  is  recollected  that,  to  preserve  the  vaccine  virus  hitherto  in 
Singapore,  even  for  a  few  days,  has  been  almost  impossible ;  that  this  settlement,  not- 
withstanding every  exertion  on  the  part  of  both  private  and  public  practitioners,  ha* 
been  without  the  benefit  of  this  important  prophylactic  for  an  interval  sometimes  of  two 


984  GUTTA  PERCHA. 

J  .!,„»  ..  .11  limes   the  obtainins  and  transmitting  this  desirable  remedy  has 

years ;  and  that  at  ^'  ''™f  V^^'^,""  "o  all  the  medical  officers  T  have  cter  met  with  in 
Una  cause  oftroubk  and  d^fficuHy^^^^^ 

*'^'"  »"'  rl-iUf  T/nin";  thel  t^,  ^aUotrntSn""' U^  having  a  disagreeable 
??e  smell,  although  peculfar,  is  neither  strong  ""^nP  f*^  •.  ^  d"a  1  ge  & 

Again  ;  it  appears  to  me  that,  >f.j¥  ^^^^^^^^^  I'JJa  can  be  obtained  here  in  a 

as  being  necessary  for  cleaning  it  is  superfluous.  ^J«  ^""^  .f*  ^i  softened,  and  then 
perfectly  pure  state  by  simply  boding  it  in  hot  ^?f  ;,,""^  ^^j  J^'^^'^ft;^^^^^  be  easily 
rolled  out  Into  thin  sheets,  xvl^en  as  I  have  ^^^^.^f/^^'/^/^'^'^e",^^^^^^^^  a  higher 

Eiit^eTrd't^iimiirtLrtorirrc^'an^ 

-cot^torjer^XlumrT^^^^^^^^ 

^r  "oSchoic  ^hen  tLse  materials  have  been  mixed.  ^^^  S^'CnoVaSS  is  to  b^ 
l^iler  and  heated  under  pressure  to  a  temperature  of  from  260°  to  300  if.  and  "  lo  oe 
WHn  this  stlte  for  a  period  varying  from  half  an  hour  to  two  hours,  according  to  the 
t^ciness  ofl^e  mat?^^^^^^^^  prefers  for  eifecting  the  union  of  the  sulphurous  const.^ 

tnent  the  foCin^^^^^  to  tl^e  masticating  machine.     1st.  He  subjects  the  purified 

Inni  nTrcha  tithe  S)nioined  action  of  steam  and  the  fumes  of  orpiment  and  sjilphur 
lited^  th^'proportr^^  in  a  metal  chamber,  provided  with  a  ^Jeam-tigh   cover 

^^rpdhv  screw  bolts.  There  is  also  a  steam  boiler  comiected  therewith,  and  wlien  the 
wfnitiS  to  about  280°  Fahr,  a  fire  is  lighted  beneath  the  pot  containing  the 

^  rl?2,rpd      In  from  half  an  hour  to  two  hours  the  sulphuring  is  finished.     Or.  the 

ftrl^roha  mav   £  Tubbed   strongly  over  with  the  sulphurous  mixture  and  then 

C^ted^ither  SJ^or  wiS  the  aid  of  ftU  or  coated  in  the  form  of  a  paste  along  with 

gutta  percha  „^„-_.i,.g  inventions  is  to  expose  the  gutta  percha  to  the  deutoxide 

of i^tr  or  cSoride'oT^i^^^^  andViling  hit,  anS  then  washed  with  ao 


GUTTA  PERCHA. 


985 


alkaline  solution  or  mere  water.  Gutta  percha  thus  treated  by  the  action  of  nitrous  gas, 
as  it  is  evolved  from  nitric  acid  and  copper,  iron,  or  zinc,  becomes  exceedingly  smooth, 
and  of  a  lustre  approaching  to  metallic ;  so  also  does  common  unsulphured  caoutch(.uc. 
It  is  thus  also  freed  from  all  stickiness:  while  the  sulphured  acquires  under  thi* 
treatment  the  d^wny  softness  of  velvet.  Chloride  of  zinc  and  nitrous  gas  remove 
the  smell  of  vulcanized  caoutchouc  in  a  great  measure,  especially  if  it  be  afterwards 

Other  new  inventions  are  practised  by  masticating  either  gutta  percha.  caoutchouc,  or 
jintawan,  in  the  proportion  of  6  parts  with  1  of  chloride  of  zinc;  all  which  compounds 
may  be  afterwards  sulphured.  A  further  modification  consists  in  producing  a  spongy 
gutta  percha,  caoutchouc,  or  jintawan.  for  stuffing  sofas,  <fec.  48  parts  of  one  of  these, 
moistened  with  oil  of  turpentine,  coal  naphtha,  bisulphuret  of  carbon,  or  other  proper 
solvent,  6  parts  of  hydrosulphuret  of  lime,  sulphuret  of  antimony,  or  other  analogous 
Bulphuret,  1 0  parts  of  carbonate  of  ammonia,  carbonate  of  lime,  or  other  substance  that 
is  either  volatile  or  capable  of  yielding  a  volatile  product,  and  1  part  of  sulphur.  He 
mixes  these  materials  together  in  a  masticator,  and  then  subjects  them  to  a  high  degree 
of  heat,  observing  the  same  conditions  which  are  stated  in  the  former  description,  except 
only  that  the  heat  may  be  pushed  with  advantage  several  degrees  higher^  say  from  260° 
to  300°  Fahr. 

Articles  are  manufactured  of  ordinary  gutta  percha,  caoutchouc,  or  jintawan.  such  as 
single  and  double  texture  waterproof  fabrics,  boots,  galoshes,  belts,  bandages,  trousers' 
and  other  straps,  capes,  life-preservers,  tubes,  knapsacks,  caps,  cups,  and  other  vessels  of 
capacity,  hammer  cloths,  cotton  spinning  rollers,  backs  of  cards  for  carding  wool,  piano- 
forte hammers,  paper  holders,  springs,  trusses.  <fec.  By  taking  the  gutta  percha,  caout- 
chouc, or  jintawan,  after  it  has  been  sulphured,  and  brushing  it  with  a  solution  of  resin 
in  boiling  oil  (linseed  ?).  placing  it  in  a  chamber  heated  to  from  75°  to  100°  Fahr..  and 
afterwards  polisliing  it  by  the  means  usually  employed  by  the  japanners,  it  acquires  the 
lustre  of  japanned  wares. 

Mr.  Hancock  has  also  contrived  a  machine  for  cutting  gutta  percha  into  strips  or  ribands, 
thread,  or  cord  of  any  required  shape.  It  consists  of  two  grooved  rollers  of  iron  or 
Bteel,  mounted  in  a  suitable  framework.  The  grooves  of  each  roller  are  semicircular, 
and  the  projecting  divisions  between  the  grooves  are  made  with  knife  edges,  so  as  to 
divide  readily  any  sheet  or  mass  of  gutta  percha  presented  to  them.  The  under  roller 
is  flanged  at  both  ends,  and  the  upper  roller  is 'made  to  fit  inside  of  these  flanges,  in 
order  to  keep  the  cutting  edges  from  shifting  or  being  damaged  To  cut  thin  sheets  of 
gutta  percha  with  this  machine  into  strips  or  ribands,  the  material  is  passed  through  it  in 
a  cold  state,  and  only  the  cutting  edges  are  brought  into  operation.  To  make  round  cord 
or  thread  by  means  of  it,  either  a  sheet  of  gutta  percha  of  a  thickness  equal  to  the 
diameter  of  the  holes  formed  by  the  grooves,  and  at  a  temperature  of  200°  Fahr.  (pro- 
duced by  supplying  it  from  a  feeding-chamber  heated  to  that  degree)  is  passed  through 
the  machine,  and  the  threads  or  cords  are  received  in  a  tank  of  cold  water,  from  which 
they  are  led  away  to  be  wound  on  reels  or  drums ;  or  the  gutta  percha  is  employed  in  a 
plastic  state,  and  passed  under  a  gauge  before  it  enters  the  machine.  If  it  be  desired  to 
produce  a  cord  of  a  semicircular  form  in  the  transverse  section,  a  plane  roUer  is  substi- 
tuted for  the  lower  grooved  roller ;  or  should  cord  of  a  square,  triangular,  or  hexangular. 
or  any  otlier  form  be  required,  the  two  rollers  must  be  shaped  to  suit. — Newton's  Journal, 
XXXV.  96. 

Gutta  Percha  Letter*.  Gutta  Percha  has  been  patented  for  making  letters  for  shop 
signs  by  Mr.  Moore,  Barrister. 

Outta  Percha  Tubes  ;  strength  of.  A  series  of  interesting  experiments  have  just  been 
concluded  at  the  Birmingham  Waterworks,  relative  to  the  strength  of  Gutta  Percha 
Tubing,  with  a  view  to  its  applicability  for  the  conveyance  of  water.  Tlie  experiments 
were  made  (under  the  direction  of  Henry  Rofe,  Esq.,  engineer.)  upon  tube  f  of  an  inch 
diamciter,  and  one  eighth  of  gutta  percha.  These  were  attached  to  the  iron  main,  and 
subjected  for  two  months  to  a  pressure  of  200  feet  head  of  water,  without  being  in  the 
slightest  degree  deteriorated.  In  order  to  ascertain  if  possible  the  maximum  strength  of 
the  tubes,  they  were  connected  with  the  Water  Company's  hydraulic  proving  pump,  the 
regular  load  of  which  is  250  lbs.  on  the  square  inch.  At  this  point  the  tubes  were  un- 
affected, and  the  pump  was  worked  up  to  337  lbs.,  but  to  the  astonishment  of  every  one 
the  tubes  still  remained  perfect.  It  was  then  proposed  to  work  the  pump  up  to  600  lbs., 
but  it  was  found  that  the  lever  of  the  valve  would  not  bear  this  weight.  The  utmost 
power  of  the  hydraulic  pump  could  not  break  the  tubes. 

Tlie  gutta  percha  being  somewhat  elastic,  allowed  the  tubes  to  become  slightly  ex- 
panded by  the  extraordinary  pressure  which  was  applied,  but  on  its  withdrawal  they  re- 
sumed their  former  size. 

Gutta  Percha  Tubing.  Tliis  tubing  is  such  an  extraordinary  conductor  of  sound,  that 
its  value,  not  only  to  deaf  persons,  but  to  the  public  generally,  will  speedily  be  appre- 


«  • 


986 


GUTTA  PERCHA. 


I|l| 


i 


ciated.  It  has  already  been  fitted  up  in  dwelling  houses,  in  lieu  of  bells  ; — as  speaking 
tubes  for  giving  and  receiving  messages  in  mines,  railway  stations,  prisons,  workhouses, 
hotels,  and  all  large  establishments,  it  is  invaluable. 

GuTTA  VEVicnx— -its  Properties,  Analysis,  Elementary  Composition  and  Applications, 
by  Af.  Payen.  Without  possessing  any  exact  information  regarding  the  extraction  of  the 
substance  which  comes  to  us  from  the  Eastern  Archipelago  under  the  name  of  gutta 
percha,  we  know  that  this  substance  is  contained  in  the  descending  sap  of  the  Isonandra 
Gutta,  Hooker,  belonging  to  the  natural  order  Sapotacece.  This  tree  attains  a  great  size, 
being  sometimes  as  much  as  a  yard  in  diameter,  and  60  or  70  feet  in  height ;  its  soft  and 
fibrous  wood  is  useless  for  industrial  purposes;  its  fruit  furnishes  a  fatty  oil. 

It  is  said  that  a  tree,  when  cut  down,  will  yield  18  kilogrammes  of  gutta  percha  or 
solid  gum.  The  juices,  dried  in  thin  strata  la'id  one  upon  another,  form  irregular  masses 
of  greater  or  less  thickness,  of  a  reddish  or  grayish  colour,  of  which  a  gradually  increasing 
quantity  has  been  annually  imported  into  Europe  and  America  since  1845. 

During  many  years  the  natives  of  the  countries  where  it  is  produced  have  employed  it 
almost  solely  in  the  formation  of  handles  for  axes,  which  possess  when  cold  a  certain 
degree  of  flexibility  with  great  toughness.  At  present,  the  gutta  percha  is  purified  by 
rasping  it  in  cold  water,  which  removes  the  greater  part  of  the  soluble  organic  matter  and 
salts,  and  also  facilitates  the  separation  of  any  portions  of  wood  or  earthy  matters.  The 
purification  is  completed  by  means  of  warm  water  in  several  basins ;  the  gutta  percha  is 
afterwards  dried,  and  formed  into  a  pasty  mass  by  heating  it  to  about  230°  F.  in  a  vessel 
"with  a  steam  jacket. 

The  gutta  percha  thus  prepared  becomes  sufiiciently  soft  to  be  readily  joined,  stretched 
out  into  sheets  or  straps  of  any  thickness,  drawn  into  tubes  of  various  diameters,  and 
moulded  into  any  form,  whilst,  on  being  slowly  cooled,  it  acquires  great  tenacity  and 
solidity.     It  is  necessary,  however,  to  remark,  that  the  presence  of  a  small  quantity  of 
water  is  sufiicient  to  prevent  the  adhesion  of  its  parts. 

Properties  of  common  Gutta  Percha. — The  gutta  percha  thus  purified  for  manufactur- 
ing purposes,  is  of  a  reddish-brown  colour ;  it  readily  becomes  electrical  by  friction  and  is 
a  bad  conductor  of  both  electricity  and  heat.  At  the  ordinary  temperature  of  our  climate, 
say  from  32j*  to  77°,  it  possesses  about  as  much  tenacity  as  thick  leather,  with  rather  less 
flexibility;  it  softens  and  becomes  sensibly  doughy  towards  120°,  although  still  very 
tough.  Its  ductility  is  such,  at  a  temperature  of  from  110°  to  241°,  that  it  is  readily 
extended  into  thin  sheets,  or  drawn  mto  threads  or  tubes  ;  its  flexibility  and  ductility 
dinnnish  as  the  temperature  becomes  lower.  It  does  not  possess  at  any  temperature  the 
peculiar  elastic  extensibility  which  characterizes  caoutchouc.  Exposed  for  an  hour  to  a 
temperature  of  14°,  its  flexibility  is  slightly  diminished. 

In  its  various  forms,  gutta  percha  possesses  a  peculiar  porosity,  as  may  be  shown  in 
the  following  manner  : — A  drop  of  its  solution  in  sulphuret  of  carbon  is  to  be  placed  on 
a  glass  slip;  the  spontaneous  evaporation  soon  reduces  this  solution  to  a  whitish  plate; 
if  it  be  then  examined  with  the  microscope,  the  numerous  cavities  with  which  it  is  pierced 
may  be  distinctly  perceived.  Tliese  cavities  may  be  rendered  still  more  visible  by  means 
of  a  drop  of  water  ;  the  liquid  gradually  insinuates  itself,  the  mass  appears  more  opake, 
and  by  means  of  the  microscope  the  cavities  are  seen  to  be  enlarged. 

Similar  results  are  obtained  by  keeping  immersed  in  water  for  a  considerable  time 
thin  transparent  laminae,  obtained  by  the  evaporation  by  heat  of  a  solution  of  gutta 
percha. 

The  preceding  observations  led  me  to  think,  that  this  substance  retaining,  in  conse- 
quence of  its  porosity,  a  great  many  minute  particles  of  air,  owed  to  this  circumstance  its 
appearance  of  possessing  a  less  density  than  that  of  water,  namely  0979.  In  fact,  on 
stretching  gutta  percha  under  strong  pressure,  and  immediately  cutting  the  strips  thus 
produced  into  very  small  pieces  under  water,  the  greater  part  of  the  fragments  fell  to  the 
bottom  of  the  vessel — some  immediately,  others  after  absorbing  a  certain  quantity  of 
water.  The  same  result  was  also  obtained  by  keeping  very  thin  leaves  of  gutta  percha, 
prepared  by  different  methods,  immersed  for  a  month  in  water  deprived  of  air ;  their  pore« 
becoming  gradually  filled  with  the  liquid,  they  became  heavier  than  the  water,  and  then 
ceased  to  float.  Gutta  percha  is  also  heavier  in  proportion  to  the  length  of  time  it  baa 
been  exposed  to  the  air,  particularly  in  thin  leaves. 

The  porous  structure  of  gutta  percha  becomes  changed  into  a  fibrous  texture  w  hen  it  is 
drawn  out  so  as  to  double  its  length ;  then  retaining  but  little  extensibility,  it  supports, 
without  breaking,  the  action  of  a  force  equal  to  double  that  required  for  its  elongation  ia 
the  first  instance. 

Common  gutta  percha  resists  cold  water,  damp,  and  also  the  various  influences  which 
excite  fermentation  ;  but  it  can  be  softened,  and  experience  a  sort  of  superficial  doughy 
fusion  by  the  action  of  the  solar  rays  in  summer. 

It  is  not  attacked  by  alkaline  solutions,  even  when  caustic  and  concentrated ;  am- 
monia,  saline   solutions,  water   containing  carbonic  acid,   the    various  vegetable   and 


GUTTA  PERCHA. 


987 


mmeral  acids,  do  not  act  upon  it;  alcoholic  liquors  (wines,  beer,  Ac.)  do  not  touch  it  • 
even  brandy  scarcely  dissolves  a  trace  of  it.  Olive-oil  does  not  appear  to  attack  gutta 
percha  when  cold;  when  hot,  it  dissolves  a  small  portion  of  it,  which  is  aeain  precipi- 
tated on  cooling.  &       r       f 

Sulphuric  acid  with  one  equiv.  of  water  colours  it  brown,  and  disintegrates  it  with  a 
sensible  evolution  of  sulphurous  acid. 

Muriatic  acid,  in  its  saturated  solution  in  water  at  a  temperature  of  68°  F.,  attacks 
putta  percha  slowly,  and  gives  it  a  more  or  less  deep  brown  colour,  at  length  rendering 

Monohydrated  nitric  acid  attacks  it  rapidly,  with  effervescence  and  an  abundant  evo- 
lution  of  fumes  of  hyponitrous  acid ;  the  substance  is  decomposed,  and  coloured  of  a 
brownish  orange  red ;  it  becomes  doughy,  and  afterwards  solidifies  by  degrees  and  re- 
mams  friable.  •'       ° 

In  the  cold,  and  even  by  heat,  only  a  part  of  the  gutta  percha  (01 5  to  022)  is  dis- 
solved by  anhydrous  alcohol  or  ether.  Benzine  and  spirits  of  turpentine  dissolve  it 
partially  when  cold  but  nearly  completely  by  heat.  Sulphuret  of  carbon  and  chloroform 
dissolve  gutta  percha  when  cold ;  the  solutions  may  be  filtered  beneath  a  bell  glass  to 
prevent  evaporation;  the  filter  retains  the  foreign  matters  of  a  reddish-brown  colour 
Whilst  the  solution  passes  perfectly  clear  and  almost  colourless.  The  filtered  liquid 
exposed  to  the  air  in  a  saucer,  allows  the  solvent  to  escape,  and  deposits  the  white  gutta 
percha  m  a  plate  of  greater  or  less  thickness,  which  shrinks  gi-adually  in  proportion  to 
the  evaporation  of  the  liquid.  J       f    i^ 

Except  the  colour,  which  has  disappeared,  the  gutta  percha  offers  then  the  characters 
and  properties  mentioned  above  as  belonging  to  the  commercial  substance.  Submitted 
to  a  gradually-raised  temperature,  it  softens  and  melts,  and  may  be  made  to  boil  with- 

l"n  I'^'^'^T/"^-  V^"''^^^  f"^''"!''  ^^^  transparent  fluid  gives  abundant  vapours  which  are 
condensable  mto  a  nearly  colourless  oily  liquid.  The  portions  last  distilled  have  a 
browni.h-orange  colour,  and  a  thin  layer  of  carbonaceous  deposit  remains  adherent  to 
the  sides  of  the  vessel. 

Analysis— We  have  said  above  that  alcohol  and  ether  can  dissolve  only  a  portion  of 
gutta  percha  ;  this  is  because  that  substance  consists,  in  fact,  of  three  proximate  princi- 
ples^ the  separa  ion  of  which  has  required  very  delicate  observation,  although  they  are 
very  clearly  distinguished  by  several  of  their  properties  *  ^ 

When  gutta  percha  in  thin  leaves  is  brought  into  contact,  in  a  close  vessel,  with 
15  to  20  vols  of  cold  anhydrous  alcohol,  and  the  temperature  raised  slowly  by  means  of 
the  water-bath  to  the  point  of  ebullition  (172°  F.),  and  kept  at  this  pit  durin-.  se- 
veral hours,  the  liquid.  If  filtered  whilst  boiling  and  left  in  a  closed  flask,  will  af  t be 
«?  tl?!i^rT-  \f  ^^"""'v'  ^^^'"  ^deposit  on  tlie  sides  of  the  vessel  and  on  the  surface 
of  the  solution  white  opaline  granules,  distant  from  one  another,  but  some  of  them  in 
groups;  their  size  will  gradually  increase  for  some  days.  These  granules,  carefully 
examined  under  the  microscope,  will  be  found  to  have  the  form  of  spherules  truncated 
by  the  sides  of  the  vessel.  Their  surface  is  either  smooth  or  bristling,  with  very  smal 
ransparent,  elongated,  lamellar  crystals.  Some  superficial  fissures  appear  to  indicate 
white    eTlide"      ^""^  *  '°'*  ""^  transparent  yellow  kernel  covered  with  a 

Such  is  really  their  singular  crystalline  structure,  of  which  perhaps  no  other  example 
IS  known.  In  fact,  cold  anhydrous  alcohol  dissolves  the  whole  of  the  yellow  subjacent 
spheroidal  substance,  while  the  superficial  pellicle,  in  the  interior  of  which  the  alcohol 
has  substituted  itself  for  the  solid  globule.  Appear  whiter  and  less  tranlparent 

1  he  alcoholic  solution  which  has  been  for  some  days  depositing  this  complex  sphe- 
roidal crystallization  can  again  take  up  by  heat  a  portion  of  the  two  proximate  pHn- 
ciples  remaining  in  the  substance,  allowiug  a  fresh  quantity  to  crystallize  en  c.>olin<. 
The  extraction  is  comp  eted  by  returning  the  boiling  alcohol  several  times  upon  tlfe 
gutta  percha  until  it  no  longer  dissolves  anything.  ^ 

The  solid  substance  which  has  resisted  the  action  of  the  solvent,  possesses,  with  some 
modifications  the  principal  properties  of  crude  gutta  percha;  we  shall  here  call  it  pnr- 
gutta  or  gutta  As  to  the  two  other  organic  principles,  one  is  a  yellow  resin  whicli  is 
much  more  soluble  in  cold  alcohol  than  the  other,  xhe  white  crystallLZn 

By  taking  advantage  of  these  different  degrees  of  solubility,  we  are  enabled  with  time 
and  patience,  to  effect  the  complete  purification  of  these  three  principS.     ThT  ei!ra 
r"r^  i"""  be  effected  by  treating  finely-divided  gutta  percha  with  cold  ether,  ^Zch 
dissolves  the  mixture  of  the  two  resins  more  abundantly  than  alcohol;  they  are  after 
wards  separated  from  one  another  by  the  same  treatment  already  descHbed  for  alcohol 

rhe  tendency  of  the  white  resin  to  form  itself  into  groups  of  radiated  lamella  is  ma- 
nifested in  a  rather  remarkable  circumstance,  vliich  \t  is  easy  to  reproduce.  Nar^t 
gI'^vITx  ^71^'"  ^  ^'  "°^<l"^5nted  >vith  the  rosearchos  of  M.  Arppe  on  this  subject    See  Chem. 


I 


988 


GUTTA  PERCHA 


I 


I 


ribbons  cut  from  a  thin  leaf  of  ordinary  giitta  percba  are  to  be  placed  in  a  tube,  and 
immersed  in  anhydrous  alcohol.  The  tube  is  then  closed,  and  left  for  twenty  or  thirty 
days,  when  a  few  whitish  points  appear  here  and  there  on  the  ribbons,  and  afterwards  on 
the  sides  of  the  tube.  These  points,  which  become  gradually  larger,  are  formed  of  crys- 
talline tufts  of  the  white  resin.  Thus  this  proximate  principle  is  separated  directly,  and 
in  the  cold,  even  when  the  atmospheric  temperature  is  gradually  rising,  for  instance 
during  the  spring  or  early  summer. 

The  crystalline  white  resin,  when  completely  purified  by  washings  with  alcohol,  and 
then  redissolved  in  anhydrous  akohol,  is  deposited  by  slow  spontaneous  evaporation  in 
the  air,  in  radiated  lamellar  crystals,  forming  sometimes  symmetrical  tufts  arranged  in 
stars,  and  then  presenting  the  appearance  of  a  sort  of  eflflore'scence. 

Distinctive  Characters  and  Properties  of  the  Three  Proximate  Principles  which  consti- 
tute common  Gutta  Percha.—The  most  abundant  of  these  three  principles,  forming  at 
least  from  15  to  82  per  cent,  of  the  whole  mass,  is  the  pure  gutta,  which  presents  the 
principal  properties  of  the  commercial  substance ;  it  is  white,  transparent  at  a  tempera- 
ture of  212°  F.,  when  all  its  parts  are  melted  together;  opake  or  semi-transpareut  when 
cold,  from  its  then  acquiring  a  structure  which  causes  the  interposition  of  air,  or  of  a 
licjuid  possessing  a  different  refraction  from  its  own.  Tliis  stnicture  appears  still  more 
distinct  than  in  the  natural  substance  containing  all  three  principles. 

In  thin  sheets,  and  at  a  temperature  of  50°  to  68°  R,  it  is  supple,  tough,  extensible  but 
not  very  elastic.  At  112°  R,  it  softens  and  turns  back  upon  itself,  and  becomes  more  and 
more  adhesive  and  translucent  in  proportion  to  the  elevation  of  temperature,  undergoing; 
a  sort  of  doughy  fusion,  which  becomes  more  distinct  towards  212°  to  230°.  Heated 
beyond  this  point,  it  melts,  boils  and  distils,  furnishing  a  pyrogenous  oil  and  carburetted 
gases. 

Pure  gutta,  like  the  other  two  proximate  principjes,  is  quickly  rendered  electrical  by 
friction,  and  is  a  bad  conductor  of  heat ;  it  generally  floats  on  water  but  sinks  to  the 
bottom  as  soon  as  its  pores  are  filled  with  this  liquid.  It  is  insoluble  in  alcohol  and 
ether,  almost  completely  insoluble  in  benzine  at  32°  R,  it  is  soluble  at  77°,  and  becomes 
more  and  more  so  in  proportion  as  the  temperature  is  raised.  The  saturated  solution  at 
86°  forms  itself  into  a  semi-transparent  mass  when  cooled  below  32° ;  alcohol  precipitates 
the  gutta  from  its  solution  in  benzine. 

At  32°,  spirits  of  turpentine  dissolves  very  like  gutta,  whilst  it  disintegrates  and  dia* 
solves  it  readily  when  hot. 

Chloroform  and  sulphuret  of  carbon  dissolve  the  gutta  in  the  cold. 

After  the  extraction  by  means  of  ether  of  the  two  resins  interposed  in  the  thin  leaves 
of  white  gutta  percha,  leaving  the  last  portion  of  ether  with  which  they  were  impregnated 
to  evaporate  in  the  open  air,  these  leaves,  enclosed  in  a  flask,  experienced,  after  remain- 
ing there  for  two  months  at  a  temperature  of  from  68°  to  82°  R,  an  alteration  which 
appeared  to  depend  on  their  porosity,  the  action  of  the  air,  and  perhaps  the  ether 
retained  in  their  pores.  However  it  be,  these  leaves  had  then  acquired  new  properties; 
the}'  were  brittle ;  exhaled  a  very  distinct  sharp  odour ;  brought  into  contact  with  an 
excess  of  anhydrous  ether,  they  were  partially  dissolved ;  the  soluble  portion,  obtained 
by  the  evaporation  of  the  etherand  desiccation  at  194°  F.,  was  glutinous  and  translucent ; 
it  became  opake  and  hard  by  cooling  down  to  14°  F. 

Sulphuret  of  carbon,  renewed  three  times  in  six  days,  and  evaporated  each  time  after 
two  days'  contact,  left  as  residue  a  white  flexible  leaf  The  portion  not  dissolved,  swelled 
and  transparent,  did  not  appear  to  undergo  any  change  when  left  in  sulphuret  of  carbon 
for  ten  days. 

This  kind  of  spontaneous  transformation  would  perhaps  become  complete  if  more 
prolonged;  its  study  will  require  much  time;  it  will  perhaps  put  us  in  the  way  of  ascer- 
taining the  causes  of  certain  changes  observed  in  some  small  objects  formed  of  gutta 
percha.  I  have  already  been  able  to  ascertain,  that  thin  leaves,  exposed  for  eight  con- 
secutive days  to  the  action  of  the  sun  in  moist  air,  were  discoloured,  and  that  their  sub- 
stance had  become  in  great  part  soluble  in  ether. 

Monohydrated  sulphuric  acid  disintegrates,  and  communicates  a  brown  colour  to  the 

f)ure  gutta,  with  evolution  of  sulphurous  acid;  after  eight  days'  contact,  the  deep  brown 
iquid,  on  dilution  with  water,  becomes  turbid,  and  furnishes  a  brown  flocculent  precipi- 
tate.  Nitric  acid,  with  a  single  equivalent  of  water,  attacks  the  pure  gutta  with  a  lively 
effervescence,  and  the  evolution  of  orange  vapours  of  hyponitrous  acid.  Muriatic  acid,  in 
its  saturated  solution,  slowly  attacks  the  thin  leaves  of  gutta,  giving  them  a  deep  brown 
colour ;  at  the  end  of  eight  days  it  becomes  friable.  The  reaction  of  muriatic  acid  estab- 
lishes an  additional  distinctive  character  between  this  proximate  principle  and  the  two 
others. 

Crystalline  White  Resin. — Obtained  pure  by  means  of  the  operations  above  described; 
it  presents  itself  as  a  light  pulverulent  mass,  apparently  opake,  which  under  the 
microscope  exhibits  the  transparent  lamellar  crystals.    From  82°  to  212°  F  it  does  not 


GYr;SU.\I. 


989 


experience  any  sensible  change;  its  fusion  commences  at  320*>;  at  347°  to  356°  it 
acquires  an  oleiform  fluidity  and  complete  transparency,  without  any  noticeable  colour ; 
It  solidifies  on  cooling,  shrmks,  which  causes  it  to  split,  and  remains  transparent  and  a 
little  heavier  than  water. 

The  crystallized  resin  is  very  soluble  in  spirits  of  turpentine,  in  benzine,  sulphuret  of 
carbon,  ether  and  chloroform ;  on  the  spontaneous  evaporation  of  the  two  last  solvents. 
It  crystallizes  in  long,  narrow,  thin,  pearly  laminae,  forming  separate  groups  radiating 
from  common  centres.  o      *-  o      r  o 

Anhydrous  alcohol  dissolves  it  pretty  readily  at  the  temperature  of  167°  F.:  on 
cooling,  groups  of  crystals  separate,  which  increase  during  several  days  •  the  cold  solu- 
tion, decanted  after  crystallization,  and  left  to  spontaneous  evaporation  yields  similar 
crops  of  more  voluminous  lamellae.  ' 

These  crystals  are  not  attacked  or  readily  moistened  by  either  cold  or  boiling  water 
as  18  also  the  case  with  hot  or  cold  caustic  alkaline  solutions,  ammonia,  and  the  various 
dilute  acids.  Monohydrated  sulphuric  and  nitric  acids  attack  it  rapidly  producing 
similar  phenomena  to  those  observed  in  their  action  upon  pure  gutta.  Muriatic  aci<i 
on  the  contrary,  does  not  act  upon  the  white  resin ;  in  several  of  these  characters  it  ap- 
proaches to  the  breane  extracted  by  M.  Scribe  from  the  resin  of  Icica.*  It  would  be 
werl  to  submit  these  two  principles  to  a  comparative  study. 

^  Yellou}  Resin.— Hhxa  amorphous  transparent  resin  of  a  lemon  or  orange  colour  accord- 
i°ol  ^  '^-^  thickness,  IS  a  little  heavier  than  water,  solid,  and  even  hard  and  brittle,  at 
fiooo'  if  ^•■^^^^"y  becfiraes  more  flexible  in  proportion  as  the  temperature  is  raise<i; 
at  122  R  It  becomes  pasty;  it  does  not  become  completely  fluid  below  212°  to  230° 
Heated  beyond  this  point,  it  boils,  but  then  gradually  undergoes  considerable  alteration, 
becomes  brown,  and  evolves  acid  fumes  and  carburets  of  hydrogen 

This  resin  strongly  retains  the  alcohol  in  which  it  has  been  dissolved ;  it  is  separated 
from  It  by  heating  in  vacuo  to  212''  R  until  bubbling  entirely  ceases 

It  IS  soluble  m  the  cold  in  alcohol,  ether,  benzine,  essential  oil  or  turpentine,  sul- 
phuret of  carbon  and  chloroform ;  all  these  liquids,  when  evaporated,  leavfas  residue 
the  amorphous  resin. 

Dilute  acids,  concentrated  alkaline  solutions,  and  ammonia  do  not  attack  the  yellow 
resin.  Monohydrated  sulphuric  and  nitric  acids  act  upon  it  rapidly,  producing  pheno- 
mena analogous  to  those  exhibited  with  the  other  two^  principles.     Muriatic  adJeven 

oL'r ir'Ttr'''^"''""-^lf  ^°  ^-  ^  ^^'^^"^  ^*^*i««  "P«"  it-  ^But  the  most^  remarkable 
diarac  e  of  this  resin  is  the  power  of  forming,  under  the  circumstances  already  in- 
dicated, those  globose  crystals  covered  with  a  white  pellicle  of  another  resin,  and  offering 
m  their  complex  form  the  appearance  of  opaline  spherules  ""«""& 

We  see  thus  that  the  gutta  perCha  as  it  occurs  in  commerce,  consists  of  three  distinctly 
characterized  proximate  principles,  besides  some  other  matters  in  small  quantities ;  the 
most  abundant  of  these  principles  possesses  the  properties  of  the  origin^  substance  I 
give  It  the  name  of  pure  gutta  or  putta  ;  the  two  other  principles  are  neutral  resins 

In  order  to  recal  their  characteristic  properties,  I  will  give  the  name  of  crystalhane  or 
f  bane  to  that  which  is  obtained  without  difficulty  in  white  crystals  ;  and  that  of  A^vUe 
to  the  third,  which  IS  yellow,  and  bec<,mes  sensibly  fluid  at  a  low  temperature    ^•^'^'"'' 

The  commercial  varieties  which  I  have  examined  have  given  me  the  following  pro- 

Gutta  .  -  .  .    .75  g, 

Albane  -  .  -  -     16  14 

Fluavile  -  -  -  .       g  ^ 

^  GYPSUM  Sulphate  of  Lime,  Alabaster,  or  Paris  Plaster.  This  substance  is  found 
m  three  geological  positions  in  the  crust  of  the  earth;  among  transiUon  roc^3  in  Se 
red  marl  formation  ;  and  above  the  chalk,  in  the  tertiary  beds.  ""'*'"""  '^^^»»  ^  ^^^ 
1.  The  alpine  gypsums  are  ranged  by  M.  Brochant  among  the  transition  class  and 
are  characterized  by  the  presence  of  anthracite  or  stone  coal ;  some  of  em  afe  thUe 
and  pure  others  gray  or  yellowish,  and  mixed  with  mica,  tali,  steatite  E  oxide  of 
iron  pyrites,  compact  carbonate  of  lime,  sulphur,  and  common 'sail  ikampLo^^^ 
Realities  are  found  in  the  gypsum  of  Val-Carcaria  at  the  foot  of  SdntGothard  that  of 

S;^^^:^s  1^4::  t^^  ^^  ^^^  -^^^^  °^  ^^— i>  and  \r^%:i 

ancient.     JMear  JNorthwick  the  red  marl  beds  above  the  great  deposit  of  rock  salt  are 
irregularly  intersected  wih  gypsum,  in  numerous  lamina  or  plateT  At  Newbtjin  [n 
^nT^'i;lirp  'k1^  t.^^?Ti  ^?i  '"  red  argillaceous  marl,  between^wo  strala  of  3one 
and  a  mile  south  of  Whitehaven,  the  subterraneous  workings  for  the  aUbas^  extend 

♦  Chem.  Qaz.  vol  Ir.  p.  151. 


990 


GYPSUM. 


HADE. 


991 


»» 


SO  yards  in  a  direct  line ;  with  two  or  three  lateral  branches  extending  about  10  yards., 
at  whose  extremities  are  lafge  spaces  where  the  gypsum  is  blasted  with  gunpowder.  It 
is  generally  compact,  forming  a  regular  and  conformable  bed,  with  crystals  of  selenite 
(cr3rstallized  gypsum)  in  drusy  cavities.  Gypsum  occuis  in  the  red  marl  in  the  isle  of 
Axholme,  and  various  other  places  in  Nottinghamshire.  In  Derbyshire  some  consider- 
able deposits  have  been  found  in  the  same  red  sandstone,  several  of  which  are  mined, 
as  at  Chellaston  hill,  which  would  exhibit  a  naked  and  water- worn  rock  of  gypsum, 
were  it  not  for  a  covering  of  alluvial  clay.  It  appears  in  general  to  present  itself 
chiefly  in  particular  patches,  occasioning  a  sudden  rise,  or  an  insulated  hill,  by  the 
additional  thickness  which  it  gives  to  the  stratum  of  the  red  ground  in  these  places. 
The  principal  demand  for  the  pure  white  gypsum,  or  that  faintly  streaked  with  reo,  is  by 
the  potters  in  Staffordshire,  who  form  their  moulds  with  the  calcined  powder  which  it 
affords ;  only  particularly  fine  blocks  are  selected  for  making  alabaster  ornaments  on 
the  turning  lathe.  In  one  of  the  salt  pits  near  Droitwich,  the  strata  sunk  through  were 
vegetable  mould,  3  feet ;  red  marl,  35  feet ;  gypsum,  40  feet ;  a  river  of  brine,  22  inches ; 
gypsum,  75  feet ;  a  rock  of  salt,  bored  into  only  five,  but  probably  extending  much 
deeper.  On  the  Welsh  side  of  the  Bristol  Channel,  gypsum  occurs  in  the  red  marl 
cliffs  of  Glamor«janshire,  from  Pennarth  to  Lavernock.  No  organic  remains  or  metallic 
minerals  have  hitherto  been  found  in  the  gypsum  of  this  formation. 

3.  The  most  interesting  gypsums  in  a  general  point  of  view,  are  certainly  the  tertiary, 
or  those  of  the  plains,  or  hills  of  comparatively  modern  formation.  They  are  characterized 
by  the  presence  of  fossil  bones  of  extinct  animals,  both  viammi/era  and  birds,  by  shells, 
and  a  large  proportion  of  carbonate  of  lime,  which  gives  them  the  property  of  effer- 
vescing with  acids,  and  the  title  of  limestone  gypsums.  Such  are  the  gypsums  of  the 
environs  of  Paris,  as  at  the  heights  of  Montmartre,  which  contain  crystallized  sulphate 
of  lime  in  many  forms,  but  most  commonly  the  lenticular  and  lance-shaped. 

Sulphate  of  lime  occurs  either  as  a  dense  compound  without  water,  and  is  called 
anhydrite  from  that  circumstance ;  or  with  combined  water,  which  is  its  most  ordinary 
state.  Of  the  latter  there  are  6  sub-species;  sparry  gypsum  or  selenite  in  a  variety  of 
crystalline  forms ;  the  foliated  granular ;  the  compact ;  the  fibrous ;  the  scaly  foliated ; 
the  earthy. 

The  prevailing  colour  is  white,  with  various  shades  of  gray,  blue,  red,  and  yellow. 
More  or  less  translucent.  Soft,  sectile,  yielding  to  the  nail.  Specific  gravity  2'2. 
Water  dissolves  about  one  five-hundredth  part  of  its  weight  of  gypsum,  and  acquires 
the  quality  of  hardness,  with  the  characteristic  selenitic  taste.  When  exposed  on  red 
hot  coals,  it  decrepitates,  becomes  white,  and  splits  into  a  great  many  brittle  plates.  At 
the  heat  of  a  baker's  oven,  or  about  400°  Fahr.,  the  combined  water  of  gypsum  es- 
capes with  a  species  of  ebullition ;  at  a  higher  temperature  the  particles  get  indurated. 
When  rightly  calcined  and  pulverized,  gypsum  is  mixed  with  water  to  the  consistence 
of  cream,  and  poured  into  moulds  by  the  manufacturers  of  stucco  ornaments  and 
statues.  A  species  of  rapid  crystallization  ensues,  and  the  thin  paste  soon  acquires  a 
solid  consistence,  which  is  increased  by  drying  the  figure  in  proper  stoves.  During, 
the  consolidation  of  the  plaster,  its  volume  expands  into  the  finest  lines  of  the  mould, 
so  as  to  give  a  sharp  and  faithful  impression. 

The  plaster  stone  of  the  Paris  basin  contains  about  12  per  cent,  of  carbonate  of  lime. 
This  body,  ground  and  mixed  with  water,  forms  an  adhesive  mortar  much  used  in 
building,  as  it  fixes  very  speedily.  Works  executed  with  pure  gypsum  never  become  so 
hard  as  those  made  with  the  calcareous  kind  :  and  hence  it  might  be  proper  to  add  a 
certain  portion  of  white  slaked  lime  to  our  calcined  gypsum,  in  order  to  give  the  stucco 
this  valuable  property.  Coloured  stuccos  of  great  solidity  are  maae  by  adding  to  a 
clear  solution  of  glue,  any  desired  colouring  tincture,  and  mixing  in  the  proper  quan- 
tity of  the  calcined  calcareous  gypsum. 

The  compact,  fine-grained  gypseous  alabaster  is  often  cut  into  various  ornamental 
figures,  such  as  vases,  statuary  groups,  <fec.,  which  take  a  high  polish  and  look  beautiful,  but 
from  their  softness  are  easily  injured,  and  require  to  be  kept  enclosed  within  a  glass  shade. 

In  America  and  France,  the  virtues  of  gypsum  in  fertilizing  land  have  been  highly 
extolled,  but  they  have  not  been  realized  in  the  trials  made  in  this  kingdom. 

Pure  gypsum  consists  of  lime  28 ;  sulphuric  acid  40 ;  water  18 ;  which  are  the  re- 
spective weights  of  its  prime  equivalent  parts. 

M.  Gay  Lussac,  in  a  short  notice,  in  the  Annalex  de  Ckimie  for  April  1829,  on  the 
setting  of  gypsum,  says  that  the  purest  plasters  are  those  that  harden  least,  and  that  the 
addition  of  lime  is  of  no  use  towards  promoting  their  solidity,  nor  can  the  heat  proper 
for  boiling  gypsum  ever  expel  the  carbonic  acid  gas  from  the  calcareous  carbonate 
present  in  the  gypsum  of  Montmartre.  He  conceives  that  a  hard  plaster-stone  having 
lost  its  water,  will  resume  more  solidity  in  returning  to  its  first  state,  than  a  plaster- 
stone  naturally  tender  or  soft ;  and  that  it  is  the  primitive  molecular  arrangement  which 
is  regenerated.     See  Alabaster,  and  Stone  Artificial. 


H. 

HADE  signifies,  among  English  miners,  the  inclination,  or  deTiation  from  the  vertical 
of  any  mineral  vein. 

HAIR  (Cheveuy  Critiy  Fr. ;  Haary  Genn.)  is  of  all  animal  products,  the  one  least 
liable  to  spontaneous  change.  It  can  be  dissolved  in  water  only  at  a  temperature  some- 
what above  230°  F.,  in  a  Papin's  digester,  but  it  appears  to  be  partially  decomposed  by 
this  heat,  since  some  sulphureted  hydrogen  is  disengaged.  By  dry  distillation,  hair  gives 
off  several  sulphureted  gases,  while  the  residuum  contains  sulphate  of  lime,  common 
salt,  much  silica,  with  some  oxyde  of  iron  and  manganese.  It  is  a  remarkable  fact  that 
fair  hair  affords  magnesia,  instead  of  these  latter  two  oxydes.  Horse-hair  yields  about  12 
per  cent,  of  phosphate  of  lime. 

Hairs  are  tubular,  their  cavities  being  filled  with  a  fat  oil,  having  the  same  color  with 
themselves.  Hair  plunged  in  chlorine  gas,  is  immediately  decomposed  and  converted  into 
a  viscid  mass ;  but  when  immersed  in  weak  aqueous  chlorine,  it  undergoes  no  chanee, 
except  a  little  bleaching.  The  application  of  nitrate  of  mercury  to  hairy  skins  in  The 
process  of  secretage,  is  explained  under  Peltry. 

For  the  dyeing  of  horse-hair,  see  the  next  article. 

Living  hairs  are  rendered  black  by  applying  to  them,  for  a  short  time,  a  paste  made  by 
mixing  litharge,  slaked  lime,  and  bicarbonate  of  potash,  in  various  proportions,  according 
to  the  shade  of  color  desired. 

We  have  no  recent  analysis  of  hair.  Vauquelin  found  nine  different  substances  in  black 
hair ;  in  red  hair,  a  red  oil  instead  of  a  greenish-black  one. 

The  salts  of  mercury,  lead,  bismuth,  as  well  as  their  oxydes,  blacken  hair,  or  make  it 
of  a  dark  violet,  by  the  formation,  most  probably,  of  metallic  sulphurels. 

Hair  as  an  object  of  manufactures  is  of  two  kinds,  the  curly  and  the  straight.  The 
former,  which  is  short,  is  spun  into  a  cord,  and  boiled  in  this  state,  to  give  it  the  tortuous 
springy  form.  The  long  straight  hair  is  woven  into  cloth  for  sieves,  and  also  for  orna- 
mental purposes,  as  in  the  damask-hair  cloth  of  chair  bottoms.  For  this  purpose  the  hair 
may  be  dyed  in  the  following  way. 

Forty  pounds  of  tail  hair  about  26  inches  long  are  steeped  in  lime  water  during  twelve 
hours.  Then  a  bath  is  made  with  a  decoction  of  20  pounds  of  logwood,  kept  boiling  for 
three  hours,  af\er  which  time  the  fire  is  withdrawn  from  the  boiler,  and  ten  ounces  of 
copperas  are  introduced,  stirred  about,  and  the  hair  is  immersed,  having  been  washed  from 
the  lime  in  river  water.  The  hair  should  remain  in  this  cooling  bath  for  24  hours,  when 
the  operation  will  be  finished.     For  other  colors,  see  the  respective  dyes. 

The  looms  for  weaving  hair  differ  from  the  common  ones,  only  in  the  templet  and  the 
shuttle.  Two  templets  of  iron  must  be  used  to  keep  the  stuff  equably,  but  lightly 
stretched.  These  templets,  of  which  one  is  represented  in  fig.  741 ,  are  constructed  in 
the  shape  of  flat  pincers ;  the  jaws  c  c  being  furnished  with  teelh  inside.    A  screw  d, 

binds  the  jaws  together,  and  hinders  the  selvage 
from  going  inwards.  Upon  ihe  side  cross  beam 
of  the  loom,  seen  in  section  at  i,  a  bolt  is  fixed 
which  carries  a  nut  f  at  its  end,  into  which  a 
screwed  iron  rod  e  enters,  on  one  of  whose  ends 
is  the  handle  b.  The  other  extremity  of  the 
screw  E  is  adapted  by  a  washer  and  pin  to  th« 
back  of  the  pincers  at  the  point  h,  so  that  by 
^Sr"  turning  the  handle  to  the  right  or  the  left,  we 

^  draw  onwards  or  push  backwards  the  pincers 

and  the  stuff  at  pleasure.  The  warp  of  the  web  is  made  of  black  linen  yarn.  The  weft 
is  of  hair,  and  it  is  thrown  with  a  long  hooked  shuttle  ;  or  a  long  rod,  having  a  catch 
hook  at  its  end.  The  length  of  this  shuttle  is  about  3  feet ;  its  breadth  half  an  inch,  and 
its  thickness  one  sixth.  It  is  made  of  box- wood.  The  reed  is  of  polished  steel;  the 
thread  warps  are  conducted  through  it  in  the  usual  w^ay.  The  workman  passes  this 
shuttle  between  the  hairs  of  the  warp  with  one  hand,  when  the  shed  or  shuttle  way  is 
opened  by  the  treddles ;  a  child  placed  on  one  side  of  the  loom  presents  a  hair  to  the 
weaver  near  the  selvage,  who  catches  it  with  the  hook  of  his  shuttle,  and  by  drawing  it 
out  passes  it  through  the  warp.  The  hairs  are  placed  in  a  bundle  on  the  side  where  the 
child  stands,  in  a  chest  filled  with  water  to  keep  them  moist,  for  otherwise  they  would  not 
have  the  suppleness  requisite  to  form  a  web.  Each  time  that  a  hair  is  thrown  across,  the 
batten  is  driven  home  twice.  The  warp  is  dressed  with  paste  in  the  usual  way.  '■'»»- 
hair  cloth,  after  it  is  woven,  is  hot  calendered  to  give  it  lustre. 


The 


992 


HAJIDNESS. 


HARTSHORN. 


993 


HAIR  PENCILS  OR  BRUSHES  for  painting.  Two  sorts  are  made ;  those  with  coarse 
aair,  as  that  of  the  swine,  the  wild  boar,  the  dog,  &c.,  which  are  attached  usually  to  short 
wooden  rods  as  handles  ;  these  are  commonly  called  brushes ;  and  hair  pencils,  properly 
so  called,  which  are  composed  of  very  iSne  hairs,  as  of  the  minever,  the  marten,  the 
badger,  the  polecat,  &.c.  These  are  mounted  in  a  quill  when  they  are  small  or  of  mode- 
rate size,  but  when  larger  than  a  quill,  they  are  mounted  in  white-iron  tubes. 

The  most  essential  quality  of  a  good  pencil  is  to  form  a  fine  point,  so  that  all  the  hairs 
without  exception  may  be  united  when  they  are  moistened  by  laying  them  upon  the 
tongue,  or  drawing  them  through  the  lips.  When  hairs  present  the  form  of  an  elongated 
cone  in  a  pencil,  their  point  only  can  be  used.  The  whole  difficulty  consists  after  the 
hairs  are  cleansed,  in  arranging  them  together  so  that  all  their  points  may  lie  in  the  same 
horizontal  plane.  We  must  wash  the  tails  of  the  animals  whose  hairs  are  to  be  used, 
by  scouring  them  in  a  solution  of  alum  till  they  be  quite  free  from  grease,  and  then  steep- 
ing them  for  24  hours  in  luke-warm  water.  We  next  squeeze  out  the  water  by  pressing 
them  strongly  from  the  root  to  the  tip,  in  order  to  lay  the  hairs  as  smooth  as  possible. 
They  are  to  be  dried  with  pressure  in  linen  cloths,  combed  in  the  longitudinal  direction, 
with  a  very  fine-toothed  comb,  finally  wrapped  up  in  fine  linen,  and  dried.  When  per- 
fectly dry,  the  hairs  are  seized  with  pincers,  cut  across  close  to  the  skin,  and  arranged  in 
separate  heaps,  according  to  their  respective  lengths. 

Each  of  these  little  heaps  is  placed  separately,  one  after  the  other,  in  small  tin  pans 
with  flat  bottoms,  with  the  tips  of  the  hair  upwards.  On  striking  the  bottom  of  the  pan 
slightly  upon  a  table,  the  hairs  get  arranged  parallel  to  each  other,  and  their  delicate 
points  rise  more  or  less  accordmg  to  their  lengths.  The  longer  ones  are  to  be  picked  out 
and  made  into  so  many  separate  parcels,  whereby  each  parcel  may  be  composed  of  equally 
long  hairs.  The  perfection  of  the  pencil  depends  upon  this  equality ;  the  tapering  point 
being  produced  simply  by  the  attenuation  of  the  tips. 

A  pinch  of  one  of  these  parcels  is  then  taken,  of  a  thickness  corresponding  to  the  in- 
tended size  of  the  pencil ;  it  is  set  in  a  little  tin  pan,  with  its  tips  undermost,  and  is  shaken 
bv  striking  the  pan  on  the  table  as  before.  The  root  end  of  the  hairs  being  tied  by  the 
fisnerman's  or  seaman's  knot,  with  a  fine  thread,  it  is  taken  out  of  the  pan,  and  then 
hooped  with  stronger  thread  or  twine ;  the  knots  being  drawn  very  tight  by  means  of  two 
little  sticks.  The  distance  from  the  tips  at  which  these  ligatures  are  placed,  is  of  course 
relative  to  the  nature  of  the  hair,  and  the  desired  length  of  the  pencil.  The  base  of  the 
pencil  must  be  trimmed  flat  with  a  pair  of  scissors. 

Nothing  now  remains  to  be  done  but  to  mount  the  pencils  in  quill  or  tin-plate  tubes  as 
above  described.  The  quills  are  those  of  swans,  geese,  ducks,  lapwings,  pigeons,  or  larks, 
according  to  the  size  of  the  pencil.  They  are  steeped  during  24  hours  m  water,  to  swell 
and  soften  them,  and  to  prevent  the  chance  of  their  splitting  when  the  hair  brush  is  pressed 
into  them.  The  brush  of  hair  is  introduced  by  its  tips  into  the  large  end  of  the  cut  quill, 
having  previously  drawn  them  to  a  point  with  the  lips,  when  it  is  pushed  forwards  with 
a  wire  of  the  same  diameter,  till  it  comes  out  at  the  other  and  narrower  end  of  the  quill. 

The  smaller  the  pencils,  the  finer  ought  the  hairs  to  be.  In  this  respect,  the  manufacture 
requires  much  delicacy  of  tact  and  experience.  It  is  said  thai  there  are  only  four  first-rate 
hands  among  all  the  dexterous  pencil-makers  of  Paris,  and  that  these  are  principally  women. 

HALOGENE  is  a  term  employed  by  Berzelius  to  designate  those  substances  which 
form  compounds  of  a  saline  nature,  by  their  union  with  metals ;  such  are  Bromintf 
Chlorine,  Cyanogenej  FluorinCf  Iodine.    Haloid  is  his  name  oi  the  salt  thereby  formed. 

HANDSPIKE  is  a  strong  wooden  bar,  used  as  a  lever  to  move  the  windlass  and  cap- 
stan in  heaving  up  the  anchor,  or  raising  any  heavy  weights  on  board  a  ship.  The 
handle  is  smooth,  round,  and  somewhat  taper ;  the  other  end  ?«  squared  to  fit  the  holes  in 
the  head  of  the  capstan  or  barrel  of  the  windlass. 

HARDNESS  (Buret e,  Fr. ;  Harte,  Festigkeity  Germ.)  is  tnat  modification  of  cohesive 
attraction  which  enables  bodies  to  resist  any  eflfort  made  to  aDradc  their  surfaces.  Its  rel« 
ative  intensity  is  measured  by  the  power  they  possess  of  cuiung  or  scratching  other  sub- 
sttnces.  The  following  table  exhibits  pretty  nearly  tne  successive  hardnesses  of  the 
several  bodies  in  the  list.*— 


Substances. 

Hardness. 

Specihc  Gravity. 

Diamond  from  Ormus     .... 

20 

3-7 

1 

Pink  diamond           .... 

19 

3*4 

Bluish  diamond                .... 

19 

3-3 

Yellowish  diamond  .... 

19 

3-3 

Cubic  diamond   ..... 

18 

3-2 

Ruby            -            -            .            -            . 

17 

4-2 

Pale  ruby  from  Brazil    -            -            .            . 

16 

3-5 

Deep  blue  sapphire  -           -           -           - 

16 

3-8 

Ditto,  paler         -            .            -            -            . 

17 

3-8 

Topaz 

15 

4-2 

Whitish  topaz     ..... 

14 

3-5 

Ruby  spinell             .... 

13 

34 

Bohemian  topaz  ..... 

11 

2-8 

Emerald       .           .           •           •           . 

12 

2-8 

Garnet    ...... 

12 

4-4 

Agate           ..... 

12 

2-6 

Onyx      -..-.. 

12 

2-6 

Sardonyx      -             -             .             .             , 

12 

2*6 

Occidental  amethyst       .... 

11 

2-7 

Crystal         ..... 

11 

2*6 

Cornelian            ..... 

11 

2-7 

Green  jasper            .... 

11 

2-7 

Reddish  yellow  do.          . 

9 

^0   • 

2-6 

Schoerl         ..... 

(0 

m0     \# 

3*fi 

Tourmaline        ..... 

10 

3*0 

Quartz         ..... 

10 

2-7 

\ 

Opal       --.... 

(0 

2-6 

Chrysolite    ..... 

10 

3*7 

Zeolite 

8 

2-1 

Fluor           -            -            .            .            . 

7 

3*5 
2-7 

Calcareous  spar              .... 

9 

6 

Gypsum       -            -           -            -            . 

5 

2*3 

Chalk 

3 

2-7 

HARTSHORN,  SPIRIT  OF,  is  the  old  name  for  water  of  ammonia. 

HATCHING  OF  CHICKENS.  See  Incubation,  Artificial. 
^  HAT  MANUFACTURE.  (Uart  de  Chapelier,  Fr. ;  Hutmacherkunst,  Germ.)  Hat 
IS  the  name  of  a  piece  of  dress  worn  upon  the  head  by  both  sexes,  but  principally  by  the 
men,  and  seems  to  have  been  first  introduced  as  a  distinction  among  the  ecclesiastics  in 
the  12th  century,  though  it  was  not  till  the  year  1400  that  it  was  generally  adopted  by 
respectable  laymen.  ' 

As  the  art  of  making  common  hats  does  not  involve  the  description  of  any  curious  ma- 
chinery, or  any  interesting  processes,  we  shall  not  enter  into  very  minute  details  upon 
the  subject.  It  will  be  sufficient  to  convey  to  the  reader  a  general  idea  of  the  methods 
employed  in  this  manufacture. 

The  materials  used  in  making  stuflf  hats  are  the  furs  of  hares  and  rabbits  freed  from 
the  long  hair,  together  with  wool  and  beaver.  The  beaver  is  reserved  for  the  finer  hats. 
The  fur  is  first  laid  upon  a  hurdle  made  of  wood  or  wire,  with  longitudinal  openings  • 
■nd  the  operator,  by  means  of  an  instrument  called  the  bow  (which  is  a  piece  of  elastic 
asn,  SIX  or  seven  feet  long,  with  a  catgut  stretched  between  its  two  extremities,  and  made 
10  vibrate  by  a  bowstick),  causes  the  vibrating  string  to  strike  and  play  upon  the  fur  so 
as  to  scatter  the  fibres  in  all  directions,  while  the  dust  and  filth  descend  through  the  grids 
of  the  hurdle.  ® 

After  the  fur  is  thus  driven  by  the  bow  from  the  one  end  of  the  hurdle  to  the  other,  il 
forms  a  mass  called  a  bat,  which  is  only  half  the  quantity  sufficient  for  a  hat.  The 
bat  or  capade  thus  formed  is  rendered  compact  by  pressing  it  down  with  the  hardenine 
skin  (a  piece  of  half-tanned  leather),  and  the  union  of  the  fibres  is  increased  by  covering 
them  with  a  cloth,  while  the  workman  presses  them  together  repeatedly  with  his  hands. 
Ihe  cloth  being  taken  off,  a  piece  of  paper,  with  its  corners  doubled  in,  so  as  to  give  it 
a  triangular  outline,  is  laid  above  the  bat.  The  opposite  edges  of  the  bat  are  then  folded 
over  the  paper,  and  being  brought  together  and  pressed  again  with  the  hands,  they  form 
«  conica  cap.    This  cap  is  next  laid  upon  another  bat,  ready  hardened,  so  that  the  joined 


994 


HAT  MANUFACTURE. 


edges  of  the  first  bat  rest  upon  the  new  one.  This  new  bat  is  folded  over  the  other  and 
Its  ed^es  joined  by  pressure  as  before ;  so  that  the  joining  of  the  first  conical  cap  is 
opposite  to  that  of  the  second.  This  compound  bat  is  now  wrought  with  the  hands  for  a 
considerable  time  upon  the  hurdle  between  folds  of  linen  cloth,  being  oc:»sionallv  SDrinkl«l 
with  clear  water,  till  the  hat  is  basined  or  rendered  tolerably  firm. 

The  cap  is  now  taken  to  a  wooden  receiver,  like  a  very  flat  mill-hopper,  consisting  of 
eight  wooden  planes,  sloping  genUy  to  the  centre,  which  contains  a  kettle  filled  with 

742    yK — 7V  water    acidulated   with    sulphuric   acid.       The 

technical  name  of  this  vessel  is  the  battery.    It 
consists  of  a  kettle  a  ;  and  of  the  planks,  b  c, 
which  are  sloping  planes,  usually  eight  in  num- 
ber,  one  being  allotted  to  each  workman.      The 
half  of  each  plank  next  the  kettle  is  made  of 
lead,  the  u pper  half  of  mahogany .     In  this  liq uor 
the  hat  is  occasionally  dipped,  and  wrought  by 
the  hands,  or  sometimes  with  a  roller,  upon  the 
iloping  planks.      It  is  thus  fulled  or  thickened 
during  four  or  five  hours ;  the  knots  or  hard  sub- 
stances  are  picked  out  by  the  workman,  and  fresh 
felt  is  added  by  means  of  a  wet  brush  to  those 
parts  that  require  it.     The  beaver  is  applied  at 
the  end  of  this  operation.      In  the  manufacture 
of  beaver  hats,  the  grounds  of  beer  are  added  to 
the  liquor  in  the  kettle. 
btopping,  or  thickening  the  thin  spots,  seen  by  looking  through  the  body,  is  performed 
by  daubing  on  additional  stuff  with  successive  applications  of  the  hot  acidulous  liquor 
from  a  brush  dipped  into  the  kettle,  until  the  body  be  sufficiently  shrunk  and  made 
nnilorm.    After  drying,  it  is  stiffened  with  varnish  composition  rubbed  in  with  a  brush; 
the  inside  surface  being  more  copiously  imbued  with  it  than  the  outer:  while  the  brim  is 
peculiarly  charged  with  the  stiffening. 
When  once  more  dried,  the  body  is  ready  to  be  covered,  which  is  done  at  the  battery. 
nrst  cover  of  beaver  or  napping,  which  has  been  previously  iourerf,  is  strewed  equably 
over  the  body,  and  patted  on  with  a  brush  moistened  with  the  hot  liquor,  until  it  gets  in- 
corporated;  the  cut  ends  towards  the  root,  being  the  points  which  spontaneously  intrude, 
ine  body  is  now  put  into  a  coarse  hair  cloth,  then  dipped  and  rolled  in  the  hot  liquor, 
until  the  root  ends  of  the  beaver  are  thoroughly  worked  in.      This  is  technically  called 
rolling  off,  or  roughing.    A  strip  for  the  brim,  round  the  edge  of  the  inside,  is  treated  in 
ibe  same  way;  whereby  every  thing  is  ready  for  the  second  cover  (of  beaver),  which  is 
incorporated  in  like  manner;  the  rolling,  &c.  being  continued,  till  a  uniform,  close,  and 
weil-lelted  hood  is  formed. 

The  hat  is  now  ready  to  receive  its  proper  shape.  For  this  purpose  the  workman  turns 
up  the  edge  or  brim  to  the  depth  of  about  1|  inch,  and  then  returns  the  point  of  the  cone 
back  again  through  the  axis  of  the  cap,  so  as  to  produce  another  inner  fold  of  the  same 
aeptn.  a  third  fold  is  produced  by  returning  the  point  of  the  cone,  and  so  on  till  the 
point  resembles  a  flat  circular  piece  having  a  number  of  concentric  folds.      In  this  state 

*.VJ-  2^°"  ^^^  P^^"*^'  ^"^  ^^"^^  ^'^^^  ^^^  ^'^^^°^-  '^^^  workman  pulls  out  the  point 
wiin  his  fingers,  and  presses  it  down  with  his  hand,  turning  it  at  the  same  time  round  on 
us  centre  upon  the  plank,  till  a  flat  portion,  equal  to  the  crown  of  the  hat,  is  rubbed  out. 
inis  nat  crown  is  now  placed  upon  a  block,  and,  by  pressing  a  string  called  a  commander 
down  the  sides  of  the  block,  he  forces  the  parts  adjacent  to  the  crown,  to  assumTTc^: 
n«no  uJVu  ^  ^i'^  "°^  appears  like  a  puckered  appendage  round  the  cylindrica) 
cone ;  but  the  proper  figure  is  next  given  to  it,  by  working  and  rubbing  it.  The  bodv  is 
rendered  waterproof  and  stiff  by  being  imbued  with  a  varnish  composed  of  shellac 
sandarach,  mastic,  and  other  resins  dissolved  in  alcohol  or  naptha.  ' 

1  he  hat  being  dried,  its  nap  is  raised  or  loosened  with  a  wire  brush  or  card,  and  some- 
times It  IS  previously  pounced  or  rubbed  with  pumice,  to  take  off  the  coarser  part*;  and 
afterwards  rubbed  over  with  seal-skin.  The  hat  is  now  tied  with  pack-threadVp^n  ?l5 
block,  and  is  afterwards  dyed.     See  Hat-dyeing,  infra.  ^ 

onThe  iSA^tS'"  """^  T°y.'^  ^"  ^^'  '^^^'"^"^  '^'^P-  ^'^'  ^••«""^«  "e  next  applied 
and  whpn  th  K  "'°^"'?^'^  '^^  purpose  of  preventing  the  glue  from  coming  through; 
thJnol  tK      1  *^^''  /I"*^"'^'^^  ^'^  ^'\^^>  ^  "e  (gum  Senegal  is  sometimes  used)  a  little 

iSeTwer'^u^rface  "1'^?^"''"' "  '"'  "^''  ""  '"^'  '''  ''''  ^'^^^^^  °^  ^^«  ^ ^  ^^^ 
.«T^®  ^^A  i-/'?^"  softened  by  exposure  to  steam,  on  the  steaming  basin,  and  is  brushed 
and  ironed  K.1  it  receives  the  proper  gloss.  It  is  lastly  cut  round  at  the  brim  by  a  knife 
toed  at  the  end  of  a  gauge,  which  rests  against  the  crown.    The  brim,  however,  is  not 

4J 


HAT  MANUFACTUKE. 


^ 


995 

ihe  turs  and  wools  of  which  hats  are  manufactured  contain  in  fhP.V  *.arW  «»«««  «r 

whS  tKaVlh^t er  In'^  ^^ZTarfs  X^ls^Z':^^^^^^^^^ 

Messrs.  Parker  and  Harris  obtained  a  patent  in  1822  for  the  inrr,  L  T^  T^u 

an  apparatus,  whose  structure  and  functLns  may  be  peifect  v  uidlr^^^^^  T    T  ""^  T** 

organized  combination  which  exists  among  journeyman  hat^e?st 

by  which  the  masters  are  held  in  a  state  of  compSemiude  LvL^^       *^  kingdom, 
single  apprentice  into  their  works  beyond  th dumber  sS^  n  P^"^"  '^  '^^^  » 

of  machine  which  is  likely  to  supersede  handla^or  in  anv  r^^^^^^  "^^  *?J  ^'' 

the  hat  trade  is,  generall/ speakLg,  unproductfve  to  ?he  caS^^^^^^  "?""" 

ceivmg  any  considerable  develonrnpnt       Th«  «„ki:«    r     ^^P"^"st,  and  incapable  of  re- 

cay  l«  had  of  the  bet ''U^yl;  o^e^^^rpl^'o^TelTrS  "  """'""'•  """"  '""^ 
orT^ITni^h"!  ''fS.  Jirir?^.*?;;  «"Sf\-l»-«-.-.  ?e"-ny  employed 


Fi,.  m  is  the  frameW  „%UX;ruVn  whTrZeTSS 


lathes  are  mounted,  as  a,  b 


crown  of  the  hat  is  to  be  iron'ed.  ^Se  iMhe  b  whe^  he^at  m  *"  T.^'°^'^  "'™  "« 
.he  brim  is  ironed,  and  lathe  c,  when  its  „„der'sWe?s  roned  motiZ  I^^L""!*'  ""'  f 
whole  by  means  of  a  band  passing  from  any  first  moveJ7asa^t?»m.nSt'2*  ^T"  '?  '^• 
&c.)  to  the  drum  on  the  main  shaft  a  a  Frim  twrn™™  .  f  «a">-™gi«e,  water-wheel, 
b,which  actuates  the  axle  of  the  lathe  *  O  "to  tWs  latr,  sor^o'f  !S  ■""  ""L"'^"! 
to  the  chuck  the  blocif  <:  is  made  fast  by  screws  hilts  or  lilT  tk-  "k?  •?  «re"«i.  and 
ed  in  section,  in  order  to  show  tlie  manner  Tn',^^h  »  ^  a  ^^f  ""'''.''  l'V"Si<il- 
fas.  by  the  centre  wedge-pteceTas  se^na?  JA«  "  '       '  •"''"'  *"" 

The  hat-block  being  made  to  turn  round  with  the  chnAc  ot  tKo  ,«»«  «r  -u     .  . 

blocJc,  is  now  removed  to  the  kthe  b  wh^re  k  W  Lr^  ''''''^T^\    w  ^^'j  ^'''^  '"^ 
^.ft  e.  and  is  ac.ulted  by  a  ^^L^'Cr.i^^tf.^l^l  Zl^S,"^^^ 


996 


HAT  MANUFACTUHE. 


I  I 


rigger/.  In  order  to  iron  the  upper  surface  of  the  brim,  the  block  c  is  removed  from 
the  lathe,  and  taken  out  of  the  hat,  when  the  block  fig.  145,  is  mounted  upon  the  chuck 
dy  and  made  to  turn  under  the  hand  of  the  workman,  as  before. 

The  hat  is  now  to  be  removed  to  the  lathe  c,  where  it  is  introduced  in  an  inverted 
position,  between  the  arms  g  g  supporting  the  rim  h  h,  the  top  surface  of  which  is 
shown  at  fig.  746.  The  spindle  t  of  the  lathe  turns  by  similar  means  to  the  last,  bul 
slower;  only  ten  turns  per  minute  will  be  sufficient.  The  workman  now  smooths  the 
under  side  of  the  brim,  by  drawing  the  iron  across  it,  that  is,  from  the  centre  outwards. 
The  hat  is  then  carefully  examined,  and  all  the  burs  and  coarse  hairs  picked  out,  after 
which  the  smoothing  process  is  performed  as  before,  and  the  dressing  of  the  hat  is  com- 
plete. 

Messrs.  Gillman  and  Wilson,  of  Manchester,  obtained  a  patent  in  1823,  for  a  peculiar 
kind  of  fabric  to  be  made  of  cotton,  or  a  mixture  of  cotton  and  silk,  for  the  covering  of 
hats  and  bonnets,  in  imitation  of  beaver.  The  foundation  of  the  hat  may  be  of  fell,  hemp, 
wool,  which  is  to  be  covered  by  the  patent  fabiic.  This  debased  article  does  not  seem  to 
have  got  into  use ;  cotton,  from  its  want  of  the  felting  property  and  inelasticity,  being 
very  ill-adapted  for  making  hat-stuff. 

A  more  ingenious  invention  of  John  Gibson,  hatter,  in  Glasgow,  consisting  of  an  elastic 
fabric  of  whalebone,  was  made  the  subject  of  a  patent,  in  June,  1824.  The  whalebone, 
being  separated  into  threads  no  larger  than  hay  stalks,  is  to  be  boiled  in  some  alkaline 
liquid  for  removing  the  oil  from  it,  and  rendering  it  more  elastic.  The  longest  threads 
are  to  be  employed  for  warp,  the  shorter  for  weft ;  and  are  to  be  woven  in  a  hair-clotk 
loom.  This  fabric  is  to  be  passed  between  rollers,  after  which  it  is  fit  to  be  cut  out  into 
forms  for  making  hats  and  bonnets,  to  be  sewed  together  at  the  joints,  and  stiffened  with 
a  preparation  of  resinous  varnishes,  to  prevent  its  being  acted  upon  by  perspiration  or 
rain.  A  very  considerable  improvement  in  the  lightness  and  elasticity  .f  siik  hats  has 
been  the  result  of  this  invention. 

The  foundation  of  men's  hats,  upon  whose  outside  the  beaver,  down,  or  other  fine  fur 
is  laid  to  produce  a  nap,  is,  as  I  have  described,  usually  made  of  wool  felted  together 
by  hand,  and  formed  first  into  conical  caps,  which  are  afterwards  stretched  and  moulded 
upon  blocks  to  the  desired  shape.  Mr.  Borradaile,  of  Bucklersbury,  obtained  a  patent 
in  November,  1825,  for  a  machine,  invented  by  a  foreigner,  for  setting  up  hat  bodies, 
which  seems  to  be  ingeniously  contrived;  but  I  shall  decline  describing  it,  as  it  has 
probably  not  been  suffered  by  the  Union  to  come  into  practical  operation,  and  as  I  shall 
presently  give  the  details  of  another  later  invention  for  the  same  purpose. 

Silk  hats,  for  several  years  after  they  were  manufactured,  were  liable  to  two  objec- 
tions ;  first,  the  body  or  shell  over  which  the  silk  covering  is  laid,  was,  from  its  hardness, 
apt  to  hurt  the  head ;  second,  the  edge  of  the  crown  being  much  exposed  to  blows,  the 
silk  nap  soon  got  abraded,  so  as  to  lay  bare  the  cotton  foundation,  which  is  not  capable 
of  taking  so  fine  a  black  dye  as  the  silk ;  whence  the  hat  assumed  a  shabby  appearance. 
Messrs.  Mayhew  and  White  of  London,  hat-manufacturers,  proposed  in  their  patent  of 
February,  1826,  to  remedy  these  defects,  by  making  the  hat  body  of  stuff  or  wool,  and 
relieving  the  stiffness  of  the  inner  part  round  the  brim,  by  attaching  a  coaling  of  beavei 
upon  the  under  side  of  the  brim,  so  as  to  render  the  hat  pliable.  Round  the  edge  of 
the  tip  or  crown,  a  quantity  of  what  is  called  stop  wool  is  to  be  attached  by  the  ordinary 
operation  of  bowing,  which  will  render  the  edge  soft  and  elastic.  The  hat  is  to  be  after- 
wards dyed  of  a  good  black  color,  both  outside  and  inside ;  and  being  then  properly  stiff- 
ened and  blocked,  is  ready  for  the  covering  of  silk. 

The  plush  employed  for  covering  silk  hats,  is  a  raised  nap  or  pile  woven  usually  upoH 
a  cotton  foundation  ;  and  the  cotton,  being  incapable  of  receiving  the  same  brilliant 
black  dye  as  the  silk,  renders  the  hat  apt  to  turn  brown  whenever  the  silk  nap  is  partially 
worn  off.  The  patentees  proposed  to  counteract  this  evil,  by  making  the  foundation  of 
the  plush  entirely  of  silk.  To  these  two  improvements,  now  pretty  generally  introduced, 
the  present  excellence  of  the  silk  hats  may  be,  in  a  good  measure,  ascribed. 

The  apparatus  above  alluded  to,  for  making  the  foundations  of  hats  by  the  aid  of  me- 
chanism, was  rendered  the  subject  of  a  patent,  by  Mr.  Williams,  in  September,  1826  ;  bul 
I  fear  it  has  never  obtained  a  footing,  nor  even  a  fair  trial  in  our  manufactures,  on  ac 
count  of  the  hostility  of  the  operatives  to  all  labor-saving  machines. 

Fig,  747  is  a  side  view  of  the  carding  engine,  with  a  horizontal  or  plan  view  of  the 
lower  part  of  the  carding  machine,  showing  the  operative  parts  of  the  winding  apparatus, 
as  connected  to  the  carding  engine.  The  doffer  cylinder  is  covered  with  fillets  of 
wire  cards,  such  as  are  usually  employed  in  carding  engines,  and  these  fillets  are 
divided  into  two,  three,  or  more  spaces  extending  round  the  periphery  of  the  cylinder, 
the  object  of  which  division  is  to  separate  the  sliver  into  two,  three,  or  more  breadths, 
which  are  to  be  conducted  to,  and  wound  upon  distinct  blocks,  for  making  so  many  sep. 
a  rate  hats  or  caps. 


)  I 


HAT  MANUFACTURE.  997 


748 


il^I'y^r^^lteiZ^T^^^^  by  a  horizontal  lever  Z/  (seen  in 

to  the  carriage  at  on!  exUemhynlXJl  ^h^nT  ^'Vt  *"'  '^^'''^  ^^^^^  »^  ««««hed 
drawsthesidlof  thislefer  agafnSa  a  weighted  cord  which 

means  of  a  band  and  pulley!  whch  turns  the  shaft  nn/"./'  "^'^^  '^ '"^^^^'^  ^^ 

endless  screw  taking  into  a  tS,thed  wheeTr  on  the  axWr  t?      ''  '"''"^  ^'  *?**  *^« 

to  revolve,  the  Derioherv  of  wh.Vh  ZJl       *  ^  ^^^  ^^'^  **^  ^^^  cam  0,  causes  the  cam 

the  lever  /  causes  ieWer  to  v^b^^^^  against  a  friction  roller  on  the  side  of 
and  fro  u'pon  t^e  supS^rol  e^^^ 

laid  in  oblique  di>ecuX  ^^Tni  ««  Tl  f    •  ^^\   ^^  ^^^^^  "^^"^  ^^^  ^"^^'^  '^ 
blocks.  «*'^e"'ons  (varying  as  the  carnage  traverses),  over  the  surface  of  the 

ord^r'to'wind  JhtflirrJIfh 'S^n't  ^' '^^'^^  ^"^^^^I  '^"'^^'  ''  '^  — ^>  - 
diameter  of  that  part  of  thrWockwS  \^f '""'.^?  ^^,7  *^^"•  '1^^  according  to  the 

givi,.g  different  veVit^s  to  the  p\lTe;t  ^''^  ^^  '""'''^^  »>y 

with  .    There  is  a  similar  coniL/^ Si  t  ^tatd^^ii'^  IZt  tsUio'i  T^^ 


998 


HAT  MANUFACTURE. 


part  of  the  frame,  which  is  actuated  by  a  band  from  any  convenient  part  of  the  machine 
passing  over  a  pulJej  u  upon  the  axle  of  t.     From  the  drum  /,  ,o  the  drum  I,  ih°rc  ^  a 

^  the'le'^eit  "^  *     °  ^^  ^^^  ^"*'^^"''  °^  ^""^  rollers  at  the  cad 

It  will  now  be  seen  that  when  the  larger  diameter  of  the  cam  wheel  o  forces  the  lever 
outwards  the  band  v  will  be  guided  on  to  the  smaller  part  of  the  conical  drum  /and7l" 
larger  part  of  5,  consequently  the  drum  *  will  at  this  time  receive  its  slowest  motion  anS 
the  band  g  wtl  turn  the  blocks  slower  also ;  the  reverse  end  of  tL  leverThlv^nTEy  the 
same  movement  slidden  the  carriage  into  that  position  which  causes  the  sUve?s  to  w  nd 
upon  the  larger  diameter  of  the  blocks.  severs  10  wina 

When  the  smaller  diameter  of  the  cam  is  acting  against  the  side  of  the  lever  the 
weighted  cord  draws  the  end  of  the  lever  to  the  opposite  side,  and  th^  band  v  wHl  te 
guided  on  to  the  larger  part  of  the  cord  t,  and  the  smaller  part  of  the  cone  ,  consLuentlv 
the  quicker  movement  of  the  band  g  will  now  cause  the  Lcks  .  '  t^revoCwTa  cor! 
responding  speed.  The  carriage/  will  also  be  moved  upon  its  rollers,  to  the  reverse  X 
n?  thP  Kl 'T  ""^  TV^y  other  material  be  now  wound  upon  the  smaller  p.rte  and  ends 
of  the  blocks,  at  which  time  the  quicker  rotation  of  the  blocks  is  required.    It  may  b^ 

ent  .h"at'd'h?n  T'  '^\  '""5  ""^"'^  '  ^^""^^  ^'  ^'«'^''^"^'y  ^^'^^  -^^«^ding  to  the  diffe^ 

It  only  remains  to  state,  that  there  are  two  heavy  conical  rollers  w  w,  bearing  upon 
the  periphenes  of  the  blocks  e  e,  which  turn  loosely  upon  their  axles  by  the  frictbn 
of  contac,  for  the  purpose  of  pressing  the  slivers  of  wool  or  other  material  orihe 
blocks  as  It  comes  from  the  doffer  cylinder  of  the  carding  engine,  and  Xn  the  Wocks 
have  been  coated  with  a  sufficient  quantity  of  the  sliver, Ihe  smal  e^enHf  the  pressin' 
rollers  IS  to  be  raised  while  the  cap  is  withdrawn  from' the  block      The  proces/^^^^^ 

After  the  caps  or  bodies  of  hats,  &c.  are  formed  in  the  above  described  machine  ther 
are  folded  m  wet  cloths,  and  placed,  upon  heated  plates,  where  they  fre  rolled  u^der 
fZ™'*^'  the  purpose  of  being  hardened.  Fig.  748 'represents  ^the  fron  of  three 
furnaces  a  a  a,  the  tops  of  which  are  covered  with  iron  plates  6  6  b.  Upon  these  0^"^ 
which  are  bleated  by  the  furnace  below,  or  by  steam,  the  bodies  wrap^  in  the  w^t 
cloths  cc  c,  are  placed,  and  pressed  upon  by  the  flaps  or  covers  d  d  d,  sliding  u^a 

S;"a^in'.  "a'^/^MAr^"^  "f^  "  ^-->  ^^ '-eans  of  chains  attaJhK 
an  alternating  bar  e  e.  This  bar  is  moved  by  a  rotatory  crank  /,  which  has  its  motion 
by  pulleys  from  any  actuating  power.     When  any  one  of  the  flaps  is  turn«iTntn 

r^ar;''    "^^  '""  '^"^^^''  ^^^  ^^^  ^-S    ^--ly '  -d  t'e  fla^lemU^ 
These  caps  or  hat  bodies,  after  having  been  hardened  in  the  manner  above  described 
may  be  felted  in  the  usual  way  by  hand,  or  they  are  felted  in  a  Sg  mT  by  the  us^l 

rc"fumn^Tin'r."'""^'K''''  ''''':.  '""V"'  ^^^  ^«d'«^  "«  oSi^ill?^  taken  ou 
of  the  fulling  mill,  and  passed  between  rollers,  for  the  purpose  of  rendering  the  felt  more 

"^^^  '^^^  Mr.    Carey,  of  Basford,    ob- 

tamed  a  patent  in  October,  1834, 
for  an  invention  of  certain  ma- 
chinery to  be  employed  in  the 
manufacture  of  hats,  which  is 
ingenious,  and  seems  to  be  worthy 
of  notice  in  this  place.  It  con- 
sists in  the  adaptation  of  a  sys- 
tem of  rollers,  forming  a  machine^ 
by  means  of  which  the  operation 
of  roughing  or  plaiting  of  hats 
may  be  performed;  that  is,  the 
beaver  or  other  fur  may  be  made 
to  attach  itself,  and  work  into 
the  felt  or  hat  body,  without  the 
necessity  of  the  ordinary  manual 

fig-  wo  U  .  side  elevatioD  of  the  sa^e  " /s/Vl  ?''.  wf,  a'T""  ?^  ">«»?«"'"* ' 


i 


HAT  MANUFACTURE. 


999 


Upon  a  brick  or  other  suitable  base,  a  furnace  or  fire-place  a,  is  made,  having  a  descend- 

^^^  ing  flue  6,  for  the  purpose  of  cany. 

ing  away  the  smoke.      A  pan  or 
shallow  vessel  c  c,  formed  of  lead, 
is  placed  over  the  furnace ;  which 
vessel  is  intended  to  contain  a  sou*- 
liquor,  as  a  solution  of  vitriolic  acid 
and  water.      On  the  edge  of  this 
pan  is  erected   a  wooden  casing 
dd  dj  which  encloses  three  sides, 
leaving   the   fourth   open   for    the 
purpose  of  obtaining  access  to  the 
working  apparatus  within.   A  series 
of  what   may   be  termed    lantera 
rollers,  €  «  «,  is  mounted  on  axles 
turning  in  the  side  casings;   and 
another  series  of  similar   lantern 
rollers,  /  /  /,  is   in   like  manner 
mounted    above.      These    lantern 
rollers  are  made  to  revolve  by  means 
of  bevel  pinions,  fixed  on  the  ends 
of  their   axles,  which   are   turned 
by  similar  bevel  wheels  on  the  lat- 
eral shafts  g  and  h,  driven  by  a 
winch   t,   and   gear,  as  shown   hi 
fig'-  ^49  and  150, 

Having  prepared  the  bodies  of 
the  hats,  and  laid  upon  their  sur- 
faces the  usual  coatings  of  beaver, 
or  other  fur,  when  so  prepared  tltey 
are  to  be  placed  between  hair  cloths, 

a  canvass  or  other  suitable  wrapper.     Three  or  more'hltf  bdn"?nc£^^^^^ 
wrapper,  the  packages  are  severally  put  into  bags  or  pockets  in  an  Pndtfc  K»nT«f  c    u 

}^J^v  ?-^'  »"s[*"ce,  for  the  purpose  of  merely  attaching  the  furs  to  the  felts  Twhich  ir 
caned  slicking,  when  performed  by  hand),  Mr.  Carey  prefer!  to  pass  the  endles   Lnd  i  fe  k 
with  the  covered  hat  bodies,  over  the  upper  series  f  f  f  nf  thl  io„*  !       ii   »antiAc/tft, 
to  avoid  the  inconvenience  of  disturbingThe  furwhfeh^4ht    c^  rS  ^i^g  ?h1S 
the'lXr  ""  ''"'  '"'^"^"'^  '^  ^^'  P""'  ^'^""'^  ^^«  ^"^  ^^d  become  a^UcVc^  to 

After  this  operation  of  slicking  has  been  effected,  he  distends  the  endless  band  kkk. 
over  the  lower  series  of  lantern  rollers  e  e  «,  and  round  a  carrier  rnllpr  /  odi,  «,    •    J^ 
751 ;  and  having  withdrawn  the  hat  bodies  for  the  purposeT  ra2ng\h^m^^^^^ 
ing  their  folds,  he  packs  them  again  in  a  similar  way  in  flannel,  oimher  stable  cloil" 
and  introduces  them  into  the  pockets  or  bags  of  the  endless  bands,  as  before  ^ 

.»^"J"l''"^.i*'^"f'^J'*^''y  ^»  rotatory  motion  in  the  way  described  the  hats  will  be 
carried  along  through  the  apparatus,  and  subjected  to  the  scalding  solu  ion  in  ihe  In  « 
also  to  the  pressure,  and  to  a  tortuous  action  between  the  ribs  of  the  lantern  rollers  as  Ihe^ 
revolve,  which  will  cause  the  ends  of  the  fur  to  work  into  the  feltS  Ses  ofX  h-»^^^ 
and  by  that  means  permanently  to  attach  the  nap  to  the  body  •  an  onP,^n  Jl-  J^  u  '  * 
performed  by  hand,  is  called  rolling  off.  ^ '        operation  which,  when 

The  improved  stiffening  for  hat  bodies  oroDospH  hv  Mw  -ni- j  j      v 

January   ,828,  consists  in  making  his  s"  uToHr'sh'iSl.f  I„t'Sre",ey"  nS'  It 
spirits  of  wine,  or  pyroiylic  spirit,  vulgarly  called  naptha  ^«""e  'ey.  '"Stead  of 

of  ^alt^TSSlr'fcarnWS^^  t"-  ^f  '\  ^-^« 

be  put  into  a  kettle,  and  madrto  b^il  grad^alfy  Ztif  the  !«;  is  S.?.nw'"' k  "^.t"* 
liquor  will  become  as  clear  as  water,  wfthout  aVsuii'^pJS  the  op '^ni  7f  feft  'tJ 
cool  will  have  a  thin  crust  upon  its  surface  of  a  whitish  caTmixed  whh  thl  Lk.  • 
purities  of  the  gum  When  this  skin  is  taken  off,  the  hafbSy  Is  To  be  dlpi^'^lit 
the  mixture  in  a  cold  state,  so  as  to  absorb  as  much  as  possible  Vh ;  or  hmav^ 
applied  with  a  brush  or  sponge.  The  hat  body,  being  thus  stiffened,  may  slndtill^ 
become  dry  or  nearly  so;  and  after  it  has  been' brushed,  it  must  be  immLsed  in  ve^ 
dilute  sulphuric  or  acetic  acid,  in  ord.-  to  neutralize  the  po'tash,  and  caiTe  Se  shiSac  2 


1000 


HAT  MANUFACTURE. 


•et.     If  the  hats  are  not  to  be  napped  immediately,  they  may  be  thrown  into  a  cistern  of 
pure  water,  and  taken  out  as  wanted. 

Should  the  hat  bodies  have  been  worked  at  first  with  sulphuric  acid  (as  usual),  they 
must  be  soaked  in  hot  water  to  extract  the  acid,  and  dried  before  the  stiffening  is  applied 
care  being  taken  that  no  water  falls  upon  the  stiffened  body,  before  it  has  been  immersed 
in  the  acid. 

This  ingenious  chemical  process  has  not  been,  to  the  best  of  my  knowledge,  intro- 
duced into  the  hat  manufacture.  A  varnish  made  by  dissolving  shellac,  mastic,  sand- 
arach,  and  other  resins  in  alcohol,  or  the  naptha  of  wood  vinegar,  is  generally  employed 
as  the  stiffening  and  water-proof  ingredient  of  hat  bodies.  A  solution  of  caoutchouc  is 
oflen  applied  to  whaletone  and  horse-hair  hat  bodies. 

The  following  recipe  has  been  prescribed  as  a  good  composition  for  stiffening  hats ; 
four  parts  of  shellac,  one  part  of  mastic,  one  half  of  a  part  of  turpentine,  dissolved  in 
five  parts  of  alcohol,  by  agitation  and  subsequent  repose,  without  the  aid  of  heat.  This 
stiffening  varnish  should  be  applied  quickly  to  the  body  or  foundation  with  a  soft  ob- 
long brush,  in  a  dry  and  rather  warm  workshop ;  the  hat  being  previously  fitted  with  its 
mside  turned  outwards  upon  a  block.  The  body  must  be  immediately  afterwards  taken 
off,  to  prevent  adhesion. 

Hat-Dyeing.— The  ordinary  bath  for  dyeing  hats,  employed  by  the  London  manufacturers, 
consists,  for  12  dozen,  of— 

144  pounds  of  logwood ; 

12  pounds  of  green  sulphate  of  iron,  or  copptitis ; 
7f  pounds  of  verdigris. 
The  copper  is  usually  made  of  a  semi-cylindrical  shape,  and  should  be  surrounded  with 
an  iron  jacket  or  case,  into  which  steam  may  be  admitted,  so  as  to  raise  the  temperature 
of  the  interior  bath  to  190°  F.,  but  no  higher,  otherwise  the  heat  is  apt  to  affect  the 
stiffening  varnish,  called  the  gum,  with  which  the  body  of  the  hat  has  been  imbued. 
The  logwood  having  been  introduced  and  digested  for  some  time,  the  copperas  and 
verdigris  are  added  in  successive  quantities,  and  in  the  above  proportions,  along  with 
cvAy  successive  two  or  three  dozens  of  hats,  suspended  upon  the  dipping  machine. 
Each  set  of  hats,  after  being  exposed  to  the  bath  with  occasional  airings  during  40 
minutes,  is  taken  off  the  pegs,  and  laid  out  upon  the  ground  to  be  more  completely 
blackened  by  the  peroxydizement  of  the  iron  with  the  atmospheric  oxygen.  In  3  or  4 
hours  the  dyeing  is  completed.  When  fully  dyed,  the  hats  are  well  washed  in  running 
water.  * 

Mr.  Buffum  states  that  there  are  four  principal  objects  accomplished  by  his  patent  inven- 
tion for  dyeing  hats. 

1.  in  the  operation  ; 

2.  the  production  of  a  better  color; 

3.  the  prevention  of  any  of  the  damages  to  which  hats  are  liable  in  the  dyeing ; 

4.  the  accomplishment  of  the  dyeing  process  in  a  much  shorter  time  than  by  the  usual 
methods,  and  consequently  lessening  the  injurious  effects  of  the  dye- bath  upon  the  texture 
of  the  hat. 

Fig.  753  shows  one  method  of  constructing  the  apparatus,     a  a  is  a  semi-cylindrical 


shaped  copper  vessel,  with  flat  ends,  in  which  the  dyeing  process  is  carried  on.  bbbia 
n  wheel  with  several  circular  rims  mounted  upon  arms,  which  revolve  upon  an  axle  c. 
In  the  face  of  these  rims  a  number  of  pegs  or  blocks  are  set  at  nearly  equal  distances 
tpart,  upon  each  of  which  pegs  or  blocks  it  is  intended  to  place  a  hat,  and  as  the  whed 


HAT  MANUFACTURE. 


1001 


i 


revolves,  to  pass  it  inio  and  out  of  the  dyeing  liquor  in  the  vat  or  copper.  This  wheel 
may  be  kept  revolving  with  a  very  slow  motion,  either  by  gear  connecting  its  axlo,  o, 
with  any  moving  power,  or  it  may  be  turned  round  by  hand,  at  intervals  of  ten  minutes : 
whereby  the  hats  hung  upon  the  pegs,  will  be  alternately  immersed  for  the  space  of  ten 
minutes  in  the  dyeing  liquor,  and  then  for  the  same  space  exposed  to  the  atmospherir 
air.  In  this  way,  the  process  of  dyeing,  it  is  supposed,  may  be  greatly  facilitated  and 
improved,  as  the  occasional  transition  from  the  dye  vat  into  the  air,  and  from  the  air 
again  into  the  bath,  will  enable  the  oxygen  of  the  atmosphere  to  strike  the  dye  more  per 
feclly  and  expeditiously  into  the  materials  of  which  the  hat  is  composed,  than  by  a  continued 
immersion  in  the  bath  for  a  much  longer  time. 

A  variation  in  the  mode  of  performing  this  process  is  suggested,  and  the  apparatus 
Jig.  754  is  proposed  to  be  employed,  a  a  is  a  square  val  or  vessel  containing  the  dyeing 
liquor ;  6  6  is  a  frame  or  rack  having  a  number  of  pegs  placed  in  it  for  hanging  the  hats 
upon,  which  are  about  to  be  dyed,  in  a  manner  similar  to  the  wheel  above  described. 
This  frame  or  rack  is  suspended  by  cords  from  a  crane,  and  may  in  that  way  be  lowered 
down  with  the  hats  into  the  vat,  or  drawn  up  and  exposed  in  the  air ;  changes  which  may 
be  made  every  10  or  20  minutes. 

I  have  seen  apparatus  of  this  kind  doing  good  work  in  the  hat-dyeing  manufactories 
of  London,  that  being  a  department  of  the  business  with  which  the  Union  has  not  thought 
it  worth  their  while  to  interfere. 

Mr.  William  Hodge's  patent  improvements  in  hat  dyeing,  partly  founded  upon  an 
invention  of  Mr.  Bowler,  consist,  first  in  causing  every  alternate  frame  to  which  the 
suspenders  or  blocks^  are  to  be  attached,  to  slide  in  and  out  of  grooves,  for  the  purpose 

of  more  easily  removing  the  said 
suspenders  when  required.  Fig. 
755  represents  the  improved  dye- 
ing frame,  consisting  of  two  cir- 
cular rims,  a  a,  which  are  con- 
nected together  at  top  and  bottom, 
by  three  fixed  perpendicular  bars 
or  the  frame-work  6  6  6.  Two 
other  perpendicular  frames  c  c, 
similar  to  the  former,  slide  in 
grooves,  dd  (f  (2,  fixed  to  the  upper 
and  lower  rims.  These  grooves 
have  anti-friction  rollers  in  them, 
for  the  purpose  of  making  the 
frames  c  c,  to  slide  in  and  out 
more  freely.  The  suspenders  or 
substitutes  for  blocks,  by  these 
means,  may  be  more  easily  got  at 
by  drawing  out  the  frames  c  c, 
about  half  way,  when  the  suspend- 
ers, which  are  attached  to  the 
frames  with  the  hats  upon  them^ 
may  be  easily  reached,  and  either 
removed  or  altered  in  position; 
and  when  it  is  done  on  one  side,  the  sliding  frame  may  be  brought  out  on  the  other,  and 
the  remaining  quantity  of  "suspenders"  undergo  the  same  operation. 

The  patentee  remarks,  that  it  is  well  known  to  all  hat  dyers,  that  after  the  hats  have 
been  in  the  dyeing  liquor  some  time,  they  ought  to  be  taken  out  and  exposed  to  the 
action  of  the  atmospheric  air,  when  they  are  again  immersed  in  the  copper,  that  part  of 
the  hat  which  was  uppermost  in  the  first  immersion,  being  placed  downwards  in  the 
second.  This  is  done  for  the  purpose  of  obtaining  a  uniform  and  regular  dye.  The 
patentee's  mode  of  carrying  this  operation  into  effect,  is  shown  in  the  figure :  «  «  are 
pivots  for  the  dyeing-frame  to  turn  upon,  which  is  supported  by  the  arms  /,  from  a  crane 
above.  The  whole  apparatus  may  be  raised  up  or  lowered  into  the  copper  by  means  of 
the  crane  or  other  mechanism.  When  the  dyeing-frame  is  raised  out  of  the  copper,  the 
whole  of  the  suspenders  or  blocks  are  reversed,  by  turning  the  apparatus  over  upon  the 
pivots  e  «,  and  thus  the  whole  surfaces  of  the  hats  are  equally  acted  upon  by  the  dyeing 
material. 

It  should  be  observed,  that  when  the  dyeing-frame  is  raised  up  out  of  the  copper,  it 
should  be  tilted  on  one  side,  so  as  to  make  all  the  liquor  run  out  of  the  hats,  as  also  to 
cause  the  rims  of  the  hats  to  hang  down,  and  not  stick  to  the  body  of  the  hat,  or  leave 
a  bad  place  or  uneven  dye  upon  it.     The  second  improvement  described  by  the  patentee 
is  the  construction  of  "  suspenders,"  to  be  substituted  instead  of  the  ordinary  blocks. 


1002 


HATS. 


HATS. 


1003 


These  "  suspenders"  are  composed  ot  Ihin  plates  of  copper,  bent  into  the  reqjired 
Ibrm,  that  is,  nearly  resembling  that  of  a  hat  block,  and  made  in  such  a  manner  as  to  he 
capable  of  contraction  and  expansion  to  suit  different  sized  hats,  and  keep  them 
distended,  which  may  be  altered  by  the  workmen  at  pleasure,  when  it  is  required  to 
place  the  hats  upon  them,  or  remove  them  therefrom.  The  dyeing-frame  at  fig.  546  is 
shown  with  only  two  of  these  "  suspenders,"  in  order  to  prevent  confusion.  One  of  these 
suspenders  is  represented  detached  at  fig.  547,  which  exhibits  a  side  view;  and/ig.  548 
a  front  view  of  the  same.  It  will  be  seen  by  reference  to  the  figure,  that  the  suspenders 
consist  of  two  distinct  parts,  which  may  be  enlarged  or  collapsed  by  a  variety  of  means, 
and  which  means  may  be  suggested  by  any  competent  mechanic.  The  two  parts  of  the 
suspenders  are  proposed  to  be  connected  together  by  arms  g  g,  and  at  the  junction  of 
these  arms  a  key  is  connected  for  turning  them  round  when  required.  It  will  be  seen  oa 
reference  to  the  front  view,  fig.  548,  that  the  "  suspenders"  or  substitutes  for  blocks,  are 
open  at  the  top  or  crown  part  of  the  hat;  this  is  for  the  purpose  of  allowing  the  dyeing 
liquor  to  penetrate. 

From  the  mixture  of  copperas  and  verdigris  employed  in  the  hat-dye,  a  vast  quantity 
of  an  ochreous  muddy  precipitate  results,  amounting  to  no  less  than  25  per  cent,  of  the 
weight  of  the  copperas.  This  iron  mud  forms  a  deposite  upon  the  hats,  which  not  only 
corrodes  the  fine  filaments  of  the  beaver,  but  causes  both  them  and  the  felt  stuff  to  turn 
speedily  of  a  rusty  brown.  There  is  no  process  in  the  whole  circle  of  our  manufactures 
so  barbarous  as  that  of  dyeing  stuff  hats.  No  ray  of  chemical  science  seems  hitherto  to 
have  penetrated  the  dark  recesses  of  their  dye  shops.  Some  halters  have  tried  to  remove 
this  corrosive  brown  ochre  by  a  bath  of  dilute  sulphuric  acid,  and  then  counteract  the 
evil  effect  of  the  acid  upon  the  black  dye  by  an  alkaline  bath  ;  but  with  a  most  unhappy 
effect.  Hats  so  treated  are  most  deceptions  and  unprofitable;  as  they  turn  of  a  dirfv 
brown  hue,  when  exposed  for  a  few  weeks  to  sunshine  and  air. 

Hats.  The  body  of  a  beaver  hat  is  made  of  fine  wool  and  coarse  fur  mixed  and 
felted  together,  then  stiffened  and  shaped  ;  the  covering  consists  of  a  coat  of  beaver  fur 
felted  upon  the  body.  Cheap  hats  have  their  bodies  made  of  coarse  wool,  and  their 
coverings  of  coarse  fur  or  fine  wool.  The  body  or  foundation  of  a  good  beaver  hat,  is 
at  present  made  of  8  parts  of  rabbit's  fur,  3  parts  of  Saxony  wool,  and  1  part  of  lama, 
vicunia,  or  red  wool.  About  two  ounces  and  a  half  of  the  above  mixture  are  sufficient 
for  one  hat,  and  these  are  placed  in  the  hands  of  the  bower;  his  tool  is  a  bow  or  bent 
ashen  staff,  from  5  to  7  feet  long,  having  a  strong  catgut  string  stretched  over  a  bridge 
at  each  end,  and  suspended  at  its  middle  by  a  cord  to  the  ceiling,  so  as  to  hang  nearly 
level  with  the  work-bench,  and  a  small  space  above  it.  The  wool  and  coarser  fur  are 
laid  in  their  somewhat  matted  state  upon  this  bench,  when  the  bower,  grasping  the  bent 
rod  with  his  left  hand,  and  bij  means  of  a  small  wooden  catch  plucking  the  string  with  his 
right,  makes  it  vibrate  smartly  against  the  fibrous  substances,  so  as  to  disentangle  them, 
toss  them  up  in  the  air,  and  curiously  arrange  themselves  in  a  pretty  uniform  layer  or 
fleece.  A  skilful  bower  is  a  valuable  workman.  The  bowed  materials  of  one  hat  are 
spread  out  and  divided  into  two  portions,  each  of  which  is  compressed,  first  with  a  light 
wicker  frame,  and  next  under  a  piece  of  oil  cloth  or  leather,  called  a  hardening  skin, 
till  by  pressing  the  hands  backward  and  forward  all  over  the  skin,  the  filaments  are 
linked  together  by  their  serrations  into  a  somewhat  coherent  fleece  of  a  triangular  shape. 
The  two  halves  or  "  bats"  are  then  formed  into  a  cap ;  one  of  them  is  covered  in  its 
middle  with  a  3-cornered  piece  of  paper,  smaller  than  itself,  so  that  its  edges  may  be 
folded  over  the  paper,  and  by  overlapping  each  other  a  little,  form  a  complete  envelope 
to  the  paper;  the  junctions  are  then  partially  felted  together  by  rubbing  them  hard, 
care  being  taken  to  keep  the  base  of  the  triangle  open  by  means  of  the  paper ;  the  sec- 
ond bat  being  made  to  enclose  the  first  by  a  similar  process  of  folding  and  friction. 
This  double  cap,  with  its  enclosed  sheet  of  paper,  is  next  rolled  up  in  a  damp  cloth  and 
kneaded  with  the  hands  in  every  direction,  during  which  it  is  unfolded  and  creased  up 
again  in  different  forms,  whereby  the  two  layers  get  thoroughly  incorporated  into  one 
body ;  thus,  on  withdrawing  the  paper,  a  hollow  cone  is  obtained.  The  above  opera- 
tions have  been  partially  described  in  the  body  of  the  Dictionary,  and  the  remaining 
steps  in  making  a  hat  are  there  sufficiently  detailed. 

In  a  great  hat  factory  women  are  employed,  at  respectable  wages,  in  plucking  the 
beaver  skins,  cropping  off  the  fur,  sorting  various  qualities  of  wool,  plucking  and  cutting 
rabbit's  fur,  shearing  the  nap  of  the  blocked  hat,  picking  out  unseemly  filaments  of  fur, 
and  in  trimming  the  hats ;  that  is,  lining  and  binding  them. 

The  annual  value  of  the  hats  manufactured  at  present  in  the  United  Kingdom  is 
estimated  at  3,000,000/.  sterling.  The  quantity  exported  in  1840,  was  22,522  dozens, 
valued  at  81,583/. 

With  regard  to  the  stiffening  of  hats,  I  have  been  furnished  ^ya  skilful  operator  with 
the  following  valuable  information:  "All  the  solutions  of  gums  which  I  have  hitherto 
seen  prepar^  by  hatters,  have  not  been  perfect,  but,  in  a  ceitain  degree,  a  mixture,  more 
or  less,  of  the  gums,  which  are  merely  suspended,  owing  to  the  consistency  of  the  com- 
position.   When  this  is  thinned  by  the  addition  of  spirit,  and  allowed  to  stand,  it  lets 


fall  a  curdy-looking  sediment,  and  to  this  circumstance  may  be  ascribed  the  frequent 
breaking  of  hata.  My  method  of  proceeding  is,  first  to  dissolve  the  gums  by  agitation  in 
twice  the  due  quantity  of  spirits,  whether  of  wood  or  wine,  and  then,  after  complete  solu- 
tion, draw  off  one-half  the  spirit  in  a  still,  so  as  to  bring  the  stiffening  to  a  proper 
consistency.  No  sediment  subsequently  appears  on  diluting  this  solution,  however  much 
it  may  be  done. 

"Both  the  spirit  and  alkali  stiffenings  for  hats  made  by  the  following  two  recipes, 
have  been  tried  by  some  of  the  first  houses  in  the  trade,  and  have  been  much 
approved  of : — 

Spirit  Stiffening. 

1  pounds  of  orange  shellac. 

2  pounds  of  gum  sandarac. 
4  ounces  of  gum  mastic. 
Half  a  pound  of  amber  rosin. 
1  pint  of  solution  of  copaL 

1  gallon  of  spirit  of  wine  or  wood  naphtha. 

"  The  shellac,  sandarac,  mastic,  rosin,  are  dissolved  in  the  spirit,  and  the  solution  of 
copal  is  added  last 

Alkali  Stiffening. 

7  pounds  of  common  block  shellac. 

1  pound  of  amber  rosin. 

4  ounces  of  gum  thus. 

4  ounces  of  gum  mastic 

6  ounces  of  borax. 

Half  a  pint  of  solution  of  copal. 

"  The  borax  is  first  dissolved  in  a  little  warm  water  (say  1  gallon) ;  this  alkaline  liquor 
is  now  put  into  a  copper  pan  (heated  by  steam),  together  with  the  shellac,  rosin,  thus,  and 
mastic,  and  allowed  to  bod  for  some  time,  more  warm  water  being  added  occaeionally 
until  it  is  of  a  proper  consistence ;  this  may  be  known  by  pouring  a  little  on  a  cold  slab 
somewhat  inclined,  and  if  the  liquor  runs  off  at  the  lower  end,  it  is  sufficiently  fluid ;  if, 
on  the  contrary,  it  set  before  it  reaches  the  bottom,  it  requires  more  water.  When  the 
whole  of  the  gums  seem  dissolved,  half  a  pint  of  wood  naphtha  must  be  introduced,  and 
the  solution  of  copal ;  then  the  liquor  must  be  passed  through  a  fine  sieve,  and  it  will  be 
perfectly  clear  and  readv  for  use.  This  stiffening  is  used  hot.  The  hat  bodies,  before 
they  are  stiffened,  should  be  steeped  in  a  weak  solution  of  soda  in  water,  to  destroy  any 
acid  that  may  have  been  left  in  them  (as  sulphuric  acid  is  used  in  the  making  of  the 
bodies).  If  this  is  not  attended  to,  should  the  hat  body  contain  any  acid  when  it  is  dipped 
into  the  stiffening,  the  alkali  is  neutralized,  and  the  gums  consequently  precipitated. 
After  the  body  has  been  steeped  in  the  alkaline  solution,  it  must  be  perfectly  dried  in 
the  stove  before  the  stiffening  is  applied ;  when  stiffened  and  stoved  it  must  be  steeped 
all  night  in  water,  to  which  a  small  quantity  of  sulphuric  acid  has  been  added ;  this  set* 
the  stiffening  in  the  hat  body,  and  finishes  the  process.  A  good  workman  will  stiffen  15 
or  16  dozen  hats  a  day.  If  the  proof  is  required  cheaper,  more  shellac  and  rosin  must 
be  introduced." 

HEALDS,  is  the  harness  for  guiding  the  warp  threads  in  a  loom;  that  is,  for  lifting  a 
certain  number  of  them  alternately  to  open  the  shed,  and  afford  passage  to  the  decussating 
weft  threads  of  the  shuttle.    See  Weaving. 

HEARTH ;  {Foyers  Fr. ;  Heerde,  Germ.)  is  the  flat  or  hollow  space  in  a  smelting  fur- 
nace uptm  which  the  ore  and  fluxes  are  subjected  to  the  influence  of  flame.  See  CorrEii, 
Irov,  Mktallurgt,  <fec. 

HEAT,  is  that  power  or  essence  called  caloric,  the  discussion  of  whose  habitudes  with 
the  different  kinds  of  matter  belongs  to  the  science  of  chemistry. 

HEAT- REGULATOR.  The  name  given  by  M.  Bonnemain  to  an  ingenious  apparatus 
for  regulating  the  temperature  of  his  incubating  stove  rooms.  See  Incubation,  Artificial, 
fur  the  manner  of  applying  the  Heat- Regulator. 

The  construction  of  the  regulator  is  founded  upon  the  unequal  dilatations  of  different 
metals  by  the  same  degree  of  heat.  A  rod  of  iron  x,  fig.  758.,  is  tapped  at  its  lower  end 
into  a  brass  nut  y,  enclosed  in  a  leaded  box  or  tube,  terminated  above  by  a  brass  collet  z. 
This  tube  is  plunged  into  the  water  of  the  boiler,  alongside  of  the  smoke  pipe. 
{Fig.  759.  is  a  bird's-eye  view  of  the  dial,  Ac.)  The  expansion  of  the  lead  being 
more  than  the  iron  for  a  like  degree  of  temperature,  and  the  rod  enclosed  within 
the  tube  being  less  easily  warmed,  whenever  the  hesit  rises  to  the  desired  pitch,  the 
elongation  of  the  tube  puts  the  collet  z  in  contact  with  the  heel  o,  of  the  bent  lev^r 


1004 


HEAT-REGULATOR. 


a,  6.  rf;  thence  the  slightest  increase 
of  heat  lengthens  the  tube  anew 
and  the  collet  lifting  the  heel  of 
the  lever,  depresses  the  other  end 
d  through  a  much  greater  space, 
on  account  of  the  relative  lensrths 
of  its  legs.  This  movement  ope- 
rates near  the  axis  of  a  balance  bar 
e,  sinks  one  end  of  this,  and  there- 
by increases  the  extent  of  the  move- 
ment which  is  transmitted  directly 
to  the  iron  skewer  v.  T\us  push- 
ing down  a  swing  register  dimi- 
nishes or  cuts  oflF  the  access  of  air 
to  the  fire-place.  The  combustion 
is  thereby  obstructed,  and  the  tem- 
perature falling  by  deu:ree8,  the  tube  shrinks  and  disengages  the  heel  of  the  lever.  The 
counterpoise  g,  fixed  at  the  balance-beam  e,  raises  the  other  extremity  of  this  beam  by 
raising  the  end  d  of  the  lever  as  much  as  is  necessary  to  make  the  heel  bear  upon  the 
collet  of  the  tube.  The  swing  register  acted  upon  by  this  means,  presents  a  greater 
section  to  the  passage  of  the  air ;  whence  the  combustion  is  increased.  To  counter- 
balance the  effect  of  atmospheric  changes,  the  iron  stem  which  supports  the  regulator 
is  terminated  by  a  dial  disc,  round  the  shaft  of  the  needle  above  h,Jiff.  759. ;  on  turning 
this  needle,  the  stem  below  it  turns,  as  well  as  a  screw  at  its  under  end,  which  raises  or 
lowers  the  leaden  tube.  In  the  first  case,  tlie  heel  falls,  and  opens  the  swing  register, 
whence  a  higher  temperature  is  required  to  shut  it,  by  the  expansion  of  the  tube.  We 
may  thus  obtain  a  regularly  higher  temperature.  If,  on  the  contrary,  we  raise  the  tube 
by  turning  the  needle  in  the  other  direction,  the  register  presents  a  smaller  opening,  and 
shuts  at  a  lower  temperature ;  in  this  case,  we  obtain  a  regularly  lower  temperature. 
It  is  therefore  easy,  says  M.  Bonnemain,  to  determine  d  priori  the  degree  of  temperature 
to  be  given  to  the  water  circulating  in  the  stove  pipes.  In  order  to  facilitate  the  regula- 
tion of  the  apparatus,  he  graduated  the  disc  dial,  and  inscribed  upon  its  top  and  bottom, 
the  words,  Strong  and  Weak  heat.     See  Thermostat,  for  another  Heat-Regulator. 

HEAVY-SPAR,  sulphate  of  Baryta,  or  Cawk ;  (Spath  pesant,  Fr. ;  Schwerspat?i, 
Germ.)  is  an  abundant  mineral,  which  accompanies  veins  of  lead,  silver,  mercury,  Ac, 
but  is  often  found,  also,  in  large  masses.  Its  colour  is  usually  white,  or  flesh  coloured. 
It  occurs  in  many  crystalline  forms,  of  which  the  cleavage  is  a  right  rhomboidal  prism. 
It  is  met  with  also  of  a  fibrous,  radiated,  and  granular  structure.  Its  spec.  grav.  varies 
from  41  to  46.  It  has  a  strong  lustre,  between  the  fatty  and  the  vitreous.  It  melts  at 
35°  Wedgw.  into  a  white  opaque  enamel.  Its  constituents  are  6563  baryta,  and 
34*37  sulphuric  acid.  It  is  decomposed  by  calcination  in  contact  with  charcoal  at  a 
white  heat,  into  a  sulphuret  of  baryta  ;  from  which  all  the  baryta  salts  may  be  readily 
formed.  Its  chief  employment  in  commerce  is  for  adulterating  white  lead ;  a  purpose 
which  it  readily  serves  on  account  of  its  density.  Its  presence  here  is  easily  detected  by 
dilute  nitric  acid,  which  dissolves  the  carbonate  of  lead,  and  leaves  the  heavy  spar.  It 
is  also  a  useful  ingredient  in  some  kinds  of  pottery,  and  glass. 

HECKLE;  {Seran^  Fr. ;  Hechel,  Germ.)  is  an  implement  for  dissevering  the  fila- 
ments of  flax,  and  layiug  them  in  parallel  stricks  or  tresses.     See  Flax. 

HELIOGRAPHY  may  be  regarded  as  the  appropriate  title  of  the  new  and  elegant 
art  of  making  sun  pictures ;  an  art  which  originated  with  Niepce  and  Daguen'e,  and 
which  has  been  much  improved  by  Mr.  Fox  Talbot.  See  the  articles  Calotype  and  Da- 
guerreotype. It  has  been  called  photography,  bemg  a  picture  produced  by  the  action 
of  light ;  but  as  the  sunbeams  are  essential  to  a  good  result,  I  have  called  it  Heliogr<iphy. 
Iodide  of  silver  is  the  principal  agent  applied  to  paper,  to  make  it  very  sensible  to  the 
impressions  of  the  sunbeam.  The  bromiue  has  also  been  used,  and  preferably  in  mix- 
ture. Le  Gray  in  his  new  treatise  of  photography,  lately  published,  recommends  a 
mixture  of  the  Iodide,  cyanide  and  fluoride,  as  the  excitable  fluid  ;  this  compound  being 
used  in  union  with  potassium.  The  paper  thus  impregnated,  is  laid  on  the  aceto-nitrate 
of  silver,  and  then  exposed  to  the  light.  A  picture  may  thus  be  obtained  in  the  focus 
of  the  camera  obscura  in  30  seconds  in  fine  weather ;  a  circums^nce  of  great  conse- 
quence in  taking  living  portraits,  on  account  of  the  mobility  of  theniuman  countenance. 
Waxed  paper  applied  dry  possesses  a  like  sensibility. 

One  of  the  main  difficulties  in  heliography  lies  in  the  choice  of  the  paper.     The  post 

paper  of  Whatman  of  London,  is  preferred  for  the  preliminary  trials,  when  it  is  slightly 

glazed.     Thin  paper  is  better  for  jwrtraiture,  and  thick  for  landscapes.     Well  sized  paper 

'i3  to  be  preferred,  and  of  equal  texture. 

.The  first  step  in  preparing  the  paper,  is  to  fill  up  all  its  pores  with  fine  white-wax. 


HELIOGRAPHY. 


1005 


and  thus  give  it  the  aspect  of  parchment.  Provide  a  large  plate  of  silver-plated,  as  for 
the  daguerreotype  process,  place  it  on  a  tripod  horizontally,  heat  it  by  passing  the  flame 
of  a  spirit  of  wine  lamp  to  and  fro  under  it,  or  rather  set  it  over  a  water  bath,  while  with 
the  other  hand  a  piece  of  white  wax  is  rubbed  over  it.  The  coat  of  wax  being  equally 
fused,  lay  the  paper  upon  it,  and  cause  it  to  apply  evenly  by  putting  a  card  on  it.  It  is 
then  to  be  removed,  and  laid  between  two  or  three  folds  of  blotting  paper,  and  gently 
pressed  over  with  a  hot  smoothing  iron,  to  remove  the  excess  of  wax.  It  is  indispensable 
that  no  wax  remain  on  the  surface,  but  only  in  the  texture  of  the  paper ;  which  should 
have  no  glistening  spot,  and  be  perfectly  transparent.  Thin  paper  should  be  preferred 
for  waxing.  Well  prepared  paper  should  allow  the  proof  of  the  picture  to  develop 
itself  in  the  gallic  acid  for  a  considerable  time,  without  spotting  either  the  proof  or  the 
acid.  Its  principal  quality  is,  to  permit  the  aceto-nitrate  of  silver  to  be  prepared  before- 
liand,  and  thus  have  a  store  of  ready  waxed  paper.  This  preparation  aflfords  very  intense 
blacks  upon  thin  papers. 

The  bath  of  iodide  of  potassium  completely  penetrates  the  wax,  and  deprives  it  of  its 
greasy  aspect,  by  a  sort  of  decomposition,  which  causes  the  subsequent  preparations  to 
apply  uniformly.  This  paper  should  be  left  from  half  an  hour  to  an  hour,  in  the  solution 
of  the  iodide,  according  to  the  thickness  of  the  paper ;  to  ensure  the  decomposition  of  the 
wax,  care  must  be  taken  to  keep  the  waxed  paper  cool.  The  iodized  paper  assumes  a 
violet  tint  when  completely  dry.  This  hue,  resulting  from  the  union  of  the  wax  with  the 
iodine,  is  beneficial,  because  it  affords  sufficient  time  to  leave  the  paper  on  the  acetf>- 
nitrate  of  silver,  till  the  violet  tint  disappears.  The  preparations  that  follow  may  be 
applied  to  either  the  waxed  or  plain  paper ;  but  in  the  latter  case,  the  paper  should  be 
somewhat  thick. 

First  Preparation. — Negative  Paper.— BoW  in  a  porcelain  or  earthen  pan,  3  litres  of 
distilled  water,  with  250  grammes  of  rice,  till  this  merely  bursts,  lest  the  water  become* 
too  glutinous.  Strain  through  calico.  Tliis  forms  an  excellent  size,  and  affords  a  g«K>d 
body  and  fine  blacks.  In  a  litre  of  the  above  rice  water,  dissolve  40  grammes  of  sugar 
of  milk  ;  15  of  iodide  of  potassium ;  80  centigrammes  of  cyanide  of  potassium,  and  50  cen- 
tigrammes of  fluoride  of  potassium.  Filter  the  solution,  and  set  aside  for  use  in  a  bottle. 
To  prepare  the  paper,  pour  this  solution  into  a  large  plate,  and  plunge  the  waxed  paper 
into  it,  leaf  by  leaf  over  each  other,  taking  care  to  expel  the  air  bubbles.  Take  them  out, 
return  them  for  about  half  an  hour  ;  then  hang  them  up  to  dry,  by  means  of  a  bent  pin 
hooked  to  the  corner ;  and  favour  their  drainage  by  placing  a  bit  of  blotting  paper  on 
their  lower  point  This  process  is  to  be  repeated.  French  and  English  papers  should 
not  be  mixed  in  the  same  cistern.  The  English  paper  is  said  to  contain  a  free  acid,  which 
precipitates  iodide  of  starch  in  the  French  paper,  and  gives  it  a  deep  violet  tint.  The 
paper  is  to  be  cut  down  to  the  size  of  the  camera  obscura,  and  put  up  for  use  in  a  porte- 
feuille.  The  liquid  which  has  been  used  will  serve  again.  The  paper  thus  prepared,  is 
called  iodized. 

Paper  spceially  for  Portraiture — is  prepared  as  follows.  Take  400  grammes  of  dis- 
tilled water,  20  of  iodide  of  potassium,  2  of  cyanide  of  potassium,  0-50  centigrammes  of 
fluoride  of  potassium  ; — dissolve.  Pour  2  or  3  millimetres  of  this  solution  into  a  flat  plate 
of  porcelain,  or  on  a  flat  glass,  quite  horizontal.  Take  a  piece  of  glazed  paper  by  the 
two  corners,  the  rough  side  uppermost,  and  apply  the  smooth  fiice  upon  the  liquid  in 
the  plate ;  beginning  the  immersion  with  the  side  next  your  body,  and  pushing  the  leaf 
before  you,  so  that  it  may  always  fall  at  right  angles  upon  the  liquid.  Tliis  movement  is 
to  be  repeated  two  or  three  times,  so  as  to  press  out  any  air  bubbles.  Take  care  that  the 
liquid  does  not  pass  to  the  other  side  of  the  paper.  It  is  to  remain  on  the  bath  not  more 
than  two  minutes  at  most.  It  is  then  to  be  lifted  and  perfectly  dried  between  folds  of 
blotting  paper,  of  a  fine  tissue,  rubbing  it  in  all  directions  with  the  hands,  and  changing 
its  place,  that  it  may  be  perfectly  dry.  Remove  the  paper  and  smooth  it  with  a  soft 
brush.  Lay  the  same  side  upon  the  bath  of  aceto-nitrate  of  silver  (about  to  be  indicated) ; 
leaving  it  there  not  more  than  8  or  10  seconds  at  most,  and  then  place  it  upon  the  slate 
in  the  camera,  (which  has  been  previously  furnished  with  a  leaf  of  blotting  jxiper  well 
Boaked  in  water,  as  will  be  described  further  on.  It  is  requisite  to  make  immediate  use 
of  this  paper,  because  its  great  sensibility  depends  chiefly  on  the  nascent  state  of  the 
iodide  of  silver  that  it  operates  upon.  In  summer,  from  4  to  10  seconds  are  required  for 
an  impression  ;  in  winter,  from  18  to  40. 

The  second  operation  is  to  give  sensibility  to  the  iodized  papers,  either  in  the  dry  or 
humid  wav.    Take  of 


-  150  grammes 

-  5        " 


Distilled  water        .  -  - 

Crystallized  nitrate  of  silver 

When  this  is  dissolved,  add  of  crystallizable  acetic  acid  12  grammes.  Care  must  be 
taken  to  prepare  this  solution  by  the  light  of  a  feeble  taper,  and  to  surround  the  phial 
with  a  case  of  blackened  paper.    No  more  of  this  mixture  should  be  put  into  the  cap. 


1006 


HELIOGRAPHY. 


fiule  than  is  suflSeient  for  once.    If  not  to  be  kept  more  than  4  days  upon  the  paper,  the 
following  mixture  may  be  used : 


Distilled  water 
Acetate  of  silver 
Crystallizable  acetic  acid 


150  grammes 
10 
12        " 


For  the  humid  operation  the  paper  may  preferably  be  employed  moist.  At  the  moment 
of  commencing,  pour  one  of  those  mixtures  of  aceto-nitrate  of  silver  upon  a  plate  of 
porcelain  or  glass,  quite  horizontal,  to  about  one  millimetre  in  depth.  A  pipette  or  email 
sucking  glass  tube  is  convenient  for  this  purpose,  as  its  fine  point  prevents  any  drops 
from  being  spilled  irregularly.  And  the  surface  of  the  liquid  may  be  skimmed  if  neces- 
sary with  a  piece  of  white  paper.  The  leaf  of  iodized  paper  is  now  to  be  seized  by  the 
two  corners  on  the  side  only  which  was  iodized,  and  to  be  laid  down  and  raised  several 
times  so  as  to  expel  the  air.  This  may  be  done  with  the  thumb  by  the  help  of  a  pallet 
ivory  knife  to  save  staining  the  fingers.  Take  care  that  none  of  the  nitro-acetate  of  silver 
goes  on  the  other  side  of  the  paper.  Allow  the  paper  to  receive  the  chemical  action  till 
the  formation  of  a  very  sensible  layer  of  cyano-iodo-fluoride  of  silver.  Five  minutes  may 
suffice  for  the  French  paper,  and  a  little  longer  for  the  English  ;  both  being  imbued  with 
the  sugar  of  milk  preparations.  Time  should  be  given  for  the  violet  hue  to  disappear, — 
4  or  5  minutes ;  but  with  the  portrait  paper,  9  or  10  seconds  should  be  sufficient.  The 
longer  this  interval  the  less  is  the  sensibility. 

Apply  the  paper  quite  moist  upon  a  slate,  on  which  there  has  been  previously  spread 
to  receive  it,  a  well  soaked  leaf  of  unsized  paper.  The  sole  of  the  camera  may  also  be 
made  use  of,  if  it  has  been  well  covered  with  a  coat  of  white  wax.  But  the  slate  is 
preferable  ;  care  being  had  to  lay  the  surface  with  the  aceto-nitrate  uppermost  to  receive 
the  radiations  of  light.  The  undermost  piece  of  paper  should  be  free  from  iron  stains. 
The  slate  should  be  marked  so  as  to  be  preserved  always  in  one  posture,  both  when  they 
are  applied  and  when  put  up  in  the  frame.  If  these  precautions  be  neglected,  the 
liquid  collects  below  and  falls  upon  the  prepared  paper,  and  may  cause  spots.  The 
paper,  when  thus  put  on  the  slate,  may  be  left  there  for  three  or  four  hours  without 
being  removed,  and  may  be  placed  during  this  interval  in  the  camera.  On  going  a 
little  way  off  to  take  a  proof,  the  fold  of  the  leaf  may  be  dipped  in  thick  mucilage  of 
gum-arabic,  which  serves  to  preserve  the  moisture  and  the  adhesion.  Two  panes  of  glass 
may  also  be  used  for  laying  the  papers  between  ;  not  sparing  blotting  paper  in  cleaning 
them. 

In  the  dry  way,  waxed  paper  is  to  be  used.  It  will  require  more  time  to  develop  the 
image  with  the  gallic  acid  ;  but  this  comes  out  equally  well,  only  there  will  be  a  pretty 
strong  contrast  between  the  whites  and  the  blacks.  The  aceto-gallic  acid,  and  the  aceto- 
nitric,  which  are  added  should  be  fresh,  extremely  pure,  and  well  filtered.  Two  porcelain 
basins  of  some  depth  are  to  be  taken ;  into  the  first  put  from  5  to  6  millimetres  of  accto- 
nitric  acid  (noted  above)  and  into  the  second  put  distilled  water.  Plunge  completely  on 
the  two  sides  the  waxed  and  iodized  paper,  into  the  bath  of  the  aceto-nitrate  of  silver  of 
the  first  cistern,  and  leave  it  there  4  or  5  minutes,  then  transfer  it  immediately  into  the 
bath  of  distilled  water  in  the  second  cistern,  and  leave  it  at  least  4  minutes  or  more  if  you 
wish  to  keep  the  paper  some  time  before  using  it.  You  may  prepare  next  in  the  same 
baths,  ten  leaves  one  after  the  other.  Lastly,  the  paper  is  to  be  taken  from  the  water  to 
be  dried  between  folds  of  blotting  paper,  and  laid  by  in  a  blotting-book  equally  dry. 
The  paper  is  not  to  be  dried  by  suspension  in  the  air.  Kept  in  the  dark  the  paper  will 
thus  keep  its  qualities  fully  5  days,  before  going  into  the  camera  The  aceto-nitrate  of 
silver  deteriorates  after  8  days.  It  is  good  not  to  put  at  once  more  than  one  or  two  proofs 
into  the  same  bath  of  gallic  acid.  The  period  of  exposure  in  the  camera  is  not  longer  in 
the  dry  than  in  the  humid  way,  but  the  proof  must  stand  a  little  longer  in  the  gallic 
acid,  which  may  have  15  or  20  drops  added  to  it  of  the  nitro-acetate  of  silver  filtered,  and 
fresh  made,  or  not  previously  used.  The  granular  and  soiled  look  of  the  paper  under  the 
gallic  acid  when  it  Decomes  dry,  should  give  no  concern,  as  it  disappears  completely  on 
re-melting  the  wax,  of  the  proof  on  the  exposure  of  its  negative  to  a  suitable  heat.  This 
precaution  should  never  be  neglected,  for  it  is  superior  to  any  varnish.  These  operations 
being  finished,  invert  the  aceto-nitrate  of  silver  into  a  phial,  but  don't  reserve  any  for 
fresh  proofs,  which  would  prove  a  constant  cause  of  failures.  It  may  be  thrown  down 
by  common  salt,  in  the  state  of  chloride  of  silver,  which  serves  to  give  to  hyposulphite  of 
soda,  the  quality  necessary  for  producing  fine  tones.  The  aceto-nitrate  may  be  decoloured 
and  revived  by  means  of  bone  black,  with  which  it  is  to  be  boiled  a  short  time  and  then 
filtered. 

Third  Operation :  Exposure  in  the  Camera. — Place  the  point  of  the  image  in  the  de- 
polished  glass  most  scrupulously  in  the  middle  <»f  the  lens.  After  the  exposure  to  the 
luminous  rays  the  image  in  the  camera  has  little  appearance,  being  developed  only  by 


HELIOGRAPHY. 


1007 


the  subsequent  operation,  which  may  be  performed  some  hours  afterwards,  on  the  moist 
paper,  or  even  some  days  with  the  waxed  paper  in  the  dry  state. 

Development  of  the  Image. — This  is  effected  by  the  gallic  acid  diluted  with  pure  water, 
in  the  proportion  of  1  litre  of  the  latter  and  4  grammes  of  the  former.  Pour  out  of  this 
solution  into  a  horizontal  flat  shallow  plate,  to  the  thickness  of  3  or  4  millimetres. 
Plunge  the  proof  completely  into  it,  so  that  it  may  be  covered  all  round.  Watch  its 
development,  which  is  readily  perceived  across  the  thickness  of  the  paper.  It  may  be 
left  here  from  10  minutes  for  an  hour  or  two,  till  it  be  arrived  at  perfection.  The 
development  is  much  quickened  by  adding  20  or  21  drops  of  aceto  nitrate  of  silver, 
when  the  image  begins  to  appear.  Very  intense  blacks  are  thus  obtained,  but  the  action 
must  then  be  followed  up,  because  it  is  rapid,  and  it  gives  such  intense  blacks,  as  to  be 
disagreeable  if  the  time  be  prolonged.  When  it  is  sufficiently  deep,  withdraw  it  smartly, 
and  pour  several  streams  of  water  over  it,  upon  a  plate  or  dish,  rubbing  the  back  of  the 
paper  at  the  same  time  with  a  finger  to  remove  any  crystalline  grains  which  might  spoil 
it.  The  gray  hue  of  the  waxed  paper  need  cause  no  alarm  as  it  disappears,  and  leaves 
beautiful  whites  and  blacks.  The  tone  which  the  image  takes  from  the  gallic  acid  will 
enable  you  to  judge  whether  the  exposure  to  the  light  has  been  adequate.  If  it  becomes 
immediately  of  a  gray  black  everywhere  (looked  well  through),  it  shows  it  to  have  been 
too  long  under  the  light.  If  the  greatest  lights,  which  should  be  the  greatest  blacks 
of  the  negative,  do  not  become  deeper  than  the  semi-tints,  the  exposure  has  also  been 
too  long.  A  first  proof  serves  to  regulate  the  time  of  exposure  in  the  camera  for  the 
rest.  Its  period  may  be  shortened  by  warming  the  gallic  acid,  for  which  a  little  appa- 
ratus has  been  used,  consisting  of  a  little  square  copper  basin  filled  with  water,  supported 
over  a  small  spirit  lamp,  which  communicates  heat  to  the  shallow  dish  containing  the 
gallic  acid,  <!i;c 

The  picture  taken  as  above  described  will  not  be  permanent.  It  must  be  fixed  by 
the 

Fifth  Operation^  or  that  of  the  Negative  Proof. — Dissolve  in  a  bottle  100  grammes  of 
hyposulphite  of  soda  in  800  grammes  of  filtered  water.  Put  the  solution  into  a  basin  to 
the  depth  of  half  a  centimetre,  and  plunge  the  negative  proof  completely  in  it,  taking 
care  to  free  it  from  air  bubbles.  The  hyposulphite  takes  possession  of  the  cyano-iodo- 
fluoride  of  silver,  and  the  proof  remains  clear  ;  but  it  does  not  affect  the  gallate  of  silver, 
which  on  the  contrary  continues  black.  Never  put  more  than  one  proof  at  a  time  in  this 
bath;  but  you  may  put  several  proofs  in  it  one  after  the  other.  The  hyposulphite  of  soda 
which  has  been  already  used  is  to  be  collected,  and  when  kept,  lets  fall  flocks  of  gallate 
of  iron  and  sulphuret  of  silver.  When  filtered  it  serves  well  for  fixing  weak  proofs.  On 
examining  the  proof  after  it  has  remained  some  time  in  the  bath,  we  might  be  tempted 
to  believe  that  it  has  lost  its  strength  from  its  transparency,  because  the  iodide  of  silver, 
which  has  a  straw  yellow  tint,  being  completely  removed  from  its  place  and  resting  at 
other  spots,  annihilates  the  image  in  appearance.  But  if  we  consider  that  the  whole 
iodide  of  silver  is  removed,  as  is  recognized  when  the  yellow  tint  of  the  proof  is  also 
gone — one  becomes  astonished  at  the  whiteness  and  the  transparency  of  the  paper ;  aa 
well  as  the  beauty  of  the  blacks  of  the  image. 

For  these  effects  it  requires  from  half  an  hour  to  three  quarters  of  an  hour  with  the 
ordinary  papers.  An  abode  of  too  much  length  in  the  bath  weakens  the  blocks  of  the 
proof;  and,  therefore,  this  process  should  be  looked  after.  With  waxed  papers,  from  10 
to  15  minutes  are  sufficient  for  fixing.  The  proof  is  to  be  next  washed  with  several 
waters,  and  left  to  drain  off  its  hyposulphite  into  a  basin  for  the  space  of  half  an  hour.  It 
is  then  dried  by  hanging  it  up  by  a  corner  ;  and  is  now  inalterable  at  the  light,  since  there 
does  not  remain  any  more  in  the  paper  than  the  black  gallate  of  iron. 

Sixth  Operation :  Waxing  of  the  Negative  Proof — When  the  negative  proof  is  weak 
and  the  paper  very  transparent,  counterproofs  should  be  made  with  it  without  waxing. 
The  proofs  obtained  from  paper  previously  waxed  should  not  be  waxed  anew,  but  only 
approached  near  the  fire  to  restore  their  transparency,  which  they  had  lost  by  their  suc- 
cessive baths.  Before  this  operation  they  have  a  granular  aspect.  The  negative  proof 
should  be  waxed,  which  counteracts  the  ill  effect  of  any  of  the  nitrate  of  silver  remaining 
on  the  surface  of  the  positive  paper.  The  waxing  of  the  negative  proof  is  done  by  melting 
with  a  spirit  lamp  a  layer  of  white  wax  on  a  piece  of  plated  copper  like  that  of  a 
daguerreotype,  laying  the  negative  ujwn  it,  and  promoting  its  adhesion  by  the  weight  of 
a  card.  When  it  is  equally  soaked,  place  it  between  folds  of  smooth  writing  paper,  and 
glide  a  hot  smoothing  iron  over  all  to  remove  the  excess  of  wax.  The  iron  should  not  be 
too  hot. 

Seventh  Preparation  ;  that  of  Positive  Paper. — Saturate  a  bottle  of  water  with  sea 
salt  Dilute  1  part  of  this  solution  with  3  parts  of  water.  Put  into  a  plate  this  brine  to 
the  depth  of  4  or  5  millimetres.  Into  another  bottle  put  of  distilled  water  100  grammes ; 
crystallized  nitrate  of  silver  20  grammes.  Dissolve.  Of  which  pour  out  into  a  plate  to 
the  above  thickness. 


1008 


HELTOGRAPHY. 


HEPAR. 


1009 


Take  stout  paper  weighing  about  15  kilonfiammes  the  ream,  previously  cut  of  a  suita* 
ble  size,  and  free  from  iron  stains  or  any  impurities.  Mark  a  cross  on  the  side  of  the 
paper  which  bears  the  metallic  mark  of  the  manufacturer.  Le  Gray  says  the  English 
paper  should  not  be  used  unless  a  red  tone  be  wanted  in  the  pictures.  Place  the  paper 
upon  a  plate  of  porcelain  or  glass  moistened  (as  formerly  directed)  with  the  dilute  brine, 
and  leave  it  there  from  2  to  4  minutes ;  dry  it  between  folds  of  pink  blotting  paper, 
rubbing  it  at  the  same  time  with  the  hand.  Prepare  thus  3  leaves  before  beginning,  to 
put  them  in  the  bath  of  nitrate  of  silver,  in  order  that  all  traces  of  humidity  may  be  re- 
moved. Take  the  dried  leaves  and  clear  them  by  a  somewhat  hard  flat  brush  from  all 
particles  of  salt  or  other  impurities.  Put  a  leaf  of  the  pink  blotting  paper  upon  the 
nitrate  of  silver  of  the  salted  side  only,  and  leave  it  there  the  time  requisite  to  prepare 
another  leaf  upon  the  salt.  By  leaving  it  for  a  little  on  the  nitrate  of  silver,  red  tones 
are  obtained ;  but,  by  leaving  it  longer,  blacker  tones.  The  paper  is  then  to  be  dried, 
hanging  it  up  by  a  comer;  but  all  must  be  done  by  candlelight.  The  positive  paper 
should  be  very  dry  before  laying  a  negative  upon  it,  for  fear  of  staining  it  with  nitrate 
of  silver.  On  this  account  it  is  good  to  dry  it  well  the  previous  night,  but  not  too  many 
days  beforehand,  lest  the  silver  should  darken. 

Eighth  Operation :  Taking  the  Positive  Proof. — Put  the  negative  upon  one  of  the 
glasses  of  the  frame  of  reproduction,  lay  above  it  a  leaf  of  glazed  paper,  then  one  of 
positive  paper  prepared  by  the  preceding  operation,  the  side  of  the  preparation  upon  the 
place  of  the  negative,  then  lay  above  it  a  leaf  of  black  paper,  and  the  second  glass  of  the 
frame.  Shut  the  cover  of  the  frame,  which  will  exert  a  slight  pressure  upon  the  glasses, 
and  secure  their  contact.  A  sheet  of  transparent  and  waxed  paper,  or  a  piece  of  papier 
glage  in  gelatine,  should  be  placed  between  the  negative  proof  and  the  leaf  of  the  positive 
paper.  This  does  not  hurt  the  nicety  of  the  proof,  and  preserves  the  negative  from 
contact  with  the  nitrate  of  silver,  which  would  spoil  it.  It  is  proper  to  allow  one  of  the 
sides  of  the  positive  paper  to  overlap  on  the  side  of  the  negative,  in  order  to  judge  of  the 
action  of  the  light.  Expose  the  frame  to  the  solar  or  diffuse  light,  so  that  the  rays  fall 
vertically  upon  the  surface  of  the  proof.  Trace  the  progress  of  the  proof  by  the  tone  of 
the  folded  over-part  of  the  paper,  as  per  the  following  gradations  of  tint :  Gray  blue,  neu- 
tral tint,  violet  blue,  black  blue,  black,  bistre,  coloured  sepia,  yellowish  sepia,  dead  leaf 
colour,  greenish-gray ;  always  wearing  away,  till  the  oxide  of  silver  be  at  last  reduced 
to  the  state  of  a  metallic  oxide.  It  is  proper  to  stop  at  some  one  of  these  tones,  accord- 
to  the  greater  or  less  vigour  of  the  negative,  and  the  depth  of  the  proof  that  is  desired. 
Once  we  have  obtained  a  proof  with  a  negative,  we  may  be  sure  when  we  stop  at 
the  same  tint  of  the  overlapping  edge,  we  shall  have  the  same  result.  To  have  a  proof 
of  a  black  tint,  for  example,  after  the  fixing  of  the  hyposulphite,  the  deep  parts  should 
have  the  tone  of  sepia,  and  the  parts  which  should  form  the  whites,  have  a  blue  gray,  on 
withdrawing  it  from  beneath  the  frame,  in  order  to  repair  the  loss  of  tone  given  by  the 
hyposulphite.  The  precise  time  of  the  exposure  to  the  light  cannot,  therefore,  be  fixed, 
and  is  subordinate  to  the  intensity  both  of  the  negative,  and  also  of  the  proof  which  is 
desired. 

Ninth  and  last  Operation :  Fixing  of  the  Positive  Proof. — This  proof  would  not  be 
permanent  without  being  immediately  fixed  by  the  following  process : 

Dissolve  in  a  bottle  100  grammes  of  hyposulphite  of  soda,  with  600  of  filtered  water; 
and  in  another  bottle  dissolve  5  grammes  of  nitrate  of  silver  in  a  couple  of  glas-ses  of 
water,  arid  add  a  solution  of  common  salt,  till  no  more  white  precipitate  falls.  After 
letting  it  settle  to  the  bottom  of  the  vessel,  collect  the  chloride  of  silver  in  a  piece  of 
calico,  and  put  it  into  the  preceding  solution  of  the  hyposulphite.  Thus,  black  tones 
may  be  obtained  with  this  new  hyposulphite.  The  older  this  hyposulphite  is  the  better. 
When  it  becomes  turbid,  a  little  more  fresh  solution  need  only  be  added  to  it.  We  must 
also  beware  of  filtering  it  to  remove  the  black  deposit  which  is  formed  ;  we  have  only  to 
let  it  remain  at  rest  in  a  large  bottle,  and  decant  the  clear  liquor  for  use,  so  as  not  to  lose 
the  black  deposit,  and  to  redissolve  it  by  means  of  fresh  hyposulphite.  By  means  of 
a  stay  shorter  or  longer  in  this  bath,  almost  all  the  tones  may  be  obtained  from  the  red 
to  the  black,  and  the  pale  yellow  ;  so  that,  with  a  little  practice,  any  desired  tint  may  be 
secured.  The  proof  should  be  left  in  the  bath  at  least  an  hour  to  be  sufliciently  fixed  ; 
and  it  may  remain  in  it  from  3  to  4  hours  to  bring  out  the  sepia  and  the  yellow  tones. 
By  heating  the  hyposulphite,  we  may  quicken  the  operation,  but  we  must  not  leave  the 
proof  an  instant  to  itself,  because  the  action  is  rapid,  and  the  picture  might  become 
effaced.  In  this  case  it  is  good  to  add  a  little  acetic  acid  to  the  hyposulphite,  in  order  to 
preserve  the  whites. 

On  adding  to  the  preceding  solution  of  the  hyposulphite  25  grammes  of  ammonia,  very 
pretty  bistre  tones  are  obtained  along  with  very  pure  whites.  English  paper  suits  these 
effects  very  well.  Very  fine  velvety  tones  are  obtained  by  putting  the  proof  (on  taking 
out  of  the  hyposulphite)  upon  a  bath  of  salt  of  gold  (1  gramme  of  the  salt  into  a  litre  of 
water),  sharpened  with  6  grammes  of  nitro-muriatic  acid 


Very  fine  yellow  tones  have  been  obtained  by  putting  a  proof  pretty  strong  at  first 
into  the  hyposulphite,  then  into  a  bath  composed  of  a  litre  of  water,  and  50  grammes  of 
hydrochloric  acid ;  finally  rinsing  it  with  water.  Water  of  ammonia  used  in  the  same 
dose,  without  putting  the  proof  previously  in  the  hyposulphite  of  soda,  gives  also 
remarkable  tones.  When  the  proof  is  of  the  desired  tone,  wash  it  with  several  waters, 
and  leave  it  two  or  three  hours  in  a  basin,  taking  it  out  only  when  the  proof  has  no 
longer  a  sweet  taste  on  the  tongue,  characteristic  of  the  hyposulphite  of  silver.  It  is  to 
be  then  dried  by  hanging  by  a  corner  ;  when  it  is  finished.  The  hyposulphite  bath  may 
contain  as  many  proofs  as  we  please  at  a  time.  But  great  care  must  be  taken  to  entangle 
no  air  bubbles  among  the  leaves,  which  would  produce  indelible  black  spots.  A  long- 
haired pencil  is  useful  for  clearing  away  these  bubbles.  The  taking  of  the  positive  proofs 
requires  all  the  attention  of  a  skilful  operator,  and  it  must  not  be  disregarded.  It  is 
necessary  to  calculate  rightly  the  shade  of  a  proof  with  the  subject,  and  the  effect  wished 
to  be  produced.    A  superior  fine  proof  should  be  put  by  itself  in  the  hyposulphite  of  soda. 

Heliographs  or  Photographs  have  been  recently  taken  of  extreme  accuracy  and  fine- 
ness of  delineation,  upon  glass  coated  with  albumen,  by  the  following  recipe  : — Put  the 
whites  of  ten  eggs  into  a  large  basin  ;  dissolve  in  them,  by  beating  them  with  a  box-wood 
fork,  4  grammes  of  iodide  of  potassium ;  ^  gramme  of  bromide  of  ammonia,  and  as  much 
chloride  of  sodium.  Reduce  it  to  a  white  thick  froth,  leave  it  to  settle  for  a  night,  and 
next  morning  decant  the  viscid  liquor  which  has  fallen,  and  keep  it  for  use.  This  glairy 
compound  is  best  when  applied  to  depolished  glass.  A  film  of  collodium  on  glass  is  now 
preferred.  For  the  remaining  minute  precautions  and  directions,  I  refer  to  the  publication 
of  M.  Le  Grey,  entitled  Nouveau  Traite  Theorique  et  Pratique  de  Photographie. 

HELIOTROPE;  is  a  variety  of  Jasper,  mixed  with  chlorite,  green  earth,  and  diallage; 
occasionally  marked  with  blood-red  points;  whence  its  vulgar  name  oi  blood  stone. 

HEMATINE;  is  the  name*  given  by  its  discoverer  Chevreul  to  a  crystalline  substance, 
of  a  pale  pink  colour,  and  brilliant  lustre  when  viewed  in  a  lens,  which  he  extracted 
from  logwood,  the  hcematoxylon  Campechianum  of  'botanists.  It  is,  in  fact,  the  charac- 
teristic principle  of  this  dye-wood.  To  procure  hematine,  digest  during  a  few  hours 
ground  logwood  in  water  heated  to  a  temperature  of  about  130**  Fahr. ;  filter  the  liquor, 
evaporate  it  to  dryness  by  a  steam  bath,  and  put  the  extract  in  alcohol  of  0835  for  a  da}'. 
Then  filter  anew,  and  after  having  inspissated  the  alcoholic  solution  by  evaporation, 
pour  into  it  a  little  water,  evaporate  gently  again,  and  then  leave  it  to  itself  in  a  cool 
place.  In  this  way  a  considerable  quantity  of  crystals  of  hematine  will  be  obtained, 
which  may  be  readily  purified  by  washing  with  alcohol  and  drying. 

When  subjected  to  dry  distillation  in  a  retort,  hematine  affords  all  the  usual  products 
of  vegetable  bodies,  along  with  a  little  ammonia ;  which  proves  the  presence  of  azote. 
Boiling  water  dissolves  it  abundantly,  and  assumes  an  orange-red  colour,  which  passes 
into  yellow  by  cooling,  but  becomes  red  again  with  heat.  Sulphurous  acid  destroys  the 
colour  of  solution  of  hematine.  Potash  and  ammonia  convert  into  a  dark  purple-red 
tint,  the  pale  solution  of  hematine ;  when  these  alkalis  are  added  in  large  quantity,  they 
make  the  colour,  violet  blue,  then  brown-red,  and  lastly  brown-yellow.  By  this  time  the 
hematine  has  become  decomposed,  and  cannot  be  restored  to  its  pristine  state  by  neutraliz- 
ing the  alkalis  with  acids. 

The  waters  of  baryta,  strontia,  and  lime  exercise  an  analogous  power  of  decomposition ; 
but  they  eventually  precipitate  the  changed  colouring  matter. 

A  red  solution  of  hematine  subjected  to  a  current  of  sulphuretted  hydrogen  becomes 
yellow ;  but  it  resumes  its  original  hue  when  the  sulphuretted  hydrogen  is  removed  bv  a 
little  potash. 

The  protoxide  of  lead,  the  protoxide  of  tin,  the  hydrate  of  peroxide  of  iron,  the  hydrat« 
of  oxides  of  copper  and  nickel,  oxide  of  bismuth,  combine  with  hematine,  and  coUmr  it 
blue  with  more  or  less  of  a  violet  cast 

Hematine  precipitates  glue  from  its  solution  in  reddish  flocks.  This  substance  1ms  not 
hitherto  been  employed  in  its  pure  state ;  but  as  it  constitutes  the  active  principle  of 
logwood,  it  enters  as  an  ingredient  into  all  the  colours  made  with  that  dye  stuff. 

niese  colours  are  principally  violet  and  black.  Chevreul  has  proposeS  hematine  as  an 
excellent  test  of  acidity. 

HEMATITE ;  {Per  Oligiste,  Fr. ;  Rotheisenstein,  Germ.)  is  a  native  reddish  brown 
peroxide  of  iron,  consisting  of  oxygen  30  66 ;  iron  60-34.  It  is  the  kidney  ore  of  Cumber- 
land which  is  smelted  at  Ulverstone  with  charcoal,  into  excellent  steel  iron. 

HEMP;  (C/mnwre,  Fr. ;  Hanf  Germ.)  is  the  fibrous  rind  of  the  bark  of  the  cannabi* 
sativa,  which  is  spun  into  strands  or  yarn  for  making  rope,  sail-cloth,  <fec.  It  is  prepared 
for  spinning  in  the  same  way  as  flax,  which  see.  Hemp-seed  contains  an  oil  which  is 
employed  for  making  soft  soap,  for  painting,  and  for  burning  in  lamps.     See  Oils. 

The  importation  of  undressed  hemp  for  home  consumption  in  1851  and  1852,  was 
respectively  1,048,635  cwts.  and  1,293,412  cwts. 

HEPAR ;  which  signifies  liver  in  Latin,  was  a  name  given  by  the  older  chemists  to 

64 


1010 


HOMBOURG  MINERAL  WATERS. 


some  of  those  compounds  of  sulphur  with  the  metals  which  had  a  liver-brown  colour 
Thus  the  sulphuret  of  potassium  was  called  liver  of  sulphur. 

HEPATIC  AIR;  sulphuretted  hydrogen  gas. 

HERMETICAL  SEAL,  is  an  expression  derived  from  Hermes,  the  fabulous  parent 
of  Egyptian  chemistry,  to  designate  the  perfect  closure  of  a  hollow  vessel,  by  the 
cementing  or  melting  of  the  lips  of  its  orifice ;  as  in  the  case  of  a  glass  thermometer,  or 
matrass. 

HIDE  ;  {Peau,  Fr.;  Haut,  Germ.)  the  strong  skin  of  an  ox,  horse,  or  other  large  animal. 
See  Leathes. 


Untanned,  dry        -          -       cwts. 
wet       -          -       cwts. 

Tanned,  tawed,  curried  or 
dressed  (except  Russia 
hides)       -           -           -        lbs. 

Imports. 

Exports. 

1851. 

1852. 

1861. 

1852. 

160,575 
441,346 

1,876,557 

187,091 
485,076 

2,275,107 

83,799 
29,779 

105,924 

113,727 
43,200 

79,817 

HOP. 


1011 


HIRCINE ;  from  hirctis,  a  ram ;  is  the  name  given  by  Chevreul  to  a  liquid  fatty  sub- 
stance, which  is  mixed  with  the  oleine  of  mutton  suet,  and  gives  it  its  peculiar  rank 
smell.  Hircine  is  much  more  soluble  in  alcohol  than  oleine.  It  produces  hircic  acid  by 
saponification. 

HOG'S  LARD ;  see  F.\ts. 

HOLLOW  FOUNDING.  Candlesticks  are  cast  in  sand  and  made  hollow,  by  the 
introduction  into  the  mould  of  what  is  called  a  "  core,"  viz.,  a  piece  of  sand  corresponding 
in  size  to  the  hollow  of  the  pillar.  Upon  his  skill  in  makuig  this  in  such  a  manner 
as  to  produce  uniform  thickness  of  metal  throughout,  depends  the  success  of  the  work- 
man ;  the  metal  must  also  be  of  a  proper  temperature,  or  the  casting  is  rendered 
useless  by  the  presence  of  flaws.  Candlesticks  are  finished  by  being  turned  and  polished 
by  friction,  when  in  a  state  of  motion  in  the  lathe ;  the  bottoms,  when  round,  are  also 
turned  ;  when  square,  they  are  filed  and  polished.  The  composition  of  metal  in  this  case 
is  copper  and  zinc,  in  the  proportion  of  10  ounces  of  the  former  to  8  ounces  of  the  latter. 

HOMBOURG ;  MINERAL  WATERS  OF.  The  city  of  Hombourg  near  Frankfort, 
is  situated  at  the  bottom  and  to  the  east  of  the  mountains  of  Taunus,  600  ft.  above  the 
level  of  the  sea,  in  a  picturesque  position. 

The  Elizabeth  spring  consists  by  Liebig's  analysis  in  16  ozs.  of— 


Chlor.  sodium 
Sulphate  of  soda 
Chlor.  calcium 
Chlor.  magnesium 
Silica 

Carbonate  of  lime 
Do.  of  magnesia 
Proto-carbonate  of  iron 
Free  carbonic  acid 


Groins. 

791547 
0-3809 
7-7568 
7-7670 
0-3157 

10-9824 
20111 
0-4608 

21-4808 

130-3102 


THE  BATH  SPRING, 
combined  with — 


Contains  for  16  oz.  of  water,  22-728  cubic  in.  of  carbonic  acid 


Sulphate  of  lime 
Chlor.  calcium 

magnesium 

do. 
potassium 
sodium 


Brom. 

Chlor. 

Chlor. 

Do. 

Silica 

Proto-carbonate  of  iron 

Alumina 

Carbonate  of  lime 

Do.      magnesia 


Grains. 
0-212 

15-285 
0-002 
5-904 
0-384 
108-392 
0164 
0-480 
0054 
9-698 
2-485 

143.060 


To  this  water  are  added  occasionally  some  of  the  salt  springs  of  Bingen,  which  contain 
considerable  quantities  of  the  compounds  of  bromine  and  iodine. 

Mother  Water,  is  the  name  given  to  the  clear  liquor  which  remains  in  the  boiler, 
when,  after  evaporating  the  water,  the  common  salt  has  been  crystallized  and  separated. 
This  residuum  is  greasy  to  the  touch,  but  a  little  thinner  than  oil,  and  when  applied  to 
the  skin  covers  it  with  small  scales,  as  if  it  had  been  washed  with  chlor-calcium.  Iodine 
and  bromine  exist  in  it,  and  are  supposed  to  give  it  efficacy  against  scrofulous  and  chronic 
diseases. 

HONEY  ;  {Mel,  Fr. ;  Honig,  Germ.)  is  a  sweet  viscid  liqvjor,  elaborated  by  bees  from 
the  sweet  juices  of  the  nectaries  of  flowers,  and  deposited  by  them  in  the  waxen  cells  of 
their  combs.  Virgin  honey  is  that  which  spontaneously  flows  with  a  very  gentle  heat 
from  the  comb,  and  common  honey  is  that  which  is  procured  by  the  joint  agency  of 
pressure  and  heat  The  former  is  whitish  or  pale  yellow,  of  a  granular  texture,  a 
fragrant  smell,  and  a  sweet  slightly  pungent  taste ;  the  latter  is  d%rker  coloured,  thicker, 
and  not  so  agreeable  either  in  taste  or  smelL  Honey  would  seem  to  be  simply  col- 
lected by  the  bees,  for  it  consists  of  merely  the  vegetable  products ;  such  as  the  sugars 
of  grape,  gum,  and  manna ;  along  with  mucilage,  extractive  matter,  a  little  wax  and 
acid. 

HONEY-STONE ;  (Mellite,  Fr. ;  Honigstein,  Germ.)  is  a  mineral  of  a  yellowish  or  red- 
dish colour,  and  a  resinous  aspect,  crystallizing  in  octahedrons  with  a  square  base  ;  specific 
gravity  1-58.  It  is  harder  than  gypsum,  but  not  so  hard  as  calc-spar;  it  is  aeeply 
scratched  by  a  steel  point ;  very  brittle  ;  affords  water  by  calcination  ;  blackens,  then  burns 
at  the  flame  of  the  blowpipe,  and  leaves  a  white  residuum  which  becomes  blue,  when  it 
is  calcined  after  having  been  moistened  with  a  drop  of  nitrate  of  cobalt.  It  is  a  mellate 
of  alumina,  and  consists  of: 


Mellitic  acid 
Alumina  - 
Water      - 


Klaproth. 


46 
16 

81 


100 


Wohler. 


44-4 
14-5 
411 


100-0 


The  honey-stone,  like  amber,  belongs  to  the  geological  formation  of  lignite.  It  has 
been  hitherto  found  clearly  in  only  one  locality,  at  Artern  in  Thuringia. 

HOP ;  {Houhlon,  Fr. ;  Hopfen,  Germ.)  is  the  name  of  a  well-known  plant  of  the  natural 
family  of  Urticeae,  and  of  the  dicecia  pentandria  of  Linnaeus.  The  female  flowers,  placed 
upon  different  plants  from  the  male,  grow  in  ovoid  cones  formed  of  oval  leafy  scales,  con- 
cave, imbricated,  containing  each  at  the  base  an  ovary  furnished  with  two  tubular  open 
styles,  and  sharp  pointed  stigmata.  The  fruit  of  the  hop  is  a  small  rounded  seed,  slightly 
compres.sed,  brownish  coloured,  enveloped  in  a  scaly  calyx,  thin  but  solid,  which  contains, 
spread  at  its  base,  a  granular  yellow  substance,  appearing  to  the  eye  like  a  fine  dust,  but 
in  the  microscope  they  seem  to  be  round,  yellow,  transparent,  grains ;  deeper  coloured, 
the  older  the  fruit.  This  secretion,  which  constitutes  the  useful  portion  of  the  hop,  has 
been  examined  in  succession  by  Ives,  Planche,  Payen,  and  Chevallier.  I  have  given  a 
pretty  full  account  of  the  results  of  their  researches  in  treating  of  the  hop  under  the 
article  Beer. 

Annual  Amount  of  Hop  Duty,  Average  Price  per  Cwt.,  and  Number  of  Acres. 


Tear. 

Duty. 

Average  Price. 

No.  of  Acres. 

£ 

£     s.     d. 

1838 

•      171,556 

5     17     0 

55,045 

1839 

205,637 

4     10     0 

52,805 

1840 

34,091 

13     11     0 

44,805 

1841 

146,159 

6       6     0 

45,769 

1842 

169,773 

4     18     0 

43,720 

1843 

133,508 

8       0     0 

43,156 

1844 

140,322 

7     16     0 

44,485 

1845 

158,003 

— • i 

7     10    0 

48,058 

1012 


HORN. 


HORN. 


1013 


Pounds  Weight  of  Hopa  which  paid  Duty  from  1840  to  1845. 


1840 
1841 
1842 
1843 
1844 
1846 


Lbs. 
7,114,911 
80,604,106 
86,432,142 
27,862,725 
29,285,092 
32,974,749 


Number  of  Acres  under  the  Cultivation  of  Hops  in  England. 


1807 
1808 
1809 
1  1810 
,  1811 
!  1812 


38,218 
38,436 
38,357 
38,205 
38,401 
38.700 


1813 
1814 
1815 
1816 
1817 
1818 


39,521 
40,571 
42,150 
44,219 
46,493 
48,593 


1819 
1820 
1821 
1822 
1623 
1824 


51,014 

1825 

46,718 

50,148 

1826 

50,471 

45,662 

1827 

49,465 

43,766 

1828 

48,365 

41,458 

1829 

46,135 

43,449 

1830 

46,726 

1831 
1832 
1833 
1834 
1835 
1836 


47,129 
47,101 
49,187 
51,273 
53,816 
55,422 


1837 
1838 
1839 
1840 
1841 
1842 


56.323 
55,046 
52,305 
44,805 
45,769 


Annual  amount  of  hop  duty. 


Yrs. 


1711 

1712 

1713 

1714 

1715 

1716 

1717 

1718 

1719 

1720 

1721 

1722 

1723 

1724 

1725 

1726 

1727 

1728 

1729 

1730 

1711 

1732 


Amount. 


£43,437 
30,278 
23,018 
14,457 
44,975 
20,354 
54,669 
15,005 
90,317 
38,169 
61,362 
49,443 
30,279 
61,271 
6,526 
80,031 
69,409 
41,494 
48,441 
44.419 
22.600 
35,135 


Yrs. 


1733 

1734 

1735 

1736 

1737 

1738 

1739 

1740 

1741 

1742 

1743 

1744 

1745 

1746 

1747 

1748 

1749 

1750 

1751 

1752 

1753 

1754 


Amount. 


£70,215 
37,716 
42,745 
46.482 
56,492 
86,575 
70,742 
37,875 
65,222 
45,550 
61,072 
46,708 
34,635 
91,679 
62,993 
87,155 
36,805 
72,138 
73,954 
82,163 
91,214 
102,012 


Yrs. 


1755 

1756 

1757 

17.58 

1759 

1760 

1761 

1762 

1763 

1764 

1765 

1766 

1767 

1768 

1769 

1770 

1771 

1772 

1773 

1774 

1775 

1776 


Amount. 


£82,157 
48.106 
69.713 
72,896 
42,115 
117,992 
79,776 
79,295 

88,315 

17.178 

73,778 
116,445 

25,997 
114,002 

16,201 
101,131 

33,143 
102,6.')0 

45,847 
138,887 

41,597 
125,691 


Yrs. 


Amount. 


1777 
1778 
1779 
1780 
1781 
1782 
1783 
1784 
1785 
1786 
1787 
1788 
1789 
1790 
1791 
1792 
1793 
1794 
1795 
1796 
1797 
1798 


£43.581 

159,891 

55, 8(H) 

122,724 

120,218 

14,895 

75,716 

94,359 

112,684 

95,973 

42,227 

143,I6« 

104,063 

106,841 

90,059 

162,112 

22,619 

203,063 

82,342 

75,223 

157,458 

56,032 


Yrs. 


1799 
1800 
1801 
1802 
1S03 
I«04 
1605 
lo06 
.507 
1S08 
lh09 
U\0 
1811 
1812 
1813 
1814 
1815 
1816 
1817 
1818 
1819 
1820 


Amount. 


£73,279 

72,928 

241,227 

15,463 

199,305 

177,617 

32,904 

153,102 

100,071 

251,089 

63,452 

73,514 

157,025 

30,r>33 

131,482 

140,202 

123,878 

46,302 

66,522 

199,465 

242,476 

138,330 


Yrs. 


1821 

1822 

1823 

1824 

1825 

1826 

1827 

1828 

1829 

1830 

1831 

1832 

18.33 

1834 

1835 

1636 

1837 

1838 

1839 

1840 

1841 

1842 


Amount 


£154,609 
203,724 

26,058 
148,832 

24,317 
269,331 
140.848 
172,027 

38,398 

88,047 
174,864 
139,018 
156,905 
189,713 
235,207 
200,332 
178.578 
171,556 
205,5.37 

34,09) 
146,159 
169,776 


Hop  duties  of  particular  districts. 


Rochester 
Canterbury 

Kent 

Sussex 

Worcester 

Farnharn 

North  Clays 

Essex 

Sundries 


1839. 


£60.H02  16 
50,649    3 


6 
0 


111,451  19 
65,026  19 
16,639  16 
7,730 
2,005 
1.624 
1,058 


6 
7 
4 
2 
10 
9 
5 


205,538  12    7 


1840. 


£23,256  19  8 
5,757    0  4 


29,014    0  0 
3,080  12  9 

239     " 

1,643  18 

57    4 

35  17  1 

20    4  8 


19  0 

p. 
t 

1 


34,091  17  2 


1841. 

£51,490 

3 

8 

33,960 

14 

10 

85,450 

18 

6 

38,086  13  10  ! 

12,076 

19 

8 

7,702 

10 

2 

1,159 

7 

10 

977 

3 

0 

705 

8 

< 

1842. 


£58,812    4    7 
31,019  13    5 


90,731 
43,561 
19,815 


18 

10 

2 


0 

0 

11 


11, ^78 

18 

4  ) 

1,724 

2 

7 

2,050 

19 

11 

203 

14 

». 

146,159     1 


169,776    6    0  j 


HORDEINE  is  the  name  given  b>  Proust  to  the  peculiar  starchy  matter  of  barley,  k 
seems  to  bf  a  mixture  of  the  starch,  lignine,  and  husks,  which  constitutes  barley  meal. 

HORNVEne.  and  Germ. ;  Come,  Fr.),  particularly  ol  oxen,  cows,  goats,  and  sheep,  is 
a  s^^iancfsoK  tough,  semi-transp'arent,  and  susceptible  of  ^tL'^'TurtL'S  torts^ 
varitty  of  forms ;  it  is  this  property  that  distinguishes  it  from  bone.    TurUe  or  tortoise 


shell  seems  to  be  of  a  nature  similar  to  horn,  but  instead  of  being  of  a  uniform  color,  it 
is  variegated  with  spots. 

These  valuable  properties  render  horn  susceptible  of  being  employed  in  a  variety 
of  works  fit  for  the  turner,  snuff-box,  and  comb  maker.  The  means  of  softening 
the  horn  need  not  be  described,  as  it  is  well  known  to  be  by  heat ;  but  those  of  cutting, 
polishing,  and  soldering  it,  so  as  to  make  the  plates  of  large  dimensions,  suitable  to 
form  a  variety  of  articles,  may  be  detailed.  The  kind  of  horn  to  be  preferred  is 
that  of  goats  and  sheep,  from  its  being  whiter  and  more  transparent  than  the  horn 
of  any  other  animals.  When  horn  is  wanted  in  sheets  or  plates,  it  must  be  steeped 
in  water,  in  order  to  separate  the  pith  from  the  kernel,  for  about  fifteen  days  in  sum 
mer,  and  a  month  in  winter ;  and  after  it  is  soaked,  it  must  be  taken  out  by  one  end, 
well  shaken  and  rubbed,  in  order  to  get  off  the  pith ;  after  which  it  must  be  put  for 
half  an  hour  into  boiling  water,  then  taken  out,  and  the  surface  sawed  even,  length- 
ways ;  it  must  again  be  put  into  the  boiling  water  to  soften  it,  so  as  to  render  it  caqabie 
of  separating  ;  then,  with  the  help  of  a  small  iron  chisel,  it  can  be  divided  into  sheets  or 
leaves.  The  thick  pieces  will  form  three  leaves,  those  which  are  thin  will  form  only 
two,  whilst  young  horn,  which  is  only  one  quarter  of  an  inch  thick,  will  form  only  one. 
These  plates  or  leaves  must  again  be  put  into  boiling  water,  and  when  they  are  sutficiently 
soft,  they  must  be  scraped  with  a  sharp  cutting  instrument,  to  render  those  parts  that  are 
thick  even  and  uniform;  they  must  be  put  once  more  into  the  boiling  water,  and  finally 
carried  to  the  press. 

At  the  bottom  of  the  press  employed,  there  must  be  a  strong  block,  in  which  i« 
formed  a  cavity,  of  nine  inches  square  and  of  a  proportionate  depth ;  the  sheets  of  horn 
are  to  be  laid  within  this  cavity,  in  the  following  manner  at  the  bottom :  first  a  sheet  of 
hot  iron,  upon  this  a  sheet  of  horn,  next  again  a  sheet  of  hot  iron,  and  so  on,  taking  care 
to  place  at  the  top  a  plate  of  iron  even  with  the  last.  The  press  must  then  be  screwed 
down  tight. 

There  is  a  more  expeditious  process,  at  least  in  part,  for  reducing  the  horn  into 
sheets,  when  it  is  wanted  very  even.  After  having  sawed  it  with  a  very  fine  and  sharp 
saw,  the  pieces  must  be  put  into  a  copper  made  on  purpose,  and  there  boiled,  until  suffi- 
ciently soft,  so  as  to  be  able  to  split  with  pincers ;  the  sheets  of  horn  must  then  be  put  m 
the  press,  where  they  are  to  be  placed  in  a  strong  vice,  the  chaps  of  which  are  of  iron 
and  larger  than  the  sheets  of  horn,  and  the  vice  must  be  screwed  as  quick  and  tight  as 
possible ;  let  them  cool  in  the  press  or  vice,  or  it  is  as  well  to  plunge  the  whole  into  cold 
water.  The  last  mode  is  preferable,  because  the  horn  does  not  shrink  in  cooling.  Now 
draw  out  the  leaves  of  horn,  and  introduce  other  horn  to  undergo  the  same  process. 
The  horn  so  enlarged  in  pressing,  is  to  be  submitted  to  the  action  of  the  saw,  which 
ought  to  be  set  in  an  iron  frame,  if  the  horn  is  wanted  to  be  cut  with  advantage,  in 
sheets  of  any  desired  thickness,  which  cannot  be  done  without  adopting  this  mode.  The 
thin  sheets  thus  produced  must  be  kept  constantly  very  warm  between  plates  of  hot 
iron  to  preserve  their  softness;  every  leaf  being  loaded  with  a  weight  heavy  enough  to 
prevent  its  warping.  To  join  the  edges  of  these  pieces  of  horn  together,  it  is  necessary 
to  provide  strong  iron  moulds  suited  to  the  shape  of  the  article  wanted,  and  to  place  the 
pieces  in  contact  with  copper-plates  or  with  polished  metal  surfaces  against  them  ;  when 
this  is  done,  the  whole  is  to  be  put  into  a  vice  and  screwed  up  tight,  then  plunged  into 
boiling  water,  and  after  some  time  it  is  to  be  removed  from  thence  and  immersed  in  cold 
water.  The  edges  of  the  horn  will  be  thus  made  to  cement  together  and  become  perfect- 
ly united. 

To  complete  the  polish  of  the  horn,  the  surface  must  be  rubbed  with  the  subnitrate  of 
bismuth  by  the  palm  of  the  hand.  The  process  is  short,  and  has  this  advantage,  that  it 
makes  the  horn  dry  promptly. 

When  it  is  wished  to  spot  the  horn  in  imitation  of  tortoise-shell,  metallic  solutions 
must  be  employed  as  follows  : — To  spot  it  red,  a  solution  of  gold,  in  aqua  re?ia,  must  be 
em|»loyed ;  to  spot  it  black,  a  solution  of  silver  in  nitric  acid  must  be  used ;  and  for 
brown,  a  hot  solution  of  mercury  in  nitric  acid.  The  right  side  of  the  horn  must  be 
impregnated  with  these  solutions,  and  they  will  assume  the  colors  intended.  The 
brown  spots  can  be  produced  on  the  horn  by  means  of  a  paste  made  of  red  lead,  with  a 
solution  of  potash,  which  must  be  put  in  patches  on  the  horn,  and  subjected  some  lime  to 
the  action  of  heat.  The  deepness  of  the  brown  shades  depends  upon  the  quantity  of 
potash  used  in  the  paste,  and  the  length  of  time  the  mixture  lies  on  the  horn.  A  de- 
coction of  Brazil  wood,  or  a  solution  of  indigo,  in  sulphuric  acid,  or  a  deoclion  of  saflTron. 
and  Barbary  wood  may  also  be  used.  After  having  employed  these  materials,  the  born 
may  be  left  for  half  a  day  in  a  strong  solution  of  vinegar  and  alum. 

In  France,  Holland,  and  Austria,  the  comb-maker  and  horn -turners  use  the  clippings 
of  horn,  which  are  of  a  whiti.«h  yellow,  and  tortoise-shell  skins,  out  of  which  they  make 
snuff-boxes,  powder-horns,  and  many  curious  and  handsome  things.  They  first  soften 
the  horn  and  shell  in  boiling  water,  so  as  to  be  able  to  submit  them  to  the  press  in  iron 


1   14 


HORNSTONE. 


moulds,  and  by  means  of  heat  form  them  into  one  mass.  Tlie  degree  of  heat  necessary 
to  join' the  horn  clippings  must  be  stronger  than  tliat  for  shell  skins,  and  it  can  only  be 
found  out  by  experience.  The  heat  must  not  however  be  too  great,  for  fear  of  scorching 
the  horn  or  shell  Considerable  care  is  required  in  these  operations,  not  to  touch  the 
horn  with  the  fingers,  or  with  any  greasy  body,  because  the  grease  will  prevent  the 
perfect  joining.  Wooden  instruments  should  be  used  to  move  them,  while  they  are  at 
the  fire,  and  for  carrying  them  to  the  moulds. 

In  making  a  ring  of  horn  for  bell-pulls,  <fec.,  the  required  piece  is  to  be  first  cut  out 
in  the  flat  of  its  proper  dimensions,  and  nearly  in  the  shape  of  a  horse-shoe  ;  it  is  then 
pressed  in  a  pair  of  dies  to  give  its  surface  the  desired  pattern  ;  but  previous  to  the  pressure, 
both  the  piece  of  horn  and  the  dies  are  to  be  lieated :  the  piece  of  horn  is  to  be  intro- 
duced between  the  dies,  squeezed  in  a  vice,  and  when  cold,  the  impression  or  pattern 
will  be  fixed  upon  the  horn.  One  particular  condition,  however,  is  to  be  observed  in 
the  construction  of  the  dies,  for  forming  a  ring.  They  are  to  be  so  made,  that  the  open 
ends  of  the  horse-shoe  piece  of  horn,  after  being  pressed,  shall  have  at  one  end  a  nib, 
and  at  the  other  a  recess  of  a  dovetailed  form,  corresponding  to  each  other  ;  and  the 
second  operation  in  forming  this  ring  of  horn  is  to  heat  it,  and  pl.ice  it  in  another  pair 
of  dies,  which  shall  bring  its  open  ends  together,  and  cause  the  dovetailed  joints  to  be 
locked  fast  into  each  other,  which  completes  the  ring,  and  leaves  no  appearance  of  the 

junction. 

In  forming  the  handles  of  table  knives  and  forks,  or  other  things  which  require  to  be 
made  of  two  pieces,  each  of  the  two  pieces  or  sides  of  the  handle  is  formed  in  a  separate 
pair  of  dies ;  the  one  piece  is  made  with  a  counter-sunk  groove  along  each  side,  and  the 
other  piece  with  corresponding  leaves  or  projecting  edges.  When  these  two  pieces  are 
formed,  by  the  first  being  cut  out  of  the  flat  horn,  then  pressed  in  the  dies  in  a  heated  state, 
for  the  purpose  of  giving  the  pattern,  the  two  pieces  are  again  heated  and  put  together, 
the  leaves  or  edges  of  the  one  piece  dropping  into  the  counter-sunk  grooves  of  the  other 
piece,  and  being  introduced  between  another  pair  of  heated  dies,  the  joints  are  pressed 
together  and  the  two  pieces  formed  into  one  handle. 

In  making  the  knobs  for  drawers  which  have  metal  stems  or  pins  to  fasten  them  into 
the  furniture,  the  face  of  the  knob  is  to  be  first  made  in  a  die,  as  above  described,  and  then 
the  back  part  of  the  knob  with  a  hole  in  it ;  a  metal  disc  of  plate-iron  is  next  provided 
in  which  the  metal  stem  or  screw  pin  is  fixed,  and  the  stem  being  passed  through 
the  aperture  in  the  back  piece,  and  the  two,  that  is,  the  back  and  the  front  pieces  of  horn 
put  together,  they  are  then  heated  and  pressed  in  dies  as  above  described ;  the  edge  of 
the  back  piece  falling  into  the  counter-sunk  groove  of  the  front  piece,  while  by  the  heat 
they  are  perfectly  cemented  together.  ,-1.1. 

Mr.  J.  James  has  contrived  a  method  of  opening  up  the  horns  of  cattle,  by  which  he 
avoids  the  risk  of  scorching  or  frizzling,  which  is  apt  to  happen  in  heating  them  over  an 
open  fire.  He  takes  a  solid  block  of  iron  pierced  with  a  conical  hole,  which  is  fitted 
with  a  conical  iron  plug,  heats  them  in  a  stove  to  the  temperature  of  melting  lead,  and 
having  previously  cut  up  the  horn  lengthwise  on  one  side  with  a  saw,  he  inserts  its 
narrow  end  into  the  hole,  and  drives  the  plug  into  it  with  a  mallet.  By  the  heat  of  the 
irons,  the  horn  gets  so  softened  in  the  course  of  about  a  minute,  as  to  bear  flatting  out  in 

the  usual  way. 

HORNSILVER ;  (Argent  Come,  or  Kerargyre,  Fr. ;  Hornsilber,  Germ.)  is  a  wlute 
or  brownish  mineral,  sectile  hke  wax  or  horn ;  and  crystallizing  in  the  cubic  system. 
Its  specific  gravity  varies  from  4-76  to  555.  Insoluble  in  water ;  not  volatile  ;  fusible 
at  the  blowpipe,  but  difficult  of  reduction  by  it.  It  deposits  metallic  silver  when 
rubbed  with  water  upon  a  piece  of  clean  copper  or  iron.      It  consists  of  24*67  chlorine, 

and  75-32  silver.  .  •      .    xi.    j-  ^  •  1 

Hornsilver  is  rare  in  the  European  mines,  but  it  occurs  in  great  quantity  in  the  districts 
of  Zacatecas,  Fresnillo,  and  Catarce,  in  Mexico:  and  in  Huantajaj^a,  Yauricocha,  <tc.,  in 
Peru  ;  where  it  is  abundantly  mixed  with  the  ores  of  hydrate  of  iron,  called  Pacos  and 
Colorados,  interspersed  with  veins  of  metallic  silver,  which  form  considerable  deposits  in 
the  penasan  limestones.    There  it  is  profitably  mined  as  an  ore  of  silver. 

HORNSTONE ;  is  a  variety  of  rhomboidal  quartz.  Being  both  hard  and  tough,  it 
is  well  adapted  to  form  the  stones  of  pottery  mills  for  grinding  flints ;  it  is  called  cliert 
in  Derbyshire,  where  it  abounds.  1    -j  1  . 

Hornstone  occurs  under  three  modifications:  splintery  hornstone,  conchoidal  horn- 
stone,  and  woodstone.  The  colours  of  the  first  two  are  gray,  white  and  red  ;  they  are 
all  massive ;  dull,  or  of  a  glimmering  lustre.  Translucent  only  on  the  thin  edges.  Difficult 
to  break.  Hornstone  is  less  brittle  than  flint ;  and  by  its  infusibility  before  the  blowpipe 
it  may  be  distinguished  from  petrosilex,  which  it  resembles  in  external  appearance.  The  geo- 
logical locality  of  hornstone  is  remarkable ;  for  it  occurs  in  both  ancient  and  modern  form- 
ations. It  is  found  frequently  in  tlie  veins  that  traverse  primitive  crystalline  rocks, 
filling  up  the  interstices,  and  enveloping  their  metallic  ores.      In  the  lead  mine  of  HueU 


HORSE  POWER. 


1015 


goet  in  Brittany  it  is  whitish  ;  but  its  prevailing  colour  is  gray.  It  occurs  likewise  in  the 
middle  beds  of  the  coarse  limestone  {calcaire  grossier)  in  the  Paris  basin,  which  is  a  com- 
paratively modern  formation,  as  well  as  in  the  sand  beds  of  the  upper  parts  of  this  district, 
near  Saint  Cloud,  Neuilly  <fec.  The  hornstone  which  occurs  in  secondary  limestone  is 
called  cfiert  by  the  English  miners.  It  is  valuable  for  forming  the  grinding  blocks  of 
flint  mills  in  the  pottery  manufacture. 

HORSE  POWER,  in  steam  engines,  is  estimated  by  Mr.  Watt  at  32,000  pounds 
avoirdupois  lifted  one  foot  high  per  minute,  for  one  horse.  Mr.  D'Aubuisson,  from  an 
examination  of  the  work  done  by  horses  in  the  whims,  or  gigs  {machives  d  molottes)  for 
raising  ore  from  the  mines  at  Freyberg,  the  horses  being  of  average  size  and  strength, 
has  concluded  that  the  useful  effect  of  a  horse  yoked  during  eight  hours,  by  two  relays 
of  four  hours  each,  in  a  manege  or  mill  course,  may  be  estimated  at  40  kilogrammes 
raised  1  m6tre  per  second ;  which  is  nearly  16,440  pounds  raised  one  foot  per  minute: 
being  very  nearly  one-half  of  Mr.   Watt's  liberal  estimates  for  the  work  of  his  steam 


engines 


Results  of  the  Application  of  Horse  Power  to  raising  Water  from  the  tvorking  Shafts 
at  Stattwood  Tymnet,  on  the  South  Eastern  Railway,  in  1842.  By  Frederick  William 
Simms,  M  Inst.  C.  E. — This  tunnel  is  driven  in  the  middle  bed  of  the  lower  green  swid, 
between  which  and  the  surface  of  the  ground  is  interposed  only  the  upper  bed  of  the 
same  stratum ;  but  in  sinking  the  eleven  shafts  for  the  work,  it  was  found  that  the  level  of 
the  top  of  the  tunnel,  the  ground  assumed  the  character  of  a  quicksand,  saturated  with 
water,  in  such  quantity  that  it  could  not  be  reduced  by  manual  labour.  Under  these 
circumstances  horse  gins  were  erected  for  drawing  the  water  by  barrels,  containing  one 
hundred  gallons  each,  weighing  when  full  about  1310  lbs. 

The  engineer's  intention  was,  to  dive  simultaneously  from  these  shafts,  in  the  direction 
of  the  tunnel,  an  adit  or  heading  to  carry  off  the  water ;  but  the  earth,  which  was  sand 
mixed  with  fine  particles  of  blue  clay,  was  so  filled  with  water  as  to  become  a  mass  of 
semifluid  mud,  great  exertions  were  therefore  necessary  to  overcome  the  water,  without 
erecting  pumps.  At  first  this  was  accomplished  by  making  each  horse  work  for  12 
hours  and  then  for  8  hours  per  day,  allowing  one  hour  for  food  and  rest :  as  the  water 
increased  it  became  necessary  to  work  night  and  day,  and  the  time  of  each  horse's  work- 
ing was  reduced  generally  to  6  hours,  and  sometimes  to  3  hours.  As  all  the  horses  were 
hired  at  the  rate  of  seven  shillings  per  day,  the  author,  who  had  the  direction  of  the 
works,  ordered  a  daily  register  to  be  kept  of  the  actual  work  done  by  each  horse,  for 
the  double  purpose  of  ascertaining  whether  they  all  performed  their  duty,  and  also 
hoping  to  collect  a  body  of  facts  relative  to  horse  power,  which  might  be  useful  hereafter. 
Tills  detailed  register,  which  was  kept  by  Mr.  P.  N.  Brockedon,  is  appended  to  the 
communication. 

The  author  gives  as  a  proposition,  "  that  the  proper  estimate  of  horse  power  would  be 
that  which  measures  the  weight  that  a  horse  would  draw  up  out  of  a  well ;  the  animal 
actinw  by  a  horizontal  line  of  traction  turned  into  the  vertical  direction  by  a  simple  pulley, 
whose  friction  should  be  reduced  as  much  as  possible."  He  states  that  the  manner  m 
which  the  work  was  performed,  necessarily  approached  very  nearly  to  these  conditions ; 
and  after  giving  the  principal  dimensions  of  the  horse  gins,  he  analyzes  each  set  of  experi- 
ments, and  by  taking  the  mean  of  those,  against  which  no  objections  could  be  urged,  he 
arrives  at  the  following  results : — 

The  power  of  a  horse  for  8  hours  =  23,412  lbs.  raised  1  foot  high  in  one  minute. 
da  do.  6  =  24,360  do. 

do.  do.  4i  =27,056  do. 

do.  do.  3  =.32,943  do. 

Of  these  results,  he  thinks  the  experiments  for  6  hours  and  for  3  hours  alone  should  be 
adopted  as  practical  guides,  all  the  others  being  in  some  degree  objectionable. 

As  a  means  of  comparison,  the  following  table  of  estimates  of  horse  power  is  given : 


Name. 


Boulton  and  Watt  -    -    - 

Tredgold 

Desaguliers 

Ditto 

Saussure 

More,  for  Society  of  Arts 
Smeaton 


Pounds  raised 
1  Foot  high 
in  a  Minute. 


33,000 
27,500 
44,000 
27,500 
34,020 
21,120 
22,000 


Hours  of 
Work. 


8 

8 

8 
Not  stated 

8 
Not  stated 
Not  stated 


Authority. 


Robinson's  Mech.  Phil.,  ii.  145. 
Tredgold  on  Railroads,  p.  69. 


Dr.  Gregory's  Mathematics 
for  Practical  Men,  p.  183. 


1016 


HORSE  POWER. 


These  are  much  higher  results  than  the  average  of  his  experiments,  and  would  more 
nearly  accord  with  the  extremes  obtained  by  him ;  but  under  such  excessive  fatigue,  the 
horses  were  speedily  exhausted,  and  died  rapidly.  Nearly  one  hundred  horses  were 
employed ;  they  were  of  good  quality ;  their  average  height  was  15  hands  ^  inch,  and 
their  weight  about  10^  cwts^  and  they  cost  from  20/.  to  40/.  each.  They  had  as  much 
corn  as  they  could  eat,  and  were  well  attended  to. 

The  total  quantity  of  work  done  by  the  horses,  and  its  cost,  was  as  under: —  ' 


Registered  quantity  of  water  drawn  104  feet,  the  average  height, 
28,220,800  gallons         -  -  .  .  .  . 

do.    earth,    3,500  yds.  1  ton  6  cwt.  per  yard 

Total  weight  drawn  to  the  surface 


tons. 


I    128.635 
4,650 

133,955 


* 
Total  cost  of  horse  labour,  including  a  boy  to  drive  each  horse    -    1,685 

Or  2  8&d.  per  ton  the  average  height  of  104  ft. 


15 


3 


As  soon  as  the  adit  was  driven,  all  the  water  was  carried  off  by  it,  and  the  works  are 
stated  to  be  perfectly  dry. 

Mr.  Palmer  said,  it  should  be  understood,  that  in  stating  32,000  lbs.  raised  one  foot 
high  in  a  minute,  as  tlie  measure  of  the  power  of  a  horse,  Boulton  and  Watt  had  not 
intended  to  fix  that  as  the  average  work  which  horses  were  capable  of  performing :  they 
had  taken  the  highest  results  of  duty  performed  by  powerful  horses,  in  order  to  convince 
the  purchasers  of  their  steam-engines  that  they  received  all  that  had  been  contracted 
for. 

He  had  made  some  experiments  on  the  amount  of  work  performed  by  horses  tracking 
boats  on  canals ;  on  the  upper  end  of  the  mast  of  the  boat  a  pulley  was  hung ;  over  this 
the  towing  rope  was  passed,  with  the  means  of  suspending  to  its  extremity  given 
■weights,  so  as  exactly  to  balance  the  power  exerted  by  the  horse. 

The  results  arrived  at  by  these  means  were  so  various,  that  he  could  not  deduce  any 
average  conclusions ;  as  the  power  exerted  varied  between  30  lbs.  and  120  lbs.,  the  power 
diminishing  as  the  speed  was  increased  ;  he  thought  that  2^  miles  was  too  high  an  average 
estimate,  and  that  it  should  not  exceed  2  miles  per  hour. 

Mr.  Field  remarked  that  in  all  estimates  of  horse  power,  the  speed  was  considered 
to  be  at  an  average  of  2}  miles  per  hour,  and  all  experiments  were  reduced  to  that 
standard. 

Mr.  Hawkins  said,  that  some  years  since,  he  had  made  numerous  inquiries  respecting 
the  work  done  by  horses  in  drawing  upon  common  turnpike  roads,  and  found  that  four 
good  horses  could  draw  an  ordinary  stage  coach,  with  its  complement  of  passengers,  8 
miles  a  day,  at  the  rate  of  10  miles  an  hour ;  that  if  they  ran  stages  10  miles  in  tlie  hour, 
the  horses  must  rest  one  day  in  each  week ;  that  good  horses,  so  worked,  would  last  only 
five  years,  each  horse  drawing  about  half  a  ton :  he  had  been  informed  by  waggoners, 
that  good  horses  would  walk  at  the  rate  of  2^  miles  per  hour,  for  twelve  hours  out  of 
twenty-four,  making  30  miles  a  day ;  and  that  they  would  continue  to  do  such  work  day 
by  day,  each  horse  drawing  one  ton,  for  many  years,  provided  they  had  not  been  worked 
hard  when  young. 

Mr.  Gravatt  observed,  that  although  there  might  exist  some  hesitation  in  receivin<» 
these  results  of  work  actually  performed,  as  a  general  measure  of  a  horse's  power,  yet  as 
engineers  frequently  required  to  know  what  could  be  performed  by  horses,  when  employed 
for  short  periods,  in  works  of  haste  or  difiiculty,  he  thought  that  the  experiments  were 
useful,  and  would  form  good  data  for  reference :  he  was  sorry  to  observe  that  in  too 
many  cases,  an  idea  was  prevalent,  that  it  was  cheaper  to  work  a  small  number  of  horses 
to  death,  than  to  keep  a  large  number,  and  to  work  them  fairly ;  the  results  which  he 
had  been  enabled  to  arrive  at,  were  perhaps  not  a  fair  value  of  a  horse's  work,  continued 
for  any  length  of  time,  at  the  best  rate  of  economy,  for  both  the  contractor  and  the 
employer. 

The  President  believed  that  however,  in  cases  of  emergency,  which  he  allowed  did 
occur  in  engineering  works,  the  forced  system  of  labour  mentioned  by  Mr.  Gravatt  might 
be  tolerated,  he  was  convinced  that  it  was  not  the  most  economical,  but,  on  the  contrary, 
humanity  and  economy  would  be  found  to  go  hand  in  hand. 

It  would  be  desirable  to  know  the  average  speed  at  which  the  diflTerent  rates  of  work 
had  been  performed ;  this  was  essential  in  order  to  found  any  calculation  upon  tl)e  results 
given.  Coach  proprietors  calculated  that  at  a  speed  of  10  miles  per  hour,  a  horse  was 
required  for  every  mile  going  and  returning,  so  that  one  horse  was  kept  for  every  mile 
of  road.     Now  supposing  a  four-horse  coach,  with  an  average  load  to  weigh  2  tons, 


HORSE  POWER. 


1017 


the  load  for  each  horse  was  10  cwts. ;  whereas  in  the  case  of  a  horse  drawing  a  cart,  the 
gross  load  frequently  amounted  to  2  tons,  but  the  speed  was  reduced  to  2^  miles  per 
hour,  at  which  pace  he  conceived  that  16  miles  per  day  might  be  considered  a  fair  day's 
work ;  this  therefore  was  double  the  distance  with  four  times  the  load,  or  eight  times 
the  coach  work,  but  with  a  heavier  horse. 

The  law  that  the  quantity  of  work  done  was  as  the  sauare  root  of  the  velocity,  or 
as  the  cube  root  of  the  velocity,  in  equal  times,  was  confined  to  work  upon  canals,  or 
bodies  moving  through  the  water. 

Mr.  Rennie  had  tried  some  experirhents  on  the  force  of  traction  of  the  boats  on  the 
Grand  Junction  Canal  The  towing  rope  was  attached  to  a  dynamometer,  which  had 
previously  been  tested  by  weights. 

The  horse,  although  urged  at  first  starting,  was  afterwards  allowed  to  fall  mto  his 
natural  speed,  which  was  2^  miles  per  hour  on  the  average  of  20  miles.  The  inaximum 
speed  was  4  miles,  and  the  minimum  2  miles,  per  hour.  The  dynamometer  indicated 
an  ave  rage  of  108  lbs.,  which  was  capable  of  overcoming  the  resistance  of  the  loaded 
barge  of  25  tons,  being  in  the  ratio  of  1500.  The  weight  of  the  horse  was  about  11 
cwts. 

He  also  tried  many  experiments  upon  a  fast  boat,  lent  to  him  in  1833  by  the  late 
Colonel  Page.     These  experiments  were  principally  made  in  order  to  ascertain  the  com- 

Sarative  resistance  of  vessels  moving  through  water  at  different  velocities,  and  the  Grand 
unction  Canal  afforded  a  convenient  opportunity  of  undertaking  them. 
The  boat  was  70  feet  in  length,  4  feet  in  breadth,  and  drew  9  inches  of  water. 
The  traction  indicated  by  the  dynamometer  the  following  resistance  : — 

Miles  ■per  hour.  lbs. 
At  2^  the  resistance  was  20 

3  "  27 
3i  "  80 

4  «  60 
4i  "  60 

5  **  70  to  75 


One  horse  was  employed  in  these  experiments. 

Miles  per  hour.  lbs. 

At  6  the  resistance  was  97  to  214 

7  "  250 

8  "  336 

9  69  "  411 

10  "  375 
llj             «               392 

Average  336 

Two  horses  were  employed  in  these  experiments. 

Stakes  were  fixed  near  the  margin  of  the  canal,  so  as  to  ascertain  the  rise  and  fall  of 
the  wave  caused  by  the  boat  in  passing ;  and  it  was  observed  that  when  a  boat  passed 
with  a  velocity  of  from  4  to  6  miles  per  hour,  the  rise  of  the  wave  was  5  inches,  and 
the  fall  5  inches,  making  a  wave  of  10  inches  in  depth;  and  when  the  velocity  was  11^ 
miles,  the  rise  was  reduced  to  2^  inches,  and  the  fall  to  2^  inches. 

Great  diflference  existed  in  the  power  of  horses,  their  weights  and  structure  ;  and  the 
large  dray  horses  used  by  Messrs.  Barclay,  Perkins,  &  Co.  did  a  full  average  duty 
as  assumed  by  Boulton  and  Watt ;  but  considering  the  average  power  of  strong  and 
weak  animals,  he  had  adopted  22,000  lbs.  raised  1  foot  high  as  the  standard ;  much,  how- 
ever, depended  on  the  nature  of  the  work  performed. 

Mr.  Charles  Wood  remarked,  that  although  on  an  emergency  it  might  be  necessary 
to  work  horses  to  the  extent  which  had  been  mentioned,  it  had  always  been  found  more 
economical  to  feed  them  well,  and  not  unduly  to  force  the  speed,  the  weight  drawn,  or 
the  hours  of  labour.  By  the  recorded  experiments  on  ploughing,  which  were  tried  at 
Lord  Ducie's  and  by  Mr.  Pusey,  it  was  shown  that  any  increase  of  speed  diminished  the 
amount  of  work  done,  in  a  greater  ratio  than  it  was  affected  by  an  increase  of  the  load. 
In  drawing  loads  the  weight  of  the  animal  was  a  point  of  consideration  and  importance, 
and  when  extra  exertions  and  muscular  action  were  required,  the  nearer  horses  ap- 
proached to  •'  thorough  bred,"  the  greater  was  the  result. 

Mr.  Davidson  gave  the  following  statement  of  the  work  performed  by  a  London 
brewer's  horse  per  day  ;  the  cost  of  feed  and  of  wear  and  tear  per  horse  per  annum  being 
derived  from  actual  experience  among  a  large  number  of  horses  at  Messrs.  Truman, 
Hanbury,  &  Co.'s  brewery.  The  feed,  Ac.  is  supposed  to  have  cost  the  same  per  quarter 
per  truss,  <fec.  each  year. 


I 


1018 


HORSE  POWER. 


Tears. 

Pounds  Weight 

drawn  6}  Miles 

per  Horse  per 

Day. 

Pounds  "Weight 
drawn  6^  Miles 
per  Horse  return- 
ing per  Day. 

Average  Pounds 

Weight  drawn 

18  Miles  per 

Horse  per  Day. 

Cost  of  Feed 

and  Straw  per 

Horse  per 

Annum. 

Difference  per 

Horse  of  Horses 

bought  and  sold 

per  Annum. 

1835 
1836 
1837 
1838 
1839 
1840 
1841 
1842 

Total 

Average  7 
years 
nearly  - 

Lbs. 

5,148 
6,072 

6,057 
5,287 
5,786 
6,311 
6,263 

Lbs. 

1,716 

1,767 

1,698 
1,740 
1,820 
1,750 
1,740 

Lbs. 

3,342 

3,389 

3,377 
3,613 
3,803 
3,530 
3,501 

£    9.     d. 

48     2     7 
43  16     6 

41  18     0 

42  9  11 

46  11     7 
45     0     1 

47  0     9 

£     a.     d. 

10     0     8 

9  18     0 

9  16     9 

9     7     1 

7  17  11 

10  16  11 

10     8     0 

36,924 

12,171 

24,455 

309  19     6 

68  .3  11 

5,275 

1,738 

8,506 

44    5     7 

9  14  10 

Mr.  Home  stated  that  Messrs.  Tredwell  had  a  contract  on  the  South  Eastern  Rail- 
way, near  where  Mr.  Simms'  experiments  were  made ;  they  had  upwards  of  100  horses, 
whose  average  cost  was  about  30/. ;  they  were  worked  10  hours  per  day,  and  were  well 
fed,  so  that  their  value  was  but  little  reduced,  and  they  were  eventually  sold  for  nearly 
the  same  prices  as  they  originally  cost  These  contractors  had  about  400  horses  on  the 
Southampton  Railway,  which  cost  them  about  25/.  each.  The  same  course  of  not 
over -working,  and  of  feeding  them  well,  was  pursued  from  motives  of  economy,  and  they 
found  it  answer. 

It  was  Mr.  Jackson's  practice  to  keep  so  many  horses  for  his  work  as  not  to  be  under 
the  necessity  of  working  them  more  than  10  hours  per  day ;  he  gave  to  each  a  peck  of 
com  a-day  ;  by  this  means  he  had  been  able  to  keep  up  their  value. 

On  the  Chester  and  Crewe  Railway  he  had  about  300  horses  at  work,  and  towards 
the  end  of  the  contract,  owing  to  circumstances  over  which  he  had  no  control,  he  was 
obliged  to  work  them  14  or  15  hours  per  day;  and  in  the  course  of  four  months  horses 
that  had  been  worth  25/.  were  so  reduced  as  not  to  be  valued  at  above  7/.  He  is  a  great 
advocate  for  steady  work  and  good  keep. 

On  the  Tame  Valley  Canal  there  had  been  sometimes  between  300  and  400  horses, 
but  as  the  work  was  nearly  finished,  many  had  been  sold.  Those  sub-contractors  who 
had  kept  a  sufficient  number  of  horses  for  the  work,  so  as  not  to  have  them  in  harness 
^ore  than  12  hours  per  day,  had  realized  nearly  the  same  prices  they  had  given  for 
fhem  in  the  first  instance. 

The  horses  belonging  to  Mr.  Edwards,  the  sub-contractor  for  the  excavation  of 
Newton  Hill,  and  those  of  Mr.  W.  Tredwell,  sub-contractor  for  the  Friar  Park  Farm 
cuttings,  were  purchased  from  the  same  parties  at  prices  varying  from  20/.  to  35/.  The 
■brmer  had  been  acting  on  the  principle  of  getting  out  of  the  horses  all  he  could,  work- 
ing them  frequently  15  and  16  hours  at  a  time  ;  and  the  consequences  were,  that  all  his 
Btock  was  in  bad  condition,  and  he  would  be  glad  to  get  6/.  or  11.  a-piece  for  them.  On 
the  other  hand,  Mr.  W.  Tredwell,  who  was  an  excellent  horse  master,  and  who  did  not 
work  his  horses  beyond  their  strength,  would  be  able  to  sell  them  for  about  as  much  as 
he  gave  for  them, — indeed  he  had  done  so  already  for  those  that  he  had  parted  with. 

Having  been  a  good  many  years  in  the  service  of  the  late  Mr.  Mcintosh,  Mr,  Home 
could  state  that  it  never  was  his  system  to  over-work  his  horses.  It  did  sometimes  hap- 
pen that  there  was  no  alternative,  but  the  deviation  from  the  regular  rule  in  every  in- 
stance showed  that  his  system  was  founded  on  right  principles.  The  over- worked  horses 
were  most  liable  to  disease,  and  the  time  lost  by  illness  formed  an  important  item ; 
whereas  there  were  plenty  of  instances  in  which  horses  that  had  worked  their  regular 
10  hours  per  day,  and  had  been  properly  fed,  had  worked  for  five  or  six  years  without 
losing  a  smgle  day  by  illness.  On  the  whole  he  felt  convinced,  that  both  on  the  score 
of  humanity  and  economy,  the  horse  was  the  more  valuable  servant  when  treated  with 
kindness. 

Mr.  Beardmore  said  tliat  a  case»had  occurred  in  a  work  near  Plymouth,  which  he  be- 
lieved would  give  the  fair  value  of  the  work  actually  performed  daily  by  a  horse  for  a 
considerable  period. 

A  quarry-wagon,  weighing  2^  tons,  carrying  an  average  load  of  stone  of  5f  tons,  was 
drawn  by  one  horse  along  a  railway  960  feet  in  length,  260  of  it  being  level,  and  the  re- 
maining 700  feet  having  an  inclination  of  1  in  138.     During  48  working  days  the  numbei 


HOSIERY. 


1019 


of  trips  was  1.302,  or  an  average  of  27-1  trips  each  day  ;  the  time  of  performinjr  each 
trip  was  4  minutes,  or  at  a  speed  of  272  miles  per  hour  ;  and  the  total  weight  drawn, 
including  that  of  the  waggons,  was  23,959,600  lbs. 

Repeated  experiments  proved,  that  upon  the  incline  of  1  in  138  the  waggons  in  their 
ordii.arv  working  state  would  just  remain  stationary;  the  friction  was  therefore  assumed 
to  \m  16-2  lbs.  per  ton;  by  calculation  it  was  found  that  the  horse  raise<l  39.320  lbe».  1 
f(K)t  high  per  minute  during  the  8  working  hours  each  day :  the  useful  effect,  or  net 
amount  of  stone  carried,  being  21,738  lbs.  rai.sed  1  foot  high  per  minute.  This  difference 
between  the  work  done  and  the  useful  effect  arose  from  the  necessary  strengtli  and 
Weight  of  the  waggons. 

The  animal  employed  was  a  common  Devonshire  cart-horse,  8  years  old,  15  hands 
high,  and  weighed  lOf  cwts. ;  he  continued  doing  the  same  work  throughout  a  whole 
eummer,  remaining  in  good  condition  ;  but  a  lighter  horse  was  found  unequal  to  it 

HOSIERY  (Bonneterie,  Fr. ;  Slrumpfweherei,  Germ.).  The  stocking  frame,  which  is 
the  great  implement  of  this  business,  though  it  appears  at  first  sight  to  be  a  complicated 
machine,  fconsists  merely  of  a  repetition  of  parts  easily  understood,  with  a  moderate  de- 
gree of  attention,  provided  an  accurate  conception  is  first  formed  of  the  nature  of  the 
hosiery  fabric.  This  texture  is  totally  diflerent  from  the  rectangular  decussation  which 
constitutes  cloth,  as  the  slightest  inspection  of  a  stocking  will  show ;  ->r  lliis,  instead  of 
having  two  distinct  systems  of  thread,  like  the  warp  and  the  weft,  which  are  woven 
together,  by  crossing  each  other  at  right  angles,  the  whole  piece  is  composed  of  a  single 
thread  united  or  looped  together  in  a  peculiar  manner,  which  is  called  slocking-stitch, 
and  sometimes  chain-work. 

This  is  best  explained  by  the  view  in  fig.   760.      A  single  thread  is  formed  into 

a  number  of  loops  or  waves,  by  arranging  it 
_R  over  a  number  of  parallel  needles,  as  shown  at 
"^  R :  these  are  retained  or  kept  in  the  form  of 
loops   or  waves,    by  being    drawn    or    looped 
through  similar  loops  or  waves  formed  by  the 
thread  of  the  preceding  course  of  the  work,  s. 
The  fabric  thus  formed  by  the  union  of  a  num 
ber  of  loops  is  easily  unravelled,  because  the 
stability  of  the  whole  piece  depends  upon   the 
ultimate  fastening  of  the  first  end  of  the  thread  ; 
and  if  this  is  undone,  the  loops  formed  by  that 
.  end  will  open,  and  release  the  subsequent  loops, 

one  at  a  lime,  until  the  whole  is  unravelled,  and  drawn  out  into  the  single  thread  from 
which  It  was  made.  In  the  same  manner,  if  a  thread  in  a  stocking-piece  fails,  or  breaks 
at  any  part,  or  drops  a  stitch,  as  it  is  called,  it  immediately  produces  a  hole,  and  the  ex- 
tension of  the  rest  can  only  be  prevented  by  fastening  the  end.  It  should  be  observed 
that  there  are  many  diflerent  fabrics  of  stocking-stitch  for  various  kinds  of  ornamental 
hosiery,  and  as  each  requires  a  diflferent  kind  of  frame  or  machine  to  produce  it,  we 
should  greatly  exceed  our  limits  to  enter  into  a  detailed  description  of  them  all.  That 
species  which  we  have  represented  in  ^g.  760  is  the  common  stocking-stitch  used  for 
plain  hosiery,  and  is  formed  by  the  machine  called  the  common  stocking-frame,  which  is 
the  groundwork  of  all  the  others.  The  operation,  as  we  see,  consists  in  drawing  the 
loop  of  a  thread  successively  through  a  series  of  other  loops,  so  long  as  the  woVk  is 
continued,  as  is  very  plainly  shown  for  one  stitch  in  fig.  761. 

There  is  a  great  variety  of  diflerent  frames  in  use  for  producing  various  ornamenUl 
kinds  of  hosiery.  The  first,  which  forms  the  foundation  of  the  whole,  is  that  for  kniltins 
plain  hosiery,  or  the  common  stocking-frame. 

Of  this  valuable  machine,  the  invention  of  Mr.  Lee,  of  Cambridge,  a  side  elevation  is 
given  m  fig.  762,  with  the  essential  parts.  The  framing  is  supjiorted  by  four  upright 
posts,  generally  of  oak,  ash,  or  other  hard  wood.  Two  of  these  posts  appear  at  a  a,  and 
the  connecting  cross  rails  are  at  c  c.  At  b  is  a  small  additional  piece  of  framing,  which 
supports  the  hosier's  seat.  The  iron-work  of  the  machine  is  bolted  or  screwed  to  the 
upper  rails  of  the  frame-work,  and  consists  of  two  parts.  The  first  rests  upon  a  sole  of 
polished  iron,  which  appears  at  d,  and  to  which  a  great  part  of  the  machinery  is 
attached.  The  other  part,  which  is  generally  called  the  carriage,  runs  upon  the  iron 
sole  at  D,  and  is  supported  by  four  small  wheels,  or  trucks,  as  they  are  called  by  the 
workn^en.  At  the  upper  part  of  the  back  standard  of.iron  are  joints,  one  of  which 
appears  at  q;  and  to  these  is  fitted  a  frame,  one  side  of  which  is  seen  exlendir.g  to  h. 
By  means  of  these  jmnts,  the  end  at  h  may  be  depressed  by  the  hosier's  hand,  and  it 
returns,  when  relieved,  by  the  operation  of  a  strong  spring  of  tempered  steel,  acting 
between  a  cross  bar  in  the  frame  and  another  below.  The  action  of  this  spring  is 
very  apparent  in  fig.  763.  In  the  front  of  the  frame,  immediately  opposite  to  where 
the  hosier  sits,  are  placed  the  needles  which  form  the  'cops.     These  needles,  or  ralhei 


!t 


1^ 


I' 


1020 

hooks,  are 
Btocking ; 


HOSIERY. 


more  or    less  numerous, 
and  this, 
'762 


according 


to 


although  unavoidable,  proves 


the  coarseness  or  fineness  of  the 
a  very  considerable  abatement  of 
the  value  of  a  stocking-frame.  In 
almost  every  other  machine  (for 
example,  those  employed  in  spin- 
ning or  weaving),  it  is  easy  to 
adapt  any  one  either  to  work 
coarser  or  finer  work,  as  it  may 
be  wanted.  But  in  the  manu- 
facture of  hosiery,  a  frame  once 
finished,  is  limited  for  ever  in  its 
operation  to  the  same  quality  of 
work,  with  this  exception,  that 
by  changing  the  stuff,  the  work 
may  be  made  a  little  more  dense 
oi  flimsy;  but  no  alteration  in 
the  size  or  quantity  of  loops  ^an 
take  place.  Hence  where  the 
manufacture  is  extensively  pro- 
secuted, many  frames  may  be 
thrown  idle  by  every  vicissitude 
of  demand ;  and  where  a  poor 
mechanic  does  purchase  his  own 
frame,  he  is  for  ever  limited  to 
the  same  kind  of  work.  The 
gauge,  as  it  is  called,  of  a  stock- 
ing-frame   is     regulated    by    the 

..        .    ,        - ,       ,  ,        ,        —^     number  of    loops    contained    in 

three  mches  of  breadth,  and  varies  very  much ;  the  coarsest  frames  in  common  use  being 
about  what  are  termed  Fourteens,  and  the  finest  employed  in  great  extent  about 
Forties.  The  needles  are  of  iron  wire,  the  manufacture  of  which  is  very  simple ;  but 
long  practice  in  the  art  is  found  necessary  before  a  needle-maker  acquires  the  dexterity 
which  will  enable  him  both  to  execute  his  work  well,  and  in  sufficient  quantity  to  render 
his  labor  productive. 

The  process  of  making  the  needles  is  as  follows :— Good  sound  iron  wire,  of  a  proper 
fineness,  is  to  be  selected ;  that  which  is  liable  to  split  or  splinter,  either  in  filing, 
punching,  or  bending,  being  totally  unfit  for  the  purpose.  The  wire  is  first  to  be  cut 
mto  proper  lengths,  according  to  the  fineness  of  the  frame  for  which  the  needles  are 
designed,  coarse  needles  being  considerably  longer  than  fine  ones.  When  a  sufficient 
number  (generally  some  thousands)  have  been  cut,  the  wire  must  be  softened  as  much 
as  possible.  This  is  done  by  laying  them  in  rows  in  a  flat  iron  box,  about  an  inch 
deep,  with  a  close  cover ;  the  box  being  filled  with  charcoal  between  the  strata  of  wires. 
This  box,  being  placed  upon  a  moderate  fire,  is  gradually  heated  until  both  the  wires 
and  charcoal  have  received  a  moderate  red  heat,  because,  were  the  heat  increased  to  what 
smiths  term  the  white  heat,  the  wire  would  be  rendered  totally  unfit  for  the  subsequent 
processes  which  it  has  to  undergo,  both  in  finishing  and  working.  When  the  box  ha« 
been  sufficiently  heated,  it  may  be  taken  from  the  fire,  and  placed  among  hot  ashes, 
until  both  ashes  and  box  have  gradually  cooled;  for  the  slower  the  wires  cool,  the 
softer  and  easier  wrought  they  will  be.  When  perfectly  cool,  the  next  process  is  to 
punch  a  longitudinal  groove  in  the  stem  of  every  needle,  which  receives  the  point  or 
barb,  when  depressed.  This  is  done  by  means  of  a  small  engine  worked  by  the  power 
of  a  screw  and  lever.      The  construction  of  these  engines  is  various;  but  a  profile 

elevation  of  one  of  the  most  simple  and  com- 
monly used  will  be  found  in  fig,  763.  It 
consists  of  two  very  strong  pieces  of  malle- 
able iron,  represented  at  a  and  c,  and  these 
two  pieces  are  connected  by  a  strong  well- 
fitted  joint  at  B.  The  lower  piece,  or  sole  of 
the  engine  at  c,  is  screwed  down  by  bolts  to 
a  strong  board  or  table,  and  the  upper  piece 
A  will  then  rise  or  sink  at  pleasure,  upon  the 
joint  B.  In  order  that  a  may  be  very  steady 
in  rising  and  sinkin?,  which  is  indispensable 
.         .     ^  .  .  to  its   correct   operation,  a  strong    bridle  of 

iron,  whicn  is  shown  m  section  at  e,  is  added  to  confine  it,  and  direct  its  motion.  In 
the  upper  part  of  this  bridle  is  a  female  screw,  through  which  the  forcing  screw  passes, 
which  IS  turned  by  the  handle  or  lever  d.    To  the  sole  of  the  engine  c  is  fixed  a  bolster 


HOSIERY. 


1021 


763 


of  tempered  steel,  with  a  small  groove  to  receive  the  wire,  which  is  to  be  punched ;  and 
in  the  upper  or  moving  part  a,  is  a  sharp  chisel,  which  descends  exactly  into  the  groove, 
when  a  is  depressed  by  the  screw.  These  are  represented  at  f,  and  above  h.  At  g  is  a 
strong  spring,  which  forces  up  the  chisel  when  tho  pressure  of  the  screw  is  removed.  The 
appearance  of  the  groove,  when  the  punching  is  finished,  will  be  rendered  familiar  by 
inspecting  fig.  764,  p.  1022.  When  the  punching  is  finished,  the  wires  are  to  be  brought 
to  a  fine  smooth  point  by  filing  and  burnishing,  the  latter  of  which  should  be  very  com- 
pletely done,  as,  besides  polishing  the  wire,  it  tends  greatly  to  restore  that  spring  and 
elasticity  which  had  been  removed  by  the  previous  operation  of  softening.  The  wire  is 
next  to  be  bent,  in  order  to  form  the  hook  or  barb ;  and  this  is  done  with  a  small  piece 
of  tin  plate  bent  double,  which  receives  the  point  of  the  wire,  and  by  its  breadth  regu- 
lates the  length  of  the  barb.  The  stem  of  the  needle  is  now  flattened  with  a  small 
hammer,  to  prevent  it  from  turning  in  the  tin  socket  in  which  it  is  afterwards  to  be  cast ; 
and  the  point  of  the  barb  being  a  little  curved  by  a  pair  of  small  pliers,  the  needle  is 
coinpleteti. 

In  order  to  fit  the  needles  for  the  frame,  they  are  now  cast  into  the  tin  sockets,  or  leads, 
as  they  are  called  by  the  workmen ;  and  this  is  done  by  placing  the  needles  in  an  iron 
mould,  which  opens  and  shuts  by  means  of  a  joint,  and  pouring  in  the  tin  while  in  a 
stale  of  fusion.  In  common  operations,  two  needles  are  cast  into  the  same  socket.  The 
form  of  the  needle,  when  complete  and  fitted  to  its  place  in  the  frame,  will  be  seen  iu 

fig.  765,  which  is  a  profile  section 
of  the  needle-bar,  exhibiting  one 
needle.  In  this  figure  a  section  ol 
the  pressure  is  represented  at  f; 
the  needle  appears  at  g,  and  the 
socket  or  level  at  k.  At  h,  is  a 
section  of  the  needle-bar,  on  the 
fore  part  of  which  is  a  small  plate 
of  iron  called  a  verge,  to  regulate  the  position  of  the  needles.  When  placed  upon  the 
bar  resting  against  the  verge,  another  plate  of  iron,  generally  lined  with  soft  leather,  is 
screwed  down  upon  the  sockets  or  leads,  in  order  to  keep  them  all  fast.  This  plate  and 
the  screw  appear  at  i.  When  the  presser  at  f  is  forced  down  upon  the  barb,  this  sinks 
into  the  groove  of  the  stem,  and  the  needle  is  shut ;  when  the  presser  rises,  the  barb  opens 
ftgain  by  its  own  elasticity. 

The  needles  or  hooks  being  all  properly  fitted,  the  next  part  of  the  stocking-frame  to 
which  attention  ought  to  be  paid,  is  the  machinery  for  forming  the  loops ;  and  this  con- 
sists of  two  parts.  The  first  of  these,  which  sinks  between  every  second  or  alternate 
needle,  is  .epresented  at  o,  fig.  762,  and  is  one  of  the  most  important  parts  of  the  whole 
machine.  It  consists  of  two  moving  parts ;  the  first  being  a  succession  of  horizontal 
levers  moving  upon  a  common  centre,  and  called  jacks,  a  term  applied  to  vibrating  levers 
in  various  kinds  of  machinery  as  well  as  the  stockins-frame.  One  only  of  these  jacks 
can  be  represented  in  the  profile  fig.  762 ;  but  the  whole  are  distinctly  shown  in  a  hori- 
Eontal  position  in  fig.  766 ;  and  a  profile  upon  a  very  enlarged  scale  is  given  in  fig.  767. 

jEi ?  766 


ii 


1022 


HOSIERY. 


The  jack  shown  in  fig.  762,  extends  horizontally  from  o  to  i,  and  the  centre  of  motion 
is  at  R.  On  the  front,  or  right  hand  part  of  the  jack  at  o,  is  a  joint  suspendins:  a  very 
thin  plate  of  polished  iron,  which  is  termed  a  sinker.  One  of  these  jacks  and  sinkers  is 
allotted  for  every  second  or  alternate  needle.  The  form  of  the  sinker  will  appear  at  s, 
fig.  767  ;  and  in  order  that  all  may  be  exactly  uniform  in  shape,  they  are  cut  oat  and 
finished  between  two  stout  pieces  of  iron,  which  serve  as  moulds  or  gauges  to  direct  the 
frame-smith.  The  other  end  of  the  jack  at  i,  is  tapered  to  a  point ;  and  when  the  jacks 
are  in  their  horizontal  position,  they  are  secured  by  small  iron  springs,  one  of  which  is 
represented  at  i,  fig.  762,  each  spring  having  a  small  obtuse  angled  notch  to  receive  the 
point  cf  the  jack,  against  which  it  presses  by  its  own  elasticity.  In^g.  767  the  centre  is 
at  R ;  the  pointed  tail  is  omitted  for  want  of  room,  the  joint  is  at  o,  and  the  throat  of  the 
sinker,  which  forms  the  loop,  is  at  s.  The  standards  at  r,  upon  which  the  jack  moves, 
are  called  combs,  and  consist  of  pieces  of  flat  smooth  brass,  parallel  to,  and  equidistant 
from  each  other.  The  cross-bar  r,  which  contains  the  whole,  is  of  iron,  with  a  perpen- 
dicular edge  or  rim  on  each  side,  leaving  a  vacancy  between  them,  or  a  space  to  receive 
the  bottom  part  or  tails  of  the  combs.  The  combs  are  then  placed  in  the  bar,  with  a  flat 
piece  of  brass  called  a  countercomb,  between  each,  to  ascertain  and  preserve  their  distances 
from  each  other.  These  conntercombs  are  exactly  of  the  same  shape  as  the  combs,  but 
have  no  tails.  When  both  combs  and  conntercombs  are  placed  in  the  bar,  it  is  luted 
with  clay  so  as  to  form  a  mould,  into  which  is  poured  a  sufficient  quantity  of  melted  tin. 
When  the  tin  has  had  time  to  cool,  the  countercombs  having  no  tails  are  easily  taken  out, 
and  the  combs  remain  well  fastened  and  secured  by  the  tin,  which  has  been  fused  entirely 
round  them.  Thus  they  form  a  succession  of  standards  for  the  jacks ;  and  a  hole  being 
drilled  through  each  jack  and  each  comb,  one  polished  wire  put  through,  serves  as  a  com 
mon  centre  for  the  whole. 

The  jack  sinkers  being  only  used  for  every  alternate  or  second  needle,  in  order  to 
complete  this  part  of  the  apparatus,  a  second  set  of  sinkers  is  employed.  These  are,  in 
form  and  shape,  every  way  the  same  as  the  jack  sinkers,  but  they  are  jointed  at  the  top 
into  pieces  of  tin,  all  of  which  are  screwed  to  the  sinker  bar  h,  fig.  762  ;  and  thus  a 
sinker  of  each  kind  descends  between  the  needles  alternately.  By  these  sinkers  the 
loops  are  formed  upon  all  the  needles,  and  the  reason  of  two  sets  different  in  operation 
being  employed,  will  be  assigned  in  describing  the  mode  of  working  the  frame.  The 
presser  of  the  operation,  of  which  something  has  already  been  said,  appears  at  f;  and 
of  the  two  arms  which  support  and  give  motion  to  it,  one  appears  very  plainly  at  e,  its 
centre  of  motion  being  at  c.      The  circular  bend  given  to  these  arms,  besides  having  an 


HOSIERY. 


768 


A 


=     B 


El 


TT 


n 


B 


1 1    ]i.ii.i|.ii.!j.J-iHlH)-||-|-i-j-i-"-«-»-<^i-ii  I W 


% 


764 


ornamental  eifect,  is  very  useful, 
in  order  to  prevent  any  part  from 
interfering  with  the  other  parts 
which  are  behind,  by  elevating 
them  entirely  above  them.  The 
extremities  of  these  arms  at  the 
termination  of  the  bends  behind, 
are  connected  by  a  cross  bar, 
which  has  also  a  circular  bend 
in  the  middle,  projecting  down- 
wards, for  a  reason  similar  to  that 
already  assigned.  This  bend  is 
concealed  in  fig.  762,  but  visible 
in  the  front  elevation,  fig.  768. 
From  the  middle  of  the  bend, 
the  presser  is  connected  with  the 
middle  treadle  by  a  depending 
wire  appearing  at  Wjfig.  762,  and 
thus,  by  the  pressure  of  that 
treadle,  the  presser  is  forced  down 
to  close  the  barbs  of  the  needle. 
The  re-ascent  of  the  presser  is 
sometimes  effected  by  means  of 
a  counterpoising  weight  passing 
over  a  pulley  behind ;  and  some- 
times by  the  reaction  of  a  wooden 
spring,  formed  of  a  strong  hoop 
like  that  represented  at  k.  The 
latter  of  these  is  preferred,  espe- 
cially by  the  Nottingham  hosiers, 
because,  as  they  assert,  it  makes 
the  presser  spring  up  with  greater 


1023 


rapidity,  and  consequently  saves  time  in  working.  How  far  this  may  be  praclichlly  the 
case,  it  would  be  superfluous  here  to  investigate ;  but  it  is  obvious  that  the  wooden  spring, 
if  very  stiff,  must  add  much  to  the  hosier's  exertion  of  his  foot,  already  exercised  against 
the  united  sprin?  of  all  his  barbs;  and  this  inconvenience  is  much  complained  of  by  those 
who  have  been  accustomed  to  work  with  the  counterpoise. 

At  L  are  two  pulleys  or  wheels,  of  different  diameters,  moving  upon  a  common  centre, 
by  which  the  jack  sinkers  are  relieved  from  the  back  springs,  and  thrown  downwards  to 
form  the  loops  upon  the  needles.  About  the  larger  wheel  is  a  band  of  whipcord,  pass- 
ing twice  round,  the  extremities  of  which  are  attached  to  what  is  called  the  slur,  which 
disengages  the  jacks  from  the-  back  springs.  The  smaller  pulley,  by  another  band, 
communicates  with  the  right  and  left  treadle;  so  that  these  treadles,  when  pressed 
alternately,  turn  the  pulleys  about  in  an  inverted  order.  The  directions  of  these  bands 
also  appear  more  plainly  in  the  front  elevation,  fig.  768.  The  construction  of  the  slur, 
and  its  effect  upon  the  jacks,  will  also  be  rendered  apparent  by  fig.  769.  In  this 
figure,  eight  jacks  are  represented  in  section,  the  tail  part  of  three  of  which,  1,  2,  3,  are 
thrown  up  by  the  slur  in  its  progress  from  left  to  right ;  the  fourth  is  in  the  act  of 
rising,  and  the  remaining  four,  5,  6,  7,  and  8,  are  still  unacted  upon,  the  slur  not  yei 
having  reached  them.  As  the  slur  acts  in  the  direction  of  the  dotted  line  x,  x,  fig.  766, 
behind  the  centres  of  the  jacks,  it  is  hardly  necessary  to  remark,  that  this  forcing  up  of 
the  tails  must  of  course  depress  the  joints  by  which  the  sinkers  in  front  are  suspended. 
The  jack  sinkers  falling  successively  from  the  loops  on  every  alternate  needle,  in  the  way 
^  f  g     represented  at  fig.  770,  where  both 

kinds  of  sinkers  appear  in  section,  the 
light  part  expressing  what  is  above 
the  point  at  which  the  throat  of  the 
sinker  operates  upon  the  thread,  and 
the  dark  part  what  is  below.  The 
second  set,  or,  as  they  are  called,  the 
lead  sinkers,  from   the  manner  of 


i 


770 


^^^^^^ 


I 


jointing  them,  and  suspending  them  from  the  bar  above,  appear  still  elevated ;  the 
position  of  the  bar  being  represented  by  the  line  a,  b.  But  when  these  are  pulled  down 
to  the  level  of  the  former  by  the  operator's  hands,  the  whole  looping  will  be  completed, 
and  the  thread  c,  d,  which  is  still  slack,  will  be  brought  to  its  full  and  proper  degree  of 
tension,  which  is  regulated  by  stop  screws,  so  as  to  be  tempered  or  altered  at  pleasure. 

The  sinking  of  this  second  set  of 

sinkers,  may  be  easily  explained  by 

771  /^^^^^N^      _-^x^  fig-'JIl.    Thedirection  of  the  sink- 

ers is  expressed  by  the  line  e  ;  the 
bar  from  which  they  are  suspended 
will  be  at  A ;  the  top  frame  is  in  the 
direction  from  A  to  b;  the  back 
standards  at  d,  and  the  joint  at  b,  is 
the  centre  of  motion.  If  e  is  pulled 
perpendicularly  downwards,  the  spring  c  will  be  contracted,  and  its  upper  extreme  point 
G,  will  be  brought  nearer  to  its  lower  extreme  point  f,  which  is  fixed.  Again,  when  the 
force  which  has  depressed  e  is  removed,  the  spring  c  will  revert  to  its  former  state,  and 
the  sinkers  will  rise.  The  raising  of  the  jack  sinkers  and  jacks  takes  place  at  the  same 
time,  by  the  hosier  raising  his  hands ;  and  for  the  cause  of  this  we  must  revert  to  fig. 
766.  The  lead  sinkers  in  rising  lay  hold  of  notches,  which  raise  the  extreme  parts  of 
the  set  of  jacks  z,  z,  which  are  called  half-jacks.  Between  the  extremities  of  these  at  z,  z, 
is  a  cross  bar,  which,  in  descending,  presses  all  the  intermediate  jacks  behind  the  common 
centre,  and  restores  them  to  their  original  posture,  where  they  are  secured  by  the  back 
springs,  until  they  are  again  relieved  by  the  operation  of  the  slur  recrossing  at  the  next 
course. 

Working  of  the  frame. — In  order  to  work  a  frame,  the  whole  apparatus  being  previ- 
ongly  put  into  complete  order,  the  hosier  places  himself  on  the  seat  b  in  front,  and  pro- 
vides himself  with  a  bobbin  of  yarn  or  stuff.  This  bobbin  he  places  loosely  on  a  vertical 
pin  of  wire,  driven  into  one  side  of  the  frame  contiguous  to  the  needles,  so  that  it  may 
turn  freely  as  the  stuff  is  unwound  from  it.  Taking  the  thread  in  his  hand,  he  draws  it 
loosely  along  the  needles,  behind  the  barbs,  and  under  the  throats  of  the  sinkers.  He 
then  presses  down  one  of  the  treadles  to  pass  the  slur  along,  and  unlock  the  jacks  from 
the  back  springs,  that  they  may  fall  in  succession.  When  this  is  done,  the  number  of 
loops  thus  formed  is  doubled  by  bringing  down  the  lead  sinkers,  and  the  new  formed 
loops  are  lodged  under  the  barbs  of  the  needles  by  bringing  forward  the  sinkers.  The 
preceding  course,  and  former  fabric,  being  then  again  pushed  back,  the  barbs  arc  shut 
by  depressing  the  middle  treadle,  and  forcing  down  the  presser  upon  the  needles.  The 
former  work  is  now  easily  brought  over  the  shut  neeidles,  after  which  by  raising  the 


i'i 
if 


1024 


HOSIERY. 


hands,  both  sets  of  sinkers  are  raised ;  the  jacks  are  locked  by  the  back  springs,  and  the 
hosier  goes  on  to  another  course. 

From  this  it  will  be  apparent,  that  the  remark  made  in  the  outset  is  well  founded, 
that  there  are,  ia  reality,  no  complicated  or  difficult  movements  in  the  stocking-frame. 
Almost  the  whole  are  merely  those  of  levers  moving  upon  their  respective  fulcra,  excepting 
that  of  the  carriage  which  gives  the  horizontal  motion  to  the  sinkers,  and  that  is  merely 
an  alternate  motion  on  four  wheels.  Yet  the  frame  is  a  machine  which  requires  con- 
siderable experience  and  care,  both  to  work  it  to  advantage,  and  also  to  keep  it  in  good 
order.  This  circumstance  arises  greatly  from  the  small  compass  in  which  a  number  of 
moving  parts  must  be  included.  Owing  to  this,  the  needles,  unless  cautiously  and  deli- 
cately handled,  are  easily  bent  or  injured.  The  same  circumstance  applies  with  equal 
or  greater  force  to  the  sinkers,  which  must  be  so  very  thin  as  to  be  easily  injured.  But 
as  these  must  work  freely,  both  in  a  perpendicular  and  horizontal  direction  between  the 
needles,  in  a  very  confined  and  limited  space,  the  slightest  variation  in  either,  from  beini? 
truly  and  squarely  placed,  unavoidably  injures  the  others.  When  a  hosier,  either  igno- 
rant of  the  mechanical  laws,  of  their  relation  to  each  other,  or  too  impatient  to  wait  for 
the  assistance  of  another,  attempts  to  rectify  defects,  he  in  most  cases  increases  them  ten- 
fold, and  renders  the  machine  incapable  of  working  at  all,  until  repaired  by  some  more 
experienced  person.  This  circumstance  has  given  rise  to  a  set  of  men  employed  in  this 
trade,  and  distinguished  by  the  name  of  upsetters;  and  these  people,  besides  setting  new 
frames  to  work,  have  frequently  more  employment  in  repairing  old  ones  injured  by  want 
of  care  or  skill,  than  many  country  apothecaries,  who  live  in  unhealthy  parishes,  find  in 
tampering  with  the  disorders  of  mankind. 

It  seems  unnecessary  to  go  further  into  detail  respecting  a  machine  so  well  known, 
and  which  requires  practical  attention  even  more  than  most  others.  It  may,  therefore, 
be  sufficient  to  describe  shortly  some  of  its  varieties,  the  most  simple  and  common  of 
which  is  the  rib  stocking-frame. 

Rib  stocking-frame.  —  This  frame,  which,  next  to  the  common  frame,  is  most  exten- 
sively in  use,  is  employed  for  working  those  striped  or  ribbed  stockings,  which  are  very 
common  in  all  the  different  materials  of  which  hosiery  is  formed.  In  principle  it  does 
not  differ  from  the  common  frame,  and  not  greatly  in  construction.  The  preceding  gen- 
eral description  will  nearly  apply  to  this  machine  with  equal  propriety  as  to  the  former; 
that  part,  however,  by  which  the  ribs  or  stripes  are  formed,  is  entirely  an  addition,  and 
to  the  application  of  this  additional  machinery  it  may  be  proper  to  pay  the  chief  atten- 
tion, referring  chiefly  to  Jig.  768,  which  is  a  front  elevation. 

This  figure  has  been  already  referred  to  for  the  illustration  of  those  parts  of 
the  machinery  which  are  common  to  both,  and  those  parts  therefore  require  no  reca- 
pitulation. The  principle  of  weaving  ribbed  hosiery  possesses  considerable  affinity  to 
that  which  subsists  in  the  weaving  of  that  kind  of  cloth  which  is  distinguished  by  the 
name  of  tweeling,  for  the  formation  of  stripes,  with  some  variation  arising  merely  from 
the  different  nature  of  the  fabric.  In  cloth  weaving,  two  different  kinds  of  yarn  inter- 
secting each  other  at  right  angles,  are  employed ;  in  hosiery  only  one  is  used.  In  the 
tweeling  of  cloth,  striped  as  dimity,  in  the  cotton  or  kerseymere,  and  in  the  woollen  man- 
ufacture, the  stripes  are  produced  by  reversing  these  yarns.  In  hosiery,  where  only  one 
kind  of  yarn  is  used,  a  similar  effect  is  produced  by  reversing  the  loops.  To  effect  this 
reversing  of  the  loops,  a  second  set  of  needles  is  placed  upon  a  vertical  frame,  so  that 
the  bends  of  the  hooks  may  be  nearly  under  those  of  the  common  needles.  These 
needles  are  cast  into  tin  moulds,  pretty  similar  to  the  former,  but  more 
oblique  or  bevelled  towards  the  point,  so  as  to  prevent  obstructions  in 
working  them.  They  are  also  screwed  to  a  bar  of  iron,  generally  lighter 
than  the  other,  and  secured  by  means  of  plates  :  this  bar  is  not  fixed, 
but  has  a  pivot  in  each  end,  by  means  of  which  the  bar  may  have  a  kind 
of  oscillatory  motion  on  these  pivots.  The  two  frames  of  iron  support  this 
bar;  that  in  which  it  oscillates  being  nearly  vertical,  but  inclined  a  little 
towards  the  other  needles.  Fig.  772,  which  is  a  profile  elevation,  will 
serve  to  illustrate  the  relative  position  of  each  bar  to  the  other.  The 
lower  or  horizontal  frame,  the  ends  only  of  which  can  be  seen  in  Jig. 
768  under  a  a,  appears  in  profile  in  Jig.  772,  where  it  is  distinguished 
by  rf.  The  vertical  frame  at  a  is  attached  to  this  by  two  centre  screws, 
which  serve  as  joints  for  it  to  move  in.  On  the  top  of  this  frame  is  the 
rib-needle  bar  at  /,  in  Jigs.  762  and  772,  and  one  needle  is  represented 
in  Jig.  772  at  /.  At  g  is  a  small  presser,  to  shut  the  barbs  of  the  rib- 
needles,  in  the  same  manner  as  the  large  one  does  those  of  the  frame. 
At  h  is  one  of  the  frame  needles,  to  show  the  relative  position  of  the  one 
set  to  the  other.  The  whole  of  the  rib-bar  is  not  fitted  with  needles 
like  the  other;  for  here  needles  are  only  placed  where  ribs  or  stripes 
are  to  be  formed,  the  intervals  being  fillel  up  with  blank  leads,  that  is 


HOT-FLUE. 


1025 


to  say,  with  sockets  of  the  same  shape  as  the  others,  but  without  needles ;  being  merely 
designed  to  fill  the  bar  and  preserve  the  intervals.  Two  small  handles  depend  from  the 
needle  bar,  by  which  the  oscillatory  motion  upon  the  upper  centres  is  given.  The  rising 
and  sinking  motion  is  communicated  to  this  machine  by  chains  which  are  attached  ic 
iron  sliders  below,  and  which  are  wrought  by  the  hosier's  heel  when  necessary.  The 
pressure  takes  place  partly  by  the  action  of  the  small  presser,  and  partly  by  the  motion 
of  the  needles  in  descending.  A  small  iron  slider  is  placed  behind  the  rib-needles,  whidi 
rises  as  they  descend,  and  serves  to  free  the  loops  perfectly  from  each  other. 

In  the  weaving  of  ribbed  hosiery,  the  plain  and  rib  courses  are  wrought  a.ternately. 
When  the  plain  are  finished,  the  rib-needles  are  raised  between  the  others,  but  no  addi- 
tional stuff  is  supplied.  The  rib-needles,  intersecting  the  plain  ones,  merely  lay  hold  of 
the  last  thread,  and,  by  again  bringing  it  through  that  which  was  on  the  rib-needle  be- 
fore, give  it  an  additional  looping,  which  reverses  the  line  of  chaining,  and  raises  the  rib 
above  the  plain  intervals,  which  have  only  received  a  single  knittin?. 

HOT-FLUE  is  the  name  given  in  England  to  an  apartment  heated  by  stoves  or 
ateam  pipes,  in  which  padded  and  printed  calicoes  are  dried  hard.     Fig.  773  represents 


the  simplest  form  of  such  a  flue,  heated  Ly  the  vertical  round  iron  stove  c,  from  whose 
top  a  wide  square  pipe  proceeds  upwards  in  a  slightly  inclined  direction,  which  receives 
the  current  of  air  heated  by  the  body  and  capital  of  the  stove.  In  this  wide  channe 
there  are  pulleys,  with  cords  or  bands  which  suspend  by  hooks,  and  conduct  the  web  of 


1026 


HOT-FLQE. 


ealico,  from  the  entrance  at  b,  where  the  operative  sits,  to  near  the  point  a,  and  back 
again.  This  circuit  may  be  repeated  once  or  oftener  till  the  goods  are  perfectly  dried. 
At  D  the  driving  pulley  connected  virith  the  main  shaft  is  shown.  Near  the  feet  of  the 
operative  is  the  candroy  or  reel  upon  which  the  moist  goods  are  rolled  in  an  endless  web; 
go  that  their  circulation  in  the  hot-air  channel  can  be  continued  without  interruption,  a.^ 
long  as  may  be  necessary. 

Fig.  774  is  a  cross  section  of  the  apparatus  of  the  regular  hot-flue,  as  it  is  mounted 
774  in   the    most    scientific   calico    works    of 

England,  those  of  James  Thomson,  Esq., 
of  Primrose,  near  Clilheroe,  Lancashire, 
a  a  a  a,  is  an  arched  apartment,  nearly  30 
yards  long,  by  13  feet  high,  and  10  feet 
wide.  Through  about  one  half  of  this 
gallery  there  is  a  horizontal  floor  sup- 
ported on  arches,  above  which  is  the  driest 
space,  through  which  the  goods  are  finally 
passed  before  they  escape  from  the  hot-flue, 
after  they  have  been  previously  exposed  to 
the  hot  but  somewhat  moist  air  of  the 
lower  compartment.  A  large  square  flue 
covered  with  cast-iron  plates  runs  along 
the  whole  bottom  of  the  gallery.  It  is 
divided  into  two  loi.j,  parallel  vaults, 
whose  sections  are  seen  at  i*,  m,  Jig.  774, 
covered  with  the  cast-iron  plates  v  v, 
grooved  at  their  ends  into  one  another.  The 
thickness lof  these  plates  is  increased  pro- 
gressively as  they  come  nearer  to  the  fire- 
place or  furnace.  There  are  dampers  which  regulate  the  draught,  and  of  course  the  heat 
of  the  stove,  h  h  are  the  air-passages  or  vent-holes,  left  in  the  side  walls,  and  which  by 
means  of  a  long  iron  rod,  mounted  with  iron  plates,  may  be  opened  or  closed  together 
to  any  decree,  fe  k  are  the  cast-iron  supports  of  the  tinned  brass  rollers  which  guide 
the  goods  along,  and  which  are  fixed  to  the  cross  pieces  represented  by  r  r,  Jig.  774. 
1 1  are  iron  bars  for  supporting  the  ventilators  or  fans  (see  the  fan  under  Foundry). 
These  fans  are  here  enclosed  within  a  wire  grating.  They  make  about  300  turns  per 
minute,  and  expel  the  moist  air  with  perfect  effect,  s  indicates  the  position  of  the  win- 
dows, which  extend  throughout  the  length  of  the  building,  t  is  &  gas-light  jet,  placed  at 
the  side  of  each  window  to  supply  illumination  for  night  work. 

The  piece  is  stretched  along  the  whole  extent  of  the  gallery,  and  runs  through  it  in 
the  course  of  one  minute  and  a  half;  being  exposed  during  its  passage  to  the  heat  of 
212°  Fahr. 

In  Jig.  775,  A  is  the  iron  door  of  entrance  to  the  hot-flue  gallery ;  at  6  is  the  pad- 
ding machine,  where  the  goods  are  imbued  with  the  general  mordant.      The  speed  of 

775 


this  machine  may  be  varied  by  means  of  the  two  conical  drums  c  c,  which  drive  it ;  since 
when  the  band  c  c  is  brought,  by  its  forks  and  adjusting  screws,  nearer  to  the  narrow 
end  of  the  lower  drum,  the  cylinder  upon  the  same  shaft  with  the  latter  is  driven 
quicker;  and  vice  versa.  Over  d  d  the  cords  are  shown  for  drawing  the  drum  mechan- 
ism into  gear  with  the  main  shaft  band,  r  f  e;  or  for  throwing  it  out  of  gear.  The 
pulleys  F  F  carry  the  bands  which  transmit  the  motion  to  the  padding  machine.  A 
cylindrical  drum  exterior  to  the  hot-flue,  covered  with  flannel,  serves  to  receive  the  end 
of  the  series  of  pieces,  and  to  draw  them  through  the  apartment.    This  mode  of  drying 


JACaUARD. 


1027 


the  padded  calicoes  requires  for  each  piece  of  28  yards,  3  pounds  of  coals  for  the  furnace 
when  a  fan  is  employed,  and  four  pounds  without  it. 

HYDRATES ;  are  compounds  of  the  oxides,  salts,  <fec.  with  water  in  definite  or  equiva- 
lent proportions.  Ihus  slaked  lime  consists  of  one  atom  of  quick  lime  =  28,  -f-  one  atom 
of  water  =  9,  of  which  the  sum  is  37  on  the  hydrogen  scale. 

HYDRAULIC  PRESS.    See  Oil,  Press,  and  Stearixe. 

H  YDRYODIC  ACID ;  {Acide  Hydriodique,  Fr, ;  Hydriodsatire,  Germ.)  is  an  acid  formed 
by  the  combination  of  99*2 1  parts  of  iodine,  and  0'79  hydrogen.  When  pure,  it  occurs  in 
the  gaseous  state,  but  it  combines  with  water,  like  the  hydrochloric  or  muriatic  acid  gas, 
into  a  liquid  acid. 

HYDROCHLORIC  ACID;  the  new  chemical  name  of  muriatic  acid,  which  see. 

HYDROGEN;  (Eng.  and  Fr. ;  Wasserstoff,  Germ.)  an  undecompounded  gaseous  body; 
the  lightest  of  all  ponderable  matter,  whose  examination  belongs  to  chemistry. 

HYDROMETER;  an  instrument  for  ascertaining  the  specific  gravities  of  liquids. 
Baurae's  hydrometer,  which  is  much  used  in  France,  and  other  countries  of  the  contment 
of  Europe,  when  plunged  in  pure  water,  at  the  temperature  of  58°  Fahr.,  marks  0  upon 
its  scale;  in  a  solution  containing  15  per  cent,  of  common  salt  (chloride  of  sodium),  and 
85  of  water  by  weight,  it  marks  15° ;  so  that  each  degree  is  meant  to  indicate  a  density 
corresponding  to  one  per  cent,  of  that  salt.  See  Areometer,  for  comparative  tables  of 
hydrometers. 

HYDROSULPHURETS ;  chemical  compounds  of  bases  with  sulphuretted  hy- 
drogen. 

HYMENGEA  COURBARIL;  a  tree  growing  in  South  America,  from  which  the  resin 
anime  exudes. 

HYOSCIAMUS  NIGER.  Henbane  is  a  plant  used  in  medicine,  from  which  modern 
chemistry  has  extracted  a  new  crystalline  vegetable  principle  called  hyoscia7mne,  which 
is  very  poisonous,  and  when  applied  in  solution  to  the  eye,  determines  a  remarkable 
dilatation  of  the  pupil ;  as  belladonna  also  does. 

HYPOSULPHATES ;  Hyposulphites  ;  saline  compounds  of  the  hyposulphuric  or 
hyposulphurous  acid  with  bases. 

HYPEROXYMURIATES;  the  old  and  incorrect  name  for  Chlorates. 

HYPOSULPHATE  of  SODA.  Pure  crystallized  carbonate  of  soda  is  dried  as  much 
as  possible,  and  reduced  to  a  fine  powder ;  1  lb.  of  it  is  then  mixed  with  10  ozs.  of  flowers 
of  sulphur,  and  the  mixture  is  heated  in  a  glass  or  porcelain  dish,  gradually,  until  the 
sulphur  melts.  The  mass  which  cakes  together  is  kept  at  this  temperature  and  is 
divided,  stirred  and  mixed,  in  order  that  each  uart  may  be  brought  into  contact  with  the 
atmosphere.  The  sulphuret  of  sodium  formed  passes,  under  these  circumstances,  by  the 
absorption  of  oxygen  from  the  atmosphere,  with  a  slight  incandescence,  gradually  into 
sulphite  of  soda.  It  is  dissolved  in  water;  filtered,  the  liquid  immediately  boiled  with 
flowers  of  sulphur ;  the  filtered,  nearly  colourless,  strongly  concentrated  liquid  affords 
hyposulphate  of  soda  in  very  pure  and  beautiful  crystals,  and  in  large  quantity. 

When  the  mixture  is  heated  too  quickly,  some  sulphur  is  easily  burnt ;  there  then 
remains  a  portion  of  undecoraposed  carbonate  of  soda,  which  contaminates  the  hyposul- 
phite in  the  first  crystallization,  but  which  may  very  readily  be  separated  from  it 

HYPOSULPHITE  OF  SODA.  This  salt,  so  extensively  used  in  the  practice  of 
Dagxierreotyping,  may  be  easily  prepared  in  quantities  by  the  following  process :— Mix 
one  pound  of  finely  pulverised  ignited  carbonate  of  soda  with  ten  ounces  of  flowers  of 
sulphur,  and  heat  the  mixture  slowly  in  a  porcelain  dish  till  the  sulphur  melts.  Stir  the 
fused  mass  so  as  to  expose  all  its  parts  freely  to  the  atmosphere,  whereby  it  passes  from 
the  state  of  a  sulphuret,  by  the  absorption  of  atmospherical  oxygen,  into  that  of  a 
sulphite,  with  the  phenomenon  of  very  slight  incandescence.  Dissolve  in  water, 
filter  the  solution,  and  boil  it  immediately  along  with  flowers  of  sulphur.  The  filtered 
concentrated  saline  liquid  will  afford,  on  cooling,  a  large  quantity  of  pure  and  beautiful 
crystals  of  hyposulphite  of  soda. 


I.  &  J. 


JAOK,  called  also  jack  in  a  box,  and  hand-jack,  is  a  portable,  mechanical  instrument, 
consistmg  of  a  rack  and  pinion,  or  a  pair  of  claws  and  ratchet  bar,  moved  by  a  winch 
handle  for  raising  heavy  weights  a  little  way  off  the  ground. 

JACK  and  JACK-SINKERS,  are  parts  of  a  stocking  frame.     See  Hosiery. 

JACK-BACK,  is  the  largest  jack  of  the  brewer. 

JACQUARD.  A  peculiar  and  most  ingenious  mechanism,  invented  by  M.  Jacquart 
of  Lyons,  to  be  adapted  to  a  silk  or  muslin    loom  for  superseding  the  employment 

6  P2 


1028 


JACQUARD  LOOM. 


of  draw-boys,  in  weaving  figured  goods.  Independently  of  the  ordinary  play  of  the 
warp  threads  for  the  formation  of  the  ground  of  such  a  web,  all  those  threads  which 
should  rise  simultaneously  to  produce  the  figure,  have  their  appropriate  healds,  which  a 
child  formerly  raised  by  means  of  cords,  that  grouped  them  together  into  a  system,  in 
the  order,  and  at  the  time  desired  by  the  weaver.  Tliis  plan  evidently  occasioned  no 
little  complication  in  the  machine,  when  the  design  was  richly  figured ;  but  the  apparatus 
of  Jacquart,  which  subjects  this  manceuvre  to  a  regular  mechanical  operation,  and  derives 
its  motion  from  a  simple  pedal  put  in  action  by  the  weaver's  feet,  was  generally  adopted 
soon  after  its  invention  in  1800.  Every  common  loom  is  susceptible  of  receiving  this 
beautiful  appendage.  It  costs  in  France  200  francs,  or  8/.  sterling,  and  a  little  more  in 
this  country. 

Fig.  776.  is  a  front  elevation  of  this  mechanism,  supposed  to  be  let  down.  Fig.  ^11. 
is  a  cross  section,  shown  in  its  highest  position.  Fig.  778.  the  same  section  as  the  pre- 
ceding, but  seen  in  its  lower  position. 

A,  is  the  fixed  part  of  the  frame,  supposed  to  form  a  part  of  the  ordinary  loom ;  there 
are  two  uprights  of  wood,  with  two  cross-bars  uniting  them  at  their  upper  ends,  and 
leaving  an  interval  x  y  between  them,  to  place  and  work  the  movable  frame  b,  vibrating 
round  two  fixed  points  a  a,  placed  laterally  opposite  each  other,  in  the  middle  of  the 
space  X  y.  Jig.  776. 

c,  is  a  piece  of  iron  with  a  peculiar  curvature,  seen  in  front,  fig.  776.,  and  in  profile, 
figi.  777.  and  778.  It  is  fixed  on  one  side  upon  the  upper  cross-bar  of  the  frame  b,  and 
on  the  other,  to  the  intermediate  cross-bar  h  of  the  same  frame,  where  it  shows  an 
inclined  curvilinear  space  c,  terminated  below  by  a  semicircle. 

D,  is  a  square  wooden  axis,  movable  upon  itself  round  two  iron  pivots,  fixed  into  its 
two  ends  ;  which  axis  occupies  the  bottom  of  the  movable  frame  b.  The  four  fiices  of  this 
square  axis  are  pierced  with  three  round,  equal,  truly-bored  holes,  arranged  in  a  quin- 
cunx. The  teeth  a,  fig.  780.,  are  stuck  into  each  face,  and  con-espond  to  holes  a,  fig.  783., 
made  in  the  cards  which  constitute  the  endless  chain  for  the  healds;  so  that  in  the  suc- 
cts.<ive  application  of  the  cards  to  each  face  of  the  square  axis,  the  holes  pierced  in  one 
card  may  always  fall  opposite  to  those  pierced  in  the  other. 

The  right-hand  end  of  the  square  axis,  of  which  a  section  is  shown  in  double  size, 
fig.  779.,  carries  two  square  plates  of  sheet  iron  d,  kept  parallel  to  each  other  and  a  little 
apart,  by  four  spindles  c,  passed  opposite  to  the  corners.  This  is  a  kind  of  lanteni,  in 
whose  spindles,  the  hooks  of  the  levers  ff,  turninj^  round  fixed  points  g  (f  beyond  the 
right  hand  upright  a,  catch  hold,  either  above  or  below  at  the  pleasure  of  the  weaver, 
according  as  he  merely  pulls  or  lets  go  the  cord  z,  during  the  vibratory  movement  of  the 
frame  b. 

E  is  a  piece  of  wood  shaped  like  a  T,  the  stem  of  which  prolonged  upwards,  passes 
freely  through  the  cross-bar  6,  and  through  the  upper  cross-bar  of  the  frame  b,  which 
serves  as  guides  to  it.  The  head  of  the  T  piece  being  applied  successively  against  the 
two  spindles  e,  placed  above  in  a  horizontal  position,  first  by  its  weight,  and  then  by  the 
spiral  spring  h,  acting  from  above  downwards,  keeps  the  square  axis  in  its  position,  while 
it  permits  it  to  turn  upon  itself  in  the  two  directions.  The  name  press  is  given  to  the 
assemblage  of  all  the  pieces  which  compose  the  movable  frame  b  b. 

F  is  a  cross-bar  made  to  move  in  a  vertical  direction  by  means  of  the  lever  o,  in  the 
notches  or  grooves  i,  formed  within  the  fixed  uprights  a. 

H,  is  a  piece  of  bent  iron,  fixed  by  one  of  its  ends  with  a  nut  and  screw,  upon  the  cross- 
bar F,  out  of  the  vertical  plane  of  the  piece  c.  Its  other  end  carries  a  friction  roller  j, 
which  working  in  the  curvilinear  space  c  of  the  piece  c,  forces  this,  and  consequently  the 
frame  b,  to  recede  from  the  perpendicular,  or  to  return  to  it,  according  as  the  cross-bar  v 
is  in  the  top  or  bottom  of  its  course,  as  shown  mfigs.  777.  and  778. 

1,  cheeks  of  sheet  iron  attached  on  either  side  to  the  cross-bar  f,  which  serves  as  a  safe 
to  a  kind  of  claw  k,  composed  here  of  eight  small  metallic  bars,  seen  in  section  fig.  777. 
and  778.,  and  on  a  greater  scale  in  fig.  780. 

J,  upright  skewers  of  iron  wire,  whose  tops  bent  down  hook-wise  naturally  place 
themselves  over  the  little  bars  k.  The  bottom  of  these  spindles  likewise  hooked  in  the 
same  direction  as  the  upper  ones,  embraces  small  wooden  bars  /,  whose  office  is  to  keep 
them  in  their  respective  places,  and  to  prevent  them  from  twirling  round,  so  that  the 
uppermost  hooks  may  be  always  directed  towards  the  small  metallic  bars  upon  which 
they  impend.  To  these  hooks  from  below  are  attached  strings,  which  after  having  crossed 
a  fixed  board  m  n,  pierced  with  corresponding  holes  for  this  purpose,  proceed  next  to  be 
attached  to  the  threads  of  the  loops  destined  to  lift  the  warp  threads,  k  k,  horizontal 
spindles  or  needles,  aiTanged  here  in  eight  several  rows,  so  that  each  spindle  corresponds 
both  horizontally  and  vertically  to  each  of  the  holes  pierced  in  the  four  faces  of  the 
square  axis  d.  There  are  therefore  as  many  of  these  spindles  as  there  are  holes  in  one 
of  the  faces  of  the  square. 

Fig.  781.  represents  one  of  these  horizontal  spindles,    n  is  an  eyelet  through  which 


JACaUARD  LOOM. 


1029 


tlie  corresponding  vertical  skewer  passes,  o  another  elongated  eyelet,  through  which  a 
small  fixed  spindle  passes  to  serve  as  a  guide,  but  which  does  not  hinder  it  from  moving 
lengthwise,  within  the  limits  of  the  length  of  the  eyelet  p,  small  spiral  springs  placed 
in  each  hole  of  the  case  q  q,fig.  780.  They  serve  the  purpose  of  bringing  back  to  its 
primitive  position  every  corresponding  needle,  as  soon  as  it  ceases  to  press  upon  it. 


1030 


JACQUARD  LOOM. 


:^ 


nir^fUui 


780 


o- 

v^O 

d 

O 

d 

t 

0- 

« 

w 


P  o 


781 


» 


Fiq  782  represents  the  plan  of  the  upper  row  of  horizontal  needles.  l<ig.  783.  is  a 
fragment  of  the  endless  chain,  formed  with  perforated  cards,  which  are  made  to  circulate 
or  travel  by  the  rotation  of  the  shaft  d.  In  this  movement,  each  of  the  perforated  card^ 
whose  position,  form,  and  number,  are  determined  by  the  operation  of  tymg-up  of  the 
warp,  comes  to  be  applied  in  succession  against  the  four  faces  of  the  square  axis  or  drum, 
782  '^83 


»  o 


oe 


CjOO 


o 


o    oocq  coo     o 

sr«     °oe«<^  "o  ooo   oQ 
,o    0  «"  CO  0   coo     Oo  ""^  -    o 

■        "  ""  rii 


"e     o  O 

O  OCoO   o 

"     «> 


"^Soo^*^ 


o 


CP  "O    "  O  O  00  "  i 
O   0O„O  OOOo   g 


o   o  o        o"*  0  O  Co  0 


O     O      0 


o  oo. 


o  o 
c 


^  ri'J 


leaving  open  the  corresponding  holes,  and  covering  those  upon  the  face  of  the  axis,  which 
have  no  corresponding  holes  upon  the  card.  .    i         •  •        i 

Now  let  us  suppose  mat  tne  press  b  is  let  down  into  the  vertical  position  shown  in 
fig.  778 ;  then  the  card  applied  against  the  left  face  of  the  axis,  leaves  at  rest  or  un- 
touched the  whole  of  the  horizontal  spindles  (skewers),  whose  ends  correspond  to  these 
holes,  but  pushes  back  those  which  are  opposite  to  the  unpierced  part  of  the  card ;  thereby 
the  corresponding  upright  skewers,  3,  5,  6,  and  8,  for  example,  pushed  out  of  the  perpen- 
dicular, unhook  themselves  from  above  the  bars  of  the  claw,  and  remain  in  their  place, 
when  this  claw  comes  to  be  raised  by  means  of  the  lever  g  ;  and  the  skewers  1,  2, 4,  and 
7,  which  have  remained  hooked  on,  are  raised  along  with  the  warp  threads  attached  to 
them.  Then  by  the  passage  across  of  a  shot  of  the  color,  as  well  as  a  shot  of  the  common 
weft,  and  a  stroke  of  the  lay  after  shedding  the  warp  and  lowering  the  press  b,  an  element 
or  point  in  the  pattern  is  completed.  ■     c  j       ^^    x. 

The  following  card,  brought  round  by  a  quarter  revolution  of  the  axis,  finds  all  the 
needles  in  their  first  position,  and  as  it  is  necessarily  perforated  diflferently  from  the  pre- 
ceding card,  it  will  lift  another  series  of  warp  threads ;  and  thus  in  succession  for  all  ihe 
Other  cards,  which  compose  a  complete  system  of  a  figured  /attern. 

This  machine,  complicated  in  appearance,  and  which  requires  some  pains  to  be  under- 
stood, acts  however  in  a  very  simple  manner.  Its  whole  play  is  dependant  upon  the 
movement  of  the  lever  g,  which  the  weaver  himself  causes  to  rise  and  fall,  by  means  of 
a  peculiar  pedal ;  so  that  without  the  aid  of  any  person,  after  the  piece  is  properly  read 
in  and  mounted,  he  can  execute  the  most  complex  patterns,  as  easily  as  he  could  weave 
plain  goods ;  only  attending  to  the  order  of  his  weft  yarns,  when  these  happen  to  be  of 
different  colors. 

If  some  warp  yarns  should  happen  to  break  without  the  weaver  observing  them,  or 
should  he  mistake  his  colored  shuttle  yarns,  which  would  so  far  disfigure  the  pattern, 
he  must  undo  his  work.  For  this  purpose,  he  makes  use  of  the  lower  hooked  lever  /, 
whose  purpose  is  to  make  the  chain  of  the  card  go  backwards,  while  working  the  loom 
as  usual,  withdrawing  at  each  stroke  the  shot  both  of  the  ground  and  of  the  figure.  The 
weaver  is  the  more  subject  to  make  mistakes,  as  the  figured  side  of  the  web  is  downwards, 
and  it  is  only  with  the  aid  of  a  bit  of  looking-glass  that  he  takes  a  peep  of  his  work  from 
time  to  lime.  The  upper  surface  exhibits  merely  loose  threads  in  different  points,  accord- 
ing as  the  pattern  requires  them  to  lie  upon  the  one  side  or  the  other. 

Thus  it  must  be  evident,  that  such  a  number  of  paste-boards  are  to  be  provided  and 
mounted  as  equal  the  number  of  throws  of  the  shuttle  between  the  besinning  and  end  of 
any  figure  or  design  which  is  to  be  woven;  the  piercing  of  each  paste-board  individually, 
will  depend  upon  the  arrangement  of  the  lifting  rods,  and  their  connexion  with  the  warp, 


JACQUARD  LOOM. 


1031 


which  is  according  to  the  design  and  option  of  the  workman ;  great  care  must  be  taken 
that  the  holes  come  exactly  opposite  to  the  ends  of  the  needles;  for  this  purpose  two  large 
holes  are  made  at  the  ends  of  the  paste-boards,  which  fall  upon  conical  points,  by  which 
means  they  are  made  to  register  correctly. 

It  will  be  hence  seen,  that,  according  to  the  length  of  the  figure,  so  must  be  the 
number  of  paste-boards,  which  may  be  readily  displaced  so  as  to  remount  and  produce 
the  figure  in  a  few  minutes,  or  remove  it,  or  replace  it,  or  preserve  the  figure  for  future 
use.  The  machine,  of  course,  will  be  understood  to  consist  of  many  sets  of  the  lifting 
rods  and  needles,  shown  in  the  diagram,  as  will  be  perceived  by  observing  the  disposition 
of  the  holes  in  the  paste-board ;  those  holes,  in  order  that  they  may  be  accurately 
distributed,  are  to  be  pierced  from  a  gauge,  so  that  not  the  slightest  variation  shall  take 
place. 

To  form  these  card-slips,  an  ingenious  apparatus  is  employed,  by  which  the  proper  steel 
punches  required  for  the  piercing  of  each  distinct  card,  are  placed  in  their  relative  situa- 
tions preparatory  to  the  operation  of  piercing,  and  also  by  its  means  a  card  may  be  punched 
with  any  number  of  holes  at  one  operation.  This  disposition  of  the  punches  is  effected 
by  means  of  rods  connected  to  cords  disposed  in  a  frame,  in  the  nature  of  a  false  simple, 
on  which  the  pattern  of  the  work  to  be  performed  is  first  read  in. 

These  improved  pierced  cards,  slips,  or  paste-boards,  apply  to  a  weaving  apparatus, 
which  is  so  arranged  that  a  figure  to  be  wrought  can  be  extended  to  any  distance  along 
the  loom,  and  by  that  means  the  loom  is  rendered  capable  of  producing  broad  figured 
works ;  having  the  long  lever  g  placed  in  such  a  situation  that  it  affords  power  to  the 
foot  of  the  weaver,  and  by  this  means  enables  him  to  draw  the  heaviest  morintures  and 
figured  works,  without  the  assistance  of  a  draw-boy. 

The  machinery  for  arranging  the  punches,  consists  of  a  frame  with  four  upright 
standards  and  cross-pieces,  which  contains  a  series  of  endless  cords  passing  under  a 
wooden  roller  at  bottom,  and  over  pulleys  at  the  top.    These  pulleys  are  mounted  on 
axles  in  two  frames,  placed  obliquely  over  the  top  of  the  standard  frame,  wnich  pulley 
frames  constitute  the  table  commonly  used  by  weavers. 

In  order  belter  to  explain  these  endless  cords,  ^g.  784  represents  a  single  endlest 
cord  1,  1,  which  is  here  shown  in  operation,  and  part  of  another  endless  cord  2,  2,  shown 

stationary.  There  must  be  as  many  endless  corda 
in  this  frame  as  needles  in  the  weaving-loom,  a  'a 
the  wooden  cylinder,  revolving  upon  its  axis  at  the 
lower  part  of  the  standards ;  66,  the  two  pulleys  of  the 
pulley-frames  above,  over  which  the  individual  end- 
less cord  passes ;  c  is  a  small  traverse  ring.  To  each 
of  these  rings  a  weight  is  suspended  by  a  single  thread, 
for  the  purpose  of  giving  tension  to  the  endless  cord, 
d  is  a  board  resembling  a  common  comber-bar,  which 
is  supported  by  the  cross-bars  of  the  standard  frame, 
and  is  pierced  with  holes,  in  situation  ani  number, 
corresponding  with  the  perpendicular  threads  that 
pass  through  them ;  which  board  keeps  the  threads 
distinct  from  each  other. 

At  €,  the  endless  cord  passes  through  the  eyes  of 
wires  resembling  needles,  which  are  contained  in  a 
wooden  box  placed  in  front  of  the  machine,  and  shown 
in  this  figure  in  section  only.  These  wires  are  called 
the  punch-projectors ;  they  are  guided  and  supported 
by  horizontal  rods  and  vertical  pins,  the  latter  of 
which  pass  through  loops  formed  at  the  hinder  part 
of  the  respective  wires.  At  /  are  two  horizontal 
rods  extending  the  whole  width  of  the  machine,  for 
the  purpose  of  producing  the  cross  in  the  cords ;  g 
is  a  thick  brass  plate,  extending  along  in  front  of  the 

machine,  and  lying  close  to  the  box  which  holds  the 

punch-projectors ;  this  plate  g,  shown  also  in  section,  is  called  the  punch-holder ;  it  contains 
the  same  number  of  apertures  as  there  are  punch-projectors,  and  disposed  so  as  to  corres- 
pond with  each  other.  In  each  of  these  apertures,  there  is  a  punch  for  the  purpose  of 
piercing  the  cards,  slips,  or  pasteboards  with  holes;  h  is  a  thick  steel  plate  of  the  same 
size  as  g,  and  shown  likewise  in  section,  corresponding  also  m  its  number  of  apertures, 
and  their  disposition,  with  the  punch-projectors  and  the  punch-holder.  This  plate  A,  is 
called  the  punch-receiver. 

The  object  of  this  machine  is  to  transfer  such  of  the  punches  as  may  be  required  for 
piercing  any  individual  card  from  the  punch-holder  g,  into  the  punch-receiver  h ;  when 
Ihey  will  be  properly  situated,  and  ready  for  piercing  the  individual  card  or  slip,  with 


1032 


ICE-HOUSE. 


I 


such  holes  as  have  heen  read  in  upon  the  machine,  and  are  required  for  permitting  the 
warp  threads  to  be  withdrawn  in  the  loom,  when  this  card  is  brought  against  the  ends 
of  the  needles.  The  process  of  transferring  the  patterns  to  the  punches  will  be  effected 
in  the  following  manner. 

The  pattern  is  to  be  read  in,  according  to  the  ordinary  mode,  as  in  a  false  simple, 
upon  the  endless  cords  below  the  rods/,  and  passed  under  the  revolving  wooden  cylinder 
a,  to  a  sufficient  height  for  a  person  in  front  of  the  machine  to  reach  conveniently.  He 
there  takes  the  upper  threads  of  the  pattern,  called  the  beard,  and  draws  them  forward 
so  as  to  introduce  a  stick  behind  the  cords  thus  advanced,  as  shown  by  dots,  for  the  pur- 
pose of  keeping  them  separate  from  the  cords  which  are  not  intended  to  be  operated 
upon.  All  the  punch-projectors  which  are  connected  with  the  cords  brought  forward, 
will  be  thus  made  to  pass  through  the  corresponding  apertures  of  the  punch-holder  g, 
and  by  this  means  will  project  the  punches  out  of  these  apertures,  into  corresponding 
apertures  of  the  punch-receiver  h.  The  punches  will  now  be  properly  arranged  for 
piercing  the  required  holes  on  a  card  or  slip,  which  is  to  be  effected  in  the  following 
manner. 

Remove  the  punch-receivers  from  the  front  of  the  machine ;  and  having  placed  one 
of  the  slips  of  card  or  pasteboard  between  the  two  folding  plates  of  metal,  completely 
pierced  with  holes  corresponding  to  the  needles  of  the  loom,  lay  the  punch-receiver  upon 
those  perforated  plates ;  to  which  it  must  be  made  to  fit  by  mortises  and  blocks,  the 
cutting  parts  of  the  punches  being  downwards.  Upon  the  back  of  the  punch-receiver 
is  then  to  be  placed  a  plate  or  block,  studded  with  perpendicular  pins  corresponding  to 
the  above  described  holes,  into  which  the  pins  will  fall.  The  plates  and  the  blocks  thus 
laid  together,  are  to  be  placed  under  a  press,  by  which  means  the  pins  of  the  block  will 
be  made  to  pass  through  the  apertures  of  the  punch-receiver ;  and  wherever  the  punch 
has  been  deposited  in  the  receiver  by  the  above  process,  the  said  punches  will  be  forced 
through  the  slip  of  pasteboard,  and  pierced  with  such  holes  as  are  required  for  producing 
the  figured  design  in  the  loom. 

Each  card  being  thus  pierced,  the  punch  receiver  is  returned  to  its  place  in  front  of 
the  machine,  and  all  the  punches  forced  back  again  into  the  apertures  of  tl  ?  punch 
holder  as  at  first.  The  next  set  of  cords  is  nove  drawn  forward  by  the  next  beard,  at 
above  described,  which  sends  out  Ihe  pu7ich-projeciors  as  before,  and  disposes  tht^punchev 
in  the  punch-receiver,  ready  for  the  operation  of  piercing  the  next  card.  The  process 
being  thus  repeated,  the  whole  pattern  is,  by  a  number  of  operations,  transferred  to  the 
punches,  and  afterwards  to  the  cards  or  slips,  as  above  described. 

JADE,  axe-stone  (Nephrite,  Ceraunile,  Yr.),  is  a  mineral  co«nmonly  of  a  greenish 
color,  compact,  and  of  a  fatty  lustre.  Spec.  Grav.  2-95  ;  scratches  glass,  is  very  tough  ; 
fuses  into  a  white  enamel.  Its  constituents  are,  silica,  50-5 ;  alumina,  10;  magnesia,  iSl ; 
oxyde  of  iron,  5-50 ;  oxj  de  of  chrome,  0*05 ;  water,  2-75.  It  comes  from  China,  is  used 
among  rude  nations  for  making  hatchets;  and  is  susceptible  of  being  cut  into  any 
form. 

JAPANNING,  is  a  kind  of  varnishing  or  lackering,  practised  with  excellence  by  the 
Japanese,  whence  the  name.     See  Varnish. 

JASPER  (Jaspe  calcedoine,  Fr. ;  Jaspis,  Germ.)  is  a  sub  species  of  calcedt>ny  quartz, 
of  which  there  are  five  varieties.  1.  The  Egyptian  red  and  brown,  with  ring  or  tendril- 
shaped  delineations.  2.  Striped  jasper.  3.  Porcelain  jasper.  4.  Common  jasper.  5. 
Agate  jasper.  The  prettiest  specimens  are  cut  for  seals,  and  for  the  init/V)r  kinds  of 
jewellery  ornaments.     See  Lapidary. 

ICE-HOUSE  ;  (Glaciere,  Fr. ;  Eishaus,  Germ.)  Under  the  article  Freezing  I  have 
enumerated  the  different  artificial  methods  of  producing  cold.  But  for  the  uses  of  com- 
mon life,  in  these  climates,  the  most  economical  and  convenient  means  of  refrigeration  in 
hot  weather  may  be  procured  by  laying  up  a  store  of  ice  in  winter,  in  such  circumstances 
as  will  preserve  it  solid  during  summer. 

An  ice-house  should  not  be  regarded  as  an  object  of  mere  luxury,  for  pleasing  the  pal- 
ates of  gourmands  with  iced  creams  and  orgeats.  In  the  southern  countries  of  Europe 
it  is  considered  among  people  in  easy  circumstances  as  an  indispensable  appendage  to  a 
country  mansion.  During  the  Dog-days,  especially  at  those  periods  and  in  those  dis- 
tricts where  the  sirocco  blows,  a  lassitude  and  torpor  of  mind  and  body  supei-vene,  with 
indigestion  or  total  loss  of  appetite,  and  sometimes  dysenteries,  :;  :.ich  are  obviously  oc- 
casioned  by  the  excessive  heat,  and  are  to  be  prevented  or  countei acted  chiefly  by  the  us€ 
of  cold  beveraqes.  By  giving  tone  to  the  stomach,  iced  drinks  immediately  restore  the 
functions  of  the  nervous  and  muscular  systems  when  they  are  languid  ;  while  they  enable 
persons  in  health  to  endure  without  much  inconvenience  an  atmosphere  so  close  and 
sultry  as  would  be  intolerable  without  this  remedy.  Ice-houses,  moreover,  afford  to 
country  gentlemen  a  great  advantage  in  enabling  them  to  preserve  their  fish,  butcher 
meat,  dead  poultry,  and  game,  which  would  otherwise,  in  particular  states  of  the  weather, 
immediately  spoil.     Considering  at  how  little  expense  and  trouble  an  ice-house  can  b< 


ICE  PRODUCING  MACHINE. 


1033 


constructed,  it  is  surprising  that  any  respectable  haoitation  m  the  country  should  not  have 
one  attached  to  it.  The  simplest  and  most  scientific  form  is  a  double  cone,  that  is,  two 
cones  joined  base  to  base ;  the  one  being  of  stones  or  brickwork,  sunk  under  ground  with 
its  apex  at  the  bottom,  into  which  the  ice  is  rammed ;  the  other  being  a  conical  roof  of 
carpentry  covered  with  thatch,  and  pointed  at  top.  The  entrance  should  be  placed  always 
on  the  north  side ;  it  should  consist  of  a  corridor  or  porch  with  double  doors,  and  be 
screened  from  the  sunbeams  by  a  sm?-ll  shrubbery.  Such  are,  in  general,  the  principles 
upon  which  an  ice-house  should  be  formed ;  but  they  will  be  better  understood  by  the 
following  explanation  and  figure. 

A  dry  sandy  soil  should  be  selected,  and,  if  possible,  a  spot  sheltered  by  a  cliff  or  other 
natural  barrier  from  the  direct  rays  of  the  sun.  Here  a  cavity  is  to  be  dug  about  16  feet 
in  diameter,  terminating  below  like  the  point  of  a  sugar  loaf.  Its  ordinary  depth,  for 
a  moderate  family,  may  be  about  24  feet ;  but  the  larger  its  dimensions  are,  the  longer 
will  it  preserve  the  ice,  provided  it  be  filled.  In  digging,  the  workman  should  slope  the 
ground  progressively  towards  the  axis  of  the  cone,  to  prevent  the  earth  falling  in.  This 
conical  slope  should  be  faced  with  brick  or  stone  work  about  one  foot  thick,  and  jointed 
with  Roman  cement  so  as  to  be  air  and  water  tight.  A  well  is  to  be  excavated  at  the 
bottom  two  feet  wide  and  four  deep,  covered  at  top  with  an  iron  grating  for  supporting 
the  ice,  and  letting  the  water  drain  away. 

The  upper  cone  may  likewise  be  built  of  brickwork,  and  covered  with  thatch ;  such  a 
roof  would  prove  the  most  durable.  This  is  the  construction  shown  in  Jig.  785.  What 
ever  kind  of  roof  be  preferred,  there  must  be  left  in  it  an  oblong  passage  into  the  interior. 
This  porch  should  face  the  north,  and  be  at  least  8  feet  long  by  2^  feet  wide ;  and  per- 
fectly closed  by  a  well-fitted  door  at  each  end.  All  round  the  bottom  of  this  conical 
cover,  a  gutter  should  be  placed  to  carry  off  the  rain  to  a  distance  from  the  ice-house,  and 
prevent  the  circumjacent  ground  from  getting  soaked  with  moisture. 

Fig.  785  shows  the  section  of  a  well-constructed  ice-house.      Under  the  ice-t,ham- 
ber  A  the  ice  is  rammed  into  the  space  b.     c  is  the  grate  of  ths  drain-sink  d.    Tht 
portion  e  e  is  built  in  brick  or  stone ;  the  base  l  of  the  ice-chamber  slopes  inwards  to 
wards  the  ce^re  at  c.      The  upper  part  of  the  brickwork  e  £  is  a  little  way  below  tne 

level  of  the  ground.  The  wooden  frame  work 
F  F  F  F  forms  the  roof,  and  is  covered  with  thick 
thatch.  G  H  is  the  wooden  work  of  the  door  i.  Al 
K  the  bucket  is  seen  for  lifting  up  a  charge  of  ice, 
by  means  of  the  cord  J  passing  over  the  pulley  m, 
which  enables  the  servant  to  raise  it  easily. 

The  icehouse  should  have  no  window  to  admit 
light;  but  be,  so  to  speak,  hermetically  sealed  in 
every  point,  except  at  its  cess-pool,  which  ma) 
terminate  in  a  water  trap  to  prevent  circulation  of 
air. 

A  clear  day  should  be  selected  for  charging  the 
icehouse;  but  before  beginning  to  fill,  a  quantity 
of  long  dry  straw  should  be  laid  on  the  bottom 
crosswise;  and  as  the  ice  is  progressively  introduced, 
straw  is  to  be  spread  against  the  conical  sides,  to  pre- 
vent the  ice  from  coming  into  contact  with  the  brick 
or  stone  work.  The  more  firmly  compacted  the  ict 
is,  the  better  does  it  keep ;  with  which  view  it  should 
be  broken  into  pieces  with  mallets  before  being 
thrown  in.  No  layers  of  straw  should  be  stratified 
among  the  ice,  for  they  would  make  its  body  porous. 
Some  persons  recommend  to  pour  in  a  little  water 
with  the  successive  layers  of  ice,  in  order  to  fill  up  its  small  crevices,  and  convert  the 
whole  into  one  mass. 

Over  the  top  layer  a  thick  bed  of  straw  should  be  spread,  which  is  to  be  covered 
with  boards  surmounted  with  heavy  stones,  to  close  up  the  interstices  in  the  straw.  The 
inner  and  outer  doors  should  never  be  opened  at  once ;  but  the  one  should  always  be  shut 
before  the  other  is  opened. 

Dry  snow  well  rammed  keeps  equally  well  with  hard  ice,  if  cpre  be  taken  to  leave  no 
cavities  in  the  mass,  and  to  secure  its  compactness  by  sprinkling  a  little  water  upon  the 
successive  charges. 

To  facilitate  the  extraction  of  the  ice,  a  ladder  is  set  up  against  its  sloping  wall  at  one 
side  of  the  door,  and  left  there  during  the  season. 

ICE  PRODUCING  MACHINE.  "It  is  well  known  that  by  the  rapid  condensation 
jt  air  or  other  elastic  fluid,  5«>  much  heat  may  be  evolved  as  to  ignite  tinder,  «fcc.  It  appears 
from  a  comiuunicatiun  in   the  Mechanics'  Magazine  of  February,  1851,  that  Dr.  Gi»rrie 


1034 


ILLUMINATION,  COST  OF. 


a  pliysician  iu  New  Orleans,  has  on  this  principle  constructed  an  apparatus  for  producing 
so  much  cold  as  to  freeze  water,  by  exposure  to  the  condensed  air  in  the  act  of  its 
subsequent  expansion.  Gay  Lussac,  many  years  ago,  made  use  of  a  jet  of  condensed  air 
to  refrigerate  any  body  such  as  a  glass  globe  filled  with  water,  upon  which  tlie  ex- 
panding air  was  allowed  to  play,  and  he  even  caused  water  contained  in  the  globe  to 
freeze.  Now  the  American  process  is  quite  identical  with  that  of  the  Frencli  chemist, 
but  on  a  vastly  enlarged  scale,  for  he  employs  the  power  of  a  steam  engine  acting  on  a 
pump  8  inches  in  diameter,  with  a  16  inches  stroke,  to  condense  the  air  into  one  third 
Its  volume,  into  a  vessel,  where  it  is  cooled  by  water.  A  pump  is  made  to  throw  in  a 
jet  of  cold  water  at  the  same  time  to  quicken  the  refrigeration.  It  is  said  that  in  this 
way  a  block  of  ice  of  60  lbs.  was  formed ;  a  circumstance  which  appears  to  me  quite 
incredible.  In  fact,  the  whole  statement  has  a  most  apocryphal  air,  and  I  do  not 
believe  that  any  such  result  could  have  been  produced,  as  the  reporter  says,  by  the 
labour  of  two  men  at  a  couple  of  pumps  in  alternate  action. 

Tlio  inventor's  object  at  first  was  to  ventilate  and  cool  the  atmosphere  of  sick  rooms, 
where  febrile  patients  lay.  **  This  case  is  one  among  the  manv  examples  of  a  useful 
scientific  invention  remaining  long  dormant  or  sterile."  The  hydrostatic  paradox  of 
Archimedes  is  a  parallel  instance,  in  reference  to  Bramah's  press. 

ICE  BY  THE  RED-HOT  PROCESS.  One  of  the  most  singularly  beautiful 
experiments  perhaps  ever  devised,  has  been  recently  published  by  M.  Prevostaire, 
illustrative  of  the  repellent  power  of  heat  radiating  from  bodies  at  a  high  temperature, 
and  of  the  rapid  abstraction  of  heat,  produced  by  evaporation,  or  generally  by  such  a 
change  of  condition  as  largely  increases  the  volume  of  any  body.  The  experiment  is 
simply  this: — A  platina  crucible  is  made  and  maintained  red-hot  over  a  large  spirit 
lamp.  Some  sulphurous  acid  is  poured  into  it  from  a  pipette.  Tliis  acid,  though  at 
common  temperatures  one  of  the  most  volatile  of  known  bodies,  possesses  the  singular 
property  of  remaining  fixed  in  the  red-hot  crucible  and  not  a  drop  of  it  evaporates : 
m  fact,  it  is  not  in  contact  with  the  crucible,  but  has  an  atmosphere  of  its  own  in- 
terposed. A  few  drops  of  common  water  are  now  added  to  the  sulphurous  acid  in  the 
red-hot  crucible.  The  diluted  acid  gets  into  immediate  contact  with  the  >beated  metal, 
instantly  flashes  off  into  sulphurous  acid  vapoiu-,  and  such  is  the  rapidity  and  energy  of 
the  evaporation  that  the  water  remains  behind,  and  is  found  frozen  into  a  lump  of  ice  in 
the  red-hot  crucible,  from  which,  seizing  the  moment  before  it  again  melts,  it  may  be 
thrown  out  before  the  eyes  of  the  astonished  observer. 

JELLY,  VEGETABLE,  of  ripe  currants  and  other  berries,  is  a  compound  of 
mucilage  and  acid,  which  loses  its  power  of  gelatinizing  by  prolonged  ebullition. 

JELLY,  ANIMAL ;  see  Gelatixe,  Glue  and  Isinglass. 

JET  ;  (Jaiet  or  Jaia,  Fr.)  a  species  of  pitch  coal,  or  glance-coal,  which,  being  found 
abundantly  in  a  beautiful  compact  form,  in  the  valley  of  Hers,  arrondissement  of  Pa- 
miers,  department  of  the  Arri^ge,  has  been  worked  up  extensively  there,  from  time  im- 
memorial, into  a  multitude  of  ornamental  articles.  With  this  black  lignate,  buttons, 
crosses, rosaries,  necklaces,  ear-drops,  bracelets,  waist-buckels,  <fec.,  are  made,  which  were 
at  one  time  much  worn  by  ladies  for  mourning  dresses.  The  greater  number  of  these 
ornaments  are  fiishioned  upon  grindstones  which  turn  in  a  horizontal  direction,  and 
are  kept  continually  wet ;  others  are  turned  at  the  lathe,  or  shaped  by  files. 

About  40  years  ago  this  manufacture  employed  from  1000  to  1200  operatives  ;  at 
present  it  gives  bread  to  only  60.  This  falling  off  may  be  ascribed  to  the  successful 
imitation  of  the  jet  articles  b^  those  of  black  glass,  which  are  equally  beautiful,  and  not 
nearly  so  apt  to  lose  their  polish  by  use. 

JET  PUMP.  The  purpose  for  which  this  instrument  is  designed,  is  to  clear  the 
water  out  of  the  pits  of  submerged  water-wheels,  when  access  to  them  is  required  for 
inspection  or  repairs.  For  this  special  purpose  it  is  likely  to  prove  very  useful ;  though 
at  the  same  time,  there  are  very  few  other  cases  in  which  it  could  not  be  employed 
with  advantage.  The  action  of  the  iet  pump  depends  on  two  principles.  One  of 
these  is  the  same  as  that  of  steam  blast  usecl  in  locomotive  engines,  and  in  the  ven- 
tilation of  mines.  The  other  is  one  which  was  known  to  the  ancient  Romans,  and  was 
used  sometimes  by  them  for  drawing  off  more  water  from  the  public  pipes  than  they 
paid  for.  The  jet  pump  was  first  tried  at  the  mill  of  Messrs.  Herdman  «fe  Co.,  Belfast, 
when  it  was  found  most  successful. 

ILLUMINATION,  COST  OF.  The  production,  diffusion,  and  economy  of  light, 
are  subjects  of  the  highest  interest  both  to  men  of  science  and  men  of  "the  world ; 
leading  the  former  to  contemplate  many  of  the  most  beautiful  phenomena  of  Physics' 
and  Chemistry,  while  they  provide  the  latter  with  the  artificial  illumination  so  indis- 
pensable to  the  business  and  pleasures  of  modem  society.  Tlie  great  cost  of  light  from 
wax,  spermaceti,  and  even  stearic  candles,  as  also  the  nuisance  of  the  light  from  tallow 
ones,  have  led  to  the  invention  of  an  endless  variety  of  lamps,  of  which  the  best  hitherto 
known  is  undoubtedly  the  mechanical  or  Carcel  lamp,  so  generally  used  bv  the  opulent 


ILLUMINATION,  COST  OF. 


1035 


families  in  Paris.  In  this  lamp  the  oil  is  raised  through  tubes  by  clock-work,  so  as 
continually  to  overflow  at  the  bottom  of  the  burning  wick ;  thus  keeping  it  thoroughly 
soaked,  while  the  excess  of  the  oil  drops  back  into  the  cistern  below.  I  have  possessed 
for  several  years  an  excellent  lamp  of  this  description,  which  performs  most  satisfactorily; 
but  it  can  hardly  be  trusted  in  the  hands  of  a  servant ;  and  when  it  gets  at  all  deranged, 
it  must  be  sent  to  its  constructor  in  Paris  to  be  repaired.  The  light  of  this  lamp,  when 
furnished  with  an  appropriate  tall  glass  chimney,  is  veiy  brilliant,  though  not  perfectly 
uniform  ;  since  it  fluctuates  a  little,  but  always  perceptibly  to  a  nice  observer,  with  the 
alternating  action  of. the  pump-work;  becoming  dimmer  after  every  successive  jet  of 
oil,  and  brighter  just  before  its  return.  The  flame,  moreover,  always  flickers  more  or 
less,  owing  to  the  powerful  draught,  and  rectangular  reverberatory  shoulder  of  the 
chimney.  The  mechanical  lamp  is,  however,  remarkable  for  continuing  to  burn,  not 
only  with  unabated  but  with  increasing  splendour  for  seven  or  eight  hours ;  the  vivacity 
of  the  combustion  increasing  evidently  with  the  increased  temperature  and  fluency  of 
the  oil,  which,  by  its  ceaseless  circulation  through  the  ignited  wick,  gets  eventually 
pretty  warm.  In  the  comparative  experiments  made  upon  different  lights  by  the 
Parisian  philosophers,  the  mechanical  lamp  is  commonly  taken  as  the  standard.  I  do 
not  think  it  entitled  to  this  pre-eminence :  for  it  may  be  made  to  emit  very  different 
quantities  of  light,  according  to  differences  in  the  nature  and  supply  of  the  oil,  as  well  as 
variations  in  the  form  and  position  of  the  chimney.  Besides,  such  lamps  are  too  rare  in 
this  country  to  be  selected  as  standards  of  illumination. 

.UTter  comparing  lights  of  many  kinds,  I  find  every  reason  to  conclude  that  a  large 
wax  candle  of  three  to  the  pound,  either  long  or  short,  that  is,  either  12  or  15  inches 
in  length,  as  manufactured  by  one  of  the  great  wax-chandlers  of  London,  and  furnished 
with  a  wick  containing  27  or  28  threads  of  the  best  Turkey  cotton,  is  capable  of  fur- 
nishing a  most  uniform,  or  nearly  invariable  standard  of  illumination.  Its  affords  one 
tenth  of  the  light  emitted  by  one  of  the  Argand  lamps  of  the  Trinity  house,  and  one 
eleventh  of  the  light  of  my  mechanical  lamp,  when  each  lamp  is  made  to  burn  with  its 
maximum  flame,  short  of  smoking. 

The  great  obstacle  to  the  combustion  of  lamps,  lies  in  the  viscidity,  and  consequent 
sluggish  supply  of  oil,  to  the  wicks  ;  an  obstacle  nearly  insuperable  with  lamps  of  the 
common  construction  during  the  winter  months.  The  relative  viscidity,  or  relative 
fluency  of  different  liquids  at  the  same  temperature,  and  of  the  same  liquid  at  different 
temperatures,  has  not,  I  believe,  been  hitherto  made  the  subject  ol  accurate  researches. 
I  was,  therefore,  induced  to  make  the  following  experiments  with  this  view. 

Into  a  hemispherical  cup  of  platinum,  resting  on  the  ring  of  a  chemical  stand,  I 
introduced  2,000  water-grain  measures  of  the  liquid  whose  viscidity  was  to  be  measured, 
and  ran  it  off  through  a  glass  syphon,  |  of  an  inch  in  the  bore,  having  the  outer  leg  3  J 
inches,  and  the  inner  leg  3  inches  long.  The  time  of  efflux  became  the  measure  of  the 
viscidity;  and  of  two  liquids,  if  the  specific  gravity,  and  consequent  pressure  upon  the 
syphon,  were  the  same,  that  time  would  indicate  exactly  the  relative  viscidity  of  the  two 
liquids.  Thus,  oil  of  turpentine  and  sperm  oil  have  each  very  nearly  the  same  density ; 
the  former  being,  as  sold  in  the  shops,  =0*876,  and  the  latter  from  0-876  to  0-8S0, 
when  pure  and  genuine.  Now  I  found  that  2,000  grain-measures  of  oil  of  turpentine 
ran  off  through  the  small  syphon  in  95  seconds,  while  that  quantity  of  sperm  oil  took 
2,700  seconds,  being  in  the  ratio  of  1  to  281 ;  so  that  the  fluency  of  oil  of  turpentine  is 
28|  times  greater  than  that  of  sperm  oil.  Pyroxilic  spirit,  conmionly  called  naphtha, 
and  alcohol,  each  of  specific  gravity  0*825,  were  found  to  run  off  respectively  in  80  and 
120  seconds;  showing  that  the  former  was  50  per  cent,  more  fluent  than  the  latter. 
Sperm  oil,  when  heated  to  265  Fahr.,  runs  off  in  300  seconds,  or  one  ninth  of  the  time 
it  took  when  at  the  temperature  of  64P.  Southern  whale  oil,  having  a  greater  density 
than  the  sperm  oil,  would  flow  off  faster  were  it  not  more  viscid. 

2,000  grain-measures  of  water  at  60^  run  off  through  the  said  syphon  in  75  seconds, 
but  when  heated  to  180^,  they  run  off  in  61. 

Concentrated  sulphuric  acid,  though  possessing  the  great  density  of  1*840,  yet  flows 
off  very  slowly  at  64**,  on  account  of  its  viscidity ;  whence  its  name  of  oil  of  vitriol. 
2,000  grain-measures  of  it  took  660  seconds  to  discharge. 

Mr.  Samuel  Parker,  long  advantageously  known  to  the  public  for  his  sinumbral  and 
pneumatic  fountain  lamps,  as  well  as  other  inventions  subservient  to  domestic  comfort, 
having  obtained  a  patent  for  a  new  lamp,  in  which  the  oil  is  heated  by  a  very  simple 
contrivance,  in  the  cistern,  to  any  desired  degree,  before  arriving  at  the  wick,  I  insti- 
tuted an  extensive  series  of  experiments  to  determine  its  value  in  the  production  of 
light,  and  consumption  of  oil,  compared  to  the  value  of  other  lamps,  as  well  as  candles, 
in  these  respects. 

In  fig.  786,  A,  A,  B,  B,  is  a  section  of  the  cylinder  which  constitutes  the  cistern; 
the  oil  being  contained  between  the  inner  and  outer  cylinders,  and  receiving  heat  from 
the  flame  of  the  lamp  which  passes  up  through  the  inner  cylinder,  and  is  rever- 


i 


1036 


ILLUMINATION,  COST  OF. 


berated  more  or  less  against  its  sides  by  the  top  of  the  metal  chimney,  being  notched 
and  bent  back.  D  is  a  slide-valve  which  is  opened  to  allow  the  oil  to  descend  to  the 
■wick,  and  is  shut  when  the  cistern  is  to  be  separated  from  the  pipe  of  supply,  at  E, 
for  the  purpose  of  recharging  it  with  oil.  The  flame  is  modified,  not  by  raising  or 
lowering  the  wick,  as  in  common  lamps,  but  by  raising  or  lowering  the  bell-mouthed 
glass  chimney  which  rests  at  its  bottom  on  three  points,  and  is  moved  by  means  of  the 
rack-work  mechanism  F.  The  concentric  cylindric  space  A,  A,  and  B,  B,  contains  a 
pint  imperial,  and  should  be  made  entirely  full  before  lighting  the  lamp ;  so  as  to  leave 
no  air  in  the  cistern,  which,  by  its  expansion  with  the  heat,  would  inevitably  cause  an 
overflow  of  the  oil. 

The  following  arrangement  was  adopted  in  these  experiments  for  determining  the 
relative  illumination  of  the  different  lights.  Having  trimmed,  with  every  precaution, 
my  French  mechanical  lamp,  and  charged  it  with  pure  sperm  oil,  I  placed  it  upon  an 
oblong  table,  at  a  distance  of  10  feet  from  a  wall,  on  which  a  white  sheet  of  paper  was 
stuck.  One  of  Mr.  Parker's  hot-oil  lamps,  charged  with  a  quantity  of  the  same  oilj 
wns  placed  upon  the  same  table;  and  each  being  made  to  burn  with  its  maximLJH 


.•  r- .  ■ 


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brilliancy,  short  of  smoking,  the  relative  illumination  of  the  two  lamps  was  determined 
by  the  well-known  method  of  the  comparison  of  shadows ;  a  wire  a  few  inches  long, 
and  of  the  thickness  of  a  crow-quill,  being  found  suitable  for  enabling  the  eye  to  esti- 
mate very  nicely  the  shade  of  the  intercepted  light.  It  was  observed  in  numerous  trials, 
both  by  my  own  eyes  and  those  of  others,  that  when  one  of  the  lamps  was  shifted  half 
an  inch  nearer  to  or  further  from  the  paper  screen,  it  caused  a  perceptible  difference 
In  the  tint  of  the  shadow.  Professor  Wheatstone  kindly  enabled  me  to  verify  the  pre- 
cision of  the  above  method  of  shadows,  by  employing,  in  some  of  the  experiments,  a 
photometer  of  his  own  invention,  in  which  the  relative  brightness  of  the  two  lights  was 
determined  by  the  relative  brightness  of  the  opposite  sides  of  a  revolving  silvered  ball, 
illuminated  by  them. 

1.  The  mechanical  lamp  was  furnished  with  a  glass  chimney  1*5  inches  in  diameter 
at  the  base,  and  1*2  at  top;  the  wide  bottom  part  was  1*8 inches  long,  and  the  narrow 
upper  part  8  inches.  When  placed  at  a  distance  of  10  feet  from  the  wall  its  light  there 
may  be  estimated  as  the  square  of  this  number,  or  100.  In  the  first  series  of  experi- 
ments, when  burning  with  its  maximum  flame,  with  occasioned  flickerings  of  smoke, 
it  emitted  a  light  equal  to  that  of  11  wax  candles,  and  consumed  912  grains  of  oil  per 
hour.     The  sperm  oil  was  quite  pure,  having  a  specific  gravity  of  0-874  compared  to 


ILLUM  [NATION,  COST  OF. 


1037 


water  at  1,000.  In  a  subsequent  series  of  experiments,  when  its  light  was  less  flickering, 
and  equal  only  to  that  of  10  wax  candles,  it  consumed  only  815  grains,  or  0*1164  of  a 
lb.  per  hour.  If  we  multiply  this  number  into  the  price  of  the  oil  (8*.  per  gallon)  per 
lb.  1  Id.,  the  product  l*2804(f.  will  represent  the  relative  cost  of  this  illumination,  esti- 
mated at  100. 

2.  The  hot-oil  lamp  burns  with  a  much  steadier  flame  than  the  mechanical,  which 
must  be  ascribed  in  no  small  degree  to  the  rounded  slope  of  the  bell-mouthed  glass 
chimney,  whereby  the  air  is  brought  progressively  closer  and  closer  into  contact  with 
the  outer  surface  of  the  flame,  without  being  furiously  dashed  against  it,  as  it  is  by  the 
rectangular  shoulder  of  the  common  contracted  chimney.  When  charged  with  sperm 
oil,  and  made  to  burn  with  its  maximum  flam.e,  this  lamp  required  to  be  placed  one 
foot  further  from  the  screen  than  the  mechanical  lamp,  in  order  that  its  shadow  should 
have  the  same  depth  of  tint.  Hence,  its  relative  illumination  was,  in  that  case,  as  the 
■quare  of  11  to  the  square  of  10';  or  as  121  to  100.  Yet  its  consumption  of  oil  was 
only  696  grains,  or  somewhat  less  than  0*1  of  a  pound  per  hour.  Had  its  light  been 
reduced  to  100,  it  would  have  consumed  only  576  grains  per  hour,  or  0-82  of  a  pound. 
If  we  multiply  this  number  by  lid.,  the  product  0*902d.  will  represent  the  relative  cost 
of  100  of  this  illumination. 

3.  The  hot-oil  lamp  being  charged  with  the  southern  whale  oil,  of  specific  gravity 
0'926,  at  25.  Qd.  per  gallon,  or  3Jd.  per  lb.,  when  burning  with  its  maximum  flame, 
required  to  be  placed  9  feet  and  1  inch  from  the  screen  to  drop  the  same  tint  of  shadow 
upon  it  as  the  flames  of  the  other  two  lamps  did  at  10  and  1 1  feet  with  the  sperm  oil. 
The  square  of  9  feet  and  1  inch  =  82  is  the  relative  illumination  of  the  hot-oil  lamp 
with  the  southern  whale  oil.  It  consumed  780  grains,  or  0-  J 1 1  of  a  pound  per  hour ; 
but  had  it  given  100  of  light  it  would  have  consumed  911  grains,  or  0*130  of  a  pound, 
which  number  being  multiplied  by  its  price  3|i.,  the  product  0*4875<f.  will  represent 
the  relative  cost  of  100  of  this  light. 

4.  A  hot-oil  lamp  charged  with  olive  oil  of  specific  gravity  0*914,  at  5*.  6d.  per 
gallon,  or  lyt,  per  lb.  when  burning  with  its  maximum  flame,  required  to  be  placed  at 
9  feet  6  inches,  to  obtain  the  standard  tint  of  shadow  upon  the  screen.  It  consumed 
760  grains  per  hour.  The  square  of  9|  feet  is  90  j,  which  is  the  relative  intensity  of  the 
light  of  this  lamp.  Had  it  emitted  a  light  =  100,  it  would  have  consumed  840  grains, 
or  0*12  of  a  pound  per  hour — which  number  multiplied  by  the  price  per  pound,  gives 
file  product  0-9iZ.  as  the  relative  cost  of  100  of  this  light. 

5.  A  hot-oil  lamp  charged  with  Price  and  Co.'s  cocoa-nut  oil  (oleine),  of  specific 
gravity  0*925,  at  4*.  Qd.  per  gallon,  or  b\d,  per  lb.,  had  to  be  placed  9  feet  from  the 
screen,  and  consumed  1,035  grains  per  hour.  Had  its  light  been  100  instead  of  81  (92), 
the  consumption  would  have  been  1,277  grains,  or  0*182  of  a  pound  per  hour !  which 
number  multiplied  by  its  price  per  pound,  the  product  1*03 Id.  will  represent  the  cost  of 
100  of  this  illumination. 

6.  In  comparing  the  common  French  annular  lamp  in  general  use  with  the  mechani- 
cal lamp,  it  was  found  to  give  about  one  half  the  light,  and  to  consume  two  thirds  of 
the  oil  of  the  mechanical  lamp. 

7.  Wax  candles  from  some  of  the  most  eminent  wax-chandlers  of  the  metropolis 
were  next  subjected  to  experiment ;  and  it  is  very  remarkable  that,  whether  they  were 
threes,  fours,  or  sixes  in  the  pound,  each  afforded  very  nearly  the  same  quantity  of 
light,  for  each  required  to  be  placed  at  a  distance  of  three  feet  from  the  screen  to  afford 
a  shadow  of  the  same  tint  as  that  dropped  from  the  mechanical  lamp,  estimated  at  100. 
The  consumption  of  a  genuine  wax  candle,  in  still  air,  is  upon  an  average  of  many  ex- 
periments, 125  grains  per  hour,  but  as  it  affords  only  1  11th  of  the  light  cf  the 
mechanical  lamp,  11  times  125=  1,375  grains,  or  0*1064  of  a  pound  is  the  quantity 
that  would  need  to  be  consumed  to  produce  a  light  equal  to  that  of  the  said  lamp. 
If  we  multiply  that  number  by  the  price  of  the  candles  per  lb.  =  30d.  the  product 
=  5-892d.  is  the  cost  of  100  of  illumination  by  wax.  A  wax  candle,  three  in  the  pound 
(short),  is  one  inch  in  diameter,  12  inches  in  length,  and  contains  27  or  28  threads, 
each  about  1  10th  of  an  inch  in  diameter.  But  the  quality  of  the  wick  depends  upon  the 
capillarity  of  the  cotton  fibrils,  which  is  said  to  be  greatest  in  the  Turkey  cotton,  and 
hence  the  wicks  for  the  best  wax  candles  are  always  made  with  cotton  yarn  imported 
from  the  Levant.  A  wax  candle,  three  in  the  pound  (long),  is  |  of  an  inch  in  diameter, 
15  inches  long,  and  has  26  threads  in  its  wick.  A  wax  candle,  six  to  the  pound,  is  9 
inches  long,  4  5ths  of  an  inch  in  diameter,  and  has  22  threads  in  its  wick.  The  light  of 
this  candle  may  be  reckoned  to  be,  at  most,  about  1  Uth  less  than  that  of  the  threes  in 
the  pound.  A  well-made  short  three  burns  with  surprising  regularity  in  still  air,  being 
at  the  rate  of  an  inch  in  an  hour  and  a  half,  so  that  the  whole  candle  will  last  18  hours. 
A  long  three  will  last  as  long,  and  a  six  about  9|  hours.  Specific  gravity  of  wax  = 
0-960. 

8.  A  spei*maceti  candle,  three  in  the  pound,  is  9  lOths  of  an  inch  in  diameter,  15 
inches  long,  and  has  a  plaited  wick,  instead  of  the  parallel  threads  of  a  wax  candle.  The 


1038 


ILLUMINATION.  COST  OF. 


same  candles  four  in  the  pound,  are  8  lOths  of  an  inch  in  diameter,  and  13^  inches  long. 
Each  gives  very  nearly  the  same  quantity  of  light  as  the  corresponding  wax  candles : 
viz.,  1  11th  of  the  light  of  the  above  mechanical  lamp,  and  consumes  142  grains  per 
hour.  Multiplying  the  last  number  by  1 1,  the  product,  1,562  grains  =  0-223  of  a  pound, 
would  be  the  consumption  of  spermaceti  requisite  to  give  100  of  illumination.  Multi- 
plying the  last  number  by  24(/.,  the  price  of  the  candles  per  pound,  the  product  5-352^. 
Is  the  relative  cost  of  100  of  this  illumination. 

9.  Stearic  acid  candles,  commonly  called  German  wax,  consume  168*5  grains,  or 
0*024  of  a  pound  per  hour,  when  emitting  the  same  light  as  the  standard  wax  candle. 
Multiplying  the  latter  number  by  11,  and  by  16d.  (the  price  of  the  candles  per  pound), 
the  product  4'224d.  will  represent  the  relative  cost  of  100  of  this  illumination. 

10.  Tallow  candles :  moulds,  short  threes,  1  inch  in  diameter,  and  12^  in  length ;  do. 
loEg  threes,  9  lOths  of  an  inch  in  diameter,  and  15  in  length ;  do.,  long  fours,  8  lOths  of 
an  inch  in  diameter,  and  13|  in  length.  Each  of  these  candles  burns  with  a  most  ub 
certain  light,  which  varies  from  1  12th  to  1  16th  of  the  light  of  the  mechanical  lamp— 
the  average  may  be  taken  at  1  14th.  The  threes  consume  each  144  grains,  or  0-2  of  a 
pound,  per  hour;  which  number,  multiplied  by  14,  and  by  9d.  (the  price  per  pound), 
gives  the  product  2-52d.  for  the  relative  cost  of  100  of  this  illumination. 

11.  Palmer's  spreading  wick  candles.  Distance  from  the  screen  3  feet  4  inches,  with 
a  shadow  equal  lo  the  standard.  Consumption  of  tallow  per  hour  232'5  grains,  or 
0*0332  of  a  pound.  The  square  of  3  feet  4  inches  =  11*9  is  the  relative  illumination 
of  this  candle  =  11-9  :  :  0*3332  : :  100  :  0*28  X  lOd.  =  11*9  is  the  relative  cost  of  this 
illumination. 

12.  Cocoa-nut  stearine  candles  consumed  each  168  grains  per  hour,  and  emitted  a 
light  equal  to  1  16th  of  the  standard  flame.  Multiplying  168  by  16,  the  product  30*88 
grains,  or  0*441  of  a  pound,  is  the  quantity  which  would  be  consumed  per  hour  to  afford 
a  light  equal  to  100.  And  0*441  multiplied  by  lOd.,  the  price  per  pound,  gives  the 
product  4*441rf.  as  the  cost  of  100  of  this  illumination  per  hour. 

A  gas  argand  London  lamp,  of  12  holes  in  a  circle  of  ^  of  an  inch  in  diameter,  with 
a  flame  3  inches  long,  afforded  a  light  =  78|  compared  to  the  mechanical  lamp  :  and 
estimating  the  light  of  the  said  mechanical  lamp  as  before,  at  100,  that  of  the  bot-oil 
lamp  is  121,  and  that  of  the  above  gas  flame  of  78*57,  or  in  round  numbers  80,  and  the 
common  French  lamp  iri  general  use  50. 

Collecting  the  preceding  results,  we  shall  have  the  following  tabular  view  of  the 
cost  per  hour  of  an  illumination  equal  to  that  of  the  mechanical  lamp,  reckoned  100,  or 
that  of  eleven  wax  candles,  three  to  the  pound. 


Table  of  Cost  per  Hour  of  One  Hundred  of  Illumination. 


1. 

2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 


Parker's  hot-oil  lamp,  with  southern  whale  oil 
Mechanical  or  Carcel  lamp,  with  sperm  oil 
Parker's  hot-oil  lamp,  with  sperm  oil 
Ditto  ditto  common  olive  oil 

Ditto  ditto  cocoa-nut  oleine  or  oil 

French  lamp  in  general  use,  with  sperm  oil 
Wax  candles    ------ 

Spermaceti  candles  _        -        -        - 

German  wax  (Stearic  acid)  ditto 
Palmer's  spreading  wick  candles 

11.  Tallow  (mould)  candles  -        -        - 

12.  Cocoa-nut  stearine  of  Price  and  Co. 


Pence. 

Pence 

0*4875 

or 

about    ^d. 

1*2804 

. 

-    li 

0*902 

_ 

-      1 

0*900 

. 

-      1 

1*031 

. 

-     1 

1*7072 

• 

-      If 

5*892 

. 

-    6 

5*352 

- 

-    5i 

4*224 

- 

-    4: 

2*800 

. 

-     2:1 

2*520 

. 

-    2| 

4*41 

- 

-    41 

Since  the  hot-oil  lamp  affords  sufllicient  light  for  reading,  writing,  sewing,  &,c.,  with 
one  fifth  of  its  maximum  flame,  it  will  burn  at  that  rate  for  10  hours  at  the  cost  of 
about  one  penny,  and  it  is  hence  weU  entitled  to  the  inventor's  designation,  "  The 
Economic." 

Sir  D.  Brewster,  in  his  examination  lately  before  the  committee  of  the  house  of 
commons  on  lighting  the  house,  stated,  that  the  French  light-house  lamp  of  Fresnel 
emitted  a  light  equal  to  that  of  forty  argand  flames ;  whereas,  according  to  other 
accounts,  it  gave  much  less  light.  With  the  view  of  settling  this  point,  before  being 
examined  by  the  said  committee,  I  repaired  to  the  Trinity  house,  and  tried  one  of 
the  two  original  Fresnel  lamps,  which  had  been  deposited  there  by  that  eminent  French 
engineer  himself.  This  lamp  consists  of  four  concentric  circular  wicks,  placed  in  one 
horizontal  plane  ;  the  innermost  wick  being  |  of  an  inch  in  diameter,  and  the  outermost 
3|  inches.  Being  carefully  trimmed,  supplied  with  the  best  sperm  oil,  surmounted 
with  its  great  glass  chimney,  burning  with  its  iraximum  flame,  and  placed  at  a  distance 
of  13  feet  3  inches  from  the  screen,  it  let  fall  a  shadow  of  the  same  tiut  as  that  let  fall 


ILLUMINATION,  COST  OP. 


1039 


by  the  flame  of  my  mechanical  lamp,  placed  at  a  distance  of  4  feet  6  inches  from  the 
screen.  The  squares  of  these  two  numbers  are  very  nearly  as  8f  to  1  (175*5625  to 
20*25)  ;  showing  that  the  Fresnel  lamp  gives  less  than  9  times  the  light  of  my  me- 
chanical lamp,  and  about  9*6  times  the  light  of  one  of  the  Trinity  house  argand  lamps. 
The  Fresnel  lamp  is  exceedingly  troublesome  to  manage,  from  the  great  intensity  of  its 
heat,  and  the  frequent  fractures  of  its  chimneys— two  having  been  broken  in  the  course 
of  my  experiments  at  the  Trinity  house. 

Mr.  Goldsworthy  Gum sy,  the  ingenious  inventor  of  the  new  light-house  lamp,  m 
which  a  stream  of  oxygen  gas  is  sent  up  through  a  small  tube  within  the  burning  cir- 
cular wick  of  a  small  argand  lamp,  having  politely  sent  two  of  his  lamps  to  my  house, 
along  with  a  bag  of  oxygen  gas,  I  made  the  following  experiments,  to  ascertain  their 
illuminating  poweis  compared  to  those  of  the  mechanical  lamp  and  wax  candles. 

His  larger  lamp  has  a  wick  f  of  an  inch  in  diameter,  but  emits  an  oxygen  flame  of 
only  %  of  an  inch.  The  flame  is  so  much  whiter  than  that  of  the  best  lamp  or  candlp 
that  It  becomes  difficult  to  determine,  with  ultimate  precision,  the  comparative  depths 
of  the  shadows  let  fall  by  them.  The  mean  of  several  trials  showed  that  the  above 
Bude-light  (as  Mr.  Gurney  calls  it,  from  the  name  of  his  residence  in  Cornwall),  has 
an  illuminating  power  of  from  28  to  30  wax  candles.  His  smaller  lamp  has  a  flame  i 
of  an  inch  in  diameter,  and  a  wick  |  of  an  inch.  Its  light  is  equal  to  that  of  from  18 
to  20  wax  candles. 

The  committee  of  the  house  of  commons  on  lighting  it,  having  asked  me  what  was 
the  relative  vitiation  of  air  by  the  breathing  of  men  and  the  burning  of  candles,  I  gave 

the  following  answer : —  .      on  » 

Wax  contains  81*75  parts  of  carbon  in  100,  which  generate  by  combustion  300  parts 
of  carbonic  acid  gas.  Now,  since  125  grains  of  wax  constitute  the  average  consump- 
tion of  a  candle  per  hour,  these  will  generate  375  grains  of  carbonic  aci J ;  equivalent 
in  volume  to  800  cubic  inches  of  gas.  According  to  the  most  exact  experiments  on 
respiration,  a  man  of  ordinary  size  discharges  from  his  lungs  1,632  cubic  inches  of  car- 
bonic acid  gas  per  hour,  which  is  very  nearly  the  double  of  the  quantity  produced  from 
the  wax  candle.  Hence  the  combustion  of  two  such  candles  vitiates  the  air  much 
the  same  as  the  breathing  of  one  man.  A  tallow  candle,  three  or  four  in  the  pound, 
generates  nearly  the  same  quantity  of  carbonic  acid  as  the  wax  candle ;  for  though  tal- 
low contains  only  79  per  cent,  of  carbon,  instead  of  81.75,  yet  it  consumes  so  much 
faster,  as  thereby  to  compensate  fully  for  this  difference. 

When  a  tallow  candle  of  6  to  the  lb.  is  not  snuffed,  it  loses  in  intensity,  in  30  min- 
utes, 80  hundredths ;  and  in  39  minutes  86  hundredths,  in  which  dim  state  it  remains 
stationary,  yet  still  consuming  nearly  the  same  proportion  of  tallow.  A  wax  candle 
attains  to  its  greatest  intensity  of  light  when  its  wick  has  reached  the  greatest  length, 
and  begins  to  bend  out  of  the  flame.  The  reason  of  this  difference  is,  that  only  the 
lower  part  of  the  wick  in  the  tallow  candle  is  charged  with  the  fat,  so  as  to  emit  lu- 
miniferous  vapor,  while  the  upper  part  remains  dry ;  whereas,  in  the  wax  candle,  the 
combustible  substance  being  less  fusible  and  volatile,  allows  a  greater  length  of  the 
wick  to  be  charged  by  capillary  attraction,  and  of  course  to  emit  a  longer  train  of  light. 
The  following  table  contains,  according  to  Peclet,  the  illuminating  powers  of  differ- 
ent candles,  and  their  consumption  of  material  in  an  hour ;  the  light  emitted  by  a  Car- 
cel argand  lamp,  consuming  42  grammes  (=  42  X  15|  grains)  in  an  hour,  being  called 
100:— 


Tallow  Candles  6  in  lb.  - 

Stearine,  or  Pressed  Tallow,  8  in  lb.    - 

_ ^ 5  in  lb.    - 

Wax  Candles,  5  in  lb.  - 
Spermaceti  ditto,  5  in  lb. 
Stearic   Acid,   commonly   called   Stea- 
rine, 5  in  lb.  - 


Intensity  of  Light. 


10*66 

8*74 

7.50 

13*61 

14*40 

14*40 


Consumption  per  Hour.    I 


8*51 
7*51 
7*42 
8-71 
8-92 

9*33 


The  subjoined  table  shows  the  economical  ratios  of  the  candles,  where  the  second 
column  gives  the  quantity  of  material  in  grammes  which  is  requisite  to  produce  as  much 
light  as  the  Carcel  lamp  *. — 


I 

1 !  ' 
ft  j 


1040 


ILLUMINATION,  COST  OF. 


Tallow  candle,  6  per  lb. 

,  8  per  lb. 

Pressed  tallow,  5  pej  lb.  - 
Wax  candle,  5  per  lb.  -  - 
Spermaceti  ditto,  5  per  lb.  - 
Stearine,  6  per  lb.     ... 


Quality  of 
MateriaL 


70-36 
86-92 
98-93 
6404 
61-94 
66-24 


Price  per  Kilo- 
gramme. 


If. 
If. 
2f 
7f. 
If. 
6f. 


40  c. 
40  c. 
40  c. 
60  c 
60  c. 


Cost  of  Light  per 
Honr. 


9-8  C. 
12-0  C. 
23-7  c. 
48-6  c. 
47-8  c. 
871  c. 


These  results  may  be  compared  with  mine  given  above.  A  kilogramme,  or  1000 
grammes  =  15,440  grains  =  2^^  lbs.  avoirdupois. 

J  INT  A  "WAN.  A  compound,  elastic,  water-repellent  substance  for  manufacturing  pur- 
poses is  made  by  combinmg  gutta  percha  with  an  elastic  and  water-repellent  substance 
called  "  jinta-wan,"  recently  imported  for  the  first  time  from  the  East  Indies,  and  which 
has  never  heretofore,  to  the  best  of  my  knowledge  and  belief,  been  used  in  the  arts  and 
manufactures  of  this  country;  or  by  combining  gutta  percha  with  "jinta-wan"  and 
caoutchouc.  The  gutta  percha  which  is  intended  to  be  combined  in  this  way  should, 
if  necessary,  be  cleansed  from  impurities,  and  may  if  desired  be  previously  prepared  as 
heretofore  described.  The  jinta-wan,  or  caoutchouc,  should  also  be  cleansed  from  its 
impurities,  if  any.  Gutta  percha  and  jinta-wan  are  combined  by  placing  these  two 
substances  in  the  intended  proportions  (cut  into  pieces)  in  a  masticator,  such  as  is 
used  for  masticating  caoutchouc,  and  then  operate  upon  the  two  materials  by  that 
machine  until  they  are  intimately  blended  together.  And  the  triple  combination 
of  gutta  percha,  jinta-wan,  and  caoutchouc  are  combined  by  means  of  a  masticator,  in 
the  same  manner.  For  the  purpose  of  making  these '  combinations,  the  propor- 
tions of  the  two,  or  of  the  three  substances  may  be  combined  according  to  tlie  quality 
which  it  is  desired  that  the  combined  substance  shall  possess,  employing  a  larger  pn>- 
portion  of  any  one  of  the  substances  to  be  combined,  when  it  is  desired  that  the  pecu- 
liar qualities  of  that  substance  shall  predominate  in  the  combined  article.  See  Gutta 
Percha. 

IMPERMEABLE,  is  the  epithet  given  to  any  kind  of  textile  fabric,  rendered  water- 
proof by  one  or  other  of  the  following  substances : — 

1.  Linseed  oil  to  which  a  drying  quality  has  been  communicated  by  boiling  with 
litharge  or  sugar  of  lead,  <fec. 

2.  The  same  oil  holding  in  solution  a  little  caoutchouc. 

3.  A  varnish  made  by  dissolving  caoutchouc  in  rectified  petroleum  or  naphtha,  applied 
between  two  surfaces  of  cloth,  as  described  under  Macintosh's  patent.  See  Caout- 
cuouc. 

4.  Vegetable  or  mineral  pitch,  applied  hot  with  a  brush,  as  in  making  tarpauling  for 
covering  goods  in  ships. 

5.  A  solution  of  soap  worked  into  cloth,  and  decomposed  in  it  by  the  action  of  a 
solution  of  alum  ;  whence  results  a  mixture  of  acid  fats  and  alumina,  which  insinuates 
itself  among  all  the  woolly  filaments,  fills  their  interstices,  and  prevents  the  passage  of 

6.  A  solution  of  glue  or  isinglass,  introduced  into  a  stuff,  and  then  acted  upon  by  a 
clear  infusion  of  galls,  whereby  the  fibres  get  impregnated  with  an  insoluble,  impermea- 
ble, pulverulent  leather. 

7.  Plaster  work  is  rendered  impermeable  by  mixing  artificial  or  natural  asphaltura 
with  it. 

JEWELLERY,  ^r^o/     See  Gem  and  Lapidary. 

INCOMBUSTIBLE  CLOTH  ;  is  a  tissue  of  the  fibrous  mineral  called  amianthus  or 
asbestos.  This  is  too  rare  to  form  the  object  of  any  considerable  manufacture.  Cotton 
and  linen  cloth  may  be  best  rendered  incapable  of  taking  fire,  or  burning  with  flame,  by 
beinfj:  imbued  with  a  sohition  of  sal  ammoniac. 

INCUBATION,  ARTIFICIAL.  The  Egyptians  have  from  time  immemorial 
been  accustomed  to  hatch  eggs  by  artificial  warmth,  without  the  aid  of  hens,  in  peculiar 
t^toves,  called  Mammals.  The  inhabitants  of  the  village  Berme  still  travel  through  the  most 
distant  provinces  of  Ei^ypt  at  certain  seasons  of  the  year,  with  a  portable  furnace,  heated 
by  a  lamp,  and  either  hatch  chickens  for  sale,  or  undertake  to  hatch  the  eggs  belongino- 
to  the  natives  at  a  certain  rate  per  dozen.  M.  de  Reaumur  published  in  France  abou*t 
a  century  ago,  some  ingenious  observations  upon  this  subject ;  but  M.  Bonnt;main  was 
the  first  person  who  studied  with  due  attention  all  the  circumstances  of  artificial  incu- 
bation, and  mounted  the  process  successfully  upon  the  commercial  scale.  So  far  back  as 
1777  he  communicated  to  the  Academy  of  Sciences  an  interesting  fact,  which  he  had 


INCUBATION,  ARTIFICIAL. 


1041 


noticed,  upon  the  mechanism  employed  by  chicks  to  break  their  shells ;  and  for  some 
time  prior  to  the  French  revolution  he  furnished  the  Parisian  market  with  excellent 
poultry  at  a  period  of  the  year  when  the  farmers  had  ceased  to  supply  it.  His  estab- 
lishment was  ruined  at  that  disastrous  era,  and  no  other  has  ever  since  been  constructed 
or  conducted  with  similar  care.  As  there  can  be  no  doubt  however  of  the  practicability 
and  profitableness  of  the  scheme,  when  judiciously  managed,  I  shall  insert  a  brief 
account  of  his  ingenious  arrangements.  I  had  the  pleasine  of  making  the  acquaintance 
of  this  amiable  old  man  at  my  first  visit  to  Paris,  many  years  ago,  and  believe  all  his 
statements  to  be  worthy  of  credit.  Some  imitations  of  his  plans  have  been  made  in  tliis 
country,  but  how  far  they  have  succeeded  in  an  economical  point  of  view,  it  is  difficult 
to  determine.  His  apparatus  derives  peculiar  interest  from  the  fact,  that  it  was  founded 
upon  the  principle  of  the  circulation  of  hot  water,  by  the  intestine  motion  of  its  particles, 
in  a  returning  series  of  connected  pipes ;  a  subject  afterwards  illustrated  in  the  experi- 
mental researches  of  Count  Rumford.  It  has  of  late  years  been  introduced  as  a  novelty  into 
iliis  country,  and  applied  to  warm  the  apartments  of  many  public  and  private  buildings. 
The  following  details  will  prove  that  the  theory  and  practice  of  hot-water  circulation 
were  as  perfectly  understood  by  M.  Bonnemain  fifty  years  ago,  as  they  are  by  any  of 
our  stove  doctors  at  the  present  day.  They  were  tlien  publicly  exhibited  at  his  resi- 
dence in  Paris,  and  were  afterwards  communicated  to  the  world  at  large  in  the  interest- 
ing article  of  the  Dictionnaire  Technologique,  entitled  Jncrcbation  Artijiciclle. 

The  apparatus  of  M.  Bonnemain  consisted;  1.  of  a  boiler,  and  pipes  for  the  circu- 
lation of  water ;  2.  of  a  regulator  calculated  to  maintain  an  equable  temperature ;  3. 
of  a  stove-apartment,  heated  constantly  to  the  degree  best  fitted  for  incubation,  which 
he  called  the  hatching  pitch.  He  attached  to  one  side  a  pousabdere  or  chick-room,  for 
cherishing  the  chickens  during  a  few  days  after  incubation. 

Tlie  boiler  is  represented  in  vertical  section  and  ground  plan,  in  Jigs.  787  and  788. 
It  is  composed  of  a  double  cylinder  of  copper  or  cast  iron  I,  I,  having  a  grate  6  (see 
,.(j^  plan),  an  ash-pit  at  d  (section).     The  water  occupies  the  shaded 

—  space  c,  c,  h,  g,  g,  e,  e,  are  five  vertical  flues,  for  conducting 
Dthe  burnt  air  and  smoke,  which  first  rise  in  the  two  exterior 
flues  e,  e,  then  descend  in  the  two  adjoining  flues  g,  g,  and 
finally  re-mount  through  the  passages  ?,  i,  in  the  central  flue 
h.  During  this  upwards  and  downwards  circulation,  as  shown 
by  the  arrows  in  the  section,  the  products  of  combustion  are 
made  to  impart  nearly  the  whole  of  their  heat  to  the  water  by 
which  they  are  surrounded.  At  the  commencement  some 
burning  paper  or  wood  shavings  are  inserted  at  the  orifice  »*, 
to  establish  a  draught  in  this  circuitous  chimney.  The  air  is 
^:|?  admitted  into  the  ash-pit  at  the  side,  in  regulated  quantities, 
through  a  small,  square  door,  moveable  round  a  rod  which  runs 
horizontally  along  its  middle  line.  This  swing  valve  is  acted 
upon  by  an  expanding  har  (see  Heat-Regulator),  which 
opens  it  more  or  less  according  to  the  temperature  of  the 
stove  apartment  in  which  the  eggs  are  placed. 
D  is  the  upper  orifice  of  the  boiler,  by  which  the  hotter  and  consequently  lighter  par- 
ticles of  the  water  continually  ascend,  and  are  replaced  by  the  cooled  particles,  which 
enter  the  boiler  near  its  bottom,  as  shown  hi  Jig.  789.  at  r.  Into  further  details  relative 
to  the  boiler  it  is  needless  to  enter ;  for  though  its  form,  as  designed  by  M.  Bonnemain, 
is  excellent  and  most  economical  of  heat  for  a  charcoal  fire,  it  would  not  suit  one  of 
pit-coal,  on  account  of  the  obstruction  to  the  pipes  which  would  soon  be  occasioned  by 
its  soot. 

In  Jig.  789.  the  boiler  is  shown  at  r,  with  the  rod  which  regulates  the  air  door  of  the 
ash-pit.  D  is  a  stopcock  for  modifying  the  opening  by  which  the  hotter  particles  of 
water  ascend  ;  g  is  the  water-pipe  of  communication,  having  the  heating  pipe  of  distri- 
bution attached  between  e  f,  which  thence  passes  backwards  and  forwards  with  a  very 
slight  slope  from  the  horizontal  direction,  till  it  reaches  the  poussluiire  o  p  q.  It  traverses 
this  apartment,  and  returns  by  n  n  to  the  orifice  of  the  boiler,  h,  where  it  turns  vertically 
downwards,  and  descends  to  nearly  the  bottom  of  the  boiler,  discharging  at  that  pojiit 
the  cooled  and  therefore  denser  particles  of  Avater  to  replace  those  which  continually  issue 
upwards  at  d.  l  r  is  a  tube  surmoimted  with  a  funnel  for  keeping  the  range  of  pipes 
always  full  of  water ;  and  k  is  a  syphon  orifice  for  permitting  the  escape  of  the  ilisengaged 
air,  which  would  otherwise  be  apt  to  occupy  partially  the  pipes  and  obstruct  the  aqueous 
circulation. 

The  faster  the  water  gets  cooled  in  the  serpentine  tubes,  the  quicker  its  circulation 
will  be,  because  the  difference  of  density  between  the  water  at  the  top  and  bottom  of  the 
boiler,  which  is  the  sole  cause  of  its  movement,  will  be  greater,  n  represents  small 
eaucers  filled  with  water,  to  supply  the  requisite  moisture  to  the  heated  air,  and  to  place 

66 


^^1 
P. 


n 


1012 


INCUBATION,  ARTIFICUL. 


eggs,  arranged  along  the  trays  m  m,  in  an  atmosphere  analogous  to  that  under  the  body 
of  the  hen. 

When  we  wish  to  hatch  eggs  with  this  apparatus,  the  fire  is  to  be  kindled  in  the  boiler, 
and  as  soon  as  the  temperature  has  risen  to  about  100°  F.,  the  eggs  are  introduced ;  but 
only  one  twentieth  of  the  whole  number  intended,  upon  the  first  day ;  next  day,  a  like 
number  is  laid  upon  the  trays,  and  thus  in  succession  for  twenty  days,  so  that  upon  the 
twenty-first  day  ihe  eggs  first  placed  may  be  hatched,  for  the  most  part,  and  we  may 
obtain  daily  afterwards  an  equal  number  of  chicks.  In  this  way,  regularity  of  care  is 
established  in  the  rearing  of  them. 

During  the  first  days  of  incubation,  natural  as  well  as  artificial,  a  small  portion  of  the 
water  contained  in  the  egg  evaporates  by  the  heat,  through  the  shell,  and  is  replaced  by 
a  like  quantity  of  air,  wlirch  is  afterwards  useful  for  the  respiration  of  the  animal.  If  the 
warm  atmosphere  surrounding  the  eggs  were  very  dry,  such  a  portion  of  the  aqueous  part 
of  the  eggs  would  evaporate  through  the  pores  of  the  shells  as  would  endanger  the  future 
life  of  the  chick  in  ot'O.  The  transpiration  from  the  body  of  the  hen,  as  she  sits  upon  her 
eggs,  counteracts  this  desiccation  in  general ;  yet,  in  very  dry  weather,  many  hatching 
eggs  fail  from  that  cause,  unless  they  be  placed  in  moist  decomposing  straw.  The  water 
saucers  n  n  are  therefore  essential  to  success  in  artificial  incubation. 

After  the  chickens  are  hatched  they  are  transferred  into  the  nursery,  o  Q,  on  the  front 
side  of  which  there  is  a  small  grated  trough  filled  with  millet  seed.  Small  divisions  are 
made  between  the  broods  of  successive  days,  to  enable  the  superintendent  to  vary  their 
feeding  to  their  age. 

In  order  to  supply  an  establishment  of  the  common  kind,  where  100  eggs  are  to  be 
hatched  daily,  a  dozen  of  hens  would  be  needed,  and  150  eggs  must  be  placed  under  them, 
as  only  two  thirds  in  general  succeed.  At  this  rate,  4300  mothers  would  be  required  to 
sit.  Now  supposing  we  should  collect  ten  times  as  many  hens,  or  43,000,  we  should  not 
be  able  to  command  the  above  number  of  chickens,  as  there  is  seldom  a  tenth  part  of 
hens  in  a  brooding  state.  Besides,  there  would  be  in  this  case  no  fewer  than  720  hens 
every  day  coming  out  with  a  fresh  brood  of  chickens,  which  would  require  a  regiment  of 

supenntendents. 

Artificial  Incubation  by  means  </  Hot  Mineral  Waters.— This  curious  process  is 
^escribed  very  briefly  in  a  letter  by  M.  D*Arcet.  The  following  are  extracts  from  this 
^etter : — 

«'  In  June,  1825, 1  obtained  chickens  and  pigeons  at  Vichy,  by  artificial  incubation, 
effected  through  the  means  of  the  thermal  waters  of  that  place.  In  1827  I  went  to  the 
baths  of  Chaudes-Aigues,  principally  for  the  purpose  of  doing  the  same  thing  there. 
Finding  the  proprietor  a  zealous  man,  I  succeeded  in  making  a  useful  application  of  this 
source  of  heat  to  the  production  of  poultry. 

"  The  advantage  of  this  process  njay  be  comprehended,  when  it  is  known  that  the 
invalids  who  arrive  at  Vichy,  for  instance  in  the  month  of  May,  find  chickens  only  the 
size  of  quails ;  whereas,  by  this  means,  they  may  be  readily  supplied  six  months  old. 

"  The  good  which  may  be  done  by  establishing  artificisJ  incubation  in  places  where 
hot  springs  exist  is  incalculable  ;  it  may  be  introduced  into  these  establishments  without 
at  all  interfering  with  the  medical  treatment  of  patients,  since  the  hatching  would  go 
on  in  winter,  at  a  time  when  the  baths  for  other  purposes  are  out  of  use. 

"There  is  no  other  trouble  required  in  breeding  chickens,  by  means  of  hot  baths,  than 
to  break  the  eggs  at  the  proper  time ;  for,  when  the  apartments  are  closed,  the  whole  of 
the  interior  will  readily  acquire  a  sufficiently  elevated  and  very  constant  lemperature." 

In  addition  to  these  details  by  M.  D'Arcet,  a  letter  was  received  from  M.  Feigeris,  the 


INDIGU. 


1043 


proprietor  of  the  baths  at  Chaudes-Aigues  (Cantal),  in  which  he  describes  the  success 
he  had  in  following  M.  D'Arcet's  process.  This  consists  in  putting  the  eggs  into  a  small 
basket,  suspending  it  in  one  of  the  stove-rooms  heated  by  the  hot  mineral  water,  and 
turning  round  the  eggs  every  day.  The  very  first  trial  was  attended  with  success,  and 
no  failure  was  experienced  in  four  repetitions  of  it. 

INDIGO.  This  invaluable  blue  dye-stuff,  for  which  no  tolerable  substitute  has  been 
found,  was  known  to  the  ancients  as  a  pigment  under  the  name  of  indicum^  whence  its 
present  denomination.  In  modern  Europe,  it  first  came  into  extensive  use  in  Italy,  bii^ 
about  the  middle  of  the  16th  century,  the  Dutch  began  to  import  and  employ  it  in  con- 
siderable quantities.  Its  general  introduction  into  the  dye-houses  of  both  England  and 
France  was  kept  back  by  absurd  laws,  founded  upon  an  opinion  that  it  was  a  fugitive 
substance,  and  even  prejudicial  to  the  fibie  of  wool.     See  Dyeing,  p.  419. 

The  plants  which  afford  this  dye-drug  grow  in  the  East  and  West  Indies,  in  the  mid- 
dle regions  of  America,  in  Africa,  and  Europe.  They  are  all  species  of  the  genera  Jndj- 
gofer  a,  Isatis,  and  Nerium. 

The  following  are  cultivated : — Indigo/era  iinctoria  affords  in  Bengal,  Malabar, 
Madagascar,  the  Isle  of  France,  and  St.  Domingo,  an  article  of  middling  quality,  but 
in  large  quantity.  The  indigo/era  disperma,  a  plant  cultivated  in  the  East  Indies 
and  America,  grows  higher  than  the  preceding,  is  woody,  and  furnishes  a  superior 
dye  stuff.  The  Guatimala  indigo  comes  from  this  species.  Indigo/era  .Anil  grows  in 
the  same  countries,  and  also  in  the  West  Indies.  The  Indigo/era  jSrgenteay  which  grows 
also  in  Africa;  it  yields  little  indigo,  but  of  an  excellent  quality.  Indigo/era  Pseudo- 
tinctoria,  which  is  cultivated  in  the  East  Indies,  furnishes  the  best  of  all :  the  Indigofera 
Glauca  is  the  Egyptian  and  Arabian  species.  There  are  also  the  C(emkaj  dnerea  erecta, 
hirsuia,  glabra,  and  several  others.  The  Ntrium  tinctorium  of  the  East  Indies  affords 
some  indigo ;  as  does  the  Isalis  iinctoria^  or  Woad,  in  Europe ;  and  the  Polygonum 
tinctorium. 

The  districts  of  Kishenagar,  Jessore,  and  Moorshedabad,  in  Bengal,  ranging  from  88^ 
to  90°  E.  L.  and  22^°  to  24°  N.  L.,  produce  the  finest  indigo.  That  from  the  districts 
about  Burdwan  and  Benares  is  of  a  coarser  or  harsher  grain.  Tyroot,  in  lat.  26**,  yields 
a  tolerably  good  article.  The  portion  of  Bengal  most  propitious  to  the  cultivation  of 
indigo  lies  between  the  river  Hoogly  and  the  main  stream  of  the  Ganges. 

In  the  East  Indies,  after  having  ploughed  the  ground  in  October,  November,  and  the 
beginning  of  December,  they  sow  the  seed  of  the  indigo  plant  in  the  last  half  of  March 
and  the  beginning  of  April,  while  the  soil,  being  neither  too  hot  nor  too  dry,  is  most  pro- 
pitious to  its  germination.  A  light  mould  answers  best ;  and  sunshine,  with  occasional 
light  showers,  are  most  favorable  to  its  growth.  Twelve  pounds  of  seeds  are  sufficient 
for  sowing  an  acre  of  land.  The  plants  grow  rapidly,  and  will  bear  to  be  cut  for  the 
first  time  at  the  beginning  of  Ju)y,  nay,  in  some  districts,  so  early  as  the  middle  of  June. 
The  indications  of  maturity  are  the  bursting  forth  of  the  flower  buds,  and  the  expansion 
of  the  blossoms ;  at  which  period  the  plant  abounds  most  in  the  dyeing  principle. 
Another  indication  is  taken  from  the  leaves ;  which,  if  they  break  across,  when  doubled 
flat,  denote  a  state  of  maturity.  But  this  character  is  somewhat  fallacious,  and  depends 
upon  the  poverty  or  richness  of  the  soil.  When  much  rain  falls,  the  plants  grow  too 
rapidly,  and  do  not  sufficiently  elaborate  the  blue  pigment.  Bright  sunshine  is  most 
advantageous  to  its  production. 

The  first  cropping  of  the  plants  is  the  best;  after  two  months  a  second  is  made  ;  after 
another  interval,  a  third,  and  even  a  fourth ;  but  each  of  these  is  of  diminished  value. 
There  are  only  two  croppinss  in  America. 

Two  methods  are  pursued  to  extract  the  indigo  from  the  plant ;  the  first  effects  it  by 
fermentation  of  the  fresh  leaves  and  stems;  the  second,  by  maceration  of  the  dried 
'caves ;  the  latter  process  being  most  advantageous. 

1.  From  the  recent  leaves. — In  the  indigo  factories  of  Bengal  there  are  two  large 
•tone-built  cisterns,  the  bottom  of  the  first  being  nearly  upon  a  level  with  the  top  of 
the  second,  in  order  to  allow  the  liquid  contents  to  be  run  out  of  the  one  into  the  other. 
The  uppermost  is  called  the  fermenting  vat,  or  the  steeper ;  its  area  is  20  feet  square, 
and  its  depth  3  feet ;  the  lowermost,  called  the  beater  or  beatins:  vat,  is  as  broad  as  the 
other,  but  one  third  longer.  The  cuttings  of  the  plant,  as  they  come  from  the  field, 
are  stratified  in  the  steeper,  till  this  be  filled  within  5  or  6  inches  of  its  brim.  In  order 
that  the  plant,  during  its  fermentation,  may  not  swell  and  rise  out  of  the  vat,  beams  of 
wood  and  twigs  of  bamboo  are  braced  tight  over  the  surface  of  the  plants,  after  which 
water  is  pumped  upon  them  till  it  stands  within  three  or  four  inches  of  the  edge  of  the 
vessel.  An  active  fermentation  speedily  commences,  which  is  completed  within  14  or  15 
hours  ;  a  little  longer  or  shorter,  according  to  the  temperature  of  the  air,  the  prevailing 
winds,  the  quality  of  the  water,  and  the  ripeness  of  Ihe  plants.  Nine  or  ten  hours  after 
the  immersion  of  the  plant,  the  condition  of  the  vat  must  be  examined ;  frothy  bub- 
bles appear,  which  rise  like  little  pyramids,  are  at  first  of  a  white  color,  but  soon 


!« 


!( 


1044 


INBIGO. 


■fiUL 


p.:  f 

i:'  ?' 


become  gray-blue,  and  then  aeep  purple-red.  The  fermentation  is  at  this  lime 
violent  the  fluid  is  in  constant  commotion,  apparently  boiling,  innumerable  bubbles 
mount 'lo  the  surface,  and  a  copper-colored  dense  scum  covers  the  whole.  As  long  as 
the  liquor  is  agitated,  the  fermentation  must  not  be  disturbed;  but  when  it  becomes 
more  tranquil,  the  liquor  is  to  be  drawn  off  into  the  lower  cistern.  It  is  of  the  utmost 
consequence  not  to  push  the  fermentation  too  far,  because  the  quality  of  the  whole  indigo 
U  deteriorated :  but  rather  to  cut  it  short,  in  which  case  there  is,  indeed,  a  loss  of  weight, 
but  the  article  is  belter.  The  liquor  possesses  now  a  glistening  yellow  color,  which, 
when  the  indigo  precipitates,  changes  to  green.  The  average  temperature  of  the  liquor 
is  commonly  85°  Fahr. ;  its  specific  gravity  at  the  surface  is  10015;  and  at  the  bottom. 

As  soon  as  the  liquor  has  been  run  into  the  lower  cistern,  ten  men  are  set  to  work  to 
beat  it  with  oars,  or  shovels  4  feet  long,  called  busquets.  Paddle  wheels  have  also  been 
employed  for  the  same  purpose.  Meanwhile  two  other  laborers  clear  away  the  compres- 
sing  beams  and  bamboos  from  the  surface  of  the  upper  vat,  remove  the  exhausted  plant, 
set  it  to  dry  for  fuel,  clean  out  the  vessel,  and  stratify  fresh  plants  in  it.  The  fermented 
plant  appears  still  ereen,  but  it  has  lost  three  fourths  of  its  bulk  in  the  process,  or  from 
12  to  14  per  cent,  of  its  weight,  chiefly  water  and  extractive  matter. 

The  liquor  in  the  lower  vat  must  be  strongly  beaten  for  an  hour  and  a  half,  when  the 
indieo  begins  to  agglomerate  in  flocks,  and  to  precipitate.  This  is  the  moment  for 
judging  whether  there  has  been  any  error  committed  in  the  fermentation;  which  must 
be  corrected  by  the  operation  of  beating.  If  the  fermentation  has  been  defective,  much 
froth  rises  in  the  beating,  which  must  be  allayed  with  a  little  oil,  and  then  a  reddish 
tinge  appears.  If  large  round  granulations  are  formed,  the  beating  is  continued,  in 
order  to  -^ee  if  they  will  grow  smaller.  If  they  become  as  small  as  fine  sand,  and  il  the 
water  clears  up,  the  indigo  is  allowed  quietly  to  subside.  Should  the  vat  have  been  over 
fermented,  a  thick  fat-looking  crust  covers  the  liquor,  which  does  not  disappear  by  the 
introduction  of  a  flask  of  oil.  In  such  a  case  the  beating  must  be  moderated.  Whenever 
the  granulations  become  round,  and  begin  to  subside,  and  the  liquor  clears  up,  the  beating 
must  be  discontinued.  The  froth  or  scum  diffuses  itself  spontaneously  into  separate  minute 
particles,  that  move  about  the  surface  of  the  liquor;  which  are  marks  of  an  excessive 
fermentation.  On  the  other  hand,  a  rightly  fermented  vat  is  easy  to  work;  the  froth, 
though  abundant,  vanishes  whenever  the  granulations  make  their  appearance.  Ihe 
color  of  the  liquor,  when  drawn  out  of  the  steeper  into  the  beater,  is  bright  green  ;  but 
as  soon  as  the  agglomerations  of  the  indigo  commence,  it  assumes  the  color  of  Madeira 
wine;  and  speedily  afterwards,  in  the  course  of  beating,  a  small  round  grain  is  formed, 
which,  on  separating,  makes  the  water  transparent,  and  falls  down,  when  all  the  turbidity 

and  froth  vanish.  ^        .  ,  i.  *  «'»^ 

The  object  of  the  beating  is  three-fold:  first,  it  tends  to  disengage  a  great  quantity 
of  carbonic  acid  present  in'the  fermented  liquor ;  secondly,  to  give  the  newly  developed 
indigo  its  requisite  dose  of  oxygen  by  the  most  extensive  exposure  cf  its  particles  to 
the  atmosphere ;  thirdly,  to  agglomerate  the  indigo  in  distinct  flocks  or  granulations 
In  order  to  hasten  the  precipitation,  lime-water  is  occasiona  ly  added  to  the  fermented 
Uquor  in  the  progress  of  beating,  but  it  is  not  indispensable,  and  has  been  supposed 
capable  of  deteriorating  the  indigo.    In  the  front  of  the  beater  a  beam  is  fi^'^f  "PJ^^^ 
La  which  three  or  more  holes  are  pierced  a  few  inches  in  diameter.     These  are  closed 
with  plugs  during  the  beating,  but,  two  or  three  hours  after  it,  as  the  indigo  subsides, 
the  upper  plug  is  withdrawn   to  run  off  the  supernatant  liquor,  and  then  the  lower 
olugs  in  succession.    The  state  of  this  liquor  being  examined,  affords  an  indication  of 
the  success  of  both  the  processes.      When  the  whole  liquor  is  run  off,  a  laborer  enters 
the  vat,  sweeps  all  the  precipitate  into  one  corner,  and  empties  the  thinner  part  into  a 
spout  which  leads  into  a  cistern,  alongside  of  a  boiler,  20  feet  long,  3  feet  wide,  and  3  deep. 
When  all  this  liquor  is  once  collected,  it  is  pumped  through  a  bag  for  retaining  the 
impurities,  into  the  boiler,  and  heated  to  ebullition.    The  froth  soon  subsides,  and  shows 
an  oily  looking  film  upon  the  liquor.      The  indigo  is  by  this  process  not  only  freed  from 
the  vellow  extractive  matter,  but  is  enriched  in  the  intensity  of  its  color,  and  increased  m 
weight       From  the  boiler  the  mixture  is  run,  after  two  or  ihree  hours,  into  a  general 
rcieiver  called  the  dripping  vat,  or  table,  which,  for  a  factory  of  twelve  pairs  of  prepara- 
tion  vats,  is  20  feet  long,  10  feet  wide,  and  3  feet  deep;  having  a  false  bottom,  2  feet 
under  the  top  ed^e.      This  cistern  stands  in  a  basin  of  masonry  (made  water  tight  with 
Chunam  hydraulic  cement),  the  bottom  of  which  slopes  to  one  end,  in  order  to  facilitate 
the  drainage      A  thick  woollen  web  is  stretched  along  the  bottom  of  the  inner  vessel, 
to  act  as  a  filter.      As  long  as  the  liquor  passes  through  turbid,  it  is  pumped  back  into 
ihe  receiver       Whenever  it  runs  clear,  the  receiver  is  covered  with  anoiher  piece  of 
cloth   to  ex'clude   the  dust,  and  allowed   to   drain  at  its  leisure.      Next  morn mg  the 
drained  magma  is  put  into  a  strong  bag,  and  squeezed  in  a  press.      The  indigo  is  then 
carefully  taken  out  of  the  bag,  and  cut  with  a  brass  wire  into  bits,  about  3  inches  cube, 


INDIGO. 


1045 


which  are  dried,  in  an  airy  house,  upon  shelves  of  wicker  work.  During  the  drying,  a 
whitish  efflorescence  comes  upon  the  pieces,  which  must  be  carefully  removed  with  a 
brush.  In  some  places,  particularly  on  the  coast  of  Coromandel,  the  dried  indigo  lumps 
are  allowed  to  effloresce  in  a  cask  for  some  time,  and  when  they  become  hard  they  are 
wiped  and  packed  for  exportation. 

From  some  experiments  it  would  appear  that  the  gas  disengaged  during  the  middle 
period  of  the  fermentation  is  composed  in  100  parts  of  27*5  carbonic  acid,  5-8  oxygen, 
and  66-7  azote;  and  towards  its  end,  of  40*5  carbonic  acid,  4-5  oxygen,  and  55-0  azote. 
The  fermenting  leaves  apparently  convert  the  oxygen  of  the  atmosphere  into  carbonic 
acid  gas,  and  leave  its  azote;  besides  the  quantity  of  carbonic  acid  which  they  spon- 
taneously evolve.  Carbureted  hydrogen  does  not  seem  to  be  disengaged.  That  the 
liquor  in  the  beating  vat  absorbs  oxygen  from  the  air  in  proportion  as  the  indigo  becomes 
flocculent  and  granular,  has  been  ascertained  by  experiment,  as  well  as  that  sunshine 
accelerates  the  separation  of  the  indigo  blue.  Out  of  1000  parts  of  the  fermented  liquor 
of  specific  gravity  1*003,  the  blue  precipitate  may  constitute  0-75  of  a  part.  Such  a  pro- 
portion upon  the  great  scale  is  however  above  the  average,  which  is  not  more  than  0'5. 
When  lime  water  is  added,  an  extractive  matter  is  thrown  down,  which  amounts  to  from 
20  to  47  parts  in  1000  of  the  liquor.  It  has  a  dark  brown  tint,  a  viscid  appearance,  an 
unpleasant  smell,  and  a  bitter  taste.  It  becomes  moist  in  damp  air,  and  dissolves  in 
water  without  decomposition.  It  is  precipitated  by  lime,  alkalis,  infusion  of  galls,  and 
acetate  of  lead.  All  indigo  contains  a  little  lime  derived  from  the  plant,  even  though 
none  has  been  used  in  its  preparation. 

2.  Indigo  from  dried  leaves. — The  ripe  plant  being  cropped,  is  to  be  dried  in  sunshine 
from  9  o'clock  in  the  morning  till  4  in  the  afternoon,  during  two  days,  and  thrashed  to 
separate  the  stems  from  the  leaves,  which  are  then  stored  up  in  magazines  till  a  sufficient 
quantity  be  collected  for  manufacturing  operations.  The  newly  dried  leaves  must  be  free 
from  spots,  and  friable  between  the  fingers.  When  kept  dry,  the  leaves  undergo,  in  the 
course  of  4  weeks,  a  material  change,  their  beautiful  green  tint  turning  into  a  pale  blue- 
gray,  previous  to  which  the  leaves  afford  no  indigo  by  maceration  in  water,  but  subse- 
quently a  large  quantity.    Afterwards  the  product  becomes  less  considerable. 

The  following  process  is  pursued  to  extract  indigo  from  the  dried  leaves.  They  are 
infused  in  thes'eeping  vat  with  six  limes  their  bulk  of  water,  and  allowed  to  macerate  for 
two  hours  with  continual  stirring  till  all  the  floating  leaves  sink.  The  fine  green  liquor 
is  then  drawn  olV  into  the  beater  vat,  for  if  it  stood  longer  in  the  steeper,  some  of  the  in- 
digo would  settle  among  the  leaves  and  be  lost.  Hot  water,  as  employed  by  some  manu- 
facturers, is  not  necessary.  The  process  with  dry  leaves  possesses  this  advantage,  that 
a  provision  of  the  plant  may  be  made  at  the  most  suitable  times,  independently  of  the 
\  icissitudes  of  the  weather,  and  the  indigo  may  be  uniformly  made ;  and  moreover,  that 
the  fermentation  of  the  fresh  leaves,  often  capricious  in  its  course,  is  superseded  by  a 
much  shorter  period  of  simple  maceration. 

The  process  for  obtaining  indigo  from  the  Nerium  is  altogether  the  same,  but  hot 
water  has  been  generally  applied  to  the  dried  leaves.  For  woad,  hot  water  must  be  em- 
ployed, and  also  lime  water  as  a  precipitant,  on  account  of  the  small  proportion  of  indigo 
in  the  plant.  Dilute  muriatic  acid  is  digested  upon  the  woad  indigo  to  remove  the  lime, 
without  which  no  dye  could  be  precipitated.  According  to  the  warmth  of  the  summer 
and  the  ripeness  of  the  plant,  from  2  to  5  ounces  of  indigo  may  be  obtained  from  100 
pounds  of  the  dried  woad,  or  upon  an  average  4  ounces  to  the  hundred  weight. 

The  indigo  found  in  European  commerce  is  imported  from  Bengal,  Coromandel, 
Madras,  the  Mauritius,  Manilla,  and  Java  in  the  Eastern  hemisphere;  from  Senegal, 
Caraccas,  Guatiinala,  Brazil  (South  Carolina  and  Louisiana  in  small  quantity),  and  for 
merly  from  the  West  India  islands,  especially  St.  Domingo.  Its  quality  depends  upon  the 
species  of  the  plant,  its  ripeness,  the  soil  and  climate  of  its  growth,  and  mode  of  manu- 
facture. The  East  Indian  and  Brazilian  indigo  comes  packed  in  chests,  the  Guatimala 
in  ox-hides,  called  surons. 

The  organ  which  affords  the  indigo  is  confined  entirely  to  the  pellicle  of  the  leaves,  ano 
exists  in  largest  quantity  at  the  commencement  of  maturation  while  the  plant  is  in  flower. 
The  indigofera  is  remarkable  for  giving  a  blue  tinge  to  the  urine  of  cows  that  feed  upon 
its  leaves. 

According  to  some  manufacturers,  the  plants  should  be  cut  down  in  dry  weather,  an 
hour  or  two  before  sunset,  carried  off  the  field  in  bundles,  and  immediately  spread  upon 
a  dry  floor.  Next  morning  the  reaping  is  resumed  for  an  hour  and  a  half,  befure  the  sun 
acts  too  powerfully  upon  vegetation  ;  and  the  plants  are  treated  in  the  same  way.  Both 
cuttings  become  sufficiently  dry  by  3  o'clock  in  the  afternoon,  so  as  to  permit  the  leaves 
to  be  separated  from  the  stems  by  thrashing.  They  are  now  thoroughly  dried  in  the 
sunshine,  then  coarsely  bruised,  or  sometimes  ground  to  powder  in  a  mill,  and  packed  up 
for  the  operations  of  manufacture. 

In  the  spring  of  1830  I  subjected  a  variety  of  specimens  of  indigo  to  comparative 


%x 


'i 

u 


1046 


INDIGO. 


analyses,  by  dissolving  a  few  grains  of  each  in  strong  snlphuric  acid,  diluting  the  sola- 
lions  with  an  equal  volume  of  water,  and  determining  the  resulting  shade  of  color  in  a 
hollow  prism  of  plate  glass,  furnished  with  a  graduated  scale.  The  following  are  the 
results,  compared  to  the  shade  produced  by  a  like  weight  of  absolute  indigo. 

I.  East  India  Indigos ;  prices  as  at  the  last  October  sales. 


No. 


1 
2 
3 
4 
5 

6 

7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 


Price. 


».  d, 

3  9 

3  6 

3  3 

4  3 
4  2 

4  9 


Real  Tndigo 
in  100  parts. 


5 
6 
6 
7 
2 
3 
4 
2 
2 
3 
1 


3 
6 
0 
0 
3 
6 
3 
0 
4 
3 
9 


42 

56-5 

46-0 

54-5 

75-0 

60-0 

70-0 

60-0 

66f 

75 

37-6 

60-0 

580 

"in" 

54 
29 


Characters  by  the  Brokers. 


Broken,  middling  violet,  and  coppery  violet  spotted. 
Ditto,  a  little  being  coppery  violet  and  copper. 
Ditto,  middling  red  violet,  dull  violet  and  lean. 
Large  broken,  and  square,  even  middling  red  violet. 
Much  broken  and  very  small,  very  crumbly  and  limy,  soft, 

good  violet. 
Square  and  large  broken,  1  middling  violet,  and  |  good 

coppery  violet. 
Large  broken,  very  good;  paste  a  little  limy,  good  violet. 
Square  and  large  broken,  soft,  fine  paste,  fine  violet. 
Square,  ditto,  good  red  violet. 
Square,  ditto,  fine  purple  and  blue. 
Middling  ordinary  Madras. 
Good  Madras. 
Very  fine  ditto. 
Low,  pale  Oude. 
Middling,  ordinary  Oude. 
Good  Oude. 
Lundy,  very  low  quality. ^^ 


J 


n.  American  Indigos ;  wholesale  prices  at  present.     (March,  1830.) 


Indigo. 

No. 

Price. 

Parts 

in  100. 

Indigo. 

No. 

Price. 

Parts 

in  100. 

*.    d. 

8.   d. 

Caraccas  flor.    -    - 

1 

6     0 

54i 

Guatimala  ... 

6 

5    0 

50 

Guatimala     -    -    - 

2 

5     0 

33| 

— 

7 

5    3 

35 

3 

3     2 

19 

-^ 

8 

4    8 

46 

_ 

4 

4    6 

32| 

•^ 

9 

4    8 

33| 

— 

5 

5    4 

50 

■^ 

10 

5    4 

50 

Properties  of  Indigo. — ^It  possesses  a  dark  blue  color,  passing  into  violet-purple,  is  void 
of  taste  and  smell,  dull,  but  by  rubbing  with  a  smooth  hard  body,  it  assumes  the  lustre 
and  hue  of  copper.  It  occurs  sometimes  less  and  sometimes  more  dense  apparently  than 
water,  which  circumstance  depends  upon  its  freedom  from  foreign  impurities,  as  well 
as  upon  the  treatment  of  its  paste  in  the  boiling,  pressing,  and  drying  operations.  It 
IS  insoluble  in  water,  cold  alcohol,  ether,  muriatic  acid,  dilute  sulphuric  acid,  cold 
ethereous  and  fat  oils ;  but  boiling  alcohol  and  oils  dissolve  a  little  of  it,  which  they 
deposite  on  cooling.    Creosote  has  the  properly  of  dissolving  indigo. 

Indigo  is  a  mixture  of  several  dye-stufis,  and  other  substances.  Berzelius  found  in  it  a 
matter  resembling  vegetable  gluten  or  gliadine,  a  brown,  red,  and  blue  pigment,  besides 
oxyde  of  iron,  clay,  lime,  magnesia,  and  silica. 

1.  Indigo  gluten  or  gliadine  is  dissolved  along  with  the  calcareous  and  magnesian  salts 
by  acids.  If  the  powder  be  treated  with  dilute  sulphuric  acid,  if  the  solution  be  saturated 
with  carbonate  of  lime,  evaporated  to  dryness,  and  its  residuum  treated  with  alcohol ;  the 
solution  thus  formed  leaves,  after  being  evaporated,  a  yellow  transparent  extract,  easily 
soluble  in  water,  more  difl5cultly  in  acid  liquids ;  showing  that  acids  extract  only  a  portion 
of  the  gliadine  from  the  indigo.  It  yields,  by  dry  distillation,  much  ammonia,  a  fetid  oil, 
and  comports  itself  in  other  respects  like  vegetable  gluten. 

2.  Indigo-broivn  occurs  in  combination  with  lime,  as  also  with  vegetable  acid  in  con- 
siderable quantity,  and  more  abundantly  in  the  coarser  sorts  of  indigo  than  in  the  finer. 
Indigo  purified  by  acids  is  to  be  treated  with  hot  strong  caustic  ley,  which  dissolves  the 
indigo- brown ;  the  liquid  part  of  the  mixture  passes  with  difiicully  through  the  filler 
is  black-brown,  opaque,  and  holds  some  indigo-blue  in  solution,  or  diffused  in  fine  powder 


iNDIGO. 


1047 


The  alkali  being  neutralized  with  acetic  acid,  the  liquor  is  to  be  evaporated,  and  alcohol 
poured  on  the  residuum,  whereby  the  alkaline  acetate  is  dissolved  out  from  the  brown. 

This  pigment  is  a  dark  brown,  almost  black,  but  is  not  yet  entirely  :*eprived  of  the 
other  constituents  of  indigo.  It  is  nearly  tasteless,  is  combustible,  aflTords,  by  dry  distilla- 
tion,  ammonia  and  fetid  oil,  forms  with  acids  combinations  hardly  soluble  in  water,  with 
alkalis  soluble  ones,  but  with  earths  hardly  soluble.  Lime  possesses  the  properly  of  pre- 
cipitating the  indigo-brown  completely  from  its  alkaline  solution.  Chlorine  occasions  a 
pale  yellow  brownish  precipitate,  which  consists  of  indigo  brown  and  muriatic  acid,  but 
causes  no  further  change.  By  drying,  it  becomes  again  dark  colored.  Indigo-brown 
seems  to  exist  also  in  woad.  ^ 

3.  Indigo-redy  or  more  properly  red  resin  of  indigo.  This  may  be  obtamed  by  boiling 
alcohol  of  sp.  grav.  0*830  upon  some  indigo  which  has  been  previously  treated  with  acids 
and  alkalis ;  for  the  red  substance  is  hardly  soluble  in  cold  alcohol.  The  solution  is  dark 
red,  opaque,  and  leaves,  by  distillation,  the  indigo-red  in  the  form  of  a  black-brown  pow- 
der, or  a  Rlislening  varnish,  slightly  soluble  in  alcohol  and  ether.  Alkalis  do  not  dissolve 
it,  but  conewitrated  sulphuric  acid  forms  with  it  a  dark  yellow  dye,  from  which  water 
causf  s  no  precipitation ;  wool  extracts  the  color  from  the  acid  solution,  and  becomes 
of  a  dirty  brown  hue.  Chlorine  does  not  seem  capable  of  destroying  the  color,  for  though 
it  makes  it  yellow,  it  becomes  as  dark  as  evpr  on  being  dried.  Indigo-red  melts  with 
heat,  burns  with  a  bright  flame,  aflTords,  when  heated  in  vacuo,  first  a  white  cnstalhne 
sublimate,  and  then  unchanged  indigo-red.    That  white  matter  is  changed  by  nitric  acid 

into  indigo-red. 

4.  Indigo-bluBy  or  pure  indigo,  remains,  after  treating  the  indigo  of  commerce  with 
lilute  acid,  alkalis,  and  alcohol;  it  retains,  however,  still  traces  of  the  matters  thereby 
extracted,  along  with  some  earthy  substances.  In  order  to  procure  indigo  blue  in  its 
utmost  purity,  we  must  deoxydize  the  above  blue  residuum,  thus  form  colorless  indigo, 
which  again  acquires  a  blue  color  from  the  air,  and  constitutes  the  pure  pigment.  For 
this  purpose  the  above  moist  indigo  is  to  be  mixed  with  slaked  lime,  green  sulpliate  of 
iron,  and  hot  water  in  an  air-tight  matrass.  The  indigo  when  deoxydized  by  proloxyde 
of  iron  being  soluble  in  lime-water,  the  clear  yellow  solution  is  to  be  poured  off",  and  ex- 
posed to  the  air.  The  indigo  absorbs  oxygen,  and  becomes  again  blue.  By  digestion 
with  dilute  muriatic  acid  the  foreign  matters  are  dissolved,  and  may  then  be  washed  away 
with  distilled  water,  from  the  absolute  indigo. 

The  indigo-blue  obtained  in  this  manner  has  a  cast  of  purple  red,  displaying  the 
characteristic  copper  lustre  in  a  high  degree,  but  in  powder,  it  is  blue.     It  is  void 
of  taste   and   smell,  is  by  my  experiments  of  specific  gravity   1-50,  aflTords   at   554* 
Fahr.  a  purple  vapor,  and   sublimes  in  shining   purple  scales,  or  slender  needles  in 
an  apparatus  open   to  the   air,  whereby,  however,  much  of   it  is   destroyed.      Some 
carbon  remains  after  the  sublimation.     A  quick  heat  produces  most  sublimate.     These 
needles  contain  a  brown  oily  matter,  which  may  be  dissolved  out  by  means  of  hot  alco- 
hoi.     Their  specific  gravity  is  1-35,  according  to  Mr.  Crum.     The  sublimate  from  com- 
mon indigo  does  not  contain  any  oil,  but  some  indigo-red  and  the  above  white  crystalline 
matter.     According  to  Mr.  Crum,  indigo-blue  consists  of  carbon,  73-22 ;  oxygen,  12-60 
azote,  11-26;  hydrogen,  2*92 ;  while  according  to  Dumas,  crystallized  indigo  consists  of 
carbon,  73-26;  oxygen,  10-43;   azote,  13-81;  and  hydrogen,  2-50;   precipitated  indigo 
consists  of  carbon,  '74-81 ;  oxygen,  7-88 ;  azote,  13-98  ;  and  hydrogen,  333  ;  sublimed 
indigo,  of  carbon,  71-71;  oxygen,  12-18;  azote,  13-45;  hydrogen,  2-66.     My  own  ana- 
lysis aflTorded— carbon,  71-37 ;  oxygen,  14-25;  azote,  1000  ;  hydrogen,  4-38.     In  another 
analysis  of  Dumas,  3-93  parts  of  hydrogen  were  obtained.     Hence  we  must  infer  thai 
considerable  diflferences  exist  in  the  composition  of  indigo  in  its  purest  stale.    Reagf  nl> 
met  upon  it  much  as  upon  common  indigo.     Chlorine,  iodine,  and  bromine  convert  it  mic 
a  reddish  brown  soluble  substance.     Concentrated  sulphuric  acid,  especially  the  smoking 
or  anhydrous  of  Nordhausen,  dissolves  indigo-blue  with  the  disengagement  of  heat,  but  it 
makes  it  suff'er  some  modification  ;  for  though  it  retains  an  intense  dark  blue  color,  it  has 
become  soluble  in  water,  and  may  be  blanched  by  light,  which  does  not  happen  with  indigo 
itself.     Nitric  acid  destroys  indigo-blue,  forms  indigotic  (carbazotic)  acid,  carbonic  acid, 
artificial  resin,  and  bitter  principle.  r    n    v 

Indigo-blue  may  be  reduced  by  substances  oxydized,  with  the  co-operation  of  alkalis 
or  alkaline  earths;  for  example,  by  such  substances  as  have  a  strong  aflSnity  for  oxygen, 
and  are  imperfectly  saturated  with  this  principle,  as  the  sulphurous  and  phosphorous 
acids  and  their  salts,  the  proloxydes  of  iron  and  manganese,  the  proloxyde  salts  of  tin, 
and  the  corresponding  compounds  of  chlorine,  as  the  prolo-chloi  ides  of  lin  and  iron;  and 
Ihe  solution  of  the  former  in  potash.  When  in  these  circumstances,  in  the  presence  of 
alkali,  a  deoxydation  or  reduction  of  the  indigo-blue  lakes  place,  the  other  bodies  get 
oxydized  by  absorption  of  the  oxygen  of  the  indigo-blue ;  the  proloxydes  become  per- 
oxydes,  and  the  acids  in  ous  become  acids  in  icy  &c.  Several  metallic  sulphurels  also 
reduce  the  indigo-blue  in  the  same  predicament,  as  the  sulphurels  of  potassium,  of  cal- 


1048 


INDIGO. 


m 


cium,  of  anvimony,  and  of  arsenic  (orpiment.)  A  similar  influence  is  exercised  by  fer- 
menting vegetable  substances,  such  as  woad,  madder,  bran,  raw  sugar  (molasses),  starch, 
sirup,  in  consequence  of  the  formation  of  carbonic  and  acetic  acids,  by  absorption  of  the 
oxygen  of  the  indigo-blue,  for  acetic  acid  and  acetic  salts  are  found  in  the  liquor  of  the 
warm  blue  vat,  in  which  indigo  has  been  reduced  by  means  of  woad,  madder,  and  bran. 

Formation  of  colorless  reduced  indigo-bine^  or  indigotine. — Purified  indigo-blue  is  to 
be  treated  with  copperas  and  slaked  lime,  as  above  described ;  or  the  clear  wine-yellow 
supernatant  liquor  of  the  cold  blue-vat  mixture  is  to  be  taken,  run  by  a  syphon  into 
a  matrass,  a  few  drops  of  concentrated  acetic  or  sulphuric  acid,  deprived  of  air,  are  to  be 
poured  into  it,  and  the  vessel,  being  made  quite  full,  is  to  be  well  corked.  The  reduced 
indigo  soon  falls  in  white  flocks,  or  crystalline  scales.  They  must  be  edulcorated  upon 
a  filter  with  water  deprived  of  its  air  by  boiling,  then  pressed  between  folds  of  blotting- 
paper,  and  dried  under  the  receiver  in  vacuo.  Indigo-blue  may  likewise  be  reduced  and 
dissolved  by  solution  of  hydro-sulphuret  of  ammonia ;  and  the  colorless  indigotine  maybe 
precipitated  by  muriatic  acid. 

The  reduced  indigo  is  sometimes  white  at  the  instant  of  its  elimination,  sometimes 
grayish,  of  a  silky  lustre,  but  becomes  very  readily  greenish,  blue  green,  and  blue,  in  the 
air ;  in  which  case  it  absorbs,  according  to  Berzelius,  4-2  per  cent,  of  oxysen  ;  but  ac- 
cording to  Liebeg,  11*5  per  cent.  It  is  void  of  taste  and  smell,  is  insoluble  in  water; 
well  boiled  water  free  from  air  is  not  affected  by  it,  but  is  turned  blue  by  common  water. 
It  dissolves  in  alcohol  and  ether  into  a  yellow  dye ;  not  in  dilute  acids,  but  in  concen- 
trated sulphuric  acid,  whereby  probably  a  portion  of  this  is  decomposed,  and  some  hypo- 
sulphurous  acid  formed;  the  color  of  this  solution  is  blue.  Solutions  of  the  caustic  and 
carbonated  alkalis,  even  the  alkaline  earths,  readily  dissolve  reduced  indigo  into  a  wine- 
yellow  liquid;  but  in  contact  with  air,  oxygen  is  absorbed,  and  indieo-blue  falls,  while 
a  purple-colored  froth,  passing  into  copper-red,  appears  "pon  the  surface,  just  as  in  the 
indigo  vats  of  the  dyer. 

The  reduced  indigo  may  be  combined,  by  means  of  complex  affinity,  with  other  bases, 
with  the  exception  of  the  oxydes  of  copper,  zinc,  and  mercury,  which  oxydize  it.  These 
combinations  are  white,  in  part  crystallizable,  become  speedily  blue  in  the  air,  and  afford 
by  sublimation  indigo-blue.  Berzelius  formed  with  lime  a  two-fold  combination ;  one 
easily  soluble  in  water,  and  another  difficultly  soluble,  of  a  lemon  color,  which  contained 
an  excess  of  lime ;  this  is  formed  both  in  the  hot  and  the  cold  blue  vat ;  in  the  latter  it  is 
occasioned  by  an  overdose  of  lime. 

When  pure  indigo-blue  is  treated  with  concentrated  sulphuric  acid,  and  particularly  with 
six  times  its  weight  of  the  smoking  dry  acid,  it  dissolves  completely,  and  several  different 
compounds  are  produced  in  the  solution.  There  is  first  a  blue  sulphate  of  indigo ;  secondly, 
a  similar  compound  with  the  resulting  hyposulphurous  acid;  thirdly,  a  combination  of 
sulphuric  acid  with  the  purple  of  indigo  (called  Phsenicin  by  Crum),  a  peculiar  substance, 
generated  from  indigo-blue.  These  three  compounds  are  here  dissolved  in  an  excess  of 
sulphuric  acid.  The  more  concentrated  the  sulphuric  acid  is,  the  more  blue  hyposulphite 
is  formed.  The  solution  in  smoking  acid,  when  diluted  with  water  and  filtered,  affords  a 
considerable  precipitate  of  indigo  purple,  which  that  in  oil  of  vitriol  does  not.  The  vapoi 
of  anhydrous  sulphuric  acid  combines  with  indigo-blue  into  a  purple  fluid. 

In  order  to  obtain  from  the  dark  blue  solution  each  of  these  blue  acids  in  a  pure  state, 
we  must  dilute  it  with  forty  times  its  weight  of  water,  and  immerse  in  the  filtered 
liquor,  well  washed  woo.  or  flannel,  with  which  the  blue  acids  combine,  while  most  of  the 
sulphuric  acid  and  some  other  foreign  substances  remain  free  in  the  liquor.  The  wool 
must  be  then  scoured  with  water  containing  about  a  half  per  cent,  of  carbonate  of  am- 
monia, or  potash,  which  neutralizes  both  of  the  blue  acids,  and  produces  a  blue  compound, 
This  being  evaporated  to  dryness  at  the  temperature  of  140"  F.,  alcohol  of  0-833  is  to  be 
poured  upon  the  residuum,  which  dissolves  the  blue  hyposulphite,  but  leaves  the  blue 
sulphate  undissolved.  From  either  salt,  by  precipitating  with  acetate  of  lead,  by  acting 
upon  the  precipitate  with  sulphureted  hydrogen  water,  and  evaporation,  either  of  the 
two  blue  acids  may  be  obtained.  They  may  be  both  evaporated  to  dryness,  especially 
Ike  blue  sulphate  of  indigo ;  they  both  become  somewhat  moist  in  the  air,  they  are  very 
soluble  in  water,  and  the  blue  sulphate  also  in  alcohol;  they  have  a  not  unpleasant  smell, 
and  an  acid  astringent  taste. 

From  these  habitudes,  particularly  in  reference  to  the  bases,  it  appears  that  indigo-blue 
does  not  comport  itself  like  a  saline  base  towards  the  acids,  but  rather  like  an  acM,  since 
it  enters  into  the  salts,  just  as  the  empyreumatic  oil  of  vinegar  and  oil  of  turpentine  do 
into  resin  soaps.  The  blue  pigment  of  both  acids  is  reduced  by  zinc  or  iron  without  the 
disengagement  of  hydrogen  gas ;  as  also  by  sulphureted  hydrogen,  tepid  protochloride  of 
tin,  while  the  liquor  becomes  yellow. 

Indigo-bliie  sulphate  of  potash,  or  ceruleo-sulphate  of  potash,  may  be  obtained  by 
extracting  the  blue  color  from  the  wool  by  water  containing  1  per  cent,  of  car- 
bonate of  potash,  evaporating  nearly   to   dryness,  treating  the   extract  with   alcohol 


INDIGO. 


1049 


to  remove  the  indigo-blue  hyjtosulphi/e,  then  with  acetic  acid  and  alcohol  to 
remove  any  excess  of  carbonate  of  potash.  It  is  found  in  commerce  under  the 
name  of  precipitated  indigo,  indigo  paste,  blue  carmine,  and  soluble  indigo.  To  prepare 
it  economically,  indigo  is  to  be  dissolved  in  ten  times  its  weight  of  concentrated  sulphuric 
acid;  the  solution  after  twenty-four  hours  is  to  ba diluted  with  ten  times  its  weight  of 
water,  filtered,  and  imperfectly  saturated  with  carbonate  of  potash  ;  whereby  a  blue  pow- 
der falls  down ;  for  the  resulting  sulphate  of  potash  throws  down  the  ceruleo-sulphate, 
while  the  hyposulphite  of  potash  remains  dissolved.  It  is  a  dark  blue  copper  shining 
powder,  soluble  in  140  parts  of  cold  water,  and  in  much  less  of  boiling  water.  It  is  made 
use  of  as  a  dye,  and  to  give  starch  a  blue  tint.  When  mixed  with  starch  ini  cakes,  it  is 
sold  under  the  name  of  6/tt«for  washerwomen. 

Ceruleo-sulphate  of  ammonia  may  be  formed  in  the  same  way.  It  is  much  more 
soluble  in  water.  Ceruleo-sulphate  of  lime  is  obtained  by  saturating  the  above  dilute 
acid  with  chalk,  filterin?  to  separate  the  undyed  gypsum,  and  washing  with  water  till 
the  purple  color  be  extracted.  This  liquor,  evaporated  and  decomposed  by  alcohol, 
affords  a  bluish  flocky  precipitate,  which  is  more  soluble  in  water  than  common  gypsum, 
and  dries  up  in  a  purple-blue  film.  Ceruleo-sulphate  of  alumina  may  be  obtained  by 
double  affinity;  it  is  dark  blue  while  moist,  but  becomes  black-blue  by  drying,  and  is  sol- 
uble in  water. 

The  blue  present  in  all  these  salts  of  ceruUne  is  destroyed  by  sunshine,  becomes  greenish- 
gray  by  caustic  alkalis ;  and  turns  immediately  yellow-brown  by  alkaline  earths.  But 
when  the  solution  is  very  dilute,  the  color  becomes  first  green,  then  yellow.  The  car- 
bonates of  alkalis  do  not  produce  these  changes.  Nitric  acid  decomposes  the  color  quickly. 
Mr.  Crum  considers  ceruline  to  be  a  combination  of  indigo-blue  with  water. 

Phenicine,  or  indigo-purple  combined  with  sulphuric  acid,  is  obtained  when  the  solution 
of  indigo-blue  in  concentrated  sulphuric  acid  has  been  diluted  for  a  few  hours  with 
water,  and  then  filtered.  It  seems  to  be  an  intermediate  body  into  which  the  indigo-blue 
passes,  before  it  becomes  soluble  ceruline.  Hence  it  occurs  in  greater  quantity  soon  after 
digestinsr  the  indigo  with  the  acid,  than  afterwards.  It  is  dark  blue,  dissolves  gradually 
in  water,  affords  after  evaporation  a  blue  residuum,  of  the  same  appearance  as  the  above 
blue  acids.  When  a  salt  is  added  to  it  a  purple  precipitate  ensues,  which  is  a  compound 
of  indigo-purple,  sulphuric  acid,  and  the  base  of  the  salt.  Indigo-purple  is  reduced  by 
bodies  having  a  strong  attraction  for  oxygen,  if  a  free  alkali  or  alkaline  earth  be  present, 
and  its  solution  is  yellow,  but  it  becomes  blue  in  the  atmosphere.  According  to  Mr.  Crum, 
Phenicine  contains  half  as  much  combined  water  as  ceruline. 

The  table  which  I  published  in  1830  (as  given  above)  shows  very  clearly  how  much 
the  real  quality  and  value  of  indigo  differ  from  its  reputed  value  and  price,  as  estimated 
from  external  characters  by  the  brokers.  Various  test  or  proof  processes  of  this  drug 
have  been  proposed.  That  with  chlorine  water  is  performed  as  follows.  It  is  known 
that  chlorine  destroys  the  blue  of  indigo,  but  not  the  indigo-red  or  indigo-brown,  which 
by  the  resulting  muriatic  acid  is  thrown  down  from  the  sulphuric  solution  in  flocks,  and 
the  chlorine  acts  in  the  same  way  on  the  gliadine  or  gluten  of  the  indigo.  Pure  indigo-blue 
is  to  be  dissolved  in  10  or  12  parts  of  concentrated  sulphuric  acid,  and  the  solution  is  to 
be  diluted  with  a  given  weight  of  water,  as,  for  example,  1000  parts  for  1  of  indigo-blue. 
If  we  then  put  that  volume  of  liquor  into  a  graduated  glass  tube,  and  add  to  it  chlorine 
water  of  a  certain  strength  till  its  blue  color  be  destroyed  by  becoming  first  green  and 
then  red-brown,  we  can  infer  the  quantity  of  color  from  the  quantity  of  chlorine  water 
expended  to  produce  the  effect.  The  quantity  of  real  indigo-blue  cannot,  however,  be 
estimated  with  any  accuracy  in  this  way,  because  the  other  coloring  matters  in  the  drug 
act  also  upon  the  chlorine ;  and,  indeed,  the  indigo  itself  soon  changes  when  dissolved  in 
sulphuric  acid  even  out  of  access  of  light,  while  the  chlorine  water  itself  is  very  suscej)tible 
of  alteration.  Perhaps  a  better  appreciation  might  be  made  by  avoiding  the  sulphuric 
acid  altogether,  and  adding  the  finely  powdered  indigo  to  a  definite  volume  of  the  chlorine 
water  till  its  color  ceased  to  be  destroyed,  just  as  Prussian-blue  is  decolored  by  solution 
of  potash  in  making  the  ferro-cyanide. 

Another  mode,  and  one  susceptible  of  great  precision,  is  to  convert  10  or  100  graiu 
of  indigo  finely  powdered  into  its  deoxydized  state,  as  in  the  blue  vat  by  the  proper 
quantity  of  slaked  lime  and  solution  of  green  sulphate;  then  to  precipitate  the  indigo 
collect  and  weish  it.  The  indigo  should  be  ground  upon  a  muller  along  with  the  quick- 
lime, ihe  levigated  mixture  should  be  diluted  with  water,  and  added  to  the  solution  of  the 
copperas.  This  exact  analytical  process  requires  much  nicety  in  the  operator,  and  can 
hardly  be  practised  by  the  broker,  merchant,  or  manufacturer. 

Employment  of  indigo  in  dyeing.  —  As  indigo  is  insoluble  in  water,  and  as  it  can  pene- 
trate the  fibres  of  wool,  cotton,  silk,  and  flax,  only  when  in  a  state  of  solution,  the  dyer 
must  study  to  bring  it  into  this  condition  in  the  most  complete  and  economical  manner 
This  is  effected  either  by  exposing  it  to  the  action  of  bodies  which  have  an  affinity  foi 
oxygen  superior  to  its  own,  such  as  certain  metals  and  metallic  oxydes,  or  by  mixing  il 


1050 


INDIGO. 


with  fermenting  matters,  or,  finally,  by  dissolving  it  in  a  strong  acid,  such  as  the  sulphuric. 
The  second  of  the  above  methods  is  called  the  warm  blue,  or  pastel  vat ;  and  being  the 
most  intricate,  we  shall  begin  with  it. 

Before  the  substance  indiso  was  known  in  Europe,  woad  having  been  used  for  dyeins 
blue,  gave  ihe  name  of  woad  vats  to  the  apparatus.  The  vats  are  sometimes  made  of 
copper,  at  other  times  of  iron  or  wood,  the  last  alone  being  well  adapted  for  the  employ- 
ment of  steam.  The  dimensions  are  very  variable ;  but  the  following  may  be  considered 
as  the  average  size  :  depth,  7|  feel ;  width  below,  4  feet,  above,  5  feet.  The  vats  are 
built  in  such  a  way  that  the  fire  does  not  aflTect  their  bottom,  but  merely  their  sides  half 
way  up;  and  they  are  sunk  so  much  under  the  floor  of  the  dyehouse,  that  their  upper 
half  only  is  above  it,  and  is  surrounded  with  a  mass  of  masonry  to  prevent  the  dissipatior 
of  the  heat.  About  3  or  3|  feet  under  the  top  edge  an  iron  ring  is  fixed,  called  the 
champagne  by  the  French,  to  which  a  net  is  attached  in  order  to  suspend  the  stuflfs  out 
of  contact  of  the  sediment  near  the  bottom. 

In  mounting  the  vat  the  following  articles  are  required  :   1.  woad  prepared  by  fermen 
lation,  or  woad  merely  dried,  which  is  better,  because  it  may  be  made  to  ferment  in  the 
▼at,  without  the  risk  of  becoming  putrid,  as  the  former  is  apt  to  do ;  2.  indigo,  previously 
ground  in  a  proper  mill;   3.  madder;   4.  potash;   6.  slaked  quicklime;  6.  bran.    Ir 
France,  weld  is  commonly  used  instead  of  potash. 

The  indigo  mill  is  represented  in  Jigs.  790  and  791.    a  is  a  four-sided  iron  cistern 

790  791 


C J 


4 


c 


IffC 


1,  fl 


4^hrjr>" 


cylindrical  or  rounded  in  the  bottom,  which  rests  upon  gudgeons  in  a  wooden  frame ;  it 
has  an  iron  lid  b,  consisting  of  two  leaves,  between  which  the  rod  c  moves  to  and  fro, 
receiving  a  vibratory  motion  from  the  crank  d.  By  this  construction,  a  frame  e,  which 
is  made  fast  in  the  cistern  by  two  points  e  i,  is  caused  to  vibrate,  and  to  impart  its  swing 
movement  to  six  iron  rollers///,  three  being  on  each  side  of  the  frame,  which  triturate 
the  indigo  mixed  with  water  into  a  fine  paste.  Whenever  the  paste  is  uniformly  ground, 
it  is  drawn  oflT  by  the  stopcock  g,  which  had  been  previously  filled  up  by  a  screwed  plug, 
to  prevent  any  of  the  indigo  from  lodging  in  the  orifice  of  the  cock,  and  thereby  escaping 
the  action  of  the  rollers.    The  cistern  is  nearly  three  "eet  long. 

The  vat  being  filled  with  clear  river  water,  the  fire  is  to  be  kindled,  the  ingredients 
introduced,  and  if  fermented  woad  be  employed,  less  lime  is  needed  than  with  the  merely 
dried  plani.  Meanwhile  the  water  is  to  be  heated  to  the  temperature  of  160®  Fahr., 
and  maintained  at  this  pitch  till  the  deoxydizement  and  solution  of  the  indigo  begin 
to  show  themselves,  which,  according  to  the  state  of  the  constituents,  may  happen  in  12 
hours,  or  not  till  after  several  days.  The  first  characters  of  incipient  solution  are  blue 
bubbles,  called  the  flowers,  which  rise  upon  the  surface,  and  remain  like  a  head  of  soap- 
suds  for  a  considerable  time  before  they  fall ;  then  blue  coppery  shining  veins  appear  with 
a  like  colored  froth.  The  hue  of  the  liquor  now  passes  from  blue  to  green,  and  an 
ammoniacal  odor  begins  to  be  exhaled.  Whenever  the  indigo  is  completely  dissolved, 
an  acetic  smelling  acid  may  be  recognised  in  the  vat,  which  neutralizes  all  the  alkali, 
and  may  occasion  even  an  acid  excess,  which  should  be  saturated  with  quicklime.  The 
lime  for  doing  this  cannot  be  in  general  very  exactly  defined.  When  quicklime  has  been 
added  at  the  beginning  in  sufficient  quantity,  the  liquor  appears  of  a  pale  wine-yellow 
color,  but  if  not,  it  acquires  this  tint  on  the  subsequent  introduction  of  the  lime. 
Experience  has  not  hitherto  decided  in  favor  of  the  one  practice  or  the  other. 

As  soon  as  this  yellow  color  is  formed  in  the  liquor,  and  its  surface  becomes  blue, 
the  vat  is  ready  for  the  dyer,  and  the  more  lime  it  takes  up  without  being  alkaline,  the 
better  is  its  condition.  The  dyeing  power  of  the  vat  may  be  kept  up  during  six  months, 
or  more,  according  to  the  fermentable  property  of  the  woad.  From  time  to  time,  madder 
and  bran  must  be  added  to  it,  to  revive  the  fermentation  of  the  sediment,  along  with  some 
indigo  and  potash,  to  replace  what  may  have  been  abstracted  in  the  progress  of  dyeing. 
The  quantity  of  indigo  must  be  proportional,  of  course,  to  the  depth  or  lightness  of  the 
lints  required. 


INDIGO. 


1051 


During  the  operation  of  this  blue  vat  two  accidents  are  apt  to  occur;  the  first,  whick 
is  the  more  common  one,  is  called  the  throuring  back,  in  French,  the  cuve  rebiiti,  and  in 
German,  the  Scharf  or  Schwartzwerden  (the  becoming  sharp  or  black) ;  the  second  is 
the  pulrefaciion  of  the  ingredients.  Each  is  discoverable  by  its  peculiar  smell,  which  it 
is  impossible  to  describe.  The  first  is  occasioned  by  the  employment  of  too  much  quick- 
lime, whereby  the  liquor  becomes  neutral  or  even  alkaline.  This  fault  may  be  recog- 
nised by  the  fading  of  the  green,  or  by  the  dark  green,  or  nearly  black  appearance  of  the 
liquor ;  and  by  a  dull  blue  froth,  owing  to  a  film  of  lime.  The  remedy  for  a  slight  degree 
of  this  vicious  condition,  is  to  suspend  in  the  liquor  a  quantity  of  bran  tied  up  in  a  bag, 
and  to  leave  it  there  till  the  healthy  state  be  restored.  Should  the  evil  be  more  invete- 
rate, a  decoction  of  woad,  madder,  and  bran  must  be  introduced.  Strong  acids  are  rather 
detrimental.  Sulphate  of  iron  has  been  recommended,  because  its  acid  precipitates  the 
lime,  while  its  oxyde  reduces  the  indigo  to  the  soluble  state. 

The  decomposition  or  putrefaction  of  the  blue  vat  is  an  accident  the  reverse  of  the 
preceding,  arising  from  the  transition  of  the  acetous  into  the  putrid  fermentation,  whereby 
the  dyeing  faculty  is  destroyed.  Such  a  misfortune  can  happen  only  towards  the  com- 
mencement of  working  the  vat,  whilst  the  woad  is  still  powerful,  and  very  little  indigo 
has  been  dissolved.  Whenever  the  vat  is  well  charged  with  indigo,  that  accident  cannot 
easily  supervene.  In  both  of  these  distemperatures  the  elevation  of  the  temperature  of 
the  vat  aggravates  the  evil. 

Dyeing  in  the  blue  vat  is  performed  as  follows  : — 

Wool  is  put  into  a  net,  and  pressed  down  into  the  liquor  with  rods ;  but  cloth  is  smoothly 
stretched  and  suspended  by  hooks  upon  frames,  which  are  steadily  dipped  into  the  va^ 
with  slight  motions  through  the  liquor ;  yarn-hanks  must  be  dipped  and  turned  about  by 
hand.  All  unnecessary  stirring  of  the  liquor  must  however  be  avoided,  lest  the  oxygen 
of  the  atmosphere  be  brought  too  extensively  into  contact  with  the  reduced  indigo,  for 
which  reason  mechanical  agitation  with  rollers  in  the  vat  is  inadmissible.  The  stuffs  to 
be  dyed  take  at  the  first  dip  only  a  feeble  color,  though  the  vat  be  strong,  but  they  must 
be  deepened  to  the  desired  shade  by  successive  immersions  of  fifteen  minutes  or  more  each 
time,  with  intervals  of  exposure  to  the  air,  for  absorption  of  its  oxygen. 

AAer  the  lapse  of  a  certain  time,  if  the  fermentative  power  be  impaired,  which  is  re- 
cognised by  the  dye  stuflfs  losing  more  color  in  a  weak  alkaline  test  ley  than  they  ought, 
the  vat  should  be  used  up  as  far  as  it  will  go,  and  then  the  liquor  should  be  poured  away, 
for  the  indigo  present  is  not  in  a  reduced  state,  but  merely  mixed  mechanically,  and 
therefore  incapable  of  forming  a  chemical  combination  with  textile  fibres.  If  cotton 
goods  previously  treated  with  an  alkaline  ley  are  to  be  dyed  blue,  the  vat  should  contain 
very  little  lime. 

Theory  of  the.  Indigo  vat, — The  large  quantity  of  extractive  matter  in  woad  and 
madder,  as  also  the  sugar,  starch,  and  gluten,  in  the  bran  and  woad,  Avhen  dissolved 
in  warm  water,  soon  occasion  a  fermentation,  with  an  absorption  of  oxygen  from  the 
air,  but  especially  from  the  indigo  of  the  woad,  and  from  that  introduced  in  a  finely 
ground  state.  When  thus  disoxygenaled,  it  becomes  soluble  in  alkaline  menstrua ;  ihe 
red-brown  of  the  indigo  being  dissolved  at  the  same  time.  When  lime  is  added,  the 
indigo-hlue  dissolves,  and  still  more  readily  if  a  little  potash  is  conjoined  with  it;  but 
whatever  indigo-brown  may  have  been  dissolved  by  the  potash,  is  thrown  down  by  the  lime. 
Lime  ix\  too  large  a  quantity,  however,  forms  an  insoluble  combination  with  the  reduced 
indigo,  and  thus  makes  a  portion  of  the  dye  ineffective;  at  the  same  time  it  combines 
with  the  extractive.  In  consequence  of  the  fermentative  action,  carbonic  acid,  acetic 
acid,  and  ammonia  are  disengaged ;  the  first  two  of  which  neutralize  a  portion  of  the  lime, 
and  require  small  quantities  of  this  earth  to  be  added  in  succession  ;  hence  also  a  cou 
siderable  quantity  of  tne  carbonate  of  lime  is  found  as  a  deposite  on  the  sides  and  bottom 
of  the  vat.  In  the  sound  condition  of  the  indigo  vat,  no  free  lime  should  be  perceived, 
but  on  the  contrary  a  free  acid.  Yet  when  the  disengaged  carbonic  and  acetic  acids  sat- 
urate the  lime  completely,  no  indigo  can  remain  at  solution;  therefore  a  sufficient  supply 
of  lime  must  always  be  left  to  dissolve  the  dye,  otherwise  the  indigo  would  fall  down 
and  mix  with  the  extractive  matter  at  the  bottom.  Goods  dyed  in  the  blue  vat  are  occa- 
sionally brightened  by  a  boil  in  a  logwood  bath,  with  a  mordant  of  sulpho-muriate  of  tin, 
or  in  a  bath  of  cudbear. 

Another  mode  of  mounting  the  indigo  vat  without  woad  and  lime,  is  by  means  of  mad- 
der, bran,  and  potash.  The  water  of  the  vat  is  to  be  heated  to  the  temperature  of  122° 
F. ;  atid  for  120  cubic  feet  of  it,  12  pounds  of  indigo,  8  pounds  of  madder,  and  as  much 
bran,  are  to  be  added,  with  24  pounds  of  good  potashes;  at  the  end  of  36  hours,  12 
pounds  more  of  potash  are  introduced,  and  a  third  12  pounds  in  other  12  hours.  In 
the  course  of  72  hours,  all  the  characters  of  the  reduction  and  solution  of  the  indigo 
become  apparent;  at  which  time  the  fermentation  must  be  checked  by  the  addition  of 
quicklime.  The  liquor  has  a  bright  full  color,  with  a  beautiful  rich  froth.  In  feeding 
the  vat  with  indigo,  an  eciual  weight  of  madder  and  a  double  weight  of  potash,  should 


i 


1 


I 


1052 


INDIGO. 


it 


be  added.  The  odor  of  this  vat,  in  its  mild  but  active  stale,  is  necessarily  different  from 
that  of  the  woad  vat,  as  no  ammonia  is  exhaled  in  the  present  case,  and  the  sediment  is 
much  smaller.  The  reduced  indigo  is  held  in  solution  by  the  carbonated  potash,  while 
the  small  addition  of  quicklime  merely  serves  to  precipitate  the  indigo-brown. 

A  potash  vat  dyes  in  about  half  the  time  of  the  ordinary  warm  vat,  and  penetrates 
fine  cloth  much  better;  while  the  goods  thus  dyed  lose  less  color  in  alkaline  and  soap 
solutions.  This  vat  may  moreover  be  kept  with  ease  in  good  condition  for  several 
months;  is  more  readily  mounted;  and  from  the  minute  proportion  of  lime  present,  it 
cannot  impair  the  softness  of  the  woollen  fibres.  It  is  merely  a  little  more  expensive. 
It  is  said  that  cloth  dyed  in  the  potash  indigo  vat,  requires  one  third  less  soap  in  the 
washing  at  the  fulling  mill,  and  does  not  soil  the  hands  after  being  dressed.  At  Elbeuf 
and  Louviers,  in  France,  such  vats  are  much  employed.  Wool,  silk,  cotton,  and  linen, 
may  all  be  dyed  in  them. 

Cold  vats. — The  copperas  or  common  blue  vat  of  this  country  is  so  named  because  the 
indigo  is  reduced  by  means  of  the  protoxyde  of  iron.  This  salt  should  therefore  be  as 
free  as  possible  from  the  red  oxyde,  and  especially  from  any  sulphate  of  copper,  which 
would  re-oxydize  the  indigo.  The  necessary  ingredients  are:  copperas  (green  sulphate 
of  iron),  newly  slaked  quicklime,  finely  ground  indigo,  and  water;  to  which  sometimes 
a  little  potash  or  soda  is  added,  with  a  proportional  diminution  of  the  lime.  The  opera- 
tion is  conducted  in  the  following  way  :  the  indigo,  well  triturated  with  water  or  an  alka- 
line ley,  must  be  mixed  with  hot  water  in  the  preparation  vat,  then  the  requisite  quantity 
of  lime  is  added,  after  which  the  solution  of  copperas  must  be  poured  in  with  stirring. 
Of  this  preparation  vat,  such  a  portion  as  may  be  wanted  is  laded  into  the  dyeing  vat. 
For  one  pound  of  indigo  three  pounds  of  copperas  are  taken,  and  four  pounds  of  lime 
(or  1  of  indigo,  2^  of  copperas,  and  3  of  lime).  If  the  copperas  be  partially  peroxydized, 
somewhat  more  of  it  must  be  used. 

A  vat  containir?  a  considerable  excess  of  lime  is  called  a  sharp  vat,  and  is  not  well 
adapted  for  dyeing.  A  sofi  vat,  on  the  contrary,  is  that  which  contains  too  much  cop 
peras.  In  this  case  the  precipitate  is  apt  to  rise,  and  to  prevent  uniformity  of  tint  in  the 
dyed  goods.  The  sediment  of  the  copperas  vat  consists  of  sulphate  of  lime,  oxyde  of 
iron,  lime  with  indigo  brown,  and  lime  with  indigo  blue,  when  too  much  quicklime  has 
been  employed.  The  clear,  dark  wine  yellow  fluid  contains  indigo  blue  in  a  reduced  state, 
and  indigo  red,  both  combined  with  lime  and  with  the  gluten  of  indigo  dissolved.  After 
using  it  for  some  lime  Ihe  vat  should  be  refreshed  or  fed  with  copperas  and  lime,  upon 
which  occasion  the  sediment  must  first  be  stirred  up,  and  then  allowed  time  to  settle 
again  and  become  clear.  For  obtaining  a  series  of  blue  tints,  a  series  of  vats  of  diiferent 
strengths  is  required. 

Linen  and  cotton  yarn,  before  being  dyed,  should  be  boiled  with  a  weak  alkaline  ley, 
then  put  upon  frames  or  tied  up  in  hanks,  and  after  removing  the  froth  from  the  vat, 
plunged  into  and  moved  gently  through  it.  For  pale  blues,  an  old,  nearly  exhausted 
vat  is  used  ;  but  for  deep  ones,  a  fresh,  nearly  saturated  vat.  Cloth  is  stretched  upon  a 
proper  square  dipping  frame  made  of  wood,  or  preferably  of  iron,  furnished  with  sharp 
hooks  or  points  of  atiachment.  These  frames  are  suspended  by  cords  over  a  pulley,  and 
thus  immersed  and  lifted  out  alternately  at  proper  intervals.  In  the  course  of  8  or  10 
minutes,  the  cloth  is  sufficiently  saturated  with  the  solution  of  indigo,  after  which  it  is 
raised  and  suspended  so  as  to  drain  into  the  vat.  The  number  of  dippings  determines 
the  depth  of  the  shade ;  after  the  last,  the  goods  are  allowed  to  dry,  taken  off  the  frame, 
plunged  into  a  sour  bath  of  very  dilute  sulphuric  or  muriatic  acid,  to  remove  the  adher- 
ing lime,  and  then  well  rinsed  in  running  water.  Instead  of  the  dipping  frames,  some 
dyers  use  a  peculiar  roller  apparatus,  called  gallopers,  similar  to  what  has  been  described 
under  Calico  Printing  ;  particularly  for  pale  blues.  This  cold  vat  is  applicable  to 
cotton,  linen,  and  silk  goods. 

When  white  spots  are  to  appear  upon  a  blue  ground,  resist  pastes  are  to  be  used,  as 
described  under  Calico  Printing. 

The  urine  vat  is  prepared  by  digestion  of  the  ground  indigo  in  wanned  stale  urine, 
which  first  disoxygenates  the  indigo,  and  then  dissolves  it  by  means  of  its  ammonia. 
Madder  and  alum  are  likewise  added,  the  latter  being  of  use  to  moderate  the  fermenta- 
tion. This  vat  was  employed  more  commonly  of  old  than  at  present,  for  the  purpose  of 
dyeing  woollen  and  linen  goods. 

The  mode  of  making  the  China  blue  dye  has  been  described  under  Calico  Printing  ; 
as  well  as  the  pencil  bhie,  or  blue  of  application. 

A  blue  dye  may  likewise  be  given  by  a  solution  of  indigo  in  sulphuric  acid.  This  pro- 
cess was  discovered  by  Barth,  at  Grossenhayn,  in  Saxony,  about  the  year  1740,  and  is 
hence  called  the  Saxon  blue  dye.  The  chemical  nature  of  this  process  has  been  already 
fully  explained.  If  the  smoking  sulphuric  acid  be  employed,  from  4  to  5  parts  are  suffi- 
cient for  1  of  indigo ;  but  if  oil  of  vitriol,  from  7  tc  «  parts.  The  acid  is  to  be  poured 
into  an  earthenware  pan,  which  in  summer  must  be  placed  in  a  tub  of  cold  water,  to  pre- 


INDIGO. 


1053 


vent  It  getting  hot,  and  the  indigo,  in  fine  powder,  is  to  be  added,  with  careful  stirring, 
in  small  successive  portions.  If  it  becomes  heated,  a  part  of  the  indigo  is  decom- 
posed, with  the  disengagement  of  sulphurous  acid  gas,  and  indigo  green  is  pnduced. 
Whenever  all  the  indigo  has  been  dissolved,  the  vessel  must  be  covered  up,  allowed  to 
stand  for  48  hours,  and  then  diluted  with  twice  its  weight  of  clear  river  water. 

The  undiluted  mass  has  a  black  bJue  color,  is  opaque,  thick,  attracts  water  fiom  the 
air,  and  is  called  indigo  composition,  or  chemic  blue.  It  must  be  prepared  beforehand, 
and  kept  in  store.  In  this  solution,  besides  the  cerulin,  there  are  also  indigo  red,  indigo- 
brown,  and  gluten,  by  which  admixture  the  pure  blue  of  the  dye  is  rendered  foul,  as- 
suming a  brown  or  a  green  cast.  To  remove  these  contaminations,  wool  is  had  recourse 
to.  This  is  plunged  into  the  indigo  previously  diffused  through  a  considerable  body  of 
water,  brought  to  a  boiling  heat  in  a  copper  kettle,  and  then  allowed  to  macerate  as  it 
cools  for  24  hours.  The  wool  takes  a  dark  blue  dye  by  absorbing  the  indigo-blue  sulphate 
and  hyposulphite,  while  at  the  same  time  the  liquor  becomes  greenish  blue  ;  and  if  the 
wool  be  left  longer  immersed,  it  becomes  of  a  dirty  yellow.  It  must  therefore  be  takeii 
out,  drained,  washed  in  running  water  till  this  runs  oflf  colorless,  and  without  an  acid 
taste.  It  must  next  be  put  into  a  copper  full  of  water,  containing  one  or  two  per  cent, 
of  carbonate  of  potash,  soda,  or  ammonia  (to  about  one  third  the  weight  of  the  indigo), 
and  subjected  to  a  boiling  heat  for  a  quarter  of  an  hour.  The  blue  salts  forsake  the 
wool,  leaving  it  of  a  dirty  red-brown,  and  dye  the  water  blue.  The  wool  is  in  fact  dyed 
with  the  indigo-red,  which  is  hardly  soluble  in  alkali.  The  blue  liquor  may  now  be  em- 
ployed as  a  fine  dye,  possessed  of  superior  tone  and  lustre.  It  is  called  distilled  blue  and 
soluble  blue.  Sulphuric  acid  throws  down  from  it  the  small  quantity  of  indigo-red  which 
had  been  held  in  solution  by  the  alkali. 

When  wool  is  to  be  dyed  with  this  sulphate  of  indigo-blue,  it  must  be  first  boiled  in 
alum,  then  treated  with  the  blue  liquor,  and  thus  several  times  alternately,  in  order  to 
produce  a  uniform  blue  color.  Too  long  continuance  of  boiling  is  injurious  to  the 
beauty  of  the  dye.  In  this  operation  the  woollen  fibres  get  impregnated  with  the  indigo- 
blue  sulphate  of  alumina. 

With  sulphate  of  indigo,  not  only  blues  of  every  shade  are  dyed,  but  also  green,  olive, 
gray,  as  also  a  fast  ground  to  logwood  blues ;  for  the  latter  purpose  the  preparatory  boil 
is  given  with  alum,  tartar,  sulphates  of  copper  and  iron,  and  the  blue  solution ;  after 
which  the  goods  are  dyed  up  with  a  logwood  bath  containing  a  little  potash. 


Table 

of  Stocks,  Deliveries,  Imports,  &c.,  through  the  course  of  16  Yeara. 

Arrived 
in  19  moot  lis. 

Crop  of 

Prices  31»t  December. 

Stock  31st 
December. 

Delivered 
19  Months. 

Bt^n^il  in 
course  of 
Sbipinent. 

B.Dgal.* 

Madra.<i, 

Totil. 

Good  and  Fine 

Middling  and 
Good 

Ordinary 

Manilla,  &c. 

P.  V. 

Consuming. 

Consuming. 

1836 

22..*W9 

29.318 

21,829 

1.612 

23,501 

matinds. 
115,500 

per  lb. 
1    0@8    0 

l>er  lb. 
6    0®6    e 

per  lb. 
6    4^5  10 
5    6^  6    • 

1831 

25,969 

1H.544 

19,409 

9,162 

22,111 

113,600 

1    4  "  8    9 

6    3  "  6    9 

183S 

21,16) 

28,488 

21,610 

2,812 

23,688 

8.1000 

8    6  "  9    0 

6    9  "  1    3 

6  10  "  6    6 

1839 

15,250 

23,211 

13,8^2 

3410 

11  352 

liS.OuO 

8    8  "  9    0 

6    0  "  1    0 

6    0  "  5    9 

1840 

16,344 

25,811 

22,823 

4.082 

26.9  5 

l-i3  0O0 

1     6  "  8    3 

6    3  "  6    3 

4    6  «  5    0 

1-^41 

16,418 

26.599 

2. ',681 

4.046 

26.133 

16. ,000 

6    0  "  6  10 

3    4  "  4    0 

9    9  ♦   3    3 

1849 

'.il,»21 

91.820 

26,594 

6.rt15 

33,269 

18,900 

1     9  •'  8    3 

5    0  '•  5    9 

4    3  "  4    9 

1843 

9l,:81 

99.954 

16,920 

5888 

92  808 

lU.OOO 

5    0  '•  5    8 

3    6  "  3  10 

9  10  •'  3    4 

1844 

25,<15 

32,253 

28.228 

8,219 

36  441 

143  500 

4  10  "  5    6 

3    8  "  3  IL' 

;:    9  "  3    6 

1845 

33.512 

99.968 

25,458 

12,041 

31  ,.'.05 

191,800 

4  10  "  5    8 

3    3  "  3    6 

9  10  "  3    3 

1846 

3;M18 

28.431 

19,4:;8 

8  659 

28,09  J 

101  300 

6    0  "  6    0 

3    8  "  4    0 

3    9  "  3    6 

1841 

31,909 

31.428 

19.516 

9,516 

29,152 

1O1.200 

4    6  "  6    3 

2  10  "  3    3 

9    4  "  9    8 

1848 

28.962 

215t.3 

21,119 

3.504 

24. 62.5 

126100 

4    3  "  5    3 

9  10  "  3    3 

fi    6  •»  9    9 

1849 

29  036 

39.113 

97,464 

5383 

3 -■841 

122,(H.0 

4     6  "  6    4 

3    6  "  3    9 

3    3  "  3    6 

18.'>0 

21.2<"5 

98.69.) 

20,051 

6,809 

96,859 

11 2,' too 

6    0  '•  1     0 

5    9  "  5    6 

4    1  "  5    0 

1861 

30,33* 

99,241 

92,612 

9,196 

32.368 

122,OoO 

4    8  "  5    9 

3    1  "  3  11 

3    1  "  8    « 

Stock  of  E.  I.  Indigo,  in  the  chief  European  Ports,  at  the  end  of  the  following  Years. 


Yearf. 

Rotter- 
dam,* 

Amster- 
dam.* 

Antwerp. 

Ham- 
burgh, 

St. 
Peters- 
burgh. 

Trieste. 

Genoa. 

Bremen. 

Fiance. 

London 

and 

Liverpool. 

ToUl 
Stock 

in 
Europe. 

I84S 
1844 
1<45 
184H 
1S41 
1848 
1849 
1860 
1861 

cllfStS. 

1,500 
664 
5.S0 
331 
93^ 
1049 
695 
395 
80 

cliests. 
1,600 
1,342 
651) 
499 
560 
531 
828 
851 
320 

chests, 
loo 

no 

100 
100 

60 

60 
100 
160 
loO 

chests. 
255 
850 
320 
916 
160 
450 
550 
840 
960 

chests. 
1,701 
1600 
9,011 
1,389 
1918 
9,000 
1.655 
l,4fi0 
1,681 

chests. 
150 
949 
980 
400 
930 
900 
160 
150 
60 

chests. 

149 

9o6 

9.6 

165 

13) 

120 

101 
40 
60 

chests. 
20 
10 
60 
50 
9) 
48 
90 
60 
90 

chests. 

6.466 

1,:i9 

10,485 

10  615 

ll.lil 

1.4rt9 

4,501 

5,311 

6,953 

chests. 
9J.381 
96  915 
34.519 
33  918 
32  809 
29,419 
29.240 
21.9  5 
30,45i 

ch>-8t«. 
3J.3>8 
39  361 
4't.l93 
41.141 
419:^5 
41316 
31146 
:6  989 
38,969 

Imported    for  home    consumption,  in  1850,  7,893,984   pounds;    in  1861,  10,073,728 
pountis. 


1 


i 


!: 


1054 


4 


INDIGO. 


LAKDix<2a,  Dklive&ies,  and  Stocks  of  R  L  iKDiaa 


In  Dec          1861 

1850 
1849 
In  18  months  1851 
1850 
1849 
1848 
1847 
1846 
1846 
1844 
1843 

Ludad. 

Delivered. 

Stock  1st  Janiuu7,  1869. 

B«ngal. 

MfldrM, 

Total. 

Home 

CoDSump- 
tion. 

Export. 

Total. 

Ben^. 

Madras, 
Ac. 

ToUl. 

171 
673 

22,572 
20,057 

273 
131 

9,196 
6,802 

460 
1,404 

478 
32,363 
26,859 
32.799 
21,623 
29.263 
28,102 
87,461 
36.808 
22,8U8 

619 

399 

433 

8,344 

8,551 

9,209 

10.468 

9.010 

10,546 

10,666 

11.664 

8,263 

1,134 

418 

1.261 

2o,8it1 
20,139 
23,.S«4 
11,095 
21.418 
11,886 
19,302 
90.589 
14,101 

1,813 
811 

1,694 
29.241 
28,690 
33,773 
27,.S63 
30,428 
28,431 
29  968 
32,-.!  53 
22,954 

26,023 
23.089 
24,989 
23,132 
24,396 
25,333 
26,336 
22,823 

4,304 
4116 
4,041 
6,2.30 
7,507 
1.845 
1,111 
3,152 

—  chests. 
_       •» 

u 

30.332    " 
21.205    " 
29  0  6    " 
2>i,962    » 
31,902    " 
?,3,118    " 
33^2    " 
25.975    " 
21,181    " 

Indigo  from  Spanish  South  America  has  formed  a  large  feature  in  our  importations  of 
1851.  The  landings  amount  to  7,291  serons,  being  4,111  more  than  the  greatest  quantity 
ever  before  received  in  one  year,  and  5,428  more  than  the  average  importations  of  the 
last  ten  years. 

The  deliveries  have  been  still  greater  ;  7,887  serons — equivalent  to  about  3,900  chests 
of  East  Indian  production.  The  parcels,  uniformly  brought  to  auction  upon  arrival, 
have  met  with  very  general  attention.  The  value  may  be  considered  relatively  as  high 
as  Bengal. 

Tliat  such  quantities  of  this  indigo  were  directed  to  this  country  is  not  the  result  of 
increased  cultivation,  but  of  the  high  prices  current  in  1850,  offering  a  better  market  than 
those  of  the  United  States  or  the  Mediterranean,  the  usual  destination  direct  from  the 
producing  countries- 

Landings,  Delxveries,  and  Stocks  of  Spanish  Indigo. 


In  December 

1851 

Tended. 

Delivered. 

Stock  Ist  Jannary. 

13  serons 

207  serons 

—  serons 

1850 

316      « 

127      " 

__^        « 

In  12  months 

1851 

7,291      " 

7,887     * 

403      ♦♦ 

1850 

3,080      " 

2,478      * 

999      " 

1849 

2,352      " 

3,027      •• 

397      " 

1848 

1,153      " 

1,967      • 

965      " 

1847 

2,045      " 

1,273      ' 

1,779      " 

1846 

1,265      « 

1,414      • 

948      " 

1845 

1,083      " 

1,047      ' 

1,097      " 

1844 

1,132      " 

1,095      ' 

889      " 

1843 

2,480      " 

2,641      ' 

891      " 

1842 

1,968      " 

1,850      " 

1,062      " 

INK. 


1055 


Prices. — Bengal,  fine  blue,  5*.  lOd.  to  6«.  per  lb, ;  fine  purple  and  violet,  5a.  2d.  to  5«. 
9d. ;  fine  red  violet,  5s.  Id.  to  5s,  ^d. ;  good  purple  and  violet,  4*.  9>d,  to  5s. ;  middling 
violet,  4s.  6c?.  to  4».  8d ;  middling  defective,  4s.  to  4s.  hd.  Consuming,  fine,  4s.  to  4s.  bd. ; 
middling  and  good,  3s.  7ct  to  3s.  llct ;  ordinary,  3s.  \d.  to  3s.  6c?.;  ordinary  and  trash, 
2s.  Zd.  to  2s.  lOd. 

Oude,  middling  and  good,  2s.  6<?.  to  3s. ;  ordinary,  2s.  2d.  to  2s.  hd. 

Madras,  good  and  fine,  4s.  to  4s.  6rf. ;  middling,  3s,  to  3s.  9ct ;  ordinary,  Is.  ^d.  to 
2s.  9rf. 

Kurpah,  fine,  5s.  to  6s.  %d. ;  good,  4s.  to  4s.  9i. ;  middling,  3s.  Zd.  to  3s.  llci ;  ordinary, 
2s.  Zd.  to  2s.  \Qd. ;  sweepings.  Is.  3c?.  to  Is.  &d. 

Spanish  :  Guatemala,  good  and  fine,  As.  4d.  to  5s. ;  middling,  3s.  6c?.  to  4s.  2d. ;  ordinary, 
2s.  6d.  to  3s.  3c?. 

Caracca,  good,  3s.  8d.  to  4s.  6c?. ;  ordinary,  2s.  &d.  to  3s.  &d. 

Lay  ton,  Hulbert  <fc  Co.'s  Circular ^  *lth  Jan.  1852. 

*  Inclading  Coastwise  from  LiverpooL 


INDIGO,  tested  and  valued.  Rub  one  gramme  of  indigo  to  a  fine  powder  in  a  porce- 
lain mortar,  pour  over  it  10  grammes  of  fuming  sulphuric  acid,  cover  it  and  stir  occasion- 
ally from  6  to  8  hours.  Pour  the  mixture  into  an  evaporating  dish,  containing  2  lbs.  of 
water,  and  add  50  grammes  of  muriatic  acid,  and  heat  the  whole  to  boiling,  replacing  tho 
water  lost  in  vapour. 

Dissolve  one-fourth  of  a  gramme  of  chlorate  of  potash  in  100  grammes  of  water,  in  a 
graduated  glass  tube  capable  of  holding  100  cubic  centimetres  of  water.  This  quantity 
of  salt  suffices  even  for  the  very  best  indigo.  This  test  liquid  is  to  be  added  to  the 
boiling  hot  indigo  solution  in  question  by  degrees,  and  the  quantity  of  it  is  noted, 
which  is  required  to  make  the  colour  pass  from  blue  into  green,  and  finally  to  brownish 
red.  By  comparative  results  with  other  indigos,  and  the  same  test,  their  relative  value 
is  given. 

INDIAN  RUBBER,  is  the  vulgar  name  of  caoutchouc  in  this  country. 

INDUSTRY.    See  Manufacturing  Industry. 

INK  (EncrCj  Fr. ;  Tinte,  Germ.)  is  a  colored  liquid  for  writing  on  paper,  parchment, 
linen,  &c.  with  a  pen. 

Black  ink. — Nutgalls,  sulphate  of  iron,  and  gum,  are  the  only  substances  truly  useful 
in  the  preparation  of  ordinary  ink ;  the  other  things  often  added  merely  modify  the  shade, 
and  considerably  diminish  the  cost  to  the  manufacturer  upon  the  great  scale.  Many  of 
these  inks  contain  little  gallic  aeid,  or  tannin,  and  are  therefore  of  inferior  quality.  To 
make  12  gallons  of  ink,  we  may  take — 

12  pounds  of  nutgalls, 
6  pounds  of  green  sulphate  of  iron, 
5  pounds  of  gum  Senegal, 
12  gallons  of  water. 

The  bruised  nutgalls  are  to  be  put  into  a  cylindrical  copper,  of  a  depth  equal  to  its 
diameter,  and  boiled,  during  three  hours,  with  three  fourths  of  the  above  quantity  of 
water,  taking  care  to  add  fresh  water  to  replace  what  is  lost  by  evaporation.  The 
decoction  is  to  be  emptied  into  a  tub,  allowed  to  settle,  and  the  clear  liquor  being 
drawn  off,  the  lees  are  to  be  drained.  Some  recommend  the  addition  of  a  little  bullock's 
blood  or  while  of  eggy  to  remove  a  part  of  the  tannin.  But  this  abstraction  tends  to  lessen 
the  product,  and  will  seldom  be  practised  by  the  manufacturer  intent  upon  a  large  return 
for  his  capital.  The  gum  is  to  be  dissolved  in  a  small  quantity  of  hot  water,  and  the 
mucilage  thus  formed,  being  filtered,  is  added  to  the  clear  decoction.  The  sulphate  of 
iron  must  likewise  be  separately  dissolved,  and  well  mixed  with  the  above.  The  color 
darkens  by  degrees,  in  consequence  of  the  peroxydizement  of  the  iron,  on  exposing  the 
ink  to  the  action  of  the  air.  But  ink  affords  a  more  durable  writing  when  used  in  the 
pale  state,  because  its  particles  are  then  finer,  and  penetrate  the  paper  more  intimately. 
When  ink  consists  chiefly  of  tannate  of  peroxyde  of  iron,  however  black,  it  is  merely 
superficial,  and  is  easily  erased  or  efiaced.  Therefore,  whenever  the  liquid  made  by  the 
above  prescription  has  acquired  a  moderately  deep  tint,  it  should  be  drawn  off  clear  into 
bottles,  and  well  corked  up.  Some  ink-makers  allow  it  to  mould  a  little  in  the  casks 
before  bottling,  and  suppose  that  it  will  thereby  be  not  so  liable  to  become  mouldy  in  the 
bottles.  A  few  bruised  cloves,  or  other  aromatic  perfume,  added  to  ink,  is  said  to  pre- 
vent the  formation  of  mouldiness,  which  is  produced  by  the  ova  of  infusoria  animalcules. 
I  prefer  digesting  the  galls  to  boiling  them. 

The  operation  may  be  abridged,  by  peroxydizing  the  copperas  beforehand,  by  moderate 
calcination  in  an  open  vessel ;  but,  for  the  reasons  above  assigned,  ink  made  with  such  a 
sulphate  of  iron,  however  agreeable  to  the  ignorant,  when  made  to  shine  with  gum  and 
sugar,  under  the  name  of  japan  ink,  is  neither  the  most  durable  nor.  the  most  pleasant  to 
write  with. 

From  the  comparatively  high  price  of  gall-nuts,  sumach,  logwood,  and  even 
oak  bark,  are  too  frequently  substituted,  to  a  considerable  degree,  in  the  manufacture 
of  ink. 

The  ink  made  by  the  prescription  given  above,  is  much  more  rich  and  powerful  than 
many  of  the  inks  commonly  sold.  To  bring  it  to  their  standard,  a  half  more  water  may 
safely  be  added,  or  even  20  gallons  of  tolerable  ink  may  be  made  from  that  weight  of 
materials,  as  I  have  ascertained. 

Sumach  and  logwood  admit  of  only  about  one  half  of  the  copperas  that  galls  will  take 
to  bring  out  the  maximum  amount  of  black  dye. 

Chaptal  gives  a  prescription  in  his  Chimie  appliquee  aux  arts,  which,  like  many  other 
things  in  that  book,  are  published  with  very  little  knowledge  and  discrimination.  He 
uses  logwood  and  sulphate  of  copper,  in  addition  to  the  galls  and  sulphate  of  iron ;  a  (>er- 
nicious  combination,  productive  of  a  spurious  fugitive  black,  and  a  liquor  corrosive  of 
pens.     It  is,  in  fact,  a  modification  of  the  vile  dye  of  the  hatters. 

Lewis,  who  made  exact  experiments  on  inks,  assigned  the  proportion  of  3  parts  of  galla 


1056 


INK. 


to  1  of  sulphate  of  iron,  which,  with  average  galls,  will  answer  very  well ;  but  gooa  galls 
will  ad<nit  of  more  copperas. 

Gold  ink  is  made  by  grinding  upon  a  porphyry  slab,  with  a  mv.iier,  gold  leaves  along 
with  white  honey,  till  they  be  reduced  to  the  finest  possible  division.  The  paste  is  then 
collected  upon  the  edge  of  a  knife  or  spatula,  put  into  a  large  glass,  and  diffused  thrc4gh 
water.  The  gold  by  gravity  soon  falls  to  the  bottom,  while  the  honey  dissolves  in  the 
water,  wnich  must  be  decanted  off.  The  sediment  is  to  be  repeatedly  washed  till  entirely 
freed  from  the  honey.  The  powder,  when  dried,  is  very  brilliant,  and  when  to  be  used 
as  an  ink,  may  be  mixed  up  with  a  little  gum  water.  After  the  writing  becomes  dry,  it 
should  be  burnished  with  a  wolPs  tooth. 

Sitter  ink  is  prepared  in  the  same  manner. 

Indelible  ink.— A  very  good  ink,  capable  of  resisting  chlorine,  oxalic  acid,  and  ablution 
with  a  hair  pencil  or  sponge,  may  be  made  by  mixing  some  of  the  ink  made  by  the  pre- 
ceding prescription,  with  a  little  genuine  China  ink.  It  writes  well.  Many  other  form- 
ulae have  been  given  for  indelible  inks,  but  they  are  all  inferior  in  simplicity  and  useful- 
ness to  the  one  now  prescribed.  Solution  of  nitrate  of  silver  thickened  with  gum,  and 
written  with  upon  linen  or  cotton  cloth,  previously  imbued  with  a  solution  of  soda,  and 
dried,  is  the  ordinary  permanent  ink  of  the  shops.  Before  the  cloths  are  washed,  the 
writing  should  be  exposed  to  the  sun-beam,  or  to  bright  daylight,  which  blackens  and  fixes 
the  oxyde  of  silver.     It  is  easily  discharged  by  chlorine  and  ammonia. 

A  good  permanent  ink  may  be  made  by  mixing  a  strong  solution  of  cliloride  of  platinum 
with  a  little  potash  sugar,  and  gum  to  thicken.  The  writing  made  therewith  should  be 
passed  over  with  a  hot  smoothing  iron,  to  fix  it. 

Red  ink. — This  ink  may  be  made  by  infusing,  for  3  or  4  days  in  weak  vinegar, 
Brazil  wood  chipped  into  small  pieces ;  the  infusion  may  be  then  boiled  upon  the  wood 
for  an  hour,  strained,  and  thickened  slightly  with  gum  arable  and  sugar.  A  little 
alum  improves  the  color.  A  decoction  of  cochineal  with  a  little  water  of  ammonia, 
forms  a  more  beautiful  red  ink,  but  it  is  fugitive.  An  extemporaneous  red  ink  of  the 
same  kind  may  be  made  by  dissolving  carmine  in  weak  water  of  ammonia,  and  adding  a 
little  mucilage. 

Green  ink. — According  to  Elaproth,  a  fine  ink  of  this  color  may  be  prepared  by  boiling 
a  mixture  of  two  parts  of  verdigris  in  eight  parts  of  water,  with  one  of  cream  of  tartai 
till  the  total  bulk  be  reduced  one  half.      The  solution  must  be  then  passed  through  ^ 
cloth,  cooled,  and  bottled  for  use. 

Yellow  ink  is  made  by  dissolving  3  parts  of  alum  in  100  of  water,  adding  25  parts  of 
Persian  or  Avignon  berries  bruised,  boiling  the  mixture  for  an  hour,  straining  the  liquor, 
and  dissolving  in  it  4  parts  of  gum  arable.  A  solution  of  gamboge  in  water  forms  acoo- 
venient  yellow  ink. 

By  examining  the  different  dye-stuffs,  and  considering  the  processes  used  in  dyeing  with 
them,  a  variety  of  colored  inks  may  be  made. 

China  ink. — Proust  says,  that  lamp-black  purified  by  potash  ley,  when  mixed  with 
a  solution  of  glue,  and  dried,  formed  an  ink  which  was  preferred  by  artists  to  that  of 
China.      M.  Merimee,  in  his  interesting  treatise,  entitled,  De  la  peinture  H  Vhuile,  says, 
that  the  Chinese  do  not  use  glue  in  the  fabrication  of  their  ink,  but  that  they  add 
vegetable  juices,  which    render    it   more   brilliant    and   more    indelible   upon    paper. 
When  the  best  lamp-black  is  levigated  with  the  purest  gelatine  or  solution  of  glue,  it 
^orms,  no  doubt,  an  ink  of  a  good  color,  but  wants  the  shining  fracture,  and  is  not  so 
permanent  on  paper  as  good   China  ink  ;  and  it  stiffens  in  cold  weather  into  a  tremulous 
jelly.      Glue  may  be  deprived  of  the  gelatinizing  property  by  boiling  it  for  a  long  time, 
or  subjecting  it  to  a  high  heat  in  a  Papin's  digester;  but  as  ammonia  is  apt  to  be  gene- 
rated in  this  way,  M.  Merimee  recommends  starch  gum  made  by  sulphuric  acid  (British 
gum)  to  be  used  in  preference  to  glue.      He  gives,  however,  the  following  directions  foi 
preparing  this  ink  with  glue.     Into  a  solution  of  glue  he  pours  a  concentrated  solution 
of  gall-nuts,  which  occasions  an  elastic  resinous-looking  precipitate.      He  washes  this 
matter  with  hot  water,  and  dissolves  it  in  a  spare  s.  ution  of  clarified  glue.     He  filters 
anew,  and  concentrates  it  to  the  proper  degree  for  being  incorporated  with  the  purified 
«mp-black.     The  astringent  principle  in  vegetables  does  not  precipitate  gelatine  when 
its  acid  is  saturated,  as  is  done  by  boiling  the  nutgalls  with  liroewater  or  magnesia.   The 
first^mode  of  making  the  ink  is  to  be  preferred.     The  lamp-black  is  said  to  be  made  in 
China,  by  collecting  the  smoke  of  the  oil  of  sesame.  A  little  camphor  (about  2  per  cent.) 
1ms  been  detected  in  the  ink  of  China,  and  is  supposed  to  improve  it.     Infusion  of  galls 
renders  the  ink  permanent  on  paper. 

Sympathetic  ink.     The  best  is  a  solution  of  muriate  of  cobalt. 

Printer's  ink.     See  this  article. 

By  decomposing  vanadate  of  ammonia  with  infusion  of  galls,  a  liquid  is  obtained 
of  a  perfectly  black  hue,  which  flows  freely  from  the  pen,  is  rendered  blue  by  acids,  is 
insoluble  in  dilute  alkalis,  and  resists  the  action  of  chlorine.    Whenever  the  metal  vana 


INK. 


1057 


dium  shall  become  more  abundant,  as  it  probably  may  ere  long,  we  shall  possess  the 
means  of  making  an  ink,  at  a  moderate  price,  much  superior  to  the  tannate  and  gallate 
of  iron. 

To  prepare  the  above  vanadic  salt  cheaply,  the  cinder  or  hammerschlag  obtained 
from  the  iron  made  at  Ekersholm,  in  Sweden,  or  other  iron  which  contains  vana- 
dium, being  reduced  to  a  fine  powder,  is  to  be  mixed  with  two  thirds  of  its  weight 
of  nitre,  and  one  third  of  effloresced  soda.  The  mixture  is  to  be  ignited  in  a  crucible ; 
cooled  and  lixiviated,  whereby  solutions  of  the  vanadates  of  potash  and  soda  are  obtained, 
not  pure,  indeed,  but  suflSciently  so  for  being  decomposed,  by  means  of  sal  ammoniac, 
into  a  vanadate  of  ammonia.  This  being  rendered  nearly  neutral  with  any  acid,  con- 
stitutes an  excellent  indelible  ink. 

Ink,  indelible,  may  be  prepared  by  adding  lamp-black  and  Indigo  to  a  solution  of  the 
gluten  of  wheat  in  acetic  acid.  This  ink  is  of  a  beautiful  black  colour,  at  the  same  time 
cheap,  and  cannot  be  removed  by  water,  chlorine,  or  dilute  acids.  M.  Herberger  gives 
the  following  directions  for  its  preparation  :  —  Wheat-gluten  is  carefully  freed  from  the 
starch,  and  then  dissolved  in  a  little  weak  acetic  acid ;  the  liquid  is  now  mixed  with  so 
much  rain  water  that  the  solution  has  about  the  strength  of  wine  vinegar,  i.  e.  neutra- 
lizes ^  of  its  weight  of  carbonate  of  soda.  10  grs.  of  the  best  lamp-black  and  2  grs.  of 
indigo  are  mixed  with  4  ozs.  of  the  solution  of  gluten  and  a  little  oil  of  cloves  added* 
This  ink  may  be  employed  for  marking  linen,  as  it  does  not  resist  mechanical  force. 

Ink,  indelible,  of  Dr.  Traill,  is  essentially  the  same  as  the  above. 

French  indelible  ink  consists  of  Indian  ink  difi^used  through  dilute  muriatic  acid,  for 
writing  with  quills,  and  through  weak  potash  lye  for  writing  with  steel  pens. 

Ink,  blue.  Mr.  Stephen's  patent  blue  ink  is  made  by  dissolving  Prussian  blue  in  a 
solution  of  oxalic  acid.    The  blue  should  be  washed  in  dilute  muriatic  acid. 

M.  Hornung  has  given  the  following,  as  the  best  formula  for  blue  ink :  — 

Mix  4  parts  of  perchloride  of  iron,  in  solution,  with  750  parts  of  water,  then  add  4 
parts  of  c^'anide  of  potassium  dissolved  in  a  little  water ;  collect  the  precipitate  formed, 
wash  it  with  several  additions  of  water,  allow  it  to  drain  until  it  weighs  about  200  parts ; 
add  to  this  one  part  of  oxalic  acid,  and  promote  the  solution  of  the  cyanide  by  shaking 
the  bottle  containing  the  mixture.  The  addition  of  gum  and  sugar  is  useless,  and  even 
appears  to  exercise  a  prejudicial  effect  on  the  beauty  of  the  ink.  It  may  be  kept  with- 
out any  addition  for  a  long  time. 

Rev.  Mr.  Readers  inks. — A  series  of  writing  inks  of  a  new  composition  have,  been 
made  the  subject  of  a  patent  by  the  Rev.  J.  B.  Reade,  F.  R.  S.,  and  they  seem  to 
deserve  public  patronage.  They  resist  equally  acids  and  alkalis,  and  are  well  adapted 
to  metallic  pens.  His  inks  for  marking  linen  are  not  acted  upon  by  cyanide  of  potas- 
sium or  chloride  of  lime.  His  process  for  obtaining  a  soluble  Prussian  blue  is  new  to 
the  chemical  world,  and  inclines  to  raise  a  doubt  as  to  the  elementary  nature  of  iodine. 
In  the  course  of  his  researches,  he  has  discovered  two  new  salts  of  gold,  which  he  has 
named  ammonia-iodide,  and  ammonia-periodide,  of  gold.     His  specification  runs  thus :  — 

Istly.  I  manufacture  in  manner  following,  a  blue  writing  ink,  which  is  wholly  free 
from  acid,  and  therefore  well  adapted  for  use  with  steel  pens.  I  first  obtain  a  solution  of 
iodide  of  iron  by  the  process  ordinarily  followed  for  that  purpose,  and  then  dissolve 
therein  half  the  weight  of  iodine  already  employed.  I  next  pour  this  mixture  into  a 
semi -saturated  solution  of  yellow  prussiate  of  potash,  employing  a  weight  of  this  salt 
nearly  equal  to  the  whole  weight  of  iodine  use^n  the  above  iodine  solution.  A  decom- 
position of  the  materials,  thus  brought  togethei^immcdiately  takes  place,  when  the 
cyanogen  (of  the  prussiate  of  potash)  and  iron  combine,  and  are  precipitated  in  a  solid 
form,  and  the  potassium  (of  the  prussiate)  and  iodine  combine  to  form  a  neutral  iodide 
of  potassium,  which  remains  in  solution  with  a  little  excess  of  iodide  of  iron.  I  next 
filter  and  wash  the  solid  precipitate  of  cyanogen  and  iron  (which  is  soluble  Prussian 
blue),  and  finally  dissolve  it  in  water,  which  forms  the  blue  ink  required.  In  this  pro- 
cess, it  will  be  observed  that  neither  any  acid  nor  persalt  of  iron  is  employed,  as  is  usual 
in  the  formation  of  Prussian  blue. 

I  was  led  to  these  results  by  a  microscopical  examination  of  the  metallic  colours  in 
salts  of  the  ashes  of  plants.  I  employed  iron  and  iodine  to  produce  the  same  effects  in 
pure  salts ;  and  in  the  course  of  my  experiments,  I  ascertained  that  these  two  substances 
(iron  and  iodine)  have  so  great  an  affinity  for  each  other,  that  when  placed  together 
without  any  water,  or  when  rubbed  together,  they  very  speedily  form  a  liquid  contain- 
ing an  excess  of  iodine  in  solution,  which,  being  added  to  a  solution  of  prussiate  of 
potash,  gives  the  compound  of  cyanogen  and  iron,  or  soluble  Prussian  blue,  which  has 
been  just  described.  The  addition  of  water  alters  the  character  of  this  iodine  solution  ; 
without  water,  it  turns  litmus  paper  green,  and  with  water  it  has  the  usual  acid 
reaction,  thus  apparently  confirming  Davy's  original  doubt  as  to  the  elementiU'y 
character  of  iodine. 

67 


H 


) 


1058 


INK. 


2ndly.  I  form  a  neutral  iodide  of  potassium,  of  great  purity,  and  wholly  free  from 
alkaline  reaction,  in  manner  following:  I  take  the  solution  which  remained  over  from 
the  process  first  described,  after  the  Prussian  blue  had  been  precipitated,  which  solution 
consisted,  as  before  stated,  of  a  neutral  iodide  of  potassium,  with  iodide  of  iron  m 
excess  ;  and  I  get  rid  of  that  excess  by  the  well  known  processes  of  fusion  and  crystal- 
lization. The  result  is  an  iodide  of  potassium,  which  is  as  pure  as  when  iodine  and 
potassium  are  made  to  act  directly  on  one  another,  and  is  perfectly  free  from  the  alkahne 
reaction  on  turmeric  paper,  which  invariably  characterizes  the  most  careful  preparations 
of  this  salt  when  carbonate  of  potassa  is  employed  (as  usual)  in  its  manufacture.  It  is 
also  much  less  deliquescent  than  the  ordinary  iodide  of  potassium  of  commerce,  and,  on 
account  of  its  great  purity,  much  to  be  preferred  in  medicinal  preparations. 

Srdly.  I  manufacture  a  blue  ink  of  peculiar  intensity,  and,  therefore,  particularly 
suitable  for  printing  purposes,  by  using  the  same  materials,  and  manipulating  them  in 
the  same  way  as  first  described,  with  the  exception  that  for  the  iodine  wherever  it  is 
used,  I  substitute  bromine,  and  rub  up  the  precipitate  in  oil. 

4thly.  I  form  a  bromide  of  potassium  of  great  purity,  and  wholly  free  from  alkaline 
reaction,  by  treating  the  bromide  of  potassium,  which  remains  over  in  a  state  of  solution 
from  the  process  last  before  described,  in  the  same  way  as  the  iodide  of  potassium 
solution  is  directed  to  be  used  under  the  second  head  of  this  specification. 

Sthly.  I  manufacture  a  very  superior  black  writing  ink,  by  adding  to  gall  ink  of  a 
good  quality  soluble  Prussian  blue,  described  under  the  first  head  of  this  specification. 
The  addition  of  this  Prussian  blue  makes  the  ink,  which  was  already  proof  against 
alkalines,  equally  proof  against  acids,  and  forms  a  writing  fluid,  which  cannot  be  erased 
from  paper  by  any  common  method  of  fraudulent  obliteration,  without  the  destruction 

of  the  paper. 

6thly.  I  manufacture  in  manner  following  a  red  writing  ink  which  is  generally 
superior  to  the  common  solutions  from  peach  wood  and  Brazil  wood,  not  only  in 
permanent  brilliancy  of  colour,  but  also  in  its  freedom  from  acid,  and  consequent  fitness 
*br  use  with  steel  pens.  I  first  boil  cochineal  repeatedly  in  successive  quantities  of  pure 
water,  till  it  ceases,  or  nearly  so,  to  give  out  any  colouring  matter.  1  then  boil  it  in 
water  containing  liquor  ammonise,  which  combines  after  the  manner  of  an  alkali  with 
an  acid,  with  the  residue  of  colouring  matter,  and  leaves  the  insect  matter  nearly  white. 
The  liquid  products  of  these  successive  boilings  are  then  thrown  together  into  an 
earthenware  vessel,  and,  in  order  to  get  rid  of  a  peculiar  element  or  |)rinciple,  still  com- 
bined with  the  colouring  matter,  and  which  has  a  ^eat  aflSnity  for  iron,  I  precipitate 
the  colouring  matter  with  ammonia-bichloride  of  tin.  The  precipitate  is  afterwards 
dissolved  in  ammonia,  and  protiodide  of  tin  added,  till  a  suflicient  degree  of  brilliancy 
of  colour  is  obtained,  which  completes  the  process,  water  being  added  ad  libitum, 
according  to  the  degree  of  body  rec^uired  to  be  given  to  the  ink. 

7thly.  I  manufacture  by  the  improved  process  following  a  marking  ink  which 
may  be  used  with  steel  pens,  and  is  not  only  of  great  intensity  of  colour,  but  comes  out 
most  readily  on  the  application  of  beat.  I  rub  together  in  a  mortar  nitrate  of  silver 
and  the  proper  equivalent  of  tartaric  acid  in  a  dry  state.  I  then  add  water,  on  which 
crystals  of  tartrate  of  silver  are  formed  and  the  nitric  acid  set  free.  I  next  neutralize 
this  acid  by  adding  liquor  ammonise,  which  also  dissolves  the  tartrate  of  silver.  I 
finally  add  gum,  colouring  matter,  and  water,  in  the  usual  way,  and  in  quantities  which 
may  be  varied  at  pleasure.  By  this  process  the  nitric  acid,  which  is  essential  to  a  good 
marking  ink,  is  retained  and  the  tartrate  of  silver  formed  is  soluble  in  less  than  half 
the  quantity  of  liquor  ammonias  ordinarily  required  when  tartrate  of  silver  is  the  basis 
of  the  ink.  The  tedious  operation  of  filtering  and  washing  the  carbonate  of  silver  in 
order  to  form  the  tartrate  is  also  thereby  entirely  dispensed  with. 

Sthly.  I  manufacture  in  manner  ifoUowing  a  marking  ink,  diflfering  from  the 
preceding  and  all  other  marking  inks  containing  salts  of  silver  only,  in  this  respect, 
that  it  cannot  be  acted  upon  by  the  common  solvents  of  salts  of  silver,  as  cyanide  of 
potassium,  or  chloride  of  lime,  and  is  so  far,  therefore,  more  indelible.  I  take  the  ink, 
as  it  has  been  formed  by  the  process  last  described,  and  add  to  it  an  ammoniacal  solution 
of  an  oxide  or  salt  of  gold.  I  have  used  for  this  purpose  the  purple  of  Cassius,  the 
hyposulphite  of  gold,  the  ammonia-iodide  of  gold,  and  amraouia-periodide  of  gold. 
The  two  last  salts,  which  I  believe  to  be  new  salts,  I  obtain  by  dissolving  iodine  in 
liquor  ammoniae,  under  the  application  of  heat ;  an  operation,  however,  which  requires 
to  be  conducted  with  great  caution  in  order  to  prevent  the  formation  of  the  explosive 
compound,  the  teriodide  of  nitrogen.  This  iodine  solution  is  a  very  speedy  solvent  of 
gold.  If  gold  leaf  be  placed  upon  it  without  the  addition  of  water,  a  black  oxide  of 
gold  is  formed,  which  immediately  dissolves,  but  if  it  be  diluted  with  water,  the  process 
of  oxidation  is  less  rapid,  and  the  gold  leaf  assumes  a  fine  purple  colour  (not  black), 
before  solution.  This  salt  of  gold  crystallizes  in  four-sided  prisms,  which  are  soluble 
in   water.    A   few   drops  of  this  Bolution  placed  on  a  slip  of  glass  generally  form 


IODINE. 


1059 


raicroscipic  arborescent  crystals,  from  which,  under  the  application  of  heat,  both  the 
iodine  and  ammonia  may  be  volatilized,  and  arborescent  metallic  gold  alone  remains.  If 
a  mtjderate  heat  only  is  employed,  one  equivalent,  only  of  iodine  is  expelled,  and  white 
crystals  of  ammonia-iodide  of  gold  remain. 

9thly.  I  manufacture  a  blue  printing  ink  by  taking  the  soluble  precipitate  of 
cyanogen  and  iron,  obtained  by  the  process  described  under  the  first  head  of  this 
specification,  and  rubbing  up  the  same  in  oil,  after  the  manner  ordinarily  followed  in 
the  manufacture  of  printing  inks;  or  by  boiling  down  the  blue  writing  ink,  produced 
by  the  said  process  to  a  sufficient  consistence,  and  then  rubbing  up  the  same  in  oil. 

lOthly.  I  manufacture  a  black  printing  ink  by  boiling  down  the  black  writing  ink, 
produced  from  the  materials,  and  by  the  process  described  under  the  fifth  head  of  this 
specification,  and  rubbing  it  up  in  oil  as  aforesaid. 

nth.  I  manufacture  a  red  printing  ink  by  taking  the  ammoniacal  solution  of 
cochineal,  obtained  by  the  process  described  under  the  sixth  head  of  this  specification, 
and  rubbing  it  up  in  oil,  adding  protiodide  of  tin  according  to  the  degree  of  lustre 
required;  or  by  boiling  down  the  red  writing  ink,  produced  by  the  said  process,  to  a 
sufficient  consistence,  and  then  rubbing  up  the  same  in  oil  as  aforesaid. 

And  12th,  I  manufacture  a  black  printing  ink  by  boiling  chips  of  Ic^wood  (for 
which  an  extract  of  logwood  may  be  substituted),  or  other  dye  woods,  containing 
colouring  matter  and  tannin,  along  with  as  much  of  proto-salt  or  persalt  of  iron  or 
copper,  or  other  precipitate  of  tannin,  as  will  be  equal  to  about  twice  the  weight  of  the 
tannin  contained  in  the  wood  or  extract  employed ;  whereby  I  obtain  a  black  or  blueish 
black  precipitate ;  the  blueness  of  which  I  diminish,  as  may  be  required,  by  the 
addition  of  bichromate  of  potash,  more  or  less.  I  finally  rub  up  the  whole  in  oil  as 
aforesaid,  adding  a  small  quantity  of  the  lamp-black,  or  other  black  colouring  matter, 
ordinarily  employed  in  the  manufacture  of  black  printing  inks. 

INULINE  (Eng.  and  Fr.)  is  a  substance  first  extracted  from  the  root  of  the  Inula-Hd- 
leniurrij  or  Elecampane.  It  is  white  and  pulverulent  like  starch ;  and  differs  from  ihia 
substance  chiefly  because  its  solution,  when  it  cools,  lets  fall  the  inuline  unchanged  in 
jwwder,  wliereas  starch  remains  dissolved  in  the  cold,  as  a  jelly  or  paste. 

Inuline  is  obtained  by  boiling  the  root  sliced  in  3  or  4  times  its  weijiht  of  water,  and 
setting  the  strained  decoction  aside  till  it  cools,  when  the  pulverulent  inuline  precipitates. 
It  exists  also  in  the  roots  of  colchicum,  and  pellitory. 

IODINE  (lode,  Fr. ;  lod.  Germ.)  is  one  of  the  archoeal  undecompounded  chemical 
bodies,  which  was  discovered  accidentally  in  1812  by  M.  Courlois,  a  manufacturer  of 
saltpetre,  in  the  mother-waters  of  that  salt.  Its  affinities  for  other  substances  are  so 
powerful  as  to  prevent  it  from  existing  in  an  insulated  state.  It  occurs  combined  with 
potassium  and  sodium  in  many  mineral  waters,  such  as  the  brine  spring  of  Ashby-de-la- 
Zouche,  and  other  strongly  saline  'springs.  This  combination  exists^paringly  in  sea- 
water,  abundantly  in  many  species  of  fucus  or  sea-weed,  and  in  the  kelp  made  from 
them  ;  in  sponges ;  in  several  marine  molluscs,  such  as  the  doris,  the  reyius,  oysters,  Sec. ; 
in  several  polyparies  and  sea  plants,  as  the  gorgonia,  the  zosiera  marina,  &c.;  particu- 
larly in  the  mother-waters  of  the  salt-works  upon  the  Mediterranean  sea ;  and  it  has 
been  found  in  combination  with  silver,  in  some  ores  brought  from  the  neighborhood  of 
Mexico. 

Iodine  is  most  economically  procured  from  the  mother-water  of  kelp,  as  furnished  by 
those  manufacturers  of  soap  in  Scotland  and  elsewhere  who  employ  this  crude  alkaline 
matter.  By  pouring  an  excess  of  sulphuric  acid  upon  that  liquid,  and  exposing  the 
mixture  to  heat  in  a  retort,  iodine  rises  in  violet  vapors  (whence  its  name),  and  condenses 
in  the  receiver  into  black,  brilliant,  soft,  scaly  crystals,  resembling  graphite  or  plumbago. 
An  addition  of  the  peroxyde  of  manganese  to  the  above  mixture,  favors  the  production 
of  iodine.  Souberain  has  proposed  as  a  means  of  extracting  it  in  greater  abundance 
from  a  given  quantity  of  the  said  mother-Waters,  to  transform  the  iodide  of  potash  or 
soda,  present,  into  an  insoluble  iodide  of  copper,  by  pouring  into  them  solution  of 
sulphate  of  copper,  which  precipitates  first  of  all  one  half  of  the  iodine.  He  then 
decants  the  supernatant  liquor,  and  adds  to  it  a  fresh  quantity  of  the  sulphate  along 
with  some  iron  filings.  The  latter  metal  seizes  the  oxygen  and  »:ulphuric  acid  of 
the  cupreous  salt,  sets  the  copper  free,  which  then  seizes  the  other  half  of  the 
iodine.  To  separate  this  iodide  from  the  remaining  iron  filings,  he  agitates  the 
whole  with  water,  and  decants  the  liquor.  The  filings  immediately  subside,  but  the 
iodide  of  copper  remains  for  some  time  in  a  state  of  suspension.  This  compound, 
separated  by  a  filter  cloth,  is  to  be  mixed  with  twice  its  weight  of  the  black  peroxyde 
of  manganese,  and  as  much  sulphuric  acid  as  will  make  the  mixture  into  a  paste ;  which 
mixture  being  introduced  into  a  retort,  and  distilled,  the  iodine  comes  over  in  its  cha- 
racteristic violet  vapors,  which  are  condensed  into  the  glistening  black  substance  in  the 
receiver. 

Iodine  is  always  solid  at  atmospheric  temperatures^  though  it  slowly  flies  off  with  ■ 


1060 


IRON. 


peculiar  offensive  penetrating  odor  somewhat  like  chlorine.  Its  specific  ginvily  ii 
4*946  at  the  temperature  of  58°  Fahr.  Its  prime  equivalent,  according  to  Beizeliuis.  is 
63*283,  one  volume  of  hydrogen  being  1-000  ;  but  126-566,  if  two  volumes  ol  hydroiren 
be  reckoned  unity,  as  most  British  chemists  estimate  it,  from  the  composition  of  water. 
It  possesses  In  a  high  degree  electro-negative  properties,  like  oxygen  and  chlorine;  and 
therefore  makes  its  appearance  at  the  positive  pole,  when  its  compounds  are  placed  in  the 
voltaic  circuit.  It  stains  the  skin  yellow;  and  if  applied  for  some  time  to  it,  is  apt  tc 
produce  painful  ulcerations. 

Iodine  melts  only  at  about  390°  Fahr. ;  but  with  the  vapor  of  water  it  volatilizes  at  212° 
It  has  a  great  affinity  for  hydrogen,  and  constitutes  by  that  union  hydriodic  acid  ;  a  com- 
pound resembling  in  some  respects  muriatic  or  hydrochloric  acid.  It  also  can  be  combin- 
ed with  oxygen,  and  forms  thereby  iodic  acid.  Its  compounds  with  carbon,  phosphorus, 
sulphur,  chlorine,  azote,  and  many  metals,  have  not  been  applied  to  any  manufacturing 
purpose^  and  therefore  need  not  be  described  here. 

The  chief  application  of  iodine  in  the  arts,  is  for  the  detection  of  starch,  which  its 
watery  solution,  though  containing  only  one  part  in  5000,  does  readily,  by  the  production 
of  a  deep  purple  color ;  this  vanishes  by  exposing  the  starch  to  the  air  for  some  time,  or 
more  quickly  by  heating  it. 

As  a  medicine,  iodine  and  its  compounds,  such  as  the  iodides  of  potassium  and  iron,  are 
supposed  to  possess  great  powers  in  resolving  glandular  swellings.  The  periodide  of  mer- 
cury is  a  brilliant  red  pigment,  but  somewhat  evanescent. 

Chlorine,  bromine,  and  iodine,  are  frequently  associated  ;  and  it  has  hither'o  been 
reckoned  a  difficult  problem  to  separate  them  from  one  another.  The  following  Ian  is 
proposed  by  Mr.  Loviff. 

Heat  the  mixture  of  the  dried  chloride  and  bromide  (or  chloride  and  iodide)  while  a 
current  of  chlorine  is  made  to  pass  over  it,  till  no  more  bromine  is  carried  off  by  the 
chlorine.  Receive  the  gases  in  a  solution  of  potash ;  saturate  this  fluid  mixture  of  the 
chloride  of  potassium,  and  the  chlorate  and  bromate  of  potash  with  nitric  acid,  adding 
afterwards  nitrate  of  silver.  A  mixture  of  bromate  and  chloride  of  silver  will  precipitate. 
Dry  the  precipitate,  calcine  it,  and  calculate  the  proportion  of  bromine  from  the  volume 
of  oxygen  gas  now  disengaged.  It  would  be  preferable  to  digest  in  a  vial,  the  precipi- 
tate while  moist,  along  with  water  of  baryta,  which  decomposes  the  bromate  of  silver 
without  acting  upon  the  chloride.  The  excess  of  baryta  being  thrown  down  by  carbonic 
acid,  and  the  liquid  being  evaporated,  a  bromate  of  baryta  is  obtained,  which  may  be 
washed  with  alcohol  of  0-840.  The  solution  of  bromate  of  baryta  may  also  be  neutral- 
ized by  nitric  acid,  and  the  bromic  acid  may  be  precipitated  by  nitrate  of  silver.  The 
same  method  is  applicable  to  the  separation  of  iodine  from  chlorine. 

After  throwing  down  the  solution  of  the  mixed  salts  by  nitrate  of  silver,  Berzelius 
digests  the  washed  precipitate  in  a  closed  bottle  of  water  of  baryta ;  whence  results 
bromate  of  baryta  without  any  chloride  of  barium.  On  evaporating  the  liquor  we  ob- 
tain crystallized  bromate  of  baryta,  which  may  be  freed  from  a  small  accidental  quantity 
of  chloride,  by  washing  with  alcohol  at  0-840.  By  calcination  we  then  obtain  bromide 
of  barium,  which,  being  distilled  with  sulphuric  acid  and  peroxyde  of  manganese,  affords 
bromine. 

IRIDIUM  is  a  metal  discovered  by  Descotils  in  1803,  as  also  by  Tenant  in  1804 ;  and 
is  so  called  because  its  different  solutions  exhibit  all  the  colors  of  the  rainbow.  It  occurs 
only  in  the  ore  of  platinum,  being  found  there  in  two  stales ;  1.  united  to  that  metal,  and 
2.  as  alloy  of  osmium  and  iridium,  in  the  form  of  small,  insulated,  hard  grains.  Iridium 
is  the  most  refractory  of  all  the  metals  ;  and  appears  as  a  gray  metallic  powder.  It  is 
not  fused  by  the  flame  of  the  hydroxy  gen  lamp. 

IRON  {Fer,  Fr. ;  Eisen,  Germ.)  is  a  metal  of  a  bluish-gray  color,  and  a  dull  fibrous 
fracture,  but  it  is  capable  of  acquiring  a  brilliant  surface  by  polishing.  Its  specific  gravity 
is  7-78.  It  is  the  most  tenacious  of  metals,  and  the  hardest  of  all  those  which  are  malleable 
and  ductile.  It  is  singularly  suscej-^ible  of  the  magnetic  virtue,  but  in  its  pure  state  soon 
loses  it.  When  rubbed  it  has  a  slight  smell,  and  it  imparts  to  the  tongue  a  peculiar 
astringent  taste,  called  chalybeate.  In  a  moist  atmosphere,  iron  speedily  oxydizes,  and 
becomes  covered  with  a  brown  coating,  called  rust. 

Every  person  knows  the  manifold  uses  of  this  truly  precious  metal;  it  is  capable  of 
beins  cast  in  moulds  of  any  form ;  of  being  drawn  out  into  wires  of  any  desired  strength 
or  fineness ;  of  being  extended  into  plates  or  sheets ;  of  being  bent  in  every  direction ;  of 
being  sharpened,  hardened,  and  softened  at  pleasure.  Iron  accommodates  itself  to  all 
our  wants,  our  desires,  and  even  our  caprices ;  it  is  equally  serviceable  to  the  arts,  the 
sciences,  to  agriculture,  and  war;  the  same  ore  furnishes  the  sword,  the  ploughshare,  the 
scythe,  the  pruning  hook,  the  needle,  the  graver,  the  spring  of  a  watch  or  of  a  carriage, 
the  chisel,  the  chain,  the  anchor,  the  compass,  the  cannon,  and  the  bomb.  Ii  is  a 
medicine  of  much  virtue,  and  the  only  metal  friendly  to  the  human  frame. 

The  ores  of  iron  are  scattered  over  the  crust  of  the  globe  with  a  beneficent  profusion, 
proportioned  to  the  utility  of  the  metal ;  they  are  found  under  every  latitude^  and  ever* 


IRON. 


1061 


zone  ;  in  every  mineral  formation,  and  are  disseminated  in  every  soil.  Considered  m  a 
purely  mineralogical  point  of  view,  without  reference  to  their  importance  for  reduction, 
they  may  be  reckoned  to  be  19  in  number;  namely,  1.  native  iron  of  three  kinds:  pure, 
nickeliferous,  and  steely;  2.  arsenical  iron;  3.  yellow  sulphuret  of  iron;  4.  w^hite  sul- 
phuret  of  iron;  5.  magnetic  sulphuret  of  iron;  6.  black  oxyde  of  iron,  either  the  load- 
stone, or  susceptible  of  magnetism,  and  titanfferous ;  7.  compact /er  oligiste,  specular  iron 
ore,  as  of  Elba,  and  scaly  fer  oligiste ;  8.  hematite,  affording  a  red  powder ;  9.  hematite 
or  hydrate  of  iron,  affording  a  yellow  powder,  of  which  there  are  several  varieties;  10. 
pitchy  iron  ore ;  11.  siliceo-calcareous  iron,  or  yenite  ;  12.  sparry  carbonate  of  iron,  and 
the  compact  clay  iron-stone  of  the  coal  formation ;  13.  phosphate  of  iron  ;  14.  sulphate 
of  iron,  native  copperas ;  15.  chromate  of  iron ;  16.  arseniate  of  iron ;  17.  muriate  of 
iron ;  18.  oxalate  of  iron ;  19.  titanate  of  iron. 

Among  all  these  different  species,  ten  are  worked  by  the  miner,  either  for  the  sake  of 
the  iron  which  they  contain  ;  for  use  in  their  native  state ;  or  for  extracting  some  prin- 
ciples from  them  advantageous  to  the  arts  and  manufactures ;  such  are  arsenical  iron, 
sulphate  of  iron,  sulphuret  of  iron,  and  chromate  of  iron. 

1.  Native  iron  a.  Pure. — This  species  is  very  rare,  and  its  existence  was  long  matter 
jf  dispute  ;  though  it  has  been  undoubtedly  found  not  only  in  volcanic  formations,  but  in 
veins  properly  so  called.  It  is  not  entirely  like  our  malleable  iron  ;  but  is  whiter,  more 
ductile,  more  permanent  or  less  oxydizable  in  the  air,  and  somewhat  less  dense.  Among 
the  best  attested  examples  of  pure  native  iron  is  that  observed  by  M.  Schreber,  in  the 
mountain  of  Oulle  near  Grenoble.  The  metal  was  entangled  in  a  vein  running:  through 
gneiss,  and  appeared  in  ramifying  stalactites,  enveloped  in  fibrous  brown-oxyde  of  iron 
mixed  with  quartz  and  clay. 

B.  The  native  nickeliferous  or  meteoric  iron  is  very  malleable,  often  cellular,  but  some- 
times compact,  and  in  parallel  plates,  which  pass  into  rhomboids  or  octahedrons.  It  is 
naturally  masnetic,  and  by  its  nickel  is  distinguishable  from  terrestrial  native  iron.  Mac- 
quart,  in  describing  the  famous  mass  found  at  mount  Kemir  in  Siberia,  says  that  the  iron 
is  perfectly  flexible,  and  fit  for  making  small  instruments  at  a  moderate  heat ;  but  in  too 
strong  a  fire,  the  metal  becomes  short,  brittle,  and  falls  into  grains  under  the  hammer. 
Meteoric  iron  is  covered  with  a  sort  of  varnish  which  preserves  its  surface  from  the  rust- 
in?  action  of  the  air ;  but  this  preservative  property  does  not  extend  to  the  interior. 
Chladni  has  given  a  list  of  masses  of  meteoric  iron,  which  have  been  known  to  fall  at 
different  times  from  the  atmosphere,  and  of  many  specimens  which  indicate  their  atmos- 
pheric origin,  by  their  aspect  and  composition.  A  portion  of  the  mass  of  meteoric  iron 
found  at  Santa-Rosa  near  Santa-Fe-de-Bogota,  was  made  into  a  sword  and  presented  to 
Bolivar. 

c.  Native  steel-iron. — This  substance  has  all  the  characters  of  cast-steel ;  it  occurs  in  a 
kind  of  small  button  ingots,  with  a  finely  striated  surface,  and  a  fracture  exceedingly  fine 
grained.  It  is  hardly  to  be  touched  by  the  file,  and  will  scarcely  flatten  under  the  ham- 
mer. M.  Mossier  found  this  native  steel  at  the  village  of  Bouiche,  near  Nery,  depart- 
ment of  the  Allier,  in  a  spot  where  there  had  existed  a  seam  of  burning  coal.  A  mass 
of  16  pounds  and  6  ounces  of  native  steel  was  discovered  in  that  place,  besides  a  great 
many  small  globules. 

2.  Jlrsenical  iron,  Jrsenikkies,  or  Mispickel,  is  a  tin- white  mineral,  which  emits  a  garlic 
smell  at  the  blowpipe,  or  even  when  sparks  are  struck  from  it  by  steel,  accompanied" with 
a  small  train  of  white  smoke.  It  contains  generally  more  or  less  sulphur,  and  sometimes 
a  little  silver,  associated  with  metallic  arsenic  and  iron. 

3.  Yellow  sulphuret  of  iron,  commonly  called  Marcasite,  or  Martial  pyrites.  The 
bronze  or  brass  yellow  color  enables  us  to  recognise  this  mineral.  At  the  blowpipe  it 
gives  oft'  its  sulphur,  and  is  converted  into  a  globule  attractable  by  the  blowpipe.  It  is  a 
bisulphuret  of  iron  containing  32  of  sulphur  and  28  of  metal. 

Copper  pyrites  may  be  distinguished  from  it  by  its  golden  yellow  color,  which  is  fre- 
quently iridescent,  and  by  its  inferior  hardness ;  for  it  does  not  strike  fire  with  steel,  like 
the  preceding  persulphuret.  There  is  no  vein,  stratum,  or  mass  of  metallic  ore  which 
does  not  contain  some  iron  pyrites ;  and  it  is  often  the  sole  mineral  that  fills  the  veins  in 
quartz.     It  sometimes  contains  gold,  and  at  other  times  silver. 

4.  White  sulphuret  of  iron.— This  is  distinguishable  from  the  preceding  species  only 
by  :j  color  and  form  of  crystallization,  and  was  hence  till  lately  confounded  with  it  by 
mineralogists.     Its  surface  is  often  radiated. 

5.  Magnetic  sulphuret  of  iron,  the  Magnetkies  of  the  Germans. — This  ore  is  attract- 
able by  ihe  magnet  like  common  iron.  Its  color  is  reddish-yellow,  passing  into  brown; 
its  fracture  is  rough.     It  consists  of  16  of  sulphur  and  28  of  iron. 

6.  Black  oxyde  of  iron,  magnet  ore,  or  native  loadstone.— One  variety  of  this  species 
has  two  poles  in  each  specimen,  which  manifest  a  repulsive  action  against  the  corres- 
ponding poles  of  a  magnetic  needle.  All  the  varieties  furnish  a  black  powder.  lu 
external  color  is  a  gray  approaching  to  that  of  metallic  iron,  but  somewhat  duller; 


I 


!l| 


1062 


IRON. 


with  occasional  iridescence  of  surface.  Neither  nitric  acid  nor  t\ie  blowpipe  has  any 
action  upon  it.  Its  specific  gravity  varies  from  4-24  to  5-4;  and  its  constituents  arc 
71-86  peroxyde,  and  28-14  protoxyde,  according  to  Berzelius;  or  in  100  parts,  71-74  ol 
metallic  iron,  and  28-26  of  oxygen.  Assuming  the  prime  equivalent  of  iron  to  be  -i», 
with  the  British  chemists,  then  an  ore  consisting,  like  the  above,  of  two  prime  propor- 
tions of  peroxyde,  and  one  of  protoxyde,  would  be  represented  by  the  number  116  =  80 
-f  36 ;  and  would  consist  in  100  parts,  of  iron  72-4,  oxygen  27-6.  .      ^      i     • 

Magnetic  iron-ore  belones  to  primitive  rock  formations,  and  occurs  abnndantly  in 
Sweden,  Dalecarlia,  Norway,  Siberia,  China,  Siam,  and  the  Philippine  isles;  but  it  is 
rare  in  England  and  France.  It  is  worked  extensively  in  Sweden,  and  furnishes  an  ex- 
cellent iron.  .  ,   .      ,  ^,    ,.     .V  ♦       Tio 

The  litanifcrous  oxyde  of  iron,  or  iron  sand,  is  also  attractable  by  the  magnet,  lis 
color  is  a  deep  black,  with  some  metallic  lustre ;  it  is  perfectly  opaque ;  its  fracture  is 
conchoidal ;  it  is  hard  and  difficult  to  grind  under  the  pestle  into  a  dull  black  powder, 
which  stains  the  fingers  when  it  is  very  fine ;  it  melts  at  a  high  heat  into  a  black  enamel 
without  lustre.  All  volcanic  rocks  contain  a  greater  or  less  quantity  of  titanic  iron-ore, 
disseminated  through  them,  which  may  be  recognised  by  its  brilliant  metallic  lustre,  and 

its  perfect  conchoidal  fracture.  v      .v       i       e 

7.  Fer  oligiste,  iron-glance,  specular  iron,  and  red  iron  ore.— This  ore  has  the  color  of 
polished  steel ;  and  the  light  transmitted  through  the  thin  edges  of  its  crystals  appears  of 
a  beautiful  red.  Its  powder  is  always  of  a  well  marked  brown-red  hue,  passing  into 
cherry-red,  which  distinguishes  it  from  the  black-oxyde  ore.  Its  fracture  is  rough,  or 
vitreous  in  certain  varieties ;  it  breaks  easily;  but  it  is  hard  enough  to  scratch  glass.  It 
usually  contains  from  60  to  70  of  metallic  iron  in  100  parts;  the  equivalent  proportion 
of  oxygen  in  the  pure  red  oxyde  of  iron  being  30  parts  combined  with  70  ol  metal.  It 
is  a  mistake  to  suppose  any  specular  iron  ore  capable  of  yielding  85  per  cent,  of  iron,  lor 
100  parts  of  even  protoxyde  of  iron  contain  only  77-77  parts  of  metal. 

The  compact  variety  comprises  the  crystals  of  the  island  of  Elba,  and  of  Framont  m 
the  Vosges,  which  have  a  rough-grained  fracture.  It  exists  in  very  great  masses,  consti- 
tuting even  entire  mountains;  in  the  cavities  and  fissures  of  these  masses,  the  beautiful 
crystals  so  much  prized  by  collectors  of  minerals,  occur. 

The  island  of  Elba  is  equally  celebrated  for  its  inexhaustible  abundance  of  rich  specular 
iron  ore,  and  for  the  immemorial  antiquity  of  it«  mining  operations.    Ftg.  792  is  a  vertical 

102 


section  passing  through  the  three  working?,  called  Pietamonte  (d),  Sanguinaccio  (b;, 
Antenna  (f).  through  an  ancient  excavation  a,  through  the  coast  o,  and  the  mole  p,  end- 
ing at  the  canal  of  Piombino.  The  total  height  of  the  metalliferous  mountain  above  the 
level  of  the  sea,  is  no  more  than  180  metres,  or  600  feet.  „   ,  l-      l  *.    u 

The  rock  which  constitutes  the  body  of  this  little  mountain  d  /,  is  called  hxanchetta  by 
the  workmen.  It  is  a  white  slaty  talc,  slightly  ochreous,  or  yellowish,  consisting  chietly 
of  silica  and  alumina,  with  some  magnesia.  ^  .i,-     ♦        .  «•« 

The  ore  of  Antenna  (f)  is  a  very  hard  compact  fer  ohgisie,  of  a  brilliant  me  al  ic 
aspect  The  workable  bed  has  a  height  of  66  feet,  and  consists  of  metalliferous  blocks 
mixed  confusedly  with  sterile  masses  of  the  rock  ;  the  whole  covered  with  a  rocky  detri- 
tus under  a  brownish  mould.  From  its  metallic  appearance  and  toughness,  this  bed  is 
called  vena  ferrata,  the  iron  vein.  In  Pietamonte  the  workable  bed  is  composed  entirely 
of  micaceous  specular  iron  ore  {fer  oligiste),  with  its  fissures  filled  with  yellow  ochre. 
This  bed  rests  upon  the  rock  called  bianchetta ;  the  brilliant  aspect  of  ore  in  this  place 
has  gained  for  it  the  name  of  vena  Incdola. 

The  metalliferous  hill  d  I,  extends  to  the  north-east,  about  a  mile  beyond  the  work- 
ings D  E  F.      The  ore  contains  about  65  per  cent,  of  iron,  and  is  smelted  in  Catalan 

the  following  description  of  the  figure  will  make  the  structure  of  this  extraordinary 
mine  well  understood,     a,  is  a  great  excavation,  the  result  of  ancient  workings. 

1,  1 ;  2,  2 ;  3, 3,  4,  4,  5,  6,  and  7,  are  roads  for  carrying  off  the  rubbish,  m  correspona 
ence  with  the  several  working  levels. 


IRON. 


1063 


6,  6,  6,  masses  of  old  rubbish  (deblais), 

c,  c,  ditto,  from  the  present  workings  d,  e,  f. 

d,  the  rocky  mass  called  bianchetta,  agninst  which  the  ore  extracted  from  a  abuts. 

e,  the  surface  of  a  bed  of  ore,  near  the  streamlet  g. 

f,  f,  indication  of  beds  of  iron  pyrites  and  fer  oligiste. 

g,  a  small  rivulet  proceeding  from  the  infiltration  of  rains,  and  which  is  impregnated 
with  acidulous  sulphate  of  iron. 

h,  h,  ravine  which  separates  the  metalliferous  hill  d  I  from  the  barren  hill  t. 

k,  masses  of  slags  from  ancient  smelting  operations ;  such  are  very  common  in  this 
island.  None  of  any  consequence  now  exist;  nearly  the  whole  of  the  ore  being  ex- 
ported to  Tuscany,  the  Romagna,  the  Genoese  territories.  Piedmont,  Naples,  and 
Corsica. 

/,  a  considerable  body  of  rubbish  from  ancient  workings,  towards  the  summit  of  the 
metalliferous  hill  d,  I. 

wi,  wi,  part  of  this  hill  covered  with  rubbish,  the  result  of  old  workings. 

n,  the  site  called  Vigneria. 

0,  houses  upon  the  shore  called  Marirsi  de  Rio,  where  the  workpeople  live,  and  the 
mineral  is  kept  in  store. 

p,  wooden  pier  (mole)  whence  the  ore  is  shipped ;  terminated  by  a  small  tower,  q. 

Compact  fer  oligiste  occurs  also  in  the  Vosges,  in  Corsica,  at  Altenberg  and  Freyburg, 
in  Saxony,  Presnitz,  in  Bohemia,  Norberg  and  Bisberg,  in  Sweden,  &c. 

The  varieties  called  specular  fer  oligiste,  and  scaly  fer  oligiste,  or  iron-glance,  do  not 
differ  essentially  from  the  compact.  None  of  them  affects  the  magnetic  needle,  and  their 
powder  is  a  red  of  greater  or  less  vivacity. 

8.  Red  oxyde  of  iron. — The  varieties  included  under  this  species  afford  a  red  powder, 
do  not  afiect  the  magnetic  needle,  and  are  destitute  of  metallic  lustre.  At  the  blowpipe 
•hey  all  become  black,  or  deep  brown ;  and  then  they  act  on  the  needle.  The  crystal- 
.ized  variety  consists  of  70  iron  and  30  oxygen  in  100  parts.  The  concretionary  kind, 
or  hematite,  has  a  brown-red  color ;  is  solid,  compact,  and  sometimes  very  hard ;  its 
surface  may  be  filed  and  polished  so  as  to  acquire  a  lustre  almost  metallic ;  its  internal 
structure  is  fibrous,  and  it  exhibits  sometimes  a  resemblance  to  splinters  of  wood.  ItJ 
outer  surface  is  constantly  concretionary,  mammelated,  and  presents  occasionally  sections 
of  a  sphere,  or  cylinders  attached  to  each  other.  This  is  the  blood-stone  of  the  burnisher 
of  metals.  It  is  a  very  common  mineral.  The  ochry  variety  or  red-iron-ochre  is  dis- 
tinguished from  the  solid  hematite  by  the  brightness  of  its  color.  It  is  used  as  a 
pigment. 

9.  Brown  oxyde  of  iron,  brown  iron-stone. — This  affords  always  a  yellow  powder, 
without  any  shade  of  red,  which  passes  sometimes  into  the  bistre  brown,  or  velvet  black. 
At  the  blowpipe  this  oxyde  becomes  brown,  and  very  attractable  by  the  magnet;  but  after 
calcination  and  cooling,  the  ore  yields  a  red  powder,  which  stains  paper  nearly  as  red 
as  hematite  does,  and  which  is  much  employed  in  polishing  metals.  All  the  yellow  or 
brown  oxydes  contain  a  large  proportion  of  water,  in  chemical  combination ;  and  hence 
this  species  has  been  called  hydrate  of  iron.  There  are  several  varieties  which  assume 
globular,  reniforra,  stalactitic,  and  fruticose  shapes.  As  impure  varieties  of  the  species 
we  must  consider  some  of  the  clay-iron  ores,  such  as  the  granular,  the  common,  the  pisi« 
form,  and  the  reniform  clay-iron  ore.  According  to  D'Aubuisson,  the  present  specie? 
consists  of  peroxyde  of  iron,  from  82  to  84  per  cent. ;  water,  14  to  11 ;  oxyde  of  manga- 
nese, 2 ;  silica,  1  to  2.  It  is  therefore  a  hydrated  peroxyde  of  iron  ;  and  ought  by  theory 
to  consist,  in  its  absolute  state,  of  81*63  peroxyde,  and  18-37  water.  It  occurs  both  in 
beds  and  veins.  The  atites  or  eagle-stones  form  a  particular  variety  of  this  ore.  On 
breaking  the  balls,  so  named,  they  are  observed  to  be  composed  of  concentric  coats,  the 
ontside  ones  being  very  hard,  but  the  interior  becoming  progressively  softer  towards  the 
centre,  which  is  usually  earthy  and  of  a  bright  yellow  color ;  sometimes,  however,  the 
centre  is  quite  empty,  or  contains  only  a  few  drops  of  water.  Utiles  occur  in  abundance, 
oAen  even  in  continuous  beds  in  secondary  mountains,  and  in  certain  argillaceous  strata. 
These  stones  are  still  considered  by  the  French  shepherds  as  amulets  or  talismans,  and 
may  be  found  in  the  small  bags  which  they  suspend  to  the  necks  of  their  favorite  rams ; 
and  they  are  in  such  general  use,  that  a  large  quantity  is  annually  imported  into  France 
from  the  frontiers  of  Germany,  for  this  superstitious  purpose.  When  smelted,  they  yield 
a  good  iron. 

The  variety  called  gran^ilar  brovm  oxyde,  or  bone  ore,  is  merely  a  modification  of 
the  preceding.  It  occurs  in  grains  nearly  round,  varying  in  size  from  a  millet  seed  to  a 
pea,  each  being  composed  of  concentric  coats,  hard  outside  and  soft  within.  They  are 
generally  agglutinated  by  a  calcareous  or  argillaceous  paste;  but  are  occasionally  quite 
loose.  This  ore  occurs  in  calcareous  formations,  and  is  sometimes  accompanied  with 
shells,  such  as  terebratula.  The  brittle  quality  of  the  iron  afforded  by  it  has  been 
ascribed  to  the   phosphorus  derived  from  the  large  quantity  of  organic  bodies,  with 


1064 


IRON. 


which  the  ore  is  frequently  mixed.     The  bog-iron  ore  and  swamp-iron  ore  belong  to  thit 
species. 

10.  Pitchy  hydrate  of  iron. — This  is  a  rare  mineral  of  a  resinous  aspect,  found  in  a 
vein  in  the  mine  of  Braunsdorf,  two  leagues  from  Freyberg,  and  seems  to  consist  of  red 
oxyde  of  iron  and  water. 

11.  Yenite  is  a  mineral  species,  rather  rare,  composed  of  red  oxyde  of  iron,  silica,  and 

lime. 

12.  Carbonate  of  iron,  sparry  iron,  or  brown-spar. — This  important  species  has  been 
divided  into  two  varieties ;  spathose  iron  and  the  compact  carbonate.  The  first  has  a 
sparry  and  lamellar  fracture ;  with  a  color  varying  from  yellowish-gray  lo  isabella  yel- 
low, or  even  to  brownish-red.  It  turns  brown  without  meliing  at  the  blowpipe,  and 
becomes  attractable  by  the  magnet  after  being  slightly  roasted  in  the  flame  of  a  candle. 
Even  by  a  short  exposure  to  the  air,  aAer  its  extraction  from  the  mine,  it  also  assumes  the 
same  brown  tint,  but  without  acquiring  the  magnetic  quality.  It  affords  but  a  slight 
effervescence  with  nitric  acid,  changing  merely  to  a  red-brown  color.  Its  specific  gravity 
Taries  from  3*00  to  3*67.  Its  primitive  form  is  like  that  of  carbonate  of  lime,  an  obtuse 
rhomboid.  Without  changing  this  form,  its  crystals  are  susceptible  cf  containing  varia- 
ble quantities  of  carbonate  of  lime,  till  it  passes  wholly  into  this  minual.  Manganese 
and  magnesia  enter  also  occasionally  into  its  composition. 

Sparry  carbonate  of  iron  belongs  to  primitive  formations ;  forming  powerful  veins  in 
mountains  of  gneiss,  and  is  associated  in  these  veins  with  quartz,  copper  pyrites,  gray 
copper,  fibrous  brown  oxyde  of  iron,  and  a  variety  of  ramose  carbonate  of  lime,  vulgarly 
called  Jios  ferri.  Thus  it  is  found  at  Alievard  and  Vizille,  near  Grenoble,  at  Saint- 
George  d'Huretiere,  in  the  Alps  of  Savoy ;  at  Baigorry,  in  the  Lower  Pyrenees ;  at  Eis- 
enerz,  in  Styria ;  at  Huttenberg,  in  Carinthia ;  at  Schwartz,  in  the  Tyrol ;  in  Saxony, 
Hungary,  other  places  in  Germany,  as  also  in  Spain,  Sweden,  Norway,  and  Siberia.  It 
also  occurs,  along  with  galena  and  other  ores  of  lead,  in  the  mines  of  Lead-Hills  and 
Wanlockhead,  in  Scotland ;  and  in  the  mines  of  Cumberland,  Northumberland,  and 
Derbyshire ;  likewise  with  tin-ore,  at  Wheal  Maudlin,  Saint-Just,  and  other  places  in 
Cornwall. 

This  ore,  viewed  as  a  metallurgic  object,  is  one  of  the  most  interesting  and  valuable 
that  is  known ;  it  affords  natural  steel  with  the  greatest  facility,  and  accommodates  itself 
best  to  the  Catalan  smelting  forge.  It  was  owing  in  a  great  measure  to  the  peculiar 
quality  of  the  iron  which  it  produces,  that  the  excellence  long  remarked  in  the  cutlery 
of  the  Tyrol,  Styria,  and  Carinthia,  was  due.  It  was  called  by  the  older  mineralogists 
iteel  ore. 

The  carbonate  of  iron  of  the  coal  formation,  is  the  principal  ore  from  which  iron  is 
smelted  in  England  and  Scotland,  and  it  yields  usually  from  30  to  33  per  cent,  of  cast 
metal.  We  are  indebted  to  Dr.  Colquhoun  for  several  elaborate  analyses  of  the  sparry- 
irons  of  the  Glasgow  coal  field ;  ores  which  afford  the  best  qualities  of  iron  made  in  that 
district.  The  richest  specimen,  out  of  the  nine  which  he  tried,  came  from  the  neighbor- 
hood of  Airdrie;  it  had  a  specific  gravity  of  30533,  and  afforded  in  100  parts,  carbonic 
acid,  35- 17  ;  protoxyde  of  iron,  53*03  ;  lime,  3-33;  magnesia,  1-77  ;  silica,  1*4;  alumina, 
0*63;  peroxyde  of  iron,  0*23 ;  carbonaceous  or  bituminous  matter,  3  03;  moisture  and 
loss,  1-41.     Its  contents  in  metallic  iron  are  41-25. 

The  compact  carbonate  of  iron  has  no  relation  externally  with  the  sparry  variety.  It 
comprehends  most  of  the  clay-iron  stones,  and  particularly  that  which  occurs  in  flattened 
spheroidal  masses  of  various  size,  among  the  coal  measures.  The  color  of  this  ore  is 
often  a  yellowish-brown,  reddish-gray,  or  a  dirty  brick-red.  Its  fracture  is  close  grained; 
it  is  easily  scratched,  and  gives  a  yellowish-brown  powder.  It  adheres  to  the  tongue, 
has  an  odor  slightly  argillaceous  when  breathed  upon,  makes  no  effervescence  with  any 
acid,  blackens  at  the  blow-pipe  without  melting,  and  becomes  attractable  by  the  magnet 
with  the  slightest  calcination. 

This  ore  affords  from  30  to  40  per  cent,  of  iron  of  excellent  quality ;  and  it  is  the 
object  of  most  extensive  workings  in  Great  Britain.  It  occurs  in  the  slaty  clay  which 
serves  as  a  roof  or  floor  to  the  strata  of  coal;  and  also  in  continuous  beds,  from  2  lo  18 
inches  thick,  among  the  coal  measures,  as  in  Staffordshire,  Shropshire,  and  Wales.  It  is 
remarkable,  that  the  coal-basin  of  Newcastle  contains  little  clay  iron-slone,  while  the 
coal-basin  of  Dudley  is  replete  with  it. 

13.  Phosphate  of  iron. — A  dull  blue  color  is  the  most  remarkable  external  character 
of  this  species,  which  occurs  in  small  masses  composed  of  aggregated  plates,  sometimes 
in  an  excessively  fine  powder,  or  giving  other  bodies  a  blue  tinge.  It  assumes  at  the 
blowpipe  a  rusty  hue,  and  is  then  reduced  to  a  button  of  a  metallic  aspect.  It  dissolves 
completely  in  dilute  nitric  acid,  as  well  as  in  ammonia,  but  it  doe^  not  communicate  its 
color  to  them,  and  oil  turns  it  black  ;  characters  which  distinguish  it  readily  from  blue 
carbonate  of  copper,  whose  color  is  not  altered  by  ammonia.  It  is  of  no  use  as  a 
smelting  ore. 


IRON. 


1065 


14.  Sulphate  of  ircm,  native  green  vitriol.— This  is  formed  by  the  oxygenation  of  sal 
phuret  of  iron,  and  is  unimportant  in  a  metallurgic  point  of  view. 

15.  Ckromale  of  iron. — For  the  treatment  and  use  of  this  ore,  see  Chrome. 

16.  Jrseniate  of  iron,  Wurfelerz. 

17.  Muriate  of  iron. 

18.  Oxalate  of  iron;  Humboldtife,  found  by  M.  Breilhaupt  in  the  lignite  of  Kolaw.  11 
consisisof  protoxyde  of  iron,  53-86;  oxalic  acid,  46-14;  in  100. 

19.  Titanate  of  iron  consists  of  protoxyde  and  peroxyde  of  iron,  86 ;  titanic  acid,  8 ; 
oxyde  of  manganese,  2;  gangue,  1  ^  97.     See  Black  Oxyde  of  iron. 

Of  the  assay  of  iron-ores  by  fusion. — In  the  assays  by  the  dry  way,  the  object  is  to  sep- 
arate exactly  all  the  iron  which  the  ore  may  contain,  with  the  view  of  comparing  the  result 
with  the  product  of  smelling  on  the  great  scale.  In  order  to  succeed  in  this  operation, 
we  must  deoxydize  the  iron,  and  produce  at  the  same  time  such  a  temperature  as  will 
melt  the  metal  and  the  earths  associated  with  it  in  the  ore,  and  obtain  the  former  in  a 
dense  button  at  the  bottom  of  a  crucible,  and  the  latter  in  a  lishter  glass  or  slag,  above  it. 
Sometimes  the  gangue  of  the  ores,  consisting  mostly  of  a  single  earth,  as  quartz,  alumina, 
or  lime  is  of  itself  very  refractory,  and  hence  some  flux  must  be  added  to  bring  about  the 
fusion.'  The  substance  most  commonly  employed  for  this  purpose  is  borax  ;  but  ordinary 
flint  glass  may  be  substituted  for  it.  Sometimes,  also,  instead  of  adding  borax,  which 
always  succeeds,  lime  or  clay  may  be  added  to  the  ore,  according  to  the  nature  of  its 
mineralizer ;  that  is,  lime  for  a  clay  iron-stone,  and  clay  for  a  calcareous  carbonate  of 
iron  ;  and  both,  when  the  gangue  is  silicious,  as  occurs  with  the  black  oxyde. 

The  ore,  pulverized  and  passed  through  a  silk  sieve,  is  to  be  well  mixed  with  the  flux, 
and  the  mixture  introduced  into  the  smooth  concavity  made  in  the  centre  of  a  crucible 
lined  with  hard-rammed  damp  charcoal  dust.  Were  the  mixture  diffused  through  the 
charcoal,  the  reduced  iron  would  be  apt  to  remain  scattered  in  little  globules  through 
the  crucible,  and  no  metallic  button  would  be  formed  at  its  bottom.  The  mingled  ore  and 
flux  must  be  covered  with  charcoal.  The  crucible  thus  filled  must  be  shut  with  an  earthen 
lid  luted  on  with  fire-clay ;  and  it  is  then  set  on  its  base,  either  in  an  air  furnace,  or  on 
the  hearth  of  a  forge  urged  with  a  smith's  bellows.  The  heat  should  be  very  slowly  raised, 
not  employing  the  bellows  till  three  quarters  of  an  hour  have  expired.  In  this  way,  the 
water  of  the  damp  charcoal  (brasque)  is  allowed  to  exhale  slowly,  and  the  deoxydation  is 
completed  before  the  fusion  begins ;  for  by  acting  otherwise,  the  slags  formed  would  dis- 
solve some  oxyde  of  iron,  and  the  assay  would  not  indicate  the  whole  of  the  iron  to  be 
obtained  from  the  ore.  At  the  end  of  the  above'  period,  the  fire  must  be  raised  progres- 
sively to  a  while  heat,  at  which  pilch  it  must  be  maintained  for  a  quarter  of  an  hour, 
after  which  the  crucible  should  be  withdrawn.  Whenever  it  has  cooled,  it  is  to  be 
opened,  the  brasque  must  be  carefully  removed  or  put  aside,  and  the  button  of  cast-iron 
taken  out  and  weighed.  The  brasque  may  sometimes  contain  a  few  gh>bules,  which  must 
be  collected  by  washing  in  water,  or  the  application  of  a  magnetic  bar.  The  quantity 
of  iron  denotes,  of  course,  the  richness  of  the  ore.  These  assays  furnish  always  a  gray 
cast-iron;  and,  therefore,  the  quality  of  the  products  can  hardly  be  judged  of,  except  by 
an  experiment  on  the  large  scale.  The  temperature  necessary  for  the  success  of  an  assay 
is  about  150°  of  Wedgewood. 

In  the  assays  by  the  humid  way,  we  may  expect  to  find  manganese,  silica,  alumina, 
lime,  magnesia,  and  sometimes  carbonic  acid,  associated  with  the  iron.  100  grains  of 
the  ore  in  fine  powder  are  to  be  digested  with  nitro-muriatic-acid ;  which  will  leave  only 
the  silica  with  perhaps  a  very  little  alumina.  If  an  effervescence  takes  place  in  the  cold 
with  a  dilute  acid,  the  loss  of  weight  will  indicate  the  amount  of  carbonic  acid  gas  ex- 
pelled. The  muriatic  solution  contains  the  iron,  the  manganese,  the  lime,  magnesia,  and 
most  of  the  alumina,  with  a  little  silica.  On  evaporating  to  dryness,  and  digesting  in 
water,  all  the  silica  will  remain  in  an  insoluble  state.  If  the  solution  somewhat  acidu- 
lated be  treated  with  oxalate  of  ammonia,  the  lime  will  fall  down  in  the  form  of  an  ox- 
alate ;  ammonia  will  now  precipitate  the  alumina  and  the  oxyde  of  iron  together,  while 
the  manganese  and  magnesia  will  continue  dissolved  in  the  state  of  triple  salts  (ammonia- 
muriates).  The  alumina  may  be  separated  from  the  ferric  oxyde  by  potash-ley.  The 
manganese  may  be  thrown  down  by  hydrosulphuret  of  potash  ;  and,  finally,  the  magnesia 
may  be  precipitated  by  carbonate  of  soda.  100  parts  of  the  red  oxyde  of  iron  contain 
69-34  of  metal,  and  30-66  of  oxygen. 

If  phosphorus  be  present  in  the  ore,  the  nitro-muriatic  solution,  being  rendered  nearly 
neutral,  will  afford  with  muriate  of  lime  a  precipitate  of  phosphate  of  lime,  soluble  in  an 
excess  of  muriatic  acid. 

When  the  sole  object  is  to  learn  readily  the  per-centage  of  iron,  the  ore  maybe  treated 
with  hot  nitro-muriatic,  the  acid  solution  filtered  and  supersaturated  with  ammonia, 
which  will  throw  down  only  the  iron  oxyde  and  alumina  ;  because  the  lime  is  not  pre- 
cipitable  by  that  alkali,  nor  is  magnesia  and  manganese,  when  in  the  state  of  ammonia- 


1066 


mojN. 


muriates.  The  red  y»recipitate,  being  digested  with  some  potash-ley,  will  lose  its  alumina 
and  will  leave  the  ferric  oxyde  nearly  pure.  The  presence  of  sulphur,  pliosphorjs,  oi 
arsenic,  in  iron  ores,  may  always  be  detected  by  the  blowpipe,  or  ustulation  in  the  as^ay 
muffle,  as  described  under  Furnace. 

Of  the  smelting  of  iron  ores. — We  sRall  describe,  in  the  first  place,  the  methods  prac- 
tised in  Great  Britain,  and  shall  afterwards  consider  those  pursued  in  other  countries,  in 
the  treatment  of  their  peculiar  ores. 

Iron  is  divided  into  three  kinds,  according  to  the  different  metallic  states  in  which  it 
may  be  obtained  ;  and  these  are  called  crude  or  cast  iron;  steel;  and  bar  or  mal!eable 
iron.  These  states  are  determined  essentially  by  the  different  proportions  of  charcoal  or 
carbon  held  in  chemical  combination  ;  cast  iron  containing  more  ihan  steel,  and  steel  more 
than  malleable  iron  ;  which  last,  indeed,  ought  to  be  the  pure  metal,  a  point  of  perfec- 
tion, however,  rarely  if  ever  attained.  It  is  impossible  to  assign  the  limits  between  these 
three  forms  of  iron,  or  their  relative  proportions  of  carbon,  with  ultimate  precision  ;  for 
bar  iron  passes  into  steel  by  insensible  gradations,  and  steel  and  cast  iron  make  such 
mutual  transitions  as  to  render  it  difficult  to  define  where  the  former  commences,  and  the 
latter  ceases,  to  exist.  In  fact,  some  steels  may  be  called  crude  iron,  and  some  cast  irons 
may  be  reckoned  among  steels. 

Towards  the  conclusion  of  the  last  century  the  manufacture  of  iron  underwent  a  very 
important  revolution  in  Great  Britain,  by  the  substitution  of  pitcoal  for  charcoal  of 
wood,  the  only  combustible  previously  used  in  smelting  the  ores  of  this  metal.  This 
improvement  served  not  merely  to  diminish  the  cost  of  reduction,  but  it  furnished  a 
softer  cast  iron,  fit  for  many  new  purposes  in  the  arts.  From  this  era,  iron  works  have 
assumed  an  immense  importance  in  our  national  industry,  and  have  given  birth  to  many 
ingenious  and  powerful  machines  for  fashioning  the  metal  into  bars  of  every  form,  with 
almost  incredible  economy  and  expedition. 

The  profusion  of  excellent  coal,  and  its  association  in  many  localities  with  iron-stone, 
have  procured  hitherto  for  our  country  a  marked  superiority  over  all  others  in  the  iron 
trade  ;  though  now  every  possible  effort  is  making  by  foreign  policy  to  rival  or  to  limit 
our  future  operations.  In  1802,  M.  de  Bonnard,  now  divisionary  inspector  in  the  royal 
corps  of  mines  of  France,  and  secretary  of  the  general  council,  made  a  tour  in  England, 
in  order  to  study  our  new  processes  of  manufacturing  iron,  and  published,  on  his  return, 
in  the  Journal  des  Mines,  tom.  17,  a  memoir  descriptive  of  them.  Since  the  peace,  many 
French  engineers  and  iron-masters  have  exerted  themselves  in  naturalizing  in  France 
this  species  of  industry ;  and  M.  de  Gallois,  in  particular,  after  a  long  residence  in  Great 
Britain,  where  he  was  admitted  to  see  deliberately  and  minutely  every  department  of  th< 
iron  trade,  returned  with  ample  details,  and  erected  at  Saint-Etienne  a  lars^e  establish- 
ment  entirely  on  the  English  model.  More  recently,  MM.  Dufrenoy  and  Elie  de  Beau- 
mont,  and  MM.  Coste  and  Perdonnet,  have  published  two  very  copious  accounts  of  their 
respective  metallurgic  tours  in  Great  Britain,  illustrated  with  plans  and  sections  of  our 
furnaces,  for  the  instruction  of  the  French  nation. 

The  argillaceous  carbonate  of  iron,  or  clay  iron-stone  of  the  coal  measures,  is  the  chief 
ore  smelted  in  England.  Some  red  hematite  is  used  as  an  auxiliary  in  certain  works  in 
Cumberland  and  Lancashire ;  but  nowhere  is  the  iron-sand,  or  other  ferruginous  matters 
of  the  secondary  strata,  employed  at  present  for  procuring  the  metal. 

Among  the  numerous  coal-basins  of  England  there  are  two,  in  particular,  which  fur- 
nish more  than  three  fourths  of  the  whole  cast  iron  produced  in  the  kingdom ;  namely, 
the  coal  field  of  Dudley,  in  the  south  of  Staffordshire ;  and  the  coal  fields  of  Monmouth- 
shire, in  South  Wales,  along  with  those  of  Gloucestershire  and  Somersetshire. 

Dudley  is  peculiarly  favored  by  nature.  There  are  found  associated  the  coal,  the 
iron  ore,  the  limestone  for  flux,  and  the  refractory  fire-clay  for  constructing  the  interior 
brick-work  of  the  furnaces.  This  famous  clay  is  mined  at  Stourbridge,  and  exported 
to  every  part  of  the  kingdom  for  making  cast  steel  crucibles  and  glass-house  melting 
pots. 

At  Merthyr-Tydvil,  the  centre  of  the  iron-works  of  Wales,  the  iron-stone  is  extremely 
plentiful,  forming  16  beds,  or  rather  constituting  an  integrant  portion  of  16  beds  of 
slate-clay.  Sometimes  it  occurs  in  pretty  long  tables  adjoining  each  other,  so  as  to 
resemble  a  continuous  stratum;  but  more  frequently  it  forms  nodules  of  various  size  and 
abundance,  placed  in  planes  both  above  and  below  the  coal  seam.  Eight  varieties  of 
ore,  belonsins:  to  different  beds,  have  been  distinguished  by  the  following  barbarous 
names  :  black  balls,  black  pins,  six-inch-wide  vein,  six-inch  jack,  blue  vein,  blue  pins, 
gray  pins,  seven  pins.  The  bed  containing  the  first  quality  of  iron-stone  is  analogous 
to  the  black  ore  of  Staffordshire,  called  gubbin;  it  is  often  cleft  within  like  sept  aria,  and 
its  cavities  are  sometimes  besprinkled  with  crystals  of  carbonate  of  lime  or  quartz.  In 
the  superior  beds  there  are  nodules  decomposing  into  concentric  coats,  of  which  the 
middle  is  clay.     Crystals  of  oxyde  of  titanium  are  occasionally  found  in  the  middle  of 


IRON. 


1067 


the  balls  of  clay  iron-stone ;  to  which  the  metallic  titanium  observed  in  the  inside  of  the 
dome  of  blast  furnaces,  may  be  traced.  Both  at  Dudley  and  South  Wales,  casts  of  shells, 
belonging  to  the  genus  uniOj  are  observed  on  the  iron-stone. 

The  average  richness  of  the  iron-stones  of  South  Wales  is  somewhat  greater  than  that  o^ 
those  of  Staffordshire.  The  former  is  estimated  at  33  parts  of  cast  iron,  while  the  latter 
rarely  exceeds  30  parts  in  100  of  ore  ;  and  this  richness,  joined  to  the  superior  quality  or 
cheapness  of  the  coals,  and  the  proximity  of  the  sea,  gives  South  Wales  a  decided  advan- 
tage  as  a  manufacturing  district. 

The  number  of  blast  furnaces  in  the  parish  of  Merthyr-Tydvil  amounts  to  upwards  of 
30.  The  cast  iron  produced  is,  however,  seldom  brought  into  the  market,  but  is  almost 
entirely  converted  into  bar  iron,  of  which,  at  Mr.  Crawshay's  works,  600  tons  are  manu- 
factured in  a  week.  Numerous  iron  railways,  extending  through  a  length  of  220  miles, 
facilitate  the  transport  of  the  materials  and  the  exportation  of  the  products.  That  con- 
currence of  favorable  circumstances,  which  we  have  noticed  as  occurring  at  Dudley,  pre- 
vails in  an  equal  degree  in  South  Wales. 

The  same  economy  which  the  use  of  coal  has  introduced  into  the  smelting  of  cast  iron 
from  the  ore,  also  extends  to  its  refinery  into  bars.  And  this  process  would  supersede  in 
every  iron  work  the  use  of  wood  charcoal,  were  not  the  iron  produced  by  the  latter  com- 
bustible better  for  many  purposes,  particularly  the  manufacture  of  steel.  In  some  English 
smelting  works,  indeed,  where  sheet  iron  is  prepared  for  making  tin  plate,  a  mixed  refining 
process  is  employed,  where  the  c^t  iron  is  made  into  bar  iron  by  wood  charcoal,  and 
xaminaied  by  the  aid  of  a  coal  fire. 

Till  1740,  the  smelting  of  iron  ores  in  England  was  executed  entirely  with  wood  char- 
coal ;  and  the  ores  employed  were  principally  brown  and  red  hematites.  Earthy  iron  ores 
were  also  smelted ;  but  it  does  not  appear  that  the  clay  iron-stones  of  the  coal-basins 
were  then  used,  though  they  constitute  almost  the  sole  smelting  material  at  the  present 
day.  At  that  era,  there  were  59  blast  furnaces,  whose  annual  product  was  17,350  tons 
of  cast  iron  ;  that  is,  for  each  furnace,  294  tons  per  annum,  and  5|  tons  per  week.  By 
the  year  1788,  several  attempts  had  been  made  to  reduce  iron  ore  with  coked  coal ;  and 
there  re«iained  only  24  charcoal  blast  furnaces,  which  produced  altogether  13,000  tons 
of  cast  iron  in  the  year;  being  at  the  rate  of  546  tons  for  each  per  annum,  or  nearly  11 
tons  per  week.  This  remarkable  increase  of  11  tons  for  5|,  was  due  chiefly  to  the  sub- 
stitution of  cylinder  blowing  machines  worked  with  pistons,  for  the  common  wooden 
bellows.  Already  53  blast  furnaces  fired  with  coke  were  in  activity  ;  which  furnished  in 
toto  48,800  tons  of  iron  in  a  year ;  which  raises  the  annual  product  of  each  furnace  to 
907  tons,  and  the  weekly  product  to  about  17|  tons.  The  quantity  of  cast  iron  produced 
that  year  (1788)  by  means  of  coal,  was  ----__  48,800  tons, 
and  that  by  wood  charcoal,  was         -        -        -        -        .        -        13,100 

Constituting  a  total  quantity  of         -...-.        61,900  tons. 
In  1796,  the  wood  charcoal  process  was  almost  entirely  given  up;  when  the  returns  of 
the  iron  trade  made  by  desire  of  Mr.  Pitt,  for  establishing  taxes  on  the  manufacture 
afforded  the  following  results: — 

121  blast  furnaces,  furnishing  in  whole  per  annum  124,879  tons,  constituting  an  average 
amount  for  each  furnace  of  1032  tons. 

In  1802,  Great  Britain  possessed  168  blast  furnaces,  yielding  a  product  of  about  170,000 
tons;  and  this  product  amounted,  in  1806,  to  250,000  tons,  derived  from  227  coke  fur- 
naces,  of  which  only  159  were  in  activity  at  once.    These  blast  furnaces  were  distributed 
ai  follows. 

In  the  principality  of  Wales         --------52 

In  Staffordshire    -----..-...42 

In  Shropshire      ---------..42 

In  Derbyshire      ----.----..17 

In  Yorkshire -...28 

In  the  counties  of  Gloucester,  Monmouth,  Leicester,  Lancaster,  Cumber- 
land, and  Northumberland         ---...._        ]8 
In  Scotland  ------.....28 

227 

In  .820,  ihe  iron  trade  had  risen  to  the  amount  shown  in  the  following  table: — 

Tons. 

Wales  manufactured,  per  annum  ------- 

Shropshire  and  Staffordshire  ----... 

Yorksliire  and  Derbyshire     ---..-.- 
Scotland,  with  some  places  in  England  ....-- 


150,000 

180,000 

50,000 

20,000 


Total 


400  000 


1068 


IRON. 


IRON. 


1069 


In  a  statistical  view  given  by  M.  de  Villefosse,  of  the  French  and  English  iron  works, 
be  assigns  to  the  latter,  in  1826,  305  blast  furnaces,  distributed  as  follows  : — 

In  the  principality  of  Wales         --------87 

In  Stafi'ordshire    -----------78 

In  Shropshire,  Derbyshire,  Yorkshire,  &c.    -----  84 

In  Scotland  .----------56 

305 

Out  of  these,  280  were  in  activity  at  the  same  time;  and  if  we  suppose  their  mean 
product  to  have  been  50  tons  a  week,  the  total  product  would  have  been,  in  1826,  728,000 
tons.  But  this  estimate  seems  to  be  somewhat  above  the  truth  ;  for,  from  the  information 
communicated  by  Mr.  Philip  Taylor  to  M.  Achille  Chaper,  a  considerable  French  iron- 
master, who,  in  the  summer  of  1826,  inspected  two  thirds  of  the  blast  furnaces  of  Great 
Britain,  their  product  during  this  year  was  about  600,000  tons. 

The  preceding  details  show  the  successive  increments  which  the  manufacture  of  cast 
iron  has  received ;  and  a  similar  progression  has  taken  place  in  its  refinery-  into  wrought 
iron.  This  operation  was  formerly  effected  by  the  agency  of  wood  charcoal  in  refineries 
analogous  to  those  still  made  use  of  in  France.  But  when  that  kind  of  fuel  began  to  be 
scarce  in  this  island,  it  came  to  be  mixed  with  coke  in  various  proportions.  The  bar  iron 
thus  produced  was  usually  hard,  and  required  much  time  to  convert,  so  that  an  establish- 
ment which  could  produce  20  tons  of  bar  iron  in  a  week,  was  deemed  considerable.  At 
that  time,  England  imported  annually  from  Sweden  and  Russia  the  enormous  quantity  of 
70,000  tons  of  iron. 

Mr.  Cort,  to  whom  Great  Britain  is  indebted  for  the  methods  now  pursued  in  this 
country,  succeeded  about  that  time,  after  many  unsuccessful  experiments,  in  converting 
cast  iron  into  bar  iron,  by  exposing  it  on  the  hearth  of  a  reverberatory  furnace  to  the  flame 
of  pitcoal.  This  method,  which  possessed  the  advantage  of  employing  this  species  of  com- 
bustible alone,  likewise  simplified  the  treatment,  because  it  required  no  blast  apparatus. 
But  this  mode  of  refinery,  consisting  in  the  use  of  a  reverberatory  furnace  alone,  did  not 
produce  altogether  the  desired  result.  It  was  irregular;  sometimes  the  loss  of  iron  was 
small,  but  at  others  it  was  very  considerable ;  and  there  were  great  variations  in  the 
quality  of  the  iron,  as  well  as  in  the  quantity  of  fuel  consumed.  Mr.  Cort  succeeded  in 
removing  this  uncertainty  of  result,  by  causing  the  puddling  in  the  reverberatory  furnace 
to  be  preceded  by  a  kind  of  refinery  with  coke.  The  intent  of  this  operation  was  to  de- 
carburate  the  iron,  and  to  prepare  it  for  becoming  malleable.  The  metal  took  in  that  case 
the  name  of  finery  metal,  called,  for  the  sake  of  brevity,  fine-metal. 

He  also  substituted  the  drawing  cylinders  for  the  extension  under  the  hammer,  an  im- 
provement which  accelerated  greatly  the  manufacture  of  bar  iron.  The  iron  then  yielded 
by  the  operation  of  puddling  was  of  a  very  inferior  quality,  and  could  not  be  directly  em- 
ployed in  the  arts.  In  order  to  give  it  more  consistence,  it  was  subjected  to  a  second  heating 
in  a  reverberatory  furnace ;  and  whenever  this  method  had  arrived  at  a  high  enough  de- 
gree of  perfectioir  to  afford  products  fit  for  the  market,  it  became  exclusively  employed  in 
Great  Britain.  This  new  method  of  transforming  cast  iron  into  malleable  iron  speedily 
gained  such  an  extension,  that  of  late  years,  a  single  iron-work,  Cyfartha  in  Wales,  man- 
ufactured annually  more  than  twice  as  much  as  was  made  annually  from  1740  to  1750, 
in  the  whole  kingdom. 

In  surveying  the  improvements  which  the  iron  manufacture  has  received  in  England  in 
the  space  of  the  last  60  years,  they  are  seen  to  be  resolvable  into  two ;  the  first  set  re- 
lating to  the  smelting  of  flie  ores ;  the  other,  to  the  conversion  of  the  pigs  into  bar  iron  j 
hence  naturally  arise  two  heads  under  which  the  subject  of  iron  must  be  treated. 

1.  Manufaciure  of  cast-iron  by  coke  and  coal. — The  cast-iron  produced  by  the  English 
and  Scotch  blast  furnaces  is  in  general  black  and  very  soft ;  but  yet  may  be  distinguished 
into  several  qualities,  of  which  three  are  particularly  noticed. 

No.  1.  Very  black  casMVon,  in  large  rounded  grains,  obtained  commonly  near  the  com- 
mencement of  the  casting,  when  an  excess  of  carbon  is  present ;  in  flowing,  it  appears 
pasty,  and  throws  out  blue  scintillations.  It  exhibits  a  surface  where  crystalline  vegeta- 
tions develop  themselves  rapidly  in  very  fine  branches;  it  congeals  or  fixes  very  slowly; 
its  surface  when  cold  is  smooth,  concave,  and  often  charged  with  plumbago ;  it  has  but  a 
moderate  tenacity,  is  tender  under  the  file,  and  susceptible  of  a  dull  polish.  When  melted 
ovei  again,  it  passes  into  No.  2,  and  forms  the  best  castings. 

No.  2.  Black  cast-iron  has  a  somewhat  lighter  shade  than  the  preceding,  and  may 
ther**fore  on  comparison  be  called  blackish-gray.     It  presents  less  large  granulations  than 
No.  1 ;  is  tenacious,  easily  turned,  filed,  and  polished ;  excellent  for  casting  when  it  ap- 
proaches to  No.  1,  and  for  the  manufacture  of  bar  iron  when  it  has  on  the  contrary  a 
i  shade  somewhat  lighter.    If  repeatedly  melted,  it  passes  into  the  next  quality,  or 

No.  3.  White  cast  iron;  this  is  brittle,  and  indicates  always  some  derangement  in  thi» 


working  of  the  furnace;  it  flows  imperfectly,  and  darts  out,  in  casting,  abundance  of 
brilliant  white  scintillations;  it  fixes  very  quickly ;  and  on  cooling,  exhibits  on  its  surface 
irregular  asperities,  which  make  it  extremely  rough.  It  is  easily  broken,  and  presents  s 
lamellar  and  radiated  fracture ;  and  is  so  hard  that  tempered  steel  cannot  act  upon  ii. 
It  is  cast  only  into  weights,  bullets,  or  bombs,  but  never  into  pieces  of  machmery.  When 
exposed  to  the  refinery  processes,  it  affords  a  bad  bar  iron.  It  is  owing  probably  to  the 
different  nature  of  the  cast  iron  obtained  in  different  counties  in  England,  that  Staflord- 
shire  and  Shropshire  furnish  the  greater  part  of  the  great  iron  castings,  while  Wa  es 
manufactures  almost  exclusively  malleable  iron.  The  lower  price  of  coals  m  Wales 
is  perhaps  the  cause  to  a  certain  extent  of  this  difference  in  the  results  of  these  two  iron 
districts.     It  will  be  interesting,  at  any  rate,  to  describe  separately  the  processes  employed 

in  Staffoidshire  and  Wales.  ,     ^  ^   ,,       t.i  a 

The  blast  furnaces  of  Staffordshire^  in  the  neighborhood  of  Dudley,  Bilston,  and 
Wednesbury,  are  constructed  almost  wholly  of  bricks.  Their  outer  form  is  frequently 
a  cone,  often  also  a  pyramid  with  a  square  base.  They  are  bonnd  about  with  a  great 
many  iron  hoops,  or  with  iron  bars  placed  at  different  heightz.  This  powerful  armor 
allows  the  furnaces  to  be  built  much  less  massively  than  they  formerly  were ;  and  admits 
lighter  and  more  elegant  external  forms.  They  are  seldom  insulated ;  but  are  usually 
associated  to  the  number  of  two  or  three  in  the  same  line.  A  narrow  passage  is  left 
between  them,  which  leads  to  the  lateral  openings  where  the  tuyeres  are  placed.    At  the 


front  of  the  furnace,  a  large  shed  is  always  raised.  The  roofs  of  these  sheds  present  in 
general  circular  profiles,  and  being  made  of  cast  or  bar  iron,  they  display  a  remarkable 
lightness  of  construction.  The  cast  iron  columns  likewise,  which  support  the  joists  and 
girders,  give  additional  elegance. 

In  the  Dudley  field,  the  furnaces  are  almost  always  in  the  middle  of  the  plain,  and  an 
inclined  rail-way  must  be  formed  to  reach  their  platform.  These  inclined  planes,  com- 
posed of  beams  or  rails  placed  alongside  of  each  other,  and  sustained  by  props  and  cross- 
bars, as  indicated  in  fig.  793,  are  set  up  mostly  against  the  posterior  face  of  the  furnace. 
Two'  chains  or  ropes,  passmg  over  the  drums  of  gins,  moved  by  a  steam  engine  (commonly 
the  same  that  drives  the  bellows),  draw  up  the  wagons  of  wood  or  sheet  iron  a  o,  which 
contain  the  various  materials  for  supplying  the  furnace.  To  facilitate  this  service,  the 
platform  round  the  furnace  is  sometimes  enlarged  behind  by  a  floor ;  while  a  balustrade, 
which  opens  when  the  wagons  arrive  at  the  platform,  prevents  accidents.  This  pro- 
jection is  occasionally  covered  by  a  roof.  For  a  furnace  of  the  largest  size,  the  force  ex- 
pc:nded  by  this  lifting  apparatus  is  not  more  than  a  two-horse  power. 

Fig.  793  is  a  vertical  section  through  the  furnace  from  front  to  rear,  or  at  right  angles 
to  the  line  of  the  lateral  tuyeres.  The  erection  of  a  pair  of  blast  furnaces,  of  40  feet 
high  each,  costs,  in  the  Dudley  district,  1800  pounds  sterling ;  and  requires  for  building 
each,  160,000  common  bricks  for  the  outside  work,  3900  fire-bricks  for  the  lining  or  shirt 
of  the  furnace,  and  825  for  the  boshes.  The  dimensions  of  the  fire-bricks  are  various;  5 
kinds  are  emidoyed  for  the  lining,  and  9  kinds  for  the  boshes.  They  are  all  6  inches 
thick,  and  are  curved  to  suit  the  voussoirs. 

The  number  of  charges  given  in  12  hours  is  different  in  different  furnaces ;  being 
sometimes  20,  25,  and  even  so  high  as  40;  but  ^0  is  a  fair  average.    Each  charge  is 


IRON. 


1071 


1070 


iROW. 


composed  of  from  5  to  6  cwts.  of  coke,  (or  now  of  3  to  4  cwts.  of  coal  with  the  hot  blast)  j 
3,  4  and  sometimes  6  cwts.  of  the  roasted  mine,  according  to  its  richness  and  the  quality 
of  cast  iron  wanted;  the  limestone  flux  is  usually  one  third  of  the  weight  of  the  roasted 
iron  stone.    There  are  2  casts  in  24  hours ;  one  at  6  in  the  morning,  and  another  at  6  in 

the  evenin". 

The  height  of  the  blast  furnaces  is  veiy  variable;  some  being  only  36  feet  high 
including  the  chimney,  while  others  have  an  elevation  of  60  feet.  These  extreme  limits 
are  very  rare :  so  that  the  greater  part  of  the  furnaces  are  from  45  to  50  feet  high. 
They  are  all  terminated  by  a  cylindrical  chimney  of  from  8  to  12  feet  long;  being  about 
one  fifth  of  the  total  height  of  the  furnace.  The  inside  diameter  of  this  chimney  is  the 
same  as  that  of  the  throat  or  mouth  ;  and  varies  from  4  to  6  feet.  The  chimney  is  fre- 
quently formed  of  a  single  course  of  bricks,  and  acquires  solidity  from  its  hoops  of  iron, 
so  thickly  placed  that  one  half  of  the  surface  is  often  covered  with  them.  At  its  lower 
end,  the  mouth  presents  one  or  two  rectangular  openings,  through  which  the  charge  is 
?iven.  It  is  built  on  a  basement  circle  of  casi-iron,  which  forms  the  circumference  of  the 
throat ;  and  a  sloping  plate  of  cast-iron  6  is  so  placed  as  to  make  the  materials  slide  ov-r 
into  the  furnace,  as  shown  in  the  figure. 

The  insiie  of  the  blast  furnaces  of  Staffordshire  is  most  frequently  of  a  circular  form, 
except  the  hearth  and  working  area.  The  inner  space  is  divided  into  four  portions,  different 
in  their  forms,  and  the  functions  which  they  fulfil  in  the  smelling  of  the  ore. 

The  undermost,  called  the  hearth,  or  crucible,  in  which  the  cast-iron  collects,  is  a  right 
rectangular  prism,  elongated  in  a  line  prependicular  to  the  axes  of  the  tuyeres.  The 
5ides  of  the  hearth  consist  in  general  of  refractory  sandstone  (fire-stone),  obtained  mostly 
"rom  the  bed  of  the  coal  basin,  called  millstone  grit ;  and  the  bottom  of  the  hearth  is  form- 
2d  of  a  large  block  of  the  same  nature,  laid  on  a  cast-iron  plate. 

The  second  portion  is  also  made  of  the  same  refractory  grit  stone.     It  has  the  form  of 

quadrangular  pyramidal,  approaching  considerably  to  a  prism,  from  the  smallness  of  the 
ingle  included  between  the  sides  and  the  aj^s. 

The  third  portion  or  lower  body  of  the  furnace  is  conical,  but  here  the  interior  space 
suddenly  expands ;  the  slope  outwards  at  this  part  seems  to  have  a  great  influence  on 
the  quality  of  the  cast-iron  obtained  from  the  furnace.  When  No.  2  of  the  blackest  kind 
is  wanted  for  castings,  the  inclination  of  this  cavity  of  the  furnace  is  in  general  less 
considerable  than  when  No.  2  cast  iron  for  conversion  into  bar  iron  is  required.  The 
inclination  of  this  conical  chamber,  called  the  boshes,  varies  from  55  to  60  degrees  with  the 
iorizon.  The  diameter  of  this  part  is  equal  to  that  of  the  belly,  and  is  from  11  to  13  feet. 
The  boshes  are  built  of  masonry,  as  shown  in  Jigs,  794,  795. 

794 


The  fourth  part,  which  constitutes  about  two  thirds  of  the  height  of  the  furnace  from 
the  base  of  the  hearth  up  to  the  throat,  presents  the  figure  of  a  surface  of  revolution, 
generated  by  a  curve  whose  concavity  is  turned  towards  the  axis  of  the  furnace,  and 
Those  last  tangent  towards  the  bottom  is  almost  vertical.  This  surface  is  sloped  off  with 
that  of  the  boslies  (etalages  in  French),  so  that  no  sharp  angle  may  exist  at  the  belly. 
In  some  furnaces  of  considerable  dimensions,  as  in  that  with  three  tuyeres,  this  portion  of 
the  furnace  is  cylindrical  for  a  certain  height. 


The   following   measurements    represent  the   interior  structure  of  two   well-going 
farnaees. 


Height  from  the  hearth  to  the  throat  or  mouth 
Height  of  the  crucible  or  hearth 

—  of  the  boshes  _  -  - 

—  of  the  cone        .  -  -  ■ 

—  of  the  chimney  or  mouth    - 
Width  of  the  bottom  of  the  hearth 

Ditto  at  its  upper  end         .  -  - 

Ditto  of  the  boshes       .  -  - 

Ditto  at  one  third  of  the  belly 

Ditto  at  two  thirds  of  ditto 

Ditto  at  the  mouth  _  -  - 

Inclination  of  the  boshes  -  * 


No.  1. 


No.  2. 


Feet. 

45 

6i 

8 

30^ 

8 

3 

12f 
12 

8f 

4| 

59° 


Feet. 
49 

6 

7 
36 
12| 

2 

2f 
13i 

Uh 
9k 
3f 

52° 


The  conical  orifice  called  the  tuydre,  in  which  ihe  tapered  pipes  are  placed,  for  impart 
ing  the  blast,  is  seen  near  the  bottom  of  the  furnace,  yjg.  794,  at  a.    Nose  tubes  of  va- 
rious  sizes,  from  2  to  4  inches  in  diameter,  are  applied  to  the  extremity  of  the  main 
blast-pipe.    Under  a  is  the  bottom  of  the  hearth,  which,  in  large  furnaces,  may  be  two 
feet  square,     b  is  the  top  of  the  hearth,  about  two  feet  six  inches  square,     a  b  is  the 
height  of  the  hearth,  about  six  feet  six  inches,    b  shows  the  round  bottom  of  the  conical 
or  funnel  part,  called  in  this  country  the  boshes,  standing  upon  the  square  area  of  the 
hearth      c  is  the  top  of  the  boshes,  which  may  b6  about  12  feet  in  diameter,  and  8  leet 
in  perpendicular  height,    d  is  the  furnace  top  or  mouth  {gueulard  in  French),  at  which 
ihe  materials  are  charged.    It  may  be  4^  feet  in  diameter.     The  line  between  c,  d  is  the 
hei«'ht  of  the  internal  cavity  of  the  furnace,  from  the  top  of  the  boshes  upwards,  sup- 
•posed  to  be  30  feet,     a,  d,  is  the  total  height  of  the  interior  of  the  furnace,  reckoned  at 
44i  feet      e  e  is  the  lining,  which  is  built  in  the  nicest  manner  with  the  best  fire- bricks, 
from  12  to  14  inches  long,  3  inches  thick,  and  curved  to  suit  the  circle  of  the  cone.     A 
vacancy  of  3  inches  wide  is  lefl  all  round  the  outside  of  the  first  lining  by  the  builder; 
which  is  sometimes  filled  with  coke  dust,  but  more  generally  with  sand  firmly  rammed. 
This  void  space  in  the  brick -work  is  for  the  purpose  of  allowing  for  any  expansion  which 
mieht  occur,  either  by  an  increase  in  the  bulk  of  the  building,  or  by  the  pressure  and 
weight  of  the  materials  when  descending  to  the  bottom  of  the  furnace.     Exterior  to  e  e 
is  a  second  lining  of  fire-bricks  similar  to  the  first.     At  f,  on  either  side,  is  a  cast-iron 
lintel  8i  feet  long,  by  10  inches  square,  upon  which  the  bottom  of  the  arches  is  sup- 
ported. %,  G,  is  the  rise  of  the  tuyere  arch,  which  may  be  14  feet  high  upon  the  outside, 
and  18  feet  wide.    The  extreme  size  of  the  bottom  or  sole  of  the  hearth,  upon  each 
side  of  A,  may  be  10  feet  square.    This  part  and  the  boshing  stones  are  preferably  made 
from  a  coarse  sandstone  grit,  containing  large  rounded  grains  of  quartz,  united  by  a  sili- 

ceo-argillaceous  cement.  • ,       ..  »  v        .v 

The"  bottom  of  the  hearth  consists,  first,  of  a  course  of  the  said  gritstone ;  beneath 

which  is  a  layer  of  bedding  sand,  having,  in  its  under 
part,  passages  for  the  escape  of  the  vapors  generated 
by  damps;  the  whole  being  supported  upon  pillars  of 
brick. 

Fig.  795  represents  the  hearth  and  boshes,  m  a 
vertical  side  section,  a  is  the  lymp  stone,  and  b  the 
tymp  plate  for  confining  the  liquid  metal  in  the  hearth. 
The  latter  is  wedged  firmly  into  the  side- walls  of  the 
hearth;  c  is  the  dam-stone,  which  occupies  the  whole 
breadth  at  the  bottom  of  the  hearth,  excepting  about  6 
inches,  which  space,  when  the  furnace  is  at  work,  is 
filled,  before  every  cast,  with  a  strong  binding  sand. 
This  stone  is  faced  outside  by  a  cast-iron  plate  d,  called 
the  dam-plate,  of  considerable  thickness,  and  peculiar 
shape.     The  top  of  the  dam-stone,  or  rather  the  notch 

,, of  the  dam-plate,  lies  from  4  to  8  inches  under  the 

level  of  the  tuyere  hole.  The  space  under  the  tymp  plate,  for  5  or  6  inches  down  is 
rammed  full,  for  every  cast,  with  strong  loamy  earth,  or  even  fine  clay ;  a  process  called 
tTTymp  stopping.    The  area  of  the  base  of  this  furnace  being  38  feet,  its  extreme 

**^The  blast  tVimaces  of  Staffordshire  have  always  two  tuyeres,  at  least,  placed  on  opp<> 


I 


1072 


IRON. 


IRON. 


1073 


«ite  sides,  but  so  pointed  that  the  blast  may  not  pursue  directly  opposite  lines.  In  a  furnace 
acting  well  in  the  neighborhood  of  Dudley,  the  one  of  the  tuyeres  was  10  inches  distant 
from  the  posterior  wall  of  the  hearth,  and  the  other  only  four  inches.  In  other  furnaces 
with  3  tuyeres,  the  side  ones  are  placed,  the  one  16|  inches,  and  the  other  6|  inches 
from  the  back.  Three  tuyeres  are  seldom  made  to  blow  simultaneously.  The  third  is 
brought  into  action  only  when  the  furnace  seems  to  be  choked  up,  and  when  it 
becomes  necessary  to  clear  it  up  by  a  powerful  concussion.  Too  much  pains  cannot  be 
bestowed  on  the  masonry  and  brickwork  of  a  blast  furnace,  and  on  the  solidity  of  its 
foundation.  In  a  soft  ground  it  should  rest  on  piles,  so  driven  that  the  channel  left 
beneath  for  the  drainage  of  the  building  may  be  above  any  water  level.  Small  passages 
should  likewise  be  left  throughout  the  body  of  the  work,  for  the  transpiration  of  moisture. 

The  blowing  machines  employed  in  Staffordshire  are  generally  cast-iron  cylinders,  in 
which  a  metallic  piston  is  exactly  filled  as  for  a  steam  engine,  and  made  in  the  same 
way.  Towards  the  top  and  bottom  of  the  blowing  cylinders  orifices  are  left  covered 
with  valves,  which  open  inside  when  the  vacuum  is  made  with  the  cylinders,  and  after- 
wards shut  by  their  own  weight.  Adjutages  conduct  into  the  iron  globe  or  chest,  the  air 
expelled  by  the  piston,  both  in  its  ascent  and  descent ;  because  these  blowing  machines 
have  always  a  double  stroke. 

The  pressure  of  the  air  is  made  to  vary  through  a  very  considerable  range,  according 
to  the  nature  of  the  fuel  and  season  of  the  year ;  for  as  in  summer  the  atmosphere  is 
more  rarefied,  it  must  be  expelled  with  a  compensating  force.  The  limits  are  from  Ij 
pounds  to  3 1  pounds  on  the  inch;  but  these  numbers  represent  extreme  profKirtions,  the 
average  amount  in  Staffordshire  being  3  pounds.  With  this  pressure  a  furnace  usually 
works,  which  affords  60  tons  of  cast-iron  in  the  week  ;  and  the  pressure  may  be  2J  pounds 
on  an  average.  The  orifices,  or  nose-pipes,  through  which  the  air  issues,  also  vary  with 
the  nature  of  the  coke  and  the  ore.  In  Stafibrdshire  they  are  generally  from  2  inches  and 
5  tenths  to  2  inches  and  8  tenths  in  diameter. 

The  blowing  machines  of  Slaffordshire  are  always  impelled  by  steam  engines.  At  Mr. 
Bagnall's  works,  two  blast  furnaces,  40  feef  high,  exclusive  of  the  chimney  or  top,  and 
two  finery  furnaces,  are  worked  by  a  steam  engine  of  40  horses  power ;  and  therefore 
the  power  of  one  horse  corresponds  to  the  production  of  2^  tons  of  cast  iron  per  week, 
independently  of  the  finery. 

In  South  Wales,  especially  at  Ponlypool,  there  are  slighter  blast  furnaces,  whose  upper 
portion  is  composed  of  a  single  range  of  bricks,  each  cf  which  is  20  inches  long,  4  thick, 
and  9  broad.  The  interior  of  the  chimney  represents  an  inverted  cone.  These  furnaces 
derive  solidity,  and  power  to  resist  the  expansions  and  contractions  from  change  of  tem- 
perature, by  being  cased,  as  it  were,  in  horizontal  hoops,  placed  3  feet,  or,  even  in  some 
cases,  only  6  inches  asunder.  These  flat  rings  consist  of  four  pieces,  which  are  joined 
by  means  of  vertical  bars,  that  carry  a  species  of  ears  or  rings,  into  which  the  hoops  enter^ 
and  are  retained  by  bolts  or  keys.  Instead  of  these  ears,  screw  nuts  are  also  employed 
for  the  junction.  Each  hoop  is  alternately  connected  to  each  of  the  eight  vertical  bars. 
The  interior  of  these  furnaces  is  the  same  as  of  the  others ;  being  generally  from  12  to 
14  feet  diameter  at  the  belly,  and  from  50  to  55  feet  high.  Though  slight,  they  last  as 
long  as  those  composed  of  an  outer  body  of  masonry  and  a  double  lining  of  bricks;  and 
have  continued  constantly  at  work  for  three  years.  In  Wales  also  the  blast  furnaces  are 
generally  somewhat  larger  than  in  Staffordshire ;  because  there  the  object  being  to  refine 
the  cast  iron,  they  wish  to  procure  as  large  a  smelting  product  as  possible.  But  in  Staf- 
fordshire, a  fine  quality  of  casting  iron  is  chiefly  sought  after,  and  hence  their  furnaces 
have  less  height,  but  nearly  the  same  width. 

In  a  blast  apparatus  employed  at  the  Cyfartha  works,  moved  by  a  90  horse  steam 
power,  the  piston  rod  of  the  blowing  cylinder  is  connected  by  a  parallelogram  mechanism 
with  the  opposite  end  of  the  working  beam  of  the  steam  engine.  The  cylinder  is  9  feet 
4  inches  diameter,  and  8  feet  4  inches  high.  The  piston  has  a  stroke  8  feet  long,  and  it 
rises  13  times  in  the  minute.  By  calculating  the  sum  of  the  spaces  percurred  by  Ihe 
piston  in  a  minute,  and  supposing  that  the  volume  of  the  air  expelled  is  equal  to  only  96 
per  cent,  of  that  sum,  which  must  be  admitted  to  hold  with  machines  executed  with  so 
much  precision,  we  find  that  12,588  cubic  feet  of  air  are  propelled  every  minute.  Hence 
a  horse  power  applied  to  blowing  machines  of  ihis  nature  gives,  on  an  average,  137  cu- 
bic feel  of  air  per  minute.  The  pressure  on  the  air,  as  it  issues,  rarely  exceeds  two  pounds 
on  the  square  inch  in  the  Welsh  works. 

At  the  establishment  of  Cyfartha,  for  blowing  seven  smelting  furnaces,  and  the  seven 
corresponding  fineries,  three  steam  engines  are  employed,  one  of  90  horse  power, 
another  of  80,  and  a  third  of  40 ;  which  constitutes  in  the  whole  a  force  of  210  horses, 
or  26  horses  and  l  per  funiacCy  supposing  the  fineries  to  consume  one  eighth  of  the  blast. 
In  the  whole  of  the  works  of  Messrs.  Crawshay,  the  proprietors  of  Cyfartha,  the  power 
of  about  350  horses  is  expended  in  blowing  12  smelting  furnaces,  and  their  subordinate 
fineries  ;  which  gives  from  25  to  26  horses  for  each,  allowing  as  before  one  eighth  for  the 
fineries.     As  *hese  furnaces  produce  each  about  60  tons  of  cast  iron  weekly,  we  find 


ihat  a  horse  power  corresponds  to  2  tons  and  a  tenth  in  that  time.  Each  of  the  furnaces 
consumes  about  3567  cubic  feet  of  air  per  minute.  These  works  have  been  greatly 
increased  of  late  years. 

The  following  analyses  of  the  English  coal  ironstones  have  been  made  by  M.  Berthier, 
at  the  school  of  mines  in  Paris. 

\ 


Loss  by  ignition  - 
Insoluble  residuum 
Lime  -  -  - 
Peroxyde  of  iron  - 


Rich  Welsh  Ore. 


30-00 
8-40 
0-0 

60-00 


Poor  Welsh  Ore. 


I 


2700 

22-03 

600 

42-66 


Rich  Ore  of  Dudley,  i 
or  gubbin. 


21  00 
7-66 
2-66 

58-33 


On  calculating  the  quantities  of  carbonate  of  iron,  and  metallic  iron,  to  which 
above  peroxyde  corresponds,  we  have : — 


the  ' 


Carbonate  of  iron 
Metallic  iron 


88-77 
42-15 


65-09 
31-38 


85-20 
40-45 


The  mean  richness  of  the  ores  of  carbonate  of  iron  of  these  coal  basins  is  not  far  from 
33  per  cent.  About  28  per  cent,  is  dissipated  on  an  average,  in  the  roasting  of  the  ores. 
Eveiy  ferruginous  clay-stone  is  regarded  as  an  iron  ore,  when  it  contains  more  than  20 
per  cent,  of  metal ;  and  it  is  paid  for  according  to  its  quality,  being  on  an  average  at  12 
shillings  per  ton  in  Staffordshire.  The  gubbin,  however,  fetches  so  high  a  price  as  16 
tx  ^7  shillings.  The  ore  must  be  roasted  before  it  is  fit  for  the  blast  furnace,  a  process 
cauied  on  in  the  open  air.  A  heap  of  ore  mingled  with  small  coal  (if  necessary)  is 
piled  up  over  a  stratum  of  larger  pieces  of  coal;  and  this  heap  may  be  6  or  7  feet  high, 
by  15  or  20  broad.  The  fire  is  applied  at  the  windward  end,  and  after  it  has  burned  a 
certain  way,  the  heap  is  prolonged  at  the  other  extremity,  as  far  as  the  nature  of  the 
ground  or  convenience  of  the  work  requires.  The  quantity  of  coal  requisite  for  roasting 
the  ore  varies  from  one  to  four  hundred  weight  per  ton,  according  to  the  proportion  of 
bituminous  matter  associated  with  the  iron-stone.  The  ore  loses  in  this  operation  from 
25  to  30  per  cent,  of  its  weight.  Three  and  a  quarter  tons  of  crude  ore,  or  two  and  a 
quarter  tons  of  roasted  ore,  are  required  to  produce  a  ton  of  cast-iron ;  that  is  to  say,  the 
crude  material  yields  on  an  average  30-7  per  cent.,  and  the  roasted  ore  44-4  of  pig  metal. 
In  most  smelting  works  in  Staffordshire,  about  equal  weights  of  the  rich  ore  in  round 
nodules  called  gtlk>m,  and  the  poorer  ore  in  cakes  called  blue  fiat,  are  employed  together 
in  their  roasted  state ;  but  the  proportions  are  varied,  in  order  to  have  a  uniform  mix- 
ture, capable  of  yielding  from  30  to  33  per  cent,  of  metal. 

The  transition  or  carboniferous  limestone  of  Dudley  is  used  as  the  flux ;  it  is  compact 
and  contains  little  clay.  The  bulk  of  the  flux  is  made  nearly  equal  to  that  of  the  ore. 
To  treat  two  tons  and  a  quarter  of  roasted  ore,  which  furnish  one  ton  of  pig  iron,  19 
hundred  weight  of  limestone  are  employed ;  constituting  nearly  1  of  limestone  for  3  of 
unroasted  ore.    The  limestone  costs  6  shillings  the  ton. 

Carbonized  pitcoal  or  coke  was,  till  within  these  few  years,  the  sole  combustible  used 
in  the  blast  furnaces  of  Slaflfordshire. 

The  coal  is  distributed  in  circular  heaps,  about  5  feet  diameter,  by  4  feet  high ;  and 
the  middle  is  occupied  by  alow  brick  chimney,  piled  with  loose  bricks, so  open  as  to  leave 
interstices  between  them,  especially  near  the  ground.  The  larger  lumps  of  coal  are 
arranged  round  this  chimney,  and  the  smaller  towards  the  circumference  of  the  heap. 
When  every  thing  is  adjusted,  a  kindling  of  coals  is  introduced  into  the  lx4toro  of  the 
brick  chimney ;  and  to  render  the  combustion  slow,  the  whole  is  covered  over  with  a  coat 
of  coal  dross,  the  chimney  being  loosely  closed  with  a  slab  of  any  kind.  Openings  are 
occasionally  made  in  the  crust  and  afterwards  shut  up,  to  quicken  and  retard  the  ignition 
at  pleasure,  during  its  continuance  of  24  hours.  Whenever  the  carbonization  has  reached 
the  proper  point  for  forming  good  coke,  the  covering  of  coal  dross  is  removed,  and  water 
is  thrown  on  the  heap  to  extinguish  the  combustion ;  a  circumstance  deemed  useful  to 
the  quality  of  the  coke.  In  this  operation  the  Staffordshire  coal  loses  the  half  of  its 
weight,  or  two  tons  of  coal  produce  one  of  coke. 

As  soon  as  the  blast  furnace  gets  into  a  regular  heat,  which  happens  about  15  days  or 
three  weeks  after  fires  have  been  put  in  it,  the  working  consists  simply  in  charging  it,  at 
the  opening  in  the  throat,  whenever  there  is  a  sufficient  empty  space;  the  only  rule 
being  to  keep  the  furnace  always  full.  The  coke  is  measured  in  a  basket,  thirteen  of 
which  go  to  the  ton.  The  ore  and  the  flux  (limestone)  are  brought  forwards  in  wheel- 
barrows of  sheet  iron.  In  24  hours,  there  are  thrown  into  a  furnace  such  as  y/g. 
582,  14|  tons  of  coke,  16  tons  of  roasted  ore,  and  6f  tons  of  limestone;  from  which 
about  7  tons  of  pig  iron  are  procured.  This  is  run  ofl'  every  12  hours;  in  some  works 
the  blast  is  suspended  during  the  discharge.    The  metal  intended  to  be  converted  into 


•/I 


1074 


IRON. 


bar  iron,  or  to  be  cast  again  into  moulds,  is  ran  into  small  pigs  3  feet  long,  and  4  inches 
diameter :  weighing  each  about  2  hundred  weight  and  a  half. 

The  disorders  to  which  blast  furnaces  are  liable  have  a  tendency  always  to  produce 
while  cast-iron.  The  color  of  the  slag  or  scoriae  is  the  surest  test  of  these  derange- 
ments,  as  it  indicates  the  quality  of  the  product..  If  the  furnace  is  y/^lding  an  iron 
nrone^  for  casting  into  moulds,  the  slag  has  a  uniform  vitrification,  and  is  slishtly  trans- 
lucid  When  the  dose  of  ore  is  increased  in  order  to  obtain  a  gray  pig  iron,  fat  lor 
fabrication  into  bars,  the  slag  is  opaque,  dull,  and  of  a  greenish-yellow  tint,  with  blue 
enamelled  zones.  Lastly,  when  the  furnace  is  producing  a  white  metal,  the  slags  are 
black,  glassy,  full  of  bubbles,  and  emit  an  odor  of  sulphureted  hydrogen.  The  scoriSB 
from  k  coke  are  much  more  loaded  with  lime  than  those  from  a  charcoal  blast  furnace. 
This  excess  of  lime  appears  adapted  to  absorb  and  carry  off  the  sulphur,  which  would 
otherwise  injure  the  quality  of  the  iron.    The  slags,  when  breathed  on,  emit  an  argiUa- 

*^T  blast  furnace  of  50  or  60  feet  in  height  gives  commonly  from  60  to  70  tons  of  cast- 
iron  per  week;  one  from  50  to  55  feet  high,  gives  60  tons ;  two  united  of  4o  feet  produce 
together  100  tons ;  and  one  of  36  feet  furnishes  from  30  to  40.  A  blast  furnace  should 
go  for  four  or  five  years  without  needing  restoration.  From  31  to  4  tons  of  coal,  inclu- 
sive of  the  coal  of  calcination,  are  required  in  Staffordshire  to  obtain  one  ton  of  cast-iron; 
and  the  expense  in  workmen's  wages  is  about  15  shillings  on  that  quantity. 

At  the  Cyfartha  works  of  Messrs.  Crawshay  in  South  Wales,  the  average  price  of  the 
lithoid  carbonate  of  iron,  ready  for  roasting,  is  only  7^.  6d.  a  ton,  and  its  richness  is  about 
33  per  cent.     The  furnaces  for  roasting  the  ore  in  that  country  are  made  in  the  lorm  ol 
cylinders,  placed  above  an  inverted  cone.     The  cylindrical  part  is  6  feet  high  and  wide, 
and  the  cone  is  about  4  feet  high,  with  a  base  equal  to  that  of  the  cylinder;  towards 
the  bottom  or  narrowest  part  of  the  inverted  cone,  there  is  an  aperture  which  terminates 
in  an  outlet  on  a  level  with  the  bottom  of  the  terrace  in  which  the  furnace  is  built. 
Sometimes,  however,  all  the  roasting  furnaces  are  in  a  manner  combined   into  one, 
which  resembles  a  long  pit  about  6  feet  in  width  and  depth,  and  whose  botiom  presents 
a  series  of  inverted  hollow  quadrangular  pyramids,  6  feet  in  each  side,  and  4  deep,     ine 
bottom  or  apex  of  each  of  these  pyramids  communicates  with  a  mouth  or  door-way  that 
opens  on  a  lower  terrace,  through  which  the  ore  falls  in  proportion  as  it  is  roasted ;  and 
whence  it  is  wheeled  and  tumbled  into  the  throat  of  an  adjoining  blast  furnace,  on  the 
same   level   with   the  terrace;   for  in  Wales  the  blast  furnace  is  generally   built  up 
against  the  face  of  a  hill,  which  makes  one  of  its  fronts.    The  above  roasting  fur- 
naces, which  closely  resemble  lime-kilns,  after  being  filled  with  alternate  strata  of  small 
coal  and  ore,  are  set  on  fire;  and  the  roasted  ore  is  progressively  withdrawn  below,  as 

already  mentioned.  •    -117  i      ♦v-..  :«  c»«r 

The  product  of  coke  from  a  certain  weight  of  coal  is  greater  m  Wales  than  in  btal- 
fordshire,  though  the  mode  of  manufacture  is  the  same.  At  Pen-y-Darran,  for  example, 
5  of  coal  furnish  3|  of  coke;  or  100  give  70 ;  at  Dowlais  100  of  coal  afford  71  of  coke, 
and  the  product  would  be  still  greater  if  more  pains  were  bestowed  upon  the  Process. 
At  Dowlais,  coal  costs  only  2  shillings  a  ton ;  at  Cyfartha,  it  is  worth  from  25.  6d.  to  5 
shillings.     About  2  tons  of  coke  are  employed  in  obtaining  1  ton  of  cast-iron. 

According  to  M.  Berthier's  analysis,  the  slag  or  cinder  of  Dowlais  consists  of  silica, 
40-4;  lime;38-4;  magnesia,  5-2;  alumina,  11-2;  protoxyde  of  iron,  3-8  ;  and  a  trace  of 
sulphur.  He  says  that  the  silica  contains  as  much  oxygen  as  all  the  other  bases  united ; 
or  is  equivalent  to  them  in  saturating  power ;  and  to  the  excess  of  hme  he  ascribes  the 
freedom  from  sulphur,  and  the  good  quality  of  the  iron  produced.  The  specimen  exam- 
ined was  from  a  furnace  at  Merthyr-Tydvil.  Other  slags  from  the  same  furnace,  and  one 
from  Dudley,  furnished  upwards  of  2  per  cent,  of  manganese.  Those  which  he  analyzed 
from  Saint  Etienne,  in  France,  afforded  about  1  per  cent,  of  sulphur. 

The  consumption  of  coal  in  the  Welsh  smelting  furnaces  may  be  estimated,  on  an 
average,  at  3  Ions  per  ton  of  cast-iron  ;  corresponding  to  2-1  of  their  coke,  from  this 
economy  in  the  quantity  of  fuel,  as  well  as  from  its  cheapness  and  that  of  the  iron  ore, 
the  iron  of  South  Wales  can  be  brought  into  the  market  at  a  much  lower  rate  than  that 
of  any  other  district.  These  blast  furnaces  remain  in  action  from  5  to  10  years ;  at  the 
end  of  which  time,  only  their  interior  surface  has  to  be  repaired.  The  lining  of  the 
upper  part  lasts  much  longer;   for  examples  are  not  wanting  of  its  holding  good  tor 

nearly  40  years.  .  r    .       • 

One  of  the  greatest  improvements  ever  made  by  simple  means  m  any  manufacture  is 
the  employment  of  hot  air,  instead  of  the  ordinary  cold  air  of  the  atmosphere,  in  supply- 
in**  the  blast  of  furnaces  for  smelting  and  founding  iron.  The  discovery  of  the  supe- 
rior power  of  a  hot  over  a  cold  blast  in  fusing  refractory  lumps  of  cast-iron  was  acci- 
dentallv  observed  by  my  pupil,  Mr.  James  Beaumont  Neilson,  engineer  to  the  Glasgow 
gas  wo'rks,  about  the  year  1827,  at  a  smith's  forge  in  that  city,  and  it  was  made  the 
subject  of  a  patent  in  the  month  of  September  of  the  following  year.  No  particular 
construction  of  apparatus  was  described  by  the  inventor  by  which  the  a'x  was  to  be 


IRON. 


1075 


heaed,and  conveyed  to  the  furnace;  but  it  was  merely  staled  that  the  air  may  be 
heated  in  a  chamber  or  closed  vessel,  having  a  fire  under  it,  or  in  a  vessel  connect«l  S 
any  convenient  manner  with  the  forge  or  furnace.  From  this  ve«el  thrair  is  to  be  forr^H 
by  means  of  bellows  info  the  furnace.     The  quantity  of  surfaev^i  ha  hea  in  <>  fur  nte^ 

JXt che^%t  '/"''f' ''  '^"'  '^?  ""^i*^  'l'""'' '  ^''  ^  ^"P«^^  furnace,  about  "(^ 
cubic  inches.  The  vessel  may  be  enclosed  in  brickwork,  or  fixed  in  any  other  mainer 
that  may  be  found  desirable,  the  application  of  heated  air  in  «y  way  ^o  furnaces  S 

Wherever  a  forced  stream  of  air  is  employed  for  combustion,  the  resulting  temperature 
must  evidently  be  impaired  by  the  coldness  of  the  air  injected  upon  theS  The  heH 
developed  in  combustion  is  distributed  into  three  portions ;  one  is  commri'cated  to  the 
fatTirn"!.^"^''  T'^:i ''  .^^""^^"i^^ted  to  the  azote  of  the  atm^eTeTand  to  the  v^ 
^tile  products  of  coirfbustion,  and  a  third  to  the  iron  and  fluxes,  ir  other  .urroundi^^ 
nW -n'  \^^''''^^'^'  dissipated  by  wider  diffusion.  This  inevi\ableXributLn  taief 
place  in  such  a  way,  that  there  is  a  nearly  equal  temperature  over  the  whole  extent  of  a 
fire-place,  m  which  an  equal  degree  of  combustion  exists. 

We  thus  perceive  that  if  the  air  and  the  coal  be  very  cold,  the  portions  of  hp«»  «K- 
sorbed  by  them  might  be  very  considerable,  and  sufficient  TpVeveiL^the  re.ultf^^^^ 
peraturefrom  rising  to  a  proper  pitch;  but  if  they  were  veryTo^.^ey  wrulHbsort 
ess  caloric,  and  won  d  leave  more  to  elevate  the  common  temperature  L^  us  sup ^sc 
tTeo^h  r^  chargea  with  burning  fuel,  into  one  of  which  cold  air  is  blown,  and  S 
the  other  hot  air  m  the  same  quantity.     In  the  same  time,  nearly  equal  quanth  es  of  fud 

^^'re  wm"'T>f^  T'^  ^  ""5''^y  "^"^^  production  of  heat ;  but  notlithS  n  '  of  this 
there  will  not  be  the  same  degree  of  heat  in  the  two  fu;naces,  for  the  one  which  re' 
ceives  the  hot  air  will  be  hotter  by  all  the  excess  of  heat  in  its  air  above  that  of  the" 

we  to  STa'ine  th'Tr  •"•'  ?'''  V'f  '^^^  "^"^  ^^^  >^«^^  ^^^^-^»«  ?rom  it      Nor  ^l 
we  to  imagine  that  by  injecting  a  little  more  cold  air  into  the  one  furnace,  we  can  raise 

^heTme  ti^JV';'/  T  l^"  .  '^''''  "^''^  ^^^  ^"^-^^  ^^  should  bur^ more  co^ 
in  the  same  time,  and  we  should  produce  a  greater  quantity  of  heat,  but  this  heat  being 
diffused  proportionally  among  more  considerable  masses  of  matter!  w^ld  not  produce  I 
oTh^  iLThrslTsUTe/'""^^  ^^^^  ^  '-^-  ^^-  ^-^^d'  ^"^  -t  a  g're'ltlr^lntn^tj 

fir^f^'  w^i^h^W^V  I'lf  t^'^'fu  P"'"''P^^'  f  '^^  production  and  distribution  of  heat, 
fires  fed  with  hot  air  should,  with  the  same  fuel,  rise  to  a  higher  pitch  of  temperature 

ie^g  Iftfuefra  "Z7^  ''''  ^\  7''^  consequence  is  independent  of  th^mate^ 
or-frcT^^^^  Si  TZZ^^  ^^  ;-  0^?  tr^:lu^e  prXS  b^ 

This  principle  may  be  rendered  still  more  evident  by  a  numerical  illustration      T^t 
us  take,  for  example,  a  blast  furnace,  into  which  600  Uic  feet  of  a     ar^  b^^^^ 
minute ;  suppose  it  to  contain  no  ore,  but  merely  coal  or  coke,  and  that  t  has  been  Sum 
ing  long  enough  to  have  arrived  at  the  equilibrium  of  temperature,  and  let  us  see  Xt 
excess  of  temperature  it  would  have  if  blown  with  air  of  300°  C.  (572°  F  )   instead  of  ^ 
ing  blown  with  air  at  0°  C.  ^  ^'  msieaaoi  De- 

..^^^.^''^'''^f^^'^^^i^^^.d^rthe  mean  temperature  and  pressure,  weigh  a  little  more 
than  4.0  pounds  avoirdupois  ;  they  contain  10-4  pounds  of  oxygen,  which  ^uld  burn^e^ 
nearly  4  pounds  of  carbon,  and  disengage  16,000  times  as  mLh  heat  asTould  raise  bT 
one  degree  Cent,  he  temperature  of  two  pounds  of  water.  These  16,000  portions  of  heat 
produced  every  minute,  will  replace  16,000  other  portions  of  heat,  diWipa^by  he  sfdes 
of  the  f^.,rnace,  and  employed  in  heating  the  gases  which  escape  from  its  mouth  TWs 
must  take  place  in  order  to  establish  the  assumed  equilibrium  of  calork. 

n  the  45  pounds  of  air  be  heated  beforehand  up  to  300°  C,  they  will  contain  about 
^'thlw  '^''."Z  '^'  ^'^'  "^  '^'  '^'^^^  disengaged  by  the  combuJti^,  and  there  wS 
i^nn  ;^J^  ^^^  .same  space  one  eighth  of  heat  more,  which  will  be  ready  to  operate 
of  3n(?>"r  ''• ''  ""f '"^  '''  range,  and  to  heat  them  one  eighth  more.  This  the^blast 
Jh/nrT;n  ^'!^'  ^  tcmpcrature  which  is  nine  eighths  of  the  blast  at  zero  C,  or  at  even 
from  19^no^^^T?^P??;'^  temperature;  and  as  we  may  reckon  at  from  2200°  lo  2700«>  F. 
Orom  1200°  to  1500°  C),  the  temperature  of  blast  furnaces  worked  in  the  common  waV 
tr360°T'  '  '^'  blast  produces  an  increase  of  temperature  equal  to  from  I'o^ 

r^r^ZJV'^Zu  ^P.P^^*^'^^^**'^  i™™ense  effects  which  this  excess  of  temperature  may 
produce  m  melallurgic  operations,  we  must  consider  that  ofYen  only  a  few  degrees  more 
temperature  are  required  to  modify  the  state  of  a  fusible  body,  or  to  determine  theX 
of  affinities  dormant  at  lower  degrees  of  heat.  Water  is  solid  at  1«  under  3^  F  h 
i£  liquid  at  1°  above.    Every  fusible  body  has  a  determinate  melting  point,  a  veryVei 


1076 


mojs. 


degrees  aboYe  which  it  is  quite  fluid,  though  it  may  be  pasty  below  it.  The  same  ott 
servation  applies  to  ordinary  chemical  affinities;  charcoal,  for  example,  which  reduces 
the  greater  part  of  metallic  oxydes,  begins  to  do  so  only  at  a  determinate  pitch  of  tem- 
perature, under  which  it  is  inoperative,  but  a  few  degrees  above,  it  is  in  general  lively 
and  complete.  It  is  unnecessary,  in  this  article,  to  enter  into  any  more  details  to  show 
the  influence  of  a  few  degrees  of  heat,  more  or  less,  in  a  furnace,  upon  chemical  opera- 
tions, or  merely  upon  physical  changes  of  state. 

These  consequences  might  have  been  deduced  long  ugo,  and  industry  might  thus  have 
been  enriched  with  a  new  application  of  science ;  but  philosophers  have  been  and  still 


are  too  much  estranged  from  the  study  of  the  useful  arts,  and  content  themselves  too 
much  with  the  minutiae  of  the  laboratory  or  theoretic  abstractions.  Within  the  space  of 
7  years  the  use  of  the  hot  blast  has  been  so  much  extended  in  Great  Britain,  as  to  have 
enabled'many  proprietors  of  iron  works  to  add  60  per  cent,  to  their  weekly  production  of 
metal,  to  diminish  the  expenses  of  smelting  by  50  per  cent.,  and,  in  many  cases,  to  produce 
a  better  sort  of  cast  iron  from  indifferea*  materials. 

797  ^^^ 


The  fieures  here  given  represent  the  blast  furnace,  and  all  the  details  of  the  air  heatiny , 


at  one  view.  Fig.  794  is  a  vertical  section  of 
the  furnace  and  the  apparatus ;  fig.  796  repre- 
sents the  plan  at  the  height  of  the  line  1,  2,  of 
fig.  794.  The  blowing  machine,  which  is  not 
shown  in  this  view,  injects  the  air  through  the 
pipe  A,  into  the  regulator  chamber  r,  fig.  796  ; 
the  air  thence  issues  by  the  pipe  b,  proceeds  to 
c,  where  it  is  subdivided  into  two  portions ;  the 
one  passes  along  the  pipe  c  d  to  get  to  the 
tuyere  t,  the  other  passes  behind  the  furnace, 
and  arrives  at  the  tuyere  t'  by  the  pipe  c  e  f. 

These  pipes  are  distributed  in  a  long  furnace 
or  flue,  whose  bottom,  sides,  and  top  are  formed 
with  fire-brick,  where  they  are  exposed  to  the 
action  of  the  flame  of  the  three  fires  x,  v,  z. 
The  flame  of  the  fire  x  plays  round  the  pipe  b  at 
its  entrance  into  the  flue,  and  quits  it  only  to  go 
into  the  chimney  h  ;  that  of  the  fire  y  acts  from 
the  point  d  to  the  same  chimney,  passing  by  the 
elbow  c ;  that  of  the  fire  z  acts  equally  upon  f 
and  H,  in  passing  by  the  elbow  e. 

Disposition  of  the  fires  and  furnace. — Fig, 


IRON. 


1077 


797  represents,  upon   a   scale   three  times  larger   than  fig.   796,  the   section  of  the 


fire  I,  of  which  the  plan  is  seen  in^g.  796,  and  the  elevation  in  fig.  794 ;  as  also  in  the 
outside  view  of  the  blast  furnace,  fig.  800.  «  j'-*  j  «»  aisso  in  ine 

♦».  '^i;^./'"'*^^  ^^  *^^5  ^^^  ^"^^  js  introduced  by  the  door  p,  fig.  794 ;  the  flame  rises  abova 
en^ih  1  rah^it'n  ?T''^1  "J""^  ll^^  "'^"^'^^  «"«  towards  the  chimney  h  through  J 
Ih^io  nio?  r  ? •  '  "'''^;- 'J^  ^^^  S'*^^' ^^<^  ^"^•""'^e  «  on  each  side  supported  b? 
obh.ng  plates  of  cast-iron  which  are  bound  together  by  4  upright  ribbed  orTa thered 
bars,  also  on  each  side;  these  bars,  n,  being  bou'nd  together  by  iron  rods  furnished  wUh 
^c:t:^:^V^i^^'"  ^^^^  ^^^^  ^^^)-    Beyond  this  d^istance,the'ou"t:iS:1,f^;S^ 

V^^  ^J^^yf""^  ^  have  exactly  a  like  disposition  with  the  above, 
i^tg.  797  indicates  the  dimensions  and  the  curvature  of  the  arch  above  the  erate  near 
Iron'casfnV.-^^*  ^''  ''^''''''''  ^'^  section  of  the  furnace  and  of  the  pipe  bSLe^t- 

Jxll^  ^^^^  ^^  ''".k"*u^  ''  °"!y  ^^''"^  3  ^^^^  ^»^«  «^  the  bottom,  and  that  the  elevation 
ill   I-        *^k'^^^'  ^^"^"  l'  "°  "'^''^  t^**^  30  inches.     Perhaps  it  might  be  made  a 
ittle  wider  xv.th  advantage ;  the  combustion  would  be  more  vigorous  aTd  effective    and 
If  the  sides  also  were  a  little  thicker,  the  heat  would  be  better  Confined.  ' 

Ihe  distance  from  the  fire-place  x  to  the  chimney  h,  is  43|  feet. 

—       T  to  the  point  c,  is        J3    

—  —        z  to  the  chimney,  is     29    —    including    the 

thifktftl:?  o/JA.^t;,.,.-At  B  the  pipe  is  18  inches  diameter  ouTsidl,  anVonT  fnch 
thick  of  metal,  and  it  tapers  to  c ;  from  c  to  d  and  from  d  to  c  the  pines  are  onh  1 1  inih^ 
in  external  diameter,  and  three  fourths  of  an  inch  thick-  thev  Le  5  fee? ?n„a  „„ T 

rlr'V"''"'^  ^'T^^'  ^'^  «^^--y  ones,inrthoseycomp^^:^^^^^^^^^^ 

play  for  the  expansion  and  contraction.     One  of  the^e  is  seen  between  n«nH/  1  ^L 

IhTAJ-'".'  ""'T  '^^"^^'^  ^  '^"^  ^>  ^-^  -  fourth  between  E  and  p       These  pipes  a^d 

tion  and  contraction  of  the  pipes  with  changes  of  temperature. 

^il.V''^''  f '"  ^•'t*"*^^^  <^^8t«»"s  «r  Oiction-roUers  of  cast-iron  are  placed  tocarrv  the  nine, 

a'refhown  Tl  til  tJV'unr  ^^''  T^^  ^'^  «T  ^^  '^«  «"-  T^se  ^a'sl^ 
r^oiroVo  •  I  V^o  *  '  h  ^'  ^^'  ^^^5  ®"®  ^^  them  IS  shown  separate  uoon  a  larger 
scale  at  g,  m  fig.  798,  as  also  the  plate  or  rail  s,  on  which  it  runs.  ^  ^" 

allnxi  .h^^v^f^  ^  T  l^^""^^^^  ^"^^^  ^^^  P'P«  ^^'""^  them ;  this  is  truly  bored  so  as  to 
n  ifnn  •  /h  ''k  ^"1 ''r  ^^^  *"y^''^  t°'"*^«  tightly  backwards  and  forwards  i^'it  like  a 
piston  in  the  barrel  of  a  pump;  a  diaphragm  moreover  prevents  the  tuv^re  Lm  K^t^J 
drawn  or  forced  entirely  out  of  its  tube.    At  the  side  of  te  tube   here  ifa  iaTorS 

^'oLr^n-LX^^^^^^^  ^^^"^^  -^-  ^'^  6I2thdet:  o^Atert'.^  ^TL^e 

l»  ^AV  ^\  ^'i^rP^aces  of  the  air-heating  furnaces  the  pipes  are  at  a  cherrv-red  heat  •  nnil 
lest  they  should  be  burned,  they  are  there  coated  with  a  lute  of  firlclay^as  shown  'n.^^ 
K,  ;n  fig.  797.     By  this  means  the  air  is  kept  up  at  the  heat  of  350°  C    nr  fi^  I 
little  above  the  boiling  point  of  quicksilver.  ^''  ""^  ^^^  ^"^  * 

f„r^«^r'''^  °-^  "A"'"^  preMur..-The  blowing-machine  belonging   to  the  above  blast 
furnace  is  moved  by  a  water  wheel  of  22  horse  power;  the  nistons  are  4  fp!t  InT      f 
have  a  31-feel  stroke,  work  double,  and  expel  1200  cubic  feet  of  air  in  t^.  1^'^ 

;»o  ;r«„  ■  u*  u^  °^  cast-iron  daily,  with  an  expenditure  of  255  of  coke  for  1  of 
cast-iron  ;  m  which  case  the  coke  amounted  to  9  tons  daily 

The  returns  by  the  hot  blast  compared  with  those  by  the  cold  are  therefore  «.»  th« 
numbers  3  and  2,  which  shows  an  advantage  by  the  former  plan  of  50  ner  cen^      tk 
consumption  of  fuel  in  the  two  case^  Jq  «c  «  #«  o  '"  •  pian  oi  XM  per  cent.      The 

1 1  ««H  L«»      i-.  1     .  ,  ^^  '^  ^^  °  to  9,  being  a  saving  in  this  article  of  about 

»Z^nU  ?5V'.f 'i*'"  ^^'^""^  '^^  «"^P»^"r  in  the  coal.   ^  ***""^ 

for^hiVe  Thfh  ?■  -^"'"^  "-^  '^'  •^^^'"""^^  mo«/A.-This  system  is  mounted  in  Staf- 
na.^  «n^  ;J  ^^^'"i^  apparatus  is  there  set  immediately  upon  the  mouth  of  he  fur- 
nace ;  and  is  composed  of  two  large  cast-iron  cylinders  of  (he'same  length,  the  one  witWn 


'4- 


1078 


IRON. 


moN. 


the  other,  leaving  a  space  between  them.    This  annular  interval  amounts  to  16  inches 
and  it  is  closed  at  top  and  bottom:  but  the  innermost  cylinder  is  open  at  both  ends,  and 
forms,  indeed,  the  vent  of  the  chimney  or  furnace.     Ii  carries  nine  rows  of  pipes,  three 
in  each  row,  which  cross  its  interior,  and  open  into  tne  annular  space. 

The  Eame  of  the  furnace  passes  between  the  intervals  of  the  cross  pipes,  heatmg 
them,  and  also  the  two  upright  cylinders  with  which  they  are  connected.  The  air  ot 
the  blowing  machine  arrives  by  a  vertical  pipe,  which  is  placed  at  the  back  of  the  lur- 
nace ;  it  enters  into  the  above  annular  space,  and  thence  circulates,  with  more  or  Jess 
velocity,  through  the 27  cross  tubes,  upon  which  the  flame  is  continually  playing;  lastly, 
it  is  drawn  through  to  the  bottom  of  the  annular  space ;  the  two  tubes  which  conduct  it 
to  the  two  tuyeres,  pass  down  within  the  brickwork  of  the  furnace,  and  thus  prevent  the 

dissipation  of  its  heat.  •        .v    r 

Below  this  heating  apparatus  there  is  a  door  for  putting  the  charges  into  the  furnace. 
The  above  arrangement  does  not  seem  to  be  the  best  for  obtaining  the  greatest  possi- 
ble heat  for  the  blast,  nor  for  favoring  the  free  action  of  the  furnace ;  but  it  illustrates 
perfectly  well  the  principle  of  this  application.     A  serpentine  movement  m  a  long  bent 
hot  channel  would  be  much  better  adapted  for  communicating  heat  to  so  bad  a  conductoi 

as  air  is  known  to  be.  ^    ,       ,  ^        i  i      •    -n^.. 

In  the  month  of  July,  1836,  I  paid  a  visit  to  Codner  Park  and  Butterly  works,  in  Der- 
byshire, belonging  to  the  eminent  iron-masters,  Messrs.  Jessop  &  Co.,  where  l  wat 
kindly  permitted  not  only  to  study  the  various  processes  of  the  manufacture  of  cast  and 
wrought  iron,  but  to  inspect  the  registers  of  the  products  of  cast  iron  in  their  blast 
furnaces  for  several  years  back.  It  appeared  that  in  the  year  1829,  only  29  tons  o 
cast-iron  were  made  weekly  in  each  of  the  blast  furnaces  at  Codner  Park.  iney 
were  then  worked  with  coke,  and  blown  with  cold  air.  Each  ton  of  iron  requirea 
for  its  production,  at  that  time,  6-82  tons  of  coals,  made  into  coke  for  snieltmg ;  with 
2-64  of  roasted  iron  ore  (carbonate),  caUed  mine ;  and  0-87  of  limestone,  the  castine  of 

^In  1835  knd  1836,  the  same  furnaces  turned  out  weekly  49  tons  of  cast-iron  each;  ant 
every  ton  of  iron  required  for  its  production  only  3  tons  of  coal  (not  made  into  coke)} 
2*72  tons  of  mine ;  and  0*77  of  lime.  r       i    •    o-:^ 

In  1829,  and  for  many  years  before,  as  well  as  one  or  two  after,  each  ton  of  coals  is  sa  d 
to  have  cost  for  coking'the  sum  of  6,.,  whence  the  6-82  tons  ^^ ^^^^^^^.J^'.^VtnZv  nr^me 
coke  for  smelting  one  ton  of  iron,  cost  fully  40..  in  coking  alone,  m  addition  to  their  prime 
cost.  The  saving  in  this  respect,  therefore,  is  40..  upon  each  ton  of  iron,  besides  the 
saving  of  fully  half  the  coal,  and  the  increased  produce  of  nearly  60  per  cent,  of  metal 
per  week.  The  iron-master  pays  the  patentee  Is.  upon  every  ton  f^  »^«"^/*!;^*»  *1^ 
makes,  and,  at  the  prices  of  1836,  he  lessened  his  expenses  by  at  least  30*.  or  40*.  per 
ton  by  the  patent  improvement.  ,  ,        -   , 

The  following  tabular  view  of  the  progression  m  the  management  and  results  of  the 
hot  blast,  is  given  by  M.  Dufrenoy,  after  visiting  the  various  iron  works  m  this  country 
where  it  had  been  introduced. 

«  At  the  Clyde  iron  works,  near  Glasgow ;  in  1829,  when  the  combusUon  was  effected 
by  Che  cold  air  blast, —  Coal. 

'  Tons.  cwt.  lbs 

There  were  consumed,  for  smelting,  3  tons  of  coke,  equivalent  to        "    ?    ^?    2 
—        for  the  blowing  engine    -  -  -  -    i      u    / 


1079 


4 
0 


Total  coal  per  ton  of  iron        -    7 
Limestone         -  "        .    "    ® 
In  1831,  with  the  hot  blast  at  450°  F.,  coke  being  still  used  in  smelting,— 
There  were  consumed,  for  smelting,  1  ton,  18  cwt.  of  coke,  equiva- 
lent to            •           -           -           '    .    ^'   .       '  \ 
for  heating  the  air,  5  cwt.  i 

for  the  blowing  engine,  7  cwt.  4  lbs.  > 

Total  coal  per  ton  of  iron 
Limestone        -  -  - 

In  July,  1833,  with  the  hot  blast  at  612?  F.,  raw  coal  alone  being  used 

for  smelting, — 
There  were  consumed :  for  smelting       ----- 

for  heating  the  air         - 

—  for  the  blowing  engine  -  -  -  - 


13    7 
Wl  0 


6    0 
12    4 


4 
0 


2 
0 
0 


18 
9 


0 

8 

11 


4 

0 


0 
0 
2 


Total  coal  per  ton  of  iron 
Limestone 


-    2    19    2 
-070 


«  At  the  last  period  the  use  of  hot  air  had  increased  the  make  of  the  furnaces  by  more 
than  one  third,  and  had  consequently  produced  a  great  saving  of  expense  in  the  article 
of  labor.  The  quantity  of  blast  necessary  for  the  furnaces  was  also  sensibly  diminished ; 
for  a  blowing  engine  of  seventy-horse  power,  which,  in  1829,  served  only  for  three  blast 
furnaces,  was  now  sufficient  for  the  supply  of  four. 

"  On  comparing  these  several  results,  we  find  that  the  economy  of  fuel  is  in  proportion 
to  the  temperature  to  which  the  air  is  raised.  As  for  the  actual  saving,  it  varies  in 
every  work,  according  to  the  nature  of  the  coal,  and  the  care  with  which  the  operation 
is  conducted. 

"This  process,  though  it  has  been  four  years  in  use  in  the  works  near  Glasgow 
(which  it  has  rescued  from  certain  ruin),  has  scarcely  passed  the  borders  of  Scotland ; 
the  marvellous  advantages,  however,  which  it  has  produced,  are  beginning  to  triumph 
over  prejudice,  and  gradually  to  extend  its  use  into  the  different  English  iron  districts. 
There  are  one-and-twenty  works,  containing  altogether  sixty-seven  blast  furnaces,  in 
which  hot  air  is  used.  The  pig  iron  run  out  of  these  furnaces  is  generally  No.  1,  and  is 
fit  for  making  the  most  delicate  castings.  This  process  is  equally  applicable  to  forge 
pigs  for  the  manufacture  of  bar  iron ;  since  in  order  to  obtain  this  quality  of  iron,  it  is 
only  necessary  to  alter  the  proportion  of  fuel  and  mineral.  In  the  forges  of  the  Tyne  iron- 
works, near  Newcastle,  and  of  Codner  Park,  near  Derby,  pigs  made  in  furnaces  blown  by 
hot  air,  are  alone  used  in  the  manufacture  of  bar  iron. 

"  In  the  side  of  the  tuyere  pipe  a  small  hole  is  made,  by  means  of  which  the  heat  of 
the  air  may  be  ascertained  at  any  moment.  This  precaution  is  indispensable,  it  being  of 
unportance  to  the  beneficial  use  of  hot  air,  that  it  be  kept  at  a  uniformly  high  temperature. 
With  a  proper  apparatus  the  air  is  raised  to  612  degrees  Fahr.,  which  is  a  greater  heat, 
by  several  degrees,  than  is  necessary  for  the  fusion  of  lead." 

«  At  Calder  works  the  consumption  of  fuel  has  diminished  in  the  proportion  of  7  tons 
17  cwts.  to  2  tons  2  cwts.  There  has  also  been  a  great  diminution  of  expense  in  limestone, 
of  which  only  5§  cwts.  are  now  used,  instead  of  13  cwts.,  which  were  used  in  1828.  This 
decrease  results,  as  I  have  already  said,  from  the  high  temperature  which  the  furnace  has 
acquired  since  the  introduction  of  hot  air. 

"The  quantity  of  blast  has  been  reduced  from  3500  cubic  feet  per  minae,  to  2627 
cubic  feet ;  the  pressure  also  has  been  reduced  from  3^  to  2|  lbs." 

0/  the  refinery  of  cast-iron,  or  its  conversion  into  bar-iron,  in  England.— This  operation 
IS  naturally  divisible  into  three  distinct  parts.  The  first,  or  the  finery  properly  soeakine, 
IS  executed  in  pecuhar  furnaces  called  running  out  fires  ;  the  second  operation  completes 
the  first,  and  is  called  puddling;  and  the  third  consists  in  welding  several  iron  lars  to- 
gether, and  working  them  under  forge  hammers,  and  between  rolls. 

1.  The  finery  furnaces  are  composed  of  a  body  of  brickwork,  about  9  feet  square  •  rising 
but  little  above  the  surface  of  the  ground.  The  hearth,  placed  in  the  middle, 'is  two 
feet  and  a  half  deep;  it  is  rectangular,  being  in  general,  3  feet  by  2,  with  its  greatest 
side  parallel  to  the  face  of  the  tuyeres ;  and  it  is  made  of  cast  iron  in  four  plates.  On  the 
side  of  the  tuyeres  there  is  a  single  brick  wall.  On  the  three  other  sides,  sheet  iron  doors 
are  placed,  to  prevent  the  external  air  from  cooling  the  metal,  which  is  almost  always 
worked  under  an  open  shed,  or  in  the  open  air,  but  never  in  a  space  surrounded  by  walls 
The  chimney,  from  15  to  18  feet  high,  is  supported  upon  four  columns  of  cast  iron-  its 
Imtcl  is  four  feet  above  the  level  of  the  hearth,  in  order  that  the  laborers  mav  work  with- 
out restraint. 

The  number  of  tuyeres  is  from  two  to  three;  they  are  placed  at  the  height  of  the  lie 
of  the  crucible  or  hearth,  and  distributed  so  as  to  divide  its  length  into  equal  parts  • 
their  axes  being  inclined  towards  the  bottom,  at  an  angle  of  from  25°  to  30°,  so  as  to  point 
upon  the  bath  of  melted  metal  as  it  flows.  The  cast-iron  nose-pipe  is  incased,  and  water 
IS  made  to  cuculate  in  the  hollow  space  by  means  of  cyUndrical  tubes ;  being  introduced 
by  one  tube,  and  let  oflf  by  another,  so  as  to  prevent  the  tuyeres  from  getting  burned  in 
the  ])rocess. 

Two  nozzles  are  usually  placed  in  each  tuyere,  to  render  the  blast  constant  and  uni- 

f  jrm ;  and  for  the  same  end,  the  air  impelled  by  the  beUows,  is  sometimes  received  at 

r  .nJ!>^^^^*°/*    '^^  quantity  of  air  blown  into  the  fineries  is  considerable ;  being 

nearly  400  cubic  feet  per  minute  for  each  finery ;  or  about  the  eighth  part  of  the  consumiv 

tion  of  a  blast  furnace.  ^ 

The  finery  furnace,  or  running  out  fire,  is  represented  in  figs.  801  and  802.  It  is  a 
smelting  hearth,  in  which  by  first  fusing  and  then  cooling  gray  cast  iron  in  a  pecuUar 
way,  It  IS  converted  into  white  cast  iron,  caUed  fine  iron,  or  fine  metal,  of  the  quality  of 
forge  pig,  for  makmg  malleable  iron  by  the  puddUng  process.  The  furnace  resembles  the 
forge  hearth  employed  m  Germany  and  France  for  converting  forge  pig  into  wiou<Tht 
iron  ;  but  it  differs,  particularly  in  this,  that  the  fused  iron  is  run  out  into  an  oblon«r  iron 
trough,  for  sudden  congelation.  ° 

a  is  the  air-chest,  in  communication  with  the  blowing  cylinder,  or  bellows;  the  aii 


1080 


oemg 


IRON. 


conducted  through  at  least  two  blast  pipes  to  the  fire,  fj^^^f  ^e^unes  fhrou^ 
pipe 

n 


even  4  or  6  pipes,    b  is  the  side  of  the  furnace,  corresponding  to  the  tuyere  platev  in 

802 


-which  are  the  openings  for  the  blast  pipes.  All  the  sides  of  the  furnace  are  hollow,  and 
are  kept  cool  by  the  circulation  of  water  through  the  cavity  between  them,  c  is  the  front 
wall  of  the  furnace,  having  a  strong  cast  iron  plate  containing  the  tap  holes  for  running 
off  the  melted  metal,  d  d  is  the  exterior  waU  of  the  furnace,  which  corresponds  to  the 
cantre-vent  and  ash-hearth  of  the  French  refining  forge.  «,  is  the  top  plate  upon  which  the 
coke  is  piled  up  in  store.  //,//",  iron  props  of  the  chimney,  (not  shown  in  this  view).  |, 
cast  iron  trough  into  which  the  fine  iron  is  run  off  in  fusion  ;  which  is  sometimes  made 
in  one  piece,  but  more  usually  in  separate  plates  joined  together.  Beneath  this  mould 
a  stream  of  water  is  made  to  flow,    h  is  the  bottom  of  the  hearth,  covered  with  sand. 

In  the  finery  process,  the  hearth  or  crucible  of  the  furnace  is  filled  with  coke ;  then  six 
pi^s  of  cast  iron  are  laid  horizontally  on  the  hearth,  namely,  four  of  them  parallel  to 
the  four  sides,  and  two  in  the  middle  above ;  and  the  whole  is  covered  up  m  a  dome- 
form,  with  a  heap  of  coke.  The  fire  is  now  lighted,  and  in  a  quarter  of  an  hour  the 
blast  is  appUed.  The  cast  iron  flows  down  graduaUy,  and  collects  in  the  crucible ;  mor«» 
coke  bein<'  added  as  the  first  quantity  burns  away.  This  operation  proceeds  by  itself; 
the  melted  metal  is  not  stirred  about,  as  in  some  modes  of  refinery,  and  the  temperature 
is  always  kept  high  enough  to  preserve  the  metal  liquid.  During  this  stage  the  coals 
are  observed  continually  heaving  up,  a  movement  due  in  part  to  the  action  of  the  blast, 
and  in  part  to  an  expansion  caused  in  the  metal  by  the  discharge  of  gaseous  oxyde  ot 
carbon  When  all  the  pig  iron  is  collected  at  the  bottom  of  the  hearth,  which  happens 
commonly  at  the  end  of  two  hours,  or  two  and  a  half,  the  tap  hole  is  opened,  and  the 
fine  metal  flows  out  with  the  slag,  into  the  loam-coated  pit,  on  a  plate  10  feet  long, 
3  broad,  and  from  2  inches  to  2^  thick.  A  portion  of  the  slag  forms  a  smaU  crust  on  the 
surface  of  the  metal ;  but  most  part  of  it  coUects  in  a  basin  scooped  out  at  the  bottom  of 
the  pit,  into  which  the  fine  metal  is  run.  .  ^    ^      .        r       j    •       •. 

A  lart'e  quantity  of  water  is  thrown  on  the  fine  metal,  with  the  view  of  rendering  it 
brittle,  and  perhaps  of  partially  oxydizing  it.  This  metal  suddenly  cooled,  is  very  white, 
and  possesses  in  general  a  fibrous  radiated  texture  ;  or  sometimes  a  cellular,  including  a 
considerable  number  of  small  spherical  cavities,  like  a  decomposed  amygdaloid  rock.  If 
the  cast  iron  be  of  bad  quality,  a  little  limestone  is  occasionally  used  in  the  above 
operation. 

Three  samples  of  cinder,  analyzed  by  Berthier,  gave.  .,  „  «^«  ,^   ,, 

SiUca  0-276;  protox.  of  iron,  0-612;  alumina,  0-040 ;  phosp.  acid,  0-072,  Dudley. 

0-368  —  0-610        —        0-015;  puddling  of  Dowlais. 

_  0-424  —  0-520        —        0-033;  ditto. 

The  remarkable  fact  of  the  presence  of  phosphoric  acid,  shows  how  important  this  oper- 
ation is  to  the  purification  of  the  iron.  The  charge  varies  from  a  ton  and  a  quarter  to  a 
ton  and  a  half  of  pigs;  and  the  loss  by  the  process  varies  from  12  to  17  per  cent. 

The  fine  metal  is  broken  into  fragments,  and  sent  to  the  pudtUing  furnace  after  the 
product  of  each  operation  has  been  weighed.  The  coal  consumed  in  the  fine  metal 
process  is  from  4  to  5  hundred  weight  for  the  ton  of  cast  iron.  About  10  tons  may  be 
refined  per  dienij  a  quantity  somewhat  greater  than  the  supply  from  a  blast  furnace  ;  but 
the  fineries  are  not  worked  on  the  Sundays ;  and  therefore  a  smelting  furnace  just  keeps 
one  of  them  in  play.  Whatever  care  be  taken  in  this  process,  the  bar  iron  finally 
reoultin*'  is  never  so  good  as  if  wood  charcoal  had  been  used  in  the  refinery ;  and  hence 
in  makfng  sheet  iron  for  the  tin  plate  manufacture,  wood  charcoal  is  substituted  for 
coke  in  one  Welsh  establishment.    The  cast  iron  treated  with  charcoal,  gets  into  cloU 


IRON. 


1081 


Dr  lumps  in  the  finery  furnace,  which  are  lifted  out,  set  under  the  hammer,  and  ilalts.ied 
into  thin  cakes. 

The  main  effect  of  the  finery  process,  is  probably  the  separation  of  the  plumbagi- 
nous part  of  the  charcoal,  which  is  disseminated  through  the  gray  cast  iron  in  a  state 
of  imperfect  chemical  combination.  When  that  is  removed  the  metal  becomes  mere 
homogeneous,  having  no  crystalline  carbon  present  to  counteract  its  transition  into  pure 
iron ;  much  of  the  silica  and  manganese  are  also  vitrified  together,  and  run  off  in  the  finery 
cinder. 

2.  The  puddling  furnace  is  of  the  reverberatory  form.  It  is  bound  generally  with  iron, 
as  represented  in  the  side  view,  fi^,  803)  by  means  of  horizontal  and  vertical  bars,  which 

808 


are  joined  together  and  fixed  by  wedges,  to  prevent  them  from  starting  asunder.  Very 
frequently,  indeed,  the  reverberatory  furnaces  are  armed  with  cast-iron  plates  over  their 
whole  surface.  These  are  retained  by  upright  bars  of  cast  iron  applied  to  the  side  walls, 
and  by  horizontal  bars  of  iron,  placed  across  the  arch  or  roof.  The  furnace  itself  is 
divided  interiorly  into  three  parts ;  the  fire-place^  the  hearth^  and  thejlue.  The  fire-place 
varies  from  3|  to  4^  feet  long,  by  from  2  feet  8  inches  to  3  feet  4  inches  wide.  The  door 
way  by  which  the  coke  is  charged,  is  8  inches  square,  and  is  bevelled  off  towards  the  out- 
side of  the  furnace.  This  opening  consists  entirely  of  cast  iron,  and  has  a  quantity  of 
coal  gathered  round  it.  The  bars  of  the  fire  grate  are  moveable,  to  admit  of  more  readily 
clearing  them  from  ashes. 

Fig.  804  is  a  longitudinal  section  referring  to  the  elevation ;  fig.  803,  and  fig.  805, 


805 


tf[t_A_g 


zZ^^^^^S? 


Is  a  ground  plan.  When  the  furnace  is  a  single  one,  a  square 
the  fire-place  opposite  to  the  door,  through  which  the  rakes  are 
heated. 

a  is  the  fire  door ;  6,  the  grate ;  c,  the  fire  bridge ;  d  d,  cast- 
upon  cast-iron  beams  e  e,  which  are  bolted  upon  both  sides 
plates  of  the  furnace.  /  is  the  hearth  covered  with  cinders 
working  door,  which  may  be  opened  and  shut  by  means  of 
move  it  up  and  down.  In  this  large  door  there  is  a  hole 
which  the  iron  may  be  worked  with  the  paddles  or  rakes; 


hole  is  left  in  the  side  of 
introduced,  in  order  to  be 

•iron  hearth  plates,  resting 

to  the  cast-iron  binding 

or  sand ;  g,  is  the  main 

a  lever  g',  and  chain  to 

5  inches  square,  through 

it  may  also  be  closed  air 


I 


1082 


IRON. 


tight.     There  is  a  second  working  door  h,  near  the  flue,  for  introaucing  the  cast  irou 
so  Ihat  it  may  soften  slowly,  till  it  be  ready  for  drawing  towards  the  bridge,    t,  is  the 
chimney,  from  30  to  50  feet  high,  which  receives  commonly  the  flues  of  two  furnaces,  each 
806  provided  with  a  damper  plate  or  register.     Fig.  80(5, 

shows  the  main  damper  for  the  top  of  the  common 
chimney,  which  may  be  opened  or  shut  to  anv  degree  by 
means  of  the  lever  and  chain,     fc.  Jig.  804,  is  the  tap  or 
floss  hole  for  running  off  the  slag  or  cinder. 
iP"     '  r        K^^^"*^  "  '^^^  ^^^^  ^^  sometimes  made  of  bricks,  sometimes  of 

'r: '    '         T      ■■■  cast  iron.     In  the  first  case  it  is  composed  of  fire-bricks 

set  on  edge,  forming  a  species  of  flat  vault.  It  rests 
immediately  on  a  body  of  brickwork  either  solid  or 
arched  below.  When  it  is  made  of  cast  iron,  which  is 
now  beginning  to  be  the  general  practice,  it  may  be 
made  either  of  one  piece  or  of  several.  It  is  commonly 
in  a  single  piece,  which,  however,  causes  the  inconvenience  of  reconstructing  the  furnace 
entirely  when  the  sole  is  to  be  changed.  In  this  case  it  is  a  little  hollow,  as  is  shown  in  the 
preceding  vertical  section  ;  but  if  it  consists  of  several  pieces,  it  is  usually  made  flat. 

The  hearths  of  cast  iron  rest  upon  cast  iron  pillars,  to  the  number  of  four  or  five ; 
which  are  supported  on  pedestals  of  cast  iron  placed  on  large  blocks  of  stone.  Such  an 
arrangement  is  shown  ih  the  figure,  where  also  the  square  hole  a,  Jig.  803,  for  heating  the 
rake  irons,  may  be  observed.  The  length  of  the  hearth  is  usually  six  feet ;  and  its  breadth 
varies  from  one  part  to  another.  Its  greatest  breadth,  which  is  opposite  the  door,  is  four 
feet.  In  the  furnace,  whose  horizontal  plan  is  given  above,  and  which  produces  good  re- 
sults, the  sole  exhibits,  in  this  part,  a  species  of  ear,  which  enters  into  the  mouth  of  the  door. 
At  its  origin  towards  the  fireplace,  it  is  2  feet  10  inches  wide ;  from  the  fire  it  is 
separated,  moreover,  by  a  low  wall  of  bricks  (the  fire-bridge)  10  inches  thick,  and  from 
3  inches  to  5  high.  At  the  other  extremity  its  breadth  is  2  feet.  The  curvature 
presented  by  the  sides  of  the  sole  or  hearth  is  not  symmetrical ;  for  sometimes  it  makes 
an  advancement,  as  is  observable  in  the  plan.  At  the  extremity  of  the  sole  furthest  from 
the  fire,  there  is  a  low  rising  in  the  bricks  of  21  inches,  called  the  altar,  for  preventing 
the  metal  from  running  out  at  the  Jloss-hole  when  it  begins  to  fuse.  Beyond  this  shelf 
The  sole  terminates  in  an  inclined  plane,  which  leads  to  the  Jloss,  or  outlet  of  the  slag 
from  the  furnace.  This  JJoss  is  a  little  below  the  level  of  the  sole,  and  is  hollowed  out  of 
the  basement  of  the  chimney.  The  slag  is  prevented  from  concreting  here,  by  the  flame 
being  made  to  pass  over  it,  in  its  way  to  the  sunk  entry  of  the  chimney  ;  and  there  is  also 
a  plate  of  cast  iron  near  this  opening,  on  which  a  moderate  fire  is  kept  up  to  preserve  the 
fluidity  of  the  scoriae,  and  to  burn  the  gases  that  escape  from  the  furnace,  as  also  to  quicken 
the  draught,  and  to  keep  the  remote  end  of  the  furnace  warm.  On  the  top  of  this  iron 
plate,  and  at  the  bottom  of  the  inclined  plane,  the  cinder  accumulates  in  a  small  cavity, 
whence  it  afterwards  flows  away ;  whenever  it  tends  to  congeal,  the  workman  must  clear 
it  out  with  his  rake. 

The  door  is  a  cast  iron  frame  filled  up  inside  with  fire-bricks ;  through  a  small  hole  in 
its  bottom  the  workmen  can  observe  the  state  of  the  furnace.  This  hole  is  at  other  times 
shut  with  a  stopper.     The  chimney  has  an  area  of  from  14  to  16  inches. 

The  hearth  stands  3  feet  above  the  ground.  Its  arched  roof,  only  one  brick  thick,  is 
raised  2  feet  above  the  fire-bridge,  and  above  the  level  of  the  sole,  taken  at  the  middle  of 
the  furnace.  At  its  extreme  point  near  the  chimney,  its  elevation  is  only  8  inches ;  and 
the  same  height  is  given  to  the  opening  of  the  chimney. 

In  most  iron  works  the  sole  is  covered  with  a  layer  of  refractory  sand  from  2|  to  3  inches 
thick,  which  is  lightly  beat  down  with  a  shovel.  At  each  operation  a  portion  of  the  sand 
is  carried  away ;  and  is  replaced  before  another.  Within  these  few  years,  there  has  been 
substituted  for  the  sand  a  body  of  pounded  slags ;  a  substitution  which  has  occasioned,  it 
is  said,  a  great  economy  of  iron  and  fuel. 

The  fine  metal  obtained  by  the  coke  is  puddled  by  a  continuous  operation,  which  calls 
<br  much  care  and  skill  on  the  part  of  the  workmen.  To  charge  the  puddling  furnace, 
pieces  of  Jine  metal  are  successively  introduced  with  a  shovel,  and  laid  one  over  another  on 
the  sides  of  the  hearth,  in  the  form  of  piles  rising  to  the  roof;  the  middle  being  left  open 
for  puddling  the  metal,  as  it  is  successively  fused.  Indeed,  the  whole  are  kept  as  far  sepa- 
rate as  possible,  to  give  free  circulation  to  the  air  round  the  piles.  The  working  door  of 
the  furnace  is  now  closed,  fuel  is  laid  on  the  grate,  and  the  mouth  of  the  fireplace,  as  well 
as  the  side  opening  of  the  grate,  are  both  fiUed  up  with  coal,  at  the  same  time  that  the 
damper  is  entirely  opened. 

The  fine  mc^al  in  about  twenty  minutes  comes  to  a  white-red  heat,  and  its  thin-edged 
fragments  begin  to  melt  and  fall  in  drops  on  the  sole  of  the  furnace.  At  this  period  the 
workman  opens  the  small  hole  of  the  furnace  door,  detac  !ies  with  a  rake  the  pieces  of 
fine  metal  that  begin  to  melt,  tries  to  expose  new  surfaces  to  the  action  of  the  heat,  and 


IRON. 


1083 


lu  order  to  prevent  the  metal  from  running  together  as  it  softens,  he  removes  it  from  the 
vicinity  of  the  fire-bridge.     When  the  whole  of  the  fine  metal  has  thus  got  reduced 
to  a  pasty  condition,  he  must  lower  the  temperature  of  the  furnace,  to  prevent  it  from 
becoming  more  fluid.     He  closes  the  damper,  takes  out  a  portion  of  the  fire,  and  the 
ribs  of  the  grate,  and  also  throws  a  little  water  sometimes  on  the  semi-fused  mass.     He 
then  works  about  with  his  paddie  the  clotty  metal,  which  swells  up,  with  the  discharge 
of  gaseous  oxyde  of  carbon,  burning  with  a  blue  flame,  as  if  the  bath  were  on  fire      The 
metal  becomes  finer  by  degrees,  and  less  fusible ;   or  in  the  language  of  the  workmen,  it 
begins  to  get  dri/.     The  disengagement  of  the  oxyde  of  carbon  diminishes,  and  soon 
stops.     The  workmen  continue  meanwhile  to  puddle  the  metal  till  the  whole  char<'e  be 
reduced  to  the  state  of  incoherent  sand ;    and  at  that  time,  the  ribs  of  the  <'rate  are 
replaced,  the  fire  is  restored,  and  the  register  is  progressively  opened  up.      With  the 
return  of  the  heat,  the  particles  of  metal  begin  to  agglutinate,  the  charge  becomes  more 
difficult  to  raise,  or  in  the  laborers'  language,  it  works  heavy.     The  refining  is  now 
hnished,  and  nothing  remains  but  to  gather  the  iron  into  balls.     The  founder  with  his 
paddle  takes  now  a  little  lump  of  metal,  as  a  nucleus,  and  makes  it  roll  about  on  the 
surface  of  the  furnace,  so  as  to  collect  more  metal,  and  form  a  ball  of  about  60  or  70 
pounds  weight.     With  a  kind  of  rake,  called  in  England  a  dolly,  and  which  he  heats 
beforehand,  the  workman  sets  this  baU  on  that  side  of  the  furnace  most  exposed  to  the 
action  of  the  heat,  in  order  to  unite  its  different  particles;    which  he  then  squeezes 
together  to  force  out  the  scoriae.     When  all  the  balls  are  fashioned,  (they  take  about 
ZV  minutes  work,)  the  small  opening  of  the  working  door  is  closed  with  a  brick,  to  cause 
the  heat  to  rise,  and  to  facilitate  the  welding.     Each  ball  is  then  lifted  out,  either  with 
tongs.  If  roughing  rollers  are  to  be  used,  as  in  Wales,  or  with  an  iron  rod  welded  to  the 
ump  as  a  handle,  if  the  hammer  is  to  be  employed,  as  in  Staffordshire.     Thus  we  see 
that  he  operation  lasts  m  whole  from  2  hours  to  2i ;  in  a  quarter  of  an  hour,  the  fine 
metal  melts  at  its  edges,  when  the  puddling  begins,  in  order  to  eflfect  its  division;  at  the 
end  of  an  hour  or  an  hour  and  a  half,  the  metal  is  entirely  reduced  to  a  sand ;  a  state 
hat  is  kept  up  for  half  an  hour  by  continual  stirring;  and  finally,  the  balling  operation 
takes  nearly  the  same  time.  °    ^ 

The  charge  for  each  operation  is  from  3^  to  4  hundred  weight ;  and  sometimes  the 
cuttings  of  bar-ends  are  introduced,  which  are  puddled  apart.  The  loss  of  iron  is  here 
verr  variable  according  to  the  degree  of  skUl  in  the  workman,  who  by  negligence  may 
suffer  a  considerable  body  of  iron  to  scorify  or  to  flow  into  the  hearth  and  raise  the  bot- 
tom.  In  good  working,  the  loss  is  from  8  to  10  per  cent.  In  Wales,  the  consumption 
of  coal  IS  estimated  at  one  ton  for  every  ton  of  fine  metal.  About  five  puddling  furnaces 
are  required  for  the  service  of  one  smelting  furnace  and  one  finery.  The  hearth  of  the 
puddhng  furnace  should  be  exposed  to  heat  for  12  hours  before  the  work  begins  on  the 
Mondays;  and  on  the  Saturdays,  the  old  sole  must  be  cleared  out,  by  melting  it  off  and 
running  It  out  by  the  floss-hole.  '  «=,  "  "u,  ana 

Mr.  Schafthault  obtained,  in  May,  1835,  a  patent  for  the  conversion  of  cast  into 
wrought  iron,  by  adding  a  mixture  of  black  oxyde  of  manganese,  common  salt,  and 
mrnac^  ^"  ^^^^^^  portions,  successively,  to  the  melting  iron  in  the  puddling 

The  reheating  furnaces,  hailing  furnaces,  or  mill  furnaces,  are  analogous  to  the  puddline 
furnaces,  but  only  of  larger  dimensions.  ^  i-  » 

The  wood  charcoal  forge  hearth  is  employed  for  working  up  scrap  iron  into  boiler  plate, 
&c.  He -e  22  bushels  of  charcoal  are  consumed  in  making  one  ton  of  iron  of  that  descrin! 
tion,  from  boiler  plate  parings.  ^ 

Machines  jTor  forging  and  condensing  the  iron.— In  England  there  are  emploved  for  the 
i^£"''.*'i-  ^^"^""^  ""f  f  ^^^  ''■°"'  cast-iron  hammers  of  great  weight,  and  cvlinders  of 
i.w  J^ ,  ^i^^"^*^"^^^'^  ^eatmg  out  the  balls,  or  extending  the  iron  into  bars,  as  also 
?tTr^  1  •  "'i  ^^T  se^^ral  mechanisms  are  moved  either  by  a  steam  engine,  as  in 
Staffordshire,  and  m  almost  all  the  other  counties  of  England,  or  bv  water-wheels  when 
t^  localities  are  favorable,  as  m  many  establishments  in  South  Wkles.  We  shall  here 
otter  some  details  concerning  these  machines. 

The  main  driving  shaft  usually  carries  at  either  end  a  large  toothed  wheel,  which 
communicates  motion  to  the  different  machines  through  smaller  toothed  wheels.  Of 
these  there  are  commonly  six,  four  of  which  drive  four  different  systems  of  cylinders, 
and  the  two  others  work  the  hammer  and  the  shears.  The  different  cylinders  of  an  iron 
work  should  never  be  placed  on  the  same  arbor,  because  they  are  not  to  move  together, 
and  they  must  have  different  velocities,  according  to  their  diameter.  In  order  to  econo- 
mize time  and  facilitate  labor,  care  is  taken  to  associate  on  one  side  of  the  motive  ma- 
chine the  hammer,  the  shears,  and  the  reducing  cylinders  ;  and  on  the  other  side  to  place 
the  several  systems  of  cylinders  for  drawing  out  the  iron  into  bars.  For  the  same  reason 
the  pud.Uing  furnaces  ought  to  be  grouped  on  the  side  of  the  hammer ;  and  the  reheatins 
furnaces  on  the  other  side  of  the  works.  * 


1084 


IRON. 


The  hammers   fi^.  807,  are  made  entirely  of  cast  iron ;  they  are  nearly  10  feci  long, 
mnd  consist  usually  "of  two  parts,  the  helve  c,  and  the  head  or  pane  d.    The  latter  cntera 

807 


with  friction  into  the  former,  and  is  retained  in  its  place  by  wedges  of  iron  or  wood. 
The  head  consists  of  several  faces  or  planes  receding  from  each  other;  for  the  purpose 
of  c'ivin''  different  forms  to  the  ball  lumps.  A  ring  of  cast-iron  o,  caUed  the  cam-nng  bag, 
bearing  moveable  cams  b  b,  drives  the  hammer  d,  by  lifting  it  up  round  its  fulcrum  /,.and 
then  letting  it  fall  alternately.  In  one  iron  work,  this  ring  was  found  to  be  3  feet  m  diam- 
eter, 18  inches  thick,  and  to  weigh  4  tons.  The  weight  of  the  helve  (handle)  of  the 
corresponding  hammer  was  3  tons  and  a  half,  and  that  of  the  head  of  the  hammer,  8  hun- 
dred weight.  „    ,    ,  /...  -1    •     «k»»^»n 

The  anvil  e  consists  also  of  two  parts  ;  the  one  caUed  the  pane  of  the  anvU,  is  the  coun- 
terpart of  the  pane  of  the  hammer;  it  likewise  weighs  8  hundred  weight.  The  second,  g, 
named  the  stock  of  the  anvil,  weighs  4  tons.  Its  form  is  a  parallelopiped,  with  the  edges 
rounded.  The  bloom  or  rough  ball,  from  the  puddle  furnace,  is  laid  and  turned  about 
upon  it,  by  means  of  a  rod  of  iron  welded  to  each  of  them,  caUed  a  porter.  Swce  the 
wei-ht  of  these  pieces  is  very  great,  and  the  shocks  very  considerable,  the  utmost  pre- 
cautions should  be  taken  in  setting  the  hammer  and  its  anvil  upon  a  substantial  mass  ol 
masonry,  as  shown  in  the  figure,  over  which  is  laid  a  double,  or  even  quadruple  flooring 
of  woofl,  formed  of  beams  placed  in  transverse  layers  close  to  each  other.  Such  beams 
possess  an  elastic  force,  and  thereby  partially  destroy  the  injurous  reaction  of  the  shock. 
In  some  works,  a  six-feet  cube  of  cast  iron  is  placed  as  a  pedestal  to  the  anvil. 

Forse  hammers  are  very  frequently  mounted  as  levers  of  the  first  kind,  with  the  centre 
of  motion  about  one  third  or  one  fourth  of  the  length  of  the  helve  from  the  cam  wheel. 
The  principle  of  this  construction  will  be  understood  by  inspection  of  fig.  605.  ine  snon 
end  of  the  lever  which  is  struck  down  by  the  tappet  c,  is  driven  agamst  the  end  of  an  elastic 
beam  a,  and  immediately  rebounds,  causing  the  long  end  to  strike  a  harder  blow  upon  the 

^^The  shears  are  composed  of  two  branches,  the  ont  fixed  and  the  other  moveable,  each 
formed  of  two  pieces.  The  fixed  branch  is  a  cast-iron  plate,  which  forms  one  mass  with 
a  horizontal  base  fixed  to  a  piece  of  wood  or  cast  iron  buried  in  the  ground.  A  sharp- 
ened  chisel  is  fastened  to  its  upper  part  by  screws  and  nuts.  The  moveable  branch  is 
Ukcwise  of  cast  iron  ;  it  bears  an  axis  round  which  it  turns,  and  this  axis  passes  through 
the  fixed  part.  It  is  also  furnished  with  a  cutting  chisel,  fixed  on  by  nuts  and  screws. 
An  eccentric  or  an  ellipse,  moved  directly  by  a  toothed  wheel,  lifts  the  moveable  branch 
of  the  shears,  and  forces  it  to  cut  the  iron  bars  presented  to  it.  The  pressure  exerted  by 
these  scissors  is  such,  that  they  can  cut  without  difficulty,  iron  bars,  one  half  or  two  thirds 

of  an  inch  thick.  «.         •         r  a     *i,«» 

Cylinders  —The  compression  between  cylinders  now  effects,  m  a  lew  seconds,  inai 
condensation  and  distribution  of  the  fibres,  which,  40  years  ago,  could  not  be  accom- 
plishel  till  after  many  heats  in  the  furnace,  and  many  blows  of  the  hammer,  ine 
cylinders  mav  be  distinguished  into  two  kinds;  1.  those  which  serve  to  draw  out  tbe 
2^1,  called  puddling  rolls,  or  roughing  rolls,  and  which  are,  in  fact,  reducing  cylinders ; 
2.  the  cylinders  of  extension,  called  rollers,  for  drawing  into  bars  the  massive  iron  alter 
it  has  received  a  welding,  to  make  it  more  maUeable.    This  second  kind  of  cylinders  is 


IRON. 


1085 


•ubdivided  into  several  varieties,  according  to  the  patterns  of  bar  iron  that  are  required. 
These  may  vary  from  2  inches  square  to  less  than  one  sixth  of  an  inch. 

Beneath  the  cylinders  there  is  usually  formed  an  oblong  fosse,  into  which  the  scorise 
and  the  scales  fall  when  the  iron  is  compressed.  The  sides  of  this  fosse,  constructed  of 
stone,  are  founded  on  a  body  of  solid  masonrj',  capable  of  supporting  the  enormous  load 
of  the  cylinders.  Beams  of  wood  form  in  some  measure  the  sides  of  this  pit,  to  which 
cylinders  may  be  made  fast,  by  securing  them  with  screws  and  bolts.  Massive  bars  of 
cast  iron  are  found,  however,  to  answer  still  better,  not  only  because  the  uprights  and 
bearers  may  be  more  solidly  fixed  to  them,  but  because  the  basement  of  heavy  metal  is 
more  difficult  to  shatter  or  displace,  an  accident  which  happens  frequently  to  the 
wooden  beams.  A  rill  of  water  is  supplied  by  a  pipe  to  each  pair  of  cylinders,  to 
hinder  them  from  getting  hot;  as  also  to  prevent  the  hot  iron  from  adhering  to  the 
cylinder,  by  cooling  its  surface,  and  perhaps  producing  on  it  a  slight  degree  of 
oxydizement. 

The  shafts  are  one  foot  in  diameter  for  the  hammer  and  the  roughing  rolls ;  and  six 
inches  where  they  communicate  motion  to  the  cylinders  destined  to  draw  the  iron  into 
bars. 

The  roughing  rolls  are  employed  either  to  work  out   the  lump  or  ball  immediately 
after  it  leaves  the  puddling  furnace,  as  in  the  Welsh  forges,  or  only  to  draw  out  the 
piece,  after  it  has  been  shaped  under  the  hammer,  as  is  practised  in  most  of  the  Stafford- 
shire establishments.      These  roughing  cylinders  are  generally  7  feet  Ion?,  including 
the  trunnions,  or  5  feet  between  the  bearers,  and  18  inches  diameter;  and  weigh  in  the 
whole  from  4  to  4^  tons.      They  contain  from  5  to  7  grooves,  commonly  of  an  elliptical 
form,  one  smaller  than  another  in  regular  progression,  as  is  seen  in  fig.  597.     The  small 
axis  of  each  ellipse,  as  formed  by  the  union  of  the  upper  and  under  grooves,  is  always 
placed  in  the  vertical  direction,  and  is  equal  to  the  great  axis,  or  horizontal  axis  of  the 
succeeding  groove;  so  that  in  transferring  the  bar  from  one  groove  to  another,  it  must 
receive  a  quarter  of  a  revolution,  whereby  the  iron  gets  elongated  in  every  direction. 
Sometimes  the  roughing  rolls  serve  as  preparatory  cylinders,  in  which  case  they  bear 
towards  one  extremity  rectangular  grooves,  as  the  figure  exhibits.     Several  of  these 
large  grooves  are  bestudded  with  small  asperities  analogous  to  the  teeth  of  files,  for 
biting  tlie  lump  of  iron,  and  preventing  its  sliding.      On  a  level  with  the  under  side  of 
the  grooves  of  the  lower  cylinder,  there  is  a  plate  of  cast  iron  with  notches  in  its  edjje 
adapted  to  the  grooves.     This  piece,  c&Ued  the  apron,  rests  on  iron  rods,  and  serves  \o 
support  the  balls  and  bars  exposed  to  the  action  of  the  rollers,  and  to  receive  the  fragments 
of  ill-welded  metal,  which  fall  off  during  the  drawing.    The  housing  frames  in  which  the 
rollers  are  supported  and  revolve,  are  made  of  great  strength.      Their  height  is  5  feet ; 
their  thickness  is  1  foot  in  the  side  perpendicular  to  the  axis  of  the  cylinders,  and  10 
inches  in  the  other.    Each  pair  of  bearers  is  connected  at  their  upper  ends  by  two  iron 
rods,  on  which  the  workmen  rest  their  tongs  or  pincers  for  passing  the  lump  or  bar  from 
one  side  of  the  cylinders  to  the  other. 

The  cods  or  bushes  are  each  composed  of  two  pieces ;  the  one  of  hard  brass,  which 
presents  a  cylindrical  notch,  is  framed  into  the  other  which  is  made  of  cast  iron,  as  is 
clearly  seen  in  fig.  597. 

The  iron  bar  delivered  from  the  square  grooves,  is  cut  by  the  shears  into  short  lengths, 
which  are  collected  in  a  bundle  in  order  to  be  welded  together.  When  this  bundle  of 
bars  has  become  hot  enough  in  the  furnace,  it  is  conveyed  to  the  rollers ;  which  differ 
in  their  arrangement  according  as  they  are  meant  to  draw  iron  from  a  large  or  small 
piece.  The  first,  fig.  597,  possess  both  elliptical  and  rectangular  grooves ;  are  1  foot 
m  diameter  and  3  feet  long  between  the  bearers.  The  bar  is  not  finished  under  these 
cylinders,  but  is  transferred  to  another  pair,  whose  grooves  have  the  dunensions  proper 
for  the  bar,  with  a  round,  triangular,  rectangular,  or  fillet  form.  The  triangular  grooves 
made  use  of  for  square  iron,  have  for  their  profile  an  isosceles  triangle,  slightly  obtuse, 
80  that  the  space  left  by  the  two  grooves  together  may  be  a  rhombus,  differing  little 
from  a  square,  and  whose  smaller  diagonal  is  vertical.  When  the  bar  is  to  be  passed 
successively  through  several  grooves  of  this  kind,  the  larger  or  horizontal  diagonal  of 
each  fi)llowing  groove  is  made  equal  to  the  smaller  or  upright  of  the  preceding  one, 
whereby  the  iron  must  be  turned  one  fourth  round  at  each  successive  draught,  and  thus 
receive  pressure  in  opposite  directions.  Indeed,  the  bar  is  often  turned  in  succession 
through  the  triangular  and  rectangular  grooves,  that  its  fibres  may  be  more  accurately 
worked  together.  The  decrement  in  the  capacity  of  the  grooves  follows  the  proportion 
of  15  to  11. 

When  it  is  intended  to  reduce  the  iron  to  a  small  rod,  the  cylinders  have  such  a  diam- 
eter, that  three  may  be  set  in  the  same  housing  frahie.  The  lower  and  middle  cylinders 
are  employed  as  roughing  rollers,  while  the  upper  and  middle  oo«?s  are  made  to  draw  out 
the  rod.  When  a  rod  or  bar  is  to  be  drawn  with  a  channel  or  ^tter  in  its  face,  the 
grooves  of  the  rollers  are  suitably  formed. 


» 


1086 


IRON. 


IRON. 


1087 


To  draw  out  square  rods  of  a  very  small  size,  as  nail-rods,  a  system  of  small  rollers  is 
employed,  called  slitters.     Their  ridges  are  sharp-edged,  and  enter  into  the  opposite 


808 


.V^:lO 


H 


grooves  2|  inches  deep  ;  so  that  the  flat  bar  in 
passing  between  such  roUers  is  instantaneously 
divided  into  several  slips.  For  this  puipose 
the  roUers    represented  in  fig.  809  may  be 


809 


put  on  and  removed  from  the  shaft  at  plea 
sure. 

The  velocity  of  the  cylinders  varies  with 
their  dimensions.  In  one  work,  cylinders  for 
drawing  out  iron  of  from  one  third  to  two 
thirds  of  an  inch  thick,  make  140  revolutions 
per  minute  ;  while  those  for  iron  of  from  two 
thirds  of  an  inch  to  3  inches,  make  only  65. 
In  another  work,  the  cylinders  for  two  inch 
iron,  make  95  revolutions  per  minute ;  those 
for  iron  from  two  thirds  of  an  inch  to  an  inch 
and  a  third,  make  128;  and  those  for  bars 
from  one  third  to  two  thirds  of  an  inch,  150. 
The  roughing  roUers  move  with  only  one  third 
the  velocity  of  the  drawing  cylinders. 

The  shingling  and  plate-rolling  mill  is  rep- 
resented in  Jig.  808.  The  shingling  mill,  for 
converting  the  blooms  from  the  balling  fur- 
nace into  bars,  consists  of  two  sets  of  grooved 
cylinders,  the  first  being  called  puddling  rolls 
or  roughing  rolls ;  the  second  are  for  reducing 
or  drawing  the  iron  into  mill-bars,  and  are 
called  simply  rolls. 

a,  o,  a,  a,  are  the  powerful  uprights  or  stand- 
ards called  housing  frames,  of  cast  iron,  in  which 
the  gudgeons  of  the  rolls  are  set  to  revolve ; 
b,  6,  b,  b,  are  bolt  rods  for  binding  these  frames 
together  at  top  and  bottom ;  c,  are  the  roughing 
rolls,  having  each  a  seriesof  triangular  grooves, 
such  that  between  those  of  the  upper  and 
under  cjiinder,  rectangular  concavities  are 
formed  in  the  circumference  with  slightly 
sloping  sides.  The  end  groove  to  the  right 
of  c,  should  be  channelled  like  a  rough  file,  in 
order  to  take  the  better  hold  of  the  blooms,  or 
to  bite  the  metal,  as  the  workmen  say ;  and  give 
it  the  preparatory  elongation  for  entering  into 
and  passing  through  the  remaining  grooves 


till  it  comes  to  the  square  ones,  where  it  be- 
comes a  mill-bar.      d,  d,  are  the  smooth  cyl- 
inders, hardened  upon  the  surface,  or  chilled 
*"*>       *n       r^^  as  it  is  called,  by  being  cast  in  iron  moulds, 

for  rolling  iion  into  plates  or  hoops,  e,  e,  e,  e,  are  strong  screws  with  rectangular  threads, 
which  work  by  means  of  a  wrench  or  key,  into  the  nuts  c'  e'  e'  «',  fixed  in  the  standards ; 
they  serve  to  regulate  the  height  of  the  plummer  blocks  or  bearers  of  the  ^dgeons,  and 
thereby  the  distance  between  the  upper  and  under  cylinders.  /  is  a  junction  shaft  ;  g. 
g,  g,  are  solid  coupling  boxes,  which  embrace  the  two  separate  ends  of  the  shafts,  and  make 
them  turn  together.  A,  A,  are  junction  pinions,  whereby  motion  is  communicated  from  the 
driving  shaft  /,  through  the  under  pinion  to  the  upper  one,  and  thus  to  both  upper  and 
imder  rolls  at  once,  t,  i,  are  the  pinion  standards  in  which  their  shafts  run  ;  they  arc 
smaller  than  the  uprights  of  the  rolls,  fe,  fe,  are  screws  for  fastening  the  head  pieces  /  te 
the  top  of  the  pinion  standards.      All  the  standards  are  provided  with  sole  plates  m, 


frherehy  they  are  screwed  to  the  foundation  beams  n,  of  wood  or  preferably  iron,  as 
shown  by  dotted  lines  ;  o  o  are  the  binding  screw  bolts.  Each  pair  of  rolls  at  work  is 
kept  cool  by  a  small  stream  of  water  let  down  upon  it  from  a  pipe  and  stop-cock. 

In  the  cylinder  drawing,  the  workman  who  holds  the  ball  in  tonffs,  passes  it  into  the 
first  of  the  elliptical  grooves ;  and  a  second  workman  on  the  other  side  of  the  cylinders, 
receives  this  lump,  and  hands  it  over  to  the  first,  who  re-passes  it  between  the  rollers, 
after  bringing  them  somewhat  closer  to  each  other,  by  giving  a  turn  to  the  adjusting  pres- 
sure screws.  After  the  lump  has  passed  five  or  six  times  through  the  same  groove,  it  has 
got  an  elliptical  form,  and  is  called  in  England  a  bloom.  It  is  next  passed  through  a 
second  groove  of  less  size,  Avhich  stretches  the  iron  bar.  In  this  state  it  is  subjected  to 
a  second  pair  of  cylinders,  by  which  the  iron  is  drawn  into  flat  bars,  4  inches  broad  and 
half  an  inch  thick.  Fragments  of  the  ball  or  bloom  fall  round  about  the  cylinders ; 
which  are  afterwards  added  to  the  puddling  charge.  In  a  minute  and  a  half,  the  rude  lump 
IS  transformed  into  bars,  with  a  neatness  and  rapidity  which  the  inexperienced  eye  can 
hardly  follow.  A  steam  engine  of  thirty-horse  power  can  rough  doum  in  a  week,  200  tons 
of  coarse  iron. 

This  iron,  called  mill-bar  iron,  is  however  of  too  inferior  a  quality  to  be  employed  in 
any  machinery;  and  it  is  subjected  to  another  operation,  which  consists  in  welding 
several  pieces  together,  and  working  them  into  a  mass  of  the  desired  qualitv.  The  iron 
bars,  while  still  hot,  are  cut  by  the  shears  into  a  length  proportional  to  the  size  of  iron 
bar  that  is  wanted  ;  and  four  rows  of  these  are  usually  laid  over  each  other  into  a  heap 
or  pile,  which  is  placed  in  the  '^c-heating  furnace  above  described,  and  exposed  to  a  free 
circulation  of  heat ;  one  pile  being  set  crosswise  over  another.  In  a  half  or  three 
quarters  of  an  hour,  the  iron  is  hot  enough,  and  the  pieces  now  sticking  together,  are 
carried  in  successive  piles  to  the  bar-drawing  cylinders,  to  be  converted  into  strong  bars, 
which  are  reckoned  of  middle  quality.  When  a  very  tciigh  iron  is  wanted,  as  for  anchors, 
another  welding  and  rolling  must  be  given.  In  the  re-heating  ovens,  the  loss  is  from  8 
to  10  per  cent,  on  the  large  bar  iron,  and  from  10  to  12  in  smaUer  work.  A  ton  of  iron  con- 
sumes in  this  process  about  150  lbs.  of  coals. 

It  is  thought  by  many  that  a  purer  iron  is  obtained  bv  subjecting  the  balls  as  they 
come  out  of  the  puddling  furnace,  to  the  action  of  the  hammer  at  first,  than  to  the 
roughing  rollers  ;  and  that  by  the  latter  process  vitrified  specks  remain  in  the  metal,  which 
the  hammer  expels.  Hence,  in  some  works,  the  balls  are  first  worked  under  the  forge- 
hammer;  and  these  stampings  being  afterwards  heated  in  the  form  of  pies  or  cakes  piled 
over  each  other,  are  passed  through  the  roughing  rollers. 

Having  given  ample  details  concerning  the  manufacturing  processes  used  in  England 
for  making  cast  iron,  it  may  be  proper  to  subjoin  a  few  observations  upon  its  chemical 
constitution.     It  has  been  generaUy  believed  and  taught  that  the  dark  gray  cast  iron 
No.  1   or  No.  2,  contains  more  carbon  than  the  white  cast  iron ;  and  that  the  superior 
quality  of  the  former  in  tenacity  and  softness,  is  to  be  ascribed  to  that  excess.     But 
the  distinguished  German  metaUurgist,  M.  Karsten,  in  his  instructive  volume,  "  Hand- 
buch  der  Eisenhiittenkunde,"  or  manual  of  the  art  of  smelting  iron  ores,  has  proved,  on 
the  contrary,  that  the  white  cast  iron  contains  most  charcoal ;  that  this  substance  exists 
m  It  in  a  state  of  combination  with  the  whole  body  of  the  iron ;  that  the  foliated  or  la- 
mellar white  cast  iron  contains  as  much  carbon  as  iron  can  absorb  in  the  liquid  state-  and 
that  this  constitutes  a  compound  of  4  atoms  of  iron  combined  with  1  of  charcoal,  or  1124-6  • 
or  51  per  cent. ;  whereas  the  dark  gray  cast  iron  contains  generally  from  3  to  4  per 
cent.,  in  the  state  of  plumbago  merely  dispersed  through  the  metal.    He  has  further 
confirm^  his  opinion,  by  causing  the  white  variety  to  pass  into  the  gray,  and  recipro- 
cally.   Thus,  dark  gray  cast  metal  melted  and  suddenly  cooled,  gives  a  silvery  white 
metal,  hard  and  brittle.     On  the  other  hand,  when  the  white  cast  iron  is  cooled  very 
slowly  after  fusion,  the  condition  of  the  carbon  in  it  changes,  and  a  dark  ?ray  cast  iron 
is  obtamed.     These  phenomena  show  that  the  graphite  or  plumbago,  which  requires  a 
high  temperature  for  its  formation,  cannot  be  produced  but  bv  a  slow  coolinjr,  which  al- 
lows the  carbon  to  agglomerate  itself  in  the  iron  in  the  state  of  graphite;  while  under  a 
rapid  congelation,  the  carbon  remains  dissolved  in  the  mass,  and  produces  a  white  metal. 
Hence  we  may  understand  how  each  successive  fusion  of  dark  gray  iron  hardens  and  whitens 
V-  ?"1   *"/io"t^^t  ^^Jth  coke,  by  completing  that  chemical  dissolution  of  the  carbon  on 
which  the  white  state  depends. 

In  the  manufacture  of  the  blackest  No.  1  cast  iron,  it  sometimes  happens  that  a  con- 
siderable quantity  of  a  glistening  carburet  of  iron  appears,  floatin?  on  the  top  of  the 
metal  as  it  is  run  out  into  the  sand-moulds.  This  substance  is  called  kish  by  the 
iLnghsh  workmen  ;  and  it  affords  a  sure  test  of  the  good  state  of  the  furnace  and  qualitv 
of  the  iron.  ^       ■' 

The  most  remarkable  fact  relative  to  the  smelting  of  cast  iron,  is  the  difference  of  pro- 
dnct  between  the  workings  of  the  summer  and  the  winter  season,  though  all  the  material 
and  machinery  be  the  same.     In  fact,  no  cold-blast  furnace  will  carrv  so  great  a  burder 


1088 


IRON. 


in  summer  as  in  winter,  that  is,  afford  so  gieat  a  product  of  metal,  or  bear  so  great  • 
charge  of  ore  with  the  same  quantity  of  coke.     This  diiierence  is  undoubtedly  due  to  th€ 
dilated  and  humid  state  of  the  atmosphere  in  the  warm  season.     A  very  competent  judg« 
cf  this  matter,  states  the  diminution  in  summer  at  from  one  fifth  to  one  seventh,  indepen 
dcntly  of  deterioration  of  quality. 

Some  of  the  foreign  irons,  particularly  certain  Swedish  and  Russian  bars,  are  im- 
ported into  Great  Britain  in  large  quantities,  and  at  prices  much  greater  than  those  of 
the  English  bars,  and  therefore  the  modes  of  manufacturing  such  excellent  metal  deserve 
examination.  All  the  best  English  cast  steel,  indeed,  is  made  from  the  hoop  L  iron  from 
Dannemora,  in  Sweden. 

The  processes  pursued  in  the  smelting  works  of  the  Continent  have  frequently  in  view 
to  obtain  from  the  ore  malleable  iron  directly,  in  a  pure  or  nearly  pure  state.  The  furnaces 
used  for  this  purpose  are  of  two  kinds,  called  in  French,  1.  Fetiz  de  Loupcsy  or  Forges 
Catalanes ;   and  2.  Fourneaux  H  piece,  or  Forges  Mlemaivies. 

In  the  Catalan,  or  French  method,  the  ore  previously  roasted  in  a  kiln  is  aflen^'ards 
strongly  torrefied  in  the  forge  before  the  smelting  begins ;  operations  which  follow  in 
immediate  succession.  Ores  treated  in  this  way  should  be  very  fusible  and  very  rich  ; 
such  as  black  oxyde  of  iron,  hematites,  and  certain  spathose  iron  ores.  From  100 
parts  of  ore,  50  of  metallic  iron  have  been  procured,  but  the  average  product  is  35. 
The  furnaces  employed  are  rectangular  hearths, /g«.  811,  and  811,  the  water-blowing 

810  811 


03 

machine  being  employed  to  give  the  blast.  See  Metallurgy.  There  are  three 
varieties  of  this  forge ;  the  Catalan,  the  Navarrese,  and  the  Biscayan.  The  dimensions 
of  the  first,  the  one  most  generally  employed,  are  as  follows :  21  inches  long,  in  the 
lUrection  p  f,fig.  811;  18^  broad,  at  the  bottom  of  the  hearth  or  creuset,in.  the  line 
A  B ;  and  17  inches  deep,yi^.  810.  The  tuyere,  q  jo,  is  placed  9^  inches  above  the  bottom, 
«o  that  its  axis  is  directed  towards  the  opposite  side,  about  2  inches  above  the  bottom. 
But  it  must  be  moveable,  as  its  inclination  needs  to  be  changed,  according  to  the  stage 
of  the  operation,  or  the  quantity  of  the  ores.  It  is  often  raised  or  lowered  with  pellets 
of  clay ;  and  even  with  a  graduated  circle,  for  the  workmen  make  a  great  mystery  of 
this  matter.  The  hearth  is  lined  with  a  layer  of  brasque  (loam  and  charcoal  dust 
worked  together),  and  the  ore  after  being  roasted  is  sifted ;  the  small  powder  being  set 
aside  to  be  used  in  the  course  of  the  operation.  The  ore  is  piled  up  on  the  side  opposite 
to  the  blast  in  a  sharp  saddle  ridge,  and  it  occupies  one  third  of  the  furnace.  In  the  re- 
maining space  of  two  thirds,  the  charcoal  is  put.  To  solidify  the  small  ore  on  the  hearth, 
it  is  covered  with  moist  cinders  mixed  with  clay. 

The  fire  is  urged  with  moderation  during  the  first  two  hours,  the  workman  being 
continually  employed  in  pressing  down  more  charcoal  as  the  former  supply  burns 
awa}-,  so  as  to  keep  the  space  fiill,  and  prevent  the  ore  from  crumbling  down.  By  a 
blast  so  tempered  at  the  beginning,  the  ore  gets  well  calcined,  and  partially  reduced  in 
the  way  of  cementation.  But  after  two  hours,  the  full  force  of  the  air  is  given; 
at  which  period  the  fusion  ought  to  commence.  It  is  easy  to  see  whether  the  torre- 
faction  be  sufficiently  advanced,  by  the  aspect  of  the  flame,  as  well  as  of  the  ore, 
which  becomes  spongy  or  cavernous ;  and  the  workman  now  completes  the  fusion,  by 
detaching  the  pieces  of  ore  from  the  bottom,  and  placing  them  in  front  of  the  tuyere. 
When  the  fine  siftings  are  afterwards  thrown  upon  the  top,  they  must  be  watered, 
to  prevent  their  being  blown  away,  and  to  keep  them  evenly  spread  over  the  whole 
surface  of  the  light  fuel.  They  increase  the  quantity  of  the  products,  and  give  a  propel 
fusibility  to  the  scorioe.  When  the  scoriae  are  viscid,  the  quantity  of  siftings  must  be 
diminished  ;  but  if  thin,  they  must  be  increased.  The  excess  of  slag  is  allowed  to  run  oflT 
by  the  chic  or  floss  hole.  The  process  lasts  from  five  to  six  hours,  after  which  the  pasty 
mass  is  taken  out,  and  placed  under  a  hammer  to  be  cut  into  lumps,  which  are  afterwards 
forged  into  bars. 

Each  mass  presents  a  mixed  variety  of  iron  and  steel ;  in  proportions  which  may 
be  modified  at  pleasure  ;  for  by  using  much  of  the  siftinsrs,  and  making  the  tuj'cre  dip 
to  .vanJs  the  sole  of  the  hearth,  iron  is  the  chief  product ;   but  if  the  operation  be  con 


IRON. 


1089 


ducted  slowly,  with  a  small  quantity  of  siftings,  and  an  upraised  tuvtre,  the  quantity 
01  steel  IS  more  considerable.  This  primitive  process  is  favorably'  spoken  of  by  M. 
Brongniart.  The  weight  of  the  lump  of  metal  varies  from  200  to  400  pounds.  As  the 
consumption  of  charcoal  is  very  great,  amounting  in  the  Palatinate  or  Rheinkreis  to 
se^-en  linies  the  weight  of  iron  obtained,  though  in  the  Pyrenees  it  is  only  thrice,  the 
Catalan  forge  can  be  profitably  employed  only  where  wood  is  exceedingly  cheap  and 
abundant.  ^  ^  * 

The  Fmeauxdpihe  of  the  French,  or  Stuck-ofen  of  the  Germans,  resembles  ^^.885 
(Copper)  ;  the  tuyere  (not  shown  there)  having  a  dip  towards  the  bottom  of  the  hearth, 
where  the  smelted  matter  collects.  When  the  operation  is  finished,  that  is  at  least 
once  m  eveiy  24  hours,  one  of  the  sides  of  the  hearth  must  be  demolished,  to  take 
out  the  pasty  mass  of  iron,  more  or  less  pure.  This  furnace  holds  a  middle  place  in  the 
treatment  of  iron,  between  the  Catalan  forge  and  the  cast-iron  j7ow-q/c«,  or  hi-h-blast 
fhT^'^'tV  i'f  »;«^'^-oA«  are  from  10  to  15  feet  high,  and  about  3  feet  in  diameter  at 
the  hearth.  Most  usually  there  is  only  one  aperture  for  the  tuyere  and  for  working- 
with  a  smaU  one  for  the  escape  of  the  slag;  on  which  account,  the  bellows  are  removid 
o  make  way  for  he  lifting  out  of  the  lump  of  metal,  which  is  done  through  an  opening 
left  on  a  level  with  the  sole,  temporarily  closed  with  bricks  and  potters'  clay,  whUe  the 
furnace  is  in  action.  ^  ^»  "*** 

hnnni'  ""  WK  ^''""^  H^""'^!'  r^-  *-^  ^™ce  fiUed  with  charcoal,  fire  is  kindled  at  the 
fn  nh^r'n.t  r'^'^"'  ^\^^^^^  IS  lu  combustiou,  the  roastcd  ore  is  introduced  at  the  top 
m  alternate  charges  with  charcoal,  tiU  the  proper  quantity  has  been  introduced.  The  ore 
iron  Ar'T i,  ^^'^^"ever  it  comes  opposite  to  the  tuyere  the  slag  begins  to  flow, and  the 
nrnnnrr^  dowu  and  coUccts  at  the  bottom  of  the  hearth  into  the  mass  or  stuck  and  i^ 
proportion  as  this  mass  increases,  the  Jloss-hole  for  the  slag  and  the  tuyere  s  raisS 
higher     When  the  quantity  of  iron  accumulated  in  the  hearth  is  judg^  to  be  s«fficTent 

h^  r^lr'f"^"^  '-^P^'^'  '^^  r"T  ^'^  '^^^^  ^^'  '^'  "ttle  brick  waU^is  taken  dowi,  and 
the  mass  of  iron  is  removed  by  rakes  and  tongs.  This  mass  is  then  flattened  und^;  the 
hammer,  mto  a  cake  from  3  to  4  inches  thick,  and  is  cut  into  two  lim^ps,  whTch  are  sul^ 
mitted  to  a  new  operation ;  where  it  is  treated  in  a  peculiar  refinery,  lined  with  char^al 
Srasque,  and  exposed  to  a  nearly  horizontal  blast.     The  above  maS    sei^eT  in  the^^ 

LlTnfT  T^%'',  ^'"'"^  ^'^T  *^^  '^y^^^'  ^  P^^ti^'^  «f  the  meial  flows iown  to  tie 
bottom  of  the  hearth,  loses  its  carbon  in  a  bath  of  rich  slags  or  fused  oxydes  and  foiros 

thereby  a  mass  of  iron  thoroughly  refined.  The  portion  that  remains  Tthe  tongsZ! 
nishes  steel,  which  is  drawn  out  into  bars.  ^ 

This  process  is  employed  in  Carniola  for  smeltin*  a  erannl^r  nvv,lo  «r  ,V/.«    ti. 
or  ^uck  amounts  to  from  15  to  20  hundred  weigh,"  ?Srtaeh%tafrof  STtSf 
Eight  strong  D,en  are  required  to  lift  it  out,  and  to  earr,-  it  under  aCge  hammer  wS 

eras  aWe'tecribel'"  The^r  '"'"•     ''"'^  "«  afterwards  refined  a^dZw  i^S 
oars  as  aoove  oescnbed.      Ihese  furnaces  are  now  almost  n>n»r>iiU' o>.onj„.~]     _  .u 
Continent,  in  favor  of  charcoal  Mgh  or  blast  furmces  S^^'^^i  abandoned  on  the 

tig.  385  represents  a  shachtofin  (but  without  the  tuyere, which  may  be  sunoosed  to  h, 
m  the  usual  pace),  and  is,  UUe  all  the  continental  Hail,  F<mrnm^\^SkM^J^^, 
of'theZlS'''  "^  "'  '""'''"■■*>     ■?•"  '"^'Se  is  put  in  at  the  th™at!Te„  the  slm^! 

:n  :f xtr  r5:=e''^itri^^^^^^^ 

fhnhSn    ^^P^'^I^V  t>ottom  of  the  hearth  is  constracted  of  two  lar<'e  stones    and 

lr.n  hT   ^^'^  ""^  one  great  stone,  caUed  in  German,  rncksiem  (black  sSSe)  whfch  Sl 
French  have  corrupted  into  rustine.     In  other  countries  of  th^  rvJ^f-       V  .u  '  v    V         ® 

cast-iron,  130  pounds  of  chtLTwereioSfmed    '"  '^'f'"''^"""'"  "^  '"O  Po.unds  of 
beUows.,  mounted  with  leather.  *'"^"«»''<'-    That  furnace  was  worked  with  foi^e 


1090 


moN. 


The  decarburation  of  cast-iron  is  merely  a  restoration  of  the  carbon  to  the  9url*ce,  m 
tracing  inversely  the  same  progressive  steps  as  had  carried  it  into  the  interior  during  the 
smelling  of  the  ore.  The  oxygen  of  the  air,  acting  first  at  the  surface  of  the  cabt  metal, 
upon  the  carbon  which  it  finds  there,  burns  it :  fresh  charcoal,  oozing  from  the  interior, 
comes  then  to  occupy  the  place  of  what  had  been  dissipated ;  till,  finally,  the  -yvhole  car- 
bon is  transferred  from  the  centre  to  the  surface,  and  is  there  converted  into  either  car- 
Iwnic  acid  gas,  or  oxyde  of  carbon ;  for  no  direct  experiment  has  hitherto  proved  which 
of  these  is  the  precise  product  of  this  combustion. 

This  diffusibility  of  carbon  through  the  whole  mass  of  iron  constitutes  a  movement  by 
means  of  which  cast-iron  may  be  refined  even  without  undergoing  fusion,  as  is  proved  by 
a  multitude  of  phenomena.  Every  workman  has  observed  that  steel  loses  a  portion  of 
its  steely  properties  every  time  it  is  heated  in  contact  with  air. 

On  the  above  principle,  cast-iron  may  be  refined  at  one  operation.  Three  kinds  of  iron 
are  susceptible  of  this  continuous  process : — 1.  The  speckled  cast-iron,  which  contains 
such  a  proportion  of  oxygen  and  carbon  as  with  the  oxygen  of  the  air  and  the  carbon  of 
the  fuel  may  produce  sufficient  and  complete  saturation,  but  nothing  in  exce&i  2.  The 
dark  gray  cast-iron.  3.  The  white  cast-iron.  The  nature  of  the  crude  met*i  requires 
variations  both  in  the  forms  of  the  furnaces,  and  in  the  manipulations. 

Indeed,  malleable  iron  may  be  obtained  directly  from  the  ores  by  one  fusion.  This 
mode  of  working  is  practised  in  the  Pyrenees  to  a  considerable  extent.  All  the  ores  of 
iron  are  not  adapted  for  this  operation.  Those  in  which  the  metallic  oxyde  is  mixed  with 
much  earthy  matter,  do  not  answer  well;  but  those  composed  of  the  pure  black  onys^y 
red  oxyde,  and  carbonate,  succeed  much  better.  To  extract  the  metal  from  such  ores,  it 
is  sufficient  to  expose  them  to  a  high  temperature,  in  contact  either  with  charcoal,  or 
with  carbonaceous  gases ;  the  metallic  oxyde  is  speedily  reduced.  But  when  several 
earths  are  present,  these  tend  continually,  during  the  vitrification  which  they  suffer,  to 
retain  in  their  vitreous  mass  the  unreduced  oxyde  of  iron.  Were  such  earthy  ores,  as 
our  ironstones,  to  be  put  into  the  low  furnaces  called  Catalan^  through  which  the  charges 
pass  with  great  rapidity,  and  in  which  the  contact  with  the  fuel  is  merely  momentary, 
there  would  be  found  in  the  crucible  or  hearth  merely  a  rich  metallic  glass,  instead  of  a 
lump  of  metal. 

In  smelting  and  refining  by  a  continuous  operation,  three  diflerent  stages  may  be  dis- 
tinguished :  1.  The  roasting  of  the  ore  to  expel  the  sulphur,  which  would  be  less 
easily  separated  afterwards.  The  roasting  dissipates  likewise  the  water,  the  carbonic 
acid,  and  any  other  volatile  substances  which  the  minerals  may  contain.  2.  The  deoxy- 
dizement  and  reduction  to  metal  by  exposure  to  charcoal  or  carbureted  vapors.  3.  The 
melting,  agglutination,  and  refining  of  the  metal  to  fit  it  for  the  heavy  hammers  where 
it  gets  nerve.  There  are  several  forges  in  which  these  three  operations  seem  to  be  con 
founded  into  a  single  one,  because,  although  still  successive,  they  are  practised  at  one 
single  heating  without  interruption.  In  other  forges,  the  processes  are  performed  sepa- 
rately, or  an  interval  elapses  between  each  stage  of  the  work.  Three  systems  of  this 
kind  are  known  to  exist: — 1.  The  Corsican  method;  2.  The  Catalan  with  wood  char- 
coal; and  3.  The  Catalan  with  coke. 

The  furnaces  of  Corsica  are  a  kind  of  semicircular  basins,  18  inches  in  diameter,  and 
6  inches  deep.  These  are  excavated  in  an  area,  or  a  small  elevation  of  masonry,  8  or  10 
feet  long  by  5  or  6  broad,  and  covered  in  with  a  chimney.  This  area  is  quite  similar  to 
that  of  the  ordinary  hearths  of  our  blast-furnaces. 

The  tuyere  stands  5  or  6  inches  above  the  basin,  and  has  a  slight  inclination  down- 
wards. In  Corsica,  and  the  whole  portion  of  Italy  adjoining  the  Mediterranean  shores, 
the  iron  ore  is  an  oxyde  similar  to  the  specular  ore  of  the  Isle  of  Elba.  This  ore  con- 
tains a  little  water,  some  carbonic  acid,  occasionally  pyrites,  but  in  small  quantity.  Be- 
fore deoxydizing  the  ore,  it  is  requisite  to  expel  the  water  and  carbonic  acid  combined 
with  the  oxyde,  as  well  as  the  sulphur  of  the  pyrites. 

The  operations  of  roasting,  reduction,  fusion,  and  agglutination,  are  executed  in  the 
same  furnace.  These  are  indeed  divided  into  two  stages,  but  the  one  is  a  continuation 
of  the  other.  In  the  first,  the  two  primary  operations  are  performed  at  once ; — the 
reduction  of  a  portion  of  the  roasted  ore  is  begun  at  the  same  time  that  a  portion  of 
the  raw  ore  is  roasted :  these  two  substances  are  afterwards  separated.  In  the  second 
stage,  the  deoxydizement  of  the  metal  is  continued,  which  had  begun  in  the  preceding 
stage ;  it  is  then  melted  and  agglutinated,  so  as  to  form  a  ball  to  b«  submitted  to  the 
forge-hammer. 

The  roasted  pieces  are  broken  down  to  the  size  of  nuts,  to  make  the  reduction  of  the 
metal  easier.  In  executing  the  first  step,  the  basin  and  area  of  the  furnace  must  be 
lined  with  a  brasq-ue  of  charcoal  dust,  3,  4,  or  even  5  inches  thick :  over  this  brusque  a 
mound  is  raised  with  lumps  of  charcoal,  very  hard,  and  4  or  5  inches  high.  A  semi- 
circle is  formed  round  the  tuj^ere,  the  inner  radius  of  whicli  is  5  or  6  inches.  This  mass 
oC  charcoal  is  next  surrounded  with  mother  pile  of  the  roasted  and  broken  ores,  whicli 


IRON. 


1091 


must  be  covt-rd  with  charcoal  dust.    The  whole  is  sustained  with  large  blocks  of  the 
raw  ore,  which  form  externally  a  third  wall. 

These  three  piles  of  charcoal,  with  roasted  and  unroasted  ore,  are  raised  m  three  suc- 
cessive beds,  each  7  inches  thick :  they  are  separated  from  each  other  by  a  layer  of  char- 
coal dust  of  about  an  inch,  which  makes  the  whole  24  inches  high.  This  is  afterwards 
covered  over  with  a  thick  coat  of  pounded  charcoal. 

The  blocks  of  raw  ore  which  compose  the  outward  wall  form  a  slope ;  the  larger  and 
stronger  pieces  are  at  the  bottom,  and  the  smaller  in  the  upper  part.  The  large  block* 
are  sunk  very  firmly  into  the  charcoal  dust,  to  enable  them  better  to  resist  the  pressure 
from  within. 

On  the  bottom  of  the  semicircular  well  formed  within  the  charcoal  lumps,  kindled  pieces 
are  thrown,  and  over  these,  pieces  of  black  charcoal ;  after  which  the  blast  of  a  water- 
blowing  machine  (trompe)  is  given.  The  fire  is  kept  up  by  constantly  throwing  char- 
coal into  the  central  well.  At  the  beginning  of  the  operation  it  is  thrist  down  with 
wooden  rods,  lest  it  should  affect  the  building  ;  but  when  the  heat  becomes  too  intense 
for  the  workmen  to  come  so  near  the  hearth,  a  long  iron  rake  is  employed  for  the  pur- 
pose. At  the  end  of  about  3  hours,  the  two  processes  of  roasting  and  reduction  are  com- 
monly finished  :  then  the  raw  ore  no  longer  exhales  any  fumes,  and  the  roasted  ore,  being 
softened,  unites  into  lumps  more  or  less  coherent. 

The  workman  now  removes  the  blocks  of  roasted  ore  which  form  the  outer  casing, 
rolls  them  to  the  spot  where  they  are  to  be  broken  into  small  pieces,  and  pulls  dowa  ihe 
brasque  (small  charcoal)  which  surrounds  the  mass  of  reduced  ore. 

The  second  operation  is  executed  by  cleaning  the  basin,  removing  the  slags,  covering 
the  basin  anew  with  2  or  3  brasques  (coats  of  pounded  charcoal),  and  piling  up  to  the 
right  and  the  left,  two  heaps  of  charcoal  dust.  Into  the  interval  between  these  conical 
piles  two  or  three  baskets  of  charcoal  are  cast,  and  on  its  top  some  cakes  of  the  reduced 
crude  metal  being  laid,  the  blast  is  resumed.  The  cakes,  as  they  heat,  undergo  a  sort 
of  liquation,  or  sweating,  by  the  action  of  the  earthy  glasses  on  the  unreduced  black 
oxyde  present.  Very  fusible  slags  flow  down  through  the  mass ;  and  the  iron,  reduced 
and  melted,  passes  finally  through  the  coals,  and  falls  into  the  slag  basin  below.  To  the 
first  parcel  of  cakes,  others  are  added  in  succession.  In  proportion  as  the  slags  pro- 
ceeding from  these  run  down,  and  the  melted  iron  falls  to  the  bottom,  the  thin  slag  is  run 
.  off  by  an  upper  overflow  or  chio  hole,  and  the  reduced  iron  kept  by  the  heat  in  the  pasty 
condition,  remains  in  the  basin :  all  its  parts  get  agglutinated,  forming  a  soft  mass,  which 
is  removed  by  means  of  a  hooked  pole  in  order  to  be  forged.  Each  lump  or  bloom  of 
malleable  iron  requires  3  hours  and  a  half  for  its  production. 

The  iron  obtained  by  this  process  is  in  general  soft,  very  malleable,  and  but  little 
steely.  In  Corsica  four  workmen  are  employed  at  one  forge.  The  produce  of  their 
labor  is  only  about  4  cwts.  of  iron  from  10  cwts.  of  ore  and  20  of  charcoal,  mingled 
with  wood  of  beech  and  chestnut.  Though  their  ore  contains  on  an  average  65  per  cent, 
of  iron,  only  about  40  parts  are  extracted ;  evincing  a  prodigious  waste,  which  remains 
in  the  slags. 

The  difference  between  the  Corsican  and  the  Catalonian  methods  consists  in  the  latter 
roasting  the  ore  at  a  distinct  operation,  and  employing  a  second  one  in  the  reduction 
agglutination,  and  refining  of  the  metal.  In  the  Catalonian  forges,  100  pounds  of  iron 
are  obtained  from  300  pounds  of  ore  and  310  pounds  of  charcoal;  belhg  a  produce  of 
only  33  per  cent.  It  may  be  concluded  that  there  is  a  notable  loss,  since  the  sparry  iron 
ores,  which  are  those  principally  smelted,  contain  on  an  average  from  54  to  56  per  cent, 
of  iron.  The  same  ores,  smelted  in  the  ordinary  blast  furnace,  produce  about  45  per  cent' 
of  cast  iron. . 

On  the  Continent,  iron  is  frequently  refined  from  the  cast  metal  of  the  blast  fur- 
naces  by  three  operations,  in  three  diflerent  ways.  In  one,  the  pig  being  melted, 
with  aspersion  of  water,  a  cake  is  obtained,  "which  is  again  melted  in  order  to  form 
a  second  cake.  This  being  treated  in  the  refinery  fire,  is  then  worked  into  a  bloom.  In 
another  system,  the  pig  iron  is  melted  and  cast  into  plates  :  these  are  melted  anew  in 
order  to  obtain  crude  balls,  which  are  finaUy  worked  into  blooms.  In  a  third  mode  of 
manufacture,  the  pig-iron  is  melted  and  cast  into  plates,  which  are  roasted,  and  then  stronglv 
heated,  to  form  a  bloom.  ^ 

The  French  fusible  ores,  such  as  the  silicates  of  iron,  are  very  apt  to  smelt  into  white 
cast  iron.  An  excess  of  fluxes,  light  charcoals,  too  strong  a  blast,  produce  the  same  results. 
A  surcharge  of  ores  which  deranges  the  furnace  and  aflbrds  impure  slags  mLxed  with 
much  iron,  too  rapid  a  slope  in  the  boshes,  too  low  a  degree  of  heat,  and  too  great  con- 
densation of  the  materials  in  the  upper  part  of  the  furnace  ;  all  tend  also  to  produce  • 
white  cast  iron.  In  its  state  of  perfection,  white  cast  iron  has  a  silver  color,  and  a 
bnght  metallic  lustre.  It  is  employed  frequently  in  Germany  for  the  manufacture  of 
Jteel,  and  is  then  called  steel  Jhss,  or  lamellar  foss,  a  title  which  it  stiU  retains,  though  it 
be  hardly  sUver  white,  and  have  ceased  to  be  foliated.    When  its  color  takes  a  bluish- 


1092 


moN. 


gray  tinge,  and  its  fracture  appears  striated  or  splintery,  or  when  it  exhibits  gray  spota^ 
it  is  then  styled  Jlowerjloss,  In  a  third  species  of  white  cast  iron  we  observe  still  much 
lustre,  but  its  color  verges  uiwn  gray,  and  its  texture  is  variable.  Its  fracture  has  been 
sometimes  compared  to  that  of  a  broken  cheese.  This  variety  occurs  very  frequently. 
It  is  a  white  cast  iron,  made  by  a  surcharge  of  ore  in  the  furnace.  If  the  white  color 
becomes  less  clear  and  turns  bluish,  if  its  fracture  be  contorted,  and  cofatains  a  great  many 
empty  spaces  or  air-cells,  the  metal  takes  the  name  of  cavemous-JlosSf  or  tender-floss.  The 
whitest  metal  cannot  be  employed  for  casting.  When  the  white  is  mixed  with  the  gray 
cast  iron,  it  becomes  riband  or  trout  cast  iron. 

The  German  refining  forge, — Figs,  812,  813  represent  one  of  the  numerous  refinerj 

818 


furnaces  so  common  in  the  Hartz.  The  example  is  taken  from  the  Mandelholz  works^ 
in  the  neighborhood  of  Elbingerode.  Fig.  813  is  an  elevation  of  this  forge,  d  is  the 
refinery  hearth,  provided  with  two  pairs  of  bellows.  Fig.  812  is  a  vertical  section, 
showing  particularly  the  construction  of  the  crucible  or  hearth  in  the  refinery  forge  d. 
c  is  an  overshot  water  wheel,  which  gives  an  alternate  impulsion  to  the  two  bellows  a  b 
by  means  of  the  revolving  shaft  c,  and  the  cams  or  tappets  dfeg, 

D,  the  hearth,  is  lined  with  cast  iron  plates.  Through  the  pipe  I,  cold  water  may  be 
introduced,  under  the  bottom  plate  wi,  in  order  to  keep  down,  when  necessary,  the  tem- 
perature of  the  crucible,  and  facilitate  the  solidification  of  the  loupe  or  bloom.  An  orifice 
n,  fi(^s.  812,  813,  called  the  chio  (floss  hole),  allows  the  melted  slag  or  cinder  to  flow 
off  from  the  surface  of  the  melted  metal.  The  copper  pipe  or  nose  piece  p,  fig.  811, 
conducts  the  blast  of  both  bellows  into  the  hearth,  as  shown  at  b  ar,  fig.  813,  and  d  g  p, 

fig.  811. 

The  substance  subjected  to  this  mode  of  refinery,  is  a  gray  carbonaceous  cast  iron, 
from  the  works  of  Rothehiitte.  The  hearth  d,  bemg  filled  and  heaped  over  with  live 
charcoal,  upon  the  side  opposite  to  the  tuyere  x,  figs.  812,  813,  long  pigs  of  cast  iron  are 
laid  with  their  ends  sloping  downwards,  and  are  drawn  forwards  successively  into  the 
hearth  by  a  hooked  poker,  so  that  the  extremity  of  each  may  be  plunged  into  the  middle  of 
the  fire,  at  a  distance  of  6  or  8  inches  from  the  mouth  of  the  tuyere.  The  workman  pro- 
ceeds in  this  way,  till  he  has  melted  enough  of  metal  to  form  a  loupe.  The  cast  iron,  on 
melting,  falls  down  in  drops  to  the  bottom  of  the  hearth ;  being  covered  by  the  fused  slags, 
or  vitreous  matters  more  or  less  loaded  with  oxyde  of  iron.  After  running  them  off  by 
the  orifice  n,  he  then  works  the  cast  iron  by  powerful  stirring  with  an  iron  rake  (ringard), 
till  it  is  converted  into  a  mass  of  a  pasty  consistence. 

During  this  operation,  a  portion  of  the  carbon  contained  in  the  cast  iron  combines 
with  the  atmospherical  oxygen  supplied  by  the  beUovrs,  and  passes  off  in  the  form  of 
carbonic  oxyde  and  carbonic  acid.  When  the  lump  is  coagulated  sufficiently,  the  workman 
turns  it  over  in  the  hearth,  then  increases  the  heat  so  as  to  melt  it  afresh,  meanwhile 
exposing  it  all  round  to  the  blast,  in  order  to  consume  the  remainder  of  the  carbon,  that 
IS,  till  the  iron  has  become  ductile,  or  refined.  If  one  fusion  should  prove  inadequate  to 
tlus  effect,  two  are  given.  Before  the  conclusion,  the  workman  runs  off  a  second 
stratum  of  vitreous  slag,  but  at  a  higher  level,  so  that  some  of  it  may  remain  upon  the 
metal. 

The  weight  of  such  a  loupe  or  bloom  is  about  2  cwts.,  being  the  product  of  2  cwts.  and 

l^  of  pig  iron ;  the  loss  of  weight  is  therefore  about  26  per  cent.  149  pounds  of  charcoal 
are  consumed  for  every  100  pounds  of  bar  iron  obtained.  The  whole  operation  lasts 
about  5  hours.  The  bellows  are  stopped  as  soon  as  the  bloom  is  ready ;  this  is  immedi- 
ately transferred  to  a  forge  hanmier,  such  as  is  represented  fig.  816 ;  the  cast  iron  head 
of  which  weighs  8  ot  9  cwts.  The  bloom  is  greatly  condensed  thereby,  and  discharges 
a  considerable  quantity  of  semi-fluid  cinder.    The  lump  is  then  divided  by  the  hammer 


t 


, 


{ 


IRON. 


1093 


ana  a  chisel  into  4  or  6  pieces,  which  are  reheated,  one  after  another,  in  the  same  refinery 
fire,  in  order  to  be  forged  into  bars,  while  another  pi?  of  cast  iron  is  laid  in  its  place,  to 
prepare  for  the  formation  of  a  new  bloom.  The  above  process  is  called  by  the  Germans 
klump-frischen,  or  lump-refining.  It  differs  from  the  durch-brech-frischen,  because  in  the 
latter,  the  lump  is  not  turned  over  in  mass,  but  is  broken,  and  exposed  in  separate  pieces 
successively  to  the  refining  power  of  the  blast  near  the  tuyere.  The  French  call  this  af. 
linage  par  portions ;  it  is  much  lighter  work  than  the  other. 

The  quality  of  the  iron  is  tried  in  various  ways ;  as  first,  by  raising  a  bar  by  one  end, 
with  the  two  hands  over  one's  head,  and  bringing  it  forcibly  down  to  strike  across  a  nar- 
row anvil  at  its  centre  of  percussion,  or  one  third  from  the  other  extremity  of  the  bar ;  after 
which  it  may  be  bent  backwards  and  forwards  at  the  place  of  percussion  several  times ; 
2.  a  heavy  bar  may  be  laid  obliquely  over  props  near  its  end,  and  struck  strongly  with  a 
hammer  with  a  narrow  pane,  so  as  to  curve  it  in  opposite  directions;  or  whUe  heated 
to  redness,  they  may  be  kneed  backwards  and  forwards  at  the  same  spot,  on  the  edge  of 
the  anvU.  This  is  a  severe  trial,  which  the  hoop  L,  Swedish  iron,  bears  surprisin«'ly, 
emitting  as  it  is  hammered,  a  phosphoric  odor,  peculiar  to  it  and  to  the  bar  in/Tof 
Ulverstone,  which  also  resembles  it,  in  furnishing  a  ?ood  steel.  The  forging  of  a  horse- 
shoe is  reckoned  a  good  criterion  of  the  quality  of  iron.  Its  freedom  from  flaws  is 
detected  by  the  above  modes ;  and  its  linear  strength  may  be  determined  by  suspendin*' 
a  scale  to  the  lower  end  of  a  hard-drawn  wire,  of  a  given  size,  and  adding  wei^^hts  tiU 
the  wire  breaks.  The  treatises  of  Barlow  and  Tredgold  may  be  consulted  with  Advan- 
tage on  the  methods  of  proving  the  strength  of  different  kinds  of  iron,  in  a  great  variety 
of  circumstances.  ^  o  j 

Steel  of  cementation,  or  blistered  steel  and  cast  steel,  are  treated  under  the  article  Steex. 
But  since  m  the  conversion  of  cast  iron  into  wrought  iron,  by  a  very  sUght  difference  in 
the  manipulations,  a  species  of  steel  may  be  produced  called  naiural  steeL  I  shaU  describe 
this  process  here. 

Fig.  814  is  a  view  of  the  celebrated  steel  iron  works,  caUed  Konigshutte,  (kins' s-forse). 
in  Upper  Silesia,  being  one  of  the  best  arranged  in  Germany,  for  smelUng  iron  ore  by 


11     TV 


71      TV 


means  of  coke.  The  front  shown  here  is  about  400  English  feet  long,  a  a  are  two  blast 
furnaces.  A  third  blast  furnace,  all  like  the  English,  is  situated  to  the  left  of  one  of  the 
towers  6.  6  6  are  the  charging  towers,  into  which  the  ore  is  raised  by  machinery  from 
the  level  of  the  store-houses  /  /,  up  to  the  mouth  of  the  furnaces  aa  ;  cc  point  to  the 
positions  of  the  boilers  of  the  two  steam  engines,  which  drive  two  cylinder  bellows  at  / 
n  nn  n  are  arched  cellars  placed  below  the  store-houses  /  /,  for  containing  materials  and 
tools  necessary  for  the  establishment. 

Figs.  810,  816,  are  vertical  sections  of  the  forge  of  Konigshiitte,  for  making  natural 

steel  ;^g.  810  being  drawn  in  the  line  A  b  of 
the  plan,  ^g.  811.  a  is  the  bottom  of  the  hearth, 
consisting  of  a  fire-proof  gritstone ;  6  is  a  space 
filled  vrith  small  charcoal,  damped  with  water, 
under  which,  at  n,  in  fig,  815,  is  a  bed  of  well 
rammed  clay ;  d  is  a  plate  of  cast  iron,  which  lines 
the  side  of  the  hearth  called  ruckstein  (backstone) 
in  German,  and  corrupted  by  the  French  into 
rustine ;  f  is  the  plate  of  the  counter-blast ;  g  the 

ft.^-  ^  4k    fi       1  1-       ,    .      P^*^^  °**  ^^^  ^^^^  of  the  tuyere ;  behind,  upon  the 

face  ^,  the  fire-place  or  hearth  is  only  5|  inches  deep;  in  front  as  well  as  upon  the 

ateral  faces,  it  is  18  inches  deep.     By  means  of  a  mound  made  of  dry  charcoal,  the  pos- 
terior face  d  IS  raised  to  the  height  of  the  face  /.     t,  fig,  811,  is  the  floss-hole,  by  which 
the  slags  are  run  off  from  the  hearth  during  the  workin-  and  through  which,  by  removin- 
some  bricks,  the  lump  of  steel  is  taken  out  when  finished. 
klm  are  pieces  of  cast  iron,  for  confining  the  fire  in  front,  that  is,  towards  the  side  where 

•f  I!2  .f  ^"  v^*"**^^'  ""  '^  ^^^  ^^^^^  «^  the  floor  of  the  works;  p  a  copper  tuyere;  it  is 
situated  4|  mches  above  the  bottom  a,  slopes  5  degrees  towards  it,  and  advances  4  inches 
12  lu  A  .°'',^e-place,  where  it  presents  an  orifice,  one  half  inch  in  horizontal 
lengtli,  and  one  inch  up  and  down ;  q  the  nose  pipes  of  two  beUows,  like  those  represented 


1094 


IRON. 


in  fig.  813,  and  under  Silver;  the  round  orifice  of  each  of  them  within  the  tuyere  being 
one  inch  in  diameter,  r  is  the  lintel  or  top  arch  of  the  tuyere,  beneath  which  is  seen  the 
cross  section  of  the  pig  of  cast  iron  under  operation. 

For  the  production  of  natural  steel,  a  white  cast  iron  is  preferred,  which  contains  little 
carbon,  which  does  not  flow  thin,  and  which  being  cemented  over  or  above  the  wind,  falls 
down  at  once  through  the  blast  to  the  bottom  of  the  hearth  in  the  state  of  steel.  With 
this  view,  a  very  flat  fire  is  used  ;  and  should  the  metal  run  too  fluid,  some  malleable 
lumps  are  introduced  to  give  the  mass  a  thicker  pasty  consistence. 

If  the  natural  steel  be  supposed  to  contain  too  little  carbon,  which  is  %  very  rare  case, 
the  metal  bath  covered  with  its  cinder  slag,  is  diligently  stirred  with  a  wo'vlen  i)ole,  or  it 
may  receive  a  little  of  the  more  highly  carbureted  iron.  If  it  contains  the  right  dose  of 
carbon,  the  earthy  and  other  foreign  matters  are  made  progressively  to  sweat  out,  into  the 
supernatant  slag.  When  the  mass  is  found  by  the  trial  of  a  sample  to  be  completely  con- 
verted, and  has  acquired  the  requisite  stitfness,  it  is  lifted  out  of  the  furnace,  by  the  open- 
ing in  front,  subjected  to  the  forge  hammer,  and  drawn  into  bars.  In  Sweden,  the  cast 
iron  pigs  are  heated  to  a  cherry-red,  and  in  this  state  broken  to  pieces  under  the  hammer, 
before  they  are  exposed  in  the  steel  furnace.  These  natural  steels  are  much  employed  on 
the  Continent  in  making  agricultural  implements,  on  account  of  their  cheapness.  The 
natural  steel  of  Styria  is  regarded  as  a  very  good  article. 

Wootz  is  a  natural  steel  prepared  from  a  black  ore  of  iron  in  Hindostan,  by  a  process 
analogous  to  that  of  the  Catalan  hearth,  but  still  simpler.  It  seems  to  contain  a  minute 
portion  of  the  combustible  bases  of  alumina  and  silica,  to  which  its  peculiar  hardness 
when  tempered  may  possibly  be  ascribed.  It  is  remarkable  for  the  property  of  assuming 
a  damask  surface,  by  the  action  of  dilute  sulphuric  acid,  after  it  has  been  forged  and 
polished.  See  Damascus  and  Steel. 
Fig.  816  is  the  German  forge-hammer ;  to  the  left  of  1,  is  the  axis  of  the  rotatory 

cam,  2,  3,  consisting  of  8  sides, 
each  formed  of  a  strong  broad  bar 
of  cast  iron,  which  are  joined  to- 
gether to  make  the  octagon  wheel. 
4,  5,  6,  are  cast  iron  binding  rings 
or  hoops,  ii.ade  fast  by  wooden 
wedges.  6,  6,  are  standards  of  the 
frame-work  e,  /,  wi,  in  which  the 
helve  of  the  forge-hammer  has  its 
fulcrum  near  u.  h,  the  sole  part 
of  the  frame.  Another  cast  iron 
base  or  sole  is  seen  at  m.  n  is  a 
strong  stay,  to  strengthen  the 
frame-work.  At  r  two  parallel 
hammers  are  placed,  with  cast- 
iron  heads  and  wooden  helves,  s  is  the  anvil,  a  very  massive  piece  of  cast  iron.  /  is  tho 
end  of  a  vibrating  beam,  for  throwing  back  the  hammer  from  it  forcibly  by  recoil,  ar  y  is 
the  outline  of  the  water-wheel  which  drives  the  whole.  The  cams  or  tappets  are  shown 
mounted  upon  the  wheel  6,  g,  6. 

Analysis  of  irons. — Oxydized  substances  cannot  exist  in  metallic  iron,  and  the  foreign 
substances  it  does  contain  are  present  in  such  small  quantities,  that  it  is  somewhat 
difllcult  to  determine  their  amount.  The  most  intricate  point  is,  the  proportion  of 
carbon.  The  free  carbon,  which  is  present  only  in  gray  cast  iron,  may,  indeed,  be  deter- 
mined nearly,  for  most  of  it  remains  after  solution  of  the  metal  in  acids.  The  combined 
charcoal,  however,  changes  by  the  action  of  muriatic  acid  into  gas  and  oil ;  sulphuric  acid 
also  occasions  a  great  loss  of  carbon,  and  nitric  acid  dissipates  it  almost  entirely.  Either 
nitre  or  chloride  of  silver  may  be  employed  to  ascertain  the  amount  of  carbon ;  but  when 
the  iron  contains  chromium  and  much  phosphorus,  the  determination  of  the  carbon  is  at- 
tended with  many  difficulties. 

The  quantity  of  sulphur  is  always  so  small,  that  it  can  scarcely  be  ascertained  by  the 
weight  of  the  precipitate  of  sulphate  of  barjles  from  the  solution  of  the  iron  in  nitro- 
muriatic  acid.  The  iron  should  be  dissolved  in  muriatic  acid ;  and  the  hydrogen,  as  it 
escapes  charged  with  the  sulphur,  should  be  passed  through  an  acidulous  solution  of 
acetate  of  lead.  The  weight  of  the  precipitated  sulphuret  shows  the  amount  of  sulphur, 
allowing  13-45  of  the  latter  for  100  of  the  former.  In  this  experiment  the  metal  should 
be  slowly  acted  upon*by  the  acid.  Cast  iron  takes  from  10  to  15  days  to  dissolve,  steel 
from  8  to  10,  and  malleable  iron  4  days.  The  residuum  of  a  black  color  does  not  contain 
a  trace  of  sulphur. 

Phosphorus  and  chromium  are  determined  in  the  following  way.  The  iron  must  be 
dissolved  in  nitro-murialic  acid,  to  oxygenate  those  two  bodies.  The  solution  must  be 
evaporated  cautiously  to  dryness  in  porcelain  capsules,  and  the  saline  residuum  healed 


I. 


i\ 


IRON. 


1095 


to  redness.  A  little  chloride  of  iron  is  volatilized,  and  the  remainder  resembles  the 
red-brown  oxyde.  This  must  be  mixed  with  thrice  its  weight  of  carbonate  of  potash, 
and  fused  in  a  platinum  crucible  j  the  quantity  of  iron  being  from  40  to  50  grains  at 
most. 

The  mixture,  after  being  acted  upon  by  boiling  water,  is  to  be  left  to  settle,  to  allow 
the  oxyde  to  be  deposited,  for  it  is  so  fine  as  to  pass  through  a  filter.  If  the  iron  con- 
tained manganese,  this  would  be  found  at  first  in  the  alkaline  solution;  but  man- 
ganese spontaneously  separates  by  exposure  to  the  air.  The  alkaline  liquor  must  be 
supersaturated  with  muriatic  acid,  and  evaporated  to  drj'ness.  The  liquor  acidulated, 
and  deprived  of  its  silica  by  filtration,  is  to  be  supersaturated  with  ammonia ;  when 
the  alumina  will  precipitate  in  the  state  of  a  subphosphate.  When  the  liquor  is  now 
supersaturated  with  acetic  acid,  and  then  treated  with  acetate  of  lead,  a  precipitate 
of  phosphate  of  lead  almost  always  falls.  There  is  hardly  a  bit  of  iron  to  be  found 
which  does  not  contain  phosphorus.  The  slightest  trace  of  chrome  is  detected  by  the 
yellow  color  of  the  lead  precipitate ;  if  this  be  white  there  is  none  of  the  coloring  metal 
present. 

100  parts  of  the  precipitated  phosphate  of  lead  contain,  after  calcination,  19*4  parts  of 
phosphoric  acid.  The  precipitate  should  be  previously  washed  with  acetic  acid,  and  then 
with»»nrater.    These  19*4  parts  contain  8*525  parts  of  phosphorus. 

Cast  iron  sometimes  contains  calcium  and  barium,  which  may  be  detected  by  their 
well-known  reagents,  oxalate  of  ammonia,  and  sulphuric  acid.  In  malleable  iron  they 
are  seldom  or  never  present. 

The  charcoal  found  in  the  residuum  of  the  nitro-muriatic  solution  is  to  be  burned  away 
under  a  muffle.  The  solution  itself  contains  along  with  the  oxyde  of  iron,  protoxyde  of 
manganese,  and  other  oxydes,  as  well  as  the  earths,  and  the  phosphoric  and  arsenic  acids. 
Tartaric  acid  is  to  be  added  to  it,  till  no  precipitate  be  formed  by  supersaturation  with 
caustic  ammonia.  The  ammoniacal  liquor  must  be  treated  with  hydrosulphuret  of  ammo- 
nia as  long  as  it  is  clouded,  then  thrown  upon  a  filter.  The  precipitate  is  usually  very 
voluminous,  and  must  be  well  washed.  The  liquor  which  passes  through  is  to  be  satu- 
rated with  muriatic  acid,  to  decompose  all  the  sulphurets. 

The  solution  still  contains  all  the  earths  and  the  oxyde  of  titanium,  besides  the  phos- 
phoric acid.  It  is  to  be  evaporated  to  dryness,  whereby  the  ammonia  is  expelled,  and 
the  carbonaceous  residuum  must  be  burned  under  a  muffle.  If  the  iron  contains  much 
phosphorus,  the  ashes  are  strongly  agglutinated.  They  are  to  be  fused  as  already 
described  along  with  carbonate  of  potash,  and  the  mass  is  to  be  treated  with  boiling 
water.  The  residuum  may  be  examined  for  silica,  lime,  barytes,  and  oxyde  of  titanium. 
Muriatic  acid  being  digested  on  it,  then  evaporated  to  dryness,  and  the  residuum  treated* 
with  water,  will  leave  the  silica.  Caustic  ammonia,  poured  into  the  solution,  will  sepa- 
rate the  alumina,  if  any  be  present,  and  the  oxyde  of  titanium ;  but  the  former  almost 
never  occurs. 

Manganese  is  best  sought  for  by  a  distinct  operation.  The  iron  must  be  dissolved 
at  the  heat  of  boiling  water,  in  nitro-muriatic  acid ;  and  the  solution,  when  very 
cold,  is  to  be  treated  with  small  successive  doses  of  solution  of  carbonate  of  am- 
monia. If  the  iron  has  been  oxydized  to  a  maximum,  and  if  the  liquor  has  been 
sufficiently  acid,  and  diluted  with  water,  it  will  retain  the  whole  of  the  manganese. 
This  process  is  as  good  as  that  by  succinate  of  ammonia,  which  requires''  many 
precautions.  ' 

The  liquor  is  often  tinged  yellow  by  carbon,  after  it  has  ceased  to  contain  a  single  trace 
of  iron  oxyde.  As  soon  as  litmus  paper  begins  to  be  blued  by  carbonate  of  ammonia,  we 
should  stop  adding  it ;  immediately  throw  the  whole  upon  a  filter,  and  wash  continuously 
with  cold  water.  What  passes  through  is  to  be  neutralized  with  muriatic  acid,  and  con- 
centrated by  evaporation.  It  may  contain,  besides  manganese,  some  lime  or  barjtes.  It 
should  therefore  be  precipitated  with  hydro-sulphuret  of  ammonia,  the  hydrosulphuret  of 
manganese  should  be  collected,  dissolved  in  strong  muriatic  acid,  filtered,  and  treated,  at 
a  boiling  heat,  with  carbonate  of  potash.  The  precipitate,  weU  washed  and  calcined, 
contains,  m  100  parts,  72-75  parts  of  metallic  manganese. 

The  copper,  arsenic,  lead,  tin,  bismuth,  antimony,  or  silver,  are  best  separated  by  a 
stream  of  sulphureted  hydrogen  gas  passed  through  the  solution  in  nitro-muriatic  acid, 
after  it  is  largely  dUuted  with  water.  The  precipitate  must  be  cautioudy  roasted  in  a 
porcelain  test,  to  bum  away  the  large  quantity  of  sulphur  which  is  deposittd  in  con- 
sequence of  the  conversion  of  the  peroxyde  of  iron  into  the  protoxyde.  If  nothing 
remains  upon  the  test,  none  of  these  metals  is  present.  If  a  residuum  be  obtained,  it 
must  be  dissolved  in  nitro-muriatic  acid,  and  subjected  to  examination.  But,  in  fact, 
carbon,  sulphur,  phosphorus,  silicon,  and  manganese,  are  the  chief  contaminators  of 
iron* 

Chloride  of  silver  aflfords  the  means  of  determining  the  proportion  of  carbon  contained 
in  iron  and  of  ascertaining  the  state  in  which  that  substance  exists  in  the  metal.    Fused 


1096 


IRON. 


I 


chloride  of  a  pale  yellow  color  must  be  employed.  The  operation  is  to  be  performed 
in  c^se  vessels,  with  the  addition  of  a  great  deal  of  water,  and  a  few  drops  of  muriatic 
acid.  The  carbonaceous  residuum  is  occasionally  slightly  acted  upon.  We  may 
judge  of  this  circumstance  by  the  gases  disengaged,  as  weU  as  by  the  appearance  of  the 
charcoal. 

Ductile  iron  and  soft  steel,  as  weU  as  white  cast-iron  which  has  been  rendered  gray 
by  roasting,  when  decomposed  by  chloride  of  silver,  afford  a  blackish-brown  unmagnetic 
charcoal,  and  a  plumbaginous  substance  perfectly  similar  to  what  is  extracted  from  the 
same  kinds  of  iron,  by  solution  in  acids.  A  portion  of  this  plumbago  is  also  converted 
into  charcoal  of  a  blackish  brown  color,  by  the  action  of  the  chloride.  Hence  this 
agent  does  not  afford  the  means  of  obtaining  what  has  been  called  the  poly-carburet,  till 
it  has  produced  a  previous  decomposition.  But  we  obtain  it,  in  this  manner,  purer  and  in 
greater  quantity  than  we  could  by  dissolving  the  metal  in  the  acids.  The  only  subject 
of  regret  is,  that  we  possess  no  good  criterion  for  judging  of  the  progress  of  this  analytical 
operation. 

Gray  cast  iron  leaves,  besides  the  poly-carburet,  a  residuum  of  plumbago,  and  carbon 
which  was  not  chemically  combined  with  the  iron ;  while  tempered  steel  and  white  cast 
iron  afford  merely  a  blackish  brown  charcoal ;  but  the  operation  is  extremely  slow  with 
the  latter  two  bodies,  because  a  layer  of  charcoal  forms  upon  the  surface,  which%ob- 
strucls  their  oxydizement.  For  this  reason  the  white  cast  iron  ought  to  be  previously 
changed  into  gray  by  fusion  in  a  crucible  lined  with  charcoal,  before  being  subjected  to  the 
chloride  of  silver;  if  this  process  be  emfloyed  for  tempered  steel,  the  combined  carbon 
becomes  merely  a  poly-carburet.  It  would  not  be  possible  to  operate  upon  more  than 
15  grains,  which  require  from  60  to  80  times  that  quaniity  of  the  chloride,  and  a  period 
of  15  days  for  the  experiment. 

The  residuum,  which  is  separable  from  the  silver  only  by  mechanical  means,  should  be 
dried  a  long  time  at  the  heat  of  boUing  water.  It  contains  almost  always  iron  and  silica. 
After  its  weight  is  ascertained,  it  is  to  be  burned  in  a  crucible  of  platinum  till  the  ashes 
no  longer  change  their  color,  and  are  not  attractable  by  the  magnet.  The  difference  be- 
tween the  weights  of  the  dried  and  calcined  residuum  is  the  weight  of  the  charcoal.  The 
oxyde  of  iron  is  afterwards  separated  from  the  silica  by  muriatic  acid. 

In  operating  upon  gray  cast  iron,  we  should  ascertain  separately  the  proportion  of 
graphite  or  plumbaso,  and  that  of  the  combined  charcoal.  To  determine  the  former, 
we  dissolve  a  second  quantity  of  the  cast  iron  in  nitric  acid,  with  a  little  muriatic ;  the 
residuum,  which  is  graphite,  is  separated  from  the  silica  and  the  combined  carbon  by  the 
action  of  caustic  potash.  After  being  washed  and  dried,  it  must  be  weighed.  The  weight 
of  the  graphite  obtained  being  deducted  from  the  quantity  of  carbon  resulting  from  the  de 
composition  effected  by  the  chloride  of  silver,  the  remainder  is  the  amount  of  the  chemi 
ei^Jy  combined  carbon. 

By  employing  muriatic  acid,  we  could  dissipate  at  once  the  combined  carbon  ;  but  tK 
method  would  be  inexact,  because  the  hydrogen  disengaged  would  carry  off  a  portion  of 
the  graphite. 

According  to  Karsten,  Mushet's  table  of  the  quantities  of  carbon  contained  in  different 
steels  and  cast  irons  is  altogether  erroneous.  It  gives  no  explanation  why,  with  equal 
proportions  of  charcoal,  cast  iron  constitutes  at  one  time  a  gray,  soft,  granular  metal,  and 
at  another,  a  white,  hard,  brittle  metal  in  lamellar  facets.  The  incorrectness  of  Mushet's 
statement  becomes  most  manifest  when  we  see  the  white  lamellar  ca^t  iron  melted  in  a 
crucible  lined  with  charcoal,  take  no  increase  of  weight,  while  the  gray  cast  iron  treated 
in  the  same  way  becomes  considerably  heavier. 

Analysis  has  never  detected  a  trace  of  carbon  unaltered  or  of  graphite  in  white  cast  iron, 
if  it  did  not  proceed  from  small  quantities  of  the  gray  mixed  with  it ;  while  perfect  gray 
cast  iron  affords  always  a  much  smaller  quantity  of  carbon  altered  by  combination,  and  a 
much  greater  quantity  of  graphite.  Neither  kind  of  cast  iron,  however,  betrays  the  pres- 
ence of  any  oxygen.  Steel  affords  merely  altered  carbon,  without  graphite ;  the  same 
thing  holds  true  of  malleable  iron ;  while  the  iron  obtained  by  fusion  with  25  per  cent,  of 
scales  of  iron  contains  no  carbon  at  all. 

The  graphite  of  cast  iron  is  obtained  in  scales  of  a  metallic  aspect,  whereas  the  com- 
bined carbon  is  obtained  in  a  fine  powder.  When  the  white  cast  iron  has  been  roasted, 
and  become  gray,  and  is  as  malleable  as  the  softest  gray  cast  iron,  it  still  affords  no  gra« 
phite  as  the  latter  does,  though  in  appearance  both  are  alike.  Yet  in  their  properties 
they  are  stiU  essentially  dissimilar. 

With  4 J  per  cent,  of  carbon,  the  white  cast  iron  preserves  its  lameUar  texture ;  but 
with  less  carbon,  it  becomes  granular  and  of  a  gray  color,  growing  paler  as  the  dose 
of  carbon  is  diminished,  while  the  metal,  after  passing  through  an  indefinite  numbef 
of  gradations,  becomes  steely  cast  iron,  very  hard  steel,  soft  steel,  and  steely  wrought 
iron. 

The  steels  of  the  forge  and  the  cast  steels  examined  by  Karsten,  afforded  him  fion: 


X 


4 


IRON. 


1097 


2*'^  to  ll  per  cent,  of  carbon;  in  the  steel  of  cementation  (blistered  steel),  he  never 
found  above  If  of  carbon.  Some  wrought  irons  which  ought  to  contain  no  charcoal,  hold 
as  much  as  J  per  cent,  and'they  then  approach  to  steel  in  nature.  The  softest  and  purest 
xons  contain  still  0*2  per  cent,  of  carbon. 

The  quantity  of  graphite  which  gray  cast-iron  contains,  varies,  according  to  Karsten's 
experiments,  from  2*57  to  3*75  per  cent. ;  but  it  contains,  besides,  some  carbon  in  a  state 
of  alteration.  The  total  contents  in  carbon  varied  from  3*  15  to  4*65  per  cent.  When 
the  congelation  of  melted  iron  is  very  slow,  the  carbon  separates,  probably  in  conse- 
quence of  its  crystallizing  force,  so  as  to  form  a  gray  cast-iron  replete  with  plumbago. 
If  the  gray  do  not  contain  more  charcoal  than  the  white  from  which  it  has  been  formed, 
and  if  it  contain  the  charcoal  in  the  state  of  mechanical  mixture,  then  it  can  have  little 
or  none  in  a  state  of  combination,  even  much  less  than  what  some  steels  contain.  Hence 
we  can  account  for  some  of  its  peculiarities  in  reference  to  white  cast-iron ;  such  as  its 
granular  texture,  its  moderate  hardness,  the  length  of  time  it  requires  to  receive  anneal- 
ing colors,  the  modifications  it  experiences  by  contact  of  air  at  elevated  temperatuies,  the 
high  degree  of  heat  requisite  to  fuse  it,  its  liquidity,  and  finally  its  tendency  to  rust  by 
porosity,  much  faster  than  the  white  cast-iron. 

We  thus  see  that  carbon  may  combine  with  iron  in  several  manners ;  that  the  gray 
cast-iron  is  a  mixture  of  steely  iron  and  plumbago ;  that  the  white,  rendered  gray  and  soft 
by  roasting,  is  a  compound  of  steely  iron  and  a  carburet  of  iion,  in  which  the  carbon  pre- 
dominates ;  and  that  untempered  steel  is  in  the  same  predicament. 

For  the  following  analyses  of  cast-irons,  we  are  indebted  to  MM.  Gay  Lussac  and 
Wilson, 

Table. — ^In  100  parts. 


Cast-iron. 

Iron. 

Carbon. 

Silica. 

Phos- 
phorus. 

Manga- 
nese. 

Remarks. 

White  cast  from  Siegen 

94-338 

2-690 

0-230 

0-162 

2-590 

By  wood  charcoal. 

Do. 

Coblentz    - 

94-654 

2-441 

0-230 

0-185 

2-490 

do. 

Do. 

a.  d.  Champ 

96-133 

2-324 

0-840# 

0-703 

a  trace 

do. 

Do. 

Isere      -    - 

94-687 

2-636 

0-260 

0-280 

2-137 

do. 

Gray 

Nivemais  - 

95-673 

2-254 

1-030 

1-043 

a  trace 

do. 

Do. 

Berry    -    - 

95-573 

2-319 

1-920 

0-188 

do. 

Mixt'e  of  coke  &  do. 

Do. 

a.  d.  Champ 

95-971 

2-100 

1-060 

0-869 

do. 

Charcoal. 

Do. 

Creusot 

93-385 

2-021 

3-490 

0-604 

do. 

Coke. 

Do. 

a.  d.  Franche 

t 

Comte    - 

95-689 

2-800 

1-160 

0-351 

do. 

do. 

Do. 

Wales   -    - 

94-842 

1-666 

3-000 

0-492 

do. 

do. 

Do. 

Do.  -    -    - 

95-310 

2-550 

1-200 

0-440 

do. 

do. 

1  Do. 

Do.  -    -    - 

95-150 

2-450 

1-620 

0-780 

do. 

do. 

Karsten  has  given  the  following  results  as  to  carbon,  in  100  parts  of  gray  cast-iron. 


1 

Combined 

Free 

Total. 

Gray  cast-iron. 

carbon. 

carbon. 

carbon. 

Remarks. 

Sicgen,  from  brown  iron  stone    - 

0-89 

3-71 

4-60 

By  wood  charcoal. 

Siegen  ( Widderstein),  from  brown 

and  sparry  iron  -    -    -    -    - 

1-03 

3-62 

4-65 

do. 

1  Malapane,  from  spherosiderite    - 

0-75 

3-15 

3-90 

do. 

Konigshutte,  from  brown  ore     - 

0-58 

2-57 

3-15 

coke. 

j_po.  at  a  lower  smelting  heat  -    - 

0-95 

2-70 

3'65 

do. 

IRON,  Cast,  Strength  of. — In  the  following  Table  each  bar  is  reduced  to  exactly 
one  equiire  incli ;  and  the  transverse  strength,  which  may  be  taken  as  a  criterion  of 
the  vahie  of  each  iron,  is  obtained  from  a  mean  between  the  experiments  upon  it, 
{Memoirs  of  Brit.  Ass.)  first  on  bars  4  ft.  6  in.  between  the  supports,  and  next  on 
those  of  half  the  length,  or  2  ft.  3  in.  between  the  supports.  All  the  other  results 
are  deduced  from  the  4  ft.  6  in.  bars.  In  all  ca.ses  the  weights  were  laid  on  the  middle 
of  the  bar. 


1098 


IRON. 


Table  of  Results  obtained  from  Experiments  on  the  Strength  and  other  Properties  of 
Cast  Iron,  from  the  principal  Iron  Works  in  the  United  Kingdom.  By  Mr.  Wnu 
Fairbairn. 


1-f 


Names  of  Irons 


1 
2 
3 
4 
A 
6 
7 
8 
9 
10 
11 
I'i 
13 
14 
15 
16 
17 
18 
19 
30 
21 
22 
23 
24 
35 
36 
37 
38 
29 
30 
31 
33 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 


Ponkey,  No.  3.  Cold  Blast    -    - 
Devon,  No.  3.  Hot  Blast*     -    - 
Oldberry,  No.  3.  Hot  Blast      - 
Carron,  No.  a  Hot  Blast*   • 
Beaufort,  No.  3.  Hot  Blast  -    -    - 

Butterley 

Bute,  No.  1.  Cold  Blast  -  -  - 
Wind  Mill  End,  No.  2.  Cold  Blast 
Old  Park,  No.  2.  Cold  Blast  - 
Beaufort,  No.  3.  Hot  Blast  -  - 
Low  Moor,  No.  3.  Cold  Blast  -  - 
Buttery,  No.  1.  Cold  Blast*  -  - 
Brimbo,  No.  2.  Cold  Bl;wt  -  -  - 
Apedale,  No.  2.  Hot  Blast  -  - 
Oldberry,  No.  2.  Cold  Blast     -    - 

Pentvryn,  No.  3. 

Maesteg,  No.  3.       

Muirkirk,  No.  1.  Cold  Bla-st* 
Adelphi,  No.  2.  Cold  Blast       .    - 
Blania,  No.  3.  Cold  Blast 
DeTon,  No.  3.  Cold  Blast*  - 
Gartsberrie,  No.  3.  Hot  Blast  - 
Fruod,  No.  2.  Cold  Blast     -    ■ 

Lane  End.  No.  3. 

Carron,  No.  3.  Cold  Blast*  -  • 
Dundivan,  No.  3.  Cold  Blast  ■ 
Maesteg  (Marked  Red)  -  -  ■ 
Corbyns  Hall,  No.  2.        ... 

Pontvpool,  No.  3. 

Wallbrook,  No.  3.       .... 
Milton,  No.  3.  Hot  Blast      .    - 
Buflerj',  No.  1.  Hot  Blast* 
Level,  No.  1.  Hot  Blast  -    -    . 

Pant,  No.  2. 

Level,  No.  3.  Hot  Blast  -    -    ■ 

W.  S.  S.,  No.  3. 

Kagle  Foundry,  No.  2.  Hot  Blast 
Elsit.ar,  No.  3.  Cold  Bla.«  -  - 
Varteg,  No.  2.  Hot  Blast  -  •  • 
Coltham,  No.  1.  Hot  Blast  •  - 
Carroll,  No.  3  Cold  Blast  -  .  - 
Muirkirk,  No.  1.  Hot  Blast*    •    . 

Bierley,  No.  3. 

Coed-Talon,  No.  2.  Hot  Blast*  - 
Coed-Talon,  No.  2.  Cold  Blast* 
Monkland,  No.  3.  Hot  Blast  -  - 
Ley's  Works,  No.  1.  Hot  Blast  • 
Milton,  No.  1.  Hot  Blast  -  -  • 
Plaskyoaston,  No.  2.  Hot  Blast    - 


•c 

u 

■-  £ 

o  o 

S 

|2 
|E 

3 
SB 


It 


0) 
CO 


7-122 
7-251 
7-3<X) 
7-056 
7-061) 
7-038 
7-06f; 
7071 
7049 
7-108 
7-O.V, 
7-079 
7-017 
7-017 
7-a'>9 
7-0:W 
7-038 
7-113 

7im) 

7-1.59 
7-2«.'> 
7-017 
70:n 
7-028 
7-0!M 
"■0«7 
7-(m 
7-007 
7  0S0 
6-979 
7-051 
6-;^9« 
7-OSO 
6-975 
7-031 
7-041 
7-038 
6-;«S 
7-007 
7-1-28 
7-069 
6-9M 
7-ia5 
6-969 
6-9.55 
6-916 
6-957 
6-976 
6-916 


■HI 

2  «  t> 

JS     .e 

«  i.« 

<-  S  ^ 

m  a  O 

-a  a  a 
o  — — • 


17211000 

2247:}6.50 

2273:)400 

17873100 

16802000 

1.5.379500 

1516.3(XX) 

16490000 

14607000 

16.301000 

14509500 

1.5381200 

14911666 

148.52000 

14307.500 

15193000 

1.3959600 

140035.50 

13815,500 

14281466 

22<W770O 

13894000 

13112666 

15787666 

163469«>6 

ia534a)0 

13971,500 

13845866 

131:16500 

l,5.3'.M7(-rf> 

15852.500 

13730500 

1*4V2500 

15-280900 

1.5241000 

149.5.3333 

142U000 

12.58fi.50(J 

iriOliOOO 

1.55100W 

1703600f» 

1321M400 

161.56133 

14322.500 

14.304000 

122.59rflO 

11.539333 

11974.500 

13.3416.%3 


e 

-^  2  a;  M  9 


-  o  i 
e  e  cj 


.y  - 


-  i- 


;o5  io-cS 


567 
.537 
,543 
.520 
,505 
489 
495 
483 
441 
478 
462 
463 
466 
457 
453 
4.38 
453 
443 
441 
433 
448 
427 
460 
444 
4+4 
456 
440 
4:M 
4.39 
432 
427 
4-36 
461 
408 
419 
413 
408 
446 
422 
464 
430 
417 
404 
409 
403 
402 
392 
3.53 
373 


695 

517 
5.34 
529 
515 
487 
495 
5-29 
470 
483 

4.53 
4.55 
457 
473 
4,55 
464 
457 
464 

467 
434 

443 
4.30 
444 
454 
441 
449 
449 

403 
455 
439 
446 
446 
408 
430 
385 
408 
419 
4.32 
424 
418 
401 

386 
337 


90 

S 


"s  e 


C0  J3 

a 


•a 


.  —  y 

■3  2  2,' 


581 
5.37 
.5.30 
627 
617 
502 
491 
+S9 
485 
474 
472 
463 
4.59 
4.56 
455 


o  a 


U 


«   O  Q 

ft.  5  a 


1-747 

1-09 

1-005 

1-365 

1-599 

1-815 

1-764 

1-.581 

1-621 

1-612 

1-.S52 

1-.55 

1-748 

1-730 

1-811 


455'  1-484 


4.54 
4.53 
449 
448 
448 
447 
447 
444 
443 
443 
442 
443 
440 
440 
438 
436 
432 
431 
429 
429 
427 
4-27 
426 
424 
419 
418 
418 
416 
413 
403 
393 
369 
a57 


1-957 
1-734 
1-759 
1-726 
-790 
1-557 
1-825 
1-414 
1-336 
1-469 
1-887 
1-687 
1-857 
1-443 
1-368 
1-64 
1-.516 
1-151 
1-358 
1-339 
1-.512 
2-224 
1-4.50 
1-532 
1-331 
1-570 
1  -2i-2 
1-882 
1-470 
1-762 
1-890 
1-.525 
1-366 


Color. 


993  Whitish  gray 
.589  While     -    • 

649  White  -  • 
710  Whitish  gray 
807  Dullish  gray 
889  Dark  gray  - 
872  Bluish  gray 
765  Dark  giay  - 
718  Gray  -  -  - 
729  Dull  gray  - 
8.55  Dark  gray  . 
721  Gray  -    .    - 

815  Light  gray  - 
791  Light  gray  - 
822  Dark  gray   - 

650  Bluish  gray 
886  Dark  gray  - 
770  Bright  gray 
777  Light  gray  - 
747  Bright  gray 
7.53  Light  gray 
998  Light  gray  - 
841  j  Light  gray  - 
629  Dark  gray   - 
6931  Gray   -    -    - 
6741  Dull  gray    - 
8.30' Bluish  gray 
727iGray  -    -    . 

816  Dull  blue  - 
625!  Light  gray  - 
686  Gray        -     - 

Dull  graj-     - 
Light  gray  - 
Light  gray   . 
Dull  gray    - 
Light  gray  - 
Bluish  gray 
Gray       -    ~ 
Gray  -    -    - 
Whitish  gray 
Gray  .     .    - 
Bluish  gray 
Dark  gray  - 
Bright  gray 
Gray  -    -    - 
Bluish  gray 
Bluish  gray 
Gray   ... 
Light  gray 


721 
69i» 
611 
670 
6,54 
618 
992 
621 
716 
5-30 
656 
494 
771 
600 
709 
742 
638 
617 


Quality. 


Hard. 
Hard. 
Hud. 

Hard. 

Hard. 

Soil. 

Soft. 

Hard. 

Soft. 

Hard. 

Soft. 

Hather  hard. 

Kather  hard. 

Stiff. 

Kather  soft. 

Hard. 

Rather  soft. 

Fluid. 

Soft. 

Hard. 

Hard. 

Soft. 

Open. 

Soft. 

Soft. 

Rather  soft. 

Fluid. 

Soft. 

Rather  soft. 

Rather  hard. 

Rather  hard. 

Soft. 

Sort. 

Rather  bard. 

Soft. 

Soft. 

Soft. 

Soft. 

Hard. 

Rather  soft. 

Hard. 

Soft. 

Soft. 

Soft. 

Rather  soft. 

Soft. 

Soft. 

Soft  and  finid. 

Ratlier  soft. 


Rule. — To  find  from  the  above  table  the  breakin^^  weight  in  rectangular  bars,  gene- 
rally, calling  b  and  d  the  breadth  and  depth  in  inches,  and  /  ihe  di-*tance  between  the 


supports   in   feet,   and  putting   4-5  for   4   ft.  6  in.,   we   have 


4-5x^25 


=  breaking 


weight  in  lbs.,  the  value  of  S  being  taken  from  the  table  above. 

For  example : — What  weight  would  be  necessary  to  break  a  bar  of  Low  Moor 
iion,  2  inches  broad,  3  inches  deep,  and  6  feel  oetween  the  supports  ?    According  to 

Analyses  of  Ten  Specimens  of  Cast  Iron  made  from  South  Staffordshire  Iron  Ore,  Wegt 

of  Dudley. 


Iron  Jrom 

Hot  Blast. 

Iron 

I. 

II. 

III. 

IV. 

V. 

VI. 

89.53 

92-93 

93-84 

92-90 

C(a)95-23 

95-80 

Carbon  -    -    -    - 
Carbon  -    -    -    - 

C8-27    7-93 

C3-11    6-61 

C2-93   5-64 

C0-S7    6-88 

C(b)  1-77 
0-49 

2-72 
0-26 

Silica,  Ac  -    -    - 

.      .       - 

- 

... 

-       .       . 

0-81 

0.11 

Man^ranese  -    -    - 

1-71 

1-80 

0-72 

0-62 

0-84 

0-M 

Calcium      -    -    - 

0-11 

trace 

0.34 

0-06 

010 

0-06 

Sodium      -    -    - 

0-41 

0.37 

0.39 

0-30 

0-19 

0-14 

Potassium  -    -    - 

... 

. 

trace 

trace 

Sulphur     - 

0-07 

trace 

minute  trace 

trace 

trace 

trace 

Phosphorus    -    • 

i 
! 

0-54 

lost 

0-07 

0-40 

0-12 

0-87 

100-39 

100-19 

100  90 

101.11 

98-55 

100-00 

*  The  irons  with  asterisks  are  taken  from  the  experiments  on  hot  and  cold  blast  iron,  made  by  Mr. 
Hodgkinson  and  myself  for  the  British  Association  for  the  Advancement  of  Science.— Se^  Seventh 
Report,  voL  vL 

tThe  modulus  of  elasticity  was  nsnallv  taken  from  the  deflection  caused  bv  112  lbs.  on  the  4  ft, 
in.  bars. 


i 


I 


IRON. 

Iron  from  Cold  Blast. 


1099 


Iron-     ------ 

Combined  carbon  (a)    - 
Uncombined  carbon  (b) 

Silica 

Manganese     -     -     -    - 

Cobalt 

Chromium-    -    -    -     . 

Calcium 

Sodium 

Potassium 

Sulphur 

Phosphorus     -    -     -     . 


I. 


94-10 

1-87 

1-92 

1-30 

112 

trace 

trace 

006 

015 

trace 

trace 

0-21 


100-73 


III. 


96-57 


trace 

trace 

042 

0-11 

0-36 


101-75 


n. 

. 

V. 

94-&S 

94-42 

C  1-98  3-71 

C2-73 

4.05 

0-.33 

- 

094 
trace 

0-25 
0-30 

016 
034 

0-05 
003 

- 

trace 
0-36 

99-20 

- 

100-27 

the  rule  given  above,  we  have  6  =  2  inches,  d=3  inches,  /  =  6  feet,  5  =  472  from  the 

„„       4-5  Xbd'S       4-5  X  2  X  32  X  472 
table.     Ihen ^ = =  6372  lbs.,  the  breaking  weight 

A  very  small  amount  of  phosphorus  is  found  to  impart  to  iron  a  great  degree  of 
brittleness,  when  bar  iron  contains  but  0*5  per  cent. 

Fig.  818.  represents  in  section,  andfig.  817.  in  plan,  the  famous  cupola  furnace  for  cast- 
ing iron  employed  at  the  Royal  Foundry  in  Berlin.  It  rests  upon  a  foundation  a,  from  IB 
to  24  inches  high,  which  supports  the  basement  plate  of  cast  iron,  furnished  with  ledges, 
for  binding  the  lower  ends  of  the  upright  side  plates  or  cylinder,  e.  Near  the  mouth 
there  is  a  top-plate  d,  made  in  several  pieces,  which  serves  to  bind  the  sides  at  their 
upper  end,  as  also  to  cover  in  the  walls  of  the  shaft.  These  plates  are  most  readily  se- 
cured in  their  places  by  screws  and  bolts.  Within  this  iron  case,  at  a  little  distance 
from  it.  the  proper  furnace-shaft  c,  is  built  with  fire-bricks,  and  the  space  between  this 
and  the  iron  is  filled  up  with  ashes.  The  sole  of  the  hearth  /,  over  the  basement-plate, 
is  composed  of  a  mixture  of  fire-clay  and  quartz-sand  firmly  beat  down  to  the  thicknew 
of  6  or  8  inches,  with  a  slight  slope  towards  the  discharge-hole  for  running  off  the 
metal,  g  is  the  form  or  the  tuydre  (there  are  sometimes  one  on  each  side) ;  h  the 
nose  pipe;  the  discharge  aperture  i  is  12  inches  wide  and  15  inches  high;  acrosa 
which  the  sole  of  the  hearth  is  rammed  down.  During  the  melting  operation  this 
opening  is  filled  up  with  fire-clay  ;  when  it  is  completed,  a  small  hole  merely  is  pierced 
through  it  at  the  lowest  point,  for  running  off  the  liquid  metal.     The  hollow  shaft  should 

818 


be  somewhat  wider  at  bottom  than  at  top.  Its  dimensions  vary  with  the  magnitude  of 
the  foundry.  When  5  feet  high,  its  width  at  the  level  of  the  tuyere  or  blast  hole  may 
be  from  20  to  22  inches.  From  250  to  300  cubic  feet  of  air  per  minute  are  required 
for  tlie  working  of  such  a  cupola.  For  running  down  100  pounds  of  iron,  after  the 
furnace  has  been  brought  to  its  heat,  48  pounds  of  ordinary  coke  are  used ;  but  with  the 
hot  blast  much  less  will  suffice.  The  furnace  requires  feeding  with  alternate  charges 
of  coke  and  iron  every  8  or  10  minutes.  Tlie  waste  of  iron  by  oxidation  and  »lag 
amounts  in  most  foundries  to  fully  5  per  cent.  For  carrying  off  the  burnt  air,  a  chim- 
ney-hood is  commonly  erected  over  the  cupola.     See  Foundry. 


1100 


IRON. 


The  double  arche«l  air  or  wind-furnace  used  in  the  foundries  in  StaflFordshire  for  meltinif 
cast  iron,  has  been  found  advantageous  in  saving  fuel,  and  preventing  waste  bv  sla-r  It 
requires  fire-bricks  of  great  size  and  the  best  composition.  "       ^ 

The  main  central  key-stone  is  constructed  of  large  fire-bricks  made  on  purpose ;  ao-ainst 
that  key-stone  the  two  arches  press,  having  their  abutments  at  the  sides  against  the  walla. 
The  highest  point  of  the  roof  is  only  8  inches  above  the  melted  metal.  The  sole  of  the 
hearth  is  composed  of  a  layer  of  sand  8  inches  thick,  resting  upon  a  bed  of  iron  or  of 
brickwork.     The  edge  of  the  fire-bridge  is  only  3  inches  above  the  fluid  iron 

In  from  2  to  4  hours  from  1  to  3  tons  of  metal  raav  be  founded  iR  such  a  furnace 
according  to  its  size;  but  it  ought  always  to  be  heated'to  whiteness  before  the  iron  is 
uitroduced    100  pounds  of  cast  iron  require  from  1  to  U  cubic  foot  of  coal  to  melt  them 
Ihe  waste  varies  from  5  to  9  per  cent, 

I  shall  conclude  the  subject  of  iron  with  a  few  miscellaneous  observations  and  statist!- 
cal  tables.  Previously  to  the  discovery  by  Mr.  Cort,  in  1785,  of  the  methods  of  puddling 
and  rolhng  or  shingling  iron,  this  country  imported  70,000  tons  of  this  metal  from 
Kussia  and  Sweden ;  an  enormous  quantity  for  the  time,  if  we  consider  that  the  cotton 
and  other  automatic  manufactures,  which  now  consume  so  vast  a  quantity  of  iron  were 
then  m  their  infancy.  From  the  following  table  of  tlie  prices  of  bar  iron  in  succe*. 
«ive  years,  we  may  infer  the  successive  rates  of  improvement  and  economy,  with  slight 


Years. 

Per  Ton. 

£  9.    £ 

8. 

1824 

9  0  to  10 

0 

1825 

10  0—14 

0 

1826 

8  10  —  10 

0 

1827 

8  0    9 

0 

1828 

8  10—  8 

0 

1829 

6  10—  7 

0 

Years. 


1830 
1831 
1832 
1833 
1834 
1835 


Per  Ton. 


£  «.        £  «. 

5  5  to    6  0 

6  5  —  6  10 
5  0  —  6  10 

5  10  —  6  0 

6  0  —  6  10 
5  10  —  7  0 


The  export  of  iron  m  1836,  in  bars,  rods,  pigs,  castings,  wire,  anchors,  hoops,  nails  and 
old  iron  amounted  to  189,390  tons ;  in  unwrought  steel  to  3,014,  and  in  cutlery  to  21  072  • 
in  whole  to  213,478;  leaving  apparently  for  internal  consumption  776,522  tons, 'from' 
which  however  one-tenth  should  probably  be  deducted  for  waste,  in  the  conversion  of  the 
bar  iron.  Hence  700  000  tons  may  be  taken  as  the  approximate  quantity  of  iron  made 
use  of  m  the  United  Kingdom,  in  the  year  1836.  ^  J 

The  years  1835  and  1836  being  those  of  the  raUway  mania  over  the  world  produced 
ft  considerable  temporary  rise  in  the  price  of  bar  iron ;  but  as  this  increased  demand 
caused  the  construction  of  a  great  many  more  smelting  and  refining  furnaces,  it  has  tended 
eventually  to  lower  the  prices;  an  eflfect  also  to  be  ascribed  to  the  more  general  use  of 
the  hot  blast.  ^ 

The  exports  of  foreign  produce  in  1850  amounted  to  5,996  tons,  in  1851  to  4  818 

^nlf^J  .-^"^"^I",  P^^V''^  f  """  ^'""^^  (^'^^^P^  ^*^^^)  ^"  1S50'  772,830  tons,  in   1861 
908,955  tons;  the  declared  value  being  respectively  4,956,308^.  and  5  4141oi;      The 

imports  in  bars  unwrought  amounted  in  1850  to  34,066  tons,  and  in  185l'to  4o"''>79 

The  relative  cost  of  making  cast  iron  at  Merthyr  Tydvil  in  South  Wale^  and  at 

Glasgow,  was  as  follows,  eight  or  nine  years  ago. 

At  Merthyr. 

^  »  Tons.  Cvts.    Qrs. 

Raw  mine  at  10  per  ton,        3        7        0- 

Coal  at  6  2       16         0         - 

Limestone  15        2- 

Other  charges         -  -  .  .  .  .  ". 


Total  Cost 


«. 


d. 

6 
5 
3 


Raw  mine  at  4 
Splint  coal  at  2 
Limestone  at  0 
Coals   for   the   engine 
Other  charges 

Total  Coet 


At  Glasgow. 
Tons.    Cwts. 
3         10 
5         16 

0  14 

1  10 


£ 

«. 

d 

-  1 

13 

6 

-  0 

16 

6 

-  0 

1 

4 

-  0 

9 

1 

-  S 

0 

6 

£ 

«. 

d. 

-  0 

16 

3 

-  0 

14 

0 

-  0 

3 

6 

-  0 

3 

0 

-  1 

1 

0 

2    17     9 


IRON. 


1101 


L 


1 


The  cost  is  still  nearly  the  same  at  Merthyr,  but  it  has  been  greatly  decreased  at 
Glasgow. 

The  saving  of  fuel  by  the  hot-blast  is  said  to  be  in  fact  so  great,  that  blowing 
cylinders,  which  were  adequate  merely  to  work  three  furnaces  at  the  first  period,  were 
competent  to  work  four  furnaces  at  the  last  period,  llie  saving  of  materials  has  more- 
over been  accompanied  by  an  increase  of  one-fourth  in  the  quantity  of  iron,  in  the  same 
time  ;  as  a  furnace  which  turned  out  only  60  tons  a  week  with  the  cold  blast  now  turn:* 
out  no  less  than  80  tons.  Tliat  the  iron  so  made  is  no  worse,  but  probably  better,  when 
jiKlicioualy  smelted,  would  appear  from  the  following  statement.  A  considerable  order 
was  not  long  since  given  to  four  iron-work  companies  in  England,  to  supply  pipes  to 
one  of  the  London  water  companies.  Three  of  these  supplied  pipes  made  from  the 
cold-blast  iron ;  the  fo.urth,  it  is  said,  supplied  pipes  made  with  the  hot-blast  iron.  On 
subjecting  these  several  sets  of  pipes  to  the  requisite  trials  by  hydraulic  pressure,  the 
last  lot  was  found  to  stand  the  proof  far  better  than  any  of  the  former  three. — That 
iron  was  made  with  raw  coal. 

I  have  been  since  told  by  eminent  iron-masters  of  Merthyr,  that  this  statement  stands 
in  need  of  confirmation,  or  it  is  probably  altogether  apocryphal,  and  that  as  they  find 
the  hot  blast  weakens  the  iron,  they  will  not  adopt  it. 

Between  the  cast  irons  made  in  different  parts  of  Great  Britain,  there  are  character- 
istic differences.  The  Stafibrdshire  metal  runs  remarkably  fluid,  and  makes  fine  sharp 
castings.  The  Welsh  is  strong,  less  fluent,  but  produces  bar  iron  of  superior  quality. 
The  Derbyshire  iron  also  forms  excellent  castings,  and  may  be  worked  with  care  into 
very  good  bar  iron.  The  Scotch  iron  is  very  valuable  for  casting  into  hollow  ware-*,  as 
it  affords  a  beautiful  smooth  skin  from  the  moulds,  so  remarkable  in  the  castings  of  the 
Carron  company,  in  Stirlingshire,  and  of  the  Phcenix  foundry,  at  Glasgow.  The  Shrop- 
shire iron  resembles  the  Staffordsliire  in  its  good  qualities. 

The  average  quantity  of  fine  metal  obtainable  from  the  forge-pigs  at  Merthyr  Tydvil, 
from  the  finery  furnace,  is  one  ton  for  22  J  cwt.  of  cast  iron,  with  a  consumption  of  about 
9  J  cwt.  of  coal  per  ton. 

Estimate  of  ihe  average  cost  of  erecting  three  blastfurnaces. 

BUILDING  £XP£N'SES. 

Foundations          -            -            -            --            -            -            •            •  £480 

Masonry  of  hewn  grit-stones        -...-.-  600 

Common  bricklayers'  work           .....--  1200 

Lining  of  the  furnace,  hearth,  &c.,  in  fire-bricks  -             -             -             -             -  1140 

Fire-clay  for  building       -.--....  80 

Lime  and  sand     --....^..  800 

CAST  IRON. 

Cast-iron  pieces,  such  as  dam-plates,  tymp-plates,  beams,  tuyere-plates,  Ac., 
weighing  about  24  tons  for  each  furnace; — in  whole    -  -  -  -        1140 

WROUGHT  IRON. 

For  the  binding-hoops,  keys,  <fec. ;  5  tons  for  each  -  -  -  -  800 

COST  OK  LABOUR. 

Bricklayers,  masons,  and  labourers  in  building   •  -  •  -  -        1080 

VARIOUS  EXPENSES. 

Scaffolding  --......-48 

Tools       ..........  160 

Shed  in  front  of  each  furnace      .....--  480 

Terracing,  cost  of  ground,  «fec.      ------  -        2400 

Total  cost  of  erecting  the  furnaces       ------        9908 

INCIDENTAL  CHARGES. 

Blowing  machinery,  and  steam  engine  of  80-horse  power  ...         6400 

Inclined  railway  for  mounting  the  charges  -  -  -  •  -  120 

Gallery  for  charging         -  .  -  .  -  -  -  -160 

Steam  engine  house         ........         400 

Carried  forward         -  16.988 


1102 


IRON. 


Cliimneys,  boilers,  <fec. 
Roasting  kilns     -  -  - 

Coke  kilns  ... 

Dwelling  houses  for  workmen     - 

Total  cost  of  8  furnaces  complete 


Brought  forward 


£  16,988 
480 
480 
800 
800 

£19,548 


Estimate  from  the  Neath- Abbey  Works  in  S.  Wales,  of  the  cost  of  machines  requisite  for 
a  forge  and  shingling  mill,  capable  of  turning  out  120  tons  of  bar  iron  per  week. 

1.  Steam-engine  upon  Bolton  and  Watt's  construction  ;  of  40  inches  diameter 

in  the  cylinder,  and  8-feet  stroke ;  with  boilers,  pipes,  grate,  bars,  fire- 
doors,  <fec.  <fec.,  complete       .----..      £1,600 

2.  System  of  great-geering  for  transmitting  the  crank-motion  of  the  engine  to 

the  mill-work,  with  fly-wheel,  <fec.  -            -            -            -            -            -  1,090 

8.  A  system  of  roughing  rolls,  with  pinions,  uprights,  and  every  thing  else 

necessary    --------.  525 

4.  Two  pairs  of  finisher  rolls,  with  all  their  accessories              ...  525 

6.  Two  pairs  of  shear-machines,  at  170/.  a-piece            ....  840 

6.  One  pair  of  rolls  of  10  inches  diameter,  for  making   small  bar  iron,  with  all 

their  accessories    -..---..  280 
*7.  Forge  hammer,  including  the  anvil,  the  cam-shafts,  and  all  the  other  re- 
quisites      ---..--..  135 
8.  A  complete  turning  lathe      --.--..  2OO 


9.  To  the  above  must  be  added,  spare  cylinders  weighing  about  60  tons 

10.  Duplicate  articles  for  the  steam-engine  ..... 

11.  150  tons  of  cast-iron  plates,  to  cover  the  floor  of  the  mill     - 

12.  Eight  tons  of  cast-iron  pieces  for  a  reverberatory  furnace    -  -  - 

1 3.  Tools  of  malleable  iron ;  rakes,  oars,  <fec.       - 

14.  Castings  for  mounting  a  cupola  furnace         ..... 

15.  Blowing  machine  for  the  cupola         ...... 

16.  Pieces  of  iron  for  a  email  forge,  with  two  fires,  two  bellows,  two  anvils, 
iron  tools  faced  with  steel,  and  common  iron  tools,  <fec. 

Eight  tons  of  cast-iron  pieces,  and  wrought  iron  pieces  for  14  puddling 
furnaces      -----.... 

Seven  tons  of  cast-iron  pieces,  and  wrought-iron  for  4  re-heating  furnaces 
Tools  for  the  puddlers  and  other  workmen    -  -  -  .  . 

Iron  mountings  for  two  cranes,  partly  made  of  wood 

Total  cost  of  machines,  and  pieces  of  iron       ..... 


17 

18 
19 

20, 


£4,695 

960 

f 

900 

62 

28 

60 

80 

100 

983 

252 

15 

50 

8165 


To  the  above,  the  cost  of  the  steam  engine  house  is  to  be  added,  that  of  another  forge 
hammer,  and  incidental  expenses. 

In  Staffordshire  the  followmg  estimate  has  been  given : 

A  steam-engine  of  60-horse  power  -----. 

Rolls,  with  the  iron-work  of  the  furnaces,  Ac,  to  make  120  tons  of  bar  iron 

weekly       ---.-.... 


2016 
2672 
4588 


The  Neath- Abbey  estimate  is  greater,  but  that  company  has  a  high  character  for 
making  substantial  well-finished  machinery. 

Bar  iron  made  entirely  from  ore  without  admixture  of  cinder,  or  vitrified  oxide,  ia 
always  reckoned  worth  10».  a  ton  more  than  the  average  iron  in  the  market,  which  is 
frequently  made  by  smelting  25  per  cent,  of  cinder  with  75  of  ore  or  miru,  as  it  is  called. 

M.  Virlefs  Statistical  Table  of  the  Produce  of  Iron  in  Europe. 

QnintAls. 

England  (1827) 7,098,000 

France  (1834)  -  -  -  -  .  .  .  2,200,000 

Russia  (1834)  ----..  -1,150,000 

Austria  (1829)  ----...      850,000 

Sweden  (1825)  --.-...     850,000 

Prusoia  ----...     800,000 


IRON. 


1103 


Tlie  Hartz  Mountains 

Holland  and  Belgium 

Elba  and  Italy 

I'icdmont 

Spain     - 

Norway 

Denmark 

Bavaria 

Saxonv 

Poland 

Switzerland 

Savoy 

Total 


-  600,000 

-  600,000 

-  280,000 

-  200,000 

-  180,000 

-  150,000 
.  135,000 

-  130,000 

-  80,000 

-  .75,000 
.  30,000 

25,000 

13,438,000  (equal  to 
about  672,000  tons.) 


The  ffross  annual  production  of  iron  in  Great  Britain  is  now  upwards  of  2,250,000 
tons     Of  this  quantity  South  Wales  furnishes  700,000,  South  Staffordshire,  mcludmg 
Worcestershire,  600,000,  and  Scotland  600,000  tons.    The  remainder  is  divided  amon^ 
the  several  smaller  districts.     One  of  the  principal  causes  of  the  advantages  possessed 
by  Great  Britain  in  the  manufacture  of  iron  arises  from  the  number  and  variety  of  the 
nieasures  of  argillaceous  and  black  band  ironstones  which  alternate  with  the  beds  of 
coal  in  almost  all  the  coal  fields ;  and  in  consequence  of  which,  the  same  localities  and 
in  many  instances  the  same  mineral  workings,  frequently  furnish  both  the  ore  and  the 
fuel  to  smelt  it.     So  extensive  are  the  ironstone  beds  of  the  coal  measures  that  they 
furnish  in  themselves  the  greater  part  of  the  iron  produced  in  Great  Britain  ;  but  the 
iron-making  resources  of  the  kingdom  are  by  no  means  confined  to  them.     The  carbo- 
niferous or  mountain  limestones  of  Lancashire,  Cumberland,  Durham,  the   Forest   of 
Dean  Derbyshire,  Somersetshire  and  South  Wales,  all  furnish  important  beds  and  veins 
of  hematite ;  those  of  Ulverstone,  Whitehaven  and  the  Forest  of  Dean,  are  the  most 
extensively  worked,  and  seem  to  be  almost  exhaustless.      The  brown  hzematites  and 
white  carbonates  of  Alston  Moor  and  Weardale  also  exist  in  such  large  masses,  that 
they  must  ultimately  become  of  vast  importance.     In  the  older  rocks  of  Devon  and 
Cornwall  are  found  important  veins  of  black  haematite,  and  in  the  granite  of  Dartmoor 
numerous  veins  of  magnetic  oxide  and  specular   iron  ore.      The  new  red  sandstone 
furnishes  in  its  lowest  measures  beds   of  haematitic   conglomerate.     In   the   lias    and 
oolites  are  important  beds  of  argillaceous  ironstones,  now  becoming  extensively  worked ; 
and  the  iron  ores  of  the  green  sand  of  Sussex,  once  the  seat  of  a  considerable  manu- 
facture of  iron,  will  in  all  probability  soon  again  become  available  by  means  of  the 
facilities  of  railway  communication.  .  1.  j-  x  •  ^  • 

In  the  following  classification  the  number  of  the  blast  furnaces  in  each  district  is 
given,  and  the  ironstone  of  the  coal  measures  are  arranged  in  the  definite  order  m 
which  they  occur  in  the  different  coal  fields ;  so  that  their  position  in  reference  to  the 
beds  of  coal  alternating  with  them  is  at  once  seen.  The  more  important  of  the  coal 
fields  are  also  subdivided  into  districts  showing  the  changes  which  occur  in  each,  and 
thus  giving  a  concise  view  of -their  general  character. 

The  produce  of  the  iron  manufacture  in  Great  Britaui  in  1750  was  only  about 
80.000  tons;  in  1800  it  had  increased  to  180,000  tons;  in  1825  to  600,000  tons.  See 
Metallic  Statistics. 


Principal  Works : — 

Cwm  Bran 

Pontypool 

Abersychan 

Pentwyn 

Vateg 

Gelynos  - 

Blaenavon 


IRON,  PRODUCTION  OF. 

South  Wales.     (Eastern  Outcrop.) 


Blast  Furnaces. 

In. 

Out. 

0 

1 

2 

1 

2 

4 

0 

3 

2 

0 

8 

0 

3 

2 

23  Furnaces 


12      11 


1104 


IRON. 


IRON. 


1105 


South  Wales.    (North  Eastern  Outcrop.) 


Principal  Works : — 
Clydach 
Nant-y-glo 
Coalbrook  Vale 
BlaiDa     - 
Cwm  Celyn 
Beaufort 
Ebbw  Vale 
Victoria  - 
Sirbowey 
Tredegar 


Blast  Furnaces. 

In. 

Out 

4 

0 

7 

1 

2 

3 

2 

1 

2 

1 

7 

0 

4 

0 

2 

2 

6 

0 

7 

0 

South  "Wales.    {Southern  Outcrop) 

Principal  Worts: — 

Pentyrch  ..... 

Toudu     ..---. 
Cefn  Cu8C  ..... 

Cefn  Cribbur       ..... 
Dinas      ------ 

11  Furnaces     -  -  -  -  -     7         4 

The  iron  ore  principally  used  at  the  Pentyrch  works  is  haematite,  from  the  carbo- 
niferous limestone  on  the  south  of  the  South  Welsh  coal-field.  The  annual  productioa 
of  iron  on  the  south  outcrop  is  about  25,000  tons. 


Blast  Faraaoea. 

In. 

Out 

2 

0 

1 

1 

1 

2 

0 

1 

S 

0 

50  Furnaces 


North  Wales. 


-  42 


8 


The  beds  of  coal  in  this  division  of  the  coal-field  are  all  bituminous.  The  principal 
coals  only  are  given  in  this  section.  The  iron  stones  are  principally  argillaceous, 
although  some  important  beds  of  blackband  or  carbonaceous  ironstone  exist  locally. 
The  total  thickness  of  the  coal  measures,  in  this  series,  from  the  Soap  Vein  Mine  to  the 
bottom  coal,  is  about  150  yards. 

South  WiiLEa     {Northern  Outcrop.) 

Principal  Works : — 

Rhymney  -  .         .  - 

Dowlais  -  .  .  .  - 

Ivor         -  .  -  ,  . 

Penydarren  .... 
Cytharfa-  -  .  •.  . 

Hirwain  ..... 
Duifryn  and  Fximace  Ycha 
Ynysfach  .... 

Aberdare  .  -  .  - 

Aberammon  .... 
Gadlys    -  .  -  -  . 

70  Furnaces      ... 

South  Wali*.    {Central  Anticlinal  District.) 

Principal  Works: — 

Cwm  Avon  .... 

Oakwood  .... 

Garth  ..... 
Maesteg  ..... 
Llynvi     -  -  -  .  . 

Neath  Abbey      .... 


Blast  Famncee. 

In.       Out 

-     8         2 

-  11         3 

-     3         1 

-    6        2 

-     6        1 

-    4        0 

-    8        0 

-    4        0 

-    6        0 

-    2        1 

-    3        0 

- 

-  60       10 

Distr 

ict.) 

Blast  Furnaces. 

In.      Out 

-    4        2 

-     2        0 

-    0        8 

-    0        3 

-    4        0 

-    0        2 

20  Furnaces 


-  10       10 


South  Wales.     (  Western  or  Anthracite  District.) 


Principal  Works: — 

Venalt     - 
Ystalyfera 
Yniscedwin 
Banwen   - 
Onlluyn  or  Brin   - 
Cwm  Ammon 
Trim  Saren 
Gwendrarth 
Bran ere   - 

S4  Furnaces 


last 

Fumacea. 

In. 

Out 

0 

2 

5 

6 

3 

4 

0 

2 

2 

0 

2 

0 

0 

3 

0 

3 

0 

2 

I 


Principal  Works : — 

Rhuabon  - 
Brymbo    - 


6  Furnaces 


Shropshibb. 


' 


Principal  Works : — 

Madeley  Wood 
Madeley  Court 
The  Castle 
Light  Moor 
Horse- hay 
Lawley    - 
Hinkshay 
Stirchley 
Dark  Lane 
New  Lodge 
Donnington 
Sneds  Hill 
Langley  - 
Ketley    - 


83  Furnaces 


148  Furnaces 


Principal  Works : — 
Silverdale 
Apedale  - 
Kidsgrove 
Goldendale 
Etruria  - 
Longton  . 


South  Staffordshire. 


North  Staffordshire. 


21  Furnaces 


Yorkshire.    {Northern  District.) 


Bowling 
Low  Moor 
New  Begin 
Shelfe      - 
Bierley    - 
Farnley  - 


12 


oo 


16  Furnaces 


Blast  Furnaces. 
In.        Out 

2  1 
1         1 

3  2 


Blast  Furnaces. 

In. 

Out 

-     3 

0 

.     2 

1 

-     1 

1 

-     2 

0 

-     2 

1 

-     1 

0 

.     0 

2 

-    4 

0 

-     0 

2 

-     1 

1 

-     3 

0 

-     2 

0 

-     1 

1 

-     1 

1 

- 

-  23 

10 

Blast  FumaceSb 

In. 

Out 

105 

43 

Blast  Furnaces. 

In. 

Out 

•     1 

4 

-     2 

2 

-     3 

0 

-     2 

1 

-     3 

0 

-     2 

1 

-  13 


8 


Blast  Furnaces. 

In. 

Out 

3 

2 

1 

2 

o 

0 

0 

1 

3 

1 

1 

0 

70 


10 


1106 


IRON. 


Annual  production  of  iron  about  25,000  tons.  The  quality  of  iron  made  is  very 
•uperior.  The  Low  Moor  and  Bowling  marks  are  especially  celebrated.  The  beds  of 
coal  m  this  district  are  exceedingly  thin.  The  Better  Bed  coal  is  the  only  one  used  for 
iron  making  purposes.  The  White  Bed  and  Black  Bed  mines  of  this  district  prob.iblv 
correspond  with  the  Thorncliffe  White  mine  and  the  Clay  Wood  mine  of  the  southed 
division  of  this  field. 


Yorkshire.    {Southern  District) 


Principal  Works : — 

Worsbro'  Dale 

Elsecar    - 

Milton 

Thorncliffe 

Chapeltown 

Holmes    - 

Parkgate 


Blast  Furnaces. 

In. 

Out 

•     0 

1 

-     0 

3 

1 

1 

1 

1 

0 

13  Furnaces 


8 


Annual  production  of  iron  about  20,000  tons,  Thickness  of  measures  from  the 
Hobbimer  to  Mirtomley  beds  of  coal  about  430  yards.  The  entire  thickness  of  the 
coal  aeries  is  however  much  more.     The  measures  thin  out  rapidly  towards  the  north. 


D£RBTSHIR£. 


Principal  Works : — 
Unston    - 
Remshaw 
Staveley  - 
Duckmanton 
Birmington  Moor 
Newbold 
Winger  worth 
Clay  Cross 
Morley  Park 
Alfreton  - 
Butterley 
Codnor  Park 
West  Hallam      - 
Stanton    - 

29  Furnaces 


Blast  Furnaces. 

In. 

OuL 

•     1 

0 

•     1 

1 

.     2 

2 

0 

1 

1 

0 

1 

0 

1 

1 

1 

1 

2 

0 

2 

1 

2 

1 

2 

0 

1 

1 

2 

1 

19      10 


Annual  production  of  iron  about  60,000  tons  ;  average  thickness  of  coal  measures 
from  magnesian  limestone  to  Kilburne  or  lowest  worked  coal,  600  yards.  Many  of  the 
beds  of  ironstone  lie  in  such  a  thickness  of  measure  as  only  to  be  workable  to  advantage 
by  open  work  or  bell  pits.  Where  these  means  of  working  can  be  adopted  the  produce 
per  acre  is  oftentimes  very  large ;  in  the  Honeycroft  Rake  it  is  6,000  tons  per  acre  • 
m  the  black  shale  8,000  tons.  ' 

NORTIICMBERLAND,  CUMBERLAND,  AND  DuRHAM. 

Principal  Works; — 

Walker 

Tyne  ---... 
Wvlara  ----.. 
Hareshaw  -  -  -  -  . 

Redesdale  -  -  -  .  . 

Birtley  ----.. 
Witton  Park        -  -  -  -  - 

Taw  Law  -  -  .  .  . 

Consett  and  Crookhead    -  -  .  - 

Stanhope  -  -  -  .  . 


Blast  Furnaces. 

In. 

Out. 

•     2 

0 

■     2 

0 

1 

0 

0 

8 

0 

8 

1 

2 

3 

1 

2 

3 

7 

7 

1 

0 

38  Furnaces 


-  19       19 


IRON. 


1107 


Annual  production  of  iron  about  90,000  tons.  The  iron  works  of  this  district  are 
gradually  increasing  in  importance,  tlie  cost  of  fuel  being  so  low  as  to  permit  ores  to  be 
brought  from  many  different  localities.  The  bands  of  Scotland  and  of  Haydon  Bridge, 
the  brown  haematites  and  white  carbonates  of  Alston  and  Weardale,  and  the  argillaceous 
ironstones  of  the  lias  of  Whitby  and  Middlesborough,  are  all  used  for  the  supply  of  the  iron 
works  of  this  district. 

The  brown  htematites  deserve  especial  attention.  They  are  found  asj^ociated  in  very 
large  masses  with  the  lead  veins  of  this  district,  and  occasionally  they  occur  as  distinct 
and  regular  bed*.  They  contain  from  20  to  40  per  cent,  of  iron.  Sometimes  they  exist 
as  •'  riders"  to  the  vein,  sometimes  they  form  its  entire  mass,  and  in  this  case  they  occa- 
sionally attain  a  thickness  of  20,  30,  and  even  50  yards.  Their  employment  for  iron 
making  purposes  is  only  recent,  but  the  supply  of  ore  which  they  can  furnish  is  almost 
unlimited,  and  when  some  better  means  of  separating  the  zinc  and  lead  associated  with 
them  shall  have  been  discovered,  they  will  doubtless  be  found  to  be  of  great  importance 
Remarkable  changes  sometimes  occur  in  the  character  of  the  metalliferous  veins  of  thi» 
district;  the  same  vein  which  at  one  point  bears  principally  lead-ore  changing  to  a  cala- 
mine vein,  and  then  again  to  brown  hjematites. 


Lancashire  and  West  Cumberland. 


Principal  Works : — 

Cleator  Iron  Company 


3  Furnaces. 


Blast  Furnaces. 
In.  Out. 

8    0 


The  production  of  iron  in  this  district  is  very  limited,  being  confined  to  the  Cleator 
works  and  one  or  two  small  charcoal  works  in  the  Ulverstone  district.  The  quality  of 
the  latter,  charcoal  being  used  for  fuel,  is  very  superior,  and  the  produce  commands  the 
highest  prices,  as  it  combines  with  the  fluidity  of  cast-iron  a  certain  malleabilitv, 
especially  after  careful  annealing.  The  iron  of  the  Cleator  works  is  smelted  with  c«)al. 
and  though  in  consequence  not  equal  to  the  other,  is  yet  superior  in  quality.  The  ore 
both  of  the  Whitehaven  and  the  Ulverstone  and  Furness  districts  is  raised  most  exten- 
sively for  shipment  to  the  iron  works  of  Yorkshire,  Staffordshire,  and  North  and  South 
Wales.  In  quality  these  ores  may  be  considered  as  the  finest  in  this  kingdom,  and  the 
supplies  which  these  districts  are  calculated  to  produce  are  very  great.  The  large  per- 
centage of  iron  which  they  contain,  from  60  to  65  per  cent.,  and  their  superior  qualitv, 
also  enable  them  to  bear  the  cost  of  transport,  and  they  are  becoming  every  tiav  vf 
greater  importance.  They  are  found  both  as  beds  traversing  the  beds  of  mountain  fime- 
stone  formation  transversely  to  the  lines  of  stratification,  and  also  as  beds  more  or  le.-'s 
regular.  The  former  is  the  general  character  of  the  Ulverstone  and  Furness  ores,  no 
clearly  defined  bed  being  as  yet  known  in  that  district,  whilst  at  Whitehaven  there 
are  two,  if  not  more,  beds  of  irregular  thickness,  but  with  clearly  defined  floors  and 
roofs,  and  oftentimes  subdivided  by  regular  partings.  These  beds  attain  a  considera- 
ble thickness,  occasionally  20  or  30  feet.  The  area  over  which  they  extend  is  not 
as  yet  well  known ;  but  they  have  been  worked  extensively  for  many  years,  and  the 
workings  upon  them  are  rapidly  increasing.  They  lie  beneath  and  close  to  the  coal 
measures,  which  both  furnishes  the  necessary  fuel,  and  also  important  beds  of  argil- 
laceous ironstones  for  admixture. 


Forest  of  Deak. 


Principal  Works : — 

Cinderford 

Forest  of  Dean  Company 


6  Furnaces 


Blast  Furnaces. 
In.  Out. 

2  0 

3  0 

5    0 


Annual  production  of  iron  about  30,000  tons.  The  ores  of  the  Forest  of  Dean  are 
carboniferous,  or  mountain  limestone  ores  lying  beneath  the  coal  measures,  which  are 
not  here  productive  la  argillaceous  ironstones,  as  in  other  principal  coal  fields  of  the 
kingdom.  Besides  the  limestone  ore  there  is  a  bed  in  the  millstone  grit  measures ;  but 
which  IS  only  worked  very  locally.  Tlie  limestone  ore  occupies  a  regular  position  in 
the  limestone  measures,  although  in  itself  exceedingly  irregular,  assuming  rather  the 
character  of  a  series  of  chambers  than  a  regular  bed.  These  chambers  are  sometimes 
of  great  extent  and  contain  many  thousand  tons  of  ore,  which  is  generally  raised  at  an 
exceedingly  low  cost,  no  timbering  or  other  supports  for  the  roof  being  required.  The 
supply  of  ore  producible  in  the  Forest  of  Dean  is  almost  unlimited.  The  iron  made 
from  It  is  of  a  red  short  nature,  and  especially  celebrated  for  the  manufacture  of  tin 


1108 


IRON. 


plates.  Its  superior  quality  always  commands  a  high  price.  This  ore  is  raised  exten- 
sively for  shipment  to  the  iron  works  of  South  Wales.  It  was  worked  at  a  very  ancient 
date,  either  by  the  Romans  or  the  Britons,  as  is  evident  from  the  remains  of  old  workings 
along  the  outcrop  of  the  ore  bed.     This  ore  averages  from  30  to  40  per  cent 

For  certain  new  processes  for  making  malleable  iron,  Mr.  W.  N.  Clay  has  obtained  two 
successive  patents.  Under  the  first,  of  December,  1837,  he  mixed  bruised  haematite  with 
one-fifth  of  its  weight  of  clean  carbonaceous  matter  in  coarse  powder,  and  subjected  the 
mixture  in  a  Q  shaped  retort  to  a  bright  red  heat  for  twelve  or  more  hours,  till  the  ore 
be  reduced  to  the  metallic  state,  as  is  easily  ascertained  by  applying  a  file  to  one  of  the 
fragments.  When  discharged,  the  metal  is  to  be  transferred  mto  a  balling  or  puddling 
furnace,  along  with  about  five  per  cent,  of  ground  coke  or  anthracite,  and  worked  therein 
in  the  usual  way.  He  also  proposes  to  use  a  conical  kiln,  like  that  for  burning  lime, 
instead  of  the  retorts. 

In  his  second  patent,  dated  March,  1840,  Mr.  Clay  prescribes  above  28  per  cent  (from 
30  to  40)  of  carbonaceous  matter  to  be  mixed  with  the  ground-iron  ore,  contai«iug 
at  least  45  per  cent,  of  metal,  which  mixture  is  to  be  directly  treated  in  a  puddling 
furnace.  He  also  proposes  to  use  a  mixture  of  pig  or  scrap  iron  and  ore,  in  equ^ 
quantities. 

ITie  application  of  the  waste  gases  (carbonic  oxide  chiefly)  of  the  blast  furnace  t<r  the 
purpose  of  heating  the  puddling  or  balling  furnace,  was  made  the  subject  of  a  patent  in 
June,  1841,  by  a  foreigner  not  named.  The  process  had  been  previously  practised  in 
Germany,  and  was  fully  described  in  the  Annates  des  Mines  some  years  ago. 

In  Jig.  819.  the  manner  of  conveying  the  waste  carbonic  oxide  from  a  blast  furnace  is 
shown,     a,  a,  a,  are  openings  leading  into  the  vertical  channels  or  passages  b,  and  from 

thence  into  the  chamber  c.  There  is  a  top  to  this 
chamber,  with  openings  corresponding  to  the  pas- 
sages h.  These  openings  are  closed  with  cast-iron 
plates  that  can  be  taken  off  for  the  purpose  of 
clearing  out  the  passages  6,  and  the  chamber  c. 
From  the  chamber  c,  the  gas  may  be  conducted  in 
any  "direction,  and  to  a  distance  of  several  hundred 
feet. 

In  some  localities,  and  in  cases  where  it  is 
required  to  take  the  gas  from  a  blast  furnace  in 
operation,  a  metal  cylinder,  of  a  smaller  diameter 
than  the  top  of  the  furnace,  and  of  a  depth  equal  to 
its  diameter,  is  suspended  vertically  within  the  top 
of  the  blast  furnace  the  whole  of  its  length.  The 
space  between  the  cylinder  and  the  furnace  at  the 
top  or  mouth  is  to  be  hermetically  sealed,  and  the 
furnace  is  to  be  charged  through  the  cylinder  which 
must  be  kept  full  of  minerals  and  combustibles. 
Thus  the  space  between  the  cylinder  and  tlie 
interior  of  the  furnace  remains  vacant,  but  the 
gas  may  be  conducted  out  of  that  part  laterally, 
if  required.  The  gases  led  off  from  the  blast 
furnace  may,  if  need  be,  pass  through  heated 
pipes,  as  for  the  hot  blast. 
Figs.  820.  and  821.  represent  a  refining  furnace  for  iron,  with  the  necessary  apparatus 
for  working  it  with  the  gases,  without  the  use  of  other  fuel ;  Jig.  75.  being  a  vertical 
section,  and  Jig.  821.  a  sectional  plan  view. 

820 


The  gas  from  the  blast  furnace  is  brought  into  the  chamber  a  a,  and,  passing  through 
an  opening  6  b,  it  enters  the  furnace,  c  c  are  a  series  of  blow  pipes,  through  which  the 
heated  air  is  forced  into  the  furnace.  In  tlie  space  between  the  part  marked  6  and  the 
tubes  c,  the  gas  becomes  mixed  with  the  heated  atmospherical  air. 

This  combustible  gas  from  the  blast  furaace,  mixed  with  the  heated  air,  produces  an 
intense  heat  in  the  furnace,  adequate  to  the  refining  of  iron.  Tlie  warm  air  for  burning 
the  gas  is  usually  obtained  from  the  blowing  machine  and  hot  blast  pipes. 


\ 


IRON. 


1109 


For  giving  a  still  greater  heat,  the  air  may  be  carried  through  the  tube  f,  into  the 
iron  chambers  ^^f,  or  a  system  of  pipes,  whence  it  is  led  through  the  tube  h  into  the 
semi-circular  chamber  t,  and  then  through  the  small  pipes  c,  c,  c.  into  the  furnace. 

The  metal  to  be  refined  is  placed  in  the  space  d  d,  in  a  liquid  state,  if  the  arrange- 
ment of  the  furnaces  will  admit  of  its  being  so  taken  from  the  blast  furnace  ;  if  not,  it 
may  be  nearly  melted  by  the  waste  heat  in  the  chamber  e  e.  In  order  to  decarbonize 
the  metal,  a  quantity  of  warm  air,  from  the  pipe  h,  is  conducted  through  the  pipe  k, 
which  is  divided  into  two  nozzles  or  tuyeres  II,  and  blown  upon  the  fluid  metal  in  the 
space  dd.  After  having  been  thus  exposed  for  an  hour  or  two,  it  is  run  off  through 
the  opening  «»,  and  will  be  found  in  a  refined  state. 

Figs.  823, 824,  show  the  application  to  a  puddling  furnace.  The  openings  n  n  admit 
a  stream  of  cold  water  to  flow  through  the  cast-iron  piece  ^  7,  to  preserve  it  from  injury 
by  the  fire. 


824 


823 


CI^^*-^ 


Jtg.824is  a  welding  furnace;  the  interior  dimensions  and  the  casing  of  the  hearti 
bemg  different,  as  well  as  the  fire  bridge,  from  those  of  the  puddling  furnace.  The 
pipes  fbr  conductmg  the  gases  are  made  of  cast-iron,  and  must  have  at  least  a  sectional 
area  of  one  foot  for  every  furnace  that  is  to  be  heated. 

Figs.  825,  826,  827,  828,  829.  show  the  application  of  this  invention  to  the  geneT5stion 
of  steam.    A  chimney  is  here  employed  only  at  the  commencement  of  the  operation.    Tb* 


822 


828 


826 


vcnfenr^at '''¥he^?„H  i^'^^  of  blowing  machine,  or  in  any  other  con 

vcnieni  way.     1  he  fuel  is  introduced  into  the  fireplace,  upon  the  grate  n  7/   throucrh 

br  st'eml  hturs'  '  WheV\?''f    The  fireplace  mus't  contai'n  as  muci  ^id^s^wK 
^rHJno?  •  ^"^  ^^''^  ^'^^  '^  ^'^^^  lighted,  the  combustion  takes  place  in  the 

a  cur"^l''ot^'  aTr  T T^  '^  ^""''  1'  '"'^.  ^'«  slide-valve  6,  and  carrying'  thro'igh  them 
furnace  or  anvwnrl?-  .'  ""?^  '^'^''^^'^'  ^^^^«  '^  continued  till  the  steam-engine 
is  "muloved  to  Tri  t^.^^^'^f.^  ''''^'^V^  '"^  operation,  after  which  a  blowing  apparatus 
18  (fmplojed  to  force  the  air  through  the  tube  c,  as  shown  in^g.  826    The  openin-s  d 


1110 


IRON. 


and  6  are  then  closed;  the  air  forced  in  now  passes  through  the  flues  /,/",/,  placed 
round  and  beneath  the  boiler.  The  air,  on  arriving  at  the  point  g,  is  divided,  one 
portion  passes  through  the  opening  A,  regulated  by  a  valve,  into  the  open  space  beneath 
the  grate  n  n,  to  assist  in  the  slow  combustion  of  the  fuel.  The  other  part  of  the  air 
passes  through  //,  into  h  h,  round  the  fire-place,  in  order  to  heat  the  air  to  an  intense 
degree.  After  the  second  portion  of  the  air  has  passed  into  the  chamber  h  h,  it  enters 
another  i  i,  thence  through  a  series  of  blowpipes,  or  through  o,  into  p  p,  beneath  the 
boiler.  The  burnt  air  goes  off  through  p  p,  into  a  small  chimney,  through  the  opening 
b  b,  which  is  regulated  by  a  valve. 

IRON.  Hot  Blast.  To  the  account  of  this  interesting  inaovation  in  the  smelting 
of  iron  ores,  given  in  tlie  dictionary,  I  have  now  the  pleasure  of  representing  in 
accurate  plans,  the  complete  system  mounted  at  the  Codner  Park  Works  belonging  to 
William  Jessop,  Esq.  For  the  drawings,  from  which  the  woodcuts  are  faithfully 
copied,  I  am  iadebted  to  Mr.  Joseph  Glynn,  F.R.S.,  the  distinguished  engineer  of  the 
Bulterly  Iron  Works. 

i^'ig*.  830,  8')1, 832,  exhibit  the  apparatus  of  the  hot  blast  in  every  requisite  detail. 
The  smelting  furnaces  have  now  generally  three  tuvcres,  and  three  sets  of  air  heating 


a»     > 


furnaces.  The  figures  show  two  sets  built  together ;  the  thira  set  being  detached  oa 
account  of  peculiar  local  circumstances.  The  air  enters  tlie  horizontal  pipe  A,  in  the 
ground  plan.  Jig.  830,  on  one  side  of  the  arched  or  syphon  pipes,  shown  in  upright 
section  inJip.S'Sl,  and  passes  through  these  pipes  to  the  horizontal  pipe,  B,  on  the 
other  side ;  whence  it  proceeds  to  the  blast  furnace.  These  syphon  pipes  are  flattened 
laterally,  their  section  being  a  parallelogram,  to  give  more  heating  surface,  and  also 
more  depth  of  pipe  (in  the  vertical  plane),  so  as  to  make  it  stronger,  and  less  liable  to 


► 


'^" 


I'^i 


# 


IRON. 


1111 


bend  by  its  own  weight  when  softened  by  the  red  heat.     This  system  of  arched  pipe 

apparatus  is  set  in  a  kind  of  oven,  from  which  the  flue  is  taken  out  at  the  top   of  it ; 

t)ut  it  thence  again  descends,  before  it  reaches  the  chimney,  entering  it  nearly  al  the 

level  of  the  fire  grate  (as  with  coal  gas  retorts).     By  this  contrivance,  the  nii^es  are 

kept  in  a  bath  of  ignited  air,  and  not  exposed  to  the  corroding  influence  of  a  current  of 

flame.     The  places  and   directions  of  these  oven  flues  are  plainly  markea  in  th« 

drawing. 

Fig,  87  is  a  plan  of  the  blast  furnace,  drawn  to  a  smaller  «caie  than  th»-  ct  th« 

©receding  figures. 


lMliihihT|- 


5 


The  three  sets  of  hot-blast  apparatus,  all  communicate  with  one  line  of  conductmg 
pipes.  A,  which  leads  to  the  furnace.  Thus  in  case  of  repairs  being  required  in  one 
set,  the  other  two  may  be  kept  in  full  activity,  capable  of  supplying  abundance  of  hot 
air  to  the  blast,  though  of  a  somewhat  lower  temperature.  See  Smelting  for  con- 
structions  of  diff'erent  blast  furnaces ;  also  Puddmng. 

During  a  visit  which  I  have  recently  made  to  Mr.  Jessop,  at  Butterley,  I  f(»und  (hi» 


I1I2 


IRON. 


eminent  and  very  ingenious  iron-master  had  made  several  improvements  upon  nis  hot- 
blast  arrangements,  whereby  he  prevented  the  alteration  of  form  to  which  the  arched 
pipes  were  subject  at  a  high  temperature,  as  also  that  he  was  about  to  employ  five 
tuyeres  instead  of  three.  For  a  drawing  and  explanation  of  his  furnace-feeding 
apparatus,  see  Smelting. 

IRON  CAST,  improvedhy  combination  with  vrrought  iron.  This  improvement,  invented 
and  patented  by  Mr.  Morries  Stirling,  has  been  reported  upon  by  the  Government 
Commissioners  on  the  application  of  iron  to  railway  purposes.  It  is  applicable  to  both 
cast  and  wrought  iron.  A  mixture  of  the  two  in  certain  proportions  has  the  effect  of 
giving  a  fibrous  nature  to  the  cast  metal,  and  thereby  greatly  increasing  its  strength  and 
tenacity.  For  all  kinds  of  beams,  girders,  and  other  castings  where  strength  is  required, 
its  use  is  found  very  advantageous  and  economical.  Beams  cast  of  such  toughened  iron 
may  be  made  of  less  dimensions  to  support  the  same  load ;  and  they  have  the  advantage 
of  deflecting  to  a  greater  extent,  and  are  therefore  not  so  liable  to  sudden  failure.  At 
page  101.  of  the  Commissioners'  Report,  an  abstract  is  given  of  a  series  of  trials,  from 
which  it  will  be  seen  that  Mr.  Stirling's  alloy  is  nearly  50  per  cent,  superior  to  16  other 
sorts  of  iron  experimented  upon.  Various  other  experiments  have  been  made  by  Mr. 
Owen  for  the  Admiralty,  and  by  Messrs.  Rennie  and  others,  all  with  the  same  results, 
showing  the  increase  of  strength  in  the  patent  iron.  Common  Scotch  pig  iron  thus 
toughened  can  be  had  now  (1851)  for  about  2/.  10».  per  ton ;  and  it  is  at  least  50  per 
cent  stronger  than  the  best  Blaenavon  iron,  which  costs  3/.  3s.  per  ton. 

The  improvements  in  the  manufacture  of  torought  iron  are,  first,  the  admixture  of  a 
certain  alloy  in  the  puddling  furnace,  by  which  all  malleable  iron  is  rendeied  much 
more  fibrous  and  tougher  than  common  wrought  iron,  so  much  so  that  common  or 
merchant  bar  becomes  equal  to  best  bar,  thus  saving  one  process  to  the  manufacturer. 
Also  very  ordinary  iron,  which  can  scarcely  be  used  at  all,  is  made  equal  to  the  best.  The 
'olio wing  abstracts  of  experiments  are  given  in  the  Report  of  Commissioners  (p.  417.^ 


IRON  ORES. 


1113 


V 


\i 


»: 


Breaking  Strain 

in  Tons  per 

Square  Inch. 


23-23 

24-47 
24-33 
27-81 
27-70 


Average  of  Mr.  Jesse  Hartley's  experiments  at  Liverpool  on  many 
sorts  of  malleable  iron  -  -  •  -  - 

Average  of  S.  C.  Crown  Iron  from  numerous  trials  at  Woolwich 
Dockyard  -  -  .  .  -  -  - 

Average  of  best  Dundy  van  bar  ,  .  .  -  - 

Average  of  Mr.  Sterling's  best  quality  .  .  .  - 

Do.        another  quality        ....-- 

Tlie  cost  of  the  process  is  only  a  few  shillings  per  ton.  When  Mr.  Stirling's  toughened 
pig  is  used  in  the  puddling  furnace  instead  of  common  pig,  and  the  alloy  added,  an  iron 
is  produced  of  a  very  superior  quality,  of  a  very  fibrous  nature,  and  much  finer  in  the 
fibre  than  the  iron  mentioned  above;  this  will  be  found  very  advantageous  m  the  manu- 
facture of  thin  plates  and  sheets. 

Second,  the  admixture  of  a  different  alloy  in  the  puddling  furnace,  whereby  a  quantity 
of  iron  is  produced  quite  opposite  in  its  character  to  the  last ;  instead  of  being  fibrous, 
it  becomes  hard  and  crystalline,  approaching  to  the  nature  of  steel.  The  average 
streno-th  of  common  round  bars,  1  inch  diameter,  is  about  3  inches  per  foot ;  whereas  the 
average  of  Mr.  Stirling's  hardened  iron  is  from  one-eighth  to  three-eighths  q/"  au  inch 
per  foot .  This  shows  the  great  stiffness  obtained  by  this  method.  The  crystalline 
nature  of  this  description  of  iron  causes  it  to  resist  compression,  lamination,  and  abrasion. 
Thus  for  the  top  portions  of  wrought  iron  girders,  it  is  precisely  what  is  required 
to  resist  the  compression  force,  the  fibrous  iron  being  used  for  the  bottom  portion,  to 
resist  the  tension.  For  rails  and  tyres  for  wheels  this  sort  of  iron  is  peculiarly  adapted ; 
the  top  of  the  rails  and  the  outside  of  the  tyres  being  made  with  it.  will  resist  the  wear 
and  tear  and  lamination  so  universally  complained  of;  and  rails  made  of  the  patent  iron 
are  found  to  answer  remarkably  well.  They  have  been  used  on  the  East  Lancashire, 
Caledonian,  Edinburgh  and  Glasgow,  and  other  railways,  with  great  success  ;  the  extra 
cost  of  rails  made  of  this  iron  being  only  from  7«.  6t/.  to  10«.  per  ton. 

The  first  of  these  improvements  in  the  manufacture  of  metallic  sheets  is  the  use 
of  polished  rolls  to  such  sheets  as  are  either  intended  for  being  coated  with  other  metals, 
or  after  such  sheets  have  been  bo  coated ;  and  this  improvement  is  more  particularly 
applicable  to  iron  plate  either  coated  or  to  be  coated  with  tin,  zinc,  or  other  of  the  more 
fusible  metals.  After  the  plates  or  sheets  of  iron  have  been  cleaned  by  pickling  or  other- 
wise in  the  usual  way,  they  are  to  be  passed  between  polished  rollers,  using  sufficient 
pressure  to  smooth  the  surface  without  injuring  the  quality  by  producing  brittleness ; 
and  as  iron  is  of  such  different  qualities  as  regards  its  ductility,  both  when  hot  and  cold 
(according  to  the  district  from  whence  the  ore  is  produced,  and  peculiarities  of  make,) 
no  absolute  rule  respecting  the  amount  of  pressure  can  be  given,  but  a  little  practice 
will  enable  a  workman  to  judge,  and  care  is  to  be  taken  that  the  rolls  are  clean.  The 
plates  so  polished  are  then  to  be  dipped  in  the  usual  manner  into  the  metal  or  alloy  in- 
tended for  the  coating.  After  the  plates  or  sheets  have  been  coated  with  any  metal  or 
allo3^  they  are,  where  a  high  degree  of  smoothness  is  desired,  again  passed  between 
polished  rolls,  the  degree  of  pressure  being  carefully  regulated  so  as  to  avoid  producing 
brittleness.  It  is  not  essential  that  the  sheets  of  metal  should  be  passed  between  the 
smooth  rolls  before  coating,  but  it  is  preferred  that  such  should  be  the  case. 

Ikon  Cast,  Enamelled.     The  Great  Exhibition  contained  the  following  examples. 
Model  of  an  enamelled  tank  or  cistern  composed  of  cast  iron  plates,  screwed  together 
with  gutta  percha joint. 

Model  of  enamelled  water  or  gas  pipes  and  watercloset  pan,  with  trap  pipe  ;  dry 
trough,  poultry  trough,  and  spittoon. 

The  application  of  enamel  for  the  protection  of  water  cistern  pipes,  <fec  from  oxida- 
tion and  for  the  lining  of  cooking  utensils  is  of  comparatively  recent  date.  The  various 
materials  of  which  the  coating  is  composed  (silex  being  the  principal)  are  reduced  to  a 
fluid  state :  the  article  to  be  coated  is  dipped  in  the  mass  ;  a  portion  of  the  fluid 
adheres  ;  it  is  then  subjected  to  the  heat  of  a  muffle,  and  the  whole  becomes  vitrified  or 
reduced  into  a  glossy  covering,  affording  an  excellent  defence  against  oxidation,  and  a 
sulistitute  for  the  protection  afforded  by  tinning. 
Iron.  Zinking  of.     See  Zinking. 

IRON  ORES  (Analysis  of,  by  Bichromate  of  Potash).  A  convenient  quantity  of 
the  specimen  is  reduced  to  coarse  powder,  and  one-half  at  least  of  this  still  further  pul- 
verized, until  it  is  no  longer  gritty  between  the  fingers.  The  test  solution  of  bichro- 
mate of  potash  is  next  prepared.  44-4  gr.  of  the  salt  in  fine  powder  are  weighed  out, 
and  put  into  an  alkalimeter  (graduated  itito  100  divisions),  and  tepid  distilled  water 
afterwards  poured  in  until  tlie  instrument  is  filled  to  0.  Tlie  palm  of  tlie  hand  is  then 
securely  placed  on  the  top,  and  the  contents  agitated  by  repeatedly  invertintr  the  in* 


1114 


IRON  ORES. 


ISINGLASS. 


1115 


Btrument  until  the  salt  is  dissolved,  and  the  solution  rendered  of  uniform  density 
throughout.  It  is  obvious  that  each  division  of  the  solution  thus  prepared  contain!* 
0444  gv.  of  bichromate,  which  corresponds  to  ^  a  giain  of  metallic  iron.  The  bichro- 
mate of  potash  used  in  this  process  must  of  course  be  purchased  pure,  or  made  so  by 
repeated  crystallization,  and  it  should  be  thoroughly  dried  by  being  heated  to  incipient 
infusion. 

100  grains  of  the  pulverized  ironstone  are  now  introduced  into  a  Florence  flask,  with 
1^  oz.  by  measure  of  strong  hydrochloric  acid,  and  i  an  ounce  of  distilled  water.  Heat 
is  cautiously  applied,  and  the  mixture  occasionally  agitated,  until  the  effervescence 
caused  by  the  escape  of  the  carbonic  acid  ceases  ;  the  heat  is  then  increased  and  the 
mixture  made  to  boil,  and  kept  at  moderate  ebullition  for  ten  minutes  or  a  quarter  of 
an  hour.  During  these  operations  it  will  be  advisable  to  incline  the  flask,  in  order  to 
avoid  the  projection  and  consequent  loss  of  any  portion  of  the  liquid  by  spirting. 
About  6  oz.  of  water  are  next  added,  and  mixed  with  the  contents  of  the  flask,  and  the 
whole  rapidly  transferred  to  an  evaporating  basin.  The  flask  is  rinsed  several  times  with 
water  to  remove  all  adhering  solution. 

Several  small  portions  of  a  weak  solution  of  pure  red  prussiate  of  potash  (containing 
1  part  of  the  salt  to  40  of  water)  are  now  dropped  upon  a  white  porcelain  slab,  which  is 
conveniently  placed  for  testing  the  solution  in  the  basin  during  the  next  operation. 

The  prepared  solution  of  bichromate  of  potash  in  the  alkalimeter  is  then  added  very 
cautiously  fo  the  solution  of  iron,  which  must  be  repeatedly  stirred,  and  as  soon  as  it 
assumes  a  dark  greenish  shade,  it  should  be  occasionally  tested  with  the  red  prussiate  of 
potash.  This  may  be  easily  done  by  taking  out  a  small  quantity  on  the  end  of  a  glass 
rod,  and  mixing  it  with  a  drop  of  the  solution  on  the  porcelain  slab.  When  it  is  noticed 
that  the  last  drop  communicates  a  distinct  red  tinge,  the  operation  is  terminated.  The 
alkalimeter  is  allowed  to  drain  for  a  few  minutes,  and  the  number  of  divisions  of  the  test 
liquor  consumed  read  off.  This  number  multiplied  by  2  gives  the  amount  of  iron  per 
cent,  in  the  specimen  of  ironstone,  assuming  that,  as  directed,  100  grs.  have  been  used 
for  the  experiment.  The  necessary  calculation  for  ascertaining  the  corresponding  quan- 
tity of  protoxide  is  obvious. 

When  black-band  ironstone  is  the  subject  of  analysis,  or  when  the  ore  affords  indica- 
tions by  its  appearance,  or  during  the  treatment  with  hydrochloric  acid,  that  it  con- 
tains an  appreciable  quantity  of  carbonaceous  matter,  then  the  hydrochloric  acid  solu- 
tion must  be  filtered  before  being  transferred  to  the  basin,  and  the  filter,  with  the  in- 
soluble ingredients,  must  be  washed  in  the  usual  way  with  warm  distilled  water,  slightly 
acidulated  with  hydrochloric  acid,  until  the  filtrate  ceases  to  give  a  blue  colour  with  red 
|)russiate  of  potash.  In  those  cases,  also,  where  the  presence  of  iron  pyrites  in  the 
ironstone  is  suspected,  it  will  be  necessary  to  remove  the  insoluble  matter  by  filtering 
l)efore  using  the  bichromate  solution  ;  but  with  ironstones  in  which  the  insoluble  ingredi- 
ent." are  merely  clay  and  silica,  filtration  is  not  essential. 

Now  it  is  evident  that  the  foregoing  process,  so  far  as  I  have  described  it,  serves  for 
the  determination  of  that  portion  of  iron  only  which  exists  in  the  ore  in  the  state  of 
protoxide.  But  many  specimens  of  the  common  ironstone  of  this  country  contain  ap- 
preciable quantities  of  peroxide  of  iron,  which,  being  unacted  upon  by  the  bichromate  of 
potash,  would  escape  estimation  by  the  present  method.  By  an  additional  and  easy 
operation,  however,  the  amount  of  metallic  iron  in  this  ingredient  may  be  likewise  de- 
termined. It  is  only  necessary  to  reduce  it  to  the  minimum  state  of  oxidation,  and  then 
to  add  the  bichromate,  as  previously  directed. 

The  best  and  most  convenient  agent  for  effecting  the  reduction  of  the  persalts  of  iron, 
la  sulphite  of  soda.  The  only  precaution  to  be  observed  is  to  use  it  in  sufficient 
quantity,  and  at  the  same  time  to  take  care  that  the  iron  solution  contains  excess  of 
acid.  When  the  reduction  is  complete,  a  few  minutes'  ebullition  suffices  to  decompose 
the  excess  of  sulphite  of  soda,  and  effectually  to  expel  every  trace  of  sulphurous  acid. 

In  order  to  test  the  exactness  of  this  mode  of  estimating  the  iron  in  the  peroxide,  I 
made  several  experiments  with  peroxide  prepared  from  known  quantities  of  pure  iron 
wire.  The  peroxide  was  thoroughly  washed,  dissolved  in  hydrochloric  acid,  reduced 
with  sulphite  of  soda,  and  after  complete  expulsion  of  the  excess  of  sulphurous  acid,  the 
solution  was  diluted  with  water  and  treated  with  bichromate  of  potash.  I  select  three 
of  the  experiments : — 

Exp.  I. 

Exp.  n. 

Exp.  III. 

The  mean  of  all  my  experiments  on  this  point  gives  the  ratio  of  100  of  iron  to  88'6  of 
bichromate,  which  is  in  close  accordance  with  the  former  results. 

Whenever,  therefore,  the  ore  of  iron  contains  pero.\ide,  it  will  bo  necessary  to  add 
solphitc  of  soda  to  the  hydrochloric  acid  solution  before  the  addition  of  the  test  liquor 


10  grs.  of  iron  consumed     8*87  of  bichromate. 
18  ^  do.         do.  15-94  d<». 

25  do.         do.  2215  do. 


i 


from  the  alkalimeter.  The  sulphite  should  be  dissolved  in  distilled  water,  and  added 
to  the  solution  of  iron  in  small  successive  portions,  until  a  drop  of  the  liquor  gives 
merely  a  rose  pink  colour  with  sulpho-cyanide  of  potassium,  which  indicates  that  the 
reduction  of  the  persalt  of  iron  is  sufficiently  perfect.  The  liquid  is  now  heated  till  the 
odour  of  sulphurous  acid  is  no  longer  perceptible.  These  operations  should  be  per- 
formed while  the  solution  is  in  the  flask,  and  before  it  is  filtered  or  transferred  to  the 

basin. 

I  will  here  mention,  for  the  guidance  of  those  who  may  not  be  fully  aware  of  the 
reactions  of  the  oxides  of  iron,  that  the  existence  of  an  appreciable  quantity  of  peroxide 
in  the  ironstone  may  be  readily  discovered  by  dissolving  (as  directed  in  the  process)  30 
or  40  grs.  of  the  ore  in  hydrochloric  acid,  diluting  with  about  8  oz.  of  water,  filtering 
and  testing  a  portion  of  the  solution  with  sulpho-cyanide  of  potassium.  If  a  decided 
dark  blood-red  colour  is  produced,  the  quantity  of  peroxide  in  the  stone  must  be  deter- 
mined •  but  if  the  colour  is  only  light  red  or  rose  pink,  the  proportion  is  exceedingl}' 
small,  and  for  practical  purposes  not  worth  estimating.  Of  course,  when  the  specimen 
of  ironstone  has  an  ochrey  or  a  reddish  appearance  on  the  surface  or  in  the  fracture,  the 
presence  of  a  large  proportion  of  peroxide  is  indicated,  and  its  exact  quantity  must  be 

determined. 

In  conclusion,  I  must  not  omit  to  notice  one  or  two  circumstances  which,  appear  at 
first  to  militate  against  the  accuracy  of  this  process.  It  may  be  questioned  whether 
solutions  of  the  protosalts  of  iron  do  not  absorb  oxygen  so  rapidly  from  the  air  as  to  in- 
fluence the  results  obtained  by  this  method.  Marguerite  has  shown,  and  my  own  <»b- 
eervations  completely  confirm  his  statement,  that  protosalts  of  iron,  in  an  acid  solution, 
l>ecome  peroxydized  very  slowly  ;  and,  in  a  particular  exjjeriment,  I  found  that  contact 
with  the  air  during  several  hours  caused  no  diminution  in  the  quantity  of  bichromate 
of  potash  required.  As  the  process  may  be  completed  in  a  few  minutes,  it  is  certain 
that  no  inaccuracy  can  arise  from  this  cause. 

It  is  also  important  to  inquire  whether  the  chromic  acid  in  the  chromates  of  potash 
may  not  be  partially  deoxydized  by  hydrochloric  acid  alone  without  the  presence  of  a 
protosalt  of  iron.  Such  a  reaction  would  obviously  give  rise  to  a  serious  error.  It  is 
well  known  that  concentrated  hydrochloric  acid  rapidly  decomposes  the  chromic  acid  of 
the  chromates  when  aided  by  the  application  of  heat.  But  I  have  satisfied  myself,  by 
numerous  experiments,  that  this  acid  exerts  very  little  appreciable  action  upon  dilute 
solutions  of  the  chromates  of  potash,  either  cold  or  warm,  and  that  the  action  is  only 
partial  even  after  continued  ebullition  ;  so  that  the  present  method  is  free  from  inaccu- 
racy on  this  account. — Dr.  Penney. 

Bronzing  of  polished  iron. — The  barrels  of  fowling-pieces  and  rifles  are  occasionally 
bronzed  and  varnished,  to  relieve  the  eye  of  the  sportsman  from  the  glare  of  a  polished 
metal,  atid  to  protect  the  surface  from  rusting.  The  liquid  used  for  browning  the  barrels 
is  made  by  mixing  nitric  acid  of  specific  gravity  1.2,  with  its  own  weight  of  spirit  of  nitric 
ether,  of  alcohol,  and  tincture  of  muriate  of  iron  ;  and  adding  to  that  mixture  a  quantity 
of  sulphate  of  copper  equal  in  weight  to  the  nitric  acid  and  ethereous  spirit  taken  toge- 
ther. The  sulphate  must  be  dissolved  in  water  before  being  added ;  and  the  whole  being 
diluted  with  about  10  times  its  weight  of  water,  is  to  be  bottled  up  for  use.  This  liquid 
must  be  applied  by  friction  with  a  rag  to  the  clear  barrel,  which  must  then  be  rubbed 
with  a  hard  brush  ;  processes  to  be  alternated  two  or  three  times.  The  barrel  should  be 
afterwards  dipped  in  boiling  water,  rendered  feebly  alkaline  with  carbonate  of  potash  or 
soda,  well  dried,  burnished,  and  heated  slightly  for  receiving  several  coats  of  tin-smith's 
lacquer,  consisting  of  a  solution  of  shellac  in  alcohol,  coloured  with  dragon's  blood. 

ISINGLASS,  or  Fish  glue,  called  in  Latin  ichthyocolla,  is  a  whitish,  dry,  tough,  semi- 
transparent  substance,  twisted  into  different  shapes,  often  in  the  form  of  a  lyre,  and 
consisting  of  membranes  rolled  together.  Good  isinglass  is  unchangeable  in  the  air,  has 
a  leathery  aspect,  and  a  mawkish  taste,  nearly  insipid ;  when  steeped  in  cold  water  it 
swells,  softens,  and  separates  in  membranous  laminae.  At  the  boiling  heat  it  dissolves 
in  water,  and  the  solution,  on  cooling,  forms  a  white  jelly,  which  is  semi-transparent, 
soluble  in  weak  acids,  but  is  precipitated  from  them  by  alkalis.  It  is  gelatine  nearly 
pure  ;  and  if  not  brittle,  like  other  glue,  this  depends  on  its  fibrous  and  elastic  texture. 
The  whitest  and  finest  is  preferred  in  commerce.  Isinglass  is  prepared  from  the  air- 
bladders  of  sturgeons,  and  especially  the  great  sturgeon,  the  accipenser  huso ;  which  is 
fished  on  the  shores  of  the  Caspian  Sea,  and  in  the  rivers  flowing  into  it,  for  the  sake 
chiefly  of  its  swim  bladder. 

The  preparations  of  isinglass  in  this  part  of  Russia,  and  partictilarly  at  Astracan, 
consists  in  steeping  these  bladders  in  water,  removing  carefully  their  external  coat,  and 
the  blood  which  often  covers  them,  putting  them  into  a  hempen  bag,  squeezing  them, 
softening  them  between  the  hands,  and  twisting  them  into  small  cylinders,  which  are 
afterwards  bent  into  the  shape  of  a  lyre.  They  are  ready  for  the  market  immediately 
after  being  dried  in  the  sun,  and  whitened  with  the  fumes  of  burning  sulphur. 


1116 


ISLAND  MOSS. 


In  some  districts  of  Moldavia,  another  process  is  followed.  The  skin,  the  stomach, 
the  intestines,  and  the  swim  bladder  of  the  sturgeon  are  cut  in  small  pieces,  steeped  in 
cold  water,  and  then  gently  boiled.  The  jelly  thus  obtained  is  spread  in  thin  layers  to 
dry,  when  it  assumes  the  appearance  of  parchment.  This  being  softened  in  a  little  water, 
then  rolled  into  cylinders,  or  extended  into  plates,  coiic*!tutes  an  inferior  article. 

The  swim  bladder  of  the  cod  and  many  other  fishes  also  furnishes  a  species  of  isin- 
glass, but  it  is  much  more  membranous,  and  less  soluble,  than  that  of  the  sturgeon. 

The  properties  of  isinglass  are  the  same  as  those  of  gelatine  or  pure  glue ;  and  its  uses 
are  very  numerous.  It  is  employed  in  considerable  quantities  to  clarify  ale,  wine,  liqueurs, 
and  coffee.  As  an  article  of  food  to  the  luxurious  in  the  preparation  of  creams  and  jel- 
lies, it  is  in  great  request.  Four  parts  of  it  convert  100  of  water  into  a  tremulous  jelly, 
which  is  employed  to  enrich  many  soups  and  sauces.  It  is  used  along  with  gum  as  a 
dressing  to  give  lustre  to  ribands  and  other  silk  articles.  The  makers  of  artificial  pearls 
employ  it  to  fix  the  essence -d' Orient  on  the  glass  globules  which  form  these  pearls,  and 
the  Turks  set  their  precious  stones  or  jewellery  by  means  of  isinglass  dissolved  in  alco- 
hol along  with  gum  ammoniac  ;  a  combination  which  is  also  employed  in  this  country  to 
join  broken  pieces  of  China  and  glass,  under  the  name  of  diamond  cement.  That  setting 
preserves  its  transparency  after  it  solidifies,  if  it  be  well  made. 

It  is  by  covering  taffety  or  thin  silk  with  a  coat  of  isinglass  that  court  plaster  is  made. 
A  solution  of  isinglass  colored  with  carmine  forms  an  excellent  injection  liquor  to.  the 
anatomist.  M.  Rochen  has  made  another  pretty  application  of  isinglass.  He  plunges 
into  a  limpid  solution  of  it,  made  by  means  of  a  water  bath,  sheets  of  wire  gauze  set  in 
window  or  lamp  frames,  which,  when  cold,  have  the  appearance  of  glass,  and  answer  in- 
stead of  it  for  shades  and  other  purposes.  If  one  dip  be  not  sufficient  to  make  a  proper 
transparent  plate  of  isinglass,  several  may  be  given  in  succession,  allowing  each  film  to 
harden  in  the  interval  between  the  dips.  The  outer  surface  should  be  varnished  to  pro- 
tect it  from  damp  air.  These  panes  of  gelatine  are  now  generally  used  for  lamps  instead 
of  horn,  in  the  maritime  arsenals  of  France, 

Isinglass  imported  for  home  consumption,  and  duties  paid,  in 
1835.  1836.  1835.  1836. 

1,814  cwts.      I      1,735  cwts.    |     £4Ji90  |       £4,125 

ISLAND  MOSS  (Lichen  d'Islande,  Fr. ;  Flechte  IsL,  Germ.)  is  a  lichen,  the  Cetraria 
islandica,  which  contains  a  substance  soluble  in  hot  water,  but  forming  a  jelly  when  it 
cools,  styled  lichenine  by  M.  Guerin.  Lichenine  has  a  yellowish  tint  in  the  dry  state,  is 
transparent  in  thin  plates,  insipid,  inodorous,  and  difiicult  to  pulverize.  Cold  water  makes 
it  swell,  but  does  not  dissolve  it.  It  is  precipitated  in  white  flocks  by  alcohol  and  ether. 
Iodine  tinges  it  of  a  brownish-green.  Sulphuric  acid  converts  it  into  sugar ;  and  the 
nitric  into  oxalic  acid.  Lichenine  is  prepared  by  extracting  first  of  all  from  the  plant  a 
bitter  coloring  matter,  by  digesting  1  pound  of  it  in  16  pounds  of  cold  water,  containing 
1  ounce  of  pearlash ;  then  draining  the  lichen,  edulcorating  with  cold  water,  and  boiling 
it  in  9  pounds  of  boiling  water  till  3  pounds  be  evaporated.  The  jelly  which  forms,  upon 
cooling  the  filtered  solution,  is  dark  colored,  but,  being  dried  and  redissolved  in  hot  water, 
it  becomes  clear  and  colorless.  Lichenine  consists  of  39-33  carbon,  7*24  hydrogen,  and 
55-43  oxygen.  With  potash,  lime,  oxyde  of  lead,  and  tincture  of  galls,  the  habitudes  of 
lichenine  and  starch  are  the  same.  The  mucilage  of  island  moss  is  preferred  in  Ger- 
many  to  common  paste  for  dressing  the  warp  of  webs  in  the  loom,  because  it  remains 
soft,  from  its  hygrometric  quality.  It  is  also  mixed  with  the  pulp  for  sizing  paper  in 
the  vat. 

IVORY  (Ivoire,  Fr. ;  Elfeitbein,  Germ.)  is  the  osseous  matter  of  the  tusks  and 
teeth  of  the  elephant,  the  hippopotamus,  or  morse,  wild  boar,  several  species  ot  phocee, 
as  well  as  the  horn  or  tooth  of  the  narwhal.  Ivory  is  a  white,  fine-grained,  dense  suh- 
stance,  of  considerable  elasticity,  in  thin  plates,  and  more  transparent  than  paper  of  equal 
thickness.  The  outside  of  the  tusk  is  covered  by  the  cortical  part,  wliich  is  softer  and 
less  compact  than  the  interior  substance,  with  the  exception  of  the  brown  plate  that 
sometimes  lines  the  interior  cavity.  The  hardest,  toughest,  whitest,  and  most  translucent 
ivory,  has  the  preference  in  the  market ;  and  the  tusks  of  the  sea-horse  are  considered 
to  afford  the  best.  In  these,  a  rough  glassy  enamel  covers  the  cortical  part,  of  such 
hardness,  as  to  strike  sparks  with  steel.  The  horn  of  the  narwhal  is  sometimes  ten  foet 
long,  and  consists  of  an  ivory  of  the  finest  description,  as  hard  as  that  of  the  elephant, 
and  susceptible  of  a  better  polish ;  but  it  is  not  in  general  so  much  esteemed  as  the 
latter. 

Ivory  has  the  same  constituents  as  the  teeth  of  animal?,  three  fourths  being  phosphate, 
irith  a  little  carbonate  of  lime  ;  one  fourth  cartilage.     See  Bones. 

It  is  extensively  employed  by  miniature  painters  for  their  tablets;  by  turners,  in 
making  numberless  useful  and  ornamental  objects ;  by  cutlers,  for  the  handles  of  knives 
and  forks ;  by  comb-makers ;  as  also  by  philosophical  instrument  makers,  for  constructing 


IVORF. 


1117 


the  scales  of  thermometers,  &c.  The  ivory  of  the  sea-horse  is  preferred  by  aentists  for 
makmg  artificial  teeth;  that  of  the  East  India  elephant  is  better  than  of  the  African. 
V\  hen  It  shows  cracks  or  fissures  in  its  substance,  and  when  a  spUnter  bioken  off  has  a 
duU  aspect,  it  is  reckoned  of  inferior  value.  Ivory  is  distinguishable  from  bone  by  its 
peculiar  semi-transparent  rhombohedral  net-work,  which  may  be  readily  seen  in  slips  of 
ivory  cut  transversely. 

^  l?""*  i^  JV  "^^u.^"  *^^^  ^  yellow-brown  tint  by  exposure  to  air.      It  may  be  whitened 
or  bleached,  by  rubbing  it  first  with  pounded  pumice-stone^nd  water,  then  placing  it  moist 
under  a  glass  shade  luted  to  the  sole  at  the  bottom,  and  exposing  it  to  sunshine.      The 
sunbeams  without  the  shade  would  be  apt  to  occasion  fissures  in  the  ivory      The  moist 
rubbing  and  exposure  may  be  repeated  several  times. 
For  etching  ivory,  a  ground  made  by  the  foUowing  recipe  is  to  be  applied  to  the  polish- 
t  u  »?  "7^^^^  °^  pure  white  wax,  and  transparent  tears  of  mastic,  each  one  ounce  ; 
asphalt,  half  an  ounce.      The  mastic  and  asphalt  having  been  separately  reduced  to  fine 
powder,  and  the  wax  being  melted  in  an  earthenware  vessel  over  the  fire,  the  mastic  is 
to  be  first  slowly  strewed  in  and  dissolved  by  stirring;  and  then  the  asphalt  in  like  man- 
hftK  |'"S/?°;P«'i';d  AS  to  be  poured  out  into  lukewarm  water,  well  kneaded,  as  it  cools, 
by  the  hand,  into  rolls  or  balls  about  one  inch  in  diameter.    These  should  be  kept  wrap- 
C?i  1  '^^^7^^^  ^f^^l' ,  If  ^hite  rosin  be  substituted  for  the  mastic,  a  cheaper  composition 
will  be  obtained,  which  answers  nearly  as  weU ;  2  oz.  asphalt,  1  oz.  rosin,  |  oz.  white 
^^vintTln'T    f  oportio'^s.      Callot's  etching  ground  for  copper  plates,  is  made  by  dis- 

f^rn^i  ^^^V^:,?^  "?^?'^  '"  ^  °^-  ^f  ^^"T^  ^""^  li^s^^d  oil ;  filtering  the  varnish 

through  a  rag,  and  bottling  it  for  use. 

in^^^^V  °V!l^  ^^«  fi^< grp^'ids  being  applied  to  the  ivory,  the  figured  design  is 
urfoc.  if  fn  i  '^"^  ''  '"^  f^  ^t"""^  ^^y'  ^  ^^^?«  °f  ^^^  is  to  be  applied,  and  the 
with  ?L  •?  /  ^\Z  T^'^^  "^^i^  '^""^^^  sulphuric  acid.  The  effect  comes  better  out 
tTon  nV  m?;^  t  ^  ^"^^  ^^^^ '  """"^^^  '^P^*^^'^^  ^^^^  ^^^^^^  ^^  it  becomes  dilute  by  absorb 
Ti^lT  f\^'^^  concentrated  oil  of  vitriol.  Simple  wax  may  be  employed  instead 
of  the  copperplate  engraver's  ground  ;  and  strong  muriatic  acid  instead  of  sulphuric.  If 
an  acid  solution  of  silver  or  gold  be  used  for  etching,  the  design  will  become  purple  or 

Ac7d  C«'tf  n'r -f  '"^  'T^''\  ^^^  ^^^  °^"y  ^^  -^^'^^  ^^^^y  ^ith  oil  of  tu?^ntine 
Acid  nitrate  of  silver  affords  the  easiest  means  of  tracing  permanent  black  lines  upon 

Ivogr  may  be  dyed  by  using  the  following  prescriptions  :- 

nW.;*  r  ^"'^  ^^^.'J'''^'^^  ^^^^  f"^  ^^^^^al  hours  in  a  dUute  solution  of  neutral 
mtiate  of  pure  silver,  with  access  of  light,  it  will  assume  a  black  color  havhi<^  a  Sic^hUv 
^reen  cast      A  stiU  finer  and  deeper  black  may  be  obtained  by  iK^innV  he  iW  f^^^^^^^ 

Tre^aLfaTe^on^oT'"'  "'  ''="'"''  ''^'  ''^'^  ^^^^^^^^^^  "  ^^  ^  '''^'''-  ^^ ^^  -lp"^« 
».nn*J^'*'/f  T^^^l.''''"^'  i'  ^^Pt  immersed  for  a  longer  or  shorter  time  in  a  dilute  solu- 
or  ?esf  infenX'.  '"  ^'""'  ""'"^'"^  ^'''  ^'^'^^^ ''  ^^""^^^  "^  blurtint  of^ea^^^^^ 

3.  Green  dye.— Jhh  is  given  by  dipping  blued  ivory  for  a  Uttle  while  in  solution  of 
aitro-muriate  of  tin,  and  then  in  a  hot  decoction  of  fustic  solution  ol 

th^n  nTf^r  ^^'-l^  ^ir";  ^^  impregnating  the  ivory  first  with  the  above  tin  mordant  and 
then  digesting  ,t  with  heat  in  a  strained  decoction  of  fustic.  The  color  na^L  ,n^^ 
orange,  if  some  Brazil  wood  has  been  mixed  with  the  fustic.  A  ve^  finTunE4ISk 
nf   hrn""";  ^"  ^^''^^^^i^^/^d  to  ivory  by  steeping  it  18  or  24  hou,^\  rstrnXluUon 

Liun^fnf  ,tt7f1f  .^  given  by  imbuing  the  ivory  first  with  the  tin  mordant,  then 
hi  ?£  ?  •.  f-,^*^  "^  ^7^'^  ^"""^^  cochmeal,  or  a  mixture  of  the  two.  Lac-dye  ma>- 
n?nn!^H  72  r.J  ^""'^  advantage,  to  produce  a  scarlet  tint.  If  the  scarlet  ivory  ^ 
plunged  for  a  little  in  a  solution  of  potash,  it  will  become  cherry  red. 

«1mrf  f!  -^f"",  ?1^^"  i".t'^e  l%'W"od    bath,  to  ivory  previously  mordanted   for  a 

short  time  with  soluti.m  of  tin.  When  the  bath  becomes  exhausted,  it  imparts  a  lilac 
Linin/J  W  TP  '«/h«"ged  to  purple-red  by  steeping  it  a  little  while  in  water  con- 
taining a  few  drops  of  nitro-munatic  acid. 

hnfYnr' w^*''*!i**'  ^^^?^  iyory,  it  may  in  general  be  observed,  that  the  colours  penetrate 
better  before  he  surface  is  poh.hed  than  aferwards.  Should  any  dark  spotTappear 
they  may  be  cleared  up  by  rubbing  them  with  chalk ;  after  which  the  ivory  should  b^ 
dyed  once  more  to  produce  perfect  uniformity  of  slvad*.  /  On  fakiirg  ii  i>at.of-the  boili..,.. 
hot  dye  bath  it  ought  to  be  immediately  plunged  into.cold  waiter,  to  m event  liie  ^ha^5 
of  fissures  being  caused  by  the  heat.  '.••.'.,'     z*^'      -    •    .'^  ."'r'.'-V 


a 


If  the  borings  and  chips  of  the  ivory-turner,  caWed  ivory  dust,  be  boiled  in  water 
kind  of  fine  size  18  obtained.  '..'.':  .\  •■•..... 

*    •  •  •  •       - '     •       i  ,      ' '  ;     .'      ■  • 


t 


1118 


IVORY  BLACK. 


The  importation  of  elephants'  teeth  amounts  to  about  5000  cwts,  per  annum. 

Ivory  made  flexible.  Ivory  articles  may  be  made  flexible  and  semi-transparent,  bf 
immersing  them  in  a  solution  of  pure  phosphoric  acid  of  sp.  gr.  1,130,  and  leaving  them 
there  till  they  lose  their  opacity ;  they  are  then  to  be  taken  out,  washed  with  water, 
and  dried  with  a  soft  cloth  ;  it  thus  becomes  as  flexible  as  leather.  It  hardens  on 
exposure  to  dry  air,  but  resumes  its  pliancy  wlien  immersed  in  hot  water.  Necks  of 
children's  sucking  bottles  are  thus  made. 

IVORY  BLACK  {Noir  cTivoire,  Fr.  ;  Kohle  vo7i  El/enbein,  Germ.)  is  prepared 
from  ivory  dust,  by  calcination  in  the  very  same  way  as  is  described  undfer  Bonk 
Black. 

The  calcined  matter  being  ground  and  levigated  on  a  porphyry  slab  affords  a  beau- 
tiful velvety  black,  much  used  in  copperplate  printing.  Ivory  black  may  be  prepared 
upon  the  small  scale  by  a  well  regulated  ignition  of  the  ivory  dust  in  a  covered 
crucible. 


END    OF   THE    FIRST    VOLUME. 


1-i 


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BIBLIOGRAPHIC  IRREGULARITIES 


MAIN  ENTRY:    Ure.  Andrew 


A  dictionary  of  arts.  manufactures,..V.  2 


Bibliographic  irregularities  in  the  Original  Document: 

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TRACKING*:  MSH04704 


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UrS 


mt^fCttp0fBrttif0rk 


LIBRARY 


School  of  Business 


Given  by 


I 


/ 


DICTIONARY 


or 


AETS,    MANUFACTURES, 


AITD 


MINES: 


OONTAININa 


A  CLEAR  EXPOSITION"  OF  THEIR  PRINCIPLES  AND  PRACTICE. 


BT 


ANDEEW  URE,  M.D., 

F.B.8.  M.G.8.  M.A.8.  LOND.  ;   M.  AOAD.  N.8.  PHILAD. ;   8.  PH.  SOO.  N.  OEBM. 

HANOV. ;    MULH.  ETC.  ETC. 


•     .     J 


IILUSTEATEO-i^raB-irfiAPLr  SIXTEEJf  HUHI/RED  ENGRAVINGS  ON  WOOD. 


(    1  i  »     •    « .1 


A 


»    1  \  *     t    «    . 


«     •     • 

«       * 


REPRINTED  ENTIRE  FROM  THE  LAST 


CORRECTED  AND  GREATLY  ENLARGED  ENGLISH  EDITION. 


IN  TWO  VOLUMES.- VOL.  H. 


D. 


NEW-YORK : 
APPLETON    &    COMPANY, 


846    A    348    BROADWAY. 
M.DCCC.LIV. 


/ 


* 


DICTIONARY 


or 


t »  >■     •     .    •      t 


<■      • « 
•  •     * 


*•  •♦       ■*    %    0    ^  t  ' 


•  • 


•         *  • 


^     »        '       •       •  1 

•     t       •#  »      •       •  •  * 


u 


•  X 


ARTS,  MANUFACTURES,  AND  MINES. 


K. 

KALL  The  Arabs  gave  this  name  to  an  annual  plant  which  grows  near  the  sea- 
shore ;  now  known  under  the  name  of  salnola  soda,  and  from  whose  ashes  they  extracted 
a  substance  which  they  called  alkali,  for  making  soap.  The  term  kali  is  used  by  Ger- 
man chemists  to  denote  caustic  potash;  and  kalium,  its  metallic  basis;  instead  of  our 
potassa  and  potassium,  of  preposterous  pedigree,  being  derived  from  the  words  pot 
ashes,  that  is  ashes  prepared  in  a  pot. 

KAOLIN,  (Terre  d  porcelaine,  Fr. ;  Porzellanerde,  Germ.),  is  the  name  given  by  the 
Chmese  to  the  fine  white  clay  with  which  they  fabricate  the  biscuit  of  their  porcelains. 
»ee  Clay.     Berthier's  analyses  of  two  porcelain  earths  are  as  follows : 


Analysea. 


Silica  -  -  - 
Alumina  -  - 
Lime  -  -  - 
Oxide  of  iron 
Potass  -  -  - 
Water  -    -    - 


From  Passan. 


From  St  Yrieux. 


45-06 

32-00 

0-74 

0-90 

18-0 


96-7 


46-8 
87-3 


2-5 
130 


99-6 


i5^?^%  *  "^^^^  of  amber,  of  Arabic  origin,  in  use  upon  the  Continent 
KELP ;  ( Varec,  Fr. ;  Wareck,  Germ.),  is  the  crude  alkaline  matter  produced  bv  in- 
cmerating  various  species  of  fuci  or  sea-weed.  They  are  cut  with  sickles  from  the 
rocks  m  the  summer  season,  dried  and  then  burned,  with  much  stirring  of  the  pastv 
ash.  I  have  analyzed  many  specimens  of  kelp,  and  found  the  quantity  of  soluble  mat- 
ter in  100  parts  of  the  best  to  be  from  53  to  62,  while  the  insoluble  was  from  47  to  38. 
The  soluble  consisted  of — 

Sulphate  of  soda  -  -  -  .  . 

Soda  in  carbonate  and  sulphuret 

Muriate  of  soda  and  potash  -  .  . 

The  Insoluble  matter  consisted  of- 

Carbonate  of  lime  -  -  -  . 

Silica         -----. 
Alumina  tinged  with  iron  oxide  - 
Sulphate  of  lime  -  -  -  .  . 

Sulphur  and  loss  -  -  -  .  . 

m.    c    4.    e^x,  .  100-0  lOO'O 

T  1     ®^  ci     ^^^'^^s®  fPecimens  was  from  Heiskcr,  the  second  from  Rona,  both  in  the 
Isle  ^^Skj^,  upon  the  property  of  Lord  Macdonald.     From  these  and  many  other 

/ 


8-0 

19-0 

8-6 

5-5 

36-6 

37-5 

63-0 

62-0 

24-0 

10-0 

8-0 

0-0 

9-0 

10-0 

0-0 

9-5 

6-0 

8-6 

^  KERMES. 

analyses  which  I  have  made  it  appears  that  kelp  is  a  substance  of  verv  variahlp  onm 
position  and  hence  it  was  very  apt  to  produce  anomalous  results,  whTn  empW^^^^^^^ 
the  chief  alkalme  flux  of  crown  glass,  which  it  was  for  a  very  long  peTod      The 
f^  l^^^cvfo»us  and  fucus  nodoms  are  reckoned  to  afford  the  best  kelp,  by  incinera- 

^r  'fi  .\  *^u  '^^""T  ^''^^  ^  ^'^*^'*  P^^^'^^^  "^^'^  *h«y  ^re  of  two  or  three  yeare 
grpwtli,  than  when  cut  younger.  The  varec,  made  on  the  shores  of  NoLandv^cor 
tarn  almost  no  carbonate  of  soda,  but  much  sulphate  of  soda  and  potas^ome  hvD^ 
sulphate  of  potash,  choride  of  sodium,  iodide  of  potassium,  and  chloride  of  pSLiuL 
the  average  composition  of  the  soluble  salts  being,  according  to  KGay^Lu^c^e 
of  chloride  of  sodium  25  of  chloride  of  potassium,^  and  a  little  sulphatJ  of  notVh 
The  very  low  pri^  at  which  soda  ash,  the  dry  crude  carbonate  froni  the  decomposil 
tion  of  sea  salt  is  now  sold  has  nearly  superseded  the  use  of  kelp,  and  reSd  ?te 
7ZtCr  ^    ^^^  ^^Profitable-a  great  misfortune  to  the  Ilig&ands  and  IsL„d1 

Kfc:RMKS.  There  are  two  substances  so  caUed,  of  totaUy  different  natures.  Kermes 
mineral  IS  merely  a  factitious  sulphurel  of  antimony  in  a  state  of  impalpable  comminution, 
prepared  m  the  moist  way.  Its  minute  examination  belongs  to  pharmaceutical  chemistry! 
It  may  be  obtained  perfectly  pure,  by  diluting  the  proto-chloride  of  antimony  with  solution 
of  tartaric  acid,  and  precipitating  the  metal  with  sulphureted  hydrogen  ;  or  by  exposing 
the  finely  levi-ated  native  sulphuret  to  a  boiling  solution  of  carbonate  of  potash  for  somS 
time,  and  filtering  the  liquor  while  boiling  hot.  The  kermes  faUs  down  in  a  brown-red 
powder,  as  the  hquor  cools. 

Kermes-grains,  alkermes,  are  the  dried  bodies  of  the  female  insects  of  the  species  coccus 
tlicu,  which  hves  upon  the  leaves  of  the  qiiercus  ilex  (pricklv  oak).  The  word  kermea 
is  Arabic,  signifies  httle  worm.  In  the  middle  ages,  this  dye  stuff  was  therefore  caUed 
vermiculus  m  Latin,  and  vermilion  m  French.  It  is  curious  to  consider  how  the  name 
vermilion  has  been  since  transferred  to  red  sulphuret  of  mercury. 

Kermes  has  been  known  in  the  East  since  the  days  of  Moses ;  it  has  been  employed 
from  time  immemorial  in  India  to  dye  silk;  and  was  used  also  by  the  ancient  Greek 
and  Roman  dyers.  Plmy  speaks  of  it  under  the  name  of  coccigranum,  and  says  that 
there  grew  upon  the  oak  in  Africa,  Sicily,  &e.  a  smaU  excrescence  like  a  bud,  called 
^sculmm;  that  the  Spaniards  paid  with  these  grains,  half  of  their  tribute  to  the 
Romans ;  that  those  produced  in  Sicily  were  the  worst ;  that  they  served  to  dye  purple  • 
and  that  those  from  the  neighborhood  of  Emerita  in  Lusitania  (Portugal)  were  the 
best. 

In  Germany,  during  the  ninth,  twelfth,  thirteenth,  and  fourteenth  centuries,  the  rural 
serfs  were  bound  to  deliver  annually  to  the  convents,  a  certain  quantity  of  kermes  the 
coccus  polomcus,  among  the  other  products  of  husbandry.  It  was  coUected  from  the  trees 
upon  Saint  John's  day,  between  eleven  o'clock  and  noon,  with  religious  ceremonies,  and 
was  therefore  called  Johannisblut  (Saint  John's  blood),  as  also  German  cochineal.  At  the 
above  period,  a  great  deal  of  the  German  kermes  was  consumed  in  Venice,  for  dyeing  the 
scariet  to  which  that  city  gives  its  name.  After  the  discovery  of  America,  cochineal  hav- 
mg  been  introduced,  began  to  supersede  kermes  for  all  brilliant  red  dyes. 

The  principal  varieties  of  kermes  are  the  coccus  quercusy  the  coccus  poUmicus.  the  coccus 
jragarice,  and  the  coccus  uva  ursi. 

The  coccus  quercus  insect  lives  in  the  south  of  Europe  upon  the  kermes  oak.  The 
female  has  no  wings,  is  of  the  size  of  a  smaU  pea,  of  a  brownish-red  color,  and  is  covered 
with  a  whitish  dust.  From  the  middle  of  May  to  the  middle  of  June  the  eggs  are  collected, 
and  exposed  to  the  vapor  of  vinegar,  to  prevent  their  incubation.  A  portion  of  eggs 
IS  left  upon  the  tree  for  the  maintenance  of  the  brood.  In  the  department  of  the  Bouches- 
du-Rhone,  one  half  of  the  kermes  crop  is  dried.  It  amounts  annually  to  about  60  quintals 
or  cwts.,  and  is  warehoused  at  Avignon. 

The  kermes  of  Poland,  or  coccus  polonicus,  is  found  upon  the  roots  of  the  scleranthus 
perennis  and  the  scleranthus  annuus,  in  sandy  soils  of  that  country  and  the  Ukraine.  This 
species  has  the  same  properties  as  the  preceding ;  one  pound  of  it,  according  to  Wolfe, 
being  capable  of  dyeing  10  pounds  of  wool ;  but  Hermstaedt  could  not  obtain  a  fine 
color,  although  he  employed  5  times  as  much  of  it  as  of  cochineal.  The  Turks,  Arme. 
mans,  and  Cossacks,  dye  with  kermes  their  morocco  leather,  cloth,  silk,  as  well  as  tne 
manes  and  tails  of  their  horses. 

The  kermes  called  coccus  fragaria,  is  found  principally  in  Siberia,  upon  the  root  of  the 
common  strawberry. 

The  coccus  uva  ursi  is  twice  the  size  of  the  PoUsh  kermes,  and  dyes  with  alum  a  fim- 
red.    It  occurs  m  Russia. 

Kermes  is  found  not  only  upon  the  lycopodium  complanatum  in  the  Ukraine,  but  upon 
a  great  many  other  plants. 

Good  kermes  is  plump,  of  a  deep  red  color,  of  an  agreeable  smell,  and  a  roush  and 
pungent  taste.  Its  coloring  matter  is  soluble  in  water  and  alcohol ;  it  becomes  yellowish 
or  brownish  with  acids,  and  violet  or  crimson  with  alkalis.     Sulphate  of  iron  blackens  iU 


I 


KOUMISS.  • 

"With  alum  it  dyes  a  blood-red ;  with  copperas  an  agat«  ip^? »  "with  copperas  and  tartar, 
a  lively  gray ;  with  sulphate  of  copper  and  tartar,  an  olrve  green ;  with  tartar  and  salt 
of  tin,  a  lively  cinnamon  yellow ;  with  more  alum  and  tartar,  a  lilach ;  with  sulphate  of 
zinc  and  tartar,  a  violet.  Scarlet  and  crimson  dyed  with  kermes,  were  called  grain  colors  ; 
and  they  are  reckoned  to  be  more  durable  than  those  of  cochineal,  as  is  proved  by  the  bril- 
liancy of  the  old  Brussels  tapestry. 

Hellot  says  that  previous  to  dyeing  in  the  kermes  bath,  he  threw  a  handful  of  wool  into 
it,  in  order  to  extract  a  blackish  matter,  which  would  have  tarnished  the  color.  The  red 
caps  for  the  Levant  are  dyed  at  Orleans  with  equal  parts  of  kermes  and  madder  j  and  oc- 
casionally with  the  addition  of  some  Brazil  wood. 

Cochineal  and  lac-dye  have  now  nearly  superseded  the  use  of  kermes  as  a  tinctorial 
si^bstance,  in  England. 

KILLAS  is  the  name  by  which  clay-slate  is  known  among  the  Comish  miners. 

KILN  (Four,  Fr. ;  Of  en.  Germ.)  is  the  name  given  to  various  forms  of  furnaces 
and  stoves,  by  which  an  attempered  heat  may  be  applied  to  bodies ;  thus  there  are  brick- 
kilns, hpp-kilns,  lime-kilns,  malt-kins,  and  pottery-kilns.  Hop  and  malt-kilns,  being 
designed  merely  to  expel  the  moisture  of  the  vegetable  matter,  may  be  constructed  in 
the  same  way.  See  Brick,  Limestone,  Malt,  and  Pottery,  for  a  description  of  their 
respective  kilns. 

KINIC  ACID ;  a  peculiar  acid  extracted  by  Vauquelin  from  cinchona. 

KINO  is  an  extractive  matter  obtained  from  the  nauclea  gambir,  a  shrub  which 
grows  at  Bancoul  and  Sumatra,  but  principally  in  Prince  of  Wales'  island.  It  is  of  a 
reddish-brown  color,  has  a  bitter  styptic  taste,  and  consists  chiefly  of  tannin.  It  is 
used  only  as  an  astringent  in  medicine.  Kino  is  often  called  a  gum,  but  most  im- 
properly. 

KIRSCHWASSER  is  an  alcoholic  liquor  obtained  by  fermenting  and  distilling  bruised 
cherries,  called  kirsrhen  in  German.  The  cherry  usually  employed  in  Switzerland  and 
Germany  is  a  kind  of  morello,  which  on  maturation  becomes  black,  and  has  a  kernel 
very  large  in  proportion  to  its  pulp.  When  ripe,  the  fruit  being  made  to  fall  by  switching 
the  trees,  is  gathered  by  children,  thrown  promiscuously,  unripe,  ripe,  and  rotten  into 
tubs,  and  crushed  either  by  hand,  or  with  a  wooden  beater.  The  mashed  materials  are 
set  to  ferment,  and  whenever  this  process  is  complete,  ^he  whole  is  transferred  to  an  old 
still  covered  with  verdigris,  and  the  spirit  is  run  off  in  the  rudest  manner  possible,  by 
placing  the  pot  over  the  common  fire-place. 

The  fermented  mash  is  usually  mouldy  before  it  is  put  into  the  alembic,  the  capital 
of  which  is  luted  on  with  a  mixture  of  mud  and  dang.  The  liquor  has  accordingly, 
for  the  most  part,  a  rank  smell,  and  is  most  dangerous  to  health,  not  only  from  its  own 
crude  essential  oil,  but  from  the  prussic  acid,  derived  from  the  distillation  of  the  cherry- 
stones. 

There  is  a  superior  kind  of  kirschwasser  made  in  the  Black  Forest,  prepared  with  fewer 
kernels,  from  choice  fruit,  properly  pressed,  fermented,  and  distilled. 

KNOPPERN  are  excrescences  produced  by  the  puncture  of  an  insect  upon  the 
flower-cups  of  several  species  of  oak.  They  are  compressed  or  flat,  irregularly  pointed, 
generally  prickly  and  hard ;  brown  when  ripe.  They  abound  in  Styria,  Croatia,  Sclavonia, 
and  Natolia ;  those  from  the  latter  country  being  the  best.  They  contain  a  great  deal 
of  tannin,  are  much  employed  in  Austria  for  tanning,  and  in  Germany  for  dyeing  fawn, 
gray,  and  black.  Wool,  with  a  mordant  of  sulphate  of  zinc,  takes  a  grayish  nankeen 
color.     See  Galls. 

KOUMISS  is  the  name  of  a  liquor  which  the  Calmucs  make  by  fermenting  mare's 
milk,  and  from  which  they  distil  a  favorite  intoxicating  spirit,  called  rack  or  racky. 
Cow's  milk  is  said  to  produce  only  one  third  as  much  spirit,  from  its  containing  probably 
less  saccharine  matter. 

The  milk  is  kept  in  bottles  made  of  hides,  till  it  becomes  sour,  is  shaken  till  it  casts 
up  its  cream,  and  is  then  set  aside  in  earthen  vessels  in  a  warm  place  to  ferment,  no 
yeast  being  required,  though  sometimes  a  little  old  koumiss  is  added.  21  pounds  of  milk 
put  into  the  still  afford  14  ounces  of  low  wines,  from  which  6  ounces  of  pretty  strong 
alcohol,  of  an  unpleasant  flavor,  are  obtained  by  rectification. 


/ 


LABOR-SAVING  MACHINES. 


LABDANUM  or  Ladanum,  is  an  unctuous  resin,  of  an  agreeable  odor,  found  be- 
smearing the  leaves  and  twigs  of  the  cystun  creticus,  a  plant  which  grows  in  the  island 
of  Candia,  and  in  Syria.  It  is  naturally  a  dark-brown  soft  substance,  but  it  hardens 
on  keeping.  Its  specific  gravity  is  1  -186.  It  has  a  bitter  taste.  Its  chief  use  is  in  sur- 
gery for  making  plasters. 

LABOR-SAVING  MACHINES  ix  the  Great  Exhibition. — Printing  and  numbering 
Cards. — It  will  be  remembered,  that  in  the  early  da3S  of  railway  travelling,  the  ticket 
system  then  in  vogue  at  the  various  stations  was  a  positive  nuisance;  as  every  ticket 

before  it  was  delivered  to  a  passenger  had  to  be  stamped,  and  torn  out  of  a  book, 

thus  causing  the  loss  of  considerable  time  to  travellers  when  many  passengers  were 
congregated.  But  this  was  the  least  ovil;  for  the  railway  directors  had  little  or  no 
check  upon  their  servants,  and  therefrom  resulted  many  ingenious  and  successful 
frauds.  The  first  to  remedy  this  was  Mr.  Edmondson,  who  constructed  an  ingenious 
apparatus  for  printing  the  tickets  with  consecutive  numbei-s,  and  also  dating  the 
sanae.  This  gave  great  facilities  for  cheeking  the  accounts  of  the  station  clerks ;  but 
owing  to  the  imperfect  manner  of  inking,  consequent  on  the  construction  of  the  ap- 
paratus, the  friction  to  which  the  tickets  were  exposed,  before  they  were  delivered 
up,  in  a  great  measure  obliterated  the  printing,  and  occasionally  rendered  them  quite 
illegible.  By  Messrs.  Church  and  Goddard's  machine  for  printing,  numbering,  cut- 
ting, counting,  and  packing  railway  ticket.'*,  this  difficulty  also  is  removed,  and  great 
speed  is  attained  in  manufacturing  the  tickets,  as  the  several  operations  which  we 
have  enumerated  are  simultaneously  performed.  Pasteboard  cut  into  strips  by  means 
of  rollers,  as  above  explained,  is  fed  mto  the  machine,  by  being  laid  in  a  trough,  and 
brought  under  the  prongs  of  a  fork  (working  with  an  intermitting  movement),  which 
pushes  the  strips  successively  forward  between  the  first  pair  of  a  series  of  guide  or 
carrying  rollers.  There  are  four  pairs  of  rollers,  placed  so  as  to  conduct  the  strip 
through  the  machine  in  a  horizontal  line ;  and  an  intermittent  movement  is  given 
them  for  the  purpose  of  carrying  the  strips  forward  a  short  distance  at  intervals. 
The  standards  of  the  machine  carry,  at  the  top,  a  block,  termed  the  "  platten,"  as  it  acts 
the  part  of  the  press  head  in  the  common  printing  machine, — ^portions  of  it  projecting 
downwards  between  the  upper  rollers  of  the  fii  st  and  second,  and  second  and  third, 
pail's  of  carrying  rollers,  nearly  to  the  horizontal  plane,  in  which  the  pasteboard  lies, 
so  as  to  sustain  it  at  those  pomts  while  it  receives  the  pressure  of  the  printing  types 
and  numbering  discs,  hereafter  referred  to.  The  types  to  designate  the  nature  of  the 
ticket,  as  "Birmingham,  First  class,"  are  secured  in  a  "chase,"  upon  a  metal  plate  or 
table,  which  also  carries  the  numbering  discs  for  imprinting  the  figures  upon  the 
cards ;  and  the  table  by  a  cam  action  is  alternately  raised,  to  bring  the  types  and  num- 
bering discs  in  contact  with  the  pasteboard,  and  then  lowered  into  a  suitable  position 
to  admit  of  an  inking  roller  moving  over  the  types  and  numbering  discs,  and  applying 
•ink  thereto.  The  table  likewise  carries  at  one  end  a  knife,  which  acts  in  conjunction 
with  a  knife-edge  projecting  downwards  from  the  fixed  head  of  the  machine,  and 
thereby  gives  the  cross  cut  to  the  strips  between  the  third  and  fourth  pairs  of  carry- 
ing rollers, — thus  severing  each  into  a  given  number  of  tickets.  The  strip  of  paste- 
board which  is  fed  into  the  machine  stops  on  arriving  at  the  second  pair  of  carrying 
rollers ;  and,  on  the  ascent  of  the  printing-table,  the  tj'pes  print  on  that  portion  which 
is  between  the  first  and  second  pairs  of  rollers.  The  strip  then  passes  on  to  the  third 
pair  of  rollers,  where  it  stops ;  and,  on  the  table  again  ascending,  the  numbering  discs 
imprint  the  proper  number  upon  the  pasteboard  between  the  second  and  third  pairs ; 
the  type,  in  the  meanwhile,  printing  what  is  to  be  the  next  following  ticket.  On  the 
next  ascent  of  the  table,  the  strip  has  advanced  to  the  fourth  pair  of  rollers ;  and  the 
knives  being  now  brought  into  contact,  the  printed  and  numbered  portion  of  the  strip 
is  severed.  The  now  completed  ticket  is  lastly  delivered  by  the  fourth  pair  of  rollers 
into  a  hollow  guide  piece,  and  conducted  to  a  box  below,  provided  with  a  piston,  which, 
to  facilitate  the  packing  of  the  tickets  in  the  box,  can  be  adjusted  to  any  height  to  re- 
ceive the  tickets  as  they  fall.  To  avoid  the  necessity  of  having  to  count  the  tickets  after 
they  are  taken  from  the  receiving  box,  a  counting  apparatus,  connected  with  the  work- 
ing parts  of  the  machine,  is  made  to  strike  a  bell  on  the  completion  of  every  hundred  or 
more  tickets,  so  as  to  warn  the  attendant  to  remove  them  from  the  box.  The  inking 
apparatus  is  assimilated  in  character  to  self-acting  inkers  in  ordinary  printing  presses ; 
and  the  numbering  discs  are  worked  in  a  manner  very  similar  to  those  for  paging  books. 
A  simple  arrangement  of  apparatus  for  printing  and  numbering  cards  was  exhibited  by 
Messrs.  Harrild  &  Sons.  The  types  are  fixed  in  a  metal  frame,  which  also  carries  the 
numbering  discs.     This  frame  is  mounted  on  a  rocking  shaft,  and  is  furnished  with  a 


W 


LABOR-SAVING  MACHINES.  6 

handle,  whereby  it  is  rocked  to  bring  down  the  types  and  discs  upon  the  card,  to  pro- 
duce the  impression.  When  the  frame  is  raised  again,  the  units  disc  is  moved  forward 
one  figure,  and  the  types  are  inked  by  a  small  roller,  which  takes  its  supply  of  ink  from 
an  inking  table,  that  forms  the  top  of  the  frame.  This  is  a  useful  description  of  ma- 
chine ;  but  the  specimen  in  the  Exhibition  does  not  appear  to  have  been  properly  ad- 
justed, as  the  figures  of  the  numbering  discs  have  a  tendency  to  cut  through  the  card. 

M.  Baranowski,  of  Paris,  exhibits  a  machine  for  printing  and  numbering  tickets, 
and  also  indicating  the  number  printed.  The  types  and  numbering  discs  are  carried 
by  a  horizontal  rotating  shaft,  upon  which,  near  each  end  thereof  is  a  metal  disc; 
and  upon  the  periphery  of  these  discs,  a  metal  frame  is  affixed,  which  carries  the  types 
and  numbering  discs,  and  corresponds  in  curvature  with  the  edge  of  the  discs.  The 
types  for  printmg  the  inscription  upon  the  ticket  are  arranged  at  right  angles  to  the 
length  of  the  shaft,  which  position  admits  of  some  lines  of  the  inscription  being  printed 
in  one  color,  and  the  remainder  in  another  color.  In  the  type  frame  a  slot  or  opening 
is  formed  lengthwise  of  the  shaft ;  and  behind  this  opening  are  three  numbering  discs, 
and  three  discs  for  indicating  the  quantity  of  tickets  numbered, — all  standing  in  the 
same  row.  The  numbering  discs  are  made  with  raised  figures,  which  project  through 
the  slot^  in  order  to  print  the  number  upon  the  ticket;  and  on  the  peripheries  of  the 
registering  discs  (which  move  simultaneously  with  their  corresponding  numbering 
discs),  the  figures  are  engraved.  The  tickets  to  be  printed  and  numbered  are  placed 
in  a  rectangular  box  or  receiver,  having  at  the  bottom  a  flat  sliding  piece,  which  has 
a  reciprocating  motion  for  the  purpose  of  pushing  the  lowest  ticket  out  of  the  box, 
through  an  opening  in  the  front  side  thereof  beneath  an  elastic  pressing-roller  of  In- 
dia-rubber ;  the  type  frame  (with  the  types  and  figures  properly  inked),  is  at  the  same 
time  brought,  by  the  rotation  of  its  shaft,  into  contact  with  the  ticket  beneath  the 
pressing-roller,  and  as  it  continues  its  motion,  it  causes  the  ticket  to  move  forward 
beneath  the  pressing-roller,  and  to  be  properly  printed  and  numbered.  The  ticket 
then  falls  from  the  machine ;  and  the  type  frame,  carried  on  by  the  revolution  of  the 
shaft,  brings  that  number  on  the  registering  discs,  which  corresponds  with  the  num- 
ber printed  on  the  ticket,  under  a  small  opening  in  the  case,  covered  with  glass; 
whereby  the  number  of  tickets  printed  will  be  indicated. 

Backing  Books. — Not  altogether  foreign  to  the  subject  of  printing  is  the  contribution 
of  Mr.  C.  Star,  of  New- York,  United  States,  who  exhibits  two  machines  for  booksellers' 
use, — the  one  being  employed  for  backing, and  the  other  for  finishing  the  backs  of  books. 
The  two  machines  are  similar  to  each  other,  as  regards  the  subordinate  parts,  but  diflFer 
in  some  other  respects.  In  the  backing  machine,  the  stitched  sheets,  forming  the  book, 
are  fixed  in  a  pair  of  iron  clumps,  somewhat  larger  then  the  book  itself.  The  clumps  are 
mounted  on  horizontal  pivots,  and  furnished  with  a  weighted  lever,  which  gives  them  a 
tendency  to  move  out  of  the  vertical  line,  and  thereby  bring  the  back  of  the  book,  which 
stands  up  above  the  edges  of  the  clumps,  under  the  action  of  a  smooth  metal  roller.  This 
roller  turns  in  bearings  which  are  capable  of  sliding  vertically  in  the  framing  of  the  ma- 
chine :  and  the  bearings  are  pressed  upon  by  two  weighted  levers,  when  the  machine  is 
in  use,  so  as  to  cause  the  roller  to  bear  down  forcibly  upon  the  book.  While  the  roller 
is  in  this  position,  the  weighted  lever  of  the  clumps  causes  the  book  to  oscillate,  and 
thus  the  rounding  of  the  back  is  etfected.  The  movemeni;  of  the  clumps  under  the 
roller  is  regulated  by  the  workman  through  a  foot  treadle,  connected  with  the  lever 
in  the  machine  for  finishing  the  backs;  the  roller  is  engraved  with  any  suitable  de- 
sign ;  and  the  cross  piece  which  supports  its  bearings,  is  made  hollow,  and  is  heated  bv 
steam,  for  the  purpose  of  communicating  heat  to  the  roller.  Motion  in  this  case  is 
given  to  the  clump  by  a  winch-handle,  instead  of  the  weighted  lever,  and  the  pattern 
on  the  roller  is  thereby  embossed  upon  the  back  of  the  book. — Newton's  Journal. 

Washing  and  Mangling. — ^The  British  portion  of  the  Great  Exhibition  contained  nu- 
merous examples  of  the  application  of  machinery  to  economize  labor  in  the  processes 
of  washing,  wringing,  and  mangling.  The  washing  machines  may  be  divided  into 
three  classes,  viz.,  first,  those  which  have  a  rotary  action  ;  secondly,  those  wherein 
vibrating  beaters  are  employed ;  and  thirdly,  those  in  which  vertical  beaters  are 
ultimately  raised  and  permitted  to  fall  upon  the  clothes. 

In  the  first  class,  Mr.  V.  Price,  of  Wardour  Street,  Soho,  has  a  simple  machine,  con- 
sisting of  a  cylinder  or  drum,  to  contain  the  clothes,  revolving  horizontally  in  a  close 
wooden  vessel,  or  outer  case,  which  holds  the  soap-suds.  The  drum  is  made  with  solid 
ends;  but  (in  order  that  the  soap-suds  may  have  free  access  to  the  clothes),  the 
periphery  or  body  thereof  is  composed  of  wooden  bars  or  spokes,  extending  from  one 
end  to  the  other,  with  a  space  somewhat  greater  than  the  width  of  a  bar  between  the 
adjacent  bars,  so  as  to  resemble  what  is  known  to  engineers  as  a  "lantern  drum."  Tiie 
clothes  are  introduced  by  opening  a  door  in  the  side  of  the  drum ;  and  on  rotary  mo- 
tion being  given  to  the  drum  by  a  handle,  the  soap-suds  will  be  caused  to  act  upon 
and  thoroughly  cleanse  the  clothes.  y 


6  LABOR-SAVING  MACHINES. 

Mr.  J.  Adaraa,  of  Selby,  exhibited  a  machiae,  in  wliich  the  articles  to  be  washed 
were  placed  in  a  perforated  wooden  barrel  or  octagonal  vessel,  rotating  hoiizontilly 
in  an  outer  case.  Above  the  case  two  wooden  rollers  are  mounted,  one  over  the  other  • 
and  the  clothes,  when  sufficiently  washed,  are  passed  between  such  rollers,  so  sis  to 
squeeze  out  the  soap-suds,  instread  of  wringing  the  clothes  by  hand.  These  rollers 
may  be  subsequently  used  for  mangling  the  clothes. 

Another  rotary  machine,  exhibited  by  Mr.  Pearson,  of  Leeds,  consists  of  a  tub  or 
wooden  vessel,  in  which  the  clothes  are  thrown  ;  and  the  requisite  agitation  for  wash- 
ing or  discharging  the  dirt  is  effected  by  means  of  an  upright  beater,  which  rotates  in 
the  tub  in  the  same  manner  as  the  "  dasher  "  of  an  upright  rotary  churn.  This  appara- 
tus is  also  provided  with  a  pair  of  rollers  for  wringing  and  mangling  the  clothes. 

The  next  machines  of  the  rotary  class  which  we  shall  notice,  are  those  of  Messrs. 
Manloye,  Alliott,  <fe  Seyrig,  of  Lenton  Works,  Nottingham.  In  these  machines  the 
operations  of  washing  and  drying  are  effected  by  centrifugal  force ;  that  is  on  the 
mass-trundling  principle.  The  utility  of  this  construction  of  machines,  both  for  wash- 
ing and  drying  fabrics,  is  uncjuestionable ;  and,  under  slight  modifications,  they  are 
extensively  used  for  the  refinmg  of  sugar.  Each  machine  may  be  described  as  con- 
sisting simply  of  a  drum,  having  its  periphery  formed  of  wires,  and  being  fixed  to  a 
verticid  shaft,  which  rotates  in  the  centre  of  a  cylindrical  metal  case.  The  goods  to  be 
washed  are  put  into  the  drum,  and  water  is  supplied  thereto  through  a  hollow  central 
shaft.  On  rapidly  rotating  the  drum,  the  water  is  caused,  by  centrifugal  force,  to  pass 
outwards  through  the  goods,  and  through  the  wire  periphery  of  the  drum,  into  the 
outer  case,  from  which  it  is  conducted  away.  To  dry  washed,  or  wet  goods,  they  are 
placed  in  the  drum  without  access  of  water,  and  by  the  rapid  rotation  of  the  same  the 
moisture  in  the  clothes  is  discharged, — the  time  required  for  drying  in  no  case  ex- 
ceeding five  minutes.  These  machines  are  suitable  for  washing  and  rinsing  dyed 
goods ;  but  they  are  not  applicable  to  the  v^ashing  of  thoroughly  dirty  clothes ;  they  may^ 
however,  be  used  for  rinsing  the  same  after  they  have  been  washed  by  other  means.' 

Mr.  Robinson  exhibited  a  machine  for  drying  wet  clothes,  which  acts  upon  the  same 
principle  as  the  above.  The  drum  that  receives  the  wet  clothes  is  formed  of  round  iron 
bars,  with  spaces  between  them,  and  mounted  on  a  horizontal  shaft.  By  means  of  a 
row  of  bars  the  drum  is  divided  into  two  compartments,  which  receive  the  goods  through 
a  door  formed  in  the  drum-ends;  and  the  whole  is  enclosed  in  a  circular  iron  case, which 
is  open  below.  The  goods  having  been  put  into  the  drum,  it  is  caused  to  revolve  with 
great  rapidity,  and  the  moisture  is  expressed  from  the  goods  by  centrifugal  force,  and 
escapes  through  the  opening  in  the  bottom  of  the  case.     See  HYDRo-EXTKAcrroB. 

Another  rotary  washing  machine  is  exhibited  by  Mr.  Nunn.  It  consists  of  a  large 
drum,  which  is  mounted  upon  a  horizontal  shaft,  within  a  closed  vessel  or  case,  and  car- 
ries numerous  small  rollers  all  round  its  periphery,  such  rollers  being  capable  of  turning 
freely  and  independentlj  of  each  other,  and  their  axes  being  parallel  to  the  axis  of  the 
drum.  The  case  contains  water  or  soap-suds,  in  which  the  drum  is  immersed  to  the 
extent  of  about  one-fifth  or  one-sixth  of  its  diameter;  the  clothes  are  kept  in  contact  with 
the  drum,  as  it  revolves  by  several  endless  tapes;  and  as  the  clothes  successively  ar- 
rive at  the  upper  part  of  the  drum,  they  are  acted  upon  by  five  fluted  rollers  above  it. 

Mr.  Nunn  contributed  another  machine,  which  appears  to  be  designed  for  rinsing 
and  wringing  only.  Two  fluted  rollers,  one  above  the  other,  are  mounted  in  the  up- 
per part  of  a  wooden  vessel  or  trough ;  an  endless  band  passes  over  the  lower  roller, 
for  the  purpose  of  conducting  the  clothes  between  the  fluted  rollers;  and  there  is  ano- 
ther endless  band  below,  immersed  in  the  water  which  the  vessel  contains,  and  pass- 
ing over  a  roller  at  each  end  ef  the  vessel,  its  apparent  use  being  to  receive  the  clothes 
as  they  fall  from  the  first  band,  and  bring  them  again  to  that  end  of  the  vessel  where 
they  were  introduced. 

Machines  of  the  second  class,  viz.  those  wherein  vibrating  beaters  are  employed,  were 
exhibited  by  Messrs.  Fryer,  Tasker,  Mai-sden  and  Reid.  In  Mr.  Fryer's  machines,  an 
upright  board  or  beater,  having  vertical  slots  or  openings  in  it,  is  caused  to  vibrate 
or  swing  to  and  fro  in  a  segmental  vessel  (containing  the  clothes  to  be  washed  and  a 
suitable  quantity  of  soap-suds),  and  beat  the  clothes  against  the  side  of  the  vessel 
until  they  are  thoroughly  cleansed. 

In  Mr.  Tasker's  machine,  a  beater,  with  vertical  slots  or  openings  in  it,  vibrates  in 
A  trough  or  vessel  having  a  series  of  projecting  ribs  at  each  side,  corresponding  with 
the  openings  in  the  beater. 

The  beater  in  Mr.  Marsden's  machine  has  a  projecting  rib  affixed  to  it  on  each  side, 
between  the  several  slots  or  openings ;  and  at  each  side  of  the  segmental  trough  or 
vessel,  in  which  the  beater  works,  there  is  hinged  a  flap  or  false  side,  with  numerous 
horizontal  slots  or  openings  in  it. 

The  three  last-mentioned  machines  are  all  provided  with  rollers  for  wringing  and 
mangling  the  clothes. 


LABOR-SAVING  MACHINES. 


T 


^ 


Mr.  Reid's  machine  consists  of  a  large  square  box,  the  bottom  of  which  takes  the 
form  of  the  segment  described  by  a  vibrating  beater  suspended  in  the  box.  The  ma- 
chine also  contains  a  "  wringer,  which  is  a  net  formed  into  a  bag,  having  an  opening 
at  the  side  for  the  introduction  of  the  wet  clothes ;  and  at  each  end  of  the  bag  there 
is  a  screw  bolt,  with  a  nut  upon  it,  by  one  of  which  the  bag  is  to  be  secured  to  the 
side  of  the  machine,  and  by  the  other  it  is  connected  to  a  crank,  which,  on  being 
actuated,  will  twist  the  bag,  and  thereby  express  the  water  from  the  clothes.  At  the 
back  of  the  machine  several  rollers  are  mounted  one  above  the  other,  for  the  purpose 
of  mangling  the  articles. 

Mr.  W.  Macalpine,  of  Hammersmith,  exhibited  a  machine  of  the  third  class,  con- 
structed with  ascending  and  descending  beatera  It  consists  oi  a  cylindrical  metal 
vessel,  which  is  fixed  upon  an  upright  axis,  and  is  caused  to  rotate  by  suitable  wheel- 
work  in  connection  with  a  steam-engine.  The  vessel  is  made  with  perforated  false 
bottom  and  sides,  so  as  to  form  a  hollow  casing,  into  which  steam  may  be  admitted, 
and  may  thence  pass  through  the  perforations,  and  act  upon  the  water  and  the  fabrics 
to  be  washed.  The  process  of  agitating  or  washing  the  fabrics  is  effected  by  nine  or 
ten  upright  beaters^  arranged  in  a  row  across  the  interior  of  the  vessel,  and  afternately 
elevated  and  permitted  to  fall  upon  the  fabrics. 

Messrs.  Wilkinson,  Stutterd,  Baker,  Moreton,  and  others,  exhibited  machines  for 
performing  the  operation  of  mangling  only ;  but  as  these,  whatever  their  respective 
merits,  cannot  be  said  to  be  new  applications  of  machinery  for  economizing  labor, 
they  do  not  properly  come  within  our  province. 

From  the  above  notice  it  will  be  seen  that  considerable  attention  has  been  given 
by  machine  makers  to  that  most  important  branch  of  domestic  economy — washing. 
There  is  not,  perhaps,  one  of  the  machines  above  described,  which  would  not  as  eff'ect- 
nally  cleanse  all  under-clothing  as  the  most  fastidious  could  desire ;  and  yet  we  still 
suflfer  our  clothes  to  be  tortured  by  the  rubbing  and  wringing  of  those  merciless  mo- 
dern amazons  who  preside  over  soap-suds,  and  allow  them  to  be  transformed  into  lint 
and  ribbons,  without  an  attempt  at  removing  the  annoyance ;  indeed,  so  inveterate  is 
prejudice,  that  the  washerwoman  may  yet  look  for  a  long  lease  of  her  profession,  as 
it  luckily  touches  upon  no  established  manufacture. 

While  on  the  subject  of  washing,  we  may  direct  attention  to  a  machine  exhibited  by 
Mr.  C.  Farrow,  of  Great  Tower  street,  for  washing  bottles.  In  this  machine  a  hori- 
zontal metal  spindle,  carrying  a  bottle  brush  at  each  end,  is  caused  to  revolve  by  being 
connected  with  a  treadle.  A  bottle  is  pushed  over  each  brush  by  the  operator,  who 
holds  the  bottles  one  in  each  hand,  whilst  by  means  of  his  foot  he  works  the  treadle 
and  causes  the  rotation  of  the  brushes. 

Knife-cleaning. — Specimens  of  those  very  useful  machines  which  have  lately  been 
introduced  for  cleaning  knives  and  forks  are  to  be  found  in  the  building,  and  demand 
some  notice.  Mr.  Kent's  machine  consists  of  a  box  or  case,  containing  a  couple  of 
wooden  discs,  fixed  near  to  each  other  upon  a  horizontal  iron  rod  or  spindle,  which 
passes  through  the  case,  and  is  caused  to  rotate  by  means  of  a  winch-handle.  Each 
disc  is,  for  about  three-fourths  of  the  area  of  its  inner  face,  covered  with  alternate 
rows  of  bristles  and  strips  of  leather ;  and  the  remaining  fourth  part  is  covered  with 
bristles  only.  The  knife-blades  to  be  cleaned  are  introduced  through  openings  in  the 
case,  between  the  rubbing  surfaces  of  the  discs ;  and  rotatory  motion  being  given  to 
the  discs  by  a  winch-handle,  the  knives  are  rapidly  cleaned  and  polished. 

The  machines  exhibited  by  Mr.  Masters  are  constructed  upon  the  same  plan  as  the 
above ;  but  the  rubbing  surface  of  each  disc  is  formed  of  strips  of  buff  leather,  with 
only  a  narrow  circle  of  bristles  around  the  edge  of  each  surface,  to  clean  the  shoulders 
of  the  knives ;  small  brushes  are  fixed  beneath  the  holes  in  the  case,  through  which 
the  blades  of  the  knives  are  inserted,  to  prevent  the  exit  of  dust  from  the  apparatus. 

Mr.  Price  exhibited  a  machine  for  cleaning  knives,  and  another  for  cleaning  forks. 
The  knife-cleaner  consists  of  a  horizontal  drum,  covered  with  pieces  of  leather  or  felt., 
and  fixed  within  another  drum  or  circular  framing,  lined  with  leather  or  felt  The 
knives  are  introduced  through  openings,  in  a  movable  circular  plate,  at  the  front  of 
the  outer  casing,  and  enter  between  the  surfaces  of  the  two  drums.  The  plate  is  fixed 
upon  a  horizontal  axis,  which  extends  through  the  case,  and  is  furnished  at  the  back 
with  a  handle ;  by  turning  which  the  disc  is  caused  to  rotate  and  carry  round  the 
long  rectangular  opening  in  the  side,  behind  which  two  brushes  are  fixecf  face  to  face. 
Between  these  brushes  the  prongs  of  the  forks  are  introduced,  and  the  handles  are 
secured  in  a  carrier,  which  la  made  to  advance  and  recede  alternately  by  means  of 
a  throw-crank,  and  thereby  thrust  the  prongs  into  and  draw  them  out  of  contact  with 
the  brushes.  The  carrier  consists  of  two  metal  plates,  the  lower  one  carrying  a  cushion 
of  vulcanized  India-rubber  for  the  fork  handles  to  rest  upon,  and  the  upper  being  lined 
with  leather ;  they  are  hinged  together  at  one  end,  and  are  connected  at  the  other, 
when  the  handles  have  been  placed  between  them,  by  a  thumb-screw. 


8 


LABOR-SAVING  MACHINES. 


Chopping-hnifc. — The  same  exhibitor  also  contributed  a  chopping-knife  for  the  re- 
ductiou  of  suet,  Ac,  into  small  particles.     It  consists  of  three  blades  tixed  side  by  side 
to  the  lower  surface  of  a  flat  metal  frame,  which  is  hinged  atone  end  to  a  fixed  metal 
pillar  or  support,  and  at  the  other  is  provided  with  a  handle,  whereby  the  blades  are 
alternately  lifted  and  brought  down  upon  the  suet  or  other  substance  to  be  chopped 
which  is  laid  upon  a  circular  wooden  dish  or  chopping-block.     Each  time  that  the 
knife-frame  is  raised,  a  hooked  rod,  suspended  therefrom,  catches  into  the  teeth  of  a 
ratchet  wheel,  and  turns  it  partly  round ;  on  the  axis  of  this  ratchet  wheel  is  a  small 
cog-wheel,  which  takes  into  the  teeth  of  a  circular  rack  or  wheel,  fixed  to  the  under- 
side of  the  chopping-block  ;  and  thus,  at  each  ascent  of  the  knife-frume,  the  block  will 
be  moved  partly  round,  and  made  to  present  fresh  portions  of  suet  to  the  action  of 
the  descending  knives.— Newton  s  Journal,  xxxix.  132. 

Envelope  folding.— In  the  envelope  folding  machine  of  Messrs.  De  la  Rue  <fe  Co.  each 
piece  of  paper  previously  cut  by  a  fly  press  into  the  proper  form,  for  making  an  en- 
velope (and  having  the  emblematical  stamp  or  wafer  upon  it),  is  laid  by  the  attendant 
on  a  square  or  rectangular  metal  frame  or  box,  formed  with  a  short  projecting  piece 
at  each  corner,  to  serve  as  guides  to  the  paper,  and  furnished  with  a  movable  bottom, 
which  rest«  on  helical  springs.     A  presser  at  the  end  of  a  curved  compound  arm 
(which  moves  in  a  vertical  plane),  then  descends  and  presses  the  paper  down  into  the 
box — the  bottom  thereof  yielding  to  the  pressure ;  and  thereby  the  four  ends  or  flaps 
of  the  piece  of  paper  are  caused  to  Ry  up  ;  the  presser  may  be  said  to  consist  of  a  rec- 
tangular metal  frame,  the  ends  of  which  are  attached  to  the  outer  part  of  the  curved 
arm,  and  the  sides  thereof  to  the  inner  portion  of  the  arm ;  so  that  the  ends  and  sides  of 
the  presser  can  move  independently  of  each  other.     The  ends  of  the  presser  then  rise, 
leaving  the  two  sides  of  it  still  holding  down  the  paper ;  two  little  lappet  pieces  next 
fold  over  the  two  side  flaps  of  the  envelope ;  and  immediately  a  horizontal  arm  ad- 
vances, carrying  a  V  shaped  piece  charged  with  adhesive  matter  or  cement  (from  a 
saturated  endless  band),  and  applies  the  same  to  the  two  flaps.     A  third  lappet  presses 
down  the  third  flap  of  the  envelope  upon  the  two  cemented  flaps,  and  thereby  causes 
it  to  adhere  thereto ;  and  then  a  pressing  piece  of  the  same  size  as  the  finished  enve- 
lope, folds  over  the  last  flap  and  presses  the  whole  flat     The  final  operation  is  to  re- 
move the  envelope,  and  this  is  effected  by  a  pair  of  metal  fingers,  with  India-rubber 
ends,  which  descend  upon  the  envelope,  and,  moving  sideways,  draw  the  envelope 
otF  the  bottom  of  the  box  (the  pressing-piece  having  moved  away  and  the  bottom  of 
the  box  risen  to  the  level  of  the  platform  of  the  machine)  on  to  a  slowly  moving  end- 
less band,  which  gradually  carries  the  finished  envelopes  away.     A  fresh  piece  of 
paper  is  laid  upon  the  box  or  frame,  and  the  above  operations  are  repeated. 

The  working  of  this  ingenious  machine  appeared  to  be  one  of  the  chief  attractions  of 
the  Exhibition,  but  another,  for  the  same  object,  invented  by  Mr.  A.  Remond,  of 
Birmingham,  and  shown  in  operation  by  Messrs.  Waterlow  <fe  Sons,  of  London  Wall, 
was  equally  deserving  attention.  The  distinguishing  feature  of  this  arrangement  is  the 
employment  of  atmospheric  pressure  to  feed  in  the  paper  which  is  to  form  the  envelope, 
and  to  deflect  the  flaps  of  the  envelope  into  inclined  positions,  to  facilitate  the  action  of 
a  plunger,  which  descends  to  complete  the  folding.  The  pieces  of  paper,  cut  to  the 
proper  form,  are  laid  on  a  platform,  which  is  furnished  with  a  pin  at  each  corner  to 
enter  the  notches  in  the  pieces  of  paper,  and  retain  them  in  the  proper  position,  and 
such  platform  is  caused  alternately  to  rise  and  bring  the  upper  piece  of  paper  in  con- 
tact with  the  instrument  that  feeds  the  folding  part  of  the  machine,  and  then  to  de 
scend  until  a  fresh  piece  is  to  be  removed.  The  feeding  instrument  consists  of  a  hori- 
zontal hollow  arm,  with  two  holes  in  the  under  side,  and  having  a  reciprocating 
movement.  When  it  moves  over  the  upper  piece  of  paper  on  the  platform,  a  partial 
vacuum  is  produced  within  it,  by  a  suitable  exliausting  apparatus,  and  the  paper  is 
thereby  caused  to  adhere  to  it  at  the  holes  in  it«  under  surface  by  the  pressure  of  the 
atmosphere.  The  instrument  carries  the  paper  over  a  rectangular  recess  or  box,  and 
then,  the  vacuum  within  it  being  destroyed,  it  deposits  the  paper  between  four  pins, 
fixed  at  the  angles  of  the  box,  and  returns  for  another  piece  of  paper.  As  the  paper 
lies  on  the  top  of  the  box,  the  flap,  which  will  be  undermost  in  the  finished  enve- 
lope, is  pressed  by  a  small  bar  or  presser  on  to  the  upper  edge  of  two  angular  feed- 
ers, communicating  with  a  reservoir  of  cement  or  adhesive  matter,  and  thereby  be- 
comes coated  with  cement ;  and,  at  the  same  time,  the  outermost  or  seal  flap  may  be 
stamped  with  any  required  device,  by  dies,  on  the  other  side  of  the  machine.  A  rec- 
tangular franie  or  plunger  now  descends  and  carries  the  paper  down  into  the  box ; 
the  plunger  rises,  leaving  the  flaps  of  the  envelope  upright;  streams  of  air,  issuing 
from  a  slot  in  each  side  of  the  box,  then  cause  the  flaps  to  incline  inwards ;  and  the 
folding  is  completed  by  the  plunger  again  descending,  the  interior  and  under  surface 
of  such  plunger  being  formed  with  projecting  parts,  suitable  for  causing  the  several 
flaps  to  fold  in  the  proper  order.     The  bottom  of  the  box  (which  is  hinged)  opens, 


i 


.1 

t 


LABOR-SAVING  MACHINES.  9 

and  discharges  the  envelope  down  a  shoot  on  to  a  table  below;  the  feeding  instrument 
then  brings  forward  another  piece  of  paper;  and  a  repetition  of  the  above  movementa 
takes  place. 

A.  machine  for  a  somewhat  similar  purpose  to  the  above  was  exhibited  by  Mr.  J.  Black, 
of  Edinburgh.     The  object  of  this  machine  is  to  fold  printed  sheets  of  paper,  and  it 
is  proportioned  to  fold  them  to  the  octavo  size;  but  machines  may  be  made,  on  the 
same  princi[)le,  to  suit  books  or  pamphlets  of  other  sizes.    To  fold  sheets  for  an  octavo 
book,  three  movements  are  required,  viz. :  first  to  fold  the  sheet  to  half  size;  secondlv, ' 
to  double  it  at  right  angles;  and  thirdl}^  to  double  it  again  at  right  angles  to  the  last 
fold.     In  the  machine  these  movements  are  effected  by  three  blades  or  knives,  which 
are  formed  with  serrated  edges,  to  prevent  the  paper  slipping.     The  blades  are  affixed, 
at  one  end,  to  separate  shafts  or  spindles,  which  simultaneously  perform  part  of  a 
revolution  in  either  direction  alternately,  and  so  cause  the  outer  end  of  each  blade 
to  describe  an  arc  of  about  the  fourth  part  of  a  circle;    and  as  the  actions  of  the 
knives  are  simultaneous,  the  machine  contains  three  sheets,  in  different  states  of  pro- 
gression at  the  same  time.     The  sheet  of  paper  is  laid  on  a  horizontal  platform,  in 
such  a  position  that  the  first  blade  in  descending  will  come  across  that  part  of  the 
paper  where  the  first  fold  is  to  be  made, — draw  the  sheet  through  a  slot  or  opening 
made  in  the  platform,  and  carry  it  down  into  a  narrow  vertical  passage,  or  chamber; 
by  which  means  it  will  be  folded  in  half,  and  left  in  a  vertical  position.     The  second 
blade  (which  vibrates  in  a  horizontal  plane),  then  comes  in  contact  with  the  central 
part  of  the  doubled  sheet  and  folds  it  at  that  part,  by  drawing  it  into  a  narrow  hori- 
zontal passage, — leaving  such  fold  in  a  line  at  right  angles  to  the  vertical  passage. 
The  third  blade  (which  vibrates  in  a  vertical  plane  parallel  to  the  first  blade)  draws 
the  sheet  down  a  vertical  passage,  so  as  to  fold  it  again,  and  brings  it  to  a  pair  of 
vertical  delivering  rollers,  which  pass  it  from  the  machine.     Accuracy  in  laying  the 
sheets  upon  the  platform  is  insured  by  an  arrangement  consisting  of  a  short  adjusta- 
ble straight  edge,  set  parallel  to  the  first  blade,  and  of  a  projecting  nob,  set  in  the 
same  parallel  line.     The  attendant  who  feeds  the  machine,  takes  hold  of  the  sheet  at 
the  edge  of  the  letter-press,  and  thus  lays  it  on  the  platform  in  such  a  manner  that 
his  fingers  come  in  contact  with  the  straight-edge  and  nob, — whereby  the  central  line 
of  the  sheet  will  be  caused  to  lie  exactly  over  the  central  slot  in  the  platform;  the 
position  of  the  nob  also  indicates  the  point  where  the  corner  of  the  letter-press  should 
be,  in  order  that  the  subsequent  folding  in  the  opposite  direction  may  be  accurately 
performed.     This  is  a  very  ingenious  and  eflScient  contrivance,  and  is  well  deserving 
the  attention  of  bookbinders. 

Paging  Books. — A  self-acting  machine  for  pagmg  books  and  numbering  documents 
was  exhibited  by  Messrs.  Waterlow  <fe  Sons,  and  shown  in  operation.  As  this  class  o| 
machmes  has  of  late  come  into  extensive  use,  owing  to  the  protection  which  is  afl^'orded 
to  the  merchant  and  the  tradesman  by  the  consecutive  paging  of  account  and  other 
manusciipt  books,  it  may  be  well  to  explain  the  general  construction  of  the  numbering 
apparatus,  and  its  mode  of  operation,  more  especially  as  it  forms  an  important  adjunct 
to  some  machines  which  we  shall  hereafter  have  occasion  to  notice.  The  numbering  ap- 
paratus consists  of  five  discs,  which  are  provided  with  raised  figures  on  their  periphery 
running  from  1,  2,  3,  <kc.,  to  0 ;  and  these  figures  serve  (like  letter-press  type)  to  print  the 
numbers  required.  The  discs  are  mounted  at  the  outer  end  of  a  vibrating  frame  or  arm 
on  a  common  shaft,  to  which  the  first  or  units  discs  is  permanently  fixed  •  and  the  other 
four  discs  (viz.,  those  for  making  tens,  hundreds,  thousands,  and  tens  of  thousands,)  are 
mounted  loosely  thereon,  so  that  they  need  not,  of  necessity,  move  when  the  shaft  ia 
rotating;  but  they  are  severally  caused  to  move  in  the  following  order-— the  tens  disc 
performs  one-tenth  of  a  revolution  for  every  revolution  of  the  units  disc,  and  so  on  Aa 
the  discs  rise  from  the  paper  after  every  impression,  the  units  disc  is  caused  to  perform 
one-tenth  of  a  revolution  (in  order  that  the  next  number  printed  maybe  a  unit  greater 
than  the  preceding  one),  by  a  driving  click  taking  into  the  teeth  of  a  ratchet-wheel 
fixed  on  the  left  hand  end  of  the  shaft  The  movement  of  the  other  discs  is  effected 
at  intervals,  by  means  of  a  spring-catch,  affixed  to  the  side  of  the  units  disc,  and  ro- 
tating therewith;  which  catch,  each  time  that  the  units  disc  completes  a  revolution 
IS  caused  by  a  projection  on  the  inner  surface  of  the  vibrating  frame  to  project  behind 
one  of  the  raised  figures  on  the  tens  disc,  and  carry  it  round  one-tenth  of  a  revolution 
on  the  next  movement  of  the  units  disc  tiking  place ;  and  then,  the  catch  having  passed 
away  from  tlie  projection  no  further  increase  in  the  number  imprinted  bv  the  tens 
disc  will  be  effected  unt.il  the  units  disc  has  performed  another  revolution.  Every  time 
that  the  tens  disc  completes  a  revolution,  the  spring-citch  causes  the  hundreds  disc  to 
move  forward  one-tenth  of  a  revolution,  and  similar  movements  are  imparted  to  the 
remaining  discs  at  suitable  times.  The  shaft  is  prevented  from  moving  except  when  it 
IS  acted  o^by  the  drivmg  chck,  by  a  spring  detent,  or  pull  enterin|  the  notehes  in 


10 


LAC,  LAC  DYE. 


ensured.     The  leaves  of  the  book  I/k         ^      ^°^  ®^^"  impression  of  the  fi.rurfs  is 
of  the  table  of  the  r^lohine%o^^^^^^^^  Tk  ^'^'^  ^'^  the  rakd'a 

numbered  it  is  turned  over  b^he  attending  «o  1  '°^^*-^"bber,  and  as  each  page  is 
next  descent.     As  the  discs  ascend  «ftlt         V^-*^  ^  P^^^^^*  *  ^^esh  page  on  their 
^  (consisting  of  three  rolleTzTounted  fn  a  ZTn^"fr2^rV''^%  ""^  inkiSg^apparatu 
each  other  so  as  to  distribute  the   nk  wh!chTfedTfh?fi  T"  ^^  '"^  «^«^«^^  ^^^h 
third  or  mking  roIlerX  descends  and  inks  the  LntliS-  ?''     '*?"f  ^7^**^^  «"  *«  the 
tion  when  the  numbering  apparaturnextdecpXV^i-^  *'^  ^^^^  ^^^"g^t  into  ae- 
may  be  paged  or  marked  w  th  consecu^ivp  nnmK         /  *^''  "?^*°«  ^««^«  or  documents 
bers,  as  for  banker^'books  asimnWni  •         ?^^^'^'  f^'"  Panting  duplicate  sets  of  num! 
n  theemplovmentofanadditrn&t"^^^^^^^^^  Thton^^s 

that  moves  the  ratchet-wheel  abov^  mln  ?^  which  is  acted  on  bvthe  driving  click 
teeth  to  that  wheel.     B^t  the  d  WtTo  tSfad'^ 

admit  of  the  teeth  being  so  formed  thnff  ],./••  ?^''*^^^^^^^el  is  increased  to 
from  contact  with  evervflWn«f!^fifW.u^  1"'^'""  "^^'^^  ^'"  ^e  thereby  held  back 
the  arrangement  of  thYnumSgtsl^^^^^  -tchet-wheeT;  and  thus 

descent,  a  duplicate  impression  of  fhfnumTir  ^T.  ^  ^'^'^."ge  J  to  give,  on  their  next 
ing  9f  the  numbering  apnaratu.  ihl  °"°?^^'^.  P^'^^ou^ly  pnnted ;  but,  on  the  reascend- 
and  move  both  forwfrd^oTtenth 'o^a^t^^^^^^^^^  Zl  '"^'.^  ^'^/^  ratchet-wheels, 
first  ratchet-wheel  in  itsmovements  the  n«^W  tnf         ^  *^'^  ^,^^'^^  accompanies  the 

Messrs.  Schlesin-er  &  Co  also  exhibif!^^^     •      "  consequently  be  changed, 
are  similar  to  the  above,  but  somewhat^^^^^^^  ^Ij^  -P-^ilitie^s  of  which 

this  instance  are  provided  with  tpn  wi?  ,  •♦t  ^-  .  J°^^  ^^®  numbering  discs  in 
and  they  receive  fhe  change  motion  tomZailZT^  ^^T^?  \'''  ^"^  «^  ea!h  tooth! 
frame.     At  each  descent  cTf  th^  fmmeTstS  ^  •  "°^^^  ^"^^^  *^«"»  «"  the  same 

i-ound  the  wheel  one  tooth,  that  gear!  !nto  he  tXtT^^AT'"^  -^^  hook-piece  drivel 
causes  the  units  disc  to  bring  forward  a  ^l^J'fi  ^^  ^l  ^''^  ""^^^  <i'««.  and  thereby 
what  narrower  than  the  nurfberi^^  discs  but  onf  t'oAt  W  'T^t^  ^^''^'  «^«  'oj- 
rally  to  about  double  the  size  of  throther  ee?^  ?n  fW^^'^l^  is  enlarged  late- 
revolution  of  the  wheel  the  projectrng  o^th  fhall  l.f  **  *^  completion  of  every 
and  carry  that  disc  forward  oneSS^of  a  revolution  "??M  ^^^'^  ^^  *^^  ^^^<^  d'«^> 
movements  of  the  discs  for  effecting  thi  rLni  '     ^^  ^^'^  ^^^^^n^  the  requisite 

duced ;  the  first  wheel  driving  its  o^ndis/l^^^^^^^  «^  '^^  """^bers  a?e  pro! 

the  next  disc,  and  the  other  whLl  each  rec.ivJn"."'"*^'"^  "^"^^^^  *<^  intervafsto 

onfo?  q?or:trv:::rfl[:rE^  ^t'ef?^:?  IL'^S^^^  ^5  IrV^^^^^  spHng-cat^h 
^'^hf  nu?b:r!lSay  fe P^^^d%^^^^^^^^^^^^^  ^^^  n^^fmrreU^^-^^  ^^^^^^"^  ^^ 
or  all  odd  nt^Tby  Vri  g  r^^^^  I^ond  c:t:h  l^to  ^7^'^^T'  T  ^  ^^^  P^^  '^^  -en 
to  advance  one  step  during  the  arpmll  ^""^T'  ^*^^«^  ^a^ses  the  unit  disc 

advance  during  the^descent^of  tL  sam^^^^  "^^^  ^^"°^^'  ^^  *^<^ition  ^  the 

LABRADORITE.  onalinp  nr  r  oK^       r  t^'^'^  *  Journal,  xxxviii.  43a 

changing  colors^luC/ed^an^^^^^^^  t'eT'  ^  ^^r^iful  niine^,  with  brilliant 

affords  no  water  by  calcin'ation  fSlt at  thl^hf^J'- ''*  ^'^^  *^  ^'"^^^     ^^^^tches  gS 
muriatic  acid;   solution  affords  a  S^^^^^  frothy  bead;  soluble  in' 

ages  of  93|°  and  86^ :  one  of  whirh^«  K?fn^  ^l   ^,^'*^  ""^^^^te  of  ammonia.      Cleav- 
55;75;  aluLina,264;'C7ii7sSt  4^;^"i^  Its  constituents  are  sS, 

LABYRINTH,  in  ietaUurgy,'  m^ns  a  serie.  nf  ''''"'.  ^1? '  ^^'^^>  O'^' 
a  stamping-miU;  through  whkh^ands  a  s^relm^n?     f  ^^^^"^"ted  in  the  sequel  of 
mg,  .rrying  off,  and  depositing,  ar^er^nf  SI^LT^  ^^ ^^  t  "S^S^ 

the^lPnk^^™  Stick-Iacis  produced  by 

of  several  plants;  as  the  Jicus  rellgiosa  thefill^Zi^''^'''  f""'*  "P^"  ^«  ^^^"^hes 

abar.     The  twig  becomes  thereby  inTrSstef^li^    ^^^  ^''*™'  ^^^'  ^^°?^»  and  Mal- 
crystaUine-looking  fracture,  """^^^y '''*'"*^^^^  ^thr  a  reddish  mammelated  resin,  having  a 

The  female  lac  insect  is  of  the  shf  nf  «  i« 
circles,  a  bifurcated  tail,  antenn^^d  6 Iws  haff\h^^^  'TVf'.^^'^  ^^  abdominal 
twice  the  above  size,  and  has  4  winX.  thl^7^'  *i^^,  ^^"^^^  «^  the  body.  The  male  is 
ber  or  December  theVoun^roc^Sef^^s  elT  f^'^!?^  to  5000  females.  In  Novem! 
body  of  the  mother ;  they  crawl  a  W  a  l/ttl?l^  ""^^^^  ^^^^'  ^>'i"?  ^^n^^th  the  dead 
the  shrubs.  About  this  perirthe  baches  oft p?'  ^""^  ^^'^''^  themselves  to  the  bark  of 
min  that  they  seem  covered  with  a  rSdus^  .7^" '" '^'\^  ^^^^^^  ^^^^  '^^  verw 
by  being  exhausted  of  their  juices      Manv  nf  ?»,     ''.''^'^'  ^^^^  ^^  «?*  to  dry  up, 

juices.     Many  of  these  insects,  however,  become  the 


LAC,  LAC  DYE. 


11 


)' 


prey  of  others,  or  are  carried  off  by  the  feet  of  birds,  to  which  they  attach  themselves, 
and  are  transplanted  to  other  trees.  They  soon  produce  small  nipple-like  incrusta* 
tions  upon  the  twigs,  their  bodies  being  apparently  glued,  by  means  of  a  transparent 
liquor,  which  goes  on  increasing  to  the  end  of  March,  so  as  to  form  a  cellular  texture. 
At  this  time,  the  animal  resembles  a  small  oval  bag,  without  life,  of  the  size  of  cochineal. 
At  the  commencement,  a  beautiful  red  liquor  only  is  perceived,  afterwards  eggs  make 
their  appearance  ;  and  in  October  or  November,  when  the  red  liquor  gets  exhausted,  20 
or  30  young  ones  bore  a  hole  through  the  back  of  their  mother,  and  come  forth.  The 
empty  cells  remain  upon  the  branches.  These  are  composed  of  the  milky  juice  of  the 
pilfint,  which  serves  as  nourishment  to  the  insects,  and  which  is  afterwards  transformed 
or  elaborated  into  the  red  coloring  matter  that  is  found  mixed  with  the  resin,  but  in 
greater  quantity  in  the  bodies  of  the  insects,  in  their  eggs,  and  still  more  copiously  in  the 
red  liquor  secreted  for  feeding  the  young.  After  the  brood  escapes,  the  cells  contain 
much  less  coloring  matter.  On  this  account,  the  branches  should  be  broken  off  before 
this  happens,  and  dried  in  the  sun.  In  the  East  Indies  this  operation  is  performed  twice 
n  the  year ;  the  first  time  in  March,  the  second  in  October.  The  twigs  incrusted  with 
the  radiated  cellular  substance  constitute  the  stick4ac  of  commerce.  It  is  of  a  red 
color,  more  or  less  deep,  nearly  transparent,  and  hard,  with  a  brilliant  conchoidal  fracture. 
The  stick-lac  of  Siam  is  the  best ;  a  piece  of  it  presented  to  me  by  Mr.  Rennie,  of  Fen- 
chuich-street,  having  an  incrustation  fully  one  quarter  of  an  inch  thick  all  round,  the 
twig.  The  stick-lac  of  Assam  ranks  next ;  and  last,  that  of  Bengal,  in  which  the  resinous 
coat  is  scanty,  thin,  and  irregular.  According  to  the  analysis  of  Dr.  John,  stick-lac 
consists,  in  120  parts,  of — 


An  odorous  common  resin    -  -  • 

A  resin  insoluble  in  ether     -  -  - 

Coloring  matter  analogous  to  that  of  cochineal 
Bitter  balsamic  matter  -  _  - 

Dun  yellow  extract  -  -  -  - 

Acid  of  the  stick-lac  (laccic  acid)    - 
Fatty  matter,  like  wax  -  -  - 

Skin  of  the  insects  and  coloring  matter 
Salts  ..... 

Earths  -  -  .  -  . 

Loss  -  •  •  .  • 


♦     . 


80-00 
20-00 
4-50 
3-00 
0-50 
0-75 
3-00 
2-.50 
l-2i> 
0-75 
4-75 

120-00 


%. 


According  to  Franke,  the  constituents  of  stick-lac  are,  resin,  65-7 ;  substance  of  the 
lac,  28-3  ;  coloring  matter,  0-6. 

Seed-lac. — When  the  resinous  concretion  is  taken  off  the  twigs,  coarsely  pounded,  and 
triturated  with  water  in  a  mortar,  the  greater  part  of  the  coloring  matter  is  dissolved,  and 
the  granular  portion  which  remains,  being  dried  in  the  sun,  constitutes  seed-lac.  It  con- 
tains of  course  less  coloring  matter  than  the  stick-lac,  snd  is  much  less  soluble.  John 
found  in  100  parts  of  it,  resin,  66-7;  wax,  1-7;  matter  of  the  lac,  16-7;  bitter  balsamic 
matter,  2-5;  coloring  matter,  3-9;  dun  yellow  extract,  0-4 ;  envelopes  of  insects,  2-1  j 
laccic  acid,  0-0 ;  salts  of  potash  and  lime,  1-0 ;  earths,  6-6 ;  loss,  4-2. 

In  India  the  seed-lac  is  put  into  oblong  bags  of  cotton  cloth,  which  are  held  over  a 
charcoal  fire  by  a  man  at  each  end,  and,  as  soon  as  it  begins  to  melt,  the  bag  is  twisted 
so  as  to  strain  the  liquefied  resin  through  its  substance,  and  to  make  it  drop  upon  smooth 
stems  of  the  banyan  tree  {musa  paradisa).  In  this  way,  the  resin  spreads  into  thin 
plates,  and  constitutes  the  substance  known  in  commerce  by  the  name  of  shellac. 

The  Pegu  stick-lac,  being  very  dark-colored,  furnishes  a  shellac  of  a  corresponding 
deep  hue,  and  therefore  of  inferior  value.  The  palest  and  finest  shellac  is  brought  from 
the  northern  Circar.  It  contains  very  little  coloring  matter.  A  slick-lac  of  an  interme- 
diate kind  comes  from  the  Mysore  country,  which  yields  a  brilliant  lac-dye  and  a  good 
shellac. 

Lac-dye  is  the  watery  infusion  of  the  ground  stick-lac,  evaporated  to  dryness,  and 
formed  into  cakes  about  two  inches  square  and  half  an  inch  thick.  Dr.  John  found  it 
to  consist  of  coloring  matter,  50 ;  resin,  25 ;  and  solid  matter,  composed  of  alumina, 
plaster,  chalk,  and  sand,  22. 

Dr.  Macleod,  of  Madras,  informs  me  that  he  prepared  a  very  superior  lac-dye  from 
stick-lack,  by  digesting  it  in  the  cold  in  a  slightly  alkaline  decoction  of  the  dried  leaves 
of  the  MemecyUm  tinctorium  (perhaps  the  M.  capitellatum,  from  which  the  natives  of 
Malabar  and  Ceylon  obtain  a  safl'ron-yellow  dye).  This  solution  being  used  along  with 
a  mordant,  consisting  of  a  saturated  solution  of  tin  in  muriatic  acid,  was  found  to  dye 
woollen  cloth  of  a  very  brilliant  scarlet  hue.  / 


12 


LAC,  LAC  DYE. 


LACE  BOBBINET. 


13 


The  cakes  of  lac-dye  imported  from  India,  stamped  with  peculiar  marks  to  designate 
their  different  manufacturers,  are  now  employed  exclusively  in  England  for  dyeing 
scarlet  cloth,  and  are  found  to  yield  an  equally  brilliant  color,  and  one  less  easily 
affected  by  perspiration  than  that  produced  by  cochineal.  "When  the  lac-dye  was  first 
introduced,  sulphuric  acid  was  the  solvent  applied  to  the  pulverized  cakes,  but  as  mu- 
riatic acid  has  been  found  to  answer  so  much  better,  it  has  entirely  supplanted  it.  A 
good  solvent  (No.  1)  for  this  dye-stuff  may  be  prepared  by  dissolving  three  pounds  of  tin 
in  60  pounds  of  muriatic  acid,  of  specific  giavity  1*19.  The  proper  mordant  for  the 
cloth  is  made  by  mixing  27  pounds  of  muriatic  acid  of  sp.  grav.  1*17,  with  1^  pounds 
of  nitric  acid  of  1*19;  putting  this  mixture  into  a  salt-glazed  stone-bottle,  and  adding 
to  it,  in  small  bits  at  a  time,  grain  tin,  till  4  pounds  be  dissolved.  This  solution  (No.  2) 
may  be  used  within  twelve  hours  after  it  is  made,  provided  it  has  become  cold  and  clear. 
For  dyeing,  three  quarters  of  a  pint  of  the  solvent  No.  1  is  to  be  poured  upon  each 
pound  of  the  pulverized  lac-dye,  and  allowed  to  digest  upon  it  for  six  hours.  The  cloth, 
before  being  subjected  to  the  dye  bath,  must  be  scoured  in  the  mill  with  fullers'  earth. 
To  dye  100  pounds  of  pelisse  cloth,  a  tin  boiler  of  300  gallons  capacity  should  be  filled 
nearly  brimful  with  water,  and  a  fire  kindled  under  it.  Whenever  the  temperature 
rises  to  150°  Fahr.,  a  handful  of  bran  and  half  a  pint  of  the  solution  of  tin  (No.  2) 
are  to  be  introduced.  The  froth,  which  rises  as  it  approaches  ebullition,  must  be 
skijinmed  off;  and  when  the  liquor  boils,  10|  pounds  of  lack-dye,  previously  mixed  with  7 
pints  of  the  solvent  No.  1,  and  3|  pounds  of  solution  of  tin  No.  2,  must  be  poured  in. 
An  instant  afterwards,  10|  pounds  of  tartar,  and  4  pounds  of  ground  sumach,  both  lied  up 
in  a  linen  bag,  are  to  be  suspended  in  the  boiling  bath  for  five  minutes.  The  fire  being 
now  withdrawn,  20  gallons  of  cold  water,  with  10|  pints  of  solution  of  tin,  being  poured 
into  the  bath,  the  cloth  is  to  be  immersed  in  it,  moved  about  rapidly  during  ten  minutes  j 
the  fire  is  to  be  then  rekindled,  and  the  cloth  winced  more  slowly  through  the  bath, 
which  must  be  made  to  boil  as  quickly  as  possible,  and  maintained  at  that  pitch  for  an 
hour.  The  cloth  is  to  be  next  washed  in  the  river ;  and  lastly,  with  water  only,  in  the 
fulling  mill.  The  above  proportions  of  the  ingredients  produce  a  brilliant  scarlet 
tint,  with  a  slightly  purple  cast.  If  a  more  orange  hue  be  wanted,  white  Florence  argal 
may  be  used,  instead  of  tartar,  and  some  more  simiach.  Lac-dye  may  be  substituted  for 
cochineal  in  the  orange-scarlets;  but  for  the  more  delicate  pink  shades,  it  does  not 
answer  so  well,  as  the  lustre  is  apt  to  be  impaired  by  the  large  quantity  of  acid  necessary 
10  dissolve  the  coloring  matter  of  the  lac. 

Shellac,  by  Mr.  Hatchett's  analysis,  consists  of  resin,  90*5;  coloring  matier,  0*5; 
wax,  4*0  ;  gluten,  2*8 ;  loss,  1'8  ;  in  100  parts. 

The  resin  may  be  obtained  pure  by  treating  shellac  with  cold  alcohol,  and  filtering 
the  solution  in  order  to  separate  a  yellow  gray  pulverulent  matter.  When  the  alcohol 
is  again  distilled  off,  a  brown,  translucent,  hard,  and  brittle  resin,  of  specific  gravity 
1*139,  remains.  It  melts  into  a  viscid  mass  with  heat,  and  difluses  an  aromatic  odor. 
Anhydrous  alcohol  dissolves  it  in  all  proportions.  According  to  John,  it  consists  of  two 
resins,  one  of  which  dissolves  readily  in  alcohol,  ether,  the  volatile  and  fat  oils ;  while 
the  other  is  little  soluble  in  cold  alcohol,  and  is  msoluble  in  ether  and  the  volatile  oils. 
Unverdorben,  however,  has  detected  no  less  than  four  dift'erent  resins,  and  some  other 
substances,  in  shellac.  Shellac  dissolves  with  ease  in  dilute  muriatic  and  acetic  acids ; 
but  not  in  concentrated  sulphuric  acid.  The  resin  of  shellac  has  a  great  tendency 
to  combine  with  salifiable  bases  ;  as  with  caustic  potash,  which  it  depiives  of  its  alkaline 
taste. 

This  solution,  which  is  of  a  dark  red  color,  dries  into  a  brilliant,  transparent,  reddish 
brown  mass ;  which  may  be  re-dissolved  in  both  water  and  alcohol.  By  passing  chlorine 
in  excess  through  the  dark-colored  alkaline  solution,  the  lac-resin  is  precipitated  in  a 
colorless  state.  When  this  precipitate  is  washed  and  dried,  it  forms,  with  alcohol,  an 
excellent  pale-yellow  varnish,  especially  with  the  addition  of  a  little  turpentine  and  mastic. 

With  the  aid  of  heat,  shellac  dissolves  readily  in  a  solution  of  borax. 

The  substances  which  Unverdorben  found  in  shellac  are  the  following : 

1.  A  resin,  soluble  in  alcohol  and  ether ; 

2.  A  resin,  soluble  in  alcohol,  insoluble  in  ether ; 

3.  A  resinous  body,  little  soluble  in  cold  alcohol ; 

4.  A  crj'stallizable  resin ; 

5.  A  resin,  soluble  in  alcohol  and  ether,  but  insoluble  in  petroleum,  and  uncnrs- 
tallizable. 

6.  The  unsaponified  fat  of  the  coccus  insect,  as  well  as  oleic  and  margaric  acids. 

7.  Wax. 

8.  The  laccine  of  Dr.  John. 

9.  An  extractive  coloring  matter. 


• 


4 


Statistical  Table  of  Lac-Dye  and  Lac-Lake,  per  favor  of  James  Wilkinson,  Esq*, 

of  Leadenhall  street. 


Import. 

Export. 

Horn* 
Consumption. 

Prices. 

Stocks. 

lbs. 

lbs. 

Jbs, 

1802 

253 

none 

1803 

1,735 

none 

acctunt  burned 

1804 

531 

_ 

1805 

1,987 

1806 

none 

1807 

25,350 

1808 

5,731 

1809 

40,632 

1810 

235,154 

1811 

378,325 

1812 

198,250 

1813 

289,654 

1814 

278,899 

5,071 

133,935 

1815 

598,592 

8,441 

137,915 

I8I6 

269,373 

27,412 

162,894 

1817 

384,909 

23,091 

234,763 

1818 

242,572 

32,079 

323,169 

1819 

179,511 

21,707 

20  ,063 

•     1820 

441,486 

49,519 

9^2,514 

1821 

641,755 

91,925 

322,837 

1822 

872,967 

29,578 

349,351 

1823 

534,220 

13,050 

414,714 

1824 

604,269 

53,843 

483,339 

1825 

541,443 

61,908 

385,734 

1826 

760,729 

68.603 

395,609 

1827 

756,315 

76,875 

448,270 

1     9 

4    0 

11,538 

1828 

512,874 

54,999 

397,867 

1     3 

3     9 

11,085 

1829 

475,632 

39,344 

433,851 

1     3 

3    6 

11,976 

1830 

534,341 

78,099 

5-1 8^865 

0     9 

3     3 

11,834 

1831 

913,562 

175,717 

597,568 

0     4 

2    6 

12,559 

1832 

378,843 

69,842 

594,155 

0    4 

2    3 

11,420 

1833 

326,894 

66,447 

426,460 

0     9 

2    4 

11,457 

1834 

708,959 

89,229 

398,832 

0  11 

2    4 

11,928 

1835 

528,564 

203,840 

573,288 

0  11 

3    0 

10,454 

1836 

612,436 

200,975 

642,615 

1     0 

4    0 

9,492 

1837 

1,011,674 

133,959 

427,890 

1     0 

3    9 

8,780 

The  stock  includf 

?s  2,200  chests  of  Lac-lake 

• 

Landings,  Deliveries,  and  Stocks  of  Lac  Dyes. 


Year. 


In  December  1851 
1850 

In  12  months  1851 
1860 
1849 
1848 


I.an(l(><l. 


4(>4  chests 

564 
7152 
5SG0 
3264 
15T7 


Delivered. 


?92  chests 

^^ 

308 

__ 

4741 

7777 

4063 

5356 

4126 

8559 

8020 

4421 

Stock  Ist  January. 

—  chests 


I 


>\ 


Layton,  Hulbcrt,  dt  Co.'s  Circular,  1th  Jan,,  1852. 

The  market  prices  on  8tli  Jan.  1852  were  from  3c?.  to  2%  4d.  per  lb. 

LACCIC  ACID  crystallizes,  has  a  wine-yellow  color,  a  sour  taste,  is  soluble  in  water, 
alcohol,  and  ether.     It  was  extracted  from  stick-lac  by  Dr.  John. 

LACCINE  is  the  portion  of  shell-lac  which  is  insoluble  in  boiling  alcohol.  It  is  brown, 
brittle,  translucid,  consisting  of  agglomerated  pellicles,  more  like  a  resin  than  any 
thing  else.     It  is  insoluble  in  ether  and  oils.     It  has  not  been  applied  to  any  use. 

LACE  BOBBINET.  Ilithorto  the  threads  of  silk,  flax,  or  cotton,  used  as  the  chain 
or  warp  in  the  manufacture  of  lace  or  net,  have  been  warped,  or  ranged  side  by  side, 
and  in  this  state  wound  upon  a  c^iinder,  which  being  mounted  upon  an  axle  or  shaft, 
delivers  the  warp  threads  as  each^uesh  of  the  net  is  formed.  By  the  patented  arrange- 
ment of  Mr.  W.  E.  Newton,  whatever  may  be  the  difference  in  the  consumption  of  the 
several  threads  to  produce  the  fabric,  in  cornjiarison  with  other  portions  of  the  warp, 
the  cylinder  will  always  deliver  the  same  quantity  in  length  of  each  thread.     This 


u 


LACE  MANUFACTURE. 


LACE  MANUFACTURE. 


15 


^  u^\u^?^  *^  ^^^^*  inconvenience.  According  to  the  present  invention,  for  every  thread 
a  bobbin  is  provided  for  regulating  its  tension;  and  thus  each  separate  thread  or 
number  of  threads  may,  without  inconvenience,  furnish  a  greater  or  less  length  of  warp 
as  may  be  required.      See   the  details,  with  figures,  in  Newton's  London  JourncU, 

3E5XV.  391.  * 

LACE  MANUFACTURE.  The  piUow-made,  or  bone-lace,  which  formerly  gave 
occupation  lo  multitudes  of  women  in  their  own  houses,  has,  in  the  progress  of  me- 
chanical invention,  been  nearly  superseded  by  the  bobbin-net  lace,  manufactured  at  first 
by  hand-machines,  as  stockings  are  knit  upon  frames,  but  recently  by  the  power  of 
water  or  steam.  This  elegant  texture  possesses  all  the  strength  and  regularity  of  the 
old  Buckingham  lace,  and  is  far  superior  in  these  respects  to  the  point-net  and  warp  lace 
which  had  preceded,  and  in  some  measure  paved  the  way  for  it.  Bobbin-net  may  be 
said  to  surpass  every  other  branch  of  human  industry  in  the  complex  ingenuity  of  its 
machmer}';  one  of  Fisher's  spotting  frames*  being  as  much  beyond  the  most  curious 
chronometer,  m  multipUcity  of  mechanical  device,  as  that  is  beyond  a  common  roastin*'- 
jack.  ^ 

The  threads  in  bobbin-net  lace  form,  by  their  intertwisting  and  deccussation,  re«nilar 
hexagonal  holes  or  meshes,  of  which  the  two  opposite  sides,  the  upper  and  under  are 
Oirected  along  the  breadth  of  the  piece,  or  at  right  angles  to  the  selvage  or  border. 

Fig.  833  shows  how,  by  the  crossing  and 
twisting  of  the  threads,  the  regular  six- 
sided  mesh  is  produced,  and  that  the  tex- 
ture results  from  the  union  of  three  sepa- 
rate sets  of  threads,  of  which  one  set  pro- 
ceeds downwards  in  serpentine  lines,  a 
second  set  proceeds  from  the  left  to  the 
ris:ht,  and  a  third  from  the  right  to  the 
left,  both  in  slanting  directions.  These 
oblique  threads  twist  themselves  round  the 
vertical  ones,  and  ialso  cross  each  other  be- 
twixt them,  in  a  peculiar  manner,  which 
may  be  readily  understood  by  examining 
the  representation.  In  comparing  bobbin- 
net  with  a  common  web,  the  perpendicular 
threads  in  the  figure,  which  are  parallel  to 
the  border,  may  be  regarded  as  the  warp, 
and  the  two  sets  of  slanting  threads,  as  the 
weft. 

These  warp  threads  are  extended  up  and  down,  in  the  original  mounting  of  the  piece 
between  a  top  and  bottom  horizontal  roller  or  beam,  of  which  one  is  called  the  warp 
beam,  and  the  other  the  lace  beam,  because  the  warp  and  finished  lace  are  wound  upon 
them  respectively.  These  straight  warp  threads  receive  their  contortion  from  the  tension 
of  the  weft  threads  twisted  obliquely  round  them  alternately  to  the  right  and  the  left 
hand.  Were  the  warp  threads  so  tightly  drawn  that  they  became  inflexible,  like 
fiddle-strings,  then  the  lace  would  assume  the  appearance  shown  in  fig  834;  and 
although  this  condition  does  not  really  exist,  it  may  serve  to  illustrate  the  structure  of 
the  web.  The  warp  threads  stand  in  the  positions  a  a,  a'  a',  and  a"  a"  j  the  one  half 
of  the  weft  proceeds  in  the  direction  b  h,  b'  b',  and  b"  b" ;  and  the  second  crosses  the 

fiist  bv  running  in  the  direction  c  c,  oi 
c'  c',  towards  the  opposfile  side  of  the  fab- 
ric.  \i  we  pursuf.  the  path  of  a  wefl 
thread,  we  find  it  goes  on  till  it  reaches 
the  outermost  or  last  warp  thread,  which  it 
twists  about ;  not  once,  as  with  the  others, 
but  twice ;  and  then  returning  towards  the 
other  border,  proceeds  in  a  reverse  direc- 
tion. It  is  by  this  double  twist,  and  by  the 
return  of  the  weft  threads,  that  the  selvage 
is  made. 

The  ordinary  material  of  bobbin-net  is 
two  cotton  yarns,  of  from  No.  180  to  No. 
250,  twisted  into  one  thread ;  but  some- 
times strongly  twisted  single  yarn  has  been 
used.  The  beauty  of  the  fabric  depends 
upon  the  quality  of  the  material,  as  well  as 
the  regularity  and  smallness  of  the  meshes. 
The  number  of  warp  threads  in  a  yard  in 


^■. 


breadth  is  from  600  to  900 ;  which  is  equivalent  to  from  20  to  30  in  an  inch.  The  size 
of  the  holes  cannot  be  exactly  inferred  from  that  circumstance,  as  it  depends  partly  upon 
the  oblique  traction  of  the  threads.  The  breadth  of  the  pieces  of  bobbin-net  varies 
from  edgings  of  a  quarter  of  an  inch,  to  webs  12,  or  even  20  quarters,  that  is,  5  yards 
wide. 

Bobbin-net  lace  is  manufactured  by  means  of  very  costly  and  complicatea  machines, 
called  frames.  The  limits  of  this  Dictionary  will  admit  of  an  explanation  of  no  more 
than  the  general  principles  of  the  manufacture.  The  threads  for  crossing  and  twisting 
round  the  warp,  being  previously  gassed,  that  is,  freed  from  loose  fibres  by  singeing  with 
gas,  are  wound  round  small  pulleys,  called  bobbins,  which  are,  with  this  view,  deeply 
grooved  in  their  periphery.    Figs.  836. 836.  exhibit  the  bobbin  alone,  and  with  its  carriage, 

836 


835 


\ 


In  the  section  of  the  bobbin  a,  fig.  835.  the  deep  groove  is  shown  in  which  the  thread  is 
wound.  The  bobbin  consists  of  two  thin  discs  of  brass,  cut  out  in  a  stamp-press,  in  the 
middle  of  each  of  which  there  is  a  hollow  space  c.  These  discs  are  riveted  together,  leaving 
an  interval  between  their  edge  all  round,  in  which  the  thread  is  coiled.  The  round  hole 
in  the  centre,  with  the  little  notch  at  top,  serves  for  spitting  them  upon  a  feathered  rod, 
in  order  to  be  filled  with  thread  by  the  rotation  of  that  rod  in  a  species  of  reel,  called 
the  bobbin-filling  machine.  Each  of  these  bobbins  (about  double  the  size  of  tho 
figure),  is  inserted  into  the  vacant  space  g,  of  the  carriage,  fig.  836.  This  is  a  small 
iron  frame  (also  double  the  size  of  the  figure),  which,  at  €  c,  embraces  the  grooved 
border  of  the  bobbin,  and  by  the  pressure  of  the  spring  at  /,  prevents  it  from  falling  out. 
This  spring  serves  likewise  to  apply  sufficient  friction  to  the  bobbin,  so  as  to  prevent  it 
from  giving  off'  its  thread  at  g  by  its  rotation,  unless  a  certain  small  force  of  traction  be 
employed  upon  the  thread.  The  curvilinear  groove  h  h,  sunk  in  each  face  or  side  of 
the  carriage,  has  the  depth  shown  in  the  section  at  h.  This  groove  corresponds  to  the 
interval  between  the  teeth  of  the  comb,  or  bars  of  the  bolt,  in  which  each  carriage  is 
placed,  and  has  its  movement.  A  portion  of  that  bolt  or  comb  is  shown  at  a,  fig.  837 
in  plan,  and  one  bar  of  a  circular  bolt  machine  at  6,  in  section.  If  we  suppose  two 
such  combs  or  bolts  placed  with  the  ends  of  the  teeth  opposite  each  other,  but  a  little 
apart,  to  let  the  warp  threads  be  stretched,  in  one  vertical  plane,  between  their  endf  or 
tips,  we  shall  have  an  idea  of  the  skeleton  of  a  bobbin-net  machine.  One  of  these  two 
combs,  in  the  double  bolt  machine,  has  an  occasional  lateral  movement  called  shagging^ 
equal  to  the  interval  of  one  tooth  or  bolt,  by  which,  after  it  has  received  the  bobbins, 

with  their  carriages,  into  its  teeth,  it 
can  shift  that  interval  to  the  one 
Side,  and  thereby  get  into  a  position 
to  return  the  bobbins,  with  their 
carriages,  into  the  next  series  of  in- 
terstices or  gates,  in  the  other  bolt. 
By  this  means  the  whole  series  of 
carriages  receives  successive  side 
steps  to  the  right  in  one  bolt,  and  to 
the  left  in  the  other,  so  as  to  per- 
form a  species  of  countermarch,  in 
the  course  of  which  they  are  made 
to  cross  and  twist  round  about  the 
vertical  warp  threads,  and  thus  to 
form  the  meshes  of  the  net. 

The  number  of  movements  re- 
quired to  form  a  row  of  meshes  in 
the  double  tier  machine,  that  is,  in  a 
frame  with  two  combs  or  bars,  and 
2  rows  of  bobbins,  is  six  j^  that  is. 


16 


LACE  MANUFACTURE. 


the  whole  of  the  carrias^es  (with  their  bobbins)  pass  from  one  bar  or  comb  to  the  other 
SIX  times,  durin?  which  passages  llie  different  divisions  of  bobbin  and  warp  threads 
chans^e  their  relative  positions  12  times. 

This  intcrchanse  or  traversing  of  the  carriages  with  their  bobbins,  which  is  the  most 
difficult  thing  to  explain,  but  at  the  same  time  the  most  essential  principle  of  the  lace- 
machme,  may  be  tolerably  well  understood  by  a  careful  study  of  fig.  838  in  which  lhi« 
1*2  3  4  5  6  7  8  9 

838 


LACTIC  ACID. 


17 


***•<' 


ii.  4^1" 


•••ill 


i. 


XE 


Trrp" 

;  I  ,  i  I 

iiill 


C;<DrffO<D 


ik 


(UAin 


1^9 


Simple  hne  I  represents  the  bolts  or  teeth,  the  sign  i  the  back  line  of  carriages,  and  the 
sign  ^  the  front  hne  of  carriages,  h  is  the  front  comb  or  bolt  bar,  and  i  the  back  bolt 
bar.  The  former  remains  always  fixed  or  stationary,  to  receive  the  carriages  as  they  may 
be  presented  to  it  by  the  shogging  of  the  latter.  There  must  be  always  one  odd  carriage 
at  the  end  ;  the  rest  being  in  pairs. 

No.  1  represents  the  carriages  in  the  front  comb  or  bar,  the  odd  carriage  being  at  the 
left  end.      The  back  line  of  carriages  is  first  moved  on  to  the  back  bar  i,  the  odd 
carriage,  as  seen  in  No.  1,  having  been  left  beliind,  there  being  no  carriage  opposite  to 
drive  It  over  to  the  other  comb  or  bar.     The  carriages  then  stand  as  in  No.  2.     The  bar 
I  now  shifts  to  the  left,  as  shown  m  No.  3 ;  the  front  carriages  then  go  over  into  the 
back  bar  or  comb,  as  is  represented  by  No.  4.      The  bar  i  now  shifts  to  the  right,  and 
gives  the  position  No.  5.      The  front  carriages  are  then  driven  over  to  the  front  bar,  and 
leave  the  odd  carriage  on  the  back  bar  at  the  right  end,  for  the  same  reason  as  before 
described,  and  the  carriages  stand  as  shown  in  No.  6.      The  bar  i  next  shifts  to  the  left, 
and  the  carnages  stand  as  in  No.  7  (the  odd  carriaee  bein?  thereby  on  the  back  bar  to 
the  left.)     The  back  carriages  now  come  over  to  the  front  bar,  and  stand  as  in  No.  8. 
1  he  back  bar  or  comb  i  shifts  to  the  right  as  seen  in  No.  9,  which  completes  the  traverse. 
1  he  whole  carriages  with  their  bobbins  have  now  changed  their  position,  as  will  be  seen 
hy  comparing  No.  9  with  No.  1.      The  odd  carriage.  No.  1  6  has  advanced  one  step  to 
the  right,  and  has  become  one  of  the  front  tier ;  one  of  the  back  tier  or  line  <p  has 
advanced  one  step  to  the  left,  and  has  become  the  odd  carriage ;  and  one  of  the  front 
ones  ;>  has  gone  over  to  the  back  line.    The  bobbins  and  carriages  throughout  the  whole 
width  of  the  machine  have  thus  crossed  each  other's  course,  and  completed  the  mesh  of 
net. 

The  carriages  with  their  bobbins  are  driven  a  certain  wav  from  the  one  comb  to  the 
other,  by  the  pressure  of  two  long  bars  (one  for  each)  placed  above  the  level  of  the  comb 
ttntil  they  come  into  such  a  position  that  their  projecting  heels  or  catches  i  Lfis;.  611,  are 
moved  off  by  two  other  long  flat  bars  below,  called  the  locker  plates,  and  thereby  carried 
completely  over  the  interval  between  the  two  combs. 

-  There  are  six  diflerent  systems  of  bobbin-net  machines.  1.  Heathcoatcs  patent 
maehiuo.  2.  Brown's  traverse  warp.  3.  Moriey's  straight  bolt  4.  Clarke's  pusher 
principle,  single  tier,  5.  Leaver's  machine,  single  tier.  6.  Morley's  circular  bolt.  All 
the  others  are  mere  variations  in  the  construction  of  some  of  their  parts.  It  is  a  re- 
markable fact,  highly  honorable  to  the  mechanicsil  judgment  of  the  late  Mr.  Morlc\ 
of  Derby,  that  no  machines  except  those  upon  his  circular  bolt  principle  have  beeu 
found  capable  of  working  successfully  by  mechanical  power. 

^  The  circular  bolt  machine  (comb  with  curved  teeth)  was  used  by  Mr.  Morley,  for  mak- 
ing narrow  breadths  or  edgings  of  lace  immediately  after  its  first  invention,  audit  hsis 
been  regularly  used  by  tlie  trade  for  that  purpose  ever  since,  in  consequence  of  the 
inventor  having  declined  to  secure  the  monopoly  of  it  to  himself  by  patent.  At  that 
time  the  locker  bars  for  driving  across  the  carriages  had  only  one  plato  or  blade.  A 
machine  so  mounted  is  now  called'*  the  single  locker  circular  bolt"  In  the  year 
1824,  Mr.  Morley  added  another  plate  to  each  of  the  locker  bars,  which  was  a  great 
improvement  on  the  machines  for  nmking  plain  net,  but  an  obstruction  to  the  making 
of  narrow  breadths  upon  them.  This  machine  is  now  distinguahed  from  the  former 
by  the  term  "  double  locker."  * 


A  rack  of  lace,  is  a  certain  length  of  work  counted  perpendicularly,  and  contains  240 
.oK^o  ^r.  i,^i^o      Well-made  lace  has  the  meshes  a  little  elongated  in  the  direction  of 


meshes  or  holes, 
the  selvatje. 


*  By  reading  the  above  brief  account  of  Bobbin-net,  in  connecOon  with  the  most  detailed  description 
of  It  in  my  Cotton  Manufactuke  op  Great  Bkitaik,  a  tolerably  clear  conception  of  the  nature  of  this 
iotricate  manufucture  mav  be  obtained. 


r 


\ 


The  term  gauge,  in  the  lace  manufacture,  means  the  number  of  gates,  slits,  or  in- 
lerstices,  in  one  inch  of  the  bolt-bar  or  comb ;  and  corresponds  therefore  to  the  number 
of  bobbins  in  an  inch  length  of  the  double  tier.  Thus,  when  we  say  "  gauge  nine 
points,"  we  mean  that  there  are  nine  gates  with  nine  bobbins  in  one  inch  of  the  comb 
or  bolt-bar.  Each  of  such  bobbins  with  its  carriage  is  therefore  no  more  than  one  ninth 
of  an  inch  thick.  The  common  proportion  or  gauge  up  and  down  the  machine  is  16 
holes  in  the  inch  for  ten  bobbins  transversely.  Circular  bolt  double  tier  machines  can 
turn  off  by  steam  power  fully  360  racks  each  day  of  18  hours,  with  a  relay  o**  superin- 
tendents. 

The  number  of  new  mechanical  contrivances  to  which  this  branch  of  manufactuie  has 
given  rise,  is  altogether  unparalleled  in  any  other  department  of  the  arts.  Since  Mr. 
Heathcote's  first  successful  patent,  in  1809,  a  great  many  other  patents  have  been  granted 
for  making  lace.  In  the  year  1811,  Mr.  Morley,  then  of  Nottingham,  invented  his 
straight  bolt  frame,  more  simple  in  construction,  better  combined,  and  more  easy  in  its 
movements,  than  the  preceding  machines ;  but  the  modest  inventor  did  not  secure  it,  as 
he  might  have  done,  by  patent.  The  pusher  machine  was  invented  in  the  same  year,  by 
Samuel  Mart  and  James  Clark,  also  of  Nottingham.  The  following  year  is  remarkable 
in  the  History  of  the  lace  trade,  for  the  invention  of  the  circular  bolt  machine,  by  Mr. 
Morley — a  mechanism  possessing  all  the  advantages  of  his  straight  bolt  machine,  without 
its  disadvantages. 

Nearly  at  the  same  time  Mr.  John  Leaver  brought  forward  the  lever  machine,  con- 
jointly with  one  Turton,  both  of  New  Radford,  near  Nottingham.  About  the  year  1817 
or  1818,  Mr.  Heathcote  applied  the  rotatory  movemement  to  the  circular  bolt  machine, 
and  mounted  a  manufactory  on  that  plan,  by  mechanical  power,  at  Tiverton,  after  he  and 
his  partner,  Mr.  Boden,  had  been  driven  from  Loughborough,  in  1816,  by  the  atrocious 
violence  of  the  frame-destroying  Luddites. 

Such  has  been  the  progress  of  improvement  and  economy  in  this  manufacture,  that  the 
cost  of  labor  in  making  a  rack,  which  was,  twenty  years  ago,  3s.  6d.y  or  42  pence,  is  now 
not  more  than  one  penny.  The  prices  of  this  beautiful  fabric  have  fallen  in  an  equally 
remarkable  manner.  At  the  former  period,  a  24  rack  piece,  five  quarters  broad,  fetched 
17/.  sterling,  in  the  wholesale  market ;  the  same  is  now  sold  for  7s.  !  The  consequence 
is,  that  in  lace  decoration,  the  maid  servant  may  be  now  more  sumptuously  arrayed  than 
her  mistress  could  afford  to  be  twenty  years  ago. 

LACKER,  is  a  varnish,  consisting  chiefly  of  a  solution  of  pale  shellac  in  alcohol 
tinged  with  saftron,  annolto,  or  other  coloring  matter.     See  Varnish. 

LACTIC  ACID.  (./Icide  Lactiqne,  Ft.;  Milchsaiire,  Germ.)  This  acid  was  discovered 
by  Scheele  in  buttermilk,  where  it  exists  most  abundantly ;  but  it  is  present  also  in  fresh 
milk  in  small  quantity,  and  communicates  to  it  the  property  of  reddening  litmus.  Lactic 
acid  may  be  detected  in  all  the  fluids  of  the  animal  body  ;  either  free  or  saturated  with 
alkaline  matter. 

Scheele  obtained  this  acid  by  evaporating  the  sour  whey  of  clotted  milk  to  an  eighth 
part  of  its  bulk,  saturating  this  remainder  with  slaked  lime,  in  order  to  throw  down  the 
subphosphate  of  lime  held  in  solution,  filtering  the  liquor,  diluting  it  with  thrice  its  weight 
of  water,  and  precipitating  the  lime  circumspectly,  by  the  gradual  addition  of  oxalic  acid. 
He  next  filtered,  evaporated  to  dryness  on  a  water  batli,  and  digested  the  residuum 
in  strong  alcohol,  which  dissolved  the  lactic  acid,  and  left  the  sugar  of  milk.  On  eva- 
porating off  the  alcohol,  the  acid  was  obtained.  As  thus  procured,  it  requires  to  be 
purified  by  saturation  with  carbonate  of  lead  (pure  white  lead),  and  precipitating  the 
solution  of  this  lactate  with  sulphate  of  zinc,  not  added  in  excess.  Sulphate  of  lead 
falls,  and  t!ie  supernatant  lactate  of  zinc  being  evaporated  affords  crystals  at  first  brown, 
but  which  become  colorless  on  being  dissolved  and  recrystallized  twice  or  thrice.  It* 
the  sulphuric  acid  of  the  dissolved  salt  be  thrown  down  by  water  of  baryta,  the  liquid 
when  filtered  and  evaporated  yields  a  pure  lactic  acid,  of  a  syrupy  consistence,  color- 
less and  void  of  smell.  It  has  a  pungent  acid  taste,  which  it  loses  almost  entirely  when 
moderately  diluted  w^ith  water.  It  does  not  crystallize.  Its  salts,  with  the  exception 
of  those  of  magnesia  and  zinc,  have  a  gummy  appearance,  and  are  very  soluble  in 
alcohol,  unless  they  hold  an  excess  of  base.  Lactic  acid  consists  of  44*92  carbon  ;  6*65 
hydrogen;  48"53  oxygen.  It  contains  9*92  per  cent,  of  water.  It  has  not  hitherto 
been  applied  to  any  use  in  the  arts,  except  by  the  Dutch  in  their  old  process  of  bleach- 
ing linen  with  sour  milk.     See  Fermentation.  ' 

New  method  of  preparing. — The  following  process  for  procuring  lactic  acid  and  the 
lactates  is  so  simple,  as  to  merit  a  preference  over  all  others  heretofore  proposed ; 
it  is  as  follows: — "Take  3  or  4  (litre  =  1*76  pint)  of  milk,  into  which  you 
pour  a  solution  of  from  200  to  300  grammes  (gramme  =»  15*438  grs.  Troy)  of 
sugar  of  milk ;  the  liquor  is  exposed  to  the  air  in  an  open  vessel  for  some  days,  at 
a  temperature  of  from  59°  to  68°  Fahr.  It  will  then  be  found  to  have  become  very 
acid,  and  is  to  be  saturated  with  bicarbonate  of  soda.     After  the  lapse  of  24  or 

Vol.  II.  2 


18 


LAKES. 


LAMPS. 


!• 


86  hours  it  becomes  again  acid,  and  must  be  saturated  anew,  repeatine  the  oroce*- 

until  the  whole  of  the  sugar  of  milk  has  been  converted  into  lactKdd^     Whe^^^^^^^ 

consi.lered  that  the  transformation  is  complete,  the  milk  must  be  boTled  tola^late 

the  caseura ;  the  hqtud  is  next  to  be  filtered  and  evaporated  to  the  consistence  of  s^ruD 

taking  care  that  the  temperature  be  moderate.     The  product  of  evaporat  onTs  taSn  ud 

by  alcohol  at  38°  which  d.ssolves  the  lactate  of  sodk     Into  this  alcoSsoluton  an 

adequate  quantity  of  sulphimc  acid  is  to  be  poured ;  the  resulting  sulphate  of  soda  fa  Is 

down   and  the  hquor  by  filtration  and  evaporation   affords  lactic  Lklarinosrimre 

To  obtam  It  m  a  state  of  great  purity,  it  may  be  saturated  with  chalk     the^acfUe  of 

hme  crystallizes  directly  in  white  granules,  whence  we  can  separate  th^  lac'tic  add  by 

the  ordinary  means.  «v.i,iv.  uv^iu  uy 

It  is  evident  the  lactic  acid  may  be  saturated  with  any  other  base,  and  afford  exDe- 
ditiously  crystallized  lactates.  ^  «*  u  auora  expe- 

..^^F^?^^^^^^  '!  *^'^  '''"^?  ""^^^  instrument  for  estimating  the  quality  of  milt 
called  also  a  Galactmneter.  The  most  convenient  form  of  apparatus  would  be  a 
senes  of  glass  tubes  each  about  1  inch  in  diameter,  and  12  inches  lonrffraduated 
through  a  space  of  10  inches,  to  tenths  of  an  inch,  having  a  stop-cock  at^'lfebo"^^^^^^ 
and  suspended  upright  in  a  frame.  The  average  milk  of  the  cow  Sg  no  red  ^To 
the  height  of  10  inches,  as  soon  as  the  cream  has  all  separated  at  top  the  thickness  of 
ite  body  maybe  measured  by  the  scale;  and  then  the  skim-milk  may  be  run  off 
below  into  a  hydrometer  glass,  in  order  to  determine  its  density,  or  relative  I'ichness 
in  caseous  matter,  and  dilution  with  water.  ^        ^cxauve  iiciiness 

LAKES.  Under  this  title  are  comprised  all  those  colors  which  consist  of  a  ve^-etable 
dye,  combined  by  precipitation  with  a  white  earthy  basis,  which  is  usually  alumina''  The 
general  method  of  preparation  is  to  add  to  the  colored  infusion  a  solution  of  common 
alum  or  rather  a  solution  of  alum  saturated  with  potash,  especially  when  the  infusion 
has  been  made  with  the  aid  of  acids.  At  first  only  a  slight  precipitate  falls,  consisting 
of  alumina  and  the  coloring  matter ;  but  on  adding  potash,  a  copious  precipitation  ensues! 
of  the  alumina  associated  with  the  dye.  When  the  dyes  are  not  injured,  but  are  rathe^ 
brightened  by  alkalis,  the  above  process  is  reversed  ;  a  decoction  of  the  dye-stuff  is  made 
with  an  aUiahne  liquor,  and  when  it  is  filtered,  a  solution  of  alum  is  poured  into  it.  The 
third  method  IS  practicable  only  with  substances  having  a  great  affinity  for  subsulphate 
^^a^umina  ;  it  consists  m  agitating  recently  precipitated  alumina  with  the  decoction  of 

yellow  /«fec5  are  made  with  a  decoction  of  Persian  or  French  berries,  to  which  some 
potash  or  soda  is  added;  into  the  mixture  a  solution  of  alum  is  to  be  poured  as  long  as 
any  precipitate  faUs.  The  precipitate  must  be  filtered,  washed,  and  formed  into  cakes, 
and  dried.  A  lalce  may  be  made  in  the  same  way  with  quercitron,  takin?  the  precautioi 
to  purify  the  decoction  of  the  dye-stuff  with  buttermilk  or  due.  After  filtering  the  lake 
ivfc^L-  ^"?h^\"e^,^^;th  a  solution  of  tin.  Annotto  lake  is  formed  by  dissolving  the 
dye-stufi  m  a  weak  alkahne  ley,  and  addmg  alum  water  to  the  solution.  Solution  of  tin 
gives  this  lake  a  lemon  yellow  cast ;  acids  a  reddish  tint. 

Hcd  lakes.— The  finest  of  these  is  carmine. 

This  beautiful  pigment  was  accidentaUy  discovered  by  a  Franciscan  monk  at  Pisa.  He 
«nTl  ''■''  f  I  ""^  cochmeal  With  salt  of  tartar,  in  order  to  employ  it  as  a  medicine! 
«  nrn .  .  r  '  ""  ^^^^^^^.^^lou  of  an  acid  to  it,  a  fine  red  precipitate.  Homberg  published 
n/rp/  h.  Z  preparing  It,  m  I6dG.  Carmine  is  the  coloring  matter  of  cochineal,  pre- 
fhJ  1h^  precipitation  from  a  dcccction  of  the  drug.  Its  composition  varies  according  to 
the  mode  of  making  it.  The  ordinary  carmine  is  prepared  with  alum,  and  consists  of 
clZT^  ^'"^  Cochineal),  a  Httle  animal  matter,  almnina,  and  sulphuric  acid.      S^e 

Ca-minated  lake  caUed  lake  of  Florence,  Paris,  or  Vienna.  For  making  this  pigment. 
tJl^Zo' .f  "^^ly  ^"^P^^y^'l  ^l^i^\is  decanted  from  the  carmine  process.  Imf tM^ 
mul^  ^  Whl        ^^^'?  '  •  P"l'  ^^!  °^^^r  ^'  ''^'^'  ^"^  h^^t^d\i  little,  but  not  too 

to^h^owdowrflr  ^'^^^'^^^"^  in  the  decoction  of  cochineal,  and  potash  is  then  added, 
Wiff^ZJ  '  ^^^^^^.""^i'^^^"  combination  with  the  coloring  matter;  but  in  this  way  an 
indiiierent  pigment  is  oblamed.      OccasionaUy,  solution  of  tin  is  added,  to  brighten  the 

is  feWom  L'/r'e^otsf  t'o'  '""  """^''^  "  ''^  '''''  "^^  ^^  '^^'^  ^^'^^^'^^^^ ''  »^"^  ^'^  " 
Brazil-xoood  Zafr^s.— Brazil  wood  is  to  be  boiled  in  a  proper  quantitv  of  water  for  13 

Z^Z  'o/t"t;.t"  -V°^"^"?  ''  ^^^^^^^  ^''^'^  the^i?uor^s  t^be  fiUered,  a^^j'a 
solution  of  potash  poured  in  as  long  as  it  occasions  a  precipitate.     This  is  separalea  by 


the  filter,  washed  in  pure  water,  mixed  with  a  little  gum  neater,  and  made  into  cakes. 
Or  the  BrazQ  wood  may  be  boiled  along  with  a  little  vinegar,  the  decoction  filtered,  alum 
and  salt  of  tin  added,  and  then  potash-ley  poured  in  to  precipitate  the  lake.  For  1  pound 
of  Brazil  wood,  30  to  40  pounds  of  water,  and  from  1^  to  2  pounds  of  alum,  may  be  taken, 
in  producing  a  deep  red  lake ;  or  the  same  proportions  with  half  a  pound  of  solution  of 
tin.  If  the  potash  be  added  in  excess,  the  tint  will  become  violet.  Cream  of  tartar 
occasions  a  brownish  cost.  .    . 

Madder  lake.— A  fine  lake  may  be  obtained  from  madder,  by  washing  it  in  cold  water 
as  long  as  it  gives  out  color;  then  sprinkling  some  solution  of  tin  over  it,  and  setting  it 
aside  for  some  days.  A  gentle  heat  may  also  be  applied.  The  red  liquor  must  be  then 
separated  by  the  filter,  and  decomposed  by  the  addition  of  carbonate  of  soda,  when  a  fine 
red  precipitate  will  be  obtained.  Or,  the  reddish  brown  coloring  matter  of  a  decoction 
of  madder  may  be  first  separated  by  acetate  of  lead,  and  then  the  rose  red  color  with  alum. 
Or,  madder  tied  up  in  a  bag  is  boiled  in  water ;  to  the  decoction,  alum  is  added,  and  then 
potash.  The  precipitate  should  be  washed  with  boiling  water,  till  it  ceases  to  tinge  it 
yellow;  and  it  is  then  to  be  dried. 

The  following  process  merits  a  preference :  •        e  ^n 

Diffuse  2  pounds  of  ground  madder  in  4  quarts  of  water,  and  after  a  maceration  of  10 
minutes,  strain  and  squeeze  the  grounds  in  a  press.  Repeat  this  maceration,  &c.  twice 
upon  the  same  portion  of  madder.  It  will  now  have  a  fine  rose  color.  It  must  then  be 
mixed  with  5  or  6  pounds  of  water  and  half  a  pound  of  bruised  alum,  and  heated  upon 
a  water  bath  for  3  or  4  hours,  with  the  addition  of  water,  as  it  evaporates,  aftex  which 
the  whole  must  be  thrown  upon  a  filter  cloth.  The  liquor  which  passes  is  to  be  filtered 
through  paper,  and  then  precipitated  by  carbonate  of  potash.  If  the  pota?h  be  added  m 
three  "successive  doses,  three  different  lakes  will  be  obtained,  of  successively  diminishing 
beauty.     The  precipitates  must  be  washed  till  the  water  comes  off  colorless. 

Bhie  lakes  are  hardly  ever  prepared,  as  indigo,  Prussian  blue,  cobalt  blue,  and  ultra^ 
marine,  answer  every  purpose  of  blue  pigments. 

Green  lakes  are  made  by  a  mixture  of  yellow  lakes  with  blue  pigments ;  but  chrome 
mellows  mixed  with  blues  produce  almost  all  the  requisite  shades  of  green. 

LAM  IN  ABLE  is  said  of  a  metal  which  may  be  extended  by  passing  between  steel  or 
hardened  (chilled)  cast-iron  rollers. 

For  a  description  of  metal  rolling  presses,  see  Iron  and  Mint  ;  and 

For  a  table  of  the  relative  laminability  of  metals,  see  Ductility. 

LAMIUM  ALBUM,  or  the  dead  nettle,  is  said  by  Leuchs  to  afford  in  its  leaves  a 
greenish-yellow  dye.  The  L.  purpureum  dyes  a  reddish-gray  with  salt  of  tin,  and  a 
greenish  tint  with  iron  liquor. 

LAMPS  differ  so  much  in  principle,  form,  and  construction,  as  to  render  their  descrip- 
tion impossible,  as  a  general  subject  of  manufacture.  In  fact,  the  operations  of  the 
lampisl,  like  those  of  the  blacksmith,  cabinet-maker,  cooper,  coppersmith,  tinman, 
turner,  &c.,  belong  to  a  treatise  upon  handicraft  trades.  I  shall  here,  however,  intro- 
duce a  tabular  view  of  the  relative  light  and  economy  of  the  lamps  most  genei-ally 
known. 


I 


Kind  of  Lamps. 

Intensity  of  light  during 

Mean  of 
7  hours. 

Consump- 
tion per 
hour  in 

grammes. 

Light  from 

100  parts 

of  oil. 

1 
hour 

2 

liMurs 

3 

hours 

4 

hours 

5 

hours 

6 

hours 

1.  Mechanical  lamp  of 
Carcel 

100 

42 

238 

2.  Fountain    lamp,   ^ 

and  a  chimney   > 
with  flat  wick    ) 

3.  Dome  argand 

4.  Sinumbra  lamp 

5.  Do.    with  fountain 

above 

100 

103 
102 

100 

98 

90 
95 

90 

98 

72 
83 

70 

97 

61 
81 

52 

96 

42 
78 

41 

96 

34 
66 

32 

125 

31 
56 

85 

11 

26-714 
37-145 

43 

113 

116 
150 

197 

6.  Do.    with  another 
beak  -        -        . 

100 

97 

95 

92 

89 

86 

41 

18 

227 

7.  Girard's  hydrostatic 
lamp  -         -         - 

101 

96 

84 

81 

76 

70 

63-66 

34-714 

182 

8.  Thilorier'sorPar-  ) 
ke!'s  hydrosta-  > 

106 

103 

100 

94 

92 

90 

107-66 

51-143 

215 

tic  lamp    -         ) 

/ 


%Q 


LAMPS. 


LAMP  OF  DAVY. 


tl 


( ' 


* 


^  In  the  above  table,  for  the  purpose  of  comparing  the  successive  degrees  of  intensity 
100  represents  the  mean  intensity  of  light  during  the  first  hour.  The  quantity  of  oUcw 
^ZilZr?Z!^  ^^^^  'a  ^\°^"^^,^»  ""^  ^H  grains  each.  The  last  column  expresses  the 
l^^^l  ^ght  produced  with  a  like  consumption  of  oil,  which  was  in  all  cases  100 
grammes,    oee  Candles. 


The  foUowing  table  of  M.  Peclet  is  perhaps  more  instructive :— 


r 


Nature  of  the  light. 


Intensity. 


1.  Mechanical  lamp 

2.  Flat-wick  mechan.  do. 

3.  Hemispherical    dome 
lamp    - 

4.  Sinumbra  lamp 
Do.  with  a  lateral  foun- 
tain or  vase  - 

Do.  with  a  fountain 
above  -        -        . 

Girard's  hydrostatic 
lamp    -        _        _ 

Thilorier's  or  Parker's 
lamp    -        »        . 

Candle,  6  in  lb. 
Do.     8  in  lb. 
Do.     6  with  smaller 
wick  -        .        . 

Wax  candle,  5  in  lb. 

Sperm  candle,      do. 

14.  Stearine  candle,   do. 

15.  Coal  gas  -        -        - 
116.  Oil  gas     -        -        _ 


5. 


6. 
7. 

8. 

9. 
10. 
11. 

12. 
13. 


100 
12-05 

31-0 

85 

41 

90 

63*66 

107-66 

10-66 

8-74 

7-50 
13-61 
14-40 
14-30 

127 

127 


Consump- 
tion per 
hour  in 

grammes. 


42 
11 

26-714 
43 

18 

43 

34-71 

51-143 
8-51 
7-51 

7-42 
8-71 
8-92 
9-35 
136  litres 
136  do. 


Cost 


per  kilo- 
gramme. 


francs. 

1-40 
1-40 

1-40 
1-40 

1-40 

1-40 

1-40 

1-40 
1-40 
1-40 

2-40 

7-60 
7-60 
6-OU 


of  light 
per  hour. 


cents. 

5-8 

15 

3-7 
60 

2-5 

6-0 
4-8 


Fat  pro- 
ducing the 
same  light. 


Cost 
per  hour. 


grammes. 

42 
88 

86-16 
50-58    I 
I 
43-90 

47-77 

54-52 


cents. 

5-8 
12-3 

120 
70 

61 

6-6 

7-6 


I 


7-1 

47-5 

6-6 

1-2 

70-35 

9-8 

1-0 

85-92 

12-0 

1-7 

98-93 

23-7 

5-7 

6404 

48  6 

5-8 

61-94 

47-8 

5-5 

65-24 

37-1 

50 

107  litres 

3-9 

5-0 

30 

3-9     J 

.J^%  ^IS^K""^  *^^  mechanical  lamp  is  greatly  over-rated  relatively  to  that  of  iras  Th^ 
Th"/wH-  "'"'''  V  ^'t  ^V^"^''  greate/ than  of  the  latter,  l/London  ^  ^' 
ofTnrnPnfl  ^  ^°Tk  ^^  Under  this  title,  is  tho  construction  of  lamps  for  bu;ning  spirits 
of  turpentine  m  the  place  of  the  fat  oils  which  alone  have  been  in  use  from  th^^ZlJ 
remote  ages  down  to  the  present  time.  Several  patents  have  Recently  be^n  obtared 
for  these  lamps,  under  the  fantastic  title  of  Camphine ;  one  bHlr  Wm^^^^^^ 
and  another  by  Messrs.  Rayner  and  Carter,  as  the  in  vention  oil  woiking  mker-R^ 
forr^^n.  f'^?  ^''"  employed  by  the  proprietors  of  these  patents  to  eSne  the  Pe^ 
Ireroc^^l's':!!!^"^"^^^^  ^^°^P^'  ^  ^^-  --^  *^«  ^-o -P-ta  drawn  up^'LTn 

eauaUo  ve'rt^^^rf^'f^'' i"^"^  ^'^^  '^  "*°^*^'^  brilliancy,  without  smoke,  emits  a  light 
equal  to  very  nearly  twelve  wax  or  sperm  candles  of  three  or  four  to  the  pound  and 
m  so  doing  It  consumes  exactly  one  imperial  pint  of  spirits  of  turpentkH value  she 

i^on/h  Tf^  '°  ^''^  ^r'^ '  ^T'^  '^^  «°^*  P«^  ^^"^  ^^'  « ligl^t  equal?otenuch  candles 
IS  one  halfpenny;  whereas  that  from  wax  candles  would  be  nearly  sixpence      fr^^ 
8pe,^aceti  ditto  fivepence;    from  stearine  ditto,  fourpence;    from  Palmer's  sn^^^ 
^^^:^^\^'::^^:Z'^i   fromtallowmoulds,li<.;    from  sp^rt^,!!  inTatl? 

^:ii:^^:;;^V^^^  '-'-'  «^^^^  ^e=-^ed  hues^trJletthl 

gr^a'llw^Sef  than  thrnf  T  ""^''^'^  ""TS  ^'^^*  '«  ^^^"^^^  ^^  *^«  ^^^^^  ^amp,  is 
to  be  LcounteV?^^^^^^^  tT\^^  ^''  ^'^'\^  ^"^"^T  ^^  "^""^  ^^^^^^^^^^^ '  *  circumstance 
pentLe  aTfat  oHs  tT.  «n;  f  '\"'  ^/!^"?^«al/o°^Position  between  spirits  of  tur- 
penune  ajia  lat  oils.     The  spirits  consist  entirely  of  carbon  and  hydrotren  -  in  the  nro- 

8^^322  nart  of  n  ^''°'''* '^r^"''  *"^  Hi  of ^the  latter,  in  100  ^^^akd  thet  ^ot 
sume  328  parte  of  oxygen;  whereas  sperm  and  other  unctuous  oils  consist  of  78  narL 
of  carbon.  11*  of  hydrogen,  and  lOi  of  oxygen,  in  100  parts;  and  Jherconsume  only 


287-2  of  oxygen,  in  being  burnt;  because  the  oxygen  already  present  m  the  oil  neti. 
Jralizes  2^  parts  of  the  cSrbon  and  0-4  of  the  hydrogen,  thus  leaving  only  85*  parta  of 
ihe  combustible  elements  for  the  atmosphere  to  burn.  For  this  reason.  87*  parts  by 
weiffM  of  spirits  of  turpentine,  will  consume  as  much  oxygen  as  100  parts  of  sperm 
oil-  and  will  afford,  moreover,  a  more  vivid  light,  because  they  contain  no  oxide,  as  fat 
oils  do  which  serves  to  damp  the  combustion.  In  the  spirits  of  turpentine,  the  affinity 
of  ite  elements  for  oxygen  is  entire,  whereas  in  fat  oil  the  affinity  is  partially  ne^utral- 
ized  by  the  oxides  it  contains ;   somewhat  as  the  flame  of  spirits  of  wine  is  weakened 

bv  their  dilution  with  water.  ,  .  ,  xi  *. 

"  Among  the  many  applications  of  science  to  the  useful  arts,  for  which  tiie  present 
age  is  so  honorably  distinguished,  few  are  more  meritorious  than  the  Camphine  lamps, 
bv  which  we  can  produce  a  snow-white  flame  from  the  cleanly,  colorless  spirit*  of  tur- 
pintine— a  pure  combustible  fluid,  in  place  of  the  smeary  rank  oils  which  contain  a 
seventh  part  of  incombustible  matter.  Being  so  rich  in  hydro-carbon,  "^e  spirits  re- 
auire  peculiar  artifices  for  complete  consumption  and  the  development  of  their  full 
power  of  yielding  light  without  smoke  or  smell.  This  point  of  perfection  seems  to  be 
happily  attained  by  the  invention  of  the  two  parallel  flat  ringd  in  the  Paragon  lamjfc 
a  lareer  and  smaller,  forming  a  cone  round  the  margin  of  the  wick,  which  cause  a  rapid 
revel  beratiori  of  the  air  against  the  flame :  thus  consuming  every  particle  of  volatilized 
vapor  and  adding  energy  to  the  luminous  undulations.  Hence  the  patent  Paragon 
lamp  in  full  action  emits  a  light  equal  to  that  of  sixteen  wax-candles  three  to  the 
pound,  but  of  better  quality,  approaching  in  purity  to  that  of  the  sun-beam  —there- 
fore capable  of  displaying  natural  and  artificial  objects  in  their  true  colors.     But  these 

lamps  are  very  apt  to  smoke.  ,      .  .,      -n  x.        r^- 

"One  imperial  pint  of  rectified  spirits  of  turpentine,  value  6(i  retail,  will  burn  for 

twelve  hours  in  this  lamp,  affording  all  the  time  the  illumination  of  eleven  wax-candlea. 
"  The  Paragon  Camphine  lamp  is  attended  with  no  danger  in  use. 
"The  Cost,  as  compared  with  other  Lamps  or  Candles,  is  as  follows:  viz.— 

PER   HOUB. 

Paragon  Camphine  Lamp  (equal  to  11  wax  candles),  less  than  One  Halfpenny. 
Wax  Candles    -------- 

Spermaceti  ditto  "."'"'"' 

Adamantean  Wax  (Stearic  Acid)         -  -  -  -  - 

Palmer's  Spread-Wick  Candles  .  -  -  -  - 

Cocoa  Nut  Candles      ------- 

Moulds  (Tallow)  ------- 

.  Carcel'a  Lamp,  with  Sperm  oil  -  -  -  -  " 

Bee  Illumination,  Cost  of.  for  a  description  of  an  excellent  oil  lamp. 

LAMP  OF  DAVY  consists  of  a  common  oil  lamp,  surmounted  with  a  covered 
839  cylinder  of  wire  gauze,  for  transmitting  light  to  the  miner  >^ithout 

endangering  the  kindling  of  the  atmosphere  of  fire-damp  which 
may  surround  him;  because  carbureted  hydrogen,  m  passmg 
through  the  meshes  of  the  cylindric  cover,  gets  cooled  by  the  con- 
ducting power  of  the  metallic  gauze,  below  the   point  of  its 

accension.  -•  on  v    r 

The  apertures  in  the  gauze  should  not  be  more  than  1  .iOtti  of 
an  inch  square.  Since  the  fire  damp  is  not  inflamed  by  ignited 
wire,  the  thickness  of  the  wire  is  not  of  importance,  but  wire  from 
l-40lh  to  l-60th  of  an  inch  in  diameter  is  the  most  convenient. 

The  cage  or  cylinder  should  be  made  by  double  joinings,  the 

gauze  being  folded  over  in  such  a  manner  as  to  leave  no  apertures. 

Q     When  it  is  cylindrical,  it  should  not  be  more  than  two  inches  m 

diameter ;  because  In  larger  cylinders,  the  combustion  of  the  fire- 

damp  renders  the  top  inconveniently  hot ;  a  double  top  is  always 

a  proper  precaution,  fixed  f  or  f  of 
an  inch  above  the  first  top.    See 

fig*  839. 

The  gauze  cylinder  should  be 
fastened  to  the  lamp  by  a  screw  b, 
fig.  840.  of  four  or  five  turns,  and 
fitted  to  the  screw  by  a  tight  ring. 
All  joinings  in  the  lamp  should  be 
made  with  hard  solder ;  as  the  secu- 
rity depends  upon  the  circumstance 
that  no  aperture  exists  in  the  appa- 
ratus larger  than  in  the  wire-gauze. 


6*d 

6f 

4i 

3* 

4f 

2f 

2" 


840 


22 


LAMP  OF  DAVY. 


The  parts  of  the  lamp  are, 

1.  The  brass  cistern  a,  d,fig,  840,  which  contains  the  oil.  It  is  pierced  at  one  side  of 
the  centre  with  a  vertical  narrow  tube,  nearly  filled  with  a  wire  which  is  recun'ed  above, 
at  the  level  of  the  burner,  to  trim  the  wick,  by  acting  on  the  lower  end  of  the  wire  e  with 
the  fingers.     It  is  called  the  safety-trimmer. 

2.  The  rim  b  is  the  screw  neck  for  fixing  on  the  gauze  cylinder,  in  which  the  wire- 
gauze  cover  is  fixed,  and  which  is  fastened  to  the  cistern  by  a  screw  fitted  to  h. 

3.  An  aperture  c  for  supplying  oil.  It  is  fitted  with  a  screw  or  a  cork,  and  communi- 
cates with  the  bottom  of  the  cistern  by  a  tube  at/.     A  central  aperture  for  the  wick. 

4.  The  wire-gauze  cylinder, y/g.  839,  which  should  not  have  less  than  625  apertares  to 
the  square  inch. 

6.  The  second  top,  £  of  an  inch  above  the  first,  surmounted  by  a  brass  or  copper  plate, 
to  which  the  ring  of  suspension  may  be  fijced.  It  is  covered  with  a  wire  cap  in  the 
figure. 

6.  Four  or  six  thick  vertical  wires,  g'  g'  g'  g',  joining  the  cistern  below  with  the  lop 
plate,  and  serving  as  protecting  pillars  round  the  cage,  g  is  a  screw-pin  to  fix  the  cover, 
so  that  it  shall  not  become  loosened  by  accident  or  carelessness.  The  oil-cistern  fig.  840 
is  dr^wn  upon  a  larger  scale  Ihan/g.  839,  to  show  its  minuter  parts. 

When  the  wire-gauze  safe-lamp  is  lighted  and  introduced  into  an  atmosphere  gradually 
mixed  with  fire-damp,  the  first  effect  of  the  fire-damp  is  to  increase  the  length  and  size 
of  the  flame.  When  the  inflammable  gas  forms  so  much  as  l-12th  of  the  volume  of  th- 
air,  the  cylinder  becomes  filled  with  a  feeble  blue  flame,  while  the  flame  of  the  wick  ^ 
appears  burning  brightly  within  the  blue  flame.  The  light  of  the  wick  augments  till  the 
fire-damp  increases  to  l-6th  or  I-5th,  when  it  is  lost  in  the  flame  of  the  fire-damp,  which 
in  this  case  fills  the  cylinder  with  a  pretty  strong  light.  As  long  as  any  eaplosire  mixture 
of  gas  exists  in  contact  with  the  lamp,  so  long  it  will  give  light ;  and  when  it  is  extinguished, 
which  happens  whenever  the  foul  air  constitutes  so  much  as  l-3d  of  the  volume  of  the 
atmosphere,  the  air  is  no  longer  proper  for  respii  alion ;  for  though  animal  life  will  con- 
tinue where  flame  is  extinguished,  yet  it  is  always  with  suflering.  By  fixing  a  coil  of 
platinum  wire  above  the  wick,  ignition  may  be  nraintained  in  the  metal  when  the  lamp 
itself  is  extinguished ;  and  from  this  ignited  wire  the  wick  may  be  again  rekindled,  on 
carrying  it  into  a  less  inflammable  atmosphere. 

«  We  have  frequently  used  the  lamps  where  the  explosive  mixture  was  so  high  as  to 
heat  the  wire-gauze  red-hot ;  but  on  examining  a  lamp  which  has  been  in  constant  use 
for  three  months,  and  occasionally  subjected  to  this  degree  of  heat,  I  cannot  perceive  that 
the  gauze  cylinder  of  iron  wire  is  at  all  impaired.  I  have  not,  however,  thought  it  pru- 
dent, in  our  present  state  of  experience,  to  persist  in  using  the  lamps  under  such  circum- 
stances, because  I  have  observed,  that  in  such  situations  the  particles  of  coal  dust  floating 
in  the  air,  fire  at  the  gas  burning  within  the  cylinder,  and  fly  ofl'  in  small  luminous  sparks. 
This  appearance,  I  must  confess,  alarmed  me  in  the  first  instance,  but  experience  soon 
proved  that  it  was  not  dangerous. 

"  Besides  the  facilities  aflorded  by  this  invention  to  the  working  of  coal-mines  abound- 
ing in  fire-damp,  it  has  enabled  the  directors  and  superintendents  to  ascertain,  with  thf 
utmost  precision  and  expedition,  both  the  presence,  the  quantity,  and  correct  situation  of 
the  gas.  Instead  of  creeping  inch  by  inch  with  a  candle,  as  is  usual,  along  the  galleries 
of  a  mine  suspected  to  contain  fire-damp,  in  order  to  ascertain  its  presence,  we  walk  firmly 
on  with  the  safe-lamps,  and,  with  the  utmost  confidence,  prove  the  actual  state  of  the 
mine.  By  observing  attentively  the  several  appearances  upon  the  flame  of  the  lamp,  in 
an  examination  of  this  kind,  the  cause  of  accidents  which  happened  to  the  most  experienced 
and  cautious  miners  is  completely  developed ;  and  this  has  hitherto  been  in  a  great  meas- 
ure matter  of  mere  conjecture. 

« It  is  not  necessary  that  I  should  enlarge  upon  the  national  advantages  which  must 
necessarily  result  from  an  invention  calculated  to  prolong  our  supply  of  mineral  coal, 
because  I  think  them  obvious  to  every  reflecting  mind ;  but  I  cannot  conclude  without 
expressing  my  highest  sentiments  of  admiration  for  those  talents  which  have  developed 
the  properties,  and  controlled  the  power,  of  one  of  the  most  dangerous  elements  which 
human  enterprise  has  hitherto  had  to  encounter." — See  Letter  to  Sir  H.  Davy,  in  Journal 
of  Science,  vol.  i.  p.  302,  by  John  Buddie,  Esq.,  generally  and  justly  esteemed  one  of  the 
most  scientific  coal-miners  in  the  kingdom. 

Mr.  Buddie,  in  a  letter  dated  21st  August,  1835,  which  is  published  in  Dr.  Davy's  life 
of  his  brother  Sir  Humphrey,  says  : — 

"  In  the  evidence  given  in  my  last  examination  before  a  committee  of  the  House  of 
Commons,  I  stated  that  after  nearly  twenty  years'  experience  of  *  the  Davy'  with  from 
1000  to  1500  lamps  in  daily  use,  in  all  the  variety  of  circumstances  incidental  to 
coal  mining,  without  a  single  accident  having  happened  which  could  he  atiributed  to 


LAMPATES. 

a  defect  in  its  principle,  or  even  in  the  rules  for  its  practical  application,  as  laid  down  by 
Sir  Humphrey--I  maintained  that  '  the  Davy'  approximated  perfection,  as  nearly  as  any 
instrument  of  human  invention  could  be  expected  to  do.  We  have  ascertained  distinctly 
that  the  late  explosion  did  not  happen  in  that  part  of  the  mine  where  l^^^  Davys  were 
used.  They  were  all  found  in  a  perfect  stale  after  the  accident— many  of  them  in  Uie 
hands  of  the  dead  bodies  of  the  suflierers." 

LAMP-BLACK.     See  Black.  .     .      ,         ^      •.       ..         •  t 

LAMPATFS  and  LAMPIC  ACID.  When  a  spirit  of  wine  lamp  has  its  cotton  wick 
surmounted  with  a  spiral  coil  of  platinum  wire,  after  lighting  it  for  a  little,  it  may  be 
blown  out,  without  ceasing  to  burn  the  alcohol ;  for  the  coil  continues  ignited,  and  a  cur- 
rent of  hot  vapor  continues  to  rise,  as  long  as  the  spirit  lasts.  This  vapor  was  first  con- 
densed and  examined  by  Professor  Daniell,  who  called  it  lampic  acid.  It  has  a  peculiar, 
strondy  acid,  burning  taste,  and  a  spec.  grav.  of  1-015.  It  possesses  in  an  emment  tie- 
gree  the  property  of  reducing  certain  metallic  solutions ;  such  as  those  of  platinum,  goia, 
and  silver.     The  lampates  may  be  prepared  by  saturating  the  above  acid  with  the  alkaline 

and  earthy  carbonates.  -      .  .  v  v        „„j 

LAPIDARY,  Jrt  of.  The  art  of  the  lapidary,  or  that  of  cutting,  polishing,  and 
engraving  gems,  was  known  to  the  ancients,  many  of  whom  have  left  admirable  specimens 
of  their  skill.  The  Greeks  were  passionate  lovers  of  rings  and  engraved  stones ;  and  the 
most  parsimonious  among  the  higher  classes  of  the  Cyrenians  are  said  to  have  worn  rings 
of  the  value  of  ten  minse  (about  30Z.  of  our  money.)  By  far  the  greater  part  of  the  antique 
gems  that  have  reached  modern  times,  may  be  considered  as  so  many  models  lor  terming 
the  taste  of  the  student  of  the  fine  arts,  and  for  inspiring  his  mind  with  correct  ideas  ol 
what  is  trulv  beaulifuL  With  the  cutting  of  the  diamond,  however,  the  ancients  were 
unacquainted,  and  hence  they  wore  it  in  its  natural  state.  Even  in  the  middle  ages,  this 
art  was  still  unknown  ;  for  the  four  large  diamonds  which  enrich  the  clasp  ol  the  impenal 
mantle  of  Charlemagne,  as  now  preserved  in  Paris,  are  uncut,  octahedral  crystals.  But 
the  art  of  working  diamonds  was  probably  known  in  Hindostan  and  China,  in  very  remote 
periods.  After  Louis  de  Berghen's discovery,  in  1476,  of  polishing  two  diamonds  by  their 
mutual  attrition,  all  the  finest  diamonds  were  sent  to  Holland  to  be  cut  and  polished  by 
the  Dutch  artists,  who  long  retained  a  superiority,  now  no  longer  admitted  by  the  lapida- 
ries of  London  and  Paris.  o  v        . 

The  operation  of  gem  cutting  is  abridged  by  two  methods ;  1.  by  cleavage  ;  i.  by  cut- 
ting oflf  slices  with  a  fine  wire,  coated  with  diamond  powder,  and  fixed  m  the  stock  of  a 
hand-saw.  Diamond  is  the  only  precious  stone  which  is  cut  and  polished  with  diamond 
powder,  soaked  with  olive  oil,  upon  a  mill  plate  of  very  soft  steel. 

Oriental  rubies,  sapphires,  and  topazes,  are  cut  with  diamond  powder  soaked  with  olive 
oil,  on  a  copper  wheel.  The  facets  thus  formed  are  afterwards  polished  on  another  cop- 
per wheel,  with  tripoli,  tempered  with  water. 

Emeralds,  hyacinths,  amethysts,  garnets,  agates,  and  other  softer  stones,  are  cut  at  a 
Jead  wheel,  with  emery  and  water;  and  are  polished  on  a  tin  wheel  with  tripoli  and 
water,  or,  still  better,  on  a  zinc  wheel,  with  putty  of  tin  and  water.  v    i    p  v  ^ 

The  more  tender  precious  stones,  and  even  the  pastes,  are  cut  on  a  mill-wheel  of  hard 
wood,  with  emery  and  water;  and  are  polished  with  tripoli  and  Water,  on  another  wheel 

of  hard  wood.  ,  v  v  i.        ♦ 

Since  the  lapidary  employs  always  the  same  tools,  whatever  be  the  stone  which  he  cuts 
or  polishes,  and  since  the  wheel  discs  alone  vary,  as  also  the  substance  he  uses  with  them, 
we  shall  describe,  first  of  all,  his  apparatus,  and  then  the  manipulations  for  diamond-cut- 
ting, which  are  applicable  to  every  species  of  stone. 
The  lapidary's  mill,  or  wheel,  is  shown  in  perspective  in  fig.  841.    It  consists  of 

a  strong  frame  made  of  oak  carpentry,  with 
tenon  and  mortised  joints,  bound  together 
with  strong  bolts  and  screw  nuts.  Its  form 
is  a  parallelepiped  of  from  8  to  9  feet  long,  by 
from  6  to  7  high ;  and  about  2  feet  broad. 
These  dimensions  are  large  enough  to  con- 
lain  two  cutting  wheels  alongside  of  each 
other,  as  represented  in  the  figure. 

Besides  the  two  sole  bars  b  b,  we  perceive 


«%  D, 


E,  F, 


G. 


m  the  breadth,  5  cross  bars,  .  ,  .  . 
The  two  extreme  bars  c  and  g,  are  a  part  of 
Ihr  frame-work,  and  serve  to  bind  it.  The 
two  cross-bars  d  and  f,  carry  each  in  the 
middle  of  their  length,  a  piece  of  wood  as 
thick  as  themselves,  but  only  A\  inches  long 
(see  fig,  842),  joined  solidly  bv  mortises  and  tenons  with  that  cross  bar,  as  well  a£ 

/ 


tfK» 


\ 


24 


LAPIDARY. 


with  the  one  placed  opposite  on  the  other  parallel  face.      These  two  pieces  are  called 

summers  (lintels)  ;  the  one  placed  at  d  is  the  upper ;  the  one  at  f,  the  lower. 

In  Jig.  842  this  face  is  shown  inside,  in  order  to  explain  how  the  mill  wheel  is  placed 

and  supported.      The  same  letters  point  out  the  same  objects,  both  in  the  preceding  and 

the  followins;  figures. 

In  each  of  these  summers  a  square  hole  is  cut  out,  exactly  opposite  to  the  other;  in 

which  are  adjusted  by  friction,  a  square  piece  of  oak  a,  a,  Jig, 
842.  whose  extremities  are  perforated  with  a  conical  hole, 
which  receives  the  two  ends  of  the  arbor  h  of  the  wheel  i, 
and  forms  its  socket.  The  square  bar  is  adjusted  at  a  conve- 
nient height,  by  a  double  wooden  wedge  b  b. 

The  cross  bar  in  the  middle  e  supports  the  table «:  c,  a 
strong  plank  of  oak.  It  is  pierced  with  two  large  holes  whose 
centres  coincide  with  the  centre  of  the  conical  holes  hollov/- 
ed  out  at  the  end  of  the  square  pins.  These  holes,  of  about 
6  inches  diameter  each,  are  intended  to  let  the  arbor  pass 
freely  through,  bearing  its  respective  wheel.      (See  one  of 


these  holes  at  i,  in  Jig.  846  below.) 

Each  wheel  is  composed  of  an  iron  arbor  h,  Jig.  843. 
ffrinding-wheel  i,  which  diilers  in  substance 


according 


of  a 
to 


848 


circumstances,  as  already  stated,  and  of  the  pulley  J,  furnish- 
ed with  several  grooves  (see  Jig.  844),  which  has  a  square 
fit  upon  the  arbor.  The  arbor  carries  a  collet  d,  on  which 
are  4  iron  pegs  or  pins  that  enter  into  the  wheel  to  fasten 
it. 

The  wheel  plate,  of  which  the  ground  plan  is  shown  at  k, 
is  hollowed  out  towards  its  centre  to  half  its  thickness ;  when 
844  it  is  in  its  position  on  the  arbor,  as  indicated  in  Jig.  844.  a 

washer  or  ferrule  of  wrought  iron  is  put  over  it,  and  secured 
in  its  place  by  a  double  wedge.  In  Jig.  844  the  wheel-plate 
is  represented  in  section,  that  the  connexion  of  the  whole 
parts  may  be  seen. 

A  board  g  (see  fig.  841  and^g.  849),  about  7|  inches  high, 
is  fixed  to  the  part  of  the  frame  opposite  to  the  side  at  which 
the  lapidary  works,  and  it  prevents  the  substances  made  use 
of  in  the  cutting  and  polishing,  from  being  thrown  to  a  dis- 
tance by  the  centrifugal  force  of  the  wheel-plate. 

Behind  this  apparatus  is  mounted  for  each  grinding-plate, 
a  large  wheel  l  (see  fig.  841),  similar  to  a  cutlei-'s,  but  placed 
horizontally.  This  wheel  is  grooved  round  its  circumfer- 
ence to  receive  an  endless  cord  or  band,  which  passes  round  one  of  the  grooves  of  the 
pulley  J,  fixed  below  the  wheel-plate.  Hence,  on  turning  the  fly-wheel  l,  the  plate  re- 
volves with  a  velocity  relative  to  the  velocity  communicated  to  the  wheel  l,  and  to  the  dif- 
ference of  diameter  of  the  wheel  l  and  the  pulley  J.  Each  wheel  l,  is  mounted  on  an 
iron  arbor,  with  a  crank  (see  m.  Jig.  846.) 

The  lower  pivot  of  that  arbor  h  is  conical,  and  turns  in  a  socket  fixed  in  the  floor.  The 
great  wheel  l  rests  on  the  collet  i,  furnished  with  its  4  iron  pins,  for  securing  the  con- 
nexion. Above  the  wheel  an  iron  washer  is  laid,  and  the  whole  is  fixed  by  a  double  wedge, 
which  enters  into  the  mortise  I,  Jig.  845. 

Fig.  846.  exhibits  a  ground-plan  view  of  all 
this  assemblage  of  parts,  to  explain  the  structure 
of  the  machine.  Every  thing  that  stands  above 
the  upper  summer-bar  has  been  suppressed  in  this 
representation.  Here  we  see  the  table  c  c  ;  the 
upper  summer  m ;  the  one  wheel-plate  /,  the  other 
having  been  removed  to  show  that  the  endless  cord 
does  not  cross  ;  the  two  large  wheels  l  l,  present 
in  each  machine,  the  crank  bar  n,  seen  separate 
in  Jig.  847.  which  serves  for  turning  the  wheel  l. 


1^1 


847 


f^^?=:^      nP—Iug^ 


N 


tos 


\ 


■V 


LAPIDARY. 


25 


bent  round  at  the  point  n,  to  embrace  the  stud  s ;  the  second,  p  g,  is  of  the  same  breadth 
and  thickness  as  the  first;  and  the  third  is  adjusted  to  the  latter  with  a  hinge  joint,  at 
the  point  9,  where  they  are  both  turned  into  a  circular  form,  to  fn^^'-f^th^  crank  m. 
When  all  these  pieces  are  connected,  they  are  fixed  at  the  proper  lengths  by  the  buckles 
or  SGuare  rings  i  1 1,  which  embrace  these  pieces  as  is  shown  m  fig.  846. 

T\e  stud  I  seen  in  Jig.  847.  is  fixed  to  the  point  v  by  a  wedge  key  upon  the  arm  f, 
represented  separately,  and  In  perspective  injig.  848.  The  laborer  ^eizmg  the  two  up- 
right  pegs  or  handles  x  x,  by  the  alternate  forward  and  backward  motion  of  h^s  arm  he 
communicates  the  same  motion  to  the  crank  rod,  which  transmits  it  to  the  crank  of  the 
arbor  m,  and  impresses  on  that  arbor,  and  the  wheel  which  it  bears,  a  rotatorj'  move- 
ment. 

849 


This  bar  is  formed  of  3  iron  plates,  n,  o;  V»q ;  and  ^,  r ;  (/ig.   847.)    T^he  firsi  i» 


Fig.  849.  shows  piece-meal  and  in  perspective,  a  part  of  the  lapidary  s  wheel-min. 
There  we  see  the  table  c  c,  the  grind-plate  i,  whose  axis  is  kept  in  a  vertical  Position  b, 
the  two  square  plugs  a  a,  fixed  into  the  two  summers  by  the  wedges  bb.  On  the  two 
sWefof  the  wheVplate  we  perceive  an  important  instrument  called  a  dtaZ,  which  serve, 
to  hold  lie  stone  durin"  the  cutting  and  polishing.  This  instrument  has  received  lately 
mpo  tin   aSeto^^^^^  described  in  fig.  850.    The  lapidary  holds  this  instrument 

n  his  hand,  he  rests  it  upon  the  iron  pins  u  u  fixed  in  ^le  table,  lest  he  should  be  affected 
by  the  velocity  of  the  revolving  wheel-plate.  He  loads  it  sometimes  with  weights  e,  e, 
to  make  it  take  better  hold  of  the  grinding  plate.  ^  ^    /.  „      •      •  ^ 

One  of  the  most  expert  lapidaries  of  Geneva  works  by  means  of  the  following  improved 
me^hanbm,  of  his  own  invention,  wl.ereby  he  cuts  and  pohshes  the  facets  with  extreme 

iptTiilaritv.  converting  it  into  a  true  dial.  ^    ,     -  ,  •         » 

le^uiariiy,  c  n  e       S         ^^^  ^^^^^  ^j^.^  j^nprovement.     Each  of  the  two  jaws  bears  a 

large  conchoidal  cavity,  into  which  is  fitted  a  brass  ball,  which  carries 
on  its  upper  part  a  tube  e,  to  whose  extremity  is  fixed  a  dial-plate//, 
en^'raved  with  several  concentric  circles,  divided  into  equal  parts,  like 
the  toothed-wheel  cutting  engine-plate,  according  to  the  number  of 
facets  to  be  placed  in  each  cutting  range.      The  tube  receives  with 
moderate  friction  the  handle  of  the  cement  rod,  which  is  fixed  at  the 
proper  point  by  a  thumb-screw,  not  shown  in  the  figure,  being  con- 
cealed by  the  vertical  limb  d,  about  to  be  described. 
A  needle  or  index  g,  placed  with  a  square  fit  on  the  tail  of  the  cement  rod,  marks  by 
its  point  the  divisions^on  the  dial  plate  //.     On  the  side  m  n  of  the  jaw  a,  there  isSxed 
by  two  "screws,  a  limb  d,  forming  a  quadrant  whose  centre  is  supposed  to  be  at  the  centre 
of   he  ball.     This  quadrant  is  divided  as  usual  into  90  degrees,  whose  highest  point  is 
marked  0,  and  the  lowest  would  mark  about  70  ;  for  the  remainder  of  the  arc  do^vn  to 
90  is  concealed  by  the  jaw.    The  two  graduated  plates  are  used  as  follows  :- 

When  the  cement  rod  conceals  zero  or  0  of  the  limb,  it  is  then  ^'e^ical  and  serves  to 
cut  the  table  of  the  brilliant ;  or  the  point  opposite  to  it,  and  parallel  to  the  table.  On 
making  it  slope  a  little,  5  degrees  for  example,  all  the  facets  will  now  lie  m  the  same 
zone,  provided  that  the  inclination  be  not  allowed  to  var5^  On  turning  round  the 
cement  rod  the  index  g  marks  the  divisions,  so  that  by  operating  on  the  circle  with  16 
divisions,  stopping  for  some  time  at  each,  16  facets  will  have  been  formed,  of  perfect 
eaualitv,  and  at  equal  distances,  as  soon  as  the  revolution  is  completed. 

Diamonds  are  cut  at  the  present  day  in  only  two  modes;  into  a  rose  diamond,  and  a 
brilliant.     AVe  shall  therefore  confine  our  attention  to  these  two  forms. 

The  rose  diamond  is  flat  beneath,  like  all  weak  stones,  whUe  the  upper  face  nse*  jilo 
a  dome,  and  is  cut  into  facets.      Most  usually  six  facets  are  put  on  the  cenual  region, 


te  LAPIDARY. 

which  are  in  the  form  of  triangles,  and  unite  at  their  summiti ;  their  bases  abut  upon 
another  range  of  triangles,  which  being  set  in  an  inverse  position  to  the  preceding,  present 
theii-  bases  to  them,  while  their  summits  terminate  at  the  sharp  margin  of  the  stone.  The 
latter  triangles  leave  spaces  between  them  which  are  likewise  cut  each  into  two  facets. 
By  this  distribution  the  rose  diamond  is  cut  into  24  facets;  the  surface  cf  the  diamond 
being  divided  into  two  portions,  of  which  the  upper  is  called  the  crown,  and  that  forming 
the  contour,  beneath  the  former,  is  called  dcnlette  (lace)  by  the  French  artists. 

According  to  Mr.  Jeffries,  in  his  Treatise  on  Diamonds,  the  regular  rose  diamond  is 
formed  by  inscribing  a  regular  octagon  in  the  centre  of  the  table  side  of  the  stone,  and 
bordering  it  by  eight  right-angled  tiiangles,  the  bases  of  which  correspond  with  the  sides 
of  the  octagon;  beyond  these  is  a  chain  of  8  trapeziums,  and  another  of  16  triangles. 
The  collet  side  also  consists  of  a  minute  centra]  octagon,  from  every  angle  of  which  pro- 


ceeds a  ray  to  the  edge  of  the 


jirdle,  forming 


the  whole  surface  into  8  trapeziums,  each 


of  which  is  again  subdivided  by  a  salient  angle  (whose  apex  touches  the  girdle)  into  one 
irregular  pentagon  and  two  triangles. 

To  fashion  a  rough  diamond  into  a  brilliant,  the  first  step  is  to  modify  the  faces  of  the 
original  octahedron,  so  that  the  plane  formed  by  the  junction  of  the  two  pyramids  shall 
be  an  exact  square,  and  the  axis  of  the  crystal  precisely  twice  the  length  of  one  of  the 
sidts  of  the  square.  The  octahedron  being  thus  rectified,  a  section  is  to  be  made  parallel 
to  >,he  common  base  or  girdle,  so  as  to  cut  oft'  5  eighteenths  of  the  whole  height  from  the 
upper  pyramid,  and  1  eighteenth  from  the  lower  one.  The  superior  and  larger  plane 
thus  produced  is  called  the  table,  and  the  inferior  and  smaller  one  is  called  the  collet ;  in 
this  state  it  is  termed  a  complete  square  table  diamond.  To  convert  it  into  a  brilliaut, 
two  triangular  facets  are  placed  on  each  side  of  the  table,  thus  changing  it  from  a  square 
to  an  octagon ;  a  lozenge-shaped  facet  is  also  placed  at  each  of  the  four  corners  of  the 
table,  and  another  lozenge  extending  lengthwise  along  the  whole  of  each  side  of  the  ori- 
ginal square  of  the  table,  which  with  two  triangular  facets  set  on  the  base  of  each 
lozenge,  completes  the  whole  number  of  facets  on  the  table  side  of  the  diamond ;  viz.,  8 
lozenges,  and  24  triangles.  On  the  collet  side  are  formed  4  irregular  pentagons,  alter- 
nating with  as  many  irregular  lozenges  radiating  from  the  collet  as  a  centre,  and  bordered 
by  16  triangular  facets  adjoining  the  girdle.  The  brilliant  being  thus  completed,  is  set 
with  the  table  side  uppermost,  and  the  collet  side  implanted  in  the  cavity  made  to  receive 
the  diamond.  The  brilliant  is  always  three  times  as  thick  as  the  rose  diamond.  In 
France,  the  thickness  of  the  brilliant  is  set  oflT  into  two  unequal  portions ;  one  third  is 
reserved  for  the  upper  part  or  table  of  the  diamond,  and  the  remaining  two  thirds  for  the 
lower  part  or  collet  {culasse).  The  table  has  eight  planes,  and  its  circumference  is  cut 
into  facets,  of  which  some  are  triangles,  and  others  lozenges.  The  collet  is  also  cut  into 
facets  called  pavilions.  It  is  of  consequence  that  the  pavilions  lie  in  the  same  order  as 
the  upper  facets,  and  that  they  correspond  to  each  other,  so  that  the  symmetry  be  perfect, 
for  otherwise  the  play  of  the  light  would  be  false. 

Although  the  rose-diamond  projects  bright  beams  of  light  in  more  extensive  proportion 
often  than  the  brilliant,  yet  the  latter  shows  an  incomparably  greater  play,  from  the  difler- 
ence  of  its  cutting.  In  executing  this,  there  are  formed  32  faces  of  diflerent  figures,  and 
inclined  at  diflerent  angles  all  round  the  table,  on  the  upper  side  of  the  stone.  On  the 
collet  (culasse)  24  other  faces  are  made  round  a  small  table,  which  converts  the  culasse 
into  a  truncated  pyramid.  These  24  facets,  like  the  32  above,  are  diflerently  inclined  and 
present  diflerent  figures.  It  is  essential  that  the  faces  of  the  top  and  the  bottom  corres- 
pond together  in  sufficiently  exact  proportions  to  multiply  the  reflections  and  refractions, 
so  as  to  produce  the  colors  of  the  prismatic  spectrum. 

The  other  precious  stones,  as  well  as  their  artificial  imitations,  called  pastes,  are  cut  in 
the  same  fashion  as  the  brilliant ;  the  only  diflerence  consists  in  the  matter  constitulii.g 


851 


852 


the  wheel  plates,  and  the  grinding  and  polishing  powders 
as  already  stated. 

In  cutting  the  stones,  they  are  mounted  on  the  cement- 
rod  B,fis^.  851,  whose  stem  is  set  upright  in  a  socket  placed 
PI    [IN  .  "  ,_  ~~1     ill  the  middle  of  a  sole  piece  at  a,  which  receives  the  stem 

I       nT^^^^^^Pj  of  the  cement-rod.     The  head  of  the  rod  fills  the  cup  of  A. 

y    ^\  ~\  T  \  -^  melted  alloy  of  tin  and  lead  is  poured  into  the  head  of  the 

cement-rod,  into  the  middle  of  which  the  stone  is  immediately 
plunged ;  and  whenever  the  solder  has  become  solid,  a  por- 
tion of  it  is  pared  off"  from  the  top  of  the  diamond,  to  give 
the  pyramidal  form  shown  in  the  figure  at  b. 
There  is  an  instrument  employed  by  the  steel  polishers  for  pieces  of  clock  work,  and 
by  the  manufacturers  of  watch-glasses  for   polishing  their   edges.      It  consists  of  a 
solid  oaken   table.  Jig.  852.     The  top  is  perforated  with   two  holes,  one  for   passing 
through  the  pulley  and  the  arbor  of  the  wheel-plate  b,  made  either  of  lead  or  of  hard 


LAPIDARY. 


27 


wood  according  to  circumstances ;  and  the  other  c  fcj  receiving  the  upper  pari  of  the 
arbor  of  the  large  pulley  d.  The  upper  pulley  of  the  wheel  plate  is  supported  by  an  iron 
prop  E,  fixed  to  the  table  by  two  wooden  screws.  The  inferior  pivots  of  the  two  pieces 
are  supported  by  screw-dockets,  working  in  an  iron  screw-nut  sunk  into  the  summer-bar 
F  The  le"^s  of  the  table  are  made  longer  or  shorter,  according  as  the  workman  chooses 
to  stand  or''sit  at  his  employment.  Emery  with  oil  is  used  for  grinding  down,  and  tin- 
putty  or  colcothar  for  polishing.  The  ^»orkman  lays  the  piece  on  the  flat  of  the  wheel- 
plate  with  one  hand,  and  presses  it  down  with  a  lump  of  cork,  whUe  he  turns  round  the 

handle  with  the  other  hand.  ,   ^  .    ^  ,  ,tt  _^ 

The  Sapphire,  Ruby,  OneiUal  Amethyst,  Oriental  Emerald,  and  Oriental  Topaz,  are 
gems  next  in  value  and  hardness  to  diamond ;  and  they  all  consist  of  nearly  pure  alumina 
or  clay  with  a  minute  portion  of  iron  as  the  coloring  matter.  The  foUowing  analyses 
show  the  affinity  in  composiUon  of  the  most  precious  bodies  with  others  in  little  relative 
estimation. 


Sapphire. 

Corundum  Stone. 

Emery. 

Alumina  or  clay 
Silica     - 
Oxyde  of  iron    - 
Lime      -            -            - 

98-5 
0-0 
1-0 
0-5 

89-50 
5-50 
1-25 
0-00 

86-0 
30 
4*0 
0-0 

100-0 

96-25 

93-0 

i 


Salamstme  is  a  variety  which  consists  of  small  transparent  crystals,  generally  six-sided 
prisms,  of  pale  reddish  and  bluish  colors.  The  corundum  of  Batlagammana  is  fre^iuently 
found  in  large  six-sided  prisms :  it  is  commonly  of  a  brown  color,  whence  it  is  called  by 
the  natives  curuwiu  gallc,  cinnamon  stone.  'I'he  hair-brown  and  reddish-brown  crystals 
are  called  adamantine  spar.  Sapphire  and  salamstone  are  chiefly  met  with  in  secondary 
repositories,  as  in  the  sand  of  rivers,  &c.,  accompanied  by  crystals  and  grains  of  octahe- 
dral iron-ore  and  of  several  species  of  gems.  Corundum  is  found  in  imbedded  crystals  m 
a  rock,  consisting  of  indianite.     Adamantine  spar  occurs  in  a  sort  of  granite. 

The  finest  varieties  of  sapphire  come  from  Pegu,  where  they  occur  in  the  Capelan 
mountains  near  Syrian.  Some  have  been  found  also  at  Hohenstein  in  Saxony,  Bilin  in 
Bohemia,  Puy  in  France,  and  in  several  other  countries.  The  red  variety,  the  ruby,  is 
most  highly  valued.  Its  color  is  between  a  bright  scarlet  and  crunson.  A  perfect  ruby 
above  3h  carats  is  more  valuable  than  a  diamond  of  the  same  weight.  If  it  weigh  1 
carat,  it  is  worth  10  guineas;  2  carats,  40  guineas;  3  carats,  150  guineas;  6  carats, 
above  1000  guineas.  A  deep  colored  ruby,  exceeding  20  carats  in  weight,  is  generally 
called  a  carbuncle ;  of  which  108  were  said  to  be  in  the  throne  of  the  Great  Mogul, 
wei'^hin*'  from  100  to  200  carats  each ;  but  this  statement  is  firobably  incorrect.  The 
lar4st  oriental  ruby  known  to  be  in  the  world  was  brought  from  China  to  Prmce  Gar- 
gann,  governor  of  Siberia.  It  came  afterwards  into  the  possession  of  Prmce  MenzUtotf, 
and  constitutes  now  a  jewel  in  the  imperial  crown  of  Russia.  .  ^    «^        ,     .. 

A  ^ood  blue  sapphire  of  10  carats  is  valued  at  50  guineas.  If  it  weighs  20  carats,  its 
value" is  200  'guineas ;  but  under  10  carats,  the  price  may  be  estimated  by  multiplying  the 
square  of  its  weight  in  carats  into  half  a  guinea ;  thus,  one  of  4  carats  would  be  worth 
42  X  ^  G  =8  guineas.  It  has  been  said  that  the  blue  sapphire  is  superior  m  hardness 
tothe^'red,  but  this  is  probably  a  mistake  arising  from  confounding  the  corundum  ruby 
with  the  <;pinelle  ruby.  A  sapphire  of  a  barbel  blue  color,  weighing  6  carats,  was  dis- 
posed of  in  Paris  by  public  sale  for  70^.  sterling ;  and  another  of  an  indigo  blue,  weighing 
6  carats  and  3  grains,  brought  60/. ;  both  of  which  sums  much  exceed  what  the  preceding 
rule  assigns,  from  which  we  may  perceive  how  far  fancy  may  go  in  such  matters.  The 
sapphire  of  Brazil  is  merely  a  blue  tourmaline,  as  its  specific  gravity  and  inferior  hard- 
ness show.  White  sapphires  are  sometimes  so  pure,  that  when  properly  cut  and  polished 
they  have  been  passed  for  diamonds.  /.  /^  • 

The  vellow  and  green  sapphires  are  much  prized  under  the  names  of  Oriental  topax 
and  emerald.  The  specimens  which  exhibit  all  these  colors  associated  in  one  stone  ore 
hiffhlv  valued,  as  they  prove  the  mineralogical  identity  of  these  varieties. 

Besides  these  shades  of  color,  sapphires  often  emit  a  beautiful  play  of  colors,  or 
chatoiement,  when  held  in  diff'erent  positions  relative  to  the  eye  or  incident  light ;  and 
some  likewise  present  star-like  radiations,  whence  they  are  called  star-stones  or  astenas ; 
sending  forth  6  or  even  12  rays,  that  chari^e  their  place  with  the  position  of  the  stone. 
This  property,  so  remarkable  in  certain  blue  sapphires,  is  not,  however,  peculiar  to  these 
gems.      It  seems  to  belong  to  transparent  minerals  which  have  a  rhomboid  for  their 

/ 


28 


LAPIDARY. 


LEAD. 


29 


nucleus,  and  arises  from  the  combination  of  certain  circumstances  in  their  cutting  and 
structure.  Lapidaries  often  expose  the  light-blue  variety  of  sapphire  to  the  action  of 
fire,  in  order  to  render  it  white  and  more  brilliant ;  but  with  regard  to  those  found  at 
Expailly,  in  France,  fire  deepens  their  color. 

3.  Chrysoberyly  called  by  Hauy,  Cymophane,  and  by  others.  Prismatic  corundum,  ranks 
next  in  hardness  to  sapphire,  being  8-5  on  the  same  scale  of  estimation.  Its  specific  grav- 
ity is  3*754.  It  usually  occurs  in  rounded  pieces  about  the  size  of  a  pea,  but  it  is  also 
found  crystallized  in  many  forms,  of  which  8-sided  prisms  with  8-sided  summits  are  per- 
haps the  most  frequent.  Lustre  vitreous,  color  asparagus  green,  passing  into  greenish- 
white  and  olive-green.  It  shows  a  bluish  opalescence,  a  light  undulating,  as  it  were,  in 
the  stone,  when  viewed  in  certain  directions ;  which  property  constitutes  its  chief  at- 
traction to  the  jeweller.  When  polished,  it  has  been  sometimes  mistaken  for  a  yellow 
diamond ;  and  from  its  hardness  and  lustre  is  considerably  valued.  Good  specimens 
of  it  are  very  rare.  It  has  been  found  only  in  the  alluvial  deposites  of  rivers,  along  with 
other  species  of  gems.  Thus  it  occurs  in  Brazil,  along  with  diamonds  and  prismatic  to- 
paz ;  also  in  Ceylon.  Its  constituents  are  alumina,  68-66 ;  glucina,  16-00  ;  silica,  6-00 ; 
protoxyde  of  iron,  4-7  ;  oxyde  of  titanium,  2-66 ;  moisture,  0-66 ;  according  to  Seybert's 
analysis  of  a  specimen  from  Brazil.  It  is  difficultly  but  perfectly  fusible  before  the  blow- 
pipe, with  borax  and  salt  of  phosphorus.  In  composition  it  dilfers  entirely  from  sapphire, 
or  the  rhombohedral  corundum. 

4.  Spinelle  Ruby,  called  Dodecahedral  corundum,  by  some  mineralogists,  and  Balas 
ruby,  by  lapidaries.  Its  hardness  is  8.  Specific  gravity,  3-523.  Its  fundamental  form  is 
the  hexahedron,  but  it  occurs  crystallized  in  many  secondary-  forms :  octahedrons,  tetra- 
hedrons, and  rhombohedrons.  Fracture,  conchoidal ;  lustre,  vitreous ;  color,  red,  passing 
into  blue  and  green,  yellow,  brown,  and  black ;  and  sometimes  it  is  nearly  white.  Red 
spinelle  consists  of  alumina,  74-5  ;  silica,  15-5;  magnesia,  8-25;  oxyde  of  iron,  1.5;  lime, 
0-75.  Vauquelin  discovered  6-18  per  cent,  of  chromic  acid  in  the  red  spinelle.  The 
red  varieties  exposed  to  heat  become  black  and  opaque ;  on  cooling,  they  appear  first 
green,  then  almost  colorless,  but  at  last  resume  their  red  color.  Pleonaste  is  a  variety 
which  yields  a  deep  green  globule  with  borax. 

Crystals  of  spinelle  from  Ceylon  have  been  observed  imbedded  in  limestone,  mixed 
with  mica,  or  in  rocks  containing  adularia,  which  seem  to  have  belonged  to  a  primitive 
district.  Other  varieties  like  the  pleonaste  occur  in  the  drusy  cavities  of  rocks  ejected 
by  Vesuvius.  Crystals  of  it  are  often  found  in  diluvial  and  alluvial  sand  and  gravel, 
along  with  true  sapphires,  pyramidal  zircon,  and  other  gems  ;  as  also  with  octahedral  iron 
ore,  in  Ceylon.  Blue  and  pearl-gray  varieties  occur  in  Siidennannland,  in  Sweden,  im- 
bedded in  granular  limestone.  Pleonaste  is  met  with  also  in  the  diluvial  sands  of  Cey- 
lon. Clear  and  finely  colored  specimens  of  spinelle  are  highly  prized  as  ornamental 
stones.  When  the  weight  of  a  good  spinelle  exceeds  4  carats,  it  is  said  to  be  valued  at 
half  the  price  of  a  diamond  of  the  same  weight.  M.  Brard  has  seen  one  at  Paris  which 
weighed  215  grains. 

5.  Zircon  or  Hyacinth.  Its  fundamental  form  is  an  isosceles  4-sided  pjTamid ;  and 
the  secondary  forms  have  all  a  pyramidal  character.  Fracture,  conchoidal,  uneven; 
lustre,  more  or  less  perfectly  adamantine  colors,  red,  brown,  yellow,  gray,  green,  white ; 
which,  with  the  exception  of  some  red  tints,  are  not  bright.  Hardness,  7-5.  Specific 
gravity,  4-5.  Zircon  and  hyacinth  consist,  according  to  Klaproth,  of  almost  exactly  the 
same  constituents ;  namely,  zirconia,  70  ;  silica,  25 ;  oxyde  of  iron,  5.  In  the  white 
zirconia  there  is  less  iron  and  more  silica.  Before  the  blowpipe  the  hyacinth  loses  its 
color,  but  does  not  melt.  The  brighter  zircons  are  often  worked  up  into  a  brilliant  form, 
for  ornamenting  watch  cases.  As  a  gem,  hyacinth  has  no  high  value.  It  has  been  often 
confounded  with  other  stones,  but  its  very  great  specific  gravity  makes  it  to  be  readily 
recognised, 

6.  Topaz.  The  fundamental  form  is  a  scalene  4-sided  p>Tamid ;  .but  the  secondary 
forms  have  a  prismatic  character ;  and  are  frequently  observed  in  oblique  4-sided  prisms, 
acuminated  by  4  planes.  The  lateral  planes  of  the  prism  are  longitudinally  striated. 
Fractuie,  conchoidal,  uneven  ;  lustre,  vitreous;  colors,  white,  yellow,  green,  blue;  gen- 
erally of  pale  shades.  Hardness,  8  ;  specific  gravity,  3-5.  Prismatic  topaz  consists,  ac- 
cording to  Berzelius,  if  alumina,  57*45;  silica,  34-24;  fluoric  acid,  7*75.  In  a  strong 
heat  the  faces  of  crystallization,  but  not  those  of  cleavage,  are  covered  with  small  blis- 
ters, which  however  immediately  crack.  With  borax,  it  melts  slowly  into  a  transparent 
glass.  Its  powder  colors  the  tincture  of  violets  green.  Those  crystals  which  possess 
different  faces  of  crystallization  on  opposite  ends,  acquire  the  opposite  electricities  on 
being  heated.     By  friction,  it  acquires  positive  electricity. 

Most  perfect  crystals  of  topaz  have  been  found  in  Siberia,  of  green,  blue,  and  white 
colors,  along  with  beryl,  in  the  Uralian  and  Altai  mountains,  as  also  in  Kamschatka ;  in 
Brazil,  where  they  generally  occur  in  loose  crjstals,  and  pebble  forms  of  bright  yel- 


t 


4 


low  colors ;  and  in  Mucla,  in  Asia  Minor,  in  pale  straw-yellow  regular  crystals.  They 
are  also  met  with  in  the  granitic  detritus  of  Cairngorm,  in  Aberdeenshire.  The  blue 
varieties  are  absurdly  called  oriental  aquamarine^  by  lapidaries.  If  exposed  to  heat,  the 
Saxon  topaz  loses  its  color  and  becomes  white ;  the  deep  yellow  Brazilian  varieties  as- 
sume a  pale  pink  hue  ;  and  are  then  sometimes  mistaken  for  spinelle,  to  which,  however, 
they  are  somewhat  inferior  in  hardness.  Topaz  is  also  distinguishable  by  its  double 
refractive  properly.  Tavemier  mentions  a  topaz,  in  the  possession  of  the  Great  Mogul, 
which  weighed  157  carats,  and  cost  20,000Z.  sterling.  There  is  a  specimen  in  the  museum 
of  naturalhistory  at  Paris  which  weighs  4  ounces  2  gros. 
Topazes  are  not  scarce  enough  to  be  much  valued  by  the  lapidary. 

7.  Emerald  and  Beryl  are  described  in  their  alphabetical  places.  Emerald  loses  \ts 
lustre  by  candle-light ;  but  as  it  appears  to  most  advantage  when  in  the  company  of  dia- 
monds, it  is  frequently  surrounded  with  brilliants,  and  occasionally  with  pearls.  Beryl  is 
the  aquamarine  of  the  jewellers,  and  has  very  little  estimation  among  lapidaries. 

8.  Garnet.     See  this  stone  in  its  alphabetical  place. 

9.  Chrysolite,  called  Peridot,  by  Haiiy ;  probably  the  topaz  of  the  ancients,  as  our  topax 
was  their  clir>'solite.  It  is  the  softest  of  the  precious  stones,  being  scratched  by  quarts 
and  the  file.    It  refracts  double. 

10.  QttcWr,  including,  as  s\ih-s^ecies,  Jlmeihyst,  Rock-crystal ,  Rose-guani,  Prase,  or 
Chrysoprase,  and  several  varieties  of  calcedony,  as  Cat's-eye,  Plasma,  Chrysoprase,  Onyx, 
Sardmiyx,  &c.  Lustre,  vitreous,  inclining  sometimes  to  resinous;  colors,  very  various; 
fracture,  conchoidal ;  hardness,  7 ;  specific  gravity,  2-69. 

11.  Opal,  or  uncleavable  quartz.  Fracture,  conchoidal;  lustre,  vitreous  or  resinous i 
colors,  white,  yellow,  red,  brown,  green,  gray.  Lively  play  of  light ;  hardness,  5-5  to 
6-5;  specific  gravity,  2-091.  It  occurs  in  small  kidnej-shaped  and  stalactitic  shapes, 
and  large  tuberose  concretions.  The  phenomena  of  the  play  of  colors  in  precious 
opal  has  not  been  satisfactorily  explained.  It  seems  to  be  connected  with  the  regular 
Structure  of  the  mineral.  Hydrophane,  or  oculis  mundi,  is  a  variety  of  opal  without 
transparency,  but  acquiring  it  when  immersed  in  water,  or  in  any  transparent  fluid. 
Precious  opal  was  found  by  Klaproth  to  consist  of  silica,  90 ;  water,  10 ;  which  is  a 
very  curious  combination.  Hungary  has  been  long  the  only  locality  of  precious  opal, 
where  it  occurs  near  Caschau,  along  with  common  and  semi-opal,  in  a  kind  of  porphyry. 
Fine  varieties  have,  however,  been  lately  discovered  in  the  Faroe  islands ;  and  most  beau- 
tiful ones,  sometimes  quite  transparent,  near  Gracias  a  Dios,  in  the  province  of  Hondu- 
ras, America.  The  red  and  yellow  bright  colored  varieties  of  fire-opal  are  found  near 
Zimapan,  in  Mexico.  Precious  opal,  when  fashioned  for  a  gem,  is  generally  cut  with  a 
convex  surface ;  and  if  large,  pure,  and  exhibiting  a  bright  play  of  colors,  is  of  consid- 
erable value.  In  modern  times,  fine  opals  of  moderate  bulk  have  been  frequently  sold 
at  the  price  of  diamonds  of  equal  size  :  the  Turks  being  particularly  fond  of  them.  The 
estimation  in  which  opal  was  held  by  the  ancients  is  hardly  credible.  They  called  it 
Paideros,  or  Child  beautiful  as  love.  Nonius,  the  Roman  senator,  prefeired  banishment 
to  parting  with  his  favorite  opal,  which  was  coveted  by  Mark  Antony.  Opal  which  ap- 
pears quite  red  when  held  against  the  light,  is  called  girasol  by  the  French ;  a  name  also 
given  to  the  sapphire  or  corundum  asterias  or  star-stone. 

12.  Turquois  or  Calaite.  Mineral  turqucis  occurs  massive ;  fine-grained,  impalpable ; 
fracture,  conchoidal ;  color,  between  a  blue  and  a  green,  soft,  and  rather  bright ;  opaque ; 
hardness,  6  ;  spec,  grav.,  283  to  3-0.  Its  constituents  are  alumina,  73  ;  oxyde  of  copper, 
4-5;  oxyde  of  iron,  4;  water,  18;  according  to  Dr.  John.  But  by  Berzelius,  it  consists 
of  phosphate  of  alumina  and  lime,  silica,  oxydes  of  copper,  and  iron,  with  a  little  water. 
It  has  been  found  only  in  the  neighborhood  of  Nichabour  in  the  Khorassan,  in  Persia ; 
and  is  very  highly  prized  as  an  ornamental  stone  in  that  country.  There  is  a  totally  dif- 
ferent kind  of  turquois,  caUed  bone  turquois,  which  seems  to  be  phosphate  of  lime  colored 
with  oxyde  of  copper.  When  the  oriental  stone  is  cut  and  polished,  it  forms  a  pleasing 
gem  of  inferior  value.  Malachite,  or  mountain  green,  a  compact  carbonate  of  copper, 
has  been  substituted  sometimes  for  turquois,  but  their  shades  are  different.  Malachite 
yields  a  green  streak,  and  turquois  a  white  one. 

13.  Lapis  lazuli  is  of  little  value,  on  account  of  its  softness. 

LAZULITE  (Eng.  and  Fr. ;  Lazulith^  Germ.);  is  a  blue  vitreous  mineral,  crystalliz- 
ing in  rhoraboidal  dodecahedrons;  spec.  grav.  2-76  to  2-94;  scratches  j^lass;  affords 
a  little  water  by  calcination;  fusible  into  a  white  glass;  dissolves  in  acids  with  loss 
of  color;  solution  leaves  an  alkaliue  residuum,  after  being  treated  with  carbonate  of 
ammonia,  filtered,  evaporated,  and  calcined.  It  consist?  of  silica,  35"8  ;  alumina,  84  8 ; 
soda,  23-2;  sulphur,  S'l  ;  carbonate  of  lime,  3'1.  This  beautiful  stone  affords  the 
native  ultramarine  pigment,  which  was  very  costly  till  a  mode  of  makiug  it  artificially 
was  lately  discovered.     See  Ultramarine. 

LEAD.     {Plomb,  Fr. ;  Blei,  Germ.)  This  is  one  of  the  metals  most  anciently  known 

/ 


30 


LEAD. 


Si 


being  mentioned  in  the  books  of  Moses.  It  has  a  gray  blue  color,  with  a  bright  metal- 
lie  lustre  wlien  newly  cut,  but  it  becomes  soon  tarnished  and  earthy  looking  in  the 
air.  Its  texture  is  close,  wiUiQut  perceptible  cleavage  or  appearance  of  structure  ;  the 
specific  gravity  of  common  lead  is  11-352;  but  of  the  pure  metal,  from  11-38  to 
11-44.  It  is  very  malleable  and  ductile,  but  soft  and  destitute  of  elasticity;  fusible 
Ht  61-2°  Fahr.  by  Crighton,  at  634°  by  Kupfer,  and  crystallizable  on  cooling,  into 
octahedrons  implanted  into  each  other  so  as  to  form  an  assemblage  of  four-sided 
pyramids. 

There  are  four  oxydes  of  lead.  1.  The  suboxyde,  of  a  grayish-blue  color,  which 
forms  a  kind  of  crust  upon  a  plate  of  lead  long  exposed  to  the  air.  It  is  procured  in  a 
perfect  state  by  calcining  oxalate  of  lead  in  a  retort ;  the  dark  gray  powder  which  re- 
mains, is  the  pure  suboxyde.  2.  The  protoxyde  is  obtained  by  exposing  melted  lead  to 
the  atmosphere,  or,  more  readily,  by  expelling  the  acid  from  the  nitrate  of  lead  by  heat  in 
a  platinum  crucible.  It  is  yellow,  and  was  at  one  time  prepared  as  a  pigment  by  cal- 
cining lead  ;  but  is  now  supereeded  by  the  chromate  of  this  metal.  Litharge  is  merely 
this  oxyde  in  the  form  of  small  spangles,  from  having  undergone  fusion ;  it  is  more  or 
less  contaminated  with  iron,  copper,  and  »ometimes  a  little  silver.  It  contains  likewise 
some  carbonic  acid.  The  above  oxyde  consists  of  104  of  metal,  and  8  of  oxygen,  its 
prime  eriuivalent  being  1 12,  upon  the  hydrogen  scale ;  and  it  is  the  base  of  all  the  salts 
of  lead.  3.  The  plumbeous  suroxyde  of  Berzelius,  the  sesquioxyde  of  some  British  chem- 
ists, is  the  well  known  pigment  called  red  lead  or  minium.  It  consists  of  100  parts  of 
metal  and  10  of  oxygen.  4.  The  plumbic  suroxyde  of  Berzelius,  or  the  peroxyde  of  the 
British  chemists,  is  obtained  by  putting  red  lead  in  chlorine  water,  or  in  dilute  nitric  acid. 
It  is  of  a  dark  brown,  almost  black  color,  which  gives  out  oxygen  when  heated,  and  be- 
comes yellow  oxyde.  It  kindles  sulphur  when  triturated  with  it.  This  oxyde  is  used  by 
the  analytical  chemist  to  separate,  by  condensation,  the  sulphurous  acid  existing  in  a 
gaseous  mixture. 

Among  the  ores  of  lead  some  have  a  metallic  aspect ;  are  black  in  substance,  as 
well  as  when  pulverized ;  others  have  a  stony  appearance,  and  are  variously  colored, 
with  usually  a  vitreous  or  greasy  lustre.  The  specific  gravity  of  the  lalCer  ores  is 
always  less  than  5.  The  whole  of  them,  excepting  the  chloride,  become  more  or  less 
speedily  black,  with  sulphureted  hydrogen  or  with  hydrosulphurets ;  and  are  easily 
reduced  to  the  metallic  state  upon  charcoal,  with  a  flux  of  carbonate  of  soda,  after  they 
have  been  properly  roasted.  They  diffuse  a  whitish  or  yellowish  powder  over  the 
charcoal,  which,  according  to  the  manner  in  which  the  flame  of  the  blowpipe  is  directed 
upon  it,  becomes  yellow  or  red ;  thus  indicating  the  two  characteristic  colors  of  the  oxydes 
of  lead. 

We  shall  not  enter  here  into  the  controversy  concerning  the  existence  of  native  lead, 
which  has  been  handled  at  length  by  M.  Brongniart  in  the  Dictimnaire  des  Sciences  Nat- 
urelles,  article  Plomb,  Mineralogie. 

The  lead  ores  most  interesting  to  the  arts  are  : — 

1.  Galena,  sulphuret  of  lead.  This  ore  has  the  metallic  lustre  of  lead  with  a  crystal- 
line structure  derivable  from  the  cube.  When  heated  cautiously  at  the  blowpipe  it  is 
decomposed,  the  sulphur  flies  oflf,  and  the  lead  is  left  alone  in  fusion ;  but  if  the  heat  be 
continued,  the  colored  surface  of  the  charcoal  indicates  the  conversion  of  the  lead  into 
its  oxydes.  Galena  is  a  compound  of  lead  and  sulphur,  in  equivalent  proportions,  and 
therefore  consists,  in  100  parts,  of  86f  of  metal,  and  13  §  of  sulphur,  with  which  numbers 
the  analysis  of  the  galena  of  Clausthal  by  Westrumb  exactly  agrees.  Its  specific  grav- 
ity, when  pure,  is  7'56.  Its  color  is  blackish  gray,  without  any  shade  of  red,  and  its  pow- 
der is  black,  characters  which  distinguish  it  from  blende  or  sulphuret  of  zinc.  Its  struc- 
ture in  mass  is  lamellar,  passing  sometimes  into  the  fibrous  or  granular,  and  even  compact. 
It  is  brittle.  The  specular  galena,  so  called  from  its  brightly  polished  aspect,  is  remark- 
able for  forming  the  sUckensides  of  Derbyshire — thin  seams,  which  explode  with  a  loud 
noise  when  accidentally  scratched  in  the  mine. 

The  argentiferous  galena  has  in  general  all  the  external  characters  of  pure  galena. 
The  proportions  of  silver  vary  from  one  fifth  part  of  the  whole,  as  at  Tarnowitz,  in  Sile- 
sia, to  three  parts  in  ten  thousand,  as  in  the  ore  called  by  the  German  miners  Weisgiilti- 
gerz ;  but  it  must  be  observed,  that  whenever  this  lead  ore  contains  above  5  per  cent,  of 
silver,  several  other  metals  are  associated  with  it.  The  mean  proportion  of  silver  in 
galena,  or  that  which  makes  it  be  considered  practically  as  an  argentiferous  ore,  because 
the  silver  may  be  profitably  extracted,  is  about  two  parts  in  the  thousand.  See  Silvkr. 
The  above  rich  silver  ores  were  first  observed  in  the  Freyberg  mines,  called  Himmels- 
furst  and  Bcschertgluck,  combined  with  sulphuret  of  antimony;  but  they  have  been  no- 
ticed since  in  the  Hartz,  in  Mexico,  and  several  other  places. 

The  antimonial  galena  (Boumonite)  exhales  at  the  blowpipe  the  odor  peculiar  to  anti 
niony,  and  coats  the  charcoal  with  a  powder  partly  white  and  partly  red.  It  usually  cob 
tains  some  arsenic. 


LEAD. 


31 


4 


2.  The  Se^eniuret  of  lead  resembles  galena,  but  its  tint  is  bluer.  Its  chemical  char 
acters  are  the  only  ones  which  can  be  depended  on  for  distinguishing  it.  At  tlie 
blowpipe  it  exhales  a  very  perceptible  smell  of  putrid  radishes.  Nitric  acid  liberates 
the  selenium.  When  heated  in  a  tube,  oxyde  of  selenium  of  a  carmine  red  rises  along 
with  selenic  acid,  white  and  deliquescent.  The  specific  gravity  of  this  ore  varies  from 
6*8  to  7*69. 

3.  Native  minium  or  red  lead  has  an  earthy  aspect,  of  a  lively  and  nearly  pure  red 
color,  hut  sometimes  inclining  to  orange.  It  occurs  pulverulent,  and  also  compact, 
with  a  fracture  somewhat  lamellar.  When  heated  at  the  blowpipe  upon  charcoal,  it  is 
readily  reduced  to  metallic  lead.  Its  specific  gravity  varies  from  4-6  to  8-9.  Ihis  ore 
IS  rare. 

4.  Plomb'gomme. — This  lead  ore,  as  singular  in  appearance  as  in  composition,  is 
of  a  dirty  brownish  or  orange-yellow,  and  occurs  under  ihe  form  of  globular  or  gum-like 
concretions.  It  has  also  the  lustre  and  translucency  of  gum ;  with  somewhat  of  a 
pearly  aspect  at  times.  It  is  harder  than  fluor  spar.  It  consists  of  oxyde  of  lead,  40 ; 
alumina,  37 ;  water,  18-8 ;  foreign  matters  and  loss,  4-06 ;  in  100.  Hitherto  it  has 
been  found  only  at  Huelgoet,  near  PouUaouen,  in  Brittany,  covering  with  its  tears  or 
small  concretions  the  ores  of  white  lead  and  galena  which  compose  the  veins  of  that 
lead  mine. 

5.  White  lead,  carbonate  of  lead.— This  ore,  in  its  purest  state,  is  colorless  and  trans, 
parent  like  glass,  with  an  adamantine  lustre.  It  may  be  recognised  by  the  following 
characters : — 

Its  specific  gravity  is  from  6  to  6*7 ;  it  dissolves  with  more  or  less  ease,  and  with 
effervescence,  in  nitric  acid ;  becomes  immediately  black  by  the  action  of  sulphureted 
hydrogen,  and  melts  on  charcoal  before  the  blowpipe  into  a  button  of  lead.  According  to 
Klaprolli,  the  carbonate  of  Leadhills  contains  82  parts  of  oxyde  of  lead,  and  16  of  car- 
bonic acid,  in  98  parts.  This  mineral  is  tender,  scarcely  scratches  calc-spar,  and  breaks 
easily  with  a  waved  conchoidal  fracture.  It  possesses  the  double  refracting  properly  in  a 
very  high  degree  ;  the  double  image  being  very  visible  on  looking  through  the  flat  faces 
of  the  prismatic  crystals.  Its  crystalline  forms  are  very  numerous,  and  are  referrible  to 
the  oclahedron,  and  the  pyramidal  prism. 

6.  Vitreous  lead,  or  sulphate  of  lead. — This  mineral  closely  resembles  carbonate  of 
lead ;  so  that  the  external  characters  are  inadequate  to  distinguish  the  two.  But  the 
following  are  sufficient.  When  pure,  it  has  the  same  transparency  and  lustre.  It  does 
not  eflervesce  with  nitric  acid  ;  it  is  but  feebly  blackened  by  sulphureted  hydros  en  ;  it 
first  decrepitates  and  then  melts  before  the  blowpipe  into  a  transparent  glass,  which  be- 
comes milky  as  it  cools.  By  the  combined  action  of  heat  and  charcoal,  it  passes  first  into 
a  red  pulverulent  oxyde,  and  then  into  metallic  lead.  It  consists,  according  to  Klaproth, 
of  71  oxyde  of  lead,  25  sulphuric  acid,  2  waler,  and  1  iron.  That  specimen  was  from 
Anglesea ;  the  Wanlockhead  mineral  is  free  from  iron.  The  prevailing  form  of  crjstal- 
lization  is  the  rectangular  octahedron,  whose  angles  and  edges  are  variously  modified. 
The  sulphato-carbonate,  and  sulphato  tri-carbonale  of  lead,  now  called  Leadhillite,  are 
rare  minerals  which  belong  to  this  head. 

7.  Phosphate  of  lead. — This,  like  all  the  combinations  of  lead  with  an  acid,  exhibits  no 
metallic  lustre,  but  a  variety  of  colors.  Before  the  blowpipe  upon  charcoal,  it  melts  into 
a  globule  externally  crystalline,  which,  by  a  continuance  of  the  heat,  with  the  addition  of 
iron  and  boracic  acid,  aifords  metallic  lead.  Its  constituents  are  80  oxyde  of  lead,  18  phos- 
phor c  acid,  and  1-G  muriatic  acid,  according  to  Klaproth's  analysis  of  the  mineral  from 
Wanlockhead.  The  constant  presence  of  muriatic  acid  in  the  various  specimens  exam- 
ined is  a  remarkable  circumstance.  The  crystalline  fonns  are  derived  from  an  obtuse 
rhomboid.  Phosphate  of  lead  is  a  little  harder  than  white  lead ;  it  is  easily  scratched, 
and  its  powder  is  always  gray.  Its  specific  gravity  is  6'9.  It  has  a  vitreous  lustre,  some- 
what adamantine.  Its  lamellar  texture  is  not  very  distinct ;  its  fracture  is  wavy,  and  it 
i.v  easily  frangible.  The  phosphoric  and  arsenic  acids  being,  according  to  M.  Milscher- 
lich,  isomoi-phous  bodies,  may  replace  each  other  in  chemical  combinations  in  every  pro- 
portion, so  that  the  phosphate  of  lead  may  include  any  proportion,  from  the  smallest  fmn 
tion  of  arsenic  acid  to  the  smallest  fraction  of  phosphoric  acid,  thus  graduating  indefi- 
nitely into  arseniate  of  lead.  The  yellowish  variety  indicates,  for  the  most  part,  the 
presence  of  arsenic  acid. 

8.  Muriate  of  lead.  Horn-lead^  or  murio-carlonate. — This  ore  has  a  ijale  yellow  color, 
is  reducible  to  metallic  lead  by  the  agency  of  soda,  and  is  not  altered  by  the  hydrosul- 
phurets. At  the  blowpipe  it  melts  first  into  a  pale  yellow  transparent  globule,  with  salt 
of  phosphorus  and  oxyde  of  copper;  and  it  manifests  the  presence  of  muriatic  acid  by  a 
bluish  flame.  It  is  fragile,  tender,  softer  than  carbonate  of  lead,  and  is  sometimes  almost 
colorless,  with  an  adamantine  lustre.  Spec,  srrav.,  606.  Its  constituents,  according  to 
Berzelius,  are  lead,  25-84  ;  oxyde  of  lead,  57-07;  carbonate  of  lead,  6-25;  chlorine,  8'-84; 
silica,  1-46;  water,  0-54  ;  in  100  parts.     The  carbonate  is  an  accidental  ingrojient,  not 


'  -rih' 


83 


LEAD. 


beinc:  in  equivalent  proportion.      Klaproth  found  chlorine,  13-67;  lead,  39-98  ;  oxyde  ol 
lead,"  22-57 ;  carbonate  of  lead,  23-78. 

9.  Jrsmiate  of  lead. — Its  color  of  a  pretty  pure  yellow,  bordering  slightly  on  the 
greenish,  and  its  property  of  exhaling  by  the  joint  action  of  fire  and  charcoal  a  very 
distinct  arsenical  odor,  are  the  only  characters  which  distinguish  this  ore  from  the  phos- 
phate of  lead.  The  form  of  the  arseniate  of  lead,  when  it  is  crystallized,  is  a  prism  with 
six  faces,  of  the  same  dimensions  as  that  of  phosphate  of  lead.  "When  pure,  it  is  redu- 
cible upon  charcoal,  before  the  blowpipe,  into  metallic  lead,  with  the  copious  exhalation 
of  arsenical  fumes ;  but  only  in  part,  and  leaving  a  crystalline  globule,  wiien  it  contains 
any  phosphate  of  lead.  The  arseniate  of  lead  is  tender,  friable,  sometimes  even  pulve- 
rulent, and  of  specific  gravity  5-04.  That  of  Johann-Georgenstadt  consists,  according  to 
Rose,  of  oxyde  of  lead  77*5;  arsenic  acid  12-5}  phosphoric  acid  7-5,  and  muriatic 

acid  1-5. 

10.  Red  lead,  or  Ckromate  of  had. — This  mineral  is  too  rare  to  require  consideration 
in  the  present  work. 

11.  Plornb  vauqtcelinite.    Chromaie  of  icad  and  copper. 

12.  Yellow  lead.     Molybdate  of  lead. 

13.  Tungstate  of  lead. 

Having  thus  enumerated  the  several  species  of  lead  ore,  we  may  remark,  that  galena 
is  the  only  one  which  occurs  in  sufficiently  great  masses  to  become  the  object  of  mining 
and  metallurgy.  This  mineral  is  found  in  small  quantity  among  the  crystalline  primitive 
rocks,  as  granite.  It  is  however  among  the  oldest  talc-schists  and  clay  slates,  that  it  usu- 
ally occurs.  But  galena  is  much  more  abundant  among  the  transition  rocks,  being  its 
principal  locality,  where  it  exists  in  interrupted  beds,  masses,  and  more  rardy  in  veins. 
The  blackish  transition  limestone  is  of  all  rocks  that  which  contains  most  galena ;  as  at 
Pierreville  in  Normandy ;  at  Clausthal,  Zellerfeldt,  and  most  mines  of  the  Harz  ;  at  Fahlun, 
in  Sweden ;  in  Derbyshire  and  Northumberlauid,  &c.  In  the  transition  graywacke  of  the 
south  of  Scotland,  the  galena  mines  of  Leadhills  occur.  The  galena  of  the  primitive 
formations  contains  more  silver  than  that  of  the  calcareous. 

The  principal  lead  mines  at  present  worked  in  the  world,  are  the  following:  ]. 
Poullaouen  and  Huelgoet  near  Carhaix  in  France,  department  of  Finisterre,  being  veins 
of  galena,  which  traverse  a  clay  slate  resting  upon  granite.  They  have  been  known  for 
ipwards  of  three  centuries ;  the  workings  penetrate  to  a  depth  of  upwards  of  300  yards, 
and  in  1816  furnished  500  tons  of  lead  per  annum,  out  of  which  1034  pounds  avoirdu- 
pois of  silver  were  extracted.  2.  At  Villeforte  and  Viallaz,  department  of  the  Lozere, 
are  galena  mines  said  to  produce  100  tons  of  lead  per  annum,  with  400  kilogrammes  of 
silver  (880  lbs.  avoird.).  3.  At  Pezey  and  Macot,  to  the  east  of  Moutiers  in  Savoy,  a 
galena  mine  exists  in  talc-schist,  which  has  produced  annually  200  tons  of  lead,  and 
about  600  kilogrammes  of  silver  (1320  lbs.  avoird.).  4.  The  mine  of  Vedrin,  near 
Namur  in  the  Low  Countries,  is  opened  upon  a  vein  of  galena,  traversing  compact  lime- 
stone of  a  transition  district ;  it  has  furnished  200  tons  of  lead,  from  which  385  pounds 
avoird.  of  silver  were  extracted.  5.  In  Saxony  the  galena  mines  are  so  rich  in  silver  as 
to  make  the  lead  be  almost  overlooked.  They  are  enumerated  under  silver  ores.  6.  The 
lead  mines  of  the  Harz  have  been  likewise  considered  as  silver  ores.  7.  Those  of  Bley- 
berg  in  the  Eifel  are  in  the  same  predicament.  8.  The  galena  mines  of  Bleybcrg  and 
Vilfach  in  Carinthia,  in  compact  limestone.  9.  In  Bohemia,  to  the  south-west  cf  Prague. 
10.  The  mines  of  Joachimsthal,  and  Bleystadt,  on  the  southern  slope  of  the  Erzgcbirgc, 
produce  argentiferous  galena.  11.  There  are  numerous  lead  mines  in  Spain,  the  most 
important  being  in  the  granite  hills  of  Linares,  upon  the  southern  slope  of  the  Siena 
Morer.a,  and  in  the  district  of  the  small  town  of  Canjagar.  Sometimes  enormous  masses 
of  galena  are  extracted  from  the  mines  of  Linares.  There  are  also  mines  of  galena  in 
Catalonia,  Grenada,  Murcia,  and  Abneria,  the  ore  of  the  last  locality  being  generally  poor 
in  silver.  12.  The  lead  mines  of  Sweden  are  very  argentiferous,  and  worked  chiefly  with 
a  view  to  the  silver.  13.  The  lead  mines  of  Daouria  are  numerous  and  rich,  lying  in  a 
transition  limestone,  which  rests  on  primitive  rocks ;  their  lead  is  neglected  on  account 
of  the  silver. 

14.  Of  all  the  countries  in  the  world,  Great  Britain  is  that  which  annually  produces  the 
fi:realest  quantity  of  lead.  Accord^"  ig  to  M.  Villefosse,  in  his  Richesse  Minerale,  published 
in  1810,  we  had  furnished  every  .M^r  12,500  tons  of  lead,  whilst  all  the  rest  of  Europe 
taken  together,  did  not  produce  so  much ;  but  from  more  recent  documents,  that  estimate 
seems  to  have  been  too  low.  Mr.  Taylor  has  rated  the  total  product  of  the  United  Eong- 
dora  per  annum  at  31,900  tons,  a  quantity  fully  2|  times  greater  than  the  estimate  of 
Villefosse  (see  Conybeare  and  Phillips's  Geology,  p.  354).  Mr.  Taylor  distributes  this 
product  among  the  different  districts  as  follows : — 


LEAD. 


33 


V 


Wales,  (Flintshire  and  Denbighshire)        -        .        -        -        , 

Scotland,  (in  transition  graywacke)         -        -        . 

Durham,  Cumberland,  and  Yorkshire,  (in  carboniferous  lime)' 

Derbyshire,  (probably  in  carboniferous  lime)  -        -        -        . 
Shropshire        -        -         -        _        .        ._ 

Devon  and  Cornwall,  (transition  and  primitive"  rocks)      -        '• 


Tons. 

7,500 

2,800 

19,000 

1,000 

800 

800 


Total        -       -       -       .       .  Ol  Qfto 

YoTk  fur„°ir„fVv.*  Cumberland,  and  the  adjacent  parts  of  the  bounties  of  DuZm  and 
York,  furnish  of  themselves  nearly  three-fifths  of  the  total  product     Derbyshire  vZ, 

ir"elns^in'Mlrr/™tf '*'•    •^"  ?°™"''"  ""J  D-onsGire  the  lead  o  e  i  7oZ 
^^^Sz^-^^^=^^^^^^.  -  SfoeT-n" th^etr Sfit 

ifr.r^rni:i«t=^^^^^^^^ 

Beaumont  alone,  yeldmg  10,000.    In  1847,  the  totil  produce  was  ^  follows'^ 


England 
Wales  - 
Ireland 
Scotland 
Isle  of  Man 


Total 


Lead  Ore. 


Tons. 

69,614i 

18,147j 

2,251 

1,159 

2,575 


Lead. 


83,747 


Tons. 

89,507  i 

12,294 

1,380 

822| 

1,699 


55,703 


The  English  lead-miners  distinguish  three  different  kinds  of  deposites  of  lead  ore- 
[^^""TZ'  PlP';'''^^  '-^^d  fat-veins  The  English  word  vein  corresponds  to  the  FrS 
IlMh?^'  -t  TfK-  ""^^^  "il^  °^  '^  indifferently  in  England  and  France,  to  inSe 
all  the  deposites  of  this  ore,  addmg  an  epithet  to  distinguish  the  different  forms  thus 
^■ake  veins  are  true  veins  in  the  geological  acceptation  of  the  word  ve[n ;  V^Sn.  S 
masses  usually  very  narrow,  and  of  oblong  shape,  most  frequently  paral  el  fo  the  pla^ 
thele  strata  ^  '  ^^'^  •^^'-'^"'"  ^^  ^^^"  ^^  of  ores  interposed  in  the  middle  ^T 

Rake-veins  are  the  most  common  form  in  which  lead  ore  occurs  in  Cumberland. 
They  are  i"  general  narrower  in  the  sandstone  which  covers  the  limestone,  than  in  \he 
calcareous  beds.  A  thickness  of  less  than  a  foot  in  the  former,  becomes  sudde^y  3  or 
4  feet  m  the  latter;  in  the  rich  vein  of  Hudgillburn,  the  thickness  is  17  feet  L  the 
Great  h^ncstcme,  while  it  does  not  exceed  3  feet  in  the  overlymg  Watersill  or  sandTtone 
This  influence  exercised  on  the  veins  by  the  nature  of  the  enclosing  rock,  is  instructive 
rt  determines  at  the  same  time  almost  uniformly  their  richness  in  lead  ore,  an  obse^atlon 

TNorwav"  Th   r  'k'T '.''  '^  '^'"  '°""^T'  ^^^^^^^^^  ^"  ^^^  vein^  of  Kongsbi^ 

h  J;.T^*     The  Cumberland  vems  are  constantly  richer,  the  more  powerful  they  are  in 

the  portions  which  traverse  the  calcareous  rocks,  than  in  the  beds  of  sandstone  and^'ore 

for  Jh^e  ve  '  '^^  -'"'i^r '  '"'H  .  ^'-  ^'  """""^  ^^  ^'^  ^«^^  ^^11^  P^'  (-  «ol^d  'sla'y  Say^ 
tL  unlr^^,.  include  any  ore;  it  is  commonly  filled  with  a  species  of  potter's  earth 

most  Tfh .?  '^^''l^^'  • '^  ^^'^  '"^  ^^''^'^^  "'^''^  productive  than  the  lower  ones.  In 
??h!  r^  r  fu  ""'"i^''  ^^^  ^'^''''  ^""^^  "°^  '^°^^«^  ti^l  lately  below  the  fifth  calcareous  bed 
(the  four-fathom  Imiestone),  which  is  307  yards  beneath  the  mDl-stone  grit!  and  as  the 

of   h  ""^^^^^^  ''^  >"^^^  \^"^n^  ij'  1^  f«»o^^  that  the  thickness  o?  the  p^' 

or  tne  ground  where  the  veins  are  rich  m  lead  does  not  in  general  exceed  ^oo  vards      It 

TrSTo  threw'rh  'T  '^^"  ''^"  °^^"^'^"  ^^^  neighbourhood  oSon  Mo'oMown 
Tder  tl  mil' Z^^^  ^°"«°  limestone,  which  is  418  yanls 

they  hate  blen  fonow^H  i.  '  T^/Tr ''""'  immediately  above  the  whin-siU ;  and'thal 
whTchl  onlv  83  vn^^^^^^^  ^''^  limestone  stratum,  as  high  as  the  grindstone  siU, 

tTSess  of  the  ZmbJr  '^^  "^T  stratum  of  mill-stone  grit;  so  that  in  the  totS 
asserted  that  \etdv^.^[^''"K  ^^^^^^^lon  there  is  more  than  336  yards.      It  has  been 

sidls^'blin^'not  T^f'^T  °t  ^  '''^"  ^^^"'  P^^^^  commonly  in  the  points  where/Its  t^ 

Xnone?ur.//i      ^^'''^^^^^^       ^^^  ^^  ^°<^>^ '*  ^^^  its  impoverishment  LuS 

Vol  U         '^^'^'"'''^  ^"'^  *^^  ^^^  V  ''^^'*'''  "^^y-      '^^^  ^"^'^^«  which  m^ 


'I 


III 


M 


LEAD. 


frequently  accompany  the  galena,  are  carbonate  of  lime,  fluate  of  lime,  snlphate  of 
bar>ta,  quartz,  and  pyrites. 

The  pipe-veins  (amas  in  French)  are  seldom  of  great  length ;  but  some  have  a  con- 
siderable width ;  their  composition  being  somewhat  similar  to  that  of  the  rake-veins. 
They  meet  commonly  in  the  neighborhood  of  the  two  systems,  sometimes  being  in  evident 
communication  together ;  they  are  occasionally  barren ;  but  when  a  wide  pipe-vein  is 
metalliferous,  it  is  said  to  be  very  productive. 

The  Jlat  veins,  or  .sirata  veins,  seem  to  be  nothing  else  than  expansions  of  the  matter 
of  the  vein  between  the  planes  of  the  sirata ;  and  contain  the  same  ores  as  the  veins  in 
their  vicinity.  When  they  are  metalliferous,  they  are  worked  along  with  the  adjacent 
rake  vein  ;  and  are  productive  to  only  a  certain  distance  from  that  vein,  unless  they  get 
enriched  by  crossing  a  rake  vein.  Some  examples  have  been  adduced  of  advantageous 
workings  in  flat  veins  in  the  great  limestone  of  Cumberland,  particularly  in  the  mines  of 
Coalcleugh  and  Nenthead.  The  rake  veins,  however,  furnish  th«  greater  part  of  the 
lead  which  Cumberland  and  the  adjacent  counties  send  every  year  into  the  market.  Mr. 
Forster  gives  a  list  of  165  lead  mines,  which  have  been  formerly,  or  are  now,  worked  in 
that  district  of  the  kingdom. 

The  metalliferous  limestone  occupies,  in  Derbyshire,  a  length  of  about  25  miles  from 
north-west  to  south-east,  under  a  very  variable  breadth,  which  towards  the  south, 
amounts  to  25  miles.  Castleton  to  the  north,  Buxton  to  the  north-west,  and  Matlock 
to  the  south-east,  lie  nearly  upon  its  limits.  It  is  surrounded  on  almost  all  sides  by  the 
mill-stone  grit  which  covers  it,  and  which  is,  in  its  turn,  covered  by  the  coal  strata. 
The  nature  of  the  rocks  beneath  the  limestone  is  not  knoAvn.  In  Cumberland  the 
metalliferous  limestone  includes  a  bed  of  trap,  designated  under  the  name  of  whinsill. 
In  Derbyshire  the  trap  is  much  more  abundant,  and  it  is  thrice  interposed  between  the 
limestone.  These  two  rocks  constitute  of  themselves  the  whole  mineral  mass,  through  a 
thickness  of  about  550  yards,  measuring  from  the  millstone  grit ;  only  in  the  upper 
portion,  that  is  near  the  millstone  grit,  there  is  a  pretty  considerable  thickness  of  ar- 
gillo-calcareous  schists. 

Four  great  bodies  or  beds  of  limestone  are  distinguishable,  which  alternate  with 
three  masses  of  trap,  called  toadstone.  The  lead  veins  exist  in  the  calcareous  strata, 
but  disappear  at  the  limits  of  the  toadstone.  It  has  now  been  ascertained,  however, 
that  they  recur  in  the  limestone  underneath. 

LEAD  IN  THE  Exhibition.— Sopwith,  Thomas,  F.  R.  S.,  Ac.  AUenheads,  Northumber- 
land, inventor  and  producer. 

Specimens  of  lead  ores  and  associated  minerals,  with  examples  of  the  various  stages 
of  progress  from  their  being  excavated  in  the  mine  and  carried  through  the  several  de- 
partments of  washing  and  smelting,  until  furnished  and  ready  for  the  market  in  the 
form  of  a  cake  of  silver  and  a  pig  or  piece  of  lead  known  as  W.  B.  lead. 

The  specimens  of  minerals  usually  associated  with  lead  ores  are  collected  from  va- 
rious mines,  and  are  fitted  together  in  a  separate  ease,  under  the  direction  of  the  ex- 
hibitor, by  Messrs.  Cain  and  Wallace  of  Nenthead,  and  otheis. 

The  general  arrangement  of  the  strata  in  which  these  ores  and  minerals  are  found  b 
exhibit~ed  by  a  section  of  part  of  the  lead  mining  district  belonging  to  Wentworth 
Blackett  Beaumont,  Esq.,  at  Allenheads,  in  the  county  of  Northumberland,  and  from 
whose  mines  the  specimens  of  lead  ores  and  examples  of  process  during  conversioa 
into  lead  and  silver  are  taken ;  and  a  further  illustration  of  the  geographical  struc- 
ture of  this  part  of  England  is  given  by  an  isometrical  plan  and  section  by  the  exhibit- 
or, showing  a  considerable  tract  of  mining  ground  in  the  manor  of  Alston  Moor,  in 

the  county  of  Cumberland.  •       v-  u 

The  principal  phenomena  of  mineral  veins  and  displacement  of  the  strata  in  which 
lead  ore  is  obtained  in  the  north  of  England  are  shown  by  dissected  models,  invented 
by  the  exhibitor,  and  examples  of  the  finished  products  are  contained  in  a  separate  case, 
fiom  Mr.  Beaumont's  smelt-mills,  under  the  direction  of  his  agent,  Mr.  Thomas  SteeL 
This  collection,  the  general  nature  of  which  is  here  briefly  indicated,  is  mtended  to 
illustrate  the  geological  position  and  usual  products  of  the  north  of  England  lead  mines. 
The  following  is  the  order  of  the  five  several  portions,  and  which  are  more  particu- 
larly described  under  these  several  heads  in  the  sequel. 

1.  Sections  of  strata  at  Allenheads  and  Alston. 

2.  Models  to  illustrate  mineral  veins,  <fec. 

3.  Minerals  associated  with  lead  ores. 

4.  Examples  of  the  various  stages  of  progress  from  the  mine  to  the  market 
6.  Lead  and  silver  prepared  for  sale. 

1.  As  the  express  object  of  this  collection  is  to  afford  a  general  view  of  the  whole  of 
the  principal  features  relative  to  the  extensive  and  important  departments  of  British 
industry  connected  with  lead  mining,  and  as  this  information  is  more  expressly  intended 
for  the  use  of  those  who  are  not  locally  conversant  with  the  physical  conditions  under 


I 


LEAD. 


85 


which  lead  ores  are  usually  obtained,  the  exhibitor  has  in  the  first  instance  thought 
it  necessary  to  pi-esent  clear  and  distinct  views  of  the  geological  structure  of  the  dis- 
tricts in  which  the  chief  lead  mines  of  the  north  of  England  are  situated,  in  order  that, 
without  going  into  purely  technical  details,  which  are  only  of  local  interest^  the  sev- 
eral strata  and  order  of  superposition  may  be  readily  understood. 

As  an  approximate  comparative  view  of  the  produce,  it  may  be  considered  that  the 
lead  raised  in  Mr.  Beaumont's  mines  amounts  to  about  one-fourth  of  the  quantity 
raised  in  England,  about  one-sixth  of  the  produce  of  Great  Britain,  and  about  one- 
teuth  of  that  of  the  whole  of  Europe,  including  the  British  Isles.  They  have  been 
extensively  worked  from  time  immemorial ;  i)art  of  them  are  situated  in  the  manora 
bclont^HiiX  to  Mr.  Beaumont,  in  the  dales  of  East  and  West  Allen,  in  the  south-west 
part  of  Northumberland,  and  others  aie  situated  in  the  wild  district  of  moors  which 
forms  the  western  extremity  of  the  count}-  of  Durham. 

This  part  of  the  country  happens  to  be  at  once  the  centre  of  the  island  of  Great 
Britain,  and  by  far  the  most  elevated  part  of  it  which  is  thickly  populated  ;  for,  scat- 
tered over  hills  and  dales,  which  present  an  aspect  of  verdant  cultivation  mixed  with 
heathy  moors,  are  to  be  found  some  thousands  of  inhabitants,  nearly  the  whole  of 
them  either  employed  in  lead  mines  or  smelting-mills,  or  indirectly  deriving  a  liveli- 
hood from  some  connection  witli  lead-mining  business.  Allenheads  formsli  central 
position  in  the  midst  of  these  mines;  and  the  agent's  house,  sliown  on  the  section,  is 
exactly  1400  feet  above  the  level  of  the  sea,  and  is  the  highest  house  of  its  magni- 
tude in  Great  Britain ;  nor  are  many  of  the  cottages  of  shepherds  and  other  moor 
land  habitations  of  greater  elevation. 

The  datura  or  base  line  of  the  Allenheads  section  is  700  feet  above  the  level  of  the 
sea.  The  drawing,  164  feet  in  length,  is  on  a  true  scale  of  100  feet  to  an  inch;  by  a 
true  scale  being  meant,  that  the  lengths  and  heights  are  projected  to  the  scale  or  pro- 
portion, so  that  a  true  miniature  profile  of  the  country  is  given,  as  well  as  a  correct 
red'.iction  of  the  relative  size  of  the  various  rocks.  The  extent  of  country  thus  shown 
is  not  quite  4  miles,  being  3  miles  1220  yard'^. 

The  spectator  is  supposed  to  be  looking  to  the  north,  and  the  section  commences  at 
a  point  about  half  a  mile  eastward  fio:n  a  place  called  Kilhope  Head,  which  is  con- 
spicuously marked  in  all  English  maps,  inasmuch  as  the  three  counties  of  Northumber- 
land, Durham,  and  Cumberland  all  meet  in  one  spot  At  about  three  quartei-s  of  a 
mde  fi-oin  the  point  of  comraencemGnt  the  section  represents  the  hill  called  Kilhope 
Law ;  It  is  on  the  boundary  line  of  the  counties  of  Northumberland  and  Durham,  and  is 
the  highest  point  of  land  in  the  hist-named  county,  being  2206  feet  above  the  level  of 
the  sea  But  out  of  the  limits  of  this  section,  and  about  10  miles  south-west  from  Kil- 
hope Law,  the  same  strata  which  are  here  delineated  reach  an  altitude  of  2901  feet 
above  the  sea,  and  this  is  the  highest  elevation  attained  bv  the  rocks  which  form  the 
carboniferous  or  mountain  limestone  of  the  north  of  England. 

Such  being  the  stratification  of  the  central  portion  of  tie  narrow  part  of  the  island 
of  which  the  coal  fields  of  the  Tyne  and  Wear  form  the  extremity  on  the  east  border- 
ing on  the  German  Ocean,  for  some  distance  north  and  south  of  Newcastle,  while  a 
similar  coal  field  is  found  at  the  western  extremity  near  Whitehaven,  it  may  be  ob- 
served with  i-eference  to  these  coal  fields,  that  they  lie  over  or  upon  the  mountain 
limestone  formation.  The  coal  beds  so  extensively  worked  in  the  Newcastle  and  Dur- 
ham coal  mines  or  collieries,  gradually  rise  to  the  Avest  and  one  by  one  crop  out  or 
bassett  according  to  the  undulations  of  the  country.  At  length,  at  about  20  miles 
west  of  the  German  Sea,  the  lowest  of  the  coal  beds^  crops  outi^  and  from  beneath  it 
gradually  appear  the  limestone  strata,  which  continue  to  rise  nearly  coincident  with 
the  general  rise  of  the  country,  until  they  reach  the  summit  of  Cross  Fell  (2901  feet) 
And  this  general  and  very  gradual  inclination  of  the  strata,  a  feature  of  the  trreatest 
importance  in  practical  mining,  is  clearly  and  accurately  delineated  in  this  section. 

In  a  thickness  of  about  2000  feet  of  the  alternating  beds  of  sandstone,  clay  and 
limestone,  which  form  the  strata  of  the  mining  districts  of  Alladale,  Alston,  and  Wear- 
dale,  there  IS  one  single  stratum  of  limestone,  called  the  "great  limestone,"  the  veins  in 
whicfi  have  produced  neariy,  if  not  quite,  as  much  ore  as  all  the  other  strata  put  to- 
gether. This  stratum  is  delineated  on  the  section,  and  may  he  observed  lyinc^  at  a 
depth  of  about  850  feet  below  the  summit  of  Kilhope  Law.  Somewluv  ex<-eedin"^  two 
miles  eastward  of  this,  at  Allenheads,  the  top  of  the  irreat  limestone  is  280  feet'from 
the  top  of  a  shaft  called  Gin-IIill  Shaft  Its  thickness,  which  is  tolerably  uniform  over 
several  hundred  square  miles  of  country,  is  about  60  feet ;  and  it  is  from  tliis  stratum 
of  limestone  that  nearly  all  the  specimens  in  this  collection  have  been  obtained. 

1  he  dislocations  of  strata  which  constitute  for  the  most  part  impo.  taut  mineral  veins 
are  exhibited  more  m  detail  in  the  series  of  geoloirical  models  which  form  a  part  of 
this  collection :  but  some  of  the  great  features  of  displacement  may  be  noticed  on  the 


«6 


LEAD. 


LEAD. 


87 


11 


At  about  a  quarter  of  a  mile  to  the  wost  of,  or  left  hand  direction  from  Kilhope  Law, 
the  great  limestone,  and  all  other  associated  beds,  are  thrown  down  a  depth  of  about 
150  feet  for  a  space  of  nearly  700  feet ;  and  again,  at  the  distance  of  nearly  a  mile  from 
Allenheads,  a  vast  dislocation  takes  place,  by  which  the  great  limestone,  it  will  be  seen, 
is  brought  nearly  to  the  surface,  the  amount  of  displacement  being  about  400  feet.  It 
is  in  the  great  limestone  that  by  far  the  most  extensive  portion  of  the  workings  of  Al- 
lenheads  lead  mines  are  situated,  and  the  galleries  drawn  on  the  section  convey  a  gen- 
eral idea  of  the  position  of  the  mines.  In  a  great  thickness  of  strata  above  the  gieat 
limestone,  only  two  beds  of  that  rock  are  found.  One  of  these  is  called  "little  lime- 
stone." It  is  from  10  to  12  feet  thick,  and  is  75  feet  above  the  top  of  the  great  lime- 
stone. The  other  is  still  more  inconsiderable,  being  only  3  or  4  feet  thick,  and  is  440 
feet  above  the  great  limestone.  It  is  remarkable  with  what  exactness  this  thin  bed  is 
found  near  the  summit  of  hills,  the  intervening  spaces  having  apparently  been  removed 
by  denudation,  so  as  to  form  in  one  case  a  gap  of  6i  miles,  and  in  another  of  1^  miles, 
in  which  the  Tell  Top  limestone  is  entirely  cut  off. 

But  beneath  the  great  limestone,  as  will  be  seen  by  the  lines  of  blue  color,  are  seve- 
ral beds  of  the  same  description  of  rock,  viz.,  at  distances  respectively  of  30, 106,  190, 
250,  and  287  feet,  and  the  thickness  2,  24, 10,  15,  and  35  feet  These  are  known  by  de- 
Bcriptive  local  names,  and  comprise  all  that  are  of  significance  as  regards  lead-mining 
operations. 

The  Allenheads  mines  being  situated  for  the  most  part  at  depths  from  the  surface 
varying  from  200  to  600  feet,  are  drained,  partly  by  ordinary  water-wheels,  some  of 
which  are  shown  on  the  section,  and  partly  by  the  new  hydraulic  engines  invented  by 
Mr.  W.  G.  Armstrong,  and  four  of  which  are  now  used  for  draining  and  other  mining 
purposes  at  Allenheads  mines. 

Examples  of  the  various  Stages  of  Progress  from  the  Mine  to  the  Market. — ^This  part 
of  the  collection  is  arranged  in  five  cases,  each  containing  six  boxes  of  one  square  foot 
each,  being  in  all  thirty  boxes. 

Fifteen  of  these  boxes,  in  a  line  furthest  from  the  front  edge  of  the  counter,  contain 
specimens  of  lead-mining  from  the  excavation  of  the  ore  in  the  mine,  and  showing  the 
several  stages  of  progress  until  ready  to  send  to  the  smelt  mill ;  and  the  other  fifteen 
boxes,  in  a  line  nearest  to  the  front  of  the  counter,  contain  sptoimens  of  the  ore  as 
prepared  for  smelting,  and  its  various  stages  of  progress  until  manufactured  into  load 
and  the  silver  separated ;  these  finished  products  being  contained  in  division  No  5.  of 
this  collection. 

Case  No.  1. — Lead  ore,  as  first  separated  from  the  vein  in  which  it  is  found,  and 
which  in  this  state  is  called  "  bouse  "  in  the  north  of  England  lead  mines,  and  the  places 
in  which  it  is  deposited  at  the  surface  are  called  bouse  teams.  The  depositing  of  the 
ore  in  these  places  is  gro  itly  facilitated  at  Allenheads  by  the  use  of  tipping-frames  of  a 
new  construction,  by  Mr.  W.  G.  Armstrong,  of  the  Elswick  Engine  Works,  near  New- 
castle-on-Tyne.  This  example  is  from  a  "flats"  vein  in  Allenheads  mines  in  the  great 
limestone,  which  rock  forms  the  curiously  laminated  matrix  with  which  the  ore  is  inter- 
mixed. The  ore  and  rock  thus  intermixed  require  to  be  separated  as  is  exhibited  by  the 
following  examples.  By  a  flat  vein,  or  "flats,"  is  meant  a  horizontal  extension  of 
mineral  substances  to  a  considerable  distance  from  the  ordinary  vertical  or  steeply- 
inclined  veins,  which  extend  in  the  manner  of  fissures  through  the  various  beds  of  rock 
fonning  the  district  The  regular  lamination  of  the  ore  ia  worthy  of  attention,  as  leadino^ 
to  speculations  on  the  origin  of  mineral  veins;  a  subject  of  great  practical  importance. 
The  example  here  shown  is  taken  from  a  part  of  the  "flat  workings"  at  a  distance  of 
about  20  feet  from  the  principal  or  nearly  vertical  part  of  the  vein. 

Case  No.  2. — Bouse,  or  lead  ore,  as  extracted  from  the  vein,  and  showing  an  example 
of  the  curiously  polished  surface,  which  is  a  frequent  characteristic  of  veins,  and  which 
would  appear  at  first  sight  to  have  been  very  carefully  polished  by  artificial  means, 
many  of  the  surfaces  being  sufficiently  clear  to  reflect  the  images  of  objects  in  a  tolera- 
bly definite  form.  The  local  name  of  such  bright  and  polished  surfaces  is  ''slickcn- 
sides;"  and  the  suggestion  mentioned  in  the  notice  of  the  last  specimen  as  to  the  value 
of  scientific  inquiry  applies  with  still  greater  force  to  the  class  of  phenomena  of  which 
this  is  one  of  the  most  curious  indications. 

Case  No.  3.  contains  a  portion  of  the  ordinary  bouse  or  ore  as  newly  worked  from 
the  vein,  and  much  intermixed  with  the  materials  contained  in  Cases  1.  and  2.,  as  well 
as  with  other  eartliy  and  sparry  contents  of  veins.  The  produce  of  mineral  veins  va- 
ries from  pure  galena,  of  which  some  species  are  shown,  to  masses  of  rock  in  spar,  in 
which  the  ore  is  so  thinly  disseminated  as  not  to  repay  the  trouble  of  extraction. 

Case  No.  4. — The  intermixed  rocks  and  ores  shown  in  preceding  cases  are  first  sub- 
jected to  "  picking"  and  then  to  "washing"  on  a  grate.  The  first  of  these  operations 
separates  from  the  general  mass  all  such  pieces  of  galena  as  are  either  not  mixed  with 
other  substances,  or  which  can  be  readily  separated  with  a  hammer  on  what  are  called 


"  knocking  stones ;"  and  the  second  has  the  eff^ect  of  clearing  away  all  earthy  matter. 
These  specimens,  picked  from  the  heap  and  washing-grate,  are  reaay  for  smelting  after 
being  reduced  with  a  hammer  to  the  size  of  the  ore  contained  in  Case  No.  9. 

Case  No.  5  contains  ordinary  bouse  or  lead  ore  taken  from  the  trunking-box  after 
passing  through  the  washing-grate,  being,  in  fact  a  process  of  loashing  and  sizing  with 
a  view  to  the  further  operations  exhibited  in  the  following  cases. 

Case  No.  6  contains  specimens  of  ordinary  bouse,  which,  from  the  size  of  the  pieces 
and  intennixture  of  rock  and  ore,  require  to  be  passed  through  the  rollers  of  the 
crushing-milL 

Case  No.  7. — Specimens  of  the  same  bouse  or  ore  after  having  passed  through  the 
rollers  of  the  crushing-milL 

Case  No.  8. — So  far  the  processes  have  consisted  simply  of  extraction  of  the  ore 
from  its  place  in  the  mine,— of  the  pure  samples  of  ore  being  picked  out  and  washed 
and  sized  ready  for  being  smelted  at  once  without  further  operations, — of  the  remain- 
der of  poorer  samples  being  washed  and  separated  by  an  iron  grate  or  sieve  into  two 
sizes,  the  larger  having  to  be  ground  between  rollers  to  reduce  it  to  the  same  size  as 
the  smaller,  which  had  passed  the  grate;  and  when  reduced  to  this  stage,  the  whole 
is  ready  for  an  operation  called  "  botching,"  which  consists  in  placing  the  ore  in  a  tub 
with  water.  Tlie  bottom  of  this  tub  is  a  sieve, — and  the  whole  is  subjected  to  a  rapid 
vibratory  vertical  movement  or  shaking,  by  which  a  separation  of  the  ore  takes  place. 
The  water  so  far  lessens  the  weight  as  greatly  to  facilitate  the  downward  movement  of 
the  ore,  which  of  course  is  much  heavier  than  the  spar  and  other  materials  connected 
with  it  The  vibratory  movement  is  sometimes  given  by  manual  labor ;  a  long  arm 
moving  with  a  spring  is  jerked  up  and  down  by  a  strong  lad  jumping  on  a  raised  stand 
so  as  to  produce  the  required  motion.  The  same  results  may  be  obtained  by  machin- 
ery ;  and  a  model  of  a  botching  apparatus  accompanies  these  specimens.  It  repre- 
sents the  mode  in  which  the  botching  tubs  are  worked  in  some  of  Mr.  Beaumont's 
mines  in  West  Allendale :  and  both  the  mode  of  applying  the  machinery,  and  the 
manufacture  of  the  model  representing  it,  are  due  to  the  ingenuity  of  Mr.  Joseph 
Iletherington,  one  of  the  engineers  or  wrights  employed  at  these  mines. 

The  ore  is  prepared  as  has  already  been  described ;  and  after  being  shaken  in  the 
"  botching  tub,"  the  upper  part  is  entirely  waste  or  refuse,  and  is  called  "cuttings,"  of 
which  this  case,  No.  8,  contains  a  specimen. 

Case  No.  9  contains  lead  ore  as  obtained  from  the  bottom  of  the  hotching-tub,  and  is 
ready  for  being  smelted. 

Case  No.  10  contains  what  is  called  "  undressed  smcddum,"  being  what  has  passed 
through  the  sieve  of  the  hotching-tub  into  the  box  or  case  of  water  in  which  the  hotch- 
iug-tub  vibrates. 

Case  No.  11  is  the  "smeddura,"  after  being  dressed  or  cleared  from  all  foreign  sub- 
stances in  what  is  locally  called  a  "  buddle,"  and  the  ore  in  being  so  washed  is  said  to 
be  "  huddled." 

Case  No.  12.  In  all  operations  where  a  stream  of  running  water  is  employed  to 
wash  lead  ore,  it  is  obvious  that  many  of  the  smaller  particles  will  be  carried  away 
with  the  stream.  These  particles  are  allowed  to  settle  by  their  specific  gravity  in  what 
are  called  slime  pits,  being  merely  reservoirs  in  which  the  water  passes  over  a  long 
space  with  a  very  tranquil  movement  In  the  Case  No.  12  is  an  example  ol  the 
slime  or  deposit  in  these  slime  pits  undressed. 

Case  No.  13  contains  a  specimen  of  what  is  called  slime  ore,  having  been  extracted 
or  separated  from  the  slime  shown  in  Case  No.  12.  The  separation  is  effected  by  manu- 
al labor  in  what  are  called  "  nicking-trunks,"  and  is  made  ready  for  a  final  washing  or 
separation  in  the  "  dolly-tub." 

Case  No.  14  contains  slime  obtained,  not  by  manual  labor,  but  by  means  of  a  pa- 
tented invention  of  Mr.  Bruton's,  by  which  the  slime,  being  first  freely  mixed  with 
water,  is  allowed  on  a  revolving  canvas  cloth,  inclined  at  a  moderate  angle,  and  upon 
which  also  drops  of  water  are  constantly  falling  so  as  to  keep  the  surface  well  wetted. 
Heavier  particles,  being  thus  free  to  move,  are  carried  up  the  slightly  inclined  sur- 
face of  the  canvas,  and  pass  round  a  roller  to  a  cistern  below,  in  which  they  are  de- 
posited while  the  lighter  particles  of  earthy  matter  and  spar  are  at  once  carried  down 
the  canvas  by  the  stream  of  water.  The  ore  thus  obtained  requires  finally  to  be  wash- 
ed in  the  dolly-tub,  after  which  it  is  fit  for  being  smelted. 

Case  No.  15  contains  slime  ore  as  taken  from  the  dolly-tub,  which  is  the  last  opera- 
tion connected  with  the  washing  and  dressing  of  lead  ores  as  usually  practiced  in  the 
lead  mines  belonging  to  Mr.  Beaumont,  and  in  the  lead  mines  generally  of  this  part 
of  the  kingdom. 

The  German  buddle  is  also  occasionally  used  in  dressing  slime  ores.  A  considerable 
improvement  was  made  in  this  apparatus  about  thirty  years  ago  by  Mr.  Robert  Stagg, 
of  Middleton-in-Teesdale. 

/ 


S8 


LEAD. 


a 


Case  No.  16  exhibits  a  spcciraen  of  "selected"  or  superior  lead  ore  in  the  form  in 
which  it  is  sent  to  and  deposited  at  tJie  smelt  mill  ready  to  be  smelted. 

Case  No.  17  contains  an  example  of  the  ordinary  or  common  lead  ore  as  prepared 
and  ready  for  smelting. 

Cases  Nos.  18  and  19  contain  the  same  ores  (selected  and  common),  after  having  un- 
dergone the  operutioa  of  being  "  roasted,"  or  exposed  to  suitable  temperature  in  a 
reverberatory  furnace,  the  object  being  to  free,  it  from  tiie  sulphur  contained  in  the 
galena,  pure  specimens  of  which  consist  of  lead  86'6  and  sulphur  13-3. 

By  this  process  the  ore  is  rendered  more  easily  reducible.  ♦ 

Case  No.  20.  Gray  slags  formed  in  the  process  of  ore  hearth  smelting,  and  from 
which  the  lead  is  afterwards  obtained  at  the  slag  hearth. 

Case  No.  21.  Black  slags  being  the  residuum  obtained  from  the  slag  hearth,  and 
which  assume  the  granulated  form  from  being  made  to  flow,  when  in  a  melted  »tate, 
into  water. 

Cases  Nos.  22  and  23  contain  examples  of  the  crystals  of  selected  and  common 
lead  as  formed  in  the  process  of  separating  or  desilvering  the  ore :  patented  by  Mr.  11. 
L.  Pattinson,  and  first  brought  into  operation  at  Mr.  Beaumont's  smelt  mills. 

Cases  Nos.  24,  25,  and  26,  contain  specimens  of  the  fume  or  deposit  in  the  long  flues 
connected  with  the  smelt  mills;  that  in  No.  24  being  the  ordinary  fume  collected  in 
the  flue :  No.  25  the  same,  after  being  roasted  for  the  ore  hearth,  and  No.  26  the  same 
roasted  for  the  slag  hearth.  The  flues  or  chimneys  are  built  of  stone,  8  feet  by  6  feet 
inside,  and  upwards  of  8i  miles  long. 

Cases  Nos.  27,  28,  and  29.  Litharge  in  the  ordinary  round  state,  and  two  varie- 
ties of  linseed' litharge  which  have  been  passed  through  a  sieve. 

Case  No.  30.  Skimmings  from  the  surface  of  melted  lead,  showing  iridescent  hue8» 
which  are  frequently  of  great  intensity  and  beauty. 

A  brief  statement  of  the  quantity  of  coals  cousimied  per  month  in  a  few  of  the 
principal  mines  will  show  the  extent  to  which  steam  power  is  now  employed. 

Fowev  Consols,  1835  -             .             -             .             .  ioi,246 

Godolphin,  1839         -  .....  129,801 

Fowey  Consols,  1840  .....  203,699 

United  Mines,  1842    -  .....  84,862 

The  lead  mines  of  Cornwall  have  produced  of  the  argentiferous  sulphuret,  during 
five  years,  the  following  number  of  tons  of  ore  : — 


Collington           ... 

1845. 

1846. 

IWT. 

184S. 

1849. 

950 

1,138 

1,249 

957 

625 

Huel  Mary  Ann 

166 

192 

334 

873 

Coruubian           ... 

420 

K  and  W.  Haven 

16 

Huel  Trelawney 

280 

529 

883 

413 

1,296 

Camelford            .             .             . 

180 

E.  Huel  Rose      - 

7,883 

5,191 

6,424 

5,333 

4,758 

W.  Huel  Rose     - 

84 

30 

75 

Cargol      .... 

55 

306 

954 

964 

505 

Oxnams     -          -            -            . 

188 

47 

470 

269 

Huel  Rose           ... 

57 

375 

378 

399 

107 

Huel  Penrose      -             -             - 

116 

11 

Holmbush            -             -            - 

12 

60 

154 

102 

New  Quay 

73 

Porthleven         ... 

8 

82 

Pentire        -         - 

34 

Cubert         -        -             -            . 

136 

354 

68 

Leman         -        . 

30 

73 

Huel  Concord      -            -            . 

30 

30 

Huel  Trehane     - 

312 

459 

Herodscomb        ... 

37 

Herodsfoot          ... 

376 

721 

1,050 

Great  Callestock  Moors  - 

109 

Callestock            ... 

116 

179 

Treyorden           ... 

28 

Huel  Penhale      ... 

50 

Huel  Golden       - 

80 

Earthen  Consols  -             -             - 

45 

LEAD. 

Mines  were  worked  at  an  early  period  in  the  Isle  of  Man ;  but  the  neighborhood  of 
Laxey  first  attracted  attention  at  the  commencement  of  the  present  century,  In  1811 
only  three  hands  were  employed;  in  1848  there  were  at  least  800  in  the  mine.  The 
mine  is  situated  about  a  mile  and  a  half  from  the  sea,  up  the  Laxey  Valley;,  where  an 
adit  is  driven  400  fathoms  into  the  heart  of  the  mountain.  From  this  adit  the  shafi 
has  been  sunk  about  130  fathoms.  The  returns  of  lead  ore  for  the  last  five  years  hav* 
been  as  follows : — 


Teais. 

Lead  Ore. 

Lead. 

Tons. 

Tons. 

1845 

. 

827 

155 

1846 

•                 •                • 

220 

104 

1847 

.         -        - 

875 

247 

1848 

... 

695 

461 

1849 

... 

815 

546 

In  addition  to  this,  about  200  tons  of  the  sulphuret  of  zinc  are  annually  raised. 

The  Cardiganshire  mines  were  worked  at  a  very  early  period,  probably  by  the  Ro- 
mans. Henry  VIL  encouraged  mining  by  several  grants,  involving  privileges  to 
those  who  would  work  these  mines.  In  tlie  reign  of  Queen  Elizabeth  there  was  a 
grant  made  of  all  these  mines  to  Thomas  Thurland  and  Daniel  Houghsetter,  Germany 
who  worked  them  for  some  time.  They  eventually  passed  into  the  hands  of  Sir 
Hugh  Middleton,  who  realized  a  large  profit  by  working  them. 

The  present  value  of  the  Cardiganshire  mines  will  be  seen  by  the  following  list  of 
their  produce : — 


Mines. 

Lead  Ore 

Lead 

Keturns. 

Betums. 

Tons.     Cwta. 

Tons.    Cwts. 

Lisburne  Mines 

•                        «                        »                         • 

2,733       0 

1,804      0 

Cwm-y-stwyth 

. 

583       0 

333      0 

Esgair-hir 

.            -            - 

Cwm-sebon 

.            .            .            - 

55       0 

33      0 

Llanfair  Clydogan     - 

-            -            -            - 

206       0 

134      0 

Goginan 

-            -            -            - 

1,160      0 

766       0 

Gogerddan  Mines     - 

... 

131      0 

87       0 

Nanty-y-creiau 

•                        «                         «»                         • 

Pen-y-bout-pren 

m                            m                            m                            m 

12      0 

7      0 

Cefn-cwm-bruzno 

•                             •-                            •                             • 

10      0 

7      0 

Bwlch  Consols 

.                             •                             •                             . 

635      0 

425      0 

Nanteos 

.                             •                             •                             • 

177      0 

106      0 

Aberystwyth  (small  mines)  .             -             -             - 

81       0 

20      0 

Llanymaror   - 

«                             *                            «                             • 

Llanbadarn    - 

•                            •                            •                             - 

Bron-berllan  - 

.... 

Brynarian 

.... 

40      0 

28      0 

Cwm-erfin 

.... 

116      0 

78      0 

Daren 

*                             *                             •                              " 

29      0 

20      0 

Eisteddfodd   - 

-               -               -               - 

40    15 

14      0 

Llwyn   Malys 

.               -              .               - 

32      0 

21      0 

Bwlch-cwm-erfin     - 

.... 

18      0 

12      0 

Treatment  of  the  Ores  of  Lead. 
The  mechanical  operations  performed  upon  the  lead  ores  in  Great  Britain,  to  bring 
them  to  the  degree  of  purity  necessary  for  their  metallurgic  treatment,  maybe  divid3 
into  throe  classes,  whose  objects  are, — 

1.  The  sorting  and  cleansing  of  the  ores  ; 

2.  The  grinding; 

3.  Tlie  washing^  properly  so  called  ; 

The  apparatus  subservient  to  the  first  objects  are  sieves,  mnning  budles,  and  gratings. 
The  large  sieves  employed  in  Derbyshire  for  sorting  the  ore  at  the  mouth  of  the  mine 
into  coarse  and  fine  pieces,  is  a  wire  gauze  of  iron  ;  its  meshes  are  square,  and  an  inch 
long  in  each  side.  There  is  a  lighter  sieve  of  wire  gauze,  similar  to  the  preceding,  for 
washing  the  mud  from  the  ore,  by  agitating  the  fragments  in  a  tub  filled  with  water. 

/ 


ittm 


40 


LEAD. 


LEAD. 


The  running  huddle  serves  at  once  to  sort  and  clean«;p  th*.  oro     \*  ^      -  .     c       i 

surface  made  of  slabs  or  planks,  very  sl^hUy  inS  foLaS.  1  T^'^^^fA^'^^^^l 
and  on  the  sides  with  iinrJ^ht  \f.LJ^  L  ^"^""J^  mciinea  lorwards,  and  provided  behind 

powder  washed  out  of  the  ore  inches  m  diameter,  for  coUecting  the  metaUic 

The  apparatus  subservient  to  grinding  the  ore  are,— 

eitheV  wUh"a"r„VstVra'Ul°3S^S  ^^^^o^'^^'i^n,  JU>or,  is  provWed 
broad,  and  a  Uttle  mised  behM       o„  ,h  f  '     '"'?''  '']"?''  ""=''  ''  »  A^'  »™  «  feel 

walls  theoreto£Sedisied     On  h/r^<^^  ""'"P'^  '"'•o"''  ^-y  ^"^^l 

cast-iron  plate  is  laid  7  f^t  iJ^„  t-    ?     v   *'?"''  "."^  7""'  "  ^"^  >>"<•  stone  slab,  or 

ofTnirtH:i:,^Tz'Ti°'"XhTe^"''lr'  cylinders,,  x,.;??.  853,  and  of  two  pair, 
cylinders  of  each  of  the  thr^e  n,i  .         altogetlier  for  crushing  the  ore.    The  two 

means  cf  two  tSothtl  wheds  asTt  m.  «"  siT""''"'"^'^'"^""-.  '"''"^  ■''^«"™.  ^^ 
lucu  wneeis,  as  at  m,  fig.  854,  upon  the  shall  of  every  cylinder,  which 

853  g54 


41 


^ 


/a 


-"•^ 


retirlr^VrVp^nf  ^he  ^^^£^  b,  a  single  water-wheel,  of  which 
placed  in  the  prolongation  of  the  shift  of  Z!wi?r  ?"^,  ""^  ^^^  ^"^^^  cylindera  is 
toothed  wheer  geered  with  the  toXdwhpl.i'  "I"'"''  '^'."''  ^^'^^"^  ^  ^^^^^-^--^^ 
smooth  cylinders.     Above  the  fl^tid  p^  n!?       /u  ^''^^  "P^'^  ^^^  ^"^«  «^  t^«   «f  the 

«opt3r!heiroontentsi„eoY?Lr,rrtr:^l,r:-^^^^^^^^^ 


of  their  bottom.  Below  the  hopper  there  is  a  small  bucket  called  a  shoe,  into  which  the 
ore  is  shaken  down,  and  which  throws  it  without  ceasing  upon  the  cylinders,  in  conse- 
quence of  the  constant  jolts  given  it  by  a  crank-rod  i  {Jig.  854)  attached  to  it,  r.nd 
moved  by  the  teeth  of  the  wheel  m.  Tlie  shoe  is  so  regulated,  that  too  much  ore  can 
never  fiill  upon  the  cylinders,  and  obstruct  their  movement.  A  small  stream  of  water 
is  likewise  led  into  the  shoe,  which  spreads  over  the  cylinders,  and  prevents  them  from 
growing  hot  The  ore,  after  passing  between  the  fluted  rollers,  falls  upon  the  inclined 
planes  n,  n,  which  turn  it  over  to  one  or  other  of  the  pairs  of  smooth  rolls. 

These  are  the  essential  parts  of  this  machine ;  they  are  made  of  iron,  and  the  smooth 
ones  are  case-hardened,  or  chilled,  by  being  cast  in  iron  moulds.  The  gudgeons  of 
both  kinds  move  in  brass  bushes  fixed  upon  iron  supports  fe,  made  fast  by  bolts  to  the 
strong  wood-work  basis  of  the  whole  machine.  Each  of  the  horizontal  bars  has  an 
oblong  slot,  at  one  of  whose  ends  is  solidly  fixed  one  of  the  plummer-blocks  or  bearers 
of  one  of  the  cylinders  /,  and  in  the  rest  of  the  slot  the  plummer-block  of  the  other 
cylinder  g  slides;  a  construction  which  permits  the  two  cylinders  to  come  into  con- 
tact, or  to  recede  to  such  a  distance  from  each  other,  as  circumstances  may  require. 
The  moveable  cylinder  is  approximated  to  the  fixed  one  by  means  of  the  iron  levers  x  x, 
which  carry  at  their  ends  the  weights  p,  and  rest  upon  wedges  m,  which  may  be  slidden 
npon  the  inclined  plane  n.  These  wedges  then  press  the  iron  bar  o,  and  make  it  ap- 
proach the  moveable  cylinder  by  advancing  the  plummer  block  which  supports  its  axis. 
When  matters  are  so  arranged,  should  a  very  large  or  hard  piece  present  itself  to  one  of 
the  pairs  of  cylinders,  one  of  the  rollers  would  move  away,  and  let  the  piece  pass  without 
doing  injury  to  the  mechanism. 

Besides  the  three  pairs  of  cylinders  which  constitute  essentially  each  crushing  machines 
there  is  sometimes  a  fourth,  which  serves  to  crush  the  ore  when  not  in  large  fragments, 
for  example,  the  chats  and  cuttings  (the  moderately  rich  and  poorer  pieces),  produced 
by  the  first  sifting  with  the  brake  sieve,  to  be  presently  described.  The  cylinders  com- 
posing that  accessor}'  piece,  which,  on  account  of  their  ordinary  use,  are  called  chats-rollers, 
are  smooth,  and  similar  to  the  rollers  z  2,  and  z'  z'.  The  one  of  them  is  usually  placed 
upon  the  prolongation  of  the  shaft  of  the  water-wheel,  of  the  side  opposite  to  the  princi- 
pal machine  ;  and  the  other,  which  is  placed  alongside,  receives  its  motion  from  the  first, 
by  means  of  toothed  wheel-work. 

The  stamp  mill  is  employed  in  concurrence  with  the  crushing  cylinders.  It  ser^'es  par- 
ticularly to  pulverize  those  ores  whose  gangue  is  too  hard  to  yield  readily  to  the  rollers, 
and  also  those  which  being  already  pulverized  to  a  certain  degree,  require  to  be  ground 
still  more  finely.  The  stamps  employed  in  the  neighborhood  of  Alston  Moor  are  moved 
by  water  wheels.    They  are  similar  to  those  described  under  Tin. 

Proper  sifting  or  jigging  apparatus. — The  hand  sieve  made  of  iron  wire  meshes,  of 
various  sizes,  is  shaken  with  the  two  hands  in  a  tub  of  water,  the  ore  vat,  being  held 
sometimes  horizontally,  and  at  others  in  an  inclined  position.  This  sieve  is  now  in 
general  use  only  for  the  cuttings  that  have  passed  through  the  grating,  and  which  though 
not  poor  enough  to  require  finer  grinding,  are  too  poor  for  the  brake  sieve.  When  the 
workman  has  collected  a  sufficient  quantity  cf  these  smaller  pieces,  he  puts  them  in  his 
round  hand  sieve,  shakes  it  in  the  ore  vat  with  much  rapidity  and  a  dexterous  toss,  till 
he  has  separated  the  very  poor  portions  called  cuttings,  from  the  mingled  parts  called 
ckats^  as  well  as  from  the  pure  ore.  He  then  removes  the  first  two  qualities,  wilh  a 
shcf  t-iron  scraper  called  a  limp,  and  he  finds  beneath  them  a  certain  portion  of  ore  which 
he  reckons  to  be  pure. 

The  brake  sieve  is  rectangular,  as  well  as  the  cistern  in  which  it  is  agitated.  The 
meshes  are  made  of  strong  iron  wire,  tliree  eighths  of  an  inch  square.  This  sieve  is  sust- 
pended  at  the  extremity  of  a  forked  lever,  or  brake,  turning  upon  an  axis  by  means  of 
two  upright  arms  about  5  feet  long,  which  are  pierced  with  holes  for  connecting  them 
with  bolts  or  pins,  both  to  the  sieve-frame  and  to  the  ends  of  the  two  branches  of  the 
lever.  These  two  arms  are  made  of  wrought  iron,  but  the  lever  is  made  of  wood ;  as  it 
receives  the  jolt. '  A  child  placed  near  its  end,  by  the  action  of  leaping,  jerks  it  smartly 
Up  and  down,  so  as  to  shake  effectually  the  sieve  suspended  at  the  other  extremity. 
Each  jolt  not  only  makes  the  fine  parts  pass  through  the  meshes,  but  changes  the  rela- 
tive position  of  those  which  remain  on  the  wires,  bringing  the  purer  and  heavier  pieces 
eventually  to  the  bottom.  The  mingled  fragments  of  galena,  and  the  stony  substances 
called  chats  lie  above  them ;  while  the  poor  and  light  pieces  called  cuttings,  are  at  top. 
These  are  first  scraped  off  by  the  limp,  next  the  mixed  lumps,  or  chats,  and  lastly  the  pure 
ore,  which  is  carried  to  the  bing  heap.  The  cuttings  are  handed  to  a  particular  class  of 
workmen,  who  by  a  new  sifting,  divide  them  into  mere  stones,  or  second  cuttings,  and  into 
mixed  ore  analogous  to  chats. 

The  poor  ore,  called  chats,  is  carried  to  a  crushing  machine,  where  it  is  bruised 
between  two  cylinders  appropriated  to  this  purjwse  under  the  name  of  chats  rollers;  after 
which  it  is  sifted  afresh.     During  the  sifting  many  parcels  of  small  ore  and  stony  sub 

/ 


43 


LEAD. 


LEAD. 


48 


II 


stances  pass  through  the  sieve,  and  accumulate  at  the  bottom  of  the  cistern.  When  it 
is  two  thirds  filled,  water  is  run  slowly  over  it,  and  the  sediment  called  smitham  is  taken 
out,  and  piled  up  in  heaps.  More  being  put  into  the  tub,  a  child  lifts  up  the  smitham^ 
and  lays  it  on  the  sieve,  which  retains  still  on  its  meshes  the  layer  of  fine  ore.  The  sifter 
now  agitates  in  the  water  nearly  as  at  first,  from  time  to  time  removing  with  the  limp 
the  lighter  matters  as  they  come  to  the  surface ;  which  being  fit  for  washing  only  in 
boxes,  are  called  buddler^s  offaly  and  are  thrown  into  the  budlk  hole. 

Mr.  Petherick,  the  manager  of  Lanescot  and  the  Fowey  Consol  mines,  has  contrived 
an  ingenious  jigging  machine,  in  which  a  series  of  8  sieves  are  fixed  in  a  stationary  cir- 
cular frame,  connected  with  a  plunger  or  piston  working  in  a  hollow  cylinder,  whereby 
a  body  of  water  is  alternately  forced  up  through  the  crushed  ore  in  the  sieves,  and  then 
left  to  descend.  In  this  way  of  operating,  the  indiscriminate  or  premature  passage  of  the 
finer  pulverulent  matter  through  the  meshes  is  avoided,  because  a  regulated  stream  of 
water  is  made  to  traverse  the  particles  up  and  down.  This  mode  has  proved  profitable  in 
washing  the  copper  ores  of  the  above  mentioned  copper  mines. 

Proper  washing  apparatus. — For  washing  the  ore  after  sifting  it,  the  running  buddle 
already  described  is  employed,  along  with  several  chests  or  buddies  of  other  kinds. 

1.  The  trunk  huddle  is  a  species  of  German  chest  (see  Mf.tallurgy  and  Tin)  com- 
posed of  two  parts ;  of  a  cistern  or  box  into  which  a  stream  of  water  flows,  and  of  a  large 
tank  with  a  smooth  level  bottom.  The  ore  to  be  trunkcd  being  placed  in  the  box,  the 
workman  furnished  with  a  shovel  bent  up  at  its  sides,  agitates  it,  and  removes  from  time 
to  time  the  coarser  portions ;  while  the  smaller  are  swept  off  by  the  water  and  deposited 
upon  the  level  area. 

2.  The  stirring  buddle,  or  chest  for  freeing  the  schlamms  or  slimy  stuff  from  clay,  is 
analogous  to  the  German  chests,  and  consists  of  two  parts;  namely,  1.  a  trough  which 
receives  a  stream  of  water  through  a  plug  hole,  which  is  tempered  at  pleasure,  to  admit  a 
greater  or  less  current ;  2.  a  settling  tank  with  a  horizontal  bottom.  The  metallic  slime 
being  first  floated  in  the  water  of  the  trough,  then  flows  out  and  is  deposited  in  the  tank  j 
the  purest  parts  falling  first  near  the  beginning  of  the  run. 

3.  The  nicking  buddle  is  analogous  to  the  tables  called  dormantes  or  jumelles  by  the 
French  miners.  See  Metallurgy.  They  have  at  their  upper  end  a  cross  canal  or 
spout,  equal  in  length  to  the  breadth  of  the  table,  with  a  plug  hole  in  its  middle  for 
admitting  the  water.  Alongside  of  this  channel  there  is  a  slightly  inclined  plank,  called 
nicking  board,  corresponding  to  the  head  of  the  iwin  table,  and  there  is  a  nearly  level 
plane  below.  The  operation  consists  in  spreading  a  thin  layer  of  the  slime  upon  the 
nicking  board,  and  in  running  over  its  surface  a  slender  sheet  of  water,  which  in  its  pro- 
gress is  subdivided  into  rills,  which  gradually  carry  off  the  muddy  matters,  and  strew 
them  over  the  lower  flat  surface  of  the  tank,  in  the  order  of  their  density. 

4.  The  dolly  tub  or  rinsing  bucket,  Jig.  855,  has  an  upright  shaft  which 
bears  the  vane  or  dolly  a  b,  turned  by  the  winch  handle.  This  apparatus 
serves  to  bring  into  a  state  of  suspension  in  water,  the  fine  ore,  already 
nearly  pure ;  the  separation  of  the  metallic  particles  from  the  earthy  ones 
by  repose,  being  promoted  by  the  sides  of  the  tub  being  struck  frequently 
during  the  subsidence. 

5.  Slime  pits. — In  the  several  operations  of  cleansing  ores  from  mud, 
ia  grinding,  and  washing,  where  a  stream  of  water  is  used,  it  is  impossible  to  prevent 
eome  of  the  finely  attenuated  portions  of  the  galena  called  sludge,  floating  in  tfte  watei; 
from  being  carried  ofl'  with  it.  Shm£  pits  or  labyrinths,  called  buddle  holes  in  Derbyshire, 
are  employed  to  collect  that  matter,  by  receiving  the  water  to  settle,  at  a  little  distance 
from  the  place  of  agitation. 

These  basins  or  reservoirs  are  about  20  feet  in  diameter,  and  from  24  to  40  inches 
deep.  Here  the  suspended  ore  is  deposited,  and  nothing  but  clear  water  is  allowed  to 
escape. 

The  workmen  employed  in  the  mechanical  preparation  of  the  ores,  are  paid,  in  Cum 
berland,  by  the  piece,  and  not  by  day's  wages.  A  certain  quantity  of  crude  ore  is  deliv- 
ered to  them,  and  their  work  is  valued  by  the  bing,  a  measure  containing  14  cwts.  of  ore 
ready  for  smelting.  The  price  varies  according  to  the  richness  of  the  ore.  Certain  quali- 
ties are  washed  at  the  rate  of  two  and  sixpence,  or  tliree  shillings  the  bing;  while  others 
are  worth  at  least  ten  shillings.  The  richness  of  the  ore  varies  from  2  to  20  bings  of 
galena  per  shift  of  ore ;  the  shift  corresponding  to  8  wagon  loads. 

1.  The  cleansing  and  sorting  of  the  ores  are  well  performed  in  Cumberland.  These 
operations  seem  however  to  be  inferior  to  the  cleansing  on  the  grid  steps,  grilles  a  gradin^ 
of  Saxony  (See  Mktallurgy),  an  apparatus  which  in  cleaning  the  ores,  has  the  advan- 
tage of  grouping  them  in  lots  of  different  qualities  and  dimensions. 

2.  The  breaking  or  bruising  by  means  of  the  crushing  machine,  is  much  more  expedi- 
tious than  the  Derbyshire  process  by  buckers ;  for  the  machine  introduces  not  only  great 
economy  into  the  breaking  operation,  but  it  likewise  diminishes  considerably  the  loss  of 
galena ;  for  stamped  ores  may  be  often  subjected  to  the  action  of  the  cylinders  without 


^:;g:;;.:-' 


waste  while  a  portion  of  them  would  have  been  lost  with  the  water  that  runs  from  the 
stamp' mill.  The  use  of  these  rollers  may  therefore  be  considered  as  one  of  the  happiest 
innovations  hitherto  made  in  the  mechanical  preparation  of  ores. 

3.  The  hake  sieves  appear  to  be  preferable  to  the  hand  ones. 

4.  The  system  of  washing  used  in  Cumberland  differs  essentially  from  that  of  Brit- 
tany. The  slime  pits  are  constructed  with  nmch  less  care  than  in  France  and  Germany. 
They  never  present,  as  in  these  countries,  those  long  windings  backwards  and  forwoids, 
whence  they  have  been  called  labyrinths ;  probably  because  the  last  deposites,  which  are 
washed  with  profit  in  France  and  Germany,  could  not  be  so  in  Cumberland.  There  is 
reason  to  believe,  however,  that  the  introduction  of  biuke  tables  {tables  a  seccusscs,  see 
Metallurgy)  would  enable  deposites  to  be  saved,  which  at  present  run  to  waste  in 

England.  j   .     t     • 

5.  From  what  we  have  now  said  about  the  system  of  washing,  and  the  basins  of  de- 
posite  or  settling  cisterns,  it  may  be  inferred  that  the  operation  followed  in  Cumberland  is 
more  expeditious  than  that  used  in  Brittany,  but  it  furnishes  less  pure  ores,  and  occasions 
more  considerable  waste  ;  a  fact  sufficiently  obvious,  since  the  refuse  stuff  at  Poullaouen  is 
often  resumed,  and  profitably  subjected  to  a  new  preparation.  We  cannot  however  ven- 
ture to  blame  this  method,  because  in  England,  fuel  being  cheap,  and  labor  dear,  there 
may  possibly  be  more  advantage  in  smelting  an  ore  somewhat  impure,  and  in  losing  a  little 
galena,  than  in  multiplying  the  number  of  washing  processes. 

6.  Lastly,  the  dolly  tub  ought  to  be  adopted  in  all  the  establishments  where  the  galena 
is  mixed  with  much  blende  (sulphuret  of  zinc) :  for  schlich  (metallic  slime)  which  appears 
very  clean  to  the  eye,  gives  off  a  considerable  quantity  of  blende  by  means  of  the  dolly 
tub.  While  the  vane  is  rapidly  whirled,  the  sludge  is  gradually  let  down  into  the  revolv- 
ing water,  till  the  quantity  is  sufficiently  great.  Whenever  the  ore  is  thoroughly  dissem- 
inated in  the  liquid,  the  dolly  is  withdrawn.  The  workmen  then  strike  on  the  sides  of 
the  tub  for  a  considerable  time,  with  mallets  or  wooden  billets,  to  make  the  slime  fall  fast 
to  the  bottom.  The  lighter  portions,  consisting  almost  entirely  of  refuse  matter,  fall  only 
after  the  knocking  has  ceased :  the  water  is  now  run  away ;  then  the  very  poor  slime  upon 
the  top  of  the  deposite  is  skimmed  off,  while  the  pure  ore  found  at  the  bottom  of  the  tub 
is  lifted  out,  and  laid  on  the  bingstead.  In  this  way  the  blende,  which  always  accompa- 
nies galena  in  a  greater  or  smaller  quantity,  is  well  separated. 

Smelling  of  lead  ores. — The  lead  ores  of  Derbyshire  and  the  north  of  England  were 
anciently  smelted  in  very  rude  furnaces,  or  boles,  urged  by  the  natural  force  of  the  wind, 
and  were  therefore  placed  on  the  summits  or  western  slopes  of  the  highest  hills.  More 
recently  these  furnaces  were  replaced  by  blast  hearths,  resembling  smiths'  forges,  bat 
larger,  and  were  blown  by  strong  bellows,  moved  by  men  or  water-wheels.  The 
principal  operation  of  smelting  is  at  present  always  executed  in  Derbyshire  in  rerer- 
beratory  furnaces,  and  at  .Alston  Moor  in  furnaces  similar  to  those  known  in  France  by 
the  name  of  Scotch  furnaces.  Before  entering  into  the  detail  of  the  founding  processes, 
we  shall  give  a  description  of  the  furnaces  essential  for  both  the  smelting  and  accessory 

operations.  ,     .     ,  .  •     t^    .     t.-     r 

1.  The  reverberatory  furnace  called  cupola,  now  exclusively  used  in  Derbyshu-e  loi 

the  smelting  of  lead  ores,  was  imported  thither  from  Wales,  about  the  year  1747,  by  a 

company  of  Quakers.     The  first  establishment  in  this  country  was  built  at  Kalstedgp.  w 

the  disti  ict  of  Ashover. 

In  the  woiks  where  the  construction  of  these  furnaces  is  most  improved,  they  are 
interiorly  8  feet  long  by  6  wide  in  the  middle,  and  two  feet  high  at  the  centre.  The 
fire,  placed  at  one  of  the  extremities,  is  separated  from  the  body  of  the  furnace  by  a  body 
of  masonry,  called  the  fire-bridge,  which  is  two  feet  thick,  leaving  oniy  from  14  to  18 
inches  between  its  upper  surface  and  the  vault.  From  this,  the  highest  point,  the  vault 
gradually  sinks  towards  the  further  end,  where  it  stands  only  6  inches  above  the  sole. 
At  this  extremity  of  the  furnace,  there  are  two  openings  separated  by  a  triangular  prisra 
of  fire-stone,  which  lead  to  a  flue,  a  foot  and  a  half  wide,  and  10  feet  long,  which  is 
recurved  towards  the  top,  and  runs  into  an  upright  chimney  55  feet  high.  The  above 
flue  is  covered  with  stone  slabs,  carefully  jointed  with  fire-clay,  which  may  be  removed 
when  the  deposite  formed  under  them  (which  is  apt  to  melt)  requires  to  be  cleaned  out. 
One  of  the  sides  of  the  furnace  is  called  the  laborers'  side.  It  has  a  door  for  throwing 
coal  upon  the  fire-grate,  besides  three  small  apertures  each  about  6  inches  square. 
These  are  closed  with  moveable  plates  of  cast  iron,  which  are  taken  off  when  the  working 
requires  a  freer  circulation  of  air,  or  for  the  stirring  up  of  the  materials  upon  the  hearth. 
On  the  opposite  side,  called  the  working  side,  there  are  five  apertures ;  namely,  three  equal 
and  opposite  to  those  just  described,  shutting  in  like  manner  with  cast  iron  plates,  and 
beneath  them  two  other  openings,  one  of  which  is  for  running  out  the  lead,  and  another 
for  the  scoriae.  The  ash  pit  is  also  on  this  side,  covered  with  a  little  water,  and  so  dis- 
posed as  that  the  grate-bars  may  be  easily  cleared  from  the  cinder  slag. 

The  hearth  of  the  furnace  is  composed  of  the  reverberatory  furnace  slags,  lo  which  a 


44 


LEAD. 


proper  shape  has  been  given  by  beating  them  with  a  strong  iron  rake,  before  their 
entire  solidification.  On  the  laborers'  side,  this  hearth  rises  nearly  to  the  surface  of 
the  three  openings,  and  falls  towards  the  working  side,  so  as  to  be  18  inches  below  the 
middle  aperture.  In  this  point,  the  lowest  of  the  furnace,  there  is  a  tap-hole,  through 
which  the  lead  is  run  off  into  a  large  iron  boiler  (lea-pan),  placed  in  a  recess  left  out- 
side in  the  masonry.  From  that  lowest  point,  the  sole  gradually  rises  in  all  directions, 
forming  thus  an  inside  basin,  into  which  the  lead  runs  down  as  it  is  smelted.  At  the  usual 
level  of  the  metal  bath,  there  is  on  the  working  side,  at  the  end  furthest  from  the  fire,  an 
aperture  for  letting  off  the  slag 

In  the  middle  of  the  arched  roof  there  is  a  small  aperture,  called  the  crovm-hole,  which 
is  covered  up  during  the  working  with  a  thick  cast  iron  plate.  Above  this  aperture  a 
large  wooden  or  iron  hopper  stands,  leading  beneath  into  an  iron  cylinder,  through 
which  the  contents  of  the  hopper  may  fall  into  the  furnace  when  a  tiap  or  valve  is 
opened. 

2.  The  roasting  furnace.  — This  was  introduced  about  30  years  ago,  in  the  neigh- 
borhood of  Alston  Moor,  for  roasting  the  ore  intended  to  pass  through  the  Scotch  furnace, 
a  process  which  greatly  facilitates  that  operation.  Since  its  first  establishment  it  has  suc- 
cessively received  considerable  improvements. 

J^lgs.  856,  857,  858,  represent  the  cupola  furnace  at  the  Marquess  of  Westminster's 
lead  smelting  works,  two  miles  from  Holywell.  Tlie  hearth  is  hollowed  out  below  the 
middle  door  of  the  furnace ;  it  slopes  from  the  back  and  ends  towards  this  basin.  The 
distance  from  the  lowest  point  of  this  concavity  up  to  the  sill  of  the  door,  is  usually  24 
inches,  but  it  is  sometimes  a  little  less,  according  to  the  quality  of  the  ores  to  be  smelted. 
This  furnace  has  no  hole  for  running  off  the  slag,  above  the  level  of  the  top  hole  for  the 
lead  t,  like  the  smelting  furnace  of  Lea,  near  Matlock.  A  single  chimney  stalk  serves 
for  all  the  establishments ;  and  receives  all  the  fluos  of  the  various  roasting  and  reducing 
furnaces.  Fig.  858  gives  an  idea  of  the  distribution  of  these  flues,  a  a  a,  <fec.  are  the 
furnaces,  b,  the  flues,  18  inches  square;  these  lead  from  each  furnace  to  the  principal 
conduit  c,  which  is  5  feet  deep  by  2 J  wide  ;  d  ia  6  feet  deep  by  3  wide;  <?  is  a  round 
chamber  15  feet  in  diameter;  /is  a  conduit  7  feet  high  by  5  wide;  g  another,  6  feet 
high  by  3  wide.  The  chimney  at  k  has  a  diameter  at  bottom  of  30  feet,  at  top  of  12 
feet  including  the  thickness  of  its  sides,  forming  a  truncated  cone  100  feet  high  ;  whose 
base  stands  upon  a  hill  a  little  way  from  the  fur  naces,  and  62  feet  above  their  leveL 

a,  Jigs.  856,  857,  is  the  grate ;  b,  the  door  of  the  fire-place  ;  c,  the  fire-bridge ;  d  ♦he 

856 


857 


858 


M^     ^^     ^     jm      j^ 

H  H  R  R  P 


K-^H^ 


arched  roof;  e  the  hearth  ;  ///,  <fec.,  the  working  doors ;  g  g,  flues  running  into  one 
conduit,  which  leads  to  the  subterranean  condensing-chamber  e,  and  thence  to  the 
general  chimney;  h,  a.  hopper-shaped  opening  in  the  top  of  the  furnace,  for  supplying 
it  with  materiids.  "^     ° 

This  magnificent  structure  is  not  destined  solely  for  the  reduction  of  the  ores,  but  for 
dissipating  all  the  vapors  which  might  prove  noxious  to  the  health  of  the  workpeople 
and  to  vegetation. 

The  ores  smelted  at  Holywell  are  very  refractory  galena8,mixed  with  blende,calamine, 


LEAD. 


45 


P3Tites,  carbonate  of  lime,  &c.,  but  without  any  fluate  of  lime.  They  serve  mutually  as 
fiuxes  to  one  another.  The  coal  is  of  inferior  quality.  The  sole  of  each  furnace  is 
formed  of  slags  obtained  in  the  smelting,  and  they  are  all  of  one  kind.  In  constructing 
it,  7  or  8  tons  of  these  slags  are  first  of  all  thrown  upon  the  brick  area  of  the  hearth ;  are 
made  to  melt  by  a  brisk  fire,  and  in  their  stiflening  state,  as  they  cool,  they  permit  the 
bottom  to  be  sloped  and  hollowed  into  the  desired  shape.  Four  workmen,  two  at  each 
side  of  the  furnace,  perform  this  task. 

The  ordinary  charge  of  ore  for  one  smelting  operation  is  20  cwts.,  and  it  is  introduced 
through  the  hopper ;  see  Copper,, /fg.  375.  An  assistant  placed  at  the  back  doors  spreads 
it  eciually  over  the  whole  hearth  with  a  rake ;  the  furnace  being  meanwhile  heated  only 
with  the  declining  fire  of  the  preceding  operation.  No  regular  fire  is  made  during  the  first 
two  hours,  but  a  gentle  heat  merely  is  kept  up  by  throwing  one  or  two  shovelfuls  of  small 
coal  upon  the  grate  from  time  to  time.  All  the  doors  are  closed,  and  the  register-plate  of 
the  chimney  is  lowered. 

The  outer  basin  in  front  of  the  furnace  is  at  this  time  filled  with  the  lead  derived  from 
a  former  process,  the  metal  being  covered  with  slags.  A  rectangular  slit  above  the  tap 
hole  is  left  open,  and  remains  so  during  the  whole  time  of  the  operation,  unless  the  leai' 
should  rise  in  the  interior  basin  above  the  level  of  that  orifice ;  in  which  case  a  little  mound 
must  be  raised  before  it. 

The  two  doors  in  front  furthest  from  the  fire  being  soon  opened,  the  head-smelter 
throws  in  through  them,  upon  the  sole  of  the  furnace,  the  slags  swimming  upon  the  bath 
of  lead,  and  a  little  while  afterwards  he  opens  the  tap-hole,  and  runs  off  the  metallic 
lead  reduced  from  these  slags.  At  the  same  time  his  assistant  turns  over  the  ore  with 
his  paddle,  through  the  back  doors.  These  being  again  closed,  while  the  above  two  front 
doors  are  open,  the  smelter  throws  a  shovelful  of  small  coal  or  coke  cinder  upon  the  lead 
bath,  and  works  the  whole  together,  turning  over  the  ore  with  the  paddle  or  iron  oar. 
About  three  quarters  of  an  hour  after  the  commencement  of  the  operation,  he  throws 
back  upon  the  sole  of  the  hearth  the  fresh  slags  which  then  float  upon  the  bath  of  the 
outer  basin,  and  which  are  mbced  with  coaly  matter.  He  next  turns  over  these  slags,  as 
well  as  the  ore  with  the  paddle,  and  shuts  all  the  doors.  At  this  time  the  smelter  runs  off 
the  lead  into  the  pig-moulds. 

The  assistant  now  turns  over  the  ore  once  more  through  the  back  doors.  A  little 
more  than  an  hour  after  the  operation  began,  a  quantity  of  lead  proceeding  from  the 
slag  last  remelted,  is  run  off  by  the  tap ;  being  usually  in  such  quantity  as  to  fill  one 
half  of  the  outer  basin.  Both  the  workmen  then  turn  over  the  ore  with  the  paddles,  at 
the  several  doors  of  the  furnace.  Its  interior  is  at  this  time  of  a  dull  red  heat ;  the 
roasting  being  carried  on  rather  by  the  combustion  of  the  sulphurous  ingredients,  than 
by  the  action  of  the  small  quantity  of  coal  in  the  grate.  The  smelter,  after  shutting 
the  front  doors,  with  the  exception  of  that  next  the  fire-bridge,  lifts  off  the  fresh  slags 
lying  upon  the  surface  of  the  outside  bath,  drains  them,  and  throws  them  back  into  the 
furnace. 

An  hour  and  a  half  after  the  commencement,  the  lead  begins  to  ooze  out  in  small 
quantities  from  the  ore  ;  but  little  should  be  suffered  to  flow  before  two  hours  have  ex- 
pired. About  this  time  the  two  workmen  open  all  the  doors,  and  turn  over  the  ore, 
each  at  his  own  side  of  the  turnace.  An  hour  and  three  quarters  after  the  beginning, 
there  are  few  vapors  in  the  furnace,  its  temperature  being  very  moderate.  No  more 
lead  is  then  seen  to  flow  upon  the  sloping  hearth.  A  little  coal  being  thrown  into  the 
grate  to  raise  the  heat  slightly,  the  workmen  turn  over  the  ore,  and  then  close  all  the 
doors. 

At  the  end  of  two  hours,  the  first  fire  or  roasting  bemg  completed,  and  the  doors 
shut,  the  register  is  to  be  lifted  a  little,  and  coal  thrown  upon  the  grate  to  give  the 
iecond  fire,  which  lasts  during  25  minutes.  When  the  doors  are  now  opened,  the  inside 
of  the  furnace  is  of  a  pretty  vivid  red,  and  the  lead  flows  down  from  every  side  towards 
the  inner  basin.  The  smelter  with  his  rake  or  paddle  pushes  the  slags  upon  that  basin 
bftck  towards  the  upper  part  of  the  sole,  and  his  assistant  spreads  them  uniformly  over 
the  surface  through  the  back  doors.  The  smelter  next  throws  in  by  his  middle  door,  a 
few  shovelfuls  of  quicklime  upon  the  lead  bath.  The  assistant  meanwhile,  for  a  quarter 
of  an  hour,  works  the  ore  and  the  slags  together  through  the  three  back  doors,  and  then 
spreads  them  out,  while  the  smelter  pushes  the  slags  from  the  surface  of  the  inner  basin 
back  to  the  upper  parts  of  the  sole.  The  doors  being  now  left  open  for  a  little,  while 
the  interior  remains  in  repose,  the  metallic  lead,  which  had  been  pushed  back  with  the 
slags,  flows  down  into  the  basin.  This  occasional  cooling  of  the  furnace  is  thought  to  be 
necessary  for  the  better  separation  of  the  products,  especially  of  the  slags,  from  the  lead 
bath. 

In  a  short  time  the  workmen  resume  their  rakes,  and  turn  over  the  slags  along  with 
the  ore.  Three  hours  after  the  commencement,  a  little  more  fuel  is  put  into  the  grate, 
merely  to  keep  up  a  moderate  heat  of  the  furnace  during  the  paddling.    After  three 


4e 


LEAD. 


\  ! 


hours  and  ten  minutes,  the  grate  being  charged  with  fuel  for  the  third  fire,  the  register 
is  completely  opened,  the  doors  are  all  shut,  and  the  furnace  is  left  in  this  state  for  three 
quarters  of  an  hour.  In  nearly  four  hours  from  the  commencement,  all  the  doors  being 
opened,  the  assistant  levels  the  surfaces  with  his  rake,  in  order  to  favor  the  descent  of 
any  drops  of  lead ;  and  then  spreads  the  slags,  which  are  pushed  back  towards  him  by 
the  smelter.  The  latter  now  throws  in  a  fresh  quantity  of  lime,  with  the  view  not 
merely  of  covering  the  lead  bath  and  preventing  its  oxydizement,  but  of  rendering  the  slags 

less  fluid.  r  r    t 

Ten  minutes  after  the  third  fire  is  completed,  the  smelter  puts  a  new  charge  of  luel 
in  the  grate,  and  shuts  the  doors  of  the  furnace  to  give  it  the  fourth  fire.  In  four  hours 
and  fortv  minutes  from  the  commencement,  this  fire  being  finished,  the  doors  are 
opened,  the  smelter  pierces  the  tap  hole  to  discharge  the  lead  into  the  outer  basin,  and 
throws  some  quicklime  upon  the  slajjs  in  the  inner  basin.  He  then  pushes  the  slags 
thus  dried  up  towards  the  upper  part  of  the  hearth,  and  his  assistant  rakes  them  out  by  the 

back  doors. 

The  whole  operation  of  a  smelting  shift  takes  about  four  hours  and  a  half,  or  at  mosi 
five  hours,  in  which  four  periods  may  be  distinguished. 

1.  The  first  fire  for  roasting  the  ores,  requires  very  moderate  firing  and  lasts  two 

hours.  , 

2.  The  second  fire,  or  the  smelting,  requires  a  higher  heat,  with  shut  doors  ;  at  the  end 
the  slags  are  dried  up  with  lime,  and  the  furnace  is  also  allowed  to  cool  a  little. 

3  4.  The  last  two  periods,  or  the  third  and  fourth  fires,  are  likewise  two  smeltings  or 
foundings,  and  differ  from  the  first  only  in  requiring  a  higher  temperature.  The  heat 
is  greatest  in  the  last.  The  form  and  dimensions  of  the  furnace  are  calculated  to  cause 
a  uniform  distribution  of  heat  over  the  whole  surface  of  the  hearth.  Sometimes  billets 
of  green  wood  are  plunged  into  the  metallic  lead  of  the  outer  basin,  causing  an  ebullition 
which  favors  the  separationof  the  slags,  and  consequently  the  production  of  a  purer  lead; 
but  no  more  metallic  metal  is  obtained. 

Ten  cwts.  of  coal  are  consumed  at  Holywell  in  smelting  one  ton  of  the  lead-ore  schltch 
or  sludge  ;  but  at  Grassington,  near  Skipton  in  Yorkshire,  with  a  similar  furnace  worked 
with  a 'slower  heat,  the  operation  taking  from  seven  hours  to  seven  hours  and  a  half, 
instead  of  five,  onlv  7|  cwts.  of  coal  are  consumed.  But  here  the  ores  are  less  refractory, 
have  the  benefit  of  fluor  spar  as  a  flux,  and  are  more  exhausted  of  their  metal,  being  smelt- 
ed upon  a  less  sloping  hearth.  ,  •     />, 

Theory  of  the  above  operation.  —  At  Holj-well,  Grassington,  and  m  CurnwaiJ,  the 
result  of  the  first  graduated  roasting  heat,  is  a  mixture  of  undecomposed  sulphuret  of 
lead,  with  sulphate  and  oxyde  of  lead,  in  proportions  which  varj'  with  the  degree  of  care 
bestowed  upon  the  process.  After  the  roasting,  the  heat  is  raised  to  convert  the  sludge 
into  a  pasty  mass  ;  in  which  the  oxyde  and  sulphate  react  upon  the  sulphuret,  so  as  to 
produce  a  sub-sulphuret,  which  parts  with  the  metal  by  liquation.  The  cooling  of  the 
furnace  facilitates  the  liquation  every  time  that  the  sub-sulphuret  is  formed,  and  the  ore 
has  passed  by  increase  of  temperature  from  the  pasty  into  the  liquid  state.  Cooling 
brings  back  the  sludge  to  the  pasty  condition,  and  is  therefore  necessary  for  the  due 
separation  of  the  different  bodies.  The  drying  up  of  the  thin  slags  by  lime  is  intended 
tx)  liberate  the  oxyde  of  lead,  and  allow  it  to  react  upon  any  sulphuret  which  may  have 
resisted  roasting  or  decomposition.  It  is  also  useful  as  a  thicke^tcr,  in  a  mechanical  point 
of  view.  The  iron  of  the  tools,  which  wear  away  very  fast,  is  also  serviceable  in  re- 
dncin?  the  sulphuret  of  lead.  The  small  coal  added  along  with  the  iime  at  Grassington, 
and  also  sometimes  at  Holywell,  aids  in  reducing  the  oxyde  of  lead,  and  in  transforming 
the  sulphate  into  sulphuret. 

3.  The  smelting  furnace  or  ore  hearth.— This  furnace,  called  by  the  French  ecossaiSy  is 
from  22  to  24  inches  in  height  and  1  foot  by  1|  in  area  inside  ;  but  its  horizontal  section, 
always  rectangular,  varies  much  in  its  dimensions  at  different  levels,  as  shown  in 
fig.  859. 


LEAD. 


47 


The  hearth  and  the  sides  are  of  cast  iron ;  the  sole-plate  a  b  is  also  of  cast  iron,  2|  inches 
thick,  having  on  its  back  and  two  sides  an  upright  ledge,  a  c,  2|  inches  thick  and  4  J 
high.  In  front  of  the  hearth  there  is  another  cast  iron  plate  m  n,  called  the  uork 
atone,  surrounded  on  every  side  excepting  towards  the  sole  of  the  furnace,  by  a  le<lge 
one  inch  in  thickness  and  height.  The  plate  slopes  from  behind  forwards,  ami  its  pos- 
terior ledge,  which  is  about  A\  inches  above  the  surface  of  the  hearth,  is  separated  from 
it  by  a  void  space  q,  which  is  filled  with  a  mixture  of  bone  ash  and  jjalena,  both  in  fine 
powder,  moistened  and  pressed  down  together.  The  melted  lead  cannot  penetrate  into 
this  body,  but  after  filling  the  basin  at  the  bottom  of  the  furnace,  flows  naturally  out 
by  the  gutter  (nearly  an  inch  deep)  through  a  groove  in  the  work-stone;  and  then 
passes  into  a  caldron  of  reception  p,  styled  the  melting-pot,  placed  below  the  front  edge 
of  the  work-stone. 

The  posterior  ledge  of  the  sole  is  surmounted  by  a  piece  of  cast  iron  c  r,  called  the 
back-stone,  28  inches  long,  and  6^  high;  on  which  the  tuyere  or  blast-pipe  is  placed.  II 
supports  another  piece  of  cast  iron  e,  called  pipe-stone,  scooped  out  at  its  under  part,  in 
the  middle  of  its  length,  for  the  passage  of  the  tuyh-e.  This  piece  advances  2  inches  into 
the  interior  of  the  furnace,  the  back  wall  of  which  is  finally  crowned  by  another  piece  of 
cast  iron  e  h,  called  also  back-slone. 

On  the  ledges  of  the  two  sides  of  the  sole,  are  placed  two  pieces  of  cast  iron,  called 
bearers,  each  of  which  is  5  inches  in  breadth  and  height,  and  26  inches  long.  They 
advance  an  inch  or  two  above  the  posterior  and  highest  edge  of  the  work-stone,  and  con- 
tribute effectually  to  fix  it  solidly  in  its  place.  These  bearers  support,  through  the  in- 
tervention of  several  ranges  of  fire-bricks,  a  piece  of  cast  iron  called  a  fore-stone,  which 
has  the  same  dimensions  as  the  piece  called  the  back-stone,  on  which  the  base  of  the 
blowinsf-machine  rests.  This  piece  is  in  contact,  at  each  of  its  extremities,  with  another 
mass  of  cast  iron,  6  inches  cube,  called  the  key-stone,  supported  on  the  masonry.  Lastly, 
the  void  spaces  left  between  the  two  keystones  and  the  back  part  of  the  furnace  are  filled 
up  with  two  masses  of  cast  iron  exactly  like  the  Jiey-stones. 

The  front  of  the  furnace  is  open  for  about  12  inches  from  the  lower  part  of  the  front 
cross-piece  called  fore-stone,  up  to  the  superior  part  of  the  work-stone.  It  is  through  this 
opening  that  the  smelter  operates. 

The  gaseous  products  of  the  combustion,  on  escapine  from  this  ore-hearth,  arc  fre- 
quently made  to  pass  through  a  lonsr  flue,  sloped  very  slis^htly  upwards,  in  which  they 
depositeall  the  particles  of  ore  that  they  may  have  swept  along;  these  flues,  whose  length 
18  sometimes  more  than  100  yards,  are  usuallv  5  feet  high  and  3  feet  wide  in  the  inside, 
and  always  terminate  m  a  chimney  stalk.  The  matters  de)  osited  near  the  commence- 
ment of  the  flue  require  to  be  wasbed ;  but  not  the  other  dusty  dc|)osi{s.  The  whole 
may  then  be  earned  back  to  the  roasting  furnace,  to  be  calcined  and  re-agWutinated  or 
introduced  without  any  preparation  into  the  s^ay  hearth.  °  ' 

4.  Fiffs.  860,  8G1  represent  a  slag-heaith,  the  forneau  a  7nanchc (elbow  fm-n&Qe)  oi iho 

'--]  860 


French,  and  the  krummofen  (crooked  furnace)  of  the  Germans ;  such  as  is  used  at  Alston 
Moor,  in  Cumberland,  for  the  reduction  of  the  lead-slag.  It  resembles  the  Scotch 
furnace.  The  shaft  is  a  parallelepiped,  whose  base  is  26  inches  by  22  in  area  inside,  and 
whose  height  is  3  feet ;  the  sole-plate  a,  of  east  iron,  slopes  slightly  down  to  the  basin 
of  reception,  or  the  fore-hearth  b.  Upon  both  of  the  long  sides  of  the  sole-plate  there  are 
cast  iron  beams,  called  bearers,  c  c,  of  great  strength,  which  support  the  side  walls  built 
of  a  coarse  grained  sandstone,  a3  well  as  the  cast  iron  plate  d  {fore-stone),  which  forms 
the  front  of  the  shaft.  This  stands  7  inches  off  from  the  sole-plate,  leaving  an  empty 
space  between  them.  The  back  side  is  made  of  cast  iron  from  the  sole-phite  to  the 
horizontal  tuyere  in  its  middle;  but  above  this  point  it  is  made  of  sandstone.  The 
tuyere  is  from  1  ^  to  2  inches  in  diameter.  In  front  of  the  fore-hearth  b,  a  cistern  e  is 
placed,  through  which  water  continually  flows,  so  that  the  slags  which  spontaneously 
overflow  the  fore-hearth  may  become  inflated  and  shattered,  whereby  the  lea<l  dissemi- 
nated through  them  may  be'  readily  separated  by  washing.  The  lead  itself  flows  from 
the  fore-hearth  6,  through  an  orifice,  into  an  iron  poty,  which  is  kept  hot  over  a  fire. 
The  metal  obtained  from  this  slag-Uoarth  is  much  less  pure  than  that  extracted  directly 
from  the  ore. 

/ 


II  I 


48 


LEAD. 


LEAD. 


49 


1  !       I 


i    ' 

Si 


i      i 


i  1 


The  whole  bottom  of  the  furnace  is  filled  to  a  height  of  17  inches,  that  is,  to 
within  2  or  3  inches  of  the  tuyere,  with  the  rubbish  of  coke  reduced  to  coarse  powder 
and  beat  strongly  down.  At  each  smelting  shift,  this  bed  must  be  made  anew,  and  the 
interior  of  the  furnace  above  the  tuyere  repaired,  with  the  exception  of  the  front,  con- 
sisting of  cast  iron.  In  advance  of  the  furnace  there  is  a  basin  of  reception,  which  is 
also  filled  with  coke  rubbish.  Farther  off  is  a  pit,  full  of  water,  replenished  by  a  cold 
stream,  which  incessantly  runs  in  through  a  pipe.  The  scoriae,  in  flowing  out  of  the  fur- 
nace, pass  over  the  coke  bed  in  the  basin  of  reception,  and  then  fall  into  the  water,  whose 
coolness  makes  them  fly  into  small  pieces,  after  which  they  are  easily  washed,  so  as  to 
separate  the  lead  that  may  be  entangled  among  them. 

These  furnaces  are  urged,  in  general,  by  wooden  bellows ;  fig.  862.   But  at  the  smelting 


works  of  Lea,  near  Matlock,  the  blowing-machine  consists  of  two  casks,  which  move 
upon  horizontal  axes.  Each  of  these  casks  is  divided  into  two  equal  parts  by  a  fixed 
plane  that  passes  through  its  axis,  and  is  filled  with  water  to  a  certain  height.  The  water 
of  one  side  communicates  with  that  of  the  other  by  an  opening  in  the  lower  part  of  the 
division.  Each  cask  possesses  a  movement  of  oscillation,  produced  by  a  rod  attached  to 
a  crank  of  a  bucket-wheel.  At  each  demi-oscillation,  one  of  the  compartments,  being  in 
communication  with  the  external  air,  is  filled ;  while  the  other,  on  the  contrary,  communi- 
cates with  the  nozzle,  and  supplies  wind  to  the  furnace. 

5.  Refining  or  cupellation  furnace.    See  Silver. 

6.  Smelting  by  the  revcrberatory  furnace  is  adopted  exclusively  in  Derbyshire,  and  m 
some  works  at  Alston  Moor.  The  charge  in  the  hopper  consists  commonly  of  16  cwts., 
each  weighing  120  lbs.  avoirdupois,  composed  of  an  intimate  mixture  of  5,  6,  7,  or  even 
8  kinds  of  ore,  derived  from  different  mines,  and  prepared  in  different  ways.  The  pro- 
portions of  the  mixture  are  determined  by  experience,  and  are  of  great  consequence  to  the 
success  of  the  work. 

The  ore  is  rather  in  the  form  of  grains  than  of  a  fine  schlick  ;  it  is  sometimes  very  pure, 
and  affords  75  per  cent. ;  but  usually  it  is  mixed  up  with  a  large  proportion  of  carbonate 
and  fluate  of  lime ;  and  its  product  varies  from  65  to  23  jKr  cent. 

After  scraping  the  slaggy  matters  out  of  the  furnace,  a  fresh  smelting  shift  is  intro- 
duced at  an  interval  of  a  few  minutes ;  and  thus,  by  means  of  two  alternate  work- 
men, who  relieve  each  other  every  seven  or  eight  hours,  the  weekly  operations  continue 
without  interruption.  The  average  product  in  lead  of  the  revcrberatory  furnaces  in 
Derbyshire,  during  several  years,  has  been  66  per  cent,  of  the  ore.  Very  fine  ore  has, 
however,  afforded  76. 

T.  Smelh'nsr  ofthedraxon  slag,  on  the  slag-mill  hearth.— The  black  slag  of  the  revcrbe- 
ratory I  urnace  IS  broken  by  hammers  into  small  pieces,  and  mixed  m  proper  pnptjriione 
with  ine  coal  cinders  that  fall  through  the  grate  of  the  reverberatorv  fire.  The  leaden 
matts  that  float  on  the  surface  of  the  bath,  and  the  dust  deposited  in  the  chimney 
are  added,  along  with  some  poor  ore  containing  a  gangue  of  fluor  spar  and  limestone^ 
which  had  been  put  aside  during  the  machanical  preparation.  With  such  a  mixture,  the 
slag-hearth,  already  described  y/gs.  860,  861,  is  charged.  By  the  action  of  heat  and  coal, 
the  lead  IS  revived,  the  earthy  matters  flow  into  very  liquid  scoriae,  and  the  whole  is 
made  to  pass  across  the  body  cf  fire  into  a  basin  of  reception  placed  beneath.  The 
scoriae  are  thickened  by  throwing  quicklime  upon  them,  and  they  are  then  raked 
away.  At  the  end  of  the  operation  the  lead  is  cast  into  pigs  or  ingots  of  a  peculiar 
form.  This  is  called  slag-lead.  It  is  harder,  more  sonorous  than  the  lead  obtained  from 
the  reverberatory  furnace,  and  is  prefeiTed  for  the  manufacture  cf  minium,  lead  shot,  and 
some  other  purposes. 

8.  Treatment  of  lead  ores  by  the  Scotch  furnace,  or  ore-hearth .—This  furnace  is  gener- 
ally emjdoyed  in  the  counties  of  Northumberland,  Cumberland,  and  Durham,  for  the 
smelting  of  lead  ores,  which  were  formerly  carried  to  them  without  any  preparation, 


but  now  they  are  exposed  to  a  preliminary  calcination.  The  roasted  ore  yields  in  the 
Scotch  furnace  a  more  considerable  product  than  the  crude  ore,  because  it  forms  in  the 
furnace  a  more  porous  mass,  and  at  the  same  time  it  vx/rks  drier,  to  use  the  founder's  ex- 
pression ;  that  is,  it  allows  the  stream  of  air  impelled  by  the  bellows  lo  diffuse  itself  mor« 
completely  across  the  matters  contained  in  the  furnace. 

The  charge  of  the  roasting  furnace,  figs.  631,  632,  633,  is  from  9  to  11  cwts.  of  o»e, 
put  into  the  furnace  without  any  addition.  Three  such  shifts  are  usually  passed  through 
in  eight  hours.  The  fire  should  be  urged  in  such  a  manner  as  to  produce  constantly  a 
dense  smoke,  without  letting  any  part  of  the  ore  melt  and  form  a  slag ;  an  accident 
which  would  obstruct  the  principal  end  of  the  process,  which  is  to  burn  off  the  sulphur  and 
antimony,  and  to  expel  the  carbonic  acid  of  the  carbonate  of  lead.  The  ore  must  be  fre- 
quently turned  over,  by  moving  it  from  tlie  bridge  to  the  other  end  and  back  again.  To 
prevent  the  ore  from  running  into  masses  as  it  cools,  it  is  made  to  fall  out  of  the  furnace 
into  a  pit  full  of  water,  placed  below  one  of  the  lateral  doors. 

Smelting  of  the  lead  ores  in  the  Scotch  furnace.— When  a  smelting  shift  has  been 
finished  in  the  Scotch  furnace,  a  portion  of  the  ore,  called  browse,  remains  in  a  semi- 
reduced  state,  mixed  with  coke  and  cinders.     It  is  found  of  more  advantage  to  preserve 
the  browse  for  beginning  the  following  operation,  than  to  take  raw  or  even  roasted 
ore.    To  set  the  furnace  in  action,  the  interior  of  it  is  filled  with  peats,  cut  into  the 
form  of  bricks.     The  peats  towards  the  posterior  part  are  heaped  up  without  order, 
but  those  near  the  front  are  piled  up  with  care  in  the  form  of  a  wall.     A  kindled  peat 
is  now  placed  before  the  nozzle  of  the  bellows,  which  are  made  to  blow,  and  the  blast 
spreads  the  combustion  rapidly  through  the  whole  mass.     To  increase  the  heat,  and  to 
render  the  fire  more  steady  and  durable,  a  few  shovelfuls  of  coals  are  thrown  over  the 
turf.     A  certain  quantity  of  the  browse  is  to  be  next  introduced;  and  then  (or  some- 
times before  all  the  browse  is  put  in)  the  greater  part  of  the  matters  contained  in  the 
furnace  is  drawn  over  on  the  work-stone,  by  means  of  a  large  rake  called  a  gowelock;  the 
refuse  of  the  ore  called  gray  slag,  which  a  skilful  smelter  knows  by  its  shining  more 
than  the  browse,  is  taken  off  with  a  shovel,  and  thrown  to  the  right  hand  into  a  comer 
outside  of  the  furnace.     The  browse  left  on  the  work-stone  is  to  be  now  thrown  back 
into  the  furnace,  with  the  addition  of  a  little  coal,  if  necessarj-.    If  the  browse  be  not 
well  cleaned  from  the  slag,  which  is  perceived  by  the  whole  mass  being  in  a  soft  state, 
and  showing  a  tendency  to  fuse,  quicklime  must  be  added,  which  by  its  affinity  for  the 
argillaceous,    silicious,  and  ferruginous    substances,  dries    up    the    materials,  as    the 
smelters  say,  and  gives  to  the  earthy  parts  the  property  of  concreting  into  lumps  or 
balls ;    but  if,  on  the  other  hand,  the  silicious,  argillaceous,  or  ferruginous  parts  con- 
tained in  the  ore  be  too  refractory,  lime  is  also  to  be  added,  but  in  smaller  quantity, 
which,  by  rendering  them  more  fusible,  communicates  the  property  of  concreting  into 
balls.     These  lumps,  called  gray  slag,  contain  from  one  tenth  to  one  fifteenth  of  the 
lead  which  was  present  in  the  ore.     They  must  be  smelted  afterwards  at  a  higher  tem- 
perature in  the  slag  hearth,  to  extract  their  lead.     After  the  browse  has  been  thrown 
back  into  the  furnace,  as  has  been  said,  a  few  shovelfuls  of  ore  are  to  be  strewed  over 
it ;  but  before  doing  this,  and  after  removing  the  scoriae,  there  must  be  always  placed 
before  the  tuyere  half  a  peat,  a  substance  which  being  extremely  porous  and  combustible, 
not  only  hinders  any  thing  from  entering  the  nozzle  of  the  bellows,  but  spreads  the  blast 
through  all  the  vacant  parts  of  the  furnace.    After  an  inter\al  of  from  10  to  15  minutes, 
according  to  circumstances,  the  materials  in  the  furnace  are  drawn  afresh  upon  the  work- 
stone,  and  the  gray  slag  is  removed  by  the  rake.     Another  peat  being  placed  before  the 
tuyere,  and  coal  and  quicklime  being  introduced  in  suitable  proportions,  the  browse  is 
thrown  back  into  the  furnace,  a  fresh  portion  of  ore  is  charged  above  it,  and  left  in  the 
furnace  for  the  above-mentioned  time. 

This  mode  of  working,  continued  for  14  or  15  hours,  forms  what  is  called  a  sinelting 
mift ;  in  which  time  from  20  to  40  cwts.  of  lead,  and  even  more,  are  produced. 

By  this  process  the  purest  part  of  the  lead,  as  well  as  the  sUver,  are  sweated  out,  as  it 
were,  from  the  materials  with  which  they  are  mixed,  without  anything  entering  into 
fusion  except  these  two  metals  in  the  state  of  aUoy.  It  is  probable  that  the  moderate 
temperature  employed  in  the  Scotch  furnace  is  the  main  cause  of  the  purity  of  the  lead 
which  It  yields. 

9.  SmeUing  of  the  scoria  of  the  Scotch  furnace  on  the  slag  hearth.— Before  putting  fire  to 
the  slag  hearth  akeady  described,  figs.  635,  636,  its  empty  space  is  to  be  filled  with  peats, 
ana  a  lighted  one  being  placed  before  the  tuyere,  the  beUows  are  made  to  play.  A  layer 
01  coke  IS  to  be  now  thrown  upon  the  burning  peats,  and  as  soon  as  the  heat  is  sufficiently 
nigh,  a  layer  of  the  gray  slag  is  to  be  introduced,  or  of  any  other  scoriae  that  are  to 
t)e  reduced,  from  tune  to  time,  as  the  fit  moment  arrives,  alternate  strata  of  coke  and 
Slag  are  to  be  added  In  this  operation,  though  the  slag  and  the  lead  are  brought  to  a 
•late  01  perfect  fluidity,  the  metal  gets  separated  by  filtering  down  through  the^bed  of 
Vol.  IL  ^ 


60 


LEAD. 


LEAD. 


51 


|i  I 


peat  cinders,  which  the  slag  cannot  do  on  account  of  its  viscidity.  Whenever  that  coke 
bed  becomes  covered  with  fluid  slag,  the  workman  makes  a  hole  in  it,  of  about  an  inch 
diameter,  by  means  of  a  kneed  poker ;  and  runs  it  off  by  this  orifice,  as  it  cannot  sink 
down  into  the  hard  rammed  cinders,  which  fill  the  basin  of  reception.  The  slag  flows 
over  it  in  a  glowing  stream  into  the  pit  filled  with  water,  where  it  gets  granulated  and 
readv  for  washing. 

When  lead  is  obtained  from  galena  without  the  addition  of  combustible  matter,  we 
havt  an  example,  on  the  great  scale,  of  the  mutual  decomposition  of  the  oxydes  and  sul- 
phates formed  during  the  roasting  heat,  by  the  still  undecomposed  galena,  especially  when 
this  action  is  facilitated  by  working  up  and  skilfully  mingling  the  various  matters,  as  hap- 
pens in  the  reverberatory  and  Scotch  furnaces.  It  is  therefore  thesulphuret  of  lead  itself 
which  serves  as  the  agent  of  reduction  in  regard  to  the  oxyde  and  sulphate,  when  little 
or  no  charcoal  has  been  added.  Sometimes,  however,  towards  the  end  of  the  operation 
in  the  reverberatory  hearth,  it  becomes  necessarj'  to  throw  in  some  wood  or  charcoal, 
because  the  oxydizement  having  become  too  complete,  there  does  not  remain  a  sufticient 
body  of  sulphuret  of  lead  to  eflect  the  decompositions  and  reductions  just  mentioned,  and 
therefore  it  is  requisite  to  regenerate  some  galena  by  means  of  carbonaceous  matter, 
which  immediately  converts  the  sulphate  of  lead  into  the  sulphuret.  The  sulphur  and 
oxygen  are  eventually  all  separated  in  the  form  of  sulphurous  acid.  Roasted  galena 
contains  sometimes  no  less  than  77  per  cent,  of  sulphate  of  lead. 

At  Viconago,  in  the  Valais,  the  process  of  smelting  lead  ore  in  the  reverberatory  fur- 
nace, with  the  addition  of  iron,  as  practised  at  Vienne,  on  the  Isere,  was  introduced ; 
but  the  difficulty  of  procuring  a  sufficient  supply  of  old  iron  has  led  to  an  interesting 
modification. 

On  the  hearth  of  the  reverberatory  furnace,  10  quintals  of  moderately  rich  ore  arc 
spread ;  these  are  heated  temperately  for  some  time,  and  stirred  about  to  promote  the 
sublimation  of  the  sulphur.  After  three  or  four  hours,  when  the  ore  seems  to  be  suffi- 
ciently desulphureted,  the  heat  is  raised  so  as  to  melt  the  whole  materials,  and  when- 
ever they  flux  into  a  metallic  glass,  a  few  shovelfuls  of  bruised  charcoal  or  cinders  are 
thrown  in,  which  soon  thicken  the  liquid,  and  cause  metallic  lead  to  appear.  By  this 
means  three  foirrlhs  of  the  lead  contained  in  the  ore  are  usually  extracted  ;  but  at  length 
the  substance,  becoming  less  and  less  fluid,  yields  no  more  metal.  Stamped  and  washed 
carbonate  of  iron  (sparry  iron  ore)  is  now  added,  in  the  proportion  of  about  10  per  cent, 
of  the  lead  ore  primarily  introduced. 

On  stirring  and  working  together  this  mixtxire,  it  assumes  the  consistence  of  a  stiff 
paste,  which  is  raked  out  of  the  furnace.  When  this  has  become  cold,  it  is  broken  into 
pieces,  and  thereafter  smelted  in  a  slag-hearth,  without  the  addition  of  flux.  By  this 
operation  almost  the  whole  lead  present  is  obtained.  100  quintals  of  schlich  yield  45 
of  argentiferous  lead  ;  and  in  the  production  of  100  quintals  (cwts.)  of  marketable  lead, 
140  cubic  feet  of  beech-wood,  and  357|  quintals  of  charcoal  are  consumed. 

This  process  is  remarkable  for  the  use  of  iron-ore  in  smelting  galena. 

10.  Reduction  in  the  reverberatory  furnace  of  the  litharge  obtained  in  the  refining  of 
Zcod.— The  litharge  of  Alston  Moor  is  seldom  sold  as  such,  but  is  usually  converted  into 
lead,  in  a  reverberatory  furnace. 

In  ccmmencing  this  reduction,  a  bed  of  coal  about  2  inches  thick  is  first  of  all  laid 
on  the  hearth;  which  is  soon  kindled  by  the  flame  of  the  fire-place,  and  in  a  little  while 
is  reduced  to  red  hot  cinders.  Upon  these  a  certain  quantity  of  a  mixture  of  litharge 
and  small  coal  is  uniformly  spread  ;  the  heat  of  the  fire-place  being  meanwhile  so  man- 
aged as  to  maintain  in  the  furnace  a  suitable  temperature  for  enabling  the  combustible  to 
deprive  the  litharge  of  its  oxygen,  and  to  convert  it  into  lead.  The  metal  is  run  out  by 
the  tap-hole  into  an  iron  pot ;  and  being  cast  into  pigs  of  hLlf  a  hundred  weight,  is  sold 
under  the  name  of  refined  lead  at  a  superior  price. 

The  quantity  of  small  coal  mixed  with  the  litharge  should  be  somewhat  less  than  what 
may  be  necessary  to  efl^ect  the  reduction,  because  if  in  the  course  of  the  process  a  defi- 
ciency of  it  is  perceived  in  any  part  of  the  furnace,  more  can  always  be  added ;  whereas 
a  redundancy  of  coal  necessarily  increases  the  quantity  of  slag,  which,  at  the  end  of  the 
shift,  must  be  removed  from  the  furnace  before  a  new  operation  is  begun,  whereby  lead 
is  lost.  In  the  reverberatory  furnace,  six  fodders  of  lead  may  be  revived  in  nine  or  ten 
hours ;  during  the  first  six  of  which  the  mixture  of  litharge  and  coal  is  added  at  short 
intervals.     A  fodder  is  from  21  to  24  cwts. 

It  deserves  to  be  remarked  that  the  work  does  not  go  on  so  well  nor  so  quick  when 
the  coal  and  litharge  are  in  a  pulverulent  form ;  because  the  reduction  in  this  case 
takes  place  only  at  the  surface,  the  air  not  being  able  to  penetrate  into  the  body,  and  to 
keep  up  its  combustion,  and  the  mutual  action  of  the  litharge  and  carbon  in  the  interior. 
But,  on  the  other  hand,  when  the  litharge  is  in  porous  pieces,  as  large  as  a  hen's  t^^y 
the  action  pervades  the  whole  body,  and  the  sooty  fumes  of  the  coal  eflect  the  reduction 


even  in  the  centre  of  the  fingments  ol  the  litharge,  penetrating  into  every  fissure  and 
carrying  off  the  oxygen.  The  heat  ought  never  to  be  urged  so  far  as  to  melt  the 
litharge. 

The  grounds  of  the  cupel,  and  the  slag  of  the  reduction  furnace,  being  a  mixture  cS 
small  coke,  coal  ash,  and  oxyde  of  iron,  more  or  less  imj  s-cgnated  with  lead,  are  smelted 
upon  the  slag  hearth,  along  with  coke,  and,  by  way  of  flux,  with  a  certain  quantity  of  the 
black  scoriae  obtained  from  the  same  furnace,  prepared  for  this  purpose,  by  running  it 
out  in  thin  plates,  and  breaking  it  into  small  pieces.  The  lead  thus  obtained  is  usually 
very  white,  very  hard,  and  not  susceptible  of  refinement. 

MM.  Dufrenoy  and  Beaumont  consider  the  smelting  of  lead  ore  by  the  reverberatory 
furnace,  as  practised  in  Derbyshire,  as  probably  preferable  to  that  with  the  slag  hearth 
as  carried  on  in  Brittany ;  a  process  which  seldom  gives  uniform  products,  while  it  occa- 
sions a  more  considerable  waste  of  lead  and  consumption  of  fuel. 

The  mixed  process  employed  in  Cumberland  of  roasting  the  ore,  and  afterwards 
smelting  it  in  a  small  furnace  resembling  that  called  the  Scotch,  apparently  yields  a 
little  less  lead  than  if  both  operations  were  executed  in  the  reverberatory  furnace ;  but 
according  to  Mr.  Forster  (see  his  Treatise  on  a  Section  of  the  Strata  from  Newcastle 
upon  Tyne,  &c.),  this  slight  loss  is  more  than  compensated  by  the  smaller  consumption 
of  fuel,  the  increased  rapidity  of  the  operation,  and  especially  by  the  much  greater 
purity  of  the  lead  obtained  from  the  Scotch  furnace.  When  it  comes  to  be  refined,  the 
loss  is  only  about  one  twelfth  or  one  thirteenth,  whereas  the  lead  revived  in  the  rever- 
beratory furnace  loses  frequently  a  ninth.  Moreover,  the  lead  furnished  by  the  first 
method  admits  of  being  refined  with  profit,  when  it  yields  only  5  ounces  of  silver  per 
fodder  of  20  quintals,  jx>ids  de  marc,  while  that  produced  by  the  reverberator)'  furnace 
cannot  be  cupelled  unless  it  gives  10  ounces  per  fodder ;  and  as  in  the  English  cupel- 
lation  lead  is  constantly  added  anew  without  skimming,  the  litharge  obtained  in  the 
second  case  can  never  be  brought  into  the  market,  whereas  the  litharge  of  the  leads  from 
ihe  Scotch  furnace  is  of  good  quality.  See  the  new  method  of  enriching  lead  for  cupel* 
lation,  under  Silver. 

As  the  smelting  of  galena,  the  principal  ore  of  lead,  is  not  a  little  complex,  the  follow- 
ing tabular  view  of  the  different  processes  may  prove  acceptable  to  the  metallurgist  i^ 


I.  Class. 
Treated  in  re- 
verberatory 
furnaces. 


A 
Desulphura- 
tion  by  roast- ' 
ing. 


Treatment  of 

'  1.  Pure  ores. 
2.  Ores   mixed  with  > 
saline  gangues.      > 


II.  Class. 
Treated  in  the 
mill-slag- 
hearth,  the 
fourneau  H 
manche,  or 
Scotch  fur- 
nace. 


< 


B 

Desulphura- 
tion  by  iron. 

A 

Founding  after 
roasting  in  a 
heap,  or  in  a 
reverbera- 
tory. 


3.  Ores   mixed  with 
earthy  gangues. 


4.  Ores   mixed  with 
several    sulphu- 
rets. 

5.  Ores  with  earthy, ' 
saline,    and    sul- 
phurous    gan- 
gues. 

6.  Ores  with  mattes, 
as  at  Vienne,  in 
Dauphiny. 


Process  of 

Pesey,  Spain,  &c. 

England,  in  gen- 
eral. 

Vicenago,  in 
Italy,  and  Red- 
ruth, in  Corii> 
wall. 

Combined   with 
the  above. 


\ 


B 

Founding  with 
direct  de- 
sulphuralion, 
by  metallic 
iron. 


7.  Ores  producing 
slags  of  various  < 
silicates. 

8.  Ores  producing  | 
compound  sili-  \ 
cate  sla?s.  | 

I 

9.  Ores  producing  f 

slags  composed  { 
of  silicates  and^ 
subsilicates. 


Vienne,  Poulla- 
ouen,  and  Tar- 
nowitz. 

Mattes,  with  raw 

lead. 
Workable     lead,    ^ 

without  mattes.  ^ 
Mattes  and  work-  ) 

able  lead.  s 

Workable  lead. 

Mattes  and  work- 
able lead. 


Poor    mattes  and 
workable  lead. 


Many    pla- 
ces. 

Villefoit. 

Several  pla- 
ces. 
PontGibani 

and  Scotch 

furnace. 
Baad-Ems 

Hartz, 

Tarnowitz. 

Tamciwitz. 


/ 


52 


LEAD-SHOT. 


The  annual  production  of  lead  in  Europe  may  be  estimated  at  about  80,000  tons ;  of 
which  four  sevenths  are  produced  in  England,  two  sevenths  in  Spain,  the  remainder  in 
Germany  and  Russia.  France  does  not  produce  more  than  one  five-hundredth  part  of  the 
whole ;  and  only  one  fiAieth  of  its  consumption. 

See  Litharge,  Minium,  or  Red  Lead,  Solder,  Sugar  or  Acetate  of  Lead,  Type 
Metal,  and  White  Lead. 

LEAD-SHOT  (Plomb  de  chasse,  Fr. ;  Schrot,  Flintenschrotj  Germ.).  The  origin  of 
most  of  the  imperfections  in  the  manufacture  of  lead-shot  is  the  too  rapid  cooling  of  the 
spherules  by  their  being  dropped  too  hot  into  the  water,  whereby  their  surfaces  form  a 
solid  crust,  while  their  interior  remains  fluid,  and,  in  its  subsequent  concretion,  shrinks, 
80  as  to  produce  the  irregularities  of  the  shot. 

The  patent  shot  towers  originally  constructed  in  England  obviate  this  evil  by  exposing 
the  fused  spherules  after  they  pass  through  the  cullender,  to  a  large  body  of  air  during 
their  descent  into  the  water  tub  placed  on  the  ground.  The  greatest  erection  of  this  kind 
is  probably  at  Villach,  in  Carinthia,  being  210  Vienna,  or  249  English  feet  high. 

The  quantity  of  arsenic  added  to  the  mass  of  melted  lead,  varies  according  to  the 
quality  of  this  metal ;  the  harder  and  less  ductile  the  lead  is,  the  more  arsenic  must  be 
added.  About  3  pounds  of  either  white  arsenic  or  orpiment  is  enough  for  one  thousand 
parts  of  soil  lead,  and  about  8  for  the  coarser  kinds.  The  latter  are  employed  preferably 
for  shot,  as  they  are  cheaper  and  answer  sufficiently  well.  The  arsenical  alloy  is  made 
either  by  introducing  some  of  this  substance  at  each  melting,  or  by  making  a  quantity  of 
the  compound  considerably  stronger  at  once,  and  adding  a  certain  portion  of  this  to  each 
charge  of  lead.  If  the  particles  of  the  shot  appear  lens  shaped,  it  is  a  proof  that  the 
proportion  of  arsenic  has  been  too  great ;  but  if  they  are  flattened  upon  one  side,  if  they 
are  hollowed  in  their  middle,  called  cupping  by  the  workman,  or  drag  with  a  tail  behind 
them,  the  proportion  of  arsenic  is  too  small. 

The  following  is  the  process  prescribed  by  the  patentees,  Ackerman  and  Martin.  Melt 
a  ton  of  soft  lead,  and  sprinkle  round  its  sides,  in  the  iron  pot,  about  two  shovelfuls  of 
wood  ashes,  taking  care  to  leave  the  centre  clear ;  then  put  into  the  middle  about  40 
pounds  of  arsenic  to  form  a  rich  alloy  with  the  lead.  Cover  the  pot  with  an  iron  lid,  and 
lute  the  joints  quickly  with  loam  or  mortar,  to  confine  the  arsenical  vapors,  keeping  up 
a  moderate  fire  to  maintain  the  mixture  fluid  for  three  or  four  hours ;  aAer  which  skim 
carefully,  and  run  the  alloy  into  moulds  to  form  ingots  or  pigs.  The  composition  thus 
made  is  to  be  put  in  the  proportion  of  one  pig  or  ingot  into  1000  pounds  of  melted  ordi- 
nary lead.  When  the  whole  is  well  combined,  lake  a  perforated  skimmer  and  let  a  few 
drops  of  it  fall  from  some  height  into  a  tub  of  water.  If  they  do  not  appear  globular, 
some  more  arsenical  alloy  must  be  added. 

Lead  which  contains  a  gowl  deal  of  pewter  or  tin  must  be  rejected,  because  it  tends  to 
produce  elongated  drops  or  tails. 

From  two  to  three  ions  are  usually  melted  at  once  in  the  large  establishments.  The 
surface  of  the  lead  gets  covered  with  a  crust  of  oxyde  of  a  white  spongy  nature,  some- 
times called  cream  by  the  workmen,  which  is  of  use  to  coat  over  the  bottom  of  the  cul- 
lender, because  without  such  a  bed  the  heavy  melted  lead  would  run  too  rapidly  through 
the  holes  for  the  granulating  process,  and  would  form  oblong  spheroids.  The  mounting 
of  this  filter,  or  lining  of  the  cullender,  is  reckoned  to  be  a  nice  operation  by  the  work- 
men, and  is  regarded  usually  as  a  valuable  secret. 

The  cullenders  are  hollow  hemispheres  of  sheet  iron,  about  10  inches  in  diameter,  per- 
ibrated  with  holes,  which  should  be  perfectly  round  and  free  from  burs.  These  must  be 
of  a  uniform  size  in  each  cullender ;  but  of  course  a  series  of  different  cullenders,  with 
sorted  holes  for  every  different  size  of  lead  shot,  must  be  prepared.  The  holei?  have 
nearly  the  following  diameters  for  the  annexed  numbers  of  shot. 

No.  0. 


1. 
2. 
3. 
4. 


JL  of  an  inch. 

,  1  

80 


From  No.  5  to  No.  9  the  diameter  decreases  by  regular  gradations,  the  latter  being  only 
,1-.  of  an  inch. 

•  60 

The  operation  is  always  carried  on  with  three  cullenders  at  a  time ;  which  are  sup- 
ported upon  projecting  grates  of  a  kind  of  chafing  dish  made  of  sheet  iron  somewhat  like 
a  triangle.  This  chafing  dish  should  be  placed  immediately  above  the  fall ;  while  at  its 
bottom  there  must  be  a  tub  half  filled  with  water  for  receiving  the  granulated  lead.  The 
cullenders  are  not  in  contact,  but  must  be  parted  by  burning  charcoal,  in  order  to  keep  the 
lead  constantly  at  the  proper  temperature,  and  to  prevent  its  solidifying  in  the  filter.  The 
temperature  of  the  lead  bath  should  vary  with  the  size  of  the  shot ;  for  the  largest,  it 


LEAD. 


58 


should  be  such  that  a  bit  of  straw  plunged  into  it  will  be  scarcely  browned,  but  for  all  it 
should  be  nicely  regulated.  The  height  from  which  the  particles  should  be  let  fall  varies 
likewise  with  the  size  of  the  shot ;  as  the  congelation  is  the  more  rapid,  the  smaller  they 
are.  With  a  fall  of  33  yards  or  100  feet,  from  No.  4  to  No.  9  may  be  made  j  but  for 
larger  sizes,  150  feet  of  height  will  be  required. 

Every  thing  being  arranged  as  above  described,  the  workman  puts  the  filter-stuff  into 
the  cullender,  pressing  it  well  against  the  sides.  He  next  pours  lead  into  it  with  an  iron 
ladle,  but  not  in  too  great  quantity  at  a  time,  lest  it  should  run  through  too  fast.  The 
shot  thereby  formed  and  found  in  the  tub  are  not  all  equal. 

The  centre  of  the  cullender  being  less  hot  affords  larger  shot  than  the  sides,  which  arc 
constantly  surrounded  with  burning  charcoal.  Occasionally,  also,  the  three  cullenders 
employed  together  may  have  holes  of  different  sizes,  in  which  case  the  tub  may  contain 
shot  of  very  various  magnitudes.  These  arc  separated  from  each  other  by  square 
sieves  of  different  fineness,  10  inches  broad  and  16  inches  long,  their  bottoms  being  of 
sheet  iron,  pierced  with  holes  of  the  same  diameters  as  those  of  the  cullenders.  These 
sieves  are  suspended  by  means  of  two  bands  above  boxes  for  receiving  the  shot ;  one 
sieve  being  usually  set  above  another  in  consecutive  numbers,  for  instance,  1  and  2.  The 
shot  being  put  into  the  upper  sieve,  No.  0  will  remain  in  it.  No.  1  will  remain  in  the 
lower  sieve,  and  No.  2  will,  with  all  the  others,  pass  through  it  into  the  chest  below.  It  is 
obvious  that  by  substituting  sieves  of  successive  fineness,  shot  of  any  dimension  may  be 
sorted. 

In  the  preceding  process  the  shot  has  been  sorted  to  size ;  it  must  next  be  sorted  to 
form,  so  as  to  separate  all  the  spheroids  which  are  not  truly  round,  or  are  defective  in  any 
respect.  For  this  purpose  a  board  is  made  use  of  about  27  inches  long  and  16  broad, 
furnished  partially  with  upright  ledges ;  upon  this  tray  a  handful  or  two  of  the  shot  to  be 
sortefl  being  laid,  it  is  inclined  very  slightly,  and  gently  shaken  in  the  horizontal  direction, 
when  the  globular  particles  run  down  by  one  edge,  into  a  chest  set  to  receive  them,  while 
those  of  irregular  forms  remain  on  the  sides  of  the  tray,  and  are  reserved  to  be  remelled. 

Afler  being  sorted  in  this  way,  the  shot  requires  still  to  be  smoothed  and  polished 
bright.  This*  object  is  effected  by  putting  it  into  a  small  octagonal  cask,  through  a  door 
in  its  side,  turning  ui)on  a  horizontal  iron  axis,  which  rests  in  plummer  boxes  at  its  ends, 
and  is  made  to  revolve  by  any  mechanical  power.  A  certain  quantity  of  plumbago  or 
black  lead  is  put  in  along  with  the  shot. 

Lead  acted  on  by  pure  water  so  as  to  make  it  poisonoits. — ^Dr.  H.  Guenaude  Mussy 
was  summoned  to  Claremont  in  the  beginning  of  October,  1848  ;  and  on  his  arrival 
was  shown  into  the  room  of  one  of  the  members  of  the  ex-royal  family  of  France,  who 
had  been  residing  there  since  the  preceding  March.  He  found  him  lying  down,  with 
an  anxious  countenance,  the  conjunctiva  of  a  yellowish  color,  and  the  flesh  flabby, 
evidently  proving  a  loss  of  substance.  He  told  him  he  had  been  suffering  for  several 
days  from  violent  colics,  which  had  been  relieved  after  a  constipation  of  two  days  by 
abundant  alvine  evacuations,  produced  by  a  purgative  draught.  This  was  the  third 
attack  of  the  same  nature  during  the  space  of  five  weeks.  Some  time  before,  towards 
the  end  of  July,  he  had  been  suffering  from  colic,  with  nausea,  frequent  eructations  and 
irregularity  of  the  bowels. 

"  I  learnt  that  a  brother  of  my  patient  had  experienced  the  same  symptoms ;  but  no 
one  was  astonished  at  it,  as  it  was  supposed  he  was  suffering  under  a  liver  complaint 
contracted  on  the  western  coast  of  Africa. 

"  A  third  patient,  of  forty-eight  years  of  age,  who  was  also  subject  to  constipation, 
had  violent  colic  a  few  days  before,  attended  with  nausea  and  even  vomiting. 

"  A  few  days  elapsed,  and  no  bad  symptoms  disturbed  our  security.  My  patients 
had  resumed  their  usual  occupations,  and  good  appetites  and  pretty  fair  digestion,  but 
were  still  very  weak ;  and  pale  sallow  complexions  had  replaced  the  icteric  color. 

"  My  delusions  did  not  last  long.  About  ten  days  after,  a  new  access  of  symptoms 
began,  with  a  painful  sensation  of  constriction  about  the  epigastric  region,  anxiety, 
nausea,  and  eructations." 

After  describing  the  symptoms  and  the  treatment  resorted  to  before  the  real  cause  of 
the  disorder  was  suspected,  the  doctor  mentions  the  circumstances  which  led  to  the 
discovery,  which  induced  him  to  administer  sulphur  in  combination  with  iron  internally, 
and  to  order  sulphurous  and  soapy  baths.     He  proceeds : — 

"  The  chemical  action  showed  itself  almost  immediately  by  the  black  discoloration 
of  the  nails  of  the  feet  and  hands,  and  by  the  appearance  of  similar  spots  on  different 
parts  of  the  skin. 

"One  of  the  patients  came  out  from  the  second  bath  with  the  abdomen  entirely  black. 
The  soapy  frictions  and  baths  usually  washed  away  the  spots  from  the  skin,  put  not 
those  of  the  nails.    The  appearance  of  this  reaction,  which  ii  very  common  with  men 


/ 


u 


LEAD. 


LEATHER. 


56 


workin«  in  lead  manufactories  when  using  sulphurous  baths,  ia  explained  by  the  com- 
bination of  sulphur  with  the  saturnine  molecules  adhering  to  the  skin. 

"In  these  cases  it  was  evident  that  the  lead  was  brought  to  the  surface  of  the  body 
by  means  either  of  subdaminal  or  follicular  exhalations,  and  perhaps  by  both. 

"The  metal  is  eliminated  and  transformed  into  sulphuret  of  lead  by  the  sulphurous 
baths,  and  then  taken  off  by  the  soapy  frictions  and  baths. 

"These  were  not  useless,  for  without  them  the  lead  deposited  on  the  surface  might 
have  been  carried  again  by  absorption  into  the  economy. 

"But  the  skin  was  not  the  only  means  of  giving  exit  to  the  poison.  I  discovered  U 
in  the  urine  by  a  solution  of  hydros^lphate  of  ammonia.  Some  physicians  and  chemists 
look  on  sulphur  as  the  only  efficacious  remedy;  others,  on  the  contrary,  assert  that  it 

is  without  any  effect.  a  r*     *  *u     ^ 

"What  I  can  tell  you  is,  that  the  success  was  beyond  my  hopes.   After  two  or  three 
weeks  I  had  the  satisfaction  of  seeing  my  patients  progressing  rapidly  and  surely  to 
wards  recovery.     This  happy  result  induced  me  to  try  the  same  means  with  another 
person,  older  and  of  a  weaker  constitution,  and  consequently  for  whom  I  was  most 
uneasy,  and  the  result  was  as  satisfactory. 

"  One  of  my  patients  was  accustomed  to  drink  Vichy  water  at  table.  Ihis  was  a  very 
unfortunate  predisposing  circumstance :  it  is  probable  that  the  salt  of  Vichy  water,  t  e. 
bicarbonate  of  soda,  united  to  the  bed  of  Claremont  water,  had  much  to  do  with  the 
violence  of  the  attack  under  which  he  suffered.  .  ,    i  • 

"  At  the  time  of  my  arrival  at  Claremont,  there  were  thirty-eight  inhabitants. 
"Tliirteen  of  these  had  been  attacked,  eleven  men  and  two  women.     Four  of  them 
■  had  some  symptoms  two  months  previously  to  my  arrival,  the  other  cases  occurred 
under  my  own  eyes.     Some  even  after  the  pipes  had  been  cut  oflF  were  aflfected,  and 
on  the  continent  a  week  after  leaving  England. 

"Six  children  in  the  household,  aged  from  three  to  seven  years,  have  been  exempt 
from  it.    Only  half  of  the  patients  have  had  the  gums  marked  with  the  slate-colored  line 
and  spots  of  the  same  color  on  the  raucous  membrane  of  the  mouth,  and  these  spots 
and  the  bluish  line  of  the  gums,  were  observed  on  several  others  who  did  not  experience 
or  exhibit  anything  else,  and  those  signs  of  the  poison  having  been  taken  into  the  econ- 
omy have  not  yet  disappeared.     The  morbid  cause  has  acted  in  these  cases,  as  it  often 
does  with  caprice,  and  according  to  individual  dispositions  which  defy  every  reason mg. 
"The  malady  has  shown  no  respect  for  condition,  and  attacked  indiscriminately  ser- 
vants, aides-de-camps  and  princes.  .  r  j 
"The  spring  that  furnishes  the  palace  of  Claremont  with  water  issues  from  a  sand 
bed  at  about  two  miles  distance.     It  was  chosen  for  its  uncommon  purity  from  among 
.  a  great  many  others  in  its  vicinity,  and  the  water  was  thirty  years  ago  conducted  to 
the  palace  through  leaden  pipes.     In  the  present  day  some  other  metal  would  perhaps 
have  been  selected,  for  experience  has  taught  us  that  pure  water,  and  especially  dis- 
tilled water,  acts  rapidly  on  lead  when  it  comes  in  contact  with  »K   ^  ,      .      ^, 

"  Thus  Tronchin  proved  that  the  inhabitants  of  Amsterdam  were  indebted  to  the  ram 
water  kept  in  leaden  cisterns,  for  the  colic  they  were  so  much  subject  to  in  his  time. 
"The  purity  of  the  Claremont  water  becomes  a  most  dangerous  property,  and  not 
only  to  it  but  to  other  springs.  Whilst  I  was  combating  its  pernicious  effects,  1  heard 
that  there  had  been  several  similar  cases  in  different  parts  of  England ;  thev  are  not 
uncommon  in  the  county  of  Surrey,  and  especially  in  the  neighborhood  of  Claremont 
Besides  the  cases  published  by  Dr.  Thompson,  I  know  of  several  others  at  Weybndge, 
Windsor,  and  in  different  other  places.  .      ,    ,  x-x      r 

"  I  should  inform  you  that  Professor  Hoffman  has  ascertained  the  quantity  of  me- 
tallic lead  contained  in  the  water  examined  by  him.  He  has  found  that  it  amounted 
to  a  grain  per  gallon,  an  enormous  quantity  when  we  consider  that  the  poisoiied  water 
was  used  in  all  culinary  and  table  purposes;  and,  previously  to  the  discovery  of  its 
deleterious  character,  even  in  the  preparation  of  ptisans  and  lavements. 

Le\d  Shot  has  been  manufactured  in  the  United  States  in  low  towers,  provided 
with  an  ascending  stream  of  air,  drawn  up  by  a  fan  worked  by  water  power,  whereby 
a  like  cooling  effect  is  obtained  as  by  letting  the  melted  lead  fall  from  a  high  tower. 

LEATHER,  (Cuir,  Fr. ;  Leder,  Germ.);  is  the  skin  of  animals,  so  modified  by  chem- 
ical means  as  to  have  become  unalterable  by  the  external  agents  which  tend  to  de- 
compose it  in  its  natural  state.  The  preparation  in  a  rude  manner  of  this  valuable 
substance  has  been  known  from  the  most  ancient  times,  but  it  was  not  till  the  end  of 
the  last,  and  the  beginning  of  the  present  century,  that  it  began  to  be  manufactured 
upon  right  principles,  in  consequence  of  the  researches  of  Macbride,  Deyeux,  beguin, 
and  Davy.  There  are  several  varieties  of  leather;  such  as  sole  leather,  boot,  or  upper 
leather,  sharaoy  leather,  kid  or  glove  leather,  Ac.  Skins  may  be  converted  into  lea- 
ther either  with  or  without  their  hairy  coat.  *  j  * 
We  shall  treat  first  of  sole  and  upper  leathers,  being  the  most  important,  and  most 


custlv  and  difficult  to  prepare  in  a  proper  manner.  These  kinds  consist  of  organized 
fibrous  gelath^e  or  skin,  cabined  with  the  proximate  vegetable  principle  tannin,  and 
nrobablvalso  some  vegetable  extractive.  Under  the  articles  Galls  and  Tannin  will 
r?ound  an  account  of  Uie  properties  of  this  substance  and  the  means  of  obtaining  it  in  a 
stae  of  purity.  Calf  leather  quickly  tanned  by  an  infusion  of  galls,  consists  of  61  par^s 
f/skin  and  39  of  vegetable  matter  in  100  by  weight;  by  solution  of  catechu  it  consists 
f  80  of  skin  and  20  of  vegetable  matter  ;  by  infusion  of  Leicester  wiUow  of  iA-o  skin, 
nd  25  5  veg^table^^^^^^^^^  by  infusion  of  oak  bark,  of  73-2  skin  and  26-8  vegetable 

matter  By  the  slow  process  of  tannmg,  continued  for  three  months,  the  increase  of 
we  ght' upon  the  skin  in  its  conversion  into  leather,  is  greatly  less;  the  vegetable  consti- 
Sts  being  from  Leicester  wiUow  only  13  per  cent,  of  the  leather,  and  from  oak  bark 
15  T>er  cent.  Sole  leather,  however,  generaUy  contains  no  less  than  40  per  cent,  of  vege- 
rnhle  matter  In  every  astringent  bark,  the  inner  white  part  next  to  the  alburnum,  con- 
^ins  the  largest  quantity  of  tannin,  and  the  middle  colored  part  contains  most  extractive 
matter  The  outer  surface  or  epidermis  seldom  furnishes  either  tannin  or  extractive 
matter'  Youn<'  trees  abound  most  in  the  white  cortical  layers,  and  are  hence  more  pro- 
ductive of  tannin  under  equal  weights,  than  the  barks  of  old  trees.  In  no  case  is  there 
anv  reason  to  beUeve  that  the  gallic  acid  of  astringent  vegetables  is  absorbed  in  l>e  pro- 
cess  of  making  leather;  hence  Seguin's  theory  of  the  agency  of  that  substance  in  disoxy- 
eenatin-  skin,  falls  to  the  ground.  The  different  qualities  of  leather  made  with  the 
same  kind  of  skin,  seem  to  depend  very  much  upon  the  diflerent  quantities  of  extractive 
matter  it  may  have  absorbed.  The  leather  made  with  infusion  of  galls,  is  generaUy 
harder  and  more  liable  to  crack  than  the  leather  obtained  from  infusions  of  barks ;  and 
It  always  contains  a  much  larger  proportion  of  tannin,  and  a  smaller  proportion  of  extrac- 

^^When  calf  skin  is  slowly  tanned  in  weak  solutions  of  the  bark,  or  of  catechu,  it  com- 
bines with  a  good  deal  of  extractive  matter,  and  though  the  increase  of  the  weight  of  the 
skin  be  comparatively  small,  yet  it  has  become  perfectly  insoluble  in  water,  forming  a 
sofl,  but  at  the  same  time  a  strong  leather.  The  saturated  infusions  of  astringent  barks 
contain  much  less  extractive  matter  in  proportion  to  their  tannin,  than  the  weak  infu- 
sions; and  when  skin  is  quickly  tanned  in  the  former,  it  produces  a  worse  and  less 
durable  leather  than  when  slowly  tanned  in  the  latter.  In  quick  tanning,  a  considerable 
quantity  of  vegetable  extractive  matter  is  thus  lost  to  the  manufacturer,  which  might 
have  been  made  to  enter  as  a  useful  constituent  into  the  leather.  These  observations 
show  that  there  is  sufficient  foundation  for  the  opinion  of  the  common  workmen,  con- 
cerning what  is  technicaUy  called  feeding  of  leather,  in  the  slow  method  of  tanning; 
and  though  the  processes  of  this  art  have  been  unnecessarily  protracted  by  defective 
methods  of  steeping,  and  want  of  progressive  infiltration  of  the  astringent  liquor  through 
the  skins,  vet  in  general  they  appear  to  have  arrived,  in  consequence  of  old  experience,  at 
a  degree  of  perfection  in  the  quaUty  of  the  leather,  which  cannot  be  far  exceeded  by 
means  of  any  theoretical  suggestions  which  have  been  advanced.  -      .  , 

On  the  first  view  it  may  appear  surprising,  that  in  those  cases  of  quick  tanning, 
where  extractive  matter  forms  a  certain  portion  of  the  leather,  the  increase  of  weight  is 
less  than  when  the  skin  is  combined  with  the  pure  tannin;  but  the  fact  is  easily  account- 
cd  for,  when  we  consider  that  the  attraction  of  skin  for  tannin  must  be  probably  weak- 
ened by  its  union  with  extractive  matter ;  and  whether  we  suppose  that  the  tannin  and 
extractive  matter  enter  together  into  combination  with  the  matter  of  skin,  or  unite  with 
separate  portions  of  it,  still,  in  either  case,  the  primary  attraction  of  skm  for  tan  must  be 

to  a  certain  extent  diminished. 

In  examining  astringent  vegetables  in  relation  to  their  power  of  making  leather,  it  is 
necessary  to  take  into  account  not  only  the  quantity  they  may  contain  of  the  substance 
precipitable  by  gelatine,  but  likewise  the  quantity  and  the  nature  of  the  extractive  matter ; 
and  in  cases  of  comparison,  it  is  essential  to  employ  infusions  of  the  same  degree  of  con- 
centration. V  1-  •       ♦», 

Of  all  astringent  substances  hitherto  examined,  catechu  is  that  which  contains  the 
laigest  proportion  of  tanning  and  in  supposing,  according  to  the  usual  estimation,  that 
fixim  four  to  five  pounds  of  common  oak  bark  are  required  to  produce  one  pound  of 
leather,  it  appears,  from  the  various  synthetical  experiments,  that  about  half  a  Po«pd  <>» 
catechu  would  answer  the  same  purpose.  Mr.  Purkis  found,  by  the  results  of  different 
accurate  experiments,  that  1  pound  of  catechu  was  equivalent  to  7  or  8  of  oak  bark. 
For  the  common  purposes  of  the  tanner,  1  pound  of  it  would  be  equivalent  also  to  2^ 
pounds  of  ffalls,  to  7|  of  the  Leicester  willow,  to  11  of  the  bark  of  the  Spanish  chestnut, 
to  18  of  the  bark  of  the  common  elm,  to  21  of  the  bark  of  the  common  willow,  and  to  3 
pounds  of  sumach. 

Various  menstrua  have  been  proposed  for  the  purpose  of  expediting  and  improving  the 
process  of  tanning,  among  others,  lime  water,  and  solution  of  pearl-ash ;  but  as  these 
two  substances  form  compounds  with  tannin  which  are  not  decomposable  by  gelatine,  it 

/ 


M 


LEATHER. 


LEATHER. 


67 


I 'I 


H 


follows  that  their  effects  must  be  prejudicial.  There  is  very  little  reason  to  suppose  thai 
any  bodies  will  be  found  which,  at  the  same  time  that  they  increase  the  solubility  of  tan- 
nin in  water,  will  not  likewise  diminish  its  attraction  for  skin. 

In  this  country  all  tanned  leather  is  distinguished  into  two  kinds,  called  hides  and 
skins ;  the  former  term  being  appropriated  to  that  made  from  the  larger  animals,  as 
bulls,  buffaloes,  oxen,  and  cows,  into  thick  strong  sole  leather ;  and  the  latter  to  that 
made  from  calves,  seals,  &c.,  into  thinner  and  more  flexible  upper  leather.  Sometimes 
the  hides  are  brought  into  the  market  merely  dried,  as  from  Buenos  Ayres ;  or  dried  and 
salted,  as  from  Bahia  and  Pernambuco ;  but  the  greater  part  are  fresh  from  recently 
slaughtered  animals.  The  heaviest  ox-hides  are  preferred  for  forming  butts  or  6acfe«, 
which  are  manufactured  as  follows  : — 

The  washing  process  must  be  more  or  less  elaborate,  according  to  the  state  of  the  skins. 
Those  that  are  salted  and  dry  require  to  be  steeped,  beaten,  and  rubbed  several  times  al- 
ternately, to  bring  them  to  the  fresh  condition. 

After  removing  the  horns,  the  softened  or  recent  hides  are  laid  in  a  heap  for  two  or 
three  days,  after  which  they  are  suspended  on  poles  in  a  close  room  called  a  smoke- 
house, heated  somewhat  above  the  common  temperature  by  a  smouldering  fire.  In  these 
circumstances,  a  slight  putrefaction  supervenes,  which  loosens  the  epidermis,  and  renders 
the  hair  easily  detachable  by  the  fleshing  knife ;  a  large  two  handled  implement,  with  a 
blunt  edge,  and  bent  to  suit  the  curvature  of  the  rounded  beam  of  the  wooden  horse  upon 
which  the  hide  is  scraped.    See  Currying. 

The  next  step  is  immersion  in  a  pit  containing  water  impregnated  with  about  a  1000th 
part  of  sulphuric  acid.  This  process  is  called  raising,  because  it  distends  the  pores,  and 
makes  the  fibres  swell,  so  as  to  render  the  skins  more  susceptible  of  the  action  of  the  tan- 
ning infusions.  Forty-eight  hours  in  general  suffice  for  this  operation,  but  more  time  may 
be  safely  taken. 

When  the  hides  are  found  to  be  sufficiently  raised,  they  are  transferred  to  a  pit,  in 
which  they  are  stratified  with  oak  bark,  ground  by  a  proper  mill  into  a  coarse  powder. 
The  pit  is  then  filled  up  with  an  infusion  of  oak  bark  called  ooze,  and  the  hides  are 
allowed  to  remain  in  it  for  about  a  month  or  six  weeks.  By  this  time  the  tannin  and 
extractive  matter  of  the  bark  having  combined  intimately  with  the  animal  fibre,  the 
pit  is  exhausted  of  its  virtue,  and  must  be  renewed,  by  taking  out  the  spent  bark,  and 
subjecting  the  skins  to  a  fresh  dose  of  oak  bark  and  ooze.  The  hides  which  were 
placed  near  the  top  of  the  first  pit,  must  be  placed  near  the  bottom  of  the  next.  In  this 
mixture  they  remain,  upon  the  old  practice,  about  three  months.  The  last  process 
being  repeated  twice  or  thrice,  perfectly  tanned  leather  is  the  result.  The  hides  are  now 
removed  from  the  pit,  and  hung  up  in  a  shed.  In  tha  progress  of  drying,  which  should 
be  slow,  they  are  compressed  with  a  steel  tool,  and  beaten  smooth,  to  render  them  more 
finn  and  dense. 

Some  manufacturers  place  on  the  bottom  of  the  pit  5  or  6  inches  of  spent  bark,  over 
it  2  inches  of  fresh  bark,  then  a  skin  ;  and  so,  alternately,  a  layer  of  new  bark  and  a  skin, 
till  the  pit  is  nearly  full,  reserving  a  small  space  at  top  for  a  thicker  layer  of  bark,  over 
which  weighted  boards  are  laid,  to  condense  the  whole  down  into  the  tanning  infusion. 

The  operation  of  tanning  sole  leather  in  the  above  way,  lasts  a  year  or  a  year  and  a 
half,  according  to  the  quality  wanted,  and  the  nature  of  the  hides. 

A  perfect  leather  is  recognised  by  its  section,  which  should  have  a  glistening  marbled 
appearance,  without  any  white  streaks  in  the  middle. 

Crop  hides  are  manufactured  by  immersion,  during  three  or  four  days,  in  pits  contain- 
ing milk  of  lime ;  in  which  they  are  occasionally  moved  up  and  down  in  order  to  expose 
them  equally  to  the  action  of  this  menstruum.  They  are  then  removed,  and  cleared 
from  hair  and  impurities,  by  usmg  the  fleshing  knife  upon  the  horse ;  after  which  they 
must  be  completely  freed  from  the  lime  by  a  thorough  washing.  They  are  next 
plunged  in  pits  containing  a  weak  ooze  or  infusion  of  oak  bark,  from  which  they  arc 
successively  transferred  into  other  pits  with  stronger  ooze ;  all  the  while  being  daily 
handled,  that  is,  moved  up  and  down  in  the  infusion.  This  practice  is  continued  for 
about  a  month  or  six  weeks.  They  are  now  ready  to  be  subjected  to  a  mixture  of  ground 
oak  bark  and  stronger  ooze  in  other  pits,  to  a  series  of  which  they  are  progressively  sub- 
jected during  two  or  three  months. 

The  hides  are  next  put  into  large  vats,  called  layers,  in  which  they  are  smoothly  strati- 
fied with  more  oak  bark,  and  a  stronger  infusion  of  it.  After  six  weeks  they  are  taken 
out  of  these  vats,  and  subjected  to  a  new  charge  of  the  same  materials  for  two  months. 
This  simple  process  is  repeated  twice  or  thrice,  at  the  option  of  the  manufacturer,  till 
the  hides  are  thoroughly  tanned.  They  are  then  slowly  dried,  and  condensed  in  the  man- 
ner above  described.  These  crop  hides  form  the  principal  part  of  the  sole  leather  used 
for  home  consumption  in  England. 

The  process  of  tanning  skins  (as  of  calves,  seals,  &c.)  is  in  some  respects  peculiar. 
They  are  left  in  the  lime  pits  for  about  twelve  days,  when  they  are  stripped  of  their 


hair  washed  in  water,  then  immersed  in  a  lixivium  of  pigeons*  dung,  called  a  grainer,  of 
an  a\kaline  nature.  Here  they  remain  from  eight  to  ten  days,  according  to  the  state  of 
the  atmosphere,  during  which  time  they  are  frequently  handled,  and  scraped  on  both 
sides  upon  a  convex  wooden  beam.  This  scraping  or  xoorking,  as  it  is  termed,  joined  to 
the  action  of  the  grainer,  serves  to  separate  the  lime,  oil,  and  glutinous  matter,  and  to 
render  the  skin  pliant,  soft,  and  ready  to  imbibe  the  tanning  principle.  They  are  with 
this  view  transferred  into  pits  containing  a  weak  solution  of  bark,  in  which  they  undei^o 
nearly  the  same  treatment  as  described  above  for  crop  hides ;  but  they  are  not  com- 
monly stratified  in  the  layers.  The  time  occupied  in  tanning  them  is  usually  limited 
to  three  months.  They  are  then  dried,  and  disposed  of  to  the  currier,  who  dresses  and 
blackens  them  for  the  upper  leathers  of  boots  and  shoes,  for  harness,  and  other 
purposes.     The  light  and  thin  sorts  of  cow  and  horse  hides  are  often  treated  like  calf 

skins. 

In  all  the  above  processes,  as  the  animal  fibres  on  the  surface  of  the  skin  absorb  most 
readily  the  tanning  principles,  and  thereby  obstruct,  in  a  certain  degree,  their  passage 
into  the  interior  fibres,  especially  of  thick  hides,  it  becomes  an  object  of  importance  to 
contrive  some  method  of  overcoming  that  obstacle,  and  promoting  the  penetration  of 
the  tan.  The  first  manufacturer  who  appears  to  have  employed  efficacious  mechaniad 
means  of  favoring  the  chemical  action  was  Francis  G.  Spilsburj',  who  in  April,  1823, 
obtained  a  patent  for  the  following  operation: — After  the  hides  are  freed  from  the 
hairs,  &c.  in  the  usual  way,  they  are  minutely  inspected  as  to  their  soundness,  and  if 
any  holes  be  found,  they  are  carefully  sewed  up,  so  as  to  be  water  tight.  Three  frames 
of  wood  are  provided  of  equal  dimensions,  fitted  to  each  other,  with  the  edges  of 
the  frames  held  together  by  screw  bolts.  A  skin  about  to  be  tanned  is  now  laid  upon 
the  frame,  and  stretched  over  its  edges,  then  the  second  frame  is  to  be  placed  upon 
it,  so  that  the  edges  of  the  two  frames  may  pinch  the  skin  all  round  and  hold  it  securely ; 
another  such  skin  is  then  stretched  over  the  upper  surface  of  the  second  frame,  in  like 
manner,  and  a  third  frame  being  set  upon  this,  confines  the  second  skin.  The  three 
frames  are  then  pinched  tightly  together  by  a  series  of  screw  bolts,  passing  through  ears 
set  round  their  outer  edges,  which  fix  the  skin  in  a  proper  manner  for  being  operated  upon 
by  the  tanning  liquor. 

A  space  has  been  thus  formed  between  the  two  skins,  into  which,  when  the  frames 
are  set  upright,  the  infusion  is  introduced  by  means  of  a  pipe  from  the  cistern  above, 
while  the  air  is  permitted  to  escape  by  a  stopcock  below.  This  cock  must  of  course  be 
shut  whenever  the  bag  is  filled,  but  the  one  above  is  left  open  to  maintain  a  communica- 
tion with  the  liquor  cistern,  and  to  allow  the  hydrostatic  pressure  to  force  the  liquoi 
throush  the  cutaneous  pores  by  a  slow  infiltration,  and  thus  to  bring  the  tannin  into  con- 
tact with  all  the  fibres  indiscriminately.  The  action  of  this  pressure  is  evinced  by  a  con- 
stant perspiration  on  the  outer  surfaces  of  the  skins. 

When  the  tanning  is  completed,  the  upper  stopcock  is  closed,  and  the  under  is  opened 
to  run  off  the  liquor.  The  frames  are  now  removed,  the  bolts  are  unscrewed,  and  the 
pinched  edges  of  the  skins  pared  off;  after  which  they  are  to  be  dried  and  finished  in  the 
usual  manner. 

A  modification  of  this  ingenious  and  effectual  process  was  made  the  subject  of  a 
patent,  by  William  Drake,  of  Bedminster,  tanner,  in  October,  1831.  The  hides,  after 
the  usual  preparatory  processes,  are  immersed  in  a  weak  tan  liquor,  and  by  frequent 
handling  or  turning  over,  receive  an  incipient  tanning  before  being  submitted  to  the 
infiltration  plan.  Two  hides,  as  nearly  of  the  same  size  and  shape  as  possible,  are  placed 
grain  to  grain,  when  their  corresponding  edges  are  sewed  firmly  together  all  round 
by  shoemakers*  waxed  thread,  so  as  to  form  a  bag  sufficiently  tight  to  hold  tan  liquor. 
This  bag  must  then  be  suspended  by  means  of  loops  sewed  to  its  shoulder  end,  upon 
pegs,  in  such  a  manner  that  it  may  hang  within  a  wooden-barred  rack,  and  be  confined 
laterally  into  a  book  form.  About  an  inch  of  the  bag  is  left  unsewed  at  the  upper  end, 
for  the  purpose  of  introducing  a  funnel  through  which  the  cold  tan  liquor  is  pourel  into 
the  bag  till  it  be  full.  After  a  certain  interval  which  varies  with  the  quality  of  the  hides, 
the  outer  surface  becomes  moist,  and  drops  begin  to  form  at  the  bottom  of  the  bag.  These 
arc  received  in  a  proper  vessel,  and  when  they  accumulate  sufficiently  may  be  7>oured 
back  into  the  funnel ;  the  bag  being  thus,  as  well  as  by  a  fresh  supply  from  above,  kept 
constantly  distended. 

When  the  hides  are  observed  to  feel  hard  and  firm,  while  every  part  of  them  feels 
equally  damp,  the  air  of  the  tanning  apartment  having  been  always  well  ventilated,  is 
now  to  be  heated  by  proper  means  to  a  temperature  gradually  inereasing  from  70** 
to  150°  of  Fahrenheit's  scale.  This  heat  is  to  be  maintained  till  the  hides  become 
fiiiner  and  harder  in  all  parts.  When  they  begin  to  assume  a  black  appearance  in  some 
parts,  and  when  the  tan  liquor  undergoes  little  diminution,  the  hides  may  be  considered 
to  be  tanned,  aud  the  bag  may  b^  emptied  by  cutting  a  few  stitches  at  its  bottom. 
iTie  outer  e-iges  being  pared  off,  the  hides  are  lo  be  finished  in  the  usual  way.    During 


58 


LEATHER. 


Uquor!  ^°™tion  of  furrows  by  the  bars,  and  to  facUilale  the  equable  action  of  the 

aJI  ^^-^  P""*;? f  '^^  patentee  says,  that  a  hide  may  be  tanned  as  completely  in  ten 
days  as  it  could  be  in  ten  months  by  the  usual  method.     I  have  seen  a  piece  of  so  e  leather 
thus  rapidly  tanned,  and  it  seemed  to  be  perfect.    How  it  may  wear,  clparerwi  ^th^ 
made  in  the  old  way,  I  cannot  pretend  to  determine.  '  comparea  with  that 

Messrs.  Knowlys  and  Duesbury  obtained  a  patent  in  Au^st,  1826,  for  accelerating 
the  impiegnation  of  skins  with  tannin,  by  suspending  them  in  a  close  vessel,  fmm  which 
the  air  is  to  be  extracted  by  an  air  pump,  and  then  the  tanning  infusion  is  to  be  admU.S^ 
Ihortlimf'      '"  '"PP«^^^  t«  penetrate  the  hide  so  effectually  as  to  tan  it  uniformly  in  a 

About  32  years  ago,  a  similar  vacuum  scheme  was  employed  to  impre«Tiate  with 
^rR^^sJ'TkZClt''  '^"  ''^'  '^ '"""''  ''""'  ^"'  '^'  ^""^^  loomsof  Messrs.  Raddiff 

Danish  leather  is  made  by  tanning  lamb  and  kid  skins  with  willow  bark,  whence  it  de^ 
nves  an  agreeable  smell.    It  is  chiefly  worked  up  into  gloves. 

0/ihe  tawing  or  dressing  of  skins  for  gloves,  and  white  sheep  leather. 

lirn^^^'^fT'^^'^^J^'fl' ""'^  *'!  =  1.  washing  the  skins;  2.  properly  treating  them  with 
lime ;  3.  taking  off  the  fleece ;  4.  treatment  in  the  leather  steep. 

Ashed  erected  upon  the  side  of  a  stream,  with  a  cistern  of  water  for  washing  the 
skins;  wooden  horses  for  ceaning  them  with  the  back  of  the  fleshing  knife;  pincers 
for  removmg  the  fibres  of  damaged  wool;  a  plunger  for  depressing  the  skin's  Tnth" 
pits  ;  a  hme  pit ;  a  pole  with  a  bag  tied  to  the  end  of  it ;  a  two-handed  fleshing  knife  • 
ntln^ir^  r;  •""  ^^  /"Ir  V""^"'  ^Si-  thickened  in  the  middle;  such  are  somi  of  the 
nU^nt  V- ""?  fstabhshment.  There  must  be  provided  also  a  table  for  applying  the 
oil  to  the  skins;  a  fulling  mill,  worked  by  a  water-wheel  or  other  power;  a dressin- pe- • 
a  press  for  squeezing  out  the  fatty  filth ;  a  stove ;  planks  mounted  upon  legs,  for  sfretchl 

Fresh  skins  must  be  worked  immediately  after  being  washed,  and  then  dried  other- 
wise  they  ferment,  and  contract  either  indelible  spots,  or  get  tender  in  certain  points  ^o 
as  to  open  up  and  tear  under  the  tools.  When  received  in  the  dry  state  they  should 
be  steeped  in  water  for  two  days,  and  then  treated  as  fresh  skins.  They  are  next  stron^^lv 
rubbed  on  the  convex  horse-beam  with  a  round-edged  knife,  in  order  to  make  them  nli- 
ant.  The  rough  parts  are  removed  by  the  fleshing  knife.  One  workman  can  in  this  way 
prepare  200  skins  in  a  day.  ««  wajr 

The  flesh  side  of  each  being  rubbed  with  a  cold  cream  of  lime,  the  skins  are  piled 
together  with  the  woolly  side  of  each  pair  outermost,  and  the  flesh  sides  in  contact. 
They  are  left  m  this  state  for  a  few  days,  tiU  it  is  found  that  the  wool  may  be  easUy  re- 
moved by  ;j/ttcfciwg.  '  asuj'  IC 

They  are  next  \yashed  in  running  water,  to  separate  the  greater  part  of  the  lime 
stripped  of  the  wool  by  small  spring  tweezers,  and  then  fleeced  smooth  by  means  of  the 
rollmg-pm,  or  sometimes  by  rubbing  with  a  whetstone.     Unless  they  be  fleeced  soon 
after  the  treatment  with  lime,  they  do  uot  well  admit  of  Uiis  operation  subsequently,  as 
they  are  apt  to  get  hard.  h         j>  «w 

They  are  now  steeped  in  the  milk  of  lime-pit,  in  order  to  swell,  soften,  and  cleanse 
them;  afterwards  ma  weak  pit  of  ol.l  lime-water,  from  which  they  are  taken  out  and 
clramed.  fnis  steeping  and  draining  upon  inclined  tables,  are  repeated  frequently  durin^ 
the  space  of  3  weeks.  Only  the  skins  of  young  animals,  or  those  of  inferior  value  are 
tawed.     Sometimes  the  wool  is  left  on,  as  for  housings,  &c. 

The  skins,  after  having  been  well  softened  in  the  steeps,  are  rubbed  on  the  outside 
with  a  whetstone  set  m  a  wooden  case  with  two  handles,  in  order  to  smooth  them 
completely  by  removing  any  remaining  filaments  of  wool.     Lamb  skins  are  rubbed 
with  the  pin  in  the  direction  of  their  breadth,  to  give  them  suppleness ;  but  sheep  skina 
are  fuUed  with  water  a.one.     They  are  now  ready  for  the  brannivg,  which  is  done  bv 
mixing  40  lbs.  of  bran  with  20  gallons  of  water,  and  keeping  them  in  this  fermentable 
mature  for  throe  weeks— with  the  addition,  if  possible,  of  some  old  bran  water     Hero 
they  must  te  frequently  turned  over,  and  carefully  watched,  as  it  is  a  delicate  op'eration 
In  the  course  of  two  days  in  summer,  and  eight  in  winter,  the  skins  are  said  to  be* 
raised,  when  they  sink  in  the  water.      On  coming  out  of  the  bran,  they  are  ready 
for  the  whii'.e  stufi ;  which  is  a  bath  composed  of  alum  and  sea-salt.     Twelve  fourteenl 
and  sometmies  eighteen  pounds  of  aJnm  for  100  skins,  form  the  basis  of  the  bath  •  to 
which  two  and  a  half  pounds  of  salt  are  added  in  winter,  and  three  in  summer      These 
ingredients  are  introduced  into  a  copper  with  twelve  gallons  ol  water     The  salt  aids 
m  the  whitening  action.    When  the  solution  is  about  to  boil,  three  gallons  of  it  are 


LEATHER. 


69 


passed  through  the  cullender  into  a  basin  ;  in  this  26  skins  are  worked  one  after  another, 
and,  after  draining,  they  are  put  together  into  the  bath,  and  left  in  it  for  ten  minutes  to 
imbibe  the  salts.  They  are  now  ready  to  receive  the  paste.  For  100  skins,  from  13  to 
15  pounds  of  wheat  flour  are  used  along  with  the  yolks  of  50  eggs.  After  having  warmed 
the  alum  bath  through  which  the  skins  have  been  passed,  the  flower  is  dusted  into  it, 
with  careful  stirring.  The  paste  is  well  kneaded  by  the  gradual  addition  of  the  solution, 
and  passed  through  the  cullender,  whereby  it  becomes  as  cleur  as  honey.  To  this  the 
yolks  being  added,  the  whole  is  incorporated  with  much  manual  labor.  The  skins  are 
worked  one  after  another  in  this  paste  ;  and  afterwards  the  whole  together  are  left  im- 
mersed in  it  for  a  day.  They  are  now  stretched  and  dried  upon  poles,  in  a  proper  apart- 
ment, during  from  8  to  15  days,  according  to  the  season. 

The  effects  of  the  paste  are  to  whiten  the  skins,  to  soften  them,  and  to  protect  them 
from  the  hardening  influence  of  the  atmosphere,  which  would  naturally  render  them 
brittle.  They  would  not  bear  working  upon  the  softening  iron,  but  for  the  emulsion 
which  has  been  introduced  into  their  substance.  With  this  view  they  are  dipped  in  a  tub 
of  clear  water  during  five  or  six  minutes,  and  then  spread  and  worked  upon  the  board. 
They  are  increased  by  this  means  in  length,  in  the  proportion  of  5  to  3.  No  hard  points 
must  be  left  in  them.  The  whiteness  is  also  better  brought  out  by  this  operation,  which 
is  performed  upon  the  flesh  side.  The  softening  tool  is  an  iron  plate,  about  one  foot 
broad,  rounded  over  above,  mounted  upon  an  upright  beam,  30  inches  high,  which 
is  fixed  to  the  end  of  a  strong  horizontal  plank,  3^  feet  long,  and  1  broad.  This  plank 
is  heavily  loaded,  to  make  it  immoveable  upon  the  floor.  Sometimes  the  skins  arc  next 
spread  over  an  undressed  clean  skin  upon  the  horse,  and  worked  well  with  the  two-handled 
knife,  for  the  purpose  of  removing  the  first  and  second  epidermis,  called  the  feur  and 
arriere-Jleur  by  the  French  megissiers.  They  are  then  dried  while  stretched  by  hooks  and 
strings.  When  dry  they  are  worked  on  the  stretching  iron,  or  they  are  occasionally  pol- 
ished with  pumice  stone.  A  delicate  yellow  lint  is  given  by  a  composition  made  of  two 
parts  of  whitening,  and  one  of  ochre,  applied  in  a  moistened  state,  and  well  worked  in 
upon  the  grain  side.  After  being  polished  with  pumice,  they  are  smoothed  with  a  hot 
iron,  as  the  laundresses  do  linen,  whereby  they  acquire  a  degree  of  lustre,  and  are  ready 
to  be  delivered  to  the  glover. 

For  housings,  the  best  sheepskins  are  selected,  and  such  as  are  covered  with  the  lonsrest 
and  most  beautiful  fleece.  They  are  steeped  in  water,  in  order  to  be  cleansed  and  soft- 
ened ;  after  which  they  are  thinned  in?ide  by  the  fleshing  knife.  They  are  now  steeped 
in  an  old  bran  pit  for  3  or  4  days,  when  they  are  taken  out  and  washed.  They  arc  next 
subjected  to  the  white  or  alum  bath,  the  wool  being  carefully  folded  within ;  about  18 
pounds  of  alum  being  used  for  100  skins.  The  paste  is  made  as  for  the  fleeced  skins,  but 
it  IS  merely  spread  upon  their  flesh  side,  and  left  upon  them  for  18  hours,  so  as  to  stiffen. 
They  are  then  hung  up  to  dry.  They  are  next  moistened  by  sprinkling  cold  water 
upon  them,  folded  up,  piled  in  a  heap,  and  covered  with  boards  weighted  with  heavy 
Stones ;  in  which  state  they  remain  for  two  days.  They  are  next  opened  with  a  round 
iron  upon  the  horse,  and  subjected  to  the  stretching  iron,  being  worked  broadwise.  They 
are  dried  with  the  fleece  outermost,  in  the  sun  if  possible ;  and  are  finished  upon  the 
stretcher. 

Calf  and  lamb  skins  with  their  hair  and  wool  are  worked  nearly  in  the  same  manner ; 
only  the  thicker  the  skin,  the  stronger  the  alum  bath  ought  to  be.  One  pound  of  alum 
and  one  of  salt  are  required  for  a  single  calf  skin.  It  is  left  four  days  in  this  bath,  after 
which  it  is  worked  upon  the  stretcher,  then  fulled  ;  when  half  dry  the  skins  are  opened 
r.pon  the  horse.  In  eight  days  of  ordinary  weather,  they  may  be  completely  dressed. 
Lamb  skins  are  sometimes  steeped  during  eight  days  in  a  bath  prepared  with  unbolted 
rye  flour  and  cold  water,  in  which  they  are  daily  moved  about  two  or  three  times. 
They  are  then  dried,  sti  stched  upon  the  iron,  and  switched  upon  the  fleecy  side. 

Chamois  cr  Shamoy  leather.— The  skins  are  first  washed,  limed,  fleeced,  and  branned 
as  above  described.  They  are  next  efflowered,  that  is,  deprived  of  their  epidermis  by  a 
concave  knife,  blunt  in  its  middle  part,  upon  the  convex  horse-beam.  The  cutting  part 
sirves  to  remove  all  excrescences,  and  to  equalize  the  thickness,  while  the  blunt  part 
softens  and  smooths.  The  skins  of  goats,  does,  and  chamois,  are  always  treated  in  this 
way.  1  hey  are  next  subjected  to  the  fermenting  bran  steep  for  one  or  two  davs,  in 
ordiivary  weather ;  but  in  hot  weather  for  a  much  shorter  time,  sometimes  only  moving 
them  m  the  sour  bran  liquor  for  a  few  minutes.  Thev  are  lastly  wrung  at  the  peg,  and 
subjected  to  the  lulling  mill.  ' 

When  the  skins  have  been  sufficiently  swelled  and  suppled  by  the  branning,  they  may 
receive  the  hrst  oil  as  follows  :  a  dozen  skins  being  stretched  upon  the  table;  the  fingers 
are  dipped  m  the  oil  and  shaken  over  the  skins  in  different  places,  so  as  to  imi>art 
enough  of  It  to  imbue  the  whole  surface  slightly,  by  friction  with  the  palms  of  the 
nands.  It  is  to  the  outside  or  grain  that  the  oil  is  applied.  The  skins  are  folded  four 
together,  so  as  to  form  balls  of  the  size  of  a  hog's  bladder,  and  thrown  into  the  .trough 


11 


60 


LEATHER. 


P  |i! 


■I  ! 


of  the  fulling  miU,  to  the  number  of  tvelve  dozen  at  once.  Here  they  remain  exposed 
to  the  heater  for  two,  three,  or  four  hours,  according  to  their  nature  and  the  state  of  the 
weather.  They  are  taken  out,  aired,  oiled,  and  again  fulled.  The  airing  and  fulling 
are  repeated  several  times,  with  more  or  less  frequent  oilings.  Any  cheap  animal  oil  is 
employed. 

After  these  operations,  the  skins  require  to  be  subjected  to  a  fermenting  process,  to  dilate 
their  pores  and  to  facilitate  iheir  combination  with  the  oil.  This  is  perfoimed  in  a  cham- 
ber  only  6  feet  high,  and  10  or  12  feet  square.  Poles  are  suspended  horizontally  a  few 
inches  from  the  ceiling,  with  hooks  fixed  in  them  to  which  the  skins  are  attached  A 
somewhat  elevated  temperature  is  maintained,  and  by  a  stove  if  need  be.  This  onera- 
tion  requires  great  skill  and  experience. 

The  remainder  of  the  epidermis  is  next  removed  by  a  blunt  concave  knife  and  the 
horse ;  whereby  the  surface  is  not  cut,  but  rather  forcibly  scraped. 

The  skins  are  now  scoured  to  carry  off  the  redundant  oil ;  which  is  effected  by  a  pot- 
ash ley,  at  two  degrees  Baume,  heated  no  hotter  than  the  hand  can  bear.  In  this  they  are 
stirred  briskly,  steeped  for  an  hour,  and  lastly  wrung  at  the  peg.  The  soapy  liquor  thus 
expelled  is  used  for  inferior  purposes.  The  clean  skins,  after  being  dried,  are  finished 
nrst  on  the  stretcher-iron,  and  then  on  the  herse  or  stretching  frame. 

Leather  of  Huvgary.— This  is  manufactured  by  impregnating  strong  hides  with  alum 
common  salt,  and  suet ;  by  a  rapid  process  which  is  usually  completed  in  the  space  of 
two  months.      The  workshop  is  divided  into  two  parts  :  1.  A  shed  on  the  side  of  a 
stream,  furnished  with  wooden  horses,  fleshing  knives,  and  other  small  tools.     In  one 
corner  is  a  furnace  with  a  boiler  for  dissolving  the  alum,  a  vat  for  immersing  the  hides 
in  the  solution,  and  several  subsidiary  tubs.     2.  A  chamber,  6  feet  high,  by  15  feet 
square,  capable  of  being  made  very  tight,  for  preser%in?  the  heat.     In  one  corner  is  a 
copper  boiler,  of  sufficient  size  to  contain  170  pounds  of  tallow.      In  the  middle  of  the 
stoyeisasquarestoneslab,  upon  which  an  iron  grate  is  placed  about  a  vard  square 
This  is  covered  with  charcoal.     At  each  side  of  the  stove  are  large  tables,  which  occupy 
its  wliole  length,  and  on  which  the  leather  is  spread  to  receive  the  g'-ease.     The  upper 
part  below  the  ceiling  is  filled  with  poles  for  hanging  the  leather  upon  to  be  heated 
ihc  door  is  made  to  shut  perfectly  close. 

The  first  operations  are  analogous  to  those  of  tanning  and  tawing ;  the  skins  beine 
washed,  cut  m  halves,  shaved,  and  steeped  for  24  hours  in  the  river.  They  are  then 
cleaned  with  5  or  6  pounds  of  alum,  and  3^  pounds  of  salt,  for  a  piece  of  hide  which 
weighs  from  70  to  80  pounds.  The  common  salt  softens  the  effect  of  the  alum  attracts 
the  moisture  of  the  air,  and  preserves  the  suppleness  of  the  skin.  When  the  alum  and 
salt  are  dissolved,  hot  water  is  poured  upon  the  hides  placed  in  a  vat,  and  they  are  tramped 
upon  by  a  workman  walking  repeatedly  from  one  end  of  the  vat  to  the  other.  They  are 
tlhen  transferred  into  a  similar  vat  containing  some  hot  water,  and  similarly  tramped  upon 
lliey  are  next  steeped  for  eight  days  in  alum  water.  The  same  round  of  operations  is 
repeated  a  second  time. 

The  skins  are  now  dried  either  in  the  air,  or  a  stove  room ;  but  before  being  quite  dry 
they  are  doubled  together,  well  stretched  to  take  out  the  wrinkles,  and  piled  up.     When 
dry,  they  are  again  tramped  to  open  the  pores  as  well  as  to  render  the  skin  pliant,  after 
which  they  are  whitened  by  exposure  to  the  sun. 

Tallow  of  inferior  quality  is  employed  for  greasing  the  leather.  With  this  view  the 
hides  are  hung  upon  the  poles  in  the  close  stove  room,  then  laid  upon  the  table  and  be- 
smeared with  the  tallow  melted  tUl  it  begins  to  crackle.  This  piece  is  laid  on  another 
table,  is  there  covered  with  a  second,  similariy  greased,  and  so  forth.  Three  pounds  of 
fat  are  commonly  employed  for  one  piece  of  leather. 

When  the  thirty  strips,  or  fifteen  hides  passed  through  the  grease  in  one  operation 
are  completed,  two  workmen  take  the  first  piece  in  their  hands,  and  stretch  it  over  the 
burning  charcoal  on  the  grate  for  a  minute,  with  the  flesh  side  to  the  fire.  The  rest 
are  passed  over  the  flame  in  like  manner.  After  flaming,  the  pieces  are  successively 
laid  on  an  inclined  table  exposed  to  the  fire,  where  thev  are  covered  with  a  cloth.  They 
are  finally  hung  upon  poles  in  the  air  to  dry ;  and  if  the  weather  be  warm,  they  are 
suspended  only  during  the  night,  so  as  to  favor  the  hardening  of  the  grease.  Instead 
of  the  alum  bath,  M.  Curaudau  has  employed  with  advantage  a  steep  of  dilute  sulphuric 

&C1Q* 

Rusxia  leather. — The  Russians  have  long  been  possessed  of  a  method  of  making  a 
peculiar  leather  called  by  them  jucten,  dyed  red  with  the  aromatic  saunders  wood. 
This  article  has  been  much  sought  after,  on  account  of  not  being  subject  to  mould  in 
damp  situations,  being  proof  against  insects,  and  even  repelling  them  from  the  vicinity 
of  Its  odor.  The  skins  are  freed  from  the  hair  or  fleece,  by  steeping  in  an  ash-lye  too 
weak  to  act  upon  the  animal  fibres.  They  are  then  rinsed,  fulled  for  a  longer  or  shorter 
time  according  to  their  nature,  and  fermented  in  a  proper  steep,  after  having  been 
washed  m  hot  water.     They  are  taken  out  at  the  end  of  a  week,  but  they  may  be  steeped 


LEATHER. 


61 


a  second  time  if  deemed  necessary,  to  open  their  pores.     They  are  now  cleaned  by 
working  them  at  the  horse  on  both  the  flesh  and  grain  sides 

A  paste  is  next  composed,  for  200  skins,  of  38  pounds  of  rye  flour,  which  is  set  to 
ferment  with  leaven.  This  dough  is  worked  up  with  a  sufficient  quantity  of  water  to 
form  a  bath  for  the  skins,  in  which  they  are  soaked  for  48  hours  ;  they  aie  then  trans- 
ferred into  small  tubs,  where  they  remain  during  fifteen  days,  after  which  they  are  washed 
at  the  river.  These  operations  serve  to  prepare  the  skins  for  absorbing  the  astringent 
juices  with  uniformity.  A  decoction  of  willow  bark  {salix  cinerea  and  salix  caprea)  be- 
mg  made,  the  skins  are  immersed  in  the  boiler  whenever  the  temperature  of  the  Uquor  is 
sufficiently  lowered  not  to  injure  the  animal  fibres,  and  handled  and  pressed  for  half  an 
hour.  This  manipulation  is  repeated  twice  daily  during  the  period  of  a  week.  The 
tanning  infusion  is  then  renewed,  and  applied  to  the  same  skins  for  another  week ;  after 
which,  being  exposed  to  the  air  to  dry,  they  are  ready  for  being  dyed,  and  then  curried 
with  the  empyreumatic  oil  of  the  bark  of  the  birch  tree.  To  this  substance  the  Russia 
leather  owes  its  peculiarities.  Many  modes  have  been  prescribed  for  preparing  it ;  but 
the  following  is  the  one  practised  in  Russia. 

The  whitish  membranous  epidermis  of  the  birch,  stripped  of  all  woody  parts,  is  intro- 
duced into  an  iron  boUer,  whicii,  when  stuffed  full,  is  covered  tight  with  a  vaulted  iron  lid, 
having  a  pipe  rising  from  its  centre.  A  second  boUer  into  which  this  pipe  passes  without 
reaching  its  bottom,  is  set  over  the  first,  and  is  luted  lo  it  at  the  edges,  after  the  two  are 
bolted  together.  They  are  then  inverted,  so  that  the  upper  one  contains  the  birch  bark. 
The  under  half  of  this  apparatus  is  sunk  in  the  earth,  the  surface  of  the  upper  boiler  is 
coated  over  with  a  clay  lute,  then  surrounded  with  a  fire  of  wood,  and  exposed  to  a  red 
heat,  till  the  distillation  be  completed.  This  operation,  though  rude  in  appearance,  and 
wasteful  of  wood,  answers  its  purpose  perfectly  well.  The  iron  cylinder  apparatus  used 
in  Britain  for  distilling  wood  vinegar,  would,  however,  be  much  more  convenient  and  pro- 
ductive. When  the  above  boilers  are  unluted,  there  is  found  in  the  upper  one  a  very  light 
powder  of  charcoal,  and  in  the  under  one  which  served  as  a  receiver,  there  is  an  oily, 
brown,  empyreumatic  fluid,  of  a  very  strong  smell,  which  is  mixed  with  the  tar,  and  which 
floats  over  a  small  quantity  of  crude  vinegar.  The  former  matter  is  the  oU  employed  to 
impregnate  the  skins,  by  working  it  into  the  flesh  side  with  the  currier's  tools.  It  is  diffi- 
cult to  make  this  oil  penetrate  with  uniformity ;  and  the  Russians  do  not  always  succeed 
m  this  process,  for  they  turn  out  many  skins  in  a  spotted  state.  This  oil  is  at  present 
obtained  in  France  by  distilling  the  birch  bark  in  coppei  stills,  and  condensing  the  pro- 
ducts by  means  of  a  pipe  plunged  in  cold  water.  About  60  per  cent,  of  the  weight  of 
the  bark  is  extracted. 

The  skins  unbibe  this  oil  most  equally  before  they  are  fully  dry.  Care  must  be  taken 
not  to  apply  too  much  of  it,  for  fear  of  its  passing  through  and  staining  the  grain  side  of 
the  leather.  Chevreul  has  investigated  the  chemical  nature  of  this  odoriferous  substance, 
and  finding  it  to  be  a  peculiar  compound,  has  called  it  betuline. 

In  the  Franklin  Institute  for  February,  1843,  Mr.  Gideon  Lee  has  published  some  ju- 
dicious observations  on  the  process  of  tanning.  He  believes  that  much  of  the  original 
gelatine  of  the  hides  is  never  combined  with  the  tannin,  but  is  wasted ;  for  he  thinks 
that  100  lbs.  of  perfectly  dry  hide,  when  cleaned  from  extraneous  matter,  should,  on 
chemical  principles,  afford  at  least  180  lbs.  of  leather.  The  usual  preparation  of  the 
hide  for  tanning  he  believes  to  be  a  wasteful  process.  In  the  liming  and  bating,  or 
the  unhairing  and  the  cleansing,  the  general  plan  is  first  to  steep  the  hides  in  milk  of 
lime  for  one,  two,  or  three  weeks,  according  to  the  weather  and  texture  of  the  skin, 
until  the  hair  and  epidermis  be  so  loosened  as  to  be  readily  removed  by  rubbing  down, 
by  means  of  a  knife,  upon  a  beam  or  block.  Another  mode  is  to  suspend  the  hides  in 
a  close  chamber,  heated  slightly  by  a  smouldering  fire,  till  the  epidermis  gets  loosened 
by  incipient  putrefaction.  A  third  process,  called  sweating,  used  in  Germany,  consists 
in  laying  the  hides  in  a  pack  or  pile,  covered  with  tan,  to  promote  fermentative  heat, 
and  to  loosen  the  epidermis  and  hairs.  These  plans,  especially  the  two  latter,  are  apt 
to  injure  the  quality  of  the  hides. 

The  bate,  consists  in  steeping  the  haired  hides  in  a  solution  of  pigeon's  dung,  con- 
taining, Mr.  Lee  saj^s,  muriate  of  ammonia,  muriate  of  soda,  Ac. ;  but  most  probably 
phosphates  of  ammonia  and  lime,  with  urate  of  ammonia,  and  very  fermentable  animal 
matter.  The  dry  hides  are  often  subjected  first  of  all  to  the  operation  of  the  fulling- 
stocks,  which  opens  the  pores,  but  at  the  same  time  prepares  them  for  the  action  of  the 
liming  and  bate ;  as  also  for  the  introduction  of  the  tanning  matter.  When  the  full- 
ing is  too  violent,  the  leather  is  apt  to  be  too  limber  and  thin.  Mr.  Lee  conceives 
that  the  liming  is  injurious,  by  carrying  off  more  or  less  of  the  gelatine  and  albumen 
of  the  skin.  High-limed  leather  is'loose,  weighs  light,  and  wears  out  quickly.  The 
subsequent  fermentation  in  the  bating  aggravates  that  evil.  Another  process  has  there- 
fore been  adopted  in  New  York,  Maine,  New  Hampshire,  and  some  parts  of  Philadel- 
phia, called,  but  incorrectly,  cool  sweating,  which  consists  in  suspending  the  hides  in  a 


62 


LEATHER. 


(   i 


subterranean  vault,  in  a  temperature  of  50°  Fahr.,  kept  perfectly  damp,  by  the  tricks 
ling  of  cold  spring  water  from  points  in  the  roof.  The  hides  being  first  soaked,  are  sus- 
pended in  this  vault  from  6  to  12  days,  when  the  hair  is  well  loosened,  by  the  mere 
softening  effect  of  moisture,  without  fermentation. 

LEATHER,  MOROCCO.  {Maroquin,  Fr. ;  Saffian,  Germ.)  Morocco  leather  of 
the  finer  quality  is  made  from  goatskins  tanned  with  sumach  ;  inferior  morocco  leather 
from  sheepskins.  The  goatskins  as  imported  are  covered  with  hair ;  to  remove  which 
they  are  soaked  in  water  for  a  certain  time,  and  they  are  then  subjected  to  the  operation 
called  breaking,  which  consists  in  scraping  them  clean  and  smooth  on  the  flesh  side, 
and  they  aje  next  steeped  in  lime-pits  (milk  of  lime)  for  several  days,  during  which 
period  they  are  drawn  oxU,  with  a  hook,  from  time  to  time,  laid  on  the  side  of  the  pit  to 
drain,  and  replunged  alternately,  adding  occasionally  a  little  lime,  whereby  they  are 
eventually  deprived  of  their  hair.  When  this  has  become  sufficiently  loose,  the  skins  are 
taken  out  one  by  one,  laid  on  convex  beams,  the  work-benches,  which  stand  in  an  inclined 
position,  resting  on  a  stool  at  their  upper  end,  at  a  height  convenient  for  tlfe  workman's 
breast,  who  scrapes  off  the  hair  with  a  concave  steel  blade  or  knife,  having  a  handle  at 
each  end.  When  unhaired,  the  skins  are  once  more  soaked  in  milk  of  lime  for  a  few 
days,  and  then  scraped  on  the  flesh  side  to  render  it  very  even.  For  removing  the  lime 
which  obstructs  their  pores,  and  would  impede  the  tanning  process,  as  well  as  to  open 
these  pores,  the  skins  are  steeped  in  a  warm  semi-putrid  alkaline  liquor,  made  with 
pigeons'  and  hens'  dung  diffused  in  water.  Probably  some  very  weak  acid,  such  as  fer- 
mented bran-water,  would  answer  as  well,  and  not  be  so  offensive  to  the  workmen. 
(In  Grermany  the  skins  are  first  washed  in  a  barrel  by  a  revolving  axle  and  discs.)  They 
are  again  scraped,  and  then  sewed  into  bags,  the  grain  outermost,  like  bladders,  leaving 
a  small  orifice,  into  which  the  neck  of  a  funnel  is  inserted,  and  through  which  is  poured 
a  certain  quantity  of  a  strong  infusion  of  the  sumach  ;  and  they  are  now  rendered  tight 
round  the  orifices,  af\er  being  filled  out  with  air,  like  a  blown  bladder.  A  parcel  of  these 
mflttled  skins  are  thrown  into  a  very  large  tub,  containing  a  weaker  infusion  of  sumach, 
where  they  are  rolled  about  in  the  midst  of  the  liquor,  to  cause  the  infusion  within  to 
act  upon  their  whole  surface,  as  well  as  to  expose  their  outsides  uniformly  to  the  tan- 
ning action  of  the  bath.  After  a  while  these  bladder-skins  are  taken  out  of  the  bath, 
and  piled  over  each  other  upon  a  wooden  rack,  whereby  they  undergo  such  pressure  as 
to  force  the  enclosed  infusion  to  penetrate  through  their  pores,  and  to  bring  the  tannin 
of  the  sumach  into  intimate  contact,  and  to  form  a  chemical  combination  with  the  skin 
fibres.  The  tanning  is  completed  by  a  repetition  of  the  process,  of  introducing  some 
infusion  or  decoction  into  thtfm,  blowing  them  up,  and  floating  them  with  agitation  in 
the  ^ath.     In  this  way  goatskins  may  be  well  tanned  in  the  course  of  one  dav. 

The  bags  are  next  undone  by  removmg  the  sewing,  the  tanned  skins  are  scraped  aa 
before  on  the  currier's  bench,  and  hung  up  in  the  drjing  loft  or  shed ;  they  are  said 
now  to  be  "  in  the  crust."  They  are  again  moistened  and  smoothed  with  a  rubbing- 
tool  before  being  subjected  to  the  dyeing  operations,  in  which  two  skins  are  applied  face 
to  face  to  confine  the  dye  to  one  of  their  surfaces  only,  for  the  sake  of  economizing  the 
dyeing  materials  which  may  be  of  several  different  colors.  The  dyed  skins  are  grained 
by  being  strongly  rubbed  with  a  ball  of  box-wood,  finely  grooved  on  its  surface. 

Preparatory  to  being  dyed,  each  skin  is  sewed  together  edgewise,  with  the  grain  on 
the  outside,  and  it  is  then  mordanted  either  with  a  solution  of  tin,  or  with  alum  water. 
The  color  is  given  by  cochineal,  of  which  from  10  to  12  ounces  are  required  for  a  dozen 
of  skins.  The  cochineal  being  boiled  in  water  along  with  a  little  tartar  or  alum  for  a 
few  minutes,  forms  a  red  liquor,  which  is  filtered  tlirough  a  linen  cloth,  and  put  into  a 
clean  cask.  The  skins  are  immei*sed  in  this  bath,  and  agitated  in  it  for  about  half  an 
hour;  thev  are  taken  out  and  beaten,  and  then  subjected  to  a  second  immersion  in  the 
cochineal  bath.  After  being  thus  dyed,  they  are  rinsed  and  tanned  with  Sicilian  su- 
mach, at  the  rate  of  two  pounds  for  a  skin  of  moderate  size.  This  process  is  performed 
in  a  large  tub  made  of  white  wood,  in  the  liquor  of  which  the  skms  are  floated  like 
so  many  bladders,  and  moved  about  by  manual  labor  during  four  houra  They  are 
then  taken  out,  drained,  and  again  subjected  to  the  tanning  liquor;  the  whole  pro- 
cess reqiiiring  a  space  of  twenty-four  hours.  The  skins  are  now  unstitched,  rinsed, 
fulled  with  beetles,  drained,  rubbed  hard  with  a  copper  blade,  and  lastly  hung  up  to 
dry. 

Some  manufacturers  brighten  the  color  by  applying  to  the  surface  of  the  skins,  in  a 
damp  state,  a  solution  of  carmine  in  ammonia  with  a  sponge;  others  apply  a  decoction 
of  saffron  to  enliven  the  scarlet  tint.  At  Paiis  the  morocco  leather  is  tanned  by  agita- 
tion with  a  decoction  of  sumach  in  large  casks  made  to  revolve  upon  a  horizontal  axis, 
like  a  barrel  churn.  White  galls  are  sometimes  substituted  for  sumach ;  a  pound  being 
used  for  a  skin.     The  skins  must  be  finally  cleaned  with  the  utmost  care. 

The  black  dye  is  given  by  applying  with  the  brush  a  solution  of  red  acetate  of  iron  to 
the  grain  side.     Blue  is  communicated  bv  the  common  cold  indigo  vat ;  violets,  with  a 


LEATHER.  U 

light  blue  followed  by  cochineal  red ;  green,  by  Saxon  blue  followed  by  a  yellow  dye, 
usually  made  with  the  chopped  roots  of  the  barberry.  This  plant  servos  also  for  yel- 
lows. To  dye  olive,  the  skins  are  first  passed  through  a  weak  solution  of  green  vitriol, 
and  then  through  the  decoction  of  barberry  root,  containing  a  little  Saxon  blue.  Puce 
color  is  communicated  by  logwood  with  a  little  alum ;  which  may  be  modified  by  the 
addition  of  a  little  Brazil  wood.  In  all  these  cases  whenever  these  skins  are  dyed,  they 
should  be  rinsed,  wrung,  or  rather  drained,  stretched  upon  a  table,  then  besmeared  on 
the  grain  side  with  a  film  of  linseed  oil  applied  by  means  of  a  sponge  in  order  to  pro- 
mote their  glossiness  when  curried,  and  to  prevent  them  becoming  horny  by  too  rapid 
drying. 

The  last  process  in  preparing  morocco  leather  is  the  currying,  which  brings  out  the 
lustre,  and  restores  the  original  suppleness.  This  operation  is  practised  in  different 
manners,  according  to  the  purpose  the  skins  are  to  serve.  For  pocket-books,  portfolios, 
and  case-making  in  general,  they  must  be  thinned  as  much  as  possible  upon  the  flesh 
side,  moistened  slightly,  then  stretched  upon  the  table,  to  smooth  them ;  dried  again, 
moistened,  and  lastlj'^  passed  two  or  three  times  through  the  cylinder  press  in  different 
directions,  t'>  produce  the  crossing  of  the  grain.  The  skins  intended  for  the  shoemaker, 
the  saddler,  the  bookbinder,  <fec.,  require  more  pliancy,  and  must  be  difterentl}' curried. 
After  being  thinned,  they  are  glazed  with  a  polisher  while  still  moist,  and  a  grain  is 
formed  upon  the  flesh  side  with  the  roughened  lead  plate  or  grainer  of  the  curriers, 
called  in  French  pmnmelle ;  they  are  glazed  anew  to  remove  the  roughness  produced 
by  the  pommel,  and  finally  grained  on  the  flesb  side  with  a  surface  of  cork  applied  under 
a  pommel  of  white  wood. 

Tawing  of  Skins.  (Megisseriej  fr. ;  Weissgerberei,  Germ.)  The  kid,  sheep,  and 
lamb  skins,  are  cleansed  as  has  been  described  under  leather  in  the  Dictionary.  In  some 
factories  they  receive  the  tanning  power  of  the  submuriate  of  alumina  (from  a  solution 
of  alum  and  common  salt)  in  a  large  barrel-churn  apparatus  ;  in  which  they  are  sub- 
jected to  violent  agitation,  and  thereby  take  the  aluming  in  the  course  of  a  few  minutes. 
In  other  cases,  where  the  yolks  of  eggs  are  added  to  the  above  solution,  the  mixture, 
with  the  skins,  is  put  into  a  large  tub,  and  the  whole  trampled  strongly  by  the  naked 
feet  of  the  operator,  till  the  emulsion  of  the  e^g  be  forced  into  the  pores  of  the  skin. 
The  tawed  skins,  when  dry,  are  "  staked,"  that  is,  stretched,  scraped,  and  smoothed,  by 
friction  against  the  blunt  edge  of  a  semicircular  knife,  fixed  to  the  top  of  a  short  beam 
of  wood  set  upright.  The  workman  holding  the  extremities  of  the  skin  with  both  hands, 
pulls  it  in  all  directions  forcibly,  but  skilfully,  against  the  smoothing  "  stake." 

In  an  entertaining  article  on  tanning  in  the  1 1th  volume  of  the  Penny  Magazine,  at 
page  215,  the  following  description  is  given  of  one  of  the  great  tawing  establishments 
of  London : — 

"  In  the  production  of  *  imitation'  kid  leather,  the  skin  of  lambs  is  employed  ;  and 
for  this  purpose  lambskins  are  imported  from  the  shores  of  the  Mediterranean.  They 
are  imported  with  the  wool  yet  on  them ;  and  as  this  wool  is  valuable,  the  leather- 
manufacturer  removes  this  before  the  operations  on  the  pelt  commence.  The  wool  is 
of  a  quality  that  would  be  greatly  injured  by  the  contact  of  lime,  and  therefore  a  kind 
of  natural  fermentation  is  brought  about  as  a  means  of  loosening  the  wool  from  the  pelt. 
At  the  iViecfciwger  establishment  of  Messrs.  Bevington  and  Co.,  Bermondsey,  one  of  the 
buildings  presents,  on  the  ground  floor,  a  flight  ef  istone  steps,  leading  down  to  a  range 
of  subterranean  vaults  or  close  roomsj  into  which  the  lambskins  are  introduced  in  a 
wet  state,  after  having  been  steeped  in  water,  *  broken'  on  the  flesh  side,  and  drained. 
The  temperature  of  these  rooms  is  nearly  the  same  all  the  year  round,  a  result  obtained 
by  having  them  excluded  as  much  as  possible  from  the  variations  of  the  external  atmo- 
sphere ;  and  the  result  is  that  the  skins  undergo  a  kind  of  putrefactive  or  fermenting 
process,  by  which  the  wool  becomes  loosened  from  the  pelt.  During  this  chemical 
change  ammonia  is  evolved  in  great  abundance  ;  the  odor  is  strong  and  disagreeable ; 
a  lighted  candle,  if  introduced,  would  be  instantly  extinguished,  and  injurious  effects 
would  be  perceived  by  a  person  remaining  long  in  one  of  the  rooms.  Each  room  is 
about  ten  feet  square,  and  is  provided  with  nails  and  bars  whereon  to  hang  the  lamb- 
skins. The  doors  from  all  the  rooms  open  into  one  common  passage  or  vault,  and  are 
kept  close,  except  when  the  skins  are  inspected.  It  is  a  point  of  much  nicety  to  deter- 
mine when  the  fermentation  has  proceeded  to  such  an  extent  as  to  loosen  the  wool  from 
the  pelt ;  for  if  it  be  allowed  to  proceed  beyond  that  stage,  the  pelt  itself  would  become 
injured." 

When  the  fermentation  is  completed,  generally  in  about  five  days,  the  skins  are  re- 
moved to  a  beam,  and  there  *  slimed' — that  is,  scraped  on  the  flesh  side,  to  remove  a 
slimy  substance  which  exudes  from  the  pores.  The  wool  is  then  taken  ofl*,  cleaned, 
and  sold  to  the  hatters,  for  making  the  bodies  of  common  hats.  The  stripped  pelts  are 
steeped  in  lime-water  for  about  a  week,  to  kill  the  grease ;  and  are  next  "  fleshed  on  the 
beam."    After  being  placed  in  a  "  drench,"  or  a  solution  of  sour  bran  for  some  days  to 


64 


LEATHER. 


,H    ' 


1, 


remove  the  lime  and  open  the  pores,  the  skins  are  alumed,  and  subjected  to  nearly 
the  same  processes  as  the  true  kidskins.  (See  Leather.)  These  Mediterranean  lamb- 
skins do  not  in  general  measure  more  than  about  20  inches  by  12;  and  each  one  fur- 
nishes leather  for  two  pairs  of  small  gloves.  These  kinds  of  leather  generally  leave  the 
leather-dresser  in  a  white  state ;  but  undergo  a  process  of  dyeing,  softening,  "  stroking," 
&c.,  before  being  cut  up  into  gloves. 

The  tanning  of  one  average-sized  skin  requires  about  1}  lbs.  of  good  Sicilian 
sumach ;  but  for  leather  which  is  to  receive  a  bright  scarlet  dye,  from  one  half  to  three 
quarters  of  a  pound  of  gall-nuts  are  employed  in  preference.  Inferior  goatskins  are 
tanned  with  a  willow-bark  infusion,  in  pits,  in  which  they  are  turned  repeatedly,  and 
laid  out  to  drain,  as  in  tanning  sole-leather.  The  finest  skins  for  the  brightest  scarlet 
are  cured  with  salt,  to  prevent  their  receiving  damage  in  the  transport,  and  are  dyed 
before  being  tanned.     This  method  is  practised  in  Germany  and  France. 

Leather  of  deer  and  sheep-skins  is  prepared  with  oil,  for  the  purpose  of  making 
breeches,  &c.,  and  for  wash-leather,  used  in  cleaning  plate.  After  they  are  completely 
washed,  limed,  and  beamed,  as  above  described,  they  have  their  **  grain -'-surface  re- 
moved, to  give  them  greater  softness  and  pUability.  This  removal  of  the  grain  is 
called  "  frizing,"  and  it  is  done  either  with  the  round  edge  of  a  blunt  knife,  or  with 
pumice-stone.  After  being  freed  from  the  lime  by  steeping  in  fermented  bran-water, 
they  are  pressed  as  dry  as  may  be,  and  are  then  impregnated  with  cod-oil,  by  beating 
with  stocks  in  the  trough  of  a  kind  of  fulling-mill.  Previously  to  the  application  of 
the  oil,  they  are  usually  beat  for  some  time  alone  to  open  their  substance.  The  oiled 
skins  are  stretched,  hung  up  for  some  time  in  the  air,  then  fulled  with  oil  as  before — a 
process  which  is  8  or  9  times  repeated.  The  oil  is  slowly  and  evenly  poured  upon  the 
skins  in  the  trough,  during  the  action  of  the  beaters.  One  hundred  skins  usually  take 
up  in  this  way  from  two  to  three  gallons  of  oil.  The  fulled  oiled  skins  are  thrown  into* 
large  tubs,  and  left  for  some  time  to  ferment,  and  thereby  to  combine  more  intimately 
with  the  oil.  They  are  lastly  subjected  to  a  weak  potash  ley  bath,  to  strip  them  of  the 
loosely  adhering  oil.  They  are  then  hung  up  in  the  air  to  dry,  and  dressed  for  the 
market. 

The  quantity  of  hides  and  skins  converted  into  leather  yearly  in  England  is  almost 
incredibly  large.  At  Messrs.  Bevington's  establishment  alone  there  are  about  250,000 
skins  annually  converted  into  leather  by  the  aluming  or  tawing  process ;  220,000  by 
the  sumach  tanning  process  ;  as  also  a  small  number  by  the  oil-dressing  process.  For 
the  importation  and  exportation  of  skins,  untanned  and  tanned,  see  Hides. 

Leather  and  Skins  in  the  Exhibition. — ^The  present  class  includes  a  variety  of  manu- 
facturing processes  relating  to  the  commeicial  preparation  of  animal  substances  in  the 
form  of  leather,  skins,  fur,  hair,  and  feathers.  Until  within  a  recent  period,  experience 
rather  than  science  has  directed  the  labors  of  manufacturers  in  their  operations  upou 
these  substances.  And  at  present  the  rules  taught  by  experience  are,  m  many  cases, 
still  pursued  in  practice,  with,  however,  such  modifications  as  an  intelligent  compre- 
hension of  the  operations  of  the  chemical  and  other  philosophical  laws  put  into  force 
in  the  processes  would  suggest. 

The  following  sub-classes  are  recognized  in  this  class ;  a,  leather,  as  rough  and  tanned, 
curried,  enamelled,  dyed;  oil-leather,  as  buckskin,  doeskin,  <fec. ;  white  and  alum  lea- 
ther; sheep  and  skin  rugs,  parchment  and  vellum;  b,  saddlery,  and  harness  ;  c,  mis- 
cellaneous; D,  shink  and  furs  of  all  descriptions  for  personal  and  domestic  use;  e,  fea- 
thers, as  those  of  ostrich,  marabout^  <fec. ;  f,  hair,  ornamentally  and  usefully  applied. 

The  localities  in  which  the  manufactures  concerned  in  this  class  are  carried  on,  and 
from  whence  articles  for  exhibition  have  chiefly  been  derived,  are  Bermondsey,  where 
the  preparation  of  leather  has  been  successfully  conducted  during  a  very  long  period, 
Hull,  Swansea,  Bristol,  Cork,  Liverpool,  Edinburgh,  and  Falmouth. 

The  manufacture  of  leather  has  been  estimated  as  only  fourth  in  importance  among 
the  national  manufactures  of  Great  Britain.  A  large  amount  of  capital  is  eraploj-ed  in 
its  production,  and  the  number  of  artisans  and  others  directly  supported  by  this  branch 
of  industry  has  been  taken  to  amount  to  nearly  a  quarter  of  a  million.  The  total  an- 
nual value  of  the  leather  manufactures  is  computed  at  about  fourteen  millions  sterling. 
It  appears  probable  that  in  the  mere  article  of  boots  and  shoes,upwards  of  seven  millions 
sterling  are  annually  expended  by  the  inhabitants  of  this  countr3^  If  it  be  considered  that 
rather  more  than  half  the  leather  produced  is  thus  applied,  the  remainder  is  employed 
in  the  production  of  harness,  saddlery,  gloves,  and  the  multifarious  purposes  for  which 
leather  is  applicable.  Of  late,  chemistry  has  been  studied  attentively  by  those  dependent 
upon  this  branch  of  industry,  and  successful  results  have  ensued.  A  variety  of  patent 
processes  exist  by  which  the  enormous  amount  of  time  involved  in  tanning  on  the  old 
system  is  abridged  to  a  surprising  extent  With  some  specimens  of  leather  it  has  not 
been  unusual  to  devote  eighteen  months  or  upwards  to  their  combination  with  the 
native  principles  of  the  bark.     A  few  weeks  are  sufficient,  under  several  of  the  new 


LEATHER. 

systems  to  eflFect  the  same  obj(  *,t  But  it  is  stated  that  the  leather  produced  rapidly 
differs  from  that  produced  by  the  slower  process  of  combination  in  its  durability  and 
Bohdity.  And  it  is  considered  bv  some,  that  time  is  an  essential  element  in  the  manu- 
facture, and  that  it  cannot  be  advantageously  shortened  to  any  considerable  extent. 

Leather  is  unquestionably  a  chemical  compound,  and  this  renders  it  probable  that 
a  slow  and  gradual  process  of  combination  between  the  gelatine  of  the  skin  and  the 
tannic  acid  of  the  bark  may  produce  a  leather  to  some  extent  of  different  properties 
to  that  formed  by  a  quicker  operation.  A  very  large  amount  of  leather  is,  however, 
manufactured  by  the  rapid  process,  from  which  it  may  be  concluded  that  the  product 
possesses  great  commercial  value.  A  great  variety  of  leathers  in  all  conditions  and 
states  of  manufacture  is  exhibited,  with  instructive  series  illustrating  the  peculiarities 
of  different  methods  of  nianufacture,  according  to  the  difference  of  the  purposes  for 
which  the  prepared  skin  is  to  be  afterwards  applied. 

An  extensive  and  interesting  collection  of  furs  is  exhibited.  Probably  the  oppor- 
tunity has  never  before  presented  itself  for  a  complete  study  of  this  class  of  manufac- 
ture. Furs  of  the  most  rare  description,  devoted  only  to  the  use  of  monarchs,  ar« 
among  these  specimens.  To  the  naturalist  deJrous  of  ascertaining  the  genera  and 
species  yielding  the  furs  of  commerce— a  subject  on  which  much  conflicting  opinion 
exists— these  objects,  which  are  fullv  and  correctly  described  in  the  catalogue  of  this 
clas?,  will  be  highly  interesting  and  instructive.  Feathers  and  hair  are  also  repre- 
sented by  various  interestmg  objects,  possessing  their  peculiar  merits  and  attraction. 
The  numb^^r  of  exhibitoi-s  in  this  class  is  considerable:  but  since  it  includes  boot*  and 
shoes,  and  other  articles  of  personal  and  domestic  use  in  addition  to  saddlery  Ac.  the 
number  of  persons  actually  appearing  in  the  capacity  of  manufacturers  is  to  be  diitin- 
guishel  from  the  proprietors.  And,  as  is  the  common  rule,  the  class  of  producers  or 
manufacturers  bears  only  a  small  proportion  to  that  of  proprietors,  or,  in  the  commer- 
cial  sense,  vendors  of  manufactured  articles. 

Hudson's  Bay  Company,  producers.— Specimens  of  skins  from  the  Arctic  regiona. 
belonging  to  the  Hudson's  Bay  Company,  selected  for  the  Exhibition  from  then-  im- 
portation of  1851,  prepared  and  arranged  by  the  exhibitofs  from  No.  1.  to  No  27 

The  immense  tracts  of  country  over  which  the  Hudson's  Bay  Company  has  control 
may  be  considered  as  vast  hunting-grounds,  affording  a  varied  and  exhaustless  supply 
fl^Pl^  The^territorial  i)os8essions  of  this  Company  cover  nearly  one-eighth  of  the 
habitable  globe.  Russia  is  next  m  order  and  importance  in  this  respect,  but  with  a 
different  race  of  animals.  The  fur  produce  of  North  America  and  the  Canadas  is  also 
important  As  we  approach  the  tropics  and  the  warmer  regions,  the  silky  fur  with 
which  the  animals  are  clothed  in  the  northern  climes  disappears,  and  fur  of  a  totally 
different  character  is  met  with,  which,  although  splendid  in  appearance,  is  not 
aaapted  tor  warmth  or  general  use.  i  r  -^ 

Table  of  Imports  and  Exports. 


Racoon  - 
Beaver  - 
Chinchilla 
Bear 

Fisher     - 
Fox,  red  - 
"    cross 
"    silver 
"    white 
"    gray 
Lynx 
Martin     - 
Mink       - 
Musquash 
Otter 
Fur,  seal 
Wolf       - 


Total 

Importation  into 

England. 


526,000 

60,000 

85,000 

9,500 

11,000 

50,000 

4,600 

1,000 

1,500 

20,000 

55,000 

120,000 

245,000 

1,000,000 

17,500 

15,000 

15,000 


Exported. 


525,000 

12,000 

30,000 

8,000 

11,000 

50,000 

4,600 

1,000 

500 

18,000 

50,000 

15,000 

75,000 

150,000 

17,500 

12,500 

16,000 


Consumed  in 
England. 


none 
48,000 
55,000 
1,500 
none 
none 
none 
none 
1,000 
2,000 
5,000 
105,000 
170,000 
850,000 
none 
2,600 
none 


Vol.  XL 


/ 


6$ 


LEATHER. 
European  Fubs. 


I/EATHER. 


•7 


Martin,  stone  and  baum 

120,000 

6,000 

116,000 

Squirrel  -            -            -            - 

2,271,258 

77,160 

2,194,098 

Fitch       .... 

65,091 

28,276 

86,815 

Kolinski               .             -             . 

63,410 

200 

53,210 

Ermine    -            -            -            - 

187,104 

none 

187,104 

1.  Group  of  black  and  silver  furs  ( Vulpis  pelvis,  var.  argentatw). 

2.  Group  of  foxes  {Vulpis  fulviSy  var.  decusnatiu). 
8.  Group  of  red  and  silver  foxes  (  VtUpia  fulvis). 

4.  "  white         "  ( Vulpis  lagopus). 

5.  "  kitt  "  {Vnfpis  velox). 

The  black  and  silver  fox  is  the  most  valuable  of  his  tribe;  they  are  generally  pur- 
ehasod  for  the  Russian  and  Chinese  markets,  being  highly  prized  in  those  countries. 
The  cross  and  red  fox  are  used  by  the  Chinese,  Greeks,  Persians,  Ac,  for  cloak-linings 
and  for  trimming  dresses.  The  white  and  blue  fox  is  used  in  this  and  other  countries 
for  ladies'  wear.  In  the  sumptuary  laws  passed  in  the  reign  of  Henry  HI.,  the  fox  is 
named  with  other  furs  then  in  use. 

7.  Group  of  beaver  {Castor  Americanwt). 

The  beaver  in  former  years  was  one  of  the  Hudson's  Bay  Company's  most  valuable 
productions;  but  since  its  use  has  been  almost  entirely  discontinued  in  the  manufac- 
ture of  hat^',  it  has  lost  much  of  its  value.  Experiments  have,  however,  been  made, 
and  with  prospect  of  success,  to  adapt  its  fine  and  silky  wool  to  weaving  purposes. 
The  skin  of  the  beaver  is  prepared  by  a  new  process,  after  which  the  surface  is  cut  by 
a  new  and  ingenious  machine,  and  the  result  is  a  beautiful  fur  for  ladies  wear.  It  is 
exported  in  its  prepared  state  to  various  parts  of  Europe  and  the  East. 

The  rich  white  wool  from  the  under  part  of  the  beaver  is  largely  exported  to  France. 

8.  Group  of  lynx  {Felis  Canadensis). 

9.  "  lynx  cat  {Felis  rufa). 

Both  the  above  furs,  when  dyed,  were  formerly  much  used.  It  is  still  dyed  and 
prepared,  and  exported  in  large  numbei-s  for  the  American  market  In  its  natural 
state,  it  is  a  grayish  white,  with  dark  spots  and  is  used  by  the  Chinese,  Greeks,  Per- 
sians, and  others,  for  cloaks,  lining,  facings,  Ac. ;  it  is  very  soft,  warm,  and  light 
Tlie  fur  formei'ly  called  the  lueern  is  the  lynx. 

21.  Group  of  black  bear  ( Ursus  Americanus). 

22.  ••  brown  bear  ( Urms,  var.  Americanus). 
28.       **  gray  bear  (f/r*M«/(?rox). 

The  large  North  American  black  bear  is  technically  termed  the  army  bear,  because 
it  is  generally  used  for  military  purposes  in  this  and  other  countries,  tor  caps,  pistol- 
holsters,  rugs,  carriage  hammer-cloths,  sleigh-coverings,  Ac.  The  fine  black  cub  bears 
are  much  sought  after  in  Russia  for  making  shube-linings,  coat-linings,  trimmings, 
facings,  Ac.  The  other  sorts  with  the  large  gray  bears,  for  sleigh-coverings,  and  ac- 
companiments, Ac.  The  white  polar  bear,  the  supply  of  which  is  very  limited,  is 
generally  made  into  rugs,  which  are  often  bordered  with  the  black  and  gray  bear. 
The  brown  or  Isabella  is  at  the  present  time  used  for  ladies'  wear  in  America. 

301a.  Nicholay,  John  Av^.,  &  Son,  82  Oxford-street  Collectors,  Importers, 
Manufacturers,  Ac.  Selected  from  Canadian  importation,  with  the  assistance  of  C.  M. 
Lampson,  Elsq. 

28.  Group  of  racoon  {Procyon  lator). 

The  finest  racoon  furs  are  produced  in  North  America,  and  are  imported  into  this 
country  in  immense  numbers.  They  are  purchased  here  by  the  merchants  who  at- 
tend the  periodical  fur  sales,  and  who  dispose  of  lai^e  quantities  at  the  great  fair  at 
Leipsic ;  they  are  principally  used  in  Russia  and  throughout  Germany,  for  lining 
shubes  and  coats,  and  are  exclusively  confined  to  gentlemen's  wear.  Tlie  dark  skins 
are  the  choicest  and  are  very  valuable. 

64.  Group  of  seal,  {Pkoca),  Georgia,  Shetland  Isles,  Falkland  Isles,  Lomar's  Island, 

and  Cape. 

66.  "  plucked  and  prepared  seal,  natural  color. 

66.  **  plucked  and  prepared  seal,  dyed. 

67.  "  Greenland  and  Newfoundland  seal 

68.  "  Greenland  and  Newfoundland  seal,  dyed. 

69.  "       •      spotted  and  silver  seaL 

Tlie  seal  is  an  inhabitant  of  most  countries ;  it  is  found  in  the  high  northern  latitudes 
in  immense  numbers ;  ships  are  purposely  fitted  for  its  capture ;  the  oil  produced  by  the 
animal,  together  with  its  skin,  render  it  (connected  as  it  is  with  the  whale  fishery^ 


important  to  the  trader  and  interesting  to  the  naturalist  The  skins  are  salted  and 
packed  in  casks,  in  which  state  they  are  sent  to  this  country ;  they  are  then  sorted 
and  selected  for  various  purposes ;  those  suitable  for  leather  pass  into  the  tannei-s* 
hands,  and  make  a  beautiful  leather,  which  is  used  for  ladies'  shoes.  The  blue  back, 
the  hair  and  the  silver  seal  are  dressed  and  used  in  their  natural  state,  and  also  dyed 
and  exported  in  large  quantities.  The  fur  seal,  the  supply  of  which  is  always  small 
compared  with  the  otlier  kinds,  undergoes  a  process  to  prepare  it  for  its  intended  use. 
It  is  brought  at  the  present  time  to  a  great  degree  of  perfection  in  this  country :  when 
divested  of  the  long,  coarse  hair  (which  protects  it  in  its  native  element)  there  re- 
mains the  rich,  curly,  silky,  yellowish  down,  in  which  state  it  was  formerly  used  for 
travelling  caps  and  other  purposes.  It  is  now  seldom  made  use  of  in  that  state,  but 
dyed  a  beautiful  Vandyke  brown,  giving  it  the  appearance  of  the  richest  velvet,  and 
IS  manufactured  m  every  variety  of  shape  and  form,  as  articles  of  dress  for  ladies*, 
gentlemen's  and  children's  wear. 

South  American.— 10.     Group  of  chinchilla,  Buenos  Ayres  {Chinchilla  lanigerai. 

71.  Group  of  chinchilla,  Arica  {Chinchilla  laniyera). 

72.  Group  of  bastard  chinchilla  or  Lima  {Chinchilla  laniyera). 

The  chinchilla  is  exclusively  a  South  American  animal,  and  was  introduced  into 
this  country  and  France  about  forty  years  since. 

Group  of  ermine  {Mustela  erminea). 

The  ermine  is  produced  in  most  countries,  but  the  best  is  from  Russia,  Sweden  and 
Norway,  and  is  killed  in  winter  when  the  fur  is  pure  white  (except  the  tail,  with  its 
jet  black  tip),  it  being  in  that  season  in  its  greatest  perfection ;  in  summer  and  spring 
It  IS  gray,  and  of  little  or  no  value.  It  is  the  weasel  of  more  southern  climes  The 
ermine  is  the  royal  fur  of  Russia,  Germany,  Spain,  Portugal,  Italy.  Ac,  In  England 
at  the  coronation  of  the  sovereign,  the  minever,  as  the  ermine  is  styled  in  heraldic 
language,  is  used,  being  powdered,  that  is  studded  with  black  spots.  The  spote  or 
powdered  bars  on  the  minever  capes  of  the  peers  and  peeresses  being  in  rows,  and  the 
number  of  rows  or  bars  denoting  their  various  degrees  of  rank  ;  the  sovereign  alone 
and  the  blood  royal  having  the  minever  of  the  coronation  robes  powdered  all  over  a 
black  spot  being  inserted  in  about  every  square  inch  of  the  fur,  crimson  velvet  being 
used  on  that  occasion.  The  crown  is  also  adorned  with  a  band  of  minever  with  a 
smgle  row  of  SjiOts;  the  coronets  of  the  peers  and  peeresses  having  a  similar  krranee- 
ment  The  black  spots  are  made  of  the  black  Astracan  lamb.  On  state  occasions  in 
the  House  of  Lords,  the  peers  are  arrayed  in  their  robes  of  state,  of  scarlet  cloth  and 
goltl  lace,  with  bars  or  rows  of  pure  minever,  more  or  less  according  to  their  decrees 
ot  rank,  the  sovereign  alone  wearing  the  royal  minever  powdered  all  over  The 
judges  m  their  robes  of  office  are  clad  in  scarlet  and  pure  ermine.  The  ermine  with 
the  tail  of  the  animal  inserted  therein,  is  used  as  articles  of  dress  for  ladies  in  every 
variety  of  shape  and  form,  according  to  the  dictates  of  fashion,  and  also  as  cloak  linings. 

Ihe  mmever  can  only  be  worn  on  state  occasions  by  those  who  by  their  rank  are 
entitled  to  its  use,  but  as  an  article  of  fashion  for  ladies'  wear  there  is  no  prohibition 
m  force.  In  the  reign  of  Edward  III,  furs  of  ermine  were  strictly  forbidden  to  be 
worn  by  any  but  the  royal  family,  and  its  general  use  is  prohibitedf  in  Austria  at  the 
present  time.  In  mercantile  transactions,  ermine  is  always  sold  by  the  timber  which 
consists  of  forty  skins.  The  minever  fur  of  a  former  era  was  the"^  white  bellv  of  the 
gray  squirrel.  -^ 

36.  Group  of  kolinski  {Mustela  Sibirica). 

The  kolinski  or  Tartar  sable  is  produced  from  Russia,  belongs  to  the  weasel  tribe 

.W.'^  "m''    vT  *  b"g^,t, yellow;  it  is  much  used  in  its  natural  state  and  also  dyed  tcJ 
imitate  the  cheaper  sables.  j««  w 

37.  Group  of  squirrel,  black  {Sciurus  niyer). 

88.         "  squirrel,  blue  {Sciurus,  var.  niqer). 

39.         '♦         squirrel,  kazan  {Sciurus,  var.  Griscus). 
*0.         •'  squirrel,  red  {Sciurus  vulyarisi 

in  8uc\?mmPnL''n''"''K  '  ''^  Russia  (where  it  m  produced  in  the  greatest  perfection) 
ILnce  to  t^fs  c^^^^^^^  appear  a  most  incredible:  the  importktion  from^ 

SriininVis  mlTf  ^  *  r^  ^^^.  ^^^"^  exceeding  2,000.000.  The  celebrated  Weisen- 
linLrweihs  onlv  ^'?™  '^'  ""^'^  ^^^'^  ^^  ^^'  ?*''^  ^^"^  «^""'^«'-  ^  ^""-^i^d  cloak 
nnis  are  made  ?rn^  ^T '  {'  ''  ^T^""  ^  *^^  P''''  ^'*"-  ^"^  ^o'^^"-  «'""**««•  *»»« 
part  of  theTail  left  nn  \^l'^  ^'5^*"?  ^^^^  P^'*  «f  ^he  squirrel,  the  best  having 
'^^^^G^^^^^^^  ^^out  23,000.000  annually. 

du|it ti^z^ij^i^  zn^-z^y -^ ''-  ^*  !>— ^  ^^  ^  p- 

42.  Groiv»  of  Crimea  gray  lamb 


48. 


rimea  gray  lamb. 
Ukraine  black  lamb. 


/ 


98 


LEATHER  SPUmNG. 


w 


lit 


!!  i^i 


44.  Group  of  Aatracan  black  lamK 


46. 
U, 

48. 
ML 

60. 


M 


<( 


Astracan  gray  lamb. 

Persian  black  lamb. 

Persian  gray  lamb. 

Spanisli  lamb. 

Hungarian  lamb. 

Engbsh  lamb. 

The  gray  and  black  Persian  lamb  is  mostly  used  for  gentlemen's  cloak  and  coat  lin- 
ings, for  facings,  collars,  caps,  Ac,  and  also  lor  army  purposes.  The  Astracan  lamb  is 
a  rich,  wavy,  glossy,  black  skin,  very  short  in  the  fur,  having  the  appearance  of  beau- 
tiful  watered  silk :  in  order  to  obtam  this  choice  skin,  it  is  averred  that  the  parent 
sheep  is  destroyed  a  certain  time  before  the  birth  of  the  lamb.  The  Persian  gray  and 
black  lamb  is  covered  with  very  minute  curls;  this  is  produced,  it  is  said,  by  the  ani- 
mal being  as  soon  as  bom  sewn  up  tightly  in  a  leathern  skin,  which  prevents  the  curl 
expanding.  The  Hungarian  lamb  is  produced  in  that  country  in  immense  numbers ; 
of  It  the  national  coat,  called  the  Juhasz  Bunda,  is  made.  In  the  summer  or  wet  wea- 
ther the  fur  or  woolly  part  is  worn  outside ;  in  winter,  when  warmth  is  required,  it  is 
reversed:  the  skin  is  tanned  or  dressed  in  a  way  peculiar  to  the  country,  and  decorirted 
and  embroidered  in  accordance  with  the  means  and  taste  of  the  wearer.  In  Spain  the 
lamb-skin  is  used  for  the  well-known  characteristic  short  jacket  of  that  country,  which  is 
adorned  with  filigree  silver  buttons;  the  coarser  kinds  of  both  colors  are  used  for  our 
cavalry,  and  is  also  employed  for  mounting  and  bordering  skins,  as  leopards,  tigers, 
Ac,  for  ornamental  and  domestic  purposes.  In  the  reign  of  Richard  II.,  the  sergeant- 
at-law  wore  a  robe  furred  inside  with  white  lambskin  and  a  cape  of  the  same. 

61.  Group  of  Perewartzki. 

62.  "  Hamster. 

The  above  are  from  Russia:  the  former  is  used  by  ladies ;  the  latter  is  made  into 
cloak  linings,  which  are  exceedingly  light,  durable,  and  cheap. 

63.  Group  of  colored  cat 

64.  "  black  cat 
66.       "  black  Dutch. 
66.        **  colored  Dutch. 

Tlie  cat,  properly  attended  to  and  bred  purposely  for  its  skin,  supplies  a  most  use- 
ful and  durable  fur:  in  Holland  it  is  bred  and  kept  in  a  confined  state  till  the  fur  is 
in  its  greatest  perfection,  and  is  fed  entirely  on  fisli.  In  other  countries  and  especially 
in  our  own,  it  is  produced  in  large  numbers.  The  wild  cat  is  much  larger  ana  longer 
in  the  fur,  and  is  met  with  in  extensive  forests,  particularly  in  Hungary :  the  color  is 
gray,  spotted  with  black,  and  its  softness  and  durability  render  it  suitable  for  cloak 
and  coat  linings,  for  which  purposes  it  is  much  used.  The  black  species  is  also  much  in 
request,  and  similarly  use^  and  with  the  spotted  and  striped  varieties,  is  made  into 
wrappers  for  open  carriages,  sleigh  coverings,  and  railway  travelling. 

92.  Group  of  dyed  lynx,  see  No.  8. 

94*        "  pengum  {Speniscus  aptenodytes). 

96.        "  grebe  {Podiceps  cristata). 

The  grebe  is  an  aquatic  bird,  inhabiting  most  of  the  large  lakes  in  Europe.  TIjc 
choicest  specimens  are  from  Geneva,  Italy,  and  Holland.  The  feathers  are  of  rich 
white,  havmg  the  appearance  of  polished  silver,  the  plumage  on  the  outer  edge  of  the 
skin  being  a  rich  dark  brown ;  it  is  used  by  ladies  and  forms  a  beautiful  article  of 
dress,  and  is  worn  as  trimmings  for  the  trains  of  court  and  drawing-room  dresses, 
for  muflfs,  cuffs,  boas,  Ac  It  is  verv  durable ;  the  exquisite  smoothness  of  its  fea- 
thers prevents  its  soiling  with  wear, 

96.  Specimen  of  swan  feathers. 

97.  "  goose  feathers. 

98.  "  eider  down. 

The  bird  from  which  the  down  is  taken  is  found* in  large  numbers  in  Iceland,  Nor- 
way, Sweden,  Ac. ;  its  color  is  dark  gray,  and  its  elasticity,  lightness,  and  resistance 
to  wet,  are  prominent  amongst  its  other  advantages:  it  is  used  for  the  inside  stufiing 
of  muffs.     On  the  continent  the  well-known  eider-down  quilts  are  largely  used. 

99 — 116.  Suits  of  Russia  sable;  Hudson's  Bay  sable;  sable  tail,  mink ;  chinchilla; 
grebe;  sea  otter;  Siberian  squirrel,  with  tails ;  kolinski;  minever;  ermine;  moleskin; 
natural  beaver;  dyed  beaver;  seal;  swan;  goose-down. 

The  down  of  the  goose  is  manufactured  by  being  sewn  on  textile  fabrics.  It  is  a 
specimen  of  Irish  industry,  and  has  been  patronized  and  sold  in  England  extensively 
for  the  benefit  of  the  Irish  female  poor,  by  whom  it  has  been  made  up.  The  price, 
compared  with  the  true  swan's  down,  is  very  moderate.  Being  sewn  upon  cloth,  it 
can  oe  washed. 

LEATHER  SPLITTING.     This  operation  is  employed  sometimes  upon  certain 


LEATHER  SPLITTING. 

iorts  of  leather  for  glovers,  for  bookbinders,  sheath-makers,  and  always  to  giv«  a  uni- 
form thickness  to  the  leather  destined  for  the  cotton  and  wool  card-makers. 

J*lg*.  863,  864, 866,  866,  represent  a  well-contrived  machine  for  that  purpose,  of  which 
Jig.  863  shows  the  front  view.  Jig.  864  a  view  from  the  left  side,  Jig.  866  a  ground  plan, 
&nd  Jig.  8C5  a  vertical  section  across  the  machine,  a  is  a  strong  table,  furnished  with 
four  legs  b,  which  to  the  right  and  left  hand  bears  two  horizontal  pieces  c.     Each  of 


868 


0  2  0  X  «X  oX 


these  pieces  is  cut  out  in  front,  so  as  to  form  in  its  substance  a  half-round  fork,  that 
receives  a  cylinder  d^  carrying  on  its  end  a  toothed  spur-wheel  e.     Motion  is  com- 


municated to  the  wheel  by  means  of  the  handle/,  upon  whose  axis  the  pinion,  t,  is  fixed, 
working  into  the  wheel  d,  made  fast  to  the  end  of  the  cylinder  round  which  the  leathei 
18  rolled.  The  leather  is  fixed  at  one  of  its  ends  or  edges  to  the  cylinder,  either  with  » 
wedge  pressed  into  a  groove,  or  Ay  a  moveable  segment  of  the  cylinder  itself. 

The  table,  a,  is  cut  out  lengthwise  with  a  slot,  that  is  widened  below,  as  shown  in 
fig.  865. 

The  knife  h  (/lg». 865  and  866)  is  fixed  flat  upon  the  table  with  screw  bolts,  whose 


/ 


70 


LEGUMINE, 


LIMESTONE. 


71 


I-. 


M 
m 


ill 


if  I 


ii 


heads  are  countersunk  into  the  table,  and  secured 'vrith  taps  beneath  (/^.  865),  the  edg« 
of  the  knife  being  placed  horizontally  over  the  opening^,  and  parallel  with  it. 

In  Jig.  865,  the  leather,  k,  is  shown  advancing  against  the  knife,  getting  split,  and  has 
a  portion  coiled  round  the  cylinder,  which  is  made  to  revolve  in  proportion  as  the 
leather  is  cleft  The  upper  portion  of  the  leather  is  rolled  upon  tlie  cyhnder  d,  while 
the  under  halt  /,  falls  through  the  oblong  opening  upon  the  ground. 

In  regulating  the  thickness  of  the  split  leather,  the  two  supports,  wi,  act ;  they  are 
made  fast  to  the  table  a  (one  on  each  side  of  the  knife),  and  are  mortised  into  the  table 
by  two  tenons  secured  beneath.  These  supports  are  furnished  near  their  tops  with 
keyed  slots,  by  means  of  which  the  horizontal  iron  rod  o  {Jigs.  863,  865,)  is  secured,  and 
outside  of  the  uprights  they  press  upon  the  springs  /)p,  which  tend  to  raise  the  rod,  o,  in 
its  two  end  slots;  but  the  adjusting  screws  9,  which  pass  down  through  the  tops  of  the 
supports  into  the  mortise  n  {Jig.  865),  and  press  upon  the  upper  half  of  the  divided 
tenon,  counteract  the  springs,  and  accordingly  keep  the  rod,  0,  exactly  at  any  desired 
height  or  level  The  iron  rod,  o,  carries  another  iron  bar,  r,  beneath  it,  parellel  and 
also  rectangular,  Jig.  865.  This  lower  bar,  which  is  rounded  at  its  under  face,  lies  upon 
and  presses  the  leather,  by  the  action  of  two  screws,  which  pass  through  two  upright 
pieces  s{Jig».  863,  and  865,)  made  fast  to  the  table;  thus  the  iron  bar,  r,  may  be  made 
to  press  forwards  the  edge  of  the  knife,  and  it  may  be  adjusted  in  its  degree  of  pressure, 
according  to  the  desired  thickness  of  the  leaf  of  split  leather,  that  passes  through 
under  it 

Fig.  865,  shows  that  the  slant  or  obliquity  of  the  knife  is  directed  downwards,  over 
one  of  the  edges  of  the  oblong  opening  g ;  the  other  edge  of  this  opening  is  provided 
with  an  iron  plate  t  {Jigs.  865,  866),  which  serves  to  guide  the  blade  in  cutting  the 
leather  to  the  proper  depth.  For  this  purpose  the  plate  is  made  adjustable  by  means  of 
the  four  springs  u  {figs  865,  866),  let  into  the  table,  which  press  it  downwards.  Four 
screws,  v,  pass  down  through  the  table,  each  belonging  to  its  respective  springs  u,  and 
by  means  of  these  screws  the  plate,  t,  may  be  raised  in  any  desired  degree.  Each  of 
the  screws,  u,  has  besides  a  small  rectangular  notch  through  which  a  screw  bolt,  x,  passes, 
by  which  the  spring  is  made  fast  to  the  table.  Thus  also  the  plate,  t,  may  be  made  to 
approach  to  or  recede  from  the  knife. 

y,  in^».  863,  and  865,  is  a  flat  board,  laid  upon  the  leather  a  little  behind  the  edge 
of  the  plate  t;  this  board  is  pressed  by  the  cylinder  z,  that  lies  upon  it  and  whose 
tenons  rest  in  mortises  cut  out  in  the  two  supports  a'.  The  cylinder,  z,  is  held  in  its 
position  by  a  wedge  or  pin  b  {Jigs.  863,  and  864),  which  passes  through  the  supports. 
When  the  leather  has  been  split  these  pins  are  removed,  and  the  cylinder  rises  then 
bj  means  of  the  two  counter  weights,  not  shown  in  the  figures. 

The  operation  of  the  machine  is  as  follows ; — ^The  edge  or  end  of  the  leather  being 
secured  to  the  cylinder  d,  the  leather  itself  having  the  direction  upon  the  table  shown 
in^^f.  865,  and  the  bar,  r,  its  proper  proportion  over  the  knife,  the  edge  begins  to  enter 
in  this  position  into  the  leather,  while  tlie  cylinder,  d,  is  moved  by  the  handle  or  winch, 
and  the  piece  gets  split  betwixt  the  blade  and  the  roller  d.  When  the  other  end  of  the 
leather,  k,  advances  to  the  knife,  there  is,  consequently,  one  half  of  the  leather  split; 
the  skin  is  to  be  then  rolled  off  the  cylinder  d;  it  is  turned;  the  already  split  half,  or 
the  end  of  the  leather  k,  is  made  fast  into  the  wood  of  the  cylinder,  and  the  other  half 
is  next  split ;  while  the  knife  now  acts  fi*om  below,  in  an  opposite  direction  to  what  it 
did  at  first 

That  the  unrolling  of  the  leather  from  the  cylinder,  d,  may  not  be  obstructed  by  the 
pinion  t,  the  stop-wedge  e{Jig8.  863,  864)  is  removed  from  the  teeth.  In  the  process  of 
splitting,  the  grain  side  of  the  leather  is  uppermost  and  is  therefore  cut  of  an  uniform 
thickness,  but  the  underside  varies  in  thickness  with  the  inequality  of  the  skin. 

The  quantity  of  leather  gloves  of  Foreign  production  exported  in  1850,  was  401,009 
pairs,  and  in  1851,  107,925  pairs.     See  Hides. 

Exports  of  Leather  of  British  Produce  and  Manufacture. 


Quantities. 

Declared  Value. 

£ 

JE 

1860. 

1851. 

1850. 

1861. 

32,205 

25,625 

181,737 

152,070 

81,124 

27,141 

18,821 

19,781 

1,619,463 

1,625,566 

284,847 

288,543 

— 

— 

123,960 

138,168 

Leather,  nnwrought  cwts. 
Wrought  viz.  gloves,  lbs. 
Of  other  sorts,  lbs.     . 

Saddlery  and  harness,  value  £ 

LEDUM  PELUSTRE  This  plant  is  employed  in  Russia  to  tan  the  skin  of  goats, 
ealyes,  and  sheep,  into  a  reddish  leather  of  an  agreeable  smell ;  as  also  in  the  prepara- 
tion of  the  oil  of  birch,  for  making  what  is  commonly  called  Russia  leather. 

LEGUMINE^  is  the  name  of  a  vegeto-alkali  supposed  to  exist  in  leguminous 
plants. 


LEMONS.    See  Citric  Acid,  and  Oils,  Essential. 

LEVIGATION  is  the  mechanical  process  whereby  hard  substances  are  reduced  to  a 
▼ery  fine  powder. 

LELJCITE  is  a  hard  Yesuvian  mineral,  consisting  of  silica,  54 ;  alumina,  23 ;  pot- 
ash, 23. 

LEUCINE  is  a  white  crystalline  substance  produced  by  acting  upon  flesh  with  sulphu- 
ric acid. 

LEWIS  is  the  name  of  one  kind  of  shears  used  in  cropping  woollen  cloth. 

LIAS  is  a  fine-grained  argillaceous  limestone,  whose  geological  position  is  under  the 
oolite ;  it  is  the  proper  lithographic  stone. 

LIBAVIUS,  LiquoR  of,  is  the  bichloride  of  tin,  piepared  by  dissolving  that  metal,  with 
the  aid  of  heat,  in  aqua  regiay  or  by  passing  chlorine  gas  through  a  solution  of  muriate 
of  tin  till  no  more  gas  be  absorbed,  evaporating  the  solution,  and  setting  it  aside  to  crys- 
tallize. The  anhydrous  bichloride  is  best  prepared  by  mixing  four  parts  of  corrosive  sub- 
limate with  one  part  of  tin,  previously  amalgamated  with  just  so  much  mercury  as  to 
render  it  pulverizable ;  and  by  distilling  this  mixture  with  a  gentle  heat.  A  colorless 
fluid,  the  dry  bichloride  of  tin,  or  the  proper  fuming  liquor  of  Libavius,  comes  over. 
When  it  is  mixed  with  one  third  of  its  weight  of  water  it  becomes  solid.  The  first 
bichloride  of  tin  is  used  in  calico-printing. 

LICHEN.    See  Archil. 

LIGNEOUS  MATTER  is  vegetable  fibre.     See  Fibrous  Matter. 

LIGNITE  is  one  of  the  most  recent  geological  formations,  being  the  carbonaceous 
remains  of  forest  trees.  From  this  substance,  as  found  in  the  neighborhood  of  Cologne,- 
the  brown  colors,  called  timber  and  earth  of  CologiiBj  are  prepared. 

LILACH  DYE.     See  Calico-printing  and  DYEiNr+, 

LIMESTONE  (Ca/cairc,Fr.;ira/4fet7etn, Germ.),  may  be  classed  under  the  following 
heads : — 

1.  Calcareous  spar  occurs  in  colorless  crystals  or  crystalline  masses ;  dissolves  with 
effervescence  in  muriatic  acid ;  is  scratched  by  soft  iron,  but  not  by  the  nail ;  specific 
gravity  2*7 ;  loses  46  per  cent,  by  the  expulsion  of  carbonic  acid,  and  calcines  into  quick- 
lime. 

2.  Calcsinter,  or  stalactitic  carbonate  of  lime,  called  also  concretionary  limestone,  because 
formed  of  zones  more  or  less  undulated,  and  nearly  parallel.  These  zones  have  a  fibrous 
structure,  arising  from  the  successive  deposites  of  the  crystalline  limestone  from  its  sol- 
vent water.  The  long  conical  pieces  called  stalactites,  show  fibres  converging  to  the 
axis.  The  tubercular  consists  of  irregular  lumps  often  sprinkled  over  with  small  crystals, 
and  associated  so  as  to  exhibit  the  appearance  of  cauliflower.  The  stratiform,  commonly 
called  stalagmite,  or  alabaster  limestone,  represents  zones  not  concentric,  but  spread  out, 
waving,  and  parallel ;  its  texture  is  sometimes  lamellar,  and  sometimes  fibrous.  These 
waving  strata  are  distinguishable  from  one  another  by  their  diflferent  densities,  and  by 
their  degrees  of  translucency.  This  stalagmitic  mass  bears  the  name  of  oriental  alabaster, 
when  it  is  reddish-yellow  with  distinct  zones,  and  is  susceptible  of  a  fine  polish.  Stalac- 
tites are  formed  in  the  large  excavations  of  calcareotc  rocks.  The  water  percolating 
down  through  them,  and  dropping  from  the  roofs  of  the  caverns,  is  usually  charged  with 
carbonate  of  lime  held  in  suspension  by  an  excess  of  carbonic  acid.  The  exposure  to  air, 
the  motion,  and  the  consequent  diminution  of  pressure,  cause  the  precipitation  of  the  car- 
bonate of  lime  in  the  solid  state.  Each  drop  of  water,  on  falling  through  the  vault,  aban- 
dons a  small  film  of  limestone,  which  enlarges  by  degrees,  and  forms  either  a  cylinder  or 
solid  mass.  This  alabaster  difiers  from  marble  in  its  parallel  and  waving  layers,  and  its 
famt  degree  of  transparency. 

This  alabaster  serves  for  the  decoration  of  public  buildings,  and  is  occasionally  intro- 
duced  into  certain  pieces  of  furniture.  The  fine  Egyptian  alabaster  was  anciently 
brought  from  the  mountains  of  the  Thebaid,  between  the  Nile  and  the  Red  Sea,  near 
a  town  called  Alabastron,  whence  probably  the  name.  Very  fine  red  alabaster,  of  great 
exha    ted^*^  *^  °"^  ^^  ^^  ^^^  quarries  of  Montmartre,  but  the  stock  was  soon 

The  incrusting  concretionary  limestone  differs  little  from  the  preceding  except  in 
ine  rapidity  of  its  formation,  and  in  being  moulded  upon  some  body  whose  shape  it 
assumes.  Ihese  deposites  from  calcareous  springs,  form  equaUy  on  vegetable  bodies,  on 
siones,  metals  mthm  pipes  of  cast  iron,  wood,  or  lead.  The  incrustations  on  vegetable 
ana  animal  substances  are  vulgarly  caUed  petrifactions,  as  the  organic  fibres  are  replaced 
oy  sione.  une  of  the  most  curious  springs  of  this  nature  is  at  the  baths  of  Saint  PhiUp, 
«l»Lct  ^^\-  u"®  *?®  ^^^^"^  ^^"^^  ^^  *l"«st  a  boiUng  state,  over  an  enormous  mass  oi 
hlro  K,  ^1  i  **  i"^^  produced.  The  carbonate  of  lime  seems  to  be  held  in  solution 
vIL^l  *u  Phureted  hydrogen,  which  flies  off"  when  the  water  issues  to  the  day.  Dr. 
of  arirLV?  advantage  of  this  property  of  the  spring,  to  obtain  basso-reUevo  figures 
Of  great  whiteness  and  soUdity.     He  makes  use  of  sulphS-  moulds.  / 


T> 


LIMESTONE. 


LIMESTONE. 


73 


ti 


i^t 


|i 


ill 


Calcareous  tuf  consists  of  similar  incrustations  made  by  petrifying  rirulets  running 
over  mud,  sand,  vei^etable  remains,  &,c.  It  is  porous,  even  cellular,  somewhat  soft, 
impure,  and  of  a  dirty  gray  color.  Its  surface  is  wavy,  rough,  and  irregular.  These 
incrustations  or  deposites  are,  however,  sometimes  so  abundant,  and  the  resulting  stony 
matters  so  hard  that  buildings  may  be  constructed  with  them.  The  stone  with  which  the 
town  of  Pasti,  in  Italy,  is  built  has  been  called  pipe-stone  by  the  Italians ;  and  it  has  ap- 
piirently  derived  its  origin  from  incrustations  upon  large  reeds. 

The  travertinOy  which  served  to  construct  all  the  monuments  of  Rome,  appears  to 
have  been  formed  by  the  deposites  of  the  Anio  and  the  solfatara  of  Tivoli.  The  temples 
of  Paestum,  which  are  of  extreme  antiquity,  have  been  built  with  a  travertino  formed 
by  the  sediment  of  the  waters  which  still  flow  in  this  territory.  All  these  stones  acquire 
great  hardness  in  the  air,  and  M.  de  Breislak  thinks  that  it  is  to  the  happy  union  of 
travertino  and  pouzzolana  in  the  same  spot,  that  the  monuments  of  Rome  owe  their  great 
solidity. 

Spongy  limeslone,  usually  called  jlgaric  mineral^  stone  marrow,  &c.,  belongs  to  this 
kind  of  formation.  It  has  a  very  white  color,  a  very  fine  grain,  is  soft  to  the  touch,  very 
tender,  and  light  enough  to  float  for  an  instant  on  water.  It  occurs  in  rather  thin  layers, 
in  the  crevices  of  calcareous  rocks,  and  is  so  common  in  Switzerland  as  to  be  employed 
for  whitening  houses. 

3.  Compact  limestone,  is  of  a  grain  more  or  less  fine,  does  not  polish,  nor  afford  large 
blocks  free  from  fissures,  has  a  conchoidal,  or  uneven  scaly  fracture.  Colors  very 
various.  Its  varieties  are ;  a.  The  sub-lamellar,  compact,  with  some  appearance  of  a 
foliated  texture,  b,  Compact  fine-grained  limestone,  the  zechstein  of  the  Germans,  to 
which  M.  Brongniart  refers  the  lithographic  stone  in  his  classification  of  rocks  (Dictum' 
nairt  des  Sciences  Naturelles),  but  the  English  geologists  place  the  locality  of  tht  iamoug 
lithographic  quarry  of  Solenhofen  much  higher  in  the  plane  of  secondary  superposition. 
Its  fracture  is  conchoidal ;  color  from  gray  to  whitish ;  c.  Compact  common  limestone. 
Grain  of  middle  size ;  earthy  aspect ;  uneven  fracture ;  perfectly  opaque ;  color, 
whitish  to  pale  gray,  yellow,  or  reddish.  The  limestones  of  the  Jura  formation  are 
referred  to  this  head,  as  well  as  most  of  those  interspersed  among  the  coal  strata,  d.  The 
coarse  compact,  or  Cornbrash ;  texture  somewhat  open,  earthy  aspect,  rough  to  the  touch, 
ragged  fracture,  color  yellow,  gray,  or  dirty  red.  e.  Compact  cellular,  the  Rauchekalk 
and  Holekalk  of  the  Germans,  on  account  of  the  numerous  holes  or  caverns  distributed 
through  it. 

4.  Oolite  or  roe-stone. — It  consists  of  spherical  grains  of  various  size,  from  a  millet 
seed,  to  a  pea,  or  even  an  egg ;  texture  compact ;  fracture  even  ;  colors,  whitish,  yellow, 
gray,  reddish,  brownish.  The  larger  bails  have  almost  always  a  foreign  body  for  their 
centre  or  nucleus, 

5.  Chalk ;  texture  earthy ;  grains  fine,  tender,  friable ;  colors  white,  grayish,  or  pale 
yellowish. 

6.  Coarse-grained  limestone ;  an  earthy  texture,  in  large  particles,  often  loose ;  frac- 
ture foliated,  uneven ;  color  pale  and  dirty  yellow.  Coarse  lias  has  been  referred  to  this 
head. 

7.  Marly  limestone  ;  lake  and  fresh  water  limestone  formation ;  texture  fine-grained, 
more  or  less  dense ;  apt  to  cnimble  down  in  the  air ;  color  white  or  pale  yellow ;  fracture 
rough-grained,  sometimes  conchoidal ;  somewhat  tenacious.    Texture  occasionally  cavern 
ous ;  with  cylindrical  winding  cavities.     This  true  limestone  must  not  be  confounded  with 
the  lime-marl,  composed  of  calcareous  matter  and  clay. 

8.  Silicious  limestone;  of  a  compact  texture;  scratching  steel,  and  scratched  by  it ; 
leaves  a  silicious  residuum  after  the  action  of  muriatic  acid. 

9.  Calp ;  texture  compact ;  fine-grained ;  schistose  structure ;  bard,  as  the  pre- 
ceding ;  not  burning  into  quicklime,  affording  to  dilute  muriatic  acid  a  copious  residuum 
of  clay  and  silica ;  color  blackish ;  found  in  beds  in  the  transition  district  near 
Dublin. 

10.  Lucullite  or  stinkstone ;  texture  compact  or  sub-lamellar,  color  gr»yish ;  emits  the 
smell  of  sulphureted  hydrogen  by  friction  or  a  blow.  It  occurs  at  Assynt,  in  Sutherland- 
shire  ;  in  Derbyshire  ;  counties  of  Kilkenny,  Cork,  and  Galway. 

\l.  Bituminous  limestone;  black  or  blackish  color;  diffusing  by  the  action  of  fire  a 
bituminous  odor,  and  becoming  white. 

Of  all  common  limestones  the  purity  may  most  readily  be  determined  by  the  quantity 
of  carbonic  acid  which  is  evolved  during  their  solution  in  dilute  nitric  or  muriatic  acid. 
Perfect  carbonate  of  lime  loses  in  this  way  46  per  cent. ;  and  if  any  particular  limestone 
loses  only  23  per  cent.,  we  may  infer  that  it  contains  only  one  half  its  weight  of  calcareous 
carbonate.  This  method  is  equally  applicable  to  marls,  which  are  mixtures  in  various 
proportions  of  carbonate  of  lime,  clay,  and  sand,  and  may  all  be  recognised  by  their  effer- 
vescing with  acids. 

The  chief  use  of  calcareous  stones  is  for  procuring  quicklime  by  calcination  in  propel 


fumaces;  and  they  are  all  adapted  to  this  purpose  provided  they  are  not  mixed  with  too 
large  a  proportion  of  sand  and  ferruginous  clay,  whereby  they  acquire  a  vitrescent 
texture  in  a  high  heat,  and  will  not  burn  into  lime.    Limestone  used  to  be  calcined  in 
a  very  rude  kiln,  formed  by  enclosing  a  circular  space  of  10  or  15  feet  diameter,  by  rude 
stone  walls  4  or  5  feet  high,  and  filling  the  cylindrical  cavity  with  alternate  layers  of 
turf  or  coal   and  limestone  broken  into  moderate  pieces.     A  bed  of  brushwood  was 
usually  placed  at  the  bottom,  to  facilitate  the  kindling  of  the  kiln.     Whenever  the  com- 
bustion was  fairly  commenced,  the  top,  piled  into  a  conical  form,  was  covered  in  with 
sods,  to  render  the  calcination  slow  and  regular.    This  method  being  found  relatively 
inconvenient  and  ineffectual,  was  succeeded  by  a  permanent  kiln  built  of  stones  or  brick- 
work, in  the  shape  of  a  truncated  cone  with  the  narrow  end  undermost,  and  closed  at 
bottom  by  an  iron  grate.     Into  this  kiln,  the  fuel  and  limestone  were  introduced  at  the 
top  in  alternate  layers,  beginning  of  course  with  the  former ;  and  the  charge  was  either 
allowed  to  bum  out,  when  the  lime  was  altogether  removed  at  a  door  near  the  bottom  or 
the  kiln  was  successively  fed  with  fresh  materials,  in  alternate  beds,  as  the  former  supply 
sunk  down  by  the  calcination,  while  the  thoroughly  burnt  lime  at  the  bottom  was  succes- 
sively raked  out  by  a  side  door  immediately  above  the  grate.     The  interior  of  the  lime  kiln 
has  been  changed  of  late  years  from  the  conical  to  the  dliptical  form ;  and  probably  the 
best  is  that  of  an  egg  placed  with  its  narrow  end  undermost,  and  truncated  both  above 
and  below ;  the  ground  plot  or  bottom  of  the  kiln  being  compressed  so  as  to  give  an 
elliptical  section,  with  an  eye  or  draft-hole  towards  each  end  of  that   ellipse      A  kiln 
thus  arched  in  above  gives  a  reverberatory  heat  to  the  upper  materials,  and  also  favors 
Iheir  falling  freely  down  in  proportion  as  the  finished  lime  is  raked  out  below;  advan- 
tages which  the  conical  form  does  not  afford.    The  size  of  the  draft-notes  for  extracting 
the  quicklime,  should  be  proportionate  to  the  size  of  the  kiln,  in  order  to  admit  a  suffi- 
cient current  of  air  to  ascend  with  the  smoke  and  flame,  which  is  found  to  facilitate 
the  extrication  of  the  carbonic  acid.     The  kilns  are  called  perpetual,  because  the  operation 
w  cairied  on  continuously  as  long  as  the  building  lasts ;  and  draw^ilns,  from  the  mode  of 
discharging  them  by  raking  out  the  lime  into  carts  placed  against  the  draft-holes.     Three 
bushels  of  calcined  limestone,  or  lime-shells,  are  produced  on  an  average  for  every  bushel 
of  coals  consumed.     Such  kilns  should  be  built  up  against  the  face  of  a  cliff,  so  that  easy 
access  may  be  gained  to  the  mouth  for  charging,  by  making  a  sloping  cart  road  to  the  too 
w  the  bank,  '^ 


■-•ft     :«•»*•    3a,    '-^i^ 


74 


LIMESTONE. 


LIQUATION. 


7S 


2^ff-  167,  868,  869,  8T0,  represent  the  lime-kiln  of  Rudersdorf  near  Berlin,  upv.a  the 
continuous  plan,  excellently  constmcted  for  et-onoraizing  fuel.  It  is  triple,  and  yields  a 
threefold  product.  Fiff.  869,  is  a  view  of  it  as  seen  from  above;  Jig.  87(),  the  elevation 
and  general  appearance  of  one  side ;  Ji^.  867.  a  vertical  section,  and  Jig.  868,  the  ground 
plan  in  the  line  a  bod  of/^.  867.  The  inner  shaft  Jig.  868.  has  the  form  of  two  tinincated 
cones,  with  their  larger  circular  ends  applied  to  each  other ;  it  has  the  greatest  width  at 
the  level  of  the  fire-door  b,  where  it  is  8  feet  in  diameter ;  it  is  narrower  below  at  the 
discharge  door,  and  at  the  top  orifice,  where  it  is  about  6  feet  in  diameter.  The  interior 
wall  d,  of  the  upper  shaft,  is  built  with  hewn  stones  to  the  height  of  38  feet^  and  below 
that  for  26  feet,  with  fire-bricks  d'  d',  laid  stepwise.  This  inner  wall  is  surrounded  with 
a  mantle  e,  of  limestone,  but  between  the  two  there  is  a  small  vacant  space  of  a  few 
inches  filled  with  ashes,  in  order  to  allow  of  the  expansion  of  the  interior  with  heat 
taking  place  without  shattering  the  mass  of  the  building. 

The  fire  grate,  b,  consists  of  fire-tiles,  which  at  the  middle,  where  the  single  pieces 
press  together,  lie  upon  an  arched  support /*.  The  fire-door  is  also  arched,  and  is  secured 
by  fire-tiles,  g  is  the  iron  door  in  front  of  that  orifice.  The  tiles  which  form  the  grata 
have  3  or  4  slits  of  an  inch  wide  for  admitting  the  air,  which  enters  through  the  canal  A. 
The  under  part  of  the  shaft  from  the  fire  to  the  hearth  is  7  feet,  and  the  outer  enclosing 
wall  is  constructed  of  limestone,  the  lining  being  of  fire-bricks.  Here  are  the  ash-pit  t, 
the  discharge  outlet  a,  and  the  canal  k,  in  front  of  the  outlet.  Each  ash-pit  is  shut  with 
an  iron  door,  which  is  opened  only  when  the  space  i  becomes  filled  with  ashes.  These 
indeed  are  allowed  to  remain  till  they  get  cool  enough  to  be  removed  without  incon- 
Tenience. 

The  discharge  outlets  are  also  furished  with  iron  doors,  which  are  opened  only  for 
taking  out  the  lime,  and  are  carefully  luted  with  loam  during  the  burning.  The  outei 
walls  /  m  n  of  the  kiln,  are  not  essentially  necessary,  but  convenient,  because  they  afibrd 
room  for  the  lime  to  lie  in  the  lower  floor,  and  the  fuel  in  the  second.  The  several  stories 
are  formed  of  groined  arches  o,  and  platforms  j>,  covered  over  with  limestone  slabs.  In 
the  third  and  fourth  stories  the  workmen  lodge  at  night.  See  Jig.  870.  Some  enter  their 
apartments  by  the  upper  door  q  ;  others  by  the  lower  door  s.  r  is  one  of  the  chimneys  for 
the  several  fire-places  of  the  workmen,    t  uv  are  stairs. 

As  the  limestone  is  introduced  at  top,  the  mouth  of  the  kiln  is  surrounded  with  a 
strong  iron  balustrade  to  prevent  the  danger  of  the  people  tumbling  in.  The  platform  is 
laid  with  rails  u",  for  the  wagons  of  limestone,  drawn  by  horses,  to  run  upon,  x  is 
another  rail-way,  leading  to  another  kiln.  Such  kilns  are  named  after  the  number  of  their 
fire-doors,  single,  twofold,  threefold,  fourfold,  &c. ;  from  three  to  five  being  the  most  usual. 
The  outer  form  of  the  kiln  also  is  determined  by  the  number  of  the  furnaces ;  being  a 
truncated  pyramid  of  equal  sides  ;  and  in  the  middle  of  each  alternate  side  there  is  a  fire, 
place,  and  a  discharge  outlet.  A  cubic  foot  of  limestone  requires  for  burning,  one  and  five 
twelfths  of  a  cubic  foot  of  wood,  and  one  and  a  half  of  turf. 

When  the  kiln  is  to  be  set  in  action,  it  is  filled  with  rough  limestones,  to  the  height 
c  D,  or  to  the  level  of  the  firing;  a  wood  fire  is  kindled  in  «,  and  kept  up  till  the  lime  is 
calcined.  Upon  this  mass  of  quicklime,  a  fresh  quantity  of  limestones  is  introduced,  not 
thrown  in  at  the  mouth,  but  let  down  in  buckets,  till  the  kiln  be  quite  fuU ;  while  over 
the  top  a  cone  of  limestones  is  piled  up,  about  4  feet  high.  A  turf-fire  is  now  kindled 
m  the  furnaces  b.  Whenever  the  upper  stones  are  well  calcined,  the  lime  under  the 
fire-level  is  taken  out,  the  superior  column  falls  in,  a  new  cone  is  piled  up,  and  the 
process  goes  on  thus  without  interruption,  and  without  the  necessity  of  once  putting  a  fire 
into  a;  for  in  the  space  c  b,  the  lime  must  be  always  well  calcined.  The  discharge  of 
lime  takes  place  every  12  hours,  and  it  amounts  at  each  time  in  a  threefold  kiln,  to  from 
20  to  24  Prussian  tonnes  of  6  imperial  bushels  each ;  or  to  130  bushels  imperial  upon 
the  average.  It  is  found  by  eyperience,  that  fresh-broken  limestone  which  contains  a 
little  moisture,  calcines  more  readily  than  what  has  been  dried  by  exposure  for  some 
time  to  the  air ;  in  consequence  of  the  vapor  of  water  promoting  the  escape  of  the 
carbonic  acid  gas ;  a  fact  well  exemplified  in  distilling  essential  oils,  as  oil  of  tur- 
pentine and  naptha,  which  come  over  with  the  steam  of  water,  at  upwards  of  100  degrees 
F.  below  their  natural  term  of  ebullition.  Six  bushels  of  Rudersdorf  quickhme  weigh 
from  280  to  306  pounds. 

When  coals  are  used  for  fuel  in  a  well-constructed  perpetual,  or  draw  kiln,  about  ] 
measure  of  them  should  suffice  for  4  or  5  of  limestone. 

The  most  extensive  employment  of  quicklime  is  in  agriculture,  on  which  subject  in- 
structive details  are  given  in  Loudon's  Encyclopaedias  of  Agriculture  and  Gardening. 

Quicklime  is  employed  in  a  multitude  of  preparations  subservient  to  the  arts ;  for 
clarifying  the  juice  of  the  sugar-cane  and  the  beet-root;  for  purifying  coal  gas;  for 
rendering  the  potash  and  soda  of  commerce  caustic  in  the  soap  manufacture,  and  in  the 
bleaching  of  linen  and  cotton ;  for  purifying  animal  matters  before  dissolving  out  their 
gelatine ;  for  clearing  hides  of  their  hair  in  tanneries ;  for  extracting  the  pure  volatile 
alkali  from  muriate  or  sulphate  of  ammonia  ;  for  rendering  confined  portions  of  air  very 


dry;  for  stopping  the  leakage  of  stone  reservoirs,  when  mixed  with  clay  and  thrown 
into  the  water ;  for  making  a  powerful  lute  with  white  of  egg  or  serum  of  blood;  for 
preparing  a  depilatory  pommade  with  sulphuret  of  arsenic,  <fec.  Lime  water  is  used  in 
medicine,  and  quicklime  is  of  general  use  in  chemical  researches.  Next  to  agriculture 
the  most  extensive  application  of  quicklime  is  to  Mortar  Cements,  which  see. 
LINEN.     See  Flax,  and  Textile  Fabrics. 

Linen  distinguished  from  cotton. — Cotton  maybe  distinguished  from  linen  or  flax  by 
immersing  the  former,  well  washed  and  dried,  for  about  a  minute  in  strong  sulphuric 
acid.  It  IS  then  to  be  withdrawn  and  washed  with  water  containing  a  little  alkali. 
The  cotton  will  dissolve  as  a  gummy  mass,  while  the  linen  will  retain  its  thready 
texture. 

LINSEED  {Graine  de  Hit,  Fr. ;  Leinsame,  Germ.);  contains  in  its  dry  state,  11*265 
of  oil;  0.146  of  wax;  2.488  of  a  soft  resin;  0.550  of  a  coloring  resinous  matter; 
0-926  of  a  yellowish  substance  analogous  to  tannin ;  6-154  of  gum ;  15-12  of  vegetable 
mucilage;  1  48  of  starch  ;  2-932  of  gluten  ;  2.782  of  albumine  ;  10884  oisachcarine 
extractive  ;  44*382  of  envelopes,  including  some  vegetable  mucilage.  It  contains  also 
free  acetic  acid ;  some  acetate,  sulphate,  and  muriate  of  potash,  phosphate  and  sulphate 
of  lime;  phosphate  of  magnesia;  and  silica.     See  Oils,  Unctuous. 

LINSEED  AND  FLAXSEED.  Imported,  for  home  consumption,  in  1850, 
608,984  quarters ;  in  1851,  630,471  qrs., ;  dutyfree. 

LINSEED  OIL,  drying  without  heat.  When  linseed  oil  is  carefully  agitated  with 
vinegar  of  lead  (tribasic  acetate  of  lead)  and  the  mixture  allowed  to  clear  by  settling, 
a  copious  white  cloudy  precipitate  forms,  containing  oxide  of  lead,  whilst  the  raw  oU 
is  converted  into  a  drying  oil  of  a  pale  straw  color,  forming  an  excellent  varnish, 
which  when  applied  in  thin  layers,  dries  perfectly  in  twenty-four  hours.  It  contains 
from  four  to  five  per  cent,  of  oxide  of  lead  in  solution.  The  following  proportions 
appear  to  be  the  most  advantageous  for  its  preparations. 

In  a  bottle  containing  4*  pints  of  rain  water,  18  ounces  of  neutral  acetate  of  lead  are 
placed,  and  when  the  solution  is  complete,  18  ounces  of  litharge  in  a  very  fine  powder 
are  added ;  the  whole  is  then  allowed  to  stand  in  a  moderately  warm  place,  frequentU' 
agitating  it  to  assist  the  solution  of  the  litharge.  This  solution  may  be  considered  as 
complete  when  no  more  small  scales  are  apparent.  The  deposit  of  a  shining  white 
color  (sexbasic  acetate  of  lead)  may  be  saparated  by  filtration.  This  conversion  of 
the  neutral  acetate  of  lead  into  vinegar  of  lead,  by  means  of  litharge  and  water,  is 
effected  in  about  a  quarter  of  an  hour,  if  the  mixture  be  heated  to  ebullition.  "SVhen 
heat  is  not  applied,  the  process  will  usually  take  three  or  four  days.  The  solution  of 
vinegar  of  lead,  or  tribasic  acetate  of  lead,  thus  formed,  is  sufficient  for  the  preparation 
of  22ib8.  of  drying  oil  For  this  purpose,  the  solution  is  diluted  with  an  equal  volume 
of  ram  water,  and  to  it  is  gradually  added,  with  constant  agitation,  22lbs.  of  oil,  with 
which  18  ounces  of  litharge  have  previously  been  mixed. 

When  the  points  of  contact  between  the  lead  solution  and  the  oil  have  been  fre- 
quently renewed  by  agitation  of  the  mixture  three  or  four  times  a  day,  and  the  mixture 
allowed  to  settle  in  a  warm  place,  the  limpid  straw-colored  oil  rises  to  the  surface, 
leaving  a  copious  whitish  deposit  The  watery  solution  rendered  clear  by  filtration, 
contains  intact  all  the  acetate  of  lead  first  employed,  and  may  be  used  in  the  next 
operation,  after  the  addition  to  it  as  before  of  18  ounces  of  lithai-ge. 

By  filtration  through  paper  or  cotton  the  oil  may  be  obtained  as  limpid  as  water 
and  by  exposure  to  the  light  of  the  sun  it  may  also  be  bleached. 

Should  a  drying  oil  be  required  absolutely  free  fi-om  lead,  it  may  be  obtained  by  the 
addition  of  dilute  sulphuric  acid  to  the  above,  when,  on  being  allowed  to  stand,  a 
deposit  of  sulphate  of  lead  will  take  place,  and  the  clear  oil  may  be  obtained  free  from 
all  trace  of  lead. 

Lint  for  surgery,  has  been  made  the  subject  of  a  patent  by  Mr.  Thomas  Ross,  of 
Ooleman  Street,  which  consists  in  the  employment  of  peculiarly  constructed  scrapers 
tor  braiding  the  surface  of  the  linen  cloth,  and  producing  a  pile  or  nap  upon  it  The 
scrapers  are  worked  by  a  rotary  motion. 

Instead  of  rotary  scrapers,  a  reciprocating  pendulous  movement  is  sometimes  applied 
to  a  single  scraper.  Chisel-formed  blades  are  claimed  by  the  patentee  as  scrapers  for 
raising  the  pile,  by  working  with  the  bevel  edges  forwards,  so  as  to  scrape  and  not  to 
cut  the  fabric.  He  has  in  the  rotary  form  a  ledge  or  bed  concentric  with  the  axis  of 
tne  scraper,  which  he  also  claims ;  both  of  which  seem  to  be  serviceable.     The  details 

TT^^^^!J,^J,y  ^eseenin  Newton's  Journal,  xxxvil  301. 

laiJbAUON  (Eag.  and  Fr. ;  Saigerung,  Germ.);  is  the  process  of  sweating  out  by 
a  ^gulated  heat  from  an  alloy  an  easily  fusible  metal  from  the  interstices  of  a  metal 
aimcuit  ot  lusion.  Lead  and  antimony  are  the  metals  most  commonly  subjected  to 
uquaiion ;  the  former  for  the  purpose  of  carrying  off  by  a  superior  affinity  the  silver 


|!i      1.1. 


78 

present 

conside 

figs. 


LIQUATION. 


b« 


in  any  complex  alloy,  a  subject  discussed  under  Silver  ;  the  latter  will 

red  here,  as  referred  to  from  the  article  Antimony. 

871,  872,  873  represent  the  celebrated  antimonial  liquation  furnaces  of  Malbose, 

in  the  department  of  Ardeche,  in  France.     Fig. 

C   871     /TW/M  ^*^^  ^^  *  ground  plan  taken  at  the  level  of  the 

I  ...A-/mWM  draught  holes  g  g,  jig.  872,  and  of  the  dotted  line 

I  'V^.i/:/,  ..  Y..:l  ^  y .  ^^^  g,y2  is  a  vertical  section  through  tb» 


dotted  Une  a  b,  of  .^g.  871  ;  and  jig.  873  is  a 
vertical  section  through  the  dotted  line  c  d  of 
fig,  871.     In  the  three  figures,  the  same  letters 
denote  like  objects,    a  6  c  are  three  grates  upon 
the  same  level  above  the  floor  of  the  works,  4| 
feet  long,  by  10|  inches  broad ;  between  which 
are  two  rectangular  galleries,  d  «,  which  pass 
transversely  through  the  whole  furnace,  and  lie 
at  a  level  of  12  inches  above  the  ground.     They 
are  separated  by  two  walls  from  the  three  fire-places.     The  walls  have  three  ope n- 
ines  fz  K  alternately  placed  for  the  flames  to  play  through.     The  ends  of  these  galleries 
are  shut  in  with  iron  doors  i  t,  containing  peep  holes.    In  each  gallery  are  two  conical 
cast-iron  crucibles  fc  fc,  into  which  the  eliquaiing  sulphuret  of  antimony  drops.    Their 
heic'ht  is  from  12  to  14  inches,  the  width  of  the  mouth  is  10  inches,  that  of  the  bottom  is 
6,  a'kd  the  thickness  four  tenths  of  an  inch.     They  are  coaled  over  with  fire-clay,  to  pre- 
vent  the  sulphuret  from  acting  upon  them ;  and  they  stand  upon  cast-iron  pedestals  with 
nroiectins  ears,  to  facilitate  their  removal  from  the  gallery  or  platform.     Both  ol  these 
galleries  are  lined  with  tiles  of  fire-clay  1 1,  which  also  serve  as  supports  to   he  vertical 
Uquation  tubes  m  tn,  made  of  the  same  clay.     The  tiles  are  somewhat  curved  towards  the 
middle,  for  the  purpose  of  receiving  the  lower  ends  of  these  tubes,  and  have  a  small  hole 
»t  n,  through  which  the  liquid  sulphuret  flows  down  into  the  crucible.  ,^  .     , 

The  liquation  tubes  are  conical,  the  internal  diameter  at  top  being  10  inches,  at 
bottom  8  ;  the  length  fully  40  inches,  and  thethicknesssix  tenths  of  an  mch.  They  have 
at  their  lower  ends  notches  or  slits  o,  Jig-  S'?^,  from  3  to  5  inches  long,  which  look  out- 
wards, to  make  them  accessible  from  the  front  and  back  part  of  the  furnaces  through 
small  conical  openings  p  p,m  the  walls.  These  are  closed  during  the  operation  with 
clay  stoppers,  and  are  opened  only  when  the  gangue,  rubbish,  and  cinders  are  to  be  raked 
out.  The  liquation  tubes  pass  across  the  arch  of  the  furnace  q  9,  the  space  of  the  arch 
being  wider  than  the  tubes  ;  they  are  shut  in  at  top  with  fire-covers  r  r.  s  s,  the  middle 
part  of  the  arch,  immediately  under  the  middle  grate,  is  barrel-shaped  so  that  both 
krches  are  abuttk  together.  The  flames,  after  playing  round  about  the  sides  of  the 
Uquation  tubes,  pass  off  through  three  openings  and  flues  into  the  chimney  t,  a^ut  13 
feet  high;  «  being  the  one  opening,  and  v  the  two  others,  which  are  provided  with 
register  plates.  In  front  of  the  furnace  is  a  smoke  flue  ir,  to  carry  oflf  the  sulphureous 
vapors  exhaled  during  the  clearing  out  of  the  rubbish  and  slag ;  another,  x,  begins 
0VCTVV,at  the  top  of  the  tubes;  a  wall  z,  separates  the  smoke  flue  into  halves  so 
that  the  workmen  upon  the  one  side  may  not  be  incommoded  by  the  fumes  of  the  other. 
This  wall  connects  at  the  same  time  the  front  flue  w  with  the  chimney  /.  a  o  and 
h'  b'  are  iron  and  wooden  bearer  beams  and  rods  for  strengthemng  the  smoke-tlue.  tc 
arc  arches  upon  both  sides  of  the  furnace,  which  become  narrower  firom  without  mwards, 


LIQUEURS.  77 

are  arches  upon  both  sides  of  the  furnace,  which  become  narrower  from  without  inwards, 
and  are  closed  with  well-fitted  plates  d  d.  They  serve,  in  particular  circumsiances, 
to  allow  the  interior  to  be  inspected,  and  to  see  if  either  of  the  liquation  furnaces  be  out 
of  order. 

Each  tube  being  charged  with  about  500  lbs.  of  the  antimonial  ore,  previously 
warmed  upon  the  roof  of  the  furnace,  in  a  short  time  the  sulphuret  of  a  blue  color 
begins  to  flow  out  Whenever  the  liquation  ceases,  the  cinders  are  raked  out  by  the 
side  openings,  and  the  tubes  are  charged  afresh.  The  luted  iron  crucibles  are  suffered 
to  become  three-fourths  full,  are  then  drawn  out  from  the  galleries,  left  to  cool,  and 
emptied.  The  ingots  weigh  about  85  pounds.  The  charging  is  renewed  every  three 
houre,  and  when  the  process  is  in  good  train,  100  lbs.  of  sulphuret  of  antimony  are 
obtained  every  hour.  The  average  duration  of  the  tubes  is  3  weeks,  though  in  some 
oases  it  may  be  40  days.  The  product  from  the  ore  is  from  40  to  50  per  cent  The 
above  plan  of  operation  is  remarkable  for  the  small  consumption  of  fuel,  the  economy 
of  labor,  and  the  complete  exhaustion  of  the  ore, 

LIQUEURS,  LIQUORISTE  ;  names  given  by  the  French  to  liquors  compounded  of 
alcohol,  water,  sugar  and  different  aromatic  substances;  and  to  the  person  who  com- 
pounds them.     I  shall  insert  here  a  few  of  their  most  approved  recipes. 

Infusion  of  the  peels  of  fruits.— The  outer  skin  pared  off  with  a  sharp  knife,  is  to  be 
dropped  into  a  hard  glazed  jar,  containing  alcohol  of  34°  B.,  diluted  with  half  its  bulk 
of  water,  and  the  whole  is  to  be  transferred  into  well-corked  carboys.  After  an  infusion 
of  six  weeks,  with  occasional  agitation,  the  aromatized  spirit  is  to  be  distilled  off.  In 
this  way  are  prepared  the  liquors  of  cedrat,  lemons,  oranges,  limettes  (a  sort  of  sweet 
lemon),  ponclres  (the  large  citron),  bergamots,  Ac. 

Infusion  of  aromatic  «ecc?«.— These  niust  be  pounded,  put  into  a  carboy,  along  with 
alcohol  diluted  as  above,  infused  with  agitation  for  six  weeks,  and  then  distilled 

Infusion  of  aromatic  woods  are  made  in  the  same  way. 

The  liqaorist  should  not  bring  his  infusions  and  tinctures  into  the  market  till  six 
months  after  their  distillation. 

Liqueurs  have  different  titles,  according  to  their  mode  of  fabrication. 

Thlis  waters,  are  liquors  apparently  devoid  of  viscidity;  creains  and  oils  possess  it  in 
a  high  degree. 

Water  oi  cedrat,  is  made  by  dissolving  six  pounds  of  sugar  in  seven  quarts  of  water 
adding  two  quarts  of  spirit  of  cedrat,  and  one  of  spirit  of  citron.     Boil  the  whole 
for  a  minute,  and  filter  hot  through  a  proper  bag.     Set  it  for  a  considerable  time  aside 
in  a  corked  carboy,  before  it  be  bottled. 

Oil  or  cream  of  cedrat.— Take  eight  quarts  of  river  water,  two  of  spirits  of  cedrat, 
one  of  spirit  of  citron,  and  as  much  rich  syrup  as  is  necessary  to  give  the  mixture  an 
oily  consistence.  Stir  it  well  and  set  it  aside  in  carboys.  Should  it  be  at  all  clouded. 
It  must  be  filtered  till  it  be  perfectly  pellucid. 

Balm  of  Molucca,  is  made  by  infusing  for  ten  days,  in  a  carboy  capable  of  holding 
fully  four  gallons,  10  pounds  of  spirits  of  18°  B.,  4  pounds  of  white  sugar,  4  pounds  of 
nver  water,  4  drachms  of  pounded  cloves,  and  48  grains  of  pounded  mace.  The  mix- 
ture IP  to  be  shaken  3  or  4  times  daily,  colored  with  caramel  (burnt  sugar),  filtered  at 
the  end  of  ten  days,  and  set  aside  in  bottles. 

Tears  of  the  widow  of  Malabar,  are  compounded  with  the  preceding  quantity  of  spirits, 
sugar,  and  water,  adding  four  drachms  of  ground  cinnamon,  48  grains  of  cloves  and  a 
like  quantity  of  mace,  both  in  powder.     It  may  be  slightly  colored  with  caramel. 

Ih£  delight  of  the  Mandarins.— Take  spirit,  sugar  and  water,  as  above,  adding  4 
arachms  of  ams^nn  Chines  {Oingi),  as  much  ambretta  (seeds  of  the  hibiscus  abelmoschut, 

%l     .  ^^  powder ;  2  drachms  of  saflaower. 
f^V^y^  o//oi'c.— Take  spirits,  water,  and  sugar,  as  above.     Perfume  with  essence 

Jv^  T^^ '  ^'^^  *  ^^^^  F*^^  P^^^  ^^^  ^^^^  tincture  of  cochineal,  filter  and  bottle  up. 
o-rme  de  7nacarons.—Add  to  the  spirit,  sugar,  and  water  as  above,  half  a  pound  of 

A*«K  4«^  "^  '  '^^'*"<^''^<1  »nd  pounded;  cloves,  cinnamon,  and  mace  in  powder,  of 
eacn  4»  grains.     A  violet  tint  is  given  by  the  tinctures  of  turnsole  and  cochineal 

f^.\!*'T''r .  ^  ^°*^  *  ^^^^^  ^^^^^^  "e^r^y  ^"11  of  alcohol  of  trente-six  (34°  Baumel 
IhJlt  •  /'''  "''?"*^'  Portugal  oranges,  (Seville?)  and  let  them  infuse  for  15  days; 
v^ir  r- ""  *  '''*'^^>'  ^^  P^"''^^  ^^  «P"'i^s  <>f  1«°  ^-^  ^  Pounds  of  white  sugar,  and  4 
oS^^.  1/7?  '"'''•*"''•.  ^^^'^^  ^^^  ""g'^^  ^«  dissolved,  add  a  sufficient  quantity  of  the 
^muX^lZ  K  ?/'-^  ^^"^T'  ^^^"  'P^<^«  *^«  ^^°1«  ^ith  48  grains  of  cinnamon,  and 
i^fa««  di^fn  •  1  r?  J' '""  ^'^^^''-  ^^'^^y  introduce  an  ounce  of  ground  Brazil  wood,  and 
given  w"th  caramel''  agitating  3  or  four  times  daily.     A  pretty  deep  hue  ought  to  b« 

Synss  extract  of  wormwood,  is  compounded  as  follows:— 
lops  ot  the  absmthium  majus  4  pounds ; 
Ditto,  absinthium  minus  2  pounds  ;  / 


I 


1*' 

I 


I. 


78 


LITHOGRAPIUC  PRESSES. 


'of  each  a  few  grains  at  pleasure; 


Roots  ot  angelica, 

Calamus  aromaticus, 

Seeds  of  the  anUum  ChitUBy 

Leaves  of  the  dittany  of  Crete,  ^ 

Alcohol  of  20°  B.,  four  gallons  Imp.  ^       ,.    .,  .  n    a        a    ™«fff^A 

Macerate  these  substances  during  eight  days,  then  distil  by  a  gentle  fire  ;  draw  off  two 
gallons  of  spirits,  and  add  to  it  2  drachms  of  essential  oil  of  anise-seed.  The  two  gallon* 
left  in  the  still  serve  for  preparing  the  vulnerary  spirituous  water. 

Of  coloring  the  liqueurs.  .       n  /    ^i.         \     v-i.  ;- 

Yellow  is  given  with  the  yeUow  coloring  matter  of  sunflower  {earthamus),  which  w 

readily  extracted  by  water.  ,     , ., 

Fawn  is  given  by  caramel,  made  by  heating  ground  white  sugarm  an  iron  spoon 
over  a  charcoal  fire,  till  it  assumes  the  desired  tint,  and  then  pounng  it  into  a  little 

cold  water.  t    i      i 

Jied  is  given  by  cochineal  alone,  or  with  a  little  alum. 

Violet  is  given  by  good  litmus  (turnsole).  .  ^,         .       ..      -i.  i       -xv 

Blue  and  orecn.— Sulphate  of  indigo  gives  the  fii-st.  After  saturating  it  nearly  with 
chalk,  alcohol  being  digested  upon  it,  becomes  blue.  This  tincture  mixed  with  that 
of  earth  amus  forms  a  good  green. 

LIQUIDAMBER,  is  obtained  from  the  liquidamhar  styractjlua,  a  tree  which  grow§ 
in  Mexico,  Louisiana  and  Virginia.  Some  specimens  are  thin,  like  oil,  and  others  are 
thickish,  like  turpentine.  It  is  transparent,  amber  colored,  has  an  agreeable  and  power- 
ful smell,  and  an  aromatic  taste,  which  feels  pungent  in  the  throat.  Boiling  alcohol 
dissolves  it  almost  entirely.  It  contains  a  good  deal  of  benzoic  acid,  some  of  which 
effloresces  whenever  the  liquidamber  hardens  with  keeping.  .     . ,      ,  ,     , 

LITHARGE  (Eng.  and  Fr. ;  Glatte,  Germ.) ;  is  the  fused  yellow  protoxide  of  lead, 
which  on  cooling  passes  into  a  mass  consisting  of  small  six-sided  plates,  of  a  reddish 
yellow  color,  and  semi-transparent  It  generally  contains  more  or  less  red  lead,  whence 
the  variations  of  its  color;  and  carbonic  acid,  especially  when  it  has  been  exposed  to 
the  air  for  some  time.     See  Lead  and  Silver,  for  its  mode  of  preparation. 

LITHIA,  is  a  simple  earthy  or  alkaline  substance,  discovered  not  many  years  ago  in 
the  minerals  called  petalite  and  tiphane.  It  is  white,  very  caustic,  reddens  litmus,  and 
red  cabbage,  and  saturates  acids  with  great  facility.  When  exposed  to  the  air  it 
attracts  humidity  and  carbonic  acid.  It  is  more  soluble  in  water  than  baryta ;  and  has 
such  a  strong  affinity  for  it  as  to  be  obtained  only  in  the  state  of  a  hydrate.  It  forms 
neutral  salts  with  all  the  acids.     It  is  most  remarkable  for  its  power  of  acting  upon  or 

corroding  platinum.  •  i.      r  ,«/^    * 

LITHIUM,  is  the  metallic  basis  of  lithia ;  the  latter  substance  consists  of  100  of 

metal,  and  123  of  oxygen.  .  i.      i        v 

LITHOGRAPHIC  PRESS.  The  lithographic  press  m  common  use  has  long  been 
regarded  as  a  very  inadequate  machine.  The  amount  of  manual  power  required  to 
work  it,  and  the  slow  speed  at  which,  under  the  most  favorable  circumstances,  copies 
can  be  produced,  disables  lithography  in  its  competition  with  letter-press.  A  career 
of  brilliant  success  has  attended  the  efforts  of  scientific  men  towards  speed  and  per- 
fection in  this  latter  branch  of  the  art ;  and  the  present  printing  machines  surpass  the 
hand-press  somewhat  in  the  same  ratio,  as  does  our  express  speed  the  jog  trot  of  our 
forefathers.     The  engravings  annexed  will  serve  to  illustrate  Messrs.  Napier  A  Sons 


874 


improvements  upon  the  lithographic  pre.«s.  The  machine  i.s  arranged  to  be  driven  by 
steam  m»wer;  has  belts,  " crc.ssed  "  and  "open,"  supposed  to  be  in  connection  with  the 
engine,  and  to  run  upon  the  pulleys  a,  u,  c.     The  crank  pulley,  b,  is  fixed  on  the  screw 


LITHOGRAPHY. 


79 


epindle  d,  and  the  other  two  work  loose,  or  "  dead,"  on  the  same  spindle ;  these  bands 
with  their  striking  forks,  a,  are  arranged  so  as  to  be  brought  alternately  upon  the 
fixed  pulley,  b,  and  thus  a  reversing  motion  is  given  to  the  screw.  The  nut  in  which 
the  screw  works  is  fixed  to  a  crosspiece  e,  which  braces  the  side  frames  f,  f,  together  at 
bottom,  while  the  bar  g,  performs  the  same  oflice  at  top  ;  the  scraper  box,  h,  is  sustained 
between  these  frames  at  bearings  i,  and  is  so  fitted  as  to  work  freely.  To  support  the 
frames  and  scraper  box  independent  of  the  screw,  and  maintain  them  in  position,  allow- 
ing freedom  of  action,  the  rollers  j,  j,  are  provided,  which  run  in  the  planed  recesses, 
K,  along  the  top  of  the  main  standards  l. 

The  machine  is  shown  with  its  tympan  down,  ready  for  starting  ;  this  is  effected  by 
pressing  lightly  upon  the  lever,  6,  which  raises  a  catch,  and  allows  the  weight  m,  to 
descend  in  the  direction  of  its  present  inclination,  and  act  upon  the  connections  with  the 
striking  forks,  so  as  to  bring  one  of  the  bands  upon  the  fast  pulley  b,  and  make  the 
scraper  and  its  frames  move  forward.  Tlie  return  is  caused  by  the  frame  f,  coming  in 
contact  with  a  stop  c,  which  yielding,  acts  upon  the  striking  forks  by  its  bar  cf,  upon 
which  it  may  be  adjusted  to  give  the  travel  required.  On  the  return  being  accomplished 
the  machine  stops  itself  by  a  striking  action  against  stop  e,  the  catch  6,  falling  in  to 
prevent  the  weight  descending  to  its  full  throw,  and  thus  retaining  the  two  bands  upon 
the  two  dead  pulleys,  a  and  c,  while  the  machine  is  prepared  for  another  impression. 

The  action  of  the  scraper  is  peculiar  and  novel ;  it  is  balanced,  so  that  its  tendency  is 
to  remain  slightly  raised,  but  in  its  forward  movement,  and  at  the  point  desired,  it  is 
made  to  descend  by  a  stop  fixed  upon  the  top  of  the  main  standard,  l,  into  a  position 
vertical  or  nearly  so,  in  which  position  it  is  retained  by  its  own  onward  progress  against 
strong  abutments  projecting  from  the  frames,  f  ;  on  the  return  it  resumes  its  raised  posi- 
tion and  passes  back  without  impediment  The  scraper  may  be  adjusted  to  give  the 
pressure  desired,  or  the  table  on  which  the  stone  is  placed  regulated  by  screws. 

The  advantages  embodied  in  this  machine  will  be  at  once  recognized  by  those  in- 
terested. The  pulling  down  of  the  sci-aper,  and  the  labor  and  inconvenience  attendant 
upon  that  operation,  are  entirely  superseded  by  the  simple  and  effectual  valve-like 
movement  just  explained,  which  forms  the  groundwork  of  this  combination,  although 
it  will  alike  apply  to  the  press-work  by  hand,  and  is  the  most  striking  novelty  in  Uie 
machine. 

LITHOGRAPHY.  Though  this  subject  belongs  rather  to  the  arts  of  taste  and  design 
than  to  productive  manufactures,  its  chemical  principles  fall  within  the  province  of  this 
Dictionary. 

The  term  lithography^  derived  from  \i6oi  a  stone,  and  ypa<t>v,  writing,  and  designates 
the  art  of  throwing  off  impressions  upon  paper,  of  figures  and  writing  previously  traced 
upon  stone.     The  processes  of  this  art  are  founded : — 

1.  Upon  the  adhesion  to  a  smoothly-polished  limestone,  of  an  encaustic  fat  which 
forms  the  lines  or  traces. 

2.  Upon  the  power  ac<juired  by  the  parts  penetrated  by  this  encaustic,  of  attracting 
to  themselves,  and  becoming  covered  with  a  printer's  ink,  having  linseed  oil  fot-  its  basis. 

^11    u^°  *^^  interposition  of  a  film  of  water,  which  prevents  the  adhesion  of  the  ink 


paper  the 

.-  .  greasy  tracings  of  the  encaustic. 

I  he  lithographic  stones  of  the  best  quality  are  still  procured  from  the  quarry  of 
Solenhofen  a  village  at  no  great  distance  from  Munich,  where  this  mode  of  printing 
had  ita  birth.  They  resemble  in  their  aspect  the  yellowish  white  lias  of  Bath,  but  their 
geological  place  is  much  higher  than  the  lias.     Abundant  quarries  of  these  fine-grained 


!|l 


i| 


■  1 
H.     -  i 


80 


LITHOGRAPHY. 


limestones  occur  in  the  county  of  Pappenheim,  along  the  banks  of  the  Danube,  pre- 
senting slabs  of  every  required  degree  of  thickness,  parted  by  regular  seams,  and  ready 
for  removal  with  very  little  violence.  The  good  quality  of  a  lithographic  stone  is  gen- 
erally denoted  by  the  following  characters :  its  hue  is  of  a  yellowish  grey,  and  uniform 
throughout;  it  is  free  from  veins,  fibres,  and  spots ;  a  steel  point  makes  an  impression 
on  it  with  difficulty ;  and  the  splinters  broken  oflF  from  it  by  the  hammer  display  a  con- 
ohoidal  fracture. 

The  Munich  stones  are  retailed  on  the  spot  in  slabs  or  layers  of  equal  thickness; 
they  are  quarried  with  the  aid  of  a  saw,  so  as  to  sacrifice  as  little  as  possible  of  the  ir- 
regular edges  of  the  rectangular  tables  or  plates.  One  of  the  broad  faces  is  then  dressed, 
and  coarsely  smoothed.  The  thickness  of  these  stones  is  nearly  proportional  to  their 
other  dimensions ;  and  varies  from  1|  inches  to  3  inches. 

In  each  lithographic  establishment,  the  stones  receive  their  fininishing,  dressing  and 
polishing ;  which  are  performed  like  the  grinding  and  polishing  of  mirror  plate.  The 
word  is  done  by  hand,  by  rubbing  circularly  a  moveable  slab  over  another  cemented 
in  a  horizontal  position,  with  fine  sifted  sand  and  water  interposed  between  the  two. 
The  style  of  work  that  the  stone  is  intended  to  produce  determines  the  kind  of  polish 
that  it  should  get  For  crayon  drawing  the  stone  should  be  merely  grained  more  or 
lessen*  according  to  the  fancy  of  the  draughtsman.  The  higher  the  finish  of  the  sur- 
face, the  softer  are  the  drawings ;  but  the  printing  process  becomes  sooner  paitr/,  and  a 
smaller  number  of  impressions  can  be  taken.  Works  in  ink  require  the  stone  to  be 
more  softened  down,  and  finally  polished  with  pumice  and  a  little  water.  The  stones 
thus  prepared  are  packed  for  use  with  white  paper  interposed  between  their  faces. 

Lithographic  crayons. — Fine  lithographic  prints  cannot  be  obtained  unles  the  crayons 
possess  every  requisite  quality.  The  ingredients  composing  them  ought  to  be  of  such 
a  nature  as  to  adhere  strongly  to  the  stone,  both  after  the  drawing  Jias  undergone  the 
preparation  of  the  acid,  and  during  the  press-work.  They  should  be  hard  enough  to 
admit  of  a  fine  point,  and  trace  delicate  hues  without  risk  of  breaking.  The  following 
composition  has  been  successfully  employed  for  crayons  by  MM.  Bernard  and  Delarue, 
ftt  Paris. 

Pure  wax,  (first  quality)       ---..-    4 
Dry  white  tallow  soap  ---.--    2 

White  tallow 2 

Gum  lac -..-2 

Lamp-black,  enough  to  give  a  dark  tint        -        -        -     1 
Occasionally  copal  varnish 1 

The  wax  is  to  be  melted  over  a  gentle  fire,  and  the  lac  broken  into  bits  is  then  to  be 
added  by  degrees,  stirring  all  the  while  with  a  spatula ;  the  soap  is  next  introduced  in 
fine  shavings ;  and  when  the  mixture  of  these  substances  is  very  intimately  accomplished, 
the  copal-vanish,  incorporated  with  the  lamp-black,  is  poured  in.  The  heat  and 
agitation  are  continued  till  the  paste  has  acquired  a  suitable  consistence ;  which  may 
be  recognized  by  taking  out  a  little  of  it,  letting  it  cool  on  a  plate,  and  trying  its 
quality  with  a  penknife.  This  composition,  on  being  cut,  should  afford  brittle  slices. 
The  boiling  may  be  quickened  by  setting  the  rising  vapors  on  fire,  which  increases  the 
temperature,  and  renders  the  exhalations  less  offensive.  "When  ready,  it  is  to  be  poured 
into  a  brass  mould,  made  of  two  semi-cylinders  joined  together  by  clasps  or  rings, 
forming  between  them  a  cylindric  tube  of  the  crayon  size.  The  mould  should  be  pre- 
viously sraeathed  with  a  greasy  cloth. 

M.  Lasteyrie  prescribes  a  more  simple  composition,  said  to  be  equally  fit  for  the 
lithographer's  use : — 

Dried  white  tallow  soap      -        -        -        •         -    6  parts. 

White  wax -        -    6    — 

Lamp-black  -         -         -         -         -         -         -1     — 

Tlie  soap  and  tallow  are  to  be  put  into  a  small  goblet  and  covered  up.  When  the 
whole  is  thoroughly  fused  by  heat,  and  no  clots  remain,  the  black  is  gradually  sprinkled 
in  with  careful  stirring. 

Lithographic  ink  is  prepared  nearly  on  the  same  principle:— 


Wax 

Tallow 

Hard  tallow  soap 

Shell-lac     - 

Mastic  in  tears  - 

Venice  turpentine 

Lamp-black 


16  parts. 

6  — 

6  — 

12  — 

8  — 

1  — 

4  — 


LITHOGRAPHY.  gj 

f„3IlnfTnl'*' fi*""^  ^^""^  previ^ously  ground  together,  are  to  be  heated  with  care  in  the 
^i^L  f K  •  '  'V'^*'''-  *°i  t«",<>\«re  to  be  aided  after  they  are  taken  oflF  the  fire,  and 
Waok  isTo'hl  w.n1  f'^'^^'f'  ea?P  «h*^i«g«  «-« to  be  thrown  in.  Lastly  the^amp 
black  is  to  be  well  intermixed.     Whenever  the  union  is  accomplished  by  heat  Se 

tLlled  or  nver  water.  Jt  should  be  flowing  in  the  pen,  not  spreading  on  the  st^n  J:  ca  m-" 
ble  of  forming  delicate  traces,  and  very  black  to  show  its  delineations  The  most  es^in 
tial  quality  of  the  ink  is  to  sink  well  into  the  stone,  so  as  to  re-prXce  the  m^t  delica  e 
ou  hnes  of  the  drawing,  and  to  aflbrd  a  great  man^  impressions  It^u.t  TheVefore  b! 
able  to  resist  the  acid  with  which  the  stone  is  moistened  in  the  preparat  on  without  let! 
tmg  any  of  its  greasy  matter  escape.  cp*iiaiiun,  ^Minoui  lei- 

prefeVl^e  rolrfolwL""  """"^  '"'^  "  ^™'  '""'^  combinations,  he  gives  .he 


Tallow  soap,  dried  - 

Mastic,  in  tears 

White  soda  of  commerce 

Shellac 

Lamp-black     - 


30  parts 
30  — 
30  — 
150  — 
12  — 


« JJi  r^  *•    ^^'/"'  /''*''  ^^^  ^?^^^^  *"^  '"^It^  over  the  fire,  to  which  the  lac  being 
added  fuses  immediately ;  the  soda  is  then  introduced,  and  next  the  mastic,  stirrin- aU 

^tZt      r'  .K  '^v!"^-    ^  ^'^J"  ^'^. ''  ^PP"^^  ^"1  ^»  these  materials  be  melted  com- 
pletely,  when  the  whole  is  poured  out  into  the  mould. 

The  inks  now  prescribed  may  be  employed  equaUy  with  the  pen  and  the  hair  pencil 

for  writings,  black-lead  drawings,  aqua  tinta,  mixed  drawings,  those  which  represent  en! 

gravings  on  wood  (wood  cuts),  &c.     When  the  ink  is  to  bemused  it  is  to  be  rubbed  down 

with  water,  m  the  manner  of  China  ink,  till  the  shade  be  of  the  requisite  depth.      The 

TS   '^    ^.^A  ^1^' M*'".^^'  ^°>^  ^"^^^  ^^°  ^«  ^^  ^'^•^^M  «^  tl^e  saucer  in  which  the 

than  IS  to  be  used  at  the  time,  for  it  raiely  keeps  in  the  Hquid  state  for  24  hours  ;  and  it 
BQouId  be  covered  or  corked  up.  ' 

^utographic  paper.— Autogmphy,  or  the  operation  by  which  a  writing  or  a  drawing  is 
fransferred  ^om  paper  to  stone,  presents  not  merely  a  means  of  abridging  labor,  but  dso 
^at  of  reverting  the  writmgs  or  drawings  into  the  direction  in  which  they  we^e  traced, 
whilst.  If  executed  directly  upon  the  stone,  the  impression  given  by  it  is  inverted.     Henc? 

nZ'T^  J^^T  '^^'"^  "'?'  ^^  '""l^'^^^  ^"^'^  "-*^t  t°  ^^ft  to  obtain  direct  impressions! 
But  the  art  of  writmg  thus  is  tedious  and  difficult  to  acquire,  while,  by  means  of  the 
autographic  paper  and  the  transfer,  proofs  are  obtained  in  the  same  direction  with  the 
writing  and  drawing. 

.^tt/ograp/iic  nife.-It  must  be  fatter  and  sof\er  than  that  appUed  directly  to  the  stone, 
BO  that  though  dry  upon  the  paper,  it  may  still  preserve  sufficient  viscidity  to  stick  to  the 
stone  by  mere  pressure.  -. »«  vuc 

To  compose  this  ink,  we  take — 


White  soap       ... 
White  wax  of  the  best  quality 
Mutton  suet      ... 
Shellac  .... 

Mastic      .... 
Lamp-black    -        -        .        - 


100  parts 

100  — 

30  — 

60  — 

50  — 

30  or  35  — . 


These  materials  are  to  be  melted  as  above  described  for  the  Uthographic  ink. 
LUhographic  ink  and  paper.-The  foUowing  recipes  have  been  much  commended  :- 

Virgin  or  white  wax 8  parts 

White  soap      ......  2  

Shellac       ---....2  

Lamp-black "        3  table-spoonsfm. 

hoflftn''?ntr'^P^h7r  ^"i^^^P.^e  to  be  melted  together,  and  before  they  become  so 
hot  as  to  take  fire  the  lamp-black  is  to  be  well  stirred  in  with  a  spatula,  and  then  the 

SJf  .i'i^^^^"'^''''^  ^^  ^J""  ^°'  30  ^^^«"^«5  the  flame  being  extinguished,  the  lac  i^ 
to  be  added  by  degrees,  carefully  stirring  all  the  time ;  the  vessll  is  to^be  put  upo^  the 
k[nTH  Z""  °^^e[  to  complete  the  combination,  and  till  the  materials  are  either 

li  ?1P  fjr"  ^  r-  ♦  ^^^  the  flame  is  extinguished,  the  ink  must  be  suffered  to  cool  a 
utile,  and  then  put  into  the  moulds. 

Vol,  XL  « 


82 


LIXIVIATION. 


LUBRICATION. 


83 


•1      ! 

I 
I 


!l 


>■  ! 


i 

lull 

I 

t 

ii«i 


With  the  ink  crayons  thns  made,  lines  may  be  drawn  as  fine  as  with  the  point  of  the 
graver,  and  as  full  as  can  be  desired,  without  risk  of  its  spreading  in  the  carriage.  Its 
traces  will  remain  unchanged  on  paper  for  years  before  being  transferred. 

Some  may  think  it  strange  that  there  is  no  suet  in  the  above  composition,  but  it  has 
been  found  that  ink  containing  it  is  only  good  when  u?ed  soon  after  it  is  made,  and  when 
immediately  transfeired  to  the  stone,  while  traces  drawn  on  paper  with  the  suet  ink  be- 
eome  defective  after  4  or  5  days. 

Lithographic  paper. — Lay  on  the  paper,  3  successive  coats  of  sheep-feet  jelly, 

1  layer  of  white  starch, 
1  layer  of  gamboge. 

The  first  layer  is  applied  with  a  sponge  dipped  in  the  solution  of  the  hot  jelly,  very 
equally  over  the  whole  surface,  but  thin ;  and  if  the  leaf  be  stretched  upon  a  cord,  the 
gelatine  will  be  more  uniform.  The  next  two  coats  are  to  be  laid  on,  until  each  is  dry. 
The  layer  of  starch  is  then  to  be  applied  with  a  sponge,  and  it  will  also  be  very  thin  and 
equal.  The  coat  of  gamboge  is  lastly  to  be  applied  in  the  same  way.  When  the  paper 
is  dry,  it  must  be  smoothed  by  passing  it  through  the  lithographic  press ;  and  the  naore 
polished  it  is,  the  better  does  it  take  on  the  ink  in  fine  lines. 

Trantfer. — When  the  paper  is  moistened,  the  transfer  of  the  ink  from  the  gamboge  is 
perfect  and  infallible.  The  starch  separates  from  the  gelatine,  and  if,  after  taking  the 
paper  off  the  stone,  we  place  it  on  a  white  slab  of  stone,  and  pour  hot  water  over  it,  it 
will  resume  its  primitive  state. 

The  coat  of  gamboge  ought  to  be  laid  on  the  same  day  it  is  dissolved,  as  by  keeping  it 
becomes  of  an  oily  nature ;  in  this  state  it  does  not  obstruct  the  transfer,  but  it  gives  8 
gloss  to  the  paper  which  renders  the  drawing  or  tracing  more  difficult,  especially  to  per- 
sons little  habituated  to  lithogiaphy. 

The  stareh  paste  can  be  employed  only  when  cold,  the  day  after  it  is  made,  and  after 
having  the  skin  removed  from  its  surface. 

A  leaf  of  such  lithographic  paper  may  be  made  in  two  minutes. 

In  transferring  a  writing,  an  ink  drawing,  or  a  lithographic  crayon,  even  the  impression 
of  a  copper-plate,  to  the  stone,  it  is  necessary,  1.  that  the  impressions  be  made  upon  a  thio 
and  slender  body  like  common  paper ;  2.  that  they  may  be  detached  and  fixed  totally  on 
the  stone  by  means  of  pressure ;  but  as  the  ink  of  a  drawing  sinks  to  a  certain  depth  in 
paper,  and  adheres  pretty  strongly,  it  would  be  difficult  to  detach  all  its  parts,  were  there 
not  previously  put  between  the  paper  and  the  traces,  a  body  capable  of  being  separated 
from  the  paper,  and  of  losing  its  adhesion  to  it  by  means  of  the  water  with  which  it  is 
damped.  In  order  to  produce  this  effect,  the  paper  gets  a  certain  preparation,  which  con- 
sists in  coating  it  over  with  a  kind  of  paste  ready  to  receive  ev«7  delineation  withoiit 
suffering  it  to  penetrate  into  the  paper.  There  are  different  modes  of  communicating  this 
properly  to  paper.  Besides  the  above,  the  following  may  be  tried.  Take  an  unsized 
paper,  rather  strong,  and  cover  it  with  a  vami^  composed  of: — 

Starch  ...  -  -  120  parts 

Gum  arable  -  -  -         '  -  -  40    — 

Alum  -  -  -  •  •  20    — 

A  paste  of  moderate  consistence  must  be  made  with  the  starch  and  some  water,  with 
the  aid  of  heat,  into  which  the  gum  and  alum  are  to  be  thrown,  each  previously  dissolved 
in  .separate  vessels.  When  the  whole  is  well  mixed,  it  is  to  be  applied,  still  hot,  on  the 
leaves  of  paper,  with  a  flat  smooth  brush.  A  tint  of  yellow  color  may  be  given  to  the 
varnish,  with  a  decoction  of  the  berries  of  Avignon,  commonly  called  French  berries  by 
cm-  dyers.  The  paper  is  to  be  dried,  and  smoothed  by  passing  under  the  scraper  of  the 
lithographic  press. 

Steel  pens  are  employed  for  writing  and  drawing  with  ink  on  the  lithographic 
stones. 

LITMUS  (Tmrmsol,  Fr. ;  Lackmus,  Germ.)  is  prepared  in  Holland  from  the  species 
of  lichen  called  Lecanora  tartarea,  Roccella  tartareay  by  a  process  which  has  been  kept 
secret,  but  which  is  undoubtedly  analogous  to  that  for  making  archil  and  cudbear.  The 
ground  lichens  are  first  treated  with  urine  containing  a  little  potash,  and  allowed  to  fer- 
ment, whereby  they  produce  a  purple-red ;  the  colored  liquor,  treated  with  quicklime  and 
some  more  urine,  is  set  again  to  ferment  during  two  or  three  weeks,  then  it  is  mLxed  with 
chalk  or  gypsum  into  a  paste,  which  is  formed  into  small  cubical  pieces,  and  dried  in  the 
shade.  Litmus  has  a  violet-blue  color,  is  easy  to  pulverize,  is  partially  soluble  in  water 
and  dilute  alcohol,  leaving  a  residuum  consisting  of  carbonate  of  lime,  of  clay,  silica, 
gypsum,  and  oxyde  of  iron  combined  with  the  dye.  The  color  of  litmus  is  not  altered  by 
alkalis,  but  is  reddened  by  acids ;  and  is  therefore  used  in  chemistry  as  a  delicate  test  of 
acidity,  either  in  the  state  of  solution  or  of  unsized  paper  stained  with  it.  It  is  employed 
to  dye  marble  blue. 

LIXIVIATION  (Lessivage,  Fr.  j  Juslagen,  Germ.)  signifies  the  abstraction  by  wate. 


of  the  soluble  alkaline  or  saline  matters  present  in  any  earthy  admixture ;  as  from 
that  of  qu.ckhme  and  potashes  to  make  potash  lye,  rfom  thit  of  effloresced  alum 
schist  to  make  aluminous  liquors,  Ac 

rim'll^f^-^^  MAGNETIC  IRON-STONE  (i^.r  oxydule,  Fr. ;  Magneteisenstein, 
fombinathm  ^'''^  ««°««tmg  of  the  protoxide  and  peroxide  of  iron  in  a  state  of 

on^?^  ^^'''''  /tmonm*^,  Fr  ;  Lekm,  Germ.);  a  native  clay  mixed  with  quartz  sand 
and  iron  ochre,  and  occasionally  with  some  carbonate  of  lime 

kPv^S^.^j?f  ^^  ^^^^^-  *  J^,^  P«<^«lif  "ty  of  this  lock  consisis  in  an  extension  of  the 
key  aftei  it  is  inserted  m  the  lock,  and  a  secret  connection  between  the  interior  of  the 
key  and  two  of  the  players.  The  two  inclined  planes  on  the  under  side  of  tTe  wards 
open  or  shut  the  extension  of  the  key  as  it  passes  over  them  :  the  part  of  the  key  thus 
extended  operates  on  two  players  placed  beyond  the  reach  of  picklocks,  while  at  th« 
same  time  the  mam  part  of  the  key  works  other  two  players,  which  are  again  operated 
on  by  the  secret  apparatus  in  the  interior  of  the  key.  This  secret  ap?irtus^cln  be 
removed  at  pleasure,  and  the  proper  key  then  becomes  unfit  to  work  the  lock  and 
skeleton  kep  however  well  fitted  to  pass  the  wards,  will  not  operate  on  the  players 

LODE,  IS  the  name  given  by  the  Cornish  miners  to  a  vein,  wLther  it  be  filled  with 
metallic  or  earthy  matter.  ^ "'" 

//if  ^^^^^^^^''**  t  ^«^^^^^^'  ^o''  *^^«'  Fr- ;  ^l^^hoh,  Germ. ;  is  the  wood  of  the 
mtmatoxylon  Campecnanum  a  native  tree  of  central  America,  grown  in  Jamaica  since 

Ilk  \^«  *^f  V°^'^*^^'f^  '"*.^  ^"S^^"^  ^"  ^^^  ^^'^»  of  Elizlbeth.  but  as  it  afforded 
to  the  unskilful  dyers  of  her  time  a  fugitive  color,"it  was  not  only  prohib  ted  from 
being  used  under  severe  penalties,  but  was  ordered  to  be  burned  wherever  found  hZ 

tl  ^""""^f  T  ^^' '^^^  ny  ^^^"'*  '•''^"-  "^''^  ^^"^^  P^^J"^'««  existed,  and  the  Tme  tw 
was  enacted  against  indi^o.  At  length,  after  a  c/ntury  of  absurd  prohibition  thes^ 
two  most  valuable  tinctorfal  matters,  by  which  all  our  hats,  and  tlfe  greater  part  of 
our  woollen  cloths  are  dyed,  were  allowed  to  be  used  greater  part  of 

^f  ^'^,'^r'^'  "^'^u  ^^^""^  '^^""^  *"^  "^'^^  ^'^**e  «^  ^^^  ^^ite  alburnum,  is  preferred  Log- 
wood is  denser  than  water,  very  hard,  of  a  fine  compact  grain,  and  almost  inditmct 

For  its  chemical  composition,  see  Hemativ 

When  chipped  logwood  is  for  some  time  exposed  to  the  air,  it  loses  a  portion  of  its 
dyeing  power.  Its  decoction  absorbs  the  oxvgenof  the  atmosphere  and  then  aem,i,pt 
the  property  of  precipitating  with  gelatine,  Vhich  it  had  not  before.  TTie  dry  extract 
of  logwood,  made  from  an  old  decoction,  affords  only  a  fugitive  color.  ^ 

i>r:LT^fB^^z:ii  '^""^'  "^  ""^^^^  ^^'^^  ^«^-^  ^-^  ^-- 1-™; 

q 'T^'r^i"'^'""*^  olt^^''''^  ^^"^  .^°  }^^^'  ^^'^^^  *«"«;  i"  1851,  21,240  tons:  of  which 
'  T  AA^?^*,'^^  ^'^^^  ^""^  respectively  were  re-exported. 
monv      /''•''  '^**T'/^•^   ^<^f>^rstuhl.  Germ.);  is  the  ancient  and  well-known 
machine  for  weaving  cloth  by  the  decussation  of  a  series  of  parallel  threads  which  Z 
lengthwise  called  the  warp  or  chain,  with  other  threads  thrown  transversely  wTth  ^e 

T  tt^'t,?"^*^  *^'^  ^*^^  **'•  ^^^^^^     See  Jacquard  Loom  Weaving  ^ 

ioint^^^i  >f^'-^^-  7^'^  ?"^^"l^  ^"-"J?^"  ^°^  efficacious  plan  of  lubricating  the 
iXd  to  1  w'?f  •'  "^.^^^"^^'•^^  ^y  '^P^^^y  attraction,  has  been  kindly  comm4i- 
cat^d  to  me,  by  its  ingenious  inventor,  Edward  Woolsey  Esq  •—  "i»nuHi 

fi,    if'i    •  '■eP'i^^ents  a  tin  cup,  which  has  a  small  tin  tube  a,  which  Da<«se8  through 

tnb^'  J      ^^P;^'«ry/tt,ractK)n  causes  the  oil  to  ascend  and  pass  over  the  orifice  of  the 

lenVo  The%hrJ:d'"  *"',  '^^^^^  slower  or  q^iicker,  acc::di;g  to  t  : 

lengin  ot  the  thread  or  its  thickness,  until  every  particle  of  oil  is  drawn  over  bv  th  ! 
capillary  svphon.  The  tube  is  intended  to  be  put  into  the  bearings  of  shaft'  x/  ^'d 
18  made  of  any  size  that  may  be  wished.    If  oil,  or  other  liquid  LdeSed 

t^^Z  ^eflin^"^  '''  ^^^-  -'•^-^'  ^^^^  -P  -"  havTl'^and?:!':  it  t  It 


""^  S^  ^"^^  preventing  the  oil  from  passing. 

and  mowlteVrinL'^IhlTfh^''  '''•  ^  ^^Mfff-.^l^  are  used  upon  beams  of  engines 
I  thi^t  "e  act^oTff'tt  !  '"'^^  isapt  to  be  tightened  by  the  motion  ;  and  alfo  as 
dowr?  Jffi«:  Vi  •/  ^'""T  '*  ""certain,  from  the  workmen  ne^lectini  to  screw  it 
down  sufficiently,  it  answers  best  to  take  out  the  capillary  thread  when  thi  lubrication 


I 

ni  * 


■I ' 


if 


84 


LTTPULINE. 


is  not  required  '  and  to  effect  this  easilj,  I  have  a  tin  top  to  the  cup,  with  a  round 
pipe  soldered  to  it :  this  pipe  has  a  slit  in  it,  like  a  pencil  case,  and  allows  a  bolt  b, 
to  slide  easily  in  it.  In  Jig.  881,  the  bolt  is  down ;  in  ^g.  882,  the  bolt,  which  is  a 
piece  of  brass  wire,  is  drawn  up,  and  there  is  no  capillary  action  between  the  thread 
and  the  oil.  In  Jig.  882,  it  will  be  observed,  that  the  bolt  is  kept  in  its  place  by  its  head 
c,  resting  in  a  lateral  slit  in  the  pipe,  and  it  cannot  be  drawn  out  on  account  of  the 
pin  E.  One  end  of  the  thread  is  fastened  to  the  eye  hole  at  the  bottom  of  the  bolt, 
and  the  other  end  is  tied  to  a  small  wire  which  crosses  the  lower  orifice  of  the  tube  at 
D,  and  which  is  shown  in  ^l&njig.  883. 

By  this  simple  contrivance  the  capillary  action  can  be  stopped  or  renewed  in  a 
second,  without  removing  the  top  of  the  lubricator. 

The  saving  by  this  plan,  instead  of  pouring  oil  into  the  bearings,  is  2  gallons  out  of 
8,  while  the  bearings  are  better  oiled. 

819  877  878  876 


K 


c, 

882 

] 

E^ 

"  I  send  you  the  drawings  of  the  lubricators,  with  a  detailed  explanation.  I  have 
omitted  to  state,  that  the  saving  in  labor  is  considerable  where  there  are  many  joints 
to  keep  oiled  three  or  four  times  a  day ;  and  that  the  workman  does  not  with  this 
apparatus,  run  the  risk  of  being  caught  by  the  machinery.  Perhaps  your  friends  may 
be  at  a  loss  how  to  tie  on  the  cotton  or  worsted  thread.  I  pass  a  long  thread  through 
the  eye-hole  e  of  the  bolt,  and  then  draw  the  two  ends  through  the  tube  by  a  fine  wire 
with  a  hook  to  it,  one  end  on  one  side  of  the  cross  wire  d,  and  the  other  end  on  the  othei 
side.  I  then  put  the  cover  on,  and  the  bolt  in  the  position  sho-vn  in  Jig.  651 ;  when  by 
drawing  the  two  ends  of  the  thread,  and  tying  them  across  the  wire  d,  you  have  the  exact 
length  required.  When  you  wish  to  see  the  quantity  of  oil  remaining  in  the  lubricator, 
the  bolt  must  be  dropped  as  in  Jig.  650,  and  you  can  then  lift  the  cover  a  little  way  oflT, 
without  breaking  the  thread,  and  replenish  with  oil.  The  cost  of  Jig.  650,  in  tin  plate,  is 
9i.    The  figures  in  the  wood  cuts  are  one  third  of  the  full  size. 

«  Believe  me  to  be  yours  sincerely, 

"  E.  J.   W00LSEY.»» 

LUPININE,  is  a  substance  of  a  gummy  appearance,  so  named  by  M.  Cussola,  because 
it  was  obtained  from  Lupines. 

LUPULINE,  from  Humulua  Lupulus ;  is  the  peculiar  bitter  aromatic  principle  of  the 
hop.    See  Beeh. 


MACERATION. 

LUTE  (from  lutum,  clay;  Lut,  Fr. ;  Kitte,  Beschldge,  Germ.),  is  a  pasty  or  loamy 
matter  employed  to  close  the  joints  of  chemical  apparatus,  or  to  coat  their  surfacei 
and  protect  them  from  the  direct  action  of  flame.  Lutes  differ  according  to  the  nature 
of  the  vapors  which  they  are  destined  to  confine,  and  the  degree  of  heat  which  thev 
are  to  be  exposed  to.  ^ 

1.  Lute  of  linseed  meal,  made  into  a  soft  plastic  dough  with  water,  and  immediately 
applied  pretty  thick  to  junctions  of  glass  or  stone  ware,  makes  them  perfectly  tight 
hardens  speedily,  resists  acid  and  ammoniacal  vapors,  as  also  a  moderate  degree  of 
heat  It  becomes  stronger  when  the  meal  is  kneaded  with  milk,  lime-water,  or  solu- 
tion of  glue. 

2.  Lute  of  thick  gum-water,  kneaded  with  clay,  and  iron  filings,  serves  well  for  per- 
manent junctions,  as  it  becomes  extremely  solid. 

3.  By  softening  in  water  a  piece  of  thick  brown  paper,  kneading  it  first  with  rye- 
flour  paste,  and  then  with  some  potter's  clay,  till  it  acquire  the  proper  consistenc^  a 
lute  18  formed  which  does  not  readily  crack  or  scale  off. 

4.  Lute,  consisting  of  a  strong  solution  of  glue  kneaded  into  a  dough  with  new 
slaked  lime,  is  a  powerful  cement,  and  with  the  addition  of  white  of  egg  forms  the  liUe 
d'ane;—&  composition  adapted  to  mend  broken  vessels  of  porcelain  and  stone- ware. 

6.  Skim-milk  cheese,  boiled  for  some  time  in  water,  and  then  triturated  into  paste 
with  fresh-slaked  lime,  forms  also  a  good  lute. 

6.  Calcined  gypsum,  diffused  through  milk,  solution  of  glue  or  starch,  is  a  valuable 
lute  in  many  cases. 

7.  A  lute  made  with  linseed,  melted  caoutchouc,  and  pipe-clay,  incorporated  into  a 
smooth  dough,  may  be  kept  long  soft,  when  covered  in  a  cellar,  and  serves  admi- 
rably to  confine  acid  vapors.  As  it  does  not  harden,  it  may  therefore  be  applied  and 
taken  off  as  often  as  we  please. 

8.  Caoutchouc  itself  after  being  melted  in  a  spoon,  may  be  advantageously  used  for 
securing  joints  against  chlorine  and  acid  vapors,  in  emergencies  when  nothing  else 
would  be  effectual     It  bears  the  heat  at  which  sulphuric  acid  boils. 

9.  The  best  lute  for  joining  crucibles  inverted  in  each  other,  is  a  dough  made  with 
a  mixture  of  fresh  fire-clay  and  ground  fire-bricks,  worked  with  water.  That  cement,  if 
made  with  solution  of  borax,  answers  still  better,  upon  some  occasions,  as  it  becomes  a 
compact  vitreous  mass  in  the  fire.     See  Cements. 

Lute /or  conjining  acids.  1  part  of  caoutchouc  dissolved  in  two  parts  of  hot  linseed- 
oil,  and  worked  up  with  pipe  clay  (3  parts)  into  a  plastic  mass.  Linseed  meal  and 
water  forms  the  best  lute  for  fluo-silicic  acid. 

LUTEOLINE,  is  a  yellow  coloring  matter  discovered  by  Chevreul  in  weld.     When 
sublimed,  it  crystallizes  in  needles, 

LYCOPODIUM  CLAVATUM.    The  seeds  of  the  lycopodiura  ripen  in  September 
They  are  employed,  on  account  of  their  great  combustibility,  in  theatres,  to  imitate 
the  sudden  flash  of  lightning,  by  throwing  a  quantity  of  them  from  a  powder  puff  or 
bellows,  across  the  flame  of  a  candle.  ' 

LYDIAN  STONE,  is  flint-slate. 


M. 

MACARONI,  is  a  dough  of  fine  wheat  flour,  made  into  a  tubular  or  pipe  form  of 
the  thickness  of  goose-quills,  which  was  first  prepared  in  Italy,  and  introduced  into 
commerce  under  the  name  of  Italian  or  Genoese  paste.  The  wheat  for  this  purpose 
must  be  ground  into  a  coarse  flour,  called  gruau  or  semoule,  by  the  French,  by  means  of 
a  pair  of  light  mill-stones,  placed  at  a  somewhat  greater  distance  than  usual.  This 
temoule  is  the  substance  employed  for  making  the  dough.  For  the  mode  of  manufac- 
turing it  into  pipes,  see  Vermicelli. 

mace;  is  a  somewhat  thick,  tough,  unctuous  membrane,  reticulated  or  chapt,  of  a 
yellowish-brown  or  orange  color.  It  forms  the  envelope  of  the  shell  of  the  fruit  of  the 
mi/rishca  mosckata,  which  contains  the  nutmeg.  It  is  dried  in  the  sun,  after  being 
dipped  in  brine ;  sometimes  it  is  sprinkled  over  with  a  little  brine,  before  packing 
to  prevent  the  risk  of  moulding.  Mace  has  a  more  agreeable  flavor  than  nutmeg  •  with 
a  warm  and  pungent  taste.  It  contains  two  kinds  of  oU ;  the  one  of  which  is  unctuous, 
bland,  and  of  the  consistence  of  butter ;  the  other  is  volatile,  aromatic,  and  thinner. 
1  he  membrane  is  used  as  a  condiment  in  cookery,  and  the  aromatic  oil  in  medicine. 

The  quantity  imported  in  1850  was  77,337  lbs.;  in  1851,  74,863  lbs. ;  entered  for 
consumption,  1850,  21,997  lbs.;  1851,  21,695 lbs.;  duty  received,  respectively,  2.887i 
and  2,847 «.  -'       r  jt    * 

MACERATION  (Eng.    and  Fr.    Einwichen,    Germ.),  is    a   preparatory   steep  to 

/ 


86 


MACHINES  (SELF-ACTING). 


MADDER. 


87 


»iii 


which  certain  vegetable  and  animal  substances  are  submitted,  with  the  view  of  dis- 
tending their  fibres  or  iwres,  and  causing  thorn  to  he  penetrated  by  such  menstruiias 
are  best  adapted  to  extract  their  soluble  parts.     Water,  alone,  or  mixed  with  acids, 
alkalis,  or  salts;  alcohol  and  ether,  are  the  liquids  usually  employed  for  that  purpose. 
MACHINES  {Self-acting.)     The  application  of  aclf -acting  Machines  to  the  Construc- 
tion of  Machinery.     It  is  nearly  half  a  century  since  I  first  became  acquainted  with 
the  engineering  profession,  and:  at  that  time  the  greater  part  of  our  mechanical  opera- 
tions were  done  by  hand.     On  my  first  entrance  into  Manchester  there  were  no  self- 
acting  tools,  and  the  whole  stock  of  an  engineering  or  machine  establishment  might  be 
summed  up  in  a  few  ill-constructed  lathes,  a  few  drills,  and  boring  machines  of  rude 
construction.     Now  compare  any  of  the  present  works  with  what  they  were  in  those 
days,  and  you  will  find  a  revolution  of  so  extraordinary  a  character,  as  to  appear  to  those 
unacquainted  with  the  subject  as  scarcely  entitled  to  credit.   The  change  thus  effected, 
and  the  improvements  introduced  into  our  constructive  machinery,  are  of  the  hi'^'hest 
importance ;  and  it  gives  me  pleasure  to  add  that  they  chiefly  belong  to  Manchester, 
are  of  Manchester  growth,  and  from  Manchester  they  have  had  their  origin.     It  may 
be  interesting  to  know  something  of  the  art  of  tool-making,  and  of  the  discoveries  anil 
progress  of  machines  which  have  contributed  so  largely  to  multiply  the  manufactures 
as  well  as  the  construction  of  other  machines  employed  in  practical  mechanics.     In 
Manchester  the  art  of  calico-printing  was  in  its  infancy  forty  yeare  ago;  the  flat  press, 
and  one  or  at  the  most  two  colored  machines,  were  all  that  were  then  in  use;  the 
number  of  those  machines  is  now  greatly  multiplied,  and  some  of  them  are  capable  of 
printing  eight  colors  at  once;  and  the  arts  of  bleaching,  dyeing,  and  finishing,  have 
undergone  equal  extension  and  improvement.     In  the  manufacture  of  steam-engines 
there  were  only  three  or  four  establishments  that  could  make  them,  and  those  were 
Jiolton  and  Watt,  of  Soho  ;  Fenton,  Murray  and  Wood,  of  Leeds,  and  Messrs.  Sherratts 
ot  this  town.     The  engines  of  that  day  ranged  from  3  to  60  or  at  the  most  70  horses' 
power;  now  they  are  made  as  high  as  500,  or  in  pairs  from  1,000  to  1,200  horse.    An 
order  for  a  single  engine  at  that  time  was  considered  a  great  work,  and  frequently 
took  ten  or  twelve  months  to  execute  ;  now  they  are  made  by  dozens,  and  that  with  a 
degree  of  despatch  as  to  render  it  no  unccftnmon  occurrence  to  see  five  or  six  engines  of 
considerable  power  leave  a  single  establishment  in  a  month.     In  machine  making  the 
same  powers  of  production  are  apparent.    In  this  department  we  find  the  same  aeti  vitj^ 
the  same  certainty  of  action,  and  greatly  increased  production  in  the  manufacture  of  the 
smaller  machines,  than  can  possibly  be  attained  in  the  larger  and  heavier  description  of 
work.  The  self-acting,  turning,  planing,  groovinsr,  and  slotting  machines  have  afforded 
80  much  accuracy  and  facility  for  construction,  as  to  enable  the  mechanical  practitioner 
to  turn,  bor^and  shape  with  a  degree  of  certainty  almost  amounting  to  mathematical 
precision.     The  mechanical  operations  of  the  present  dav  could  not  have  been  accom- 
plished at  any  cost  thirty  years  ago,  and  what  was  considered  impossible  at  that  time 
IS  now  performed  with  a  degree  of  intelligence  and  exactitude  that  never  fail  to  accom- 
plish the  end  m  view,  and  reduce  the  most  obdurate  mass  to  the  required  consistency, 
m  all  those  forms  so  strikingly  exemplified  in  the  workshops  of  engineers  and  machinists, 
lo  the  intelligent  and  observant  stranger  who  visits  these  establishments, the  first  thing 
that  strikes  his  attention  is,  the  mechanism  of  the  self-acting  tools,  the  ease  with  which 
they  cut  the  hardest  iron  and  steel,  and  the  mathematical  accuracy  with  which  all  the 
parts  of  a  machine  are  brought  into  shape.     When  these  implements  are  carefully 
examined  it  ceases  to  be  a  wonder  that  our  steam-engines  and  machines  are  so  beau- 
tifully and  correctly  executed.     We  perceive  the  most  curious  and  ingenious  contri- 
vances adapted  to  every  purpose,  and  machinery  which  only  requires  the  attendance  of 
a  boy  to  supply  the  material  and  apply  the  power,  which  is  always  at  hand.    In  conclu- 
sion,  1  would  observe  that  it  is  an  honor  to  this  country,  that  we  stand  at  the  head  of 
the  engineering  and  mechanical  profession.     It  is  an  art— I  would  call  it  a  science— 
which  has  occupied  the  attention  of  the  greatest  men  from  the  days  of  Galileo  and  New- 
ton down  to  those  of  Watt  and  Sraeaton,  and  it  now  receives  attentive  consideration 
from  some  of  the  ablest  and  most  distinguished  men  of  the  present  time.  And  of  the^e 
™^y  *WM^?^®  Poncelet,  Morni,  Humboldt,  Brewster,  Babbage,  Dr.  Robinson  (of  Ar- 
magh),  Willia  and  many  others,  to  show  the  interest  that  is  taken  by  these  great  men 
m  the  advancement  of  mechanical  science.     A  great  deal  has  been  done,  but  a  great 
deal  more  may  yet  be  accomplished,  if  by  suitable  instruction  we  carefully  store  the 
mmds  of  our  foremen  and  operatives  with  useful  knowledge,  and  afford  them  those 
opportunities  essential  to  its  acquisition.    We  must  try  to  unite  theory  with  practice, 
and  bring  the  philosopher  into  close  contract  with  the  practical  mechanic.     We  must 
try  to  remove  prejudices,  and  to  encourage  a  sounder  system  of  management  in  the 
manufactures,  design,  and  projects  of  the  useful  arts.     When  this  is  accomplished,  we 
shall  no  longer  witness  abortions  in  construction,  but  a  carefully  well-digested  system 
of  operations,  founded  on  the  unerring  laws  of  physical  truth.— W.  Fairhaim  Esq 


MACHINERY  for  cask-making.  A  novel  method  of  constructing  casks,  barrels,  and 
&I1  vessels  connected  with  cooperage,  may  be  seen  in  operation  at  the  Patent  Cooper- 
age Works  in  Wenlock  Road,  City  Road.  By  the  emploj'^ment  of  the  steam-engine, 
the  circular  saw,  and  a  recently-invented  jointing  and  backing  machine,  a  cask  of  the 
largest  dimensions  can  be  completely  formed  and  made  ready  for  use  in  the  short  space 
of  fave  minutes,  from  the  raw  material,  viz.,  a  piece  of  oak.  The  staves  of  the  cask  are 
first  cut  with  straight  sides,  the  circular  saw  being  placed  at  a  right  angle  with  the 
oak  plank.  The  stave  is  then  placed  horizontally,  and  bent  into  a  curve  by  a  power- 
ful machine,  and  brought  into  contact  with  a  circular  saw  on  each  side  of  it,  placed  at 
an  angle.  This  process  gives  the  proper  shape  to  the  stave,  the  sides  being  gradually 
tapered  at  the  ends,  and  made  to  bulge  in  the  middle.  The  jointing  and  backing  ma- 
chine, the  new  invention,  is  also  used  for  this  purpose,  and  is  more  rapid  in  its  execu- 
tion than  the  angular  saws ;  it  in  fact  works  with  the  most  marvellous  rapidity  and 
precision.  The  staves  and  one  end  of  the  cask  are  then  placed  in  a  machine  formed  of 
iron  rods,  called  a  trussing  machine ;  each  rod  acts  upon  a  separate  stave,  and  the 
whole  of  the  staves  being  equally  compressed  into  a  circle,  the  hoops  are  placed  around 
them,  and  the  cask  is  complete.  The  neatness  and  finish  of  the  work  are  equal  to  what 
a  good  cabinet-maker  can  produce,  every  part  being  true  and  accurate.  The  calcula- 
tion is,  that  15  workmen,  with  the  use  of  this  machine,  can  make  150  casks  a  day; 
whereas  the  same  number  of  persons,  using  only  manual  labor,  could  scarcely  produce 
a  seventh  part  of  that  number.  The  importance  of  the  invention  and  the  application 
of  steam  power  to  it,  may  be  imagined  from  the  fact  that  the  great  brewing  firms  of 
the  metropolis  alone  expend  many  thousand  pounds  annually  in  cooperage,  that  the 
expenditure  of  the  Navy  is  still  greater,  and  that  the  demand  of  the  vintages  of  the 
continent  is  so  great  that  a  great  deal  of  wine  is  lost  from  the  difficulty  of  furnishing 
vessels  to  hold  it.   The  process  of  this  invention  will  repay  the  time  of  a  visit  to  the  works. 

MACLE,  is  the  name  of  certain  diagonal  black  spots  in  minerals,  like  the  ace  of  dia- 
monds in  cards,  supposed  to  proceed  from  some  disturbance  of  the  particles  in  the  act 
of  crystallization. 

MADDER  {Garatiee,  Fr.;  Faberrbthe,  Germ.),  a  substance  very  extensively  used  in 
dyeing,  is  the  root  of  the  Jiubia  tinctorum,  a  plant  of  which  two  species  are  distin- 
guished by  Linnaeus. 

The  best  roots  are  those  which  have  the  size  of  a  writing  quill,  or,  at  most,  of  the 
little  finger.  They  are  semi-transparent,  and  reddish;  have  a  strong  odor,  and  a  smooth 
bark.     They  should  be  of  two  or  three  years'  growth. 

The  madder,  taken  from  the  ground  and  picked,  must  be  dried  in  order  to  be  ground 
and  preserved!  In  warm  climates  it  is  dried  in  the  open  air ;  but  elsewhere  stoves 
must  be  employed. 

The  stringy  falaments  and  epidermis  are  to  be  removed,  called  mulle ;  as  also  the  pith, 
so  as  to  leave  nothing  but  the  ligneous  fibres. 

The  prepaiation  of  madders  is  carried  on  in  the  department  of  the  Rhone,  in  the  fol- 
lowing manner. 

The  roots  are  dried  in  a  stove  heated  by  means  of  a  furnace,  from  which  the  air  is 
allowed  to  issue  only  at  intervals,  at  the  moment  when  it  is  judged  to  be  saturated  with 
moisture.  The  farnace-flue  occupies  a  great  portion  of  the  floor ;  above  are  three  close 
gratings,  on  which  the  roots  are  distributed  in  layers  of  about  two  decimetres  (nearly  8 
inches).  At  the  end  of  24  hours,  those  which  are  on  the  <irst  grated  floor  directly  above 
the  stove  are  dry,  when  they  are  taken  away  and  replaced  by  those  of  the  superior  floors. 
This  operation  is  repeated  whenever  the  roots  over  the  stove  are  dry.  The  dry  roots  are 
thrashed  with  a  flail,  passed  through  fanners  similar  to  those  employed  for  corn,  and  then 
shaken  upon  a  very  coarse  sieve.  What  passes  through  is  farther  winnowed  and  sifled 
through  a  finer  sieve  than  the  first.  These  operations  are  repeated  five  times,  proceeding 
successively  to  sieves  still  finer  and  finer,  and  setting  aside  every  time  what  remains  on 
the  sieve.  What  passes  through  the  fifth  sieve  is  rejected  as  sand  and  dust.  After  these 
operations,  the  whole  fibrous  matters  remaining  on  the  sieve  are  cleaned  with  common 
fanners,  and  women  separate  all  the  foreign  matters  which  had  not  been  removed  before. 
For  dividing  the  roots,  afterwards,  into  different  qualities,  a  brass  sieve  is  made  use  of, 
whose  meshes  are  from  six  to  three  millimetres  in  diameter  (from  ^th  to  |th  inch  E.) 
What  passes  through  the  finest  is  rejected ;  and  what  passes  through  the  coarsest  is  re- 
garded as  of  the  best  quality.  These  roots,  thus  separated,  are  carried  into  a  stove,  of  a 
construction  somewhat  different  from  the  first.  They  are  spread  out  in  layers  of  about 
a  decimetre  in  thickness  (nearly  4  inches  E.),  on  large  lattice  work  frames,  and  the  dry- 
ing is  known  to  be  complete,  when  on  taking  up  a  handful  and  squeezing  it,  the  roots 
break  easily.  On  quitting  the  stove,  the  madder  is  carried,  still  hot,  into  a  machine, 
where  it  is  minced  small,  and  a  sieve  separates  the  portion  of  the  bark  reduced  to  powder. 
This  operation  is  repeated  three  or  four  times,  and  then  the  bolter  is  had  recourse  to. 
What  passes  through  the  sieve,  or  the  brass  meshes  of  the  bolter,  is  regarded  as  com- 

/ 


'  i 


88 


<v 


!  > 


if 


MADDER. 


mon  madder ;  and  what  issues  at  the  extremity  of  the  bolter  is  called  the  flour.      Last.r. 

wT,    ^liTi,        r''"'  '^r°'iS  ^^^  ^^'"'  »^^  ^^^'^'^'^  i"  ^  '"iU  with  vertical  stones,  and 

what^goes  thrJuI^^  '''""'  "'"'  '^''-     ^^^'^  "'^^^^  "^^"^  ^^  ^^^^^^  ^^"^^  ^^^^ 

The  madder  of  Alsace  is  reduced  to  a  very  fine  powder,  and  its  coloring  matter  is  ex- 
tracted by  a  much  longer  ebulUtion  than  is  necessary  for  the  lizari  of  the  Levant  The 
prepared  madders  ought  to  be  carefully  preser^-ed  from  humidity,  because  they  easily  im- 
bibe  moisture,  m  which  case  fermentation  spoils  their  color.  ^  ^ 

D  Ambourney  and  Beckman  have  asserted,  that  it  is  more  advantageous  to  employ  the 
fresh  root  of  madder  than  what  has  been  submitted  to  desiccation,  cspeciaSy  by  means 
^stoves.  But  m  its  states  of  freshness,  its  volume  becomes  troublesome  in  the  dTei^' 
bath  and  uniform  observation  seems  to  prove  that  it  ameliorates  by  age.  Besides  il 
must  be  rendered  suceptible  of  keeping  and  carn'ing  easily.  -oesiaes,  ii 

It  appears  that  madder  may  be  considered  as  composed  of  two  coloring  substances  one 

w^r  ;i  r  ^"^  ^'''^''P^  ^'^^  ^^'  "^^^^  ''  ^^-  ^«t^  «^  '^^'^  substances  may  comWne 
witn  tne  stutt.  it  is  of  consequence,  however,  to  fix  only  the  red  part.  The  dun  nortion 
appears  to  be  more  soluble,  but  its  fixity  on  stuffs  may  possibly  be  increased  by  the  affinTty 
which  It  has  for  the  red  portion.  ^        amuujr 

The  different  additions  made  to  madder,  and  the  multiplied  processes  to  which  it  is 
sometimes  exposed,  have  probably  this  separation  for  their  chief  object. 

The  red  portion  of  madder  is  soluble,  but  in  small  quantity,  in  water.      Hence  but  a 
imited  concentration  can  be  given  to  its  solution.      If  the  portion  of  this  substance  bS 
^  much  increased,  so  far  from  obtaining  a  greater  effect,  we  merely  augment  the  pro! 
portion  of  the  dun  part,  which  is  the  more  soluble  of  the  two  ^ 

I«J2  5°"^^^"^"=^  o^*  the  Societe  Industrielle  of  Mulhausen  having  offered  in  the  year 
1826  large  premiums  to  the  authors  of  the  best  analytical  investigation  of  madder  ei^ht 
memoirs  were  transmitted  to  it  m  the  year  1827.  They  were  examined  with  the  c^'eaies 
care  by  a  committee  consisting  of  able  scientific  and  practical  men.  None  of  th^  com 
petitors  however  fulfi  led  the  conditions  of  the  programme  issued  by  the  societ^-;  but  four 
of  them  received  a  tribute  of  esteem  and  gratitude  from  it ;  MM.  Robiquet  and  Coin  at 
Pars,Kuhmann  at  LiHe,  and  Houton-Libillardiere.  Fresh  premiums  were  offer«l  for 
next  year,  to  the  amount  of  2000  francs.  ""t^reu  lor 

t.  Jlf^  ""^f  discover^'  made  concerning  this  precious  root,  would  be  of  vast  consequence 
to  dyers  and  calico-printers.     Both  M.  Kuhlmann,  and  Robiquet  and  Colin,  conceIvS 
that  they  had   discovered  a  new  principle  in  madder,  to  which   thev  gave  the  na^ 
ahzaruu:.      The  latter  two  chemists  treated  the  powdered  madder  wit'h  sulphuric  acTd 
^mg  care  to  let  it  heat  as  little  as  possible.      By  this  action  the  whole  is  carbonLed 
except  perhaps  the  red  matter.      The  charcoal  thus  obtained  is  pulverized  mked  wfth 

Tm^'^J^r''  ^Z^  ""  ^J^'^r^  ^'^  ^^^^^  i'^  '^'  *=°ld-     l'  ^^  next  S/g?ound,Tnd 
diffused  through  fifty  parts  of  water,  containing  six  parts.of  alum.     This  mkmre^s  then 

boiled  for  one  quarter  of  an  hour,  and  thrown  upon  a  filter  cloth  whUe  boS^J  hot      The 

residuum  is  once  more  treated  with  a  little  warm  alum  water.     The  two  liquo^*are  to 

be  mLxed  and  one  part  of  sulphuric  acid  poured  into  them;  when  thlj  are  XwS  o 

cool  with  occasional  agitation.    Flocks  now  make  their  appearance    the  clear  Cm  i^ 

decanted  and  the  grounds  are  thrown  upon  a  filter.    The^pr^rpUate  is  to  be  washei 

IS  obtamed  in  a  red  or  purple  state.     This  purple  substance,  when  heated  dr,^  give  *out 

mre"Tem"ns''  ^"^^^^""^^^^^  «^'  ^^^^^  ^^  ^^^^  of  animal  mattei ;  whOraXcoaU; 

M.  Dan.  Koechlin,  the  jusUy  celebrated  caUco-printer  of  Mulhausen,  has  no  faith  in 

ft^ouTnnt  h.'  ^^r^  T'^'^Pi"  "^  "^^^^'^ '  "^^  ^^^^«  "^o^^over  that,  Vere  ?t  of  value" 
wo,?lH  1  t  r  "-"  [^^*^4  o'^  the  great  scale,  on  account  of  the  destructive  heat  whS 
would  result  from  the  acd  acting  upon  a  considerable  body  of  the  ground  madder  Their 
o  e'sTft^?"'  %""'^S'^  substance,  as  it  ought  to  be,  if  approximate  prin^rpleT  for  sam' 
tZ      A  °^*^^^tl"  ^"^^'^^^  repetitions  of  the  process  have  produced  very  variable  S- 

Iffo  H  hn  ^'"'"^-r  J^'  '"^^^r'  ^.^  ^^^^"^"'  ^^«^?»^  ri^l^^^  i"^  *^olor  than  those  of  Alsace 
afford  however  httle  or  no  ahzarine.    In  fact,  jncrpuHne,  the  crude  substance  from  whfch 
they  profess  to  extract  alizarine,  is  a  richer  dye  than  this;mre  substance  itseff 

Madder  contains  so  beautiful  and  so  fast  a  color,  that  it  has  become  of  almost 
universal  emplc^ment  in  dyeing;  but  that  color  is  accompanied  with  Tmany  oTheJ 
substances  which  mask  and  degrade  it,  that  it  can  be  brought  out  and  fixed  3y  after  a 

orby'thTrcrofris'th"'  ''"''"'^-  "^f.  P--^--     This  dye  isbesidei^^mti: 

k       ;Jrt  •      ^       *^^^  thrown  away  in  the  dye-house ;  the  portion  supnosed  to  he 

exhausted  being  often  as  rich  as  other  fresh  madder ;  henc^  it  would  be  Tmost  valuable 

Before  the  time  of  Haussmann,  an  apothecary  at  Colmar,  the  madder  bath  was  subject 


I*  2 


MADDER. 


89 


to  many  risks,  which  that  skilful  chemist  taught  dyers  how  to  guard  against,  by  intro- 
ducing  a  certain  quantity  of  chalk  into  the  bath.  A  change  of  residence  led  Haussman 
to  this  fortufate  result.  After  having  made  very  fine  reds  at  Rouen,  he  encountered 
the  greatest  obstacles  in  dyeing  the  same  reds  at  Logelbach  near  Colmar,  where  he  went 
to  live.  Numerous  trials,  undertaken  with  the  view  of  obtaining  the  same  success  in 
his  new  establishment,  proved  that  the  cause  of  his  favorable  results  at  Rouen  existed  in 
the  water,  which  contained  carbonate  of  lime  in  solution,  whilst  the  water  of  Logelbach 
was  nearly  pure.  He  then  tried  a  factitious  calcareous  water,  by  adding  chalk  to  his 
dye  bath.  Haying  obtained  the  most  satisfactory  results,  he  was  not  long  of  producing 
here  as  beautiful  and  as  solid  reds  as  he  had  done  at  Rouen.  This  practice  became 
soon  general  among  the  calico-printers  of  Alsace,  though  in  many  dve-works  the  chalk 
is  now  replaced  by  lime,  potash,  or  soda.  But  when  the  madder  of  Avignon  is  used, 
all  these  antacid  correctives  become  unnecessary-,  because  it  contains  a  sufficient  quantity 
of  carbonate  of  lime ;  an  important  fact  first  analytically  demonstrated  by  that  accurate 
chemist  M.  Henri  Schlumberger  of  Mulhausen.  Avignon  madder  indicates  the  pre- 
sence of  carbonate  of  Ume  in  it,  by  effervescing  with  dilute  acids,  which  Alsace  madder 
does  not. 

M.  Kuhlman  found  a  free  acid  resembling  the  malic,  in  his  analysis  of  madders  But 
his  experiments  were  confined  to  those  of  Alsace.  The  madders  of  Avignon  are  "on  the 
contrary  alkaline,  as  may  be  inferred  from  the  violet  tint  of  the  froth  of  their  infusions  • 
whereas  that  of  the  Alsace  madders  is  yellowish,  and  it  strongly  reddens  litmus  paperl 
This  important  difference  between  the  plants  of  these  two  districts,  depends  entirely  upon 
the  soil ;  for  madders  grown  in  a  calcareous  shelly  soil  in  Alsace,  have  been  found  to  be 
possessed  of  the  properties  of  the  Avignon  madder. 

The  useful  action  of  the  carbonate  and  the  phosphate  of  lime  in  the  madder  of  Avio-non, 
explains  why  madders  treated  with  acids  which  remove  their  calcareous  salts,  without 
taking  away  their  coloring  matter,  lose  the  property  of  forming  fast  dyes.  Many  manu- 
facturers  are  in  the  habit  of  mixing  together,  and  with  advantage,  different  sorts  of  mad- 
jj  r^ ,  Avignon  contains  so  much  calcareous  matter  that,  when  mixed  with  the 
madder  of  Alsace,  it  can  compensate  for  its  deficiency.  Some  of  the  latter  is  so  deficient 
as  to  afford  colors  nearly  as  fugitive  as  those  of  Brazil  wood  and  quercitron.  The  Alsace 
inadders  by  the  addition  of  chalk  to  their  baths,  become  as  fit  for  dyein?  Turkey  reds  as 
those  of  Avignon.  When  the  water  is  verj-  pure,  one  part  of  chalk  ought  to  be  used  to 
hve  or  Alsace  madder,  but  when  the  waters  are  calcareous,  the  chalk  should  be  omitted. 
Lime,  the  neutral  phosphate  of  lime,  the  carbonate  of  magnesia,  oxvde  and  carbonate  of 
rmc,  and  several  other  substances,  have  the  property  of  causing  madder  to  form  a  fast 
dye,  m  like  manner  as  the  carbonate  of  lime. 

The  teniperature  of  from  50°  to  60°  R.  (145°  to  167°  F.),  is  the  best  adapted  to  the 
solution  of  the  coloring  matter,  and  to  its  combination  with  the  mordants ;  and  thus  a 
boiling  heat  may  be  replaced  advantageously  by  the  long  continuance  of  a  lower  tempera- 
ture. A  large  excess  of  the  dye-stuff  in  the  bath  is  unfavorable  in  two  points  of  view  • 
It  causes  a  waste  of  coloring  matter,  and  renders  the  tint  dull.  It  is  injurious  to  allow 
the  bath  to  cool,  and  to  heat  it  again. 

In  a  memoir  pubHshed  by  the  Society  of  Mulhausen,  in  September,  1835  some 
interesting  experiments  upon  the  growth  of  madders  in  factitious  soils  are  related  by 
MM.  KoBchlin,  Persoz,  and  Schlumberger.  A  patch  of  ground  was  prepared  contain- 
ing from  50  to  80  per  cent,  of  chalky  matter,  and  nearly  one  fifth  of  its  bulk  of  good 
horse-dung.  Slips  of  Alsace  and  Avignon  madders  were  planted  in  March  1834  and 
a  part  of  the  roots  were  reaped  in  November  following.  These  roots,  thou'^h  of  only  six 
months  growth,  produced  tolerably  fast  dyes,  nor  was  any  diflerence  observable  between 
Ihe  Alsace  and  the  Avignon  species;  whilst  similar  slips  or  cuttings,  planted  in  a  natural 


non-calcareous  soil,  alongside  of  the  others,  yielded  roots  which' 


gave  fugitive  dyes. 


^  — o •         —      " —  ~    ~7     J  -^—^.^     M.-^^t^%,^      TT  AixvAt     «£Ci  V  c    X  Ui^lllV  c     lives 

others  were  planted  in  the  soU  of  Palud,  transported  from  Avignon,  which  contained 
more  than  90  per  cent,  of  carbonate  of  lime,  and  they  produced  roots  that  gave  still  faster 
dyes  than  the  preceding.  Three  years  are  requisite  to  give  the  full  calcareous  impregna- 
tion to  the  indigenous  madders  of  Avignon. 

As  to  the  function  of  the  chalk,  valuable  observations,  made  long  ago  by  M  Daniel 
Koechlin,  have  convinced  him,  that  the  combination  of  two  different  bases  with  a  coloring 
matter,  gave  much  more  solidity  to  the  dye,  in  consequence,  undoubtedly,  of  a  greater 
insolubility  m  the  compound.  Experiments  recently  made  by  him  and  his  collea^-ues 
above  named,  prove  that  in  all  cases  of  madder  dyeing  under  the  influence  of  chalk  a 
certain  quantity  of  lime  becomes  added  to  the  aluminous  mordant.  In  the  subseuue'nt 
clearing  with  a  soap  bath,  some  of  the  alumine  is  removed,  and.  there  remains  upon  the 
libre  of  the  cloth  a  combination  of  these  two  earths  in  atomic  proportions.  Thus  the 
chalk  is  not  for  the  purpose  of  saturating  the  acid,  as  had  been  supposed,  but  of  forming 
a  definite  compound  with  alumina,  and  probably  also  with  the  fatty  bodies,  and  the  color- 
ing  matter  itself. 

/ 


|!| 


1  ■ 


90 


MADDER. 


The  red  mordants  are  prepared  commonly  in  ALsace,  as  follows : — The  crushed  alum 
and  acetate  of  lead  being  weighed,  the  former  is  put  into  a  deep  tub,  and  dissolved  by 
adding  a  proper  quantity  of  hot  water,  when  about  one  tenth  of  its  weight  of  soda  crystals 
is  introduced  to  saturate  the  excess  of  acid  in  the  alum.  The  acetate  of  lead  is  now  mix- 
ed in  ;  and  as  this  salt  dissolves  very  quickly,  the  reaction  takes  place  almost  instantly. 
Care  must  be  taken  to  stir  for  an  hour.  The  vessel  should  not  be  covered,  lest  its  con- 
tents should  cool  too  slowly. 

The  different  mordants  most  generally  employed  for  madder,  are  detailed  under  Colors. 
in  Calico-Pkinting  and  Mordant. 

Much  mordant  should  not  be  prepared  at  once,  for  sooner  or  later  it  will  deposite  some 
sub-acetate  of  alumina.  This  decomposition  takes  place  even  in  corked  vials  in  the  cold  • 
and  the  precipitate  does  not  readily  dissolve  again  in  acetic  acid.  All  practical  men  know 
that  certain  aluminous  mordants  are  decomposed  by  heating  them,  and  restored  on  coolin*' 
as  Gay  Lussac  has  pointed  out.  He  observed,  that  by  adding  to  pure  acetate  of  alumina' 
some  alum  or  sulphate  of  potash,  the  mixture  acquires  the  property  of  forming  a  precipi- 
tate with  a  heat  approaching  the  boiling  point,  and  of  re-dissolving  on  cooling.  The  pre- 
cipitate is  alumina  nearly  pure,  according  to  M.  Gay  Lussac ;  but^  by  M.  Koechlin's  more 
recent  researches,  it  is  shown  to  be  sub-sulphate  of  alumina,  containing  eight  times  as 
much  base  as  the  neutral  sulphate. 

Madder  dye. — On  account  of  the  feeble  solubility  of  its  coloring  matter  in  water,  we 
cannot  dye  with  its  decoction  ;  but  we  must  boil  the  dye-stuff  along  with  the  goods  to  be 
dyed ;  whereby  the  water  dissolves  fresh  portions  of  the  dye,  and  imparts  it  in  succession 
to  the  textile  fibres.  In  dyeing  with  madder,  we  must  endeavor  to  fix  as  little  of  the  dun 
matter  as  possible  upon  the  cloth. 

Dyeing  on  woo/.— Alumed  wool  takes,  in  the  madder  bath,  a  red  color,  which  is  not 
so  bright  as  cochineal  red,  but  it  is  faster ;  and  as  it  is  far  cheaper,  it  is  much  used  in 
England  to  dye  soldiers'  cloth.  A  mordant  of  alum  and  tartar  is  employed  ;  the  bath  of 
madder,  at  the  rate  of  from  8  to  16  ounces  for  the  pound  of  cloth,  is  heated  to  such  a  de- 
gree that  we  can  just  hold  our  hand  in  it,  and  the  goods  are  then  dyed  by  the  wince,  with- 
out heating  the  bath  more  till  the  coloring  matter  be  fixed.  Vitalis  prescribes  as  a  mor- 
dant, one  fourth  of  alum,  and  one  sixteenth  of  tartar;  and  for  dyeing,  one  third  of  madder, 
with  the  addition  of  a  24th  of  solution  of  tin  diluted  with  its  weight  of  water.  He  raises 
the  temperature  in  the  space  of  an  hour  to  200°,  and  afterwards  he  boils  for  3  or  4  min- 
utes ;  a  circumstance  which  is  believed  to  contribute  to  the  fixation  of  the  color.  The 
bath,  after  dyeing,  appears  much  loaded  with  yellow  matter,  because  this  bar  less  affinity 
for  the  alum  mordant  than  the  red.  Sometimes  a  little  archil  is  added  to  the  madder,  to 
give  the  dye  a  pink  tinge ;  but  this  is  fugitive. 

Silk  is  seldom  dyed  with  madder,  because  cochineal  affor'.s  brighter  tints. 

Dyeing  wi  cotton  atid  linen, — The  most  brilliant  and  fastest  madder  red  is  the  Turkey  oi 
Adrianople.  The  common  madder  reds  are  given  in  the  following  way  : — The  yarn  or 
cloth  is  boiled  in  a  weak  alkaline  bath,  washed,  dried,  and  galled,  by  steeping  the  cotton 
in  a  decoction  of  bruised  galls  or  of  sumach.  Afler  drying,  it  is  twice  alumed ;  for  which 
purpose,  for  every  4  parts  of  the  goods,  one  part  of  alum  is  taken,  mixed  with  l-16th  of 
its  weight  of  chalk.  The  goods  are  dipped  into  a  warm  solution  of  the  alum,  wrung  out, 
dried,  and  alumed  afresh,  with  half  the  quantity.  The  acetate  of  alumina  mordant,  de- 
scribed  above,  answers  much  better  than  common  alum  for  cotton.  After  the  goods  are 
dried  and  rinsed,  they  are  passed  through  the  dye-bath,  which  is  formed  of  |  lb.  of  good 
madder  for  every  pound  of  cotton ;  and  it  is  raised  to  the  boiling  point  by  degrees,  in  the 
space  of  50  or  60  minutes.  Whenever  the  ebullition  has  continued  a  few  minutes,  the 
goods  must  be  removed,  washed  slightly,  and  dyed  a  second  time  in  the  same  way,  with 
as  much  madder.  They  are  then  washed  and  passed  through  a  warm  soap  bath,  which 
removes  the  dun  coloring  matter. 

Holterhoff  prescribes  for  ordinary  madder  red  the  following  proportions : — 20  pounds 
of  cotton  yarn ;  14  pounds  of  Dutch  madder;  3  pounds  of  nut-galls  ;  5  pounds  of  alum  ; 
to  which  I  lb.  of  acetate  of  lead  has  been  first  added,  and  then  s  quarter  of  a  pound  of 
chalk. 

In  the  calico-print  works  the  madder  goods  are  passed  through  a  bran  bath  first,  im- 
mediately after  dj  eing ;  next,  after  several  days  exposure  to  the  air,  when  the  dun  dye  has 
become  oxydized,  and  is  more  easily  removed.  An  addition  of  chalk,  on  the  principles 
explained  above,  is  sometimes  useful  in  the  madder  bath.  If  bran  be  added  to  the  madder 
bath,  the  color  becomes  much  lighter,  and  of  an  agreeable  shade.  Sometimes  bran-water 
is  added  to  the  madder  bath,  instead  of  bran. 

Mrianople  o?"  Turkey  red. — This  is  the  most  complicated  and  tedious  operation  in  the 
art  of  dyeing ;  but  it  produces  the  fastest  color  which  is  known.  This  dye  was  discover- 
ed in  India,  and  remained  long  a  process  peculiar  to  that  country.  It  was  afterwards 
practised  in  other  parts  of  Asia  and  in  Greece.  In  1747,  Ferquet  and  Goudard  brought 
Greek  dyers  into  France,  and  mounted  near  Rouen,  and  in  Languedoc,  Turkey-red 


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dye  works.  In  1765,  the  French  government,  convinced  of  the  importance  of  this 
business,  caused  the  processes  to  be  published.  In  1808,  Reber,  at  Mariakirch,  furnish- 
ed the  finest  yarn  of  this  dye,  and  M.  Kochlin  became  celebrated  for  his  Turkey-red 
cloth. 

Process  for  Turkey. red. —The  first  step  consists  in  clearing  the  yarn  or  cloth  in  alka- 
line baths,  and  dipping  them  in  oily  liquors,  to  which  sheep's  dung  was  formerly  added. 
This  operation  is  repeated  several  times,  the  goods  being  dried  after  each  immersion. 
There  next  follows  the  cleansing  with  alkaline  liquors  to  remove  the  excess  of  oil,  the 
gallinsr,  the  aluming,  the  maddering,  the  brightening  or  removing  the  dun  part  of  the  dye 
by  boiling,  at  a  high  temperature,  with  alkaline  liquid,  and  the  rosing  by  boiling  in  a  bath 
of  salt  of  tin.  We  shall  give  some  details  concerning  this  tedious  manipulation,  and 
the  differences  which  exist  in  it  in  the  principal  dye-works. 

At  Rouen,  where  the  process  was  first  brought  to  perfection,  two  methods  are  pursued, 
called  the  gray  and  the  yellow  course  or  march.  In  the  gray,  the  dye  is  given  immediately 
after  the  cotton  has  received  the  ofty  mordant,  the  gall,  and  the  alum,  as  it  has  then  a 
gray  color.  In  the  yellow  course,  if  is  passed  through  fresh  oils,  alum,  and  galls  before 
the  maddering,  the  cotton  having  then  a  yellow  tint. 

Different  views  have  been  taken  of  the  principles  of  the  Turkey-red  dye,  and  the  ob- 
ject and  utility  of  the  various  steps.  The  most  ancient  notion  is  that  of  animalizing 
the  cotton  by  dung  and  blood,  but  experience  has  proved  that  without  any  animal  matter 
the  finest  color  may  be  obtained.  According  to  Dingier,  the  cotton  is  imbued  with  oil  by 
steepi.ig  it  in  combinations  of  oil  and  soda ;  the  oil  is  altered  by  repeated  dryings  at  a  high 
temperature ;  it  attracts  oxygen  from  the  air,  and  thereby  combines  intimately  with  the 
cotton  fibre,  so  as  to  increase  the  weight  of  the  stuff.  The  dung,  by  a  kind  of  fermenta- 
tion, accelerates  the  oxydizement,  and  hence  crude  oil  is  preferable  to  pure.  In  England, 
the  mucilaginous  oils  of  Gallipoli  are  preferred,  and  in  Malabar,  oils  more  or  less 
rancid.  The  drying  oils  do  not  answer.  The  subsequent  treatment  with  the  alkaline 
liquors  removes  the  excess  of  oil,  which  has  not  been  oxydized  and  combined  ;  a  hard 
drying  completely  changes  that  which  remains  in  the  fibres ;  the  aluming  which  follows 
combines  alumina  with  the  cotton ;  the  galling  tans  the  fibres,  producing  a  triple  com- 
pound of  oil  and  alum,  which  fixes  the  coloring  matter.  The  object  of  the  other  steps 
is  obvious. 

According  to  Wuttich,  the  treatment  with  oil  opens  the  cotton  so  as  to  admit  the  mor- 
dant and  the  coloring  matter,  but  the  oil  and  soap  do  not  combine  with  the  fibres. 
In  the  alkaline  baths  which  follow,  the  oil  is  transfoi-med  into  soap  and  removed; 
whence  the  cotton  should  not  increase  in  weight  in  the  galling  and  aluming ;  the  cotton 
suffers  a  kind  of  tanning,  and  the  saline  parts  of  the  blood  assist  in  fixing  the  madder 
dye. 

The  German  process  improved,  according  to  Dingier,  consists  of  the  following  opera- 
tions:  mordant  of  an  oily  soap  or  a  soapy  liniment,  hard  drying;  alkaline  bath,  drying, 
steeping,  rinsing  away  of  the  uncombined  mordant,  drying ;  galling,  doing ;  alumin**, 
drymg,  sleeping  in  water  containing  chalk,  rinsing ;  madilering,  airing,  rinsing  ;  bright- 
ening with  an  alkaline  boil,  and  afterwards  in  a  bath  containing  salt  of  tin  ;  then  wash- 
ing and  drying. 

The  yarn  or  the  cloth  must  be  first  well  worked  in  a  bath  of  sheep's  dung  and  oil,  com- 
pounded as  follows :— 25  pounds  of  sheep's  dung  are  to  be  bruised  in  a  solution  of 
pure  caustic  potash  of  hydrometer  strength  3°,  and  the  mixed  liquor  is  to  be  passed 
through  a  sieve.  Two  pounds  of  fine  oil  are  now  to  be  poured  into  16  pounds  of  his  ley 
after  which  30  pounds  of  coarse  oil  are  to  be  added,  with  adtation  for  i  of  an  hour' 
Other  4  pounds  of  hot  ley  are  to  be  weU  stirred  in,  till  the  whole  is  homogeneous.  This 
proportion  of  mordant  is  sufficient  for  100  pounds  of  cotton  yarn,  for  90  pounds  of  un- 
bleached or  100  pounds  of  bleached  cotton  goods.  The  cotton  stuff,  after  being  well 
wrung  out,  is  to  be  laid  in  a  chest  and  covered  with  a  lid  loaded  with  weights,  in  which 
state  It  should  remain  for  five  days.  At  the  end  of  24  hours,  the  cotton  becomes  hot  with 
fermentation,  gets  imbued  with  the  mordant,  and  the  oil  becomes  rapidly  altered.  The 
goods  are  next  exposed  freely  to  the  air  during  the  day,  and  in  the  evening  they  are  dried 
in  a  hot  chamber,  exposed  to  a  temperature  of  158°  F.,  for  6  or  8  hours,  which  promotes 
the  oxydizement  of  the  oil. 

The  goods  are  now  passed  the  second  time  through  a  soapy-oil  mordant  similar  to  the 
nrst,  then  dried  in  the  air  by  day,  and  in  the  hot  stove  by  night.  The  third  and  fourth 
oil-soap  steeps  are  given  in  the  same  way,  but  without  the  dung.  The  fifth  steep  is  com- 
posed of  a  ley  at  2°,  after  which  the  goods  must  also  be  dried.  Indeed,  from  the  first  to 
the  fourth  steep,  the  cotton  stuff  should  be  put  each  time  into  a  chamber  heated  tc  U5P 
b.  tor  12  or  15  hours,  and  during  18  hours  after  the  fifth  steep. 

The  uncombined  oil  must,  in  the  next  place,  be  withdrawn  by  the  deeraissaee,  which 
consists  in  steeping  the  goods  for  6  hours  in  a  very  weak  alkaUne  ley.  After  rinsing  and 
wringing,  they  are  dried  in  the  air,  and  then  put  into  the  hot  stove. 

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92 


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The  goods  are  now  galled  in  a  bath  formed  of  36  pounds  of  Sicilian  sumach,  boiled  for 
3  hours  in  260  pounds  of  water,  and  filtered.  The  residuum  is  treated  with  190  fresh 
pounds  of  water.  This  decoction  is  heated  with  12  pounds  of  pounded  nut-galls  to  the 
boiling  point,  allowed  to  cool  during  the  night,  and  used  next  morning  as  hot  as  the  hand 
can  bear ;  the  goods  being  well  worked  through  it.  They  are  again  dried  in  the  air,  and 
afterwards  placed  in  a  stove  moderately  heated.  They  are  next  passed  through  a  tepid 
alum  bath,  containing  a  little  chalk ;  left  afterwards  in  a  heap  during  the  night,  dried  in 
the  air,  and  next  in  the  stove.  The  dry  goods  are  finally  passed  through  hot  water  con- 
taining a  little  chalk,  wrung  out,  rinsed,  and  then  maddered. 

For  dyeing,  the  copper  is  filled  with  water,  the  fire  is  kindled,  and  an  ounce  and  a 
half  of  chalk  is  added  for  every  pound  of  madder ;  a  pound  and  a  quarter  of  madder 
being  taken  for  every  pound  of  cotton  yarn.  The  goods  are  now  passed  throuffh  the  bath, 
so  that  they  penetrate  to  near  its  bottom.  The  fire  must  be  so  regulated,  that  the  copper 
will  begin  to  boil  in  the  course  of  from  2|  to  3  hours ;  and  the  Ebullition  must  be 
contmued  for  an  hour ;  after  which  the  yarn  is  air«d  and  rinsed.  Cloth  should  be  put 
into  the  dye-bath  when  its  temperature  is  77"  and  winced  at  a  heat  of  from  100°  to 
122°  during  the  first  hour ;  at  167°  during  the  second ;  and  at  the  boiling  point  when  the 
third  hour  begins.  It  is  to  be  kept  boiling  for  half  an  hour;  so  that  the  maddering 
lasts  four  hours.  Dingier  does  not  odd  sumach  or  galls  to  the  madder  bath,  because 
their  effect  is  destroyed  in  the  subsequent  brightening,  and  he  has  no  faith  in  the  utility 
of  blood. 

After  being  dyed,  the  goods  are  washed,  pressed,  and  subjected  to  a  soapy  alkaline  bath 
at  a  high  heat,  in  a  close  boiler,  by  which  the  dun  parts  of  the  galls  and  the  madder  are 
dissolved  away,  and  the  red  color  remains  in  all  its  lustre.  This  operation  is  called 
brightening.  It  is  repeated  in  a  similar  liquor,  to  which  some  muriate  of  tin  is  added  for 
the  purpose  of  enlivening  the  color  and  givinff  it  a  rosy  tint.  Last  of  all,  the  goods  are 
rinsed,  and  dried  in  the  shade. 

The  Elberfeld  process  consists  for  100  lbs.  of  the  following  steps  :— 

1.  Cleaning  the  cotton  by  boiling  it  for  four  hours  in  a  weak  alkaline  bath,  cooling  and 
nnsing. 

2.  Working  it  thoroughly  four  times  over  in  a  steep,  consisting  of  300  pounds  of  water 
15  pounds  of  potash,  1  pailful  of  sheep's  dung,  and  12^  pounds  of  olive  oil,  in  which  it 
should  remain  during  the  night.  Next  day  it  is  drained  for  an  hour,  wrung  out  and  dried. 
This  treatment  with  the  dung  steep,  and  drying,  is  repeated  3  times. 

3.  It  is  now  worked  in  a  bath  containing  120  quarts  of  water,  18  pounds  of  potash, 
and  6  quarts  of  ohve  oU;  then  wrung  out  and  dried.  This  steep  is  also  repeated  4 
times. 

4.  Sleeping  for  a  night  in  the  river  is  the  next  process ;  a  sUght  rinsing  without  wrine- 
ing,  and  drying  in  the  air.  ^  * 

5.  Bath  made  of  a  warm  decoction  (100°  F.)  of  sumach  and  nut-galls,  in  which  th« 
goods  remain  during  the  night ;  they  are  then  strongly  wrung,  and  dried  in  the  air. 

*u-    1.    l"™^?^  '^'^^.  addition  of  potash  and  chalk;  wringing;  working  it  well  through 
this  bath,  where  it  IS  left  during  the  night.  =>i  o  o 

7.  Draining,  and  strong  rinsing  the  following  day;  piling  up  in  a  water  cistern. 

8.  Rinsing  repeated  next  day,  and  steeping  in  water  to  remove  any  excess  of  alum 
trom  Uie  fibres ;  the  goods  continue  in  the  water  tUl  they  are  taken  to  the  dyeing-bath. 

y.  Ihe  maddering  is  made  with  the  addition  of  blood,  sumach,  and  nut-gaUs;  the  bath 
IS  brought  to  the  boil  in  1  hour  and  |,  and  kept  boUing  for  half  an  hour. 

10.  The  yarn  is  rinsed,  dried,  boiled  from  24  to  36  hours  in  a  covered  copper,  with  an 
oUy  alkahne  hquid  ;  then  rinsed  twice,  laid  for  two  days  in  clear  water,  and  dried. 

11.  Finally,  the  greatest  brightness  is  obtained  by  boiling  for  three  or  four  hours  in  a 
soap  bath,  containing  muriate  of  tin ;  after  which  the  yarn  is  rinsed  twice  over,  steened 
in  water,  and  dried.  *        * 

Process  0/  Haussmann—Ue  treats  cotton  twice  or  4  times  in  a  solution  of  aluminated 
potash,  mixed  with  one  thirty-eighth  part  of  Unseed  oil.  The  solution  is  made  by  adding 
caustic  potash  to  alum.  He  dries  and  rinses  each  time,  and  dries  after  the  last  operation 
He  then  rinses  and  proceeds  to  the  madder  bath.  For  the  rose  color,  he  takes  one  pound 
01  madder  for  one  pound  of  cotton  ;  for  carmine  red,  he  takes  from  2  to  3  pounds -and 
for  the  deepest  red,  no  less  than  4  pounds.  It  is  said  that  the  color  thus  obtained  sur- 
passes lurkeyred. 

I  ^^t  fo'T^  r^'^'^'^Jiy^  V^  of  Rov^n.-.YxT^\  operation.  Scouring  with  a  soda 
1^^'  "i  A  ^"^T'  ^"^  '^^'"'^  *^^'®  '^  ^^^*"y  *^^^  ^^«  remainder  of  the  whiU  prepara- 
dried  ^^^"^^^^^^  of  oil  and  soda  with  water.     It  is  then  washed,  wrung  out,  and 

In  the   second  operation,  he  states  that  from  25  to  30  pounds  of  sheep's  dung  are 
commonly  used  for  100  pounds  of  cotton  yarn.     The  dung  is  first  steeped  for  some  days 


MADDER. 


9S 


in  a  ley  of  soda,  of  8°  to  10°  B.  This  is  afterwards  diluted  with  about  500  pints  of  a 
weaker  ley,  and  at  the  same  time  bruised  with  the  hand  in  a  copper  basin  whose  bottom 
is  pierced  with  small  holes.  The  liquor  is  then  poured  into  a  vat  containing  5  or  6 
pounds  of  fat  oil  (Gallipoli),  and  the  whole  are  well  mixed.  The  cotton  is  washed  in 
this,  and  the  hanks  of  yarn  are  then  stretched  on  perches  in  the  open  air,  and  turned  from 
time  to  time,  so  as  to  make  it  dry  equably.  After  receiving  thus  a  certain  degree  of  de- 
siccation, it  is  carried  into  the  drying  house,  which  is  heated  to  50°  Reaumur  (144° 
Fahrenheit),  where  it  loses  the  remainder  of  its  moisture,  which  would  have  prevented 
it  from  combining  with  the  other  mordants  which  it  is  afterwards  to  receive.  What  is 
left  of  the  bath  is  called  avancesy  and  is  added  to  the  following  bath.  Two  or  even  three 
dung  baths  are  given  to  the  cotton,  when  it  is  wished  to  have  very  rich  colors.  When 
the  cotton  has  received  the  dung  baths,  care  must  be  taken  not  to  leave  it  lying  in  heaps 
for  any  length  of  time,  lest  it  should  take  fire;  an  accident  which  has  ocl;asionaUy 
happened. 

The  white  bath  is  prepared  by  pouring  6  pounds  of  fat  oil  into  50  pints  of  soda  water 
at  1°  or  sometimes  less,  according  as,  by  a  preliminary  trial,  the  oil  requires.     This  bath 
ought  to  be  repeated  two,  three,  or  even  a  greater  number  of  times,  as  more  or  less  body 
is  to  be  given  to  the  color. 

To  what  remains  of  the  white  bath,  and  which  is  also  styled  avarices,  about  100  pints 
of  soda  ley  of  two  or  three  degrees  are  added.  Through  this  the  cotton  is  passed  as 
usual.  Formeriy  it  was  the  practice  to  give  two,  or  three,  or  even  four  oils.  Now,  two 
are  found  to  be  sufficient. 

The  cotton  is  steeped  for  five  or  six  hours  in  a  tepid  solution  of  soda,  of  1°  at  most  • 
It  is  set  to  drain,  is  then  sprinkled  with  water,  and  at  the  end  of  an  hour  is  washed,  hank 
by  hank,  to  purge  it  entirely  from  the  oil.  What  remains  of  the  water  of  degraissac'e 
serves  for  the  scouring  or  first  operation.  ® 

For  100  pounds  of  cotton,  from  20  to  25  pounds  of  galls  in  sorts  must  be  taken,  which 
are  bruised  and  boiled  m  about  100  pints  of  water,  till  they  crumble  easily  between  the 
fingers.  The  galling  may  be  done  at  two  operations,  dividing  the  above  quantity  of  galls 
between  them,  which  is  thought  to  give  a  richer  and  more  uniform  color. 

The  aluming  of  100  pounds  of  cotton  requires  from  twenty-five  to  thirty  pounds 
of  pure  alum,  that  is  alum  entirely  free  from  ferruginous  salts.  The  alum  should 
be  dissoU-ed  without  boiling,  in  about  100  pints  of  river  or  rain  water.  When  the 
alum  is  dissolved,  there  is  to  be  poured  in  a  solution  of  soda,  made  with  the  sixteenth 
part  of  the  weight  of  the  alum.  A  second  portion  of  the  alkaUne  solution  must  not 
be  poured  in  till  the  effervescence  caused  by  the  first  portion  has  entirely  ceased— and 
so  in  succession.  The  bath  of  saturated  alum  being  merely  tepid,  the  cotton  is  passed 
through  It,  as  m  the  gall  bath,  so  as  to  impregnate  it  well,  and  it  is  dried  with  the  preu 
cautions  recommended  above.  The  dyers  who  gall  at  two  times,  alum  also  twice  for 
like  reasons.  ' 

For  25  pounds  of  cotton,  25  pints  of  blood  are  prescribed,  and  400  pints  of  water. 
Whenever  the  bath  begins  to  warm,  50  pounds  of  madder  are  diffused  through  the 
bath ;  though  sometimes  the  maddering  is  given  at  two  operations,  by  dividing  the  mad- 
der into  two  portions. 

The  brightening  bath  is  prepared  always  for  100  pounds  of  cotton,  with  from  four  to 
five  pounds  of  rich  oil,  sLx  pounds  of  Marseilles  white  soap,  and  600  litres  of  soda  water 
of  2°  B. 

The  rosing  is  given  with  solution  of  tin,  mixed  with  soap  water. 
*u  '^^^  Turkey-red  dye  of  Messrs.  Monteith  and  Co.,  of  Glasgow,  is  celebrated  all  ovei 
the  world,  and  merits  a  brief  description  here. 

The  calico  is  taken  as  it  comes  from  the  loom  without  bleaching,  for  the  natural  color 
of  the  cotton  wool  harmonizes  well  with  the  dye  about  to  be  given ;  it  is  subjected  to  a 
fermentative  steep  for  24  hours,  like  that  preliminary  to  bleaching,  after  which  it  is  wash 
ed  at  the  dash  wheel.  It  is  then  boiled  in  a  ley,  containing  about  1  pound  of  soda  crjs- 
lals  tor  12  pounds  of  cloth.  The  oiling  process  now  begins.  A  bath  is  made  with  10 
gallons  ot  Gallipoh  oil,  15  gallon  measures  of  sheep's  dung  not  indurated ;  40  gaUons  of 
solution  of  soda  crystals,  of  1-06  specific  gravity  ;  10  gaUons  of  solution  of  peSrl-ash  of 
spec.  grav.  1-04;  and  140  gallons  of  water;  constituting  a  milk-white,  soapy  solution  of 
about  spec.  grav.  1-022.  This  liquor  is  put  into  a  large  cylindrical  vat,  and  constantly 
agitated  by  the  rotation  of  wooden  vanes,  which  are  best  constructed  on  the  plan  of  the 
mashing  apparatus  of  a  brewery,  but  far  slighter.  This  saponaceous  compound  is  let  off 
as  wanted  by  a  stopcock  into  the  trough  of  a  padding  machine,  in  order  to  imbue  every 
fibre  of  the  cloth  m  its  passage.  This  impregnation  is  still  more  fuUy  ensured  by  laying 
the  padded  cloth  aside  in  wooden  troughs  during  16  or  18  days.  The  sheep's  dung  has 
been  of  late  years  disused  by  many  Turkey-red  dyers,  both  in  England  and  France,  but  it 
is  lound  to  be  advantageous  in  producing  the  very  superior  color  of  the  Glasgow  estab- 
lishment.    It  is  supposed,  also,  to  promote  the  subsequent  bleaching  during  the  exposure 


>?i 


94 


MADDER. 


on  the  green;  which  is  the  next  process  in  favorable  weather,  but  in  bad  weather  thi. 
goods  are  dried  over  a  hot-flue.  '  weauier  the 

The  cloth  is  padded  again  with  the  saponaceous  liquor ;  and  again  spread  nn  tliP  .rrncc 
The  cloth  by  this  time  is  varnished  as  it  were  with  oil,  and  must  be  cleans«i  in  »  npr 

r,t"  "S^?.!  ..'•'''  "'  'P"='^=  ^'^^'y  ^-O^'  thoroughly  diffused  throi^  170  S  ons  of 
water.    With  this  saponaceous  liquor  the  cloth  is  padded  as  before,  and  then  nass<S  be 

Tr/".,T''""£''"""'^^1'''=''  '^'"™  *«  superfluous  liquor  into  the  pSdLg-troueh 
S^  in  the  s?o,!^.  """  '""  °"  "•"  ^"^^  "■  »"™°'-«i  »»"  «t  any  rate  it  must^ie  S 

ih  JllS^t?'""*™'' ^"'^'"^' '""^ '''^'"S  processes,  are  repeated  three  times:  whereby 

„,ll„      JT^'  once  more  very  oleaginous,  and  must  be  cleansed  again  by  sleeping 

toe  of^^     t7  ''^,'^-  "=7?"'  ""■*  ^"^-^'^  "'"  *«  SP«-  »«v.  1-012,  at  the^emi^m! 

SoThirn^  ha".^"/r '"''"°"  '■"*  '""'  ""  '"  "■'  '■""-  «'  *«  ~«™  fi'™-"'  ^e 

Gfing  is  the  next  great  step  in  the  Turkey-red  preparation;  and  for  its  success  all  the 
oil  should  have  been  perfectly  saponified.        '         ^    ^  '  aamor  us  success  all  tfte 

nn^h^ii?  l^  ^.  ^""fl  ""^  ^^.^PP^  ^^"^  (^^'^  ^«^^  ^00  lbs.  of  cloth)  are  to  be  bruised 
fh.  H^  r  ^*''-  **♦  ""L^  ^"'''  *"  2^  -^"^"^  °^  ^^^^'-^  till  5  gallons  be  evaporated  aS 
the  decoction  is  to  be  then  passed  through  a  searce.     Two  pounds  of  sumach  mkv  be 

r.nf 'tT^  v"  '^'"LT^^  ^^^"^-  "^^  ^°^«  '""^tb^  ^^"  P«<ld<^d  wthTs  decoction' 
kep  at  90°  F.  passed  through  squeezing-roUers,  and  dried.  They  are  then  pass^  throigh 
a  solution  of  alum  of  the  spec.  grav.  1-04,  to  which  a  certain  portion  of  chalkTadded^o 
saturate  the  acid  excess  of  that  super^alt ;  and  in  this  cretaceous  mixture,  heati  to  110° 

ilirdltd'^reTto^e".' ^^"^"^ '"  ''  '°""-    '' ''  ^^^^  P-sedbetween  squee^^roZ; 

The  maddering  comes  next. 

From  two  to  three  pounds  of  madder,  ground  to  powder  in  a  proper  mill,  are  taken 
for  every  pound  of  cloth.  The  cloth,  as  usual  in  maddering,  is  entered  into  the  coW 
Sr^  T?,v  ^^  V^L ^^l«°»^ti%reel  during  one  hour  that  "the  bath  take  to  iSl,  aid 
durmg  an  ebullition  of  two  hours  afterwards.     One  gallon  of  bullock's  blood  is  added  to 

ThVn  T^  r?.'  Tf^  1^-^  ^°^"^'  ^^  *^^°'^ '  ^"^""  "^^  ^"^"'ity  operated  upon  ii  one  bati? 
The  utility  of  the  blood  m  improving  the  color  has  been  ascribed  to  its  coloring  partides  • 
but  It  IS  more  probably  owing  to  its  albuminous  matter  combining  with  the  margarates  of 
soda  and  potash  condensed  m  the  fibres.  s*"*"^!*  oi 

««:^f  "^'^♦^K  '^^'i;?^"^  ?  ^^°=y  brown  coloring  matter  associated  with  the  fine  red,  the 
goods  must  be  subjected  to  a  clearing  process  to  remove  the  former  tinge,  which  is  more 
fugitive  than  the  latter.  Every  hundred  pounds  of  cloth  are  therefore^tiiled  durinTll 
hours  at  least,  with  water  containing  5  pounds  of  soda  crystals,  8  pounds  of  soap  and 
16  gaHons  ol  theresjiual  pearl-ash  and  soda  ley  of  the  last  cleansing  operation.  By  tMs 
powerful  n^eans  the  dun  matter  is  weU  nigh  removed;  but  it  is  completely  so  by  a  second 
boil,  at  a  heat  of  2d0°  F.,  m  a  tight  globular  copper,  along  with  5  pounds  of  soap,  and  1 
pound  of  muriate  of  tm  crystals,  dissolved  in  a  sufficient  body  of  water  for  100  pounds 
of  cloth  The  muriate  of  tin  serves  to  raise  the  madder  red  to  a  scariet  hue.  A  mar- 
garate  of  tin  is  probably  fixed  upon  the  cloth  in  this  operation. 

When  the  weather  permits,  the  goods  should  be  now  laid  out  for  a  few  days  on  the 
grass.  Some  manufacturers  give  them  a  final  brightening  with  a  weak  bath  of  a  chloride 
of  lime ;  but  it  is  apt  to  impoverish  the  color.  «-"iuriae 

According  to  the  latest  improvements  of  the  French  dyers,  each  of  the  four  proces*=es 
aLve!"""'  '"^"^^"^^"^  ^ye*«-   *»d    brightening   differs,  in   some   respects,  from  ie 

1.  Their  first  step  is  boiling  the  cloth  for  four  hours,  in  water  containing  one  pound  of 
soap  for  every  four  pieces.  Their  saponaceous  bath  of  a  creamy  aspect  is  used  a^  a  tern 
pemture  of  TS''  F. ;  and  it  is  applied  by  the  padding  machine  fiUS,  with  tt  ^r^^^^^^^^^ 

fe  s  1l'':%f1r'T'    rV'''''''  ^'""  ^'^  ^«°^^  ^^""^^  ^'  exposed  on  the  gia's  no 
l^ss  than  U  alternations  of  the  saponaceous  or  white  bath  are  employed,  and  8  in  spring! 

They  consider  the  action  of  the  sun-beams  to  aid  greatly  in  brightening  this  dye  •  but  at 

falpab^d'^'"'      '^       cont^"'^^^  ^ore  than  4  hours,  the  scarlet  color  produced  begins  to  be 

They  conceive  that  the  oiling  operation  impregnates  the  fibres  with  super-margarate  of 


ii 


MAGNESIA. 


95 


potash  or  soda,  insoluble  salts  which  attract  and  condense  the  alumina,  and  the  red  color- 
ing particles  of  the  madder,  so  firmly  that  they  can  resist  the  clearing  boil. 

2.  Their  second  step,  the  mordanting,  consists  first  in  padding  the  pieces  through  a  de- 
coction of  galls  mixed  with  a  solution  of  an  equal  weight  of  alum  ;  and  after  drying  in 
the  hot-flue,  &c.,  again  padding  them  in  a  solution  of  an  acetate  of  alumina,  made  by 
decomposing  a  solution  of  16  lbs.  of  alum  with  16  lbs.  of  acetate  of  lead,  for  6  pieces  of 
cloth,  each  32  aunes  long. 

3.  The  maddering  is  given  at  two  successive  operations ;  with  4  pounds  of  Avignon 
madder  per  piece  at  each  time. 

4.  The  brightening  is  performed  by  a  12  hours'  boil  in  water  with  soda  crystals,  soap, 
and  salt  of  tin  ;  and  the  rosing  by  a  10  hours'  boil  with  soap  and  salt  of  tin.  Occasion- 
ally, the  goods  are  passed  through  a  weak  solution  of  chloride  of  potash.  When  the  red 
has  too  much  of  a  crimson  cast,  the  pieces  are  exposed  for  two  days  on  the  grass  which 
gives  them  a  bright  scarlet  tint. 

Process  of  M.  Werdet  to  dye  broadcloth  and  wool  by  madder  : — 
"  Preparation  for  24  pounds  of  scoured  wool : 

"Take  4^  pounds  of  creaHi  of  tartar,  4 J  pounds  of  pure  alum;  boil  the  wool  gently 
for  2  hours,  transfer  it  into  a  cool  place,  and  wash  it  next  day  in  clear  water. 

"Dyeing. — 12  pounds  of  Avignon  madder,  infused  half  an  hour  at  30°  R.  (100°  F.) 
Put  into  the  bath  1  pound  of  muriate  of  tin,  let  the  color  rose  for  three  quarters  of  an 
hour  at  the  same  heat,  and  drain  or  squeeze  the  madder  through  canvass.  The  whole  of 
the  red  dye  will  remain  upon  the  filter,  but  the  water  wLich  has  passed  through  will  be 
as  deep  a  yellow  as  a  weld  bath.  The  boiler  with  the  Jye  must  now  be  filled  up  with 
clear  river  water,  and  heated  to  100°  F.  Two  ounces  of  the  solution  of  the  tartar  and 
alum  must  be  poured  into  it,  and  the  wool  must  be  turned  over  in  it  for  an  hour  and  a 
half,  while  the  heat  is  gradually  raised  to  the  boiling  point.  The  wool  is  then  removed 
and  washed.     It  must  be  rosed  the  following  day. 

"  Rosing.— Dissolve  in  hot  water  1  pound  of  white  Marseilles  soap  ;  let  the  bath  cool, 
and  pass  the  wool  through  it  till  it  has  acquired  the  desired  shade;  15  or  20  minutes  are 
8ufl5cient.     On  coming  out  of  this  bath  it  should  be  washed. 
**  Solution  of  deuto-muriate  of  tin : — 

"  2  ounces  of  pure  muriatic  acid ;  4  drachms  of  pure  nitric  acid  ;  1  ounce  of  distilled 
water.  Dissolve  in  it,  by  small  portions  at  a  time,  2  drachms  of  grain  tin,  in  a  large 
bottle  of  white  glass,  shutting  it  after  putting  in  the  tin.  This  solution  may  be  preserved 
for  years,  without  losing  its  virtue." 

I  have  inserted  this  piocess,  as  recently  recommended  by  the  French  minister  of  com- 
merce, and  published  by  M.  Pouillet  in  vol.  i.  of  his  Portefeuille  Indusfriel,  to  show  what 
official  importance  is  sometimes  given  by  our  neighbors  to  the  most  frivolous  things. 
MADREPORES  are  calcareous  incrustations  produced  by  polt/pi  contained  in  cells  of 
greater  or  less  depth,  placed  at  the  surface  of  calcareous  ramifications,  which  are  fixed  at 
their  base,  and  perforated  with  a  great  many  pores.  The  mode  of  the  increase,  repro- 
duction, and  death  of  these  animals  is  still  unknown  to  naturalists.  Living  madrepores 
are  now-a-days  to  be  observed  only  in  the  South  American,  the  Indian,  and  the  Red  seas  • 
but  although  their  polypi  are  not  found  in  our  climate  at  present,  there  can  be  no  doubt 
of  their  having  existed  in  these  northern  latitudes  in  former  times,  since  fossil  madrepores 
occur  in  both  the  older  and  newer  secondary  strata  of  Europe. 

MAGISTERY  is  an  old  chemical  term  to  designate  white  pulverulent  substances, 
spontaneously  precipitated  in  making  certain  metallic  solutions;  as  magistery  of 
bismuth. 

MAGISTRAL,  in  the  language  of  the  Spanish  smelters  of  Mexico  and  South 
America,  is  the  roasted  and  pulverized  copper  pyrites,  which  is  added  to  the  ground 
ores  of  silver  in  their  patio,  or  amalgamation  magma,  for  the  purpose  of  decomposin<» 
the  horn  silver  present.  See  Silver,  for  an  account  of  this  curious  process  of 
reduction. 

MAGMA  is  the  generic  name  of  any  crude  mixture  of  mineral  or  organic  matters  in 
a  thin  pasty  state.  ' 

MAGNANIER  is  the  name  given  in  the  southern  departments  of  France  to  the  pro- 
prietor of  a  nursery  in  which  silk-worms  are  reared  upon  the  great  scale,  or  to  the  mana<»er 
of  the  establishment.  The  word  is  derived  from  magnansy  which  signifies  silk-worms'in 
the  language  of  the  country  people.     See  Silk. 


MAGNESIA  (Eng.  and  Fr. ;  Bittererde,  Talkerde,  Germ.) 


is  one  of  the  primitive 


earths,  first  proved  by  Sir  H.  Davy  to  be  the  oxyde  of  a  metal,  which  he  called  mag~ 
nesium.  It  is  a  fine,  light,  white  powder,  without  taste  or  smell,  which  requires  5150 
parts  of  cold  water  and  no  less  than  36,000  parts  of  boiling  water  for  its  solution.  Its 
specific  gravity  is  2-3.  It  is  fusible  only  by  the  heat  of  the  hydroxysen  blowpipe.  A 
natural  hydrate  is  said  to  exist  which  contains  30  per  cent,  of  water.     Magnesia  changes 

/ 


i!i 


m 


im 


96 


MAGNET  NATIVE. 


the  purple  infusion  of  red  cabbage  to  a  bright  green.  It  attracts  carbonic  acid  from  tnc 
air,  but  much  more  slowly  than  quicklime.  It  consists  of  61-21  parts  of  metallic  basis 
and  38-79  of  oxygen ;  and  has,  therefore,  20  for  its  prime  equivalent  upon  the  hydrogen 
scale.  Its  only  employment  in  the  arts  is  for  the  purification  of  fine  oil  in  the  prepara- 
tion of  varnish.  ' 

Magnesia  may  be  obtained  by  precipitation  with  potash  or  soda,  from  its  sulphate 
commonly  called  Epsom  salt ;  but  it  is  usually  procured  by  calcining  the  artificial  or 
natural  carbonate.    The  former  is,  properly  speaking,  a  subcarbonate,  consistin*'  of  44-69 
magnesia,  3586  carbonic  acid,  and  19-45  water.     It  is  prepared  by  adding  to  the  solution 
of  the  sulphate,  or  the  muriate  (the  bittern  of  sea-salt  evaporation  works),  a  solution  of 
catbonate  of  soda,  or  of  carbonate  of  ammonia  distilled  from  bones  in  iron  cylinders. 
The  sulphate  of  magnesia  is  generally  made  by  acting  upon  magnesian  limestone  with 
somewhat  dilute  sulphuric  acid.      The  sulphate  of  lime  precipitates,  while  the  sulphate 
of  magnesia  remains  in  solution,  and  may  be  made  to  crystallize  in  quadrangular  prism's 
by  suitable  evaporation  and  slow  cooling.     Where  muriatic  acid  may  be  had  in  profusion 
for  the  trouble  of  collecting  it,  as  in  the  soda  works  in  which  sea  salt  is  decomposed  by 
sulphuric  acid,  the  magnesian  limestone  should  be  first  acted  upon  with  as  much  of  the 
former  acid  as  will  dissolve  out  the  lime,  and  then,  the  residuum  being  treated  with  the 
latter  acid,  will  afford  a  sulphate  at  the  cheapest  possible  rate ;  from  which  ma<»nesia  and 
aU  Its  other  preparations  may  be  readUy  made.     Or,  if  the  equivalent  quantity  of  calcined 
magnesian  hmestone  be  boiled  for  some  time  in  bittern,  the  lime  of  the  former  will  dis- 
place the  magnesia  from  the  muriatic  acid  of  the  latter.      This  is  the  most  economical 
process  for  manufacturing  magnesia.    The  subcarbonate,  or  7nagnesia  alba  of  the  apolh 
ecary,  has  been  proposed  by  Mr.  E.  Davy  to  be  added  by  the  baker  to  damaged  flour  u 
counteract  its  acescency.  ' 

MAGNESIAN  LIMESTONE  {Dolomie,  Pr.  ;  Bitterialk,  Talkspath,  Germ.),  is  a 
mineral  which  crystalizes  in  the  rhombohedral  system.  Spec.  grav.  2.86;  scratches 
calc-spar ;  does  not  fall  spontaneously  into  powder,  when  calcined,  as  common  limestone 
does.  It  consists  of  1  prime  equivalent  of  carbonate  of  lime  —  50,  associated  with  1 
of  carbonate  of  magnesia  =  42. 

Massive  magnesian  limestone,  is  yellowish-brown,  cream-yellow,  and  yellowish-gray; 
brittle.  It  dissolves  slowly  and  with  feeble  effervescence  in  dilute  muriatic  acid;  whence 
it  is  called  Calcaire  leyit  dolomie  by  the  French  mineralogists.    Specific  gravity  2-6 

Near  Sunderland,  it  is  found  in  flexible  slabs.  The  principal  range  of  hills  com- 
posing this  geological  formation  in  England  extends  from  Sunderland  on  the  northeast 
coast  to  Nottingham,  and  its  beds  are  described  as  being  about  300  feet  thick  on  the  east 
of  the  coal  field  in  Derbyshire,  which  is  near  its  southern  extremity.  On  the  western 
side  of  the  Cumberland  mountains  magnesian  limestone  overlies  the  coal  measures  near 
Whitehaven.  The  stratification  of  this  rock  is  very  distinct,  the  individual  courses  of 
stone  not  exceeding  in  general  the  thickness  of  a  common  brick. 

The  lime  resulting  from  the  calcination  of  magnesian  limestone  appears  to  have  an 
injurious  action  on  vegetation,  unless  applied  in  quantities  considerably  less  than  com- 
mon lime,  when  it  is  found  to  fertilize  the  soil.  After  two  years,  its  hurtful  influence 
on  the  ground  seems  to  become  exhausted,  even  when  used  in  undue  quantity.  Great 
quantities  of  it  are  annually  brought  from  Sunderland  to  Scotland  by  the  Fifeshire 
farmers,  and  employed  beneficially  by  them  as  a  manure,  in  preference  to  other  kinds 
of  hme.  It  has  been  unfairly  denounced,  by  Mr.  Tennent  and  Sir  H.  Davy,  as  a 
sterilizer. 

This  rock  is  used  in  many  places  for  building;  indeed,  our  most  splendid  monument  ol 
Gothic  architecture,  York  Minster,  is  constructed  of  magnesian  limestone. 

MAGNESIA,  NATIVE  (Brucite ;  Guhr-magnesien,  Fr.;  Wasseitalk,  Germ.),  is  a 
white,  lamellar,  pearly-looking  mineral,  soft  to  the  touch.  Spec.  grav.  2-336 ;  tender ; 
scratched  by  calc-spar ;  affording  water  by  calcination  ;  leaving  a  white  substance  which 
browns  turmeric  paper;  and,  by  calcination  with  nitrate  of  cobalt,  becoming  of  a 
lilach  hue.  It  consists  of  69-75  magnesia,  and  30-25  water.  It  occurs  in  veins  in  the 
serpentine  at  Hoboken,  in  New  Jersey,  as  also  at  Swinaness,  in  the  island  of  Unst, 
Shetland. 

MAGNESITE,  Giobertite ;  native  carbonate  of  magnesia  occurs  in  white,  hard,  stony 
masses,  in  the  presidency  of  Madras,  and  in  a  few  other  localities.  It  dissolves  very 
slowly  in  muriatic  acid,  and  gives  out  carbonic  acid  in  the  proportion  of  22  parts  by 
weight  to  42  of  the  mineral,  according  to  my  experiments,  and  is  therefore  an  atomic  car- 
bonate. It  forms  an  excellent  and  iDeautiful  mortar  cement  for  terraces ;  a  purpose  to 
which  it  has  been  beneficially  applied  in  India  by  Dr.  Macleod. 

MAGNET,  NATIVE,  is  a  mineral  consisting  of  the  proloxyde  and  peroxyde  of  iron 
cwnbined  in  equivalent  proportions.    See  Ibon. 


MALT. 


9T 


liqnor'^^el^;.ii"'*  ?    '^^  ^^"^^  Tl^'  ^  ^^'^^  ^^^^  ««  ^^"  ^  -  fermented 

^ALACmTE  o^^^^^^      /  •         'P'-'^'  ^5  "^'"'y  ««ltivated  in  our  gardens. 

color  with  varLafVr^^  "^^'^"  carbonate  of  copper  of  a  beautiful  green 

MtJ^^r^^T^T^^  saline  compounds  with  the  bases,  with 

iui^'mfn^Litii:^^^^^^^^^      -:i^:ird^K  r 

acids;  and  occasionally  combined  with  potash  or limTuw^^^ 
the  berries  of  the  mountain  ash,  elderberries  cnvvlntt' ^oTXJF    I      T'  ^^.^b^""^^^. 
berries,  bilberries,  brambleberries,  whorUeberriircWries   an^^^^^^^  strawberries,  rasp- 
the  houseleek  and  purslane  contain  the  malate  of  lime  ^  ^''"^  "^^^'^  *''^' 

The  acid  may  be  obtained  most  conveniently  from  thp  iiuVa  nf  fi.«  v      •        t  xi. 

by  recrystallization.     On  dissolving  the  white  Lkfnw  7       ''^i^  ^^^^^^  ^°*^  P""^^^ 

tured  upon  the  great  scale.  purposes,  but  it  has  not  hitherto  been  manufac- 

an  a^tmeiaPp"^^^^^^^^^^^^  -^-h  has  been  subjected  to 

The  Quantity  of  Malt  consumed  by  the  undermentioned  Brewers  of  London  and  its 
Vicinity,  from  10th  October,  1830,  to  10th  October,  1842. 


Barclay  and  Co.  - 
Hanbury  and  Co. 
Whitbread  and  Co. 
Reid  and  Co. 
Meux  and  Co.     - 
Combe  and  Co.  - 
Calvert  and  Co.  • 
Hoare  and  Co.     - 
Elliot  and  Co.     • 
Thome,  T.  and  Son 
I  Charrington  and  Co. 
{Steward  and  Co.  • 
{Taylor  and  Co.    - 
Coding,  J.  and  Co. 
Coding,  Thomas  - 
Ramsbottom  and  Co. 
Broad  wood  and  Co. 
Gardner,  H.  W.  and  P 
Mann,  James 
Courage  and  Co. 
Wood  and  Co.     - 
More,  Robert 
Harris,  Thomas  - 
Hazard  and  Co.  - 
Tubb,  William    - 
Richmond  and  Co. 
Hodgson  and  Co. 
Abbott,  E.    •        . 
Manners  and  Co. 
Halo,  George 
Halford  and  Co.        ) 
Kempson  and  Co.      { 
Farren  and  Till  - 
Thome.  J.  M.  and  Son 
Duggan  and  Co.  - 
Gaskell  and  Downs    - 

VolU. 


1831. 


Qrs. 

97,198 

50,724 

49,713 

43,38U 

24,339 

34,684 

30,525 

24,102 

19,444 

1,445 
10,531 

8,116 
21,845 
16,307 

9,987 


1832. 


6,666 

8,116 
5,469 
2,535 

4,778 


V. 


3,785 
4,206 


Qrs. 
9ti,612 
58,512 
53,541 
44,420 
22,062 
36,948 
32,812 
26,821 
20,061 
2,.'>43 

9,648  ; 

6,872  i 
21,735 
14,874 
8,971 


1833. 


4,584 
3,215 


5,904 
1,056 
7,6(17 
5,560 
1.040 
4,780 
6,126 

3,503 
3,522 


Qrs. 
93.175 

58,497 
50,067 
40,810 
20,716 
36,5)70 
31,433 
25,407 
19,899 
5,136 

15,617 

21,115 

14,279 

7,630 


1834. 


4,328 
3,187 

3,139 


7,471 

1,332 

7,546 

5,54 

1,890 

4,540 

6,203 

3.256 
3,870 


Qrs. 
99,674 
74,982 
49,105 
44,210 
26,161 
35,438 
31,460 
29,796 
25,009 

8,496 

18,197 

20,835 

15,256 

8,824 


11,429 
1,757 
8,079 
7,602 
4,713 
4,940 
7,094 
80 
3,520 
2,080 


1835. 

Qrs. 
106,098 
78,087 
55,209 
49,430 
24,376 
36,922 
33,263 
31,525 
28,728 
10,913 

19,213 


1S36.   1837. 


Qrs. 
108,715 
89,303 
53,694 
49.831 
30,775 
42,169 
30,859 
32,623 
28,338 
12,657 

19,445 


23,885  24,971 
16,312  J  3,321 


1838. 


7,618 


14,699 
2,780 
8,790 
7,320 
4,130 
4,964 

200 
3,268 
2,414 


3,633 
3,330 


3,217 


3,261 
3.545 


11,784 
115,364 


15,369 
4,840 
9,2.39 
7,961 
5,255 
4,998 
6,597 
1,516 
3,551 
3,400 


Qrs 
100,326 
61,440 
47.012 
42,700 
30,623 
40,454 
32,325 
32,347 
24,150 
16,404 

18.842 

23,556 
1114,023 
7,095 
15,227 


3,4661    3,768 
-     3,763 


4,046 

-     2,201 

-I-  -J 


15,256 
6.588 
9,286 
7,834 
6,025 
5,042 
6,674 
2,826 
3,174| 
2,400 

4,552 
4,547 


4,783 

2,665 
-1- 


Qrs. 
107,455 
90,140 
45,460 
44,928 
35,065 
43,444 
31,529 
31,278 
22,486 
18,545 

20,290 

27,320 

14,028 

7,551 

13,012 

16,921 
10,326 
10,723 
8,506 
6,129 
5,888 
6,552 
3,365 
4,058 
1,790 

6,121 
5,039 
4,685 


1839. 


4,599 
2,288 


Qrs. 
114,827 
91,069 
51,979 
44,010 
38,466 
40.712 
31,028 
31,008 
22,990 
19,578 

18,688 

25,955 

12,145 

I  5,758 

10,610 

17,504 

11,599 

10,456 

7,607 

6,413 

5,256 

6,250 

4,060 

4,.536 

5,358 

7,030 
4,816 
3,96 


1840. 


1841. 


Qrs. 
115,561 
98,210 
63,622J 
48,130 
40,767 
38,368 
30,872 
30,310 
25,367 
20,664 

18,328 

27,300 

18,517 

14,630 

15,559 

11,679 

11,532 

7,194 

6,954 

5,152 

6,729 

4,478 

4,964 

5,704 


Qrs. 
106,345 
88,132 
51,457 
47,980 
49,797 
36,460 
30,614 
29,450 
25,379 
22,413 

17,840 

21,424 

16,018 


4,400 
3,0?^ 


5,334 
4,443 
3,585 

4,425 

3,001 


15,791 

13,126 

12,111 

12,328 

7,268 

7,175 

5,291 

5,758 

4,944 

5,030 

5,862 

4,819 
4,418 

3,155 

3,^0 
3/5^ 


'?l 


1^2. 

Qrs. 
114,090 
92,466 
52,098 
50,120 
43,340 
40,484 
30,660 
29,607 
27,050 
22,022 

20,42S 

19,430 

17,071 

16,688 
14,546 
13,53<; 
13,016 
7,65t 

7,oa« 

6,022 
5,556 
5,503 
4,424 

4,983 
4,831 
4,468 

3,878 

3,676 

U54 


1 


""5BBBIS 


Ill 


I 


m 


d 


98 


MALT. 


NAME. 


Ma  Leod,  B.   - 
Plimmer ... 
Laxton  and  Bryan  - 
Draper  and  Co. 
Miller  and  Co. . 
Keene  and  Co. 
Lane  and  Bowden  - 
Fleming  and  Co. 
Clarke,  Charles 
Garney,  J.  and  Co. 
Stains  and  Fox 
Verey,  W.  and  G.    - 
Jones,  T.  -        - 

Hcrington  and  "Wells 
Hill  and  Kice  - 
Holt  and  Sons  - 
Cox,  John 
Griffith,  P. 
UflFord  and  Co. 
Masterman  and  Co. 
Johnson  and  Co. 
Wyatt      - 
Turner,  R.        -       - 
Dickenson,  G.  - 
Honeyball,  Edward 
Jenner,  li.  and  II.    - 
Church,  J.  L.  . 
Blo2<',  B.  -        . 

M'l^od,  J.  M.  and  Co. 
Satchell  and  Son 
Knight     . 
Chadwick,  "W. 
Turner,  John  - 
Locke,  R.         .       - 
Hume,  George 
Collins,  W.L. - 
West,  J.  H.      - 
Mantell  and  Son 
Addison   -       -       . 
Martin  and  Co. 
Allan 

Hood  and  Co.  - 
Clarke,  W.  - 
Clarke,  8. 

Bye,  W.  and  H.       - 
Clarke      - 
Rudge      -       .       - 
Bricheno,  Henry 
Lamont  and  Co. 
Filmer  and  Gooding 
Wood  and  Co. 
Brown,  late  Hicks  - 
Manvell,  Isaac 
Abbott,  E. 
Cooper,  W.       -        - 
Saunders 
West,  J.  W.     - 
Harris,  Robert 


1831. 


Qrs. 
1,656 


4,048 


814 


2,285 
585 


2,910 
1,113 
2,302 
2,146 

1,704 


98 
901 


603 


1882. 


Qrs. 
2,947 


3,020 


857 


1,332 
463 


1,748 

754 

2.279 

1,530 

1,808 


2,608 


674 

1,018 
206 
846 
187 
756 


722 


646 


6,687 
1,646 


752 
691 
244 


128 
719 

202 

684 


1833. 


Qrs. 

4,236 


2,941 


1,006 


2,168 
844 
837 


1,974 

717 

4,371 

1,063 

1,830 


218 
801 
269 
855 

694 


1884. 


Qrs. 
5,479 


8,508 


1,008 


2,266 

1,140 

875 


1,963 
794 

2,446 

1.693 
208 

1,810 


8,117 


1,906 


584 
99 
986 
176 
577 
840 
690 


640 
259 
975 
254 
824 
914 
696 


841 


271 


876 


719       780 


6,782     7,120 
856       888 


713 


924 
526 
448 

179 
451 


841 
793 
471 
629 

752 


1885. 


Qrs. 

5,860 


4,187 


1,006 


8,106 

1,208 

248 


2,042 
784 

2,499 

2,120 
472 

1,877 


1886. 


Qrs. 

4,689 


5.573 


1,249 


3,738 

1,302 

700 


2,615 


677 
422 
1,427 
441 
822 
850 
668 


488 


933 


747 


9,950 
657 


884 
654 
199 

255 
49U 


681 
888 
800 
784 

968 

2,147 


709 
496 
1,266 
519 
406 
757 
621 


1,872 
813 
2,018 
2,324 
781 
1,789 
2,809 


716 
1,037 
1,103 

772 

756 
1,067 

746 
2,177 


786 
620 
1,235 
527 
406 
807 
619 


671 


839 


793 


706 


837 
853 


9,762     9,885 

403;    2,085 

-     1,089 


834  805 
654  2,805 
199       810 


406 1 
6571 


295 
497 


1887. 


Qrs. 
4,960 


8,583 


88 
1,330 


1,783 

1,578 

956 


1,853 
756 
2,151 
2,221 
953 
1,914 
2,809 


1838. 


Qrs. 

4,700 


8,167 


712 

1,025 

1,512 

888 

742 

943 

820 

1,441 


898 

1,787 
1,624 

3,749 
7.735 

7,888 

1,911 

846 

1,991 

1,884 
1,291 
1,847 
2,428 


1839. 


1840. 


897 
1,010 
1,714 

925 

672 
1,006 

978 
1,481 


169 
766 
651 
1,126 
598 
565! 
693, 
768 
3971 


861 
821 
725 
1,060 
407 
749 
650 
812 
501 


649 


741 
201 

884 


9,863 
8,600 
1,298 


824 
560 
815 

806 
870 


681 


768 
260 
983 

8,867 
6,251 
1,291 


756 
441 
370 
81 
251 
466 


Qrs. 

4,300 

3.213 
1,658 

855 
2,826 
1,275 
1,796 
1,848 

614 
2,072 
1,749 
1,665 
1,638 
1,8.35 

307 
1,861 
1,653 
1,241 
1,789 
2,412 


1,018 

1,020 

1,402 

856 

975 

1,148 

877 

1,476 

5.S2 
853 
760 
812 
862 
594 
694 
637 
649 


504 

547 
846 

886 

8,699 

7,6.38 

1,674 

1,493 

1,851 

679 

812 

434 

811 

290 

405 


Qrs. 
8,410 
783 
2,658 
1,711 
1,167 
2,84') 
1,964 
2,159 
1,934 
1,908 
2,406 
1,762 
1.879 
1,905 
1,677 
1,093 
1,723 
1.916 
i;201 
1,672 
2,413 


1841. 


1,077 

1,100 

1,055 

929 

949 

1,034 

782 

1,308 

78 

775 

728 

776 

791 

620 

627 

723 

72 

592 


694 
462 
450 
433 

655 

13,475 

1,683 
1,442 
1,450 
7.S2 
487 
603 
862 
853 
447 


Qrs. 
8,805 
1,653 
2,579 
1,787 
1,740 
2,646 
2,010 
2,417 
2,124 
2.597 
2,628 
1,826 
1,810 
1,746 
1,697 
972 
1,628 
1,419 
1.850 
1,892 
2,204 

1,219 

1,092 

1,053 

955 

1,049 

1,118 

797 

1,063 

888 

820 

768 

765 

718 

627 

708 

&41 

638 

637 
644 
506 
502 
489 

449 

18,087 

1,614 
1,484 
1,800 
770 
490 
485 
471 
444 
441 


Quantity  of  Malt  which  paid  Duty,  and  Amount  of  Duty,  in  the  Years  1842  to  1846. 


1842. 


Qrs. 

8,125 
8,001 
2.797 
2,777 
2.685 
2,445 
2,4.32 
2,256 
2,255 
2,211 
2,050 
1.840 
1,808 
1,806 
1,628 
1,583 
1,520 
1,429 
1,860 
1,295 

1,267 

1,264 

1,135 

1,087 

1,067 

1,066 

1,046 

1,026 

945 

866 

846 

754 

787 

708 

706 

702 

660 

642 

640 
624 
629 
520 
510 

501 


England  - 
Scotland  - 
Ireland   - 

Total     - 

Quantity. 

Amount  of  daty.                                 1 

j 

1842.           1848. 

1844. 

1845. 

1843. 

1848. 

1844 

1845. 

Qimrters. 

8,654,850 

484.778 
130,297 

Quarters. 

8,850,567 
446,220 
162,886 

Quarter*. 

8,979,020 
478,562 
159,655 

Quarters. 

8,925,871 
543,596 
218,020 

1 

8,959.420 
625,176 
141,156 

4,171,417 
483,405 
176,459 

4,810,605 
518,442 
172,970 

4,253,027 
588,895 
236,196 

4,269,926 

4,459,673 

4,617,247 

4,687,487 

4,626,761 

4,831,811 

5,078,118     5,078,118 

Quantity  of  Malt  wetted  in  Public  Brewing  in  the  United  Kingdom  in  the 

undermentioned  years. 

QFARTERS.!  QTTABTKBS. 

-  3,566,300,1850     -       -       5,188,617 

-  8,701,70711851  (10  months)  4,868,118 

-  8,749,1241 


QITARTKRS. 

QUARTERS. 

1887     - 

4,030,5iM 

1840     - 

-        8,9;^5,272 

1843 

lass   - 

.        4,040,395 

1841     - 

-        8,678,013 

1844 

1889     - 

4,082,368 

1842     - 

-        8,688,477 

1845 

MALT. 


99 


An  Account  of  the  Quantities  of  Malt  brewed  by  the  Twelve  principal  London  Porter 
and  Ale  Brewers,  during  the  Five  Years  ending  with  October,  1842  (from  Slater's 
Brewers  Malt  List). 


issa 


1889. 


Barclay  <fe  Co.    - 
Hanbury  <fe  Co.  - 
Whitbread  <fe  Co. 
*Reid  &  Co. 
*Meux  <fe  Co. 
Combe  <fe  Co. 
Calvert  <fe  Co.     - 
Hoare  <fe  Co. 
Elliot  &  Co. 
Charrington  <fe  Co. 
Taylor  <fe  Co.      - 
Courage  <fe  Co.  - 


Qrs. 
107,455 
90,140 
46,460 
44,928 
35,065 
43,444 
31,529 
31,278 
22,000 
20,290 
27,320 
10,723 


Qrs. 
112,276 
91,069 
61,979 
44,010 
38,465 
40,712 
31,028 
31,008 
22,990 
18,688 
2.5,955 
10,456 


1840. 


Qrs. 

115,561 

98,210 

53,622 

48,1.30 

40,787 

38,368 

30,872 

30,310 

25,255 

18,328 

27,300 

11,532 


1841. 


Qrs. 
106,345 
88,132 
51,457 
47,980 
39,797 
36,460 
30,615 
29,450 
25,379 
17,840 
21,424 
12,328 


1842. 


*  Those  marked  thus  *  brew  porter  only. 


Qrs. 
114,090 
92,469 
62,098 
60,120 
40,340 
46,484 
30,660 
29,607 
27,060 
20,423 
19,530 
13,016 


Quarters  of  Malt  consumed  in  the  undermentioned  Years,  ending  10th  October. 


By  the  Brewers  of  London  and  its  Vicinity. 


lasi 

1832 


622,549 
604,477 


isas 

1834 


578,588 
662,718 


1835 
1836 


702,533 
754313 


1837 
1838 


714,488 
742,597 


1839 
1840 


750,176 
776,219 


1&41 
1842 


734,295 
741,651 


By  the  Twelve  principal  Brewers  of  London. 


1831 
1882 


432.521 

438,046 


1833 

1834 


427,087 
470,123 


1836 
1836 


503,048 
626,092 


18.37 
1833 


490,179 
617,940 


1839 
1840 


628,259 
547,908 


1841 

1842 


617,292 
641,710 


Table  of  the  Quantity  of  Malt  from  Barley,  which  paid  Duty  in 


TearsL 


1834 

1835 

1836 

1837 

1838 

1839 

1840 

1841 

1842 


England  and  Wales. 


Bushels. 
34,449,646 
36,078,855 
37,196,998 
33,692,356 
33,823,958 
33,826,016 
36,653,442 
30,956,394 
30,796,262 


Scotland. 


Ireland. 


Bushels. 
4,491,292 
4,459,553 
4,903,187 
4,583,045 
4,419,141 
4,360,363 
4,397,304 
4,058,249 
3,786,476 


£ 

1834 

4,449,745 

18.35 

4,660,185 

1836 

4,804,612 

1837 

4,351,929 

1838 

4,368,931 

1839 

4,369,193 

1840 

4,841,229 

1841 

4,198,460 

1842 

4,176,742 

Amount  of  Duties  Paid : 
£ 
553,567 
551,096 
611,910 
578,515 
557,913 
652,107 
572,544 
539,572 
603,829 


Bushels. 

2,204,653 

2,353,645 

2,287,636 

2,275,347 

2,262,440 

1,744,550 

1,406,116 

1,149,692 

1,268,656 


£ 

272,291 
288,602 
288,857 
286,470 
284,954 
218,503 
178,703 
151,210 
168,009 


Exports  in  1850,  182,480  barrels:  in  1851,  191,639  barrels: 
558,794^.,  in  1851,  577,874/. 


declared  value,  1860, 

/ 


100 


MALT. 


ii: 


I, 


.Hi 


MALT.    British  beer  brewing  is  sadly  oppressed  by  fiscal  folly  and  ignorance.   The 
regulations  as  to  the  manufacture  of  malt  are  embodied  in  the  acts  7  <fe  8  Geo.  4,  c.  52, 
and  11  Geo.  4,  c.  17.     The  former  act  is  an  admirable  specimen  of  legislative  injustice; 
the  latter  was  intended  to  ameliorate  the  provisions  of  its  predecessor,  and  does,  in  a 
degree,  effect  that  object     The  first  contams  no  less  than  83  clauses;  and  the  regula- 
tions in  it,  though  frequently  repugnant  to  the  plainest  principles  of  common  sense,  are, 
nevertheless,  enforced  by  106  penalties,  amounting  in  the  aggregate  to  the  incredible 
sum  of  13,500/.     How  much  of  this  is  negatived  by  the  subsecjuent  act  it  is  not  very 
easy  to  determine,  though,  as  far  as  it  goes,  the  effect  of  No.  2  is  to  stultify  the  regula- 
tions of  ^'o.  1.     Woe  to  that  man,  however,  who  begins  the  manufacture  of  malt  with- 
out having  duly  studied  these  incompatible  acts.     Having  been  favored  with  a  perusal 
of  the  genuine  "instructions  for  officers  who  survey  maltsters,"  a  clear  insight  may  be 
had  into  the  actual  practice  of  the  excise;  for  our  copy  is  duly  emblazoned  with  the 
arms  of  England,  and  marked  "  by  authority ; " — being,  moreover,  of  so  late  a  date  as 
1842,  it  offers  unexceptionable  evidence.     The  necessary  apparatus  for  the  production 
of  malt  is  extremely  simple, — that  is  to  say,  a  cistern  for  steeping  the  grain ;  a  floor  in 
which  it  may  be  suffered  to  heat  and  vegetate ;  and,  lastly,  a  stove  or  kiln  in  which  the 
newly-formed  malt  may  be  dried.     Specific  size,  or  force,  or  other  arrangement,  there 
needs  none ;  and  such  is  actually  the  condition  of  the  malt  manufacture  in  most  coun- 
tries at  this  day.     With  us,  however,  a  very  different  system  prevails  ; — the  cistern  or 
steeping  vessel  must  be  of  a  determinate  form  and  construction ;  it  must  have  been  ap- 
proved of  by  a  supervising  officer;  its  cubical  contents  must  have  been  very  accurately 
ascertained,  by  actual  admeasurement,  and  it  must  be  placed  in  such  a  situation  that 
the  officer  gauging  it  may  have  sufficient  light,  and  a  clear  open  space  of  48  inches,  at 
the  least,  above  every  part  of  such  cistern,  for  the  purpose  of  facilitating  the  process  of 
gauging ;  and,  lastly,  it  such  light  be  an  impossibility,  from  local  obstacles,  the  malt- 
ster must  enter  into  an  engagement  to  keep,  at  his  own  expense,  lamps  or  caudles  burn- 
ing, for  the  convenience  of  the  officer.     From  what  we  have  now  said,  as  well  as  from 
the  notoriously  uncertain  character  of  grain,  it  might  naturally  be  inferred,  that  the 
process  of  steeping  would  be  left  entirely  to  the  judgment  of  the  maltster,  who  would 
determine  according  to  his  experience,  and  the  nature  of  the  resulting  phenomena,  when 
the  grain  had  been  steeped  long  enough  in  the  water  and  when  it  had  not.     The  law, 
however,  allows  him  no  such  privilege ;  whether  the  grain  be  old  and  dry,  or  new  and 
moist,  is  all  one, — "  maltsters  are  required  to  keep  their  corn  or  grain  covered  with 
water  for  the  full  space  of  40  hours,  under  the  penalty  of  100/."    jNor  will  any  change 
occurring  in  the  appearance  of  the  grain,  and  seeming  to  require  its  immediate  removal, 
justify  or  excuse  tfie  maltster  in  so  doing,  unless  indeed  he  shall  have  anticipated  the 
occurrence,  by  giving  notice  of  his  intention  to  do  so  in  his  original  notice  "  to  wet" — 
which  must  date  24  hours  previously  to  commencing  that  operation, — and  give  the  day 
and  hour  of  the  day  for  beginning  the  steep, — all  under  the  usual  penalty  of  100/. 
Nor  may  he  "  begin  to  wet  at  any  other  time  than  between  the  hours  of  8  in  the  morning 
and  2  in  the  afternoon,"  under  a  penalty  of  100/.,  nor  may  he  take  corn  or  grain  from  any 
cistern  at  any  other  time  than  between  the  hours  of  7  in  the  morning  and  4  in  the  after- 
noon.    To  empty  corn  or  grain  out  of  any  cistern  until  the  expiration  of  96  hours  from 
the  time  of  the  last  preceding  emptying  of  any  cistern  in  the  establishment  involves  a 
penalty  of  200/. ;  and  the  same  infliction  occurs,  "if  the  corn  or  grain  be  not  emptied 
out  of  all  such  cisterns  at  one  and  the  same  time,  or  within  three  hours  after  the  clear- 
ing of  the  first  cistern  was  commenced." 

Maltsters  are  not  to  mix,  either  on  the  floor  or  kiln,  any  corn  or  grain  of  one  wetting 
with  corn  or  grain  of  another  wetting,  under  a  penalty  of  100/.  What  is  termed  the 
coucli,  or  place  in  which  the  grain,  after  being  steeped,  is  laid  together  for  the  purpose 
of  germination,  is  a  supplementary  apparatus  of  excise  ingenuity,  and  no  way  neces- 
sary to  the  success  of  the  malting  process.  Here  the  grain,  after  having  been  gauged 
in  the  steep,  is  again  to  be  gauged  with  great  care ;  and  if  the  ninltster  should  tread  or 
compress  the  couch,  so  as  to  diminish  its  bulk,  a  penalty  of  100/.  is  imposed,  though  it 
is  obvious  that  a  power  of  loosening  or  compressing  this  couch  according  to  its  temper- 
ature would  greatly  improve  the  formation  of  malt.  However,  "  all  corn  or  grain 
emptied  into  the  couch  frame  is  to  be  laid  flat  and  level  by  the  maltster,  and  so  kept 
for  24  hours  at  the  least,"  and  similarly  the  floors  are  all  to  be  placed  level  on  pain  of 
100/.  fine,  so  that  any  experimental  essay  at  improvement  is  very  likely  to  end  in  the 
Court  of  Exchequer.  Again,  it  frequently  happens,  or  rather  we  should  say  it  gener- 
ally happens,  that  too  little  water  is  absorbed  by  the  grain  during  the  operation  of 
steeping;  the  consequence  of  which  is,  that  after  being  removed  from  the  couch  to  the 
floor,  the  grain  desiccates,  and,  ceasing  to  germinate,  speedily  evolves  a  sickly  odor,  and 
becomes  mouldy, — the  incipient  radicles  at  the  same  time  drying  and  shrinking  up  for 
want  of  moisture :  in  fact  the  grain  withers  and  perishes  from  the  eftect  of  drought. 
This  condition    is  yevy  frequent  about   the  third   and   fourth  day  from  the   couch. 


MALT. 


101 


and  is  easily  and  effectually  put  a  stop  to  by  the  application  of  a  little  water.     But  now 
comes  a  rather  awkward  dilemma  for  the  maltster:  if  the  grain  continue  on  the  floor 
without  being  sprinkled,  it  is  greatly  damaged  or  altogether  spoilt ;  if  water  be  sprinkled 
upon  It  to  restore  vitality,  the  law  says,  that  "corn or  grain,  making  into  malt,  must 
not  be  wetted  or  sprinkled  with  water  before  the  expiration  of  12  days,  or  288  hours, 
after  the  same  shall  have  been  taken  from  or  out  of  the  cistern,  under  a  penalty  of  200/." 
Where,  however;  the  steep  has  lasted  for  the  full  period  of  50  hours  and  where,  conse 
quently,  the  want  of  water  is  less  likely  to  be  felt,  the  maltster  may  sprinkle  at  the  end 
of  SIX  days,  or  144  hours  ;  but  in  no  case  less  tlian  this,— though,  as  we  have  stated, 
the  great  urgency  for  the  sprinkling  process  occurs  generally  on  the  third  day;  and  it 
is  an  undeniable  fact,  that  in  spite  of  the  heavy  risk  incurred,  maltsters  do  almost 
invariably  sprinkle  their  floors  at  about  this  period,  and  are  thus  driven  to  the  necessity 
of  trusting  in  the  good  faith  and  discretion  of  some  favorite  workmen,  to  the  infinite 
injury  of  both  parties.     But  the  vast  discriminating  power  confided  to  excise  ofiicers  in 
these  matters  is  positively  incredible.   "Whenever  there  shall  be  reason  to  suspect,  from 
the  appearance  of  the  grain  on  the  floor,  that  it  has  been  illegally  wetted  or  sprinkled, 
the  officer  must  give  immediate  notice  to  the  maltster,  or  his  servant,  of  such  suspicion, 
and  make  a  memorandum  thereof  upon  the  specimen  paper,  and  in  the  memorandum* 
book,  mentioning  whether  anything,  and  what  was  stated  by  such  maltster,  or  any 
person  on  his  behalf"  <fec.     Nay,  the  jaundiced  views  of  the  officer  are  ordered  to  be  put 
on  record,  as  to  an  immense  number  of  fortuitous  circumstances,  all  of  which,  of  course, 
receive   an  unfavorable  signification :  for  instance,  "how  the  kiln  was  loaded,  and 
whether  fed  by  a  brisk  or  slow  fire  ?— whether  the  house  seemed  in  a  state  for  running 
or  wetting,  or  committing  any  other  and  what  fraud  ?— what  the  trader  says,  and  what 
character  he  bears  in  his  concerns  with  the  revenue  ?"— and  so  on,  in  the  most  arbi- 
trary and  unconstitutional  spirit  imaginable.     Indeed,  lest  any  doubt  should  exist 
concerning  the  opinion  which  the  excise  authorities  entertain  towards  the  trade  in 
general,  the  officer  is  specially  instructed  to  make  sudden  and  unexpected  returns 
or  visits,  at  unusual  periods,  "which  we  call  doubling  on  them,"  so  as  to  discover  any 
suspicious  indications.     Again,  of  the  three  separate  gauges  of  malt  which  he  may  take 
whether  in  the  cistern,  in  the  couch,  or  on  the  floor,  the  oflicer  must  select  the  largest  for 
charging  duty  upon.     Tims,  if  in  the  cistern  he  finds  78i  bushels  indicated  in  the  couch, 
subsequently  8U  indicated,  and  on  the  floor  83i,  then  the  latter  is  preferred;  and  so 
with  regard  to  the  highest  wherever  found— the  order  being  that  "when  the  cistern  or 
couch  gauge  is  equal  to  or  exceeds  the  floor  gauge,  then  the  best  cistern  or  couch  gauge 
will  be  the  charge ;  but  if  that  be  less  than  the  floor  gauge,  then  the  floor  gauge  will 
be  the  charge."    Any  accident  or  loss  arising  after  the  cistern  gauge,  is  therefore  thrown 
wholly  on  the  maltster,  who,  far  from  being  able   to  employ  his  ingenuity  in  the 
improvement  of  his  business  processes,  finds  himself  more  than  fully  occupied  in  a  per- 
petual eflfort  to  protect  his  interests  from  the   rapacious  grasp  of  fiscal  regulations 
conceived  in  the  most  hostile  spirit  to  that  industry  by  which  alone  they  exist.     The 
malice,  carelessness,  or  ignorance  of  common  workmen  may  at  any  moment  subject  the 
most  honest  maltster  in  the  kingdom,  not  merely  to  charges  of  dishonesty  but  even  to 
penal  inflictions ;  which  have  ceased  to  carry  moral  degradation  with  them  only  because 
Of  the  popular  belief  of  their  gross  injustice.  It  would  be  impossible,  nor  is  it  requisite 
to  follow  out  or  recapitulate  the  innumerable  annoyances  to  which  the  manufacturer  of 
malt  18  subjected  at  present :  we  have  thus  briefly  noted  down  a  few,  in  order  that  the 
admirers  of  Bavarian  and  other  foreign  beers  may  take  into  account  the  very  different 
state  of  the  malt  manufacture  in  this  country,  as  compared  with  that  brought  about 
by  an  unrestricted  liberty  to  use  or  apply  any  means  which  the  nature  of  the  grain 
the  condition  of  the  atmosphere  or  other  accidental  circumstances,  may  require  durini 
the  process  of  germination.  J      ^  & 

Before  quitting  this  subject,  there  are,  however,  two  considerations  that  require  no- 
tice. Ihe  first  of  these  is  the  peculiarly  unwise  regulation  of  allowing  no  drawback  of 
the  malt  duty  upon  exported  ale  or  beer,  unless  the  same  shall  have  been  brewed  from 
wort  at  a  specific  gravity  of  not  less  than  1054.  Now,  in  most  of  our  colonies,  and  in 
all  warm  climates,  beer,  to  be  agreeable  and  refreshing,  should  be  weaker  than  this 
minimum  gravity.  In  fact,  a  specific  gravity  of  1-047  forms  by  far  the  best  beverage 
for  exportation  to  a  tropical  country,  as  it  is  not  only  less  heady  in  its  eftects  but  fer- 
ments more  kindly  and  completely  than  in  a  heavier  wort,  and  when  well  hopped  is  not 
liable  to  secondary  fermentation.  Nevertheless,  beer  of  this  kind,  brewed  in  this 
country,  and  exported,  suflfers  under  the  expense  of  the  malt  duty,  and  has  to  compete 
m  the  markets  of  our  own  colonies,  as  well  as  in  the  neutral  markets  of  other  countnesL 
with  ales  brewed  by  American  bre  wei-s,  who  pay  no  duty.  The  result,  of  course,  is,  that 
thesupply  of  these  weak  beers  has  passed  entirely  out  of  the  hands  of  English  brewers. 

The  employment  of  malt  in  the  rearing  of  cattle  is  the  other  consideration  to  which 
we  alluded.     This  has  been  hitherto  totally  prevented  by  the  excessive  duty -^or 


i 


'i. 


i  i 


i'^l 


m^ 


'i 


102 


MALT. 


though  some  very  absurd  experiments  have  been  made,  with  a  view  to  decide  the  res- 
pective merits  of  malt  and  bariey  aa  nutritive  agents,  yet  the  only  question  which 
physiology  points  out  as  interesting  and  beneficial,  remains  without  even  the  semblance 
of  a  trial.     Malt,  in  a  dry  state,  differs  little  or  nothing  from  bariey,  except  in  the  pos- 
session of  an  extremely  minute  quantity  of  a  substance  called  diastase;  but  as  diastase 
cannot  exert  its  peculiar  powers,  excepting  under  the  influence  of  water  and  a  some- 
what high  temperature,  the  only  conclusion  to  be  drawn  from  the  experiments  made 
in  feeding  cattle  on  malt,  is  that  the  experimentalists  were  profouDdly  ignorant  res 
pecting  the  most  important  elements  involved  in  the  investigation.     If,  therefore,  such 
experiments  have  proved  that  malt  is  no  better  than  its  equivalent  in  barley,  for  the 
fattening  of  cattle,  we  can  only  say  that  this  fully  equals  our  expectations,  for  there  can 
be  no  doubt  that  the  heat  evolved  during  the  malting  process  has  robbed  the  grain  of 
a  portion  of  carbon,  which  is,  consequently  lost  to  the  feeder  of  cattle.     Malt  cannot 
equal  its  equivalent  of  barley  in  nutritious  power,  unless  we  take  advantage  of  the  dias- 
tase it  contains  to  render  soluble,  and  therefore  more  easy  of  asaimilation,  not  only 
its  own  starch,  but  also  the  farinaceous  ingredients  of  other  kinds  of  food.  When  ground 
malt,  or  a  portion  of  diastase  and  water,  are  digested  with  starch,  or  anything  contain- 
ing it,  at  a  temperature  of  170°  Fahr.,  the  starch  rapidly  dissolves,  and  gradually  passes, 
first,  into  gum  or  dextrine,  and  then  into  sugar.     Thus,  for  example,  if  potatoes  be  mixed 
with  a  tenth  of  their  weight  of  powdered  malt,  and  the  whole  subjected  to  the  action 
of  water,  treated  as  above,  the  resulting  products  will  be  gum  and  sugar  in  a  soluble 
state ;  and,  consequently,  in  that  condition  best  of  all  suited  to  relieve  or  assist  any 
digestive  imperfection  in  the  animal  economy.    Indeed,  the  process  of  digestion  may 
then  be  said  to  have  commenced,  ere  the  food  had  reached  the  stomach  of  the  aninaaJ, 
and  theelfects  of  diastase,  heat  and  moisture,  applied  externally,  substitute  the  action 
of  the  gastric  juice  within.     For  young  or  sickly  animals,  or  those  which  it  is  desired  to 
bring  forward  speedily  to  perfection,  the  use  of  malt,  applied  thus,  cannot  fail  to  ensure 
the  most  beneficial  results.   The  nutritive  powers  of  gum  and  sugar  are  very  well  known 
to  physiologists,  the  first  being  largely  used  as  food  by  the  Moors,  Bosjesmen  of  South- 
ern Africa,  and  the  inhabitants  of  Sendar  in  Dongolia;  amongst  whom  "six   ounces 
of  gum  are  found  sufficient  for  the  daily  support  of  an  adult,"  according  to  Jackson ; 
whilst  in  respect  to  sugar,  it  is  (juite  notorious  that,  though  the  labor  to  the  negroes,  du- 
ring the  sugar  season,  is  excessive,  they  nevertheless  become  extremely  fat  at  that  time 
from  the  nutritive  quality  of  the  sugar  they  consume.    If;  therefore,  it  is  desired  to  ascer- 
tain the  true  value  of  malt,  in  aiding  the  digestive  power  of  an  animal,  it  is  clear  that  this 
can  be  done  only  by  taking  advantage  of  the  catalytic  agency  of  the  diastase  it  contains, 
and  which  seems  so  closely  to  resemble  the  animal  principle  "pepsine,''  to  the  influence 
of  which  the  action  of  the  gastric  juice  is  now  almost  universally  ascribed  by  chemists. 
Nor  would  there  be  the  sliglitest  difficulty  in  carrying  this  improvement  into  practice 
as  most  large  farmers  now  prepare  hot  mashes  for  their  cattle ;  though  these  are,  for 
the  most  part,  unwisely  made  from  carrots,  turnips,  and  such  like  vegetables  as  contain 
gum  and  sugar  ready  foi-med  by  nature  ;  whereas  the  indication  points  to  those  of  a 
starch  kind,  where  the  nutritive  matter  is  insoluble  and  therefore  liable  to  pass  away 
from  the  animal  un assimilated.     True,  indeed,  the  malt  duty  offers  an  impediment ;  but 
the  admitted  suffering  of  the  agricultural  interest  is  a  powerful  instrument  of  honesty 
in  a  just  cause,  and  a  drawback  is  no  novelty  to  the  Exchequer,     There  is,  however,  an 
objection   of  a  social  and  moral  character  to  be   urged  against  the  malt  duty  which 
appears  altogether  unanswerable.    From  what  we  have  stated  concerning  the  action 
of  diastase,  it  must  be  obvious  that  a  mixture  of  barley  and  malt  would  make  quite  as 
good  a  wort  as  malt  alone ;  that  is  to  say,  one  part  of  malt  and  seven  parts  of  bariey 
mashed  together  would  afford  a  wort  exactly  resembling  that  from  eight  parts  of  malt 
alone.    Thus,  then,  by  taking  advantage  of  his  scientific  knowledge,  the  brewer  might 
diminish  his  malt  dutv  to  one-eighth,  or  even  less;  but  this  the   law  will  not  allow, 
though,  in  foreign  countries,  it  may  be  and  is  done,  even  though  the  difference  in  cost 
between  barley  and  malt  is  but  trifling  in  such  places.     But,  strange  to  say,  that  which 
the  legislature  denies  to  the  brewer,  it  freely  accords  to  the  distiller,  who  may  use  a 
mixture  of  malt  and  barley,  in  any  proportion  he  pleases  ;  thus  indicating  that  ardent 
spirits  are  less  injurous  to  the  social  status  of  the  lower  ordei-s  than  beer— a  perfectly 
untenable  line  of  argument,  but  failing  which,  necessitates  the  conclusion  that  little  heed 
is  taken  of  the  moral  sanity  of  the  nation,  so  long  as  the  vices  of  the  people  tend  to 
replenish  the  exchequer.     Having  thus  thrown  together  a  few  remarks  calculated  to 
explain  the  mode  in  which  the  excise  duty  on  malt  interferes  with  the  industrial  d^ 
velopement  of  Great  Britain,  we  refer  to  the  article  Beer  for  the  peculiar   changes 
which  occur  from  the  mash-tun  to  the  finished  product,  as  "fined'   for  the  market 
Let  us  here,  however,  notice  the  fact,  that  malt  differs  very  largely  indeed  in  the  amount 
of  its  available  constituents,  which,  by  analysis,  may  be  shown  to  range  from  about 
62  to  70  of  soluble  extract  per  cent,— the  average  compo«ition  being  aa  under:— 


MALT. 


108 


Moisture 
Insoluble  matter 
Soluble  extract 


6-5 
66-8 


fh^i'^Td^  't  a  remarkable  illustration  of  the  benumbing  effect  of  excise  interference, 
that,  though  these  great  differences  exist,  yet  no  process  of  anal vsis  in  aLnflTK^  o^t 
brewerothepresentday.  other  than  theuLrtain^rdi^^^^^^^ 

equivocal  guidance  of  weight  per  bushel,-for  it  cannot  be  called  specific  IraX 
Therefore,  although,  in  some  of  our  large  breweries  not  less  than   perham  ^(5)000 

Tuf o7  i%r  au::;^^^''^  r^  ^r-"^^^  r^r'^^^  -p-  wMck^wtiXqiaHhe 

vaiue^ol  1,000  quarters),  3^et  no  attempt  is  made,  by  direct  experiment  before  buviniy 
portioaally  given  for  bad  than  for  good  m\ltTandC^4:r; Lid  f  t"tl^^^^^^^ 

Th.  Inn    f     ^K,  ^^t  '''^''^'  ^H  estimates  being  those  of  an  eminent  London  brewed 
The  following  table,  however,  which  shows  their  real  value  as  found  bv  an^U  «?«  I 
monstrates  the  total  incorrectness  of  the  above  method  _  ^  analysis,  de- 


No.  1  yielded    - 
No.  2     - 
No.  3     - 


Moisture. 
•      6-8 
91 
6-7 


Insoluble  matter. 
27-6 
24-9 
27-1 


Extract 
65-7 
66-0 
97-2 


So  that  the  sample  reported  to  be  the  worst  is  actually  that  which  afford*,  ih^  lo^^n«f 
amount  of  extract,  though  it  seems  that  No  2  is  the  LltrnZfLTt-    *^V  T®* 

heat  of  boiling  water,  in  an  OTen  or  compartment  surrounded  bv  that  fluid   Tfh^  .nl 
l/r  'T^r:?^  "  'S"-'  .""^  ■•'''  ■■«''<""«  ">e  quanUV  of  Sre t^e^ent  ^n  tSe 

sequently,  if,  from  the  total  weights  100,  we  deduct  that  of  tW  m^cf,^™!  ^  \  ??" 
matter,  the  remainder  must  re,?resent  the  propo^ln  of  Ic^ublH^^^^  ^^S 

words,  the  saccharine  value  of  the  malt.    This,  as  we  have  stated  mil  kI  ?l 

rste^^riva-^L-rr;- 

brewer"87lbri'r"b'"  YV'!"  l"""''  "' ^6  gallins,  beooTe*  rt^feuSaS  o  thJ 
Drewei,  87  lbs.  per  barrel,  which,  however  merelv  mean«  fl,nf  *u^  ^     ""guH^e  oi  me 

ter  of  malt,  if  evaporated  down  to  the  bulk  ofTbar^e'  or  la^  ^^  ^"""^  ^T""  ^  ^l"*^" 
lbs.  more  than  a  barrel  of  water  As  a  rule  594  lh,'f?  ^1&^^«^^  ^'>^^^  weigh  87 
brewers'  pounds,  or  give  a  barrel  otrorthkvinV a  Ved^t^^^^^^^  '' 

There  are  some  doubts  as  to  the  effect  of  retdninrmLlt  fn  a  bTuTsed  or  now'^^-  ^ 
state  for  any  considerable  period  prior  to  mashing.  %  a  few  brewed  tWs  IZZ^ 
hurtful,  though  the  majority  seem  to  regard  it  as  indifferenT     wIT  ^%<5eemed 

practical  experiments  oi  thiLubject,  an!  find  thTt,  ^  "  ^7 

process  of  mashing  is  rather  improved  than  otherwise  bv  exposTnJf  h^tf ?  TS\\^'^ 
of  the  air,  as,  by  this  means,  it  not  only  attracts  moistLeTom  the  LT^^  ?  '  ^'^^-^ 
thereby  more  easily  commingled  with  the  water  in  he  mashTun  b.ttTn^  r""'  %"!" 
gluten  seems  also  oxidized  by  this  exposure  •    and  hpn^fo  fi  *,    P''''^''''' ""^  ^^'^ 

produced.  A  three  months'  e^xpo^ir:Tbrised  maH  had  nofaraflfni:  TeitCk" 
Quantity  or  quality  of  the  extract  in  our  exneriments     li^Txlt       "^  f ^^^"^  *^^ 

^.plesLod'e  of  leterminingthe  v'SuT'of^KTotd  be^to^^l":  ^Kt^^^lt 


V* 


iiii 


104 


MALT  KILN. 


■■1  i 


a,| 


iM 


ii.' 


and  then  ascertain  the  specific  gravity  of  the  solution,  but,  from  the  circumstances  pre- 
Tiously  stated,  this  cannot  be  done,  as  water  continues  to  combine  chemically  with  tha 
extract  until  nothing  but  sugar  exists,  and  this  would  require  many  hours'  exposure  to 
a  regulated  temperature ;  hence,  the  process  above  given  is  both  the  most  exact  and 
the  most  expeditious.     In  mashing,  much  depends  upon  the  kind  or  strength  of  wort 
required,  as  well  as  upon  the  circumstance  whether  table  beers  and  strong  beers  are 
brewed  in  the  same  establishment,  or  merely  strong  beers  alone.     Any  wort  weighing, 
in  the  language  of  the  brewer,  less  than  16  lbs.,  is,  properly  speaking,  a  table  or  small 
beer  wort.     The  wort  of  the  common  porter,  drunk  in  this  town,  or  London  beer, 
weighs  20  lbs.,  and  the  strongest  bottling  stout  is  about  35.     Some  of  the  Burton  and 
Scotch  ales  run,  however,  as  high  as  38  lbs.     Under  Brewing,  the  means  are  pointed 
out  by  which  any  given  sample  of  ale  or  beer  may  be  analyzed  so  as  to  determine  ex- 
actly the  weight  of  the  wort  from  which  it  was  brewed.     At  present,  however,  we 
must  turn  our  attention  to  the  wort  as  existing  in,  and  flowing  from,  the  mash-tun.   In 
a  general  way,  about  10  gallons  of  water  may  be  taken  tor  every  bushel  of  malt  in  the 
first  mash ;  and,  after  well  mixing  the  two  together,  the  whole  should  be  closely  cov- 
ered down  for  three  hours,  ere  any  attempt  is  made  to  draw  off  the  wort.     It  is  imma- 
terial whether  the  water  be  added,  to  the  malt,  or  the  malt  to  the  water ;  but  the  tem- 
perature of  this  latter  is  of  great  importance.     In  mild  or  warm  weather  a  heat  of  175® 
Fahr.  is  sufficient;  but,  in  winter,  180°  will  be  requisite,  as  the  malt  then  cools  down 
the  average  heat  more  than  in  summer ;  in  either  case,  the  temperature,  after  mixing, 
should  not  exceed  nor  fall  much  short  of  170°  Fahr.     At  the  expiration  of  three  hours, 
this  wort  may  be  withdrawn  into  a  proper  vessel,  or  under-back,  where  it  must  be 
kept  warm.     Its  specific  gravity  should  be  about  1*092,  or  weigh  33  lbs.  per  barrel 
more  than  water.     So  soon  as  the  first  wort  has  been  withdrawn  (and  the  quantity  of 
which  is  seldom  more  than  fths  of  the  water  employed),  another  portion  of  water  must 
be  poured  upon  the  malt,  in  the  ratio  of  about  eight  gallons  to  the  bushel  of  malt  em- 
ployed, and  of  a  temperature  somewhat  higher  than  the  first     After  standing  two 
hours  this  is  drained  away,  like  the  first,  when  a  quantity  of  boiling  water  is  slowly 
trickled  down  upon  the  grains  from  an  apparatus  called  a  "sparger,"  until  the  wor^ 
which  flows  away,  ceases  to  possess  any  appreciable  gravity  beyond  that  of  water.   The 
worts  are  then  mixed  together,  in  these  cases,  where  table  beer  is  not  made,  and  the 
whole  reduced,  by  boiling,  to  the  desired  gravity  of  the  beer  meant  to  be  brewed. 
"Where  table  beer,  however,  is  manufacture^  the  strong  worts  are  kept  apart  and  the 
weak  ones  alone  are  fermented  for  this  purpose.     In  both  cases,  the  strong  beers  are 
brewed  from  worts  having  a  technical  weight  of  from  20  to  36  lbs.  per  barrel.    It  has 
long  been  supposed,  that  wort,  as  usually  manufactured,  consisted  chiefly  of  su^ar,  but 
this  is  a  great  error,  for  there  is  seldom  so  much  as  one-third  of  all  the  extract  in  wort 
saccharified-     The  ordinary  proportion  is,  one  part  of  grape-sugar  and  three  of  dextrine. 
MALT  KILN  {Darre,  Germ.)    The  improved  malt  kUn  of  Pistorius  is  represented, 
/Ig.  884,  in  a  top  view ;  jig.  885,  in  a  longitudinal  view  and  section ;  and  fig,  886,  in 
transverse  section,    a  a  are  two  quadrangular  smoke  flues,  constructed  of  fire-tiles,  or 
fire-stones,  and  covered  with  iron  plates,  over  which  a  pent-house  roof  is  laid ;   the 
whole  bound  by  the  cross-pieces  6  {figs.  885,  886.)    These  flues  are  built  above  a  grating 
c  c,  which  commences  at  c' ;  in  front  of  c'  there  is  a  bridge  of  bricks.     Instead  of  such  a 
brick    flue   covered  with    plates,   iron    pipes  may  be  used,   covered  with  semi-c/lin- 
irical  tiles,  to  prevent  the  malt  that  may  happen  to  fall  from  being  burned,     d  d  are 
the  breast  walls  of  the  kiln,  3  feet  high,  furnished  with  two  apertures  shut  with  iron 


MANGANESE.  105 

dooi-8,  through  which  the  malt  that  drops  down  may  be  removed  from  time  to  time. 

CIS  a  beam  of  wood  lymg  on  the  breast  wall,  against  which  the  hurdles  are  laid  down 

slantingly  towards  the  back  wall  of  the  kiln;  //are  two  vertical  flues  left  in  the 

substance  ot  the  walls,  through  which  the  hot  air,  discharged  by  open  pipes  laid  in  a 

subjacent  furnace,  rises  into  the  space  between  the  pent-house  roof  and  the  iron  plates, 

and  IS  thence  allowed  to  issue  through  apertures  in  the  sides,     g  is  the  discharge  flue  in 

the  back  wall  of  the  kiln  lor  the  air  now  saturated  with  moisture;  h  is  the  smoke-pipe, 

from  which  the  smoke  passes  into  the  anterior  flue  a,  provided  with  a  slide-plate,  fo^ 

modifym^  the  draught;    the  smoke  thence  flows  off"  through  a  flue  fitted  also  with  a 

damper-plate  into  the  chunney  i      k  is  the  smoke-pipe  of  a  subsidiary  fire,  in  case  no 

smoke  should  pass  through  h.     The  iron  pipes  are  1 1  inches  in  diameter,  the  kir-flues/,  5 

inches,  and  the  smoke-pipe  h,  10  inches  square ;  the  brick  flues  10  inches  wide,  and  the 

usual  height  of  bricks. 

r»,i^«ti;T"r^  'vf  ^"  n'  G/tt/.W,  or  mineral  pitch.  It  is  a  soft  glutinous  substance,  with 
the  smell  of  pitch.  It  dissolves  m  alcohol,  but  leaves  a  bituminous  residuum ;  as  also  in 
naptha,  and  oil  of  turpentine.     It  seems  to  be  inspissated  petroleum. 

MANGANESE  (Eng.  and  Fr. ;  Mangan,  Braumteinmetal,  Germ.)  is  a  grayish-white 
metal,  of  a  fine-grained  fracture,  very  hard,  very  brittle,  with  considerable  lustre,  of 
spec.  grav.  8-013,  and  requiring  for  fusion  the  extreme  heat  of  160°  Wedgewood  It 
should  be  kept  in  closely  stoppered  bottles,  under  naptha,  like  potassium,  because  with 
contact  of  air  it  speedily  gets  oxydized,  and  falls  into  powder.  It  decomposes  water 
slowly  at  common  temperatures,  and  rapidly  at  a  red  heat.  Pure  oxyde  of  manganese 
can  be  reduced  to  the  metallic  state  only  in  small  quantities,  by  mixing  it  with  lamp 
black  and  oil  into  a  dough,  and  exposing  the  mixture  to  the  intense  heat  of  a  smith's 
forge,  m  a  luted  crucible;  which  must  be  shaken  occasionally  to  favor  the  ag- 
glomeration of  the  particles  into  a  button.  Thus  procured,  it  contains,  however,  a  little 
carbon.  ' 

Manganese  is  susceptible  of  five  degrees  of  oxvgenation. 

1.  The  protoxydemay  he  obtained  from  a  solution  of  the  sulphate  by  precipitation  with 
carbonate  of  potash,  and  expelling  the  carbonic  acid  from  the  washed  and  dried  car- 
bonate, by  calcination  in  a  close  vessel  filled  with  hydrogen  gas,  taking  care  that  no 
air  have  access  during  the  cooling.  It  is  a  pale  green  powder,  which  slowly  attracts 
oxygen  frorn  the  air,  and  becomes  brown ;  on  which  account  it  should  be  kept  in  glass 
tubes,  containing  hydrogen,  and  hermetically  sealed.  It  consists  of  77-57  metal  and  22-43 
oxygen.  It  forms  with  24  per  cent,  of  water  a  white  hydrate ;  and  with  acids,  saline 
compounds ;  which  are  white,  pmk  or  amethyst  colored.  They  have  a  bitter,  acerb  taste, 
and  afford  with  hydrogenated  sulphuret  of  ammonia  a  flesh-red  precipitate,  but  with 
caustic  alkalis,  one  which  soon  turns  brown-red,  and  eventually  black. 

2.  The  deutoxyde  of  manganese  exists  native  in  the  mineral  caUed  Braunite:  but  it  may 
be  procured  either  by  calcining,  at  a  red  heat,  the  proto-nitrate,  or  by  spontaneous  oxydize- 
ment  of  the  protoxyde  m  the  air.  It  is  black ;  when  finely  pulverized,  dark  brown,  and 
is  convertible,  on  being  heated  m  acids,  into  protoxyde,  with  disengagement  of  oxygen  eas 
It  consists  of  69-75  metal,  and  30-25  oxygen.  It  forms,  with  10  per  ?ent.  of  wa?er,l  U^^rl 
brown  hydrate,  which  occurs  native  under  the  name  of  Manganite.  It  dissolves  readilv 
in  tartaric  and  citric  acids,  but  in  few  others.  This  oxyde  constitutes  a  bronze  ground  in 
calico-printing.  ^  "* 

3.  Peroxyde  of  manganese;  Braunstein,  occurs  abundantly  in  nature.  It  gives  out 
oxygen  freely  when  heated,  and  becomes  an  oxydulated  deutoxyde.  It  consists  of  63-3fl 
metal,  and  36-64  oxygen. 

4.  Manganeiic  acid  forms  green-colored  salts,  but  has  not  hitherto  been  insulated  from 
the  bases.    It  consists  of  53-55  metal,  and  46-45  oxygen. 

5.  Hypermanganesic  acid  consists  of  49-70  metal,  and  50-30  oxygen. 

Ores  of  manganese.— There  are  two  principal  ores  of  this  metal  which  occur  in  great 
masses ;  the  peroxyde  and  the  hydrated  oxyde ;  the  first  of  which  is  frequently  found  in 
primitive  formations. 

1.  Metalloide  oxyde  of  manganese ;  pyrolusite,  or  gray  manganese  ore :  has  a  metallic 
lustre,  a  steel  gray  color,  and  affords  a  black  powder.  Spec.  grav.  4-85.  Scratches  calc- 
spar.  It  eff^ervesces  briskly  with  borax  at  the  blow-pipe,  in  consequence  of  the  disencac'e- 
ment  of  oxygen  gas.  This  is  the  most  common  ore  of  manganese,  and  a  very  valuable 
one,  being  the  substance  mostly  employed  in  the  manufacture  of  chloride  of  lime  and  of 
flmt-glass.  It  is  the  peroxyde.  Great  quantities  are  found  near  Tavistock,  in  Devon- 
shire, and  Launceston,  in  Cornwall. 

2.  Bmunite,  is  a  dark  brown  substance,  of  a  glassy  metallic  lustre,  affording  a  brown 
powder.  Spec,  grav  4-8.  It  scratches  feldspar ;  but  is  scratched  by  quartz.  Infusible 
at  the  blow-pipe,  and  effervesces  but  slightly  when  fused  with  glass  of  borax  It  is  the 
deutoxyde.     It  gives  out  at  a  red  heat  only  3  per  cent,  of  oxygen. 

3.  ManganUe,  or  hydroxyde  of  manganese  j  is  brownish-black  or  iron-black,  powder 


106 


MANGANESE. 


:i 


mi 


f^   1 


'I? 


su^^huy^whenrused  with  ^^s  ^c:ti/:^^zsz72:^'::t^ 

vesce  wl^n  fSwi.l'borS      I  fsTdeuZld'e"'^' t  •.  • '  ""'  ""^"'''P'' '  ""^  ""'  '^"- 
to  the  arts.  ""  ""ra^-     "  is  a  deutoxyde.    ThiS  is  a  rare  mineral,  and  of  no  value 

peLfd^iuhlf  el^^r""'  ^^""'  ""''•    "  ''  «  ■»»«»'"»"  "f  -l^'oMe  and 
dark  sSTv"  W^"vt'95"t  "^  "T""'''  '  ""^  »  "«■"""  "'^^  '  "  "-><,  or 

aide  o7potassiun,      K  ".iSLr^f  s^^pfc-S^^^'^V^^resTeTsr''  """  '"'  '■""«^''- 

flnn'r     t'P^r"!;  ^^T^''^'.  o/r«anga»«,«  is  brown  or  black.     Spec  grav  3  6     scratches 
nuor;    affords  by  calcination  a  I'prv  liftlp  nf  on   »«m        *         "i;^^.  &i«v.  o  o  ,  scraicnes 

oec^utl^alirtitl^^^^^^^^^  P-^'^e  of  manganese.    It 

massive.      Some  varietirposserCe^?ect^^^^^^^  The'el'^t'  ^'  '''''' 

Sr^^^r^^iS^-bf  i^;  I-  ES^  M  ^J^p^^: 

generally  they  contained  no  les    thTn  2^%rr/  of^  «  o  '5'  r'^;"*    I"'^ 

'  t'Sa^'T^"'  the  remainder  amountingTo^'ly^o';^/^^^^^^^^^^   'p^/oxySe  "^'''  '^'^^^ 

places  the  manganese  powder  in  a  smSl^'e^rrt^Tr  S"u.^re^^^^^^^^^^  thl 

LinTn^mflk^nf  r °^"^'^  T'l;  *^^  ^'^  «^  ^  ?^^^1«  h^^*' '«  Lnsmitted  into  a^lel  co„' 

8^  u  ifn  nf  ^ll  \^°^^,?^  P«t««h  water.     This  liquor  is  afterwards  poured  into  a  dilute 

orTfuuifFr      «^^?f?«i.«^°^,  the  quantity  of  chlorine  is  inferred  from  the  quaS 

The  ^^n,!?i".    ""  "^Vfl  •  '!  ^r^^^^'^-     I  P^s  the  chlorine  into  test  solution  of  inSig^ 

The  manufacturer  of  flint  glass  uses  a  small  proportion  of  the  black  manganese  of  ^ 

s'^n^d reltl^'r  To'l!^^^^^^^^^        ^'T  ""  ^p'  *'^--  ^--  the^L";rern?Lre 
tainir.^  I^PA?  •  -^^  *  ^^  of  great  consequence  to  get  a  native  manganese  con- 

duTwill  il     r^'u  """"i"  ^'  P^''^^^^'  «^°««  ^^^^«t  the  color  or  limpidity^of  hTs  prS- 
duct  will  depend  altogether  upon  that  circumstance.  ^     ^  ^ 

,.  X.^^'i^'t^       u^"^^''^.^^  has  been  of  late  years  introduced  into  calico  printing  to^iva 

^^Tl'^lt  ^V^rr'"  impression.     It  is  easily  formed  by  heatinrth"  b  afk  old? 

ThP  Ir    ^}'^^\^  ^^"^^  "°*^'  ^^*^  sulphuric  acid.     See  Calico  pf int^o      ^  '''"^^• 

The  peroxide  of  manganese  is  used  also  in   the    formation  of  glJs  pastes  and  in 

malting  the  black  enamel  of  pottery.     See  Oxalic  Acid.  ^        ^    ^''  *'''*  "* 

The  recovery  of  manganese  in  the  state  of  peroxide  for  the  chemical  arts  in  whioh 

It  IB  80  extensively  consumed,  has  been  long  a  desideratum  in  manufactured' 

r.^-,     f   IT^  pretends  to  reconvert  the  Residuum  that  is  left  after  the  disenea^e- 

nTviiutfnlnUst:?rof^^^^  ^z:  4^-''^^^'^'^' 

which  is  pecuHarly  fitted,  by  ?he  large  ^pr^^o^^ti    'f^oxy^nT^^^^^^^^^ 


MANGANESE. 


lOT 


the  purpose  of  affording  either  chlorine  or  oxygen  gas  again,  according  to  the  process 
It  18  subsequently  subjected  to.  The  said  residuary  matters,  after  the  extrication  of 
the  chlorine  in  the  manufacture  of  chloride  of  lime,  or  bleaching  powder,  and  of  chlo- 
rate or  hyperoxymuriate  of  potasli,  consist  principally  of  chloride  and  sulphate  of 
manganese ;  but  as  these  residuums  may  and  have  been  occasionally  converted  more 
or  less  into  sulphuret  of  manganese  when  they  are  used  to  purify  coal  gas  from  its 
sulphur  or  su  phuretted  hydrogen,  the  patentee  includes  not  only  the  above  sulphate 
and  chloride,  but  also  the  sulphuret  of  manganese,  among  the  waste  or  refuse  products, 
which  he  converts  into  a  valuable  peroxide  of  that  metal.  He  applies,  moreover,  this 
invention  to  the  conversion  of  all  oxides,  carbonates,  and  other  combinations  of  man- 
ganese whatever,  whether  native  or  factitious,  which  contain  the  metal  in  an  inferior 
state  of  oxidation,  into  a  superoxide  of  manganese,  adapted  to  produce  chlorine  by 
the  agency  of  hydrochloric  acid,  and  oxygen  by  the  agency  either  of  heat  alone,  or  of 
neat  along  with  sulphuric  acid. 

The  manner  in  which  the  said  invention  is  to  be  carried  into  execution  is  as  follows  • 
The  conversion  of  manganese,  whether  combined  or  uncombined  from  a  lower  state 
of  oxidation  into  the  higher  state  of  superoxide,  is  effected  by  two  distinct  operations 
i^irst,  It  is  well  known  that  wh«n  peroxide  of  manganese,  called  in  its  purest  native 
state,  pyrolu?ite,  and  also  gray  manganese  ore,  is  digested  with  hydrochloric  or  mu- 
riatic acid,  the  oxygen  of  the  metal  combines  with  the  hydrogen  of  the  acid  to  form 
water,  and  leave  the  chlorine  of  the  acid  free,  while  the  manganese,  thus  partially 
stripped  of  its  oxygen,  combines  with  the  rest  of  the  hydrochloric  acid  to  form  a  mu- 
riate of  manganese.     Likewise,  when  more  or  less  dilute  sulphuric  acid,  common  salt 
(chloride  of  sodiumX  and  peroxide  of  manganese,  are  so  mixed  and  treated  as  to  be 
made  to  react  on  one  another  the  hydrochloric  acid,  which  is  disengaged,  is  converted 
by  the  oxygen  of  the  manganese  into  water  and  chlorine,  while  both  the  soda  pro- 
duced from  the  common  salt,  and  the  partially  deoxidized  manganese,  combine  with 
the  sulphuric  acid  into  sulphate  of  soda  and  sulphate  of  manganese.     He  converts 
either  the  chloride,  sulphate,  sulphuret,  or  carbonate,  into  a  sesquioxide  or  deutoxide 
of  manganese,  by  one  or  other  of  the  three  following  processes :— First,  he  subjecte 
dried  chloride  of  manganese  to  a  strong  heat,  produced  either  by  the  united  action  of 
burning  fuel^  and  a  jet  or  jets  of  an  oxy-hydrogen  blowpipe,  or  of  a  stream  of  atmos- 
pheric air  thrown  upon  the  burning  fuel  by  a  fan  or  other  suitable  impulsive  power 
thus  forming  a  kind  of  blowpipe  or  blast-furnace,  in  which  the  chemical  decomposi- 
tion and  reaction  are  rendered  quicker  and  more  complete.     The  furnace  is  constructed 
like  an  ordinary  reverberatory  furnace,  with  the  addition  of  a  box  or  chest  of  iron 
open  at  top,  set  m  the  fire-place,  close  to  the  bridge,  which  box  is  filled  with  iron 
turnings,  borings,  or  other  small  fragments  of  iron,  upon  which,  in  their  strongly  ig- 
nited state,  water  is  allowed  to  trickle  or  drop  down  slowly  from  a  pipe,  so  as  as  to 
be  deconjposed,  and  to  disengage  a  stream  of  hydrogen,  which  is  impelled  over  the 
bridge  of  the  furnace  upon  the  hearth  by  means  of  a  fan  or  other  blowing  machine 
acting  at  the  entrance  or  door  of  the  fire-place.     The  manner  in  which  the  furnace  is 
regulated  18  as  follows:— The  fuel,  either  common  coals,  coke,  anthracite,  wood,  turf 
Ac    is  first  lighted  upon  the  grate,  and  being  subjected  to  the  blast  of  air,  soon  creates 
such  a  temperature  as  to  raise  the  box  of  iron  turnings  to  a  red-white  heat,  in  which 
state  the  water  being  allowed  to  trickle  down  into  the  said  box,  is  decomposed  with 
the  copious  disengagement  of  hydrogen  gas.     The  chloride  of  manganese  may  be  ex- 
posed on  the  hearth  of  the  reverberatory  furaace  either  in  a  more  of  less  concentrated 
liquid  state,  or  in  a  dry  state,  to  the  action  of  the  intensely  powerful  flame,  generated 
as  above  described,  and  becomes  thereby  decomposed  by  the  hydrogen,  with  the  dis 
engagement  of  its  chlorine  in  the  state  of  hydrochloric  acid  or  muriatic  acid  gas  whUe 
^.nf!;^T'''"r?uPi''*5''''^?  "*?  manganese  becomes  at  the  same  time  oxidized  into  the 
deutoxide.     The  hydroclonc  acid  gas  disengaged  is  condensed  by  means  of  vaults 
or  large  chimneys  coritaming  wet  coke  or  flint  nodules  in  the  w^y  often  practised 
m  soda  manufactories.     Instead  of  the  above-described  hydrogen  flame,  heUploys 
sometimes  a  simple  reverberatory  furnace  with  ordinary  fuel,  lither  with  or  without 
blast,  m  which  he  resolves  the  chloride  of  manganese  into  hydrochloric  acid  and  per- 
oxide of  manganese,  but  he  prefers  the  compound  flame  of  hydrogen  and  ordinary  fuel 
In  his  second  process^  instead  of  acting  on  chloride  of  mangfnese  by  the  flame  of 
combustible  matter  on  the  hearth  of  a  furnace,  he  subjects  the  chloride  ymanga^Le 
pu    into  f-%«lay  retorts,  to  an  intense  heat,  by  which  he  expels  the  chlorine ^Zuy 
in  the  state  of  hydrochloric  acid,  and  partly  of  chlorine,  and  the  manganese  left  in  th{ 
retoits  ma^  be  afterwards  peroxidized  by  l  process  to  be  presentiriescXd 

In  his  third  process  he  mixes  together  chloride  of  manganese  anl  carbonate  of  lime, 
suhr?.  tW  Z^uir,7:^  equivalent  proportions  for  mutual  decomposition,  and  h^ 
subjects  that  mixture  to  the  strong  heat  of  the  above-described  compound  hVdrogeu 
flame,  whereby  he  obtains  a  mixture  of  chloride  of  calcium  (muriate  of  lime),  and  o:2de 


fit 


108 


MANGANESE. 


ill! 


|i'<i,  5 


i»;  J 


of  manganese,  which  he  peroxidizea  by  a  process  about  to  be  described  Magnesia,  or 
magnesian  hmestone,  may  be  substituted  for  lime,  or  its  carbonate,  in  this  process. 
When  the  carbonate  of  hme  is  used  with  rather  too  low  a  heat  in  the  furnace,  carbon- 
ate of  manganese  may  be  formed.  In  all  cases,  the  resulting  mixture  of  chloride  of 
calcium  or  magnesium,  and  oxide  of  manganese  is  to  be  treated  with  water,  so  as  to 
dissolve  out  the  said  chlorides,  and  leave  the  oxide  of  manganese. 

The  following  is  the  plan  of  decomposing  sulphate  of  manganese,  however  formed  so 
as  to  obtain  from  it  an  oxide  of  manganese,  to  be  peroxidized  by  an  after  process:— 

He  mixes  the  sulphate  of  manganese  with  sawdust,  ground  coke  or  charcoal  or  any 
like  combustible  matter,  only  in  such  proportion  as  to  be  capable  of  decomposing  the 
sulphuric  acid  present,  when  the  mixture  is  subjected  to  a  strong  calcining  heat  in  re- 
torts of  iron,  or  preferably  of  fire-clay,  whereby  he  obtains  a  siilphuret  of  manganese 
mixed  with  more  or  less  oxide  of  manganese.  He  finishes  this  operation  by  introduc- 
ing into  the  said  residuary  mixture,  fragments  of  coke,  charcoal  or  coal,  and  continu- 
ing the  application  of  heat  for  some  time,  while  the  mouth  of  the  retort  is  left  open, 
whereby  he  desulphurates  the  manganese  in  a  greater  or  less  degree,  and  converts  its 
Bulphuret  uito  an  oxide.  In  case  any  salt,  or  other  compound  of  soda,  should  have  been 
DQixed  with  the  sulphate  of  manganese,  the  soda  compound  is  to  be  separated  from 
the  manganese  by  means  of  water,  after  the  above-described  calcination  in  the  retorts. 
Ihe  sul|4iuret  of  manganese  sometimes  produced  in  coal  gas  works,  as  a  residuum  of 
the  purification  of  the  gas,  may  be  desulphurated  in  retorts  as  above  described,  or  pre- 
ferably by  exposing  it  mixed  with  pieces  of  coke,  charcoal,  coal  or  wood,  on  the  hearth 
of  the  above-described  reverberatoiy  hydrogen  furnace.  The  coke,  Ac,  should  be  used 
not  in  powder,  but  in  distinct  pieces,  whereby  it  may  be  readily  separated  from  the 
oxide  of  manganese  afterwards,  either  by  a  sieve  or  other  suitable  means. 

The  following  is  his  manner  of  performing  the  second  operation,  or  series  of  opersr 
tions  whereby  he  converts  the  deutoxide  of  manganese  produced  in  tlie  before-des- 
cribed processes,  as  also  all  lower  oxides  and  the  carbonated  oxide  of  manganese,  whe- 
ther natural  or  factitious,  into  a  superoxide  fit  for  affording  chlorine  by  the  action  of 
hydrochloric  acid,  and  oxygen  by  heat;  and  he  produces  the  said  peroxidizement  in 
one  or  other  of  the  three  following  ways.     First,  he  converts  the  said  oxides  or  carbon- 
ates from  their  lower  to  the  much  higher  state  of  oxidation  of  an  acid  of  manganese, 
by  subjecting  a  mixture  of  them  with  alkaline  matters,  such  as  potash  or  soda,  either 
caustic  or  carbonated,  on  the  hearth  of  a  reverberatory  furnace,  to  the  joint  agency  of 
heat  and  atmospherieal  oxygen,  which  may  or  may  not  be  impelled  and  diffused  by 
mechanical  means.     He  finds  that  about  one  part  of  the  oxide  or  carbonate  of  man- 
ganese, mixed  with  about  three  parts  of  alkaline  matter,  forms  a  suitable  proportion 
for  the  production  of  an  acid  of  manganese.    The  said  mixture  fuses  with  the  produc- 
tion  of  a  manganate  or  permanganate  of  potash  or  soda,  according  as  one  or  other  al- 
kali has  been  used  in  the  mixture.     The  fused  mass  is  run  or  laded  out  of  the  furnace, 
and  when  cooled  is  dissolved  in  hot  water.    Tliis  solution,  of  what  is  sometimes  called 
chameleon  mineral,  on  being  exposed  freely  to  the  air,  becomes  decomposed,  by  the 
absorption  of  carbonic  acid  gas,  into  peroxide  of  manganese,  which  precipitates  in  a 
black  powder,  and  carbonated  alkali  which  remains  in  solution.     Where  carbonic 
acid  can  be  conveniently  procured  at  a  very  cheap  rate,  the  above  described  decom- 
position of  the  chameleon  mineral  m'ay  be  promoted  by  a  due  application  of  the  said 
acid  gas.     Or,  otherwise,  the  alkaline  bicarbonates  obtained  from  a  preceding  decom- 
position of  chameleon  mineral  may  be  employed  for  decomposing  a  fresh  made  solution 
of  the  said  chameleon,  whereby  a  precipitate  of  peroxide  of  manganese  is  immedi- 
ately obtained.     The  supernatant  alkaline  liquor  is  in  all  cases  decanted  or  run  off, 
and  reserved  for  subsequent  use.    He  also  decomposes  chameleon  mineral  with  the 
production  of  peroxide  of  manganese  by  the  action  of  various  organic  products,  such 
as  starchy  or  gummy  matters,  but  he  greatly  prefers  to  effect  the  desired  produc- 
tion of  peroxide  of  manganese  by  carbonic  acid  gas,  or   ari  alkaline  bicarbonate. 
His  second  method  of  producing  peroxide  of  manganese  from  its  lower  oxide  or  car 
bonate,  consists  in  subjecting  a  mixture  of  about  one  equivalent  chemical  proportion 
of  either  of  these,  and  about  one  equivalent  of  lime,  to  the  chlorine  expefled  by 
heat  from  chloride  of  manganese,  contained  in  the  retort,  as  heretofore  described 
Or,  by  treating  one  equivalent  proportion  of  that  lower  oxide  of  manganese,  called 
by  chemists  sesquioxide  or  deutoxide,  with  one-half  of  an  equivalent  proportion  of 
aqueous  or  liquid  hydrochloric  acid,  he  obtains  simultaneously  one-half  of  an  equiva- 
lent proportion  of  protochloride  of  manganese  in  solution,  and  one-half  an  equivalent 
of  peroxide  in  the  state  of  a  black  powder.     A  like  reaction,  with  the  production  of 
a  solution  of  protochloride  of  manganese,  and  black  peroxide,  may  be  effected  by 
treating  the  said  sesquioxide  with  aqueous  hydrochloric  acid  in  one  vessel,  and  trans- 
mitting therefrom  the  chlorine  disengaged  into  another  vessel,  containing  a  like  Be»> 
quioxide  in  a  moist  state. 


MANFACTURING  INDUSTRY. 


109 


The  third  method  of  converting  into  peroxide  of  manganese  its  lower  oxide  or  car- 
bonate consists  in  directing  over  the  surface  of  either  of  these,  in  a  moist  state,  the 
deutoxide  of  azote,  frequently  called  nitrous  gas,  which  is  obtained  as  a  waste  product 
m  certain  chemical  operations,  as  in  the  manufacture  of  oxalic  acid,  or  nitrate  of  lead, 
or  of  copper,  <fec.  ^ 

In  this  case,  the  nitrous  gas  becomes  reduced  to  a  lower  state  of  oxidation,  and  by 
^^^IZn^A^S^t^  ***  *^®  ^^^^^  ^^^^^  of  manganese,  converts  it  into  peroxide 

MAWCrANhhE,  OXIDE  OF;  for  a  simple  method  of  ascertaining  the  value  of  this 
substance  m  the  production  of  chlorine,  and  the  manufacture  of  the  chlorides  and 
chlorates,  see  Chemistry  Simplified. 

lAAmLE,  (Calandre,  Fr. ;  Manffel,  Germ.)  This  is  a  well  known  machine  for 
smoothing  table  cloths,  table  napkins,  as  well  as  linen  and  cotton  furniture.  As 
usually  made,  it  consists  of  an  oblong  rectangular  wooden  chest,  filled  with  stones, 
which  load  It  to  a  degree  of  pressure  that  it  should  exercise  upon  the  two  cylinders 
on  which  It  rests,  and  which,  by  rolling  backwards  and  forwards  over  the  linen  spread 
upon  a  polished  table  underneath,  render  it  smooth  and  level  The  moving  wheel 
being  furnished  with  teeth  upon  both  surfaces  of  its  periphery,  and  having  a  notch  cut 
out  at  one  part,  allows  a  pinion,  uniformly  driven  in  one  direction,  to  act  alternately 
upon  Its  outside  and  inside,  so  as  to  cause  the  reciprocating  motion  of  the  chest  This 
elegant  and  much  admired  English  invention,  called  the  mangle-wheel,  has  been  in- 
troduced  with  great  advantage  into  the  machinery  of  the  textile  manufactures. 

Mr.  Warciip,  of  Dartford,  obtained  a  patent  several  years  ago  for  a  mangle,  in  which 
the  linen  being  rolled  round  a  cylinder  revolving  in  stationary  bearing  is  pressed 
downwards  by  heavy  weights  hung  upon  its  axes,  against  a  curved  bed,  made  to  slide 
to  and  fro  or  traverse  from  right  to  left,  and  left  to  right  alternately. 

Mr.  Iluhie,  of  York,  patented  in  June,  1832,  another  form  of  mangle,  consisting  of 
three  rollers  placed  one  above  another  in  a  vertical  frame,  the  axle  of  the  upper  roller 
being  pressed  downwards  by  a  powerful  spring.  The  articles  intended  to  be  smoothed 
are  introduced  into  the  machine  by  passing  them  under  the  middle  rolller,  which  is 
made  to  revolve  by  means  of  flv  wheel ;  the  pinion  upon  whose  axis  works  in  a  large 
toothed  wheel  nxed  to  the  shaft  of  the  same  roller.  The  linen,  <kc.  is  lapped  as  usual 
in  protecting  cloths.     This  machine  is  merely  a  small  Calexder. 

MAM  FOLD  BELI.PULL.  {Exhibition.)  45  Bryden  and  Sons,  Hose  Street,  Bdin- 
buryh.  Inventors  and  Manufcu^turers.— A  manifold  bell-pull  constructed  upon  an  en- 
tirely  new  plan  by  which  one  pull  is  made  to  ring  bells  in  any  number  of  rooms. 
When  the  pointer  is  placed  opposite  to  any  name  on  the  dial  plate,  and  knob  pulled 
out,  the  bell  is  then  rung  in  the  room  indicated. 

An  improved  circular  telegraph  bell  having  two  dials,  numbered  in  the  same  man- 
ner, by^  means  of  which  eight  different  clerks  or  workmen  may  be  called 

An  air  signal  mouth  piece  and  bell,  by  blowing  into  the  mouth-piece  the  bell  is  rune, 
at  any  distance  less  than  1,000  feet  This  is  au  improved  method  of  rinmne  a  bell  in 
places  too  distant  or  not  suited  for  working  cranks  and  wires 

A  single  voice  tube  mouth-piece  and  bell-pull.  When  drawn  out  the  tube  orifice  is 
opened,  and  the  signal  bell  being  rung,  the  attendant  is  called  to  the  other  end  of  the 

A  revolving  mouth-piece  for  voice  tubes,  with  bell-pull  combined;  contrived  so 
that  one  mouth-piece  connects  with  six  or  any  greater  number  of  voice  tubes,  and  at 
the  same  time  with  a  similar  number  of  bells. 

Specimen  of  a  self-closing  valve  mouth-piece  for  voice  tube;  and  of  a  spring  covered 
mouth-piece  for  voice  tube.  ^      s        ^  ^^ 

MANIOC,  is  the  Indian  name  of  the  nutritious  matter  of  the  shrub  ja^roMa  mani- 
not,  trom  which  cassava  and  tapioca  are  made  in  the  West  Indies. 

MANNA,  is  the  concrete  saccharine  juice  of  the  Fraxinus  ornus,  a  tree  much  culti- 
^c  *  xT^ir^r^?^^*''^  Calabria.     It  is  now  little  used,  and  that  only  in  medicine 

MANUFACTURING  INDUSTRY,  during  the  Last  and  PreseL  Ce>t1v  by  Wm. 
Fairbairn  Esq.  F.  R.  S.,  Member  of  the  Institute  of  France— If  we  take  I  will  not 
say  a  statistical,  but  a  very  cursory  view  of  the  recent  position  of  Manchester  and 
the  surrounding  districts,  and  compare  it  with  what  it  was  at  the  close  of  the  last  and 
the  commencement  of  the  present  century,  we  shall  find  that  at  that  period  the  use- 
fHof  fK  '""^"f  ^'^1  «^*«  ^ere  comparatively  of  little  importance.  We  shall  also  find 
that  the  grafts  of  a  new,  and  above  all  others  an  important  branch  of  manufacturino- 
industry  springing  into  existence.  I  have  no  returns  of  the  state  of  our  manufacturing 
industry  at  that  period,  but  the  writings  of  one  of  our  eariiest  and  most  intelligent 
spinners,  to  whom  this  country  is  indebted  for  many  improvements  in  machinery,  Mr. 
John  Kennedy,  informs  us,  that  the  spinning  of  cotton  yarn  antecedent  to  the  year  1768. 
was  of  an  exceedingly  hmited  description.    That  gentleman  in  his  account  of  the  rm 

/ 


m 


111 


■1  i 


I  ! 


I  i 


I 


i" 


110 


MANUFACTURING  INDUSTRY. 


and  progress  of  the  cotton  trade,  stated  that  the  hand-loom  as  a  machine  remained 
stationary  for  a  great  number  of  years  without  any  attempt  at  improvement  until  1750, 
when  Mr.  John  Kay,  of  Bolton,  first  introduced  the  fly-shuttle,  and  that  the  spinning 
of  cotton  yarn  from  that  period,  and  for  many  years  previous,  was  almost  entirely 
performed  by  the  family  of  the  manufacturer  at  his  own  house.  This  united  and  simple 
process  went  on  till  it  was  found  necessary  to  divide  their  labors,  and  to  separate  the 
weaving  from  the  spinning,  and  that  agam  from  the  carding  and  other  preparatory 
processes.     This  division  of  labor  as  Mr." Kennedy  truly  says,  led  to  improvements  in 
the  carding  and  spinning,  *'by  first  introducing  simple  improvements  in  the  hand  instru- 
ments, with  which  they  performed  these  operations,  till  at  length  they  arrived  at  a  ma- 
chine, which,  though  rude  and  ill-constructed,  enabled  them  considerably  to  increase 
their  produce."  Thus  it  was  that  improvements,  and  the  division  of  labor,  first  led  to 
the  factory  system,  and  that  splendid  and  extensive  process  which  at  the  present  mo- 
ment and  for  many  years  to  come  will  affect  the  destinies  of  nations.     From  1760  to 
1770,  when  Mr.  Hargreaves,  of  Blackburn,  first  introduced  his  spinning  jenny,  (by 
means  of  which  a  young  person  could  work  from  ten  to  twenty  spindles  instead  of 
one),  there  was  little  or  no  change,  but  a  very  material  alteration  took  place  shortly 
after  the  introduction  of  these  improvements,  which  were  immediately  followed  by  Mr. 
Arkwright's  machinery  for  carding  and  roving.    These  accompanied  by  the  introduc- 
tion of  Mr.  Crompton's  mule,  in  1780,  may  be  justly  considered  to  constitute  the  origin 
of  the  factory  system,  which  has  now  grown  to  such  colossal  dimensions,  as  to  render 
it  one  of  the  most  important  and  most  extensive  systems  of  manufacture  ever  known 
in  the  history  of  ancient  or  modern  times.    Mr.  Arkwright  built  his  first  mill  at  Crom- 
ford  in  Derbyshire  (I  again  quote  from  Mr.  Kennedy)  "  in  1771.  It  was  driven  by  water, 
but  it  was  not  till  1790,  or  sometime  after,  when'the  steam  engine  of  Watt  came  into 
use,  that  the  cotton  trade  advanced  at  such  an  accelerated  speed,  as  to  render  its  in- 
crease and  present  magnitude  almost  beyond  conception.     This  immense  extension  ia 
not  only  a  subject  of  deep  interest  to  the  philosopher  and  statesman,  but  one  which  is 
likely  to  furnish  a  large  field  of  observation  for  the  future  historian  of  his  country." 
I  will  not  trouble  you  with  the  statistics  of  the  cotton  trade  as  it  now  exists,  but 
simply  observe,  as  many  of  you  are  doubtless  better  informed  on  this  subject  than  my- 
self, that  I  am  within  the  mark,  when  I  state  that  no  less  than  31,500  bales  of  cotton 
are  consumed  weekly,  in  the  two  kingdoms,  England  and  Scotland;  that   nearly 
21,000,000  spindles  are  almost  constantly  in  motion,  spinning  upwards  of  105,000,000 
hanks,  or  50,000,000  miles  of  yarn  per  day — in  length  sufficient  to  circumscribe  the  globe 
2,000  times.     Out  of  this  immense  production  about  131,000,000  pounds  of  yarn  are 
exported ;  the  remainder  is  converted  into  cloth,  lace  and  other  textile  fabrics.    This 
marvellous  increase,  this  immense  extent  of  production  could  not  be  effected  without 
considerable  changes  in  the  prospects  of  the  moral  as  well  as  the  physical  condition 
of  society.     It  has  entirely  changed  the  position  of  the  resident  population  of  the  dis- 
trict ;  and  the  secluded  valleys,  farm-houses  and  cottages,  the  beauties  of  a  Lanca- 
shire landscape  of  the  last  generation,  are  rapidly  giving  way  to  the  conversion  of 
villages  into  populous  towns,  with  innumerable  erections  which  resound  with  the 
busy  hum  of  the  spindle  and  the  shuttle.     Along  with  these  changes  we  see  a  new 
generation  springing  into  existence,  factories,  steam-engines,  and  tall  chimneys  rising 
in  every  direction,  and  the  noise  and  smoke  which  meet  the  eye  and  the  ear  of  the 
stranger  at  every  step  give  evidence  of  the  activity  and  prosperity  of  the  industrious 
hive,  which  at  some  future  time  in  English  history  will  announce  to  succeeding  gene- 
rations the  inventions  and  the  discoveries  of  the  nineteenth  century. 

In  this  attempt  to  place  before  you  a  short  account  of  the  use  and  progress  of  our 
national  industry,  I  must  not  forget  that  yarn,  however  finely  or  dexterously  spun  is 
not  cloth ;  and  here  we  enter  upon  another,  and  equally  ingenious  process.  The  yam 
must  be  woven  before  it  is  fit  for  use,  and  we  shall  be  weaving  one  of  the  most  interest- 
ing as  well  as  elaborate  operations  of  the  useful  arts.  I  need  not  inform  you  that  the 
ancient  Hindoos,  Egyptians,  and  probably  the  early  Chinese  converted  their  yarn  into 
cloth.  The  Indian  and  Oriental  department  of  the  Great  Exhibition  exhibited  the  mode 
and  primitive  character  of  their  looms  and  other  implements,  which  have  been  handed 
down  from  generation  to  generation  from  the  earliest  periods,  without  change  or  im- 
provement to  the  present  day.  Looms  of  this  rude  construction  were  introduced  into 
Europe  during  the  first  glimpses  of  civilization,  and  for  many  centuries  even  the  most 
advanced  nations  were  content  to  use  the  same  instruments,  almost  without  improve- 
ment, until  the  introduction  of  the  flying  shuttle  and  the  subsequent  invention  of  Hall 
and  Arkwright  opened  a  new  and  untrodden  field  for  improvements  in  every  depart- 
ment of  art  and  manufacture.  Power  looms  at  that  period  were  unknown,  and  although 
attempts  were  made  by  Mr.  Cartwright,  as  early  as  1774,  to  convert  the  hand  loom 
into  a  machine  to  be  moved  by  power,  it  was  not  until  the  beginning  of  the  present  cen- 
tury that  the  power-loom  assumed  its  present  form,  and  presented  that  intelligence  of 


MANURE. 


Ill 


structure  which  rendered  it  self-acting,  and  enabled  it  to  compete  with  the  hand-loom 
weaver.  From  that  time  (about  1810  or  1812^  we  may  date  the  commencement  of 
that  increase  to  which  that  important  branch  of  our  manufacture  was  extended.  The 
improvements  introduced  by  Mr.  Bennet  Woodcroft  and  other  for  weaving  twills  and 
similar  fabrics  created  new  expedients  and  applications,  and  greatly  increased  the  de- 
mand of  this  description  of  manufactures,  whilst  the  inventions  of  Jacquard  for  weav- 
ing figured  cloth  startled  every  one  with  their  extreme  ingenuity  and  beauty,  and  accom- 
plished the  perfection  of  machinery  for  the  production  of  textile  fabrics.  The  increase 
and  extent  of  cloth  manufactured  from  power-looms  may  be  estimated  from  official 
returns,  kindly  furnished  by  Mr.  Leonard  Horner.  There  are  now  at  work  in  the 
United  Kingdom  above  250,000  power-looms.  Now  as  each  loom  will  upon  the  aver- 
age form  five  to  six  pieces  of  cloth  per  week,  each  piece  28  yards  long,  say  25  yards 
a  day  per  loom,  we  have  250,000,  which  multiplied  by  25  gives  6,250,000  yards,  or 
3,551  English  miles  of  cloth  per  day,  the  distance  between  Liverpool  and  New  York. 
Only  think  of  the  importance  and  extent  of  a  manufacture  that  employs  upwards  of 
12,000  hands  in  weaving  alone,  supplying  from  that  source  (the  power-loom)  an  an- 
nual produce  of  cloth  that  would  extend  over  a  surface  in  a  direct  line  of  upwards  of 
1,000,000  miles. 

But  although  much  has  been  done,  much  has  yet  to  be  accomplished  before  the 
supply  equals  the  demand.  It  must  appear  obvious  to  those  who  have  studied  and 
watched  the  unwearied  invention  and  continued  advancement  which  has  signalized 
the  exertions  of  our  engineering  and  mechanical  industry.  But  neither  difficulties  nor 
danger,  however  formidable,  can  stand  against  the  indomitable  spirit,  skill,  and  per- 
severance of  the  English  engineer ;  nor  will  it  be  denied  that  the  ingenuity  and  never- 
failing  resources  of  our  mechanical  population  are  not  only  the  sinews  of  our  manu- 
factures, railways,  and  steamboats,  but  the  pride  and  glory  of  our  own  country. 

It  is  for  this  important  class,  that  I  have  ventured  to  address  you,  and  I  trust  the 
time  is  not  far  distant,  when  we  shall  witness  establishments  suitable  for  their  educa- 
tion, such  as  will  teach  them  to  reason  and  to  think,  and  to  impart  that  knowledge 
essential  to  a  more  correct  acquaintance  with  physical  truth,  and  a  clearer  conception 
of  the  varied  manipulations  of  those  arts  in  which  consist  the  true  interests  of  the 
country. — Lecture  at  Manchester. 

MANURE.  A  patent  for  an  excellent  article  of  this  kind  was  obtained  in  May, 
1842,  by  J.  B.  Lawes,  Esq.,  for  a  full  description  of  which  the  reader  is  referred  to  the 
articles  Coprolites.  He  decomposes  bones,  apatite,  and  other  subphosphates  of  lime 
by  mixing  them  in  powder  with  as  much  sulphuric  acid  as  will  liberate  enough  of  the 
phosphoric  to  dissolve  the  phosphate  of  lime.  The  free  phosphoric  acid  is  thereby 
ready  to  combine  with  the  various  alkaline  earths  contained  in  the  soil,  while  the 
phosphate  of  lime  is  brought  to  a  state  of  more  minute  division  than  is  possible  by 
mechanical  means.  Mr.  Lawes  also  proposes  to  mix  the  above  soluble  superphosphate 
with  such  alkalis  as  are  deficient  in  the  soil,  and  thus  to  form  a  manure  adapted  to  fer- 
tilize it.  His  third  improvement  in  manure  is  the  formation  and  application  of  a 
liquor  of  flints,  for  such  soils  as  are  deficient  in  soluble  silica.  The  last  compound  he 
considers  to  be  valuable  for  grounds  much  cropped  with  wheat  and  other  cereals  that 
require  a  good  deal  of  silica  for  their  growth. 

It  is  greatly  to  be  regretted,  that  this  most  important  subject  of  scientific  research, 
has  hitherto  been  treated  too  much  in  a  one-sided  manner ;  that  is,  either  by  individuals 
little  conversant  with  practical  farming,  or  by  farmers  little  acquainted  with  the  nature 
of  soils,  and  the  changes  produced  on  them  by  the  cultivation  of  different  orders  of  plants. 
Under  the  auspices  of  the  British  Association,  Professor  Liebig,  in  the  year  1840, 
first  promulgated  his  views  on  agriculture,  from  which  date  we  may  trace  a  spirit  of 
investigation  into  it^  such  as  had  not  previously  existed  in  this  country.  Among 
other  laborers  in  this  field,  we  must  state  that  Mr.  J.  B.  Lawes,  of  Rothamstead,  in 
Hertfordshire,  was  occupied  several  years  prior  to  the  first  edition  of  Professor  Liebig's 
work,  in  investigating  the  action  of  different  chemical  combinations  when  applied  as 
manures,  to  the  most  important  crops  of  the  farm;  and  having  ever  since  continued 
his  experimental  researches  with  all  the  lights  of  science,  with  which  he  is  familiar, 
aided  by  Dr.  J.  H.  Gilbert,  a  skilful  analytical  chemist,  he  has  been  able  to  arrive  at 
conclusions  of  greater  value  and  precision  than  the  merely  theoretical  determinations 
of  the  German  professor.  In  the  course  of  this  inquiry,  the  whole  tenor  of  the  resulU 
of  Messrs.  Lawes  and  Gilbert,  and  also  of  information  derived  from  intelligent  agri- 
cultural friends,  upon  every  variety  of  land  in  Great  Britain,  has  forced  upon  them 
opinions  different  from  those  of  Professor  Liebig,  on  some  important  points;  and  more 
especially,  in  relation  to  his  so-called  "  mineral  theory,"  which  is  embodied  in  the  follow- 
ing sentence  to  be  found  at  page  211.  of  the  third  edition  of  his  work  on  Agricultural 
Chemistry ;  where  he  says  "  the  crops  on  a  field  diminish  or  increase  in  exact  proportion 
to  the  diminution  or  increase  of  the  mineral  substances  conveyed  to  it  in  manure."/ 
Of  the  vast  importance,  both  in  a  scientific  and  a  practical  point  of  view,  of  correct 


I 

II 
I 


I 


M 


; 


tit   ' 


;i  ; 


it)   ; 


11 


112 


MANURE. 


ideas  on  the  subject  here  at  issue,  a  judgment  may  be  formed  from  the  manner  « 
which  the  professor  himself  speaks  of  the  mineral  theory  in  the  new  edition  of  his  let- 
ters  on  chemistry.  Thus  at  page  482.,  he  says  of  the  agrieulturista  of  England  that 
sooner  or  later  thejr  must  see  that  in  the  so-called  mineral  theory  in  its  development 
and  ultimate  perfection  lies  the  whole  future  of  agriculture." 

"Looking  upon  the  subject  in  a  chemical  point  of  view  only,  it  would  seem  that  an 
analysis  of  the  soil  upon  which  crops  were  to  be  experimentally  grown,  as  weU  as  a 
knowledge  of  the  composition  of  the  crop  should  be  the  first  points  ascertained,  with 
the  view  of  deciding  m  what  constituents  the  soil  was  deficient ;  and  at  the  commence- 
ment of  our  more  systematic  course  of  field  experiments,  the  importance  of  these  points 
was  carefully  considered.     When  we  reflect,  however,  that  an  acre  of  soil  six  inches 
deep  may  be  computed  to  weigh  about  1,344,000  lbs.  (though  the  roots  of  plants  take 
a  much  wider  range  than  this),  and  taking  the  one  constituent  of  ammonia  or  nitrogen 
as  an  Illustration,  that  in  adding  to  this  quantity  of  soil  a  quantity  of  amraoniacal  salt, 
containing  100  lbs.  of  ammonia,  which  would  be  an  unusually  heavy  and  very  effective 
dressing,  we  should  only  increase  the  per  centage  of  ammonia  in  the  soil  by  0-0007  it 
18  evident  that  our  methods  of  analysis  would  be  quite  incompetent  to  appreciate  the 
difference  between  the  soil  before  and  after  the  application,— that  is  to  say,  in  its  state 
oi  exhaustion,  and  of  highly  productive  condition,  so  far  as  that  constituent  is  con- 
cerned ;  and  from  our  knowledge  of  the  effects  of  this  substance  on  wheat,  we  may  con- 
ndently  assert  that  the  quantity  of  it  supposed  above  would  have  given  a  produce  at 
least  double  that  of  the  unmanured  land.     The  same  kind  of  argument  might,  indeed 
be  adopted  m  reference  to  the  more  important  of  tliose  constituents  of  a  soil  which 
are  found  m  the  ashes  of  the  plants  grown  upon  it,  and  we  determined,  therefore,  to 
seek  our  results  in  another  manner.     Indeed,  the  imperfection  of  our  knowledge  of  the 
productive  quality  of  a  soil,  as  derived  from  its  per  centage  composition,  has  been  am- 
ply  proved  by  the  results  of  analysis  which  have  been  published  during  the  last  ten 
years;  and  in  corroboration  we  need  only  refer  to  the  opinions  of  Professor  Magurs  on 
this  subject,  who,  in  his  capacity  of  chemist  to  the  '  Landes  Ockonomie  Kollegium'  of 
I'russia,  has  published  the  results  of  many  analyses  of  soils.     The  truth  is,  that  little 
is  as  yet  known  of  what  a  soil  either  is,  or  ought  to  be,  in  a  chemical  point  of  view  • 
but  when  we  call  to  mind  the  investigations  of  Professor  Mulder,  in  relation  to  the 
organic  acids  found  m  soils,  and  of  Mr.  Way  and  others,  as  to  the  chemical  and  phy- 
sical properties  of  soils,  in  relation  to  the  atmosphere,  and  to  saline  substances  exposed 
to  their  action  in  solution,  we  may  at  least  anticipate  for  chemistry  that  she  wifi  ere 
long  throw  important  light  on  this  interesting  but  intricate  subject. 

"In  our  field  experiments,  then,  we  have  been  satisfied  with  preserving  specimens  of 
the  soils  which  were  to  be  the  subjects  of  them,  and  have  sought  to  ascertain  their 
deficiency  m  regard  to  the  production  of  different  crops,  by  means  which  we  conceive 
to  be  not  only  far  more  manageable,  but  in  every  way  more  conclusive  and  satisfac- 
tory in  their  result  To  illustrate,— what  is  termed  a  rotation  of  crops  is  at  least  of 
such  universahty  in  the  farming  of  Great  Britain,  that  any  investigation  in  relation 
to  the  agriculture  of  that  country  may  safely  be  grounded  on  the  supposition  of  its 
adoption.  Let  us,  then,  direct  attention  for  a  moment  to  some  of  the  chief  features  of 
rotations.  What  is  called  a  course  of  rotation  is  the  period  of  years  which  includes 
the  circle  of  all  the  different  crops  grown  in  that  rotation  or  alternation.  The  crops 
which  thus  succeed  each  other,  and  constitute  a  rotation,  may  be  two,  three,  four  or 
more,  varying  with  the  nature  of  the  soil  and  the  judgment  of  the  farmer;  but  what- 
ever course  be  adopted,  no  individual  crop— wheat,  for  example,  is  grown  immediately 
succeeding  one  of  the  same  description,  but  it  is  sown  again  only  after  some  other- 
crops  have  been  grown,  and  at  such  a  period  of  the  rotation,  indeed,  as  by  experience 
it  is  known  that  the  soil  will,  by  direct  manure  or  other  means,  have  recovered  its 
capability  of  producing  a  profitable  quantity  of  the  crop  in  question. 

"  On  carefully  considering  these  established  and  well-known  facts  of  agriculture  it 
appeared  to  us  that,  by  taking  soils  either  at  the  end  of  the  rotation,  or  at  least' at 
that  period  of  it  when  the  ordinary  course  of  farming  farm-yard  manure  would  be 
added  before  any  further  crop  would  be  grown,  we  should  then  have  the  soils  in  what 
may  be  termed  a  normal,  or,  perhaps  better  still,  a  practically  and  agriculturally  ex- 
hausted state.  "  i/  if 

"Now,  if  it  is  found,  in  the  experience  of  the  farmer,  that  land  of  any  given  quality  with 
w;hich  he  is  well  acquainted,  will  not,  when  in  this  condition  of  practical  exhaustion, 
yield  the  quantity  he  usually  obtains  from  it  of  any  particular  crop,  but  that  after  apply- 
ing farm-yard  manure  it  will  do  so,  it  is  evident  that  if  we  supply  to  different  plots  of 
this  exhausted  land  the  constituents  of  farm-yard  manure  both  individually  and  combined, 
and  if  by  the  side  of  these  plots  we  also  grow  the  crop  both  without  manure  of  any 
kind  and  with  farm  yard  manure,  we  shall,  in  the  comparative  results  obtained,  have  a 
far  more  satisfactory  solution  of  the  question  as  to  what  constituents  were,  in  this  ordin- 
ary course  of  agriculture,  most  in  defect  in  respect  to  the  proportion  of  the  particular 


MANURE. 


118 


crop  experinaented  upon  than  any  analysis  of  the  soil  could  have  given  us.  In  other 
words,  we  should  have  before  us  very  ^ood  ground  for  deciding  to  which  of  the  con- 
etituents  of  the  farm-yard  manure  the  increased  produce  was  mainly  due  ou  the  plat 
provided  with  It,  in  the  case  of  the  particular  crops ;  not  so,  however,  unless  the  soil  had 
been  so  far  exhausted  by  previous  cropping  as  to  be  considered  »rac^Jca//y  unfit  for  the 
growth  of  the  crop  without  manure.  W^e  lay  particular  stress  on  this  point,  because  we 
believe  that  the  vast  discrepancy  in  the  results  of  comparative  trials  with  different 
manures,  by  different  experiments,  arise  more  from  irregularity  in  what  may  be  called 
the/oa  tngr  capital  of  the  soil  than  from  irregularities  in  the  original  character  of  the 
Ipplicadon""  ^""^  ''*'^^  '"'^^*'  ^^  '"''^"'^^  *^^  frequent  faulty  methods  of 

Ji  l^  '^  1^°'  ^y  ^^i8  fy"'^^*^'  rather  than  by  the  analytic  method  that  we  have  sought 
our  results ;  and  m  the  carrrying  out  of  our  object  we  have  taken  wheat  as  the  type 
of  the  cereal  crops,  turnips  h»  the  type  of  the  root  crops,   and  beans  as  the  representa- 
«pllf   $  /  ^'^'Z*^^;"*  corn  crop  most  frequently  entering  into  rotation  ;  and  having 
selected  for  each  of  these  a  field  which,  agriculturally  considered,  was  exhausted,  wl 
have  grown  the  same  description  of  crop  upon  the  same  land,  year  after  year,  with  dif- 
ferent chemical  manures,  and  in  each  case  with  one  plot  or  more  continuouslv  unma- 
nured,  and  one  supplied  every  year  with  a  fair   quantity  of  farm-yard  manure.     In 
this  way  14  acres  have  been  devoted  to  the  continuous  growth  of  wheat  since  1843  8 
acres  to  continuous  growth  of  turnips  from  the  same  date,  and,  6  to  6  acres  to  that'of 
leguminous   corn   crops  since  1846.     And  of  field  experiments,  beside  these  which 
amount  in  each  year  to  from  30  to  40  on  wheat,  upwards  of  90  on  turnips,  and  20  to  80 
on  beans^  others  have  been  made,  viz.,  some  on  the  growth  of  clover,  and  some  in  rela- 
tion to  the  chemical  circumstances  involved  in  an  actual  course  of  rotation,  compriainir 
turnips,  barley,  clover,  and  wheat,  grown  in  the  order  in  which  they  are  here  itateA 
It  may  be  stated,  too,  that  m  addition  to  these  experiments  on  wheat,  and  the  other 
erops  usually  grown  upon  the  farm,  as  above  referred  to,  we  have  for  several  years  been 
much  occupied  also  with  the  subject  of  the  feeding  of  animals,  viz.  bullocks,  sheep,  and 
pigs,— as  wel  as  m  investigating  the  functional  actions  of  the  growing  plant  in  rela- 
tion to  the  soil  and  atmosphere ;  and  in  connection  with  each  of  theee  subjects  much 
laboratory  labor  has  constantly  been  in  progress. 

a  ri^^u  «««Pe  and  object  of  our  investigation  has  been  therefore  to  examine  in  the 
Held,  the  feeding  shed,  and  the  laboratory,  into  the  chemical  circumstances  connected 
with  the  a,griculture  of  Great  Britain  in  its  four  main  features ;  namely— 
♦i>  .     r^.u    ,  P''^^^ct^'on  of  <'he  cereal  grain  crops ;  secondly,  that  of  root  crops ;  thirdly 
that  of  the  leguminous  corn  and  fodder  crop;  and  fourthly,  and  lastly,  that  of  the 
consumption  of  food  on  the  farm  for  its  double  produce  of  meat  and  manure. 

bo  much  then  for  the  rationale  and  general  plan  of  the  experiments  themselves 
u  Ztu""^  propose  to  call  attention  to  some  of  the  results  which  they  have  afforded  ub! 

iQ.^  io.  J^^'  T^  P*""^  ^^  *^^  ^^^"^*^  ""^  ^^^  ^h«at  experiments  of  the  harvests  of 
1844,  1845,  and  1846,  and  of  these  seasons  only,  have  been  published ;  those  on  tur- 
nips, only  for  the  seasons  1843,  1844,  and  1845 ;  those  on  the  leguminous  crops  not  at 
all  as  yet ;  and  those  onfeeding,  only  as  far  as  sheep  are  concerned,  and  chiefly  too 
in  relation  to  the  one  pomt  only  of  the  increase  of  live  weiglU  obtained  from  a  given 
quantity  of  food,  or  its  constituents.  Of  the  laboratory  results,  but  few  have  been 
given  m  relation  to  any  of  these  branches  up  to  the  present  time.  The  vast  accumu- 
lation of  results  indeed,  will  necessarily  still  further  postpone  the  publication  of  them 
m  any  extended  form  ;  and  hence  it  seems  the  more  desirable  to  take  advantage  of  the 
present  opportunity  to  attempt  to  bring  together  into  one  view  some  of  the  general 
mdieations  which  have  been  arrived  at  in  relation  to  a  few  important  points. 

w  ith  this  view.  It  is  to  the  field  experiments  on  wheat  that  we  shall  chiefly  confine 
our  attention  on  this  occasion ;  for  wheat,  which  constitutes  the  principal  food  of  our 
population,  IS  with  the  farmer  the  most  important  crop  in  his  rotation,  all  others  beinc 
considered  more  or  less  subservient  to  it ;  and  it  is,  too,  in  reference  to  the  production 
of  this  crop  in  agricultural  quantity  that  the  mineral  theory  of  Baron  Liebiff  is  perhaps 
more  prominently  at  fault  than  in  that  of  any  other.     It  is  true,  that  in  the  case  of 
vegetation  in  a  native  soil,  manured  by  art,  the  mineral  constituent  of  the  plants  beine 
furnished  from  the  soil,  the  atmosphere  is  found  to  be  a  mjfficient  source  of  the  nitro^^en 
and  carbon;  and  it  is  the  supposition  that  these  circumstances  oi  natural  vegetation  aupW 
equally  l>o  the  various  crops  when  grown  wvdcr  cultivation  that  has  led  Baron  Liebie  to 
suggest  that,  if  by  artificial  means  we  accumulate  within  the  soil  itself  a  sufiiciently  lib- 
eral supply  of  those  constituents  found  in  the  ashes  of  the  plant,  essentially  soil  constitu- 
ents, we  shaU  by  this  means  be  able  in  all  cases  to  increase  thereby  the  assimilation  of  the 
vegetable  or  atmospheric  constituents  in  a  degree  sufficient  for  agricultural  purposes. 
But  agriculture  is  itself  an  aWi/?da/ process  ;  and  it  will  be  found  that,  as  regards  the 
production  of  wheat  more  especially,  it  is  only  by  the  accumulation  within  the  soil  iteelf 
Vol.  11.  g  "^  ^ 


I 


114 


MANURE. 


I     '.-A 


I 


i\ 


tir 


r^ 


ii 


of  nitrogen  naturally  derived  from  the  atmosphere,  rather  than  of  the  peculiarly  soil 
constituenta,  that  our  crops  of  it  cain  be  incre^ised.  Mineral  substances  will,  indeed, 
materially  develope  tlie  accumulation  of  vegetable  or  atmospheric  constituents  when 
applied  to  »onie  of  the  crops  of  rotation  ;  and  it  is  thus  chiefly  that  these  crops  becom* 
subservient  to  the  growth  of  the  cereal  grains,  but  even  in  these  cases  it  is  not  the  con- 
stituents, as  found  collectively  in  the  ashes  of  the  plants  to  be  grmoiiy  that  are  the  most 
efficient  in  this  respect ;  nor  can  the  demand  which  we  find  thus  made  for  the  produc- 
tion of  crops  '\ii  agricultural  quantity  be  accounted  for  by  the  mere  idea  of  supplying 
the  actual  constitueuts  of  the  crop.  It  would  seem,  therefore,  that  we  can  only  arrive 
at  correct  ideas  in  agriculture  by  a  close  examination  of  the  actual  circumstances  of 
growth  of  each  particular  crop  when  grown  under  cultivation.  We  now  turn  to  the 
consideration  of  our  experiments  upon  this  subject.  It  has  been  said  that  all  the  ex- 
perimental fields  were  selected  when  they  were  in  a  state  of  agricultural  exhaustion. 
iTie  wheat  fields,  however,  after  having  been  manured  in  the  usual  way  for  tur- 
nips at  the  commencement  of  the  previous  rotation,  had  then  grown  barley,  peas,  wheat, 
and  oats,  without  any  further  manuring  ;  so  that  when  taken  for  experiment  in  1844,  it 
was,  as  a  grain-producer,  considerably  more  exhausted  than  would  ordinarily  be  the 
case.  It  was,  therefore,  in  a  most  favorable  condition  for  the  purposes  of  our  experi- 
ments. 

"In  the  first  experimental  season,  the  field  of  14  acres  was  divided  into  about  20  plots, 
and  it  was  by  the  mineral  theory  that  we  were  mainly  guided  in  the  selection  of  ma- 
nures :  mineral  manures  were  therefore  employed  in  the  majority  of  cases.  Ammonia, 
on  tlie  other  hand,  being  then  considered  as  of  less  importance,  was  used  in  a  feir 
instances  only,  and  in  these  in  very  insignificant  quantities.  Rape-cake,  as  being  a  well 
recognised  manure,  and  calculated  to  supply,  besides  some  minerals  and  nitrogen,  a 
certain  quantity  of  carbonaceous  substance  in  which  both  corn  and  straw  so  much 
abound,  was  also  added  to  one  or  two  of  the  plots. 

Table  1. — Harvest  1844.     Summary. 


Dressed  Ck>ni 

Total 

Straw 

Description  of  the  Man  ores. 

per  Acre, 

Com 

per  Acre, 

in  Bushels 

per  Acre, 

inlb& 

and  Pecks. 

inlb& 

bush. 

pecks 

lbs. 

llM. 

Plot  3.  Unmanured        .        .        .         - 

16 

0 

923 

1120 

"    2.  14  tons  of  farm-yard  manure 

22 

0 

1276 

1476 

"    4.  The  ashes  of  14  tons  of  farm  manure 

16 

0 

888 

1104 

"    8.  Minimum  produce  of  9  plots,  with  ar-   1 

tificial  mineral  manures     - 

Superphosphate  of  lime  350  lbs.  - 
Phosphate  of  potass  364  lbs. 

' 

16 

1 

980 

1160 

Plot  15.  Maximum  produce  of  9  plots  with  ar-  1 

tificial  mineral  manures  - 

Superphosphate  of  lime  350  lbs. 

Phosphate  of  Magnesia  168  lbs.  -     ' 
ao             potass  150  lbs 

17 

3^ 

1096 

1240 

Silicate            do.      112  lbs. 

Mean  of  the  9   plots  with  artificial  mineral  ma- 

nures         

16 

3* 

1009 

1155 

Mean   of  3  plots  with  mineral  manures,  and  65 

lbs.  each  of  sulphate  of  ammonia 

21 

0 

1275 

1423 

Mean  of  2  plots  with  mineral  manures,    and  150 

lbs.  and  160  lbs.  of  rape-cake  respectively 

18 

1* 

1078 

1201 

Plot  18.  With  complex  mineral  manure,  55  lbs.  of 

sulphate  of  ammonia,  and  150  lbs.  of  rape-cake 

22 

H 

1368 

1768 

"The  indications  of  the  table  are  seen  to  be  most  conclusive,  as  showing  what  was 
the  character  of  the  exhaustion  which  had  been  induced  by  the  previous  heavy  crop- 
ping, and  what,  therefore,  should  be  the  peculiar  nature  of  the  supply  in  a  rational 
system  of  manuring.  If  the  exhaustion  had  been  connected  with  a  deficiency  of 
mineral  constituents,  we  might  reasonably  have  expected  that  by  some  one  at  least 
of  the  nine  mineral  conditions, — supposing  in  some  cases  an  abundance  of  every  min- 
eral constituent  which  the  plant  could  require, — this  deficiency  would  have  been  made 
up;  but  it  was  not  so. 

"  Thus,  taking  the  column  of  bushels  per  acre  as  given  in  this  summary  a«  our  guide, 
it  will  be  seen  that  whilst  we  have  without  manure  only  16  bushels  of  dressed  corn,  we 


MANURE. 


115 


kave  by  farm-yard  manure  22  bushels.  The  ashes,  of  farm-yard  manure  give,  however 
no  increase  whatever  over  the  unmanured  plot  Again,  out  of  the  9  plots  supplied 
with  artihcial  mineral  manures,  we  have  in  no  case  an  increase  of  2  bushels  bv  this 
means;  the  produce  of  the  average  of  the  9  being  not  quite  17  bushels.  On  the  other 
hand  we  see  that  these  addition  to  some  of  the  purely  mineral  manures  of  65  lbs.  of  sul- 
phate of  ammonia— a  verj.'  small  dressing  of  that  substance,  and  containing  only  about 
14  lbs  of  an.mon.a-has given  us  an  average  produce  of  21  bushels.  An  insignificant 
addition  of  rape-cake  too,  to  manures  otherwise  ineffective,  has  given  us  about  18i 
bushels;  and  when,  as  in  plot  18.,  we  have  added  to  the  inefficient  mineral  manur4 

tWn  .  ^;  *"f"»^»'a«»]  salts,  and  a  I'ttle  rapenjake  also,  we  have  a  produce  greater 
man  by  the  14  tons  of  farm-yard  manure. 

.^a7^^  Tt'^f^l^^  ""^  rape-cake  used  were  small,  and  the  increase  attributable  to  it 
aJso  small,  but  it  nevertheless  was  much  what  we  should  expect  when  compared  with 
that  from  the  ammon.acal  salts,  if,  as  we  believe  is  the  case,  the  effect  of  rape-cake 
on  grain-crops  is  due  to  the  nitrogen  it  contains.  ^ 

"Indeed,  the  coincidence  in  the  slight  or  non-effect  throughout  the  mineral  series 
on  the  one  hand,  and  of  the  marked  and  nearly  uniform  result  of  the  nitrogenous  sup- 
ply on  the  other,  was  most  striking  in  the  first  year's  experimental  produce,  and  such 
as  to  lead  us  to  give  to  nitrogenous  manures  in  the  second  season  even  greater  Dromi- 
^.Tl  r  iT''  *^  ^^"^^  to  minerals  in  the  previous  one.  This  is  in  some  respects, 
perhaps,  to  be  regretted,  as  had  we  kept  a  series  of  plots  for  some  years  continuously 
under  minerals  alone,  the  evidence,  though  at  present  sufficiently  conclusive,  would 
Have  carried  with  it  somewhat  more  of  systematic  proof. 

^.r/^fTt^lf  II:  "^^  ^^^""^^  ?''t°  *  ^^"^  .''^^"^^  selected  from  those  obtained  at  the  har- 
vest of  1845  the  second  of  the  experimental  series.  By  the  tai>le  it  is  seen  tliat  we 
have,  at  the  harvest  of  1845,  a  produce  of  rather  more  than  23  bushels  without  manure 
of  any  kind,  instead  of  only  16  as  in  1844 ;  and  in  like  manner  the  farm-yard  manure 
Jives  32  bushels  m  845  and  only  22  in  1844.  We  have  shown  in  a  fo:^er  dumber 
of  the  Journal  how  clearly  these  differences  can  be  traced  to  variations  in  the  climatic 
character  of  the  season,  but  this  is  not  the  point  under  consideration  just  now. 

Table  If.— Harvest  1845.     Selected  results. 


DescripUon  and  Quantities  of  the  Manures  per  Acre. 


Dressed  Com 

per  Acre 

in  Basbels 

and  Peeks. 


Section  1. 

Plot  3.  No  manure  .... 

2.  14  tons  of  farm-yard  manure 

Section  2. 

**  ha.  No  manure        ..... 

"  56.  Top-dressed  with  252  lbs.  of  carbonate 
t»f  ammonia  (dissolved),  at  3  times, 
during  the  spring     .... 

Section  3. 
"   9  J  Sulphate  of  ammonia  168  lbs.  )  top-dress'd 

*  {  Muriate  of  ammonia  168  lbs.    j"    at  once 
"  10.  \  ^"'P''ate  of  ammonia  168  lbs.  (  top-dress'd 
J  Muriate  of  ammonia  168  lbs.  j  at  4  times. 


bosh,    peeks. 

23     0| 
32     Oi 


22  2i 

26  3| 

33  \\ 

31  3i 


Total 

Corn 

per  Acre, 

in  lbs. 


lbs. 

1441 
1967 


1431 
1732 

2181 
1980 


Straw 

per  Acre, 

in  lbs. 


lbs. 

2712 
3915 


2684 

3599 

4058 
4266 


"  We  a.«^sume.  then.  23  bushels  or  thereabouts  to  be  the  standard  produce  of  the  soil 
S  ht^!?nn,Ti  "  «i''n«re,  during  this  second  experimental  year ;  and  as  part  of  plot 
ma l^iro  ril  T^'^^  With  superphosphate  of  lime),  and  whfch  i^now,  also,  without 

3r^f  n1«t%  .h^'  ""^'^  ^^'^'\  2'^*  ^"^^"^^  ""^  ^^^«^«^  ««^"'  ^»'^  correctne^  of  the 
^Twl  Plf  V  .  P«™anently  unmanured  plot,  is  thereby  fully  confirmed, 
inf^  fu^nUnn  1  '  5  prcviously  two-thirds  of  au  acre,  was,  in  this  second  year,  divided 
^aZrT^\Kl\T'''''''^  ^^^^^«^  <'P^^*  ^«')  ^«»»g'  »«  J»«t  said,  unmanured,  and 
!^^in,  h/  ^  }-^  )  having  supplied  to  it  in  silution,  by  top-dressings  during  the 
spring,  the  medtctnal  carbonate  of  ammonia,  at  the  rate  of  260  lbs.  per  acre  ;  and  it  is 

rwS  ^rnm'JrK'  'ZV"!  '^""^  but  highly  volatile  ammoniacal  salt  alone,  the  produce 
raised  from  22 J  bushels  to  very  nearly  27  bushels! 

-  In  the  next  section  of  the  table  are  given  the  results  of  plot*  9.  and  10.,  the  formw  ot 


p 


116 


MANURE. 


which  had  in  the  previons  year  been  manured  by  superphosphate  of  lime  and  a  small 
quantity  of  sulphate  of  ammonia,  and  the  latter  by  superphosphate  of  lime  and  silicate 
of  potass.  To  each  of  the  plots  IJ  cwt  of  sulphate  and  U  cwt  of  muriate  of  ammo- 
nia were  now  supplied.  Upon  plot  9.  the  whole  of  the  manure  was  top-dressed,  at 
once,  early  in  the  spring ;  but  on  plot  10.  the  salts  were  put  on  at  four  successive  peri- 
ods. Theproduce  obtained  by  these  salts  of  ammonia  alone  is  33  bushels  and  three- 
eighths,  when  sown  all  at  once,  and  nearly  32  bushels  when  sown  at  four  different  times 
— quantities  which  amount  to  about  10  bushels  per  acre  more  than  was  obtained  with- 
out manure.  In  the  case  of  No.  9.,  indeed,  the  produce  exceeds  by  1^  bushel  that 
given  by  farm-yard  manure,  and  in  that  of  No.  10.  it  is  all  but  identical  with  it  And 
if  we  take  the  weights  of  total  com,  instead  of  the  measure  of  the  dressed  corn,  to 
which  latter  we  chiefly  refer,  merely  as  a  standard  more  conventionally  understood. 
No.  10.,  by  ammonia  only,  has  given  both  more  corn  and  more  straw  than  the  farm- 
yard manure,  with  all  its  minerals  and  carbonaceous  substance. 

"  Let  us  see  whether  this  almost  specific  effect  of  nitrogen,  in  restoring,  for  the  re- 
production of  corn,  a  corn-exhausted  soil,  is  borne  out  by  the  results  of  succeeding 
years. 

"We  should  have  omitted  all  reference  to  the  results  obtained  with  the  wheat  ma- 
nure of  Professor  Liebig,  had  not  the  professor,  in  the  new  edition  of  his  '  Letters,* 
whilst  fully  admitting  the  failure  of  the  manure — the  composition  of  which,  to  use  his 
own  words  when  commenting  upon  it,  *  could  be  no  secret,  since  every  plant  showed 
by  its  ashes  the  due  proportion  of  the  constituents  essential  to  its  growth '  (page  482), 
— not  expressed  any  doubt  as  to  the  principle  involved  in  such  a  manure,  but  on 
the  other  hand,  implied  that  the  failure  was  due  to  a  yet  imperfect  knowledge  of  the 
mechanical  form  and  chemical  qualities  required  to  be  given  to  the  necessary  con- 
stituents in  order  to  fit  them  for  their  reception  and  nutritive  action  on  the  plant, 
rather  than  to  any  fallacy  in  the  theory  which  would  recommend  to  practical  agri- 
culture the  supply  by  artificial  means  of  the  constituents  of  the  ashes  of  plants  as 
manures. 

"The  following  table  gives  our  selection  of  the  resultfi  of  the  third  senson,  1846:— 

Table  IIL — Harvest  1846.     Selected  Result.?. 


DMcription  and  Quantities  of  the  Ifanures  per  Acre. 


Section  1. 
Plot  3.  No  manure     .        .        .        . 
"  2.  14  tons  of  farm-yard  manure 


t( 


Section  2. 
106.  No  manure 
"  10a.  Sulphate  of  ammonia  224  Iba 


Dressed  Corn 

per  Acre, 

in  Bushels 

and  Pecks. 


Total 

Com 

per  acre, 

in  lbs. 


K 


5a\ 
5a\ 


Section  3. 

Ash  of  8  loads  of  wheat  straw     . 

Ash  of  8  loads  of  wheat  straw,  and  top- 
dressed  with  224  lbs.  of  sulphate  of 
ammonia 


Section  4. 

6a.  Liebig's  wheat  manure  448  lbs.    . 

66.  Liebig's  wheat  manure  448  lbs.,  with 
112  lbs.  each  of  sulphate  and  muriate 
of  ammonia 


bash,     pecks. 

17     8| 
«7     0| 


17     2J 
27     1| 


19  Oi 
27  0 

20  U 
29  Of 


lbs. 

1207 
1826 


1216 
1860 


1400 
1967 


Straw 

per  Aero, 

in  lbs. 


lbs. 

1513 
2454 


1455 
2244 


1541 
2309 
1676 
2571 


At  this  third  experimental  harvest  we  have  on  the  continuously  unmanured  plot, 
namely.  No.  3.,  not  quite  18  bushels  of  dressed  corn,  as  the  normal  produce  of  the 
aeason ;  and  by  ita  side  we  have  on  plot  106 — comprising  one-half  of  the  plot  10 
of  the  previous  years,  and  so  highly  manured  by  ammoniacal  salts  in  1845  but 
now  unmanured  —rather  more  than  17  i  bushels.  The  near  approach,  again  to 
Identity  of  result  from  the  two  immanured  plots,  at  once  gives  confidence  in  the 
accuracy  of  the  experimente,  and  shows  us  how  effectually  the  preceding  crop  had. 
ma  practical  point  of  view,  reduced  the  plots,  previously  so  differently  circumstanced 
both  as  to  manure  and  produce,  to  something  Uke  an  uniform  standard  as  regards 


MANURE. 


117 


their  grain-producing  qualities.-  "We  take  this  opportunity  of  particularly  calling  atten- 
tion to  these  coincidences  in  the  amount  of  produce  in  the  two  unmanured  plots  of 
the  different  years,  because  it  has  been  objected  against  our  experiments,  as  already 
published,  that  confirmation  was  wanting  as  to  the  natural  yield  of  soil  and  season. 

"  Plot  2  has,  as  before,  14  tons  of  farm-yard  manure,  and  the  produce  is  27^  bushels, 
or  between  9  and  10  bushels  more  than  without  manure  of  any  kind. 

"  On  plot  10a,  which  in  the  previous  year  gave  by  ammoniacal  salts  alone  a  pro- 
duce equal  to  that  of  the  farm-yard  manure,  we  have  again  a  similar  result :  for  2  cwt. 
of  sulphate  of  ammonia  has  now  given  1850  lbs.  of  total  corn,  instead  of  1826  lbs., 
which  is  the  produce  on  plot  2.  The  straw  of  the  latter  is,  however,  slightly  heavier 
than  that  by  the  ammoniacal  salt 

"Again,  plot  6a,  which  was  in  the  previous  season  unmanured,  was  now  subdivided : 
on  one-half  of  it  (namely,  5a*)  we  have  the  ashes  of  wheat-straw  alone,  by  which  there 
is  an  increase  of  rather  more  than  1  bushel  per  acre  of  dressed  corn ;  on  the  other 
half  (or  6')  we  have,  besides  the  straw  ashes,  2  cwts.  of  sulphate  of  ammonia  put  on  as 
a  ton-dressing:  2  cwts.  of  sulphate  of  ammonia  have,  in  this  case,  only  increased  the 
proauce  beyond  that  of  5a*  by  7|  bushels  of  corn  and  768  lbs.  of  straw,  instead  of  by 
9i  bushels  of  corn  and  789  lbs.  of  straw,  which  was  the  increase  obtained  by  the  same 
amount  of  ammoniacal  salt  on  lOo,  as  compared  with  106.  It  will  be  observed,  how- 
ever, that  in  the  former  case  the  ammoniacal  salts  were  top-dressed,  but  in  the  latter 
they  were  drilled  at  the  time  of  sowing  the  seed ;  and  it  will  be  remembered  that  in 
1845  the  result  was  better  as  to  corn  on  plot  9,  where  the  salts  were  sown  earlier, 
than  on  plot  10,  where  the  top-dressing  extended  far  into  the  spring.  We  have  had 
several  direct  instances  of  this  kind  in  our  experience,  and  we  would  give  it  as  a  sug 
gestion,  in  most  cases  applicable,  that  manures  for  wheat,  and  especially  ammoniacal 
ones,  should  be  applied  before  or  at  the  time  the  seed  is  sown ;  for  although  the  ap- 
parent luxuriance  of  the  crop  is  greater,  and  the  produce  of  straw  really  heavier,  by 
spring  rather  than  autumn  sowings  of  Peruvian  guano  and  other  ammoniacal  manures, 

fet  we  believe  that  that  of  the  corn  will  not  be  increased  in  an  equivalent  degree, 
ndeed,  the  success  of  the  crop  undoubtedly  depends  very  materially  on  the  progress 
of  the  underground  growth  during  the  winter  months;  and  this  again,  other  things 
being  equal,  upon  the  quantity  of  available  nitrogenous  constituents  within  the  soil, 
without  a  liberal  provision  of  which,  the  range  of  the  fibrous  feeders  of  the  plant  will 
not  be  such  as  to  take  up  the  minerals  which  the  soil  is  competent  to  supply,  and  in 
•uch  quantity  as  will  be  required  during  the  after  progress  of  tie  plant  for  its  healthy 
and  favorable  growth. 

"The  next  result  to  be  noticed  is  that  obtained  on  plot  6,  now  also  divided  into  two 
equal  portions,  designated  respectively  6a  and  66.     Plot  No.  6  had  for  the  crop  of 

1844  superphosphate  of  lime  and  the  phosphate  of  magnesia  manure,  and  for  that  of 

1845  superphosphate  of  lime,  rape-cake,  and  ammoniacal  salts.     For  this  the  third  ex 
periraental  season,  it  was  devoted  to  the  trial  of  the  wheat  manure  manufactured 
under  the  sanction  of  Professor  Liebig,  and  patented  in  this  country, 

"  Upon  plot  6a  4  cwts.  per  acre  of  the  patent  wheat-manure  were  used,  which  gave 
20i  bushels,  or  rather  more  than  2  bushels  beyond  the  produce  of  the  unmanured 
plot ;  but  as  the  manure  contained,  besides  the  minerals  peculiar  to  it,  some  nitrogen- 
ous compounds,  giving  off  a  very  perceptible  odor  of  ammonia,  some,  at  least,  of  the 
increase  would  be  due  to  that  substance.  On  plot  66,  however,  the  further  addition 
of  1  cwt  each  of  sulphate  and  muriate  of  ammonia  to  this  so-called  "mineral  manure** 
gives  a  produce  of  29^  bushels.  In  other  words,  the  addition  of  ammoniacal  salt  to 
Liebig's  mineral  manure  has  increased  the  produce  by  very  nearly  9  bushels  per  acre 
beyond  that  of  the  mineral  manure  alone,  whilst  the  increase  obtained  over  the  un- 
manured plot  by  14  tons  of  farm-yard  manure,  was  only  9^  bushels. 

"  If,  then,  the  *  mechanical  form  and  chemical  qualities '  of  the  so-called  *  mineral 
manure'  were  at  fault,  the  sulphate  of  ammonia  has,  at  least,  compensated  for  the  de- 
fect; and  even  supposing  a  mineral  manure,  founded  on  a  knowledge  of  the  composi- 
tion of  the  ashes  of  the  plant,  be  still  the  great  desideratum,  the  farmer  may  rest  con- 
tented, meanwhile,  that  he  has  in  ammonia,  supplied  to  him  by  Peruvian  guano,  by 
ammoniacal  salts,  and  by  other  sources,  so  good  a  substitute. 

"  It  surely  is  needless  to  attempt  further  to  justify,  by  the  results  of  individual  years, 
our  assertion,  that  in  practical  agriculture  nitrogenous  manures  are  peculiarly  a(Japted 
to  the  growth  of  wheat  We  shall  therefore  conclude  this  part  of  our  subject  by  di- 
recting attention  to  the  history  of  a  few  of  the  plots  throughout  the  entire  series  of 
years,  as  compared  with  that  of  the  unmanured  plot  during  the  same  period. 

"  In  support  of  the  view  that  leguminous  plants  do  possess  a  superior  power  of  reli- 
ance upon  the  atmosphere  for  their  nitrogen,  and,  indeed,  that  it  is  to  this  property 
that  they  materially  owe  their  efficacy  in  rotation  with  grain,  we  may  refer  to  the 
admirable  investigations  into  the  chemistry  of  agriculture  of  M.  Boussingault  His 
experiments,  however,  have  not  received  the  attention  which  they  merit  from  the 


II 


I 


118 


MANURE. 


ftli 


!  I    ii 


a^cultunsts  of  this  country ;  probably  on  account  of  the  small  amounts  of  produce 
wmch  he  obtained.  But  it  must  be  remembered  that  his  investigation  had  for  its  ob- 
ject to  explain  the  practices  of  agriculture  as  he  found  them  in  his  own  locality,  before 
attemptmg  to  deviate  from  ite  established  rules.  M.  Boussingault  states  the  rotation 
follow^-—    ^^    **  Bechelbronn,  and  throughout  the  greater  part  of  Alsace,  to  be  as 

"Potatoes  or  beet-root;"         "Wheat;"         "Clover;"         "Wheat-" 
and  that  the  average  of  wheat  so  obtained  is,  after  potatoes  19i  bushels,  after  beet- 
root 17  bushels,  after  clover  24  bushels.     Now  we  find  by  reference  to  his  table  that 
tne  first  crop  of  wheat,  grain,  and  straw  removed  17  lbs.  of  phosphoric  acid  and  24  lbs. 
oi  potash  and  soda;  the  following  clover  crop.  18  lbs.  of  phosphoric  acid  and  11  lbs 
potash  and  soda;  and  after  this  removal  of  alkalis  and  phosphates  by  the  clover  a 
larger  crop  of  wheat  is  obtained.     Surely  it  would  seem  impossible  to  reconcile  this 
result  with  a  theory  which  supposes  the  produce  of  wheat  to  rise  and  fall  with  the 
quantity  of  minerals  available  within  the  soil.   If,  however,  we  admit  that  the  first  crop 
oi  wiieat  could  not  take  up  the  mineral  matters  existing  in  the  soil  for  want  of  nitro- 
genous supply,  and  that  the  clover  crop,  not  being  so  dependent  upon  supplied  nitro- 
gen, was  able  to  take  up  the  mineraU  required  for  its  growth,  and  that  it  moreover 
leic  m  tne  soil  sufficient  ammonia,  or  its  equivalent  of  nitrogen  in  some  form,  to  give 
tne  «ncrea«?rf  crop  of  wheat,  we  have  a  much  more  consistent  and  probable  solution  of  the 
results.     Ihere  is  httle  doubt  that  M.  Boussingault  could  have  increased  his  produce 
ot  Wheat  by  means  of  araraoniacal  salts :  whether  he  could  have  done  so  economically 
18  anther  ^uestion^  depending  of  course  upon  the  relative  prices  of  grain  and  ammonii 
ihe  striking  effect  of  phosphoric  acid  upon  the  growth  of  the  turnip,  indeed,  is  a 
lact  so  well  known  to  every  intelligent  agriculturist  in  Great  Britain,  that  it  would 
seem  quite  superfluous  to  attempt  to  illustrate  it  by  any  direct  experiments  of  our 
own.     However,  as  Professor  Liebig  has  again,  in  the  recent  edition  of  his  'Letters ' 
expressed  an  opinion  entirely  inconsistent  with  such  a  result,  we  will  refer  to  one  or 
two  of  the  results  obtained  in  our  experimental  turnip-field,  which  bear  upon  the 
opinion  he  has  reiterated  as  follows:  thus,  speaking  of  the  exhaustion  of  phosphate 
Ot  lime  and  alkaline  phosphates  bv  the  sale  of  flour,  cattle,  Ac,  he  says :— '  It  is  certain 
tnat  tills  incessant  removal  of  the  phosphates  must  tend  to  exhaust  the  land  and 
dimmish  Its  capability  of  producing  grain.     The  fields  of  Great  Britain  are  in  a  state 
01  progressive  exhaustion  from  this  cause,  as  is  proved  by  the  rapid  extension  of  the 
cultivation  of  turnips  and  mangold-wurzel,  plants  which  contain  the  least  amount  of 
tne  pliosphates,  and  tukrkfork  require  the  smallest  QUANTrrv  for  their  developme.nt  * 
l^ow  we  do  not  hesitate  to  say  that,  however  small  the  quantity  of  phosphates  con- 
tained in  the  turnip,  the  successful  cultivation  of  it  is  more  dependent  upon  a  large 
supply  of  phosphoric  acid  in  the  manure  than  that  of  any  other  crop. 

In  the  following  table,  then,  is  given  the  amounts  of  bulb,  since  1843,  of— 
*ir8t,  the  continuously  unmanured  plot; 

Secondly,  that  with  a  large  amount  of  the  superphosphate  of  lime  alone  each  year ;  and 
inirdly,  that  with  a  very  liberal  supply  of  potash  with  some  soda  and  magnesia 
also,  in  addition  to  superphosphate  of  lime. 


MANURE. 


119 


1 

Plot 

Plot 

Plot 

Yearsw 

continnoosly  Un- 

with 

Superphosphate 

with 

8ui)erphosphate 

manured. 

of  Lime  alone  every 

of  Lime  and  mixed       I 

Year. 

Alkalis. 

Tonst  cwts.    qrs. 

lb8. 

Tons. 

cwts.    qrs.    Iba. 

Tons. 

cwts.    qn.    Ibai 

1843 

4       3       8 

2 

12 

3       2       8 

11 

17        2       0 

1844 

2       4       1 

0 

1 

14       8       0 

5 

13       2       0 

1846 

0     13      2 

24 

12 

13       8     12 

12 

12       2       8 

1846 

—    — -  — 

•—. 

1 

18       0       0 

3 

10       1     20 

1847 

—    _    _« 

— 

6 

11       0       1 

5 

IC      0      0 

1848 

—    —    — 

— 

10 

11       0       8 

9 

14      2      0 

1849 

—    —.    — 

— 

3 

15       0      0 

8 

13      2      8 

1850 

—    — •  — 

— 

11 

9       0       0 

9 

1       1     12 
5       1     20 

Totals. 

—    —    —    — 

65 

16       1       1 

62 

Means. 

—    —    — 

— 

8 

4      2      4 

1 

15       2     20 

"It  18  seen  then,  that  in  the  third  season,  viz.  1845,  the  produce  of  the  unmanured 
plot  is  reduced  to  a  few  hundred  weight*,  and  since  that  period  the  size  of  the  bulbs  had 
been  such  that  they  have  not  been  considered  worth  weighing.  On  the  other  hand  on 
the  plot  with  mperphosphate  of  lime  alone  for  eight  successive  years,  we  have  an  average 
produce  of  about  8i  tons  of  bulb !  varying,  however,  exceedingly,  year  by  year  acco^- 


ing  to  the  season.  We  see,  too,  that  by  the  addition  to  superphosphate  of  lime  of  a 
large  quantity  of  the  alkalis,  much  greater  than  could  be  taJcen  off  in  the  crop,  the 
average  produce  is  not  so  great  by  nearly  half  a  ton  as  by  the  superphosphate  of  lime 
alone.  It  must  be  admitted  that  this  extraordinary  effect  of  superphosphate  of  lim« 
cannot  be  accounted  for  by  the  idea  of  merely  supplying  in  it  the  actual  constituents 
of  the  crop,  but  that  it  is  due  to  some  special  agency  in  developing  the  assimilative 
processes  of  the  plant  This  opinion  is  favored  by  the  fact  that  in  the  case  where 
the  superphosphate  of  lime  is  at  once  neutralized  by  alkalis  artificially  supplied,  the 
efficacy  of  the  manure  would  seem  to  be  thereby  reduced.  And  from  this  again,  we 
would  gather  that  the  effect  of  the  phosphoric  acid,  as  such,  cannot  be  due  mereU'  to 
the  liberation  within  the  soil  of  its  alkalis,  or  we  should  suppose  that  the  artificial 
supply  of  these  would  at  least  have  been  attended  with  some  increase  of  produce. 
But  this  is  not  the  case,  notwithstanding  that  by  means  of  superphosphate  of  lime 
alone  there  has  been  taken  from  the  land  more  of  the  alkalis  in  which  the  ash  of  the 
turnip  so  peculiarly  abounds,  than  would  have  been  lost  from  it  in  a  century  under 
the  ordinary  course  of  rotation  and  home  manuring!  Collateral  experiments  also 
clearly  prove  the  importance  of  a  liberal  supply  of  organic  substance  rich  in  car6o» 
— which  always  contains  a  considerable  quantity  of  nitrogen  also — if  wo  would  in 
practical  agriculture  increase  the  yield  much  beyond  the  amount  which  can  be  ob- 
tained by  mineral  manures  alone ;  and  these  conditions  being  fulfilled,  the  direct  supply 
of  nitrogen,  on  the  other  hand,  is  by  no  means  so  generally  essential.  And  it  is  where 
we  have  provided  a  liberal  supply  of  constituents  for  organic  formations,  in  addition 
to  the  mineral  manures,  that  we  have  found  the  use  of  alkalis  not  to  be  without  effect 
**  But  it  is  at  any  rate  certain  that  phosphoric  acid, though  it  forms  so  small  a  proportion 
of  the  ash  of  the  turnip,  has  a  very  striking  effect  on  its  growth  when  applied  as  ma- 
nure; and  it  is  equally  certain  that  the  extended  cultivation  of  root  crops  in  Great 
Britain  cannot  be  due  to  the  deficiency  of  this  substance  for  the  growth  of  corn,  and 
to  the  less  dependence  upon  it  of  the  root  crops,  as  supposed  by  Baron  Liebig. 

"  These  curious  and  interesting  facts  in  relation  to  the  growth  of  turnips,  as  well  at 
those  which  have  been  given  in  reference  to  wheat  and  to  the  leguminous  crops,  are 
eufficient  to  prove  how  impossible  it  is  to  form  correct  opinions  on  agricultural  chemistry 
without  the  guidance  of  direct  experiment  in  the  field.  And  we  are  convinced  that  if 
Baron  Liebig  had  watched  the  experiments  which  we  have  had  in  progress  during  the 
last  eight  years,  he  would  long  ago  have  arrived  at  conclusions  in  the  main  agreeing 
with  tJnose  to  which  we  have  been  irresistibly  led:  and  we  are  disposed  to  believe 
tliat  had  he  even  seen  the  more  detailed  accounts  of  our  results  given  in  our  own 
papers  in  this  Journal,  instead  of  the  mere  reference  to  them  made  by  Mr.  Pusey,  he 
would  rather  have  accepted  them,  as  a  step  in  an  inquiry  to  which  his  own  researches 
auid  writings  had  given  such  an  impetus,  than  have  designated  them,  as  he  has  done, 
aa  entirely  without  value. 

"So  mucli,  then,  for  the  results  of  experiments  in  the  field,  and  for  the  considera- 
tions in  relation  to  the  functional  actions  of  plants,  as  bearing  upon  the  character  of 
the  manure  required  for  their  growth  in  a  course  of  practical  agriculture.  Let  us  now 
consider  for  a  few  moments  what  really  are  the  main  and  characteristic  features  of 
practical  ^riculture,  as  most  generally  followed  in  this  country. 

"  Let  us  suppose  that  the  rotation  adopted  is  that  of  turnips,  barley,  clover,  wheat ; 
that  the  turnips  and  clover  are  consumed  upon  the  farm  by  stock,  and  that  the  meat  thus 
produced,  40  bushels  of  barley  and  30  bushels  of  wheat,are  all  the  exports  from  the  farm, 
the  manure  from  the  consumed  turnips  and  clover,  and  the  straw,  both  of  barley  and  of 
wheat  being  retained  upon  the  farm.  We  have  in  this  case,  by  the  sale  of  grain,  a  loss 
of  minerals  to  each  acre  of  the  farm  of  only  20  to  24  pounds  ot  potass  and  soda,  and  26 
to  30  pounds  of  phosphoric  acid,  in  the  course  of  the  rotation,  or  an  average  of  5  to  6  lbs. 
of  potass  and  soda,  and  ^\Ui1\\h%  oi  phosphoric  acid  per  acre  per  annum.  In  the  sale 
of  the  animals  there  would  of  course  be  an  additional  loss  of  phosphoric  acid,  though, 
especially  if  no  breeding  stock  were  kept,  this  would  be  even  much  less  considerable 
than  in  that  of  the  grain ;  and  the  amount  of  the  alkalis  thus  sent  off  the  farm  would, 
according  to  direct  experiments  of  our  own  upon  calves,  bullocks,  lambs,  sheep,  and 

{)igs,  probably  be  only  about  one-fourth  that  of  the  phosphoric  acid.  It  has,  however, 
ong  been  decided  in  practical  agriculture  that  phospnoric  acid  may  be  advantageously 
provided  in  the  purchase  of  bones  or  other  phosphatic  manures,  though  in  practice 
these  are  not  found  applicable  as  a  direct  manure  for  the  wheat  crop ;  and  as  we  have 
already  said,  even  when  employed  for  the  turnip,  its  efficacy  is  not  to  be  accounted 
for  merely  as  supplying  a  sufficiency  of  that  substance  to  be  stored  up  in  the  crop. 

"  In  conclusion,  then:  if  the  theory  of  Baron  Liebig  simply  implies  that  the  growing 
plant  must  have  within  its  reach  a  sufficiency  of  the  mineral  constituents  of  which  it  ia 
to  be  built  up,  we  fully  and  entirely  assent  to  so  evident  a  truism ;  but  if,  on  the  otlxer 
h«n«l,  he  would  have  it  understood,  that  it  is  of  the  mineral  constituents,  as  w^e^uldbe 
eoilcctivcli/  found  in  the  ashes  of  the  exported  produce,  that  our  soils  are  deficient  rela- 
tively to  other  constituents,  and  that  in  the  present  condition  of  agriculture  in  Great 


I 


120 


MARBLE. 


s    f 


this  point,  IS  unfavorable   to  such  a  view.     We  have  beforp«i«fI5   fi.  ♦  v        , 

Tver  oi  Mr  Law«  Ln'n  "^r  .r"??  "'  ^''™''  ^"^'S-  S'""'  «>«  experCn^  W- 
S  ml       X5        "y"!  Dr.  Gilbert  have,  as  I  hear,  been  disputed,  I  am  bound  to  sav 

.trenXued  bv  a  !„b  '^'  f^R^'o-^  ^''""'cy  of  those  gentlemen  has  bieu  ."J 
phTlofopher  MJ„^DlT'°^^'''^'^^ft"'"^^^^^  company  with  that  eminent 
£t  w3ir'  ir  t  ""?'»»•  The  extent  of  the  experimental  ground— the  expenditure 
at  which  It  has  been  kept  up-the  perseverance  with  which,  year  after  year  it  his 

Zr^?'      •.r°'  ^^«"*<Jry. portable  manure,calledj^Wr.«.,i8uL  Sd  in  its  n^^^^ 

neighborhood.    The  ammonia.  atVeH  Ttttp^^^^^^^^ 

gen  which  together  concur  to  produce  the  nauseous  effluvia,  areT  once  con deVs^ 
by  this  salt;  the  ammonia  bj^  its  ac  d,  and  the  eases  bv  it<*  ovi.l/  wkI^  f^"*^^^/^ 
content^ofacesspool  are  m/xed  with"  a  little  er::i^heySt  bllome  neaSv  [^ 
odorous.    This  cheap  metallic  compound  should  U  applied,  under  the  adminUtrition 


Sectionab 


South  Islands 


Central  Islands,  or  Chincha 
Islands. 

NoBTH  Islands,  or  Lobos 
Islands. 


Eitimated  Quantities  of  Peruvian 
Islandaw 
rChipana      . 
I  Huanillos 
.  -  Punta  de  Lobos  . 
Peballon  de  Pica     . 
Puerto  Ingles     . 
f  North  Island   . 
-  Middle  do. 
South    do. 
'Lobos  de  Tierra 
^  Lobos  de  Afuera 
j  Guanape     . 
tFerrol     .        .        .        . 


Guano. 

Deposits  In  Tons.  Tonn 

.     iJ80,609  ■ 
.      1,612,606 

.  1,460,790  }.     '7,621,40'7 
.      2,976,050 

.  l,292,610j 
.      7,600,000* 

.  6,460,000  f    18,250,000 
.      4,200,000  J 
476,858'^ 


265,718 
70,810 
30,700 


854,086 


Twelve  Islands,        Total    27,024,493 
me^tLiTK^^^rfrW  1^!^  ^'^"^  '""^  ^^^^  ^"^-°'  ^-^-^  ^o  the  ParUa- 
]^A  l^'ilV'''^  ^^^^  78,567  tons 

.        .       ^^^  61,055  1851  199.732 

shojwing  an  enormous  progressive  increase. 

i;  Jl"?^^^?'    '^^^I  *'"/  embraces  such  of  the  primitive,  transition,  and  purer  comn«rt 
hmestones  of  secondary  formation,  as  may  be  quarried  in  silid  block*;  wh  W  fi     ^^^^^ 
are  susceptible  of  a  fine  polished  surface.'  The  finf the  ^hLof'^^re^^^^^ 
gated  the  colors  of  the  stone,  the  more  valuable,  ceteris  paribus,  is  t^e  mSe      L^Jn" 
cral  characters  are  the  following  :—  J'         'y  ">  me  marble.     Its  gen- 

Marble  effervesces  with  acids ;  affords  quicklime  by  calcination  •  ha*  »  *.«r,.i,«-^  i 
scaly  fracture ;  is  translucent  only  on  the  very  ed^es ;  is  ea^Ty  cratched  hv  Zt'^ 
has  a  spec  grav.  of  2-7;  admits  of  being  sawn  into  slibs,  and  rece  vis  a  bri,^iim  nolllh* 
TTiese  qualities  occur  united  in  only  three  principal  varieties  of  limestone  fnlr 
charoid  limestone,  so  called  from  its  fine  granular  texture  rein^blinrth^^^^^  o.l'.Z' 
and  which  constitutes  modem  statuary  marble,  like  that  of  Carrara  -9  t  hlf^v^^ 
limestone,  consisting  of  a  multitude  of  small  facets  formS  of  mt7e  Sates*  apd^d  to' l'^ 
another  m  every  possible  direction,  constituting  the  antique  statu^  ma/ble'']^^^^ 


MARBLE. 


131 


Paros ;  3.  in  many  of  the  transition  and  carboniferous,  or  encriniiic  limestones,  subordi. 
uate  to  the  coal  formation. 

The  saccharoid  and  lamellar,  or  statuary  marbles,  belong  entirely  to  primitive  and 
transition  districts.  The  greater  part  of  the  close-grained  colored  marbles  belong  also 
lo  the  same  geological  localities ;  and  become  so  rare  in  the  secondary  limestone  for- 
mations,  that  immense  tracts  of  these  occur  without  a  single  bed  sufficiently  entire 
and  compact  to  constitute  a  workable  marble.  The  limestone  lying  between  the 
calcareo-silicious  sands  and  gritstone  of  the  under  oolite,  and  which  is  called  Forest 
marble  in  England,  being  susceptible  of  a  tolerable  polish,  and  variegated  with  imbedded 
shells,  has  sometimes  been  worked  into  ornamental  slabs  in  Oxfordshire,  where  il 
occurs  in  the  neighborhood  of  Whichwood  forest;  but  this  case  can  hardly  be  con- 
sidered as  an  exception  to  the  general  rule.  To  constitute  a  profitable  marble-quarry, 
there  must  be  a  large  extent  of  homogeneous  limestone,  and  a  facility  of  transporting 
the  blocks  after  they  are  dug.  On  examining  these  natural  advantages  of  the  beds  of 
Carrara  marble,  we  may  readily  understand  how  the  statuary  marbles  discovered  in  the 
Pyrenees,  Savoy,  Corsica,  &c.  have  never  been  able  to  come  into  competition  with  it  in 
the  market.  In  fact,  the  two  sides  of  the  valley  of  Carrara  may  be  regarded  as  moun- 
tains of  statuary  marble  of  the  finest  quality. 

Gypseous  alabaster  may  be  readily  distinguished  from  marbles,  because  it  does  not 
effervesce  with  acids,  and  is  soft  enough  to  be  scratched  by  the  nail ;  stalagmitic  alabaster 
is  somewhat  harder  than  marble,  translucent,  and  variegated  with  regular  stripes  or  undu- 
lations. 

Some  granular  marbles  are  flexible  in  thin  slabs,  or,  at  least,  become  so  by  being  dried 
at  the  fire  ;  which  shows,  as  Dolomieu  suspected,  that  this  properly  arises  from  a  diminu- 
tion  of  the  attractive  force  among  the  particles,  by  the  loss  of  the  moisture. 

The  various  tints  of  ornamental  marbles  generally  proceed  from  oxydes  of  iron  ;  but 
the  blue  and  green  tints  are  sometimes  caused  by  minute  particles  of  hornblende,  as  in 
the  slate-blue  variety  called  Turchino,  and  in  some  green  marbles  of  Germany.  The 
black  marbles  are  colored  by  charcoal,  mixed  occasionally  with  sulphur  and  bitumen ; 
when  they  constitute  stinkstone. 

Brard  divides  marbles,  according  to  their  localities,  into  classes,  each  of  which  contains 
eight  subdivisions : — 

1.  Uni-colored  marbles ;  including  only  the  white  and  the  black. 

2.  Variegated  marbles  ;  those  with  irregular  spots  or  veins. 

3.  Madreporic  marbles,  presenting  animal  remains  in  the  shape  of  white  or  gray  spoih, 
with  regularly  disposed  dots  and  stars  in  the  centre. 

4.  Shell  marbles ;  with  only  a  few  shells  interspersed  in  the  calcareous  base. 

5.  Lumachella  marbles,  entirely  composed  of  shells. 

6.  Cipolin  marbles,  containing  veins  of  greenish  talc. 

7.  Breccia  marbles,  formed  of  a  number  of  angular  fragments  of  different  marbles, 
united  by  a  common  cement. 

8.  Puddingstone  marbles ;  a  conglomerate  of  rounded  pieces. 

Jntiqne  marbles. — The  most  remarkable  of  these  are  the  following  : — Parian  marble, 
called  lychnitcs  by  the  ancients,  because  its  quarries  were  worked  by  lamps ;  it  has  a  yel- 
lowish-white color;  and  a  texture  composed  of  fine  shining  scales,  lying  in  all  diiections. 
The  celebrated  Arundelian  tables  at  Oxford  consist  of  Parian  marble,  as  well  as  the 
Medicean  Venus.  Pentelic  marble,  from  Mount  Penteles,  near  Athens,  resembles  the 
Parian,  but  is  somewhat  denser  and  finer  grained,  with  occasional  greenish  zones,  pro- 
duced by  greenish  talc,  whence  it  is  called  by  the  Italians  Cipolino  statuario.  The 
Parthenon,  Propyleum,  the  Hippodrome,  and  other  principal  monuments  of  Athens, 
were  of  Pentelic  marble ;  of  which  fine  specimens  may  be  seen  among  the  Elgin  col- 
lection, in  the  British  Museum.  Marmo  Greco,  or  Greek  white  marble,  is  of  a  very 
lively  snow  white  color,  rather  harder  than  the  preceding,  and  susceptible  of  a  very  fine 
polish.  It  was  obtained  from  several  islands  of  the  Archipelago,  as  Scio,  Samos,  Lesbos, 
&c.  Translucent  white  marble,  Marmo  statuario  of  the  Italians,  is  very  much  like  the 
Parian,  only  not  so  opaque.  Columns  and  altars  of  this  marble  exist  in  Venice,  and 
several  towns  of  Lombardy ;  but  the  quarries  are  quite  unknown.  Flexible  white  marble, 
of  which  five  or  six  tables  are  preserved  in  the  house  of  Prince  Borghese,  at  Rome.  Tht 
xvhite  marble  of  Luni,  on  the  coast  of  Tuscany,  was  preferred  by  the  Greek  sculptors  to 
both  the  Parian  and  Pentelic.  White  marble  of  Carrara,  between  Specia  and  Lucca,  is 
of  a  fine  white  color,  but  often  traversed  by  gray  veins,  so  that  it  is  difficult  to  procure 
moderately  large  pieces  free  from  them.  It  is  not  so  apt  to  turn  yellow  as  the  Parian 
marble.  This  quaiTy  was  worked  by  the  ancients,  having  been  opened  in  the  time  of 
Julius  CsBsar.  Many  antique  statues  remain  of  this  marble.  Its  two  principal  quarries 
at  the  present  day  are  those  of  Pianello  and  Polvazzo.  In  the  centre  of  its  blocks  very 
Mmpid  rock-crystals  are  sometimes  found,  which  are  called  Carrara  diamonds.  As  the 
finest  qualities  are  becoming  excessively  rare,  it  has  risen  in  price  to  about  3  guineas  the 


122 


MARBLE. 


wbic  foot.  The  White  marble  of  Mount  Hymettus,  in  Greece,  was  not  of  a  very  nure 
Tf  Ims  mirbTe  '  "  '  *'  ^"''-  '^^  ^^"^"'  ^'^  ^^^^^^^^>  ^"  »»^^  ^^-"'^  M«s7u,S"S 
^tocfe  flnh>.  marble,  the  i^ero  a«/ico  of  the  Italians.  This  is  more  intensely  black 
than  any  of  our  modem  marbles;  it  is  extremely  scarce,  occurring  only  in  sculp*n4d 
frti    J?r^'^::^'^^*r«'*'«»^OT'«mof  theancients,and  /?a,«, a\/ W the  Jl^fans 

very  mlnte  wS?e  d^^^^^  a^'T^''°^""'  ^"^^^J.  interspersed  with  white  veins  and  S 
very  minute  white  dots,  as  if  strewed  over  with  grains  of  sand.      There  i«.  in  the  Gri 
mam  palace  at  Venice,  a  colossal  statue  of  MarcSs  A^rippa  in  rosso  a^i^  wh kh  wm 
formerly  preserved  in  the  Pantheon  at  Rome.      Green  antique  marble^trdi  T/  co  Z^ 
kind  of  breccia,  whose  paste  is  a  mixture  of  talc  and  limestone,  whik  ThfdTrWr^n 
fragments  consist  of  serpentine.     Very  beautiful  specimens  of  it  ire  preserved  at  Pa^ 
The  best  quality  has  a  grass-green  paste,  with  black  spots  of  noble  serpentfne  b^' 
^ITJf '''•1''^  '^' u  '^.  '^'^'     ^'^  'P'^^'^  ^^"^  «"^^>«  ^rble,  has  a  dark^gJee^^^^ 
m^^l^      T^.T"  '^  1"^-  ^l^^H.^P^'^'^'^^  fragments  of  .rZ/rocAi  changSfntow^^^ 
Twh  VK  .K       k««^«  only  la  small  tablets.      Leek  marble ;  a  rare  variet/of  tha^X! 
of  which  there  is  a  table  m  the  Mint  at  Paris.     Marmo  verde  pagliocco  is  of  a  yellowish 

aeep  red,  with  numerous  gray  and  while  veins,  is  said  to  be  found  in  Africa  and  highly 

the'vSk  o^arr"' -f;  ^'"r  ""'*'^"'  r.^'*^  ^'"^^  «"'^'^^  «^  '^'  I^«»^n« ;  eolor^  of 
tiie  yolk  of  an  egg,  either  uniform  or  marked  with  black  or  deep  yellow  rin^s       It  i. 

^ok^thr^-  ^  'f^^^'"^  by  Sienna  marble.  Bed  and  while  antique  marbles,  found  only 
among  the  ruins  of  ancient  Rome.  Grand  antiqne,  a  breccia  marble,  containinff  shell/ 
consists  of  large  fragments  of  a  black  marble,  traversed  by  veins  or'  linesTf  a  shin  ie 

Cipohn  IS  a  name  given  to  all  such  marbles  as  have  greenish  zones  produced  by^reen 
tolc ;  their  fracture  is  granular  and  shining,  and  displays  here  and  there  plates  of ^alc 
Purple  antique  breccia  marble,  is  very  variable  in   the  color  and   size  of  its  s^s* 
^<W«e  ^/ncan  breccia  has  a  black  ground,  variegated  ^vith  large  fragments  of  a  gd 
Rn7^'''  f^^  ,"''^'  ^f  P"rPli«l»  ^'ne  ^oloT ;  and  is  one  of  the  most  l^auUful  mar1,?es 
Thtrt  ""''^"^  K^'"?-    ^'^^^  ''   ^^^y  ^*^^^*^^»  «<^«»"in?  only  in  small  tablets 

^odem  marbles.--l.   British.      Black  marble   is  found   at  Ashford,   Matlock    and 
Monsaldale  m  Derbyshire  ;  black  and  white  in  the  north  part  of  Devonshire    the  van> 
gated  marbles  of  Devonshire  are  generaUy  reddish,  brownish,  mdl^^hh   variouX* 

thpPW^     fK^""*  Babbacombe,  display  a  great  variety  in  the  mixture  of 'their  ^Xrs" 
^^l^J^'^?:^\V'^'^^^ '?  ^^^^^r  ash^olored  with  black  veins,  or  blackish-gray  and  XV 
n?Hr'^  ^'I^'k  rT'  '^^-  """"^  "^"  Marychurch  exhibit  marble  qua^^s  noTonly' 
of  grea    extent,  but  of  superior  beauty  to  any  other  iK  Devonshire,  bein-  either  of  a 
dove-colored  ground  with  reddish-purple  and  yellow  veins,  or  of  a  ilack  gJouni  motUed 
with  purplish  globules.      The  green  marble  of  Anglesea  is  not  unlike  the  t"rrfc  Zhco- 
Its  colors  being  greenish-black,   leek-green,  and  sometimes  duU  XpHsh    irreffulari; 
blended  with  white.      The  white  part  is  limestone,  the  green  shS  pVoceS  from 
serpenune  and  asbestos.     There  are  several  fine  varieties  of  mayetf  De^byshke     tl^ 
r«     r  iT^L"  '^'  "«»?bborhood  of  Moneyash,  the  light  gray  being  rendered  ext^^^^^^^ 
beautiful  by  the  number  of  purple  veins  which  spread  upon'its  polished  surface  in  ek"am 
^n^Z  r^"'^'''  ^"*J/'  ""^''^  ^'•"^"^^"^  ^«  '^^  "^"Ititude  of  entrochi,  wkh  whkh  thU 
s^ne  of  wZ'  ""T  w'^^"  ^^""l^-.     ^"^'^  "^  '^'  ^^«»^'^i«"  «"d  carboniferous  lime 
Garbles  Westmoreland  is  capable  of  being  worked  up  into  agreeable  S 

A^L^t'^^^^^c  "I'u*  particularly  fine  variety  of  white  marble  is  found  in  immense  beds  at 

~ible  o"f  n'« '"^'^•• 'k      ^  **'""*^^"^  ^'^-^'^y  "^^^"^  «^  ^  ^^^  uniform  gra^';„^d 
.  ^"'^^P^.^^  of  ^  fine  polish,  occurs  on  the  north  side  of  the  ferry  of  Ballachulish  in  In 

t1  ee  onfAr  .^^'u^A'  ^««^^^"tiful  varieties  is  that  from  the  hill  of  Shtr  ch  ?n 
Ih^t'      .u^.  ^)^  Hebrides.      Its  colors  are  pale  blood-red,  light  flesh-red  and  reddish 
white,  with  dark  green  particles  of  hornblende,  or  rather  sahlite  ditfusJd'  thrn.y^Tl 

X'l^' M-    '^^^  '^"'"P^^^  "^^^^«  «f  I-^  i«  of  -  fi"*^  grL,  a  iull  whUe  coloMme 
what  resembling  pure  compact  feldspar.     It  is  said  by  Boumon   to  consist  of  anTnZ^f: 

sTts"''  The rt'^r'*  '^f!^'^"'^  "^  '^'^  ^«"^^- '^  ^'^'^  yeliowirrgreenrs "^^^^^^ 
spots.      The  carboniferous  limestone  of  manv  of  the  coal  basins  in  the  lowirnrJrof  w 

Tn  n  ""',  Tr^^i^'"  "  ''^''^'''y  ^^  ^"^»«  ft>^  chimneT-pfeces  ^  "'  ^"'* 

m  Ireland,  the  Kilkenny  marble  is  the  one  best  known  hnv:»„  „  ki    i  j 

less  varied  with  white  marks  produced  by  petrifactions       The^snar  whil"""**  ""'''♦u' 
place  of  the  shells,  sometimes  assumes  a  greenLh  vellow  Llnr^    a  «^<:"Pf«  the 

black  marble  has  al'sobeen  raised  at  CmylLfh  in^he  coi^^^^^  of  Down      A^r^nf  ^^  k"** 
«  the  county  of  Tipperary,  a  fine  pur/le  marb^^'LTuTw^Twhen'^^^^^^ 


MARBLE. 


123 


rery  beautiful.     The  county  o.  Kerry  affords  several  variegated  marbles,  not  unlike  the 

Kilkenny.  •    j  u    n    -j 

France  possesses  a  great  many  marble  quarries  which  have  been  described  by  Bmrd, 
ond  of  which  a  copious  abstract  is  given  under  the  article  marble — Rees^  Cyclopedia. 

The  territory  of  Genoa  furnishes  several  beautiful  varieties  of  marble,  the  most  re- 
markable of  which  is  the  potzevera  di  Gerum,  called  in  French  the  vert  d'Egypte  and  vert 
de  mer.  It  is  a  mixture  of  granular  limestone  with  a  talcose  and  serpentine  substance 
disposed  in  veins ;  and  it  is  sometimes  mixed  with  a  reddish  body.  This  marble  was  for- 
merly much  employed  in  Italy,  France,  and  England,  for  chimney-pieces,  but  its  sombre 
appearance  has  put  it  out  of  fashion. 

Corsica  possesses  a  good  statuary  marble  of  a  fine  close  grain,  and  pure  milky  white- 
ness, quarried  at  Ornofrio ;  it  will  bear  comparison  with  that  of  Carrara ;  also  a  gray 
marble  (bardiglio),  a  cipolin,  and  some  other  varieties.  The  island  of  Elba  has  immense 
quarries  of  a  white  marble  with  blackish-green  veins. 

Among  the  innumerable  varieties  of  Italian  marbles,  the  following  deserve  especial 
notice. 

The  rovigio,  a  white  marble  found  at  Padua;  the  white  marble  of  St.  Jnlien,  at  Pisa, 
of  which  the  cathedral  and  celebrated  slanting  tower  are  built ;  the  Biancone  marble, 
white  with  a  tinge  of  gray,  quarried  at  Magurega  for  altars  and  tombs.  Near  Mergozza 
the  white  saline  marble  with  gray  veins  is  found ;  with  which  the  cathedral  of  Milan  is 
built.  The  black  marble  of  Bergamo  is  called  paragone,  from  its  black  color,  like  touch- 
stone ;  it  has  a  pure  intense  tint,  and  is  susceptible  of  a  fine  polish.  The  pure  black 
marble  of  Como  is  also  much  esteemed.  The  polveroso  of  Pistoya,  is  a  black  marble 
sprinkled  with  dots ;  and  the  beautiful  white  marble  with  bkick  spots,  from  the  Lago 
Maggiore,  has  been  employed  for  decorating  the  interior  of  many  churches  in  the  Milanese. 
The  Margorre  marble  found  in  several  parts  of  the  Milanese,  is  bluish  veined  with  brown, 
and  composes  part  of  the  dome  of  the  cathedral  of  Milan.  The  green  marble  of  Florence 
owes  its  color  to  a  copious  admixture  of  steatite.  Another  green  marble,  called  verde  di 
PradOy  occurs  in  Tuscany,  near  the  little  town  of  Prado.  It  is  marked  with  spots  of  a 
deeper  green  than  the  rest,  passing  even  into  blackish-blue.  The  beautiful  Sienna 
marble,  or  brocatello  di  Siena,  has  a  yellow  color  like  the  yolk  of  an  egg,  which  is  dis- 
posed in  large  irregular  spots,  surrounded  with  veins  of  bluish-red,  passing  sometimes 
into  purple.  At  Montarenti,  two  leagues  from  Sienna,  another  yellow  marble  is  met 
with,  which  is  traversed  by  black  and  purplish-black  veins.  The  Brema  marble  is  yellow 
with  white  spots.  The  mandelato  of  the  Italians  is  a  light  red  marble  with  yellowish- 
white  spots,  found  at  Luggezzana,  in  the  Veronese.  The  red  marble  of  Verona  is  of  a 
red  rather  inclining  to  yellow  or  hyacinth  ;  a  second  variety  of  a  dark  red,  composes  the 
vast  amphitheatre  of  Verona.  Another  marble  is  found  near  Verona,  with  large  while 
spots  in  a  reddish  and  greenish  paste.  Very  fine  columns  have  been  made  of  it.  The 
occhio  di  pavone  is  an  Italian  shell  marble,  in  which  the  shells  form  large  orbicular  spots, 
red,  white,  and  bluish.  A  madreporic  marble  known  under  the  name  of  pielra  slellaria, 
much  employed  in  Italy,  is  entirely  composed  of  star  madrepores,  converted  into  a  gray 
and  white  substance,  and  is  susceptible  of  an  excellent  polish.  The  village  of  Bretonico, 
m  the  Veronese,  furnishes  a  splendid  breccia  marble,  comiwosed  of  yellow,  steel-gray,  and 
rose-colored  spots.  That  of  Bergamo  consists  of  black  and  gray  fragments  in  a  greenish 
cement.  Florence  marble,  called  also  ruin  and  landscape  marble,  is  an  indurated  calca- 
reous marl. 

Sicily  abounds  in  marbles,  the  most  valuable  of  which  is  that  called  by  the  English 
stone-cutters,  Sicilian  jasper ;  it  is  red  with  large  stripes  like  ribands,  white,  red,  and 
sometimes  green,  which  run  zigzag  with  pretty  acute  angles. 

Among  the  Genoese  marbles  we  may  notice  the  highly  esteemed  variety  called  portor, 
on  account  of  the  brilliant  yellow  veins  in  a  deep  black  ground.  The  most  beautiful 
kind  comes  from  Porto-Venese,  and  Louis  XIV.  caused  a  great  deal  of  it  to  be  worked  up 
for  the  decoration  of  Versailles.     It  costs  now  two  pounds  per  cubic  foot. 

Of  cutting  and  polishing  marble. — The  marble  saw  is  a  thin  plate  of  soft  iron,  continu- 
ally supplied  during  its  sawing  motion,  with  water  and  the  sharpest  sand.  The  sawing 
of  moderate  pieces  is  performed  by  hand,  but  that  of  large  slabs  is  most  economically 
done  by  a  proper  mill. 

The  first  substance  used  in  the  polishing  process  is  the  sharpest  sand,  which  must  be 
worked  with  till  the  surface  becomes  perfectly  flat.  Then  a  second,  and  even  a  third 
sand  of  increasing  fineness  is  to  be  applied.  The  next  substance  is  emery  of  progressive 
degrees  of  fineness,  after  which  tripoli  is  employed ;  and  the  last  polish  is  given  with 
tin-putty.  The  body  with  which  the  sand  is  rubbed  upon  the  marble,  is  usually  a  plate 
of  iron  ;  but  for  the  subsequent  process,  a  plate  of  lead  is  used  with  fine  sand  and  emery. 
The  polishing  rubbers  are  coarse  linen  cloths,  or  bagging,  wedged  tight  into  an  iron 
planing  tool.  In  every  step  of  the  operation,  a  constant  trickling  supply  of  water  is 
required.  / 


'y 


11 


124 


MATCHES. 


Visitors  of  Derby  may  have  an  opportunity  of  inspecting  Brown's  extensive  ma- 
chinery  for  cutting  marble  into  many  ornamental  forms,  which  has  been  well  described 
in  Rees^s  Cyclopaedia. 

Sir  James  Jelf  patented,  in  1822,  a  combination  of  machinery  for  cutting  any  de- 
scription of  parallel  mouldings  upon  marble  slabs,  for  ornamental  purposes ;  in  which 
tools,  supplied  with  sand  and  water,  are  made  to  traverse  to  and  no. 

Mr.  Tullock  obtained  a  paten t^  in  1824,  for  improvements  in  machinery  for  sawing 
and  groovmg  marble;  the  power  being  applied  by  means  of  toothed  wheels  bearing 
cranks,  which  gave  the  see-saw  motion  to  the  cutting  iron  plates. 

In  November,  1829,  Mr.  Gibbs  secured,  by  patent,  an  invention  for  working  orna- 
mental devices  in  marble,  by  means  of  a  travelling  drill,  guided  by  a  mould  of  wood. 
Ac.,  in  counter  relief;  and  in  April,  1833,  Mr.  G.  W.  Wilds  obtained  a  patent  for  ma^ 
chinery,  which  consists  of  a  series  of  circular  cutters,  for  separating  slabs  from  a  block 
of  marble;  the  block  being  advanced  slowly  to  meet  the  cutters,  by  the  progressive 
movenaent  of  a  platform  upon  wheels,  driven  by  the  agency  of  a  rack  and  pinion,  as  in 
the  cylinder  boring  machine  of  the  steam^ngine  manufacturer.  Sand  and  water  must 
be  supplied,  of  course,  from  a  hopper,  to  these  smooth-cutting  discs  of  iron  or  copper. 
See  Glass-Cutting.  He  proposes  also  to  mould  and  polish  marble,  by  applying  a 
rotatory  wheel  or  cylinder  of  anj  shape  to  it,  in  its  carrying  frame. 

^^5S^^'^^  ^®  *  variety  of  iron  pyrites,  containing  generally  a  little  arsenic. 

MARGARATES,  are  saline  compounds  of  mai^aric  acid  with  the  bases. 

MARGARIC  ACID,  is  one  of  the  acid  fats,  produced  by  saponifying  tallow  with 
alkaline  matter,  and  decomposing  the  soap  with  dilute  acid.  The  term  Marearic  sic- 
nifies  PEARLY-looking.  ° 

The  physical  properties  of  the  margaiic  and  stearic  acids  are  very  similar;  the  chief 
diflFerence  is  that  the  former  is  more  fusible,  melting  at  140°  F.  The  readiest  mode  of 
obtaining  pure  margane  acid,  is  to  dissolve  olive  oil  soap  in  water,  to  pour  into  the 
solution  a  solution  of  neutral  acetate  of  lead,  to  wash  and  dry  the  precipitate,  and  then 
to  remove  its  oleate  of  lead  by  ether,  which  does  not  affect  its  margarate  of  lead.  The 
residuum  being  decomposed  by  boiling  hot  muriatic  acitl,  affords  margaric  acid.  When 
heated  m  a  retort  this  acid  boils.  It  is  insoluble  in  water,  very  soluble  in  alcohol  and 
ether ;  it  reddens  litmus  paper,  and  decomposes,  with  the  aid  of  heat,  the  carbonates 
of  soda  and  potash. 

MARGARIC  ACID  is  obtained  most  easily  by  the  distillation  of  stearic  acid.  The 
humidity  at  the  beginning  of  the  process  must  be  expelled  by  a  smart  heat,  otherwise 
explosive  ebullitions  are  apt  to  occur.  Whenever  the  ebullition  becomes  uniform  the 
fire  IS  to  be  moderated.  ' 

MARIXE  ACID.     See  Muriatic  Acid  and  Hydbochloric  Acid. 

MARINE  SALT.     See  Salt. 

MARL  {Mariie,  Fr. ;   Mergel,  Germ.),  is  a  mixed  earthy  substance,  consisting  of 
carbonate  of  lime,  clay,  and  siliceous  sand,  in  very  variable  proportions ;  it  is  some- 
times compact^  sometimes  pulverulent     According  to  the  predominance  of  one  or 
other  of  these  three  main  ingredients,  marls  may  be  distributed  into  calcareous,  clavey 
and  sandy.     See  Limestone.  ^  ^* 

MARQUETRY,  is  a  peculiar  kind  of  cabinetwork,  in  which  the  surface  of  wood  is 
ornamented  with  mlaid  pieces  of  various  colors  and  forms.  The  marqueteur  puts  gold 
silver,  copper,  tortoise-shell,  mother-of-pearl,  ivory,  horn,  Ac,  under  contribution' 
These  substances  being  reduced  to  laminae  of  proper  thinness,  are  cut  out  into  the 
desired  forms  by  punches,  which  produce  at  once  the  full  pattern  or  mould,  and  the 
empty  one,  which  enclosed  it ;  and  both  serve  their  separate  purposes  in  marquetry. 
For  the  methods  of  dyeing  the  woods,  Ac,  see  Ivory. 

MARTIAL,  signifies  belonging  to  iron;  from  Mars,  the  mythological  name  of  this 
metaL 

MASSICOT,  is  the  yellow  oxide  of  lead. 

MASTIC  (Eng.  and  Fr. ;  Masiix,  Germ.),  is  a  resin  produced  by  making  incisions  in 
the  Pistacia  Lentiscus,  a  tree  cultivated  in  the  Levant,  and  chiefly  in  the  island  of 
Chios.  It  comes  to  us  in  vellow,  brittle,  transparent,  rounded  tears;  which  soften 
between  the  teeth ;  with  bitterish  taste  and  aromatic  smell,  and  a  specific  gravity  of 
1-OY.  Mastic  consists  of  two  resins ;  one  soluble  in  dilute  alcohol ;  but  both  dissolve 
in  strong  alcohol.  Its  solution  in  spirit  of  wine  constitutes  a  good  varnish.  It  dis- 
solves also  in  oil  of  turpentine.     See  Varnish. 

MATCH^,  chemical  Put  40  grains  of  phosphorus  into  a  wide-mouthed 
bottle.  Add  enough  oil  of  turpentine  to  cover  the  phosphorus ;  then  mix  in  10  grs.  of 
flower  of  sulphur.  Put  the  bottle  into  hot  water  until  the  phosphorus  is  entirely  dis- 
solved ;  stop  the  mouth  of  the  bottle  with  a  cork,  and  well  shake  the  whole  until  it 
lias  become  cold ;  afterwards  pour  off  the  supernatant  oil  of  turpentine.  Into  the 
mixture  of  phosphorus  which  remains  in  the  bottle  dip  the  extremities  of  the  matches, 
and,  after  some  time,  when  they  have  become  a  little  dried,  dip  them  agaiu  into  the 
following  mixture* 


matches. 


1S5 


Dissolve  30  grains  of  gum  arable  in  a  small  quantity  of  water;  add  to  it  20  grs.  of 
ehlorate  of  potash,  and  mix  them  intimately  together ;  then  again  add  It)  grs.  of  soot 
previously  mixed  with  a  few  drops  of  spirits  of  wine. 

In  about  12  hours  the  matches  will  be  perfectly  dry,  when  they  will  ignite  on  rub- 
bing them  over  a  rough  surface. 

matches,  INSTAN  TANEOUS  light,  toithoiU  Sulphur  and  withmit  Noise.  Boett- 
cher  has  published  the  following  formula  for  the  preparation  of  chemical  matches, 
which  ignite  without  noise : — 

Take  of  Gum  Arabic         -  -  -  -  -    16  parts. 

Phosphorus  -  -  -  -  -       9    — 

Nitrate  of  potash  -  -  -  -     14    — 

Manganese  -  -  -  -  -16    — 

Mix,  so  as  to  form  a  perfectly  homogeneous  mass. 

More  recently,  this  chemist,  being  desirous  of  making  a  mass  equally  good,  but  at 
a  lower  price,  tixed  on  the  following  formula : — 

Take  of  Phosphorus          -  -  -            -  -      4  parts. 

Nitrate  of  potash  -  -            -  -    10    — 

Carpenter's  glue  -  -  -            -  -       6    — 

Minium,  or  red  ochre  -  -            -  -      5    — 

Smalt       -            -  -  --  -2    — 

The  glue  is  cut  and  soaked  in  a  little  water  for  24  hours ;  it  is  then  put  into  a 
porcelain  mortar,  previously  heated,  so  as  to  cause  its  liquefaction.  The  phosphorus 
is  then  added,  afterwards  the  nitrate  of  potash,  and  lastly  the  minium  and  smalt, 
mixing  the  ingredients  constantly  with  the  pestle,  until  a  perfectly  homogeneous  mix- 
ture is  formed  which  may  almost  be  drawn  out  in  threads. 

During  this  operation  the  temperature  must  never  be  allowed  to  rise  above  167** 
F.,  to  prevent  the  inflammation  of  the  particles  of  phosphorus. 

This  paste  may  be  applied  to  wood  prepared  for  the  purpose,  or  to  amadou  previ- 
ously dried  for  eight  or  twelve  hours.  ' 

Paper  matches  may  be  made,  which  will  afford  an  agreeable  odor  on  igniting,  by 
wetting  slips  of  pnper  on  both  sides  with  tincture  of  benzoin,  and  then  applying  a 
small  quantity  of  the  above  composition  to  their  extremities,  by  means  of  a  small 
brush.  On  rubbing  one  of  these  on  a  rough  surface,  the  mass  inflames  and  ignites  the 
paper  without  the  intervention  of  a  coating  of  sulphur. 

Matches  of  wood  may  be  made  that  will  inflame  without  sulphur,  by  slightly  car- 
bonizing the  ends  of  them,  by  placing  them  against  a  red  hot  plate  of  iron,  and  then 
dipping  them  into  melted  wax. 

M.  Diesel,  of  Ebersdorf,  pupil  of  M.  Wackenroder,  has  analyzed  an  excellent  inflam- 
mable mass,  and  found  the  following  proportions  of  ingredients  in  100  parts: — 

Phosphorus  -  -  -  -  -  -  17 

Nitrate  of  potash  -  -  -  -  -  38 

Minium        -  -  -  •  -  -  24 

Glue              -  -  -  -  -  -  21 

MATCHES,  LUCIFER.  According  to  Dr.  R.  Boettger,  in  Annalen  der  Chemie  und 
Pharmacie,  vol.  xlvii.  p.  334,  take 

Phosphorus  -  -  -  .  *  -      4  parts. 

Nitre  -  -  -  -  -  -     10     — 

Fine  glue      -  -  -  -  -  -6     — 

Red  ochre,  or  red  lead  -  -  -  -       5     — 

Smalt  -  -  -  -  -  -2     — 

Convert  the  glue  with  a  little  water  by  a  gentle  heat  into  a  smooth  jelly,  put  it  into 
a  slightly  warm  porcelain  mortar  to  liquefy ;  rub  the  phosphorus  down  through  this 
gelatine  at  a  temperature  of  about  140°  or  150°  Fahr. ;  add  the  nitre,  then  the  red 
powder,  and  lastly  the  smalt,  till  the  whole  forms  a  uniform  paste.  To  make  writing- 
paper  matches,  which  burn  with  a  bright  flame  and  diffuse  an  agreeable  odor,  moisten 
each  side  of  the  paper  with  tincture  of  benzoin,  dry  it,  cut  it  into  slips,  and  smonr  one 
of  their  ends  with  a  little  of  the  above  paste  by  means  of  a  hair  pencil.  On  rubbing 
the  said  end  after  it  is  dry  against  a  rough  surface  the  paper  will  take  fire,  without 
the  intervention  of  sulphur. 

To  form  lucifer  wood  matches,  that  act  without  sulphur,  melt  in  a  flat-bottomed, 
tin  pan  as  much  white  wax  as  will  stand  one-tenth  of  an  inch  deep;  take  a  bundle  of 
wooden  matches  free  from  resin,  rub  their  ends  against  a  red  hot  iron  plate  till  the 
wood  be  slightly  charred ;  dip  them  now  in  the  melted  wax  for  a  moment,  shake  them 
well  on  taking  them  out,  and  finally  dip  them  separately  in  the  viscid  paste.  When 
dry,  they  will  kindle  readily  by  friction. 


i'ij 


126 


MATCHES. 


For  the  rapid  manufacture  of  the  wooden  splints  for  lucifer  matches  a  natpnf  wo- 
granted  to  m.  Reuben  Partridge,  in  March,  1842.  He  employ  aTrfoVaJ^m^^^^^ 
plate,  having  a  steel  face,  strengthened  by  a  bell-metal  back  •  see  r" 887  888^  Th« 
•ue  of  the  perforations  must  depend  on  tLt  of  the  desired  splKtJhiy  must  be 
as  close  together  as  possible,  that  there  may  be  a  very  small  bknk  spacT  ^tweeu 
them  otherwise  the  pW  would  afford  too  great  resistance  to  the  p^LTof  the  l^^^ 
By  this  construction,  the  whole  area  of  the  block  of  wood  may  be  ^jmofe^sed  latTr^^ 

^^unk  Tf^'^'T'^  T"^"^^  «"/  ^^''^  '^^^^^  '^'  holes, Vhich7esl^^^^^^^^^ 
tersunk  to  favor  the  entrance  and  separation  of  the  wooden  fibres.  ^"6''"^^  ^**"" 


and  one  thick^    The  mode  orpretirisb^  fit'  ''    k''k  T^?  ^^*^'  «^^  ^^^^^^  ^^^S- 
resisting  block  or  bearin^havhiran^aDertLp^nf,^^^    ^^^^  of  the  plate  against  a  firm 

site  Tide  or  back  of  he  Dla^^ff ^.  f  ^  r  "^"'i '?  *5^  P***^'  ««"^°g  «»t  on  the  oppo- 
the  shapes  a^d  dimensrons  o^the  Wo"^  r  *  """'^i^"^'  ^^  ^'«*^"«^  «?"»*«'  agreeab^^to 
Manufacture  ;}~^s^^^l  rrs1s^TinT»^t''"y?'""'v^-  V«^  ^^"-  ^^S. 
ting  the  wood,  which  i{  done  actordt^^M  the  manufacture  of  lucifers  is  the  cut. 
hand  or  bymachinery  Thb  TwInl\hLll  '  ".'  ""^  *^'  manufactory,  either  by 
the  matchis  in  framel  is  in  itsTirnlr^^      i    .    '^I^''*  P''*'^.'"  ""^ counting  and  placing 

for„PedLtheproArX.:froXl,'^*rt"roolM^^ 

of  po  ash  I,  con.,deredan  essential  ingredient  inCLnd  bu  IT  Z°-f  ?  •  't 
Nuinburg  It  has  not  been  employed  for  a  number  of  vear^iTi  ^!  i"-''"'^''*'"'"'.''' 
n.uch  endangered  the  safety  of  the  building,  and  theS  ^f  the  3^  T"*  P™?*""'' 

property,  of  water,  and  of  Jori^ltZX^Z^ ZTrTilt  .Ir^JjSrS™ 


MEATS,  PRESERVED. 


127 


is  employed.  If  ignition  be  required  without  a  fiame,  the  quantity  of  phosphorus  is 
diminished,  or  nitrate  of  lead  is  added.  The  mixing  is  conducted  in  a  water  bath, 
and  during  this  process,  and  as  long  as  the  phosphorus  is  being  ground  or  "  mullered," 
copious  fumes  are  evolved.  The  dipping  is  performed  in  the  following  manner: — ^The 
melted  composition  is  spread  upon  aboard  covered  with  cloth  or  leather,  and  the  work- 
man dips  the  two  ends  of  the  matches  alternately  that  are  fixed  in  the  frame ;  and  as 
this  is  done  with  great  rapidity,  the  disengagement  of  fumes  is  very  considerable,  and 
the  more  liable  to  be  injurious,  as  they  are  evolved  in  a  very  concentrated  form  close 
to  the  face  of  the  workmen.  This  department  is  generally  left  to  a  single  workman  ; 
and  the  average  number  that  he  can  dip  in  an  hour,  supposing  each  frame  to  hold 
3,000  matches,  would  be  1,000,000. 

After  the  matches  have  been  dipped,  they  require  to  be  dried.  This  is  generally 
done  in  the  room  in  which  the  former  process  is  carried  on ;  and  as  a  temperature  of 
from  80°  to  90°  Fahr.  is  necessary,  the  greatest  quantity  of  fumes  is  evolved  at  thia 
stage.  When  the  matches  are  dried,  the  frames  are  removed  from  the  drying  room,  and 
the  lucifers  are  now  ready  to  be  counted  out  into  boxes.  As  this  is  done  with  great 
rapidity,  they  frequently  take  fire,  and,  although  instantly  extinguished  in  the  saw- 
dust or  the  water  which  is  at  hand,  the  occurrence  gives  rise  to  an  additional  and  fre- 
quent evolution  of  fumes. 

MATRaSS,  is  a  bottle  with  a  thin  egg-shaped  bottom,  much  used  for  digestions  ia 
chemical  researches. 

MATTE,  is  a  crude  black  copper  reduced,  but  not  refined  from  sulphur  and  other 
heterogeneous  substances. 

MEADOW  ORE,  is  concKoidal  bc^  iron  ore. 

MEATS,  PRESERVED.  The  interest  which  has  of  late  attached  to  the  subject 
of  such  meats,  warrants  us  in  bringing  under  examination  the  principles  and  practice  on 
which  this  important  branch  of  industry  is  based.  The  art  itself  is  of  modern  invention, 
and  differs  in  every  respect  from  the  old  or  common  modes  of  preserving  animal  food. 
These,  as  is  well  known,  depend  on  the  use  of  culinary  salt,  saltpetre,  sugar,  or  similar 
substances,  which,  when  in  solution,  do  not  possess  the  power  of  absorbing  oxygen  gas, 
and  therefore  cut  off  effectually  all  access  of  air  to  the  meat  they  protect  It  might  b« 
imagined  that  water  alone  would  answer  this  purpose  ;  but  the  contrary  is  the  case,  for 
pure  water  absorbs  oxygen,  and  is,  therefore,  all  the  less  adapted  for  preserving  meat,  in 
proportion  as  it  is  free  from  saline  matter,  since  it  is  then  so  much  the  more  capable  of 
combining  with  oxygen  gas.  Thus,  snow,  which  is  pure  water  crystallized,  has  a  power 
of  producing  the  panary  fermentation  when  mixed  with  flour;  and  this  it  is  able  to  do 
in  consequence  of  the  large  quantity  of  gaseous  oxygen  which  it  containsi  Similarly, 
rain  water,  and  especially  dew,  will  bring  on  the  putrefaction  of  animal  matters  much 
sooner  than  spring  wat^r  ;  and  the  vulgar  prejudice  respecting  the  effect  of  the  moon's 
raya  in  accelerating  the  corruption  of  meat,  is,  beyond  doubt,  dependent  upon  the  fact, 
that  during  clear  moonlight  nights,  there  is  always  a  large  deposition  of  dew;  and  this 
having  fallen  in  a  minutely  divided  state,  possesses  the  largest  amount  of  free  oxygen, 
which  pure  or  distilled  water  is  capable  of  absorbing  from  the  atmosphere,  and,  there- 
fore, haa  a  proportionate  power  of  decomposing,— just  as  it  also  has  of  bleaching. 

Thus  far  our  remarks  have  been  applied  solely  to  raw  or  uncooked  meats;  but  the 
practical  bearing  of  the  object  which  we  have  in  hand  really  points  to  those  which  are 
more  or  less  cooked  or  preserved.  It  is  with  reference  to  provisions  of  this  kind,  that  a 
parliamentary  inquiry  is  now  in  progress ;  and  we  cannot  do  better  than  show  the  great 
importance  of  such  a  subject  to  a  maritime  nation  like  Great  Britain,  by  stating,  that 
these  provisions,  when  sound,  are  an  absolute  preventive  of  sea-scurvy, — a  disease  said, 
on  good  authority,  to  have  destroyed  more  life,  and  to  have  done  more  damage  to  our 
navy,  than  all  the  enemies  and  tempests  which  that  navy  ever  encountered.  "We  need 
not  go  far  in  search  of  evidence  to  prove  the  fearful  havoc  caused  by  this  disease ;  for  we 
are  well  furnished  by  the  history  of  Admiral  Anson's  memorable  expedition,  to  damage 
the  interests  of  Spain  in  the  Pacific  Ocean,  by  intercepting  the  annual  treasure-ship  or 
galleon  on  her  return  to  Europe.  In  spite  of  every  thing  that  care  and  experience  could 
do,  Anson  tells  us  that  he  lost,  in  all,  fully  four-fifths  of  his  people  by  scurvy.  Of  400 
men  with  whom  the  *•  Centurion"  departed  from  England,  only  200  lived  to  reach  the  isl- 
and of  Juan  Fernandez,  and  no  more  than  8  of  these  were  capable  of  doing  duty ;  and 
but  for  a  supply  of  others  at  St  Helena,  there  would  not  have  been  strength  remain- 
ing to  carry  the  ship  to  her  anchorage.  After  describing,  in  the  most  pathetic  manner, 
the  dreadful  sufferings  of  his  crew,  and  rejoicing  at  the  improvement  caused  by  the  so- 
journ at  Juan  Fernandez,  the  writer  concludes,—"  I  therefore  shall  sum  up  the  total  of 
our  loss  since  our  departure  from  England,  the  better  to  convey  some  idea  of  our  past 
sufferings  and  our  present  strength.  We  had  buried  on  board  the  *  Centurion,'  since 
leaving  St  Helena,  292  men,  and  had  remaining  on  board  214.  This  will,  doubtless, 
appear  a  most  extraordinary  mortality ;  but  yet,  on  board  the  '  Gloucester'  (his  other 
ihip  of  war)  it  had  been  much  greater:  for,  out  of  a  much  smaller  crew  than  ©urs, 
they  had  buried  the  same  number,  and  had  only  82  remaining  alive.    It  might,"  coa^ 


128 


MEATS,  PRESERVED. 


morl  favorably  tharturjersinoi  «hi  '  /  k  ^^JP^'^^^l  otherwW.  for  she  escaped 
The  real  object  of  the  vovate  IZ^^V^^  buried  42,  and  has  now  39  remaining." 
men,  with  ihich  th^thre^  fessTleft  F^lL^Uf  ««°^°l«««/d;  though  out  of  960 

It  is  almost  superfluourto  rulHnwS    f^    ^  626  were  dead  before  tEis  time, 
to  demonstrate  tC  erearutimv  1^^^      instances  of  the  same  kind ;  though,  in  order 

^      three  other  examplelas  twffs  ^vEw  dr*''-"  '^r*"^'  ^'  '"^'^'^^^^  ^wo  Z 
'      trifling  labor  and  resDonsibin/v  1,!       ,  ^^-^  "^^u""^'  ^^  '^^''tain  quarters,  to  get  rid  of  a 
our  victualling SVaX^nis     In  oJtob?;".?  this  class  of  provisions  altogether  from 
harbor,  and,  before  Ihe  end  of  n?.K'  V^l'  ^^^  ^"^^  of  Admiral  Keppell  came  into 
lar.     In  1779,  the  channel  fleet  uXs^^^^  r"i''f  '''^?  T^  ^  '^'  ^^^P'^al  at  Has? 
tained  more  than  1,000  on  board  for  Znl  ^f^^K  ^'  '?\  ^'^^^  *^  ^^'  ^^^P^^al,  and  re- 
months  during  a  sibsequent  vpar  R  n«T      ""^  hospital  accommodation.    Within  4 
asserts,  that,  lithin  Snaee  of  ^^  v        T'S-  '^""^    ^  ^^^^"'  *"^  S"'  ^-  Hawkins 
men  had  died  of  siurvj    ^vLn  IdSr^    ^"'""T  ^«^l«<^g^  °ot  'ess  than  10,000 
a  ten  weeks'  cruise  in  Ike  Ty  of^S  ^To^  ment '''"T  f  ^.  ^-'"^^^-'^  ^^er 
gross  number  ofadmissionsinto  thf  hl^V  i  *?  .^°  ^^""^  *^^  **^  ^^^  scurvy ;  and  the 
Now  the  highest  mSirauthor?H^^^^^  ""^^  ^^'^^^'  ^^  ^^^'»  ^09  died, 

all  expressed  the  ^pr^n  th^^^^^^^^  ^^^^  «"  ^he  continent,  have 

by  thJ^  use  of  salt  p^ovTsbns    a„^^^^^^^  T'.'^^'^   ''  altogether  caused 

can  be  adduced  to  corroCaU  ?he  tnifh  .f  ^  *  ^^^^^^  «»^y  ^^^geons  and  officers 
humanity  but  also  of  «plf  Jnf  ^he  truth  of  this  view;  therefore,  not  only  motives  of 
visions  c^an  be  used   thdr  pln^^^^^  imperatively  demand  that,  wherever  unsalted  pr^ 

tire  nation.     Such  tne  the  c^asT^W^^^  ^'  ^°'^^H^  ""'  ^^  '^'  ^«'««  <>^  the^««- 

art  of  preservinAnsLked  nrntf: '    ^f^'"^^  necessary  for  us  to  inquire  how  far  the 
iainty^of  result,^XctatrcarwLrrntT-'-  ^^/^^ee  of  unSbrmity.  and  cer! 
The  first  successful  att^mnf  of  fi,*"^  their  introduction  into  the  navy. 

and  due  to  ^e  fn ventfve Xfof  M  ^ITT'Z'^ ""^^^'^^ ™^**« ''' «^ ^''^'^^ ^^^in. 

1810.  received  from  the  boarJ  of  Art^^^'^A  J^^''.  gentleman,  so  long  ago  as  the  yeai 

francs  for  his  discovery  of  a  mod!  f^       *"^  Manufactures  of  Paris  the  sum  of  1^000 

results  of  which  harbTentheTamplvKrrg  '""^"1  ""^  r^''^""''  substancesT  tk^ 

navy.     Shortly  after  thL  periodTDLrM^^^^      J  *  prolonged  experience  in  the  French 

purpose  of  taking  out  a  natent  •  tFftl^     "^"'^^  *  5?'"'  ?""*"^  ^  ^^^^^  ^"^^^^  for  the 

year  1811.    In  tLpaLnf  however  ^^  '^^  ^^  t^« 

that  the  patent-righrwL  subsrqueatlvt  .ridiculously  wide,  so  much  so, 

all  kinds  of  fruit  Seat  Tnd  v^!lli  ^  mfringed  with  impunity.     The  claims  included 

vessels.  moreTr  less  fj'eed  from  a^^    ^57^"  subjected  to  the  Action  of  heat  in  closed 

presented  in  1807  apremiumToak  ts^^^^^         '^/  Society  of  Arts  in  London  had 

without  sugar  for  hoLHr  s^a  ^fo^^"    ^",^.^I'^g^«"'  ^"^S."  *  method  of  preserving  fruit 

M.  Appert^lthe  valMity  of  Durant's  n^T^^f  1'^  T^^^^  '^  ^^.'^^^  '^'  «^°^«  ^  ^hat  of 

less  so  satUfactory  were  the  result!  If"        "?  ^a  f "'"  •  ^"?^  '"^  *1"^«^^«"-     ^everthe- 

that  the  patent  wVevLtually  n,?rVL,!S  J^^  '  n  ^"^  '^^^"^V^od.  or  mixed  provisions. 

Gamble.  L  the  sum  ofTooS^^.^^^^^^^^  l^ ^^r^"'  ^^"kinf  Hall  and 

make  any  experiment  w^fh  J         ,   impenetrable  to  air.    and  have  not  ventured^ 

difficulties  of  this  invention  ii^^.L        Gamb  e,  were  able  to  overcome  the  primary 
vessels.     Since  that  tfme  bit  littl'^lrjl'^^^^  successfully  preserved  in  tin  plat{ 

in  the  art.  thou-h  its  princinlpl  li!  f  ^^^^^^^^°'  *^f  ^^^,  improvement,  has  been  made 

From  the  res^ct^sTflX' [",  ^clt^r^^^^^^^^  ^''^''''  been  supposed! 

requisite  to  prevent  fermentation  •  hnMf  '•     ^PP^^^f  .^^f  the  absence  of  oxygen  was 
wi'Jh  fermenLblematStutut  pr^^^^^^^^^  b'  p-ent 

;reror':r^Ti^^^^^^^ 

Although,  therefore  the  excluln  If'  ^***^r''  ^^  *^^  T^"''^  ^^  *^«  fermentation. 
IS  not  the  only  meal  norl T?nd-T?h '^  ^"  ^  T^""'  -^  preventing  putrefaction,  it 
process  of  Appert  ce'Cnly  dol  nff  i  7''"'^  .t'  '''°?^''*  '"^  application.  Tlie 
provisions  he^  preservernor IrthU  n.fnt^nl  -"Pr^^^i"^  "^.l*"'^'^  ^^  ^V^^"  ^^"^  ^he 
practised,  with^uch  marC  success ^hvZ^l^^^^^  improve/ process  still 

have  had  an  opportuStrof  examini'n^^h?!;^!  ^  '^^^  ^'"^  ^/  ^*"^^^^'  ^^  C^'"'^-  We 
Gamble's  pro^ions.  anrh^vT^^iJl^/jrun^r^^^^^^^^^^^ 


MEATS,  PRESERVED. 


129 


presence  of  oxygen  gas,  even  in  cases  several  years  old.     The  quantity  is,  indeed,  much 
le«8  than  that  in  atmospheric  air,  but  its  existence  is  clear  and  undeniable.     Hence  we 
must  look  for  some  other  theory  than  that  which  refers  putrefaction  to  the  presence  of 
uncombined  oxygen,  if  we  wish  to  speculate  upon  the  modus  operandi  of  Gamble's 
method.    Appert  seems  to  have  had  a  decided  doubt  as  to  the  sufficiency  of  the  oxygen 
theory,  for  he  tells  us  that  "fire  has  a  peculiar  property,  not  only  of  changing  the 
combination  of  the  constituent  parts  of  vegetable  and  animal  productions,  but  also  of 
retarding,  for  many  years  at  least,  if  not  of  destroying  altogether,  the  natural  tendency 
of  these  same  products  to  decomposition."    And  this  opinion  is  confirmed  from  many 
startling  facts,  which  cannot  be  reconciled  to  the  supposition  that  oxygen  is  the  sole  or 
even  principal  agent  of  decomposition.    Thus  milk,  which  has  been  merely  scalded,  will 
keep  much  longer  from  the  eflFect  of  this  process,  even  though  freely  exposed  to,  or 
purposely  impregnated  with,  oxygen  gas.     All  kinds  of  meat  exhibit  a  similar  result 
Again,  very  minute  qualities  of  some  mineral  substances,  as  arsenic  and  corrosive  sub- 
limate, or  of  organic  matters,  such  as  creosote,  naphtha,  and  the  volatile  oils,  have  the 
same  action  when  applied  to  meat  or  vegetables;   and  generally  speaking,  any  thing 
which  will  coagulate  albumen  has  a  preservative  power  upon  organic  substances.    So 
that  oxygen  appears  to  exert  a  decomposing  force  only  when  one  or  other  of  the  forms 
of  soluble  albumen  is  present.    Now.  the  method  of  Appei-t.  as  improved  by  Gamble 
(for  the  firm  of  Donkin.  Hall,  and  Gamble  no  longer  exists)!  is  to  render  the  albumen 
of  the  meat  or  vegetable  insoluble,  and  therefore  scarcely,  if  at  all.  susceptible  of  the 
action  of  atmospheric  oxygen.     By  this  means  the  total  exclusion  of  air  from  the  tin 
cases  IS  rendered  unnecessary,  for  even  if  a  small  quantity  of  air  remain  in  the  case,  it 
will  exert  no  more  influence  than  happens  to  a  piece  of  coagulatad  albumen,  or  hard 
boiled  white  of  egg,  which,  as  is  well  known,  may  be  exposed  to  the  air  for  years  without 
sensible  alteration,though  in  its  uncoagulated  state  it  immediately  putrefies.      If; 
therefore,  we  were  desired  in  a  few  words  to  express  the  essential  characteristics  of 
Gamble's  process,  it  would  not  be  by  referring  to  the  exclusion  of  air,  but  to  the  tho- 
rough coagulation  of  the  albumen,  that  we  should  look  for  a  satisfactory  description. 
In  this  process  the  meat,  more  or  less  cooked,  is  placed,  with  a  quantity  of  gravy  in 
a  tin  veseel,  capable  of  being  hermetically  sealed  with  solder;    it  is  then  heated,  'for 
some  time  m  a  bath  of  muriate  of  lime,  and  the  aperture  neatly  soldered  up.     After  this 
It  IS  again  exposed  to  the  action  of  the  heated  bath  for  a  period,  which  varies  with  the 
BJze  and  nature  of  the  contente  of  the  vessels ;  and  to  prove  that  this  latter  operation  is 
really  the  most  important  of  the  whole,  it  sometimes  happens  that  cases  whith  have 
begun  to  decompose  are  opened,  resoldered,  and  again  submitted  to  the  muriate  of 
lime  bath,  with  the  most  perfect  success,  as  regards  the  ultimate  result     There  is, 
however,  no  little  difficulty  in  effecting  the  thorough  coagulation  of  albumen  by  heat^ 
when  the  quantity  of  albumen  is  small  in  proportion  to  the  water  present     A  long 
continued  and  rather  high  temperature  is  then  needed;   more  especially  if  vinegar  or 
lactic  acid  be  present  in  the  fluid,  as  these  tend  to  retain  the  albumen  in  solution  • 
much  must  therefore  depend  upon  practical  experience ;  and  it  is  not  improbable  that  a 
heat  in  the  bath  but  little  higher  than  that  of  boiling  water,  would  afford  more  uniform 
results,  than  would  be  obtained  with  a  boiling  saturated  solution  of  muriate  of  lime 
This  subject  will,  however,  be  more  fully  discussed  when  speaking  of  Goldner's  processes! 
Although  by  no  means  free  from  occasional  failures  and  certainly  requiring  im- 
provement, the  system  of  Gamble  has  in  practice  worked  well;   and  pi-ovisions  have 
been  kept  m  this  way,  for  a  period  of  more  than  twenty-six  years,  without  the  slight- 
est alteration  in  their  particular  qualities;  and  so  well  is  this  fact  known  and  appre- 
ciated by  British  naval  officers  in  general,  that  few  vessels  now  leave  our  poi-ts  with- 
out at  least  a  proper  supply  for  cabin  use.     It  was  found  by  Sir  John  Ross  that  a 
number  of  those  cases  of  these  preserved  provisions  left  for  many  years  upon  Fury 
beach  and  exposed  to  excessive  variations  of  temperature,  were,  nevertheless,  perfectly 
sound  and  wholesome  as  food  when  opened. 

Guided  probably  by  theoretical  considerations,  and  too  much  impressed  with  the 
necessity  of  excluding  ox;yrgen,  a  Mr.  Goldner,  some  few  years  ago,  adopted  the  idea 
originally  conceived  by  Sir  Humphry  Davy,  of  enclosing  cooked  provisions  in  a  com- 
plete vacuum.  For  this  purpose  the  provisions,  slightly  cooked  on  the  surface,  were 
enclosed  in  canisters,  similar  to  those  of  Gamble,  but  stronger,  and  provided  with  a 
small  opening  in  the  cover.  At  this  moment  a  slight  condensation  was  effected  by 
the  application  of  a  cold  and  damp  rag  or  sponge,  and  simultaneously  with  this  the 
small  opening  was  soldered  up.  In  theory,  nothing  could  seem  better  adapted  to  in- 
sure success;  but,  from  the  late  parliamentary  disclosures,  it  is  evident  that  the  prac- 
tical working  of  the  invention  affords  any  thin^  but  a  satisfactory  result  Nor  is  there 
much  difficulty  in  conceiving  how  this  may  arise,  as  in  the  first  place  the  application 
of  a  sudden  heat  to  non-conducting  materials  is  almost  certain  to  give  rise  to  that 
peculiar  condition  of  water  called  the  spheroidal  state,  and  by  which  the  interior  of 
Vol.  11.  9  '^ 


J 


130 


MEATS,  PRESERVED. 


the  meat  will  be  as  thoroughly  protected  from  the  effect  of  heat  as  if  no  neat  were 
apphed.  Hence,  even  though  steam  in  abundance  may  issue  from  the  small  opening 
m  the  cover,  this  is  no  proof  that  the  meat  in  the  centre  of  the  vessel  is  even  warmed  • 
and  still  less  does  it  warrant  the  supposition  that  the  soluble  albumen  is  thoronghlv 
coagulated;  and  without  which,  as  we  have  stated,  preservation  is  scarcely  possible 
But,  in  addition  to  this,  the  application  of  a  damp  rag,  in  the  way  described,  is,  of  all 
others,  that  by  which  a  portion  of  air  is  most  likely  to  be  drawn  into  the  vessel  at  the 
very  moment  when  its  total  expulsion  is  taken  for  granted ;  and  both  these  circum- 
stances are  more  liable  to  happen  with  large  than  with  small  canisters  If  however 
the  meat  has  been  but  partially  cooked,  in  consequence  of  the  water  in  it  assuming  the 
spheroidal  condition,  and,  at  the  same  time,  atmospheric  oxygen  is  included  there  can 
be  no  manner  of  doubt  that  putrefaction  will  occur,  and  run  its  course  with  the  same 
rapidity  as  if  no  process  whatever  had  been  employed  to  prevent  it  That  water  so  situ- 
ated in  the  substance  of  flesh  is  extremely  prone  to  take  on  the  form  called  spheroidal, 
needs  no  other  proof  than  that  the  human  hand  may  be  deliberately  passed  through 
molten  brass  or  iron  with  perfect  impunity,  and  without  even  sensibly  warming  the 
lingers,  as  illustrated  by  M.  Boutigny.  It  is  not,  therefore,  enough  to  expose  these 
canisters  of  provisions  to  heat,  unless  that  heat  be  so  gradually  applied  as  to  prevent 
the  assumption  of  a  spheroidal  state  by  the  watery  portion  of  the  food ;  and  we  can- 
not help  thinking  that  much  of  the  disappointment  and  loss,  consequent  upon  this  kind 
of  manufacture,  has  its  origin  in  a  want  of  attention  to  the  ^ve  circumstance. 
Where  all  power  of  circulation  is  prevented,  as  in  the  instance  of  these  semi-solid 
meats,  the  tendency  of  the  part  in  immediate  contact  with  the  source  of  heat  to  ac- 
ijuire  a  temperature  capable  of  inducing  the  spheroidal  condition,  must  be  very  great 
indeed ;  and  hence,  m  speaking  of  the  muriate  of  lime  bath,  employed  by  Gamble  we 
took  occasion  to  hint,  that  more  uniform  results  might  perhaps  be  obtained  by  a'mw- 
derate  than  by  a  high  temperature.  The  probability  is,  that  no  advantage  is  gained 
b^  exceeding  220°  Fahr. ;  and  viewing  tlie  subject  chemically,  even  this  seems  too 
liigh,  where  time  is  less  an  object  than  perfection  of  manufacture. 

It  now  remains  only  to  offer  a  few  remarks  on  the  cooking  of  animal  food  and  its 
apphcation  to  the  wants  of  humanity.     If  flesh  be  digested  for  a  short  timi  in  cold 
water  or  brine,  it  parts  with  several  of  its  most  important  constituents,  and  therefor© 
the  practice  of  large  and  repeated  washing  is  an  unwise  and  foolishly  fastidious  opera- 
tion.    Cold  water  dissolves  from  meat  its  soluble  phosphates,  its  lactic  acid,  its  krea- 
tine,  and  kreatinine,  as  well  as  its  albumen.     Without  these  constituents,  however  the 
meat  neither  is  nor  can  be  fitted  to  supply  the  muscular  wear  and  tear  of  the  human 
frame.     In  fact,  one  of  these  substances  (kreatine)  has  evidently  a  singular  connection 
with  muscular  energy,  as  it  exists  in  greatest  quantity  in  the  flesh  of  animals  mosi 
remarkable  for  muscular  power  and  activity.     To  exclude  it,  therefore,  is  to  introduce 
an  element  of  weakness  in  the  dietary  of  our  seamen,  that  cannot  fail,  in  the  long  run 
to  show  Itself;  and  hence  the  enormous  prostration  of  strength  which  accompaniei 
the  sea-scurvy ;  for  it  happens  that,  as  kreatine  is  soluble  in  brine,  but  little  of  this 
valuable  element  remains  in  the  contracted  and  solidified  mass,  known  by  the  name 
of  salt  junk,  and  employed  as  food  in  the  Navy,  upon  much  the  same  principle  as 
that  ascribed  to  alligators,  who  swallow  stones  to  appease  the  cravings  of  an  empty 
stomach.     If,  however,  there  is  an  error  in  the  commencement  of  our  Navy  Tictnal- 
ling,  there  is  still  greater  in  the  treatment  of  salt  junk  by  its  prejudiced  and  ill-in- 
formed consumers.     Having  had  its  albumen  and  other  valuable  matters  removed  by 
a  cold  solution  of  common  salt,  the  junk  is  next  deprived  of  its  gelatine  and  osmazome 
by  the  action  of  boiling  water;  and  this  gelatine,  which,  with  the  kreatine  and  lactic 
acid,  would  greatly  facilitate  the  process  of  digestion,  is  thrown  away  as  worthless  - 
and  nothing  but  a  hard  mass  of  fibrine,  scarcely,  if  at  all,  susceptible  of  assimilation 
by  the  powers  of  the  animal  economy,  remains  to  give  the  appearance  of  food  to  the 

Eroduct,  and,  as  it  were,  keep  the  word  of  promise  to  the  eye,  "  to  break  it  to  the 
ope."  The  following  quotation  from  Liebig's  Researches  on  the  Chernistru  of  Food 
may  fitly  occupy  a  place  here :  "It  is  obvious,  that  if  flesh  employed  as  food  is  again 
to  become  flesh  m  the  body— if  it  is  to  retain  the  power  of  reproducing  itself  in  its 
original  condition— none  of  the  constituents  of  raw  flesh  ought  to  be  withdrawn  from 

it  during  its  preparation  for  foo»l.     If  its  consumption  be  altered  in  any  way if  one 

of  the  constituents  which  belong  essentially  to  its  constitution  be  removed— a  corres- 
ponding variation  must  take  place  in  the  power  of  that  piece  of  flesh  to  reassume  in 
the  living  body  the  original  form  and  quality  on  which  its  properties  in  the  living  or- 
ganism depend.  It  follows  from  this,  that  boiled  flesh  when  eaten  tmthout  the  soup 
formed  in  boiling  it,  is  so  much  the  less  adapted  for  nutrition,  the  greater  the  quantity 
of  water  m  which  it  has  been  boiled,  and  the  longer  the  duration  of  the  boiling 

Under  such  circumstances,  we  cannot  wonder  that  in  spite  of  the  acknowledged  purity 
of  sea-water,  disease  to  a  large  extent  should  prevail  in  our  Navy,  and  that  when  any 
active  malady  makes  its  appearance,  the  mortality  should  greatly  exceed  that  of  the 


MELLITIC  ACID. 


131 


army  under  similar  circumstances.  This  is  a  more  natural  sequence  of  the  system  pur- 
sued with  regard  to  provisions ;  and  so  far  from  abandoning  altogether  the  emplo3'ment 
of  preserved  meats  from  the  casual  putrefaction  of  a  few  cases,  it  seems  to  us  that  a 
wise  government  would  rather  seek  to  run  all  this  inconvenience,  by  calling  in  the  aid 
of  science,  than  fall  back  into  a  supine  condition,  when  the  interest  of  the  nation  so 
loudly  calls  for  activity.  After  all,  however,  we  can  find  no  proof  that  these  preserved 
provisions  have  failed,  except  in  the  case  of  Goldner;  for  there  are  many  other  manu- 
facturers, both  in  this  country  and  in  France,  whose  productions  no  more  warrant 
the  ban  of  exclusion,  than  a  trifling  accident  deserves  to  be  deemed  a  deliberate 
crime.  If  failure  be  a  sufficient  reason  for  interdicting  further  operations,  how  shall 
we  account  for  the  persevering  assiduity  of  our  dockyard  authorities  in  respect  to 
ship-building  f  We  sincerely  hope  that  the  parliamentary  committee,  now  sitting, 
will  not  separate  until  the  whole  subject  of  preserved  provisions  has  been  fully  and 
impartially  investigated  in  all  its  details. 

MEDALS.     For  their  composition,  see  Bronze  and  Copper. 

The  Industrial  Exhibition  of  1851  has  called  into  requisition,  among  others,  the 
skilled  labor  of  ^Jie  medallist  die-sinker.  As  a  consequence,  medals  of  all  kinds  and 
prices  are  being  produced.  A  medal  die  is  thus  forrnea:— -Steel  of  an  uniform  texture 
and  kind  being  selected,  it  is  forged,  softened  by  annealing,  and  the  face  and  check  for 
the  collar  turned.  The  design  approved  o1^  the  die-sinker  proceeds  to  cut  away  those 
parts  of  the  greatest  depth  by  means  of  small  chisels:  the  more  minute  details  are 
taken  out  by  gravers,  chisel-edged,  and  gauged  steel  tools  fitted  into  wood  handles  very 
short,  and  to  fit  the  palm  of  the  hand.  As  the  work  proceeds,  proofs  are  taken  in  wax ; 
when  defective  in  form  the  cutting  is  corrected,  deficient  in  relief  it  is  sunk  deeper. 
It  will  of  course  be  borne  in  mind  that,  what  will  be  relievo  in  the  medal,  is  in- 
taglio in  the  die.  The  inscription  is  introduced  by  means  of  small  letter-punches. 
Then  follows  the  hardening  of  the  die,  a  stage  of  the  business  the  most  critical,  as  a 
defect  in  the  steel  will  at  once  be  made  apparent  thereby,  and  the  labor  of  months 
rendered  useless  in  a  few  minutes.  If  the  die  endures  this,  it  has  only  another  test,  viz., 
the  making  of  a  "  hub,"  or  copy  of  the  die  in  steel,  and  used  for  the  correction  of  the 
duplicate  copies  of  the  die.  The  danger  in  this  case  arises  from  the  want  of  uniformity 
of  hardues3.     If  irregular,  one  portion  of  the  die  must  suffer,  and  become  valueless. 

Medal-making  or  stamping  is  thus  carried  on: — ^The  press  consists  of  a  large  and 
close  threaded  screw,  to  the  top  of  which  a  large  wheel  is  attached  horizontally.  The 
bed  of  the  press  is  fitted  with  screws  to  secure  the  die  in  its  place ;  when  this  is  done 
the  collar  which  gives  the  thickness  of  the  medal  is  fitted  on,  the  die  forming  the 
reverse  of  the  medal  is  attached  to  the  screw  ;  a  blank  (a  piece  of  metal  cut  out  to 
form  the  medal)  is  then  introduced.  Motion  is  imparted  to  the  wheel,  which  operates 
on  the  screw;  a  blow  is  given,  and  if  the  impression  is  soft  and  shallow,  a  medal  is 

C reduced;  but  if  deep,  repeated  blows  are  given  to  bring  the  impression  up.  When 
ronze  or  silver  is  the  material  in  which  the  medal  is  to  be  produced,  as  many  as  20  or 
even  30  blows  are  necessary.  The  medal  is  then  taken  out  of  the  press,  the  edge 
turned,  and  the  operation  is  complete. 

By  collar  die,  is  meant  that  portion  which  gives  the  thickness  to  the  medal  or  coin 
to  be  struck.  All  medal  dies  are  of  three  parts,  viz.,  the  reverse,  obverse,  and  collar. 
The  smaller  class  of  dies  are  cut  in  steel  entirely,  the  lai^er  kinds  for  brass  foundry 
«nd  other  purposes  are  •*  laid  "  or  covered  with  steel  on  a  foundation  of  iron.  When 
indentations  occur,  the  die  is  what  is  called  "  fullered,"  or  hollowed,  and  the  steel 
follows  the  same  in  a  parallel  thickness. 

MEERSCHAUM  (Germ. ;  sea-froth,  Eng. ;  Ecume  de  Mer  Moffnesie  carbonatee  sili- 
ei/ere,  Fr.),  is  a  white  mineral,  of  a  somewhat  earthy  appearance,  always  soft,  but 
dry  to  the  touch,  and  adhering  to  the  tongue.  Specific  gravity^,  2'6  to  3*4;  affords 
water  by  calcination  ;  fuses  with  difficulty  at  the  blowpipe  into  a  white  enamel;  and 
is  acted  upon  by  acids.  It  consists,  according  to  Klaproth,  of  silica,  41  -5  ;  magnesia, 
1 8"25 ;  water  and  carbonic  acid,  39.  Other  analysts  give,  silica  60,  magnesia  25,  water 
26.  It  occurs  in  veins  or  kidney-shaped  nodules,  among  rocks  of  serpentine,  at  Egri- 
bos,  in  the  island  of  Negropont,  Eski-Schehir  in  Anatolia,  Brussa  at  the  foot  of  Mount 
Olympus,  at  Baldissero  in  Piedmont,  in  the  serpentine  veins  of  Cornwall,  Ac. 

When  first  dug  up,  it  is  soft,  greasy,  and  lathers  like  soap ;  and  is  on  that  account 
used  by  the  Tartirs  in  washing^their  linen.  The  well  known  Turkey  tobacco-pipes 
are  made  from  it,  by  a  process  analogous  to  that  for  making  pottery  ware.  The  bowls 
of  the  pipes,  when  imported  inte  Germany,  are  prepared  for  sale  by  soaking  them  first 
in  tallow,  then  in  wax,  and  finally  by  polishing  them  with  shave-grass. 

MELLITE  (Eng.  and  Fr. ;  Hontgstein,  Germ.)     See  Honeystone. 

MELLITIC  ACID,  which  is  associated  with  alumina  in  the  preceding  mineral, 
crystalliies  in  small  colorless  needles,  is  without  smell,  of  a  strongly  acid  taste,  perma^ 
nent  inthe  air,  soluble  in  water  and  alcohol,  as  also  in  boiling  hot  concentrated  sul- 
phuric acid,  but  is  decomposed  by  hot  nitric  acid,  and  consists  of  50'21  carbon,  and 


II 


132 


MERCURY. 


49*79  oxygen.  It  is  carbonized  at  a  red  heat,  without  the  production  of  any  inflammo- 
ble  oil. 

MELLON  is  a  new  compound  of  carbon  and  azote,  discovered  by  M .  Liebig,  by  heating 
bi-snlpiio-cyanide  of  mercury.  The  mellon  remains  at  the  bottom  of  the  retort  under  the 
form  of  a  yellow  powder. 

MENACHANITE,  an  ore  of  titanium,  found  in  the  bed  of  a  rivulet  which  flows  into 
the  valley  Menacan,  in  Cornwall. 

MERCURY  or  QUICKSILVER.  This  metal  is  distinguished  by  its  fluidity  at  com- 
mon temperatures ;  its  density = 13'6  ;  its  silver  blue  lustre ;  and  its  extreme  mobility.  A 
cold  of  39°  below  zero  of  Fahrenheit,  or  — 40°  Cent.,  is  required  for  its  congelation,  in 
which  state  its  density  is  increased  in  the  proportion  of  10  to  9,  or  it  becomes  of  spec 
grav.  15-0.  At  a  temperature  of  656°  F.  it  boils  and  distils  off"  in  an  elastic  vapor ;  which, 
being  condensed  by  cold,  forms  purified  mercury. 

Mercury  combines  with  great  readiness  with  certain  metals,  as  gold,  sUver,  zinc,  tin, 
and  bismuth,  forming,  in  certain  proportions,  fluid  solutions  of  these  metals.  Such  mer- 
curial alloys  are  called  amalgams.  This  property  is  extensively  employed  in  many  arts; 
as  in  extracting  gold  and  silver  from  their  ores ;  in  gilding,  plating,  making  looking-glasses, 
&c.  Humboldt  estimates  at  16,000  quintals,  of  100  lbs.  each,  the  quantity  of  mercury 
annually  employed  at  his  visit  to  America,  in  the  treatment  of  the  mines  of  New  Spain ; 
three  fourths  of  which  came  from  European  mines. 

The  mercurial  ores  may  be  divided  into  four  species : — 

1.  Native  quicksilver. — It  occurs  in  most  of  the  mines  of  the  other  mercurial  ores,  in 
the  form  of  small  drops  attached  to  the  rocks,  or  lodged  in  the  crevices  of  other  ores. 

2.  Argental  mercury^  or  native  silver  amalgam. — It  has  a  silver  white  color,  and  is 
more  or  less  soft,  according  to  the  proportion  which  the  mercury  bears  to  the  silver. 
Its  density  is  sometimes  so  high  as  14.  A  moderate  heat  dissipates  the  mercury,  and 
leaves  the  silver.  Klaproth  states  its  constituents  at  sDver  36,  and  mercury  64,  in  100 ; 
but  Cordier  makes  them  to  be,  27|  silver,  and  72|  mercury.  It  occurs  crystallized  in  a 
variety  of  forms.  It  has  been  found  in  the  territory  of  Deux-Ponts,  at  Rozenau  and 
Niderstana,  in  Hungary,  in  a  canton  of  Tyrol,  at  Sahlberg  in  Sweden,  at  Kolyvan  in 
Siberia,  and  at  Allemont  in  Dauphiny ;  in  small  quantity  at  Almaden  in  Spain,  and  at 
Idria  in  Camiola.  By  the  chemical  union  of  the  mercury  with  the  silver,  the  amalgam, 
which  should  by  calculation  have  a  spec.  grav.  of  only  12-5,  acquires  that  of  14*11,  ac- 
cording to  M.  Cordier. 

3.  StUphuret  of  mercury,  commonly  called  Cinnabar,  is  a  red  mineral  of  various 
shades ;  burning  at  the  blowpipe  with  a  blue  flame,  volatilizing  entirely  with  the  smell 
of  burning  sulphur,  and  giving  a  quicksilver  coating  to  a  plate  of  copper  held  in  the 
fumes.  Even  the  powder  of  cinnabar  rubbed  on  copper  whitens  it.  Its  density  varies 
from  6*9  to  10*2.  It  becomes  negatively  electrical  by  friction.  Analyzed  by  Klaproth, 
it  was  found  to  consist  of  mercury  84*5,  sulphur  14*75.  Its  composition,  viewed  as  a 
bisulphuret  of  mercury,  is,  mercury  86*2,  sulphur  13'8.  The  finest  crystals  of  sulphuret 
of  mercury  come  from  China,  and  Almaden  in  Spain.  These  contain,  according  to  Klap- 
roth, 85  per  cent,  of  mercury. 

A  bitumiTtous  sulphuret  of  mercury  appears  to  be  the  base  of  the  great  exploration  of 
Idria ;  it  is  of  a  dark  liver-red  hue ;  and  of  a  slaty  texture,  with  straight  or  twisted  plates. 
It  exists  in  large  masses  in  the  bituminous  schists  of  Idria.  M.  Beurard  mentions  also 
the  locality  of  Monster  Appel,  in  the  dutchy  of  Deux-Ponts,  where  the  ore  includes  im- 
pressions of  fishes,  curiously  spotted  with  cinnabar. 

The  compact  variety  of  the  Idria  ore  seems  very  complex  in  composition,  according 
to  the  following  analysis  of  Klaproth: — Mercury,  81-8;  sulphur,  13*75 ;  carbon,  2*3 ; 
silica,  0*65 ;  alumina,  0*55 ;  oxyde  of  iron,  0*20  ;  copper,  0*02 ;  water,  0*73  ;  in  100  parts. 
M.  Beurard  mentions  another  variety  from  the  Palatinate,  which  yields  a  large  quantity 
of  bitumen  by  distillation ;  and  it  was  present  in  all  the  specimens  of  these  ores  analyzed 
by  me  for  the  German  Mines  Company.  At  Idria  and  Almaden  the  snlphurets  are  ex« 
tremely  rich  in  mercury. 

4.  Muriated  mercury,  or  the  Chloride  of  mercury,  commonly  called  Horn  mercury. 
This  ore  occurs  in  very  small  crystals  of  a  pearl-gray  or  greenish-gray  color,  or  in  smzdl 
nipples  which  stud,  like  crystals,  the  cavities,  fissures,  or  geodes  among  the  ferruginous 
gangues  of  the  other  ores  of  mercury.  It  is  brittle,  and  entirely  volatile  at  the  blow-pipe, 
characters  which  distinguish  it  from  horn  silver. 

The  geological  position  of  the  mercurial  ores,  in  all  parts  of  the  world,  is  in  the  strata 
which  commence  the  series  of  secondary  formations.  Sometimes  they  are  found  in  the 
red  sandstone  above  the  coal,  as  at  Menildot,  in  the  old  dutchy  of  Deux-Ponts,  at 
Durasno  in  Mexico,  at  Cuen^a  in  New  Granada,  at  Cerros  de  Gauzan  and  Upar  in 
Peru ;  in  the  subordinate  porphyries,  as  at  Deux-Ponts,  San  Juan  de  la  Chica  in  Peru, 
and  at  Cerro-del-Fraile,  near  the  town  of  San  Felipe ;  they  occur  also  among  the  strata 
below,  or  subordinate  to  the  calcareous  formation,  called  zechttein,  in  Germany,  or 


MERCURY. 


188 


among  the  accompanying  bituminous  schists,  as  at  Idria  in  Camiola ;  and,  lastly,  they 
form  masses  in  the  zechstein  itself.  Thus,  it  appears  that  the  mercurial  deposites  arc 
confined  within  very  narrow  geological  limits,  between  the  calcareous  beds  of  zechstein, 
and  the  red  sandstone.  They  occur  at  times  in  carbonaceous  nodules,  derived  from  the 
decomposition  of  mosses  of  various  kinds ;  and  the  whole  mercurial  deposite  is  occasion- 
ally covered  with  beds  of  charcoal,  as  at  Durasno. 

They  are  even  sometimes  accompanied  with  the  remains  of  oi^anic  bodies,  such  as 
casts  of  fishes,  fossil  shells,  silicified  wood,  and  true  coal.  The  last  fact  has  been 
observed  at  Potzberg,  in  the  works  of  Drey-Koenigszug,  by  M.  Brongniart.  These 
sandstones,  bituminous  schists,  and  indurated  clays,  contain  mercury  both  in  the  state  of 
sulphuret  and  in  the  native  form.  They  are  more  or  less  penetrated  with  the  ore,  form- 
ing sometimes  numerous  beds  of  very  great  thickness ;  while,  in  the  more  ancient  or 
the  primitive  formations,  these  ores  exist  only  in  very  small  quantity  associated  with  tin. 
Mercury  is,  generally  speaking,  a  metal  sparingly  distributed  in  nature,  and  its  mines  are 

very  rare. 

The  great  exploitations  of  Idria  in  Friuli,  in  the  county  of  Goritz,  were  discovered  in 
1497,  and  the  principal  ore  mined  there  is  the  bituminous  sulphuret.  The  workings 
of  this  mine  have  been  pushed  to  the  depth  of  280  yards.  The  product  in  quicksilver 
might  easily  amount  annually  to  6000  metric  quintals=600  tons  British ;  but,  in  order  to 
uphold  the  price  of  the  metal,  the  Austrian  government  has  restricted  the  production  to 
150  tons.  The  memorable  fire  of  1803  was  most  disastrous  to  these  mines.  It  was  ex- 
tinguished only  by  drowning  all  the  underground  workings.  The  sublimed  mercury  in 
this  catastrophe  occasioned  diseases  and  nervous  tremblings  to  more  than  900  persons  in 
the  neighborhood. 

Pliny  has  recorded  two  interesting  facts :  1.  that  the  Greeks  imported  red  cinnabar 
(torn  Almaden  700  years  before  the  Christian  era ;  and  2.  that  Rome,  in  his  time,  annu- 
ally received  700,000  pounds  from  the  same  mines.  Since  1827,  they  have  produced 
22,000  cwts.  of  mercury  every  year,  with  a  corps  of  700  miners  and  200  smelters ;  and, 
indeed,  the  veins  are  so  extremely  rich,  that  though  they  have  been  worked  pretty  con- 
stantly during  so  many  centuries,  the  mines  have  hardly  reached  the  depth  of  330  yards, 
or  something  less  than  1000  feet.  The  lode  actually  under  exploration  is  from  14  to  16 
yards  thick ;  and  it  becomes  thicker  still  at  the  crossing  of  the  veins.  The  totality  of  the 
ore  is  extracted.  It  yields  in  their  smelting  works  only  10  per  cent,  upon  an  average, 
but  there  is  no  doubt,  from  the  analysis  of  the  ores,  that  nearly  one  half  of  the  quicksilver 
is  lost,  and  dispersed  in  the  air,  to  the  great  injury  of  the  workmen's  health,  in  conse- 
quence of  the  barbarous  apparatus  of  aludels  employed  in  its  sublimation  ;  an  apparatus 
which  has  remained  without  any  material  change  for  the  better  since  the  days  of  the 
Moorish  dominion  in  Spain.  M.  Le  Play,  the  eminent  Ingenieur  des  Mines,  who  published, 
in  a  recent  volume  of  the  Annales  des  Mines,  his  Itineraire  to  Almaden,  says,  that  the 
mercurial  contents  of  the  ores  are  notablemeni  plus  elevees  than  the  product. 

These  veins  extend  all  the  way  from  the  town  of  Chillon  to  Almadenejos.  Upon 
the  borders  of  the  streamlet  Balde  Azogues,  a  black  slate  is  also  mined  which  is  abun- 
dantly impregnated  with  metallic  mercury.  The  ores  are  treated  in  13  double  fur- 
naces, which  I  shall  presently  describe.  «  Le  mercure,"  says  M.  Le  Play,  «  a  sur  la 
sante  des  ouvriers  la  plus  funeste  influence,  et  P  on  ne  pent  se  defendre  d'  un  sentiment 
penible  en  voyant  V  empressement  avec  lequel  des  jeunes  gens,  pleins  de  force  et  de 
sante,  se  disputent  la  faveur  d'  aller  chercher  dans  les  mines,  des  maladies  cruelles,  et 
souvent  une  mort  prematuree.  La  population  des  mineurs  d'  Almaden  meritent  le  plus 
haut  interet.**  These  victims  of  a  deplorable  mismanagement  are  described  as  being  a 
laborious,  simple-minded,  virtuous  race  of  beings,  who  are  thus  condemned  to  breathe 
an  atmosphere  impregnated  far  and  near  with  the  fumes  of  a  volatile  poison,  which 
the  lessons  of  science,  as  I  shall  presently  demonstrate,  might  readily  repress,  with  the 
effect  of  not  only  protecting  the  health  of  the  population,  but  of  vastly  augmenting  the 
revenues  of  the  state. 

These  celebrated  mines,  near  to  which  lie  those  of  Las  Cuebas  and  of  Almadenejos, 
were  known  to  the  Romans.  After  having  been  the  property  of  the  religious  knights  of 
Calatrava,  who  had  assisted  in  expelling  the  Moors,  they  were  farmed  off'  to  the  celebrated 
Fugger  merchants  of  Augsbourg;  and  afterwards  explored  on  account  of  the  government, 
from  the  date  of  1645  till  the  present  time.  Their  produce  was,  tUl  very  lately,  entirely 
appropriated  to  the  treatment  of  the  gold  and  silver  ores  of  the  new  world. 

The  mines  of  the  Palatinate,  situated  on  the  left  bank  of  the  Rhine,  though  they  do  not 
approach  in  richness  and  importance  to  those  of  Idria  and  Almaden,  merit,  however,  all 
the  attention  of  the  government  that  farms  them  out.  They  are  numerous,  and  varied  in 
geological  position.  Those  of  Drey-Koenigszug,  at  Potzberg,  near  Kussel,  deserve  par- 
ticular notice.  The  workings  have  reached  a  depth  of  more  than  220  yards  ;  the  ore  be- 
ng  a  sandstone  strongly  impregnated  with  sulphuret  of  mercury.  The  produce  of  these 
mines  is  estimated  at  about  30  tons  per  annum. 


134 


MERCURY. 


The  mines  of  Guancavelica.  in  Peru  ar^  tlip  mr»ro  ;««« .•  ,    . 

directly  employed  in  treating  C  oZV7oiiLT7ayerZtt^\^'  '^Z'-'  ^\^'"''  ?'' 

aceo^ng  to  He,„,  about  .be  be£„iV  «/ 1^  :?al°^S^?oT  T^-r/p-S 

r  ^T\}?  ^^^  ^^^^  century,  the  method  called  per  descermiin  was  the  onlv  nn^  in  «.^ 

«nj  ici^ujjuiscu.     nence,  oeiore  IbSo.  some  smeltmo'  wnrV*  nf  iv>a  r>o,io,«: »     u  j 

up  the  method  per  desceLum,  which  was  hoover  stmrPi«!nJ^  Palatmate  had  given 
stituted  for  it  the  furnaces  caUed  ZkrUs     At  fir^'t  llh  *"  l"*'"* '  *"^  ^^^^  ^"*»- 

in  these  furnaces;  but  they  were  fot^ccee^dldty^r^^^^^         Tl^^e'ZUS^lZt 
mode  of  operating  is  still  in  use.     At  Idria,  in  the  year  1750  «  ajpj  ,^;ern  !  '* 

There  exist,  therefore,  three  kinds  of  apparatus  for  the  distillation  of  mprn„rv     i    ♦!. 
furnace  called  a  gallery;  2.  the  furnace  w^th  aZitrfL     and  ^11?^  f  '^^'^''^ '•  }'  ^f 
Idria      I  shall  describe  each  of  these  briefl^insut^^^^^^^         '*  /''  "^'"^^  '^^^«''«''"  ^^ 

1'  I' umace  called  Gallery  of  the  Palatinate. The  rnnstmrtJ^n  «f  <k-   r  •     ,. 

fig.  889,  which  presents  a  vertical  section  in  the  line  a  h  of  the  ground  plan  I  IZ    In 
the  ground  plan,  the  roof  e  e'  of  the  furnace  {fig-  889)  is  sum^sed  t^hp  iffipH  nff  • 

S'889   fprwh^'^^^'?^^^^';/  ^>^  'T  ^^'^  of^ucurbTu'pon   thelratel'/ 
y»g«.  osy,  890,  which  receives  the  pit-coal  emnloved  ns  fnoi      tt«,i«    «u-         »/«^«^   *- y > 

an  a.h.pit  d!  Fig.  891,  which   exWbits  an  elevation  ofthe  ^,l"ce   lo!n^^^ 
ash.pit,  as  well  as  one  of  the  two  doors  c,  by  which  the  full  is rroTi  S^TthTgrate 

^^^  »^«  ?/•     Openings  ..,  (j^.  889,f  are 

left  over  the  top  arch  of  the  fur- 
nace, whereby  the  draught  of  air 
may  receive  a  suitable  direction. 
The  grate  of  the  fireplace  extends 
over  the  whole  length  of  the  fur- 
nace, fig.  890,  from  the  door  c  to 
the  door  /,  situated  at  the  opposite 
extremity.  The  furnace  called  gal- 
lery includes  commonly  30  cucurbits, 
and  in  some  establishments  even 
62.  Into  each  are  introduced  from 
56  to  70  pounds  of  ore,  and  15  to 
^°  .P?"n<Js  of  quicklime,  a  mixture 
which  fills  no  more  than  two  thirds 
of  the  cucurbit;  to  the  neck  a 
stoneware  receiver  is  adapted,  con- 

The  fire,  at  "first  moderate,  is  eventuaUy  pushed  mTe  oZTw.  *^  *'*^^.  V^  ^^'-^^ 
opemtion  being  concluded,^  contents  of  tre  rece  vers  are^^^^^^^^^^^  ^''»  "  *  ?"* 

bowl  placed  upon  a  plank  above  a  bucket  •    thp  Jn^^u   1    ^J^?  ^""^  '"*°  ^  ^^**^^" 
.i.0  bowl,  and  the  watL  d™w,  o..^X^  I'^JnfS^Z'lflZ^.  ^Z^ 


MERCURY. 


135 


the  inside  of  the  receivers  is  called.  This  is  considered  to  be  a  mixture  of  sulphuret 
and  ox^'dc  of  mercury.  The  black  mercury^  taken  out  of  the  tub  and  dried,  is  distilled 
anew  with  excess  of  lime ;  after  which  the  residuum  in  the  retorts  is  thrown  away,  as 

useless. 

M%del  furnaces  of  jilmaden.—Figs.  892  and  893  represent  the  great  furnaces  with 
aludels  in  use  at  Almaden,  and  anciently  in  Idria  ;  for  between  the  two  establishments 
there  was  in  fact  littie  difference  before  the  year  1794.  Figs.  892  and  896  present  two 
vertical  sections ;  figs.  893  and  894  are  two  plans  of  two  similar  furnaces,  conjoined  in 

one  body  of  brickwork.  In  the  four 
figures  the  following  objects  are  to  be 
remarked :  a  door  a,  by  which  the  wood 
is  introduced  into  the  fire-place  b.  This 
is  perforated  with  holes  for  the  passage 
of  air ;  the  ash-pit  c  is  seen  beneath. 
An  upper  chamber,  d,  contains  the  mer- 
curial ores  distributed  upon  open  arches, 
which  form  the  perforated  sole  of 
this  chamber.  Immediately  over  these 
arches,  there  are  piled  up,  in  a  dome 
form,  large  blocks  of  a  limestone,  very 
poor  in  quicksilver  ore ;  above  these 
are  laid  blocks  of  a  smaller  size,  then 
ores  of  rather  inferior  quality,  and 
stamped  ores  mixed  with  richer  mine- 
rals. Lastly,  the  whole  is  covered  up 
with  soft  bricks,  formed  of  clay  kneaded 
with  schlich,  and  with  small  pieces  of 
sulphuret  of  mercury.  Six  ranges  of 
aludels  or  stoneware  tubes//,  of  a  pear 
shape,  luted  together  with  clay,  are 
mounted  in  front  of  each  of  the  two  fur- 
naces, on  a  double  sloping  terrace,  having 
in  its  lowest  middle  Une  two  gutters  t  », 
a  little  inclined  towards  the  intermediate  wall  m.  In  each  range  the  aludel  placed  at  the 
line  tmv  otfig,  893  that  is  to  say,  at  the  lowest  point,  g,  figs.  892,  895,  is  pierced  with 

894 


^SS^g^iZSZ 


893 


a  hole.    Thereby  the  mercury  which  had  been  volatilized  in  d,  if  it  be  already  condensed 
by  the  cooling  in  the  series  of  aludels  /g,  may  pass  into  the  corresponding  gutter,  next 

895 


into  the  hole  m,  fig.  893,  and  after  that  into  the  wooden  pipes  h  h',fig.  892,  which  con- 
duct it  across  the  masonry  of  the  terrace  into  cisterns  filled  with  water;  see  q,fig.  894, 
which  is  the  plan  of  fig.  896. 
The  portion  of  mercury  not  condensed  in  the  range  of  aludels,/  g,  which  is  the  most 


/ 


1^^ 


136 


MERCIFRY. 


n 


part  of  the  vapors  diffused  in  the  chamW  fc'?.  th^riK   ^  T*^  '^'»^^^-    The  greater 
falls  down  upon  the  two  inclined  plan^  which  form  ^^^^^  '^'  ^^'^^ 

as  vapor  passes  into  an  upper  chamber  fc'bv  a  small  ^h^'"'"-  ^^""^  "»«y  ^^^^  «ist 
of  this  chamber  there  is  a  shutter  which  m'av  be  oTphL  ^^^  "*  ^'^  ^^'^  «^  ^^e  sides 
.and  beneath  this  shutter,  therri^TLu^Jtin^^l  u^^^^^^^^^^ 
collects  Much  of  it  is  also  f^nd  condS  inle^'dels'  "t?^^  T^^^^^^'  ^^  ""^^ 
process  has  inconveniences  which  have  been  tried  to  wl;  J^.T  \^^^  P'«^^  ^^^^  this 
but  rather  unchemical  grand  apparatus  of  Idria  '"^^'^  ^^  *^^  '"^''e  extensive 

Details  of  the  aludel  apparatus  :  25  are  set  in  earh  nf  th^  lo 
constituting  300  pear-shapid  stoneware  Vessels  or^ntt^^^^^^^^^  ^^^'l  ^M^.  894. 

one  another,  and  luted  with  loam.  What  a  mXtudP  n?  •  ^  ?  '  ^^^^  merely  thrust  into 
must  be  continually  giving  wayTy  the  .hrinW  of  th5  ]T''  ''^v'^^^"**  ^  ^^^^^  "^""y 
'TisThe  Z?ofTr''\  '^'^  of  ^^^du'cMo^^^^^^^^^^^^  ^""^'^'^  ^«  -reuri^ 

^f:^^::^^s;t^  ^:^  -ti^-^  -tr.  x^t\  ''-  -  ^«  ^««^  ^^ 

the  distillation ;  //  are  vents  for  condnoHna  tKol,  ^-  %  ^**^  ^*"^^  ^^^"^  closed  dunne 

separated  by  a  trla^gnlLCd;  S^  ml^^^^  -to  two  chambeT^ 

o  o,  are  the  ranges  of  aludels/in  connS  wfth  thf  k  T^^^  chimney  of  the  lire-place; 

towards  the  gutter  g,  upon     L  doubri^^^^^  ^^ich  are  laid  slanting^ 

chamber  A  9;  this  being  surmounted  by  two  chtmSeTs'  ^  ''™'^"^^^  ^"  '^« 

these  aludels  and  in  the  basins  at  q  ald^M  m  ri.  «  th^nf''^  is.coUected  in 
between  the  two  principal  walls  of  each  of  the  furnL/  •  *i"  '*°"^  Partition  set  up 
race,  leading  to  the  plalfonn  which  surmounts  the  ?u™;.o'' ''  -^^  ''^''  ^^^^^  ^^"^^1  ter- 
away  the  rains  which  may  faU  upon  the  buSdini  ^  "" ''  *  ^""^  ^«^  conducting 

betSe^ssTr^^it-^i^ltbr^^^^^^^^^  laboratory,  it  will  not 

ores  m  large  blocks,  fragments,  or  sh/vlrs  Sfsi^e  vfrl^^^  ''^^l'"**  ^»  ^^-     1'  the 

a  nut.     2.  The  smaller  ores,  from  the  sTze  ^f  a  nm  1. 1  .    r    T  "  *^"^'*^  ^^t  to  that  of 

The  first  class  of  large  ores  comnrises  thrl  .nW"  -  -^^^  ""^  ^'^'"^  ^^'^"st. 
liferous  rocks,  which"  is^hemoraCndant^^^^^^^  "'"^'^^  '/'  *^^«^^^  «<*  ""^tal. 

one;,er  cen/.  of  mercury;  6,  the  massiVe  sulnhnrPt  nf^  '^^'i^'  ''^  °'"^'  affording  only 

yielding  80  per  cent,  when  it  is  piS    r,  the  fra!^^^^^^^^  ^'^^^^^  «"d  «^est  ore^ 

breaking  and  sorting  and  which  vary  in  Vlef  ?rC  1   o  40  St  ^Z  ^'""'^'"^  ^^"^  *»»« 

The  second  class  of  small  ores  comprises  •  d  the  frn^m^nt-        J^  * 
mine  in  the  state  of  little  pieces,  afforffng  *frL  10  t^?^  "^"; '^^^     T'?'''^  ''™°^thc 
separated  on  the  sieve,  yielding  32  ver  clit   ^tZ  11/ ^^  ^''- '  *'  ^^^  ^«'"els  of  ore 
ed  in  the  treatment  of  the  poor^fore?  W  me«n/  ?  .l^""^  ^^'^ 
lOOpartsof  this^cAZMgiverieastSof^^^^^  ^^^  washing  tables ; 

:^e  general  aspect  of  the  apparatus  is  indicated  b^^g,.  896,  897,  and  898.    Fi,  898 

'^  "  iT/'T\  ^^^   ^^'^"^^-^  ^'"t  only*  one* 

J^»ri?  »\^»°«?h,  as  it  resembles 
exactly  the  other,  which  is  not  shown. 
In  these  three  figures  the  following  ob- 
iT  rX  ^  distinguished;  ^g,.  896, 
897,  a,  door  of  the  fire-place;  6,  the 
furnace  m  which  beech-wood  is  burned 


y  -  '         . -  ..-.^  „.  „  u^^„  ucccn-wooa  IS  burned 
ia^gLL     m«ed  with  a  little  fir-wood;    c,  door 
of  the  ash-pit,  extended  beneath .   rf 


•**  "  K" stT"" —       «. —   —        *-tn.ic  ui-wuiHj;    f    door 

a  space  in  which  the  ores  are  denosited  iinn„  t^f  *^'^  «sh-pit,  extended  beneath;  d. 
Jigs.  896,  and  899;  c  e,  brS  tunnels  bvThU?hr'\*''?^'  i  '**  ^>  ««  ^^^'^^ted  5 
mercury  pass,  on  the  one  side!  Lto^tces'siVe  taJ^L^^^^^^  '^^^  ""^  ^^^  ^^Po«  -^ 


fghijkl are  passages  which  permit  the  circulation  nr  fv 


MERCURY. 


187 


openings  on  each  side  of  the  same  furnace,  and  in  each  half  of  the  apparatus,  which  is 
double,  as yig.  897  shows ;  the  spaces  without  letters  being  in  every  respect  similar  to  the 
spaces  mentioned  below.     Fig.  897  is  double  the  scale  of  yig.  896. 

m  m',  yig.  897,  are  basins  of  reception,  distributed  before  the  doors  of  each  of  the 
chambers/  kf  k'.  The  condensed  mercury  which  flows  out  of  the  chambers  is  conveyed 
thither,  n  n'  is  a  trench  into  which  the  mercury,  after  being  lifted  into  the  basins  m,  is 
poured,  so  that  it  may  run  towards  a  common  chamber  o,  in  the  sloping  direction 
indicated  by  the  arrows,  o  leads  to  the  chamber  where  the  mercury  is  received  into  a 
porphyry  trough ;  out  of  which  it  is  laded  and  packed  up  in  portions  of  50  or  100  lbs. 
in  sheep-skins  prepared  with  alum,  pp',  fig.  896,  are  vaulted  arches,  through  which  a 
circulation  may  go  on  round  the  furnace  a  b  c  d,  on  the  ground  level,  q  q'  are  the  vaults 
of  the  upper  stories,  r  r^,  fig.  898,  vaults  which  permit  access  to  the  tunnels  e'  c", 
fig.  896. 

s  s'  and  /  t',fig.  898,  are  the  doors  of  the  chambers/ fc  and/  k'.  These  openings  are 
f  hut  daring  the  distillation  by  wooden  doors  faced  with  iron,  and  luted  with  a  mortar  of 
clay  and  lime,  u  u'  is  the  door  of  the  vaults  1  to  7  of  the  furnace  represented  in 
fig.  896.  These  openings  are  hermetically  shut,  like  the  preceding,  v  v',  fig.  896,  are 
superior  opeuings  of  the  chambers,  closed  duing  the  operation  by  luted  plugs ;  they  are 
opened  afterwards  to  facilitate  the  cooling  of  the  apparatus,  and  to  collect  the  mercurial 
soot,    xy  z,  fig.  899,  are  floors  which  correspond  to  the  doors  u  u'  of  the  vaults  1  to  7, 


899 


fig.  898.  These  floors  are  reached  by  stairs  set  up  in  the  different  parts  of  the  building, 
which  contains  the  whole  apparatus. 

On  the  lower  arches  the  largest  blocks  of  metalliferous  rock  are  laid ;  over  these  the 
less  bulky  fragments  are  arranged,  which  are  covered  with  the  shivers  and  pieces  of  less 
dimension.  On  the  middle  vaults,  the  small  ore  is  placed,  distributed  into  cylindrical  pip- 
kins of  earthenware,  of  10  inches  diameter  and  5  inches  depth.  The  upper  vaults  receive 
likewise  pipkins  filled  with  the  sands  and  pastes  called  schlich. 

In  3  hours,  by  the  labor  of  40  men,  the  two  double  sets  of  apparatus  are  charged,  and 
all  the  apertures  are  closed.  A  quick  fire  of  beech-wood  is  then  kindled ;  and  when  the 
whole  mass  has  become  sufficiently  heated,  the  sulphuret  of  mercury  begins  to  vapor- 
ize ;  coming  into  contact  with  the  portion  of  oxygen  which  had  not  been  carbonated, 
by  combustion,  its  sulphur  burns  into  sulphurous  acid,  while  the  mercury  becomes  free, 
passes  with  the  other  vapors  into  the  chambers  foi*  condensing  it,  and  precipitates  in  the 
liquid  form  at  a  greater  or  less  distance  from  the  fire-place.  The  walls  of  the  chambers 
and  the  floors,  with  which  their  lower  portion  is  covered,  are  soon  coated  over  with  a 
black  mercurial  soot,  which,  being  treated  anew,  furnishes  50  per  cent,  of  mercury.  The 
distillation  lasts  from  10  to  12  hours ;  during  which  time  the  whole  furnace  is  kept  at 
a  cherry-red  heat.  A  complete  charge  for  the  two  double  apparatus,  consists  of  from 
1000  to  1300  quintals  of  ore,  which  produce  from  80  to  90  quintals  of  running  mercury. 
The  furnace  takes  from  5  to  6  days  to  cool,  according  to  the  state  of  the  weather ;  and 
if  to  that  period  be  added  the  time  requisite  for  withdrawing  the  residuums,  and  attend- 
ing to  such  repairs  as  the  furnace  may  need,  it  is  obvious  that  only  one  distillation  can  be 
performed  in  the  course  of  a  week. 

In  the  works  of  Idria,  in  1812,  56,686  quintals  and  a  half  of  quicksilver  ores  were  dis- 
tilled, after  undergoing  a  very  careful  mechanical  preparation.  They  afforded  4832  quin- 
tals of  running  mercury ;  a  quantity  corresponding  to  about  8^  per  cent,  of  the  ore.  Thes^ 
smelting  works  are  about  180  feet  long  and  30  feet  high. 

Upon  the  preceding  three  systems  of  smelting  mercurial  ores,  I  shall  now  make  some 
observations. 

It  has  been  long  well  known,  that  quicksilver  may  be  most  readily  extracted  from 
cinnabar,  by  heating  it  in  contact  with  quicklime.    The  sulphur  of  the  cinnab^  com- 


I 


138 


MERCURY. 


mJ^.l^^  ^\''"'  J'^!?!'***  prescribed  for  distilling  the  ore  along  with  quicklime  are  r«. 
SMaW^ri"-  •"  '1^'  P'^"*^^^  ^^  LandsbergV  Obermoschel,  ther?ra  «eat  wastt 
mJp^?\  ?*'*^;k^  ^^^  """^erous  small  cucurbits ;  there  is  a  gr^at  waste  of  fuel  inthP 
Sih.  ri?  "^  '^''"  S,^  ^''^'  ^^^t^  °^  '"^^^"ry  ^y  the  imperfect  iS  of  the  retorts 
Xbi;::S^^^^^^^^  condensation  of  ^the  mercurii  [^^^TZ 

rtgdXtl?hTo'"ctr  ^^°"^  '^"^  '"^"^'^  "'^^^^  -^^^^  -^  neverV"tnd1r^^  :£ 

menrsS^f  ti^.*"'^  inconveniences  and  sources  of  loss,  the  proper  chemical  arrange- 
meats  suited  to  the  present  improved  state  of  the  arts  ought  to  be  adopted  bvwhfrh 

itamus  mfo  hf'"^/  "i'''  ""^^-  ^^r^^i-d  to  the%tmosrextent^^'TL  oily 

qmcklime,  may  be  easily  introduced,  from  a  measured  heap,  by  means  of  a  shovel 

(When  .  e^:^" d"oeT;o''t''"colr.hV  c'aTcarurmlt.t  Zr/bl'  o'S^"  S'T 

rtmTave^T?h•*;^^"'"  "="'"'=  '"''  ?''•"  •«  I""  i-to  eieh  of  .Le  aboTe^etm  a'd' 
f„  .hi  /     *       •  ■  "^^  ?f '™P'y  space  for  the  expansion  of  volume  which  may  tMcVnllee 

the  rfou/.? Vlh;  T'  '^P"*^^?."*  *  eheap  and  powerful  apparatus  which  I  contrived  at 

T  «n^T  the  German  Mines  Company  of  London,  and  which  is  now  mouM^  It 

Landsberg,  near  Obermoschel,  in  the  Bavarian  Rhein-K^-eis.  mounted  at 

J'lg.  900,  IS  a  section  parallel  to  the  front  elevation  of  three  arched  benches  of  retorts. 

900 


s 


^m.i^^ 


T- 


[Z33C 


Of  ^the  Size  above  sr^^^^^^^^  3  retorts,  of  the  form  represented  by 

cpal  or  wcixJ,  to  thrthree  rlVts      Th^^tnA«  ''^^^^l''-,f  "^"^-^  ^^^'^^^^  ^^^^^tion  bj 
by  an  English  maLn  perfecuricauai^rH^  w^^^  l""^   "^  ^"  ^"^  ^^^^"e"t  manner, 

retorts,  who  was  sent  over  on'^urS^^^^^  '"^^^^  ^T'i"?  ^oal-ga^ 

similar  to   that  represented  VfiTTio    Dale  R47    Jw  r^K*"^  ''"^^^  ^'  P''^^^^^^^^ 
immersed  in  a  bath  of  uniformly  if;it«i'arwh^I^^^^^  uppermost  retort  is 

top,  pla,  round  the  two  ^n.eL^^^f.o^^C^l^ Z7Ttr;^^^^ 


MERCURY. 


189 


them.  The  bottom  of  the  uppermost  retort  is  protected  from  the  direct  impulse  of  the 
flame  by  fire-tiles.  The  dotted  lines  k  k,  show  the  paths  of  the  chimneys  which  rise  at 
the  back  ends  of  the  retorts. 

In  the  section,  Jig.  901,  a  is  the  body  of  the  retort ;  its  mouth  at  the  right  hand  end 

is  shut,  as  usual,  by  a  luted  iron  lid,  secured 
with  a  cross-bar  and  screw-bolts ;  its  other 
end  is  prolonged  by  a  sloping  pipe  of  cast 
iron,  4  inches  in  diameter,  furnished  with  a 
nozzle  hole  at  l,  closed  with  a  screw  plug. 
Through  this  hole  a  wire  rammer  may 
be  introduced,  to  ascertain  that  the  tube  is 
pervious,  and  to  cleanse  it  from  the  mer- 
curial soot,  when  thought  necessary,  c,  is 
a  cross  section  of  the  main  condenser,  shown 
in  a  longitudinal  section  at  c  c,  Jig.  902. 
This  pipe  is  18  inches  in  diameter,  and 
^bout  20  feet  long.  At  a  a,  &,c.,  the  back 
ends  of  the  retorts  are  seen,  with  the 
slanting  tubes  6  6,  &c.,  descending  through 
orifices  in  the  upper  surface  of  the  con- 
denser pipe,  and  dipping  their  ends  just 
below  the  water-line  h  i.  g,  is  the  cap  of 
a  water  valve,  which  removes  all  risk  from 
sudden  expansion  or  condensation.  The 
condenser  is  placed  within  a  rectangular  trough,  made  either  of  wood  or  stone,  through 
which  a  sufficient  stream  of  water  passes  to  keep  it  perfectly  cool,  and  repress  every 
trace  of  mercurial  vapor,  and  it  is  laid  with  a  slight  inclination  from  i  to  A,  so  that  the 
condensed  quicksilver  may  spontaneously  flow  along  its  bottom,  and  pass  through  the 


vertical  tube  d  into  the  locked  up  iron  chest,  or  magazine  e.  This  tube  d  is  from  the 
beginning  closed  at  bottom,  by  immersion  in  a  shallow  iron  cup,  always  filled  with  mer- 
cury, fe  is  a  graduated  gauge  rod,  to  indicate  the  progressive  accumulation  of  quicksilver 
in  the  chest,  without  being  under  the  necessity  of  unlocking  it. 

This  air-tisht  apparatus  was  erected  about  a  year  ago,  and  has  been  found  to  act 
perfectly  well ;  I  regret,  however,  that  my  professional  engagements  at  home  have  not 
hitherto  permitted  me  to  conduct  its  operations  personally  for  some  days.  The  average 
samples  of  cinnabar  ore  from  Obermoschel  are  ten  times  poorer  than  those  of  Almaden. 
Were  such  an  apparatus  as  the  above,  with  some  slight  modifications  which  have  lately 
occurred  to  me,  mounted  for  the  Spanish  mines,  I  am  confident  that  their  produce  in 
quicksilver  might  be  nearly  doubled,  with  a  vast  economy  of  fuel,  labor,  and  human 
life.  The  whole  cost  of  the  9  large  retorts,  with  their  condensing  apparatus,  iron 
magazine,  &c.,  was  verv  little  more  than  tv^o  hundred  pounds  !  As  the  retorts  are  kept 
in  a  state  of  nearly  uniform  ignition,  like  those  of  the  gas  works;  neither  they  nor 
the  furnaces  are  liable  to  be  injured  in  their  joints  by  the  alternate  contractions  and 
expansions,  which  they  would  inevitably  sufler  if  allowed  to  cool ;  and  being  always 
ready  heated  to  the  proper  pitch  for  decomposing  the  mercurial  ores,  they  are  capable 
of  working  oft'  a  charge,  under  skilful  management,  in  the  course  of  3  hours.  Thus, 
in  24  hours,  with  a  relay  of  laborers,  8  charges  of  at  least  5  cwts.  of  ore  each, 
mi<'ht  be  smelted =2  tons,  with  3  retorts,  and  6  tons  with  9  retorts ;  with  a  daily 
proluct  from  the  rich  ores  of  Almaden,  or  even  Idria,  of  from  12  cwts.  to  20  cwts. 
Instead  of  3  benches  of  3  retorts  each,  I  would  recommend  15  benches,  containing  45 
retorts,  to  be  erected  for  either  the  Almaden  or  Idria  mines ;  which,  while  they  would 
smelt  all  their  ores,  could  be  got  for  a  sum  not  much  exceeding  1000/.,  an  outlay  which 
thev  would  reimburse  within  a  month  or  two.  .  .     ^  j.x.  •  i 

ThrfoUowing  letter  from  Dr.  Tobin  gives  an  interesting  account  of  the  me/curial 

mines  In  California. 


I 


' 


il 


140 


MERCURY. 


That  part  of  California  where  I  have  been  residing,  and  that  which  I  have  just  visited, 
consists  of  three  long  ranges  of  trapp  mountains,  with  two  wide  valleys  dividing  them, 
the  valley  of  the  Saa  Joaqum,  and  the  valley  of  Santa  Clara.     Near  this  last  place  are 
the  quicksilver  mines  of  New  Almaden,  where  I  have  been  working.    The  matrix  of  the 
cinnabar  ore  is  the  same  trapp  of  which  the  mountain  ranges  are  composed,  and  as  yet 
only  one  great  deposit  of  this  ore  has  been  found,  though  traces  of  quicksilver  ores  have 
been  discovered  m  other  places.    The  ores  are  composed  solely  of  sulphuret  of  mercury 
(averaging  36  per  cent^  red  oxide  of  iron  and  silica;  and  had  the  mine  been  properly 
worked  from  the  commencement  almost  any  quantity  of  ore  might  be  extracted  •  it  now 
however,  more  resembles  a  gigantic  rabbit  warren  than  a  mine.   The  owners  have  lately 
sent  out  an  old  German  miner,  an  expeiienced  and  practical  man,  who,  if  he  stavs  here, 
will  eventually  put  it  into  some  kind  of  order.    Its  greatest  depth  is  about  150  feet,  and 
the  weekly  extraction  of  ores  varies  from  100  to  150  tons.     Upon  arriving  here  I  found 
the  concern  in  such  a  state  of  disorganization,  that,  after  waiting  three  months  in  vain, 
and  not  having  received  a  single  cylinder  or  piece  of  machinery,  I  returned  to  Mexico 
to  tetch  up  one  of  the  proprietors.     During  my  absence  the  former  director,  who  in  his 
lile  had  never  seen  a  mine,  much  less  smelting  works,  put  up  four  of  the  cylinders,  sup- 
porting them  solely  upon  their  two  ends  without  any'fire-brick  guards  or  pillars.     Of 
course,  when  heated  they  sunk  or  sagged  in  the  middle.     Upon  my  return  with  one  of 
the  ownere,  something  like  order  was  established  by  him,  and  I  got  16  cylinders  at 
work,  producing  1400  to  1500  lbs.  daily.     The  result  to  me  was  satisfactorv.  but  not 
so  to  the  proprietor,  on  account  of  the  expense  of  fuel  and  labor;  he  accordingly  got  a 
blacksmith,  who  had  been  sent  here  to  jput  up  the  water-wheel,  to  build  him  a  small 
furnace,  without  consulting  me  at  all.     This  man  sent  a  friend  of  his,  not  liking  to  come 
himself;  to  look  at  the  plans  I  had  of  the  furnaces  of  Idria  and  Almaden,  and  then 
erected  a  snaall  and  miserable  furnace  to  hold  one  ton  of  ore,  upon  a  disimproved  plan 
of  those  of  Idna.     With  this  he  obtained  from  the  richest  ores  (66  to  72  per  cent)  38 
per  cent  of  mercury,  of  course  with  the  consumption  of  very  little  wood  and  with  little 
labor;  (the  loss  of  per  centage  was  not  thought  about!)    The  proprietor  immediately 
determined  to  have  six  similar  furnaces  built  and  with  great  regret  allowed  me  to 
erect  one  good  furnace,  and  afterwards  a  second  one. 

«  Now  take  the  results  of  the  year's  work,  and  you  can  judge  whether  the  report  sent  you 
if  i/^  ^f  ?^*'        •  ^^  ^^a^kee  blacksmith  has  superseded  me  or  not    Before  the  year  was 
out,  he  got  tired  of  attempting  to  compete  with  my  furnaces,  and  left  in  disgust 


The  cylinders  produced 

(but  were  stopped  in  November  on  account 

of  expense  of  working) 

The  first  furnace,  working  only  from  November  1st  to 

July  Ist,  1851,  gave  -  -  -  .  . 

The  second  furnace,  working  only  from  March  18th  to 

July  Ist,  gave  -  -  -  .  . 


-    261,616  lbs.  Mercury 


620,613 


888,825 


_-  ,  Total  1,255,954 

"The  product  of  the  Yankee's  six  furnaces,  working  for  a  much  longer  period  as 
they  went  mto  operation  long  before  mine,  was  only  644,000  lbs.,  making  a  total  pro- 
duct  for  the  year  of  about  18,000  quintals."  ^ 

Quicksilver  is  a  substance  of  paramount  value  to  science.  Its  great  density  and  its 
regular  rate  of  expansion  and  contraction  by  increase  and  diminution  of  temperature 
give  it  the  preference  over  aU  liquids  for  filling  barometric  and  thermometric  tubes.  In 
chemistry  it  furnishes  the  only  means  of  collecting  and  manipulating,  in  the  pneumatic 
trough,  such  gaseous  bodies  as  are  condensible  over  water.  To  its  aid,  in  this  respect 
the  modern  advancement  of  chemical  discovery  is  pre-eminently  due. 

This  metal  alloyed  with  tin-foil  forms  the  reflecting  surface  of  looking-glasses  and 
by  its  ready  solution  of  gold  or  silver,  and  subsequent  dissipation  by  a  moderate  heat 
It  becomes  the  great  instrument  of  the  arts  of  gilding  and  silvering  copper  and  brass 
The  same  property  makes  it  so  available  in  extracting  these  precious  metals  from  their 
ores^  The  anatomist  applies  it  elegantly  to  distend  and  display  the  minuter  vessels  of 
the  lymphatic  systeu^  and  secretory  systems,  by  injecting  it  with  a  syringe  through  all 
their  convolutions.  It  is  the  basis  of  many  very  powerful  medicines,  at  present  proba- 
bly too  indiscriminately  used,  to  the  great  detriment  of  English  society-  for  it  is  far 
more  sparingly  prescribed  by  practitioners  upon  the  continent  of  Europe,  not  other- 
wise superior  in  skill  or  science  to  those  of  Great  Britain. 

The  nitrate  of  mercury  is  employed  for  the  secretage  of  rabbit  and  hare-skins,  that  is, 
for  communicating  to  fur  of  these  and  other  quadrupeds  the  faculty  of  felting  which 
they  do  not  naturally  possess.  With  this  view  the  solution  of  that  salt  is  applied  to 
them  lightly  m  one  direction  with  a  sponge.  A  compound  amalgam  of  zinc  and  tin  is 
probably  the  best  exciter  which  can  be  applied  to  the  cushions  of  electrical  machines. 


METALLIC  FUMES. 


141 


The  only  mercurial  compounds  which  are  extensively  used  in  the  arts,  are  factitious 
cirab^Jr  Vermilion,  and  corrosive  sublimate.  Quantity  imported  for  home  con- 
sumption  in  1860,  355.019  pounds  ;  in  1851,  27,370  pounds.  ,  •    t^  •     o  f^wn 

A  large  quantity  of  mercury  or  quicksilver  is  annually  produced  in  Idria,  a  town 
inthe  dlci?yof  Carniola,  the  InhalJitants  of  which  are  chiefiy  occupied  m  its  extrac- 
t^^on  The%uicksilver  mines  are  extremely  productive,  the  cmnabar  ore  yields 
when  very  rlX  60  per  cent  of  this  metal  This  ore  is  a  sulphuret  of  mercury,  and 
ffives  UP  the  latter  metal  by  sublimation. 

^  With  the  quicksilver  mines  of  Idrla  is  connected  a  manufactory  of  vermilion,  which 
produced,  in\he  year  1847,  981  cwt  of  that  pigment  The  residue  of  the  q^ic^s^lvei 
is  used  up  to  some  small  extent,  about  300  cwt,  for  technical  purposes  and  prepara- 
t  ons ;  but  the  greater  portion  of  it  is  sent  abroad.  The  exports  of  q«^eks^lJeJ 
amounted  to  an  annual  ^vera^e  of  2,341  cwt  (in  the  year  1846  they  reached  6,478 
cwt),  and  of  preparations  denved  from  it,  such  as  corrosive  subhmate,  calomel,  Ac., 
to  41  cwt  By  the  consumption  of  quicksilver,  for  the  manufacture  of  vermilion  and 
for  other  technical  purposes,  the  value  of  the  annual  produce  of  the  raw  material  is 
greatly  increased.  The  mines  have  been  worked  for  upwards  of  three  centuries  and 
a  Imlf  and  were  oricinallv  discovered  by  an  accident  , ,  ,  «_ 

MFRCURY  BICHLORIDE  OF;  Corrosive  sublimate  (DeuiochJarure  de  mercure,  Fr. ; 
Jetzendes  quecksilber  sublimat,  Germ.),  is  made  by  subliming  a  mixture  of  equal  parts  of » 
persSphate  of  mercury,  prepared  as  above  described,  and  sea-sa  t,  m  a  stoneware  cucur. 
bit  The  sublimate  riles  invapor,  and  incrusts  the  globular  glass  capital  with  a  white 
mais  of  small  prismatic  needles.  Its  specific  gravity  is  5- 14.  Its  taste  is  acrid,  stypto- 
SSallic,  and  exceedingly  unpleasant.  It  is  soluble  in  20  parts  of  water,  at  the  ordinary 
Smpe  a  ure,  and  in  its  own  weight  of  boiling  water.  It  dissolves  m  2^  times  its  weight 
of  cold  alcohol.  It  is  a  very  deadly  poison.  Raw  white  of  egg  swallowed  »« jf^s^o". 
is  the  best  antidote.  A  solution  of  corrosive  sublimate  has  been  long  empMed  for  pre- 
"ervin?  soft  anatomical  preparations.  By  this  means  the  corpse  of  Colonel  Morland  was 
eSmed  in  order  to  be  brought  from  the  seat  of  war  to  P^is.  His  features  remained 
unaltered,  only  his  skin  was  brown,  and  his  body  was  so  hard  as  to  sound  hke  a  piece  of 
wood  when  struck  with  a  hammer.  _ 

In  the  valuable  work  upon  the  dry  rot,  published  by  Mr.  Knowles,  secretary  of  the 
•ommittee  of  inspectors  of  the  navy,  in  1821,  corrosive  sublimate  is  enumerated  among 
the  chemical  substances  which  had  been  prescribed  for  preventing  the  dry  rot  m  timber; 
and  it  is  weU  known  that  Sir  H.  Davy  had,  several  years  before  that  date,  us«I  and 
recommended  to  the  Admiralty  and  Navy  Board,  corrosive  sublimate  as  an  anti-dry  rot 
application.  It  has  been  since  extensively  employed  by  a  jomt-stock  company  tor  ine 
same  purpose,  under  the  title  of  Kyan's  patent.  , .  .  t^, 

MERCURY,  PROTOCHLORIDE  OF;  Calomel;  (Protochlorure  de  ^"^^'^yJ/'\ 
Versiisstes  quecksilber,  Germ.)  This  compound,  so  much  used  and  abused  by  medical 
practitioners,  is  commonly  prepared  by  triturating  four  parts  of  corrosive  subhmate  along 
with  three  parts  of  running  quicksUver  in  a  marble  mortar,  tiU  the  metallic  globules 
entirely  disappear,  with  the  production  of  a  black  powder,  which  is  to  be  put  into  a  glass 
baUoon,  and  exposed  to  a  subliming  heat  in  a  sand  bath.  The  calomel,  ^^ich  rises  m 
vapor,  and  attaches  itself  in  a  crystalline  crust  to  the  upper  hemisphere  of  the  balloon, 
is  to  be  detached,  reduced  to  a  fine  powder,  or  levigated  and  elutriated.  200  lbs.  of  mer- 
cury yield  236  of  calomel  and  272  of  corrosive  sublimate.  .  ,  rr  i, 
The  following  more  economical  process  is  that  adopted  at  the  Apothecaries  Hall, 
London  140  pounds  of  concentrated  sulphuric  acid  are  boiled  in  a  cast  iron  pot  upoa 
100  pounds  of  mercury,  till  a  dry  persulphate  is  obtained.  Of  this  salt,  124  pounds  are 
triturated  with  81  pounds  of  mercury,  tQl  the  globules  disappear,  and  till  a  protosolphate 
be  formed.  This  is  to  be  intimately  mixed  with  68  pounds  of  sea-salt,  and  the  mixti^ 
being  put  into  a  large  stone-ware  cucurbit,  is  to  be  submitted  to  a  subliming  heat.    See 

^  Fm^l90  to  200  pounds  of  calomel  rise  in  a  crystalUne  cak^  as  in  the  former  pro- 
cess,  into  the  capital;  while  sulphate  of  soda  remains  at  ^^^bottom  of  the  alembic. 
The  calomel  must  be  ground  to  un  impalpable  powder  and  elutriated.  The  vapory 
instead  of  being  condensed  into  a  cake  within  the  top  of  the  globe  or  in  a  capital,  may  be 
allowed  to  diffuse  themselves  into  a  close  vessel,  containing  water  in  a  state  of  ebulli 
tion  whereby  the  calomel  is  obtained  at  once  in  the  form  of  a  washed  impalpable 
powder      Calomel  is  tasteless  and  insoluble  in  water.     Its  specific  gravity  is  7  176. 

For  the  compound  of  mercury  with  fulminic  acid,  see  Fulmlnate.  PmW«fe  of 
tnercurv  is  a  bright  but  fugitive  red  pigment  It  is  easily  prepared  by  droppmg  a  so- 
lution of  iodide  of  potassium  into  a  solution  of  corrosive  sublimate,  as  long  as  any  pre- 
cipitation takes  place,  decanting  off  the  supernatant  muriate  of  potash,  washing  and 

^'fe'i^'v^'S'iS'/or,  b,  Mr.  Morgan  of  Dublin.     If  a  strong  solution  of  iodide  of 
poSi^  beaded  to  i  iinute  portion  of  any  of  the  salts  of  mercury,  placed  on  a 


142 


METALLIC  STATISTICS. 


lea^tTolor:^^^^^  detecte<^  although  the  mixture  with  s^arTnot  i^Te 

least  colored  by  it.     With  the  preparations  of  mercury  in  the  undiluted  state  thi« 
process  acts  with  remarkable  accuracy,  the  smallest  quintity  of  caS  or  peroxide 
placed  on  copper  as  above,  will  give  with  iodide  of  potassium  a  distinS  metaUic  stli^ 
Mr  Morgan  supposes  that  the  iodide  of  potassium  forms  a  soluble  salt  wiTh  the  seveS 
MFTaTtIp  ^i^  decomposed.-PA.  Journ,,  Feb.  1852.  '^""^^ 

METALLIC  ANALYSIS.     Professor  Liebig  has  lately  enriched  this  moaf  «««f„l 
tT'^r'  ^'  ^'^''''^^  chemistry,  by  the  e^plojnnent  VthTcyi  d"^^^^^^ 
^IZT^  '°  V 'i  ?««"r/"^^  J^'^^""^  («^^  *^'«  ^^^i«l«)-     Th'«  ««lt  is  the  best  regent  fo^ 
fal^K  "^^"/^'^  m  cobalt     The  solution  of  the  two  metals  being  acidulated,  the  cyanide 

s  ttn?ddef  a?d' thl^'  ^^ P^If'"  '^''  ^''^^^^"V«  redissolvel  Dilute  sulphurS 
f«n  t«  '    ^  ^^^  mixture  being  warmed  and  left  in  repose,  a  precipitate  does  nc« 

fail  to  appear  sooner  or  later,  which  is  a  compound  of  nickel      Cvanide  of  nntn«Jnm 

eadTnd  Sl^fth  f?ii  ^""1!^^  '"^  ^^"'J'  '°  ^^^  '^'"^'"'^  of  these  metals  in  nitric  acid, 
add  SulnrrPtti  vh'  '^•^^°'?^^^^'  ^1^.  °^^y  be  parted  from  each  other  by  sulphuric 
acid,  bulphuretted  hydrogen  is  passed  m  excess  through  the  residuary  solution  and 
the  mixture  being  heated,  a  small  quantity  of  cyanide  is  added :  TyelWpred^^^ 

^pp"  hfpTrni;"'  '  '^"'  ^"^^^^^^^^  '^"^  ^'^  ^^^  ^'^^^^-^  of  CrocSfoTaSd/tf 

'A  K^^lu  *  ^^"^^b.^«  (containing  the  cyanide  fused  by  heat),  a  little  of  anv  metallic  ox 
WhJn    t'T"^?'  intervals,  it  will  be  almost  immediately  reduced  to  the  rL^^^^^^^ 

whiLsdinfmltTerfrl'w^^^^^^  decanted,  the  metal'will  be  found  mTxId^Uh  the 
wmie  sajine  matter,  from  which  it  may  be  separated  by  water. 

in  «1t;?tf  Ti  '"^p5"^^.^«  *^^  'Educed  to  the  state  of  pure  metals  by  bein-  proiected 
LIL.,?^  ^"k"  ^'''^^''.  *"*^  ^^"^  ^"«^^  ^y'^^i'le-  When  an  iron  ore  is  thus  hu/^ucS^ 
alTrl  ^^  carbonate  of  potash  or  soda,  and  the  mixture  is  heated  to  fusbnwS^^ 
quires  a  strong  red  heat,  the  alumina  and  silica  of  the  ore  fuse  into  a  s  as  from  w hi^r 
l7mTn'a^Se  feS:;tlh;^r^^  separated  by  the  action  o^^er^,  :L^d^'hen:eTgS 
"separate  nroce.      w\l^    '}   T^'"'  ""  ^^^  '*^*^  of  protoxide  ;  to  be  determined  by 

T,l^'r%Z7:t  C/r'tLlTettra'"""^''^'  ''  •"  "^  ''-'  and  1  J^^X^ 

bei^^\cSSifhedlT»  w  P«"«"lr  iM"«'>n?  with  the  oxide  of  antimony  and  tin  ; 
oem,  accomplished  at  a  low  red  heat,  hardly  visible  in  daylight.    Even  the  sulDhnrrti 

cyanS:  or;:!t\:sTur^'^^^^^^  ^^"^^^^  ^^^^^'^  -^^^-^  -^^^  ^^^  fo^at^oro^ft^rpr 

Pb^onlratlrfor 'i^ r'  ""^t^  "^'^^  '^'i^^"^^^  °^  «^^'  ^'  °»  ^^^^"ent  re-agent  in  blow- 
facmtv  In^^L  f(,if  "^T^'"§  ""^'^^'*  "^^^  reductions  take  place  with  the  utmoTt 
Sone  is  ant  to  do  ?n  such'clr  ^V  ""'  T^  '"^"  '^'  charcoal,  as  carbonate  of  3a 
:nd"Ln  ^'beVe'r  exrined.""  "'"^'^  ''*^  ^^^^"^  °^  ^^^^«  «^  ^^'^'  «-  -°-  visible. 
When  the  cyanide  is  heated  along  with  the  nitrates  and  chlorates  (of  notash^  it  ran«*.. 
a  rapid  decomposition,  accompanied  with  light  and  explosions     ^     Potash),  it  causes 

:t  t-.fh'T  ^"7  ^l^^^fy  detected  in  the  commercial  sulphuret  of  antimony  by  fusing 
tZ  V^^'  ^''"'^';'  °^'*'  ^-^'^^^  °^  ^^^  ^y«"ide  in  a  porcelain  crucibTe  over  a  sn  rk 
lamp  when  a  regulus  of  ant  mony  is  obtained.     The  metal  may  then  be  elsily  tes  ed 

th^JJ^^^oT^^^r^Il^  ''*'^^'  "'■  orpiment,  or  any  of  the  arseniates,  are  mixed  with  six  tim*., 
their  weight  of  the  mixture  of  cyanide  and  carbonate  of  soda  in  ^tuhewiih  a  bu  b^at 

the  sihca  gets  combined  with  the  alkali  into  a  soluble  glass      "''"'^^  *  carbonate,  and 

METALLIC  FUMES  (CONDENSTATION  OF),  6y  Ih/iuke  of  JBncdeugh.-ln  all 

great  smelting  works  of  lead  and  copper,  the  smoke  rising  from  the  furna^s  is  hiehlv 

charged  with  the  most  noxiou.  va|.oi-s,  containing,  besides  other  poisonous  mattSr  a 


METALLIC  STATISTICS. 


143 


laree  quantity  of  lead.     Many  attempts  have  been  made  to  obviate  this  nuisance .  and 
the  system  al         by  the  exhibitor  has  been  found  to  be  very  successful 

l/oblong  building^in  solid  masonry,  about  30  feet  in  height  is  divided  by  a  part  - 
tionwalinL  two  chambers,  having  a  tall  chimney  or  tower  adjoining,  whicli  commu- 
mcatls  wilh  onlof  the  chambers  at  the  bottom.  The  smoke  from  the  various  furnaces, 
e^htTnTumber  and  about  100  yards  distance  from  the  condenser,  is  carried  by  separ- 
Tte  flJes  iTo  a  large  chamber;  from  thence  by  a  larger  flue  it  enters  the  first  chamber 
of  the  condenser  at  the  very  bittom,  and  is  forced  upwards  in  a  zigzag  course  towards 
SetoD  Sne  four  times  through  a  shower  of  water  constantly  percolating  from  a 
Irced  reXoir  at  the  summit  of  the  tower.  The  smoke  is  again  co^Pfll^^/^  fi^^^;. 
rfifthtfme  through  a  cube  of  coke,  some  2  feet  square,  through  which  a  stream  of 
water  fiS  downlards,  and  which  is  confined  to  its  proper  limits  by  a  vertical  grat- 
J^g  of  wood     TTieTmoke  having  reached  the  top,  is  now  opposite  the  passage  into  the 

second  or  vacuum  chamber.  ,  •      ,         k  r^^f  k,t  ^J  foof  ina?<lA  and  HO 

This  is  termed  the  exhausting  chamber,  and  is  above  5  feet  by  7  feet  inside,  and  »u 
„efeetTn  height  On  its  summit  is  fixed  a  large  reservoir,  supplied  by  an  ample 
stream  of  water  alwavs  maintaining  a  depth  of  6  to  10  mches.         ,  ^    ,^  .  , 

Trbotl^m  of  this  tank  is  of  iron,  having  several  openings  or  slots,  12  m  number, 
ablut  an  inch  in  width,  and  extending  across  the  whole  area  of  the  reservoir  commu- 
nSi  Srecily  with  the  chamber  beneath.  On  this  iron  plate  works  a  hydraulic 
TdeZte   with  openings  corresponding  in  one  position  with  those  in  the  reservoir 

ThisTate  receiv^^  reciprocating  motion  from  a  water-wheel  or  other 

nower  driven  by  means  of  a  connecting-rod  and  crank. 

^Li  the  middle  of  every  stroke,  the  openings  in  the  plate  correspond  with  thc«e  in  the 
boUom  of'the  reservoir,^  a  powerful  body  of  water  falls  as  a  sh^^^^^^^^^  :^;'', 

\xaicht  nf  thP  vacuum  chamber:  and,  in  doing  so,  sweeps  the  entire  inside  area,  carry 
llfgtltri^evorrparticrof  i^oluble  mattir,  held  .LpenM  in  the  vapora  eomtng 

^^he'SXSc  pressure,  of  course,  acts  in  alternate  strokes  as  a  Wast  at  the  for- 
nalmouThs  and  causes  a  d  aft  sufficiently  strong  to  force  the  impure  vapors  through 
ae  various  channels  in  connection  with  th'e  water,  the  wet  coke  and  cd.aust.ng  cham- 

pie!  i^to  grlat  dykts  or  rcLrvoi..  excavated  for  the  purpose ;  and  then  deposit*  at 

'XmeX"ltSff«met  passing  from  the  shafts  of  the  furnaces  poisoned  the 
„ef°hwf.ood:  the  heather  w«sVrnt%.  vegetation  destroyed,  and  no  anun.1  could 

^'iTthetl'en\T^Uriri"n  in  all  its  native  luxuriance  close  around  the  establish- 
ment   and  tie  sheep  gmze  within  a  stone's  throw  of  the  chimney's  base,  and  game  on 

history,  mines  were  ""'i*,"^ ''"^i^^p^^  „„„  the  Land's  End;   in  Gwennap,  near 

Tru:^"a^d  ':  Sw  th^  -a'  tt  Spoint  The  traditionary  statement  tLt  th« 
iruro ,  ana  J^^au^  ^    Britons  in  Cornwall  are  very  fairly  supportea  by 

r^rSfvltct  ;tnditTs'l  improbable  that  the  Ictes  or  Iktis  of  tie  ancients  wa. 

^n^'rhe  «L.n*':rKi.:^Tohrthe"mines  of  the  western  portion  of  England  appear  t^ 
have  beerprinoipallv  in  th^  hands  of  the  Jews.    The  modes  of  ^"/king  must  have 

b":  v:r;  cU.  V/  *-  ™  tid^jt^^vr^eTwr n  d&t 

^nin'^rorn^l'^tTiTC'^notlt^^ln^^^^^ 

iESg^±as-^"^Ein^:«l=rai>-^^^^^^^ 

''%^7^::^^s'^T.n'i^^'iT^^'''>^e^^  -  cuiiousand  instraetive  At  the 
r.;„LT„  Stream  Works,  north  of  Falmouth,  the  rounded  pebbles  of  tin  are  found  at 
Xthla^^SOfTetfrL  the  surface,  beneath  the  bottomof  an  cstua^^^^ 
Le  Covered  in  their  places  of  growth,  t-^e^er  with  tam.m  s^^^^^^^ 
of  deer  amidst  the  vegetable  accumulations  which  immediately  "»*«'  "■«"",  .  ,„ 
Iwdf  A^ordine  to  Mr.  Kenwood's  measurement  the  section  presents  first  about  50 
^t  of  siH  and  gravel;  then  a  bed  of  18  inches  in  thickness  of  wood,  leaves,  nnt^  *«•. 
^ting  on  fhe  tfrgroind.  composed  of  the  debris  of  quartz,  slate,  and  granite,  a^d  the 


144 


MEATALLIC  STATISTICS. 


tin  ore.  At  the  Pentuan  "Works,  near  St  Austell,  similar  deposits  occur,  proving  a 
material  alteration  in  the  level  during  the  period  expended  in  the  formation  of  this  de- 
posit Tin  is  also  worked  out  of  the  lode  in  many  parts,  the  ore  occurring  both  in  the 
slate  and  the  granite  formations.  The  modes  of  dressing  the  tin  ore,  preparing  it  for 
the  smelter,  and  the  process  of  smelting,  are  illustrated  in  the  Exhibition. 

There  has  been  a  remarkable  uniformity  in  the  quantity  of  tin  produced  in  Cornwall 
during  a  long  period,  as  will  be  seen  from  the  following  table : — 


Years. 

Tons. 

Price  per  cwt 

&       & 

1760 

1,600 

1760 

1,800 

1770 

2,000 

1780 

1,800 

8      0 

1790 

2,000 

8    15 

1800 

1,500 

6      0 

1810 

1,400 

7      0 

1820 

1,700 

3      5 

1830 

3,500 

3      0 

1840 

5,000 

3     15 

The  produce  of  this  metal  within  the  last  few  years  has  been  as  follows :— 


Years. 

Tons. 

1844 

7,607 

1845 

7,739 

1846 

8,945 

1847 

10,072 

1848 

10,176 

1849 

10,719 

The  produce  of  zinc  is  not  easily  attainable,  but  it  is  now  somewhat  considerable,  as 
is  also  that  of  arsenic,  and  of  the  iron  pyrites,  used  in  the  manufacture  of  sulphuric  acid- 
The  number  of  individuals  employed  in  59  Cornish  copper  mines  was  computed  by 
Sir  Charles  Lemon  in  1837,  to  be — 

Men  -  -  -    10,624 

Women        -  -  -      3,802 

Children      -  •  -      3,490 

The  men  alone  work  underground ;   the  women  and  children  are  employed  on  the 
Bur&ce  picking  and  dressing  the  ore. 
Mr.  W.  Henwood  estimates  the  number  employed  at — 

Men  -  -  -    18,472 

Women        -  -  -      5,764 

Children      -  -  -      5,764 


80,000 


Tin  appears  to  have  been  raised  in  Cornwall  from  a  very  early  period.  Traditionary 
evidence,  supported  by  strong  corroborative  facts,  appears  to  prove  that  the  kingdoms 
around  the  Mediterranean  Sea  were  supplied  with  tin  from  Cornwall  by  the  Phoenician 
merchants  at  a  very  early  date.  The  circumstance  of  this  metal  being  found  in  the 
beds  of  streams,  and  in  deposits  at  the  base  of  the  primary  rocks,  from  which  it  could 
be  obtained  without  much  labor,  may  have  been  the  cause  of  its  being  early  known  to 
the  Britons. 

The  oxide  of  tin  is  usually  found  deposited  in  beds  in  water-worn  pebbles,  and  mixed 
with  the  debi-is  of  the  neighboring  hills.  There  can  be  but  little  doubt  that  these  tin 
deposits  are  the  result  of  the  disintegrating  action  of  the  atmospheric  causes  and  of 
water.  Some  of  the  tin  beds,  30  or  60  feet  from  the  present  surface,  contain  vegetable 
matter,  as  branches  of  trees  and  lai^e  logs  of  wood ;  and  at  Carnon  Stream  Works, 
human  skulls  were  discovered  amidst  the  debris,  63  feet  below  the  surface.  Tin  is  also 
found  in  the  lode,  either  as  peroxide,  cupreous-sulphuret  of  tin,  or  tin  pyrites,  the 
analysis  of  the  peroxide  giving  peroxide  of  tin,  96-265  ;  silica,  0-750;  peroxide  of  iron 
and  manganese,  3-395. 

Many  indications  of  early  tin-mining  are  to  be  found  in  Cornwall,  as  stated  in  pre- 
ceding note.  For  many  centuries  the  Duke  of  Cornwall  drew  a  large  revenue  from  ita 
tin.  The  tin,  when  smelted  into  blocks,  was  forwarded  to  the  nearest  coinage  town, 
there  to  be  stamped  by  the  duchy  oflScers,  who  cut  a  piece  of  the  comer  of  each  block, 
which  was  retained  as  the  duchy''s  dues.  In  1337,  Edward  the  Black  Prince  was  cre- 
ated Duke  of  Cornwall,  and  then  the  average  profit  of  the  coinage  was  4,000  markii 


METALLIC  STATISTICS.  145 

per  annum.  In  1814,  the  revenues  to  the  duchy  from  tin  was  about  8,600/.,  and  the 
average  tin  revenue  from  1820  to  the  abolition  of  the  coinages  in  October,  1838,  haa 
been  estimated  at  12,000/.  per  annum.  In  1760,  about  2,000  tons  of  tin  were  producer 
in  Cornwall,  and  in  1838,  about  5,000.  Since  that  period  the  quantity  can  be  accu- 
rately ascertained,  the  trade  in  tin  being  in  the  hands  of  a  few,  and  the  purchases  of  ore 
being  usually  made  by  private  contract 

By  the  returns  to  five  several  orders  made  by  the  House  of  Commons,  which  were 
obtained  by  the  exertions  and  perseverance  of  Sir  J.  J.  Guest  Sir  C.  Lemon,  aod  Mr. 
Evans  (M.  P.  for  North  DerbyshireX  ^^  are  enabled  to  lay  before  our  readers  a  moet 
correct  accountof  the  various  exports  and  imports  of  iron  and  iron  ore,  hardware,  cutlery, 
Ac,  copper  ore,  tin,  zinc,  lead  ore,  and  lead,  for  the  year  ending  Jan.  6,  1844. 

Commencing  with  iron,  it  appears  there  was  imported  in  tlie  year^  iron  ore,  131 
tons;  chromate  of  iron,  1393  tons;  pig-iron,  243  tons;  unwrought  iron  in  bara, 
12,795  tons;  bloom,  663  tons;  rod-iron,  12  tons;  old,  broken,  and  cast-iron,  286 
tons;  cast-iron,  only  8  tons;  steel,  unwrought,  1697  tons— of  these,  97  tons  only 
were  entered  by  weight  the  remainder  by  value,  11036/.  6«.  9<i  Of  the  several 
countries  from  which  these  importations  came,  the  principal  is  Sweden,  whence  we 
have  received  of  iron  10,909  tons,  and  steel  1668  tons,  leaving  but  a  small  portion  to 
divide  between  twenty  other  places.  Our  exports  of  foreign  iron  have  been,  unwrought 
in  bars,  3986  tons ;  rod,  10  tons ;  hoops,  2  tons ;  cast-iron,  11  cwt ;  steel,  unwrought 
1456  tons.  The  total  quantity  of  foreign  iron  retained  for  home  consumption  waa 
14,782  tons,  upon  which  the  net  amount  of  duty  was  14,563/.  The  exportation  of 
that  staple  produce  of  our  own  country,  British  iron,  was  as  follows: — Bar-iron, 
176,148  tons;  bolt  and  rod,  22,625  tons;  pig-iron,  164,770  tons;  cast-iron,  16,449 
tons;  iron  wire,  1508  tons;  wrought-iron,  consisting  of  anchors,  grapnels,  Ac,  8068 
tons ;  hoops,  14,591  tons ;  nails,  6020  tons ;  and  all  other  sorts,  except  ordnance, 
44,677  tons;  old  iron  for  manufacture,  6924  tons;  and  unwrought  steel,  3199  tons. 
Those  places  which  have  taken  the  greatest  portions  of  this  produce  are — Russia, 
10,963  tons  of  bar-iron;  Denmark,  10,447  tons  bar,  and  7010  tons  pig;  Prussia,  12,009 
tons  bar,  17,480  tons  pig ;  Germanj^  13,298  tons  bar,  6322  tons  pig,  1339  tons  cast; 
Holland,  17,509  tons  bar,  75,953  tons  pig;  4317  tons  cast;  Belgium,  4270  tons  cast- 
France,  4237  tons  bar,  22,103  tons  pig;  Italy,  21,930  tons  bar,  3982  tons  bolt  and 
rod,  3005  tons  pig;  Turkey,  and  Continental  Greece,  6412  tons  bar;  East  Indiea 
and  Ceylon,  20,620  tons  bar,  2967  tons  bolt;  British  North  American  Colonies,  6837 
tons  bar,  1995  tons  cast;  Foreign  West  Indies,  5043  tons  bar,  1646  tons  cast;  and  to 
the  United  States,  21,336  tons  bar,  and  7148  tons  pig.  The  largest  quantity  of 
unwrought  steel  has  been  to  the  latter  place— viz.  1336  tons. 

Of  British  hardware  and  cutlery,  we  exported  in  the  year  17,183  tons,  valued  at 
1,746,618/. ;  the  principal  of  which  has  been — to  Germany,  1237  tons,  value  169,889/. ; 
East  Indies,  1402  tons,  value  142,607/. ;  British  North  American  Colonies,  1129  tona, 
value  102,260/.;  British  West  Indies,  997  tons,  value  80,040/.;  Foreign  West  Indies, 
667  tons,  value  48,609/. ;  United  States,  4282  tons,  value  448,841/. ;  Brazil,  943  tons, 
value,  80,070/. ;  and  divers  other  places,  varying  from  100  to  500  tons. 

We  now  come  to  copper.  Of  foreign  copper  ores,  we  have  imported  55,720  tons , 
and  of  metallic  copper,  unwrought  and  wrought  plates,  and  coins,  805  tons.  Of  the 
ores,  the  greatest  quantities  have  come  from  Cuba  and  Chili. 

We  have  exported  1819  tons  of  British,  and  660  tons  of  foreign  tin — of  which 
France  has  taken  626  tons,  Russia  480  tons,  Italy  183  tons,  Turkey  250  tons,  and  the 
remainder  distributed  among  twenty-seven  places. 
Of  foreign  zinc,  we  have  imported  as  follows: — 

Countries  from  whence  imported.  Tons.  Cwt  Qrs.  Lbs. 

Denmark 268     19     2     21 

Prussia 6860     15     3     22 

Germany 3000       1     2     11 

I                  Holland 80821 

Jelgium             21       9     0      9 

Syria  and  Palestine 115015 

Total  import  of  foreign  zinc  -  Tons  10,173  4  3  23 
Of  this,  we  retained  for  home  consumption  4102  tons,  on  which  the  nett  duty  waa 
228/.  2«  lOd;  and  we  have  exported  1395  tons  of  British,  and  6445  tons  of  foreign  spelter. 
Of  foreign  lead,  we  have  imported  2663  tons— of  which  2776  tons  were  pig  and 
sheet,  68  tons  ore,  and  19  tons  white  lead;  157  tons  were  retained  for  home  con- 
sumption, on  which  the  duty  was  165/1;  and  we  imported  from  the  Isle  of  Man,  duty 
free,  2415  tons  of  lead  ore.  Our  exportation  of  foreign  lead  amounted  to  2439  tons- 
while  of  British,  we  exported,  176  tons  of  ore,  14,610  tons  pig  and  sheet  378  tona 
btharge,  707  tons  red  lead,  and  1224  tons  white  lead— making  a  total  of  17,097  ton^ 
— Railway  and  Commercial  Gazette,  May  18.  1844.  ^^ 

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I- 


It 

(2 


o  > 


e 
E 


a^ 

•9 


J- 


.» 


I     I     i     II 


1^     o     o     o  o  o 

W     >o     lo     o  o  o 

fH  fH  »H 

«^  s  s  s  s  s 


S8 


1^     »•     o     o     >e     00 

«      O      H|i      o      o«      o 

fH 

^      Kd      lO      lO      lO      h8i 


to 


^5     5?    00     ^  o? 

fH 

*      00      lO      o  o 

''I       fH       fH       fH  r^ 


«a 


I  i  I  i  I 
^  e'  2  ;^  s' 


00 
00 
Oi 
©» 


S2    S    S    2J     S 

-<i>      1(3      ^      p>      op 

^   S    th   s   s 


ot 


.  't  ©  e«  rH 

gS  >Q  0>  b>  <D 

o  <e  fH  fH  d 

O  fH  Olf  fH  O 

H  »H  fH  fH  fH 


if 

a 


O        rH 

»>        0»        .   . 

00       iO       rH 


H    ;^    S'    S    g    §' 


fH 

3 


do      oo      aa      m      OD 


I 


/ 


[136] 


METAIXIO  STATISTICS. 


METALLIC  STATISTICS. 


[187] 


ill 


Imports  of  Foreign  Copper  and  Copper  Ore  into  the  United  Kingdom  from  1882  to 

1849,  inclusiye. 


FRANCE. 


1^ 


' 


1882 
1838 
1894 
188& 
1886 
1887 
1888 
1839 
1840 
1841 
1842 
1848 
1844 
1845 
1846 
1847 
1848 
1849 


Copper 
nnwrought. 


Part 
r  rough  t. 


T.  ctqr.  lb.  T.  ct  qr.  lb. 


0      0    0    2  — 


0  0    2  15 

—           0  12    4 

0      1000  01  21 

0    10    0    0   0  1    1  23 

21    18    1  15  — 


94    14    0289      714 


PlaUMud 

Coin. 


I 


51' 


1884 

0 

9    8  15 

1885 

— 

1886 

0 

0    0  21 

188T 

1888 

*^ 

188d 

__ 

1840 

•..• 

1841 

-_ 

1842 

... 

1848 

._ 

1844 

— 

1845 

— 

1846 

__ 

1847 

^— 

1848 

0 

19    0 

184 

— 

0 
0 
0 
2 
0 
0 
0 


2  8  19 
1  8  11 
8  2  8 
11  8  8 
8  0  7 
2  8 
2  14 


15 
5 


0  2  28 
18  7 
6    2  23 

0  0  18 
10  9 
0    0    0 


18S8 
1884 
1886 

1886 

1887  13 

1888  41 
1880 
1840  4 
iML 
1848 
1848 
1844 
1845 
1846 
1847 
1848 
1848 


18 
1 

15' 
5 


0 
8 


1  19 
0  23 

8  20 
8  11 


2  14 
1  26 


9      0    0    0 


T. 
0 
0 
0 


0 
0 
0 
0 
0 
0 
0 
0 
0 


0 
0 
0 
0 
0 

0 
6 


ct  qr.  lb. 

0  0  2 

2  1  22 

0  0  10 


1 
0 
0 
0 
0 
0 
0 
0 
0 


0  11 

1  2 
1  i 
8  14 
0  15 

0  4 

1  14 
0  5 
0  14 

2  14 


0      2      8 


OU  for  remaaofiM- 
ture. 


T.  ct 

0  8 


qr.  lb. 
0  25 


2  7  2  2 


13 
13 

2 

9 

18 


8  12 

8  14 

1  5 

2  20 
1  4 


Or«. 


T.  Ct  qr.  lb 


0 
0 


0  0 

1  25 


9  a  1  14 

0  0  0  12 

0  2  1  19 

8  15  0  0 


118  4 
32  4 
45  6 


0  0 
0  12 
0  0 


Copper  maoufactarea. 


Weight.      I      Value. 


0  6    8    4 

1  18    2    2 


T.  ct  qr.lb.     £ 

—  2,268 

—  2,888 
2,845 
1,555 
2,287 

—  ,  6,914 

—  !  1,601 
0    0    6  2,548 

1,897 
1,780 
1,451 
1,986 
2,788 
2,818 
2,891 
8,069 
2,841 
2,704 


n  d. 

0    6 

18    6 

2  10 

0    6 


0 
4 

0 
0 


1    15    0  10 


0      114 


16 

16 

18 

19 

14  0 

8  6 

0  6 

6  6 

4  10 

18  11 

19  2 
2  7 

10  0 

18  0 


GERMANY. 


0    18 
0     c 


8    14 
0     1 


0      0      0    22 


0 
0 

0 
14 


8  18 

0  17 

0  18 

8  6 


1  25 

0  7 

8  12 

8  8 

0  10 

2  7 
2  18 


0  10 

1  8 


9 
4 
2 
5 

2  1 
0  19 
0      8 


2  12 

2  10 

8  5 

8  19 

2  14 

8  17 

2  6 

0  20 

8  21 


10 
12 
11 

18 
14 


0 
8 
0    24 


2    25 
8      6 


8 

2 

125 


8    2  25 

0    0  19 

18    0  27 


83    0    0    0 


0    10    0 


0 
5 

28 

12 

1 


4 

19 

2 

6 

4 


8  15 

10  17 

28  18 

12  14 

5  8 

6  6 

10  15 

11  14 
24  0 


8    8 

1  20 

2  0 
0  22 
2  19 

0  0 

1  7 
0  21 
8  20 

0  2 

1  16 

1  17 

2  21 
2  24 


ITALY. 


0      0 
0      0 


0  S 

1  88 


0      0      0    80  — 


0 
0 
0 
0 
0 

0 
0 


1  7 
8  80 

2  16 

0  8 

1  0 

1  5 

1  28 


0      8     8    14 


8    7    1  20 


16  11    2    2 


1 

0 
0 


8    0    6 

17    0  22 

4    19 


80  19  0  12 

102  18  1  14 

245  10  0  24 

824    9  1    4 

865  17  8  24;  2    14    0  17 

0      8     1    84  558  10  8    8   0    14    2    8 

«    «■" «      J^  ^1  2  14|  1    19    0    1 

0  11      3      8  576  16  2    2    1      6 
8    11      8    16  207    2  8    8 

1  18      1    18123    8  3    6 


10 


8    6 
1  18 


1,518 

2,161 

2,903 

2,061 

1,211 

1,866 

818 

827 

249 

667 

101 

204 

295 

402 

520 

l,ltt 


0 

4 
6 

2 
4 
2 


4 
10 
19 

5 
18 

8 
12    0 

2    6 
11    0 

7    6 

6    6 

0    0 

0    0 

4 

0 

6  11 


7 
8 
6 
9 

1 

24 
18 


8  0 
18  18 

1  19 
28    8 

159  0 
10  10 
58  12 
87    0 

180  0 
68    6 


0 

0 
0 
0 
0 
0 
0 
0 
0 
0 


0 
0 
6 
0 
0 

1 


Imports  of  Foreign  Copper  and  Copper  Ore — eoniinued. 


RUSSIA 


Year 

t 

C^per  MaaofiMtoree. 

emling 
Jan.  5. 

Copp*r 
nnwrought. 

Part 

wrought. 

Plates  and       Old,  for  r«ma- 
Coin,               nufactare. 

Ore. 

Weight 

Value. 

T.  ct  qr.  lb. 

T.  ct  qr.  lb.  T. 

ct  qr.  lb.  T.  ct  qr.  lb. 

T.  ct  qr.  lb. 

T.  ct  qr.  IK 

£     «.     dL 

1882 

— 

— 

_          ,  0    0    8  12 

— 

— 

— 

1888 

^.v 

.^K 

— 

— 

^ 

1884 

5    18    9 

0    0    0    0 



0    5    0    0 

0    0    0  18 

— 

— 

1885 

5    1    0  23 

26  19    1  18 

^ 

— 

— 

— 

7  10    0 

1886 

9    12    4 

16    1    1  14 

— 

— 

— 

— 

41  15    0 

1837 

0    0    8  22 

-_ 

— 

0    8    1  11 

— 

4    0    0 

1888 

__ 

_ 

0    0    8  20 

— 

— 

5    0    0 

1839 

— 

^ 

^ 

118    6 

— 

— 

— 

1840 

_ 

— 

^_ 

0    8    0  28 

— 

— 

^.^ 

1841 

— 

— 

^_ 

— 

— 

— 

8    0    0 

1842 

._ 

—. 

__ 

— 

^ 

— 

82    0    0 

1848 

^. 

^^ 

^^ 

0    0    2  24 

— 

— 

46  15    6 

1844 

8    4    18 

^^ 

0 

0    0    1 

18    0    7 

— 

0  17    0  16 

2  17    0 

1845 

^ 

_ 

_ 

^ 

96  15    0 

1846 

._ 

_ 

1 

6    8  14 

— 

— 

1  12    2  16 

62  10    0 

1847 

32    2    8    2 

_ 

__ 

0  12    8    4 

— 

— 

8    0    0 

1848 

_ 

... 

0    10    0 

— 

— 

14  15    0 

1849 

— 

__ 

8 

0    0    0 

on   1  24 

— 

""" 

8  10    0 

HOLLANTD. 


1884 

1886 
ia36 
1887 
1888 
1889 
1840 
1841 
1842 
1848 
1844 
1845 
1846 
1847 
184S 
1849 


0  0  0  7 
0  17  8  16 


1  14  8  7 


0  1  812 


0  0  1  12 


0  16 

1  8  28 
1  028 


0  1  0  18 


0  2  0  25 

0  0  0  4 

0  0  0  7 

0  0  014 

0  0*2  0 


0  2  0  1 
0  0  8  21 


0  0  8  0 


43  18  0  20 

57  8  0  0 

85  16  0  0 

88  0  0  0 

50  0  0  0 


_     40  6  0  0 


^_ 

90    1 

0    0 

^M 

13    5 

2    0 

..^ 

63  18 

2  14 

_ 

89  16 

325 

— 

110    5 

3  11 

0  13 

2 

9     2  12 

8    8 



1  76  10 

0    0 

19    8 

0  16 

10  10 

1    9 

4  5 

23  8 

9  2 

10  18 


1 

NORWAY. 

1S85 

0    8    15 

116    5    2  10 

1886 

__ 

„^ 

M^ 

_— 

507  11    0  18 

1887 

— . 

__ 

__ 

— 

182  17    1  16 

1838 

— 

^_ 

_. 

^~* 

— 

1839 

— 



_— 

— 

— 

1840 

_ 

.^ 

^^ 

0    4    2  17 

— 

1841 

^ 

_ 

78  17    0  11 

— 

57    8    2  14 

1842 

— 

^_ 

.— 

118    125 

- 

1843 

79    9    1  10 

—            60  10    0    6 

«. 

89    6    1    0 

1844 

— 

45  14    8  22   28  12    1    2 

«» 

5  10    1  20 

1845 

140    5    8    6 

—                                      .1. 

^^ 

8  18    1    9 

1846 

69    9    2  18 

—                                      MM 

«M. 

4    7    221 

1847 



69  19    0    4          -. 

«. 



1848 

82  17    8  27 

—                   __ 

0    0    2  19 

0    0    10 

1849 

— 

62  12    8  11 

— 

— 

— 

0 


23  17 
83  2 


15 
27 


32  12 
14  10 


8  25 

2  28 

0  16 

0  13 

0  20 

8  18 

2    5 

8    6 

0  15 

8    8 

0  10 

0    8 

8 

1 

69 

72 

24 

59 

100 

65 

512 

288 

114 

296 

670 

1,088 

821 

8,948 


0  0 

10  0 

0  0 

1  6 
19  6 

5  0  i 

0  0 
8  0 

8  0  ) 

6  0 
10  0 

6  0 

15  0 

17  0 

1  0 
12  6 


884  10  0 


I 


/ 


I 


ri38] 


METAT.TJO  STATISTICS. 


Quarterly  Sales  of  Copper  Ores  in  Cornwall  for  the  Six  Years  ending  the  Slat  of 

December,  1849. 


Qaarter  ending  March  31, 1844,  . . . . 

„  June  30, 1844, 

„  September  30, 1844, 

«  December  31, 1844, . 


Total,. 


Quarter  ending  March  31, 1845, 

„  June  80, 1845,  .... 

n  September  30, 1845, 

n  December  31, 1845,. 


Total,. 


Qaarter  ending  March  31, 1846, .... 

„  JuneSO,  1846, 

„  September  30,  1S46, 

„  December  31, 1846, 


Total,. 


Quarter  ending  March  81, 1847,  .... 

June3i>,  1847 

September  30, 1847, 
December  81, 1S47, 


w 

M 


Total, 


Quarter  ending  March  81, 1848, , 

„  Jnne80,1848, , 

„  September  80,  1848, , 

„  December  81, 1848, 


Total,. 


Quarter  ending  March  81, 1849,  . . . . 

„  JuneSO,  1849 

„  September  30, 1849, 

u  December  81, 1849,. 


Total,. 


ToQflL 

89,874 
87,806 
88,078 
87,716 


152,969 


40,367 
49,834 
42,420 
88,926 


162,557 


39,835 
82,282 
87,784 
85,079 


144,480 


88,071 
84,875 
40,174 
40,000 


153,120 


85,532 
87,905 
86,287 
85,972 


147,701 


86,093 
86,681 
87,108 
86,508 


146,335 


£       a.  a. 

219,019  8  0 

188,721  8  0 

195,626  17  6 

198,066  16  0 


801,484  4  ft 


215,284  8  0 

226,878  8  0 

250,257  1  6 

228,019  18  6 


919,934  6  9 


207,697  10  0 

200,810  11  6 

196,486  16  0 

191,197    9  0 


796,192    6    ft 


222,543    9  0 

204,662    4  6 

229,969    2  6 

216,263  14  0 


878,486  10    0 


202,517  9  0 

176,880  17  0 

164,409  10  6 

176,888  0  6 


720,090  17  0 


188,507    0  ft 

187,167  15  6 

194,495  11  ft 

198,444  11  ft 


763,614  19    0 


Quarterly  Sales  of  Copper  Ores  in  Cornwall  for  the  Year  1849. 


Quarter  ending. 

Ore  in  Toni 
of  21  CwU 

Fine  Copper. 

Amoont  of 
Money. 

ATorage  per 
Cent. 

ATerai^e 
Standard. 

Per  Too. 

March  81, 

Jane  80, 

86,093 

86,631 
87,108 
86,508 

2,981    11 
2,906    14 
2,992    17 
2,810      2 

£       8.  d. 

188,507    0    6 

187,167  15    6 
194,495  11    6 
198,444  11    6 

8i 
7» 

£    9.    d. 
98  12    0 

98  16    2 

97  14    1 

104  10  11 

£  9.d. 
5    4    5 

5    2    2 

5    4  10 

5    5    7 

September 80,  .... 
December  81, 

Total, 

146,835 

11,691      4 

763,614  19    0 

8 

99  18    8 

6    4    8 

METALLIC  STATISTICS. 

Importfl  of  Foreign  Copper  and  Copper  Ore^ Continued. 

SWEDEN. 


[139] 


Year 
ending 
Jan.  5. 


1832 
18:33 
1834 
1885 

ias6 

1837 

1883 

1839 

1840 

1841 

1842 

1843" 

1844 

1845 

1846 

1847 

1843 

1849 


CJopper 
on  wrought 


T.  ct.  qr.  lb 


Part 
wrought 


T.  Ct  qr.lb. 
0     0    1  17 


Plates  and 
Coin. 


Old  for  Ee- 
manu&ctnre. 


T.  ct  qr.  lb. 


T.  ct  qr.lb, 


Oro. 


11  14  2  11 

45  7  .  8  21 
277  11  2  8 
191  18  I  14 
126  6  0  8 

55  11    2  21 


2    0    0    6 


3      0    0  16 


1    19    8  27 


Ck>pper  Manulkctnres. 


Weight 


T.  ct  qr.  lb 
714  14  0  0 
866  6  0  82 
789  18  2  9 
685  0  8  10 
498  9  0  26 
1905  «  8  18 
1  16  2  8 1469  10  0  ,0 
718  15  2  11 
501  18  0  0 
28  10  0  0 
16  12  0  14 
0   6  18 


T.  ct  ^r.  lb. 


Value. 


10 


9.    d. 
0     0 


0     T    824 


2 
6 
0 


0  0 
0  0 
5     0 


SUMMARY. 

Imports  of  Copper  and  Copper  Ore  from  the  whole  of  Europe  into  the  United 
Kingdom,  from  1832  to  the  6th  of  January,  1849. 


Copper  nn- 
wrouebt  ID  Bricki 

or  PiKi,  Ro«e 

Copper  and  Catt 

Copper. 


Part  wroujfht 

Bars,  Rods  or  In- 

^tt,  hammered 

or  raised. 


Plate*  and  Coin. 


T.  ct  qr.  lb. 
•28  16  0  25 
8  11  0  26 
11  8  0  6 
27  0  1  16 
17  15  0  28 
884  17  2  18 
177  2  8  14 
55  7  8  21 
287  6  0  18 
162  4  8  25 
12ft  16  0  8 
141  8  8  2 
28  15  0  5 
140  14  1  4 
69  10  0  8 
44  9  0  1 
194  0  0  17 
105  14  1  1 


T.  ct  qr.  lb 
0  1  8  11 
0  4  10 
0  2  8  19 
28  6  0  1 
16  4  8  17 
4  16  1  7 
0  8  0  7 
0  16  0  23 
0  T  2  2 
0  0  1  21 
0  1  1  28 
0  0  2  83 
86  6  1  0 
0  8  1  18 
2  1  8  20 
70  19  0  22 
70  7  0  6 
7ft  1  2  14 


Old  fbrRemaan- 
facture. 


0 
0 
0 
0 
0 


T.  ct  qr.  lb. 
0  0  1  11 
0  8  10 
0  1ft  0  22 
0  0  0  22 
2  0  16 
0  0  1 
114 

0  8  18 

1  0  21 
74  0  1  26 

0  0  918 
50  10  2  12 
54  6  1  20 

1  16  2  4 
5  0  2  27 
0  18  0  2 

59  18  0  18 
7  0  10 


Ore. 


T.  ct  qr.lb. 

1  14  0  5 
5  11  2  24 

2  6  8  28 
2  18  7 
5  10  1  13 

7  6  8  12 

8  12  2  9 

1  12  1  18 
7  15  1  12 

2  8  2  8 
4  2  0  20 

0  16  8  11 
4  15  0  22 
6  10  8  11 

1  11  115 
8  11  0  8 
6  10  0  12 

28  11  0  14 


T.  ct  qr.  lb 
714  14  0  4 
400  4  2  16 
880  18  2  6 
851  10  8  24 
1065  9  1  21 
2178  16  2  25 
1522  0  2  1 
882  18  8  21 
582  17  2  21 
226  11  1  8 
885  4  8  7 
894  18  8  8 
672  18  8  0 
674  5  1  20 
860  18  2  26 
715  17  2  16 
816  6  2  5 
802  8  1  23 



Copper  Manufactures. 


Entered  by 
Weifrht 


T.  ct  qr.  lb. 


4  17  1  9 

81  18  2  28 

88  1  8  0 

28  8  2  16 

18  2  8 

8  15  0  0 

10  18  1  27 

81  19  0  11 

86  12  1  25 

41  17  0  18 
85  18  8  1 
49  11  0  15 
49  2  1  2 

42  16    1    0 


Enterod  by 
Value. 


£     ».    d. 
2,920    18    4 
4,589   16  10 
8.878    11  10 
8,739    14  10 
5,326     2    0 
8,081     0    0 
2,889   11    4 
4,002   17    2 
2,336     8    6 
2,190   18    0 
2,274   17    6 
2,888     0    0 
8,217     1    4 
2,990   18  11 
8,634   17    8 
4,689     9    7 
4,222   11    < 
8,076  11    6 


In  this  table  the  returns  are  also  made  up  for  the  years  1832-48. 


/ 


[140] 


METALLIC  STATISTICS. 


^ 


i 

6 


>aioooo«ee)»»aoio 


t- »- «P  O  O  00  :*  ^ 


o 


^ 


.-;  C^h^OS^O  t—  r->  oa 


5' 


■J 
S 

I 


a 

o 
H 


5 

« 

& 

■s 


E 


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METALLIC  STATISTICS. 

Account  of  Sales  of  Copper  Ores  in  Cornwall,  1849. 

FIBST  QUABTEB. 


tl41] 


DatoofSaU. 


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^  fi"S  en  C  a,  c-S  C 


^kOS^csMOSmpQS 


Janaarv  11  ... 
18.., 
25  ... 

Febraary  1  ... 
•»  8 


March 


24.... 

X      •  w   •  • 
V      •   •  •  • 

16  .... 
2S  .... 
29  .... 


Avenfra 

ATCrage 

Prio«. 

SUiuburd. 

Produce.  ' 

£     t.     d. 

£ 

«.  d. 

87   T  0 

8t 

4 

12  6 

84  12  0 
93  10  0 

?J 

5 

4 

9  0 
18  0 

95  16  0 

7i 

4 

6  0 

91  16  0 

9 

5 

10  0 

90   8  0 

91 

5 

18  6 

104   0  0 

7 

4 

10  6 

106  18  0 

8   • 

5 

14  6 

104  12  0 

8  J 

6 

5  6 

99   T  0 

H 

6 

18  0 

107   5  0 

U 

5 

1 

6  0 

Qnantity 
of  Or*. 


21  C5wt 
1,818 
2,638 
8,841 
8,988 
2,146 
2,990 
2,5&t 
8,684 
2,67T 
2,885 
8,665 


ToUl 


98    13    0  I      8i      I    5     4     5    <  86,098 


SECOND  QUARTER. 


Compated 
Qiuuitity  of 
fine  Ck>pper. 


Ton8.Cwt. 
152  18 
255 
804 
293 
192  19 
287  0 
178  14 
278 
281 
272 


Amonntof 

S*leB. 


8 
0 
0 


6 

2 

7 


276  10 


2,981  11 


£       «. 

8,876  18 
14,846  18 
17,874  10 
17,166  12 
11,819  1 
17,728  1 
11,535  16 
19,882  16 
16,818  1 
19,122  0 
19,598    6 


Value  of  Or«  | 
to  prodooe  on*: 
Ton  of  Copper. 


188,607    0  6 


£  «. 
54  15 
56  4 
58  16 
58  11 
61  5 
61  15 
6i  11 

71  6 

72  15 
70  4 
70  17 


d. 

8 
7 
0 
9 
1 
1 
1 
8 
6 
8 
7 


68    4    6 


April 


My 


June 


5.... 

106 

18 

0 

7 

r  I 

12  ... 

104 

14 

0 

8: 

19  .... 

99 

17 

0 

9 

26  .... 

112 

8 

0 

6 

8  ... 

105 

8 

0 

7 

10  .... 

100 

9 

0 

8 

17  .... 

98 

18 

0 

9 

24.... 

98 

5 

0 

I 

81  .... 

93 

1 

0 

7* 

7  .... 

90 

14 

0 

8 

21  .... 

86 

16 

0 

9 

28  .... 

99 

8 

0 

64 

M  .... 

98 

16 

2 

7-985 

5   6 

0 

8,942 

5  18 

0 

2,547 

6  16 

6 

2,741 

4  18 

6 

2,671 

5   6 

6 

8,791 

6   8 

6 

2,584 

6   7 

6 

2,398 

4   5 

0 

8,961 

4   9 

0 

8,948 

4  11 

0 

2,496 

5   2 

0 

2,929 

8  14 

0 

2,628 

5   2 

2 

86,681 

298  8 

20,907  8  6 

70  7  4 

210  12 

16,048  10  0 

71  9  1 

262  15 

18,699  8  6 

71  8  4 

176  5 

12.428  6  6 

70  9  9 

290  11 

20,206  0  0 

69  10  11 

210  19 

14,092  6  6 

66  16  1 

232  15 

16,278  11  0 

66  12  7 

281  7 

16,785  18  6 

59  9  8 

805  18 

17,612  1  0 

57  11  2 

201  7 

11,407  19  6 

56  13  2 

264  18 

14,916  18  0 

56  8  6 

170  19 

9,724  8  6 

56  17  8 

2.906  14 

187,167  15  6 

64  7  0 

THIRD  QUARTER. 


July 

5.... 

•i 

12  .... 

u 

19  .... 

u 

aO   •  ■  •  • 

August 

2  .... 

u 

9  .... 

u 

28  .... 

u 

80 

September  6  — 

ti 

18  ... . 

M 

20  .... 

« 

ST  ..«. 

96 

17 

0  . 

7t 

94 

9 

0 

6* 

91 

11 

0 

10 

100 

0 

0 

7- 

93 

14 

0 

7- 

95 

19 

0 

8* 

94 

1 

0 

9} 

108 

2 

0 

?l 

108 

3 

0 

108 

16 

0 

8. 

99 

17 

0 

9i 

106 

10 

0 

7* 

4 
5 
6      9 


13     0 
10     6 


Total....!     97    u    1  18-066 


0 

10  6 

8  0 

10  6 

2  6 

8    18  0 

5      8  0 

5  16  6 

6  14  0 
5     2  6 


4 
4 
5 
6 


6      4   10 


3,598 
2,638 
2,115 
8,628 
8,881 
2,595 
3,041 
2,977 
3,801 
2,6U 
2,467 
8,790 


274  6 
221  2 
212  14 
264  6 

280  15 
224  2 
296  19 
183  0 
800  10 
220  16 
233  0 

281  7 


87,108  1  2,992  17 


16,679 
18,918 
18,662 
16,473 
17,087 
14,863 
18,624 
11.599 
20,549 
15,663 
16,475 
19,554 


Oft 

50 

17  0 

4  6 

2  6 
0  6 
9  6 

15  6 
12  6 
15  6 

3  0 

5  6 


60  16  1 
62  18  6 
64  4  8 
62  6  7 
60  18  S 
64  1  10 
62  14  5 
68  2  8 

68  7  8 
70  9  9 
70  14  8 

69  10  0 


FOURTH  QUARTER. 


October  4  . 

«  11  . 

H  18  . 

"  25  . 

Noyemberl 

*»  8 

«  22 

«  29 

Decembers 
"  18 
•*  SO 
»         ST 

Total 


106 
102 
98 
110 
104 
102 


7  0 

7  0 
1  0 

8  0 
8  0 
1  0 


97  16  0 

108  0  0 

108  15  0 

104  18  0 

100  l3  0 

110  17  0 


104    10  11 


It 

?i 

n 

7 

n 

8 
9 
6> 


4 

6 


16 
1 


6    10 
4      0 


4 
5 


18 
11 


6    11 


4 
5 
5 
6 

4 


16 
2 

12 
7 

10 


0 

0 

6 

6 

6 

0 

0 

0 

6 

0 

0 

6 


7-696      5      5     7 


8,998 

1,926 

2,694 

2,718 

8,965 

2,677 

2,858 

4,220 

4,864 

2,887 

2,627 

2,879 


288  6 
164  19 
245  9 
166  7 
291  6 
209  5 
224  13 
293  16 
817  8 
229  8 
228  1 
156    4 


191,495  11  6 

64  19  9 

19,126  18  0 

67  10  8 

11,587  15  6 

70  6  0 

16.983  10  6 

69  0  8 

10,906  6  0 

65  11  8 

19,616  2  6 

66  19  11 

14,267  8  6 

68  8  8 

15,494  6  6 

68  19  5 

20,121  16  0 

68  9  9 

22,627  2  0 

70  19  6 

16,124  19  0 

70  5  10 

16,059  16  0 

70  8  5 

10,778  16  0 

68  19  6 

86,508  12,810    2 


198,444  11  6       68  16    9 

/ 


iWy^tfiW 


J*2]  METALLIC  STATISTICS. 

Produce  of  Lead  Ore  and  Lead  in  the  United  Kingdom,  for  the  Year  184& 
By  EoBKBT  Hunt,  Esq.,  Keeper  of  the  Mining  Records. 


METALLIC  STATISTICS. 


[143] 


Mines. 


Cornwall. 

Calington, 

Hael  Mary  Ann,  ... 
Huel  Trelawny  . . . . 

Hue!  Trebane 

Herodsfoot 

Eest  Huel  Rose  . . . . 
North  Huel  Rose... 

Cargol 

Oxnams 

Huel  Rose 

Cubert 

Holmbush 

Callestock 


Devonshire. 

Tamar 

Huel  Adams 

East  Tatnar  Cionsols 
Huel  Friendship  . . . 

Huel  Betsey 

Lydford  Consols 


Cumberland  and  Alston 
Moor. 

Rainngill 

Scaleourn, 

Carre  and  Hanging  Shaw  . 

Capel  Cieugh 

Small  Cieugh 

Middle  Cieugh 

Guddamgili 

Long  Cieugh 

Browngill 

Bentyfields  Veins 

Cowperdyke  Heads 

Brigalburn  Veins 

Brown  ley  Hill  Veins 

Bentfleld  Sun.  V.  K  Eng... 

Blagill  Veins 

Carrs  West  of  Nent  Vein  . . 

Grass  Fields  Veins 

Gallisill  Syke  Veins 

Gailigill  Burn 

Hndgill  Burn 

Holvfields  Veins 

Weflgill  Cross  Vein 

Rodderup  Cieugh  West  End 

Tyne  Bottom  Veins 

Park  Grove  Sun  Vein  . . . 

Low  Birchy  Bank 

Dowkeburn  West  End 

Sundry  mines  under  10  tons 
Drigjdih  Beck  Waste.... 

Dry  Mill  Mine 

Greensides 

Woodend 

Force  Cragg 

Keswick  Mine 

Slaty  Syke 

Calvert 

Dozey 

Slow  Craig , 

Crossfell  Mines , 

Sundry,  under  10  tons  .... 


Durluim  &  Northurnber- 
land. 

K    and  W.  Allendale  and 

Weardale 

Teesdale  Mines 

Yarnberry 

Silver  Tongue 

Derwent  Mines 

Stanhope  Burn 

Holly-well 

Lane  Head 

Alier  Gill 

Bollihope 

Fallow-deid 

Whitlicld 


Lead  Ore 
Returns. 


Tonsw 
957 
884 
413 
422 
721 
5,a38 

80 
964 
470 
899 

63 
154 
179 

1,022 

P6 

287 

9 

6 

4 


424 

288 

146 

139 

81 

80 

60 

1,664 

603 

85 

14 

241 

227 

119 

76 

89 

81 

176 

24 

188 

68 

98 

1,470 
80 
21 
19 
95 
44 
80 
40 

1,560 
86 
•43 
20 
47 
11 
18 
25 
44 
20 


13,230 

8,327 

100 

139 

1,4S0 

220 

67 

24 

12 

13 

61 

143 


Lead 
Retunu. 


Tona 

632 

250 

298 

279 

670 

3,191 

49 

677 

288 

239 

41 

90 

110 

631 
30 

173 
6 
8 
2 


282 
156 
97 
91 
21 
20 
83 
1,142 
400 
21 
9 
162 
143 
60 
51 
26 
20 
117 
16 
120 
38 
66 
980 
54 
14 
12 
68 
29 
15 
27 
1,200 
24 
82 
14 
35 
6 
9 
16 
30 
12 


9,0S0 

1,490 

75 

95 

1,046 

160 

48 

17 

8 

9 

45 

105 


&i 


net. 


Westmoreland. 
Dufton  and  Silverband. 
Hilton  and  Marton 

Derbyshire. 
Sundry  Mines 


Shropshire. 

Snail  Beach 

White  Grit  and  Batholea. 

Bog  Mine 

Pennerley 

Somersetshire. 
Mendip.Hills 


Yorkshire. 
Swale  Dale  and  Arkendale 

Cononley 

Grassington  and  Gambury 
I'ateley  District 


Cardiganshire. 

Lisbume  Mines 

Cwm-ystwy  th 

Esgair-hir 

Cwm-sebon 

Llanfair 

Goginan 

Gogerddan  Mines 

Nant-y-creiau 

Pen-y-bont-pren 

Cefb-cwm-brwyno 

Llwyn-malys 

Bwlch-cwm-erfln 

Bwlch  Consols 

Nanteos 

Aberysfrwith,  small  mines  . , 

Llanymaron , 

Llanbadarn , 

Bron-berllan , 


Carnarvonshire. 
Penrhyn-du  

Carmarthenshire. 
Nant-y-Mwyn 

Flintshire. 

Talargoch  

Fronfownog. 

Hendre  

Maes-y-Safn  

Pen-y-rhenblas 

Mold  Mines   , 

Long  Rake , 

Mllwr , 

Dingle  and  Deep  Level  . 

Pair's  Mine 

Trelogan 

Westminster  Mines 

HalkinHall  

Garreg-y-boeth 

Bodel  wyddan 

Belgrave 

Bryng-gwyrog 

Jamaica 

Bwlch-y-ddaufryn 

Gwern-y-mynydd 

Mostyn 

Bagillt  (ore  sold  at)  — 

Billings  

Caelanycraig 

Mostyu   

Clwtmilitia    


Montgomeryshire.  ... 

Llangynnog , 

Cae-conroy , 

Rhos-wydol , 

Dwn-gwm,  or  Dyfegnvm.! 

Craig-Uhiwarth  

Bryndaii  and  Pen-y-clyn  '. 
Gom 


Ma«!hynlleth,  includine 
Deljfe * 


Lead  Ore 
Re  tarns. 


Tons. 

246 
278 

6,185 

8,463 
606 
139 


41 

4,068 
699 

1.159 
987 

2,454 

120 

116 

81 

80 

1,288 

248 

17 

88 

86 

61 

40 

289 

60 

20 

11 

83 

15 

21 

807 

1,500 
1,695 
1,040 
1.18S 
1,160 

219 
89 

117 

8S7 

21 

15 

659 

89 
6 

106 
875 

11 
885 

20 

18 

18 

46 

46 

14 

12 

26 

61 
88 
26 
18 
27 
155 
43 

645 


Lead 
RetoRia. 


Tons. 
184 
204 

8,870 

2,486 

289 

72 

16 

29 

8,040 
437 
707 
609 

1,624 

71 

70 

17 

68 
816 
162 

10 

22 

24 

83 

26 
192 

80 

10 
6 

18 
7 

14 

804 

980 
1,168 
688 
824 
819 
153 
21 
81 
648 
15 
10 
451 
26 
4 
69 
261 
7 
699 
16 
18 
8 
20 
20 
7 
6 
11 

81 
20 
15 
9 
16 
100 
80 

800 


Mlaea. 


Montgomeryshire. 

Nantmelyn 

FrontbalUn 

Merionethshire. 

Cowarch 

Tyddynglwadus 

Ibklakd. 

Newtonards 

Conlig 

Shallee 

Glenmalure 

Lugitnure 

Barristown 


LeadOrs 

Lead 

Retuma. 

Returns- 

Tons. 

Tons. 

19 

13 

15 

7 

74 

42 

18 

12 

616 

866 

814 

179 

840 

202 

45 

89 

422 

295 

176 

116 

Mines. 


Lead  Ore 

Returns. 


Scotland. 

Woodhead 

Afton  Lead  Mines . . 
Stroniton  Mines.,.. 

Cairnsmore 

Black  Craig 

Lead  Hills  Mine.... 
Wanlock  Mine 


Isle  of  Max. 

Foxdale  Mines,  including  Peel's 

shipment,  6iC 

Laxey  

Douglas 


Retuma. 


Ton& 

Tons. 

460 

820 

80 

66 

286 

141 

476 

811 

86 

58 

800 

200 

960 

660 

,566 

1,084 

695 

461 

260 

ITO 

Table  showing  the  Total  Quantity  of  Lead  Ore  raised  and  Lead  smelted  in  the  United 

Kingdom  in  1848. 


Districts. 


Cornwall 

Devonshire 

Cumberland 

Durham  and  Northumberland 

Westmoreland 

Derbyshire 

Shropshire 

Somersetshire 

Yorkshire 

Walks  : — 

Cardiganshire 

Carnarvonshire  . . .  .• 

Carmarthenshire 

Flintshire 

Montgomeryshire 

Merionethshire 

Irblamd 

8cX)TLAin> 

Isle  ofMak 

Making  a  Total  of. 


Lead  Ore. 


Tons. 

10,494 

l,a34 

8,272  . 

18,815 

519 

5,185 

4,130 

41 

6,848 


55,633 


4,902 

21 

SOT 

10,056 

927 

92 


16,305 
1.912 

2,588 
2,521 

78,964 


Tons. 

6,614 

844 

5,684 

14,658 

888 

8,870 

2,769 

29 

4,798 


89,143 


S;180 

14 

904 

7,069 

601 

64 


11,123 
1,188 
1,786 
1,665 

54,858 


Lead  Ore  and  Lead  imported  and  exported  during  1848. 

Imported.— 1,^8  tons  of  lead  ore;  pig  and  sheet  lead,  8,788  tons:  retained  for  homo  consamption. 
2,157  tons.  ^ 

Rrportfd.—\^  tons  of  lead  ore:  pig  and  rolled  lead,  4,977  tons:  shot,  1,151  tons:  litharge,  red  and 
white  lead,  2,292  tons;  foreign  lead,  in  sheet  and  pig,  3,747  tons. 

The  Welsh  sales  include  also  the  following  lead  ores :— Australian,  69  tons;  Belgian,  85  tons:  German. 
44  tons;  Portugal,  79  tons;  Prussian,  112  tons;  Sardinian,  112  tons.  ^^ 

The  total  ainount  of  lead  ore  raised  and  sold  in  the  United  Kingdom,  for  the  year  1848,  was  78.964  tons, 
and  metallic  lead  sold  54,853  tons;  while  in  1847,  the  amount  of  lead  ore  was  79,311  ton*  and  lead  53,410 
tons— showing  a  decrease  in  the  quantity  of  ore  in  1848,  as  compared  with  a  former  year,  of  347  tons  but 
an  Increase  in  the  metal  of  1,443  tons. 

The  price  of  English  pig  at  the  close  of  1847  was  17/.  10«.  per  ton,  and  at  the  same  period  of  1848, 15t 
15«.  per  ton.  A  comparist)ii  of  the  two  years  thus  shows  no  very  great  fluctuation  in  home  trade :  but,  on 
referring  to  the  imports  mid  exports  we  And  a  great  increa-sj  in  the  latter  year.  The  imports  of  lead  ore 
in  1847  were  507  tons,  and  pig  and  sheet  lead  894  tons;  and  the  exports  86  tons  of  ore,  and  8,435  tons  of 
metal :  while  in  1848  the  imports  were  1,298  tons  of  ore,  and  3,788  tons  of  metal ;  and  the  exports  185  tons 
of  ore,  and  (),  128  tons  of  metal— showing  an  Increase  in  the  imports  of  791  tons  of  ore,  and  3,894  tons  of 
metal:  and  m  the  exyoria  of  49  tons  of  «.re,  and  2,693  tons  of  pig,  sheet  lead,  and  shot,  and  exclusive  of 
inanufacture<l  metal  in  the  shape  of  litharge  and  red  and  white  lead. 

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METALIJC  STATISTICS. 


CORNISH  COPPER  ORES. 


[146] 


Annual  average  Produce,  Price,  and  Standard  for  Nine  Years,  fi^>m  1841  to  1849, 
inclusive,  of  Copper  Ores  sold  at  Cornish  Ticketing,  with  the  highest  and  lowest 
Prices  of  Cake  Copper  in  each  Year. 


Year. 

Standard. 

Prodace. 

Prices 

Cake  Copper— per  Ton. 

£       a.    d. 

£    9.    d. 

££«.<!. 

1841 

125     1      0 

n 

6     5     0 

100  to  95      0      0 

1842 

113    18     0 

Tf 

5    12     1 

96  to  88     0      0 

1848 

109     8     0 

T» 

5    10     0 

88  to  78    10      0 

1844 

107     8     0 

7i 

6     4     9 

88  to  88      8      0 

1845 

106     2     0 

Ti 

6    18     0 

98  to  84     0      0 

1846 

102      2      0 

71 

5     6    10 

98  to  88    10      0 

1847 

108    11      0 

81 

5    14     1 

98  to  98      0      0 

1848 

90    18      0 

8  6-16 

4    18     9 

98  to  87      0     0 

1849 

99    18     8 

8 

6     4     8 

86  to  79    10      0 

Declared  Value  of  Exports  of  British  and  Irish  Metals  for  the  Years  ending  the  6th 

of  January,  1847,  1848,  1849,  and  1850. 


Iron  and  steel  

1847. 

1848. 

1849. 

1850. 

£ 

4,178,026 

1,558,187 

147,170 

107,456 

689,228 

£ 

5,265,779 

1,541,868 

179,844 

169,466 

462,889 

£ 

4,747,009 

1,272,675 

117,181 

148,486 

580,061 

£ 

4,966,978 

1,204,801 

287,887 

141,577 

711,649 

Copper  and  brass. 

Lead 

Tin,  anwrooght 

Tin  plates 

Exports  of  English  and  Irish  Metals  and  Minerals. 

The  following  particnlars  are  extracted  from  an  account  of  the  exports  of  the  principal  articles  of  Britiab 
and  Irish  produce  and  manofactores  in  the  twelve  months  ending  on  tiie  5th  of  January,  1846,1847,1848, 
1849,  and  1850. 


Coals,  enlm 

1846. 

1847. 

1848. 

1849. 

185a 

£ 

978,685 

828,183 

867,421 
2,168,000 

904,961 
8,501,895 
1,694^441 

210,974 

48,777 

615,729 

21  =,802       1 

£ 

9n,174 

793,166 

262,647 

2,180,587 

1,117,470 

4,178,026 

1,558,187 

147,170 

107,466 

639,228 

2(15,005 

£ 

976,877 

884,151 

292,088 

8,846,265 

1,228,091 

5,272,942 

1,467,498 

181,771 

159,098 

459,265 

260,591 

£ 

1,088,221 
722,012 
887,678 

1,860,150 
284,182 

4,777,965 

1,257,945 
115,547 
148,085 
582,142 
266,480 

£ 

1,088,148 
807,466 
277,175 

2,198,597 
154,707 

4,947,648 

1,868,287 
287,887 
141,577 
711,649 
254,126 

Earthenware 

Olaas 

Hardware,  entlery 

Machinery 

Iron,  steel 

Copper,  brass     

Lead 

Tin,  un wrought 

Tin  plates 

Salt 

18S;'48'?9llSlirl^'iS^^^^  '^'^^^^ '  *^  ^^^'  "•22^'^-  •  *^  ^^'  '^'^^'^^ '  *» 

Vol.  a 


[10] 


/ 


140 


METALLURGY. 


METALLURGY  (Erzkunde,  Germ.)  is  the  art  of  extracting  metals  from  their  oret. 
This  art,  which  supplies  industry  with  the  instruments  most  essential  to  its  wants,  is 
alike  dependant  upon  the  sciences  of  chemistry  and  mechanics ;  upon  the  former,  as 
directing  the  smelting  processes,  best  adapted  to  disentangle  each  metal  from  its  mineral 
izer ;  upon  the  latter,  as  furnishing  the  means  of  grinding  the  ores,  and  separating  the 
light  stony  parts  from  the  rich  metallic  matter. 

Notwithstanding  the  striking  analogy  which  exists  beiween  common  chemical  and 
metallurgic  operations,  since  both  are  employed  to  insulate  certain  bodies  from  others, 
there  are  essential  ditferences  which  should  be  carefully  noted.  In  the  first  place,  the 
quantity  of  materials  being  always  very  great  in  metallurgy,  requires  corresponding  adap- 
tations of  apparatus,  and  often  produces  peculiar  phenomena ;  in  the  second  place,  the 
agents  to  be  employed  for  treating  great  masses,  must  be  selected  with  a  view  to  economy, 
as  well  as  to  chemical  action.  In  analytical  chemistry,  the  main  object  being  exactness 
erf*  result,  and  purity  of  product,  little  attention  is  bestowed  upon  the  value  of  the  rea- 
gents, on  account  of  the  small  quantity  required  for  any  particular  process.  But  in 
smelting  metals  upon  the  great  scale,  profit  being  the  sole  object,  cheap  materials  and 
easy  operations  alone  are  admissible. 

The  metallic  ores  as  presented  by  nature,  are  almost  always  mixed  with  a  considerable 
number  of  foreign  substances ;  and  could  not  therefore  be  advantageously  submitted  to 
metaUurgic  operations,  till  they  are  purified  and  concentrated  to  a  certain  degree  bj 
various  methods. 

OF  THE  PREPABATION   OF  OKE8   FOR   THE  SMELTING   HOUSK. 

There  are  two  kinds  of  preparation ;  the  one  termed  mechanical,  from  the  means  em- 
ployed, and  the  results  obtained,  consists  in  processes  for  breaking  and  grinding  the  ores, 
and  for  washing  them  so  as  to  separate  the  vein-stones,  gangues,  or  other  mixed  earthy 
matters,  in  order  to  insulate  or  concentrate  the  metallic  parts. 

Another  kind  of  preparation,  called  chemical,  has  for  its  object  to  separate,  by  means 
of  fire,  various  volatile  substances  combined  in  the  ores,  and  which  it  is  requisite  to 
clear  away,  at  least  in  a  certain  degree,  before  trying  to  extract  the  metals  they  may 
contain. 

Lastly,  an  indispensable  operation  in  several  circumstances,  is  to  discover,  by  simple 
and  cheap  methods,  called  assays,  the  quantity  of  metal  contained  in  the  difi'erent  species 
of  ores  to  be  treated. 

This  head  of  our  subject,  therefore,  falls  under  three  subdivisions : — 

§  1.  The  mechanical  preparation  of  ores,  including  picking,  stamping,  and  different 
modes  of  washing. 

§  2.  The  chemical  preparation,  consisting  especially  in  the  roasting  or  calcination  of 
the  ores. 

§  3.  The  assay  of  ores,  comprehending  the  mechanical  part :  that  is,  by  washing;  the 
chemical  part,  or  assays  by  the  dry  way  ;  and  the  assays  by  the  moist  way. 

Section  1.  Of  the  mechanical  preparation  or  dressing  of  ores. — I.  The  first  picking  or 
sorting  takes  place  in  the  interior,  or  underground  workings,  and  consists  in  separating 
the  fragments  of  rocks,  that  apparently  contain  no  metallic  matter,  from  those  that  con- 
lain  more  or  less  of  it.  The  external  aspect  guides  this  separation  ;  as  also  the  feeling 
of  density  in  the  hand. 

The  substances,  when  turned  out  to  the  day,  undergo  another  sorting,  with  greater  or 
less  care,  according  to  the  value  of  the  included  metal.  This  operation  consists  in 
breaking  the  lumps  of  ore  with  the  hammer,  into  fragments  of  greater  or  less  size,  usually 
as  large  as  the  fist,  whereby  all  the  pieces  may  be  picked  out  and  thrown  away  that 
contain  no  metal,  and  even  such  as  contain  too  little  to  be  smelted  with  advantage. 
There  is,  for  the  most  part,  a  building  erected  near  the  output  of  the  mine,  in  which  the 
breaking  and  picking  of  the  ores  are  performed.  In  a  covered  galler}',  or  under  a  shed, 
banks  of  eaurth  are  thrown  up,  and  divided  into  separate  beds,  on  each  of  which  a  thick 
plate  of  cast  iron  is  laid.  On  this  plate,  elderly  workmen,  women,  and  children,  break 
the  ores  with  hand  hammers,  then  pick  and  sort  them  piece  by  piece.  The  matters  so 
treated,  are  usually  separated  into  three  parts ;  1.  the  rock  or  sterile  gangue,  which  is 
thrown  away ;  2.  the  ore  for  the  stamping  mill,  which  presents  too  intimate  a  mixture 
of  rock  and  metallic  substance  to  admit  of  separation  by  breaking  and  picking ;  and 
3.  the  pure  ore,  or  at  least  the  very  rich  portion,  called  the  sorted  mine  or  the  fat  ore. 
On  the  sorting  floors  there  remains  much  small  rubbish,  which  might  form  a  fourth 
snbdivision  of  ore,  since  it  is  treated  in  a  peculiar  manner,  by  sifting,  as  will  be  presently 
mentioned. 

The  distribution  of  fragments  more  or  less  rich,  in  one  class  or  another,  is  relative  to  the 
value  of  the  included  metal,  taking  into  account  the  expenses  necessary  for  its  extraciion. 


METALLURGY. 


U7 


Thus  in  certain  lead  mines,  pieces  of  the  gangues  are  thrown  away,  which  judged  by  the 
eye  may  contain  3  per  cent,  of  galena,  because  it  is  known  that  the  greater  portion  of 
this  would  be  lost  iii  the  washings  required  for  separating  the  97  parts  of  the  gangue, 
and  that  the  remainder  would  not  pay  the  expenses. 

II.  The  very  simple  operations  of  picking  are  common  to  almost  all  ores ;  but  there 
are  other  operations  requiring  more  skill,  care,  and  expense,  which  are  employed  in  their 
final  state  of  perfection  only  upon  ores  of  metals  possessing  a  certain  value,  as  those  of 
lead,  silver,  &c.     We  allude  to  the  washing  of  ores. 

The  most  simple  and  economical  washings  are  those  that  certain  iron  ores,  particularly 
the  alluvial,  are  subjected  to,  as  they  are  found  near  the  surface  of  the  ground  aggluti- 
nated in  great  or  little  pieces.  It  is  often  useful  to  clean  these  pieces,  in  order  to  pick  oat 
the  earthy  lumps,  which  would  be  altogether  injurious  in  the  furnaces. 

This  crude  washing  is  performed  sometimes  by  men  stirring  in  the  midst  of  a  stream 
of  water,  with  iron  rakes  or  shovels,  the  lumps  of  ore  placed  in  large  chests,  or  basins  of 
wood  or  iron. 

In  other  situations,  this  ^vashing  is  executed  more  economically  by  a  machine  called 
a  buddle  or  dolly-tub  by  our  miners.  A  trough  of  wood  or  iron,  with  a  concave  bottom, 
is  filled  with  the  ore  to  be  washed.  Within  the  tub  or  trough,  arms  or  iron  handles 
are  moved  round  about,  being  attached  to  the  arbor  of  a  hydraulic  wheel.  The  trough 
is  kept  always  full  of  water,  which  as  it  is  renewed  carries  off  the  earthy  matters,  diffused 
through  it  by  the  motion  of  the  machine,  and  the  friction  among  the  pieces  of  the  ore. 
When  the  washing  is  finished,  a  door  in  one  of  the  sides  of  the  trough  is  opened,  and  the 
current  removes  the  ore  into  a  more  spacious  basin,  where  it  is  subjected  to  a  kind  of 
picking.  It  is  frequently  indeed  passed  through  sieves  in  different  modes.  See  Lead  and 
Tin,  for  figures  of  huddles  and  dollies. 

III.  Stamping.  Before  describing  the  refined  methods  of  washing  the  more  valuable 
ores  of  copper,  silver,  lead,  &c.,  it  is  proper  to  point  out  the  means  of  reducing  them 
into  a  powder  of  greater  or  less  fineness,  by  stamping,  so  called  from  the  name  stamps  of 
the  pestles  employed  for  that  purpose.  Its  usefulness  is  not  restricted  to  preparing  the 
ores ;  for  it  is  employed  in  almost  every  smelting  house  for  pounding  clays,  charcoal, 
scoriae,  &c.      A  stamping  mill  or  pounding   machine,  fig.    903   consists  of  several 

moveable  pillars  of  wood  III, 
placed  vertically,  and  supported 
in  this  position  between  frames 
of  carpentry  k  k  k.  These  pieces 
are  each  armed  at  their  under  end 
with  a  mass  of  iron  m.  An  arbor 
or  axle  a  a,  moved  by  water,  and 
turning  horizontally,  tosses  up 
these  wooden  pestles,  by  means 
of  wipers  or  cams,  which  lay 
hold  of  the  shoulders  of  the  pes- 
tles at  n  /.  These  are  raised  in 
,  L   1.  1 —  succession,  and  fall  into  an  ob- 

long trough  below  m  m,  scooped  out  in  the  ground,  having  its  bottom  covered  either 
with  plates  of  iron  or  hard  stones.  In  this  trough,  beneath  these  pestles,  the  ore  to  be 
stamped  is  allowed  to  fall  from  a  hopper  above,  which  is  kept  constantly  full. 

The  trough  is  closed  in  at  the  sides  by  two  partitions,  and  includes  three  or  four  pes- 
tles ;  which  the  French  miners  call  a  battery.  They  are  so  disposed  that  their  ascent  and 
descent  take  place  at  equal  intervals  of  time. 

Usually  a  stamping  machine  is  composed  of  several  batteries  (two,  three,  or  four),  and 
the  arrangement  of  the  wipers  on  the  arbor  of  the  hydraulic  wheel  is  such  that  there  is 
constantly  a  like  number  of  pestles  lifted  at  a  time  j  a  circumstance  important  for  main- 
taming  the  uniform  going  of  the  machine. 

The  matters  that  are  not  to  be  exposed  to  subsequent  washing  are  stamped  dry,  that 
IS,  without  leadmg  water  into  the  trough  ;  and  the  same  thing  is  someUmes  done  with  the 
rich  ores,  whose  lighter  parts  might  otherwise  be  lost. 

Most  usually,  especially  for  ores  of  lead,  silver,  copper,  &c.,  the  trough  of  the  stamper 

IS  placed  in  the  middle  of  a  current  of  water,  of  greater  or  less  force ;  which,  sweeping 

A  ^^«  Pf  "^^?^  substances,  deposiles  them  at  a  greater  or  less  distance  onwards,  in  the 

Prt^learhX  ^"""^  ^'  ^'^  ^"'^^  '  ^^'^^^^'"^^"^  ^  ^'''  ^^'^^^>  ^  '"^^^  --P« 

.i.^"K^''l.*^!lf"'T,T  ^*»!,fi:»«««s  of  the  powder  depends  on  the  weight  of  the  pestles, 
the  height  of  their  fall  and  the  period  of  their  action  upon  the  ore;  but  in  the  stamped 
exposed  to  a  stream  of  water,  the  retention  of  the  matters  in  the  trough  is  longer  or 
shorter  according  to  the  facility  given  for  their  escape.  Sometimes  these  matter!  flow 
out  of  the  chest  oyer  its  edges,  and  the  height  of  the  line  they  must  surmount  lias  an 
influence  on  the  size  of  the  grain  j  at  other  times,  the  water  and  the  pounded  matter 


W^ 


II 


II 


II 


148 


METALLURGY. 


METALLURGY. 


Ut 


irhich  it  carries  off,  are  made  to  pass  through  a  grating,  causing  a  kind  of  siAing  at  th€ 
same  time.  There  are,  however,  some  differences  in  the  results  of  these  two  methods. 
Lastly^  the  quantity  of  water  that  traverses  the  trough,  as  well  as  its  velocity,  has  an 
influence  on  the  discharge  of  the  pounded  matters,  and  consequently  on  the  products  of 
the  stampers. 

The  size  of  the  particles  of  the  pounded  ore  being  different,  according  to  the  variable 
hardness  of  the  matters  which  compose  them,  suggests  the  means  of  classing  them,  and 
distributing  them  nearly  in  the  order  of  their  size  and  specific  gravity,  by  making  the 
water,  as  it  escapes  from  the  stamping  trough,  circulate  in  a  system  of  canals  called  a 
labyrinthy  where  it  deposites  successively,  in  proportion  as  it  loses  its  velocity,  the  earthy 
and  metallic  matters  it  had  floated  along.  These  metalliferous  portions,  especially  when 
they  have  a  great  specific  gravity  like  galena,  would  be  deposited  in  the  first  passages, 
were  it  not  that  from  their  hardness  being  inferior  to  that  of  the  gangue,  they  are  reduced 
to  a  much  finer  powder,  or  into  thin  plates,  which  seem  to  adhere  to  both  the  watery  and 
earthy  particles  ;  whence  they  have  to  be  sought  for  among  the  finest  portions  of  the  pul- 
verized gangue,  called  slime,  schlich,  or  schlamme. 

There  are  several  methods  of  conducting  the  stamps;  in  reference  to  the  size  of  the 
grains  wished  to  be  obtained,  and  which  is  previously  determined  agreeably  to  the 
nature  of  the  ore,  and  of  the  gangue ;  its  richness,  &c.  The  height  of  the  slit  that 
lets  the  pounded  matters  escape,  or  the  diameters  of  the  holes  in  the  grating,  their  distance, 
the  quantity  of  water  flowing  in,  its  velocity,  &c.,  modify  the  result  of  the  stamping  oper- 
ation. 

When  it  is  requisite  to  obtain  powder  of  an  extreme  fineness,  as  for  ores  that  are  to  be 
subjected  to  the  process  of  amalgamation,  they  are  passed  under  millstones,  as  in  common 
com  mills ;  and  after  grinding,  they  are  bolted  so  as  to  form  a  species  of  flour ;  or  they 
are  crushed  between  rolls.    See  Lead  and  Tin. 

Washing  of  ores. 

TV,  The  ores  pounded  under  the  stamps  are  next  exirased  to  very  delicate  operations, 
both  tedious  and  costly,  which  are  called  the  washings.  Their  purpose  is  to  separate 
mechanically  the  earthy  matters  from  the  metallic  portion,  which  must  therefore  have  a 
much  higher  specific  gravity ;  for  otherwise,  the  washing  would  be  impracticable. 

The  medium  employed  to  diminish  the  difference  of  specific  gravity,  and  to  move  along 
the  lightest  matters,  is  water ;  which  is  made  to  flow  with  greater  or  less  velocity  and 
abundance  over  the  schlich  or  pasty  mud  spread  on  a  table  of  various  inclination. 

But  as  this  operation  always  occasions,  not  only  considerable  expense,  but  a  certain 
loss  of  metal,  it  is  right  to  calculate  what  is  the  degree  of  richness  below  which  washing 
is  unprofitable ;  and  on  the  other  hand,  what  is  the  degree  of  purification  of  the  schlich  at 
which  it  is  proper  to  stop,  because  too  much  metal  would  be  lost  comparatively  with  the 
expense  of  fusing  a  small  additional  quantity  of  gangue.  There  cannot,  indeed,  be  any 
fixed  rule  in  this  respect,  since  the  elements  of  these  calculations  vary  for  every  work. 

Before  describing  the  different  modes  of  washing,  we  must  treat  of  the  sifting  or 
riddling,  whose  purpose,  like  that  of  the  labyrinth  succeeding  the  stamps,  is  to  distribute 
and  to  separate  the  ores  (which  have  not  passed  through  the  water  stamps)  in  the  order 
of  the  coarseness  of  grain.  This  operation  is  practised  particularly  upon  the  debris  of 
the  mine,  and  the  rubbish  produced  in  breaking  the  ores.  These  substances  are  put  into 
a  riddle,  or  species  of  round  or  square  sieve,  whose  bottom  is  formed  of  a  grating  instead 
of  a  plate  of  metal  pierced  with  holes.  This  riddle  is  plunged  suddenly  and  repeatedly 
into  a  tub  or  cistern  filled  with  water.  This  liquid  enters  through  the  bottom,  raises  up 
the  mineral  particles,  separates  them  and  keeps  them  suspended  for  an  instant,  after 
which  they  fall  down  in  nearly  the  order  of  their  specific  gravities,  and  are  thus  classed 
with  a  certain  degree  of  regularity.  The  sieve  is  sometimes  dipped  by  the  immediate 
effort  oC  the  washer ;  sometimes  it  is  suspended  to  a  swing  which  the  workman  moves ; 
in  order  that  the  riddling  may  be  rightly  done,  the  sieve  should  receive  but  a  single 
movement  from  below  upwards ;  in  this  case  the  ore  is  separated  from  the  gangue,  and 
if  there  be  different  specific  gravities,  there  are  formed  in  the  sieve  as  many  distinct  strata, 
which  the  workman  can  easily  take  out  with  a  spatula,  throwing  the  upper  part  away 
when  it  is  too  poor  to  be  re-sifted.  This  operation  by  the  hand-sieve,  is  called  riddling 
m  the  iitbj  or  riddling  by  deposite. 

We  may  observe,  that  during  the  sifting,  the  particles  which  can  pass  across  the  holes 
of  the  bottom,  fall  into  the  tub  and  settle  down  there ;  whence  they  are  afterwards  gath* 
ered  out,  and  exposed  to  washing  when  they  are  worth  the  trouble. 

Sometimes,  as  at  Poullaouen,  the  sieves  are  conical,  and  held  by  means  of  two  handles 
by  a  workman  ;  and  instead  of  receiving  a  single  movement,  as  in  the  preceding  method^ 
the  sifter  himself  gives  them  a  variety  of  dexterous  movements  in  succession.  His  object 
is  to  separate  the  poor  portions  of  the  ore  from  the  richer ;  in  <»tler  to  subject  the  former 
to  the  stamp  mill. 

Among  the  sittings  and  washings  which  ores  are  made  to  undergo,  we  must  notice  as 


among  the  most  usefhl  and  ingenious,  those  practised  by  iron  gratings,  called  on  tlie  Con- 
tinent grilhs  anglaises,  and  the  step-washings  of  Hungary,  laveries  a  gradins.  These 
methods  of  freeing  the  ores  from  the  pulverulent  earthy  matters,  consist  in  placing  them, 
at  their  out-put  from  the  mine,  upon  gratings,  and  bringing  over  them  a  stream  of  water, 
which  merely  takes  down  through  the  bars  the  small  fragments,  but  carries  off  the  pulver- 
ulent portions.  The  latter  are  received  in  cisterns,  where  they  are  allowed  to  rest  long 
enough  to  settle  to  the  bottom.  The  washing  by  steps  is  an  extension  of  the  preceding 
plan.  To  form  an  idea,  let  us  imagine  a  series  of  grates  placed  successively  at  different 
levels,  so  that  the  water,  arriving  on  the  highest,  where  the  ore  for  washing  lies,  carries 
off  a  portion  of  it,  through  this  first  grate  upon  a  second  closer  in  its  bars,  thence  to  a 
third,  &c.,  and  finally  into  labjrrinths  or  cisterns  of  deposition. 

The  grilles  anglaises  are  similar  to  the  sleeping  tables  used  at  Idria.    The  system  of  these 
tn  gradins  is  represented  in^g.  904.    There  are  5  such  systems  in  the  works  at  Idria,  for 


904 


the  sorting  of  the  small  morsels  of  quicksilver  ore,  intended  for  the  stamping  mill.  These 
fragments  are  but  moderately  rich  in  metal,  and  are  picked  up  at  random,  of  various  sizes, 
from  that  of  the  fist  to  a  grain  of  dust. 

These  ores  are  placed  in  the  chest  a,  below  the  level  of  which  7  grates  are  distributed, 
so  that  the  fragments  which  pass  through  the  first  6,  proceed  by  an  inclined  conduit  on  to 
the  second  grate  c,  and  so  in  succession.  (See  the  conduits  2,  o,  p).  In  front,  and  on  a 
level  with  each  of  the  grates  6,  c,  d,  &c.,  a  child  is  stationed  on  one  of  the  floors,  1,  2  3, 
to  7. 

A  current  of  water,  which  falls  into  the  chest  a,  carries  the  fragments  of  ore  upon  the 
grates.  The  pieces  which  remain  upon  the  two  grates  6  and  c,  are  thrown  on  the  adjoin- 
ing table  r,  where  they  undergo  a  sorting  by  hand;  there  the  pieces  are  classified,  1.  into 
gangue  to  be  thrown  away  ;  2.  into  ore  for  the  stamp  mill ;  3.  into  ore  to  be  sent  directly 
to  the  furnace.  The  pieces  which  remain  on  each  of  the  succeeding  grates,  d,  €,/,  g,  h, 
are  deposited  on  those  of  the  floors  3  to  7,  in  front  of  each.  Before  every  one  of  these 
shelves  a  deposite-sieve  is  established,  (see  /,  «,)  and  the  workmen  in  charge  of  it  stand 
in  one  of  the  corresponding  boxes,  marked  8  to  12.  The  sieve  is  represented  only  in  front 
of  the  chest  h,  for  the  sake  of  clearness. 

Each  of  the  workmen  placed  in  8,  9,  10,  11,  12,  operates  on  the  heap  before  him;  the 
upper  layer  of  the  deposite  formed  in  his  sieve,  is  sent  to  the  stamping  house,  and  the  in- 
ferior layer  directly  to  the  furnace. 

As  to  the  grains  which,  after  traversing  the  five  grates,  have  arrived  at  the  chest  x, 
they  are  washed  in  the  two  chests  y,  which  are  analogous  to  the  German  chests  to  be 
presently  described.  The  upper  layer  of  what  is  deposited  in  y  is  sent  to  the  furnace ; 
the  rest  is  treated  anew  on  three  tables  of  percussion,  similar  to  the  English  brake-sieves^ 
also  to  be  presently  described. 

After  several  successive  manipulations  on  these  tables,  an  upper  stratum  of  schlich  is 
obtained  fit  for  the  furnace ;  an  intermediate  stratum,  which  is  washed  anew  by  the  same 
process ;  and  an  inferior  strattun,  that  is  sent  to  the  system  of  stamps,  ^g.  905. 
905 


This  figure  represents  the  general  ground  plan  of  a  stamping  and  washing  mill.  The 
Mamps  F  are  composed  of  two  batteries  similar  to^g.  903.  The  ore  passes  in  succession 
ander  three  pestles  of  cast  iron,  each  of  which  is  heavier  the  nearer  it  is  to  the  sieve 
through  which  the  sand  or  pounded  matter  escapes. 

In  the  upper  part  of  the  figure  we  see  issuing  from  the  stamps,  two  conduits  destined 
to  receive  the  water  and  the  metalliferous  sand  with  which  it  is  loaded.  The  first,  marked 
r.  s,  tr,  is  used  only  when  a  certain  quality  of  ore  is  stampedy  richer  in  metal  than  is 

/ 


160 


METALLURG\. 


METALLURGY. 


151 


II 


It    1^ 

I 


asuaUy  treated  by  means  of  the  second  conduit,  the  first  being  closed.  The  second  eo» 
duit,  or  that  employed  for  ordinary  manipulation  when  the  other  is  shut,  is  indicated  by 
r,  0'7,  B  ;  then  by  0*58  and  0-29.  These  numbers  express  the  depth  of  the  corresponding 
portions  of  this  conduit.  From  f  to  b,  the  conduit  or  water-course  is  divided  into  three 
portions  much  shallower,  called  the  rich  conduity  the  middle  conduit^  and  the  inferior 
Beyond  the  basin  b,  the  conduit  takes  the  name  of  labyrinth.  There  the  muddy  sedi: 
ments  of  ore  are  deposited ;  being  the  finer  the  further  they  are  from  the  stamps  r. 
Darts  indicate  the  direction  of  the  stream  in  the  labyrinth.  On  the  German  chestsj  placed 
at  3,  the  sand  derived  from  the  rich  and  middle  conduits  is  treated,  in  order  to  obtain 
three  distinct  qualities  of  achlich,  as  already  mentioned,  p  is  a  cloth-covered  table,  for 
treating  the  deposite  of  the  German  chests  at  3.  m  n  are  two  sweep  tables  Id  batai\  for 
treating  the  ore  collected  in  the  lower  conduit,  which  precedes  the  midmost  of  the  three 
German  chests.  Upon  the  three  similar  tables  k  t  v,  are  treated  in  like  manner  the  muddy 
deposites  of  the  labyrinth,  which  forms  suite  to  three  parallel  German  chests  situated  at  3, 
not  shown  for  want  of  room  in  the  figure,  but  connected  in  three  rectangular  zigzags 
with  each  other,  as  well  as  by  a  transverse  branch  to  the  points  0*7  and  p.  At  the  upper 
part  of  these  five  sweep  tables,  the  materials  which  are  to  undergo  washing  are  agitated 
in  two  boxes  o  o,  by  small  paddle-wheels. 

We  shall  now  describe  the  percussion-tables  used  in  the  Hartz,  for  treating  the  sand  of 
ore  obtained  from  the  conduits  represented  above. 

Figs.   906.  907.   and  908,  exhibit  a  plan,  a  vertical  section,  and  elevation,  of  one 

of  these  tables,  taken  in  the 
direction  of  its  length.  The 
arbor  or  great  shaft  in  prolonga- 
tion from  the  stamps  mill,  is 
shown  in  section  perpendicularly 
to  its  axis,  at  a.  The  cains  or 
wipers  are  shown  round  its  cir- 
cumference, one  of  them  having 
just  acted  on  w. 

These  cams,  by  the  revolu- 
tion of  the  arbor,  cause  the 
alternating  movements  of  a 
horizontal  bar  of  wood  o,  «, 
which  strikes  at  the  point  u 
against  a  table  rf,  6,  e,  u.  This 
table  is  suspended  by  two  chains 
ty  at  its  superior  end,  and  by 
two  rods  at  its  lower  end. 
After  having  been  pushed  by 
the  piece  o,  «,  it  rebounds  to 
strike  against  a  block  or  bracket 
B.  A  lever  p,  q,  serves  to  adjust 
the  inclination  of  the  moveable 
table,  the  pivots  q  being  points 
of  suspension. 

The  ore-sand  to  be  washed, 
is  iilaced  in  the  chest  a,  into 
which  a  current  of  water  runs. 
The  ore  floated  onwards  by  the 
water,  is  carried  through  a 
sieve  on  a  sloping  small  table 
Xf  under  which  is  concealed 
the  higher  end  of  the  moveable 
table  rf,  by  c,  u ;  and  it  thence 
falls  on  this  table,  diffusing  itself 
uniformly  over  its  surface.  The 
particles  deposited  on  this  table 
form  an  oblong  talus  (slope) 
upon  it;  the  successive  per- 
cussions that  it  receives,  deter- 
mine the  weightier  matters,  and 
consequently  those  richest  in 
metal,  to  accumulate  towards 
its  upper  end  at  u.  Now  the 
workman  by  means  of  the  lever 
p,  raises  the  lower  end  d  a  little 
in  order  to  preserve  the  sam<; 


degree  of  inclination  to  the  surface  on  which  the  deposite  is  «;trewed.  According  as  the 
substances  are  swept  along  by  the  water,  he  is  careful  to  remove  them  from  the  middle 
of  the  table  towards  the  top,  by  means  of  a  wooden  roller.  With  this  intent,  he  walks  on 
the  table  dbcuy  where  the  sandy  sediment  has  sufficient  consistence  to  bear  him.  When 
the  table  is  abundantly  charged  with  the  washed  ore,  the  deposite  is  divided  into  three 
bands  or  segments  db,bCyCU.  Each  of  these  bands  is  removed  separately  and  thrown 
into  the  particular  heap  assigned  to  it.  Every  one  of  the  heaps  thus  formed  becoinei 
afterwards  the  object  of  a  separate  manipulation  on  a  percussion  table,  but  always  accord- 
ing  to  the  same  procedure.  It  is  sufficient  in  general  to  pass  twice  over  this  table  the  mat- 
ters contained  in  the  heap,  proceeding  from  the  superior  band  c  u,  in  order  to  obtain  a  pure 
$chlich ;  but  the  heap  proceeding  from  the  intermediate  belt  6  c,  requires  always  a  greater 
number  of  manipulations,  and  the  lower  band  d  b  still  more.  These  successive  manipu- 
lations are  so  associated  that  eventually  each  heap  furnishes  pure  schlichy  which  is  obtained 
from  the  superior  band  c  u.  As  to  the  lightest  particles  which  the  water  sweeps  away 
beyond  the  lower  end  of  the  percussion  table,  they  fall  into  conduits ;  whence  they  are 
lifted  to  undergo  a  new  manipulation. 

Fig.  909  is  a  profile  of  a  plan  which  has  been  advantageously  substituted,  in  the 
Hartz,  for  that  part  of  the  preceding  apparatus  which  causes  the  jolt  of  the  piece  o  « 
against  the  table  dbcu.  By  means  of  this  plan,  it  is  easy  to  vary,  according  to  the 
circumstances  of  a  manipulation  always  delicate,  the  force  of  percussion  which  a  bar 
X  y,  ought  to  communicate  by  its  extremity  y.  With  this  view,  a  slender  piece  of  wood 
u  is  made  to  slide  in  an  upright  piece,  v  x,  adjusted  upon  an  axis  at  v.  To  the  piece  « 
a  rod  of  iron  is  connected,  by  means  of  a  hinge  z  ;  this  rod  is  capable  of  entering  more 
or  less  into  a  case  or  sheath  in  the  middle  of  the  piece  v  x,  and  of  being  stopped  at  the 
proper  point,  by  a  thumb-screw  which  presses  against  this  piece.  If  it  be  wished  to 
increase  the  force  of  percussion,  we  must  lower  the  point  z  ;  if  to  diminish  it,  we  must 
raise  it.    In  the  first  case,  the  extremity  of  the  piece  tt,  advances  so  much  further  under 

910 

909 


911 


the  cam  of  the  driving  shaft  / ;  in  the  second,  it  goes  so  much  less  forwards ;  whereby 
the  adjustment  is  produced. 

Figs.  910  and  911  represent  a  complete  system  of  sleeping  tables^  tables  dormantes ; 

—  such     as    are     mounted    in    Idria. 

Fig.  911  is  the  plan,  and  fig.  910  a 
vertical  section.  The  mercurial  ores, 
reduced  to  a  sand  by  stamps  like 
those  of  fig.  905  pass  into  a  series 
of  conduits  a  Oybby  c  c,  which  form 
three  successive  floors  below  the  level 
of  the  floor  of  the  works.  The  sand 
taken  out  of  these  conduits  is  thrown 
into  the  cells  q ;  whence  they  are 
transferred  into  the  trough  «,  and 
water  is  run  upon  them  by  turning 
two  stopcocks  for  each  trough.  The 
sand  thus  diffused  upon  eaclk  table, 
runs  off  with  the  water  by  a  groove  /,  comes  upon  a  sieve  h,  spreads  itself  upon  the 
board  g,  and  thence  falls  into  the  slanting  chest,  or  sleeping  table  i  k.  The  under  surface 
k  of  this  chest  is  pierced  with  holes,  which  may  be  stopped  at  pleasure  with  wooden 
plugs.  There  is  a  conduit  wi,  at  the  lower  end  of  each  table,  to  catch  the  light  par- 
ticles carried  off  by  the  water  out  of  the  chest  t  fc,  through  the  holes  properly  opened, 
while  the  denser  parts  are  deposited  upon  the  bottom  of  this  chest.  A  general  conduit 
n  passes  across  at  the  foot  of  all  the  chests  ik;  it  receives  the  refuse  of  the  washing 
operations. 

JFtg.  912  is  a  set  of  stamping  and  washing  works  for  the  ores  of  argentiferous  galena, 
as  mounted  at  Bockunese,  in  the  district  of  Zellerfeldt,  in  the  Hartz. 
A  is  the  stamp  mill  and  its  subsidiary  parts ;  among  which  are  a,  the  driTing  or 

/ 


152 


METALLURGY. 


maia  shaft ;  b,  the  overshot  water-wheel ;  c  c,  six  strong  rings  or  hoops  of  cast  iron. 


for 


receiving  each 
912 


a  cam  or  tappet ;  g,  the  brake  of  the  machine ;  fe,  /c,  k,  the  three 
standards  of  the  stamps ;  /  /,  &.c.  six  pestles  of  pine 
wood,  shod  with  lumps  of  cast  iron.  There  are 
two  chests,  out  of  which  the  ore  to  be  ground  falls 
spontaneously  into  the  two  troughs  of  the  stamps. 
Of  late  years,  however,  the  ore  is  mostly  supplied 
by  hand ;  the  water-course  terminates  a  short  dis- 
tance above  the  middle  of  the  wheel  b.  There  is 
a  stream  of  water  for  the  service  of  the  stamps, 
and  conduits  proceeding  from  it,  to  lead  the  water 
into  the  two  stamp  troughs ;  the  conduit  of  dis- 
charge is  common  to  the  two  batteries  or  sets  of 
stamps  through  which  the  water  carries  ofl'  the 
sand  or  stamped  ore.  There  is  a  moveable  table 
of  separation,  mounted  with  two  sieves.  The 
sands  pass  immediately  into  the  conduit  placed 
upon  a  level  with  the  floor,  and  separated  into 
two  compartments,  the  first  of  which  empties  its 
water  into  the  second.  There  are  two  boards  of 
separation,  or  tables,  laid  upon  the  ground,  with 
a  very  slight  slope  of  only  15  inches  from  their 
top  to  their  bottom.  Each  of  these  boards  is 
divided  into  four  cases  with  edges;  the  whole 
being  arranged  so  that  it  is  possible,  by  means  of 
a  flood-gate  or  sluice,  to  cause  the  superfluous 
water  of  the  case  to  pass  into  the  following  ones. 
Thus  the  work  can  go  on  without  interruption, 
and  alternately  upon  the  two  boards.  There  are 
winding  canals  in  the  labyrinth,  n,  n,  n,  in  which 
are  deposited  the  particles  carried  along  by  the 
water  which  has  passed  upon  the  boards.  The  depth 
of  these  canals  gradually  increases  from  12  to  20 
inches,  to  give  a  suitable  descent  for  maintaining 
the  water-flow.  At  d,  two  percussion  tables  are 
placed.  F  G  are  two  German  chests,  h  j  are  two 
percussion  tables,  which  are  driven  by  the  cams  z  z, 
fixed  upon  the  main  shaf\  xy.  k  k'  are  two  sloping 
sweep  tables  (<i  balai). 

The  German  chests  are  rectangular,  being 
about  3  yards  long,  half  a  yard  broad,  with  edges 
half  a  yard  high;  and  their  inclination  is  such 
that  the  lower  end  is  about  15  inches  beneath 
the  level  of  the  upper.  At  their  upper  end, 
usually  called  the  bolster,  a  kind  of  trough  or 
box,  without  any  edge  at  the  side  next  the  chest,  is  placed,  containing  the  ore  to  be  washed. 
The  Avater  is  allowed  to  fall  upon  the  bolster  in  a  thin  sheet. 

The  sleeping  tables  have  upright  edges ;  they  are  from  4  to  5  yards  long,  nearly  2  yards 
wide,  and  have  fuUy  a  yard  of  inclination. 

The  preceding  tables  are  sometimes  covered  with  cloth,  particularly  in  treating  ores 
that  contain  gold,  on  a  supposition  that  the  woollen  or  linen  fibres  would  retain  more 
surely  the  metallic  particles  ;  but  this  method  appears  on  trial  to  merit  no  confidence,  for 
it  produces  a  very  impure  schlich. 

Fig.  913  is  a  swing-sieve  employed  in  the  Hartz,  for  sifting  the  small  fragments  of 
the  ore  of  argentiferous  lead.    Such  an  apparatus  is  usually  set  up  in  the  outside  of 

a  stamp  and  washing  mill;  its  place  being  denoted 
by  the  letter  a,  in^g.  906.  The  two  moveable  chests  or 
boxes  A  B,  of  the  sieve,  are  connected  together,  at  their, 
lower  ends,  with  an  upright  rod,  which  terminates  at 
one  of  the  arms  of  a  small  balance  beam,  mounted  be- 
tween the  driving  shaft  of  the  stamps  and  the  sieve, 
perpendicularly  to  the  length  of  both.  The  opposite 
arm  of  this  beam  carries  another  upright  rod,  which 
ears  (cams  or  mentownets),  placed  on  purpose  upon  the 


ment  the 
rod  which 


"''iiiiiiiiiiiiitttiitMiMii'iiil.|yi]iiiiii| 
two  lower  ends  a, 


driving  shaft,  may  push  down.       During  this  move- 
B,  are  raised ;  and  when  the  peg-cam  of  the  shaft  quits  the 
it  had  depressed,  the  swing  chests  fall  by  their  own  weight.    Thus  thev 


METALLURGY. 


153 


are  made  to  vibrate  alternately  upon  their  axes.  The  small  ore  is  put  into  the  upper 
part  of  the  chest  a,  over  which  a  stream  of  water  falls  from  an  adjoining  conduit.  The 
Pigments  which  cannot  pass  through  a  cast  iron  grid  in  the  bottom  of  that  chest  arc 
sorted  by  hand  upon  a  table  in  front  of  a,  and  they  are  classed  by  ^^e  workman  either 
among  the  ores  to  be  stamped,  whether  dry  or  wet,  or  among  the  rubbish  to  be  thro^ 
^ay,  or  among  the  copper  ori  to  be  smelted  by  themselves.  As  to  the  small  p«u:ticle, 
which  faU  through  the  grid  upon  the  chest  b,  supplied  also  with  a  stream  ol  water,  tney 
descend  successively  up^n  two  other  brass  wire  sieves,  and  also  through  the  iron  wire  r, 

^"iVcertLiTm'in^  of  the  Hartz,  tables  called  H  balais,  or  sweeping  tables,  are  employed. 
The  whole  of  the  process  consists  in  letting  flow,  over  the  sloping  table,  m  successive 
currents,  water  charged  with  the  ore,  which  is  deposited  at  a  less  or  greater  distance,  as 
also  pur^  water  for  the  purpose  of  washing  the  deposited  ore,  afterwards  earned  ofl  by 
means  of  this  sweeping  operation.  •.  .^  :„   « 

At  the  upper  end  of  these  sweep-tables,  the  matters  for  washing  are  agitated  in  a 
chest,  bv  a  small  wheel  with  vanes,  or  flap-boards.  The  conduit  of  the  muddy  watere 
opens  above  a  Uttle  table  or  shelf;  the  conduit  of  pure  water,  which  adjoms  the  preceding, 
opens  below  it.  At  the  lower  part  of  each  of  these  tables,  there  is  a  transverse  slit,  cov- 
ered by  a  small  door  with  hinges,  opening  outwardly,  by  falling  back  towards  the  foot  ol 
the  table.  The  water  spreading  over  the  table,  may  at  pleasure  be  let  into  this  sUt,  by 
raisin''  a  bit  of  leather  which  is  nailed  to  the  table,  so  as  to  cover  the  smaU  door  when  it 
is  in  the  shut  position;  but  when  this  is  opened,  the  piece  of  leather  then  hangs  dowa 
into  it.  Otherwise  the  water  may  be  allowed  to  pass  freely  above  the  leather,  when  the 
door  is  shut.  The  same  thing  may  be  done  with  a  sinular  opening  placed  above  the  con- 
duit. By  means  of  these  two  slits,  two  distinct  qualities  of  schlich  may  be  obtained,  whictt 
are  deposited  into  two  distinct  conduits  or  canals.  The  refuse  of  the  opeTation  is  tumea 
into  another  conduit,  and  afterwards  into  ulterior  reservoirs,  whence  it  is  lifted  out  to  ua- 
dereo  a  new  washing.  .  .  .      , , 

In  the  percussion  tables,  the  water  for  washing  the  ores  is  sometimes  spread  m  slender 
streamlets,  sometimes  in  a  full  body,  so  as  to  let  two  cubic  feet  escape  per  minute.  1  he 
number  of  shocks  communicated  per  minute,  varies  from  15  to  36 ;  and  the  table  may  be 
pushed  out  of  its  settled  position  at  one  time,  three  quarters  of  an  inch,  at  another  nearly 
8  inches.    The  coarse  ore-sand  requires  in  general  less  water,  and  less  slope  of  table,  than 

the  fine  and  pasty  sand.  i      .  .u  •     .  ♦  «.,» 

The  mechanical  operations  which  ores  undergo,  take  place  commonly  at  their  out-put 
from  the  mine,  and  without  any  intermediate  operation.  Sometimes,  however,  the  hard- 
ness of  certain  gangues  (vein-stones),  and  of  certain  iron  ores,  is  diminished  by  subjecUng 
them  to  calcination  previously  to  the  breaking  and  stamping  processes. 

When  it  is  intended  to  wash  certain  ores,  an  operation  founded  on  the  difference  ot  their 
specific  gravities,  it  may  happen  that  by  slightly  changing  the  chemical  state  of  the  sub- 
stances  that  compose  the  ore,  the  earthy  parts  may  become  more  easily  separable,  as  also 
the  other  foreign  matters.  With  this  view,  the  ores  of  tin  are  subjected  to  a  roasting, 
which  by  separating  the  arsenic,  and  oxydizing  the  copper  which  are  intermixed,  !urnish€S 
the  means  of  obtaining,  by  the  subsequent  washing,  an  oxyde  of  tin  much  purer  than  could 
be  otherwise  procured.  In  general,  however,  these  are  rare  cases ;  so  that  the  washing 
almost  always  immediately  succeeds  the  picking  and  stamping ;  and  the  roasting  comes 
next,  when  it  needs  to  be  employed.  ,    •    i    *    .v 

The  operation  of  roasting  is  in  general  executed  by  various  processes,  relatively  to  the 
nature  of  the  ores,  the  quality  of  the  fuel,  and  to  the  object  in  view.  The  greatest 
economy  ought  to  be  studied  in  the  fuel,  as  well  as  the  labor ;  two  most  important  cir- 
cumstances, on  account  of  the  great  masses  operated  upon. 

Three  principal  methods  may  be  distinguished ;  1.  the  roasting  in  a  heap  in  the  open 
air,  the  most  simple  of  the  whole ;  2.  the  roasting  executed  between  little  walls,  and 
which   may  be  called    case-roasting    {rost-sladeln,  in  German);    and    3.   roasting  in 

furnaces.  . 

We  may  remark,  as  to  the  description  about  to  be  given  of  these  different  processes, 
that  in  the  first  two,  the  fuel  is  always  in  immediate  contact  with  the  ore  to  be  roasted, 
whilst  in  furnaces,  this  contact  may  or  may  not  take  place. 

1.  The  roasting  in  the  open  air,  and  in  heaps  more  or  less  considerable,  is  practised 
upon  iron  ores,  and  such  as  are  pyritous  or  bituminous.  The  operation  consists  in  general 
in  spreading  over  a  plane  area,  often  bottomed  with  beaten  clay,  billets  of  wood  arranged 
like  the  bars  of  a  gridiron,  and  sometimes  laid  crosswise  over  one  another,  so  as  to  form  a 
uniform  flat  bed.  Sometimes  wood  charcoal  is  scattered  in,  so  as  to  fill  up  the  interstices, 
and  to  prevent  the  ore  from  falling  between  the  other  pieces  of  the  fuel.  Coal  is  also 
employed  in  moderately  small  lumps ;  and  even  occasionally  turf.  The  ore,  either  simply 
broken  into  pieces,  or  even  sometimes  under  the  form  of  ^rhlich,  is  piled  up  over  the  fuel| 
most  usually  alternate  beds  of  fuel  and  ore  are  formed. 

/ 


<  *i 


154 


METALLURGY. 


..1,^*^  '  kindled  in  general  at  the  lower  part,  but  sometimes,  however,  at  the  middle 
^ney,  spreads  from  spot  to  spot,  putting  the  operation  in  train.  The  combustion 
whnL  '°  conducted  as  to  be  slow  and  suffocated,  to  prolong  the  uslulation,  and  let  the 
whole  mass  be  equably  penetrated  with  heat.  The  means  employed  to  direct  the  fire, 
are  to  cover  outwardly  with  earth  the  portions  where  too  much  activity  is  displayed 
and  to  pierce  with  holes  or  to  give  air  to  those  where  it  is  imperfectly  developed.  Rains 
^ni '•  T'^  ^^I'u""'  ^"'^  especiaUy  good  primary  arrangements  of  a  calcination,  have 
Se  betknin''*'^  ''"      '  ^'"'*''^'''  '^^'''^  requires,  besides,  an  almost  incessant  inspection  at 

its^Sv^  i'l  wT ^^  ''^^Ik^I"^^^  *'  ^^.  ^^^  consumption  of  fuel,  because  it  varies  with 
Its  quabty,  as  weU  as  with  the  ores  and  the  purpose  in  view.  But  it  may  be  laid  down 
as  a  good  rule,  to  employ  no  more  fuel  than  is  strictly  necessary  for  the  kind  of  calci- 
nation in  band,  and  for  supporting  the  combustion;  for  an  excess  of  fuel  would  produce 
oesides  an  expense  uselessly  incurred,  the  inconvenience,  at  limes  very  serious,  of  such 
UStuktLn"^^  ""^  ""^'"^^  *^^  ''^^^'  *  '^^"^^^  entirely  the  reverse  of  a  weU-conducted 

^igS'  914,  915,  916,  represent  the  roasting  in  mounds,  as  practised  near  Goslar  in  the 


pMiiiiim 


Hartz,  and  at  Cliessy  in  the  department  of  the  Rhone.    Fig.  914  is  a  vertical  section 

mo^^h^^  '  lf/%  ?;^  ^^^  ^^^' ,  ^"  •^^-  ^^^  ^^^'^  '^  «^°^«  i«  Pl«n^  only  a  little 
F?.  01  r  r^  r.?f  '^^  quadrangular  truncated  pyramid,  which  constitutes  the  heap, 
i^ig.  916  shows  a  little  more  than  one  fourth  of  a  bed  of  wood,  arranged  at  the  bottom 
of  the  pyramid,  as  shown  by  a  a,  Jig  914  and  c  g  h,  fig.  916  c  is  a  wooden  chimney, 
"    "  formed  within  the  heap  of  ore,  at  whose  bottom  e 

there  is  a  little  parcel  of  charcoal ;  rf  d  are  large 
lumps  of  ore  distributed  upon  the  wooden  pile 
"-"'*  *  ^  ^^^  smaller  fragments,  to  cover  the  larger; 
/  /  IS  rubbish  and  clay  laid  smoothly  in  a  slope 
over  the  whole,  g,  fig.  916  a  passage  for  air 
left  under  the  bed  of  billets;  of  which  there  is 
a  similar  one  in  each  of  the  four  sides  of  the  base 
a  a,  so  that  two  principal  currents  of  air  cross  under 
the  upright  axis  c  c,  of  the  truncated  pyramid  indi- 
cated inj^g.  914. 

The  kindling   is  thrown  in   by  the  chimney  c. 
The  charcoal  c,  and  the  wood  a  a,  take  fire ;  the 
sulphureous  ores  d  e  f  wre  heated  to  such  a  high 
T^«ror.  iTo.*        1,  r^u-    1  .  J        temperature  as  to  vaporize  the  sulphur.    In  the 

o    J'?^*^'  ^  ^^P  ?.^*j^»s  ^»"d  continues  roasting  during  four  months.  *    ^"  ^«^ 

.t.n*  Z  T-  '?!I,^'*^- ,  ?^^  ^^"^^"^^y  ""^  managing  the  fire  in  the  roasting  of  sub- 
stances containing  li  le  sulphur,  with  the  greater  difficulty  of  arranging  and  suppor Un^ 
m  their  place  the  schhchs  to  be  roasted,  and  last  of  all,  the  necessitv  of  |ivin?  successivS 
fires  to  the  same  ores,  or  to  inconsiderable  quantities  at  a  time,  have'led  to  the  contrivanc^ 
of  surrounding  the  area  on  which  the  roasting  takes  place  with  three  little  wallsVor  wiS 
four,  leaving  a  door  in  the  one  m  front.  This  is  what  is  called  a  walled  area  and  sX 
times  improperly  enough,  a  roasting  furnace.  Inside  of  these  little  wainCt  3  Set' 
high  there  are  often  vertical  conduits  or  chimneys  made  to  correspond  wiihaSonenini 
on  the  ground  level,  in  order  to  excite  a  draught  of  air  in  the  adjacent  part  When  Ee 
roasting  IS  once  set  agoing,  these  chimneys  can  be  opened  or  shut  at  ?heir  upper  ends  ac 
cording  to  the  necessities  of  the  process.  ^^         "^»  ■*^* 

Several  such  furnaces  are  usually  erected  in  connexion  with  each  other  bv  their  lateral 
waUs,  and  aU  terminated  by  a  common  wall,  which  forms  their  posterLr  pm     somet  m^ 

'i    The  furnaces  employed  for  roasting  the  ores  and  the  matte,  differ  much,  according 


METALLURGY. 


155 
We  shall  content  ourselves  with 


to  the  nature  of  the  ores,  and  the  size  of  the  lumps 

referrin"  to  the  principal  forms.  ,  .       .      ^     ,.  

When  iron  ores  are  to  be  roasted,  which  require  but  a  simple  calcination  to  disengage 
the  combined  water  and  carbonic  acid,  egg-shaped  furnaces,  similar  to  those  in  which 
Umestone  is  burned  in  contact  with  fuel,  may  be  conveniently  employed;  and  they  pie- 
sent  the  advantage  of  an  operation  which  is  continuous  with  a  never-coolmg  apparatu^ 
The  analogy  in  the  effects  to  be  produced  is  so  perfect,  that  the  same  furnace  may  be 
used  for  either  object.  Greater  dimensions  may,  however,  be  given  to  those  destined  lor 
the  calcination  of  iron  ores.  But  it  must  be  remembered  that  this  process  is  applicable 
only  to  ores  broken  into  lumps,  and  not  to  ores  in  grains  or  powder. 

It  has  been  attempted  to  employ  the  same  method  a  little  modified,  for  t^e  roasting  of 
ores  of  sulphuret  of  copper  and  pyrites,  with  the  view  of  extracting  a  part  of  thesulphur 
More  or  less  success  has  ensued,  but  without  ever  surmounting  all  the  obstacles  arising 
from  the  great  fusibility  of  the  sulphuret  of  iron.  For  sometimes  it  runs  into  one  mass, 
or  at  least  into  lumps  agglutinated  together  in  certain  parts  of  the  furnace,  and  the  opera- 
tion  is  either  stopped  altogether,  or  becomes  more  or  less  languid ;  the  air  lot  bemg  able 
to  penetrate  into  all  the  parts,  the  roasting  becomes  consequently  unperfeci.  This  incon- 
venience is  even  more  serious  than  might  at  first  sight  appear ;  for,  as  the  ill-roasted  ores 
now  contain  too  little  sulphur  to  support  their  combustion,  and  as  they  sometimes  lall 
into  small  fragments  in  the  cooling,  they  cannot  be  passed  again  through  the  same  furnace, 
and  it  becomes  necessaiy  to  finish  the  roasting  in  a  reverberatory  hearth,  which  is  much 

""Yn  th'e^Pyrenees,  the  roasting  of  iron  ores  is  executed  in  a  circular  furnace,  so  disposed 
that  the  fuel  is  contained  and  burned  in  a  kind  of  interior  oven,  above  which  lie  the 
pieces  of  ore  to  be  calcined.  Sometimes  the  vault  of  this  oven,  which  sustams  i»^^  o^, 
is  formed  of  bricks,  leaving  between  them  openings  for  the  passage  of  the  flame  and  the 
smoke,  and  the  apparatus  then  resembles  certain  pottery  kilns  ;  at  other  limes  the  vau« 
is  formed  of  large  lumps  of  ore,  carefully  arranged  as  to  the  intervals  requisite  to  be  left 
for  draught  over  the  arch.  The  broken  ore  is  then  distributed  above  this  arch,  care  being 
taken  to  place  the  larger  pieces  undermost.  This  process  is  simple  in  the  construction 
of  the  furnace,  and  economical,  as  branches  of  trees,  without  value  in  the  forest,  may  be 
employed  in  the  roasting.    See  Lime-kiln  figures.  . 

In  some  other  countries,  the  ores  are  roasted  in  furnaces  very  like  those  in  which 
porcelain  is  baked  ;  that  is  to  say,  the  fuel  is  placed  exteriorly  to  the  body  of  the  furnace 
in  a  kind  of  brick  shafts,  and  the  flame  traverses  the  broken  ore  with  which  the  furnace 
is  filled.     In  such  an  apparatus  the  calcination  is  continuous. 

When  it  is  proposed  to  extract  the  sulphur  from  the  iron  pyrites,  or  from  pyritous  min- 
erals, different  furnaces  may  be  employed,  among  which  that  used  in  Hungary  desery^ 
notice.  It  is  a  rectangular  parallelopiped  of  four  walls,  each  of  them  being  perforated 
with  holes  and  vertical  conduits  which  lead  into  chambers  of  condensation,  where  the 
sulphur  is  collected.  The  ore  placed  between  the  four  walls  on  billets  of  wood  arranged 
as  in  figs.  914, 915,  916,  for  the  great  roastings  in  the  open  air,  is  calcined  with  the  dis- 
enea-ement  of  much  sulphur,  which  finds  more  facility  in  escaping  by  the  lateral  conduits 
in  the  walls,  than  up  through  the  whole  mass,  or  across  the  upper  surface  covered  over 
with  earth  ;  whence  it  passes  into  the  chambers  of  condensation.  In  this  way  upwards 
of  a  thousand  tons  of  pyrites  may  be  roasted  at  once,  and  a  large  quantity  of  sulphur 

obtained. — See  Coppek.  , .  ,    ,       i.        -, 

Roasting  of  Pyrites,— Figs.  917,  918,  represent  a  furnace  which  has  been  long  ero- 
^  -^      *  *  ployed  at    Fahlun  in    Sweden,  and 

917  tt^^S  several  other  parts  of  that  kingdom, 

f         el^^H  for  roasting  iron  pyrites  in  order  to 

obtain  sulphur.     This  apparatus  was 

constructed  by  the  celebrated  Gahn. 

Fig.  911  is  a  vertical  section,  in  the 

line  fc  d  n  0  of  fig.    918   which   is 

a  plan  of  the  furnace ;  the  top  being 

supposed  to  be  taken  off.     In  both 

figures  the  conduit  may  be  imagined 

to  be    broken   off   at  e;   its    entire 

length  in  a  straight   line  is  43  feet 

beyond  the  dotted  line,  e  n,  before  the  bend,  which  is  an  extension  of  this  conduit.    Upon 

the  slope  a  6  of  a  hillock  a  be,  lumps  r  of  iron  pyrites  are  piled  upon  the  pieces  ot  wooa 

t »  for  roasting.     A  conduit  df  e  forms  the  continuation  of  the  space  denoted  by  r,  wmcn 

is  covered  by  stone  slabs  so  far  as/;  and  from  this  point  to  the  chamber  h  it  is  constructea 

in  boards.      At  the  beginning  of  this  conduit,  there  is  a  recipient  g.      The  chamber /i  is 

divided  into  five  chambers  by  horizontal  partitions,  which  permit  the  circulation  ol  ine 


\> 


i\ 


/ 


156 


METALLURGY. 


vapors  from  one  compartment  to  another.  The  ores  r  being  distributed  upon  the  biUct^ 
of  wood  1 1,  whenever  these  are  fairly  kindled,  they  are  covered  with  smaU  ore,  and  then 
with  rammed  earth  I  L  Towards  the  point  m,  for  a  space  of  a  foot  square,  the  ores  are 
covered  with  moveable  stone  slabs,  by  means  of  which  the  fire  may  be  regulated,  by  the 
displacement  of  one  or  more,  as  may  be  deemed  necessary.  The  liquid  sulphur  runs  into 
the  recipient  g,  whence  it  is  laded  out  from  lime  to  time.  The  sublimed  sulphur  passes 
into  the  conduit  /  e  and  the  chamber  A,  from  which  it  is  taken  out,  and  washed  with 
water,  to  free  it  from  sulphuric  acid,  with  which  it  is  somewhat  impregnated :  it  is  after- 
wards distilled  in  cast-iron  retorts.  The  residuum  of  the  pyrites  is  turned  to  account  in 
Sweden,  for  the  preparation  of  a  common  red  color  much  used  as  a  pigment  for  wooden 
Diiildings. 

The  reverberatory  furnace  affords  one  of  the  best  means  of  ustulation,  where  it  is 
requisite  to  employ  the  simultaneous  action  of  heat  and  atmospherical  air  to  destroy 
certain  combinations,  and  to  decompose  the  sulphurets,  arseniurels,  &c.  It  is  likewise 
evident  that  the  facility  thus  offered  of  stirring  the  matters  spread  out  on  the  sole,  in 
order  to  renew  the  surfaces,  of  observing  their  appearances,  of  augmenting  or  diminish- 
ing the  degree  of  heat,  &c.,  promise  a  success  much  surer,  a  roasting  far  better  executed, 
than  by  any  other  process.  It  is  known,  besides,  that  flame  mingled  with  much  unde- 
composed  air  issuing  from  the  furnace,  is  highly  oxydizing,  and  is  very  fit  for  burning 
away  the  sulphur,  and  oxydizing  the  metals.  Finally,  this  is  almost  the  only  method  of 
rightly  roasting  ores  which  are  in  a  very  fine  powder.  If  it  be  not  employed  constantly 
and  for  every  kind  of  ore,  it  is  just  because  more  economy  is  found  in  practising  calcina- 
tion m  heaps,  or  on  areas  enclosed  by  walls;  besides,  in  certain  mines,  a  very  great  num- 
ber of  these  furnaces,  and  many  workmen,  would  be  required  to  roast  the  considerable 
body  of  ores  that  must  be  daily  smelted.  Hence  there  would  result  from  the  construction 
of  such  apparatus  and  its  maintenance  a  very  notable  outlav,  which  is  saved  in  the  other 
processes. 

But  in  every  case  where  it  is  desired  to  have  a  very  perfect  roasting,  as  for  blende  from 
which  zinc  IS  to  be  extracted,  for  sulphuret  of  antimony,  &c.,  or  even  for  ores  reduced  to 
a  very  fine  powder,  and  destined  for  amalgamation,  it  is  proper  to  perform  the  operation 
m  a  reverberatory  furnace.  When  very  fusible  sulphurous  ores  are  treated,  the  workman 
charged  with  the  calcination  must  employ  much  care  and  experience,  chiefly  in  the  man- 
agement of  the  fire.  It  will  sometimes,  indeed,  happen,  that  the  ore  partially  fuses ; 
when  It  becomes  necessary  to  withdraw  the  materials  from  the  furnace,  to  let  them  cool 
and  grind  them  anew,  in  order  to  recommence  the  operation.  The  construction  of  these 
furnaces  demands  no  other  attention  than  to  give  to  the  sole  or  laboratory  the  suitable 
size,  and  so  to  proportion  to  this  the  grate  and  the  chimney  that  the  heating  may  be 
eliected  with  the  greatest  economy. 

The  reverberatory  furnace  is  always  employed  to  roast  the  ores  of  precious  metals,  and 
especially  those  for  amalgamation ;  as  the  latter  oflen  contain  arsenic,  antimony,  and  other 
volatile  substances,  they  must  be  disposed  of  in  a  peculiar  manner. 

The  sole,  usually  very  spacious,  is  divided  into  two  parts,  of  which  the  one  farthest 
off  from  the  furnace  is  a  little  higher  than  the  other.  Above  the  vault  there  is  a  space 
or  chamber  in  which  the  ore  is  deposited,  and  which  communicates  with  the  laboratory 
by  a  vertical  passage ;  which  serves  to  allow  the  ore  to  be  pushed  down,  when  it  is  dried 
and  a  little  heated.  The  flame  and  the  smoke  which  escape  from  the  sole  or  laboratory 
pass  into  condensing  chambers,  before  entering  into  the  chimney  of  draught,  so  as  to 
deposite  in  them  the  oxyde  of  arsenic  and  other  substances.  When  the  ore  on  the  part 
of  the  sole  farthest  from  the  grate  has  suflTered  so  much  heat  as  to  begin  to  be  roasted 
has  become  less  fusible,  and  when  the  roasting  of  that  in  the  nearer  part  of  the  sole  is 
completed,  the  former  is  raked  towards  the  fire-bridge,  and  its  ustulation  is  finished  by 
stirring  it  over  frequently  with  a  paddle,  skUfully  worked,  through  one  of  the  doors  left 
in  the  side  for  this  purpose.  The  operation  is  considered  to  be  finished  when  the  vapors 
and  the  smell  have  almost  wholly  ceased;  its  duration  depending  obviously  on  the  nature 
of  the  ores. 

When  this  furnace  is  employed  to  roast  very  arsenical  ores,  as  the  tin  ores  of  Schlack- 
enwald  in  Bohemia,  and  at  Ehrenfriedensdorf  in  Saxony,  the  arsenical  pyrites  of  Geyer 
(in  Saxony),  &c.,  the  chambers  of  condensation  for  the  arsenious  acid  are  much  more 
extensive  than  in  the  furnaces  commonly  used  for  roasting  galena,  copper  or  even  silver 
ores.  ' 

Figs.  919,  920,  921,  represent  a  reverberatory  furnace  employed  in  the  smelting 
works  of  Lautenthal,  in  the  Hartz,  for  roasting  the  schlichs  of  lead  ores,  which  contain 
much  blende  or  sulphuret  of  zinc.  In  fig.  919  we  see  that  the  two  parts  a  b,  b  c,  are 
absolutely  like,  the  two  furnaces  being  built  in  one  body  of  brickwork.  Fig.  920  is 
the  plan  of  the  furnace  b  c,  taken  at  the  level  e  f  of  ^ig.  919.  Fig.  9*21  is  a'vcrtical 
section  of  the  similar  furnace  a  b,  taken  in  the  prolongation  of  the  line  g  h  in 
fig.  920. 


METALLURGY. 


157 


a  is  the  fire-place  of  the  furnace,  its  grate  and  ash-pit.    b  is  the  conduit  of  vaporiza- 
tion, wliich  communicates  with  the  chambers  c ;  c,  chambers  into  which  the  vaporized 


919 


920 


A  B  C 

substances  are  deposited ;  d,  chimney  for  4he  escape  of  the  smoke  of  the  fire  place  a, 
sJler  it  has  gone  through  the  space  be  c ;  e',  is  the  charging  door,  with  a  hook  hanging 

in  front  to  rest  the  long  iron  rake  upon,  with  which 
the  materials  are  turned  over ;  /,  chamber  contain* 
ing  a  quantity  of  schlich  destined  for  roasting ;  this 
chamber  communicates  with  the  vaulted  corridor 
(gallery)  d,  seen  in  ^g.  i919  ;  g,  orifice  through 
which  the  schlich  is  thrown  into  the  furnace ;  h, 
area  or  hearth  of  the  reverberator)'  furnace,  of  which 
the  roof  is  certainly  much  too  high ;  i,  channels  for 
the  escape  of  the  watery  vapors ;  k,  /,  front  arcade, 
between  which  and  the  furnace,  properly  speaking, 
are  the  two  orifices  of  the  conduits,  which  termi- 
nate at  the  channels  m,  m',  m  is  the  channel  for 
carrying  towards  the  chimney  rf,  the  vapors  which 
escape  by  the  door  e'.  w  is  a  walled-up  door,  which 
is  opened  from  time  to  time,  to  take  out  of  the 
chambers  c,  c,  the  substances  that  may  be  deposited 
in  them. 

At  the  smelting  works  of  Lautenthal,  in  such  a 
roasting  furnace,  from  6  to  9  quintals  (cwts.)  of 
schlich  are  treated  at  a  time,  and  it  is  stirred  frequent- 
ly with  an  iron  rake  upon  the  altar  h.  The  period 
of  this  operation  is  from  6  to  12  hours,  according  as 
the  schlich  may  be  more  or  less  dry,  more  or  less 
rich  in  lead,  or  more  or  less  charged  with  blende. 
When  the  latter  substance  is  abundant,  the  process  requires  12  hours,  with  about  60 
cubic  feet  of  cleft  billots  for  fuel. 

In  such  furnaces  are  roasted  the  cobalt  ores  of  Schneebei^  in  Saxony,  the  tin  ores  of 
Schlackenwald  in  Bohemia,  of  Ehrenfriedersdorf  in  Saxony,  and  elsewhere ;  as  also  the 
arsenical  pyrites  at  Geyer  in  Saxony.      But  there  are  poison  towers  and  extensive  con- 
densing chambers  attached  in  the  latter  case.    See  Arsenic. 
Figs.  922,  923,  924,  represent  the  reverberatory  furnace  generally  employed  in  the 

Hartz,  in  the  district  of  Mansfeldt,  Saxony, 
Hungary,  &c.,  for  the  treatment  of  black  cop- 
per, and  for  refining  rose  copper  upon  the  great 
scale.  An  analogous  furnace  is  used  at  Amlreas- 
^^^^^^  berg  for  the  liquefaction  or  purification  of  the 

■     Mji  )^|^|H|^H1        mattes,  and  for  workable  lead  when  it  is  much 
HI  -^^JBWKBmJi        loaded  with  arsenic. 
"i  I        •  BKi*  Fig.  922  presents  the  elevation  of  the  fur- 

nace  parallel  to  the  line  i  k,  of  the  plan^g.  923  ; 
which  plan  is  taken  at  the  level  of  the  tuyere  », 
of  fig.  924 ;  fig.  924  is  a  vertical  section  in  the  line  l  m,  fig.  923.  k  represents  one  of 
two  basins  of  reception,  brasqued  with  clay  and  charcoal ;  n,  n,  two  tuyeres,  through  which 
enters  the  blast  of  two  pairs  of  bellows,  like  those  shown  at  Cupellation  of  Silver  ;  q, 
door  by  which  the  matter  to  be  melted  is  laid  upon  the  sole  of  the  furnace ;  r,  r,  two 
points  where  the  sole  is  perforated,  when  necessary  to  run  off  the  melted  matter  into 
cither  of  the  basins  h ;  x,  door  through  which  the  slags  or  cinders  floating  upon  the  sur- 


922 


Ml 

III 


11 


158 


METALLURGY. 


li 
If 


\i  ^ 


face  of  the  melted  metal  are  raked  out ;  y,  door  of  the  fire-place.  The  fuel  is  laid  ui)Oii  a 
grate  above  an  ash-pit,  and  below  the  arch  of  a  reverberatory  which  is  contiguous  to  the 
dome  or  cap  of  the  furnace  properly  so  called.  In  the  section,  Jig.  924  the  following 
parts  may  be  noted ;  1,  2,  3,  mason-work  of  the  foundation ;  4,  vapor  channels  or  con- 


923 


924 


duits,  for  the  escape  of  the  humidity;  5,  bed  of  clay;  6,  brasque  composed  of  clay  and 
charcoal,  which  forms  the  concavity  of  the  hearth 

925 


i^ 


-nx 


926 


927 


Figs.  925,  926,  927,  show  the 
furnace  employed  for  liquation  in 
one  of  the  principal  smelting  works 
of  the  Hartz.  Fig.  927  exhibits 
the  working  area  charged  with  the 
liquation  cakes  and  charcoal,  sup« 
ported  by  sheets  of  wrought  iron  j 
being  an  image  of  the  process  in 
action.  Fig.  926  is  the  plan,  in  the 
line  r  g,  of  Jig.  925. 

A  liquation  cake  is  composed 
of— 

Black  copper  holding  at  least  5 
or  6  loths  (2|  or  3  oz.)  of  silver  per 
cwt.,  and  weighing  90  to  96  lbs. 

Lead  obtained  from  litharge,  2 
cwts.     Litharge,  \  cwt. 

From  30  to  32  cakes  are  suc- 
cessively worked  in  one  operation, 
which  lasts  about  5  hours ;  the  fur- 
nace is  brought  into  action,  as  usual, 
with  the  aid  of  slags ;  then  a  little 
litharge  is  added;  when  the  lead 
begins  to  flow,  the  copper  is  intro- 
duced, and  when  the  copper  flows, 
lead  is  added,  so  that  the  mixture 
of  the  metals  may  be  effected  in  the 
best  way  possible. 

From  8  to  16  of  these  cakes  (pains)  are  usually  placed  in  the  liquation  furnace,  Jigs, 
925,  926,  927.  The  operation  lasts  3  or  4  hours,  in  which  time  about  1|  quintals  of  char- 
coal are  consumed.  The  cakes  are  covered  with  burning  charcoal,  supported,  as  I  have 
said,  by  the  iron  plates.  The  workable  lead  obtained  flows  off"  towards  the  basin  in  front 
of  the  furnace ;  whence  it  is  laded  out  into  moulds  set  alongside.  See  Jig.  926  If  the 
lead  thus  obtained  be  not  sufficiently  rich  in  silver  to  be  worth  cupellation,  it  is  employed 
to  form  new  liquation  cakes.  When  it  contains  from  5  to  6  loths  of  silver  per  cwt.,  it  is 
eubmitted  to  cupellation  in  the  said  smelting  works.     See  Silver. 

The  trompe,  or  water  blowing  engine,  Jigs.  928,  929,  930.  Fig.  928  is  the  elevation ; 
Jig.  929  is  a  vertical  section,  made  at  right  angles  to  the  elevation.  The  machine  is  formed 
of  two  cylindrical  pipes,  the  bodies  of  the  trompe  b  b,  set  upright,  called  the  funnels,  which 
terminate  above  in  a  water  cistern  a,  and  below  in  a  close  basin  under  c,  called  the  tub  or 


METALLURGY. 


159 


drum.    The  conical  part  p,  of  the  funnel  has  been  called  etranguiUon,  being  strangled,  as 
it  were,  in  order  that  the  water  discharged  into  the  body  of  the  trompe  shall  not  fill  the 


928 


pipe  in  falling,  but  be  divided  into  many  streamlets.  Below  this  narrow  part,  eight  holes, 
q  q,  are  perforated  obliqueiy  through  the  substance  of  the  trompe,  called  the  vent-holet 
or  nostrils,  for  admitting  the  air,  which  the  water  carries  with  it  in  its  descent.  The  air 
afterwards  parts  from  the  water,  by  dashing  upon  a  cast-iron  slab,  placed  in  the  drum 
upon  the  pedestal  d.  An  aperture  /,  at  the  bottom  of  the  drum,  allows  the  water  to  flow 
away  after  its  fall ;  but,  to  prevent  the  air  from  escaping  along  with  it,  the  water  as  it 
issues  is  received  in  a  chest  I  mno,  divided  into  two  parts  by  a  vertical  slide-plate  be- 
tween m  n.  By  raising  or  lowering  this  plate,  the  water  may  be  maintained  at  any  desi- 
red level  within  the  drum,  so  as  to  give  the  included  air  any  determinate  degree  of  pressure. 
The  superfluous  water  then  flows  oflf  by  the  hole  o. 

The  air-pipe  «,  Jig.  929  is  fitted  to  the  upper  part  of  the  drum ;  it  is  divided,  at  the 
point  /,  into  three  tubes,  of  which  the  principal  one  is  destined  for  the  furnace  of  cupel- 
.ation,  while  the  other  two  g  g,  serve  for  different  melting  furnaces.  Each  of  these 
tubes  ends  in  a  leather  pocket,  and  an  iron  nose-pipe  fc,  adjusted  in  the  tuyere  of 
the  furnace.  At  Pesey,  and  in  the  whole  of  Savoy,  a  floodgate  is  fitted  into  the  upper 
cbtem  a,  to  regulate  the  admission  of  water  into  the  trompe  ;  but  in  Camiola,  the  funnel 
p  is  closed  with  a  wooden  plug,  suspended  to  a  cord,  which  goes  round  a  pulley  mounted 
upon  a  horizontal  axis,  as  shown  in  Jig.  930.  By  the  plug  a  being  raised  more  or  less, 
merely  the  quantity  of  water  required  for  the  operation  is  admitted.  The  plug  is  pier- 
ced lengthwise  with  an  oblique  hole  c  c,  in  which  the  small  tube  c  is  inserted,  with  its  top 
some  way  above  the  water  level,  through  which  air  may  be  admitted  into  the  heart  of  the 
column  descending  into  the  trompe  p  q. 

The  ordinary  height  of  the  trompe  apparatus  is  about  26  or  27  feet  to  the  upper  level 
of  the  water  cistern  j  its  total  length  is  11  metres  (36  feet  6  inches),  and  its  width  2  feet. 


r 


/ 


i ! 


>  J 


I    » 


i    I 


160 


METALLURGY. 


to  give  room  for  the  drams.    It  is  situated  10  metres  (33^  feet)  from  the  melting 
furnace.     This  is  the  case  at  the  smelting  works  of  Jauerberg,  in  Upper  Carniola. 

OF  THB  ASSAT  OF  ORV. 

Assays  ought  to  occupy  an  important  place  in  metallurgic  instructions,  and  there  ia 
reason  to  believe  that  the  knowledge  of  assaying  is  not  sufficiently  diffused,  smce  its 
practice  is  so  often  neglected  in  smelting  houses.  Not  only  ought  the  assays  of  the 
ores  under  treatment  to  be  frequently  repeated,  because  their  nature  is  subject  to  vary ; 
but  the  different  products  of  the  furnaces  should  be  subjected  to  reiterated  assays,  at  the 
several  periods  of  the  operations.  When  sUver  or  gold  ores  are  in  question,  the  doci- 
mastic  operations,  then  indispensable,  exercise  a  salutary  conUol  over  the  metallurgic 
processes,  and  afford  a  clear  indication  of  the  quantities  of  precious  metal  which  they 

ought  to  produce.  ^    .        .  ^         .v  j    r 

By  the  title  Jlssays,  in  a  metaUurgic  point  of  view,  is  meant  the  method  ol  ascertain- 
ing for  any  substance  whatever,  not  only  the  presence  and  the  nature  of  a  metal,  butiU 
proportional  quantity.  Hence  the  operations  which  do  not  lead  to  a  precise  determi- 
nation of  the  metal  in  question,  are  not  to  be  arranged  among  the  assays  now  under 
consideration.  Experiments  made  with  the  blow-pipe,  although  capable  of  yielding  most 
useful  indications,  are  like  the  touchstone  in  regard  to  gold,  and  do  not  constitute  genuine 

assays.  .  ,     .^, 

Three  kinds  of  assays  may  be  practised  in  different  circumstances,  and  with  more  or 
less  advantage  upon  different  ores.     1.  The  mechanical  assay ;  2.  the  assay  by  the  dry 

way ;  3.  the  assay  by  the  humid  way.  ...  »•         r   ♦!. 

1.  0/  Tnechanical  assays.— These  kinds  of  assays  consist  m  the  separation  ol  tne 
substances  mechanically  mixed  in  the  ores,  and  are  performed  by  a  hand-washing,  m  a 
smaU  trough  of  an  oblong  shape,  caUed  a  sebiUa.  After  pulverizing  with  more  or  less 
pains  the  matters  to  be  assayed  by  this  process,  a  determinate  weight  of  them  is  put  into 
this  wooden  l>owl  with  a  little  water ;  and  by  means  of  certain  movements  and  some 
precautions,  to  be  learned  only  by  practice,  the  Hghtest  substances  may  be  pretty  exactly 
separated,  namely,  the  earthy  gangues  from  the  denser  matter  or  metallic  particles,  with- 
out losing  any  sensible  portion  of  them.  Thus  a  schlich  of  greater  or  less  purity  wiU  be 
obtained,  which  may  afford  the  means  of  judging  by  its  quahty  of  the  richness  of  the  as- 
sayed ores,  and  which  may  thereafter  be  subjected  to  assays  of  another  kind,  whereby  th« 
whole  metal  may  be  insulated.  «         /.        i.     ^  j 

Washing,  as  an  assay,  is  practised  on  auriferous  sands ;  on  all  ores  from  the  stampsy  and 
even  on  schlichs  aheady  washed  upon  the  great  scale,  to  appreciate  more  nicely  the  degree 
of  purity  they  have  acquired.  The  ores  of  tin  in  which  the  oxyde  is  often  disseminated 
in  much  earthy  gangue,  are  well  adapted  to  this  species  of  assay,  because  the  tin  oxyde 
is  very  dense.  The  mechanical  assay  may  also  be  employed  in  reference  to  the  ores 
whose  metallic  portion  presents  a  uniform  composition,  provided  it  also  possesses  con 
siderable  specific  gravity.  Thus  the  ores  of  sulphuret  of  lead  (galena)  being  susceptible 
of  becoming  ahnost  pure  sulphurets  (within  I  or 'Z  per  cent.)  by  mere  washing  skilfully 
conducted,  the  richness  of  that  ore  in  pure  galena,  and  consequently  in  lead,  may  be  at 
once  concluded ;  since  120  of  galena  contain  104  of  lead,  and  16  of  sulphur.  The  sul- 
phuret of  antimony  mingled  with  its  gangue  may  be  subjected  to  the  same  mode  of  assay, 
and  the  result  will  be  still  more  direct,  since  the  crude  antimony  is  brought  mto  the  mar- 
ket after  being  freed  from  its  gangue  by  a  simj'e  fusion.        ,  .      ..  ^  ,, 

The  assay  by  washing  is  also  had  recourse  to  for  ascertaining  if  the  scoria  or  other 
products  of  the  furnaces  contain  some  metallic  grains  which  might  be  extracted  from 
them  by  stamping  and  washing  on  the  great  scale ;  a  process  employed  considerably  with 
the  jcorue  of  tin  and  copper  works.  ,      v    .    .     v 

Of  assays  by  the  dry  way.— The  assay  by  the  dry  way  has  for  its  object,  to  show 
the  nature  and  proportion  of  the  metals  contained  in  a  mineral  substance.  To  make  a 
good  assay,  however,  it  is  indispensably  necessary  to  know  what  is  the  metal  associated 
with  it,  and  even  within  certain  Umits,  the  quantity  of  the  foreign  bodies.  Only  one 
metal  is  commonly  looked  after ;  unless  in  the  case  of  certain  argentiferous  ores.  The 
mineralogical  examination  of  the  substances  under  treatment,  is  most  commonly  sufficient 
to  afford  data  in  these  respects;  but  the  assays  may  always  be  varied  with  different  views, 
before  stopping  at  a  definite  result ;  and  in  every  instance,  only  such  assays  can  be  con- 
fided  in,  as  have  been  verified  by  a  double  operation. 

This  mode  of  assaying  requires  only  a  little  experience,  with  a  simple  apparatus ;  and 
is  of  such  a  nature  as  to  be  practised  currently  in  the  smelting  works.  The  air  furnace 
and  crucibles  employed  are  described  in  aU  good  elementary  chemical  books.  These 
assays  are  usually  performed  with  the  addition  of  a  flux  to  the  ore,  or  some  agent  for 
separating  the  earthy  from  the  metallic  substances ;  and  they  possess  a  peculiar  advan- 
tage relative  to  the  smelting  operations,  because  they  offer  many  analogies  between 


METALLURGY. 


161 


reflults  on  the  great  scale  and  experiments  on  the  smalL  This  may  even  enable  vm 
often  to  deduce,  from  the  manner  m  which  the  assay  has  succeeded  with  a  certain  flui, 
and  at  a  certain  degree  of  heat,  valuable  indications  as  to  the  treatment  of  the  ore  ia 
the  great  way.     See  FuENAfc>- 

In  the  smelting  houses  which  purchase  the  ore,  as  in  Germany,  it  is  necessary  to 
bestow  much  attention  upon  the  assays,  because  they  serve  to  regulate  the  quality  and 
the  price  of  the  schlichs  to  be  delivered.  These  assays  are  not  bv  any  means  fr«e 
from  difficulties,  especially  when  ores  containing  several  useful  metals  are  treated,  and 
which  are  to  be  dosed  or  proportioned ;  ores,  for  example,  including  a  notable  quantity 
of  lead,  copper,  and  silver,  mixed  together. 

In  the  central  works  of  the  Hartz,  as  well  as  in  those  of  Saxony,  the  schlichs  as  de- 
livered are  subjected  to  docimastic  assays,  which  are  verified  three  times,  and  by  three 
difierent  persons,  one  of  whom  is  engaged  for  the  interests  of  the  mining  partners, 
another  for  that  of  the  smelting  house,  and  a  third  as  arbiter  in  case  of  a  difl'erence.  If 
the  first  two  results  of  assaying  differ  by  |  loih  (or  ^  ounce)  of  silver  per  cwt.  cf  schlich, 
the  operations  must  be  resumed ;  but  this  rarely  happens.  When  out  of  the  three  assayfu 
the  one  differs  from  the  two  others  by  no  more  than  \  loth  of  silver  per  c>Rt.,  but  bj 
more  in  one,  and  by  less  in  another,  the  mean  result  is  adopted.  As  to  the  contents  of  the 
schlich  in  lead,  the  mean  results  of  the  assays  must  be  taken.  The  differences  allowed 
are  three  pounds  for  the  schlich^  when  it  contains  from  12  to  30  per  cent,  of  lead,  increoB- 
ing  to  six  pounds  for  schlich,  when  it  contains  less  than  55  per  cent,  of  that  metal. 

Assaying  forms,  in  great  establishments,  an  important  object  in  reference  to  lime  and 
expense.  Thus,  in  the  single  work  of  Franckenscharn,  in  the  Hartz,  no  less  than  300 
assays  have  to  be  made  in  a  threefold  way,  every  Monday,  without  taking  into  accounl 
the  several  assays  of  the  smelting  products  which  take  place  every  Thursday.  Formerly 
Aiixes  more  or  less  compound  were  employed  for  these  purposes,  and  every  assay  com 
about  fifteen  pence.  At  present  all  these  assays  are  made  more  simply,  by  much  cheaper 
methods,  and  cost  a  penny  farihing  each  upon  an  average. 

Of  the  assays  by  the  humid  way. — The  assays  by  the  humid  way,  not  reducible  to  very 
simple  processes,  are  true  chemical  analyses,  which  may  in  fact  be  applied  with  much 
advantage,  either  to  ores,  or  to  the  products  of  the  furnace ;  but  which  cannot  be  expected 
to  be  practised  in  smclting-houses,  on  account  of  the  complication  of  apparatus  and 
reagents  they  require.  Moreover,  an  expert  chemist  is  necessary  to  obtain  results  that 
can  be  depended  on.  The  directors  of  smelting-houses,  however,  should  never  neglect  any 
opportunities  that  may  occur  of  submitting  the  materials  operated  upon,  as  well  as  their 
products,  to  a  more  thorough  examination  than  the  dry  way  alone  can  eliect.  One  of  the 
great  advantages  of  similar  researches  is  to  discover  and  appreciate  the  minute  quantities 
of  injurious  substances  which  impair  the  malleability  of  the  metals,  which  give  them  seve- 
ral bad  qualities,  about  whose  nature  and  cause  more  or  less  error  and  uncertainty  prevaft. 
Chemical  analysis,  rightly  applied  to  metallurgy,  cannot  fail  to  introduce  remarkable 
improvements  into  the  processes.    See  the  different  metals,  in  their  alphabetical  places. 

For  assays  in  the  dry  way,  both  of  stony  and  metallic  minerals,  the  process  of  Dr. 
Abich  deserves  recommendation.  It  consists  in  mixing  the  pulverized  mineral  with  4  oi 
6  times  its  weight  of  carbonate  of  baryta  in  powder,  fusing  the  mixture  at  a  white  heal, 
and  then  dissolving  it,  after  it  cools,  in  dilute  muriatic  acid.  The  most  refractory  mine- 
rals, even  corundum,  cyanate,  staurolite,  zircon,  and  feldspar,  yield  readily  to  this  treat- 
ment. This  process  may  be  employed  with  advantage  upon  poor  refractory  ores.  The 
platinum  crucible,  into  which  the  mixed  materials  are  put  for  fusion,  should  be  placed  ir 

a  Hessian  crucible,  and  surrounded  with  good  coke. 

The  manganese  raised  in  England  exceeds  2000  tons. 

M.  Heron  de  Villefosse  inserted  in  the  last  number  of  the  AnnaUs  des  MiM»  for  J627;; 
the  following  statistical  view  of  the  metallic  products  of  France : — 


Lead  in  pigs  (saumons)  -  -  . 

Litharge  -  -  -  .  - 

Sulphuret  of  lead,  ground  galena  (alquifoux)  - 
Black  copper  ..... 
Antimony  .  -  .  -  . 

Manganese  ..... 
Crude  cast-iron  .... 

Bar  iron  ..... 

Steel  --..•. 
Silver  in  ingots  .... 

Vol.  n.  11 


Tons. 

103 

513 

112 

164 

91 

765 

25,606 

127,643 

3,500 


/ 


I 


I 


Jl 


i 


I  ,  :l! 


102 


METER,  GAS. 


M   i'^t. 


The  total  value  of  which  is  estimated  at  80  millions  of  francs,  or  about  3  400,000 
pounds  sterling. 

AICTALS;  {Metaux,  Fr. ;  Metalle,  Germ.)  are  by  far  the  most  numerous  class  of 
nndecompouiided  bodies  m  chemical  arrangements.  They  amount  to  43  •  of  which  t 
form  with  oxygen,  bodies  possessed  of  alkaline  properties:  these  are,  l!  pota-ssium; 
2.  sodium ;  3.  lithium ;  4.  barium ;  6.  strontium  ;  6.  calcium ;  7.  magnesium  ;  for  evea 
magnesia,  the  last  and  feeblest  base,  tinges  turmeric  brown,  and  red  cabbage  green. 
iTie  next  five  metals  form,  with  oxygen,  the  earths  proper ;  they  are,  8.  yttrium ;  9. 
glucmum;  10.  aluminum;  11.  zirconium;  12.  thorium.  The  remAinin<r  31  maybe 
enumerated  in  alphabetical  order,  as  they  hardly  admit  of  being  grouped  into  subdi- 
visions with  any  advantage.  They  are  as  follows:  13.  antimony;  14.  arsenic-  16. 
bismuth;  16.  cadmium;  17.  cerium;  18.  chromium;  19.  cobalt;  20.  copper;  21.  gold; 
22.  iridium ;  23.  iron ;  24.  lead ;  25.  manganese ;  26.  mercury ;  27.  molybdenum  •  28. 
nickel;  29.  osmium;  30.  palladium;  31.  platinum;  32.  rhodium;  33.  silver;  34.  tan- 
talum;  35.  tellurium;  36.  tin;  37.  titanium;  38.  tungstenium;  39.  vanadium-  40. 
uranium;  41.  zinc;  42.  niobium;  43.  pelopium. 

1.  They  are  all,  moie  or  less,  remarkable  for  a  peculiar  lustre,  called  the  metallic 
This  property  of  strongly  reflecting  light  is  connected  with  a  certain  state  of  a-^grega- 
tion  of  their  particles,  but  is  possessed,  superficially  at  least,  by  mica,  animal  charcoaL 
selenium,  polished  indigo;— bodies  not  at  all  metallic. 

*^}'  T?*^  °^«*al8  are  excellent  conductors  of  caloric,  and  most  of  them  also  of  electricitr, 
though  probably  not  all.  According  to  Despretz,  they  possess  the  power  of  conducting 
heat  according  to  the  following  numbers :— gold,  1000;  platinum,  981;  silver.  973; 
copper,  898;  iron,  374;  zinc,  363;  tin,  304;  lead,  179-6. 

Becquerel  gives  the  following  table  of  metals,  as  to  electrical  conduction-— 

Copper  100;  gold,  93-6;  silver,  73-6;  zinc,  285;  platina,  16-4;  iron,  15-8;  tin, 
15-6;  lead,  8-3;  mercury,  3-5;  potassium,  133. 

The  metals  which  hardly,  if  at  all,  conduct  electricity,  are,  zirconium;  aluminum: 
tantalum,  m  powder;  and  tellurium. 

3.  Metals  are  probably  opaque ;  yet  gold  leaf,  as  observed  by  Newton,  seems  to 
transmit  the  green  rays,  for  objects  placed  behind  it  in  the  sunbeam  appear  green. 
1  his  phenomena  has,  however,  been  ascribed  to  the  rays  of  light  passim;  through  an 
lulinite  number  of  minute  fissures  in  the  thinly  hammered  gold. 

4.  All  metals  are  capable  of  combining  with  oxygen,  but  with  affinities  and  in  quan- 
tities extremely  different.  Potassium  and  sodium  have  the  strongest  affinity  for  it 
arsenic  and  chromium  the  feeblest  Many  metals  become  acids  by  a  sufficient  dose  of 
oxygen,  while,  with  a  smaller  dose,  they  constitute  salifiable  bases, 

5.  Metals  combine  with  each  other,  forming  a  class  of  bodies  called  alloys,  except 
when  one  of  them  is  mercury,  in  which  case  the  compound  is  styled  an  amalgam. 

6.  The^r  combine  with  hydrogen,  into  hydrureti;  with  carbon,  into  carburets;  with 
sulphur,  into  sulphtcrets ;  with  phosphorus,  into  phosphurets;  with  selenium,  into 
selmiurets;  with  boron,  into  borureta  {borides?);  with  chlorine,  into  chlondes ;  with 
iodine,  into  todideg;  with  cyanogen,  into  cyanides;  with  silicon,  into  silicides  ;  and  with 
fluorine,  into /uorides. 

7.  Metallic  salts  are  definite  compounds,  mostly  crystalline,  of  the  metallic  oxides 
with  the  acids.     See  Haloid. 

METEORITES,  {Aerolithes,  Fr.),  are  stones  of  a  peculiar  aspect  and  composition, 
which  have  fallen  from  the  air. 

METER  GAS.  Since  the  article  Gas  was  printed  I  have  had  occasion  to  examine 
very  carefully  the  construction,  performance,  and  comparative  merits  of  the  four  gas- 
meters  most  generally  used  in  Great  Britain,  and  have  been  led  to  conclude  that  the 
surmises  concerning  the  correctness  of  the  indications  of  several  of  them,  but  too  well 
founded.  The  instruments  on  which  my  observations  were  made  were  all  new  and 
just  out  of  the  hands  of  their  respective  patentees.  ' 

•  h  ^^V^^^^^J  ^^^'  ^^"^  ^^'  ^®  ^^*^^^  accurate  while  the  water-line  is  rightlv  ad- 
justed; but  as  I  find  that  it  will  admit  an  extra  pint  of  water,  it  may  be  rendered  un- 
just towards  the  consumers  of  gas ;  and  then  if  it  receives  a  little  more  water  bv  con- 
of  the  l?\ll  ''*^'''''  **""  ^^  accident,  its  siphon  gets  filled,  which  causes  the  extinction 

2.  The  meter  of  Mr.  Bottom  has  also  several  defects,  and  occasions  nuisance  bv  lettinff 
its  overflow  water  trickle  upon  the  floor.  ^         ^ 

^1  l'^^  ™«^«^  «^  ^^^-  Crossley  may  be  made  to  err  in  its  measurements  fully  20  per 
cent  by  dexterous  repletion  with  water,  and  that  in  favor  of  the  gas  companies. 

ITiese  three  meters  are  furnished  with  the  vertical  float  valve,  so  apt  to  rust  and  stick : 
they  also  allow  gas  to  escape  at  the  discharge  plug,  to  the  imminent  risk  of  occasion! 
ing  fire  with  ignorant  or  careless  servants ;  and  finally,  they  have  the  complex  dial- 
plate  indexes,  so  liable  to  misapprehension.  •'        j  f 


MILK. 


163 


4.  The  meter  of  Mr.  Edge.  This  instrument  is  quite  exempt  from  all  the  above 
defects,  and  is  equally  delicate  and  just  in  its  indications,  being  mounted  with  a  lever 
valve  of  great  mobility,  and  a  new  index,  which  any  one  who  knows  numbers  cannot 
miscount  I  have  subjected  this  meter  to  every  kind  of  test,  and  find  that  it  cannot  be 
made  to  give  false  indications,  either  by  awkwardness  or  intention.  Its  inventor  is 
therefore  well  entitled  to  the  warm  patronage  both  of  the  public  and  all  gas  companies 
who  love  fair  dealing. 

METIIYLE'NE,  a  peculiar  liquid  compound  of  carbon  and  hydrogen,  extracted  from 
pyroxylie  spirit,  which  is  reckoned  to  be  a  bi-hydrate  of  methylene. 

METlllOAL  MEASURES.  The  phrase  "  metrical  measures  "  appears  to  an  or- 
dinary reader  to  savor  of  tautology.  It  is  really  not  so,  however,  in  the  present 
instance ;  for  the  expression  simply  means  a  set  of  measures  founded  on  the  standard 
called  the  "  metre,"  which  was  adopted  by  the  government  of  France  at  the  epoch  of 
the  first  revolution.  This  standard  is  the  ten-millionth  part  of  the  (]^uadrant  of  the  ter^ 
restrial  meridian,  and  from  the  measurements  and  calculations  which  were  made  at 
that  period  on  an  arc  of  the  meridian  which  extended  from  Barcelona  to  Dunkirk,  it 
was  reckoned  to  be  39-371  inches  of  the  English  standard  yard,  which  contained  36 
inches.  Thus  the  French  metre,  which  is  longer  than  the  English  yard  by  3^  inches, 
or  more  accurately  by  3 "37  inches,  is  the  standard  of  all  the  measures  and  weights 
of  France.  Its  decimal  multiples  are  successively  denoted  by  the  prefixes  deca,  heca^ 
chiles,  &e.,  which  signify  10,  100,  1000,  Ac,  times  respectively;  and  its  decimal  sub- 
multiples  or  fractions  successively  by  the  prefixes  deci,  centi,  milli,  Ac,  which  signify 
fffi  tUi  tfWi  <fec.,  parts  respectively.  The  metre  itself  was  made  the  unit  of  lineal 
measure  and  itinerary  distances. 

The  deca  metre  squared,  which  was  called  the  arc,  and  consequently  contains  100 
square  metres,  was  made  the  unit  of  superficial  or  land  measure ;  its  centesimal  mul- 
tiple hecteare  contains  10,000  square  metres,  and  its  centesimal  submultiple  centeare  1 
equai-e  metre. 

The  decimetre  cubed,  which  was  called  the  litre,  and  therefore  contained  a  thousandth 
part  of  the  metre  cubed,  was  made  the  unit  of  capacity  for  liquids  ;  its  decimal  multiple 
decalitre  contains  10  cubic  decimetres,  and  its  decimal  submultiple  decilitre  one-tenth 
part  of  the  cubic  decimetre.  The  litre  and  its  successive  multiples  decalitre,  hfctolitre, 
Ac,  were  also  made  the  measures  for  dry  goods,  such  as  corn,  Ac.  The  cubic  metre 
itself  was  made  the  unit  of  solid  measures,  and  called  the  stere  ;  its  decimal  subiuultiple 
the  decistere  containing  a  tenth  part  of  the  cubic  metre  The  weight  of  a  cubic  eenti- 
metre  of  distilled  water  at  the  maximum  density  was  called  the  gramme,  and  made  the 
unit  of  all  measures  of  weight  This  unit  was  found  by  careful  experiments  to  be 
equivalent  to  15-434  grains  of  English  troy  weight;  hence  the  kilogramme,  the  usual 
unit  for  commercial  purposes  in  France,  weighs  a  trifle  more  than  22  pounds  of  Eng- 
lish avoirdupois  weight  From  the  decimal  relations  which  subsist  among  these  different 
weight*}  and  measures,  it  plainly  appears  that  the  kilogramme  is  equal  to  the  weight  of 
a  cubic  decimetre  of  water,  or  of  a  litre  of  the  same  liquid  at  the  maximum  densit}'. 
The  capacity  of  the  litre  is  therefore  a  trifle  more  than  61  English  cubic  inches,  or  about 
two-ninths  of  an  English  gallon  diminished  by  a  hundredth  part  of  the  two-ninths. 

MICA  is  a  finely  foliated  mineral,  of  a  pearly  metallic  lustre.  It  is  harder  than 
gypsum,  but  not  so  hard  as  calc-spar;  flexible  and  elastic;  spec  grav.  2*65.  It  is  an 
ingredient  of  granite  and  gneiss.  The  large  sheets  of  mica  exposed  for  sale  in  London, 
are  mostly  brought  from  Siberia.  They  are  used,  instead  of  glass,  to  enclose  the  fire, 
without  concealing  the  flame,  in  certain  stoves. 

The  mica  of  Fahluii,  analyzed  by  Rose,  afforded  silica,  46*22 ;  alumina,  34*52 ;  per- 
oxide? of  iron,  6*04;  potash,  822;  magnesia,  with  oxide  of  manganese,  2'11;  fluoric 
acid,  1-09'  water  0*98. 

MICROCOSMIO  SALT;  a  term  given  to  a  salt  extracted  from  human  urine, 
because  man  was  regarded  by  the  alchemists  as  a  miniature  of  the  world,  or  the  mi- 
crocosm. It  is  a  phosphate  of  soda  and  ammonia ;  and  is  now  prepared  by  mixing 
equivalent  proportions  of  phosphate  of  soda  and  phosphate  of  ammonia,  each  in  solu- 
tion, evaporating  and  crystallizing  the  mixture.  A  small  excess  of  ammonia  aids  the 
crystallization. 

MILK ;  {Lait,  Fr. ;  Milche,  Germ.)  owes  its  whiteness  and  opacity  to  an  emulsion 
composed  of  the  caseous  matter  and  butter,  with  sugar  of  milk,  extractive  matters, 
salts,  and  free  lactic  acid ;  the  latter  of  which  causes  fresh  milk  to  redden  litmus  paper. 
Milk,  in  general,  contains  from  10  to  12  per  cent  of  solid  matter,  on  being  evaporated 
to  drvness  by  a  steam  heat  The  mean  specific  gravity  of  cows'  milk  is  l-r.30,  but  it 
is  less  if  the  milk  be  rich  in  cream.  The  specific  gravity  of  the  skimmed  milk  is  l-O^iS; 
and  of  the  cream  is  1*0244.     100  parts  of  creamed  milk  contain: — 


*  ! 


/ 


I 


!' 


164 


MILL  ARCHITECTURE. 


Caseous  matter,  containing  some  butter,  -        .        .        .        .     2*6P0 

Sugar  of  milk,  - 8-500 

Alcoholic  extract,  lactic  acid,  and  lactates,  -  ■  .  .  •  0*600 
Salts ;  muriate  and  phosphate  of  potash,  and  phosphate  of  lime,  -  0*420 
Water, 92*875 

Cream  consists  of-r 

Butter  separated  by  churning, 4*5 

Caseous  matter  precipitated  by  the  coagulation  of  the  milk  of  the  butter,  3*5 
Butter-milk, 92*0 

When  milk  contained  in  wire-corked  bottles  is  heated  to  the  boiling  point  in  ft 
water-bath,  the  oxygen  of  the  included  small  portion  of  air  under  the  cork  seems  to  be 
carbonated,  and  the  milk  will  afterwards  keep  fresh,  it  is  said,  for  a  year  or  two;  as 
green  gooseberries  and  peas  do  by  the  same  treatment 

Milk  has  been  adulterated  with  a  solution  of  potato  starch,  from  which  it  derives  a 
creamy  consistence.  This  fraud  may  be  detected  by  pouring  a  few  drops  of  iodine 
water  into  it,  which  immecliately  causes  it  to  assume  a  olue  or  purple  tint.  Emulsion 
of  sweet  almonds,  with  which  the  milk  at  Paris  has  been  adulterated,  may  be  readily 
detected  by  the  taste. 

MILL  ARCHITECTURE,  is  a  science  of  recent  origin,  which  even  at  this  day  is 
little  understood  beyond  the  factory  precincts.  It  had  been  ably  begun  by  Mr.  Watt, 
but  till  it  fell  into  the  hands  of  Messrs.  Fairbairn  and  Lillie,  eminent  engineers  of 
Manchester,  it  was  too  subject  to  the  whims  of  the  several  individuals,  often  utterly 
ignorant  of  statics  or  dynamics,  or  the  laws  of  equilibrium  and  impulse,  who  had 
capital  to  lay  out  in  building  a  mill  Each  had  his  own  set  of  caprices  and  prejudices, 
which  he  sought  to  embody  in  his  edifice,  little  aware  how  much  the  different  orders 
of  machines  depended  for  the  productiveness  and  precision  of  their  performance  on 
the  right  magnitudes,  proportions,  and  adjustments  of  the  main  shafting  and  wheel 
gearing.  These  are  in  fact  the  grand  nerves  and  arteries  which  transmit  vitality  and 
volition,  so  to  speak,  with  due  steadiness,  delicacy,  and  speed,  to  the  automatic  organs. 
Hence,  if  they  be  ill-made  or  ill-distributed,  nothing  can  go  well. 

Mr.  Fairbairn  has  for  many  years  entered  largely  into  the  line  of  a  factory  architect, 
for  which  his  three-fold  great  workshops  are  admirably  adapted.  The  capitalist  has 
merely  to  state  the  extent  of  his  resources,  the  nature  of  his  manufacture,  its  intended 
site  and  facilities  of  position  in  reference  to  water  or  coal,  when  he  will  be  furnished 
with  designs,  estimates,  and  offers  on  the  most  economical  terms  consistent  with  excel- 
lence, according  to  a  plan  combining  elegance  of  external  aspect  with  solidity,  con- 
venience, and  refinement  in  the  internal  structure.  As  engineer,  he  becomes  respon- 
sible for  the  masonry,  carpentry,  and  other  woik  of  the  building,  for  the  erection  of  a 
sufficient  power,  whether  of  a  steam-engine  or  water-wheel,  to  drive  every  machine  it 
is  to  contain,  and  for  the  mounting  of  all  the  shafts  and  great  wheels  by  which  the 
power  of  the  first  mover  is  distributed. 

The  recent  innovations  in  proportioning  the  sizes,  regulating  the  connections,  and 
adjusting  the  movements  of  the  system  of  shaft-gearing,  form  a  fine  feature  in  the 
philosophy  of  manufactures.  Thus  not  only  an  improvement  has  been  made  in  the 
regularity  of  impulsion,  but  a  considerable  increase  of  power  from  the  same  prime- 
mover  has  been  obtained;  amounting  in  some  cases,  of  old  mills  remounted  by  Messrs. 
Fairbairn  and  LiUie,  to  fully  20  per  cent  The  durability  of  shafts  so  exquisitely  turned 
and  polished  is  another  great  advantage.  Tlie  spinning  factory  of  Messrs.  Ashworth, 
at  Egerton,  which  has  been  at  work  for  several  years,  exhibits  an  excellent  pattern  of 
the  engineering  just  described:  for  it  has  some  subordinate  shafts,  hardly  thicker  than 
the  human  wrist,  which  convey  the  power  of  ten  horses,  and  revolve  with  great  speed, 
without  the  slightest  noise  or  vibration.  The  prime-mover  of  the  whole  is  a  gigantio 
water-wheel  of  60  feet  diameter,  and  100  horses'  power.  I  have  frequently  been  at  a 
loss  in  walking  through  several  of  the  mill-wright  factories,  to  know  whether  the 
polished  shafts  that  drive  the  automatic  lathes  and  planing  machines  were  at  rest  or 
in  motion,  so  truly  and  silently  did  they  revolve. 

The  method  of  increased  velocities  iu  the  driving  arms  or  shafts  of  factories  is  un- 
doubtedly one  of  the  most  remarkable  improvements  in  practical  dynamics.  It  dimi- 
nishes greatly  the  inertia  of  the  mass  to  be  moved,  by  giving  to  much  lighter  shafts  and 
wheels  the  same  momentum;  and  it  permits  the  pulleys  or  drums,  which  immediately 
impel  the  machines  by  straps,  to  be  reduced  to  a  size  much  nearer  to  that  of  the  steara 
pulleys  fixed  on  the  main  axes  of  these  machines.  About  thirty  years  ago  the  velocities 
of  the  main  shafts  proceeding  from  the  moving  power,  whether  of  steam  or  water, 
amounted  to  no  more  than  from  30  to  40  revolutions  per  minute ;  and  of  the  smaller 
and  remoter  shafts,  to  only  40  or  50.    At  the  same  period  the  drums  were  heavy  tub% 


MINING. 


165 


and  from  80  to  upwards  of  60  Inches  in  diameter.  This  improved  system  is  under 
deep  obligations  for  its  actual  state  of  perfection  to  the  above-named  engineers,  though 
it  had  commenced,  as  we  have  stated,  before  their  time.  In  the  mills  mounted  by  these 
gentlemen,  it  is  interesting  to  see  slender  shafts,  like  small  sinewy  arms,  rapidly  trans- 
mitting vast  power  through  all  the  ramifications  of  a  great  factory. 

The  following  details  will  place  this  matter  in  the  clearest  light : — ^A  mill  propelled  by 
a  steam-engine  of  50  horses'  power,  was  formerly  geered  with  shafts,  having  an  average 
transverse  section  of  36  square  inches,  or  varying  in  size  from  4  to  8  inches  square.  An 
engine  of  like  power  at  the  present  day  will,  in  consequence  of  the  increased  velocities 
above  described,  work  with  cylindrical  shafts  not  exceeding  6i,  and  often  only  3  inches 
in  diameter;  possessing,  therefore,  an  average  area  of  only  15  square  inches,  instead  of 
36.  The  horizontal  shafts  that  run  under  the  ceilings  of  the  diflferent  working-rooms 
are  2  inches,  and  seldom  exceed  2\  in  diameter.  Hence  the  mass  of  geering  has  been 
reduced  fully  one-halt  But  the  shafts  now  make  from  120  to  150  revolutions  in  a 
minute,  and  occasionally,  as  where  throstles  are  turned,  so  many  as  200  in  the  same 
time.  Thus  we  see  the  requisite  momentum  is  gained  with  a  light  shaft,  while  the 
friction  is  proportionally  diminished,  and  the  driving-drum  revolves  with  a  velocity  in 
accordance  with  the  accelerated  pace  of  the  modern  machines.  The  several  speeds 
are  given  in  discussing  their  respective  subjects. 

The  philosophy  of  manufactures  investigates,  in  the  next  place,  the  most  economical 
and  energetic  modes  of  applying  the  motive  force  to  the  various  working  organs;  the 
carding  engines,  the  drawing  heads,  the  roving  frames,  the  throstles,  the  mules,  the 
power-looms,  the  dressing-machines,  <fec. 

The  British  capitalist  is  vigorously  seconded  by  the  British  engineer,  and  need  not, 
like  the  continental  adventurer,  leave  his  funds  long  dormant,  after  an  opportunity  of 
placing  them  profitably  in  factory  enterprise  occurs.  Fairbairn's  millwright  establish- 
ment in  Manchester  turns  out  from  300  to  400  yards  of  shaft-geering  every  week, 
finely  finished  at  a  very  moderate  price,  because  almost  every  tool  is  now  more  or  less 
automatic,  and  performs  its  work  more  cheaply  and  with  greater  precision  than  the 
hand  could  possibly  do.  Where  many  counterparts  or  similar  pieces  enter  into  spinning 
apparatus,  they  are  all  made  so  perfectly  identical  in  form  and  size,  by  the  self-acting 
tools,  such  as  the  planing  and  key-grove  cutting  machines,  that  any  one  of  them  will 
at  once  fit  into  the  position  of  any  of  its  fellows  in  the  general  frame. 

MILL-STONE,  or  Buhr-Stone.  This  interesting  form  of  silica,  which  occurs  in  great 
masses,  has  a  texture  essentially  cellular,  the  cells  being  irregular  in  number,  shape,  and 
size,  and  are  often  crossed  by  thin  plates,  or  coarse  fibres  of  silex.  The  Buhr-stone  has 
a  slraisht  fracture,  but  it  is  not  so  brittle  as  flint,  though  its  hardness  is  nearly  the  same. 
It  is  feebly  translucent ;  its  colors  are  pale  and  dead,  of  a  whitish,  grayish,  or  yellowish 
cast,  sometimes  with  a  tinge  of  blue. 

The  Buhr-stones  usually  occur  in  beds,  which  are  sometimes  continuous,  and  at  others 
interrupted.  These  beds  are  placed  amid  deposites  of  sand,  or  argillaceous  and  ferru- 
ginous marls,  which  penetrate  between  them,  filling  their  fissures  and  honeycomb  cavities. 
Buhr-stones  constitute  a  very  rare  geological  formation,  being  found  in  abundance  only  in 
the  mineral  basin  of  Paris,  and  a  few  adjoining  districts.  Its  place  of  superposition  is 
well  ascertained :  it  forms  a  part  of  the  lacustrine,  or  fresh-water  formation,  which,  in 
the  locality  alluded  to,  lies  above  the  fossil-bone  gypsum,  and  the  stratum  of  sand  and 
marine  sandstone  which  covers  it.  Buhr-stone  constitutes,  therefore,  the  uppermost  solid 
stratum  of  the  crust  of  the  globe ;  for  above  it  there  is  nothing  but  alluvial  soil,  or  diluvial 
gravel,  sand,  and  loam. 

Buhr-stones  sometimes  contain  no  organic  forms,  at  others  they  seem  as  if  stuflfed  full 
of  fresh-water  shells,  or  land  shells  and  vegetables  of  inland  growth.  There  is  no  excep- 
tion known  to  this  arrangement ;  but  the  shells  have  assumed  a  silicious  nature,  and  their 
cavities  are  often  bedecked  with  crystals  of  quartz.  The  best  Buhr-stones  for  grinding 
corn,  have  about  an  equal  proportion  of  solid  matter,  and  of  vacant  space.  The  finest 
quarry  of  them  is  upon  the  high  ground,  near  La  Fertesous-Jouarre.  The  stones  are 
quarried  in  the  open  air,  and  are  cut  out  in  cylinders,  from  one  to  two  yards  in  diameter, 
by  a  series  of  iron  and  wooden  wedges,  gradually  but  equally  inserted.  The  pieces  of 
buhr-stones  are  afterwards  cut  in  parallelepipeds,  called  panes,  which  are  bound  with  iron 
hoops  into  large  millstones.  These  pieces  are  exported  chiefly  to  England  and  America. 
Good  millstones  of  a  bluish  white  color,  with  a  regular  proportion  of  cells,  when  six  feet 
and  a  half  in  diameter,  fetch  1200  francs  a-piece,  or  48/.  sterling.  A  coarse  conglom- 
erate sandstone  or  breccia  is,  in  some  cases,  used  as  a  substitute  for  buhr-stones ;  but 
it  is  a  poor  one. 

MINERAL  WATERS.    See  Soda  Water,  and  Waters,  Mineral. 

MINES,  {Bergwerke,  Germ.)  Amidst  the  variety  of  bodies  apparently  infinite,  which 
compose  the  crust  of  the  globe,  geologists  have  demonstrated  the  prevalence  of  a  few 

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166 


MINEa 


general  systems  of  rocks,  to  which  they  have  given  the  name  of  formations  or  deposita. 
A  large  proportion  of  these  mineral  systems  consists  of  parallel  planes,  whose  length  and 
breadth  greatly  exceed  their  thickness ;  on  which  account  they  are  called  stratified  rocks  ; 
others  occur  in  very  thick  blocks,  without  any  parallel  stratification,  or  horizontal  seams 
of  considerable  extent. 

The  stratiform  deposites  are  subdivided  into  two  great  classes ;  the  primary  and  the 
secondary.  The  former  seem  to  have  been  called  into  existence  before  the  creation  of 
organic  matter,  because  they  contain  no  exuvice  of  vegetable  or  animal  beings ;  while 
the  latter  are  more  or  less  interspersed,  and  sometimes  replete  with  organic  remains. 
The  primary  strata  are  characterized,  moreover,  by  the  nearly  vertical  or  highly  inclined 
position  of  their  planes ;  the  secondary  lie  for  the  most  part  in  a  nearly  horizontal 
position. 

Where  the  primitive  mountains  graduate  down  into  the  plains,  rocks  of  an  intermediate 
character  appear,  which,  though  possessing  a  nearly  vertical  position,  contain  a  few 
vestiges  of  animal  beings,  especially  shells.  These  have  been  called  transition,  to  indicate 
their  being  the  passing  links  between  the  first  and  second  systems  of  ancient  deposites ; 
they  are  distinguished  by  the  fractured  and  cemented  texture  of  their  planes,  for  which 
reason  they  are  sometimes  called  conglomerate. 

Between  these  and  the  truly  secondary  rocks,  another  verj-^  valuable  series  is  interposed 
in  certain  districts  of  the  globe ;  namely,  the  coal-measures,  the  paramount  formation  of 
Great  Britain.  The  coal  strata  are  disposed  in  a  basin-form,  and  alternate  with  parallel 
beds  of  sandstone,  slate-clay,  iron-stone,  and  occasionally  limestone.  Some  geologists 
have  called  the  coal-measures  the  medial  formation. 

In  every  mineral  plane,  the  inclination  and  direction  are  to  be  noted ;  the  former  being 
the  angle  which  it  forms  with  the  horizon,  the  latter  the  point  of  the  azimuth  or  horizon, 
towards  which  it  dips,  as  west,  north-east,  south,  &c.  The  direction  of  the  bed  is  that 
of  a  horizontal  line  drawn  in  its  plane ;  and  wJiich  is  also  denoted  by  the  point  of  the 
compass.  Since  the  lines  of  direction  and  inclination  are  at  right  angles  to  each  other, 
the  first  may  always  be  inferred  from  the  second  ;  for  when  a  stratum  is  said  to  dip  to  the 
east  or  west,  this  implies  that  its  direction  is  north  and  south. 

The  smaller  sinuosities  of  the  bed  are  not  taken  into  account,  just  as  the  windings  of 
a  river  are  neglected  in  stating  the  line  of  its  course. 

Masses  are  mineral  deposites,  not  extensively  spread  in  parallel  planes,  but  irregular 
heaps,  rounded  or  oval,  enveloped  in  whole  or  in  a  great  measure  by  rocks  of  a  ditferent 
kind.  Lenticular  masses  being  frequently  placed  between  two  horizontal  or  inclined 
strata,  have  been  sometimes  supposed  to  be  stratiform  themselves,  and  have  been  accord- 
ingly denominated  by  the  Germans  liegende  stocke,  lying  heaps  or  blocks. 

The  orbicular  masses  often  occur  in  the  interior  of  unstratified  mountains,  or  in  the 
bosom  of  one  bed. 

Nests,  concretions,  nodules,  are  small  masses  found  in  the  middle  of  strata ;  the  first  be- 
ing commonly  in  a  friable  state ;  the  second  often  kidney-shaped,  or  tuberous ;  the  third 
nearly  round,  and  incrusted,  like  the  kernel  of  an  almond. 

Lodes,  or  large  veins,  are  flattened  masses,  with  their  opposite  surfaces  not  parallel, 
which  consequently  terminate  like  a  wedge,  at  a  greater  or  less  distance,  and  do  not  run 
parallel  with  the  rocky  strata  in  which  they  lie,  but  cross  them  in  a  direction  not  far 
from  the  perpendicular ;  often  traversing  several  different  mineral  planes.  The  lodes  are 
sometimes  deranged  in  their  course,  so  as  to  pursue  for  a  little  way  the  space  between 
two  contiguous  strata ;  at  other  times  they  divide  into  several  branches.  The  matter 
which  fills  the  lodes  is  for  the  most  part  entirely  different  from  the  rocks  they  pass 
through,  or  at  least  it  possesses  peculiar  features. 

This  mode  of  existence,  exhibited  by  several  mineral  substances,  but  which  has 
been  long  known  with  regard  to  metallic  ores,  suggests  the  idea  of  clefts  or  rents 
having  been  made  in  the  stratum  posterior  to  its  consolidation,  and  of  the  vacuities 
having  been  filled  with  foreign  matter,  either  immediately  or  after  a  certain  intervaL 
There  can  be  no  doubt  as  to  the  justness  of  the  first  part  of  the  proposition,  for  thero 
may  be  observed  round  many  lodes  undeniable  proofs  of  the  movement  or  dislocation  of 
the  rock ;  for  example,  upon  each  side  of  the  rent,  the  same  strata  are  no  longer  situated 
in  the  same  plane  as  before,  but  make  greater  or  smaller  angles  with  it ;  or  the  stratum 
upon  one  side  of  the  lode  is  raised  considerably  above,  or  depressed  considerably  below, 
its  counterpart  upon  the  other  side.  With  regard  to  the  manner  in  which  the  rent  has 
been  filled,  different  opinions  may  be  entertained.  In  the  lodes  which  are  widest  near 
■  the  surface  of  the  ground,  and  graduate  into  a  thin  wedge  below,  the  foreign  matter 
would  seem  to  have  been  introduced  as  into  a  funnel  at  the  top,  and  to  have  carried 
along  with  it  in  its  fluid  state  portions  of  rounded  gravel  and  organic  remains.  In 
other  cases,  other  conceptions  seem  to  be  more  probable  ;  since  many  lodes  are  largest 
at  their  under  part,  and  become  progressively  narrower  as  they  approach  the  surface  j 
from  which  circumstance  it  has  been  inferred  that  the  rent  has  been  caused  by  ao 


MINES. 


ler 


expansive  force  acting  from  within  the  earth,  and  that  the  foreign  matter,  having  been 
injected  in  a  fluid  state,  has  afterwards  slowly  crystallized.  This  hypothesis  accounU 
much  belter  than  the  other  for  most  of  the  phenomena  observable  in  mineral  veins,  for 
the  alterations  of  the  rock  at  their  sides,  for  the  crystallization  of  the  different  substances 
interspersed  in  them,  for  the  cavities  bestudded  with  little  crystals,  and  for  many  minute 
peculiarities.  Thus,  the  large  crystals  of  certain  substances  which  line  the  walls  of^ 
Hollow  veins,  have  sometimes  their  under  surfaces  besprinkled  with  small  cr5-stals  of 
sulphurets.  arseniurets,  &c.,  while  their  upper  surfaces  are  quite  smooth ;  suggesting 
the  idea  of  a  slow  sublimation  of  these  volatile  matters  from  below,  by  the  residual 
heat,  and  their  condensation  upon  the  under  faces  of  the  crystalline  bodies,  already 
cooled.  This  phenomenon  affords  a  strong  indication  of  the  igneous  origin  of  metalli- 
ferous veins. 

In  the  lodes,  the  principal  matters  which  fill  them  are  to  be  distinguished  from  the 
accessory  substances  ;  the  latter  being  distributed  irregularly,  amidst  the  mass  of  the  first, 
in  crystals,  nodules,  grains,  seams,  &c.  The  non-metalliferous  exterior  purtion,  which  is 
often  the  largest,  is  called  gangue,  from  the  German  gang,  vein.  The  position  of  a  vein 
is  denoted,  like  that  of  the  strata,  by  the  angle  of  inclination,  and  the  point  of  the  horizon 
towards  which  they  dip,  whence  the  direction  is  deduced. 

Veins,  are  merely  small  lodes,  which  sometimes  traverse  the  great  ones,  ramifying  i* 
various  directions,  and  in  different  degrees  of  tenuity. 

A  metalliferous  substance  is  said  to  be  disseminated,  when  it  is  dispersed  in  crystals.. 
spansles,  scales,  globules,  &c.,  through  a  large  mineral  mass. 

Certain  ores  which  contain  the  metals  most  indispensable  to  human  necessities,  have 
been  treasured  up  by  the  Creator  in  very  bountiful  deposites ;  constituting  either  great 
masses  in  rocks  of  different  kinds,  or  distributed  in  lodec,  veins,  nests,  concretions,  or  beds 
with  stony  and  earthy  admLxtures  ;  the  whole  of  which  become  the  objects  of  mineral  ex- 
ploration. These  precious  stores  occur  in  different  stages  of  the  geological  formations ; 
but  their  main  portion,  after  having  existed  abundantly  in  the  several  orders  of  the  pri- 
mary strata,  suddenly  cease  to  be  found  towards  the  middle  of  the  secondary.  Iron  ores 
are  the  only  ones  which  continue  among  the  more  modern  deposites,  even  so  high  as  the 
beds  immediately  beneath  the  chalk,  when  they  also  disappear,  or  exist  merely  as  color- 
ing matters  of  the  tertiary  earthy  beds. 

The  strata  of  gneiss  and  mica-slate  constitute  in  Europe  the  grand  metallic  domain. 
There  is  hardly  any  kind  of  ore  which  does  not  occur  there  in  suflicient  abundance  to 
become  the  object  of  mining  operations,  and  many  are  found  nowhere  else.  The  tran- 
sition rocks,  and  the  lower  part  of  the  secondary  ones,  are  not  so  rich,  neither  do  they 
contain  the  same  variety  of  ores.  But  this  order  of  things,  which  is  presented  by  Great 
Britain,  Germany,  France,  Sweden,  and  Norway,  is  far  from  forming  a  general  law ;  since 
in  equinoctial  America  the  gneiss  is  but  little  metalliferous ;  while  the  superior  strata, 
such  as  the  clay-schists,  the  sienilic  porphyries,  the  limestones,  which  complete  the  tran- 
sition series,  as  also  several  secondarj'  deposites,  include  the  greater  portion  of  the  immense 
minei-al  wealth  of  that  region  of  the  globe. 

All  the  substances  of  which  the  ordinary  metals  form  the  basis,  are  not  equally  abundant 
in  nature  ;  a  great  proportion  of  the  numerous  mineral  species  which  figure  in  our  classsi- 
fications,  are  mere  varieties  scattered  up  and  down  in  the  cavities  of  the  great  masses  or 
lodes.  The  workable  ores  are  few  in  number,  being  mostly  sulphurets,  some  oxydes,  and 
carbonates.  These  occasionally  form  of  themselves  very  large  masses,  but  more  frequent- 
ly they  are  blended  with  lumps  of  quartz,  feldspar,  and  carbonate  of  lime,  which  form  the 
main  body  of  the  deposite  ;  as  happens  always  in  proper  lodes.  The  ores  in  that  case  are 
arranged  in  small  layers  parallel  to  the  strata  of  the  formation,  or  in  small  veins  which 
traverse  the  rock  in  all  directions,  or  in  nests  or  concretions  stationed  irregularly,  or 
finally  disseminated  in  hardly  visible  particles.  These  deposites  sometimes  contain  appa- 
rently only  one  species  of  ore,  sometimes  several,  which  must  be  mined  together,  as  they 
seem  to  be  of  contemporaneous  formation ;  whilst,  in  other  cases,  they  are  separable, 
having  been  probably  formed  at  difi'erent  epochs.  In  treating  of  the  several  metals  in 
their  alphabetical  order,  I  have  taken  care  to  describe  their  peculiar  geological  positions, 
and  the  rocks  which  accompany  or  mineralize  them. 

In  mining,  as  in  architecture,  the  best  method  of  imparting  instruction  is  to  display 
the  master-pieces  of  the  respective  arts,  which  speak  clearly  to  the  mind  throug:h  the 
medium  of  the  eye.  It  is  not  so  easy,  however,  to  represent  at  once  the  general  effect  of 
a  mine,  as  it  is  of  an  edifice ;  because  there  is  no  point  of  sight  from  which  the  former 
can  be  sketched  at  once,  like  the  latter.  The  subterraneous  structures  certainly  afford 
some  of  the  finest  examples  of  the  useful  labors  of  man,  continued  for  ages,  under  the 
guidance  of  science  and  ingenuity ;  but,  however  curious,  beautiful,  and  grand  in  them- 
selves, they  cannot  become  objects  of  a  panoramic  view.  It  is  only  by  the  lights  of  ge- 
ometry and  geology  that  mines  can  be  contemplated  and  surveyed,  either  as  a  whole  or  ii\ 
their  details  j  and,  therefore,  these  marvellous  subterranean  regions,  in  which  roads  are  col 

/ 


t  , 


I 


;    I 


168 


MINES. 


many  hundred  miles  long,  are  altogether  unknown  or  disregarded  by  men  of  the  wcrW. 
Shonld  any  of  them,  perchance,  from  curiosity  or  interest,  descend  into  these  dark 
recesses  of  the  earth,  they  are  prepared  to  discover  only  a  few  insulated  objects  which  they 
may  think  strange  or  possibly  hideous ;  but  they  cannot  recognise  either  the  symmetrical 
disposition  of  mineral  bodies,  or  the  laws  which  govern  geological  phenomena,  and 
B^rve  as  sure  guides  to  the  skilful  miner  in  his  adventurous  search.  It  is  by  exact 
plans  and  sections  of  subterraneous  workings,  that  a  knowledge  of  the  nature,  extent, 
and  distribution  of  mine.al  wealth  can  be  acquired. 


931 

.    A  general  view  of  mining  operations. 

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As  there  is  no  country  in  the  world  so  truly  rich  and  powerful,  by  virtue  of  its  mineral 
stores,  as  Great  Britain,  so  there  are  no  people  who  ought  to  take  a  deeper  interest  in 
their  scientific  illustration.  I  have  endeavored  in  the  present  article  to  collect  from 
the  most  authentic  sources  the  most  interesting  and  instructive  examples  of  mining 
operations. 

To  the  magnificent  work  of  Ville-Fosse,  Sur  la  Richesse  Minerale,  no  longer  on  sale, 
I  have  to  acknowledge  weighty  obligations ;  many  of  the  figures  being  copied  from  his 
great  Atlas. 

Lodes  or  mineral  veins  are  usually  distinguished  by  English  miners  into  at  least  four 
ftpecies.  1.  The  rake  vein.  2.  The  pipe  vein.  3.  The  flat  or  dilated  vein ;  and  4. 
The  interlaced  mass  (stock-werke),  indicating  the  union  of  a  multitude  of  small  veins 
mixed  in  every  possible  direction  with  each  other,  and  with  the  rock. 

1.  The  rake  vein  is  a  perpendicular  mineral  fissure ;  and  is  the  form  best  known 
among  practical  miners.  It  commonly  runs  in  a  straight  line,  beginning  at  the  super- 
ficies  of  the  strata,  and  cutting  them  downwards,  generally  further  than  can  be  reached. 
This  vein  sometimes  stands  quite  perpendicular;  but  it  more  usually  inclines  or  hangs 
over  at  a  greater  or  smaller  angle,  or  slope,  Avhich  is  called  by  the  miners  the  hade  ox 
hading  of  the  vein.  The  line  of  direction  in  which  the  fissure  runs,  is  called  the  beann^ 
of  the  vein. 

2.  The  pipe  vein  resembles  in  many  respects  a  huge  irregular  cavern,  pushing  forward 
into  the  body  of  the  earth  in  a  sloping  direction,  under  various  inclinations,  frorh  an 
angle  of  a  few  degrees  to  the  horizon,  to  a  dip  of  45°,  or  more.  The  pipe  does  not  in 
general  cut  the  strata  across  like  the  rake  vein,  but  insinuates  itself  between  them ;  so 
that  if  the  plane  of  the  strata  be  nearly  horizontal,  the  bearing  of  the  pipe  vein  will  be 
eonformable ;  but  if  the  strata  stand  up  at  a  high  angle,  the  pipe  shoots  down  nearly 
headlong  like  a  shaft.  Some  pipes  are  very  wide  and  high,  others  are  very  low  and 
narrow,  sometimes  not  largei  than  a  common  mine  or  drift. 

3.  The  Jlat  or  dilated  vein,  is  a  space  or  opening  between  two  strata  or  beds  of  stone, 
the  one  of  which  lies  above,  and  the  other  below  this  vein,  like  a  stratum  of  coal 


MINES. 


169 


between  its  roof  and  pavement ;  so  that  the  vein  and  the  strata  are  placed  in  the  same 
plane  of  inclination.  These  veins  are  subject,  like  coal,  to  be  interrupted,  broken,  and 
thrown  up  or  down  by  slips,  dikes,  or  other  interruptions  of  the  regular  strata.  In  the 
case  of  a  metallic  vein,  a  slip  often  increases  the  chance  of  finding  more  treasure.  Such 
veins  do  not  preserve  the  parallelism  of  their  beds,  characteristic  of  coal  seams ;  but 
vary  excessively  in  thickness  within  a  moderate  space.  Flat  veins  occur  frequently  in 
limestone,  either  in  a  horizontal  or  declining  direction.  The  flat  or  strata  veins  open  and 
close,  as  the  rake  veins  also  do. 

4.  The  interlaced  mass  has  been  already  defined. 

To  these  may  be  added  the  accumulated  vein,  or  irregdiar  mass  (Jtmtzenwerke),  a  great 
deposite  placed  without  any  order  in  the  bosom  of  the  rocks,  apparently  filling  up  cavern- 
ous spaces. 

The  interlaced  masses  are  more  frequent  in  primitive  formations,  tnan  m  the  others ; 
and  tin  is  the  ore  which  most  commorily  affects  this  locality.    See  figure  of  Tin  mine. 

The  study  of  the  mineral  substances,  called  gangues  or  vein-stones,  which  usually 
accompany  the  different  ores,  is  indispensable  in  the  investigation  and  working  of  mines. 
These  gangues,  such  as  quartz,  calcareous  spar,  fljior  spar,  heavy  spar,  &c.,  and  a  great 
number  of  other  substances,  although  of  little  or  no  value  in  themselves,  become  of  great 
consequence  to  the  miner,  either  by  pointing  out  by  their  presence  that  of  certain  useful 
minerals,  or  by  characterizing  in  their  several  associations,  different  deposites  of  ores  of 
which  it  may  be  possible  to  follow  the  traces,  and  to  discriminate  the  relations,  often  of  a 
complicated  kind,  provided  we  observe  assiduously  the  accompanying  gangues. 

Mineral  veins  are  subject  to  derangements  in  their  course,  which  are  called  shifts  or 
faults.  Thus,  when  a  transverse  vein  throws  out,  or  intercepts,  a  longitudinal  one,  we 
must  commonly  look  for  the  rejected  vein  on  the  side  of  the  obtuse  angle  which  the 
direction  of  the  latter  makes  with  that  of  the  former.  When  a  bed  of  ore  is  deranged 
by  a  fault,  we  must  observe  whether  the  slip  of  the  strata  be  upwards  or  downwards ;  for 
in  either  circumstance,  it  is  only  by  pursuing  the  direction  of  the  fault  that  we  can 
recover  the  ore ;  in  the  former  case  by  mounting,  in  the  latter  by  descending  beyond 
the  dislocation. 

When  two  veins  intersect  each  other,  the  direction  of  the  offcast  is  a  subject  of  interest, 
both  to  the  miner  and  the  geologist.  In  Saxony  it  is  considered  as  a  general  fact  that 
the  portion  thrown  out  is  always  upon  the  side  of  the  obtuse  angle,  a  circumstance  which 
holds  also  in  Cornwall ;  and  the  more  obtuse  the  angle,  the  out-throw  is  the  more  con- 
siderable. A  vein  may  be  thrown  out  on  meeting  another  vein,  in  a  line  which  approaches 
either  towards  its  inclination  or  its  direction.  The  Cornish  miners  use  two  different 
terms  to  denote  these  two  modes  of  rejection ;  for  the  first  case,  they  say  the  vein  is 
beared ;  for  the  second,  it  is  started. 

The  great  copper  lode  of  Carharack,  d^fig.  932,  in  the  parish  of  Gwenap,  is  one  of  the 

most  instructive  examples  of  intersection.     The  power 
or  thickness  of  this  vein  is  8  feet ;  its  direction  is 
nearly  due  east  and  west,  and   it  dips  towards  the 
north  at  an  inclination  of  two  feet  per  fathom ;  its 
upper  part  being  in  the  killas  (a  greenish  clay-slate) ; 
its  lower  part  in  the  granite.      The  lode  has  suflTered 
two  intersections ;  the  first  produced  by  meeting  the 
vein  A,  called  Steven's  Jluckan,  which  runs  from  north- 
east   to    south-west,    and    which    throws    the    lode 
several    fathoms  out ;   the  second    is    producxl    by 
another  vein  i,  almost  at  right  angles  with  the  first,  and  which  occasions  another  out- 
throw  of  20  fathoms  to  the  right  side.      The  fall  of  the  vein  occurs  therefore  in  the  one 
case  to  the  right,  and  in  the  other  to  the  left ;  but  in  both  it  is  towards  the  side  of  the 
obtuse  angle.      This  distribution  is  very  singular ;  for  one  part  of  the  vein  appears  to 
have  mounted  while  the  other  has  descended,      n.  s.  denotes  North  and  South,     d  is 
the  copper  lode  running  east  and  west.     A,  i,  are  systems  of  clay-slate  veins  called 
fluckans ;  the  line  over  s,  represents  the  down  shift,  and  d'  the  up-shift. 

General  observations  on  the  localities  of  ores,  and  on  the  indications  of  metallic  mines, 

1 .  Tin  exists  principally  in  primitive  rocks,  appearing  either  in  interlaced  masses,  in 
beds,  or  as  a  constituent  part  of  the  rock  itself,  and  more  rarely  in  distinct  veins.  Tin 
ore  is  found  indeed  sometimes  in  alluvial  land,  filling  up  low  situations  between  lofty 
mountains. 

2.  Gold  occurs  either  in  beds  or  in  veins,  frequently  in  primitive  rocks ;  though  in 
other  formations,  and  particularly  in  alluvial  earth,  it  is  also  found.  When  this  metal 
exists  in  the  bosom  of  primitive  rocks,  it  is  particularly  in  schists ;  it  is  not  found  in  serpen- 
tine, but  it  is  met  with  in  graywacke  in  Transylvania.    The  gold  of  alluvial  districts. 


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170 


MINES. 


called  gold  of  washing  or  transport,  occurs,  as  well  as  alluvial  tin,  among  the  debiis  of 

the  more  ancient  rocks. 

3.  Silver  is  found  particularly  in  veins  and  beds,  in  primitive  and  transition  formations ; 
though  some  veins  of  this  metal  occur  in  secondary  strata.  The  rocks  richest  in  it  are; 
gneiss,  mica-slate,  clay-slate,  graywacke,  and  old  alpine  limestone.  Localities  of  silver- 
ore  itself  are  not  numerous,  at  least  in  Europe,  among  secondary  formations;  but  it 
occurs  in  combination  with  the  ores  of  copper  or  of  lead. 

4.  Copper  exists  in  the  three  mineral  epochas  ;  1 .  in  primitive  rocks,  principally  in  the 
state  of  pyritous  copper,  in  beds,  in  masses,  or  in  veins ;  2.  in  transition  districts,  some- 
times in  masses,  sometimes  in  veins  of  copper  pyrites ;  3.  in  secondary  strata,  especially 
in  beds  of  cupreous  schist. 

5.  Lead  occurs  also  in  each  of  the  three  mineral  epochas ;  abounding  particularly  in 
primitive  and  transition  grounds,  where  it  usually  constitutes  veins,  and  occasionally  beds 
of  sulphureted  lead  (£?alena).  The  same  ore  is  found  in  strata  or  in  veins  among 
secondary  rocks,  associated  now  and  then  with  ochreous  iron-oxyde  and  calamine 
(carbonate  of  zinc) ;  and  it  is  sometimes  disseminated  in  grains  through  more  recent 

6.  iron  is  met  with  in  four  different  mineral  eras,  but  in  different  ores.  Among  primi- 
tive rocks,  magnetic  iron  ore  and  specular  iron  ore  occur  chiefly  in  beds,  sometimes  of 
enormous  size;  the  ores  of  red  or  brown  oxyde  of  iron  (hematite)  are  found  generally  in 
veins,  or  occasionally  in  masses  with  sparry  iron,  both  in  primitive  and  transition  rocks ; 
as  also  sometimes  in  secondary  strata ;  but  more  frequently  in  the  coal-measure  strata,  as 
beds  of  clay-ironstone,  of  globular  iron  oxyde,  and  carbonate  of  iron.  In  alluvial  districts 
we  find  ores  of  clay-ironstone,  granular  iron-ore,  bog-ore,  swamp-ore,  and  meadow-ore. 
The  iron  ores  which  belong  to  the  primitive  period  have  almost  always  the  metallic  aspect, 
with  a  richness  amounting  even  to  80  per  cent,  of  iron,  while  the  ores  in  the  posterior 
formations  become  in  general  more  and  more  earthy,  down  to  those  in  alluvial  soils,  some 
of  which  present  the  appearance  of  a  common  stone,  and  afford  not  more  than  20  per 
cent,  of  metal,  though  its  quality  is  oflen  excellent. 

7.  Mercury  occurs  principally  among  secondary  strata,  in  disseminated  masses,  along 
with  combustible  substances;  though  the  metal  is  met  with  occasionally  in  primitive 

countries. 

8.  Cobalt  belongs  to  the  three  mineral  epochas ;  its  most  abundant  deposites  are  vems 
in  primitive  rocks ;  small  veins  containing  this  metal  are  found,  however,  in  secondary 
strata. 

9.  jlrUimmy  occurs  in  veins  or  beds  among  primitive  and  transition  rocks. 

10.  11.  Bismuth  and  nickel  do  not  appear  to  constitute  the  predominating  substance 
of  any  mineral  deposites ;  but  they  often  accompany  cobalt. 

12.  Zinc  occurs  in  the  three  several  formations :  namely,  as  sulphuret  or  blende,  partic- 
ularly in  primitive  and  transition  rocks ;  as  calamine,  in  secondary  strata,  usually  along 
with  oxyde  of  iron,  and  sometimes  with  sulphuret  of  lead. 

An  acquaintance  with  the  general  results  collected  and  classified  by  geology  must  be 
our  first  guide  in  the  investigation  of  mines.  This  enables  the  observer  to  judge  whether 
any  particular  district  should,  from  thp  nature  and  arrangement  of  its  rocks,  be  suscepti. 
ble  of  including  within  its  bosom,  beds  of  workable  ores;  it  indicates  also,  to  a  certain 
desree,  what  substances  may  probably  be  met  with  in  a  given  series  of  rocks,  and  what 
loc'ality  these  substances  will  preferably  affect.  For  want  of  a  knowledge  of  these  facts, 
many  persons  have  gone  blindly  into  researches  equally  absurd  and  ruinous. 

Formerly,  indications  of  mines  were  taken  from  very  unimportant  circumstances; 
from  thermal  waters,  the  heat  of  which  was  gratuitously  referred  to  the  decomposition  of 
pyrites  ;  from  mineral  waters,  whose  course  is  however  often  from  a  far  distant  source  ; 
from  vapors  incumbent  over  particular  mountain  groups ;  from  the  snows  melting  faster 
in  one  mineral  district  than  another ;  from  the  different  species  of  forest  trees,  and  from 
the  "reater  or  less  visor  of  vegetation,  &c.  In  general,  all  such  indications  are  equally 
fallacious  with  the  divining  rod,  and  the  compass  made  of  a  lump  of  pyrites  suspended  by 

a  thread. 

Geogtwstic  observation  has  substituted  more  rational  characters  of  metallic  deposites, 
some  of  which  may  be  called  negative  and  others  positive. 

The  negative  indications  are  derived  from  that  peculiar  geological  constitution,  which 
from  experience  or  general  principles  excludes  certain  metallic  matters ;  for  example, 
granite,  and  in  general  every  primitive  formation,  forbids  the  hope  of  finding  within  them 
combustible  fossils  (pit-coal,)  unless  it  be  beds  of  anthracite ;  there  also  it  would  be  vain 
to  seek  for  sal  gem.  It  is  very  seldom  that  granite  rocks  include  silver ;  or  limestones, 
ores  of  tin.  Volcanic  territories  never  afford  any  metallic  ores  worth  the  working;  nor 
do  extensive  veins  usually  run  into  secondary  and  alluvial  formations.  The  richei  ores 
of  iron  do  not  occur  in  secondary  strata ;  and  the  ores  of  this  metal  peculiar  to  these 
localities,  do  not  exist  among  primary  rocks. 


MINES. 


171 


Amon"  positive  indications,  some  are  proximate  and  others  remote.  The  proximate 
are  an  efflorescence,  so  to  speak,  of  the  subjacent  metaUic  masses;  magnetic  attractiou 
for  iron  ores ;  bituminous  stone,  or  inflammable  gas  for  pit-coal ;  the  frequent  occurrence 
of  fra«'ments  of  particular  ores,  &c.  The  remote  indications  consist  in  the  geological 
epocha,  and  nature  of  the  rocks.  From  the  examples  previously  adduced,  marks  of 
this  kind  acquire  new  importance  when  in  a  district  susceptible  of  including  deposites  of 
workable  ores,  the  gangues  or  vein-stones  are  met  with  which  usually  accompany  any 
particular  metal.  The  general  aspect  of  mountains  whose  flanks  present  gentle  and 
continuous  slopes,  the  frequency  of  sterile  veins,  the  presence  of  metalliferous  sands,  the 
nei^-hborhood  of  some  known  locality  of  an  ore,  for  instance,  that  of  iron-stone  in 
reference  to  coal,  lastly,  the  existence  of  salt  springs  and  mineral  waters,  may  furnish 
M)me  indications ;  but  when  ferruginous  or  cupreous  waters  issue  from  sands  or  clays, 
such  characters  merit  in  general  little  attention,  because  the  waters  may  flow  from  a  great 
distance.     No  greater  importance  can  be  attached  to  metalliferous  sands  and  saline 

springs.  ,     .       .  ,     ,  j        *• 

In  speaking  of  remote  indications,  we  may  remark  that  in  several  places,  and  partic- 
ulariy  near  Clausthal  in  the  Hartz,  a  certain  ore  of  red  oxyde  of  iron  occurs  above  the 
most  abundant  deposites  of  the  ores  of  lead  and  silver;  whence  it  has  been  named  by 
the  Germans  the  iron^at.  II  appears  that  the  iron  ore  rich  in  silver,  whicu  is  worked 
in  America  under  the  name  oipacos,  has  some  analogy  with  this  substance ;  but  iron  ore 
is  in  general  so  plentifully  diffused  on  the  surface  of  the  soil,  that  its  presence  can  be  re- 
garded as  only  a  remote  indication,  relative  to  other  mineral  substances,  except  in  the 

case  of  clav  iron-stone  with  coal.  t   •    v     v       -a    e 

Of  the  instruments  and  operations  of  subterranean  operations.— It  is  by  the  aid  ot  ge- 
ometry in  the  first  place  that  the  miner  studies  the  situation  of  the  mineral  deposites,  on 
the  surface  and  in  the  interior  of  the  ground ;  determines  the  several  relations  of  the 
veins  and  the  rocks ;  and  becomes  capable  of  directing  the  perforations  towards  a  suitable 

The  instruments  are,  1.  the  magnetic  compass,  which  is  employed  to  measure  the 
direction  of  a  metallic  ore,  wherever  the  neighborhood  of  iron  does  not  interfere  with  its 
functions ;  2.  the  graduated  semi-circle,  which  serves  to  measure  the  inclination,  which  is 
also  called  the  clinometer. 

3.  The  chain  or  cord  for  measuring  the  distance  of  one  point  from  another. 

4.  When  the  neighborhood  of  iron  renders  the  use  of  the  magnet  uncertain,  a  plate  or 

plane  table  is  employed.  .  j     .^ 

The  dials  of  the  compasses  generally  used  in  the  most  celebrated  mines,  are  graduatea 

into  hours;  most  commonly  into  twice  12  hours.     Thus  the  whole  limb  is  divided  into 

24  spaces,  each  of  which  contains  15°  =  1  hour.    Each  hour  is  subdivided   into  8 

^^Means  of  penetrating  into  the  interior  of  the  earth.— In  order  to  penetrate  into  the  inte- 
rior of  the  earth,  and  to  extract  from  it  the  objects  of  his  toils,  the  miner  has  at  his  dis- 
posal several  means,  which  may  be  divided  into  three  classes;  1.  manual  toolsy  2.  gtt»- 

powderftindS.Jire.  ..     r  n      • 

The  tools  used  bv  the  miners  of  Cornwall  and  Devonshire  are  the  following : 
Fig,  933.  The  pick.     It  is  a  light  tool,  and  somewhat  varied  in  shape  according  to  ar- 

935  938 

986  n       V\ 


comstances.  One  side  used  as  a  hammer  is  called  the  pally  and  is  employed  to  drive  in 
the  gads,  or  to  loosen  and  detach  prominences.  The  point  is  of  steel,  carefully  tempered, 
and  drawn  under  the  hammer  to  the  proper  form.    The  French  call  it  pointerolU,    / 


I' 


ii; 


m 


172 


MINES. 


Fig.  934.  The  gad.  It  is  a  wedge  of  steel,  driven  into  crevices  of  rocks,  or  into  small 
openings  made  with  the  point  of  the  pick. 

Fig.  935  The  miner^s  shovel.  It  has  a  pointed  form,  to  enable  it  to  penetrate  among 
the  coarse  and  hard  fragments  of  the  mine  rubbish.  Its  handle  being  somewhat  bent,  a 
man's  power  may  be  convenienlly  applied  without  bending  his  body. 

The  blasting  or  shooting  tools  are : — 


A  sledge  or  mallet 
Borer 

Claying  bar 
Needle  or  nail 
Scraper 
Tamping  bar 


fig.  986. 

—  937. 

—  938. 

—  939. 

—  940. 

—  941. 


Besides  these  tools  the  miner  requires  a  powder-horn,  rushes  to  be  filled  with  gunpow- 
der, tin  cartridges  for  occasional  use  in  wet  ground,  and  paper  rubbed  over  with  gunpow- 
der or  srease,  for  the  smi//*  or  fuses. 

The  6orcr,  yig.  937,  is  an  iron  bar  tipped  with  steel,  formed  like  a  thick  chisel,  and 
is  used  by  one  man  holding  it  strai2:ht  in  the  hole  with  constant  rotation  on  its  axis,  while 
another  strikes  the  head  of  it  with  the  iron  sledge  or  mallet,  fig.  936.  The  hole  is  cleared 
out  from  time  to  time  by  the  scraper,  yjg.  940,  which  is  a  flat  iron  rod  turned  up  at  one 
end.  If  the  ground  be  very  wet,  and  the  hole  gets  full  of  mud,  it  is  cleaned  out  by  a  stick 
bent  at  the  end  into  a  fibrous  brush,  called  a  swab-stick. 

Fig.  942  represents  the  plan  of  blastins:  the  rock,  and  a  section  of  a  hole  ready  for 

firing.  The  hole  must  be  rendered  as 
drj'  as  possible,  which  is  effected  very 
simply  by  filling  it  partly  with  tenaci- 
ous clay,  and  then  driving  into  it  a 
tapering  iron  rod,  which  nearly  fills  its 
calibre,  called  the  claying  bar.  This 
being  forced  in  with  great  violence, 
condenses  the  clay  into  all  the  crevices 
of  the  rock,  and  secures  the  dryness  of 
the  hole.  Should  this  plan  fail,  re- 
course is  had  to  tin  cartridges  furnish- 
ed with  a  stem  or  tube,  (see  fig.  943,) 
through  which  the  powder  may  be  in- 
^  flamed.      When   the    hole  is  dry,  and 

the  charge  of  powder  introduced,  the  nail,  a  small  taper  rod  of  copper,  is  inserted  so  as 
to  reach  the  bottom  of  the  hole,  which  is  now  ready  for  tamping.  By  this  difficult  and 
dangerous  process,  the  gunpowder  is  confined,  and  the  disruptive  effect  produced. 
Difllerent  substances  are  employed  for  tamping,  or  cramming  the  hole,  the  most  usual 
one  being  any  sofl  species  of  rock  free  from  silicious  or  flinty  particles.  Small  quan- 
tities of  it  only  are  introduced  at  a  lime,  and  rammed  very  hard  by  the  tamping-bar, 
which  is  held  steadily  by  one  man,  and  struck  with  a  sledge  by  another.  The  hole 
being  thus  filled,  the  nail  is  withdrawn  by  putting  a  bar  through  its  eye,  and  striking 
it  upwards.  Thus  a  small  perforation  or  vent  is  left  for  the  rush  which  communicates 
the  fire. 

Besides  the  improved  tamping-bar  faced  with  hard  copper,  other  contrivances  have 
been  resorted  to  for  diminishing  the  risk  of  those  dreadful  accidents  that  frequently  occur 
in  this  operation.  Dry  sand  is  sometimes  used  as  a  tamping  material,  but  there  are  many 
rocks  for  the  blasting  of  which  it  is  ineffective.    Tough  clay  will  answer  better  in  several 

situations. 

For  conveying  the  fire,  the  large  and  long  green  rushes  which  grow  in  marshy 
ground  are  selected.  A  slit  is  made  in  one  side  of  the  rush,  along  which  the  sharp 
end  of  a  bit  of  stick  is  drawn,  so  as  to  extract  the  pith,  when  the  skin  of  the  rush  closes 
again  by  its  own  elasticity.  This  tube  is  filled  up  with  gunpowder,  dropped  into  the 
vent-hole,  and  made  steady  with  a  bit  of  clay.  A  paper  smift,  adjusted  to  burn  a  proper 
time,  is  then  fixed  to  the  top  of  the  rush-tube,  and  kindled,  when  the  men  of  the  mine  re- 
tire to  a  safe  distance. 

In  fig.  942  the  portion  of  the  rock  which  would  be  dislodged  by  the  explosion,  is 
that  included  between  a  and  b.  The  charge  of  powder  is  represented  by  the  white  part 
which  fills  the  hole  up  to  c  ;  from  which  point  to  the  top,  the  hole  is  filled  with  tamping. 
The  smift  is  shown  at  d. 

Fig.  944  is  an  iron  bucket,  or  as  it  is  calk  d  in  Cornwall,  a  kibble,  in  which  the  ore 
Is  raised  in  the  shafts,  by  machines  called  whims,  worked  by  horses.    The  best  kibbloe 


MINES.  17J 

are  made  of  sheet-iron,  and  hold  each  about  three  hundred  weight  of  ore  :    120  kibbles 
are  supposed  to  clear  a  cubic  fathom  of  rock. 

945 


Fig.  945  represents  the  wheelbarrow  used  under  ground  for  conveying  ore  and  waste 
to  the  foot  of  the  shafts.  It  is  made  of  light  deal,  except  the  wheel,  which  has  a  narrow 
rim  of  iron. 

Fig.  946  represents  Mr.  Taylor's  ingenious  ventilator,  or  machine  for  renewing  fresh 
air  in  mines.  It  is  so  simple  in  construction,  so  complete  in  its  operation,  requFres  so 
little  power  to  work  it,  and  is  so  little  liable  to  injury  from  wear,  that  nothing  further 
of  the  kind  can  be  desired  in  ordinary  metallic  mines.  The  shaft  of  the  mine^is  repre- 
sented at  A ;  at  either  the  top  or  bottom  of  which  the  machine  may  be  placed,  as  is 
found  most  convenient,  but  the  foul  air  must  be  discharged  into  a  floor,  furnished'  with 
a  valve-door  to  prevent  its  return  into  the  mine,  b  is  the  air-pipe  from  the  mine,  pass- 
ing through  the  bottom  of  the  fixed  vessel  or  cylinder  c,  which  is  formed  of  timber,  and 
bound  with  iron  hoops.  It  is  filled  with  water  nearly  to  the  top  of  the  pipe  b,  on  which 
is  fixed  a  valve  opening  upwards  at  d.  e,  the  air,  or  exhausting  cylinder  of  cast-iron, 
open  at  bottom,  and  suspended  over  the  air-pipe,  but  immersed  some  way  in  the  water. 
It  is  furnished  with  a  wooden  top,  having  an  aperture  fitted  with  a  valve  likewise  open- 
ing upwards  at  f.  This  exhausting  cylinder  is  moved  up  and  down  by  the  bob,  g,  brought 
into  connexion  with  any  engine,  by  the  horizontal  rod  h  ;    the  weight  of  the  cylinder 

being  balanced,  if  necessary,  by  the  counterpoise  i.     The  action  is  as  follows  : When 

the  cylinder  rises,  the  air  from  the  mine  rushes  up  through  the  pipe  and  valve  d  ;  and 
when  it  descends,  this  valve  shuts,  and  prevents  the  return  of  the  air,  which  is  expelled 
through  the  valve  f.  With  a  cylinder  two  feet  in  diameter  and  six  feet  long,  working 
from  two  to  three  strokes  per  minute,  200  gallons  of  air  may  be  discharged  in  the 
same  time. 

Gunpowder  is  the  most  valuable  agent  of  excavation  ;  possessing  a  power  which  has 
DO  limit,  and  which  can  act  everywhere,  even  under  water.    Its  introduction,  in  1615 
caused  a  great  revolution  in  the  mining  art.  ' 

It  is  employed  in  mines  in  different  manners,  and  in  different  quantities,  according  to 
circumstances.  In  all  cases,  however,  the  process  resolves  itself  into  boring  a  hole,  and 
enclosing  a  cartridge  in  it,  which  is  afterwards  made  to  explode.  The  hole  is  always 
cylindrical,  and  is  usually  made  by  means  of  the  borer,^g.  937,  a  stem  of  iron,  termi- 
nated by  a  blunt-edged  chisel.  It  sometimes  ends  in  a  cross,  formed  by  two  chisels  set 
transversely.  The  workman  holds  the  stem  in  his  left  hand,  and  strikes  it  with  an  iron 
mallet  held  in  his  right.  He  is  careful  to  turn  the  punch  a  very  little  round  at  every 
stroke.  Several  punches  are  employed  in  succession,  to  bore  one  hole  ;  the  first  shorteii 
the  latter  ones  longer,  and  somewhat  thinner.  The  rubbish  is  withdrawn  as  it  accumu- 
lates, at  the  bottom  of  the  hole,  by  means  of  a  picker,  which  is  a  small  spoon  or  disc 
of  iron  fixed  at  the  end  of  a  slender  iron  rod.     When  holes  of  a  large  size  are  tp  be 


i     i' 


I 


174 


MINES. 


made,  several  men  must  be  employed  ;  one  to  hold  the  punch,  and  one  or  more  to  wield 
the  iron  mallet.  The  perforations  are  seldom  less  than  an  inch  in  diameter,  and  18  inches 
deep ;  but  they  are  sometimes  two  inches  wide,  with  a  depth  of  50  inches. 

The  gunpowder,  when  used,  is  most  commonly  put  up  in  paper  cartridges.  Into  the 
side  of  the  cartridge,  a  small  cylindrical  spindle  or  piercer  is  pushed.  In  this  state  the 
cartridge  is  forced  down  to  the  bottom  of  the  hole,  which  is  then  stuffed,  by  means  of  the 
tampin?  bar,y?g.  941,  with  bits  of  dry  clay,  or  friable  stones  coarsely  pounded.*  The 
piercer  is  now  withdrawn,  which  leaves  in  its  place  a  channel  through  which  fire  may  be 
conveyed  to  the  charge.  This  is  executed  either  by  pouring  gunpowder  into  that  passage, 
or  by  'inserting  into  it  reeds,  straw  stems,  quills,  or  tubes  of  paper  filled  with  gunpowder. 
This  is  exploded  by  a  long  match,  which  the  workmen  kindle,  and  then  retire  to  a  place 

of  safetv 

As  the  piercer  must  not  only  be  slender,  but  stiff,  so  as  to  be  easily  withdrawn  when 
the  hole  is  tamped,  iron  spindles  are  usually  employed,  though  they  occasionally  give 
rise  to  sparks,  and  consequently  to  dangerous  accidents,  by  their  friction  against  the  sides 
of  the  hole.     Brass  piercers  have  been  sometimes  tried ;  but  they  twist  and  break  too 

readily.  .  ,        ,  •  .         .      *. 

Each  hole  bored  in  a  mine,  should  be  so  placed  in  reference  to  the  schistose  structure 
of  the  rock,  and  to  its  natural  fissures,  as  to  attack  and  blow  up  the  least  resisting  masses. 
Sometimes  the  rock  is  prepared  beforehand  for  splitting  in  a  certain  direction,  by  means 
of  a  narrow  channel  excavated  with  the  small  hammer. 

The  quantity  of  gunpowder  should  be  proportional  to  the  depth  of  the  hole,  and  the  re- 
sistance  of  the  rock,  and  merely  sufficient  to  split  it.  Anything  additional  would  serve  no 
other  purpose  than  to  throw  the  fragments  about  the  mine,  without  increasing  the  useful 
effect.    Into  the  holes  of  about  an  inch  and  a  quarter  diameter,  and  18  inches  deep,  only  two 

ounces  of  s:unpowder  are  put.  j  ,     ,      •  *. 

It  appears  that  the  effect  of  the  gunpowder  may  be  augmented  by  leaving  an  empty 
space  above,  in  the  middle  of,  or  beneath  the  cartridge.  In  the  mines  of  Silesia,  the  con- 
sumption of  gunpowder  has  been  eventually  reduced,  without  diminishing  the  pro- 
duct of  the  blasts,  by  mixing  sawdust  with  it,  in  certain  proportions.  The  hole  has  also  been 
filled  up  with  sand  in  some  cases,  according  to  Mr.  Jessop's  plan,  instead  of  being 
packed  with  stones,  which  has  removed  the  danger  of  the  tamping  operation.  The  ex- 
periments made  in  this  way  have  given  results  very  advantageous  in  quarry  blasts 
with  great  charges  of  gunpowder ;  but  less  favorable  in  the  small  charges  employed 

in  mines.  ,  ,  ,  ^    «  , 

Water  does  not  oppose  an  insurmountable  obstacle  to  the  employment  of  gunpowder ; 
but  when  the  hole  cannot  be  made  dry,  a  cartridge  bag  impermeable  to  water  must  be  had 
recourse  to,  provided  with  a  tube  also  impermeable,  in  which  the  piercer  is  placed. 

After  the  explosion  of  each  mining  charge,  wedges  and  levers  are  employed,  to  drag 
away  and  break  down  what  has  been  shattered.  •    i       j 

Wherever  the  rock  is  tolerably  hard,  the  use  of  gunpowder  is  more  economical  and 
more  rapid  than  anv  tool-work,  and  is  therefore  always  preferred.  A  gallerj^,  for 
example,  a  yard  and  k  half  high,  and  a  yard  wide,  the  piercing  of  which  by  the  hammer 
formerlv  cost  from  five  to  ten  pounds  sterling  the  runnmg  yard,  in  Germany,  is 
executed  at  the  present  day  by  gunpowder  at  from  two  to  three  pounds.  When,  how- 
ever a  precious  mass  of  ore  is  to  be  detached,  when  the  rock  is  cavernous,  which  nearly 
nullifies  the  action  of  gunpowder,  or  when  there  is  reason  to  apprehend  that  the  shock 
caused  by  the  explosion  may  produce  an  injurious  fall  of  rubbish,  hand-tools  alone  must 

^IrTcert'ain*  rocks  and  ores  of  extreme  hardness,  the  use  both  of  tools  and  gunpowdor 
becomes  very  tedious  and  costly.  Examples  to  this  effect  are  seen,  m  the  mass  of 
quartz  mingled  with  copper  pyrites,  worked  at  Rammelsberg,  m  the  Hartz,  m  the 
masses  of  stanniferous  granite  of  Geyer  and  Altenbeig  in  the  Erzgebirge  of  Saxony, 
&c.  In  these  circumstances,  fortunately  very  rare,  the  action  of  fire  is  used  with 
advantage  to  diminish  the  cohesion  of  the  rocks  and  the  ores.  The  employment  of  this 
a^'ent  is'^not  necessarily  restricted  to  these  diflficult  cases.  It  was  formerly  applied  very 
often  to  the  working  of  hard  substances;  but  the  intio«Juctioa  of  gunpowder  into  the 
raining  art,  and  the  increase  in  the  price  of  woc^,  occasion  fire  to  be  little  used  as  an 
ordinary  means  of  excavation,  except  in  places  where  the  scantiness  of  the  poulation  has 

♦  Sir  Rose  Price  invented  a  cap  of  bronze  alloy,  to  tip  the  lower  end  of  the  iron  rod;  a  contrivance 
now  generally  usfd  in  Cornwall.  Before  the  Geological  Socirtv  of  that  county  introduced  this  mventioB 
into  practice,  scarcly  a  month  elapsed  without  some  dreadful  yxplosion  sending  the  miner  to  an  un- 
timely prave,  or  so  injuring  him  by  blown?  out  his  eyes,  or  shuttoring  his  liinbs,  as  to  render  him  a 
m-serable  object  of  chartty  for  the  rest  of  h-s  days  Scarcely  ha*  any  accident  happened  since  the  em- 
nlovmenl  of  the  new  tompin?-bar.  When  the  whole  bar  n-as  made  of  the  tin  and  copper  alloy  it  wa*  ex- 
neiisive  and  ant  to  bend  :  but  the  iron  rod  t-pppd  with  the  bronze  is  both  cheap  and  efrcctual.  An  in^eniont 
inrtriment,  called  the  shifting  cartridge,  was  lUYeuted  by  Mr  Chinalls,  and  is  described  m  the  Transactioiu 
of  the  above  soiiiety. 


MINES. 


176 


left  a  great  extent  of  forest  timber,  as  happens  at  Kongsberg  in  Norway,  at  Dannemora 
in  Sweden,  at  Felsobanya  in  Transylvania,  &c. 

The  action  of  fire  may  be  applied  to  the  piercing  of  a  gallery,  or  to  the  advancement 
of  a  horizontal  cut,  or  to  the  crumbling  down  of  a  mass  of  ore,  by  the  successive 
upraising  of  the  roof  of  a  gallery  already  pierced.  In  any  of  these  cases,  the  process 
consists  in  forming  bonfires,  the  flame  of  which  is  made  to  play  upon  the  parts  to  be 
attacked.  All  the  workmen  must  be  removed  from  the  mine,  during,  and  even  for 
some  time  after,  the  combustion.  When  the  excavations  have  become  sufficiently  cool 
to  allow  them  to  enter,  they  break  down  with  levers  and  wedges,  or  even  by  means  of 
gunpowder,  the  masses  which  have  been  rent  and  altered  by  the  fire. 

To  complete  our  account  of  the  manner  in  which  man  may  penetrate  into  the  interior 
of  the  earth,  we  must  point  out  the  form  of  the  excavations  that  he  should  make  in  it. 

In  mines,  three  principal  species  of  excavations  may  be  distinguished ;  viz.,  shafts, 
galleries,  and  the  cavities  of  greater  or  less  magnitude  which  remain  in  the  room  of  the 
old  workings. 

A  shaft  or  ptt  is  a  prismatic  or  cylindrical  hollow  space,  the  axis  of  which  is  cither 
vertical  or  much  inclined  to  the  horizon.  The  dimension  of  the  pit,  which  is  never  less 
than  32  inches  in  its  narrowest  diameter,  amounts  sometimes  to  several  yards.  Its  depth 
may  extend  to  1000  feet,  and  more.  Whenever  a  shaft  is  opened,  means  must  be  pro- 
vided to  extract  the  rubbish  which  continually  tends  to  accumulate  at  its  bottom,  as  well 
as  the  waters  which  may  percolate  down  into  it;  as  also  to  facilitate  the  descent  and 
ascent  of  the  workmen.  For  some  time  a  wheel  and  axle  erected  over  the  mouth  of  the 
opening,  which  ser\'e  to  elevate  one  or  two  buckets  of  proper  dimensions,  may  be  suffi- 
cient for  most  of  these  purposes.  But  such  a  machine  becomes  ere  long  inadequate. 
Horse-whims,  or  powerful  steam-engines,  must  then  be  had  recourse  to ;  and  efiectual 
methods  of  support  must  be  employed  to  prevent  the  sides  of  the  shaft  from  crumbling 
and  falling  down. 

A  Gallery  is  a  prismatic  space,  the  straight  or  winding  axis  of  which  does  not  usually 
deviate  much  from  the  horizontal  line.  Two  principal  species  are  distinguished ;  the 
galleries  of  elongation^  which  follow  the  direction  of  a  bed  or  a  vein ;  and  the  transverse 
galleries,  which  intersect  this  direction  under  an  angle  not  much  different  from  90**. 
The  most  ordinary  dimensions  of  galleries  are  a  yard  wide,  and  two  yards  high ;  but 
many  still  larger  may  be  seen  traversing  thick  deposites  of  ore.  There  are  few  whose 
width  is  less  than  24  inches,  and  height  less  than  40 ;  such  small  drifts  serve  merely  as 
temporary  expedients  in  workings.  Some  galleries  are  several  leagues  in  length.  We 
shall  describe  in  the  sequel  the  means  which  are  for  the  most  part  necessary  to  support 
the  roof  and  the  walls.  The  rubbish  is  removed  by  wagons  or  wheelbarrows  of 
various  kinds.     See  Jig.  946 

It  is  impossible  to  advance  the  boring  of  a  shaft  or  gallery  beyond  a  certain  rate,  because 
only  a  limited  set  of  workmen  can  be  made  to  bear  upon  it.  There  are  some  galleries 
which  have  taken  more  than  30  years  to  perforate.  The  only  expedient  for  accelerating 
the  advance  of  a  gallery,  is  to  commence,  at  several  points  of  the  line  to  be  pursued, 
portions  of  galleries  which  may  be  joined  together  on  their  completion. 

Whether  tools  or  gunpowder  be  used  in  making  the  excavations,  they  should  be  so 
applied  as  to  render  the  labor  as  easy  and  quick  as  possible,  by  disengaging  the  mass 
out  of  the  rock  at  Iwo  or  three  of  its  faces.  The  eflfect  of  gunpowder,  wedges,  or  picks, 
is  then  much  mor<  powerful.  The  greater  the  excavation,  the  more  important  is  it  to 
observe  this  rule.  With  this  intent,  the  working  is  disposed  in  the  form  of  steps, 
(gradins),  placed  like  those  of  a  stair ;  each  step  being  removed  in  successive  portions, 
the  whole  of  which,  except  the  last,  are  disengaged  on  three  sides,  at  the  instant  of  their 
being  attacked. 

The  substances  to  be  mined  occur  in  the  bosom  of  the  earth,  under  the  form  of 
alluvial  deposites,  beds,  pipe-veins,  or  masses,  threads  or  small  veins,  and  rake-veins. 

When  the  existence  of  a  deposite  of  ore  is  merely  suspected,  without  positive  proofs, 
recourse  must  be  had  to  labors  of  research,  in  order  to  ascertain  the  richness,  nature, 
and  disposition  of  a  supposed  mine.  These  are  divided  into  three  kinds  ;  open  workings, 
subterranean  workings,  and  boring  operations. 

1,  The  working  by  an  open  trench,  has  for  its  object  to  discover  the  outcropping  or 
basset  edges  of  strata  or  veins.  It  consists  in  opening  a  fosse  of  greater  or  less  width, 
which,  after  removing  the  vegetable  mould,  the  alluvial  deposites,  and  the  matters  dis- 
integrated by  the  atmosphere,  discloses  the  native  rocks,  and  enables  us  to  distinguish 
the  beds  which  are  interposed,  as  well  as  the  veins  that  traverse  them.  The  trench  ought 
always  to  be  opened  in  a  direction  perpendicular  to  the  line  of  the  supposed  deposite. 
This  mode  of  investigation  costs  little,  but  it  seldom  gives  much  insight.  It  is  chiefly 
employed  for  verifying  the  existence  of  a  supposed  bed  or  vein. 

The  subterranean  workings  afl'ord  much  more  satisfactory  knowledge.  They  are 
executed  by  diflferent  kinds  of  perforations ;  vi«.,  by  longitudinal  galleries  hollowed  out 


j 


'  *   ; 


i 


i 


i7e 


MIKES. 


of  the  mass  of  the  beds  or  veins  themselves,  in  following  their  course;  by  lransver»e 
^/Lrirpihed  at  right  angles  to  the  direction  of  the  veins;  by  xncltru>d  shafts,  whi^ 
pSe  the  slope  of  the  deposites,  and  are  excavated  in  their  mass;  or,  lastly,  by  perpen. 

''Yf  rvein  or  bed  unveils  itself  on  the  flank  of  a  mountain,  it  may  be  explored,  according 
to  the  greater  or  less  slope  of  its  inclination,  either  by  a  longitudinal  gallery  opened  in 
Us  mas'  ftom  the  outcropping  surface,  or  by  a  transverse  gallery  faUing  upon  it  m  a  cer- 
tain  po  it,  from  which  either  an  oblong  gallery  or  a  sloping  shaft  may  be  opened. 

if  our  object  be  to  reconnoitre  a  highly  inclined  stratum  or  a  vein  in  ^  level  countnr, 
we  shaU  obtain  it  with  sufficient  precision,  by  means  of  shafts,  8  or  10  yards  deep,  dug 
Tt  30  yards  distance  from  one  another ;  excavated  in  the  mass  of  ^^^^^  ^^^^^^^^^^^^^^^^^^^^ 
its  deposite.  If  the  bed  is  not  very  much  inclined,  only  4o°,  for  example  vertical  shafts 
mustTe  o^ned  in  the  direction  of  its  roof,  or  of  the  superjacent  rocky  stratum,  and 
StUeries  Xst  be  driven  from  the  points  in  which  they  meet  the  ore,  in  the  hue  of  its 

"^'When'the  rocks  which  cover  valuable  minerals  are  not  of  very  g^eat  hardne^^^as 
happens  generally  with  the  coal  formation,  with  pyritous  and  aluminous  slates,  sal  gem, 
and' ome'o'her  minerals  of  the  secondary  strata,  the  borer  is  e-Pf^Y^^jf  .'l^^^^^^ 
ascertain  their  nature.    This  mode  of  investigation  is  ^.^^'"^^i.^fj' ^^^^.J^o^^^^^ 
cases,  a  tolerably  exact  insight  into  the  riches  of  the  interior.    The  method  of  using  the 
borer  has  been  described  under  Artesian  Wells. 

OF  MINING   IN   PARTICULAK. 

The  mode  of  working  mines  is  two-fold ;  by  open  excavations,  jind  subterranean. 

WorW^s  in  the  ope'n  air  present  few  difficulties,  and  occasion  little  expense,  unless 
when  pushed  to  a  great  depth.  They  are  always  preferred  for  working  deposites  litUe 
distant' from  the  surface;  where,  in  fact,  other  "^^t^^^ds  cannot  be  resorted^^^^^ 
^.ubstance  to  be  raised  be  covered  with  incoherent  matters.  The  only  rules  to  be 
observed  are,  to  arrange  the  workings  in  terraces,  so  as  to  facilitate  the  cut  in g  down  of 
the  earth;  to  transport  the  ores  and  the  rubbish  to  their  destination  at  the  least  possible 
expense  ;  and  to  gLd  against  the  crumbling  down  of  the  sides.  With  the  latter  view 
they  ought  to  have  a  suitable  slope,  or  to  be  propped  by  timbers  whenever  they  are  not 

'^''ol^^wm-kings  are  employed  for  valuble  clays,  sands,  as  also  for  the  alluvial  soils  of 
diamCds,^oldf  and  oxyde  of  tin,  bog  iron  ores,  &c.,  limestones,  ^YP^un^s  b;;^Wmf  stones, 
roofin-  slktes,  masses  of  rock  salt  in  some  situations,  and  certain  deposites  of  ores,  partic- 
uCk  the  specular  iron  of  the  island  of  Elba;  the  masses  of  stanniferous  granite  of 
GaZ  JlteZrTand  Seyffen,  in  the  Ertzgeberge,  a  chain  of  mountains  between  Saxony 
and^  Boifemk  fhe  thick  veins  or  masses  of  black  oxyde  of  iron  of  Nordmarch  Danne- 
morar&cr^'^  Sweden;  the  mass  of  cupreous  pyrites  of  Rieraas  near  Dronthemi  in 
Norway ;  several  mines  of  iron,  copper,  and  gold  in  the  Ural  mountams  &c. 
slerranean  workings  may  be  conveniently  d  vided  into  five  classes,  viz  :- 
1.  Veins,  or  beds,  niuch  incUned  to  the  horizon,  havmg  a  thickness  of  at  least  two 

^"^'fieds  of  slight  inclination,  or  nearly  horizontal,  the  power  or  thickness  of  which 

does  not  exceed  two  yards.  

3.  Beds  of  great  thickness,  but  slightly  inclined. 

4  Veins,  of  beds  highly  inclined,  of  great  thickness. 

5  Masses  of  considerable  magnitude  in  all  their  dimensions. 

Subt^a^an  mining  requires  two  very  distinct  classes  of  workings;  the  preparatory, 

'^Tlle';:.^^^^^^^^^  in  galleries,  or  in  pits  and  gaUeries  destined.to  conduct  the 

miner  trthe  point  most  proper  for  attacking  the  deposite  of  ore,  for  tracing  it  all  round 
S^is  ooint  for  preparing  chambers  of  excavation,  and  for  concerting  neasures  with  a 
iS^wZhe  cTrcEon  of  air,  the  discharge  of  waters,  and  the  transport  of  the  extracted 

"'If'the'vein  or  bed  in  question  be  placed  in  a  mountain,  and  if  its  direction  forms  a 
very  obtuse  angle  with  the  line  of  the  slope,  the  miner  begins  by  opening  in  its  side,  at 
the  lowest  possible  level,  a  gallery  of  elongation,  which  serves  at  once  to  g've  issue  to 
the  waters,  to  explore  the  deposite  through  a  considerable  extent,  and  then  to  follow  it 
n  another  direction;  but  to  commence  the  real  mining  operations,  he  pierces  either 
shafts  or  galleries,  according  to  the  slope  of  the  deposite,  across  the  hrst  gallery. 

For  a  stratum  little  inclined  to  the  horizon,  placed  beneath  a  plain,  the  first  thmg  is 
to  Pierce  two  vertical  shafts,  which  are  usually  made  to  arrive  at  two  points  in  the  same 
Un^  of  slope,  and  a  gallery  is  driven  to  unite  them.  It  is,  m  the  first  place,  for  the  sake 
of  circulatioi  of  air  that  these  two  pits  are  sunk;  one  of  them  which  is  also  dest.n^ 
for  the  drainage  of  the  waters,  should  reach  the  lowest  point  of  the  intended  workings. 


MINES. 


177 


If  a  vein  is  intersected  by  transverse  ones,  the  shafts  are  placed  so  as  to  follow,  or,  at 
least,  to  cut  through  the  intersections.  When  the  mineral  ores  lie  m  nearly  VCTtical 
masses,  it  is  right  to  avoid,  as  far  as  possible,  sinking  pits  into  their  interior.  These 
should  rather  be  perforated  atone  side  of  their  floor,  even  at  some  considerable  distance,  to 
avoid  all  risk  of  crumbling  the  ores  into  a  heap  of  rubbish,  and  overu'helmmg  the  workmen. 
With  a  vein  of  less  than  two  vards  thick,  as  soon  as  the  preparatory  labors  have 
brou<^ht  the  miners  to  the  point  of  the  vein  from  which  the  ulterior  workings  are  to 
ramify,  whenever  a  circulation  of  air  has  been  secured,  and  an  outlet  to  the  water  and 
the  matters  mined,  the  first  object  is  to  divide  the  mass  of  ore  into  large  parallelopi- 
*  peds,  b\  means  of  oblong  galleries,  pierced  20  or  25  yards  below  one  another,  with  pits 
of  communication  opened  up,  30,  40,  or  50  yards  asunder,  which  follow  the  slope  of 
the  vein.  These  galleries  and  shafts  are  usually  of  the  same  breadth  as  the  vein,  unless 
when  it  is  very  narrow,  in  which  case  it  is  requisite  to  cut  out  a  portion  of  the  roof  or 
the  floor.  Such  workings  serve  at  once  the  purposes  of  mining,  by  aflfording  a  portion 
of  ore,  and  the  complete  investigation  of  the  nature  and  riches  of  the  vein,  a  certain 
extent  of  which  is  thus  prepared  before  removing  the  cubical  masses.  It  is  proper  to 
advance  first  of  all,  in  this  manner,  to  the  greatest  distance  from  the  central  point  which 
can  be  mined  with  economy,  and  afterwards  to  remove  the  parallelopiped  blocks,  m  work- 
ing back  to  that  point.  /.    .  •  1. 

This  latter  operation  may  be  carried  on  in  two  different  ways;  of  which  one  consists 
in  attackins;  the  ore  from  above,  and  another  from  below.  In  either  case,  the  excava- 
tions are  disposed  in  steps  similar  lo  a  stair  upon  their  upper  or  under  side.  The  first  is 
styled  a  vx)rking  in  direct  or  descending  steps  j  and  the  second  a  working  in  reverse,  or 

ascending  steps.  ^  .    ,    ,    .  ,    .  *i.     v    •      *  i 

1.  Suppose,  for  example,  that  the  post  N,;ig.  941,  included  between  the  horizontal 


gallery  a  c  and  the  shaft  a  b,  is  to  be  excavated  by  direct  steps,  a  workman  stationed 
upon  a  scaffi)ld  at  the  point  a,  which  forms  the  angle  between  the  shaft  and  the  elong- 
ated drift,  attacks  the  rock  in  front  of  him  and  beneath  his  feet.  Whenever  he  has  cut 
out  a  parallelopiped  (a  rectangular  mass),  of  from  four  to  six  yards  broad,  and  two  yards 
high,  a  second  miner  is  set  to  work  upon  a  scaffold  at  a',  two  yards  beneath  the  first, 
who,  in  like  manner,  excavates  the  rock  under  his  feet  and  before  him.  As  soon  as  the 
second  miner  has  removed  a  post  of  four  or  six  yards  in  width,  by  two  in  height,  a  third 
begins  upon  a  scaffold  at  a"  to  work  out  a  third  step.  Thus,  as  many  workmen  are 
employed  as  there  are  steps  to  be  made  between  the  two  oblong  horizontal  galleries 
which  extend  above  and  below  the  mass  to  be  excavated ;  and  since  they  all  proceed 
simultaneously,  they  continue  working  in  similar  positions,  in  floors,  over  each  other,  as 
upon  a  stair  with  very  long  wide  steps.  As  they  advance,  the  miners  construct  before 
them  wooden  floors  c  c  c  c,  for  the  purpose  of  supporting  the  rubbish  which  each 
workman  extracts  from  his  own  step.  This  floor,  which  should  be  very  solid,  serves 
also  for  wheeling  out  his  barrow  filled  with  ore.  The  round  billets  which  sup- 
port the  planks  sustain  the  roof  or  the  wall  of  the  mineral  vein  or  bed  under 
operation.  If  the  rubbish  be  very  considerable,  as  is  commonly  the  case,  the  floor 
planks  are  lost.  However  strongly  they  may  be  made,  as  they  cannot  be  repaired, 
they  sooner  or  later  give  way  under  the  enormous  pressure  of  the  rubbish  ;  and  as  all 
the  weight  is  borne  by  the  roof  of  the  oblong  gallery  underneath,  this  must  be  suffi- 
ciently timbered.  By  this  ingenious  plan,  a  great  many  miners  may  go  to  work 
toeether  upon  a  vein  without  mutual  interference ;  as  the  portions  which  they  detach 
have  always  two  faces  at  least  free,  they  are  consequently  more  easily  separable,  either 
Vol.  XL  12 


178 


MIKES. 


i 
If 


-J'! 

i  ■it 


with  gunpowder  or  with  the  pick.  Should  the  vein  be  more  than  a  yard  thick,  or  ifiu 
substance  be  very  refractor}',  two  miners  are  set  upon  each  step,  b  bb  b  indicate  the 
quadrangular  masses  that  are  cut  out  successively  downwards ;  and  1  1,  2  2,  3  3,  for- 
wards ;  the  lines  of  small  circles  are  the  sections  of  the  ends  of  the  billets  which  support 
the  floors. 
2.  To  attack  a  mass  y,Jig.  948,  a  scaffold  m  is  erected  in  one  of  its  terminal  pits  i>  p, 


MINES. 


17f 


at  the  level  of  the  ceiling  of  the  gallery  r  r',  where  it  terminates  below.  A  miner 
placed  on  this  scaffold,  cuts  off  at  the  angle  of  this  mass  a  parallelopiped  I,  from  one 
to  two  yards  high,  by  six  or  eight  long.  When  he  has  advanced  thus  far,  there  is 
placed  in  the  same  pit,  upon  another  scaffold  m'j  a  second  miner,  who  attacks  the  vein 
above  the  roof  of  the  first  cutting,  and  hews  down,  above  the  parallelopiped  1,  a  paral- 
lelopiped of  the  same  dimensions  1',  while  the  first  is  taking  out  another  2,  in  advance  of 
1.  When  the  second  miner  has  gone  forward  6  or  8  yards,  a  third  is  placed  also  in  the 
same  pit.  He  commences  the  third  step,  while  the  first  two  miners  are  pushing  forwards 
theirs,  and  so  in  succession. 

In  this  mode  of  working,  as  weU  as  in  the  preceding,  it  is  requisite  to  support  the 
rubbish  and  the  walls  of  the  vein.  For  the  first  object,  a  single  floor  nnn,  may  be  suf- 
ficient, constructed  above  the  lower  gallery,  substantial  enough  to  bear  all  the  rubbish, 
as  well  as  the  miners.  In  certain  cases,  an  arched  roof  may  be  substituted  ;  and  in 
others,  several  floors  are  laid  at  different  heights:  The  sides  of  the  vein  are  supported 
by  means  of  pieces  of  wood  fixed  between  them  perpendicularly  to  their  planes.  Some- 
times, in  the  middle  of  the  rubbish,  small  pits  are  left  at  regular  distances  apart,  through 
which  the  workmen  throw  the  ore  coarsely  picked,  down  into  the  lower  galler>'.  The 
rubbish  occasionally  forms  a  slope///,  so  high  that  miners  placed  upon  it  can  work 
conveniently.  When  the  rich  portions  are  so  abundant  as  to  leave  too  little  rubbish  to 
make  such  a  sloping  platform,  the  miners  plant  themselves  upon  moveable  floors,  which 
they  carry  forward  along  with  the  excavations. 

These  two  modes  of  working  in  the  step-form,  have  peculiar  advantages  and  disadvan- 
tages ;  and  each  is  preferred  to  the  other  according  to  circumstances. 

In  the  descending  workings,  or  in  direct  steps',  Jig.  714,  the  miner  is  placed  on  the  very 
mass  or  substance  of  the  vein ;  he  works  commodiously  before  him  ;  he  is  not  exposed 
to  the  splinters  which  may  fly  off  from  the  roof;  but  by  this  plan  he  is  obliged  to  employ 
a  great  deal  of  timber  to  sustain  the  rubbish  ;  and  the  wood  is  fixed  for  ever. 

In  the  ascending  uorkings,  or  in  reversed  steps,  Jig.  715,  the  miner  is  compelled  to  work 
in  the  re-entering  angle  formed  between  the  roof  and  the  front  wall  of  his  excavation,  a 
posture  sometimes  oppressive ;  but  the  weight  of  the  ore  conspires  with  his  efforts  to 
make  it  fall.  He  employs  less  timber  than  in  the  workings  with  direct  steps.  The  sorU 
ing  of  the  ore  is  more  diflicult  than  in  the  descending  working,  because  the  rich  ore  is 
sometimes  confounded  with  the  heap  of  rubbish  on  which  it  falls. 

When  seams  of  diluvium  or  gravel-mud  occur  on  one  of  the  sides  of  the  vein,  or  on 
both,  they  render  the  quarrying  of  the  ore  more  easy,  by  affording  the  means  of  uncover- 
ing the  mass  to  be  cut  down,  upon  an  additional  face. 

Should  the  vein  be  very  narrow,  it  is  necessary  to  remove  a  portion  of  the  sterile  rock 
which  encloses  it,  in  order  to  give  the  work  a  sufficient  width  to  enable  the  miner  to  ad- 
vance. If,  in  this  case,  the  vein  be  quite  distinct  from  the  rock,  the  labor  may  be  facili- 
tated, as  well  as  the  separation  of  the  ore,  by  disengaging  the  vein,  on  one  of  its  faces, 
through  a  certain  extent,  the  rock  being  attacked  separately.  This  operation  is  called 
stripping  the  vein.  When  it  is  thus  uncovered,  a  shot  of  gunpowder  is  sufficient  to  detach 
a  great  mass  of  it,  unmixed  with  sterile  stones. 

By  the  methods  now  described,  only  those  parallelopipeds  are  cut  out,  either  in  whole 
or  in  part,  which  present  indications  of  richness  adequate  to  yield  a  prospect  of  benefit. 
In  other  cases,  it  is  enough  to  follow  out  the  threads  of  ore  which  occur,  by  workings 
made  in  their  direction. 


The  miner,  in  searching  within  the  crust  of  the  earth  for  the  riches  which  it  concea's, 
IS  exposed  to  many  dangers.  The  rocks  amidst  which  he  digs  are  seldom  or  never  entire, 
but  are  almost  always  traversed  by  clefts  in  various  directions,  so  that  impending  frag- 
ments threaten  to  fall  and  crush  him  at  every  instant.  He  is  even  obliged  at  times  to  cut 
throus?h  rotten  friable  rocks  or  alluvial  loams.  Fresh  atmospheric  air  follows  him  with 
difficulty  in  the  narrow  channels  which  he  lays  open  before  him ;  and  the  waters  whicb 
circulate  in  the  subterranean  seams  and  fissures  filter  incessantly  into  his  excavation,  and 
tend  to  fill  it.  Let  us  now  take  a  view  of  the  means  he  employs  to  escape  from  these 
three  classes  of  dangers. 

1.  0/  the  timbering  of  excavations. — The  excavations  of  mines  are  divisible  into 
three  principal  species  ;  shaftsy  galleries,  and  chambers.  When  the  width  of  these  exca- 
vations is  inconsiderable,  as  is  commonly  the  case  with  shafts  and  galleries,  their  sides 
can  sometimes  stand  upright  of  themselves ;  but  more  frequently  they  require  to  be 
propped  or  stayed  by  billets  of  wood,  or  by  walls  built  with  bricks  or  stones ;  or  even 
by  stuffing  the  space  with  rubbish.  These  three  kinds  of  support  are  called  timbering, 
toaliing,  smd  filling  up. 

Timbering  is  most  used.  It  varies  in  form  for  the  three  species  of  excavations,  accord- 
ing to  the  solidity  of  the  walls  which  it  is  destined  to  sustain. 

In  a  gallery,  for  example,  it  may  be  sufficient  to  support  merely  the  roof,  by  means 
I  f  joists  placed  across,  bearing  at  their  two  ends  in  the  rock ;  or  the  roof  and  the  two 
walls  by  means  of  an  upper  joist  s,  fig.  949,  which  is  then  called  a  cap  or  cornice  beam, 

resting  on  two  lateral  upright  posts  or  stanchions,  a  6, 
to  which  a  slight  inclination  towards  each  other  is  given, 
so  that  they  approach  a  little  at  the  top,  and  rest  entirely 
upon  the  floor.  At  times,  only  one  of  the  walls  and  the 
roof  need  support.  This  case  is  of  frequent  occurrence 
in  pipe  veins.  Pillars  are  then  set  up  only  on  one  side, 
and  on  the  other  the  joists  rest  in  holes  of  the  rock.  It 
may  happeh  that  the  floor  of  the  gallery  shall  not  be 
sufficiently  firm  to  afford  a  sure  foundation  to  the  stand- 
ards ;  and  it  may  be  necessary  to  make  them  rest  on  a 
horizontal  piece  called  the  sole.  This  is  timbering  with 
complete  frames.  The  upright  posts  are  usually  set 
directly  on  the  sole ;  but  the  extremities  of  the  cap  or 
ceiling,  and  the  upper  ends  of  the  standards,  are  mortised 
in  such  a  manner  that  these  cannot  come  nearer,  whereby 
the  cap  shall  possess  its  whole  force  of  resistance.  In 
fi  iable  and  shivery  rocks  there  is  put  behind  these  beams,  both  upon  the  ceiling  and  the 
sides, /acing  boards,  which  are  planks  placed  horizontally,  or  spars  of  cleft  wood,  set  so 
close  togecher  as  to  leave  no  interval.  They  are  called  fascines  in  French.  In  ordinary 
ground,  the  miner  puts  up  these  planks  in  proportion  as  he  goes  forwards ;  but  in  a  loose 
soil,  such  as  sand  or  gravel,  he  must  mount  them  a  little  in  advance.  He  then  drives 
into  the  mass  behind  the  wooden  frame-work,  thick  but  sharp-pointed  planks  or  stakes, 
and  which,  in  fact,  form  the  sides  of  the  cavity,  which  he  proceeds  to  excavate.  Their 
one  extremity  is  thus  supported  by  the  earth  in  which  it  is  thrust,  and  their  other  end  by 
the  last  framing.  Whenever  the  miner  gets  sufficiently  on,  he  sustains  the  walls  by  t 
new  frame.  The  size  of  the  timber,  as  well  as  the  distance  between  the  frames  or  staiu 
chionsy  depends  on  the  degree  of  pressure  to  be  resisted. 

When  a  gallery  is  to  serve  at  once  for  several  distinct  purposes,  a  greater  height  is 
given  to  it ;  and  a  flooring  is  laid  on  it  at  a  certain  level.  If,  for  example,  a  gallery  it 
to  be  employed,  both  for  the  transport  of  the  ores  and  the  discharge  of  the  waters,  a 
floor  e  e,fig.  715,  is  constructed  above  the  bottom,  over  which  the  carriages  are  wheeled, 
and  under  which  the  waters  are  discharged. 

The  timbering  of  shafts  varies  in  form,  as  well  as  that  of  galleries,  according  to  the 
nature  and   the  locality  of  the  ground   which  they  traverse,  and  the  purposes  which 
they  are  meant  to  serve.     The  shafts  intended  to  be  stayed  with  timber  are  usually 
square  or  rectangular,  because  this  form,  in  itself  more  convenient  for  the  miner,  renders 
the  execution  of  the  timbering  more  easy.      The  wood-work  consists  generally  of 
rectangular  frames,  the  spars  of  which  are  about  eight  inches  in  diameter,  and  placed 
at  a  distance  asunder  of  from  a  yard  to  a  yard  and  a  half.     The  spars  are  never  placed 
in  contact,  except  when  the  pressure  of  the  earth  and  the  waters  is  very  great.    The 
pieces  composing  the  frames  are  commonly  united  by  a  half-check,  and  the  longer  of 
the  two  pieces  extends  often  beyond  the  angles,  to  be  rested  in  the  rock.     Whether  the 
shaft  is  vertical  or  inclined,  the  frame-work  is  always  placed  so  that  its  plane  may  be 
perpendicular  to  the  axis  of  the  pit.     It  happens  sometimes  in  inclined  shafts  that  there 
are  only  two  sides,  or  even  a  single  one,  which  needs  to  be  propped.    These  are  stayed 
by  means  of  cross  beams,  which  rest  at  their  two  ends  in  the  rock.     When  the  frames 


180 


MINES. 


MINES. 


181 


l;l 


f' 


I;  J- 


1      'f 


do  not  touch  one  another,  strong  planks  or  stakes  are  fastened  behind  them  to  sustain 
the  ground.  To  these  planks  the  frames  are  firmly  connected,  so  that  they  cannot  slid  p. 
In  this  case  the  whole  timbering  will  be  supported,  when  the  lower  frame  is  solidly  fixed, 
or  when  the  pieces  from  above  pass  by  its  angles  to  be  abutted  upon  the  ground. 

In  the  laige  rectangular  shafts,  which  serve  at  once  for  extracting  the  ores,  for  the  dis- 
charge of  the  waters,  and  the  descent  of  the  workmen,  the  spaces  destined  for  these  sev- 
eral purposes  are  in  general  separated  by  paititions,  which  also  serve  to  increase  the 
strength  of  the  timberings,  by  acting  as  buttresses  to  the  planks  in  the  long  sides  of  the 
Crame-work.  Occasionally  a  partition  separates  the  ascending  from  the  descending  bas- 
ket, to  prevent  their  jostling.— Lastly,  particular  passages  are  left  for  ventillation. 

As  it  is  desirable  that  the  wood  shall  retain  its  whole  force,  only  those  pieces  are 
squared  which  absolutely  require  it.  The  spars  of  the  frames  in  shafts  and  galleries  arc 
deprived  merely  of  their  bark,  which  by  holding  moisture,  would  accelerate  the  decompo- 
sition of  the  wood.     The  alburnum  of  oak  is  also  removed. 

Resinous  woods,  like  the  pine,  last  much  shorter  than  the  oak,  the  beech,  and  the 
cherry-tree  ;  though  the  larch  is  used  with  advantage.  The  oak  has  been  known  to  last 
upwards  of  40  years  ;  while  the  resinous  woods  decay  frequently  in  10.  The  fresher  the 
air  in  mines,  the  more  durable  is  the  timbering. 

The  marginal  ^g».  950,  951  represent  two  vertical  sections  of  a  shaft,  the  one  at  right 


angles  to  the  other,  with  the  view  of  showing  the  mode  of  sustaining  the  walls  of  the 
excavation  by  timbering.    It  is  copied  from  an  actual  mine  in  the  Hartz.    There  we  may 

observe  the  spaces  allotted  to  the  descent  of  the  miners  by 
ladders,  to  the  drainage  of  the  waters  by  pumps  p,  and  rods  /, 
and  to  the  extraction  of  the  mineral  substances  by  the  baskets 
B.  a,  by  Cyfy  ky  fc,  vavious  cross  timbers  ;  A,  c,  e,  upright  do. ; 
B,  pump  cistern  ;  v,  w,  corve-ways.  The  shafts  here  shown, 
are  excavated  in  the  line  of  the  vein  itself, — the  rock  enclosing 
it  being  seen  in  the  second  figure. 

In  a  great  many  mines  it  is  found  advantageous  to  support 
the  excavations  by  brick  or  stone  buildings,  constructed 
either  with  or  without  mortar.  These  constructions  are 
often  more  costly  than  wooden  ones,  but  they  last  much 
longer,  and  need  fewer  repairs.  They  are  employed  instead 
of  timberings,  to  support  the  walls  and  roof  of  galleries,  to 
line  the  sides  of  shafts,  and  to  bear  up  the  roofs  of  excava- 
tions. 

Sometimes  the  two  sides  of  a  gallery  are  lined  with  ver- 
tical walls,  and  its  roof  is  supported  by  an  ogee  vault,  or  an 
arch.  If  the  sides  of  the  mine  are  solid,  a  simple  arch  is 
sufficient  to  sustain  the  roof,  and  at  other  times  the  whole  surface  of  a  gallery  is  formed  of 
a  single  elliptic  vault,  the  great  axis  of  which  is  vertical ;  and  the  bottom  is  surmounted 
by  a  wooden  plank,  under  which  the  waters  run  off;  see  fig.  951.  ^ 

Walled  shafts  also  are  sometimes  constructed  in  a  circular  or  elliptic  form,  which  is 
better  adapted  to  resist  the  pressure  of  the  earth  and  waters.  Rectangular  shafts  of  all 
dimensions,  however,  are  frequently  walled.  -„.      .  ,      ,       •  v      vi.-  ». 

The  sides  of  an  excavation  may  also  be  supported  by  filhng  it  completely  with  rubbish. 
Wherever  the  sides  need  to  be  supported  for  some  time  without  the  necessity  of  passing 
along  them,  it  is  often  more  economical  to  stuff  them  up  with  rubbish,  than  to  keep  up 
their  supports.  In  the  territory  of  Liege,  for  example,  there  have  been  shafts  thus  filled 
up  for  several  centuries ;  and  which  are  found  to  be  quite  entire  when  they  are  emptied. 
The  rubbish  is  also  useful  for  forming  roads  among  steep  strata,  for  closing  air-holes,  and 
forming  canals  of  ventilation.  ,      j  • 

Figs.  952,  953,  954  represent  the  principal  kinds  of  mason-work  employed  in  the 
gaUeries  and  shafts  of  mines.  Fig.  955  exhibits  the  walling  in  of  the  cage  of  an  over- 
shot water  wheel,  as  mounted  within  a  mine.    Before  beginning  to  build,  an  exca- 


vation  large  enough  must  be  made  in  the  gallery  to  leave  a  space  three  feet  and  a  hatf 
high  for  the  workmen  to  stand  in,  after  the  brick-work  is  completed.  Between  the 
two  opposite  sides,  cross  beams  of  wood  must  be  fixed  at  certain  distances,  as  chords 
of  the  vault,  over  which  the  rock  must  be  hollowed  out  to  receive  the  arch-stones, 
and  the  centring  must  then  be  placed,  covered  with  deals  to  receive  the  voussoirsy 
beginning  at  the  flanks  and  ending  with  the  key-stone.  When  the  vault  is  finished 
lhrou<?h  a  certain  extent,  the  interval  between  the  arch  and  the  rock  must  be  rammed 
full  of  rubbish,  leaving  passages,  if  necessary,  through  it  and  the  arch,  for  currents 

of  water.  ,  /.  a  * 

In  walling  galleries,  attention  must  be  paid  to  the  direction  of  the  pressure,  and  !• 
build  vertically  or  with  a  slope  accordingly.  Should  the  pressure  be  equal  in  all 
directions,  a  closed  vault,  like  fig.  952,  should  be  formed.  For  walls  not  far  from  the 
vertical,  salient  or  buttressed  arches  are  employed,  as  shown  m  fig.  9o3,  called  m 
German  uberspringende  bogen;  for  other  cases,  twin-arches  are  preferred,  with  an  upright 

Wall  between. 

Fig.  954  is  a  transverse  section  of  a  walled  drain-gallery,  from  the  grand  gallery  of 
the  Hartz  ;  see  also /ig.  955.     a  is  the  rock,  which  needs  to  be  supported  only  at  the  sides 


and  top ;  6,  the  masonwork,  a  curve  formed  of  the  three  circular  arcs  upon  one  level ; 
c,  the  floor  for  the  water-course.  Fig.  952  is  a  cross  section  of  a  walled  gallery,  as  at 
Schneeberg,  Rothenburg,  Idria,  &c. ;  d,  is  the  rock,  which  is  not  solid  either  at  the  flanks, 
roof,  or  floor ;  €,  the  elliptic  masonwork  ;  /,  the  wooden  floor  for  the  wagons,  which  is 
sometimes,  however,  arched  in  brick  to  allow  of  a  water-course  beneath  it. 

Fig.  963  shows  two  vertical  projections  of  a  portion  of  a  walled  shaft  with  buttresses, 
as  built  at  the  mine  Vater  Mrahaniy  near  Marienberg.  j  is  a  section  in  the  direction  of 
the  vein  g  h,  to  show  the  roof  of  the  shaft,  i,  a  section  exhibiting  the  slope  of  the  vein 
g  hy  into  which  the  shaft  is  sunk  ;  m  is  the  wall  of  the  vein  ;  fe  is  the  roof  of  the  same 
vein ;  n,  buttresses  resting  upon  the  flanks  of  the  shaft ;  g,  great  arcs  on  which  the  but- 
tresses bear ;  y,  vertical  masonwork  ;  r,  a  wall  which  divides  the  shaft  into  two  compart- 
ments, of  which  the  larger,  j5,  is  that  for  extracting  the  ore,  and  the  smaller  for  the  drain- 
ing and  descent  of  the  miners. 

.  Fig.  955,  c  D  is  the  shaft  in  which  the  vertical  crank-rods  c  g,  c  rf,  move  up  and 
down.  F,  is  a  double  hydraulic  wheel,  which  can  be  stopped  at  pleasure  by  a  brake 
mounted  upon  the  machine  of  extraction,  g,  is  the  drum  of  the  gig  or  whim  for  raising 
the  corves  or  tubs  (tonnes) ;  h,  is  the  level  of  the  ground,  with  the  carpentry  which  sup- 
ports the  whim  and  its  roof,  fc,  is  the  key-stone  of  the  ogee  arch  which  covers  the 
water-wheel ;  a,  is  the  opening  or  window,  traversed  by  the  extremity  of  the  driving 
shaft,  upon  each  side  of  the  water-wheel,  through  which  a  workman  may  enter  to  adjust 
or  repair  it }  c  6,  line  of  conduits  for  the  streams  of  water  which  fall  upon  the  hydraulic 


1    !  ift  u 


182 


MINES. 


wheel ;  f,  g,  double  crank  with  rods,  whose  motion  is  taken  off  the  left  side  of  the  wheel ; 
€,  d,  the  same  upon  the  right  side.    The  distance  from  h  to  f  is  about  22  yards. 

Figs.  956,  957  present  two  vertical  sections  of  the  shaft  of  a  mine  walled,  like  the  roof 
of  a  cavern,  communicating  with  the  galleries  of  the  roof  and  the  wall  of  the  vein,  and 
weU  arranged  for  both  the  extraction  of  the  ore,  and  the  descent  of  the  miners.  The 
vertical  partition  of  the  shaft  for  separating  the  passage  for  the  corves  or  tubs  from  the 
ladders  is  omitted  in  the  figure,  for  the  sake  of  clearness. 

In^g.  956,  A,  B  are  the  side  walls  supported  upon  the  buttresses  c  and  d  ;  in  fig.  957, 
E  is  the  masonry  of  the  wall,  borne  upon  the  arch  f  at  the  entrance  to  a  gallery ;  *he 
continuation  being  at  g,  which  is  sustained  by  a  similar  arch  built  lower. 

L,  is  the  vault  arch  of  the  roof,  supported  upon  another  vault  m,  which  presents  a  double 
curvature,  at  the  entrance  of  a  gallery ;  at  h  is  the  continuation  of  the  arch  or  vault  L, 
which  underneath  is  supported  in  like  manner  at  the  entrance  of  a  lower  gallery. 

a  6,  c  d,fig.  956,  are  small  upright  guide-bars  or  rods  for  one  of  the  corves,  or  kibbles. 

*/i  S  ''J  ^re  similar  guide-bars  for  the  other  corf. 

%  i,  are  cross-bars  of  wood,  which  support  the  stays  of  the  ladders  of  descent. 

k  k,  are  also  cross-bars  by  which  the  guide-rods  are  secured. 

t,  a  corf,  or  extraction  kibble,  furnished  with  friction  rollers;  the  other  corf  is  supposed 
to  be  drawn  up  to  a  higher  level,  in  the  other  vertical  passage. 

956 


958 


959 


Figs.  958,  959  represent  in  a  vertical  section  the  mode  of  timbering  the  galleries  of  the 
silver  and  lead  mines  at  Andreasberg  in  the  Hartz.  Fig.  968  shows  the  plan  viewed 
from  above.  Upon  the  roof  of  the  timbering,  the  workman  throws  the  waste  rubbish, 
and  in  the  empty  space  below,  which  is  shaded  black,  he  transports  in  his  wagons  or 
wheelbarrows  the  ores  towards  the  mouth  of  the  mine.  Fig.  959  is  the  cross  section  of 
the  gallery.  In  the  two  figures,  a  represents  the  rock,  and  b  the  timbering ;  round  which 
there  is  a  garniture  of  small  spars  or  lathes  for  the  purpose  of  drainage  and  ventilation 
with  the  view  of  promoting  the  durability  of  the  wood-work, 


MINES. 


183 


The  working  of  minerals  by  the  mass  is  well  exemplified  a  few  leagues  to  the  north  of 
Siegen,  near  the  village  of  Miisen,  in  a  mine  of  iron  and  other  metals,  called  Stahlberg, 
which  forms  the  main  wealth  of  the  country.  The  plan  of  working  is  termed  the  excava^ 
tion  of  a  direct  or  transverse  mass.  It  shows  in  its  upper  part  the  danger  of  bad  mining, 
and  in  its  inferior  portion,  the  regular  workings,  by  whose  means  art  has  eventually  pre- 
vented the  destruction  of  a  precious  mineral  deposite. 

Fig.  960  is  a  vertical  section  of  the  bed  of  ore,  which  is  a  direct  mass  of  spathose 


iron,  contained  in  transition  rock  (graywacke).  a,  a,  a,  are  pillars  of  the  sparry  ore, 
reserved  to  support  the  successive  stages  or  floors,  which  are  numbered  1,  2,  3,  &.c. ; 
b  fe,  b,  are  excavations  worked  in  the  ore ;  which  exhibit  at  the  present  day  several 
floors  of  arches,  of  greater  or  less  magnitude,  according  to  the  localities.  It  may  be 
remarked,  that  where  the  metallic  deposite  forms  one  entire  mass,  rich  in  spathose  iron 
ore  of  good  quality,  there  is  generally  given  to  the  vaults  a  height  of  three  fathoms ; 
leaving  a  thickness  over  the  roof  of  two  fathoms,  on  account  of  the  numerous  fissures 
which'iiervade  the  mass.  But  where  this  mass  is  divided  into  three  principal  branches, 
the  roof  of  the  vaults  has  only  a  fathom  and  a  half  of  thickness,  while  the  excavation  is 
three  fathoms  and  a  half  high.  In  the  actual  state  of  the  workings,  it  may  be  estimated 
that  from  all  this  direct  mass,  there  is  obtained  no  more  out  of  every  floor  than  one 
third  of  the  mineral.  Two  thirds  remain  as  labors  of  resert^e,  which  may  be  resumed 
at  some  future  day,  in  consequence  of  the  regularity  and  the  continuation  of  the  subter- 
ranean workings,  e  is  a  shaft  for  extraction,  communicating  below  with  the  gallery  of 
efflux  k;  his  an  upper  gallery  of  drainage,  which  runs  in  different  directions  (one  only 
bein"  visible  in  this  section)  over  a  length  of  400  fathoms.  The  lower  gallen'  k  runs 
646  fathoms  in  a  straight  line.  The  mine  of  Stahlberg  has  furnished  annually  on  an 
average  since  1760  about  25,000  cubic  feet  (French)  of  an  excellent  spathose  ore  of  iron. 
m  m,  represents  the  mass  of  sparry  iron.  •     r       • 

Figs.  961,  962,  963  represent  the  cross  system  of  mining,  which  consists  in  torming 
'  '  -  galleries  through  a  mineral  deposite,  from  its  wall  or  floor 
towards  its  roof,  and  not,  as  usual,  in  the  direction  of  its 
length.  This  mode  was  contrived  towards  the  middle  of 
the"  18th  century,  for  working  the  very  thick  veins  of  the 
Schemnitz  mine' in  Hungary,  and  it  is  now  employed  with 
advantage  in  many  places,  particularly  at  Idria  in  Carniola. 
In  the  two  sections  figs.  961,  963,  as  well  as  in  the  ground 
plan^g.  962,  the  wallis  denoted  by  m  m,  and  the  roof  by  /  /. 

_^^^,,==^__ A  first  gallery  of  prolongation  e  f,  fig.  963,  being  formed  to 

the  wall,  transverse  cuts,  a  a,  are  next  established  at  right  angles  to  this  galler>',  so  that 
between  every-  two  there  may  be  room  enough  to  place  three  others,  6,  c,  b,fig.  962.  From 
each  of  the  cuts  a,  ore  is  procured  by  advancing  with  the  help  of  timbering,  till  the 
roof  t  be  reached.  When  this  is  done,  these  first  cuts  a,  are  filled  up  with  rubbish,  laid 
upon  pieces  of  timber  with  which  the  ground  is  covered,  so  that  if  eventually  it  should 
be  wished  to  mine  underneath,  no  downfall  of  detritus  is  to  be  feared.  These  heaps 
of  rubbish  rise  only  to  within  a  few  inches  of  the  top  of  the  cuts  a,  in  order  that  the 
working  of  the  upper  story  may  be  easier,  Ihe  bed  of  ore  being  there  already  laid  open 
upon  its  lower  face. 

In  proportion  as  the  cuts  a,  oi  the  first  story  e  f,  are  thus  filled  up,  the  greater  part 
of  the  timbering  is  withdr\wn,  and  made  use  of  elsewhere.  The  intermediate  cuU 
b,  c,  6,  are  next  mined  in  like  manner,  either  beginning  with  the  cuts  c,  or  the  cuts  6,  ac- 
cording to  the  localities.  From  fig.  962  it  appears  that  the  working  may  be  so  ar- 
tanged,  that  in  case  of  necessity,  there  may  be  always  between  two  cuts  m  activity  the 


961  ^ 


I 


f 


lis 

7     '    . 


184 


MINES. 


*stanc€  of  three  cuts,  either  not  made,  or  filled  up  with  rubbish.  Hence,  alJ  the  portion 
of  the  bed  of  ore  may  be  removed,  which  corresponds  to  a  first  story  e  Tfjig.  963,  and  thia 
portion  is  replaced  by  rubbish. 


962 


The  exploration  of  the  upper  stories  e'  f',  e2  f2,  e3  f3,  is  now  prepared  in  a  similar 
manner;  with  which  view  shafts  h  hi,  k  fc3,  are  formed  from  below  upwards  in  the  wall 
m  of  the  deposite,  and  from  these  shafts  oblong  galleries  proceed,  established  successively 
on  a  level  with  the  stories  thus  raised  over  one  another.  See  Jig,  963.  The  following 
objects  may  be  specified  in  the  figures  : — 


a  a,  the  first  cuts  filled  up  with  rubbish,  upon  the  tirst  story  e  Tyjig.  962. 
b  b,  other  cuts  subsequently  filled  up,  upon  the  same  story. 
e,  the  cut  actually  working. 

d,  the  front  of  the  cut,  or  place  of  actual  excavation  of  the  mineral  deposite. 

e,  masses  of  the  barren  rock,  reserved  in  the  cutting,  as  pillars  of  safety. 

/,  galleries,  by  means  of  which  the  workmen  may  turn  round  the  mass  e,  in  order  to 
form,  in  the  roof  t,  an  excavation  in  the  direction  of  the  deposite. 
g,  rubbish  behind  the  mass  e. 

k  fc,  two  shafts  leading  from  the  first  story  e  f,  to  the  upper  stories  of  the  workint's  as 
already  stated.  ^  ' 

wi,  the  wall,  and  /  the  roof  of  the  mineral  bed. 

In  the  second  story  e'  f',  the  gallery  of  prolongation  r',  figs.  961  and  963  is  not  entirely 
perforated ;  but  it  is  further  advanced  than  that  of  the  third  story,  which,  in  its  turn  ia 
more  than  the  gallery  of  the  fourth.  * 

From  this  arrangement  there  is  produced  upon  j^g.  963  the  general  aspect  of  a  workine 
by  reversed  steps.  * 

Whenever  the  workings  of  the  cuts  c  in  the  first  story  are  finished,  those  of  the  second 

a'  a',  may  be  begun  in  the  second  ;  and  thus  by  mounting  from  story  to  story  the  whole 

deposite  of  ore  may  be  taken  out  and  replaced  with  rubbish.     One  great  advanta'^e  of  this 

method  is,  that  nothing  is  lost ;  but  it  is  not  the  only  one.     The  facilities  offered  bv  the 

system  of  cross  vwrkings  for  disposing  of  the  rubbish,  most  frequently  a  nuisance  to  the 

miner,  and  expensive  to  get  rid  of,  the  solidity  Avhich  it  procures  by  the  bankin"  up  the 

consequent  economy  of  timbering,  and  saving  of  expense  in  the  excavation  of  the  rock 

reckoning  from  the  second  story,  are  so  many  important  circumstances  which  recommend 

this  mode  of  mining.     Sometimes,  indeed,  rubbish  may  be  wanted  to  fill  up,  but  this  may 

always  be  procured  by  a  few  accessory  perforations ;  it  being  easy  to  establish  in  the 

vicmity  ol  the  workings  a  vast  excavation  in  the  form  of  a  vault,  or  kind  of  subterraneous 

quarry,  which  may  be  allowed  to  fall  in  with  proper  precautions,  and  where  rubbish  will 

thus  accumulate  m  a  short  time,  at  little  cosL 

Fig.  964  represents  a  section  of  the  celebrated  lead  mines  of  Bleyberg  in  Carinthia.  not 
far  from  Villach.  ^       =•  i    "• 

6,  c,  is  the  ridge  of  the  mountains  of  compact  limestone,  in  whose  bosom  the  wonanes 
arc  carried  on.  ° 

t  is  the  metalliferous  valley,  running  from  east  to  west,  between  the  two  pareUel 


MINES. 


186 


valleys  of  the  Gail  and  the  Drave,  but  at  a  level  considerably  above  the  waters  of  these 

"7Tis  the  direction  of  a  great  many  vertical  beds  of  metalliferous  limestone, 
■of  considering  the  direction  and  dip  of  the  marly  schist,  and  ""-^'"'"f'™"'  '^^^J'",^ 

m  the  space  lo,  to,  to   me  wesi  oi 

Qg.  ^^^^  '  the  line  1,  »,  it  would  appear  that 

.>^^^^>^  ^  ^j.p^j  portion  of  this  system  of 

mountains  has  suffered  a  slip  between 
1,  s,  and  a  parallel  one  towards  the 
east;  whereby,  probably,  that  ver- 
tical position  of  the  strata  has  been 
produced,  which  exists  through  a 
considerable  extent.  The  metallifer- 
ous limestone  is  covered  to  a  certain 
thickness  with  a  marly  schist,  and 
other  more  recent  rocks.  It  is  in 
this  schist  that  the  fine  marble  known 
under  the  name  of  the  luviachello  of 
Bleyberg  is  quarried. 

The  -alena  occurs  in  the  bosom  of  this  rock  in  flattened  masses,  or  Wocks  of  a  con- 
siderabfe  vXme,  which  are  not  separated  from  the  rest  of  the  calcareous  beds  by  any 
seam       It  is  accompanied  by  zinc  ore  icalamm),  especially  in  the  upper  parts  of  the 

"^Tver^l  of  the  workable  masses  are  indicated  by  r,  r3;  each  presents  itself  as  a 
solid  analoc^ous  to  a  very  elongated  ellipse,  whose  axis  dips,  not  according  to  the  mc  ina- 
S>n  of  theCrounding  rock,  but  to  an  oblique  or  intermediate  line  be^wf  en  this  inclina- 
tion,  and  the  direction  of  the  beds  of  limestone ;  as  shown  by  r  w  r  u.  E%  er>  th  ng 
Sates  the  contemporaneous  formation  of  the  limestone,  and  the  lying  beds  of  the 

^' Thraccidents  or  faults  called  kluft  (rent)  at  Bleyberg  are  visible  on  the  surface  of  the 
ground.  Experienced  miners  have  remarked  that  the  rich  masses  occur  more  frequently 
in  the  direction  of  these  accidents  than  elsewhere.  ,      ^   ^  ^  .  .  „.  jiffv. 

It  is  in  general  by  galleries  cut  horizontally  in  the  bcnly  of  the  mountain,  and  at  differ- 
ent  levels  »,  g,  ^U  that  the  miner  advances  towards  the  masses  of  ore  r,  rz.  Many  of 
these  ganeries^kr'e  500  fathoms  long  before  they  reach  ^  ^^'^kable  mass  TJie  sev^^^ 
galleries  are  placed  in  communication  by  a  few  shafts,  such  as  <;  but  few  oi  these  are 

sunk  deeper  than  the  level  of  the  valley  c.  ^^         ,  n  i  *     .i.^ 

The  tLl  length  of  the  mines  of  Bleyberg  is  about  10,000  yards,  parallel  to  the 

vallev  6  .  in  which  space  there  are  500  concessions  granted  by  the  govern  men   to  various 

individuals  or  joint  stock  societies,  either  by  themselves  or  associated  with  the  govern- 

""  The  metalliferous  valley  contains  5000  inhabitants,  all  deriving  subsistence  from  the 
mines ;  300  of  whom  are  occupied  in  the  government  works.  t^„,.v„„,  ncw«w; 

Each  concession  has  a  number  and  a  name  ;  as  Antoni,  Christoph,  Matthseus,  Oswaldi, 

^'  F«g.  ^t'is  a  section  in  the  quicksilver  mine  of  Idria.  1.  is  the  gray  limestone ;  2.  is 
a  blackish  slate ;  5.  is  a  grayish  slate.  Immediately  above  these  transition  rocks  lies  the 
bed  containing  the  ores  called  corallenerz,  which  consist  of  an  intimate  mixture  of  sul- 
phuret  of  mercury  and  argillaceous  Umestone  ;  in  which  four  men  can  cut  out,  m  a  month, 
2J  toises  cube  of  rock. 


965 


Fig.  966  represents  a  section 
of  part  of  the  copper  mine  of 
Mansfeldt ;  containing  the  cellular 
limestone,  called  rauchwacke,  al- 
ways with  the  compact  marl-Iimo- 
stone  called  zechstein ;  the  cupre- 
ous schist,  or  kupferschiefer;  the 
wall  of  grayish-white  sandstone, 
called  the  weisse  liesende ;  and  the 
wall  of  red  sandstone,  or  the 
rolhelie  gende.  The  thin  dotted 
stratum  at  top  is  vegetable  mould ; 
the  laree  dotted  portion  to  the 
right  of  the  figure  is  oolite ;  the 

vein  at  its  side  is  sand ;  next  is  rauchwacke ;  and  lastly,  the  main  body  of  fetid  limestone^ 

or  stinkstein. 


II 


186 


MINES. 


Fig.  967  represents  one  of  the  Mansfeldt  copper  schist  mines  in  the  diitrict  called 
Burgoerner,  or  Preusshoheit. 

1.  Vegetable  mould,  with  silicious  gravel. 

2.  Ferruginous  clay  or  loam. 

3.  Sand,  with  fragments  of  quartz. 

4.  Red  clay,  a  bed  of  variable  thickness  as  well  as  the  lower  strata,  according  as  the 
cupreous  schist  is  nearer  or  farther  from  the  surface. 

5.  Ooolite  iroogenstein). 

6.  Newer  variegated  sandstone  (hunter  sandstcin), 

7.  Newer  gypsum ;  below  which,  there  is 

8.  A  bluish  marly  clay. 

9.  Slinkstone,  or  lucullite. 

10.  Friable  grayish  marl. 

11.  Older  gypsum,  a  rock  totally  wanting  in  the  other  district?  of  the  mines  of  Kothen- 
berg ;  but  abounding  in  Saxon  Mansfeldt,  where  it  includes  vast  caverns  known  among 
the  miners  by  the  name  of  schlotten,  as  indicated  in  the  figure. 

12.  The  calcareous  rock  called  zechstein.  The  lower  part  of  this  stratum  shows 
symptoms  of  the  cupriferous  schist  that  lies  underneath.  It  presents  three  thin  bands, 
differently  modified,  which  the  miner  distinguishes  as  he  descends  by  the  names  of  Ihe 
Sterile  or  rotten  {fault)  rock;  the  roof  (dachklotz) ;  and  the  main  rock  {oberberg.) 


yo8 


13.  Is  a  bed  of  cupriferous  schist  (kupferschiefer),  also  called  the  bitumino-marly 
schist,  in  which  may  be  noted,  in  going  down,  but  not  marked  in  the  figure  : — 

a,  the  lochberg,  a  seam  4  inches  thick. 
by  the  kammschale,  |  of  an  inch  thick. 

c,  the  kop/schakf  one  inch  thick. 

These  seams  are  not  worth  smelting ;  the  following,  however,  are  :— 

d,  the  schiefer  kopf,  the  main  copper  schist,  2  inches  thick. 

e,  a  layer  called  locherij  one  inch  thick. 

14.  The  wall  of  sandstone,  resting  upon  a  porphyry. 

Fig.  968  is  a  section  of  the  mines  of  Kiegelsdorf  in  Hessia,  presenting — 

1.  Vegetable  mould. 

2.  Limestone  distinctly  stratified,  frequently  of  a  yellowish  color,  called  lagerha/ter 
kalkstein. 

3.  Clay,  sometimes  red,  sometimes  blue,  sometimes  a  mixture  of  red,  blue,  and 

yellow. 

4.  The  cellular  limestone  (rauhkalk).  This  rock  dififers  both  in  nature  and  position 
from  the  rock  of  the  same  name  at  Mansfeldt. 

5.  Clay,  usually  red,  containing  veins  of  white  gypsum,  and  fine  crystals  of  sele- 
nite. 

6.  Massive  gypsum  of  recent  formation. 

7.  Fetid  limestone,  compact  and  blackish  gray,  or  cellular  and  yellowish  gray. 

8.  Pulverulent  limestone,  with  solid  fragments  interspersed. 

9.  Compact  marl-limestone,  or  zechstein,  which  changes  from  a  brownish  color  above 
to  a  blackish  schist  below,  as  it  comes  nearer  the  cupreous  schist,  which  seems  to  form  a 
part  of  it. 

10.  Cupreous  schist  (kupferscniefer),  of  which  the  bottom  portion,  from  4  to  6  inches 
thick,  is  that  selected  for  metallurgic  operations.  Beneath  it,  is  found  the  usual  wall  or 
bed  of  sandstone.  A  vein  of  cobalt  ore  «,  which  is  rich  only  in  the  grayish- white  sand- 
stone {weisse  liegende),  traverses  and  deranges  all  the  beds  wherever  it  comes. 

0/  working  mines  by  fire. — The  celebrated  mine  worked  since  the  tenth  century  in 
Uie  mountain  called  Rammelsberg,  in  the  Hartz,  to  the  south  of  Goslar,  presents  a  strar 


MINES. 


187 


tificd  mass  of  ores,  among  the  beds  of  the  rock  which  constitute  that  mountam.  The 
mineral  deposite  is  situated  in  the  earth,  like  an  enormous  mverted  wedge,  so  ^  *  „i« 
thickness  (power),  inconsiderable  near  the  surface  of  the  ground,  mcreases  as  it  descends. 
At  about  100  yards  from  its  outcrop,  reckoning  in  the  direction  of  the  slope  oi  me  ae- 
posite,  it  is  divided  into  two  portions  or  branches,  which  are  separated  Irom  eacn  omer, 
throughout  the  whole  known  depth,  by  a  mass  of  very  hard  clay  slate,  which  passes  into 
flinty  slate.  The  substances  composing  the  workable  mass  are  copper  and  iron  pjriies 
with  sulphuret  of  lead  (galena),  accompanied  by  quartz,  carbonate  of  lane,  compact  sul- 
phate of  baryta,  and  sometimes  gray  copper  ore,  sulphuret  of  zinc,  and  arsenical  pyriie. 
The  ores  of  lead  and  copper  contain  silver  and  gold,  but  in  small  proportion,  particularly 

as  to  the  last.  .  .  _  ,    j-  -j  j  „.„«.,« 

A  mine  so  ancient  as  that  of  Rammelsberg,  and  which  was  formerly  divided  among 
several  adventurous  companies,  cannot  fail  to  present  a  great  many  shafts  and  excava- 
tions ;  but  out  of  the  15  pits,  only  two  are  employed  for  the  present  workings  ;  namely, 
those  marked  a  b  and  e  f,  in  fig.  969,  by  which  the  whole  extraction  and  drainage  are 


executed.     The  general  system  of  exploitation  by  fire,  as  practised  in  this  mine,  consists 
of  the  following  operations  : — 

1    An  advance  is  made  towards  the  deposites  of  ore,  successively  at  diflferent  levels, 
by  transverse  galleries  which  proceed  from  the  shaft  of  extraction,  and  terminate  at  the 

wall  of  the  stratiform  mass.  ...  /•   i.  u 

2.  There  is  formed  in  the  level  to  be  worked,  large  vaults  in  the  heart  of  the  ore,  by 

means  of  fire,  as  we  shall  presently  describe.  ^        j  r        4»,        kk-.i. 

3.  The  floor  of  these  vaults  is  raised  up  by  means  of  terraces  formed  from  the  rubbisn, 
in  proportion  as  the  roof  is  scooped  out.  ,      ..       j 

4.  The  ores  detached  by  the  fire  from  their  bed,  are  picked  and  gathered ;  sometime* 

the  larger  blocks  are  blasted  with  gunpowder.  ^     ^      ,.  «.    r      *      .•  a 

5.  Lastly,  the  ores  thus  obtained  are  wheeled  towards  the  shaft  of  extraction,  and 

turned  out  to  the  day.  ,  .  j  •    ^i.  *    •        i  .  .     ^«„ 

Let  us  now  see  how  the  excavation  by  fire  is  practised  ;  and  m  that  view,  let  us  con- 
sider the  state  of  the  workings  in  the  mines  of  Rammelsberg  in  1809.  We  may  remark 
in  fie  969  the  re^^ulariiy  of  the  vaults  previously  scooped  out  above  the  level  b  c,  and 
the  other  vaults  which  are  in  full  activity  of  operation.  It  is,  therefore,  towards  the 
lower  levels  that  the  new  workings  must  be  directed.  For  this  purpose,  the  transverse 
gallery  being  alreadv  completed,  there  is  prepared  on  the  first  of  these  floors  a  vault  of 
exploitation  at  6,  which  eventually  is  to  become  similar  to  those  of  the  superior  levels. 
At  the  same  time,  there  is  commenced  at  the  starting  point  below  it,  reached  by  a  smaU 
well  dug  in  the  line  of  the  mineral  deposite,  a  transverse  gallery  m  the  rock,  by  means 
of  biastino'  with  gunpowder.  The  rock  is  also  attacked  at  the  starting-point  by  a  similar 
cut,  which  advances  to  meet  the  first  perforation.  In  this  way,  whenever  the  vaults  of 
the  level  c  are  exhausted  of  ore  and  terraced  up  with  rubbish,  those  of  the  level  beneath 

it  will  be  in  full  activity.  .     . 

Others  will  then  be  prepared  at  a  lower  level;  and  the  exploitation  may  afterwards  t>e 
driven  below  this  level  by  pursuing  the  same  plan,  by  which  the  actual  depth  of  excava- 
tion has  been  sained. 

In  workings  by  fire  we  must  distinguish,  1.  The  case  where  it  is  neecessan'  to  open 
a  vault  immediately  from  the  floor ;  2.  The  case  where  the  vault  having  already  a 
certain  elevation,  it  is  necessary  to  heighten  its  roof  In  the  former  case,  the  wall  or  floor 
of  the  mineral  deposite  is  first  penetrated  by  blasting  with  gunpowder.  As  soon  as  th'S 
penetration  is  eflected  over  a  certain  length,  parallel  to  the  direction  of  the  future 
vault,  as  happens  at  6,  there  is  arranged  on  the  bottom  a  horizontal  layer  of  billets  of 
firwood,  over  which  other  billets  are  piled  in  nearly  a  vertical  position,  which  rest  upon 
the  ore,  so  that  the  flame  in  its  expansion  comes  to  play  against  the  mineral  mass  to  be 


[I- a 


.r^  i- 


•-"I  I' 


188 


MINES. 


detached.  Wlien  after  some  similar  operations,  the  flame  of  the  pile  can  no  longer 
reach  the  ore  of  the  roof  on  account  of  its  height,  a  small  terrace  of  rubbish  must  be 
raised  on  the  floor  of  the  deposite  ;  and  over  this  terrace,  a  new  pile  of  fagots  is  to  be 
heaped  up  as  above  described.  The  ancient  miners  committed  the  fault  of  constantly 
placing  such  terraces  close  to  the  roof,  and  consequently  arranging  the  fagots  against 
this  portion  of  the  ore,  so  that  the  flame  circulated  from  the  roof  down  to  the  floor. 
The  result  of  such  procedure  was  the  weakening  of  the  roof,  and  the  loss  of  much  of  the 
ore  which  could  not  be  extracted  from  so  unstable  a  fabric ;  and  besides,  much  more 
wood  was  burned  than  at  the  present  day,  because  the  action  of  the  flame  was  dissipated 
in  part  against  the  whole  mass  of  the  roof,  instead  of  being  concentred  on  the  portion  of 
the  ore  which  it  was  desired  to  dislodge.  Now,  the  flame  is  usually  made  to  circulate 
from  the  floor  to  the  roof,  in  commencing  a  new  vault. 

When  the  vault  has  already  a  certain  height,  care  is  always  taken  that  between  the 
roof  of  the  vault  and  the  rubbish  on  which  the  pile  is  arranged,  no  more  than  two  yards 
of  space  should  intervene,  in  order  that  the  flame  may  embrace  equally  the  whole  con- 
cavity of  the  vault,  and  produce  a  uniform  effect  on  all  its  parts.  Here,  the  pile  is 
formed  of  horizontal  beds,  disposed  crosswise  above  one  another,  and  presents  four  free 
vertical  faces,  whence  it  has  been  called  a  chest  by  the  miners. 

It  is  usually  on  Saturday  that  the  fire  is  applied  to  all  the  piles  of  fagots  distributed 
through  the  course  of  the  week.  Those  in  the  upper  floors  of  exploitation  are  first 
burned,  in  order  that  the  inferior  piles  may  not  obstruct,  by  their  vitiated  air,  the  com- 
bustion of  the  former.  Thus,  at  4  o'clock  in  the  morning,  the  fires  are  kindled  in  the 
upper  ranges  ;  from  pile  to  pile,  the  fireman  and  his  assistant  descend  towards  the  lower 
floors,  which  occupies  them  till  3  o'clock  in  the  afternoon.  Vainly  should  we  endeavor 
to  describe  the  majestic  and  terrific  spectacle  which  the  fire  presents,  as  it  unfolds  its 
winjjs  under  its  metallic  vaults,  soon  filled  with  vast  volumes  of  smoke  and  flame.  Let  us 
mark  the  useful  effiect  which  it  produces. 

When  the  flame  has  beat  for  a  few  instants  on  the  beds  of  ore,  a  strong  odor  of 
sulphur,  and  sometimes  of  arsenic  is  perceived ;  and  soon  thereafter  loud  detonations 
are  heard  in  the  vaults.  Suddenly  the  flame  is  seen  to  assume  a  blue  color,  or  even  a 
white  ;  and  at  this  period,  after  a  slight  explosion,  flakes  of  the  ore,  of  greater  or  less 
magnitude,  usually  fall  down  on  the  fire,  but  the  chief  portion  of  the  heated  mineral 
still  remains  fixed  to  the  vault.  The  ores  pass  now  into  a  shattered  and  divided 
condition,  which  allows  them  afterwards  to  be  detached  by  long  forks  of  iron.  In  this 
manner  the  fire,  volatilizing  entirely  some  principles,  such  as  sulphur,  zinc,  arsenic,  and 
water,  changing  the  aggregation  of  the  constituent  parts  of  the  ore,  and  causing  fissures 
by  their  unequal  expansibilities,  facilitates  the  excavation  of  such  materials  as  resist  by 
their  tenacity  the  action  of  gunpowder. 

The  combustion  goes  on  without  any  person  entering  the  mine  from  Saturday  even- 
ing till  Monday  morning,  on  which  day,  the  fireman  and  his  assistants  proceed  to 
extinguish  the  remains  of  the  bonfires.  On  Monday  also  some  piles  are  constructed  in 
the  parts  where  the  effect  of  the  former  ones  has  been  incomplete ;  and  they  are  kindled 
after  the  workmen  have  quitted,  the  mine.  On  Tuesday  all  hands  are  employed  in 
detaching  the  ores,  in  sorting  them,  taking  them  out,  and  preparing  new  piles  against  the 
next  Saturday. 

The  labor  of  a  week  consists  for  every  man  of  five  posts  during  the  day,  each  of  8 
hours,  and  of  one  post  of  four  hours  for  Saturday.  Moreover,  an  extra  allowance  is  made 
to  such  workmen  as  employ  themselves  some  posts  during  the  night. 

The  labor  of  one  compartment  or  atelier  of  the  mine  consists  therefore  in  arranging 
the  fagots,  in  detaching  the  ore  which  has  already  experienced  the  action  of  the  fire,  i» 
breaking  the  blocks  obtained,  in  separating  the  ore  from  the  debris  of  the  pile,  and, 
whenever  it  may  be  practicable  or  useful,  in  boring  holes  for  blasting  with  gunpowder. 
The  heat  is  so  great  in  this  kind  of  mine,  that  the  men  are  obliged  to  work  in  it  without 
dothing. 

We  have  already  remarked,  that  besides  the  working  by  fire,  which  is  chiefly  used  here, 
recourse  is  sometimes  had  to  blasting  by  gunpowder.  This  is  done  in  order  either  to  re- 
cover the  bottom  part  or  ground  of  the  vaults  on  which  the  fire  can  act  but  imperfectly, 
to  clear  away  some  projections  which  would  interfere  with  the  effect  of  the  pile,  or  lastly 
to  strip  the  surrounding  rock  from  the  mass  of  the  ore,  and  thence  to  obtain  schist  proper 
for  the  construction  of  the  rubbish-terraces. 

The  blasting  process  is  employed  when  the  foremen  of  the  workshop  or  mine- 
chamber  judge  that  a  hole  well  placed  may  separate  enough  of  ore  to  pay  the  time,  the 
repair  of  tools,  and  the  gunpowder  expended.  But  this  indemnification  is  raiely  obtain- 
ed. The  following  statement  will  give  an  idea  of  the  tenacity  which  the  mineral  deposite 
often  presents. 

In  1808,  in  a  portion  of  the  Rammelsberg  mine,  the  ore,  consisting  of  txtremely  com- 
pact iron  and  copper  pyrites,  was  attacked  by  a  single  man,  who  bored  a  mining  hole. 


MINES. 


189 


Afto,  11  «n«t,  nf  obstinate  labor,  occupying  altogether  88  hours,  the  workman,  being 
^•1  1  ^IrrntpS  had  been  able  to  advance  the  hole  to  a  depth  of  no  more  than 
vigilant  y  ^»PJ"^^/Xh  he  had  rendered  entirely  unserviceable  126  punches  or  borers, 
tS  s'ie"  ht^'wL'^^^^^^^^  been  re-tipped  with  V  and  201  which  ha  be  harp- 
ened;  6i  pounds  of  oil  had  ^^.^-^^l^^;:  'TlsTo^Tr^rt  ^c2^nt^^ 
^^^Zi::.:^^^^^^^^^  n^lnes,  ^J^^I<^ee,  of  this  hole  cost, 

ereat  weret^ch    Ss  a^  and  dearer  than  it  still  is  at  Rammelsberg,  inining  by 

great,  ^f f\™"r"  '^^* ,  .^  ._^_y  o^her  mode  of  exploitation.  It  is  even  certain,  that 
fire  would  be  Ffff^J^^^'^Xv^^ero^^  not  be  practicable  for  every 

on  any-^  f  ^PP^^^'^^^'^^^P  -f  fudcame  to  fail,  it  would  be  requisite  to  renounce  the 
^l!l:':rZ^r.%:k%^^^^         -untam  still  contains  a  large  quantity  of 

"^^i.  all  mii^s  the  n^ci^tiori  of  t  b.  -  ^^^^^  JJ^^  j^^^  m^d^^? 
"^"'/  r^tnn^^Z^r^fZ^^^^^  the  a"r  at  n2^  Fahr.,  when  the  workmen  return 

f„?n  ifarrX  HLst^^^^^  the  piles,  and  in  which  besides  it  is  necessary  that  this 
into  It  ^.tter  the  comDusiiu^^  activity  in  their  absence.  But  in  consequence  of  the  extent 
Tnf  mS  mmS^^^^^^  the  number  of  the  shafts,  galleries,  and  thdr 

Srffprences  cfTvel  the  ventilation  of  the  mine  is  in  a  manner  spontaneously  maintained. 
tS^S  temperature  is  peculiarly  favorable  to  it.  The  aid  of  art  consists  merely  in 
5tLf  some  do^rs  jUci^       which  may  be  opened  or  shut  at  pleasure,  to  carry  on 

'''ln"itlJ"eL'^''he''Rammelsberg  from  its  summit,  which  rises  about  400  yarfs 
in  consiaerino   i"f  ^*        oh^enre  fir^t.  beds  of  slaty  sandstone,  which  become  the 
above  the  town  ^^ fosla^^^f^^^  surfacl     At  aboit   160  yards  below 

Srton  leve/t^^^^^^^^  l^^om  of  the  slaty  graywacke,  a  powerful  stratum  of 

IhPlls  [mnasted  fn  a  fS^^^^  sandstone.     See  d,  fig-  963.     In  descending  to^.-ards  the 

Shells  impasted  in  a  lerrugmoua^^^  ^^  ^^^  ^^^^  ^^^  ^^re^M  stratification  of  the  clay-slate 

which  forms  its  walls  and  roof  grows  more  and  more 
manifest.  Here  the  slate  is  black,  compact,  and  thinly 
foliated.  The  inclination  of  the  difterent  beds  of  rock 
is  indicated  at  b.  The  substance  of  the  workable  mass 
is  copper  and  iron  pyrites,  along  with  sulphuret  of  lead, 
accompanied  by  quartz,  carbonate  of  lime,  compact  sul- 
phate of  baryta,  and  occasionally  gray  copper  i/ahlerz), 
sulphuret  of  zinc,  and  arsenical  pyrites. 

The  ores  are  argentiferous  and  auriferous,  but  very 
slightly  so,  especially  as  to  the  gold.  It  is  the  ores  of 
lea'd  and  copper  which  contain  the  silver,  and  m  the  latter 
the  gold  is  found,  but  without  its  being  well  ascertained  in 
what  mineral  it  is  deposited.  Sometimes  the  copper 
occurs  in  the  native  state,  or  as  copper  of  cementation. 
Beautiful  crystals  of  sulphate  of  lime  are  found  in  the  old 
workings.  .  , 

In  figs.  969.  970,  A  b  is  the  shaft  of  extraction,  called 
the  Kahnenkuhler  ;  N  is  the  ventilation  shaft,  called  BreiU 
lingerwetterschacht ;  p  is  th3  extraction  shaft,  called  Innier- 

E  F,  is  a  new  extraction-shaft,  called  Neuer  treibschacht, 
bv  which  also  the  water  is  pumped  up ;  by  a  b,  and  e  r. 


the  whole  extraction  and  draining  are  carried  on.  The 
ores  are  raised  in  these  shafts  to  the  level  of  the  wagon- 
gallery  (galerie  de  roulage)  t,  by  the  whims  1,  q,  provided 
with  ropes  and  buckets.  1,  2,  3,  4,  fig,  969,  represent 
the  positions  of  four  water-wheels  for  working  the  whims; 
the  first  two  being  employed  in  extracting  the  ores,  the 
last  two  in  draining.  The  driving  stream  is  led  to  the 
wheel  1,  along  the  drift  I ;  whence  it  falls  in  succession 
upon  the  wheds  2,  3,  4.     The  general  system  of  working  consists  of  the  followmg 

operation  : —  ...   i^___^k 

1.  The  bed  of  ore  is  got  at  by  the  transverse  galleries,  m,  n,  o,  </,  r,  »,  wfticn  oranco 
oflf  from  the  extraction  shaft,  and  terminate  at  the  wall  of  the  main  bed ; 

2.  Greai  vaults  are  scooped  out  at  the  level  of  the  workings,  by  means  of  tire ; 


190 


MINES. 


n   !" 


2.  Great  vaults  are  scooped  out  at  the  level  of  the  workings,  by  means  of  fire; 

3.  The  roofs  of  these  vaults  are  progressively  propped  vtith  mounds  of  rubbish; 

4.  The  ores  thus  detached,  or  by  blasting  with  gunpowder,  are  then  collected ; 

5.  Lastly,  they  are  wheeled  out  to  the  day ;  and  washed  near  z. 

CJoMPARATiVE  Table  of  Celebrated  Mines  in  Europe  and  America.     By  F.  Burr,  Esq 
(Quarterly  Mining  Review  for  July,  1835,  p.  60.) 


Situation 
■ElcTation 


Naton  of  Ute  rock 


consolidatcd  and 
Unitkd  Minks. 

(At  preicnt  the  richest 
miues  in  Cornwall.) 


Nature  of  the   me- 
tallilerous  deposit! 


Two  mile*  eaat  of  Redruth. 

Eleration  of  the  surface 
above  the  level  ot  the 
•ea,  from  800  to  WO  ft.; 
depth  of  the  bottom  of 
the  mine  below  the  leve 
of  the  sea,  about  1,370 
feeU 

Primary  clay  state  resting- 
immediately  on  ^anite 
a  short  distance  west- 
ward of  the  mines.  The 
clay  slate  is  intersected 
by  numerous  channels  of 
porphyry,  whicn  have 
nearly  the  same  direction 
as  the  mineral  veins,  and 
are  often  of  considerable 
wiilih.  The  porphyry 
sometimes  appears  also 
to  form  larj-e  irreg-iilar 
masses  in  the  clay  slate. 
Both  rocks  are  traversed 
by  veins  of  quartz  and 
clay  intersectioi^  the  me- 
tailiferous  veiua. 


Veta  Grands  Minis. 

(At  present  the  richest 
muies  in  Mexico.) 


Four  miles  north  of  Za- 
catecas. 

Elevation  of  the  surface 
above  the  level  of  the 
■ea,  supposed  to  be  about 
6000  feet.  Elevation  of 
the  bottom  of  the  mine 
above  the  level  of  the  sea, 
probably  near  5,000  feet. 

Transition  clay  slate,  alter- 
nating with  dolomite, 
and  occasionally  with 
greywacke.  This  clay 
state  is  sometimes  de- 
composed ;  it  rests  on 
■yenitic  rocks,  and  is  in 
some  places  covered  with 
porphyry. 


Mink  orVALKNcuNA 

(Hicbest  of  the  Meaicao 

mines  at  the  oeginnin^  of 

the  present  century.) 


OM 


Produce  of  the  erea 


In  the  consolidated  mines, 
the  eight  following'  lodes 
are  extensively  worked : — 
Wheal  Fortune  lode, 
Cusvea  lode,  Deeble's 
lode.  Old  lotle,  Taylor's 
lode,  Trew'onning's  lode, 
Martin's  lode,  and  Glo- 
ver's lode.  In  the  united 
mines,  the  principal 
working  are  upon  the 
Old  lode,  and  about  five 
or  six  others  are  more  or 
less  productive.  Nume- 
rous smaller  lodes  or 
"  branches"  occur  also 
in  both  mines.  The 
principal  lodes  are  from 
I  or  3,  to  7  or  8  feet  wide ; 
the  "  branches"  are  gen- 
erally IS  or  18  inches 
wide.  Tha  direction  of 
the  lodes  varies  from 
nearly  east  and  west  to 
about  90  degrees  north  of 
east  and  south  of  west. 
The  underlie  of  the  prin- 
cipal lodes  is  from  S  to 
S  feet  per  fathom  north, 
thai  of  the  smaller  ones 
about  the  same  south. 

Chiefly  copper  ore,  occa- 
sionally native  copper, 
blue  and  green  carbonate 
of  copper.  Tin,  or  oxide 
of  tin,  also  occurs,  but 
not  in  very  g'reat  abun- 
dance. 

9J  per  cent  of  fine  copper 
average    produce  in   100 
parts  of  ore. 


VeioatoM 


Mineral  substances 
accompanying  the 
ores 


Depth  of  the  princi- 
pal shafts 


Chiefly  quartz,  of  which 
many  varieties  occur. 

The  ores  are  generally  ac- 
companied by  "ofossan"* 
in  the  backs  of  the  lodes, 
by  blende,  and  by  iron, 
and  arsenical  pyrites  in 
depth. 

Woolft  ensine-thnft,  248 
fathoms;  Pearce  s  en- 
Me-tkaft,  875  fathoms. 
Some  of  the  other  en- 
gine shafts  are  scarcely] 
•nferior  in  demh.  ' 


One  principal  vein  (the 
Veta  Grande)  which  is 
generally  separated  into 
three  branches,  and 
sometimes  mto  four. 
When  ramified,  the 
width  extends  to  60  or 
70  feet;  when  united, 
it  varies  from  8  or  10  to 
80  or  30  feet.  The 
branches  are  generally 
about  10  or  19  feet  wide  ; 
and  the  upper  one  is 
most  productive.  The 
direction  of  the  Veta 
Grande  is  from  SO  to 
40  degrees  south  of  east, 
and  north  of  west,  and 
its  underlie,  from  two  to 
three  feet  per  fathom 
south.  Other  veins  of 
less  size  occur  in  the 
neighbourhood  of  the 
Veta  Grande,  which 
cross  it  at  an  acute  angle 
One  of  these  appears 
to  heave  the  vem  for 
about  700  feet,  being  the 
most  remarkable  de- 
rangement of  the  kind 
on  record. 

Chiefly  red  silver,  native 
silver,  sulphuret  of  silver, 
and  arg'eniiferoua  pyrites. 


S|  oz.  per  quintaL 


One  mile  north  of  Gua- 
naxuaio. 

Elevation  of  the  surface 
above  the  level  of  the  sea, 
7,617  feet.  Elevation  of 
the  bottom  of  the  mine 
above  the  level '  of  the 
sea,  5,730  feeu 


The  Veta  Madrt  of  Gua 
naxuato,  upon  which 
this  mine  is  worked,  tra- 
verses both  clay  slate 
and  porphyry,  but  it  is 
most  productive  in  the 
former  rock.  The  clay 
slate  ia  considered  by 
Humboldt  to  belong  to 
the  transition  class,  but 
situate  near  the  limits  of 
primary  formations.  This 
rock  in  depth  passes  into 
chlorite  slate,  and  talc 
slate.  It  contains  sub- 
ordinate beds  of  syenite, 
hornblende  slate,  and 
serpentine.  The  por- 
phyry rests  upon  the  clay 
slate,  and  is  conformable 
to  it,  both  in  direction 
and  stratification. 

One  Veta  (the  Veta 
Madre)  which  is  often 
separated  into  three 
branches,  extending  from 
130  to  160  feet  in  width. 
When  not  ramified,  its 
width  varies  from  90  or 
90  to  60  or  70  feet,  but 
is  more  commonly  from 
40  to  50  feet.  The 
direction  of  the  vein  is 
north-west  and  south- 
east- its  underlie  is 
south,  and  about  five  or 
six  feet  per  fathom. 


Mink  op 

HlMMKLS*i)RST. 

(Richest  uf  the 

34Xon  mines  at  the 

beginning  of  the 

present  century.) 


Two  miles  south- 
east of  Freybtirg. 

Elevation  of  the  sur- 
face atcve  the 
level  of  '.he  sea, 
1,346  feet.  Eleva- 
tion of  the  bot- 
tom of  the  mine 
above  the  level  of 
the  sea,  263  feet. 

The  rock  prevailing 
in  the  neighbour 
hood  of  Freyberg, 
in  which  this  and 
most  of  the  other 
mines  are  situate, 
is  a  formation  of 
primary  fneist. 


Chiefly  quartz,  occasionally 
amethyst,  carbonate  of 
lime,  and  sulphate  of 
barytes. 

The  ores  are  generally  ac- 
companied by  blende, 
sulphuret  of  antimony, 
and  iron  pyrites. 


Tiro  General,  189  fathoms ; 
GnUe^a  shaft,  133  fa- 
thoms. 


Sulphuret  of  silver,  native 
silver,  prismatic  black 
silver,  red  silver,  native 
gold,  argentiferous  ga- 
lena. 


Four  ounces  of  silver  per 
quintal  of  100  lbs.,  equi- 
valent to  t\  pains  of 
metal  in  1,000  of  ore,  or 
^  per  ceau 


There  are  ftve  reins 
worked  m  this 
mine.  The  prin- 
cipal vein  {Teick 
Jlache)  is  from  one 
foot  six  inches  to 
three  feet  in  width, 
the  others  are  from 
six  to  twelve  inches 
wide.  The  direc 
tion  of  this  vein 
is  nearly  north 
and  south,  its  un 
deriie  is  west,  and 
about  three  feet 
per  fathom.  Some 
of  the  other  veins 
intersect  it. 


Arrrntiferoua  tul- 
ptiuret  of  lead, 
native  silver,  sul- 
phuret of  silver, 
red  silver. 


Quartz,     amethyst, 
bonate  of  lime,  pearlspar, 
and  homstone. 


Six  to  seven  euneei 
of  silver  per  (quin- 
tal of  100  It*. 
Equivalent  to 

from     31      to      4} 

flirts    of   metal  in 
,000     cf     ore,    or 
from       3-Sths       to 
nearl  f  \  per  cent. 
car-|  Quartz,   '    pearlspar, 
and  calcareous 

spar. 


The  ores  are  accompanied 
by  blende,  spathose  iron, 
copper  and  iron  pyrites. 


Tiro  General,  810  fathoms. 


The  ores  are  ac- 
companied bj 
blende,  spathose 
iron,  and  a  little 
iron  and  araenical 
pyrites. 

Frankentchat:htt  180 
fathoms. 


GoSaan,  or  Gozzan ;  oxide  of  iron  and  quartz. 


MINES. 

CoMFARATivE  Table  of  celebrated  Mines  in  Europe  and  America. 
By  F.  Burr,  Esq. — Continued, 


191 


Depth  of  adit  at  the 
principal  shafts 


Quantity  of  water 


Consolidated  and 
United  Mines. 

(At  present  the  richest 
mines  in  Cornwall.) 


Height  tc  which  the 
water  is  raised 


Power  employed    in 
dratna^ 


Probable  equivalent 
in  actual  horse- 
power 

Average  annual  ex- 
pense in  drainage 

Quantity  of  ore  an- 
nually produced 

Produce  in  metal 

Total  returns,  or 
value  of  the  above 

Total  cosu  of  the 
mine 

Clear    profit    to    the 

proprietors 
Amount    of    capital 

invested 


Interest   on    capital 
invested 

Proportion  of   coats 
to  returns 


At  Woolf's  ensine-shaft, 
13  fathoms.  The  average 
depth  of  the  adit  at  the 
other  engine-shafts  is 
about  30  or  40  fathoms. 

Varies  from  2,000  to  3,000 
gallons  per  minute. 


VetaGrandk  Minks. 

( At  present  the  richest 
mmes  in  Mexico.) 


There  is  no  adit  to  this 
mine. 


About     80 
minute. 


g^lons     per 


About  830  fathoms  at  the 
consolidated  mines,  at 
the  united  mines,  about 
110  fathoms. 

9  steam-engfines ;  3  of  90- 
inch  cylinder,  3  of  85,  1 
of  80,  and  8  of  65.  A 
water  wheel,  48  feet  in 
diameter. 

1,500  constantly  at  work, 
or  a  total  number  of 
above  4,500. 


19,7002.  taking  the' 
average  of  tne  last 
ten  years. 

16,400  tons  of  copper 
ore,  a  few  tons  of  tin 
ore. 

1,517  tons  of  fine  cop- 
iier,  a  little  tin. 

119,800/. 

93,500/.  exclusive  of 
lord's  dues;  98,500/. 
inc  I  uding  lord's  dues. 

91,000/.  per  annum. 


Number  of  men  em- 
ployed 

Wages  of  the  miners 

per  day 
Quantity    and     ex 

Dense  of  powder 
Manner     in     which 

the    orea   are  diS' 

posed  of 


75,000/. 


980  per  cent,  after  pay- 
ing back  the  original 
capital. 

Costa  exclusive  of  lord's 
dues,  78  per  cent.       , 


Mink  or  Valknciana 

(Richest  of  the  Mexican 

mines  at  the  beginning  of 

the  present  century.) 


On  an  average 
fathoms. 


about  150 


of 


About    9,500    persons, 
whom    about    1,450    are 
employed  under  ground. 

Probably  about  S  shillings 
on  an  average. 


Sold  to  the  smelting  com- 
panies, and  smelted  by 
them  at  Swansea,  in 
South  Walea. 


Usually  10  malacates.* 


S2  horses  constantly 
working,  or  a  total 
number  of  about  100 
horses. 

90,000/.  per  annum. 


81,380    torn    of   silver 

ore. 

153,000     lbs.    troy    of 

silver. 
493,400/.  per  annum. 

958,170/.  per  annum. 


171,940/.  per  annum 
130,000/. 


Nearly  700  per  cent, 
after  paying  back  the 
original  capital. 

About  59i  per  cent. 


About  900,  of  whom  nearly 
600  are  employed  under 
ground. 

About  8  or  9  shillings  per 
day. 

Chiefly  reduced  by  the 
company  at  the  hacienda 
of  Sanceda,  by  smelting 
and  amalgamation. 


There  ia  no  adit  to  this 
mine. 


The  Valenciana  was  a  dry 
mine     from     its     com- 
mencement   in     1760    to 
1780,  when   it   first   be 
came    _  troubled      with 
Water,  in  consequence  of 
Borne    of     the   workings 
being  inadvertently  com 
municated  with   the  ad 
Joining  mine  uf  Tepeyac ; 
which,     although     upon 
the  same  vein,  was  ex 
tremely  wet.     The  quan 
tity  of  water  raised  during 
the  late  working  appears 
to  have  been  about    1 10 
g'allons  per  minute,  but 
the   regular   iuttux   was 
much  less. 

310  fathoms. 


A  steam-engine  of  30  inch 
cylinder,  and  7  mala- 
cates. 


65  horses  constantly  at 
work,  or  a  total  number 
of  about  SiOO. 


About      40,000/.      per' 
aiiniun. 


39,500   tona    of   ailver 
ore. 

222,900  lbs.  troy  silver. 

About  600,000/. 


Mink  op 

HlMMELSFiJRST. 

(Richest  of  the 

Saxon  mines  at  the 

beginning  of  the 

present  century.) 


The  adit  at  the  shaft 
called  frankeH- 
0chackt,  is  47  fa- 
thoms in  depth. 


50        gallons 
minute. 


per 


197,900/.  per  annum. 

1 18,750/.  per  armum. 

Cannot  be  ascertained, 
but  known  to  have 
been  very  small. 


Not  known,  but  cer- 
tainly many  hundred 
per  cent. 

Costs  60  per  cent.  In 
the  nine  years  follow- 
ing, the  proportion 
was  80  per  cent.,  at 
the  end  of  that  time 
the  working  of  the 
mine  was  stopped  by 
the  revolution,  in  the 
year  1809. 

3,100  Indians  and  Me'sti- 
zoes,  of  whom  1800  are 
employed  underground. 

From  4  to  6  shillings. 

1,480  cwt.;  value  15,830/. 

Sold  to  the  Re^cntadorety 
and  reduced  by  smelting 
and  amalgamation  at 
haciendas,  in  the  neigh- 
bourhood of  Guanaxuato. 


113  fathoma. 


Two  water-wheels, 
each  49  feet  in 
diameter. 


16  horses  eon- 
atantly  at  work, 
or  a  total  num- 
ber of  about 
50. 

Cannot  be  ascer- 
tained, but 
evidently  very 
small. 

630  tons  of  silver 
ore. 


6,160  lbs.  troy  of 

silver. 
About  18,000/. 

9,500/.  per  an- 
num. 

3,560/.  per  an- 
num. 

Cannot  be  ascer- 
tained, but 
probably  very 
small. 

Not  known,  but 
probably     very 

Costs  79  per 
cent. 


? 


700  miners,  of  whom 
550  are  employed 
under  s-round. 

About  Is.  id.  per 
day. 

940  cwt. ;  Taluc 
1,070/. 

Delivered  to  the 
Government,  re 
duction  works  in 
the  neighbourhood 
of  Freyberg,  where 
they  'are  partly 
smelted,  and  part- 
ly amalgamated. 


VENTILATION   OF   MINES. 

When  men  penetrate  by  narrow  passages  into  the  interior  of  the  earth,  their  respir- 
ation, joined  to  the  combustion  of  candle  and  gunpowder,  are  not  long  of  vitiating 
the  ai».  The  decomposition  of  wood  contributes  to  the  same  effect,  as  also  the 
mineral  bed  itself,  especially  in  coal  mines,  by  the  carburetted  hydrogen  and  carbonic 
acid  evolved,  and  from  the  absorption  of  oxygen  by  pyrites.  In  many  cases,  arsenical 
and    mercurial    vapours   are    disengaged.     Hence    the    necessity  of  maintaining  in   sub. 

*  MnlacatP;  n  h«>rse  wtuiu 


192 


MnvTT. 


MINES. 


ii 


193 


Mill 


terranean  cavUies  a  continual  circulation  of  air,  which  may  renew  the  atmosphere  round 
the  miners.  The  whole  of  the  means  employed  to  produce  this  eflect,  constitutes  what 
IS  called  the  ventilation  of  mines. 

These  means  are  divided  into  natural  and  artificial.  The  natural  means  are  the  cur. 
rents  produced  by  the  difference  of  density  between  the  air  of  mines  and  the  external 
air ;  the  artijirtal  are  air-exhausters  or  condensers,  fires,  &c. 

The  temperature  of  the  air  of  the  subterranean  workings  surpasses  the  mean  tem- 
perature of  the  place  in  which  the  mine  is  opened.  Hence  it  is  lighter  in  winter, 
but  m  summer  often  heavier  than  the  air  of  the  atmosphere.  For  this  reason,  when  the 
mine  presents  two  openings  at  different 'evels,  the  air  naturally  flows  out  by  the  most 
elevated  in  winter,  and  by  the  lowest  in  summer.  We  may  take  advanta<^e  of  this 
circumstance,  to  lead  the  air  into  the  bottom  of  even  a  very  long  gallery,  opening  into 
ine  sideol  the  mountain,  by  piercing  a  shaft  into  its  roof  at  some  distance  from  the 
entrance,  and  dividing  the  gallery  by  a  horizontal  floor  into  two  parts,  which  have  no 
mutual  communication,  except  at  the  furthest  extremity— the  upper  part  communica- 
tmg  with  the  shaft,  and  the  under  with  the  mouth  of  the  gallery.  If  the  two  compart- 
ments have  different  dimensions,  the  air  in  the  smaller  sooner  comes  into  an  equilibrium 
of  temperature  with  the  rock ;  and  the  ditierence  of  temperature  of  the  two  compart- 
ments is  sufficient  to  produce  a  current.  If  a  streamlet  of  water  flows  through  this 
gallery,  it  facilitates  the  flow  of  the  air  along  the  lower  compartment.  If  a  mine  has 
several  openings  situated  on  the  same  level,  it  rarely  happens  but  some  peculiar  circum- 
stance destroys,  during  the  colds  of  winter  and  the  heats  of  summer,  the  equilibrium  of 
the  air.  But  m  spring  and  autumn,  when  the  external  air  is  nearly  of  the  same  tem- 
perature with  that  of  tlie  mines,  the  above-named  causes  are  almost  always  too  feeble  to 
excite  an  issuing  current.  This  effect  is,  however,  frequently  obtained  by  raising  over 
one  of  the  shafts  a  chimney  20  or  30  yards  high,  which  alone  produces  the  eflect  of  an 
opening  at  a  different  level.  It  has  been  remarked  that  stormy  weather  usually  deran^'es 
every  system  of  ventilation.     See  Pitcoal  and  Ventilation.  ^ 

MINES,  BLASTING.  It  has  been  often  noticed  that  since  the  application  of  gun- 
powder for  blasting,  few  if  any  improvements  have  been  made  in  the  methods  adopted 
lor  cutting  through  hard  rocks ;  and  the  great  expense  of  maintaining  engine  powei 
for  pumping  and  winding  during  the  long  period  required  to  sink  shafts  through  such 
rocks  has  been,  and  still  is  the  sole  cause  of  some  of  the  best  and  richest  tracts  oJ 
minerals  in  Oreat  Britain  lying  idle  and  unproductive,  and  has  been  the  principal  cause 
of  the  loss  of  lite  so  serious  and  often  occurring  from  explosion  in  mines. 

The  improvements,  or  rather  the  new  system  now  intix)duced,  will  be  better  under- 
stood alter  a  review  of  the  methods  and  tools  heretofore  used. 

The  oldest  method  of  pumping,  or  taking  up  the  water  from  the  bottom  of  the  shaft 
during  sinking  was  the  Hogar  pipe;  this  was  about  4  feet  in  length,  made  of  leather, 
and  stiffened  by  rings  of  metal :  the  constant  damage  this  was  liable  to  in  blasting 
caused  it  to  be  almost  abandoned,  and  in  its  place  the  stock  and  slide  pipe  was  intro- 
duced. This  consists  of  two  cast-iron  pipes  sliding  into  each  other  as  a  telescope  and 
kept  tight  m  the  joint  by  a  stuflfing-box;  this  contrivance  is  not  only  expensive  in  first 
cost,  but  liable  to  breakage  and  heavy  to  handle.  Both  these  modes  of  pumping  are 
subject  to  a  still  greater  defect;  the  pump  can  only  be  made  nearly  under  the  pump 
trees,  so  that  during  a  long  time  of  the  sinking  it  often  occurs  that  only  two  or  three 
men  can  be  effectually  emplo\'ed  in  the  shaft;  this  in  some  of  the  large  shafts  (say  on 
a  common  size  used  in  South  Wales,  18  feet  by  10  feet)  causes  serious  delay  in  the  pro- 
gress of  the  work.  ^ 

In  boring  it  has  been  customary  to  use  a  borer,  the  body  of  which  was  ma'de  ot 
wrought  iron,  and  the  bit  or  end  of  the  borer  of  shear  steel  welded  on  the  iron.  No 
attempts  appear  ever  to  have  been  made  to  fix  any  definite  proportion  between  the 
size  of  the  stock  or  handle  and  the  breadth  of  the  bit ;  and  from  this  cause  a  very 
great  portion  of  the  power  of  the  striker  has  been  uselessly  expended. 

The  use  of  cast  steel  borers  is,  in  some  respects,  entirely  new  as  applied  to  mining, 
and  by  the  superior  hardness  of  cast  steel  as  compared  with  shear  steel,  greatly  expS* 
dites  the  process  of  boring  and  saves  expense;  they  have  also  an  advantage  in  trans 
mitting  the  force  of  the  hammer  to  the  bit,  on  account  of  their  stiffness  or  rigidity 
and  further  to  prevent  loss  of  power,  it  is  of  importance  that  the  bit  should  be  so  pnv 
portioned  to  the  handle  or  stock  as  to  work  freely  in  the  bore-hole,  and  at  the  same 
time  spring  or  bend  as  little  as  possible  under  the  blow  of  the  hammer.  The  following 
proportions  appear  to  answer  these  conditions.     (See  top  of  next  page.) 

The  suction  pipe  now  used  by  the  exhibitor,  about  20  feet  in  length,  is  made  of  gutto 
percha,  and  supersedes  the  use  of  the  leather  Hogar,  and  the  stock  and  slide ;  it  is  not 
bable  to  accident,  and  can  be  repaired  easily ;  it  enables  the  pump  slide  to  be  made  in 
any  part  of  the  shafts  and  a  greater  number  of  men  to  work  it  in  the  shaft  at  one  time. 


Diameter  of 
Octagon  Cast  SteeL 
1     inch. 


1* 

H 


»» 


»» 


*t 


Breadth  of 

the  face  of  Bit. 

1|  inch. 

H    « 

2 

2i 

2*     „ 

TTie  introduction  of  electricity  as  the  power  for  blasting  in  connection  with  the 
improvements  before  explained,  may  be  said  to  constitute  a  new  era  in  the  history  of 
mining. 

The  apparatus  at  present  used  for  blasting  is  Grove's  battery  of  6  inches  square :  this 
is  placed  in  some  convenient  position  near  the  top  of  the  shaft ;  two  copper  wires,  coated 
with  gutta  percha,  are  carried  down  the  shafts,  and  these  are  connected  with  the  other 
wires  inserted  in  a  small  cartridge  which  is  placed  in  the  charge  of  powder  for  blasting. 
MINES.     The  miner,  in  sinking  into  the  earth,  soon  opens  up  numerous  springs,  whose 
waters,  percolating  into  the  excavations  which  he  digs,  constitutes  one  of  the  greatest 
obstacles  that  nature  opposes  to  his  toils.     When  his  workings  are  above  the  level  of 
some  valley  and  at  no  great  distance,  it  is  possible  to  get  rid  of  the  waters  by  leading  them 
along  a  trench  or  a  gallery  of  efflux.     This  forms  always  the  surest  means  of  drainage ; 
and  notwithstanding  the  great  outlay  which  it  involves,  it  is  often  the  most  economical. 
The  great  advantages  accruing  from  these  galleries,  lead  to  their  being  always  estab- 
lished, and  without  risk,  in  mines  which  promise  a  long  continuance.     There  are  many 
galleries  several  leagues  in  length  ;  and  sometimes  they  are  so  contrived  as  to  discharge 
the  waters  of  several  mines,  as  may  be  seen  in  the  environs  of  Fieyberg.     Merely  such 
a  slope  should  be  given  them  as  is  barely  sufficient  to  make  the  water  run,  at  the  ut- 
most from  Tj-i—  to  Jo o>  ^^  ^^  ^^  drain  the  mine  at  the  lowest  possible  level. 

Whenever  the  workings  are  driven  below  the  natural  means  of  drainage,  or  below 
the  level  of  the  plain,  recourse  must  be  had  to  mechanical  aids.  In  the  first  place,  the 
quantity  of  percolating  water  is  diminished  as  much  as  possible  by  planking,  walling, 
or  calking  up  with  the  greatest  possible  care  those  pits  and  excavations  which  traverse 
the  water  levels  ;  and  the  lower  workings  are  so  arranged  that  all  the  waters  may  unite 
into  wells  placed  at  the  bottom  of  the  shafts  or  inclined  galleries ;  whence  they  may  be 
pumped  up  to  the  day,  or  to  the  level  of  the  gallery  of  efflux.  In  most  mines,  simple 
sucking  pumps  are  employed,  because  they  are  less  subject  to  give  way,  and  more  easy 
of  repair ;  and  as  many  of  these  are  placed  over  each  other,  as  the  shaft  is  ten  yards 
deep,  below  the  point  where  the  waters  have  a  natural  run. 

These  draining  machines  are  set  in  motion  by  that  mechanical  poWer  which  happens 
to  be  the  least  costly  in  the  place  where  they  are  established.  In  almost  the  whole  of 
England,  and  over  most  of  the  coal-mines  of  France  and  Silesia,  the  work  is  done  by 
steam-engines ;  in  the  principal  metallic  mines  of  France,  and  in  almost  the  whole  of 
Germany  and  Hungary,  by  hydraulic  machines ;  and  in  other  places,  by  machines 
moved  by  horses,  oxen,  or  even  by  men.  If  it  be  requisite  to  lift  the  waters  merely  to 
the  level  of  a  gallery  of  efflux,  advantage  may  be  derived  from  the  waters  of  the  upper 
parts  of  the  mine,  or  even  from  waters  turned  in  from  the  surface,  in  establishing  in  the 
mine  of  the  gallery-level,  water-pressure  machines,  or  overshot  water-wheels,  for  pump- 
ing up  the  lower  water.  This  method  is  employed  with  success  in  several  mines  of 
Hungary,  Bohemia,  Germany,  Derbyshire,  Cornwall,  in  those  of  Poullaouen  in  Brittany, 
&c.  It  has  been  remarked,  however,  that  the  copious  springs  are  found  rather  toward 
the  surface  of  the  soil  than  in  the  greatest  depths. 

TRANSPORT   OF   ORES   TO   THE   SURFACE. 

The  ore  being  extracted  from  its  bed,  and  having  undergone,  when  requisite,  a  first 
sorting,  it  becomes  necessary  to  bring  it  to  the  day,  an  operation  performed  in  different 
ways  according  to  circumstances  and  localities,  but  too  often  according  to  a  blind 
routine.  There  are  mines  at  the  present  day,  where  the  interior  transport  of  ores  is 
executed  on  the  backs  of  men;  a  practice  the  most  disadvantageous  possible,  but  which 
is  gradually  wearing  out.  The  carriage  along  galleries  is  usually  effected  by  means  of 
hurdles,  barrows,  or,  still  better,  by  little  wagons.  These  consist  of  frames  resting  on 
four  wheels  ;  two  larger,  which  are  placed  a  little  behind  the  centre  of  gravity,  and  two 
smaller,  placed  before  it.  When  this  carriage  is  at  rest,  it  bears  on  its  four  wheels,  and 
leans  forward.  But  when  the  miner,  in  pushing  it  before  him,  rests  on  its  posterior 
border,  he  makes  it  horizontal;  in  which  case  it  rolls  only  upon  the  two  larger  wheels. 
Thus,  the  friction  due  to  four  wheels  is  avoided,  and  the  roller  or  driver  bears  no  part 
of  the  burden,  as  he  would  do  with  ordinary  wheelbarrows.  To  ease  the  draught  still 
more,  two  parallel  rails  of  wood  or  iron  are  laid  along  the  floor  of  the  gallery,  to  which 
Vol.  U.  13 


194 


MINES. 


MINES. 


195 


a  ;- 


the  wheels  of  the  carriage  are  adjusted.  It  is  especially  in  metallic  mines,  where  the  ore 
is  heavy,  and  the  galleries  straight,  that  these  peculiar  wagons  are  employed.  In  coal 
mines,  carriages  formed  with  a  much  larger  basket,  borne  on  a  railroad  by  four  equal 
wheels,  are  preferred.  Sometimes  the  above  wain,  called  on  the  Continent  a  dog  (chicn), 
is  merely  a  simple  frame  on  four  wheels,  on  which  a  basket  is  set.  In  the  great  mines, 
such  as  many  of  the  coal  and  salt  mines  of  Great  Britain,  the  salt  mines  of  Galhcia,  the 
copper  mines  of  Fahlun,  the  lead  mines  of  Alston-Moor,  horses  and  asses  are  mtroduced 
into  the  workings  to  drag  heavier  wagons,  or  rather  a  train  of  wagons  attached  to 
one  anolhtr.  These  animals  often  live  many  years  under  ground,  without  ever  revisit- 
ing the  light  of  day.  In  other  mines,  such  as  those  of  Worsley,  in  Lancashire,  subter- 
ranean canals  are  cut,  upon  which  the  ore  is  transported  in  boats. 

When  the  workings  of  a  mine  are  beginning,  when  they  are  still  of  little  depth,  and 
employ  few  hands,  it  is  sufficient  to  place  over  the  shaft  a  simple  wheel  and  axle,  by 
means  of  which  a  few  men  may  raise  the  water-pails,  and  the  baskets  or  tubs  filled  with 
ore ;  but  this  method  becomes  soon  inadequate,  and  should  be  replaced  by  more  power- 
ful machines. 

ACCESSORY   DETAILS. 

Few  mines  can  be  penetrated  entirely  by  means  of  galleries.  More  usually 
there  are  shafts  for  mounting  and  descending.  In  the  pits  of  many  rc.nes,  the  work- 
men go  down  and  come  up  by  means  of  the  machines  which  serve  to  elevate  the 
ores.  In  several  mines  of  Mexico,  and  the  north  of  Europe,  pieces  of  wood,  hxed 
on  each  side  of  the  pit,  form  the  rude  steps  of  a  ladder  by  which  the  workmen  pass  up 
and  down.  In  other  mines,  steps  are  cut  in  the  rock  or  the  ore ;  as  in  the  quicksilver 
mines  of  Idria  and  the  Palatinate,  in  the  salt  mines  of  Wieliczka,  and  in  some  ot  the 
silver  mines  of  Mexico.  In  the  kist  they  serve  for  the  transport  of  the  ore,  which  is 
carried  up  on  men's  backs.  Lastly,  certain  mines  are  entered  by  means  of  slopes, 
some  of  which  have  an  inclination  of  more  than  30^.  The  workmen  sbde  down  these 
on  a  kind  of  sledge,  whose  velocity  of  descent  they  regulate  by  a  cord  hrmly  faxed  at 

the  upper  end.  ,  ,,      .       ,  r     /v 

Miners  derive  light  from  candles  or  lamps.  They  carry  the  candles  m  a  lump  of  soft 
clay,  or  in  a  kind  of  socket  terminated  by  an  iron  point,  which  serves  to  fix  it  to  the 
rock,  or  to  the  timbering.  The  lamps  are  made  of  iron,  hermetically  closed,  and 
suspended,  so  that  thev  can  not  droop,  or  invert  and  spill  the  oil.  They  are  usually 
hun«'  on  the  thumb  bv  a  hook.  Miners  also  employ  small  lanterns,  suspended  to  their 
eirdles.  Many  precautions  and  much  experience  are  requisite  to  enable  them  to  carry 
these  lights  in  a  current  of  air,  or  in  a  vitiated  atmosphere.  It  is  especially  in  coal 
mines  liable  to  the  disengagement  of  carburetted  hydrogen,  that  measures  of  safety  are 
indispensable  a-ainst  the  explosions.  The  appearance  of  any  halo  round  the  flame 
should  be  carefully  watched  as  indicating  danger;  and  the  lights  should  be  carried 
near  the  bottom  of  the  gallery.  The  great  protector  against  these  deplorable  accidents, 
is  the  safety  lamp.     See  Lamp  of  Davy. 

We  can  not  conclude  this  general  outline  of  the  working  of  mines,  without  giving 
some  account  of  the  miners.  Most  men  have  a  horror  at  the  idea  of  biirymg  them- 
selves, even  for  a  short  period,  in  these  gloomy  recesses  of  the  earth.  Hence  mining 
operations  were  at  first  so  much  dreaded,  Ihat,  among  the  ancients,  they  were  assigned 
to  slaves  as  the  punishment  of  their  crimes.  This  dislike  has  diminished  with  the  im- 
provements made  in  mining;  and  finally,  a  profitable  and  respected  species  of  labor 
has  given  mining  its  proper  rank  among  the  other  departments  of  industry.  The  espnt 
de  corps,  so  conspicuous  among  seamen,  has  also  arisen  among  miners,  and  has  given 
dignity  to  their  body.  Like  every  society  of  men  engaged  in  perilous  enterprises,  and 
cherishing  the  hopes  of  great  success,  miners  get  attached  to  their  profession,  talk  of  it 
with  pride,  and  eventually  in  their  old  age  regard  other  occupations  with  contempt. 
They  form,  in  certain  countries,  such  as  Germany  and  Sweden,  a  body  legally  consti- 
tuted, which  enjovs  considerable  privileges.  Miners  work  usually  6  or  8  hours  at  a 
time.    This  period  is  called  a  journey  {posie,  in  French).  .    .  .u 

Miners  wear,  in  general,  a  peculiar  dress,  the  purpose  of  which  is  to  protect  them,  as 
much  as  possible,  from  the  annoyances  caused  by  water,  mud,  and  sharp  stones,  which 
occur  in  the  places  where  they  work.  One  of  the  most  essential  parts  of  the  dress  of  a 
German  miner  is  an  apron  of  leather  fitted  on  behind,  so  as  to  protect  them  in  sitting 
on  moisture  or  angular  rubbish.  In  England,  the  miners  wear  nothing  but  flannels; 
though  they  frequently  strip  off  all  their  clothes  except  their  trowsers.  In  many  coun- 
tries the  mallet  and  the  pick,  or  pointeroUe  (called  m  German  Schegel  and  £t.cn),  dis- 
posed  in  a  Saint  Andrew's  cross,  are  the  badge  of  mmers,  and  are  engraved  on  their 
buttons,  and  on  everything  belonging  to  mines.  *    ♦!,„„  ^„u  „ 

Several  of  the  enterprises  executed  in  mines,  or  in  subserviency  to  them,  merit  a 
distinguished  rank  among  the  history  of  human  labors.  Several  mines  are  worked  to 
a  depth  of  more  than  600  yards,  some  even  to  a  thousand  yards  below  the  surlace  ol  me 


soil.  A  great  many  descend  beneath  the  level  of  the  ocean ;  and  a  few  even  extend 
under  its  billows,  and  are  separated  from  them  by  a  thin  partition  of  rock,  which  allows 
their  noise,  and  the  rolling  of  the  pebbles,  to  be  heard. 

In  1792,  there  was  opened,  at  Valenciana,  in  Mexico,  an  octagonal  pit,  fully  7|  yards 
wide,  destined  to  have  a  depth  of  560  yards,  to  occupy  23  years  in  digging,  and  to  cost 
240,000/. 

The  great  drainage  gallery  of  the  mines  of  Clausthal,  in  the  Hartz,  is  1 1,377  yards,  or 
six  and  a  half  miles  long,  and  passes  upward  of  300  yards  below  the  church  of  Clausthal. 
Its  excavation  lasted  from  the  year  1777  till  1800,  and  cost  about  66,000/.  Several 
other  galleries  of  efllux  might  also  be  adduced,  as  remarkable  for  their  great  length  and 
expense  of  formation. 

The  coal  and  iron  mines  subservient  to  the  iron  works  of  Mr.  Crawshay,  at  Merthyr- 
Tydvil,  in  Wales,  have  given  birth  to  the  establishment,  interiorly  and  above  ground, 
of  iron  railways,  whose  total  length,  many  years  ago,  was  upward  of  100  English 
miles. 

The  carriage  of  the  coal  extracted  from  the  mines  in  the  neighborhood  of  Newcastle 
to  their  points  of  embarkation,  is  executed  almost  entirely,  both  under  ground  and  on 
the  surface,  on  iron  railways,  possessing  an  extent  of  upward  of  500  miles. 

There  is  no  species  of  labor  which  calls  for  so  great  a  development  of  power  as  that 
of  mines;  and  accordingly,  it  may  be  doubted  if  man  has  ever  constructed  machines  so 
powerful  as  those  which  are  now  employed  for  the  working  of  some  mineral  excavations. 
The  waters  of  several  mines  of  Cornwall  are  pumped  out  by  means  of  steam-engines, 
whose  force  is  equivalent  in  some  instances  to  the  simultaneous  action  of  many  hundred 
horses. 

Mines,  General  Summary  of. 

Mines  maybe  divided  into  three  great  classes  :  1.  Mines  in  the  gealogical  formations 
anterior  to  the  coal  strata;  2.  Mines  in  the  secondary  formations  ;  3.  Mines  in  alluvial 
districts. 

The  first  are  opened,  for  the  most  part,  upon  veins,  masses,  and  metalliferous  beds. 

The  second,  on  strata  of  combustibles,  as  coal ;  and  metalliferous  or  saliferous  beds. 

The  last,  on  deposites  of  metallic  ores,  disseminated  in  clays,  sands,  and  other  alinvial 
matters,  usually  superior  to  the  chalk ;  and  even  of  far  more  recent  formation. 

The  mines  of  these  three  classes,  placed,  for  the  most  part  in  very  diflferent  physical 
localities,  differ  no  less  relatively  to  the  mode  of  working  them,  and  their  mechanical 
treatment,  than  in  a  gealogical  point  of  view. 

MINES   OF   FORMATIONS   ANTERIOR    TO    THE    COAL, 

These  mines  are  situated  in  a  few  mountainous  regions,  and  their  whole  amount  forms 
but  a  small  portion  of  the  surface  of  the  earth.  The  most  remarkable  of  these  are^ 
the  Cordilleras  of  South  America;  the  mountains  of  Hungary ;  the  Altayan  mountains; 
the  Ural  mountains ;  the  Vosges  and  the  Black  Forest;  the  Hartz,  and  the  east  of 
Germany  ;  the  centre  of  France ;  the  north  of  Portugal,  and  the  adjacent  portions  of 
Spain ;  Britanny  ;  the  corresponding  coasts  of  Great  Britain  and  Ireland  ;  the  north  of 
Europe  ;  the  Allegany  chain ;  the  south  of  Spain ;  the  Pyrenees  ;  the  Alps ;  the  schistose 
districts  on  the  banks  of  the  Rhine  and  the  Ardennes ;  the  calcareous  mountains  of 
England  and  of  Daouria. 

MINES    OF   THE    CORDILLERAS   OF   SOUTH   AlVIERICA. 

Few  regions  are  so  celebrated  for  their  mineral  wealth  as  the  great  chain  which,  under 
the  name  of  the  Cordillera  of  the  Andes,  skirts  the  shores  of  the  Pacific  ocean,  from  the 
land  of  the  Patagonians  to  near  the  northwest  point  of  the  American  continent.  Who 
has  not  heard  of  the  mines  of  Mexico  and  Potosi  ?  The  mineral  wealth  of  Peru  has 
passed  into  a  proverb. 

The  most  important  mines  of  the  Cordilleras  are  those  of  silver ;  but  several  of  gold, 
mercury,  copper,  and  lead,  have  likewise  been  opened.  These  mountains  are  not  equally 
metalliferous  in  their  whole  extent.  The  workings  occur  associated  in  a  small  number 
of  districts  far  distant  from  each  other. 

In  the  Andes  of  Chili,  particularly  in  the  province  of  Coquimbo,  some  silver  mines 
are  explored,  which  afford  chiefly  ores  of  an  earthy  or  ferruginous  nature,  mingled  with 
imperceptible  portions  of  ores  with  a  silver  base,  known  thereunder  the  name  of  Pacos. 
The  same  province  also  presents  copper  mines  of  considerable  importance,  from  which 
are  extracted  native  copper,  orange  oxide  of  copper,  carbonate  of  copper  (malachite), 
and  copper  pyrites,  associated  with  some  muriate  of  copper.  In  a  few  mines,  masses 
of  native  copper  of  extraordinary  magnitude  have  been  found. 

The  second  metalliferous  region  of  the  Andes  occurs  between  the  21st  and  15th 
Jegrees\)f  south  latitude.    It  includes  the  celebrated  mountain  of  Potosi,  situated  in 


196 


MINES. 


MINES. 


m 


iii'i 


11   !l 


LA' 
I 


11- 


nearly  the  20th  degree  of  south  latitude,  on  the  eastern  slope  of  the  chain,  and  stveral 
other  districts,  likewise  very  rich,  which  extend  principally  toward  the  northwest,  as 
far  as  the  two  banks  of  the  lake  Titicaca,  and  even  beyond  it,  through  a  total  length  of 
nearly  150  leagues.     All  these  districts,  which  formerly  depended  on  Peru,  were  united 
in  1778  to  the  government  of  Buenos  Ayres.     The  mines  of  Potosi  were  discovered  in 
1545,  and  have  famished  since  that  period  till  our  days,  a  body  of  silver  which  M.  Hum- 
boldt values  at  230,000,000Z.  sterling.     The  first  years  were  the  most  productive.     At 
that  time  ores  were  often  found  which  afforded  from  40  to  45  per  cent,  of  silver.   Since 
the  beginning  of  the  eighteenth  century,  the  average  richness  of  the  ore  does  not  exceed 
above  from  3  to  4  parts  in   10,000.     These  ores  are  therefore  very  poor  at  the  present 
day ;  they  have  diminished  in  richness  in  proportion  as  the  excavations  have  become 
deeper.     But  the  total  product  of  the  mines  has  not  diminished  in  the  same  propor- 
tion :  abundance  of  ore  having  made  up  for  its  poverty.    Hence,  if  the  mountain  of 
Potosi  is  not,  as  formerly,  the  richest  deposite  of  ore  in  the  world,  it  may,  however,  be 
still  placed  immediately  after  the  famous  vein  of  Guanaxuato.    The  ore  lies  in  veins  in 
a  primitive  clay  state,  which  composes  the  principal  mass  of  the  mountain,  and  is  cov- 
ered by  a  bed  of  clay  porphyry.     This  rock  crowns  the  summit,  giving  it  the  form  of  a 
basaltic  hill.     The  veins  are  very  numerous ;  several,  near  their  outcrop,  were  almost 
wholly  composed  of  sulphuret  of  silver,  antimoniated  sulphuret  of  silver,  and  native 
silver.    Others,  which  offered  near  the  surface  merely  sulphuret  of  tin,  became  richer 
as  they  descended.     In  1790,  seven  copper  mines  were  known  in  the  viceroyalty  of 
Buenos  Ayres,  seven  of  lead,  and  two  of  tin ;  the  last  being  merely  washings  of  sands 
feund  near  the  river  Oraro. 

On  the  opposite  flank  of  the  chain,  in  a  low,  desert  plain,  entirely  destitute  of  water, 
•which  adjoins  the  harbor  of  Iquiqua,  and  forms  a  part  of  Peru,  occur  the  silver  mines 
of  Huantajaya,  celebrated  for  the  immense  masses  of  native  silver  which  have  been 
sometimes  found  in  them.     In  1758,  one  was  discovered  weighing  eight  cwts. 

M.  Humboldt  quotes  40  cantons  of  Peru  as  being  at  the  present  day  most  famous 
for  their  subterranean  explorations  of  silver  and  gold.  Those  of  gold  are  found  in  the 
provinces  of  Huaailas  and  Pataz  ;  the  silver  is  chiefly  furnished  by  the  districts  of 
Huantajaya,  Pasca,  and  Chota,  which  far  surpass  the  others  in  the  abundance  of  their 

ores. 

The  silver  mines  of  the  district  of  Pasco  are  situated  about  30  or  40  leagues  north  of 
Lima,  in  10^  degrees  of  south  latitude,  4,400  yards  above  the  sea-level,  on  the  eastern 
slope  of  the  Cordilleras,  and  near  the  sources  of  the  river  Amazon.  They  were  dis- 
covered in  1630.  These  mines,  and  especially  those  of  Cero  of  Yauricocha,  are  actually 
the  richest  in  all  Peru.  The  ore  is  an  earthy  mass  of  a  red  color,  containing  much  iron, 
minded  with  particles  of  native  silver,  horn  silver,  &,c.,  constituting  what  they  call  Pacos. 
At  first,  nothing  but  these  pet co«  was  collected ;  and  much  gray  copper  and  antimoniated 
sulphuret  of  silver  were  thrown  among  the  rubbish.  The  mean  product  of  all  the  ores  is 

i_  _  ;  or  an  ounce  and  _2j_  per  cwt. ;  although  some  occur  which  yield  30  or  40  per 
cent.**  These  rich  deposites  do  not  seem  to  be  extended  to  a  great  depth  ;  they  have  not 
been  pursued  further  than  130  yards,  and  in  the  greater  part  of  the  workings  only  to 
from  35  to  45.  Forty  years  ago,  these  mines,  which  produced  nearly  2,000,000  of  pias- 
tres annually,  were  the  worst  worked  in  all  South  America.  The  soil  seemed  as  if 
riddled  with  an  immense  number  of  pits,  placed  without  any  order.  The  drainage  of 
the  waters  was  effected  by  the  manual  labor  of  men,  and  was  extremely  expensive.  In 
1816,  some  Europeans,  among  whom  were  several  miners  from  Cornwall,  mounted  sev- 
eral hish-pressure  steam-engines,  imported  from  England,  which  introduced  a  consid- 
erable improvement  in  the  workings. 

The  mines  of  the  province  of  Chota  are  situated  in  about  seven  degrees  of  south  lati- 
tude. The  principal  ones  are  those  of  Gualcayoc,  near  Mecuicampa,  discovered  in  1771 ; 
their  outcrop  occurs  at  the  height  of  4,500  yards  above  the  sea;  the  city  of  Mecuicampa 
itself  has  4,000  yards  of  elevation,  that  is,  higher  than  the  highest  summits  of  the  P>Te- 
nees.  The  climate  is  hence  very  cold  and  uncomfortable.  The  ore  is  a  mixture  of  sul- 
phuret of  silver  and  antimoniated  sulphuret,  with  native  silver.  It  constitutes  veins,  of 
which  the  upper  portion  is  formed  of  pacos,  and  they  sometimes  traverse  a  limestone 
and  sometimes  a  hornstone,  which  occurs  in  subordinate  beds.  The  annual  produce  of 
the  mines  is  67,000  marcs  of  silver,  according  to  Humboldt. 

In  the  districts  of  Huaailas  and  Pataz,  which  are  at  a  little  distance  from  the  former 
two,  gold  mines  are  worked.  This  metal  is  extracted  chiefly  from  the  veins  of  quartz, 
which  run  across  the  primitive  schistose  mountains.  The  district  of  Huaailas  contains, 
besides,  lead  mines.    Peru  possesses,  moreover,  some  mines  of  copper. 

The  quicksilver  mines  of  Huancavelica,  the  only  important  mine  of  this  species  which 
has  been  worked  in  the  New  World,  occurs  on  the  eastern  flank  of  the  Andes  of  Peru, 
in  13  degrees  of  south  latitude,  at  upward  of  6,000  yards  above  the  level  of  the  sea.  It 
does  not  seem  refeirible  to  the  same  class  of  deposites  with  the  mines  hitherto  mentioned. 


Indications  of  mercurial  acposites  have  been  observed  in  several  other  points  of  the  Andei 
of  Northern  Peru,  and  of  the  south  of  New  Granada. 

Lastly,  mines  of  sal-gem  are  known  to  exist  in  Peru,  especially  near  the  silver  mines 
of  Huantajaya. 

On  receding  from  the  district  of  Chota,  the  Cordilleras  are  very  indifferently  stored 
with  metallic  wealth,  to  the  isthmus  of  Panama,  and  even  far  beyond  it.  The  kingdom 
of  New  Granada  offers  but  a  very  small  number  of  silver  mines.  There  are  some  aurif- 
erous veins  in  the  province  of  Antioquia,  and  in  the  mountains  of  Guamoco.  The  prov- 
ince of  Caracas,  the  mountains  of  which  may  be  considered  as  a  ramification  of  the 
Cordilleras,  presents  at  Aroa  a  copper  mine  which  furnishes  annually  from  700  to  800 
metric  quintals  (1,400  to  1,600  cwt  )  of  this  metal.  Finally,  we  may  state  in  passing, 
that  there  is  a  very  abundant  salt  mine  at  Zipaquira,  in  the  province  of  Sante  Fe,  and 
that  between  this  point  and  the  province  of  Santa-Fe-de-Bogota,  a  stratum  of  coal  occurs 
at  the  extraordinary  height  of  2,700  yards. 

Although  Mexico  presents  a  great  variety  of  localities  of  ores,  almost  the  only  ones 
worked  are  those  of  silver.  Nearly  the  whole  of  these  mines  are  situated  on  the  back 
or  the  flanks  of  the  Cordilleras,  especially  to  the  west  of  the  chain,  nearly  at  the  height 
of  the  great  table  land  which  traverses  this  region  of  the  globe,  or  a  little  below  its 
level  in  the  chains  which  divide  it.  They  lie  in  general  between  2,000  and  3,000  yards 
above  the  sea ;  a  very  considerable  elevation,  which  is  favorable  to  their  prosperity, 
because  in  this  latitude  there  exists  at  that  height  a  mean  temperature,  mild,  salubrious, 
and  most  propitious  to  agriculture.  There  were  at  the  time  of  Humboldt's  visit,  from 
4,000  to  5,000  deposites  of  ore  exploited.  The  workings  constituted  3,000  distinct  mines, 
which  were  distributed  round  500  head  quarters  or  Reales.  These  mines  are  not,  how- 
ever, uniformly  spread  over  the  whole  extent  of  the  Cordilleras.  They  may  be  consid- 
ered as  forming  eight  groups,  which  altogether  do  not  include  a  greater  space  than 
12,000  square  leagues ;  viz.,  hardly  more  than  the  tenth  part  of  the  surface  of  Mexico. 

These  eight  groups  are,  in  proceeding  from  south  to  north, 

1.  The  group  of  Oazuaca,  situated  in  the  province  of  this  name  at  the  southern  extrem- 
ity of  Mexico  properly  so  called,  toward  the  17th  degree  of  north  latitude.  Besides 
silver  mines,  it  contains  the  only  veins  of  gold  explored  in  Mexico.  These  veins  trav- 
erse gneiss  and  mica-slate. 

2.  The  group  of  Tosco.  The  most  part  of  the  mines  which  compose  it  are  situated 
20  or  25  leagues  to  the  south  west  of  Mexico,  toward  the  western  slope  of  the  great 
plateau. 

3.  The  group  of  Biscania,  about  20  leagues  northeast  of  Mexico.  It  is  of  moderate 
extent,  but  it  comprehends  the  rich  workings  of  Pachuca,  Real  del  Monte,  and  Moram. 
The  district  of  Real  del  Monte  contains  only  a  single  principal  vein,  named  Veta  Bezi- 
cana  of  Real  del  Monte,  in  which  there  are  several  workings  ;  it  is,  however,  reckoned 
among  the  richest  of  Mexico. 

4.  The  group  of  Zimapan.  It  is  very  near  the  preceding,  about  40  leagues  north- 
west of  Mexico,  toward  the  eastern  slope  of  the  plateau.  Besides  numerous  sil  ver  mines, 
it  includes  abundant  deposites  of  lead,  and  some  mines  of  yellow  sulphuret  of  arsenic. 

5.  The  Central  group,  of  which  the  principal  point  is  Guanaxuato,  a  city  of  70,000  in- 
habitants, placed  at  its  southern  extremity,  and  60  leagues  N.  N.  W.  of  Mexico.  It 
comprises  among  others  the  famous  mine  districts  of  Gnanaxuato,  Catorce,  ZacaiecaSf 
Sombrerete ;  the  richest  in  Mexico,  and  which  alone  furnish  more  than  half  of  all  the 
silver  which  this  kingdom  brings  into  circulation. 

The  district  of  Guanaxuato  presents  only  one  main  vein,  called  the  Veta  Madre.  This 
vein  is  enclosed  principally  in  clay-state,  to  whose  beds  it  runs  parallel,  but  occasionally 
it  issues  out  of  them  to  intersect  more  modern  rocks.  The  vein  is  composed  of  quartz, 
carbonate  of  lime,  fragments  of  clay  slate,  &c. ;  and  includes  the  sulphurets  of  iron,  of 
lead,  and  of  zinc  in  great  quantities,  some  native  silver,  sulphuret  of  silver,  and  red 
silver  ;  its  power  (thickness  of  the  vein)  is  from  43  to  48  yards.  It  is  recognised  and 
worked  throughout  a  length  of  upward  of  13,000  yards;  and  contains  19  exploitations, 
which  produced  annually  well  on  to  1,200,000Z.  in  silver.  One  of  the  explorations,  that 
of  Valenciana,  produces  320,000/. ;  being  equal  to  about  one  fifteenth  of  the  total  prod- 
uct of  the  3,000  mines  of  Mexico.  Since  1764,  the  period  of  its  discovery,  its  neat 
annual  product  has  never  been  less  than  from  two  to  three  millions  of  francs  (80,000/. 
to  :20,000/.) ;  and  its  proprietors,  at  first  men  of  little  fortune,  became,  in  ten  years, 
the  richest  individuals  in  Mexico,  and  perhaps  in  the  whole  globe. 

The  workings  of  this  mine  are  very  extensive,  and  penetrate  to  a  depth  of  550  yards. 
They  employ  a  great  many  laborers. 

The  district  of  Zacatecas  presents  in  like  manner  only  a  single  vein  in  greywacke ; 
which,  however,  is  the  seat  oi  several  workings. 

The  deposites  mined  at  Catorce  are  in  limestone ;  the  mine  called  Punssima  dt  Catorce 
has  been  explored  to  about  650  yards  in  depth  ;  and  yielded,  in  1796,  nearly  20,00W 
There  are  also  mines  of  antimony  in  the  district  of  Catorce. 


198 


MINES. 


MINES. 


199 


II 


Toward  the  western  part  of  the  group  of  which  we  are  now  spealiing,  copper  minra 
are  worked  in  the  provinces  of  Valladolid  and  Guadalaxara ;  the  ores  being  chiefly  com- 
posed of  protoxide  of  copper  (orange  copper),  sulphuret  of  copper,  and  native  copper. 
These  mines  produce  about  2,000  metric  quintals  of  copper  annually  (440,000  lbs.  Lng- 
lish).  In  the  same  district,  ores  of  tin  are  collected  in  the  alluvial  soils,  particularly 
near  Mount  Gigante.  The  concretionary  oxide  of  tin,  so  rare  m  Europe,  is  here  the 
most  common  variety.     This  metal  occurs  also  in  veins.  . 

The  central  part  of  Mexico  contains  many  indications  of  sulphuret  of  mercury  (cin- 
nabar) ;  but  in  1804  it  was  worked  onlv  in  two  places,  and  to  an  inconsiderable  extent. 

6.  The  group  of  new  Gallicia  is  situated  in  the  province  of  this  name,  about  100  leagues 
N.  W.  from  Mexico.    It  comprises  the  mines  of  Balanos,  one  of  the  richest  districts. 

7  The  group  of  Durango  and  Sonora,  in  the  intendancies  of  the  same  name.  It  is 
very  extensive.  The  mines  are  situated  in  part  on  the  table  land,  and  in  part  on  the 
western  slope.     Durango  is  140  leagues  N.  N.  W.  of  Mexico.  .,     ,  j 

8  The  grcmp  of  Chinuahua.  It  takes  its  name  from  the  town  of  Chinuahua,  situated 
JOo'leagues  N.  of  Durango.  It  is  exceedingly  extensive,  but  of  little  value  ;  and  ter- 
minates at  29^  10'  of  north  latitude.  .    ,    .   .  •    .v     •  v       ««^;«« 

Mexico  possesses,  besides,  several  mines  which  are  not  included  in  the  eight  preceding 
groups.  Thus  the  new  kingdom  of  Leon,  and  the  province  of  New  Saint-Ander,  present 
abundant  mines  of  lead.    New  Mexico  contains  copper  mines,  and  many  others. 

Lastly,  rock  salt  is  mined  in  several  points  of  New  Spain  ;  and  coal  seems  to  occur  m 

New  Mexico.  ,     .        *         i  i 

The  richness  of  the  different  districts  of  the  silver  mines  or  reales  is  extremely  unequal. 
Nineteen  twentieths  of  these  reales  do  not  furnish  altogether  more  than  one  twellth  ot 
the  total  product.  This  inequality  is  owing  to  the  excessive  richness  of  some  deposites. 
The  ores  of  Mexico  are  principally  veins  ;  beds  and  masses  are  rare.  The  yems  traverse 
chieflv,  and  perhaps  only,  primitive  and  transition  rocks,  among  which  certain  porpnynes 
are  remarked  as  very  rich  in  deposites  of  gold  and  silver.  The  silver  ores  are  mostly 
sulphuret  of  silver,  black  antimoniated  sulphuret  of  silver,  muriate  of  silver  (hornsilver), 
and  gray  copper.  Many  explorations  are  carried  on  in  certain  earthy  ores,  called 
coUorados,  similar  to  the  pacos  of  Peru.  Lastly,  there  are  ores  of  other  metals,  which 
are  worked  principally,  and  sometimes  exclusively,  for  the  silver  which  they  contain; 
such  are  the  argentiferous  sulphuret  of  lead,  argentiferous  sulphuret  of  copper,  and 
argentiferous  sulphuret  of  iron.  ,  n  *     a 

Ores  of  very  great  richness  occur  in  Mexico;  but  the  average  is  only  trom  3  to  4 
ounces  per  cwt.,  or  from  18  to  25  in  10,000.  There  are  some,  indeed,  whose  estimate 
does  not  exceed  2l  ounces.  Almost  all  the  argentiferous  veins  affoi^d  a  little  gold  ;  the 
silver  of  Guanaxuato,  for  example,  contains  ^  .  The  enormous  product  of  the  Mexican 
mines  is  to  be  ascribed  rather  to  the  great  facility  of  working  them,  and  the  abundance 
of  ores,  than  to  their  intrinsic  richness.  •  j    r  ti     v  i^*>- 

The  art  of  mining  was  little  advanced  in  this  country  at  the  period  of  Humboldt  s 
journey;  the  workings  presented  a  combination  of  small  mines,  each  of  which  had  only 
one  aperture  above,  without  any  lateral  communications  between  the  ditlerentsha  ts. 

The  form  of  these  explorations  was  too  irregular  to  admit  of  their  being  called  workings 
bv  steps.  The  shafts  and  the  galleries  were  much  too  wide.  The  interior  transport  of  the 
ores  is  generally  effected  on  the  back  of  men ;  rarely  by  mules.  The  machines  for  raising 
the  ore  and  drawing  off  the  water  are  in  general  ill  combined  ;  and  the  horse  gigs  for 
settin''  them  in  motion  ill  constructed.  The  timbering  of  the  shafts  is  very  imperfectly 
executed ;  the  walled  portions  alone  are  weU  done.  There  are  some  galleries  of  drainage, 
but  thev  are  too  few,  and  ill  directed.  Latterly,  English  capitalists  and  miners  have 
formed  companies  for  working  the  silver  mines  of  Mexico ;  which  will  probably  produce 

in  time  a  happy  revolution.  ,    ,     i.    •  »       *i    v         -i 

The  silver  ores  of  Spanish  America  are  treated  partly  by  fusion,  and  partly  by  amal- 
iramation,  but  more  frequently  by  the  latter  mode;  hence  the  importation  of  mercury 
forms  there  an  object  of  the  highest  importance,  especially  since  the  quicksilver  mine  of 
Huar^cavelica  fell  in,  and  ceased  to  be  worked.  This  mine  is  the  only  one  in  bpanish 
America  which  belongs  to  the  government.    For  the  modern  state  of  these  mines,  sec 

The  following  table  shows,  accordina;  to  M.  de  Humboldt,  what  was  the  annual  prod- 
uct of  the  silver  mines  of  South  America,  at  the  beginning  of  this  century.  It  is 
bounded  in  a  great  measure,  upon  official  documents  : — 


Mexico 
Peru    - 
Buenos-Ayres 
ChQi   - 

Total  - 


2,196,140  marcs,  or  537,512  kil.,  worth  £4,778,000 

573,958  140,478  1,250,000 

463,098  110,764  984,600 

25957  6,827  60,680 


-     3,259,153 


795,581 


7,073,280 


To  complete  our  picture  of  the  mineral  wealth  of  Spanish  America,  it  remains  to 
speak  of  its  principal  gold  mines ;  ^ut  these  belong  to  a  geological  locality,  alluvial  sands 
and  gravel,  very  different  from  that  of  our  present  objects.  The  most  important  of  these 
gold  sands  are  washed  on  the  western  slope  of  the  Cordilleras ;  viz.,  in  New  Grenada, 
from  the  province  of  Barbacoas,  to  the  isthmus  of  Panama,  to  Chili,  and  even  to  the 
shores  of  the  seas  of  California.  There  are  likewise  some  on  the  eastern  slope  of  the 
Cordilleras,  in  the  high  valley  of  the  river  Ajnazons.  The  washings  of  New  Granada 
produce  also  some  platina. 

The  mines,  properly  so  called,  and  the  washings  of  South  America,  furnish,  altogether, 
42,575  marcs,  or  10,418  kilogrammes  (22,920  libs.  Eng.)  of  gold,  worth  1,435,720/. 

MINES  OF  HUNGARY. 

The  metallic  mines  of  this  kingdom,  including  those  of  Transylvania,  and  the  Bannat 
of  Temeschwar,  form  four  principal  groups,  which  we  shall  denote  by  the  group  of  the 
N.W.,  group  of  the  N.E.,  group  of  the  E.,  and  group  of  the  S.E. 

The  group  of  the  N.W.  embraces  the  districts  of  Schemnitz,  Kremnitz,  Kcenigsberg, 
Neuhsohl,  and  the  environs  of  Schmoelnitz,  Bethler,  Rosenau,  &c. 

Schemnitz,  a  royal  free  city  of  mines,  and  the  principal  centre  of  the  mines  of  Hun- 
gary, lies  25  leagues  to  the  north  of  Buda,  560  yards  above  the  sea,  in  the  midst  of  a 
small  group  of  mountains  covered  with  forests.  The  most  part  of  these  mountains,  the 
highest  of  which  reaches  an  elevation  of  1,130  yards  above  the  ocean,  are  formed  of 
barren  trachytes  (rough  trap  rocks)  ;  but  at  their  foot  below  the  trachytic  formation, 
a  formation  is  observed,  consisting  of  green-stone  porphyries,  connected  with  syenites, 
passing  into  granite  and  gneiss,  and  including  subordinate  beds  of  mica-slate  and  lime- 
stone.    It  is  in  this  formation  that  all  the  mines  occur. 

It  has  been  long  known  that  the  green-stone  porphyries  of  Schemnitz  have  intimate 
relations  with  the  metalliferous  porphyries  of  South  America.  M.  Beudant,  on  com- 
paring them  with  those  brought  by  M.  de  Humboldt  from  Guanaxuato,  Real  del  Monte, 
&c.,  has  recognised  an  identity  in  the  minutest  details  of  color,  structure,  composition, 
respectiv^e  situation  of  the  different  varieties,  and  even  in  the  empirical  character  of 
effervescence  with  acids.  The  metalliferous  rocks  appear  at  Schemnitz  only  in  a  space 
of  small  extent,  comprehended  partly  in  a  small  basin,  of  which  the  city  occupies  the 
south  border.  They  are  traversed  by  veins  which,  for  the  most  part,  cut  across  the  strati- 
fication, but  which  also  are  sometimes  obviously  parallel  to  it.  These  veins  are  in 
general  very  powerful ;  their  thickness  amounting  even  to  more  than  40  yards,  but  their 
extent  in  length  seems  to  be  usually  inconsiderable.  They  are  numerous  and  parallel 
to  each  other.  It  appears  that  they  have  no  side  plates  of  vein-stones  (sallebandes),  but 
that  the  metalliferous  mass  reposes  immediately  on  the  cheeks  or  sections  of  the  rock, 
which  is  usually  more  or  less  altered,  and  includes  always  much  pyrites  near  the  point 
of  contact,  and  even  to  a  distance  of  several  feet.  The  substances  which  constitute  the 
body  of  these  veins,  are  drusy  quartz,  carious  quartz,  ferriferous  carbonate  of  lime,  and 
sulphate  of  barytes,  with  which  occur  sulphuret  of  silver  mixed  with  native  silver 
containing  more  or  less  gold,  which  is  rarely  in  visible  scales ;  sulphuret  of  silver,  argen- 
tiferous galena,  blende,  copper  and  iron  pyrites,  &c.  The  sulphuret  of  silver  and  the 
galena  are  the  two  most  important  ores.  Sometimes  these  two  substances  are  insulated, 
sometimes  they  are  mixed  in  different  manners  so  as  td  furnish  ores  of  every  degree  of 
richness,  from  such  as  yield  60  per  cent,  of  silver  down  to  the  poorest  galena.  The  gold 
seldom  occurs  alone;  it  generally  accompanies  the  silver  in  a  very  variable  proportion, 
which  most  usually  approaches  to  that  of  1  to  30. 

The  ores  of  Schemnitz  are  all  treated  by  fusion ;  the  poor  galenas  at  the  smelting 
house  of  Schemnitz  (bleyhutte),  and  the  resulting  lead  is  sent  as  working  lead  to  the 
smelting-houses  of  Kremnitz,  Neusohl,  and  Schernowitz,  whither  all  the  silver  ores 
prepared  in  the  different  spots  of  the  country  are  transported  in  order  to  be  smelted. 

The  mines  of  Schemnitz,  opened  800  years  ago,  have  been  worked  to  a  depth  of  more 
than  350  yards.  The  explorations  are  in  general  well  conducted.  Excellent  galleries 
of  efflux  have  been  excavated ;  the  waters  for  impulsion  are  collected  and  applied 
with  skill.  It  may  be  remarked,  however,  that  these  mines  begin  to  decline  from  the 
state  of  prosperity  in  which  they  stood  several  years  ago ;  a  circumstance  to  be  ascribed 
probably  to  the  same  pains  being  no  longer  bestowed  on  the  instruction  of  the  officers 
appointed  to  superintend  them.  Maria  Theresa  established  in  1760,  at  Schemnitz,  a 
school  of  mines.  This  acquired  at  its  origin,  throughout  Europe,  a  great  celebrity, 
which  it  has  not  been  able  to  maintain. 

Kremnitz  lies  about  five  leagues  N.N.W.  of  Schemnitz,  in  a  valley  flanked  on  the 
right  by  a  range  of  hills  formed  of  rocks  quite  analogous  to  the  metalliferous  rocks  of 
Schemnitz.  In  the  midst  of  these  rocks,  veins  are  worked  nearly  similar  to  those  of 
Schemnitz  ;  but  the  quartz  which  forms  their  principal  mass  is  more  abundant,  and  con- 
tains more  native  gold.    Here  also  are  found  sulphuret  and  hydrosulphuret  oi  antimony^ 


200 


MINES. 


MINES. 


t ' 


vhich  do  not  occar  at  Schemnitz.  The  metalliferous  district  is  of  very  moderate  extent, 
and  is  surrounded  by  the  trachytic  district  which  overlies  it,  forming  to  the  cast  and 
west  considerable  mountains. 

The  city  of  Kremnitz  is  one  of  the  most  ancient  free  royal  cities  of  mines  in  Hun- 
gary. It  is  said  that  mines  were  worked  there  even  in  the  times  of  the  Romans ;  but 
it  is  the  Germans  who,  since  the  middle  ages,  have  given  a  great  development  to  these 
exploitations.  There  exists  at  Kremnitz  a  mint-office,  to  which  all  the  gold  and  silver 
of  the  mines  of  Hungary  are  carried  in  order  to  be  parted,  and  where  all  the  chemical 
processes,  such  as  the  fabrication  of  acids,  &c.,  are  carried  on  in  the  large  way. 

About  six  leagues  N.N.E.  from  Schemnitz,  on  the  banks  of  the  Gran,  lies  the  little 
village  o(  Neusohl,  founded  by  a  colony  of  Saxon  miners.  The  mountains  surrounding 
it  include  mines  very  different  from  those  of  which  we  have  been  treating.  At  Herren- 
grand,  two  leagues  from  Neusohl,  grey  wacke  forms  pretty  lofty  mountains  ;  this  rock  is 
covered  by  transition  limestone,  and  is  supported  by  mica-slate.  The  lower  beds  con- 
tarn  bands  of  copper  ores,  chiefly  copper  pyrites.  The  mica-slate  includes  likewise 
masses  of  ore,  apparently  constituting  veins  in  it.  These  ores  have  been  worked  since 
the  13th  century.  The  copper  extracted  contains  in  a  hundred  weight  six  ounces  ol 
silver. 

Eighteen  or  twenty  leagues  to  the  east  of  Neusohl,  we  meet  with  a  country  very  rich 
in  iron  and  copper  mines,  situated  chiefly  in  the  neighborhood  of  Bethler,  Schmoelnitz, 
Einsiedael,  Rosenau,  &,c.  Talcose  and  clay  slates  form  the  principal  body  of  the  moun- 
tains here,  along  with  horneblende  rocks.  The  ores  occur  most  usually  in  strata.  Those 
of  iron,  or  sparry  ore,  and  especially  hydrate  of  iron,  compact  and  in  concretions,  ac- 
companied with  specular  iron  ore.  They  give  employment  to  a  great  many  large 
smelting-houses.  The  county  of  Goemar  alone  contains  22  works;  and  that  of  Zips 
also  a  great  number.  The  copper  mines  lie  chiefly  in  the  neighborhood  of  Schmoelnitz 
and  Gcelnitz.  The  copper  extracted  contains  about  six  or  seven  ounces  of  silver  in  the 
hundred  weight.  Near  Zalathna  there  is  a  quicksilver  mine  nearly  inactive;  and  near 
Rosenau  one  of  antimony. 

To  conclude  our  enumeration  of  the  mineral  wealth  of  this  country,  it  remains  merely 
to  state  that  there  are  opal  mines  in  the  environs  of  Czervenitza,  placed  in  the  trachytic 
conglomerate. 

GROUP  OF  THE  NORTHEAST,  OR  OF  NAGABANYA. 

The  mines  of  this  group  lie  in  a  somewhat  considerable  chain  of  mountains,  which, 
proceedmg  from  the  frontiers  of  Buchowina,  where  it  is  united  to  the  Carpathians,  finally 
disappears  amid  the  saliferous  sandstones  between  the  TAem,  iapoj,  and  Nagy  Szamos, 
on  the  northern  frontiers  of  Transylvania.  These  mountains  are  partly  composed  of 
rocks  analogous  to  those  of  Schemnitz,  traversed  by  veins  which  have  much  resemblance 
to  the  veins  of  this  celebrated  spot.  Into  these  veins  a  great  many  mines  have  been 
opened,  the  most  important  of  which  are  those  of  Nagabanya,  Kapnick,  Felsobanya, 
Miszbanya,  Laposbanya,  Olaposbanya,  Ohlalapos.  All  these  mines  produce  eold.  Those 
ofLaposbanya  furnish,  likewise,  argentiferous  galena;  those  of  Olaposbanya  contain 
copper  and  iron  ;  and  those  of  Kapnick  copper.  Realgar  occurs  in  the  mines  of  Felso- 
banya ;  and  orpiment  in  those  of  Ohlalapos.  Several  of  them  produce  manganese  and 
sulphuret  of  antimony.  Lastly,  toward  the  north,  in  the  county  of  Marmarosh,  lies 
the  important  iron  mine  of  Borscha,  and  on  the  frontiers  of  Buchowina  the  lead  mine 
of  Radna,  in  which  also  much  zinc  ore  occurs. 

The  mines  composing  the  group  of  the  East,  or  of  Jbrudbanya,  occur  almost  all  in  the 
mountains  which  rise  in  the  western  part  of  Transylvania,  between  Zapo*  and  Maros,  in 
the  environs  of  Mrudbanya.  M.  Beudant  notices  in  this  region,  limestones,  sandstones, 
trachytes,  basalts,  and  sienite  porphyries,  apparently  quite  analogous  to  the  greenstone 
porphyries  of  Schemnitz.  It  seems  to  be  principally  in  the  latter  rocks  that  the  mines 
forming  the  wealth  of  this  country  occur  ;  but  some  of  them  exist  also  in  the  mica- 
slate,  the  greywacke,  and  even  in  the  limestone.  The  principal  mines  are  at  Nagyao 
Koiosbanya,  Vorospatak,  Boitza,  Csertesch,  Fatzbay,  Almas,  Porkura,  Butschum,  and 
Stonischa.  There  are,  in  all,  40  exploitations;  the  whole  of  which  produce  auriferous 
ores  smelted  at  the  foundry  of  Zalathna.  These  mines  contain  also  copper,  antimonv 
and  manganese.  They  are  celebrated  for  their  tellurium  ore,  which  was  peculiar  to  them 
prior  to  the  discovery  of  this  metal  a  few  years  back  in  Norway.  The  auriferous  de- 
posites  contained  in  the  greenstone  porphyry  are  often  very  irregular.  The  mines  of 
Nagyag  are  the  richest  and  best  worked.  The  numerous  veins  occur  partly  in  the 
sienite  porphyry,  and  partly  in  the  greywacke.  The  auriferous  ore  is  accompanied  with 
galena,  realgar,  manganese,  iron,  and  zinc.  There  are  iron  mines  in  great  beds  near 
Vayda-Huniad  and  Gyalar.     Some  Cobalt  mines  are  also  noticed. 

The  group  of  the  S.  E.,  or  of  the  Bannat  of  Temeschwar,  occurs  in  the  mountains  which 
block  up  the  valley  of  the  Danube  at  Orschova,  through  a  narrow  gorge  of  which  the 
river  escapes.    The  principal  mines  are  at  Oravitza,  Moldawa,  Szaska,  and  Dognaaczka 


201 


They  produce  chiefly  argentiferous  copper,  yielding  a  marc  of  sUver  (nearly  \  pounds 
in  the  hundred  weight,  with  occasionally  a  little  gold.  Ores  of  lead,  zinc,  and  iron, 
are  also  met  with.  The  mines  are  famous  for  their  beautiful  specimens  of  blue  car' 
bonate  of  copper,  and  various  other  minerals.  The  mine  of  Moldawa  aiibrds  likewise 
orpiment.  These  metallic  deposites  lie  in  beds  and  veins  ;  the  former  occurring'  par- 
ticularly  between  the  mica-slate  and  the  limestone,  or  sometimes  between  the  limestone 
and  the  sienite  porphyry.  Well-defined  veins  also  are  known  to  exist  in  the  sienite 
and  the  mica-slate.  The  Bannat  possesses  moreover  important  iron-mines  at  Dom- 
trawa  and  Ruchersberg;  near  Dombrawa  sulphuret  of  mercury  is  found.  Cobalt 
minrs  occur  likewise  in  these  regions. 

1  he  mines  constituting  the  four  groups  now  described  are  not  the  sole  metallic 
mines  possessed  by  Hungary.     A  few  others,  but  generally  of  little  importance,  are 
scattered   over  diflerent  parts  of  this  kmgdom.     Several  have  been  noticed  in  the 
portion  of  the  Carpathians  which  separates  Transylvania  from  Moldavia  and  Wallachia 
Their  principal  object  is  the  exploration  of  some  singular  deposites  of  galena 

Besides  the  mines  just  noticed,  Hungary  contains  some  coal  mines,  numerous  mines 
of  rock  salt,  and  several  deposites  of  golden  sands  situafed  chiefly  on  the  banks  of  thi. 
Danube,  the  Marosch,  and  the  Nera. 

The  mines  of  the  kingdom  of  Hungary  produce  annually,  according  to  M.  Heron  de 

L'^i^n''^'  ^*^^^  J'i'S  ''''  ^'V^  r^,''^'  ^"»^^'^  ""^  §^°^^>  '^^o^th  175,976/. ;  and  about 
85,000  marcs,  or  45,707  pounds  of  silver,  worth  186,132/.  The  mines  of  Transylvania 
furnish  nearly  the  half  of  the  whole  quantity  of  gold,  and  one  seventeenth  of  the  sUver 
now  stated.  The  other  mines  of  Europe  produce  together  nearly  twice  as  much  silver 
but  merely  a  few  marcs  of  gold.  Hungary  aflfords  besides  from  18,000  to  20  000 
metric  quintals  (about  4,000,000  libs.  English)  of  copper  annually,  and  a  great  deal 

s^I^^^.  these  mines  proceed  likewise  from  3,000  to  4,000  metric  quintals  (660,000  to 
880,000  hbs.  Eng.)  of  lead ;  a  quantity  not  more  than  is  neefled  by  the  refining-houses 
for  the  ores  of  silver  and  gold.  " 

MINES   OF   THE   ALTAYAN   MOUNTAINS. 

^tr-  ^^l  ^^^nU"  extremity  of  the  chain  of  the  Altayan  mountains,  which  separate 
Siberia  from  Chinese  Tartary,  there  exists  a  number  of  metalliferous  veins,  in  which 
several  important  works  have  been  established  since  the  year  1742.  They  constitute 
the  locality  of  the  mines  of  Kolywan;  the  richest  in  the  precious  metals  of  the  three 
districts  of  this  kind  existing  m  Siberia. 

These  mines  are  opened  up  in  the  schistose  formations  which  surround  to  the  N.  and 
W.  and  to  the  S.  VV.  the  western  declivity  of  the  high  granitic  chain,  from  which  they  are 
separated  by  formations  consisting  of  other  primitive  rocks.  These  schists  alternate  in 
some  points  with  quartzose  rocks,  called  by  M.  Renovantz  hornstone,  and  with  lime- 
stone. They  are  covered  by  a  limestone,  replete  with  ammonites.  The  metalliferous 
region  forms  a  semicircle,  of  which  the  first  lofty  mountains  occupy  the  centre 

The  most  important  exploration  of  this  country  is  the  silver  mine  of  Zmeof  or 
Zmeinogarsk,  m  German  Schlan?enberg,  situated  to  the  N.W.  of  the  hi'^h  mountainq 
m  5IO   9;  25'  N.  L.  and  79°  49' 50"  long,  east   of  Paris.     It   is  opened   on  a  gr^t 
vein,  which  contains  argentiferous  native  gold,  auriferous  native  silver,  sulphuret  of 
silver,  hornsilver,  gray  copper,  sulphuret  of  copper,  green  and  blue  carbonated  copper, 
red  oxide  of  copper,  copper  pyrites,  sulphuret  of  lead,  and  great  masses  of  testaceous 
arsenic  slightly  argentiferous.     There  occur  likewise  sulphuret  of  zinc,  iron  mrit^    , 
and  sometimes  arsenical  pyrites.     The  gangues  (vein-stones)  of  these  different  o^ls  are 
sulphate  of  baryta,  carbonate  of  lime,  quartz,  but  rarely  fluate  of  Ih^e      The  pr^cinal 
vein,  which  IS  of  great  power,  has  been  traced  through  a  lengtliT  several  hTndred 
fathoms,  and  to  a  depth  of  no  less  than  96  fathoms.     In  its  superior  portion  it  has  an 
nclmation  of  about  50  degrees;  but  lower  down  it  becomes  nearTvmSl      Its  roof 
IS  always  formed  of  clay-slate.     On  the  floor  of  the  vein,  the  slate  altlmates  with  horn 
stone.     This  vein  pushes  out  branches  in  several  directions;  it  is  fn  rrsected  by ^^^ 

mrt'prot?tTv:"'Vh"'^r:f"  ^'^"^^  ^'  '"f^^^l^  "^'"^^^-     '^^^  firs^Tears  we' e""« 
mosi  proauctive.     The  German  miners  employed  subsequently  by  the  Russian  <rnvprn 

paJofskTt  LXers  P*"'";  °i^"  ^il^f  ■"'""?  "/""'^  department  are  those  of  Tchere- 
panoisui,  d  leazucs  S.E.  of  Zmeof;  those  of  Smenofski,  10  lea-ues  S  E  •  those  of 

f«rephc';     T  eZtU"  ','*=  '•'•.^•'    "■"•  °f  P'-I^Po'-^ki,  90  league,  slt^tftfe 
same  place.     1  he  last  mine  lies  on  the  extreme  front  er  of  Chinese  Tartarv      It  is  not 

^"ntZs^rauUrourd'eXt-^  "  "^  ^"^'^  ""'"  -""'"  «"=  C^^i- -.erlJ.re^! 
The  ores  extracted  from  these  diflereat  mines  yield  on  an  average  per  quiatal  an 


202 


MINES. 


ttt 


I 


IMC 


ounce  of  silver,  which  contains  3  per  cent,  of  gold.  Their  annual  product  was  toward 
178H,  according  to  M.  Patrin,  3,000  marcs,  or  1,615  libs,  avoirdupois  of  gold,  worth 
101,151/. ;  and  60,000  marcs,  or  31,020  libs,  avoird.  or  silver,  worth  130,520/. 

The  precious  metals  are  not  the  sole  product  of  this  mineral  district.  There  is  an 
important  copper-mine  15  leagues  N.W.  of  Zmeof,  in  a  chain  of  hills  formed  of  gra- 
nitic rocks,  schists,  porphyries,  and  shell-limestone,  graduating  into  the  plain.  The 
vein  presents  copper  pyrites,  sulphuret  of  copper,  and  native  copper,  disseminated  in 
argillaceous  substances,  more  or  less  ferruginous,  and  of  different  degrees  of  hardness. 
This  mine,  which  bears  the  name  of  Aleiski-Loktefski,  furnished  annually  at  the  date 
of  1782,  1,500  quintals  (metric),  or  330,000  libs,  avoird.  of  copper,  which  was  coined 
into  money  in  the  country  itself. 

At  Tchakirskoy,  on  the  banks  of  the  Tscharlsch,  toward  the  northern  extremity  of 
the  metalliferous  semicircle,  mentioned  above,  there  is  a  mine  of  argentiferous  copper 
and  lead,  opened  in  a  very  large  but  extremely  short  vein.  Besides  the  lead  and 
copper  ores,  including  a  little  silver,  this  mine  affords  a  grent  quantity  of  calamine 
(carbonate  of  zinc),  which  forms  occasionally  fine  stalactites  of  a  white  or  green  color. 

The  northern  flank  of  the  Altai  mountains  presents  few  mines.  Some  veins  of 
copper  exist  2,000  leagues  east  of  Zmeof,  near  the  spot  where  the  river  Janissei  issues 
from  the  Saianean  mountains,  which  are  a  prolongation  of  the  Altayan  chain. 

There  is  no  lead-mine,  properly  so  called,  in  the  Altai  mountains.  Almost  all  the 
lead  which  is  required  for  the  treatment  of  the  silver  and  gold  ores  is  obtained  from  the 
department  of  Nertchinsk,  situated  700  leagues  oft',  on  the  borders  of  the  river  Amour. 

The  first  smelting-house  erected  in  this  district  was  in  the  middle  of  the  metalliferous 
region  at  Kolywan,  the  place  from  which  it  takes  its  name.  It  has  been  suppressed  on 
account  of  the  dearth  of  wood  in  the  neighborhood  of  the  mines.  The  principal  exist- 
ing foundry  it  that  of  Bornaoul  on  the  Ob,  50  leagues  north  of  Zmeof. 

MINES   OF   THE   URAL    MOUNTAINS. 

This  chain  of  mountains,  which  begins  on  the  coasts  of  the  icy  sea,  and  terminates 
in  the  50th  degree  of  latitude  amid  the  steppes  of  the  Kerguis,  after  having  formed, 
through  an  extent  of  more  than  40  leagues,  the  natural  limit  between  Europe  and 
Asia,  contains  very  rich  and  very  remarkable  deposites  of  metallic  ores,  which  have 
given  rise  to  important  mines  of  iron,  copper,  and  gold.  These  explorations  are 
situated  on  the  two  slopes,  but  chiefly  on  the  one  that  looks  to  Asia,  from  the  environs 
of  Ekaterinbourg  to  about  120  or  130  leagues  north  uf  thai  city.  They  constitute  the 
department  of  the  mines  of  Ekaterinbourg,  one  of  the  three  belonging  to  Siberia. 

The  copper-mines  are  pretty  numerous,  and  lie  almost  wholly  on  the  oriental  slope 
of  the  chain.  They  are  opened  into  veins  of  a  very  peculiar  nature,  and  which  although 
very  powerful  at  the  surface,  do  not  extend  to  any  considerable  depth.  These  veins 
are  in  general  filled  with  argillaceous  matters,  penetrated  with  red  oxide  of  copper,  and 
mingled  with  green  and  blue  carbonated  copper,  sulphuret  of  copper,  and  native  copper. 
The  most  important  workings  are  those  of  Tourinski  and  Goiimechafski. 

The  first  are  situated  120  leagues  north  of  Ekaterinbourg,  toward  the  60th  degree 
of  N.  latitude,  at  the  eastern  base  of  the  Uralian  mountains,  near  the  banks  of  the  Touria. 
They  amount  to  three,  opened  in  the  same  vein,  which  turns  round  an  angle  presented 
by  the  chain  in  this  place.  The  ground  is  composed  of  a  porphyry  with  a  hornstone 
basis  of  clay-slate,  and  of  a  white  or  grayish  limestone,  which  form  the  roof  and  floor 
of  the  vein.  The  ore  yields  from  18  to  20  per  cent.,  and  these  mines  produced  annually 
in  1786,  10,000  metric  quintals  (2,200,000  libs,  avoird.)  of  copper. 

The  mine  of  Goumechefski  lies  12  or  15  leagues  S.W.  of  Ekaterinbourg,  near  a 
lake  bordered  by  primitive  mountains,  which  form  in  this  region  the  axis  of  the  chain 
of  the  Urals.  This  mine  is  celebrated  for  the  beautiful  malachites  that  occur  in  it. 
It  has  furnished  almost  all  the  fine  specimens  of  this  substance  employed  in  jewellery. 
The  vein,  of  which  the  sides  are  calcareous,  is  vertical,  and  runs  north  and  south. 
It  does  not  sink  deeper  than  about  50  yards,  and  is  filled  with  a  species  of  coarse, 
pudding-stone,  composed  of  masses  of  primitive  rocks.  The  ore  yields  from  3  to  4 
per  cent,  of  copper,  and  the  mine  furnished  about  the  year  1786,  4,400,000  libs,  avoird. 
of  this  metal  -per  annum. 

The  beds  of  iron  ore  occur  generally  at  a  certain  distance  from  the  axis  of  the 
central  chain.  Those  of  the  western  slope  lie  sometimes  in  a  gray  compact  limestone^ 
which  contains  entrochi  and  other  petrifications,  and  whose  geological  age  has  not  been 
ascertained,  but  it  appears  to  be  much  more  modern  than  the  rocks  of  the  central  chain. 
Both  the  one  and  the  other  seem  to  form  large  veins,  which  extend  little  in  depth,  or 
rather  fill  irregular  and  shallow  cavities.  The  most  common  ore  is  the  hydrate  of  iron 
(bog  ore),  hematite,  or  compact  iron  ore,  sometimes  mixed  or  accompanied  with  hydrate 
of  manganese,  and  occasionally  with  ores  of  zinc,  copper,  and  lead.  Black  oxid% 
of  iron,  possessing  magnetic  polarity,  likewise  frequently  occurs,  particularly  in  the 


MINES. 


203 


mines  of  the  eastern  slope,  on  which,  in  fact,  entire  mountains  of  loadstone  repose.  All 
these  ores,  mixed  with  a  greater  or  less  quantity  of  clay  differently  colored,  are 
worked  by  open  quarries,  and  most  usuafly  without  using  gunpowder,  or  even  iron 
wedges.  They  yield  rarely  less  than  50  or  60  per  cent.,  and  keep  in  action  numerous 
smeiling-houses  situated  on  the  two  flanks  of  the  chain ;  the  oldest  of  them  have  been 
established  since  1628,  but  the  greater  number  date  only  from  the  middle  of  the  I8th 
century.  The  most  celebrated  mines  are  those  of  Balgodat  and  Keskanar,  situated  on 
the  eastern  slope  from  30  to  50  leagues  north  of  Ekaterinbourg.  In  the  foundries  of 
the  eastern  slope,  anchors,  cannons,  bullets,  &c.,  are  fabricated ;  and  in  the  whole  a 
considerable  quantity  of  bar  iron.  The  products  of  the  works  on  the  western  side  are 
directly  embarked  on  the  different  feeders  of  the  Volga,  from  which  they  are  at  no 
great  distance.  Those  of  the  eastern  slope  are  transported  during  winter  on  sled<'es  to 
the  same  feeder  streams,  after  crossing  the  least  elevated  passages  of  the  Urals.  ° 

The  quantity  of  materials  fabricated  by  the  iron-works  of  both  slopes,  amounted 
annually,  toward  the  year  1790,  to  more  than  11,000,000  lbs.  avoird.  This  country 
IS  peculiarly  favored  by  nature  for  this  species  of  industry  ;  for  vast  deposites  of  excel- 
lent iron  ores  occur  surrounded  by  immense  forests  of  firs,  pines,  and  birches;  woods, 
whose  charcoal  is  excellently  adapted  to  the  fabrication  of  iron. 

The  copper-mines  of  the  Uralian  mountains,  and  the  greater  part  of  the  iron  mines 
and  foundries,  form  a  portion  of  the  properties  of  some  individuals,  who  may  be  in- 
stanced as  among  the  richest  in  Europe.  The  Russian  government  has  neglected  no 
opportunity  of  promoting  these  enterprises.  It  has  established  at  Tourinsky  a  consid- 
erable colony,  and  at  Irbitz  a  fair  which  has  become  celebrated. 

There  is  only  one  gold  mine  in  the  Ural  mountains,  that  of  Beresof,  situated  three 
leagues  N.E.  of  Elkaterinbourg,  at  the  foot  of  the  Urals,  on  the  Asiatic  side.     It  is 
tamous  for  the  chromate  of  lead,  or  red  lead  ore,  discovered  there  in  1776,  and  worked 
m  the  following  years,  as  also  for  some  rare  varieties  of  minerals.    The  ore  of  Beresof 
is  a  cavernous  hydrate  of  iron  (bog  ore),  presenting  here  and  there  some  smaU  striated 
^"i  I  ^     in  f^^^**^  *^°"'  ^^^  occasionally  some  pyrites.    It  contains  5  parts  of  native 
gold  m  100,000.    This  deposite  appears  to  have  a  great  analogy  with  the  deposites  of 
iron  ore  of  the  same  region.     It  constitutes  a  large  vein,  funning  from  N.  to  S., 
encased  in  a  formation  of  gneiss,  hornblende  schists,  and  serpentine,  and  which  does  not 
appear  to  dip  to  any  considerable  depth.     It  becomes  poor  in  proportion  to  its  distance 
Irom  the  surface.    The  exploitation,  which  is  in  the  open  air,  has  dug  down  25  vards: 
having  been  carried  on  since  the  year  1726.     The  gold  is  extracted  from  the  ore  by 
stamping  and  washing.     In  1786,  500  marcs  were  collected;  but  the  preceding  years 
had  furnished  only  200,  because  they  then  worked  further  from  the  surface.     German 
miners  were  called  in  to  direct  the  operations.     On  some  points  of  the  Ural  mountains, 
and  the  neighboring  countries,  deposites  of  an  auriferous  clay  have  been  noticed :  but 
they  have  not  hitherto  been  worked. 
Beds  of  chromate  of  iron  have  also  been  discovered  in  these  mountains. 
Ihe  beautiful  plates  of  mica,  well  known  in  mineral  cabinets,  and  even  in  commerce, 
under  the  name  of  Muscovy  talc,  or  Russian  mica,  come  from  the  Urals.     There  are 
explorations  for  them  near  the  lake  Tschebarkoul,  on  the  eastern  flank  of  this  chain. 
J?rom  the  same  canton  there  is  exported  a  very  white  clay,  apparently  a  kaolin. 

25  leagues  north  of  Ekaterinbourg,  near  the  town  of  Mourzinsk,  there  occur  in  a 
graphic  granite,  numerous  veins,  containing  amethysts,  several  varieties  of  beryl,  emer- 
alds, topazes,  &c. 

Table  of  the  Production  of  the  Russian  Mines  during  the  years  1830, 1831,  1832,  1833, 

and  1834 ;  by  M.  Teploflf,  one  of  their  officers. 
I 


Substances. 


Gold  - 
Platinum 
Auriferous  silver 

Copper  - 
Lead 

Cast  iron 

Salt 

Coal 

Naphtha 


1830. 


kil. 
6,260 
1,742 
20,974 

8,860,696 
698,478 

182,721,274 

342,240,893 
7,863,642 
4,253,000 


1831. 


kil. 
6,582 
1,767 
21,563 

3,904,533 
792,935 

180,043,730 

(2) 
282,821,358 
9,774,998 
4,253,000 

12~ 


1832. 


kil. 
6,916 
1,907 
21,454 

3,620,201 
688,351 

162,480,224 

372,776,283 
6,596,034 
4,253,000 


1833. 


kil, 
6,706 
1,919 
20,552 

(3) 

3,387,252 
716,600 

(3) 
159,118,372 

491,862,299 
8,227,528 
4,253,000 


1834. 


kU. 
6,626 
1,695  j 


20,666 

? 
? 


! 


i 


i 


304 


MINES. 


MINES. 


206 


MINES  OF  THE  V08GES  AND  THE  BLACK  FORES?". 

TUese  mountain.  rrLeral  cenUes  ^^^^^^.^^^^^^  ^^  ^^  ^^^^ 
and  copper,  iron  ores,  and  some  mines  of  manganese  ^^^^^^^^^^^     ^iferous  lead  has 

At  the  CroU:.aux^rnines,  department  of  the  Vo3|e^,  a  v^^^^^^^  of  the  greatest  known, 
been  worked,  which  next  to  ^^?  ^^^^^^n  S  and^  mhx^  through  an  extent  of  more 
It  is  several  fathoms  thick,  and  has  been  ^^^f  ^^^^^"^^ich  occurs  some  argentiferous 
than  a  league.     It  is  partly  filled  with  deb"S/mon^w^^^^  ^^  ^.^^^^^  ^^^ 

galena.     It  contains  also  P^^^^P^^/^^f^^f^'e  of  junction  of  the  gneiss,  and  a  por- 
It  runs  from  N.  to  S.  nearly  parallel  ^o  ^he  Ime  oi  ju  ^^^^^^^  .^  ^^^^ 

phyroid  granite,  that  passes  into  s^emte  and  porpnyry  ^^^^^  ^^^^  ^^^^^ 

Ugneiss;  but  it  probably  occurs  also  between  the  t^^^^^^^^  ^^.^  ^^.^  produced,  il 

below  the  level  of  the  adjoining  valley.     1  he  mi^^^^^^  ^^^^  ^^.^^  ^^^^ 

IS  said,  at  the  end  of  the  I6th  century,  26,000/.  per  annum  ,y  ^^  ^^^.^^^ 

ductive  in  the  middle  of  the  last  century,  and  f^rnisbed,  m  noo,  ^,      , 
of  lead,  and  6,000  marcs,  or  3,230  P?«"dsavoirdot  silver  ^  ^^^  ^^^.^ 

The  veins  explored  at  Savnte  ^^^^^f  ^^'^'TeU.^^^^^  from  which  they  are 

direction  is  nearly  perpendicular  to  tha  of  "le  vein  mi     ^^^.^^^     ^^^^^^  ^^^^^^^  ^^^^ 

separated  by  a  barren  mountain  of  sienite.  ,  J  J^^^  ^°  jf^rous.    There  is  found  also  at  a 
of'copper,  cobalt,  and  arsenk  ;  all  more  o^  l^f  ^^^»^^^^^^^^^^  of  antimony.    The 

little  distance  from  Saint  Mary  of  ^^«  ^J»"  ^  a'-i  are  among  the  most  ancient  in 
mines  of  Sai/^eitfarie,  opened  several  centunesa^^^^  the  level  of  the  adjoining 

France ;  and  yet  they  have  been  worked  only  aown  lo 

valleys.  ^        .    ,,«^r,„Jrnn«,nfGiromaffnv,  on  the  southern  verge  of  the 

There  has  been  opened  up  m  the  ^n^  ron«  princSy  argentiferous  ores  of  lead  and 
Vosges,  a  great  number  of  veins  containing  prmc.p^^  porphyries  and  clay-slates  ;  a 
copper.  They  run  nearly  from  N.  t°.^-' ^J^V'^lliferous  district  of  Schemnitz.  The 
system  which  has  some  analogy  "^J^'^.^^^^^'^ZTZ  These  mines  were 

workings  have  been  pushed  so  far  as  f^f  y^^'^^fj^^^and  became  so  once  more  at  the 
in  a  ttourishing  state  in  the  14th  ^^^  16th  ce^^^^^^^^^^  ^^  ^^^^^.^      j^  1743 

beginning  of  the  17th,  when  they  were  ^^f^^^^^J  ^^  ^i^^r  in  the  month. 

thiy  still  produced  100  marcs  funy  02  ^^l;^^]^^'^^^  of  Giromagny,  are  now 

abIntnXbufit^:h%Td\h1t?^r;^^^^^  two  localities  will  be  resumed  ere 

n;-  the  mountains  of  the  Black  Forest,  -P-^^^^^^^^^^^^^^^  ^nd^Taf  H^cl^'/, 

Rhine,  but  composed  of  the  same  ^o/^^'f  P'^j^'^'^'activUy.     These  form  six  distinct 
not  far  from  Freyburg  woi4angs  of  lead  in  great^  a^^  ^^^.^^^^     j^ 

mines,  and  annually  attord  88,000  \\^^^f^l.^^^^^^  are  mines  of  copper,  cobalt, 

Furstenberg  near  I^^o//acA,  particularly  ^t  ^;"*7"^ '^ears  ago,  1,600  marcs,  or  near 
and  silver.     The  mines  of  Wittichen  P^odu<:ed  some  Y^ar^     |^>^  '^^  ^^.^^  ^„d  one  of 

iS^Xof  B^det  aid  in  the  ^^^^^o^o^^^^^^^^  ^^^  ^,^^,^^^,  3,,  ,_  of 

Several  important  iron  mines  are  explored  in  the  Vos  es ,  i  ^^^  ^^^^^ 

FrLarU,  in  ihe  department  of  the  Vosges,  whose  or^s  are  r^^^^^^^^      ^^^^  ^^^  ^^^ 

hematite  which  appear  to  form  J^^^^^^f^f fl: '^st^^^^  greywacke.    The  sub- 

irresular  in  a  district  composed  of  f^en  tone  limestone,  an     gy    i^,      i^,.  There 
terranea A  workings,  opened  on  these  dep«3»tes  have  been  h^^  ^  y^  ^^^^^  ^^  ^ 

has  been  discovered  lately  in  these  mmes,  an  extremely  ricn  .^^^  ^^^  ^^^j^^  . 

At  Rothau,  a  little  to  the  east  of  Framont  thin  vems  of  red  o.^^  ^^  .^^^      ^hese  veins 
sometimes  magnetic,  owing  Probably  to  an  ad  mixture  01  P  ^^^^  ^^^^^^^  ^^^^^  ^^ 

run  through  a  granite,  that  passes  into  sienite.    At  oa 
iron  mines,  analogous  to  those  of  Framont  ^^^^^^  ^^^^^  Moselle,  veins 

In  the  neighborhood  of  Ihann  and  ^f  !.^J!,^^^"^^V,reywacke,  clay-slate,  and  por- 
are  worked  of  an  iron  ore,  that  traverse  formations  0^^  g^^^„^„^ 

phyry.     Lastly,  in  the  north  of  the  V^  f  ^^^^^^f^f;-^^^^ 

several  mines  have  been  opened  on  very  poj^ermi  veu  ^^^^^^      j^ 

bos  ore,  accompanied  with  a  little  <^^l;ri:rre2ced^Ly  vad  ores  of  lead,  the  most 
some  points  of  these  veins,  the  ^^.^'J  «^^^^f  JXed  at  Veite^  ^ndKalzenihal.  These 
abundant  being  the  phosphate,  which  «^J^f  f  ?'^^  j^jlo^  ^hose  geological  position  is  not 
veins  traverse  the  sandstone  of  the  ^os^es  a  formation  who^^^^^^^  ^^^  preceding  at 
alto-ether  well  known,  but  which  contains  »^«"  ,""3"^f.  ^""^'i^.i^atg.  Many  analogies 
Langenthal,  at  the  foot  of  Mount  Tonnerre  -d  -  ,,  palat  na  e. ^  M  ^^.^^^^^ 
seem  to  approximate  to  the  sandstone  of  the  Vos  es  the  sa  ^^  Creutzwald,  and 

rietitiro?^^:-^^^^^^^^^^  °^  ^''^'-'^  ---  ^'^- 

Chapelle. 


At  Cruilnich  and  Tholey,  to  the  north  of  the  Sairebruck,  mines  of  manganese  are 
worked,  famous  for  the  good  quality  of  their  products.  The  deposite  exploited  at  Crutt- 
nich  seems  to  be  enclosed  in  the  sandstone  of  the  Vosges,  and  to  constitute  a  vein  in  it, 
analogous  to  the  iron  veins  mentioned  above. 

There  has  been  recently  opened  a  manganese  mine  at  Lavelline,  near  La  Croix-aux- 
mines,  in  a  district  of  gneiss  with  porphyry. 

In  the  Vosges  and  the  Black  Forest  there  are  several  deposites  of  anthracite  (stone- 
coal),  of  which  two  are  actually  worked,  the  one  at  Zunswir,  near  Oflenbourg,  in  the 
territory  of  Baden,  and  the  other  at  Uvoltz,  near  Cernay,  in  the  department  of  the  Upper 
Rhine.  There  are  also  several  deposites  of  tlie  true  coal  formation  on  the  flanks  of  the 
Vosges. 

MINES   OF   THE   HARTZ. 

The  name  Hartz  is  given  generally  to  the  country  of  forests,  which  extends  a  great 
many  miles  round  the  Brocken,  a  mountain  situated  about  55  miles  W.S.W.  of  Magde- 
bourg,  and  which  rises  above  all  the  mountains  of  North  Germany,  being  at  its  summit 
1226  yards  above  the  level  of  the  sea.  The  Hartz  is  about  43  miles  in  length  from 
S.S.E.  to  N.N.W.,  18  miles  in  breadth,  and  contains  about  450  square  miles  of'surface. 
It  is  generally  hilly,  and  covered  two  thirds  over  with  forests  of  oaks,  beeches,  and  firs! 
This  rugged  and  picturesque  district  corresponds  to  a  portion  of  the  Silva  Hercynia  of 
Tacitus.  As  agriculture  furnishes  few  resources  there,  the  exploration  of  mines  is 
almost  the  only  means  of  subsistence  to  its  inhabitants,  who  amount  to  about  50,000. 
The  principal  cities.  Andreashcrg,  Clausthal,  Zellerfeld,  Mtenau,  Lauienthal,  IVildemann] 
Grundy  and  Goslar,  bear  the  title  of  mine-cities,  and  enjoy  peculiar  privileges  ;  the  people 
deriving  their  subsistence  from  working  in  the  mines  of  lead,  silver,  and  copper,  over 
which  their  houses  are  built. 

The  most  common  rock  in  the  Hartz  is  greywacke.  It  encloses  the  principal  veins, 
and  is  covered  by  a  transition  limestone.  The  granite  of  which  the  Brocken  is  formed 
supports  all  this  system  of  rocks,  forming,  as  it  were,  their  nucleus.  Trap  and  hornstone 
rocks  appear  in  certain  points. 

The  veins  of  lead,  silver,  and  copper,  which  constitute  the  principal  wealth  of  the 
Hartz,  do  not  pervade  its  whole  extent.     They  occur  chiefly  near  the  towns  of  Andreas- 
berg,  Clausthal,  Zellerfeld,  and  Lautenthal ;  are  generally  directed  from  N.W.  to  S.E. 
and  dip  to  the  S.W.,  at  an  angle  of  80'^,  with  the  horizon.  ' 

The  richest  silver  mines  are  those  of  the  environs  of  Andreasberg,  among  which  may 
be  distinguished  the  Samson  and  Newfang  mines,  worked  to  a  depth  of  560  yards.  In 
the  first  of  them  there  is  the  greatest  step  exploitation  to  be  met  with  in  any  mine.  It 
is  composed  of  80  direct  steps,  and  is  more  than  650  yards  long.  These  mines  were 
discovered  in  1520,  and  the  city  was  built  in  1521.  They  produce  argentiferous  galena, 
with  silver  ores  properly  so  called,  such  as  red  silver  ore,  and  ore  of  cobalt. 

The  district  which  yields  most  argentiferous  lead  is  that  of  Clausthal ;  it  comprehends 
a  great  many  mines,  several  of  which  are  worked  to  a  depth  of  550  yards.  Such  of  the 
mines  as  are  at  the  present  day  most  productive,  have  been  explored  since  the  first  years 
of  the  eighteenth  century.  The  two  most  remarkable  ones  are  the  mines  of  Dorothy, 
and  the  mine  of  Caroline,  which  alone  furnish  a  large  proportion  of  the  whole  net  prod- 
uct. The  grant  of  the  Dorothy  mine  extends  over  a  length  of  257  yards,  in  the  direc- 
tion of  the  vein,  and  through  a  breadth  of  nearly  22  yards  perpendicularly  to  that  direc- 
tion. Out  of  these  bounds,  apparently  so  small,  but  which  however  surpass  those  of  the 
greater  part  of  the  concessions  in  the  Hartz,  there  was  extracted  from  1709  to  1807  in- 
clusively, 883,722  marcs  of  silver,  768,845  quintals  of  lead,  and  2,385  quintals  of  copper. 
This  mine  and  that  of  Caroline  have  brought  to  their  shareholders  in  the  same  period 
ol  time,  more  than  1,120,000/.;  and  have  besides  powerfully  contributed  by  loans  with- 
out interest  to  carry  on  the  exploration  of  the  less  productive  mines.  It  was  in  order 
*r  ^-r^u  ^r^  drainage  of  the  mines  of  the  district  of  Clausthal,  and  those  of  the  district 
1^^  adjoining,  that  the  great  gallery  of  efflux  was  excavated. 

Next  to  the  two  districts  of  Clausthal  and  Zellerfeld,  and  Andreasberg,  comes  that  of 
ixoslar,  the  most  important  working  in  which  is  the  copper  mine  of  Rammelsberg,  opened 
since  the  year  968,  on  a  mass  of  copper  pyrites,  disseminated  through  quartz,  and  min- 
gled with  galena  and  blende.  It  is  worked  by  shafts  and  galleries,  with  the  employment 
01  hre  to  break  down  the  ore.  This  mine  produces  annually  from  1,200  to  1,300  metric 
quintals  (about  275,000  libs,  avoird.)  of  copper.  The  galena  extracted  from  it  yields  a 
small  quantity  of  silver,  and  a  very  little  gold.  The  latter  metal  amounts  to  only  the 
nve-millionth  part  of  the  mass  explored  ;  and  yet  means  are  found  to  separate  it  with 
advantage.  The  mine  of  Lauterberg  is  worked  solely  for  the  copper,  and  it  furnishes 
annually  near  66,000  libs,  avoird.  of  that  metal. 

Besides  the  explorations  just  noticed,  there  are  a  great  many  mines  of  iron  in  differ- 
ent parts  of  the  Hartz,  which  give  activity  to  important  forges,  including  21  smelting 


206 


MINES. 


MINES. 


207 


h 


1««     The  principal  o-es  are  sparry  iron,  and  red  and  brown  hematites,  which  occni 

produce  annually  33,000  libs,  avoird.  of  lead.  manganese. 

^  At  the  southern  foot  of  the  Hartz,  at  Ileleld,  ^/'L^^^^^^^^^  Iqq  years.    The 

The  exploration  of  the  Hartz  "^^"^^^"^'^y  ,^,^/T.^h,er^^^^^^^^^  Theirgross 

epoch  of  their  greatest  prosperity  was  the  ^^f^^  °^^^^^^^^^^^  is^heir  principal 

annual  amount  was  in  1808  upward  «[^«.^^..^^J^^^^^^^^  with  36,000  marcs,  or 

product,  of  which  they  ff"^^\^T?fiO%offiavo^d.  of  copper,  and  a  very  great 
^^::^Sr'^e;^^  of  the  S^ming  operations  .  and 

^^^s^?^ris^?rj^^^^f?^f^ 

and  economized  for  floating  down  the  timber  ^"VpTrconstructerremark^  for  their 
view,  dams  or  lakes,  canals,  and  aqueducts,  ^^^^  ^e^  ^^on^^^^^^^^^^^  ^n)und  the  moun- 
good  execution.  The  water-courses  are  [f  ""^«i  "^^^f^erie^  The  open  channels  col- 
fain-sides,  or  throngh  their  interior  as  s^^tejr^^JJ^^^^^^^^^  ^^^^  .^e 

lect  the  rain-waters,  as  well  as  ^^ose  proceeding  from  the^m^^  subten^inean  con- 

springs  and  streamlets,  or  small  "Y^'^^J^J^/^'^Vc^din-  whose  circuits  they  cut  short, 
duits  are  in  general  the  continuation  of  the  precedmw^^^^^^  The  banks  of  some 

These  water-courses  present  ^development  in  whole  otliomiie^  ^^  ^^^^^^^^^^ 

Ih^e  7er.l\Xl'MTo'Lier,  and  37  for  the  extraction  of  ores. 

MINES   OF   THE   EAST   OF    GERMANY. 

parts  of  Saxony,  Bavaria,  Austria,  Moravia  and  Silesia.  ^^^^^ries,  the  richest 

nnlcotalt.  'Thfse  mines,  whose  exploration  ^^^f.^^^  S:d7m^f^^^^^^^^^^^  b'een 

ticularly  those  situated  on  the  'IO^^.^^'-YJ  PliXd  at  Fr^^^^^^^^  at  one  time  consid- 

lon^  celebrated.    The  school  of  mines  ^ff^\'^|^"J^.fJ^'J\he^^st  important  workings, 
ered  as  the  first  in  the  world.    This  '«  a  ^mall  city  near  t^ie  mo  i  i    P  ^^^  _ 

8  leagues  W.S.W.  of  Dresden,   oward  the  ^^^^f^^/-^^^^^^^^  district,  well 

birge^  440  yards  above  the  level  of  the  ^^^^'J^  °,°,  ,Xrth "  woS^^  the  mines,  and 

cleared  of  wood.     These  circumstances  have  modified  the^y^^^^^^^^  ^^.^^ 

render  it  difficult  to  draw  an  exa^t  Pard^^^^  a^l  p  ^Sl  arlT  remarkable  for  the  perfection 

are  their  rivals  in  good  exploration ;  they  are  pecm^^^^ 

with  which  the  engines  are  ^xecued  both  for  drainage  and  exl^^^^  »     ^^^  ^^^ 

by  water  or  horses  ;  for  the  regularity  «{^^\'J«^;^   ^^^  ^^^^Tonn^         belonging 
the  beauty  of  their  walling  masonry.    I"  ^^^^^.P^^y^^^^^^^^       qqq  ^^  jq  noo  men,  who 

.hough  auite  differe^  m    h«  -^f  J-J,\Xet;^     exeeeding  a  few  feet. 
For  a  long  time  back,  those  of  «h?J"V™"^  ™ /^J^,  "^^^  the  increas- 

ii7^e-^h':^iL-=f ?.  HeSj^SS  •  a^  t^  tr^i:5«^e 

^^^::^^^:'^^r:^i^^^^^^^^^^^^  -« of  Besche.- 

gluck  is  also  very  rich.  ,  j  ^^      ^g  formerly  so  flour- 

Among  the  explorations  at  Erzgebrge,theT^e  are  none  Tvhicn^  Freyberg.   In 

iSe\rce°ir^e.rfrc^e«?^^^^ 

"tirtCtL^l<^t  uKscribe  in  detail  the  sUver  mine,  that  occur  Be„ 


Ehren/riedersdorfy  Johanna-Georgenstadt,  jlnnaberg,   OberwieteniheUf  and   Schnetberg. 
Those  of  the  last  three  localities  produce  also  cobalt. 

The  mines  of  Saint-Georges,  near  Schneeberg,  opened  in  the  fifteenth  century  as  iron 
mines,  became  celebrated  some  time  after  as  mines  of  silver.  Toward  the  end  of  the 
fifteenth  century,  a  mass  of  ore  was  found  there  which  afforded  400  quintals  of  silver ;  on 
that  lump,  Duke  Albert  kept  table  at  the  bottom  of  the  mine.  Their  richness  in  silver 
has  diminished  since  then ;  but  they  have  increased  more  in  importance  during  the  last 
two  hundred  years,  as  mines  of  cobalt,  than  they  had  ever  been  as  silver  mines.  Saxony 
is  the  country  where  cobalt  is  mined  and  extracted  in  the  most  extensive  manner.  It 
is  obtained  from  the  same  veins  with  the  silver.  Smalt,  or  cobalt-blue,  is  the  principal 
substance  manufactured  from  it.  The  lead  and  the  copper  are  in  this  country  only  ac- 
cessory products  of  the  silver  mines,  from  which  120,000  lbs.  avoird.  of  the  first  of  these 
metals  are  extracted,  which  are  hardly  sufficient  for  the  metallurgic  operations  ;  and 
from  50,000  to  60,000  lbs.  of  copper.  A  little  bismuth  is  extracted  from  the  mines  of 
Schneeberg  and  Freyberg.  Some  manganese  is  found  in  the  silver  mines  of  the  Erzge- 
birge,  and  particularly  at  Johanna-Georgenstadt. 

The  mines  of  Saxony  produce  a  little  argentiferous  galena,  and  argentiferous  gray 
copper ;  the  minerals  with  a  base  of  native  silver  are  the  principal  ores  ;  they  are  treated 
in  a  great  measure  by  amalgamation.  All  those  of  Freyberg  are  carried  to  the  excel- 
lent smelting-house  of  Halsbriick,  situated  on  the  Malde,  near  that  city.  The  average 
richness  of  the  silver  ores  throughout  Saxony  is  only  from  3  to  4  oz.  per  quintal :  viz., 
nearly  equal  to  that  of  the  ores  of  Mexico,  and  very  superior  to  the  actual  richness  of 
the  ores  of  Potosi.  The  silver  extracted  irom  them  contains  a  little  gold.  The  Saxon 
mines  produce  annually  52,000  marcs  of  silver.  Of  these,  the  district  of  Freybers  alone 
furnishes  46,000 ;  and  among  the  numerous  mines  of  that  district,  that  of  Himmelsfurst 
of  itself  produces  10,000  marcs. 

Silver  mines  exist  also  on  the  southern  declivity  of  the  Erzgebirge,  which  belongs  to 
Bohemia,  at  Joachimsthal  and  Bleystadt,  to  the  northeast  of  Eger.  Argentiferous  gjTlena 
is  chiefly  extracted  from  these.  The  mines  of  Joachimsthal  have  been  explored  to  a 
depth  of  650  yards.  They  were  formerly  very  flourishing ;  but  in  1805  they  were  threat- 
ened with  an  impending  abandonment.  The  ancient  mines  of  Kuttenber?,  situated  in 
the  same  region,  have  been  excavated,  according  to  Agricola,to  upward  of  1,000  yards 
from  the  surface  soil. 

The  southern  slope  of  the  Erzgebirge  possesses  cobalt  mines  like  the  northern  slope; 
but  they  are  of  much  less  importance.  Some  occur,  particularly  in  the  neighborhood 
of  Joachimsthal.  Lastly,  on  the  same  slope,  slightlj^-productive  copper  mines  are  men- 
tioned at  Groslitz,  near  Joachimsthal;  at  Catharineberg,  8  leagues  north  of  Saatz ;  and 
at  Kupferberg,  lying  between  the  two.  At  Groslitz,  the  ore  is  a  cupreous  pyrites,  ac- 
companied by  blende.     The  ores  of  Catharineberg  are  argentiferous. 

Next  to  the  silver  mines,  the  most  important  explorations  of  the  Erzgebirge  are  those 
of  tin.  This  metal  occurs  in  veins,  massive,  and  disseminated  in  masses  of  hyalin  gray 
quartz,  imbedded  in  the  granite ;  it  is  also  found  in  alluvial  sands.  The  most  important  tin 
mine  of  the  Erzgebirge  is  that  of  Altenberg,  in  Saxony,  which  has  been  under  working 
since  the  fifteenth  century.  Some  tin  is  mined  also  near  Gayer,  Ehrenfriedersdorf,  Jo- 
hanna-Georgenstadt, Scheibenberg,  Annaberg,  Seifl'en,  and  Marienberg,  in  Saxony.  At 
Zinnwald  it  is  also  found;  where  the  stanniferous  district  belongs  partly  to  Saxony  and 
partly  to  Bohemia  ;  as  also  important  mines  occur  in  the  latter  territory  at  Schlacken- 
wald  and  Abertham,  and  slightly-productive  ones  at  Flatten  and  Joachimsthal.  In  sev- 
eral of  these  mines,  particularly  at  Altenberg  and  Gayer,  fire  is  employed  for  attacking 
the  ore,  because  it  is  extremely  hard.  In  almost  the  whole  of  them,  chambers  of  too 
grea't  dimensions  have  been  excavated,  whence  have  arisen,  at  diflferent  epochs,  vexa- 
tious sinkings  of  the  ground.  One  of  these  may  still  be  seen  at  Altenberg,  whihh  is  130 
yards  deep,  and  nearly  50  in  breadth.  The  mines  of  Abertham  are  explored  to  a  depth 
of  d50  yards,  and  those  of  Altenberg  to  330.  The  tin  mines  of  the  Erzffebirffe  produce 
annually  484,000  lbs.  avoird.  of  this  metal.  *       s    p      ucc 

The  tin  ores  are  accompanied  by  arsenical  pyrites,  which,  in  the  roastin<'  that  it  un- 
dergoes, produces  a  certain  quantity  of  arsenious  acid. 

The  Erzgebirge  presents  also  a  great  many  iron  mines,  particularly  in  Saxony,  at 
Rodenberg  near  Cradorf,  in  the  county  of  Henneberg,  where  the  workings  penetrate  to 
a  depth  of  220  yards,  and  m  Bohemia,  at  Flatten,  where  may  be  remarked  especially 
the  great  explorations  opened  on  the  vein  of  the  Irrgang. 

There  is  also  in  the  Erzgebirge  a  mine  of  anthracite  (stone  coal)  at  SchcBnfcld,  near 
rrauenstein,  m  Saxony. 

The  ancier^t  rock-formations  which  appear  in  the  remainder  of  Bohemia,  and  in  the 
adjacent  portions  of  Bavaria,  Austria,  Moravia,  and  Silesia,  are  much  less  rich  in  metala 
TM,     P?^^^^^"""^*    ^^  explorations  of  much  importance  exist  there. 
The  Ftchtelgebirge,  a  group  of  mountains  standing  at  the  western  extremity  of  the 


im 


208 


MINES. 


MINES. 


209 


;,    r 


ill  ;i 


1^' 


Erz.'ebirge,  between  Hoff  and  Bayreuth,  contains  some  mines,  among  which  may  be 
notlJed  nrinciDally,  mines  of  magnetic  black  oxide  of  iron.  -or  K-ar  r.r 

ArfentSus  likd  mines  have  been  mentioned  at  Af««,  25  leagnes  W.S.W.  of 
Pr^f e  at  the  N.Etbase  of  the  western  part  of  BomerwaWgeiirge  a  cham  of  mouma  « 
wSepaa'e  Bohemia  from  Bavaria.    There  are  soo»e  also  at  ■P'-^^f^Xm  Mollau 
s  w  nf  Pr;i.ne  at  the  extremity  of  the  mountains  which  separate  Behrun  Jrom  Moiaau. 
lA^lie  latter^  the  arlenS^  is  accompanied  by  blende,  in  wh.ch  the  presence 

'?ealrurhiwn  ^toerved.  Ihese  mines,  and  those  of  Joach^sth^^ 

furnish  annually  at  presen^^^^^^^^^^^^ 

mintTfmeTcuryThe^asferrprt  of  the  Bomerwaldgebirge,  which  separat^^ 

mir/romAustrSand  Moravia,  presents  some  mines  on  >t'?»"'^«'f  .f  P/„4„^,^17J^ 

quantity  of  copper,  and  from  600  to  ™  """^^'q'^'^^/  '  ,„d  ^e  mines  of  arsenical 
^^S^^^^I.Xtf^^^'i^^^ot  chrysoprase  exists  in  the 
mountain  of  Kosennitz. 

MINES  or  THE  CENTRE  OF  FBANCE. 

res'arettrrTetS:  e,"  frhi:i:Vv'er;''?ew'^Lff  ^^^^ 

Tur  towarf  the  eastl™  border  of  the  mass  of  primitive  formations,  m  a  zone  charac- 

'-rvllfeLran'dt-vfaZ^^^^^^^^^^^ 

r^^  ):Lr.ZrS/e,Te"^«eTof 'tt  S  fnd'Vt  A  department  of  the 

Ir  There  exisraV&ilBel  e,  2  lea^^  to  the  south  of  Chessy,  a  deposite  of  copper 
*"  •;  Tb/?w  nf  Chessv  which  was  at  one  time  worked,  but  is  now  standing  st  11. 
pyrites  like  that  of  Ches^y^  Yment  rfSaone  et  Loire,  a  very  abundant  deposite  of  oxide 
^f'  Xa-trj  o^s'e^trapTarenUy  forming  a  mass  in  the  granite,  or  perhaps  above 

"•l.-^Sl  ZnZ  "„rEruS"-ear  Couches,  in  the  same  department,  an  ore  of 

'^^^^::^X:^^^^^.  «  <•«««  vemof  smphure.  of  antimony 

"  There'are  also  in  the  centre  of  France  some  explorations  of  galena,  «»t;"'0»T.  «»d 

TSeT^rrt\XTre'°w^3  "dfr^'ii^iTar^^^^ 

At  presemrresearches  are  making  with  a  view  of  discovering  deposttes  of  such  magnv- 

tude  as  to  pay  the  expense  of  working  it. 


MINES  OF  THE   NORTH 


OF  PORTUGAL  AND  THE  ADJOINING  PARTS  OK  SPAIN. 


Ti,.  r.rthaffinians  anoear  to  have  worked  tin  mines  in  this  part  of  the  peninsula.   It  is 
saS  that  sSrerlySed  in  Portugal  in  the  environs  of  Viscu,  a  province  of  Beix.,  at 


a  place  called  Burraco  dt  Stanno,  Some  veins  of  the  same  metal  were  discovered  in  1787, 
near  Monte-Rey,  in  the  south  of  Gallicia.  They  were  lully  two  yards  thick,  and  were 
incased  in  granite.  This  province  presents  also  deposites  of  anlphuret  of  antimony. 
Some  analogous  ores  are  found  in  Castille  and  Estremadura.  Lead  ores  were  worked  in 
the  last  century  not  far  from  Mogadouro,  on  the  banks  of  the  Sabor,  in  the  province  of 
Tras-Ios-Montes,  and  near  Lon^roiva  on  the  banks  of  the  Rio-Prisco.  Mines  of  plum- 
bago occur  near  Mogadouro.  There  are  also  some  iron  mines  in  the  same  country  near 
Felguiera  and  Torredemnacorvo.  They  supply  the  iron-works  of  Chapa-cunha.  Two 
very  ancient  establishments  of  the  same  kind  exist  in  the  Estremadura  of  Portu«'al; 
the  one  in  the  district  of  Thomar,  and  the  other  in  that  of  Figuiero  dos  Vinhoss :  fhev 
are  supplied  by  mines  of  red  oxide  of  iron,  situated  on  the  frontiers  of  this  province  and 
of  Beira.  One  deposite  of  quicksilver  ore  occurs  at  Couna  in  Portugal.  At  Rio  Tinto 
in  Spain,  on  the  fix)ntiers  of  Portugal,  there  is  a  copper  mine  which  produces  about 
33,000  libs,  avoird.  of  this  metal  per  annum.  The  ore  is  a  copper  pvrites.  The  moun- 
tains  in  the  environs  of  Oporto  present  everywhere  indications  of  the  ores  of  copper  and 
other  metals;  and  it  appears  that  all  this  part  of  the  peninsula  is  in  general  rich  in  me- 
tallic treasures,  but  that  the  want  of  wood  prevents  their  being  mined  to  advanta<'e. 

Besides,  many  of  the  deposites  which  originally  existed  there  must  be  in  a  great  meaa- 
ure  exhausted.     It  was  in  these  countries  chiefly  that  the  gold  and  silver  mines  lay, 
which  the  Carthaginians  and  Romans  worked  with  so  much  advantage,  and  contested 
in  so  keen  a  manner.     Near  Loria  (the  ancient  Numantium),  Azagala,  and   Burgos 
considerable  vestiges  of  the  ancient  workings  may  still  be  seen.  * 

MINES   OF   BRITANNY, 

Britanny  has  hardly  a  better  share  in  mineral  wealth  than  the  countries  we  have  just 
passed  in  review.     There  exist  in  it  at  this  moment  only  two  important  exploitations  • 
which  are,  the  lead  mines  of  Poullaouen  and  Huelgoat,  situated  near  Carhaix.     The  mine 
of  Huelgoat,  celebrated  for  the  plomb-gomme  (hydro-aluminate)  discovered  in  it,  ia 
opened  on  a  vein  of  galena,  which  traverses  transition  rocks.    The  workings  have  sub- 
sisted for  about  three  centuries,  and  have  attained  to  a  depth  of  220  yards.     The  vein  oC 
Poullaouen,  called  the  New  Mine,  was  discovered  in  1741.     It  was  powerful  and  very 
rich  near  the  surface  ;  but  it  became  subdivided  and  impoverished  with  its  depth,  notwith- 
standing which  the  workings  have  been  sunk  to  upward   of  180  yards  below  the  sur- 
face.   In  these  mines  there  are  fine  hydraulic  machines  for  the  drainage  of  the  waters  with 
wheels  from  14  to  15  yards  in  diameter ;  and  water-pressure  machines  have  been  recently 
constructed.    The  mines  employ  more  than  900  workmen,  and  furnish  annually  more  than 
1,200,000  lbs.  avoird.  of  lead,  several  thousand  pounds  of  copper,  and  2,000  marcs,  or 
1,034  lbs.  avoird.  of  silver.     These  are  the  most  important  metallic  mines  of  France. 
Several  veins  of  galena  exist  at  Chaieldudren,  near  Saint-Briex,  but  they  are  not  worked 
at  present.     There  is  also  one  at  Pompean,  near  Rennes,  which  has  been  worked  to  a 
depth  of  140  yards,  but  is  in  like  manner  now  abandoned.     It  affords,  besides  the 
galena,  a  very  large  quantity  of  blende  (sulphuret  of  zinc),  of  which  attempts  are  making 
to  take  advantage.     There  occurs,  also,  a  lead  mine  at  Pierreville,  department  of  the 
Channel,  in  a  formation  connected  with  the  system  of  Britanny.     It  is  opened  on  a  vein 
which  traverses  a  limestone  pretty  analogous  to  that  of  Derbyshire.     The  same  depart- 
naent  presents  a  deposite  of  sulphuret  of  mercury  at  Menildot.     A  few  years  ago,  some 
tin  ore  was  discovered  at  Pyriac,  near  Guerande,  in  the  department  of  the  Loire  Inferi- 
eur,  but  the  researches  since  made  to  find  workable  deposites  have  been  unsuccessful. 
A  mine  of  antimony  was  worked  at  La  Ramee,  department  of  La  Vendee.     Several  of  the 
coal  deposites  lately  mined  in  the  departments  of  La  Sarthe,  La  Mayenne,  and  Mayenne- 
et-Loire,  ought  probably  to  be  legarded  as  more  ancient  than  the  genuine  coal  measure*. 
Table  of  the  production  of  the  French  mines,  during  the  year  1832.* 


Species  of  Mine. 

Number  of 
mines. 

Extent  of 

surface 

conceded. 

Number  of 
workmen. 

Production  is  in 
lOths  of  a  ton. 

Value  of  the 

rough  product 

in  francs. 

Metallic  Subttances. 

Antimony 

Copper 

Iron 

Manganese 

Gold 

Lead  and  silver 

Zinc 

16 

8 

131 

8 

1 
33 

1 

Kilom.  Carres. 

93,8954 

274,18 

1-051,391 

16,54 

0-49 

614,23 

6,80 

130 
258 

8917 
66 

1259 

Melted  antim. 

1-030,98 

Black  copper 

1-376 

Rough  ore 

15-814,690 

6-087 

8-505 

71-232,75 
247.680 
3,630-806,81 ' 
66-849,88 
742-051 

Voun. 


*  lAnnaJts  des  Mines,  torn,  v.,  1834,  p.  67«> 
14 


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MINES. 

MINES  OF  THE   CORRESPONDING    COASTS   OF    GREAT   BRITAIN   AND    IREI»AND. 


MINES. 


211 


The  mines  comprehended  in  this  section  are  situated,  1,  in  Cornwall  and  Devonshire ; 
2  in  the  S.E.  of  Ireland  ;  3,  in  the  island  of  Anglesey  and  the  adjoining  part  of  Wales  ; 
i,  in  Cumberland,  Westmoreland,  and  the  north  of  Lancashire,  and  the  Isle  of  Man  j 
5'  in  the  south  of  Scotland;  6,  in  the  middle  part  of  the  same  country. 

Cornwall  and  Devonshire  present  three  principal  mining  districts ;  viz.,  the  portion 
of  Cornwall  situated  in  the  environs  and  S.W.  of  Truro,  the  environs  of  St.  Austle, 
and  the  environs  of  Tavistock.  ,  j    •  . 

The  first  of  these  districts  is  the  most  important  of  the  three  m  the  number  and  richness 
of  its  mines  of  copper,  tin,  and  lead.    The  ores  of  copper,  which  consist  almost  entirely 
of  copper  pyrites  and  common  sulphuret  of  copper,  constitute  very  regular  veins  running 
nearly  from  east  to  west,  and  incased  most  frequently  in  a  clay-slate  of  a  talcose  or  horn- 
blende nature,  called  fet7/a«,  and  sometimes  in  granite,  which  forms  protuberances  in  the 
middle  of  the  schists.     The  tin  occurs  principally  in  veins,  which,  like  the  preceding, 
traverse  the  killas  and  the  granite.     They  are  also  very  often  directed  nearly  from  east  to 
west,  but  they  have  a  difl'erent  inclination,  or  dip,  from  that  of  the  copper  veins,  which 
cut  them  across  and  interrupt  them,  and  are  consequently  of  more  recent  formation.     The 
tin  ore  forms  also  masses,  which  appear  most  usually  attached  to  the  veins  by  one  ol 
their  points.     Lastly,  it  is  found  in  small  veins  which  traverse  the  granite,  principally 
near  the  points  where  this  rock  touches  the  killas.     Certain  veins  present  the  copper  and 
tin  ores  to£?ether ;  a  mixture  which  occurs  chiefly  near  the  points  of  intersection  of  the 
two  metallic  veins.     Certain  mines  furnish  at  once  both  copper  and  tin ;  but  the  most  part 
produce  in   notable  quantity  onlv  one  of  these  metals.    The  most  important  copper 
mine«»  are  situated  near  Redruth  and  Camborn ;  among  which  may  be  noted  particu- 
larly those    called    Consolidated  Mines,  United  Mines,  Huel-Alfred,  Dolcoath,  Poldice, 
&c      The  principal  tin  mines  are  situated  still  farther  to  the  southwest,  near  Helston, 
Saint-Yues,  &c.    Those  called  Hud  Vor,  Great  Huas,  are  particularly  noticed.     There 
are  several  mines  in  Cornwall  of  which  the  crossing  veins  which  at  once  intersect  and 
throw  out  the  veins  of  copper  and  tin,  contain  argentiferous  galena  and  several  ores  of 
silver.     There  existed  formerly  mines  of  argentiferous  lead  near  Helston  and  Truro. 
There  may  be  now  seen  near  Saint  Michael  an  ore  which,  melted  and  cupelled  on  the 
spot  yields  from  an  ounce  and  a  half  to  two  ounces  of  silver  per  quintal.     Near  Cal- 
stock  a  silver  mine  is  worked,  called  Huel-Saint-Vincent,  which  has  aflorded,  it  is  said, 
in  some  months,  from  900  to  1,000  lbs.  avoird.  of  that  metal.    The  ore,  consisting  of 
hornsilver  and  native  silver,  is  treated  on  the  spot.  «  .     .        ,  -.ir   ,  ry  ■     • 

In  the  environs  of  Saint  Austle,  the  copper  mines  of  East  Crtnnis  and  West  Crtrmts 
deserve  to  be  noticed,  as  well  as  me  lin  mine  of  Polgooth,  opened  on  a  tin  vein ;  and  the 
mine  of  Carclaise,  explored  in  the  open  air  on  a  system  of  small  veins  of  this  metal. 

Near  Tavistock  there  occur  mines  of  copper,  tin,  and  lead.  Among  the  last  may  be 
remarked  particularlv  that  called  Hnel  Betsey,  of  which  the  ores  melted  and  cupelled 
on  the  spot,  afford  an  ounce  and  a  half  of  silver  per  cwt. ;  and  that  of  Beeralston, 
whose  ore  is  sent  to  Bristol  to  be  smelted  there.     It  yields  from  four  to  five  ounces  of 

silver  per  cwt.  •,    ^  o  1      ^.  •     rt  11 

There  are  mines  of  antimony  at  Huel-Boys  in  Devonshire,  and  at  Saltash  m  Cornwall. 
The  tin  and  copper  ores  of  Cornwall  are  accompanied  with  arsenical  pyrites,  which  is 

turned  to  some  account  by  the  fabrication  of  white  arsenic  (arsenious  acid). 

Cornwall   and   Devonshire  produce   annually  about   6,160,000  lbs.  avoird.  of  tin; 

18,700,000  lbs.  avoird.  of  copper;  and  1,760,000  lbs.  avoird.  of  lead.    See  Copper  and 

Tin 

The  tin  is  treated  at  the  mine  localities :  but  the  copper  ores  are  sent  in  their  natural 

state  to  Swansea  in  South  Wales,  to  be  smelted. 

Wood  and  labor  being  very  dear  in  Cornwall  and  Devonshire,  the  mineral  depositea 
of  these  counties  can  not  be  worked  out  so  completely,  nor  can  the  mechanical  prepara- 
tion of  the  ore  be  so  far  pushed,  as  in  several  other  parts  of  the  world.  But  all  the  op- 
erations which  appear  advantageous  are  conducted  in  the  most  judicious,  most  economical, 
and  most  expeditious  manner.  Steam-engines  are  erected  there,  some  of  them  posses- 
sin"  the  power  of  several  hundred  horses.  Many  of  the  mines  are  explored  to  a  depth  of 
upward  of  400  yards ;  and  several  are  celebrated  for  the  boldness  of  their  workings. 
The  one  called  Botallock  Mine,  situated  in  the  parish  of  St.  Just,  near  the  Cornwall 
cape  is  opened  amid  rocks  which  form  the  seacoast,  and  stretches  several  hundred 
yards  under  the  sea,  and  upward  of  200  yards  beneath  its  level.  In  some  points  so 
small  a  thickness  of  rock  has  been  left  to  support  the  weight  of  the  waters,  that  the  roll- 
ing of  pebbles  on  the  bottom  is  distinctly  heard  by  miners  during  a  storm.  The  mine 
of^Huel-werry,  near  Penzance,  was  worked  by  means  of  a  single  shaft  opened  on  the 
toast,  in  a  space  left  dry  by  the  sea  only  for  a  few  hours  at  every  ebb.  A  small  wooden 
tower  was  built  over  the  mouth  of  the  shaft,  which,  being  carefully  calked,  kept  out 


the  waters  of  the  ocean  when  the  tide  rose,  and  served  to  support  the  machines  for  raisin, 
the  ore  and  drainage.     A  vessel  driven  by  a  storm  overturned  it  during  the  ni«'ht  a^ 

put  a  period  to  this  hazardous  mode  ofmining,  which  has  not  been  resumed     °    ' 

The  most  considerable  mines  of  Ireland  are  those  of  Cronebane  and  Tingrony,  and  of 
Ballymartagh,  situated  three  leagues  S.W.  of  Wicklow,  in  the  county  of  thf  s^e  nle. 
Their  object  IS  to  work  the  copper  pyrites,  accompanied  with  some  other  ores  of  copper 
galena,  su  phuret  of  antunony,  as  well  as  pyrites  of  iron,  which  forms  several  flattened 
masses  m  the  clay-slate.  Pretty  extensive  workings  have  been  made  here ;  and  the  ore 
was  transported  in  its  natural  state  to  Swansea.  Veins  or  masses  of  copper  pyrites  and 
galena  are  mined  in  some  other  points  of  the  southeast  of  Ireland,  but  nonVof  them  with 
any  notable  advantage.  The  principal  is  the  lead  mine  situated  in  the  county  of  Tinnerarv 
near  the  village  called  Silver  Mines,  absurdly  enough,  because,  though  s'lVrwrou^^^^^^^ 
for  in  the  lead,  none  was  extracted.  Many  iron  mines  anciently  existed  in  Ireland  bui 
he  destruction  of  the  forests  has  considerably  diminished  their  number  and  aS"^ 
that  only  a  few  remain  m  Kilkenny,  Wicklow,  and  Queen^s  County  »^"viij,  50 

The  isle  of  Anglesey  is  celebrated  for  its  copper  mines,  the  principal  of  which  are 
Mona-mme  and  Parys-mountain.  The  ore  is  a  copper  pyrites,  sometimes  of  considerabk 
volume,  lying  in  masses  m  a  formation  contaming  serpentines  and  different  talcose  rock. 
For  a  long  time  the  workings  were  carried  on  in  the  open  air,  but  the  exterior  exnloral 
Uon  has  been  thereby  compromised.  The  neighboring  coasts  of  Wales  present  some 
inmes  of  the  same  nature  All  the  ores  are  treated  in  a  smelting-house  estaWbh^™^ 
the  isle  of  Anglesey.  The  formation  of  slate-clay  and  greywacke! which  consiitutP^^hA 
greater  part  of  Wales,  and  some  of  the  adjoining  distrfcts'ofEn5and,1ncludetve^^^^^ 
lead  mines,  of  which  we  shall  presently  speak  in  noticing  those  of  far  greater  important 
contained  m  the  more  recent  limestone  formations  of  the  same  regions  ^ 

Pretty  important  mines  of  copper  pyrites  and  red  hematitic  .ron'are  worked  in 
Westmoreland,  and  m  the  neighboring  parts  of  Cumberland  and  LancasMre  The 
copper  ores,  and  a  portion  ot  the  iron  ones,  are  embarked  for  Swansea.  The  rest  of  the 
.T^f^M  ^''^i•^'"'■'*'r  '^'  »n  Wast  furnaces  supplied  with  wood  charcoal  The 
isle  of  Man  aftords  indicaUons  of  lead,  copper,  and  iron,  in  the  mountains  of  Snafle 
which  constitute  Its  centre.  At  Borrowdale  in  Westmoreland,  a  mi^e  Tgi^phUe 
(plumbago)  has  been  worked  for  a  long  period.  It  furnishes  the  black  lead^f  the 
f^rtation'.'"'  ''  '"  ''''''"'''  '"''  '^'  "°^'^-  ^^^  'nineral  occurs  in  mass  In  a  taUsJ 
There  are  famous  lead  mines  in  the  south  of  Scotland,  at  Leadhills  in  Lanarkshir** . 

At'cX  ?n' K  rkc,r  "nff '  ''^  ^^y^^'"^'.-     Some  m'anganese  ha^  i"so  been  found 
At  Cally,  ,n  Kirkcudbrightshire,  a  copper  mine  has  been  lately  discovered  ;  and  a  mine 
of  antimony  has  been  known  for  some  time  at  West  Kirk  in  Dumfriesshire  •  but  neiTher 
has  been  turned  to  good  account.  ""^r^snire ,  oui  neiiner 

In  the  middle  part  of  Scotland,  the  lead  mines  of  Strontian  in  Argyleshire  deserve  to 
be  noticed,  opposite  to  the  northeast  angle  of  the  isle  of  Mull.  They  are  onened  o« 
veins  which  traverse  gneiss.  According  to  Mr.  John  Taylor,  these  mines  and  those  of 
Leadhills  produce  annually  5,610,000  lbs.  avoird.  of  lead. 

wh^.?^?In*''^"r!'j°^^''*"^'^  ^""^'^  ^^"V"  atGrantown  on  the  banks  of  the  Don,  a  river 

b^enUrL'arAtu^r^  '"^'^  ""'  ^'"'""    ^  "''^^  °'  "^^"^  '''''''''  ^^^^ 
A  copper  mine  was  discovered  some  years  back  in  one  of  the  Shetland  isles-  and 
chromate  of  iron  is  now  extensively  worked  there  in  serpentine  and  talc:  ' 

MINES  OF  THE  NORTH  OF  EUROPE. 

These  mines  are  situated  for  the  most  part  in  the  south  of  Norway,  toward  the  middle 
of  Sweden,  and  in  the  south  of  Finland,  a  little  way  from  the  shortlit  iTne  dJaw^from 
the  lake  Onega  to  the  southwest  angle  of  Nor^vay.     A  few  mines  occur  in  thr^nrthp™ 

tZt^n.'lSir  ''''  '"^'^"    ^'^  "^^''^  ''^'^^'^  ^'  thesHe^Si^e:  ZZ":, 

f«Ji'^  TTi°''^"^^****^°T*y  ^'^»*''*  ??  ^^^^'^^  «^t^«  gulf  of  Christiania,  and  on  the  side 
feeing  Jutland,  principally  at  Arendal,  at  Krageroe,  and  the  neighborhood  The  orS 
consist  almost  solely  of  black  oxide  of  iron,  which  forms  beds  or  veins  of  from  4  to  60  fee? 
I '     ''^r'"^  '"^  gneiss,  which  is  accompanied  with  pyroxene  (augite)  epXtes  garne^^^^^ 

co:;ts  anTnaXZ'lv  in?h'"'''  ?  %^r  "-^  ^-^Iting  firgS,  sSedon  t^eT^^^^^^ 
mmln      r  P"^'J"^*»^^y  V^  the  county  of  Laurwig.     Their  annual  product  is  about  16i 

r^of^^LTon':  S i^-efpr^'/"  '''  '--  ^'  -^  -">  ^-  -«>  «^eet  iron,"nal^! 

eP^rlTJ^^'^''^''^  "k^.^^PP^"'  °''°^''  '°"^  °^  ^hi<^h  lie  toward  the  south  and  the 
S.  «nH  L^'"''^'^'  but  the  most  considerable  occur  in  the  north,  at  Quikkne,  zJel 
Selboe,  and  R<Braas,  near  Drontheim.     The  mine  of  Rceraas,  16  miles  from  Drontheim  to 


u 


di2 


MINES. 


MINES. 


219 


t  Hi 


Ihe  S.E.  of  this  city,  is  opened  on  a  very  considerable  mass  of  coppei  pyrites,  and  has 
been  worked  in  the  open  air  since  1664.  It  has  poured  into  the  market  from  hat 
time  till  1791,  77  milUons  of  pounds  avoird.  of  copper.  In  1805,  Us  annual  production 
was  '864,600  Ubs. ;  while  all  the  other  mines  of  Norway  together  do  not  furnish  quite 

one  fourth  of  that  amount.  .  ,^  •..     *  j  r  ^™  i  k 

Norway  comprehends  also  some  celebrated  silver  mines.    They  are  situated  from  15 
to  20  leagues  S.W.  of  Christiania,  in  a  mountainous  country  near  the  city  oi  Kongsberg, 
which  owes  to  them  its  population.     Their  discovery  goes  back  to  the  year  1623,  anU 
their  objects  are  veins  of  carbonate  of  lime,  accompanied  with  asbestos  and  other  sub- 
stances in  which  native  silver  occurs,  usually  in  small  threads  or  networks,  and  some- 
times in  considerable  masses,  along  with  sulphuret  of  silver.     These  veins  are  veir,  nu- 
merous, and  run  through  a  considerable  space,  divided  into  four  districts  (arrondisse- 
ments),  each  of  which  contains  more  than  15  distinct  explorations.     When  a  new  mine  is 
opened   an  excavation  in  the  open  air  is  first  made,  which  embraces  several  veins,  and 
they  then  prosecute  by  subterranean  workings  only  those  that  appear  to  be  of  consequence. 
The  workings  do  not  exceed  1,000  feet  in  depth.     Fire  is  employed  for  a  tacking  the 
ore.     In  1782,  the  formation  of  a  new  gallery  of  efflux  was  commenced,  destined  to  have 
a  length  of  10,000  yards,  and  to  cost  60,000/.     These  mines,  since  their  discovery  Idl 
1792:  have  afforded  a  quantity  of  silver  equivalent  to  four  millions  of  pounds  sterling. 
The  year  1768  was  the  most  productive,  having  yielded  38,000  marcs  of  silver.  At  pres- 
ent  they  give  but  a  very  slender  return;  in  1804  they  were  threatened  with  a  complete 
abandonment.     The  ore  is  treated  by  fusion  ;  the  lead  necessary  for  this  operation  being 
imported  from  England.     There  are,  however,  lead  and  silver  mines  m  the  county  of 
Jarlsbere.  but  they  are  very  slenderly  worked.  ^        .-  -,         wv 

At  Edswald,  50  leagues  N.  of  Christiania,  a  mine  is  w  rked  of  auriferous  pyrites,  with 

a  very  inconsiderable  product.  -nr     r  m.  •  ♦•«..;»    ♦v-- 

Cobalt  mines  may  be  noticed  at  Modum  or  Fossum,  8  leagues  W.  of  Chnstiania ;  they 
are  extensive,  but  of  little  depth.  u- ,»  »,««« 

Lastly,  graphite  is  explored  at  Englidal;  and  chromite  of  iron  deposites  have  been 
noticed  in  some  points  of  Norway.  „i.:«r«v;o«t«  #.f 

The  irons  of  Sweden  enjoy  a  merited  reputation,  and  form  one  of  the  chief  objects  of 
the  commerce  of  that  kingdom.  Few  countries,  indeed,  combine  so  many  valuable  ad- 
vantages for  this  species  of  manufacture.  Inexhaustible  deposites  ol  iron  ore  are  placed 
amid  immense  forests  of  birches  and  resinous  trees,  whose  charcoal  is  probably  the  best 
for  the  reduction  of  iron.  The  diflerent  groups  of  iron  mines  and  forges  form  small 
districts  of  wealth  and  animation  in  the  midst  of  these  desolate  regions. 

The  province  of  Wermeland,  including  the  north  bank  of  the  lake  Wener,  is  one  ot 
the  richest  of  Sweden  in  iron  mines.  The  two  most  important  are  those  of  Nordmarck, 
3  lea^nies  N.  of  Philipstadt,  and  those  of  Persberg,  2|  leagues  E.  from  the  same  city. 
Philipstadt  is  about  50  leagues  W.  J  N.W.  from  Stockholm.  Both  mm es  are  opened 
on  veins  or  beds  of  black  oxide  of  iron  several  yards  thick,  direeted  Irom  N.  to  S.  in  a 
ground  composed  of  hornblende,  talcose,  and  granitic  rocks.  These  masses  are  nearly 
vertical,  and  are  explored  in  the  opea  air  to  a  depth  of  130  yards.  Formerly  this  ex- 
ploitation  was  effected  by  iron  wedges  and  pickaxes ;  but  they  have  been  superseded  by 
gunpowder,  since  1650.  The  province  of  Wermeland,  and  that  of  Dahl  which  adjoins 
it,  forming  the  west  border  of  the  Wener  lake,  contained  in  1767,  48  smelting  cones, 

each  going  from  4  to  5  months  every  year.  _  m  ^     as  -,«  ♦i.^oo  «f 

The  principal  iron  mines  of  Rosslagie  (part  of  the  province  of  Upland)  are  those  of 
Dannemora,  situated  1 1  leagues  from  Upsal.  They  stand  in  the  first  rank  of  those  of 
Sweden,  and  even  of  Europe.  The  masses  worked  upon  are  flattened  and  vertical, 
running  from  N.E.  to  S.W.,  and  are  incased  in  a  ground  formed  of  primitive  rocks, 
among  which  gneiss,  petrosilex  and  granite  are  most  conspicuous.  They  amount  to  three 
in  number,  very  distinct,  and  parallel  to  each  other;  anl  are  explored  through  a  1  jngta 
of  more  than  1,500  yards,  and  to  a  depth  of  above  80,  by  the  employment  of  hre,  and  blast- 
ing with  gunpowder.  The  explorations  are  mere  quarries ;  each  presenting  an  open 
trench  65  yards  wide,  by  a  much  more  considerable  length,  and  an  appalling  depth. 
MagneMc  iron  ore  is  extracted  thence,  which  furnishes  the  best  iron  of  Sweden  and 
Europe  ;  an  iron  admirably  qualified  for  conversion  into  steel.  In  1767,  these  minings 
•upplied  for  a  long  time,  15  smelting  cones  situated  in  Rosslagie,  at  a  distance  ol   10 

^The^sland  of  Utoe,  situated  near  the  coast  of  the  province  of  Upland,  presents  also 
rich  iron  mines.  The  protoxide  of  iron  there  forms  a  thick  bed  m  the  gneiss.  It  is 
worked  in  trenches  far  below  the  level  of  the  sea.  The  ore  can  not  be  smelted  in  the 
island  itself;  but  is  transported  in  great  quantities  to  the  continent.  _     .  .   . 

The  province  of  Smoland  includes  also  very  remarkable  mines.  Near  Jonkoping,  a 
hill  calletl  the  Taberg  occurs,  formed  in  a  great  measure  of  magnetic  black  oxide  ol  Jion, 
contained  in  a  greenstone  reposing  on  gneiss. 


In  several  parts  of  Lapland,  the  protoxide  of  iron  occurs  in  great  beds,  or  immense 
masses.  At  Gellivara,  200  leagues  N.  of  Stockholm,  toward  the  67th  degree  of  lati- 
tute,  it  constitutes  a  considerable  mountain,  into  which  an  exploitation  has  been  opened. 
The  iron  is  despatched  on  small  sledges  drawn  by  reindeer  to  streams  which  fall  into 
the  Lutea ;  and  thence  by  water  carriage  to  the  port  of  Lutea,  where  it  is  embarked 
for  Stockholm. 

There  are  a  great  many  iron  works  in  Dalecarlia,  but  a  portion  of  the  ores  are  got 
from  alluvial  deposites.  Similar  deposites  exist  also  in  the  provinces  of  Wermeland  and 
Smoland. 

The  mines  and  forges  of  Sweden  produce  annually  about  165  millions  of  poundi 
avoird.  (74,000  tons  nearly)  of  cast  iron  or  bar  iron  ;  of  which  two  thirds  are  exported 
chiefly  from  the  harbors  of  Stockholm,  Gottenburg,  Geffle,  and  Norkoping. 

The  copper  mines  of  Sweden  are  scarcely  less  celebrated  than  its  iron  mines.  The 
principal  is  that  of  Fahlun  or  Kopparberg,  situated  in  Dalecarlia,  near  the  town  of 
Fahlun,  40  leagues  N.W.  of  Stockholm.  It  is  excavated  in  an  irregular  and  very 
powerful  mass  of  pyrites,  which  in  a  great  many  points  is  almost  entirely  ferruginous, 
but  in  others,  particularly  near  the  circumference,  it  includes  a  greater  or  less  portion 
of  copper.  This  mass  is  enveloped  in  talcose  or  hornblende  rocks.  More  to  the  west 
there  are  three  other  masses  almost  contiguous  to  each  other,  which  seem  to  bend  in 
an  arc  of  a  circle  around  the  principal  mass.  They  are  explored  as  well  as  the  last. 
This  was  at  first  worked  in  the  open  air ;  but  imprudent  operations  having  caused  the 
walls  to  crumble  and  fall  in,  since  1647  the  excavation  presents  near  the  surface  noth- 
ing but  frightful  precipices.  The  workings  are  now  prosecuted  by  shafts  and  galleries 
into  the  lower  part  of  the  deposite,  and  have  arrived  at  a  depth  of  194  famnars  (nearly 
430  yards).  They  display  excavations  spacious  enough  to  admit  the  employment  of  hor- 
ses, and  the  establishment  of  forges  for  repairing  the  miners'  tools.  It  is  asserted  that 
the  exploration  of  this  mine  goes  back  to  a  period  anterior  to  the  Christian  era.  Du- 
ring its  greatest  prosperity  it  is  said  to  have  produced  1 1  millions  of  pounds  avoird.  of 
copper  per  annum,  or  about  5,000  tons.  It  furnishes  now  about  the  seventh  part  of 
that  quantity ;  yielding  at  the  same  time  about  70,000  lbs.  of  lead,  with  50  marcs  of 
silver,  and  3  or  4  of  gold.  The  ores  smelted  at  Fahlun  produce  from  2  to  2^  of  copper 
per  cent.  But  the  extraction  of  the  metal  is  not  the  sole  process;  the  sulphur  is  also 
procured  ;  and  with  it,  or  the  pyrites  itself,  sulphuric  acid  and  other  chemical  products 
are  made.  Round  Fahlun,  within  the  space  of  a  league,  70  furnaces  or  factories  of 
diflferent  kinds  may  be  seen.  The  black  copper  obtained  at  Fahlun  is  converted  into 
rose  copper,  in  the  refining  hearths  of  the  small  town  of  0/wostad. 

In  the  copper  mine  of  Garpenberg,  situated  18  leagues  from  Fahlun,  there  occur  14 
masses  of  ore  quite  vertical,  and  parallel  to  each  other,  and  to  the  beds  of  mica-slate  or 
talc-slate,  amid  which  they  stand.  This  mine  has  been  worked  for  more  than  six  hun- 
dred years. 

The  mine  of  Nyakopparberg,  in  Nericia,  20  leagues  W.  of  Stockholm,  presents  mas- 
ses of  ores  parallel  to  each  other,  the  form  and  arrangement  of  which  are  very  singu- 
lar.    It  is  worked  by  open  quarrying,  and  with  the  aid  of  fire. 

We  may  notice  also  the  copper  mines  of  Atwidaberg,  in  Ostrogothia,  which  furnish 
annually  the  sixth  part  of  the  whole  copper  of  Sweden. 

There  are  several  other  copper  mines  in  Sweden.  Their  whole  number  is  ten ;  but 
It  was  formerly  more  considerable.  They  yield  at  the  present  day  in  all,  about  2,420,000 
libs,  avoird.  (1000  tons)  of  copper. 

The  number  of  the  silver  mines  of  Sweden  has  in  like  manner  diminished.  In  1767  only 
3  were  reckoned  under  exploration,  viz.,  that  of  HelUf or s,  in  the  province  of  Werme- 
land; that  of  Stgersfors,  in  Nericia;  and  that  of  Sahla  or  Sahlberg,  in  Westmannia. 
aboul  23  leagues  N.W.  of  Stockholm.  The  last  is  the  only  one  of  anv  importance.  It 
is  very  ancient,  and  passes  for  having  been  formerly  very  productive,  though  at  present 
It  yields  only  from  4,000  to  5,000  marcs  of  silver  per  annum.  Lead  very  rich  in  silver  iM 
Its  principal  product.  It  is  explored  to  a  depth  of  more  than  200  yards.  The  sou  JC 
ness  of  the  rock  has  allowed  of  vast  excavations  being  made  in  it,  and  of  even  the  aL 
leries  having  great  dimensions;  so  that  in  the  interior  of  the  workings  there  are  wind- 
ing machines,  and  carriages  drawn  by  horses  for  the  transport  of  the  ores. 
At  Sahlberg,  there  are  deposites  of  sulphuret  of  antimony. 

tor  tlie  last  30  or  40  years  mines  of  cobalt  have  been  opened  in  Sweden,  principally 
at  1  unaberg  and  Los,  near  Nykoping,  and  at  Otward  in  Ostrogothia.  The  first  ai« 
worked  upon  veins  of  little  power,  which  become  thicker  and  thinner  successively; 
Whence  they  have  been  called  head-veins.  It  appears  that  the  products  of  these  mines, 
though  of  good  quality,  are  inconsiderable  in  quantity. 

Lastly  there  is  a  gold  mine  in  Sweden;  it  is  situated  at  Adelfors,  in  the  parish  of 
Alsteda,  and  province  of  Smoland.  It  has  been  under  exploration  since  1737,  on  vein* 
01  auriferous  iron  pyrites,  which  traverse  schistose  rocks;  presenting  but  a  few  inches 


i 


«14 


MINES. 


MINES. 


216 


!    ! 


of  ore.    It  formerly  yielded  from  30  to  40  marcs  of  gold  per  annum,  bnt  for  the  last  few 
years  it  has  furnished  only  from  3  to  4. 

The  mines  and  smelting  works  of  Sweden  gave  annually,  in  1809,  a  gross  product 

worth  1,463,600/.  .  „      .  .  •        v  ♦ 

The  south  of  Finland  and  the  bordering  parts  of  Russia  contain  some  mines,  but 
they  are  far  from  having  any  such  importance  as  those  of  Sweden. 

At  Orijerwy,  near  Helsingfors,  a  mine  of  copper  occurs  whose  gangue  is  carbonate 
of  lime,  employed  as  a  limestone.  ^        «   ,     -r    ,        ,  i  •        i» 

Near  Cerdopol,  a  town  situated  at  the  N.W.  extremity  of  the  Ladoga  lake,  vems  of 
copper  pyrites  were  formerly  mined.  j  •      , 

Under  the  reign  of  Peter  the  Great,  an  auriferous  vein  was  discovered  m  the  granitic 
mountains  which  border  the  eastern  bank  of  the  lake  Ladoga,  near  Olonetz.  It  was 
rich  only  near  the  surface ;  and  its  working  was  soon  abandoned. 

Latterly  an  attempt  has  been  made  to  mine  copper  and  iron  ores  near  Eno,  above 
snd  to  the  N.W.  of  Cerdopol,  but  with  little  success.  .      i  i      oi. 

Some  time  ago  rich  ores  of  iron,  lying  in  veins,  were  worked  near  the  lake  Shuyna, 
N.W.  from  Cerdopol ;  but  this  mine  has  been  also  relinquished. 

On  the  west  bank  of  the  Onega  lake,  there  is  an  iron  work  at  Petrazavodsk,  called 
ft  zavode,  which  is  the  greatest  establishment  of  this  kind  existing  in  the  north  of 

Nothing  is  now  reduced  there  except  bog  iron  ore,  or  swamp  ore  extracted  from  small 

lakes  in  the  neiirhborhood.  ^  „    ,      .  •      ^     j 

The  transition  limestone  which  constitutes  the  body  of  Esthonia  contains  lead  ore  at 
jSrossaar  near  Fellin.  These  ores  were  worked  when  these  provinces  belonged  to  the 
Swedes.     It  was  attempted  in  1806  to  resume  the  exploitation,  but  without  success. 

MINES   OF   THE   ALLEGANY   MOUNTAINS. 

The  chain  of  the  Allegany s,  which  traverses  the  United  States  of  North  America 
from  N.W.  to  S.E.  parallel  to  the  coasts  of  the  Atlantic  ocean,  includes  a  considera- 
ble number  of  deposites  of  iron,  lead,  and  copper  ores  ;  along  with  some  ores  of  silver, 
plumbago,  and  chromite  of  iron.  Attempts  have  been  made  to  mine  a  great  many  of 
these  deposites;  but  most  of  these  have  been  unsuccessful. 

A  bed  of  black  oxide  of  iron  occurs  in  gneiss  near  Franconia  m  New  Hampshire.  It 
has  a  power  of  from  5  to  8  feet;  and  has  been  mined  through  a  length  of  200  feet,  and 
to  a  depth  of  90  feet.  The  same  ore  is  found  in  veins  in  Massachusetts  and  Vermont, 
accompanied  by  copper  and  iron  pyrites.  It  is  met  with  in  immense  quantities  on  the 
western  bank  of  the  lake  Champlain,  forming  beds  of  from  1  to  20  feet  in  thickness, 
almost  without  mixture,  encased  in  granite.  It  is  also  found  in  the  mountains  of  that 
territory.  These  deposites  appear  to  extend  without  interruption  from  Canada  to  the 
neighborhood  of  New  York,  where  an  exploration  on  them  may  be  seen  at  Crown 
Point.  The  ore  there  extracted  is  in  much  esteem.  Several  mines  of  the  same  species 
exist  in  New  Jersey.  The  primitive  mountains  which  rise  in  the  north  of  this  state 
near  the  Delaware,  include  a  bed  almost  vertical  of  black  oxide  of  iron,  which  has  been 
worked  to  100  feet  in  depth.  In  the  county  of  Sussex  the  same  ore  occurs,  accompa- 
nied with  Franklinite.  At  New  Milford,  in  Connecticut,  a  pretty  abundant  mine  of 
gparry  iron  occurs ;  the  only  one  of  the  kind  known  in  the  Alleganys.  The  United 
States  contain  a  great  many'iron  works,  some  of  which  prior  to  the  year  1773,  sent  over 
iron  to  London.     They  are  principally  supplied  from  alluvial  iron  ore. 

The  most  remarkable  lead  mines  of  the  Alleganys  are  those  of  Southampton,  in  Mas- 
Bachusetts,  and  of  Perkiomen  creek,  in  Pennsylvania,  8  leagues  from  Philadelphia.  The 
first  furnishes  a  galena,  slightly  arsentiferous ;  an  ore  accompanied  with  v&rious  min- 
erals, with  base  of  lead,  copper,  and  zinc,  and  with  gangues  (vein-stones)  of  quartz, 
sulphate  of  baryta,  and  fluor  spar.  These  substances  form  a  vein  which  traverses  sev- 
eral primitive  rocks,  and  is  said  to  be  known  over  a  length  of  more  than  6  leagues.  At 
Perkiomen  creek  a  vein  of  galena  is  mined  which  traverses  a  sandstone,  referred  by 
many  geologists  to  the  old  red  sandstone.  Along  with  galena  a  great  variety  of  min- 
erals is  found  with  a  basis  of  lead,  zinc,  copper,  and  iron.  The  mines  of  lead  worked 
in  Virginia,  on  the  banks  of  the  Kanahwa,  deserve  also  to  be  mentioned. 

None  of  the  copper  mines  actually  in  operation  in  the  United  States  seem  to  merit 
particular  attention.  The  mine  of  Schuyler,  in  New  Jersey,  had  excited  high  hopes,  but 
after  the  workings  had  been  pushed  to  a  depth  of  300  feet,  they  have  been  for  some 
years  abandoned.  The  ore,  which  consisted  of  sulphuret  of  copper,  with  oxide  and 
carbonate  of  copper,  occurred  in  a  red  sandstone.  .       ^  . 

In  some  points  of  the  Alleganys,  deposites  have  been  noticed  of  chromite  of  iron  and 

__  V    *4. 

Coal-measures  occur  in  several  points  of  the  United  States,  especially  on  the  N.W. 


slope  of  the  Allegany  mountains.    The  coal  is  mined  successfully  on  the  banks  of  the 
Ohio,  toward  the  upper  part  of  its  course.     See  Anthracite. 

MINES   OF  THE   SOUTH   OF   SPAIN. 

The  mountains  which  separate  Andalusia  from  Estremadura,  Leon  and  La  Mancha, 
and  those  of  the  kingdoms  of  Murcia  and  Grenada,  include  some  celebrated  mines. 

We  shall  mention  first  the  silver  mines  of  Guadalcanal  and  CozaUa,  situated  in  the 
Sierra-Morena,  15  leagues  north  of  Seville.  Among  the  ores,  red  silver  and  argentiferous 
gray  copper  have  been  specified.  Their  product  is  inconsiderable ;  but  this  territory 
presented  formerly  much  more  important  mines  at  Villa-Guttiera,  not  far  from  Seville. 
At  the  beginning  of  the  seventeenth  century  they  are  said  to  have  been  worked  with  such 
activity,  that  they  furnished  daily  170  marcs  of  silver.  More  to  the  east,  there  exists 
in  the  mountains  of  La  Mancha  a  mine  of  antimony,  at  Santa-Crux-de-Mudela.  On 
the  southern  slope  of  the  Sierra-Morena,  very  important  lead  mines  occur,  particularly 
at  Linares,  12  leagues  north  of  Jaen.  The  veins  are  very  rich  near  the  surface,  which 
causes  them  not  to  be  mined  much  in  depth ;  so  that  the  ground  is  riddled,  as  it  were, 
with  shafts.  More  than  5,000  old  and  new  pits  may  be  counted,  the  greater  part  of 
which  is  ascribed  to  the  Moors.  Six  of  these  mines  are  now  explored  on  account  of 
the  crown,  and  they  produce  on  an  annual  average,  according  to  M.  Laborde,  1,320,000 
libs,  avoird.  (about  600  tons)  of  lead,  which  is  too  poor  in  silver  for  this  precious  metal 
to  be  extracted  with  advantage.  Bowles  states  that  there  was  found  at  the  mines  of 
Linares,  a  mass  of  galena,  whose  dimensions  were  from  21  to  24  yards  in  every  direc- 
tion. Abundant  mines  of  zinc  occur  near  Alcaras,  15  leagues  northwest  of  Linares, 
which  supply  materials  to  a  brass  manufactory  established  in  that  town.  There  are  also 
lead  mines  in  the  kingdoms  of  Murcia  and  Grenada.  Very  productive  ores  have  been 
worked  for  some  time  near  Almeira,  a  harbor  situated  some  leagues  to  the  west  of  the 
cape  of  Gates.  The  ore  is  in  part  treated  on  the  spot  with  coal  brought  from  Newcas- 
tle, and  in  part  sent  to  Newcastle  to  be  reduced  there.  The  kingdoms  of  Murcia,  Gre- 
nada, and  Cordova,  include  several  iron  mines.  Near  Cazalla  and  Ronda,  in  the  kingdom 
of  Grenada,  mines  of  plumbago  are  explored. 

On  the  northern  flank  of  the  Sierra-Morena,  lie  the  famous  quicksilver  mines  of 
Almaden,  situated  near  the  town  of  the  same  name  in  La  Mancha.  They  consist  of 
very  powerful  veins  of  sulphuret  of  mercury,  which  traverse  a  sandstone,  evidently  of  a 
geological  age  as  old  at  least  as  the  coal  formation.    Hard  by,  beds  of  coal  are  mined. 

MINES   OF   THE    PYRENEES. 

The  Pyrenees,  and  the  mountains  of  Biscay,  of  the  Asturias,  and  the  north  of  Galicia, 
which  are  their  prolongation,  are  not  very  rich  in  deposites  of  ores  :  the  only  important 
mines  that  occur  there,  are  of  iron  ;  which  are  widely  spread  throughout  the  whole 
chain,  except  in  its  western  extremity.  We  may  mention  particularly  in  Biscay,  the 
mine  of  Sommorosiro,  opened  on  a  bed  of  red  oxide  of  iron ;  and  in  the  province  of 
Guipuscoa,  the  mines  of  Mundragon,  Oyarzun,  and  Berha,  situated  on  deposites  of  sparry 
iron.  There  are  several  analogous  mines  in  Aragon  and  Catalonia.  In  the  French 
part  of  the  Pyrenees,  veins  of  sparry  iron  are  worked  which  traverse  the  red  sandstone 
of  the  mountain  Ustelleguy,  near  Baygorry,  department  of  the  Basses-Pyrenees.  The 
same  department  aflbrds  in  the  valley  of  Asson  the  mine  of  Haugaron,  which  consists  of 
a  bed  of  hydrate  of  iron,  subordinate  to  transition  limestone.  The  deposite  of  hydrate 
of  iron,  worked  for  ar  immemorial  time  at  Rancie,  in  the  valley  of  Viedessos,  depart- 
ment of  the  Arriege,  occurs  in  a  similar  position.  The  ancient  workings  have  been 
very  irregular  and  very  extensive ;  but  the  deposite  is  still  far  from  being  exhausted. 
There  are  also  considerable  mines  of  sparry  iron  at  Lapinouse,  at  the  tower  of  Batera, 
at  Escaron,  and  at  Fillols,  at  the  foot  of  the  CanigoUy  in  the  department  of  the  Oriental 
Pyrenees.  The  iron  mines  of  the  Pyrenees  keep  in  activity  200  Catalanian  forges. 
Although  there  exists  in  these  mountains,  especially  in  the  part  formed  of  transition 
rocks,  a  very  great  number  of  veins  of  lead,  copper,  cobalt,  antimony,  &c.,  one  can 
hardly  mention  any  workings  of  these  metals ;  and  among  the  abandoned  mines,  the 
only  ones  which  merit  notice  are — the  mine  of  argentiferous  copper  of  Baygorry,  in  the 
department  of  the  Low  Pyrenees,  the  lead  and  copper  mine  of  Aulus,  in  the  valley  of 
the  Erce,  department  of  the  Arriege,  and  the  mine  of  cobalt,  of  the  valley  of  Gistain, 
situated  in  Aragon,  on  the  south'^rn  slope  of  the  Pyrenees.  It  is  asserted,  however, 
that  a  lead  mine  is  in  actual  operation  near  Bilboa,  in  Biscay.  The  mines  of  plumbago 
opened  at  Sahun,  in  Aragon,  should  not  be  forgotten.  Analogous  deposites  are  known 
to  exist  in  the  department  of  the  Arriege,  but  they  are  not  mined. 

MIVES   OF  THE   ALPS. 

The  mines  of  the  Alps  by  no  means  correspond  in  number  and  richness  with  the 
extent  and  mass  of  these  mountains.     On  their  eastern  slope,  in  the  department  of  the 


216 


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MINES. 


217 


J 

1    '■; 

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1 

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high  and  tJie  low  Alps,  several  lead  and  copper  mines  are  mentioned,  all  inconsiderable 
and  abandoned  at  the  present  time,  with  the  exception  of  some  workings  of  galena, 
which  furnish  also  a  little  graphite.  i    ^     j  « 

During  some  of  the  last  years  of  the  eighteenth  century,  there  was  mined  at  la  Gardette 
in  the  Oisans,  department  of  the  Isere,  a  vein  of  quartz  which  contained  native  gold 
and  auriferous  pyrites ;  but  the  product  has  never  paid  the  expenses,  and  the  mine  has 
been  abandoned.  The  Oisans  presented  a  more  important  mine,  but  it  also  has  been 
given  up ;  it  was  the  silver  mine  of  Mlemant  or  Chalanches  The  ore  consisted  of 
difl'erent  mineral  species  more  or  less  rich  in  silver,  disseminated  in  a  clay  which  filled 
the  clefts  and  irregular  cavities  in  the  middle  of  talcose  and  hornblende  rocks.  This 
mine  yielded  annually  toward  the  conclusion  of  the  eighteenth  century-,  so  much  as  2,000 
marcs  of  silver,  along  with  some  cobalt  oie.  Among  the  great  number  of  mineral  spe- 
cies, which  occurred  in  too  small  quantities  to  be  worked  to  advantage,  there  was  native 
antimony,  sulphuret  of  mercury,  &c.  The  Oisans  present,  moreover,  some  rather  un- 
productive mines  of  anthracite.  Mines  of  an  analogous  nature,  but  more  valuable,  are 
in  activity  at  the  western  foot  of  the  Alps,  at  la  MothCy  Notre-des-Vaux  d  Putteville,  a 
few  leagues  southeast  of  Grenoble. 

From  the  entrance  of  the  valley  of  the  Oisans  to  the  valley  of  the  ^rc  in  Savoy,  there 
occur  on  the  N.W.  slope  of  the  Alps,  a  great  many  mines  of  sparry  iron.  The  locality 
of  this  ore  is  here  very  difficult  to  define.  It  appears  to  form  sometimes  beds  or  masses, 
and  sometimes  veins  amid  the  talcose  rocks.  Some  is  also  found  in  small  veins  in  the 
first  course  of  the  calcareous  formation  which  covers  these  locks.  These  mines  are  verj 
numerous  ;  the  most  productive  occur  united  in  the  neighborhood  of  Mlevardy  depart- 
ment of  the  Isere,  and  of  Saint  Georges  d'Huretieres  in  Savoy.  Those  of  Forneaux  and 
Laprat,  in  the  latter  country,  are  also  mentioned.  The  irregularity  of  the  mining  op- 
erations surpasses  that  of  the  deposites ;  the  mines  have  been  from  time  immemorial  in 
the  hands  of  the  inhabitants  of  the  adjoining  villages,  who  work  in  them,  each  on  his 
own  account,  without  any  prearrangement,  or  other  rule  than  following  tlie  masses  of 
ore  which  excite  hopes  of  the  most  considerable  profit  in  a  short  space  of  time.  What 
occurs  in  almost  every  mine  of  sparry  iron,  is  also  to  be  seen  here — most  imprudent 
workings.  The  mine  called  the  Grand  Fosse^  at  Saint  Georges  d'Hurctieres,  is  prolonged 
without  pillars  or  props,  through  a  height  of  130  yards,  a  length  of  220  yards,  and  a 
breadth  equal  to  that  of  the  deposite,  which  amounts  in  this  place  to  from  8  to  13  yards  ; 
thus  a  void  space  is  exhibited  of  nearly  300,000  square  yards.  The  sparry  iron  extracted 
from  these  different  mines  supplies  materials  to  10  or  12  smelting-furnaces,  the  cast-iron 
of  which,  chiefly  adapted  for  conversion  into  steel,  is  manufactured  in  part  in  the  cele- 
brated steel  works  of  Rivesy  department  of  the  Isere.  There  occurs  in  some  parts  of  the 
aiines  of  Saint  Georges  d'HujcHeres  copper  pyrites,  which  is  smelted  at  Jis,uebelle. 

Savoy  presents  celebrated  lead  mines  at  Pescy  and  at  Macot,  7  leagues  to  the  east  of 
Moutiers.  Galena,  accompanied  with  quartz,  sulphate  of  baryta,  and  ferriferous  car- 
bonate of  lime,  occurs  in  mass  in  talcose  rocks.  The  mine  of  Pescy  had  been  restored 
to  activity  by  the  French  government,  which  established  there  a  practical  school  of  mines ; 
and  in  its  hands  the  mine  produced  annually  as  much  as  440,000  libs,  avoird.  of  lead, 
and  2,500  marcs  of  silver.  It  is  now  explored  on  account  of  the  king  of  Sardinia  ;  but 
it  begins  to  be  exhausted,  and  yields  less  products.  That  of  Macot^  opened  a  few  years 
ago,  begins  to  give  considerable  returns.  The  mine  of  copper  pyrites  of  Servoz,  in  the 
valley  of  the  Arve,  may  also  be  mentioned.  The  ore  occurs  both  in  small  veins,  and 
disseminated  in  a  clay  slate ;  but  the  exploration  is  now  suspended.  Lastly,  slightly- 
productive  workings  of  anthracite  are  mentioned  in  several  points  of  these  mountains, 
and  in  the  conterminous  portions  of  the  Alps. 

There  exist  in  Piedmont  some  small  mines  of  argentiferous  lead.  The  copper  mines 
ofMlagne.  and  those  of  OUomont,  formerly  yielded  considerable  quantities  of  this  metal. 
Their  exploration  is  now  on  the  deeline.  The  manganese  mines  of  Saint-Marcel  have 
few  outlets ;  whence  they  have  been  feebly  developed.  Mines  of  plumbago,  little 
worked,  occur  in  the  neisrhborhood  of  Vinay,  and  in  the  valley  of  Pellis,  not  far  from 
PigneroL  Some  mines  of  auriferous  pyrites  have  also  been  worked  in  this  district  of 
country ;  among  others,  those  o{  Macugnaga^  at  the  eastern  foot  of  Monte-Rosa.  The 
pyrites  of  this  mine  aflbrded  by  amalgamation  only  11  grains  of  gold  per  quintal;  and 
this  gold,  far  from  being  fine,  contained  one  fourth  of  its  weight  of  silver;  they  became 
less  rich  in  proportion  as  they  receded  from  the  surface.  The  explorations  of  auriferous 
pyrites  in  Piedmont  are  now  abandoned,  or  nearly  so.  The  only  important  mines  in 
this  country  are  those  of  iron.  These  generally  consist  of  masses  of  black  oxide  of 
iron,  of  a  nature  analogous  to  those  of  Sweden ;  the  principal  ones  being  those  of 
Cogne  and  Traverselle,  which  are  worked  in  open  quarries.  Some  others,  less  consid- 
erable, are  explored  by  shafts  and  galleries.  These  ores  are  reduced  in  33  smelting- 
cupolas,  55  Catalan  forges,  and  105  refinery-hearths.  The  whole  produce  about  10,000 
tons  of  bar -iron. 


There  i**  a  mine  of  black  oxide  of  iron,  at  present  abandoned,  at  Bwemier,  near  Mar- 
lignyj  in  i''^  Valais.  There  is  also  another  iron  mine  at  Chamoissons,  in  a  lolly  calca- 
reous' mountain  on  the  right  bank  of  the  Rhone.  The  ore  presents  a  mixture  of  oxide 
of  iron  and  some  other  substances,  of  which  it  has  been  proposed  to  make  a  new  mineral 
species,  under  the  name  of  Chamoissite. 

The  district  of  the  Grisons  possesses  iron  mines  with  very  irregultu"  workings,  situated 
a  few  leagues  from  Coire. 

The  mountain  of  Falkenstein,  in  the  Tyrol,  formed  of  limestone  and  clay-slate,  not  far 
from  Schwatz,  a  little  below  Inspruck,  in  the  valley  of  the  Inn,  contains  mines  of  argen- 
tiferous copper.  At  one  of  them,  that  of  Kiitz-Piihl,  the  workings  reached,  in  1759, 
according  lo  the  report  of  MM.  Jars  and  Duhamel,  nearly  1,100  yards  in  depth ;  and 
were  reckoned  the  deepest  in  Europe.  But  it  was  intended  to  abandon  them.  Analo- 
gous ores  are  explored  in  several  other  points  of  the  same  country.  The  most  part  of 
the  products  of  these  mines  are  carried  to  the  foundry  of  Brixlegg,  4  leagues  from 
Schwatz.  The  mines  of  the  Tyrol  furnished,  on  an  average  of  years,  toward  1759, 
10  000  marcs  of  silver ;  at  anterior  periods,  their  products  had  been  double ;  but  now  it 
is  a  little  less.  This  region  contains  also  cold  mines  whose  exploration  goes  back  a 
century  and  a  half.  They  occur  near  the  village  of  Zell,  8  leagues  from  Schwatz ;  the 
auriferous  veins  traverse  clay-slates  and  quartz  rocks.  Lastly,  a  deposite  of  oxide  of 
chrome  similar  to  that  of  the  Ecouchets  (Saone  and  Loire)  has  been  discovered  in  the 
Tyrol.    An  unimportant  mine  of  mercury  has  also  been  mentioned  in  that  country,  near 

Brenner. 

In  the  territory  of  Saltzburg  there  are  some  copper  mines.  In  the  environs  of  Muer- 
winkel  and  of  Gastein  some  veins  are  worked  for  the  gold  they  contain ;  of  which  the 
annual  return  is  valued  at  118  marcs  of  this  metal.  There  is  an  inconsiderable  mine 
of  quicksilver  at  Leogang. 

In  the  Tyrol  and  in  Saltzburg  there  are  iron  mines  in  a  very  active  state,  principally 
those  of  Kleinboden,  near  Schwatz.  But  the  portion  of  the  Alps  most  abundant  in 
mines  of  this  metal,  is  the  branch  stretching  toward  Lower  Austria.  We  find  here,  both 
in  Styria  and  in  Austria,  a  very  great  number  of  explorations  of  sparry  iron.  The  de- 
posites of  the  ores  of  sparry  iron  of  Eisenerz,  Erzberg,  Admont,  and  Vordenberg,  deserve 
notice.     The  latter  are  situated  about  25  leagues  southwest  of  Vienna. 

The  southern  flank  of  the  Alps  contains  also  a  great  many  mines  of  the  same  kind, 
from  the  Lago  Maggiore  to  Carinthia.  Those  situated  near  Bergamo,  and  those  of 
Huttenbcrg  and  Waidenstein,  in  Carinthia,  are  especially  mentioned. 

All  these  mines  of  sparry  iron  are  opened  in  the  midst  of  rocks  of  different  natures, 
which  belong  to  the  old  transition  district  of  the  Alps.  They  seem  to  have  close  geo- 
logical relations  with  those  of  Allevard. 

The  branch  of  the  Alps  which  extends  toward  Croatia,  presents  important  iron  mines, 
in  the  mountains  of  Adelsberg,  10  leagues  southwest  from  Laybach,  in  Carniola. 

The  iron  mines  just  now  indicated  in  the  part  of  the  Alps  that  forms  a  portion 
of  the  Austrian  states,  supply  materials  to  a  creat  many  smelting-works.  In  Styria 
and  in  Carinthia,  more  than  400  furnaces  or  foft^es  may  be  enumerated,  whose  annual 
product  is  nearly  25,000  tons  of  iron.  These  two  provinces  are  famous  for  the  steel 
which  they  produce,  and  for  the  steel  tools  which  they  fabricate,  such  as  sythes.  Sec. 
Carniola  contains  also  a  great  many  forges,  and  affords  annually  about  5,000  tons  of 
iron. 

There  are  mines  of  argentiferous  copper,  analogous  to  those  of  the  Tyrol,  at  Schlad- 
min?  in  Styria,  at  Kirchdorf  in  Carinthia,  at  Agordo  in  the  territory  of  Venice,  and  at 
Zamabor  in  Croatia.  The  latter  are  remarkable  for  the  great  irregularity  of  the  de- 
posites, and  for  the  richness  of  the  copper  pyrites  that  is  mined  ;  which  produces  12  and 
sometimes  27  per  cent,  of  copper.  There  are  some  deposites  of  antimony,  mined  to  a 
triflin?  extent  in  Carinthia ;  and  there  are  a  few  cobalt  mines  in  Styria,  not  more  actively 
worked.  In  the  environs  of  Raibely  in  Carinthia,  mines  of  calamine  exist,  yielding  an- 
nually about  200  tons  of  this  substance.  Of  late,  some  of  it  has  also  been  explored  in 
Styria. 

The  limestones  that  cover  the  northern  slopes  of  the  Alps,  present,  like  those  of  the 
departments  of  the  lower  and  upper  Alps,  several  lead  mines  of  little  consequence;  they 
also  include  several  celebrated  mines  of  rock  salt. 

The  analogous  limestones  which  repose  on  the  slopes  of  the  Alps  in  Carinthia,  and 
in  the  neighboring  provinces,  afford  likewise  lead  mines,  especially  near  Willach  and 
Bleyberg.  These  mines  are  very  numerous,  forming  more  than  500  arrondisscments  of 
concessions.  They  furnish  annually  about  1,800  tons  of  a  lead  too  poor  in  silver  to  pay 
the  expense  of  extracting  that  precious  metal.  At  the  mines  of  Bleyberg,  the  galena 
forms  14  beds  or  strata^  inclined  at  an  an?le  of  from  40  to  50  degrees  from  the  horizon, 
and  alternating  with  a  like  number  of  calcareous  strata.  The  latter  are  extremely  full 
of  shells.    They  of  course  belong  to  secondary  limestone. 


218 


MINES. 


MINES. 


219 


I 


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I 


The  limestones  surmounting  the  southern  slope  of  the  Alps,  contain  also  some  lead 
mines ;  but  the  quicksilver  mines  of  Idria,  situated  at  the  foot  of  the  Alps,  10  leagues 
N.W.  of  Trieste,  is  worthy  of  particular  notice  ;  it  lies  in  a  limestone  which  everything 
leads  us  to  refer  to  the  zechstein,  the  most  ancient  of  the  secondary  limestones. 

The  Apennines,  which  may  be  considered  as  a  dependance  of  the  Alps,  present  a 
small  number  of  mines.  At  Chiavary  and  Pignone,  manganese  is  mined ;  and  at  the  be- 
ginning of  the  eighteenth  century  a  vein  of  mercury  was  worked  at  Levigliani  in  Tus- 
cany.   An  antimonial  mine  is  mentioned  at  Pereta  in  the  marshes  of  Sienna. 

Before  quitting  these  regions,  we  ought  to  notice  the  iron  mines  of  the  isle  of  Elba 
They  have  been  famous  for  18  centuries ;  Virgil  denotes  them  as  inexhaustible,  and 
supposes  them  to  have  been  open  at  the  arrival  of  ^neas  in  Italy.  They  are  explored 
by  open  quarries,  working  on  an  enormous  mass  of  specular  iron  ore,  perforated  with 
cavities  bespangled  with  quartz  crystals.  The  island  possesses  two  explorations,  called 
Rio  and  Terra-Nuova;  the  last  having  been  brought  into  play  at  a  recent  period.  The 
average  amount  extracted  per  annum  is  15,000  tons  of  ore,  which  are  smelted  in  the 
foundries  of  Tuscany,  Liguria,the  Roman  slates,  the  kingdom  of  Naples,  and  the  island 

of  Corsica.  /••  /-i       j 

There  has  been  worked  for  a  few  years  a  mine  of  chromite  of  iron,  at  Carrada,  near 

Gassino,  department  of  the  Var. 

MINES   SITUATED    IN   THE   SCHISTOSE    FORMATIONS   OF   THE  BANKS    OF  THE   RHINE,  AND 

IN   THE   ARDENNES. 

The  transition  lands,  which  form,  in  the  northwest  of  Germany  and  in  Flanders,  a 
pretty  extensive  range  of  hills,  include  several  famous  mines  of  iron,  zinc,  lead,  and 
copper.  The  latter  lie  on  the  right  bank  of  the  Rhine,  in  the  territories  of  Nassau 
and  Berg,  at  Baden,  Augslbach,  Rheinbreitenbach,  and  near  Dillenburg.  That  of 
Rheinbreitenbach  yielded  formerly  110,000  libs,  avoirdupois  of  copper  per  annum,  and 
those  of  the  environs  of  Dillenburg  now  furnish  annually  176,000  libs.  There  are  also 
some  mines  of  argentiferous  lead^  in  the  same  regions.  The  most  remarkable  are  in 
the  territory  of  Nassau,  such  as  those  of  Holzapfel,  Pfingstiviese,  Loewenburg,  and 
Augstbach  on  the  Wiede,  and  Ehrenthal  on  the  banks  of  the  Rhine,  which  all  together 
produce  600  tons  of  lead,  and  3,500  marcs  of  silver.  To  the  above,  we  must  add  those 
of  the  environs  of  Siegen  and  Dillenburg,  in  the  territories  of  Berg.  A  little  cobalt 
is  explored  in  the  neighborhood  of  Siegen,  and  some  mines  of  the  same  nature  are 
mentioned  in  the  grand  dutchy  of  Hesse-Darmstadt,  and  in  the  dutchy  of  Nassau 

Usingen. 

But  iron  is  the  most  important  product  of  the  mines  on  the  right  bank  of  the  Rhine. 
Veins  of  hydrate  of  iron,  or  brown  hematite,  are  explored  in  a  great  many  points  of 
Hessia,  and  the  territory  of  Nassau,  Berg,  Marck,  Tecklenbourg,  and  Siegen,  along 
with  veins  or  masses  of  sparry  iron,  and  beds  of  red  oxide  of  iron.  We  may  note  par- 
ticularly— 1.  The  enormous  mass  of  sparry  iron,  known  under  the  name  of  Slahlberg, 
mined  since  the  beginning  of  the  fourteenth  century  in  the  mountain  of  Martinshardt, 
near  Miissen,  where  improvident  excavations  have  occasioned,  at  several  times,  consid- 
erable downfallings  of  rubbish  ;  2.  The  abundant  and  beautiful  mines  of  hydrate  of  iron 
and  sparry  iron  on  the  banks  of  the  Lahn  and  the  Sayn,  and  among  those  of  the  mine 
of  Bendorf ;  3.  The  mine  of  Hohenkirchen  in  Hessia,  where  a  powerful  bank  of  manga- 
niferous  ore  is  worked,  and  where  the  mines  are  kept  dry  by  a  gallery  more  than  1,000 
yards  lonsr,  walled  over  its  whole  extent.  These  several  mines  supply  a  great  many 
iron  works,  celebrated  for  their  steel,  and  for  the  objects  of  hardware,  sythes,  &c.,  fab- 
ricated there.  ^  ,      ,       «  »  . 

The  Prussian  provinces  of  the  left  bank  of  the  Rhine,  the  dutchy  of  Luxembourg, 
and  the  Low  Countries,  include  also  many  iron  furnaces,  of  which  a  great  number  are 
supplied,  in  whole  or  in  part,  by  ores  of  hydrate  of  iron,  occasionally  zinciferous,  ex- 
tracted from  the  transition  rocks,  where  they  form  sometimes  veins,  and  sometimes  also 
very  irregular  deposites.  A  portion  is  explored  by  open  quarryinsr,  and  a  portion  by 
underground  workings.  Some  of  these  mines  penetrate  to  a  depth  of  87  yards,  and  galle- 
ries maybe  observed  in  them  cut  in  the  form  of  vaults,  and  timbered  with  hooped  stays. 
The  Hundsriick,  the  Eiffel,  and  the  territory  of  Luxembourg,  present  a  great  many  of 

them. 

The  Eiffel  formerly  possessed  important  lead  mines.  Some  still  exist,  which  are  feebly 
worked  at  Berncastle,  8  leagues  below  Treves,  on  the  banks  of  the  Moselle.  Those 
of  Trarbach,  situated  2  leagues  lower,  are  now  completely  abandoned  ;  the  same  holds 
with  those  of  Bleyalf,  which  were  opened  on  veins  incased  in  the  greywacke-slate,  3 
leagues  W.N.W.  of  Priim,  not  far  from  the  line  of  separation  of  the  waters  of  the  Mo- 
selle and  the  Meuse,  in  a  district  from  which  manufactures  and  comfort  have  disap- 
peared since  the  mines  were  given  up  which  sustained  them. 

More  to  the  north  a  great  many  deposites  of  calamine  occur.    The  most  considerabk», 


Rnd  the  one  explored  with  most  activity,  is  situated  in  the  territory  of  Limbui^ 
(kingdom  of  the  Netherlands),  and  known  under  the  name  of  the  Great  mountain. 
it  presents  a  mass  about  45  yards  wide,  from  400  to  550  long,  and  of  an  unknown 
depth.  The  first  labors,  undertaken  several  centuries  age  by  the  Spaniards,  were  exe- 
cuted by  open  quarrying,  and  pushed  down  32  yards  from  the  surface.  The  miners  were 
obliged  to  renounce  this  mode  of  operation,  and  have  since  penetrated  to  the  depth  of 
88  yards  by  means  of  subterranean  workings.  From  50  to  60  men  work  in  this  exca- 
vation, and  exact  annually  from  700  to  800  tons  of  calamine,  worth  from  2,400/. 
to  2,700/.  In  the  adjacent  parts  of  the  Prussian  territory,  not  far  from  Aix-la-Chapelie, 
calamine  is  also  mined,  with  ores  of  lead  and  iron,  with  which  it  is  associated,  in 
deposites  regarded  by  M.  Bouesnel,  as  analogous  to  the  vein  of  Vedrin,  to  be  noticed 
presently.  The  exploration  is  effected  by  means  of  small  round  shafts,  from  34  to  44 
yards  deep,  which  are  often  wooded  only  with  flexible  branches  of  trees,  or  a  kind  of 
barrel-hoops.  These  workings  may  furnish  annually  from  1,500  to  2,000  tons  of  cala- 
mine, to  the  brass  factories  of  Stollberg.  On  the  right  bank  of  the  Rhine,  in  the  country 
of  la  Marck,  several  small  zinc  mines  furnish  annually  about  130  tons  of  calamine  to 
the  brass  manufactures  of  Iserlohn. 

The  lead  mine  of  Fedrin,  alluded  to  above,  lies  at  some  distance  N.  of  Namur.  It  is 
opened  on  a  vein  of  galena  nearly  vertical,  which  crosses  from  N.  to  S.  a  limestone  in 
nearly  vertical  strata,  probably  analogous  into  the  limestone  of  Derbyshire.  The  vein 
is  from  4  to  15  feet  thick,  and  is  recognised  through  a  length  of  half  a  league.  The  mine, 
worked  for  two  centuries,  presents  very  extensive  excavations ;  particularly  a  fine 
gallery  of  efilux.  It  has  produced  annually  900  tons  of  lead.  At  the  present  day  the  mine 
of  Vedrin,  and  some  adjoining  exploitations,  afford  per  annum  only  about  200  tons  of 
lead,  and  700  marcs  of  silver. 

MINES  OF  THE  CALCAREOUS  MOUNTAINS  OF  ENGLAND. 

The  limestone  formation  immediately  subjacent  to  the  coal  measures,  or  the  mountain 
limestone,  constitutes  almost  alone  several  mountainous  regions  of  England  and  WeJes ; 
in  which  three  districts  very  rich  in  lead  mines  deserve  to  be  noted. 

The  first  of  these  districts  comprehends  the  superior  parts  of  the  valleys  of  the  Tyne, 
the  Wear,  and  the  Tees,  in  the  counties  of  Cumberland,  Durham,  and  York.  Its 
principal  mines  are  situated  near  the  small  town  of  Alston-Moor,  in  Cumberland. 
The  veins  of  galena  which  form  the  object  of  the  workings,  traverse  alternate  beds  of 
limestone  and  sandstone  ;  and  are  very  remarkable  for  their  becoming  suddenly  thin 
and  impoverished  on  passing  from  the  limestone  into  the  sandstone ;  and  for  resuming 
their  richness,  and  usual  size,  on  returning  from  the  sandstone  into  the  limestone.  The 
exploitations  are  situated  in  the  Aanks  of  considerably  high  hills,  bare  of  wood,  and 
almost  wholly  covered  with  marshy  heaths.  The  waters  are  drawn  off  by  galleries  of 
efflux ;  and  the  ores  are  dragged  out  by  horses  to  the  day.  The  galena  extracted  from 
these  mines  is  smelted  by  means  of  coal  and  a  little  peat,  in  furnaces  of  the  Scotch  con- 
struction. The  lead  is  very  poor  in  silver;  and  there  is  hardly  a  single  hearth  for  the 
purpose  of  eliminating  this  metal  by  cupellation.  The  mines  of  this  district  produce 
annually  17,200  tons  of  lead,  according  to  Mr.  Taylor's  statement,  published  in  the 
Geology  of  England  and  Wales,  by  Messrs.  Conybeare  and  Phillips.  There  is  more 
over  a  copper-mine  2  leagues  S.W.  of  Alston-Moor.  The  ore  is  a  copper  pyrites,  ac- 
companied with  galena  in  a  very  extensive  vein,  which  does  not  appear  to  belong  to 
the  same  formation  as  the  other  veins  of  this  region. 

The  second  metalliferous  district  lies  in  the  northern  part  of  Derbyshire,  and  in  the 
conterminous  parts  of  the  neighboring  counties.  The  districts  called  the  Peak  and 
King's-Field  are  the  richest  in  workable  deposites.  The  mines  of  Derbyshire  are 
getting  exhausted  ;  they  are  very  numerous,  but  in  general  inconsiderable.  The 
galena  extracted  fVom  them  is  treated  with  coal  in  reverberatory  furnaces;  but  the 
silver  is  not  sought  for.  They  yield  annually  900  tons  of  lead  ;  with  a  certain  quantity 
of  calamine,  and  a  little  copper  ore.  A  vein  of  copper  pyrites  occurs  at  Ecton,  in  Staf- 
fordshire, on  the  borders  of  Derbyshire.  The  veins  of  Derbyshire  are  famous  for  the 
beautiful  minerals  which  they  have  produced  ;  and  particularly  for  the  interruption  which 
they  almost  constantly  suffer  at  the  contact  of  the  trap-rock,  called  toadstone,  which  is 
intruded  among  the  limestone. 

The  third  metalliferous  distric .  is  situated  in  Flintshire  and  Denbighshire,  counties 
forming  the  N.E.  part  of  Wales.  Next  to  Alston-Moor  this  is  the  most  productive ; 
furnishing  annually  6,900  tons  of  lead,  and  a  certain  quantity  of  calamine.  The  galena 
is  smelted  in  reverberatory  furnaces,  and  affords  a  lead  far  from  rich  in  silver,  which  is 
therefore  bcldom  subjected  to  cupellation.  The  mines  occur  partly  in  the  metalliferoua 
limestone,  and  partly  in  several  more  ancient  rocks. 

To  the  S.E.  of  this  district  there  exist  stilJ  some  lead  mines  in  Shropshire.      They 


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MINES. 


MINES. 


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lie,  like  the  preceding,  partly  in  the  metoliiferons  limestone,  and  partly  in  the  subjacent 
rocks.     They  yield  annually  from  700  to  800  tons  of  lead. 

Some  mines  of  galena  and  calamine  are  mentioned  in  the  Mendip  hills,  to  the  south 
of  Bristol ;  but  they  seem  to  be  for  the  present  abandoned. 

Besides  the  metallic  mines  just  enumerated,  the  formation  of  the  metalliferous  lime- 
stone presents,  in  England,  especially  in  the  counties  of  Northumberland  and  Cumber* 
land,  several  coal  mines,  opened  on  coal  strata  included  by  the  sandstone,  which  alter* 
nates  with  the  limestone. 

MINES   OF   DAOURIA. 

The  name  Daouria  is  given  to  a  great  region  wholly  mountainous,  which  extends  from 
the  Baikal  Lake  to  the  eastern  ocean.  There  is,  perhaps,  no  other  country  in  the  world 
so  rich  in  deposites  of  lead  ores,  as  the  part  of  this  district  which  extends  from  the  junc- 
tion of  the  rivers  Chilca  and  Argoun,  whose  united  waters  form  the  river  Amour,  be- 
longing to  Russia.  The  mines  opened  here  constitute  the  third  arrondissement  of  the 
Siberian  mmes,  called  that  of  Nertchinsk,  from  the  name  of  its  capital,  which  lies  more 
than  1,800  leagues  east  of  Saint  Petersburg. 

The  ground  of  the  metalliferous  portion  of  Daouria  is  formed  of  granite,  horns- 
chiefer,  and  schists,  on  which  reposes  a  gray  limestone,  sometimes  siliceous  and  argil- 
laceous, which  contains  a  small  number  of  fossils,  and  in  which  the  veins  of  lead  occur. 
The  plains  of  these  regions,  often  salt  deserts,  exhibit  remarkable  sandstones  and 
pudding-stones  ;  as  also  vesicular  rocks  of  a  volcanic  aspect.  It  appears  that  the  metal- 
liferous limestone  is  much  dislocated,  and  the  lead  veins  are  subject  to  several  irregu- 
larities, which  render  their  exploitation  difficult  and  uncertain.  The  mines  lie  chiefly 
near  the  banks  of  the  Chilca  and  the  Argoun,  in  several  cantons,  at  a  considerable  dis- 
tance from  one  another ;  wherefore  it  was  requisite  to  build  a  great  number  of  smelt- 
ing furnaces.  The  want  of  wood  has  placed  difficulties  in  the  working  of  some  of 
them.  The  ore  is  galena,  sometimes  occurring  in  masses  of  several  yards  in  diameter; 
having  commonly  for  vein-stones  ores  of  iron  and  zinc,  of  which  no  use  is  made.  The 
galena  itself,  furnished  by  these  mines  in  enormous  quantities,  receives  a  very  different 
treatment  from  what  it  would  do  in  a  civilized  country ;  for,  though  the  lead  which  it 
produces  contains  only  from  6  to  10  gros  (1  to  Ij  ounce)  of  silver  per  quintal,  it  is  for 
it  alone  that  these  mines  are  worked.  The  litharge  produced  by  the  cupellation  is 
thrown  away  as  useless;  so  that  heaps  of  it  exist  near  the  smelting-furnaces,  says 
M.  Patrin,  higher  than  the  houses.  Only  an  insignificant  quantity  of  it  is  reduced  to 
lead  for  the  uses  of  the  country,  or  for  those  of  the  foundries  in  the  arrondissement  of 
Kolywan.  The  silver  extracted  from  the  mines  of  Daouria,  contains  a  very  small  pro- 
portion of  gold.  M.  Patrin  says  that  their  annual  product  was,  toward  the  year  1784, 
from  30,000  to  35,000  marcs  of  silver.  The  exploitation  of  some  of  the  mines  of 
Daouria  goes  back  to  the  end  of  the  17th  century.  It  has  been  commenced  in  some 
points  by  the  Chinese,  wh»  were  not  entirely  expelled  from  this  territory  till  the  be- 
ginning of  the  following  century.  A  great  part  of  the  mines,  however,  has  been  opened 
up  since  1760. 

Besides  the  lead  mines,  there  are  some  unimportant  mines  of  copper  in  Daouria,  and 
in  different  explorations  of  this  region,  arsenical  pyrites,  from  which  arsenious  acid  is 
sublimed  in  factories  established  at  Jutlack  and  at  Tchalbutchinsky. 

About  45  leagues  to  the  south  of  Nertchinsk,  the  mountain  of  Odon-Tchelon  occurs, 
celebrated  for  the  different  gems  or  precious  stones  extracted  from  it.  It  is  formed  of 
a  friable  granite,  including  harder  nobules  or  balls  which  enclose  topazes ;  it  is  very 
analogous  to  the  topaz  rock  of  Saxony.  In  this  granite  there  are  several  veins  filled 
with  a  ferruginous  ciay,  which  contains  a  great  quantity  of  wolfram,  and  many  emeralds, 
aqua-marines,  topazes,  crystals  of  smoked  quartz,  &c.  Multitudes  of  these  minerals 
have  been  extracted  by  means  of  some  very  irregular  workings.  The  mountain  of 
Toutt-Kaltoui,  situated  near  the  preceding,  offers  analogous  deposites.  The  presence 
of  wolfram  had  excited  hopes  that  tin  might  be  found  in  these  mountains;  hopes  which 
have  not  hitherto  been  realized.  There  are  some  unworked  deposites  of  sulphuret  of 
antimony  in  this  country. 

ON    SOME    OTHER    LESS    KNOWN   MINE    COUNTRIES. 

There  seem  to  exist  in  Brazil,  besides  the  washings  of  the  sands  that  produce  the 
diamonds,  the  precious  stones,  the  platinum,  and  almost  all  the  gold  of  this  country, 
gome  mines  of  gold,  lead,  and  iron,  opened  up  in  very  ancient  geological  formations ; 
but  there  is  no  silver  mine,  which  indicates  a  great  difference  between  the  metalliferous 
deposites  of  this  district  and  those  of  Spanish  America.  The  lead  mines  occur  particu- 
larly in  the  captainry  of  Minas-Geraes,  canton  of  Abaite.  Their  exploitation  has 
been  undertaken  within  a  few  years.  The  captainry  of  Minas-Geraes  contains 
extremely  abundant  deposites  of  black  oxide  of  iron,  and  specular  iron,  which  constitute 
beds  or  enormous  masses,  forming  sometimes  entire  mountains;  along  with  numerous 


veins  of  hematite  and  red  oxide  of  iron.  Lately  these  have  been  opened  np,  and  smelt- 
ing-houses  have  been  established  at  Gaspar-Saarez.  There  are  also  iron  mines  and 
foundries  in  the  captainry  of  Saint-Paul.  A  mine  of  antimony  occurs  near  Sahara,  in 
the  captainry  of  Minas-Geraes. 

In  Africa,  the  inhabitants  of  the  countries  adjoining  to  the  cape  of  Good  Hope  mine 
and  smelt  copper  and  iron ;  and  the  Congo  produces  considerable  quantities  of  these 
two  metals.  It  is  asserted  that  a  great  deal  of  copper  exists  in  Abyssinia.  On  the 
banks  of  the  Senegal  the  Moors  and  the  Pouls  fabricate  iron  in  travelling  forges.  They 
employ  as  the  ore  the  richest  portions  of  a  ferruginous  sandstone,  which  seems  to  be  a 
very  modern  formation.  Lastly,  the  kingdoms  of  Morocco  and  Barbary  appear  to  in- 
clude several  copper  and  iron  mines. 

The  islands  of  Cyprus  and  Negropont,  in  the  Mediterranean,  were  celebrated,  in  for- 
mer times,  for  their  copper  mines ;  and  several  islands  of  the  Archipelago  presented 
gold  mines,  now  abandoned.  The  same  thing  may  be  said  of  Macedonia  and  Thrace. 
The  mountains  of  Servia  and  Albania  contain  iron  mines;  and  lead  mines  occur  in 
Servia.  Natolia  possesses  iron  and  copper  mines  in  the  neighborhood  of  Tokat.  Some 
also  occur  in  Arabia  and  in  Persia ;  and  in  the  territories  round  Caucasus,  the  kingdom 
of  Imeretta  is  distinguished  for  its  iron  mines.  The  celebrity  of  the  Damascus  sabres 
attests  the  good  quality  of  the  products  of  some  of  the  mines.  Persia  includes,  besides, 
mines  of  argentiferous  lead  at  Kervan^  a  few  leagues  from  Ispahan ;  and  Natolia  fur- 
nishes orpiment. 

Some  iron  and  copper  mines  have  been  mentioned  in  Tartary.  Thibet  passes  for  be- 
ing rich  in  gold  and  silver  mines.  China  produces  a  great  quantity  of  iron  and  mercu- 
ry, as  well  as  white  brass  {tombac),  which  is  much  admired.  The  copper  mines  of  this 
empire  lie  principally  in  the  province  of  Yu  Nan  and  the  island  of  Formosa.  Japan, 
likewise,  possesses  copper  mines  in  the  provinces  of  Kijunack  and  Sarunga.  They  seem 
to  be  abundant ;  at  a  period  not  far  back,  they  exported  their  products  to  Europe.  Jap- 
an presents,  moreover,  mines  of  quicksilver.  China  and  Japan  contain  also  mines  of 
gold,  silver,  tin,  red  sulphuret  of  arsenic,  &c.  Large  deposites  of  the  latter  ore  (realgar) 
are  said  to  occur  in  the  tin  mine  of  Kian-Fu,  in  China.  But  in  that  empire,  as  in  Eu- 
rope, coal  is  the  mbst  important  of  the  mining  products.  This  combustible  is  explored, 
especially  in  the  environs  of  Pekin,  and  in  the  northern  parts  of  the  empire. 

Iron  mines  exist  in  several  points  of  the  Burman  empire,  and  of  Hindostan.  Near 
Madras  there  exist  excellent  ores  of  sparry  iron,  and  black  oxide,  analogous  to  the  Swe- 
dish ores.  The  Indian  natural  steel,  named  Wootz,  has  been  held  in  considerable  esti- 
mation among  some  eminent  London  cutlers ;  but  the  iron  and  steel  recently  manufac- 
tured upon  a  great  scale,  near  Madras,  by  Messrs.  Heath  and  Co.,  from  the  crystallized 
magnetic  ore  of  that  country,  will  probably  ere  long  rival,  and  eventually  supersede  in 
Europe  the  product  of  the  Dannemara  forges.  The  islands  of  Macassar,  Borneo,  and  Ti- 
mor, include  copper  mines.  As  to  the  tin  obtained  from  the  island  of  Banca,  from 
the  peninsula  of  Malacca,  and  several  other  points  of  southern  Asia,  it  proceeds  entirely 
from  the  washing  of  sands.  The  same  is  undoubtedly  true  of  the  gold  furnished  by 
the  Pi  ilippine  isles,  Borneo,  &c.  It  appears,  however,  that  mines  of  gold  and  silver 
are  worked  in  the  island  of  Sumatra. 

MINES   OF  THE   SECONDARY   ROCK   FORMATIONS. 

The  most  important  mines  of  the  secondary  rocks,  and  perhaps  of  all  minerals  what- 
soever, are  those  worked  in  the  most  ancient  of  these  strata,  in  the  coal-measures. 

The  British  islands,  France,  and  Germany,  present  several  groups  of  small  mountains 
primitive  on  the  ridge,  and  transition  on  the  flanks ;  in  the  sinuosities  between  which 
deposites  of  coal  occur.  The  principal  of  these  have  become  great  centres  of  manufac- 
tures ;  for  Glasgow,  Newcastle,  Sheffield,  Birmingham,  Saint-Etienne,  &c.,  owe  their 
prosperity  and  their  rapid  enlargement  to  the  coal,  raised,  as  it  were,  at  their  gates  in 
enormous  quantities.  Wales,  Flanders,  Silesia,  and  the  adjacent  parts  of  Gallicia,  owe 
equally  to  their  extensive  collieries  a  great  portion  of  their  activity,  their  wealth,  and 
their  population.  Other  coal  districts,  less  rich,  or  mined  on  a  less  extended  scale,  have 
procured  for  their  inhabitants  less  distinguished,  but  by  no  means  inconsiderable,  ad- 
vantages ;  such,  for  examples  in  Great  Britain,  are  Derbyshire,  Cheshire,  Lancashire, 
Shropshire,  Warwickshire,  the  environs  of  Bristol  &c. ;  some  parts  of  Ireland ;  ia 
France,  Litry  department  of  Calvados,  Comanterie,  Saint-Georges-Chatelaison,  Aubin, 
Alais,  le  Creusot ;  Ronchamps,  in  the  Prussian  provinces  of  the  lefl  bank  of  the  Rhine; 
the  environs  of  Saarebriick;  several  points  of  the  north  of  the  territory  of  Berg  and  La- 
marck, of  Mansfeld,  of  Saxony,  Hungary,  Spain,  Portugal,  the  United  States,  &c. 

We  need  not  enter  here  into  ampler  details  on  coal  mines,  reserving  these  particulars 
for  the  article  Pitcoal. 

Nature  has  deposited  alongside  of  coal  an  ore  whose  intrinsic  value  alone  is  very 
small,  but  whose  abundance  in  the  neighborhood  of  fuel  becomes  extremely  precious  to 


si!  .     ( 


r    ( 


222 


MINES. 


MORTAR,  HYDRAULIC. 


223 


11 


man ;  we  allude  to  the  clay-ironstone  of  the  coal-measures.  It  is  extracted  in  enor- 
mous quantities  from  the  coal-basins  of  Scotland,  Yorkshire,  Staffordshire,  Shropshire; 
and  South  Wales. 

Much  of  it  is  also  raised  from  the  coal  strata  of  Silesia ;  and  the  French  entertain 
hopes  of  finding  a  supply  of  this  necessary  ore  in  their  own  country.  The  iron-worki 
of  England,  which  are  supplied  almost  entirely  from  this  iron-stone  reduced  with  the 
coke  or  coal,  pour  annually  into  commerce  more  than  one  million  tons  of  cast  and  bar 
iron,  the  value  of  which  has  been  estimated  at  eight  millions  sterling;  an  amount  fully 
equal  to  the  product  of  all  the  mines  of  Spanish  America. 

The  shale  or  slate-clay  of  the  coal-measures  contains  sometimes  a  very  large  quan- 
tity of  pyrites,  which,  decomposing  by  the  action  of  air,  with  or  without  artificial  heat, 
produces  sulphate  of  iron  and  sulphate  of  alumina ;  whence  copperas  and  alum  are 
manufactured  in  great  abundance. 

The  lead  mines  of  Bleyberg  and  Gemund,  near  Aix-la-Chapelle,  are  explored  in  a 
sandstone  referred  by  many  geologists  to  the  red  sandstone.  The  ore  consists  princi- 
pally of  nodules,  of  galena  disseminated  in  this  rock.  They  are  very  abundant,  and  of 
very  easy  exploration.  These  mines  produce  annually  from  700  to  800  tons  of  lead, 
which  does  not  contain  silver  in  sufficient  proportion  to  be  worth  the  extractmg.  2,000 
tons  of  ore  are  prepared  and  sold  in  the  form  of  black  lead  dust  {alqui/oux). 

The  manganese  mines  worked  in  the  open  air  near  Exeter,  in  England,  occur  in  a 
sandstone  analogous  to  the  red. 

The  calcareous  formation  which  surmounts  the  coal-sandstone,  called  by  geologists 
zechstein,  magnesian  limestone,  and  older  alpine  limestone,  contains  different  deposites  of 
metallic  ores;  the  most  celebrated  being  the  cupreous  schist  of  Mansfeldt,  a  stratum  of 
calcareous  slate  from  a  few  inches  to  two  feet  thick,  containing  copper  pyrites  in  suffi- 
cient quantity  to  aflord  2  per  cent,  of  the  weight  of  the  ore  of  an  argentiferous  copper. 
This  thin  layer  displays  itself  in  the  north  of  Germany  over  a  length  of  eighty  leagues, 
from  the  coasts  of  the  Elbe  to  the  banks  of  the  Rhine.  Notwithstanding  its  thinness 
and  relative  poverty,  skilful  miners  have  contrived  to  establish,  on  different  points  of 
this  slate,  a  number  of  important  explorations,  the  most  considerable  being  in  the  terri- 
tory of  Mansfeldt,  particularly  near  Rottenburg.  They  produce  annually  2,000  tons  of 
copper,  and  20,000  marcs  of  silver.  We  may  also  mention  those  of  Hessia,  situated 
near  Frankenberg,  Bieber,  and  Riegelsdorf.  In  the  latter,  the  cupreous  schist  and  its 
accompanying  strata  are  traversed  by  veins  of  cobalt,  mined  by  the  same  system  of  un- 
derground workings  as  the  schist.  These  operations  are  considerable ;  they  extend,  in 
the  direction  of  the  strata,  through  a  length  of  8,700  yards,  and  penetrate  downward  to 
a  very  great  depth.  Three  galleries  of  efflux  are  to  be  observed  ;  two  of  which  pour 
their  waters  into  the  Fulde,  and  the  third  into  the  Verra.  One  of  them  runs  about  20 
yards  below  the  most  elevated  point  of  the  workings.  These  mines  have  been  in  ac- 
tivity since  the  year  1530.     Analogous  mines  exist  near  Saalfeld,  in  Saxony. 

To  the  same  geological  formation  must  probably  be  referred  the  limestone  which  con- 
tains the  sparry  iron  mine  of  Schmlacalden,  at  the  western  foot  of  Thuringerwald, 
where  there  has  been  explored  from  time  immemorial  a  considerable  mass  of  this  ore 
known  by  the  name  of  Stahlberg.  The  working  is  executed  in  the  most  irregular  man- 
ner, and  has  opened  up  enormous  excavations;  whence  disastrous  ruins  have  taken 
place  in  the  mines.  It  furnishes  annually  4,500  tons  of  ore,  which  keep  in  play  a  great 
number  of  furnaces,  where  a  deal  of  iron  and  steel  is  manufactured. 

At  Tarnowitz,  14  leagues  S.E.  of  Oppeln,  in  Siberia,  the  zechstein  contains,  in  some 
of  its  strata,  considerable  quantities  of  galena  and  calamine;  into  which  mines  have 
been  opened,  that  yield  annually  from  600  to  700  tons  of  lead,  :',000  to  1,100  marcs  of 
silver,  and  much  calamine.  Mines  of  argentiferous  lead  are  noticed  at  Olkutch  and 
Jaworno,  in  Gallicia,  about  6  leagues  N.E.  of  Cracow,  and  15  leagues  E.N.E.  of  Tarno- 
witz. Their  position  seems  to  indicate  that  they  belong  to  the  same  formation ;  and 
possibly  those  of  Willach  and  Bleyberg  in  Carinthia  have  the  same  locality. 

There  has  been  discovered  lately  near  Confoknsy  in  the  department  of /a  Charente,m 
a  secondary  limestone,  calcareous  beds,  and  particularly  subordinate  beds  of  quartz, 
which  contain  considerable  quantities  of  galena.  At  Figeac  also,  in  the  department  of 
le  Lot,  deposites  of  galena,  blende,  and  calamine,  occur  in  a  secondary  limestone.  Al 
la  Voulte,  on  the  banks  of  the  Rhone,  there  is  mined,  in  the  lower  courses  of  the  lime- 
stones that  constitute  a  great  portion  of  the  department  of  the  Ardeche,  a  powerful  bed 
of  iron  ore. 

It  is  in  the  zechstein,  or  in  the  sandstones,  and  trap  rocks  of  nearly  the  same  age, 
that  the  four  great  deposites  of  the  sulphuret  of  mercury,  of  Idria,  the  Palatinate^  jSl- 
maderiy  and  Huancavelica,  are  mined. 

The  formation  which  separates  the  zechstein  from  the  lias  (calcaire  a  gryphites),  called 

"new  red  sandstone  and  red  marl  in  England,  and  bunter-sandstein,  muschelkalk,  and 

quadersandstein.  in  Germany,  presents  hardly  any  important  mines  except  those  of  rock 


gait ;  which  enrich  it,  not  only  in  the  centre  of  Europe,  as  in  Cheshire,  at  Vic,  Wieliczka, 
Bochnia,  and  Salzbourg,  but  in  many  other  parts  of  the  world. 

The  lias  contains  often  very  pyritous  lignites,  which  are  mined  in  many  places,  and 
particularly  at  Whitby  and  Guisborough  in  Yorkshire,  for  the  manufacture  of  alum  and 
copperas. 

The  oolitic  limestones  contain  strata  of  iron  ore,  which  are  mined  in  some  districts  of 
France. 

The  iron  sand  (Hastings  sand)  beneath  the  chalk  formation,  is  often  so  strongly  im- 
bued with  iron  as  to  be  worth  the  working. 

The  lowest  beds  of  the  chalk  contain  iron  pyrites,  which  has  become  the  object  of  an 
important  exploration  at  Vissans,  on  the  southern  coast  of  the  Pas-de-Calais,  where  it  is 
converted  into  sulphate  of  iron.  The  waves  turn  the  nodules  out  of  their  bed,  and  roll 
them  on  the  shore,  where  they  are  picked  up. 

If  the  chalk  be  poor  in  useful  minerals,  this  is  not  the  case  with  the  plastic  clay  for- 
mation above  it ;  for  it  contains  important  mines.  In  it  are  explored  numerous  beds 
of  lignite  (wood-coal),  either  as  fuel  or  a  vitriolic  earth.  From  these  lignite  deposites, 
also,  the  yellow  amber  is  extracted. 

The  other  tertiary  formations  present  merely  a  few  mines  of  iron  and  bitumen. 

Several  of  the  secondary  or  tertiary  strata  contain  deposites  of  sulphur,  which  are 
mined  in  various  countries. 

The  formations  of  a  decidedly  volcanic  origin  afford  few  mining  materials,  if  we  ex- 
cept sulpliur,  alum,  and  opals. 

MINES   OF   THE   ALLUVIAL    STRATA. 

This  formation  contains  very  important  mines,  since  from  it  are  extracted  all  the  dia- 
monds, and  almost  all  the  precious  stones,  the  platinum,  and  the  greatest  part  of  the  gold, 
with  a  considerable  portion  of  the  tin  and  iron.  The  diamond  mines  are  confined  nearly 
to  Brazil,  and  to  the  kingdoms  of  Golconda  and  Visapour  in  the  East  Indies. 

MINES,  VENTILATION  OF.  The  means  adopted  in  the  South  Staffordshire 
coal  mines,  which  haye  veins  varying  from  25  to  30  feet  in  thickness,  are  well  worthy  of 
consideration ;  since  a  solid  mass  of  that  magnitude  must  be  peculiarly  difficult  to  drain 
of  its  imprisoned  gas.  In  excavating  such  coal  large  masses  must  be  detached,  and 
pockets  or  hollows  must  be  formed,  which  are  immediately  filled  with  carburetted  hy- 
drogen: whilst  a  thin  vein,  for  which  a  level  roof  can  generally  be  secured,  can  be 
kept  tolerably  free  from  such  accumulations. 

In  December,  1846,  in  consequence  of  a  frightful  explosion  which  took  place  at  Old- 
bury,  Mr.  Benjamin  Gibbons  was  induced  to  publish  a  small  work  descriptive  of  the 
principles  of  ventilation  adopted  and  practised  by  him  for  many  years  before  in  the 
thick  and  thin  mines  that  were  worked  under  his  personal  supenntendence. 

The  author  first  recapitulates  the  substance  of  «  part  of  his  work,  and  gives,  in  addi- 
tion, the  results  of  an  enlarged  experience,  as  well  as  a  slight  notice  and  reply  to  some 
of  the  objections  made  to  his  plan. 

Carburetted  hydrogen  gas,  which  produces  these  dreadful  explosions,  is  not  explosive 
until  it  is  united  with  a  certain  proportion  of  ordinary  air,  say  seven  to  nine  times  its 
volume ;  when  this  mixture  has  taken  place,  it  arrives  at  what  is  termed  its  "  firing  "  or 
explosive  point;  and  in  that  state,  if  it  come  in  contact  with  the  flame  of  a  candle,  it 
will  instantly  explode,  with  similar  rapidity  and  violence  to  gunpowder.  A  consider* 
able  volume  of  this  gas  is  set  at  liberty  in  all  the  thick  coal  mines,  when  worked  in  the 
usual  manner,  and  ns  often  as  fresh  masses  of  coal  are  cut  through.  Some  coal  mines 
supply  a  much  greater  quantity  of  gas  than  others,  and  these  are  commonl}^  called 
"fiery  mines  ;"  but,  in  all  coat  mines,  a  sufficient  quantity  is  extracted  to  produce  the 
most  direful  consequences,  if  it  be  not  neutralized,  or  its  escape  duly  provided  for. 

The  general  mode  is  that  of  diluting  the  gas  with  a  quantity  of  atmospheric  air ;  and 
a  current  of  air  equal  to  thirty  times  the  volume  of  gas  yielded  by  the  coal,  is,  in  the 
author's  Of)inion,  the  bare  limit  of  safetj^ :  that  is  to  say,  tbirty  cubic  feet  of  common  air 
must  circulate  through  the  mine  in  the  space  of  time  that  the  coal  will  give  out  one 
cubic  foot  of  gas;  but  the  quantity  of  air  should  exceed  this,  where  this  mode  of  ven- 
tiiation  is  practised ;  for  a  copious  supply  of  fresh  air  is  needful  for  the  numerous  work- 
men, horses,  and  candles,  employed  in  the  pit. 

Many  mechanical  plans  have  been  recommended  to  increase  the  current  ofair  through 
the  mines  ;  in  soir-e,  force  pumps,  and  in  others,  exhaust  pumps,  have  been  proposed,  to 
produce  an  artificial  current  ofair  throughout  tlie  workings.  These  plans,  theoretically, 
may  be  very  correct,  but,  it  is  to  be  observed,  that  the  current  of  air  must  be  constnntly 
maintained;  and  in  the  practical  application,  the  engine  that  works  these  pumps,  or 
other  mechanical  means,  may  get  out  of  order,  and  thereby  endanger  the  lives  of 
all  the  miners.  This  fatal  objection  attaches  to  all  mechanical  plans  of  ventilation; 
and,  indeed,  to  all  artificial  modes,  where  the  power  of  ventilation  is  not  self-acting, — 


224 


MIKES,  VENTILATION  OF. 


u 


Iji 


but  requires  the  constant  action  of  machinery,  or  the  constant  aid  of  men ;  even  includ- 
ing the  ordinary  plan  of  rarefaction  of  the  air  by  a  separate  fire,  which  may  be  out 
when  it  ouy;ht  to  be  in,  and  ought  not  to  be  relied  upon  as  the  sole  protector,  though 
it  will  be,  in  some  circumstances,  a  useful  auxiliary. 

We  should  therefore  avail  ourselves,  as  far  as  possible,  of  the  natural  powers  that  are 
at  our  command ;  and,  in  this  instance,  the  extreme  levity  of  the  gas  from  which  we 
wish  to  rid  the  mines,  supplies  us,  to  a  considerable  extent,  with  the  remedy  required. 
But  cases  may  arise  where  other  auxiliaries  may  be  temporarily  required,  from  acci- 
dental misplacements  of  the  level  of  the  mine  ;  although,  in  the  author's  opinion,  these 
cases  may  be  reduced  to  a  few,  if  the  mines  are  opened  out  and  worked  upon  a  proper 
system,  as  will  be  further  noticed  in  this  paper.  Under  these  circumstances,  it  may 
be  necessary  to  employ  heat,  to  rarefy  the  upcast  current  of  air,  to  make  it  specifically 
lighter  than  the  downcast ;  or  mechanical  means  to  force  aii-  in,  or  to  extract  air  from 
the  mines,  may  be  required.  Where  artificial  heat  is  made  use  of,  a  steam-jet,  from 
the  boiler  of  the  windmg-engine,  is  the  most  secure  method ;  because,  the  steam  being 
supplied  from  the  boiler  of  the  winding-engine,  it  is  clear  that  the  steam  is  always  at 
command  whilst  the  pit  is  at  work.  If  mechanical  means  should  become  necessary, 
Mr.  Struve's  exhausting  cylinders  supply  the  most  powerful  and  effective  apparatus 
that  has  fallen  under  the  author's  notice. 

The  object  of  the  present  paper  is  to  show  that  there  is  a  constant  self-acting  power 
available,  which  experience  has  shown  will  afford  the  desired  protection  in  ordinary 
temperatures,  in  the  majority  of  cases;  because  the  caiburetted  hydrogen  of  the  mines 
being  half  the  weight  of  common  air  (it  has  an  equal  ascending  power  to  common  air 
heated  to  512°,  being  of  the  same  specific  gravity),  will  rise  to  the  highest  parts  of  the 
mine,  and  would  escape  with  great  velocity,  if  permitted  to  do  so ;  forming,  in  the  ag- 
gregate, a  very  large  ascendin]^  power,  as  exem[»lified  in  the  balloon;  but,  in  the  or- 
dinary system  of  working,  this  escape  is  unprovided  for,  indeed,  absolutely  prevented. 

According  to  the  ordinary  system  adopted  in  the  collieries  of  this  district,  two  shafts 
are  sunk,  near  together,  about  7  to  7i  feet  in  diameter,  each  to  the  bottom  of  the  coal, 
say  about  180  yards  depth,  the  two  shafts  commencing  at  the  same  level,  and  terminat- 
ing at  the  same  level.  One  of  these  becomes  the  "  downcast  pit "  down  which  the  air 
descends,  and  the  other  the  "upcast  pit"  up  which  the  air  ascends,  when  a  communi- 
cation is  made  between  them  at  the  bottom ;  but  the  only  determining  causes  for  the 
motion  of  the  air  being  accidental,  it  is  unknown  beforehand  what  direction  the  current 
will  take,  and  which  will  become  the  downcast  pit  It  is  generally  found  that  a  cur- 
rent of  air  does  take  place  (it  may  almost  be  said  always  takes  place),  without  any 
other  means  being  employed  ;  but  the  determining  power  is  so  faint,  that,  issuing  from 
the  upcast  pit  with  such  trifling  velocity,  it  is  liable  to  be  deranged  by  the  action  of 
the  wind,  or  by  atmospheric  changes ;  and  it  sometimes  happens  that  the  air  becomes 
quiescent,  or  an  unsteady  column,  alternately  ascending  and  descending  the  same 
shaft ;  and  then,  in  miner  s  language,  the  pits  "  fight,"  and  the  air  will  neither  ascend 
nor  descend  with  regularity  in  one  direction.  But  worst  of  all,  the  course  of  the  air 
will  be  sometimes  inverted  or  "turned" — that  which  should  be  the  downcast  pit  be- 
coming the  upcast;  and  the  mine  then  becomes  exposed  to  the  most  fearful  results, 
where  the  workings  have  been  opened,  by  the  air  being  driven  backwards  along  the 
air-head  into  the  reservoirs  of  gas  formed  in  the  upper  cavities  of  the  workings,  and 
issuing  into  the  gate-road,  chaining  the  gas  to  the  firing  point 

The  danger  of  this  change  in  the  direction  of  the  air  current  is  increased  by  the  up- 
cast pit  being  used  as  a  working  shaft.  The  upcast  pit  (which  is,  in  fact,  the  main  gas 
and  air-way,  and  which  ought  always  to  be  closed  from  the  external  air,  and  the  as- 
cending air  current  guarded  from  disturbance  or  commotion,  to  prevent  the  slightest 
interruption  to  the  current  of  air  upon  which  the  lives  of  all  depend)  is  kept  in  a  state 
of  constant  agitation  by  the  ascent  and  descent  of  the  "skips,"  loaded  with  coal,  which 
nearly  fill  the  shaft  To  crown  this,  when  every  skip  arrives  at  the  top  of  the  shafts 
a  carriage,  boarded  over,  called  the  "  runner,"  is  wheeled  over  the  mouth  of  the  pit 
whilst  the  coal  is  landed,  and  then  withdrawn  to  allow  the  skip  to  descend-  It  is  ob- 
vious that  the  air,  which  should  never  be  disturbed,  is  thus  constantly  liable  to  be  in 
conflicting  currents,  more  or  less,  sometimes  upwards  and  sometimes  downwards  ;  and 
whenever  the  mouth  of  the  shaft  is  covered  by  the  runner,  the  air  is  in  a  state  of  par 
tial  stagnation.  But  it  sometimes  occurs  that  the  chain  or  tackle,  by  which  the  skin 
is  suspended,  breaks  during  the  ascent  of  the  upcast  shaft;  the  skip  then  drops  down 
the  shaft,  drives  the  air  before  it  with  great  velocity  along  the  air-head,  and  forces  the 
gas  out  of  the  cavities  into  the  workings,  down  upon  the  candles  of  the  workmen ;  ana 
this  the  author  has  known  to  happen  many  times. 

When  the  two  pits  are  sunk  down  through  the  stratum  of  coal  30  ft.  in  thickness,  t 
"gate-road"  or  horse-way  is  next  driven  in  the  bottom  of  the  coal,  from  8  to  9  ft  higli, 
and  about  the  same  width,  commencing  from  the  bottom  of  the  downcast  pit 


^;ii 


MINES,  VENTILATION  OF. 


225 


r'  At  the  same  time,  (or  rather  before,  as  it  should  always  precede  the  gate  road)  an  aii^ 
head  is  driven  about  the  middle  of  the  coal,  or  15  ft.  high  from  the  "floor"  or  bottom 
of  the  coal,  commencing  from  the  downcast  pit  The  gate-road  and  air-head  are  then 
driven  in  parallel  lines,  at  the  same  level  upon  which  they  commence,  for  the  distance 
of  100  to  600  yards,  or  more,  according  to  the  quantity  of  coal  intended  to  be  cleared 
by  the  pits. 

A  series  of  "  spouts  "  or  openings  are  driven  upwards  from  the  gate-road  into  the  air- 
head, at  intervals  of  10  or  15  yards  (as  the  coal  may  give  out  more  or  less  gas)  to  carry 
off  the  gas,  and  produce  a  current  of  air  for  the  workmen, — each  spout  being  closed  up 
when  a  new  one  is  made  in  advance.  The  excavation  of  the  whole  thickness  of  the 
stratum  of  coal,  30  ft.  thick,  is  then  proceeded  with,  by  opening  right  and  left  from  the 
end  of  the  gate-road,  and  excavating  a  "  side  of  work,"  which  forms  a  rectantfular  cavity, 
say  about  90  yards  long  by  60  yards  wide,  or  about  an  acre,  the  whole  of  the  coal  be- 
ing taken  away  as  far  as  practicable,  excepting  the  pillars  of  coal  (generally  10  yards 
square  and  10  j'^ards  distant  from  each  other),  whicli  are  left  to  support  the  superin- 
cumbent strata. 

The  air  descending  the  downcast  pit,  and  travelling  along  the  gate-road  into  the 
workings,  ascends  to  the  air-head,  and,  traversing  that,  ascends  the  upcast  pit,  carry- 
ing with  it  the  gas  and  impure  vapors,  as  far  as  such  imperfect  and  interrupted  means 
will  effect,  and  delivering  them  into  the  open  air. 

By  this  plan  we  may  contrive  (where  the  sj'stem  is  adopted)  to  ventilate  the  mine, 
though  imperfectly,  until  the  lower  15  feet  of  the  coal  is  excavated ;  but  where  the  whole 
thickness  of  the  coal  above  the  air-head  has  been  removed,  by  undergoing  the  coal  from 
the  bottom,  and  dropping  it  down  in  large  masses,  the  upper  portion  of  the  cavity,  being 
above  the  level  of  the  air-head,  forms  a  reservoir  for  gas,  which  gradually  accumulates, 
and  has  no  means  of  escape, — a  reservoir  of  the  capacity  of  some  hundred  thousand 
of  cubic  feet,  which  may  be  wholly  or  in  part  occupied  by  gas.  An  accidental  change 
in  the  direction  of  the  current  of  air  would  turn  the  course  of  the  air  along  the  air-head 
into  this  reservoir  of  gas,  and  from  thence  into  the  gate-road,  and  render  an  explosion 
very  prol>able.  After  the  coal  is  extracted,  a  solid  wall  or  "  rib  "  of  coal,  from  6  to  10 
yards  thick,  which  is  commonly  termed  a  "  fire-rib,"  is  left  all  round  the  chamber,  sepa- 
rating  it  from  the  next  workings;  and  the  entrance  from  the  gate-road  is  securely 
walled  up,  to  exclude  the  air,  and  prevent  spontaneous  combustion,  which  would 
otherwise,  in  a  short  period,  take  place.  When  an  explosion  occurs,  it  is  generally 
followed  by  a  second,  or  more,  as  proportions  of  the  gas  become  successively  charged 
with  the  due  proportions  of  air ;  and  the  liability  to  these  terrible  explosions  will 
always  remain  in  mines  thus  worked,  till,  by  some  efficient  means,  the  gas  can  be 
allowed  a  continuous  escape,  and  a  current  of  air  can  be  insured  to  move  always  in 
one  direction,  with  sufficient  power  to  overcome  all  extraneous  disturbing  forces,  either 
of  the  wind  or  any  atmospheric  changes. 

In  Jiff.  971,  the  system  adopted  and  carried  into  operation  by  the  author  is  shown. 
One  pit  a,  is  sunk,  instead  of  two;  and  in  the  side  of  the  shaft  a  smaller  shaft  6  is  cut, 
to  form  an  "air  chimney,"  and  is  afterwards  separated  from  the  main  shaft;  this  air 
chimney  is  circular,  and  may  be  made  about  3  feet  diameter  inside,  or  more,  as  may  be 
required.  The  air-chimney  is  bricked  at  the  same  time  with  the  shaft, — the  circular 
brickwork  of  each  forming  a  partition  of  double  thickness  and  secure  strength,  from 
the  two  arches  abutting  against  each  other. 

971  972 


"^^^M^s^^ 


i 


The  gate-road  c,  is  driven  from  the  shaft  at  the  bottom  of  the  coal,  as  in  the  ordinary 
plan ;  but  the  air-head  d  is  driven  from  the  air  chimney  within  2  feet  of  the  top  of 
the  coal,  or  higher  if  practicable,  and  runs  into  the  vertical  air  chimney.  The  gate- 
road  and  air-head  are  carried  forward  in  a  parallel  direction  to  the  extent  of  the  -vork, 

Vol.  XL  16 


If 


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'■[' 


226 


MINES,  VENTILATION  OF. 


as  before  described  in  the  ordinary  system  ;  and  "  spyonts  **  01  openings,  e,  are  driven 
tipwards,  to  connect  them  at  about  every  15  yards — every  spout  being  bricked  up  close, 
in  succession,  when  a  fresh  one  is  made  in  advance,  so  as  to  make  the  current  of  air 
traverse  tlie  wliole  extent  of  tlie  gate-road  before  it  rises  up  to  the  air-head  and  passe* 
aw.iv  to  the  air  chimney.  These  spouts  can  only  be  driven  perpendicularly  upwards 
from  the  gate-road  to  the  air-head  ;  and  each  of  them  being  about  18  feet  long  in  the 
30  feet  coal,  a  formidable  practical  difficulty  was  experienced  by  the  author  in  the  King 
Swinford  pits,  where  the  coal  being  contiguous  to  a  great  vault,  it  abounded  in  gas  to  so 
grciit  a  degree  that  when  a  spout  was  carried  up  a  very  few  feet,  it  became  so  filled 
wi  h  gas  tliat  no  man  could  work  in  it.  But  this  difficulty  was  overcome  by  boring 
upwards  fr<.m  the  spout  a  hole,  4  inches  in  diameter,  into  the  air-head;  the  gas  then 
passed  otf  instantly,  followed  by  a  stream  of  air  sufficient  to  ventilate  the  gate-road, 
ind  to  enable  the  men  to  work  with  candles  in  the  spout  with  perfect  safety. 

The  excavation  of  the  coal  is  commenced  in  the  same  manner  as  in  the  ordinaiT 
system,  by  driving  at  right  angles  from  the  end  of  the  gate-road,  to  begin  a  "side  of 
work ;"  and  ihe  ventilation  is  carried  on  completely  and  continuously  from  the  extremity 
of  the  working,  whilst  the  whole  of  the  coal  to  the  top  is  removed.  The  whole  of  the 
gan  is  constantly  drained  off  from  the  upper  surface  of  the  coal  by  the  air-head,  and  the 
numerous  spouts  or  cross  drains,  which  remain  all  open  to  the  air-hea  1,  by  means  of  a 
small  pipe-hole  left  in  the  stopping  as  they  are  successively  stopped,  and  which  constantly 
drain  otf  the  gas  most  effectually,  by  piercing  through  and  cutting  the  horizontal  layei-s 
of  coal,  and  thus  tapping  the  several  strata  at  so  many  different  points.  By  this  system 
the  danger  of  any  accumulation  of  gas  in  the  cavities  of  the  upper  part  of  the  workings 
is  effectually  prevented.  .  ,     j 

In  the  ordinary  system  of  ventilation,  it  is  manifest  that  only  a  very  slight  determming 
power  compels  the  air  to  travel  constantly  in  the  same  direction.  Its  current  is,  at  all 
times,  weak  and  insufficient,  and  liable  to  be  deranged  by  the  action  of  the  wind,  or  at- 
mospheric changes ;  and  it  is  under  no  command  whatever.  To  ensure  safety,  a  constant 
current  of  air  is  indispensably  necessary;  it  should  be  a  current,  too,  maintained  by 
natural  causes,  as  far  as  possible,  and  never  interrupted,  for  the  reasons  already  assigned ; 
and  sliould  be  one  that  would  not  vary  or  fail. 

To  effect  this,  the  ascending  column  of  air  must  be  rendered  specifically  lighter  than 
the  air  of  the  dericending  column,  which  circulates  through  the  workings;  and  this 
difference  of  specific  gravity  must  be  maintained  constantly  free  from  disturbance,  by 
accidental  causes,  and,  to  such  an  extent,  as  to  produce,  undei-  all  circumstances,  a  total 
amount  ol'  propelling  power  that  is  found  sufficient  for  the  complete  ventilation  of  the 
mine.  This  is  accomplished  by  conducting  the  whole  ofthe  gas  m  a  continuous  ascend- 
ing column,  free  from  interruption  or  disturbance,  up  the  separate  air-chimney ;  and  this 
ascending  power  is  further  increased  by  erecting  a  ventilating  chimney  (shown  by  dots, 
in  ihe  ve':tica!  section),  of  a  sufficient  height,  on  the  surface  of  the  ground,  into  the  base 
of  which  the  air-chimney  is  continued  so  as  to  form  one  uninterrupted  air  flue,  from  the 
top  of  the  ventilating  chimney,  down  to  the  air-head  in  the  seam  of  coal.  By  this 
means  a  long  experience  has  shown  that  a  constant  draught  is  established  and  secured, 
with  the  occasional  aids  of  a  small  furnace  or  steam  jet,  which  is  amply  sufficient,  in  all 
ordinary  cases,  to  defy  wind  and  weather,  and  also  to  produce  a  current  sufficiently 
strong,  that  it  mav  be  split,  and  such  portions  withdrawn  from  the  main  stream  of  air  as 
may  be  found  requisite  to  carry  on  the  preparatory  work  to  maintain  the  get  of  coal. 
The  air  in  the  gate  road  and  workings  is  warmed  above  the  temperatiire  of  the  air  on 
the  surface,  in  ordinary  mean  temperatures,  by  the  heat  of  the  earth,  and  is  consequently 
rarefied ;  this  is  aided  much  more  than  would  be  generally  supposed,  by  the  heat  pro- 
ceedinsr  from  the  numerous  workmen,  horses,  and  candles,  employed  in  the  mine;  and 
the  cuirent  is  further  increased  by  the  escape  of  the  gases,  which  are  specifically  lighter 
than  the  air,— the  air-head  forming,  with  the  air-chimney,  an  uninterrupted  and  con- 
tinuous pa-^sage  from  the  workings,  and  delivering  the  gas  into  the  ventilating  chimney: 
thus  a  draught  is  constantly  maintained  sufficient  for  all  usual  purposes.  The  weak 
power  of  draught  that  exists  in  the  old  sj'stem  is  materially  diminished  by  the  upcast 
shaft  being  of  a  larger  size  than  the  air-head  through  which  the  downward  current  of  air 
must  pass.  The  ascending  current,  in  consequence,  is  languid  and  slow  ;  whereas,  in 
the  author's  judgment,  it  should  have  considerable  velocity ;  and  much  more  important 
advantages  arise  from  this  cause  than  philosophers  account  for  or  will  admit 

Cases  may  occur  in  which  it  is  desirable,  for  temporary  purposes,  to  increase  the 
draught,  either  when  the  external  air  is  at  a  very  high  temperature,  or  from  other 
cauai ;  and  this  is  at  once  obtained  by  adding  a  furnace,  or  a  steam  jet,  of  any  required 
power,  to  the  ventilating  chimney.  By  means  of  a  fire  in  this  furnace,  any  degree  of  rare- 
faction may  be  produced  that  is  desired  in  the  ventilating  chimney;  and  it  is  recom- 
mended always  to  build  one  where  the  boiler  chimney  cannot  be  used,  that  it  may  be 
used  if  it  is  wanted.  In  such  cases,  the  flue  of  the  furnace  should  be  carried  up  per- 
pendicularly, for  30  or  40  feet,  against  the  side  of  the  ventilating  chimney,  before  it  is 


MINES,  VENTILATION  OP. 


227 


opened  into  it.  This  precaution  will  render  a  deflagration  of  the  gases,  passing  up  the 
chimney,  impossible,  when  the  furnace  is  used. 

The  principle  of  ventilating  pits  by  an  air-chimney  used  for  no  other  purpose  than  the 
passage  of  the  gas  and  the  current  of  air  from  the  workings  to  the  surface,  has  been 
adopted  by  the  author,  in  a  more  or  less  perfect  form,  for  more  than  30  years,  in  work- 
ing the  thick  and  thin  mines,  and  has  been  found  to  give  a  complete  and  absolute  com- 
mand over  the  ventilation  of  every  part  of  the  mines.  It  is  only,  however,  within  the 
last  few  years,  that  he  has  had  an  opportunity  of  carrying  it  through  many  extensive 
oits  systematically.  In  the  whole  of  the  author's  mines,  this  system  of  ventilation  is 
now  completely  carried  on.  The  thick  coal  is  sometimes  worked  in  one  pit,  and  in 
♦nother  pit^  brooch  coal,  heathen  coal,  or  the  white  iron  stone  lying  beneath  the  coal; 
and  sometimes  the  thick  coal  is  worked  in  both.  Very  little  preparation  is  necessary 
for  this  change  from  one  to  the  other,  as  the  air-chimney  reaches  to  the  lowest  vein ; 
and,  a  stopping  being  put  in  at  the  level  of  the  vein  intended  to  be  got,  a  supply  of  air 
may  be  immediately  procured  at  any  required  level.  The  thick  coal  abi>unde<l  in  gas 
in  these  pits ;  but  it  is  now  so  drained,  that  all  difficulties  have  disappeared.  The  use 
of  the  safety  lamp  has  become  a  form  rather  than  an  essential. 

A  great  improvement  is  perceptible  in  the  health  and  comfort  of  the  workmen  era- 
ployed.  The  air  in  these  pits  is  always  free  from  gas,  and  is  10°  Fahr.  cooler  than  the 
neighboring  pits,  worked  on  the  ordinary  system,  owing  to  the  regular  supply  of  fresh 
air.  They  have  been  frequently  tried,  and  found  to  be  62°  or  64°  in  the  workings ; 
whilst,  at  the  same  time,  the  air  in  the  working  of  pits  ventilated  in  the  ordinary  way 
was  found,  in  many  cases,  to  be  72°  to  74°  :  the  former,  the  temperature  of  a  comfortable 
sitting  room,  and  the  latter,  that  of  a  heated  cotton-mill. 

A  great  saving  of  expense  from  this  83'stem  will  be  found  also,  not  only  in  working 
the  thick  coal,  but^  subsequently,  in  getting  the  thinner  veins  of  coal  and  ironstone. 
A  considerable  amount  of  outlay,  as  well  as  frequentl}'  a  great  loss  of  time,  is  incurred 
in  obtaining  the  necessary  supplies  of  air  for  working  the  successive  strata  of  a  mine. 
Whereas,  the  air-chimney  is  accessible  at  any  point  in  the  shaft;  and  the  shaft  is 
4lways  kept  well  aired,  which  is  of  importance,  as  it  is  always  found  convenient  to  sus- 
pend the  workings  of  the  pit  for  a  considerable  time  after  the  partial  exhaustion  of  one 
of  the  strata,  and  before  it  may  be  desirable  to  commence  the  W(»rking  of  another. 

It  may  be  observed  here,  that  an  air-chimney  may  be  very  easily  cut  down  any  shaft 
that  has  been  sunk  in  the  usual  way.  The  author  has  cut  one  down  a  shaft  during  the 
night  whilst  the  pit  continued  to  draw  coal  during  the  day.  lie  executed  one  in  a 
pit  140  yards  deep,  in  about  a  month, — the  pit  continuing  to  draw  coal  during  the  day, 
whilst  tiie  air-chimney  was  made  during  the  night. 

Where  large  quantities  of  coal  are  to  be  draAvn,  a  number  of  shafts  are  necessary. 
Two  of  these  may  be  sunk  at  the  usual  distance  10  or  12  yards,  near  enough  to  be  com- 
manded l.y  the  same  winding  engine,  but  the  shafts  having  no  communicati«.n  with  each 
other.  But  if  the  form  of  the  mine  makes  it  more  convenient,  they  may  be  sunk 
singly  in  any  required  situation;  because  each  separate  shaft  will  provide  its  own  air, 
and  each  shaft  will  "get"  the  separate  section  of  mine  appropriated  to  it.  By  this 
means,  small  detached  portions  of  mine  have  been  got  to  advantage,  that  would  not 
have  paid  for  the  expense  of  two  shafts. 

By  this  arrangement,  a  smaller  quantity  of  air-heading  is  required  to  "  get "  the  same 
area  of  coal ;  and  the  process  of  complete  ventilation  can  be  more  easily  carried  out> 
as  w^ill  be  hereafter  noticed ;  and,  as  communications  between  different  shafts,  by  the 
gate-roads,  might  be  occasionally  convenient,  these  communications  may  be  under  the 
care  and  sole  control  of  the  mine  director,  who  may  keep  the  doors  locked,  if  advisable: 
the  ventilation  is  thus  not  materially  disturbed. 

In  the  different  plans  for  ventilating  mines,  the  merit  appears  to  have  been  awarded 
to  those  more  especially  who  have  succeeded  in  forcing  b}'^  any  means,  either  mechanical, 
or  by  the  use  of  powerful  furnaces,  the  largest  possible  quantity  of  air  through  the  work- 
ings in  a  given  time.  The  principle  explained  in  the  present  paper  is  totally  different, 
aud  diametrically  opposite  ;  for  it  consists  in  draining  the  gas  away  from  the  coal  before 
it  is  worked,  and  then  getting  the  coal  when  it  is  thus  drained,  and  carrying  no  more 
air  through  the  mines  than  is  required  for  light,  life,  and  health. 

Thus,  to  illustrate  the  difference  between  the  two  principles  of  ventilation,  supposing 
that  1,000  cubic  feet  of  gas  per  minute  is  emitted  by  the  coal,  and  passed  through  the 
workings,  36,000  cubic  feet  of  air  per  minute  mus^  according  to  the  old  method,  be 
passed  through  the  mine, —that  is  30,000  feet  to  dilute  the  gas,  and  5000  feet  to  supply 
the  workmen,  horses,  aud  candles,  in  the  workings;  but,  if  the  whole  of  this  1000  feet 
of  gas  can  be  carried  off  by  its  own  levity  and  intercepted  from  passing  into  the  workings, 
then  the  mine  will  be  better  and  more  safely  ventilated  by  5000  feet  of  air  j.er  minute 
than  by  25,000  feet  in  the  former  case ;  or,  if  the  whole  of  tlie  gas  cannot  be  intercepted, 
then  in  such  proportion  as  the  volume  of  gas  can  be  intercepted  and  carried  away.     And 


I    I 

I 


.Vni 


il   ■!' 


228 


MINES,  VENTILATION  OP. 


MINES.  VENTILATION  OF. 


229 


\  ii  I 


MM; 

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i 

1  '1  ii  ' 

Btipposing  the  opinion  of  the  author  to  be  correct,  that  the  gas  can  be  carried  away 
without  parsing  into  the  workings,  and  that  therefore,  a  very  greatly  reduced  quantity 
of  air  is  necessary  in  the  mine,  it  follows  that  (the  gas  being  of  the  same  specific  gravity 
as  atmospheric  air,  heated  up  to  612**)  when  the  gas  becomes  diffused  and  united  with 
the  air,  the  volume  of  air  and  gas  so  united,  is  of  less  specific  gravity  than  the  air,  and 
will  maintaiu  a  natural  ventilation  of  considerable  power.  It  may  be  observed  also, 
that  very  rapid  currents  of  air  through  the  passages  of  a  mine  are  always  attended 
with  great  inconvenience  to  the  workman,  and  may  be  attended  with  great  practical 
danger,  from  the  circumstance,  that  the  union  or  perfect  admixture  of  the  carbu- 
retted  hydrogen  with  atmospheric  air,  though  very  rapid,  is  not  instantaneous;  and 
when  in  a  mine  not  previously  drained  of  its  gas,  lai^e  quantities  of  the  gas  suddenly 
escaping  from  powerful  "  blowers,"  are  driven  forwards  by  a  current  of  air,  moving 
from  7  to  10  feet  per  second,  it  is  very  conceivable  that  they  are  not  diffused  at 
once,  but  carried,  in  some  degree,  like  a  cloud  of  steam,  forwards  through  the  mine, 
till  diffusion  has  brought  a  portion  to  the  "firing  point:"  this,  meeting  with  a  light, 
or  being  driven,  as  is  possible,  through  the  wire  of  the  safety  lamp,  will  inevitably 
cause  an  explosion. 

An  objection  that  was  made  to  the  adoption  of  the  system  was,  the  possibility  of  some 
disturbance  of  the  brickwork,  which  separated  the  air-chimney  from  the  main  shaft, 
either  by  a  violent  blow  from  the  ascending  skip  (which,  of  course,  could  not  be  the 
case  with  the  guides  that  are  now  generally  used),  or  by  any  accidental  explosion  that 
might  take  place  in  the  mine,  which,  it  was  contended,  might  force  it  outwards  into  the 
main  shaft.  A  mere  inspection  of  the  plan  must  convince  any  practical  person  that  such 
an  occurrence  is  impossible.  Any  force  from  without  would  be  resisted  by  the  convex 
surface  of  the  arch  which  encloses  the  small  shaft,  as  any  operating  from  within  would 
be  as  effectually  resisted  by  the  convex  surface  of  the  main  shaft.  Not  only  did  no  such 
occurrence  ever  take  place  in  the  numerous  pits  where  the  plan  has  been  used  without 
guides ;  but  even  where  the  air  chimney  was  cut  square,  possessing  so  much  less  resist- 
ing power,  it  remains  now  perfect  and  uninjured  after  a  lapse  of  more  than  thirty  years. 

Another  objection  was,  that  the  air-chimney  was  not  of  sufficient  dimensions  to 
ventilate  the  mine ;  and  this  objection  was  urged  and  re-urged  in  the  face  of  the  fact, 
that  the  author  had  expressly  stated  that  cases  might  occur,  where  even  a  seven  foot  air- 
shaft  might  be  required  and  employed  to  drain  very  fiery  mines.  The  parties  making 
this  objection  did  not  happen  to  recollect,  that,  in  fact,  this  air-chimney  was  precisely  of 
the  same  area  as  the  air-head,  which  they  themselves  always  employed,  to  form  the 
communication  between  the  workings  and  the  upcast  shaft.  That,  in  fact,  the  air- 
chimney  was  nothing  more  nor  less  than  a  continuation  of  the  air-head  from  the  work- 
ings to  the  surface  of  the  ground ;  and  consequently,  the  effect  of  enlarging  the  air-chim- 
ney would  be  to  diminish  the  velocity  of  the  ascending  column,  and  to  lose  the  increased 
temperature  the  air  had  acquired  in  passing  through  the  mine. 

Another  objection  was,  that  in  some  of  the  thinner  veins  no  upper  air-head  could  be 
driven  at  a  sufficient  height  to  allow  the  gas  to  escape  by  its  own  levity,  or  to  prevent  it 
from  getting  admission  to  the  workings.  There  may  be  exceptional  cases ;  as,  for 
example,  if  a  mine  can  be  supposed  to  lie  upon  a  perfectly  horizontal  plane  (but  the 
author  never  saw  an  instance  of  a  mine  to  any  considerable  extent  answering  this  de- 
scription ;  in  all  mines  he  has  ever  seen,  the  coal  forms  some  angle  to  the  horizon  in  some 
direction ;  and  a  very  small  angle  will  soon  obtain  a  height  of  6  or  7  feet,  which  is  quite 
sufficient  for  the  present  purpose):  in  that  case  the  air-head,  communicating  to  the  up- 
cast shaft,  may  be  made  always  to  descend  to  the  higher  part  of  the  plane,  which  will 
be  quite  sufficient  to  keep  the  mine  clear  from  gas,  by  allowing  it  to  pass  off  by  its  own 
levity.  But,  even  if  such  a  case  ever  should  occur,  a  remedy  may  often  be  obtained,  an 
instance  of  which  has  lately  occurred  to  the  author.  A  disturbance  in  the  thick  coal 
vein  was  found,  breaking  the  coal  through  and  throwing  it  into  a  trough  15  yards  below 
its  level :  of  course  if  the  air-head  had  continued  to  follow  the  vein,  it  must  have  been 
depressed  below  its  level  to  an  extent  equal  to  the  whole  thickness  of  the  coal,  which 
would  have  formed  a  barrier  against  the  passage  of  the  gas,  like  an  inverted  syphon, 
which  the  gas  would  not  have  passed.  The  remedy  adopted  by  the  author  was,  by 
commencing  an  air-head  from  the  air-chimney  in  another  measure,  the  "  flying  red,"  that 
lay  20  yards  above  the  main  coal,  and  continuing  it  till  it  had  passed  over  the  depressed 
point ;  a  communication  was  then  formed  to  the  upper  side  of  this  depressed  point,  which 
at  once  established  a  rising  air-head  for  the  whole  of  the  coal  on  the  further  side  of  the 
depression. 

It  may  be  perceived  that  the  plan  of  ventilation  here  recommended  is  combined,  in 
some  measure,  with  the  method  of  working  the  mines,  and  may  be  made  more  perfect 
and  efficient  by  the  adoption  of  a  sound  system.  The  common  mode  is  that  of  working 
the  mines  in  "  panes,"  or  "  panels,"  leaving  pillars  or  portions  of  coal  to  be  extracted 
at  a  future  period ;  but  this  is  considered  by  the  author  as  highly  objectionable. 

The  danger  of  this  method  must  be  sufficiently  obvious,  when  it  is  seen  that  the  air 


must  be  forced  through  the  most  crooked  and  winding  channels,  and  compelled  to  pass 
along  by  artificial  buildings,  or  "brattices,"  the  accidental  destruction  or  failure  of 
which  may  suspend  the  whole  ventilation. 

But  the  plan  exhibited  will  show  that  before  any  coal  is  got  from  the  mine,  in  the 
inethod  recommended  by  the  author,   the  roads  are  carried  out  to  the  extreme  extent 
that  the  coal  is  proposed  to  be  worked,  accompanied  by  their  air-heads :  by  this  means 
the   complete  drainage  of  the  gas  frowi  the  mass  of  coal  proposed  to  be  worked  is  ef- 
fected ;  and  these  roads  and  their  air-heads  are   originally  made  at  infinitely  less  ex- 
pense, and  are  alwaj's  in  a  safe  and  secure  state,  as  the  excavations  commence  at  the 
outside  of  the  coal  thus  intended  to  be  got ;  and  no  brattices  are  necessary,  as  double 
doors  may  be  used  in  any  of  these  roads  down  which  the  air  is  intended  to  circulate, 
either  to  regulate  the  quantity,  or  prevent  its  passage ;  and  the  current  of  air  may  be 
always  brought  to  act  directly  upon  the  working  face  of  the  coal. 

It  may  be  objected,  that  these  pillars  must  be  left  for  a  support,  owing  to  the  nature 
of  the  roof  of  the  mine ;  but  this  the  author  has  never  yet  seen,  and  is  disposed  to  think 
It  never  can  happen.  He  is  getting  veins  of  coal  of  30  feet  in  thickness  (in  two 
successive  workings  of  15  feet  each),  also  veins  of  6  feet,  4  feet  and  3  feet  thick-nessea. 
The  roofs  of  these  various  coals  differ  in  their  tenacity,  and  some  of  them  areextreme- 
Iv  tender,  and  yet  the  whole  of  the  coal  is  extracted  from  these  veins,  both  the  thick- 
est and  the  thiimest.  both  large  and  small  coal,  with  the  greatest  facility  and  safety. 

The  dangers  obviated  by^  this  mode  of  working  are  doubly  important ;  the  roof  gradu- 
ally descends  as  the  mine  is  excavated ;  all  dangers  are  left  bthind  ;  and  the  roof  is  con- 
solidated into  a  compact  mass  by  the  weight  of  the  superincumbent  otrata ;  consequently 
no  "  gouf  "  or  hollow  is  ever  formed,  and  no  lodgment  of  gas  can  take  place.  Secondly,  no 
large  or  small  coal  being  left  behind,  the  heating  of  the  gouf,  or  the  spontaneous  combus- 
tion to  which  all  mines  are  liable  where  small  coal  or  slack  is  left,  can  never  take  place. 

In  working  mines  in  panes  and  pillars  (where  a  part  of  the  coal  is  left  and  even- 
tually lost,  the  difficulty  of  obtaining  safe  ventilation  will  be  understw>d  from   the 
following  remarks.     At  Newcastle  on-Tyne,  the  brattices  have  been  all  blown  down 
by  an  explosion,  and  the  workings  filled  with  carbonic  acid  gas,  and  no  means  exist- 
ing of  quickly  restoring  the  ventilation  (as  at  the  Felling  CoUieryX  the  pits  and 
workings  could  not  be  entered,  nor  the  bodies  of  the  men   recovered,  for  week.«s  nay, 
even  months.     Every  man  in  the  mine,  though  out  of  the   reach  of  the  explosion, 
nece:*sarily  lost  his  life  by  the  after-damp.     A  very  recent  case  in  Scotland,  at  ^itshill, 
where  69  Jives  were  lost,  is  a  striking  example  ;  although  this  pit  had  a  good  and  dis- 
tinct upcast  shaft,  the  brattices  were  destroyed,  the  air  of  course  proceeded  along  the 
shortest  and  most  direct  road  from  the  downcast  to  the  upcast  shaft,  and  all  the  men 
who  had  been  supplied  with  air  by  the  diversion  of  the  currents,  depending  entirely 
upon  brattices  (\vhich  were  destroyed  by  the  explosion),  miserably  perished,  and  the 
whole  of  the  bodies  could  not  be  recovered  in  a  week's  time. 

Where  shafts  are  used  of  large  diameter,  divided  by  brattices,  and  of  such  large  di- 
mensions as  to  allow  one  side  of  the  brattice  to  form  the  downcast  and  the  other  the 
upcast  shaft,  a  similar  result  foUows  in  the  event  of  an  explosion,  to  that  last  mention- 
ed. A  part  of  the  brattice  (probably  at  a  considerable  depth)  is  ruptuied,  and  no 
current  of  air  can  be  procured  to  admit  of  its  repair,  except  by  means  which  involve 
loss  of  much  time  and  expense.  In  the  meantime  all  those  who  may  have  been  in  the 
pit,  at  the  time  (.f  the  explosion,  cannot  be  approached.  The  author  presumes  thatsome 
idea  of  economy  introduced  this  system  ;  but  he  is  satisfied  that  upon  this  point  an 
erroneous  impression  has  prevailed.'  The  expense  of  si  nking  these  single  divided  shafts 
(of  the  usual  diameter  of  15  or  16  feet),  is  so  very  great,  that  it  has  led  to  the  practice 
of  working  very  extensive  areas  of  coal  by  means  of  a  single  shaft ;  and  this  practice 
has  further  led  to  the  different  scientific  contrivances  for  impelling  the  air  over  these 
immense  areas,  by  which  the  ventilation  of  the  works  is  rendered  so  much  more  diffi- 
cult and  uncertain. 

Taking,  for  example,  a  pit  of  this  description,  of  15  feet  diameter,  by  which  is  worked 
an  art  a  of  2U()  acres  (and  instances*  might  be  adduced  where  four,  five,  and  six  times  that 
quantity  has  been  thus  worked),  it  is  evident  that  the  ventilation  of  a  coal  mine  of 
this  description,  where  the  air  passages  have  been  extended  to  the  length  of  70  luilea, 
must  be  attended  with  very  great  danger  and  vast  expense. 

^ow,  ihe  author  stjites  as  his  opinion,  ai;d  thinks  he  should  have  no  difficulty  in  pro- 
vmg  it  correct,  that  four  shafts  might  have  been  sunk  on  this  area  of  200  acres,  7  J  feet 
diameter  each,  in  proper  posit  ionsVith  their  air  chimneys,  for  comiderably  less  money 
than  the  one  shaft  cost;  and  if  this  can  be  established,  it  follows  that  the  200  acres  be- 
ing divded  into  sections  of  50  acres  each,  the  expense  of  the  underground  woik  would 
have  been  m.-st  materially  diminished,  and  that  the  ventilation  might  have  been  effect- 
ed with  much  greater  ease  and  security  in  separate  sections  of  60  acres  each,  and  the 
power  of  raising  coal  doubled,  as  there  would  be  always  two  ascending  and  two  de- 
scending curves,  instead  of  one. 


f — , 


230 


MINT. 


MINT. 


231 


1^^' 


!i  i 


t      i 


To  sum  up  the  conditions  and  principles  requisite  in  carrying  out  the  author's  plan 
eflFectually,  it  may  be  stated  : — 

Ist.  That  the  air-head  should  always  open  into  the  highest  practicable  part  of  the 
mines. 

2d.  Tlie  air-head  (or  what  may  be  properly  called  the  gas-head),  by  which  is  meant, 
the  horizontal  air  or  gas-passage,  shall  always  be  in  continuous  communication  from 
the  workings  to  a  vertical  air  chimney,  or  separate  shaft,  of  3,  4,  5  or  more  feet  diume 
ter,  whichever  shall  be  required ;  but  always  of  sufficient  dimensions  to  carry  off  the 
gas  and  air  from  the  workings. 

3d.  That  the  air-head,  or  gas-head,  shall  not,  in  any  part  of  its  course,  be  depressed 
below  the  level  of  its  opening  into  the  workings. 

4th.  That  the  air-chimney  (of  such  dimensions  as  the  mine  requires),  by  which  is 
meant  the  vertical  air  or  gas  i)as.Hage,  shall  never  be  used  for  any  other  purpose  than 
the  passage  of  the  current  of  the  g"as  and  air  from  the  workings  to  the  surface;  and 
that  it  shall  be  closed  from  the  external  air,  till  it  arrives  at  its  point  of  exit. 

6tli.  That  the  vertical  air-chimney  should  be  closed  at  the  top,  and  separated  from 
the  shaft,  and  should  then  be  connected  to  the  ventilated  chimney,  or  the  chimney 
connected  by  a  horizontal  flue  with  the  boiler,  so  that  the  current  of  air  may  not  at 
any  time  be  disturbed  or  interru|)ted.  i  •  i    i 

6th.  That  the  gate  roads  should  always  be  driven  to  the  extreme  point  to  which  th« 
workings  of  the  coal  are  intended  to  be  extended  ; — that  the  coal  may  previously  be 
drained  of  its  gas  bt-foie  any  coal  is  got  out;  by  which  means  the  gate  or  horse-roads, 
and  the  air  or  gas-head,  may  be  made,  and  afterwanis  be  maintained,  at  considerable 
less  expense,  in  a  safe  and  secure  state,  and  the  gases  be  gradually  drained  otf,  before 
it  is  neeessiiry  to  get  the  coal. 

The  author  in  conclusion  states,   that  the  case  may  be   considered  as  exeptional, 
rather  than  general,  in  which  any  insurmountable  difticulty,  in  providing  the  remedy 
for  accidental  derangements  of  the  coal  strata  will  present  itself;  and  render  it  neces- 
sary to  interfere  materially  with  the  principles  recommended  for  adoption. 

MINIUM.  (En?,  and  Fr. ;  Red  lead;  Mennige,  Germ.)  This  pigment  is  a  peculiar 
oxyde  of  lead,  consisting  of  two  atoms  of  the  protoxyde  and  one  of  the  peroxyde  ;  but,  as 
found  in  commerce,  it  always  contains  a  little  extra  protoxyde,  or  yellow  massicot.  It 
is  prepared  by  calcining  lead  upon  a  reverberatory  hearth  with  a  slow  fire,  and  frequent 
renewal  of  the  surface  with  a  rake,  till  it  becomes  an  oxyde,  taking  care  not  to  fuse  it. 
The  calcined  mass  is  triturated  into  a  fine  powder  in  a  paint  mill,  where  it  is  elutriated 
with  a  stream  of  water,  to  carry  off  the  finely  levigated  particles,  and  to  deposite  them 
aAersvards  in  tanks.  The  powder  thus  obtained,  being  dried,  is  called  massicot.  It  is 
converted  into  minium,  by  being  put  in  quantities  of  about  50  iwunds  into  iron  trays, 
1  foot  square,  and  4  or  5  inches  deep.  These  are  piled  up  upon  the  reverberatory  hearth, 
and  exposed  durins?  the  nisrht,  for  economy  of  fuel,  to  the  residuary-  heat  of  the  furnace, 
whereby  the  massicot  absorbs  more  oxygen,  and  becomes  partially  red  lead.  This,  after 
being  stirred  about,  and  subjected  to  a  similar  low  calcining  heat  once  and  again,  will  be 
found  to  form  a  marketable  red  lead. 

The  best  minium,  however,  called  orange  min£,  is  made  by  the  slow  calcination  of 
good  white  lead  (carbonate)  in  iron  trays.  If  the  lead  contains  either  iron  or  copper, 
it  affords  a  minium  which  cannot  be  employed  with  advantage  in  the  manufacture  of 
flint-irlass,  for  pottery  glazes,  or  for  house-painting. 

Dumas  found  several  samples  of  red  lead  which  he  examined  to  consist  of  the 
chemical  sesquioxyde  and  the  protoxyde,  in  proportions  varjing  from  50  of  the  former 
and  50  of  the  latter,  to  95  3  of  the  former  and  4-7  of  the  latter.  The  more  oxygen 
gas  it  gives  out  when  heated,  the  better  it  is,  generally  speaking.  See  Naples 
Yellow. 

MINT.  (Monnaiej  Fr. ;  Munze,  Germ.)  The  chief  use  of  gold  and  silver  is  to 
serve  for  the  medium  of  exchange  in  the  sale  and  purchase  of  commodities,  a  function 
for  which  they  are  pre-eminently  fitted  by  their  scarcity,  by  being  unalterable  by  com- 
mon agents,  and  condensing  a  great  value  in  a  small  volume.  It  would  be  very  incon- 
venient in  general  to  barter  objects  of  consumption  against  each  other,  because  their 
carriage  would  be  expensive,  and  their  qualities,  in  many  cases,  easily  injured  by 
external  agents,  &c.  Gold  is  exempt  from  siwntaneous  change,  and  little  costly  in 
conveyance.  Mankind  at  a  verj'  early  period  recognised  how  much  easier  it  was  to 
exchange  a  certain  weight  of  gold  or  silver  for  objects  of  commerce,  than  to  barter  these 
objects  themselves  ;  and  thenceforth  all  agreed  to  pay  for  their  purchases  in  bars  or  ingots 
of  these  precious  metals.  But  as  their  intrinsic  value  depends  upon  their  purity,  it  be- 
came necessary  to  stamp  on  these  bars  their  standard  quality  and  their  weight. 

The  inconvenience  of  using  ingots  in  general  trade,  on  account  of  the  difficulty  of 
defining  fractional  values,  has  determined  governments  to  coin  pieces  of  money,  thai 
is,  quantities  of  metal  whose  weight  and  standard  were  made  known  and  guarantied  by 
the  effigies  of  the  prince.    It  is  true,  indeed,  that  kings  have  become  frequently  coinera 


of  base  money,  by  altering  the  weight  and  purity  of  the  pieces  apparently  guarantied 
by  their  impress.  By  such  reductions,  modern  coins  represent  less  of  the  precious  metal 
than  they  did  long  ago.  The  ordomuince  of  755,  for  the  coining  of  sous  in  France,  proves 
that  there  was  then  as  much  fine  silver  in  a  single  sous  as  there  is  now  in  a  piece  of  5 
francs.  During  the  last  two  centuries,  indeed,  silver  coins  have  been  diminished  two 
thirds  in  weight. 

But  since  knowledge  has  become  more  generally  diffused,  it  has  been  shown  that  these 
frauds  are  equally  injurious  to  the  prince  and  to  public  faith.  A  sovereign  may,  it  is 
true,  declare  by  a  decree  that  a  shilling-piece  is  to  be  held  worth  five  ;  but  let  us  consider 
the  consequences  of  this  decree.  All  the  individuals  who  have  rents  or  capital  sums  to 
receive  will  be  ruined,  by  getting  in  metallic  value  only  one  fifth  of  what  is  due  to  them: 
for  although  the  nominal  value  should  be  the  same  as  what  they  are  entitled  to,  lae 
intrinsic  value  would  be  but  a  fifth  of  the  former;  so  that  when  they  go  to  purchase  the 
necessaries  or  comforts  of  life,  the  dealer  who  sells  them  will  at  once  raise  their  price 
five-fold.  Each  article  of  merchandise  would  thus  acquire  a  nominal  price  5  times 
greater ;  and  he  who  had  received  payment  of  a  debt  in  that  money  could  not  with  it 
procure  more  than  one  fifth  of  the  goods  he  could  have  previously  commanded.  That 
fraudulent  law  would,  therefore,  favor  the  debtors  at  the  expense  of  the  creditors ;  and 
as  the  state  is  commonly  a  great  debtor,  especially  when  it  has  recourse  to  the  deprecia- 
tion of  the  currency,  it  is  obvious,  that  however  illicit  the  gain  which  it  makes,  it  still 
does  gain ;  and  this  is  the  reason  why  princes  have  so  often  tampered  with  the  mint. 
But  let  us  examine  the  other  consequences  of  this  decree. 

If  the  sovereign  is  a  debtor,  he  is  also  a  creditor  and  consumer,  and  even  the  most 
considerable  of  any.  The  taxes  which  he  imposes  are  paid  him  in  this  deteriorated 
money,  returned  to  him  at  its  nominal  value ;  and  the  purveyors  of  his  armies,  h's 
buildings,  and  his  household,  sell  him  their  commodities  only  at  the  actual  market 
price.  We  may  infer  from  this  simple  development  that  the  coin  with  which  he  pays 
for  any  object  has  the  same  intrinsic  value  as  the  object ;  and  that  the  name  given  to 
the  coin  is  of  no  consequence.  The  prince  may  call  it  a  crown,  a  ducat,  or  a  rix-dollai 
at  his  pleasure ;  and  he  may  assign  any  value  to  it  that  his  caprice  may  suggest,  yet  this 
will  not  affect  its  value ;  for  this  is  fixed  beyond  his  control  by  the  general  nature  of 
things.  The  prince  may,  indeed,  at  the  outset,  have  profited  by  defrauding  his  creditors, 
and  by  authorizing  each  debtor  to  imitate  him,  but  he  will  soon  lose  whatever  he  may 
have  gained ;  and  he  will  thus  learn  to  his  cost  that  it  was  bad  policy  to  sacrifice  his 
character  by  giving  an  example  of  a  fraud  so  truly  unprofitable  in  the  issue.  More- 
over, he  will  lose  still  as  much  in  the  following  years,  because  his  treasury  will  receive 
only  one  fifth  part  of  the  taxes,  unless  he  has  quintupled  the  imposts.  It  may  be  said, 
indeed,  that  he  might  do  the  one  thing  along  with  the  other.  But  every  one  knows  that 
this  power  is  neither  generally  permitted  to  princes,  nor,  if  it  were,  could  it  be  safely 
exercised.  Serious  political  crises  would  combine  to  endanger  the  stability  of  the  govern- 
ment ;  which  besides,  as  the  main  consumer  in  the  nation,  must  lose  always  as  much  as 
it  seems  to  gain. 

It  is  therefore  manifest,  that  the  alteration  of  the  standard  and  weight  of  the  coinage 
is  at  once  a  crime  and  a  ruinous  action  for  the  sovereign  power  to  commit;  and  hence 
such  disastrous  measures  have  been  long  abandoned  in  all  well-regulated  states.  A  gold 
sovereign  is  intrinsically  worth  20  shillings,  minus  the  cost  of  coinage ;  for  were  it  worth 
more,  all  our  sovereign  pieces  would  be  exported  or  melted  down,  to  obtain  the  difference 
of  value,  however  trifling  it  might  be ;  and  were  it  worth  less,  it  would  be  the  source  of 
loss  similar  to  what  the  state  occasions  when  it  depreciates  the  coin. 

To  comprehend  the  true  value  of  a  coin,  we  must  regard  this  piece  as  an  article  of 
merchandise,  whose  value  depends,  as  that  of  every  thing  else,  on  its  usefulness,  the 
esteem  in  which  it  is  held,  and  the  demand  for  it  in  the  market.  Grain  increases  in 
value  when  there  are  few  sellers  and  many  buyers ;  gold  and  silver  are  in  the  same  pre- 
dicament. The  value  of  these  metals  is  much  augmented,  indeed,  by  the  universal  cur- 
rency they  obtain  when  struck  into  money ;  a  value  additional  to  what  they  possess  as 
object  5  of  the  arts.  This  value  of  the  precious  metals  changes  with  time  and  place,  like 
that  of  every  merchandise ;  their  abundance,  since  the  discovery  of  America,  has  greatlj 
lowered  their  value ;  that  is,  with  the  same  weight  of  metal,  we  cannot  at  the  present 
day  purchase  the  same  quantity  of  corn,  land,  wool,  &c.  as  formerly.  In  the  countries 
where  silver  abounds,  this  metal  has  less  value,  or,  in  other  terms,  commodities  are 
dearer.  Hence  the  metal  tends  to  resume  its  equilibrium  in  flowing  into  those  places 
where  it  is  rarer ;  which  means,  that  the  consumer  prefers  purchasing  his  commodities 
there,  rather  than  In  another  place,  if  he  can  easily  transport  them  to  where  they  arc 
dearer. 

^  It  was  formerly  believed  that  a  country  is  rich  when  it  has  a  great  deal  of  gold  and 
silver ;  but  this  popular  illusion  has  passed  away.  Spain  has  never  been  poorer  than 
«ince  the  discovery  of  America,  because  its  national  industry  has  been  ruined,  and  the 


I 


f    •■.^_..=^ 


232 


MINT. 


capitals  merely  passed  through  its  hands  to  spread  over  the  rest  of  Europe,  from  which 
it  was  obU'»ed  to  import  every  thing  that  its  want  of  home  manufactures  made  it  neces- 
sary  to  procure  from  abroad.  We  may  add  to  these  the  prodigalities  of  the  court,  which, 
supposing  its  wealth  inexhaustible,  tried  to  corrupt  aU  the  ministers  of  the  other  powers, 
in  furtherance  of  the  chimera  of  universal  dominion.  The  richest  state  is  that  in  which 
there  is  most  industry,  whereby  the  inhabitants  may  procure  every  thing  indispensable  to 
the  conveniences  and  comfort!  of  life.  Gold  as  a  useful  metal,  and  a  medium  of  exchange, 
is  undoubtedly  very  precious,  and  an  adequate  quantity  for  these  exchanges  must  be  had; 
but  as  it  is  ffood  for  very  little  besides,  nay,  as  an  excess  is  even  hurtful,  it  soon  begins 
to  fly  of  itself  towards  the  places  where  it  is  more  needed  or  less  common. 

With  regard  to  the  relative  value  of  gold  and  silver,  several  details  have  already  been 
given  in  our  view  of  the  mineral  wealth  of  the  globe.  Three  centuries  ago,  an  ounce 
of  gold  was  worth  at  London  or  Paris  10  ounces  of  silver ;   now  it  may  be  exchanged  for 

15  ounces  and  a  half.  ^  ^  .        .  , .       j    .     j  _j  x: 

The  par  of  two  coins  results  from  the  comparison  of  their  weight  and  standard  line- 
ness.  Let  us  take  for  an  example  the  conversion  of  English  gold  sovereigns  worth  20 
shillings  or  a  pound  sterling,  in  relation  to  the  French  louis  of  20  francs.  The  standard 
of  the  sovereign  gold  is  0-917,  fine  gold  being  1000;  its  weight  is  125,256  gr.  English, 
or  7-980855  grammes;  by  multiplying  this  weight  into  its  standard,  we  have  a  product 
of  7-3 18444035;  this  is,  in  grammes,  the  quantity  of  pure  gold  contained  in  the  sovereign 
piece.  The  piece  of  20  francs  has  a  legal  standard  of  09 ;  and  multiplyinff  this  number 
by  the  weight  of  the  louis,  6-45161  grammes,  we  find  that  it  contains  5-806449  of  pure 
metal.     We  then  make  this  proportion :—  «   ,     «     ,.  »^ 

As  5-806449  :  20  francs  : :  7-31844  :  25-2079  francs;  or  the  value  of  the  English  sove- 
reign is  nearly  25-21  francs,  in  French  gold  coin.  A  similar  calculation  may  be  made  for 
silver  coins.  The  French  rule  for  finding  the  par  of  a  foreign  gold  coin,  or  its  intrinsic 
value  in  francs,  is  to  multiply  its  weight  by  its  standard  or  titre,  and  that  product  by  3*. 
The  par  of  foreign  silver  money,  or  its  intrinsic  value  in  francs,  is  obtained  by  multiplying 
its  weiffht  in  grammes  by  its  standard  in  thousand  parts,  and  by  |.  The  French  5-franc 
piece  has  its  standard  or  titre  at  0-9,  and  weighs  25  grammes. 

The  assavina  of  gold  for  coin  and  trinkets  requires  very  delicate  management.  The 
French  take  half  a  gramme  at  most  (about  7$  grains)  of  gold,  and  fuse  it  with  thrice  its 
weight  of  silver,  as  already  described  under  Assay.  The  parting  is  the  next  operation. 
For'this  purpose  the  button  of  gold  and  silver  alloy  is  first  hammered  flat  on  a  piece  of 
steel,  and  then  made  feebly  red  hot  in  burning  charcoal  or  over  a  lamp  flame.  After 
being  thus  annealed,  the  metal  is  passed  through  the  rolling  press,  till  it  be  con- 
verted into  a  plate  about  JL  of  an  inch  thick.  After  annealing  this  riband,  it  is  coiled 
into  a  spiral  form,  introduced  immediately  into  a  small  matrass  of  a  pear  shape,  an  assay 
matrass,  and  about  500  grains  of  nitric  acid,  sp.  grav.  M85,  are  poured  over  it.  Heat 
being  now  applied  to  the  vessel,  the  solution  of  the  silver  and  copper  alloys  ensues,  and 
after  22  minutes  of  constant  ebullition,  the  liquid  is  poured  off  and  replaced  by  an  equal 
quantity  of  nitric  acid,  likewise  very  pure,  but  of  the  density  1-28.  This  is  made  to  boil 
for  about  10  minutes,  and  is  then  poure<l  ofl",  when  the  matrass  is  filled  up  with  distilled 
water  to  the  brim.  In  conclusion,  a  small  annealinff  crucible  is  inverted  as  a  cup  over 
the  mouth  of  the  matrass,  which  is  now  turned  upside  down  with  a  steady  hand ;  the 
slip  of  metal  falls  into  the  crucible  through  the  water ;  which  by  sustaining  a  part  of  ito 
weight  softens  its  descent  and  prevents  its  tearin?.  The  matrass  is  then  dexterously 
removed,  without  lettin?  its  water  overflow  the  crucible.  The  water  is  gently  decanted 
from  the  crucible,  which  is  next  covered,  placed  in  the  middle  of  burning  charcoal,  and 
withdrawn  whenever  it  becomes  red  hot.  After  cooling,  the  metal  slip  is  weighed  very 
exactly,  whence  the  weight  of  fine  gold  in  the  alloy  is  known.  Stronger  acid  than  that 
prescribed  above  would  be  apt  to  tear  the  metallic  riband  to  pieces,  and  it  would  be  diffi- 
cult to  gather  the  fine  particles  of  gold  together  again.  The  metallic  plate  becomes  at 
last  merely  a  golden  sieve,  with  very  little  cohesion.  When  copper  is  to  be  separated 
from  gold  by  cupellation,  a  higher  temperature  is  requisite  than  in  cupelling  silver  coin. 

The  coining  apparatus  of  the  Royal  Mint  of  London  is  justly  esteemed  a  masterpiece 
of  mechanical  skill  and  workmanship.  It  was  erected  in  181 1,  under  the  direction  of  the 
inventor,  Mr.  Boulton ;  and  has  since  been  kept  in  almost  constant  employment. 

The  melting  pots  (fig.  973)  are  made  of  cast-iron,  and  hold  conveniently  400  pounds 
of  metal.  They  are  furnished  with  a  spout  or  lip  for  pouring  out  the  metal,  and  with 
two  ears,  on  which  the  tongs  of  the  crane  lay  hold  in  lifting  them  out  of  the  furnace. 
The  pot  rests  on  pedestals  on  the  grate  of  the  furnace,  and  has  a  ring  cast  on  its  edge 
to  prevent  the  fuel  falling  into  it.  Whenever  it  becomes  red  hot,  the  metal  properly  pre- 
pared and  mixed,  so  as  to  produce  an  alloy  containing  0-915  parts  of  cold,  is  put  in,  and 
during  the  melting,  which  occupies  some  hours,  it  is  occasionally  stirred.  The  moulds 
are  meanwhile  prepared  by  warming  them  in  a  stove,  and  thereafter  bv  rubbing  their 


BIINT. 

inside  surfaces  with  a  cloth  dipped  in  oil,  by  which  means  the  ingots  cast  in  them  ?et 
a  better  surface.    Fig,  974  represents  a  side  view  of  the  carriage,  charged  with  its 


•MMiIds.     When  the  proper  number  of  moulds  is  introduced,  the  screws  at  the  end,  r^ 
presented  at  1 1,  are  screwed  fast,  to  fix  them  all  tight. 
The  pot  of  fused  metal  is  lifted  out  of  the  furnace  6;  the  crane  (y!;.  975,)  then 


swung  round,  and  lowered  down  into  the  cradle  /,  m,  n,  o  of  the  pouring  machine, 
•ntil  the  ring  on  the  edge  of  it  rests  on  the  iron  hoop  n,  which,  being  screwed  tight  up, 
holds  it  secure,  and  the  crane-tongs  are  removed.  One  of  the  assistants  now  takes  the 
winch  handle  «  in  one  hand,  and  y  in  the  other.  By  turning  y  he  moves  the  car- 
riage forward,  so  as  to  bring  the  first  mould  beneath  the  lip  of  the  melting  pot ;  and  by 
turning  s,  he  inclines  the  pot,  and  pours  the  metal  into  the  mould.  He  then  fills  the 
other  moulds  in  succession.  The  first  portion  of  liquid  metal  is  received  in  a  small  iron 
ipoon,  and  is  reserved  for  the  assay-master ;  a  second  sample  is  taken  from  the  centre 
«f  the  pot,  and  a  third  from  the  bottom  part.     Each  of  these  is  examined  as  to  its  quality. 

The  ingots,  which  are  about  10  inches  long,  7  broad,  and  6  tenths  of  an  inch  thick,  are 
now  carried  to  the  rolling  mill. 

Fig.  976,  where  a  represents  a  large  spur  wheel,  fixed  on  the  extremity  of  a  long 


!■; 


234 


MINT. 


MINT. 


235 


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U 


i 


horizontal  shafl  b  b,  extending  beneath  the  whole  mill.  This  wheel  and  shitft  arc  driren 
by  a  smaller  wheel,  fixed  on  the  main  or  fly-wheel  shaft  of  a  steam  engine  of  36-horse 
power.  The  main  shaft  b  of  the  rolling  mill  has  wheels  c,  d,  k  fixed  upon  it,  to  give 
motion  to  the  respective  rollers,  which  are  mounted  at  f  and  g,  in  strong  iron  frames, 
bolted  to  the  iron  sills  a  a,  which  extend  through  the  whole  length  of  the  mill,  and  rest 
upon  the  masonry,  in  which  the  wheels  are  concealed.  The  two  large  wheels  c  and  k 
give  motion  to  the  wheels  h,  i,  which  are  supi>orte(l  on  bearings  between  two  standards 
6,  b,  bolted  down  to  the  ground  sills.  On  the  ends  of  the  axes  of  these  wheels  are  heads 
^for  the  reception  of  coupling  boxes  d,  d,  which  unite  them  to  short  connecting  shafts 
K  l;  and  these  again,  by  means  of  coupling  boxes,  convey  motion  to  the  upper  rollers 
e,  e,  of  each  pair,  at  f  and  g.  The  middle  wheel  d  upon  the  main  shaft  b  gives  motion 
to  the  lower  rollers  in  a  similar  manner.  Thus  both  the  rollei-s  «,/  of  each  frame  receive 
their  motion  from  the  main  shaft  with  equal  velocity,  by  means  of  wheels  of  large  radius, 
which  act  with  much  more  certainty  than  the  small  pinions  usually  employed  in  rolling 
mills  to  connect  the  upper  and  lower  rollers,  and  cause  them  to  move  together. 

The  rolling  mill  contains  four  pairs  of  rollers,  each  driven  by  its  train  of  wheel  work  ; 
the  mill,  therefore,  consists  of  two  such  sets  of  wheels  and  rollers  as  are  represented  in 
our  figure.  The  two  shafts  are  situated  parallel  to  each  other,  and  receive  their  motion 
from  'the  same  steam  engine.  This  admirable  rolling  mill  was  erected  by  John 
Rennie,  Esq. 

The  ingots  are  heated  to  redness  in  a  furnace  before  they  are  rolled.  The  iwo  fur- 
naces for  this  purpose  are  situated  before  two  pairs  of  rollers,  which,  from  being  used  to 
consolidate  the  metal  by  rolling  whilst  hot,  are  termed  breaking-down  rollers.  Two 
men  are  employed  in  this  operation ;  one  taking  the  metal  from  llie  furnace  with  a  pair 
of  tongs,  introduces  it  between  the  rollers ;  and  the  other,  catching  it  as  it  comes 
through,  lifts  it  over  the  top  roller,  and  returns  it  to  his  fellow,  who  puts  it  through 

again,   having   previously   approximated   the 
rollers    a   little   by    their  adjusting   screws. 
After  having  been  rolled  in  this  manner  four 
or  five  times,  they    are  reduced  to  nearly 
two  tenths  of  an  inch   thick,  and  increased 
lengthwise  to  about  four  times  the  breadth  of 
the  insot.      These  plates,  while  still  warm, 
are  rubbed  over  with  a  dilnte  acid  or  pickle, 
to  remove  the    color   produced  by    the  heat, 
and  are  then  cut  up  into  narrow  slips  across 
the  breadth  of  the  plate,  by  means  of  the  cir- 
cular shears ^g.  9*77. 
This  machine  is  worked  by  a  spur-wheel  at  the  extremity  of  the  main  shaft  b  of  the 
rolling  mill  (^g.  916.)     It  consists  of  a  framing  of  iron  a  a,  supporting  two  shafts  b  b. 
Which  are  parallel  to  each  other,  and  move  together  by  means  of  two  equal  spur-wheels 
c  c  the  lower  one  of  which  works  with  the  teeth  of  the  great  wheel  above  mentioned, 
upon  the  main  shaft  of  the  rolling  mill.     At  the  extremities  of  the  two  shafts,  wheels 
or  circular  cutters  are  fixed  with  their  edges  overlapping  each  other  a  little  way. 
F  represents  a  shelf  on  which  the  plate  is  laid,  and  advanced  forward  to  present  it  to  the 
cutter ;  and  g  is  a  ledge  or  guide,  screwed  down  on  it,  to  conduct  the  metal  and  to  regu- 
late the  breadth  of  the  piece  to  be  cut  off.     Hence  the  screws  which  fasten  down  the 
ledffe  are  fitted  in  oblong  holes,  which  admit  of  adjustment.     The  workman  holds  the 
plate  flat  upon  the  surface  f,  and  pushing  it  towards  the  shears,  they  will  lay  hold  of  it, 
and  draw  it  through  until  they  have  cut  the  whole  length.     The  divided  parts  are  also 
prevented  from  curling  up  into  scrolls,  as  they  do  when  cut  by  a  common  pair  of  shears  ; 
because  small  shoulders  on  e  and  r,  behind  the  cutting  edge,  keep  them  straight.     Be- 
hind the  standard,  supporting  the  back  pivots  of  the  shafts  b  b  of  the  cutter,  is  a  frame  /, 
with  a  screw  m  tapped  through  it.    This  is  used  to  draw  the  axis  of  the  upper  cutter  d 
endwise,  and  keep  its  edge  in  close  contact  with  the  edge  of  the  other  cutter  e.     The 
slips  or  ribands  of  plate  are  now  carried  to  the  other  two  pairs  of  rollers  in  the  rolling 
mill  which  are  made  of  case-hardened  iron,  and  better  polished  than  the  breaking-down 
rollers.     The  plates  are  passed  cold  between  these,  to  bring  them  to  exactly  the  same 
thickness;  whence  they  are  called  adjusting  or  planishing  rollers.     The  workman  here 
tries  every  piece  by  a  common  gauge,  as  it  comes  through.     This  is  a  piece  of  steel 
having  a  notch  in  it ;  the  inside  lines  of  which  are  ver)'  straight,  and  inclined  to  one 
another  at  a  very  acute  angle.     They  are  divided  by  fine  lines,  so  that  the  edge  of  the 
plate  being  pressed  into  the  notch,  will  have  its  thickness  truly  determined  by  the  depth 
to  which  it  enters,  the  divisions  showing  the  thickness  in  fractions  of  an  inch. 

in  roiling  the  plate  the  second  time,  all  the  plates  are  successively  passed  through  the 
rollers;  then  the  rollers  being  adjusted,  they  are  passed  through  another  time.  This 
is  repeated  thrice  or  even  four  times ;  after  which  they  are  all  tried  by  the  gauge,  and 


thus  sorted  into  as  many  parcels  as  there  are  diflTerent  thicknesses.  It  is  a  curious  cir- 
cumstance, that  though  the  rollers  are  no  less  than  14  inches  in  diameter,  and  their  frame 
{>roportioually  strong,  they  will  yield  in  some  degree,  so  as  to  reduce  a  thick  plate  in  a 
ess  degree  than  a  thin  one ;  thus  the  plates  which  have  all  passed  through  the  same 
rollers,  may  be  of  3  or  4  different  degrees  of  thickness,  which  being  sorted  by  the  gauge 
into  as  many  parcels,  are  next  reduced  to  the  exact  dimension,  by  adapting  the  rollers  to 
each  parcel.  The  first  of  the  parcel  which  now  comes  through  is  tried,  by  cutting  out  a 
circular  piece  with  a  small  hand  machine,  and  weighing  it.  If  it  proves  either  too  light 
or  too  heavy,  the  rollers  are  adjusted  accordingly,  till  by  a  few  such  trials  they  are  found 
to  be  correct,  when  all  the  parcel  is  rolled  through.  The  trial  plates  which  turn  out  to 
be  too  thin,  are  returned  as  waste  to  the  melting-house.  By  these  numerous  precautions, 
the  blanks  or  circular  discs,  when  cut  out  by  the  next  machine,  will  be  very  nearly  of  the 
same  weight ;  which  they  would  scarcely  be,  even  if  the  gauge  determined  all  the  plates 
to  the  same  thickness,  because  some  being  more  condensed  than  others,  they  would  weigh 
differently  under  the  same  volume. 

A  great  improvement  has  been  made  on  that  mode  of  lamination,  by  the  late  Mr. 
Barton's  machine  for  equalizing  the  thickness  of  slips  of  metal  for  making  coin,  which 
has  been  for  several  years  introduced  into  the  British  mint.  A  side  elevation  is  shown 
in^g.  978,  and  a  plan  in^g.  979.  It  opeiates  in  the  same  way  as  wire-drawing  mechan- 
isms ;  namely,  pulls  the  slips  of  metal  forcibly  through  an  oblong  opening,  left  between 
two  surfaces  of  hardened  steel.  The  box  or  case  which  contains  the  steel  dies,  composed 
of  two  hardened  cylinders,  is  represented  at  c  in  Jig.  978.  The  pincers  employed  to  hold 
the  metal,  and  draw  it  through,  are  shown  at  s  r. 


The  slips  of  metal  to  be  operated  on  by  the  drawing  machine,  are  first  rendered 
thinner  at  one  end,  that  they  may  be  introduced  between  the  dies,  and  also  between  the 
jaws  of  the  pincers.  This  thinning  of  the  ends  is  effected  by  another  machine,  con- 
sisting of  a  small  pair  of  rollers,  mounted  in  an  iron  frame,  similar  to  a  rolling-milL 
The  upper  roller  is  cylindrical,  but  the  lower  is  formed  with  3  flat  sides,  leaving  merely 
portions  of  the  cylinder  entire,  between  these  flat  sides.  The  distance  between  the 
centres  of  the  rollers  is  regulated  by  screws,  furnished  with  wheels  on  their  upper  ends, 
similar  to  what  is  seen  in  the  drawing  dies  at  c.  The  two  rollers  have  pinions  on  their 
axes,  which  make  them  revolve  together ;  they  are  set  in  motion  by  an  endless  strap 
passing  round  a  drum,  upon  whose  axis  is  a  pinion  working  into  the  teeth  of  a  whed 
fixed  upon  the  axis  of  the  lower  roller. 

The  end  of  a  slip  of  metal  is  presented  between  the  rollers  while  they  are  in  motion, 
not  on  that  side  of  the  roller  which  would  operate  to  draw  in  the  slip  between  them,  as 
in  the  rolling-press  above  described,  but  on  the  contrary  side,  so  that  when  one  of  the 
flat  sides  of  the  under  roller  fronts  horizontally  the  circumference  of  the  upper  roller,  an 
opening  is  formed,  through  which  the  slip  of  metal  is  to  be  inserted  until  it  bears  against 
a  fixed  stop  at  the  back  of  the  rollers.  As  the  rollers  continue  to  turn  round,  the 
cylindrical  portions  come  opposite  to  each  other,  and  press  the  metal  between  them, 
forcing  it  outwards,  and  rendering  the  part  which  has  been  introduced  between  the 
rollers  as  thin  as  the  space  between  their  cylindrical  surfaces.  Thus  the  end  of  the  slip 
of  metal  becomes  attenuated  enough  to  pass  between  the  dies  of  the  drawing  machine, 
and  to  be  seized  by  the  pincers. 

In  using  the  drawing  machine,  a  boy  takes  hold  of  the  handle  «  of  the  pincers,  fheir 
hook  of  connexion  with  the  endless  chain  /,  /,  not  shown  in  the  present  figure,  being  dis- 
engaged, and  he  moves  them  upon  their  wheels  towards  the  die-box  c.  In  this  move- 
■lent  the  jaws  of  the  pincers  get  opened,  and  they  are  pushed  up  so  close  to  the 


;|ii 


236 


MINT. 


i 


dicbox  that  their  jaws  enter  a  hollow,  which  brings  thcmnear  the  dies,  enabling  them 
to  seize  the  end  of  the  slip  of  metal  introduced  between  theni  by  the  action  of  the  pre- 
paratory rollers.  The  boy  now  holds  the  handle  s  on  the  top  of  the  pincers  fast,  and  with 
his  olhei  hand  draws  the  handle  x  backwards.  Thus  the  jaws  are  closed,  and  the  metal 
firmly  <niped.  He  now  presses  down  the  handle  x  till  a  hook  on  the  under  side  of  the 
pincers%eizes  the  endless  chain  as  it  moves  along,  when  it  carries  the  pincers,  and  their 
slip  of  metal,  onwards  with  it.  Whenever  the  whole  length  of  the  metallic  riband  has 
passed  through  between  the  dies,  the  strain  on  the  pincers  is  suddenly  relieved,  which 
causes  the  weight  r  to  raise  their  hook  out  of  the  chain,  and  stop  their  motion.  The  ma- 
chine in  the  mint  has  two  sets  of  dies,  and  two  endless  chains,  as  represented  in  the  plan, 
Ae,  979.  N  N,  are  toothed  wheels  in  the  upper  end  of  the  die-box,  furnished  with  pinions 
ind  levers,  for  turning  them  round,  and  adjusting  the  distance  between  the  dies.  A  large 
spur-wheel  g,  is  fixed  upon  the  axis  r,  to  give  motion  to  the  endless  chains ;  see  both 
figures.  This  spur-wheel  is  turned  by  a  pinion  h,  fixed  upon  an  axis  7n,  extending  acro^ 
the  top  of  the  frame,  and  working  in  bearings  at  each  end.  A  spur-wheel  i,  is  fixed 
flpon  the  axis  m,  and  works  into  the  teeth  of  a  pinion  k,  upon  a  second  axis  across  the 
frame,  which  carries  likewise  a  drum  wheel  l,  through  which  motion  is  communicated  to 

the  whole  mechanism  by  an  endless  strap.  .    /•  .        .  » 

The  cutting-out  machine  is  exhibited  in^ig.  980.    a  a  is  a  basement  «*^stone  to  support 

an  iron  plate  b  b,  on  which  stand  the 
columns  c  c,  that  bear  the  upper  part 
D  of  the  frame.  The  iron  frame  of  the 
machine  e,  f,  e,  is  fixed  down  upon 
the  iron  plate  b,  b.  The  punch  d  is  fix- 
ed in  the  lower  part  of  the  innei  frame, 
and  is  moved  up  and  down  by  ihe  screw 
a,  which  is  worked  by  wipers  turned 
by  a  steam  engine,  impelling  the  lever 
H,  and  turning  backwards  and  forwards 
the  axis  g,  through  a  sufficient  space 
for  cutting  the  thickness  of  the  metallic 
lamina.  A  boy  manages  this  machine. 
There  are  twelve  of  them  mounted  on 
the  same  basement  frame  in  a  circular 
range  contained  in  an  elegant  room, 
lighted  from  the  roof.  The  whole  are 
moved  by  a  steam  engine  of  16  horse 
power. 

The  blanks  or  p]anchefs  thus  cut  out, 

„ .„.,.. , ..,, , , were    formerly   adjusted   by  filing   the 

edges,  to  bring  them  to  the  exact  weight;  a  step  which  Mr.  Barton's  ingenious  mechanism 
has  rendered  in  a  great  measure  unnecessary.  The  edge  is  then  milled,  by  a  process 
which  Mr.  Boulton  desires  to  keep  secret,  and  which  is  therefore  not  shown  m  our  mint. 
But  the  French  mint  employs  a  very  elegant  machine  for  the  purpose  of  lettenng 
or  milling  the  edges,  called  the  cardan  des  mannaics,  invented  by  M.  Gengembre,  which 
lias  entirely  superseded  the   older  milling  machine  of  M .  Castamg,  described  m   the 

Encyclopedias.  The  Napoleon  coins  of  France  bear  on  the 
edge,  in  sunk  letters,  the  legend,  Dieu  protlge  la  France ;  and 
those  of  the  king,  Domine  salvumfac  regem.  This  is  marked 
before  striking  the  blank  or  flan.  One  machine  imprints 
this  legend,  and  its  service  is  so  prompt  and  easy,  that  a 
single  man  marks  in  a  day  20,000  pieces  of  5  francs,  or 
100,000  francs. 

Each  of  the  two  arc  dies  e,  d,  (fig.  981,)  carries  one  half 
of  the  legend,  engraved  in  relief  on  the  curved  face ;  these 
arcs  are  pieces  of  steel  tempered  very  hard,  and  fixed  with 
two  screws,  one  immoveably  at  e,  on  the  sill  which  bears  the 
apparatus  ;  the  other  at  d,  at  the  extremity  of  the  lever  p,  d, 
which  turns  round  the  axis  c.  The  letters  of  these  demi- 
legendsare  exactly  parallel,  and  inscribed  in  an  inverse  order 
on  the  dies.  An  alternating  circular  motion  is  communi- 
cated to  the  handle  p.  The  curvatures  of  the  two  dies  are 
arcs  of  circles  described  from  the  centre  c  ;  and  the  interval 
which  separates  them,  or  the  difference  of  the  radii,  is  pre- 
u  cisely  the  diameter  of  the  piece  to  be  milled. 

As  the  centre  c  sustains  the  whole  strain  of  the  milling,  and  produces,  of  consequence, 
t  hard  friction,  this  axis  must  possess  a  considerable  size.    It  is  composed  of  a  squat 


MIRRORS. 


237 


truncated  cone  of  tempered  steel,  which  enters  into  an  eve  of  the  moveable  piece  p,  d. 
This  cone  is  kept  on  the  plate  of  the  metal  n  n,  which  bears  the  whole  machine,  by  a 
nut,  whose  screw,  by  being  tightened  or  slackened,  gives  as  much  freedom  as  is  requisite 
for  the  movement  of  rotation,  or  removes  the  shake  which  hard  service  gives  to  the  cone 
in  Us  eye.  The  middle  thickness  of  the  hole  of  the  moveable  piece  p,  d,  and  the  axis  of 
the  lever  p,  which  terminates  it,  are  exactly  on  a  level  with  the  engraved  letters  of  the 
die,  so  that  no  strain  can  derange  the  moveable  piece,  or  disturb  the  centre  by  its  oscil- 
lations. 

At  a  is  a  vertical  tube,  containing  a  pile  of  blanks  for  milling.  It  is  kept  constantly 
full ;  the  tube  being  open  at  both  ends,  a  little  elevated  above  the  circular  space  o- 
K,  6,  which  separates  the  dies,  and  fixed  by  a  tail  tn  with  a  screw  to  the  motionlest 
piece  A,  B.  The  branch  i,  c,  moveable  with  the  piece  p,  d,  passes  under  the  tube,  and 
pushes  before  it  the  blank  at  the  bottom  of  the  column,  which  is  received  into  a  small 
excavation  in  the  form  of  a  circular  step,  and  carried  forwards.  Matters  are  thus  so 
arranged  as  to  regulate  the  issue  of  the  blanks,  one  by  one,  on  the  small  step  called  the 
posoir  (bed.) 

As  soon  as  the  blank  is  pushed  forwards  into  contact  with  the  lower  edge  of  the 
engraved  grooves,  it  is  seized  by  them,  and  carried  on  by  the  strain  of  milling,  without 
exposing  the  upper  or  under  surfaces  of  the  blank  to  any  action  which  may  obs'truct  the 
printing  on  its  edge. 

The  blank  is  observed  to  revolve  between  the  two  dies  according  as  the  lever  p  com- 
pletes its  course,  and  this  blank  passing  from  a  to  k,  then  to  6,  meets  a  circular  aperture 
b,  through  which  it  falls  into  a  drawer  placed  under  the  sill. 

The  range  of  the  moveable  lever  p  is  regulated  by  four  pieces,  p,  f,  f,  f,  solidly  sunk  in 
the  plate  n,  k,  which  bears  the  whole  apparatus.  A  stud  placed  on  this  lever  towards  d, 
makes  the  arm  of  the  posoir  i  c  retire  no  farther  than  is  necessary  for  the  little  blank  to 
issue  from  the  column ;  and  a  spring  fixed  to  the  centre  c,  and  supported  on  a  peg,  brink's 
back  the  potoir ;  so  that  when  a  screw  i  comes  to  strike  against  the  column,  the  pos^r 
stops,  and  the  moveable  die  d,  which  continues  its  progress,  finds  the  blank  in  a  fit 
position  for  pressing,  seizing,  and  carrying  it  on,  by  reaction  of  the  fixed  die  e.  Thus 
the  edge  of  the  blank  is  lettered  in  half  a  second.  A  hundred  may  easily  be  marked  in 
about  three  minutes. 

The  coining  press  is  the  most  beautiful  part  of  the  whole  mechanism  in  the  British 
mint ;  but  the  hmits  of  this  volume  will  not  allow  of  its  being  figured  upon  an  adequate 
scale.     An  engraving  of  it  may  be  seen  in  the  Encyclopedia  Britannica. 

The  only  attention  which  this  noble  machine  requires  is  that  of  a  little  boy,  who  stands 
in  a  sunk  place  before  the  press,  and  always  keeps  the  tube  full  of  blanks.  He  has  two 
strings,  one  of  which,  when  pulled,  will  put  the  press  in  motion  by  the  concealed  me- 
chanism m  the  apartment  above;  and  the  other  string,  when  snatched,  stops  the  press. 
Ihis  coining  operation  goes  on  at  the  rate  of  60  or  70  strokes  per  minute;  and  with 
very  few  interruptions  during  the  whole  day.  The  press-room  at  the  Royal  Mint 
contains  eight  machines,  all  supported  on  the  same  stone  base  ;  and  the  iron  beams  be- 
tween the  columns  serve  equally  for  the  presses  on  each  side.  The  whole  has  therefore 
a  magnificent  appearance.  The  eight  presses  will  strike  more  than  19,000  coins  in  an 
hour,  with  only  a  child  to  supply  each.  The  grand  improvement  in  these  presses  con- 
sists; 1.  in  the  precision  with  which  they  operate  to  strike  every  coin  with  equal  force, 
which  could  not  be  ensured  by  the  old  press  impelled  by  manual  labor ;  2.  The  rising 
collar  or  steel  ring  in  which  they  are  struck,  keeps  them  all  of  one  size,  and  makes  a  fair 
edge,  which  was  not  the  case  with  the  old  coins,  as  they  were  often  rounded  and  defaced 
by  the  expansion  of  the  metal  under  the  blow;  3.  The  twisting  motion  of  the  upper 

iL'f  i     u:r\^''?''?^."*'^*  ^^"^'^  ^'''^^''^  ^'^  ^^^  ***'  P*rts  of  the  coin  ;  but  this  is  some- 
wnai  doubtful;  4.  The  feeding  mechanism  is  very  complete,  and  enables  the  machine 

i^nT  JT''^  **  uJ'^f  ****"  ^^^  ""^^  P""^^^  ^'^^  ^*»^''«  *^e  workman,  being  in  constant 
Ganger  ol  having  his  fingers  caught,  was  obliged  to  proceed  cautiously,  as  weU  as  to  place 
the  com  true  on  the  die,  which  was  seldom  perfectly  done.  The  feeding  mechanism  of 
the  above  pre&s  is  a  French  invention;  but  Mr.  Boulton  is  supposed  to  have  improved 

MIRRORS.     See  Copper  and  Glass. 
MISPICKEL  is  arsenical  pyrites. 

in  S Minor!  '^^  *'''^''^*  ^"""^  '^^'''^  inhabits  the  mountains  in  the  vicinity  of  Angora, 

v.^P^«fi'5  ^^"^^^^^^^^^  '^*"«*  '"^  '^'^  *^o""tn^  crystallized  tin-plate,  is  a 
variegated  primrose  appearance,  produced  upon  the  surface  of  tin-plate,  by  applying  to  it 
maheaed  state  some  dUute  nitro-muriatic  acid  for  a  few  seconds,  then  washing  it 
with  wa  er,  dryin^and  coating  it  with  lacker.  The  figures  are  more  or  less  blan- 
tiful  and  diversified,  according  to  the  degree  of  heat,  and  relative  dilution  of  the  acid, 
ihis  mode  of  ornamentmg  tin-plate  is  much  less  in  vogue  now  than  it  was  a  few  years  ago. 


288 


MORDANT. 


MORDANT. 


239 


y  i 


MOLASSE  is  a  sandstone  belonging  to  the  tertiary  strata,  employed  under  that  name 

by  the  Swiss  lor  building.  ,..,,.  v  i.  j    •      r  »»»<*•* 

MOLASSES  is  the  brown  viscid  uncrystalhzable  liquor,  which  drains  from  cane  sugar 

in  the  colonies.     See  Sugak.  ,     .  •  v        ,«.  ;« 

MOLYBDENUM  {Molybdlne,  Fr. ;  Molyhdan,  Germ.)  is  a  rare  metal  which  occurs  in 
nature  sometimes  as  a  sulphuret,  sometimes  as  molybdic  ac.J,  and  at  others  as  molybdate 
of  lead.  Its  reduction  from  the  acid  state  by  charcoal  requires  a  vcr}' high  heat,  and 
affords  not  very  satisfactory  results.  When  reduced  by  passing  hydrogen  over  the  igni- 
ted acid,  it  appears  as  an  ash-gray  powder,  susceptible  of  acquiring  metallic  lustre  by 
bein''  rubbed  with  a  steel  burnisher ;  when  reduced  and  fused  with  charcoal,  it  possesses 
a  silver  white  color,  is  very  brilliant,  hard,  brittle,  of  specific  gravity  8-6  ;  it  melts  ma 
powerful  air-furnace,  oxydizes  with  heat  and  air,  burns  at  an  intense  heat  into  molybdic 
acid,  dissolves  in  neither  dilute  sulphuric,  muriatic,  nor  fluoric  acids,  but  in  the  concen- 
trated sulphuric  and  nitric.  ^  ,      .     .       j 

The  protoxyde  consists  of  85-69  of  metal,  and  14-31  of  oxygen ;  the  deutoxyde  con- 
sists  of  75  of  metal,  and  25  of  oxyeen  ;  and  the  peroxyde,  or  molybdic  acid,  of  66-6  of 
metal,  and  33-4  of  oxygen.    These  substances  are  too  rare  at  present  to  be  used  in  any 

"mordant,  in  dveing  and  calico-printing,  denotes  a  body  which,  having  a  twofold 
attraction  for  organic  fibres  and  coloring  particles,  serves  as  a  bond  of  union  between 
Ihem,  and  thus  gives  fixity  to  dyes ;  or  ir  signifies  a  substance  which,  by  combining  with 
coloring  particles  in  the  pores  of  textile  filaments,  renders  them  insoluble  m  hot  soapy 
and  weak  alkaline  solutions.     In  order  properly  to  appreciate  the  utjlity  and  the  true  Junc- 
tions of  mordants.  Aye  must  bear  in  mind  that  coloring  matters  are  peculiar  compounds 
possessed  of  certain  affinities,  their  distinctive  characters  being  not  to  be  either  acid  or 
alkaline,  and  vet  to  be  capable  of  combining  with  many  bodies,  and  especially  with 
salifiable  base's,   and   of  receiving   from   each  of  them   modifications   in   their   color, 
solubility,  and  alterabilitv.       Organic  coloring  substances,  when   pure,  have  a  very 
energetic  attraction  for  certain  bodies,  feeble  for  others,  and  none  at  all  for  some. 
Among  these  immediate  products  of  animal  or  vegetable  life,  some  are  soluble  in  pure 
water,  and  others  become  so  only  through  peculiar  agents.     We  may  thus  readily  con- 
ceive  that  whenever  a  dve-stuflT  possesses  a  certain  affinity  for  the  organic  fibre,  it  wiU 
be  able  to  become  fixed  on  it,  or  to  dye  it  without  the  intervention  of  mordants,  if  it  be 
insoluble  by  itself  in  water,  which,  in  fact,  is  the  case  with  the  coloring  matters  of 
safflower,  annotto,  and  indi-o.     The  first  two  are  soluble  in  alkalis ;  hence,  m  order  to 
use  them,  they  need  only  be  dissolved  in  a  weak  alkaline  ley,  be  thus  applied  to  the 
stuflV,  and  then  have  their  tinctorial   substance  precipitated  within   their  pores,  by 
abstracting  their  solvent  alkali  with  an  acid.     The  coloring  matter,  at  the  mstant  of 
ceasin?  to  be  liquid,  is  in  an  extremely  divided  state,  and  is  in  contact  with  the  organic 
fibres  for  which  it  has  a  certain  affinity.     It  therefore  unites  with  them,  and,  bemg 
naturally  insoluble  in  water,  that  is,  having  no  affinity  for  this  vehicle,  the  subsequent 
washings  have  no   effect  upon   the   dye.       The   same  thing  may  be  said  of  indigo, 
although  its  solubility  in  the  dye-bath  does  not  depend  upon  a  similar  cause,  but  is  due 
to  a  modification  of  its  constituent   elements,  in   consequence  of  which  it   heconies 
soluble  in  alkalis.       Stuffs  plunged  into  this  indigo  bath  get  impregnated  with  the 
solution,  so  that  when  again  exposed  to  the  air,  the  dyeing  substance  resumes  at  once 
its  primitive  color  and  insolubility,  and  washins  can  carry  ofl  only  the  portions  m  ex- 
cess above  the  intimate  combination,  or  which  are  merely  deposited  upon  the  surface  of 

Such  is  the  result  with  insoluble  coloring  matters ;  but  for  those  which  are  soluble 
it  should  be  quite  the  reverse,  since  they  do  not  possess  an  affinity  for  the  organic  fibres, 
which  can  counterbalance  their  affinity  for  water.  In  such  circumstances,  the  dyer 
must  have  recourse  to  intermediate  bodies,  which  add  their  affinity  for  the  coloring 
matter  to  that  possessed  by  the  particles  of  the  stufi;  and  increase  by  this  twofold  action 
the  intimacy  and  the  stability  of  the  combination.    These  intermediate  bodies  are  the 

true  mordants.  „.     .  ,  t  .u-,- 

Mordants  are  in  general  found  among  the  metallic  bases  or  oxydes;  whence  they 
might  be  supposed  to  be  very  numerous,  like  the  metals  ;  but  as  they  must  unite  the  two- 
fold condition  of  possessing  a  strong  affinity  for  both  the  coloring  matter  and  the  organic 
fibre,  and  as  the  insoluble  bases  are  almost  the  only  ones  fit  to  form  insoluble  combina- 
tions, we  may  thus  perceive  that  their  number  may  be  very  limited.  It  is  well  known, 
that  although  lime  and  magnesia,  for  example,  have  a  considerable  affinity  lor  colormg 
particles,  aiid  form  insoluble  compounds  with  them,  yet  they  cannot  be  employed  as  mor- 
dants, because  they  possess  no  affinity  for  the  textile  fibres.  ^  .  „. 
Experience  ha?  proved,  that  of  all  the  bases,  those  which  succeed  best  as  mordants  are 
alumina,  tin,  and  oxyde  of  iron  ;  the  first  two  of  which,  being  naturally  white  are  the 
only  ones  which  can  be  employed  for  preserving  to  the  color  its  original  tmt,  at  leasl 


WithoQt  much  variation.  But  whenever  the  mordant  is  itself  colored,  it  will  cause  the 
aye  to  take  a  compound  color  quite  diflferent  from  its  own.  If,  as  is  usually  said,  the 
mordant  enters  into  a  real  chemical  union  with  the  stuff  to  be  dyed,  the  application  of 
Uie  mordant  should  obviously  be  made  in  such  circumstances  as  are  known  to  be  most 
lavorabie  to  the  combination  taking  place ;  and  this  is  the  principle  of  every  day's  prac- 
tice in  the  dye-house. 

In  order  that  a  combination  may  result  between  two  bodies,  they  must  not  only  be  in 
contact,  but  they  must  be  reduced  to  their  ultimate  molecules.     The  mordants  that  arc 
to  be  united  with  stuffs  are,  as  we  have  seen,  insoluble  of  themselves,  for  which  leason 
their  particles  must  be  divided  by  solution  in  an  appropriate  vehicle.     Now  this  solvent 
or  menstruum  will  exert  in  its  own  favor  an  affinity  for  the  mordant,  which  will  prove 
to  that  extent  an  obstacle  to  its  attraction  for  the  stuff.    Hence  we  must  select  such 
solvents  as  have  a  weaker  affinity  for  the  mordants  than  the  mordants  have  for  the  stuffs. 
Of  all  the  acids  which  can  be  emplojed  to  dissolve  alumina,  for  example,  vinegar  is  the 
one  which  will  retain  it  with  least  energy,  for  which  reason  the  acetate  of  alumina  is 
now  generally  substituted  for  alum,  because  the  acetic  acid  gives  up  the  alumina  with 
such  readiness,  that  mere  elevation  of  temperature  is  sufficient  to  effect  the  separation  of 
these  two  substances.     Before  this  substitution  of  the  acetate,  alum  alone  was  employed  • 
but  without  knowing  the  true  reason,  all  the  French  dyers  preferred  the  alum  of  Rome' 
simply  regarding  it  to  be  the  purest ;  it  is  only  within  these  few  years  that  they  have 
understood  the  real  grounds  of  this  preference.     This  alum  has  not,  in  fact,  the  same  com- 
position as  the  alums  of  France,  England,  and  Germany,  but  it  consists  chiefly  of  cubic 
alum  having  a  larger  proportion  of  base.     Now  this  extra  portion  of  base  is  held  by  the 
sulphuric  acid  more  feebly  than  the  rest,  and  hence  is  more  readily  detached  in  the  form 
of  a  mordant.     Nay,  when  a  solution  of  cubic  alum  is  heated,  this  redundant  alumina 
ftlls  down  in  the  state  of  a  subsulphate,  long  before  it  reaches  the  boiling  point.    This 
difference  had  not,  however,  been  recognised,  because  Roman  alum,  being  usually  soiled 
with  ochre  on  the  surface,  gives  a  turbid  solution,  whereby  the  precipitate  of  subsulphate 
of  alumina  escaped  observation.     When  the  liiuid  was  filtered,  and  crystallized  afresh, 
common  octahedral  alum  alone  was  obtained;   whence  it  was  most  erroneously  concluded, 
that  the  preference  given  to  Roman  alum  was  unjustifiable,  and  that  its  only  sui)eriority 
was  in  being  freer  from  iron. 

Here  a  remarkable  anecdote  illustrates  the  necessity  of  extreme  caution,  before  we 
venture  to  condemn  from  theory  a  practice  found  to  be  useful  in  the  arts,  or  set  about 
changing  it.  When  the  French  were  masters  in  Rome,  one  of  their  ablest  chemists 
was  sent  thither  to  inspect  the  different  manufsictures,  and  to  place  them  upon  a  level 
with  the  state  of  chemical  knowledge.  One  of  the  fabrics,  which  seemed  to  him  furthest 
behindhand,  was  precisely  that  of  alum,  and  he  was  particularly  hostile  to  the  construc- 
tion of  the  furnaces,  in  which  vast  boilers  received  heat  merely  at  their  bottoms,  and 
could  not  be  made  to  boil.  He  strenuously  advised  them  to  be  new  modelled  upon  a 
plan  of  his  own  ;  but,  notwithstanding  his  advice,  which  was  no  doubt  very  scientific,  the 
old  routine  kept  its  ground,  supported  by  utility  and  reputation,  and  very  fortunately, 
too,  for  the  manufacture ;  for  had  the  higher  heat  been  given  to  the  boilers,  no  more 
genuine  cubical  alum  would  have  been  made,  since  it  is  decomposed  at  a  temperature 
of  about  120°  F.,  and  common  octahedral  alum  would  alone  have  been  produced.  The 
ad  li lion  of  a  little  alkali  to  common  alum  brings  it  into  the  same  basic  state  as  the  alum 
of  Rome. 

The  two  principal  conditions,  namely,  extreme  tenuity  of  particles,  and  liberty  of 
action,  being  found  in  a   mordant,  its  operation  is  certain.     But  as  the  combination  to 
be  effected  is  merely  the  result  of  a  play  of  affinity  between  the  solvent  and  the  stuflf  to 
be  dyed,  a  sort  of  partition  must  take  place,  proportioned  to  the  mass  of  the  solvent,  as 
well  as  to  its  attractive  force.     Hence  the  stuff  will  retain  more  of  the  mordant  when 
rts  solution   is  more   concentrated,  that  is,  when   the  base  difiiised  through  it  is  not  so 
much  protected  by  a  large  mass  of  menstruum;  a  fact  applied  to  very  valuable  uses  by 
the  practical  man.     On  impregnating  in  calico  printing,  for  example,  different  spots  of 
the  same  web  with  the  same  mordant  in  different  degrees  of  concentration,  there  is 
obtained  m  the  dye-bath  a  depth  of  color  upon  these  spots  intense  in  proportion  to  the 
strength  of  their  various  mordants.     Thus,  with  solution  of  acetate  of  alumina  in  dif- 
ferent grades  of  density,  and  with  madder,  every  shade  can  be  produced,  from  the  fullest 
red  to  the  lightest  pink ;  and,  with  acetate  of  iron  and  madder,  every  shade  from  black 
to  pale  violet. 

We  hereby  perceive  that  recourse  must  indispensably  be  had  to  mordants  at  different 
stages  of  concentration  ;  a  circumstance  readily  realized  by  varying  the  proportions  of 
the  watery  vehicle.  See  Calico-printixo  and  Madder.  When  these  mordants  are  to 
be  topically  applied,  to  produce  partial  dyes  upon  cloth,  they  must  be  thickened  with 
starch  or  gum,  to  prevent  their  spreading,  and  to  permit  a  sufficient  body  of  them  to 
become  attached  to  the  stuff.    Starch  answers  best  for  the  more  neutral  mordants,  and 


Ill' 


M  ' 


:U> 


'"   .*ii 


?1 


'm>\ 


240 


MORDANT. 


gam  for  the  acidulous ;  but  so  much  of  them  should  never  be  used,  as  to  impede  the 
attraction  of  the  mordant  for  the  cloth.  Nor  should  the  thickened  mordants  be  of  too 
desiccative  a  nature,  lest  they  become  hard,  and  imprison  the  chemical  agent  before  it 
has  had  an  opportunity  of  combining  with  the  cloth,  during  ihe  slow  evaporation  of  its 
water  and  acid.  Hence  the  mordanted  goods,  in  such  a  case,  should  be  hung  up  to 
dry  in  a  gradual  manner,  and  when  oxygen  is  necessary  to  the  fixation  of  the  base,  they 
should  be  largely  exposed  to  the  atmosphere.  The  foreman  of  the  factory  ought,  there- 
fore, to  be  thoroughly  conversant  wilh  all  the  minutiae  of  chemical  reaction.  In  cold 
and  damp  weather  he  must  raise  the  temperature  of  his  dry  ing-house,  in  order  to  com- 
mand a  more  decided  evaporation ;  and  when  the  atmosphere  is  unusually  dry  and 
warm,  he  should  add  deliquescent  correctives  to  his  thickening,  as  I  have  particularized 
in  treating  of  some  styles  of  calico-printing.  But,  supposing  the  application  of  the 
mordant  and  its  desiccation  to  have  been  properly  managed,  the  operation  is  by  no 
means  complete ;  nay,  what  remains  to  be  done  is  not  the  least  important  to  success, 
nor  the  least  delicate  of  execution.  Let  us  bear  in  mind  that  the  mordant  is  intended 
to  combine  not  only  with  the  organic  fibre,  but  afterwards  also  with  the  colonng 
matter,  and  that,  consequently,  it  must  be  laid  entirely  bare,  or  scraped  clean,  so  to 
speak,  that  is,  completely  disengaged  from  all  foreign  substances  which  might  invest  it, 
and  obstruct  its  intimate  contact  wilh  the  coloring  matters.  This  is  the  principle  and 
the  object  of  two  operations,  to  which  the  names  of  duvging  and  clearing  have  been 

If  the  mordant  applied  to  the  surface  (.<  the  cloth  were  completely  decomposed,  and 
the  whole  of  its  base  broucht  into  chemical  union  wilh  it,  a  mere  rinsing  or  scouring  in 
■water  would  suffice  for  removing  the  viscid  substances  added  to  it,  but  this  never 
happens,  whatsoever  precautions  may  be  taken;  one  portion  of  the  mordant  remains 
untouched,  and  besides,  one  part  of  the  base  of  the  portion  decomposed  does  not  enter 
into  combination  wilh  the  stuff,  but  continues  loose  and  superfluous.  All  these  par- 
ticles, therefore,  must  be  removed  without  causing  any  injury  to  the  dyes.  If  in  this 
predicament  the  stuff  were  merely  immersed  in  water,  the  free  portion  of  the  mordant 
would  dissolve,  and  would  combine  indiscriminately  wilh  all  the  parts  of  the  cloth  not 
mordanted,  and  which  should  be  carefully  protected  from  such  combination,  as  well  as 
the  action  of  the  dye.  We  must  therefore  add  to  the  scouring  water  some  substance 
that  is  capable  of  seizing  the  mordant  as  soon  as  it  is  separated  from  the  cloth,  and  of 
forming  with  it  an  insoluble  compound ;  by  which  means  we  shall  withdraw  it  from 
the  sphere  of  action,  and  prevent  its  affecting  the  rest  of  the  stuff,  or  interfering  with  the 
other  dyes.  This  result  is  obtained  by  the  addition  of  cow-dung  to  the  scouring  bath ;  a 
substance  which  contains  a  sufficiently  great  proportion  of  soluble  animal  matters,  and  of 
coloring  particles,  for  absorbing  the  aluminous  and  ferruginous  salts.  The  heat  given  to 
the  dung-bath  accelerates  this  combination,  and  determines  an  insoluble  and  perfectly 

inert  coagulum.  ».,.,. 

Thus  the  dung-bath  produces  at  once  the  solution  of  the  thickening  paste ;  a  more 
intimate  union  between  the  alumina  or  iron  and  the  stuff,  in  proportion  to  its  elevation 
of  temperature,  which  promotes  that  union;  an  effectual  subtraction  of  the  undecomposed 
and  superfluous  part  of  the  mordant,  and  perhaps  a  commencement  of  mechanical  separa- 
tion of  the  particles  of  alumina,  which  are  merely  dispersed  among  the  fibres ;  a  separa- 
tion, however,  which  can  be  completed  only  by  the  proper  scouring,  which  is  done  by  the 
dash-wheel  with  such  agitation  and  pressure  (see  Bleaching  and  Dukgikg)  as  vastly 
facilitate  the  expulsion  of  foreign  particles.     See  also  Bran. 

Before  concluding  this  article,  we  may  say  a  word  or  two  about  astringents,  and 
especially  gall-nuts,  which  have  been  ranked  by  some  writers  among  mordants.  It  is 
rather  difficult  to  account  for  the  part  which  they  play.  Of  course  we  do  not  allude  to 
their  operation  in  the  black  dye,  where  they  give  the  well  known  purple-black  color 
with  salts  of  iron  ;  but  to  the  circumstance  of  their  employment  for  madder  dyes,  and 
especially  the  Adrianople  red.  All  that  seems  to  be  clearly  established  is,  that  the 
asUingent  principle  or  tannin,  whose  peculiar  nature  in  this  respect  is  unknown,  com- 
bines like  mordants  with  the  stuffs  and  the  coloring  substance,  so  as  to  fix  it ;  but  as  this 
tannin  has  itself  a  brown  tint,  it  will  not  suit  for  white  grounds,  though  it  answers  quite 
well  for  pink  grounds.  When  white  spots  are  desired  upon  a  cloth  prepared  with  oil  and 
galls,  they  are  produced  by  an  oxygenous  discharge,  effected  either  through  chlorme  oi 

chromic  acid.  .  v        v*  i. 

MORDANT  is  also  the  name  sometimes  given  to  the  adhesive  matter  by  wnicn 
gold-leaf  is  made  to  adhere  lo  surfaces  of  wood  and  metal  in  gilding.  Paper,  vellum, 
taffety,  &c.,  are  easily  gilt  by  the  aid  of  different  mordants,  such  as  the  following  :  1. 
beer  in  which  some  honey  and  gum  arable  have  been  dissolved ;  2.  gum  arable,  sugar, 
and  water;  3.  the  viscid  juice  of  onion  or  hyacinth,  strengthened  with  a  little  gum 
arable.  When  too  much  gum  is  employed,  the  silver  or  gold  leaf  is  apt  to  crack  in 
the  drying  of  the  mordant.  ^  A  Uttle  carmine  should  be  mixed  with  the  above  colorless 


MOROCCO. 


241 


liquids,  to  mark  the  places  where  they  are  applied.  The  foil  is  applied  by  means  of  « 
dossil  of  cotton  wool,  and  when  the  mordant  has  become  hard,  the  foil  is  polished  with 
the  ^>ame. 

The  best  medium  for  sticking  gold  and  silver  leaf  to  wood  is  the  following,  called  mix- 
tion by  the  French  artists : — 1  pound  of  amber  is  to  be  fused,  with  4  ounces  of  mastic  io 
tears,  and  1  ounce  of  Jewish  pitch,  and  the  whole  dissolved  in  1  pound  of  linseed  oil  ren- 
dered drying  by  litharge. 

Painters  in  distemper  sometimes  increase  the  effect  of  their  work,  by  patches  of  gold 
leaf,  which  they  place  in  favorable  positions;  they  employ  the  above  mordant.  The 
manufacturers  of  paper  hangings  of  the  finer  kinds  attach  gold  and  silver  leaf  to  them  by 
the  same  varnish. 

MOROCCO.    See  Leathkr. 

MORPHIA  (Morphine,  Fr. ;  Moi-phin,  Germ.)  is  a  vegeto-alkali  which  exists  asso- 
ciated with  opian,  codeine,  narcotine,  meconine,  meconic  acid,  resin,  gum,  bassorine  lig- 
nine,  fat  oil,  caoutchouc,  extractive,  &.c.  in  opium.  Morphia  is  prepared  as  follows; 
Opium  in  powder  is  to  be  repeatedly  digested  with  dilute  muriatic  acid,  slightly  heated, 
and  sea-salt  is  to  be  added,  to  precipitate  the  opian.  The  filtered  liquid  is  to  be  super- 
saturated with  ammonia,  which  throws  down  the  morphia,  along  with  the  meconine.  resin, 
and  extractive.  The  precipitate  is  to  be  washed  with  water,  heated,  and  dissolved  in 
dilute  muriatic  acid ;  the  solution  is  to  be  filtered,  whereby  the  foreign  matters  are  sepa- 
rated from  the  salt  of  morphia,  which  concretes  upon  cooling,  whilr  the  meconine  remains 
in  the  acid  liquid.  The  muriate  of  morphia  having  been  squeezed  between  folds  of  blot- 
ting pai)er,  is  lo  be  sprinkled  with  water,  again  squeezed,  next  dissolved  in  water,  and 
decomposed  by  water  of  ammonia.  The  precipitate,  when  washed,  dried,  dissolved  in 
alcohol,  and  crystallized,  i»  morphia. 

These  oiystals,  which  contain  6-32  per  cent,  of  combined  water,  are  transparent,  color- 
less, four-sided  prisms,  without  smell,  and  nearly  void  of  taste,  fusible  at  a  moderate  heat, 
and  they  concrete  into  a  radiated  translucent  mass,  but  at  a  higher  temperature  they 
grow  purple-red.  Morphia  consists  of  72*34  of  carbon  ;  6*366  of  hydrogen  j  5  of  azote ; 
and  16-3  of  oxygen.  It  burns  wilh  a  red  and  very  smoky  flame,  is  stained  red  by  nitne 
acid,  is  soluble  in  30  parts  of  boiling  anhydrous  alcohol,  in  600  parts  of  boiling  water,  but 
hardly  if  at  all  in  cold  water,  and  is  insoluble  in  ether  and  oils.  The  solutions  have  a 
strong  bitter  taste,  and  an  alkaline  reaction  upon  litmus  paper.  The  saline  com- 
pounds have  a  bitter  taste,  are  mostly  cryslallizable,  are  soluble  in  water  and  alcohol 
(but  not  in  ether),  and  give  a  blue  color  to  the  peroxyde  salts  of  iron.  It  is  a  very  poi- 
sonous substance.  Acetate  of  morphia  is  sometimes  prescribed,  instead  of  opium,  in 
medicine. 

Preparation  of  Morphia, — The  aqueous  extract  of  opium  is  to  be  concentrated  by 
evaporation,  and  mixed  with  chloride  of  tin,  till  no  further  precipitate  appears.  The 
liquid  is  then  allowed  to  settle,  is  poured-off,  the  precipitate  is  washed,  and  the  wash- 
ings mixed  with  the  poured-off  liquid.  To  this  mixture  is  then  added  ammonia,  and 
the  precipitate  which  it  produces  is  to  be  digested  with  ether,  in  order  to  remove  the 
narcotine ;  and  then  w  ith  alcohol,  as  long  as  the  latter  acquires  a  bitter  taste.  The 
alcohol  being  then  partially  removed  by  distillation,  the  pure  morphia  is  obtained  in 
the  form  of  crystals. 

MORTAR,  HYDRAULIC,  called  also  Roman  Cement,  is  the  kind  of  mortar  used  for 
building  piers,  or  walls  under  or  exposed  to  water,  such  as  those  of  harbors,  docks,  Ac 
The  poorer  sorts  of  limestone  are  best  adapted  for  this  purpose,  such  as  contain  from  8 
to  25  per  cent  of  foreign  matter,  in  silica,  alumina,  magnesia,  <fec.  These  though  cal- 
cined, do  not  slake  when  moisted;  but  if  pulverized  they  absorb  water  without  swell- 
ing up  or  heating,  like/a<  lime,  and  afford  a  paste  which  hardens  in  a  few  days  under 
water,  but  in  the  air  they  never  acquire  much  solidity.  Smeaton  first  discovered  these 
remarkable  facts,  and  described  them  in  1759. 

The  following  analyses  of  different  hydraulic  limestones,  by  Berthier,  merit  confi- 
dence [see  next  page] : — 

No.  1  18  from  the  fresh-water  lime  formation  of  Chateau-Landon,  near  Nemours ;  Na 
2,  the  large-grained  limestone  of  Paris ;  both  of  these  afford  a  fat  lime  when  burnt. 
Dolomite  affords  a  pretty  fat  lime,  though  it  contains  42  per  cent,  of  carbonate  of  mag- 
nesui;  No.  3,  is  a  limestone  from  the  neighborhood  of  Paris,  which  yields  a  poor  lime, 
possessmg  no  hydraulic  property ;  No.  4  is  the  secondary  limestone  of  Metz;  No.  6  is 
the  lime  marl  of  Senonches,  near  Dreux;  both  the  latter  have  the  property  of  harden- 
ing under  water,  particularly  the  last,  which  is  much  used  at  Paris  on  this  account 

All  good  hydraulic  mortars  must  contain  alumina  and  silica ;  the  oxides  of  iron  and 
manganese,  at  one  time  considered  essential,  are  rather  prejudicial  ingredienta  By 
adding  silica  and  alumina,  or  merely  the  former,  in  certain  circumstances,  to  fat  lime, 
a  water-cement  may  be  artificially  formed ;  as  also  by  adding  to  lime  any  of  the  follow- 
ing native  productions,  which  contain  silicates ;  puzzolana,  trass  or  tarras,  pumice-stone^ 
basalt-tuff,  slate-clay.  Puzzolana  is  a  volcanic  product,  which  forma  hills  of  consider- 
VoL.  IL  16 


243 


MORTAR,  HTDRAULIO. 


A-  Analyses  of  limestones. 
Carbonate  of  lime 
Corbouate  of  magnesia  - 
Carbonate  of  protoxide  of  iron 
Carbonate  of  manganese 
Silica  and  alumina 
Oxide  of  iron        -        -        - 

Nal 

NaSL 

Naa 

No.  4.             Nafc 

97-0 
2-0 

10 

98-6 
1-5 

74-5 
23-0 

1-2 

76-5 
3-0 
8-0 
1-6 

15-2 

80-0 
1-6 

18-0 

1000 

100-0 

100-0 

100-0 

100-0 

B.  Analyses  of  the  burnt  lime. 
Lime     -        -        -        -        - 
Magnesia       -        -        -        . 
Alumina        -         -         -        - 
Oxide  of  iron         -        -        . 

96.4 
1-8 
1-8 

97-2 
2-8 

78-0 

20-0 

2-0 

68-3 
2  0 

24  0 
5-7 

70-0 

1-0 

29-0 

100-0 

100-0         100-0 

1 

100-0 

100-0 

able  extent  to  the  south-west  of  the  Appenines,  in  the  district  of  Rome,  the  Pontine 
marshes,  Viterbo,  Bolsena,  and  in  the  Neapolitan  region  of  Pozzuolo,  whence  the  name. 
A  similar  volcanic  tufa  is  found  in  many  other  parts  of  the  world.  According  to 
Berthier,  the  Italian  puzzolana  consists  of  44-5  silica;  15-0  alumina;  8-8  lime;  4-7 
magnesia;  1-4  potash;  4-1  soda;  12  oxides  of  iron  and  titanium;  9-2  water;  in  100 
parts. 

The  tufa  slone,  which  when  ground  forms  irassy  is  composed  of  57*0  silica,  16-0  clay, 
2*6  lime,  1*0  magnesia,  7*0  potash,  1"0  soda,  5  oxydes  of  iron  and  titanium,  9-6  water. 
This  tuff  is  found  abundafntly  filling  up  valleys  in  beds  of  10  or  20  feet  deep,  in  the  north 
of  Ireland,  among  the  schistose  formations  upon  the  banks  of  the  Rhine,  and  at  Mon- 
heim  in  Bavaria. 

The  fatter  the  lime,  the  less  of  it  must  he  added  to  the  ground  puzzolana  or  trass,  to 
form  a  hydraulic  mortar ;  the  mixture  should  be  made  extemporaneously,  and  must  at  any 
rate  be  kept  dry  till  about  to  be  applied.  Sometimes  a  proportion  of  common  sand  mor- 
tar instead  of  lime  is  mixed  with  the  trass.  When  the  hydraulic  cement  hardens  too 
soon,  as  in  12  hours,  it  is  apt  to  crack ;  it  is  better  when  it  takes  8  days  to  concrete. 
Through  the  agency  of  the  water,  silicates  of  lime,  alumina,  (magnesia,)  and  oxyde  of 
iron  are  formed,  which  assume  a  stony  hardness. 

Besides  the  above  two  volcanic  products,  other  native  earthy  compounds  are  used  in 
making  water  cements.  To  this  head  belong  all  limestones  which  contain  from  20  to 
30  per  cent,  of  clay  and  silica.  By  gentle  calcination,  a  portion  of  the  carbonic  acid  is 
expelled,  and  a  little  lime  is  combined  with  the  clay,  while  a  silicate  of  clay  and  lime 
results,  associated  with  lime  in  a  subcarbonated  stale.  A  lime-marl  containins;  less  clay 
will  bear  a  stronger  calcining  heat  without  prejudice  to  its  qualities  as  a  hydraulic 
cement ;  but  much  also  depends  upon  the  proportion  of  silica  present,  and  the  physical 
structure  of  all  the  constituents. 

The  mineral  substance  most  used  in  England  for  making  such  mortar  is  vulgarly 
called  cement-stone.  It  is  a  reniform  limestone,  which  occurs  distributed  in  single  nodules 
or  rather  lenticular  cakes,  in  beds  of  clay.  They  are  mostly  found  in  those  argillaceous 
strata  which  alternate  with  the  limestone  beds  of  the  oolite  formation,  as  also  in  the 
clay  strata  above  the  chalk,  and  somelimes  in  the  London  clay.  On  the  coasts  of  Kent, 
in  the  isles  of  Sheppey  and  Thanet,  on  the  coasts  of  Yorkshire,  Somersetshire,  and  the 
Isle  of  Wight,  &c.,  these  nodular  concretions  are  found  in  considerable  quantities,  having 
been  laid  bare  by  the  action  of  the  sea  and  weather.  They  were  called  by  the  older 
mineralogists  Septaria  and  Ludus  Helmontii  (Van  Helmont's  coits.)  When  sawn  across, 
they  show  veins  of  calc-spar  traversing  the  silicious  clay,  and  are  then  sometimes  placed 
in  the  cabinets  of  virtuosi.  They  are  found  also  in  several  places  on  the  .Continent,  as 
at  Neustadt-Eberswalde,  near  Antwerp,  near  Altdorf  in  Bavaria;  as  also 'at  Boulogne- 
sur-mer,  where  they  are  called  Boulogne-pebbles  (galets).  These  nodules  vary  in  size 
from  that  of  a  fist  to  a  man's  head ;  they  are  of  a  yellow-gray  or  brown  color,  inter- 
spersed with  veins  of  calc-spar,  and  sometimes  contain  cavities  bestudded  with  crystals. 

Their  specific  gravity  is  2*59. 

Analyses  of  several  cement-stones,  and  of  the  cement  made  with  them : 


MORTAR,  HYDRAULIO. 


Mi 


A.  Constituents  of  the  cement- 

NaL 

No.  2. 

No.  8. 

Na4. 

NaCi 

stones. 

Carbonate  of  lime 

66-7 

61-6 

• 

82-9 

63-8 

—           magnesia  - 

0-5 

- 

*              m 

. 

1-5 

—            protoxide  of  iron 

6-0 

6-0 

m              » 

\       4-3 

11-6 
14-0 

—            manganese 

1-6 

- 

. 

Silica 

18-0 

15-0 

„              „ 

13-0 

Alumina  or  clav   -        -        - 

6-6 

4-8 

*              • 

trace 

6-7 

Oxide  of  iron 

»             m 

3-0 

Water 

1-2 

6-6 

-               ' 

-     - 

9-4 

B.  Constituents  of  the  cement. 

Lime    ----- 

66-4 

64-0 

66-0 

•     • 

56*6 

Magnesia      .        .        -        . 

- 

- 

«     „ 

l-l 

Alumina  or  clay   -        -        - 

360 

31-0 

38-0 

.     . 

21-0 

Oxide  of  iron        -       ^        - 

8-6 

15-0 

18-0 

-     - 

13-7 

No.  I.  English  cement-stone,  analyzed  by  Berthier;  No.  2.  Boulogne  stone,  by  Dr»- 
piez ;  No.  3.  English  ditto,  by  Davy ;  No.  4.  reniform  limestone  nodules  from  Arkona, 
by  Hiahnefeld;  No.  5.  cement-stone  of  Avallon,  by  Dumas. 

In  England  the  stones  are  calcined  in  shaft-kilns,  or  sometimes  in  mound  kilns,  then 
ground,  sifted,  and  packed  in  casks.  The  color  of  the  powder  is  dark-brown-red.  When 
made  into  a  thick  paste  with  water,  it  absorbs  little  of  it,  evolves  hardly  any  heat,  and 
soon  indurates.  It  is  mixed  with  sharp  sand  in  various  proportions,  immediately  before 
using  it;  and  is  employed  in  all  marine  and  river  embankments,  for  securing  the  seams 
of  stone  or  brick  floors  or  arches  from  the  percolation  of  moisture,  and  also  for  facing 
walls  to  protect  them  from  damp. 

The  cement  of  Pouilly  is  prepared  from  a  Jurassic  (secondary)  limestone,  which  con- 
tains 39  per  cent,  of  silica,  with  alumina,  magnesia,  and  iron  oxyde.  Vicat  forms  a  fac- 
titious Roman  cement  by  making  bricks  with  a  pasty  mixture  of  4  parts  of  chalk,  and  1 
part  of  dry  clay,  drying,  burning,  and  grinding  them.  River  sand  must  be  added  to  this 
powder;  and  even  with  this  addition,  its  efficacy  is  somewhat  doubtful ;  though  it  has, 
for  want  of  a  better  substitute,  been  much  employed  at  Paris. 

The  cement  of  Dihl  consists  of  porcelain  or  salt-glaze  potsherds  ground  fine,  and 
mixed  with  boiled  linseed  oil. 

Hamelin's  mastic  or  lithic  paint  to  cover  the  facades  of  brick  buildings,  &c.,  is  com- 
posed of  50  measures  of  silicious  sand,  50  of  lime-marl,  and  9  of  litharge  or  red-lead 
ground  up  with  linseed  oil. 

Professor  Kuhlmann,  of  Lisle,  obtained  a  patent  in  April,  1841,  in  the  name  of  Mr. 
Newton,  for  certain  improvements  in  the  manufacture  of  lime-cement  and  artificial 
stone ;  and  of  which  he  gave  me  a  sample,  possessed  of  a  hardness  and  solidity  fit  for 
the  sculptor. 

In  operating  by  the  dry  method,  instead  of  calcining  the  limestone  with  sand  and 
clay  alone,  as  has  been  hitherto  commonly  practised,  this  inventor  introduces  a  small 
quantity  of  soda,  or,  preferably,  potash,  in  the  state  of  sulphate,  carbonate,  or  muriate; 
salts  susceptible  of  forming  silicates  when  the  earthy  mixture  is  calcined.  The  alkaline 
salt,  equal  in  weight  to  about  one-fifth  that  of  the  lime,  is  introduced  in  solution  amon« 
the  earths.  ^ 

All  sorts  of  lime  are  made  hj'draulic,  in  the  humid  way,  by  mixing  slaked  lime  with 
solutions  of  common  alum  or  sulphate  of  alumina;  but  the  best  method  consists  in  em- 
ploying a  solution  of  the  silicate  of  potash,  called  liquor  of  flints,  or  soluble  glass,  to 
mix  in  with  the  lime,  or  lime  and  clay.  An  hydraulic  cement  may  also  be  made  which 
will  serve  for  the  manufacture  of  architectural  ornaments,  by  making  a  paste  of  pul- 
verized chalk,  with  a  solution  of  the  silicate  cf  potash.  The  said  liquor  of  flints  like- 
wise gives  chalk  and  plaster  a  stony  hardness,  by  merely  soaking  them  in  it,  afler  they 
are  cut  or  moulded  to  a  proper  shape.  On  exposure  to  the  air,  they  get  progressively 
mdurated.  Superficial  hardness  may  be  readily  procured  by  washing  over  the  surface 
of  chalk,  Ac,  with  liquor  of  flints,  by  means  of  a  brush.  This  method  affords  an  easy 
and  elegant  method  of  giving  a  stony  crust  to  plastered  walls  and  ceilings  of  apartr 
ments;  as  also  to  statues  and  busts,  cast  in  gypsum,  mixed  with  chalk. 

The  essential  constituents  of  every  good  hydraulic  mortar  are  caustic  lime  and 
silica;  and  the  hardening  of  this  compound  unSer  water  consists  mainly  in  a  chemical 
combination  of  these  two  constituents  through  the  agency  of  the  water,  producing  % 


I 


!»4 


MOTHER  OF  PEARL. 


hydrated  silicate  of  lime.  But  such  mortars  maj  contain  other  bases  besides  lime,  as 
for  example  clay  and  magnesia,  whence  double  silicates  of  great  solidity  are  formed ; 
on  which  account  dolomite  is  a  good  ingredient  of  these  mortars.  But  the  silica  must 
be  in  a  peculiar  state  for  these  purpose^s ;  namely,  capable  of  affording  a  gelatinous 
paste  with  acids;  and  if  not  so  already,  it  must  be  brought  into  this  condition,  by  cal- 
cining it  along  with  an  alkali  or  an  alkaline  earth,  at  a  bright  red  heat,  when  it  will 
dissolve,  and  gelatinize  in  acids.  Quartsoze  sand,  however  fine  its  powder  may  be, 
will  form  no  water  mortar  with  lime;  but  if  the  powder  be  ignited  with  the  lime,  it 
then  becomes  fit  for  hydraulic  work.  Ground  felspar  or  clay  forms  with  slaked  lime 
no  water  cement ;  but  when  they  are  previously  calcined  along  with  the  lime,  the 
mixture  becomes  capable  of  hardening  under  water. 

The  mastic  called  HamelirCs,  and  so  much  employed  in  London,  is  composed  of  ground 
Portland  stone  (roe  stone),  sand  and  litharge  in  the  proportion  of  62  of  the  first,  35  of 
the  second,  and  3  of  the  third,  in  100  parts;  but  other  proportions  will  also  answer 
the  purpose.     I  find  that  chalk  will  not  make  a  good  mastic;  being  too  compact  to 

f)ermit  the  air  to  insinuate  between  the  pores,  and  to  produce  the  concretion  of  the 
inseed  oil,  with  which  the  above  mixture  is  worked  up  and  applied.  This  mastic  soon 
acquires  great  hardness,  and  is  totally  impervious  to  water.  The  surface  to  which  it 
IS  to  be  applied  must  be  dry,  and  smeared  over  with  linseed  oil.  Considerable  dexterity 
IS  required  to  make  good  work  with  it.  The  fine  dust  of  sandstone  alone,  mixed  with 
]0  or  12  per  cent,  of  litharge  and  7  per  cent,  of  linseed  oil,  forms  an  excellent  mastic 
Limestone,  which  cont-iins  as  much  as  10  per  cent,  of  clay,  comports  itself  after  cal- 
cination, if  all  the  carbonic  acid  be  expelled,  just  as  pure  limestone  would  do.  "When 
it  is  less  strongly  burned,  it  affords,  however,  a  mass  which  hardens  pretty  speedily 
in  water.  If  the  argillaceous  proportion  of  a  marl  amounts  to  18  or  20  per  cent.,  it  still 
will  slake  with  water,  but  it  will  absorb  less  of  it,  and  forms  a  tolerably  good  hydrau- 
lic naortar,  especially  if  a  little  good  Roman  cement  be  added  to  it.  When  the  pro- 
portion of  clay  is  25  or  30  per  cent,  after  burning,  it  heats  but  little  with  water,  nor 
does  it  slake  well,  and  must  therefore  be  ground  by  stampers  or  an  edge  millstone, 
when  it  is  to  be  used  as  a  mortar.  This  kind  of  marl  yields  commonly  the  best 
water  cement  without  other  addition.  Should  the  quantity  of  clay  be  increased 
farther,  as  up  to  40  per  cent.,  the  compound  will  not  bear  a  high  or  long-continued 
heat  without  being  spoiled  for  making  hydraulic  mortar  after  grinding  to  powder. 
When  more  strongly  calcined,  it  forms  a  vitriform  substance,  and  should,  after  being 
pulverized,  be  mixed  up  with  good  lime,  to  make  a  water  mortar.  If  the  marls,  in 
any  locality,  differ  much  in  their  relative  proportions  of  lime  and  alumina,  as  may  be 
readily  ascertained  by  the  use  of  my  lime-proof  apparatus  (see  Appendix),  then  the 
several  kinds  should  be  mixed  in  such  due  proportions  as  to  produce  the  most 
speedily  setting,  and  most  highly  indurating  hydraulic  cement     See  Soils,  Analysis 

OF. 

MOSAIC  GOLD.  For  the  composition  of  this  peculiar  alloy  of  copper  and  zinc, 
called  also  Or-molu,  Messrs.  Parker  and  Hamilton  obtained  a  patent  in  November,  1825. 
Equal  quantities  of  copper  and  zinc  are  to  be  "  melted  at  the  lowest  temperature  that 
copper  will  fuse,"  which  being  stirred  together  so  as  to  produce  a  perfect  admixture  of 
the  metals,  a  further  quantity  of  zinc  is  added  in  small  portions,  until  the  alloy  in  the 
melting  pot  becomes  of  the  color  required.  If  the  temperature  of  the  copper  be  too  high, 
a  portion  of  the  zinc  will  fly  off  in  vapor,  and  the  result  will  he  merely  spelter  or  hard 
solder ;  but  if  the  operation  be  carried  on  at  as  low  a  heat  as  possible,  the  alloy  will 
assume  first  a  brassy  yellow  color;  then,  by  the  introduction  of  small  portions  of  zinc,  it 
will  take  a  purple  or  violet  hue,  and  will  ultimately  become  perfectly  white ;  which  is 
the  appearance  of  the  proper  compound  in  its  fused  state.  This  alloy  may  be  poured 
into  ingots;  but  as  it  is  difficult  to  preserve  its  character  when  re-melted,  it  should  be 
cast  directly  into  the  figured  moulds.  The  patentees  claim  the  exclusive  right  of  com- 
pounding a  metal  consisting  of  from  52  to  55  parts  of  zinc  out  of  100. 

Mosaic  goldj  the  aurum  musivum  of  the  old  chemists,  is  a  sulphuret  of  tin. 

MOSAIC.  (Mosaiqtie,  Fr. ;  Mosaisch,  Germ.)  There  are  several  kinds  of  mosaic, 
but  all  of  them  consist  in  imbedding  fragments  of  different  colored  substances,  usually 
glass  or  stones,  in  a  cement,  so  as  to  produce  the  effect  of  a  picture.  The  beautiful  cha- 
pel of  Saint  Lawrence  in  Florence,  which  contains  the  tombs  of  the  Medici,  has  been 
greatly  admired  by  artists,  on  account  of  the  vast  multitude  of  precious  marbles,  jaspers, 
agates,  avanturines,  malachites,  &c.,  applied  in  mosaic  upon  its  walls.  The  detailed 
discussion  of  this  subject  belongs  to  a  treatise  upon  the  fine  arts. 

MOTHER  OF  PEARL  {Nacre  de  Perles,  Fr. ;  Perlen  mutter.  Germ.)  is  the  hard, 
silvery,  brilliant  internal  layer  of  several  kinds  of  shells,  particularly  oysters,  which 
is  often  variegated  with  changing  purple  and  azure  colors.  The  large  oysters  of  the 
Indian  seas  alone  secrete  this  coat  of  sufficient  thickness  to  render  their  shells  available 
to  the  purposes  of  manufactures.  The  genus  of  shell  fish  called  pentadina  furnishes 
the  finest  pearls,  as  well  as  mother  of  pearl  j  it  is  found  in  greatest  perfection  round  the 


MURIATIC  ACID. 


245 


I 


coasts  of  Ceylon,  near  Ormus  in  the  Persian  Gulf,  at  Cape  Comorin,  and  among  some 
of  the  Australian  seas.     The  brilliant  hues  of  mother  of  pearl  do  not  depend  upon  the 
nature  of  the  substance,  but  upon  its  structure.    The  microscopic  wrinkles  or  furrows 
which  run  aarosi  the  surface  of  every  slice,  act  upon  the  reflected  light  in  such  a  way  a» 
to  produce  the  chromatic  effect ;  for  Sir  David  Brewster  has  shown,  that  if  we  take,  with 
ver>;  fine  black  wax,  or  with  the  fusible  alloy  of  D'Arcet,  animpifssion  of  mother  of  pearl. 
It  will  possess  the  iridescent  appearance.     Mother  of  pearl  is  very  delicate  to  work, 
but  It  may  be  fashioned  by  saws,  files,  and  drills,  with  the  aid  sometimes  of  a  corrosive 
acid,  such  as  the  dilute  sulphuric  or  muriatic ;  and  it  is  polished  by  colcothar  of  vitriol 
MO  THE  K- WATER  is  the  name  of  the  liquid  which  remains  after  all  the  salts  that 
Will  regularly  crystallize  have  been  extracted,  by  evaporation  and  cooling,  from  any  saline 
solution. 

MOUNTAIN  SOAP  (Savon  de  montagne,  Fr. ;  Bergseife,  Germ.)  is  a  tender  mineral, 
■oft  to  the  touch,  which  assumes  a  greasy  lustre  when  rubbed,  and  falls  to  pieces  in  water. 
It  consists  of  silica  44,  alumina  26-5,  water  20-5,  oxyde  of  iron  8,  lime  0-5.     It  occurs  in  • 
be(*s,  alternating  with  different  sorts  of  clay,  in  the  Isle  of  Skye,  at  Billin  in  Bohemia, 
&.C.     It  has  been  often,  but  improperly,  confounded  with  stratite.  , 

MUCIC  ACID  (Jcide  mucique,  Fr. ;  SchUimsaure,  Germ.)  is  the  same  as  the  saclactic 
acid  of  Scheele,  and  may  be  obtained  by  digesting  one  part  of  gum  arable,  sugar  of  milk, 
or  peclic  acid,  with  twice  or  thrice  their  weight  of  nitric  acid.      It  forms  white  granular  ' 
cr)'«tals,  and  has  not  been  applied  to  any  use  in  the  arts. 

MUCILAGE  is  a  solution  in  water  of  gummy  matter  of  any  kind. 

MUFFLE  is  the  earthenware  case  or  box,  in  the  assay  furnaces,  for  receiving  the  • 
cupels,  and    protecting    them    from    being    disturbed    by  the    fuel.    See  Assay  and 
Furnace. 

MUNDIC  is  the  name  of  copper  pyrites  among  English  minci-s.  * 

MUNJERT  is  a  kind  of  madder  srown  in  several  parts  of  India. 

MURIATIC  or  HYDROCHLORIC  ACID  ;  anciently  manne  acid,  and  npirit  of  »aU, 
(jSctde  hydrocklorique,  and  Chlorhydrique,  Fr. ;  Salzsaure,  Germ.)  This  acid  is  now  extiacU 
ed  from  sea-salt,  by  the  action  of  sulphuric  acid  and  a  moderate  heat ;  but  it  was  originally 
obtained  from  the  salt  by  exposin?  a  mixture  of  it  and  of  common  clay  to  ignition  in  an 
earthen  retort.  The  acid  gas  which  exhales,  is  rapidly  condensed  by  water.  100  cubic 
mches  of  water  are  capable  of  absorbing  no  less  than  48,000  cubic  inches  of  the  acid  • 
gas,  whereby  the  liquid  acquires  a  specific  gravity  of  1-2109  ;  and  a  volume  of  142  cubic 
inches.  This  vast  condensation  is  accompanied  with  a  great  production  of  heat,  whence 
It  becomes  necessary  to  apply  artificial  refrigeration,  especially  if  so  strong  an  acid  as  the 
above  is  to  be  prepared.  In  general,  the  muriatic  acid  of  commerce  has  a  specific  gravity 
varying  from  M5  to  1-20;  and  contains,  for  the  most  part,  considerably  less  than  40 
parts  by  weight  of  acid  gas  in  the  hundred.  The  above  stronger  acid  contains  42-68  per 
cent,  by  weight ;  for  since  a  cubic  inch  of  water,  which  weighs  252-5  grains,  has 
absorbed  480  cubic  inches  =  188  grains  of  gas ;  and  2525  -f  188  =  4405 ;  then 
440-5  :  188  :  :  100  :  42-68.  In  general  a  very  good  approximation  may  be  found  to  the 
per  centage  of  real  muriatic  acid,  in  any  liquid  sample,  by  multiplying  the  decimal 
figures  of  the  specific  gravity  by  200.  Thus  for  example,  at  M62  we  shall  have  by* 
this  rule  0-162  X  200  =  32-4,  for  the  quantity  of  gas  in  100  parts  of  the  liquid.  Muriatic  • 
acid  gas  consists  of  chlorine  and  hydrogen  combined,  without  condensation,  in  equal  vol- 
umes.    Its  specific  gravity  is  1-247,  air  =  1-000. 

By  sealing  up  muriate  of  ammonia  and  sulphuric  acid,  apart,  in  a  strong  glass  tube  re-  ' 
curved,  and  then  causing  them  to  act  on  each  other.  Sir  H.  Davy  procured  liquid  muriatic 
acid.     He  justly  observes,  that  the  generation  of  elastic  substances  in  close  vessels,  either  • 
With  or  without  heat,  ofiers  much  more  powerful  means  of  approximating  their  molecules 
than  those  dependant  on  the  application  of  cold,  whether  natural  or  artificial ;  for  as  gases 
diminish  only  ~L_  m  volume  for  every  degree  of  Fahrenheit's  scale,  beginning  at  ordinary 
temperatures,  a  very  slight  condensation  only  can  be  produced  by  the  most  powerful 
freezing  mixtures,  not  half  as  much  as  would  result  from  the  application  of  a  stron*' 
flame  to  one  part  of  a  glass  tube,  the  other  part  being  of  ordinary  temperature ;  and  when, 
attempts  are  made  to  condense  gases  into  liquids  by  sudden  mechanical  compression,  the 
heat  instantly  generated  presents  a  formidable  obstacle  to  the  success  of  the  experiment; 
whereas  m  the  compression  resulting  from  their  slow  generation  in  close  vessels,  if  the 
process  be  conducted  with  common  precautions,  there  is  no  source  of  difficulty  or  danger: 
and  it  may  be  easily  assisted  by  artificial  cold,  in  cases  where  gases  approach  near  to 
that  point  of  compression  and  temperature  at  which  they  become  vapors.— PAti.  Trans, 

The  muriatic  acid  of  commerce  has  usually  a  yellowish  tinge,  but  when  chemically  pur« 
It  is  colorless.     It  fumes  strongly  m  the  air,  emitting  a  corrosive  vapor  of  a  peculiar  - 
smell.    The  characteristic  test  of  muriatic  acid  in  the  most  dilute  slate,  is  nitrate  of  silver, 
which  causes  a  curdy  precipitate  of  chloride  of  silver. 

The  preparation  of  this  acid  upon  the  great  scale  is  frequently  effected  in  this  ^""•— 


246 


MURIATIC  ACID. 


by  acting  upon  sea-salt  in  hemispherical  iron  pots,  or  in  cast-iron  cvlindere  with  con. 
eentratel  sulphuric  acid ;  taking  6  parts  of  the  saU  to  5  of  the  Icfd  ^ 'Se  ^iTth  V^^^^ 

two  inches  m  diameter  each,  into  the  one  of  which  the  acid  is  poured  bv  a  funnel  in 

5nctZ?hrj;« ''°''  ^''l ^"*'' '^t''^^''  .*  ^""'  «^^'''  ^' Btone-ware tube,  is  Led,  fo^con 
flTriu  A    ^}'^''S^S^^  muriatic  gas  into  a  series  of  large  globes  of  bottle  g  ass  one- 
^  rd  filled  with  water  and  laid  on  a  sloping  sand-bed.     A  wlek  is  commonl^emplov  ed 
for  working  off  each  i>ot ;  no  heat  being  applied  to  it  till  the  second  day.    ^   ^    ^ 
Vr.^X        '^^T''''  °^  ^^"^^^  ^y  sulphuric  acid,  was  at  one  time  earned  on  by  some 
French  manufacturers  m  large  leaden  pans,  10  feet  long,  5  feet  broad,  and  a  foot  dTr! 

TZtZffT'^^  i""1'  «"^  ^"^^-  The  disengaged^acid  gas  was  made  to  circS 
in  a  conduit  of  glazed  bricks,  nearly  650  yards  long,  where  it  was  condensed  by  a  sheet 
f  sW  nf^f  f   9nf '^  '^*"'  which  flowed  slowly  in  the  opposite  direction  of  the  gas  down 

w«l  it  V  ^^^'  ^  ^^^  !"**  ^^  ^^''  '^^"^^  "^^-^^^^  '^^  apparatus,  the  muilalic  acid 
was  as  strong  as  possible,  and  pretty  pure ;  but  towards  the  other  end,  the  water  was 
narUly  acidulous.  The  condensing  part  of  this  apparatus  was  therefore  tolerably  com- 
plete ;  but  as  the  decomposition  of  the  salt  could  not  be  finished  in  the  leaden  pans,  the 
Jfjfr^  ♦"^  ^^  ^"^  be  drawn  out  of  them,  in  order  to  be  completely  decomposed  in  a 
feverberatory  furnace ;  m  this  way  nearly  50  per  cent,  of  the  muriatic  acid  was  lost 
And  besides,  the  great  quantity  of  gas  given  ofl' during  the  emptying  of  the  lead-chamberi 
was  apt  to  suffocate  the  workmen,  or  seriously  injured  their  lungs,  causing  severe 
Lemoptysis.  The  employment  of  muriatic  acid  is  so  inconsiderable,  Lnd  the  loss  of  it 
mcurred  m  the  preceding  process  is  of  so  little  consequence,  that  subsequently,  both  in 
i^^?u  ^f  ■"  E"S^*"^»  sulphate  of  soda,  for  the  soda  manufacture,  has  been  procured 
with  the  dissipation  of  the  muriatic  acid  in  the  air.  In  the  method  more  lately  resorted 
to,  the  gaseous  products  are  discharged  into  extensive  vaults,  where  currents  of  water 
condense  them  and  carry  them  off  into  the  river.  The  surrounding  vegetation  is  thereby 
•aved  m  some  measure  from  being  burned  up,  an  accident  which  was  previouslv  sure  to 
happen  when  fogs  precipitated  the  floating  gases  upon  the  ground.  At  Newcastle 
Liverpool,  and  Marseilles,  where  the  consumption  of  muriatic  Lid  bears  no  pro^rt  in 
to  the  manufacture  of  soda,  this  process  is  now  practised  upon  a  vast  scale.      *^    ^      " 

rhe  apparatus  for  condensing  muriatic  acid  gas  has  been  modified  and  changed,  of 
late  years,  in  many  diflerent  ways.  *     ' 

The   Bastringue  apparatus.     At  the  end  of  a  reverberatory  furnace,  (see  Coppeh. 
•MELTING  OF  and  SoDA,  MANUFACTrKE  OF,)  a  rectangular  lead  trough  or  pan,  about  1  foot 

f  ?'«fr*  7f^  ^"?^  ^^  'i'^.*  ^^  *^^  ^"^^"^•'  «^  '^^  ^"'»»<=e^  ^^^'\  about  5  feet  wide! 
•nd  6^  feet  long,  is  incased  in  masonn',  having  its  upper  edges  covered  with  cast-iron 

frnif' th'  il''  f"*^  ^^^^r^  "P^!!  *  ^^""^^  '""'^^  *^«  P««^?«  «^  the  flame,  as  it  escapes 

from  the  reverberatory.  The  arch  which  covers  that  pan  forms  a  continuation  of  Ihe 
roof  of  the  reverberatory,  and  is  of  the  same  height.  The  flame  which  proceeds  from 
the  furnace  containing  the  mixture  of  salt  and  sulphuric  acid  is  made  to  escape  between 

thlt^ht  Whtn"]^^'^  ""^^^  ••■''"  ?^^'''  ""'  ^'^  '''^^'*  *^^°"=»>  ^  P^^^«?^  «"^y  4  inches 
Zt^&A  ,  ^  5"™*?  *"■  ^""^  '^^P^''"  ^^^^•^  the  extremity  of  the  pan,  they  are 

reflected  downwards  and  made  to  return  beneath  the  bottom  of  the  pan,  in  a  flie,  which 

IL^^K-''^"^'  ^'Z^*^  '°.^\^°  ^^^^  the  smoke  into  two  lateral  flues,  which  terminate  in 
the  chimney.     The  pan  is  thus  surrounded  as  it  were  with  the  heat  and  flame  dischar-ed 
from  the  reverberatory  furnace.      See  Evaporation.     A  door  is  opened  near  the  end'of 
Sr .wu  ^%;,"troducing  the  chaije  of  sea-salt,  amounting  to  12  bags  of  2  cwts.  each,  or 
tJr      1  ^his  door  is  then  luted  on  as  tightly  as  possible,  and  for  every  100  parts  of  salt. 
110  of  sulphuric  acid  are  poured  in,  of  specific  gravity  1-594,  containing  57  per  cent,  of 
dry  acid.      This  acid  is  introduced  through  a  funnel  inserted  in  the  roof  of  the  furnace 
pecomposition  ensues,  muriatic  acid  gas  mingled  with  steam  is  disengaged,  and  is  conl 
ducted  through  4  stone-ware  tubes  into  the  refrigerators,  where  it  is  finally  conden^ 
These  refrigerators  consist  of  large  stone-waie  carboys,  called  dame-jeans  irFmnce  to 
the  number  of  7  or  8  for  each  pipe,  and  arranged  so  thit  the  neck  of  the  one  commun ° 
cates  with  the  body  of  the  other;  thus  the  gas  must  traverse  the  whole  series,  rdZ, 
""^1"^  measure  condensed  by  the  water  in  them,  before  reachin-  the  last 
.    When  the  operation  is  finished,  the  door  opposite  the  pan  is  opened,  and  'the  re«;iduum 
in  It  IS  discharged^in  the  form  of  a  fluid  magma,  upon  a  square  bed  of  br  cks,  exS 

ttl  anTrrVvd^'^r^'L^P^'^^^^""^^"^^^  «"  ^^""-  ^"^  ^^  then  broken  into  fi^! 
mcnts  and  carried  to  the  soda  manufactory.  The  immense  quanlitv  of  gas  exhaled  in 
discharging  the  pan,  renders  this  part  of  the  operation  very Vin/ul  to  Teworkme^^ 
Wd  wasteful  in  reference  to  the  production  of  muriatic  acid.  "^  The  dilBculty  of  luting 
securely  the  cast-iron  plates  or  fire  tiles  which  cover  the  pan,  the  im,>ossibility  of  com! 

r*«Tl  L  ?K°T''^'''"  ^^^'J^  ^^^'^  ''"'^^  ^he  residuum  mist  be  run  off  in  a  liquid 
.tate,  finally,  the  damage  sustained  by  the  melting  and  corrosion  of  the  lead,  &c ,  are 
lunong  the  causes  why  no  more  than  80  or  90  parts  of  muriatic  acid  at  M70  are  collected 


.V 


MURIATIC  ACID. 


247 


equivalent  to  25  per  cent,  of  real  acid  for  every  lOO  of  salt  employed,  instead  of  muck 
naore  than  double  that  quantity,  which  it  may  be  made  to  yield  by  a  well  conducted 
chemical  process. 

The  cylinder  apparatus  is  now  much  esteemed  by  many  manufacturers.  Jf%a.  98S 
represents,  m  transverse  section,  a  bench  of  iron  cylinder  retorts,  as  built  up  in  a  proper 
furnace  for  producing  muriatic  acid;  and/^.  983,  a  longitudinal  section  of  one  retort 


with  one  of  its  carboys  of  condensation,      a  is  the  grate ;  6,  a  fireplace,  in  which  two 
iron  cylinders,  c  c,  are  set  alongside  of  each  other.      They  are  5|  feet  long,  20  inches  in 

diameter,  about  f  of  an  inch 
thick,  and  take  1-6  cwts.  of 
salt  for  a  charge :  d  is  the  ash- 
pit ;  e,  «,  are  cast-iron  lids,  for 
closing  both  ends  of  the  cylin- 
ders ;  /  is  a  tube  in  the  pos- 
terior lid,  for  pouring  in  the 
sulphuric  acid;  g  is  another 
tube,  in  the  anterior  lid,  for 
the  insertion  of  the  bent  pipe 
of  hard  glazed  stone- ware  A; 
i  is  a  three-necked  stone-ware 
carboy;  fc  is  a  tube  of  safety; 
/,  a  tube  of  communication  witk 
the  second  carboy ;  m  m,mfn, 
are  the  flues  leading  to  the 
A  A        u  chimney  n. 

After  the  salt  has  been  introduced,  and  the  fire  kindled,  83J  per  cent,  of  its 
weight  of  sulphuric  acid,  of  spec.  grav.  1-80,  should  be  slowly  poured  into  the  cyUnder 
through  H  lead  funnel,  with  a  syphon-formed  pipe.  The  three-necked  carboys  may  be 
either  piaced  in  a  series  for  each  retort,  like  a  range  of  Woulfe's  bottles,  or  all  the  carboyt 
of  the  front  range  may  be  placed  in  communication  with  one  another,  while  the  last  car- 
boy at  one  end  is  joined  to  the  first  of  the  second  range ;  and  thus  in  succession.  Thef 
must,  be  half  filled  with  cold  water ;  and  when  convenient,  those  of  the  front  row  at 
least,  should  be  plunged  m  an  oblong  trough  of  running  water.  The  acid  which  con- 
denses m  the  carboys  of  that  row  is  apt  to  be  somewhat  contaminated  with  sulphuric 
acid  muriate  of  iron,  or  even  sulphate  of  soda;  but  that  in  the  second  and  thiid  will  be 
found  to  be  pure.     In  this  way  100  parts  of  sea-salt  will  yield  130  parts  of  muriatic  acid. 

r  T^'  V-'    ^^^l  7^'^''  ^^^  sulphate  of  soda  in  the  retort  wiU  afford  from  208  to  210 
of  that  salt  m  crystals. 

It  is  proper  to  heat  all  the  parts  of  the  cylinders  equably,  to  ensure  the  simultan«>n. 
decomposition  of  the  salt,  and  to  protect  it  from  ihe  acid ;  for  the  hotter  the  iron,  andSJ 
stronger  the  acid,  the  less  erosion  ensues 

nn^fpTZtTJt?'  """''^  ^tj'^.''  ^^  ^^*"?  ^"^*  ^y  the  construction  of  their  furnaces 
oppose  to  the  flame  as  many  obstacles  as  they  can,  and  make  it  perform  numerous  circuS ' 
tions  round  the  cylinders ;  but  this  system  is  bad,  and  does  nbt  even  effect  the  desired 
economy,  because  the  Passage^  being  narrow,  impair  the  draught,  and  become  speedUy 
choked  up  with  the  soot,  which  would  be  burned  profitably  in  I  freer  space;  the  d^n; 
position  also,  b«;;?  unequally  performed,  is  less  perfect,  and  the  cylinders  ire  more  in- 
jured.   It  is  better  to  make  the  flame  envelope  at  once  the  body  of  the  cylinder;  after 


248 


MURIATIC  ACID. 


•■(  I 


jrWch  it  may  circnlate  beneath  the  vault,  in  order  to  gire  out  a  portion  of  its  caloria 
Defore  it  escapes  at  the  chimney.  ^  ^ 

.;.V\l  ^""^  ^^T^^  ^^  ^"'^'^'  kindled  but  lowered  as  soon  as  the  distillation  commences ; 
and  then  continued  moderate  t.  I  the  evolution  of  gas  diminishes,  when  it  must  be 
heated  soinewha  strongly  to  finish  the  decomposition.  The  iron  door  is  now  removed 
to  extract  the  «ulphate  ot  soda,  and  to  recommence  another  operation.  This  sulphate 
ought  to  be  white  and  uniform,  exhibiting  in  its  fracture  no  undecomposed  sea-salt 

J.1.IU1J  muriatic  acid  has  a  very  sour  corrosive  taste,  a  pungent  suffocalin*'  ^mell  and 
acts  very  powerfully  upon  a  vast  number  of  mineral,  Vegetable,  and  an?mal%Xtances 
It  ,s  much  employed  for  making  many  metallic  solutions?  and  in  combinaTon  with  n" trie' 
acid,  11  forms  the  aqua  regia  of  the  alchemists,  so  called  from  its  property  of  dissolving 

Table  of  Muriatic  Acid,  by  Dr.  Ure. 


Acid 
of  l'^( 
in  100 

100 

99 

98 

97 

96 

95 

94 

93 

92 

91 

90 

89 

88 

87 

86 

85 

84 

83 

82 

81 

80 

79 

78 

77 

76 

75 

74 

73 

72 

71 

70 

69 

68 

67 


Specific 
gravity. 


1-2000 

1-1982 

1-1964 

1-1946 

1-1928 

1-J910 

1-1893 

M875 

1-1857 

1-1846 

1-1822 

1-1802 

11782 

1-1762 

1-1741 

M72J 

1-1701 


Chlo- 
rine. 


1681 
1661 
1641 


1 
1 
1 

1-1620 
M599 
M578 
1-1557 
M536 
1-1515 
1-1494 
1-1473 
M4.52 
11431 
M410 
M389 
1-1369 
M349 


39-675 

39-278 

38-882 

38-485 

38-089 

37-692 

37-296 

36-900 

36-503 

36-107 

35-707 

35-310 

34-913 

34-517 

34-121 

33-724 

33-328 

32-931 

32-535 

32- 136 

31-746 

31-343 

30-946 

30-550 

30-153 

29-757 

29-361 

|28-964 

J28-567 

28-171 

,27-772 

;27-376  j 

26-979  i 

126-583 


Muriatic 
Gas. 


40-777 

40-369 

39-961 

39-554 

39-146 

38-738 

38-330 

37-923 

37-516 

37-108 

36-700 

36-292 

35-884 

35-476 

35-068 

34-660 

34-252 

33-845 

33-437 

33-029 

32-621 

32-213 

31-805 

31-398 

30-990 

30-582 

30-174 

29767 

29-359 

|28-951 

28-544 

28-136 

27-728 

27-321 


Acid 
of  120 
in  100 


66 

65 

64 

63 

62 

61 

60 

59 

58 

57 

56 

55 

54 

53 

52 

51 

50 

49 

48 

47 

46 

45 

44 

43 

42 

41 

40 

39 

38 

37 

36 

35 

34 

33 


Specific 
gravity. 


1328 
1308 
1287 
1267 
1247 
1-1226 
1206 
1185 
1164 
1143 
1123 
1102 
1082 
1061 
1041 
1020 
1000 
1-0980 
1-0960 
1-0939 
10919 
1-0899 
1-0879 
1-0859 
1.0838 
1-0818 
1-0798 
1-0778 
1-0758 
1-0738 
10718 
10697 
1-0677 
1-0657 


Chlo- 
rine. 


Muriatic 
Gas. 


26-186 

25-789 

25-392 

24-996 

24-599 

24-202 

23-805 

23-408 

23-012 

22-615 

22-218 

21-822 

21-425 

21-028 

20-632 

20-235 

19-837 

19-440 

19-044 

18-647 

18-250 

17-854 

17-457 

17-060 

16-664 

16267 

15-870 

15-474 

15-077 

14-680 

14-284 

13-887 

13-490 

13-094 


26-913 

26-505 

26-098 

25-690 

25-282 

24-874 

24-466 

24-058 

23-050 

23-242 

22-834 

22-426 

22-019 

21-611 

21-203 

20-796 

20-388 

19-980 

19-572 

19-165 

18-757 

18-349 

17-941 

17-534 

17-126 

16-718 

16-310 

15-902 

15-494 

15-087 

14-679 

14-271 

13-863 

13-456 


Acid  I  c   ., 
n  100  g'a^ity- 


32 

31 

30 

29 

28 

27 

26 

25 

24 

23 

22 

21 

20 

19 

18 

17 

16 

15 

U 

13 

12 

11 

10 

9 

8 

7 

6 

6 

4 

3 

2 

1 


1  0637 

1-0617 

1-0597 

1-0577 

1-0557 

1-0537 

1-0517 

1-0497 

1-0477 

1-0457 

10437 

1-0417 

1-0397 

1-0377 

1-0357 

1-0337 

1-0318 

1-0298 

10279 

1-02.59 

1-0239 

1-0220 

1-0200 

1-0180 

1-0160 

1  0140 

1-0120 

1-0100 

1-0080 

1-0060 

1-0040 

1-0020 


Chlo-    I  Muriatic 
rine.         Gas. 


12-697 

12-300 

11-903 

11-506 

11-109 

10-712 

10-316 

9-919 

9-522 

9-126 

8-729 

8-332 

7-935 

7-538 

7-141 

6-745 

6-348 

5-951 

5-554 

5-158 

4-762 

4-365 

3-968 

3-571 

3-174 

2-778 

2-381 

1  984 

1-588 

1-191 

0-795 

0-397 


13-049 

12-641 

12-233 

11-825 

11-418 

11010 

10-602 

10-194 

9-786 

9-379 

8-971 

8-563 

8-155 

7-747 

7-340 

6-932 

6-524 

6116 

5-709 

5-301 

4-893 

4-486 

4-078 

3-670 

3-262 

2-854  I 

2-447  I 

2-039 

1-631 

1-224 

0-816 

0-408 

i 


In  treating  of  soda,  we  shall  have  occasion  to  comment  upon  the  formation  of  muri. 
atic  acid ;    and  therefore  it  is  unnecessary  to  enter  into  the  details  of  that  operation 
Here.     Ihe  purest  commercial  muriatic  acid  commonly  contains  sulphureous  acid  in 
considerable  quantity,  which  unfits  it  for  many  purposes,  and  ought  therefore  to  bA 
guarded  agamst;  but  more  than  this,  when  made  from  sulphuric  acid  contaiuin^  ar! 
senic,  It  IS  invariably  contaminated  with  that  poisonous  substance,  and  hence  those 
•persons  who  are  in  the  habit  of  making  what  is  called  digestive  bread,  bv  an  Admix- 
ture of  bicarbonate  of  so.la  and  muriatic  acid  with  the  flour  they  employ,  cannot  be  too 
careful  m  going  to  none  but  the  moat  respectable  sources  for  tlieir  acid  •  as  an  enormous 
amount  of  rough  muriatic  acid  is  constantly  passing  through  the  market  positivelv 
loaded  with  arsenious  impurity.     For  the  same  reason,  as  chloride  of  lime  is  manufac- 
tured from  the  acid,  it  must  be  regarded  with  a  cautious  eye;  as,  during  the  action  of 
■uch  muriatic  acid  upon  peroxide  of  manganese,  a  highly  volatUe  chloride  of  arsenic 


# 


.1 


MUSQUET. 


pajsses  off  with  the  chlorine  gas,  and  is  condensed  like  it  by  the  lime.  Since,  however, 
this,  in  the  end,  becomes  arsenite  of  lime,  a  salt  almost  insoluble  in  water,  the  tendency 
to  mischief  is  greatly  diminished.  Nevertheless,  as  in  some  medico-legal  works  it  is 
recommended  to  sprinkle  cadaverous  exhumations  with  chloride  of  linie,  the  ends  of 
justice  may  easily  be  perverted  or  prevented,  if  due  care  be  not  employed  to  ascertain 
beforehand  that  the  chloride  of  lime  is  pure.  Very  little  indeed  of  that  to  be  met  with 
in  commerce  will  bear  a  careful  analytical  investigation. 

MURIATES  were,  till  the  great  chemical  era  of  Sir  II.  Davy's  researches  upon  chlo- 
rine, considered  to  be  compounds  of  an  undecompounded  acid,  the  muriatic,  with  the 
different  bases ;  but  he  proved  them  to  be,  in  reality,  compounds  of  chlorine  with  the 
metals.  They  are  all,  however,  still  known  in  commerce  by  their  former  appellation. 
The  only  muriates  much  used  in  the  manufactures  are,  Muriate  of  ammonia  or  Sal-am- 
moniac; mnriated  peroxide  of  mercury.  Mercury,  bichloride  of;  muriate  of  soda,  or  chlo- 
ride of  sodium,  see  Salt;  muriate  of  tin,  see  Calico-Prixting  and  Tin  ;  Suhmuriate  of 
mercury  or  Calomel. 

MUSK  (J/m«c,  Fr. ;  Moschu^,  Germ.);  is  a  peculiar  aromatic  substance,  found  in  a 
sac  between  the  navel  and  the  parts  of  generation  of  a  small  male  quadruped  of  the 
deer  kind,  called  by  Linnaeus  Moschus  moschifcrus,  which  inhabits  Tonquin  and  Thibet. 
The  color  of  musk  18  blackish-brown;  it  is  lumpy  or  granular,  somewhat  like  dried 
blood,  with  which  substance,  indeed,  it  is  often  adulterated.  The  intensity  of  its  smell 
is  almost  the  only  criterion  of  its  genuineness.  When  thoroughly  dried  it  becomes 
nearly  scentless ;  but  it  recovers  its  odor  when  slightly  moistened  with  water  of  am- 
monia. The  Tonquin  musk  is  most  esteemed.  It  comes  to  us  in  small  bags  covered 
with  a  reddish-brown  hair ;  the  bag  of  the  Thibet  musk  is  covered  with  a  silvery -gray 
hair.  All  the  analyses  of  musk  hitherto  made  teach  little  or  nothing  concerning  its 
active  or  essential  constituent.  It  is  used  in  medicines,  and  is  an  ingredient  in  a  great 
many  perfumes. 

The  musk  deer,  from  the  male  of  which  animal  species  the  bag  containing  this  valu- 
able dru^  is  obtained,  is  a  native  of  the  mountainous  Kirgesian  and  Langorian  steppes  of 
the  Altai,  on  the  river  Irtish,  extending  eastwards  as  far  as  the  river  Jenesi  and  Lake 
Baikal ;  and  generally  of  the  mountains  of  Eastern  Asia,  between  30°  and  60°  of  N.  Lat. 
Two  distinct  kinds  of  musk  are  known  in  commerce,  the  first  being  the  Ciiinese  Ton- 
quin, Thibetian  or  Oriental,  and  the  Siberian  or  Russian.  The  Chinese  is  regarded  by 
l)r.  Goebel  as  the  result  of  ingenious  adulterations  of  the  genuine  article  by  that  crafty 
people.  The  Russian  musk  is  genuine,  the  bags  never  being  opened,  are  consequently 
never  sewn,  nor  artificially  closed,  like  those  imported  into  London  from  China.  The 
former  is  sometimes  so  fresh,  that  moisture  may  be  expressed  from  the  bag  by  cutting 
through  its  fleshy  side.  The  interior  mass  is  frequently  of  a  soft  and  pappy  consist- 
ence ;  but  the  surface  of  the  bag  is  perfectly  dry.  The  Chinese  bags  are  found  invari- 
ably to  have  been  opened  and  again  glued  together,  more  or  less  neatly ;  though 
sometimes  the  stitches  of  the  sewing  are  munifest,  Mr.  Diyssen,  an  eminent  merchant 
at  St  Petersburgh,  states  that  during  the  many  years  he  has  been  in  the  trade,  al- 
though he  has  received  at  a  time  from  100  to  200  ounces  from  London,  yet  in  no  case 
whatever  has  he  met  with  a  bag  which  had  not  been  opened,  and  closed  with  more  or 
less  ingenuity.  The  genuine  contents  seem  to  have  been  first  removed,  modified,  and 
replaced-  M.  Guibourt  gives  the  following  as  the  constituents  of  a  Chinese  musk  bag: 
1,  water;  '2,  ammonia;  3,  solid  fat  or  stearine;  4,  liquid  fat  or  elaine;  5,  cholesterine ; 
6,  acid  oil,  combined  with  ammonia;  7,  volatile  oil;  8-10,  hydrochlorates  of  ammonia,' 
potassa,  and  lime;  11,  an  undetermined  acid;  12,  gelatine;  13,  albumen;  14,  fibrine; 
15,  carbonaceous  matter,  soluble  in  water;  16,  calcareous  salt;  17,  carbonate  of  lime* 
18,  hairs  and  sand.  * 

From  June  1841  to  June  1842,  a  duty  of  &d.  per  oz.  was  paid  at  the  port  of  London 
alone  upon  969  ounces  of  musk.  The  prices  of  grain  musk  of  the  best  quality  (the 
matter  without  the  bag)  varies  from  60».  to  95«.  per  oz. 

There  is  a  superior  musk  imported  now  from  the  United  States,  which  is  nearly  free 
from  the  carbonate  of  lime,  so  abundant  in  the  bags  of  the  Siberian  musk. 

MUSLIN,  is  a  fine  cotton  fabric,  used  for  ladies'  robes;  which  is  worn  either  white 
dyed,  or  printed.  * 

MUSQUET.  It  is  now  twenty-two  years  since  the  Hon.  Board  of  Ordnance,  with 
the  view  of  introducing  the  use  of  percussion  fire-arms  into  the  British  Army  em-, 
ployed  nie  to  investigate  experimentally  the  best  njode  of  preparing  the  priming  powder 
for  that  purpose.  The  result  of  these  experiments  was  presented  in  a  report  the  sub- 
stance of  which  IS  given  under  the  article  Fulminate  in  this  Dictionar}-.  During 
this  long  interval,  Mr.  Lovell,  inspector  of  small  arms  for  her  Majesty's  service,  and 
director  of  the  Royal  manufactory,  at  Enfield  Chase,  has  directed  his  ingenious  mind 
to  the  construction  of  a  sure,  simple,  and  strong  musquet,  with  whicli,  under  his  able 
•uperintendence,  the  whole  of  her  Majesty's  soldiers  are  now  provided.  He  had  also 
Vou  IL 


250 


MUSQUET. 


fiiruished  them  with  a  shorty  but  clear  set  of  instructions  for  the  cleaning  and  man- 
^ement  of  these  excellent  arms,  illustrated  by  a  series  of  wood  engravings.  Fr^  m  thii 
little  work,  the  following  notice  is  copied. 

Fig.  984.  The  barrel,  reduced  to  one-seventh  size,  a,  the  breech ;  h,  the  nipple-seat 
or  lump;  c,  the  back-sight;  d,  the  back  loop;  e,  the  middle  loop;  /,  the  swivel-loop; 
g^  the  front-loop  with  the  bayonet  spring  attached;  h,  the  front  sight;  t,  the  muzzle. 

Fig.  985.  The  breech-pin,  half  size ;  a,  the  tang ;  b,  the  neck ;  c,  the  screw  threads  : 
a,  the  face. 


984J 


988 


^^^ 


I*' 


Fig.  986.    The  bayonet-spring,  two  ways,  half  size,    o,  the  shank:  h,  the  neck;  e; 
the  hook ;  rf,  the  mortice. 

ftg.OSt    The  nipple,  full  size,    a,  the  cone;  6,  the  squares  t  c,  the  shoulder;  a. 
Che  screw-threads  j  «,  the  touch-hole. 


MYRICINE. 

Fig.  988.     The  rammer,  reduced  to  one-seventh  size,     a,  the  head ;  6,  the  shaft ;  c^ 
the  screw-threads. 

Fig.  989.     The  lock  outside,  half  size,     a,  the  plate;  6,  the  cock;  c;  the  tumbler-pin ; 
dy  the  hollow  for  the  nipple  seat 


Fig.  990.    The  lock  inside,  half  size,  showing  all  the  parts  in  their  places  with  the  cock 
down  at  bearer,     c,  the  main-spring j  b,  the  sear-spring;  c,  the  sear;  d,  the  tumbler; 


the 


e,  the   bridle;  /,  the   main-spring;   g,  the  sear-pin;   h,  the   sear-spring-pin;   t. 
bridle -pin.  o  «-     »     » 

MUST  is  the  sweet  juice  of  the  grape. 

MUSTARD  (Moutarde,  Ft.  ;  Sen/,  Germ.)  is  a  plant  which  yields  the  well-known 
seed  used  as  a  condiment  to  food.  M.  Lenormand  gives  the  following  prescription  for 
preparing  mustard  for  the  table. 

With  2  |H)unds  of  very  fine  flour  of  mustard,  mix  half  an  ounce  of  each  of  the  follow- 
ing fresh  plants ;  parsley,  chervil,  celerj',  and  tarragon,  along  with  a  clove  of  garlic,  and 
twelve  salt  anchovies,  all  well  minced.  The  whole  is  to  be  triturated  with  the  flour  of 
mustard  till  the  mixture  becomes  uniform.  A  little  grape-must  or  suffar  is  to  be  added, 
to  give  the  requisite  sweetness;  then  one  ounce  of  salt,  with  sufficient  water  to  form  a 
thinnish  paste  by  rubbing  in  a  mortar.  With  this  paste  the  mustard  pots  being  nearly 
filled,  a  redhot  poker  is  to  be  thrust  down  into  the  contents  of  each,  which  rem^oves  (it 
is  said)  some  of  the  acrimony  of  the  mustard,  and  evaporates  a  little  water,  so  as  to  make 
room  for  pouring  a  little  vinegar  upon  the  surface  of  the  paste.  Such  table  mustard  not 
only  keeps  perfectly  well,  but  improves  with  age. 

The  mode  of  preparing  table  mustard  patented  by  M.  Soyes,  consisted  in  steeping 
mustard  seed  m  twice  its  bulk  of  weak  wood  vinegar  for  eight  days,  then  grinding  the 
whole  into  paste  m  a  mill,  putting  it  into  pots,  and  thrusting  a  redhot  poker' into 
each  of  them. 

MUTAGE  is  a  process  used  in  the  south  of  France  to  arrest  the  progress  of  fermenta- 
tion in  the  must  of  the  grape.  It  consists  either  in  diffusing  sulphurous  acid,  from  burn- 
ing sulphur  matches  m  the  cask  containing  the  must,  or  in  adding  a  little  sulphite  (not 
sulphate)  of  lirne  to  it.     The  last  is  the  best  process.     See  Fermentation. 

MYRICINE  is  a  vegetable  principle  which  constitutes  from  20  to  20  per  cent,  of 
the  weight  of  bees-wax,  being  the  residuum  from  the  solvent  action  of  alcohol  upon  lb»l 


252 


NAILS. 


4 


: 


substance.    It  is  a  grayish-white  solid,  which  may  be  vaporized  almost  without  alter- 
ation. 

MYRRH  is  a  gum-resin,  which  occurs  in  tears  of  different  sizes;  they  are  reddish- 
brown,  semi-transparent,  brittle,  of  a  shining  fracture,  appear  as  if  greasy  under  the 
peslle,  they  have  a  very  acrid  and  bitter  taste,  and  a  strong,  not  disagreeable,  smell. 
Myrrh  flows  from  the  incisions  of  a  tree  not  well  known,  which  grows  in  Arabia  and 
Abyssinia,  supposed  to  be  a  species  of  amyria  or  mimosa.  It  consists  of  resin  and  gum  in 
proportions  stated  by  Pelletier  at  3 1  of  the  former  and  66  of  the  latter  j  but  by  Braconot, 
at  23  and  77.    It  is  used  only  in  medicine. 


N. 

NACARAT  is  a  term  derived  from  the  Spanish  word  nacar,  which  signifies  mothei  of 
pearl ;  and  is  applied  to  a  pale  red  color,  with  an  orange  cast.  See  Calico-printing. 
The  nacarat  of  Portugal  or  Bezetta  is  a  crape  or  fine  linen  fabric,  dyed  fugitively  of  the 
above  tint,  which  ladies  rub  upon  their  countenances  to  give  them  a  roseate  hue.  The 
Turks  of  Constantinople  manufacture  the  brightest  red  crapes  of  this  kind.     See  Rouge. 

NAILS,  MANUFACTURE  OF.    (C/ou,  Fr. ;  Nagel,  Germ.) 

The  forging  of  nails  was  till  of  late  years  a  handicrail  operation,  and  therefore  belonged 
to  a  book  of  trades,  rather  than  to  a  dictionary  of  arts.  But  several  combinations  of 
machinery  have  been  recently  employed,  under  the  protection  of  patents,  for  making  these 
Vseful  implements,  with  little  or  no  aid  of  the  human  hand ;  and  these  deserve  to  be 
noticed,  on  account  both  of  their  ingenuity  and  importance. 

As  nails  are  objects  of  prodigious  consumption  in  building  their  block-houses,  the 
citizens  of  the  United  States  very  early  turned  their  mechanical  genius  to  good  account  in 
the  construction  of  various  machines  for  makins  them.  So  long  since  as  the  year  1810,  it 
appears,  from  the  report  of  the  secretary  of  their  treasury,  that  they  possessed  a  machine 
which  performed  the  cutting  and  heading  at  one  operation,  with  such  rapidity  that  it 
could  turn  out  upwards  of  100  nails  per  minute.  «  Twenty  years  ago,"  says  the  secretary 
of  the  state  of  Massachusetts,  in  that  report,  "  some  men,  then  unknown,  and  then  in 
obscurity,  began  by  cutting  slices  out  of  old  hoops,  and,  by  a  common  vice  griping  these 
pieces,  headed  them  with  several  strokes  of  the  hammer.  By  progressive  improvements, 
slitting-mills  were  built,  and  the  shears  and  the  heading  tools  were  perfected  ;  yet  much 
labor  and  expense  were  requisite  to  make  nails.  In  a  little  time  Jacob  Perkins,  Jona- 
than Ellis,  and  a  few  others,  put  into  execution  the  thought  of  cutting  and  of  heading  nails 
by  water  power ;  but,  being  more  intent  upon  their  machinery  than  upon  their  pecuniary 
affairs,  they  were  unable  to  prosecute  the  business.  At  different  times  other  men  have 
spent  fortunes  in  improvements  and  it  may  be  said  with  truth  that  more  than  one  mil- 
lion of  dollars  has  been  expended  ;  but  at  length  these  joint  efforts  are  crowned  with  com- 
plete success,  and  we  are  now  able  to  manufacture,  at  about  one  third  of  the  expense 
that  wrought  nails  can  be  manufactured  for,  nails  which  are  superior  to  them  for  at  least 
three  fourths  of  the  purposes  to  which  nails  are  applied,  and  for  most  of  those  purposes 
they  are  full  as  good.  The  machines  made  use  of  by  Odiorne,  those  invented  by  Jonathan 
Ellis,  and  a  few  others,  present  very  fine  specimens  of  American  genius. 

«  To  northern  carpenters,  it  is  well  known  that  in  almost  all  instances  it  is  unneces- 
sary tc  bore  a  hole  before  driving  a  cut  nail ;  all  that  is  requisite  is,  to  place  the  cutting 
edge  of  the  nail  across  the  grain  of  the  wood ;  it  is  also  true,  that  cut  nails  will  hold  bet- 
ter in  the  wood.  These  qualities  are,  in  some  rough  building  works,  worth  twenty  per 
cent,  of  the  value  of  the  article,  which  is  equal  to  the  whole  expense  of  manufacturing. 
For  sheathing  and  drawing,  cut  nails  are  full  as  good  as  wrought  nails ;  only  in  one 
respect  are  the  best  wrought  nails  a  little  superior  to  cut  nails,  and  that  is  where  it  is  ne- 
cessary they  should  be  clinched.  The  manufacture  of  cut  nails  was  born  in  our  country, 
and  has  advanced,  within  its  bosom,  through  all  the  various  stages  of  infancy  to  manhood; 
and  no  doubt  we  shall  soon  be  able,  by  receiving  proper  encouragement,  to  render  them 
superior  to  wrought  nails  in  every  particular. 

"  The  principal  business  of  rolling  and  slitting-mills,  is  rolling  nail  plates ;  they  also 
serve  to  make  nail  rods,  hoops,  tires,  sheet  iron,  and  sheet  copper.  In  this  State  we 
have  not  less  than  twelve. 

«  These  mills  could  roll  and  slit  7000  tons  of  iron  a  year ;  they  now,  it  is  presumed, 
roil  and  slit  each  year  about  3500  tons,  2400  tons  of  which,  probably,  are  cut  up  into 
nails  and  brads,  of  such  a  quality  that  they  are  good  substitutes  for  hammered  nails,  and, 
in  fact,  have  the  preference  with  most  people,  for  the  following  reasons ;  viz.,  on  account 
of  the  sharp  corner  and  true  taper  with  which  cut  nails  are  formed  ;  they  may  be  driven 
into  harder  wood  without  bending  or  breaking,  or  hazard  of  splitting  the  wood,  by  which 


NAILS. 


258 


the  labor  of  boring  is  saved,  the  nail  one  way  being  of  the  same  breadth  or  thickness  from 
head  to  point.'* 

Since  the  year  1820,  the  following  patents  have  been  obtained  in  England  for  making 
nails  ;  many  of  them  of  American  origin  : — 

Alexander  Law,  September,  1821,  for  nails  and  bolts  for  ships'  fastenings,  made  in  a 
twisted  form,  by  hand  labor. 

Glascott  and  Mitchell,  December,  1823,  for  ship  nails  with  rounded  heads,  by  hand 
labor. 

Wilks  and  Ecroyd,  November,  1825,  for  an  engine  for  cutting  wedge-form  pieces  from 
plates. 

Ledsom  and  Jones,  December  II,  1827,  for  machinery  for  cutting  brads  and  sprigs  from 
plates ;  it  does  not  form  heads. 

The  first  nail  apparatus  to  which  I  shall  particularly  advert,  is  due  to  Dr.  Church  ;  it 
was  patented  in  his  absence  by  his  correspondent,  Mr.  Thomas  Tvndall,  of  Birmingham 
in  December,  1827.  It  consists  of  two  parts;  the  first  is  a  mode  of  forming  nails,  and 
the  shafts  of  screws,  by  pinching  or  pressing  ignited  rods  of  iron  between  indented  rol- 
lers ;  the  second  produces  the  threads  on  the  shafts  of  the  screws  previously  pressed. 
The  metallic  rods,  by  being  passed  between  a  pair  of  rollers,  are  rudely  shaped,  and  then 
cut  asunder  between  a  pair  of  shears  ;  after  which  they  are  pointed  and  headed,  or  other- 
wise brought  to  their  finished  forms,  by  the  agency  of  dies  placed  in  a  revolving  cylinder. 
The  several  parts  of  the  mechanism  are  worked  by  toothed  wheels,  cams,  and '  levers* 
The  second  part  of  Dr.  Church's  invention  consists  of  a  mechanism  for  cutting  the  threads 
of  screws  to  any  degree  of  obliquity  or  fonn.* 

Mr.  L.  W.  Wright's  (American)  apparatus  should  have  been  mentioned  before  the  pre- 
ceding, as  the  patent  for  it  was  sealed  in  March  of  the  same  year ;  though  an  amended 
patent  was  obtained  in  September,  1828.  Its  object  was  to  form  metal  screws  for  wood. 
I  have  seen  the  machinery,  but  consider  it  much  too  complex  to  be  described  in  the 
present  work. 

Mr.  Edward  Hancorne,  of  Skinner  street,  London,  nail  manufacturer,  obtained  a 
patent  in  October,  1828,  for  a  nail  making-machine,  of  which  a  brief  description  may 
give  my  readers  a  conception  of  this  kind  of  manufacture.  Its  principles  are  simiUir  to 
those  of  Dr.  Church's  more  eleborate  apparatus. 

The  rods  or  bars  having  been  prepared  in  the  usual  way,  either  by  rolling  or  hammer- 
ing, or  by  cutting  from  sheets  or  plates  of  iron,  called  slitting,  are  then  to  be  made  red- 
hot,  and  in  that  state  passed  through  the  following  machine,  whereby  they  are  at  once  cut 
into  suitable  lengths,  pressed  into  wedge  forms  for  pointing  at  the  one  end,  and  stami>ed 
at  the  other  end  to  produce  the  head.  A  longitudinal  view  of  the  machine  is  shown  in 
tig.  991.  A  strong  iron  frame-work,  of  which  one  side  is  shown  at  a  a,  supports  the 
whole  of  the  mechanism.    6  is  a  table  capable  of  sliding  to  and  fro  horizontally. 


Upon  this  table  are  the  clamps,  which  lay  hold  of  the  sides  X)f  the  rod  as  it  advances- 
as  also  the  shears  which  cut  the  rod  into  nail  lengths  auvances, 

These  clamps  or  holders  consist  of  a  fixed  piece  and  a  movable  piece  •  the  latter  be- 
in^  brought  into  action  by  a  lever.  The  rod  o."bar  of  iron  shown  at  I  having  been  madt 
rel  hot.  IS  introduced  into  he  machine  by  sliding  it  forward  upon  the  tabled  whenthe 
table  IS  m  its  most  advanced  position ;  rotatory  motion  is  then  given  to  the  crank  shaft^ 

♦  For  further  details,  see  Newton's  Journal,  2nd  series,  vol  liL  p.  184 


S5i 


NAILS. 


by  means  of  a  band  passing  round  the  rigger  pulley  «,  which  causes  the  table  6  to  be 
drawn  back  by  the  crank  rod  /;  and  as  the  table  recedes,  the  horizontal  lever  is  acted 
upon,  which  closes  the  clamps.  By  these  means  the  clamps  take  fast  hold  of  the  sides  of 
the  heated  rod,  and  draw  it  forward,  when  the  moveable  chap  of  the  shears,  also  acted 
upon  by  a  lever,  slides  laterally,  and  cuts  off  the  end  of  the  rod  held  by  the  clamps :  the 
piece  thus  separated  is  destined  to  form  one  nail. 

Suppose  that  the  nail  placed  at  g,  having  been  thus  brought  into  ihe  machine  and  cut 
off,  is  held  between  clamps,  which  press  it  sideways  (these  clamps  are  not  visible  in  this 
view) ;  in  this  state  it  is  ready  to  be  headed  and  pointed. 

The  header  is  a  steel  die  /»,  which  is  to  be  pressed  up  against  the  end  of  the  nail  by  a 
cam  t,  upon  the  crank-shafl ;  which  cam,  at  this  period  of  the  operation,  acts  against  the 
end  of  a  rod  fr,  forming  a  continuation  of  the  die  A,  and  forces  up  the  die,  thus  compress- 
ing the  metal  into  the  shape  of  a  nail-head. 

The  pointing  is  performed  by  two  rolling  snail  pieces  or  spirals  /,  /.  These  pieces  arc 
somewhat  broader  than  the  breadth  of  the  nail ;  they  turn  upon  axles  in  the  side  frames. 
As  the  table  b  advances,  the  racks  wi,  on  the  edge  of  this  table,  take  mto  the  toothed 
segments  «,  «,  upon  the  axles  of  the  spirals,  and  cause  them  to  turn  round. 

These  spirals  pinch  the  nail  at  first  close  under  its  head  with  very  little  force  ;  but  as 
they  turn  round,  the  longer  radius  of  the  spiral  comes  into  operation  upon  the  nail,  so  as 
to  press  its  substance  verv  strongly,  and  squeeze  it  into  a  wedge  form.  Thus  the  nail 
is  completed,  and  is  immediately  discharged  from  the  clamps  or  holders.  The  carriage  is 
then  again  put  in  motion  by  the  rotation  of  the  crank-shafY,  which  brings  another  portion 
of  the  rod  c  forward,  cuts  it  off,  and  then  forms  it  into  a  nail. 

Richard  Prossery  July,  1831,  for  makins:  tacks  for  ornameatal  furniture,  by  soldering  or 
wedging  the  spike  into  the  head.    This  also  is  the  invention  of  Dr.  Church. 

Dr.  William  Church,  Februan',  1^32,  for  improvements  in  machinery  for  making 
nails.  These  consist,  first,  in  apparatus  for  forming  rods,  bars,  or  plates  of  iron,  or  other 
metals;  secondly,  in  apparatus  for  converting  the  rods,  &c.,  into  nails;  thirdly,  in  im- 
provements upon  Prosser's  patent.      The  machinery  consists  in  laminating  rollers,  and 

compressinar  dies.  .  ,     •  i       . 

The  method  of  forming  the  rods  from  which  the  nails  are  to  be  made,  is  very  advanto- 
geous.  It  consists  in  passing  the  bar  or  plate  iron  through  pressing  rollers,  which  have 
indentations  upon  the  peripheries  of  one  or  both  of  them,  so  as  to  form  the  bar  or  plate 
into  the  required  shape  for  the  rods,  which  may  be  afXerwards  separated  into  rods  of  any 
desired  breadth,  bv  common  slittine  rollers. 

The  principal  object  of  rolling  the  rods  into  these  wedge  forms,  is  to  measure  out  a 
quantity  of  metal  duly  proportioned  to  the  requir^'d  thickness  or  strength  of  the  nail  m  its 
several  parts ;  which  quantity  corresponds  to  the  indentations  of  the  rollers. 

Thomas  John  F^'ller,  February  27,  J  834,  for  an  improved  apparatus  for  making  square- 
pointed  and  also  flat-pointed  nails.  He  claims  as  his  invention,  the  application  of  ver- 
tical  and  horizontal  hammers  (mounted  in  his  machine)  combined  for  the  i)urpo8e  of 
tapeiing  and  forming  the  points  of  the  nails ;  which,  being  made  to  act  alternately,  re- 
semble hand  work,  and  are  therefore  not  so  apt  to  injure  the  fibrous  texture  of  the  iron, 
he  imagines,  as  the  rolling  machinery  is.     He  finishes  the  points  by  rollers. 

Miles  Berry y  February  19,  1834,  for  machinery  for  forming  metal  into  bolts,  rivets, 
nails,  and  other  articles  ;  beinsr  a  communication  from  a  foreigner  residing  abroad.  He 
employs  in  his  machine  holding  chaps,  heading  dies,  toggle  joints,  cams,  &c.,  mechan. 
isms  apparently  skilfully  contrived,  but  too  complex  for  admission  under  the  article  naU 

in  this  volume.  ^ .    .  ,  •  .i      r  a        • 

William  Southwood  Stacker,  Julv,  1836.  This  is  a  machine  apparently  of  American 
parentage,  as  it  has  the  same  set  of  features  as  the  old  American  mechanisms  of  Perkins 
and  Dyer,  at  the  Britannia  Nail-works,  Birmingham,  and  all  the  other  American  machines 
since  described,  for  pressing  metal  into  the  forms  of  nails,  pins,  screw-shaf\s,  rivets,  &c. ; 
for  example,  it  possesses  pressers  or  hammers  for  squeezing  the  rods  of  metal,  and  form- 
in*'  the  shanks,  which  are  all  worked  by  a  rotatory  action ;  cutters  for  separating  the  ap- 
propriate lengths,  and  dies  for  forming  the  heads  by  compression,  also  actuated  by  revolv- 

ing  cams  or  cranks.  *.  .         . 

Mr.  Stocker  intends,  in  fact,  to  effect  the  sar..e  sorts  of  operations  by  automatic  me- 
chanisms as  are  usually  performed  by  the  hands  of  a  nail-maker  with  his  hammer  and  anvil ; 
viz.,  the  shaping  of  a  nail  from  a  heated  rod  of  iron,  cutting  it  oflfat  the  proper  length,  and 
then  compressing  the  end  of  the  metal  into  the  form  of  the  head.  His  machine  may  be 
said  to  consist  of  two  parts,  connected  in  the  same  frame ;  the  one  for  shaping  the  shank 
of  the  nail,  the  other  for  cutting  it  off  and  heading  it.  The  frame  consists  of  a  strong 
table  to  bear  the  machinery.  Two  pairs  of  hammers,  formed  as  levers,  the  one  pair 
made  to  approach  each  other  by  horizontal  movements,  the  other  pair  by  vertical  move- 
ments are  the  implements  by  which  a  portion  at  the  end  of  a  redhot  rod  of  iron  is 
beaten  or  pressed  into  the  wedge-like  shape  of  the  shaft  of  a  nail.    This  having  been 


NANKIN. 


S6ff 


done,  and  the  rod  being  still  hot,  is  withdrawn  from  the  beaters,  and  placed  in  the  other 
part  of  the  machine,  consisting  of  a  p*ir  of  jaws  like  those  of  a  vice,  which  pinch  the 
shank  of  the  nail  and  hold  it  fast.  A  cutter  upon  the  side  of  a  wheel  now  comes  round, 
and,  bv  acting  as  the  moving  chap  of  a  pair  of  shears,  cuts  the  nail  oflT  from  the  rod. 
The  nail  shank  being  stUl  firmly  held  in  the  jaws  of  the  vice,  with  a  portion  of  its  end 
projecting  outwardly,  the  heading  die  is  slidden  laterally  until  it  comes  opposite  to  the 
end  of  the  nail ;  the  die  is  then  projected  forward  with  great  force,  for  the  purpose  of 
what  is  termed  upsetting  the  metal  at  the  projecting  end  of  the  nail,  and  thereby  blocking 
out  the  head. 

A  main  shaft,  driven  by  a  band  and  rigger  as  usual,  brings,  as  it  revolves,  a  cam  into 
operation  upon  a  lever  which  carries  a  double  inclined  plane  or  wedge  in  its  front  or  acting 
part.  This  wedge  being  by  the  rotatory  cam  projected  forwards  between  the  tails  of 
one  of  the  pairs  of  hammers,  causes  the  faces  of  these  hammers  to  approach  each  oth«r, 
and  to  beat  or  press  the  redhot  iron  introduced  between  them,  so  as  to  flatten  it  upon 
two  opposite  sides.  The  rotatory  cam  passing  round,  the  wedge  lever  is  relieved,  when 
springs  instantly  throw  back  the  hammers ;  another  cam  and  wedge-lever  now  brings 
the  second  pair  of  hammers  to  act  upon  the  other  two  sides  of  the  nail  in  a  similar  way. 
This  is  repeated  several  times,  until  the  end  of  the  redhot  iron  rod,  gradually  advanced  by 
the  hands  of  the  workman,  has  assumed  the  desired  form,  that  is,  has  received  the  bevd 
and  point  of  the  intended  nail. 

The  rod  is  then  withdrawn  from  between  the  hammers,  and  m  its  heated  state  is  16- 
troduced  between  the  jaws  of  the  holders,  for  cutting  oflf  and  finishing  the  nail.  A  bevel 
pinion  upon  the  end  of  the  main  shafl,  takes  into  and  drives  a  wheel  upon  a  transverse 
shafl,  which  carries  a  cam  that  works  the  lever  of  the  holding  jaws.  The  end  of  the 
rod  being  so  held  in  the  jaws  or  vice,  a  cutter  at  the  side  of  a  wheel  upon  the  transverse 
shaft  seplirates,  as  it  revolves,  the  nail  from  the  end  of  the  rod,  leaving  the  nail  firmly 
held  by  the  jaws.  By  means  of  a  cam,  the  heading  die  is  now  slidden  laterally  opposite 
to  the  end  of  the  nail  in  the  holding  jaws,  and  by  another  cam,  upon  the  main  shaft,  the  die 
is  forced  forward,  which  compresses  the  end  of  the  nail,  and  spreads  out  the  nail  into  the 
form  of  a  head.  As  the  main  shafl  continues  to  revolve,  the  cams  pass  away,  and  allow 
the  spring  to  throw  the  jaws  of  the  vice  open,  when  the  nails  fall  out;  but  to  guard 
against  the  chance  of  a  nail  sticking  in  the  jaws,  a  picker  is  provided,  which  pushes  the 
nail  out  as  soon  as  it  is  finished. 

In  order  to  produce  round  shafts,  as  for  screw  blanks,  bolts,  or  rivets,  the  faces  of  the 
hammers,  and  the  dies  for  heading,  must  be  made  with  suitable  concavities. 

NAILS.  {Exhibition.)  John  Reynolds,  Crown  Nail  Works,  Newton  Row,  Birming- 
ham, Manufacturer.  _    ^  .     . 

A  case  enclosing  a  card  of  cut  nails,  consisting  of  upwards  of  200  distinct  varieties 
of  the  most  useful  strengths  and  sizes,  made  of  iron,  zinc,  brass,  and  copper. 

In  this  manufacture  sheets  of  iron  of  the  proper  thickness  are  cut  across  by  a  pair 
of  cutting  edges,  which  are  set  in  motion  by  machinery ;  the  breadth  of  these  strips  is 
equivalent  to  the  length  of  the  nails  to  be  produced  from  them ;  the  strip,  for  the  conve- 
nience of  turning,  is  fastened  into  apairof  grips  attached  to  a  wood  shank,  resting  when 
in  use  upon  a  support  immediately  behind  the  workman.  The  nail  machine  consists 
essentially  of  a  pair  of  cutting  chisels  or  edge?,  which  work  perpendicularly,  parallel 
to  each  otlier ;  a  gauge,  to  determine  the  breadth  of  a  nail ;  a  pair  of  grips,  into  which 
at  the  time  the  wedge  of  iron  fails,  and  where  it  is  firmly  held  until  the  small  horizontal 
hammer  strikes  it  and  produces  the  head,  when  it  is  dropped  into  a  box  beneath.  Brads 
are  not  headed,  but  are  simply  cut  out  of  each  other ;  that  is  to  say,  a  deficiency  in  the 

Earallelism  of  the  cutting  edge  produces  the  head  and  prepares  for  the  head  of  the  next 
rad  to  be  cut  therefrom.  Glaziers'  brads  being  simple  wedge-like  pieces  of  iron,  with- 
out any  head  whatever,  are  produced  by  the  simple  operations  of  the  chisels  or  cutters. 
When  tucks  are  blued  they  are  done  in  quantities  by  exposing  them  to  heat  in  an 
oven  or  muffle,  or  upon  an  iron  plate.  Japanning  is  performed  by  the  ordinary  process. 
NANKIN,  is  a  peculiarly  colored  cot'.on  clotli,  originally  manufactured  in  the  above 
named  ancient  capital  of  China,  from  a  native  cotton  of  a  brown  yellow  hue.  Nan 
kin  cloth  has  been  long  imitated  in  perfection  by  our  own  manufacturers;  and  is  now 
exported  in  considerable  quantities  from  England  to  Canton.  The  following  is  the 
process  for  dyeing  calico  a  nankin  color.  ' 

1.  Take  300  pounds  of  cotton  yarn  in  hanks,  being  the  qnantity  which  four  workmen 
can  dye  in  a  day.  The  yarn  for  the  warp  may  be  about  No.  27'8,  and  that  for  the  weft 
23'8  or  24r's. 

2.  For  alwixing  that  quantity,  take  10  pounds  of  saturated  alum,  free  from  iron  (see 
Mordant);  divide  this  into  two  portions;  dissolve  the  first  by  itself  in  hot  water,  so 
as  to  form  a  solution,  of  spec.  grav.  1°  Baume^.  The  second  portion  is  to  be  reserved 
for  the  galling  bath. 

8.  Galling,  is  given  with  about  80  pounds  of  oak  bark  finely  ground-  This  bark 
may  serve  for  two  quantities,  if  it  be  applied  a  little  longer  the  second  time. 


266 


NAPHTHA. 


4.  Take  30  pounds  of  fresh  slaked  quicklime,  and  form  with  it  a  large  bath  of  lime- 
water. 

5.  Nitro-muriate  of  tin.  For  the  last  bath,  10  or  12  pounds  of  solution  of  tin  are  used, 
which  is  prepared  as  follows : 

Take  10  pounds  of  strong  nitric  acid,  and  dilute  with  pure  water  till  its  specific  gravity 
be  26°  B.  Dissolve  in  it  4633  grains  ( 10|  oz.  avoird.)  of  sal  ammoniac,  and  3  oz.  of  nitre. 
Into  this  solvent,  contained  in  a  bottle  set  in  cold  water,  introduce  successively,  in  very 
small  portions,  28  ounces  of  grain-tin  granulated.  This  solution,  when  made,  must  be 
kept  in  a  well  stoppered  bottle. 

Three  coppers  are  required,  one  round,  about  five  feet  in  diameter,  and  32  inches  deep, 
for  scouring  the  cotton ;  2.  two  rectangular  coppers  tinned  inside,  each  5  feet  long  and  20 
inches  deep.  Two  boxes  or  cisterns  of  while  wood  are  to  be  provided,  the  one  for  the 
lime-water  balh,  and  the  other  for  the  solution  of  tin,  each  about  7  feet  long,  32  inches 
wide,  and  14  inches  deep ;  they  are  set  upon  a  platform  28  inches  high.  In  the  middle 
between  these  two  chests,  a  plank  is  fixed,  mounted  with  twenty-two  pegs  for  wringing 
Ihe  hanks  upon,  as  they  are  taken  out  of  the  bath. 

6.  Muming.  After  the  cotton  yarn  has  been  scoured  with  water,  in  the  round  copper, 
oy  being  boiled  in  successive  portions  of  100  pounds,  it  must  be  winced  in  one  of  the 
square  tinned  coppers,  containing  two  pounds  of  alum  dissolved  in  96  gallons  of  water, 
at  a  temperature  of  165°  F.  It  is  to  be  then  drained  over  the  copper,  exposed  for  some 
time  upon  the  grass,  rinsed  in  clear  water,  and  wrung. 

7.  The  galling.  Having  filled  four-fifths  of  the  second  square  copper  with  water,  40 
pounds  of  ground  oak  bark  are  to  be  introduced,  tied  up  in  a  bag  of  open  canvass,  and 
boiled  for  two  hours.  The  bag  being  withdrawn,  the  cotton  yarn  is  to  be  winced  through 
the  boiling  tan  bath  for  a  quarter  of  an  hour.  While  the  yarn  is  set  to  drain  above  the 
bath,  28  ounces  of  alum  are  to  be  dissolved  in  it,  and  the  yarn  being  once  more  winced 
through  it  for  a  quarter  of  an  hour,  is  then  taken  out,  drained,  wrung,  and  exposed  to  the 
air.  It  has  now  acquired  a  deep  but  rather  dull  yellowish  color,  and  is  ready  without 
washing  for  the  next  process.     Bablah  may  be  substituted  for  oak  bark  with  advantage. 

8.  The  liming.  Into  the  cistern  filled  with  fresh  made  lime-water,  the  hanks  of  cotton 
yarn,  suspended  upon  a  series  of  wooden  rods,  are  to  be  dipped  freely  three  times  in  rapid 
succession  ;  then  each  hank  is  to  be  separately  moved  by  hand  through  the  lime  bath,  till 
the  desired  carmelite  shade  appear.     A  weak  soda  ley  may  be  used  instead  of  lime  water. 

9.  The  brightening  is  given  by  passing  the  above  hanks,  after  squeezing,  rinsing,  and 
airing  them,  through  a  dilute  bath  of  solution  of  tin.  The  color  thus  produced  is  said 
to  resemble  perfectly  the  nankin  of  China. 

Another  kind  of  nankin  color  is  given  by  oxyde  of  iron,  precipitated  upon  the  fibre 
of  the  cloth,  from  a  solution  of  the  sulphate,  by  a  solution  of  soda.    See  Calico- 

NAPHTHA,  or  ROCK-OIL  {Huile  petrole,  Fr. ;  Sieindl,  Germ.) ;  the  Seneca  oil  of 
Korth  America,  is  an  ethereous  or  volatile  oil,  which  is  generated  within  the  crust  of 
the  earth,  and  issues  in  many  different  localities.  The  colorless  kind,  called  naphtha, 
occurs  at  Baku,  near  the  Caspian  Sea,  where  the  vapors  which  it  exhales  are  kindled, 
and  the  flame  is  applied  to  domestic  and  other  economical  purposes.  Wells  are  alsp 
dug  in  that  neighborhood,  in  which  the  naphtha  is  collected.  Similar  petroleum  wel» 
exist  in  the  territory  of  the  Birmans,  at  Yananghoung,  upon  the  river  Irawaddy,  80 
hours' journey  north-east  of  Pegu,  where  no  less  than  220  such  springs  issue  from  a 
pale  blue  clay,  soaked  with  oil,  which  rests  upon  roofing  slate.  Under  the  slate  is  coal 
containing  much  pyrites.  Each  spring  yields  annually  173  casks  of  950  pounds  each. 
Petroleum  is  also  found  at  Amiano  in  the  duchy  of  Parma,  at  Saint  Zibio  in  the  grand 
duchy  of  Modena,  at  Neufchatel  in  Switzerland,  at  Clermont  in  France,  upon  some 
points  of  the  banks  of  the  Iser,  at  Gabian,  a  vill^e  near  Bezi^res,  at  Tegernsee  in  Ba- 
varia, at  Val  di  Noto  in  Sicily,  in  Zante,  Gallicia,  Wallachia,  Trinidad,  Barbadoes, 
the  United  States,  Rangoon,  near  Ava,  <fec.  What  is  found  in  the  market  comes  most- 
ly from  Trinidad.     The  city  of  Parma  is  lighted  with  naphtha. 

The  Persian  rock-oil  is  colorless,  limpid,  very  fluid,  of  a  penetrating  odor,  a  hot  taste, 
and  a  specific  gravity  of  0-653 ;  it  is  said  to  boil  at  160°  F.  The  common  petroleum  has 
a  reddish-yellow  color,  which  appears  blue  by  reflected  light,  is  transparent,  has  a 
spec.  grav.  of  0*836,  and  contains,  according  to  Unverdorben,  several  oils  of  different 
degrees  of  volatility,  a  little  oleine  and  stearine,  resin,  with  a  brown  indifferent  sub- 
stance held  in  solution.  By  repeated  rectifications  its  density  may  be  reduced  to 
0'758  at  60°  F.  Native  naphtha  of  specific  gravity  0.749,  is  said  by  some  to  boil  at 
201°  F.     The  condensed  vapor  consists  of  8505  carbon,  and  14*30  hydrogen. 

The  naphtha  procured  by  distilling  the  coal  oil  of  the  gas  works,  is  of  specific  gravi- 
ty 0*857,  boils  at  316°  F.,  and  consists  o^  carbon  83*04,  hydrogen  12*31,  and  oxygen 
4'65,  by  my  experiments.  ^  t^ 

Rock-oil  is  very  inflammable ;  its  vapor  forma  with  oxygen  gas  a  mixture  which  vio- 


NAPHTHALINE. 


25; 


lently  detonates,  and  produces  water  and  carbonic  acid  gas.  It  does  not  unite  witJi 
water,  but  it  imparts  a  peculiar  smell  and  taste  to  it ;  it  combines  in  all  proportions 
with  strong  alcoliol,  with  ether  and  oils,  both  essential  and  unctuous ;  it  dissolves  sul- 
phur, ph(i8])horu3,  iodine,  camphor,  most  of  the  resins,  wax,  fats,  and  softens  caoiitehou« 
into  a  glairy  varnish.  When  adulterated  with  oil  of  turpentine,  it  becomes  thick  and 
reddisli  brown,  on  being  agitated  in  contact  with  strong  sulphuric  acid.  A  very  fine 
black  pigment  may  be  prejmrecl  from  the  soot  of  petroleum  lamps. 

NAPHTHA  A^D  ITS  USES.— In  the  Fharm.  Journal  for  July,  1848,  a  notice  was 
inserted  about  the  curative  virtue  of  mineral  naphtha  in  Asiatic  cholera,  as  verified 
by  Dr.  Audreosky,  physician  to  the  commander-in-chief  of  the  Russian  array  in  Cir- 
eassia.  The  naphtha  there  employed  has  been  long  known  as  the  produce  of  springs 
on  the  north-west  coast  of  the  Caspian  Sea,  not  far  from  the  town  of  Derbend,  near  the 
Gulf  of  Baku,  which  was  incorrectly  printed  Beker.  It  is  surprising  that  in  the  in- 
structions of  the  Petersburg  police  board  just  published,  as  to  the  proper  precautions 
and  best  remedies  against  cholera,  then  beginning  its  ravages  in  that  capital,  no  allusion 
whatever  was  made  to  naphtha,  or  to  Dr.  Andreosky's  testimony  in  its  favor.  Are  we 
hence  to  infer  that  the  preceding  recommendation  of  that  substance  is  apocryphal,  or 
that  it  has  since  lost  all  credit  with  the  Russian  faculty,  by  whom  the  police  bulletin 
was  prepared  ? 

The  soil  near  Derbent,  from  which  the  naphtha  oozes  into  wells  about  thirtv  inches 
deep,  is  a  clay  marl,  which  is  thoroughly  soaked  with  that  fluid.  It  has  a  pale  yellow 
color,  like  that  of  Amiano  near  Parma,  in  Italy,  but  has  a  specific  gravity  of  0*863,  while 
that  of  Amiano  is  only  0*836.  Their  boiling  point  is  about  305°  Fahr.  Submitted  to 
distillation,  it  affords  a  colorless  fluid  of  spec.  grav.  0.728,  which  boils  at  about  176° 
Fahr.,  but  has  acquired  an  empyreumatic  odor,  very  different  from  that  of  the  native 
product.  Barbadoes  tar  of  the  best  kind  differs  from  these  naphthas  only  in  containing 
a  little  more  bitumen,  but  it  is  equally  fragrant.  When  distilled  it  yields  a  similar  light- 
er naphtha,  but  likewise  empyreumatic  The  native  substances  are  composed  of  6  at- 
oms of  carbon  and  6  atoms  of  hydrogen ;  or  in  100  parts,  of  86  and  14,  by  Hess's  analysia 

Mineral  petroleum  seems  to  be  very  different  in  constitution  and  qualities  from  the 
fetid,  factitious  tar,  derived  from  the  igneous  decomposition  of  pit-coaL  Tiie  latter, 
according  to  Mr.  Mansfield,  is  resolvable  into  six  different  substances,  which  he  names 
allio/e,  benzole,  toluole,  camphole,  mortuole,  and  nitro-benzole.  I  do  not  believe  that  a 
series  of  similar  bodies  can  be  extracted  from  native  bitumen  or  petroleum.  Indeed, 
he  himself  informed  me  that  the  fluid  bitumen  at  one  time  pumped  up  abundantly  from 
the  Redding  coalmines  in  Derbyshire,  of  which  I  furnished  him  with  a  specimen,  af^ 
forded  no  such  distinction  of  products,  a  result  in  accordance  with  my  own  experience. 
These  differences  between  the  natural  and  factitious  petroleums  lea'd  me  to  conclude 
that  the  former  are  not  the  result  of  igneous  action,  but  of  that  of  water  upon  carbo- 
nacesus  matter  in  the  mineral  strata.  In  confirmation  of  which  view  it  may  be  ob- 
served, that  not  on\y  in  the  above-named  localities,  but  also  at  Monte  Ciaro  near  Pia- 
cenza,  at  the  Lake  of  Tegern  in  Bavaria,  near  Neufohatel  in  Switzerland,  in  the  De- 
partment of  the  Ain  in  France,  &c.,  the  bitumen  is  accompanied  with  a  copious  flow 
of  water,  on  which  it  floats,  and  from  which  it  is  skimmed. 

Petroleum  of  various  shades,  from  the  green  of  the  Barbadoes  springs  to  the  pale 
yellow  of  Amiano,  has  been  long  known  to  possess  certain  medicinal  properties.  The 
rock-oil  of  Barbadoes,  or  as  it  has  been  vulgarly  but  improperly  called,  Barbadoes-tar, 
nas  been  found  an  useful  stimulant  to  torpid  bowels,  promoting  in  such  a  tcmperameni 
the  alvine  discharge.  Its  chief  value,  however,  is  as  an  external  remedy  in  a  variety 
ot  cutaneous  affections.  But  petroleum,  either  by  itself,  or  combinedf  with  any  <rf 
ita  solvent  essential  oils  or  spirits,  would  in  general  act  rather  as  an  irritant  and  ru- 
Deiacient  upon  the  skm  in  such  cases,  than  as  a  purifying,  cleansing,  and  soothing  ap- 
plication. In  this  dilemma  the  idea  occurred  of  incorporating  the  green  rcck-oil 
witH  line  curd  soap.  Thus  a  truly  balsamic  compound  has  been  obtained.  When  the 
soap,  used  with  water  in  the  usual  way,  has  cleared  out  the  cutaneous  pores,  a  film  of 
the  petroleum  18  deposited  in  them,  powerfully  remedial  in  many  of  the  morbid  affec- 
tions oi  the  skin^  buch  petrolized  soap  has  been  found  to  be  quite  a  specific  in  the 
prickly  heat  of  tropical  regions,  and  of  equal  efficacy  in  the  fiery  eruptions  incident 
to  many  persons  m  temperate  climates.  Hitherto,  no  method  had  been  devised  for 
Trtfir^^^ofn-f^^'r'^^  ^^'^  alkalinity  of  soap,  which  being,  as  in  the  best  white  curd 
article^  a  definite  saline  compound  of  stearic  acid,  and  soda  in  it«  most  caustic  condi- 
tion  to  the  extent  of  six  per  cent,  cannot  fail  to  excoriate  delicate  skins.  By  the  pres- 
t\;i*£?tT  '„7^''.^^?'  each  particle  of  that  salt  is  enveloped  with  a  film  of  baUaim, 
iMr '?n  VJ'  »r"tant,  without  interfering  with  its  detergent  quality.  Henoi 
717,1  fhAn n  f'V*  *^«P^t^f  ^««e  given  to  the  petroline  soap  by  allVho  LbituaUy 
use  It  at  the  toilet-table.— PAanw.  J&um.  vol.  viii  No  9  "^  ^ 

NAraTHALINK  is  a  peculiar  white    crystailizable    substance,  which  may   be 


258 


NEEDLE  MANUFACTURE. 


NEEDLE  MANUFACTURE. 


extracted  by  distillation  from  coal  tar.  It  has  a  pungent  aromatic  smell  and  taste,  and 
a  apecific  gravity  of  1-048.  It  is  a  solid  bicarburet  of  hydrogen,  consisting,  by  my  ex- 
periments, of  92-9  of  carbon,  and  7"1  of  hydrogen.     It  has  not  been  applied  to  any  use. 

NAPLliS  YELLOW  {Jaune  mineral,  Fr. ;  Neapelgelb,  Germ.);  is   a  tine  yellow  pig 
ment  called  ^«a//o/mo,  in  Italy,  where  it  has  been  long  prepared  by  a  secret  process; 
for  few  of  the  receipts  which  have  been  published  produce  a  good  color.    It  is  em- 
ployed not  only  in  oil  painting,  but  also  forporcelam  and  enamel.     It  has  a  fresh, 
brilliant,  rich  hue,  but  is  apt  to  be  very  unequal  in  different  samples. 

The  following  prescription  has  been  confidenoly  recommended.  Twelve  parts  of  me- 
tallic antimony  are  to  be  calcined  in  a  reverberator^  furnace,  along  with  eight  parts 
of  red  lead,  and  four  parts  of  oxide  of  zinc.  These  mixed  oxides  being  well  rubbed  to- 
gether are  to  be  fused  ;  and  the  fused  mass  is  to  be  triturated  and  elutriated  into  a  fine 
powder.     Chromate  of  lead  has  in  a  great  measure  superseded  Naples  yellow. 

NATRON  is  the  name  of  the  native  sesquicarbonate  of  soda,  which  occurs  in  Egypt, 
in  the  west  of  the  Delta  ;  also  in  the  neighborhood  of  Fessan,  in  the  province  of  Sukena 
in  Northern  Africa,  where  it  exists  under  the  name  of  Trona,  crystallized  along  with  sul- 
phate of  soda  ;  near  Symrna,  in  Tartary,  Siberia,  Hungary,  Hindostan,  and  Mexico.  In 
the  last  country,  there  are  several  natron  lakes,  a  little  to  the  north  of  Zucalecas,  as  well 
as  in  many  other  provinces.  In  Columbia,  48  miles  from  Merida,  native  mineral  natron 
IS  dug  up  from  the  bottom  of  lakes  in  large  quantities,  under  the  name  of  Urao. 

According  to  Laugier,  the  Egyptian  natron  consists  of  carbonate  of  soda  22-44,  sulphate 
of  soda  18-35,  muriate  of  soda  38-64,  water  14-0,  insoluble  matter  6-0.  Trona  is  com- 
posed of  carbonate  of  soda  65-75,  sulphate  of  soda  7-65,  muriate  of  soda  2-63,  water  24, 
insoluble  matter  1.  The  sesquicarbonate  may  be  artificially  prepared  by  boiling  for  a 
short  time  a  solution  of  the  bicarbonate. 

NEALING.     See  Anneaung. 

NEB-NEB  is  the  East  Indian  name  of  Bablah. 

NEEDLE  MANUFACTURE.  When  we  consider  the  simplicity,  smallness,  and 
moderate  price  of  a  needle,  we  would  be  naturally  led  to  suppose  that  this  little  instru- 
ment  requires  neither  much  labor  nor  complicated  manipulations  in  its  construction ;  but 
when  we  learn  that  every  sewing  needle,  however  inconsiderable  its  size,  passes  through 
the  hands  of  120  different  operatives,  before  it  is  ready  for  sale,  we  cannot  fail  to  be 

sui prised.  .    ,,     j. 

The  best  steel,  reduced  by  a  wire-drawing  machine  to  the  suitable  diameter,  is 
the  material  of  which  needles  are  formed.  It  is  brought  in  bundles  to  the  needle  fac- 
tory, and  carefully  examined.  For  this  purpose,  the  ends  of  a  few  wires  in  each  bundle 
are  cut  off,  ignited,  and  hardened  by  plunging  them  into  cold  water.  They  are  now 
snapped  between  the  fingers,  in  order  to  judge  of  their  quality ;  the  bundles  belongmg 
to  the  most  brittle  wires  are  set  aside,  to  be  employed  in  making  a  peculiar  kind  of 

needles. 

After  the  quality  of  the  steel  wire  has  been  properly  ascertained,  it  is  calibred  by  means 
of  a  gauge,  to  see  if  it  be  equally  thick  and  round  throughout,  for  which  purpose  merely 
gome  of  tTie  coils  of  the  bundle  of  wires  are  tried.  Those  that  are  too  thick  are  returned 
to  the  wire-drawer,  or  set  apart  for  another  size  of  needles. 

The  first  operation,  properly  speaking,  of  the  needle  factory,  is  unwinding  the  bundles 
of  wires.  With  this  view  the  operative  places  the  coil  upon  a  somewhat  conical  reel, 
fiz.  750,  whereon  he  may  fix  it  at  a  height  proportioned  to  its  diameter.  The  wire  is 
wound  off  upon  a  wheel  b,  formed  of  eight  equal  arms,  placed  at  e(iual  distances  round 
a  nave,  which  is  supported  by  a  polished  round  axle  of  iron,  made  fast  to  a  strong 
upright  c,  fixed  to  the  floor  of  the  workshop.  Each  of  the  arms  is  54  inches  long  ;  and 
one  of  them  d,  consists  of  two  parts ;  of  an  upper  part,  which  bears  the  cross  bar  k,  to 
which  the  wire  is  applied  ;  and  of  an  under  part,  connected  with  the  nave.  The  part 
K  slides  in  a  slot  in  the  fixed  part  f,  and  is  made  fast  to  it  by  a  peg  at  a  proper  height 
for  placing  the  ends  of  all  the  spokes  in  the  circumference  of  a  circle.  This  arrange- 
ment is  necessary,  to  permit  the  wire  to  be  readily  taken  off  the  reel,  after  being 
wound  tight  round  its  eight  branches.  The  peg  is  then  removed,  the  branch  pushed 
down,  and  the  coil  of  wire  released.  Fig.  993  shows  the  wheel  in  profile.  It  is  driv- 
en by  the  winch-handle  o. 

The  new  made  coil  is  cut  in  two  points  diametrically  opposite,  either  by  hand  shears, 
of  which  one  of  the  branches  is  fixed  in  a  block  by  a  bolt  and  a  nut,  as  shown  xnfig. 
994,  or  by  means  of  the  mechanical  shears,  represented  in  Ji^.  995.  The  crank  a  is 
moved  by  a  hydraulic  wheel,  or  steam  power,  and  rises  and  falls  alternately,  llie  ex- 
tremity of  this  crank  enters  into  a  mortise  cut  in  the  arm  b  of  a  bent  lever  b  a  c,  and 
is  made  fast  to  it  by  a  bolt  An  iron  rod  d  k,  hinged  at  one  of  its  extremities  to  the 
end  of  the  arm  c,  and  at  the  other  to  the  tail  of  the  shears  or  chisel  e,  forces  it  to  open 
and  shut  alternately.  The  operative  placed  upon  the  floor  under  f  present*  the  coil 
to  the  action  of  the  shears,  which  cut  it  into  two  bundles,  composed  each  of  60  or 
100  wires,  upwards  of  3  feet  long.    The  chisel  strikes  21  blows  in  the  minute. 


I 


These  bundles  are  afterwards  cut  with  the  same  shears  into  the  desired  needle  lengths, 
these  being  regulated  by  the  diameter.  For  this  purpose  the  wires  are  put  into  a  semi- 
cylinder  of  the  proper  length,  with  their  ends  at  the  bottom  of  it,  and  are  all  cut  across 
by  this  gauge.  The  wires,  thus  cut,  are  deposited  into  a  box  placed  alongside  of  the 
workman. 

Two  successive  incisions  are  required  to  cut  100  wires,  the  third  is  lost ;  hence  the 
shears,  striking  21  blows  in  a  minute,  cut  in  10  hours  fully  400,000  ends  of  steel  wire, 
which  produce  more  than  800,000  needlea  The  wires  thus  cut  are  more  or  less  bent, 
and  require  to  be  straightened.  This  operation  is  executed  with  great  promptitude, 
by  means  of  an  appropriate  instrument  In  two  strong  iron  rings  a  b.  Jig.  996,  of  which 
one  is  shown  in  front  view  at  c,  6000  or  6000  wires,  closely  packed  together,  are  put; 
and  the  bundle  is  placed  upon  a  flat  smooth  bench  l  m,  jig.  999,  covered  with  a  cast-iron 
plate  D  E,  in  whi<;h  there  are  two  grooves  of  sufficient  depth  for  receiving  the  two  ring 
bundles  of  wire,  or  two  openings  like  the  rule  f,  fig.  999,  upon  which  is  placed  the 
open  rule  f,  shown  in  front  in  /or.  998  upon  a  greater  scale.  The  two  rings  must  be 
carefully  set  at  the  int-ervals  of  the  rule.  By  making  this  rule  come  and  go  five  or  six 
times  with  such  pressure  upon  the  bundles  of  wires  as  causes  it  to  turn  upon  its  axis,  all 
the  wires  are  straightened  almost  instantaneously. 

The  construction  of  the  machine,  represented' in  fig.  999,  may  require  explanation. 
It  consists  of  a  frame  in  the  form  of  a  table,  of  which  l  m  is  the  top ;  the  cast- 
iron  plate  D  E  is  inserted  solidly  into  it.  Above  the  table,  seen  in  fig,  997  in  plan, 
there  are  two  uprights  c  h,  to  support  the  cross  bar  a  a,  which  is  held  in  forks  cut  oat 
in  the  top  of  each  of  the  two  uprights.  This  cross  bar  a  a,  enters  tightly  into  a 
mortise  cut  in  the  swing  piece  n,  at  the  point  N,  where  it  is  fixed  by  a  strong  pm,  so  that 

the  horizontal  traverse  communicated  to  the  cross 
bar  A  A  affects  at  the  same  tune  the  swing  piece  h. 
At  the  bottom  of  this  piece  is  fixed,  as  shown  in  the 
figure,  the  open  rule  f,  seen  upon  a  greater  scale 
in  fig.  998. 

When  the  workman  wishes  to  introduce  the 
bundle  b,  he  raises,  by  means  of  two  chains  i  k, 
fig.  999,  and  the  lever  g  o,  the  swing  piece  and 
the  cross  bar.  For  this  purpose  he  draws  down  the 
chain  i;  and  when  he  has  placed  the  bundle 
properly,  so  that  the  two  rings  enter  into  the  groove 
E  Hi  fig.  997,  he  allows  the  swing  piece  to  fall  hack, 
so  that  the  same  rings  enter  the  open  cleAs  of  the 
rule  F;  he  then  seizes  one  of  the  projecting  arms 
of  the  cross  bar  a,  alternately  nulling  and  pushing 
it  in  the  horizontal  direction,  whereby  he  effects,  as 
already  stated,  the  straightening  of  the  wires. 

The  wires  are  now  taken  to  the  pointing-tools, 
which  usually  consist  of  about  30  grindstones 
arranged  in  two  rows,  driven  by  a  water-wheeL 


M 


997 

« 
1 

D 

^ 

E 

C 

260 


NEEDLE  MANUFACTURE. 


1002 

n 


1000 


B 


=^^ 


3 


Each  stone  is  about  1 8  in.  in  diameter,  and  4  in.  thick.  As  they  revolve  with  great  velocity 
and  are  liable  to  fly  in  pieces,  they  are  partially  encased  by  iron  plates,  having  a  proper 
slit  in  them  lo  admit  of  the  application  of  the  wires.    The  workman  seated  in  front 

of  the  grindstone,  seizes  50  or  60  wires 
between  the  thumb  and  forefinger  of  his 
right  hand,  and  directs  one  end  of  the 
bundle  to  the  stone.  By  means  of  a  bit  of 
stout  leather  called  a  thumb-piece,  of 
which  A,  yZg.  1000,  represents  the  profile, 
and  B  the  plan,  the  workman  presses  the 
wires,  and  turns  them  about  with  his  fore- 
finger, giving  them  such  a  rotatory  mo- 
tion as  to  make  their  points  conical.  This 
operation,  which  is  called  roughing  dovm^ 
is  dry  grinding ;  because,  if  water  were 
made  use  of,  the  points  of  the  needles  would  be  rapidly  rusted.  It  has  been  observed 
long  ago,  that  the  silicious  and  steel  dust  thrown  off  by  the  stones,  was  injurious  to  the 
eyes  and  lungs  of  the  grinders ;  and  many  methods  have  been  proposed  for  preventing 
its  bad  effects.  The  machine  invented  for  this  purpose  by  Mr.  Prior,  for  which  the 
Society  of  Arts  voted  a  premium,  deserves  to  be  generally  known. 

^  ^j  ^g.  1001,  is  the  fly-wheel  of  an  ordinary  lathe,  round  which  the  endless  cord  b  b 
passes,  and  embraces  the  pulley  c,  mounted  upon  the  axle  of  the  grindstone  d.  The  fly- 
wheel is  supported  by  a  strong  frame  e  e,  and  may  be  turned  by  a  winch- handle,  as  usual, 
or  by  mechanical  power.  In  the  needle  factories,  the  pointing-shops  are  in  general 
very  large,  and  contain  several  grindstones  running  on  the  same  Ions:  horizontal  shaft, 
placed  near  the  floor  of  the  apartment,  and  driven  by  water  or  steam  power.  One  of  the 
extremities  of  the  shaft  of  the  wheel  a  has  a  kneed  or  bent  winch  f,  which  by  means  of 
an  intermediate  crank  g  g,  sets  in  action  a  double  bellows  h  i,  with  a  continuous  blast, 
consisting  of  the  air  feeder  h  below,  and  the  air  regulator  i  above.  The  first  is  com- 
posed of  two  flaps,  one  of  them,  a  a,  being  fast  and  attached  to  the  floor,  and  the  other, 
e  «,  moving  with  a  hinge-joint ;  both  being  joined  by  strong  leather  nailed  to  their  edges. 
This  flap  has  a  tail  g,  of  which  the  end  is  forked  to  receive  thj  end  of  the  crank  o. 
Both  flaps  are  perforated  with  openings  furnished  with  valves  for  the  admission  of  the 
air,  which  is  thence  driven  into  a  horizontal  pipe  k,  placed  beneath  the  floor  of  the  work- 
shop, and  may  be  afterwards  directed  in  an  uninterrupted  blast  upon  the  grindstone,  by 
means  of  the  tin  tubes  n  o  o,  which  embrace  it,  and  have  longitudinal  slits  in  them.  A 
brass  socket  is  supposed  to  be  fixed  upon  the  ground  ;  it  communicates  with  the  pipe  k, 
by  means  of  a  small  copper  tube,  into  which  one  of  the  extremities  of  the  pipe  n  is  fit- 
ted ;  the  other  is  supported  by  the  point  of  a  screw  q,  and  moves  round  it  as  a  pivot,  so 
as  to  allow  the  two  upright  branches  o  o,  to  be  placed  at  the  same  distance  from  the 
grindstone.  These  branches  are  soldered  to  the  horizontal  pipe  n,  and  connected  at  their 
top  by  the  tube  p. 

The  wind  which  escapes  through  the  slits  of  these  pipes,  blows  upon  the  grindstone, 
and  carries  off*  its  dust  into  a  conduit  r,  ^g.l001,which  may  be  extended  to  s,  beyond 
the  wall  of  the  building,  or  bent  at  right  angles,  as  at  t,  to  receive  the  conduits  of  the 
other  grindstones  of  the  factory. 


A  safety  valve  J,  placed  in  an  orifice  formed  in  the  regulator  flap  i,  is  kept  shut  by  a 


NEEDLE  MANUFACrrURE. 


161 


spiral  spring  ot  strong  iron  wire.  It  opens  to  allow  the  superfluous  air  to  escape,  when, 
by  the  rising  of  the  bellows,  the  tail  l  presses  upon  a  small  piece  of  wood,  and  thereby 
prevents  their  being  injured. 

The  wires  thus  pointed  at  both  ends  are  transferred  to  the  first  workshop,  and  cut  in 
two,  to  form  two  needles,  so  that  all  of  one  quality  may  be  of  equal  length.  For  each 
sort  a  small  instrument,  yig.1002,  is  employed,  being  a  copper  plate  nearly  square,  having 
a  turned  up  edge  only  upon  two  of  its  sides ;  the  one  of  which  is  intended  to  receive  all 
the  points,  and  the  other  to  resist  the  pressure  of  the  shears.  In  this  small  tool  a  certain 
number  of^  wires  are  put  with  their  points  in  contact  with  the  border,  and  they  are  cut 
together  flush  with  the  plate  by  means  of  the  shears.  Jig.  994,  which  are  moved  by  the 
knee  of  the  workman.  The  remainder  of  the  wires  are  then  laid  upon  the  same  copper 
or  brass  tool,  and  are  cut  also  even ;  there  being  a  trifling  waste  in  this  operation.  The 
pieces  of  wire  out  of  which  two  needles  are  formed,  are  always  left  a  little  too  long,  as 
the  pointer  can  never  hit  exact  uniformity  in  his  work. 

These  pointed  wires  are  laid  parallel  to  each  other  in  little  wooden  boxes,  and  transfer* 
red  to  the  head-flattener.  This  workman,  seated  at  a  table  with  a  block  of  steel  before 
him,  about  3  inches  cube,  seizes  in  his  left  hand  20  or  25  needles,  between  his  finger  and 
thumb,  spreading  them  out  like  a  fan,  with  the  points  under  the  thumb,  and  the  heads 
projecting ;  he  lays  these  heads  upon  the  steel  block,  and  with  a  small  flat-faced  hammer 
strikes  successive  blows  upon  all  the  heads,  so  as  to  flatten  each  in  an  instant.  He  then 
arranges  them  in  a  box  with  the  points  turned  the  same  way. 

The  flatted  heads  have  become  hardened  by  the  blow  of  the  hammer ;  when  annealed 
by  heating  and  slow  cooling,  they  are  handed  to  the  piercer.  This  is  commonly  a  chUd, 
who  laying  the  head  upon  a  block  of  steel,  and  applying  the  point  of  a  small  punch  to 
it,  pierces  the  eye  with  a  smart  tap  of  a  hammer,  applied  first  upon  the  one  side,  and 
then  exactly  opposite  upon  the  other. 

Another  child  trims  the  eyes,  which  he  does  by  laying  the  needle  upon  a  lump  of  lead, 
and  driving  a  proper  punch  through  its  eye  ;  then  laying  it  sidewise  upon  a  flat  piece  of 
steel,  with  the  punch  sticking  in  it,  he  gives  it  a  tap  on  each  side  with  his  hammer,  and 
causes  the  eye  to  take  the  shape  of  the  punch.  The  operation  of  piercing  and  trimming 
the  eyes,  is  performed  by  clever  children  with  astonishing  rapidity  ;  who  become  so  dex- 
terous as  to  pierce  with  their  punch  a  human  hair,  and  thread  it  with  another,  for  the 
amusement  of  visiters. 

The  next  operative  makes  the  groove  at  the  eye,  and  rounds  the  head.  He  fixes  the 
needle  in  pincers,  ^g.  1003, so  that  the  eye  corresponds  to  their  flat  side  ;  he  then  rests  the 
head  of  the  needle  in  an  angular  groove,  cut  in  a  piece  of  hard  wo(Ki  fixed  in  a  vice, 
with  the  eye  In  an  upright  position.  He  now  forms  the  groove  with  a  single  stroke 
of  a  small  file,  dexterously  applied,  first  to  the  one  side  of  the  needle,  and  then  lo  the 
other.  He  next  rounds  and  smooths  the  head  with  a  small  flat  file.  Having  finished, 
he  opens  the  pincers,  throws  the  needle  upon  the  bench,  and  puts  another  in  its  place. 
A  still  more  expeditious  method  of  making  the  grooves  and  finishing  the  heads  has 
been  long  used  in  most  English  factories.  A  small  ram  is  so  mounted  as  to  be  made  to 
rise  and  fall  by  a  pedal  lever,  so  that  the  child  works  the  tool  with  his  foot ;  in  the 
same  way  as  the  heads  of  pins  are  fixed.  A  small  die  of  tempered  steel  bears  the  form 
of  the  one  channel  or  groove,  another  similar  die,  that  of  the  other,  both  being  in  relief; 
these  being  worked  by  the  lever  pedal,  finish  the  grooving  of  the  eye  at  a  single  blow,  by 
striking  against  each  other,  with  the  head  of  the  needle  between  them. 

The  whole  of  the  needles  thus  prepared  are  thrown  pell-mell  into  a  sort  of  drawer  or 
box,  in  which  they  are,  by  a  few  dexterous  jerks  of  the  workman's  hand,  made  to  arrange 
themselves  parallel  to  each  other. 

The  needles  are  now  ready  for  the  tempering ;  for  which  purpose  they  are  weighed  out 
m  quantities  of  about  30  pounds,  which  contain  from  250,000  to  500,000  needles,  and  are 
carried  in  boxes  to  the  temperer.  He  arranges  these  upon  sheet-iron  plates,  about  10 
inches  long,  and  5  inches  broad,  having  borders  only  upon  the  two  longer  sides.  These 
plates  are  heated  in  a  proper  furnace  to  bright  redness  for  the  larger  needles,  and  lo  a 
less  intense  degree  for  the  smaller ;  they  are  taken  out,  and  inverted  smartly  over  a  cis- 
tern of  water,  so  that  all  the  needles  may  be  immersed  at  the  same  moment,  yet  distinct 
from  one  another.  The  water  being  run  oflT  from  the  cistern,  the  needles  are  removed, 
and  arranged  by  agitation  in  a  box,  as  above  described.  Instead  of  heating  the  needles 
in  a  furnace,  some  manufacturers  heat  them  by  means  of  a  bath  of  melted  lead  in  a  state 
of  Ignition. 

After  being  suddenly  plunged  in  the  cold  water,  they  are  very  hard  and  excessively 
brittle.  The  following  mode  of  tempering  them  is  practised  at  Neustadt.  The  needles 
are  thrown  into  a  sort  of  frying-pan  along  with  a  quantity  of  grease.  The  pan  being 
placed  on  the  fire,  the  fatty  mailer  soon  inflames,  and  is  allowed  to  bum  out;  the 
needles  are  now  found  to  be  suflicienlly  well  tempered.  They  must,  however,  be 
re-adjusted  upon  the  steel  anvil,  because  many  of  them  get  twisted  in  the  hardening  and 
tempering. 


\i 


m 


Heedle  manufacture. 


Polishing  is  the  longest  and  not  the  least  expensive  process  in  the  needle  mannfactum 
This  is  done  upon  bundles  containing  500,000  needles ;  and  the  same  machine,  undet 
the  guidance  of  one  man,  polishes  from  20  to  30  bundles  at  a  time  ;  either  by  water  oi 
steam  power.  The  needles  are  rolled  up  in  canvass  along  with  some  quartzose  sand 
interstratified  between  their  layers,  and  the  mixture  is  besmeared  with  rape-seed  oil. 
Fig.  1004  represents  one  of  the  rolls   or  packets  of  needles  12  inches  long,  strongiy 

1005  j^^ 

L 


bound  with  cords.  These  packets  are  exposed  to  the  to-and-fro  pressure  of  wooden 
tables,  by  which  they  are  rolled  about,  with  the  effect  of  causing  every  needle  in  the 
bundle  to  rub  against  its  fellow,  and  against  the  silicious  matter,  or  emery,  enclosed 
in  the  bag.  Fig.  1005  represents  an  improved  table  for  polishing  the  needles  by  attri- 
tion-bags. The  lower  table  m  m  is  moveable,  whereas  in  the  old  constructions  it  was 
fixed ;  the  table  c  has  merely  a  vertical  motion,  of  pressure  upon  the  bundles,  whereas 
formerly  it  had  both  a  vertical  and  horizontal  motion.  Several  bundles  may  obviously 
be  polished  at  once  in  the  present  machine.  The  table  m  m  may  be  of  any  length  that 
is  required,  and  from  24  to  27  inches  broad ;  resting  upon  the  wooden  follers  b,  b,  b, 
placed  at  suitable  distances,  it  receives  a  horizontal  motion,  either  by  hand  or  other 
convenient  power ;  the  packets  of  needles  a,  a,  a,  are  laid  upon  it,  and  over  them  the 
tables  c,  c,  c,  which  are  lifted  by  means  of  the  chains  k,  k,  k,  and  the  levers  l,  l,  l,  in 
order  to  allow  the  needles  to  be  introduced  or  removed.  The  see-saw  motion  forces 
the  rouleaux  to  turn  upon  their  own  axes,  and  thereby  creates  such  attrition  among 
their  contents  as  to  polish  them.  The  workman  has  merely  to  distribute  these  rolls 
upon  the  table  m,  in  a  direction  perpendicular  to  that  in  which  the  table  moves ;  and 
whenever  one  of  them  gets  displaced,  he  sets  it  right,  lifting  by  the  help  of  the  chain 
the  loaded  table.  The  table  msikes  about  20  horizontal  double  vibrations  in  the  minute ; 
whereby  each  bundle,  running  over  24  inches  each  time,  passes  through  40  feet  per  minute, 
or  800  yards  in  the  hour. 

Scouring  by  the  cask.  After  being  worked  during  18  or  20  hours  under  the  tables,  the 
needles  are  taken  out  of  the  packets,  and  put  into  wooden  bowls,  where  they  are  mixed 
with  sawdust  to  absorb  the  black  grease  upon  their  surfaces.  They  are  next  introduced 
into  a  cask, ^ig.  1006,  and  a  workman  seizing  the  winch  r,  turns  it  round  a  little  ;  he  now 
puts  in  some  more  sawdust  at  the  door,  a,  b,  which  is  then  shut  by  the  clasps  g  g,  and 
continues  the  rotation  till  the  needles  be  quite  clean  and  clear  in  their  eyes ;  which  he 
ascertains  by  taking  out  a  sample  of  them  from  time  to  time. 

Winnoioing  is  the  next  process,  by  means  of  a  mechanical  ventilator  similar  to  that  hf 
which  corn  is  winnowed.  The  sawdust  is  blown  away,  and  the  grinding  powder  is 
separated  from  the  needles,  which  remain  apart  clean  and  bright. 

The  needles  are  in  the  next  place  arranged  in  order,  by  being  shaken,  as  above  de- 
scribed, in  a  small  somewhat  concave  iron  tray.  After  being  thus  laid  parallel  to  each 
other,  they  are  shaken  up  against  the  end  of  the  tray,  and  accumulated  in  a  nearly  up- 
right position,  so  that  they  can  be  seized  in  a  heap  and  removed  in  a  body  upon  a  pallet 
knife,  with  the  help  of  the  forefinger. 

The  preceding  five  operations,  of  making  up  the  rouleaux,  rolling  them  under  the 
tables,  scouring  the  needles  in  the  cask,  winnowing,  and  arranging  them,  are  repeated 


NEEDLE  MANUFACTURE. 


263 


k.-^ 


fen  times  in  soccession,  in  manufacturing  the  best  articles ;  the  only  variation  being  in 
the  first  process.  Originally  the  bundles  of  needles  are  formed  with  alternate  layers  of 
silicious  schislus  and  needles ;  but  after  the  seventh  time,  bran  freed  from  flour  by  sift- 
ing is  substituted  for  the  schistus.  The  subsequent  four  processes  are,  however,  repeat- 
ed as  described.     It  has  been  found  in  England,  that  emery  powder  mixed  with  quartz  and 

1008  1007 


mica  or  pounded  granite,  is  preferable  to  everything  else  for  polishing  needles  at  first  by 
attrition  in  the  ba?s ;  at  the  second  and  following  operations,  emery  mixed  with  olive  oU 
is  used,  up  to  the  eighth  and  ninth,  for  which  putty  or  oxyde  of  tin  with  oil  is  substituted 
for  the  emery ;  at  the  tenth  the  putty  is  used  with  very  little  oil ;  and  lastly  bran  is  em- 
ployed to  give  a  finish.  In  this  mode  of  operating,  the  needles  are  scoured  in  the  copper 
cask  shown  in  elevation  in  Jig.  1007  and  in  section  in^g.  1008.  The  inner  surface  of  this 
cask  is  studded  with  points  to  increase  the  friction  among  the  needles ;  and  a  quantity  of 
hot  soap  suds  is  repeatedly  introduced  to  wash  them  clean.  The  cask  must  be  slowly 
turned  upon  its  axis,  for  fear  of  injuring  the  mass  of  needles  which  it  contains.  They 
are  finally  dried  in  the  wooden  cask  by  attrition  with  sawdust;  then  wiped  individually 
with  a  linen  rag  or  soft  leather ;   when  the  damaged  ones  are  thrown  aside. 

Sorting  of  the  needles.  This  operation  is  performed  in  a  dry  upper  chamber,  kept  free 
from  damp  by  proper  stoves.  Here  all  the  points  are  first  laid  the  same  way ;  and  the 
needles  are  then  picked  out  from  each  other  in  the  order  of  their  polish.  The  sorting  is 
^ected  with  surprising  facility.  The  workman  places  2000  or  3000  needles  in  an  iron 
rins:,^g.  1009, two  inches  in  diameter,  and  sets  all  their  heads  in  one  plane;  then  oa 
lookina:  carefully  at  their  points,  he  easily  recognises  the  broken  ones ;  and  by  means  of 
a  small  hook  fixed  in  a  wooden  handle,^g.l010,he  lays  hold  of  the  broken  needle,  and 
turns  it  out.  These  defective  needles  pass  into  the  hands  of  another  workman,  who 
points  them  anew  upon  a  grindstone,  and  they  form  articles  of  inferior  value.  The  needles 
which  have  got  bent  in  the  polishing  must  now  be  straightened.  The  whole  are  finally 
arranged  exactly  according  to  their  lengths  by  the  tact  of  the  finger  and  thumb  of  th« 
sorter. 

The  needles  are  divided  into  quantities  for  packing  in  blue  papers,  by  patting  into  a 
small  balance  the  equivalent  weight  of  100  needles,  and  so  measuring  them  out  without 
the  trouble  of  counting  them  individually. 

The  bluer  receives  these  packets,  and  taking  25  of  their  needles  at  a  time  between  the 
forefinger  and  thumb,  he  presses  their  points  against  a  very  small  hone-stone  of  compact 
micaceous  schist,  mounted  in  a  little  lathe,  as  shown  in  ^g.  1011,  he  turns  them  briskly 
round,  giving  the  points  a  bluish  cast,  while  he  polishes  and  improves  them.  This  partiiJ 
polish  is  in  the  direction  of  the  axis ;  that  of  the  rest  of  the  needle  is  transverse,  which 
distinguishes  the  boundaries  of  the  two.  The  little  hone-stone  is  not  cylindrical,  but 
quadrangular,  so  that  it  strikes  successive  blows  with  its  comers  upon  the  needles  as  it 
revolves,  producing  the  eflfect  of  filing  lengthwise.  Whenever  these  angles  seem  to  be 
blunted,  they  are  set  again  by  the  bluer. 

It  is  easy  to  distinguish  good  English  needles  from  spurious  imitations ;  because  tbe 
former  have  their  axis  coincident  with  their  points,  which  is  readily  observed  by  tumiaf 
them  round  between  the  finger  and  thumb. 

The  construction  of  a  needle  requires,  as  already  stated,  about  120  operations ;  but 
they  are  rapidly  and  uninterruptedly  successive.  A  child  can  trim  the  eyes  of  4000 
aeedles  per  hour. 

When  we  survey  a  manufacture  of  this  kind,  we  cannot  fail  to  observe,  that  the  diver- 
sity  of  operations  which  the  needles  undergo  bears  the  impress  of  great  mechanical  refine- 
ment. In  the  arts,  to  divide  labor,  is  to  abridge  it ;  to  multiply  operations,  is  to  simplify 
them ;  and  to  attach  an  operative  exclusively  to  one  process,  is  to  render  him  much  more 
economical  and  productive. 


264 


NICKEL. 


NEROLI  is  the  name  given  by  perfumers  to  the  essential  oil  of  orange  (lowers.  It  is 
procured  by  distillation  with  water,  in  the  same  way  as  the  other  volatile  oils.  Since  in 
distilling  water  from  neroli,  an  aroma  is  obtained  different  from  that  of  the  orange-flower, 
it  has  been  concluded  that  the  distilled  water  of  orange-flowers  owes  its  scent  to  some 
principle  different  from  ah  essential  oil. 

NET  (Filet J  reseau,  Fr. ;  Netz,  Germ.)  is  a  textile  fabric  of  knotted  meshes,  for 
catching  fish,  and  other  purposes.  Each  mesh  should  be  so  secured  as  to  be  incapable  of 
enlargement  or  diminution.  The  French  government  offered  in  1802  a  prize  of  10,000 
francs  to  the  person  who  should  invent  a  machine  for  making  nets  upon  automatic 
principles,  and  adjudged  it  to  M.  Buron,  who  presented  his  mechanical  invention  to  the 
Conserviiioire  des  Jrts  et  Metiers.  It  does  not  appear,  however,  that  this  machine  has 
accomplished  the  object  in  view  ;  for  no  establishment  was  ever  mounted  to  carry  it  into 
execution.  Nets  are  usually  made  by  the  fishermen  and  their  families  during  periods  of 
leisure.  The  formation  of  a  mesh  is  too  simple  a  matter  to  require  description  in  this 
Dictionary. 

NEUTRALIZATION  is  the  state  produced  when  acid  and  alkaline  matters  are  com- 
bined in  such  proportions  that  neither  predominates,  as  evinced  by  the  color  of  tincture 
of  litmus  and  cabbage  remaining  unaffected  by  the  combination. 

NICARAGUA  WOOD  is  the  wood  of  the  Caaalpinia  echinata,  a  tree  which  grows  in 
Nicaraca.  It  is  used  with  solution  of  tin  as  a  mordant  to  dye  a  bright  but  fugitive  red. 
It  is  an  inferior  sort  of  Brazil  wood. 

NICKEL  is  a  metal  rather  sparingly  found,  and  in  few  localities ;  being  usually  asso- 
ciated with  cobalt.  Native  nickel  occurs  at  Westerwald  in  the  Erzegebirge,  in  Bohemia, 
combined  with  arsenic,  under  the  significant  name  of  Kupfemirkel ;  with  cobalt,  iron,  and 
copper,  as  .Arsenic-nickel,  in  theHarz  ;  at  Riechelsdorf  in  Hessia;  as  an  oxyde,  in  NickeU 
schwartze  ;  as  a  sulphuret  of  nickel  in  Haarkies  ;  as  a  sulphuret  and  arseniate  of  nickel 
in  Nickel glanz ;  and  with  sulphur  and  antimony  in  Nickehpiess  glanzerz  at  Siegen. 
Nickel  is  always  present  in  meteoric  stones.  Kupfernickel  occurs  in  numerous  external 
shapes;  as  reniform,  globular,  botroidal,  arborescent,  massive,  and  disseminated;  fracture, 
coarse  or  fine  grained,  with  metallic  lustre ;  color,  copper  red,  occasionally  brown  and 
gray ;  in  silver  and  cobalt  veins,  in  gneiss,  sienite,  mica-slate,  kupfer-schiefer,  accompa- 
nied by  speisse  cobalt,  native  silver,  quartz,  &c.  It  is  found  in  Westphalia  near  Olpe,  in 
Hessia  at  Riechelsdorf,  and  Biber,  in  Baden ;  in  the  Saxon  Erzegebirge  near  Schneeberg, 
and  Freiberg ;  in  Bohemia,  at  Joachimsthal ;  in  Thuringia,  at  Saalfeld ;  in  Steyermark 
near  Schladming;  in  Hungary,  France,  and  England. 

Since  the  manufacture  of  German  silver,  or  JrgerUane,  became  an  object  of  commercial 
importance,  the  extraction  of  nickel  ha*-  been  undertaken  upon  a  considerable  scale.  TJie 
cobalt  ores  are  its  most  fruitful  sources,  and  they  are  now  treated  by  the  method  of 
Wohler,  to  effect  the  separation  of  the  two  metals.  The  arsenic  is  expelled  by  roasting 
the  powdered  speise,  first  by  itself,  next  with  the  addition  of  charcoal  powder,  till  the  garlic 
smell  be  no  longer  perceived.  The  residuum  is  to  be  mixed  with  three  parts  of  sulphur 
and  one  of  potash,  melted  in  a  crucible  with  a  gentle  heat,  and  the  product  being  edul- 
corated with  water,  leaves  a  powder  of  metallic  lustre,  which  is  a  sulphuret  of  nickel 
free  from  arsenic ;  while  the  arsenic  associated  with  the  sulphur,  and  combined  with  the 
resulting  sulphuret  of  potassium,  remains  dissolved.  Should  any  arsenic  still  be  found 
in  the  sulphuret,  as  may  happen  if  the  first  roasting  heat  was  too  great,  the  above  pro- 
cess  must  be  repeated.  The  sulphuret  must  be  finally  washed,  dissolved  in  concentrated 
sulpnuric  acid,  with  the  addition  of  a  little  nitric,  the  metal  must  be  precipitated  by  a 
carbonated  alkali,  and  the  carbonate  reduced  with  charcoal. 

In  operating  upon  kupfernickel,  or  speise,  in  which  nickel  predominates,  after  thfc 
arsenic,  iron,  and  copper  have  been  separated,  ammonia  is  to  be  digested  upon  the  mixed 
oxydes  of  cobalt  and  nickel,  which  will  dissolve  them  into  a  blue  liquor.  This  being 
diluted  with  distilled  water  deprived  of  its  air  by  boiling,  is  to  be  decomposed  by  caustic 
potash,  till  the  blue  color  disappears,  when  the  whole  is  to  be  put  into  a  bottle  tightly 
stoppered,  and  set  aside  to  settle.  The  green  precipitate  of  oxyde  of  nickel,  which  slowly 
forms,  being  freed  by  decantation  from  the  supernatant  red  solution  of  oxyde  of  cobalt,  is 
to  be  edulcorated  and  reduced  to  the  metallic  state  in  a  crucible  containing  crown  glass. 
Pure  nickel  in  the  form  of  a  metallic  powder  is  readily  obtained  by  exposing  its  oxalate 
to  modern  ignition. 

The  reduction  of  the  oxyde  of  nickel  with  chai  coal  requires  the  heat  of  a  powerful  air 
furnace  or  smith's  forge. 

Nickel  possesses  a  fine  silver  white  color  and  lustre ;  it  is  hard,  but  malleable,  both 
hot  and  cold ;  may  be  drawn  into  wire  J^  of  an  inch,  and  rolled  into  plates  .-1_  of  an 
inch  thick.  A  small  quantity  of  arsenic  destroys  its  ductility.  When  fused  it  has  a 
specific  gravity  of  8-279,  and  when  hammered,  of  8-66  or  8-82 ;  it  is  susceptible  of  mag- 
netism, in  a  somewhat  inferior  degree  to  iron,  but  superior  to  cobalt.  Mariners'  com- 
passes may  be  made  of  it.  Its  melting  point  is  nearly  as  high  as  that  of  manganese.  It 
is  not  oxidized  by  contact  of  air,  but  may  be  burned  in  oxygen  gas. 


t 


NICKEL. 

There  is  one  oxide  and  two  suroxides  of  nickel.  The  oxide  is  of  an  ash-graj  color, 
and  is  obtained  by  precipitation  with  an  alkali  from  the  solution  of  the  muriate  or  ni- 
trate. The  niceolous  suioxide  of  Berzelius  is  black,  and  may  be  procured  by  exposing 
the  nitrate  to  a  heat  under  redness.  The  niceolic  suroxide  has  a  dirty  pale  green  co- 
lor; but  its  identity  h  doubtful. 

Nickel  may  be  detected  by  cyanide  of  potassium  in  an  acid  solution  of  it  and  cobalt; 
the  cyanide  being  added  until  the  precipitate  first  formed  is  redissolved:  dilute  sul- 
phuric acid  is  then  added,  and  the  mixture  warmed  and  allowed  to  stand.  A  precipi- 
tate appearing  shows  the  presence  of  nickel,  whether  it  be  cobalt  cyanide,  or  simple 
cyanide  of  nickel. 

Nickel  {analyses  of),  by  H.  Rose.  Nickel  and  cobalt  are  almost  always  associated  to- 
gether, and  are  very  difficult  to  separate. 

Upon  the  fact  that  in  a  solution  of  oxide  of  cobalt  containing  free  muriatic  acid,  the 
whole  of  the  metal  is  converted  into  the  superoxide,  by  means  of  chlorine,  while'  the 
chloride  of  nickel  remains  unaltered  in  the  acid  solution,  Mr.  H.  Rose  based  a  success- 
ful method  for  the  separation  of  the  metals.  His  method  is  as  follows: — Both  metals 
are  dissolved  in  hydrochloric  acid ;  the  solution  must  contain  a  sufficient  excess  of  free 
acid;  it  is  then  diluted  with  much  water;  if  1  or  2  grammes  of  the  oxide  are  operated 
on,  about  2  lbs.  of  water  are  added  to  the  solution.  As  cobalt  possesses  a  much  greater 
coloring  power  than  nickel,  not  only  in  fluxes  but  also  in  solutions,  the  diluted  solution 
is  of  a  rose  color,  even  when  the  quantity  of  nickel  present  greatly  exceeds  that  of  the 
cobalt.  A  current  of  chlorine  gas  is  then  passed  through  the  solution  for  several  hours ; 
the  fluid  must  be  thoroughly  saturated  with  it,  and  the  upper  part  of  the  flask  above 
the  liquid  must  remain  filled  with  the  gas  after  the  current  has  ceased.  Carbonate  of 
baryta  in  excess  is  then  added,  and  the  whole  allowed  to  stand  for  12  or  18  hours,  and 
fre<iuently  agitated.  The  precipitated  superoxide  of  cobalt  and  the  excess  of  carbonate 
of  baryta  are  well  washed  with  cold  water,  and  dissolved  in  hot  hydrochloric  acid; 
after  the  separation  of  the  baryta  by  sulphuric  acid,  the  cobalt  is  precipitated  by  hy- 
drate of  i^otash,  and  after  being  washed  and  dried  is  reduced  in  a  platinum  or  porcelain 
crucible  by  hydrogen  gas.  The  fluid  filtered  from  the  superoxide  of  cobalt  is  of  a  pure 
green  color.  It  is  free  from  any  trace  of  cobalt  After  the  removal  of  the  baryta  by 
means  of  siriphuric  acid,  the  oxide  of  nickel  is  precipitated  by  caustic  potash.  Even  this 
method  did  not  give  exact  results  on  the  first  trial.  0-318  gr.  metallic  nickel  and  0603 
gr.  metallic  cobalt  were  employed,  and  0'130  gr.  oxide  of  nickel  and  OSSOgr.  cobalt 
were  obtained : — 


Nickel 
Cobalt 


Employed. 
34-53 
65-47 

100-00 


Obtained. 
36-75 
6298 

99-73. 


The  cause  of  these  incorrect  results  is,  that  the  solution  was  filtered  an  hour  or  two 
after  the  precipitation  of  the  superoxide  of  cobalt  by  the  carbonate  of  baryta.  It  is  ne- 
cessary, however,  to  wait  a  considerable  time,  at  least  twelve  hours,  or  even  eighteen  is 
better,  and  allow  the  excess  of  carbonate  of  baryta  to  remain  in  contact  with  the  solu- 
tion, as  the  superoxide  of  cobalt  is  precipitated  very  slowly:  this  explains  the  diminu- 
tion of  the  cobalt  and  the  increase  of  the  nickel  in  the  above  experiment 

In  another  experiment,  in  which  this  source  of  error  was  avoided,  0-739  gr.  metallic 
nickel  and  0*540  metallic  cobalt  were  used,  and  0*548  gr.  cobalt  obtained,  that  is42-84 
per  cent  instead  of  42*22 ;  the  nickel  was  not  determined.  Two  experiments  were 
made  by  M.  Weber.  In  one,  0-818  gr.  cobalt,  and  0980  gr.  nickel  were  taken,  and 
0-806  gr.  cobalt  and  1*274  oxide  nickel  obtained. 


Cobalt 
Nickel 


Used. 

45*50 

64-50 

100*00 


Obtained. 
44-77 
65-83 

100-60 


In  the  second  0*516  gr.  metallic  cobalt  and  0.637  oxide  of  nickel  were  taken,  and 
0*617  gr.  cobalt  obtained. 

It  will  be  seen  from  these  experiments,  that  on  the  proper  precautions  being  taken, 
very  accurate  results  may  be  obtained  by  this  method.  It  has  also  this  advantage,  that 
It  IS  equally  applicable  whatever  the  relative  proportions  of  the  cobalt  may  be. 

This  or  a  similar  method  may  be  employed  with  advantage  on  a  large  scale,  to  procure 
cobalt  and  nickel  in  the  purest  state.  Both  metals  are  m(»re  employed  in  the  arts  than 
formerly ;  and  in  many  cases  it  is  important  to  prepare  them  as  pure  as  possible.   Thi» 


266 


NICKEL. 


NICKEL. 


26r 


i.  the  case  when  oxide  of  cobalt  is  to^^-P^Xe'pun?f 

tamed  by  t     I  have  «;J  '^^^  P^  P^  .    ^    experiments  described  above,  none  but  the 

which  are  not  converted  into  superoxides.  Nickel  and  cobalt  ^^^'^  "J^^^i^;^;  ■  ^  ^ 
rat?fLn,eU.s  to  which  they  ^^^^ 

method  in  ray  "Manual  of  Analvtical  ^^^"^'^J^^^J^i  .  chlorides  and  treating  these 
separated  from  manganese,  ^J-' ^v  con^rt^^^^^  J^^  ^^, 

by  hydrogen,  which  reduces  the  %«r^^^\«,^^^^''X^^^  accurate  results,  but  is  rather 
not  the  chloride  of  manganese,  i*"^  °"f ''''.**^  ^T.^  ^f  ronir  heat  the  chloride  of  man- 
complicated.  Volker  has  remarked  that  ft*ver>  strong  ^«at  ^^^^^^^^  ^^^  ^^^^  ^a* 
.ane'se  is  ^^'f^ly  volatile.     Alt^^^^^^^^^^  ,hods 

been  raised  too  high,  still  it  is  possiDie  xo  ^f'*'^^  '  \     ,/  ,,    -  .i^    method  of  Barresvil 

S.e  oxide  of  manganese,  will  be  P'-'^'P'  ^'''^  "' »  "^"tt  same  manner  as  cob.lt,  a. 

From  nickel,  the  manganese  may  be  ^^^t  scpaiated  n  the  «»"« J*^       howeverVby 

I  have  remarked  above.    Mansanese  may  be  »«P»™*f'l  f^^f'^^X     j^^^^  „'p„i 

.  method  which,  in  its  essential  parts,  was  P^^P"'^"! '^Jj^^JJ^^^h         oSns'by 

Xiii^^^d^lSir^ia^^rhrtw 
srfio%''^:rKrcS^ 

attention  to  th.s  curious  property  and  made  us^^^^^^^^  ^P^^^  ^^^^  ^^.^^ 

acid  reaction ;  the  sulphurets  oi  nickei  aim  c  /^  ,  ^  hvdrochlor  c  acid, 

with  water  containing  a  I'^tle  sulphuretted  hyd.ogen  and  a  tj^«^«*  '^J  .^  ^^^^^^^ 

The  sulphuret  of  manganese  is  f «;,  ^f.^  J^^^ /^^^^^^^^  drtV  flesh-colored  precipi- 

from  the  sulphurets  of  nickel  and  cobalt  gives  <>^ly^^^^^^^^^       ^^^  ^j^^  sulphuret  of 
tate  on  the  addition  of  ammonia  ^^^^  ^jf  ^«"JP^^^^^  there- 

manganese  contains  «™all  Portions  of  sulphur^^^^^^^^  nicked     a^     ^^^^^^  ^^  ^^^ 

forett  is  treated  anew  with  very  dilute  .^^^J^^^;^^*^.  ^''^ment  a  very  nearly  correct 
black  sulphurets  remain  b«hmd     By  this  repeated  tre^^^^^^^^ 

manner,|ave  0-214  of^^-^-^tt^ntkef  "and  i:  t^^tT  frL  cobalt,  in  the  same 
Iron  also  may  be  «<'P»r***«,,\™"  "'^f  V*^  ufce  sulphuret  of  manganese,  is  eas.Iv 

roSTi-irv^jehTdro^o^^^ 

"IccUcti/is  malTJo  tt  .olution,  especially  if  the  latter  oxides  are  present 


From  alumina  oxide  of  nickel  may  be  separated  by  fusing  them  together  with  hydrate 
of  potash  in  a  silver  crucible ;  on  treating  the  fused  mass  with  water,  the  oxide  of  nickel 
remains  behind  in  a  dense  state.  It  weighs  nither  more  than  the  oxide  emploved,  but 
contains  no  alumina,  and  potash  must  therefore  be  present  0-238  gr.  oxide  of  nickel 
mixed  with  alumina  weighed,  after  it  had  been  treated  in  this  manner,  0*245  gr.  By 
boiling  with  a  solution  of  potash,  nickel  cannot  be  separated  from  alumina,  when  botk 
are  contained  in  a  solution,  not  even  when  the  treatment  is  repeated.  When  the  0-246 
gr.  was  dissolved  in  hydrochloric  acid  with  the  help  of  a  little  sulphuric  acid,  and  the 
separated  solution  of  alumina  in  potash,  to  which  more  potash  was  added,  mixe*!  witk 
the  solution,  and  the  whole  boifed,  the  oxide  of  nickel  separated  weighed  O"  320  gr. 
When  this  was  dissolved  in  hydrochloric  acid,  a  considerable  quantity  of  alumina 
separated  on  the  addition  of  ammonia  in  excess.  As,  however,  the  fusion  of  hydrate 
of  potash  in  a  silver  crucible  is  attended  with  inconvenience,  and  the  oxide  of  nickel 
obtained  requires  to  be  dissolved  and  precipitated  anew,  the  separation  of  these  oxides 
by  means  of  carbonate  of  baryta  is  preferable. 

I  have  tried  in  vain,  by  fusing  with  a  fixed  alkaline  carbonate,  to  separate  quantita- 
tively alumina  from  the  oxides  of  cobalt  and  nickel,  and  from  those  of  other  metals 
which  are  incapable  of  expelling  the  carbonic  acid  from  an  alkaline  carbonate  at  aa 
elevated  temperature.  It  is  difficult  to  obtain  a  perfectly  cl^r  solution  by  fusing  alu- 
mina with  carbonated  alkali,  and  treating  the  melted  mass  with  water ;  it  is  quickly 
rendered  turbid  by  the  carbonic  acid  of  the  atmosphere.  A  fused  mass  is  much  moi-e 
easily  obtained  with  carbonate  of  soda  than  with  carbonate  of  potash. 

Nickel  and  6'o6a/^— Mingled  with  the  beautiful  samples  of  copper  pyrites  and  argen- 
tiferous galena  displayed  in  Class  1.  of  the  Groat  Exhibition,  there  were  to  be  found 
several  specimens  of  cobalt  and  nickel  ores.   These  valuable  articles  lay  buried  beneath 
the  huge  bulk  of  their  better  known  compeers,  and,  unless  sought  for,  would  fail  to  arrest 
the  attention  even  of  a  scientific  observer ;  thus  singularly  illustrating  in  the  Crystal 
Palace  the  obscure  position  they  occupy  in  the  manufacturing  industry  of  the  nation. 
The  art  of  working  the  ores  of  cobalt  and  nickel  seems  unknown  in  Great  Britain,  if 
we  may  judge  by  the  fact,  that  though  found  in  sufficient  abundance,  they  are  nowhere 
in  this  country  converted  into  zatfre  and  speiss,  the  two  primary  marketable  producU 
elsewhere  obtained  from  these  ores.     Although,  therefore,  no  nation  in  the  world  con- 
sumes in  Its  manufactures  more  cobalt  and  nickel  than  Great  Britain,  yet  for  these 
metals  it  is  entirely  dependent  upon  Norwa}',  Northern  Germany  and  the  Netherlands- 
from  whence  we  import  annually  not  less  than  400  tons  of  zaffre  and  smalts,  and  ue.Hrly 
the  same  quantity  of  nickel  and  speis.^  to  the  conjoint  value  of  about  150,00u/.  sterling. 
£^  these  substances  serve  very  different  purposes  in  the  aits,  we  propose  to  speak  of 
them  separately,— merely  premising  that  cobalt  forms  the  bases  of  all  the  blue  colors 
seen  on  earthenware,  whilst  nickel  is  an  indispensable  ingredient  in  the  various  metallic 
alloys,  known  under  the  terms  albata,  German  silver,  Ac.  The  specimens  of  ore  previously 
alluded  to  as  existing  in  the  Great  Exhibition  have  been  derived  from  Cornwall,  and 
contain,  as  is  generally  the  case,  both  nickel  and  cobalt,  thus  far  being  precisely  similar 
to  the  ores  worked  in  Norway  and  Northern  Germany.     The  foreign  ores  are,  however, 
much  richer  than  the  Cornish,  since  these  latter  seldom  contain  more  than'from  2  to 
7  per  cent,  of  available  metallic  matter,  whilst  the  former  not  unfrequently  yield  12 
or  15  per  cent. ;  consequently,  a  process  which  answers  quite  well  with  the  one  may 
fail  altogether,  or  prove  profatless  with  the  other;  and  this  is  exactly  the  whole  secret 
of  our  national  failuie  in  working  cobalt  ore.     The  Swedish  method  has  been  tried  in 
several  parts  of  Cornwall,  and  has  not  in  any  one  instance  given  a  satisfactory  result  • 
hence,  the  Crystal  Palace  contains  no  specimen  of  British  zaffre,  and  our  potteries,  glass 
works,  and  paper  manufacturers  procure  from  abroad  that  which  ignorance  and  apathy 
deny  them  at  home.     In  the  German  ore  the  quantity  of  metallic  ingredients  is  not 
only  larger  than  in  the  Cornish,  but  also  of  a  more  fusible  character ;  consequently  when 
simply  subjected  to  heat  in  a  reverberatory  furnace,  the  earthy  and  metallic  elements 
separate  of  themselves  by  the  mere  disparity  of  their  specific  weights  ;  and  the  silicious 
gangue,  with  a  portion  of  oxide  of  iron,  rises  to  the  top;  leaving  a  metallic  compound 
of  arsenic,  cobalt  nickel,  copper,  and  perhaps  iron  beneath.     This  latter,  when  carefully 
roasted  m  an  oxidizing  furnace,  in  contact  with  sand  or  ground  flint,  aflFords  at  once 
an  impare  silicate  of  cobalt  and  arseniuret  of  nickel,—two  marketable  products.     The 
llT'!f  Tf '  ^v"^  ^^'"^  metallic  poverty,  will  not  undergo  the  first  fusion  necessary  to 
Jn^K  „  v!  1       «^^|f  ^^«*  "'^t"^  of  the  mineral ;  and  this  triflhig  impediment  seems  actuilly 
L  inT  *J^"".™^®*?  *•;?  «"^rgy  of  that  indomitable  spirit  of  enterprise  for  which  Britaii 
rlnl  ?K      r^-  J«««y  ce  ebrated.     In  the  manufacture  of  iron,  limestone  is  used  to 

Inrfn  kI  !k  ^°!J"''  ^'"'^  '''•'*  ^^  ^^^  «^«  f»«ibl«  J  ^^^  without  this  DO  irou  Can  be  pro. 
In  n!;n^^.        ordinary  process.     In  roasting  lead  ore,  lime  cannot  be  dispensed  with. 

inmmT   /"* K ",?'  ""^^^  T^^  ^'"^  ^"^  «^«^  fl^^i-  «Pa^  is  frequeiftly  needed ;  and  the 
commonest  cobalt  ores  of  Cornwall  clearly  require  nothing  but  a  proper  flui  to  aflford 


^1 


268 


NICKEL. 


a  compound  of  arsenic,  cobalt  and  nickel,  perfectly  analogous  to  that  procured  from 
the  German  ore  by  mere  fusion  without  a  flux.  The  whole  question,  therefore,  really 
resolves  itself  into  the  discovery  of  a  cheap  material  capable  of  easy  vitrification  with 
the  granitic  matrix  of  the  Cornwall  ore,  and  which  is  nevertheless  devoid  of  action 
upon  the  arseniuret  of  cobalt  and  nickel.  The  common  fixed  alkalis,  though  answer- 
ing the  fiist  indication  admirably,  would  not  comply  with  the  second  condition ;  hence 
potash  and  soda,  these  great  helpmates  of  industrial  skill,  are  unfortunately  excluded 
from  the  list  of  agents,  as  they  act  powerfully  upon  all  the  arseniurets,  and  would 
merely  produce  a  worthless  frit  with  the  ore.  Similar  objections  attach  more  or  leee 
to  the  alkaline  earths,  and  therefore  lime  requires  to  be  looked  upon  with  suspicion. 
Borax  would  and  does  yield  a  satisfactory  result,  but  its  high  price  is  an  insurmount^ 
able  obstacle.  Fluor  spar  is  of  no  avail,  and  bottle  glass  requires  too  strong  a  tem- 
perature, and  to  be  used  in  too  great  a  quantity,  for  economical  application  to  a  mine- 
ral already  suicharged  with  extraneous  matters. 

These  facts  serve  in  some  measure  to  explain,  though  we  cannot  in  any  way  allow 
that  they  justify,  the  present  condition  of  the  zafFre  market ;  since  these  very  difficulties 
are  daily  overcome  in  one  of  the  largest  metallurgical  operations  carried  on  amongst  us. 
Many  of  the  ores  of  copper,  when  fii-st  received  by  the  manufacturer,  are  in  a  state 
quite  parallel  to  that  of  the  Cornish  ores  of  cobalt,  even  in  regard  to  poverty  of  metaL 
There  is  the  same  excess  of  granitic  matrix,  the  same  necessity  for  avoiding  the  use  of 
any  agent  capable  of  attacking  sulphuret  of  copper,  a  substance  possessing  very  similar 
chemical  affinities  to  those  of  the  arseniurets  of  nickel  and  cobalt  What  then  is  the 
flux  employed  by  the  copper  manufacturer  in  such  cases?  We  reply  at  once, — it  is  the 
protoxide  of  iron  which  is  formed  from  these  poor  copper  ores  by  the  action  of  heat, 
and  combines  with  the  silicate  of  the  matrix  so  as  to  produce  an  extremely  fusible 
silicate  of  iron,  which  permits  the  sulphuret  of  copper  to  fall  down  to  the  lower  part  of 
the  reverberatory  furnace,  whilst  the  vitrified  impurities  of  the  ore  are  raked  from  its 
surface.  Oxide  of  iron  would  most  probably  therefore  enable  a  manufacturer, 
accustomed  to  furnace  operations,  to  send  into  the  market  an  arsenical  compound  of 
cobalt  containing  more  than  60  per  cent,  of  this  metal,  even  if  his  interest  failed  to 
convince  him  of  the  great  advantage  resulting  from  its  subsequent  conversion  into 
zaffre.  Thus,  then,  the  conditions  of  this  seemingly  difficult  problem  are  answered,  in  a 
commercial  sense ;  for  oxide  of  iron  is  plentiful  and  cheap,  its  combination  with  silica 
is  sufficiently  fusible,  and  it  has  no  action  whatever  upon  metallic  arseniurets.  No 
doubt  many  other  substances  might  be  found  equally  applicable  with  the  one  we  have 
mentioned;  and,  indeed,  our  object  in  thus  dilating  upon  this  and  analogous  topics  is 
rather  to  stimulate  inquiry  than  to  lay  down  specific  rules  for  practical  guidance  ;  conse- 
quently our  remarks  must  be  regarded  at  best  as  but  a  shadowy  outline,  the  manu- 
facturing details  of  which  require  careful  filling  in,  to  render  the  whole  intelligible  and 
useful. 

Before  quiting  the  subject  of  cobalt,  it  may  be  as  well  to  advert  to  a  particular  ore 
of  that  metal,  found  near  Keswick  in  Cumberland.  This  ore  contains  from  two  to  three 
per  cent  of  cobalt,  but  is  quite  free  from  nickel, — a  very  unusual  circumstance, — as  even 
in  meteoric  stones  cobalt  iri  constantly  accompanied  by  nickel,  though  this  last  metal 
not  unfrequently  exists  without  cobalt  As  a  coloring  material,  oxide  of  cobalt  is 
seriously  damaged  by  the  presence  of  oxide  of  nickel,  for  these  oxides  produce  colors 
almost  complementary  to  each  other ;  and  therefore  tending,  by  their  admixture,to  yield 
a  neutral  tint,  as  is  observable  when  their  saline  solutions  are  united.  The  great  ad- 
vantage of  working  an  ore  of  cobalt  free  from  nickel  must  consequently  be  obvious  to 
all.  The  Keswick  mine  is,  nevertheless,  almost  abandoned  at  the  present  moment, 
through  sheer  inability  to  find  a  market  for  its  produce  ;  though  for  tl.e  finer  kinds 
of  porcelain  and  for  enamel  painting,  the  oxide  of  cobalt  procured  from  it  is  worth 
fully  a  guinea  per  pound. 

In  the  hope  of  drawing  attention  to  a  raw  material  at  once  so  unique  and  valuable, 
we  give  the  following  original  process  for  extracting  pure  oxide  of  cobalt  from  the 
Keswick  cobalt  ore : — Having  carefully  roasted  a  quantity  of  this  ore,  at  a  full  red  heat, 
in  a  muffle  furnace,  for  two  or  three  hours,  it  is  next  to  be  reduced  to  a  fine  powder, 
and  then  digested  in  muriatic  acid  of  the  specific  gravity  110  or  thereabout  And  for 
this  use  the  waste  acid  of  the  soda  maker  is  well  adapted,  even  though  it  may  happen 
to  contain  arsenic  and  iron.  After  a  few  hours'  digestion,  the  acidulous  solution  may 
be  poured  otf  and  a  fresh  acid  added,  so  as  completely  to  exhaust  the  roasted  ore,  and, 
dissolve  all  the  metallic  matter  in  it  Then  mix  the  solution  thus  procured :  and 
having  thown  in  a  portio-n-  of  powdered  htematitc  or  other  form  of  peroxide  of  iron, 
evaporate  the  whole  to  dryness.  Next  pour  boiling  water  on  the  dried  mass,  and 
stir  in  an  excess  of  chalk,  or  finely  powdered  marble,  and  preserve  the  whole  at  a 
temperature  of  abou»  18<)°  Fiihr,  until  all  evolution  of  carbonic  acid  ceases;  then  add 
a  quantity  of  suiphate  of  soda,  and  thiow  the  mixtuie  on  a  filter,  when  asolutionof  chlo- 


NITRATE  OF  AMMONIA. 


269 


nde  of  cobalt  will  pass' through,  containing  a  small  quantity  of  the  sulphates  of  lime 
and  soda,   but  altogether  free  from  metallic  contamination.     This  solution  must  now 
be  super-saturated  with  a  caustic  lye  of  soda,  and  the  mixture  boiled  for  a  few  minute- 
in  order  to  insure  the  rapid  precipitation  of  the  oxide  of  cobalt;  which,  after  careful 
•washing  with  hot  water,  is  to  be  dried,  and  heated  red  hot,  in  a  crucible,  to  give  it  the 
character  suitable  for  the  English  market     One  pound  of  Keswick  ore  will  require 
about  8  ounces  of  muriatic  acid,  of  the  kind  alluded  to,  with  2  ounces  of  haematite,  3 
ounces  of  chalk,  and  the  same  quantity  of  salt  cake  or  dry  sulphate  of  soda.     The  ex- 
planation of  this  process  is  very  simple:  in  the  first  instance,  the  metallic  matters  of 
the  ore,  consistmg  of  iron,  cobalt  arsenic,  copper,   and  perhaps  also  lead,  are  dissolv- 
ed by  the  muriatic  acid ;  and,   as  all  of  these  are  precipitated  by  carbonate  of  lime, 
except  cobalt,  the  chalk  might  now  be  added  at  once,  but  for  the  fact  that  the  Kes- 
wick ore  contains  an  excess  of  arsenic,  which  carries  down  a  portion  of  cobalt  in  the 
state  of  arsenite  of  cobalt     To  remedy  this  evil,  peroxide  of  iron  or  ha;matite  must  be 
added,  so  as  to  ensure  the  existence  of  an  excess  of  peroxide  of  iron  in  the  solution ;  as 
this,  on  the  introduction  of  the  chalk,  will  unite  to  the  arsenic,  and  thus  prevent  the 
precipitation  of  any  cobalt  at  this  stage  of  the  operation.     The  cessation  of  all  eflferves- 
cence,  indicates  tliat  the  chalk  has  ceased  to  act,  and  that  the  iron,  arsenic,  copper  and 
lead  are  no  longer  in  solution,  but  have  been  displaced  by  the  lime  of  the  chalk.'  To 
remove  this  lime,  6uli)hate  of  soda  is  employed,  since  this  throws  down  nearly  the  whole 
ot  the  hme  in  the  state  of  sulphate;  after  which  caustic  soda  or  potash  will  precipitate 
nothing  from  the  filtered   solution  but  pure  oxide  of  cobalt     Although  apparently 
somewhat  complex  in  detail,  this  process  is  extremely  simple  and  efficient  in  practice  • 
and  possesses,  moreover,  the  advantage  of  being  equally  applicable  to  the  treatment  of 
speiss  or  arseniuret  of  nickel,  from  which  pure  oxide  of  nickel  may  be  easily  procured, 
—using,   however,  much  more  haematite  than  the  quantity  above  indicated,  in  conse- 
quence  of  the  absence  of  iron  in  speiss.     From  this  latter  circumstance,  it  must  be  ob- 
vious, that  cobalt  and  nickel  cannot  be  separated  in  the  way  just  described;  for,  as  has 
been  stated,  they  both  remain  in  solution  after  the  employment  of  the  chalk;  and,  in- 
deed, no  process  has  yet  been  published  by  which  a  perfect  separation  of  these  two  met- 
als  can  be  effected.    Ordinary  Swedish  zaffre  contains,  on  an  average,  15  per  cent  of 
oxide  of  cobalt    mixed  with  about  3  per  cent  of  oxide  of  nickel ;  which  latter  seri- 
ously impairs  the  coloring  power  of  zaffre.     Hence  it  is  that  we  have  entered  thus  fully 
into  this  question;  for  as  it  is  almost  impossible  to  purify  cobalt  when  contaminated 
with  nickel.  It  18  a  kind  of  national  disgrace  to  Great  Britain  that,  having  a  pure  ore 
ot  cobalt  in  the  very  centre  of  the  island,  our  manufactures  are  unable  either  to  com- 

**  vTn^-rr  JU'l-S"^^  *^  ^^°^^^^  ^^^*  ^^®  P^^^^  <^^  superiority  in  the  formation  of  zaffre. 

JNlOOllANliSE,  is  the  name  of  an  oil  recently  extracted  from  the  leaves  of  tobac- 
co, which  possesses  the  smell  of  tobacco  smoke. 

NICOTINE,  is  a  peculiar  principle,  obtainable  from  the  leaves  and  seeds  of  tobacco 
{ntcottana  tabacufn),  by  infusing  them  in  acidulous  water,  evaporating  the  infusion  to 
a  certain  point,  adding  lime  to  it,  distilling,  and  treating  the  product  which  comes  over 
J^oVi  *  •  ^^  colorless,  has  an  acrimonious  taste,  a  pungent  smell,  remains  liquid  at 
•f  K  m'  ^^^l^^  »1^  proportions  with  water,  but  is  in  a  great  measure  separable  from 
It  by  ether,  which  dissolves  it  abundantly.  It  combines  with  acids,  and  forms  salts 
acrid  and  pungent  hke  itself;  the  phosphate,  oxalate,  and  tartrate  being  crystallizable. 
Nicotine  causes  the  pupils  to  contract     A  single  drop  of  it  is  sufficient  to  kill  a  dog. 

Macerate  powdered  tobacco  for  twenty-four  hours  in  water  acidulated  with  sulphu- 
?1  w^h!  ^^''P^^^  ^\^  l^q»o>-.  evaporate  to  the  consistence  of  syrup,  and  distil  the  resi- 
?»U  !  sufficient  quantity  of  potash  ;  add  more  water  from  time  to  time  to  prevent 
centraLd^TrZfK-  ^^a-  ^j^^^"^  ^^  consequence  of  the  potash  being  too  much  con- 
Tin  fhr...-''"'  this  distillation  a  Quantity  of  nicotina  and  ammonia  will  be  obtain- 
f«  TJutl  JT'  ^''^i  ^^'''•'^  *^^  *^  ^«  neutralized  with  oxalic  acid.  Evaporate  now 
nf  nSma  Z     '''^'i^'  ""^^^"^  ^^^^  boiling  alcohol,  which  will  dissolve  the  oxalat^ 

tLT sXt  o'^of'^no?'  r  ^^'^  "^  """^"'^^'^  "°^^^^^  "P«°-     H^^t  '^'  o--J-t«  of  nil 
ble  and  from  whL^^^^  separate  the  nicotina  with  ether,  in  which  it  is  solu- 

M  ArH^To         •  Z^^^^^'^^^^y  *S*^"  ^e  separated  by  distillation, 
of  wa^te?rd^7"atoLV''^  "^^^^^^  ^^^  *^  be  "perfectly^re.  but  to  contain  a  porUon 

rid^eT^f  Ikt^nuifand  ^^    '"^'  ^Z^'^  ^^  '^'  combination  of  nicotina  with  the  chlo- 
r4rM?S;;^  -P-nted  the  composition  of  this 

Cio  =  73-26 
Hs  =     9-65 

NITRATE  OF  AMMONIA,   i,  p«'p;.r7d "by" neutralizing  nitric  acid  with  ««. 


270 


NITRATE  OF  POTASH. 


feiing^g^™''"''*  """^  crystallizing  the  solution.     Heat  converts  it  into  water  and 

nitrate' OF  LEAD  {Nitrate  de  plomb,  Fr. ;  Salpetersaures  hleioxvd  GernLV  is 
made  by  saturating  somewhat  dilute  nitric  acid^ith  o'Lide  oHeld  htharie  Wo;at- 
ng  the  neutral  solution  t.U  a  pellicle  appears,  and  then  exposing  it  in  aTotch^^^^^^^ 
till  It  be  converted  mto  crystals,  which  are  sometimes  transparent,  but  generallvopaaue 
white  octahedrons  The.r  spec.  grav.  is  4068 ;  they  have  a  coolinrs^weeUsh Vu^^^^^^^^^ 
taste.  They  dissolve  in  7  parts  of  cold,  and  in  much  less  boiling  wLtertheV^u^e^^^^^^ 
moderate  elevation  of  temperature,  emit  oxygen  ^as,  and  pas^slntr'oide  of  lead 
Their  constituents  are  67-3  oxide  and  327  aciX  NTtrate  of  lead  is  mLnmployed  in 
the  chrome  yellow  style  of  Calico  printing  ;  which  see  employ ea  in 

There  are  three  other  compounds  of  nitric  acid  and  lead  oxide-  viz.   the  bi-basic 
1  oVadd""'  "^  '''  ''•^^"'  "^'^^  ^^"^^"  respectively  2%"nd'6  atoms  of  i^^^^^^ 

ili™^J?  TMs'^^'lf ""'  ""'''%  "''^^^"-  J^*'^^'^  ^  ^^'--'  F-  '  Salpetersaure. 
maris  Si  L^  .  w  T^^'f  ?**'^^  ^  ^?  efflorescence  upon  limestones,  sandstones. 
ZI  nf  fhi  '  j^^l^*"^!^;  l\  f«^ms  a  salme  crust  in  caverns,  as  also  upon  the  s,?- 

decomDosed  ^Cw  "^  "'''"•".  P' r'^  "'P^^'""^  ^^^^«  *'"">«!  "^«"«-  ^^^^e  been 
decomposed     Such  caverns  exist  in  Germany  near  Homburg  (Burkardush)  •  in  Aoulia 

XI  ?9  ^f^''^'  '""  ^^"^"  ^'  ^^"^^"*)'  ^^  ^-^"^^J  i"^  t^e  East  Ind's  'in  Ce??on! 
where  22  nitriferous  caverns  a.-e  mentioned ;  in  JVorth  America,  at  Crooked  rW 

l^lnTZ'^  m"^^^'  *^^  ^P^"  '\l  ^^^^^^"""'  ^°  ^^^^^''  Teneriff;  and  AfricT  S 
occurs  as  an  efflorescence  upon  the  ground  in  Arragon.  Hungary.  Podolia.  Sicily 

^a?ts\!S  f  tr/'  ^^^^«V^T^r'  1^^^^'^  America.%nd  Sou?h  ^mencr  Se veS 
plants  contain  saltpetre  ;  particularly  borage,  dill,  tobacco,  sunflowers,  stalks  of  maizt 
Btences         ^^     ""  Parietaria,  &c.     It  has  not  hitherto  been  found  in  anima"su£ 

«nJfo^  question  has  been  frequently  put;  how  is  nitre  annually  reproduced  upon  the 
surface  of  limestones  and  the  ground,  after  it  has  been  removed  b/washingf  T  h*^ 
the  ox?le„'"nr/h ^'  that  as  secondary  limestones  contain  remains^of  anim!l  ma  te^ 

bine  w  if  their  n.nrlT'?*'"'"'  f '°'^'^,  ^"  r''""^  ^f  '^^  I^«^«"^  ^^^"^t"^^»  ^'^^  com! 
TZI'  *  •    .u   ^"^  ^""""J  "'^""^  ^*''*'5  ^^'^"^^  "^trate  of  lime  will  resu  t.     Where 

potash  IS  present  m  the  ground,  a  nitrate  of  that  base  wijl  be  next  formed.     The  generation 

Sn  fl  rtV  '"  !!"  T^u  ^"^'^^  '^  *  ^"^y  '"^^"  ^^^^«^^^  ^^«"^  ^he  surface  of  porous  stones^ 
no  further,  indeed,  than  where  atmospherical  air  and  moisture  can  penetr^e:  and  none 
IS  ever  produced  upon  the  surface  of  compact  stones,  such  as  marble  and  quartz  or  Sf 
argillaceous  minerals.     Dr.  John  Davy  and  M.  Longchamp  have  advanced  an  opinion 
that  the  presence  of  azotized  matter  is  not  necessary  for  the  generation  of  nitric  add  or' 

Ta  r  w"^  '''  ^"i"'"'  '''  "f  ^^"  ^"^.^^"^^  "^^^'^  atmosphere:  when  condensed  bjcapS. 
laritj,  will  combine  m  such  proportions  as  to  form  nitric  acid,  through  the  agencv  of 
moisture  and  of  neutralizing  bases,  such  as  lime,  magnesia,  potash,  or  soda^    They  conceive 
2^lTr""r  ^^^''""^ .^^'^^^  '?  combine  oxygen  and  hydrogen  into  water,  or  the  v^Tor 
of  alcoho  and  oxygen  into  acetic  acid,  and  as  the  peroxydeas  wdl  as  the  h  drate  of  frSn 
and  argillaceous  minerals,  serve  to  generate  ammonia  from  the  oxygen  of  the  air  and  the 
hydrogen  of  water;  in  like  manner,  porous  limestones,  Ihrough^Oie  agency^^^^^^^^^ 
operate  upon  the  constituents  of  the  atmosphere  to  produce  nitric  acid,  without  thrpreS 
ence  of  animal  matter.     This  opinion  may  certainly  be  maintained;  for  in  India,lpafn 
and  several  other  countries  at  a  distance  from  all  habitations,  unmeise  quantUies  of  ^u! 
petre  are  reproduced  in  soils  which  have  been  washed   the  year  before.     BuronTe 
other  hand,  it  is  known  that  the  production  of  this  salt  may  be  greatly  facilitated  an d  in! 
creased  by  the  admixture  ot  animal  oflals  with  calcareous  earths  '^*^"^^^^^^  ^^'^  "»' 

The  spontaneous  generation  of  nitre  in  Spain,  E^ypt,  and  espedallv  in  India  i^  ^nffi 
aent  to  supply  the  wants  of  the  whole  world.  TherVthis  salt ToSved  to  fo'rm  up^' 
the  surface  of  the  ground  in  silky  tufts,  or  even  in  slender  prismatic  crystairpart^n. 
larly  during  the  continuance  of  the  hot  weather  that  succeeds  copious  rains  These  saUne 
efl^orescences,  after  being  collected  by  rude  besoms  of  broomf  are  lixwited  allowed  to 
settle  evaporated,  and  crystallized.  In  France,  Germany,  Sweden,  Hunlrry&cvaS 
quantities  of  nitrous  salts  are  obtained  by  artificial  arrangements  cXtFj/rt^W^^r 
ni  re-beds     Very  little  nitrate  of  potash,  indeed,  is  obtain^  in  the  fim  pkce    bn  'the 

a  rriiauid"4t;'  Tr^'"'  which  bdng  deliquescent,  remain  in  the  niSous  eartis  in 
a  semi-liquid  state.  The  operation  of  converting  these  salts  into  good  nitre  is  often  suf- 
to  ehmfnate"!''  ^""^  ""  consequence  of  the  presence  of  several  muriaL,  wiichre  di^c^t 

^yll*/!/''"^'"^  instructions  ha.e  been  given  by  the  consulting  committee  of  poudres  et 
mlpetres  m  France,  for  the  construction  of  thdr  m7n>r«  artificielle..  The  perCability 
of  the  materials  to  the  atmospherical  air,  being  found  to  be  as  indisDeB«;able  as  i^  1.1 
presence  of  a  base  to  fix  the  nitric  acid  at  \he  in'stant  of  L7omatTon?thr^^^^  lasi'e 


NITRATE  OF  POTASH. 


871 


is  to  select  a  light  friable  earth,  containing  as  much  carbonate  of  lime  or  old  mortar- 
rubbish  as  possible ;  and  to  interstratify  it  with  beds  of  dung,  five  or  six  inches  thick, 
till  a  considerable  heap  be  raised  in  the  shape  of  a  truncated  pyramid,  which  should  be 
placed  under  an  open  shed,  and  kept  moist  by  watering  it  from  time  to  time.     When 
the  whole  appears  to  be  decomposed  into  a  kind  of  mould,  it  is  to  be  spread  under  sheds 
in  layers  of  from  two  to  three  feet  thick;  which  are  to  be  watered  occasionally  with 
Brine  and  the  drainings  of  dunghills,  taking  care  not  to  soak  them  too  much,  lest  they 
should  be  rendered  impermeable  to  the  air,  though  they  should  be  always  damp  enough 
to  favor  the  absorption  and  mutual  action  of  the  atmospherical  gases.     Moist  garden 
mould  afi'ords  an  example  of  the  physical  condition  most  favorable  to  nitre-beds.     The 
compost  should  be  turned  over,  and  well  mixed  with  the  spade  once  at  least  in  every 
fortnight,  and  the  sides  of  the  shed  should  be  partially  closed ;  for  although  air  be  essen- 
tial, wind  is  injurious,  by  carrying  off  the  acid  vapors,  instead  of  allowing  them  to  rest 
incumbent  upon,  and  combine  with,  the  bases.     The  chemical  reaction  is  slow  and 
•uccessive,  and  can  be  made  effective  only  by  keeping  the  agents  and  materials  in  a 
state  of  quiescence.     The  whole  process  lasts  two  years ;  but  since  organic  matters 
would  yield  in  the  lixiviation  several  soluble  substances  detrimental  to  the  extraction  of 
saltpetre,  they  must  not  be  added  during  the  operations  of  the  latter  six  months  •  nor 
must  any  thing  except  clear  water  be  used  for  watering  during  this  period  ;  at  the  end 
of  which  the  whole  organic  ingredients  of  the  beds  will  be  totally  decomposed.    Where 
dung  is  not  sufficiently  abundant  for  the  above  stratifications,  a  nitre-bed  should  be 
formed  in  a  stable  with  friable  earth,  covered  with  a  layer  of  litter ;  after  four  months 
the  litter  is  to  be  lifted  off,  the  earth  is  to  be  turned  over,  then  another  layer  of  fresh 
earth,  8  or  9  inches  thick*,  is  to  be  placed  over  it,  and  a  layer  of  the  old  and  fresh  litter 
over  all.     At  the  end  of  other  four  months,  this  operation  is  to  be  repeated  ;  and  in  the 
course  of  a  year  the  whole  is  ready  to  be  transferred  into  the  regular  nitre-beds  under  a 
shed,  as  above  described.     Such  are  the  laborious  and  disagreeable  processes  practised 
by  the  peasants  of  Sweden,  each  of  whom  is  bound  by  law  to  have  a  nitre-bed,  and  to 
furnish  a  certain  quantity  of  mire  to  the  state  every  year.    His  nitriary  commonly  con- 
sists ol  a  small  hut  built  of  boards,  with  a  bottom  of  rammed  clay,  covered  by  a  wooden 
floor,  upon  which  is  spread  a  mixture  of  ordinarj-  earth  with  calcareous  sand  or  marl, 
and  lixiviated  wood-ashes.     This  mixture  is  watered  with  stable  urine,  and  its  surface 
is  turned  over  once  a  week  in  summer,  and  once  a  fortnight  in  winter.     In  some 
countries,  walls  2  or  3  feet  thick,  and  6  or  7  high,  are  raised  with  the  nitrifying  com- 
post, interspersed  with  weeds  and  branches  of  trees,  in  order  at  once  to  bind   them 
together,  and  to  favor  the  circulation  of  air.     These  walls  are  thatched  with  straw ; 
they  are  placed  with  one  of  their  faces  in  the  direction  of  the  rains ;  and  must  be  moist- 
ened with  water  not  rich  in  animal  matter.     One  side  of  the  walls  is  upright  and  smooth ; 
while  the  other  is  sloped  or  terraced,  to  favor  the  admission  of  humidity  into  their  interior. 
The  nitre  eventually  forms  a  copious  efflorescence  upon  the  smooth  side,  whence  it  may 
be  easily  scraped  off. 

M.  Longcharap,  convinced  that  organic  matters-are  a  useless  expense,  and  not  in  the 
least  essential  to  nitrification,  proposes  to  establish  nitre-beds  where  fuel  and  labor  arc 
cheapest,  as  amidst  forests,  choosing  as  dry  and  low  a  piece  of  ground  as  possible,  laying 
them  out  upon  a  square  space  of  about  1000  feet  in  each  side,  in  the  middle  of  which  the 
graduation-house  may  be  built,  and  alongside  of  it  sheds  for  the  evaporation  furnaces  and 
K*Tn  r  ^P^'^/^ch  of  the  four  sides  the  nitrifying  sheds  are  to  be  erected,  130  feet  long 
by  JO  feet  wide,  where  the  lixiviation  would  be  carried  on,  and  whence  the  water  wouW 
be  conducted  in  gutters  to  the  graduation-house.  The  sheds  are  to  be  closed  at  the  tides 
by  walls  of  pise,  and  covered  with  thatch.  No  substance  is  so  favorable  to  nitrification 
as  the  natural  stony  concretion  known  under  the  name  of  lime-tuf.  In  Touraine,  where 
It  IS  used  as  a  building  stone,  the  saltpetre  makers  re-establish  the  foundations  of  old 
nouses  at  their  own  expense,  provided  they  are  allowed  to  carry  off  the  old  tuf,  which  owes 
Its  nitritying  properties  not  only  to  its  chemical  nature,  but  to  its  texture,  which  bdns  of  a 
homogeneous  porosity,  permits  elastic  fluids  and  vapors  to  pass  through  it  freely  in  all  di- 
rections. With  the  rough  blocks  of  such  tuf,  walls  about  20  inches  thick,  and  moderately 
high,  are  to  be  raised,  upon  the  principles  above  prescribed  ;  in  the  absence  of  tuf,  porous 

^«h'  Tholf^,'^"*  "^u^  *  ?^V"'«  «^  ^'•^We  soil,  sand,  and  mortar-rubbish,  chalk  or  rich 
marl.    The  walls  ought  to  be  kept  moist. 

thl^'Z'i^^rVJu^^T^VA  ri.**^  ^^^  indigenous  saltpetre  is  obtained  by  lixiviating 
tinWpT"  wh'^h  old  buildings,  especially  of  those  upon  the  ground-floor,  and  in 
sunk  cellars;  which  are  by  law  reserved  for  this  purpose.     The  first  obiec!  of  the 

TZtZlV^Tr^^'y^'^'T^'''.'^^  ""'^'^^^^  «^  ^^'  '"^terials  in  nitrous  salt's,  to  see  if 
they  be  worth  the  trouble  of  working ;  and  this  point  he  commonly  determines  merely 
by  their  saline,  hitter  and  pungent  taste,  though  he  might  readily  have  recourse  to  the 
far  surer  criteria  of  lixiviation  and  evaporation.  He  next  pounds  them  coarsdy,  and 
puis  them  mto  large  casks  open  at  top,  and  covered  with  straw  at  bottom ;  which  are 


i 


I 


272 


NITRATE  OF  SILVER. 


placed  in  three  successive  levels.  Water  is  poured  into  the  casks  till  they  are  full,  and 
after  12  hours'  digestion  it  is  run  off,  loaded  with  the  salts,  by  a  spigot  near  the  bottom. 
A  fresh  quantity  of  water  is  then  added,  and  drawn  off  after  an  interval  of  four  hours  j 
even  a  third  and  fourth  lixiviation  are  had  recourse  to ;  but  these  weak  liquors  arc 
reserved  for  lixiviating  fresh  rubbish.  The  contents  of  the  casks  upon  the  second  and 
third  lower  levels  are  lixiviated  with  the  liquors  of  the  upper  cask,  till  the  leys  indicate 
from  12  to  14  degrees  of  Baume's  hydrometer.  They  are  now  fit  for  evaporating  to  a 
greater  density,  and  of  then  receiving  the  dose  of  wood-ashes  requisite  to  convert  the 
materials  of  lime  and  magnesia  into  nitrate  of  potash,  with  the  precipitation  of  the 
carbonates  of  magnesia  and  lime.  The  solution  of  nitre  is  evaporated  in  a  copper 
pan,  and  as  it  boils,  the  scum  which  rises  to  the  surface  must  be  diligently  skimmed  off 
into  a  cistern  alongside.  Muriate  of  soda  being  hardly  more  soluble  in  boiling  than 
in  cold  water,  separates  during  the  concentration  of  the  nitre,  and  is  progressively 
removed  with  cullender-shaped  ladles.  The  fire  is  withdrawn  whenever  the  liquor  has 
acquired  the  density  of  80°  B. ;  it  is  allowed  to  settle  for  a  little  while,  and  is  then 
drawn  off,  by  a  lead  syphon  adjusted  some  way  above  the  bottom,  into  iron  vessels,  to 
cool  and  crystallize.  The  crystals  thus  obtained  are  set  to  drain,  then  re-dissolved  and 
re-crystallized.  The  further  purification  of  nitre,  is  fully  described  under  the  article 
Gunpowder. 

The  annual  production  of  saltpetre  in  France,  by  the  above-described  processes,  dui  ing 
the  wars  of  the  Revolution,  amounted  to  2000  tons  (2  millions  of  kilogrammes)  of  an  ar- 
ticle fit  for  the  manufacture  of  gunpowder;  of  which  seven  twentieths  were  furnished  by 
the  saltpetre  works  of  Paris  alone.  Considerably  upwards  of  six  times  that  quantity  of 
common  and  cubic  nitre  were  imported  into  the  United  Kingdom,  for  home  consumption, 
iuring  the  year  ending  January  5,  1838. 

Nitrate  of  potash  crystallizes  in  six-sided  prisms,  with  four  narrow  and  two  broad 
faces :  the  last  being  terminated  by  a  dihedral  summit,  or  two-sided  acumination ; 
they  are  striated  lengthwise,  and  have  fissures  in  their  long  axis,  which  are  apt  to  con- 
tain mother  water.  The  spec,  gravity  of  nitre,  varies  from  1'93  to  2*00.  It  possessei 
a  cooling,  bitterish-pungent  taste,  is  void  of  smell,  permanent  in  the  air  when  pure, 
tuses  at  a  heat  of  about  662,  into  an  oily-looking  liquid,  and  concretes  upon  cooling 
into  a  solid  mass,  with  a  coarsely  radiating  fracture.  This  has  got  the  unmeaning 
names  of  sal-prunelle  and  mineral  crystal.  At  a  red  heat,  nitre  gives  out  at  first  a 
great  deal  of  pretty  pure  oxygen  gas ;  but  afterwards  nitrous  acid  fumes,  while  potash 
remains  in  the  retort.  It  is  soluble  in  7  parts  of  water  at  32° ;  in  about  3|  at  60°  F., 
in  less  than  half  a  part  at  194°,  and  in  four  tenths  at  212°.  It  is  very  slightly  soluble 
in  spirit  of  wine,  and  not  at  all  in  absolute  alcohol.  It  causes  a  powerful  deflagration 
when  thrown  upon  burning  coals ;  and  when  a  mixture  of  it  with  sulphur  is  thrown  into 
a  red-hot  crucible,  a  very  vivid  light  is  emitted.  Its  constituents  are,  46-55  potash,  and 
53*45  nitric  acid. 

Nitre  is  applied  to  many  purposes: — 1.  to  the  manufacture  of  gunpowder;  2.  to  that 
of  sulphuric  acid;  3.  to  that  of  nitric  acid,  though  nitrate  of  soda  or  cubic  nitre  has  lately 
superseded  this  use  of  it  to  a  considerable  extent ;  4.  to  that  of  flint-glass ;  5.  it  is  used 
in  medicine ;  6.  for  many  chemical  and  pharmaceutical  preparations ;  7.  for  procuring 
by  deflagration  with  charcoal  or  cream  of  tartar,  pure  carbonate  of  potash,  as  also  black 
and  white  fluxes ;  8.  for  mixing  with  salt  in  curing  butcher  meat ;  9.  in  some  countries 
for  sprinkling  in  solution  upon  grain,  to  preserve  it  from  insects ;  10.  for  making  fire- 
works.   See  FiRE-woRKS. 

Landings,  Deliveries,  and  Stocks  of  Saltpetre. 


Landed. 


Tons. 

In  December     . 

1851 

415 

1850 

607 

In  12  Months    . 

1851 

7,764 

1850 

9,661 

1849 

9,997 

1848 

11,034 

Delivered. 

Stock  1st  January. 

Tons. 

Tons. 

551 

— 

671 

— . 

7,869 

2,321 

10,327 

2,416 

8,774 

8,082 

9,864 

1,794 

Prices. — Bengal,  25«.  to  28«.  6ct  per  cwt. ;  Madras,  24«.  to  25«. 

NITRATE  OF  SILVER  {Nitrate  d'ar^ent,  Fr. ;  Silbersalpeter,  Germ.);  is  pre- 
pared by  saturating  pure  nitric  acid  of  specific  grav.  1*25  with  pure  silver,  evapoi-ating 
the  solution,  and  crystullizing  the  nitrate.     When  the  drained  crystals  are  fused  in  a 

f>latina  capsule,  and  cast  into  slender  cylinders  in  silver  moulds,  they  constitute  the 
unar  caustic  of  the  surgeon.     This  should  be  white,  and  unchangeable  by  light    It  is 
daliquescent  in  moist  air.   The  crystals  are  colorless  transparent  4  and  6  sided  tables ; 


NITRATE  OF  SODA. 


273 


they  possess  a  bitter,  acrid,  and  most  disagreeable  metallic  taste ;  they  dissolve  in  their 
own  weight  of  cold,  and  in  much  less  of  hot  water;  are  soluble  in  four  parts  of  boiling 
Ulcohol,  but  not  in  nitric  acid ;  they  deflagrate  on  redhot  coals,  like  all  the  nitrates ; 
and  detonate  with  phosphorus  when  the  two  are  struck  together  upon  an  anvil.    They 
consist  of  68-2  of  oxyde,  and  3 1-8  of  acid.     Nitrate  of  silver,  when  swallowed,  is  a  very 
energetic  poison ;  but  it  may  be  readily  counteracted,  by  the  administration  of  a  dose 
of  sea^salt,  which  converts  the  corrosive  nitrate  into  the  inert  chloride  of  silver. 
Animal  matter,  immersed  in  a  weak  solution  of  neutral  nitrate  of  silver,  will  keep 
unchanged  for  any  length  of  time ;  and  so  will  polished  iron  or  steel.     Nitrate  of 
silver  is  such  a  delicate  reagent  of  hydrochloric  or  muriatic  acid,  as  to  show  by  a 
sensible  cloud,  the  presence  of  one  113  millionth  part  of  it,  or  one  7  millionth  part  of 
sea-salt  m  distilled  water.    It  is  much  used  under  the  name  of  indelible  ink    for 
writing  upon  linen  with  a  pen  ;  for  which  purpose  one  drachm  of  the  fused  salt  should  be 
dissolved  m  three  quarters  of  an  ounce  of  water,  adding  to  the  solution  as  much  water 
ot  ammonia  as  will  re-dissolve  the  precipitated  oxyde,  with  sap-sreen  to  color  it  and 
gum-water  to  make  the  volume  amount  to  one  ounce.    Traces  written  with  this  liquid 
should  be  first  heated  before  a  fire  to  expel  the  excess  of  ammonia,  and  then  exposed  to 
the  sun-beam  to  blacken.    Another  mode  of  using  nitrate  of  silver  as  an  indelible  ink 
18  to  imbue  the  linen  first  with  solution  of  carbonate  of  soda,  to  diy  the  spot  and  write 
upon  it  with  a  solution  of  nitrate  of  silver,  thickened  with  gum,  and  tinted'  with  sai>- 
green.  *^ 

^NITRATE  OF  SODA,  Cubical  Nitre  (Nitrate  de  sonde,  Fr. ;  Wurfehalpettr, 
Germ.),  occurs  under  the  nitre  upon  the  lands  in  Spain,  India,  Chile,  and  remarkably 
m  Peru,  in  the  districts  of  Atacama  and  Taracapa,  where  it  forms  a  bed  several  feet 
thick.  It  appears  m  several  places  upon  the  surface,  and  extends  over  a  space  of  more 
than  40  leagues,  approaching  near  to  the  frontiers  of  Chile.  It  is  sometimes  efflo- 
rescent,  sometimes  crystallized,  but  oftener  confusedly  mixed  with  clay  and  sand. 
This  immensely  valuable  deposite  is  only  three  days'  journey  from  the  port  of  Con- 
ception in  Chile,  and  from  Iquiqui,  another  harbor  situated  in  the  southern  part  of 

.^^\^-  ""^  ^l^""  T^-  ^^  artificially  prepared  by  neutralizing  nitric  acid  with  soda,  and 
crystallizing  the  solution.     It  crystallizes  in  rhomboids,  has  a  cooling,  pungent,  bitterish 

iJLl";  ?«rjJ'p^'''f^'!^"  f'*'^'  »i,^e<^o°^es  moist  in  the  air;  dissolves  in  3  parts  of 
water  at  60°  F.,  m  less  than  1  part  of  boiling  water;  deflagrates  more  slowly  than  nitre, 
and  with  an  orange  yellow  flame.  It  consists,  in  its  dry  state  of  36  6  soda  and  63-4 
nitric  acid;  but  its  crystals  contain  one  prime  equivalent  of  water;  hence  they  are 
composed  o^  acid  66-84,  base  33-68,  water  9-47. 

It  is  susceptible  of  the  same  applications  as  nitre,  with  the  exception  of  making  gun- 
^w         ^^^  ^^^*^^  i*  ^8  not  adapted,  on  account  of  its  deliquescent  property. 

We  extract  the  following  from  a  paper  read  before  the  Royal  Geoi^raphical  Society 
of  London,  on  the  28th  of  April,  1851,  entitled  Observations  on  the  Geography  of 
Southern  Peru,  <fec.  Ac.  by  W.  Bollaert,  Esq.  F.  R.  G.  S.  o    ir  j 

"The  existence  of  this  valuable  substance  m  the  province  of  Tarapaca  has  been  known 
m  Europe  about  a  century.  In  1820,  some  of  it  was  sent  to  England,  but  the  duty 
then  being  so  high,  it  was  thrown  overboard.  In  1827,  efforts  were  unsuccessfully 
made  by  an  English  house  to  export  it.  In  1830,  a  cargo  was  sent  to  the  United 
btates ;  it  was  found  unsalable  there,  and  a  part  of  it  taken  to  Liverpool,  but  was 
returned  as  unsalable  in  England.  A  cargo  was  then  sent  to  France,  and  in  1831 
another  to  England,  when  it  became  better  known,  and  sold  as  high  as  30&  to  40«.  the 
f  1  cKo^vF"^^  varied  very  much ;  present  quotations  (1851)  about  16».  Since  1831 
V.  ?«on  o/'^P°^^^  ^^  nitrate  from  Iquique  have  been  5,293,478  quintals,  equal  to 
aoout  239  860  tons,  some  of  it  being  used  as  a  fertilizer  of  land,  some  in  the  manufac- 
ture of  nitric  acid.  The  principal  deposits  of  nitrate  of  soda,  yet  known,  are  found  on 
tne  western  side  of  the  Pampa  de  Tamarugal,  commencing  immediately  where  the  level 
plain  ceases,  and  on  the  sides  of  some  of  the  ravines  running  from  the  pampa  towards 
the  coast  and  in  some  of  the  hollows  of  the  mountains.  The  nitrate  has  not  been  found 
nearer  to  the  coast  than  18  miles,  and  looks  as  if  it  gradually  transferred  itself  into  salt 
as  it  approached  the  coast.  The  officinos  or  refining  works  are  divided  into  northern  and 
southern  Saletres ;  the  old  Saletres  being  about  the  centre  of  the  former,  and  La  Nueva 
>oria  that  of  the  latter ;  there  are  in  all  about  100  officinos.  The  nitrate  deposits  com- 
mence aboutTilineche,  and  extend  south  neartoQuiUiagua  with  interruptions  of  deposit* 
of  common  salt.  The  nitrate  caleche  grounds  vary  in  breadth ;  the  average  mky  be 
500  yards,  and  in  places  7  to  8  feet  thick,  and  sometimes  quite  pure.  In  the  ravines 
and  hollows  before  mentioned,  the  nitrate  is  found  on  their  shelving  sides;  the  hol- 
lows look  like  dried-up  cakes,  and  are  covered  with  salt  2  to  3  feet  thick,  and  on  the 
margins  there  is  nitrate  of  soda,  ofttimes  going  down  to  some  depth ;  in  others  there  is 
a  hard  dry  crust  upon  it,  occasionally  4  feet  thick.    The  nitrate  caleche  formed  under  this 

lo 


274 


NITRATE  OF  STRONTIA. 


NITRIC  ACID. 


276 


n 


I  i 


i  t 


erust  18  in  thin  layers,  and  so  solid  and  pure  as  to  be  songht  for,  alUiough  the  eipenao 

"'"m^e^ire'iTefrvarieties  of  the  nitrate  of  soda  caleche,  the  following  being  th. 

principal.  .  .        .  * 

"1.  White,  compact,  containing  64  per  cent. 

"  2.  Yellow,  occasioned  by  salts  of  iodine,  70  per  cent 

"  3    Gray  compact,  containing  a  little  iron  and  a  trace  of  iodine,  46  per  cent.   . 

«4  Giay  crystall^e,  the  molt  abundant  variety,  contains  from  20  to  85  per  cent, 
affording  traces  of  iodine,  with  1  to  8  per  cent  of  earthy  matter. 

"6.  White  crystalline:  this  resembles  the  refined  nitrate.  rr^^  o«^ 

"  All  these  contain  common  salt,  sulphate  and  carbonate  of  soda,  munate  oflime  and 
occafionallv  some  borate  oflime,  as  found  under  the  nitrate  beds:  one  variety  of  the 
UtCcompoBed  of  boracic  acid 49-6,  soda  8;8,  water  26-0,  lime  15-7=100,  may  probably 
become  of  use  in  this  country  in  glass-making,  (fee.  ..     ^   i.   ^    .i  •        „  „«. 

"Fragment  of  shells  have  been  noticed  with  and  under  the  nitrate  bed :  this  may  ac- 
count  income  measure  for  the  lime  in  the  borate  and  munate.  Mr  ^  ^^ke  -n  -^^^^^^^^ 
200  feet  above  the  Pampa  (which  is  3500  above  the  level  of  the  sea),  near  to  Los  »aietre» 
del  fortr'  limestone  containing  shells  rises  from  a  bed  consisting  of  pebbles  and  she  b 
cemenled  togXr  by  salt  and  nitrate  of  soda ;  part  of  the  shells  are  decomposed,  whibt 
Xrfare  pS  in^form,  and  like  those  now  still  found  lying  on  the  rocks  m  the  in 

^'''xLfr'ough  nitrate  of  soda  is  broken  int.>  «°^f .  Pi««f  ^P^t  ^^JJ^/l^^^' Tb!  mlu^ 
duced  and  the  whole  boiled;  the  nitrate  is  held  in  solution,  while  the  earthy  matter; 
ill  pCphat:^  separated  and  fall  to  the  bottom  of  the  v«^!«  '  ^^^ -^"-^;^^ 

solution  of  nitrate  is  let  into  a  reservoir,  where  it  deposits  any  /:«°^*^^^"g  ^^^^^^Xn 
ter;  the  clear  liquor  is  run  into  shallow  troughs.  «?^P^««d  t,<>.t^«  «^°' ^  *in^^^^^^^ 
tak^s  place,  containing  only  2  to  3  per  cent  of  impurities  ^^^'J^'^^yJ^'-Z^^'^^l^^^ 
S  the^coasi  for  exportation.     The  Pampa  de Tamaruagal  contains  ^^^^^.^^^^.^.^M^^^ 
Boda  for  the  consumption  of  Europe  for  ages;  the  desert  of  Atacamo  yields  it,  rt  na» 
also  been  met  with  on  the  Andes  and  in  the  Eastern  plains. 

"Imports  into  the  United  Kingdom  from  Chili  and  Peru  of  Cubic  Nitre.  compUed 

from  Official  Sources. 


Tears. 

ChUL 

Peru. 

Tons. 

Tons. 

1832 

296 

498 

1833 

440 

583 

1834 

2,521 

1,303 

1835 

1,826 

2,068 

1836 

2,183 

1,625 

1837 

1,356 

4,845 

1838 

1,091 

2,099 

1839 

1,488 

2,132 

1840 

2,651 

4,696 

1841 

1,188 

3,546 

1842 

6,048 

4,239 

1843 

6,011 

1,797 

1844 

1,523 

5,531 

1845 

1,487 

6,705 

1846 

2,669 

6,752 

1847 

1,834 

13,506 

1848 

1,676 

8,425 

1849 

4,154 

8,876 

1850 

1,150 

10,740 

NITRATE  OF  STRONTIA.  {Nitrate  de  Strmtiane,  Ft.  ;  Salpetersavrer  stroniim. 
Germ  )  This  salt  is  usually  prepared  from  the  sulphuret  of  strontium,  obtained  by  de- 
composing  sulphate  of  stronlia  with  charcoal,  by  strong  ignition  of  the  mixed  powders  in 
a  wucible.  This  sulphuret  being  treated  with  water,  and  the  solution  being  filtered,  is 
to  be  neutralized  with  nitric  acid,  as  indicated  by  the  lest  of  turmeric  paper ;  care  being 
token  to  avoid  breathing  the  noxious  sulphureted  hydrogen  gas,  which  is  copiously  disen- 
^ed  The  neutral  nitrate  being  properly  evaporated  and  set  aside,  affords  colorless, 
Uansparent,  slender  octahedral  crystals.  It  has  a  cooling,  yet  somewhat  acrid  taste;  is 
«,luble  in  5  parts  of  cold,  and  in  one  half  part  of  boiling  water,  as  also  in  alcohol  i  is 


permanent  m  the  air,  deflagrates  upon  bumin?  coals,  gives  ofl^  oxygen  when  calcined 
and  leaves  caustic  stronlia.  The  sail  consists  of  48-9  stronlia  and  5M  nitric  acid.  That 
salt  is  anhydrous ;  but  there  is  another  variety  of  it,  which  contains  nearly  40  per  cent 
of  water  of  crystallization,  which  occurs  in  large  octahedrons.  This  is  preferred  for  fire- 
works,  because  by  efflorescence  it  is  easily  obtained  in  a  fine  powder,  which  mixes  more 
intimately  with  the  chlorate  of  potash  and  charcoal,  for  the  composition  of  the  brilliant 
red  hres,  now  so  much  admired  in  theatrical  conflagrations. 

NITRIC  ACID,  Aquafortis  (Acide  nitrique,  Fr.  f  Salpetersaiire,  Germ.),  exists,  m  com- 
bination with  the  bases,  potash,  soda,  lime,  magnesia,  in  both  the  mineral  and  vegetable 
kmgdoms.  This  acid  is  never  found  insulated.  It  was  distilled  from  saltpetre  so  lone 
^o  as  the  13th  century,  by  igniting  that  salt,  mixed  with  copperas  or  clay,  in  a  retort 
Witric  acid  is  generated  when  a  mixture  of  oxygen  and  nitrogen  eases,  confined  over 
water  or  an  alkaline  solution,  has  a  series  of  electrical  explosions  passed  through  it  In 
this  way  the  salubrious  atmosphere  may  be  converted  into  corrosive  aquafortis  When 
a  little  hydrogen  is  introduced  into  the  mixed  gases,  standing  over  water  the  chemical 
agency  of  the  electricity  becomes  more  intense,  and  the  acid  is  more  rapidly  fonned  from 
Its  elements,  with  the  production  of  some  nitrate  of  ammonia. 

Nitric  acid  is  usually  made  on  the  small  scale  by  distilling,  with  the  heat  of  a  sand 
bath,  a  mixture  of  3  parts  of  pure  nitre,  and  2  parts  of  strong  sulphuric  acid  in  a  laree 
glass  retort,  connected  by  a  long  glass  tube  with  a  globular  receiver  surrounded  by  cold 
water.     By  a  well-regulated  distillation,  a  pure  acid,  of  specific  gravity  1-500  may  be 
thus  obtained,  amounting  in  weight  to  about  two  thirds  of  the  nitre  employed     To 
obtain  easily  the  whole  nitric  acid,  equal  weights  of  nitre  and  concentrated  sulphuric 
acid  may  be  taken ;  in  which  case  but  a  moderate  heat  need  be  applied  to  the  retort 
The  residuum  will  be  bisulphate  of  potash.     When  only  the  single  equivalent  proporl 
tion  of  sulphuric  acid  is  used,  namely,  48  parts  for  100  of  nitre,  a  much  higher  heat  is 
required  to  complete  the  distillation,  whereby  more  or  less  of  the  nitric  acid  is  decomnosed 
while  a  compact  neutral  sulphate  of  potash  is  left  in  the  retort,  very  difficult  to  remove 
by  solution  in  water,  and  therefore  apt  to  destroy  the  vessel. 

Aquafortis  is  manufactured  upon  the  great  scale  in  iron  pots  or  cylinders  of  the  same 
construction  as  I  have  described  under  muriatic  acid.  The  more  concentrated  the  sul- 
Fn  thT.f      r'     %^^''  corrosively  will  it  act  upon  the  metal ;  and  it  is  commonly  used 

W  I  P'^T  Z*'"  ^^.u''^??  u  ^^  "^.^'^^}  ^"^  *^°  ^^  "^^'■^-  The  salt  being  introduced  into 
the  cool  retort,  and  the  lid  being  luted  tight,  the  acid  is  to  be  slowly  mured  in  through 
the  aperture  /,  Jig.  748  ;  while  the  aperture  g  is  connected  by  a  long  ^lasf  tube  wUh  a 
range  of  balloons  inserted  into  each  other,  and  laid  upon  a  sloping  bed  of  sand.  The 
bottle  t,  with  3  tubulures  partly  filled  with  water,  which  is  required  for  condensing 
muriatic  acid  gas,  must,  for  the  present  purpose,  be  replaced  by  a  series  of  empty  receiv- 
ers,  either  of  glass  or  salt-glazed  stoneware.  The  cylinders  should  be  only  half  fiUed. 
and  be  worked  off  by  a  gradually  raised  heat.  ^ 

.rScTT'*^  •^^^^v^  '^  T^v^  generally  contaminated  with  sulphuric  and  muriatic 
rri^ilv  L.  "".  ""''h  ^i^'^''"^  '^^^?^*^?  ^"^  "^""^^"^-  '^^^  ^"^"t'ty  of  these  salts  may  be 
wh,t^th«r  nf  r  ^'  f7^P«^^^t,ng  m  a  glass  capsule  a  given  weight  of  the  aquafortis  ; 
r.^i  K  •»  /^'^T'"'^^**'  ^""'^  °^^y  ^^  determined  by  nitrate  of  silver;  and  of  sulphurii 
So^'  «Y  T^'^.fl^'y'^'  Aquafortis  may  be  purified  in  a  great  measure,  b?  reSlT 
rMJnJ  ^^"*^^  ^'^^'  ""J""""^  ^^^^''^  ^»^"'^  ^^'^^  comes  over,  as  t  contains  the 
aS,^umrfh"''T^''T^"^  the  middle  portion  as  genuine  nitrii  acid  ;  and  ^v  ng 
a  residuum  m  the  retort,  as  being  contaminated  with  sulphuric  acid. 

lu^TTrr.T'^^A  ^  ^°^*  ^^^  ^^^"  ^'^  abundantly  imported  into  Europe  from  Peru,  it  has 
J^fd  Wn^^*^.^-^  T^y  manufacturers  in  preference  to  nitre  for  the  extraction  of  nitr" 
acid  because  it  is  cheaper,  and  because  the  residuum  of  the  distillation,  be  n  "  sulphate 

Ltl^:'g:,^er;Vr'n\^;^^t^  "^  ^^^^^^^^  ^^^"l,  ^^-^  -*-^^'  ^^^-  -  T^eorZ^ 

TJu2  ^M  ^^  furnace  is  the  apparatus  employed.     Nitric  acid  of  specific  gravity  1^ 

2lXtme"^iirou:tV  ^  portion  of  it  fs  decomposS 

sVen^S^itTxha?p/Jh>    ^^  *'  produced,  which  gives  it  a  straw-yellow  tinge.     At  iWs 
!;l»wn        n        Y^'^^  ""^  "'■^"'^  ^"™«s>  which  have  a  peculiar/ thou-h  not  yery  dL^ 

Se  t  deTs  ;  aTtS>r''"  '^""'t' '''^J,'^  ^^^^^  "'^^-'^^  tastes  extremely  Lu^^^     T?c 
greaiesi  aensiiy  at  which  it  can  be  obtained  is  1-51  or  perhans  1-52  at  fiO"  F    in  whJnh 

.ndra  85  o^i:  r;.' orof'i'v"  ?"™'  '"^^  l"i™--ts  of  26-15  pa™  by  ^eigKa^le. 
men  of  sDecmc  eravitv  >  7f."r?  "^  ""!  '^'''  «*^'  »"■»  ^  volumes  of  the%econd.      ' 

I  j'.M  i  •  '  •  *'  ,  '  """^  of  '"40,  at  246°  F.  If  ia  acid  stron.er  tliaa  l-iUtt 
bed.st.lled  m  a  retort,  It  gradually  becomes  weaker ;  and  H"  weaker  than  r42r4adf 
lUly  becomes  stronger,  .Ul  it  assumes  that  standard  denslly     Add  orspecffic  ^w"; 


276 


NITRIC  ACID. 


NITROGEN,  DEUTOXIDE  OF. 


277 


I  i 


1 


t    i 


( 


i::ii 


i>  lA 


1-485  has  no  more  action  upon  tin  than  water  has,  though  when  either  stronger  or 
weaker  it  oxydizes  it  rapidly,  and  evolves  fumes  of  nitrous  gas  with  explosive  violence. 
In  my  two  papers  upon  nitric  acid  published  in  the  fourth  and  sixth  volumes  of  the 
Journal  of  Science  (1818  and  1819),  I  investigated  the  chemical  relations  of  these  phe- 
nomena.  Acid  of  1-420  consists  of  1  atom  of  dry  acid,  and  4  of  water ;  acid  of  1-48D, 
of  1  atom  of  dry  acid,  and  2  of  water;  the  latter  compound  possesses  a  stable  equi- 
librium as  to  chemical  agency ;  the  former  as  to  calorific.  Acid  of  specific  gravity  1-334, 
consisting  of  7  atoms  of  water,  and  1  of  dry  acid,  resists  the  decomposing  agency  of 
light.  Nitric  acid  acts  with  great  energy  upon  most  combustible  substances,  simple  or 
compound,  giving  up  oxygen  to  them,  and  resolving  itself  into  nitrous  gas,  or  even  azote. 
Such  is  the  result  of  its  action  upon  hydrogen,  phosphorus,  sulphur,  charcoal,  sugar, 
gum,  starch,  sQver,  mercury,  copper,  iron,  tin,  and  most  other  metals. 

From  muriatic  to  nitric  acid  the  transmission  is  easy,  though  nitnc  acid  is  never 
obtained  as  the  waste  product  of  any  chemical  operation.  Its  manufacture  is  invariably 
the  primary  object  of  the  process  by  which  it  is  procured.  The  ordinary  method 
consists  in  heating  together,  in  a  distillatory  apparatus,  a  mi^rture  of  nitrate  of  soda 
or  potash  with  sulphuric  acid.  In  this  way.  the  sulphuric  acid  unites  with  the  soda 
or  potash,  as  the  case  may  be,  forming  commercial  products,  also  salt  cake  and  sal- 
enixen  :  whilst  the  nitric  acid  combines  with  the  water  of  the  suli)huric  acid,  and,  pass- 
ing away  under  the  influence  of  the  heat,  is  condensed  in  the  receiver  of  the  apparatus. 
A  decomposition  of  this  kind  is  sometimes  denominated  a  simple  decomposition ;  but  m 
reality  it  is  not  so,  as  the  transfer  of  the  water  completes  the  cycle  of  elective  afiimty. 

A  Table  of  Nitric  Acid,  by  Dr.  Ure. 


Specific 
I  gfravity. 


Liq. 

Acid 

in  100 


1-5000 

1-4980 

1-4960 

1-4940 

1-4910 

1-4880 

1-4850 

1-4820 

1-4790 

1-4760 

1-4730 

1-4700 

1-4670 

1-4640 

1-4600 

1-4570 

1-4530 

1-4500 

1-4460 

1-4424 

1-4385 

1-4346 

1-4306 

1-4269 

1-4228 


100 
99 
98 
97 
96 
95 
94 
93 
92 
91 
90 
89 
88 
87 
86 
85 
84 
83 
82 
81 
80 
79 
78 
77 
76 


Dry  acid 
in  100 


79-700 
78-903 
78-106 
77-309 
76-512 
75-715 
74-918 
74-121 
73-324 
72-527 
71-730 
70-933 
70-136 
69-339 
68-542 
67-745 
66-948 
66-155 
65-354 
64-557 
63-760 
62-963 
62-166 
61-369 
60-572 


Specific 

gravity. 


1-4189 

1-4147 

1-4107 

1-4065 

1-4023 

1-3978 

1-3945 

1-3882 

1-3833 

1-3783 

1-3732 

1-3681 

1-3630 

1-3579 

1-3529 

1-3477 

1-3427 

1-3376 

1-3323 

1-3270 

1-3216 

1-3163 

1-3110 

1-3056 

1-3001 


Liq 

Acid 
ialOO 


75 

74 

73 

72 

71 

70 

69 

68 

67 

66 

65 

64 

63 

62 

61 

60 

59 

58 

57 

56 

55 

54 

53 

52 

51 


Dry  acid 
in  100 


59-775 

58-978 

58-181 

57-384 

56-587 

55-790 

54-993 

54-196 

53-399 

52-602 

51-805 

51-068 

50-211 

49-414 

48-617 

47-820 

47-023 

46-226 

45-429 

44-632 

43-835 

43-038 

42-241 

41-444 

40-647 


Specific 
gravity. 


1-2947 
1-2887 
1-2826 
1-2765 
1-2705 
1-2644 
1-2583 
1-2523 
1-2462 
1-2402 
1-2341 
1-2277 
1-2212 
1-2148 
1-2084 
1-2019 
1-1958 
1-1895 
1-1833 
1-1770 
1-1709 
1-1648 
1-1587 
1-1526 
1-1465 


Liq. 
Acid 
in  100 


50 
49 

48 

47 

46 

45 

44 

43 

42 

41 

40 

39 

38 

37 

36 

35 

34 

33 

32 

31 

30 

29 

28 

27 

26 


Dry  acid 
in  100. 


39-850 
39-053 
38-256 
37-459 
36-662 
35-865 
35-068 
34-271 
33-474 
32-677 
31-880 
31-083 
30-286 
29-489 
28-692 
27-895 
27-098 
26-301 
25-504 
24-707 
23-900 
23-113 
22-316 
21-519 
20-722 


Specific 
gravity. 


1-1403 
1345 
1286 
1227 
1168 
1.1109 
1051 
1-0993 
1-0935 
1-0878 
1-0821 
1-0764 
1-0708 
1-0651 
1-0595 
1-0540 
1-0485 
1-0430 
1-0375 
1-0320 
1-0267 
1-0212 
1-0159 
10106 
1-0053 


Liq. 

Acid 
in  100 


Dry  acid 
in  100. 


25 

24 

23 

22 

21 

20 

19 

18 

17 

16 

15 

14 

13 

12 

11 

10 

9 

8 

7 

6 

5 

4 

3 

2 

1 


19-925 

19-128 

18-331 

17-534 

16-737 

15-940 

15143 

14-346 

13-549 

12-752 

11-955 

1M58 

10-361 

9-564 

8-767 

7-970 

7-173 

6-376 

5-579 

4-782 

3-98t 

3-188 

2-391 

1-594 

0-797 


It  has  been  proposed,  and  even  carried  into  practice,  to  decompose  nitrate  of  soda  by 
the  action  of  boracic  acid,  so  as  to  produce  biborate  of  soda,  or  borax,  and  thus  render 
the  nitric  acid  a  secondary  product  The  success  of  this  process  depends,  however, 
upon  a  circumstance  of  a  somewhat  curious  kind.  Strong  nitric  acid  is  much  more 
volatile  than  weak  acid;  and  hence  it  is  more  easily  expelled  from  its  combination  with 
soda  in  a  concentrated  than  in  a  diluted  form.  Now,  boracic  acid  has  3  atoms  of  water 
in  its  crystallized  condition  ;  therefore,  if  we  take  2  atoms  of  this  acid,  we  have  6  atoms 
of  water  to  unite  with  the  1  atom  of  nitric  acid  capable  of  being  disengaged  from  nitrate 
of  soda;  whereas  this  quantity  of  nitric  acid  neeeds  at  most  but  2  atoms.  The  secret, 
therefore,  is  to  dry  the  boracic  acid  in  the  first  instance,  so  as  to  get  rid  of  the  surplus 
water;  and  this  is  easily  done  at  a  temperature  of  212°  Fahr.,  at  which  two-thirds  of 

a 


the  water  readily  leave  the  boracic  acid,  and  thus  aflFord  a  mono-hydrated  compound,  2 
atoms  of  which  contain  precisely  the  amount  of  water  needed  for  one  atom  of  nitric 
acid,  and  also  of  the  boracic  acid  requisite  for  the  production  of  the  biborate  of  soda. 
There  are  some  peculiarities  connected  with  the  application  of  the  necessary  tempe- 
rature; but  they  are  of  less  importance.  The  biborate  of  soda  is  afterwards  dissolved 
in  hot  water,  and  crystallized.  This  process  has  been  patented  in  France  within  the 
last  few  years,  by  a  M.  Mallet,  of  Paris.  One  of  the  most  extensive  uses  of  nitric  acid, 
and  for  which,  indeed,  it  is  chiefly  fabricated,  is  the  manufacture  of  oxalic  acid. 

Nitric  Acid,  anhydrotis. — By  treating  nitrate  of  silver  with  perfectly  dry  chlorine^ 
M.  Deville  has  succeeded  in  isolating  anhydrous  nitric  acid,  the  existence  of  which  was 
demonstrated  by  numerous  analyses.  This  beautiful  substance  is  obtained  in  colorless 
crystals,  which  are  perfectly  brilliant  and  limpid,  and  may  be  procured  of  considerable 
size ;  when  they  are  slowly  deposited  in  a  current  of  ^as  rendered  very  cold,  their 
edges  are  a  centimetre  in  length.  These  crystals  are  prisms  of  6  faces,  wnich  appear 
to  be  derived  from  a  right  prism  with  a  rhombic  base.  They  melt  at  a  temperature 
not  much  exceeding  85-5  Fahr, ;  their  boiling  point  is  about  113°;  and  at  60°  the  ten- 
sion of  this  substance  is  very  considerable.  In  contact  with  water  it  becomes  very  hot, 
and  dissolves  in  it  without  imparting  color,  and  without  disenga^ng  any  gas ;  it  then 
produces  with  barytes  the  nitrate  of  that  base.  When  heated,  its  decomposition  ap- 
pears to  commence  nearly  at  its  boiling  point  This  circumstance  is  an  obstacle  to  the 
determination  of  the  density  of  its  vapor  by  the  process  of  M.  Dumas. 

The  process  by  which  M.  Deville  obtained  anhydrous  nitric  acid  is  very  simple  ;  but 
the  readiness  with  which  it  penetrates  tubes  of  caoutchouc  renders  it  necessary  to 
unite  all  the  pieces  of  the  apparatus  by  melting  them.  The  following  is  the  process  : — 
The  author  employs  a  U-shaped  tube  capable  of  containing  500  gr.  of  nitrate  of  silver 
dried  in  the  apparatus  at  356°  Fahr.  in  a  current  of  dry  carbonic  acid  gas.  Another 
very  large  U  tube  is  connected  with  this,  and  to  its  lower  part  is  attached  a  small 
spherical  reservoir ;  it  is  in  this  resorvoir  that  a  liquid  is  deposited  which  always  forms 
during  the  operation,  and  which  is  exclusively  volatile  (nitrous  acid?)  The  tube  con- 
taining the  nitrate  of  silver  is  immersed  in  water  covered  with  a  thin  stratum  of  oil, 
and  heated  by  means  of  a  spirit  lamp  communicating  with  a  reservoir  at  a  constant 
level.  The  chlorine  issues  from  a  glass  gasometer,  and  its  displacement  is  effected  by  a 
slow  and  constant  flow  of  concentrated  sulphuric  acid.  The  chlorine  must  afterwards 
pass  over  chloride  of  lime,  and  then  over  pumice-stone  moistened  with  sulphuric  acid- 
At  common  temperatures  no  effect  appears  to  be  produced.  The  nitrate  of  silver  must 
be  heated  to  203°  Fahr.,  the  temperature  being  then  quickly  reduced  to  136°  or  154°, 
but  not  lower.  At  the  commencement,  hyponitrous  acid,  distinguishable  by  its  color 
and  ready  condensation,  is  produced;  and  when  the  temperature  has  reached  its  lowest 
point,  the  production  of  crystals  begins,  and  they  soon  choke  the  receiver,  cooled  to  6° 
below  zero;  they  are  always  deposited  upon  that  part  of  the  receiver  which  is  not  im- 
raei-sed  in  the  freezing  mixture,  and  M.  Deville  states  that  ice  alone  is  sufficient  to  oc- 
casion their  formation. 

The  gases  are  colored,  and  the  small  sphere  of  the  cooled  tube  contains  a  small 
quantity  of  liquid,  which  must  be  taken  from  the  apparatus  before  the  nitric  acid  is 
removed  to  another  vessel ;  this  latter  operation  is  readily  effected  by  replacing  the 
current  of  chlorine  by  one  of  carbonic  acid.  The  condenser  is  then  to  be  no  longer 
cooled,  and  the  vessel  for  receiving  the  crystals  is  to  be  immersed  in  a  freezing  mixture; 
this  is  fastened  to  the  producing  apparatus  by  means  of  a  caoutchouc  tube  furnished 
with  amianthus.  The  chlorine  should  pass  very  slowly  at  the  rate  of  about  3  or  4  li- 
tres in  24  hours.  All  the  gas,  however,  is  not  absorbed  by  the  nitrate  of  silver.  Oxy- 
gen is  evolved,  the  volume  of  which  appears  to  be  equal  to  that  of  the  chlorine  em- 
ployed. An  apparatus  thus  constructed  operates  day  and  night  without  watching, 
care  being  however  taken  to  renew  the  sulphuric  acid  which  displaces  the  chlorine,  the 
spirit  of  the  lamp,  and  the  ingredients  of  the  freezing  mixture. 

The  author  states  that  he  shall  forward  hereafter  a  more  complete  memoir,  in  which 
he  will  describe  the  chemical  properties  of  the  anhydrous  nitnc  acid,  and  detail  the 
results  of  his  researches  on  the  action  of  ehlorine  and  hypochlorous  acid  on  the  salts 
of  silver. 

NITROGEN,  DEUTOXYDE  OF ;  NUrous  gas,  Nitnc  oxyde  (Deutoxyde  d'azote,  Fr.  t 
Stichstoffoxydy  Germ.)  is  a  gaseous  body  which  may  be  obtained  by  pouring  upon  copper 
or  mercury,  in  a  retort,  nitric  acid  of  moderate  strength.  The  nitrous  gas  comes  over  in 
abundance  without  the  aid  of  heat,  and  may  be  received  over  water  freed  from  air,  or 
over  mercury,  in  the  pneumatic  trough.  It  i^  elastic  and  colorless ;  what  taste  and  smell 
It  possesses  are  unknown,  because  the  moment  it  is  exposed  to  the  mouth  or  nostrils,  it 
absorbs  atmospherical  oxygen,  and  becomes  nitrous  or  nitric  acid.  Its  specific  gravity  is 
1-0393,  or  1-04 ;  whence  100  cubic  inches  weigh  36-66  gr.  Water  condenses  not  more 
than  TjL  of  its  volume  of  this  gas.     It  extinguishes  animal  life,  and  the  flame  of  many 


278 


NITROGEN  GAS. 


NUTMEG 


fit 


1 1 


I 

I 

''■MM' 


[V: 


hi 


combustibles ;  but  of  pbosphorns  well  kindled,  it  brightens  the  flame  in  a  most  re- 
markable degree.  It  consists  of  47  parts  of  nitrogen  gas,  and  63  of  oxygen  gas,  by 
weight;  and  of  equal  parts  in  bulk,  without  any  condensation;  so  that  the  specific 
gravity  of  the  deutoxide  of  nitrogen  is  the  arithmetical  mean  of  the  two  constituents. 
The  constitution  of  this  gas,  and  the  play  of  affinities  which  it  exercises  in  the  formation 
of  sulphuric  acid,  are  deeply  interesting  to  the  chemical  manufacturer. 

The  Hyponitrous  acid^Satpetrigesaure,  Germ.),  like  the  preceding  compound,  deserve* 
notice  here,  on  account  of  the  part  it  plan's  in  the  conversion  of  sulphur  into  sulphuric 
acid,  by  the  agency  of  nitre.  It  is  formed  by  mingling  four  volumes  of  deutoxide  of 
nitrogen  with  one  volume  of  oxygen ;  and  appears  as  a  dark  orange  vapor,  which  is 
condensable  into  a  liquid  at  a  temperature  of  40°  below  zero,  Fahr.  When  distilled, 
this  liquid  leaves  a  dark  yellow  fluid.  The  pure  hyponitrous  acid  consists  of  37  "12 
nitrogen,  and  62*88  oxygen ;  or  of  two  volumes  of  the  first,  and  three  of  the  second. 
"Water  converts  it  into  nitric  acid  and  deutoxide  of  nitrogen ;  the  latter  of  which  escapes 
with  effervescence.  This  acid  oxidizes  most  combustible  bodies  with  peculiar  energy ; 
and  though  its  vapor  does  not  operate  upon  dry  sulphurous  acid,  yet,  through  the 
agency  of  steam,  it  converts  it  into  sulphuric  acid,  itself  being  simultaneously  trans- 
formed into  deutoxide  of  nitrogen ;  ready  to  become  hyponitrous  acid  again,  and  to 
perform  a  circulating  series  of  important  metamorphoses.     See  Sulphuric  Acid. 

NITROGEN,  PREPARATION  OF.  Tliis  process  is  founded  on  the  decomposition 
of  nitrate  of  ammonia,  which,  as  is  already  known,  is  resolved  into  nitrogen  and  wa- 
ter under  the  influence  of  heat ;  but  as  this  salt  is  difficult  to  prepare,  I  replace  it  by  a 
mixture  of  an  alkaline  nitrate  of  potash  and  sal  ammoniac,  a  mixture  which  contains 
the  elements  of  nitrite  of  ammonia  and  chloride  of  potassium.  The  best  method  of 
obtaining  the  nitrite  of  potash  in  a  convenient  state  is  to  pass  nitrous  acid  gas,  formed 
by  the  action  of  10  parts  of  nitric  acid  on  one  part  of  starch,  through  a  solution  of 
caustic  potash  having  a  sp.  gr.  1'38,  until  the  solution  acquires  an  acid  reaction  ;  and 
then  to  add  a  little  caustic  potash,  so  as  to  render  it  distinctly  alkaline.  As  the  solu- 
tion thus  prepared  does  not  undergo  alteration  from  keeping,  it  may  be  held  in  readi- 
ness ;  and  when  the  nitrogen  is  required,  it  is  only  necessary  to  mix  one  volume  of  the 
above  solution  with  three  volumes  of  a  concentrated  solution  of  sal-ammoniac,  and 
to  heat  the  mixture  in  a  flask.  The  disengagement  of  the  gas  takes  place  almost  im- 
mediately, and  continues  with  great  regularit}'. 

As  it  is  necessary,  in  order  to  make  tiie  gas  pure,  that  the  nitrate  should  be  alkaline; 
there  will  be  a  disengagement  at  the  same  time  of  a  little  ammonia,  but  this  is  of  no 
consequence  ;  if  the  nitrogen  be  required  completely  free  from  ammonia,  it  is  sufficient 
to  pass  the  gas  through  a  vessel  containing  water  acidulated  with  a  little  sulphuric 
acid. 

The  following  are  the  experiments  by  which  I  have  satisfied  myself  of  the  purity 
of  the  nitrogen  thus  obtained  : — 

1.  After  freeing  the  gas  from  ammonia  as  above  described,  it  was  conveyed  into  a 
tube  containing  a  mixture  of  zinc,  sulphuric  acid,  and  water ;  into  the  presence,  there- 
fore, of  nascent  hydrogen.  The  experiment  was  continued  for  some  time,  and  when 
concluded  I  could  not  detect  a  trace  of  ammonia  in  the  solution. 

The  solution  was  also  negative  on  testing  it  with  sulphate  of  iron  and  dilute  sul- 
phuric acid. 

2.  I  placed  in  a  glass  tube,  such  as  is  used  for  organic  analysis,  a  determined  quanti- 
ty of  copper  recently  reduced  by  hydrogen,  and  exposed  this  for  half  an  hour  to  the 
action  of  a  red  heat  and  of  a  current  of  the  nitrogen  washed  and  subsequently  dried 
by  passing  it  through  pumice-stone  wetted  with  oil  of  vitriol ;  taking  at  the  same  time 
the  precaution  not  to  heat  the  tube  until  all  the  atmospheric  air  had  been  displaced  by 
the  nitrogen.  This  experiment  was  repeated  several  times,  without  any  alteration 
being  observed  either  in  the  exterior  appearance  of  the  copper  or  in  \t&  weight 

NITROGEN  GAS,  or  AZOTE  (Eng.  and  Fr.;  Sticksioffgas,  Germ.),  constitutes 
about  79  hundredths  of  the  bulk  of  the  atmospheric  air ;  it  is  copiously  disengaged  from 
several  mineral  springs,  as  from  the  natural  basins  of  hot  water  which  supply  the  baths 
of  Leuk,  near  the  Gemmi  in  Switzerland,  and  from  other  springs,  in  the  Pyrenees,  in 
Ceylon,  South  and  North  America,  &c.  It  exists  also  in  flesh  and  most  animal  sub- 
stances, as  well  as  in  some  vegetable  products,  being  one  of  their  essential  constituents. 
When  phosphorus  is  burnt  within  a  jar  filled  with  air,  standing  over  water  in  the  pneu- 
matic trough,  it  consumes  or  absorbs  the  oxygen,  and  leaves  nitrogen,  which  may  be  ren- 
dered pure  by  agitation  with  water.  By  exposing  nitrite  of  ammonia  to  heat  in  a  retort, 
nitrogen  comes  over  alone  in  great  abundance ;  for  the  hydrogen  of  the  ammonia  is  suf- 
ficient to  saturate  the  oxygen  of  the  acid,  and  to  convert  it  into  water ;  while  the  nitro- 
gen of  both  constituents  is  set  at  liberty.  By  transmitting  chlorine  through  water  of 
ammonia,  or  digesting  lean  flesh  in  warm  nitric  acid,  nitrogen  may  also  be  obtained. 
This  permanently  elastic  gas  is  destitute  of  color,  taste,  and  smell ;  it  has  a  specific  gra- 


279 


vity  of  0-976,  air  being  1-000.    Hence  100  cubic  inches  of  it  weigh  29-7  gr.    It  extin- 

NUKOGEN,  PROTOXYDE  OF,  Nitrous  oxyda  (Proioxyde  d' azote,  Fr.:  SiicksiofT- 
oxydul,  Germ.),  is  a  gas  which  displays  remarkable  powers  when  breathed,  causing  in 
many  persons  unrestramable  feelings  of  exhilaration,  whence  it  has  been  called  the  laSch- 
ing  ormtoxicaling  gas.    It  is  prepared  by  exposing  crystallized  nitrate  of  ammonia  to  a 
heat  of  about  3o0°  Fahr.  m  a  glass  retort.     It  is  much  denser  than  the  air  of  the  atmo- 
sphere,  having  a  spec.  grav.  of  1-527;  whence  100  cubic  inches  weigh  46-6  grains.     It 
consists  of  63-64  parts  of  nitrogen,  and  36-36  of  oxygen,  by  weight ;  or  of  two  volumes  of 
nitrogen  and  one  volume  of  oxygen  condensed  by  reciprocal  attraction  into  two  volumes. 
It  is  colorless,  and  possesses  all  the  mechanical  properties  of  the  atmosphere      Water 
previously  freed  from  air  absorbs  its  own  volume  of  this  gas;  and  thus  affords  a  ready 
criterion  for  estimating  its  freedom  from  incondensable  gases,  as  oxygen,  nitrocen  and 
Its  deutoxyde.     Several  combustibles  bum  in  this  gas  with  an  enlarg^^  blue  fndV^ 
yivid  flame ;  and  it  relumes  a  taper  which  has  been  blown  out,  provided  its  tin  h#.  r«i 
hot.     By  powerful  pressure  it  may  be  liquefied.     See  Gas.  ^ 

NITRO-MURIATIC  ACID,  j9qua  regia  (Jcide  nitro-muriatique,  Fr  •  Salveter  sah 
saure  Konisswasser,  Germ.)  is  the  compound  menstruum  invented  by  the  alchemists  foi 
dissolving  gold.     If  strong  nitric  acid,  orange-colored  by  saturation  with  nitrous  gas 
(deutoxyde  of  azote),  be  mixed  with  the  strongest  liquid  muriatic  acid,  no  other  efi-ect  is 
produced  than  might  be  expected  from  the  action  of  nitrous  acid  of  the  same  streneA 
upon  an  equal  quantity  of  water ;    nor  has  the  mixed  acid  so  formed  any  power  of 
acting  upon  gold  or  platma.     But  if  colorless  aquafortis  and  ordinary  muriatic  acid  be 
mixed  toge  her,  the  mixture  immediately  becomes  yellow,  and  acquires  the  power  of 
dissolving  these  two  noble  metals.    When   gently  heated,   pure   chlorine   g^^.^, 
fiomit,  and  its  color  becomes  deeper;  when  further  heated,  chlorine  still  rises,  but  no^ 
mixed  wiUi  nitrous  acid  gas.     If  the  process  has   been   very  long   contLed,   tm 
the  color  becomes  very  dark,  no  more  chlorine  can  be  procured,  knd  the  liquor  has  los 
the  power  of  dissolving  gold.     It  then  consists  of  nitrous  and  muriatic  acids      It  an^are 
therelore    that    aqua  regia  owes   its    peculiar    properties   to  the  mutual   deco^^! 
ion  of  the  nitric  and  muriatic  acids;  and  that  water,  chlorine,  and  nitrous  acid  cTie 
the  results  of    hat  reaction.    Aqua  regia  does  not,  strictly  spewing,  oxyd'^sm 
and  platinum;  it  causes  merely  their  combination  with  chlorine.    It  mfy  b^  c^r^pf^eJ 
^Lwr7  ^t"'^i  proportions  of  the  two  acids;  the  nitric  being  commonly  of  spS^ 
graMty  1-34;  the  muriatic,  of  specific  eravitv  1-18  or  MQ      ^rn^f.rr.^^  o        '■v*^^^'^^ 
at  others  6  parts  of  the  miriatic  acid  S^mhJllhl  ofLr'^nTZ^-^^'u'  ^""^ 
riate  of  ammonia,  instead  of  muriatic  acid?  i^lM^'io  Ll^'a^d  for^i'Sc^^^^ 
as  for  making  a  solution  of  tin  for  the  dyers.      An  aqua  regia  may  also  be  preS^ 
dissolving  nitre  in  muriatic  acid.  h         »  y         ue  preparea  oy 

NITROUS  ACID  (jidde  nitreux,  Fr. ;  Salpetrige  salpdermure,  Germ.)  may  be  wo- 

cm-^  by  distilling,  in  a  coated  glass  retort,  perfectly  dry'^nitrate  of  lead,  intH^gSs^Jt 

c^ver  surrounded  with  a  freezing  mixture.    The  acid  passes  over  in  vapor,  and  cond?nS 

n?h!^;'/   '  oxygen  gas  escapes  through  the  safety  tube ;  while  oxyde  Jf  lead  remains 

nhric  ac'Jd  Ti  ?f  '^i'  '''"/'•  ^^'""^^  "'^^  "^^y  ^^^^  ^'  «^^^i'^«J  ^y  'Ji^'illi"?  strong  fumTg 
JiJ^  #  I '  IJ''^  ^°7^.''  P"""^'^^^  temperature,  and  rectifying  what  comes  over.  At  4<»-i 
«ro  Fahr.,  this  acid  is  coloriess ;  at  32'  it  is  wax  yellow;  at  Q(P  it  has  an  orange  hue 
It  possesses  a  strong  smell,  has  a  very  pungent,  acrid,  sour  taste,  and  a  specie  |rav"^ 
PV.hr  t;.K*rT''"^  decomposes  organic  bodies,  staining  them  yellow.  It  boil,  at  8i^ 
*atir.  with  the  disengagement  of  red  or  orange  fumes.  Its  constituents  are  41-34  of 
JrmpT7«Qi^'^^  58-66  of  anhydrous  nitric  acid ;  or  ultimately  30  68  nSogen  -  1 

^^rt^J^^  acid,  constitutes  the  orange- 

^^I^^f^^^^.:^^  '^--'^^'^  ^-  -^-^=^  -  water  in  their 

ins^^bte^s.  ^^^  ^^'"*'^"  "^""^  °^  '^^  P^^^'  ^^''"*  ^"'^'  «P<*^  w^i<^»»  t^^  cochineal 
J!}IZ^^^J^T.^'^'  ^'y*  i»ft*,fea<ennuM,  Germ.)  is  the  fruit  of  the  mvrutica 
MoT^ca^la^dr'^AlM^^^^^^^^^  f  ^'^^  '-"-^  ^'  J-->  which  growTlT'Jh: 

of  the  fruit  called  mace  nnd  n  .  ^^''  *'^^  "^  ^""^  "^'"^^^^  ?  ^""^  ««^>'  those  porUons 
cLn:l  Jr  ;  ^'^"^^.'"*ce  and  nutmeg  are  sent  into  the  market.  The  entire  fruit  is  a 
species  of  drupa  of  an  ovoid  form,  of  the  size  of  a  peach,  and  furrow^  bi^ud^Lllr 

Jd  bv  rmac'e  anJ'lhir'  ^'''''^^  T  '''^'  ^«"^^^"^  '^^  ^  '^^^  sM,  wlichts  ^^unjl 
fc^ireTlit^to^^^^^^^^^^  'Vhet^li:;  trriL Js  \t:e'^"'  -''''  ^'T'  ""'  ^^ 
April,  which  is  the  best;  one  in  Aug^Hnd  o're^ri^'eLm^r""'  '^'^""^'^  ""'  '» 


u 


n 

'4 


280 


OILS,  UNCTUOUS. 


Tl 


■1 


■-! 


i    " 


Good  nutmegs  should  be  dense,  and  feel  heavy  in  the  hand.  When  they  have  been 
perforated  by  worms,  they  feel  light,  and  though  the  holes  have  been  fraudulently 
stojpped,  the  unsound  ones  may  be  easily  detected  by  this  criterion 

m*tmeffs  aflFord  two  oily  products.    1.  Butter  of  nutmeg,  vulgarly  called  oil  of  mace 
18  obtamed  m  the  Moluccas,  by  expression,  from  the  fresh  nutmegs,  to  the  amount  of 

•*tT-  ""u?^  ^'i^i'T  ^^'«,*'*-    "  '^  *  reddish  yellow  butter-like  substance,  interspersed 
with  Jight  and  dark  streaks,  and  possesses  the  agreeable  smell  and  taste  of  the  nutraeff 
from  the  presence  of  a  volatile  oil.  It  consists  of  two  fats ;  one  reddish  and  soft,  soluble 
J n  cold  alcohol ;  another  white  and  solid,  soluble  in  hot  alcohol     2.  The  volatile  oil  is 
solid,  or  a  stereoptene,  and  has  been  styled  Myristicine. 

in^?i^'^1n^.a^^^i?L^^^'\^^^^'-'/^P^^'^^^'^2^^^^'   exported,  1860,   151,526  Iba.. 
,«/?oo',v      '  ,  °  ^^  '  retained  for  home  consumption,  1850,  168,403  lbs.,  in  1861 
194,132  lbs.;  duty  received,  1350,  19,042/.,  1851,  21,913/. 

NUT  OIL.     See  Oils,  Unctuous. 

NUX    VOMICA,   a  poisonous  nut,  remarkable  for  containing   the  vegeto-alkali 


OILS,  UNCTUOUS. 


281 


O. 

OAK  BARK     See  Tan. 

iK^f^T^l  ^^,!"^"5  ^''•,i  ^«/«".  C^erm.)  The  composition  of  oata  is  less  known  than 
tnat  of  the  other  Cercaha.  Vogel  found  that  100  parts  of  oats  afforded  66  parts  of  flour 
or  meal,  and  34  parts  of  bran ;  but  this  proportion  would  depend  upon  the  quality  of 
the  grain.  The  flour  contains  2  parts  of  a  greenish-yellow  fat  oil ;  8-26  of  bitterish 
sweet  extractive;  2-5  of  gum  ;  3  30  of  a  gray  substance,  more  like  coagulated  albumen 
than  gluten;  59  of  starch;  24  of  moisture  (inclusive  of  the  loss).  Schrader  found  in 
the  ashes  of  oats,  silica,  carbonate  of  lime,  carbonate  of  magnesia,  alumina,  with  oxide« 
of  manganese  and  iron.  -»       ->  -f 

OBSIDIAN,  is  a  glassy-looking  mineral,  with  a  large  conchoidal  fracture,  and  of  a 

/^r^'/ro  iJ  *""%7^'''^  ??^^^  "^^""^  ^^  *^^  blow-pipe  before  it  melts  into  a  white  enamel. 

OCHRE,  yellow  and  brown  (Ocre,  Fr. ;  Ocker,  Germ.);  is  a  native  earthy  mixture  of 
sihca  and  alumina,  colored  by  oxide  of  iron,  with  occasionally  a  little  calcareous 
matter  and  magnesia.  Ochre  occurs  in  beds  some  feet  thick,  which  lie  generally  above 
the  oolite,  are  covered  by  sandstone  and  quartzose  sands  more  or  less  ferruginous  and 
are  accompanied  by  gray  plastic  clays,  of  a  yellowish  or  reddish  color;  all  of  them 
substances  which  contribute  more  or  less  to  its  formation.  The  ochry  earths  are  pre- 
pared for  use  by  grinding  under  edge  millstones,  and  elutriation.  The  yellow  ochres 
may  be  easily  rendered  red  or  reddish  brown  by  calcination  in  a  reverberatory  oven, 
which  oxidizes  their  iron  to  a  higher  d^ree. 

Native  red  ochre  is  caUed  red  chalk  and  reddle  in  England.  It  is  an  intimate  mixture 
of  clay  and  red  uron  ochre ;  is  massive ;  of  an  earthy  fracture  j  is  brownish-red,  blood- 
red,  stains  and  writes  red.  The  oxyde  of  iron  is  sometimes  so  considerable,  that  the 
ochre  may  be  reckoned  an  ore  of  that  metal. 

The  ochre  beds  of  England  are  in  the  iron  sand,  the  lowest  of  the  formations  which 
intervene  between  the  chalk  and  oolites.  Beds  of  fullers  earth  alternate  with  the  iron 
sand.     The  foUowing  is  a  section  of  the  ochre  pits  at  Shotover  Hill,  near  Oxford  :- 


Beds  of  highly  ferruginous  grit,  forming  the  summit  of  the  hill 

Gray  sand 

Ferruginous  concretions 

Yellow  sand 

Cream  colored  loam 

Ochre . 


6  feet. 

3  do. 

1 

6 

4 

0  6  inches. 


Beneath  this,  there  is  a  second  bed  of  ochre,  separated  by  a  thin  bed  of  clay 
Bole,  or  Armenian  bole;  called  also  Lemnian  earth,  and  terra  si?illata,  because  when 
refined  it  was  stamped  with  a  seal ;  is  massive,  with  a  conchoidal  fracture,  a  feeble  lustre, 
reddish-yellow  or  brown,  a  greasy  feel ;  adheres  to  the  tongue,  spec.  grav.  1-4  to  2-0 
It  occurs  in  the  island  Stalimene  (the  ancient  Lesbos),  and  in  several  other  places, 
especially  at  Sienna  ;  whence  the  brown  pigment  called  terra  di  Siena. 

OILS  (HmUs,  Fr. ;  Oele,  Germ.),  are  divisible  into  two  great  classes :  the  fat  or  fixed 
oUs,  hmles  grasses,  Fr. ;  Fette  oele,  Germ. ;  and  the  essential  or  volatile  oils,  HuUes  vola^ 
ttU$,  Fr.  i  Fluchttge,  aethensche  oele.  Germ.      The  former  are  usually  bland  and  mild  to 


to  the  taste;  the  latter  hot  and  pungent  The  term  distilled,  applied  also  to  thp  la«i 
clas^  IS  not  so  correct^  since  some  of  them  are  obtained  by  expression,  as  the  whoie  of 
the  first  class  may  be,  and  commonly  are. 

All  the  known  fatty  substances  found  in  organic  bodies,  without  reference  to  their 
vegetable  or  animal  origin,  are,  according  to  their  consistence,  arranged  under  the 
chemical  heads  of  oils,  butters,  and  tallows.  They  all  possess  the  same  ultimate  con- 
BUtuents,  carbon,  hydrogen,  and  generally  oxygen,  and  in  nearly  the  same  proportions. 

The  following  is  a  list  of  the  Plants  which  yield  the  ordinary  Unctuous  Oils  of 

commerce : 


1. 
2. 
8. 
4. 
6. 
6. 
7. 
8. 
9. 
10. 
11. 
12. 
13. 
14. 
15. 
16. 
J7. 
18. 
19. 
20. 
21. 
22. 
23. 
24. 
25. 
26. 
27. 
28. 
29. 
30. 
31. 
32. 
33. 
34. 
35. 
36. 
37. 
38. 
39. 
4©. 
41. 


Linum  usitatissimum  et  perenne 

Corvlus  avellana  ) 

Juglans  regia        J            *  " 

Papaver  somniferum 

Cannabis  sativa 

'  Sesamum  orientale        -  -     G, 

Olea  Europea  -           -  -    G. 

Amygdalus  communis   -  -    G. 

Guilandina  mohringa    -  -    G. 
Cucurbita  pepo,  and  melapepo     D. 

Fagus  silvatica              -  -    G. 

Sinapis  nigra  et  arvensis  -    G. 
Helianthus  annuus  et  perennis    D. 

Brassica  napus  et  campestris  -    G. 

Ricinus  communis        -  -    D. 

Nicotiana  tabacum  et  rustica  -    D. 

PrunuR  domestica         -  -    G. 

Vitis  vinifera    -            -  -    D. 

Theobroma  cacao          -  -     G. 

Cocos  nucifera               -  -    G. 
Cocus  buiyracea  vel  avoira  elais    G. 

Laurus  nobilis  -           -  -    G. 

Arachis  hypogeea           -  -     G. 

Vateria  indica  -            -  -    G. 

Hesperis  matronalis      -  -    D. 

MyagTum  sativa            -  -    D. 

Reseda  luteola               -  -    D. 

Lepidium  sativum         -  -    D. 

Atropa  belladonna        -  -    d! 

Gossypium  Barbadense  -    D. 

Brassica  campestris  oleifera  -    G. 

Brassica  praecox            -  -    G. 

Raphanus  sativus  oleifer  -    G.' 

Prunus  cerasus              .  •    G. 

Pyrus  mains      -            .  -    g! 

Euonymus  Europaeus   -  -    g! 

Comus  sanguinea         .  -    g! 

Cyperus  esculenta        -  .    g! 

Hyociamus  niger           -  -    g! 

-^sculus  hippocastanum  -    g! 

Pinus  aties       -            .  -     D.* 


D. 

D. 

D. 
D. 


Linseed  Oil 
Nut  oil       - 

Poppy  oil   ... 

Hemp  oil    - 

Oil  of  sesamum 

Olive  oil    - 

Almond  oil 

Oil  of  behen  or  ben 

Cucumber  oil 

Beech  oil   - 

Oil  of  mustard 

Oil  of  sunflower     - 

Rape-seed  oil 

Castor  oil  - 

Tobacco-seed  oil    - 

Plum-kemel  oil 

Grape-seed  oil 

Butter  of  cacao 

Cocoa-nut  oil 
Palm  oil    - 
Laurel  oil  - 
I  Ground-nut  oil 
Piney  tallow 
Oil  of  Julienne 
Oil  of  camelina 
Oil  of  weld-seed    - 
Oil  of  garden  cresses 
Oil  of  deadly  nightshade 
Cotton-seed  oil 
Colza  oil    - 
Summer  rape-seed  oil 
Oil  of  radish-seed  - 
Cherry-stone  oil    - 
Apple-seed  oil 
Spindle-tree  oil 
Comil-berry  tree  oil 
Oil  of  the  roots  of  cyper  grass 
Henbane-seed  oil   - 
Horse-chestnut  oil  - 
Pinetop  oil 


Specific 

graTity. 

0-9347 

0-9260 

0-9243 

0-9276 

a 

0-9176 

- 

0-9180 

. 

0-9231 

- 

0-9226 

- 

0-9160 

» 

0-9262 

- 

0-9136 

- 

0-9611 

- 

0-9232 

0-9127 

0-9202 

0-892 

4» 

0-968 

m 

0-926 

- 

0-9281 

- 

0-9252 

- 

0-9358 

- 

0-9240 

- 

0-9250 

_ 

0-9136 

- 

0-9J39 

- 

0-9187 

- 

0-9239 

- 

0-9380 

iss 

0-9180 

- 

0-9130 

- 

0-927 

- 

0-285 

TZ'lretLTiTfhy^!^"'^'}'^^  through  the  organs  of  vegetable  and  animal  nature, 
iney  are  lound  in  the  seeds  of  many  plants,  associated  with  mucilaL'e  especially  iu 

^eXl  tt  o^lvt^'tt^^^^^^^  occasionally  in  the  fleshy  pulp  su^riuXg  1" 

rndLallv  in  thP  Vont  I    ^  kernels  of  many  fruits,  as  of  the  nut  and  almond  tree, 

matt^ri/cn^  ^n.W^  ^*^^i?  ^'^^  ""l^^"  ^^^^  ^^  P^*"^'     I"  *»in^«l  bodies,  the  oily 
matter  occurs  enclosed  in  thin  membranous  cells,  between  the  skin  and  the  flesfi 
between  the  muscular  fibres,  within  the  abdominal  cavity  in  the  omentum  uponThe 
uitestme^  and  round  the  kidneys,  and  in  a  bony  receptacle  of  theTull  of  Zspel 
Vol.  IL  2  0 


282 


OILS,  UNCTUOUS. 


OILS,  UNCTUOUS. 


283 


i 


)    :\ 


'.\ 


maceti  whale ;  sometimes  in  special  organs,  as  of  the  beaver ;  in  the  gall  bladder,  <fec 
or  mixed  in  a  liquid  state  with  other  animal  matters,  as  in  the  milk. 

Braconnot,  but  particularly  Raspail,  have  shown  that  animal  fats  consist  of  small 
microscopic,  polygonal,  and  partly  reniform  particles,  associated  by  means  of  their 
containing  sacs.  These  may  be  separated  from  each  other  by  tearing  the  recent  fat 
asunder,  rinsing  it  with  water,  and  passing  it  through  a  sieve.  The  membranes  being 
thus  retained,  the  granular  particles  are  observed  to  float  in  the  water,  and  afterwards 
to  separate,  like  the  globules  of  starch,  in  a  white  pulverulent  semi-crystalline  forti. 
The  particles  consist  of  a  strong  membranous  skin,  enclosing  stearine  and  elaine,  or  solid 
and  liquid  fat,  which  may  be  extracted  by  trituration  and  pressure.  These  are  lighter 
than  water,  but  sink  readily  in  spirit  of  wine.  When  boiled  in  strong  alcohol,  the  oily 
principle  dissolves,  but  the  fatty  membrane  remains.  Tliese  granules  have  different 
sizes  and  shapes  in  diflferent  animals  ;  in  the  cal^  the  ox,  the  sheep,  they  are  polygonal, 
and  from  ,„  to  ^  of  an  inch  in  diameter ;  in  the  hog  they  are  kianey-shaped,  and  from 
TO  to  140  o^  ^"^  ^^^^  i  ^^  man,  they  are  polygonal,  and  from  ^q  to  J^  of  an  inch ;  in  insects 
they  are  usually  spherical,  and  not  more  than  ^  of  an  inch. 

The  fat  oils  ire  contained  in  that  part  of  the  seed  which  gives  birth  to  the  cotyledons  i 
ihey  are  not  found  in  the  plumula  and  radicle.  Of  all  the  families  of  plants,  the  cruci- 
form is  the  richest  in  oleiferous  seeds ;  and  next  to  that  are  the  drupacese,  amentaceae, 
and  solanece.  The  seeds  of  the  graminese  and  leguminosac  contain  rarely  more  than  a 
uace  of  fat  oil.  One  root  alone,  that  of  the  cyperus  esculenta,  contains  a  lat  oil.  The 
quantity  of  oil  furnished  by  seeds  varies  not  only  with  the  species,  but  in  the  same  seed, 
with  culture  and  climate.  Nuts  contain  about  half  their  weight  of  oil ;  the  seeds  of  the 
orassica  olerncea  and  campestris,  one  third ;  the  variety  called  colza  in  France,  two  fifths ; 
nempseed,  one  fourth ;  and  linseed  from  one  fourth  to  one  fifth.  Unverdorben  states  that  a 
last  or  ten  quarters  of  linseed  yields  40  ahms=:120  gallons  English  of  oil;  which  is  about 
1  cwt.  of  oil  per  quarter. 

The  fat  oils,  when  first  expressed  without  much  heat,  taste  merely  unctuous  on  thi* 
tongue,  and  exhale  the  odor  of  their  respective  plants.  They  appear  quite  neutral  by  lit- 
mus paper.  Their  fluidity  is  very  various,  some  being  solid  at  ordinary  temperatures,  and 
others  remaining  fluid  at  the  freezing  point  of  water.  Linseed  oil  indeed  does  not  con- 
geal till  cooled  from  4°  to  18°  below  0°  F.  The  same  kind  of  seed  usually  aflbrds  oils 
of  diflerent  desrees  of  fusibility;  so  that  in  the  progress  of  refrigeration  one  portion  con- 
cretes before  another.  Chevreul,  who  was  the  first  to  observe  this  fact,  considers  all  the 
oils  to  be  composed  of  two  species,  one  of  which  resembles  suet,  and  was  thence  styled  by 
liim  stearine ;  and  another  which  is  liquid  at  ordinary  temperatures,  and  was  called  elaine, 
or  oleine.  By  refrigeration  and  pressure  between  the  folds  of  blotting  paper,  or  in  linen 
bags,  the  fluid  part  is  separated,  and  the  solid  remains.  By  heating  the  paper  in  water, 
the  liquid  oil  may  be  obtained  separate.  When  alcohol  is  boiled  with  the  natural  oil,  the 
greater  part  of  the  stearine  remains  undissolved. 

Oleine  may  also  be  procured  by  digesting  the  oil  with  a  quantity  of  caustic  soda  equal 
to  one  half  of  what  is  requisite  to  saponify  the  whole ;  the  stearine  is  first  transformed 
into  soap,  then  a  portion  of  the  oleine  undergoes  the  same  change,  but  a  great  part  of 
it  remains  in  a  pure  state.  This  process  succeeds  only  with  recently  expressed  or  very 
fresh  oils.  The  properties  of  these  two  principles  of  the  fat  oils  vary  with  the  nature  of 
the  respective  oils,  so  that  the  sole  diflference  does  not  consist,  as  many  suppose,  in  the 
diflferent  proportions  of  these  two  bodies,  but  also  in  peculiarities  of  the  several  stearines 
and  oleines^  which,  as  extracted  from  diflerent  seeds,  solidify  at  very  diflerent  tempera- 
tures. 

In  close  vessels,  oils  may  be  preserved  fresh  for  a  very  long  time,  hut  with  contact  of 
air  they  undergo  progressive  changes.  Certain  oils  thicken  and  eventually  dry  into  a 
transparent,  yellowish,  flexible  substance ;  which  forms  a  skin  upon  the  surface  of  the 
oil,  and  retards  its  further  alteration.  Such  oils  are  said  to  be  drying  or  siccative,  and 
are  used  on  this  account  in  the  preparation  of  varnishes  and  painters'  colors.  Other  oils 
do  not  grow  dry,  though  they  turn  thick,  become  less  combustible,  and  assume  an  ofl'en- 
sive  smell.  They  are  then  called  rancid.  In  this  state,  they  exhibit  an  acid  reaction, 
and  irritate  the  fauces  when  swallowe<l,  in  consequence  of  the  presence  of  a  peculiar 
acid,  which  may  he  removed  in  a  great  measure  by  boiling  the  oil  along  with  water  and 
a  little  common  magnesia  for  a  quarter  of  an  hour,  or  till  it  has  lost  the  property  of  red^ 
dening  litmus.  While  oils  undergo  the  above  changes,  they  absorb  a  quantity  of  oxygen 
equal  to  several  times  their  volume.  Saussure  found  that  a  layer  of  nut  oil,  one  quartei 
of  an  inch  thick,  enclosed  along  with  oxygen  gas  over  the  surface  of  quicksilver  in  lh« 
shade,  absorbed  only  three  times  its  bulk  of  that  gas  in  the  course  of  eight  months ;  but 
when  exposed  to  the  sun  in  August,  it  absorbed  60  volumes  additional  in  the  course  of 
ten  days.  This  absorption  of  oxygen  diminished  progressively,  and  stopped  altogether  at 
the  end  of  three  months,  when  it  had  amounted  to  145  times  the  bulk  of  the  oil.  No 
water  was  generated,  but  21'9  volumes  of  carbonic  acid  were  disengaged,  while  the  oil 


was  transformed  in  an  anomalous  manner  into  a  gelatinous  mass,  which  did  not  stain 
paper.  To  a  like  absorption  we  may  ascribe  the  elevation  of  temperature  which  happens 
when  wool  or  hemp,  besmeared  with  olive  or  rapeseed  oil,  is  left  in  a  heap  ;  circumstances 
under  which  it  has  frequently  taken  fire,  and  caused  the  destruction  of  both  cloth-mills 
and  dock-yards. 

In  illustration  of  these  accidents,  if  paper,  linen,  tow,  wool,  cotton,  mats,  straw,  wood 
shavings,  moss,  or  soot,  be  imbued  slightly  with  linseed  or  hempseed  oil,  and  placed  in 
contact  with  the  sun  and  air,  especially  when  wrapped  or  piled  in  a  heap,  they  verj'  soon 
become  spontaneously  hot,  emit  smoke,  and  finally  burst  into  flames.  If  linseed  oil  and 
ground  manganese  be  triturated  together,  the  soft  lump  so  formed  wiU  speedily  become 
firm,  and  ere  long  take  fire. 

The  fat  oils  are  completely  insoluble  in  water.  When  agitated  with  it,  the  mixture 
becomes  turbid,  but  if  it  be  allowed  to  settle  the  oil  collects  by  itself  upon  the  surface. 
This  method  of  washing  is  often  employed  to  purify  oils.  Oils  are  little  soluble  in 
alcohol,  except  at  high  temperatures.  Castor  oil  is  the  only  one  which  dissolves  in  cold 
alcohol.  Ether,  however,  's  an  excellent  solvent  of  oils,  and  is  therefore  employed  to 
extract  them  from  other  bodies  in  analysis;  after  which  it  is  withdrawn  by  dis- 
tillation. 

Fat  oils  may  be  exposed  to  a  considerably  high  temperature,  without  undergoing 
much  alteration  ;  hut  when  they  are  raised  to  nearly  their  boiling  point,  they  begin  to  be 
decomposed.  The  vapors  that  then  rise  are  not  the  oil  itself,  but  certain  products  gene- 
rated in  it  by  the  heat.  These  changes  begin  somewhere  under  600°  of  Fahr.,  and  re- 
quire for  their  continuance  temperatures  always  increasing.  The  products  consist  at  first 
in  aqueous  vapor,  then  a  very  inflammable  volatile  oil,  which  causes  boiling  oil  to  take 
fire  spontaneously ;  and  next  carbureted  hydrogen  gas,  with  carbonic  acid  gas.  In  a 
lamp,  a  small  portion  of  oil  is  raised  in  the  wick  by  capillarity,  which  being  heated,  boils 
and  burns.    See  Rosin-gas. 

Several  fat  oils,  mixed  with  one  or  two  per  cent,  of  sulphuric  acid,  assume  instantly 
a  dark  green  or  brown  hue,  and,  when  allowed  to  stand  quietly,  deposite  a  coloring 
matter  after  some  time.  It  consists  in  a  chemical  combination  of  the  sulphuric  acid, 
with  a  body  thus  separated  from  the  oil,  which  becomes  in  consequence  more  limpid, 
and  burns  with  a  brighter  flame,  especially  after  it  is  washed  with  steam,  and  clarified  by 
repose  or  filtration.  Any  remaining  moisture  may  be  expelled  by  the  heat  of  a  water 
bath. 

The  oils  combine  with  the  salifiable  bases,  and  give  birth  to  the  substance  called 
glycerine  (the  sweet  principle),  and  to  the  margaric,  oleic,  and  stearic  acids.  The  general 
product  of  their  combination  with  potash  or  soda,  is  Soap,  which  see.  Caustic 
ammonia  changes  the  oils  very  diflicultly  and  slowly  into  a  soap ;  but  it  readily  unites 
vilh  them  into  a  milky  emulsion  called  volatile  liniment,  used  as  a  rubefacient  in 
meuicine.  Upon  mixing  water  with  this  liquor,  the  oil  separates  in  an  unchanged 
state.  By  longer  contact,  ammonia  acts  upon  oils  like  the  other  alkalis.  Sea  salt  dis- 
solves in  small  quantity  in  the  oils,  and  so  does  verdigris.  The  latter  solution  is  green. 
Oils  dissolve  also  several  of  the  vegetable  alkalis,  as  morphia,  cinchonia,  quinia,  slr)chia, 
and  delphia. 

Olive  oil  consiste  of  77-2  carbon,  13-4  hydrogen,  and  9-4  oxygen,  in  100  parts.  Sperm, 
aceti  oil,  by  my  analysis,  of  78-9  carbon,  10-97  hydrogen,  and  iO-J3  oxygen. 


Castor  oil     do. 

Stearine  of  olive  oil 

Oleine  of    do.    - 

Linseed  oil 

Nut  oil 

Oil  of  almonds 


74-0 

82-17 

76-03 

76-01 

79-77 

77-40 


10-3 

11-23 

11-54 

11-35 

10-57 

11-48 


15-7  azote, 

6-30  0-30  Saussure, 

12-07  0-35    do. 
12-64  do. 

9-12  0-54    do. 

10-83  0-29 


De  Saussure  concludes  that  the  less  fusible  fats  contain  more  carbon  and  less  oxygen, 
and  that  oils  are  more  soluble  in  alcohol,  the  more  oxygen  they  contain. 

I  shall  now  take  a  short  view  of  the  peculiarities  of  the  principal  expressed  oils. 

Oil  of  almotids,  according  to  Gusseron,  contains  no  stearine ;  at  least  he  could  obtain 
none  by  coohng  it  and  squeezing  it  successively  till  it  all  congealed.  Braconnot  had,  on 
the  contrary,  said,  that  it  contains  24  per  cent,  of  stearine.  I  believe  that  Gusseron  is 
right,  and  that  Braconnot  had  made  fallacious  experiments  on  an  impure  oil. 

OU  of  colza  IS  obtained  from  the  seetls  of  brassica  campestris,  to  the  amount  of  39  per 
cent,  of  their  weight.     It  forms  an  excellent  lamp  oil,  and  is  much  employed  in  France. 

The  corylus  avellana  furnishes  in  oil  60  per  cent,  of  the  weight  of  the  nuts. 

Hempseed  oi/  resembles  the  preceding,  but  has  a  disagreeable  smell,  and  a  mawkish 
taste.    It  is  used  extensively  for  making  both  soft  soap  and  varnishes. 

Linseed  oil  is  obtained  in  greatest  purity  by  cold  pressure;  but  by  a  steam  heat  of 
about  200°  F.  a  very  good  oil  may  be  procured  in  larger  quantity.     The  proportiop  of 


!•« 


S84 


OILS,  UNCTUOUS. 


W 


m 


\l  li 


n 


'  4 


'I. 

m 


'!u 


III 


oa  usually  stated  by  authors  is  22  per  cent,  of  the  weight  of  the  seed ;  but  Mr.  BIundeH 
informs  me,  that,  by  his  plan  of  hydraulic  pressure,  he  obtains  from  26  to  27.  In  the 
Encyclopaxlia  Metropolitana,  under  OU  Press,  a  quarter  of  seed  (whose  average  weight 
K  400  lbs.)  IS  said  to  yield  20  gallons  of  oil.  Now  as  the  gallon  of  linseed  oil  weighs 
9-3  lbs.,  the  total  product  will  be  186  lbs.,  which  amounts  to  more  than  45  per  cent.— an 
extravagant  statement,  about  double  the  ordinary  product  in  oil  mills.  Even  supposing 
the  gallons  not  to  be  imperial,  but  old  English,  we  should  have  upwards  of  38  per  cent! 
of  oil  by  weight,  which  is  still  an  impossible  quantity.  Such  are  the  errors  introduced 
into  respectable  books,  by  adopting  without  practical  knowledge,  the  puffing  statements 
of  a  patentee.  It  dissolves  in  5  parts  of  boiling  alcohol,  in  40  parts  of  cold  alcohol,  and 
in  1-6  parts  of  ether.  When  kept  long  cool  in  a  cask  partly  open,  it  deposites  masses  of 
white  stearine  along  with  a  brownish  powder.  That  stearine  is  very  difficult  of  saponi- 
fication. *^ 

Mustard-^eed  oil.  The  white  or  yellow  seed  affords  36  per  cent,  of  oil,  and  the  black 
seed  18  per  cent.     The  oil  concretes  when  cooled  a  little  below  32°  F. 

Nut  oil  is  at  first  greenish  colored,  but  becomes  pale  yellow  by  time.  It  coneeals  at  the 
same  low  temperature  as  linseed  oil,  into  a  white  mass,  and  has  a  more  drying  quality 

Oil  of  olives  is  sometimes  of  a  greenish  and  at  others  of  a  pale  yellow  color.  A  few 
degrees  above  32^  F.  it  begins  to  deposite  some  white  granules  of  stearine,  especially  if 
the  oil  have  been  originally  expressed  with  heat.  At  22°  it  deposites  28  per  cent,  of  its 
weight  m  stearine,  which  is  fusible  asain  at  68°,  and  affords  72  per  cent,  of  oleine. 
According  to  Kerwych,  oleine  of  singular  beauty  may  be  obtained  by  mixing  2  parts  of 
olive  oil  with  1  part  of  caustic  soda  ley,  and  macerating  the  mixture  for  24  hours  with 
frequent  agitation.  Weak  alcohol  must  then  be  poured  into  it,  to  dissolve  the  stearine 
soap,  whereby  the  oleine,  which  remains  meanwhile  unsaponified,  is  separated,  and  floats 
on  the  surface  of  the  liquid.  This  being  drawn  off,  a  fresh  quantity  of  spirits  is  to  be 
poured  m,  till  the  separation  of  all  the  oleine  be  completed.  It  has  a  slightly  yellowish 
tint,  which  may  be  removed  by  means  of  a  little  animal  charcoal  mixed  with  it  in  a  warm 
place  for  24  hours.  By  subsequent  filtration,  the  oleine  is  obtained  limpid  and  colorless 
of  such  quality  that  it  does  not  thicken  with  the  greatest  cold,  nor  does  it  affect  either 
iron  or  copper  instruments  immersed  in  it. 

There  are  three  kinds  of  olive  oU  in  the  market.  The  best,  caUed  virgin  salad  oil,  is 
Obtained  by  a  gentle  pressure  in  the  cold ;  the  more  common  sort  is  procured  br 
stronger  pressure,  aided  with  the  heat  of  boiUng  water ;  and  thirdly,  an  inferior  kind, 
by  boiling  the  olive  residuum  or  marc,  with  water,  whereby  a  good  deal  of  mucilaginous 
oil  rises  and  floats  on  the  surface.  The  latter  serves  chiefly  for  making  soaps  A  stUl 
worse  oil  is  got  by  aUowing  the  mass  of  bruised  oUves  to  ferment  before  subjecting  it  to 

Oil  of  olives  is  refined  for  the  watchmakers  by  the  following  simple  process.  Into  a 
bottle  or  phial  containing  it,  a  slip  of  sheet  lead  is  immersed,  and  the  bottle  is  placed 
at  a  window,  where  it  may  receive  the  rays  of  the  sun.  The  oil  by  degrees  gets 
covered  with  a  curdy  mass,  which  after  some  time  settles  to  the  bottom,  while  iteelf 
becomes  limpid  and  colourless.  As  soon  as  the  lead  ceases  to  separate  any  more  of 
that  white  substance,  the  oil  is  decanted  off  into  another  phial  for  use. 

There  are  four  different  kinds  of  olive  oil  known  in  the  districts  where  it  is  pre- 
pared: 1  the  virgin  oil;  2.  the  ordinary  oil  {huile  ordinaire);  3.  oil  of  the  infernal 
regions  (hmle  d'enfer);  4.  oil  prepared  by  fermentation. 

1.  Virgin  oil.  In  the  district  Montpellier,  they  apply  the  term  virgin  oil  to  that 
which  spontaneously  separates  from  the  paste  of  crushed  olives.  This  oil  is  not  met 
with  m  commerce,  being  all  used  by  the  inhabitants  of  the  district,  either  as  an  emollient 
remedy,  or  for  oiling  the  works  of  watches. 

In  the  district  of  Aix,  they  give  the  name  virgin  oil  to  that  which  is  first  obtained 
from  the  olives  ground  to  a  paste  in  a  mill,  and  submitted  to  a  slight  pressure  2  or  3 
days  after  collecting  the  fruit  Thus,  there  is  no  virgin  oil  brought  from  Montpellier. 
but  a  good  deal  of  it  is  brought  from  Aix.  o  6  t         * 

2.  Ordinary  oil.  In  the  district  of  Montpellier,  this  oil  is  prepared  bv  pressing  the 
olives,  previously  crushed  and  mixed  with  boiling  water.  At  Aix  the  ordinary  oil  is 
made  from  the  olives  which  have  been  used  for  obtaining  the  virgin  oil.  The  paste, 
which  has  been  previously  pressed,  is  broken  up,  a  certain  quantity  of  boiling  water 
IS  poured  over  it,  and  it  is  then  again  submitted  to  the  press.  By  this  second  exTTreesion. 
m  which  more  pressure  is  applied  than  in  the  previous  one,  an  oil  is  obtained  some- 
what inferior  in  quality  to  the  virgin  oil.  The  oil  is  separated  from  the  water  in  a 
lew  hours  after  the  operation. 

3.  Oil  of  the  infernal  regions  {huile  d'enfer).  The  water  which  has  been  employed 
m  the  precedmg  operation,  is,  in  some  districts,  conducted  into  large  reservoirs,  called 
the  infernal  regions,  where  it  is  left  for  many  days.     During  this  period,  any  oil  that 


OILS,  UNCTUOUS.  285 

nd^ht  have  remained  mixed  with  the  water  separates,  and  coUeets  on  the  surface 
This  oil  bemg  very  inferior  in  quality,  is  only  ^t  for  burning  in  lamps,  for  Xhli 
answers  very  well     It  is  sometimes  called  lamp  oil  6  y°y  *"f  wmcn  ii 

4  Fermented  oil  {huile  fermentee}  This  is  obt;ined  in  the  two  above-named  dis- 
tncts,  by  leaving  the  fresh  olives  in  heaps  for  some  time,  and  pouring  boiWwa^ 
over  them  before  pressing  the  oil  But  this  method  is  very  seldom  put^n  pfalicl 
for  the  olives  during  this  fermentation  lose  their  peculiar  flavour,  become  inuchheat^ 
and  acquire  a  musty  taste,  which  is  communicated  to  the  oil         "^^^^^^  ™^<^^  Heated, 

The  fruity  flavour  of  the  oil  depends  upon  the  Quality  o*f  the  olives  from  which  it 
has  been  pressed,  and  not  upon  the  method  adopted  in  its  preparatioT 

There  are  met  with  in  commerce  the  virgin  oil  of  Aix.  rarplv  fKo  ^.n  «i.*  •     j  u 
fermentation,  and  never  the  oil  of  the  infemll  regions.  ^         ^  obtained  by 

oIP^^'/'^n'^inT^^'n'K  ^^*^°  ^''  *5l  ''  "^'i  u  '^""'^'^  ^^  ^^  P^'^^  ^^^  ^t^*""^  and  69  of 
Oieine  m  100.  It  becomes  readily  rancid  by  exposure  to  air,  and  is  whitened  at  the 
same  time. 

The  oil  extracted  from  the  plucked  tops  of  the  pinus  alms,  in  the  Black  Forest  in 
Germany,  is  limpid,  of  a  golden  yeUow  color,  and  resembles  in  smell  and  taste  the  oil  of 
turpentine.     It  answers  well  for  the  preparation  of  varnishes, 
for^am^s  ^•^'''*"*^'^^  ^^  ^^^^  ^^^^^^  *^  Wurtemberg,  and  is  found  to  answer  very  weU 

Poppy-seed  oil  has  none  of  the  narcotic  properties  of  the  poppy  juice.  It  is  soluble  in 
ether  m  every  proportion.  oviuujc  in 

Rape-seed  oil  has  a  yellow  color,  and  a  peculiar  smell.  At  25°  F.  it  becomes  a  vellow 
mass,  consisting  of  46  parts  of  stearine,  which  fuses  at  50°,  and  54  of  oleine,  in  which 
the  smell  resides.  '      '♦""-h 

The  oils  of  belladonna  seeds,  and  tobacco  seeds,  are  perfectly  bland.  The  foi-mer  i« 
much^used  for  lamps  in  Swabia  and  Wurtemburg.      The  oilcakes  of  both  are  poU 

_  Oa  of  wim-stwuis  is  extracted  to  the  amount  of  10  or  11  per  cent,  from  the  seeds  of 
Hitifkof  *diet     '  "-'  ^""'  ^"^^  ^'"^'''  **"'  ''  '^"^""'  ^^^  «5^-      I^is  usS  as  ai 

PAT  OIL  MANUFACTURE. 

^onlA'*'^^'**''^'*'^?^^!"*'^*/"  ^^^  proprietors  in  the  neighborhood  of  Aix,  in  Pro- 
vence, to  preserve  the  olives  for  15  days  in  barns  or  ceUars,  till  they  havl  underio,^ 
a  species  of  fermentation,  in  order  to  facilitate  the  extraction  of  hefrdl  If  this  ^^^^^^^^ 
tice  were  really  prejudicial  to  the  product,  as  some  theorists  have  said,  would  not  tie  h?4 
reputation  and  price  of  the  oil  of  Aix  have  long  ago  suffered,  and  have  induct  them  to 
change  their  system  of  working  ?  In  fact,  all  depends  upon^he  degree  of  feSientaTion 
w  tottick^o7«rl"'*  """frf  '^  mould  in  damp  places,  to  lie  in  heaps,  to  softeTsS 
JhPrmnlti  1  "ii^''  ^""^^'^^^^'^^  a  reddish  liquor,  or  to  become  so  hot  as  to  raise  a 
thermometer  plunged  into  the  mass  up  to  96°  F.  In  such  a  case  they  would  afford 
an  acrid  nauseous  oil,  fit  only  for  the  woollen  or  soap  manufactories.  A  sLrfermenta. 
^!S^To^''rJ'''V'  r*^"''  towards  separating  the  oil  from  the  mucilage!  The  oiwt 
are  then  crushed  under  the  stones  of  an  edge-mill,  and  next  put  into  a  screw-press  bein« 

ThtoTl  is"runtf?tn"''.H''"'K^^'^r^V^'^i'  ""'''  T^  «^»^-  ^«  the  nVmf^To'f  dg'h'^en' 
1  he  oil  IS  run  off  from  the  channels  of  the  ground-sill,  into  casks,  or  into  stone  cistern* 

?owt  gradird.''"''  '''''  ^^^'  "^^"-      ^'^  P^^^^"^^  ^PP^^^  '-  ^h«  ca6a,  shoSd^* 

What  comes  over  first,  without  heat,  is  the  virgin  oil  already  mentioned       The  cnhaM 

being  row  removed  from  the  press,  their  contents  are  shovelLrou  ,  m^'ed  w^th  ^me 

^    SI  n^f^'^'A-T-"  P"'  •'"  i^^  ^^^^'  *"^  P^^«««l  anew.      The  hot  wat^r  hel^to  T^^ 
ofi  the  oil,  which  IS  received  in  other  casks  or  pizes.    The  oil  ere  Ion-  accumlates  at  thT 

^t  rancTd  whrn^k^^^^      Th^  If  ?  ^"^  article,  and  quite  fit  for  table  use,  but  is  ap"  to 
H^n^r  fiT  ^''^".,*^^Pt-  ^The  subjacent  water  retains  a  good  deal  of  oil,  bv  the  interven 

faclo^  pulses.  "*^'  "  °^  '"  '""=""  "'""'y'  '"d  <=»»  ^  "sed  only  for 

~^crarUcle!"'"'  """"^  '"  "  """''><"'«'  '"■»  water,  and  expressed,  yields  .  sUll 
decree  Fahf  Tuea^  foTfw/nl'vT"^  in  clean  ,„„„  in  ,„  apartment  heated  to  the  60tl. 
.rl"<^fed"1;-  aVZ':  Ind'rn'Ll,?rn'.„''Sr;  l';fe,"  "  ™"  ""^  '"•"  *'""«  ^''  ^'"''^ 


286 


OILS,  UNCTUOUS. 


OILS,  UNCTUOUS. 


287 


§\  \ 


VI! 


tnem  strongly  between  a  series  of  cast  iron  plates,  in  a  hydraulic  press ;  without  heftt 
at  first,  and  then  between  heated  plates.  The  first  oil  is  the  purest,  and  least  apt  to 
become  rancid.  It  should  be  refined  by  filtering  through  porous  paper.  Next  to  olive 
oil,  this  species  is  the  most  easy  to  saponify.  Bitter  almonds,  being  cheaper  than  the 
sweet,  are  used  in  preference  for  obtaining  this  oil,  and  they  aflbrd  an  article  equally 
bland,  wholesome,  and  inodorous.  But  a  strongly  scented  oil  may  be  procured,  accord- 
ing to  M.  Planche,  by  macerating  the  almonds  in  hot  water,  so  as  to  blanch  thom 
then  drying  them  in  a  stove,  and  afterwards  subjecting  them  to  pressure.  The  voiatil* 
oil  of  almonds  is  obtained  by  distilling  the  marc  or  bitter  almond  cake,  along  with  water. 
See  Press  Hydraulic,  and  Stearine. 

Linseed,  rapeseed,  poppyseed,  and  other  oleiferous  seeds  were  formerly  treated  for 
the  extraction  of  their  oil,  by  pounding  in  hard  wooden  mortars  with  pestles  shod  with 
iron,  set  in  motion  by  cams  driven  by  a  shaft  turned  with  horse  or  water  power,  then 
the  triturated  seed  was  put  into  woollen  bags  which  were  wrapped  up  in  hair-cloths, 
and  squeezed  between  upright  wedges  in  press-boxes  by  the  impulsion  of  vertical  rams 
driven  also  by  a  cam  mechanism.  In  the  best  mills  upon  the  old  construction,  the  cakes 
obtained  by  this  first  wedge  pressure  were  thrown  upon  the  bed  of  an  edge-mill,  ground  anew 
and  subjected  to  a  second  pressure,  aided  by  heat  now,  as  in  the  first  case.  These  mor- 
tars and  press-boxes  constitute  what  are  called  Dutch  mills.  They  are  still  in  very 
general  use  both  in  this  country  and  on  the  Continent ;  and  are  by  many  persons  sup- 
posed to  be  preferable  to  the  hydraulic  presses. 

The  roller-mill,  for  merely  bruising  the  linseed,  &c.,  previous  to  grinding  it  under  edge- 
ftones,  and  to  heating  and  crushing  it  in  a  Dutch  or  a  hydraulic  oil-mill,  is  represented 

in  figs.  101?.  and  1013.  The  iron  shaft 
a,  has  a  winch  at  each  end,  with  a 
heavy  fly-wheel  upon  the  one  of  them, 
when  the  machine  is  to  be  worked  ly 
hand.  Upon  the  opposite  end  is  a  pu  '- 
ley,  with  an  endless  cord  which  passt  s 
round  a  pulley  on  the  end  of  the  fluted 
roller  6,  and  thereby  drives  it.  This  fluted 
roller  6,  lies  across  the  hopper  c,  and  by 
its  agitation  causes  the  seeds  to  descend 
equably  through  the  hopper,  between  the 
crushing  rollers  d,  e.  Upon  the  shaft  a, 
there  is  also  a  pinion  which  works  into 
two  toothed  wheels  on  the  shafts  of  the 
crushing  cylinders  CL  and  e,  thus  commu- 
nicating to  lliese  cylinders  motion  in 
opposite  directions.  /,  g  ar«;  two  scraper- 
blades,  which  by  means  of  the  two 
weights  h,  hy  hanging  upon  levers,  are 
pressed  against  the  surfaces  of  the  cyl- 
inders, and  remove  any  seed-cake  from 
them.  The  bruised  seeds  fall  through  the 
slit  i  of  the  case,  and  are  received  into  a 
chest  which  stands  upon  the  board  k. 

Machines  of  this  kind  are  now  usually 
driven  by  power.  Hydraulic  presses  have 
been  of  late  years  introduced  into  many 
seed-oil  mills  in  this  country ;  but  it  in 
still  a  matter  of  dispute  whether  they,  or 
the  old  Dutch  oil-mill,  with  bags  of  seed 
compressed  between  wedges,  driven  by 
cam-stamps,  be  the  preferable ;  that  is, 
aflTord  the  largest  product  of  oil  with  the 
same  expenditure  of  capital  and  power. 
For  figures  of  hydraulic  presses,  see 
Press,  and  Stearine. 

This  bruising  of  the  seed  is  merely  a 
preparation  for  its  proper  grinding  under 
a  pair  of  heavy  edge  stones,  of  granite,  from  5  to  7  feet  in  diameter;  because  unbruised 
seed  is  apt  to  slide  away  before  the  vertical  rolling  wheel,  and  thus  escape  trituration. 
The  edge-mill,  for  grinding  seeds,  is  quite  analogous  to  the  gunpowder-mill  represented 
in  fig.  740,  page  980.  Some  hoop  the  stones  with  an  iron  rim,  but  others  prefer,  and  I 
think  justly,  the  rough  surface  of  granite,  and  dress  it  from  time  to  time  with  hammers, 
as  it  becomes  irregular.     These  stones  make  from  30  to  36  revolutions  upon  their 


horizontal  bed  of  masonry  or  iron  in  a  minute.  The  centre  of  the  bed,  where  it  is  per- 
forated for  the  passage  of  the  strong  vertical  shaft  which  turns  the  stones,  is  enclosed  by 
a  circular  box  of  cast  iron,  firmly  bolted  to  the  be^-stone,  and  furnished  with  a  cover. 
This  box  serves  to  prevent  any  seeds  or  powder  getting  into  the  step  or  socket,  and 
obstructing  the  movement.  The  circumference  of  the  mill-bed  is  formed  of  an  upright 
rim  of  oak- plank,  bound  with  iron.  There  is  a  rectangular  notch  left  in  the  edge  of  the 
bed,  and  corresponding  part  of  the  rim,  which  is  usually  closed  with  a  slide-plate,  and 
*•  opened  only  at  the  end  of  the  operation,  to  let  the  pasty  seed-cake  be  turned  out  by 
the  oblique  arm  of  the  bottom  scraper.  The  two  parallel  stones,  which  are  set  near  eacn 
other,  and  travel  round  their  circular  path  upon  the  bed,  grind  the  seeds  not  merely  bv 
their  weight,  of  three  tons  each,  but  also  by  a  rubbing  motion,  or  attrition  •  because  their 
periphery  being  not  conical,  but  cylindrical,  by  its  rolling  upon  a  plane  surface,  must  at 
every  instant  turn  round  with  friction  upon  their  resting  points.  Stron«'  cast-iron  boxes 
are  bolted  upon  the  centre  of  the  stones,  which  by  means  of  screw  clamps  seize  firmly  the 
horizontal  iron  shafts  that  traverse  and  drive  them,  by  passing  into  a  slit-groove  the 
vertical  turning  shaft.  This  groove  is  lined  with  strong  plates  of  steel,  which  wear  rap- 
idly by  the  friction,  and  need  to  be  frequently  renewed. 

The  seeds  which  have  been  burst  between  the  rolls,  or  in  the  mortars  of  the  Dutch 
mills,  are  to  be  spread  as  equably  as  possible  by  a  shovel  upon  the  circular  path  of  the 
edge-stones,  and  in  about  half  an  hour  the  charge  will  be  sufficiently  ground  into  a  paste. 
This  should  be  put  directly  into  the  press,  when  fine  cold-drawn  oil  is  wanted.  But  in 
general  the  paste  is  heated  before  being  subjected  to  the  pressure.  The  pressed  cake  if 
again  thrown  under  the  edge-stones,  and,  after  being  ground  the  second  time,  should  be 
exposed  to  a  heat  of  212°  Fahr.,  in  a  proper  pan,  caUed  a  steam-kettle,  before  being 
subjected  to  the  second  and  final  pressure  in  the  woollen  bags  and  hair-cloths. 
Fig.  1014  is  a  vertical  section  of  the  steam-kettle  of  Hallette,  and^g.l015is*a  view  of 

the  seed-stirrer.     a,  is  the  wall  of  ma- 
sonry, upon  which,  and  the  iron  pillars 
b,  the  pan  is  supported.     It  is  enclosed 
in  a  jacket,  for  admitting  steam  into  the 
intermediate  space  d,  rf,  d,  at  its  sides 
and  bottom,      c,  is  the  middle  of  the 
pan  in  which  the  shaft  of  the  stirrer  is 
planted   upright,   resting   by   its  lower 
end  in  the  step  e ;  /,  is  an  opening,  by 
which  the  contents  of  the  pan  may  be 
emptied;    g,  is  an  orifice  into  which 
the  mouth  of  the  hair  or  worsted  bag 
is    inserted,   in   order   to   receive   the 
heated  seed,  when  it  is  turned  out  by 
the  rotation  of  the  stirrer  and  the  with- 
drawal of  the  plug/ from  the  discharge 
aperture;    hy  is   the    steam    induction 
pipe;  and  t,  the  eduction  pipe,  which 
serves  also  to  run  oflf  the  condensed 
water. 

The  hydraulic  oil-press  is  generally 
double;  that  is,  it  has  two  vertical  lams 
placed  parallel  to  each  other,  so  that 

oth*»r  «i\ip  .-c  Ko.«„  AX.        J,      rj.^     ^  ^^^'^  °"^  ^^^^  ^s  ^^^^^  pressure,  the 

other  side  is  being  discharged.     The  bags  of  heated  seed-paste  or  meal  are  put  into 
ca  t-.ron  cases  which  are  piled  over  each  other  to  the  number  of  6  or  8,  upon  the  pi^ 

Ss  of  seeH  flo^r  ^       V^  ^^  P'^'''  '"^  ^  well-going  establishment,  should  work  38 
pounds  of  seed-flour  every  5  minutes.     Such  a  press  will  do  70  quarters  of  Unseed  in 

a:h'l7^ula;^eT?&h"'''  ''''  labor  of  Sne  man  at  20,.\VX"ee 'boyTaf  5 " 
^ge-'stones.  '^  ^''''^'  ^"  ""^'^  '^  ^^"'  ^^"^  ^'^^  ^^^  ^^U^  and  the 

no{ertikefi^L'"L'^rn!l'"''^r?  ^''  ^'  Woo.sey,  for  the  foUowing  most  valuable 
seld-VushlngLg^^^^^^^^^  P^^^^^"^  ^^^'  ^^'  '•^--^^  upon  the  subject  of 

se^'^wUl^^etd  mit  on'^T"'^  "P*^'^  '^^  ^1"^^^  ^^  '^^  «°»Ployed.     Heavy 

^e7^  Z  iZen  ^l'Z\l^f  '^r^  ""^«''  *  *»«^  «""'  a"d  where  the  flax  is  not 
SS  bushel  nrnLlw  ^^'  ^^^  "^^'^^^  «^  ^''''^^  ^^^^^  froM  48  to  52  Ibs.  per 
Sr  ^Infj^Z^^lfV^TJ''''  ^^^''^^^  i«  49  lbs.,  or  392  Ibs.  per  imperial 
quarter.    I  inspected  one  of  the  seed-crusher's  books,  and  the  average  of  15  trials  of  a 


m 

}>'i 


\     ti 


^ 


li 


It 


288 


OILS.  UNCTUOUS. 


quarter  each  of  different  seeds  in  the  season  averaged  14J  galls,  of  7|  lbs.  each;  say, 
109  lbs.  of  oil  per  quarter.  This  crusher,  who  uses  only  the  hydraulic  press,  and  one 
pressing,  informed  me  that — 

Archangel  seed  will  yield  from    -       -       -        -    15  to  16  galls,  (of  7^  lbs.  each) 

Best  Odessa       -        -        -        --        -        -18  and  even  19  galls. 

Good  crushing-seed     ------     16|  do. 

Low  seed,  such  as  weighs  48  lbs.  per  bushel        -    13|  do. 

•*  The  average  of  the  seed  he  has  worked,  which  he  represents  to  be  of  an  inferior 
quality,  for  the  sake  of  its  cheapness,  yields  14 J  galls,  per  quarter.  I  had  some  Ameri- 
can seed  which  weighed  52J  lbs.  per  imperial  bushel,  ground  and  pressed  under  my 
own  observation,  and  it  gave  me  111  lbs.  oil;  that  is  to  say,  418  lbs.  of  seed  gave  111 
lbs.  oiI=26yS^^  per  cent.     A  friend  of  mine,  who  is  a  London  crusher,  told  me  the  oil 

varied  according  to  the  seed  from  14  to  17  galls. ;  and  when  you  consider  the  relative 
value  of  seeds,  and  remember  that  oil  and  cake  from  any  kind  of  seed  is  of  the  same  vahUf 
it  will  be  apparent  that  the  yield  is  very  different ;  for  example, 

oK»i,  T  1     1QQC   (  E.  India  linseed  worth  52*.  per  quarter. 

zoth  July,  iSdb,  ^  Petersburg  Unseed        48    to  52  do. 

prices  of  seed,   ^(j^^g^     °  -        .        52        -        - 

The  difference  of  4s.  must  be  paid  for  in  the  quantity  of  oil,  which  at  38*.  6d.  per  cwt. 
(the  then  price)  requires  about  11^  lbs.  more  oil  expressed  to  pay  for  the  difference  in 
the  market  value  of  the  seed.  Another  London  crusher  informed  me  that  East  India 
linseed  will  produce  17  gallons,  and  he  seemed  to  think  that  that  was  the  extreme  quan- 
tity that  could  be  expressed  from  any  seed.  The  average  of  last  year's  Russian  seed 
would  be  about  14  galls. ;  Sicilian  seed  16  galls. 


Num- 

Place. 

Engine  Power. 

Hydraulic 
Presses. 

Stampers. 

Rollers. 

Edge- 
stones. 

Kettles 

Work  done, — 

reduced  to 

an  hour. 

ber  of 
press- 
ings. 

Prance 

10  horse  power 

1   hydrau- 

5     light 

1  pair 

1  pr.  edge- 

5  table  kettles 

1  English 

2  pres- 

lic, 200 

stamp- 

rolls. 

stones. 

small    size 

quarter   per 

sings. 

tons. 

ers. 

heated    by 
steam. 

working 
hour. 

London 

20  horse  power 

1  hydrau- 

13     light 

1  pair 

2  pr.  edge- 

8  table  kettles 

2  English 

2  ditto 

lic,  800 

stamp- 

roUs. 

stones. 

small    size 

quarters  per 

tons. 

ers. 

heated    by 
fire. 

working 
hour. 

London 

12  horse  power, 

none 

9     light 

2  pair 

2  pr.  edge- 

4  table  kettles 

i  English 

8  ditto 

but  the  engine 

stamp- 

rolls. 

stones, 

small    size 

quarter  per 

is  used  also  for 

ers. 

used 

used  also 

heated    by 

working 

other  work. 

also  for 
other 
purposes 

for  other 
purposes. 

fire. 

hour. 

HuU 

18  horse  engine, 

none 

3      very 

1  pair 

1  pr.  edge- 

3  double  case 

li  English 

1  ditto 

old   construc- 

heavy 

rolls. 

stones. 

large  size 

quarter  per 

tion. 

stamp- 
ers. 

steam 
kettles. 

working 
hour. 

Ditto 

22  horse  engine 

none 

6     very 
heavy 
stamp- 
ers. 

2  pair 
rolls. 

2  pr.  edge- 
stones. 

6  double  case 
large  size 
steam 
kettles. 

Not  known. 

1  ditto 

1  lb.  oil. 
1  lb.  oil. 
1  lb.  oil. 


**  Rape-seed. — I  have  not  turned  my  attention  to  the  quantity  of  oil  extracted  from  this 
seed ;  but  a  French  crusher  (M .  Geremboret),  on  whom  I  think  one  may  place  consider- 
ible  dependance,  told  me  that 

3f  lbs.  of  best  Cambray  rape-seed  yielded      -  .  - 

3f  —        common  rape-seed  -  -  - 

4|  —  —      poppy-seed  -  -  .  . 

*'  Rape-seed  weighs  from  52  to  56  lbs.  per  imperial  bushel." 
The  following  are  the  heads  of  a  reference  of  machinery  for  a  seed  oil-mill : — 

1.  Two  pairs  of  cast-iron  rollers,  19  inches  long,  and  10  inches  in  diameter,  fixed  in  a 
cast-iron  frame,  with  brasses,  wheels,  shafts,  bolts,  scrapers,  hoppers,  shoes,  &c. 

2.  Two  pairs  of  edge-stones,  7  feet  diameter  each,  with  two  bottom  stones,  6  feet 
diameter  each,  cast-iron  upright  shafts,  sweepers,  wheels,  shafts,  chairs,  brasses,  bolts, 
and  scrapers,  with  driving  spur-wheels,  &,c. 

3.  Five  steam  kettles,  with  wheels,  shafts,  and  brasses,  bolts,  breeches,  and  steam 
pipes,  an  upright  cast-iron  shaft,  with  chairs  and  brasses  at  each  end ;  and  a  large  bevel 
wheel  upon  the  bottom  end  of  upright  shaft,  and  another,  smaller,  upon  fly-wheel  shaft, 
for  the  first  motions. 


OILS,  VOLATILE  OR  ESSENTIAL. 


289 

4  ^^"^s:^^  ^^a^  With  ,0 

^^^^^oT:^:,";:^^  «^^^^  «^-  ^Veli^ell^^l  manufacture  20. 

Oil.  Cocoa-„u,  irni:lf^T,T9to'o:^^^^^^^^  ^^  -re  oi, 

O,^  Olive,  imported  in  1860,  20,784  tuns,  in  1851,  11  488  tun^ 
Oil,  Tra.u.  Blubber,  and  Spermaceti,  imported  in  1850  2iTq  u.       •     ,oc, 
tuns.     For  Seal  Oil,  see  Rkal  Fisiikry.  ^  '  ^^'^^^  *""^  *°  l^^l.  22,219 

OILS,  VOLATILE  OR  ESSENTIAL;  Manufacture  of     Thp  v^io«i      -i 
every  part  of  odoriferous  plants,  whose  aroma  they  dSuse  bMherexhLl'n^'K"'.  ^" 
different  organs  of  different  species.     Certain  plait«»  such  II  thZ!      l  T '   ^"*  "* 
labiat<B,  in  general  contain  volatile  oil  in  all  their  parts     but  oihirJ?   .^f^'^.^^e  ^^ented 
blossoms,  the  seeds,  the  leaves,  the  root,  or  the  K     'it  ^om^^^^^^^^^  -^[  «  ^he 

ent  parts  of  the  same  plant  contain  different  oil«;  •  the  nran!p  fnt  ^^^^^"^  ^J^  ^l^^^' 
three  different  oils,  one  if  which  resides  in  the  flower.  anoThJ^nfh/  ^^""'^^^ 

in  the  skin  or  epidermis  of  the  fruit.  The  ouant^v  nf  nH  ,  •  !  ^T^«».««d  *  thini 
cies,but  alsoin'the  same  plant  4h  The  so^Ia^d  le^^^^^^^^^^^  '^-^ '^ 

countries  it  is  generated  most  profusely  In  several  ^Iffll  '•^^^i™^te  ;  thus  in  hot 
in  peculiar  order,  of  vessels,  which  confine  rso  c  osdv  that  ftdnl',"^'  f  ''  *^""^."^^ 
drying,  nor  is  dissipated  by  keeping  the  plants  for  man/ ye^''    ?n  o^hlT'' •  ^  ^^ 

a^^^Z!^  ^  '-^  contLuallyupon^Ye^:S^ac^^d^%rorat^^ 

^:^  fstirw^ris^tXc;;  ^iianz  JzT.^r.'''  ^^^  ^^^-^  ^«  ^-- 

the  aid  of  the  w'atery  vapour,  at  the^temn^^^^^^  is  volatilized  by 

probably  not  distil  over  Snl'ess  the  heXere  lOOo  moS'  T^^  ""^"^  ^^^^  ''  ^°^ 
explained  in  my  New  Researches  «;.onSL7  publish e^^ih.^h-i  *^""°«^^25i^^  ^^ 
for  1818.    Most  of  the  essential  oil7pmXV?H  :i-  "   ^  I'hilosophical  Transactions 

by  distillation  from  dried  pTan^  only  a  Tw  TucTt'?h '"^  Perfumery  are  extracted 
flower,  are  obtained  from  fresh 'or  succulent  sal  ednla^^^^^  Wi,'^'  \l''  ^^^  ^^«' 
porsof  theoil  and  water  are  conden^T^Tto  hp  m,-F?.  v^^  u^""  l^^  '"''*"^«^  ^ 
still,  the  oil  separates,  and  either  Ss  oi  the  iTfl  ^^'^'^\  ^^^  refrigerator  of  the 
water.     Some/ls  of  a  less  vltIL  nrreTequ^T^^Lr^her^^^^^  1^* 

in  vapor,  and  must  be  dislodged  by  addin-  comLn  salt  lot  ho  i  V*'^f  "**" 
heat  being  augmented  by  15^  ihey  rLdHy  cSme  ov"r  fAr!Vl^^\%"''^^^^^^^  ^« 
water  be  added,  no  oil  will  be'obtabed'X'^aTe  it  is  parthlk  sollff '"^'r'  ^^v^ 
merely  an  aromatic  water  is  oroduced  Tfnn  tL  tl^  k  r  .^  '"  ^^^^'"J  »"d  thus 
plant  may  happen  to  adhere^S^bot\om  of  the  sS^  ^'^i^^  ^'  "^>  ^*^ 

part  an  empyreumatic  odor  to  the  prS     But  af  tL^^ua  ^"^ 

less  upon  the  quantity  employed  than  iinAn  t hit  «r  H  ^  r^  "^^  ^^^""^  distilled  depends 
obvious  that  by^^ivinJaSleVo'rm  t^he  stfl  ,t^^^^^^  ^«.  '^'  "^^-'7^  « 

Hence  the  narrower  and  taller  the  alembic  is,  w  thfn^ertffn  \tu.  T^  ^convenience, 
the  proportion  of  oil  relative  to  that  of  the  aromX  wa?er  fiom  Hk?'  ^•*'''  T^  ^ 
ous  and  vegetable  matter  employed.  Some  place  the  plants  in^iit^^"^'''"'  ""^  *^"^ 
immediately  over  the  bottom  of  the  still  underihe  water  or  Vhov^'^''^''^  '"'^^"^  ^^^^ 
But  the  best  mode  in  my  opinion  is  to  stX«n  imHaht '  r^  '^."''  '^"^^^^  »"  ^^^  steam, 
drive  down  through  them,  s^am  of  any  Sfsir^Zfe  iu  tl^n''  ^""  f  '^'  P^""^^'  ^^  »*> 
further  regulated  by  the  size  of  the  outfet  orificeTeadin..  to  fho'^  ?"*  ^^"^P^i?^"^^  being 
should  be  made  of  strong  copper  tinned  inside  andTn/.l?-  ,1  ^^^^^nser.  The  cylinder 
of  wood,  such  as  soft  deal  or  sycamore.  '  '^  '"  ^^*^  ^^"^^  conducting  specie. 

The  distillation  is  to  be  continued  as  Ion"  as  thp  w«tor  «« 
ance.  Certain  plants  yield  so  little  oil  by  Ihe  ord Wv  rfr  ''  "^''^^  ^^  »  ^'^^Y  appear- 
care,  that  nothing  but  a  distilled  wa^er  is  obta^ned^f  J  1^?'"''  "«twithstanding  every 
be  poured  upon  a  fresh  quantity  of  the  plants  in  thp  .liu  ?'t'  l^^  ^""T  ^^^^'^  «^ 
again  to  be  poured  upon  fresh  plants  •  and  thn«  i  f  ]  '  ^''»''^  ^^'"^  ^^^^^  ^^er,  19 
separated.     This  being  -iken  off,  the  ^turat^  w.t  P^-*^^^^^''  ^*"  ^  '^^^^^^'^  ^^^^^  of  oil'be 

The  refrigeratory  vessd  is  usuallv  ?  worr^  *'  '^^'^^"^  ^«''  *  ^^  distillation, 

whose  temp?ratur7should  be TeSaSv  coll  IftT'T^,?^"^         in  a  tub  of  water, 
fennel,  &c.,  which  become  concfete  at  low  Pmn.l       ^'^u^^'""^  ^^^  «"^  «^  anise-seed 
than  45°  F.  ^""^  temperatures,  the  water  should  not  be  coolw 

2 " 


im-mam 


290 


OILS,  VOLATILE  OR  ESSENTIAL. 


I 


nr 


I  111!  * 


Jil  Ilili 


of  the  flask  Uke  the  spout  of  a  coffee-pot.  The  water  and  the  oil  collected  in  this 
vessel  soon  separate  from  each  other,  according  to  their  respective  specific  gravities ;  the 
one  floating  above  the  other.  If  the  water  be  the  denser,  it  occupies  the  under  portion 
of  the  vessel,  and  continually  overflows  by  the  spout  in  communication  with  the  bottom, 
while  the  lighter  oil  is  left.  When  the  oil  is  the  heavier  of  the  two,  the  receiver  should 
be  a  large  inverted  cone,  with  a  stopcock  at  its  apex  to  run  off  the  oil  from  the  water 
when  the  separation  has  been  completed  by  repose.  A  funnel,  having  a  glass  stopcock 
attached  to  its  narrow  stem,  is  the  most  convenient  apparatus  for  freeing  the  oil  finally 
from  any  adhering  particles  of  water.  A  cotton  wick  dipped  in  the  oil  may  also  serve 
the  same  purpose  by  its  capillary  action.  The  less  the  oil  is  transvased  the  better,  as  a 
portion  of  it  is  lost  at  every  transfer.  It  may  occasionally  be  useful  to  cool  the  distilled 
water  by  surrounding  it  with  ice,  because  it  thus  parts  with  more  of  the  oil  with  which  it 

is  impregnated. 

There  are  a  few  essential  oils  which  may  be  obtained  by  expression,  from  the  sub- 
stances which  contain  them ;  such  as  the  oils  of  lemons  and  bergaraot,  found  in  the 
pellicle  of  the  ripe  fruits  of  the  citrus  aurantium  and  medica ;  or  the  orange  and  the 
citron.  The  oil  comes  out  in  this  case  with  the  juice  of  the  peel,  and  collects  upr*  its 
surffl-CC 

For  collecting  the  oils  of  odoriferous  flowers  which  have  no  peculiar  organs  for  impri- 
soning them,  and  therefore  speedily  let  them  exhale,  such  as  violets,  jasmine,  tuberose, 
and  hyacinth,  another  process  must  be  resorted  to.  Alternate  layers  are  formed  of  the 
fresh  flowers,  and  thin  cotton  fleece  or  woollen  cloth-wadding,  previously  soaked  in  a  pure 
and  inodorous  fat  oil.  Whenever  the  flowers  have  given  out  all  their  volatile  oil  to  the 
fixed  oil  upon  the  fibrous  matter,  they  are  replaced  by  fresh  flowers  in  succession,  till  the 
fat  oil  has  become  saturated  with  the  odorous  particles.  The  cotton  or  wool  wadding  be- 
ing next  submitted  to  distillation  along  with  water,  gives  up  the  volatile  oil.  Perfumers 
alone  use  these  oils;  they  employ  them  either  mixed  as  above,  or  dissolve  them  out  by 
means  of  alcohol.  In  order  to  extract  tlie  oils  of  certain  flowers,  as  for  instance  of  white 
liiies,  infusion  in  a  fat  oil  is  suflicient. 

Essential  oils  differ  much  from  each  other  in  their  physical  properties.     Most  of  them 
are  yellow,  others  are  colorless,  red,  or  brown ;  some  again  are  green,  and  a  few  are  blue. 
They  have  a  powerful  smell,  more  or  less  agreeable,  which  immediately  after  their 
distillation  is  occasionally  a  little  rank,  but  becomes  less  so  by  keeping.    The  odor  is 
seldom  as  pleasant  as  that  of  the  recent  plant.     Their  taste  is  acrid,  irritating,  and  heating, 
or  merely  aromatic  when  they  are  largely  diluted  with  water  or  other  substances.     They 
are  not  greasy  to  the  touch,  like  the  fat  oils,  but  on  the  contrary  make  the  skin  feel 
Toagh.    They  are  almost  all  lighter  than  water,  only  a  very  few  falling  to  the  bottom  of 
this  liquid;    their  specific  gravity  lies  between   0*847  and  1-096;    the  first  numbei 
denoting  the  density  of  oil  of  citron,  and  the  second  that  of  oil  of  sassafras.    Although 
styled  volatile  oils,  the  tension  of  their  vapor,  as  well  as  its  specific  heat,  is  much  lest 
than  that  of  water.    The  boiling  point  difi'ers  in  different  kinds,  but  it  is  usually  about 
316*  or  320®  Fahr.     Their  vapors  sometimes  render  reddened  litmus  paper  blue,  although 
Jhey  contain  no  ammonia.     When  distilled  by  themselves,  the  volatile  oils  are  partially 
decomposed ;  and  the  gaseous  products  of  the  portion  decomposed  always  carry  off  a  little 
of  the  oil.     When  they  are  mixed  with  clay  or  sand,  and  exposed  to  a  distilling  heat,  they 
are,  in  a  great  measure  decomposed  ;  or  when  they  are  passed  in  vapor  through  a  redhot 
tul^,  combustible  gases  are  obtained,  and  a  brilliant  porous  charcoal  is  deposited  in  the 
tube.     On  the  other  hand,  they  distil  readily  with  water,  because  the  aqueous  vapor 
formed  at  the  surface  of  the  boiling  fluid  carries  along  with  it  the  vapor  of  the  oil  produ- 
ced in  virtue  of  the  tension  which  it  possesses  at  the  2 1 2th  degree  Fahr.     In  the  open 
air,  ,the  volatile  oils  burn  with  a  shining  flame,  which  deposites  a  great  deal  of  soot.     The 
congealing  point  of  the  essential  oils  varies  greatly ;  some  do  not  solidify  till  cooled  below 
32°,  others  at  this  point,  and  some  are  concrete  at  the  ordinary  temperature  of  the  atmos- 
phere.    They  comport  themselves  in  this  respect  like  the  fat  oils ;  and  they  probably  con- 
sist, like  them,  of  two  different  oils,  a  solid  and  a  fluid ;  to  which  the  names  stearoptene 
and  ekoptenej  or  stearessence  and  oleiessence,  may  be  given.    These  may  be  separated 
from  each  other  by  compressing  the  cooled  concrete  oil  between  the  folds  of  porous  paper ; 
the  stearessence  remains  as  a  solid  upon  the  paper ;  the  oleiessence  penetrates  the  paper, 
and  may  be  recovered  by  distilling  it  along  with  water. 

When  exposed  to  the  air,  the  volatile  oils  change  their  color,  become  darker,  and 
gradually  absorb  oxygen.  This  absorption  commences  whenever  they  are  extracted 
from  the  plant  containing  them ;  it  is  at  first  considerable,  and  diminishes  in  rapidity  as 
it  goes  on.  Light  contributes  powerfully  to  this  action,  during  which  the  oil  disengages 
a  little  carbonic  acid,  but  much  less  than  the  oxygen  absorbed ;  no  water  is  formed. 
The  oil  turns  gradually  thicker,  loses  its  smell,  and  is  transformed  into  a  resin,  which 
becomes  eventually  hard.  De  Saussure  found  that  oil  of  lavender,  recently  distilled, 
had  absorbed  in  four  winter  months,  and  at  a  temperature  below  54°  F.,  52  times  its 


OILS,  VOLATILE  OR  ESSENTUL.  291 

volume  of  oxygen,  and  had  disengaged  twice  its  volume  of  carbonic  acid  ca*^.  „„r  w. 
It  yet  completely  saturated  with  oxveen      THp  Kf*.«r«oJl.7^  wtruumc  acia  gases;  nor  was 
its  liquefying  temperature,  in  the  spfS^of  two  vear^  i '^     °^  amse-seed  oil  absorbed  at 
and  disengaled  2I  times  itsVolSmfoT  trZ^:":uf,:'^ZV^^^^  ^ 

experience  such  an  oxydizement  is  composed  of  a  resin  dTs'solv^  in  t^pin.],  L^f^  *2 
the  0,1  may  be  separated  by  distilling  the  solution  a WwTh^^t^^^^  7wl/^  ^'^'-i*?^ 
an  unchanged  state,  they  must  be  put  in  vials,  medtl^eZcLJZ-^l^^^'^f  "* 
stopples,  and  placed  in  the  dark.  ^°P'  ''^''^^  ^'^  ^"»"°d  B^^ 

Volatile  oils  are  little  soluble  in  water,  yet  enoueh  so  as  in  ;m„-.^  «  •.  v 
their  characteristic  smell  and  taste.  The  water  whkh  distL  w.T«l  I^-^^  ^'^*'°^ 
a  saturated  solution  of  it,  and  as  such  is  used  in  medicine  u^dpr  ti^  """^  ''  !?F"."^ 
water.  It  often  contains  ither  volatile  substances  Tonta^I'd  in  the  lH^'  'J  ^'"''^^"^ 
apt  to  putrefy  and  acquire  a  nauseous  smeU  when  kept  in  nerfertlv  nn?C^  1'  f  ^"^  ^^l"""^  '^ 
vessels  partially  open,  these  parts  exhale,  and  the  water 'remaps  sweet  ¥l?'  ^T  ^ 
however,  which  are  made  by  agitating  volatile  oU  with  simnlf distill  J  wL  ^  '^*^^"' 
to  spoil  by  keeping  in  well-corked  bottles.  ^       ''^"^^  ^*^^''  "«  >»ot  apt 

The  volatile  oils  are  soluble  in  alcohol,  and  the  morp  sn  ti.«  o#.^ 
Some  volatile  oils,  devoid  of  oxygen,  such  as  the  ofls  of  ^»^P«rn  "/^  ^^^  'P^^*  «• 
sparingly  soluble  in  dOute  alcohol ;  while  the  ol  of  lavendernennp/  """^"^  ""  ^^^ 
bly  so.  De  Saussure  has  inferred  from  his  experiments  that  thfl^^^^  *'^  considera- 
soluble  in  alcohol,  the  more  oxygen  they  coS  Such  cn-^^  volatile  oils  are  the  more 
ous  spirits  which  the  perfumers  incoiTectircalTwatertsZ^T''"/  '^"^  **!f  ^°""'"- 
eau  <k  jasmin,  &c.    They  become  turbid  by  aSurl^fwaZ^^^^^^^  1'  ^^'^«^' 

and  sepan^tes  the  volatile  oils.    Ether  also'^t'Sy  hTes"^^^^^  ^'^  ^^^^»»^^' 

These  oils  combine  with  several  vegetable  acid*?  ^urh  \lt^^        .•      ^ 
succinic,  the  fat  acids  (stearic,  margariJ/ok  c)  the  ^.aTnhnr      ^T'^^^  '^^^^^^  ^^'^ 

With  the  exception  of  the  oil  of  cK  the  voS^^^^^ 
salifiable  bases.    They  have  been  naXm?  In^  J^      •  ?'*  ^"^  not  combine  with  the 
of  Starkey's  soap.'  T^fL  preparST/t^^^^^^^ 

mortar,  with  a  litth  oU  of  turpentine  Jdeddr^^^^^^  fused  caustic  soda  in  a 

the  consistence  of  soap.    T^mZ^S^^^^^^^  fZ^'-  ^^^  f^.^  "^^^""'^  ^as  acquired 

distilled.     What  remains  after Te^spWt  s  dJ^J^Tff'"^  '°  f"^}^  ^i^^"^'  ^^'^'^^  «°d 
resin  formed  in  the  oil  during  the  actTtr/tl^lT   ^'  '"^'''''  "^  ''^^  '^'^^^'''^  ^^^^  « 

buutttftvVndLlrbr^T  tt:;'  ^^^  °'  ^'''^  ^^^  ^-  ^"^^  ^^  --omacal  gas; 

dissolved  in  volatile  oil.  This  fraud  mav  ^  dete-^H^  />  '^'T'  «^»>^^^«°^  of  capiv, 
and  exposing  it  to  heat.     A  di^  ess^ntmTnii  I  ^""'".^  *  ^™P  «^  ^^^  «»1 «»  P^Per, 

Whilst  Z  oil  mix^  wUh  anv  oT thP Thnv!^  oil  evaporates  without  leaving  any  residu,^^ 
paper.  If  fat  oU  beTresent^  it  wUl  remlfn'"^-^"?'  l^^""^  *  translucent  stain  uiK,n  tS 
Ual  oil  with  thrice  its  vnlnml  !!rT  •  vT"  ""^^^^olved,  on  mixing  the  adulterated  essen- 
mixed  with  vSe  oil  ie^si'v  of  specific  gravity  0-840.     Resinous  matter 

^^^^irlsZbles     H^^^^^^^^  the  presence  of  a  cheap  essenti;i  oil  in  a  dear  one, 

the  suspectZa  :;e  t^b^  pour^^  uCn  a"b^  0?".^  ^T^'  ^"''^-  ^  ^'^  <*-p'' ^ 
and  smelled  to  from  time  to  tZe     Tthfc  ^^^'  '^^'^^.^"  ^°  ^^  ^^^'^^^  i»  the  air, 

of  the  oil  which  exhaks  at  th.  k.„?"  •^''  "^^J  "^^  may  succeed  in  distinguishing  the  odo^ 
which  serves  perfectlv  to  dp  p..  ?  r"!"^'  ^"^  ^^^'  '^^'''^  ^^^^^^  »t  the  end;  a  meUlS 
when  the  deba'sX^'is  mlf^'wUhtS^^^^^  '"  I''  ^""  ^^^"^'^^  ''^''  Mo~ 
remains  in  a  great  me^suTe  u1d7s  olveT  I?  aro^  '^^  ^'.l^'^^^^  '^'  «'^  «^  '^'^^^'^^^ 
than  water,  be  mixed  thev  mo  v  Ko  J  ,  u     '^  ^^^^'^^  ^^^"  ^^^er,  and  an  oil  lighter 

and  then  leaving  the  mfcat^est  ^^r'"^.**!  T*''^"  ^  ^'"^  ''^^  "^'^'^  that  liquiS^ 
ful  examination  V  thrje'pVctiv^dens^Uer       '''  "^'^'^'^  be  distinguished  by  o  c\t^ 

bland  oil  hafbe"^^^^^^^  f ^^ "^  ^'^  '/"^^  ^^^"'^  ^-^^^  ^-^  whicu  .he 

steam,  as  it  passes  up^Ihrou J^the  hrli";  ^'  ''T'  °^  '^f'"*"  ''''^^  ^'^hin  the  still.  The 
and  condenses  along  with  it  in  the  worm  Th  ^7'"^^^".'  '^"^^^  ^"'^t^  ^^^^^ile  oil, 
falls  to  the  bottom  of  the  water  hasTo  ^;n.  ^  °j'  '''^'''^  ^^'  ^^'"^^  ^^e'"'  «"d  which 
tke  cyanogen  gas  than  hvdrocy^nror  nr.?^^"^  ^f  Penetrating  a  smell,  that  it  is  more 
It  is  heavier  than  waterrwhirmuch  dilnJpd^'-^'K  ^^''  ""  ^^'  *  ^«»^^"  y^»°^  <=o^^ 
burnin.  taste.  When  ex^sed  ?o  The  air  h  Ik  k^^'  ^"  agreeable  smell,  and  a  bitte; 
tals  of  benzoic  acid.     ThiVoiT  consist  A^*  f'^^  ''/^^^'^*  *"^  ^^ts  fall  a  heap  of  crys- 

contains  hydrocyanic  acid,  aid  ?sSnn.*  "^'T'^  f^"^""  *^"^5  one  of  which  is  volatUe, 

acia,  and  is  poisonous ;  the  other  is  less  volatile,  is  not  poisonou^ 


u  t. 


292 


OILS,  VOLATILE  OR  ESSENTIAL. 


OILS,  VOLATILE  OR  ESSENTIAL. 


I 


iii'^ 


absorbs  oxygen,  and  becomes  benzoic  acid.  If  we  dissolve  100  parts  of  the  oil  of 
bitter  almonds  in  spirit  of  wine,  mix  with  the  solution  an  alcoholic  solution  of  potash, 
and  then  precipitate  the  oil  with  water,  we  shall  obtain  a  quantity  of  cyanide  of  pot- 
ash, capable  of  producing  22^  parts  of  prussian  blue.  Oil  of  bitter  almonds  combines 
with  the  alkalis.  Perfumers  employ  a  great  quantity  of  this  oil  in  scenting  their  soa|>8. 
One  manufacturer  in  Paris  is  said  to  prepare  annually  8  cwt  of  this  oil.  A  similai 
poisonous  oil  is  obtained  by  distilling  the  following  substances  with  water:  the  leaves 
of  the  peach  {amygdalus  persica),  the  leaves  of  the  bay-laurel  (prunw  lauro-cerams), 
the  bark  of  the  plum  tree  {prunus  padns),  and  the  bruised  kernels  of  cherry  and  plum- 
stones.  All  these  oils  contain  hydrocyanic  acid,  which  renders  them  poisonous,  and 
they  also  generate  benzoic  acid,  by  absorbing  oxygen  on  exposure  to  air. 

Oil  of  bitter  almonds,  in  the  crude  state,  consists  of  hydruret  of  benzoyle,  hydrocyanic 
acid,  benzoic  acid,  and  benzoine.  The  two  first  constituents  are  essential  ones ;  the  othew 
being  accidental,  and  the  result  of  spontaneous  reactions. 

The  hydruret  of  benzoyl  when  pure  is  colourless,  transparent,  of  spec.  grav.  1  -043  ; 
and  though  it  possesses  the  almond  flavour,  is  not  poisonous ;  it  ought  to  form  85  to  90 
per  cent  in  volume  of  the  crude  oil  When  oil  of  vitriol  is  mixed  with  that  essential  oil, 
it  merely  gives  it  a  dark  reddish  brown  colour,  but  does  not  decompose  it.  If  the  said 
hydruret,  however,  be  exposed  to  the  air,  it  becomes  oxidized,  and  by  the  substitution  ot 
one  atom  of  oxygen  for  one  of  hydrogen,  it  is  transformed  into  benzoic  acid ;  a  com- 
pound often  present  in  oil  of  bitter  almonds.  This  acid  is  not  coloured  by  oil  of  vitriol 
Benzoine  when  present,  however,  forms  a  violet  coloured  compound  with  sulphuric  acid. 

Hydrocyanic  acid  sometimes  is  present  to  the  extent  of  8  or  10  per  cent,  in  crude 
oil  of  bitter  almonds,  rendering  the  mixture  poisonous. 

To  detect  alcohol  in  oil  of  bitter  almonds,  nitric  acid  of  specific  gravity  1*42  may 
be  employed,  as  I  did  in  testing  for  alcohol  in  wood  spirit.*  If  the  oil  be  free  from 
alcohol,  no  immediate  action  occurs,  but  in  the  courae  of  3  or  4  days  crystals  of  benzoic 
acid  begin  to  appear,  and  eventually  occupy  the  whole  bulk,  giving  a  bright  emerald 
green  colour :  this  quiet  reaction  is  very  characteristic.  But  if  alcohol  to  the  amount 
of  8  or  10  per  cent,  be  present,  a  violent  eflfervescence  ensues  in  a  few  minutes  after 
pouring  in  the  nitric  acid,  with  the  disengagement  of  nitrous  fumes.  By  using  nitric  acid 
of  1*5  a  very  small  proportion  of  alcohol  may  be  recognized. 

Essential  oil  of  bitter  almonds,  free  from  adulteration,  should  have  a  specific  gravity 
at  most  of  1*52. 

When  the  crude  oil  of  bitter  almonds,  and  a  mixture  of  milk  of  lime  and  protochlo- 
ride  of  iron  are  all  agitated  together,  and  subjected  to  distillation  at  a  gentle  heat,  the 
product  is  an  oil  of  bitter  almonds  free  from  hydrocyanic  acid. 

OU  estential  of  bitter  almonds.  To  determine  whether  the  pure  oil  of  bitter  almonds, 
(hydruret  of  benzoyle)  be  poisonous  or  not,  Mr.  G.  D.  Grindley,  of  the  Pharmaceutical 
school,  made  the  following  researches.  He  at  first  adopted  the  usual  plan  for  removing 
the  hydrocyanic  acid,  by  distilling  the  commercial  oil  of  almonds  with  a  mixture  of  proto- 
chloride  of  iron  and  lime ;  the  product  was  still  contaminated  with  the  acid,  and  several 
repetitions,  conducted  with  every  precaution,  were  attended  with  no  better  success.  He 
then  adopted,  by  the  suggestion  of  Professor  Redwood,  the  following  method,  which 
proved  most  satisfactory.  The  oil  was  mixed  with  an  equal  quantity  of  water,  and 
digested  in  a  water  bath  with  red  oxide  of  mercury,  and  small  quantities  of  lime  and 
protochloride  of  iron ;  time  having  been  allowed  for  the  decomposition  of  the  acid  the 
whole  was  introduced  into  a  copper  retort  on  account  of  the  jumpmgs  during  distillation. 
The  product  consisted  of  pure  hydruret  of  benzoyle,  while  bicyanide  of  mercury,  benzoate 
of  lime,  chloride  of  calcium,  and  oxide  of  iron,  remained  in  the  retort,  with  benzoyne 
and  an  excess  of  the  ingredients  employed.  The  process  is  founded  upon  the  strong 
affinity  which  exists  between  mercury  and  cyanogen,  so  that  when  binoxide  of  mercury 
and  hydrocyanic  acid  are  digested  together,  they  are  decomposed,  bycanide  of  mercury 
and  water  being  formed-  The  protochloride  ot  iron,  which  with  the  lime  yields  pro- 
toxide, is  introduced  to  prevent  the  formation  of  benzoic  acid  from  the  oxidation  of 
the  oiL  For  the  same  reason  care  should  be  taken  to  conduct  the  process  with  as  little 
access  of  air  as  possible.  The  oil  thus  procured  was  pure  and  colourless.  No  trace  of 
nitrogen  could  be  detected  by  Lassaigne's  test,  which  he  found  to  be  exceedingly  delicate, 
affording  indications  of  the  presence  of  that  body  in  extremely  minute  quantities  of 
morphia,  narcotine,  Ac.  This  test  consists,  in  adding  to  a  very  small  quantity  of  the 
substance  to  be  tested,  in  a  small  German  glass  tube,  a  fragment  of  potassium  about 
the  size  of  a  millet  seed,  and  heating  the  tube  over  the  fiame  of  a  spirit  lamp,  till  the 
organic  substance  is  entirely  carbonized.  The  carbonaceous  residue  is  treated  with  cold 
water,  and  to  the  clear  decanted  liquor  a  drop  of  a  solution  containing  the  mixed  two 
oxides  of  iron  is  added.    A  dirty  green  precipitate  is  immediately  formed,  which  if  nitro- 

*  See  the  pamphlet,  Rtvtttue  i»  Jeopardf. 


293 

fcTd^^irpure  ^Wi",""' >r^^i  ^.'"^'  t".*^«  '^^'^'^^^  of  a  drop  of  hydrochloric 
health  or  pfrl  ltte.^trd"o^l"Ll  b'^^V"^  without  injurious^ffec^t  on  thSJ 
of  Messrs.  Ked  wood  and  Cu^Zey  ^«  always  purified  by  this  valuable  proceaa 

It  concretes  in  I^it?™,^  "'J^'^l  l^^^'eT^'"'  7f  ^^  ^^^^  «^^^«  ^^' 
heated  to  64°  nearly.  ltsl,e<^fif  ^li^^^l%%,^' ^^^ ^  »% -^^^  again  till 
S  1^  'J'J'^J^l^^oponions  in  alcohol  of  0-806;  but  only  to  the  extent  JrVo^^*  .  ^-  "^  f^^ 
hoi  of  0-84.  When  it  becomes  resinous  by  long  expos^e  trth.  Jr  ^?  T  ""T'  '"  ^^ 
ing  properly.  It  consists  of  two  oils  ;  a  solid  stearessen^e  ln<^  «  r  '-i'  ''?^'  '^  ''''''^^^' 
may  be  separated  by  compression  of  the  cold  concrete  oh'  "^      oleiessence,  which 

Uu  of  bergamot  is  extracted  by  pressure  from  the  rind  nf  tho  ,.v    r    -.    ^   .      . 
hergamium  and  aurarUium.    It  is  a  limpid,  yellowish  flu  dhavJncf  ^"^  n  "'*  ""^  *^^  "^"^ 
of  oranges.     Its  specific  gravity  varies  from  oS  to  C^^5^^^^^^^^  resembling  that 

cooled  a  little  below  32°.  *      '^  b-comes  concrete  when 

OUofcajeput  is  prepared  in  the  Moluccas,  by  distillin*'  the  drv  u^rr^   r  *i. 
leucadendron.      Cajeput  is  a  native  word,  si  Jifyinf  m^^^^^^^^  themelaleuca 

green ;  it  has  a  burning  taste,  a  strong  smell  of  camnhSrtfrtnT^'^^  ^T'  T^'^  °"  " 
very  fluid,  and  at  48o  has  a  specific  gravi^of  0-9^  Thp  .  i^  ^'"^'  *"?  '^'^^"^-  ^^  " 
the  copper  vessels  in  which  it  is  imported  so  thnV?;  -J  ^^^o'"  seems  to  be  derived  from 
which  also  separates  the  oil  ntoTwrsom'^L^e  fi  /^^^^^^  ^'  ^^^^'"f '°^  ^^^^  ^^'^> 
cf  0^897,  the  last  of  0-920.     This  hasT^r^en  color  '''^''  ^'^^^"^  *  ^^""'^^ 

the  aiminum  cyminnm  (cumin)  afford  an  Sfl  simn«?t    fif  ^'^'''^  '^  ^'^^-     *"»«  se^s  of 
Its  specific  gravity  is  0-975  ""'^"  ^"^  the  preceding,  but  not  so  agreeable. 

ounce  of  oil  of  lemons  be  added  to  3  rund,  of  ^hi^'f  ^k"""^"  ^^  "'^"^"°'^^-     ^^  « 
readily  from  the  adhering  water  ^        '  ""^  ^^'^  '''^'  ^^^^  "^^^  it  separate  more 

the^MowJng  ^lantsTSn  fhaltE  j:l:!!:^?T:i}'^^  ^^^^^^  ^^  ^^^^^ 

and  those  of  iilfoil  (achilLamSH^^ThT^    »t''"^'  ^^^  ^°^^"  of  arnica  rmmtarl 

Oil  of  cinnamon  is  extraTt^T  di.  hL"      r  ^^'*  ^\*  T""'  ^'^'''  ^^  0-852.  ^ 

It  is  i^oduced  chieflVrcl^on'^trt^^^^^^^  of'^ba^k'V/fi/f'  ''"""^  cinnamomun. 

distilled  over  with  difficultv  and  th^  «.««  pieces  oi  bark  unfit  for  exportation.  It  is 
and  the  use  of  a  low  st^^  It  his  atTst  a  'Lr^n"^  by/he  addition  of  salt  wate^ 
with  age.     It  possesses  in  a  h  gh  de^ee  St^^^^^^^  '  •^°''  ^"'  ''  ^^^«°^^«  ^r«^« 

smell  of  cinnamon.  It  is  he^v^er  thfnl.«/  •!  ^^^^^t  burning  taste,  and  the  agreeable 
cretes  below  32°  F.,  anrdoesTot  fuse  a^^^^  %T"\^'.  ^^^1'^  ^^^°^  ^'^^^'  It  con! 
soluble  in  water,  and  when  a^ut  J  with  k  Ld\    '^'^  '**  ^['      ^' ''  ^^^  sP»"ngly 

abundantly  in  alcohol,  and  comwiTs  with  ammonk  into'T'" '  '^'  ''^'''  ^'  ^'^^^'^^-' 
on  exposure  to  air.  "^  ammonia  into  a  viscid  mass,  not  decomposed 

regZrcollr'ss'or^ydW^^^^  a  stearessence  in  large 

gentle  heat  into  a  colorlesi  iS  whth  .r^?^r^  pulverized,  and  which  melt  at  a  very 
mediate  between  thatTf  cinnamon^ nd  f  ^^  f "»^«^«»  'tooling.  It  has  an  odor  inter^ 
wards  bm.in,  and  arLatfc""  1^^,!  be^^e^^^^  T\^'  ^'''  ^'^-^y>  ^-^  -^el 

.ctt?%f  if  ilUl'ofy'eS^^  ?"  1"^  «°^"  ^l^^^of  the  caryopkyUus  aromat. 

taste.  Its  specific  gmvity  fs  Tofi i  I  •  "^''^^^^/^ell  of  the  cloves,  and  a  burnin- 
difficult  to  distil.  A^t  thfend  of  a  certain  t^me^t  d'/  ''!  ^'^'  ^^^^^"^  ^"^>  ^^^  ^he  most 
similar  stearessence  is  obtained  bv  Sn^  \T  I  °^Pf  ^^^s  a  crystalline  concrete  oil.  A 
solution  cool.  The  crystals  thSs  f^^^^^  ar/h  -1^  '^^ '  ^'"  "^*^«^«'>  ^"^  '^tling  thi 
out  taste  and  smell.  Oil  of  cloveSlem^rW  .^"l"'  "^^'^f'  §^'^"P^  ^»  ^»«t>»J«^'  ^'ith- 
alcohol,  ether,  and  acetic  acid  It  d^f J^f '^^|M?^^^^'°'<^^  properties.  It  dissolves  in 
even  when  exposed  to  that  cold  for  ^t.  °  i  f^'^'^^  ^\^  temperature  of  4°  under  (y>  F.. 
green,  then  brown,  and  turns  resinous  Ntr''''"'-:i  ^\  ""^^'^^  ^^'*^""e  gas,  becomes 
converts  it  into  oxalic  acid.  If  mix^  w  d  T^  """^^^  '^  '^'  *"<^  »^  Sealed  upon  it, 
sulphuric  acid,  an  acid  liquor  is  fomed  at  wL^'oI  Sff ^'  "^''^  ?"%*^^'?  "^  '''  ""'''^^^  oC 

urmea,  at  whose  bottom  a  resm  of  a  fine  purple  color  is 


iH 


- 


m 


3^4  OILS.  VOLATILE  OR  ESSENTIAL. 

found  After  being  washed,  this  resin  becomes  hard  and  brittle.  Alcohol  dissolves  it, 
and  tkket  a  red  color ;  and  water  precipitates  it  of  a  blood  red  hue.  It  dissolves  also  m 
ether  When  we  agitate  a  mixture  of  strong  caustic  soda  ley  and  oil  of  cloves  in  equal 
^rts;the  mass  thickens  very  soon,  and  forms  delicate  lamellar  crystals.  If  ^^^^^^^P^"; 
water  upon  it,  and  distil,  there  passes  along  with  the  water,  a  small  quantity  of  an  oil 
which  differs  from  oil  of  cloves  both  in  taste  and  chemical  properties.  ,P"""f  *J«-^*;.°*; 
ine  the  liquor  left  in  the  retort  lets  fall  a  quantity  of  crystalline  needles,  which  being 
separated  by  expression  from  the  alkaline  liquid,  are  ^Imost  inodorous,  but  possess  an 
alkaline  taste,  joined  to  the  burning  taste  of  the  oil.  These  crystals  '^fl"i'^e/«r^sduli°^ 
from  10  to  12  parts  of  cold  water.  Potash  ley  produces  similar  effects.  Ammonmcal 
^8  transmitted  through  the  oil  is  absorbed  and  makes  it  thick.  The  concrete  combina- 
Son  thus  formed  remains  solid  as  Ion-  as  the  vial  containing  it  is  corked,  but  when  open- 
ed,  the  compound  becomes  liquid ;  and  these  phenoniena  may  be  reproduced  as  many  times 
as  we  pleasV^  Such  combinations  are  decomposed  by  acids,  and  the  oil  set  at  liberty  has 
SJe  same  taste  and  smell  as  at  first,  but  it  has  a  deep  red  color.  The  alkalis  enable  us 
to  detect  the  presence  of  other  oils,  as  that  of  turpentine  or  sassafras,  i^/hat  of  cloves 
because  they  fix  the  latter,  while  the  former  may  be  volatilized  with  water  by  distilling 
the  mixture.  The  oil  of  cloves  found  in  commerce  is  not  pure,  but  contains  a  mixture  of 
the  tincture  of  pinks  or  clove-gillyflowers,  whose  acrid  resin  is  thereby  introduced.  U 
is  sometimes  sophisticated  with  other  oils. 

The  oil  of  elder  is  extracted  by  distillation  from  the  flowers  of  the  satnbucw  nigra.  It 
has  the  consistence  of  butter.    The  watery  solution  is  used  in  medicine. 

Oil  of  fennel  is  extracted  by  distillation  from  the  seeds  of  the  anethum  f<BniaiIum,     It  is 
either  colorless  or  of  a  yellow  tint,  has  the  smell  of  the  plant,  and  a  fecific  gravity  of 
0-997.     When  treated  with  nitric  acid,  it  affords  benzoin.      It  congeals  at  the  tempera- 
lure  of  14»  F.,  and  then  yields  by  pressure  a  solid  and  a  liquid  oil ;  the  former  appearing 
in  crystalline  plates.    It  is  used  in  this  country  for  scenting  soap. 

Oils  of  fermented  liquors.  The  substances  usually  fermented  contam  a  small  quantity 
of  essential  oils,  which  become  volatile  along  with  the  alcoholic  vapors  in  distillation, 
and  progressively  increase  as  the  spirits  become  weaker  towards  the  end  of  the  process. 
The  vapors  then  condense  into  a  milky  liquor.  These  oils  adhere  strongly  to  the 
alcohol,  and  give  it  a  peculiar  acrid  taste.  Thev  differ  according  to  the  vinous  wa»h 
from  which  they  arc  obtained,  and  combine  with  greater  or  less  facility  with  caustic 

^*^0t7  of  {train  spirits.    At  the  ordinary  temperature  it  is  partially  a  white  solid ; 
when  cooled  lower  it  assumes  the  aspect  of  suet,  and  therefore  consists  chiefly  of  stear- 
essence.     Its  taste  and  smell  are  most  offensive;  it  swims  upon  the  surface  of  water, 
and  evin  of  spirit  containing  30  per  cent,  of  alcohol.     It  sometmies  derives  a  green 
color  from  the  copper  worm^"  of  the  stUl.     When  heated   it  fuses  and  turns  yellow 
When  it  has  become  resinous  by  the  a-ency  of  the  atmosphere,  it  gives  a  greasy  stain  to 
paper      It  dissolves  in  6  parts  of  anhydrous  alcohol,  and  i"  two  of  ether ;  and  is  sa^  o 
?rystalUze  when  the  spirit  solution  has  been  saturated  with  it  ^«t^«"dl^a  lowed  to 
cool.     By  exposure  to  a  freezing  mixture,  the  whiskey  which  contains  it  lets  U  fall. 
Caustic  potash  dissolves  it  very  slowly,  and  i>ms  a  soap  so  uble  in  60  parts  of  water 
It  is  absorbed  by  wood  charcoal,  and  still  better  by  bone  black ;  whereby  it  may  be  corn- 
pletely  abstractii  from  bad  whiskey.     According  to  Buchner,  another  oil  ^^y  also  be  ob- 
teined  from  the  residuum  of  the  second  distillation  of  whiskey  if  saturated  with  sea  salt 
and  again  distilled.    Thus  we  obtain  a  pale  yellow  fluid  oil,  whicli  does  not  concrete  wilh 
cold,  possessed  of  a  disagreeable  smeU  and  acrid  taste.    Its  specific  gravity  is  0-835.     It 

is  soluble  in  alcohol  and  ether.  ,.^  ^  .  ,.^       . 

2.  The  oil  from  potato  spirits  has  properties  quite  different  from  the  preceding.  t 
IS  obtained  inconsiderable  quantity  by  continuing  the  distillation  a^^^^^^/^  ^f,  ^*|f  .**" 
cohol  has  come  over,  and  it  appears  in  the  form  of  a  yellowish  oil,  mixed  with  water 
and  spirits.  After  being  agitated  first  with  water,  then  with  a  strong  solution  of  mu- 
riate of  lime,  and  distilled  afresh,  it  possesses  the  following  properties ;  it  is  colorless 
limpid,  has  a  peculiar  smell,  and  a  bitter  hot  taste  of  considerable  permanence.  It 
leaves  no  greasy  stain  upon  paper,  remains  liquid  at  0°  F.,  but  cooled  below  that  point 
t  crysrallizes  Uke  oil  of  anise-seed.  When  pm-e  it  boils  at  257°  F.;  but  at  a  lower 
degree,  if  it  contains  alcohol.  Its  specific  gravity  is  0-821,  or  0-823  when  it  contains  a 
little  water.  It  burns  wilh  a  clear  flame  without  smoke,  but  it  easily  goes  out,  il  not 
burned  with  a  wick.  It  dissolves  in  smaU  quantity  in  water,  to  which  it  imparts  us 
taste  and  the  properties  of  forming  a  lather  by  agitation.  It  dissolves  m  all  proportions 
in  alcohol.  Chlorine  renders  it  green.  Concentrated  sulphuric  acid  converts  it  into  a 
crimson  solution,  from  which  it  is  precipitated  yellow  by  water.  It  dissolves  m  all  pro- 
Dortions  in  acetic  acid.  Concentrated  caustic  leys  dissolve  it,  but  give  it  up  to  water.  11 
does  not  appear  to  be  poisonous,  like  the  oil  of  corn  spirits;  because,  when  given  by 
spoonfuls  to  dogs,  it  produced  no  other  effect  but  vomiting. 


OILS,  VOLATILE  OR  ESSENTIAL. 


295 


3.  The  oil  of  brandy  or  grape  spirits  is  obtained  during  the  distillation  of  the  fermented 
residuum  of  expressed  grapes ;  being  produced  immediately  after  the  spirituous  liquor 
has  passed  over.  It  is  very  fluid,  limpid,  of  a  penetrating  odor,  and  an  acrid  disagree- 
able taste.  It  grows  soon  yellow  in  the  air.  When  this  oil  is  distilled,  the  first  portions 
of  it  pass  unchanged,  but  afterwards  it  is  decomposed  and  becomes  empyreumatic.  It  dis- 
solves in  1000  parts  of  water,  and  communicates  to  it  its  peculiar  taste  and  smell.  One 
drop  of  it  is  capable  of  giving  a  disagreeable  flavor  to  ten  old  English  gallons  of  spirits. 
It  combines  with  the  caustic  alkalis,  and  dissolves  sulphur. 

Oil  of  jumper  is  obtained  by  distilling  juniper  berries  along  with  water.  These  should 
be  bruised,  because  their  oil  is  contained  in  small  sacs  or  reservoirs,  which  must  be  laid 
open  before  the  oil  can  escape.  It  is  limpid  and  colorless,  or  sometimes  of  a  faint 
greenish  yellow  color.  Its  specific  gravity  is  0-911.  It  has  the  smell  and  taste  of  the 
juniper.  Water,  or  even  alcohol,  dissolves  very  little  of  it.  Gin  contains  a  very  minnte 
quantity  of  this  oil.  Like  oil  of  turpentine,  it  imparts  to  the  urine  of  persons  who  swallow 
it,  the  smell  of  violets.  Oil  of  juniper  is  frequently  sophisticated  with  oil  of  turpentine 
introduced  into  the  still  with  the  berries ;  a  fraud  easily  detected  by  the  diminished  den- 
=8ity  of  the  mixture. 

The  oil  of  lavender  is  extracted  from  the  flowering  spike  of  the  lavandula  spica.  It  is 
yellow,  very  fluid,  has  a  strong  odor  of  the  lavender,  and  a  burning  taste.  The 
specific  gravity  of  the  oil  found  in  commerce  is  0-898  at  the  temperature  of  72°  F.,  and 
of  0-877  when  it  has  been  rectified.  It  is  soluble  in  all  proportions  in  alcohol  of  0-830, 
but  alcohol  of  0-887  dissolves  only  42  per  cent,  of  its  weight.  The  fresh  oil  detonates 
slightly  when  mixed  with  iodine,  with  the  production  of  a  yellow  cloud.  There  occurs 
in  commerce  a  kind  of  oil  of  lavender  known  under  the  name  o<  oil  of  a«;nc  or  oil  of  spike, 
extracted  by  distillation  from  a  wild  variety  of  the  lavandula  spica,  which  has  large 
leaves,  and  is  therefore  called  latifolia.  This  oil  is  manufactured  in  the  south  of  Europe. 
Its  odor  is  less  characteristic  than  that  of  the  lavender,  resembling  somewhat  that  of 
oil  of  turpentine,  with  which  it  is  indeed  often  adulterated.  It  is  also  so  cheap  as 
to  be  sometimes  used  instead  of  the  latter  oil.  Oil  of  lavender  deposites,  when  partially 
'  exposed  to  the  air,  a  concrete  oil,  which  resembles  camphor,  to  the  amount  of  one  fourth 
of  its  weight. 

Oil  of  lemons  is  extracted  by  pressure  from  the  yellow  peel  of  the  fruit  of  the  lemon,  or 
ntrus  medica.     In  this  state  it  is  a  yellowish  fluid,  having  a  specific  gravity  of  0*8517  ; 
but  when  distilled  along  with  water  till  three  fifths  of  the  oil   have  come  over,  it  is  ob 
tained  in  a  colorless  state,  and  of  a  specific  gravity  of  0-847  at  72°  F.     This  oil  does  aol 
become  concrete  till  cooled  to  4°  below  0^  F. 

The  oil  of  lemons  has  a  very  agreeable  smell  of  the  fruit,  which  is  injured  by  distilla- 
tion. It  is  soluble  in  all  proportions  in  anhydrous  alcohol,  but  only  14  parts  dissolve  in 
100  of  spirits  of  wine  of  specific  gravity  0-837.  This  oil,  especially  when  distilled,  forms 
with  muriatic  acid  similar  camphorated  compounds  with  oil  of  turpentine,  absorbing  no 
less  than  280  volumes  of  the  acid  gas. 

Oil  of  lemons  kept  long,  in  ill-corked  bottles,  generates  a  quantity  of  stearessence, 
which  when  dissolved  in  alcohol,  precipitated  by  w4ter,  and  evaporated,  affords  brilliant, 
colorless,  transparent  needles.     Some  acetic  acid  is  also  generated  in  the  old  oil.     Accord 
ing  to  Brandes,  the  specific  gravity  of  oil  of  lemons  is  0-8786. 

The  oil  of  mace  lets  fall,  after  a  certain  time,  a  concrete  oil  under  the  form  of  a  crys- 
talline crust,  called  by  John  myristicine. 

The  oil  of  nutmegs  is  extracted  chiefly  from  mace,  which  is  the  inner  epidermis  of 
these  nuts.  It  is  colorless,  or  yellowish,  a  little  viscid  with  a  strong  aromatic  odor 
of  nutmegs,  an  acrid  taste,  and  a  specific  gravity  of  0-948.  Il  consists  of  two  oils,  which 
may  be  easily  separated  from  each  other  by  agitation  with  water;  for  one  of  them,  which 
is  more  volatile  and  aromatic,  comes  to  the  surface,  while  the  other,  which  is  denser, 
white,  and  of  a  buttery  consistence,  falls  to  the  bottom.  The  latter  liquefies  by  the  heat 
of  the  hand. 

The  oil  of  orange  flowers,  called  neroli,  is  extracted  from  the  fresh  flowers  of  the  ctYnw 
aurarUium.  When  recently  prepared  it  is  yellow ;  but  when  exposed  for  two  hours  to 
the  rays  of  the  sun,  or  for  a  longer  time  to  diffuse  daylight,  it  becomes  of  a  vellowish- 
red.  It  IS  very  fluid,  lighter  than  water,  and  has  a  most  agreeable  smell.  The  aqueous 
solution  known  under  the  name  of  orange-flower  water,  is  used  as  a  perfume.  It  is 
obtained  either  by  dissolving  the  oil  in  water,  or  by  distilling  with  water  the  leaves  cither 
fresh  or  salted  ;  the  first  being  the  stronger,  but  the  last  being  the  more  fragrant  prepar- 
ation. Orange-flower  water  obtained  by  distillation,  contains  besides  the  oil,  a  principle 
twhich  comes  over  with  it,  of  a  nature  hitherto  unknown ;  it  possesses  the  property  of  im- 
parting to  water  the  faculty  of  becoming  red  with  a  few  drops  of  sulphuric  acid.  The 
water  formed  from  the  oil  alone,  is  destitute  of  this  property.  The  intensity  of  the  rose- 
color  IS  a  test  m  some  measure  of  the  richness  of  the  water  in  oil. 

The  oil  of  parsley  is  extracted  from  the  apium  petroselinum.    It  is  of  a  pale  yellow 


296 


OILS,  VOLATir.E  OR  ESSENTIAL. 


OILS,  VOLATILE  OR  ESSENTIAL. 


S07 


•  ?i 


\i\ 


color,  having  the  smell  of  the  plant,  and  consists  of  two  oils  separable  by  agitation  in 
water.  Its  liquid  part  floats  upon  the  surface  in  a  very  fluid  form ;  its  stearessence, 
which  falls  to  the  bottom,  is  butyraceous  and  crystallizes  at  a  low  temperature.  This 
concrete  oil  melts  at  86°  F. 

The  oil  of  pepper  is  extracted  from  the  piper  nigrum.  In  the  recent  stale  it  is  limpid 
and  colorless,  but  by  keeping  it  becomes  yellow.  It  swims  upon  the  surface  of  water. 
In  odor  it  resembles  pepper,  but  is  devoid  of  its  hot  taste. 

The  oil  of  peppermint  is  extracted  from  the  meniha  piperita.  It  is  yellowish,  and  endued 
with  a  very  acrid  burning  taste.  Its  specific  gravity  is  0-920.  At  6°  or  7°  below  0°  F., 
it  deposites  small  capillary  cr\'stals.  After  long  keeping  it  aflbrds  a  stearessence  resem- 
bling camphor,  provided  the  oil  had  been  obtained  from  the  dry  plant  gathered  in  flower, 
but  not  from  distillation  of  the  fresh  plant.  When  artificially  cooled,  it  yields  6  per  cent, 
of  stearessence,  which  crystallizes  in  prisms  with  three  sides,  has  an  acrid,  somewhat  rank 
taste,  is  soluble  in  ether  and  alcohol,  and  is  thrown  down  from  the  latter  solution  by  water 
in  the  form  of  a  white  powder.  Peppermint  water  is  characterized  by  the  sensation  of 
coolness  which  it  diffuses  in  the  mouth. 

The  oil  of  pimento  is  extracted  from  the  envelopes  of  the  fruits  of  the  myrius  pimenta, 
which  afford  8  per  cent,  of  it.  It  is  yellowish,  almost  colorless,  of  a  smell  analogous  to 
that  of  cloves,  an  acrid  burning  taste,  and  a  specific  gravity  greater  than  water.  Nitric 
acid  makes  it  first  red,  and  after  the  effervescence,  of  a  rusty  brown  hue.  It  combines 
with  the  salifiable  bases,  like  oil  of  cloves. 

The  oil  of  rhodium  is  extracted  from  the  wood  of  the  convolvolus  scoparius.  It  is  very 
fluid,  and  has  a  yellow  color,  which  in  time  becomes  red.  It  has  somewhat  of  the  rose 
odor,  and  is  used  to  adulterate  the  genuine  otto.  Its  taste  is  bitter  and  aromatic,  which 
it  imparts  to  the  otto  as  well  as  its  fluidity. 

The  oil  of  roses,  called  also  the  attar  or  otto,  is  extracted  by  distillation  from  the  petals 
of  the  rosa  centifoUa  and  sempervirens.  Our  native  roses  furnish  such  small  quantities 
of  the  oil,  that  they  are  not  worth  distilling  for  the  purpose.  The  best  way  of  operating 
is  to  return  the  distilled  water  repeatedly  upon  fresh  petals,  and  eventually  to  cool  the 
saturated  water  with  ice ;  whereby  a  little  butyraceous  oil  is  deposited.  But  the  oil 
thus  obtained  has  not  a  very  agreeable  odor,  being  injured  by  the  action  of  the  air  in 
»he  r-peated  distillations.  In  the  East  Indies,  the  altar  is  obtained  by  stratifying  rose 
leaves  in  earthen  pans  in  alternate  layers,  with  the  oleiferous  seeds  of  a  species  of  digi- 
talis, called  gengeliy  for  several  days,  in  a  cool  situation.  The  fat  oil  of  the  seed  absorbs 
the  essential  oil  of  the  rose.  By  repeating  this  process  with  fresh  leaves  and  the  same 
seed,  this  becomes  eventually  swollen,  and  being  then  expressed  furnishes  the  oil.  The 
turbid  liquid  thus  obtained  is  left  at  rest,  in  well-closed  vessels,  where  it  gets  clarified. 
The  layer  of  oil  that  floats  on  the  top  is  then  drawn  off"  by  a  capillary  cotton  wick,  and 
subjected  to  distillation  along  with  water,  whereby  the  volatile  otto  is  separated  from  the 
fat  seed-oil. 

The  oil  of  roses  is  colorless,  and  possesses  the  smell  of  roses,  which  is  not  however 
agreeable,  unless  when  diff'used,  for  in  its  concentrated  state  it  is  far  from  pleasant  to  the 
nostrils,  and  is  apt  to  occasion  headaches.  Its  taste  is  bland  and  sweetish.  It  is  lighter 
than  water,  and  at  the  temperature  of  92^,  its  specific  gravity  compared  to  that  of  water 
at  60**  is  0-832.  At  lower  temperatures  it  becomes  concrete  and  butyraceous ;  and  after- 
wards fuses  at  90°.  It  is  but  slightly  soluble  in  alcohol ;  1000  parts  of  this  liquid  at  0-806 
dissolving  only  7|  parts  at  58°  F.  This  oil  consists  of  two  parts,  the  stearessence  and 
oleiessence ;  the  latter  being  the  more  volatile  odoriferous  po>!ion. 

The  oil  of  rosemary  is  extracted  from  the  rosmarinus  officialis.  It  is  as  \im\  d  as  water, 
has  the  smell  of  the  plant,  and  in  other  respects  resembles  oil  of  turpentine.  The  oil 
found  in  commerce  has  a  specific  gravity  of  0-911,  which  becomes  0-8886  by  rectification. 
It  boils  at  320°  F.  (occasionally  at  329°).  It  is  soluble  in  all  portions  in  alcohol  of  0830. 
When  kept  in  imperfectly  closed  vessels,  it  deposites  a  stearessence  vo  the  amount  of  one 
tenth  of  its  weight,  resembling  camphor.  It  is  sometimes  adulterated  with  oil  of  turpen- 
tine, a  fraud  easily  detected  by  adding  anhydrous  alcohol,  which  dissolves  only  the  oil  of 
rosemary. 

The  oil  of  saffron  is  extracted  from  the  stigmata  of  the  crocus  sativus.  It  is  yellow, 
very  fluid,  falls  to  the  bottom  of  water,  diffuses  the  penetrating  odor  of  the  plant,  and  has 
an  acrid  and  bitter  taste.     It  is  narcotic. 

The  oil  of  sassafras  is  extracted  from  the  woody  root  of  the  laurus  sassafras.  It  is 
colorless,  but  at  the  end  of  a  certain  time  it  becomes  yellow  or  red.  It  has  a  peculiar, 
sweetish,  pretty  agreeable,  but  somewhat  burning  taste.  Its  specific  gravity  is  1-094. 
According  to  Bonastre,  this  oil  separates  by  agitation  with  water  into  an  oil  lighter  and 


an  oil  heavier  than  this  fluid.     When  long  kept,  it  deposites  a  stearessence  in  transparent 
and  colorless  crystals,  which  have  the  smell  and  taste  of  the  liquid  oil. 

The  oil  of  savine  is  extracted  from  the  leaves  of  the  juniperus  sabina.  It  is  limpid, 
and  has  the  odor  and  taste  of  the  plant,  which  is  one  more  productive  of  volatile  oil  than 
any  other. 

The  oil  of  tansy  has  a  specific  gravity  of  0-946,  the  penetrating  odor  of  the  tanacetum 
vulgare,  with  an  acrid  and  bitter  taste. 

Oil  of  turpentine,  commonly  called  essence  of  turpentine.  It  is  extracted  from  several 
species  of  turpentine,  a  semi-liquid  resinous  substance  which  exudes  from  certain  trees 
of  the  pine  tribe,  and  is  obtained  by  distilling  the  resin  along  with  water.  This  oil  is 
the  cheapest  of  all  the  volatile  species,  and,  as  commonly  sold,  contains  a  little  resin, 
from  which  it  may  be  freed  by  re-distillation  with  water.  It  is  colorless,  limpid,  very 
fluid,  and  has  a  very  peculiar  smell.  Its  specific  gravity  at  60°  is  0-872 ;  that  of  the 
spirit  on  sale  in  the  shops  is  0-876.  This  oil  always  reddens  litmus  paper,  because  it  con- 
tains a  little  succinic  acid. 

100  parts  of  spirits  of  wine,  of  specific  gravity  0-84,  dissolve  only  13|  of  oil  of  turpen- 
tine at  72°  F.      When  agitated  with  alcohol  at  0-830  the  oil  retains  afterwards  one  fifth 
of  its  bulk  of  the  spirit ;  hence  this  proposed  method  for  purifying  oil  of  turpentine  is 
defective.     The  oil,  if  left  during  four  months  in  contact  with  air,  is  capable  of  absorbing 
20  times  its  bulk  of  oxygen  gas.      One  volume  of  rectified  oil  of  turpentine  absorbs  at 
the  temperature  of  72°,  and  under  the  common  atmospheric  pressure,  163  times  its  vol- 
ume of  muriatic  acid  gas,  provided  the  vessel  be  kept  cool  with  ice.     This  mixture  being 
allowed  to  repose  for  24  hours,  produces  out  of  the  oil  from  26  to  47  per  cent,  of  a  white 
crystalline  substance,  which  subsides  to  the  bottom  of  a  brown,  smoking,  translucent 
liquor.     Others  say  that   100  parts  of  oil  of  turpentine  yield  110  of  this  crystalline 
matter,  which  was  called  by  Kind,  its  discoverer,  artificial  camphor,  from  its  resemblance 
in  smell  and  appearance  to  this  substance.      Both  the  solid  and  the  liquid  are  combina- 
tions of  muriatic  acid  and  oil  of  turpentine;  indicating  the  existence  of  a  stearine  and  an 
oleine  in  the  latter  substance.      The  liquid  compound  is  lighter  than  water,  and  is  not 
decomposed  by  it,  nor  does  it  furnish  any  more  solid  matter  when  more  muriatic  gas  is 
passed  through  it.      The  solid  compound,  after  being  washed  first  with  water  containing 
a  little  carbonate  of  soda,  then  with  pure  water,  and  finally  purified  by  sublimation  with 
some  chalk,  lime,  ashes,  or  charcoal,  appears  as  a  white,  translucent,  crj'slalline  bodv,  in 
the  form  of  flexible,  tenacious  needles.      It  swims  upon  the  surface  of  water,  diff'uses  a 
faint  smell  of  camphor,  commonly  mixed  with  that  of  oil  of  turpentine,  and  has  rather 
an  aromatic  than  a  camphorated  taste.      It  does  not  redden  litmus  paper.      Water 
dissolves  a  very  minute  quantity;  but  cold  alcohol  of  0-806  dissolves  fully  one  thiid  ol 
its  weight,  and  Lot  much  more,  depositing,  as  it  cools,  this  excess  in  the  form  of  crystals. 
The  solution  is  not  precipitated  by  nitrate  of  silver,  which  shows  that  the  nature  of  the 
muriatic  acid  is  perfectly  masked  by  the  combination.      It  is  composed,  in  100  parts,  of 
76-4  cartwn,  9-6  hydrogen,  and  14  muriatic  acid.     The  muriatic  acid,  or  chlorine,  may  be 
separated  by  distilling  an  alcoholic  solution  of  the  artificial  camphor  12  or  14  times  in 
succession  M'ilh  slaked  lime. 

Oil  of  turpentine  is  best  preserved  in  casks  enclosed  within  others,  with  water  between 
the  two.     Its  principal  use  is  for  making  varnishes,  and  as  a  remedy  for  the  tape-worm. 

The  oil  of  thyme  is  extracted  from  the  thymus  serpyUum.  It  is  reddish  yellow,  has  an 
agreeable  smell,  and,  after  being  long  kept,  it  lets  fall  a  crystalline  stearessence.  It  is 
used  merely  as  a  perfume. 

The  oil  of  wormwood  is  extracted  from  the  artemisia  absinthium.  It  is  yellow,  or 
sometimes  green,  and  possesses  the  odor  of  the  plant.  Its  taste  resembles  that  of 
wormwood,  but  without  its  bitterness.  Its  specific  gravity  is  0-9703,  according  to  Brisson, 
and  0-9725,  according  to  Brandes.  It  detonates  with  iodine  when  it  is  fresh.  Treated 
with  nitric  acid  of  1-25  specific  gravity,  it  becomes  first  blue,  and  after  some  lime 
brown. 


The  numerous  uses  of  unctuous  oils  give  importance  to  their  preparation,  as  articles 
of  food,  or  for  burning  m  lamps,  and  for  the  manufacture  of  soaps,  Ac.  The  seeds 
most  productive  of  oil  are  those  of  colza  (a  species  of  cabbage,  brassica  arve7i^s\ 
rape,  mustard,  sesamum,  poppy,  linseed,  hemp,  and  beech  mast.  Nuts  afford  an  oS 
that  18  much  esteemed  for  certain  purposes,  and  may  be  easily  obtained  by  pressure. 
The  following  Table  indicates  the  quantities  of  oil  which  can  le  extracted  from  diff-er- 
ent  fruits,  and  some  other  substances :  — 


Vol.  IL 


2Q 


298 


OILS,  iTOLATILS  OR  ESSENTIAL. 


100  Parti  of  each 


Walnuts  -         -         - 

Castor-oil  seeds 
Hazel-nuts      ... 
Garden  cress  seed  - 
Sweet  almonds 
Bitter  almonds 
Poppy-seeds    -        -        . 
Oily  radish  seed 
Sesamum  (jugoline) 
Lime-tree  seeds 
Cabbage-seed 
White  mustard      r- 
Rape,  colewort,  and  Swe- 
dish turnip  seeds  - 
Plum  kernels  .        . 
Colza-seed 

Rape-seed      -        .        - 
Euphorbium  (spurge  seed) 


Oil  per  Cent. 


40  to  70 

62 

60 
66  to  58 
40  to  54 
28  to  46 
56  to  63 

50 

60 

48 
30  to  39 
36  to  38 

33-5 

33-3 

36  to  40 

30  to  36 

30 


100  Parts  of  each. 


acanihe,  or 


Wild  mustard  seed  - 

Camelina-jieed 

Weld -seed 

Gourd-seed     « 

Lemon-seed    - 

Onocardium 
bear's  foot 

Hemp-seed 

Linseed  -        -        -        . 

Black  mustard  seed 

Beechmast      -        .        . 

Sunflower-seeds 

Stramonium,     or     thorn- 
apple-seeds 

Grape-stones  - 

Horse  chestnuts 

St.  Julian  plum 


Oil  per  Cent. 


30 
28 
29  to  36 
25 
25 

25 

14  to  25 
11  to  22 

15 

15  to  17 
15 

15 
14  to  22 
1-2  to  8 

18 


To  obtain  the  above  proportions  of  oil,  the  fruits  must  be  all  of  good  quality,  deprived 
of  their  pods,  coats,  or  involucra,  and  of  all  the  parts  destitute  of  oil,  which  also  must  be 
extracted  in  the  best  manner. 

The  following  table  is  given  by  M.  Dumas,  as  exhibiting  the  practical  results  of  the 
French  seed  oil  manufacturers : — 


Weight  per  Hectolitre. 

Produce  in  Litres. 

Summer  colza 

Winter  colza       -            ,            - 

Rape-seed 

Camelina-seed     ... 

Poppy-seed          ... 

Madia  Sativa     -            -            - 

Beechmast           ... 

Hemp-seed          ... 

Linseed  .... 

Stripped  walnuts  ... 

Sweet  almonds     - 

Olives     -            . 

54  to  65  kilogs. 
56  to  70    — 
65  to  68    — 

63  to  60    — 

64  to  62    — 
40  to  60    — 
42  to  50    — 
42  to  50    — 
By  sample,  67. 

From  100  kilogs. 

—  100    — 

—  100    — 

21  to  25 
25  to  28 
23  to  26 
20  to  24 

22  to  25 
12  to  15 
12  to  15 
12  to  15 
10  to  12 
46  to  50 
44  to  48 
10  to  12 

Colza,  rape-seed,  and  cameline  oils  are  employed  for  lamps;  poppy,  madia  sativa^  are 
employed,  when  recent,  as  articles  of  food— or  for  soaps  and  paintings;  hemp-seed  and 
linseed  for  painting,  soft  soaps,  and  for  printers'  ink ;  walnut  oil,  for  food,  painting,  and 
lamps ;  olive  oil,  for  food,  soaps,  lamps. 

In  extracting  oil  from  seeds,  two  processes  are  required — 1st,  trituration ;  2d,  expres" 
tion  ;  and  the  steps  are  as  follows  : — 

1.  Bruising  under  revolving  heavy-edge  millstones,  in  a  circular  bed,  or  trough  of  iron, 
bedd<;d  on  granite. 

2.  Heating  of  the  bruised  seeds,  by  the  heat  either  of  a  naked  fire  or  of  steam. 

3.  First  pressure  or  crushing  of  the  seeds,  either  by  wedges,  screw,  or  hydraulic  preaeea. 

4.  Second  crushing  of  the  seed  cakes  of  the  first  pressure. 

5.  Heating  the  bruised  cakes ;  and  6.  A  final  crushing. 

The  seeds  are  now  very  generally  crushed,  first  of  all  between  two  iron  cylinders 
revolving  in  opposite  directions,  and  fed  in  from  a  hopper  above  them ;  after  which  they 
yield  more  completely  to  the  triturating  action  of  the  edge  stones,  which  are  usually 
hooped  round  with  a  massive  iron  ring.  A  pair  of  edge  millstones  of  about  7  or  7| 
feet  in  diameter,  and  25  or  26  inches  thick,  weighing  ft-om  7  to  8  tons,  can  crush,  in 
12  hours,  from  2J  to  3  tons  of  seeds.  The  edge-millstones  serve  not  merely  to  grind 
the  seeds  at  first,  but  to  triturate  the  cakes  after  they  have  been  crushed  in  the  press. 
Old  dry  seeds  sometimes  require  to  be  sprinkled  with  a  little  water  to  make  the  oil 
come  more  freely  away ;  but  this  practice  requires  great  care. 

The  apparatus  for  heating  the  bruised  seeas  consists  usually  of  cast  iron  or  copper 


OIL  MANUFACTURE. 


S99 


pans,  with  stirrers  moved  by  machinery.  Figa.  1016  1017  1018  1019  represent  the  heaters 
by  naked  fire,  as  mounted  in  Messrs.  Maudsley  and  Field's  excellent  seed  crushing 
mills,  on  the  wedge  or  Dutch  plan. 

J^tg. lOieis  an  elevation,  or  side  view  of  the  fireplace  of  a  naked  heater;  /g.l017 
is  a  plan,  in  the  line  UU  of  Jig.  1016  Fig.  1018  is  an  elevation  and  section  parallel  to 
the  line  VV  of  Jig.  1017  Fig.  1019  is  a  plan  of  the  furnace,  taken  above  the  gratp 
of  the  fireplace. 


-^^ 


"  '■  " 


^ 


I 


1019 


A,  fireplace  shut  at  top  by  the  cast-iron  plate  B ;  called  the  fireplate. 

C,  iron  ring-pan,  resting  on  the  plate  B,  for  holding  the  seeds  ,•  which  is  kept  ia  its 
,  >lace  by  the  pins  or  bolts  a.  o  i  4.         « 

D,  funnels,  britchen,  into  which  by  pulUng  the  ring.«ase  c,  by  the  handles  b,  b,  the 
se^  are  made  to  fall,  from  which  they  pass  into  bags  suspended  to  the  hooks  c. 

:^?'  1018  the  stirrer  which  prevents  the  seeds  from  being  burned  by  contmued 
contact  with  the  hot  plate.  It  is  attached  by  a  turning-joint  to  the  collar  F,  wliich 
turns  with  the  shaft  G,  and  slides  up  and  down  upon  it.  H,  a  bevel  wheel,  in  ^ear 
with  the  bevel  wheel  I,  and  giving  motion  to  the  shaft  G. 

K,  a  lever  for  lifting  up  the  agitator  or  stirrer  E.    «,  a  catch  for  holding  up  the 
lever  K,  when  it  has  been  raised  to  a  proper  height. 


300  OILS,  ADULTERATION  OF 

Fig.  1020  front  elevation  of   the  wedge  seed-crushing  machine,  or  wedgc-presa. 
Fig.  1021  section,  in  the  line  XX,  of  Jig.  1022. 

1021  y  ^020  y 


Fig.  1022  horizontal  section,  in  the  line  YY,  of  ^g.  1021. 


if'iit 


1022 


A,  A,  Upright  guides,  or  frame-work  of  wood. 

B,  B,  Side  guide-rails. 

D,  Driving  stamper  of  wood  which  presses  out  the  oil ;  C,  spring  stamper,  ir  re- 
Diving  wedge  to  permit  the  bag  to  be  taken  out  when  sufficiently  pressed.  E  is  the 
lifting  shaft"  having  rollers,  6,  6,  6,  6,  fig- 1021  which  lift  the  stampers  by  the  cams, 
fl,  o.  Jig.  1021.  F,  is  the  shaft  from  the  power-engine,  on  which  the  lifters  are  fixed. 

G,  is  the  cast  iron  press-box,  in  which  the  bags  of  seed  are  placed  for  pressure,  later- 
ally by  the  force  of  the  wedge. 

0,  Jig*.  1019  and  1023  the  spring,  or  relieving  wedge. 

«,  lighter  rail ;  d,  lifting-rope  to  ditto. 

/»  />  /f  ff  flooring  overhead. 


OILS,  ADULTERATION  OF. 


301 


1023 


g,  Jigs.  1019and  1023  ;the  back  iron,  or  end-plate  minutely  perforated. 
hy  the  horse-hair  bags  (called  hairs),  containing  the  flannel  bag,  charged  with  seed  j 
if  the  dam-block ;  m,  the  spring  wedge. 

ftg.  1022  A,  upright  guides;  C,  and  D,  spring  and  driving  stampers;  E,  lifting 
roller;   F,  lifting  shaft;  a,  a,  cams  of  stampers. 

Fig.  1023  a  view  of  one  set  of  the  wedge-boxes,  or  presses ;  supposing  the  front  of 
them  to  be  removed. 

i^ig.  1023;  o,  driving  wedge;  g,  back 
iron ;  A,  hairs ;  i,  dam-block ;  Ar,  speer- 
ing  or  oblique  block,  between  the  two 
stampers ;  /,  ditto ;  n,  ditto ;  tw,  spring 
wedge. 

When  in  the  course  of  a  few  minutes 
the  bruised  seeds  are  sufficiently  heated 
in  the  pans,  the  double  door  FF  is  with- 
drawn, and  they  are  received  in  the  bags, 
below  the  aperture  G.  These  bags  are 
made  of  strong  twilled  woollen  cloth, 
woven  on  purpose.  They  are  then 
wrapped  in  a  hair-cloth,  lined  with 
leather. 

The  first  pressure  requires  only  a  dozen  blows  of  the  stamper,  after  which  the  pouches 
are  left  alone  for  a  few  minutes  till  the  oil  has  had  time  to  flow  out ;  in  which  interval 
the  workmen  prepare  fresh  bags.  The  former  are  then  unlocked,  by  making  the  stamper 
fall  upon  the  loosening  wedge  or  key,  m. 

The  weight  of  the  stampers  is  usually  from  500  to  600  pounds ;  and  the  height  from 
which  they  fall  upon  the  wedges  is  from  16  to  21  inches. 

Such  a  mill  as  that  now  described,  can  produce  a  presstire  of  from  50  to  75  tons 
upon  each  cake  of  the  following  dimensions  :  8  inches  in  the  broader  base,  7  inches 
m  the  narrower,  18  inches  in  the  height ;  altogether  nearly  140  square  inches  in  surface, 
and  about  |  of  an  inch  thick. 

OILS,  ADULTERATION  OF.  M.  Heidenreich  has  found  in  the  application 
of  a  few  drops  of  sulphuric  acid  to  a  film  of  oil,  upon  a  glass  plate,  a  means  of  ascer- 
taining Its  purity.  The  glass  plate  should  be  laid  upon  a  sheet  of  white  paper,  and  a 
drop  of  the  acid  let  fall  on  the  middle  of  ten  drops  of  the  oil  to  be  tried. 

With  the  oil  of  rape-seed  and  turnip-seed,  a  greenish  blue  ring  is  gradually  formed  at 
a  certain  distance  from  the  acid,  and  some  yellowish  brown  bands  proceed  from  the 
centre. 

With  oil  of  black  mustard,  in  double  the  above  quantity,  also  a  bluish  green  color. 

With  whale  and  cod-oil,  a  peculiar  centrifugal  motion,  then  a  red  color,  increasing 
gradually  in  intensity ;  and  after  sometime,  it  becomes  violet  on  the  edges. 

With  oil  of  cameline,  a  red  color,  passing  into  bright  yellow. 

Olive-oil,  pale  yellow,  into  yellowish  green. 

Oil  of  poppies  and  sweet  almonds,  canary  yellow,  passing  into  an  opaque  yellow. 

Of  linseed,  a  brown  magma,  becoming  black. 

Of  tallow  or  oleine,  a  brown  color. 

In  testing  oils,  a  sample  of  the  oil  imagined  to  be  present  should  be  placed  alongside 
of  the  actual  oil,  and  both  be  compared  in  their  reactions  with  the  acid.  A  good  way 
of  approximating  to  the  knowledge  of  an  oil  is  by  heating  it,  when  its  peculiar  odor 
becomes  more  sensible. 

Specific  gravity  is  also  a  good  criterion.  The  following  table  is  given  by  M.  Hei- 
denreich : —  o  j 


L_5 


Oleine  oi  Tallow  Oil 
Oil  of  Turnip  Seed 
Rape  Oil     - 
Olive  Oil     - 
Purified  Whale  Oil 
Oil  of  Poppies 
Oil  of  Camelina  - 
Linseed  Oil- 
Castor  Oil  - 


Sp.  Gr. 

Gay-Lussac's  Alcoholm. 

. 

0-9003 

66 

- 

0-9128 

60-75 

- 

0-9136 

60-20 

• 

0-9176 

58-40 

- 

0-9231 

55-80 

- 

0-9243 

55-25 

- 

0-9252 

54-75 

0-9347 

50 

0-9611 

33-75 

M.  Laurot,  a  Parisian  chemist,  finds  that  colza  oil  (analogous  to  rapeseed  oil)  maf 
be  tested  for  sophistication  with  cheaper  vegetable  oils  by  the  increase  of  density 


302 


OILS,  TESTS  OF. 


OILS,  TESTS  OF. 


303 


5 
N 


I 


which  it  therefrom  acquires,  and  which  becomes  very  evident  when  the  several  oils 
are  heated  to  the  same  pitch.  The  instrument,  which  he  calls  an  oleometer,  is  merely 
a  hydrometer,  with  a  very  slender  stem.  He  plunges  it  into  a  tin  cylinder,  filled  with 
the  oil,  and  sets  this  cylinder  in  another  containing  boiling  water.  His  oleometer  is 
so  graduated  as  to  sink  to  zero  in  pure  colza  oil  so  heated ;  and  he  finds  that  it  stops 
at  210*  in  linseed  oil,  at  124^  in  poppy-seed  oil,  at  83'^  in  fish  oil,  and  at  136'^  in  hemp- 
seed  oil — all  of  the  same  temperature.  By  the  increase  of  density,  therefore,  or  the 
ascent  of  the  stem  of  the  hydrometer  in  any  kind  of  colza  oil,  he  can  infer  its  degree 
of  adulteration. 

The  presence  of  a  fish  oil  in  a  vegetable  oil  is  readily  ascertained  by  agitation  with  a 
little  chlorine  gas,  which  blackens  the  fish  oil,  but  has  little  or  no  effect  upon  the 
vegetable  oil. 

I  find  that  lard  oil,  and  also  hogs'  lard,  are  not  at  all  darkened  by  chlorine. 
A  specific  gravity,  bottle  or  globe,  having  a  capillary  tube-stopper,  would  make  an 
excellent  oleometer,  on  the  above  principle.  The  vessel  should  be  filled  with  the  oil, 
and  exposed  to  the  heat  of  boiling  water,  or  steam  at  212^,  till  it  acquires  that  tem- 
perature, and  then  weighed.  The  vessel  with  the  pure  colza  oil  will  weigh  several 
grains  less  than  with  the  other  oils  similarly  treated.  Such  an  instrument  would  serve 
to  detect  the  smallest  adulterations  of  sperm  oil.  Its  specific  gravity  at  60^  when 
pure  is  only  0-875 ;  that  of  southern  whale  oil  is  0-922,  or  0-925 ;  and  hence  their 
mixture  will  give  a  specific  gravity  intermediate,  according  to  the  proportion  in  the 
mixture.  Thus  I  have  been  enabled  to  detect  sperm  oil  in  pretended  lard  oil,  in  my 
examination  of  oils  for  the  customs. 

OILS  ESSENTIAL,  Tests  of  Furitj/.  \.  01.  Amygdalarum  amar.  {Bitter  Almonds). 
This  oil  possesses,  besides  its  specific  gravity  and  peculiar  smell,  so  many  striking  chemi- 
cal characteristics,  that  any  adulteration  of  it  must  be  easily  detected.  To  these  cha- 
racteristics belong  its  great  ^eox  solubility  in  sulphuric  acid,  with  a  reddish  brown  colora- 
tion and  wittumt  any  visible  decomposition  ;  the  very  slow  action  which  nitric  acid  has 
upon  it,  without  either  of  the  two  substances  undergoing  any  change  in  its  physical  pro- 
perties ;  the  only  partial  slow  solution  of  iodine  without  further  reaction ;  the  indiflference 
to  chromate  of  potash  ;  the  elimination  of  crystals  from  its  solution  in  an  alcoholic  solvr 
tion  of  caustic  potash  ;  the  peculiar  inspissation  by  caustic  ammonia  and  muriatic  acid, 
and  the  elimination  of  crystals  from  the  alcoholic  solution  of  these  new  compounds, 
and  lastly,  the  decidedly  acid  reaction  ;  in  short,  almost  by  every  reagent  some  peculiarity 
of  this  oil  is  displayed,  by  which  its  purity  can  be  perfectly  and  easily  established. 

2.  01.  Caryophyllorum  {Cloves).  The  properties  which  this  oil  possesses  afford  great 
opportunity  of  discovering  its  purity.  Firstly,  its  relation  to  the  alcoholic  solution  of 
caustk  potash,  with  which  it  congeals  entirely  mto  a  crystalline  mass,  totally  losing  at  the 
same  time  the  clove  odmir.  Any  foreign  substance  present  would  be  excluded  from  this 
compound,  or  would  interrupt  and  weaken  it  Similar  to  this,  and  equally  marked,  is 
the  butyraeeous  coagulum,  which  is  obtained  by  shaking  the  oil  with  a  solution  of  caus- 
tic ammonia,  and  which,  after  fusion,  crystallizes.  The  spontaneous  ready  decomposition 
by  nitric  acid,  and  simultaneous  formation  of  a  reddish  brown  solid  mass,  as  also  the 
dark  blue  coloration  of  the  oil  by  a  small  quantity  of  sulphuric  acid,  whilst  a  greater 
portion  of  the  latter  changes  the  oil  into  a  blood  red  solid  mass,  are  equally  striking 
tests.  To  these  we  may  add  the  perfect  decomposition  of  the  oil  into  brown  flakes  by 
ehrmnate  of  potash,  accompanied  by  the  loss  of  the  yellow  colour  of  the  solution  of  this 
salt ;  the  solubility  of  iodine,  which  forms  with  it  a  liquid  extract,  with  but  a  small 
increase  of  temperature,  and  also  the  perfect  and  easy  solubility  of  sautaline  in  it. 

3.  01.  Cinnamomi  {Cinnamon).  With  this  oil  the  question  is  not  merely  to  detect  an 
adulteration  with  other  oils,  but  also  to  distinguish  the  two  sorts  of  this  oil  from  one 
another,  viz.,  the  Ceylon  oil  {oleum,  cinnamomi  verum)  and  the  Chinese  oil  {oleum  cassics) 
which  differ  very  much  in  price.  In  both  cases  it  is  difllicult  to  obtain  accurate  tests  of 
the  properties  of  these  oils,  as  they  are  almost  exclusively  obtained  by  way  of  commerce, 
and  vary  considerably  in  their  qualities,  on  account  of  their  age  and  careless  method 
of  preparation.  The  chief  distinction  between  the  two  oils  is  the  odour :  the  Ceylon 
oil  is,  moreover,  more  liquid,  and  of  a  less  specific  weight  than  the  Chinese,  and  may 
be  exposed  to  a  greater  degree  of  cold  than  the  latter  without  becoming  turbid.  The 
most  distinguishing  characteristic  of  the  cinnamon  oils  is,  perhaps,  their  relation  to  the 
alcoholic  solution  of  caustic  potash :  both  dissolve  in  it  readily  and  clear,  with  a  red- 
dish yellowish  brown  colour;  after  some  time,  however,  the  solution  becomes  very 
turbid,  and  a  rather  heavy  undissolved  oil  precipitates,  whilst  the  solution  gradually 
becomes  clear  again. 

Another  peculiar  character  is,  where  the  oil  is  being  decomposed  by  nitric  acid  a 
smell  of  bitter  almond  oil  is  perceptible.  Both  oils  are  at  the  same  time  converted 
into  a  brown  balsam ;  in  the  Ceylon  oil  a  brisk  decomposition  occurs  sooner,  and  at  a 
slighter  heat. 


Iodine  dissolves  rapidly  in  the  Ceylon  oil  with  a  considerable  increase  of  heat,  and  a 
slight  expulsive  movement,  a  tough  extract-like  substance  remaining  behind.  With 
the  Chinese  oil  the  reaction  is  slow,  the  development  of  heat  but  very  slight,  quiet,  and 
the  residue  a  soft  or  liquid  substance. 

Chromate  of  potash  decomposes  partially  the  Ceylon  oil  into  brown  flakes,  which  are 
suspended  in  the  solution.  This  is  deprived  of  its  yellow  colour,  whilst  the  undecom- 
posed  portion  of  the  oil  assumes  a  yellowish  light  red  colour,  and  becomes  thick.  The 
solution  treated  with  Chinese  oil  does  not  entirely  lose  its  yell<m  colour,  contains  no 
flakes,  and  the  oil,  turbid,  emulsive-like,  does  not  become  clear  again. 

Sulphuric  a^id  also  furnishes  a  good  test  for  these  oils ;  the  Ceylon  oil  forms  with  it  a 
solid  hard  mass,  changing  from  a  brownish-green  into  deep  black ;  in  the  Chinese  oil, 
this  substance  is  softer,  and  deep  olive  green.  A  smaller  quantity  of  acid  colours  the  oils 
purple-red,  whilst  muriatic  acid  imparts  to  them  a  violet  colour. 

4.  01.  Sassafras  {Sassafras.)  This  oil  is  distinguished  from  most  other  oils  by  the 
clear  solution  produced  by  iodine  withotU  inspissation.  The  green  colour,  which  is  at 
first  produced  by  two  parts  of  oil  and  one  part  sulphuric  acid,  is  not  produced  by  any 
other  oil ;  by  heat,  this  colour  changes  to  blood-red  A  greater  quantity  of  oil  produces 
in  the  heated  acid  a  magnificent  amaranth  red  colour,  whilst  the  oil  itself  appears  only 
brownish  or  bluish  red.  With  nitric  acid  the  decomposition  takes  place  witltout  heat, 
and  reddish  brown  resin  is  formed,  which  on  being  heated  becomes  hard  and  brittle. 
The  great  specific  gravity  and  the  low  degree  of  solubility  in  alcohol  will  easily  lead 
to  the  detection  of  an  admixture  of  the  latter  which  would  counteract  these  properties. 

5.  01.  Anisi  Stellati  {Star  Anise.)  This  oil  participates  in  many  properties  of  those 
oils  of  the  umbelliferaj  which  contain  much  stearoptene.  Its  combination  with  iodine, 
which  takes  place  with  a  less  development  of  vapour  and  heat,  congeals  into  a  solid 
resinous  substance.  By  sulphuric  acid  this  oil  also  easily  becomes  inspissated,  is 
changed  into  a  solid  mass,  and  becomes  by  heat  dark  blood-red.  Nitric  acid,  however, 
Di-oduces  only  a  thick  fluid  balsam,  whilst  the  oil  becomes  yellow,  and  by  heat  reddish- 
orown.  The  difiiculty  with  which  the  oil  is  dissolved  in  five  or  six  parts  of  alcohol, 
and  in  the  alcoholic  solution  of  potash,  with  slight  coloration,  as  also  its  relation  to 
cold,  are  useful  tests. 

6.  01.  Anisi  vulgaris  {common  Anise).  The  constant  specific  gravity  of  the  ol.  anisi 
(from  0-97  to  0'99,  and  still  more  frequently  from  0*98  to  0*99),  as  well  as  its  disposition 
to  congeal  readily  at  below  a  medium  temperature,  are  good  tests  for  this  oil.  But  still 
more  so  is  its  quick  congelation  into  a  solid  hard  mass  with  iodine,  accompanied  with  a 
perceptible  iiicrease  of  heat,  and  the  development  of  yellowish-red  and  gray  vapours. 
Sulphuric  acid  heated  with  the  oil,  produces  a  beautiful  purple-red  colour,  and  quickly 
inspissates  and  hardens  it  The  other  reactions  are  similar  to  those  of  oil  of  star  anis«j^ 
and  will,  combined  with  those  here  mentioned,  sufficiently  characterize  this  oil. 

7.  01.  JiutcB  {Rue).  The  high  price  and  strong  smell  of  this  oil  lead  to  and  facilitate 
its  adulteration.  If  prepared  in  the  laboratory,  this  oil  is  distinguished  by  being  slowly 
dissolved  by  iodine,  unaccompanied  by  any  external  signs  of  reaction,  and  the  formation 
of  slightly  viscid  liquid;  by  this  means  adulterations  with  oils  of  eoniferae,  aurantiacese, 
and  most  labiata;  can  be  detected  in  it  Kitric  acid  acts  but  slowly  on  it,  and  changes 
it  into  a  greenish  yellow  thin  liquid  balsam ;  chromate  of  potash  produces  no  reaction. 
By  the  turbid  solution  in  alcohol,  by  the  reddish  brown  solution  in  liquor  potassae,  and 
by  the  similar  but  darker  coloration  which  the  oil  and  the  acid  assume  by  sulphuric 
acid,  the  cheaper  oils  of  the  labiatae  may  be  easily  detected  in  it  The  commercial 
compared  with  these  characteristics  appeared  to  be  only  an  adulterated  one. 

8.  01.  CajepuU  {Cajeput).  Omitting  the  tests  for  less  frequently  occurring 
adulterations  of  this  oil,  1  confine  myself  to  mentioning  only  those  tests  of  its  purity 
which  are  the  result  of  my  experiments,  chiefly  with  regard  to  the  rectified  oil,  which 
alone  ought  to  be  employed  for  medical  purposes. 

The  first  of  these  is  the  nature  of  the  residue,  resulting  from  the  reaction  of  iodine 
after  a  slightly  energetic  reciprocal  action,  during  which  the  temperature  was  but  little 
mcreased  and  the  development  of  yellowish-red  vapours  but  slight  (in  another  crude  oil 
no  such  development  took  place),  the  residue  becomes  immediately  inspissated  into  a 
loose  coagulum,  which  is  soon  changed  into  a  dry  greenish-brown  brittle  mass.  Ful- 
minating oils  are  therefore  easily  detected,  also  the  more  energetically  acting  oils  of  the 
labiata};  viz.,  ol.  lavendul.  spireae  origani.  But  also  the  less  violently  acting  oils  cf 
labiatse,  such  as  ol.  rorismarini,  which  serves  most  frequently  for  adulteration,  but 
which  are  distinguished  by  the  energetic  action  of  a  solution  of  iodine,  can  be  recog- 
nised by  the  degree  of  energy  with  which  this  reaction  takes  place;  all,  however, 
would  materially  alter  the  nature  of  the  residue  of  the  iodine  test  above  described. 
The  oL  rorismarini  manifests  under  certain  circumstances,  also,  some  coagulating  solid 
parts  in  its  residue,  but  which  always  has  the  consistency  of  a  soft  extract 

The  slight  changes  of  colour  which  are  produced  by  chromate  of  potash,  are  some- 


304 


OILS,  TESTS  OF. 


OILS,  TESTS  OF. 


305 


1 


what  more  marked  with  the  ol.  rorismarini,  but  the  equally  slight  colour  of  the 
eolution  in  liquor  potassse,  which  is  clear  in  the  cold  and  turbid  when  warm,  is  the 
same  in  the  oL  rorismarini.  The  latter  oil  could  not  be  detected  by  the  sulphuric  acid 
test ;  the  latter  assumes  a  deep  red  yellowish  colour,  and  the  oil  becomes  brownish ; 
by  this,  however,  many  other  adulterations  may  be  indicated.  The  weak  colorations 
of  the  ol.  cajeputi  by  nitric  acid^  which  imparts  only  a  reddish  and  brownish  colour, 
accompanied  by  a  violent  reaction  and  formation  of  a  liquid  balsam,  will  easily  dis- 
thiguish  it  from  some  other  oils,  but  not  from  oL  rorismarini.  Its  relation  to  iodine 
is,  therefore,  the  safest  test :  it  can  also  be  recognized  by  a  sensation  of  cold  which  it 
leaves  behind  in  the  mouth.  Its  specific  gravity  being  below  0'91  to  0*92,  will  show 
the  presence  of  lighter  oils  and  alcohol,  and  a  divided  rectification,  and  its  relation  to 
water  will  detect  the  adulteration  with  camphor. 

9.  01.  MenthcB  Piperitce  (Peppermint). — ^Any  adulteration  of  this  oil,  except  with  alco- 
hol or  other  mint  oils,  could  be  easily  detected  by  the  peculiar  smell  and  taste  of  this  oil. 
The  presence  of  alcohol  is  betrayed  by  the  specific  gravity,  which  is  seldom  under  0*90, 
and  which  must  be  considerably  lower  if  the  alcohol  be  stronger.  Of  the  other  mint 
oils  we  certainly  are  only  acquainted  with  that  of  M.  crispa  and  crispata  ;  we  may, 
however,  conclude  from  the  deviating  relation  of  the  ol.  menth.  piperit.  to  chrwnate  of 
potash  and  to  iodine,  that  the  other  sorts  diifer  from  it  chemically,  as  well  as  the  plants 
from  which  they  are  obtained  differ  from  one  another  in  smell. 

The  most  distinguishing  character,  which  the  peppermint  oil  shares  with  no  other  oil 
of  the  labiatce,  though  with  some  of  the  compositae,  is  its  relation  to  chromate  of  potash, 
which  commmiicates  to  it  a  deep  red  hrown.  colour,  and  inspissates  it  into  a  coagulum 
more  like  an  extract  than  a  resm,  and  by  motion  is  divided  into  a  flaky  form,  whilst 
the  solution  of  the  salt  soon  loses  the  whole  of  its  yellow  colour,  or  appears  yellowish- 
green. 

The  purple  red  colour  imparted  to  the  oil  by  the  fourth  part  of  its  volume  of  nitric 
acid,  is,  at  least  for  the  qualities  of  0'89  to  090,  very  characteristic.  The  other  oils, 
which  become  merely  brown,  show  at  least  a  tendency  to  red,  but  all,  upon  an 
addition  of  acid  at  a  higher  temperature,  change  to  a  reddish-brown,  and  into  a  liquid 
balsam. 

Mr.  B.  Sandrock  of  Hamburgh,  states  that  American  oil  of  peppermint  is  adulterated 
with  oil  of  turpentine,  which  appears  to  be  the  product  of  some  other  species  of  pinus 
than  ours.  He  has  frequently  rectified  quantities  of  from  80  to  100  lbs.  of  the  American 
oil,  in  which  the  smell  of  oil  of  turpentine  was  distinctly  perceived ;  but  not  to  such 
a  degree  as  would  be  the  case  if  common  oil  of  turpentine  had  been  employed. 

Several  samples  of  English  oil  of  peppermint  were  found  by  the  author  to  be  mixed 
with  this  American  oil  of  peppermint,  the  price  of  which  is  only  five  or  six  marks  per 
pound.  Bley  has  also  perceived  this  smell  of  turpentine  in  the  oil  of  peppermint.  The 
smell,  however,  is  no  certain  criterion  in  this  case,  and  the  adulteration  is  better  dis- 
covered by  the  relation  to  iodine  and  alcohol,  and  by  the  specific  gravity.  Pure 
English  oil  of  peppermint  has  a  specific  gi*avity  of  0'910  to  0*920 ;  it  does  not  explode 
with  iodine,  but  forms  with  it  a  homogeneous  mass,  and  is  soluble  in  its  own  weight  of 
alcohol. 

The  American  oil,  in  which  a  great  proportion  of  oil  of  turpentine  is  supposed  to  be 
contained,  is  sold  by  the  name  of  crude  oil,  in  tin  bottles  of  twenty  pounds.  It  is  of  a 
yellowish  colour,  very  resinous,  often  as  thick  as  oil  of  bitter  almonds,  and  has  a  strong 
accessory  odour  of  oil  of  turpentine.  Its  specific  gravity  is  0*855  to  0*859.  When 
distilled  with  water,  half  of  it  passes  over  with  equal  parts  of  water,  then  the  proportion 
of  the  water  increases,  and  with  the  last  yellow,  somewhat  thicker  parts  of  the  oil  are 
distilled  over,  but  with  difficulty.  About  five-sixths  of  the  crude  oil  are  obtained  per- 
fectly clear  like  water.  The  first  half  of  the  rectified  oil  has  a  specific  weight  of  0*844, 
which  increases,  so  that  the  latter  portions  have  a  specific  gravity  of  0*875  to  0*880. 
The  oil  retains  now,  as  before,  the  smell  and  taste  of  turpentine,  is  only  dissolved  in  five 
or  six  parts  of  alcohol,  and  explodes  strongly  with  iodine.  The  resin  which  remains 
after  the  distillation  amounts  to  about  four  or  five  per  cent,  of  the  oil,  is  soft,  yellow- 
ish, turbid,  and  strongly  smells  of  the  oil.  Heated  for  some  time  at  a  slight  tempera- 
ture, it  changes  these  properties  for  all  those  of  the  pine  resin. 

10.  01.  Thymi  {Thyme).  This  oil  is  distinguished  by  no  peculiarity,  and,  in  moat 
cases  where  it  is  employed  as  perfume  or  externally,  its  pure  and  fine  smell  will  be  a 
sufficient  criterion.  By  its  slight  reaction  upon  iodine,  the  adulteration  with  turpen- 
tine oil  might  be  detected,  whilst  its  stronger  reaction  upon  chromate.  of  potash  would 
serve  to  detect  other  admixtures. 

11.  01.  Lavandulae  {Lavender).  This  delicate  oil  suffers  no  other  admixture  but  that 
of  alcohol  without  becoming  worthless,  and  in  the  inferior  cheap  qualities  which  are 
gold,  the  presence  of  alcohol  is  discoverable  by  the  specific  gravity.  Of  seventeen  sam- 
ples examined,  the  lowest  specific  gravity  of  the  inferior  oil  was  0*86 ;  that  of  the  best 


Snalitiea,  mostly  0*87  to  0*89.    The  peculiar  character  of  the  lavender  oil  by  which  it  ia 
istinguished,  with  regard  to  the  degree,  from  all  oils  obtained fr(m  the  labiaicR,  is  its  quick 
and  violent  fulmination  with  iodine,  and  the  entirely  changed,  pungent,  acidobalsamic 
smell  of  the  soft,  extract-like  residue.    This  character  is  invariab^  observed  in  all  genu- 
ine oils,  both  commercial,  and  those  prepared  in  the  laboratory.     The  inferior,  cheaper 
commercial  sort,-  does  not  fulminate.    An  intentional  addition  of  one-third  of  alcohol  did 
not  perceptibly  weaken  the  fulmination ;  also,  one  half  of  alcohol  did  not  destroy,  but 
only  weaken  it :  an  equal  volume  of  alcohol  being  added  to  the  oil  no  fulmination  took 
place,  but  a  lively  ebullition  and  development  of  yellowish-red  vapours.     A  moderate 
proportion  of  alcohol  cannot,  therefore,  be  discovered  by  these  reactions ;  for  this  purpose 
the  almost  indifferent  relation  of  the  pure  oil  to  santaline  is  a  safer  guide,  as  that  con- 
taining alcohol  dissolves  the  latter  readily  and  quickly.   An  adulteration  with  fulminating 
oils,  which  in  this  case  cannot  be  detected  by  iodine,  would  be  discovered  by  the  differing 
relation  to  caustic  potash.    The  alcoholic  solution  of  the  latter  forms  a  clear  solution 
with  lavender  oil,  to  which  it  communicates  a  dark  yellowish-red  brown  colour,  whilst  the 
other  oils  are  dissolved  in  it  with  diflUculty,  and  become  turbid,  with  but  a  slight  color- 
ation.    Among  the  better  tests,  we  may  also  reckon  the  deep  reddish-brown  colour  pro- 
duced by  sulphuric  acid  accompanied  by  a  strong  inspissation,  whilst  the  equally 
coloured  acid  has  a  slight  shade  of  yellow. 

12.  01.  Oubebarium  {Cubebs).  This  oil,  which  is  devoid  of  oxygen,  differs  from  others 
having  a  similar  composition  by  its  viscidity  and  weak  action  upon  iodine,  which  imparts 
to  it  at  the  beginning  of  the  reciprocal  reaction  a  violet  colour.  Even  absolute  alcohol 
in  large  proportions,  and  at  a  high  temperature,  forms  a  solution  which  is  mostly  clear; 
equal  weights  produce  a  very  turbid  solution,  throwing  down  flakes.  The  oil  which 
is  strongly  clouded  by  nitric  acid,  becomes  by  heat  only  pale  red,  but  is  decomposed 
and  converted  into  consistent  resin.  iSul^huric  acid  assumes  a  red  colour,  the  oil  be- 
coming crimson.  These  characteristics  will  suffice  for  this  oil,  which  is  already  difficult 
to  be  adulterated  on  account  of  its  viscidity  and  want  of  colour. 

13.  01.  Bergamottce  {Bergamot).     The  oils  of  the  aurantiaceai  are  in  a  still  higher 
degree  than  the  lavender  oil  protected  by  their  delicate  odour  from  adulteration,  ex- 
cept with  alcohol ;  on  the  other  hand,  a  mixture  of  these  oils  with  one  another  is  easier 
effected,  and  detected  with  greater  difficulty.     There  might,  however,  be  but  little  in- 
ducement for  doing  this,  except  in  the  case  of  ol.  flor.  aurant,  which  is  proportionately 
much  dearer  than  the  others.     The  similarity  of  the  respective  chemical  properties 
admits  also  here  of  no  better  test  than  the  smell.     The  unvarying  and  great  sp.  gr. 
(from  0-87  to  0*88)  will  serve  to  detect  any  admixture  of  alcohol     The  relation  which 
the  bergamot  oil  has  to  this  solvent^  shows  distinctly  the  difference  which  exists  between 
its  own  proportion  of  oxj-gen  and  that  of  the  other  oils  of  the  same  family;  it  is  readily 
dissolved  in  alcohol,  but^  like  the  other  oils,  it  makes,  at  least  when  fresh,  the  solution 
opaque.     It  is  also  distinguished  from  the  lemon  and  orange  oils,  by  being  easily  and 
clearly  dissolved  in  liquor  potasses.     This  difference  in  its  elements  also  is  manifested  in 
the  reaction  upon  iodine,  not  so  much  with  regard  to  its  fulminating  property,  which, 
although  weaker  than  in  the  lemon  oil,  is  rather  stronger  than  in  the  orange  oil,  but  bv 
the  homogeneous  nature  of  the  residue,  which,  in  the  two  last  mentioned  oils,  an^ 
in  all  oils  free  of  oxygen,  consists  of  two  combinations,  differing  in  consistency.    By  the 
incapacity  of  dissolving  santaline,  this  oil  is,  as  well  as  the  others  of  the  same  family, 
protected  against  an  admixture  of  alcohol.     One  part  of  alcohol  added  to  five  parts  of 
the  oil  is  hardly  able  to  impair  the  fulmination  ;  two  drops  of  alcohol  added  to  three 
drops  of  oil  produce  certainly  no  real  fulmination,  but  still  a  lively  reciprocal  action 
with  effervescence. 

14.  01.  Copaivce  {Gopaiva).  Small  proportions  of  turpentine-oil  cannot  easily  be  de- 
tected in  this  oil,  as  both  react  in  most  cases  in  the  same  manner.  A  chief  distinction 
IS  the  weaker  fulmination  of  the  ol.  copaiv.,  as  also  the  circumstance  that  the  latter 
requires  double  the  quantity  of  alcohol  for  its  solution,  which,  notwithstanding,  still 
remains  turbid.  Also  its  relation  to  sulphuric  acid  is  somewhat  different ;  the  latter 
becomes  yellowish  brown  red,  but  turpentine-oil  lively  yellowish-red. 

OIL  OF  VITRIOL,  is  the  old  name  of  concentrated  Sulphuric  Acid. 

OLEATES,  are  saline  compounds  of  oleic  acid  with  the  bases. 

ni'SP^^T  ^'^'  ^^  ^^®  uame  originally  given  to  bi-carburetted  hydrogen. 

OLEIC  ACrD,  is  the  acid  produced  by  saponifying  olive-oil,  and  then  separating 
thebase  by  dilute  sulphuric  or  muriatic  acid.     See  Fats,  and  Stearinb. 

This  acid  is  a  large  product  in  the  manufacture  of  stearic  acid,  and  has  hitherto 
been  of  inferior  value,  as  it  burned  very  ill  in  lamps ;  but  it  has  been  found  to  be 
capable  of  improvement  by  agitation  with  dilute  sulphuric  acid,  and  in  that  sUte 
eusceptible  of  affording  a  good  light  when  the  burner-tube  of  the  lamp  is  kept  cool  by 
enclosing  it  m  a  perforated  small  plate,  which  prevents  the  flame  from  heating  the  Bai4 


Vou  n. 


2R 


306 


OPIUM. 


OPIUM. 


307 


burner  email  pipe,  in  which  the  wick  u  supported.    Messrs.  Humfrey  and  Wilson  hAT« 
patented  it. 

OLEINE,  is  the  thin  oily  part  of  fats,  naturally  associated  in  them  with  glycerine, 
marsrarine)  and  stearine. 
OLIBANUM  is  a  ^m-resin,  used  only  as  incense  in  Roman  Catholic  churches. 
OLIVE  OIL.    See  Oils,  unctuous. 

ONYX,  an  ornamental  stone  of  little  value ;  a  subspecies  of  quartz. 
OOLITE  is  a  species  of  limestone  composed  of  globules  clustered  together,  commonly 
without  any  visible  cement  or  base.  These  vary  in  size  from  that  of  small  pin-heads  to 
peas ;  they  sometimes  occur  in  concentric  layers,  at  others  they  are  compact,  or  radiated 
from  the  centre  to  the  circumference ;  in  which  case,  the  oolite  is  called  roogenstein  by  the 
German  mineralogists.  In  geology  the  oolitic  series  includes  all  the  strata  between  the 
iron  sand  above  and  the  red  marl  below.  It  is  the  great  repository  of  the  best  architect* 
oral  materials  which  the  midland  and  eastern  parts  of  England  produce ;  it  is  divided  into 
three  systems  : — 

1.  The  upper  oolite j  including  the  argillo-calcareous  Purbeck  strata,  which  separate  the 
iron  and  oolitic  series ;  the  oolitic  strata  of  Portland,  Tisbury,  and  Aylesbury  ;  the  calca- 
reous sand  and  concretions,  as  of  Shotover  and  Thame ;  and  the  argillo-calcareous  forma- 
tion of  Kimmeridge,  the  oak  tree  of  Smith. 

2.  The  middle  oolite ;  the  oolitic  strata  associated  with  the  coral  rag  ;  calcareous  sand 
and  grit ;  great  Oxford  clay,  between  the  oolites  of  this  and  the  following  system. 

3.  The  lower  oolite;  which  contains  numerous  oolitic  strata,  occasionally  subdivided  by 
thin  argillaceous  beds ;  including  the  cornbrash,  forest  marble,  schistose  oolite,  and  sand 
of  Stonesfield  and  Hinton,  great  oolite  and  inferior  oolite  ;  calcareo-silicious  sand  passing 
into  the  inferior  oolite ;  great  argillo-calcareous  formation  of  lias,  and  lias  marl,  constitu* 
ting  the  base  of  the  whole  series. 

These  formations  occupy  a  zone  30  miles  broad  in  England. 

OOST,  or  OAST ;  tlie  trivial  or  provincial  name  of  the  stove  in  which  the  picked  hops 
are  dried. 

OPAL  ;  an  ornamental  stone  of  moderate  value.     See  Lapidary. 

OPERAMETER  is  the  name  given  to  an  apparatus  patented  in  February,  1829,  by 
Samuel  Walker,  cloth  manufacturer,  in  the  parish  of  Leeds.  It  consists  of  a  train  of 
toothed  wheels  and  pinions  enclosed  in  a  box,  having  indexes  attached  to  the  central 
arbor,  like  the  hands  of  a  clock,  and  a  dial  plate  ;  whereby  the  number  of  rotations  of  a 
shaA  projecting  from  the  posterior  part  of  the  box  is  shown.  If  this  shaft  be  connected 
by  any  convenient  means  to  the  working  parts  of  a  gig  mill,  shearing  frame,  or  any  other 
machinery  of  that  kind  for  dressing  cloths,  the  number  of  rotations  made  by  the  operating 
machine  will  be  exhibited  by  the  indexes  upon  the  dial  plate  of  this  apparatus.  In  dress- 
ing cloths,  it  is  often  found  that  too  little  or  too  much  work  has  been  expended  upon  them, 
in  consequence  of  the  unskilfulness  or  inattention  of  the  workmen.  By  the  use  of  the 
operameter,  that  evil  will  be  avoided,  as  the  master  may  regulate  and  prescribe  beforehand 
by  the  dial  the  number  of  turns  which  the  wheels  should  perform. 

A  similar  clock-work  mechanism,  called  a  counter^  has  been  for  a  great  many  years 
employed  in  the  cotton  factories  to  indicate  the  number  of  revolutions  of  the  main  shaft 
of  the  mill,  and  of  course  the  quantity  of  yarn  that  might  or  should  be  spun,  or  of  cloth 
that  might  be  woven  in  the  power  looms.  A  common  pendulum  or  spring  clock  it 
MDunonly  set  up  alongside  of  the  counter ;  and  sometimes  the  indexes  of  both  are  rega* 
lated  to  go  together,  when  the  mill  performs  its  average  work. 

OPIUM,  is  the  juice  which  exudes  from  incisions  made  in  the  heads  of  ripe  poppies, 
{papaver  somniferumy)  rendered  concrete  by  exposure  to  the  air  and  the  sun.  The  best 
opium  which  is  found  in  the  European  markets  comes  from  Asia  Minor  and  Egypt ; 
what  is  imported  from  India  is  reckoned  inferior  in  quality.  This  is  the  most  valuable  of 
all  the  vegetable  products  of  the  gum-resin  family :  and  very  remarkable  for  the  complexity 
of  its  chemical  composition.  Though  examined  by  many  able  analysts,  it  still  requires 
farther  elucidation. 

Opium  occurs  in  brown  lumps  of  a  rounded  form  about  the  size  of  the  fist,  and 
often  larger ;  having  their  surface  covered  with  the  seeds  and  leaves  of  a  species  of 
rumex,  for  the  purpose  of  preventing  the  mutual  adhesion  of  the  pieces  in  their  semi- 
indurated  state.  These  seeds  are  sometimes  introduced  into  the  interior  of  the  masses 
to  increase  their  weight ;  a  fraud  easily  detected  by  cutting  them  across.  Good  opium 
»«  hard  in  the  cold,  but  becomes  flexible  and  doughy  when  it  is  worked  between  the  hot 
hands.  It  has  a  characteristic  smell,  which  by  heat  becomes  strongei,  «ind  very  offensive 
to  the  nostrils  of  many  persons.  I(  has  a  very  bitter  taste.  Watei  first  softens,  and 
then  reduces  it  to  a  pasty  magma.  Proof  spirit  digested  upon  opium  forms  laudanum, 
being  a  better  solution  of  its  active  parts  than  can  be  obtained  by  either  water  or  strong 
alcohol  alone.  Water  distilled  from  it  acquires  its  peculiar  smell,  but  carries  over  no 
Yolatile  oil. 


Opium  was  analyzed  by  Bncholz  ana  Braconnot,  but  at  a  period  anterior  to  the 
knowledge  of  the  alkaline  properties  of  morphia  and  opian  (narcotine).  Bucholz 
found  in  100  parts  of  it,  90  of  resin  ;  30*4  of  gum;  35-6  of  extractive  matter  ;  4*8  of 
caoutchouc ;  11-4  of  gluten;  2-0  of  ligneous  matter,  as  seeds,  leaves,  &.c. ;  6-8  of  water 
and  loss.  John,  who  made  his  analysis  more  recently,  obtained  2-0  parts  of  a  rancid 
nauseous  fat ;  12-0  of  a  brown  hard  resin ;  10*0  of  a  soft  resin ;  2  of  an  elastic  substance ; 
12-0  of  morphia  and  opian ;  1-0  of  a  balsamic  extract ;  25*0  of  extractive  matter ;  2-5  of 
the  meconates  of  lime  and  magnesia ;  18*5  of  the  epidermis  of  the  heads  of  the  poppy ; 
15  of  water,  salts,  and  odorous  matter. 

In  the  Numbers  of  the  Quarterly  Journal  of  Science  for  January  and  June,  1830, 
I  published  two  papers  upon  opium  and  its  tests,  containing  the  results  of  researches  made 
upon  some  porter  which  had  been  fatally  dosed  with  that  drug ;  for  which  crime,  a  man 
and  his  wife  had  been  capitally  punished,  about  a  year  before,  in  Scotland.*  From  the 
first  of  these  papers  the  following  extract  is  made  : — 

"  Did  the  anodyne  and  soporific  virtue  of  opium  reside  in  one  definite  principle 
chemical  analysis  might  furnish  a  certain  criterion  of  its  powers.  It  has  been  pretty 
generally  supposed  that  this  desideratum  is  supplied  by  Sertiirner's  discovery  of  morphia. 
Of  this  narcotic  alkali  not  more  than  7  parts  can  be  extracted  by  the  most  rigid 
analysis  from  100  of  the  best  Turkey  opium ;  a  quantity,  indeed,  somewhat  above  the 
average  result  of  many  skilful  chemists.  Were  morphia  the  real  medicinal  essence  of 
the  poppy,  it  should  display,  when  administered  in  its  active  saline  state  of  acetate,  an 
operation  on  the  living  system  commensurate  in  energy  with  the  fourteen-fold  concen- 
tration which  the  opium  has  undergone.  But  so  far  as  may  be  judged  from  the  most 
authentic  recent  trials,  morphia  in  the  acetate  seems  to  be  little,  if  any,  stronger  as  a 
narcotic  than  the  heterogeneous  drug  from  which  it  has  been  eliminated.  Mr.  John 
Murray's  experiments  would,  in  fact,  prove  it  to  be  greatly  weaker;  for  he  gave  2 
drachms  of  superacetate  of  morphia  to  a  cat,  without  causing  any  poisonous  disorder. 
This  is  perhaps  an  extreme  case,  and  may  seem  to  indicate  either  some  defect  in  the 
preparation,  or  an  uncommon  tenacity  of  life  in  the  animal.  To  the  same  effect 
Lassaigne  found  that  a  dog  lived  12  hours  after  36  grains  of  acetate  of  morphia  in 
watery  solution  had  been  injected  into  its  jugular  vein.  The  morphia  meanwhile  was 
entirely  decomposed  by  the  vital  forces,  for  none  of  it  could  be  detected  in  the  blood 
drawn  from  the  animal  at  the  end  of  that  period.  Now,  from  the  effects  produced  by  5 
grains  of  watery  extract  of  opium,  injected  by  Orfila  into  the  veins  of  a  dog,  we  may  con- 
dude  that  a  quantity  of  it,  equivalent  to  the  above  dose  of  the  acetate  of  morphia,  would 
have  proved  speedily  fatal. 

"  Neither  can  we  ascribe  the  energy  of  opium  to  the  white  crystalline  substance  called 
narcotiruy  or  opian^  extracted  from  it  by  the  solvent  agency  of  sulphuric  ether ;  for  Orfila 
assures  us  that  these  crystals  may  be  swallowed  in  various  forms  by  man,  even  to  the 
amount  of  2  drachms  in  the  course  of  12  hours,  with  impunity ;  and  that  a  drachm  of  it 
dissolved  in  muriatic  or  nitric  acid  may  be  administered  in  the  food  of  a  dog  without 
producing  any  inconvenience  to  the  animal.  It  appears,  however,  on  the  same  authority, 
that  30  grains  of  it  dissolved  in  acetic  or  sulphuric  acid  caused  dogs  that  had  swallowea 
the  dose  to  die  under  convulsions  in  the  space  of  24  hours,  while  the  head  was  thrown 
backwards  on  the  spine.  Oil  seems  to  be  the  most  potent  menstruum  of  narcotine ;  foi 
3  grains  dissolved  in  oil  readily  kill  a  dog,  whether  the  dose  be  introduced  into  the  stom- 
ach or  into  the  jugular  vein. 

**  Since  a  bland  oil  thus  seems  to  develop  the  peculiar  force  of  narcotine,  and  sine* 
opium  affords  to  ether,  and  also  to  ammonia,  an  unctuous  or  fatty  matter,  and  a  resin 
(the  caoutchouc  of  Bucholz)  to  absolute  alcohol,  we  are  entitled  to  infer  that  the  activity 
of  opium  is  due  to  its  state  of  composition,  to  the  union  of  an  oleate  or  margarate  of  nar- 
eotine  with  morphia.  The  meconic  acid  associated  with  this  salifiable  base  has  no  nar- 
cotic power  by  itself,  but  may  probably  promote  the  activity  of  the  morphia." 

Opian  or  narcotine,  and  morphia,  may  be  well  prepared  by  the  following  process. 
The  watery  infusion  of  opium  being  evaporated  to  the  consistence  of  an  extract,  every 
3  parts  are  to  be  diluted  with  one  and  a  half  parts  in  bulk  of  water,  and  then  mixed  in 
a  retort  with  20  parts  of  ether.  As  soon  as  5  parts  of  the  ether  have  been  distilled 
over,  the  narcotic  salt  contained  in  the  extract  will  be  dissolved.  The  fluid  contents  of 
the  retort  are  to  be  poured  hot  into  a  vessel  apart,  and  the  residuum  being  washed  with 
6  other  parts  of  ether,  they  are  to  be  added  to  the  former.  Crystals  of  narcotine  will  be 
obtained  as  the  solution  cools.  The  remaining  extract  is  to  be  diluted  in  the  retort 
With  a  little  water,  and  the  mixture  set  aside  in  a  cool  place.  After  some  time,  some 
narcotine  will  be  found  crystallized  at  the  bottom.  The  supernatant  liquid  thus 
freed  trom  narcotine  being  decanted  oflT,  is  to  be  treated  with  caustic  ammonia;  and 

♦A  country  merchant  trmrellin^in  »  rteam-boat  upon  the  river  Clyde,  who  had  incautiouily  di»plaf«i 
•  fooa  ueal  ot  money,  wa.  poisoned  with  porter  chuyad  with  laudanum.  The  contanta  of  the  daad^Ma-a 
■tomaeh  were  aent  to  me  for  analyna.  ***"* 


308 


ORCINK. 


tfie  precipitate  thrown  upon  a  filter.  This,  when  well  washed  and  dried,  is  to  be 
boiled  with  a  quantity  of  spirits  of  wine  at  0-84,  equal  to  thrice  the  weight  of  the 
opium  employed,  contaming  6  parts  of  animal  charcoal  for  every  hundred  parts  of  the 
drug.  The  alcoholic  solution  being  filtered  hot,  affords,  on  cooling,  colourless  crystals 
of  morphia.  *^ 

This  alkali  may  be  obtained  by  a  more  direct  process,  without  alcohol  or  ether. 
A  solution  of  opium  in  vinegar  is  to  be  precipitated  by  ammonia ;  the  washed  preci- 
pitate is  to  be  dissolved  in  dilute  muriatic  acid,  the  solution  is  to  be  boiled  along  with 
powdered  bone  black,  filtered,  and  then  precipitated  by  ammonia.  This,  when  washed 
upon  a  filter  and  dried,  is  white  morphia,  which  may  be  dissolved  in  hot  alcohol  if 
fine  crystals  be  wanted.     See  Morphia.  ' 

Analysis  of  Opium.— R&M  an  ounce  of  the  opium  to  be  examined  is  cut  into  small 
pieces  and  bruised  ip  a  mortar  with  spirit  of  alcohol  at  71° ;  the  fluid  is  then  expressed 
through  linen,  and  the  refuse  washed  with  from  10  to  12  drachms  of  the  same  alcohol ; 
the  alcoholic  solution  is  then  to  be  filtered  into  a  glass  containing  one  drachm  of  spirits 
of  amraonia.  In  12  hours'  time  all  the  morphia,  with  some  narcotine  and  meconate  of 
ammonia,  will  have  become  deposited.  The  separation  of  the  gritty  crystals  of  mor- 
I>hia,  which  adhere  to  the  sides  of  the  vessel  from  the  light,  pointed  crystals  of  narco- 
tine, which  for  the  most  part  float  in  the  fluid,  is  to  be  effected  by  decantation,  according 
to  Guillermond,  but  this  plan  does  not  leave  the  morphia  free  from  narcotine.  In  order 
effectually  to  separate  the  narcotine,  the  adhering  meconate  of  ammonia  must  be  re- 
moved by  washing  in  water,  and  then  shaking  the  crystals  in  pure  ether,  or  better  still 
in  chloroform,  by  which  the  narcotine  is  readily  dissolved,  while  the  morphia  remains 
entirely  insoluble.  After  this  treatment  the  morphia  is  left  behind  in  rather  large  gritty 
crystals,  slightly  discoloured.  This  process  may  be  varied  by  employing  boiling  alco- 
hol and  powdered  opium,  and  adding  the  solution,  still  hot»  to  the  solution  of  ammonia. 
According  to  Guillermond,  16  grammes  of  opium  should  yield  at  least  125  grammes 
or  8-33  per  cent  Reich  estimates  10  per  cent,  and  others  12  per  cent  The  author 
gives  the  percentage  of  morphia  which  is  obtained  by  the  various  processes  of  differ- 
ent experimenters,  and  states  that  the  largest  proportion  (13-60  per  cent)  is  procured 
by  the  modification  of  Guillermond's  method,  now  described,  which  he  also  considers 
ihe  simplest  and  most  certain  for  ascertaining  the  proportion  of  morphia. 

The  following  process  is  recommended  by  Dr.  Rieget  for  the  detection  of  small 
gaantities  of  opium-  To  the  suspected  substance,  some  potash  is  to  be  added,  and 
then  it  is  shaken  with  ether.  A  strip  of  white  blotting  paper  is  to  be  moistened  with 
the  solution,  several  times  repeated.  When  dry,  the  paper  is  then  to  be  moistened 
with  muriatic  acid,  and  exposed  to  the  steam  of  hot  water ;  if  opium  be  present^  the 
paper  will  be  more  or  less  coloured  red- 
Imported,  in  1850,  126,102  lbs.,  in  1851,  106,113  lbs. ;  retained  for  consumption, 
1850,  42,324  lbs.,  1857,  50,368  lbs. ;  exported,  1850,  87,451  lbs.,  1851,  65,640  lbs. :  duty 
tweived,  1860,  2,222/L,  1861,  2,645/.  ^ 

OPOBALSAM  is  the  balsam  of  Pern  in  a  dry  state. 

OPOPONAX  is  a  gum-resin  resembling  gum  ammoniac.     It  is  occasionally  used  m 
■ledicine. 

ORANGE  DYE  is  given  by  a  mixture  of  red  and  yellow  dyes  in  various  proportions. 
Annotto  alone  dyes  orange ;  but  it  is  a  fugitive  color. 

ORCINE  is  the  name  of  the  coloring  principle  of  the  lichen  dealbatua.  The 
lichen  dried  and  pulverized  is  to  be  exhausted  by  boiling  alcohol.  The  solution 
filtered  hot,  lets  fall  in  the  cooling  crystalline  flocks,  which  do  not  belon?  to  the 
coloring  matter.  The  supernatant  alcohol  is  to  be  distilled  off,  the  residuum  is  to 
be  evaporated  to  the  consistence  of  an  extract,  and  triturated  with  water  till  this  liquid 
will  dissolve  no  more.  The  aqueous  solution  reduced  to  the  consistence  of  sirup,  and 
left  to  Itself  in  a  cool  place,  lets  fall,  at  the  end  of  a  few  days,  long  brown  brittle 
needles,  which  are  to  be  freed  by  pressure  from  the  mother  water,  and  dried.  That 
water  being  treated  with  animal  charcoal,  filtered  and  evaporated,  will  yield  a  second 
crop  of  crystals.  These  are  orcine.  Its  taste  is  sweet  and  nauseous ;  it  melts  readily 
in  a  retort  into  a  transparent  liquid,  and  distils  without  undergoing  any  changes.  It  is 
soluble  in  water  and  alcohol.  Nitric  acid  colors  it  blood-red  ;  which  color  afterwards 
disappears.  Subacetate  of  lead  precipitates  it  completely.  Its  conversion  into  the  archil 
red  IS  effected  by  the  action  of  an  alkali,  in  contact  with  the  air.  When  dissolved, 
for  example,  in  ammonia,  and  exposed  to  the  atmosphere,  it  Ukes  a  dirty  brown  red 
hue ;  but  when  the  orcine  is  exposed  to  air  charged  with  vapors  of  ammonia,  it  assumes 
by  degrees  a  fine  violet  color.  To  obtain  this  result,  the  orcine  in  powder  should  be 
placed  in  a  capsule,  alongside  of  a  saucer  containing  water  of  ammonia ;  and  both 
should  be  covered  by  a  large  bell  glass ;  whenever  the  orcine  has  acquired  a  dark 
bvown  cast,  it  must  be  withdrawn  from  under  the  bell,  and  the  excess  of  ammonia  be 
tilowed  to  volatilize.    As  soon  as  the  smell  of  ammonia  is  gone^  the  orcine  is  to  be  dia* 


ORNAMENTAL  BRASS  CASTINGa  309 

solved  in  water ;  and  then  a  few  drops  of  ammonia  being  poured  into  Ue  brownish 
liquid,  It  assumes  a  magnificent  reddish-violet  color.  Acetic  acid  precipitates  the  red 
lake  of  lichen. 

ORES  (Mines,  Fr. ;  Erze,  Germ.),  are  the  mineral  bodies  which  contain  so  much 
metal  as  to  be  worth  the  smelting,  or  being  reduced  by  fire  to  the  metaUic  state.  The 
substances  naturally  combined  with  meUls,  which  mask  their  metallic  characters,  are 
chiefly  oxygen,  chlorine,  sulphur,  phosphorus,  selenium,  arsenic,  water,  and  several  acids, 
of  which  the  carbonic  is  the  most  common.  Some  metals,  as  gold,  silver,  platinum,  often 
occur  in  the  metallic  state,  either  alone,  or  combined  with  other  metals,  constituting  what 
are  called  native  alloys. 

I  have  described  in  the  article  Mine,  the  general  structure  of  the  great  metallic 
repositories  within  the  earth,  as  well  as  the  most  approved  jnethods  of  hringine  them 
to  the  surface ;  and  in  the  article  Metallurgy,  the  various  mechanical  and  chemical 
operations  requisite  to  reduce  the  ores  into  pure  metals.  Under  each  particular  metaL 
moreover,  in  its  alphabetical  place,  wiU  be  found  a  systematic  account  of  its  most  imoor! 
tant  ores.  *^ 

Relatively  to  the  theory  of  the  smelting  of  ores,  the  following  observations  mav 
be  made.     It  is  probable  that  the  coaly  matter  employed  in  that  process  is  not  the 
immediate  agent  of  their  reduction ;  but  the  charcoal  seems  first  of  all  to  be  transformed 
by  the  atmospherical  oxygen  into  the  oxyde  of  carbon ;  which  gaseous  product  then 
surrounds  and  penetrates  the  interior  substance  of  the  oxydes,  with  the  effect  of  decom- 
posing them,  and  carrying  off  their  oxygen.    That  this  is  the  true  mode  of  action  it 
evident  from  the  well-known  facts,  that  bars  of  iron,  stratified  with  pounded  charccJaL 
in  the  steel  cementation-chest,  most  readily  absorb  the  carbonaceous  principle  to  thSr 
innermost  centre,  while  theu-  surfaces  get  blistered  by  the  expansion  of  carbureted 
gases  formed  within ;  and  that  an  intermixture  of  ores  and  charcoal  is  not  always 
necessary  to  reduction,  but  merely  an  interstratification  of  the  two,  without  intimate 
contact  of  the  particles.     In  this  case,  the  carbonic  acid  which  is  generated  at  the  lower 
surfaces  of  contact  of  the  strata,  rising  up  through  the  fii^t  bed  of  ignited  charcoal   be- 
comes converted  into  carbonic  oxyde;  and  this  gaseous  matter,  passing  up  through  the 
next  layer  of  ore,  seizes  its  oxygen,  reduces  it  to  metal,  and  is  itself  thereby  transformed 
once  more  into  carbonic  acid;  and  so  on  in  continual  alternation.     It  may  be  hud 
down,  however,  as  a  general  rule,  that  the  reduction  is  the  more  rapid  and  complete  the 
more  Jl^timate  the  mixture  of  the  charcoal  and  the  metallic  oxyde  has  been,  because  the 
formation  of  both  the  carbonic  acid  and  carbonic  oxyde  becomes  thereby  i^re  easy  and 
direct.    Indeed,  the  cementation  of  iron  bars  into  steel  will  not  succeed,  unless  the 
charcoal  be  so  porous  as  to  contain,  interspersed,  enough  of  air  to  favor  the  commence- 
ment of  its  conversion  into  the  gaseous  oxyde;  thus  acting  like  a  ferment  in  brewing. 
Hence  also  finely  pulverized  charcoal  does  not  answer  weU ;  unless  a  quantity  of  grouui 
iron  cinder  or  oxyde  of  manganese  be  blended  with  it,  to  afford  enough  of  oxygen  to  be- 
gin  the  generation  of  carbonic  oxyde  gas;  whereby  the  successive  transformations  into 
acid,  and  oxyde,  are  put  in  train. 

ORMOLU.  The  ormolu  of  the  brass  founder,  popularly  known  as  an  imitation  of 
red  gold,  18  extensively  used  by  the  French  workmen  in  metals.  It  is  generally  found 
m  combination  with  grate  and  stove  work.  It  is  composed  of  a  greater  proportion  of 
copper  and  less  zinc  than  ordinary  brass,  is  cleaned  readily  by  means  of  acid,  and  is 
burnished  with  facility.  To  give  this  material  the  rich  appearance,  it  is  not  unfre- 
quently  brightened  up  after  "  dipping  "  (that  is  cleaning  in  acid)  by  means  of  a  scratch 
brush  (a  brush  made  of  fine  brass  wire^  the  action  of  which  helps  to  produce  a  very 

niTv  Al?J.t 'l^  aV"^^^^^       ^*  '*  protected  from  tarnish  by  the  applicafion  of  lacque?. 

OUxNAMEIsTAL  BRASS  CASTINGS.  Brass  castings  are  produced  in  san^  by 
means  of  patterns.  The  making  of  these  patterns  or  models  is  a  work  involving  nJ 
t^rlmtr^K  f  ^^  '^"  *?^  knowledge ;  the  simpler  kinds  are  made  by  the  ordinary 
tZ  h^n^r^f  f1  ^°j;?««»  ^here  figures,  foliage,  or  animals  are  introduced,  the  eye  anJ 
^  wax  r  o^tTn  /  J"- T^  necessary.  The  object  is  first  designed,  then  modelled 
patl^n  or'mTdel^r  1"^^^^^^^^    '  ''  "  ^'^"^  "^^  "^  ""^'^  ^^^  ^^^^^  '  ^^  ^-^  ^« 

anl^fiToTf^r^''^*''  ?^«^°]P'e  forms  are  readily  copied;  but  when  the  human  figure, 
!ff Tfti'K         ^^^^  '?  introduced,  the  difficulty  U  increased.     The  castings  can  onfy  be 

Sfted  outfn'^lTn^^^^^^  Tf"^  ^^^'  ^^"?^"^g  r«^««f  «^^<i  ^hich  are^made  up  and 
alfn  introdS  P^.^;«,^%l>«fore  the  mode! canU  removed,  and  which  afterward  are 

bfst  exD  dn  th«  m.^n  f"^"^  ^^^^^^  *^^  "^'^^  *^^  «^*°^  "P^^  '^  i^  examined,  wiU 
^ows  whin  1  eo?«  h««  ^  ""^  -^^'^  '^"*^"  ^"^^  «^  compartment  marked  thereon^  and 
nroLJa  Wr  fmni  •^^'^  '"  .*  "^^^^^  ^*^^^"g-  ^o  put  the  sand  in  a  condition  to 
duceHhe  moulZ^.lZrh  P^.^^^^^  ^^^^coal  is  dusted  upon  it,  the  cores  being  intro- 
duced,  the  moulds  closed  having  been  previously  dried,  and  runners  made  for  the  m- 


310 


OXALIC  ACID. 


OXALIC  ACID. 


311 


troduction  of  the  metal  (which  is  usually  melted  in  earthen  or  clay  crucibles,  and  in 
an  air  furnace,  the  fuel  used  being  coke),  follow  and  complete  the  operation. 

ORPIMENT  (Ens.  and  Fr.,  Yellow  sulphuret  of  arsenic ;  Operment,  Rauschgelb,  Germ.), 
occurs  in  indistinct  crystalline  particles,  and  sometimes  in  oblique  rhomboidal  prisms ; 
bat  for  the  most  part,  in  kidney  and  other  imitative  forms ;  it  has  a  scaly  and  granular 
aspect ;  texture  foliated,  or  radiated ;  fracture  small  granular,  passing  into  conchoidal ; 
splintery,  opaque,  shining,  with  a  weak  diamond  lustre ;  lemon,  orange,  or  honey  yellow ; 
sometimes  green  ;  specific  gravity,  3-44  to  3-6.  It  is  found  in  floetz  rocks,  in  marl,  clay, 
sand-stone,  along  with  realgar,  lead-glance,  pyrites,  and  blende,  in  many  parts  of  the 
world.    It  volatilizes  at  the  blowpipe.     It  is  used  as  a  pigment. 

The  finest  specimens  come  from  Persia,  in  brilliant  yellow  masses,  of  a  lamellar  tex- 
ture, called  golden  orpiment. 

Artificial  orpiment  is  manufactured  chiefly  in  Saxony,  by  subliming  in  cast  iron  cucur- 
bits, surmounted  by  conical  cast-iron  capitals,  a  mixture  in  due  proportions  of  sulphur 
and  arsenious  acid  (white  arsenic).  As  thus  obtained,  it  is  in  yellow  compact  opaque 
masses,  of  a  glassy  aspect ;  afibrding  a  powder  of  a  pale  yellow  color.  Genuine 
orpiment  is  often  adulterated  with  an  ill-made  compound;  which  is  sold  in  this 
country  by  the  preposterous  name  of  king's  yellow.  This  fictitious  substance  is  fre- 
quently nothing  else  than  white  arsenic  combined  with  a  little  sulphur ;  and  is  quite 
soluble  in  water.  Il  is  therefore  a  deadly  poison,  and  has  been  administered  with 
criminal  intentions  and  fatal  effects.  I  had  occasion,  some  years  ago,  to  examine  such 
a  specimen  of  king's  yellow,  with  which  a  woman  had  killed  her  child.  A  proper 
insoluble  sulphuret  of  arsenic,  like  the  native  or  the  Saxon,  may  be  prepared  by  trans- 
mitting sulphureted  hydrogen  gas  through  any  arsenical  solution.  It  consists  of  38-09 
tulphur,  and  60-92  of  metallic  arsenic,  and  is  not  remarkably  poisonous.  The  finest 
kinds  of  native  orpiment  are  reserved  for  artists;  the  inferior  are  used  for  the  indigo 
Tat     They  are  all  soluble  in  alkaline  lyes,  and  in  water  of  ammonia. 

OR YCTNOGNOSY,  is  the  name  given  by  Werner  to  the  knowledge  of  minerals ; 
and  is  therefore  synonymous  with  the  English  term  Mineralogy. 

OSTEOCOLLA,  is  the  ^lue  obtained  from  bones,  by  removing  the  earthy  phospliates 
with  muriatic  acid,  and  dissolving  the  cartilaginous  residuum  in  water  at  a  temperature 
considerably  above  the  boiling  point,  by  means  of  a  digester.  It  is  a  very  inditferent 
article. 

OSMIUM,  is  a  metal  discovered  by  Mr.  Tennant  in  1803,  among  the  grains  of  native 
platinum.  It  occurs  also  associated  with  the  ore  of  iridium.  As  it  has  not  been  ap- 
plied to  any  use  in  the  arts,  I  shall  reserve  any  chemical  observations  that  the  subject 
may  require  for  the  article  Platinum. 

OTTO  OF  ROSES.— Meatis  of  determining  the  nurity  of  the  Otto  of  Roses.— Sul- 
phuric acid  test. — One  or  two  drops  of  the  oil  to  be  tested  is  put  into  a  watch-glass ; 
the  same  number  of  drops  of  very  concentrated  sulphuric  acid  are  added,  and  the  two 
fluids  mixed  with  a  glass  rod.  All  the  oils  are  rendered  more  or  less  brown  by  this 
proceeding ;  but  the  otto  of  roses  retains  the  purity  of  its  odour.  The  oil  of  geranium 
acquires  a  strong  and  disagreeable  odour,  which  is  perfectly  characteristic. 

OXALATES  are  saline  compounds  of  the  bases  with 

OXALIC  ACID  (jScide  oxaliquey  Fr. ;  Sauerkleesaiire,  Germ.),  which  is  the  objcci 
of  a  considerable  chemical  manufacture.  It  is  usually  prepared  upon  the  small  scale  by 
digesting  four  parts  of  nitric  acid  of  specific  gravity  1-4,  upon  one  part  of  sugar,  in  a  glass 
retort ;  but  on  the  large  scale,  in  a  series  of  salt-glazed  stoneware  pipkins,  two  thirds 
fiUed,  and  set  in  a  water  bath.  The  addition  of  a  little  sulphuric  icid  has  been  found  to 
increase  the  product.  15  pounds  of  sugar  yield  fully  17  pounds  c.  the  cr)-sta]Iine  acid. 
This  acid  exists  in  the  juice  of  wood  sorrel,  the  oxalis  acetosella,  in  the  slate  of  a  bi- 
oxalate ;  from  which  the  salt  is  extracted  as  an  object  of  commerce  in  Sw^itzerland,  and 
sold  under  the  name  of  salt  of  sorrel,  or  sometimes,  most  incorrectly,  under  that  of  salt 
of  lemons. 

Some  prefer  to  make  oxalic  acid  by  acting  upon  4  parts  of  sugar,  with  24  parts  of 
nitric  acid  of  specific  gravity  1-220,  heating  the  solution  in  a  retort  till  the  acid  begins 
to  decompose,  and  keeping  it  at  this  temperature  as  long  as  nitrous  gas  is  disengaged. 
The  sugar  loses  a  portion  of  its  carbon,  which  combining  with  the  oxygen  of  the  nitric 
acid,  becomes  carbonic  acid,  and  escapes  along  with  the  deutoxyde  of  nitrogen.  The  re- 
maining carbon  and  hydrogen  of  the  sugar  being  oxydized  at  the  expense  of  the  nitric  acid, 
generate  a  mixture  of  two  acids,  the  oxalic  and  the  malic.  Whenever  gas  ceases  to  issue, 
the  retort  must  be  removed  from  the  source  of  heat,  and  set  aside  to  cool;  the  oxalic  acid 
crystallizes,  but  the  malic  remains  dissolved.  After  draining  these  crystals  upon  a  filter 
funnel,  if  the  brownish  liquid  be  further  evaporated,  it  will  furnish  another  crop  of  them. 
Vie  residuary  mother  water  is  generally  regarded  as  malic  acid,  but  it  also  contains  both 
oxalic  and  nitric  acids ;  and  if  heated  with  6  parts  of  the  latter  acid,  it  will  yield 
a  good  deal  more  oxalic  acid  at  the  expense  of  the  malic.      The  brown  crystals 


BOW  formed  being,  however,  penetrated  with  nitric,  as  well  as  malic  acid,  must  be 
allowed  to  dry  and  eflloresce  in  warm  dry  air,  whereby  the  nitric  acid  will  be  got  rid  of 
without  injury  to  the  oxalic.  A  second  crystallization  and  efflorescence  will  entirely 
dissipate  the  remainder  of  the  nitric  acid,  so  as  to  afford  pure  oxalic  acid  at  the  third 
crystallization.  Sugar  affords,  with  nitric  acid,  a  purer  oxalic  acid,  but  in  smaller 
quantity,  than  saw-dust,  glue,  silk,  hairs,  and  several  other  animal  and  vegetable 
substances. 

Oxalic  acid  occurs  in  aggregated  prisms  when  it  crystallizes  rapidly,  but  in  tables  of 
greater  or  less  thickness  when  slowly  formed.  They  lose  their  water  of  crystallization 
in  the  open  air,  fall  into  powder,  and  weigh  0-28  less  than  before ;  but  still  retain 
0-14  parts  of  water,  which  the  acid  does  not  part  with  except  in  favor  of  another  oxyde, 
as  when  it  is  combined  with  oxyde  of  lead.  The  effloresced  acid  contains  20  per  cent,  of 
water,  according  to  Berzelius.  By  my  analysis,  the  crystals  consist  of  three  prime 
equivalents,  of  water  =  27,  combined  with  one  of  dry  oxalic  acid  =  36 ;  or  in  100 
parts,  of  42-86  of  water  with  57*14  of  acid.  The  acid  itself  consists  of  2  atoms  of  carbon 
=  12,  -f-  3  of  oxygen  =  24 ;  of  which  the  sum  is,  as  above  stated,  36.  This  acid  has  a 
sharp  sour  taste,  and  sets  the  teeth  on  edge ;  half  a  pint  of  water,  containing  only  1  gr.  of 
acid,  very  sensibly  reddens  litmus  paper.  Nine  parts  of  water  dissolve  one  part  of  the 
crystals  at  60^  F.  and  form  a  solution,  of  spec.  grav.  1*045,  which  when  swallowed  acts 
as)  a  deadly  poison.  Alcohol  also  dissolves  this  acid.  It  differs  from  all  the  other  acid  pro- 
ducts of  the  vegetable  kingdom,  in  containing  no  hydrogen,  as  I  demonstrated  (in  my 
paper  upon  the  ultimate  analysis  of  organic  bodies,  published  in  the  Phil.  Trans,  for  1822), 
by  its  giving  out  no  muriatic  acid  gas,  when  heated  in  a  glass  tube  with  calomel  or  cor- 
rosive sublimate. 

Oxalic  acid  is  employed  chiefly  for  certain  styles  of  discharge  in  calico-printing  (which 
tee),  and  for  whitening  the  leather  of  boot-tops.  Oxalate  of  ammonia  is  an  excellent  re- 
agent for  detecting  lime  and  its  salts  in  any  solution.  The  acid  itself,  or  the  bi-oxalate 
of  potash,  is  often  used  for  removing  ink  or  iron-mould  stains  from  linen. 

A  convenient  plan  of  testing  the  value  of  peroxyde  of  manganese  for  bleachers,  &-c., 
originally  proposed  by  Berthier,  has  been  since  simplified  by  Dr.  Thomson,  as  follows. 
In  a  poised  Florence  flask  weigh  600  grains  of  water,  and  75  grains  of  crystallized  oxalic 
acid  ;  add  50  grains  of  the  manganese,  and  as  quickly  as  possible  afterwards  from  150 
to  200  grains  of  concentrated  sulphuric  acid.  Cover  the  mouth  of  the  flask  with  paper, 
and  leave  it  at  rest  for  24  hours.  The  loss  of  weight  it  has  now  suffered  corresponds 
exactly  to  the  weight  of  peroxide  of  manganese  present ;  because  the  quantity  of  car- 
bonic acid  producible  by  the  reaction  of  the  oxalic  acid  with  the  peroxide  is  precisely 
equal  to  the  weight  of  the  peroxide,  as  the  doctrine  of  chemical  equivalents  shows. 

By  exposing  100  parts  by  weight  of  dry  sugar  to  the  action  of  825  parts  of  hot  nitric 
acid  of  1-38  specific  gravity,  evaporating  the  solution  down  to  one-sixth  of  its  bulk, 
and  setting  it  aside  to  crystallize,  from  58  to  60  parts  of  beautiful  crystals  of  oxalic 
acid  may  be  obtained,  according  to  Schlesinger. 

Oxalic  acid  may  be  produced  by  the  action  of  nitric  acid  upon  most  vegetable  sub- 
stances, and  especially  from  those  which  contain  no  nitrogen,  such  as  well  washed  saw- 
dust, starch,  gum,  and  sugar.  The  latter  is  the  article  generally  employed,  and  possesses 
many  advantages  over  every  other  material.  Treacle,  which  is  a  modification  of  sugar, 
also  comes  within  the  same  ranges.  A  very  contemptible  spirit  of  exaggeration  prtw 
vails  in  respect  to  the  amount  of  produce  attainable  by  oxalic  acid  makers  from  a  given 
weight  of  sugar.  The  generality  of  the  statements  is  absurdly  false.  One  cwt.  of  good 
treacle  will  yield  about  116  lbs.  of  marketable  oxalic  acid,  and  the  same  weight  of  good 
brown  sugar  may  be  calculated  to  produce  about  140  lbs.  of  acid.  As  a  general  rule, 
5  cwts.  of  saltpetre,  or  an  equivalent  of  nitrate  of  soda,  with  2^^  cwts.  of  sulphuric  acid, 
will  generate  suflieient  nitric  acid  to  decompose  1  cwt.  of  good  sugar,  and  yield,  as  above, 
140  lbs.  of  fair  marketable  oxalic  acid,  free  from  superfluous  moisture.  Any  hope  of 
improvement  seems  directed  rather  to  an  economy  of  nitric  acid,  than  to  an  increased 
production  of  oxalic  acid  from  a  given  weight  of  sugar.  Tlie  process  is  carried  on 
either  in  large  wooden  vessels,  or  in  small  earthenware  jars  disposed  in  a  water-bath, 
each  jar  having  a  capacity  of  about  a  gallon  or  less ;  the  specific  gravity  of  the  nitric 
acid  need  not  be  so  high  when  operating  on  the  large  scale,  in  a  wooden  trough,  as 
when  employing  the  earthenware  jars.  From  1-200  to  1-270  is  the  range ;  and  the  tem- 
perature m  neither  case  should  much  exceed  or  fall  short  of  125°  Fahr.  The  favourable 
symptoms  are  a  regular  and  tolerably  active  evolution  of  gas  without  the  appearance 
of  red  fumes,  and  a  peculiar  odour  which  only  faintly  recals  the  smell  of  nitric  oxide. 
Tlie  gases  evolved  consist,  nevertheless,  of  nitric  oxide  and  carbonic  acid,  but  the  influ- 
ence of  this  latter  gas  has  a  remarkable  effect  in  arresting  the  aflftnity  of  the  nitric  oxide 
for  oxygen.  So  long  as  the  carbonic  acid  is  present,  the  mixture  may  be  mingled  with 
its  own  bulk  of  oxygen  gas,  without  any  diminution  of  volume,  for  several  minutes,  or 
the  production  of  red  fume ;  but  the  moment  a  little  ammonia  vapour  is  applied,  so  at 


n 


312 


OXALIC  ACID. 


to  condense  the  carbonic  acid,  the  whole  becomes  of  a  deep  orange  hue.  Herein  Iie« 
a  difficulty  connected  with  the  re-conversion  of  the  nitric  oxide  into  nitric  acid  by  th« 
action  of  atmospheric  oxygen  ;  and  for  the  same  reason,  the  employment  of  these  gases 
in  the  manufacture  of  sulphuric  acid  has  not  answered  the  expectations  of  those  who 
have  tried  the  experiment  practically.  Carbonic  acid  would  appear  to  possess,  not  sim- 
ply a  neutral  agency  in  obstructing  oxidation,  but  a  negative  power  of  preventing  it 
How  far  blowing  atmospheric  air  through  the  acidulous  saccharine  solution,  during  the 
process  of  oxalic  acid  making,  might  tend  to  economize  the  consumption  of  nitric  acid, 
we  cannot  pretend  to  say  ;  but  as  the  nitric  acid  really  forms  the  chief  item  of  expense,  it 
is  by  such  expedients  that  a  saving  may  possibly  be  effected.  When  sti-ong  nitric  acid 
is  boiled  upon  sugar,  in  the  way  recommended  in  mamy  chemical  works,  for  the  produc- 
tion of  oxalic  acid,  a  great  loss  of  all  the  materials  ensues;  and  most  of  the  oxalic  acid 
being  peroxidized  passes  off  as  carbonic  acid,  leaving  scarcely  as  much  acid  behind 
as  is  equivalent  to  half  the  weight  of  the  siigar  employed.  This  accounts  for  the  dis- 
crepancies which  have  been  published  in  this  branch  of  manufacture. 

Almost  tlie  only  commercial  article  made  from  oxalic  acid  is  the  binoxalate  of  potash 
or  salt  of  sorrel.  This  substance  results  from  the  decomposition  of  carbonate  of  potash 
by  an  excess  of  oxalic  acid.  The  carbonate  of  potash  is  first  dissolved  in  hot  water, 
and  the  oxalic  acid  added  until  the  effervescence  ceases ;  after  which  a  similar  quantity 
of  oxalic  acid  to  that  previously  employed  is  thrown  in,  and  the  solution  is  boiled 
for  a  few  minutes;  and  then  it  is  set  aside  to  crystallize.  The  crystals,  after  being 
drained  and  dried,  are  fit  for  the  market  j 

Manufacture  of  Oxalic  Acid  Oxalic  acid  is  formed  by  the  action  of  nitric  acid  <mfa 
great  number  of  vegetable  substances,  such  as  sugar,  rice,  starch,  washed  sawdust,  Ac 

Sugar,  either  in  its  crystalline  state,  or  in  that  of  molasses  or  treacle,  is  the  sub- 
stance more  commonly  employed  in  the  manufacture  of  oxalic  acid. 

On  the  addition  of  nitric  acid  to  the  saccharine  solution  and  exposure  to  heat,  a  sub- 
stitution of  part  of  the  oxygen  of  the  nitric  acid  for  the  hydrogen  of  the  sugar  is 
eflFected,  oxalic  acid  being  formed,  and  binoxide  of  nitrogen  evolved  from  the  liquor. 
Other  changes  than  this,  however,  take  place :  carbonic  acid  is  often  disengaged  with 
the  binoxide  of  nitrogen,  and  saccliaric  acid  and  other  products  remain  in  solution 
with  the  oxalic  acid. 

Instead  of  cane  sugar  or  treacle,  the  saccharine  substance  formed  by  the  action  of 
sulphuric  acid  on  potato  or  other  starch  (as  in  Mr.  Nyren's  process)  is  employed.  For 
this  purpose  the  potatoes  are  well  washed,  and  then  reduced  into  a  fine  pulp  by  rasp- 
ing, grinding,  or  other  suitable  means;  such  pulp  is  then  washed  two  or  three  times, 
by  placing  it  in  water  and  well  stirring  it  therein,  then  permitting  the  pulp  to  subside, 
and  running  off  the  water.  The  pulp  thus  obtained  is  next  placed  in  an  open  vessel 
of  lead,  or  wood  lined  with  lead,  with  as  much  water  as  will  allow  of  the  mixture 
being  boiled  freely,  by  means  of  steam  passed  through  leaden  pipes  placed  therein. 
Into  the  mixture  of  pulp  and  water,  about  2  per  cent  by  weight  (of  the  j)otatoes  em- 
ployed) of  sulphuric  acid  is  to  be  stirred  in,  which  will  be  at  the  rate  of  from  8  to  10 
per  cent  of  acid  on  the  quantity  of  farina  contained  in  the  potatoes ;  the  whole  is  now 
to  be  boiled  for  some  hours,  until  the  pulp  of  the. potatoes  is  converted  into  saccharine 
matter,  the  completion  of  this  process  being  readily  ascertained  by  applying  a  drop  of 
tincture  of  iodine  to  a  small  quantity  of  boiling  liquor  placed  on  the  surface  of  a  piece  of 
glass,  when,*if  there  be  any  farina  remaining  unconverted,  a  purple  colour  will  be  pro- 
duced. The  saccharine  product  thus  obtained  is  then  filtered  through  a  horse-hair  cloth, 
after  which  it  is  carefully  evaporated  in  any  convenient  vessel,  until  a  gallon  of  it  weighs 
about  14  or  l^  lbs. ;  it  is  now  in  a  proper  condition  to  be  employed  in  the  manuSic- 
ture  of  oxalic  acid,  by  the  application  of  nitric  acid,  as  in  the  case  of  operating  from 
sugar  or  treacle.  Horse-chesnuts,  deprived  of  their  outer  shells,  are  also  applicable  to 
the  manufacture  of  oxalic  acid,  when  treated  in  the  way  above  described  for  putatoeat 

Instead  of  operating  with  sulphuric  acid,  the  farina  of  potatoes  and  of  chosnuts  may 
be  treated  with  diastase,  and  converted  into  a  liquor  similar  to  that  obtained  after 
evaporation  from  the  farina  and  sulphuric  acid  before  mentioned,  using  about  the  same 
proportion  of  diastase  as  before  directed  for  sulphuric  acid.  In  this  case  the  liquor  is 
made  of  the  required  strength  at  once,  and  the  processes  of  filtration  and  evaporation 
are  rendered  unnecessary. 

The  apparatus  required  in  the  conversion  of  the  saccharine  matter  (whether  of  cane 
sugar  or  formed  of  starch  in  the  way  above  mentioned)  into  oxalic  acid  is  very  simple. 
Usually  earthenware  jars  of  about  2  gallons'  capacity  are  employed,  whicii,  when 
charged  with  nitric  acid  and  the  saccharine  material  used,  are  placed  in  water-baths 
capable  of  holding  a  hundred  or  more  of  these  jars.  These  baths  are  constructed  of 
bnck  and  lined  with  lead,  and  are  heated  by  means  of  steam  passed  through  coils  of 
lead  pipe  placed  therein. 
Instead  of  earthenware  jars,  vessels  of  lead,  or  of  wood  lined  with  lead,  may  be  em- 

\ 


\K 


•!^^ 


OXALIC  ACID. 


313 


ployed  in  the  manufacture  of  oxalic  acid.  For  this  purpose  square  open  vessels,  8  ft 
square  and  3  ft  deep,  are  a  convenient  size,  the  liquor  being  heated  by  means  Of  steam 
passed  through  a  coil  of  lead  pipe.  A  coil  of  about  48  ft  of  one-inch  pipe  in  a  vessel 
of  the  size  above  mentioned,  is  sufficient  to  keep  the  liquor  at  the  required  temperature. 
In  using  these  vessels,  the  liquor  [whatever  it  may  be]  to  be  converted  into  oxalic  acid 
is  put  into  them  together  with  the  acid  employed,  and  heated  until  the  required  decom- 
position is  effected.  The  liquor  is  then  drawn  off  by  a  sj'phon,  or  by  a  cock  placed  at 
the  bottom  of  the  vessel,  into  shallow  leaden  vessels,  or  wooden  vessels  lined  with  lead, 
to  cool  and  crystallize,  and  the  mother  waters  are  drawn  off  from  the  crystals,  and 
used  in  the  next  operation. 

When  the  manufacture  of  this  acid  is  conducted  in  large  vessels,  as  above  mentioned, 
the  specific  gravity  of  the  nitric  acid  may  be  less  than  when  the  earthenware  jars  are 
used.  P>om  1'200  to  1-270  are  about  the  limits  of  the  range  allowed  for  the  gravity 
of  the  acid.  As  regards  the  temperatures  of  the  baths,  this  should  be  maintained  at 
or  about  126°  Fahr.  Whilst  the  operation  is  in  progress,  the  active  evolution  of  gas, 
without  the  appearance  of  red  fumes,  and  the  emission  of  a  peculiar  smell,  slightly 
indicative  of  the  presence  of  nitric  oxide,  are  amongst  the  signs  that  every  thing  is  in 
good  working  condition.  The  judicious  addition  of  sulphuric  acid  is  found  to  contri- 
bute to  an  increase  of  the  quantity  of  oxalic  acid  produced.  The  product  of  acid  from 
a  given  quantity  of  sugar  has  been  much  undei'stated  by  chemical  writers:  this  has 
most  probably  arisen  from  the  circumstance  of  boiling  the  sugar  with  strong  nitric 
acid,  by  which  means  a  large  quantity  of  oxalic  acid  becomes  converted,  as  soon  as 
formed,  into  carbonic  acid,  and  the  result  is,  that  the  actual  product  of  oxalic  acid  ob- 
tained represents  only  about  one-half  of  the  sugar  employed,  and  therefore  not  above 
one-half  the  quantity  which  should  have  been  obtained.  Thus  we  find  it  stated,  that 
from  60  to  60  lbs.  of  oxalic  acid  are  obtainable  from  100  lbs.  of  good  sugar,  whereas  the 
quantity  actually  obtained  in  practice  is  from  1 26  to  130  lbs.  lYeacle  of  course  gives  a 
smaller  product;  100  lbs.  of  fair  quality  yielding  from  105  to  110  lbs.  of  oxalic  acid. 

The  mother  liquor  having  been  poured  off,  the  crystals  of  acid  obtained  are  thrown 
on  drainers  and  washed,  then  carefully  dried  in  a  suitable  stove.  The  mother  liquors, 
when  treated  with  a  fresh  supply  of  nitric  acid  and  treacle,  are  ready  for  a  further 
operation. 

About  4%  cwts.  of  nitrate  of  soda,  and  2^  cwts.  of  sulphuric  acid,  are  used  to  furnish 
the  nitric  acid  required  to  convert  1  cwt  of  good  sugar  into  oxalic  acid. 

Mr.  Jullion  has  patented  a  process  for  the  conversion  of  formic  acid  into  oxalic  acid. 
For  this  purpose,  formic  acid  is  saturated  with  a  solution  of  caustic  potash,  and  then 
half  the  quantity  of  caustic  potash  required  for  saturation  is  added  to  the  above 
mixture ;  the  whole  is  then  evaporated  to  dryness,  and  heated  to  560°  Fahr.  By  this 
process,  the  formic  acid  is  decomposed,  and  oxalate  of  potash  formed.  Caustic  soda 
may  also  be  employed  instead  of  caustic  potash. 

The  oxalate  of  potash  or  of  soda  thus  obtained  is  then  treated  with  sulphuret  of 
barium,  hydrate  of  baryta,  or  any  soluble  salt  of  baryta,  whereby  an  oxalate  of  baryta 
is  precipitated,  from  whence  pure  oxalic  acid  maj'  be  obtained  by  means  of  sulphuric 
acid. 

Another  mode  of  obtaining  oxalic  acid  is  by  the  process  patented  by  Dr.  Wilton 
Turner,  who  directs  the  uric  acid  obtained  from  guano  to  be  treated  with  peroxide  of 
lead  or  manganese  suspended  in  water,  at  a  boiling  temperature,  by  which  means  it  will 
be  decomposed  into  oxalic  acid,  allantoin,  urea.  The  oxalic  acid  forms  an  insoluble 
compound  with  the  lead  or  manganese.  The  lead  process  is  as  follows :  A  known 
w^ht  of  uric  acid  is  placed  in  an  open  cylindrical  iron  vessel,  capable  of  holding  two 
pounds  of  water  for  every  pound  of  the  acid,  and  adapted  to  boil  by  steam.  A  clear 
saturated  solution  of  lime  water  is  then  added,  and  as  soon  as  it  is  heated,  and  in  brisk 
ebullition,  the  peroxide  of  lead  is  added  in  successive  portions,  as  long  as  it  is  observed 
to  be  whitened  by  the  boiling  liquid.  The  whitish  powder  thus  obtained  is  oxalate  of 
lead.  About  240  lbs.  of  peroxide  of  lead  are  required  for  each  1 68  lbs.  of  uric  acid 
employed.  Tlie  supernatant  liquor  is  next  drawn  ofl^  and  the  oxalate  of  lead  washed 
with  clear  water;  this  is  then  boiled  with  dilute  muriatic  acid  [equal  parts  of  acid  and 
water],  by  means  of  which  oxalic  acid  is  obtained  in  solution,  which  is  evaporated  and 
crystallized,  whilst  muriate  of  lead  remains  as  the  precipitate. 

The  allantoin  is  also  decomposed  into  oxalic  acid  and  ammonia  by  boiling  it  with 
caustic  alkali.  The  former  unites  with  the  alkali  used,  while  the  ammonia  passes  over, 
and  may  be  collected  as  liquid  ammonia;  the  oxalic  acid  thus  generated  may  be 
obtainea  as  oxalate  of  potasli,  if  potash  be  the  alkali  employed,  or  as  oxalic  acid  if 
baryta  be  used,  by  decomposing  the  latter  oxalate  by  means  of  sulphuric  acid.  In  this 
case,  the  oxalate  of  baryta  may  be  treated  in  the  way  previously  described  for  oxalate 
of  lead.     This  process  is  delusive. 

As  regards  these  various  methods  for  obtaining  oxalic  acid,  their  employment  will 

Vol.  IL  2  S 


314 


OXALIC  ACID. 


of  course  always  be  a  question  of  £.  s.  d.,  the  economy  of  many  operations  of  manu 
facturiug  chemistry  being  often  dependent  upon  their  adaptation  to  the  requirement* 
or  purposes  of  particular  manufactures,  in  connection  with  other  branches  of  manufac- 
ture carried  on  by  them. 

The  low  price  at  which  treacle  and  sugar  are  now  obtainable  is  much  in  favour  of 
their  use  in  this  manufacture.  The  chief  point,  however,  to  which  attention  must  be 
directed,  in  order  to  lessen  the  cost  of  production  of  this  article,  is  in  economizing  the 
nitric  acid  used. 

In  speaking  of  the  action  of  nitric  acid  upon  sugar,  it  was  observed  that  carbonic 
acid  was  produced,  and  that  it  passes  oflf  with  the  deutoxide  of  nitrogen  also  set  at 
liberty.  The  presence  of  carbonic  acid,  in  this  case,  proves  a  great  obstacle  in  the 
reconversion  of  nitric  oxide  into  nitric  acid,  preventing  the  union  of  the  oxygen  of  the 
air  with  the  nitric  oxide.  Various  processes  have  been  from  time  to  time  suggested  to 
effect  this  economy  in  the  manufacture  of  oxalic  acid :  amongst  these,  the  following 
may  more  particularly  be  noticed : — 

In  1846,  Mr.  Jullion  patented  a  method  of  converting  the  ojrides  of  nitrogen  given 
off  in  the  manufacture  of  oxalic  acid,  into  nitrous  and  nitric  acids.  For  this  purpose, 
he  uses  a  "  generating  vessel,"  which  is  a  vessel  something  like  a  Woulfes'  bottle,  only 
having  a  moveable  top  fitting  air-tight,  and  capable  of  holding  about  100  gallons.  The 
materials  to  form  the  oxalic  acid  are  introduced,  and  the  vessel  heated  by  a  water-bath 
(by  steam  or  other  convenient  means^  which  surrounds  the  vessel ;  a  quantity  of  nitric 
acid  is  then  added,  and  air  or  oxygen  is  forced  in  through  a  pipe  inserted  in  the  top. 
The  oxygen,  coming  in  contact  with  the  evolved  oxides  of  nitrogen,  immediately  con- 
verts a  portion  into  nitrous  and  hyponitrous  acids,  which  are  partly  again  absorbed  by 
the  fluid  in  the  vessel ;  another  portion  passes  off  by  a  pipe  inserted  in  the  upper  part  of 
the  vessel,  which  pipe  passes  through  a  furnace.  This  part  in  the  furnace  is  a  little 
enlarged,  and  is  heated  from  600°  to  900°  Fahr. ;  this  part  of  the  pipe  or  tube  contains 
spongy  platinum,  or  other  similar  substances ;  the  gases,  in  coming  in  contact  with  the 
heated  platinum,  combine  to  form  nitric  acid,  which  is  afterwards  condensed  in  vessels 
arranged  as  usual  in  the  manufacture  of  this  acid.  Instead  of  platinum  a  close  vessel 
containing  water  may  be  used,  which  decomposes  hyponitrous  and  nitrous  acids,  giving 
rise  to  nitric  acid.  This  principle  is  applied  in  the  following  ways :— -the  oxides  of 
nitrogen,  as  evolved  from  the  liquor  in  the  decomposing  vessel,  coming  in  contact  with 
oxygen,  are  converted  into  hyponitrous  and  nitrous  acids,  which,  upon  being  mingled 
■with  steam,  are  decomposed  into  nitric  acid  and  binoxide  of  nitrogen ;  or  the  intro- 
duction of  steam  may  be  obviated,  by  using  heated  air  or  oxygen  in  the  decomposing 
vessels,  by  which  means  moisture  will  be  furnished  from  the  liquor ;  the  amount  of 
evaporation  thus  caused  will  also  prevent  an  inconvenient  increase  of  the  mother-liquor. 
The  compounds  thus  formed,  when  passed  through  suitable  condensers,  will,  if  the 
supply  of  atmospheric  air  or  oxygen  has  been  in  excess,  be  all  or  nearly  all  condensed 

into  nitric  acid.  ,  .     , 

The  following  is  a  description  of  Crane  and  Jullion  s  continuous  method  of  manO' 
facturing  oxalic  acid  and  nitric  acid  at  one  process : — the  oxalic  acid  mother-liquor  of 
a  previous  process  is  placed  in  a  close  or  covered  vessel,  termed  a  "  generator,"  formed 
of  slate  ;  nitric  acid  and  syrup  in  the  usual  proportions  employed  for  such  quantity  of 
mother-iiquor  are  also  placed  separately  in  feeding  vessels,  over  the  "  generator;"  heat 
is  then  applied  to  the  mother-liquor,  and  the  temperature  raised  as  quickly  as  possible 
to  180°  or  200°  Fahr,  Streams  of  nitric  acid  and  symp  are  then  caused  to  flow  into 
the  generator  by  means  of  suitable  stop-cocks  and  funnel-pipes,  in  such  a  quantity  that 
the  delivery  of  the  whole  shall  occupy  about  18  houi-s,  at  the  expiration  of  which  time 
the  process  will  be  completed. 

The  gases  arising  from  the  decomposition  of  the  materials  so  supplied  pass  off 
through  an  eduction  pipe  in  the  top  of  the  generator,  into  a  receiver,  into  which  a  stream 
of  chlorine  is  introduced  (from  a  chlorine  generator)  sufficient  to  convert  the  whole  of 
the  oxides  of  nitrogen  into  nitric  acid.  A  portion  of  water  in  the  receiver  is  decom- 
posed, its  oxygen  combining  with  the  oxide  of  nitrogen  to  form  nitric  acid,  whilst  ita 
hydrogen  combines  with  the  chlorine  to  form  hydrochloric  acid.  These  mixed  vapours 
pass  over  into  suitable  condensing  vessels  placed  to  receive  thenu  The  whole  of  the 
nitric  acid  and  syrup  having  been  run  in,  and  the  liberation  of  the  gases  or  oxides  of 
nitrogen  having  ceased,  the  oxalic  acid  liquor  is  drawn  off  from  the  generator  and 
crystallized. 

Messrs.  M'Dougall  and  Rawson  have  patented  a  method  of  recovering  the  vapours 
which  pass  off  in  the  manufacture  of  oxalic  acid.  To  effect  this,  they  direct  the 
employment  of  a  series  of  vessels  containing  water,  into  the  first  of  which  the  nitrous 
gas  or  fames  are  passed,  through  a  tube  dipping  below  the  surface  of  the  vessel ;  air  is 
also  admitted,  which  mixes  with  the  gas  bubbling  up  through  the  water.  Attached  to 
the  last  vessel  of  the  series  is  a  pneumatic  apparatus,  by  means  of  which  the  mixture  of 


., 


OXALIC  ACID. 


815 


nitrous  gas  and  air  are  drawn  through  this  series  of  v^e^  eac^  ^-^^J^cf  i'  wul'tJS; 
Ig  "tf  The  liquid,  and  another  tube  or  pipe  ^^-^^^^^  l^^L  and  water,  becomes 

d^tTf in^^:!^^^^^^^  --^-  -  -'' ''  "'^ 

^rnT^  O.being  P-d  in^  wat.  of J.^  t^^^^^^^^ 

2  N  05  +  N  O,  result,  the  2  ^  ^^l^^^J^^t^^^i^^^^  liquid,  and  unites  with 
the  N  0»  which  is  an  mcondensable  gas,  ^"f^^^^^^^^  ^akes  two  atoms  of  oxygen 
the  air  in  the  vessel  above  the  Hl"^  ^^^J™J"th^^^^^^^  liquid  becomes  nitric  acid 

from  the  air,  and  becomes  ^  O.  whic^^P^^^^^^^^^  ,,,,  Citrous  fumes  or  gas  are 

and  nitrous  gas,  as  before,  and  tbus  neany  tuc 

reconverted  into  nitric  ^cid.  recovering  the  nitric  acid,  he  fills  his  regenerating 

In  Ecarnot's  patented  process^^^^^^^^  1  i^^  the  oxygen  by 

vessels  with  a  porous  substance,  ^^\"  ",   ^     y^^  from  a  boiler. 

blowing  machine,  a  flow  oV'XJri^cid-Arno^^^^  account  of  the  decompos.- 

Rationale  of  the  Process  for  f^f'*^^^ f^^^.f '  "id  has  vet  been  published,  that  1  am 

tion  which  ensues  in  the  °^^'?^^^1"^^,;\S^^^^^  kw  att/ntion  to  this  subject 

aware  oC  the  following  experiments  may  tend  pernap^  ^^^^^  .^  ^  water-bath, 

The  apparatus  employed  co°«^«;^ed  of  a  ^j/J^^i^jehk  t«be  passed  into  a  two- 
and  luted  to  a  tubulated  receiver  from  ^^^  «P^^\"^j^\P^  ^^^^le  was  connected  by  a  tube 
necked  bottle  containing  a  ^ol^^^^^^^^^^^Xfuing  a  slti^  of  nitrate  of  lime,  from 

;i:!:hTn^^rtU'e^  ;zt^^^^^^'  -^  ^--^^  ^^^  --'-  -'  ^^ 
^TeXta^rof  ^^r\:-r^i^  r^oirntfta?^"id 

Fahr.  for  forty-eight  hours  in  each  experiment  ^^^^  J^^^^  ^j^^^d  to  effloresce  in  » 
r^Z^  rto^Smrr:^:^  J^t^r^^  were  then  dissolved,  re- 

and  nitrate  of  lime  after  each  eYerirnen^:alb^^^^^^^^^  ^  ,, 

four-and-twenty  hours,  after  Y^^?^*?. '\^*^T!1  nothing  m  weight  by  prolonged  ex- 
employed  was  tlie  best  refined  white  and  ^^^^^^^^^^  J^  of 'specific  gravity 
Dosure  to  a  temperature  of  212  .  The  ^""^.  ^^''^^  "I^.^.!-^  'f  i^  weight  of  dry  acid, 
?  245  at  60-;  it  contained  as  nearly  as  P«««;^.^^\nJ^^^Xcr^^^^  The 
as  was  proved  by  the  amount  of  pure  ^^^^^^/^^^^  P^^X  sl^^^^^^  the  amount  of  sugar 
followin"^  table  e'xhibits  the  results  of  ei^^^^^^                                       ^^^^^^.^  ^,,^^  ^^ 

added  to  the  one  following.         ______ 


Number. 


1. 
2. 
8. 
4. 
6. 
6. 
7. 
8. 


Employed. 


Sugar  in  Ounces. 


28 
28 
28 
28 
28 
28 
28 
28 


Dil. 


Nitric  Acid  in 
Ounces. 

184 

184 

184 

184 

184 

184 

184 

184 


Obtained. 


Oxalic  Acid  in 
Ounces. 


32i 

30 

29i 

31i 

30i 

30i 

31 


Carbonic  Acid  in 
Ounces. 

"20f 
22i 
21 
21i 
22 
21 
2H 
2H 


tote  ogta?ned,  as;these  may  ^^^e^hTr  we  sha7  h^v^^^^^^^^  of  the  seven  fol- 

then  we  omit  that  experiment  ^^^^g^^^f,^' ^.^^^.T  J^ted  nitric  acid  have  produced 
lowing,  showing  that  196  of  sugar  and  1288  ot  miutea  m  .      ^^  ^^i.^^  ^ 

2m  of  oxalic  acid,  and  150i  of  carbonic  aad,  and  ^^ j\  ^^  P^^^id,  and  that  by 
the  oxalic  acid  obtained  almost  exactly  equals  that  ^J;,f  ^f  [^^""^arbon  of  any  givea 
the  Sn  of  nitric  acid  in  the  way  ^escribed  one  half  of  the  carD    ^^^^J^^^^-^ 

quantity  of  sugar  is  converted  jf  ^.^^X'^LcTd  of  va  deities  and  at  yarioua 

Turf ^rioVL^i:  1^^^^^^^^^      ^-'-'"^  -^^^'  ^^ 

2  S  ' 


7. 


316 


OXALIC  ACID. 


fw^  -^  T'T  ^f,°»»*^a%  diminishes  the  produce  of  oxalic  acid.  Fro» 
these  experiments  it  would  appear  that  no  more  than  124  lbs.  of  oxalic  acid  can  be  ob- 
tamed  from  1  cwt  of  sugar.     This  I  am  aware  is  much  below  theCantTtvSnerallv 

?X"^f  ''.i?'  P'?^T^  ^"  ^^'  ^^^^^  .««*^^'  «^^  ^»^^«^  i«  etIteS  to^ vary  ftorm^ 
140  lbs.  for  the  cwt  of  sugar;  such  acid  is,  however,  contaminated  w^Ih  Xic  acS 
and  mother  liquor  and  is  moreover  decidedly  damp,  as  shown  by  the  mZ^e?  in  whi'ch 
the  crystals  cling  to  the  sides  of  the  bottle  in  which  they  are  contained  some  Xw 
•nee  must  aho  be  made  for  the  tendency  to  exaggeration  which  prevails'in  o™r  manu- 
factcries.  These  proportions  do  notgreatly  differ  from  those  employed  in  practice  bv 
oxalic  acid  makers  when  allowance  is  made  for  the  loss  of  nitric  SinddenUl  t^ 
Soyed :-       '"*^"^^^^^«-     ^he  following  is  the  general  proportion  of  matlrial^e^ 

Sugar               -            .                        .           ,  1 1 o  IK 

Nitrate  of  potash        -            -           .            .            I  '        Jaa  ik!" 

Sulphuric  acid "         280  IK 

ol'^-en^^'^  ^  ^"'"'^"''^  ^^^  ^^^  ""^  '''^"^  ^""'^  *°^  ^^^  ^^«-  ""^  «"^P^^  of  potash 
Experiment  has  proved  to  me  that  the  first  change  produced  is  to  convert  the  can« 
Wgar  into  grape  sugar;  and  as  the  first  portions  of  gas  evolved  consist  almost  entirtTy 
rLd  .r^'  ""'^^  little  or  no  carbonic  acid,  it  is  dear  that  some  compound  is  genZ 
rated  in  the  commencement  of  this  process,  which  contains  the  elements  of  sugar  united 
to  an  excess  of  oxygen:  the  following  diagram  must  therefore  be  looked  on^as  merely 
explanatory  of  the  ultimate  change.  "icieijr 

UrS!!!;'^  *Vr'^  ^  *™  '''''^  that  !n  some  hundreds  of  attempts  conducted  on  a  pretty 
large  scale,  I  have  never  once  exceeded  the  amount  here  stated  (124  lbs.)  when  tS 
acid  was  properly  purified  and  freed  from  adhering  moisture.  The  folio wtng  dagram^ 
m  my  opinion,  represents  the  nature  of  the  ultimate  decomposition  which^ensu^es^ 
^L^;:-^^^^^  ^"^^^^-  -  unquestionaW  produced  in^ TeliS 

Atoms. 

-4' 


Materials  employed. 


Common  sugar, 
atom   - 


Nitric  acid,  Y 
atoms 


Carbon  - 
Hydrogen 
,  Oxygen 
Nitrogen 
Oxygen 


-    11 


Products. 
6  Carbonic  acid. 


Water. 


7  Deutoxide  of  Nitrogen. 

nYTnTTTrkUTTM?  rku  n:^*T%       *      ,.        ."  3  Crystallized  oxalic  acid. 

UAILHLOKIDE  OF  LEAD.  A  white  pigment  patented  by  Mr.  Hugh  Lee  Pattin- 
8on  of  Newcastle,  which  he  prepares  by  precipitating  a  solution  of  chloride  of  lead  in 
not  water  with  pure  lime  water,  in  equal  measures;  the  mixture  being  made  with 
agitation.  As  the  operation  of  mixing  the  lime  water,  and  the  solution  of  chloride  of 
lead,  requires  to  be  performed  in  an  instantaneous  niaaner,  the  patentee  prefers  to  em- 
ploy for  this  purpose  two  tumbling  boxes  of  about  16  feet  cubic  capaoitv  which  are 
charged  with  the  two  liquids,  and  simultaneously  upset  into  a  cistern  in  which  oxi- 
chlonde  of  lead  is  mstantaneously  formed,  and  from  which  the  mixture  flows  into  other 
cisterns,  where  the  oxichloride  subsides.     This  white  pigment  consists  of  one  atom  of 

nvmSa         *"    ^"^  ^^^  ^^^^^  ^^  ^^*^'  "^'^^  ""^  without  an  atom  of  water 
nYfii^fi*'"®  neutral  compounds,  containing  oxygen  in  equivalent  proportion, 
f J;i  /»         '  ^'^  salt  J  consisting  of  oxigenated  acids  and  oxides,  to  distinguish  them 
from  the  haloseij  which  are  salts  consisting  of  one  of  the  archa^al  elemente :  such  a« 
chlorine,  lodme,  bromine,  <fec.,  combined  with  metals.     See  Salt 

fnr^^l^^^^^T'^'^'-J  ^r'^1^^^'  ^^^™-)'  '^"  ^^  examined  only  in  the  gaseous 
form,  and  is  most  conveniently  obtained  pure  by  exposing  chlorate  of  potash,  or  red 
oxide  of  mercury,  m  a  glass  retort,  to  the  heat  of  a  spirit  lamp  ;  loo  grains  of  the  salt 

^hnf /linn"''',  '"'^''f  ^"f  ^"^  P"^'?^  ^^  "i'^^'  ^^^''^ '-  --  iron^retort,  gives  out 
about  1200  cubic  inches  of  oxygen,  mixed  with  a  little  nitrogen.     The  peFoxide  of 

manganese  alone,  or  mixed  with  a  little  chlorate  of  potash,  also  affords  it^  either  by 
Ignition  alone  in  an  iron  or  earthen  retort,  or  by  a  lamp  heat  in  a  glass  retort,  wheJ 
mxed  with  sulphuric  acid  Oxygen  is  void  of  taste,  colour,  and  smell.  It  possesses 
all  the  mechanical  properties  of  the  atmosphere.  Its  specific  gravity  is  11026  com- 
pared to  air  rOOOO ;  whence  100  cubic  inches  of  it  weigh  33-85  |rains.*^  Combustibles, 
even  iron  and  diamonds,  once  kindled,  burn  in  it  most  splendidly.  It  forms  21  parte 
in  100  by  volume  of  air,  being  the  constituent  essential  to  the  atmospheric  functions 
of  supporting  ammal  and  vegetable  life,  as  well  as  flame.     3  parts  of  bichromate  of 


v^ 


OXYGEN. 


817 


potash  in  powder,  with  4  parts  of  oil  of  vitriol,  when  heated,  afford  oxygen  gas 

^^The^fulT'development  of  this  subject  in  its  multifarious  relations  will  be  discussed  in 

mv  forthcoming  new  system  of  chemistry.      ■  .  .     „        .         v„  *i.« 

OxYGEVATED-MuRiATic,  and  OxYMURiATic,  are  the  names  originally  given   by  tno 

French  chemists,  from  false  theoretical  notions,  to  chlorine,  which  Sir  H.  Davy  proved 

to  be  an  undecomposed  substance.  ,        ^    -nrx.  ^i„ 

Oxygen  in  the  atmosphere,  method  of  determimng  the  amount  thereof.  When  some  solu- 
tion of  caustic  potash  is  conveyed  into  a  tube  filled  with  mercury,  and  then  a  solution  of 
pyroKallic  acid,  the  liquids  mix  without  any  alteration;  but  it  now  a  bubble  of  oxv- 
ain  or  of  air  be  passed  into  the  tube,  the  liquid  acquires  a  blackish  red  or  nearly 
black  colour,  and  the  oxygen  is  as  rapidly  absorbed  as  carbonic  acid  by  caustic  potash. 
The  quantity  of  oxygen  which  is  absorbed  under  these  circumstances  by  1  pa^  by 
weight  of  pyrogalhc  acid  is  enormous.  According  to  the  experiinents  of  Doberemer 
1  gramme  of  pyrogallic  acid  in  an  ammoniacal  solution  absorbs  0-38  gramme  or  260 
cub.  centim.  of  oxfgen  ;  this  is  more  than  the  quantity  absorbed  by  1  part  m  weight  of 
sodium  on  its  conversion  into  oxide,  which  only  amounts  to  236  cub.  centim.  In  one 
experiment,  which  was  made  with  especial  care,  a  solution  of  1  gramme  pyrogallio 
acid  in  caustic  potash  (K  O,  Aq),  in  order  to  pass  into  neutral  carbonate  absorbs  at 
82-  F  192  cub.  centim.  carbonic  acid,  the  absorbent  capability  of  pyrogalhc  acid  for 
oxygen,  it  will  be  seen,  is  not  less  than  that  of  potash  for  carbomc  acid  The  follow- 
ing  resilts,  which  were  obtained  with  atmospheric  air,  wiU  give  an  idea  of  the  accuracy 
which  is  obtained  by  this  method : 


Number. 


Volume  of  Air  after  Intro- 
duction of  the  Caustic  Pot- 
ash. 


Decrease  in  Volume  after 
Introduction  of  Pyrogallic 
Acid. 


1. 

ft. 

s. 

«. 

%. 

7. 
8. 
9. 

10. 
11. 


221-5 
201-0 
193-0 
210-0 
204-5 
195*0 
200-0 
200-0 
200-0 
236-0 
258-0 


46-5 
42  0 
40-6 
440 
42-5 
40-8 
41-8 
41-6 
41-5 
49-0 
54-0 


Per  cent,  in  Volume  of 
Oxygen. 


20-99 
20-89 
21-03 
20-96 
20-7 1 
20-92 
20-90 
20-80 
20-'75 
20-76 
20-93 


With  the  expired  air  of  different  persons  the  following  results  were  obtained,  some 
with  gallic,  others  with  pyrogallic  acid :— 


No 


L 

IL 

IIL 

IV. 


Air. 


220-0 
221-5 
200-0 
194-0 


Decrease  in  Volume 
by  Solution  of  Pot- 
ash. 


9-0 

9-0 

110 

10-0 


Decrease  in  Volnme 
by  Gallic  or  Pyro- 
gallic Acid. 


86-0 
86-0 
800 
29-0 


Volume  of  Nitrogen. 


175-0 
175-6 
158-2 
155-0 


IV. 

6-41 
14-95 
79-90 


Onsequently,  the  corresponding  air  in  the  experiments  contains : — 

I.  II.  III. 

Carbonic  acid      -        -        -    4-09  4-06  5-6 

Oxvffcn        .        -        -        -  16-36  1684  16-0 

Nitrogen      -        -        -        - '79-55  79-28  79-1 

These  analyses  have  only  been  made  to  test  the  method,  and  have  no  value  in  a 

physiological  point  of  view.  ;,.       •    *u      v  ^-       a        ^  tk^ 

The  following  was  the  mode  of  proceeding  in  the  above  mentioned  analyses: — Ine 
air  in  which  the  amount  of  oxj'gen  and  carbonic  acid  was  to  be  determined,  was  measured 
in  graduated  tubes  over  mercury.  The  tubes  would  contain  about  30  cubic  centim., 
eaSi  cubic  centim  divided  into  5  parts ;  they  were  filled  |  with  the  air,  the  quantity 
reftd  off  and  now  i  to  i  of  its  volume  of  solution  of  potash  of  1-4  sp.  gr.  (one  part  dry 


i 


di8 


PACO. 


hydrate  of  potash  to  two  parts  water),  introduced  by  means  of  the  common  pipette  with 
curved  point:  by  quickly  moving  up  and  <lown  the  tubes  in  the  mercury,  the  solution 
of  potash  is  spread  over  the  whole  inner  surface  of  the  tubes ;  and  when  no  further 
decrease  of  space  is  perceptible,  the  decrease  of  volume  is  read  off. 

When  the  air  has  been  previously  dried  by  means  of  chloride  of  calcium,  the  decrease 
in  volume  accurately  furnishes  the  amount  of  carbonic  acid  in  the  air;  but  if  it  were 
moist,  the  determination  has  an  error  attached  to  it,  which  is  owing  to  the  absorption 
of  the  aqueous  vapour  by  the  strong  solution  of  potash. 

After  the  carbonic  acid  has  been  determined,  a  solution  of  pyrogallic  acid,  containing 
one  gramme  of  acid  in  5  to  6  cub.  centim.  water,  is  introduced  by  means  of  a  second 
pipette  into  the  same  tube,  and  amounting  to  about  half  the  volume  of  the  solution  of 
potash.  The  same  plan  is  adopted  as  in  the  determination  of  the  carbonic  acid,  that  ia 
to  say,  the  mixed  liquids  are  well  shaken  over  the  inner  surface  of  the  tube,  and  when 
no  further  absorption  is  perceptible,  the  amount  of  nitrogen  is  measured  off. 

By  mixing  the  solution  of  pyrogallic  acid  with  the  potash,  the  latter  is  diluted,  and 
an  error  arises  from  the  diminution  of  its  tension ;  but  this  appears  to  be  so  exceedingly 
email,  that  it  is  not  determinable ;  at  the  same  time,  it  may  easily  be  avoided,  if;  after 
the  absorption  of  the  oxygen,  a  piece  of  solid  hydrate  of  potash,  corresponding  to  the 
amount  of  water  in  the  solution  of  pyrogallic  acid,  is  introduced,  and  its  solution  awaited. 

Ordinary  gallic  acid  may  be  employed  instead  of  the  pyrogallic  acid  with  the  same 
result ;  but  its  employment  has  this  mconvenience,  that  the  absorption  of  the  oxygen 
requires  a  much  longer  time,  at  least  H  to  2  hours,  instead  of  as  many  minutes. 
Owing  to  the  sparing  solubility  of  gallic  acid  in  water,  it  must  be  previously  converted 
into  gallate  of  potash,  a  cold  saturated  solution  of  which  is  employed.  When  this 
liquid  is  neutral,  or  contains  a  very  slight  excess  of  acid,  it  does  not  experience  any 
alteration  in  the  air.  Its  property  of  absorbing  oxygen  only  becomes  active  in  the 
presence  of  an  excess  of  alkalL 

When  the  gallic  acid  has  been  mixed  with  the  caustic  potash  in  the  tube,  the  liquid  on 
coming  into  contact  with  air  containing  oxygen,  assumes  a  dark  red  colour ;  thin  layers 
acquire  almost  a  blood-red  colour,  which  after  a  time  passes  into  brown.  By  the  pro- 
duction of  this  blood-red  colour  in  the  liquid,  which  moistens  the  sides  of  the  tube  on 
agitation,  the  progress  of  the  absorption  can  be  very  distinctly  traced ;  when  this  colour- 
ing is  no  longer  exhibited,  the  operation  is  complete.  With  respect  to  the  absorbent 
capacity  of  gallic  acid  for  ox^^gen,  it  is  known,  from  the  experiments  of  Chevreul,  that 
1  gramme  of  gallic  acid  dissolved  in  strong  potash  absorbs  290  cub.  centim.,  or  nearly 
0*417  gramme  oxygen.     In  this  respect  i*  is  in  nowise  inferior  to  pyrogallic  acid. 

Dr.  Stenhouse  has  described  a  most  excellent  method  for  preparing  pyrogallic  acid. 
He  obtained,  by  sublimation  from  the  dry  aqueous  extract  of  the  gall  nuts,  precisely 
in  the  same  manner  as  benzoic  acid  is  prepared  from  benzoin  resin,  above  10  per  cent, 
in  sublimed  acid  of  the  weight  of  the  extract  When  those  who  are  engaged  in  pho- 
tography have  become  convinced  that  in  many  cases  pyrogallic  acid  is  preferable  to 
gallic  acid,  the  increased  demand  for  this  acid  will  render  its  preparation  still  more 

productive.* 

The  principal  error  in  the  above  eudiometrical  process,  which  is  scarcely  to  be  got 
rid  o^  is  occasioned  by  the  difficulty  of  accuratel^r  reading  off  and  determining  the 
volume  of  the  air,  and  its  decrease  from  the  absorption  of  the  carbonic  acid  and  of  the 
oxygen,  owing  to  the  adhesion  of  the  liquid  to  the  sides  of  the  tubes.  This  error 
becomes  smaller  when  the  precaution  is  adopted  of  using  nearly  the  same  volume  of 
air  for  each  analysis ;  but  though  this  method  admits  of  perfectly  trustworthy  deter- 
minations in  comparative  analyses,  it  will  not  supersede  the  processes  of  MM.  Dumas 
and  Boussingault,  or  that  of  MM.  Regnault  and  Keisit,  or  that  of  M.  Bunsen  for  abso- 
lute determinations. 

It  need  scarcely  be  mentioned,  that  the  process  described  is  only  an  application  of 
the  beautiful  observations  made  by  Chevreul  and  Dobereiner  on  gallic  and  pyrogallic 
acids,  and  that  the  merit  of  the  discovery  belongs  to  these  illustrious  individuala. 

P. 

PACKFONG,  is  the  Chinese  name  of  the  alloy  called  white  copper,  or  German 

silver. 

PACO,  or  PACOS,  is  the  Peruvian  name  of  an  earthy-looking  ore,  which  con- 
sists of  brown  oxide  of  iron,  with  imperceptible  particles  of  native  silver  disseminated 
tlirough  it 

•  By  the  dry  distillation  of  so-called  Chinese  pall«,  in  small  retorts  capable  of  holdinjr  from  5  to  6  02. 
in  coarse  fragments,  a  very  concentrated  solution  of  pyrogallic  acid  is  obtained,  which,  evaporated  on 
the  water  ba^,  yields  of  brown  crystalline  pyrogallic  acid  nearly  15  per  cent,  of  the  weight  of  the  galls. 


PAINTS,  GRINDING  OP. 


319 


PADDING   MACHINE    (Machine    H    plaquer,  Fr.;    Klatsch,  or    Grundirmaschine^ 


Germ.),    in  calico-printing,  is  the    apparatus   for 
uniformly  with  any  mordant    In  ^g.  1024  a  b  c 


imbuing  a   piece   ol    cotton   cloth 

D  represents  in  section  a  cast  iron 

frame,     supporting     two     opposite 

standards  above  m,  in  whose  vertical 

slot  the  gudgeons  a  b,  of  two  copper 

or  bronze  cylinders  e  f,  run;   the 

gudgeons    of   e    turn    upon    fixed 

brasses  or  plummer  blocks ;  but  the 

superior  cylinder  f  rests  upon  the 

surface  of  the  under  one,  and  may 

be    pressed    down    upon    it    with 

V  greater  or  less  force  by  means  of 

|\\  the  weighted  lever  d  e  f  g,  whose 

centre  of  motion  is  at  d,  and  which 
bears  down  upon  the  axle  of  f. 
K  is  the  roller  upon  which  the  pieces 
of  cotton  cloth  intended  to  be  pad- 
ded are  wound ;  several  of  them 
being  stitched  endwise  together. 
They  receive  tension  from  the  ac- 
tion of  a  weighted  belt  o,  n,  which 
passes  round  a  pulley  n,  upon  the 
end  of  the  roller  k.  The  trough  g, 
which  contains  the  coloring  mat- 
ter or   mordant,  rests  beneath  the 

cylinder  upon  the  table  l,  or  other 

convenient  support.    About  two  inches  above  the  bottom  of  the  trough,  there  is  a 
copper  dip-roller  c,  under  which  the  cloth  passes,  ad er  going  round  the  guide  roller  m. 
Upon  escaping  from  the  trough,  it  is  drawn  over  the  half-round  stretcher-bar  at  i,  grooved 
obliquely  right  and  left,  as  shown  at  k,  whereby  it  acquires  a  diverging  exiensiot 
from  the  middle,  and  enters  with  a  smooth  surface  between  the  two  cylinders  e  r. 
These  arc  lapped  round  6  or  7  times  with  cotton  cloth,  to  soften  and  eqnahze  theii 
pressure.    The  piece  of  ^oods  glides  obliquely  upwards,  m  contact  with  one  third  of 
the  cylinder  f,  and  is  finally  wound  about  the  uppermost  roller  h.    The  gudgeon  of  h 
revolves  in  the  end  of  the  radius  h,  fe,  which  is  jointed  at  fc,  and  moveable  by  a  mortise  at « 
alon-  the  quadrantal  arc  towards  /,  as  the  roller  k  becomes  enlarged  by  the  convolutions 
of  the  web.    The  under  cylinder  e  receives  motion  by  a  pulley  or  rigger  upon  its  op- 
posite  end,  from  a  band  connected  with  the  driving-shaft  of  the  printshop.     To  ensure 
Urfect  eqiability  in  the  application  of  the  mordant,  the  goods  are  m  some  works  passed 
twice  through  the  trough ;  the  pressure  being  increased  the  second  time  by  slidmg  the 
weisrht  e  to  the  end  of  the  lever  df.  .  ....  , 

A  view  of  a  padding  machine  in  connexion  with  the  driving  mechanism  is  given  undo. 
Hot  Flue;  see  also  Starching  Machine. 

PAINT.     SeeRouGK.  .  ^  ,  ^^;,„.„t 

PAINTS,  GRINDING  OF.    There  are  many  pigments,  such  as  common  orpimenik 


^%- 


320 


PALLADIUM. 


yellow,  and  verdigris,  which  are  strong  poisons;  others  which  are  yerr 
IS,  and  occasion  dreadful  maladies,  such  as  white  lead,  red  lead,  chrome  yel- 


or  kings 

deleterious, .  -  u  -    j 

low,  and  Vermillion ;  none  of  which  can  be  safely  ground  by  hand  with  the  slab  and 
muller,  but  sliould  always  be  triturated  in  a  mill.  The  emanations  of  white  lead 
cause,  first,  tliat  dangerous  disease  the  colka  pictonum^  afterwards  paralysis,  or  prema- 
ture decrepitude  and  lingering  death. 

Ftgs.  1025  1026  1027  1028 exhibit  the  construction  of  a  good  color-  mill  in  three  views; 

^g.l025being  an  elevation  shown  upon 
the  side  of  the  handle,  or  where  the 
power  is  applied  to  the  shaft  ;  Jig.  1026 
a  second  elevation,  taken  upon  the  side 
of  the  line  c,  d,  of  the  plan  or  bird's-eye 
viewj^g.  1027. 

The  frame-work  a  a  of  the  mill  is 
made  of  wood  or  cast  iron,  strongly 
mortised  or  bolted  together;  and 
strengthened  by  the  two  cross  iron  bars 
B,  p  Fig.  1028  is  a  plan  of  the  mill- 
stones. The  lying  or  nether  millstone  c, 
fig  1026  is  of  cast  iron,  and  is  channelled 
on  its  upper  face  like  corn  millstones.  It 
is  fixed  upon  the  two  iron  bars  b,  b  ; 
but  may  be  preferably  supported  upon 
the  3  points  of  adjustable  screws,  pass- 
ing up  through  bearing-bars.  The 
millstone  c  is  surrounded  by  a  large 
iron  hoop  d,  for  preventing  the  pasty- 
consistenced  color  from  running  over 
the  edge.  It  can  escape  only  by  the 
sluice  hole  e,  fig.  1026  formed  in  the  hoop;  and  is  then  received  in  the  tub  x  placed  be- 
neath. 

The  upper  or  moving  millstone  f,  is  also  made  of  cast  iron.  The  dotted  lines  indi. 
eate  its  shape.  In  the  centre  it  has  an  aperture  with  ledges  g,  g  ;  there  is  also  a  ledge 
upon  its  outer  circumference,  suflSciently  high  to  confine  the  color  which  may  oc- 
casionally accumulate  upon  its  surface.  An  upright  iron  shaft  h  passes  into  the  turning 
stone,  and  gives  motion  to  it.  A  horizontal  iron  bevel  wheel  k, /gs.  1026,1027  fur 
nished  with  27  wooden  teeth,  is  fixed  upon  the  upper  end  of  the  upright  shaft  h.  A 
similar  bevel  wheel  l,  having  the  same  number  of  teeth,  is  placed  vertically  upon  th» 
horizontal  iron  axis  m,  m,  and  works  into  the  wheel  k.  This  horizontal  axis  m,  m  bears, 
at  one  of  its  ends,  a  handle  or  winch  n,  by  which  the  workman  may  turn  the  millstone 
r ;  and  on  the  other  end  of  the  same  axis,  the  fly-wheel  o  is  made  fast,  which  servcK 
to  regulate  the  movements  of  the  machine.  Upon  one  of  the  spokes  of  the  fly-wheel 
there  is  fixed,  in  like  manner,  a  handle  p,  which  may  serve  upon  occasion  for  turning 
the  mill.  This  handle  may  be  attached  at  any  convenient  distance  from  the  centre,  by 
means  of  the  slot  and  screw-nut  J. 

The  color  to  be  ground  is  put  into  the  hopper  r,  below  which  the  bucket  s  is  sus- 
•>ended,  for  supplying  the  colo*"  uniformly  through  the  orifice  in  the  mil'stone  g.  A 
cord  or  chain  t,  by  means  of  which  the  bucket  s  is  suspended  at  a  proper  height  for 
pouring  out  the  requisite  quantity  of  color  between  the  stones,  pulls  the  bucket  obliquelj-, 
and  makes  its  beak  rest  against  the  square  upright  shaft  h.  By  this  means  the  bucket 
is  continually  agitated  in  such  a  way  as  to  discharge  more  or  less  color,  according  to  its 
degree  of  inclination.  The  copper  cistern  x,  receives  the  color  successively  as  it  is  ground ; 
and,  when  full,  it  may  be  carried  away  by  the  two  handles  z,  z ;  it  may  be  emptied  by  the 
stopcock  Y,  without  removing  the  tub. 

PAINTS,  VITRIFIABLE.  See  Porcelain,  Pottery,  and  Stained  Glass. 
PALLADIUM,  a  rare  metal,  possessed  of  valuable  properties,  was  discovered  in  1803, 
by  Dr.  WoUaston,  in  native  platinum.  It  constitutes  about  1  per  cent,  of  the  Columbian 
ore,  and  from  |  to  1  per  cent,  of  the  Uralian  ore  of  this  metal ;  occurring:  nearly  pure  in 
loose  grains,  of  a  steel-gray  color,  passing  into  silver  white,  and  of  a  specific  gravity  of 
from  ll'S  to  12*14;  also  as  an  alloy  with  gold  in  Brazil,  and  combined  with  selenium  in 
the  Harz  near  Tilkerode.  Into  the  nitro-muriatic  solution  of  native  platinum,  if  a  solu- 
tion of  cyanide  of  mercury  be  poured,  the  pale  yellow  cyanide  of  palladium  will  be  thrown 
down,  which  being  ignited  affords  the  metal.  This  is  the  ingenious  process  of  Dr.  Wol- 
laston.  The  palladium  present  in  the  Brazilian  gold  ore  may  be  readily  separated  as 
follows  :  melt  the  ore  along  with  two  or  three  parts  of  silver,  granulate  the  alloy,  and  di 
gest  it  with  heat  in  nitric  acid  of  specific  gravity  1-3.  The  solution  containing  the  silver 
and  palladium,  for  the  gold  does  not  dissolve,  being  treated  with  common  salt  or  muriatic 


k 


PAPER  CUTTING. 


aai 


acid  TTfll  part  with  all  its  silver  in  the  form  of  a  chloride.    The  ^"l^JJ^^^^Y^^"^';'^^^^^^ 
J^i'rat'ed  and  neutralized  ^th  -7--;,-^^^^^ 
crystals,  the  ammonia-muriate  of  palladium,  which  being  wasncu 

ignited,  will  afford  40  per  cent,  of  metal.  ..    *  v    *\,^  r«rni*.r.  nnd  if  it  be 

The  metal  obtained  by  this  process  is  purer  than  that  ^y/f  ^^*»J°!^VrP  "r  foree  a 
fused  i^a  crucible  along  with  borax,  by  the  heat  of  a  powerful  a^r-fura^^^^^^^ 

"^Th;re  are  a  protoxyde  and  peroxyde  of  palladium.    The  proto-chloride  consists  of  60 

^.^  It  may  ll  bleached  by  the  action  of  either  chlorine  or  oxygen  g«^  as  also  b, 
^'wm  It irp^rte'fin  1860.  447,797  owts,  in  1851.  608.650  cwt. ;  exported  in  185* 
'''^T,m''vX:'Tlt74:^Uo.  of  this  fabrie  is  thus  ae«.jW  in  «.e  sp^ 
fication  of  Mr.  Henry  Chapman's  P-'™'  ""'"J^' l„*f;^„i  whkh  is  .X^ 

endless  wire  wheel  of  the  machine  paper  is  'f^^^f'^'J'^^^^^  U  the  cloth  is 

endless  sheet  of  paper  has  been  led  *  {^^g^^ Jj^f^^h  and  moved  onwards  in  tha 
brought  oyer  the  upper  P-J.^/^^^^-^^^Xn  oVthe^^^^^^^^^^  r'ler  to  revolve, 

direct  on  the  paper  is  proceeding.     The  motion  oi  ^^^Z-  "''"';"   ,  ,     . ,       |^j    ^^jjch  it 

and  the  adhesive  material  «?;"-<!  "P^«  ^^.^^^^^StJ^j^^^^ 

then  laid  upon  the  paper,  as  it  passes  over  the  roller  »°^™f XthlK^^^         firmly 

tio^n^'lf  t'^cTotT^e  dreTsS^^^^^    strong  starch.the  bath  of  adUve  -  uti- may  ba 
T     JlA^ith     The  following  prescription  is  given  for  making  that  solution  .— 
dispensed  with.    The  tollowing  p       j      ^^^\omh\ne  with  this  solution,  by  means 
of K  parti  or/eUowrsn^  aUour,  adding  a  little  linseed  oil  t.>  prevent 

?roth?ng  and  add  Tpart  of  glue  to  the  mixture ;  after  which  di  ute  the  whole  with  ona 
rn<S«h;if  times  its  weight  of  water,  and  strain  through  flannel  Thirty  parts  of  this 
Sm^oSnTre  t^bTX^  with  oie  part  of  flour-paste,  and  six  part«  of  paper-pulp 

^PaVe^CUTONG  Crompton,  of  Farnworth.  Lancashire,   who  olj 

f  •  tJ  a  r>atenTin  May  1821,  for  proposing  to  conduct  the  newly  formed  web  of 
^aper  in  treTourdriS  machine  ov^er  heatel  cylinders,  for  the  puriK^se  of  drying  i* 
^Seditiously,  in  imitation  of  the  mode  so  long  practised  in  drj^g  calicoes  obU.ned. 

-ilatifen^i^^rti^o'in^J^^^^^^^^^^ 

Vol.  XL  ^^ 


I    I 


822 


PAPER  CUTTING. 


PAPER  CUTTING 


328 


1  i 


paper,  by  Mr.  Edward  Cowper,  consisting  of  a  machine,  with  a  ree'i  on  which  the  weh 
of  paper  of  very  considerable  length  has  been  previously  wound,  in  the  act  of  being  made 
in  a  Fourdrinier's  machine  ;  this  web  of  paper  being  of  sufficient  width  to  produce  two, 
three,  or  more  sheets,  when  cut. 

The  several  operative  parts  of  the  machine  are  mounted  upon  standards,  or  frame- work 
of  any  convenient  form  or  dimensions,  and  consist  of  travelling  endless  tapes  to  conduct 
the  paper  over  and  under  a  series  of  guide  rollers ;  of  circular  rotatory  cutters  for  the 
purpose  of  separating  the  web  of  paper  into  strips  equal  to  the  widths  of  the  intended 
sheets ;  and  of  a  saw-edged  knife,  which  is  made  to  slide  horizontally  for  the  purpose  of 
separating  the  strips  into  such  portions  or  lengths  as  shall  bring  them  to  the  dimensions 
of  a  sheet  of  paper. 

The  end  of  the  web  of  paper  from  the  reel  a,  fig  1029  is  first  conducted  up  an  inclined 
plane  b  by  hand ;  it  is  then  taken  hold  of  by  endless  tapes  extended  upon  rollers,  as 
in  Mr.  Cowper's  Printing  Machine,  which  see.  These  endless  tapes  carry  the  web  of 
paper  to  the  roller  c,  which  is  pressed  against  the  roller  d  by  weighted  levers,  acting 
upon  the  plummer  blocks  that  its  axle  is  mounted  in.  The  second  roller  d  may  be 
either  of  wood  or  metal,  having  several  grooves  formed  round  its  periphery  for  the 
purpose  of  receiving  the  edges  of  the  circular  cutters  e,  (see  Cabd-cuttinq)  mounted 
upon  an  axle  turning  upon  bearings  in  the  standards  or  frame. 

In  order  to  allow  the  web  of  paper  to  proceed  smoothly  between  the  two  rollers^  e, 
4  a  narrow  rib  of  leather  is  placed  round  the  edges  of  one  or  both  of  these  rollers^ 


for  the  purpose  of  leaving  a  free  space  between  {hena,  through  which  the  paper  may 
pass  without  wrinkling. 

Fi'om  the  first  roller  c,  the  endless  tapes  conduct  the  paper  over  the  second  d,  and 
then  under  a  pressing  roller/,  in  which  progress  the  edges  of  the  circular  knives  e,  re- 
volving in  the  grooves  of  the  second  roller  d,  cut  the  web  of  paper  longitudinally  into 
strips  of  such  widths  as  may  be  required,  according  to  the  number  of  the  circular 
cutters  and  distances  between  them. 

The  strips  of  paper  proceed  onward  from  between  the  knife  roller  d  and  pressing  rol- 
ler/, conducted  by  tapes,  until  they  reach  a  fourth  roller  g,  when  they  are  allowed  to  descend, 
and  to  pass  through  the  apparatus  designed  to  cut  them  transversely ;  that  is,  into  sheet 
lengths. 

The  apparatus  for  cutting  the  strips  into  sheets  is  a  sliding  knife,  placed  horizontally 
upon  a  frame  at  A,  which  frame,  with  the  knife  «,  is  moved  to  and  fro  by  a  jointed  rod  i,  con- 
nected to  a  crank  on  the  axle  of  the  pulley  k.  A  flat  board  or  plate  /  is  fixed  to  the  standard 
frame  in  an  upright  position,  across  the  entire  width  of  the  machine ;  and  this  board  or 


plate  has  a  groove  or  opening  cut  along  it  opposite  to  tne  edge  of  the  knife.  The  paper 
descending  from  the  fourth  roller  g  passes  against  the  face  of  this  board,  and  as  the  carnage 
with  the  knife  advances,  two  small  blocks,  mounted  upon  rods  with  springs  m  m,  come 
against  the  paper,  and  hold  it  tight  to  the  board  or  plate  /,  while  the  edge  of  the  knife  is 
pn>vuded  forwards  into  the  groove  of  that  board  or  plate,  and  its  sharp  saw-shaped  teeth 
passing  through  the  paper,  cut  one  row  of  sheets  from  the  descending  strips ;  which,  on 
the  withdrawing  of  the  blocks,  falls  down,  and  is  collected  on  the  heap  below. 

The  power  for  actuating  this  machine  is  applied  to  the  reverse  end  of  the  axle,  on  which 
the  pulley  k  is  fixed,  and  a  band  n,  n,  n,  n,  passing  from  this  pulley  over  tension  wheels  o, 
drives  the  wheel  q  fixed  to  the  axle  of  the  knife  roller  d ;  hence  this  roller  receives  the 
rotatory  motion  which  causes  it  to  conduct  forward  the  web  of  paper,  but  the  other  rollers 
c  and/,  are  impelled  solely  by  the  friction  of  contact. 

The  rotation  of  the  crank  on  the  axle  of  fe,  through  the  intervention  of  the  crank-rod  i, 
moves  the  carriage  h,  with  the  knife,  to  and  fro  at  certain  periods,  and  when  the  spring 
blocks  m  come  against  the  grooved  plate  i,  they  slide  their  guide  rods  into  them,  while  the 
knife  advances  to  sever  the  sheets  of  paper.  But  as  sheets  of  different  dimensions  are 
occasionally  required,  the  lengths  of  the  slips  delivered  between  each  return  of  the  knife 
are  to  be  regulated  by  enlarging  or  diminishing  the  diameter  of  the  pulley  fc,  which  will  of 
course  retard  or  facilitate  the  rotation  of  the  three  conducting  rollers,  c,  d,/,  and  cause  a 
greater  or  less  length  of  the  paper  to  descend  between  each  movement  of  the  knife  carriage. 

The  groove  of  this  pulley  fe,  which  is  susceptible  of  enlargement,  is  constructed  of 
wedge-formed  blocks  passed  through  its  sides,  and  meeting  each  other  in  opposite  direc- 
tions, so  that  on  drawing  out  the  wedges  a  short  distance,  the  diameter  of  the  pulley  be- 
comes diminished ;  or  by  pushing  the  wedges  further  in,  the  diameter  is  increased;  and  a 
tension  wheel  p  being  suspended  in  a  weighted  frame,  keeps  the  band  always  tight. 

As  it  is  necessary  that  the  paper  should  not  continue  descending  while  it  is  held  by  the 
blocks  m,  m  to  be  cut,  and  yet  that  it  should  be  led  on  progressively  over  the  knife  roller  d, 
the  fourth  roller  g,  which  hangs  in  a  lever  j,  is  made  to  rise  at  that  time,  so  as  to  take  up 
the  length  of  paper  delivered,  and  to  descend  again  when  the  paper  is  withdrawn.  This 
is  eflfectwi  by  a  rod  r,  connected  to  the  crank  on  the  shaft  of  the  aforesaid  roller  fc,  and  also 
to  the  under  part  of  the  lever  j,  which  lever  hanging  loosely  upon  the  axle  of  the  knife 
roller  d,  as  its  fulcrum,  vibrates  with  the  under  roller  g,  so  as  to  effect  the  object  in  the 
way  described. 

The  patentee  states  that  several  individual  parts  of  this  majhine  are  not  new,  and  thai 
some  of  them  are  to  be  found  included  in  the  specifications  of  other  persons,  such  as  the 
circular  cutters  «,  which  are  employed  by  Mr.  Dickinson  (Card-cutting),  and  the  horizon- 
tal cutter  hy  by  Mr.  Hansard ;  he  therefore  claims  only  the  general  arrangement  of  the  parts 
in  the  form  of  a  machine  for  the  purpose  of  cutting  paper,  as  the  subject  of  his  invention. 

The  machine  for  cutting  paper  contrived  by  John  Dickinson,  Esq.  of  Nash  Mill 
was  patented  in  January,  1829.     The  paper  is  wound  upon  a  cylindrical  roller  a,  fig.  1030 


,11 


1   J   J'  ^r 


1030 


y 


nnr 


motinted  upon  an  axle,  supported  in  an  iron  frame  or  standard.  From  this  roller  the 
paper  in  its  breadth  is  extended  over  a  conducting  drum  6,  also  mounted  upon  an  axle 
turnin"  in  the  frame  or  standard,  and  after  passing  under  a  small  guide  roller,  it 
process  through  a  pair  of  drawing  or  feeding  rollers  c,  which  carry  it  into  the  suiting 

machine.  ^  .  •    ,    j  _j 

Upon  a  table  a,  rf,  firmly  fixed  to  the  floor  of  the  building,  there  is  a  series  of  chisel-edgcd 
knives  c,  c,  e,  placed  at  such  distances  apart  as  the  dimensions  of  the  cut  sheets  of  paper  are 
intended  to  be.  These  knives  are  made  fast  to  the  table,  and  against  them  a  series  of 
cu-cular  cutters/, /,/,  mounted  in  a  swinging  frame  g,  g,  are  intended  to  act.    The  length 


334 


PAPER  CUTTING. 


PAPER-HANGINGS.^ 


325 


9*    <  »r   • 

1!-  -". 


of  paper  oeing  brought  along  the  table  over  the  edges  of  the  knives,  tip  to  a  stop  ^,  the 
cutters  are  then  swung  forwards,  and  by  passing  over  the  paper  against  the  stationary 
knives,  the  length  of  paper  becomes  cut  into  three  separate  sheets. 

The  frame g,g,  which  carries  the  circular  cutters/,/,/,  hangs  upon  a  very  elevated  axle, 
in  order  that  its  pendulous  swing  may  move  the  cutters  as  nearly  in  a  horizontal  line  as 
possible ;  and  it  is  made  to  vibrate  to  and  fro  by  an  eccentric,  or  crank,  fixed  upon  a 
horizontal  rotatory  shaft  extending  over  the  drum  6,  considerably  above  it,  which  may  be 
driven  by  any  convenient  machinery. 

The  workmen  draw  the  paper  from  between  the  rollers  c,  and  bring  it  up  to  the  stop  h, 
m  the  intervals  between  the  passing  to  and  fro  of  the  swing-cutters. 

The  following  very  ingenious  apparatus  for  cutting  the  papCT  web  transversely  into 
any  desired  lengths,  was  made  the  subject  of  a  patent  by  Mr.  E.  N.  Fourdrinier,  in 
Jane,  1831,  and  has  since  been  performing  its  duty  well  in  many  establishnents. 
^ijr*10^1is  an  elevation,  taken  upon  one  side  ot  the  machine ;  and  Jig.  1032  is  a  longi 

tudinal  section,  a,  a,  a,  a, 
are  four  reels,  each  cover- 
ed with  one  continuous 
sheet  of  paper ;  which  reels 
are  supported  upon  bear- 
ings in  the  frame-work 
6,  6,  b.  c,  c,  c,  is  an  end- 
less web  of  felt -cloth  passed 
over  the  rollers  rf,  d,  d,  d, 
which  is  kept  in  close  con- 

tact  with  the  under  side  of 

1     )     the  drum  e,  e,  seen  best  ia 
"'^     fig.  1032. 

The  several  parallel 
layers  of  paper  to  be  cut, 
being  passed  between  the 
drum  «,  and  the  endless 
felt  c,  will  be  drawn  off 
their  respective  reels,  and 
fed  into  the  machine,  when- 
ever the  driving-band  is  slid 
from  the  loose  to  the  fast 
pulley  upon  the  end  of  the 
main  shaft  /.  But  since 
the  progressive  advance  of 
the  paper-webs  must  be 
arrested  during  the  time  of 
making  the  cross  cut 
through  it,  the  following 
apparatus  becomes  neces- 
sary. A  disc  g,  which 
carries  the  pin  or  stud  of  a 
crank  t,  is  made  fast  to  the 
end  of  the  driving  shaft  /. 
This  pin  is  set  in  an  adjust- 
able sliding  piece,  which 
may  be  confined  by  a  screw 
within  the  bevelled  gra- 
duated groove,  upon  the 
face  of  the  disc  g,  at  vari- 
able distances  from  the  ax- 
is, whereby  the  eccentricity  of  the  stud  »,  and  of  course  the  throw  of  the  crank,  may  be 
considerably  varied.  The  crank  stud  t,  is  connected  by  its  rody,  to  the  swinging  curvilin- 
ear rack  fc,  which  takes  into  the  toothed  wheel  /,  that  turns  freely  upon  the  axle  of  the 
feed  drum  e,  e.  From  that  wheel  the  arms  m,  m,rise,  and  bear  one  or  more  palls  n,  which 
work  in  the  teeth  of  the  great  ratchet  wheel  o,  o,  mounted  upon  the  shaft  of  the  drum  e. 

The  crank-plate  g  being  driven  round  in  the  direction  of  its  arrow,  will  communi- 
eate  a  see-saw  movement  to  the  toothed  arc  k,  next  to  the  toothed  wheel  /  in  gearing 
with  it^  and  an  oscillatory  motion  to  the  arms  m,  tn,  as  also  to  their  surmounting  pall  n. 


J 


In  it,  «.mg  to  the  left  hand,  the  catch  of  the  P^'' 'T'll ''^^riay  hoKh^^  ^ 
rf  the  ratchet  wheel  o ;  but  in  its  return  to  '"ejig'.t  hand  .1  W'"  »». ''°'''  ^^^  ,  ^ 

Tnd  pull  Ihem,  with  their  attached  "l"^';^.";™^/^,'^;' °Jat  te  *us  d«wn  forwari  at 
naner  in  close  contact  with  the  under  halfol  »''«.^™"  ""'°*  7.~'„j,„s  felt,  and  iu 
SSTr^als,  fron,  the  reels,  by  the  friction  between  -Js  surfece  and  *^fdl%s  'e  t,  %^^^ 

lengths  corresponding  to  the  arc  of  ^'^.™''°""'ttae  when  the  swingarc  is  making  iU 
lengths  transversely  'ibrough  .n^a-;"-  ^tftTvl  tt  slopesTrhe  ratchet  teeth  o. 
inactive  stroke,  viz.,  when  it  is  s'"""*  ",; '„  ,„  ,.,.  dis,.„ce  of  the  crank  stud  t,  from 
The  extent  of  to  vxbr^^^^^^^^^  I'^t^T^^fe.le^i  of  the  oscillations 

the  centre/,  of  the  plate  g,becaus^  ^^  ^^^^  ^^^^  ^^^^  ^^^  f^ 

of  the  curvilinear  rack,  and  that  «»  tnejoj  .^^  ^^^^^^  ^.^^  ^^^  ^^^ 

forwards  to  the  ^n^fe  apparatu  .     'H^^^^^  .  ^^^  ^  ^^  ^^^  ^^^^.^^  ^^^^  ^     hears 

above  described  "^^I^^J^^^sS  the  wf^r  ,,  in  its  revolution  with  the  shaft/,  lifts  the 
r,  r,  whose  under  ^ade  J/s  ftxed,  tne  w^^^^^  mo%eable  blade  v  (as  shown  m 

toil  of  the  lever  /,  consequently  depresses  uie  ^  obliquely,  like  a  pair  of  scissors, 

fig.  783),  and  slides  ^^^^^^"^^^^^^^^^^^^  before  the  shears  begin  to 

80  as  to  cause  a  clean  cut  afTO^V^e  pues  oi  j  ai  j  ^^^  ^^^^  .^  ^^^ 

operate,  the  transverse  board  u  descends  to  press  the  paper  wu  |  ^  ^^^  ^^ 

upon  the  bed  r.     During  the  action  pf^he  upper  bla^  bell-crank 

bStrd  u,  is  suspended  by  a  cord  P*^^;"|,\"^^^\PJ^X^^^^^^  bell-crank  t, 

lever  /,  t     Whenever  the  ^f  ^ --^^^^^^^^^^^  board  «,  to  be 

the  weight  *>  ^""-  "^J^,^\r^^^^  paper,  which  is  regularly  brought  for- 

moved  up  out  of  the  way  of  the  next  len  m  "» J   {^  '     ^  j^j  j      f  t^e  shears 

s!:5i?^afa?;*^ri°^-Stfj:g'uirpSc^4^^^^^ 

•"^'a^ER-HANGINGS,  callM  more  vro.^^^yJ^^^^'^^^J^P^:  i^thinl'^ 
art  of  making  paper-hangings,  p<.p«r  "^.''"^"'^^^^.."PxhrEnUh  first  imported 
among  whom  it  has  been  practised  from  time  'mmemonal.     '  »^  ^-^S^  ^^J^^^  ^ 

and  b'egan  to  imitate  the  Chinese  Papej-haa?'"?^!  „„ '  e^"^^  '"«  ll"'  «^^^^ 
high  excise  duty  upon  the  manufacture,  Jh^J  »^™  ""' S"'  j "  Unchecked  by  taxation, 
of  refinement  which  the  French  genius  ''»l,b/„="  ,?"^^'^/^,i°' 7"„^^^^  i„  /„  extended 
The  first  method  of  making  this  paper  was  stencil  ing  •  "^ '"^'21  "^^  jevices,  and  applj- 
rtate,  a  piece  of  pasteboard  having  spa«s  <="'  »"'  f  ^^™^  ^"t^ari  wi  h  other*^^'- 
ing  different  water  co  ors  wrth  '^e  brush     Anothcrj^eo^  pasteDo  ^^^  ^^^^ 

"ta^rritrngings  may  be  mstinguished  into  two  classes,   1    ^^^:'^^,;^^, 
^:it::i  a:  't ":    \?d\^.rosf  Trch'tL'^ns  areZmed^b,  foreign  maU 

to«'ether:  or  a  Fourdrinier  web  of  paper  should  be  taken.  i^Voc  t^;,.Vpn«l  with 

4    Lading  the  grounds,  is  done  with  earthy  colors  or  colored  lakes  thickened  with 

^'V::':^^^^^^^  or  two  chiWren,  can  lay  the  grounds  of  300  pieces  in  a 

^av  The  nieces  are  n^w  suspended  upon  poles  near  the  ceiUng,  m  order  to  be  dried 
&'  ar^^AcnTolirup  and  carried  to  the  apartment  where  they  are  polished,  by  l^ing 
J^\Zn  a  'moo  h  tabre,  with  the  painted  side  undermost,  and  f  "fed  with  the  T«hsh« 
PicciC^ided  to  be  satined,  are  grounded  with  fine  P'^ns  P^^f^  ^'Jf'ead  of  Sparush 
white .  and  are  not  smoothed  with  a  brass  polisher,  but  with  a  hard  ^J^^sJ  ^^^.f  hh 
Se  loi-*^  onYof  the  swing  polishing  rod.  After  spreading  the  piece  "Pon  the  table  wUh 
SeC^led  side  undermost,  the  paper-stainer  dusts  the  upper  surface  with  finely  pow- 
dered  clSk  of  Brian^on,  commonly  called  talc,  and  rubs  it  strongly  with  the  brush.  In 
this  way  the  satiny  lustre  is  produced. 

THE  PRINTING  OPERATIONS. 

Blocks  about  two  inches  thick,  formed  of  three  separate  boards  glued  togeAer  of 
whicHwo  are  made  of  poplar,  and  one  (that  which  is  engraved)  of  pear-tree  or  sye. 


326 


PAPER-HANGINGS. 


PAPER,  MANUFACTURE  OF. 


327 


i  ] 


t 


■J      n 


more,  are  used  for  printing  paper-hangings,  as  for  calicoes.  The  gram  of  the  upper 
layer  of  wood  should  be  laid  across  that  of  the  layer  below.  As  many  blocks  are  re- 
quired as  there  are  colors  and  shades  of  color.  To  make  the  figure  of  a  rose,  for  example, 
three  several  reds  must  be  applied  in  succession,  the  one  deeper  than  the  other,  a  white 
for  the  clear  spaces,  two  and  sometimes  three  greens  for  the  leaves,  and  two  wood  colors 
for  the  stems  ;  altogether  from  9  to  12  for  a  rose.  Each  block  carries  small  pin  points 
fixed  at  its  comers  to  guide  the  workman  in  the  insertion  of  the  figure  exactly  in  its  place. 
An  expert  hand  places  these  guide  pins  so  that  their  marks  are  covered  and  concealed 
by  the  impression  of  the  next  block ;  and  the  finished  piece  shows  merely  those  belonging 
to  the  first  and  last  blocks. 

In  printing,  the  workman  employs  the  same  swimming-tub  apparatus  which  has  been 
described  under  block  printing  (see  Calico-printing),  takes  ofl"  the  color  upon  hij 
blocks,  and  impresses  them  on  the  paper  extended  upon  a  table  in  the  very  same  way. 
The  tub  in  which  the  drum  or  frame  covered  with  calf-«kin  is  inverted,  contains  simply 
water  thickened  with  parings  of  paper  from  the  bookbinder,  instead  of  the  pasty  mixture 
employed  by  the  calico-printers.  In  impressing  the  color  by  the  block  upon  the  paper, 
he  employs  a  lever  of  the  second  kind,  to  increase  the  power  of  his  arm,  making  it  act 
upon  the  block  through  the  intervention  of  a  piece  of  wood,  shaped  like  the  bridge  of  a 
violin.  This  tool  is  called  tasseau  by  the  French.  A  child  is  constantly  occupied  in 
spreading  color  with  a  brush  upon  the  calf-skin  head  of  the  drum  or  sieve,  and  in  sliding 
off  the  paper  upon  a  wooden  trestle  or  horse,  in  proportion  as  it  is  finished.  When  thb 
piece  has  received  one  set  of  colored  impressions,  the  workman,  assisted  by  his  little  aid, 
called  a  tireur  (drawer),  hooks  it  upon  the  drying-poles  under  the  ceiling.  A  sufllicient 
number  of  pieces  should  be  provided  to  keep  the  printer  occupied  during  the  whole  at 
least  of  one  day,  so  that  they  will  be  dried  and  ready  to  receive  another  set  of  colored  im- 
pressions by  the  following  morning. 

All  the  colors  are  applied  in  the  same  manner,  every  shade  being  formed  by  means  of 
the  blocks,  which  determine  all  the  beauty  and  regularity  of  the  design.  A  pattern  draw- 
er of  taste  may  produce  a  very  beautiful  efl'ect.  The  history  of  Psyche  and  Cupid,  by  M, 
Dufour,  has  been  considered  a  masterpiece  in  this  art,  rivalling  the  productions  of  the 
pencil  in  the  gradation,  softness,  and  brilliancy  of  the  tints. 

When  the  piece  is  completely  printed,  the  workmen  looks  it  all  over,  and  if  there  be 
any  defects,  he  corrects  them  by  the  brush  or  pencil,  applying  first  the  correction  of  one 
color,  and  afterwards  of  the  rest. 

A  final  satining,  after  the  colors  are  dried,  is  communicated  by  the  friction  of  a  finely 
polished  brass  roller,  attached  by  its  end  gudgeons  to  the  lower  extremity  of  a  long 
swing-frame ;  and  acting  along  the  cylindrical  surface  of  a  smooth  table,  upon  which  the 
paper  is  spread. 

The/ondtt  or  rainbow  style  of  paper-hangings,  which  I  have  referred  to  this  place  m 
the  article  Calico-printing,  is  produced  by  means  of  an  assortment  of  oblong  narrow 
tin  pans,  fixed  in  a  frame,  close  side  to  side,  each  being  about  one  inch  wide,  two  inches 
deep,  and  eight  inches  long ;  the  colors  of  the  prismatic  spectrum,  red,  orange,  yellow, 
green,  &c.,  are  put,  in  a  liquid  state,  successively  in  these  pans ;  so  that  when  the 
oblong  brush  a,  b,  with  guide  ledges  a,  c,  d,  is  dipped  into  them  across  the  whole  of  the 
.     1034  parallel  row  at  once,  it  comes  out  impressed  with  the  different  colors 

^iTTr7~fJT^     at  successive  points  e,  e,  «,  e,  of  its  length,  and  is  then  drawn  by  the 

WWfcriai '        paper-stainer  over  the  face  of  the  woollen  drum  head,  or  sieve  of  the 

*    •  •    •  swimming  tub,  upon  which  it  leaves  a  corresponding  series  of  stripes 

in  colors,  graduating  into  one  another  h'ke  those  of  the  prismatic  spectrum.     By  applying 

his  block  to  the  tear,  the  workman  takes  up  the  color  in  rainbow  hues,  and  transfers  these 

to  the  paper.   /,/,/,/ show  the  separate  brushes  in  tin  sheaths,  set  in  one  frame. 

At  M.  Zuber's  magnificent  establishment  in  the  ancient  ch&teau  of  Rixheim,  near 
Mulhouse,  where  the  most  beatiful  French  papiers  peints  are  produced,  and  where  J 
was  informed  that  no  less  than  3000  blocks  are  required  for  one  pattern,  I  saw  a  two. 
color  calico  machine  employed  with  great  advantage,  both  as  to  taste  and  expedition. 
Steam-charged  cylinders  were  used  to  dry  the  paper  immediately  after  it  was  printed,  as 
the  colors,  not  being  so  rapidly  absorbed  as  they  are  by  calico,  would  be  very  apt  to 
spread. 

The  operations  employed  for  common  paper-hangings,  are  also  used  for  making  flock 
paper,  only  a  stronger  size  is  necessary  for  the  ground.  The  flocks  are  obtained  from 
the  woollen  cloth  manufacturers,  being  cut  off  by  their  shearing  machines,  called  lewises 
by  the  English  workmen,  and  are  preferred  in  a  white  state  by  the  French  paper-hanging 
makers,  who  scour  them  well,  and  dye  them  of  the  proper  colors  themselves.  When 
they  are  thoroughly  stove-dried,  they  are  put  into  a  conical  fluted  mill,  like  that  for 
making  snuff,  and  are  properly  ground.  The  powder  thus  obtained  is  afterwards  sift- 
ed by  a  bolting-machine,  like  that  of  the  flour  mill,  whereby  flocks  of  different  degrees 
of  fineness  are  produced.    These  are  applied  to  the  paper  after  it  has  undergone  all  tht 


I 


„nal  prinUng  opei^Uons..     Upon  the  -".^^.^^^^"^^^^^^^^  ^^fe 'J^^tu 

ing  table,  a  large  chest  is  placed  for  recemng  the  flock  I^^*^^*^  '  ^  f^^^  15  ^  18 
feet  long  two  feet  wide  at  the  bottom,  three  feet  and  »/^^f  J'/^^P' ^f„  This  chest  is 
inches  deep.  It  has  a  hinged  lid.  Its  bottom  is  made  o[JJ!J^^^^^^^  ieL  above 
called  the  drum ;  it  rests  upon  four  strong  feet,  so  as  to  stand  from  Z4  to  zo  1 

'VhrblocU  which  serves  .o  apply  the  .^he.ve  •'^.t*  ^^^S^^^il - 

The  French  workmen  caU  <-^^ '-r'r\^''^'Z%- J^^r^^^rcJ^^s  are,  and  is 
covers  the  inverted  swimmmg  tub,  in  the  same  -way  a»  w  c  writers)      The 

spread  with  a  brush  by  the  tireur  (corruptly  styled  fearer  by  ^ome  Enghsh  ^^«^^  ^  ^^ 
workman  daubs  the  blocks  upon  the  mordant,  spreads  ^^^^P^^;;^^^;^'^^;;^  ^ 

brush,  and  then  applies  it  by  i^-J^W  ^raTra\^^^^^^^^ 

the  paper  has  been  thus  <=?^e][ ^d,  the  child  draws  it  a  on    1  |  ^  ^^  ^^^^^^ 

the  flock  powder  over  it  with  his  hands ;  »«*  when  Ven^in  o   <  '^  ^    J        ^ 
It  up  within  the  drum,  and  beats  upon  the  calf.^^^^^^^^ 

a  cloud  of  flock  inside,  and  to  make  it  cover  the  P'^^P^^^fJJ^; "°" .    .k  ^:^^.,  j^  order  to 
He  now  lifts  the  lid  of  the  chest,  inverts  the  paper,  and  beats  its  back  li.hVV, 
detach  all  the  loose  particles  of  the  woolly  Po^^er-  .^^  everywhere  of  the 

By  the  operation  just  described,  the  ^^l^'^^-down  being  ^^J J'^^^t.^ueed  to 
same  color,  would  not  be  agreeable  to  the  eye,  ^/^^/^f^X  l^L^r^^^^^      folds 
relieve  the'pattern.    To  give  the  effect  of  drapery,  f^J^^^f  ^P^"'?^,^^^^^^^ 
must  be  introduced.      For  this  purpose,  when  the  piece  is  Perfectly  dry,  "»e  wo 

Sretches  it  upon  his  table,  and  by  the  ^.-d--/,^;.^^^^^^^^  Xd^^  ^ 

"^^^oWrfTap'^iic^  upon  the  above  monlant,  when  nearl^^^^^^^ 
proper  eold  size ;  and  the  same  method  of  application  i^  resorted  ^^^^^  ^«^J''y ™  ^^ 
gilding  of  wood.    When  the  size  has  become  perfectly  hard,  the  supertluous  goia  le 
is  brushed  off  with  a  dossil  of  cotton  wool  or  fine  linen. 

The  colors  used  by  the  paper-hangers  are  the  foUowins :—        ^.^,,,„  „r  the  two 

1.  Wfntes.    These  are  either  white-lead,  good  whitening,  or  a  mixture  ^^ /^^^f' 

2.  Yellmvs.  These  are  frequently  vegetable  extracts ;  ^^J^^^^^fj^^'^fc^^ltlX^ 
or  Persian  berries,  and  are  made  by  boiling  the  substances  ^ith  water.  Chrome  yeuow 
is  also  frequently  used,  as  well  as  the  terra  di  Sienn«  and  yellow  ochre. 

3.  Reds  are  almost  exclusively  decoctions  of  Brazil  wooo. 

4.  Blues  are  either  Prussian  blue,  or  blue  verditer.  couDer: 

5.  Greens  are  Scheele»s  green,  a  combination  «f  «^«"^°"^,,f "V^^e^  Jnd  yellow?^ 
the  green  of  Schweinfurth,  or  S-en  verdUer ;  as  also  a  m^^^^^^^^ 

6.  Violets  are  produced  by  a  mixture  of  blue  and  ^^^^Uh^nxL 

may  be  obtained  directly  by  mixing  a  decoction  of  l<>f,^°??^^f  ..^l^-  ^^^^^^  ^  either 

common  ivory  or  Frankfort  black ;  and  grays  are  loruicu  uj  u^^ 

^'"illTe"^^^  rendered  adhesive  and  consistent,  by  being  worked  up  with  gelatinous 
siztra'w^lrsoK^^^^^^^       liquefied  in  a  kettle.     Many  ^tjie  color^^^^^^^^ 
thickened,  however,  with    starch.      Sometmies    colored    lakes    are  employed.      bee 

^VTpER,  MANUFACTURE  OF.  ^Papeterie  Fr. ;  P<'P^'!l''^^^l.^^^ 
This  most  Useful  substance,  which  has  procured  for  the  moderns  an  "^f^^j^^^^^^^J^^^f  ^^^^^^ 
over  the  ancients,  in  the  means  of  diffusing  and  P«n>etuatingknowk^e  seems  to  hav^ 
been  first  invented  in  China,  about  the  commencement  of  ^^e  Chnstian  era  and  was 
thence  brought  to  Mecca,  along  with  the  article  tself,  about  the  ^^f'^?  ^^^^^.^^^ 
century;  whence  the  Arabs  carried  it,  in  their  rapid  career  of  conquest  «^"d  colonizati^, 
to  tht  coasts  of  Barbary,  and  into  Spain,  about  the  end  of  the  9th  or  begmnmg  of  the 

'^Vorer""  accounts,  this  art  originated  in  Greece,  where  it  was  first  made  f^^ 
cotton  fibres,  in  the  course  of  the  tenth  century,  and  continued  there  ^V^PJ^^J.^^^J^^^^^^ 
the  next  three  hundred  years.  It  was  not  till  the  beginning  of  the  J^th  century 
that  paper  was  made  from  linen  in  Europe,  by  the  establishment  ^^  f  P*f  ""^arU 
1390,  al  Nuremberg  in  Germany.  The  first  English  paper-miU  ^»f  ,%^^^^^^J  f^" 
ford  by  a  German  jeweller  in  the  service  of  Queen  Elizabeth  about  the  >ear  158^ 
But  the  business  was  not  very  successful ;  in  consequence  of  ^.»^ich  for  a  lon^  penod 
afterwards,  indeed  till  within  the  last  70  years,  this  <^«««t'T^.„^Y'Lte  LiS  Ught  ^ 
writing  pal>er8  from  France  and  Holland.      Nothing  places  m  a  more  stnkmg  UgM  ine 

59 


'--v 


9m 


PAPER,  MANUFACTURE  OF. 


'] 


t«st  improvement  which  has  taken  place  in  all  the  mechanical  arts  of  England  since  the 
era  of  Arkwri^ht,  than  the  condition  of  our  paper-machine  factories  now,  compared 
with  those  on  the  Continent.  Almost  every  good  automatic  paper  mechanism  at  pre&ent 
mounted  in  France,  Germany,  Belgium,  Italy,  Russia,  Sweden,  and  the  United  States, 
has  either  been  made  in  Great  Britain,  and  exported  to  these  countries,  or  has  been  con- 
structed in  them  closely  upon  the  English  models. 

Till  within  the  last  30  years,  the  linen  and  hempen  rags  from  which  paper  was  made, 
were  reduced  to  the  pasty  state  of  comminution  requisite  for  this  manufacture  by 
mashing  them  with  water,  and  setting  the  mixture  to  ferment  for  many  days  in  close 
vessels,  whereby  they  underwent  in  reality  a  species  of  putrefaction.  It  is  easy  to  see 
that  the  organic  structure  of  the  fibres  would  be  thus  unnecessarily  altered,  nay,  frequently 
destroyed.  The  next  method  employed,  was  to  beat  the  rags  into  a  pulp  by  stamping 
tods,  shod  with  iron,  working  in  strong  oak  mortars,  and  moved  by  water-wheel  ma- 
chinery. So  rude  and  ineffective  was  the  apparatus,  that  forty  pairs  of  stamps  were 
required  to  operate  a  night  and  a  day,  in  preparing  one  hundred  weight  of  rags.  The 
pulp  or  paste  was  then  diffused  through  water,  and  made  into  paper  by  methods  similar 
to  those  still  practised  in  the  small  hand-mills. 

About  the  middle  of  the  last  century,  the  cylinder  or  engine  mode,  as  it  it  ^lled,  of 
comminuting  rags  into  paper  pulp,  was  invented  in  Holland ;  which  was  soon  aAerwardi 
adopted  in  France,  and  at  a  later  period  in  England. 

The  first  step  in  the  paper  manufacture,  is  the  sorting  of  the  rags  into  four  or  five 
qualities.  They  are  imported  into  this  country  chiefly  from  Germany,  and  the  ports  of 
the  Mediterranean.  At  the  mill  they  are  sorted  again  more  carefully,  and  cut  into 
«hreds  by  women.  For  this  purpose  a  table  frame  is  covered  at  top  with  wire  cloth 
containing  about  nine  meshes  to  the  square  inch.  To  this  frame  a  long  steel  blade  is 
attached  in  a  slanting  position,  against  whose  sharp  ed^e  the  rags  are  cut  into  squares 
or  fillets,  after  having  their  dust  thoroughly  shaken  out  through  the  wire  cloth.  Each 
piece  of  rag  is  thrown  into  a  certain  compartment  of  a  box,  according  to  its  fineness; 
seven  or  eight  sorts  being  distinguished.  An  active  woman  can  cut  and  sort  nearly  one 
cwt.  in  a  day. 

The  sorted  rags  are  next  dusted  in  a  revolving  cylinder  surrounded  with  wire  cloth, 
about  six  feet  long,  and  four  feet  in  diameter,  having  spokes  about  20  inches  Ions,  attached 
«t  right  angles  to  its  axis.  These  prevent  the  rags  from  being  carried  round  with  the 
case,  and  beat  them  during  its  rotation ;  so  that  in  half  an  hour,  being  pretty  clean,  they 
are  taken  out  by  the  side  door  of  the  cylinder,  and  transferred  to  the  engine,  to  be  first 
washed,  and  next  reduced  into  a  pulp.  For  fine  paper,  they  should  be  previously  boiled 
for  some  time  in  a  caustic  ley,  to  cleanse  and  separate  their  filaments. 

The  construction  of  the  stuff-engine  is  represented  in ^g«.  1035  1036  Fig.  1035  is  the  lon- 

Q  \\  q  gitudinal    section,   and  fig, 

*^^^         Sbg'^y ^  fj?i^&^  oV^^         V  lOBfi the  plan  of  the  engine. 

.SKC:  //  -r^^^aa    \\^*==5;^       _^  'Yhe  large  vat  is  an  oblong 

cistern  rounded  at  the  an- 
gles. It  is  divided  by  the  pari 
tition  i,  6,  and  the  whole  in- 
side is  lined  with  lead.     The 


cylinder  c,  is  made  fast  to 
the  spindle  d,  which  extends 
across  the  engine,  and  is  put 
in  motion  by  the  pinion  ;>, 
fixed  to  its  extremity.  The 
cylinder  is  made  of  wood, 
and  furnished  with  a  num- 
ber of  blades  or  cutters, 
secured  to  its  circumfer- 
ence, parallel  to  the  axis, 
and  projecting  about  an 
V\  ■I"  j//^     ^^^^     above     its     surface. 

^^V^|       I      I       I      III .J^yy  Immediately    beneath     the 

^-— — —  \n  ,  ^  u  iBe—  11 1    ^— -y  cylinder  a  block  of  wood  k 

is  placed.  This  is  mounted 
with  cutters  like  those  of 
the  cylinder,  which  in  their 
revolution  pass  very  near  to  the  teeth  of  the  block,  but  must  not  touch  it.  The  dis- 
tance between  these  fixed  and  moving  blades  is  capable  of  adjustment  by  elevating  or 
depressing  the  bearings  upon  which  the  necks  e,  «,  of  -Jie  shaft  are  supported.  These 
kearings  rest  upon  two  levers  g,  g,  which  have  tenon?  at  their  ends,  fitted  into  upright 
•ortises,  made  in  short  beams  A,  A,  bolted  to  the  side£  of  the  engine.    The  one  end  of 


PAPER,  MANUFACTURE  OF. 


329 


1037 


the  levers  g.  g,  is  moveable,  while  the  other  end  is  adapted  to  nse  an^^^" ;»P<>»  ^^ 
n  the  beam;?  A,  as  centres.     The  front  lever,  or  that  nearest  to  the^>^;;^^,^;;^^^^^ 
bleof  being   elevated  or  depressed,  by  turning  the  han^^^of  *  s^^^^^^^^^ 
view),  which  acts  in  a  nut  fixed  to  the  tenon  of  g  and  comes  Hf^^Xasses  are  let  into 

cutters  in  the  block  and  those  in  the  cylinder.  ^cx^^rA^  «nd  covered  with 

rn    Tu    1  r.  u     A  ^c  i  4;,  inq^iU  a  circular  breasting  made  of  boards,  ana  covereu  wim 

she^et  le\Vf  lttl?:^^o^  fiUbe^  very  -^^^^^^  '^::^J^s:'Z^ 

tween  the  teeth  and  breasting ;  at  its  bottom,  the    lo^  .  ^^^f;^2't^^::^i::il^^, 

t^  l^  rhS  brS?inT\n  pwitS  riSer  cases  a  flannel  bag  is  tied  round 
the  nose  "^  l^e  stopcock,  to  act  as  a  filter  ^^^  ^^^^^ 

The  rags  being  put  into  ^^^  ^^me  ^^^^^^  they  are  torn  into  the  finest  fila- 

Of  the  <=yl'"der  between  the  two  sets  o^^^^^^^^^  y       ^^^        ^^  ^^^  ^^^^^^j^^ 

ments  and  by  the  »?P"1^^« J^"^ '^^."t^  ^^^^^^  ^als  and  water  are  ,^ised  into  that  part 

upon  the  inclined  P!j^^^-^^„^J/„,f  ?f  ^he  fiqui^^  to  maintain  an  equilibrium,  puts  the  whole 
^on^enfs^S   the  ttem   n^^^^^^^  dow'n  the  inclined  plane,  to  the  left  hand  of  .  and 

contents  oi  ^"f.  ?'^^^Y  .  "  pp  th«»  arrow)   whereby  the  rags  come  to  the  cylinder  again  in 
jr';':  o7  ar«"  ^''inuus:  rrJ'  ther:r  J  repeat^U.,.  dra.n  ou,  and  separa.«i  ia 

''^^:^^^^^^^^:^>  SyTurr;  otr  ^hl-rags  in  the  engine,  causmg 
.hL  ;„  be  nrSenlerto  the  cutter  a    different  angles  every  time;  otherwise,  as  the 

r;2.L  of  ?l"  :;^^^^^^^^  IT/i^^-^^^^^^^  teeth  of  the  cylinder  c  itself  are  set 

the  axes  01  the  cyimaer,        ^^^^^^^  j^s^  ^^.^^  therefore  the  cutting  edges  meet  at  a 

small  angle,  and  come  in  contact,  first  at  the  one  end,  and 
then  towards  the  other,  by  successive  degrees,  so  that  any 
rags  coming  between  them,  are  torn  as  if  between  the  blades 
of  a  pair  of  forceps.  Sometimes  the  blades  fe  m  the  block  are 
bent  to  an  angle  in  the  middle,  instead  of  being  straight  and 

■  inclined  to  the  cylinder.     These  are  called  elbow  plates ;  their 

two  ends  being  inclined  in  opposite  directions  to  the  axis  of  the  f^f^'J^'^'^^^^l 
the  ed-es  of  the  plates  of  the  block  cannot  be  straight  lines,  but  mu^t  be  curved  to  adapt 
thPrnselves  to  the  curve  which  a  line  traced  on  the  cylinder  will  necessarily  have.     The 
Sat^   orblaSes  areTnlted  by  screwing  them  together,  and  fitting  them  into  a  cavity  cut 
piaies  or  mauess  "^  "»"        J       wlaes  are  bevelled  awav  upon  one  side  only. 
""^     "hrktSin'its  JtcTbft:i,^^^deLetai>«.,a''nd  truly  ^fJ^^^^^^Z 
nf  the  cistern   so  that  the  water  will  not  leak  through  Us  junction.     The  end  ol  it  comes 
lou^^h  tte  woc^wodc  of  the  chest,  and  projects  to  a  small  distance  on  its  outside  bemg 
kept  in  its  place  by  a  wedge.     By  withdrawing  this  wedge,  the  block  becomes  loose   and 
can  be  removed  in  order  to  sharpen  the  cutters,  as  occasion  may  be.     This  is  done  at  a 
grindstone  after  detaching  the  plates  from  each  other.  ,    -    .         ,.    . 

^  The  cutlers^  the  cylUider  are  fixed  into  grooves,  cut  in  the  wood  of  the  cylinder, 
at  equal  d  stances  asunder,  round  its  periphery,  in  a  direction  parallel  to  its  ax.^  The 
number  of  these  grooves  is  twenty,  in  the  machine  here  represented.  For  the  i^a.A«-  each 
groove  has  two  cutters  put  into  it;  then  a  fillet  of  wood  is  driven  fast  m  between  then^ 
fo  hold  them  firm ;  and  Ihe  fillets  are  secured  by  spikes  driven  into  the  solid  wood  of  the 
cylinder.     The  beater  is  made  in  the  same  manner,  except  that  each  groove  contains  three 

*"lnthe  operation  of  the  cylinder,  it  is  necessary  that  it  should  be  enclosed  in  a  cas«^ 
or  It  would  throw  all  the  water  and  rags  out  of  the  engine,  in  consequence  of  its  great 
velocity.  This  case  is  a  wooden  l)ox  m,  m,  fig.  1035  enclosed  on  every  sjde  except  the 
tottom-  one  side  of  it  rests  upon  the  edge  of  the  vat,  and  the  other  upon  the  edge  of  the 
nartilion  6,  6,  /i?-  1036.  The  diagonal  lines  m,  r,  represent  the  edges  of  wooden  frame^ 
whi'a^e  cohered  with  hair  or  wi.  e^loth,  and  immediately  behind  these  the  box  is  furnished 
With  a  bottom  and  a  ledge  towards  the  cylinder,  so  as  to  form  a  complete  trough.  The 
rauarc  fi-ures  under  n,  n,  in  /ig.  1035  show  the  situation  of  two  openings  or  spouU 
through  the  side  of  the  case,  which  conduct  to  flat  lead-pipes,  one  of  which  is  seen 
near  the  upoer  g  in  H- 103«  placed  by  the  side  of  the  vat ;  the  beam  being  cut  away  from 
Ikm.    ThSe  fri  waste  pipes  to  discharge  the  foul  watet  from  the  engine ;  because  tb« 


ft 


330 


PAPER,  MANUFACTURE  OF. 


PAPER,  MANUFACTURE  OF. 


Ml 


I 


cylinder,  as  it  turns,  throws  a  great  quantity  of  water  and  rags  up  against  the  sieves  i 
the  water  goes  through  them,  and  runs  down  to  the  trough  under  n,  n,  and  thence 
into  the  ends  of  the  flat  leaden  pipes,  through  which  it  is  discharged.  o,o,^g.  1056 
are  grooves  for  two  boards,  which,  when  put  down  in  their  places,  cover  the  hair 
sieves,  and  stop  the  water  from  going  through  them,  should  it  be  required  in  the 
engine.  This  is  always  the  case  in  the  beating  engines,  and  therefore  they  are  seldom 
provided  with  these  waste  pipes,  or  at  most  on  one  side  only ;  the  other  side  of  the  cover 
being  curved  to  conform  to  the  cylinder.  Except  this,  the  only  difference  between 
the  washing  engine  and  the  beater,  is  that  the  teeth  of  the  latter  are  finer,  there  being 
60  instead  of  40  blades  in  the  periphery;  and  it  revolves  quicker  than  the  washer,  so  that 
it  will  tear  out  and  comminute  those  particles  which  pass  through  the  leeth  of  the  washer. 
In  small  mills,  when  the  supply  of  water  is  limited,  there  is  frequently  but  one  ensine. 
which  may  be  used  both  for  washing  and  beatin?,  by  adjusting  the  screw  so  as  to  let  the 
cylinder  down  and  make  its  teeth  work  finer.  But  the  system  in  all  considerable  works, 
is  to  have  two  engines  at  least,  or  four  if  the  supply  of  water  be  great.  The  power  re- 
quired for  a  5  or  6  vat  miU,  is  about  20  horses  in  a  water-wheel  or  steam  engine. 

In  the  above  figures  only  one  engine  is  shown,  namely,  the  finisher ;  there  is  an- 
other, quite  similar,  placed  at  its  end,  but  on  a  level  with  its  snrface,  which  is  called  the 
washer^  in  which  the  rags  are  first  worked  coarsely  with  a  stream  of  water,  running 
through  them  to  wash  and  open  their  fibres ;  after  this  washing  they  are  called  half. 
»tvff,  and  are  then  let  down  into  the  bleaching  engine,  and  next  into  the  beating  engine, 
above  described. 

By  the  arrangements  of  the  mill  gearing,  the  two  cylinders  of  the  washer  and  heater 
engines  make  from  120  to  150  revolutions  per  minute,  when  the  water-wheel  moves  with 
due  velocity.  The  beating  engine  is  always  made  to  move,  however,  much  faster  than 
the  washing  one,  and  nearly  in  the  ratio  of  the  above  numbers. 

The  vibratory  noise  of  a  washing  engine  is  very  great ;  for  when  it  revolves  120  times 
per  minute,  and  has  40  teeth,  each  of  which  passes  by  12  or  14  teeth  in  the  block  at  every 
revolution,  it  will  make  nearly  60,000  cuts  in  a  minute,  each  of  them  sufficiently  loud  to 
produce  a  most  grating  growling  sound.  As  the  beater  revolves  quicker,  having  perhaps 
60  teeth,  instead  of  40,  and  20  or  24  cutters  in  the  block,  it  will  make  180,000  cuts  in  a 
minute.  This  astonishing  rapidity  produces  a  coarse  musical  humming:,  which  may  be 
heard  at  a  great  distance  from  the  mill.  From  this  statement,  we  may  easily  understand 
how  a  modern  engine  is  able  to  turn  out  a  vastly  greater  quantity  of  paper  pulp  in  a  day 
than  an  old  mortar  machine. 

The  operation  of  grinding  the  rags  requires  nice  management.  When  first  put 
into  the  washing  engine  they  should  be  worked  gently,  so  as  not  to  be  cut,  but  only 
powerfully  scrubbed,  in  order  to  enable  the  water  to  carry  off  the  impurities.  This 
effect  is  obtained  by  raising  the  cylinder  upon  its  shaft,  so  that  its  teeth  are  separated 
considerably  from  those  of  the  block.  When  the  rags  are  comminuted  too  much  in  the 
washer,  they  would  be  apt  to  be  carried  off  in  part  with  the  stream,  and  be  lost ;  for  at 
this  time  the  water-cock  is  fully  open.  After  washing  in  this  way  for  20  or  30  minutes, 
the  bearings  of  the  cylinder  are  lowered,  so  that  its  weight  rests  upon  the  cutters.  Now 
the  supply  of  water  is  reduced,  and  the  rags  begin  to  be  torn,  at  first  with  considerable 
agitation  of  the  mass,  and  stress  upon  the  machinery.  In  about  three  or  four  hours 
the  engine  comes  to  work  very  smoothly,  because  it  has  by  this  time  reduced  the  rags  to 
the  state  of  half-stuff.  They  are  then  discharged  into  a  large  basket,  through  which  the 
water  drains  away. 

The  bleaching  is  usually  performed  upon  the  half -stuff.  At  the  celebrated  manu- 
factory of  Messrs.  Montgolfier,  at  Annonay,  near  Lyons,  chlorine  gas  is  employed 
for  this  purpose  with  the  best  effect  upon  the  paper,  since  no  lime  or  muriate  of  lime 
can  be  thus  left  in  it ;  a  circumstance  which  often  happens  to  English  paper,  bleached 
in  the  washing  engine  by  the  introduction  of  chloride  of  lime  amon?  the  rags  after 
they  have  been  well  washed  for  three  or  four  hours  by  the  rotation  of  the  engine.  *  The 
current  of  water  is  stopped  whenever  the  chloride  of  lime  is  put  in.  From  1  to  2 
pounds  of  that  chemical  compound  are  sufficient  to  bleach  1  cwt.  of  fine  rass,  but  more 
must  be  employed  for  the  coarser  and  darker  colored.  During  the  bleaching  oper- 
ation the  two  sliders  o,  Oyfig.  1035  are  put  down  in  the  cover  of  the  cylinder,  to  prevent 
the  water  getting  away.  The  engine  must  be  worked  an  hour  longer  with  the  chloride 
of  lime,  to  promote  its  uniform  operation  upon  the  rags.  The  cylinder  is  usually 
raised  a  little  during  this  period,  as  its  only  purpose  is  to  agitate  the  mass,  but  not  to 
triturate  it.  The  water-cock  is  then  opened,  the  boards  rw,  m  are  removed,  and  the  wash- 
ing is  continued  for  about  an  hour,  to  wash  the  salt  away ;  a  precaution  which  ought  to 
fce  better  attended  to  than  it  always  is  by  paper  manufacturers. 

The  half-stuff  thus  bleached  is  now  transferred  to  the  beating  engine,  and  worked  into 
a  fine  pulp.  This  operation  takes  from  4  to  5  hours,  a  little  water  being  admitted  from 
time  to  time,  but  no  current  being  allowed  to  pass  through,  as  in  the  washing  engine 


1 


The  softest  and  fairest  water  should  be  selected  for  this  purpose;  ^^^^^ V*'*'?!!^ ^^ 
ministered  in  nicely  regulated  quantities,  so  as  to  produce  a  proper  spissitude  ol  stun  tor 

""rir^priS  paper,  the  sizing  is  given  in  the  beating  engine,  towards  the  end  of  ite 
operation.  The  size  is  formed  of  alum  in  fine  powder,  ground  up  ^/^^^/^l' /*  J,"^ 
mixture  about  a  pint  and  a  half  are  thrown  into  the  engine  at  mtervals,  during  the  last 
half-hour's  bealin?.  Sometimes  a  little  indigo  blue  or  smalt  is  also  a^^ed  when  a 
peculiar  b.oom  color  is  desired.  The  pulp  is  now  run  off  into  the  stuff  c^^st,  wnere 
The  different  kinds  are  mixed;  whence  it  is  taken  out  as  wanted.  The  chest  »«  usual  J 
a  rectangular  vessel  of  stone  or  wood  Uned  with  lead,  capable  of  ^^"taining  300  cubic 
feet  at  least,  or  3  engines  full  of  stuff.     Many  paper-makers  prefer  round  chests,  as  they 

•"^t:  r7pef  rmaie  in  single  sheets,  by  hand  labo.  as  in  the  older  establish- 
ments,  a  small  quantity  of  the  stuff  is  transferred  o  the  ^«'^^/"nn?p^n?  xvL  abours 
and  there  diluted  properly  with  water.  J»»'^/^/.  ^^  ^  ^f  f  ^^/f.  ^l^^^^,^^^ 
feet  square,  and  4  deep,  with  sides  somewhat  slanting.  Along  the  op  of  the  ^  a  a  Iward 
is  laid  with  copper  fil  ets  fastened  len-thwise  upon  it,  to  make  the  mould  slide  more 
easU     abn..^  T^^^^  the  bridge      The  maker  f  "'^^-^ ^^  ,f/ ^^^e 

has  to  his  left  hand  a  smaller  board,  one  end  of  which  is  made  fast  to  ^^^  ^"^f '  ^^^^^^^ 
the  other  rests  on  the  side  of  the  vat.     In  the  bridge  opposite  to  this,  a  nearly  upright 
"f  wo^,  caUeli  the  ass,  is  fastened      In  the  vat  ^here  is  a  ^PP^^^^lJ^^^^^^^^ 
Sates  with  a  steam  pipe  to  keep  it  hot ;  there  is  also  an  agitator,  to  maintain  thg  stutt  m 

'  T^TouTirS-of  frames  of  wood,  neatly  joined  at  t^e  corners  wUhw^^^^^^ 
running  across,  about  an  inch  and  a  half  apart.     Across  these,  m  the  If  ngth  of  the  moulds 
the  wi/es  run,  from  fifteen  to  twenty  per  inch      A  strong  raised  wu-e  »fj.»'^^^l«;?J«^^^^^^^ 
the  cross  bars,  to  which  the  other  wires  are  fastened;  this  gives  the  laid  paper  its  ribbed 

■''5^hTwa"V.mark  is  made  by  sewing  a  raised  piece  of  wire  in  the  ^o™  «[„ ^f^^^^' ^[,*J^J 
figured  device,  upon  the  wires  of  the  mould,  wh  ch  makes  ^^epaper  thinner  mth^e 
places.  The  frame-work  of  a  wove  mould  is  nearly  the  same  ;  ^" V?,!,'^^^ t  64  -^^^^^^^^ 
Separate  wires,  the  frame  is  covered  with  fine  wire  cloth,  containing  ftom  f  t«  ^^  f^s 
per  inch  square.  Upon  both  moulds  a  deckel,  or  moveable  raised  edge-frame,  i^  used , 
which  must  fit  very  neatly,  otherwise  the  edges  of  the  paper  will  »>e  r«"f  • 

A  pair  of  moulds  being  laid  upon  the  bridge,  the  workman  puts  on  the  deckel,  brm^ 
the  m'Luld  into  a  vertical  position,  dips  it  about  half  way  down  into  the  ^tuff  before  lu^^^ 
then  turning  it  into  a  horizontal  position,  covers  the  mould  with  the  ^l^f^^^J^^^^^'^ 
ffentlv  This  is  a  very  delicate  operation  ;  for  if  the  mould  be  not  held  perfectl}  level, 
Se  part  of  the  sheet  will  be  thicker  than  another.     The  sheet  thus  formed  has  however 

SSeSherence;  so  that  by  turning  the  mould,  and  ^^^^-^''^'^^^^Z^T.ZtZ^^^^ 
vat,  it  is  affaii  reduced  to  pulp  if  necessary.  He  now  pushes  the  mould  ^^n§  the  smaU 
board  to  the  left,  and  removes  the  deckel.  Here  another  ^o^-k/nan  called  the  c^uc^^ 
receives  it,  and  places  it  at  rest  upon  the  ass,  to  dram  off  some  of  the  water  MeanwhUe 
the  vat-man  puis  the  deckel  upon  the  other  mould,  and  makes  another  s^^et.  The 
coucher  stands  to  the  left  side  of  the  vat,  with  his  face  towards  the  vat-man  pr  maker^ 
on  his  right  is  the  press  furnished  with  felt  cloths,  or  porous  flannels ;  a  t»iree-inch  thick 
plank  lies  before  him  on  the  ground.  On  this  he  lays  a  cushion  of  ^^^ts,  ««f.  ^^^^^J^ 
knotherfelt;  he  then  turns  the  paper  wire  mould,  and  presses  it  upon  the  felt,  where 
the  sheet  remains.  He  now  returns  the  mould  by  pushing  it  along  the  bridge^ 
The  maker  has  by  this  time  another  sheet  ready  for  the  coucher  ;  which  like  the  pre- 
ceding, is  laid  upon  the  ass,  and  then  couched  or  inverted  upon  another  felt,  laid  down  lor 

^^'in^thiTway,  felts  and  paper  are  alternately  stratified,  till  a  heap  of  six  or  eight  qnirw 
is  foime.l,  which  is  from  15  to  18  inches  hi-h.  This  mass  is  drawn  into  the  pre^,  and 
exposed  to  a  force  of  100  tons  or  upwards.  After  it  is  sufficiently  compressed,  the 
machine  i«s  relaxed,  and  the  elasticity  of  the  flannel  makes  the  rammer  descend  (if  a  hy- 
draulic press  be  used)  with  considerable  rapidity.  The  felts  are  then  drawn  out  on  the 
other  side  by  an  operative  called  a  layer,  who  places  each  felt  in  succession  upon  one 
board,  and  ea:h  sheet  of  paper  upon  another.  The  coucher  takes  immediate  possession 
of  the  fells  for  his  further  operations.  ,        v     *c        o  ..oo^«  in  10 

Two  men  at  a  vat,  and  a  boy  as  a  layer  or  lifter,  can  make  about  6  or  8  reams  in  lu 
hours  In  the  evening  the  whole  paper  made  during  the  day  is  put  into  another  press, 
and  subjectAd  to  moderate  compression,  in  order  to  get  quit  of  the  mark  of  the  leli,  ana 
more  of  the  water.  Next  day  it  is  all  separated,  a  process  called  parting,  and  being  again 
pressed,  is  carried  into  the  loft.  Fine  papers  are  often  twice  parted  and  pressed,  m  order 
to  eive  them  a  proper  surface.  ^  „  ii»^« 

The  next  operation  is  the  drying,  which  is  performed  in  the  foUowing  way.    Posts 


^■i!  f 


:1 


332 


PAPER-MAKING  MACHINE. 


about  10  or  12  feet  hieh  are  erected  at  iHp  H.c»o««^    r  .      ^ 

pierced  with  holes  six  inches  apar  ftwo  spars  w^thr^n  *~/«^^'^^«  ^^^  o«>er,  and 
the  distance  of  5  inches  from  one  ai^VcTed  alb^^^^^^  between  them,  at 

feet  high  between  these  posts,  supported  bv  pins  nn.h^  ?r  tnbbj  ^  placed  about  5 
The  workman  takes  up  4^8  sheKnaDera^Ti.K"^''  ^^^  ^""^^^  ^  ^^^  P«sts. 
the  form  of  a  T;  pas4g  this  T  betwLn  tKSlTsMr.il'P^^u"  *  ^'^^^  *^^  ^^  « 
proceeds  thus  till  all  the  ropes  are  fu^  He  then^'iilJhf 't  m  '^^'?  "P*^"  '^^"^^  "»<» 
Its  place,  which  he  fills  and  raises  L  liki  manner  N  op  nr  f  ^'^^b  ^""^  P"»«  «"«ther  in 
set  of  posts.     The  sides  of  ihedryhig^^Zha^^^^  '''^^^'  f'^  PJ«<^«i  in  every 

any  angle  at  pleasure.  ^  P"'^^^  shutters,  which  can  be  opened  to 

is  ^d^V' -e^eroT^^^^^  ^f,  »r^  -  heaps  to  be  sized.    Size 

other  matter  containing  much  Jitinp      THpS       u?  **""^"-  ^'  ^'^^ep's  feet,  or  any 

jdly ;  to  which,  when"strr4  itmX  Jnt  y  of  aCls" a^ed^^'^ie  ""  T'^'  l^  ^ 
takes  about  4  quires  of  paoer  snreads  ihpm  nnV  ;„  tki  •  added,  ihe  workman  then 
taking  care  that  they  be^XllSene^^^  Th  s  is  ratheTar^'"^^  '^^'"^^^  ^'^^^  ^^^^'^ 
fluous  size  is  then  Pressed'out,'andirp;per'^?  ^ar "J"  nto  s^^^^^^^  3'^^"^^'" 

more  pressed,  it  is  transferred  to  the  dry  no.room  hi,t  mnct  «  ?  I"  f"-/  ^'"^  «n<^« 
Three  days  are  required  for  this  vur^J    Whl^ThL  •  ^  v"*"^  ^  "^""^  ^^o  ^u'ekly. 

to  the  finishing-h^use,  and^  agah^^^^el^ed  It'y  iard'%' i^f  th  "'""^f  l!,  1!-^'  ^'  »^  ^""«» 
•mall  knives,  in  order  to  take  out  thp  S^       J  .    V'^  ^**^"  ^'^^^d  by  women  with 

Ihese  reams  are  comoressed  tied  nn  nnH  coot  *^tu  ^""'"««  "»io  reams,  and  done  up, 
can  count  200  reams,  orT^SoJ)  sheeK  a  L J  ^""'''"'^  '"'  '°^'-    ^  ^^«^  ^"^''"^^ 

boa^r3l,XZJ^;aTd"ttwLn'^^^^^^^  ^^^L^^^  ^^^^^^  P-*- 

ju^ecting  the  pilJ'to  the  ^es.^^"T^- rmu^i^^at:  tZt  ^^j^^^ 

orltn^rilffibK^ott'ei^^^^^^^^  ^^^^  -  too  much  used, 

differently  raised,  and  that  on  whicM^^^^^^  two  sides  of  the  felt  are' 

are  laid  down.    As  the  felts  have  to  ZliTZ  1%      .S'^  «  applied  to  the  sheets  which 
should  be  made  stoutf  ^long  combed  ^^^^^  warp 

should  be  of  carded  wiol  and  sniTintn  7^A  !u       ,  "  *^'^*^-      ^he  woof,  however, 
and  capable  of  imblbrng  iuch  water         *  '""  '^'^^'  ^  *^^  '^  '^"^"  '^^  ^-^^^^  ^Pon^: 

T^i^Z^^^^^  r  •*«  <^i  paper  by  hand,  has  fo, 

duces  it  in  a  continuous  sheetTf  inS  teTnatrw V^?^"'S  ^^^  a  machine  which  pro- 
sizes,  by  the  PAPEK^xTTrLrMACHiNE  °  ''^  ''  afterwards  cut  into  suitable 

triv^edTL^iTi^niftot?;;^^^^^^^^^^  r/a'cT'^  ^'  ^^^^""^  -  ^--'  -- 

it  a  patent  for  15  years,  wiS  a  sum  of  8000  ?Sn  l  r  *^°"  i""?,"^  "?»««>  ^nd  obtained  for 
ward  for  his  ingenuity. '  The  spSS^catio^of  iTlflT  '^^  .^f^"!?  ?<>^ernment,  as  a  re- 
of  Brevets  rf'  lyfventum  exvirl  MT^^^rV a  .  '11^"^'?  Published  in  the  second  volume 
Robert's  machine  ZS  fof^mOf^l'\'^Z  ^^^.^^  ^he  said  works,  bought 

insUtut"ed"  a'laJ^;u^;  a'it  e  o^Trfd'ltst!;^^      ht  ^'l^^f  r  *^.  ""^"^^^  ^^^  ^a«« 

June,  1810.      Didot  then  sent  ovpr  {Tpf?    .k     S  '  P*^^"'  ^^  "  decision  dated  23d 

which  contained  Te  specificat^^^^^^  Repertory  of  Arts,  for  Sept.   1808, 

secure  the  improved  Machine    3e'^^^^^  T^  instructions  to  a  friend  to 

obtained,  but  became  inopemtive  In  c^iou^ncJ  ^f^f  ff l^"^'.     '^^^  P"*^"*  ^^ 

France,  as  he  had  promiJS  so  as  to  mo^t Thp  n5    f'  ^^  u?'^*'^  '^"^"^  *«  'etum  to 

required  by  the  French Tatent  law.      It  was  not  IS    m^Tv.  T'it' V'^  ^^«  ^^^^ 

maker  at  Paris,  constructed  the  n«npr  ,LTrot      \  ^^^S.that  M.  Calla,  machine- 

Fourdrinier's,  and  whS  ^  the  l^nhlu^Tf^'  n- ^^  "^.   ^"^'^"^  ^^  ^^e  name  of 

imperfect  in  comparS' of  «n  Pn.r  i,  ^  I  *^  ^ichannaire  Techvolo^ique,  was  very 

France.    La  c<Zt^^^tZ^!l'^l^^^^^^  ^T7^  about  that' time  inS 

made  in  1829,  for  his  countn-mpn  »vt  thl  1  .k  i^^C"",'  I'  ^^^  Pa*"^"^  acknowledgment 
national  work.  If  Ihere  b^Sin/dfffi.^lt  '''tf  '^^  '^^^'^'^  ""'''^^^^  V^v^XerW  in  that 
French  mechanicians  oulhUoXi^L^^^^^  '^^'^  '"«<^^'"^«'  ^h« 

ply  of  them  in  England ;  ?or  the  printi^^^^  to  seek  the  sole  sup. 

Montffolfier,  Thomas  Varenne  pfrm^n  nSTnT      u"  France,  as  those  of  MM.  Cansom 
With  English-made  machi^^'         ""  Didot,  Delcambre,  De  Maupeon,  &c.,  are  mountS 


. 


PAPER-MAKING  MACHINE. 


333 


The  following,  for  example,  are  a  few  of  the  paper-mills  in  France  which  are  mounted 
with  the  self-acting  machines  of  Messrs.  Bryan  Donkin  &  Uo. 
Messrs.  Canson,  at  Annonay. 
M.  de  la  Place,  at  Jean  d'Heures,  Bar-le-duc. 
Societe  anonyme,  at  Sainte  Marie,  under  M.  Delatouche 
Echarcon  prcs  Mennecy,  (Seine  et  Oise). 
Firmin  Didot,  Mesnil  sur  I'Estree. 

M.  F.  M.  Montwlfier,  a  Annonay.        „  r».     ^ 

MuUer,  Bouchard,  Ondin  and  Go's.,  at  Gueures,  near  Dieppe. 
MM.  Richard  et  Comp.  a  Plainfoing. 
M.  Callot-Bellisle ;  Vieuze  et  Chantoiseau. 

Jfaes""::? tr«  ^::Z%l^:^rtZT^o.  «f  EaglUh  >neehanisa.  ,h..  .h. 
It  deserves  parucaianyio  ^  ,     received  gold  medals  at  the  last  ejposi- 

ra'';f  thr'plpen"  t  Z  LouvCaad  all  the  res,  received  medals  either  of  sUver  o, 

""The  following  is  a  true  narrative  of  the  rise  and  progress  of  the  paper  automaton. 
M  LeirDidJt,  aeeompanied  by  Mr.  John  Gamble,  an  EnsUshman  ,vho  had  resded 
M.  L,e-er  uiuoi,  "^^,.  '^„i,,|„^'  „ermis«ion  from  the  French  government,  m  1800,  to 
for  several  years  m  P»"^.  »^'»^^  „Kbert  "  continuous  machi«,  with  the  view  of  geU 
S,7thr^iefit  of  Ksl^^.\X  and  meehanicri  skill  to  bring  it  into  an  op«a..ve  su..« 
ting  the  benent  f'  P;"'"'  J;  ,  r  ,^^  vigorous  development  of  this  embrjo  project, 
ICh'tlZved  an  atoSntn  France,  they  addressed  themselves,  on  the  one  hand^u> 
:™lTrm'e;:at  opulent  and  public  spi^Hed  and  on  ^e^-J^e.'o  -.-.  di. 

jinguished  for  pe-verh^ -JX^^^^  ctrtaS'  iCprovrnis  upoi. 

HH£"^.^fa5h^5at«  o?«tlt  t  i*tjrn^?a.r^';r'u;o- 

%re'p™prre*!S*"showed  good  reasons,  ia  the  enormous  «pense  of  their  experiment^ 
•nd  theTajrnaUmportancf  of  the  object,  why  ^^Pa'cnt  should  h*ve  been  «^endl" 
years  from  the  latter  date,  and  would  have  obtained  juf^e  from  P""^*^*"*  "J.'^','  "^J^^ 
hnt  fnr  an  unvTorthv  artifice  of  Lord  Lauderdale  in  the  House  o(  J^ords.        ne,  ana  nn 

"We  will  give  seven  years,  and  Mr.  Fourdnni^  may  app  y  a^^^^^^^  ^^^^^^^^ 

S!  .Wp  in  the  natent  to  which  he  was  entitled  under  the  act  of  parliament. 

mrtfoid  in^K^^^^^^  long  conspicuous  as  the  seat  of  a  good  manufactory 

of  wer  and  paper  moSSs,  was  selecteS  by  the  proprietors  of  the  patent  as  the  fit  est 
nW  for  realizin-  their  plans ;  and  happily  for  them  it  possessed,  in  Mr.  HaU's  engineer- 
KstSS  every  tool  equisite  for  constructing  the  novel  automaton,  and  m  his 
^4tanrMr  B«?an  Donkin,  "young  and  zealous  mechanist,  who  combining  pm.ision 
;?workmanship^with  fertilit;  of  invention,  could  turn  ^^^  l°f  ^-.^I^^^i^^^^^ 
account.  To  this  gentleman,  aided  by  the  generous  ?«"fif.^^;y^^^j"^^S;i„^^^ 
the  dory  of  rearing  to  a  stately  manhood  the  helpless  bantling  of  M.  L.  Didot  »s  entirely 
due  i^  ml  aft?r  nearly  three  years  of  intense  application,  he  prc^uced  a  self-acting 
aS^hine  for  making  an  endless  web  of  paper,  which  was  erected  at  St,  Neot's  under  the 
S^eri^tende^:e  of  Mr.  Gamble,  and  performed  in  such  a  manner  as  to  surprise  every 

^'l^ncrihat  important  era  Mr.  Donkin  has  steadily  devoted  his  whole  mind  and  meant 

.  Rapport  de  Urj  Centr.1,  par  M.  Le  Baron  Cl»«le»  Djjpin  v^^^^  ^^^^  ,^,  ^^  p^ 

t  See  thit  shabby  piece  of  diplomacy  unveiled  in  the  Minutes  otEviacnnc  w^ 
nittM  of  the  House  of  Commons  on  Fourdnmer's  patent ;  Ma> ,  IM/. 


K. 


?f 


■m^' 


334 


PAPER-MAKING  MACHINE. 


to  the  progressive  improvement  of  this  admirable  annamtiic .  ««.i  »,-«  v   ♦!.        i    . 
--cularity,  precision,  promptitude,  and  vr^Zctivenes^^^! '     v   ^»«»  ^J  t^^  unfailmf 
place  along  with  wif,  W^gewo^dTand^^kwS^^^^^^  ^^S  ^^^'^  • 

"La  France"  says  a  late  official  eu]ZiJnfhL^     ?     ^^  ^  of  mechanical  fame. 

ments,  «ne  craint  p^lus  la  r  vali^  des  au  rl'luplernoTA^^^^^^  '"''V'^'T  ^^  ^''  ''""^ 
de  papiers  et  de  cartons  «•     A ftlr  t k:.  i      r^^^^  P*Vi  ^^  fabrication  des  divers  genres 

diafe.'   co„f:^'=rhTr,823l!Jrer.^Ss:ssTo"^^^  W" 

con/e„u,  containing  one  of  the  Fourdrinier  machines  made  a^  tIh     I    JJ  of  the  ^a;n«- 

papers  possess  many  advantages :  they  can  receive,  so  to  s^erunlirnhJ^H'"'""*'^^ 
they  preserve  a  perfectly  uniform  thickness  throughout  alfthdrlSthPv""''''"^ 
fabricated  m  every  season  of  the  year ;  nor  do  they  require  to  be  S!^'  ,  •  ^  °!f  ^  ^ 

by  M.  Delalouche  »  aPPa^atus  of  Mr.  Donkin,  recenUy  imported  from  England 

they  encounter  in  bringing   he  m^hlner^  to   tfthpn  ?       ^^'T\  ^  ""^"^^  <lifficulties  did 

A  MACHINE. 


Total  9 


Journeymen 
2  Ditto  . 
2  Finishers     , 
2  Dry  workers 

Parters  (none) 

Fire  (none) 

Felting 

Washing,  ditto 

Wire 

1  Man,  to  keep  in  repair  the  mill  > 
and  machine    ,        ,  I 


Expense  of  7  vats  per  annum  (see  next  page)  is 
A  machine  doing  7  vats'  work,  is,  per  annSn    . 

Balance  saved  by  the  machine  per  annum  . 


.£1,870    0    0 


'^£^^^^rzr;:^z:^::s^:^^-^^^^v.r^^^^^uc. 


D:AT.x^<!i?S!„t'is^X's?^?/i';ns'?„';^^^^^  b^  c^u. 


PAPER-MAKING  MACHINE.' 


Stt 


SEVEN  VATS 

• 

Day. 

Week. 

Month 

Year. 

8. 

d. 

£     8.    d. 

£  8.  d. 

£      8,     d. 

7  Vatmen,  at     -       -       -       - 

3 

3 

6  16    6 

27    6  0 

354  18    0 

7  Couchers        -        -        -        - 

3 

1 

6    9    6 

25  18  0 

336  14    0 

7  Layers             -        -        -        - 

3 

1 

6    9    6 

25  18  0 

336  14    0 

3  Finishers        -        -        -        - 

4 

0 

3  12    U 

14    8  0 

187    4    0 

6  Dry  workers   -        -        -        - 

3 

1 

5  11    0 

22    4  0 

288  12    0 

3  Men  to  go  to  press,  &c.  - 

2 

6 

2    5    0 

9    0  0 

117    0    0 

7  Parters  (women)     -        -        - 
Fire 

1 

4 

2  16    0 
7    0    0 

11     4  0 
28    0  0 

145  12    0 
364    0    0 

Felting 

140    0    0 

Washing  ditto,  oil,  soap,  fire,  &c. 

1  11     6 

6    6  0 

81  18    0 

Moulds  -        -        -        -        - 

140    0    0 

1  Man,  and  expenses  of  repairing,  ^ 

in  keeping  in  order  7  vats,  vat-  > 

112    0    0 

presses,  &c.                                     ) 
Total  41  persons. 

42  11     0 

170    4  o'2,604     0    0  ] 

In  the  same  statement,  it  was  shown  that  the  expense  of  making  paper  by  hand  is  16». 
per  cwt  whereas  by  their  machine  it  is  pnly  3».  9(i. ;  so  that  upon  432,000  cwts.  the 
Quantity'annually  made  in  Great  Britain  and  Ireland  (as  founded  upon  the  fact  that  one 
vat  can  make  480  cwts.  of  paper,  and  that  there  were  900  vats  m  the  kingdom),  the 
annual  saving  by  the  machine  would  be  264,600/.,  or  345,600/.  —  81,000/. 

In  a  second  statement  laid  before  the  pubUc  in  1807,  the  patentees  observe  that  their 
recently  improved  machine,  from  its  greater  simplicity,  may  be  erected  at  a  considerably 
reduced  expense.  «  Mr.  Donkin,  the  engineer,  will  engage  to  furnish  machines  of  the 
dimensions  specified  below,  with  all  the  present  improvements,  at  the  prices  specified 
below. 


Inches. 

If  driven  by  atraps. 

£ 

3  or  4  vats         -       -       •       - 

6  ditto         .       -       -       - 

8  ditto        -       -       -       - 

12  ditto        -       .       -       - 

3  or  4  vats         .        -       -       . 

6  ditto        .       -       -       - 

8  ditto        -        -       -       - 

12  ditto        -        -        -        - 

30 
40 
44 
54 

30 
40 
44 
54 

between  the  deckles 
ditto               ditto 
ditto               ditto 
ditto               ditto 

Ifdriven  by  wheels. 

between  the  deckles 
ditto               ditto 
ditto               ditto 
ditto               ditto 

715 
845 
940 
995 

750 

880 

980 

1,040 

« Instead  of  5  men,  formerly  employed  upon  1  machine,  3  are  now  (in  1813)  fully 
safficient,  without  requiring  that  degree  of  attention  and  skill  which  was  formerly  indis- 
pensable. 

« In  1806  the  machine  was  capable  of  doing  the  work  of  6  vats  in  twelve  hours ;  it 
is,  however,  now  capable  of  doing  double  that  quantity,  at  one  fourth  of  the  expense. 
For  by  the  various  improvements  enumerated  above,  the  consumption  of  wire  is  reduced 
nearly  one  half,  and  lasts  above  double  the  time ;  the  quantity  of  paper  produced  is 
doubled ;  and,  taking  into  consideration  the  work  which  is  now  performed  by  the  men 
over  and  above  their  immediate  attendance  upon  the  machine,  it  may  be  fairly  stated,  that 
the  number  of  men  is  reduced  to  one  half;  consequently  the  expense  of  wire  and  labor 
is  reduced  to  one  fourth  of  what  it  was. 

«  The  other  advantages  incidental  to  the  nature  of  the  process  of  making  paper  by  this 
machine,  may  be  classed  in  the  following  order : — 

"  1st.  That  the  paper  is  much  superior  in  strength,  firmness,  and  appearance,  to  any 
which  can  be  made  by  hand  of  the  same  material. 

**  2d.  It  requires  less  drying,  less  pressing  and  parting,  and  consequently  comes  sooner 
to  market ;  for  it  receives  a  much  harder  pressure  from  the  machine  than  can  possibly 
be  given  by  any  vat  press,  and  is  therefore  not  only  drier,  but,  on  account  of  the  close- 
ness and  firmness  of  texture,  even  the  moisture  which  remains  is  far  sooner  evaporated, 
on  exposure  to  the  air,  than  it  would  be  from  the  more  spongy  or  bibulous  paper  made 
by  hand. 


336 


PAPER-MAKING  MACHINE. 


PAPER-MAKING  MACHINE. 


337 


1 


"The  superior  pressure,  and  the  circumstance  of  one  side  of  the  paper  passing  undei 
the  polished  surface  of  one  of  the  pressing  rollers,  contribute  to  that  smoothness  which 
m  hand-made  papers  can  only  be  obtained  by  repeated  parting  and  pressing ;  consequent!; 
a  great  part  of  the  time  necessarily  spent  in  these  operations  is  saved,  and  the  papet 
sooner  finished  and  ready  for  market. 

"  3dly.  The  quantity  of  broken  paper  and  retree  is  almost  nothing  compared  with  what 
is  made  at  the  vats. 

"  4th.  The  machine  makes  paper  with  cold  water. 

"  5th.  It  is  durable,  and  little  subject  to  be  out  of  repair.  The  machine  at  Two  Waters, 
in  Hertfordshire,  for  the  last  three  years,  has  not  cost  10/.  a  year  in  repairs. 

"  6th.  As  paper  mills  are  almost  universally  wrought  by  streams,  which  vary  con- 
siderably in  their  power  from  time  to  time,  there  will  result  from  this  circumstance  a 
very  important  advantage  in  the  adoption  of  the  machine.  The  common  paper  mill 
being  limited  by  its  number  of  vats,  no  advantage  can  be  taken  of  the  frequent  accessions 
of  power  which  generally  happen  in  the  course  of  the  year ;  but,  on  the  contrary,  as 
scarcely  any  mills  are  capable  of  preparing  stuff  for  twelve  vats,  every  accession  of  power 
to  the  mill,  where  a  machine  is  employed,  will  increase  its  produce  without  any  additional 
expense. 

"  7th.  The  manufacturer  can  suspend  or  resume  his  work  at  pleasure ;  and  he  is  be- 
sides effectually  relieved  from  the  perplexing  difficulties  and  loss  consequent  upon  the 
perpetual  combinations  for  the  increase  of  wages." 

It  is  a  lamentable  fact,  that  the  attention  required  to  mature  this  valuable  invention, 
and  the  large  capital  which  it  absorbed,  led  ultimately  to  the  bankruptcy  of  this  opulent 
and  public-spirited  company ;  after  which  disaster  no  patent  dues  were  collected,  though 
twelve  suits  in  Chancery  were  instituted ;  these  being  mostly  unsuccessful,  on  account 
of  some  paltry  technical  objections  made  to  their  well-specified  patent,  by  that  un- 
scientific judge  Lord  Tenterden.  The  piratical  tricks  practised  by  many  considerable 
paper-makers  against  the  patentees  are  humiliating  to  human  nature  in  a  civilized  and 
toi-disarU  Christian  community.  Many  of  them  have  owned,  since  the  bankruptcy  of 
the  house  removed  the  fear  of  prosecution,  that  they  owed  them  from  2000/.  to  3000i. 
apiece. 

Nothing  can  place  the  advantage  of  the  Fourdrinier  machine  in  a  stronger  point  of 
view,  than  the  fact  of  there  being  280  of  them  now  at  work  in  the  United  Kingdom, 
making  collectively  1600  mQes  of  paper,  of  from  4  to  5  feet  broad,  every  day ;  that  they 
have  lowered  the  price  of  paper  50  per  cent.,  and  that  they  have  increased  the  revenue, 
directly  and  indirectly,  by  a  sum  of  probably  400,000/.  per  annum.  The  tissue  paper 
made  by  the  machine  is  particularly  useful  for  communicating  engraved  impressions  to 
pottery  ware ;  before  the  introduction  of  which  there  was  but  a  miserable  substitute. 
Messrs.  R.  and  J.  Clewes,  of  Cobridge  potteries,  in  a  letter  to  Messrs.  Fourdrinier,  state, 
**  that  had  not  an  improvement  taken  place  in  the  manufacture  of  paper,  the  new  style 
of  engraving  would  have  been  of  no  use,  as  the  paper  previously  used  was  of  too  coarse 
a  nature  to  draw  from  the  fair  engravings  any  thing  like  a  clear  or  perfect  impression ; 
and  the  Staffordshire  potteries,  in  our  opinion,  as  well  as  the  public  at  large,  are  deeply 
indebted  to  you  for  the  astonishing  improvement  that  has  recently  taken  place,  both  as 
regards  china  and  earthenware,  more  particularly  the  latter."  The  following  rates  of 
prices  justify  the  above  statement  >— 

1814.  1822.  1833. 

9»    d,  9,    d,  9.    d. 

Demy  pottery  tissue       •-•-120  96  70 

Royal  ------    16    3  12    0  89 

«  We  have  adopted  a  new  mode  of  printing  on  china  and  earthenware,  which,  but  for 
your  improved  system  of  making  tissue  paper,  must  have  utterly  failed ;  our  patent  ma- 
ehlne  requiring  the  paper  in  such  lengths  as  were  impossible  to  make  on  the  old  plan. 
On  referring  to  our  present  stock,  we  find  we  have  one  sheet  of  your  paper  more  than 
1200  yards  long.    Signed,  Machin  and  Potts ;  Burslem,  February  25th,  1834." 

I  have  had  the  pleasure  of  visiting  more  than  once  the  mechanical  workshops  of 
Messrs.  Bryan  Donkin  and  Co.  in  Bermondscy,  and  have  never  witnessed  a  more 
admirable  assortment  of  exquisite  and  expensive  tools,  each  adapted  to  perform  its  part 
with  despatch  and  mathematical  exactness,  though  I  have  seen  probably  the  best 
machine  factories  of  this  country  and  the  Continent.  The  man  of  science  will  appreciate 
this  statement,  and  may  perhaps  be  surprised  to  learn  that  the  grand  mural  circle  of 
7  feet  diameter,  made  by  Troughton,  for  the  Royal  Observatory  of  Greenwich,  was  turned 
with  final  truth  upon  a  noble  lathe  in  the  said  establishment.  It  has  supplied  no  fewer 
than  133  complete  automatic  paper  machines,  each  of  a  value  of  from  1200/.  to  2000/., 
to  different  manufactories,  not  only  in  the  United  King(fom,  but  in  all  parts  of  the 
civilized  world  j  as  mentioned  in  the  second  paragraph  of  the  present  article.    Each 


^a 


»J 


00 
CO 


t* 


tQl 


»« 


machine  is  capable  of  making,  under  the  impulsion  of  anf 
prime  mover,  all  unwatched  by  a  human  eye,  and  unguided  by 
a  human  hand,  from  20  to  50  feet  in  length,  by  5  feet  broad, 
of  most  equable  paper  in  one  minute.  Of  paper  of  average 
thickness,  it  turns  off  30  feet. 

Fi^.\0?>9>  is  an  upright  longitudinal  section,  representing  the 
j  machine  in  its  most  complete  state,  including  the  drying  steam 
I  cylinders,  and  the  compound  channelled  rollers  of  Mr.  Wilks, 
I  subsequently  to  be  described  in  detail.  The  figure  in  the  upper 
[line  shows  it  all  in  train,  when  the  paper  is  to  be  wound  up 
i  wet  upon  the  reels  e,  e,  which  being  moveable  round  the  centre 
U  of  a  swing-bar,  are  presented  empty,  time  about,  to  receive 
(the  tender  web.  The  figure  in  the  under  line  contains  the 
I  steam  or  drying  cylinders;  the  points  o  o,  of  whose  frame^ 


*B 


j  replace,  at  the  points  p,  p,  the  wet  reel  frame,  f  f,  p. 
A  is  the  vat,  or  receiver  of  pulp  from  the  stuff-chest. 

B  is  the  knot  strainei*  of 
Ibotson  (p.  841.),  to  cleai  the 
pulp  before  passing  on  to  the 
wire. 

G  is  the  hog,  or  agitator  in 
the  vat.  The  arrows  show 
the  course  of  the  currents  at 
the  pulp  in  the  vat. 

I  is  the  apron,  or  receiver 
of  the  water  and  pulp  which 
escape  through  the  endless 
wire,  and  which  are  returned 
by  a  scoop-wheel  into  the  vat. 

b  is  the  copper  lip  of  the  vat, 
over  which  the  pulp  flows  to 
the  endless  wire,  on  a  leathern 
apron  extending  from  this  lip 
to  about  nine  inches  over  the 
wire,  to  support  the  pulp  and 
prevent  its  escaping. 

c,  c  are  the  bairs  which  beai 
up  the  small  tube  rollers  that 
support  the  wire. 

d,  d  are  ruler  bars  to  suppoit 
the  copper  rollers  over  whicA 
the  wire  revolves. 

K  is  the  breast  roller,  round 

which  the  endless  wire  turns. 

N  is  the  point  where  the 

shaking  motion  is  given  to  tte 

machine. 

M  is  the  guide  roller,  having 
its  pivots  moveable  laterally 
to  adjust  the  wire  and  keep  it 
O  parallel. 
I.  is  the  pulp  roller,  or,  **  dandy,"  to  press  out  water,  and  to 
set  the  paper,  r,  is  the  place  of  the  second,  when  it  is  used. 
H  is  the  first  or  wet  press,  or  couching  rollers ;  the  wire 
leaves  the  paper  here,  which  latter  is  couched  upon  the 
endless  felt  p;  and  the  endless  wire  o  returns,  passing 
round  the  lower  couch  roller.  By  Mr.  Donkin's  happy  inven- 
tion of  placing  these  rollers  obliquely,  the  water  runs  freely 
away,  which  it  did  not  do  when  their  axes  were  in  a  vertical 
line. 

e,  e  are  the  deckles,  which  form  the  edges  of  the  sheet  of 
I  paper,  and  prevent  the  pulp  passing  away  laterally.     They 
regulate  the  width  of  the  endless  sheet. 
/,/are  the  revolving  deckle  straps. 
R  is  the  deckle  guide,  or  driving-pulley. 
^    g,  g  are  tube  rollers,  over  which  the  wire  passes,  which  da- 
mot  partake  of  the  shaking  motion ;  and. 


"WB-as 


338 


PAPER-MAKING  MACHINE. 


PAPER-MAKING  MACHINE. 


339 


A,  h  are  moveable  rollers  for  stretching  the  wire,  or  orass  carriages  for  keeping  t]l« 
rollers  g,  g  m  a  proper  position.  ^  ^y^'s  »-'■ 

c  is  the  second  press,  or  dry  press,  to  expel  the  water  in  a  cold  state 
shfet""'  *"*"*'  *"  ^*  ""'^^  °^  '^^  ^''^^''  ""^'  ^^  ^^^  '*^*^  cylinders  for  drying  the  endless 
t,  i  are  rollers  to  convey  the  paper. 

JdZV^^'^o^-I^To^L^: ''''■•  *""*  — o»«PP«rt  a.,  paper.  „d  prevent  i. 

D,  D  are  the  hexagonal  expanding  reels  for  the  steam-dried  paper  web,  one  onlv  beins 
ised  at  a  time,  and  made  to  suit  different  sizes  of  sheets.    I  is  their  swing  fulc^Sm 

F,  r,  F,  F,  IS  the  frame  of  the  machine.  ^  luicrum. 

The  deckle  straps  are  worthy  of  particular  notice  in  this  beautiful  machine  Ther 
are  composed  of  many  layers  of  cotton  tape,  each  one  inch  broad,  and  to?e*ther  one 
half  mch  thick,  cemented  with  caoutchouc,  so  as  to  be  at  once  perfectly  flexible  and 
water-tight.  «-  /  *v  »iiu 

The  upper  end  of  each  of  the  two  carriages  of  the  roller  l  is  of  a  forked  shape,  and 
the  pivots  of  the  roller  are  made  to  turn  in  the  cleft  of  the  forked  carriages  in  sih  a 
manner,  that  the  roller  may  be  prevented  from  having  any  lateral  motion,  while  it  possesses 
a  tree  vibratory  motion  upwards  and  downwards ;  the  whole  weight  of  the  roller  l  beine 
borne  by  the  endless  web  of  woven  wire.  * 

The  greatest  difficulty  formerly  experienced  in  the  paper  manufacture  upon  the 
continuous  system  of  Fourdnnier,  was  to  remove  the  moisture  from  the  pulp,  and  condense 
It  with  sufficient  rapidity,  so  as  to  prevent  its  becoming  what  is  caUed  water-galled,  and 
to  permit  the  web  to  proceed  directly  to  the  dn  ing  cylinders.  Hitherto  no  invention  has 
answered  so  weJl  m  practice  to  remove  this  difficulty  as  the  channelled  and  perforated 
pulp  rollers  or  dandies  of  Mr.  John  Wilks,  the  ingenious  partner  of  Mr.  Donkin;  for 
which  a  patent  was  obtained  m  1830.  Suppose  one  of  these  rollers  (see  l,  in  Jig  1038 
and  MM,  in  >g  1043)  is  required  for  a  machine  which  is  to  make  paper  54  inches  wide. 
It  must  be  about  60  inches  long,  so  that  its  extremities  (seeyig«.1039andlO4O)mav  extend 
over  or  beyond  each  ^ge  of  the  sheet  of  paper  upon  which  it  is  laid.  I^d  ameter  may 
be  7  inches.  About  8  grooves,  each  l-16lh  of  an  inch  wide,  are  made  in  every  inch  of 
the  tube ;  and  they  are  cut  to  half  the  thickness  of  the  copper,  with  a  rSn  "ularly 
shaped  tool.  A  succession  of  ribs  and  grooves  are  thus  formed  throughout  the  whole 
length  of  the  tube.  A  similar  succession  is  then  made  across  the  former,  but  of  24  in 
the  inch  and  on  the  opposite  surface  of  the  metal,  which  by  a  peculiar  mode  of  manage- 
ment had  been  prepared  for  that  purpose.      As  the  latter  grooves  are  cut  as  deep  asThc 

r?u>  ^^^^^  ""V^^  "'''**^  ""^^^  ^^"^^  °"  '^^  ^"tside,  crossing  each  other  at  righ   angles 

and  thereby  producing  so  many  square  holes;  leaving  a  series  of  straight  copper  rib!  on 

he  interior  surface  of  the  said  tube,  traversed  by  another  series  of  ribs  coiled  round 

them  on  the  outside,  forming  a  cylindrical  sieve  made  of  one  piece  of  metal.    The 

rough  edges  of  all  the  ribs  must  be  rounded  off  with  a  smooth  file  into  a  semi-circular 

form.  Pig*.  1039,  and  1040.  a  a,  are  por- 
tions of  the  ribbed  copper  tube.  Fig,  1039 
shows  the  exterior,  and  Jig.  1040  the  in- 
terior surface ;  6,  b  and  6,  b  show  the  plain 
part  at  each  of  the  ends,  where  it  is  made 
fast  to  the  brass  rings  by  rivets  or  screws ; 
c,  c  are  the  rings  with  arms,  and  a  centre 
piece  in  each,  for  fixing  the  iron  pivot  or 
shaft  B ;  one  such  pivot  is  fixed  by  rivet- 
ing it  in  each  of  the  centre  pieces  of  the 
rings,  as  shown  at  c,  Jig.  1040 ;  so  that  both 
the  said  pieces  shall  be  concentric  with  the 
rings,  and  have  one  common  axis  with  each 
other,  and  with  the  roller.  At  a,  a,  a 
groove  is  turned  in  each  of  the  pivots,  for 
the  purpose  of  suspending  a  weight  by  a 
hook,  in  order  to  increase  the  pressure  up- 
on the  paper,  whenever  it  may  be  found 
necessary. 

Fig.  1041  is  an  end  view,  showing  the 
copper  tube  and  its  internal  ribs  a,  a  ;  the 
brass  rings  c,  c ;  arm  d,  d,  d  ;  centre  piece  e, 
and  pivot  b.  Fig.  1042  is  a  section  of  the 
said  ring,  with  the  arms,  &c. 

The  roller  is  shown  at  l.  Jig.  1038,  as 
lying  upon  the  surface  of  the  wire-web. 


The  relative  position  of  that  perforated  roller,  and  the  little  roUcr  6,  over  whid» 
it  lies,  is  such  that  the  axis  of  l  is  a  little  to  one  side  of  the  axis  of  6,  and  not  in  the 
same  vertical  plane,  the  latter  being  about  an  inch  nearer  the  vat  end.  Hence,  when- 
ever the  wire-web  is  set  in  progressive  motion,  it  wUl  cause  the  roller  l  to  revolve  upon 
its  surface ;  and  as  the  paper  is  progressively  made,  it  will  pass  onwards  with  the  web 
under  the  surface  of  the  roller.  Thus  the  pulpy  layer  of  paper  is  condensed  by 
compression  under  the  ribbed  roller;  whUe  it  transmits  its  moisture  through  the 
perforations,  it  becomes  sufficiently  compact  to  endure  the  action  of  the  wet  press 
rollers  h,  h,  and  also  acquires  the  appearance  of  parallel  hues,  as  if  made  by  hand  m  a 

1    'J  \A 

*  Mn  Wiis  occasionally  employs  a  second  perforated  roller  in  the  same  paper  machine, 
which  is  then  placed  at  the  dotted  lines  »,*»»-.  _,«     ♦•        r 

The  patentee  has  described  in  the  same  specification  a  most  ingenious  modification  of 
the  said  roller,  by  which  he  can  exhaust  the  air  from  a  hollowed  portion  of  its  periphery, 
and  cause  the  paper  in  its  passage  over  the  roller  to  undergo  the  sucking  operation  of 
the  partial  void,  so  as  to  be  remarkably  condensed ;  but  he  has  not  been  called  upon  to 
apply  this  second  invention,  in  consequence  of  the  perfect  success  which  he  has  experi- 
enced in  the  working  of  the  first. 

The  following  is  a  more  detailed  illustration  of  Mr.  Wilks'  improved  roller. 
Fie.  1043 represents  two  parts  of  his  double-cased  exhausting  cylinder. 

*  *^  This   consists  of   two   copper    tubes, 

one  nicely  lining  the  other;  thel  inner 
being  punched  full  of  round  holes,  as 
at  K,  K,  where  that  tube  is  shown  un- 
covered;   a   portion   of  the   inner   sur- 
face of  the    same    tube    is    shown  at 
L,  L.     In  this  figure  also,  two  portions 
of  the  outer  tube  are  shown  at  m,  m, 
and  N,  N  ;  the  former  being  an  external, 
and  the  latter  an  internal  view.     Here 
we  see  that  the  external  tube  is  the 
ribbed  perforated  one  already  described  ; 
the  holes  in  the  inner  tube  being  made 
in  rows  to  correspond  with  the  grooves 
in   the   outer.      The   holes   are   so   dis- 
tributed that  every  hole  in  one  row  shall 
be  opposite  to  the  middle  of  the  space 
left  between  two  holes  in  the  next  row, 
as  will  appear  from  inspection  of  the 
figure.      The  diameter  of  each  of  the 
punched  holes   somewhat    exceeds    the 
width  of  each  rib  in  the  inside  of  the 
outer  cylinder,  and  every  inside  groove 
of  this  tube  coincides  with  a  row  of 
holes  in  the  former,  which  construction 
permits  the  free  transudation  or  perco 
tetion  of  "the'' water  out  of  the  pulp.    At  each  end  of  this  double-case  cylinder,  a  part  is 
left  at  N,  N,  plain  without,  and  grooved  merely  in  the  mside  of  the  outer  tube     The 
smooth  surface  allows  the  brass  ends  to  be  securely  fixed ;  the  outer  edge  of  the  brass 
rine  fits  tight  into  the  inside  of  the  end  of  the  cylinders.  j.v. 

6u  the  inside  of  each  of  these  rings  there  are  four  pieces  which  project  towards  the 
centre  or  axis  of  the  cylinder;  two  of  which  pieces  are  shown  at  a,  a.  Jig,  104dm 
section.  6,  6,  is  a  brass  ring  with  four  arms  c,  c,  c,  c,  and  a  boss  or  centre  piece  d^  d. 
The  outer  edge  of  the  last-mentioned  ring  is  also  turned  cylindncal,  and  ot  such  » 
diameter  as  to  fit  the  interior  of  the  former  ring  o,  o.  The  two  rings  are  securely 
held  together  by  four  screws.  «,  c  is  the  hollow  iron  axle  or  shaft  upon  which  the 
cylinder  revolves.  Its  outside  is  made  truly  cylindrical,  so  as  to  fit  the  circular  holes 
in  the  bosses  d,  d,  of  the  rings  and  arms  at  each  end  of  the  cybnder.  Hence,  U  the 
hollow  shaft  be  so  fixed  that  it  will  not  turn,  the  perforated  cylinder  is  capable  of  having 
a  rotatory  motion  given  to  it  round  that  shaft.  This  motion  is  had  recourse  to,  when  the 
vacuum  apparatus  is  employed.  But  otherwise  the  cylinder  is  made  fast  to  the  hollow 
axle  by  means  of  two  screw  clamps.  To  one  end  of  the  cylinder,  as  at  p,  a  toothed  wheel 
is  attached,  for  communicating  a  rotatory  motion  to  it,  so  that  its  surface  motion  shaU  be 
the  same  as  that  of  the  paper  web;  otherwise  a  rubbing  motion  might  ensue,  which  would 

wear  and  injure  both.  ,        _r         r 

The  paper  stuff  or  pulp  is  allowed  to  flow  from  the  vat  A,  fig.  1038  on  to  the  surface  of 
the  endless  wire-web,  as  this  is  moving  along.    The  lines  o,  o,  fig.  1088  show  the  course  of 


340 


■  f  i 


''l\  ^B 

i 

1 

»i 

PAPER-PULP  STRAINER. 


the  motion  of  the  web,  which  operates  as  a  sieve,  separating  to  a  certain  de^ee  the  Wfttef 
from  the  pulp,  yet  leaving  the  latter  in  a  wet  state  till  it  arrives  at  the  first^pair  of  pres* 
ing  rollers  h,  h,  between  which  the  web  with  its  sheet  of  paper  is  squeezed.  Thick 
paper,  in  passing  through  these  rollers,  was  formerly  often  injured  by  becoming  water 
galled,  from  the  greater  retention  of  water  in  certain  places  than  in  others.  But  Messrs. 
Donkin's  cylinder,  as  above  described,  has  facilitated  vastly  the  discharge  of  the  water, 
and  enabled  the  manufacturer  to  turn  off  a  perfectly  uniform  smooth  paper. 

In  Jig.  788,  immediately  below  the  perforated  cylinder,  there  is  a  wooden  water- 
trough.  Along  one  side  of  the  trough  a  copper  pipe  is  laid,  of  the  same 
length  as  the  cylinder,  and  parallel  to  it;  the  distance  between  them  being  about 
one  fourth  of  an  inch.  The  side  of  the  pipe  facing  the  cylinder  is  perforated  with  a 
line  of  small  holes,  which  transmit  a  great  many  jets  of  water  against  the  surface  of  the 
cylinder,  in  order  to  wash  it  and  keep  it  clean  during  the  whole  continuance  of  the 
process. 

The  principle  adopted  by  John  Dickinson,  Esq.,  of  Nash  Mill,  for  making  paper, 
is  different  from  that  of  Fourdrinier  It  consists  in  causing  a  polished  hollow 
brass  cylinder,  perforated  with  holes  or  slits,  and  covered  with  wire  cloth,  to  revolve 
oyer  and  just  in  contact  with  the  prepared  pulp :  so  that  by  connecting  the  cylinder 
with  a  vessel  exhausted  of  its  air,  the  film  of  pulp,  which  adheres  to  the  cylinder 
during  its  rotation,  becomes  gently  pressed,  whereby  the  paper  is  supposed  to  be  ren- 
dered drier,  and  of  more  uniform  thickness,  than  upon  the  horizontal  hand  mOta^ds, 
or  travelling  wire  cloth  of  Fourdrinier.  When  subjected  merely  to  agitation,  the  water 
is  sucked  inwards  through  the  cylindric  cage,  leaving  the  textile  filaments  so  completely 
interwoven  as,  if  felted  among  each  other,  that  they  will  not  separate  without  breaking, 
and,  when  dry,  they  will  form  a  sheet  of  paper  of  a  strength  and  quality  relative  to  the 
nature  and  preparation  of  the  pulp.  The  roll  of  paper  thus  formed  upon  the  hollow 
cylinder  is  turned  off  continuously  upon  a  second  solid  one  covered  with  felt,  upon  which 
it  is  condensed  by  the  pressure  of  a  third  revolving  cylinder,  and  is  thence  delivered  to 
the  drying  rollers. 

Such  is  the  general  plan  of  Mr.  Dickinson's  paper  machines,  into  which  he  has  intro- 
duced numerous  improvements  since  its  invention  in  1809,  many  of  them  secured  by 
patent  right;  whereby  he  has  been  enabled  to  make  papers  of  first-rate  quality,  more  par- 
ticularly for  the  printing-press.     See  infrii. 

In  July,  1830,  Mr.  Ibotson  of  Poyle,  paper  manufacturer,  obtained  a  patent,  see  b,  Jig, 
788,  which  has  proved  very  successful,  for  a  peculiar  construction  of  a  sieve  or  strainer. 
Instead  of  wire  meshes,  he  uses  a  series  of  bars  of  gun-metal,  laid  in  the  bottom  of  a  box, 
very  closely  together,  so  that  the  upper  surfaces  or  the  fiat  sides  may  be  in  the  same  plane, 
the  edge  of  each  bar  being  parallel  with  its  neighbor,  leaving  parallel  slits  between  them 
of  from  about  l-70th  to  1-lOOth  of  an  inch  in  width,  according  to  the  fineness  or  coarseness 
of  the  paper-stuff*  to  be  strained.  As  this  stuff  is  known  to  consist  of  an  assemblage  of 
very  fine  flexible  fibres  of  hemp,  flax,  cotton,  &,c.,  mixed  with  water,  and  as,  even  in  the 
pulp  of  which  the  best  paper  is  made,  the  length  of  the  said  fibres  considerably  exceeds 
the  diameter  of  the  meshes  of  which  common  strainers  are  formed,  consequently  the  long- 
est and  most  useful  fibres  were  formerly  lost  to  the  paper  manufacturer.  Mr.  Ibotson's 
improved  sieve  is  employed  to  strain  the  paper-stuff  previously  to  its  being  used  in  the 
machine  above  described,  (see  its  place  at  b  in  the  vat.)  When  the  strainer  is  at  work, 
a  quick  vertical  and  lateral  jogging  motion  is  given  to  it.  by  machinery  similar  to  the  jig- 
ging screens  of  corn  mills. 

Since  the  lateral  shaking  motion  of  the  wire-web  in  the  Fourdrinier  machine,  as  origin- 
ally made,  was  injurious  to  the  fabric  of  the  paper,  by  bringing  its  fibies  more  closely 
together  breadthwise  than  lengthwise,  thus  tending  to  produce  long  ribs,  or  thick 
streaks  in  its  substance,  Mr.  Geoi^e  Dickinson,  of  Buckland  Mill,  near  Dover,  proposed, 
in  the  specification  of  a  patent  obtained  in  February,  1828,  to  give  a  rapid  up-and-down 
movement  to  the  travelling  web  of  pulp.  He  does  not,  however,  define  with  much  pre- 
cision any  proper  mechanism  for  effecting  this  purpose,  but  claims  every  plan  which 
may  answer  this  end.  He  proposes  generally  to  mount  the  rollers,  which  conduct  the 
horizontal  endless  web,  upon  a  vibrating  frame.  The  forepart  of  this  frame  is  attached 
to  the  standards  of  the  machine,  by  hinge  joints,  and  the  hinder  part,  or  that  upon 
which  the  pulp  is  first  poured  out,  is  supported  by  vertical  rods,  connected  with  a 
crank  on  a  shaft  below.  Rapid  rwtatory  motion  being  given  to  this  crank-shaft,  the 
hinder  part  of  the  frame  necessarily  receives  a  quick  up-and-down  vibratory  movement, 
which  causes  the  water  to  be  shaken  out  from  the  web  of  pulp,  and  thus  sets  the  fibres 
of  the  paper  with  much  greater  equality  than  in  the  machines  formerly  constructed.  A 
plan  similar  to  this  was  long  ago  introduced  into  Mr.  Donkin's  machines,  in  which  the 
vibrations  were  actuated  in  a  much  more  mechanical  way. 

John  Dickinson,  Esq.,  of  Nash  Mill,  obtained  a  patent  in  October,  1830,  for  a  method  of 
uniting  face  to  face  two  sheets  of  pulp  by  means  of  machinery,  in  order  to  prodace  paper 


1j 


PAPER-PULP  STRAINER. 


U 


of  extraordinary  thickness.  Two  vats  are  to  be  supplied  with  paper  stuff  as  «s"al ;  « 
whSh  two  hSlow  barrels  or  drums  are  made  to  revolve  upon  axles  dnven  by  any  fi«* 
moier;  an  endless  felt  is  conducted  by  guide  rollers,  and  brought  »»^t«  co°^ct^with  ^ 
drams'  the  first  drum  gives  off  the  sheet  of  paper  pulp  from  its  periphery  to  the  lelt, 
whkh  passing  over  a  pressing  roller,  is  conducted  by  the  felt  to  that  part  of  a  second 
Irum  whTcH  in  contact  with  another  pressing  roller.  A  similar  sheet  of  paper  pulp  is 
now  g^en  off  f  om  the  second  drum,  and  it  is  brought  into  contact  with  the  fo'^er  by  the 
w^sure  of  its  own  roller.  The  two  sheets  of  paper  pulp  thus  united  are  earned  forwarf 
byX  felt  overT  guide  roller,  and  onward  to  a  pair  of  pressing  rolers,  where  by  contact 
the  moUt  surfaces  of  the  pulp  are  made  to  adhere,  and  to  constitute  one  double  thick 
iLHf  pape  ,^^^^^^^  afte?  passing  over  the  surfaces  of  hollow  drums  heated  by  steam 
S;«™«  Arl\ni\  romnact  The  rotatory  movements  of  the  two  pulp-lifting  drums  must 
^brul  yt  sTm^utSut  buMhTof  theVssing  rollers  should  be  a  Uttle  faster,  b^use 
the  sheets  extend  by  the  pressure,  and  they  should  be  drawn  forward  as  fast  as  they  arc 
deliver^  otheiwise  creases  would  be  formed.  Upon  this  invention  is  founded  Mr  Dick- 
S.iigSs  method  of  making  safety-paper  for  Post-office  stamps,  by  mtroducmg 

'%^7X^ngl^^^nVo^^^^^  inventive  manufacturer  is  a  peculiaHy  elegant 
mechLical  arilngement,  and  is  likely  to  conduce  to  the  perfection  of  machine-made 
pa^r  Thave  akeady  described  Mr.  Ibotson's  excellent  plan  of  parallel  shts  or  gridiron 
strSners  which  has  been  found  to  form  paper  of  superior  quality,  because  it  penmls  all 
JheSared  tenacious  fibres  to  pass,  which  give  strength  to  the  paper,  while  it  intercepts 
the  coarS  knots  and  lumps  of  he  paste,  that  were  apt  to  spoil  its  surface.  Mr.  Turn- 
S's  c^irc^ar  w?re  sieves,  presently  to  be  noticed,  may  do  good  work,  but  they  cannot  com- 
SefewUh  Mr  Dickinson's  present  invention,  which  consists  in  causing  the  dUuted  paper 
TufpTo  pass  i,etween  longitudinal  apertures,  about  the  hundred-and-fifteenth  part  of  an 
Mich  wide,  upon  the  surface  of  a  revolving  cylinder.  v  •„    „  ^«i;^„„^ 

The  pulp  being  diluted  to  a  consistency  suitable  for  the  paper  machine,  is  de  ivered 
into  a  vat,  of  which  the  level  is  regulated  by  a  waste  pipe,  so  as  to  keep  it  nearly  full. 
From  this  vat  there  is  no  other  outlet  for  the  pulp,  except  through  the  wire-work  pen- 
nhm  of  the  revolving  cylinder,  and  thence  out  of  each  of  its  ends  mto  troughs  placed 
alongside,  from  which  it  U  conducted  to  the  machine  destined  to  convert  it  into  a 

^ThcTevolving  cvlinder  is  constructed  somewhat  like  a  squinel  cage,  of  circular  rods, 
or  an  endless  spiral  wire,  strengthened  by  transverse  metallic  bars,  and  so  formed  that  the 
spaces  between  the  rings  are  suflicient  to  allow  the  slender  fibres  of  the  pulp  to  pass 
throueh,  but  are  narrow  enough  to  intercept  the  knots  and  other  coarse  impurities, 
which  must  of  course  remain,  and  accumulate  in  the  vat.  The  spaces  between  the  wires 
of  the  squirrel  cage  may  vary  from  the  interval  above  stated,  which  is  mtended  for  the 
finest  paper,  to  double  the  distance  for  the  coarser  kinds.  ,  ,     .         v   v    • 

It  has  been  stated  that  the  pulp  enters  the  revolving  cylinders  solely  through  the  inter- 
val^ of  the  wires  in  the  circumference  of  the  cylinder;  these  wires  or  rods  are  about 
three  ei'^hths  of  an  inch  broad  without,  and  two  eighths  within,  so  that  the  circular  slits 
diverge  ^internally.  The  rods  are  one  quarter  of  an  inch  thick,  and  axe  riveted  to  the 
transverse  bars  in  each  quadrant  of  their  revolution,  as  well  as  at  their  ends  to  the 

necks  of  the  cylinder.  ^  j      .v  .v 

Durin*'  the  rotation  of  the  cylinder,  its  interstices  would  soon  get  clogged  with  the 
pulp  were  not  a  contrivance  introduced  for  creating  a  continual  vertical  agitation  in  the 
inside  of  the  cylinder.  This  is  effected  by  the  up-and-down  motion  of  an  interior  agitator 
or  plunger,  nearly  long  enough  to  reach  from  the  one  end  of  the  cylinder  to  the  other, 
made  of  stout  copper,  and  hollow,  but  water-tight.  A  metal  bar  passes  through  it,  to 
whose  projecting  arm  at  each  end  a  strong  link  is  fixed ;  by  these  two  links  it  is  hung  to 
two  levers,  in  such  a  way  that  when  the  levers  move  up  and  down,  they  raise  and  depress 
the  a<'itator,  but  they  can  never  make  it  strike  the  sides  of  the  cylinder.  Being  heavier 
than  Its  own  bulk  of  water,  the  agitator,  after  being  lifted  by  the  levers,  sinks  suddenly 
afterwards  by  its  weight  alone.  ...  _, 

The  agitator's  range  of  up-and-down  movement  should  be  about  one  inch  and  a  quarter, 
and  the  number  of  its  vibrations  about  80  or  100  per  minute ;  the  flow  of  the  pulp  through 
the  apertures  is  suddenly  checked  in  its  descent  and  promoted  in  its  ascent,  with  the 
effect  of  counteracting  obstructions  between  the  ribs  of  the  cylinder. 

The  sieve  cylinder  has  a  toothed  wheel  fixed  upon  the  tubular  part  of  one  of  its  ends, 
which  works  between  two  metal  flanches  made  fast  to  the  wooden  side  of  the  vat,  for 
the  purpose  of  keepins  the  pulp  away  from  the  wheel ;  and  it  is  made  to  revolve  by  a 
pinion  fixed  on  a  spindle,  which  going  across  the  vat,  is  secured  by  two  plummer  blocks 
on  the  outside  of  the  troughs,  and  has  a  rotatory  motion  given  to  it  by  an  outside  rigger 
or  pulley,  by  means  of  a  strap  from  the  driving  shaft,  at  the  rate  of  40  or  50  revolatio!it 


342 


PAPEB-PULP  STRAINER. 


rer  minute.  This  spindle  has  also  two  double  eccentrics  fixed  upon  it,  immediately 
under  the  levers,  so  that  in  every  revolution  it  lifts  those  levers  twice,  and  at  the  same 

**"The  dlametw^*  *the  sieve  cylinder  is  not  very  material,  but  14  inches  have  been  found 
a  convenient  size ;  its  length  must  be  regulated  according  to  the  magnitude  of  the  machine 
which  it  is  destined  to  supply  with  pulp.  One,  four  feet  long  in  the  cage  part,  is  sufficient 
to  supply  a  machine  of  the  largest  size  in  ordinary  use,  viz  ,  one  capable  of  making  paper 
4  feet  6  inches  wide.    When  the  cyUnder  is  of  this  length,  it  should  have  a  wheel  and 

^"ue^l  flanchTs  ire  firmly  fixed  to  the  sides  of  the  vat,  with  a  water-tight  joint,  and 
form  the  bearings  in  which  the  cylinder  works. 

Mr.  Turner  of  Berraondsey,  paper-maker,  obtained  a  patent  m  March,  1831,  lor  a 
peculiar  strainer,  designed  to  arrest  the  lumps  mixed  with  the  finer  paper  pulp,  thereby 
he  can  dispense  with  the  usual  vat  and  hog  in  which  the  pulp  is  agitated  mimedialely 
before  it  is  floated  upon  the  endless  wiie-web  of  the  Fourdrinier  apparatus.  His  strainer 
may  also  be  applied  advantageously  to  hand  paper  machines.  He  constructs  his  sieves 
of  a  circular  form,  by  combining  any  desirable  number  of  concentric  rings  of  metal, 
with  small  openings  between  them,  from  the  50th  to  the  lOOlh  part  of  an  inch  wide.  In 
order  to  facilitate  the  passage  of  the  fine  pulp  and  water,  the  sieves  receive  a  vibratory 
motion   up   and  down,  which  supersedes  the   hog   employed    m   other   paper  making 

"°  A  mechanism  to  serve  the  same  purpose  as  the  preceding,  in  which  Mr.  Ibotson»s  plan 
of  a  parallel  rod-strainer  is  modified,  was  made  the  subject  of  a  patent  by  Mr.  Henry 
Brewer,  of  Surrey  Place,  Southwark,  in  March,  1832.  He  constructs  square  boxes  with 
gridiron  bottoms,  and  gives  a  powerful  up-and-down  vibration  in  the  pulp  tub,  by  levers, 

rotatory  shafts,  and  cranks.  r  i  t    l  n  j        v  ♦i.:- 

As  the  contrivance  is  not  deficient  in  ingenuity,  and  maybe  useful,  I  shall  describe  thw 
mode  of  adapting  his  improved  strainers  to  a  vat  in  which  paper  is  to  be  made  by  hand 
moulds.  A  hog  (or  churning  rotator)  is  employed  for  the  purpose  of  agitating  the  pulp 
at  the  bottom  of  the  vat,  in  which  the  sieve  is  suspended  from  a  crank-shaft,  or  in  any 
other  way,  so  as  to  receive  the  up-and-down  vibratory  motion  for  the  purpose  of  straining 
the  pulp.  The  pulp  may  be  supplied  from  a  chest,  and  passed  through  a  cock  into  a 
trough,  by  which  it  is  conveyed  to  the  strainers.  ,.,.,.       ,  . 

A  pipe  from  the  bottom  of  the  vat  leads  into  a  lifter-box,  which  is  designed  to  convey 
thin  pulp  into  the  sieve,  in  order  to  dilute  that  which  is  delivered  from  the  chest.  This 
pipe  also  allows  the  small  lumps,  called  rolls,  to  be  re-sifted.  The  pressure  of  the  pulp 
and  water  in  the  vat  forces  the  pulp  up  the  pipe  into  the  lifter-box,  whence  it  is  taken 
by  rotatory  lifters,  and  discharged  into  a  trough,  where  it  runs  down  and  mixes  with 
the  thick  pulp  from  the  chest,  as  before  mentioned.  By  these  means  the  contents  of 
the  vat  are  completely  strained  or  sifted  over  again  in  the  course  of  almost  every 

**A  patent  was  obtained  for  a  paper-pulp  strainer  by  Mr.  Joseph  Amies,  of  Loose,  in 
the  county  of  Kent,  paper  manufacturer,  who  makes   the   bottoms  of  his  improved 
strainers  veith  plates  of  brass  or  other  suitable  metal,  and  forms  the  apertures  for  the  fine 
fibres  of  pulp  to  pass  through,  by  cutting  short  slits  through  such  plates,  taking  care 
that  as  much  metal  is  left  between  the  ends  of  each  short  slit  and  the  next  following 
as  will  properly  brace  or  stiffen  the  ribs  of  the  strainer ;  and  he  prefers  that  the  end  of 
one  slit  shall  be  nearly  opposite  to  the  middle  of  the  two  slits  next  adjoining  it,  which 
is  commonly  called  blocking  the  joints.     This  is  for  giving  rigidity  to  the  bottom  of  the 
strainer,  and  constitutes  the  main  feature  of  his  improvement.      The  bottoms  of  sieves 
previously  constructed  with  long  metallic  rods,  he  considers  to  be  liable  to  lateial  vibra- 
tion in  use,  and  thus  to  have  permitted  knots  and  lumps  to  pass  through  their  expanded 
intervals.    This  objection  is  not  applicable  to  Mr.  Dickinson's  squirrel-cage  strainer,  of 
which  the  ribs  may  be  made  rigid  by  a  sufficient  number  of  transverse  bars ;  nor  in  fact 
is  it  applicable  to  Mr.  Ibotson's  original  strainer,  as  it  is  admirably  constructed  by  Messrs. 
Donkin  and  Co.     Each  bar  which  they  make  being  inflexible  by  a  feathered  rib,  is  render- 
ed perfectly  straight  in  its  edge  by  grinding  with  emeiy  upon  a  flat  disc-wheel  of  block  tm, 
and  of  invariable  length,  by  a  most  ingenious  method  of  turning  each  set  of  bars  in  a 
lathe     The  bars  are  afterwards  adjusted  in  the  metallic  sieve-frame,  or  chest,  at  any 
desired  distance  apart,  from  the  120th  to  the  60th  of  an  inch,  in  such  a  manner  as  secures 
them  from  all  risk  of  derangement  by  the  vibratory  or  jogging  motion  m  shaking  the 
pulpy  fibres  through  the  lineal  intervals  between  them.  , 

Mr.  James  Brown,  paper  manufacturer,  of  Esk  mills,  near  Edinburgh,  obtained  a 
patent  in  May,  1836,  for  a  particular  mode  of  applying  suction  to  the  pasty  web  in 
the  Fourdrinier's  machine.  He  places  a  rectangular  box  transversely  beneath  the  hori- 
Kmtal  wire  cloth,  without  the  interposition  of  any  perforated  covering,  such  as  had  been 


PAPER  CYLINDER  MACHINE. 


343 


tried  in  the  previously  constructed  vacuum  machines,  and  which  he  considers  to  have 
S^ed'ed  l^ei?Xacy'in  condensing  the  pulp  and  extracting  the  water. 

merous  small  perforations  t^*  the  paper  j^  continuous  paper  machine  was 

A  modification  of  Mr.  Dickinson  s  cy»™J«  .         ^  Dartford,  as 

„ade  the  -^i«"  "^  »  J»7  „;:iJ^„e7Sf  ab^ad'  Th"^^^^^  f-""  "'..l!" 
eonununicated  to  him  »?  »  "f''"*;,!  i„  „hich  the  wire  cylinder  is  immersed  with  • 
invention  is  a  mode  »f  ?"PP'j'"j,^' ™f  ereaUng  a  considerable  pressure  upon  the  exter- 
r:u"rrat7  Wntr%7dT^f  causin,\h^  fibres  of  the  paper  pulp  to  «ihere  t. 

%rre"is  a  -i-cyUndric^  t^ugh  in  whi^h  Jbe  m^^^ 

revolve  by  any  '""^ll^"' ■""^"*;/.te  Cm!n»"ld  opposite  to  the  vat,  thee  is  a  cis- 
at  its  bottom  paru  9n  the  side  »f '7.fjX«ed;whdeh  passes  thence  into  the  semi- 
tern  into  which  a  copious  How  of  "»'"■'/«"' "."^^^^^^  L  «  bent  or  syphon  tube  is 
cylindrical  trough.  In  the  ■"'"'"'^  "J  *'^^f.*'\„J^  j.-X  the  ™^^  reVolves.  ThU 
introduced,  on  the  horizonta  part  of  ™''''='?  «"'^'  '"'^'wa^rTdrawn  from  the  in- 
tube  is  connected  at  the  outs^e  ^;;^'X''V^[J^f,,*:eri;iindSrtrough,  on  the 
ter  or  of  the  cylindrical  mould.  Thus  .y>«  "?'"  j"  ,  .  ,v'  ;,  jg  within;  arvd con- 
outside  of  the  drum,  is  kept  at  a  «»»5'^«"">  Jf  ""^  '^.1'  w?re  gauze,  will,  it  it  sup- 
scuentiy  '^e  pressure  of  the  water  as  it  P^-«,*  »»f,,f,i7-„S:e  of  the  moulS: 

In  order  to  keep  the  pulp  properly  agitated  in  the  mould  vat j^  a  se^^eni         ^       ^^5 

Ara.  cuuin     mi  r>  communicaton  from  a  foreigner  residing   abroad. 

tlTTl^^r^CZl  pr  lU  anln^L^^'^^^^^^^^  which  they  are  agit^ed  tj 

rrpLmVelhe  dust  •nfe  Seaned  fragments  are  delivered  o^  ^o  a  horizontal  screen  or 
^nS^a  table  to  suffer  examination.  When  picked  here,  they  are  ready  for  the  pulp- 
^^.    A  dSinct  repTesLation  of  this  machine  is  given  in  Newton's  Journal,  con- 

*'Mr  Jetn 'jltuI;'jeq^ui^r^L^^^  a  patent  in  August,  1831,  for  a  mode  of  making 
naSer'  on    the    conUn„7us  machine  with  wire-marks.      The    proposed  improvement 
Ets  merely  in  the  introduction  of  a  felted  pressing  roller,  to  act  upon  the  paper  afl« 
U  has  beTn  diJcharged  fr  >m  the  mould,  and  need  not  therefore  JL«  P;^2rv  J^the  co^ 
In  August,  1830,  Mr.  Thomas  Barratt,  paper-maker,  of  St.  Maiy  Cray,  in  the  county 
of  Kent  obtained  I  patent  for  an  apparatus  by  which  paper  may  be  manufactured  ma 
^nSous   hUtrwi^h  the  water-mark  and  maker's  name,  so  as  to^e^en^^l^^jl/;^ 
respect  paper  made  by  hand,  in  moulds  the  size  of  each  separate  sheet.     On  the  vme 
web  at  equal  distance  J  apart  repetitions  of  the  maker's  name  or  other  device  is  i^ace^ 
recording  to  the  size  of  the 'paper  when  cut  up  into  sing  e  «»^««ts- J«  °^^"/*^*^'^"^ 
such  paper,  the  ordinary  method  of  winding  upon  a  reel  cannot  be  employed ;    a^ 
therefore  the  patentee  has  contrived  a  compensating  reel,  whose  diameter  diminishes  a^ 
«Iich  revolution,  equal  to  the  thickness  of  a  sheet  of  paper.    See  Newton's  Journal,  C.  S. 

""^F Jr"  Mr.^Lemuel  Wellman  Wright's  series  of  improvements  in  the  manufacture  of 
paper,  spedfied  in  his  patent  of  November,  1834, 1  must  refer  to  the  above  Journal, 

^  A  commiltee  ?f  the  SociitS  d' Encouragement,  of  Paris,  made  researches  upon  the  best 
composition  for  sizing  paper  in  the  vat,  and  gave  the  foUowmg  recipe  :— 

60 


344 


PAPER,  SIZING  OF. 


100  kilogrammes  of  dry  paper  stuff. 
12        —  starch. 

1        —  rosin,  previously  dissolved  in  500  gnunmet 

,o      .,      -  of  carbonate  of  soda. 

18  pails  of  water. 

M.  Braconnot  proposed  the  foUowing  formula  in  the  23d  volume  of  thp  JhtrurU.  ^m 
Chxmteet  de  Physique  :-To  100  parts  of  dry  stuff,  properly  dXsedthrou^ItJ? 
add  a  boilm?  uniform  solution  of  8  parts  of  flour  with  ftTrnLh  .•  *"^°"?'i  ^»^er, 

«„der  .he  li,uor  clear.    AM  U,lZ^ZiT^u!^''s^,"'^^.^^^aisZ7^t^, 

e  Jof  tlnP^«n7d '  P""*''  si^e  them  previously  with  the  following  composition  :-4  oun- 
Te  Sh^^nn  •  7?^  ""^  "^^^^  '*^^P  ^^«^«'^^  '^  3  English  pints  of  horwatei      When 

inm^J^r-      •'  ^?Pi^^^'  t^«  o"«ces  of  pounded  alum  must  be  added,  andls  si>n  as  th« 

VaZenC^t  m^liVfor^iztr;^^^^^^^^^  t'"''"^''''''  ^^^^^''  ^^  ^^^'^^^  ^^ 

100  kilogrammes  of  dry  stuff. 
J  —  glue. 

8  —  resinous  soap, 

"  —  alum. 

uniform ,  the  ?lue,  prev[ottX  MftM;H  hv  I9  h       '       ""  '^'  "?'""''  ''*<='"»"  I""* 

•826,  p.  226,  but  they  ISlrdlfprLserv^^^^^^ 

iree  has  been  acclimated  in  France  ^""««a'"e  '»  «  European  manufacturer.    Thai 

smooth  tables,  in  order  to  d^  it  flat     ?^^^  ^'^^^  ^'^  ^>  ^"^^^-^'  "P«^ 

feet  long,  and  two  broad      It  i,  mLp  nf  ikI  k  ^"P^°y^  'P^  engravings  is  in  sheets  four 
too  strong  for  tMs  purpose.  '  ^*™'^ '  '^^"^  myrtle-tree  paper  would  be 

Paper,  sizing  of.     Mr   John  Dickinson  obtained  a  patent,  in  1840  for  a  mo^.  nf 

•   Tu    V    *  ii  7Vac«7i</  Paper. 

dieet  must  be  put  Lwee^n  t^o  sheeTofVray  p^ptt ^th^^^^^^^^^  ^'^^^ 

must  be  renewed  sev^al  times,  to  preven?  th^e'ba'nkTotf;a'prf;om^^^^^^^^^^ 

Tliissubjecthasocc^fe^tllt'Sntf^^^  . 

writing  traced  upon  it  had  ^^^^:^^ S:^^:^  ^^  P^Vl^ 


^ 


PAPER. 


345 


two  kinds  of  pulp,  the  one  perfectly  white,  the  other  dyed  of  any  colour  easily  affected 
by  chlorine,  acids,  and  alkalis.  The  latter  stuff  being  mingled  with  the  former  in  any 
desired  proportion,  will  furnish  a  material  for  making  a  paper  which  will  contain 
coloured  points  distributed  throughout  all  its  substance,  ready  to  show,  by  the 
changes  they  suffer,  whether  any  chemical  reaction  has  been  employed. 

PAPER.  The  construction  of  wire-web  cylinders  for  paper-making  machines,  and 
Ihe  combination  of  two  such  cylinders  in  one  machine,  by  the  use  of  which  two  distinct 
thicknesses  of  paper  pulp  are  obtained,  and  applied  face-wise,  to  form  one  thick  sheet, 
were  made  the  subject  of  a  patent  under  the  name  of  John  Donkin.  Two  cylinders 
are  so  placed  in  a  vat  that  their  circumferences  are  nearly  in  contact,  and  by  being 
turned  in  opposite  directions,  they  bring  two  sheets  of  paper  pulp  into  contact,  and  in- 
corporate them  into  one,  by  what  is  technically  termed  couching. 

An  extensive  patent  for  improvements  in  the  manufacture  of  paper  was  granted  to 
Charles  Edward  Amos  in  1840.  These  consist,  first,  in  gradually  lowering  the  roll  of 
the  engine  in  which  the  rags  are  prepared  and  converted  into  pulp ;  secondly,  in  a  mode 
of  regulating  the  supply  of  pulp  to  the  paper-making  machine,  in  order  to  produce  papers 
of  any  required  thickness;  thirdly,  in  an  improved  sifter  or  strainer  through  which  the 
pulp  is  passed  for  clearing  it  of  knobs  and  lumps ;  fourthly,  in  certain  modifications  of 
the  parts  of  the  machine  in  which  the  pulp  is  deposited  and  moulded  into  continuous 
lengths  of  paper ;  fifthly,  in  an  improved  method  of  heating  the  cylinders  of  the  drying 
apparatus  ;  and,  sixthly,  in  improvements  of  the  machinery  for  cutting  the  paper  into 
sheets  of  any  required  dimensions.  The  details  of  these  ingenious  contrivances,  illus- 
trated  with  engravings,  are  given  in  Newton's  Journal,  xx.,  p.  153.,  C.  S. 

Henry  Crossley  purposes  to  manufacture  paper  from  waste  tan,  and  spent  hops— 
with  what  success  I  have  not  heard.  Joseph  Hughes  gives  a  higher  finish  to  the  long 
web  of  paper  by  friction  between  two  cylinders,  the  one  of  which  moves  much  quicker 
than  the  other,  botb  being  covered  with  felt  or  not,  at  pleasure. 

Mr.  John  Dickinson,  the  eminent  paper  manufacturer,  obtained  a  patent  in  1840 
for  a  new  mode  of  sizing  paper  continuously,  in  an  air-tight  vessel  (partly  exhausted 
of  air),  by  unwinding  a  scroll  of  dried  paper  from  a  reel,  and  conducting  it  through 
heated  s'ze;  then,  after  pressing  out  the  superfluous  size,  winding  the  paper  on  to  an- 
other reel. 

A  longitudinal  section  of  the  apparatus  employed  for  this  purpose  is  represented 
Jig.  1044;  where  a  is  the  air-tight  vessel ;  6,  the  reel  upon  which  the  paper  to  be  sized 
is  wound ;  whence  it  proceeds  beneath  the  guide-roller  c,  and  through  the  warm  size 
*o  another  guide-roller  d.  It  thence  ascends  between  the  press-rolls,  «,/ (by  whose 
revolution  the  paper  is  drawn  from  the  reel  6),  and  is  wound  upon  the  reel  g.  A  float 
h  is  suspended  from  the  cross-bar  t,  of  the  vessel  a,  for  the  purpose  of  diminishing  the 
surface  of  size  exposed  to  evaporation ;  and  beneath  the  bottom  of  the  vessel  is  aa 
enclosed  space,;,  into  which  steam  or  hot  water  is  introduced  for  maintaining  the  tem 
nerature  of  the' size. — Newton^s  Joumalf  xxiii.  20. 


Messrs.  Charles  Cowan  and  Adam  Ramage,  paper-makers,  patented,  in  1840,  im- 
proved rag  machinery ;  in  which  a  cylindrical  sieve  or  strainer  of  wire-cloth,  of  a 
peculiar  construction,  is  substituted  for  the  ordinary  strainers,  by  which  the  dirty  water 
Is  separated  from  the  pulp.  They  do  not  claim  the  cylindric  form  or  sieve,  but  "  the 
adding  or  applying,  and  combining  within  the  interior  of  such  drum,  scoops,  or 
buckets,  for  the  purpose  of  elevating  the  water,  which.has  entered  into  it  through  its 
wire  circumference,  so  that  the  water  when  elevated  may  be  able  to  run  by  its  own 
gravity  out  of  the  hollow  around  the  central  axis  of  the  drum  into  any  suitable  shoot 
or  trough,  and  escape  at  a  level  above  the  surface  of  the  water  and  rags  or  material 
contained  in  the  paper-machine." 


V 

>l  -' 


1 


346 


PAPER. 


Thomas  Barrett  claims,  in  his  patent  of  1841,  «  a  mode  of  drying  paper  by  applying 
streams  of  air  to  its  two  surfaces,  as  it  passes  over  the  steam  cylinders,  whether  in  the 
state  of  engme  size  or  water  leaf,  or  after  sizing ;  as  also,  the  application  of  currents  of 
air  to  the  surfaces  of  paper,  after  sizing,  in  order  to  cool  the  size ;  as  the  paper  is  pass- 
ing to  the  drying  cylinders." 

^!f,**®^""P™^^°^«^^  "*  paper-making,  for  which  T.  W.   Wrigley,  of  Bridge  Hall 
Mills,  Bury,  obtained  a  patent  In  1842,  relate  to  the  rag  engine.  Jigs.  1045,1046,1047, 


1048.  JFtg'.  1045is  a  side  elevation ;  ^g.  1046,  a  transverse  section,  taken  lengthwise 
through  nearly  its  middle;  y!g.  1047  a  plan  view  of  the  apparatus  detached  upon  a 


1048 


1047 


larger  scale;  and  j^g.l048is  an  elevation.  T^e  vessel  in  which  the  rags  are  placed  is 
shown  at  a  a,  and  in  about  the  centre  of  this  vessel  the  beating  or  triturating  roll,  b,  6, 
is  placed :  it  is  surrounded  with  the  blades  or  roll  bars,  c  c,  fig.  1046.  The  roll  is 
mounted  upon  a  shaft,  d  d,  one  end  of  which  is  placed  in  a  pedestal  or  bearing  on  the 
further  side  of  the  chamber  a,  and  the  other  in  a  bearing  upon  the  arm  or  level  e  «•, 
fig.  1045  which  is  supported  by  its  fulcrum,  at  the  end  e*,  in  one  of  the  standards,/  /, 
and  at  the  other  end  by  a  pin  fixed  in  the  connecting  rod,  g  g.  At  the  upper  end  of 
this  connecting  rod  there  is  a  cross-piece,  or  head  A,  having  turned  pivots  at  each  end 
upon  which  are  placed  small  rollers,  i  t,  resting  upon  a  horizontal  cam,  k  fe,  which  is 
made  to  revolve.  This  cam,  k  fc,  by  means  of  its  gearing,  causes  the  roll  6  first  of  all 
to  wash  the  rags  a  short  time,  then  to  be  lowered  at  whatever  rate  is  desired  for  break- 
ing the  fibres;  to  be  maintained  at  the  lowest  point  for  the  required  number  of  revolu- 
tions for  beating ;  and  to  be  raised  and  retained,  as  required,  for  the  final  purpose  of 


PAPER. 


341 


clearing  the  pulp.  The  upper  or  working  edge  of  this  cam  is  to  be  shaped  exactly 
according  to  the  action  required  by  the  engine  roll;  as,  for  instance,  suppose  the 
previous  operation  of  washing  to  be  completed,  and  the  time  required  for  the  operation 
of  the  rag  machine  to  be  three  hours,  one  of  which  is  required  for  lowering  the  roll, 
that,  or  the  first  division  of  the  working  surface  of  the  cam,  k  k,  must  be  so  sloped  or 
inclined,  that,  according  to  the  speed  at  which  it  is  driven,  the  rollers  upon  the  cross- 
head  shall  be  exactly  that  portion  of  the  time  descending  the  incline  upon  the  cam, 
and  consequently  lowering  the  roll  upon  the  plates  Vyfig.  ill ;  and  if  the  second  hour 
shall  be  required  for  the  roll  to  beat  up  the  rags,  the  roll  revolving  all  the  time  in 
contact  with  the  plates,  the  second  division  of  the  cam,  k  fc,  must  be  so  shaped  (that 
is,  made  level),  that  the  roll  shall  be  allowed  to  remain,  during  that  period,  at  its  lowest 
point;  and  if  the  third  portion  of  the  time,  or  an  hour,  be  required  for  raising  the  roll 
again,  either  gradually  or  interruptedly,  then  the  third  division  of  the  cam,  k,  must  be 
suitably  shaped  or  inclined,  so  as  to  cause  the  cross-head  to  lift  the  roll  during  such 
interval  or  space  of  time ;  the  particular  shape  of  the  inclined  portions  of  the  cam  de- 
pending on  the  manner  in  which  the  manufacturer  may  wish  the  roll  to  approach  to  or 
recede  from  the  bottom  plates,  during  its  descent  and  ascent  respectively. 

Its  mode  of  connexion  and  operation  in  the  rag  engine  is  as  follows  :   supposing  that 
the  rags  intended  to  be  beaten  up  are  placed  in  the  vessel  a,  fig.  HI,  and  motion  is 
communicated,  from  a  steam-engine  or  other  power,  to  the  farther  end  of  the  shaft  d, 
the  roll  6,  will  thus  be  caused  to  revolve,  and  the  rags  washed,  broken,  and  beaten  up, 
as  they  proceed  from  the  front  weir  m,  over  the  bottom  plates  n,  and  again  round  by 
the  back  weir  o.     There  is  a  small  pulley  p,  upon  the  near  end  of  the  shaft  rf,  round 
which  a  band  q  passes,  and  also  rouno  another  pulley  r,  upon  the  cross  shaft  s  ;  upoa 
this  shaft  is  a  worm  /,  gearing  into  a  worm-wheel  «,  fixed  upon  another  shaft  r,  below ; 
upon  the  reverse  end  of  which  is  a  pinion  ty,  gearing  into  a  spur-wheel  a:,  upon  the  end 
of  a  shaft  y ;  and   upon  the  centre  of  this  shaft  y,  there  is  another  worm  z,  gearing 
into  a  horizontal  worm-wheel  1,  upon  which  the  cam,  k  k,  is  fixed.     Thus  it  will  be 
seen,  that  the  requisite  slow  motion  is  communicated  to  the  cam,  which  may  be  made 
to  perform  half  a  revolution  in  three  hours ;  or  it  will  be  ev  lent,  that  half  a  revolution 
of  the  cam,  fcfe,  maybe  performed  in  any  other  time,  according  to  the  calculation  of  the 
gearina:  employed.     The  shaft  may  also  be  driven  by  hand,  so  as  to  give  the  required 
motion  to  the  cam.     Supposing,  now,  at  the  beginning  of  the  operation,  the  cross  head 
bearing  the  lever  and  roll,  to  be  at  the  highest  point  upon  the  cam,  k  fc,  as  its  revolu- 
tion commences,  the  roll  will  revolve  for  a  short  time  on  the  level  surface  of  the  cam. 
and  will  then  be  lowered  until  the  cam,  k  fe,  has  arrived  at  that  point  which  governs  the 
time  that  the  roll  remains  at  the  lowest  point,  for  the  purpose  of  beating  the  rags  into 
palp,  and  as  the  cam,/cAr,  continues  to  revolve,  and  thus  brings  the  opposite  slope  upoa 
the  third  portion  of  its  working  surfiace  into  action  upon  the  cross  head,  the  roll  will  be 
raised,  in  order  to  clear  the  pulp  from  knots  and  other  imperfections,  and  thus  complete 
the  operation  of  the  engine.     In  order  to  raise  the  cross  head  and  roll  to  the  height 
from  which  it  descended  without  loss  of  time,  or  to  lift  the  cross  head  entirel}'  from  off 
the  cam  when  requisite,  a  lever,  2,  or  other  suitable  contrivance  may  be  attached  to  the 
apparatus,  also  a  shaft  may  be  passed  across  the  rag-engine,  and  both  ends  of  the  roll 
may  be  raised  instead  of  one  only,  as  above  described. 

'the  patentee  does  not  claim  as  his  invention  the  lowering  and  raising  the  roll  of 
the  rag-engine,  nor  the  lowering  of  it  by  mechanism,  as  this  was  effected  in  Mr.  Amos's 

patent  of  1840  ;  but  he  claims  the  above  peculiar  apparatus  for  this  purpose. Heio- 

ion^s  Journal,  xxiii.  254.  C.  S. 

Quantity  of  Paper  charged  with  Duties  of  Excise,  in  the  United  Kingdom,  in 


1834. 

1835. 

1836. 

First  Class   -        -        -        -        - 
Second  Class        .... 
Pasteboard,  millboard,  <fec. 

Stained        -        -        -        -        . 

lbs. 

54,053,721 

16,552,168 

49,392 

yards. 

8,749,144 

lbs. 

56,179,555 

17,863,095 

49,772 

yards. 

8,247,931 

lbs. 

66,202,689 

15,906,258 

36,340 

yards. 

8,032,567 

Amount  of  duty,  first  class, 

—  second  class, 

—  pasteboard,  Ac 

—  stained 

£         s.     d. 

675,671  10     0 

103,461     0    0 

54,689     0    0 

63,796  16     0 

£         s.     d. 

702,244     9     0 

111,644     0     0 

54,548  15     0 

60,141     0     0 

£        «.     d 

661,699     0     0 

99,414    0     0 

89,557     0     0 

22,112     0     0 

2Y2 


348 


PAPER. 


PAPER. 


349 


i 

It  f 


The  late  reduction  of  the  duty,  from  Sd.  to  lU  per  lb,  upon  paper  of  the  first  clasi 
Tiz.,  on  all  descnptaons  of  il,  except  that  made  out  of  tarred  fopes  only  has  been  alreaTv 
attended  with  considerable  benefit  to  the  manufacture,  and  would  have  acted  with  mucf 
greater  effect  but  for  the  American  crisis.     The  groS  amount  of  the  paper  dutf^ 
year  ending  6th  January.  1836,  was  831,057/,  and  in  the  year  endlnTsth    Januarv 
1838,  It  was  554,497/.;  instead  of  being  little  more  than^one  half^^s  might  ha7e 

thTvear'  iTsY      Th !'''  ''^^''^'^  "^-'^^  ^"*^'  ^^''^  «^^7  ^*"^«  ^^^  fuH  opfra  ion  In 
inn  Jon    ^^^-     ^^^  ^''''^  revenue  m  1841  was,  633,52o/,  the  nett,  683  647/  •  in  1844 
J09,320  gross,    609,906/.   nett;    in  1847,    810,944/.   gro^s,    762,172/    nett    'in     8M 

925'520  •  ^r.  ^'''''?--  '^^^  ^^P^^  ^^  *"  ^^^^  '^^"Sed  with  duty  in  860 
925,620/.  At  the  same  time  that  the  tax  on  common  paper  was  reduced  that  unon 
stained  paper  was  repealed  altogether.     The  effect  of  the  diminution  consequently 

sTnfntlon  o'f  \lTo"'  ^^'llT^ij^^  ^"^  ^^°  «^  ^''^'  ^'  ^^^^^^  *<>  doubleT  coi 
kcr^  ^^  '^'  ^  ^  ^^^  manufacture  appears  to  be  still  rapidly  on  the 

I^eclared  Value  of  Stationery  and  Printed  Books  exported  in 


Years. 


1827 
1828 
1829 
1830 
1831 
1832 
1833 
1834 
1835 
1836 


Stationery. 


£ 
195,110 
208,532 
190,652 
171,848 
179,216 
177,718 
211,518 
211,459 
259,105 
301,121 


Printed  B)»oks. 


£ 
107,199 
102,874 
109,878 

95,874 
101,110 

93,038 
124,635 
122,695 
148,318 
178,945 


Total. 


£ 
802,309 
811,406 
800,630 
267,722 
280,326 
270,766 
886,063 
834,064 
407,423 
480,063 


Till  the  paper  trade  shall  escape  entirely  from  the  clutches  of  its  ancient  dry-nurse, 
the  excise,  neither  it  nor  the  book  trade  can  acquire  the  same  ascendency  in  exportati^ 
which  all  other  articles  of  British  manufactures  have  over  the  French. 

The  Value  of  Stationery  exported  in  France,  from  1833,  was, 

18,992  francs 


Cartons  lustres  (polished  pasteboards  for  the  cloth  manufacture) 
Cartons  en  feuilles  (pasteboard  in  sheets)  -  -  - 

Cartons  monies  (papier-mache)  -  _  .  . 

Cartons  coupes  et  assembles        -  -  -  .  . 

Wrapping  paper  --.-.. 

White  paper,  and  ray6  (ruled)  pour  musique     -  -  . 

Coloured  paper  in  reams  -  -  -  -  . 

Stained  paper  (paper  hangings)  in  rouleaux        -  -  . 

Silk  paper  -----.. 


6,352 

215,376 

64,184 

178,644 

2,903,075 

68,541 

1,885,387 

3,240 


Total  (—£208,000)  6,323,621  francs 

Mr.  John  Dickinson's  invention  for  sizing  paper,  continuously,  in  an  air-tight  vessel 
(partially  exhausted  of  air,)  by  unwinding  a  scroll  of  dried  paper  from  a  reel,  and  qoZ 


W,m.\mWM<,m^^^^ll^iaiy^y^Yf^^pm 


ducting  it  through  heated  size ;  then,  after  pressing  out  the  superfluous  size,  winding 
the  paper  on  to  another  reel 

A  longitudinal  section  of  the  apparatus  employed  for  this  purpose,  is  represented  in 
^.  1049.  a,  is  the  air-tight  vessel;  6,  the  reel  upon  which  the  paper  to  be  sized  is 
wound,  from  whence  it  proceeds  beneath  the  guide-roller  c,  and  through  the  heated 
size,  to  another  guide-roller  d;  it  then  ascends  between  the  press-rolls  e,f,  (bv  the  revo- 
lution of  which  the  paper  is  drawn  from  the  reel  6  (and  is  wound  upon  the  reel  g), 
A  float  A,  is  suspended  from  the  cross-bar  i,  of  the  vessel  a,  for  the  purpose  of  diminish- 
ing the  surface  of  size  exposed  to  evaporation ;  and  beneath  the  bottom  of  the  vessel  is 
an  enclosed  space  y,  into  which  steam  or  hot  water  is  introduced,  for  raising  the  tem- 
perature of  the  size. 

Water-marks.  —  In  the  manufacture  of  all  hand-made  papers,  for  the  purpose  of 
writing  or  printing  upon,  and  of  much  machine-made  paper,  for  the  like  purposes,  it  is 
the  practice  to  form  therein  a  device,  name,  and  date,  or  some  of  them,  known  as  the 
water-mark.  These  marks  are  produced  by  attaching  to  the  surface  of  the  mould  or 
dandy  roller,  employed  in  the  manufacture  of  paper  (usually  by  sewing  with  fine  wire)^ 
cylindrical  and  sometimes  flattened  wire,  previously  formed  into  the  designs  or  marks 
intended  to  be  produced  in  the  paper;  which  designs  or  marks,  thus  attached  to  and 
lying  above  the  general  surface  of  the  mould,  occupy  a  space  thereon,  which,  if  they 
had  been  absent,  would  have  been  charged  with  pulp,  and  thereby  cause  the  sheet  of 
paper  in  progress  of  manufacture  to  be  thinner  at  the  particular  parts  of  the  mould 
where  the  marks  or  designs  are  attached,  by  the  thickness  of  the  wire  used  in  the  same 
marks  or  designs ;  and  the  same  apparent  effect  is  indeed  produced  upon  the  sheet  of 
paper  in  progress  of  manufacture  as  is  produced  by  an  ordinary  die  on  any  substance 
It  may  be  caused  to  act  upon, — with  this  difference,  however,  that  on  the  sheet  of  paper 
the  impression  is  the  sunken  one. 

It  is  obvious,  from  the  use  of  cylindrical  wire,  or  flattened  wire,  having  its  sides 
parallel  with  each  other,  that  the  mark  ultimately  produced  will  be  formed  of  a  number 
of  lines  of  equal  breadth ;  unless,  indeed,  in  the  same  figure,  wires  of  different  gauges, 
thicknesses,  or  breadths,  be  employed ;  and  even  in  the  latter  case  (which,  indeed,  in 
practice,  it  is  believed  seldom  occurs),  the  transition  from  the  different  gauges  would  be 
abrupt  and  ill  adapted  to  the  proposed  end.  Also  in  forming  designs  of  intricacy  with 
wire,  a  frequent  crossing  of  it  is  necessary ;  by  which  means,  at  the  points  of  crossing, 
the  mark  will  necessarily  be  the  thickness  of  two  wires,  and,  consequently,  the  water- 
mark on  the  sheet  of  paper  will  be  stronger  at  those  points ;  or,  if  to  avoid  the  crossing 
the  wire  be  cut,  so  that  an  end  might  abut  against  the  length  of  the  wire  in  an  intricate 
design,  the  pieces  of  wire  would  be  so  short  and  so  numerous  as  to  render  the  sewing 
or  fastening  of  them  to  the  mould  exceedingly  difficult  and  of  great  expense,  and,  in 
some  cases,  wholly  impracticable.  With  respect  to  the  imitation  of  hand-writing,  or  the 
introduction  of  fac-simile  autographs  as  water-marks,  it  is  scarcely  necessary  to  observe, 
that  the  observations  before  made,  in  relation  to  general  designs,  will  apply  with  greater 
force  to  them ;  and  that,  at  the  best,  they  would  be  very  imperfect,  and  in  many  cases, 
could  not  be  effected  at  alL  The  remarks  made,  with  reference  to  the  water-marking 
upon  moulds,  is  equally  applicable  to  dandy-rollers. 

The  object  of  this  invention  is  to  remedy  the  defects  before  pointed  out,  and  to  pro- 
duce a  simple  mark,  or  one  of  the  highest  ornamental  character  or  intricacy ;  the  hues 
of  which  may  vary  from  a  thin  line  or  faint  shade  to  one  of  a  greater  depth  of  tone  or 
breadth ;  or,  on  the  contrary,  from  a  depth  of  shade  to  a  fainter  one ;  and  also  to  afford 
facility  for  introducing  water-marks  of  the  greatest  intricacy,  without  the  inconvenience 
or  expense,  before  alluded  to,  of  crossing  the  wire,  and  thus  rendering  some  parts 
thicker  than  the  main  body  of  the  mark,  or  cutting  the  wire  into  innumerable  small 
pieces. 

These  effects  are  attained  bv  the  following  means,  whereby  also  the  patentee  is  en- 
abled to  produce  fac-similes  of  ordinary  hand-writing  and  of  autograph  signatures:— 
A  plate  of  brass,  copper,  or  other  metal,  being  provided,  of  the  requisite  substance  to 

Sroduce  the  depth  of  water-mark  impression  in  the  pulp  (which  substance  must  be 
etermined  according  to  the  required  weight  or  thickness  of  the  paper) — to  one  side 
of  this  plate  is  to  be  attached,  by  glue  or  other  suitable  means,  a  piece  of  card-board  or 
Tcneer  of  wood,  for  the  purpose  of  giving  it  rigidity  and  support ;  and  the  design  to  be 
produced  in  the  pulp  as  a  water  mark,  having  been  drawn  on  paper,  is  then  to  be 
affixed,  by  glue  or  other  suitable  means,  to  the  other  surface  of  the  plate.  If  the  sheets 
of  paper  to  be  manufactured  are  not  required  to  be  very  heavy,  the  plate  may  be  thin ; 
and  two  thin  plates  of  metal  may  be  attached  together,  and  be  operated  upon  at  one 
time.  In  this  case,  the  paper,  with  the  draught  of  the  design,  may  be  affixed  to  the 
outer  surface  of  one  of  a  pair  of  plates,  previously  attached  together  by  glue,  or  other 
matter,  having  a  piece  of  card-board  or  veneer  of  wood  between  them,  for  the  purpose 
of  keeping  the  two  thicknesses  of  metal  in  contact,  and  for  giving  them  rigidity.     The 


i 


'I 


19  I: 


\ 


H 


350 


PAPER. 


plate,  supported  as  stated,  or  the  pair  of  plates,  connected  as  described,  is  or  are  f7i«. 
to  be  pierced  or  perforated  round  the  outlines  of  the  device  bvTliw«.l«^LY?  *? 
purpose  (after  the  method  of  cutting  buhl  workl  aecordwX  f k  '  ?.  ^  ^  ^a  •*** 
drawn  as  before  mentioned.  The  plat?  or  X^es  havW  h.in^  -^  Vf^^rxy  or  design 
cut  to  the  figure  of  the  device,  thosfportion^  o?  the  m  perforated,  or 

or  watermark  are  then  to  be  disengaged  Cm  the  p^rt^  of  the  li-^^''''"     "^  '^^'"^ 

quired:  which  having  been  done,  the  drawn  paper  Wee  card  C!^  ^  '  "^^  ""^ 
be  removed ;  and  if  two  plates  of  metal  h^ve  been  cu?^f  Anf^  ."^  or  veneer,  must 
separated  from  each  othe? :  this  seTaration'L  well  a^^^  *^*>'  ^'^  *«  ^^ 

device,  card-board,  or  veneer,  can  be  efFected^^soakfng  L  ho  "  orl^^'"  Ht' 

"^^S^:^^:^  o^rdLr/methoVof  ':^^.^^:^^^^^^^^ 

In  cases  where  a  high  finish  to  the  water-mark  or  design  is  reauired  or  Ha-J^oKU  +u 
edges,  and  such  other  parts  of  the  metal  as  may  be  deSred  shm  M  h!  nK      f      5  *t* 
rounded,  or  cut  down."^  In  order  to  do  this,  the  ^letal  Ss  or  parte  of  t'^^^^^^        ' 
plates  are  to  be  affixed,  by  some  sufficient  means,  to  a  rigid  b  ockC  hoM  theif  whiW 
operating  upon:  the  metfiod  which  the  patentee  has  adopted  Tto^ln^tl,..       l1 
device  to  a  flat  slab  of  marble,  somewhat  larger  than  th^dev ice    fid  th^s  aSm??,' n/ 
Its  being  readily  removed  by  soaking  in  hot  water,  after  the  operation  next  de^^^^^^ 
has  been  performed.     The  pattern  or  metal  device  being  thusTffixe.nCfn,.  f      ^^ 
thereof  is  then  to  be  dresse/ by  cutting  or  filing  at  the  p^arts  where  If  r^.t  K^^     '"'^*^^ 
to  improve  the  effect  of  the  pattern ;  Ld  the^edges  wS  hive  b^^^^^^^^     shXrt^e 
saw  can  be  removed  or  rounded  by  the  scorper  Sr  engraver's  tooTand   thl^f^^i!^ 
off  by  stoning  or  other  suitable  means.     The^bove  m^tho^of  fini^i  tt^±^^^^^ 
designs  applies  only  where  the  device  is  to  be  sewn  on  to  the  mHd  o^r  d«X     1i 
^ith  wire;  but  when  solder  is  used,  the  metal  device  mav-afte^h«vinl  dandy-roUer 

Tlie  patentee,  Mr.  R.  O.  Bancks,  claims  as  his  improvement  or  imT.r«,r^rv,     *    •    *u 

Messrs.  Amos  and  Clare  have  obtained  a  patent  for  employing  in  r^lan^  «f  *i,. 
couch  roll  (for  working  against  the  upper  surface  ofTheTaperY  a  ^ollfw^r^^^ 
T^i  Of,  ^ts  surface,  haying  a  sectiS  box  within  it,  actKL  W "„  «  ^^^^^^^ 
wherebj  the  deposition  of  colouring  matter  is  rendered  equal  Sn  both  "ides  ?fTh^ 
paper,  instead  of  being  greater  on  the  lower  side,  by  the  natural  sXidence  «f  f^! 
colouring  matter  from  the  water.     They  have  also  specified  an  improved  kronfrn! 

a:rr;nt  rr."^^^  ^^^^^ '^-^^"^  ^^ ''-  ordinarTpTpr^lht^f.:: 

Th^th^^f  i;ULP-METER  Patented  by  Charles  Cowan.  Valley-field,  near  Edinburgh, 
^e  object  of  this  apparatus  is  to  measure  out  a  uniform  and  exact  supply^  pu"?/^ 
I  l^^^K^f  ^'^!??  according  to  any  width  and  thickness  of  the  web  of  paper^whicS 
^  may  be  desired  to  make.  The  pulp,  after  having  been  prepared  in  the  engiW  and 
^^ff  oh  /'tJ;*^'''"^  proportions  of  raw  materials  and  water,  is  kept  L  ife  pulp  or 
BtuflF  chest     The  cup  of  the  pulp-meter  which  is  driven  in  connection  with  the  mper 

W  Jnfl  '%"^t  ^?  ^^P  i^*^  \  ^^^  ^^^^^  H  "^^*°«  of  *  ball-cock  or  vX  is  always 
kept  full  of  pulp  from  the  pulp-chest  and  life,  and  delivers  the  requisite  ouanJtTof 
pulp  to  make  the  width  and  thickness  of  the  web  required.  This  iVdone  b\  m"  ans  of 
the  slide  upon  the  cup,  which  can  be  set  even  while  the  apparatus  is  in  motion  so  as  to 
dehver  the  number  of  cubical  inches  of  pulp  at  each  dip  reauired  for  fhl  !^'  !?•  i 
paper  to  be  made,  which  can  be  ascertained  by  a  very  ZpKLl 

boSnfw^t^^^ 

as  to  their  mtellectual  reqf  emente.  is  Le  the  annuaTSc'ease  o  wh7ch  is'oi^LTs'e 
with  the  diffusion  of  knowledge.  And  it  mavhp  fri,W  =o;^  Tu  *  ^"^^"  ^  coextensive 
tually  considered,  thepresentllassrelft^^sr^ 

Ts  LTnsXfvMer  B^^^^^^^^  >  h''  economy  than  any  of  those  ini  whUT  exhfbZn 
nas  been  subdivided.    Books,  it  has  been  said,  carry  the  productions  of  the  human  mind 


PAPER  AND  PRINTING. 


351 


oyer  the  whole  world,  and  may  be  truly  called  the  raw  materials  of  eyery  kind  of 
•cience  and  art  and  of  all  social  improvement.  The  sub-classes  are  as  follows:— A 
paper,  m  the  raw  state  as  it  leaves  the  mill,  such  as  brown  paper,  millboards,  printing 
writing,  and  drawing  papei-s,  <fec  ;  B.  articles  of  stationery,  as  envelopes,  lace  papere, 
fancy  papers,  ornamental  and  glazed  papers,  sealing  wax.  wafei-s»  inks  of  all  kinds, 
Ac. ;  C.  pasteboards,  cards,  (fee  ;  D.  paper  and  scaleboard  boxes,  cartonnerie,  Ac ;  E. 
printing,  not  including  printing  as  a  fine  art,  and  printing  inks  and  varnishes :  book- 
binding  m  cloth,  velvet,  vellum.  <fec. ;  fancy  books,  portfolios,  desks,  Ac. 

The  localities  from  whence  the   articles  exhibited  have  been  sent  are  much  lesa 
restricted  than  m  preceding  classes.     Many  of  the  exhibitors  appear  in  the  capacity  of 
producers  of  small  articles  for  fancy  purposes;  and  as  these  are  obviously  capable  of 
being  made  at  home,  requiring  taste  and  minute  skill  rather  than  mechanical  power 
for  their  manufacture,  the  places  from  which  they  have  been  forwarded  for  exhibition 
have  not  the  special  interest  attaching  to  great  producing  towns  or  cities,  where  thou- 
sands of  mechanics  and  operatives  are  aU  occupied  in  one  department  of  manufacture. 
From  the  metropohs,  however,  where  a  large  demand  for  such  articles  exists,  the  great 
proportion  of  them  are  derived.     London  also  represents  most  largely  the  enormous 
printing  resources  of  this  country.     But  of  these,  as  specimens  only  of  single  works 
can  appear,  but  a  faint  idea  can  be  gained  from  the  examples  exhibited.     Inone  of  the 
greatest  establishments  of  the  metropolis,  twenty  machines  are  constantly  occupied, 
each  of  which  is  capable  of  throwing  off  from  8,000  to  4,000  impressions  per  hour 
and  in  addition  a  large  number  of  printing  machines  for  fine  work  are  employed. 
These  great  printing  establishments  resemble  very  closely  the  large  manufactories  of 
other  districts,  only  their  organization  differs  with  the  peculiar  nature  of  the  manu- 
facture, if  the  mechanical  production  of  printed  books  may  be  so  termed. 

Paper,  more  legitimately  reckoned  among  manufactures  than  printing,  has  a  certam 
limitation  to  districts  for  particular  kinds.  Considerably  more  is  made  in  England  than 
Ml  Scotland  or  Ireland.  Kent  is  celebrated  for  its  fine  writing  and  drawing  papers. 
From  Lancashire,  Berkshire,  Hertford,  and  Derbyshire,  papers  of  various  kinds  are 
supplied.  The  quantity  of  paper  annually  manufactured  in  England  two  years  ago 
amounted  to  132,132,657  lbs.;  in  1834,  it  was  a  little  more  than  half  that  quantity 
In  1839  It  was  estimated  that  the  quantity  used,  if  equally  divided  among  the  popula^ 
tion,  would  have  been  about  three  pounds  and  three  quarters  for  each  individual 

A  variety  of  mechanical  improvemenH  both  in  the  production  of  paper  and  in  that 
of  printed  book^  has  been  introduced  of  late.  In  the  manufacture  of  paper,  the  sub- 
stitution  of  machine  for  hand  labour,  has  been  attended  with  the  most  momentous 
results.  In  1801,  the  price  of  a  ream  of  paper  of  a  particular  description  was  36&' 
m  1843  the  same  paper  could  be  purchased  for  rather  less  than  half  this  sum.  In  1721 
It  18  estimated  that  300,000  reams  of  paper  were  annually  produced  in  Great  Britain. 
In  1841  97,105,550  lbs.,  were  made  in  the  United  Kingdom  the  total  annual  value  is  at 
present  not  far  short  of  two  millions  steriing.  Much  of  the  increase  thus  exhibited  is 
due  to  the  introduction  of  mechanical  power;  but  the  fiscal  regulations  upon  this 
branch  of  industry,  which  were  formerly  extremely  oppressive,  having  been  removed 
^f  ?^  ^t'^^"^  another  cause  of  increased  production  and  consumption  is  thus  super- 
added Paper  may.  however,  be  likewise  regarded  as  a  chemical  product,  as  it  is  cer- 
tain that  a  large  amount  of  chemical  knowledge  has  been  successfully  combined  with 
mechanical  skill  m  its  preparation. 

By  the  co-operative  forces  of  chemical  processes  and  mechanical  instruments,  the 
most  refuse  matter  becomes  converted  into  a  white  and  pure  material.  As  an  evidence 
of  the  enormous  length  of  paper  produced  by  mechanical  power  two  great  rolls  are 
exhibited;  one  is  760  yards  long,  the  other  2,500  yards  in  length  ^ 

The  application  of  improved  machinery  to  printing  is  also  of  decent  date,  and  has 
been  attended  with  results  of  great  moment  Progress  is  still  made  in  this  direction- 
an  entirely  new  principle  m  printing  (the  vertical)  has  been  introduced,  the  applSon 
of  which  for  the  rapid  multiplication  of  newspapers  is  extending.  By  this^ Crng^ 
ment  (the  vertical^  the  power  of  production  is  only  limited  by  thi  sizeof  the  m"chint 
Among  many  mteresting  specimens  of  typography,  those  which  exhibit  the  produt 
toon  of  books  in  other  tongues,  by  type  cast  in  England,  will  attract  notice,  ^^e  Holy 
Scriptures  are  exhibited  m  one  hundred  and  fifty  different  languages,-a  noble  evidence 
of  the  highest  application  of  industry  to  the  enlightenment  and  welfare  of  mlnS 
Beautiful  specimens  of  the  bookbinder's  art  are  likewise  shown  "laniana 

An  envelope-folding  machine,  placed  at  the  side  of  the  Main  Avenue,  is  a  strikmg 
instance  of  the  successful  application  of  mechanical  movements  to  the  performance  o1 
^an^  .K    f'?^  complicated  actions.     By  this  machine,  the  movemente  of  the 

hand  of  the  folder  are  not  only  exactly  imitated,  but  the  result  is  more  accurate  and 
certain,  and  the  power  of  production  is  very  largely  increased. 


1  ^ 

V  ' 

v  ■ 

I''       * 

b 


352 


PAPER  AND  PRINTING. 


PAPER  AND  PRINTING. 


35S 


I 


fi 


The  peculiar  interest  which  attaches  to  the  object*  in  this  class,  as  the  most  power- 
ful aeeK  the  social  and  intellectual  improvement  of  man  cairuot  fail  to  be  awakened 
bv  the  most  casual  inspection.  Papers,  printing,  and  bookbinding,  are,  howeyer,  only 
Se  raw  material,  the  application  and  reproduction  of  which  is  Sependent  upon  the 
nnwprs  of  the  mind,  not  on  those  of  matter.  „       •  *      \.„«v 

^10  AlhTjabez  Henry,  New  North  Road,  Hoxton,  /nt^m/or.-^pecimen  of  a  bank- 
note  foVthe  pretntion  of  forgery,  printed  in  a  chemical  watercolour  --  -^-^^^^^ 
eneravine  the  process  producing  two  colours  at  one  operation  ;  the  lettering  mblacK, 
and  the  ornamental  background  in  a  neutral  tint  Any  signature  upon  this  note  can- 
not  be  erased  without  changing  the  colour.  The  letterpress  on  the  note  cannot  be 
trftn»ferred  or  cooied.  and  is  printed  on  a  prepared  paper.  ,      v*      ««, 

2ZKXjohn!m  Cornlall  Road,  Lambeth,  Produ..r.--Specimens  of  ^pl^t  paper 
and  improved  meth^    of  mounting  woodcuts,  for  illustratmg  books,  framing,  and  other 

PThrm%t\l':rspm^^^^^^^^^^  te^-e  is  extremely  simple.    Two 

Pieces  Jcalico  are^fir^^^^  on  the  sides  of  the  paper  and  <i"e<i-     ^y  ^gentle 

^Xon  eachX^^^    paper  splits  into  halvej  one  «\^^,^-^^^^^^^  ^l  ttTaUco 

one  side,  and  the  other  to  its  opposite,  the  adhesion  J>«*J^;^J°  ^^^f  P*^^"^^^ 
being  greater  than  that  of  the  surfaces  of  the  paper  to  each  f  \«^-    ^^^ 'P'^X^^^^^^ 
niay^tSn  be  removed  bv  damping,  and  so  loosening  the  P^^^^^^f^^^f^Vv  ^^^^^L^^^^^^^^^ 
paper.     A  bank-note,  although  of  extremely  thm  texture  can  in  JJ^^J^yj^fj^/^P^X^ 
Into  two  halves,  on  one  of  which  remains  the  impression  ot  the  plate,  while  tne  oiner 

^  liTh^  interesting  collection  of  paper  in  the  Exhibition  from  various  paper  mill^ 
there  are  Sih^^^^^^^^  niust  be  estimated  by  very  different 

stendards  •  iTfor  ilance,  the  brown  wrapping  and  the  fine  hand-made  drawing  papery 
the  suear  and  the  fine  printing  papers,  the  bibulous  plate-paper  for  engravers  use  and 
S:  3sS:d  writing  pV 'colLtively,  it  exW^^^^ 

which  are  soucht  for  by  English  consumers,  and  which  in  many  respects  ou^f  "«™ 
^ose  required  by  our  Continental  neighbours;  as  an  example  may  l>e  ^^^^ed  the 
8ubstant?aTCS  writmg-papers  and  the  thin  post  papers  of  France  and  Belgium, 
whie  different  qualW^^^  the  difference  of  postal  regulations  in  those  countries^ 

^e  system  ofproducing  paper  in  continuous  lengths  of  machinery  was  first  intro- 
duced  by  mSs^  FourdrinTe?  into  this  country,  they  having  purchased  the  Patent  ri^ht 
of  Mr  GambWho  in  1804,  obtained  permission  from  the  French  government  to  bring 
L' EngW  a  1^^^^^^^  of  a  michine  inve^nted  in  1799  by  ^ojs  Robert    who  ^^^^^^^^^^ 

Xuity  of  Mr.  Bryan  Donkin:  upon  this 'has  been  founded  the  various  descriptions 
of^naDe^maknnff  machines  which  have  since  that  time  been  introduced.  They  consist 
^L^nt^^lWof  ^^^^^^^  by  which  the  paper  pulp  is. made  to  A^T  -  f  .^7;^^^^^ 

arendless  wire  web  •  a  rapid  up  and  down  motion  being  given  to  it  for  the  Purpose 
of  shakwThe  watei'  out  of  the  pulp,  and  thus  producing  a  comp  ete  interweaving  of 
ItSfiLents.  'tL  contin^uoS'sroU  of  P^r  thus  formed  is  turned  o^^^^^^ 
second  solid  cylinder  covered  with  felt,  upon  which  it  is  condensed  by  «  third,  and 
fivpntuallv  delivered  to  drying  rollers. — Exhibition,  Kewfrl  Oj-  ,  ,  -^^^^u,. 
Swedkh  filterinTpaperls  made  with  pure  water,  and  is  more  free  from  impurity 
thaiTanrotherrt^^^      in  fact,  pure  cellulose,  and  yields  only  half  a  per  cent,  of  asli 

'"''^Tl^vZ^r.  those  with  a  ribbed  surface;  wove  papers  those  -tb  a  tiniform 
surface.^  Ce  papers  under  the  microscope.no  longer  appear  of  uniform  tmt ;  on  the 
contrary,  the  particles  of  colour  are  seen  widely  separated. 

materials,  yet,  commercially,  the  attempts  have  been  "f  ^<'«/«^™V         ,  Prm>rietor^ 
76.  D^a  Rue,  Thomas,  &  Co.,  ^0  5^n/t^/    iJotj,  J(ant./ac<^^^^^  ^^ffoU^- 

Envelope-folding  machine  invented  by  Edwin  Hill  and  barren  De  la  ^."^'Y/be  toUow 
^rfsthe  action  of  this  machine :— The  feeding-boy  places  the  previously  e^t  blank 
enve  opTs  on  to  a  small  platform,  which  rises  and  falls  in  tbe  rectangular  recess  fomed 
bTthe^yhndrical  axes  of  the  folders,  the  bearings  of  the  folders  serving  by  ^^^J^^^' 
g^t  on  toVide  the  envelope  into  its  place  at  the  moment  of  tbe  smaU  platfonn  f^in^ 
A  plunger  now  descends  and  creases  the  envelope  by  carrying  it  between  the  foWer- 
axes,  at  the  same  time  turning  the  flaps  upwards  m  a  vertical  direction.  The  plungers 
wUch  descends  as  a  whole,  now  divides  iito  two  parts,  the  ends  rismg  and  the  Bide* 


remaining  down  to  hold  the  envelope  until  the  end-folders  have  operated ;  these  latter 
turn  oyer  the  flaps,  the  one  on  the  right  of  the  feeding-lad  taking  a  slight  precedence^ 
and  being  closely  followed  by  the  gumming  apparatus,  which  takes  gum  from  an  endless 
blanket  working  in  a  trough,  and,  after  applying  it  to  the  two  end  flaps,  retires,  at  the 
same  time  the  remaining  half  of  the  plunger  moves  upwards,  to  allow  of  the  side  folders 
turning  over  the  remaining  two  flaps,  and  the  folder  nearest  the  feeder  taking  precedence. 
During  these  operations,  the  end  folders  have  remained  at  rest,  and  the  whole  four 
open  simultaneously.  The  taking-off"  apparatus  with  its  fingers  tipped  with  vulcanized 
caoutchouc,  now  moves  forward  over  the  folded  envelope,  which  is  lifted  upwards  by 
the  rise  of  the  small  platform  and  retreats  with  it,  placing  each  envelope,  as  it  is  suc- 
cessively folded,  under  those  which  have  preceded  it.  The  envelopes  are  now  knocked 
over  on  to  an  endless  blanket,  and  are  conducted  by  it  between  two  cylinders  for  a  final 
squeeze,  and  then  rise  in  a  pile  up  the  trough.  There  is  a  provision  m  the  machine  by 
which  the  gummer  is  prevented  placing  gum  upon  the  platform,  in  case  the  feeder  omita 
feeding  in  an  envelope.  This  machine  works  at  the  rate  of  2,700  envelopes  per  hour, 
and  although  superseding  hand-labour  in  folding,  it  is  satisfactory  to  find  that^  instead 
of  displacing  hands,  its  introduction,  by  extending  the  consumption,  has  in  reality 
created  work  for  more  than  it  has  displaced. 

Although  the  fashion  of  using  envelopes  was  common  in  France,  and  had  been,  to  a 
small  extent,  introduced  into  England  prior  to  1839,  yet  their  consumption  was  too 
insignificant  to  call  forth  any  but  the  rudest  mechanical  appliances.  It  is  to  the 
stimulus  created  by  the  adoption,  in  1839,  of  Mr.  Rowland  Hill's  system  of  postage 
reform,  and  the  consequent  increased  demand  for  envelopes,  that  their  manufacture 
owes  its  rank  among  the  arts,  and  its  possession  of  some  of  the  most  ingenious  ma- 
chinery recently  invented. 

The  total  annual  number  of  letters  passing  through  the  Post  Office  in  the  United 
Kingdom  before  the  change  in  the  postage  was  about  76,000,000.  The  fourpenny 
rate  and  the  alteration  in  the  system  of  charge  by  number  of  enclosures  to  that  by 
weight,  was  introduced  on  the  5th  of  December,  1839,  and  on  the  10th  of  January, 
1840,  the  rate  was  reduced  to  one  penny;  during  that  year  the  number  of  letters  in- 
creased to  1 69,000,000,  about  half  of  which  were  enclosed  in  envelopes.  The  number 
of  letters  has  been  steadily  increasing  since  that  period,  and  during  the  year  1850,  it 
reached  the  astonishing  number  of  347,000,000,  or  1,000,000  per  day;  the  proportion 
of  letters  enclosed  in  envelopes  has  likewise  increased  from  one-half  to  five-sixths  of  the 
total  quantity,  so  that  in  round  numbers  300,000,000  of  envelopes  paes  annually  through 
the  PostrOffice ;  besides  which  there  is  nearly  an  equal  number  used  in  private  con- 
veyance. What  does  this  million  of  envelopes  contain?  Their  exposition  would 
furnish  an  instructive  and  entertaining  study. 

In  illustration  of  the  articles  sometimes  sent  by  post,  it  may  be  cited,  that  some  yean 
back,  Professor  Henslow  was  in  the  habit  of  receiving  from  members  of  an  agricultural 
society  which  he  had  established,  specimens  of  living  slugs  of  various  kinds,  sent  for 
examination,  with  a  view  to  his  advice  for  their  extermination.  Were  it  not  for  the 
cheap  postage,  many  of  the  publishing  societies  now  in  existence  would  not  have  been 
established,  on  account  of  the  expense  of  collecting  manuscripts,  transmitting  proofe, 
and  circulating  books.  But  it  is  not  only  in  this  way  that  the  postal  reform  hac 
extended  its  benefits,  for  with  the  reduction  of  rates,  a  liberal  policy  has  increased  the 
facilities  of  delivery  by  the  establishment  since  1839  of  4,600  new  post  oflSces,  which 
are  estimated  as  serving  about  14,000  villages. 

154.  Specimens  of  Books  and  Tracts  of  the  Religious  Tract  Society,  instituted  1799. 
Depositories.  56.  Paternoster  Row,  65.  St.  Paul's  Churchyard,  and  164.  Piccadilly. 
Treasurer,  John  Gurney  Hoare.  Esq. :  Honorary  Secretaries,  Rev.  W.  W.  Champneya^ 
M.A.,  and  Rev.  Ebenezer  Henderson,  D.D. ;  Corresponding  Secretary,  Mr.  Jones. 

The  Society  was  formed  to  promote  the  circulation  of  religious  books  and  treatises  in 
foreign  countries,  as  well  as  throughout  the  British  dominions.  It  constitutes  a  Christian 
union  of  members  of  the  Established  Church  and  of  Protestant  dissenters.  It  has 
printed  important  tracts  and  books  in  about  100  languages  ;  its  annual  circulation  from 
the  depository  in  London,  and  from  various  foreign  auxiliaries,  amounts  to  about 
24,000,000;  its  receipts  for  sales  and  benevolent  objects,  to  more  than  62,000/. ;  and 
its  total  distribution  to  March,  1851,  including  the  issues  of  its  aflSliated  societies,  to  about 
649,000,000  copies  of  its  publications.  There  are  now  about  4,743  English  publi- 
cations, besides  several  hundred  in  foreign  languages,  on  its  catalogue.  These  worka 
are  varied  in  size  and  contents,  and  suited  to  different  classes  of  the  community.  Several 
books  and  tracts  specially  designed  to  improve  and  commemorate  the  Great  Exhibition 
have  been  issued  in  English,  French,  German  and  Italian.  By  a  carefully  arranged 
system  in  the  concerns  of  the  depository,  the  sale  of  the  publications  is  maie  to  cover 
all  the  expenses  of  producing  them,  and  of  the  necessary  establishment  of  the  Society^ 
Vol.  IL  2  Z 


354 


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f    ' 


^  I 


Thus,  the  whole  of  the  subscriptions,  donations  and  contributions  is  applied  to  the 
gratuitous  circulation  of  its  publications,  without  any  deduction  or  charge  whatever. 
In  aid  of  home  and  foreign  benevolent  objects  the  Society  receives  about  6,560/.,  per 
annum,  while  its  grants  during  the  past  year  were  8,560/.,  being  2,000/.  beyond  the 
receipts.  The  committee  have  supplied  3,028  libraries  at  half  price  to  national 
British,  parochial,  day,  and  Sunday  schools,  which  were  unable  to  pay  the  full 
amount. 

The  total  grants  of  libraries  for  various  interesting  objects  amount  to  6,055. 

The  Society  has  translated,  printed,  and  circulated  works  in  the  following  languages: 

Northern  Europe. — Icelandic,  Swedish,  Lapponese,  Finnish,  Danish,  Norwegian. 

Southern  Europe. — French,  German,  Latin,  Roraanese,  Enghadin,  Italian,  Maltese, 
Modern  Greek,  Albanian,  Turkish,  Turkish  in  Greek  character,  Turkish  in  Armenian 
character,  Moldavian,  Bulgarian,  Syriac. 

China  and  Indo-Chinese  Countries. — Chinese,  Assamese,  Shyam,  Nagas,  Burmese, 
Peguan,  Talung,  Karen,  Siamese,  Laos,  Cambodian,  Cochin-Chinese,  Loo-Chooan, 
Japanese,  Corean,  <fec. 

Through  the  disinterested  agency  of  devoted  friends  and  missionaries  of  different 
denominations,8everal  languages  have,  for  the  first  time,been  brought  into  a  written  form, 
and  a  sacred  character  has  been  given  by  the  Christian  press  to  the  earliest  literature  of 
a  people  just  emerging  from  a  state  of  barbarism.  As  an  illustration  of  the  extent  of 
the  Society's  operations,  it  may  be  stated  that  Bunyan's  celebrated  work,  "The  Pilgi-im's 
Progress,"  has  been  issued  in  28  of  the  principal  languages  of  the  earth,  spoken  probably 
by  more  than  one-half  of  the  human  family.  In  some  instances  the  work  has  been 
printed  in  Eoman  characters,  as  in  the  following  example : — 

In  Tahitian,  for  the  inhabitants  of  various  islands  in  the  Pacific  Ocean,  thus : — 

I  to'u  hahaere  raa  na  roto  i  medebara  o  teie  nei  ao,  haeri  atura  van  i  te  hoe  vahi, 
e  ana  tei  tana  vahi  ra,  tapae  atura  vau  i  reira  e  roohia  ihora  i  te  taoto  i  roto  i  taua  ana 
ra. 

The  original  of  this  translation  is  the  following : — 

As  I  walked  through  the  wilderness  of  this  world,  I  lighted  on  a  certain  place 
where  was  a  den,  and  laid  me  down  in  that  place  to  sleep,  and  as  I  slept  I  dreamed  a 
dream. 

171.  Gall,  James,  Myrtle  Bank,  Edinburgh,  Inventor. — Gall's  triangular  alphabet  for 
the  blind,  which  by  its  similarity  to  the  common  Roman  alphabet  is  easily  read  by  the 
eye,  and  may  be  taught  without  previous  instruction.  Thiis  alphabet  is  considered  as 
an  improvement  on  circular  alphabets,  by  its  angular  form  ;  the  letters  are  rendered 
more  distinct  to  the  touch ;  and  by  the  exclusion  of  the  capitals,  the  attention  of  the 
blind  is  concentrated  upon  26  instead  of  52  letters,  and  the  size  of  the  printing  may  be 
reduced.  Volume,  containing  the  Epistle  to  the  Ephesians,  printed  for  the  blind  in 
Gall's  triangular  alphabet  with  letters  serrated. 

GaWs  apparatus  for  writing  by  and  to  the  blind — ^The  blind  can  by  this  invention 
readily  correspond  by  post,  and  can  keep  books  and  other  memoranda.  The  apparatus 
consists  of  a  stufi'ed  frame  on  which  the  paper  is  placed ;  of  a  cover  with  bars  to  guide 
the  lines,  which  are  written  from  the  bottom  upwards ;  and  of  small  stamps,  with  the 
letters  formed  of  common  pins,  which  are  pricked  through  the  paper,  and  read  on  the 
opposite  side.  By  means  of  the  two  register  points  on  each  side  of  the  frame,  and  by 
shifting  the  cover  one  half  line  up,  the  paper  is  written  on  both  sides,  each  perfectly 
legible  either  by  the  fingers  or  the  ej'c. 

174.  Muir,  liobert,  4,  Dunlop  Street,  Glasgow,  Inventor.  Electro-stereotype  plate 
for  letter-press  printing.  This  specimen  is  from  a  mould  of  gutta  pereha,  taken  from  a 
page  of  diamond  types  in  a  screw  press.  The  gutta  pereha  was  laid  on  warm,  the 
pressure  applied  immediately,  and  left  on  for  fifteen  minutes.  When  the  mould  was 
taken  off,  it  was  brushed  over  with  plumbago,  and  copper  deposited  upon  it  by  the 
known  process.  When  the  copper  deposit  is  backed  up  with  gutta  pereha,  it  is  ready 
for  press. 

The  advantage  of  electro-stereotype  over  stereotype  is  that  it  will  last  much  longer, 
and  work  much  cleaner.  The  exhibitor  has  worked  one  of  each  together,  and  when 
the  stereotype  was  completely  worn,  the  electro-stereotype  was  as  good  as  at  first. 

Chitta  pereha  plate  to  be  used  in  letter-press  printing.  Plates  made  of  gutta  pereha 
irom  woodcuts,  will  work  a  large  impression  with  letter-press;  advantageous  when 
woodcuts  are  expensive,  as  the  originals  might  be  saved.  Gutta  pereha  plates  can  be 
made  in  a  short  time  at  a  trifling  cost ;  and  when  2,  4,  or  6,  are  worked  together,  it 
will  greatly  facilitate  the  work,  and  lessen  expense. 

Make  a  mould  from  a  woodcut  by  the  method  above  described  ;  brush  it  over  with 
plumbago  ;  lay  it  on  the  press,  face  up,  and  put  warm  gutta  pereha  into  it ;  apply  the 
pressure  as  before.     Several  plates  may  be  got  from  the  same  mould. 

This  process  appears  to  offer  many  advantages,if  the  practictU  difficulties  of  completely 


PARAFFINE. 


855 


covermg  fhe  impressions  of  the  tj^e  letters,  or  the  lines  of  an  engraving,  with  plumbago 
are  not  too  great  The  gutta  pereha  plate,  being  properly  prepared,  is  connected  with 
the  voltaic  battery,  and  placed  in  a  solution  of  the  sulphate  of  copper,  which,  when 
undergoing  electro-chemical  decomposition,  deposits  pure  copper  m  all  the  lines  and 
over  the  entire  surface.  It  would  appear,  if  lead  was  used  instead  of  gutta  pereha 
for  backing  the  plate,  that  it  would  be  better  fitted  for  printing  than  when  gutta 
pereha  is  employed. 

175.  Wyld,  James,  Charing  Cross,  East,  454,  West  Strand,  2,  Royal  Exchange,  and 
the  Great  Globe,  Leicester  Square, — Producer.  An  Atlas  of  the  World,  comprehending 
52  separate  maps  of  its  various  countries,  constructed  and  drawn  from  the  latest  astro- 
nomical and  geographical  observations.  Imperial  quarto,  coloured  and  handsomely 
half-bound. 

Popular  Atlas,  containing  48  maps  of  the  various  parts  of  the  globe,  with  letter-press 
description  to  accompany  each  map. 

The  World  on  Mercator's  projection.  A  new  map  containing  the  most  recent  geo- 
graphical  information,  and  constructed  on  a  new  principle;  4  large  sheets.  The 
World  on  Mercator's  projection,  colored ;  one  large  sheet. 

Post  Roads  of  Germany  and  the  adjacent  states,  with  the  posts  marked.  The  rail- 
roads, the  sea-packet  routes,  and  the  internal  steam  navigation.  Two  sheets  in  cases. 
The  British  Isles,  with  the  topographical  and  physical  features ;  the  lines  of  railway, 
their  primary  and  intermediate  stations ;  the  land  and  water  communications  of  the 
counties,  and  the  steam-packet  routes,  with  the  distances  from  port  to  port  Com- 
piled from  the  Ordnance  Survey ;  2  sheets. 

England,  Wales,  and  the  greater  part  of  Scotland,  a  railway  and  topographical  map, 
drawn  from  the  triangulation  of  the  Ordnance  Survey,  and  the  surveys  of  the  railway 
companies  and  other  sources  of  infoi-mation,  showing  the  lines  of  railways,  the  inland 
navigation,  the  great  and  cross  roads,  market  towns,  and  villages,  witli  the  physical 
features.     4  sheets. 

Plans  of  London  and  Westminster,  with  the  Borough  of  Southwark,  including  the 
adjacent  suburbs,  with  all  the  additions  and  improvements  to  the  present  time,  reduced 
from  the  large  survey,  with  an  alphabetical  list  of  the  principal  streets,  squares,  public 
buildmgs,  <fcc,  and  reference  to  their  situation  on  the  plan ;  also  a  statistical  table  of 
population,  <fec.     2  sheets. 

^  Map  of  the  country  25  miles  round  London,  upon  a  scale  of  1  inch  to  the  mile,  show- 
ing the  turnpike  and  cross  roads,  railroads,  and  stations,  rivers,  woods,  commons,  seats 
of  the  nobihty  and  gentry,  as  well  as  the  market  towns,  villages,  <fec.     4  sheets. 

201.  British  and  Foreign  Bible  Society,  Earl  Street,  Blackfriar,— Producer.  Speci- 
mens, consisting  of  165  books  in  different  languages,  from  170  versions  of  the  Holy 
Scriptures,  either  in  whole  or  in  part,  which  have  been  published,  directly  or  indirectly 
by  the  Society,  of  which  118  are  from  translations  never  before  priiited  •  and  of 
which  more  than  twenty-four  millions  of  copies  have  been  circulated  since  its  institution 
m  1804. 

Eight  specimens  of  four  editions  of  the  English  Bible,  showing  the  improvement 
made  between  the  years  1816  and  1851,  in  reference  to  quality  of  paper,  printing  and 
binding,  at  an  average  reduction  of  62  per  cent,  in  the  cost  price.  '^  ^    ^  ^ 

PARAFFINE.  Distil  beech-tar  to  dryness,  rectify  the  heavy^il  which  collects  at  the 
bottom  of  the  receiver,  and  when  a  thick  matter  begins  to  rise,  set  aside  what  is  distilled 
and  urge  the  heat  moderately  as  long  as  any  thing  more  distils.  Pvrelaine  passes  over* 
containing  crystalhne  scales  of  paraffine.  This  mixture  being  diirested  with  its  own 
volume  of  alcohol  of  0-833,  forms  a  limpid  solution,  which  is  to  be  gradually  diluted 
with  more  alcohol,  till  its  bulk  becomes  6  or  8  times  greater.  The  alcohol,  which  at 
arst  dissolves  the  whole,  lets  the  paraffine  gradually  fall.  The  precipitate  bein*'  n^hed 
with  cold  alcohol  till  it  becomes  nearly  colorless,  and  then  dissolved  in  boiUng  aicohoL  is 
deposited  on  cooling  in  minute  spangles  and  needles  of  pure  paraffine. 

Or  the  above  mixture  may  be  mixed  with  from  J  to  |  its  weight  of  concentrated  sulphu- 
ric acid,  and  subjected  for  12  hours  to  digestion,  at  a  heat  of  150°  F.,  till,  on  cooling,  crys- 
tals of  paraffine  appear  upon  the  surface.  These  are  to  be  washed  with  water,  dissolved 
in  hot  alcohol,  and  crystallized.  Paraffine  is  a  white  substance,  void  of  taste  and  smell, 
feels  soft  between  the  fingers,  has  a  specific  gravity  of  0-87,  melts  at  112°  Fahr.,  boils 
at  a  higher  temperature  with  the  exhalation  of  white  fumes,  is  not  decomposed  by  dry 
distillation,  burns  with  a  clear  white  flame  without  smoke  or  residuum,  does  not  stain 
paper,  and  consists  of  85-22  carbon,  and  14-78  hydrogen;  having  the  same  composition 
as  olehant  gas.  It  is  decomposed  neither  by  chlorine,  strong  acids,  alkalis,  nor  potas- 
sium ;  and  unites  by  fusion  with  sulphur,  phosphorus,  wax,  and  rosin.  It  dissolves 
readily  in  warm  fat  oils,  in  cold  essential  oils,  in  ether,  but  sparingly  in  boiling  absolute 
alcohol.  Paraffine  is  a  singular  solid  bicarburet  of  h\drogen ;  it  has  not  hitherto  been 
applied  io  any  use,  but  it  would  form  admirable  candles. 


356 


PARAfFINE. 


I! 


ji 


\  M 


The   interesting   researches  of  Reichenback,  above  briefly  detailed,  have  lately 
begun  to  assume  a  more  practical  aspect  in  consequence  of  the  efforts  made  by  several 
companies  m  this  country  to  work  up  or  utilise  the  peat  bogs  of  Ireland.     iTie  pro- 
gress yet  made  in  this  patriotic  endeavour  has  not  been  such  as  to  hold  out  any  great 
hope,  either  that  the  project  will  pay  in  a  commercial  sense,  or  that  the  peat  of  Ireland 
can  be  utilised  at  anything  short  of  a  great  national  sacrifice.     In  fact,  all  the  money 
hitherto  invested  in  these  peat  projects  has  been  as  completely  lost  to  its  owners  as  if 
It  had  not  only  really,  but  hteraUy,  been  thrown  into  a  bog.    Part  of  this  unsatisfactory 
result  18  no  doubt  owmg  to  the  newness  of  the  undertakmg,  to  the  want  of  practical 
knowledge,  and  to  the  purely  visionary  and  unfounded  calculations  of  the  projectors, 
who  have  rushed  at  conclusions  in  unison  rather  with  their  wild  hopes  than  with  the 
sober  deductions  of  scientific  experience,  and  without  any  solid  data  upon  which  to 
found  their  eggregious  assertions,  have  made  "the  wish  father  to  the  thought,"  and 
declared  that  to  be  a  fact  which  had  scarcely  the  consistence  of  a  vague  probability. 
As  the  subject  is  one  essentially  contained  within  the  realms  of  manufacturing  chemistry 
we  deem  it  requisite  to  give  a  general  view  of  these  peat  schemes,  but  without  entering 
into  a  specific  examination  of  any  one  project.    By  one  class  of  schemes,  the  solid  or  fixed 
residue  of  the  peat  is  chiefly  contemplated,  by  another  the  fluid  and  gaseous  or  volatile 
products  are  sought  for,  whilst  a  third  class  unites  both  fixed  and  volatile  products,  and 
may  therefore  be  said  to  comprehend  the  whole  question.  The  first  includes  the  makers 
ot  peat  charcoal  »<T  se ;  the  two  last  come  more  immediately  within  the  scope  of  our 
observations,  and  although  these  have  hitherto  failed  to  elucidate  the  principles  upon 
which  the  manufacture  of  peat  into  saleable  products  depends,  they  have  nevertheless 
brought  forth  an  abundance  of  evidence,  that  more  is  to  be  done  in  this  way  than  was 
Dreyiously  anticipated  by  scientific  men.  When  peat  is  subjected  to  distillation  at  a  red 
heat.  It  evolves  matters  precisely  similar  to  those  given  off  by  wood  and  some  kinds  of 
bitumen,  that  is  to  say,  tar,  acetic  acid,  pyroligneous  spirit,  ammonia,  and  gas:  these 
substances,  though  constant  m  their  presence,  are,  however,  extremely  variable  in  their 
quantities,  owmg  to  the  degree  of  heat  which  has  been  employed  for  their  production. 
Thus,  if  a  very  high   temperature    be   employed,  little   else  than  gas  is  produced. 
TiHbereas  with  a  very  low  and  dull  red  heat  the  quantity  of  tar  is  prodigiously  i^creaseJ 
The  latter  is  therefore  the  temperature  most  to  be  desired,  but  as  this  low  heat  neces- 
sitates a  very  slow  and  long  continued  process,  the  common  practice  is  to  steer  a  mid- 
die  course  between  loss  from  destruction  of  products  on  the  one  hand,  and  cost  from 
slowness  of  production  on  the  other.     In  the  case  of  wood  distillation,  where  the  profit 
IS  chiefly  looked  for  from  acetic  acid,  this  middle  course  is  unquestionably  correct  and 
guidmg  themselves  by  this  description  of  experience  the  distillers  of  peat  have  resorted 
to  the  sanae  method.     Indeed  they  have  even  sought  by  an  increased  temperature  to 
quicken  their  operations,  and  compensate  by  this  means  for  the  comparative  poverty 
of  the  article  they  had  to  employ,  since  peat  is  not  nearly  so  rich  in  valuable  producte 
as  wood  18.     But  this  had  given  rise  to  a  great  and  fatal  error,  which  nothing  but  a 
want  of  perception  as  regards  the  differences  of  the  two  cases  could  for  one  moment  have 
permitted.     With  wood  it  is,  as  we  have  said,  acetic  acid  which  forms  the  chief  item 
of  value ;  with  peat  the  acetic  acid  is  not  worth  collecting ;  with  wood  the  paraffine  is 
a  mere  bagatelle,  whereas  with  peat  the  paraffine  must  be  regarded  as  the  nminstay  of 
the  manufacture,  and  without  which  the  peat  of  Ireland  will  remain  as  it  is,  until  that 
seemingly  remote  period  of  future  history,  when  the  arts  and  manufactures  shall  have 
reached  in  that  country  a  degree  of  perfection  akin  to  what  now  prevails  throughout 
Great  Britain.     To  make  charcoal,  or  to  make  any  bulky  article  of  merchandise  in 
Ireland,  18  mere  folly  at  present,  for  as  it  cannot  be  used  on  the  spot,  and  must  come  to 
England  for  consumption,  the  cost  of  transit  shuts  it  out  of  every  market    Therefore  a 
compact  valuable  substance  like  paraffine  is  precisely  the  kind  of  goods  into  which  Irish 
peat  may  be  turned  with  a  fair  prospect  of  remuneration,  for  were  it  not  for  the  expense 
of  carriage,  the  peat  itself  might  be  sent  to  market  In  the  manufacture  of  peat-products 
every  effort  ought  therefore  to  have  been  directed  to  the  increase  of  this  article.    AU 
else  might  and  ought  to  have  been  held  subsidiary  to  this  one  point,  and  more  especially 
so  as  the  very  means  which  serve  to  insure  a  large  formation  of  paraffine  have  the  sami 
effect  upon  the  production  of  the  pyroligneous  spirit,  which  is  the  only  other  article 
that  peat  yields  of  a  quality  to  pay  the  cost  of  transit. 

But  no  weU  directed  efforts  have  hitherto  been  applied  in  this  direction,  and 
the  utmost  amount  of  paraffine  and  pyroligneous  spirit  obtained  by  any  one  of  the 
peat  companies  now  struggling  for  existence  in  Ireland  has  been  only  at  the  rate 
of  three  pounds  weight  of  paraffine  and  half  a  gallon  by  measure  of  pyroligneous 
spirit  from  one  ton  of  peat  True,  indeed,  several  gallons  of  very  foetid  and 
worthless  oil  have  also  resulted,  but  these  add  nothing  to  the  profit  of  the  un- 
dertaking.  As  it  is  very  clear  that  the  working  of  peat  at  present  can  never  pay 
utless  some  very  important  modifications  are  introduced  into  the  existing  processed 


PARCHMENT. 


357 


we  shall  here  briefly  describe  the  conditions  upon  which  alone  success  can  be  hoped 
for,  and  leave  it  to  those  interested  in  the  practical  application  of  our  remarks,  to 
carry  the  principles  out  in  detail.     If  either  paraffine  or  pyroligneous  spirit  be  passed 
in  a  state  of  vapour  through  a  red-hot  iron  or  porcelain  tube,  it  will  be  seen  that  both 
of  these  substances  are  decomposed  and  destroyed  :  from  the  former  a  quantity  of  gas, 
foetid  oil,  and  charcoal  results,  from  the  latter,  gas  and  a  minute  quantity  of  volatile  oil 
alone  arise.     In  both  cases,  however,  the  material  operated  upon  is  destroyed  by  the 
heat,  and  resolved  into  worthless  product^  and  this  is  the  only  observation  which  need 
be  made  in  connexion  with  such  an  experiment,  for  it  demonstrates  most  conclusively 
that  in  the  distillation  of  peat  as  now  practised,  nearly  the  whole  of  the  paraffine  and 
pyroligneous  spirit  must  be  destroyed,  except  the  small  quantity  mechanically  protected 
from  the  heat,  and  carried  forward  to  the  condenser  by  the  gaseous  products  simul- 
taneously evolved  with  it     It  is,  we  say,  obvious  that  the  3  lbs.  of  paraffine  now  pro- 
cured from  1  ton  of  peat  niust  have  been  mechanically  carried  out  of  the  red-hot  furnace 
or  retort  too  rapidly  for  the  destroying  agency  of  the  heat  to  have  acted  upon  it  and 
but  for  this  action  of  the  gas,  no  paraffine  whatever  would  be  obtained,  and  the  same 
remark  applies  to  the  pyroligneous  spirit     Such  being  the  case,  it  appears  to  us  that  the 
gas  given  off  by  peat  is  not  under  any  circumstances,  very  large,  this  ought  to  be  recon- 
ducted over  fresh  peat  in  the  act  of  distillation,  by  which  the  nascent  paraffine  and 
pyroligneous  spirit  will  be  rapidly  swept  out  of  the  retort^  and  carried  away  from  the 
injurious  effect  of  the  heat  into  the  condenser,  whence  they  may  be  securely  taken- 
It  cannot  be  necessary  that  we  should  enter  into  a  detail  of  the  arrangements  requisite 
for  completing  the  idea  here  developed ;  the  principle  is  substantially  explained  above, 
and  nothing  can  be  simpler  than  to  devise  the  mechanical  construction  of  retorts  adapted 
for  such  a  purpose.     Either  a  system  of  reciprocation  between  one  retort  and  another 
or  between  two  separate  beds  of  retorts,  or  the  collection  and  subsequent  use  of  the  gas 
into  and  from  a  holder,  might  be  put  in  practice.    The  main  feature  would  still  con- 
tinue, and  depend  upon  the  same  circumstance,  viz.,  the  restricted  agency  of  the  heat 
upon  the  recently  volatilized  products  of  the  peat 

In  this  way  there  can  be  no  doubt  that  much  of  the  paraffine  now  resolved  into 
worthless  gas  may  be  turned  into  the  market  in  a  solid  form,  and  if  even  the  increased 
production  of  this  article  extended  no  farther  than  from  3  lbs.  to  10  lbs.  from  every  ton 
of  peat  yet  this  alone  would  be  sufficient  to  resuscitate  the  hopes  of  commercial  men, 
and  convert  the  bogs  of  Ireland  into  firm  and  substantial  materials  for  the  investment 

of  British  capital  and  enterprise, — "a  consummation  most  devoutly  to  be  wished." 

Mr.  LeteU  Thompson. 

PARCHMENT.  (Parchemin,  Fr.;  Pergament,  Germ.)  This  writing  material  has 
been  known  since  the  earliest  times,  but  is  now  made  in  a  very  superior  manner  to  what 
it  was  anciently,  as  we  may  judge  by  inspection  of  the  old  vellum  and  parchment 
manuscripts.  The  art  of  making  parchment  consists  in  certain  manipulations  necessaly 
to  prepare  the  skins  of  animals  of  such  thinness,  flexibility,  and  firmness,  as  may  be  re- 
quired for  the  different  uses  to  which  this  substance  is  applied.  Though  the  skins  of  all 
animals  might  be  converted  into  writing  materials,  only  those  of  the  sheep  or  the  she- 
goat  are  used  for  parchment ;  those  of  calves,  kids,  and  dead-born  lambs  for  vellum ; 
those  of  the  he-goat,  she-goat,  and  wolves  for  drum-heads ;  and  those  of  the  ass  for  battle- 
doors.  All  these  skins  are  prepared  in  the  same  way,  with  slight  variations,  which  need 
no  particular  detail. 

They  are  first  of  all  prepared  by  the  leather-dresser.     After  they  are  taken  out  of 
the  hme-pit,  shaved,  and  well  washed,  they  must  be  set  to  dry  in  such  a  way  as  to 
prevent  their  puckering,  and  to  render  them  easily  worked.       The  small  manufac- 
turers  make  use  of  hoops  for  this  purpose,  but  the  greater  employ  a  herse,  or  stout 
wooden  frame.    This  is  formed  of  two  uprights  and  two  cross-bars  solidly  joined  together 
by  tenons  and  mortises,  so  as  to  form  a  strong  piece  of  carpentry,  which  is  to  be  fixed  up 
agamst  a  wall.     These  four  bars  are  perforated  all  over  with  a  series  of  holes  of  such 
dimensions  as  to  receive  slightly  tapered  box- wood  pins,  truly  turned,  or  even  iron 
bolls.     Each  of  these  pins  is  transpierced  with  a  hole  like  the  pin  of  a  violin  by  means 
of  which  the  strings  employed  in  stretching  the  skin  may  be  tightened.     Above  the  hene 
a  shelf  IS  placed,  for  receiving  the  tools  which  the  workman  needs  to  have  always 
at  hand.       In  order  to  stretch  the  skin  upon  the  frame,  larger  or  smaller  skewers 
are  employed,  according    as  a  greatei    or  smaller    piece  of   it  is   to    be  laid   hold 
of.     Six  holes  are  made  in  a  straight  line  to  receive  the  larger,  and  four  to  receive 
the  smaller  skewers  or  pins.     These  smaU  slits  are  made  with  a  tool  like  a  carpenter's 
c^sel,  and  of  the  exact  size  to  admit  the  skewer.     The  string  round  the  skewer  is 
affixed  to  one  of  the  bolts  in  the  frame,  which  are  turned  round  by  means  of  a  key,  like 
that  by  which  pianos  and  harps  are  tuned.    The  skewer  is  threaded  through  the  skin  in 
a  state  of  tension. 
Every  thing  being  thus  prepared,  and  the  skin  being  well  softened,  the  wormnaa 


358 


PASTE& 


1 


stretches  it  powerfully  by  means  of  the  skewers  ;  he  attaches  the  cords  to  the  skewers, 
and  fixes  their  ends  to  the  iron  pegs  or  pins.  He  then  stretches  the  skin,  first  with  his 
hand  applied  to  the  pins,  and  afterwards  with  the  key.  Great  care  must  be  taken  that 
no  wrinkles  are  formed.  The  skin  is  «.-ually  stretched  more  in  length  than  in  breadth, 
from  the  custom  of  the  trade ;  though  extension  in  breadth  would  be  preferable,  in  order 
to  reduce  the  thickness  of  the  part  opposite  the  backbone. 

The  workman  now  takes  the  fleshing  tool  represented  under  Currying.  It  is  a  semi- 
circular double-edged  knife,  made  fast  into  a  double  wooden  handle.  Other  forms  of 
the  fleshing-knife  edge  are  also  used.  They  are  sharpened  by  a  steel.  The  workman 
seizes  the  tool  in  his  two  hands,  so  as  to  place  the  edge  perpendicularly  to  the  skin,  and 
pressing  it  carefully  from  above  downwards,  removes  the  fleshy  excrescences,  and  layi 
them  aside  for  making  glue.  He  now  turns  round  the  herse  upon  the  wall,  in  order  to 
get  access  to  the  outside  of  the  skin,  and  to  scrape  it  with  the  tool  inverted,  so  as  to 
run  no  risk  of  cutting  the  epidermis.  He  thus  removes  any  adhering  filth,  and  squeezes 
out  some  water.  The  skin  must  next  be  ground.  For  this  purpose  it  is  sprinklod 
upon  the  fleshy  side  with  sifted  chalk  or  slaked  lime,  and  then  rubbed  in  all  directions 
with  a  piece  of  pumice-stone,  4  or  5  inches  in  area,  previously  flattened  upon  a  sandstone. 
The  lime  gets  soon  moist  from  the  water  contained  in  the  skin.  The  pumice-stone  is 
then  rubbed  over  the  other  side  of  the  skin,  but  without  chalk  or  lime.  This  operation 
is  necessary  only  for  the  be^t  parchment  or  vellum.  The  skin  is  now  allowed  to  dry 
upon  the  frame ;  being  carefully  protected  from  sunshine,  and  from  frost.     In  the  arid 

weather  of  summer  a  moist  cloth  needs  to  be  applied  to  it  from  time  to  time,  to  prevent 
Its  drying  too  suddenly  ;  immediately  after  which  the  skewers  require  to  be  tightened. 

When  it  is  perfectly  dry,  the  white  color  is  to  be  removed  by  rubbing  it  with  the 
woolly  side  of  a  lambskin.  But  great  care  must  be  taken  not  to  fray  the  surface  ;  a  cir- 
cumstance of  which  some  manufacturers  are  so  much  afraid,  as  not  to  use  either  chalk  oi 
lime  in  the  polishing.  Should  any  grease  be  detected  upon  it,  it  must  be  removed  by 
steeping  it  in  a  lime  pit  for  10  days,  then  stretching  it  anew  upon  the  kerse,  after  which 
It  is  transferred  to  the  scraper 

This  workman  employs  here  an  edge  tool  of  the  same  shape  as  the  fleshing-knife,  but 
larger  and  sharper.  He  mounts  the  skin  upon  a  frame  like  the  herse  above  described  ; 
but  he  extends  it  merely  with  cords,  without  skewers  or  pins,  and  supports  it  generally 
upon  a  piece  of  raw  calfskin,  strongly  stretched.  The  tail  of  the  skin  being  placed 
towards  the  bottom  of  the  frame,  the  workman  first  pares  off",  with  a  sharp  knife,  any 
considerable  roughnesses,  and  then  scrapes  the  outside  surface  obliquely  downwards  with 
the  proper  tools,  till  it  becomes  perfectly  smooth  :  the  fleshy  side  needs  no  such  operation, 
and  indeed  were  both  sides  scraped,  the  skin  would  be  apt  to  become  too  thin,  the  only 
object  of  the  scraper  being  to  equalize  its  thickness.  Whatever  irregularities  remain, 
may  be  removed  with  a  piece  of  the  finest  pumice-stone,  well  flattened  beforehand  upon 
a  fine  sandstone.  This  process  is  performed  by  laying  the  rough  parchment  upon  an  ob- 
long plank  of  wood,  in  the  form  of  a  stool ;  the  plank  being  covered  with  a  piece  of  soft 
parchment  stuffed  with  wool,  to  form  an  elastic  cushion  for  the  grinding  operation.  It  is 
merely  the  outside  surface  that  requires  to  be  pumiced.  The  celebrated  Strasburgh 
Tellum  is  prepared  with  remarkably  fine  pumice-stones. 

If  any  small  holes  happen  to  be  made  in  the  parchment,  they  must  be  neatly  patched, 
by  cutting  their  edges  thin,  and  pasting  on  small  pieces  with  gum  water. 

The  skins  for  drum-heads,  sieves,  and  battledoors  are  prepared  in  the  same  way.  For 
drums,  the  skins  of  asses,  calves,  or  wolves  are  employed ;  the  last  being  preferred.  Ass 
skins  are  used  for  battledoors.  For  sieves,  the  skins  of  calves,  she-soats,  and,  best  of  all, 
he-goats  are  employed.     Church  books  are  covered  with  the  dressed  skins  of  pigs. 

Parchment  is  colored  only  green.  The  following  is  the  process.  In  500  parts  of  rain 
water,  boil  8  of  cream  of  tartar,  and  30  of  crystallized  verdigris  ;  when  this  solution  is 
cold,  pour  into  it  4  parts  of  nitric  acid.  Moisten  the  parchment  with  a  brush,  and  then  ap- 
ply the  above  liquid  evenly  over  its  surface.  Lastly,  the  necessary  lustre  may  be  given 
with  white  of  eggs,  or  mucilage  of  gum  arabic. 

PARTING  (Depart,  Fr. ;  Scheidutig,  Germ.),  is  the  process  by  which  gold  is  separated 
from  silver.     See  Assay,  Gold,  Refining,  and  Silver. 

PASTEL,  is  the  French  name  of  colored  crayons. 

PASTEL,  is  a  dye  stuff*,  allied  to  Indigo,  which  see. 

PASTES,  or  FACTITIOUS  GEMS.  (Pierre*  precieuses  artiJicieUes,FT.',  GlaspasteHy 
Germ.)  The  general  vitreous  body  called  Strass,  (from  the  name  of  its  German  inven- 
tor,) preferred  by  Fontanier  in  his  treatise  on  this  subject,  and  which  he  styles  the  May- 
ence  base,  is  prepared  in  the  following  manner  : — 8  ounces  of  pure  rock-crystal  or  flint 
in  powder,  mixed  with  24  ounces  of  salt  of  tartar,  are  to  be  baked  and  left  to  cool.  The 
mixture  is  to  be  afterwards  poured  into  a  basin  of  hot  water,  and  treated  with  dilute  nitric 
acid  till  it  ceases  to  effervesce ;  and  then  the  frit  is  to  be  washed  till  the  water  comes  ofl' 


PASTES. 

tasteless.  This  is  to  be  dried,  and  mixed  with  12  ounces  of  fine  white-lead,  and  the  mix- 
ture is  to  be  levigated  and  elutriated  with  a  little  distilled  water.  An  ounce  of  calcined 
borax  being  added  to  about  12  ounces  of  the  preceding  mixture  in  a  dry  state,  the  whole 
IS  to  be  rubbed  together  in  a  porcelain  mortar,  melted  in  a  clean  crucible,  and  poured  out 
into  coU  water.  This  vitreous  matter  must  be  dried,  and  melted  a  second  and  a  third 
time,  always  in  a  new  crucible,  and  after  each  melting  poured  into  cold  water,  as  at  first, 
taking  care  to  separate  the  lead  that  may  be  revived.  To  the  third  frit,  ground  to  pow- 
der, 5  drachms  of  nitre  are  to  be  added ;  and  the  mixture  being  melted  for  the  last  time, 
a  mass  of  crystal  will  be  found  in  the  crucible,  of  a  beautiful  lustre.  The  diamond  may 
be  well  imitated  by  this  Mayence  base.  Another  very  fine  white  crystal  may  be  ob^ 
tained,  according  to  M.  Fontanier,  from  8  ounces  of  white-lead,  2  ounces  of  powdered 
borax,  h  grain  of  manganese,  and  3  ounces  of  rock-crystal,  treated  as  above. 

The  colors  of  artificial  gems  are  obtained  from  metallic  oxydes.  The  oriental  topaz  if 
prepared  by  adding  oxyde  of  antimony  to  the  base ;  the  amethyst,  by  manganese  with  a 
little  of  the  purple  of  Cassius  ;  the  beryl,  by  antimony  and  a  very  little  cobalt ;  yellow 
artificial  diamond  and  opal,  by  horn-silver  (chloride  of  silver) ;  blue-stone  or  sapphire,  by 
cobalt.    The  following  proportions  have  been  given  : — 

For  the  yellow  drnmand.  To  1  ounce  of  strass  add  24  grains  of  chloride  of  silver,  or 
10  grains  of  glass  of  antimony. 

For  the  sapphire.  To-24  ounces  of  strass,  add  2  drachms  and  26  grains  of  the  oxyde 
sf  cobalt. 

For  the  oriental  ruby.  To  16  ounces  of  strass,  add  a  mixture  of  2  drachms  and  48 
grains  of  the  precipitate  of  Cassius,  the  same  quantity  of  peroxyde  of  iron  prepared  by 
nitric  acid,  the  same  quantity  of  golden  sulphuret  of  antimony  and  of  manganese  calcined 
with  nitre,  and  2  ounces  of  rock  crystal.  Manganese  alone,  combined  with  the  base  in 
proper  quantity,  is  said  to  give  a  ruby  color. 

For  the  emerald.     To  15  ounces  of  strass,  add  1  drachm  of  mountain  blue  (carbonate 
of  copper),  and  6  grains  of  glass  of  antimony  ;  or,  to  1  ounce  of  base,  add  20  grains  ot 
glass  of  antimony,  and  3  grains  of  oxyde  of  cobalt. 

For  the  common  opal.  To  1  ounce  of  strass,  add  10  grains  of  horn-silver,  2  grains  of 
calcined  magnetic  ore,  and  26  grains  of  an  absorbent  earth  (probably  chalk-marl) 
Fontanier. 

M.  Douault-Wieland,  in  an  experimental  memoir  on  the  preparation  of  artificial  colored 
stones,  has  otfered  the  following  instructions,  as  being  more  exact  than  what  were  pub- 
lished before. 

The  base  of  all  artificial  stones  is  a  colorless  glass,  which  he  calls  fondant,  or  flux ; 
and  he  unites  it  to  metallic  oxydes,  in  order  to  produce  the  imitations.  If  it  be  worked 
alone  on  the  lapidary's  wheel,  it  counterfeits  brilliants  and  rose  diamonds  remarkably 
well. 

This  base  or  strass  is  composed  of  silex,  potash,  borax,  oxyde  of  lead,  and  sometimes 
arsenic.  The  silicious  matter  should  be  perfectly  pure ;  and  if  obtained  from  sand,  it 
ought  to  be  calcined  and  washed,  first  with  dilute  muriatic  acid,  and  then  with  water. 
The  crystal  or  flint  should  be  made  redhot,  quenched  in  water,  and  ground,  as  in  the  pot- 
teries. The  potash  should  be  purified  from  the  best  pearlash ;  and  the  borax  should  be 
refined  by  one  or  two  crjstallizalions.  The  oxyde  of  lead  should  be  absolutely  free  from 
tin,  for  the  least  portion  of  this  latter  metal  causes  milkiness.  Good  red-lead  is  prefera- 
ble to  litharge.  The  arsenic  should  also  be  pure.  Hessian  crucibles  are  preferable  to 
those  of  porcelain,  for  they  are  not  so  apt  to  crack  and  run  out  Either  a  pottery  or 
porcelain  kiln  will  answer,  and  the  fusion  should  be  continued  24  hours ;  for  the  more 
tranquil  and  continuous  it  is,  the  denser  is  the  paste,  and  the  greater  its  beauty.  Ths 
following  four  recipes  have  afforded  good  strass : — 


No.  I. 

Grains. 

Rock  crystal       -        -        .        -  4056 

Minium      -        ...        -  6300 

Pure  potash        -        -        -        -  2154 

Borax         -        -        .        .        .  276 

Arsenic      .....  12 

No.  n. 

Sand 3600 

Ceruse  of  Clichy  (pure  carbonate  of 

lead) 8508 

Potash 1260 

Borax 360 

Arsenic      .....  12 


No.  III. 


Rock  crystal 

Minium 

Potash 

Borax 

Arsenic 


Rock  crystal 
Ceruse  of  Clichy 
Potash 
Borax 


No.  IV. 


Grains. 

3456 

5328 

1944 

216 

6 


3600 

8508 

1260 

36a 


I         ;!; 


360 


Or, 


PATTERN  DISPLAYING  MACHINE. 

r«Va*.  Grain.. 

Very  white  paste    ........  joog 

Glass  of  antimony  •-......  43 

Cassius  purple        ........  | 


Paste     ---.-. 
Oxyde  of  iron,  called  Saffron  of  Mars 


3456 
36 


Ruby. 


M.  Wieland  succeeded  in  obtaining  excellent  imitations  <rf*  rubies,  by  making  use  of 
the  topaz  materials.  It  often  happened  that  the  mixture  for  topazes  gave  only  an  opaque 
mass,  translucent  at  the  edges,  and  in  thin  plates  of  a  red  color.  1  part  of  this  substance 
being  mixed  with  8  parts  of  slrass,  and  fused  for  30  hours,  gave  a  fine  yellowish  crystal, 
like  paste,  and  fragments  of  this  fused  before  the  blowpipe,  afforded  the  finest  imitation 
of  rubies.  The  result  was  always  the  same. 
The  following  are  other  proportions  for  rubies  : —  Grains. 

Paste 2880* 

Oxyde  of  manganese       .......  72 

Emerald. 

Paste 4608 

Green  oxyde  of  p\re  copper    •-....  42 

Oxyde  of  chrome    ........  2 

Sapphire,  Grains. 

Paste 4608 

Oxyde  of  cobalt 68 

This  mixture  should  be  carefully  fused  in  a  luted  Hessian  crucible,  and  be  left  30  hours 
in  the  fire. 


Jlmethyst, 

Grains. 

Paste 4608 

Oxyde  of  manganese    ...  36 

Oxyde  of  cobalt       ....        24 
Purple  of  Cassius        ...  1 

Beryl,  or  .Aqua  Marina. 
Paste 

Glass  of  antimony    ... 
Oxyde  of  cobalt 


Syrian  Garnet,  or  .Ancient  Carbuncle. 

Grains. 
Paste     ----.-      512 


Glass  of  antimony 
Cassius  purple 
Oxyde  of  manganese 


256 
2 
2 


Grains. 
3456 
24 


In  all  these  mixtures,  the  substances  should  be  mixed  by  sifting,  fused  very  carefully, 
and  cooled  very  slowly,  after  having  been  left  in  the  fire  from  24  to  30  hours. 

M.  Lan^on  has  also  made  many  experiments  on  the  same  subject.    The  following  are 
a  few  of  his  proportions  : — 

Paste.  Grains. 


Litharge  .  .  -  -  -  100 
White  sand  .....  75 
White  tartar,  or  potash  -        .        10 

Emerald. 

Paste 

Acetate  o(  copper 

Peroxyde  of  iron,  or  saffron  of  Mars 


Amethyst.  Grains. 

Paste 9216 

Oxyde  of  manganese     .      '  from  15  to  24 
Oxyde  of  cobalt      ...  j 

Grains. 
.      9216 
72 
1-5 


PASTILLE  is  the  English  name  of  small  cones  made  of  gum  benzoin,  with  powder 
of  cinnamon,  and  other  aromatics,  which  are  burned  as  incense,  to  diffuse  a  grateful  odor, 
and  conceal  unpleasant  smells  in  apartments.     See  Perfumery. 

PASTILLE  is  the  French  name  of  certain  aromatic  sugared  confections  j  called  also 
tablettes. 

PATTERN  DISPLAYING  MACHINEL  This  is  an  ineenious  contrivance  of 
Messrs.  Stewart  and  Hutcheson,  of  Paisley,  for  inventing  and  displaying  patterns  of 
printed  goods  or  worked  patterns,  in  stripes,  cheques,  and  tartans  by  means  of  sliding 
mirrors  and  coloured  glass,  and  is  suitable  for  manufacturers  of  textile  fabrics  of  all 
descriptions. 

The  advantages  of  this  machine  are  the  facility  with  which  any  pattern,  or  idea  of  a 


PEARLS,  ARTIFICLiL. 


Ml 


pattern,  maj  be  set  up  and  displayed,  the  variety  of  designs  it  can  produce,  and  the  ease 
and  simplicity  of  accomplishing  them.  It  is  not  at  all  necessary  to  paint  the  pattern  on 
paper,  after  viewing  it  through  the  mirrors,  as  the  scales  attached  show  at  once  the 
required  number  of  threads  of  each  colour,  and  how  many  repeats  are  necessary  for  the 
breadth  of  the  web ;  and  it  displays  at  once  not  only  the  repeat,  but  the  whole  breadth, 
and  a  considerable  portion  of  the  length  of  the  cloth  at  one  view. 

By  this  invention,  the  precise  effect  of  a  pattern  may  be  produced  in  the  course  of  a 
few  minutes,  without  any  expense,  multiplied  to  any  extent,  and  it  may  be  enlarged  or 
diminished  at  pleasure.  The  chief  novelty,  however,  of  this  machine,  which  was  exhi  bited 
for  Its  simplicity  and  the  ease  of  its  adaptation,  is  that  the  precise  effect  of  the  cloth  in 
a  finished  state  is  accurately  represented,  the  crisp  transparent  effect  of  a  silk  fabric 
being  truly  given,  as  well  as  the  soft  and  more  opaque  effect  of  a  woollen  fabric. 

This  invention  is  new  in  principle,  being  a  novel  application  of  coloured  glass  to 
useful  and  essentially  practical  purposes. 

PEARLASH,  a  commercial  form  of  Potash,  which  see. 

PEARLS  {Perks  Fr. ;  Perlen,  Germ.),  are  the  productions  of  certain  shell-fish.  These 
molluscffi  are  subject  to  a  kind  of  disease  caused  by  the  introduction  of  foreign  bodies 
within  their  shells.  In  this  case,  their  pearly  secretion,  instead  of  being  spread  in  layers 
upon  the  mside  of  theu:  habitation,  is  accumulated  round  these  particles  in  concentric  lay- 
ers.    Pearl  consists  of  carbonate  of  lime,  interstratified  with  animal  membrane. 

The  oysters  whose  shells  are  lichest  in  mother  of  pearl,  are  most  productive  of 
these  hiehly  prized  spherical  concretions.  The  most  valuable  pearl  fisheries  are  on  the 
coast  of  Ceylon,  and  at  Olmutz  in  the  Persian  Gulf,  and  their  finest  specimens  are  more 
highly  prized  m  the  East  than  diamonds,  but  in  Europe  they  are  liable  to  be  rated  very 
differently,  according  to  the  caprice  of  fashion.  When  the  pearls  are  large  truly 
spherical,  reflecting  and  decomposing  the  light  with  much  vivacity,  they  are  much 
admired.  But  one  of  the  causes  which  renders  their  value  fluctuating,  is  the  occasional 
te  of  their  peculiar  lustre,  without  our  being  able  to  assign  a  satisfactory  reason  for  it 
JJesides,  they  can  be  now  so  well  imitated,  that  the  artificial  pearls  have  nearly  as  rich  an 
appearance  as  the  real. 

PEARLS,  ARTIFICIAL.  These  are  small  globules  or  pear-shaped  spheroids  of 
thin  glass,  perforated  with  two  opposite  holes,  through  which  thev  are  strung,  and 
mounted  into  necklaces,  &c  like  real  pearl  ornaments.  They  must  'not  only  bewhite 
and  brilliant,  but  exhibit  the  iridescent  reflections  of  mother  of  pearl.  The  liquor 
employed  to  imitate  the  pearly  lustre,  is  called  the  essence  of  the  East  {essence  d'  orient), 
which  is  prepared  by  throwing  into  water  of  ammonia  the  brilliant  scales,  or  rather  the 
lamelUe,  separated  by  washing  and  friction,  of  the  scales  of  a  smaU  river  fish,  the  Way. 
called  m  French  ableite.  These  scales  di-ested  in  ammonia,  having  acquired  a  degree  of 
softness  and  flexibility  which  allow  of  their  application  to  the  inner  surfaces  of  the  glass 
globules,  they  are  introduced  by  suction  of  the  liquor  containing  them  in  suspension.  The 
ammonia  IS  volatilized  in  the  act  of  drying  the  globules. 

It  is  said  that  some  manufacturers  employ  ammonia  merely  to  prevent  the  alteration 
of  he  scales;  that  when  they  wish  to  make  use  of  them,  they  suspend  them  in  a 
well  clarified  sol u  ion  of  isinglass,  then  pour  a  drop  of  the  mixture  into  each  bead 
and  spread  it  round  the  inner  surface.  It  is  doubtful  whether,  by  this  method,  the  same 
lustre  and  play  of  colors  can  be  obtained  as  by  the  former.  It  seems  mor^ver  to  be 
«n.  T^""  f  """^  for  the  success  of  the  imitation,  that  the  globules  be  formed  of  a  bluish, 
opalescent,  very  thin  glass,  containing  but  little  potash  and  oxyde  of  lead.  In  everv  manu. 
factory  of  artificial  pearls,  there  must  be  some  workmen  possessed  ol  great  experience 
and  dexterity.     The  French  are  supposed  to  excel  in  this  m-enious  branch  of  fX^ 

False  pearls  were  invented  in  the  time  of  Catherine  de  Medicis,  by  a  per^SS^Hhe 
uZ  ^^^'^"^»^'^- ,  ^7  f «  °^«d«  «?  «™^11  globules  of  glass,  blown  1,y  ?he  ordinary 
lamp      The  pearly  lustre  is  communicated  by  introducing  by  means  of  a  blow-pipe  a 
sma     quantity  of  nacreous  substances  obtained  from  the  surface  of  the  scale  of  a 
small  fish  very  common  in  the  Seme  and  the  Rhine,  and  also  in  the  Thames.     This  sub- 
stance preserved  with  sal  ammoniac  in  a  liouid  state  is  commonly  sold  under  the  name 
of    Oriental  essence ;    after  having  covered  the  inside  of  the  pearl  with  this  liquid,  a 
coating  of  wax  is  added,  which  is  coloured  to  the  required  shade.     The  manufacture 
of  pearls  is  principally' carried  on  m  the  department  of  the  Seine  in  France.     There  are 
also  manufactories  m  Germany  and  Italy,  but  to  a  small  extent.     In  Germany,  or  rather 
Saxony,  a  cheap  but  inferior  quality-  is  manufactured.     The  globe  of  glass  forming  the 
pearl  in  inferior  ones  being  very  thm,  and  coated  with  wax,  they  break  on  the  slightest 
pressure.     Ihey  are  known  by  the  name  of  German  fish  pearls;  Italy  also  manufac- 
tures pearls  by  a  method  borrowed  from  the  Chinese;  they  are  known  under  the  name 
of  Roman  pearls,  and  a  very  good  imitation  of  natural  ones;  they  have  on  their  out- 
side  a  coating  of  the  nacreous  liquid.     The  Chinese  pearls  are  made  of  a  kind  of  gum. 
and  are  covered  likewise  with  the  same  liquid.     Lithe  year  1834  a  French  artizau  dS 
Voi.  U.  8  A 


362 


PEARLS,  ARTIFICIAL. 


PEARL  WHTTR 


363 


corered  an  opaline  glass  of  a  nacreous  or  pearly  colour,  very  heavy  and  fusible,  which 
cave  to  the  beads  the  different  weights  and  varied  forms  found  amongst  real  pearls: 
Sum  instead  of  wax  is  now  used  to  fill  them,  by  which  thev  attain  a  high  degree  of 
transparency,  and  the  glassy  appearance  has  been  lately  obviated  bv  the  use  ot  the 
vapour  of  hydro-fluoric  acid.  This  acts  in  such  a  manner  as  to  deaden  the  surface, 
and  remove  its  otherwise  glaring  look.  -     .  .  .     . 

PEARLS,  ARTIFICIAL,  and  BEADS.  The  material  out  of  which  these  are 
formed  are  small  glass  tubes  like  those  with  which  thermometers  are  made.  The  tubes 
for  the  bright  red  pearls  consist  of  two  layers  of  glass,  a  white  opaque  one  mternally, 
and  a  red  one  externally ;  drawn  from  a  ball  of  white  enamel,  coated  in  the  Bohemian 
method  with  ruby-colored  glass,  either  by  dipping  the  white  ball  into  a  pot  of  red 
glass,  and  thus  coating  it,  or  by  introducing  the  ball  of  the  former  into  a  cylmder  of 
Uie  latter  glass,  and  then  cementing  them  so  soundly  together  as  to  prevent  their 
separation  in  the  subsequent  pearl  processes.  These  tubes  are  drawn  in  a  gallery  of 
the  glasshouse  to  100  paces  in  length,  and  cut  into  pieces  about  a  foot  long.  These 
are  afterward  subdivided  into  cylindric  portions  of  equal  length  and  diameter,  pre- 
paratory to  giving  them  the  spheroidal  form.  From  60  to  80  together  are  laid 
horizontally  in  a  row  upon  a  sharp  edge,  and  then  cut  quickly  and  dexterously  at  once 
by  drawing  a  knife  over  them.  The  broken  fragments  are  separated  from  the  regular 
pieces  by  a  sieve.  These  cylinder  portions  are  rounded  into  the  pearl  shape  by  softening 
them  by  a  suitable  heat,  and  stirring  them  all  the  time.  To  prevent  them  from  sticking 
together,  a  mixture  of  gypsum  and  plumbago,  or  of  ground  clay  and  charcoal,  is  thrown 

in  amons  them.  .      t     j      ^..  m^o.a  . 

Jtff5. 1049,1050 represent  a  new  apparatus  for  rounding  the  beads;  ^g.  iU4y  is  a 
front  view  of  the  whole ;  fig,  1050  is  a  section  through  the  middle  of  the  former  figure, 
in  the  course  of  its  operation.  The-brick  furnace,  strengthened  with  iron  bands,  i,  d, 
5,  7,  8,  has  in  its  interior  (see  fig- 1050.)  a  nearly  ege-shaped  space  b,  provided  with 
the  following  openings  :  beneath  is  the  fire-hearth,  c,  with  a  round  mouth,  an-  opposite 
are  the  smoke  flue  and  chimney,  d;  in  the  slanting  front  of  the  furnace  is  a  lai^e  open- 
ing, E,  /iff.  1049.  Beneath  are  two  smaller  oblong  rectangular  orifices,  f,  g,  which 
extend  somewhat  obliquely  into  the  laboratory,  b.  h  serves  for  introducing  the  wood 
into  the  fireplace.  All  these  four  openings  are,  as  shown  in  ^ig.  1049,  secured  from 
iniury  by  iron  mouth-pieces.  The  wood  is  burned  upon  an  iron  or  clay  bottom  piece,  r. 
A  semi-circular  cover,  n,  closes  during  the  operation  the  large  opening,  e,  which  at 
other  times  remains  open.  By  means  of  a  hook,  m,  and  a  cham,  which  rests  upon  a 
hollow  arch,  h,  the  cover,  n,  is  connected  with  the  front  end  of  the  long  iron  lev  er,  R,  k  . 
A  prop  supports  at  once  the  turning  axis  of  this  lever  and  the  catch,  6,  c ;  the  weight, 
Q  draws  the  arm  b  down,  and  thereby  holds  up  nj  e  therefore   remains  open.     By 


rods  on  the  back  wall,  t,  t,  the  hook  i,  in  which  r'  rests,  proceeds  from/.  When  r' 
is  raised  r  sinks.  The  catch  c  b,  enters  with  its  front  tooth  into  a  slanting  notch  upon 
the  upper  edge  of  r,  spontaneously  by  the  action  of  the  spring  e  ;  whereby  the  opening; 
K,  is  shut  The  small  door  n,  rises  again  with  the  front  arm  of  the  lever  by  the  oper- 
ation of  the  weight  q  of  itself,  as  soon  as  the  catch  is  released  by  pressure  upon  c. 

The  most  important  part  of  the  whole  apparatus  is  the  drum,  k,  for  the  reception 
and  rounding  of  the  bits  of  glass.     It  may  be  made  of  strong  copper,  or  of  hammered 

or  cast  iron  quite  open  above,  and 
pierced  at  the  bottom  with  a  square 
hole,  into  which  the  lower  end  of 
the  long  rod,  t,  is  exactly  fitted,  and 
secured  in  its  place  by  a  screwed 
collector  nut     The  blunt  point,  x, 
{Jig,  1049.)  rests  during  the  work- 
ing in  a  conical  iron  step  of  the 
laboratory,/^.  1050.   On  the  mouth 
of  the  drum  k,  a  strong  iron,  ring 
is  fixed,  having  a  bar  across  its  dia- 
meter, with  a  square  hole  in  its 
middle  point,  fitted  and  secured  by 
a  pin  to  the  rod  t,  and  turned  by 
its  rotation.     The  vessel  k,  and  its 
axle  t,  are  laid  in  a  slanting  direc- 
tion ;  the  axle  rests  in  the  upj>er 
ring,  2,   at  the  lower  end  of  the 
rod,  /,  of  which  the  other  end  is 
hung   to   the   hook,    w,    upon    the 
mantel  beam,  n.     On  the  upper  end 
of  t,  the  handle,  s,  is  fixed  for  turn- 
ing round  continuously  the  vessel, 
K,  while  the  fire  is  burning  in  the 
furnace,  the  fuel  being  put  not  only 
in  its  bottom  chamber,  but  also  into 
the  holes,  F,  o  {fg.   1049).       The 
fire-wood  is  made  very  dry  before 
.,     .        ,         «  , «  , ,        ,       ,  being  used,  by  piling  it  in  logs  upon 

the  iron  bars,  2,  10,  11,  under  the  manteli)ieeo,  as  shown  in /^«,  1049,  1050. 

After  the  operation  is  finished,  and  the  cover,  n,  is  removed,  the  drum  u  emptied  of 
Its  contents,  as  follows.  Upon  the  axle,  /,  there  is  toward  k  a  projection  at  «.  Alonir. 
side  the  furnace  (/g.  1049)  there  is  a  crane,  m,  that  turns  upon  the  step  ,,  ,,  on  the 
ground.  The  upper  pivot  turns  in  a  hole  of  the  mantel-beam,  f(.  Upon  the  perpen- 
aicular  arm,  w,  of  the  crane  there  is  a  hook,  y,  and  a  ring,  <?,  in  which  the  iron  rod,  «.  ' 
IS  moveable  in  all  directions.  When  the  drum  is  to  be  removed  from  the  furnace  the 
crane,  with  its  arm,  w,  must  be  turned  inward,  the  under  hook  of  the  rod,  p,  is  to  be 
hung  m  the  projecting  piece,  tt,  and  the  rod,  /,  is  lifted  entirely  out.     After  this   bv 

Srnl!th°^),       Trf '  '  r^^K^"""  '^"  ^^  ?'^^"  ^^^^  '^^  '^'  ^»  «"t  «f  the  furnace  ;  and 

to  thP^Sr  ,m  "^""v  \fJ^l  """"u'  ^"1'^'  P^'^"'  P'  ^'  «"y  ^^^''^^  Position  can  be  given 
to  the  drum  Fxg.  1049  shows  how  the  workman  can  with  his  hand  applied  to  I'  de- 
press the  axle,  ^  and  thereby  raise  the  drum,  k,  so  high  that  it  will  empty  itself  into 

,nH^hV  f '  P^Th^  **""'"'\    ^^'"^  ^^'\  'V'''^^^  '^'  ^'""^  «"  the  contrary  hangs  nearly 

upright  upon  the  crane  by  means  of  the  rod,  ;,,  and  may  therefore  be  eafily  filled 

again  in  this   position      The  manner  of  bringing  it  into  the  proper  position  in  the 

furnace  by  means  of  the  crane  and  the  rod,  /,  is  obvious  from  fig.  1050. 

The  now  well-rounded  beads  are  separated  from  the  pulverulent  substance  with 

rnMln'/Hr'^  mixed,  by  careful  agitation  in  sieves;  aid  they  are  polished  fin^y 
and  cleaned  by  agitation  in  canvass-bags.  j  i-^       ^«  xuiaujf 

PEARL  BUTTONS.  Pearl-button  making  is  thus  practised;  the  blanks  are  cut 
out  of  the  shell  bv  means  of  a  small  revolving  steel  tube,  the  edge  of  which  is  toothed  as 
a  saw,  after  which  they  are  flattened  or  reduced  in  thickness  by  splitting,  which  is  aided 
by  the  laminar  structure  of  the  shell.  At  this  stage  being  hefd  in  a  spring  chuck,  they 
are  finished  on  both  sides  by  means  of  a  small  tool :  the  drilling  is  efi-ected  by  the  revo- 
lution of  a  sharp  steel  instrument,  which  acts  with  great  rapidity.  Ornamental  cut- 
tings are  produced  by  means  of  small  revolving  cutters,  and  the  final  brilliant  polish 
IS  given  by  tne  friction  of  rotten-stone  and  soft  soap  upon  a  revolving  bench. 

PEARL  WHITE  is  a  submuiiaie  of  bismuth,  oblaineU  by  pouring  a  solution  ol  the 
nitrate  of  that  metal  into  a  dilute  solution  of  sea-salt,  whereby  a  light  and  very  while 
powder  is  obtained,  which  is  to  be  well  washed  and  dried.     See  Bismuth. 


364 


PELTRY. 


PENCIL  MANUFACTURE. 


365 


PECT  C  ACID  (^cidepecttque,  Fr. ,   GaUerUaure,  Germ.),  so  named   on  account 
of  itsjellymg  property,  from  ,r,.nf,  coagWum,  exists  in  a  vast  number  of  vegetables. 
The  easiest  way  of  preparing  ,t,  is  to  grate  the  roots  of  carrots  into  a  pulp,  to  express 
their  juice,  to  wash  the  marc  with  rain  or  distilled  water,  and  to  squeeze  it  well ;  60 
parts  of  the  marc  are  next  to  be  diffused  through  300  of  rain-wallr,  adding  by  slow 
degrees  a  solution  of  one  part  of  pure  potash,  or  two  of  bicarbonate!     This  mixture 
'L  ?K      ^'^^if^' '^  f  ^  ^  °»«d«,  to  boil  for  about  a  quarter  of  an  hour,  and  is  then  to 
be  thrown  boUmg-hot  upon  a  filter  cloth.     It  is  known  to  have  been  well  enough 
boiled  when  a  sample  of  the  filtered  liquor  becomes  gelatinous  by  neutralizing  it  with 
an  acid.     This  liquor  contams  pectate  of  potassa,  in  addition  to  other  matters  extricated 
Irom  the  root.     1  he  pectate  may  be  decomposed  by  a  stronger  acid,  but  it  is  better  to 
decompose  it  by  muriate  of  lime ;  whereby  a  pectate  of  lime,  in  a  gelatinous  form  quite 
•"?  w  l^",  T-^^""'  '^  o^t^i^^-     This  having  been  washed  with  cold  water  upon  a  doth 
is  to  be  boded  ;n  water  containing  as  much  muriatic  acid  as  will  saturate  the  lime     The 
pectic  acid  thus  h5»crated,  remains  under  the  form  of  a  colorless  jelly,  which  reddens  lit- 
mus paper,  and  tastes  sour,  even  after  it  is  entirely  deprived  of  the  muriatic  acid      Cold 
water  dissolves  very  little  of  it ;  it  is  more  soluble  in  boiling  water.     The  solution  is 
colorless,  does  not  coagulate  on  cooling,  and  hardly  reddens  litmus  paper :  but  it  gelatini- 
zes  when  alcohol,  acids,  alkalis,  or  salts  are  added  to  it.    Even  sugar  transforms  it  after 
some  time,  into  a  gelatinous  state,  a  circumstance  which  serves  to  explain  the  preparation 
ol  apple,  cherry,  raspberry',  gooseberry,  and  other  jellies. 

PECTINE,  or  vegetable  jelly,  is  obtained  by  mixing  alcohol  with  the  juice  of  ripe 
currants,  or  any  similar  fruit,  till  a  gelatinous  precipitate  takes  place :  which  is  to  be 
gently  squeezed  in  a  cloth,  washed  with  a  little  weak  alcohol,  and  dried.  Thus  pre- 
pared, pectme  is  msipid,  without  action  upon  litmus,  in  small  pieces,  semi-transparent, 
and  of  a  membranous  aspect,  like  isinglass.  Its  mucilaginous  solution  in  cold  water  is 
not  tinged  blue  with  lodme.  A  very  small  addition  of  potash,  or  its  carbonate,  converts 
pectme  into  pectic  acidj  both  of  which  substances  are  transformed  into  mucic  and  oxalic 
acids  by  the  nitric. 

««^^^PT  (Pe//«<m>,  Tt.'  Pelzwerk,  Germ.),  is  nearly  synonymous  with  fur,  and 

comprehends   the   skins  of  different  kinds  of  wild   animals   that  are   found   in   high 

northern  latitudes,  particularly  in  the  American  continent ;  such  as  the  beaver  bear 

moosedeer,  marten,  mink,  sable,  wolverine,  wolf,  &c.     When  these  skins  have  received 

no  preparation  but  from  the  hunters,  they  are  most  properly  called  peltry  ;  but  when  they 

have  had  the  inner  side  tawed  or  tanned  (see  Leathek)  by  an  aluminous  process,  they 

may  then  be  denominated /ttr*.  '       ' 

The  scouring  or  cleaning  of  peltry  is  performed  in  a  large  cask,  or  truncated  cone 

laid  on  Its  side,  and  traversed  by  a  revolving  shaft,  which  is  furnished  with  a  few 

rectangular  rounded  pegs.     These  are  intended  to  stir  round  the  skins,  while  they  are 

dusted   over   with  Paris  plaster,  whitening,  or  sometimes  sand,  made  as  hot  as  the 

hand  can  bear.     The  bottom  of  the  cask  should  be  grated,  to  allow  the  impurities  to 

lall  out.     The  lustrage,  which  the  cleansed  skins  next  undergo,  is  merely  a  species  of 

dyein?  either  topical,  to  modify  certain  disagreeable  shades,  or  general,  to  impart  a  more 

beautiful  color  to  the  fur.     Under  the  articles  Dyeing,  and  the  several  colors,  as  also 

Hair  and  Morocco,  sufficient  instructions  will  be  found  for  dveing  fur.     The  mordants 

should  be  applied  pretty  hot  by  a  brush,  on  the  hair  of  the  skin,  sketched  upon  a  solid 

table  ;  and  after  two  or  three  applications,  with  drying  between,  the  tinctorial  infusions 

may  be  rubbed  on  m  the  same  way.     The  hair  must  be  freed  beforehand  from  all  greasi- 

ness,  by  lime  water,  or  a  weak  solution  of  carbonate  of  soda ;  then  well  washed      Much 

nicety,  and  many  successive  applications  of  the  dye-stuff,  are  sometimes  requisite  to  brine 

out  the  desired  shade.  """8 

Under  Hat  Manufacture,  I  referred  to  this  article  for  a  description  of  the  process 
of  «6cre/age,  whereby  the  hairs  of  rabbit  and  hare  skins  are  rendered  fit  for  felting 
Dissolve  32  parts  of  quicksilver  in  500  of  common  aquafortis;  and  dilute  the  solution 
with  one  half  or  two  thirds  of  its  bulk  of  water,  according  to  the  strength  of  the  acid. 

K^^ti       r  !1"^  *?'.'*  ^P*""  ^  **^^^  "^'^^  ^^^  ^*^''  ^'^«  uppermost,  a  brush,  made  with  the 

bristles  of  the  wild  boar,  is  to  be  slightly  moistened  with  the  mercurial  solution,  and 

passed  over  the  smooth  surface  of  the  hairs  with  strong  pressure.     This  application 

?     u  A     ''T.^If    ^^^^''^l  t'^nes  in  succession,  till  every  part  of  the  fur  be  equally 

touched,  and    ill  about  two  thirds  of  the  length  of  the  hairs  be  moistened,  or  a  little 

more,  should  they  be  rigid.    In  order  to  complete  this  impregnation,  the  skins  are  laid 

together  ui  pairs  with  the  hairy  sides  in  contact,  put  in  this  state  into  the  stove-room. 

jind  exposed  to  a  h«it  higher  in  proportion  to  the  weakness  of  the  meicnrial  solution. 

The  dr)'ing  should  be  rapidly  effected,  otherwise  the  concentration  of  the  nitrate  will  not 

take  due  effect  in  causing  the  retraction  and  curling  of  the  hairs. 

No  other  acid,  or  metallic  solution,  but  the  above,  has  been  found  to  answer  the  de 


Sired  purpose  of  the  hatmaker.  After  the  hairs  are  properly  secreled,  they  are  plucked 
off  by  hand,  or  shorn  off  by  a  machine. 

PENCIL  MANUFACTURE.  {Crayms.fahnque  de,  Fr.;  Bleistifte,  verfertigung, 
Germ.)  The  word  pencil  is  used  in  two  senses.  It  signifies  either  a  small  hair  brush 
employed  by  painters  in  oil  and  water  colors,  or  a  slender  cylinder,  of  black  lead  or  plum- 
bago, either  naked  or  enclosed  in  a  wooden  case,  for  drawing  black  lines  upon  paper. 
The  last  sort,  which  is  the  one  to  be  considered  here,  corresponds  nearly  to  the  French 
term  crayon,  though  this  includes  also  pencils  made  of  differently  colored  earthy  compo- 
sitions.    See  Crayon. 

The  best  black-lead  pencils  of  this  country  are  formed  of  slender  parallelopipeds,  cut 
out  by  a  saw  from  sound  pieces  of  plumbago,  which  have  been  previously  calcined  in  close 
vessels  at  a  bright  red  heat.  These  parallelopipeds  are  generally  enclosed  in  cases  made 
of  cedar  wood,  though  of  late  years  they  are  also  used  alone,  in  peculiar  pencil-cases, 
under  the  name  of  ever-pointed  pencils,  provided  with  an  iron  wire  and  screw,  to  pro- 
trude a  minute  portion  of  the  plumbago  beyond  the  tubular  metallic  ease,  in  proportion 
as  it  is  wanted. 

In  the  year  1795,  M.  Conte,  a  French  gentleman,  well  acquainted  with  the  mechanical 
arts,  invented  an  ingenious  process  for  making  artificial  black-lead  pencils  of  superior 
quality,  by  which  he  and  his  successor  and  son-in-law,  M.  Humblot,  have  realized  large 
fortunes. 

Pure  clay,  or  clay  containing  the  smallest  proportion  of  calcareous  or  silicious  matter, 
is  the  substance  which  he  employed  to  give  aggregation  and  solidity,  not  only  to  plum- 
bago dust,  but  to  all  sorts  of  colored  powders.  That  earth  has  the  property  of  diminish- 
ing in  bulk,  and  increasing  in  hardness,  in  exact  proportion  to  the  degree  of  heat  it  is 
exposed  to,  and  hence  may  be  made  to  give  every  degree  of  solidity  to  crayons.  The 
clay  is  prepared  by  diffusing  it  in  large  tubs  through  clear  river  water,  and  letting  the 
thin  mixture  settle  for  two  minutes.  The  supernatant  milky  liquor  is  drawn  off  by  a 
syphon  from  near  the  surface,  so  that  only  the  finest  particles  of  clay  are  transferred  into 
the  second  tub,  upon  a  lower  level.  The  sediment,  which  falls  very  slowly  in  this  tub, 
is  extremely  soft  and  plastic.  The  clear  water  being  run  off,  the  deposite  is  placed  upon 
a  linen  filter,  and  allowed  to  dry.     It  is  now  ready  for  use. 

The  plumbago  must  be  reduced  to  a  fine  powder  in  an  iron  mortar,  then  put  into  a 
crucible,  and  calcined  at  a  heat  approaching  to  whiteness.  The  action  of  the  fire  gives 
it  a  brilliancy  and  softness  which  it  would  not  otherwise  possess,  and  prevents  it  from 
being  affected  by  the  clay,  which  it  is  apt  to  be  in  its  natural  state.  The  less  clay  is 
mixed  with  the  plumbago,  and  the  less  the  mixture  is  calcined,  the  softer  are  the  pencils 
made  of  it ;  the  more  clay  is  used  the  harder  are  the  pencils.  Some  of  the  best  pencils 
made  by  M.  Conte,  were  formed  of  two  parts  of  plumbago  and  thiee  parts  of  clay  ;  others 
of  equal  parts.  This  composition  admits  of  indefinite  variations,  both  as  to  the  shade  and 
hardness ;  advantages  not  possessed  by  the  native  mineral.  While  the  traces  may  be 
made  as  black  as  those  of  pure  plumbago,  they  have  not  that  glistening  aspect  which 
often  impairs  the  beauty  of  black-lead  drawings.  The  same  lustre  may,  however,  be  ob- 
tained by  increasing  the  proportion  of  powdered  plumbago  relatively  to  the  clay. 

The  materials  having  been  carefully  sifted,  a  little  of  the  clay  is  to  be  mixed  with  the 
plumbago,  and  the  mixture  is  to  be  triturated  with  water  into  a'perfectly  uniform  paste. 
A  portion  of  this  paste  may  be  tested  by  calcination.  If  on  cutting  the'  indurated  mass! 
particles  of  plumbago  appear,  the  whole  must  be  further  levigated.  The  remainder  of 
the  clay  is  now  to  be  introduced,  and  the  paste  is  to  be  ground  with  a  muller  upon  a 
porphyry  slab,  till  it  be  quite  homogeneous,  and  of  the  consistence  of  thin  dough.  It  is 
now  to  be  made  into  a  ball,  put  upon  a  support,  and  placed  under  a  bell  glass  inverted  in 
a  basin  of  water,  so  as  to  be  exposed  merely  to  the  moist  air. 

Small  grooves  are  to  be  made  in  a  smooth  board,  similar  to  the  pencil  parallelopipeds, 
but  a  little  longer  and  wider,  to^Uow  for  the  contraction  of  volume.    The  wood  must  be 
boiled  m  grease,  to  prevent  the  paste  from  sticking  to  it.    The  above  described  paste 
being  pressed  with  a  spatula  into  these  grooves,  another  board,  also  boiled  in  grease,  is 
to  be  laid  over  them  very  closely,  and  secured  by  means  of  screw-clamps.    As  the  atmo- 
spheric air  can  get  access  only  to  the  ends  of  the  grooves,  the  ends  of  the  pencil-pieces 
become  dry  first,  and  by  their  contraction  in  volume  get  loose  in  the  grooves,  allowing 
the  air  to  insinuate  further,  and  to  dry  the  remainder  of  the  paste  in  succession.     When 
Uie  whole  piece  is  dned,  it  becomes  loose,  and  might  be  turned  out  of  the  grooves. 
But  before  this  is  done,  the  mould  must  be  put  into  an  oven  moderately  heated,  in 
order  to  render  the  pencil  pieces  still  drier.     The  mould  should  now  be  taken  out,  and 
emptied  upon  a  table  covered  with  cloth.    The  greater  part  of  the  pieces  will  be 
entire,  and  on.y  a  few  will  have  been  broken,  if  the  above  precautions  have  been  dult 
observed.    They  are  all,  however,  perfectly  straight,  which  is  a  matter  of  the  first  im- 
portance. 

In  order  to  give  solidity  to  these  pencils,  they  must  be  set  upright  in  a  crucible  till 


-•^■ 


Ut 


see 


PENS,  STEEL. 


PEPPER. 


367 


u 


H  is  filled  with  them,  and  then  surrounded  with  charcoal  powder,  fine  sand,  or  sifted 
wood  ashes.  The  crucible,  after  having  a  luted  cover  applied,  is  to  be  put  into  a  ft^rnace, 
and  exposed  to  a  decree  of  heat  regulated  by  the  pyrometer  of  Wedgewood ;  which 
de<-ree  is  proportional  to  the  intended  hardness  of  the  pencils.  When  they  have  been 
thus  baked,  the  crucible  is  to  be  removed  from  the  fire,  and  allowed  to  cool  with  the 

pencils  in  it.  .  .  ,    ,  -  ^      i-  ^ 

Should  the  pencils  be  intended  for  drawing  architectural  plans,  or  for  very  fine  lines, 
they  must  be  immersed  in  melted  wax  or  suet  nearly  boiling  hot,  before  they  are  put  into 
the  cedar  cases.  This  immersion  is  best  done  by  heating  the  pencils  first  upon  a  grid-iron, 
and  then  plunging  them  into  the  melted  wax  or  tallow.  They  acquire  by  this  means  a 
certain  degree  of  softness,  are  less  apt  to  be  abraded  by  use,  and  preserve  their  points 

much  better.  ,      , .  .  .  u    v    i-       *i. 

When  these  pencils  are  intended  to  draw  ornamental  subjects  with  much  shading,  they 

should  not  be  dipped  as  above.  ,...«.      ^^        ,.  .-  ah 

Secoiui  process  for  making  artificial  pencih,  somewhat  different  from  the  precedmg.---A\l 
the  operations  are  the  same,  except  that  some  lamp-black  is  introduced  along  with  the 
plumbago  powder  and  the  clav.  In  calcining  these  pencils  in  the  crucible,  the  contact 
of  air  must  be  carefully  excluded,  to  prevent  the  lamp-black  from  being  burned  away  on 
the  surface.  An  indefinite  variety  of  pencils,  of  every  possible  black  tint,  may  thus  be 
produced,  admirably  adapted  to  draw  from  nature. 

Another  ingenious  form  of  mould  is  the  following :  . 

Models  of  the  pencil-pieces  must  be  made  in  iron,  and  stuck  upright  upon  an  iron  tray, 
having  edges  raised  as  hi-h  as  the  intended  length  of  the  pencils.  A  metallic  alloy 
is  made  of  tin,  lead,  bismuth,  and  antimony,  which  melts  at  a  moderate  heat.  This  is 
poured  into  the  sheet-iron  tray,  and  after  it  is  cooled  and  concreted,  it  is  inverted, 
and  shaken  off  from  the  model  bars,  so  as  to  form  a  mass  of  metal  perforated  throughout 
with  tubular  cavities,  corresponding  to  the  intended  pencil-pieces.  The  paste  is  in- 
troduced by  pressure  into  these  cavities,  and  set  aside  to  dry  slowly.  When  nearly  dry, 
the  pieces  get  so  much  shrunk  that  they  may  be  readily  turned  out  of  the  moulds  upon  a 
cloth  table.  They  are  then  to  be  completely  desiccated  in  the  shade,  afterwards  in  a 
stove-room,  next  in  the  oven,  and  lastly  ignited  in  the  crucible,  with  the  precautions  above 

M.  Conte  recommends  the  hardest  pencils  of  the  architect  to  be  made  of  lead  melted 
with  some  antimony  and  a  little  quicksilver.  a  4V.  *  *r. 

In  their  further  researches  upon  this  subject,  M.  Conte  and  M.  Humblot  lound  that  the 
different  degrees  of  hardness  of  crayons  could  not  be  obtained  in  a  uniform  manner  ^y  the 
mere  mixture  of  plumbago  and  clay  in  determinate  doses.  But  they  discovered  a  remedy 
for  this  defect  in  the  use  of  saline  solutions,  more  or  less  concentrated,  into  which  they 
plunged  the  pencils,  in  order  to  modify  their  hardness,  and  increase  the  uniformity  of  their 
texture.  The  non-deliquescent  sulphates  were  preferred  for  this  purpose ;  such  as  sul- 
phate of  soda,  &c.     Even  sirup  was  found  useful  in  this  way.  .  ^  ^ 

Messrs.  Stevens  and  Wylder's  pencils,  pens,  and  pen  AoW^a— Messrs.  Stevens  A  Wylder 
obtained  a  patent  in  June,  1850,  for  certain  improvements,  in  which  they  claini, 

1  (In  respect  of  ever  pointed  pencils.)  The  employment  of  an  internal  helix  in 
lieu  of  a  propelling  screw,  by  means  of  which  a  length  of  black  lead,  chalk,  or  other 
marking  materials  may  be  propelled  nearly  the  whole  length  of  the  pencil. 

2.  (With  reference  to  pens.)  The  application  of  gutta  percha  to  metal  pens,  be- 
tween the  shoulder  and  the  nibs,  the  metal  having  been  farst  reduced  m  thickness, 
either  bv  grinding  or  otherwise,  for  the  purpose  of  obtaining  greater  flexibility. 
2ndlv  The  construction  of  barrel  and  other  pens  in  metal,  to  be  used  with  fountain  pen 
holders,  having  the  ban-el  placed  the  reverse  way,  or  above  instead  of  below  the  nibs. 

3.  (With  respect  to  penholders.)  Ist.  The  use  and  application  of  glass  to  telescopic 
and  other  fountain  holders,  whereby  the  ink  is  kept  from  contact  with  metal  until  it 
reaches  the  pen.  (Query,  has  not  this  been  anticipated  by  Mr.  Thomson  s  patent?) 
2ndly.  The  adaptation  of  a  band  of  flexible  material  to  fountain  holders,  for  the  pur- 
pose of  facilitating  the  flow  of  ink  to  the  pen,  such  band  being  placed  around  a  part 
of  the  tube,  in  which  air  holes  or  openings  have  been  previously  made. 

PENS  STEEL.  The  best  metal,  made  from  Dannemora  or  hoop  (l)  iron,  is  selected 
and  laminated  into  slips  about  3  feet  long,  and  4  inches  broad,  of  a  thickness  corre- 
sponding to  the  desired  stiffness  and  flexibility  of  the  pens.  These  slips  are  subjected 
to  the  action  of  a  stamping-press,  somewhat  similar  to  that  for  making  buttons.  (See 
Button  and  Plated  Ware.)  The  point  destined  for  the  nib  is  next  introduced  into  an 
appropriate  gauged  hole  of  a  little  machine,  and  pressed  into  the  semi-cylindncal 
shape  •  where  it  is  also  pierced  with  the  middle  slit,  and  the  lateral  ones,  provided  the 
latter  are  to  be  given.  The  pens  are  now  cleaned,  by  being  tossed  about  among  each 
other  in  a  tin  cylinder,  about  3  feet  long,  and  9  inches  in  diameter;  which  is  suspended 
at  each  end  upon  joints  to  two  cranks,  formed  one  on  each  of  two  shafts.    The  cylm- 


•3er,  by  the  rotation  of  a  fly-wheel,  acting  upon  the  crank-shafts,  is  made  to  describe 
such  revolutions  as  agitate  the  pens  in  all  directions,  and  polish  them  by  mutual  attri- 
tion. In  the  course  of  4  hours  several  thousand  pens  may  be  finished  upon  this  machine. 
When  steel  pens  have  been  punched  out  of  the  softened  sheet  of  steel  by  the  appro- 
priate tool,  fashioned  in  the  desired  form,  and  hardened  by  ignition  in  an  oven  and 
sudden  quenching  in  cold  water,  they  are  best  tempered  by  being  heated  to  the  re- 
quisite spring  elasticity  in  an  oil  bath.  The  heat  of  this  bath  is  usually  judged  of  by 
the  appearance  to  the  eye ;  but  this  point  should  be  correctly  determined  by  a  ther- 
mometer, according  to  the  scale  (see  Steel);  and  then  the  pens  would  acquire  a 
definite  degree  of  flexibility  or  stiffness,  adapted  to  the  wants  and  wishes  of  the  con- 
sumers.    They  are  at  present  tempered  too  often  at  random. 

Gillott,  Joseph^  Victoria  Works,  Birmingham,  Inventor  and  Manufa^iturer.    Specimen* 
of  metallic  pern.     Steel  pen  making  may  be  briefly  described  as  follows :     The  steel  is 
procured  at  Sheffield ;  it  is  cut  into  strips,  and  the  scales  removed  by  immersion  in 
pickle  com.posed  of  dilute  sulphuric  acid.     It  is  passed  through  rollers,  by  which  it  is 
reduced  to  the  necessary  thickness ;  it  is  then  in  a  condition  to  be  made  into  pens,  and 
is  for  this  purpose  passed  into  the  hands  of  a  girl,  who  is  seated  at  a  press,  and  who  by 
means  of  a  bed  and  a  punch  corresponding  speedily  cuts  out  the  blank.    The  next 
stage  is  piercing  the  hole  which  terminates  the  slit  and  removing  any  superfluous  steel 
likely  to  interfere  with  the  elasticity  of  the  pen ;  at  this  stage  they  are   annealed  in 
quantities  in  a  muffle,  after  which  by  means  of  a  small  stamp  the  maker's  name  is  im- 
pressed upon  them.     Up  to  this  stage  the  future  pen  is  a  flat  piece  of  steel :  it  is  then 
transferred  to  another  class  of  workers,  who  by  means  of  the  press  make  it  concave,  if 
a  nib,  and  form  the  barrel,  if  a  barrel  pen.     Hardening  is  the  next  process :  to  effect 
this  a  number  of  pens  are  placed  in  a  small  iron  box  and  introduced  into  a  muffle ;  after 
they  become  of  a  uniform  deep  red,  they  are  plunged  into  oil ;  the  oil  adhering  is  re- 
moved by  agitation  in  circular  tin  barrels.     The  process  of  tempering  succeeds ;  and 
finally  the  whole  are  placed  in  a  revolving  cylinder  with  sand,  pounded  crucible,  or 
other  cutting  substances,  which  finally  brightens  them  to  the  natural  colour  of  the  ma- 
terial.    The  nib  is  ground  with  great  rapidity  by  a  girl  who  picks  it  up,  places  it  in  a 
pair  of  suitable  plyers,  and  finishes  it  with  a  single  touch  on  a  small  emery  wheel 
The  pen  is  now  in  a  condition  to  receive  the  slit,  and  this  is  also  done  by  means 
of  a  press ;  a  chisel  or  wedge  with  a  flat  side  is  fixed  to  the  bed  of  the  press ;  the  de- 
scending screw  has  a  corresponding  chisel  cutter,  which  passes  down  with  the  minutest 
accuracy;  the  slit  is  made ;  and  the  pen  is  completed.     The  last  stage  is  colouring 
brown  or  blue  ;  this  is  done  by  introducing  the  new  pens  into  a  revolving  metal  cylin- 
der, under  which  is  a  charcoal  stove,  and  watching  narrowly  when  the  desired  tint  is 
arrived  at.     The  brilliancy  is  imparted  by  means  of  lac  dissolved  in  naphtha ;  the  pens 
are  immersed  in  this,  and  dried  by  heat     Then  follow  the  counting  and  selecting. 
Women  are  mostly  employed  in  the  manufacture,  with  skilled  workmen  to  repair  and 
set  the  tools.     This  exhibitor  employs  upwards  of  five  hundred  hands,  of  which  four- 
fifths  are  women.     The  manufactory  has  been  established  upwards  of  thirty  years, 
and  has  been  the  means  of  introducing  many  improvements  in  the  manufacture. 

Wiley,  W.  E.  <Sc  Co.,  84  Great  Hamvton  Street,  Birmingham — Manufacturer.  Speci- 
mens of  gold,  palladium,  ^old  and  silver,  and  silver  pens,  pointed  with  the  native 
alloys  of  iridium  and  osmium,  the  hardest  of  metals. 

These  pens,  being  formed  of  metals  not  acted  on  by  the  ink,  appear  almost  indes- 
tructible; their  permanence  in  use  is  further  maintained  by  the  attachment  to  the 
Eoint,  by  soldering,  of  a  minute  portion  of  the  metals  named,  which  are  extremely 
ard  and  durable. 

Hincks,  Wells,  <b  Co.,  Buckingham  street,  Birmingham — Manufacturers.  Patent  self- 
acting  cutting,  piercing,  and  raising  pen  machine.  The  ordinary  presses  are  worked 
by  hand.  The  self-acting  machines  are  driven  by  steam;  they  cut,  pierce,  and  side 
sht  two  pens  at  one  stroke,  performing  six  processes  at  once. 

Specimens  of  liliputian  pens  complete,  intended  to  show  the  skill  of  the  tool  cutter 
and  the  perfection  of  the  machinery  employed.  A  gross  of  the  smallest  weighs  less 
than  34  grains,  and  can  be  contained  in  a  barcelona  nutshell. 

Specbnens  of  finished  pens.  Steel  in  its  rough  state,  and  after  it  has  passed  through 
the  rolling-mill ;  scrap  steel  from  which  the  pens  are  cut;  pens  cut  and  pierced.  The 
other  processes  exhibited  in  the  finished  pen. 

Specimens  of  pierced  pens,  to  show  the  modern  improvements  in  the  art  of  tool- 
cutting. 

PEPPER,  {Poivre,  Fr. ;  Pfeffer,  Germ.),  Black  pepper  is  composed,  according  to 
M.  Pelletier,  of  the  vegetable  principle,  piperine,  of  a  very  acrid  concrete  oil,  a  volatile 
balsamic  oil,  a  coloured  gumy  matter,  an  extractive  principle  analogous  to  legumine, 
malic  and  tartaric  acids,  starch,  bassorine,  ligneous  matter,  with  earthy  and  alkaline 
salts  in  small  quantity.     Cubebs  pepper  has  nearly  the  same  composition. 


1  fw 

111! 


3gg  PERFUMERY,  ART  OF. 

PEPPER.  v^j:^f,^^\?\:ri^:r^To.^  ^^-'^^^^^i 

of  lime,  subsequent  washing  and  ^P  •'^^ '  f  P.'^^'j'X  na^^^^^  this  substance  some- 
not  theiV  flavor.  I  was  F^^^^^^Y^Jf  .^^^^^^^^^  inves  fgate  a  sample  of  ground 
what  minutely,  from  bemg  called   Professionally  o  ^^J^^  London,  which  pepper 

white  pepper  belonging  to  an  ^"Jl^X^har^e  of  its  being  adulterated,  or  mixed  with 
had  been  seized  by  the  Excise  on  the  charge  o^  eompamfive  analysis  of  that  pepper 
some  foreign  matter,  contrary  to  law.     I  made  a  comp  j  ^.^    .^  ^^^ 

and  of  genuine  white  P^PPf  ^<=o"»«^  \"d^,  ^°"^"^^^^^^  about  8|  grains  of  a 

grains,  a  trace  of  volatile  oil,  in  which  the  a^om^^^^^^^  Sne;  about  60  grains  of 
^ungekt  resin,  containing  a  small  faction  of  a  g^^^^^^^J^^^        i„  hot  Ind  cold 

starch,  with  a  little  gum,  and  nearly  30  gj^"^«  f  ^^^^^^^^^^  ^^'Z  service  of  the  Excise 
water  which  may  ^f '^^^^^^d  lignine.  J^he  l^wo  c^^^^^^      ml        ^^^^^.^^^  ^  ^^^^^j^ 

made  oath  before  the  court  of  i^'^'^^^^J^'^'"'^^^^^ 

proportion  of  sago,  even  to  the  amount  ol  f'^Wy    ^  per  J^^^-  «  5           ^        ^j^^ 

Sponthe  appearance  of  certain  rounded  Pf  ^J^f^^^  V^^^^^  No  allegation  could 

color  which  these  assumed  when  "^J^^^^^^^^JJ^^^i.^^^^^^  acquire  as  deep  a 

be  more  frivolous.     Bruised  corns  of  f^Xwhatevef^  B^^^^^^  characters   of  sago, 

tint  with  iodine   as  any  species  of  starch  whatever,    ^m  i  ^^^^            _ 

optical  and  chemical,  are  so  peculiar,  as  to  render  ^^  ,^^Ycr^^^ 

^e^rous,  than  the  prosecution  of  respectable  merchan^^  ^^  ^  ^^^^^^^^  ^^ 

A  particle  of  sago  appears  in  the  i°^f  o^^^Pf' ^JJ,^^^^^^^ 

corns  did.  .       •        ij  ^^ter,  swells  and  softens  into  a 

Moreover,  sago,  steeped  for  a  s^^rt  tune  ^^^  J^^^^  ^ ^^  '  ,^nded  by  attrition  m 
pulpy  consistence,  whereas  the  P"^«L^f  ,,°^^>^^^^^^  Tnd  dimensions.  Sago,  being 
the  mill,  retain,  in  like  circumstances,  ^J^^^j^^^f^X  ,^  palm  in  a  damp  state,  upon 
pearled  by  heating  and  stirring  the  ^^^ J  ""'^^^^^^^^^^  aggregation  and  brilliant 

bac?.  lilUnVp"  sU^^tn's^^^^^^^^^  -'  '-^' 

" Vhf ESaTs'arsufficiently  odious  and  oppressive  in  themselves  without  being 
aggravated  by  the  servile  sophistry  of  pseudo-science.  ^^  ^^^ 

'^lour  pounds  of  ^ack  pepper  y  eld  ^^^^^^^^^ 

led  from  it  afterward,  by  potash. 


Imported. 

lbs. 
8,082,319 
3,99G,496 


Retained  for  Con- 
Bumptioa. 


lbs. 
3,174,425 
3,303,402 


Exported. 

lbs. 
3,'727,183 
2,709,755 


Duty  received. 


£ 
83,324 
86,729 


PERCUSSION  CAPS.  Pa*«..    ^^^YtsS^^tr^-^"^- 
ing  guns  in  Europe  may  be  «f'"»'4**VoA^'ZtiIyot  copper  requisite  for  ite 
portance  of  this  article  may  be  f"™^*;™" 'j  Xantages  of  the  percussion  princi- 
production,  yiz.  396,000  lbs.  weight      The  f/^*''^S^' the  short  space  of  20  years  all 
L  have  been  'ogen^^^^^^^n 'aLtnatdlhtpe'reussion  Jtom  has 

stated  to  be  remarkable  for  accuracy  «"^^!'l"»'^'y  ereSn  caps  coated  with  varnish 

:Krd°i7rrJin^i.^'rel^  *'"''  ^^  »' 

'^X^%}^^ClJr^nr^^o..e,  a  - '-trrp^aTtCp-Zse-tr 
from  penetrating  between  the  percussion  caps  and  the  nipple,  ana  x.u      f 

ntRTimS^'ART^^^^^^^  Fr.;  Wohlriechende-kunst,  Germ.);  consiste 

tilled  spirits,  pastes,  pastilles  and  essences. 


PERFUMERY,  ART  OF. 


369 


Fats  ought  to  be  pounded  in  a  marble  mortar,  without  addition  of  water,  till  all  the 
membranes  be  completely  torn ;  then  subjected  to  the  heat  of  a  water -bath  in  a  propCT 
vcesel.  The  fat  soon  melts,  and  the  albumen  of  the  blood  coagulating,  carries  with  it 
all  the  foreign  substances ;  the  liquid  matter  should  be  skimmed,  and  passed  through  a 
canvass  filter. 

0/  pommades  by  infasion. — Rose,  orange-flower,  and  cassia.  Take  334  pounds  of 
hog's  lard,  and  166  of  beef  suet.  These  500  pounds  are  put  into  a  pan  called  bugadier ; 
and  when  melted,  150  pounds  of  rose-leaves  nicely  plucked  are  added,  taking  care  to 
stir  the  mixture  every  hour.  The  infusion  thus  prepared  is  to  remain  at  rest  for  24 
hours ;  at  the  end  of  this  time,  the  pommade  is  again  melted,  and  well  stirred  to  prevent 
its  adherence  to  the  bottom  of  the  melting-pan.  The  mass  is  now  to  be  poured  out  into 
canvass,  and  made  into  rectangular  bricks  or  loaves,  which  are  subjected  to  a  press,  in 
order  to  separate  the  solid  matter  from  the  soft  pommade.  These  brick-shaped  pieces 
being  put  into  an  iron-bound  barrel  perforated  all  over  its  staves,  the  pommade  is  to  be 
allowed  to  exude  on  all  sides,  and  flow  down  into  a  copper  vessel  placed  under  the  trough 
of  the  pxess.  This  manipulation  should  be  repeated  with  the  same  fat  ten  or  twelve 
times ;  or  in  other  words,  3000  pounds  of  fresh  rose-leaves  should  be  employed  to  make 
a  good  pommade. 

The  pommade  of  orange-flowers  is  made  in  the  same  manner,  as  also  the  pommade  of 
cass:.a. 

0/  pommades  vnihoat  infusion. — Jasmine,  tuberose,  jonquil,  narcissus,  and  violet. 

A  square  frame,  called  tiame,  is  made  of  four  pieces  of  wood,  well  joined  together,  2 
or  3  inches  deep,  into  which  a  pane  of  glass  is  laid,  resting  upon  inside  ledges  near  the 
bottom.  Upon  the  surface  of  the  pane  the  simple  pommade  of  hog's  lard  and  suet  is  spread 
with  a  pallet  knife ;  and  into  this  pommade  the  sweet-scented  flowers  are  stuck  fresh 
in  diHcrcTit  points  each  successive  day,  during  two  or  three  months,  till  the  pommade 
has  acquired  the  desired  richness  of  perfume.  The  above-described  frames  are  piled 
closely  over  each  other.      Some  establishments  at  Grasse  possess  from  3000  to  4000  of 

0/  oils. — Rose,  orange-flower,  and  cassia  oils,  are  made  by  infusion,  like  the  pom- 
mades of  the  same  perfumes ;  taking  care  to  select  oils  perfectly  fresh.  As  to  those  of 
jasmine,  tuberose,  jonquil,  violet,  and  generally  all  delicate  flowers,  they  are  made  in  the 
following  manner.  Upon  an  iron  frame,  a  piece  of  cotton  cloth  is  stretched,  imbued 
with  olive  oil  of  the  first  quality,  and  covered  completely  with  a  thin  bed  of  flowers. 
Another  frame  is  similarly  treated,  and  in  this  way  a  pile  is  made.  The  flowers 
must  be  renewed  till  the  oil  is  saturated  with  their  odor.  The  pieces  of  cotton  cloth 
are  then  carefully  pressed  to  extrude  the  oil.  This  last  operation  requires  commonly  7 
or  8  days. 

Of  distillation. — ^The  essential  oils  or  essences,  of  which  the  great  manufacture  is  in 
the  south  of  France,  are  of  rose,  neroli,  lavender,  lemon  thyme,  common  thyme,  and  rose- 
mary.    For  the  mode  of  distilling  the  essential  oils,  see  Oils,  essential. 

The  essence  of  roses  being  obtained  in  a  peculiar  manner,  I  shall  describe  it  here 
Put  into  the  body  of  a  still  40  pounds  of  roses,  and  60  quarts  of  water ;  distil  oflf  one 
half  of  the  water.  When  a  considerable  quantity  of  such  water  of  the  first  distillation 
is  obtained,  it  must  be  used  as  water  upon  fresh  rose-leaves ;  a  process  of  repetition  to 
be  carried  to  the  fifth  time.  In  the  distillation  of  o*Tinge-flower,  to  obtain  the  essence  of 
neroli,  the  same  process  is  to  be  followed ;  but  if  orange-flower  water  merely  be  w^anted, 
then  it  is  obtained  at  one  distillation,  by  reserving  the  first  fifth  part  of  water  that  comes 
over.  What  is  called  the  essence  of  petit-grain,  is  obtained  by  distilling  the  leaves  of  the 
orange  shrub.  The  essences  of  lavender,  thyme,  &c.,  present  nothing  peculiar  in  theit 
mode  of  extraction. 

OF  SCENTED   SPIRITS, 

From  oil  of  rose,  orange,  jasmine,  tuberose,  cassia,  violet,  and  other  flowers. 

Into  each  of  three  digesters,  immersed  in  water-baths,  put  25  lbs.  of  any  one  of  these 
oils,  and  pour  into  the  first  digester  25  quarts  of  spirit  of  wine ;  agitate  every  quarter  of 
an  hour  during  three  days  and  at  the  end  of  this  period,  draw  oflf  the  perfumed  spirit,  and 


Esprit  de  Suave. 
7  Eng.  qrts.  of  spirit  of  jasmine,3d  operation. 

7  —  cassia,        — 

8  —  wine. 

2  —  tuberose,    — 
IJ  ounce  essence  of  cloves. 

I  ounce  fine  neroli. 

1 J  ounce  essence  of  bergamot. 

8  ounces  essence  of  musk,  2d  infusion. 

3  quarts  rose  water. 


Spint  of  Cytfierea^ 
1  quart  spirit  of  violets. 


1 
1 
1 
1 
1 
2 


jasmine,  2d  operation. 

tuberose, 

clove  gillyflower. 

roses,  2d  operation. 

Portugal. 

orange-flower  water 


'V 


[11 

in 


870 


PERFUMERY,  ART  OF. 


pour  it  into  the  second  digester ;  then  transfer  it  after  3  days  into  the  third  digester, 
treating  the  mLxture  in  the  same  way ;  and  the  spirit  thus  obtained  will  be  perfect.  The 
digesters  must  be  carefully  covered  during  the  progress  of  these  operations.  On  pursuing 
the  same  process  with  the  same  oil  and  fresh  alcohol,  essences  of  inferior  qualities  may 
be  obtained,  called  Nos.  2,  3,  and  4. 

Some  perfumers  state  that  it  is  better  to  use  highly  scented  iommades  than  oilflj  out 
there  is  probably  little  difference  in  this  respect. 

Spirit  of  flowers  of  Italy. 


2  quarts  spirit  of  jasmine,  2d  operation. 
2  —  roses, 

2  —  oranges,  3d 

The  above  spirits  mark  usually  28  alcometric  degrees  of  Gay  Lussac. 


2  quarts  spirit  of  cassia,  2d  operation. 
]|  —  orange  flower  water. 


See  Alcohol. 


POMMADES. 

No  less  than  20  scented  pommades  are  distinguished  by  the  perfumers  of  Paris.  The 
essences  commonly  employed  in  the  manufacture  of  pommades,  are  those  of  bergamot, 
lemons,  cedrat,  Hmette  (sweet  lemon),  Portugal,  rosemary,  thyme,  lemon  thyme,  lavender, 
marjoram,  and  cinnamon. 

The  following  may  serve  as  an  example : — 

Pammade  ti  la  vanille,  commonly  called  Roman. 

12  pounds  of  pommade  a  la  rose. 
3       —  oil  a  la  rose. 

1      —         vanilla,  first  quality,  pulverized. 
6  ounces       bergamot. 
The  pommade  being  jnelted  at  the  heat  of  a  water-bath,  the  vanilla  is  to  be  introduced 
with  continual  stirring  for  an  hour.    The  mixture  is  left  to  settle  during  two  hours. 
The  pommade  is  then  to  be  drawn  off,  and  will  be  found  to  have  a  fine  yellow  color,  in* 
stead  of  the  brown  shade  which  it  commonly  has. 

In  making  odoriferous  extracts  and  waters,  the  spirits  of  the  flowers  prepared  by 
macerating  the  flowers  in  alcohol  should  be  preferred  to  their  distillation,  as  forming  the 
foundation  of  good  perfumery.  The  specific  gravity  of  these  spirits  should  be  always 
under  0-88. 


Extract  of  Nosegay  (bouquet). 
2  quarts  spirit  of  jasmine,  1st  operation. 

—  extract  of  violets. 

—  spirit  of  cassia,  1st  — 

—  roses,         -        1st         — 

—  orange,      -         1st  — 

—  Extract  of  clove  gillyflower. 

4  drms.  of  flowers  of  benzoin  (benzoic  acid). 
8  ounces  of  essence  of  amber,  1st  infusion. 


Extract  of  peach  hlossoms. 
6  quarts  of  spirits  of  wine. 
6  pounds  of  bitter  almonds. 
2  quarts  of  spirits  of  orange  flower, 

operation. 
4  drachms  of  essence  of  bitter  almonds. 
4  drachms  of  balsam  of  Peru. 
4  ounces  of  essence  of  lemons. 


2d 


Eau  de  Cologne. 

Two  processes  have  been  adopted  for  the  preparation  of  this  perfume,  distillation  and 
infusion;  the  first  of  which,  though  generally  abandoned,  is,  however,  the  preferable  one. 
The  only  essences  which  should  be  employed,  and  which  have  given  such  celebrity  to 
this  water,  are  the  following;  bergamot,  lemon,  rosemary,  Portugal,  neroli.  The  whole 
of  them  ought  to  be  of  the  best  quality,  but  their  proportions  may  be  varied  according  to 
the  taste  of  the  consumers. 

Thirty  different  odors  are  enumerated  by  perfumers ;  the  three  following  recipes  will 
form  a  sufficient  specimen  of  their  combinations. 


Honey-water. 
6  quarts  of  spirit  of  roses,  3d  operation. 
3     do  jasmine. 

3     do.  spirits  of  wine. 

3  ounces  essence  of  Portugal. 

4  drachms  flowers  of  benzoin. 

12  ounces  of  essence  of  vanilla,  3d  infusion. 
12    do.  musk,  do. 

3  quarts  good  orange- flower  water. 


Eau  de  mille  fleurs. 
18  quarts  of  spirits  of  wine. 
4  ounces  balsam  of  Peru. 
8    do.     essence  of  bergamot. 
4    do.  cloves. 

1     do.    ordinary  neroli. 
1     do.  thyme. 

8    do.  musk,  3d  infusion. 

4  quarts  orange  flower  water. 


PERFUMERY,  ART  OF. 
Eau  de  mousseline^ 


371 


2  ounces  essence  of  vanilla,  3d  infusioi. 
2    do.  musk,  do. 

4  drachms  of  sanders  wood. 
1  quart  of  orange-flower  water. 


2  qnarts  spint  of  roses,  3d  infusion. 
Z   do.  jasmine,  4th  do. 

1  do.  clove  gillyflower. 

2  do.  orange  flower,  4th  do 

jUmond  pastes. 

These  are,  gray,  sweet  white,  and  bitter  white. 

The  first  is  made  either  with  the  kernels  of  apricots,  or  with  bitter  almonds.  They 
are  winnowed,  ground,  and  formed  into  loaves  of  5  or  6  pounds  weight,  which  are  put 
into  the  press  in  order  to  extract  their  oil ;  300  pounds  of  almonds  affording  about  130  ot 
oil.  The  pressure  is  increased  upon  them  every  two  hours  during  three  days ;  at  the  end 
of  which  time  the  loaves  or  cakes  are  taken  out  of  the  press  to  be  dried,  ground,  and 
sifted. 

',  The  second  paste  is  obtained  by  boiling  the  almonds  in  water  till  their  skins  are  com- 
pletely loosened ;  they  are  next  put  into  a  basket,  washed  and  blanched ;  then  dried,  and 
pressed  as  above. 

The  third  paste  is  prepared  like  the  second,  only  using  bitter  almonds. 

Liquid  almond  pastes,  such  as  those  of  the  rose,  orange,  vanilla,  and  nosegay.  The 
honey  paste  is  most  admired.     It  is  prepared  as  follows ; — 

6  pounds  of  honey.  I  12  pounds  oil  of  bitter  almonds. 

6    do.  white  bitter  paste.       j  26  yolks  of  eggs. 

The  honey  should  be  heated  apart  and  strained;  6  pounds  of  almond  paste  must  then 
be  kneaded  with  it,  adding  towards  the  conclusion,  alternately,  the  quanv'Xy  of  yolks  of 
eggs  and  almond  oil  indicated. 

Pastilles  d  la  rose,  orange  flower,  and  vanilla. 

Pastilles  of  orange  flx)wer, 
12  ounces  of  gum  galbanum. 
12    do.  olibanum,  in  tears. 

12    do.  storax,  do. 

8    do.  nitre. 

1  pound  of  pure  orange  powder. 

3    do.     14  ounces  charcoal  powder. 

1  ounce  superfine  neroli. 

Pastilles  d  la  vanille. 


Pastilles  h  la  rose. 

12  ounces 

of  gum. 

12    do. 

olibanum,  in  tears. 

12    do. 

storax,            do. 

8    do. 

nitre. 

16    do. 

powder  of  pale  roses. 

3  pounds  14    do. 

charcoal  powder. 

1    do. 

essence  of  roses. 

16  ounces  powder  of  vanilla. 

3  pounds  14  ounces  charcoal  powder. 

4  drms.  essence  of  cloves. 

8  ounces  do.  vanilla,  1st  infusion. 


12  ounces  of  gum  galbanum. 
12    do.  olibanum,  in  tears. 

12    do.         storax  do. 

8    do.  nitre. 

8    do.  cloves. 

The  above  mixture  in  each  case  is  to  be  thickened  with  2  ounces  of  gum  tragacantk 
dissolved  in  2  pints  of  rose  water.  It  is  needless  to  say  that  the  ingredients  of  the  mix- 
ture should  be  impalpable  powders. 

Scented  cassolettes. 


8  pounds  of  black  amber  (ambergris). 
4    do.  rose  powder. 

2  ounces  of  benzoin. 


1  ounce  essence  of  roses. 
1     do.  gum  tragacanth. 
A  few  drops  of  the  oil  of  sanders  wood. 
These  ingredients  are  pulverized,. and  made  into  a  cohesive  paste  with  the  gum. 


ESSENCES   BY  INFUSION. 

Essence  of  musk. 

5  ounces  of  musk  from  the  bladder,  cut  small. 

1    do.  civet. 

4  quarts  of  spirit  of  ambrette  (purple  sweet  sultan). 

The  whole  are  put  into  a  matrass,  and  exposed  to  the  sun  for  two  months  dnring 
the  hottest  season  of  the  year.  In  winter,  the  heat  of  a  water  bath  mnst  be  r» 
sorted  to. 


I  i' 


372 


PERFUMERY. 


PERSONAL  CLOTHING. 


373 


i 


Essence  of  vanUla. 

8  pounds  of  vanilla  in  branches,  lat  quality,  cut  small. 
4  quarts  spirit  of  ambrette. 
2  arachms  of  cloves. 
■J      do       musk  from  the  bladder. 
Tte  same  process  must  be  followed  as  for  the  essence  of  musk. 


Essence  of  ambergris. 


4  ounces  of  ambergris, 
2  ounces  of  bladder  musk. 


8  quarts  of  spirit  of  ambrette. 
Treat  aa  above. 


/Spirit  of  ambrette  (purple  sweet  sultan). 

25  pounds  of  ambrette  are  to  be  distilled  with  25  quarts  of  spirits  of  wine,  adding  12 
quarts  of  water,  so  as  to  be  able  to  draw  off  the  25  quarts. 

Artificial  Essences  of  Fruits  in  the  Exhibition.  The  artificial  production  of  aro- 
matic oils,  for  industrial  objects,  can  only  be  traced  back  a  few  years.  Young,  however, 
as  this  manufacture  is,  it  appears,  nevertheless,  to  have  been  in  the  hands  of  several 
distillers,  by  whom  a  very  considerable  amount  has  been  produced.  Upon  this  point 
the  jury  became  fully  convinced  by  their  investigations  in  this  department ;  both  in  the 
English  and  in  the  French  divisions  of  the  Exhibition  a  large  selection  of  these  chemical 
perfumeries  were  to  be  found,  the  comparison  of  which  at  the  same  time  with  other 
aromatic  preparations  was  satisfactorily  illustrated.  Most  of  these  oils  are  poisonous 
in  small  quantities,  so  that  in  very  few  instances  can  their  action  be  asserted  without 

fresh  investigations.  •      «  -j 

The  commonest  of  these  preparations  was  the  pear-oil  (Birnol),  a  favourite  fluid, 
which,  by  examination,  is  proved  to  be  an  alcoholic  solution  of  acetate  of  the  oxide  of 
amyle.  As  the  author  had  not  sufficient  of  this  satisfactorily  to  determine  its  com- 
position by  its  combustion,  he  mixed  it  with  potash,  by  which  means  fusel  oil  was  im- 
mediately liberated,  and  the  acetic  acid  was  separated  in  the  form  of  salt  of  silver,  of 
which  0-3089  grammes  gave  0-1994  grammes  silver ;  the  percentage  of  silver  in  the  acetate 
being  theoretically  64-68,  by  experiment  6455.  The  acetate  of  oxide  of  amvle  made  ac- 
cording to  the  usual  process  (1  part  sulphuric  acid,  1  part  fusel  oil,  and  2  parts  of 
acetate  of  potash^  presents  a  strong  fruity  odour,  and  by  the  addition  of  about  6  parts 
of  alcohol,  yields  the  flavour  of  jargonelle  pear.  Upon  closer  inquiry  of  the  manufacturers 
of  this  substance  the  author  found  that  it  was  produced  in  very  considerable  quantities 
(by  some  between  15  and  20  lbs,  weekly).  In  England  it  is  extensively  employed  in 
flavouring  *  pear-drops,'  which  have  almost  superseded  the  common  •  barley-sugar  drops.' 
Next  to  the  "  pear"  oil,  figures  Apple  oil,  which  experiment  has  shown  to  be  nothing 
more  than  a  valerianate  of  oxide  of  amyle,  which  yields  an  insupportable  odour  of  rotten 
apples,  pervading  the  laboratory  where  valerianic  acid  is  produced.  If  the  crude  pro- 
duct of  distillation  be  treated  with  a  solution  of  potash,  the  valerianic  acid  is  removed 
and  the  ether  is  retained ;  the  addition  to  this  of  5  or  6  times  its  volume  of  alcohol  gives 
oflf  an  agreeable  odour  of  aj)ples. 

The  essence,  however,  which  was  observed  to  be  in  the  greatest  abundance  was  the 
"  Pine  Apple  oil"  which  is  simply  a  butyrate  of  oxyde  of  ethyle.  This  composition,  like 
the  two  preceding,  yields  its  flavour  on  the  addition  of  alcohol.  The  butyric  ether, 
which  in  Germany  la  added  to  inferior  sorts  of  rum,  for  the  purpose  of  imparting  a 
flavour  to  a  peculiar  kind  of  drink  (pine  apple  ale),  is  seldom  prepared  for  this  pur- 
pose from  pure  butyric  acid,  but  from  the  saponified  acid,  and  the  distillation  of  the 
soap  with  concentrated  sulphuric  acid  and  alcohol  (vide  Annalen  der  Chemie  und 
Fharmacie,  xlix.  359.)  The  fluid  thus  obtained  contains  other  kinds  of  ether  besides 
butyric  ether,  but  may,  without  these,  be  employed  for  flavouring.  The  analysis  of  this 
ether  by  means  of  potash  and  a  salt  of  silver,  gave  0*4404  gr.  of  salt  of  silver ;  0-2437 
silver ;  the  percentage  of  silver  in  its  butyrate  being,  theoretically,  55-38,  experimen- 
tally, 55-33. 

The  so-called  Cognac  oil  and  Grape  oil  were  contributed  to  both  the  English  and 
French  departments.  They  are  most  frequently  employed  for  giving  the  cognac  flavour 
to  brandies.  The  grape  oil  consists  of  a  compound  of  amyle  dissolved  in  alcohol,  then 
set  free  by  the  addition  of  concentrated  sulphuric  acid;  the  oil  of  sulphate  of  amyle  is 
then  freed  from  alcohol  by  washing  with  water.  Analysed  by  means  of  a  salt  of 
barium  1*2690  gr.  amyl-sulphate  of  baryta  gave  0-5815  gr.  of  sulphate  of  baryta, 
equal  to  45*82  per  cent,  of  sulphate  of  baryta.  According  to  Cahours,  and  again  more 
lately,  according  to  Kekule,  the  analysis  of  amyl-sulphate  of  baryta  with  2  eq.  of  water, 
contains  49*96  per  cent,  of  sulphate  of  baryta.  It  is  certainly  remarkable,  as  has  been 
observed,  that  we  have  here  a  body,  which  is  most  carefully  excluded  from  brandy, 


en  account  of  its  intolerable  odour,  employed  again  under  another  form  to  give  it 
flavour. 

The  next  object  of  attention  is  the  artificial  oil  of  bitter  almonds.  When  Mitscherlich, 
in  1834,  discovered  nitro-benzule,  he  did  not  foresee  the  great  amount  in  which  this 
body  would  be  found  in  an  Industrial  Exhibition.  It  is  true  he  had  observed  the  remark- 
able similarity  of  its  odour  to  that  of  oil  of  bitter  almonds,  but  then  the  only  source 
whence  the  nitro-benzule  could  be  obtained,  viz.,  from  the  oil  of  compressed  gases,  and 
the  distillation  of  benzoic  acid,  were  too  costly  to  admit  of  the  idea  of  its  employment 
as  a  substitute  for  oil  of  bitter  almonds.  It  remained  for  the  author,  in  1845,  to  detect 
the  presence  of  benzule  in  the  transformation  of  coal  tar ;  and  in  1849,  Mansfield 
(Chmncal  Society's  Quarterly  Journal,  i.,  244.;  Annalen,  Ixix  162.)  showed  that  it 
could  be  obtained  with  facility  in  considerable  quantities  from  coal  tar.  The  Great 
Exhibition  has  shown  that  this  statement  has  not  been  lost  sight  of  In  the  French 
department  of  perfumery,  it  was  met  with  under  the  designation  of  artificial  oil  of  bit- 
ter almonds,  and  under  the  fantastic  name  of  essence  of  rairbane,  varieties  of  the  oil 
"which,  on  examination,  were  found  to  be  more  or  less  pure  nitro-benzule.  In  London 
it  is  used  in  large  quantities.  Messrs.  Mansfield's  simple  apparatus  for  its  preparation 
is  thus  described : — A  large  glass  worm  is  used,  the  upper  end  of  which  is  bifurcated, 
and  forms  two  tubes  of  a  funnel  shape  ;  into  one  of  these  funnels  concentrated  nitric 
acid  is  poured,  in  the  other  the  benzule  ia  placed  (and  for  thia  purpoae  it  is  not  required 
to  be  absolutely  pure).  The  two  bodies,  therefore,  meet  at  the  point  of  junction  of 
these  two  tubes,  the  compound  is  cooled  by  its  course  through  the  windings  of  the  worm, 
and  requires  only  to  be  washed  with  water  or  diluted  solution  of  carbonate  of  soda, 
and  it  is  then  fit  for  use.  Although  nitro-benzule  has  an  odour  so  closely  resembling 
oil  of  bitter  almonds,  a  difference  may  be  detected  by  an  experienced  nose.  It  is,  how 
ever,  very  generally  employed  in  scenting  soaps,  in  confectionery,  and  for  culinary  pur- 
poses. For  the  last  named  purpose  it  has  the  advantage  of  not  containing  hydrocyanic 
acid. 

Besides  the  preceding,  many  other  substances  of  analogous  nature  were  exhibited, 
but  they  were  of  too  complicated  characters  to  be  satisfactorily  examined  in  the  small 
<5^uantitie8  to  be  met  with.  In  many  of  these  essences  there  was,  however,  a  great 
similarity  of  aroma. 

PERFUMERY,  INDIAN.  The  natives  place  on  the  ground  a  layer  of  the  scented 
flowera,  about  4  inches  thick  and  2  feet  square ;  cover  them  over  with  a  layer  2  inches 
thick  of  Tel  or  Sesamum  seed  wetted ;  then  lay  on  another  4  inch  bed  of  flowera,  and 
cover  this  pile  with  a  sheet,  which  is  pressed  down  by  weights  round  the  edges.  After 
remaining  in  this  state  for  18  hours,  the  flowei*s  are  removed  and  replaced  by  a  similar 
fresh  layer,  and  treated  as  before ;  a  process  which  is  repeated  a  third  time  if  a  very 
rich  perfumed  oil  be  required.  The  sesamum  seeds  thus  imbued  with  the  essential  oU 
of  the  plants  whether  jasmine,  Bela,  or  Chumbul,  are  placed  in  their  swollen  state  in  a 
mill,  and  subjected  to  strong  pressure,  whereby  they  give  out  their  bland  oil  strongly 
impregnated  with  the  aroma  of  the  particular  flower  employed.  The  oil  ia  kept  in 
prepared  skins  called  dubbers,  and  is  largely  used  by  the  Indian  women.  The  attar  of 
roses  is  obtained  by  distillation  at  a  colder  period  of  the  year. 

PERRY,  is  the  fermented  juice  of  pears,  prepared  in  exactly  the  same  way  as  Cydeb. 

PERSIAN  BERRIES.     See  Berries,  Persian. 

PERSONAL  CLOTHING.     The  title  of  the  class  will  suggest  the  multifarious  ob 
jects  which  fall  naturally  within  its  comprehensive  limits.     The  sub-classes  are  as  fol- 
lows : — A  hat^  caps,  and  bonnets  of  various  materials ;  B.  hosiery,  of  cotton,  woollen, 
and  silk ;  C.  gloves  of  leather  and  other  materials ;  D.  boots,  shoes,  and  lasts ;  E.  under- 
clothing; F.  upper-clothing. 

The  manufactories  of  hosiery,  straw  plait,  and  boots  and  ahoes,  have  a  local  establish- 
ment in  this  country,  which  is  deserving  of  attention ;  that  of  hosiery  is  principally 
confined  to  Derby,  Nottingham,  and  Leicester.  Cotton  hosiery  is  chiefly  made  in  Not- 
tingham, as  also  is  the  silk  hosiery;  the  latter  being  likewise  largely  conducted  in 
Derby.  Woollen  hosiery  is  most  extensively  produced  in  Leicestershire.  The  statistics 
of  these  tradea  have  been  carefully  prepared  and  are  very  intereating.  The  annual 
value  of  cotton  hosiery  is  taken  at  880,000/.,  that  of  worsted,  <fec.,  is  870,000/.,  and  of 
silk,  241,000/.  In  the  manufacture  of  these  goods  it  is  estimated  that  4,584,000  lbs.  of 
raw  cotton  wool  are  used, — 6,318,000  lbs.  of  English  wool,  and  140,000  lbs.  of  silk. 
The  total  number  of  persons  deriving  support  from  the  manufacture  is  about  73,000, 
and  about  1,050,000/.  of  floating  capital  is  considered  to  be  employed  in  the  various 
branches  of  the  trade. 

The  manufacture  of  straw  plait  is  carried  on  chieflj'  at  St.  Alban'a,  Dunstable,  Tring; 
and  a  few  other  places.  That  of  boots  and  shoes  is  conducted  on  a  very  large  scale  at 
Northampton,  from  which  place  vast  quantities  of  these  articles  are  sent  out  ready  for 
Wear.     Worcester,  Dundee,  and  Woodstock  are  celebrated  for  their  glove  manufactures. 


i 


;>i   ' 


li. 


374 


PHANTASMAGORIA. 


Gloves  are  of  great  antiquity  in  this  island,  as  the  word  is  evidently  derived  from 
the  Anglo-Saxon  "  glof "  They  are  not  mentioned  in  Scripture,  but  were  in  use  among 
the  Romans  in  the  time  of  Pliny  the  Younger.  Xenophon  states  that  their  use  among 
the  Persians  was  considered  a  proof  of  their  luxurious  habits.  Gloves  have  had  many 
symbolical  meanings.  The  gauntlet  or  glove  thrown  down  was  a  mode  of  challenge, 
and  still  is  practised  as  one  of  the  forms  of  royal  coronation.  Queen  Elizabeth,  it  is 
well  known,  was  verj'  fond  of  gloves,  of  which  numerous  presents  were  made  to  her. 
White  gloves  are  also  presented  to  the  judges  on  occasion  of  a  maiden  assize,  the 
exact  significance  or  origin  of  which  practice  has  never  b«6n  satisfactorily  explained. 
Leather  gloves  are  now  made  at  Worcester,  Yeovil,  Woodstock,  and  London,  and  were 
formerly  made  at  Jjeominster  and  Ludlow,  but  the  trade  in  the  latter  places  is  quite 
decayed. 

Plait  straw  is  the  straw  of  the  wheat  plant,  selected  especially  from  crops  grown  on 
dry  chalky  lands,  such  as  those  about  Dunstabla  The  middle  part  of  the  straw  above 
the  last  joint  is  selected ;  it  is  cut  into  lengths  of  eight  or  ten  inches,  and  these  are  then 
split  The  Leghorn  or  Tuscan  is  the  straw  of  a  variety  of  bearded  wheat,  grown  expressly 
on  poor  sandy  soils,  pulled  when  green,  and  then  bleached.  Other  kinds  of  the  grass 
tribe  besides  wheat  ftirnish  straws  available  for  plait-work. 

PETROLEUM.     See  Naphtha. 

PE-TUNT-SE,  is  the  Chinese  name  of  the  fusible  earthy  matter  of  their  porcelain. 
It  la  analc^ous  to  our  Cornish  stone. 

PEWTER,  PEWTERER.  (Potier  d'iiain,  Fr.)  Pewter  is,  generally  speaking, 
an  alloy  of  tin  and  lead,  sometimes  with  a  little  antimony  or  copper,  combined  in 
several  different  proportions,  according  to  the  purposes  which  the  metal  is  to  serve. 
The  English  tradesmen  distinguish  three  sorts,  which  they  call  plate,  trifle,  and  ley 
pewter ;  the  first  and  hardest  being  used  for  plates  and  dishes  ;  the  second  for  beer-pots ; 
and  the  third  for  larger  wine  measures.  The  plate  pewter  has  a  bright  silvery  lustre 
when  polished ;  the  best  is  composed  of  100  parts  of  tin,  8  parts  of  antimony,  2  parts  of 
bismuth,  and  2  of  copper.  The  trifle  is  said  by  some  to  consist  of  83  of  tin,  and  17  of 
antimony  ;  but  it  generally  contains  a  good  deal  of  lead.  The  ley  pewter  is  composed 
of  4  of  tin,  and  1  of  lead.  As  the  tendency  of  the  covetous  pewterer  is  always  to  put  in 
as  much  of  the  cheap  metal  as  is  compatible  with  the  appearance  of  his  metal  i'*  the 
market,  and  as  an  excess  of  lead  may  cause  it  to  act  poisononsly  upon  all  vinegars  and 
many  wines,  the  French  government  long  ago  appointed  Fourcroy,  Vauciuelin,  and 
other  chemists,  to  ascertain  by  experiment  the  proper  proportions  of  a  safe  pewter 
alloy.  These  commissioners  found  that  18  parts  of  lead  might,  without  danger  of 
affecting  wines,  &c.,  be  alloyed  with  82  parts  of  tin ;  and  the  French  government  ia 
consequence  passed  a  law  requiring  pewterers  to  use  83|  of  tin  in  100  parts,  with  a 
tolerance  of  error  amounting  to  1|  per  cent.  This  ordonnance,  allowing  not  more  than 
J 8  per  cent,  of  lead  at  a  maximum,  has  been  extended  to  all  vessels  destined  to  contain 
alimentary  substances.  A  table  of  specific  gravities  was  also  published,  on  purpose  to 
test  the  quality  of  the  alloy ;  the  density  of  which,  at  the  legal  standard,  is  7-764.  Any 
excess  of  lead  is  immediately  indicated  by  an  increase  in  the  specific  gravity  above  that 
number. 

The  pewterer  fashions  almost  all  his  articles  by  casting  them  in  moulds  of  brass  or 
bronze,  which  are  made  both  inside  and  outside  in  various  pieces,  nicely  fitted  together, 
and  locked  in  their  positions  by  ears  and  catches  or  pins  of  various  kinds.  The  moulds 
must  be  moderately  heated  before  the  pewter  is  poured  into  them,  and  their  surfaces 
should  be  brushed  evenly  over  with  pounce  powder  (sandarach)  beaten  up  with  while  of 
egg.  Sometimes  a  film  of  oil  is  preferred.  The  pieces,  af\er  being  cast,  are  turned  and 
polished ;  and  if  any  part  needs  soldering,  it  must  be  done  with  a  fusible  alloy  of  tin, 
bismuth,  and  lead. 

Britannia  metal,  the  kind  of  pewter  of  which  English  tea-pots  are  made,  is  said  to  be 
an  alloy  of  equal  parts  of  brass,  tin,  antimony,  and  bismuth  ;  but  the  proportions  diflei 
in  difl'erent  workshops,  and  much  more  tin  is  commonly  introduced.  Queen's  metal  is 
said  to  consist  of  9  parts  of  tin,  1  of  antimony,  1  of  bismuth,  and  1  of  lead ;  it  serves  also 
for  teapots  and  other  domestic  utensils. 

A  much  safer  and  better  alloy  for  these  purposes  may  be  compounded  by  adding  to  100 
parts  of  the  French  pewter,  5  parts  of  antimony,  and  5  of  brass  to  harden  it.  The 
English  ley  pewter  contains  often  much  more  than  20  per  cent,  of  lead.  Under  TiH, 
wifl  be  found  the  description  of  an  easy  method  of  analyzing  its  lead  alloys. 

PHANTASMAGORIA.  The  phantasmagoria  lanterns  are  a  scientific  form  of  magio 
lantern,  differing  from  it  in  no  essential  principle.  The  images  they  produce  are 
variously  exhibited,  either  on  opaque  or  transparent  screens.  Tlie  light  is  an  improved 
kind  of  solar  lamp.  The  manner  in  which  the  beautiful  melting  pictui-es  called  dissolving 
views  are  produced,  as  respects  the  mechanism  employed,  deserves  to  be  explained.  The 


PHARMACEUTICAL  PRODUCTS. 


375 


arrangement  adopted  in  the  instrument  is  the  following : — ^Two  lanterns  of  the  same 
•ize  and  power,  and  in  all  respects  exactly  agreeing,  are  arranged  together  upon  a  little 
tray  or  platform.  They  are  held  fast  to  this  stand  by  screws,  which  admit  of  a  certain 
degree  of  half-revolving  motion  from  side  to  side,  in  order  to  adjust  the  foci.  This  being 
done  in  such  a  manner  that  the  circle  of  light  of  each  lantern  falls  precisely  upon  the 
same  spot  upon  the  screen,  the  screws  are  tightened  to  the  utmost  extent  so  as  to  remove 
all  possibility  of  further  movement.  The  dissolving  apparatus  consists  of  a  circular  tin 
plate  japanned  in  black,  along  three  parts  of  the  circumference  of  which  a  crescented 
aperture  runs,  the  interval  between  the  horns  of  the  crescent  being  occupied  by  a  circular 
opening,  covered  by  a  screwed  plate,  removable  at  pleasure.  This  plate  is  fixed  to  a 
horizontal  woodeu  axis,  at  the  other  end  of  which  is  a  handle,  by  which  the  plate  can  be 
caused  to  rotate.  The  axis  of  wood  is  supported  by  two  pillars  connected  with  a  flat 
piece  which  is  secured  to  the  tray.  This  apparatus  is  placed  between  the  lanterns  in 
such  a  manner  that  the  circular  plate  is  in  front  of  the  tubes  of  both,  while  the  handle 
projects  behind  the  lanterns  at  the  back.  The  plate  can,  therefore,  be  turned  round  by 
means  of  the  handle  without  difficulty,  from  behind.  A  peg  of  wood  is  fixed  into  the  axifl> 
eo  as  to  prevent  its  effecting  more  than  half  a  revolution.  The  widest  part  of  the  eresceutic 
opening  in  the  plate  is  sufficient  to  admit  all  the  rays  of  the  lantern  before  which  it 
happens  to  be  placed-  On  the  plate  being  slowly  turned  half  round,  by  means  of  the 
handle  behind,  the  opening  narrows  until  it  is  altogether  lost  in  one  of  the  horns  of  the 
crescent.  The  light  of  that  lantern  is  gradually  cut  off  as  the  aperture  diminishes,  until 
it  is  at  length  wholly  shaded  under  the  moveable  cover  occupying  the  interval  between 
the  horns  of  this  crescentic  opening.  In  proportion  as  the  light  is  cut  off  from  one,  it  is 
let  on  from  the  other  tube,  in  consequence  of  the  gradually  increasing  size  of  the  crescent 
revolving  before  it,  until  at  length  the  widest  part  of  this  opening  in  the  plate  is  pre- 
sented before  the  tube  of  the  second  lantern,  the  first  being,  as  we  have  seen,  shaded. 
This  movement  being  reversed,  the  light  is  cut  off  from  the  second  lantern,  and  again 
let  on  from  the  first,  and  so  on  alternately.  Thus  while  the  screen  always  presents 
the  same  circle  of  light,  yet  it  is  derived  first  from  one  lantern,  then  from  the  next. 

When  in  use  a  slider  is  introduced  into  each  lantern.  The  lantern  before  the  mouth 
of  which  the  widest  part  of  the  opening  in  the  plate  is  placed,  exhibits  the  painting  on 
the  screen,  the  light  of  the  other  lantern  being  then  hid  behind  the  cover.  On  turning 
the  handle,  this  picture  gradually  becomes  shaded,  while  the  light  frona  the  second 
lantern  streams  through  the  widening  opening.  The  effect  on  the  screen  is  the  melting 
away  of  the  first  picture,  and  the  brilliant  development  of  the  second,  the  screen  being 
at  no  instant  left  unoccupied  hy  a  picture. 

The  principle  involved  in  this  apparently  complex,  but  in  reality  simple  mechanism, 
is,  merely  the  obscuration  of  one  picture,  and  the  throwing  of  a  second  in  the  same 
place  on  the  screen.  And  it  may  be  accomplished  in  a  great  variety  of  ways.  Thus  by 
aimply  placing  a  flat  piece  of  wood,  somewhat  like  the  letter  Z  on  a  point  in  the  centre, 
so  that  alternately  one  or  the  other  of  the  pieces  at  the  end  should  be  raised  or 
depressed  before  the  lanterns,  a  dissolving  scene  is  produced.  Or,  by  fixing  a  moveable 
upright  shade,  which  can  be  pushed  alternately  before  one  or  the  other  of  the 
lanterns,  the  same  effect  is  produced. 

Individuals  exist  in  this  metropolis  whose  sole  occupation  consists  in  painting 
the  minute  scenes  or  slides  used  for  the  phantasmagoria  lanterns.  The  perfection 
to  which  these  paintings  are  brought  is  surprising.  There  are  two  methods  by  which 
the  sliders  now  emplo^-ed  are  produced.  In  one  of  these,  the  outline  and  detail  are 
entirely  the  work  of  the  artist's  pencil.  For  pictures  representing  landscapes,  or  wherever 
a  spirited  painting  is  required,  this  is  the  exclusive  method  employed.  The  colours  are 
rendered  transparent  by  being  ground  in  Canada  balsam  and  mixed  with  varnish.  The 
other  method  is  a  transfer  process.  The  outlines  of  the  subject  are  engraved  on  copper 
plates,  and  the  impression  is  received  from  these  on  thin  sheets  of  glue,  and  is  then 
transferred  to  a  plate  of  glass,  the  impression  being  burnt  in  the  same  manner  as  ia 
effected  in  earthenware.  Sliders  produced  in  this  way  receive  the  distinctive  name  of 
copper  plate  sliders.  The  subject  is  merely  represented  in  outline,  it  being  left  to  the 
artist  to  fill  up  with  the  necessary  tints,  <fec  The  advantages  of  this  method  for  the 
production  of  paintings  of  a  limited  kind  are  obvious.  Latterly  photography  on  glass 
has  been  employed  to  obtain  pictures  for  the  magic  lantern. 

PHARMACEUTICAL  PRODUCTS.— /foj»«.  These  hops  are  samples  of  the 
varieties  in  most  estimation  for  the  purposes  of  the  brewer.  The  Goldings  take  their  name 
from  that  of  a  grower  who  first  introduced  them;  they  are  considered  to  be  the  finest, 
richest  and  most  valuable  in  the  market,  varying,  however,  according  to  the  soil  in  which 
they  are  grown  and  the  treatment  they  receive ;  Jones's  are  of  shorter  growth  than  the 
others,  and  are  thus  useful  by  enabling  the  grower  to  make  use  of  the  poles  which  would 
be  too  short  for  the  Golding  or  other  varieties.  Colegates  are  hardy  but  backward  at 
harvest,  running  much  to  vine  and  capable  of  growing  in  comparatively  poor  soila. 


!i 


S?6 


PHOSPHORUS. 


PHOSPHORUS. 


377 


•' 


U  I 


These  qualities  are,  however,  of  advantage,  as  the  inferior  soils  may  thus  be  bene- 
ficially occupied  by  them,  and  their  harvest  takes  place  after  the  finer  sorts  are  all  in. 
The  grape  hop  takes  its  name  from  its  habit  of  growing  in  clusters  like  the  grape.  It 
18  hardv,  not  so  particular  as  to  soil  as  the  Goldings,  and  is  generally  very  productive 

Some  conception  of  the  quantity  of  hops  annually  produced  in  Great  Britain,  prin- 
cipally in  Kent,  Sussex,  Worcester,  and  Hereford,  may  be  obtained  from  the  fact 
that  m  1842  the  duty  (2d  per  Ib^  amounted  to  260,978^.:  the  plant  belongs  to 
the  same  natural  family  as  hemp,  Cannalinacece.  Ite  botanical  name  is  Hwnulu* 
lupulus. 

Pharmaceutical  Extracts, — Pharmaceutical  eirtracts  were  for  a  copsiderable  period 
the  most  fallacious  of  all  medical  preparations.  The  high  temperature  to  which  they 
were  subjected  in  the  manufacture  destroyed  the  active  principle  sought  to  be  concen- 
trated. Of  late  they  have  been  prepared  in  some  instances,  by  evaporation  in  the  cold, 
a  current  of  air  being  driven  over  the  surface  of  the  liquid.  They  are  also  safely  ob- 
tainable by  using  an  apparatus  similar  to  that  employed  in  the  sugar  manufacture. 

Kou»so ;  a  new  remedial  agent  for  the  removal  of  tape  worm.  That  it  is  de- 
ttructive  to  that  parasitic  disease  has  been  satisfactorily  shown.  The  plant  has  been 
long  known  in  the  East,  and  actively  employed  in  Abyssinia.  Dr.  Pereira  has  given 
an  elaborate  account  of  this  plant,  which  is  known  by  the  name  of  Brayera  anthel- 
mintica,  from  its  properties  and  the  name  of  its  discoverer,  Dr.  Brayer.  Wittstein 
and  Martin  have  given  chemical  analyses  of  the  plant 

Superphosphate  of  iron  ;  a  new  preparation  of  iron  recently  introduced  by  Dr.  Routh, 
fupposed  to  be  the  same  salt  contained  in  the  blood.  It  is  free  from  all  ferruginous 
taste,  and  so  well  adapted  for  children :  believed  to  be  more  speedy  in  its  action  than 
the  other  salts  of  iron  in  cases  of  nervous  debilit}-,  where  there  is  a  large  quantity  of 
phosphates  voided  by  the  urine,  probably  because  it  supplies  directly  to  the  brain  the 
phosphorus,  on  the  undue  diminution  of  which  the  nervous  derangement  depends. 
Syrup  of  superphosphate  of  iron,  adapted  for  administering  the  remedy  to  children, 
and  probably  the  best  form  for  general  use. 

PHOSPHORIC  ACID,  is  the  acid  formed  by  the  vivid  combustion  of  phosphorua 
In  the  British  portion  of  the  Exhibition,  there  was  one  acid  missing  which  existed 
in  great  abundance  and  perfection  amongst  the  German  chemical  preparations.  We 
allude  to  the  glacial  phosphoric  acid,  of  which  that  displayed  by  the  Royal  Prussian 
chemical  manufactory  at  Schonebeck  can  scarcely  be  too  highly  spoken  of  From  some 
unknown  cause,  this  has  not  attracted  the  attention  which  it  deserves  in  the  arts  and 
manufactures  of  this  country.  For  many  of  the  wants  of  the  dyer,  the  calico  printer, 
the  enameller,  and  even  in  the  purification  of  some  oils  and  fat,  the  glacial  phosphoric 
acid  has  much  to  recommend  it  over  any  of  the  common  acids  at  present  in  use.  Nor 
need  its  price  prove  an  insuperable  obstacle  to  its  introduction  as  a  practical  agent. 
Finely  ground  bone-ash,  digested  with  a  due  proportion  of  oxalic  acid  and  water, 
readily  yields  a  solution  of  phosphoric  acid,  which  requires  only  to  be  evaporated  in  a 
proper  vessel  to  furnish  at  once  this  useful  article.  Unlike  sulphuric  and  other  strong 
acids,  it  is  not  decomposed  by  organic  matter ;  and  might  hence  be  employed  with 
great  advantage  in  the  precipitation  of  carmine  and  other  delicate  vegetable  colours, 
as  well  as  for  more  general  purposes.  Some  experiments  have  also  shown  that  com- 
bined with  alumina  and  a  little  boracic  acid,  it  is  capable  of  producing  a  glaze  for 
earthenware  of  extreme  beauty  and  durabilit}^,  in  addition  to  its  perfectly  innocuous 
character  and  power  of  improving  the  colours  imparted  by  most  metallic  oxides  when 
applied  to  earthenware. 

PHOSPHORUS.  This  interesting  simple  combustible,  being  an  object  of  extensive 
consumption,  and  therefore  of  a  considerable  chemical  manufacture,  I  shall  describe  the 
requisite  manipulations  for  preparing  it  at  some  detail.  Put  1  cwt.  of  finely  ground  bone- 
ash,  such  as  is  used  by  the  assayers,  into  a  stout  tub,  and  let  one  person  work  it  into  a  thin 
pap  with  twice  its  weight  of  water,  and  let  him  continue  to  stir  it  constantly  with  a 
wooden  bar,  while  another  person  pours  into  it,  in  a  uniform  but  very  slender  stream,  78 
pounds  of  concentrated  sulphuric  acid. 

The  heat  thus  excited  in  the  dilution  of  the  acid,  and  in  its  reaction  upon  the  calcareous 
base,  is  favorable  to  the  decomposition  of  the  bone  phosphate.  Should  the  resulting 
sulphate  of  lime  become  lumpy,  it  must  be  reduced  into  a  uniform  paste,  by  the  addition 
of  a  little  water  from  time  to  time.  This  mixture  must  be  made  out  of  doors,  as  under 
an  open  shed,  on  account  of  the  carbonic  acid  and  other  offensive  gases  which  ar« 
extricated.  At  the  end  of  24  hours,  the  pap  may  be  thinned  with  water,  and,  if  con- 
renient,  healed,  with  careful  stirring,  to  complete  the  chemical  change,  in  a  square  pan 
made  of  sheet  lead,  simply  folded  up  at  the  sides.  Whenever  the  paste  has  lost  its  gra« 
nular  character,  it  is  ready  for  transfer  into  a  series  of  tall  casks,  to  be  further  diluted 
and  settled,  whereby  the  clear  superphosphate  of  lime  may  be  run  oS  by  a  syphon  from 


the  deposite  of  gypsum.  More  water  must  then  be  jnixed  with  the  precipitate,  after 
subsidence  of  which,  the  supernatant  liquor  is  again  to  be  drawn  off.  The  skilful  operator 
employs  the  weak  acid  from  one  cask  to  wash  the  deposite  in  another,  and  thereby  saves 
fuel  in  evaporation. 

The  collected  liquors  being  put  into  a  leaden,  or  preferably  a  copper  pan,  of  proper 
dimensions,  are  to  be  concentrated  by  steady  ebullition,  till  the  calcareous  deposite  be- 
comes considerable ;  after  the  whole  has  been  allowed  to  cool,  the  clear  liquor  is  to  be  run 
off,  the  sediment  removed,  and  thrown  on  a  filter.  The  evaporation  of  the  clear  liquor 
is  to  be  urged  till  it  acquires  the  consistence  of  honey.  Being  now  weighed,  it  should 
amount  to  37  pounds.  One  fourth  of  its  weight  of  charcoal  in  fine  powder,  that  is,  about 
9  pounds,  are  then  to  be  incorporated  with  it,  and  the  mixture  is  to  be  evaporated  to 
dryness  in  a  cast-iron  pot.  A  good  deal  of  sulphurous  acid  is  disengaged  along  with 
the  steam  at  first,  from  the  reaction  of  the  sulphuric  acid  upon  the  charcoal,  and  atler- 
wards  some  sulphureted  hydrogen.  When  the  mixture  has  become  perfectly  dry,  as 
shown  by  the  redness  of  the  bottom  of  the  pot,  it  is  to  be  allowed  to  cool,  and  packed 
tight  into  stoneware  jars  fitted  with  close  covers,  till  it  is  to  be  subjected  to  distillation. 
For  this  purpose,  earthen  retorts  of  the  best  quality,  and  free  from  air-holes,  must  be 
taken,  and  evenly  luted  over  their  surface  with  a  compost  of  fire-clay  and  horse-dung. 
When  the  coating  is  dry  and  sound,  the  retort  is  to  be  two  thirds  filled  with  the  powder, 
and  placed  upon  proper  supports  in  the  laboratory  of  an  air-furnace,  having  lis  fire 
placed  not  immediately  beneath  the  retort,  but  to  one  side,  after  the  plan  of  a  reverber- 
atory ;  whereby  the  flame  may  play  uniformly  round  the  retort,  and  the  fuel  may  be 
supplied  as  it  is  wanted,  without  admitting  cold  air  to  endanger  its  cracking.  The  gal- 
lery furnace  of  the  palatinate  (under  Mercury)  will  show  how  several  retorts  may  be 
operated  upon  together,  with  one  fire. 

To  the  beak  of  the  retort  properly  inclined,  the  one  end  of  a  bent  copper  tube  is  to 
be  tightly  luted,  while  the  other  end  is  plunged  not  more  than  one  quarter  of  an  inch 
beneath  the  surface  of  water  contained  in  a  small  copper  or  tin  trough  placed  beneath, 
close  to  the  side  of  the  furnace,  or  in  a  wide-mouthed  bottle.  It  is  of  advantage  to  let 
the  water  be  somewhat  warm,  in  order  to  prevent  the  concretion  of  the  phosphorus 
in  the  copper  tube,  and  the  consequent  obstruction  of  the  passage.  Should  the  beak  of 
the  retort  appear  to  get  filled  with  solid  phosphorus,  a  bent  rod  of  iron  may  be  heated,  and 
passed  up  the  copper  tube,  without  removing  its  end  from  the  water.  The  heat  of 
the  furnace  should  be  most  slowly  raised  at  first,  but  afterwards  equably  maintained  in 
a  state  of  bright  ignition.  After  3  or  4  hours  of  steady  firing,  carbonic  acid  and  sul- 
phurous acid  gases  are  evolved  in  considerable  abundance,  provided  the  materials  had 
not  been  well  dried  in  the  iron  pot;  then  sulphureted  hydrogen  makes  its  appearance, 
and  next  phosphureted  hydrogen,  which  last  should  continue  during  the  whole  of  the 
distillation. 

The  firing  should  be  regulated  by  the  escape  of  this  remarkable  gas,  which  ought  to 
be  at  the  rate  of  about  2  bubbles  per  second.  If  the  discharge  comes  to  be  inter- 
rupted, it  is  to  be  ascribed  either  to  the  temperature  being  too  low,  or  to  the  retort  get- 
ting cracked ;  and  if  upon  raising  the  heat  sufiicicntly  no  bubbles  appear,  it  is  a  proof 
that  the  apparatus  has  become  defective,  and  that  it  is  needless  to  continue  the  operation. 
In  fact,  the  great  nicety  in  distilling  phosphorus  lies  in  the  management  of  the  fire,  which 
must  be  incessantly  watched,  and  fed  by  the  successive  introduction  of  fuel,  consisting 
of  coke  with  a  mixture  of  dry  wood  and  coal. 

We  may  infer  that  the  process  approaches  its  conclusion  by  the  increasing  slowness 
with  which  gas  is  disengaged  under  a  powerful  heat ;  and  when  it  ceases  to  come  over, 
we  may  cease  firing,  taking  care  to  prevent  reflux  of  water  into  the  retort,  from  conden- 
sation of  its  gaseous  contents,  by  admitting  air  into  it  through  a  recurved  glass  tube,  or 
through  the  lute  of  the  copper  adopter. 

The  usual  period  of  the  operation  upon  the  great  scale  is  from  24  to  30  hours.  Its 
theory  is  very  obvious.  The  charcoal  at  an  elevated  temperature  disoxyge-iates  the 
phosphoric  acid  with  the  production  of  carbonic  acid  gas  at  first,  and  afterwards  carbonic 
oxyde  gas,  along  with  sulphureted,  carbureted,  and  phosphureted  hydrogen,  from  the 
reaction  of  the  water  present  in  the  charcoal  upon  the  other  ingredients. 

The  phosphorus  falls  down  in  drops,  like  melted  wax,  and  concretes  at  the  bottom 
of  the  water  in  the  receiver.  It  requires  to  be  purified  by  squeezing  in  a  shamoy  leather 
bag,  while  immersed  under  the  surface  of  warm  water,  contained  in  an  earthen  pan. 
Each  bag  must  be  firmly  tied  into  a  ball  form,  of  the  size  of  the  fist,  and  compressed,  under 
the  water  heated  to  130°,  bv  a  pair  of  fiat  wooden  pincers,  like  those  with  which  oranges 
are  squeezed 

The  purified  phosphorus  is  moulded  for  sale  into  little  cylinders,  bj  melting  it  at  tne 
bottom  of  a  deep  jar  filled  with  water,  then  plunging  the  wider  end  of  a  slightly  tapering 
but  straight  glass  lube  into  the  water,  sucking  this  up  to  the  top  of  the  glass,so  as  to  warm 

Vol.  IL  so 


378 


PHOSPHORUS. 


PHOSPHORUS. 


379 


t  1 


; 


it,  next  immersing  the  end  in  the  liquid  phosphoras,  and  sucking  it  np  to  any  desired 

heisrhta 

The  tube  being  now  shut  at  bottom  by  the  application  of  the  point  of  the  left  index, 
may  be  taken  from  the  mouth  and  transferred  into  a  pan  of  cold  water  to  congeal  the 
phosphorus ;  which  then  will  commonly  fall  out  of  itself,  if  the  tube  be  nicely  tapered, 
or  may  at  any  rale  be  pushed  out  with  a  stiff  wire.  Were  the  glass  lube  not  duly  warm- 
ed before  sucking  up  the  phosphorus,  this  would  be  apt  to  congeal  at  the  sides,  before  the 
middle  be  filled,  and  thus  form  hollow  cylinders,  very  troublesome  and  even  dangerous 
to  the  makers  of  phosphoric  match-bottles.  The  moulded  sticks  of  phosphorus  are  finally 
to  be  cut  with  scissors  under  water  to  the  requisite  lengths,  and  jiut  up  in  vials  of  a  pro- 
per  size ;  which  should  be  filled  up  with  water,  closed  with  ground  stoppers,  and  kept  m 
a  dark  place.  For  carriage  to  a  distance,  each  vial  should  be  wrapped  in  paper,  and  fit- 
ted into  a  tin-plate  case.  ,  u      /v       j 

Phosphorus  has  a  pale  yellow  color,  is  nearly  transparent,  brittle  when  cold,  soft  and 
pliable,  like  wax,  at  the  temperature  of  70°  F.,  cn'slallizing  in  ihombo-dodecahedrons 
out  of  its  combination  with  sulphur,  and  of  specific  gravity  1-77.  It  exhales  white 
fumes  in  the  air,  which  have  a  garlic  smell,  appear  luminous  in  the  dark,  and  spon- 
taneously condense  into  liquid  phosphorous  acid.  Phosphorus  melts  in  close  vessels,  at 
95°  F.,  into  an  oily-looking  colorless  fluid,  begins  to  evaporate  at  217-5°,  boils  at 
554°  and  if  poured  in  the  liquid  state  into  ice-cold  water,  it  becomes  black,  but  resumes 
its  former  color  when  again  melted  and  slowly  cooled.  It  has  an  acrid  disagreeable 
taste  and  acts  deleleriously  in  the  stomach,  though  it  has  been  administered  as  a  me- 
dicine by  some  of  the  poison-doctors  of  the  present  day.  It  takes  fire  in  the  open  air  at  the 
temperature  of  165°,  but  at  a  lower  degree  if  partially  oxydized,  and  bums  with  great  vehe- 
mence and  splendor. 

Inflammable  match-boxes  (hriqneta  phosphcriqnes)  are  usually  prepared  by  putting 
into  a  small  vial  of  glass  or  lead  a  bit  of  phosphorus,  and  oxydizing  it  slightly  by 
stirring  it  round  with  a  redhot  iron  wire.  The  vial  should  be  unsloppered  only  at 
the  instant  of  plunging  into  it  the  tip  of  the  sulphur  match  which  we  wish  to  kindle. 
Bendix  has  given  the  following  recipe  for  charging  such  match-vials.  Take  one  part 
of  fine  dry  cork  raspings,  one  part  of  yellow  wax,  eight  parts  of  petroleum,  and  four 
of  phosphorus,  incorporate  them  by  fusion,  and  when  the  mixture  has  concreted  by  cooling, 
it  is  capable  of  kindling  a  sulphur  match  dipped  into  it.  Phosi)horus  dissolves  in  fat  oils, 
forming  a  solution  luminous  in  the  dark  at  ordinary  temperatures.  A  vial  half  filled  with 
this  oil'  being  shaken  and  suddenly  uncorked,  will  give  light  enough  to  see  the  dial  of  a 

watch  by  night.  .     .^       .  •  j      «    *v 

There  are  five  combinations  of  phosphorus  and  oxygen  :— 1.  the  white  oxyde  ;  2.  the 
redoxyde;  3.  hypophosphorous  acid;  4.  phosphorous  acid;  5.  phosphoric  acid.  The 
last  is  the  only  one  of  interest  in  the  arts.  It  may  be  obtained  from  the  sirupy 
superphosphate  of  lime  above  described,  by  diluting  it  with  water,  saturating  with  car- 
bonate of  ammonia ;  evaporating,  crystallizing,  and  gently  igniting  the  salt  in  a  retort. 
The  ammonia  is  volatilized,  and  may  be  condensed  into  water  by  a  Woulfe's  apparatus, 
while  the  phosphoric  acid  remains  in  the  bottom  of  the  retort.  Phosphoric  acid  may  be 
more  readily  produced  by  burning  successive  bits  of  phosphorus  in  a  silver  saucer,  under 
a  great  bell  jar  inverted  upon  a  gla-'S  plate,  so  as  to  admit  a  little  air  to  carry  on  the 
combustion.  The  acid  is  obtained  in  a  fine  white  snowy  deposite  ;  consisting,  in  this  its 
dry  state,  of  44  of  phosphorus  and  56  of  oxygen.  That  obtained  from  the  sirupy  so- 
lution is  a  hydrate,  and  contains  9-44  per  cent,  of  water.  If  the  atom  of  phosphorus 
be  called  32  upon  the  hydrogen  radix,  then  5  atoms  of  oxygen  =  40  will  be  associated  with 
it  in  the  dry  acid,  =  72 ;  and  an  additional  atom  of  water  =  9,  in  the  hydrate,  will  make 
its  prime  equivalent  81.    Phosphorous  acid  seems  to  contain  no  more  than  3  atoms  of 

oxygen. 

The  only  salts  of  this  acid  much  in  demand,  are  the  phosphate  of  soda,  and  the  am- 
monia phosphate  of  soda.  The  former  is  prepared  by  slightly  supersaturating  super- 
phosphate of  lime  with  crystals  of  carbonate  of  soda ;  warming  the  solution,  filtering, 
evaporating,  and  crystallizing.  It  is  an  excellent  purgative,  and  not  unpalatable.  The  triple 
phosphate  is  used  in  docimastic  operations  ;  and  is  described  under  Mktallubgy. 

Phosphorus  Amotiphous.  Amorphous  phosphorus  was  discovered  by  Dr.  Schrotter, 
of  Vienna.  It  is  identical  in  composition  with  ordinary  phosphorus,  and  may  be  re- 
converted into  it  without  loss  of  weight,  and  that  merely  by  a  change  of  temperature. 
This  substance  remains  unaltered  in  the  atmosphere,  is  insoluble  in  sulphuret  of  carbon, 
in  alcohol,  ether,  and  naphtha.  It  requires  a  heat  of  260°  C.  to  restore  it  to  the  crys- 
talline state,  and  it  is  only  at  that  heat  that  it  begins  to  take  fire  in  the  open  air.  It  is 
not  luminous  in  the  dark  at  any  ordinary  temperature.  The  apparatus  for  making  it 
consists  of  i  double  iron  pan ;  the  intermediate  space  between  the  two  contains  a  me- 
tallic bath  of  an  alloy  of  tin  and  lead ;  with  a  cast-iron  cover  to  the  inner  vessel,  fitted  to 
the  top  end  by  means  of  a  screw,  and  fastened  to  the  outer  vessel  by  screw  pins.    In  the 


interior  iron  vessel,  a  glass  vessel  is  fitted,  in  which  the  phosphorus  to  be  operated 
upon  is  placed.  From  this  inner  vessel  a  tube  passes,  and  is  dipped  into  water  to  serve 
as  a  safety  valve.  A  spirit  lamp  is  applied  under  that  pipe  if  necessary,  to  prevent 
it  being  clogged  with  phosphorus.  The  phosphorus  to  be  converted  is  first  of  all  melted 
and  then  cooled  under  water,  and  dried  as  much  as  possible.  A  fire  is  now  made  under 
the  other  vessel,  and  the  temperature  raised  to  such  a  degree  as  to  drive  off  the  air,  Ac 
The  temperature  is  to  be  gradually  raised,  until  bubbles  escape  at  the  end  of  the  pipe, 
which  take  fire  as  they  enter  the  air,  and  the  heat  may  soon  rise  in  the  bath  till  rt  be 
500°  Fahr.  This  temperature  must  be  maintained  for  a  certain  time  to  be  determined 
by  experience :  the  apparatus  may  then  be  allowed  to  cool.  The  converted  phosphorus 
is  difficult  to  detach  from  the  glaSft  It  is  to  be  levigated  under  water,  and  then  drained 
in  a  bag.  The  phosphorus  when  moist  should  be  spread  thinly  on  separate  shallow  trap's 
of  sheet  iron  or  lead,  so  placed  alongside  each  other  as  to  receive  the  heat  of  steam,  and 
lastl}'  of  chloride  of  calcium  or  of  sand,  till  the  phosphorus,having  been  frequently  stirred, 
shows  no  more  luminous  vapour.  The  operator  should  have  water  at  hand  to  quench 
any  fire  that  might  arise.  It  is  then  to  be  washed  till  the  water  shows  no  trace  of  acid. 
Should  the  resulting  phosphorus  contain  some  of  the  unconverted  article,  this  may  be 
removed  by  bisulphuret  of  carbon.     Thus,  heat  alone  affects  the  transmutation. 

Phosphorus  and  its  Matches.  Professor  Schrotter's  discovery  of  amorphous  phos- 
phorus has  not  hitherto  led  to  any  practical  application  towards  diminishing  the 
noxiousness  of  the  manufature  of  lucifer  matches;  though  this  curious  substance  may 
now  be  had  at  a  moderate  price  from  Messre.  Sturge  of  Birmingham.  At  Dixon  s 
manufactory,  Newton  Heath,  near  Manchester,  piles  of  timber  are  stored  up  ready  for 
use ;  it  is  rapidly  reduced  into  blocks  of  proper  length,  and  next  into  tiny  sticks,  by 
machinery.  These  are  tied  up  in  bundles  of  about  8  inches  in  diameter,  and  carried 
into  the  sulphuring  room,  where  they  are  dipped  in  the  melted  brimstone  contained  in 
an  iron  pot  resting  over  a  moderate  fire.  Each  bundle  is  turned  round  and  pressed, 
to  prevent  the  cohesion  of  the  sticks  composing  it. 

They  are  now  transferred  to  the  phosphorus  apartment,  where  they  are  dipped  into 
a  composition  of  chlorate  of  potash,  phosphorus  and  glue,  spread  in  a  thin  layer  on  a 
slab  of  stone  or  marble  heated  beneath  b}'  steam  or  hot  water.  The  bundles  are  for  this 
purpose  arranged  in  frames  about  2  feet  long  and  1  broad ;  but  not  in  contact  with  each 
other.  The  operator  holds  the  frame  lengthwise,  and  dips  the  ends  of  the  matches  in 
the  composition,  taking  care  that  all  of  them  are  coated.  They  are  now  sorted  in  a 
separate  room,  and  put  into  boxes.  Each  box  of  lucifer  matches,  price  retail  one  half- 
penny, passes  through  tlie  hands  of  17  persons,  chiefly  children,  who  earn  by  piece- 
work from  3«.  to  5s.  per  week;  while  the  adults  earn  from  9s.  to  I2s. 

The  peculiar  and  most  remarkable  disease  to  which  the  workers  in  such  a  factory 
are  subject  is  described  in  the  Dublin  Quarterly  Journal  of  Science  for  August,  1861, 
by  Mr.  Harrison. 

The  first  symptom  is  toothache,  while  the  jaw  is  getting  into  a  carious  state,  and  the 
disease  silently  creeps  on,  until  the  sufferer  becomes  a  loathsome  object,  or  dies,  be- 
coming unable  to  open  his  jaws,  of  which  the  bones  are  being  necrosed.  Dreadful 
mutilations  ensue,  from  the  necessary  surgical  operations ;  causing  the  loss  of  the 
greater  portion  of  the  lower  jaw.  There  are  at  this  time  in  the  factory  several  per- 
sons who  have  suffered  severely.  In  the  Museum  of  the  Manchester  Infirmary  is  the 
lower  jaw  of  a  young  woman  who  is  now  at  work.  In  some  cases  the  bone  in  its 
diseased  state  has  a  spongy  cellular  appearance,  with  excrescences  of  a  similar  character 
adhering  to  it  The  teeth  generally  continue  sound  and  white,  while  the  jaw  that 
contains  them  is  altered  in  texture  and  apparently  dead.  Loss  of  the  greater  part  or 
whole  of  the  lower  jaw,  is  a  frequent  result  Tlie  cause,  and  cure,  or  prevention  of  this 
horrible  new  disease  are  still  to  be  discovered. 

Phosphorus  paste  for  the  destruction  of  rats  and  mice.  The  Prussian  government 
issued  an  ordonnance  on  the  27th  April,  1843,  directing  the  following  composition  to 
be  substituted  for  arsenic,  for  destroying  rats  and  mice ;  enjoining  the  aul  horities  of 
the  different  provinces  to  communicate,  at  the  expiration  of  a  year,  the  results  of  the 
trials  made  with  it,  with  the  view  of  framing  a  law  on  this  subject 

The  following  is  the  formula  for  this  paste:  — 

Take  of  phosphorus  8  parts,  liquefy  it  in  180  parts  of  lukewarm  water,  pour  the 
-whole  into  a  mortar,  add  immediately  180  parts  of  rye  meal;  when  cold  mix  in  100 
parts  of  butter  melted,  and  126  parts  of  sugar. 

If  the  phosphorus  is  in  a  finely  divided  state,  the  ingredients  may  be  all  mixed  at 
once,  without  melting  them.  ^ 

This  mixture  will  retain  its  efficacy  for  many  years,  for  the  phosphorus  is  preserved 
by  the  butter,  and  only^  becomes  oxidixed  on  the  surface. 

Rats  and  mice  eat  this  mixture  with  avidity ;  after  which  they  swell  out  and  soou 
die. 

8G2 


380 


PHOTOGRAPHY. 


PHOTOGRAPHY. 


381 


i.  i 


M.  Simon  has  employed  this  mixture  for  many  years,  with  eonstant  success,  by 
placing  it  in  places  frequented  by  these  animals.  According  to  him,  the  phosphorus 
18  less  dangerous  than  arsenic,  for  supposing  the  mixture  to  be  bndlv  made,  and  the 
phosphorus  imperfectly  divided,  the  oxidation  which  would  take  place  in  a  few  days 
would  render  it  nearly  inactive ;  and  it  would  be  almost  impossible  to  employ  it  lOT 
the  intentional  poisoning  of  human  beings. 

PHOTOGRAPHY  is  the  art  of  making  pictorial  impressions  of  objects  by  the  action 
of  light  upon  paper,  &c.,  prepared  with  certain  substances,  and  exposed  to  the  sun  or 
in  the  focus  of  a  camera  obscura  to  the  image  of  the  object  to  be  represented ;  which 
impressions  are  then  fixed  by  other  chemical  re-agents.  Photographic  paper  may  be 
made  by  dipping  Whatman's  glazed  post  paper  into*brine  containing  90  grains  of  com- 
mon salt  dissolved  in  an  ounce  of  water,  wiping  it  with  a  towel,  brushing  over  one  side 
of  it  with  a  broad  camel-hair  brush,  a  solution  of  nitrate  of  silver,  containing  50  grains 
to  the  ounce  of  distilled  water,  and  drying  it  in  the  dark.  The  paper  may  be  rendered 
more  sensitive  by  repeating  the  above  operation ;  drying  it  between  each  step.  It 
affords  perfect  images  of  leaves  and  petals  laid  upon  it,  and  exposed  simply  to  the  sun- 
beams. A  solution  of  100  grains  of  bromide  of  potassium  in  an  ounce  of  distilled 
water  answers  still  better  than  brine.  The  paper,  when  dry,  is  to  be  brushed  over  on 
one  side  with  a  solution  containing  100  grains  of  nitrate  of  silver  to  an  ounce  of 
water ;  the  paper  being  brushed,  and  dried  in  the  dark.  If  the  application  of  the  ni- 
trate of  silver  be  repeated,  it  will  render  the  paper  more  sensitive.  The  silvered  side 
should  be  marked.  This  paper  laid  flat  under  painted  glass,  lace,  leaves,  feathers, 
ferns,  &c.,  and  exposed  to  the  light  of  day,  takes  the  impression  of  the  objects.  It  ia 
to  be  then  washed  with  lukewarm  water,  and  finally  dipped  in  a  solution  containing  one 
ounce  of  hyposulphite  of  soda,  in  about  a  pint  of  distilled  water.  The  design  of  the 
object  is  necessarily  reversed  :  the  light  parts  forming  the  dark  shades  of  the  photogenic 
impression,  and  the  dark  parts  the  lighter  ones.  But  a  direct  picture  may  be  obtained 
by  applying  that  paper,  rendered  transparent  with  white  wax  (see  Calotype),  upon 
a  sheet  of  white  photogenic  paper,  and  exposing  it  to  the  sunbeams,  or  bright  day- 
light. 

A  modification  of  Photography,  called  Chrysotype  by  its  inventor,  Sir  John  Herschel, 
consists  in  washing  the  paper  in  a  solution  of  ammonia-citrate  of  iron,  drying  it,  and 
brushing  it  over  with  a  solution  of  ferro-seaquicyanure  of  potassium.  This  paper,  when 
dried  in  a  perfectly  dark  room,  is  ready  for  use,  the  image  being  finally  brought  out  by 
a  neutral  solution  of  silver. 

Another  modification  by  Sir  John,  called  Cyanotype,  is  as  follows  :  Brush  the  paper 
•with  the  solution  of  the  ammonia-citrate  of  iron,  so  strong  as  to  resemble  sherry-wine 
in  color;  expose  the  paper  in  the  usual  way,  and  pass  over  it  very  sparingly  a'^d  evenly 
a  wash  made  by  dissolving  common  ferro-cyanide  of  potassium.  As  soon  as  this  liquid 
is  applied,  the  negative  picture  vanishes,  and  is  replaced  by  the  positive  one,  of  a  violet 
blue  color,  on  a  greenish  yellow  ground,  which  at  a  certain  time  possesses  a  high  de- 
gree of  sharpness,  and  singular  beauty  of  tint. 

The  improved  process  of  photography  recently  contrived  by  Mr.  Robert  Hunt  is  per- 
formed by  washing  over  good  letter-paper  with  the  following  liquid  : — 


A  saturated  solution  of  succinic  acid 
Mucilage  of  gum  arabic    - 
Water        -  -  -  . 


2  drams. 
I  do. 
1|  do. 


When  the  paper  is  dry,  it  is  washed  over  once  with  a  solution  containing  1  dram  of 
nitrate  of  silver  in  1  ounce  of  distilled  water.  The  paper  is  allowed  to  dry  in  the 
dark,  and  it  is  fit  for  use.  It  can  be  preserved  in  a  portfolio,  and  employed  at  any 
time  in  the  camera  obscura,  exposing  it  to  the  light  from  2  to  8  minutes,  according 
to  its  vivacity.  When  the  paper  is  taken  out  of  the  camera,  no  trace  of  a  picture  can 
be  seen.  To  produce  this  effect,  mix  1  dram  of  a  saturated  solution  of  sulphate  of 
iron,  with  2  or  3  drams  of  mucilage  of  gum  arabic,  and  brush  over  the  paper  evenly 
with  this  mixture.  In  a  few  seconds  the  latent  images  are  seen  to  develop  themselves, 
producing  a  negative  photographic  picture.  The  excess  of  the  iron  solution  is  to  be 
washed' off  with  a  sponge  whenever  the  best  effect  appears.  The  drawing  is  then  to  be 
soaked  a  short  time  in  water,  and  is  fixed  by  washing  over  with  ammonia,  or  preferably 
with  hyposulphite  of  soda;  taking  care  to  wash  out  the  excess  of  salt.  From  the 
pictures  thu*.  produced,  any  number  of  others,  corrected  in  light  and  shadow,  may  be 
produced  by  using  like  succinated  papers,  in  the  common  way  of  transfer  in  Bunshiue. 
8ee  also  Calotype,  Daguerreotype  and  Heliography. 

William  Henry  Fox  Talbot,  Esq.,  Laycock  Abbey,  Chippenham,  has  obtained  a  pa- 
tent for  improvements  in  photography.    Patent  dated  June  12th,  1851. 

The  first  part  of  this  invention  consists  in  obtaining  photogi^aphic  images  on  plates 
of  glass  prepared  by  the  following  means : — ^A  plate  of  glass  should  be  selected  having 


a  smooth  and  well  polished  surface;  and  in  order  to  obtain  a  photographic  picture,  the 
operator  proceeds  as  follows : 

1.  Takes  albumen  or  white  of  egg,  and  mixes  the  most  liquid  portions  thereof 
(rejecting  the  rest)  with  an  equal  quantity  of  water,  and  having  spread  the  mixture 
smoothly  and  evenly  over  the  surface  of  the  glass,  allows  it  to  dry  spontaneously,  or 
dries  it  at  a  fire. 

2.  He  mixes  an  aqueous  solution  of  nitrate  of  silver  with  a  large  proportion  of  alcohol, 
go  that  the  mixture  shall  contain  about  3  grains  of  the  nitrate  to  each  ounce  of  liquid. 
(This  proportion  may  be  varied  from  1  to  6  grains  in  the  ounce  of  Hquid ;  but  3  grains 
18  considered  to  be  tne  best  proportion.)  ' 

3.  He  dips  the  prepared  plate  for  a  few  seconds  into  this  mixture,  then  withdraws 
and  dries  it  by  a  gentle  heat,  or  allows  it  to  dry  spontaneously. 

4.  He  dips  the  plate  intd  distilled  water,  to  remove  any  superfluous  nitrate  of  silver. 
6.  He  applies  a  second  coating  of  albumen,  in  the  same  way  as  above  directed,  and 

dries  the  plate  by  the  application  of  gentle  heat,  avoiding  the  use  of  too  much  beat, 
by  which  the  nitrate  of  silver  might  be  decomposed. 

6.  He  takes  an  aqueous  solution  of  protiodide  of  iron,  containing  140  grains  of  pro- 
tiodide  to  the  ounce  of  water.  A  small  quantity  of  free  iodine  in  the  solution,  by 
which  its  colour  would  be  rendered  slightly  yellow,  will  be  found  to  be  of  advantage. 
To  one  measure  of  the  solution,  he  adds  one  of  acetic  acid  and  ten  of  alcohol,  and 
allows  the  mixture  to  stand  for  a  few  days  previous  to  use. 

1.  He  dips  the  plate  into  the  solution,  or  allows  the  liquid  to  pass  over  the  whole 
of  its  surface  in  a  continuous  stream.  It  is  then  dried,  when  it  should  be  of  a  pale  yel- 
low colour,  very  clear,  and  uniformly  transparent;  and  this  completes  the  preparation 
of  the  plates.  All  the  preceding  operations  may  be  performed  in  moderate  daylight, 
but  avoiding  exposure  to  too  strong  a  light,  or  to  sunshine. 

8.  When  it  is  desired  to  obtain  a  photographic  picture,  the  operator  takes  a  solution  of 
nitrate  of  silver  containing  100  grains  of  nitrate  of  silver  to  an  ounce  of  water,  and,  hav- 
ing mixed  two  measures  of  the  same  with  two  of  acetic  acid  and  one  of  water  he  dips 
the  albumenized  plate  therein  once  or  twice,  for  a  few  seconds  each  time  (performing 
the  operation  in  a  darkened  room  or  by  candlelight),  for  the  purpose  of  rendering  it 
sensitive.  If  the  weather  is  cold,  the  plate  should  be  slightly  warmed  before  so  dipping 
it.  He  then  removes  it  to  the  camera  without  loss  of  time,  as  the  plate  ought  to  be 
used  a  few  minutes  after  taking  it  out  of  the  solution ;  and  when  a  sufficiently  strong 
photographic  image  is  supposed  to  be  obtained,  the  plate  ia  transferred  from  tbe  camera 
to  the  dark  chamber  or  operating  room. 

9.  It  is  then  immersed  in  a  solution  of  sulphate  of  iron,  composed  by  mixing  one 
measure  of  a  saturated  solution  thereof  in  water  with  two  measures  of  water  (but  the 
solution  may  be  stronger  or  weaker,  at  the  discretion  of  the  operator,),  by  which  the 
previously  invisible  images  will  be  rapidly  rendered  perceptible. 

10.  The  plate  is  then  washed,  and  dipped  in  a  rather  strong  solution  of  hyposulphite 
of  soda  in  water,  which,  generally,  in  about  a  minute  renders  every  part  of  the  image 
more  distinct  and  visible.  The  picture  is  then  washed  in  distilled  water,  and  the 
surface  of  the  plate  may  be  cleansed  from  any  particles  of  dust,  or  other  impurities, 
by  rubbing  it  gently  with  cotton  dipped  in  water ;  and  if  the  above-described  opera- 
tions have  been  properly  performed,  the  surface  of  the  plate  will  not  be  at  all  injured 
by  this  cleaning.  The  picture  is  then  dried,  and  the  operation  is  finished.  For  the 
purpose  of  better  preserving  the  picture,  the  plate  may  be  covered  with  a  coating  of 
albumen  or  fine  transparent  varnish. 

Although  throughout  the  above  processes  certain  proportions  of  chemical  substances 
have  been  named,  they  may  be  varied  very  considerably,  as  is  also  the  case  in  photo- 
graphic operations  generally. 

The  images  obtained  by  this  improved  method,  Mr.  Talbot  calls  "Amphitypes,"  be- 
cause they  appear  either  positive  or  negative,  according  to  the  circumstances  of  light 
under  which  they  are  viewed.  Thus,  if  held  against  a  bright  light,  or  against  a  sheet 
of  white  paper,  they  appear  negative,  and  the  reverse  when  held  against  a  black  sur- 
face and  seen  in  obliquely  reflected  light  It  is  in  the  power  of  the  operator,  by  vary- 
ing the  proportions  of  the  chemicals  employed,  to  obtain  at  pleasure  positive  images 
more  or  less  distinct  in  comparison  with  the  negative  imarges ;  when  it  is  intended  to 
copy  the  image  upon  paper,  it  is  desirable  to  obtain  as  strong  a  negative  as  possible 
on  the  glass  plate,  which  is  then  copied  on  the  paper,  to  produce  thereon  a  positive 
image  in  the  usual  manner ;  but  when  the  operator  wishes  to  have  a  picture  on  the 
glass,  he  should  endeavour  to  obtain  a  strong  positive  image.  When  this  is  obtained 
to  his  satisfaction,  it  may  be  preserved  from  injary  and  from  contact  with  the  air,  by 
pouring  black  paint  over  the  pictured  side  of  the  plate,  and  then  by  turning  the  glass 
the  picture  will  be  seen  correctly,  and  not  reversed  as  regards  the  right  and  left  sides. 
This  method  of  blacking  one  side  of  the  plate  is  not,  however,  any  part  of  the  present  in 


:1 


H 


d82 


PHOTOGRAPHY. 


PICKLES. 


383 


vention.  Throughout  the  specification  the  words  negative  and  positive  are  made  use  of  in 
the  senses  in  which  they  are  generally  employed  by  photographers,  viz.,  a  positive  image 
is  that  in  which  the  lights  and  shades  of  the  object  are.  represented  by  lights  and  shades 
in  the  photograph,  and  a  negative  image  is  that  in  wliich  a  reverse  effect  is  produced. 

The  method  of  operating  just  described  is  that  which  Mr.  Talbot  recommends  when 
the  object  is  close  at  hand,  and  the  operator  is  in  the  vicinity  of  a  darkened  room,  to 
which  he  can  retire  for  the  purpose  of  rendering  his  plates  sensitive  ;  but  under  circum- 
stances where  the  object  is  at  a  distance,  and  when  the  operator  is  on  a  journey  or 
otherwise  removed  from  any  house  or  place  where  such  conveniences  exist,  the  following 
method  of  procedure  may  be  adopted:— The  operator  constructs  a  glass  cell  with  equal 
and  parallel  sides,  open  at  the  top  and  closed  at  the  bottom  and  sides,  and  quite  water- 
tight, of  a  size  just  sufficient  to  receive  one  of  the  photographic  plates,  but  not  much 
greater,  in  order  that  there  may  be  no  waste  of  the  chemicals  employed.    The  posterior 
glass  of  the  cell  has  one  of  its  sides  ground  or  unpolished,  and  the  cell,  when  m  use,  is 
placed  at  the  hinder  part  of  the  camera,  so  that  when  directed  towards  an  object,  the 
unpolished  or  ground  surface  may  answer  the  purpose  of  the  sheet  of  ground  glass  in- 
troduced in  cameras  to  place  the  objects  in  their  true  focus.     Allowance  must,  of  course, 
be  made  for  the  unusual  position  occupied  by  the  ground  glass  in  this  case.     The  top 
of  the  cell  is  provided  at  one  corner  with  a  funnel  for  the  introduction  of  liquid,  and  the 
bottom  is  furnished  with  a  stopcock  and  waste  pipe  terminating  in  a  caoutchouc  tube, 
which  may  be  moved  by  hand  from  one  to  the  other  of  two  vessels  which  are  provided 
to  receive  the  used  liquors  escaping  from  the  camera :  the  nitrate  of  silver  solution  is  too 
expensive  to  be  wasted,  but  the  other  ingredients,  when  once  used,  may  be  thrown  away. 
These  preparations  made,  the  operator  pours  into  the  cell  a  quantity  of  liquid  sufficient 
to  fill  u.  nearly  full  when  it  contains  one  of  the  photographic  plates,  and  notes  the 
quantity  required.     lie  then  provides  four  bottles  of  that  capacity,  one  of  which  he  fills 
with  solution  of  nitrate  of  silver,  prepared  as  before  directed  under  operation  8. ;  the 
second  bottle  is  to  contain  a  solution  of  sulphate  of  iron,  as  directed  under  operation 
9. ;   the  third  bottle  is  filled  with  water,  and  the  fourth  with  a  strong  solution  of 
hyposulphite  of  soda.    These  quantities  are  sufficient  for  obtaining  a  single  photographic 
picture,  and  when  they  are  used,  the  bottles  must  be  filled  again.     Having  prepared  a 
number  of  glass  plates  by  means  of  processes  before  described,  up  to  No.  7.  inclusive, 
they  are  to  be  packed  in  a  box  ready  for  use  :  the  operator,  when  he  desires  to  obtain  a 
photographic  picture  of  an  object,  takes  one  of  the  plates  from  the  box  (which  he  can  do 
without  injury  to  it,  as  the  plates  in  this  condition  are  not  sensitive  to  light),  and  place 
it  in  the  camera,  the  focus  of  which  he  adjusts  to  the  object     He  then  closes  the  front 
lens  or  object  glass,  lowers  a  curtain  over  the  camera  box,  leaving  exposed  only  the 
funnel  at  the  top  (and  care  should  be  taken  to  guard  against  any  light  entering  through 
this),  and  the  waste  pipe  at  the  bottom  of  the  cell,  and  pours  into  the  cell,  through  the 
funnel,  the  contents  of  the  first  bottle  (nitrate  of  silver  solution),  for  the  purpose  of 
rendering  the  plate  sensitive  to  light.     He  may  then  proceed  in  two  different  ways. 
That  is,  he  may  open  the  front  lens,  and  obtain  the  image  while  the  plate  is  immersed 
in  the  solution ;  or,  before  opening  the  front  lens,  he  may  allow  the  nitrate  of  silver 
solution  to  escape  through  the  waste  pipe,  and  he  will  then  obtain  an  image  on  the  plate 
while  the  liquid  is  adhering  to  its  sides.     In  the  latter  case,  or  after  allowing  the  solu- 
tion to  escape,  if  the  former  method  is  adopted,  he  closes  the  stopcock,  and  succes- 
sively pours  into  the  cell  the  contents  of  the  second  and  third  bottles,  allowing  each 
to  remain  in  for  about  half  a  minute  ;  and,  finally,  he  pours  in  the  hyposulphite  of  soda 
solution,  after  which  the  plate  is  removed,  and  the  image  being  now  fixed,  and  not  liable 
to  injury  from  exposure  to  air,  the  plate  is  washed  and  placed  in  a  box  to  be  finished 
and  varnished  when  the  day's  operations  are  completed.     Another  method,  but  one 
which  is  less  simple,  is  to  use  four  bottles  of  larger  size  than  those  above  described, 
but  containing  the  same  liquids.    These  bottles  are  placed  on  a  stand  above  the  camera, 
and  from  each  of  them  descends  a  tube  of  India  rubber  furnished  with  two  stopcocks, 
which  are  placed  at  such  distances  apart,  that  the  interval  of  tube  between  them  shall 
be  of  a  capacity  equal  to  that  of  the  cell  when  it  contains  a  plate.     These  tubes  dip 
into  a  funnel  which  communicates  by  a  suitable  pipe  with  the  funnel  leading  to  the  cell. 
The  liquids  are  successfully  supplied  to  the  cell  from  the  bottles,  and  the  method  of 
operating  according  to  this  system  is  the  same  as  that  just  described.    The  images 
obtained  on  glass  by  these  means  may  be  copied  on  to  paper,  in  the  usual  manner. 
In  fixing  the  images  on  paper,  it  is  recommended,  after  washing  them,  to  immerse  the 
paper  in  a  hot  solution  of  iodide  of  potassium  before  dipping  in  the  solution  of  hypo* 
sulphite  of  soda  ;  by  which  means  a  better  fixation  of  the  image  will  be  obtained. 

Under  this  branch  of  his  invention,  Mr.  Talbot  claims  the  mode  of  preparing  the  glass 
plates,  especially  the  use  of  a  weak  solution  of  nitrate  of  silver,  immediately  after  the 
first  coating  of  albumen ;  also  the  conjoint  use  of  protiodide  of  iron  and  sulphate  of  iron, 
upon  albumenized  glass  plates ;  and  also  the  simultaneous  production  upon  glass  platef 


of  images  which  are  both  positive  and  negative,  according  to  the  light  in  which  they 
are  viewed.  (In  the  specification  of  a  patent  granted  to  Messrs.  Malone  and  Talbo^ 
I9th  Dec.  1849,  a  method  is  described  of  producing  such  images,  which  differs  from  the 
present  in  the  prior  formation  of  the  negative  image,  which  is  afterwards  converted 
into  a  positive  one.)  Also  the  apparatus  described  to  be  used  along  with  the  camera 
enabling  the  operator  to  work  without  the  necessity  of  darkening  the  apartment  in 
which  he  works,  or  of  employing  a  tent  or  other  contrivance  for  working  in  the  shade, 
when  taking  photographic  pictures  at  a  distance  from  any  house.  The  form  of  the 
apparatus  may  be  considerably  varied,  but  the  essential  point  is,  that  the  glass  plate 
is  placed  in  the  cell  in  a  partly  prepared  state,  in  which  it  is  insensible  to  light,  and 
is  not  removed  from  the  cell,  until  the  photographic  picture  is  finished,  with  the  excep- 
tion of  the  final  washing  and  drying.  The  patentee  does  not  claim  as  new  the  mere 
use  of  a  glass  cell  containing  nitrate  of  silver,  into  which  the  photographic  plate  is 
dropped  previous  to,  or  during  the  formation  of  the  image ;  but  he  claims  the  addition 
of  the  stopcock  and  waste-pipe,  and  the  general  arrangements,  which  render  unne- 
cessary the  removal  of  the  plate  from  the  cell  before  the  picture  is  finished.  He 
states,  also,  that  he  believes  the  arrangement  of  four  vessels  furnished  with  tubes  and 
stopcocks  for  pouring  measured  quantities  of  different  fluids  into  the  glass  cell  to  be 
a  new  one. 

The  second  pait  of  the  invention  consists  of  a  method  of  obtaining,  under  certain 
circumstances,  the  photographic  picture  of  objects  which  are  in  rapid  motion.  An 
electric  battery  of  the  greatest  power  which  can  be  conveniently  obtained,  is  arranged 
in  a  darkened  room,  and,  supposing  the  moving  body  whose  picture  is  required  is  a 
wheel  revolving  upon  its  axis,  the  camera  is  placed  at  a  convenient  distance  from  it, 
and  adjusted  so  as  to  have  the  image  of  the  object  in  its  focus.  A  glass  plate  is  then 
taken,  which  has  been  previously  prepared,  in  the  way  described  above,  and  it  is  ren- 
dered sensitive  with  nitrate  of  silver  in  the  way  also  above  described :  it  is  then  placed 
in  the  camera  and  the  electric  battery  is  discharged,  producing  a  sudden  flash  of  light, 
which  illuminates  the  object ;  the  image  thus  taken  on  the  glass  plate  is  then  ren- 
dered visible,  and  the  process  finished,  as  before  directed.  If  the  process  is  properly 
conducted,  a  distinct  positive  image  of  the  moving  body  will  be  seen  upon  the  glass, 
the  rapidity  of  the  motion  not  affecting  the  accuracy  of  the  delineation. 

What  is  claimed  under  this  head  of  the  invention  is  the  use  of  the  instantaneous 
light  of  an  electric  battery  in  such  a  way  as  to  obtain  the  photographic  image  of  a 
body  illuminated  thereby. 

PICAMARE,  is  a  thick  oil,  one  of  the  six  new  principles  detected  by  M.  Reichen- 
bach  in  wood-tar.  See  Creosote  and  Paraffine.  Picamare  constitutes  l-6th  of 
beech-tar. 

PICKLES  are  various  kinds  of  vegetables  and  fruits  preserved  in  vinegar.  The 
substances  are  first  well  cleaned  with  water,  then  steeped  for  some  time  in  brine,  and 
afterward  transferred  to  bottles,  which  are  filled  up  with  good  vinegar.  Certain  fruits, 
like  walnuts,  require  to  be  pickled  with  scalding-hot  vinegar ;  others,  as  red  cabbage, 
with  cold  vinegar ;  but  onions,  to  preserve  their  whiteness,  with  distilled  vinegar.  Wood 
vinegar  is  never  used  by  the  principal  pickle-manufacturers,  but  the  best  malt  or  white- 
wine  vinegar,  No.  22  or  24.  Kitchener  says,  that  by  parboiling  the  pickles  in  brine, 
they  will  be  ready  in  half  the  time  of  what  they  require  when  done  cold.  Cabbage, 
however,  cauliflowers,  and  such  articles,  would  thereby  become  flabby,  and  lose  that 
crispness  which  many  people  relish.  When  removed  from  the  brine,  they  should  be 
cooled,  drained,  and  even  dried,  before  being  put  into  the  vinegar.  To  assist  the  pres- 
ervation of  pickles,  a  portion  of  salt  is  often  added,  and  likewise,  to  give  flavor,  various 
spices,  such  as  long  pepper,  black  pepper,  white  pepper,  allspice,  ginger,  cloves,  mace, 
garlic,  mustard,  horseradish,  shallots,  capsicum.  When  the  spices  are  bruised,  they 
are  most  efficacious,  but  they  are  apt  to  render  the  pickle  turbid  and  discolored.  The 
flavoring  ingredients  of  Indian  pickle  are  Curry  powder  mixed  with  a  large  proportion 
of  mustard  and  garlic.  Green  peaches  are  said  to  make  the  best  imitation  of  the  Indian 
mango. 

I  have  examined  the  apparatus  in  the  great  fish-sauce,  pickle,  and  preserved-fruit 
establishment  of  Messrs.  Crosse  and  Blackwell,  Soho  square,  and  found  it  arranged  on 
the  principles  most  conducive  to  economy,  cleanliness,  and  salubrity  ;  no  material  em- 
ployed there  is  ever  allowed  to  come  into  contact  with  copper.  A  powerful  steam-boiler 
is  placed  in  one  corner  of  the  ground  floor  of  the  factory,  from  which  a  steam-pipe  is- 
sues, and  is  laid  horizontally  along  the  wall  about  4  feet  above  the  floor.  Under  this 
pipe  a  range  of  casks  is  placed,  into  the  side  of  each  of  which  a  branch  steam-pipe,  fur- 
nished with  a  stop-cock,  is  inserted,  while  the  mouth  of  the  cask  is  exactly  closed  with 
a  pan  of  salt-glazed  earthenware,  capable  of  resisting  the  action  of  ever>'  acid,  and 
incapable  of  communicating  any  taint  to  its  contents.  These  casks  form,  by  their  non- 
conducting quality  as  to  heat,  the  best  kind  of  steam-jackets.  In  these  pans  the  vine- 
gars with  their  compounds  are  heated,  and  the  fish  and  other  sauces  are  prepared. 


(^ 


884 


PIMENTO. 


PIN  MANUFACTURE. 


385 


1 

t 

1 

1 

The  waste  steam  at  the  farthest  extremity  of  the  pipe  is  conducted  into  a  reservoir  of 
clean  water,  so  as  to  farnish  a  constant  supply  of  hot  water  for  washing  bottles  and 
utensils. 

The  confectionary  and  ham-smoking  compartments  are  placed  in  a  separate  fireproof 
chamber  on  the  same  floor. 

The  floor  above  is  occupied  along  the  sides  with  a  range  of  large  rectangular  cast 
iron  cisterns,  furnished  with  a  series  of  steam-pipes,  laid  gridironwise  along  their  bot- 
toms, which  pipes  are  covered  with  a  perforated  wooden  shelf.  These  cisterns  being 
filled  up  to  a  certain  height  above  the  shelf  with  water,  the  bottles  full  of  green  goose- 
berries, apricots,  cherries,  &c.,  to  be  preserved,  are  set  upon  the  shelf,  and  the  steam 
being  then  admitted  into  the  gridiron  pipes,  the  superjacent  water  gets  gradually  heated 
to  the  boiling  point ;  the  air  in  the  bottles  round  the  fruit  is  thus  partly  expelled  by 
expansion,  and  partly  disoxygenated  by  absorption  of  the  green  vegetable  matter.  In 
this  state  the  bottles  are  tightly  corked,  and  being  subsequently  sealed,  preserve  the 
fiuit  fresh  for  a  very  long  period. 

The  sauces,  pastes,  and  potted  meats,  prepared  in  the  above-described  apparatus,  can 
seldom  be  rivalled  and  probably  not  surpassed  in  the  kitchens  of  the  most  fastidious 
gastronomes. 

PICROMEL,  is  the  name  given  by  M.  Thenard  to  a  black  bitter  principle  which  he 
supposed  to  be  peculiar  to  the  bile.  MJVL  Gmelin  and  Tiedemann  have  since  called 
its  identity  in  question. 

PICROTOXINE,  is  an  intensely  bitter  poisonous  vegetable  principle,  extracted  from 
the  seeds  of  the  Menispermum  cocculus,  (Cocculus  Indicus.)  It  crystallizes  in  small 
white  needles,  or  columnsj  dissolves  in  water  and  alcohol  It  does  not  combine  with 
acids,  but  with  some  base^  and  is  not  therefore  of  an  alkaline  nature,  as  had  been  at 
first  supposed. 

PIGMENTS,  VITRIFTABLE,  belong  to  five  different  styles  of  work  :  1.  to  enamel 
painting ;  2.  to  painting  on  metals ;  3.  to  painting  on  stoneware ;  4.  to  painting  on 
porcelain  ;  5.  to  stained  glass.     See  VrraiFiABLE  Pigments. 

PIGMENTS.  1.  White.  Alumina,  white  clay,  heavy  spar,  chalk,  gypsum,  alabaster, 
and  starch,  and  sulphate  of  lead. 

2.  Blues,  Lapis  lazuli  blue ;  azure  blue ;  artificial  ultramarine ;  Thenard's  blue  or 
cobaltic ;  Giessen  blue  is  Prussian  blue  dissolved  in  oxalic  acid. 

Copper  blue,  or  hydrated  oxide  of  copper,  called  mountain  blue ;  indigo ;  litmus 
blue ;  blue  (violet)  from  logwood  by  salt  of  tin  and  alkalis. 

3.  Green.  Bremer;  hydrated  oxide  of  copper  by  decomposing  a  salt  of  copper  with 
alkali ;  Brunswick  and  mountain  green  are  arsenites  of  copper,  acetate  of  copper  or 
verdigris ;  Scheele's  green ;  mixtures  of  chrome  yellow  and  Prussian  blue ;  oxide  of 
chrome  as  an  enamel  colour ;  green  earth,  silicate  and  phosphate  of  the  protoxide  of 
iron ;  vegetable  green,  an  extract  of  buckthorn  berries,  called  also  sap-green. 

4.  Yellow.  Chrome ;  yellow  antimonite  of  lead  or  Naples  yellow,  orpiment ; 
hydrated  oxide  of  iron;  yellow  ochre  or  Sienna  yellow;  gamboge;  turmeric;  yeUow 
wood  or  fustic ;  quercitron ;  weld ;  yellow  berries ;  saffron ;  annotto. 

Red  pigments.  Cinnabar ;  basic  chromate  of  lead ;  red  lead ;  oxide  of  iron ;  red 
lake  dyes  ;  carmine ;  cochineal ;  kermes ;  Brazil  wood ;  madder  and  its  lake ;  lac  lake  ; 
alkanet  root ;  sandal  wood ;  safilower ;  umber,  or  earthy  clay  ironstone ;  Cologne 
umber ;  earthy  brown  coal,  lamp  black,  and  Frankfort  vine  black  ;  bone  black  ;  sepia, 
obtained  by  drying  the  black  fluid  of  the  cuttle-fish,  extracted  by  means  of  caustic  lye ; 
catechu  ;  dyes  with  mordants. 

PIMENTO  {Myrtiis  pimentOf  or  Jamaica  pepper)  consists,  according  to  Bonastre*! 
complicated  analysis,  of— 


Shells  or  capsules. 

Kernels. 

Volatile  oil    - 

10-0 

50 

Soft  green  resin     >            .            . 

80 

2-5 

Fatty  concrete  oil       -           •            •           • 

0^ 

1-2 

Extract  containing  tannin             •           •           • 

11-4 

39-8 

Gum                --.••• 

3-0 

7-2 

Brown  matter  dissolved  in  potash 

4*0 

8-0 

Resinoid  matter         -           .           •           •           . 

1-2 

3-2 

Extract  conlainin?  sugar  .            .            •            • 

3*0 

8-0 

Gallic  and  malic  acids            .... 

0-6 

1-6 

Vegetable  fibre     -            -            .           «           . 

600 

16-0 

Ashes  charged  with  salts       .... 

2*8 

1-9 

Moisture  and  loss               -           -            -            . 

41 

4-8 

I      Imported. 


1850 
1851 


acts. 
20,448 
14,840 


Retained  for  Consumption. 


ctots. 
3564 
3935 


Exported. 


ctots. 

8,510 

1*7,363 


Duty  Receired. 


£ 
936 

loss 


PINCHBECK,  is  a  modification  of  brass ;  see  that  article  and  Coppkr. 

PINE-APPLE  YARN  and  CLOTH.  In  Mr.  Zincke's  process,  patented  in  Decem- 
ber, 1836,  for  preparing  the  filaments  of  this  plant,  the  Bromelia  ananas,  the  leaves  being 
plucked,  and  deprived  of  the  prickles  round  their  edges  by  a  cutting  instrument,  are 
then  beaten  upon  a  wooden  block  with  a  wooden  mallet,  till  a  silky-lookin?  mass  of 
fibres  be  obtained,  which  are  to  be  freed  by  washing  from  the  green  fecula.  The  fibrous 
part  must  next  be  laid  straight,  and  passed  between  wooden  rollers.  The  leaves  should 
be  gathered  between  the  time  of  their  full  maturity  and  the  ripening  of  the  fruit.  If 
earlier  or  later,  the  fibres  will  not  be  so  flexible,  and  will  need  to  be  cleared  by  a  boil  in 
soapy  water  for  some  hours ;  after  being  laid  straight  under  the  pressure  of  a  wooden 
grating,  to  prevent  their  becoming  entangled.  When  well  washed  and  dried,  with  occa- 
sional shaking  out,  they  will  now  appear  of  a  silky  fineness.  They  may  be  then  spun 
into  porous  rovings,  in  which  state  they  are  most  conveniently  bleached  by  the  onlinary 
methods. 

Specimens  of  cambric,  both  bleached  and  unbleached,  woven  with  these  fibres,  have 
been  recently  exhibited,  which  excited  hopes  of  their  rivalling  the  finest  flax  fabrics,  but 
in  my  opinion  without  good  reason,  on  account  of  their  want  of  strength. 

PINEY  TALLOW  is  a  concrete  fal  obtained  by  boilmg  with  water  the  fruit  of  the 
Vateria  indica,  a  tree  common  upon  the  Malabar  coast.  It  seems  to  be  a  substance  in- 
termediate between  tallow  and  wax;  pa. taking  of  the  nature  of  stearine.  It  melts  at 
97|«  F.,  is  white  or  yellowish,  has  a  spec.  grav.  of  0-926 ;  is  saponified  by  alkalis,  and 
forms  excellent  candles.  Dr.  Benjamin  Babington,  to  whom  we  are  indebted  for  all  our 
knowledge  of  piney  tallow,  found  its  ultimate  constituents  to  be,  77  of  carbon,  12-3  of 
hydrogen,  and  10'7  of  oxygen. 

PIN  MANUFACTURE.  (Fabrique  (Pepingles,  Fr. ;  NadeJfabrik,  Germ.)  A  pin  is 
a  small  bit  of  wire,  commonly  brass,  with  a  point  at  one  end,  and  a  spherical  head  at  the 
other.     In  making  this  little  article,  there  are  no  less  than  fourteen  distinct  operations. 

1.  Straightening  the  wire.  The  wire,  as  obtained  from  the  drawing-frame,  is  wound 
about  a  bobbin  or  barrel,  about  6  inches  diameter,  which  gives  it  a  curvature  that  must 
be  removed.  The  straightening  engine  is  formed  by  fixing  6  or  7  nails  upright  in  a 
waving  line  on  a  board,  so  that  the  void  space  measured  in  a  straight  line  between  the 
first  three  nails  may  have  exactly  the  thickness  of  the  wire  to  be  trimmed  ;  and  that  the 
other  nails  may  make  the  wire  take  a  certain  curve  line,  which  must  vary  with  its  thick- 
i»€83.  The  workman  pulls  the  wire  with  pincers  through  among  these  nails,  to  the  length 
of  about  30  feet,  at  a  running  draught ;  and  after  he  cuts  that  off,  he  returns  for  as  much 
more ;  he  can  thus  finish  600  fathoms  in  the  hour.  He  next  cuts  these  long  pieces  into 
engths  of  3  or  4  pins.  A  day's  work  of  one  man  amounts  to  18  or  20  thousand  dozen 
of  pin-lengths. 

2.  Pointing  is  executed  on  two  iron  or  steel  grindilones,  by  two  workmen  one  of 
whom  roughens  down,  and  the  other  finishes.  Thirty  or  forty  of  the  pin  wires  are  ap- 
plied to  the  grindstone  at  once,  arranged  in  one  plane,  between  the  two  forefingers  and 
thumbs  of  both  hands,  which  dexterously  give  them  a  rotatory  movement. 

3.  Cutting  these  wires  into  pin-imgths.  This  is  done  by  an  adjusted  chisel.  The  inter 
mediate  portions  are  handed  over  to  the  pointer. 

4.  Twisting  of  the  wire  for  the  pinJuads,  These  are  made  of  a  much  finer  wire,  coiled 
into  a  compact  spiral,  round  a  wire  of  the  size  of  the  pins,  by  means  of  a  smaU  hithe 
constructed  for  the  purpose. 

5.  Cutting  the  heads.  Two  turns  are  dexterously  cut  off  for  each  head,  by  a  regulated 
chisel.    A  skilful  workman  may  turn  off  12,000  in  the  hour. 

6.  Jnnealing  the  heads.  They  are  put  into  an  iron  ladle,  made  redhot  over  an  open 
fire,  and  then  thrown  mto  cold  water. 

7.  Stamping  or  shaping  the  heads.  This  is  done  by  the  blow  of  a  small  ram,  raised  to 
means  of  a  pedal  lever  and  a  cord.  The  pin-heads  are  also  fixed  on  by  the  same  operative, 
who  makes  about  1500  pms  in  the  hour,  or  from  12,000  to  15,000  per  diem :  exclusive  of 
one  thirteenth,  which  is  always  deducted  for  waste  in  this  department,  as  well  as  ia  the 
rest  of  the  manufacture.  Cast  heads,  of  an  alloy  of  tin  and  antimony,  were  introduced 
by  patent,  but  never  came  into  general  use. 

8.  Yellowing  or  cUaning  the  pins  is  efi-ected  by  boiling  them  for  half  an  hour  in  sonr 
beer,  wme  lees,  or  soluUon  of  tartar  j  after  which  they  are  washed. 


386 


PINS. 


PITCH. 


387 


III 


4i 


■     ■'>     ,11  ■  1 


9.  Whitening  or  tinning.  A  stratum  of  about  6  pounds  of  pins  is  laid  in  a  copper  pan, 
.hen  a  stratum  of  about  7  or  8  pounds  of  grain  tin  ;  and  so  alternately  till  the  vessel  be 
filled  ;  a  pipe  being  left  inserted  at  one  side,  to  permit  the  introduction  of  water  slowly 
at  the  bottom,  without  deranging  the  contents.  When  the  pipe  is  withdrawn,  its  space  is 
filled  up  with  grain  tin.  The  vessel  being  now  set  on  the  fire,  and  the  water  becoming 
hot,  its  surface  is  sprinkled  with  4  ounces  of  cream  of  tartar ;  after  which  it  is  allowed 
to  boil  for  an  hour.     The  pins  and  tin  grains  are,  lastly,  separated  by  a  kind  of  cullender. 

10.  Washing  the  pins  in  pure  water. 

11.  Drying  and  polishing  them,  in  a  leather  sack  filled  with  coarse  bran,  which  is  agi- 
tated to  and  fro  by  two  men. 

12.  Winnowing,  by  fanners. 

13.  Pricking  the  papers  for  receiving  the  pins. 

14.  Papering,  or  fixing  them  in  the  paper.  This  is  done  by  chiklren,  who  acquire  the 
habit  of  putting  up*  36,000  per  day. 

The  pin  manufacture  is  one  of  the  greatest  prodigies  of  the  division  of  labor;  it  fur- 
nishes 12,000  articles  for  the  sum  of  three  shillings,  which  have  required  the  united 
diligence  of  fourteen  skilful  operatives. 

The  above  is  an  outline  of  the  mode  of  manufacturing  pms  by  hand  labor,  but  several 
beautiful  inventions  have  been  employed  to  make  them  entirely  or  in  a  great  measure 
by  machinery ;  the  consumption  for  home  sale  and  export  amounting  to  15  millions 
daily,  for  this  country  alone.  One  of  the  most  elaborate  and  apparently  complete  is 
thai  for  which  Mr.  L.  W.  Wright  obtained  a  patent  in  May,  1824.  A  detailed 
description  of  it  will  be  found  in  the  9th  volume  of  Newton's  London  Journal.  The 
following  outline  will  give  my  readers  an  idea  of  the  structure  of  this  ingenious 
machine : — 

The  rotation  of  a  principal  shaft,  mounted  with  several  cams,  gives  motion  to  various 
sliders,  levers,  and  wheels,  which  work  the  diflTerent  parts.  A  slider  pushes  pincers  for- 
wards,  which  draw  wire  from  a  reel,  at  every  rotation  of  the  shaft,  and  advance  such  a 
length  of  wire  as  will  produce  one  pin.  A  die  cuts  off  the  said  length  of  wire  by  the 
descent  of  its  upper  chap ;  the  chap  then  opens  a  carrier,  which  takes  the  pin  to  the 
pointing  apparatus.  Here  it  is  received  by  a  holder,  which  turns  round,  while  a  bevel- 
edged  file-wheel  rapidly  revolves,  and  tapers  the  end  of  the  wire  to  a  point.  The  pin  is 
now  conducted  by  a  second  carrier  to  a  finer  file-wheel,  in  order  to  finish  the  point  by  u 
$econd  grinding.  A  third  carrier  then  transfers  the  pin  to  the  first  heading  die,  and  by 
llie  advance  of  a  steel  punch,  the  end  of  the  pin  wire  is  forced  into  a  recess,  whereby  the 
head  is  partially  swelled  out.  A  fourth  carrier  removes  the  pin  to  a  second  die,  where 
the  heading  is  perfected.  When  the  heading-bar  retires,  a  forked  lever  draws  the 
finished  pin  from  the  die,  and  drops  it  into  a  receptacle  below. 

I  believe  the  chief  objection  to  the  raising  of  the  heads  by  strong  mechanical  com- 
pression upon  the  pins,  is  the  necessity  of  softening  the  wire  previously ;  wherel)y  the 
pins  thus  made,  however  beautiful  to  the  eye,  are  deficient  in  that  stiffness  which  is  so 
essential  to  their  employment  in  many  operations  of  the  toilet. 

Edelsten,  and  Williams,  New  Hall  Works,  Birmingham,  Manufacturers.  Pins,  the  heads 
and  shafts  being  formed  of  one  solid  piece  of  metal,  in  order  to  render  the  head  im- 
moveable and  smooth  in  use,  made  by  improved  machinery.  Model  dies  to  show  the 
formation  of  the  head.  Elastic  hair-pins.  Specimens  of  iron  wire  in  various  sizes. 
In  pin  making  the  wire  is  brass  (a  compound  of  copper  and  zinc) :  it  is  reduced  by  the 
ordinary  process  of  wire  drawing  to  the  requisite  thickness:  in  this  process  it  is  necessa- 
rily curved.  To  remove  this  it  is  re-wound,  and  pulled  through  between  a  number  of  pina 
arranged  at  the  draw  or  straightening  bench ;  it  is  then  cut  into  convenient  lengths  for 
removal,  and  finally  reduced  to  just  such  a  length  as  will  make  two  pins.  The  pointing 
is  done  upon  steel  mills  (revolving  wheels),  the  circumference  of  whicn  is  cut  with  teeth, 
the  one  fine,  the  other  coarse.  Thirty  or  forty  lengths  are  packed  up  at  once,  and,  as 
in  needle-making,  the  cast  of  hand  given  by  the  workman  makes  them  revolve,  and  the 
whole  are  pointed  at  once  ;  the  same  operation  is  performed  with  the  other  end.  The 
process  of  heading  is  next  performed  as  follows :  a  number  of  the  pointed  wires  now 
cut  in  two,  are  placed  in  the  feeder  of  the  machine ;  one  drops,  is  firmly  seized,  and,  by 
means  of  a  pair  of  dies,  a  portion  of  the  metal  is  forced  up  into  a  small  bulb ;  by  a 
beautifully  simple  and  automatic  arrangement,  it  is  passed  into  another,  when  a  small 
horizontal  hammer  gives  it  a  sharp  tap,  which  completes  the  head.  The  white  colour 
is  produced  by  boiling  in  a  solution  of  cream  of  tartar  and  tin.  They  are  then  dried, 
and  passed  into  the  hands  of  the  wrappers-up.  The  preparation  or  marking  of  the 
paper  is  peculiar,  and  is  done  by  means  of  a  moulded  piece  of  wood,  the  moulds  corre- 
sponding to  those  portions  which  represent  the  small  folds  of  paper  through  which  the 
pins  are  passed,  and  thereby  held.    The  pins  are  then  taken  to  the  paperers,  who  are 


each  seated  in  front  of  a  bench,  to  which  is  attached  a  horizontally  hinged  piece  of  iron 
the  edge  of  which  is  notched  with  a  corresponding  number  of  marks  to  the  number  of 
pins  to  be  struck ;  the  small  catch  which  holds  together  the  two  parts  of  the  iron  is 
released,  the  paper  introduced,  and  a  pin  inserted  at  every  mark ;  the  paper  is  then  re- 
leased, and  the  task  of  examination  follows,  which  is  the  work  of  a  moment.  The  paper 
of  pins  is  held  so  that  the  light  strikes  upon  it :  those  defective  are  immediately  detected 
by  the  shade,  are  taken  ou^  and  others  substituted  in  their  stead.  An  ancient  edict  of 
Henry  VIII.,  held  that,  "  no  one  should  sell  any  pins  but  such  as  were  double-headed, 
and  the  heads  soldered  fast  on.** 

Pins,  Improved. — The  selection  and  preparation  of  the  wire. — ^The  iron  or  steel  wire 
employed  should  be  very  round,  and,  to  protect  it  from  rust,  it  should  at  the  last  drawing 
be  lubricated  by  means  of  a  sponge  saturated  with  oil,  placed  between  the  draw-plate 
and  reel.  In  all  the  subsequent  stages  of  the  manufacture,  care  should  also  be  taken 
to  preserve  the  pins  from  oxidation  by  keeping  them  well  oiled  and  greased. 

The  cleansing  and  polishing. — The  wire  being  cut  into  pins,  and  these  headed  and 
pointed,  all  according  to  the  usual  methods,  the  pins  are  thrown  into  a  revolving  cylinder 
of  wood  containing  a  bath  of  soap  and  water  in  a  hot  state.  It  is  of  the  capacity  of 
about  9^  gallons,  but  should  not  contain  more  than  about  1^  gallons  of  water,  with 
about  2  ounces  of  soap  dissolved  therein,  as  this  quantity  will  be  suflScient  for  the  treat- 
ment of  about  13^  lbs.  weight  of  pins  at  a  time.  The  cylinder,  when  thus  charged,  is 
made  to  revolve  for  about  a  quarter  of  an  hour ;  at  the  expiration  of  which  time  the 
pins  are  found  free  from' the  oil  with  which  they  were  previously  coated,  and  also  very 
much  smoothed  and  polished  by  their  rubbing  one  against  the  other. 

The  drying.  The  pins  are  next  dried  by  transferring  them  to  another  cylinder  par- 
tially filled  with  well  dried  sawdust  (preferring  for  the  purpose  the  sawdust  of  poplar 
wood),  and  causing  this  cylinder  to  revolve  for  about  ten  minutes ;  or,  instead  of 
employing  a  cylinder  of  this  description,  the  pins  may  be  thrown  into  a  bag  or  bags 
partially  tilled  with  the  sawdust,  and  the  requisite  friction  produced  by  swinging  or 
rolling  these  bags  about  for  the  same  length  of  time. 

The  copper  coating  bath  or  mixture. — Into  a  glass  or  stone  vase,  tue  inventor  puts 
about  1^  gallons  of  soft  water,  seven -tenths  of  a  pound  of  sulphuric  acid,  six-one  hun- 
dredth lb.  of  salt  of  tin,  eight-one  hundredth  lb.  of  crystallized  sulphate  of  zinc,  and  108 
grs.  of  pure  sulphate  of  copper,  and  leaves  this  mixture  to  work  for  about  24  hours,  so 
that  the  salts  and  sulphates  may  be  properly  dissolved.  This  is  found  to  be,  on  the  whole, 
the  mixture  best  adapted  for  the  purpose  in  view ;  but  most  of  the  ingredients  mentioned 
may  have  others  substituted  for  them,  as,  for  example,  any  other  acid  or  substance  pro- 
ducing like  effects  ma}^  be  used  instead  of  the  sulphuric  acid,  or  the  sulphate  of  tin  may 
be  substituted  for  the  salt  of  tin. 

The  copper  coating  process. — ^The  mixture,  prepared  as  last  directed,  is  introduced  into 
another  revolving  cylinder,  and  pins  about  13^  lbs.  weight  are  thrown  into  the  midst  of 
it  The  cylinder  is  then  caused  to  revolve  for  about  half  an  hour,  which  serves  at  once 
to  remove  any  verdigris  from  the  pins  to  impart  a  high  polish  to  them,  and  to  give  a 
beginning  to  the  copper  coating  process.  At  the  end  of  the  half  hour  or  thereabouts 
232  grs.  of  crystallized  sulphate  of  copper  in  coarse  powder,  and  150  grs.  of  crystallized 
sulphate  of  zinc,  previously  dissolved  in  soft  water,  are  added  to  the  mixture  in  the 
cylinder,  and  the  whole  again  agitated  for  about  a  quarter  of  an  hour.  The  pins  are  by 
this  operation  not  only  completely  coated,  but  acquire  a  very  considerable  degree  of 
polish.  The  copper  liquors  being  drawn  off,  the  pins  are  washed  with  cold  water  in  the 
rotating  cylinder,  and  afterwards  in  a  tub  with  soap  and  water  out  of  contact  with  air, 
where  they  are  well  shaken.  The  contents  of  the  tub  are  then  emptied  into  a  wooden 
strainer,  having  a  perforated  bottom  of  tin  plate  iron.  The  pins  are  finally  dried  by 
agitation  with  dry  sawdust 

The  tinning  and  blanching  are  performed  by  laying  the  pins  upon  plates  of  very  thin 
tin  placed  one  above  another,  in  a  tinned  copper  boiler  containing  a  solution  of  about 
4  two-fifth  lbs.  of  crude  tartar  or  cream  of  tartar,  in  about  22  galls,  of  water,  and  then 
setting  the  whole  to  boil  for  about  12  hours.  The  tartar ,  solution  should  be  prepared 
at  least  24  hours  previously.  A  little  more  cream  of  tartar  improves  the  brilliancy  of 
the  pins. 

PIPKRINE  is  a  crystalline  principle  extracted  from  black  pepper  by  means  of  alcohol. 
It  is  colorless,  has  hardly  any  taste,  fuses  at  212°  F. ;  is  insoluble  in  water,  but  soluble 
in  acetic  acid,  ether,  and  most  readily  in  alcohol. 

PITCH,  MINERAL,  is  the  same  as  Bitumen  and  Asphalt. 

PITCH  of  vmd-tar  (Poix,  Fr.;  Pech,  Germ.)  is  obtained  by  boiling  tar  in  an  open 
iron  pot,  or  in  a  still,  till  the  volatile  matters  be  driven  off.  Pitch  contains  pyrolismeous 
resin,  along  with  colophany  (common  rosin),  but  its  principal  ingredient  is  the  former, 
called  by  Berzelius  pyretine.     It  is  brittle  in  the  cold,  but  softens  and  becomes  ducti  e 


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388 


PITCOAL. 


with  heat.  It  melts  in  boiling  water,  and  dissc:ve8  in  alcohol  and  oU.  of  turpentine,  at 
well  as  in  carbonated  or  caustic  alkaline  leys.  For  Pyretine,  see  the  mode  of  preparing 
it  from  birch  wood,  for  the  purpose  of  preparing  Russia  Leather. 

PITCOAL.  (HouilUj  Fr. ;  SUinkohky  Germ.)  This  is  by  far  the  most  valuable  of 
mineral  treasures,  and  the  one  which,  at  least  in  Great  Britain,  makes  all  the  others 
available  to  the  use  and  comfort  of  man.  Hence  it  has  been  searched  after  with  unre- 
mitting diligence,  and  worked  with  all  the  lights  of  science,  and  the  resources  of  art. 

The  Brora  coal-field  in  Sutherlandshire  is  the  most  remarkable  example  in  this,  or  in 
perhaps  any  country  hitherto  investigated,  of  a  pseudo  coal  basin  amon?  the  deeper 
secondary  strata,  but  above  the  new  sandstone  or  red  marl  formation.  The  Rev.  Dr. 
Buckland  and  Mr.  C.  Lyell,  after  visiting  it  in  1824,  had  expressed  an  opinion  that  the 
strata  there  were  wholly  unconnected  with  the  proper  coal  formation  below  the  new  red 
sandstone,  and  were  in  fact  the  equivalent  of  the  oolitic  series ;  an  opinion  fully  confirmed 
by  the  subsequent  researches  of  Mr.  Murchison.  {Geol.  Trans,  for  1827,  p.  293.)  The 
Brora  coal-field  forms  a  part  of  those  secondary  deposites  which  range  along  the  south- 
east coast  of  Sutherlandshire,  occupying  a  narrow  tract  of  about  twenty  miles  in  length, 
and  three  in  its  greatest  breadth. 

One  stratum  of  the  Brora  coal-pit  is  a  coal-shale,  composed  of  a  reed-like  striated 
plant  of  the  natural  order  Equiselum,  which  seems  to  have  contributed  largely 
towards  the  formation  of  that  variety  of  coal.  From  this  coal-shale,  tlie  next  transition 
upwards  is  into  a  purer  bituminous  substance  approachir<j  to  jet,  which  constitutes 
the  great  bed  of  coal.  This  is  from  3  feet  3  inches  to  3  feet  8  inches  thick,  and  is 
divided  nearly  in  the  middle  by  a  thin  layer  of  impure  indurated  shale  charged  with 
pyrites,  which,  if  not  carefully  excluded  from  llie  mass,  sometimes  occasions  sponta- 
neous combustion  upon  exposure  to  the  atmosphere;  and  so  much,  indeed,  is  that 
mineral  disseminated  throughout  the  district,  that  the  shales  might  be  generally  termed 
*^  pyritiferous."  Inattention  on  the  part  of  the  workmen,  in  1817,  in  leaving  a  large 
quantity  of  this  pyritous  matter  to  accumulate  in  the  pit,  occasioned  a  spontaneous 
combustion,  which  was  extinguished  only  by  excluding  the  air  ;  indeed,  the  coal-pit  was 
closed  in  and  remained  unworked  for  four  years.  The  fires  broke  out  again  in  the  nit 
in  1827.  .  «>  c  im 

The  purer  part  of  the  Brora  coal  resembles  common  pitcoal;  but  its  powder  has  the 
red  ferruginous  tinge  of  pulverized  lignites.  It  may  be  considered  one  of  the  last  links 
between  lignite  and  true  coal,  approaching  very  nearly  in  character  to  jet,  though  less 
tenacious  than  that  mineral ;  and,  when  burnt,  exhaling  but  slightly  the  vegetable  odor 
so  peculiar  to  all  imperfectly  bituminized  substances.  The  fossil  remains  of  shells  and 
plants  prove  the  Brora  coal  to  be  analogous  to  that  of  the  eastern  moorlands  of  York- 
shire, although  the  extraordinary  thickness  of  the  former,  compared  with  any  similar 
deposite  of  the  latter  (which  never  exceeds  from  12  to  17  inches),  might  have  formerly 
led  to  the  belief  that  it  was  a  detached  and  anomalous  deposite  of  true  coal,  rather  than  a 
lignite  of  any  of  the  formations  above  the  new  red  sandstone  :  such  misconception  might 
more  easily  arise  in  the  infancy  of  geology,  when  the  strata  were  not  identified  by  their 
fossil  organic  remains. 

On  the  coast  of  Yorkshire  the  strata  of  this  pseudo  coal  formation  appear  in  the  follow- 
ing  descending  order,  from  Filey  Bay  to  Whitby.  1.  Coral-rag.  2.  Calcareous  grit. 
3.  Shale,  with  fossils  of  the  Oxford  clay.  4.  Kelloway  rock  (swelling  out  into  an  impor- 
tant ar-naceous  formation).  5.  Cornbrash.  6.  Coaly  grit  of  Smith.  7.  Pierstone  (ac- 
cording to  Mr.  Smith,  t\ie  equivalent  of  the  great  oolite).  8.  Sandstone  and  shale,  with 
peculiar  plants  and  various  seams  of  coal.  9.  A  bed  with  fossils  of  the  inferior  oolite. 
10.  Mari-stone  ?  11.  Alum-shale  or  lias.  All  the  above  strata  are  identified  by  abundant 
organic  remains. 

In  the  oolitic  series,  therefore,  where  the  several  strata  are  developed  in  conformity 
with  the  more  ordinary  type  of  these  formations,  we  may  venture  to  predict  with 
certainty,  that  no  carboniferous  deposites  of  any  great  value  will  ever  be  discovered, 
at  all  events  in  Great  Britain.  A  want  of  such  knowledge  has  induced  many  persons 
to  make  trials  for  coal  in  beds  subordinate  to  the  English  oolites,  and  even  superior  to 
them,  m  places  where  the  type  of  formation  did  not  offer  the  least  warrant  for  such 
attempts.  . 

The  third  great  class  of  terrestrial  strata,  is  the  proper  coal-measures,  called 
the  carboniferous  rocks,  our  leading  object  here,  and  to  which  we  shall  presently 
return. 

The  transition  rocks  which  lie  beneath  the  coal-measures,  and  above  the  primi- 
tive rocks,  or  are  anterior  to  the  carboniferous  order,  and  posterior  to  the  primitive, 
contain  a  peculiar  kind  of  coal,  called  anthracite  or  stone-coal,  approaching  closely  in  its 
nature  to  carbon.  It  is  chiefly  in  the  transition  clay-slate  that  the  anthracite  occurs  in 
considerable  masses.  There  is  one  in  the  transition  slate  of  the  little  Saint  Bernard, 
near  the  village  of  la  Thuile  (in  the  Alps).    It  is  100  feet  long,  and  2  or  3  yards  thick. 


PITCOAL. 


389 


The  coal  bums  with  difficulty,  and  is  used  only  for  burning  lime.  There  are  seveml  of 
the  same  kind  in  that  country,  which  extend  down  the  reverse  slope  of  the  mountains 
looking  to  Savoy.  The  slate  enclosing  them  presents  vegetable  impressions  of  reeds  or 
analogous  plants.  To  the  transition  clay-slate  we  must  likewise  refer  the  beds  of  anthra- 
cite that  M.  Hericart  de  Thury  observed  at  very  great  heights  in  the  Alps  of  Dauphiny, 
in  a  formation  of  schist  and  gray-wacke  with  vegetable  impressions,  which  reposes  direct- 
ly on  the  primitive  rocks. 

The  great  carboniferous  formation  may  be  subdivided  into  four  orders  of  rocks :  1.  the 
coal-measures,  including  their  manifold  alternations  of  coal-beds,  sandstones,  and  shales ; 
2.  the  millstone  grit  and  shale  towards  the  bottom  of  the  coal  measures ;  3.  the  carbon- 
iferous limestone,  which  projecting  to  considerable  heights  above  the  outcrop  of  the  coal 
and  grit,  acquires  the  title  of  mountain  limestone ;  4.  the  old  red  sandstone,  or  connect- 
ing link  with  the  transition  and  primary  rock  basin  in  which  the  coal  system  lies. 

The  coal-fields  of  England,  from  geographical  position,  naturally  fall  under  the  follow- 
ing arrangement :—l.  The  great  northern  district;  including  all  the  coal-fields  north 
of  Trent.  2.  The  central  district ;  including  Leicester,  Warwick,  Stafford,  and  Shrop- 
shire. 3.  The  toestem  district ;  subdivided  into  north-western,  including  North  Wales, 
and  the  south-western,  including  South  Wales,  Gloucester,  and  Somersetshire. 

There  are  three  principal  coal-basins  in  Scotland:  1.  that  of  Ayrshire;  2.  that  ot 
Clydesdale ;  and  3.  that  of  the  valley  of  the  Forth,  which  runs  into  the  second  in  the 
line  of  the  Union  Canal.  If  two  lines  be  drawn,  one  from  Saint  Andrews  on  the  north- 
cast  coast,  to  Kilpatrick  on  the  Clyde,  and  another  from  Aberlady,  in  Haddingtohshire,  to 
a  point  a  few  miles  south  of  Kirkoswald  in  Ayrshire,  they  will  include  between  them 
the  whole  space  where  pitcoal  has  been  discovered  and  worked  in  Scotland. 

The  great  coal-series  consists  of  a  regular  alternation  of  mineral  strata  deposited  in  a 
great  concavity  or  basin,  the  sides  and  bottom  of  which  are  composed  of  transition  rocks. 
This  arrangement  will  be  clearly  understood  by  inspecting  fig.  1051  which  represents  a 
section  of  the  coal-field  south  of  Malmsbury. 


Mendip  hills. 


Dundry  hill. 


Wick  rocks. 


Fog  hill,  N.  of  Lansdownc 


1,  I,  old  red  sandstone;  2,  mountain  limestone;  3,  millstone  grit;  4,  4,  coal  seams; 
6,  Pennant,  or  coarse  sandstone ;  6,  new  red  sandstone,  or  red  marl ;  7,  7,  lias ;  8,  8,  in- 
ferior oolite ;  9,  great  oolite ;  10,  cornbrash  and  Forest  marble. 

No.  1,  or  the  old  red  sandstone,  may  therefore  be  regarded  as  the  characteristic  lining 
of  the  coal  basins ;  but  this  sandstone  rests  on  transition  limestone,  and  this  limestone  on 
gray-wacke.  This  methodical  distribution  of  the  carboniferous  series  is  well  exemplified 
in  the  coal-basin  of  the  Forest  of  Dean  in  the  south-west  of  England,  and  has  been  accu- 
rately described  by  Mr.  Mushet. 

The  gray-wacke  consists  of  highly  inclined  beds  of  slaty  micaceous  sandstone,  which  on 
the  one  hand  alternates  with  and  passes  into  a  coarse  breccia,  having  grains  as  large  as 
peas ;  on  the  other,  into  a  soft  argillaceous  slate.  The  gray-wacke  stands  bare  on  the 
north-eastern  border  of  the  Forest,  near  the  southern  extremity  of  the  chain  of  transition 
limestone,  which  extends  from  Stoke  Edith,  near  Hereford,  to  Flaxley  on  the  Severn.  It 
is  traversed  by  a  defile,  through  which  the  road  from  Gloucester  to  Ross  winds.  The 
abruptness  of  this  pass  gives  it  a  wild  and  mountainous  character,  and  affords  the  best  op 
portunity  of  examining  the  varieties  of  the  rock. 

The  Transition  limestone  consists  in  its  lower  beds  of  fine-grained,  tender,  exuemely 
argillaceous  slate,  known  in  the  district  by  the  name  of  water-stone,  in  consequence  of  the 
wet  soil  that  is  found  wherever  it  appears  at  the  surface.  Calcareous  matter  is  inter- 
spersed in  it  but  sparingly.  Its  upper  beds  consist  of  shale  altematinsr  with  extensive 
beds  of  stratified  limestone.  The  lowest  of  the  calcareous  strata  are  thin,  and  alternate 
with  shale.  On  these  repose  thicker  strata  of  more  compact  limestone,  often  of  a  dull 
blue  color.  The  beds  are  often  dolomitic,  which  is  indicated  by  straw  yellow  color,  or 
dark  pink  color,  and  by  the  sandy  or  glimmering  aspect  of  the  rock. 

The  old  red  sandstone,  whose  limits  are  so  restricted  m  other  parts  of  England,  here 


I 


390 


PITCOAL. 


PITCOAL. 


391 


if 


m 


; 


occupies  an  extensive  area.  The  space  which  it  covers,  its  great  thickness,  its  high  in- 
clmation  the  abrupt  character  of  the  surface  over  which  it  prevails,  and  the  consequent 
display  of  Its  strata  in  many  natural  sections,  present  in  this  district  advantages  for  studying 
the  formation,  which  are  not  to  be  met  with  elsewhere  in  South  Britain.  In  the  neigh- 
borhood of  Mitchel  Dean,  the  total  thickness  of  this  formation,  interposed  conformably 
between  the  transition  and  mountain  limestone,  is  from  600  to  800  fathoms.  The  old  red 
sandstone  is  characterized  in  its  upper  portion  by  the  presence  of  silicious  conglomerate, 
containing  sihcious  pebbles,  which  is  applied  extensively  to  the  fabrication  of  millstones 
near  Monmouth,  and  on  the  banks  of  the  Wye.  This  sandstone  encircles  the  Forest  with 
a  ring  of  very  elevated  ground,  whose  long  and  lofty  ridges  on  the  eastern  frontier  over- 
hang  the  valley  of  the  Severn. 

The  maujitain  limestone,  or  carboniferous,  is  distinguished  from  transitipn  limestone 
rather  by  its  position  than  by  any  very  wide  difference  in  its  general  character  or  organic 
remains.  According  to  the  measurements  of  Mr.  Mushet,  the  total  thickness  of  the 
mountain  limestone  is  about  120  fathoms.  The  zone  of  limestone  belonging  to  this 
coal-basin,  is  from  a  furlong  to  a  mile  in  breadth  on  the  surface  of  the  r-^und,  according 
as  the  dip  of  the  strata  is  more  or  less  rapid.  The  angle  of  dip  on  'th^  northern  and 
western  border  is  often  no  more  than  10°,  but  on  the  eastern  it  frequently  amounts  to 
80°.  The  calcareous  zone  that  defines  the  outer  circle  of  the  basin,  surfers  only  one 
short  interruption,  scarcely  three  miles  in  length,  where  in  consequence  of  a  fault  the 
limestone  disappears,  and  the  coal-measures  are  seen  in  contact  with  the  old  red 
sandstone. 

Coal  meawm.— Their  aggregate  thickness  amounts,  according  to  Mr.  Mushet,  to  about 
500  fathoms.     1.  The  lowest  beds,  which  repose  on  the  mountain  limestone,  are  about  40 
fathoms  thick,  and  consist  here,  as  in  the  Bristol  coal- basin,  of  a  red  silicious  grit  alter- 
nating with  conglomerate,  used  for  millstones ;  and  with  clay,  occasionally  used'fo/ochre 
2.  These  beds  are  succeeded  by  a  series  about  120  fathoms  thick,  in  which  a  gray  griti 
stone  predominates,  alternating  in  the  lower  part  with  shale,  and  containing  6  seams  of 
coal.     The  grits  are  of  a  fissile  character,  and  are  quarried  extensively  for  flag-stone 
ashlers^  and  fire-stone.    3.  A  bed  of  grit,  25  fathoms  thick,  quarried  for  hearth-stone' 
separates  the  preceding  series  from  the  followins,  or  the  4th,  which  is  about  115  fathoms 
thick,  and  consists  of  from  12  to  14   seams  of  coal  alternating  with  shale.     5.  To  this 
succeeds  a  straw-colored  sandstone,  nearly  100  fathoms  thick,  forming  a  high  xii^e  in  the 
interior  of  the  basin.     It  contains  several  thin  seams  of  coal,  from  6  to  \6  inches  In  thick- 
ness.    6.  On  this  reposes  a  series  of  about  12  fathoms  thick,  consisting  of  3  seams  of 
coal  alternating  with  shale.     7.  This  is  covered  with  alternate  beds  of  grit  and  shale 
whose  aggregate  thickness  is  about  100  fathoms,  occupying  a  tract  in  the  centre  of  the 
basin  about  4  miles  long,  and  2  miles  broad.    The  sandstone  No.  5  is  probably  the  equiva- 
lent of  the  Pennant  in  the  preceding  figure. 

The  floor,  or  pavement,  immediately  under  the  coal  beds  is,  almost  without  exception 
a  grayish  slate-clay,  which,  when  made  into  bricks,  strongly  resists  the  fire.     This  fire- 
clay varies  in  thickness  from  a  fraction  of  an  inch  to  several  fathoms.     Clay-ironstone  is 
often  disseminated  through  the  shale. 

The  most  complete  and  simplest  form  of  a  coal-field  is  the  entire  basin-shape  which 
we  find  in  some  instances  without  a  dislocation.  A  beautiful  example  of  this  is  to  be  seen 
at  Blairengone,  in  the  county  of  Perth,  immediately  adjoining  the  western  boundary  of 
Clackmannanshire,  as  represented  in  fig.  1052,  where  the  outer  elliptical  lino,  marked 


1055 


East  B I    l"*^ 


A  West 


EastB 


A  Weal 


1056 


1067 


A,  B,  c,  D,  represents  the  crop,  outburst,  or  basset  edge  of  the  lower  coal,  and  the  inner 
elliptical  Une  represents  the  crop  or  basset  edge  of  the  superior  coal.    f»g.l053is  the 


.ongitudinal  section  of  the  line  A  b  ;  and  yig.  1054  the  transverse  section  of  the  line  c  d 
AJl  the  accompanying  coal  strata  partake  of  the  same  form  and  parallelism.  These 
basins  are  generally  elliptical,  sometimes  nearly  circular,  but  are  often  very  eccentric, 
being  much  greater  in  length  than  in  breadth  ;  and  frequently  one  side  of  the  basin  on 
the  short  diameter  has  a  much  greater  dip  than  the  other,  which  circumstance  throws 
the  trough  or  lower  part  of  the  basin  concavity  much  nearer  to  the  one  side  than  to  the 
other.  From  this  view  of  one  entire  basin,  it  is  evident  that  the  dip  of  the  coal  strata 
belonging  to  it  runs  in  opposite  directions,  on  the  opposite  sides,  and  that  all  the  strata 
regularly  crop  out,  and  meet  the  alluvial  cover  in  every  point  of  the  circumferential  space, 
like  the  edges  of  a  nest  of  common  basins.     The  waving  line  marks  the  river  Devon. 

It  is  from  this  basin  shape  that  all  the  other  coal-fields  are  formed,  which  are  segments 
of  a  basin  produced  by  slips,  dikes,  or  dislocations  of  the  strata.  If  the  coals  (%.  1062) 
were  dislocated  by  two  slips  6  c  and  d  e,  the  slip  6  c  throwing  the  strata  down  to  the  east, 
and  the  slip  d  e  throwing  them  as  much  up  in  the  same  direction,  the  outcrops  of  the  coals 
would  be  found  in  the  form  represented  in  Jig,  1065  of  which^g.l056LS  the  section  in  the 
line  A  B,  and  yig.  800  the  section  in  the  line  c  d. 

The  chief  difficulty  in  exploring  a  country  in  search  of  coal,  or  one  where  coal-fields 
are  known  to  exist,  arises  from  the  great  thickness  of  alluvial  and  other  cover,  which 
completely  hides  the  outcrop  or  basset  edge  of  the  strata,  called  by  miners  the  rock-head  ; 
as  also  the  fissures,  dikes,  and  dislocations  of  the  strata,  which  so  entirely  change  the 
structure  and  bearings  of  coal-fields,  and  cause  often  great  loss  to  the  mining  adventurer. 
The  alluvial  cover  on  the  other  hand  is  beneficial,  by  protecting  the  seams  of  the  strata 
from  the  superficial  waters  and  rains,  which  would  be  apt  to  drown  them,  if  they  were 
naked.     In  all  these  figures  of  coal-basins,  the  letter  a  indicates  coal. 

The  absolute  shape  of  the  coal-fields  in  Great  Britain  has  been  ascertained  with  sur- 
prising precision.  To  whatever  depth  a  coal-mine  is  drained  of  its  water,  from  that 
depth  it  is  worked,  up  to  the  rise  of  the  water-level  line,  and  each  miner  continues  to  ad- 
vance his  room  or  working-place,  till  his  seam  of  coal  meets  the  alluvial  cover  of  the 
outcrop,  or  is  cut  off  by  a  dislocation  of  the  strata.  In  this  way  the  miner  travels  in  s«c- 
cession  over  every  point  of  his  field,  and  can  portray  its  basin-shape  most  minutely, 
l^'tg.  1058  represents  a  horizontal  plan  of  the  Clackmannanshire  coal-field,  as  if  the 
1058  strata  at   the  outcrop  all  around  were  denuded 

c:^^i'y£2  of  the  alluvial  cover.  Only  two  of  the  con- 
centric beds,  or  of  their  edges  a,  a,  are  repre 
sented,  to  avoid  perplexity.  It  is  to  be  re- 
membered, however,  that  all  the  series  of  at- 
tendant strata  lie  parallel  to  the  above  lines. 
This  plan  shows  the  Ochill  mountains,  with 
the  north  coal-fields,  of  an  oblong  elliptical  shape, 
jWestthe  side  of  the  basin  next  the  mountains  being 
precipitous,  as  if  upheaved  by  the  eruptive 
^'•**  ^^'-^^  S^ ^^""^^^''^N, slip. trap-rocks;    while 


JKifefefe^^;-^?^?; 


west 
distance 


edges 


of  the 
from  the 


the  south,  the  east,  and  the 
basin  shelve  out  at  a  great 
lower  part  of  the  concavity 
or  trough,  as  miners  call  it.  Thus  the  alternate 
beds  of  coal,  shale,  and  sandstone,  all  nearly 
concentric  in  the  north  coal-field,  dip  inwards 
from  all  sides  towards  the  central  area  of  the 
trough.  The  middle  coal-field  of  this  district, 
however,  which  is  formed  by  the  great  north 
slip,  is  merely  the  segment  of  an  elliptical  basin, 
where  the  strata  dip  in  every  direction  to  the  middle  of  the  axis  marked  with  the  letter  x ; 
being  the  deepest  part  of  the  segment.  The  south  coal-field,  formed  by  the  great  south 
slip,  is  likewise  the  segment  of  another  elliptical  basin,  similar  in  all  respects  to  the  mid- 
dle coal-field.  Beyond  the  outcrop  of  the  coals  and  subordinate  strata  of  the  south  coal- 
fields, the  counter  dip  of  the  strata  takes  place,  producing  the  mantle-shaped  form  ;  whence 
the  coal  strata  in  the  Dunmore  field,  in  Stirlingshire,  lie  in  a  direction  contrary  to  those 
of  the  south  coal-field  of  Clackmannanshire,     o,  are  the  Ochill  mountains. 

Fig.  1059  is  intended  to  represent  an  extensive  district  of  country,  containing  a  great 
coal-basin,  divided  into  numerous  subordinate  coal-fields  by  these  dislocations.  The  lines 
marked  6  are  slips,  or  faults  ;  the  broad  lines  marked  c  denote  dikes  ;  the  former  dislocate 
the  strata,  and  change  their  level,  while  dikes  disjoin  the  strata  with  a  wall,  but  do  not 
in  general  affect  their  elevation.  The  two  parallel  lines  marked  a,  represent  two  seams 
of  coal,  variously  heaved  up  and  down  by  the  faults ;  whereas  the  dikes  are  seen  to  pass 
through  the  strata  without  altering  their  relative  position.  In  this  manner,  partial  coal- 
ields  are  distributed  over  a  wide  area  of  country,  in  every  direction. 
The  only  exception  to  this  general  form  of  the  coal-fidds  in  Great  Britain,  is  the  in- 


392 


PITCOAL. 


but  a  partial  occurrence,  or  a  deviat[nn   J^  ^^^^^f  »^?  ^oal-fields,  this  convex  form  U, 

^  -^^  hill,    close     to    the     town    of    Dudley. 

i,  1,  are  Lmestone  strata;  2,  2,  are  cool. 
Through    this    hill,    canals    have    been 
cut,  Jor  working  the  immense  beds  of 
carboniferous    limestone.      These    occui 
in    the    lower    series  of  the    strata  of 
the   coal-field,   and    therefore    at  a   dis- 
tance  of  many  miles  from  the  Castle- 
hill,    beyond    the     outcrop    of    all    the 
workable    coals    in    the     prqper    basin- 
shaped   part  of  the  field;    but    by  this 
apparently     inverted     basin-form,     these 
imestone  beds    are  elevated   far    above 
the  level  of  the  general  surface  of  the 
country,    and     consequer  Jy    above     the 
eyel  of  all  the  coals.     We  must  regard 
this  seeming  inversion  as  resulting  from 
the  approximation  of  two  coal-basins,  sep- 
arated by  the  basset  edges  of  their  moun- 
tain jimestone  repository. 

Fig.  1061  is  a  vertical   section  of  the 
Dudley    c(»l-basin,    the    nppcr    coal-bed 

nr  on  r      ^^^  }^^  astonishing  thickness 

01  SO  feet ;  and  this  mass  extends  7  miles 

in  length,  and  4  in  breadth.     Coal-seams 

a  or  6  feet  thick,  are  called  Miw  in  that 

district. 

1^1^.1062  18  a  very  interesting  section 

of  the    mam    coal-basin  of  Clackman- 

nanshire,  as  given   by   Mr.  Bald   in  the 

^  Wernerian    Society's    Memoirs,  vol.  iii. 

ordinate  coal-fields,  formed    by  two  ereat^lluul^  n7%T  '!•  ^'""^^J"  i"*°  ^^'^^  ^"^ 
independently  of  these  fractures   arrrS/tL      J  ,        ^»5^°«^tion8  of  the  strata;    but 

which  dislocates  the  coal  and  the  narallpl  -^trui  Jtr!*l  'P*» 

of  I9*?n  f^^i  K«  ™k-  u     11   1^        Pa'aiiei  strata  to  the  enormous  extent 

and  coal-field  resume  their  course  and  H:„  ™  i   ?         f '  ""*  '"■■» 
ning  through  a  longer  range  than  ^rher  oMh?„",^''^/"'''''*;^^  """- 

miners.  coal-seams  thus  upheaved,  are  called  edge-metals  by  the 

1062  ' 


PITCOAL. 


39a 


In  this  remarkable  coal-field,  which  has  been  accurately  explored  by  pitting  and 
boring  to  the  depth  of  703  feet,  there  are  no  fewer  than  142  beds,  or  distinct  strata  ol 
coal  shale,  and  sandstone,  &c.,  variously  alternating,  an  idea  of  which  may  be  had 
1063       bv  inspecting  jig-  1063    Among  these  are  24  beds  of  coal,  which  would  con- 
sl'iiute  an  aggregate  thickness  of  59  feet  4  inches ;  the  thinnest  seam  ol  coal 
being  2  inches,  and  the  thickest  9  feet.     The  strata  of  this  section  contain 
numerous  varieties  of  sandstone,  slate-cay,  bituminous  shale,  indurated  clay,  or 
fire-clay,  and  clay  ironstone.     Neither  trap-rock  nor  limestone  is  found  in  con- 
nexion with  the  workable  coals ;  but  an  immense  bed  of  greenstone,  named 
Abbey  Craig,  occurs  in  the  western  boundary  of  Clackmannanshire,  under  which 
lie  regular  strata  of  slate-clay,  sandstone,  thin  beds  of  limestone,  and  large  sphe- 
roidal masses  of  clay  ironstone,  with  a  mixture  of  lime. 

«  With  regard  to  slips  in  coal-fields,"  says  Mr.  Bald,  «  we  find  that  there  is  a 
general  law ''connected  with  them  as  to  the  position  of  the  dislocated  strata, 
which  is  this :— W^hen  a  slip  is  met  with  in  the  course  of  working  the  mines — 
if  when  looking  to  it,  the  vertical  line  of  the  slip  or  fissure,  it  forms  an  acute  angle 
with  the  line  of  the  pavement  upon  which  the  observer  stands,  we  are  certain 
that  the  strata  are  dislocated  downwards  upon  the  other  side  of  the  fissure.   On 
the  contrary,  if  the  angle  formed  by  the  two  lines  above  mentioned  is  obtuse,  we 
are  certain 'that  the  strata  are  dislocated  or  thrown  upwards  upon  the  other  side 
of  the  fissure.     When  the  angle  is  90%  or  a  right  angle,  it  is  altogether  uncertain 
whether  the  dislocation  throws  up  or  down  on  the  opposite  side  of  the  slip. 
When   dikes  intercept  the  strata,  the^    generally  only  separate  the  strata  the 
width  of  the  dike,  without  any  dislocation,  either  up  or  down  ;  so  that  if  a  coal 
is  intercepted  by  a  dike,  it  is  found  again  by  running  a  mine  directly  forward, 
corresponding  to  the  angle  or  inclination  of  the  coal  with  the  horizon.  — 
Wernerian  Society's  Memoirs,  vol.  iii.  p.  133.* 

The  Johnstone  coal-field,  in  Renfrewshire,  is  both  singular  and  interesting. 
The  upper  stratum  of  rock  is  a  mass  of  compact  greenstone  or  trap,  above  100 
feet  in  thickness,  not  at  all  in  a  conformable  position  with  the  coal  strata,  but 
overlying;  next  there  are  a  few  fathoms  of  soft  sandstone  and  slate-clay,  alter- 
nating, and  uncommonly  soft  Beneath  these  beds,  there  are  no  fewer  than  ten 
seam^  of  coal,  lying  on  each  other,  with  a  few  divisions  of  dark  indurated  clay. 
These  coal-seams  have  an  aggregate  thickness  of  no  less  than  100  feet ;  a  mass  of 
combustible  matter,  in  the  form  of  coal,  unparalleled  for  its  accumulation  in  so 
narrow  a  space.  The  greater  part  of  this  field  contains  only  5  beds  of  coal ;  but 
at  the  place  where  the  section  shown  in^g.l064i8taken,  these  five  coals  seem  to 
have  been  overlapped  or  made  to  slide  over  each  other  by  violence.  1  his  struc- 
ture is  represented  in  fig- 1065  which  is  a  section  of  the  Quarrellon  coal  m  he 
Johnstone  field,  showing  the  overlapped  coal  and  the  double  coal,  with  the  thick 
bed  of  greenstone,  overlying  the  coal-field. 

1065 


a.  Alluvial  cover.  «•  Position  of  greenstone,  not  ascertained. 

6.'  Bed  of  trap  or  greenstone.  /.  Strata  in  which  no  coals  have  been  found. 

/  Alternating  coal  strata.  g.  The  overlapped  coal. 

d.  Coal-seams.  h.  The  double  coal. 

Before  proceeding  to  examine  the  modes  of  working  coal,  I  shall  introduce  here  a  de- 
scription of  the  two  principal  species  of  this  mineral. 

1.  Cubical  coal.— li  is  black,  shining,  compact,  moderately  hard,  but  easily  frangible. 
When  extracted  in  the  mine,  it  comes  out  in  rectangular  masses,  of  which  the  smaller 
frac'ments  are  cubical.  The  lamellae  (reed  of  the  coal)  are  always  parallel  to  the  bed  or 
plane  on  which  the  coal  rests  ;  a  fact  which  holds  generally  with  this  substance.  There 
are  two  varieties  of  cubical  coal ;  the  open-biimivg  and  the  caking.  The  latter,  however 
small  iis  fragments  may  be,  is  quite  available  for  fuel,  in  consequence  of  its  agglutinating 
into  a  mass  at  a  moderate  heat,  by  the  abundance  of  its  bitumen.  This  kind  is  the  true 
smithy  or  forge-coal,  because  it  readily  forms  itself  into  a  vault  round  the  blast  of  the 
bellows,  which  serves  for  a  cupola  in  concentrating  the  heat  on  objects  thrust  into  the 

The  open-burning  cubical  coals  are  known  by  several  local  names;  the  rough  coal  or 
♦  Thi«  paper  does  honor  to  its  author,  the  eminent  coal-viewer  of  Scotland. 

Vol.  II.  3  E 


>' 


r< 


iiHil 


394 


PITCOAL. 


Siil^I?.'^!!?^  ""  '°i^  ?TVu  "  ""'"'  "'«''  ■"»''  •»  •'"'J  ""d  the  cherry  coal,  from 
«  ■.iHri^  w    ""^,'""'=^.  >■«?  spontaneously  burn  ;  whereas  the  caking  coals  such 

"c  gravity  taSrlX^'",*?'  "'""'^  •"  ""  '"'^'""''"'^  '»''"'  -  "'^  5""-    "^  W 

*t^;u1[rfJ„^^r.C^i;\t^^^^^^^^^^ 

resists  the  cross  fracture,  which  is  conchoidal.  S|«cific  |rav  y  from  h26  to'^-40  ij 
cltn'^'^rl^^tl  Z  '"S«,1"=>''i;'"'Sular  sharp-edgi  masses  It  Zfns  tilhou" 
caKmg,  produces  much  flame  and  smoke,  unless  judiciously  supplied  with  air  and  leaves 

£?2e"'."  Ls  rft  mLke"  '"'"  •"■  f  "^  "f  r-    "  ''  '"«  best'fllell;  dSr  es  and  al 
large  grates,  as  it  makes  an  open  fire,  and  does  not  clog  up  the  bars  with  »la«v  scoria 

LSofla^bon'  70-9  "il^"  """T?  ^'''  '"  ""^  ^'^'^'  gravi7y'of°l^^,3^ 
consist  01 — carbon,  70-9  ;  hydrogen,  4'3  ;  oxygen,  24-8. 

3.  Camiel  coal.— Color  between  velvet  and  grayish-black :  lustre  rcMnous-  fracture 
even;  fragments  trapezoidal ;  hard  as  splint  coal ;  spec.  grav;i.2^To  As  Tn\vo^^^^^^ 
It  IS  detac  ed  m  four-sided  columnar  masses,  oftei  b'reaks  coichoidll,  lile  pit^knilS 
wh^nc'ftfname     rn"^''  "  'J^^k'  white  projective  flame,  like  thi  wick'of  a'  Sle 

^  a  bed  4  feerthiJ  Tn^V  "'''•'  ^^"^^^f^^  V^^  "^^^'^^'^  °^  ^igan,  in  Lancashire 
in  a  bed  4  teet  thick ;  and  there  is  a  good  deal  of  it  in  the  Clydesdale  wal-field  of  which 

Lrdirsoil'  hrfiLT"  ''.h'  "  r'^'-  ''  ^^^^^^^^  -^^  '^"^^  du^t "n  the  mLTanS 
hardly  soil^  the  fingers  wuh  carbonaceous  matter.     Cannel  coal  from  Woodhall  near 

nrTJ^^'hf'nt  ^'^Z'  ^'^^'  "«"^^^^^  ^>'  "^^  ^»^^>«i«  of-carbon,  72-22?  hyZ^en  3^3 

S  in  the  ScoT^L'  "  '"''  r^'  ^'"^"^  ?•?  '"^  ''^  ^''^'^  This  coal'has  beek  ?ound  ti 
anord,  m  the  Scotch  gas-works,  a  very  rich-burning  gas.     The  azote  is  there  converted 

'4  'Gw'Lf'Th'  '  considerable  quantity  is  disUlled  over  inL  th^  tar-pTt  '"^ 

likt^farof  temne7J.;L'rr't  ^''  ^"  ^'""-.^^^^^  ^"^«'''  ^'^^  ^"  occasional  iridiscence, 
liKe  that  ot  tempered  sleel;  lustre  in  general  splendent,  shining,  and  imierfect  metallic- 
does  not  soil ;  easily  frangible  ;  fracture  flat  conchoidal ;  fra<^meSts  sha r^edoS      It  burns 

s^  I  pScTsriT'^d  "'^"^^-  7  -^p*^---;  a'nTri:trafhite.ts 

asa.  It  produces  no  soot,  and  seems,  indeed,  to  be  merely  carbon  or  coal  denrived  of 
iuVnt  J^^m  ^on^'acTwTw^"^  and  converted  into  coke  by  L^errakean^clS  o^^^^^^^^^ 
quenl  >  Horn  contact  with  whm-dikes.     Glance  coal  abounds  in  Ireland  under  the  name 

lo^e'^a^r^ale^'^tt'tt  "  l'^'"''  '^'"'^  '^^^^^  ^^^^  "^  bur^fwithout  flame  or 
smoKe     ana  in  Wales,  it  is  the  malting  or  stone  coal.     It  contains  from  90  to  97  ner  cent 

puruLs"-       '""'''"  ''''''''  ^''"^  '-'  ''  '-' '  ^"^--^"^  ^'^'^  '^-  prop^rtl  of  Sy  iS!: 

«,  dffficulf  fnf  tti^mi^lT^iT  ^'"'^^  ^'\^«-l-fields,  which  render  the  search  for  coal 
?    nik^h      o    c/  •  S"  ?  laborious  and  uncertain,  are  the  following  :— 

^y.^    l\u  ^'  ?'r  ?r  ^«"^'^-     3.  Hitches.     4.  Troubles,  ^ 

The  first  three  infer  dislocation  of  the  strata ;  the  fourth  changes  in  the  bed  of  coal  itself 

Les  extenYnrLt'^'^^'^T^  ""^^f'  "'^^'^  ''^'^'^  -"  '^'  ^e^sLTcolv^t"^' 
run  soLtimL  in  diffprLT  r  ^^^  «^  ^^^ji"?  through  coal-fields  for  many  miles,  but 

eTe^^rsr^^Tch'th"  '  ^i?f  10^  ''  ^  ^^^^  '"'"'  ^""-^^"^  in  various  d^rS^^^^^^^ 
even  crossu^  each  other.     Fig.  1066  represents  a  ground  plan  of  ^  coal-field,  intersected 

H  F  ""       ~ 


With  greenstone  dikes.  A  b  and  c  fc 
are  two  dikes  standing  parallel  to  each 
other ;  E  F  and  G  H  are  cross  or  oblique 
dikes,  which  divide  both  the  coal  strata 
and  the  primary  dikes  a  b  and  c  d. 

2.  Slips  or  faults  run  in  straight  lines 

through    coal-measures,    and    at    every 

angle    of    incidence     to     each     other. 

Fig.  1067  represents  a  ground   plan  of 

a  coal-field,  with  two  slips  a  b  and  c  d 

in  the  line  of  bearing  of  the  planes  of 

the  strata,  which   throw  them  down   to 

A  the  outcrop.     This  is  the  simplest  form 

^  of  a   slip.    Fig.  1068  exhibits  part  of  a 

^  coal-field   intersected   with   slips,  like  a 

cracked  sheet  of  ice.      Here  a  b  is  a 

J .     dike;     while    the    narrow    lines    show 

:rrs^v:  t^.  i^it  ?  ^-  ^  ^.^  i»^"tee  a 

Ji/cAel  '    '  '      "*  '^^  ^'""^^  ^* ""  ^^^«t^  ^°"^  smaU  partial  slips  called 


PITCOAL. 


395 


The  effects  of  slips  and  dikes  on  the  coal  strata  appear  more  prominently  wheti 

viewed  in  a  vertical  section,  than  in  a  ground  plan,  where  they  seem  to  be  merely  waUs, 

veins,  and  lines  of  demarcation.    Fig.  1069  is  a  vertical  section  of  a  coal-field,  from  dip 

crop.        1068  AC 


1069 


rise  F      D  B  dip. 

to  rise,  showing  three  strata  of  coal  a,  6,  c.  a  b  represents  a  dike  at  right  angles  to  thfc 
plane  of  the  coal-beds.  This  rectangular  wall  merely  separates  the  coal-measures, 
affecting  their  line  of  rise ;  but  further  to  the  rise,  the  oblique  dike  c  d  interrupts  the 
coals  a,  /»,  c,  and  not  only  disjoins  them,  but  thro\rs  them  and  their  concomitant  strata 
greatly  lower  down ;  but  still,  with  this  depression,  the  strata  retain  their  parallelism 
and  general  slope.  Nearer  to  the  outcrop,  another  dike  e,  f,  interrupts  the  coals  a,  6,  c, 
not  merely  breaking  the  continuity  of  the  planes,  but  throwing  them  moderately  up,  so 
as  to  produce  a  steeper  inclination,  as  shown  in  the  figure.  It  sometimes  happens  that 
the  coals  in  the  compartment  h,  betwixt  the  dikes  c  and  e,  may  lie  nearly  horizontal, 
and  the  effect  of  the  dike  e,  f,  is  then  to  throw  out  the  coals  altogether,  leaving  no 
vestige  of  them  in  the  compartment  k.  "Such,"  says  Mr.  Bald,  from  whom  these 
illustrations  are  borrowed,  «  are  the  most  prominent  changes  in  the  strata,  as  to  their 
line  of  direction,  produced  by  dikes ;  but  of  these  changes  there  are  various  modifica- 
tions." 

The  effect  of  slips  on  the  strata  is  also  represented  in  the  vertical  section,  /g.  1070  where 
a,  6,  c  are  coals  with  their  associated  strata.    A,  b,  is  an  intersecting  slip,  which  throws  all 

1070  the  coals  of  the  first  com- 

partment much  lower,  as  is 
observable  in  the  second, 
No.  2 ;  and  from  the  amount 
of  the  slip,  it  brings  in  other 
coal-seams,  marked  1,  2,  3, 
not  in  the  compartment 
No.  1.  c,  D,  is  a  slip  pro- 
ducing a  similar  result,  bul 
not  of  the  same  magnitude. 
E,  F  represents  a  slip  across 
Y   D  ^  the  strata,  reverse  in  direc- 

the  former  ;  the  effect  of  which  is  to  throw  up  the  coals,  as  shown  in  the  area 
Such  a  slip  occasionally  brings  into  play  seams  seated  under  those  marked  a,  h,  c, 


.••y.,>-'<\»>-^,,,,^f,. 


tiUUH 


tlon  to 
No.  4. 


1071 


l^yf""tfU(Cf^t*"'  ""'TMllif'" 


I ■ LM-ariiiiiiMi 


as  seen  at  4,  5,  6 ;  and  it  may  happen 
that  the  coal  marked  4  lies  in  the  pro- 
longation of  a  well-known  seam,  as  c, 
in  the  compartment  No.  3,  when  the 
case  becomes  puzzling  to  the  miner. 
In  addition  to  the  above  varieties,  a 
number  of  slips  or  hitches  are  often  seen 
near  one  another,  as  in  the  area  marked 
No.  5,  where  the  individual  displace- 
ments are  inconsiderable,  but  the  ag- 
gregate dislocation  may  be  great,  in 
reference  to  the  seams  of  the  6th  compart- 
ment. 

The  results  of  dikes  and  slips  on  a  hori- 
zontal portion  of  a  field  are  exemplified  in 
fig.  1071.  Where  the  coal-measures  are 
horizontal,  and  the  faults  run  at  a  greater 
angle  than  45°  to  the  line  of  bearing,  they 
are  termed  dip  and  rise  faults,  as  a  b,  c  d, 

E  F. 

Coal-viewers  or  engineers  regard  the 
dislocations  now  described  as  being  sub- 


ject  in  one  respect  to  a  general  law,  which  may  be  thus  explained : — Let  fig.  1072 


396 


PITCOAL. 


PITCOAL. 


397 


f 


be  a  portion  of  a  coal-measure ;  a,  being  the  pavement  and  b  the  roof  of  the  coal-seam 
If,  m  pursuing  the  stratum  at  c,  a  dike  d  occurs,  standing  at  rH^t  ancles  wth  X' 
pavement  they  conclude  that  the  dike  is  merely  a  Wut'otwaU  teVwee^^^^^^^^^ 
its  own  thickness,  leaving  the  coal-seam  underanged  on  either  side    but  if  a  dike  . 
forms,  as  at  e,  an  obtuse  angle  with  the  pavement,^hey  conclude  that'  the  d  ke  is  not  a 
simple  partition  between  the  strata,  but  has  thrown  up  the  several  seams  into  he  nrP 
dicament  shown  at  g      Finally,  should  a  dike  h  make  at  i  aTacuteTngleUth  t^^^^^ 
Srof  K.''  ""''"''  '"^^  '"'  "^^  '^^  '^^^^"'^  ^^-'^  the"cormeasu?esTnlo  tt 
The  same  important  law  holds  with  slips,  as  I  formerly  stated ;  only  when  thev  form 

Dikes  and  faults  are  denominated  upthrow  or  downthrow  accordin«r  tn  th»  ,./.«:.:^« 

djke  hkew.se  towards  the  rise.  Oa  the  other  hand,  when  theX«  are X  wUh  by  Z 
miner  m  working  from  the  rise  to  the  dip,  the  names  of  the  above  dikes  would  ™e  reveLid* 

c«;e7the''thrckT.«I;?',hf  *''.'"■*  """"  and  partial  dips,  where  the  dislocation  does  not 
S»„  ^  m-,'^'  °^  ""*  '=»,a'-s<«m ;  and  they  are  correctly  enough  called  Uev,  bv  the 
Buner.    f  .g.  I073represen^ts  rte  operaUon  of  the  kitcKe,  a,  b,*;,  d,  i,  r^X  onThe  LIS! 

measures.  Though  observed  in 
one  or  two  seams  of  a  field,  they 
may  not  appear  in  the  rest,  as  is 
the  case  with  dikes  and  faults. 

4.  Troubles  in  coal-fields  are  of 
various  kinds. 

1.  Irregular  layers  of  saneU 
stoftie,  appearing  in  the  middle  of 
the  coal-seam,  and  gradually 
increasing  in  thickness  till  they 
separate  the  coal  into  two  dis- 
tinct seams,  too  thin  to  continue 
workable. 

2.    Nipsy  occasioned    by    the 
"^radual  approximation  of  the  roof 


1073 


and  pavemeHOanSt  a  vestige  of  coal  is  left  between  th;m  rTheTorr  shj  diskppe':? 

S^mre."'.LT.Vr'-      '''>•.•  1"*""''  ^^U  represent  this  accMent,  wWch 'SK 
5  'ir^J  '  ">=fifst  being  a  vertical,  and  the  second  a  horizontal  view. 

,  Ji  J    ?     • "!}     •  J'  '«,™''"«s  «>e  ™l>t>ish  of  an  old  waste,  being  a  confused  heap  of 

^tLtheCde     ™,T'  i"'"''^'"'  '=",'"^="  •=•«"•  ^  ^°"  "'^'  '•  «»"  frequenlly  te'dS^ 
with  the  spade.    This  shattering  is  analogous  to  that  observed  occasionally  in  the  flint 

noduks  of  the  chalk  formation,  and  seems  like  the  eifect  of  some  electric  tremor  of  thi 

J^J^?:?}^^  '"J' "??'  '"  "">'  tonntry,  its  concomitant  rocks  ought  to  be  looked  for 
Ur?rGi^lot°o^?5T/  °'  """•"!?'"  limestone,  known  by  its'organic  fosTib ,  (s« 
millstone  ir?r','„dlhl„  ""•«'l»"<l'ng  plate  of  fossils;)  likewise  the  outcrop  if  the 
«„™i  I^r  *  i'  *"\"'?.  "^'^CT  red  sandstone,  among  some  rifts  or  facades  of  which 

pS  "'"'  "'  ''""™'^-    ^"'  "»  "^^""""^  of  «»'  -»  »•«  had  wfth?ut  LTng  0^ 

.dv™?u"e,'' wllo  ^,t'o™?.%  distinguishes  the  genuine  miner  from  the  empirical 
.„n       '    .    '  '5"°™n'  of  llie  general  structure  of  coal-basins,  expends  labor  tinuT 

r«dinTh1semproy«°Jis?nk",'".'"X  'V  """^V  '"'^^'""  'heV^^r  coal &,'rd 
vfewer  therefore  should  .Tl  f-  T''"^""  P-^oductive  seams  can  be  had.  A  skilful 
countiJf .  '  "'"  '•'"'='  **  *"""'  operations,  especially  in  an  unexplored 

are^'atout  an  M  llT^„^^'  "^  ""=  ^'  """*  ■»»^'  «*-«>«!<»»  S'^'dish  iron ,  in 
?n  a  mX  «rew  a?  one  end.l"  T"^-  ^^"^  "^  '^  "^"""y  ^  feet  long,  lermina  ing 
eommll    Ts'IclTn;  "lUlro'm'TtchTaL^'a't?^^  ^^  boring  chisel,  a4 

may  be  screwed,  as  occasion  requires,  to  the  brace-head/to  Lke  Te  heVabive  ihS 


mouth  of  the  bore  convenient  for  the  hands  of  the  men  in  working  the  rods.  Henca 
the  series  of  rods  becomes  a  scale  of  measurement  for  noting  the  depth  of  the  bore,  and 
keeping  a  journal  of  the  strata  that  are  perforated.  The  brace-head  rod,  also  18  inches 
long,  has  two  large  eyes  or  rings  at  its  top,  set  at  right  angles  to  each  other,  through 
whFch  arms  of  wood  are  fixed  for  the  men  to  lift  and  turn  the  rods  by,  in  the  bormg 

process. 

When  the  bore  is  intended  to  penetrate  but  a  few  fathoms,  the  whole  work  may  be  per- 
formed directly  by  the  hands ;  but  when  the  bore  is  to  be  of  considerable  depth,  a  lofty 
triangle  of  wood  is  set  above  the  bore  hole,  with  a  pulley  depending  at  its  summit  angle, 
for  conducting  the  rope  to  the  barrel  of  a  windlass  or  wheel  and  axle,  secured  to  the  ground 
with  heavy  stones.  The  loose  end  of  the  rope  is  connected  to  the  rods  by  an  oval  iron 
ring,  called  a  runner ;  and  by  this  mechanism  they  may  be  raised  and  let  fall  in  the 
boring ;  or  the  same  effect  may  be  more  simply  produced  by  substituting  for  the  wheel 
and  axle,  a  number  of  ropes  attached  to  the  rod  rope,  each  of  which  may  be  pulled  by  a 
man,  as  in  raising  the  ram  of  the  pile  engine. 

In  the  Newcastle  coal  district  there  are  professional  master-borers,  who  undertake  to 
search  for  coal,  and  furnish  an  accurate  register  of  the  strata  perforated.  The  average 
price  of  boring  in  England  or  Scotland,  where  no  uncommon  difficulties  occur,  is  six 
shillings  for  each  of  the  first  five  fathoms,  twice  6  shillings  for  each  of  the  second  five 
fathoms,  thrice  6  shillings  for  each  of  the  third  five  fathoms,  and  so  on ;  hence  the  series 
will  be — 

1st  five  fathoms       .        -        -        - 
2d    five  fathoms   -        -        -        - 
3d    five  fathoms       -        -        -        - 
4th  five  fathoms  -        -        -        - 

20  fathoms  of  bore         -        -        - 


£15  0 


Thus  the  price  increases  equably  with  the  depth  and  labor  of  the  bore,  and  the  under- 
taker usually  upholds  his  rods.  There  are  peculiar  cases,  however,  in  which  the  expense 
greatly  exceeds  the  above  rate. 

The  boring  tools  are  represented  in  the  following  figures : — 

1076 

16       ..      14       .,       .-      11    9 


13       IS 


(1 


9 


19 


a/ 


Fig,  1076. 

1.  The  brace-head, 

2.  The  common  rod. 

3.  The  double-box  rod;    intermediate 
piece. 

4.  The  common  chisel. 
6.  The  indented  chisel. 

6.  Another  of  the  same. 

7.  The  cross-mouthed  chisel. 

8.  The  wimble. 

9.  The    sludger,  for  bringing  up  the 
mud. 

10.  The  rounder. 


11.  The  key  for  supporting  the  train  of 
rods  at  the  bore-mouth. 

12.  The  key  for  screwing  together  and 

asunder  the  rods. 

13.  The  topit,  or  top-piece. 

14.  The  beche,  for  catching  the  rod  when 

it  breaks  in  the  bore. 

15.  The  runner,  for  taking  hold  of  the 
topit. 

16.  The  tongued  chisel. 

17.  The  right-handed  worm  screw. 

18.  The  left-handed     do. 

19.  The  finger  grip  or  catch. 


We  shall  now  explain  the  manner  of  conducting  a  series  of  bores  in  searching  ground 

for  coal.  , 

Fig,  1077  represents  a  district  of  country  in  which  a  regular  survey  has  proved 

the  existence  and  general  distribution  of  coal   strata,  with  a  dip  to  the  south,  at 

here  shown.      In  this  case,  a  convenient  spot  should  be  pitched  upon  in  the  north  part 


'^1 


'  \ 


N 


i 


398  PITCOAL. 

ot  the  district,  so  that  the  successive  bores  put  down  may  advance  in  the  line  of  the 

3     1077  4  5 

B 


PITCOAL. 


399 


nrnhrhk?  ^c  /  /k  '  Perforation,  many  diversfties  and  alternations  of  strata  will  be 
Tamv  an^thl  '''"^•^'  ^'  T-''l  ^".  '^'  '''''^'''  «^  '^^  ^^^^^a ;  each  of  which,  as  to 
?"seen  to  nPni^^T'fi'  ''  ""^^  ?  ^\'  J""'""^^'  ^"^  ^^P^cimens  are  preserved.     This  bore 

hat^he  din  nf  th^«  t  .  ^^u^^  ^'  ^'  ^  ?''  '^'*'^"'  encountering  any  coal.  Now,  suppose 
r?n  1  ?n  ^  of  the  strata  be  one  yard  m  ten,  the  question  is,  at  what  distance  from  bore 
WO.  1,  m  a  south  direction,  will  a  second  bore  of  60  yards  strike  the  first  stratum,  d,  of 
L  fin  win""   A  Tu^  "^^^  obviously  is,  to  multiply  the  depth  of  the  bore  by  the  dip,  that 

f  1  ..IaY^  the  product,  600,  gives  the  distance  required;  for,  by  the  rule  of  three, 
II  1  yard  ol  depression  corresponds  to  10  in  horizontal  length,  60  yards  of  depression 
will  correspond  to  600  in  length.  Hence  the  bores  marked  1,  2,  3,  4,  and  5,  are  succe  " 
sively  distributed  as  in  the  figure,  the  spot  where  the  first  is  let  do^n  being'r^a;ded  as 
the  point  of  level  to  which  the  summits  of  all  the  succeeding  bores  are  referred!    Should 

k1  n^^L  r  X'-  J^'^  ^^  ^?  ^f  ^'  ^'^^^'  **^  ^""^^^  ^^^"  t^e  t«P  «f  No.  1,  allowance  must 
be  made  for  this  diflerence  m  the  operation ;  and  hence  a  surface  level  survey  is  requisite. 
Sometmies  ravmes  cut  down  the  strata,  and  advantage  should  be  taken  of  them,  when 
they  are  considerable.  ' 

In  No.  2,  a  coal  is  seen  to  occur  near  the  surface,  and  another  at  the  bottom  of  the 
bore ;  the  latter  seam  resting  on  the  first  stratum  rf,  that  occurred  in  bore  No.  1 ;  and 
No.  2  perforation  must  be  continued  a  little  farther,  till  it  has  certainly  descended  to  the 
stratum  rf.    Thus  these  two  bores  have,  together,  proved  the  beds  to  the  depth  of  120  yards. 

No.  3  bore  being  placed  according  to  the  preceding  rule,  will  pass  through  two  coal- 
seams  near  the  surface,  and  after  reaching  to  nearly  its  depth  of  60  yards,  i1  will  touch 
the  ^  ratum  J,  which  is  the  upper  stratum  of  bore  No.  2;  but  since  a  seam  of  coal  was 
detected  in  No.  2,  under  the  stratum  h,  the  proof  is  confirmed  bv  running  the  borer  down 
through  that  coal.  The  field  has  now  been  probed  to  the  depth  of  180  yards.  The 
fourth  bore  is  next  proceeded  with,  till  the  two  coal-seams  met  in  No.  3  have  been  pene- 
trated ;  when  a  depth  of  240  yards  has  been  explored.  Hence  No.  4  bore  could  not  reach 
the  lower  stratum  a,  unless  it  were  sunk  240  yards. 

The  fifth  bore  (No.  5)  being  sunk  in  like  manner,  a  new  coal-seam  occurs  within  a 
few  yards  of  the  surface;  but  after  sinking  to  the  depth  at  which  the  coal  at  the  top  of 
the  fourth  bore  was  found,  an  entirely  different  order  of  strata  wiU  occur.  In  this 
dilemma,  the  bore  should  be  pushed  10  or  20  yards  deeper  than  the  60  yards,  to  ascertain 
the  alternations  of  the  new  range  of  superposition.  It  may  happen  that  no  coals  of  any 
value  shall  be  found,  as  the  figure  indicates,  in  consequence  of  a  slip  or  dislocation  of  the 
strata  at  b,  whic^  has  thrown  up  all  the  coals  registered  in  the  former  borings,  to  such  an 
extent  that  the  strata  6,  a,  of  the  first  bore  present  themselves  immediately  on  perforating 
the  slip,  instead  of  lying  at  the  depth  of  300  yards  (5  X  60),  as  they  would  have  done, 
had  no  dislocation  intervened.  Some  coal-fields,  indeed,  are  so  intersected  with  slips  a^ 
to  bewilder  the  most  experienced  miner,  which  will  particularly  happen  when  a  lower 
coal  IS  thrown  upon  one  side  of  a  slip,  directly  opposite  to  an  upper  coal  situated  on  the 
other  side  of  it;  so  that  if  the  two  seams  be  of  the  same  thickness,  erroneous  conclusions 
are  almost  inevitable. 

When  a  line  of  bores  is  to  be  conducted  from  the  dip  of  the  strata  towards  their  out- 
crop  they  should  be  placed  a  few  yards  nearer  each  other  than  the  rule  prescribes,  lest 
the  strata  last  passed  through  be  overstepped,  so  that  they  may  disappear  from  the  regis- 
ter, and  a  valuable  coal-seam  may  thereby  escape  notice.  In  fact,  each  successive  Iwre 
shou.d  be  so  set  down,  that  the  first  of  the  strata  perforated  should  be  the  last  passed 
through  in  the  Preceding  bore  ;  as  is  exemplified  by  viewing  the  bores  in  the  retrograde 
direction,  Nos.  4,  3,  and  2.  But  if  the  bore  No.  2  had  gone  no  deeper  than  /,  and  the 
bore  No.  1  had  been  as  represented,  then  the  stratum  c,  with  its  immediately  subjacent 
coal,  would  have  been  overstepped,  since  none  of  the  bores  would  have  touched  it ;  and 
they  would  have  remained  unnoticed  in  the  journal,  and  unknown. 

When  the  line  of  dip,  and  consequently  the  line  of  bearing  which  is  at  right  an^^les  to 
It,  are  unknown,  they  are  sought  for  by  makin?  three  bores  in  the  following  position 
—Let  Jig.  1078  be  a  hoi  izontal  diagram,  in  which   the  place  of  a  bore,  No     1    it 


shown,  which  reaches  a  coal-seam  at  the  depth  of  50  yards;  bore  No.  2  may  be  made 

at  B  300  yards  from  the  former ;  and  bore  No.  3  at  c,  equidistant  from  Nos.  1  and  2, 

'  so  that  the  bores  are  sunk  at  the  three  angles  of  an 

B  equilateral  triangle.  If  the  coal  occur  in  No.  2  at  the 
depth  of  30  yards,  and  in  No.  3  of  44  yards,  it  is 
manifest  that  none  of  the  lines  a  b,  b  c,  or  c  a,  is  in 
the  line  of  level,  which  for  short  distances  may  be 
taken  for  the  line  of  bearing,  with  coal-seams  of  mo- 
derate dip.  But  since  No.  1  is  the  deepest  of  the 
three  bores,  and  No.  3  next  in  depth,  the  line  a  c 
joining  them  must  be  nearer  the  line  of  level  than 
either  of  the  lines  a  b  or  b  c.  The  question  is,  there- 
fore, at  what  distance  on  the  prolonged  line  b  c  is  the 
point  for  sinking  a  bore  which  would  reach  the  coal 
at  the  same  depth  as  No.  1,  namely,  50  yards.  This  problem  is  solved  by  the  following 
rule  of  proportion :  as  14  yards  (the  difference  of  depth  between  bores  2  and  3)  is  to  300 
yards  (the  distance  between  them),  so  is  20  (the  difference  of  depth  betwixt  1  and  2)  to 
a  fourth  proportion,  or  x  =  428  yards,  1  foot,  and  8  inches.  Now,  this  distance,  measured 
from  No.  2,  reaches  to  the  point  d  on  the  prolonged  line  b  c,  under  which  point  d  the 
coal  will  be  found  at  a  depth  of  50  yards,  the  same  as  under  a.  Hence  the  line  a  d  is 
the  true  level  line  of  the  coal-field ;  and  a  line  b  f  g,  drawn  at  right  angles  to  it,  is  the 
true  dip-line  of  the  plane  which  leads  to  the  outcrop.  In  the  present  example  the  dip  is 
1  yard  in  14| ;  or  1  in  14 J,  to  adopt  the  judicious  language  of  the  miner ;  or  the  sine  is 
1  to  a  radius  of  14|,  measured  along  The  line  from  b  to  f.  By  this  theorem  for  finding 
the  lines  of  dip  and  level,  the  most  eligible  spot  in  a  coal-field  for  sinking  a  shaft  may  be 

Suppose  the  distance  from  b  to  g  in  the  line  of  dip  to  be  455  yards ;  then,  since  every 
14|  gives  a  yard  of  depression,  455  will  give  30  yards,  which  added  to  30  yards,  the 
depth  of  the  bore  at  b,  will  make  60  yards  for  the  depth  of  the  same  coal-seam  at  g. 
Since  any  line  drawn  at  right  angles  to  the  line  of  level  a  d  is  the  line  of  dip,  so  any 
line  drawn  parallel  to  a  d  is  a  level  line.  Hence,  if  from  c  the  line  c  e  be  drawn  paral- 
lel to  D  A,  the  coal-seam  at  the  points  e  and  c  will  be  found  in  the  same  horizontal  plane, 
or  44  yards  beneath  the  surface  level,  over  these  two  points.  The  point  e  level  with  c 
may  also  be  found  by  this  proportion :  as  20  yards  (the  difference  in  depth  of  the  bores 
under  b  and  a)  is  to  300  yards  (the  distance  between  them),  so  is  14  yards  (the  difference 
of  depth  under  b  and  c)  to  210  yards,  or  the  distance  from  B  to  e. 

As  boring  for  coal  is  necessarily  carried  on  in  a  line  perpendicular  to  the  horizon,  and 
as  coal-seams  lie  at  every  angle  of  inclination  to  it,  the  thickness  of  the  seam  as  given 
obliquely  by  the  borer,  is  always  greater  than  the  direct  thickness  of  the  coal ;  and  hence 
the  length  of  that  line  must  be  multiplied  by  the  cosine  of  the  angle  of  dip,  in  order  to 

find  the  true  power  of  the  seam. 

Of  fitting  or  vnnning  a  coal-field.— In  sinking  a  shaft  for  working  coal,  the  great 
obstacle  to  be  encountered  is  water,  particulariy  in  the  first  opening  of  a  field,  which 
proceeds  from  the  surface  of  the  adjacent  country ;  for  every  coal-stratum,  however  deep 
it  may  lie  in  one  part  of  the  basin,  always  rises  till  it  meets  the  alluvial  cover,  or  crops 
out,  unless  it  be  met  by  a  slip  or  dike.  When  the  basset-edge  of  the  strata  is  covered 
with  gravel  or  sand,  any  body  or  stream  of  water  will  readily  percolate  downwards 
through  it,  and  fill  up  the  porous  interstices  between  the  coal-measures,  till  arrested  by 
the  face  of  a  slip,  which  acts  as  a  valve  or  flood-gale,  and  confines  the  water  to  one  com- 
partment of  the  basin,  which  may,  however,  be  of  considerable  area,  and  require  a  great 
power  of  drainage. 

In  reference  to  water,  coal-fields  are  divided  into  two  kinds:  1.  level  free  coal ;  2. 
coal  not  level  free.  In  the  practice  of  mining,  if  a  coal-field,  or  portion  of  it,  is  so  situated 
above  the  surface  of  the  ocean  that  a  level  can  be  carried  from  that  plane  till  it  intersects 
the  coal,  all  the  coal  above  the  plane  of  intersection  is  said  to  be  level  free ;  but  if 
a  coal-field,  though  placed  above  the  surface  of  the  ocean,  cannot,  on  account  of  the 
expense,  be  drained  by  a  level  or  gallerj',  but  by  mechanical  power,  such  a  coal-field  is 
said  to  be  not  level  free. 

Besides  these  general  levels  of  drainage,  there  are  subsidiary  levels,  called  off-lakes  or 
drifts,  which  discharge  the  water  of  a  mine,  not  at  the  mouth  of  the  pit,  but  at  some  depth 
beneath  the  surface,  where,  from  the  form  of  the  country,  it  may  be  run  off  level  free. 
From  20  to  30  fathoms  off-take  is  an  object  of  considerable  economy  in  pumping ;  but 
even  less  is  often  had  recourse  to;  and  when  judiciously  contrived,  may  serve  to  inter- 
cept much  of  the  crop  water,  and  prevent  it  from  gelling  down  to  the  dip  part  of  the 
coal,  where  it  would  become  a  heavy  load  on  a  hydraulic  engine. 

Day  levels  were  an  object  of  primary  importance  with  the  early  miners,  who  had 
not  the  gigantic  pumping  power  of  the  steam-engine  at  their  command.  Levels  ought  ic 
be  no  less'^than  4  feet  wide,  and  from  5  feet  and  a  half  to  6  feet  high ;  which  is  large 


400 


PITCOAL. 


PITCOAL. 


Ml 


\    1 


'¥' 


i 

m 


VHf' 


enonghfor  carrying  off  waer,  and  admitting  workmen  to  make  repairs  and  clear  out 
depositions.  When  a  day-level  however,  is  to  serve  the  double  purpose  of  drainage 
and  an  outlet  for  coals,  it  should  be  nearly  5  feet  wide,  and  have  its  bottom  gutter 
covered  over.  In  other  instances  a  level  not  only  carries  off  the  water  from  the  col- 
hery,  but  is  converted  into  a  canal  for  bearing  boats  loaded  with  coals  for  the  market. 
Some  subterranean  canals  are  nine  feet  wide,  and  twelve  feet  high,  with  5  feet  depth  of 
water.  '^ 

If  in  the  progress  of  driving  a  level,  workable  coals  are  intersected  before  reaching 
the  seam  which  is  the  main  object  of  the  mining  adventure,  an  air-pit  may  be  sunk,  of 
inch  dimension  as  to  serve  for  raising  the  coals.  These  air-pits  do  not  in  general 
exceed  7  feet  m  diameter;  and  they  ought  to  be  always  cylindrical.  fLi019 
represents  a  coal-field   where  the  winning  is  made  by  a  day-level;  a  is  the  mouth 

fj  A  f  ll'^  ""^n ""  ^^""S  "^'^^  ^^^  ^^^  5  b,  c,  d,  e  are  intersected  coal-seams,  to  be 
drained  by  the  gallery.  But  the  coals  beneath  this  level  must  obviously  be  drained  by 
pumping.    A  represents  a  coal-pit  sunk  on  the  coal  e;  and  if  the  gallery  be  pushed 

1079  -^  ^ 


forward,  the  coal-seams  /,  g,  and  any  others  which  lie  in  that  direction,  will  also  be 
^ined  and  then  worked  by  the  pit  a.     The  chief  obstacle  to  the  execuron  of  day! 
kvels,  IS  presented  by  quicksands  in  the  alluvial  cover,  near  the  entrance  of  the  galled 
The  best  expedient  to  be  adopted  amid  this  difficulty  is  the  following —F^  1080 

ltrZTf'^\'''^'^.''^r?,'T^-^'^^  ^'  ^^^^  *he  alluvial  earth  a  I'  contaii?n^ 
the  bed  of  quicksand  6.  The  lower  part,  from  which  the  gallery  is  required  to  be 
carried  IS  shown  by  the  line  b  d.  But  the  quicksand  makes  it^impossibL  to  push 
forward  this  day-level  directly.  The  pit  b  c  must  therefore  \^  sunk  through  the  quTck- 
sand  by  means  of  tubbing  (to  be  presently  described),  and  when  the  pit  has  descended  a 
tZr/^^"  TV^'  '^^'  the  gaUery  or  drift  may  then  be  pushed  forward  to  the  poinTr! 
when  the  shaft  e  d  is  put  down,  after  it  has  been  ascertained  by  boring  that  the  rockl 

Sftl  "'l^Hn';  fy.'J''  'l^f  ^"^,*V^  -  -  '--^  y-ds  higher  than  the  mouth  of  the  smaU 
pit  B.     Durmg  this  operation,  all  the  water  and  mine-stuff  are  drawn  off  by  the  pit  b  • 

?«  iii"^    !;^rVn  I  f^^  ^""'^  ^""-*^'  ^"^^  communication  with  the  gallery,  the  wateJ 

tnlTZ  '^^"  ''r'T  "" '°  ^^*''?  "!"  "P  ^'^  '^^^'  ^"1  i^  o^^^flo^s  at  the  orifice  " 
From  the  surface  of  the  water  m  the  deep  shaft  at  g,  a  gallery  is  begun  of  the  common 
dimensions,  and  pushed  onwards  till  the  coal  sought  after  is  intersectSl.     In  this  waHo 

^^S^^:^r  a'btdtv'cS:  '-'^^"^^"^  ^^"^^'  ^'^  ^'"^  '--  ^'  ^^  ^--«^  ^^P^-> 

When  a  coal-basin  is  so  situated  that  it  cannot  be  rendered  level  free,  the  winnine 

rfcltTeta^e  ?-  ""'  •''"'""''-"^-    The  engine,  at  present  en>ployed  S  Z  dTT.;^! 

1.  The  water-wheel,  and  water-pressure  engine. 

2.  The  atmospheric  steam-engine  of  Newcomen. 

3.  The  steam-engine,  both  atmospheric  and  double  stroke,  of  Watt. 

4.  1  he  expansion  steam-engine  of  Woolf. 

-ru    5*  Tu*^®  high-pressure  steam-engine  without  a  condenser, 
nnwpr  nf  C      '•      ♦  ^t!  ^^^^^.^^^  ^  ^^u,  OT  to  be  drained  of  moisture,  regulates  the 
power  of  the  engine  to  be  applied,  taking  into  account  the  probable  quantity  of  water 
which  may  be  found,  a  circumstance  which  governs  the  diameter  of  th2  working  brrrete 
of  the  pumps.    Experience  has  proved,  that  in  opening  collieries,  even  in  new  fieWs 

«cernt^rL'tr"  ^  ''  '"^"  ^^  '^  P^-^P^  «^  ^^^^  ^0  t«  ^5  inches  diLeter; 
m^T^^ndl  aIIT^  r'^  connected  with  rivers,  sand-beds  filled  with  water,  oi 
flii-  ^H  ^^^^'^  ""^  "^^^^^  ^^«"™  *'ive'^  or  sand-beds  may  be  hindered  f^m 

.Srnt^nnr/"?''''/^"  growth  proceeding  from  these  sources  neid  not  rtaSn  i^to 
c^off  Lrn  thVlit'"'"^^^^^  '^"i^^"^  shafts,  that  though  the  influx  which  canno  be 

for  a  liSrwhnpTpt'  T\u^  *'  ^'.  ^"^y  ^''^'^  ^^^"  »>^y°"d  the  power  of  the  engine 
for  a  little  while,  yet  as  this  excessive  flow  of  water  is  frequently  derived  from  the 

foTsT  10  W? V  7fT''^^.  ^•'^"™?  manageable.  An  e%ine  lorl/nTtheTuii^ 
uL  Zhll  ZZT  ,^^\  ^''/  ""'^'^^""'^  «^^^«^te  to  the  winning  of  a  new  col- 
heiy,  which  reaps  no  advantage  from  neighboring  hydraulic  powers.  In  the  couri 
of  years,  however,  many  water-logged  fissures  com!  to  be  cut  b^the  workings,  and  the 

e^uT^n'd  f^J'^'T"^  T^:i'  '^'  ^"^"°P'  ^  t^^t  ^  <^«°«tant  increasf  if  water 
ensues,  and  thus  a  colliery  which  has  been  long  in  operation,  frequently  becomes  heav  ly 


loaded  with  water,  and  requires  the  action  of  its  hydraulic  machinery  both  nighV  and 

day. 

Of  Engine  Pits. — In  every  winning  of  coal,  the  shape  of  the  engine-pit  deserves 
much  consideration.  For  shafts  of  moderate  depth,  many  forms  are  in  use ;  as  circular, 
oval,  square,  octagonal,  oblong  rectangular,  and  oblong  elliptical.  In  pits  of  inconsider- 
able depth,  and  where  the  earthy  cover  is  firm  and  dry,  any  shape  deemed  nM)St 
convenient  maybe  preferred;  but  in  all  deep  shafts,  no  shape  but  the  circular  should 
be  admitted.  Indeed,  when  a  water-run  requires  to  be  stopped  by  tubbing  or  cribbing, 
the  circular  is  the  only  shape  which  presents  a  uniform  resistance  in  ever\'  point  to  the 
equable  circumambient  pressure.  The  elliptical  form  is  the  next  best,  when  it  deviates 
little  from  the  circle;  but  even  it  has  almost  always  given  way  to  a  considerable 
j)ressure  of  water.  The  circular  shape  has  the  advantage,  moreover,  of  strengthening 
^he  shaft  walls,  and  is  less  likely  to  suffer  injury  than  other  figures,  should  any  failure 
of  the  pillars  left  in  working  out  the  coal  cause  the  shaft  to  be  shaken  by  subsidence 
of  the  strata.     The  smallest  engine-pit  should  be  ten  feet  in  diameter,  to  admit  of  the 


1083 


1082 


1081 


pumps  being  placed  in  the  lesser  segment,  and  the 
coals  to  be  raised  in  the  larger  one,  as  shown  in 
fig,  1801  which  is  called  a  double  pit.  If  much  work 
is  contemplated  in  drawing  coals,  particularly  if  their 
masses  be  large,  it  would  be  advantageous  to  make 
the  pit  more  than  10  feet  wide.  When  the  area  of  a 
shaft  is  to  be  divided  into  three  compartments,  one  for  the  engine  pumps,  and  two  for 
raising  coals,  as  in  fg.  1082  which  is  denominated  a  triple  pit,  it  should  be  12  feet  in  di- 
ameter. If  it  is  to  be  divided  into  four  compartments,  and  made  a  quadrant  shaft,  as  in 
/??.  1088  with  one  space  for  the  pumps,  and  three  for  ventilation  and  coal  drawing,  the 
total  circle  should  be  15  feet  in  diameter.  These  dimensions  are,  however,  governed  by 
local  circumstances,  and  by  the  proposed  daily  discharge  of  coals. 

The  shaft,  as  it  passes  through  the  earthy  cover,  should  be  securely  faced  with  masonry 
of  jointed  ashler,  havin?  its  joints  accurately  bevelled  to  the  centre  of  the  circle.  Speci- 
fic directions  for  building  the  successive  masses  of  masonry,  on  a  series  of  rings  or 
cribs  of  oak  or  elm,  are  given  by  Mr.  Bald,  article  Mine,  Brewsier^s  EncyclopcfdiOy 

p.  336.  ,        ^  .        ^ 

When  the  alluvial  cover  is  a  soft  mud,  recourse  must  be  had  to  the  operation  of 
tubbing,  A  circular  tub,  of  the  requisite  diameter,  is  made  of  planks  from  2  to  3 
incheslhick,  with  the  joints  bevelled  by  the  radius  of  the  shaft,  inside  of  which  are  crib* 
of  hani  wood,  placed  from  2  to  4  feet  asunder,  as  circumstances  may  require.  These 
cribs  are  constructed  of  the  best  heart  of  oak,  sawn  out  of  the  natural  curvature  of  the 
wood,  adapted  to  the  radius,  in  segments  from  4  to  6  feet  long,  from  8  to  10  inches  in 
the  bed,  and  5  or  6  inches  thick.  The  length  of  the  tub  is  from  9  to  12  feet,  if  the 
layer  of  mud  have  that  thickness ;  but  a  succession  of  such  tubs  must  be  set  on  each 
other,  provided  the  body  of  mud  be  thicker.  The  first  tub  must  have  its  lower  edge 
thinned  all  round,  and  shod  with  sharp  iron.  If  the  pit  be  previously  secured  to  a 
certain  depth,  the  tub  is  made  lo  pass  within  the  cradling,  and  is  lowered  down  with 
tackles  till  it  rests  fair  among  the  soft  alluvium.  It  is  then  loaded  with  iron  weights  at 
top,  to  cause  it  to  sink  down  progressively  as  the  mud  is  removed  from  its  interior. 
Should  a  sin<»lc  tub  not  reach  the  solid  rock  (sandstone  or  basalt),  then  another  of  like 
1084  construction  is  set  on,  and  the  gravitating  force  is 

transferred  to  the  top.  Fig.  1084  represents  a  bed 
of  quicksand  resting  on  a  bed  of  impervious  clay, 
that  immediately  covers  the  rock,  a  is  the  finished 
shaft ;  a  a,  the  quicksand ;  6  6,  the  excavation 
necessarily  sloping  much  outwards;  c  c,  the  lining 
of  masonry ;    d   d,  the  moating   or  puddle  of 

_      ^ clay,  hard    rammed  in  behind  the  stone-work, 

to  render  the  latter  water-tight.  In  this  case,  the  quicksand,  being  thin  in  body, 
has  been  kept  under  for  a  short  period,  by  the  hands  of  many  men  scooping  it  rapidly 
away  as  it  filled  in.  But  the  most  effectual  method  of  passing  through  beds  of  quick- 
sand is  by  means  of  cast-iron  cylinders;  called,  therefore,  cast-iron  tubbing.  When 
the  pit  has  a  small  diameter,  these  tubs  are  made  about  4  feet  high,  with  strong  flanges, 
and  bolt  holes  inside  of  the  cylinder,  and  a  counterfort  ring  at  the  neck  of  the  flange, 
with  brackets ;  the  first  tub,  however,  has  no  flange  at  its  lower  edge,  but  is  rounded 
to  facilitate  its  descent  through  the  mud.  Should  the  pit  be  of  large  diameter,  then  the 
cylinders  must  be  cast  in  segments  of  3,  4,  or  more  pieces,  joined  together  with  inside 
vertical  flanges,  well  jointed  with  oakum  and  white  lead.  When  the  sand-bed  is 
thick,  eighty  "feet,  for  instance,  it  is  customary  to  divide  that  length  into  three  sets  of 
cylinders'^  each  thirty  feet  long,  and  so  sized  as  to  slide  within  each  other,  like  the  eye 
tubes  of  a  telescope.  These  cylinders  are  pressed  down  by  heavy  weights,  taking  care  to 
Vol.  II.  3  F 


h ; 


402 


PITCOAL. 


The  engine  pit  being  secured,  the  process  of  sinking  through  the  rock  is  ready  to  be 
commenced  as  soon  as  the  divisions  of  the  pit  form'ed  of  cipentrrcalleJ  b^^^^ 
are  made.     In  common  practice,  and  where  great  tightness  of  jointiris  not  reoS  f?; 
ventilating  inflammable  air,  bars  of  wood,  'called  buntons,  aC  finches  tS  and  9 
int^^n  ?'f  '"  ^  horizontal  posiUon  across  the  pit,  at  distances  from  each  mher  of  lO 
20,  or  30  feet,  according  to  circumstances.     Being  all  ranged  in  the  same  vertical  d  ane 

t^l'  fV''"u  ^".^  u  ^^^^  '^'""^  ^'•^  "^"^^  ^«  '^'^>  ^-i^h  «heir  joints  perfLuy  cLse  •  one 
half  of  the  breadth  of  a  bunton  being  covered  by  the  ends  of  the  deals      In  deeo  dUs 
where  the  ventilation  is  to  be  conducted  through  the  brattice,  the  side  of  the  buntons  S  < 
Uie  pumps  IS  covered  with  deals  in  the  same  way,  and  the  joints  are  ^Udered  secure  bv 
being  calked  with  oakum.     Fillets  of  wood  are  also  fixed  all  the  way  down  on  each  side 
of  the  brattice,  constituting  what  is  called  a  double  pit.  y  u  wn  on  eacn  side 

-^nn*"^"  rlh^^K^'^  have  3  compartments,  it  requires  more  care  to  form  the  brattice 
as  none  of  the  buntons  stretch  across  the  whole  space,  but  merely  meet  near  the  Sdd^e' 
and  join  at  certain  angles  with  each  other.     As  the  buntons  mus[  therefore  sistaCTeach 

rt    r  '"'"   ?K   ^'T^l^  °^  '^  ^''^*  '^'^^  ^'^  "«*  J^id  i"  »  horizontal  plane!  bit  have  a 

.  rise  from  the  sides  towards  the  place  of  junction  of  8  or  9  inches%nd   are  Zind 

S    n'n ^  *  three-tongued  iron  strap.     Fillets  of  wood  are  carri5^' down  the  whole 

depth,  not  merely  at  the  joinings  of  the  brattice  with  the  sides  of  the  pit  but  a^so  at 

^n"*  ''tH  tK  •'^^'k  °^"^^°V  ,^^^'^"  '"""^'^  P"'^'-^  *^«""e<^^  the  centre  of  each  se  of  bun 
Ind'sUffness?''  "''"'  ^"'^  '''''^-     ^'"'  ^'^  ^"^^^"^^^  ^^^^^  ^^^i^^^^  sufficient  strength 
In  quadrant  shafts  the  buntons  cross  each  other  towards  the  middle  of  the  pit  and 
are  generally  let  into  each  other  about  an  inch,  instead  of  bein-  half-checked      7^1  inSi 
IS  a  double  shaft  :  a  the  pump  pit;  b,  the  W  for  raising  c'oalS^^^^^^ 
shaft  ;m  which  A  IS  the  pump  compartment ;  b  and  c  are  coal-pits.     fI.  083  s  a  S 

Sr^ratji'g  co'alf  '""'  ''' '  ^'  ^'  ^'  ^^"^"^^^°"  ^'  "^^^^  ^-' ^«  smofij^fandTpiu" 

A  depth  of  75  fathoms  is  fully  the  average  of  en-ine  pits  in  Great  Britain      In 

practice,  it  embraces  three  sets  of  pumps.     Whenever  the  shaft  is  sunk  so  low  thai  the 

engine  IS  needed  to  remove  the  water,  the  first  set  of  pumps  may  be  let  down  bv  the 

method  represented  in  fig.  1085 ;  where  a  is  the  pump ;  S,  a,  strong  ear     hrou^h  wh  ch 

^lOSo^      pass  the  ,ron  rods  connected  with  the  spears  6  6 ;%  c  are  the  fasWngs ; 

rf,    he  hoggar  pump;   e,  the  hoggar;//,  the  tackles;  g  g,  the  single 

spears  By  this  mechanical  arrangement  the  pumps  are  sunk  in  the  most 
gradual  manner,  and  of  their  own  accord,  so  to  speak,  as  the  pit  descends 
7Z  ,T'  ""^  '^f  'f'!?'^'?''  '^^-^'  ^'^  ^^«ten^  with  ropes  or  chains  •' 
ttf'J  '^='%^''  loaded  with  weights,  as  counterpoises  to^he  weight  of 
the  column  of  pumps,  and  when  additional  pumps  are  joined  in  more 
weight  IS  laid  on  the  sledges.  As  the  sinking  se^f  pumps  fscinstrtlv 
descending,  and  the  point  for  the  delivery  of  the  water  above  a  w^sva^! 
ing,  a  pipe  of  equal  diameter  with  the  pumps,  and  about  11  feet  lonV  bit 
much  lighter  m  the  metal,  is  attached  to  e,  and  is  terminated  by  a  hose  of 
irlTVhir^^'TJ'l^V''  '•««<=^  the  cistern  where  the  wafer  is  deliv- 
enti  ^t^the  w  r*  '^'  hoggar-pipe.  In  sinking,  a  vast  quantity  of  iL 
enters  with  the  water,  at  every  stroke  of  the  engine ;  and  therefore  the  lift 

^frrf  .tp   '^"^^  ^'  ""V  ^^"^'  ^'^^  ^  momentary  stop  should  take  plac^ 
before  the  returning  stroke,  to  suffer  all  the  air  to  escape.    As  the  woSin^ 

fZ7rRt:rl'^  ^^  '^'r'  ^^"-^"^  the  fun  strokf of  the  enl  „! 

.vP!v'"^^  ll"^-^*"  ^""'.^  ""^^  °^  P"°^PS»  ^s  from  25  to  30  fathoms.     When- 
ever  this  depth  is  arrived  at  by  the  first  set,  preparations  a7e  made  for 


PITCOAL. 


403 


y\ 


BtUUI 


BTit  although  from  20  to  30  fathoms  be  the  common  length  of  a  pump-lift,  it  some. 

times  becomes  necessary  to  make  it  much  longer,  when  no  place  can  be  found  in  the 

1086       shaft  for  lodging  a  cistern,  on  account  of  the  tubbing.     Hence  a  pump-lift  has 

Ubeen  occasionally  extended  to  70  fathoms ;  which  requires  extraordinary  strength 
of  materials.  The  best  plan  for  collaring  the  pumps  in  the  pit,  and  keeping 
them  steady  in  a  perpendicular  line,  is  to  fix  a  strong  bunton  of  timber  under 
the  joints  of  each  pipe ;  and  to  attach  the  pipes  firmly  to  these  buntons  by  an 
iron  collar,  with  screws  and  nuts,  as  represented  in  Jig.  1086. 
The  water  obtained  in  sinking  through  the  successive  strata  is,  in  ordinary'  cases, 
conducted  down  the  walls  of  the  shaft ;  and  if  the  strata  are  compact,  a  spiral  groove  is 
cut  down  the  sides  of  the  shaft,  and  when  it  can  hold  no  more,  the  water  is  drawn  off  in 
a  spout  to  the  nearest  pump-cistern  ;  or  a  perpendicular  groove  is  cut  in  the  side  of  the 
shaft,  and  a  square  box-pipe  either  sunk  in  it,  flush  with  the  sides  of  the  pit,  or  it  is 
covered  with  deal  boards  well  fitted  over  the  cavity.  Similar  spiral  rings  are  formed 
in  succession  downwards,  which  collect  the  trickling  streams,  and  conduct  them  into  the 
nearest  cistern ;  or  rings,  made  of  wood  or  cast  iron,  are  inserted  flush  with  the  sides  of 
the  pipe ;  and  the  water  is  led  from  one  ring  to  another,  through  perpendicular  pipes, 
until  the  undermost  ring  is  full,  when  it  delivers  its  water  into  the  nearest  pump-cistern. 
Keeping  the  shaft  dry  is  very  important  to  the  comfort  of  the  miners,  and  the  durability 
of  the  work. 

When  an  engine  shaft  happens  to  pass  through  a  great  many  beds  of  coal,  a  gallery 
a  few  yards  long  is  driven  into  each  coal-seam,  and  a  bore  then  put  down  from  one  coal 
to  another,  so  that  the  water  of  each  may  pass  down  through  these  bores  to  the  pump- 
cisterns.  , 

While  a  deep  pit  is  sinking,  a  register  is  kept  of  every  part  of  the  excavations,  and 
each  feeder  of  water  is  measured  daily,  to  ascertain  its  rate  of  discharge,  and  whether  it 
increases  or  abates.  The  mode  of  measurement,  is  by  noting  the  time,  with  a  seconds 
watch,  in  which  a  cistern  of  40  or  50  gallons  gets  filled.  There  are  three  modes  of 
keeping  back  or  stopping  up  these  feeders ,  by  plank  tubbing ;  iron  tubbing ;  and  by 
oak  cribs.     Let  fig.  1087  represent  the  sinking  of  a  shaft  through  a  variety  of  strata, 

having  a  top  cover  of  sand,  with  much  water 
resting  on  the  rock  summit.  Each  plane  of  the 
coal-measure  rises  in  a  certain  direction  till  it 
meets  the  alluvial  cover.  Hence,  the  pressure  of 
the  water  at  the  bottom  of  the  tubbing  that  rests 
on  the  summit  of  the  rock,  is  as  the  depth  of 

water  in  the  superficial  alluvium  ;  and  if  a  stratum 

a  affords  a  great  body  of  water,  while  the  superjacent  stratum  6,  and  the  subjacent  c,  are 
impervious  to  water ;  if  the  porous  bed  a  be  12  feet  thick,  while  no  water  occurs  in  the 
strata  passed  through  from  the  rock  head,  until  that  depth  (supposed  to  be  50  fathoms 
from  the  surface  of  the  water  in  the  cover) ;  in  this  case,  the  tubbing  or  cribbing  mus 
sustain  the  sum  of  the  two  water  pressures,  or  62  fathoms ;  since  the  stratum  a  meets  the 
alluvial  cover  at  d,  the  fountain  head  of  all  the  water  that  occurs  in  sinking.  Thus  we 
perceive,  that  though  no  water-feeder  of  any  magnitude  should  present  itself  till  the  shaft 
had  been  sunk  lOO'fathoms;  if  this  water  required  to  be  stopped  up  or  tubbed  oflf  through 
the  breadth  of  a  stratum  only  3  feet  thick,  the  tubbing  floodgate  would  need  to  have  a 
stren^'th  to  resist  100  fathoms  of  water-pressure.  For  though  the  water  at  first  oozes 
merefy  in  discontinuoui  particles  through  the  open  pores  of  the  sands  and  sandstones, 
yet  it  soon  fills  them  up,  like  a  i-jriad  of  tubes,  which  transfer  to  the  bottom  the  totol 
weight  of  the  hydrostatic  column  of  100  fathoms ;  and  experience  shows,  as  we  have 
already  stated,  that  whatever  water  occurs  in  coal-pits  or  in  mines,  generally  speaking, 
proceeds  from  the  surface  of  lh«  ground.  Hence,  if  the  cover  be  an  impervious  bed  of 
clay  very  little  water  will  be  met  with  among  the  strata,  in  comparison  of  what  would  be 
found  under  sand. 

When  several  fathoms  of  the  strata  must  be  tubbed,  in  order  to  stop  np  the  water- 
flow,  the  shaft  must  be  widened  regularly  to  admit  the  kind  of  tubbing  that  is  to  be 
inserted;  the  greatest  width  being  needed  for  plank-tubbing,  and  the  least  for  iron- 
tubbing.     Fig.  1088  represents  a  shaft  excavated  for  plank-tubbing,  where  a,  a,  a  are  the 
1088  impervious  strata,  6,  b  the  porous  beds  water-logged,  and  c,  c  the  bottom 

of  the  excavation,  made  level  and  perfectly  smooth  with  mason- chisels. 
The  same  precautions  are  taken  in  working  oflf  the  upper  part  of  the 
excavation  d,  d.  In  this  operation,  three  kinds  of  cribs  are  employed  ; 
called  wedging,  spiking,  and  main  cribs.  Besides  the  stout  plank  for 
making  the  tub,  a  quantity  of  well-seasoned  and  clean  reeded  deal  is 
required  for  forming  the  joints ;  called  sheeting  deal  by  the  workmen. 
This  sheeting  deal  is  always  applied  in  pieces  laid  endwise,  with  the  end  of  the  fibres 
towards  the  area  of  the  pit.    Since  much  of  the  security  from  water  depends  on  the 


404 


mcOAL. 


1089    for  Ihe  loweTwXL  cnib  th.  ^ii  "i^P'"*"'"*  J"  /*•  1089.    To  make  room 

■m^H  and  from  4  to  "SnT  del  f^eUM  -n'"''''^  'J^''  '»•="*'  ^'''"'  «*  «'  '-• 

^''  of  oakum  is  intrXced      O^^iffK    '^  ?"•  """?."'  ""  ""='"'  <"  «  "•'■>  st™l"n> 

<k  ed  in  the  riks^re  of\hf  ni,  e»lh  J^*"'"? k '?''  ''J'  «PP"«J.«>»1  "'""y  joint- 

I,  and  at  each  of  iu  se^i„u'^^hee?^/de^?' i^''"fi™^» '""^''^  '"  ">*  "^"""i 

;  c^ii"ai^tl  ind'^a^MS'^L^-^^^^^^^^      r.1rhaefof'"r 

the  second  spiking  crib?  is  fixed  and  Inn^i;^       /  r'l"?."*  'J"^'""  ^"'^  ^^^^^  «"  ^ound, 

U.e°bti:aS'"7V  sTnterdeV'""  °''  '"^  ""'  "^X'  '■™"'  ^  ">  '  f"'  '-S,  10  inches  in 

he««L?hlru^eLt't^'"^iJl„Th^"''r  ''!}"•'"'  ™^'  '»  segments,  is  likely 

iron,  and  its  supS  strength  SSnraS'  '^T  i,""  ^'""  'i'^''""™  '»  '"«  P"«  «f 

in  the  circular  Less  oVTe'^.  cu'  ouTt'\tir^re«pUoT' Th^  f  ""^  ''T  'IP'"" 
»oint  is  best  turned  inwards.      Tn  i«to  ;  J         reception.     The  flange  for  the  wedg  ng 

Buddie,  where  il^eV^:r1\J:J:tto'^!^ZlT^^^^  --"^^^   by  Mr^ 

feet  Ion?,  2  feet  broad  and  an  m^iTii^l^i.-  .    hundred  feet,  the  segments  were  6 

the  back  the  %  of  the  flan^rwa/.trnnf ' 'S""'"'^^'^!?.'"''^  "^^  «^  '^'^'^  ^«rk  on 
of  the  iron  cylinder  axe  set  tfue  to  the  rnflu/I'fP*'^  by  brackets.  These  segments 
pendicular  jLt  is  iTade  t l^ht  w^?h  a  JatV  „f  ^^^^^^^^  T"^'  horizontal  and  per- 

at  the  bottom,  and  the  se^e^ts  arP  h  wu^f  *'?",^^^^:  ^  ^^^ging  crib  is  fixed 
This  kind  of  tubbrnVcanb^a^edt^^  iff ^  f'^?  ^^^^  j°^"^«  ^'^^  ashlerwork. 

surface,  or  till  strata  contafnfng  water  can  be^ubW  '\"  ""T  l^'^'  *"  ^"^^^^  «^  '^^ 
already  described.     A  shaft  finish^  in  thf«m«^  ''^'  ^^  ^^  *^^  '""^^^  °^  ^^^bing 

the  flanges  being  turn^  tow^slhe  out  d^n?  .h'  ^'TT  *  'T^'*'  Mining-wall  of  iron" 
screw  bdts  are  Leded  for  ,S^  th!  ^pI       ,V^  ?^^^^  ^"  ^^^^  ^^««  tubbing,  no 

in.  the  pit,  like"^t''stv^S•'f'car'Xrf^^^  as  they  are  packed  hard  ^h- 
trict,  where  70  fathoms  have  been  7^r»iJ-  V  ^^^^K  '"  *^^  Newcastle  dis- 
Buddle.  ^^'^  executed  m  this  way,  under  the  direction  of  Mr. 

war,^  whCtTe  t^ur'^'ofVe'Jj^L  'l'  ^"^^"'^"^  ^'^'^  ^'^^  -^  --^ 

1090        completdy  s?Zed  Vd  bv  ?h!\-  ''^""^''''  ^'^  7^^  ^"^y*  ^^^  ^^^^^  <^an  be 

—  cuto^en  with  chTsels  ^tol^d.h  rr'"^  ^T"!.'  ^C  ^"^«^"^-  ^he  fissure  ie 
sented  m  ^^1090  The  Tn  A  •  ''^*''  ^"?  ?  *^'J?'*'  ^'^  ^^^^"  ^"^^^^^  ^s  repre- 
pieces  ofcleL  deal  are  thiP,.^"'"^  rounded  off  about  an  inch  aid  a  half, 

contour  of  the  lips .  whe„  ?he  wh"/"?  "^^T  ^^^^  ^T^^*^^^  "«  ^''''^''  ^^an  the 
stopped.  By  sloping  b^ck  the  L^eVnfth^^^^  ''  firmly  wedged,  till  the  water  is  entirely 
the  stone,  it  is  not  liaWe  to  bui2  or  orLi^  ff -"'t^  ^"^  "^^^^^"^  ^«^^  ^'■«'»  t^^  f«ce  of 
way,  of  driving  in  the  wedge  dTecSy  ""    ^^  operation,  as  took  place  in  the  old 

onX^SifetaTp^^uTJ^aS^^  the  sinking  of  the  shaft  is  going 

__  ,  -lighter  i^  S^e  co'mpVtmem  t^^^^^  «^^  ^^"^  ^»^''»^' 

'l    square,    n  a Zrizontaldir";.?'  ^"r  '^  'Y"^  *  ^"*^^  «"«  «^  ^^^^  3  ffe 
to  an  ad^inTS  ohf.^^'°"'  from  the  mouth  of  that  compartment 

fuuio  w  w  leet  square  at  bottom,  and  tapering  upwards  to  3  or  4  feet 


PITCOAL. 


406 


1091 


0 


lJMI 


Muare  inside.  Such  a  furnace  and  chimney  are  also  needed  for  tentilating  the  coaL 
mine  through  all  its  underground  workings.  When  a  great  quantity  of  gas  issues  fron 
one  place  in  a  pit,  it  is  proper  to  carry  it  up  in  a  square  wooden  pipe,  which  terminating 
at  some  distance  above  the  surface  in  a  helmet-shaped  funnel,  fitted  to  turn  like  a  vane, 
may  cause  considerable  ventilation  of  itself;  or  the  top  of  such  a  pipe  may  be  connected 
with  a  small  fireplace,  which  will  cause  a  rapid  current  up  through  it,  from  the  pit. 
The  stones  and  rubbish  produced  in  sinking  are  drawn  up  with  horse-gins,  when  the  pit 
is  not  deep;  but  in  all  shafts  of  considerable  depth,  a  steam  engine  is  used,  and  the 
workmen  have  now  more  confidence  in  them,  as  to  personal  safety,  than  in  machines 

impelled  by  horses.  ,    «  j-  -j  j 

The  great  collieries  of  Newcastle  are  frequently  worked  by  means  of  one  shall  divided 
into  compartments,  which  serves  as  an  engine-pit,  and  coal-pits,  and  by  these  the  whole 
ventilation  is  carried  on  to  an  extent  and  through  ramifications  altogether  astonishing. 
This  system  has  been  adopted  on  account  of  the  vast  expense  of  a  large  shaft,  often 
amounting  to  60,000f.  or  80,000/.,  including  the  machinery.  The  British  collieries,  how- 
ever are  in  general  worked  by  means  of  an  engine-pit,  and  a  series  of  other  pits,  sunk  at 
proper  distances  for  the  wants  of  the  colliery. 

WORKING  OF  COAL. 

A  stratum,  bed,  or  seam  of  coal,  is  not  a  solid  mass,  of  uniform  texture,  nor  always 
of  homogeneous  quality  in  burning.  It  is  often  divided  and  intersected,  with  its  con- 
comitant strata,  by  what  are  named  partings,  backs,  cutters,  reeds,  or  ends.  Besides 
the  chief  partings  at  the  roof  and  pavement  of  the  coal  seam,  there  are  subordinate  lines 
of  parting  in  the  coal  mass,  parallel  to  these,  of  variable  dimensions.  These  divisions 
are  delineated  in  fig,  1092  where  A,  d,  c,  d,  e  f  g  d,  represent  a  portion  of  a  bed  of  coal, 

„ c  the   parallelogram   A  b  d  c  the   parting   at   the   roof, 

"X"^     1092  and  E  F  G  the  parting  at  the  pavement ;  ab,bc,de, 

and  e /,  are  the  subordinate  or  intermediate  partings; 
g  h,  i  fc,  I  m,  the  backs ;  o  /),  p  g,  r  »,  »  <,  a  r,  and  v  to, 
the  cutters.  It  is  thus  manifest  that  a  bed  of  coal,  ac- 
ja  cording  to  the  number  of  these  natural  divisions,  is  sub- 
-a  divided  into  solid  figures  of  various  dimensions,  and  of  a 
"•g  cubical  or  rhomboidal  shape. 
When  the  engine-pit  is  sunk,  and  the  lodgment  formed,  a  mine  is  then  run  in  the 
coal  to  the  rise  of  the  field,  or  a  cropping  from  the  engine-pit  to  the  second  pit.  This 
mine  may  be  6  or  8  feet  wide,  and  carried  either  in  a  line  directly  to  the  pit  bottom,  or 
at  right  angles  to  the  backs  or  web  of  the  coal,  until  it  is  on  a  line  with  the  pit,  where 
a  mine  is  set  off,  upon  one  side,  to  the  pit  bottom.  This  mine  or  gallery  is  carried  as 
nearly  parallel  to  the  backs  as  possible,  till  the  pit  is  gained.  Jtg.  1093  represents  this 
1093  *  •  ■  ■     '"  ""'^      ~  "■  "  " 


A  is  the  engine-pit. 
by-pitr  AC,  the  gallery  driven  at  right  angles  to  the  backs, 
p  c  B,  the  gallery  set  off  to  the  left  hand,  parallel  to  the  backs. 
The  next  step  is  to  drive  the  drip-head  or  main-levels  from 
the  engine-pit  bottom,  or  from  the  dtp-hand  of  the  backset 
immediately  contiguous  to  the  engine-pit  bottom.  In  this 
business,  the  best  colliers  are  always  employed,  as  the  object 
is  to  drive  the  gallery  in  a  truly  level  direction,  independently  of  all  sinkings  or  risings 
of  the  pavement.  For  coal  seams  of  ordinary  thickness,  this  gallery  is  usually  not  more 
than  6  feet  wide ;  observing  to  have  on  the  dip  side  of  the  gallery  a  small  quantity  of 
water,  like  that  of  a  gutter,  so  that  it  will  always  be  about  4  or  6  inches  deep  at  the 
forehead  upon  the  dip-wall.  When  the  level  is  driven  correctly,  with  the  proper  depth 
of  water,  it  is  said  to  have  dead  water  at  the  forehead.  In  this  operation,  therefore,  the 
miner  pays  no  regard  to  the  backs  or  cutters  of  the  coal;  but  is  guided  in  his  line  of 
direction  entirely  by  the  water-level,  which  he  must  attend  to  solely,  without  regard  to 
slips  or  dislocations  of  the  strata  throwing  the  coal  up  or  down.  In  the  last  figure,  the 
coal-field  is  a  portion  of  a  basin  ;  so  that  if  the  shape  be  uniform  and  unbroken,  and  if 
any  point  be  assumed  a  dipping  from  the  crop,  as  d,  the  level  lines  from  that  point  will 
be  parallel  to  the  line  of  crop,  as  d  e,  d  f,  and  the  levels  from  any  point  whatever  a-dip- 
ping,  will  be  also  parallel  to  these ;  and  hence,  were  the  coal-field  an  entire  elliptical 
basin,  the  dip-head  levels  carried  from  any  point  would  be  elliptical,  and  parallel  to  the 
crop.  If,  as  is  more  commonly  the  case,  the  coal-field  be  merely  a  portion  of  a  basin, 
1094  _  *  _  formed  by  a  slip  of  the   strata,  as  represented  in  yig.  1094 

^^^''''^''Zji^Z^^^^  where  a,  o,  a,  is  the  crop,  and  a  b,  a  slip  of  great  magnitude, 
Ycy/'  ^ ?""^^^Crf^  forming  another  coal-field  on  the  side  c,  then  the  crop  riot 
B  c  A  only  meets  the  alluvial  cover,  but  is  cut  off  by  the  slip  at  A 

and  at  b.     Should  any  point,  therefore,  be  assigned  for  an  engine-pit,  the  levels  from 
k  will  proceed  in  a  line  parallel  *»>  the  crop,  as  d  (2,  d  c,  and  the  level  on  both  sides  v& 


mining  operation. 


B,  the  second  or 


406 


PITCOAL. 


PITCOAL. 


4OT 


^"„Te?;  Tu'  v'/li^e"  r^ele'adf^o  r  "l    r'"  '«»«'"«.«'"=  P-"  incloded  be. 
What  is  no,  i«clad:dVu  S;2i  rhe^^XS^^Vr^^  the  engine-pi.  „ , 

WorWn^'w^r'n'n"*  ""•". '"""'■  '"""'^"'  *>-^'«'»^  <""  *»"'»?  coal-mines  - 
bent  strata.  excavated,  as  is  just  adequate  to  tlie  support  of  tlie  incom- 

erL^"ay"L*;ea«S Tlf  h*"'  "T  """  "'■"'"^  ""= '«"  "^  =">  «'™  ^i-c,  and  strong, 
a  considSable  portirof  each  ras^L'^^Mf '^  '"•'"''  ."■""  ""^  '"•«■"'»"  "^  '•«'»°ving 
stall  has  been  finiS  Tn  the  coXe^     ^       '  *"™""  '*'  "^^"  """""g  of  post  and 

the  pits,  whenever  ther^nin?-  ?  s  left,  with  the  view  of  working  back  towards 
«od  fhen  Tak^ra;  a^"""'^!''  "''*fVr  "?i'  ■"*"","  '"  ""^  «'»«  of  the  coal-deld! 

'T'tJirir-^  "^^^^^^^^^^^  '"^  """'^  ^"*'"- 

takes  r.'ar?hecVaTL:.7«stve"irJs^^^^  '"^;''"''  ""'=•'  "="«  »»  P""-'  •>„. 

ben.  strata  erush  d^tnrSrJ^erTcteTrttlJe:  sTf^he  ^lU^t'  ^"'"'  '"=  *»'=""'- 
mel^'o^dr  d'::;.t"'^eriU.  Kifc  l'"  r-'^^  f  -^  ""icTn":^-     The  Shropshire 
this  mode  has'beln'foSi^pTictiiabi;'"'' '  '"'  ""'"  '"*  """""'^  '"'«•'  «  "'  '<•«'. 
The  followmg  considerations  must  be  had  in  view  in  establishing  a  coal  mine  • 

the' wo^rti  irtrviittf  rt^f::;it^of  xrii"  zt^  r  ?^f  F-r 

upper  coals  should  be  worked  in  the  first  place  '  "  '*""'"  '^  '''"'''  ">« 

ness  of  thVwiraTd  eutTe^'""'  ''  '°  ''"""'  """'■'«''  ^""«^' '"«  number  and  open- 

aess^'at  i?s"^,ro  whaTdirth"/t  mlvyrj  "»■"'  """-"'^  «  ">  ""*-  -<•  -"- 

6    The  "^"' r  "^  '?^»"""="  'over  of  the  ground,  as  to  wa  er  nuicksands  &c 
the  •clf  st™r  "■"  "'  "''"'  "'^-^'  "  «"«-"«'  P«"'-'"'y  if  -rbfnr 't'he'^utcrop  of 

^^r^Bald  gtves  the  following  general  rules  for  det^rmbirgthe  best  mode  of  working 

m^tfrottL^ntrel^h  o^h^r^rLp^^dfnAo^^^^^^^  "r^T' '"'  "'""'  »■«>  ™-^ 
providing  all  the  coal  prono«;d  to  be  w?o^,  J^,.  ?f .  J  ° "'"''"'  ^^'^''J^  «»P=ri"cumbent  strata. 

Sit :','» =SSS  E  =■'"  ?~=^^^^^^^ 

structionof  the  pillars,  termedTm,^hnr«;-'    if-  ?'u^  °^  7'''^'*  ^^"^^  ^«  «  total  de- 
Hoses  up  the  Jrk.    '  ""'*"  ""^  ''^^  '"^  ^*^^^'^  ^^^  roof  sinks  to  the  pavement,  and 

^nlL'iZZ^^o:^^^^^^^^  P^^^-  or  an  extra  size  are  required, 

sued  in  the  workin-  but  if  ZylTsoh\hi^L^^"'^  ^f""'^-  »°^»tioned  may  be  pur- 
width,  and  with  pillars  of  g  eat  e^fra  strei^th  bv  whJnh  T'^  ^'^^  '"^"^  «^  ^  '"^derate 
be  got  out  at  the  last  of  the  m^jS  when  the  minpr«'j  '*"!  ^'^T'  ^''''  ""^'^^  <^«^1  ^^7 
finish  the  workings  of  a  pit."         '  ^  "'•"^''  '^*'^*'  ^«  ^^«  P^^  l>ottom,  and  ther* 

me^^a^'p^SratVep^^^^^^^^  '^^  P-- 

and  a  room,  with  the  roof  str?tnmK//'  ^^^  ^^'l^^its  l^rge  pillars 
Thus  the  riads  w  11  be  shut  1  ,h.  '''°=  ''^''"  ^'^^"*^  ^*  ^«"«  ^^  a. 
Whole  economy  ofll/^S,?;^^^^^^^^^^^^  -^  ^he 

When  an  the  eoai  intenS^  ^T^Z::^.^^  ^J  fi^^^^^  ^^^^ 


1097 


four  fifths  to  two  thirds ;  but  as  the  loss  of  even  one  third  of  the  whol*  area  of  coal  ts  far 
too  much,  the  better  mode  of   working  suggested  in  the  third  system  ought  vo  b« 
adopted. 
The  proportion  of  a  winning  to  be  worked  may  be  thus  calculated.     Let  fig.  1097  be  « 
"■  ""*'  small  portion  of  the  pillars,  rooms,  and  thirlings  formed  in  a  coal-field ; 

a,  a,  are  two  rooms  j  6,  the  pillars ;  e,  the  thirlings  (or  area  worked  out). 
Suppose  the  rooms  to  be  12  feet  wide,  the  thirlings  to  be  the  same,  and 
the  pillars  12  feet  on  each  side ;  adding  the  face  of  the  pillar  to  the  width 
of  the  room,  the  sum  is  24 ;  and  also  the  end  of  the  pillar  to  the  width 

of  the  thirling,  the  sum   is  likewise  24  :  then  24x24=576 ;  and  the 

"5  S^  £  area  of  the  pillar  is  12X12=144;  and  as  576  divided  by  144  gives  4 
for  a  quotient,  the  result  is,  that  one  fourth  of  the  coal  is  left  in  pillars,  and  three 
fourths  extracted.  Let  rf,  «,/,  g,  be  one  winning,  and  g,  e,  fc.  A,  another.  By  inspect- 
ing the  figure,  we  perceive  the  workmgs  of  a  coal-field  are  resolved  into  quadrangular 
areas,  having  a  pillar  situated  in  one  of  the  angles. 

In  forming  the  pillars  and  carrying  forwards  the  boards  with  regularity,  especially 
where  the  backs  and  cutters  are  very  distinct  and  numerous,  it  is  of  importance  to  work 
the  rooms  at  right  angles  to  the  backs,  and  the  thirlings  in  the  direction  of  the  cutters, 
however  oblique  these  may  be  to  the  backs,  as  the  rooms  are  by  this  means  conducted 
with  the  greatest  regularity  with  regard  to  each  other,  kept  equidistant,  and  the  pillars 


1098 


are  strongest  under  a  given  area.  At  the  same  time,  however,  il  seldom 
happens  that  a  back  or  cutter  occurs  exactly  at  the  place  where  a  pillar 
is  formed ;  but  this  is  of  no  consequence,  as  the  shearing  or  cutting 
made  by  the  miner  ought  to  be  in  a  line  parallel  to  the  backs  and  cut- 
ters. It  frequently  happens  that  the  dip-head  level  intersects  the  cut- 
ters in  its  progress  at  a  very  oblique  angle.  In  this  case,  when  rooms 
and  pillars  are  set  off,  the  face  of  the  pillar  and  width  of  the  room 
must  be  measured  off  an  extra  breadth  in  proportion  to  the  obliquity, 
-..„^.  as  in  fig.  1098.  By  neglect  of  this  rule,  much  confusion  and  irregular 
work  are  often  produced.  It  is,  moreover,  proper  to  make  the  fiist  set  of  pillars  next  the 
dip-head  level  much  stronger,  even  where  there  is  no  obliquity,  in  order  to  protect  that 
level  from  being  injured  by  any  accidental  crush  of  the  strata. 

We  shall  now  explain  the  different  systems  of  working  :  one  of  the  simplest  of  which 
is  shown  in  fig.  1099 ;  where  a  represents  the  engine-pit,  b  the  by-pit,  c  d  the  dip-head 

levels,  always  carried  in  advance  of  the  rooms, 
and  E  the  rise  or  crop  gallery,  also  carried  in  ad- 
vance. These  galleries  not  only  open  out  the 
work  for  the  miners  in  the  coal-bed,  but,  being 
in  advance,  afford  sufficient  time  for  any  requisite 
operation,  should  the  mines  be  obstructed  by 
dikes  or  hitches.  In  the  example  before  us,  the 
rooms  or  boards  are  worked  from  the  dip  to  the 
crop;  the  leading  rooms,  or  those  most  in  ad- 
vance, are  on  each  side  of  the  crop  gallery  e  ;  all 
the  other  rooms  follow  in  succession,  as  shown 
in  the  figure ;  consequently,  as  the  rooms  ad- 
1^ —  vance  to  the  crop,  additional  rooms  are  begun 
at  the  dip-head  level,  towards  c  and  d.  Should  the  coal  work  better  in  a  level-course 
direction,  then  the  level  rooms  are  next  the  dip-head  level,  and  the  other  rooms  follow 
in  succession.  Hence  the  rooms  are  carried  a  cropping  in  the  one  case,  till  the  coal  is 
cropped  out,  or  is  no  longer  workable ;  and  in  the  other,  they  are  extended  as  far  as  the 
extremity  of  the  dip-head  level,  which  is  finally  cut  off,  either  by  a  dike  or  slip,  or  by  the 
boundary  of  the  coal-field. 

When  the  winnings  are  so  very  deep  as  from  100  to  200  fathoms,  the  first  workings 
are  carried  forward  with  rooms,  pillars,  and  thirlings,  but  under  a  different  arrangement, 
on  account  of  the  great  depth  of  the  superincumbent  strata,  the  enormous  expense 
incident  to  sinking  a  pit,  and  the  order  and  severity  of  discipline  indispensable  to  the  due 
ventilation  of  the  mines,  the  preservation  of  the  workmen,  and  the  prosperity  of  the 
whole  establishment.  To  the  celebrated  Mr.  Buddie  the  British  nation  is  under  the 
greatest  obligations  for  devising  a  new  system  of  working  coal-mines,  whereby  nearly 
one  third  of  the  coals  has  been  rescued  from  waste  and  permanent  destruction.  This 
system  is  named  panel  work ;  because,  instead  of  carrying  on  the  coal-field  winning  in 
one  extended  area  of  rooms  and  pillars,  it  is  divided  into  quadrangular  panels,  each  panel 
containing  an  area  of  from  8  to  12  acres ;  and  round  each  panel  is  left  at  first  a  solid 
wall  of  coal  from  40  to  50  yards  thick.  Through  the  panel  walls  roads  and  air-courses 
are  driven,  in  order  to  work  the  coal  contained  within  these  walls.  Thus  all  the  panels 
are  connected  together  with  the  shaft,  as  to  roads  and  ventilation.    Fach  disUict  or 


□  G  Q  O  E  E^P a  Q  m  0  E3 


^B^Z3-tI7>tZ3E3-d 


2E 


i'mn 


408 


PITCOAL. 


V. 


T' 


i<i 


referred  to  a  specific  place        "'™™*'  ''eaUlaUon,  and  ihe  safety  of  the  workmen,  can  b« 

Fig.  1 100  represents  a  part  of  a  collierr  laiV  o,.t  i„  <• 
».^oved  tnethc..     To  reader  it  as  ^S .^'^^^^^Z^^'^^  ^^  uM°ri^tt 


PITCOAL. 


4(^ 


lirnref  Xt^ei:^^^^^^^  fj^e  coal,  x  is  the  ^^i:.— 

coal-pits  is  the  down-cast,  by  wS  the  a^minr  .*=°^l-P?^^', ^'^^  ^ST-  1082.  One  of  ihe 
works;  the  other  coal-pit  is  thrupcastshlr^t^^^^^^  ^l  ?  ^'^T  ^°^^"  ^°  ^^"^ilate  the 
the  air  is  placed,  b  c,  is  the  dip-head  lever  a  v  Th  '•  ^''"^^  ^^'  ^"'""^^^  ^^'^  ^"refving 
walls;  F,G,are  two  Wis  X?etd  a^^^  k,k,  the  panel 

rooms  a,  a,  a,  in  regular  progress  toihe  rise  •  h  if  n  T""^  i-  n'  ''  ""  ,P^"^^'  ^^^'^^  the 
nearly  all  the  coal  has  beeii  extractwl  n.i  i.V  '  .P""^'  ^""^  ^^''^^^^  out,  whence 
tenth,  instead  of  a  third,  or  even  a  hf If  brtiTolZTh''';^  'V'l'"^^  *«  "«  '"''•^^  ^han^ 
also,  the  pillars  of  a  Wl  mayT  worL  o^^^^^^^^^  ^y  th.splan  of  Mr.  Buddie^ 
economy  of  the  mining  operation  f  wJereafformer  v  ho-h  \^'  "?"''  f'^"**'^  ^«^  '^^ 
general  arrangement  of  the  mine  were  made  ^fht hi  ."^  ^  /  '/^^  ^'^  ^^^  ^'^^^'^  ^nd 
great  proportion  of  the  pillars,  yet  rfrLuent^vTnnnl  ^  7^  ""i  i.«^''"?«"t  ultimately  a 
pushed  to  the  proposed  extenf  somrmrt  of  ^hT  ^'^  *^^^'  **'^°'^  ^^^  ^^^^i"?^^  ^ere 
crush;  but  the  most  common  ^Wort^Lw^s  the  n^^^^^^^  ^'^^'^  « 

deranging  the  whole  economy  of  the  field     Indeed  th.  -    'I"^  '"*"  »»»e^  pavement,  and 
whole  of  the  pillars,  and  was  resis  ed  only  by  the^ntire^^^^^  ^^^^''^^n  the 

that  the  ventil-vtion  was  entirely  destroyed  thl^^lf  ^^  r '^''^  ^^  *^^  ^a"  ^aces ;  so 
pit-bottom  shut  .p  and  rendered  use^Ss  and  thTrecov^;^"^^^^^^  '^^  '^^^  ^^*^^^  »«  the 
new  air-courses,  new  roads,  and  by  ^fSn^n^  up  thTwa^^^^^^^  '^'  '""^"'^  ^^^  "^^«"^  «f 
with  prodigious  expense  and  danger  Even'when  thJ  n  '  «^^«<>ms,  was  attended 
was  attended  with  other  very  gr^Unconvenkrces  If  .S«  '""k''^^  ^'"'  '^^  «"  "^^hod 
spot  of  the  colliery,  it  was  quite  imposX Tai^'est  fts  nro'/r.^^  T  '"  ^^^  P*'^'*^"'" 
tf  the  ventilation  was  thereby  obstructed,  no  ide^^oud  hlZTJ''  l^^  "J^^^^'P^^  ^  ^^'^ 
be  found,  there  being  instances  of  no  less  than  30  mnil  ?  "'^  ^^^^^  ^he  cause  might 
And  If  from  obstruct^  ventilation  an  explosion  o^^^^^^  ""«  «>"iery- 

workmen  were  occupied  abng  the  extended  waH  flic  .  '"^^^  ^""'"'"^^  ^^"^  '"any 
where  the  disaster  had  taken  place  rnorcouW^h/vL'  '^  '^^',  "°*  P«^«^»>^«  »«  determinJ 
bnng  relief  to  the  forlorn  and  mutuktS  survte's  """  ^"^  '"^"^^^^  ^»«^  ^^^^^  to 

In  Mr.  Buddie's  system  all  these  evils  ar^  a„«r^^ 
JUKI  foresight  can  go.'  He  makesIL  p  la^v?^^  w/f  i"f^  ^^  ^"  ««  ^»°^«n  science 
the  pillars  being  in  general  12  yards  broaJl^nd  I4  ^2^^  ? '*'^"'\**'' *^««"^^  "«"<>w  ? 
wide,  and  the  walls  or  thirlings  cut  through  th!  -if  ^^"^^  ^°"^  '  t''^  ^ards  4  yards 
6  feet  wide,  for  the  purpose  of^venSlto^  A  thl^  fil"  ^T  """  ^"^^  ^«  another,'only 
proceeding  from  the  dip  to  the  crop,  and  the  paneTwaI?r!.it^  'T'  ^'^  '^Presented  as 
the  area  of  the  panel,  to  prevent  the  wei-hf  nf  tV  ^^  *^  ^^'■"^^s  thrown  round 

running  the  adjoining  panels.    Again  when  thp  i;/    '"Pf^'"<^""»>ent  strata  from  over- 

rauge  of  pillars,  as  aluin  hV  is  /rst  at^'ed    /n^LX  t'T     ^''  *"  '^  ^«^^^^>  «»« 

uttijiea ,  and  as  the  workmen  cut  away  the  furthest 


pillars,  columns  of  prop-wood  are  erected  betwixt  the  pavement  8Jid  the  roof,  within  • 
few  feet  of  each  other  (as  shown  by  the  dots),  till  an  »rea  of  above  100  square  yards  ia 
cleared  of  pillars,  presenting  a  body  of  strata  perhaps  130  fathoms  thick,  suspended 
clear  and  without  support,  except  at  the  line  of  the  surrounding  pillars.  This  operation 
is  termed  working  the  goaff.  The  only  use  of  the  prop-wood  is  to  prevent  the  seam, 
which  forms  the  ceiling  over  the  workmen's  heads,  from  falling  down  and  killing  them 
by  its  splintery  fragments.  Experience  has  proved,  that  before  proceeding  to  take  away 
another  set  of  pillars,  it  is  necessary  to  allow  the  last-made  goaff  to  fall.  The  workmet 
then  begin  to  draw  out  the  props,  which  is  a  most  hazardous  employment.  They  begii 
at  the  more  remote  props,  and  knock  them  down  one  after  another,  retreating  quickl) 
under  the  protection  of  the  remaining  props.  Meanwhile  the  roof-slralum  begins  tc 
break  by  the  sides  of  the  pillars,  and  falls  down  in  immense  pieces ;  while  the  workmei 
still  persevere,  boldly  drawing  and  retreating  till  every  prop  is  removed.  Nay,  should 
any  props  be  so  firmly  fixed  by  the  top  pressure,  that  they  will  not  give  way  to  the  blow» 
of  heavy  mauls,  they  are  cut  through  with  axes ;  the  workmen  making  a  point  of  bona 
to  leave  not  a  single  prop  in  the  goaff.  The  miners  next  proceed  to  cut  away  the  pillarr 
nearest  to  the  sides  of  the  goaff,  setting  prop-wood,  then  drawing  it,  and  retiring  as  be 
fore,  until  every  panel  is  removed,  excepting  small  portions  of  pillars  which  require  to  be 
left  under  dangerous  stones  to  protect  the  retreat  of  the  workmen.  "While  this  operatioi 
is  going  forward,  and  the  goaff  extending,  the  superincumbent  strata  being  exposed  with 
out  support  over  a  large  area,  break  progressively  higher  up;  and  when  strong  beds  ol 
sandstone  are  thus  giving  way,  the  noise  of  the  rending  rocks  is  very  peculiar  and  terrific ; 
at  one  time  loud  and  sharp,  at  another  hollow  and  deep. 

As  the  pillars  of  the  panels  are  taken  away,  the  panel  walls  are  also  worked  progres- 
sively backwards  to  the  pit  bottom ;  so  that  only  a  very  small  proportion  of  coal  is  even- 
tually lost.  This  method  is  undoubtedly  the  best  for  working  such  coals  as  those  of  New- 
castle, considering  their  great  depth  beneath  the  surface,  their  comparative  softness,  and 
the  profusion  of  inflammable  air.  It  is  evident  that  the  larger  the  pillars  and  panel  walls 
are,  in  the  first  working,  the  greater  will  be  the  security  of  the  miners,  and  the  greater  the 
certainty  of  taking  out,  in  the  second  stage,  the  largest  proportion  of  coal.  This  system 
may  be  applied  to  many  of  the  British  collieries  ;  and  it  will  produce  a  vast  quantity  of 
coals  beyond  the  post  and  stall  methods,  so  generally  persisted  in. 

In  thus  tearing  to  pieces  the  massive  rocks  over  his  head,  the  miner  displays  a  deter- 
mined and  cool  intrepidity ;  but  his  ingenuity  is  no  less  to  be  admired  in  contriving  modes 
of  carrying  currents  of  pure  atmospheric  air  through  every  turning  of  his  gloomy  labyrinth, 
so  as  to  sweep  away  the  explosive  spirit  of  the  mine. 

The  fourth  system  of  working  coal,  is  called  the  long  way,  the  long-wall,  and  the  Shrop- 
shire method.  The  plan  must  at  first  have  been  extremely  hazardous ;  though  now  it  is  so 
improved  as  to  be  reckoned  as  safe,  if  not  safer,  to  the  workmen,  than  the  other  methods, 
with  rooms  and  pillars. 

The  object  of  the  Shropshire  system,  is  to  begin  at  the  pit-bottom  pillars,  and  to  cut 
away  at  once  every  inch  of  coal  progressively  forward,  and  to  allow  the  whole  superin- 
cumbent stratr  50  crush  down  behind  and  over  the  heads  of  the  workmen.  This  plan 
is  pursued  chieriy  with  coals  that  are  thin,  and  is  very  seldom  adopted  when  the  seam  is 
7  feet  thick ;  fiom  4  to  5  feet  being  reckoned  the  most  favorable  thickness  for  pro- 
ceeding with  comfort,  amidst  ordinary  circumstances,  as  to  roof,  pavement,  &c.  "When 
a  pit  is  opened  on  a  coal  to  be  treated  by  this  method,  the  position  of  the  coals  above 
the  lowest  seam  sunk  to,  must  first  be  considered ;  if  the  coal  beds  be  contiguous,  it 
will  be  proper  to  work  the  upper  one  first,  and  the  rest  in  succession  downwards ;  but 
if  they  are  8  fathoms  or  more  apart,  with  strata  of  strong  texture  betwixt  them,  the 

working  of  the  lower  coals  in  the  first  place  will  do 
no  injury  to  that  of  the  upper  coals,  except  breaking 
them,  perhaps,  a  little.  In  many  instances,  indeed, 
by  this  operation  on  a  lower  coal,  upper  coals  are 
rendered  more  easily  worked. 

When  the  operation  is  commenced  by  working  on 
the  Shropshire  plan,  the  dip-head  levels  are  driven  in 
the  usual  manner,  and  very  large  bottom  pillars  are 
formed,  as  represented  in  fig.  1101.   Along  the  rise 
side  of  the  dip-head  level,  chains  of  wall,  or  long  pil- 
lars, are  also  made,  from  8  to  10  yards  in  breadth,  and 
only  mined  through  occasionally,  for  the  sake  of  ven- 
tilation, or  of  forming  new  roads.    In  other  cases  no 
a  pillars  are  left  upon  the  rise  side  of  the  level ;   but, 
instead  of  them^  buildings  of  stone  are  reared,  4  feet  broad  at  the  base,  and  9  or  10  feet 
from  the  dip  side  of  the  level.     Though  the  roads  are  made  9  feet  wide  at  first,  they 
are  reduced  to  half  that  width  after  the  full  pressure  of  the  strata  is  upon  them.     "When 
Vol.  II.  3  G 


1101 


!!!li 


H/.i\' 


M:.    i 

in-  :i; 


410 


PITCOAL. 


ever  these  points  are  secured.  tb2  operation  ol  cutting  away  the  whole  body  of  the  co»l 
begins.  The  place  where  the  coal  it  removed,  is  named  the  gobb  waste ;  and  gob- 
om,  or  gobb-stufl,  is  stones  or  rubbish  taken  away  from  the  coal,  pavement,  or  roof,  to 
fill  up  that  excavation  as  much  as  possible,  in  order  to  prevent  the  crush  of  superin- 
cumbent  strata  from  causing  heavy  falls,  or  following  the  workmen  too  fast  in  their 
descent.  Coals  mined  in  this  manner  work  most  easily  according  to  the  wav  in  which 
the  widest  backs  and  cutters  are;  and  therefore,  in  the  Shropshire  mode,' the  walls 
stand  sometimes  m  one  direction,  and  sometimes  in  another ;  the  mine  always  turning 
out  the  best  coals  when  the  open  backs  and  cutters  face  the  workmen.  As  roads  must 
be  maintained  through  the  crushed  strata,  the  miners  in  the  first  place  cut  awav  about 
15  feet  of  coal  round  the  pit-bottom  piUars,  and  along  the  upper  sides  of  the  dip-head 
chain  walls;  and  then,  at  the  distance  of  9  or  10  feet,  carry  regular  buUdings  of  stone 
3  feet  broad,  with  props  set  flush  with  the  faces  of  these,  if  necessary.  As  the  miners 
advance,  they  erect  small  pillars  of  roof  or  pavement  stone  in  regular  lines  with  the  wall 
face,  and  sometimes  with  props  intermediate. 

There  are  two  principal  modifications  of  the  Shropshire  plan.  The  first,  or  the  original 
system,  was  to  open  out  the  wall  round  the  pit-bottom ;  and,  as  the  wall  face*  extended, 
to  set  ort  mam  roads  and  brandies,  very  like  the  branches  of  a  tree.  These  roads  were 
so  distributed,  that  between  the  ends  of  any  two  branches  there  should  be  a  distance  of  30 
or  40  yards,  as  might  be  most  convenient.  (Seeyig.  1101.)  Each  space  of  coal  betwixt  the 
roads  is  called  a  wall ;  and  one  half  of  the  coals  produced  from  each  wall  is  carried  to  the 
one  road,  and  the  other  half  to  the  other  road.  This  is  a  great  convenience  when  the 
roof  IS  bad  ;  and  hence  a  distance  of  only  20  yards  betwixt  the  roads  is  in  many  instances 
preferred.  In  fig.  1101  a  represents  the  shaft ;  b  b,  the  wall-face ;  a,  the  dip-head  level  • 
6,  the  roads,  from  20  to  40  yards  asunder;  c,  the  gobb  or  waste,  with  buildings  along  the 
sides  of  the  roads ;  and  rf,  the  pillars. 

The  other  Shropshire  system  is  represented  in  Jig.  1102  where  a  shows  the  pit,  with 
the  bottom  pillars ;  b,  the  dip-head  levels ;  c,  the  off-break  from  the  level,  where  no 

pillars  are  left ;  rf,  the  off-break,  where  pillars  re- 
main to  secure  the  level.  All  roads  are  protected 
in  the  sides  by  stone  buildings,  if  they  can  be  had, 
laid  off  9  feet  wide.  After  the  crush  settles,  the 
roads  generally  remain  permanently  good,  and  can, 
in  many  cases,  be  travelled  through  as  easily  50  years 

.  u    r  ^u ■ ^^^^  they  have  been  made,  as  at  the  first.     Should 

stones  not  be  %ihcoming  coals  must  be  substituted,  which  are  built  about  20  inches 
m  the  base.  In  this  method,  the  roads  are  likewise  from  20  to  40  yards  apart ;  but 
instead  of  ramifying,  they  are  arranged  parallel  to  each  other.  The  miners  secure  the 
vasle  by  gobbing  ;  and  three  rows  of  props  are  carried  forwards  next  the  wall  faces  a, 
with  pillars  of  stone  or  of  coal  reared  betwixt  them.  This  mode  has  a  more  regular 
appnarance  than  the  other ;  though  it  is  not  so  generally  practised. 

In  the  post  and  stall  system,  each  man  has  his  own  room,  and  performs  all  the  labor 
of  It ;  but  in  that  of  Shropshire,  there  is  a  division  of  labor  among  the  workmen,  who 
t^!  S.V  1^  f^^  u\  '^'^^  companies.  The  first  set  curves  or  pools  the  coal  klong 
the  whole  lineof  walls  laying  m  or  pooling  at  least  3  feet,  and  frequently  45  inches! 
or  D  quarters,  as  it  is  called  These  men  are  named  holers.  As  the  crush  is  constantly 
following  them,  and  impending  over  their  heads,  causing  frequent  falls  of  coal,  they 
plant  props  of  wood  for  their  protection  at  regular  distances  lu  an  oblique  direction 
between  the  pavement  and  wall  face.  Indeed,  as  a  further  precaution,  staples  of  coaL 
about  10  inches  square  are  left  at  every  6  or  8  yards,  till  the  line  of  holing  or  curving 
IS  completed.  The  walls  are  then  marked  off  into  spaces  of  from  6  to  8  yards  in  length! 
and  at  each  space  a  shearing  or  vertical  cut  is  made,  as  deep  as  the  holingi  and  when 

^u^L      Th  ^^""^'  '"'"'l^-  ''  ^"^^^^^-     The  set  who  succeed  the  holers,  are  called 

nn  Z*  1^  f  ^'"ence  their  operations  at  the  centre  of  the  wall  divisions,  and  drive 
out  the  gibbs  and  staples  They  next  set  wedges  along  the  roof,  and  bring  down  pro- 
^essively  each  div^on  of  coal;  or,  if  the  roof  be  hard-bound,  the  coal  is  blown  down 

Toln^T  .?hh.  ^^' t  ^^1^°"^,^^^  »  ?««d  Parting,  the  coals  frequently  fall  down  tTie 
moment  the  g.bbs  are  struck;  which  makes  the  work  very  easy.     The  getters  are  re- 

iT/oe^nV^nrnnT'^^'*'''^'!^  set,  named  butty-men,  who  break  down  The  coaJslnTo 
LT  h/lliT  Tl"""  ''f'''?  "P  '^^  ^^^'  «"^  ^^^^  ^»^a^?e  «f  turning  out  the  coal 
SZ-  fil7^  i  ?h'  kk'  ^"f'u^  '^^  '''^^''  ^^'''  »>^'"^  done: they  build  up  the  stone 
pilars,  fill  up  the  gobb  set  the  trees,  clear  the  wall  faces  of  all  obstructions,  set  the 
gibbs  and  make  every  thing  clear  and  open  for  the  holers  to  resume  their  work.  If 
luJlu  to  be  heightened  by  taking  down  the  roof,  or  removing  the  pavement, 
these  butty-men  do  this  work  also,  building  forwards  the  sides  of  the  roads,  and  sccu! 
nng  them  with  the  requisite  props.  When  a  coal  has  a  following  or  roof  stine,  which 
regularly  separates  with  the  coal,  this  facilitates  the  Kbor,  and  saves  much  of  the  co^l  • 


PITCOAL. 


411 


and  should  a  soft  bed  of  fire-clay  occur  a  foot  or  two  beneath  the  coal-seam,  the  holing 
is  made  in  it,  instead  of  into  the  coal,  and  the  stone  betwixt  the  holing  and  the  coa 
benched  down,  which  serves  for  pillars  and  gobbing.    In  this  way  all  the  vendible  coa. 
becomes  available. 

Another  form  of  the  Shropshire  system  is,  for  each  miner  to  have  from  6  to  12  leet  ol 
coal  before  him,  with   a  leading-hand  man  ;  and  for  the  several  workmen  to  follow  in 
succession,  like  the  steps  of  a  stair.     When  the  coal  has  open  backs  and  cullers,  this 
work  "oes  on  veiy  regularly,  as  represented  in  Jig.  1103  where  the  leading  miner  is  at  a 
"  next  to  the  outcrop,  and  6  6,  &c.  are  the  wall  faces  of  each 

workman  ;  A  being  the  shaft,  and  b  the  dip-head  level. 
In  this  case  the  roads  are  carried  either  progressively 
through  the  gobb,  or  the  gobb  is  entirely  shut  up ;  and 
the  whole  of  the  coals  are  brought  down  the  wall-faces, 
either  to  the  dip-head  level  or  the  road  c,  c.  This  method 
may  be  varied  by  making  the  walls  broad  enough  to 
hold  two,  three,  or  four  men  when  each  set  of  miners 
performs  the  whole  work  of  holing,  getting,  breaking  down, 
and  carrying  off  the  coals. 

It  is  estimated  that  from  one  eighth  to  one  twelfth  part 
only  of  the  coals  remains  under  ground  by  the  Shropshire  plan;  nay,  in  favorable  circuna- 
stances,  almost  every  inch  of  coal  may  be  taken  out,  as  its  principle  is  to  leave  no  solid 
pillars  nor  any  coal  below,  except  what  may  be  indispensable  for  securing  the  gobb.  In- 
deed, this  system  might  be  applied  to  coal-seams  of  almost  any  ordinary  thickness,  provi- 
ding stuff  to  fill  up  the  gobb  could  be  conveniently  procured. 

In  Great  Britain,  seams  of  coal  are  mined  when  they  are  only  18  inches  thick ;  but  if 
thinner,  the  working  of  fire-clay  or  ironstone  immediately  adjoining  must  be  included.  A 
few  instances  may  be  adduced,  indeed,  where  caking  coals  of  a  fine  quality  for  blacksmiths 
have  been  worked,  though  only  in  12-inch  seams. 

Eighteen-inch  seams  are  best  worked  by  young  lads  and  boys.  The  coal  itself  may 
be  mined  without  lifting  the  pavement,  or  taking  down  the  roof  in  the  rooms ;  but 
roads  must  be  cut  either  in  the  pavement  or  the  roof,  for  removing  the  coals  to  the  pit- 
bottom.  All  coals  less  than  2  feet  3  inches  thick,  are  worked  with  the  view  of  taking 
out  all  the  coal,  either  on  the  Shropshire  system,  or  with  pillar-walls  and  rooms ;  with 
this  peculiarity,  that,  on  account  of  the  thinness  of  the  seam,  the  rooms  are  worked  as 
wide  as  the  roof  will  bear  up ;  or  if  a  following  of  the  roof-stone,  or  fall  of  it,  can  be 
brought  on,  it  proves  advantageous,  by  not  only  giving  head-room,  but  by  filling  up  the 
waste,  and  rendering  the  roads  easily  kept  for  the  working  of  the  pillars.  Where  no  fol- 
lowing  takes  place,  small  temporary  pillars,  about  8  feet  square,  are  left  along  the  chain- 
wall  side.  The  walls  may  vary  in  thickness  from  4  to  16  yards,  according  to  circumstan- 
ces, and  they  are  holed  through  only  for  ventilation. 

Coals  from  5  to  8  feet  thick  are  the  best  suited  in  every  point  of  view  for  the  effec- 
tive work  of  the  miner,  and  for  the  general  economy  of  underground  operations.  Whea 
they  exceed  that  thickness,  they  require  very  excellent  roof»  and  pavements,  to  render 
the  working  either  safe  or  comfortable ;  or  to  enable  those  who  superintend  the  field 
to  get  out  a  fair  proportion  of  coal  from  a  given  area.  In  such  powerful  beds  the 
Shropshire  method  is  impracticable,  from  want  of  gobbin ;  and  long  props,  unless  of 
prodigious  girth,  would  present  an  inadequate  resistance  to  the  pressure  of  the  massive 

ceiling. 

When  coals  do  not  exceed  20  feet  in  thickness,  and  have  good  roofs,  they  are  some- 
times worked  as  one  bed  of  coal ;  but  if  the  coal  be  tender  or  free,  it  is  worked  as  two 
beds.  One  half  of  such  thick  coal,  however,  is  in  general  lost  in  pillars ;  and  it  is  very 
seldom  that  less  than  one  third  can  be  left.  When  the  coal  is  free  and  ready  to  crumble 
by  the  incumbent  pressure,  as  well  as  by  the  action  of  the  air,  the  upper  portion  of  the 
coal  is  first  worked,  then  a  scaffolding  of  coal  is  left,  2  or  3  feet  thick,  according  to  the 
ccmpactncss  of  the  coal ;  and  the  lower  part  of  the  coal  is  now  worked,  as  shown  in 
llu4  Jig,  1104.  As  soon  as  the  workings  are  completed  to  the  proposed 

extent,  the  coal  scaftoldinars  are  worked  away,  and  as  much  of  the 


^     pillars  as  can  be  removed  with  safety.     As  propwood  is  of  no  use  in 

^.v.,.v. c--,-.^     coal-seams  of  such  a  height,  and  as  falls  from  the  roof  would  prove 

frequently  fatal  to  the  miners,  it  is  customary  with  tender  roofs  to  leave  a  ceiling  of 
coal  from  2  to  3  feet  thick.  This  makes  ar  excellent  roof;  and  should  it  break,  gives 
Warning  beforehand,  by  a  peculiar  crackling  noise,  very  different  from  that  of  roof-stones 
crushing  down. 

One  of  the  thickest  coals  in  Great  Britain,  worked  as  one  bed  from  roof  to  pavement, 
is  the  very  remarkable  seam  near  the  town  of  Dudley,  known  by  the  name  of  the  ten- 
yard  coal,  about  7  miles  long,  and  4  broad.  No  similar  coal  has  been  found  in  the 
island ;  and  the  mode  of  working  it  is  quite  peculiar,  being  a  species  of  panel  work 


i 


412 


PITCOAL. 


PITCOAL. 


413 


I 


*■ 


totally  different  from  the  modern  Newcastle  system.    A  compartment  or  panel  fbrm«l 
m  working  the  coal,  is  called  a  side  of  work     and  as  the  STn^rrtion  is^xhibU^ 

one  of  them  before  descnbing  the  whole  extent  of  the  workings  of  a  mine. 

Let/f7. 1105  represent  a  side  of  work  ;  a,  the  ribs  or  walls  of  coal  left  standing  roiinrl 
constuuung  the  side  of  work;  a,  the  pillars,  8  yards  square;  c,  the  stat/ll^^^^^^^ 

ll"»  dy}ne  cross-openings,  or  through  puts,  also  11  yards 

wide;  c,  the  bolt-hole,  cut  through  the  rib  from  the 
mam  road,  by  which  bolt-hole  the  side  of  work  is 
opened  up,  and  all  the  coals  removed.  Two,  three, 
or  even  four  bolt-holes  open  into  a  side  of  work,  ac- 
cording to  its  extent ;  they  are  about  8  feet  wide,  and 
9  feet  high.  The  working  is  in  a  great  measure  regu- 
lated by  the  natural  fissures  and  joints  of  the  coal- 
seam ;  and  though  it  is  30  feet  thick,  the  lower  band, 
of  2  feet  3  inches,  is  worked  first ;  the  miners  choosing 
to  confine  themselves  within  this  narrow  opening,  in 
order  to  gain  the  greater  advantage  afterwarxls,  in 
working  the  superjacent  coal.  Whenever  the  bolt 
hole  IS  cut  through,  the  work  is  opened  up  by  diivinir 
a  gallery  forward,  4  feet  wide,  as  shown  by  the  dotted 
lines.  At  the  sides  of  this  gallery  next  the  bolt-hole, 
♦«,^        J    u      J  ^  ^  ,  ^^^'^  miner  breaks  off  in  succession  a  breast  of  coal 

two  yards  broad,  as  at  /,/,  by  means  of  which  the  sides  of  the  rib-walls  a  are  forrn^' 
and  the  area  of  the  pillars.  In  this  way  each  collier  follows  anoth^  as  in  onP  of  thi 
systems  of  the  Shropshire  plan.  When  the  side  of  work  LZ!d  open  aling  the  rib-wa  Is 
and  the  faces  and  sides  of  the  pillars  have  been  formed,  the  upper  coals  arrthenbe4n 
to  be  worked,  next  the  nb-wall.  This  is  done  by  shearing  up  to  a  bed  next  the  bolt  ho  e 
and  on  each  side,  whereby  the  head  coals  are  brought  regSlarly  d^n  fn  toe  cuS 
Tu"'  fr^  ^'^p  "^'^  r  ^"!!!  ^^^^  ^^^  ^'''  P*^^^?«  of  subiJdinTte  diSs  of  the 
X^^lX^etuZZti:^:'  ^^^"  ^"^^  ^^"-^'-«  ^^-^  ^^  convenient' t^ 

the  coal      Hence,  from  four  tenths  to  a  half  of  the  total  amount  is  lost  fi?  ever       " 

Another  method  of  working  coal  of  uncommon  thickness  is  by  scafibldin-s  ir  sta-et 
of  coals,  as  practised  m  the  great  coal  bed  at  Johnstone,  near  Paisley,  of  whFch  a  sectbi 
has  already  been  given.    In  one  part  of  the  field  the  coal  is  from  50  to  60  feet  tS 

uoT  '\  ^"'''""''    n  ^^  ^'"f;    "^^^  '"^"^  °^  ^'^^^  interspersed  through  the    ^ 

1 10b         coal  are  generally  inconsiderable,  and  amount  in  only  two  cases  to  27  inches 
in  thickness.     The  roof  of  the  coal  is  so  unsound,  and  the  height  so  pro! 

t^T^J  ?*'  *'  ^'V""^'*  J^""}  P^^'^'y  ^^  ^'^'^^^  »n  o"e  seam,  like  that  of 
Staffordshire.  About  3  feet  of  the  upper  coal  is  therefore  left  as  a  roof 
under  which  a  band  of  coal,  from  6  to  7  feet  thick,  is  worked  on  the  pS 
and  stall  plan,  with  square  pillars  of  extra  strength,  which  are  thereafter 
penetrated.  A  p  atform  about  3  feet  high  is  left  at  the  sole ;  under  which 
the  rooms  and  pillars  are  set  off  and  worked  in  another  portion  of  the  coah 
from  D  to  7  feet  thick,  great  care  being  had  to  place  pillar  under  pillar.  an<f 

nf  li«  ^h"  fn  P*''*l^'«"'.^  P'-^^e«t  a  crush.  Where  the  coal  is  thickest, 
no  less  than  10  bands  of  it  are  worked  in  this  way,  as  is  shown  in  fi/r.  1106 
When  any  band  of  the  coal  is  foul  from  sulphur  or  other  causes,  it  is  left 
Zf}  I  u-""^  P>l<^™»/«  that  a  large  proportion  of  it  is  lost,  as  in  the 
*  K  .  •  r  .Staffordshire  mines.  Much  attention  must  here  be  paid  to  the  vertical  dis- 
tribulion  of  the  pil  ars  and  apartments ;  the  miner's  compass  must  be  continually  con^ 
sulcd  and  bore-holes  must  be  put  down  through  the  coal  scaffoldings,  to  re^ 
rectly  the  position  of  the  pillars  under  one  another.  fe^uiaie  cor- 

Edge  coals,  which  are  nearly  perpendicular,  are  worked  in  a  peculiar  manner;  for  the 
collier  stands  upon  the  coal  having  the  roof  on  the  one  hand,  and  the  floor  on  the  oJher! 
__-  ^    i  aJ  a  .         llff /7  vertical  walls.    The  engine-pit  is  sunk  in  the  most  pow! 
'■"■-^-^^^■■-'■""'■""     ^'^^^  ^t'-al"'"-    In  some  instances  the  same  stratum  is  so  vertical 

is  to  be  sunk  through  for  the  whole  depth  of  the  shaft. 
\N  henever  the  shaft  has  descended  to  the  required  depth,  galle- 
,™«  ,=™;s*        ■'?  '"'■^,^7^-^  ?<=^«ss  the  strata  from  its  bottom,  till  the  coals  are 

MDlQllll     I'JTr.  .  %k'  ''  '•''"'".  ^"  ^^'  ^^^^  ^^^^^  ^^  «^«  '^^  edge-coal, 
iuimi  Limmi/i.     a  a,  «;  a,  the  engine-pit;  6,  6,  the  transverse  galleries  from  the 


1 

♦ 

1 

^j 

1^^^ 

^^ 

^ 

h^^^^i 

^ 

i 

^fc 

1 

i 

^K 

J 

^ 

^^^^^ 

'^ 

^ 

^^tt^ 

^ 

p 

^^t 

s 

^ 

L^^gL^ 

P5^ 

^ 

■^^ 

B«U 

bottom  of  the  Shaft  ;  and  c,  c,  upper  transverse ' gaYleVl^r^Mk;' ^^;;te;"c;n^^^^^^ 

The  principal  edge  coal  works  in  Great  Britain  lie  in  the  neigh 


working 


the  coal. 


borhood  of  Edinburgh,  and  the  coals  are  carried  on  the  backs  of  women  from  the  wall, 
face  to  the  bottom  of  the  engine-pit. 

The  modes  of  carrying  coals  from  the  point  where  they  are  excavated  to  the  pit  bottom 
are  nearly  as  diversified  as  the  systems  of  working. 

One  method  employs  hutches,  or  baskets,  having  slips  or  cradle  feet  shod  with  iron, 
containing  from  2  to  3  hundred  weight  of  coals.  These  baskets  are  dragged  along  the 
floor  by  ropes  or  leather  harness  attached  to  the  shoulders  of  the  workmen,  who  are  either 
the  colliers  or  persons  hired  on  purpose.  This  method  is  used  in  several  small  collieries; 
but  it  is  extremely  injudicious,  exercising  the  muscular  action  of  a  man  in  the  most  un- 
profitable manner.  Instead  of  men,  horses  are  sometimes  yoked  to  these  basket-hurdles, 
which  are  then  made  to  contain  from  4  to  6  hundred  weight  of  coals ;  but  from  the  mag- 
nitude of  the  friction,  this  plan  cannot  be  commended. 

An  improvement  on  this  system,  where  men  draw  the  coals,  is  to  place  the  basket  or 
corve  on  a  small  four-wheeled  carriage,  called  a  tram,  or  to  attach  wheels  to  the  corve 
itself.  Thus  much  more  work  is  performed,  provided  the  floor  be  hard ;  but  not  on  a  soft 
pavement,  unless  some  kind  of  wooden  railway  be  laid. 

The  transport  of  coals  from  the  wall-face  to  the  bottom  of  the  shaft  was  greatly 
facilitated  by  the  introduction  of  cast-iron  railways,  in  place  of  wooden  roads,  first 
brought  into  practice  by  Mr.  John  Curr  of  Sheffield.  The  rails  are  called  tram-rails, 
or  plate-rails,  consisting  of  a  plate  from  3  to  4  inches  broad,  with  an  edge  at  right  angles 
to  it  about  two  inches  and  a  half  high.  Each  rail  is  from  3  to  4  feet  long,  and  is  fixed 
either  to  cross  bearers  of  iron,  called  sleepers,  or  more  usually  to  wooden  bearers.  In 
some  collieries,  the  miners,  after  working  out  the  coals,  drag  them  along  these  railways 
to  the  pit  bottom ;  but  in  others,  two  persons  called  trammers  are  employed  to  transport 
the  coals ;  the  one  of  whom,  in  front  of  the  corve,  draws  with  harness  ;  and  the  other, 
called  the  palter,  pushes  behind.  The  instant  each  corve  arrives,  from  the  wall-face,  at 
a  central  spot  in  the  system  of  the  railways,  it  is  lifted  from  the  tram  by  a  crane  placed 
there,  and  placed  on  a  carriage  called  a  roUey,  which  generally  holds  two  corves. 
Whenever  three  or  four  rolleys  are  loaded,  they  are  hooked  together,  and  the  rolley  driver, 
1108  with  his  horse,  takes  them  to  the  bottom  of  the  engine-shaft.    The  rolley 

O  horses  have  a  peculiar  kind  of  shafts,  commonly  made  of  iron,  named 
«  limbers,  the  purpose  of  which  is  to  prevent  the  carriage  from  overrunning 
them.  One  of  these  shafts  is  represented  in^g.  1108.  The  hole  shown 
at  a  passes  over  an  iron  peg  or  stud  in  front  of  the  rolley,  so  that  the  horse  may  be 
quickly  attached  or  disengaged.  By  these  arrangements  the  work  is  carried  on  with 
surprising  regularity  and  despatch. 

The  power  of  the  engine  for  drawing  the  coals  up  the  shaft  is  made  proportional  to 
the  depth  of  the  pit  and  the  quantity  to  be  raised,  the  corves  ascending  at  an  average 
velocity  of  about  12  feet  per  second.  So  admirable  is  the  modern  arrangement  of  this 
operation,  that  the  corves  are  transported  from  the  wall-faces  to  the  pit  bottom,  and 
moved  up  the  shaft,  as  fast  as  the  onsetters  at  the  bottom,  and  the  banksmen  at  the  top, 
can  hook  the  loaded  and  empty  corves  on  and  off  the  engine  ropes.  Thus  100  corves  of 
coals  have  been  raised  every  hour  up  a  shaft  100  fathoms  deep,  constituting  a  lift  of  27 
tons  per  hour,  or  324  tons  in  a  day,  or  shift  of  12  hours.  Coals  mined  in  large  cubical 
masses  cannot,  however,  be  so  rapidly  raised  as  the  smaller  coal  of  the  Newcastle 
district. 

When  coals  have  so  great  a  rise  from  the  pit  bottom  to  the  crop  that  horses  cannot  be 
used  on  ilie  rolley  ways,  the  corves  descend  along  the  tram-roads,  by  means  of  inclined- 
plane  machines,  which  are  moved  either  by  vertical  rope-barrels,  or  horizontal  rope- 
sheaves.  These  inclined  planes  are  frequently  divided  into  successive  stages,  200  or  300 
yards  long,  at  the  end  of  each  of  which  is  an  inclined-plane  machine,  whereby  the  coaU 
are  lowered  from  one  level  to  another. 

The  wheels  of  the  trams  and  rolleys  vary  in  diameter  from  8  to  16  inches,  according 
to  the  thickness  of  the  coal.  In  some,  the  axles  not  only  revolve  on  their  journals,  but 
the  wheels  also  revolve  on  their  axles. 

Various  forms  of  machines  have  been  employed  for  raising  the  coals  out  of  the  pits. 
The  steam  engine  with  fly-wheel  and  rope-barrels  is,  however,  now  preferred  in  all  con- 
siderable establishments.  When  of  small  power,  they  are  usually  constructed  with  a  fly 
wheel,  and  short  fly-wheel  shaft,  on  which  there  is  a  small  pinion  working  into  the 
teeth  of  a  large  wheel,  fixed  upon  the  rope-barrel.  Thus  the  engine  may  move  with 
great  rapidity,  while  it  imparts  an  equable  slow  motion  to  the  corves  ascending  in  the 
shaft.  When  the  engines  are  of  great  power,  however,  they  are  directly  connected  with 
the  rope-barrel ;  some  of  these  being  of  such  dimensions,  that  each  revolution  of  the  rope- 
barrel  produces  an  elevation  of  12  yards  in  the  corve.  A  powerful  brake  is  usually  con- 
nected with  the  circumference  of  the  fly-wheel  or  rope-barrel,  whereby  the  brakeman, 
by  applying  his  foot  to  the  governing  lever  of  the  brake,  and  by  shutting  at  the  same 
time  the  steam  valves  with  his  hands,  can  arrest  the  corve,  or  pitch  its  arrival  withm  a 


■  i . 


414 


PITCOAL. 


PITCOAL. 


416 


I 


II 


# 


fhTh'?.  ?  ?^  required  height  of  every  delivery.  An  endlesg  chain,  suspended  from 
the  bottom  to  the  top  of  the  shaft,  has,  in  a  few  pits  of  moderate  depth,  been  worked  by 
fnnnTh.fhl!;"^'  Tor  raising  corves  m  constant  succession  j  but  the  practice  has  not  beei 
found  hitherto  applicable  on  the  greater  scale. 

r^J.y^l'ifJl!^^'"'*  of  water  engines  for  raising  coals,  strictly  admissible  only  in  level  free 
whh  w.tPr  wT'V^  '^'  load^  cor^^e  is  produced  by  the  descent  of  a  cassoon  fiUed 
ThTnlfrl  ^  r  ^^  ^^^""^  ^'^^  '^^''^^"^  ^""^  ^•^'■""^^  «q»al  spaces,  the  rope  barrels  for 
coairhTvrtoh  the  corves  are  of  equal  diameter;  but  when  the  point  frL  which  the 
coals  have  to  be  lifted  is  deeper  than  the  point  of  discharge  for  the  water  into  the  dry 
level,  the  cassoon  must  be  larger,  and  the  ro|>e  barrel  smaller ;  so  that  by  the  time  the 
al^fuZr"^"'  '°  ^\"  half-depth,  for  example,  the  corve  ma^  have  mounted  through 
double  the  space.  The  cassoon  is  filled  with  water  at  the  pit  mouth,  and  is  emptied  by  a 
Belf-actmg  valve  whenever  it  gets  to  the  bottom.  The  loaded  corve  is  replaced  by  an 
emp  y  one  at  the  pit  mouth,  and  its  weight,  with  that  of  the  descending  rope,  pull  up  the 
empty  cassoon ;  the  motions  of  the  whole  mechanism  being  regulated  b>'  a  powerful 

Various  plans  have  been  devised  to  prevent  collision  between  the  ascending  and  de- 
scendmg  corves,  which  sometimes  pass  each  other  with  a  joint  velocity  of  20  or  30  feet 
per  second.  One  method  is  by  dividing  the  pit  from  top  to  bottom,  so  that  each  corve 
SlTiJ*^-*  separate  compartment.  Another  mode  was  invented  by  Mr.  Curr  of 
bhetfield  in  which  wooden  guides  were  attached  from  top  to  bottom  of  the  pit :  bein*' 
spars  of  deal  about  4  inches  square,  attached  perpendicularly  to  the  sides  of  the  shaft' 
and  to  buntons  m  the  middle  of  the  pit.  Betwixt  these  guides,  friction-roUer  sliders  are 
placed  attached  to  the  gin -ropes,  to  which  sliders  the  corves  are  suspended.  In  this 
1^^:!  l^'V^^  ?r  ^  '■^''^  u'''^*^  ^^^^  rapidity;   but  there  is  a  considerable  loss  of 

3      TM     f    !'\-°.Tk^  ^'^r^^/*  r*'^^'  "^^^'^  shutters  or  sliding  boards  must>be 
us«I.     This  plan  is  highly  beneficial  where  the  coals  are  in  large  lumps. 

Both  ropes  and  chains  are  used  for  lifting  coals.     The  round  ropes  are  shroud-laid ; 

thi  i' P'f  "^^f  L^^V  ^^^  ?*'  ^^I"^'  '"^^^  «^  ^«"^  '^^'  Pla««l  horizontally  together 
the  ropes  bemg  laid  alternately  right  and  left.  In  this  way,  the  ropes  counteract  one 
another  in  the  twist,  hanging  like  a  riband  down  the  shaft;  and  are  stitched  s?rong^y 
together  by  a  small  cord.  Such  rope  bands  are  not  only  very  pliable  for  their  streneTh 
which  protects  the  heart  of  the  rope  from  breaking,  but  as  they  lap  upon  themselve!  a 
St  ,hr  T''  ?."  y«P«-^^-^i-  They  possess  the  additional  ad^antge,  Thaby^S 
nP^n^Sn  ^U  ''i/^^  "^'^Tl'  ""^  '^^  ^^  ^"  ^^'^*^  ^^^^  ^«"'  ^"^  thus  make  a  Im- 
Th^..  rrn^^"''-^  t^-'"'^  ^\'  increasing  length  of  rope  descending  with  its  corve. 

are'^oTtlf  utl'^SeTcAB^K.'^  "'"'  '^^  '''  "^^  '''"^  ^""'^  ^'^  ^^^^*  P«dding-link  chain, 

.n^^^ii^'ll"'  ^"^'  ^^'r  "  ^t^'i^^  '*''  ^^"^^*^  «^  *^«  pit  °»«"th»  are  drawn  to  the  bin  or 
^nl     t    Ik^'m^*""  '^P'  ^^  ^?'"'^''  °"  ^y  trammers  on  a  tram-road.     But  with  small 
TVr!V^^^X^'^''^h^^^  ^'  ^"^^  i^  '^'''^  8  or  9  feet  above  the  commoT lev'Tof 
the  ground,  and  the  coal-heap  slopes  downwards  from  that  height.    As  the  bins  increase 
tram-roads  are  laid  outwards  upon  them.  ^a  i  ic  uius  increase, 

n„L?!nnniT  "^T"'^^  •  ^^  Ventilation  of  coal  mines.  Into  their  furthest  recesses,  an  ade- 
t^^onTI-  '  %''^  J!'  """''  ^^  '^'""^  forwards,  for  the  purposes  of  respiration,  and 
the  combustion  of  candles;  as  also  for  clearing  ofl*  the  carbonic  acid  and  cal-bureted  hy- 
drogen  gases  so  destructive  to  the  miners,  who  caU  these  noxious  airs,  from  their  mcwt 
obvious  qualities,  choke-damp  and  fire-damp. 

of ^thpTn«?^h!fr  ^"^Z'''  "^^^  ^PP]^^^  ^°  ^^^  ^^^"^^^  °^  the  t^^es,  and  the  extraction 
^LnLfpH  in  .hT^T'^J""  ^^'^  ^^  '"^h  "'"ited  extent,  that  when  inflammable  air  ac- 
cumulated  m  the  foreheads,  it  was  usual  in  many  coUieries  to  fire  it  every  morninff 
This  was  done  by  fixing  a  lighted  candle  to  the  end  of  a  lone  pole,  which  bein<^  extendS 

safely  over  him.    If  the  gas  was  abundant,  the  explosive  miner  pu  on  a  wet  jacket  to 
prevent  the  fire  from  scorching  him.    In  other  situations,  where  the  fire-dimp  was  stffl 

ZpndTfT:  fX^""^^r\'^^"^^"  ^^^^^^'^^  i"to  it,  by 'a  cord  passing  oveTaTa tch  S 
the  end  of  the  gallery,  while  the  operator  stood  at  a  distance.     This  very  rude  and  dan- 

fhTn-am^^f^S^efitr'/rnl  '^'  ^^^^^  ^-^^^  ^  ^  ^^  -i-^-^er 

The  carbonic  acid  or  choke-damp,  having  a  greater  specific  gravity  than  atmospheric 
air,  m  the  proportion  of  about  3  to  2,  occupies  the  lower  part  of  the  workings,  and 
gives  comparatively  ittle  annoyance.  Its  presence  may  moreover  be  alwavs  ife"v 
ascerJamed  by  the  lighted  candle.  This  cannot,  however,  be  said  of  the  fi7e-d1mp! 
which  being  lighter  and  more  moveable,  diffuses  readily  through  the  atmospheric  2rS 
as  to  form  a  most  dangerous  explosive  mixture,  even  at  a  considerable  distance  from 


1109 


the  blowers  or  sources  of  its  extrication  from  the  coal  strata.  Pure  subcarbureted  hy. 
drogen  has  a  specific  gravity  =  0*555,  air  being  1 ;  and  consists  of  a  volume  of  vapor  of 
carbon,  and  two  volumes  of  hydrogen,  condensed  by  mutual  affinity  into  one  volume. 
The  chok^-damp  is  a  mixture  of  the  above,  with  a  little  carbonic  acid  gas,  and  variable 
proportions  of  atmospheric  air.  As  the  pure  subcarbureted  hydrogen  requires  twice  its 
bulk  of  oxygen  to  consume  it  completely,  it  will  take  for  the  same  eflect  about  10  times 
its  bulk  of  atmospheric  air,  since  this  volume  of  air  contains  about  two  volumes  of  oxy- 
gen. Ten  volumes  of  air,  therefore,  mixed  with  one  volume  of  subcarbureted  hydrogen, 
form  the  most  powerfully  explosive  mixture.  If  either  less  or  more  air  be  intermixed, 
the  explosive  force  will  be  impaired ;  till  3  volumes  of  air  below  or  above  that  ratio,  con- 
stitute non-explosive  mixtures;  that  is,  1  of  the  pure  fire-damp  mixed  with  either  7  or  13 
(rf'air,  or  any  quantity  below  the  first,  or  above  the  second  number,  will  aflbi-d  an  unex- 
plosive  mixture.  With  the  first  proportion,  a  candle  will  not  burn  ;  with  the  second,  it 
burns  with  a  very  elongated  blue  flame.  The  fire-damp  should  therefore  be  still  further 
diluted  with  common  air,  considerably  beyond  the  above  proportion  of  1  to  13,  to  render 
the  working  of  the  mine  perfectly  safe. 

These  noxious  gases  are  disengaged  from  the  cutters,  fissures,  and  minute  pores  of  the 
coal ;  and  if  the  quantity  be  considerable,  relative  to  the  orifice,  a  hissing  noise  is  heard. 

Though  the  choke-damp,  or  carbonic  acid  gas,  be  invisible,  yet  its  line  of  division 
from  the  common  air  is  distinctly  observable  on  approaching  a  lighted  candle  to  the 

lower  level,  where  it  accumulates,  which  becomes  extinguished 
the  instant  it  comes  within  its  sphere,  as  if  it  were  plunged  in 
water.  The  stratum  of  carbonic  acid  sometimes  lies  1  or  2  feet 
thick  on  the  floor,  while  the  superincumbent  air  is  perfectly  good.  When  the  coal  has 
a  considerable  dip  and  rise,  the  choke-damp  will  be  found  occupying  the  lower  parts  of 
the  mine,  in  a  wedge  form,  as  represented  in  ^g.  1109  where  a  shows  the  place  of  the 
carbonic  acid  gas,  and  6  that  of  the  common  air. 

When  a  gallery  is  driven  in  advance  of  the  other  workings,  and  a  discharge  of  this  gas 
takes  place,  it  soon  fills  the  whole  mine,  if  its  direction  be  in  the  line  of  level,  and  the 
mine  is  rendered  unworkable  until  a  supply  of  fresh  air  is  introduced  to  dislodge  it.  As 
the  flame  of  a  candle  indicates  correctly  the  existence  of  the  choke-damp,  the  miners  may 
have  sufficient  warning  of  its  presence,  so  as  to  avoid  the  place  which  it  occupies,  till 
adequate  means  be  taken  to  drive  it  away. 

The  fire-damp  is  not  an  inmate  of  every  mine,  and  is  seldom  found,  indeed,  where 
the  carbonic  acid  prevails.  It  occurs  in  the  greatest  quantities  in  the  coal  mines  of  the 
counties  of  Northumberland,  Durham,  Cumberland,  Stafl'ordshire,  and  Shropshire.  It 
is  more  abundant  in  coals  of  the  caking  kind,  with  a  bright  steel-grained  fracture,  than 
in  cubic  coals  of  an  open-burning  quality.  Splint  coals  are  still  less  liable  to  disengage 
this  gas.  In  some  extensive  coal-fields  it  exists  copiously  on  one  range  of  the  line  of 
bearing,  while  on  the  other  range  none  of  it  is  observed,  but  abundance  of  carbonic 
acid  gas. 

In  the  numerous  collieries  in  the  Lothians,  south  from  the  city  of  Edinburgh,  the  fire 
damp  is  unknown  ;  while  in  the  coal-fields  round  the  city  of  Glasgow,  and  along  the  coasc 
of  Ayrshire,  it  /requenlly  appears. 

The  violent  discharge  of  the  gas  from  a  crevice  or  cutter  of  the  coal,  is  called  a  blower ; 
and  if  this  be  ignited,  it  burns  like  an  immense  blowpipe,  inflaming  the  coal  at  the  opposite 
side  of  the  gallery.  The  gas  evidently  exists  in  a  highly  compressed  and  elastic  state, 
whence  it  seems  to  loosen  the  texture  of  the  coals  replete  with  it,  and  renders  them  more 
easily  worked.  The  gas  is  often  peculiarly  abundant  near  a  great  dislocation  or  slip  of 
the  strata ;  so  that  the  fissure  d'  the  dislocation  will  sometimes  emit  a  copious  stream  of 
gas  for  many  years.  It  has  also  happened,  that  from  certain  coals,  newly  worked,  and 
let  fall  from  a  height  into  the  hold  of  a  vessel,  so  much  inflammable  gas  has  been  extri- 
cated that,  after  the  hatches  were  secured,  and  the  ship  ready  to  proceed  to  sea,  the  gas 
has  isnited  with  the  flame  of  a  candle,  so  as  to  scorch  the  seamen,  to  blow  up  the  decks, 
and  otherwise  damage  the  vessel.  In  like  manner,  when  the  pillars  in  a  mine  are 
crushed  by  sudden  pressure,  a  great  discharge  of  gas  ensues.  This  gas,  being  lighter 
than  common  air,  always  ascends  to  the  roof  or  to  the  rise  of  the  galleries ;  and,  where 
the  dip  is  considerable,  occupies  the  forehead  of  the  mine,  in  a  wedge  form,  as  shown  iu 
P^^^^  fig.  1110  where  a  represents  the  fire-damp,  and  b  the  common  air. 

1110  B^^^^°^  ^      In  this  case,  a  candle  will  burn  without  danger  near  the  point  c, 
"^     —  ''      close  to  the  floor ;    but  if  it  be  advanced  a  few  Jeet  further  to- 
wards the  roof,  an  explosion  will  immediately  ensue  ;    since  at  the  lin  .»  where  the  two 
elastic  fluids  are  in  contact,  they  mix,  and  form  an  explosive  body. 

When  this  gas  is  largely  diluted  with  air,  the  workmen  do  not  seem  t( 
venience  from  breathing  the  mixture  for  a  period  of  many  years ;  but  ( 
carbureted  hydrogen,  the  miner  instantly  drops  down  insf  nsible,  and,  if  >ot  speedily  re 
moved  into  fresh  air,  he  dies. 


feel 


any  incon- 
pure 


inhaling 


■■•^-f 


416 


PITCOAL. 


riTCOAL. 


417 


m 


The  production  of  these  noxious  gases  renders  ventilation  a  primary  object  in  tht 
system  of  mining.  The  most  easily  managed  is  the  carbonic  acid.  If  an  air-pipe  has 
been  carried  down  the  engine  pit  for  the  purpose  of  ventilation  in  the  sinking,  other  pipes 
are  connected  with  it,  and  laid  along  the  pavement,  or  are  attached  to  an  angle  of  the 
mine  next  the  roof.  These  pipes  are  prolonged  with  the  galleries,  by  which  means  the 
air  at  the  forehead  is  drawn  up  the  pipes  and  replaced  by  atmospheric  air,  which  descends 
by  the  shaft  in  an  equable  current,  regulated  by  the  draught  of  the  furnace  at  the  pit 
mouth.  This  circulation  is  continued  till  the  miners  cut  through  upon  the  second  sh^, 
when  the  air-pipes  become  superfluous ;  for  it  is  well  known  that  the  instant  such  com- 
munication is  made,  as  is  represented  in  Jig.  1111  the  air  spontaneously  descends  in  the 
engine  pit  a,  and,  passing  along  the  gallery  a,  ascends  in  a  steady  current  in  the  second 
nil  B        pit  B.     The  air,  in  sinking  through  A,  has  at  first  the  atmospheric 

temperature,  which  in  winter  may  be  at  or  under  the  freezing  point 
of  water ;  but  its  temperature  increases  in  passing  down  through 
the  relatively  warmer  earth,  and  ascends  in  the  shaft  b,  warmer 
than  the  atmosphere.  When  shaf\s  are  of  unequal  depths,  as 
represented  in  the  figure,  the  current  of  air  flows  pretty  uniformly 
in  one  direction.  If  the  second  shaft  has  the  same  depth  with  the  first,  and  the  bottom 
and  mouth  of  both  be  in  the  same  horizontal  plane,  the  air  would  sometimes  remain  at 
rest,  as  water  would  do  in  an  inverted  syphon,  and  at  other  times  would  circulate  down 
on,e  pit  and  up  another,  not  always  in  the  same  direction,  but  sometimes  up  the  one,  and 
sometimes  up  the  other,  according  to  the  variations  of  temperature  at  the  surface,  and 
the  barometrical  pressures,  as  modified  by  winds.  There  is  in  mines  a  proper  heat,  pro- 
portional to  their  depth,  increasing  about  one  degree  of  Fahrenheit's  scale  for  every  60 
feet  of  descent. 

There  is  a  simple  mode  of  conducting  air  from  the  pit  bottom  to  the  forehead  of  the 
mine,  by  cutting  a  ragglin,  or  trumpeting,  as  it  is  termed,  in  the  side  of  the  gallery  as  rep- 
1112  ^  presented  in  ^g.  1112,  where  a  exhibits  the  gallery  in  the  coal,  and  b  the 

^ — ^. ^fagglin,  which  is  from  15  to  18  inches  square.     The  coal  itself  forms 

three  sides  ot  the  air-pipe,  and  the  fourth  is  composed  of  thin  deals  applied  air-tisht,  and 
nailed  to  small  props  of  wood  fixed  between  the  top  and  bottom  of  the  lips  of  the  ragglin. 
This  mode  is  very  generally  adopted  in  running  galleries  of  communication,  and  dip-head 
level  galleries,  where  carbonic  acid  abounds,  or  when  from  the  stagnation  of  the  air  the 
miners'  lights  burn  dimly. 

When  the  ragglin  or  air-pipes  are  not  made  spontaneously  active,  the  air  is  sometimes 
impelled  through  them  by  means  of  ventilating  fanners,  having  their  tube  placed  at  the 
pit  bottom,  while  the  vanes  are  driven  with  great  velocity  by  a  wheel  and  pinion  worked 
with  the  hand.  In  other  cases,  large  bellows  like  those  of  the  blacksmith,  furnished  with 
a  wide  nozzle,  are  made  to  act  in  a  similar  way  with  the  fanners.  But  these  are  merely 
temporary  expedients  for  small  mines.  A  very  slight  circulation  of  air  can  be  effected 
by  propulsion,  in  comparison  of  what  may  be  done  by  exhaustion ;  and  hence  it  is  better 
to  attach  the  air-pipe  to  the  valve  of  the  bellows,  than  to  their  nozzle. 

Ventilation  of  collieries  has  been  likewise  effected  on  a  small  scale,  by  attaching  a 
horizontal  funnel  to  the  top  of  air-pipes  elevated  a  considerable  height  above  the  pit 
mfouth.  The  funnel  revolves  on  a  pivot,  and  by  its  tail-piece  places  its  mouth  so  as  to 
receive  the  wind.  At  other  times,  a  circulation  of  air  is  produced  by  placing  coal-fires 
in  iron  grates,  either  at  the  bottom  of  an  upcast  pit,  or  suspended  by  a  chain  a  few 
fathoms  down. 

Such  are  some  of  the  more  common  methods  practised  in  collieries  of  moderate 
depth,  where  carbonic  acid  abounds,  or  where  there  is  a  total  stagnation  of  air.  But 
in  all  great  coal  mines  the  aerial  circulation  is  regulated  and  directed  by  double 
doors,  called  main  or  bearing  doors.  These  are  true  air-valves,  which  intercept  a 
current  of  air  moving  in  one  direction  from  mixing  with  another  moving  in  a  dif- 
ferent direction.      Such  valves  are  placed  on  the  main  roads  and  passages  of  the 

galleries,  and  are  essential  to  a  just  ventilation.  Their  func- 
tions are  represented  in  the  annexed  ^g.  11 13,  where  a  shows 
the  downcast  shaft,  in  which  the  aerial  current  is  made  to 
descend;  b  is  the  upcast  shafl,  sunk  towards  the  rise  of  the 
coal ;  and  c,  the  dip-head  level.  Were  the  mine  here  figured 
to  be  worked  without  any  attention  to  the  circulation,  the  air 
would  flow  down  the  pit  a,  and  proceed  in  a  direct  line  up 
the  rise  mine  to  the  shaft  b,  in  which  it  would  ascend.  The  consequence  would  there- 
fore be,  that  all  the  galleries  and  boards  to  the  dip  of  the  pit  a,  and  those  lying  on  each 
fide  of  the  pits,  would  have  no  circulation  of  air;  or,  in  the  language  of  the  collier,  would 
be  laid  dead.  To  obviate  this  result,  double  doors  are  placed  in  three  of  the  galleries  ad- 
joining the  pit ;  viz.,  at  a  and  b,  c  and  d,  e  and/;  all  of  which  open  inwards  to  the  shaft  A. 
By  this  plan,  as  the  air  is  not  suffered  to  pass  directly  from  the  shaft  a  to  the  shaft  b,  through 


!  f  • 

i 


tiie  doors  a  and  6,  it  would  have  taken  the  next  shortest  direction  hy  e  d  and  e/;  but  the 
doors  in  these  galleries  prevent  this  course,  and  compel  it  to  proceed  downwards  to 
the  dip-head  level  c,  where  it  will  spread  or  divide,  one  portion  pursuing  a  route  tc 
the  right,  another  to  the  left.  On  arriving  at  the  boards  g  and  A,  it  would  have 
natui-ally  ascended  by  them ;  but  this  it  cannot  do,  by  reason  of  the  building  or  stop- 
ping placed  at  g  and  h.  By  means  of  such  stoppings  placed  in  the  boards  next  the 
dip-head  level,  the  air  can  be  transported  to  the  right  hand  or  to  the  left  for  many 
miles,  if  necessary,  providing  there  be  a  train  or  circle  of  aerial  communication  from 
the  pit  A  to  the  pit  b.  If  the  boards  t  and  k  are  open,  the  air  will  ascend  in  them, 
as  traced  out  by  the  arrows;  and  after  being  diflfused  through  the  workings,  will  again 
meet  in  a  body  at  a,  and  mount  the  gallery  to  the  pit  b,  sweeping  away  with  it  the 
deleterious  air  which  it  meets  in  its  path.  Without  double  doors  on  each  main  passage 
the  regular  circulation  of  the  air  would  be  constantly  liable  to  interruptions  and 
derangements;  thus,  suppose  the  door  c  to  be  removed,  and  only  d  to  remain  in  the 
left  hand  gallery,  all  the  other  doors  being  as  represented,  it  is  obvious,  that  whenevei 
the  door  d  is  opened,  the  air,  finding  a  more  direct  passage  in  that  direction,  would 
mount  by  the  nearest  channel  /,  to  the  shaft  b,  and  lay  dead  all  the  other  parts  of  the 
work,  stopping  all  circulation.  As  the  passages  on  which  the  doors  are  placed  con- 
stitute the  main  roads  by  which  the  miners  go  to  and  from  their  work,  and  as  the 
corves  are  also  constantly  wheeling  along  all  the  time,  were  a  single  door,  such  as  d, 
so  often  opened,  the  ventilation  would  be  rendered  precarious  or  languid.  But  the 
double  doors  obviate  this  inconvenience ;  for  both  men  and  horses,  with  the  corves, 
in  a:oing  to  or  from  the  pit  bottom  a,  no  sooner  enter  the  door  d,  than  it  shuts  behind 
them,  and  encloses  them  in  the  still  air  contained  between  the  doors  d  and  c  ;  c  having 
prevented  the  air  from  changing  its  proper  course  while  d  was  open.  When  d  is  again 
slmt,  the  door  c  may  be  opened  without  inconvenience,  to  allow  the  men  and  horses  to 
pass  on  to  the  pit  bottom  at  a  ;  the  door  d  preventing  any  change  in  the  aerial  circulation 
while'the  door  c  is  open.  In  returning  from  the  pit,  the  same  rule  is  observed,  of  shut- 
ting one  of  the  double  doors,  before  the  other  is  opened. 

If  this  mode  of  disjoining  and  insulating  air-courses  from  each  other  be  once  fairly  con- 
ceived, the  continuance  of  the  separation  through  a  working  of  any  extent,  may  be  easily 
understood. 

When  carbonic  acid  gas  abounds,  or  when  the  fire-damp  is  in  very  small  quan- 
tity, the  air  may  be  conducted  from  the  shaft  to  the  dip-head  level,  and  by  placing 
stoppings  of  each  room  next  the  level,  it  may  be  carried  to  any  distance  along  the  dip- 
head  levels;  and  the  furthest  room  on  each  side  being  left  open,  the  air  is  suffered 
to  diffuse  itself  through  the  wastes,  along  the  wall  faces,  and  mount  in  the  upcast 
pit,  as  is  represented  in  fig.  1099.  But  should  the  air  become  stagnant  along  the 
wall  faces,  stoppings  are  set  up  throughout  the  galleries,  in  such  a  way  as  to  direct  the 
main  body  of  fresh  air  along  the  wall  faces  for  the  workmen,  while  a  partial  stream  of 
air  is  allowed  to  pass  through  the  stoppings,  to  prevent  any  accumulation  of  foul  air  in 
the  wastes. 

In  very  deep  and  extensive  collieries  more  elaborate  arrangements  for  ventilation  are 
introduced.  Here  the  circulation  is  made  active  by  rarefying  the  air  at  the  upcast 
shaft,  by  means  of  a  very  large  furnace  placed  cither  at  the  bottom  or  top  of  the 
shaft.  The  former  position  is  generally  preferred.  Fig.  834  exhibits  a  furnace 
placed  at  the  top  of  the  pit.  When  it  surmounts  a  single  pit,  or  a  single  division  of 
the  pit,  the  compartment  intended  for  the  upcast  is  made  air-tight  at  top,  by  placing 
strong  buntons  or  beams  across  it,  at  any  suitable  distance  from  the  mouth.  On  these 
bunions  a  close  scaffolding  of  plank  is  laid,  which  is  well  plastered  or  moated  over  with 
adhesive  plastic  clay.  A  little  way  below  the  scaffold,  a  passage  is  previously  cut,  either 
in  a  sloping  direction,  to  connect  the  current  of  air  with  the  furnace,  or  it  is  laid  horizon 
tally,  and  then  communicates  with  the  furnace  by  a  vertical  opening.  If  any  obstacle 
prevent  the  scaffold  from  being  erected  within  the  pit,  this  can  be  made  air-tight  at  top, 
and  a  brick  flue  carried  thence  along  the  surface  to  the  furnace. 

The  furnace  has  a  size  proportional  to  the  magnitude  of  the  ventilation,  and  the  chim- 
neys are  either  round  or  square,  being  from  50  to  100  feet  high,  with  an  inside  diameter 
of  from  5  to  9  feet  at  bottom,  tapering  upwards  to  a  diameter  of  from  2^^  feet  to  5  feet. 
Such  stalks  are  made  9  inches  thick  in  the  body  of  the  building,  and  a  little  thicker  at  bot- 
tom, where  they  are  lined  with  fire-bricks. 

The  plan  of  placing  the  furnace  at  the  bottom  of  the  pit  is,  however,  more  advan- 
tageous, because  the  shaft  through  which  the  air  ascends  to  the  furnace  at  the  pit 
mouth,  is  always  at  the  ordinary  temperature;  so  that  whenever  the  top  furnace  is  neg- 
lected, the  circulation  of  air  throughout  the  mine  becomes  languid,  and  dangerous  to 
the  workmen ;  whereas,  when  the  furnace  is  situated  at  the  bottom  of  the  shaft,  its  sides- 
get  heated,  like  those  of  a  chimney,  through  its  total  length,  so  that  though  the  heat  of 
the  furnace  be  accidentally  allowed  to  decline  or  become  extinct  for  a  little,  the  circa- 

Vol.  IL  3  H 


i: 


•^m 


418 


PITCOAL. 


1115 


To  prevent  the  annoyance  to  the  onsetters  at  the  bottom,  from  the  hot  smoke,  the  fol- 
lowmgpianhas  been  adopted,  as  shown  in  the  wood-cut,  ^g.  1114  where  a  represents 

.^  ..  the  lower  part  of  the  upcast  shaA ;  b,  the  furnace,  built  of 
brick,  arched  at  top,  with  its  sides  insulated  from  the  solid 
mass  of  coal  which  surrounds  it.  Between  the  furnace 
wall  and  the  coal  beds,  a  current  of  air  constantly  passes 
towards  the  shaft,  in  order  to  prevent  the  coal  calchine 
lire.  From  the  end  of  the  furnace  a  gallery  is  cut  in  a 
.  ^.      ,  ~        Q  f  .u  -  "Sing  direction  at  c,  which  communicates  with  the  shaft  at 

..^d,  about  Tor  8  fathoms  Irom  the  bottom  of  the  pit.     Thus  the  furnace  and  furnace- 
beeper  are  completely  disjoined  from  the  shaft;    and   the  pit  bottom  is  not  only  Jr^ 

■ES^  /s=r-1i iromall  encumbrances,  but  remains  comfortably  cool.     To  ob. 

viate  the  inconveniences  from  the  smoke  to  the  banksmen  in 
landing  the  coals  at  the  pit  mouth,  the  following  plan  has  been 
contrived  for  the  Newcastle  collieries,    ii-ig.  1115  represents  the 
mouth  of  the  pit ;  a  is  tlie  upcast  shaft,  provided  with  a  furnace 
at  bottom ;    b,  the  downcast  shaft,  by  which  the  supply  of  at- 
mospheric air  descends  ;   and  rf,  the  brattice  carried  above  the  pit 
mouth.    A  little  way  below  the  settle-boards,  a  gallery  c  is  pushed, 
m  communication  with   the   surface  from   the  downcast   ^^haft 
oyer  which  a  brick  tube  or  chimney  is  built  from  60  to  80  feet 
♦«        r»     *!.    .        o    ,  .    ^  >  7  or  8  feet  diameter  at  bottom,  and  4  or  5  feet  diameter  at 
top     On  the  top  of  this  chimney  a  deal  funnel  is  suspended  horizontally  oi  TpTvot 
like  a  turn-cap.     The  vane/,  made  also  of  deal,  keeps   he  mouth  of  the  funnel  alwavs 
m  the  same  direction  with  the  wind.     The  same  mechanism  is  mount^  at  "he  upcast 
shaft  .,  only  here  the  funnel  is  made  to  present  its  mouth  in  the  wind's  eve.     It  is  obvfous 
from  the  figure,  that  a  high  wind  will  rather  aid  than  check  the  ventilatLi  by  this  plan 
.nl]^^^^""'/- ^  f  •''•'"'^^,V^"  *^"^"^  ^^"^  established,  the  next  object  in  openin/up  a 

^o    /  M      ^*™P^«^"t  very  ingenious  distribution  of  which,  the  circulation  of  idr 
depends  at  the  commencement  of  the  excavations.  urcuiaiion  oi  air 

The    double    headways   course   is    represented    in  fig.  1116.,  where    a  is   the  one 
heading  or  gallery,  and  6  the  other;    the  former  bein|  immediately  connected  wftS 


the  upcast  side  of  the  pit  c,  and  the  latter  with  the 
downcast  side  of  the  pit  d.  The  pit  itself  is  made 
completely  air-tight  by  its  division  of  deals  from  top 
to  bottom,  called  the  brattice  wall ;   so  that  no  air 


«(, 


pillar  of  coal;    the  pillars  or  walls  of  coal,  marked  e,  are  called  stentinc  walls  •  Vn/thi 
openings  betwixt  them,  walls  or  thirlings.'   The  arrows  show  tte  diKn  of  ?he  ah- 
The  headings  a  and  6  are  generally  made  about  9  feet  wide,  the  stSLwans  6  or  8 

..d  downcast  nils    s.^rrL      •'"''''.'•<»'«:''  '"'''=•'  ""e  circalation  betwtat  the  upcast 
fi?.!-      wJ     ,  .1  earned  on;    but  whenever  the  workmen  cnt  through  the  fir«. 

S^h?-''  ""-^  ^"''r  "^  ".  ""^  •"■""'■-'^  »'  »>^  pi'  l™""".  "shut  •    in  consequence  of 
ruThTctf to'lh  teh  S'  wTrr-the'^rnes"  arrat'wtT"-?!:  'T"  ^^  ""^'""I'l 

the  last  thirling  through  which  ?he  air  was  circu^LL    .1  T  '.''''•''"? 's. -"^^e. 

fsT'-  '»•'"'-'-?«'."•«  stXiu  s^  piS°'^\h':tSn:^n'::mbered''rtt 

t'h?eh''Ue"s^lrrre\fa^stfter^rnt\T'^.'^-^^^^^^^^^^^ 

observe,  that  on  this  very  simple  pfan  a  stream  ff.^^        ^J  inspecting  the  figure,  we 

distance,  and  in  any  diLtionThoweVer  ,or,uo«s     S  be  circulated  to  any  required 

double  headways  course  a,  6,  is  pushrf  f^wari  "ther  1^.^..  ^    ?     "   '  '"^  """'^  ""* 
luired  to  he  carried  nn  ^t  .1,.  .         '"rwara,  other  double  headways  courses  are  re- 

Lie^e'Se^  SeT  htfUnoTXar  tf 2  1^  ^rk^^^t^-^^^ 

63 


PITCOAL. 


the 


419 


a  18  the  upcast,  and  b  the  downcast  shaft. 
The  air  advances  along  the  heading  c,  but 
cannot  proceed  further  in  that  direction  than 
the  pillar  rf,  being  obstructed  by  the  double 
doors  at  e.  It  therefore  advances  in  the  direc- 
tion of  the  arrows  to  the  foreheads  at  /,  and 
passing  through  the  last  thirling  made  there, 
returns  to  the  opposite  side  of  the  double  doors, 
ascends  now  the  heading  g,  to  the  foreheads  at 
h,  passes  through  the  last-made  thirling  at  that 
point,  and  descends,  in  the  heading  t,  till  it  is 
interrupted  by  the  double  doors  at  k.  The 
aerial  current  now  moves  along  the  heading  l, 
to  the  foreheads  at  w,  returns  by  the  last-made 
thirling  there,  along  the  heading  n,  and  finally 
goes  down  the  heading  o,  and  mounts  by  the 
upcast  shaft  a,  carrying  with  it  all  the  noxious 
gases  which  it  encountered  during  its  circui- 
tous journey.  This  wood-cut  is  a  faithful  representation  of  the  system  by  which  collieries 
of  the  greatest  extent  are  worked  and  ventilated.  In  some  of  these,  the  air  courses 
are  from  30  to  40  miles  long.  Thus  the  air  conducted  by  the  medium  of  a  shaft 
divided  by  a  brattice  wall  only  a  few  inches  thick,  after  descending  in  the  downcast  in 
one  compartment  of  the  pit  at  6  o'clock  in  the  morning,  must  thence  travel  through  a  cir- 
cuit of  nearly  30  miles,  and  cannot  arrive  at  its  reascending  compartment  on  the  other 
side  of  the  brattice,  or  pit  partition,  till  6  o'clock  in  the  evening,  supposing  it  to  move  all 
the  time  at  the  rate  of  2|  miles  per  hour.  Hence  we  see  that  the  primum  mobile  of  this 
mighty  circulation,  the  furnace,  must  be  carefully  looked  after,  since  its  irregularities 
may  affect  the  comfort,  or  even  the  existence  of  hundreds  of  miners  spread  over  these 
vast  subterraneous  labyrinths.  On  the  principles  just  laid  down,  it  appears  that  if  any 
number  of  boards  be  set  off  from  any  side  of  these  galleries,  either  in  a  level,  dip,  or  rise 
direction,  the  circulation  of  air  may  be  advanced  to  each  forehead,  by  an  ingoing  and  re- 
turning current. 

Yet  while  the  circulation  of  fresh  air  is  thus  advanced  to  the  last-made  thirling  next 
the  foreheads  /,  A,  and  in,  fig.  1117  and  moves  through  the  thirling  which  is  nearest  to 
the  face  of  every  board  and  room,  the  emission  of  fire-damp  is  frequently  so  abundant 
from  the  coaly  strata,  that  the  miners  dare  not  proceed  forwards  more  than  a  few  fevt 
from  that  aerial  circulation,  without  hazard  of  being  burned  by  the  combustion  of  the  gas 
at  their  candles.  To  guard  against  this  accident,  temporary  shifting  brattices  are  em- 
ployed. These  are  formed  of  deal,  about  |  of  an  inch  thick,  3  or  4  feet  broad,  and  10 
feet  long;  and  are  furnished  with  cross-bars  for  binding  the  deals  together,  and  a  few 
finger  loops  cut  through  them,  for  lifting  them  more  expeditiously,  in  order  to  place  them 
in  a  proper  position.  Where  inflammable  air  abounds,  a  store  of  such  brattice  deals 
should  be  kept  ready  for  emergencies. 

The  mode  of  applying  these  temporary  brattices,  or  deal  partitions,  is  shown  in  the 
accompanying  figure  (fig.  1118,  which  shows  how  the  air  circulates  freely  through  the 
1118 thirling  </,  rf,  before  the  brattices  are  placed.     At  b  and  c,  we  see  two  head- 
ing boards  or  rooms,  which  are  so  full  of  inflammable  air  as  to  be  unwork- 
able.    Props  are  now  erected  near  the  upper  end  of  the  pillar  e,  betwixt  the 
roof  and  pavement,  about  two  feet  clear  of  the  sides  of  the  next  pillar,  leav- 
ing room  for  the  miner  to  pass  along  between  the  pillar  side  and  the  brat- 
tice.   The  brattices  are  then  fastened  with  nails  to  the  props,  the  lowei 
edge  of  the  under  brattice  resting  on  the  pavement,  while  the  upper  edge  of 
the  upper  is  in  contact  with  the  roof.     By  this  means  any  variation  of  the 
height  in  the  bed  of  coal  is  compensated  by  the  overlap  of  the  brattice 
boards ;  and  as  these  are  advanced,  shifting  brattices  are  laid  close  to,  and 
alongside  of,  the  first  set.     The  miner  next  sets  up  additional  props  in  the  same  parallel 
line  with  the  former,  and  slides  the  brattices  forwards,  to  make  the  air  circulate  close 
to  the  forehead  where  he  is  working ;  and  he  regulates  the  distance  betwixt  the  brattice 
and  the  forehead  by  the  disengagement  of  fire-damp  and  the  velocity  of  the  aerial  circu- 
lation.    The  props  are  shown  at  d,  d,  and  the  brattices  at  /,/.    By  this  arrangement 
the  air  is  prevented  from  passing  directly  through  the  thirling  a,  and  is  forced  along  the 
right-hand  side  of  the  brattice,  and,  sweeping  over  the  wall  face  or  forehead,  returns  by 
the  back  of  the  brattice,  and  passes  through  the  thiiling  a.    It  is  prevented,  however, 
fwm  returning  in  ks  former  direction  by  the  brattice  planted  in  the  forehead  c,  whereby 
it  mounts  up  and  accomplishes  its  return  close  to  that  forehead.    Thus  headways  and 
boards  are  ventilated  till  another  thirling  is  made  at  the  upper  part  of  the  pillar.    The 
thirling  a  is  then  closed  by  a  brick  stopping,  and  the  brattice  boards  remored  forwards  for  a 
similar  operation. 


420 


PITCOAL. 


When  blowers  occur  in  the  roof,  and  force  the  strata  down,  so  as  to  produce  a  large 
vaulted  excavation,  the  accumulated  gas  must  be  swept  away ;  because,  after  filling  that 
space,  It  would  descend  in  an   unmixed  state  under  the  common   roof  of  the  coal 
removing  it  is  represented  in  /ig:.  1119,  where  a  is  the  bed  of  coal, 
h  the  blower,  c  the  excavation  left  by  the  downfall  of  the 
roof,  d  18  a  passing  door,  and  e  a  brattice.     By  this  arrange- 
ment the  aerial  current  is  carried  close  to  the  roof,  and  con- 
stantly sweeps  oil"  or  dilutes  the  inflammable  gas  of  the  blow- 
er, as  fast  as  it  issues.     The  arrows  show  the  direction  of  the 


PITCOAL. 


421 


The  manner  of 


1119 


.SgRJ^^^VV^^-'^^^''^^^^ 


A 


current ;  but  for  which,  the  accumulating  gas  would  be  mixed 
in  explosive  proportions  with  the  atmospheric  air,  and  destioy 
the  miners. 

There  is  another  modification  of  the  ventilating  system, 
where  the  air  aourses  are  traversed  across  ;  that  is,  when  one 
air-course  is  advanced  at  right  angles  to  another,  and  must 
.  pass  it  in  order  to  ventilate  the  workings  on  the  further  side. 

1  his  IS  accomplished  on  the  plan  shown  in  ^g.  1120  where  a  is  a  main  road  with  an  air- 
course,  over  which  the  other  air-course  6,  has  to  pass.  The  sides  of  this  air  channel  are 
built  of  bricks  arched  over  so  as  to  be  air-tight,  and  a  salleiy  is  driven  in  the  roof  strala 
as  shown  m  the  figure.  If  an  air-course,  as  a,  be  laid  over  with  planks  made  air-tight, 
crossmg  and  recrossing  may  be  effected  with  facility.  The  general  velocity  of  the  air  in 
these  ventilating  channels  is  from  3  to  4  feet  per  second,  or  about  2^  miles  per  hour,  and 
their  internal  dimensions  vary  from  5  to  6  feet  square,  allbrding  an  area  of  from  25  to  36 
square  feet. 

Mr.  Taylor's  hydraulic  air-pump,  formerly  described,  p.  173,  deseiTes  to  be  noticed 
1121    among  the  various  ingenious  contrivances  for  ventilating  mines,  Jarticulariy 
when  they  are  of  moderate  extent,      a  is  a  large  wooden  tub,  nearly  filled  with 
water,  through  whose  bottom  the  ventilating  pipe  h  passes  down  into  the  recesses 
of  the  mine.     Upon  the  top  of  6,  there  is  a  valve  e,  opening  upwards.     Over  h 
^y,    the  gasometer  vessel  is  inverted  in  a,  having  a  valve  also  opening  outwards  at  d\ 
m  m  ^^^"  ^^^^  ^esse\  is  depressed  by  any  moving  force,  the  air  contained  within  it  is 
expelled  through  d;  and  when  it  is  raised,  it  diminishes  the  atmospherical  pres- 
sure in  the  pipe  h,  and  thus  draws  air  out  of  the  mine  into  the  gasometer ;  which 
cannot  return  on  account  of  the  valve  at  «,  but  is  thrown  out  into  the  atmosphere 

1  through  d  at  the  next  descent. 
The  general  plan  of  distributing  the  air,  in  all  cases,  is  to  send  the  first  of  the 
current  that  descends  in  the  downcast  shaft  among  the  horses  in  the  stables  next 
among  the  workmen  in  the  foreheads,  after  which  the  air,  loaded  with  whatever 
mixtures  it  may  have  received,  is  made  to  traverse  the  old  wastes.  It  then  passes 
through  the  furnace  with  all  the  inflammable  gas  it  has  collected,  ascends  the  upcast  shaft 
and  is  dispersed  into  the  atmosphere.  This  system,  styled  coursing  the  air,  was  invented 
by  Mr.  Spedding  of  Cumberiand.  According  to  the  quantity  of  the  fire-damp  the 
coursing  is  conducted  either  up  one  room,  and  returned  by  the  next  alternately,  through 
the  whole  extent  of  the  works,  or  it  passes  along  2  or  3  connected  rooms,  and  returns  bv 
the  same  number.  ' 

This  adniirable  system  has  received  the  greatest  improvements  from  the  mining 
engineers  of  the  Newcastle  district,  and  especially  from  Mr.  Buddie  of  Wall^end  His 
plan  being  a  most  complete  scale  of  ventilation,  where  the  aerial  current  is  made 
to  sweep    away   every  comer  of  the  workings,  is  shown   in  ^g.ll22;  in  which    a 

represents  the  downcast,  and  b  the  upcast 
shaft.  By  pursuing  the  track  of  the  arrows, 
we  may  observe  that  the  air  passes  first  along 
the  two  rooms  c,  d,  having  free  access  to  each 
through  the  walls,  but  is  hindered  from 
entering  into  the  adjoining  rooms  by  the 
stoppings  which  form  the  air-courses.  It 
sweeps  along  the  wall  faces  of  the  rooms  c,  d, 
and  makes  a  return  down  the  rooms  e,  /, 
but  is  not  allowed  to  proceed  further  in  that 
direction  by  the   stoppings   g,   h.      It   then 

_  „    ^    ..™..,.^...s....v,  proceeds  to  the  foreheads  t,  k,  and   single 

courses  all  the  rooms  to  the  foreheads  /,  m;  from  this  point  it  would  go  directly  to  the 
upcast  pit  6,  were  it  not  prevented  by  the  stopping  «,  which  throws  it  again  into  double 
coursing  the  rooms,  till  it  arrives  at  o,  whence  it  goes  directly  to  the  furnace,  and 
ascends  the  shaft  b.  The  lines  across  each  other  represent  the  pR^Ing  doors ;  end  these 
may  be  aobsuluted  m  any  place  for  a  passage  where  there  is  a  Etop^^inj:.  The  stopping 
P,  near  the  bottom  of  the  downcast  shaft,  is  termed  a  main  stopping;  because  if  it 
were  removed,  the  whole  circulation  would    instantly  cease,  and   the   air,  instead  of 


1122 


traversing  in  the  direction  of  the  arrows,  would  go  directly  from  the  downeast  pit  a,  to 
the  upcast  pit  6,  along  the  gallery  q.  Hence  every  gallery  and  room  of  the  workings 
would  be  laid  dead,  as  it  is  termed,  and  be  immediately  filled  with  fire-damp,  which 
might  take  fire  either  at  the  workmen's  candles,  or  at  the  furnace  next  the  upcasl 
ehaft  b.  Thus  also  a  partial  stagnation  in  one  district  of  the  colliery,  would  be  pro- 
duced by  any  of  the  common  stoppings  being  accidentally  removed  or  destroyed,  since 
the  air  would  thereby  always  pursue  the  nearest  route  to  the  upcast  pit.  Main  stop- 
pings are  made  particularly  secure,  by  strong  additional  stone  buildings,  and  they  are 
set  up  at  different  places,  K)  maintain  the  main  air  courses  entire  in  the  event  of  an 
explosion ;  by  which  precautions  great  security  is  given  to  human  life.  This  system  of 
ventilation  may  be  extended  to  almost  any  distance  from  the  pit-bottom,  provided  the 
volume  of  fresh  air  introduced  be  adequate  to  dilute  sufficiently  the  fire-damp,  so  that 
the  mixture  shall  not  reach  the  explosive  point.  The  air,  by  this  management,  ven- 
tilates first  one  panel  of  work,  and  then  other  panels  in  succession,  passing  onwards 
through  the  barriers  or  panel  walls,  by  means  of  galleries,  as  in  fig.  843,  by  the 
principle  either  of  single,  double,  or  triple  coursing,  according  to  the  quantity  of  gas  in 

the  mine. 

In  ventilating  the  very  thick  coal  of  Staflfordshire,  though  there  is  much  inflammable 
air,  less  care  is  needed  than  in  the  north  of  England  collieries,  as  the  workings  are  very 
roomy,  and  the  air  courses  of  comparatively  small  extent.  The  air  is  conducted  down 
one  shaft,  carried  along  the  main  roads,  and  distributed  into  the  sides  of  work,  as  shown 
in  fig.  848.  A  narrow  gallery,  termed  the  air-head,  is  carried  in  the  upper  part  of  the 
coal,  in  the  rib  walls,  along  one  or  more  of  the  sides.  In  the  example  here  figured,  it  is 
carried  all  round,  and  the  air  enters  at  the  bolt-hole  e.  Lateral  openings,  named  spouts, 
are  led  from  the  air-head  gallery  into  the  side  of  work ;  and  the  circulating  stream  mixed 
with  the  gas  in  the  workings,  enters  by  these  spouts,  as  represented  by  the  arrows,  and 
returns  by  the  air-head  at  g,  to  the  upcast  pit. 

When  the  fire-damp  comes  off  suddenly  in  any  case,  rendering  the  air  foul  and  explo- 
sive at  the  foreheads,  if  no  other  remedy  be  found  eflfectual,  the  working  of  the  coal  must 
be  suspended,  and  a  current  of  air  sent  directly  from  the  fresh  in-going  stream,  in  order 
to  dilute  the  explosive  mixture,  before  it  reaches  the  furnace.  This  is  termed  skailivg 
the.  air  ;  for  otherwise  the  gas  would  kindle  at  the  furnace,  and  flame  backwards,  like  a 
train  of  gunpowder,  through  all  the  windings  of  the  work,  carrying  devastation  and 
death  in  its  track.  By  skailing  the  air,  however,  time  is  given  for  running  forward 
with  water,  and  drowning  the  furnace.  A  cascade  of  water  from  the  steam  engine 
pumps  is  then  allowed  to  fall  down  the  pit,  the  power  of  which,  through  a  fall  of  500  or 
600  feet,  is  so  great  in  carrying  down  a  body  of  air,  that  it  impels  a  sufl^cient  current 
through  every  part  of  the  workings.  The  ventilation  is  afterwards  put  into  its  usual 
train  at  leisure. 

In  collieries  which  have  oeen  worked  for  a  considerable  time,  and  particularly  in  such 
as  have  goaves,  creeps,  or  crushed  wastes,  the  disengagement  of  the  fire-damp  from  these 
recesses  is  much  influenced  by  the  state  of  atmospheric  pressure.  Should  this  be  suddenly 
diminished,  as  shown  by  the  fall  of  the  barometer,  the  fire-damp  suddenly  expands  and 
comes  forth  from  its  retirement,  polluting  the  galleries  of  the  mine  with  its  noxious 
presence.  But  an  increase  of  barometric  pressure  condenses  the  gases  of  the  mine,  and 
restrains  them  within  their  sequestered  limits.  It  is  therefore  requisite  that  the  coal- 
viewer  should  consult  the  barometer  before  inspecting  the  subterraneous  workings  of  an 
old  mine,  on  the  Monday  mornings,  in  order  to  know  what  precautions  must  be  observed 
in  his  personal  survey. 

The  catastrophe  of  an  explosion  in  an  extensive  coal-mine  is  horrible  in  the  extreme. 
Let  us  imagine  a  mine  upwards  of  100  fathoms  deep,  with  the  workings  extended  to  a 
great  distance  under  the  surrounding  countr3',  with  machinery  complete  in  all  its  parts, 
the  mining  operations  under  regular  discipline,  and  railways  conducted  through  all  its 
ramifications ;  the  stoppings,  passing  doors,  brattices,  and  the  entire  economy  of  the 
mine,  so  arranged  that  every  thing  moves  like  a  well-regulated  machine.  A  mine  of 
this  magnitude  at  full  work  is  a  scene  of  cheering  animation,  and  happy  industry ;  the 
sound  of  the  hammer  resounds  in  every  quarter,  and  the  numerous  carriages,  loaded  or 
empty,  passing  swiftly  to  and  fro  from  the  wall  faces  to  the  pit  bottom,  enliven  the 
gloomiest  recesses.  At  each  door  a  little  boy,  called  a  trapper,  is  stationed,  to  open  and 
shut  it.  Every  person  is  at  his  post,  displaying  an  alacrity  and  happiness  pleasingly 
contrasted  with  the  surrounding  gloom.  While  things  are  in  this  merry  train,  it  has 
but  too  frequently  happened  that  from  some  unforeseen  cause,  the  ventilation  has  partially 
stagnated,  allowing  a  quantity  of  the  fire-damp  to  accumulate  in  one  space  to  the  explo- 
sive pitch ;  or  a  blower  has  suddenly  sprung  forth,  and  the  unsuspecting  miner,  entering 
this  fatal  region  with  his  candle,  sets  the  whole  in  a  blaze  of  burning  air,  which  imme- 
diately suflfocates  and  scorches  to  death  every  living  creature  within  its  sphere,  while 
multitudes  beyond  the  reach  of  the  flame  are  dashed  to  pieces  by  the  force  of  the  explo- 
sion, rolling  like  thunder  along  the  winding  galleries.      Sometimes  the  explosivi  '^'  " 


mmm 


*"«^^ 


422 


PITCOAL. 


PITCOALr. 


423 


ii 


il 


i 


seems  to  linger  in  one  district  for  a  few  moments ;  then  gathering  strength  for  a  giant 
effort,  it  rushes  forth  from  its  cell  with  the  Tiolence  of  a  hurricane,  and  the  speed  of 
lightning,  destroying  every  obstacle  in  its  way  to  the  upcast  shaft.  Its  power  seems  to 
he  irresistible.  The  stoppings  are  burst  through,  the  doors  are  shivered  into  a  thousand 
pieces;  while  the  unfortunate  miners,  men,  women,  and  boys,  are  swept  along  with  an 
inconceivable  velocity,  in  one  body,  with  the  horses,  carriages,  corves,  and  coals.  Should 
a  massive  pillar  obstruct  the  direct  course  of  the  aerial  torrent,  all  these  objects  are 
dashed  against  it,  and  there  prostrated  or  heaped  up  in  a  mass  of  common  ruin,  mutila- 
tion, and  death.  Others  are  carried  directly  to  the  shaft,  and  are  either  buried  there 
amid  the  wreck,  or  are  blown  up  and  ejected  from  the  pit  mouth.  Even  at  this  distance 
from  the  explosive  den,  the  blast  is  often  so  powerful^  that  it  frequently  tears  the  brattice 
walls  of  the  shaft  to  pieces,  and  blows  the  corves  suspended  in  the  shaft  as  high  up  into 
)he  open  air  as  the  ropes  will  permit.  Not  unfrequently,  indeed,  the  ponderous  pulley- 
wheels  are  blown  from  the  pit-head  frame,  and  carried  to  a  considerable  distance  in  the 
bosom  of  a  thick  cloud  of  coals  and  coal  dist  brought  up  from  the  mine  by  the  fire-damp, 
whose  explosion  shakes  absolutely  the  superincumbent  solid  earth  itself,  with  a  mimic 
earthquake.  The  dust  of  the  ruins  is  sometimes  thrown  to  such  a  height  above  the  pit 
as  to  obscure  the  light  of  the  sun.  The  silence  which  succeeds  to  this  awful  turmoil  is 
no  less  formidable ;  for  the  atmospheric  back-draught,  rushing  down  the  shaft,  denotes 
the  consumption  of  vital  air  in  the  mine,  and  the  production  of  the  deleterious  choke-damp 
and  azote. 

Though  many  of  the  miners  may  have  escaped  by  their  distance  in  the  workings  from 
the  destructive  blast  and  the  fire,  yet  their  fate  may  perhaps  be  more  deplorable.  They 
hear  the  explosion,  and  are  well  aware  of  its  certain  consequences.  Every  one,  anxious 
to  secure  his  personal  safety,  strains  every  faculty  to  reach  the  pit-bottom.  As  the 
lights  are  usually  extinguished  by  the  explosion,  they  have  to  grope  their  way  in  utter 
darkness.  Some  have  made  most  marvellous  escapes,  after  clambering  over  the  rubbish 
of  fallen  roofs,  under  which  their  companions  are  entombed  ;  but  others,  wandering  into 
uncertain  alleys,  tremble  lest  they  should  encounter  the  pestilential  airs.  At  last  they 
feel  their  power,  and  aware  that  their  fate  is  sealed,  they  cease  to  struggle  with  their  in- 
evitable doom ;  they  deliberately  assume  the  posture  of  repose,  and  fall  asleep  in  death. 
Such  has  been  too  often  the  fate  of  the  hardy  and  intelligent  miners  who  immure  them- 
selves deep  beneath  the  ground,  and  venture  their  lives  for  the  comfort  of  their  fellow- 
men  ;  and  such  frequently  is  the  ruinous  issue  of  the  best  ordered  and  most  prosperous 
mining  concerns. 

In  such  circumstances  the  mining  engineers  or  coal  viewers  have  a  dangerous  and 
difficult  duty  to  perform.  The  pit  into  which  they  must  descend  as  soon  as  possible,  is 
rendered  unsafe  by  many  causes ;  by  the  wrecks  of  loose  timber  lorn  awav  by  the 
eruption,  or  by  the  unrespirable  gases  ;  by  the  ignition  perhaps  of  a  portion  of  the  coal 
itself,  or  by  the  flame  of  a  blower  of  fire-damp ;  either  of  which  would  produce  violent 
and  repeated  explosions  whenever  the  gas  may  again  accumulate  to  the  proper  degree. 
Such  a  predicament  is  not  uncommon,  and  it  is  one  against  which  no  human  skilfcan 
guard.  Yet  even  here,  the  sense  of  duty,  and  the  hope  of  saving  some  workmen  from  a 
lingering  death  by  wounds  or  suffocation,  lead  this  intrepid  class  of  men  to  descend  amid 
the  very  demons  of  the  mine. 

As  soon  as  the  ventilation  is  restored  by  temporary  brattices,  the  stoppings  and  doors 
are  rebuilt  in  a  substantial  manner,  and  the  workings  are  resumed  with  the  wonted 
activity.  From  an  inspection  of  Jig.  864,  p.  1035,  it  is  obvious  that  the  stability  of  the 
main  stopping  p,  is  an  important  point ;  for  which  reason  it  is  counterforted  by  strong 
walls  of  stone,  to  resist  the  explosive  force  of  fire-damp. 

When  it  is  known  that  fire  exists  in  the  Avastes,  either  by  the  burning  of  the  small 
coal-dust  along  the  roads,  or  from  the  ignition  of  the  solid  coal  by  a  blower  of  gas,  the 
inspection  of  the  mine  is  incomparably  more  hazardous,  as  safety  cannot  be  ensured  for 
an  instant ;  for  if  the  extrication  of  gas  be  great,  it  rapidly  accumulates,  and  whenever  it 
reaches  the  place  where  the  fire  exists,  a  new  explosion  takes  place.  There  have  been 
examples  of  the  most  furious  detonations  occurring  regularly  after  the  interval  of  about 
an  hour,  and  being  thus  repeated  36  times  in  less  than  two  days,  each  eruption  appearing 
at  the  pit  mouth  like  the  blast  of  a  volcano.  It  would  be  madness  for  any  one  to  attempt 
a  descent  in  such  circumstances.  The  only  resource  is  to  moat  up  the  pit,  and  check  the 
combustion  by  exclusion  of  atmospheric  air,  or  to  drown  the  workings  by  letting  the  water 
accumulate  below  ground. 

When  fire  exists  in  the  wastes,  with  less  apparent  risk  of  life,  water  is  driven  upon  it 
by  portable  fire-extmguishing  engines,  or  small  cannon  are  discharged  near  the  burning 
coal,  and  the  concussion  thus  produced  in  the  air  sometimes  helps  to  extinguish  the  flame. 
Since  the  primary  cause  of  these  tremendous  catastrophes  is  the  accension  of  the 
explosive  gases  by  the  candle  of  the  miner,  it  has  been  long  a  desideratum  to  procuif 
light  of  such  a  nature  as  may  not  possess  the  power  of  kindling  the  fire-damp.  The 
tiain  of  light  producible  from  the  friction  of  flint  and  steel,  by  a  mechanism  called 


a  »teel  miU,  has  been  long  kncwn,  and  afforded  a  tolerable  gleam,  with  which  the  mmera 
were  cbliged  to  content  themselves  in  hazardous  atmospheres.  ■„^^r.iA 

iTconsists  of  a  small  frame  of  iron,  mounted  with  a  wheel  and  Pinion,  which  give  raprf 
-otation  to  a  disk  of  hard  steel  placed  upright,  to  whose  edge  a  piece  of  flint  is  appUed. 
?he  use  of  this  machine  entailed  on  the  miner  the  expense  of  an  attendant,  called  the 
miller,  who  gave  him  light.     Nor  was  the  light  altogether  safe,  for  occasionally  the  ignited 
shower  of  steel  particles  attained  to  a  sufficient  heat  to  set  fire  to  the  ?«•?■? »°JP-    _„^    - 
At  length  the  attention  of  the  scientific  world  was  powerfully  attracted  to  the  means  of 
lighting  the  miner  with  safety,  by  an  awful  catastrophe  which  happened  at  Felhng  LoJ- 
Sery,  near  Newcastle,  on  the  25th  May,  1812.     This  mine  was  working  with  great  v.gor, 
under  a  well-regulated  system  of  ventilation,  set  in  action  by  a  furnace  ^ndair-tube  placed 
over  a  rise  pit  in  elevated  ground.     The  depth  of  winning  was  above  1^0  fathoms ;  25 
acres  of  coal  had  been  excavated,  and  one  pit  was  yielding  at  the  rate  of  1700  tons  per 
week.     At  11  o'clock  in  the  forenoon  the  night  shift  of  miners  was  relieved  by  the  day 
shift;   121  persons  were  in  the  mine,  at  their  several  stations,  when,  at  half-past  11,  the 
gas  fired,  with  a  most  awful  explosion,  which  alarmed  all  the  neighboring  villages.     The 
lubterraieous  fire  broke  forth  with  two  heavy  discharges  from  the  dip-pit,  and  these  were 
in«;tanlly  followed  by  one  from  the  rise-pit.    A  sUght  trembbng,  as  from  an  earthquake 
was  felt  for  about  half  a  mile  round  the  colliery,  and  the  noise  of  the  explosion,  though 
dull,  was  heard  at  from  3  to  4  mUes'  distance.     Immense  quantities  of  dust  and  small 
coal  accompanied  these  blasts,  and  rose  high  into  the  air,  in  the  form  of  an  inverted  cone. 
The  heaviest  part  of  the  ejected  matter,  such  as  corves,  wood,  and  small  coal,  fell  near 
iie  p  ts  ;  but  the  dust,  borne  away  by  a  strong  west  wind,  feU  in  a  contmuous  shower  a 
mUe  and  a  half  from  the  pit.     In  the  adjoining  village  of  Heworth  it  caused  a  darkne^ 
Uke  that  of  early  twilight,  covering  the  roads  where  it  feU  so  thickly  that  the  footsteps 
of  passengers  were  imprinted  in  it.     The  heads  of  both  shalj-frames  were  blown  off^ 
thefr  sides%et  on  fire,  aid  their  pulleys  shattered  to  pieces     The  <^^^^^f'^'^'^^^ 
the  rise-pit  into  the  horizontal  part  of  the  ventilating  tube,  was  about  3   nches  thick 
and  speedily  burnt  to  a  cinder;  pieces  of  burning  coal,  driven  off  he  solid  st-atum  of  the 
mine,  were  also  blown  out  of  this  shaft.     Of  the  121  persons  in  the  mine  at  the  time  of 
Se  explosion,  only  32  were  drawn  up  the  pit  alive,  3  of  whom  died  a  few  hours  after  the 
accideJit,     Thus  no  less  than  92  valuable  lives  were  instantaneously  destroy  ed  by  this 
pestilential  fire  damp.     The  scene  of  distress  among  the  relatives  at  the  pit  mouth  was 

indescribably  sorrowful.  ^u.-^u  ^;„ht  k„«i 

Dr.  W.  Reid  Clannv,  of  Sunderland,  was  the  first  to  contrive  a  lamp  which  might  hnm 
among  explosive  air  without  communicating  flame  to  the  gas  in  which  it  was  pl^nged. 
This  he  ertected,  in  1813,  by  means  of  an  air-tight  lamp,  with  a  glass  ^jo^jt  the  flame  of 
which  was  supii>rted  by  blowing  fresh  air  from  a  smal  pair  of  bellows  through  a  stratum 
of  water  in  the  bottom  of  the  lamp,  while  the  heated  air  passed  out  t^^^^ough  water  by  a 
recurved  tube  at  top.  By  this  means  the  air  within  the  lamp  was  completelyinsulated 
from  the  surrounding  atmosphere.  This  lamp  was  the  first  ever  taken  ^to  a  body  of  m 
flammable  air  in  a  coal-mine,  at  the  exploding  point,  without  setting  fire  to  the  gas  around 
it.  Dr.  Clanny  made  another  lamp  upon  an  improved  plan  by  introducing  into  it  the 
steam  of  water  generated  in  a  small  vessel  at  the  top  of  the  lamp,  heated  by  the  flame 
The  chiefobjection  to  these  lamps  is  their  inconvenience  in  use. 

Various  other  schemes  of  safe-lamps  were  off-ered  to  the  miner  by  ingemmis  ^echam- 
cians,  but  they  have  been  all  superseded  by  the  admirable  invention  of  Sir  H- Davy, 
founded  on  his  fine  researches  upon  flame.  The  lamp  of  Davy  was  instantly  tried  aiid 
approved  of  by  Mr.  Buddie  and  the  principal  mining  engineers  of  the  Newcastle  district. 
A  perfect  security  of  accident  is  therefore  afforded  to  the  miner  m  the  use  of  a  lamp  which 
transmits  its  light,  and  is  fed  with  air,  through  a  cylinder  of  wire  gauze  ;  and  this  inyen- 
tion  has  the  advantage  of  requiring  no  machinery,  no  philosophical  knowledge  to  direct 
its  use,  and  is  made  at  a  very  cheap  rate.  .       «  ^.     ^      , 

In  the  course  of  a  long  and  laborious  investigation  on  the  properties  of  the  firedamp, 
Md  the  nature  and  communication  of  flame.  Sir  H.  Davy  ascertained  that  the  explosions 
o(  inflammable  gases  were  incapable  of  being  passed  through  long  narrow  metallic  tubes; 
and  that  this  principle  of  securilv  was  still  obtained  by  diminishing  their  length  and 
diameter  at  the  same  time,  and  likewise  diminishing  their  length,  and  increasing  Itieir 
number,  so  that  a  great  number  of  small  apertures  would  not  pass  an  explosion,  when 
their  depth  was  equal  to  their  diameter.  This  fact  led  him  to  trials  upon  sieves  made  ol 
wire-gauze,  or  metallic  plates  perforated  with  numerous  small  holes ;  and  he  found  it  wa? 
impossible  to  pass  explosions  through  them.  ,  _. 

The  apertures  in  the  gauze  should  never  be  more  than  l-20th  of  an  inch  square,  in 
the  working  models  sent  by  Sir  H.  to  the  mines,  there  were  748  apertures  in  the  square 
inch,  and  the  wire  was  about  the  40th  of  an  inch  diameter.  The  cage  or  cylinder  ol 
wire-gauze  should  be  made  by  double  joinings,  the  gauze  being  folded  over  in  such  a 
manner  as  to  leave  no  apertures.  It  should  not  be  more  than  two  inches  in  diameter ; 
for  in  large  cylinders  the  combustion  of  the  fire-damp  renders  the  top  inconvenienUy 


.i^'^^— -iW 


II  V 

I  I  ' 
III 

ill  I   : 


424 


PITCOAL. 


3 


-x. 


of  4  or  5  turns      All  ioinina,  f„  tk!  y^*'*^^'^  should  be  fastened  to  the  lamp  by  a  screw 
ID  the  wire  gauze.  ttperiure  exists  m  the  apparatus  larger  than 

distinct  iia^e-peS:^  Ta  HrZSfi:Z\li!^%^"^  """''  ^  -«^""  "'  "»« 

When  aVndle  hu   trfiS^^d  ,  LfS'^aTtn'o'l':;'''?""'!!'"?''  ^"'■?^  """*"?  «»■»*• 
of  flame  is  wen  of  a  fine  skv  hl.?^  «7.k    S  ™"n""'  »"■. «  d'stinct  and  wellnlefined  cone 

yellow  to  the  an'ei  of  The  c„„^      R»l- 1     .k°         ""'  "*'  "''"='''  »"<'  «''«»'=<=  "f  «  bright 

[he  cone,  whicrhets  Lress^of  ^T^:^^^^Zu7:iii'zvir'''^''  ^"^r""'"* 

be  seen  bv  nlacino-  onp  nf  th*.  ho„^o  I'^evenis  ineeje  Irom  discernms:.     This  may 

candle.  a„7a.nhldrancef\S;nT:':^th:t\h'el:a  .'"'"'f  ^''V"^  ""'r  '"« 
yellow  flame  may  be  seen  and  no  mnre       Ri^:,       1   .^""  •"""'  "'^  ""«  »P"  o*^  ">« 

will  be  distinctly' observed  close  to  the  a  Jx'^of  fh^v V'  ^'"P'  "'.  '"*  ™""'  "^™  "' 
quarter  of  an  inch  in  Ie™th       ThU  ton  ifof /,S? '^  •  ^I  "°™^' {^"^  »"  '='''"•'  '»  » 

tt^flame^XtlVwry^^^^^ 

s:'»t^-T^-ror^^^^^^^^^^^ 

entirely  on  the  appearance  which  thi^haze  assume,  i^  T.  ^'^"^1^^^,  ^^  '"»?^'-^>  ^^Pends 
the  proportions  of  the'a^ious  admSes    '     "'    '"'  "'"^  modifications,  according  to 

of  rd:s"UwrcS! :«?  trflt^'tshtt  t^nr  Vh  ^-Ih^^  ^^^  ^'^  -^^^• 

copious,  the  flame  goes  out,  and  the  miSl'rs'immSiaTet  reul  e  "^''"^  ''^^  '"^  ^^^"  "^°^« 

Ms'^an'dleTanT  advi'ncTs  w^t'™camls°sretV  ir^nl"'-^"^^.^^  ^^^  ^-^  ^"- 

screening  'the  flame  ^th  ^e  ri^ht  andts'lhe^S^^^^^  rf '^  S!"  '^'  ^'^  '^"^'  ^"^^ 
gallery  next  the  roof,  he  holds  the  candle  as  low  ««  il  ^  **,'  ,'"  ^^^  "PP^*"  P**"^  **^  ^^^^ 
the  tip,  he  moves  forwards/  If  the  "as  besrilnL^rit^^^  ^''P'"^  ^'l  '^'  ^^'^  «" 
without  observing  any  material  change  in  hfsl^h  ^But  f  in  hr'7'''^  ?'  ^""''^'^ 
the  tip  to  elongate,  and  take  a  bluish-gray  color  he  is  n,, t  nn  h'  ^''*!!r  ^^.  ^^^^^''^^ 
with  much  caution ;  and  if  the  tip  beein?L^n?rI  L  ^  P"^'"*  '''^  »"^"*'  ^"'^  ^^^PS  on 
ing  the  candle  near  the  pavement  erSltrW?-*     ^'"^P''/^^  ««  one  knee,  and  hold- 

gc^s  as  it  approaches  the  r"of?  '  If  thel^Js  bTcoP  ou^^  the  T"''''^  '''  '''^"--^^  ^'  ""^^'- 
spire,  as  well  as  the  top.     It  is  in  -eneral  rlrknn»S  ^    '  ""T  elongates  into  a  sharp 

the  bluish-gray  to  a  fine  blue  color'accomnW  "^^^^  ^^^  ^'P  <^h«"?«  from 

rapidly  upwari  through  the  Sam^'  an"tT"wh"en  thTsv^'  ""''^'"^  ^^K^'  "''^^  P«^» 
OU8,  a  sudden  movement  of  the  hands  or  bodv  is  I^Wp  ti^^"^'  ^ -^  manifestly  danger- 
of  the  fire-damp.  The  experienced  minPrihpJ/  /"*  V^"""^  *-"'^^°"  ^^  agitation 
candle  to  the  pavement,  an^hen  tu^  n'  rou^^^^^^^^  ^"^  «»"^'°"^Jy  ^^^ers  his 

his  right  hand  and  extinguishes  the  flame  with  ht' I  ^'  ^'I  l^^'^""^  ^^''^^y*  ""'  «^'P^  "P 
too  far,  and  approach  the  tdy  of  gas  In  an  exnln"?""  and  thumb.  Should  he  venture 
rapidly  elongates,  and  the  whole  Wsefin  a  sharn  ^n  r'""^  condition,  the  tip  of  the  candle 
the  whole  surrounding  atmosphere  is  "„  a  b W  ?n  TT^'  '""'*"'  ^"  ^^"'^^ '  ^"'^  *^^" 
ravage  is  the  consequence,  to  an  extent  proDortlonS  f  l"""""  ^°.'"^'il  ^"^  destructive 
Safety  Lamp,  and  Venti^tion  P'-oportioned  to  the  quantity  of  fire-damp.     See 

Almost  every  colUery,  aAer'  having  ^:l'Tor^tr''^l  ti:;:r^vXec;ri^^  .^S 


PITCOAL. 


425 


.he  candle ;  so  that  while  in  one  mine  liable  to  fire-damp  an  explosion  will  take  place 
with  a  top  less  than  an  inch  long,  in  another  mine  the  top  may  be  two  inches  high,  and 
yet  the  air  be  considerably  under  the  point  of  accension.  These  differences  depend  on 
several  particulars.  If  the  gas  has  not  passed  through  a  long  course  of  ventilation,  and 
is  little  mixed  with  air,  it  will  ignite  with  a  very  short  top ;  while,  on  the  other  hand,  a 
gas  which  has  run  through  a  ventilation  of  20  or  30  miles  may  cause  the  production  of 
a  long  top  without  hazard.  It  is  hence  obvious,  that  skilful  experience,  and  thorough 
practical  knowledge,  are  the  only  sure  guides  in  these  cases. 

We  shall  now  describe  briefly  the  modern  modes  of  working  coals  a-dipping  of,  and 
deeper  than,  the  engine-pit  bottom.  One  of  these  consists  in  laying  a  working  pump 
barrel  with  a  long  wind-bore  at  the  bottom  of  the  downset  mine,  furnished  with  a  smooth 
rod  working  through  a  collar  at  the  top  of  the  working  barrel.  At  one  side  of  this, 
near  the  top,  a  kneed  pipe  is  attached,  and  from  it  pipes  are  carried  to  the  point  ol 
delivery,  either  at  the  engine  pit  bottom  or  day  level,  as  represented  in  j?g.  1123. 
The  spears  are  worked  sometimes    by   rods   connected   with    the  machinery   at  the 


1123 


1124 


■/ 


k 


^ 


la  a 


m 


surface;  in  which  case  the  spears,  if  very  long,  i^re  either  sus- 
pended   from   swing  or  pendulum   rods,  or   move  on   friction 
rollers.     But  since  the  action  of  the  spears,  running  with  great 
velocity  the  total  length  of  the  engine  stroke,  very  soon  tears 
every  thing  to  pieces,  the  motion  of  the  spears  under  ground  has 
been  reduced  from  6  or  8  feet,  the  length  of  the  engine  stroke, 
to   about    15   inches ;  and    the     due   speed    in   the   pump    is 
effected  by  the  centring  of  a  beam,  and  the  attachment  of  the 
spears  to  it,  as  represented  in  yig.  1124,  where  a  is  the  working 
barrel,   6   the  beam  centred   at   c,   having  an   arc-head   and 
martingale  sinking-chain.      The  spears  d  are  fastened   by  a 
strong  bolt,  which  passes  through  the  beam ;  and  there  are  several  holes,  b> 
means  of  which  the  stroke  in  the  pumps  can  be  lengthened  or  shortened  at 
convenience.      The  movement  of  the  spears  is  regulated  by  a  strong  iron 
quadrant  or  wheel  at  the  bottom. 

In  level-free  coals,  these  pumps  may  be  worked  by  a  water-wheel,  stationed 
near  the  bottom  of  the  pit,  impelled  by  water  falling  down  the  shaft,  to  be 
'discharged  by  the  level  to  the  day  (day-level). 

But  the  preferable  plan  of  working  under-dip  coal,  is  that  recently 
adopted  by  the  Newcastle  engineers ;  and  consists  in  running  a  mine  a-dipping  of  lbs 
engine-pit,  in  such  direction  of  the  dip  as  is  most  convenient;  and  both  coals  and 
water  are  brought  up  the  rise  of  the  coal  by  means  of  high-pressure  engines,  working 
with  a  power  of  from  30  to  50  pounds  on  the  square  inch.  These  machines  are 
quite  under  command,  and,  producing  much  power  in  little  space,  they  are  the  most 
applicable  for  underground  work.  An  excavation  is  made  for  them  in  the  strata  above 
the  coal,  and  the  air  used  for  the  furnace  under  the  boiler,  is  the  returned  air  of  the 
mine  ventilation.  In  the  dip-mine  a  double  tram-road  is  laid;  so  that  while  a  number 
of  loaded  corves  are  ascending,  an  equal  number  of  empty  ones  are  going  down. 
Although  this  improved  method  has  been  introduced  only  a  few  years  back,  under-dip 
workings  have  been  already  executed  more  than  an  English  mile  under-dip  of  the 
engine-pit  bottom,  by  means  of  three  of  these  high-pressure  engines,  placed  at  equal 
distances  in  the  under-dip  mine.  It  may  hence  be  inferred,  that  this  mode  of  working 
is  susceptible  of  most  extensive  application ;  and  in  place  of  sinking  pits  of  excessive 
depth  upon  the  dip  of  the  coal,  at  an  almost  ruinous  expense,  much  of  the  under-dip  coal 
will  in  future  be  worked  by  means  of  the  actual  engine-pits.  In  the  Newcastle  district, 
coals  are  now  working  in  an  engine  pit  1 15  fathoms  deep  under-dip  of  the  engine-pit 
bottom,  above  1600  yards,  and  fully  80  fathoms  of  perpendicular  depth  more  than  the 
bottom  of  the  pit. 

If  an  engine-pit  be  sunk  to  a  given  coal  at  a  certain  depth,  all  the  other  coals  of  the 

1125  coal-field,  both  above  and  below  the 

coal   sunk   to,  can    be  drained   and 


worked  to  the  same  depth,  by  driving 
^  a  level  cross-cut  mine,  both  to  the 
dip  and  rise,  till  all  the  coals  are  in- 
A  k         tersected,  as  represented  in  fig.  1125 

where  a  is  the  engine-pit  bottom  reaching  to  the  coal  a ;  and  6,  c,  d,  e, /,  coals  lying 
above  the  coal  a  ;  the  coals  which  lie  below  it,  g,  A,  t ;  k  is  the  forehead  of  the  cross-cut 
mine,  intersecting  all  the  lower  coals ;  and  /,  the  other  forehead  of  the  mine,  intersecting 
all  the  upper  coals. 

In  the  "  Report  from  the  select  committee  of  the  House  of  Lords,  appointed  to  take 
into  consideration  the  state  of  the  coal  trade  in  the  United  Kingdom,"  printed  in  June, 
1829,  under  the  head  of  Mr.  Buddie's  evidence  we  have  an  excellent  description  of  the 
Vol.  it.  8  I 


426 


PITCOAL. 


PITCOAL. 


427 


i 


i 


It 


nature  and  progress  of  creeps,  which  we  have  adverted  to  in  the  preceding  account. 
The  annexed  Jig.  869  exhibits  the  creep  in  all  its  progressive  stages,  from  its  commence- 
ment until  it  has  completely  closed  all  the  workings,  and  crushed  the  pillars  of  coal. 
The  section  of  the  figures  supposes  us  standing  on  the  level  of  the  different  galleries 
which  are  opened  in  the  seam.  The  black  is  the  coal  pillars  between  each  gallery ;  when 
these  are  weakened  too  much,  or,  in  other  words,  when  their  bases  become  too  narrow  foi 
the  pavement  below,  by  the  pressure  of  the  incumbent  stratification,  they  sink  down  into 
the  pavement,  and  the  first  appeaiance  is  a  little  curvature  in  the  bottom  of  each  gallery: 
that  is  the  first  symptom  obvious  to  sight ;  but  it  may  generally  be  heard  before  it  is  seen. 
The  next  stage  is  when  the  pavement  begins  to  open  with  a  crack  lonsitudinally.  The 
next  stage  is  when  that  crack  is  completed,  and  it  assumes  the  shape  of  a  metal  ridge. 
The  next  is  when  the  metal  ridge  reaches  the  roof.  The  next  stage  is  when  the  peak 
of  the  metal  ridge  becomes  flattened  by  pressure,  and  forced  into  a  horizontal  direction, 
and  becomes  quite  close;  just  at  this  moment  the  coal  pillars  berm  to  sustain  part  of  the 
pressure.  The  next  is  when  the  coal  pillars  take  part  of  the  pn  <siure.  The  last  stage 
is  when  it  is  dead  and  settled;  that  is,  when  the  metal  or  factitious  ridge,  formed  by  the 
sinking  of  the  pillar  into  the  pavement,  bears,  in  common  with  the  pillars  of  coal  on  each 
side,  the  full  pressure,  and  the  coal  becomes  crushed  or  cracked,  and  can  be  no  longer 
worked,  except  by  a  very  expensive  and  dangerous  process.     Fig.  1126. 

1     1126       2  3  4  5  6 


1.  First  stage  of  active  creep. 

2.  Second    do. 

3.  Third      do. 

4.  Fourth    do. 


5.  The  metal  ridge  closed,  and  the  creep 
beginning  to  settle. 

6.  The  creep  settled,  the  metal  ridges  being 
closely  compressed,  and  supporting  the  roof. 


The  quantity  of  coals,  cinders,  and  culm  shipped  coastwise,  and  exported  from  the 
several  ports  of  the  United  Kingdom  in  the  year  1837,  was  8,204,301  tons ;  in  1836,  the 
quantity  was  7,389,272  tons,  being  an  increase  of  815,029  tons,  or  1103  per  cent,  in 
favor  of  1837. 

The  following  Table  shows  the  separate  proportions  of  this  quantity  supplied  by 
England  and  Wales,  Scotland  and  Ireland  : — 


1836. 

1837. 

Increase. 

England  and  Wales     - 
Scotland  -        -        - 
Ireland        -        -        - 

Total      - 

Tons. 

6,757,937 

624,308 

7,027 

Tons. 
7,570,254 
626,532 
7,515 

Tuns. 

812,317  or  12-02  per  cent. 
2,2C4  -     0-36 
488  -     6-94 

7,389,272 

8,204,301 

815,029  or  11-03  percent. 

PITCOAL,  ANALYSIS  OF.  The  greater  part  of  ftie  analyses  of  coals  hitherto 
published  have  been  confined  to  the  proportions  of  carbon,  hydrogen,  and  oxygen,  to 
the  neglect  of  the  sulphur,  which  exists  in  many  coals  to  a  degree  unwholesome  for 
their  domestic  use,  pernicious  for  the  smelting  of  iron,  and  detrimental  to  the 
production  of  gas;  since  the  sulphuretted  hj-drogen  produced  requires  so  much 
washing  and  purification  as  at  the  same  time  to  impoverish  the  light  by  condensing 
much  of  the  olefiant  gas,  its  most  luminiferous  constituent.  In  the  numerous  reports 
upon  the  composition  of  coals  which  I  have  been  professionally  called  upon  to  make,  I 
have  always  sought  to  determine  the  proportion  of  sulphur,  which  may  be  done  readily 
to  one  part  in  a  thousand ;  as  also,  that  of  combustible  gaseous  matter,  of  coke,  and 
of  incombustible  ashes. 

The  following  coals  have  been  found  to  be  of  excellent  quality,  as  containing  very 
little  sulphur,  seldom  much  above  1  per  cent.,  and  little  incombustible  matter, — hence 
well  adapted  as  fuel,  whether  for  steam  navigation,  for  iron  smelting,  for  household 
consumption  or  for  gas,  according  to  their  relative  proportions  of  carbon  and  hy- 
drogen :  a  relative  excess  of  carbon  constituting  a  coal  best  adapted  for  furnaces  of 
various  kinds,  while  a  relative  excess  of  hydrogen  forms  the  best  coal  for  the  common 
grates  and  gas  works. 

1.  Mr.  FowelVi  Duffry  or  Steam  Coo/.— Specific  g^a^'ity,  1-32;  ashes,  per  cent,  2*6 ; 


^1!^ 


gaseous  products  in  a  luted  crucible,  14;  brilliant  coke,  86:  not  more  than  1  per 
eent.  of  sulphur;  while  many  of  the  Newcastle  coals  contain  from  4  to  6,  and  others 
which  I  have  examined  from  8  to  10  of  the  same  noxious  constituent ;  and  which  is  a 
lees  powerful  calorific  constituent  than  hydrogen  and  carbon. 

%  T/iC  Blackley  Hunt  Goal  of  ianca«Aer«.— Specific  gravity,  1-26;  ashes  per 
cent  1'2;  combustible  gases,  415;  coke,  68-6;  sulphur  1.  Another  specimen  had  a 
Bpeci'fic  gravity  of  1*244 ;  2  per  cent  of  ashes ;  385  of  combustible  gases ;  1  of  sulphur. 
This  is  a  very  good  coal  for  gas,  and  for  domestic  use. 

3.  The  Varley  Rock  Vein  Coal,  near  Pontypool ;  shipped  by  Mr.  John  Vipond. — 
Specific  gravity,  1-296;  ashes  (whitish)  5  per  cent;  32  of  combustible  gases;  68 
of  coke.    Sulphur  from  2  to  3  per  cent    A  good  household  coal. 

4.  The  Llangennech  Coal  has  a  well-established  reputation  for  the  production  of 
steam,  and  is  much  employed  by  the  British  government  for  steam  navigation,  as  well 
as  at  Meux's,  and  others  of  the  great  breweries  in  London.  It  affords  a  very  intense  heat, 
with  little  or  no  smoke  ;  and  sufiiciently  diffusive,  for  extending  along  the  flues  of  the 
boilers ;  whereas  the  anthracite  coal,  containing  very  little  hydrogen,  yields,  in  common 
circumstances,  a  heat  too  much  concentrated  under  the  bottom  of  the  boilers,  and 
acting  too  little  upon  their  sides.  Specific  gravity,  1-337 ;  intermediate  between  that 
of  the  Newcastle  and  the  anthracite.  Ashes  per  cent  from  3  to  3-35;  combustible 
gases,  17  ;  coke  83  ;  sulphur,  only  one  half  per  cent    It  is  therefore  a  pure  and  very 

powerful  fuel  ,    .      .  ,     ,  •  i  -  •      • 

I  have  examined  many  coals  with  my  calorimeter ;  of  which  some  account  is  given 

under  Fuel,  „    ,        ,  ^       ^   j-  j 

It  is  quite  susceptible  of  positive  proof  that  oy  no  arrangement  yet  discovered, 
3an  more  than  two-thirds  of  the  heat  generated  by  a  given  quantity  of  coal,  during 
combustion,  be  fairly   absorbed  and  utilised  in  any  of  our  manufactories ;    and, 
moreover,  there  are  undeniable  facts,  which  demonstrate  that  seldom,  in  the  burning  of 
coal,  are  more  than  thiee-fourths  of  the  total  heat,  which  might  be  eliminated,  actually 
obtained,  thus  justifying  the  supposition,  that  one  half  of  all  the  coal  now  consumed, 
is  virtually  wasted,  and  lost  to  society.     The  first  of  these  defects,  or  the  non-absorption 
of  heat  by  the  various  objects  exposed  to  the  action  of  fire,  has  pretty  largely  attracted 
the  attention  of  inventors ;  and,  within  the  last  twenty  years,  several  very  satisfactory 
improvements  have  been  produced,  especially  with  reference  to  steam-boilers.     For  the 
most  part  these  improvements  have  consisted  in  lengthening  the  flues,  and  exposing  a 
larger  surface  of  the  boiler  to  the  action  of  the  heated  air  passing  from  the  furnace  to  the 
chimney.     From  this  arrangement  a  vast  economy  of  fuel  has  resulted,  and  particularly 
from  that  form  of  setting,  known  under  the  term  "  Cornish  boiler  setting."     But  there 
is  yet  a  point  in  this  matter  which  requires  careful  investigation,  and  that  is  the  extent 
to  which  the  current  or  draught  in  such  flues,  ought  to  be  retarded,  so  as  to  favour  the 
transmission  of  heat  from  the  flue  to  the  interior  of  the  boiler.     Remembering  that  air 
is  an  extremely  bad  conductor  of  heat  and  that  water  about  to  become  converted  into 
steam  is  also  a  bad  conductor,  it  is  evident  that  time  must  form  an  important  element 
in  the  perfect  transmission  of  heat  from  one  of  these  to  the  other;  and  hence,  with  a 
great  velocity  of  current  existing  in  the  flues,  very  little  heat  would  pass  from  air, 
however  high  its  temperature,  to  water  contained  in  a  boiler,  and  so  circumstanced  in 
respect  to  its  all  but  gaseous  condition.     As  an  illustration  of  this  line  of  ai^ument  we 
may  adduce  the  case  of  gunpowder,  which,  although  forming  a  most  intense  heat  by 
its  combustion,  scarcely  warms  the  barrel  of  a  gun,  through  which  it  rushes  during  an 
explosion.     Here  the  barrel  of  the  gun  may  be  said  to  represent  the  flue,  the  force  of 
the  explosion  the  draught  and  the  gaseous  products  of  the  gunpowder  those  of  an 
ordinary  fire  during  combustion ;  yet  the  rapidity  with  which  the  heated  air  passes  is 
so  great  that  the  whole  caloric  effect  is  lost  and,  as  it  were,  thrown  into  the  chimney. 
In  corroboration  of  these  views  we  may  direct  attention  to  the  results  of  some 
experiments  on  fuel  made  at  the  Museum  of  Practical  Geology  by  Sir  H.  de  la  Beche 
and  Dr.  L.  Playfair,  and  which  clearly  show  that,  to  open  the  damper  of  a  steam-boiler 
furnace  is  pretty  generally  to  diminish  the  effective  power  of  the  fuel :  there  can,  in 
fact,  be  no  doubt  that  great  waste  of  coal  now  arises  from  inattention  to  this  simple 
circumstance  ;  and  that  much  of  the  heat  of  the  fire,  which  ought  to  go  to  the  boiler,  is 
lost  by  its  hasty  transmission  to  the  chimney.     I^  however,  there  be  thus  far  room  for 
improvement  in  the  direction  just  indicated,  still  wider  is  the  vacant  space,  caused  by 
imperfect  combustion,  or,  in  technical  phrase,  "  bad  stoking."     We  cannot  sufiiciently 
insist  upon  the  necessity  for  some  speedy  and  judicious  alterations  in  this  matter ;  and 
to  be  really  useful,  these  alterations  should  either  supersede  the  employment  of  a  stoker 
altogether,  or  render  negligence  on  his  part  capable  of  immediate  and  certain  detection. 
If  the  combustible  constituents  of  common  coal  be  regarded  as  composed  solely  of 
hydrogen  and  carbon,  and  the  heating  power  of  hydrogen  be,  as  is  represented,  three 
times  greater  than  that  of  carbon,  no  reasonable  bemg  can  fail  to  perceive  the  enormous 

312 


iiT* 


i 


P 


428 


PITCOAL. 


foUy  of  permitting  any  portion  of  the  hydrogenous  constituent  of  coal  to  escape  from 
the  furnace  unburnt ;  for  its  loss  imphes  the  waste  of  three  times  its  weight  of  the  soUd 
or  carbonaceous  constituent     Nevertheless,  so  uniform  and  systematic  hts  the  waste  of 
hydrogen  become  from  the  prevalence  of  bad  stoking,  that  several  eminent  engineers, 
unacquainted  with  the  real  facts  of  the  case,  have  come  to  regard  the  calorific  value  of 
a  coal  as  proportioned  only  to  the  carbon  it  contains ;  thus  attributing  no  heating  power 
whatever  to  the  hydrogen  ;  and  this  too  in  the  face  of  the  circumstanci,  that  the  common 
gas  «f«ur  streets  is  largel}^  used  for  cooking  purposes,  and  yields,  weight  for  weight, 
more  than  double  the  quantity  of  heat  given  out  by  either  coke  or  charcotl !    As  usually 
employed,  fully  one  half  of  the  hydrogen  of  bituminous  coal  passes  unconsumed  uS 
the  chimney,  merely  because  the  stoker,  to  economize  his  labour,  and  avoid  trouble 
throws  on  to  the  bars  of  his  furnace  a  thick  layer  of  fuel ;  by  which  loss  is  caused  in  two 
or  three  directions.     In  the  first  place,  as  no  atmospheric  air  can  force  its  way  through 
the  heap,  a  process  of  distillation  takes  place  from  the  upper  surface  of  the  carbonaceous 
mass,  exactly  as  happens  m  a  gas  retort ;  and  when  the  whole  of  the  volatile  matters 
have  been  thus  driven  oflF,  and  not  before,  the  residuary  cinder  or  coke  enters  into  com- 
bustion.    No  wonder,  then,  that  practical  men  have  arrived  at  the  conclusion,  that  this 
coke  fairlv  represents  the  value  of  the  coal ;  for,  as  we  have  seen,  combustion  begins  only 
when  nothing  else  is  left.     But  the  loss  of  the  hydrogen  is  not  the  only  waste  consequent 
upon  throwing  too  much  coal  at  once  upon  the  fire-bars.     Dr.  Kennedy  lone  ago  proved 
that  the  hottest  part  of  a  furnace  is  about  one  inch  above  the  fire-bars,  for  there  perfect 
combustion  goes  on  and  the  carbon  consumed  is  converted  into  carbonic  acid,  with  the 
total  evolution  of  all  its  heat     But,  let  us  imagine  a  mass  of  red-hot  coke  or  cinder, 
two  or  three  inches  tliick,  lying  above  the  carbonic  acid  thus  produced,  and  through 
which,  consequently,  it  must  pass,  to  communicate  its  heat  to  the  boiler  or  chimney. 
In  passing  over  this  red-hot  coke,  the  carbonic  acid  would  be  converted  into  carbonic 
oxide,  and  thus  not  only  remove  a  quantity  of  carbon  equal  to  its  own,  without  yielding 
any  additional  heat  but  actually  with  the  production  of  cold,  or,  in  other  words,  the 
absorption  of  heat ;  for  the  volume  of  carbonic  oxide,  engendered  in  this  manner,  is 
double  of  that  of  the  carbonic  acid  originally  formed  ;  and  hence  this  expansion  must  be 
accompamed  by  the  disappearance  of  heat,  which  becomes  latent  in  the  carbonic  oxide 
Here  then  are  three  distinct  sources  of  waste,  consequent  upon  this  single  mal-practice ' 
which  however  entails,  as  a  necessary  sequence,  the  production  of  loss  from  a  different 
cause-^As  by  heapmg  a  large  quantity  of  he]  upon  the  furnace-bars,  a  stoker  is  enabled 
to  neglect,  with  impumty,  his  duty  for  many  mmutes,  so  it  frequently  happens  that  this 
neglect  is  continued,  until  portions  of  the  fire-bars,  becoming  uncovered  with  fuel,  permit 
the  ingress  of  cold  air  m  a  large  quantity  through  these  openings  ;  and  thus  not  only  i» 
the  combustion  of  the  remainmg  coal  retarded  by  this  mis-direction  of  the  draught  but 
the  aggregate  temperature  of  the  whole  furnace  is  vastly  diminished.     Now  we  can 
scarcely  conceive  a  more  tempting  or  a  more  promising  field  of  inquiry  than  is  opened 
out  m  the  great  question.  How  are  these  evils  to  be  eftectually  got  rid  of  ?     Tl)oiisand8 
of  mdividuals  m  this  country  have  the  means  daily  in  their  hands  of  making  practical 
experiments  upon  this  subject ;  but  they  are  not,  perhaps,  even  aware  that  such  evils 
exist     Let  us  hope  then  that  some  few  of  these  persons  may  be  roused  into  a  state  of 
useful  activity,  and  that  the  advent  of  another  Exhibition  may  be  preceded  by  some 
invention,  capable  of  counteracting  this  great  national  loss.    It  is,  beyond  all  others,  a 
problem  within  the  domain  of  the  humblest  working  man.     Before  quitting  the  article 
coa;  we  feel  that  a  few  observations  on  the  present  modes  of  estimating  the  value  of 
that  substance,  in  a  commercial  point  of  view,  are  called  for 

In  the  mvestigation  undertaken  at  the  Museum  of  Economic  Geology,  three  different 

fnH  w^r^^?'     T^  ^^""^^'^ '  ^^  ""^^^^  ^^  ^^^^^'  J^^^^^g  V  ^^^  '««"^^  ««^"»  defective 
and  worthless.     1  he  experiments  were  meant  to  have  spedaf  reference  to  the  boilers  of 

marine  engines,  yet  those  made  have  been  upon  a  Cornish  boiler,  set  after  the  Cornish 
fashion.  Independently,  therefore,  of  the  fact  that  the  results  thus  obtained  are,  to  the 
Jr.  fe?;  hT^^fr^J  ^°^  discrepant,  they  furnish  no  guide  by  which  to  judge  of 
the  effects  that  might  follow  when  a  marine  boiler  is  used.  ^  Of  the  two  other  methods. 

mLIX^T  '\v*^'?^f^°  "^^^^^^^^  *°*^^«^«  **^^^^  <^««1  ^y  Peroxide  of  copper ;  X 
^nnf  Zl^liVu  '^^  ""^  ^'^^^'^"  "*P^^^"  ^^  ^^^S  reduced  iy  a  given  weight  of  Se 
coaL  Both  of  these  processes  seem  to  have  been  conducted  on  by  far  too  smalU  quantity 
of  matter  to  yield  a  result  worthy  of  confidence  ;  for  but  H  grains  of  coal  werTtaken 
on  an  average,  for  ultimate  analysis,  and  only  6  ^ains  for  the  litharge  assay.  The  eiroS 
of  manipulation  are,  therefore,  relatively  excessfve ;  and,  as  a  consequent  result^  we  find 
these  methods  contradicting  each  other,  to  something  like  16  or  16  per  cent,-as  a 
careful  examination  of  the  parliamentary  report  will  prove.  For  the  sake  of  illustration 
we  select,  at  random,  from  samples  of"  coal  thus  treated,  merely  premising  that  the 
amount  of  lead  produced  from  the  ultimate  analysis  was  found  by  estimating  the  atoms 
Of  lead,  carboD,  oxygen,  and  hydrogen,  respectively,  at  the  nuibers  104,  6,  8  and  1 


PITCOAL. 


429 


Thus  calculated,  we  have  the  following  discordant  figures  given  by  the  two  methods 
in  question,  which,  it  is  needless  to  say,  present  differences  greater  than  can  possibly 
exist  between  any  two  kinds  of  coal  whatever:  — 


,,         ,  ( Bates'  Hartley 

Newcastle  coals,  j  Hastings'  do. 

Welsh  coal.  Lynvi     - 

Lancashire  coaL  Laffak 


By  Litharge. 

144-6 

142-8 

161-2 

•      134-4 


By  Analysis. 
162-8 
166-4 
175-8 
163-8 


Difference. 
18-2 
23-6 
14-6 

29-4 


Thus  Bates'  Hartley,  which  by  the  litharge  essay  is  better  than  the  Hastings  Hart- 
ley and  Laffak,  turns  out,  from  the  ultimate  analysis,  worse  than  either  of  them.  We 
deem  it  useless  to  pursue  this  subject  further,  enough  having  been  shown  to  prove  the 
utter  inadequacy  of  the  means  now  employed  for  ascertaining  the  calorific  value  of 
coal.  The  most  likely  method  of  effecting  this  object  would  be  to  burn  a  given  weight 
of  each  coal  in  a  vessel  filled  with  pure  oxygen  ps,  and  surrounded  by  a  large  body 
of  cold  water ;  ignition  being  commenced  by  a  fine  platinum  wire,  heated  through  the 
agency  of  a  galvanic  battery.  Some  experiments  made  in  this  way,  for  a  special  pur- 
pose, have  given  the  most  unifonn  and  satisfactory  results. 

The  only  manufactured  articles  made  from  coal  are  coke  and  coal-gas.  The  burning 
of  coke  resolves  itself  into  two  objects ;  and,  as  neither  of  these  are  gained  by  gas 
manufacturers,  it  becomes  necessary  to  distinguish  between  what  is  called  gas-coke  and 
oven-coke.  The  word  coke  applies,  properly,  to  the  latter  alone ;  for  in  a  manufacturing 
sense,  the  former  is  merely  cinder.  The  production  of  good  coke  requires  a  combination 
of  qualities  in  coal  not  very  frequently  met  with ;  and  hence  first-rate  coking  coals  can 
be  procured  only  from  cei-tain  districts.  The  essential  requisites  ar^  first,  the  presence 
of  very  little  earthy  or  incombustible  ash  ;  and,  secondly,  the  more  or  less  infusibility  of 
that  ash.  The  presence  of  any  of  the  salts  of  lime  is  above  all  objectionable,  after  which 
may  be  classed  silica  and  alumina ;  for  the  whole  of  these  have  a  strong  tendency  to 
produce  a  vitrification,  or  slag,  upon  the  bars  of  the  furnace  in  which  the  coke  is  burnt ; 
and  in  this  way  the  bars  are  speedily  corroded  or  burnt  out ;  whilst  the  resulting  clinker 
impedes  or  destroys  the  draught,  by  fusing  over  the  interstices  of  the  bars  or  air  passages. 
Iron  pyrites  is  a  common — but,  except  in  large  quantities,  not  a  very  serious — obstacle 
to  the  coke  maker:  for  it  is  found  in  practice,  that  a  protracted  application  of  heat  in 
the  oven  dissipates  the  whole  of  the  sulphur  from  the  iron,  with  the  production  of 
bisulphuret  of  carbon  and  metallic  carburet  of  iron, — the  latter  of  which  alone  remains 
in  the  coke,  and,  unless  silica  be  present  has  no  great  disposition  to  vitrify  after  oxidation- 
One  object,  therefore,  gained  by  the  oven  coke  manufacturer  over  the  gas  maker,  is  the 
expulsion  of  the  sulphuret  of  carbon,  and  consequent  purification  of  the  residuary  coke. 
Another,  and  a  still  more  important  consequence  of  a  Ictog  sustained  and  high  heat  is, 
the  condensation  and  contraction  of  the  coke  into  a  smaller  volume,  which,  therefore, 
permits  the  introduction  of  a  much  greater  weight  into  the  same  space  ;  an  advantage 
of  vast  importance  in  blast  furnaces,  and,  above  all,  in  locomotive  engines,  as  the  re- 
peated introduction  of  fresh  charges  of  coal  fuel  is  thus  prevented.  Part  of  this  con- 
densation is  due  to  the  weight  of  the  superincumbent  mass  of  coal  thrown  into  the  coke 
oven,  by  which  (when  the  coal  first  begins  to  cake  or  fuse  together)  the  particles  are 
forced  towards  each  other,  and  the  cavernous  character  of  cinder  got  rid  of;  but  the 
chief  contraction  arises,  as  we  have  said,  from  the  natural  quality  of  carbon,  which,  like 
alumina,  goes  on  contracting,  the  longer  and  higher  the  heat  to  which  it  is  exposed. 
Hence,  good  coke  cannot  be  made  in  a  short  time,  and  that  used  in  locomotive  engines 
is  commonly  from  48  to  96,  or  even  120  hours  in  the  process  of  manufacture. 

The  prospects  of  improvements  in  coke-making  seem  not  very  great,  and  point  rather 
to  alterations  in  the  oven  than  in  the  process ;  nor  does  it  seem  possible  to  utilize  the 
heat  evolved  by  the  gaseous  constituents  of  the  coal ;  for  this  heat,  though  large  in 
quantity,  is  of  trifling  intensity,  and,  consequently,  admits  of  but  a  restricted  use  in  the 
arts ;  moreover,  the  incessant  variations  to  which  it  is  subject,  according  to  the  period 
of  manufacture,  still  further  interfere  with  its  employment,  even  where  great  intensity 
of  fire  is  not  needed,  as  in  steam  boilers,  for  example.  Nevertheless,  there  appears  no 
valid  reason  why  sets  of  coke  ovens  might  not  be  so  arranged  as  mutually  to  compen- 
sate for  each  other,  and  produce  upon  one  particular  flue  a  constant  and  uniform  effect 
Contrivances  of  this  kind  have  been  projected, — but  hitherto,  we  may  suppose,  without 
success,  as  our  largest  coke  makers  still  continue  the  old  mode  of  working. 

The  process  of  gas  making  from  coal  is  in  itself  so  large  and  singular  an  operation, 
and  has,  besides,  such  a  variety  of  connections  with  other  branches  of  industry,  that, 
though  its  details  and  possible  improvements  might  very  correctly  follow  upon  an 
analysis  of  the  coke  maker's  art,  yet  we  prefer  to  treat  of  it  amongst  tfie  more  advanced 
and  scientific  manufactures,  rather  than  associate  its  comprehensive  traits  of  civilized 
skill  with  the  rough  and  ready  exigencies  of  "  raw  material "  incidental  to  this  early 


mnik 


430 


HTCOAL. 


PITCOAL. 


481 


stage  of  our  progress.  Vfe  feel,  too,  that  the  introduction  of  such  a  subject  here 
would,  m  some  degree,  break  the  geological  connection  which  exists  between  coal  and 
iron,— a  connection,  by  the  bye,  equally  remarkable  in  a  mercantile  aspect. 

An  account  of  the  nature  and  extent  of  the  various  deposits  of  mineral  fud  in  various 
parts  of  the  world.  Accompanied  by  a  map  showing  the  extent  andmsition  of  the  prin- 
cipal coal  fields  of  Europe  and  North  America.  By  D.  T.  Ansted,  M.  A.  F.  R.  S.  Ac, 
Prof.  Geol,  K.  C.  L.  General  account  of  materials  used  for  fuel. — ^The  chief  supplies 
of  valuable  fuel  are,  and  always  have  been,  derived  immediately  or  distinctly  from  the 
vegetable  kindom.  Whether  in  the  form  of  wood,  peat,  lignite,  or  coal  of  various 
kinds,  the  original  substance  of  all  fuel  has  been  found  to  have  this  origin,  and  thus  it 
would  seem  that  the  power  of  vitality  exerted  in  producing  woody  fibre  has  been 
from  time  to  time  stored  up,  as  it  were,  into  vast  reservoirs  where  it  might  be  preserv- 
ed safely  and  permanently  for  an  indefinite  period. 

In  warm  climates,  where  the  growth  of  vegetation  is  extremely  rapid  and  compara- 
tively little  fuel  is  needed,  or  in  early  periods  of  civilization  before  men  congregate  in 
large  masses  in  towns,  or  are  actively  employed  in  manufacture,  there  is  little  need  of 
more  fuel  than  is  supplied  by  the  natural  growth  of  forests;  but  under  other  circum- 
stances where  forests  are  gradually  removed,  and  the  consumption  of  fuel  at  the  same 
time  increases,  the  reserved  stores  are  greatly  needed  and  must  ultimately  be  reckon- 
ed among  the  main  sources  of  a  country's  wealth.  The  accumulation  of  mineral  fuel 
m  the  British  islands  may  be  ranked  as  one  of  those  natural  advantages  without  which 
our  country  could  not  possibly  have  taken  up  and  held  for  a  long  time  the  position 
she  occupies  among  the  nations  of  the  earth :  and  thus,  as  one  of  the  great  and  prin- 
cipal sources  of  its  minei-al  treasure,  the  coal  deposits  of  England  demand  and  deserve 
our  careful  attention.  The  relative  supply  of  other  countries,  and  the  activity  and 
energy  displayed  in  taking  advantage  of  the  existence  of  mineral  fuel,  must  also  be 
worthy  of  attention,  as  illustrating  and  explaining  the  condition  of  many  manufac- 
tures, and  probable  advance  of  the  inhabitants  of  such  districts  in  the  refinements  of 
civilization.  Since  the  introduction  of  steam  power  for  all  purposes  of  machinery,  the 
consumption  of  coal  has  very  greatly  increased,  and  at  present  it  would  be  difficult  to 
set  any  limits  to  the  use  of  so  valuable  a  material. 

The  changes  undergone  by  vegetable  matter  when  buried  in  the  earth,  and  accumu- 
lated m  large  quantities,  and  the  length  of  time  needed  to  produce  any  marked 
alteration,  are  subjects  rather  more  interesting,  it  may  seem,  to  the  chemist  tban  to  the 
practical  man,  who  looks  only  for  fuel  that  he  may  employ  economically.  But  inas- 
much as  the  real  condition  of  coal  varies  considerably,  and  diflFerent  kinds  are  valua- 
ble for  different  purposes,  it  is  desirable  that  the  whole  history  of  coal  and  lignite  beds, 
and  of  peat  and  turf;  should  be  generally  understood  by  any  one  using  any  or  all  of 
these  substances  extensively. 

Vegetable  matter  consists  of  particles  of  carbon  with  minute  proportions  of  several 
other  elements  arranged  round  minute  cavities  or  cells,  many  of  these  being  mechani- 
cally connected  to  form  the  varieties  of  vegetable  fibre.  A  large  quantity  of  water  is 
also  present^  and  so  long  as  the  vegetable  lives,  there  is  a  constant  change  of  circula- 
tion of  material  particles  kept  up  replacing  and  renewing  the  different  portiona 
When  death  takes  place,  there  is  a  tendency  to  decomposition,  or  the  separation  of 
the  whole  into  minute  atoms  having  no  further  relation  to  each  other.  But  this  is 
frequently  checked  by  various  conditions,  such  as  the  presence  of  some  substances  de- 
rived from  plants  themselves,  or  the  absence  of  sufficient  oxygen  gas  to  allow  the 
change  to  take  place  by  mixing  with  the  carbon  and  becoming  carbonic  acid  gas,  the 
first  step  in  the  process  of  destruction.  These  causes  act  constantly  but  partially,  and 
thus  a  large  quantity  of  vegetable  matter  is  always  in  the  course  of  decomposition, 
while  in  particular  spots  a  large  quantity  is  constantly  being  accumulated.  The 
latter  condition  is  seen  in  our  climate  in  the  gradual  but  steady  increase  of  peat 
bogs.     The  former  is  too  common  to  require  further  notice. 

2.  Peat  and  T^m?/.— Accumulations  of  vegetable  matter  may  be  chiefly  composed 
either  of  succulent  vegetation,  grasses,  or  marsh  plants,  or  of  trees,  and  the  structure 
and  condition  of  woody  fibre  is  well  known  to  be  very  different  from  that  of  grasses 
and  succulent  plants.  There  are  thus  two  very  distinct  kinds  of  material  preserved, 
the  one  undergoing  change  much  less  rapidly  than  the  other,  and  perhaps  much  less 
completel3^  It  is  easily  proved  that  from  the  accumulation  of  forest  trees  has  been 
obtained  the  imperfect  coal  called  lignite,  while  from  marsh  plants  and  grasses  mixed 
occasionally  with  wood  we  obtain  peat  turf  and  bog.  All  these  substances  consist 
to  a  great  extent  of  carbon,  the  proportions  amounting  to  from  50  to  60  per  cent, 
and  being  generally  greater  in  lignite  than  in  turf.  On  the  other  hand,  the  propor 
tion  of  oxygen  gas  is  generally  very  much  greater  in  turf  than  in  lignite.  The  pro 
portion  oi  ash  is  too  variable  to  be  worth  recording,  but  is  generally  sufficiently 
large  to  injure  the  quality  of  the  fuel 


As  a  very  large  quantity  of  turf  exists  in  Ireland,  covering,  indeed,  as  much  as  one 
seventh  part  of  the  island,  the  usual  and  important  practical  condition  of  this  substance 
can  be  best  illustrated  by  a  reference  to  that  country.     This  will  be  understood  by 
the  following  account  of  its  origin,  abstracted  from  the  "  Bog  Report"  of  Mr.  Nimmo. 
He  says,  referring  to  cases  where  clay  spread  over  gravel  has  produced  a  kind  of 
puddle  preventing  the  escape  of  waters  of  floods  or  springs,  and  when  muddy 
pools  have  thus  been  formed,  that  aquatic  plants  have  gradually  crept  in  from 
the  borders  of  the  pool  towards  their  deep  centre.     Mud  accumulated  round  their 
roots  and  stalks,  and  a  spongy  semi-fluid  was  thus  formed,  well  fitted  for  the  growth  of 
moss,  which  now  especially  spears  Sph.aynum  began  to  luxuriate ;  this  absorbing  a  lai-ge 
quantity  of  water,  and  continuing  to  shoot  out  new  plants  above,  while  the  old  were 
decaying,  rotting  and  compressing  into  a  solid  substance  below,  gradually  replaced  the 
water  by  a  mass  of  vegetable  matter.     In  this  manner  the  mareh  might  be  filled  up 
while  the  central  or  moister  portion,  continuing  to  excite  a  more  rapid  growth  of  the 
moss,  it  would  be  gradually  raised  above  the  edges,  until  the  whole  surface  had  attained 
an  elevation  sufficient  to  discharge  the  surface  water  by  existing  channels  of  drainage, 
and  calculated  by  its  slope  to  facilitate  their  passage,  when  a  hmit  would  be,  in  some 
degree,  set  to  its  further  increase.     Springs  existing  under  the  bog  or  in  its  immediate 
vicinity,  might  indeed  still  favour  its  growth,  though  in  a  decreasing  ratio ;  and  here  if 
the  water  proceeding  from  them  were  so  obstructed  as  to  accumulate  at  its  base,  and  to 
keep  it  in  a  rotten  fluid  state,  the  surface  of  the  bog  might  be  ultimately  so  raisec^  and 
its  continuity  below  so  totally  destroyed,  as  to  cause  it  to  flow  over  the  retainmg 
obstacle  and  flood  the  adjacent  country.     In  mountain  districts  the  progress  of  the 
phenomenon  is  similar.     Pools  indeed  cannot  in  so  many  instances  be  formed,  the 
steep  slopes  facilitating  drainage,  but  the  clouds  and  mists  resting  on  the  summits  and 
sides  of  mountains  amply  supply  their  surface  with  moisture,  which  comes,  too,  in  the 
most  favourable  form  for  vegetation,  not  in  a  sudden  torrent,  but  unceasmgly  and 
gently  drop  by  drop.     The  extent  of  such  bogs  is  also  affected  by  the  nature  of  the 
rocks  below  them.     On  quartz  they  are  shallow  and  small;  on  any  rock  yielding  by 
its  decomposition  a  clayey  coating  they  are  considerable ;  the  thickness  of  the  bog 
(for  example  in  Knocklaid  in  the  county  of  Antrim,  which  is  168  feet  high),  being 
nearly  12  feet.     The  summit  bogs  of  high  mountains  are  distinguishable  from  those  of 
lower  levels  by  the  total  absence  of  large  trees. 

As  turf  includes  a  mass  of  plants  in  different  stages  of  decomposition,  its  aspect  and 
constitution  vary  very  much.  Near  the  surface  it  is  light-coloured,  spongy,  and  contains 
the  vegetable  matter  but  littie  altered ;  deeper,  it  is  brown,  denser,  and  more  decom- 
posed ;  and  finally  at  the  base  of  the  greater  bogs,  some  of  which  present  a  depth  of  40 
feet,  the  mass  of  turf  assumes  the  black  colour  and  nearly  the  density  of  coal,  to  wHich 
also  it  approximates  very  much  in  chemical  composition.  The  amount  of  ash  contained 
in  turf  IS  also  variable,  and  appears  to  increase  in  proportion  as  we  descend.  Thus,  in 
the  section  of  a  bog  40  feet  deep  at  Tunahoe,  those  portions  near  the  surface  contained 
1^  per  cent,  of  ashes,  the  centre  portions  3i  per  cent,  whilst  the  lowest  4  feet  of  turf 
contained  19  per  cent  of  ashes.  In  the  superficial  layers,  it  may  also  be  remarked,  that 
the  composition  is  nearly  the  same  as  that  of  wood,  the  vegetable  material  being  lost^ 
and  in  the  lower  we  find  the  change  into  coal  nearly  complete.  Notwithstanding 
these  extreme  variations,  we  may  yet  establish  the  ordmary  constitution  of  tur^  and 
with  certainty  enough  for  practical  use,  and  on  the  average  specimens  of  turf  selected 
from  various  localities,  the  following  results  have  been  obtained : — 

The  calorific  power  of  dry  turf  is  about  half  that  of  coal ;  it  yields  when  ignited  with 
lead,  about  14  times  its  weight  of  lead.  This  power  is  however  immensely  diminished  in 
ordinary  use  by  the  water  which  is  allowed  to  remain  in  its  texture,  and  of  which  the 
spongy  character  of  its  mass  renders  it  very  difficult  to  get  rid  ofc  There  is  nothing 
which  requires  more  alteration,  than  the  collection  and  preparation  of  turf;  indeed,  for 
practical  purposes,  this  valuable  fuel  is  absolutely  spoiled  as  it  is  now  prepared  in 
Ireland.  It  is  cut  In  a  wet  season  of  the  year;  whilst  drying  it  is  exx^sed  to  the 
weather ;  it  hence  is  in  reality  not  dried  at  alL  It  is  very  usual  to  find  the  turf  of  com- 
merce containing  one-fourth  of  its  weight  of  water,  although  it  then  feels  dry  to  the 
hand.  But  let  us  examine  what  affects  the  calorific  power.  One  pound  of  pure  dry 
turf  will  evaporate  6  lbs.  of  water ;  now,  in  1  lb.  of  turf  as  usually  found,  there  are  J  lb. 
of  dry  turf;  and  li  lbs.  of  water.  The  \  lb.  can  only  evaporate  4^  lbs.  of  water ;  but  out 
of  this  it  must  first  evaporate  the  \  lb.  contained  in  its  mass,  and  hence  the  water  boiled 
away  by  such  turf  is  reduced  to  4^  lbs.  The  loss  is  here  30  per  cent,  a  proportion  which 
makes  all  the  difference  between  a  good  fuel  and  one  almost  unfit  for  use.  When  turf 
is  dried  in  the  air  under  cover  it  still  retains  one  tenth  of  its  weight  of  water,  which 
reduces  its  calorific  power  12  per  cent,  1  lb.  of  such  turf  evaporating  6^  lbs.  of  water. 
This  effect  is  sufficient,  however,  for  the  great  majority  of  objects;  the  further  desicca- 
tion is  too  expensive,  and  too  troublesome  to  be  used,  except  in  special  cases. 


432 


PITCOAL. 


PITCOAL. 


433 


/•■ 


The  characteristic  fault  of  turf  as  a  fuel  is  its  want  of  density,  which  renders  it  diffi- 
eult  to  concentrate  within  a  limited  space  the  quantity  of  heat  necessary  for  many 
operations.  The  manner  of  heating  turf  is  indeed  just  the  opposite  to  anthracite.  The 
turf  yields  a  vast  body  of  volatile  inflammable  ingredients,  which  pass  into  the  flues  and 
chimney,  and  thus  distribute  the  heat  of  combustion  over  a  great  space,  whilst  in  no 
one  point  is  the  heat  intense.  Hence  for  aU  flaming  fires  turf  is  applicable,  and  in  its 
application  to  boilers,  it  is  peculiarly  useful,  as  there  is  no  liability  to  that  burning  away 
of  the  metal,  which  may  arise  from  the  local  intensity  of  coke  or  coal.  If  it  be  required. 
It  is  quite  possible,  however,  to  -obtain  a  very  intense  heat  with  turf 

The  removal  of  porosity  and  elasticity  of  turf,  so  that  it  may  assume  the  solidity  of 
coal,  has  been  the  object  of  many  who  have  proposed  mechanical  and  other  processes 
for  the  purpose.  It  has  been  found  that  the  elasticity  of  the  turf  fibre  presents  great 
obstacles  to  compression,  and  the  black  tur^  which  is  not  fibrous,  is  of  itself  sufl^cientlv 
dense.  ^ 

Not  merely  may  we  utilize  turf  in  its  natural  condition,  or  compressed  or  impregnated 
pitchy  matter,  but  we  may  carbonize  it^  as  we  do  wood,  and  prepare  turf  charcoal,  the 
properties  of  which  it  is  important  to  establish:—!.  By  heating  turf  in  close  vessels; 
5^4.*i/^j™°^^  ^^^^  ^^  avoided,  but  it  is  expensive,  and  there  is  no  compensation  in  the 
distilled  liquors,  which  do  not  contain  acetic  acid  in  any  quantity.  The  tar  is  often 
small  m  proportion,  hence  the  charcoal  is  the  only  valuable  product  Its  quantity 
vanes  from  30  to  40  per  cent,  of  dry  turf  The  products  of  the  distillation  of  1,157 
lbs.  of  turf  were  found  by  Blavier  to  be  charcoal,  474  lbs.,  or  41  per  cent ;  watery 
liquid  226  lbs.,  or  19-3  per  cent ;  gaseous  matter  460  lbs.,  or  39  per  cent ;  and  tar  7 
lbs.,  or  6  per  cent ;  but  the  proportion  of  tar  is  variable,  sometimes  reaching  24*6  per 
cent,  when  the  turf  is  coked  in  close  vessels. 

The  economical  carbonization  of  turf  is  best  carried  on  in  heaps,  in  the  same  manner 
as  that  of  wood.  The  sods  must  be  regularly  arranged,  and  laid  as  close  as  possible; 
thev  are  the  better  for  being  large,  16  inches  long,  by  6  broad,  and  5  deep.  The  heaps 
bmlt  hemispherically  should  be  smaller  in  size  than  the  heaps  of  wood  usually  are.  In 
general  6,000  or  6,000  large  sods  may  go  to  the  heap,  which  will  thus  contain  1,500 
cubic  feet  The  mass  must  be  allowed  to  heap  more  than  is  necessary  for  wood, 
and  the  process  requires  to  be  very  carefully  attended  to,  from  the  extreme  combusti- 
bility of  the  charcoal.  The  quantity  of  charcoal,  obtained  in  this  mode  of  carboniza- 
tion, is  from  25  to  30  per  cent  of  the  weight  of  dry  turf 

^  For  many  industrial  uses  the  charcoal  so  prepared  is  too  light,  as,  generally  speaking, 
it  is  only  with  fuel  of  considerable  density,  that  the  most  intense  heat  can  be  produced, 
but  by  coking  compressed  tur^  it  has  already  been  shown,  that  the  resulting  charcoal 
may  attain  a  density  of  1,040,  which  is  far  superior  to  wood  charcoal,  and  even  equal 
to  that  of  the  best  coke  made  from  coal.  As  to  calorific  eflfects,  turf  charcoal  is  about 
the  same  as  coal  coke,  and  little  inferior  to  wood  charcoal. 

It  is  peculiarly  important^  in  the  preparation  of  the  charcoal  from  turf,  that  the  ma- 
terial should  be  selected  as  free  as  possible  from  earthy  impurities,  for  all  such  are  con- 
centrated in  the  coke,  which  may  be  thereby  rendered  of  little  comparative  value. 
Hence,  the  coke  from  surface  turf  contains  less  than  10  per  cent  of  ash,  whilst 
that  of  dense  turf  of  the  lower  strata  contains  from  20  to  30  per  cent  This  latter 
quantity  might  altogether  unfit  it  for  practical  purposes. 

Nature  and  Distribution  of  6W/.— True  coal  is  so  little  altered  from  its  original 
vegetable  condition  as  to  have  left  scarcely  any  trace  of  its  true  history.  It  is  generally, 
however,  associated  with  sands  and  clays,  exhibiting  numerous  fragments  of  the  ancient 
vegetation  that  obtained  at  the  time  of  its  formation ;  but  these  fragments  are  so  far 
removed  in  every  respect,  from  the  existing  form  of  vegetation,  as  to  afford  little  clue  to 
the  ancient  condition  of  the  earth  in  this  respect  In  coal  all  trace  of  true  woody  fibre 
has  disappeared ;  the  water  originally  present  and  so  injurious  in  the  less  altered  forms 
of  vegetable  fuel,  is  entirely  absent,  or,  if  present  at  all,  is  so  rather  mechanically  than 
chepQically,  while  the  water  originally  in  the  plant  appears  to  have  undergone  decom- 

Eosition,  the  hydrogen  uniting  with  some  part  of  the  carbon,  to  form  carburetted 
ydrogen  gas  often  existing  in  the  cells,  and  between  the  plates  of  the  coal  under 
considerable  pressure,  and  the  oxygen  being  almost  entirely  removed.  The  former 
vegetable  has  now  become  a  mineral  substance,  and  lies  in  vast  beds  of  variable  thickness, 
and  overlaying  each  other  to  the  extent  sometimes  of  more  than  a  hundred  in  a  single 
district ;  such  beds  being  regularly  interstratified  with  deposits  of  sand  and  clay,  and 
occupying  a  distmct  geological  position,  being,  with  only  a  few  exceptions,  confined  to 
rocks  belonging  to  the  newer  part  of  the  palaeozoic  series. 

Between  the  Arctic  Circle  and  the  Tropic  of  Cancer  repose  all  the  principal  carboni- 
ferous formations  of  our  planet  Some  detached  coal  deposits,  it  is  true,  exist  above 
and  below  these  limits,  but  they  appear,  so  far  as  we  know,  to  be  of  limited  extent 
Many  of  these  southern  coal-fields  are  of  doubtful  geological  age ;  a  few  are  supposed 


to  approximate  to  the  class  of  true  coals,  as  they  are  commonly  styled,  others  are  de- 
cidedly of  the  brown  coal  and  tertiary  period,  while  the  remainder  belong  to  variom 
intermediate  ages,  or  possess  peculiar  characters  which  render  them  of  doubtful  geolo- 
gical origin. 

The  coals  of  Melville  Island  and  Byam  Martin's  Island  certainly  appear  to  be  of  the 
true  coal  period.  We  know  that  coal  exists  at  numerous  intermediate  points,  from  the 
75th  to  the  25th  degree  of  north  latitude  in  America,  and  abo  that  it  is  worked  on  the 
Sulado  and  Rio  Grande  rivers  in  Mexico  for  the  use  of  the  steamers. 

Southward  of  the  Tropic  of  Cancer  the  existence  of  coal  corresponding  Avith  the 
European  and  American  hard  coal  is  somewhat  uncertain.  There  seems  to  be  none  on 
the  South  American  continent,  unless  it  be  at  Ano  Paser,  which  needs  confirmation,  or 
in  the  province  of  Santa  Catharina  in  Brazil.  On  the  African  continent  we  have  had 
vague  accounts  of  coal  in  Ethiopia  and  at  Mozambique,  also  at  Madagascar,  and  quite 
recently  we  have  had  intelligence  of  large  quantities  of  coal  in  the  newly  ceded  territory 
above  Port  Natal,  on  the  eastern  side  of  Africa,  but  we  believe  no  geologist  has  examined 
these  sites.  In  the  Chinese  and  Burmese  empires  only  brown  coal  appears- to  approach 
the  Tropic,  but  true  coal  seems  to  exist  in  the  northern  provinces.  Southward  of  the 
Asiatic  continent  we  are  uncertain  of  the  exact  character  of  the  coal  deposits,  such  at 
occur  abundantly  at  Sumatra,  Java,  and  Borneo,  and  neighbouring  islands.  Coal,  how- 
ever, exists  in  these  islands,  and  is  of  a  fair  workable  quality. 

In  New  South  Wales  the  great  coal  range  on  the  eastern  mai^in  of  that  continent 
has  sometimes  been  described  as  resembling  the  Newcastle  coal  in  England,  and  some- 
times it  is  described  as  of  more  ancient  date.  This  coal  differs  essentially  from  that  of 
any  known  European  formation,  but  bears  a  strong  resemblance  to  the  Burdwan  coal 
of  India. 

We  have  not  3'et  arrived  at  the  period  when  we  could  pronounce  with  any  approach 
to  certainty  on  the  actual  number  of  coal  basins  in  the  world;  the  total  number  mus^ 
however,  amount  at  least  to  from  250  to  300  principal  coal  fields,  and  many  of  these  are 
subdivided  by  the  disturbed  position  of  the  strata  into  subordinate  basins. 

The  basins  or  coal  districts  are,  however,  grouped  into  a  comparatively  small  number 
of  districts,  and  even  many  of  these  are  little  known  and  not  at  all  measured.  The 
greater  number  occur  in  Western  Europe  and  Eastern  North  America,  while  Central 
and  Southern  Africa,  South  America,  and  a  large  part  of  Asia,  are  totally  without  any 
trace  of  true  carboniferous  rocks.  The  remarks,  therefore,  that  will  follow,  chiefly  refer 
to  our  own  and  adjacent  countries,  or  of  the  United  States  and  British  North  America. 

There  are  various  kinds  of  coal  obtained  from  mines  worked  in  the  true  coal  fielder 
which  may  be  grouped  into  bituminous,  steam-coal,  and  anthracite.  Of  the  first,  the 
cannel  is  a  remarkable  variety,  the  coarser  kinds  of  it  being  called  in  Scotland  "  parret^* 
and  sometimes  splintcoaL  It  contains  from  40  to  nearly  60  per  cent  of  volatile  matter, 
and  the  proportion  of  carbon  varies  within  the  same  limits.  It  burns  readily,  taking 
fire  like  a  candle,  and  giving  a  bright  light  and  much  smoke.  The  ash  varies  fr*om 
4  to  10  per  cent  This  coal  3nelds  on  destructive  distillation  a  very  large  quantity  of 
gas,  and  is  profitably  used  for  that  purpose.  The  gas  is  not  only  large  in  quantity 
but  remarkably  pure,  and  of  excellent  quality  for  purposes  of  illumination.  There 
is  a  large  quantity  of  this  kind  of  coal  in  the  Scotch  coal-fields,  and  it  has  also  been 
found  in  the  Newcastle  district,  in  the  Wigan  portion  of  the  Lancashire  coal-field, 
and  in  Yorkshire  and  Derbyshire  coal-fields.  America  yields  cannel  coal  in  Kentucky, 
Indiana,  Illinois,  and  Missouri.  Cannel  coal  passes  into  jet,  and  may,  like  jet,  be 
worked  into  various  ornaments,  but  it  is  brittle  and  not  very  hard ;  the  seams  are 
generally  rather  thin,  although  there  are  several  important  exceptions  in  which  the 
quantity  is  very  considerable.  The  coal  of  Belgium  from  one  basin  (that  of  Mons) 
seems  to  be  of  this  kind. 

Another  and  far  more  abundant  kind  of  bituminous  coal  is  that  obtained  abundantly 
in  Northumberland  and  Durham,  and  commonly  used  in  London  and  everywhere  on 
the  east  and  south  coast  of  England.  This  kind  is  also  highly  bituminous,  burns  with 
much  flame,  and  takes  fire  readily,  often  assuming  a  striking  and  very  peculiar  appear 
ance,  illustrated  by  a  column  of  coke  exhibited  by  Mr.  Cory,  and  also  by  other  cokee 
shown  by  the  coal  trade  of  Northumberland  and  Durham.  This  caking  coal,  as  it  is 
called,  yields  on  an  average  of  several  analyses,  about  57  per  cent  carbon,  about  87*6 
volatile  matter,  and  5  per  cent  ash.  Its  specific  gravity  is  1-267,  but  sometimes  higher. 
It  leaves  a  red  ash  in  an  open  fire,  but  req^uires  to  be  deprived  of  its  volatile  matter 
before  being  exposed  to  a  strong  blast,  owing  to  its  tendency  to  cement  together  in  a 
solid  mass  and  prevent  a  free  draught  through  the  grate  or  furnace  in  which  it  is  em 
ployed.  Not  only  the  coals  of  the  Newcastle  coal-field  in  England,  but  those  of  France 
and  Belgium  generally,  of  Bohemia,  and  Silesia  in  Europe,  and  of  Ohio  in  North  Ame- 
rica, are  of  the  caking  bituminous  kind. 

The  coals  of  Stoffordshire,  Yorkshire,  Derbyshire,  Lancashire,  North  Wales,  and 

Vou  IL  3  K 


484 


PITCOAL. 


i  ii 


'i 


V 


many  other  districts^  contain  nearly  or  quite  as  much  bitnminons  and  volatile  matter 
as  that  of  ]!4ewca8tle,  but  do  not  cake  and  swell  in  the  fire,  and  may  therefore  be  em- 
ployed directly  where  strong  heat  is  required  without  previous  coking.  The  coke 
obtained  from  this  coal  is  little  altered  in  appearance.  The  coal  bums  freely  with 
flame  and  gives  much  heat,  but  is  generally  considered  somewhat  inferior  for  household 
purposes  to  that  of  Newcastle.  It  yields  50  to  60  per  cent,  carbon  and  35  to  45  vola- 
tile matter,  and  a  small  quantity,  often  less  than  5  per  cent,  of  ash.  The  ash  is  often 
white.  Most  of  the  coals  from  the  inland  counties  readily  show  white  lines  on  the 
edges  of  the  beds,  owing  to  the  presence  of  argillaceous  earth,  which  effloresces.  In 
this  respect  they  are  less  adapted  for  general  use  than  the  Newcastle  coal,  but  many 
of  them  are  of  excellent  quality. 

Next  in  order  to  the  coals  of  the  midland  counties  generally,  are  those  of  some  parts 
of  North  Wales  and  many  districts  in  South  Wales,  which  contain  a  large  percentage 
of  carbon,  very  little  volatile  matter  and  bitumen,  and  often  but  little  ash,  which  bum, 
however,  freely,  and  without  smoke,  and  are  all  well  adapted  for  steam  pur|)08e8  and 
the  manufacture  of  iron,  or  where  a  strong  blast  and  great  heat  are  required.  Such 
eoals  exist  not  only  in  England,  but  in  France,  and  Saxony,  and  Belgium,  to  some  ex- 
tent They  are  often  tender  or  powdery,  dirty  looking,  and  of  comparatively  loose 
texture,  but  they  often  stand  exposure  to  the  weather  without  alteration  or  injury.  They 
are  called  steam  coals,  and  the  inferior  kinds  are  known  as  culm.  They  contain  carbon 
81  to  86,  volatile  matter  11  to  15,  ash  3  or  thereabouts.  Several  varieties  well  known 
in  commerce  are  exhibited  by  different  proprietors,  and  the  respective  analyses  will  be 
found  in  many  cases  in  the  body  of  the  catalogue  of  the  Exhibition. 

The  last  kind  of  coal  is  that  called  '*  anthracite,"  and  it  consists  almost  exclusively 
of  carbon.  This  coal  is  also  called  non-bituminous,  as  the  steam  coal  is  semiTbituminous. 
The  anthracites  contain  from  80  to  upwards  of  95  per  cent  carbon,  with  a  little  ash 
and  sometimes  a  certain  small  percentage  of  volatile  matter.  They  are  heavier  than 
eommon  coal,  take  fire  with  difficulty,  but  give  an  intense  heat  when  in  full  combua* 
tion  with  a  strong  draught.  Anthracite  occurs  abundantly  in  the  western  part  of 
South  Wales,  in  the  South  of  Ireland,  France,  Saxony,  Russia,  and  in  North  America, 
and  the  use  of  them  is  greatly  on  the  increase.  Amongst  other  things  it  is  used  for 
hop  and  malt  drying  and  lime  burning  with  great  advantage,  but  its  chief  use  is  in  the 
manufacture  of  iron.  The  appearance  is  often  bright,  with  a  shining  irregular  fracture; 
the  coal  is  often  hard,  but  some  varieties  are  tender  and  readily  fractured.  The  ash 
of  anthracite  coal  is  generally  white.  As  a  general  rule,  the  anthracites  are  deficient 
in  hydrogen,  but  contain  a  certain  proportion  of  oxygen  gas. 

The  relative  importance  of  mineral  fuel  in  various  countries,  as  indicated  by  the  actual 
eoal  area  and  the  real  production  of  different  districts,  may  be  understood  by  a  reference 
to  the  subjoined  table.  This  and  other  statistical  tables  are  based  chiefly  upon  the 
authority  of  Mr.  Taylor,  but  have  before  been  given  in  their  present  form  by  the  author 
of  the  present  essay,  Mr.  Anstey. 


Countries. 

Coal  Area  in  Square 

Proportion  of  whole 

Annual  Production  ia 

Miles. 

Area  of  the  Country. 

Tons. 

British  Islands 

12,000 

1-10 

82,000,000 

France           -        -        - 

2,000 

1-100 

4,150,000 

Belgium        -        -        - 

620 

1-22 

6,000,000 

Spain             ... 

4,000 

1-62 

650,000 

Prussia          -        -        - 

1,200 

1-90 

8,600,000 

Bohemia       ... 

1,000 

1-20 

United  States  of  America 

118,000 

2-9 

4,000,000 

British.  North  America  - 

18,000 

It  will  be  thus  seen  how  extremely  important  the  coal-fields  of  the  British  islandi 
really  are  when  compared  with  any  others  elsewhere.  This  is  the  case  not  merely  in 
the  total  annual  production  and  the  proportionate  extent  of  the  deposit,  but  also  from 
the  great  number  of  points  at  which  the  coal  can  be  advantageously  worked.  Thii 
will  be  best  seen  by  reference  to  the  table  appended. 


PITCOAL. 
Table  of  the  principal  Coal  Fields  of  the  British  Islands. 


435 


Estimated 

ToUl 

Estimated 

ToUl 

Thickness 

workable 

Number  of 

Thickness 

Thickest 

of  Coal- 

Area  in 

workable 

of  workable 

Bed  in 

bearingf 

[ 

Acres. 

Seams. 

Coal  in 
Feet. 

Feet. 

Measures 
in  Feet. 

1.  Northumberland  and  Durham 

District : 

Newcastle  coal  field 

600,000 

18 

80 

7 

2.  Cumberland   and   Westmore- 

land and  West  Riding  of  York- 

shire : — 

Whitehaven  and  Akerton 

80,000 

7 

— : 

8 

2,000 

Appleby  (three  basins)  - 

1*7,000 

Sebergham  (Cumberland) 

— 

1 

8 

8 

Eirkby  Lonsdale  -        -        - 

2,600 

4 

17 

9 

8.  Lancashire,     Flintshire,     and 

North  Staffordshire : — 

Lancashire  coal-field     • 

380,000 

75 

160 

10 

6,000 

Flintshire      .        -        -        - 

120,000 

6 

89 

9 

200 

Pottery,  North  SUffordshire 
Cheadle         .        -        -        - 

40,000 

24 

28      . 

10 

10,000 

4.  Yorkshire,    Nottinghamshire, 

Derbyshire,  Ac: — 

Great  Yorkshire  coal-field     - 

650,000 

12 

82 

10 

Darley    Moor,    Derbyshire ) 
Shirley  Moor                            J 

1,500 

5.  Shropshire    and    Worcester- 

shir^  : — 

Coalbrook  Dale,  Shropshire  - 

12,000 

17 

40 

Shrewsbury  -         -        -         - 

16,000 

3 

Brown,  Clee  HiU  -        -        - 

1,300 

8 

Titterstone,  Clee  Hill    - 

6,004 

Lukev  Hill,  Worcestershire  - 
Bewdley       -        -        - 

660 

46,000 

6.  South  Staffordshire : — 

Dudley  and  Wolverhampton 

66,000 

11 

67 

40 

1,000 

7.  Warwickshire  and  Leicester- 

shire:— 

Nuneaton      -        -        -        - 

40,000 

9 

80 

16 

Ashby-de-la-Zouch 

40,000 

5 

33 

21 

8.  Somersetshire  and  Gloncesier- 

shire : — 

Bristol 

130,000 

^ 

90 

Forest  of  Dean      ... 

36,000 

17 

87 

Newcut,  Gloucestershire 

1,600 

4 

15 

7 

9.  South  Welsh  Coal  Field 

600,000 

80 

100 

9 

12,000 

la  Scottish  coal-fields  :— 

Clyde  Valley                        "| 

Lanarkshire                           1 
S^uth  of  Scotland  several  j 

1,000,000 

84 

200 

18 

6,000 

small  areas       .                  J 

Mid  Lothian     "^' ^•' 

_ 

24 

94 

— . ' 

4,400 

East  Lothian    ''■''' 

— 

60 

180 

18 

6,000 

Kilmarnock  -        -        -        ) 
Ayrshire       -        -        -         ' 

— 

8 

40 

80 

Fifeshire        -        -        -        . 

__ 

— . 

._ 

21 

Dumfries  coal  region    - 

46,000 

10 

55 

6 

11.  Irish  coal  fields: — 

Ulster  -        -       -       -       - 

600,000 

9 

40 

6 

Connaught    -        -        -        - 

200,000 

Leinster,  Kilkenny 

160,000 

8 

S8 

Monster  (several)  -        -        - 

1,000,000 

8K2 


m^ 


436 


PITCOAL. 


PITCOAL. 


487 


\y 


> 


The  beds  with  which  the  coal  is  generally  associated  in  the  British  islands  are  various 
sands  and  shales  (imperfect  slaty  beds)  of  different  degrees  of  hardness ;  but  the  actual 
coal  scams  themselves  often  repose  directly  on  clay  of  peculiar  fineness,  well  adapted  for 
fire  bricks,  and  generally  called  under  clay.  The  under  clay  is  used  in  many  coal 
districts  for  various  purposes  of  pottery.  Bands  of  ironstone  (impure  argillaceous 
carbonate  of  iron)  are  very  abundant  in  certain  coal  districts,  but  are  almost  absent  in 
others.  The  Scotch  coal  fields  near  Glasgow,  the  South  Welsh  and  some  others,  are 
rich  in  ironstone,  which  is  the  chief  source  of  the  vast  quantities  of  iron  manufactured 
in  this  kingdom. 

The  principal  coal-fields  of  Europe  apart  from  the  British  Islands  are  those  of  France, 
Belgium,  Spain  (in  the  Asturias),  Germany  (on  the  Ruhr  and  Saare),  Bohemia,  Silesia, 
and  Russia  (on  the  Donetz).  Of  these  the  Belgian  are  the  most  important,  and  occupy 
two  districts,  that  of  Li^ge  and  that  of  Hainault,  the  former  containing  100,000  and  the 
latter  200,000  acres.  In  each  the  number  of  coal  seams  is  very  considerable,  but  tho 
beds  are  thin  and  so  much  disturbed  as  to  require  special  modes  of  working.  The 
quality  of  coal  is  very  various,  including  one  peculiar  kind,  the  Flenu  coal,  unlike  any 
found  in  Great  Britain  except  at  Swansea.  It  bums  rapidly  with  much  flame  and 
smoke,  not  giving  out  an  intense  heat,  and  having  a  somewhat  disagreeable  smell. 
There  are  nearly  fifty  seams  of  this  coal  in  the  Mons  district.  No  iron  has  been  found 
with  the  coal  of  Belgium. 

The  most  important  coal-fields  of  France  are  those  of  the  basin  of  Loire,  and  those  of 
St.  Etienne  are  the  best  known  and  largest,  comprising  about  50,000  acres.  In  this  basia 
are  eighteen  beds  of  bituminous  coal,  and  in  the  immediate  neighbourhood  several  smaller 
basins  containing  anthracite.  Other  valuable  localities  are  in  Alsace,  several  in  Bur- 
gundy much  worked  by  very  deep  pits,  and  of  considerable  extent ;  some  in  Auvergne 
with  coal  of  various  qualities ;  some  in  Languedoc  and  Provence  with  good  coal ;  others 
at  Arveyron  ;  others  at  Limosin  ;  and  some  in  Normandy.  Besides  these  are  several 
others  of  smaller  dimensions  and  less  extent,  whose  resources  have  not  yet  been  developed* 
The  total  area  of  coal  in  France  has  not  been  ascertained,  but  is  probably  not  less  than 
2,000  square  miles.     The  annual  production  is  now  at  least  4,000,000  tons. 

There  are  four  coal  districts  in  Germany  of  the  carboniferous  period,  besides  several 
districts  where  more  modern  lignites  occur.  The  principal  localities  for  true  coal  are 
near  the  banks  of  the  Rhine  in  Westphalia  ;  on  the  Saare,  a  tributary  of  the  Moselle  j 
in  Bohemia  and  in  Silesia,  the  total  annual  production  exceeds  2,760,000  tons. 

Of  these  various  localities,  Silesia  contains  very  valuable  and  extensive  deposits  of  coal, 
which  are  as  yet  but  little  worked.  The  quality  is  chiefly  bituminous,  the  beds  few  in 
number  but  very  thick,  amounting  in  some  cases  to  20  feet.  Some  anthracite  is  found. 
Bohemia  is  even  more  richly  provided  than  Silesia,  the  coal  measures  covering  a  con- 
siderable area  and  occupying  several  basins.  More  than  40  seams  of  coal  are  worked, 
and  several  of  these  are  from  4  to  6  feet  thick. 

The  basin  of  the  Saare,  a  tributary  of  the  Moselle,  near  the  frontier  of  France,  affords 
a  very  important  and  extensive  coal  field,  which  has  been  a  good  deal  worked  and  is 
capable  of  great  improvement  No  less  than  103  beds  are  described,  the  thickness 
varying  from  18  inches  to  15  feet.  It  is  estimated  that  at  the  present  rate  of  extraction 
the  basin  contains  a  supply  for  60,000  years.  On  the  banks  of  the  Ruhr,  a  small 
tributary  to  the  Rhine,  entering  that  river  near  Dusseldorf,  there  is  another  small  coal 
field  estimated  to  yield  annually  1,000,000  tons.  The  whole  annual  supply  from  Prussia 
and  the  German  States  of  the  ZoUverein  or  Customs'  Union,  is  considered  to  exceed 
2,750,000  tons. 

Hungary  and  other  countries  in  the  east  of  Europe  contain  true  coal  measures  of  the 
carbomferous  period ;  but  the  resources  of  those  districts  are  not  at  present  developed. 
On  the  banks  of  the  Donetz  in  Russia,  coal  is  worked  to  some  extent  and  is  of  excellent 
quality,  but  it  belongs  to  the  other  part  of  the  carboniferous  period. 

Spam  contains  a  large  quantity  of  coal,  both  bituminous  and  anthracite.  The  richest 
beds  are  in  Asturias,  andl^the  measures  are  so  broken  and  altered  as  to  be  worked  by 
almost  vertical  shafts  through  the  beds  themselves.  In  one  place  upwards  of  11  distinct 
seams  have  been  worked,  the  thickest  of  which  is  nearly  14  feet  The  exact  area  is  not 
known,  but  it  has  been  estimated  by  a  French  engineer  that  about  12,000,000  of 
tons  might  be  readily  extracted  from  one  property  without  touching  the  portion  existing 
at  great  depths.  In  several  parts  of  the  province  the  coal  is  now  worked,  and  the 
measures  seem  to  resemble  those  of  the  coal  districts  generally.  The  whole  coal  area 
is  said  to  be  the  largest  in  Europe,  presenting  upwards  of  100  workable  seams  varying 
from  3  to  12  feet  in  thickness. 

There  are  in  North  Anaerica  four  principal  coal  areas ;  compared  with  which  the  richest 
deposits  of  other  countries  are  comparatively  insignificant  These  are  the  great  central 
coal-fields  of  the  Alleghanies ;  the  coal-fields  of  Illinois,  and  the  basin  of  the  Ohio ;  that 
of  the  basin  of  the  Missouri ;  and  those  of  Nova  Scotia,  New  Brunswick,  and  Cape 


Breton.  Besides,  there  are  many  smaller  coal  areas  which,  in  other  countries,  might 
well  take  rank  as  of  vast  national  importance,  and  which  even  in  North  America  will 
one  day  contribute  greatly  to  the  riches  of  the  various  States. 

The  Alleghany  or  Appalachian  coal  field  measures  750  miles  in  length,  with  a  mean 
breadth  of  85  miles,  and  traverses  eight  of  the  principal  States  of  the  American  Union. 
Its  whole  area  is  estimated  at  not  less  than  65,000  square  miles,  or  upwards  of  40,000 

Bquare  acres. 

The  coal  is  bituminous  and  used  for  gas.  In  Kentucky  both  bituminous  and  cannel 
coal  are  worked  in  seams  about  3  or  4  feet  deep,  the  cannel  being  sometimes  associated 
with  the  bituminous  coal  as  a  portion  of  the  same  seam ;  and  there  are  in  addition 
valuable  bands  of  iron  ore.  In  Western  Virginia  there  are  several  coal  fields  of  variable 
thickness,  one,  9i  feet ;  two  others  of  6,  and  others  of  3  or  4  feet  On  the  whole  there 
seems  to  be  at  least  40  feet  of  coal  distributed  in  13  seams.  In  the  Ohio  district  the 
whole  coal  field  affords  on  an  average  at  least  6  feet  of  coal.  The  Maryland  district  is 
less  extensive,  but  is  remarkable  as  containing  the  best  and  most  useful  coal,  which  is 
worked  now  to  some  extent  at  Frostbury.  There  appears  to  be  about  30  feet  of  good 
coal  in  four  seams,  besides  many  others  of  less  importance.  Tlie  quality  is  intermediate 
between  bituminous  and  anthracite,  and  is  considered  well  adapted  for  iron  making. 
Lastly,  in  Pennsylvania,  there  are  generally  from  two  to  five  workable  beds,  yielding  on 
an  average  10  feet  of  workable  coal,  and  amongst  them  is  one  bed  traceable  for  no  less 
than  450  miles,  consisting  of  bituminous  coal,  its  thickness  being  from  12  to  14  feet  on 
the  south-eastern  border,  but  gradually  diminishing  to  5  or  6  feet  Besides  the  bitu- 
minous coal  there  are  in  Pennsylvania  the  largest  anthracite  deposits  in  the  States, 
occupying  as  much  as  250,000  acres  and  divided  in  three  principal  districts. 

The  Illinois  coal  field,  in  the  plane  of  the  Mississippi,  is  onlj^  second  in  importance  to 
the  vast  area  already  described.  There  are  four  principal  divisions  traceable,  of  which 
the  first,  or  Indian  district,  contains  several  seams  of  bituminous  coal  distributed  over 
an  area  of  nearly  8,000  square  miles.  It  is  of  excellent  quality  for  many  purposes ;  one 
kind  burning  with  much  light  and  very  freely,  approaching  cannel  coal  in  some  of  its 
properties ;  other  kinds  consist  of  caking  or  splint  coaL  In  addition  to  the  Indian  coal- 
field there  appears  to  be  as  much  as  48,000  square  miles  of  coal  area  in  other  divisions 
of  the  Illinois  district,  although  these  are  less  known  and  not  at  present  much  worked. 
80,000  are  in  the  state  of  Illinois,  which  supplies  coal  of  excellent  quality,  and  with 
great  facility.    Tlie  coal  is  generally  bituminous. 

The  third  great  coal  area  of  the  United  States  is  that  of  the  Missouri,  which  is  little 
known  at  present,  although  certainly  of  great  importance. 

British  America  contains  coal  in  the  provinces  of  New  Brunswick  and  Nova  Scotia. 
The  former  presents  three  coal-fields,  occupying  in  all  no  less  than  5,000  square  miles; 
but  the  latter  is  far  larger  and  exhibits  several  very  distinct  localities  where  the  coal 
abounds.  The  New  Brunswick  coal  measures  include  not  only  shales  and  sandstones, 
as  is  usual  with  such  deposits,  but  bands  of  lignite  impregnated  with  various  copper 
ore,  and  coated  by  green  carbonate  of  copper.  The  coal  is  generally  in  thin  seama 
lying  horizontally.     It  is  chiefly  or  entirely  bituminous. 

In  Nova  Scotia  there  are  three  coal  regions,  of  which  the  Northern  presents  a  total 
thickness  of  no  less  than  14,570  feet  of  measures,  having  70  seams,  whose  aggregate 
magnitude  is  only  44  feet,  the  thickest  beds  being  less  than  4  feet  The  Pictou  or 
central  district,  has  a  thickness  of  7,590  feet  of  strata,  but  the  coal  is  far  more  abundant, 
one  seam  measuring  nearly  30  feet ;  and  part  of  the  coal  being  of  excellent  quality  and 
adapted  for  steam  purposes.  The  southern  area  is  of  less  importance.  Besides  the 
Nova  Scotia  coal-fields  there  are  three  others  at  Cape  Breton,  yielding  different  kinds 
of  coal,  of  which  one,  the  Sydney  coal,  is  admirably  adapted  for  domestic  purposes. 
There  are  here  14  seams  above  3  teet  thick,  one  being  11,  and  one  9  feet 

Coal,  existing  generally  in  beds  of  moderate  thickness  inclined  at  a  small  angle  to  the 
horizon  and  often  at  a  very  considerable  depth  beneath  the  surface,  is  extracted  most 
commonly  by  the  aid  of  pits  or  shafts  sunk  to  the  bed  and  galleries  (levels  of  drifts),  cut 
horizontally  or  in  the  plane  of  the  bed  to  a  certain  distance.  By  a  number  of  such  gal- 
leries cut  at  right  angles  to  each  other ,  the  whole  bed,  within  certain  limits,  is  completely 
laid  open,  the  overlaying  beds  being  supported  by  masses  of  coal  (pillars  or  columns) 
left  untouched  between  the  galleries ;  in  this  way  about  one  third  of  the  coal  can  be  ex- 
tracted, and  afterwards,  on  the  supporting  columns  being  removed,  the  roof  falls  in  and 
the  work  is  regarded  as  finished.  This  method  is  called  technically  the  "  pillar  and 
stall  method,"  and  is  adopted  in  the  Newcastle  coal-field.  In  Yorkshire  and  elsewhere, 
instead  of  such  columns  being  left,  the  coal  is  removed  entirely  and  at  once  without 
columns ;  the  roof  falling  behind  the  work  as  it  advances.  This  is  the  long  wall  method. 
Other  modes  are  occasionally  followed  when  the  condition  of  the  coal  requires  it 

Owing  to  the  gaseous  substances  contained  in  coal  and  given  off,  not  only  on  exposure 
to  heat^  but  also,  to  a  certain  extent^  by  pressure,  many  kinds  of  coal  cannot  safely  be  left 


(i 


488 


PITCOAL. 


during  the  process  of  extraction  without  some  defence  from  the  open  lights  required  by 
the  miner  m  the  mechanical  operations  of  remoYing  the  coal  from  its  bed  and  conveyini 
It  to  the  pit  bottom.  An  explosive  gaseous  compound  is  readily  produced  by  the  mS 
ture  of  the  gases  given  off  by  the  coal,  with  common  air,  made  to  circulate  through 
the  workmgs,  and  if  neglected,  this  compound  accumulates,  and  travels  on  till  it  meeta 
-mth  flame,  and  then  explodes,  causing  frightful  destruction  not  only  to  the  property 
of  the  mine  owner,  but  also  to  the  life  of  the  miner.  Many  contrivances  have  been 
suggested  from  time  to  time,  on  one  hand  to  improve  the  ventilation  of  the  mines, 
And,  on  the  other,  providing  means  of  illumination  which  would  render  accidents  from 
explosion  less  probable,  by  removing  the  immediate  cause.  Examples  of  both  will  be 
found  amongst  the  models  and  instruments  exhibited  in  this  class  of  the  Exhibition. 
It  18  not  likely  that  any  contrivances  can  render  absolutely  safe  an  employment  which 
of  necessity  involves  so  many  and  such  serious  risks  as  are  connected  with  coal  mining- 
but  much  may  no  doubt  be  done  to  diminish  the  danger  both  from  imperfect  venti&^ 
tion  and  open  light 

In  concluding  this  notice  of  mineral  fuel,  it  may  be  worth  while  to  draw  attention  to 
the  vast  and  overwhelming  importance  of  the  subject  by  a  reference  both  to  the  absolute 
and  relative  value  of  the  material,  especially  in  the  British  Islands.  It  may  be  stated 
as  probably  within  the  true  limit,  if  we  take  the  annual  produce  of  the  British  coal 
mines  at  36,000,000  tons,  the  value  of  which  is  not  less  than  18,000,000^.  steriing, 
estimated  at  the  place  of  consumption,  and  therefore  including  a  certain  amount  of 
transport  cost  necessary  to  render  available  the  raw  material  At  the  pit  mouth  the 
value  of  the  coal  is  probably  about  half  this,  or  9,000,000/.  sterling,  and  the  capital 
employed  m  the  coal  trade  is  estimated  at  10,000,000/.  The  average  annual  value  of 
all  the  gold  and  silver  produced  throughout  the  worid  has  been  estimated  to  have 
amounted  in  184*7,  to  nearly  thii-teen  millions  and  three  quarters  sterling.  We  haveu 
thwefore,  the  following  summary,  which  will  not  be  without  interest 


Value  of  the  coal  annually  raised  in  Great  Britain,  estimated 
at  the  pit  mouth  -  -  -  -  . 

Mean  annual  value  at  the  place  of  consumption 

Capital  engaged  in  the  coal  trade 

Mean  annual  value  of  the  precious  metals  obtained  from 
North  and  South  America  and  Russia 

Total  value  of  precious  metals  raised  throughout  the  whole 
world  -  -  -  .  . 

Mean  annual  value  at  the  furnace  of  iron  produced  from 
British  coal      -  -  -  - 


9,000,000 
18,000,000 
10,000,000 

5,000,000 

13,000,000 

8,000,000 


Boghead  Coal. — ^At  Boghead,  near  Bathgate,  in  Scotland,  is  a  very  valuable  gas  coaL 
The  mineral  substance  so  called  is  a  true  coal,  and  belongs  to  the  great  coal  formation 
of  this  island.  It  differs  in  no  essential  respect  from  the  Cannel  coal  found  in  the  south- 
west of  Scotland,  in  North  Wales,  and  in  many  parts  of  England.  It  contains  the  same 
remains  of  plants  which  characterise  the  coal  formation  all  over  the  world,  that  is  to 
say,  impressions  of  sigillarise,  stigmariae,  Ac  In  a  chemical  point  of  view,  the  resem- 
blance becomes  much  more  striking,  and  is  altogether  so  decisive  that  I  do  not  hesitate 
to  declare,  in  the  most  positive  manner,  my  opinion  that  the  Boghead  coal  is  as  much 
8  coal  as  any  other  coal  in  the  kingdom. 

The  conchoidal  fracture,  the  specific  gravity,  and  the  general  habitude  when  burnt 
are  precisely  like  those  of  the  whole  of  the  coal  found  in  and  around  the  Boghead  dis- 
trict, and  many  striking  points  of  resemblance  maybe  noticed  in  these  and  other 
respects  between  the  Boghead  and  other  coals  from  the  south  of  Scotland,  such  as  the 
Kirkness,  the  Arniston,  the  Wemyss,  the  Capeldrae,  Ac,  as  well  as  with  many  from 
England,  Wales,  and  even  India,  as  will  be  shown  hereafter.  Thus  the  nature  of  the 
gases  they  evolve  by  heat  is  the  same,--they  are  all  proof  against  heated  naphtha,  oil  of 
turpentme,  aether,  Ac— they  are  equally  so  against  dilute  alkaline  and  acid  solutions—in 
-chemical  composition  they  are  alike— the  ash  is  the  same,  and  indicates  a  common 
origin,  whereas,  in  these  respects,  all  these  coals  differ  totally  from  every  form  of 
bitumen,  lignite,  retinite,  and  bituminous  shale  which  has  yet  come  under  my  notice. 
It  would  be  a  work  of  supererogation  to  enter  more  fully  into  a  detail  of  these  parti- 
culars, nor  is  this  at  all  necessary  towards  the  completion  of  my  proof  I  have  asserted 
that  the  Boghead  coal  is  a  true  coal,  and  belongs  to  the  Cannef  variety  of  that  mineral 
In  support  of  the  assertion  I  append  the  following  table  of  coals  analysed  for  this  pur- 
pose, and  proving  beyond  all  contradiction  that  it  is  not  even  at  the  extreme  limit  of 
the  class  to  which  it  belongs^  but  occupies  a  central  and  very  unequivocal  poaition  in 
the  Cannel  coal  eerie& 


prrcoAL. 


439 


Mum  of  SolMtanc*. 


New  Bnuuwick   As- 
phalt. 

Indian  coal,  No.  1. 


No.l 
Le>mahago 
Capeldrae 
Lockgelly 
Kirkness 
Old  Wemysa     - 
Boghead 
Brymbo  Canael, 


Specific 
Gravity. 


Sheffield  Cannel 
Portland  Shale  - 


No. 
No. 


Seyssell  Asphalt 


1098 


1-363 

1-290 
1-220 
1-227 
1-320 
1-215 
1-325 
1-223 
1-574 
1-520 
1-526 
1-766* 


1-780' 


For  Ce.it- 
•geof 

Combuiitibte 
Matters. 


99-4 


87-5 

88- 

90-9 

89-5 

86-9 

86-5 

84-9 

77-2 

66-8 

68-8 

66- 

48-9 


57-8 


Per  Cent. 
at  A»h. 


Nmturaof  A^ 


Silica 


19-5 

12- 
91 
10-5 
131 
135 
15  1 
228 
332 
31-2 
34- 
511 


42-2 


Trisilicate     of      alu- 
mina. 

Ditto    -  -  - 

Ditto    -  -  - 

Ditto    .  -  - 

Ditto    - 

Ditto    -  -  - 

Ditto    - 

Ditto    - 

Ditto    - 

Ditto    - 

Ditto    - 

Ditto    - 

Carb,,  phosphate, 
silicate  of  lime 
sand. 

Carbonate      of 
only. 


Remarks. 


Largely  soluble  in 
naphtha,  oil  of  turps, 
sther,  and  sulphuret 
of  carbon. 

Insoluble  in  the  abore 
and  in  dilute  acids. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 

Ditto        ditto. 
-Ditto        ditto. 


and; Slightly  soluble,  Acted 
with      on  with  slight  effer- 

Tescence. 
lime  Largely  soluble.    Ra- 
pidly acted  on  with 
eflfervescence. 


pnvoAT       tExhmi<m.\-Almo  Musba^h,    Vienna,  Proprietor— Thu  coal  mina 
however,  the  production  »f -^l^-^'.yj^^";;:?^^^^^         ;  ,,a  at  a  rapid  ratio.   H.. 

rsLft^'::iinrrfi^^^j5^^ 

the  imports  of  foreign  coal  by  about  300,000  cwt     A  large  propon 

of  a  brown  colour  posse^eB  ^""^^  ™'i"^ S^'^^nie  to fhe ^.untriiand distrieU 

^hS:\uSnru\Ta^|;>^^^^^^^^^^^ 

STernrrulte'^urt  ;VetXtht^^^^^^ 

and  its  miiufacture.     Our  ancestors  were  producers  ^^  ?<>?J-f7  'J>^^^  ^^l  SaI^^^^I 
of  this  important  agent  belongs  to  the  F^^ent  century ;  and  ther^^^^^^^       *The  P^duction 

elastic  fluids  or  gases,  with  a  triflm^  production  of  tar  and  ^^P\^^^^^^ 
however  apt  to  induce  some  grave  inconveniences,  as  ^"^  aPPf^^^^^^J-^f'^^iSj"  i,_^ 
the  gls  maker,  in  ite  first  process,  sails  between  «^  ^ind  «^  ^.th!  ^ItZ^ud^^^^^^^^ 
to  dVead  an  excessive  production  of  tar  on  the  one  hand,  and  the  evils  ^«^/"^^J^^^ 
Ihe  other.     Presuming  however   that,  the  P-per  temperat^^^^^^^  has  leen  --red,^^; 
successful  production  of  good  coal  gas  is  not  yet  ^^^^^^^^^^^^^^^^^     ^^^'^^  conductor 
introduction  into  the  retort,  are  free,  or  neariy  so,  from  water.   Coal  is  a  oaa  couu 

♦  \9tj  variable. 


i  I- 


440 


PITCOAL. 


of  heat;  and  therefore  when  a  quantity  of  this  substance  in  a  wet  condition  is  throw, 
.^to  a  red-hot  retort,  as  precisely  by  gas  manufacturers,  the  ouTer  po^tiorfTws  m^ 

of  th'rall'rb'^l'piT?^^^  "^"^  '•'^.^'  '''\'  long  before  the  ^ater  in  the  ce^^ 
of  the  coal  has  been  expelled;  consequently,  as  the  heat  penetrates  through  the  coaL 
th^  water  18  vaporized,  and  driven  in  the  form  of  steam  over  the  red^b^t  coke  on  tha 

I^ll^lnTf  wh  •  V^  • '• "?  "^  ^l^  ^^^^  "^"'  ^^^'•^g-'  carbonic  oidf  and  Lr^^^^^^^ 
acid,  all  of  wh  ch  are  injurious  to  the  gas  maker ;  the  two  first  by  diluting  his  cas  and 
Wering  its  illuminating  power;  the  last,  by  neutralizing  the  Kcontfined  ?n  the 
puriher,  and  thus  needlessly  causing  an  increased  consumption  o^  that  article  But 
the  presence  of  water  in  coal  is  also  determined  in  another  way^  for  teconver^k,n  into 
.team  implies  the  absorption  of  an  immense  amount  of  heat,  slice  the  latent  heat  o^ 
steam  is  upwards  of  960°;  consequently,  as  this  absorption  tikes  plLi  imL.W.lv 
previous  to  the  decomposition  oflhe  bituminous  constitutes  of  the  coal  a  dTsposS 
r^ults  to  generate  at  that  time  a  temperature  capable  only  of  producinTtir  or  S  C 

?he  12/  briw  ^'  'r°^"'^??  "'  ^"'^'■^'^ '  */^  ^^"«  ^'^''^^^'  onl/tends  to  rS 
tw^.       ^'     u  *^'*'  ^^  lessen  the  quantity,  of  gas  procurable  from  any  given  coal- 

J^r tTthllt;^^^^^^^^^         "^^^"'^  ^^^  '-  P^^P--  «^«^<^  ^-y«  ^'  '-^aTned 

We  have  previously  remarked,  that  too  high  a  temperature  ought  to  be  avoided  in  th« 

Srh^  ;r!i1  '?^-^"^  ""^'^r  ^^^  ^^^  very  important  reasons.  Che  Lt  place  he^^^^ 
car buretted  hydrogen  or  olefiant  gas  is  decomposed  at  a  white  heat,  or  even  under  thZ 

^rbon  th''"°'''''.r  r^'^^-  f^rburetted  hydrogen,  and  the  production  of  charcoaHJ 
carbon,  thus  greatly  diminishmg  the  value  of  the  gas  as  an  illuminating  ngent  The 
second  reason  is  still  more  conclusive.  All  coals  contain  iron  pyrites,  which  at  a  low 
to  a  B^  iil  T7TV"''  P^«J«,f  Ph^'-.^t  of  iron  and  free  sul^Lr  ;lhe  lattoi  uniting 
to  a  portion  of  the  hydrogen  of  the  coal  passes  off,  and  is  found  in  the  gas  in  the 
rfiape  of  sulphuretted  hydrogen,  leaving  the  protJsulphuret  of  iron  fn  t^he  Retort 

ohnrlfTf '  ^'  ^«°^^°^t>rV^'  "/•T^'^^^S  «^  '""^^  ^«  mentioned  that  this  protos^l- 
phuret  of  iron  was  resolved  by  a  high  and  long  sustained  heat  into  metaUic  iron  which 
remained  m  the  coke,  and  into  the  bisulphuret  of  carbon,  which  escaued      Now  tl,. 
application  of  a  high  heat  in  gas  makingLs  exactly  the  same  etcfas  fn  coke^^^^^^^^^^ 
and  produces  in  both  cases  bisiUphuret  of  carbon,  which,  mixing  with  the  coalX  can 
never  afterwards  be  removed.     It  consequently  remainL  in  th!  gas,  and  when^xis^s 
burnt  m  the  ordinary  way,  gives  rise  to  the  production  of  sulphuric  acid  or  oH  of 
vitriol;  and  this,  a  though  generated  by  most  of  the  common  gai  of  our  street  i^  an 
mfinitesimal  quantity,  is  nevertheless  found  sufficient,  in  a  few  years,  to  attack  and 
destroy  the  binding  and  paper  of  the  books  in  our  public  librarie^^an?corrode  articles 
liZ-^'  'r'^'  f'"'"'  "'  ?^f'    Th^V">P<>^'t-"t  fact  has  not  received  a  proper  simre  of 
consideration  from  our  best  gas  engineers  until  within  the  last  few  moiths;  and  hence 

.riil  i^  ^^'''T  ^  .^^'^^.^^  ?"  ^<^^  ^™i«h  books  completely  discoloured  and 
rotted  through  a  great  portion  of  each  page,  though  in  a  few  years  all  further  traces  of 
this  mischievous  effect  of  gas  will  have  vanished. 

Having  thus  far  commented  on  the  production  of  coal-gas,  we  next  pass  to  th« 
^mination  of  the  processes  emploj^-ed  in  rendering  it  pure  and  fit  for  the  uies  to  which 
It  IS  applied  in  common  hfe.     The  first  process  is  that  of  condensation,  by  wh  ch  rarl V 
the  whole  of  the  vapours,  properiy  so  termed,  are  condensed  and  separatod  from  the  per^ 
manently  elastic  gases.    l3y  this  means,  tar.  water,  naplitha,  carbonate,  muriate!  and 
hydrosulphurate  of  ammonia,  are  removed  from  the  ga^the  only  impurities  of  wWch 
now  are  carbonate  of  ammonia,  carbonic  acid,  and  sulphuretted  h/drog1^n.    Water  alone 
will  remove  all  three  of  these  impurities ;  but  its  action  is  weal^  and  chiefly  exercised 
upon  the  fii^t     Hence,  although  usefully  employed  for  attracting  carbonat^Tf  ammonia 
(as  exemphfied  m  Lowe's  scrubber,   it  is  not  used  by  gas  engineers  of  the  present  dav 
with  a  view  to  total  purification,  this  being  soughti?  in  thi  supW  affinity  olfml* 
after  the  ammonia  has  been  arrested  by  other  means.     Coal-gas,  after  condeLtio^ 
usually  contains  about  2  per  cent,  of  carbonic  acid,  and  1  per  cent  of  sulSetted 
hydrogen  ;  but  these  vary,  of  course,  with  the  nature  of  the  coal,  and  also  as  we  have 
rtated  above  with  the  dryness  of  the  coal,  which  has  much  to  do  with  the  production  of 
carbonic  acid.    These  proportions  may,  however,  be  regarded  as  a  fair  average  of  New- 
castle  coal-gas,  and  would  justify  the  consumption  of  about  40  lbs.  of  lime  for  ev!^ 
10,000  cubic  feet  of  ^as ;  a  quantity  which,  although  far  below  the  propor  i^  ex^nde'S 
m  common  practice  IS  really  very  near  the  consumption  of  lime  carried  out  at  the  Wes^ 
mmster  station  of  the  Chartered  Gas  Company,  by  Mr.  R  J.  Evans,  during  a  long 
course  of  carefully  conducted  experiments,  and  ought,  therefore,  to  bTkept  if  view  J 
an  ultimatum  by  gas  engmeers.    Where  much  more  lime  than  is  found  in(fi8pensable  to 
good  purification,  there  is  reason  to  suspect  either  that  the  coal  is  damp,  or  that  it  con- 
tains more  than  an  average  quantity  of  sulphur.    The  amount  of  sulphS-  in  good  New- 
eastle  coal  is  as  nearly  as  possible  1  per  cent,  by  weight,  and  in  some  of  the  cLiel  c^ 


PITCOAL,  COKING  OF. 


441 


^1: 


it  is  even  less ;  thus  Boghead  Cannel,  for  example,  has  barely  one-half  per  cent.,  or  64 
of  sulphur  on  an  average.  How  necessary,  then,  is  it  that  every  gas  engineer  should 
Se Twe  to'determine  the  quantity  of  sulph'ur  existing  in  coal!  but  even  th^^^^^^^^o^* 
other  knowledge,  is  worthfess  ani  deceptive  Sulphur  seems  to  !>;  Pf^^^^^^VTbtui 
two  states;  the  one  and  most  frequent  is  that  m  which  it  is  umted  to  iron  ^bisul- 
phuret  of  iron  or  pyrites  ;  the  other  is  in  a  doubtful  state  of  combmation,  but  probably 
Ft  eists  conjoined  to  the  bitmninous  elements  of  the  coal  in  the  stato  of  sulphur  Jo 
theTas  maker  this  difference  is  very  important,  as  in  the  former  case,  one-half  only 
of  the  total  sulphur  would  pass  away  with  the  gas  and  contaminate  it,  whereas  m  the 
second,  the  whole  would  be  carried  to  the  purify mg  vessels;  consequently^  in  deter^ 
Sg  the  amount  of  sulphur  in  coal,  a  gas  engineer  must  ascertain  first  how  much 
Xhur  the  pure  coal  contains,  and  next  how  much  sulphur  remains  in  an  eqmvalent 
of  the  coke  of  such  coal ;  after  which  the  latter  must  be  deducted  from  the  f^rmey  to 
get  at  the  sulphur  contamination  of  the  coal,  when  its  value  for  gas  purposes  is  sought 

*^Th\t\Cinf  detailed  explanation  will  furnish  the  gas  engineer  with  a  means  by 
which  coal  ma|  be  analyze(t  with  a  view  to  the  ob  ect  in  question.  Having  carefiJly 
Teduced  a  VrLmpleof  the  coal  to  a  very  fine  powder,  mix  100  grains  of  this  powder 
^TsO  grains  of  pure  and  dry  carbonate  of  soda ;  after  which  place  the  mixture  m  a 
dear  iron 7id  e,  aSd  roast  the  whole  over  a  brisk  fire,  at  a  good  red  heat  for  several 
minutes,  so  as  to  burn  off  the  whole  of  the  coal,  or  nearly  so;  then  remove  the  ladle 
from  the  fire  and  when  it  is  cold,  add  50  grains  of  pure  and  powdered  nitre  mixing 
to  well  wTt'h  the  residue  of  the  coal  and  carbonate  of  soda;  after  which,  place  the 
ladle  agai^  on  the  fire  and  keep  it  red  hot  for  a  few  minutes,  wjien  it  must  be  agam 
removeTsuffered  to  cool,  and  its  soluble  contents  washed  out  with  water  and  thrown 
on  a  mter.  To  the  filtered  liquor  an  excess  of  pure  nitric  acid  must  be  added,  and 
then  a  solution  of  nitrate  of  Lryta  dropped  in  until  aU  precipitation  ceases  ;-b«n 
the  sulphate  of  baryta,  thus  formed  may  be  allowed  to  settle,  or  be  thrown  on  a 
counterpoise  filter,  washed,  dried,  and  weighed.     Its  eqmvalent,  or  117  grains,  indi 

"HavinlTliu:  dStd  the  quantity  of  sulphur  in  the  coal,  100  grains  more  of  «!• 
powdered  coal  are  to  be  taken  Ind  placed  in  an  earthen  <!"^<^^^  ^'  ^^^^^f  Y^^^^^ 
closely  fitting  cover :  when  the  cover  is  put  on,  the  crucible  is  subjected  to  a  red  heat 
ItTlfnflammablegasisno  longer  evolved ;  the  crucible  must  then  be  removed  and 
covered  up  in  dry  sand  to  cool.  As  soon  as  the  crucible  is  cold,  remove  the  coke  it 
Sntains.Td  aft^r  reducing  it  to  a  fine  powder,  mix  with  it  50  g-ms«f  pure  and 
dry  carbonate  of  soda ;  place  the  whole  in  an  iron  lad  e  and  proceed  exactly  as  mdi 

caLd  above  with  respect  to  coal    The  amount  «f/"lP»^"/.^«;^,"^;°/^f,/^^l,^^* 

then  be  deducted  from  that  previously  ascertained  to  exist  in  the  coal,  the  difference 

being  the  true  sulphur  contamination  of  the  coal  under  examination. 

PITPOAL  COKING  OF.     See  also  Charcoal.  ,     .    ^  •    ,. 

5^1 1127  represents  a  shachtofen,  or  pit-kiln,  for  coking  coals  m  Germany,     a  is  the 

Htg.  ii^<  rep'^^^  J         j.^.^^  (chemise)y  made  of  fire  bricks ;  the  enclosing 

walls  are  built  of  the  same  material ;  h,  6,  is  a  cast- 
iron  ring  covered  with  a  cast-iron  plate  c.     The 
floor  of  the  kiln  is  massive.      The  coals  are  in- 
troduced, and  the  coke  taken  out,  through  a  hole 
in  the  side  d  ;  during  the  process  it  is  bricked  up, 
and  closed  with  an  iron  door.      In  the  surrounding 
walls  are  4  horizontal  rows  of  flues  «,  e,  e,  «,  which 
are  usually  iron  pipes ;  the  lowest  row  is  upon  a 
level  with  the  floor  of  the  kiln ;  and  the  others  are 
each  respectively  one  foot  and  a  half  higher  than 
the  preceding.     Near  the  top  of  the  shaft  there  is 
an  iron  pipe  /,  of  from  8  to  10  inches  in  diameter, 
which  allows  the  incoercible  vapors  generated  in 
the  coking   to  escape  into   the   condenser,  which 
consists  either  of  wood  or  brick  chambers.     For 
kindling  the  coal,  a  layer  of  wood  is  first  placed 

,^-.,-.-,  -  on  the  bottom  of  the  kiln. 

The  coking  of  small  coal  is  performed  upon  vaulted  hearths,  somewhat  like  bakers- 
ovens,  but  with  still  flatter  roofs.  Of  such  kilns,  several  are  placed  alongside  one  another, 
each  being  an  ellipse  deviating  little  from  a  circle,  so  that  the  mouth  may  project  but 
a  small  space.  The  dimensions  are  such,  that  from  10  to  12  cubic  feet  of  coaI-<Julm 
may  be  spread  in  a  layer  6  inches  deep  upon  the  sole  of  the  furnace.  The  top  oi  tne 
flat  arch  of  fire  brick  should  be  covered  with  a  stratum  of  loam  and  sand.  ^ 

Fias  1128  &  1129.  represent  such  a  kiln  as  is  mounted  at  Zabrze,  in  Upper  bilesia, 
for  coking  small  coaL     Fig.  1128.  is  the  ground  plan ;  Jiff,  1129.  the  vertical  section  m 

Vol.  IL  »  ^ 


1127 


!f. 


M 


442 


PITCOAL,  COKING  OF. 


PITCOAL,  COKING  OF. 


443 


«he  line  of  the  long  axis  ot  Jig.  1128,  a,  is  the  sand-bed  of  the  hearth,  under  the  brick 
•Die ;  b,  18  the  roof  of  large  fire-bricks ;  c,  the  covering  of  loam;  d,  the  top  surface  of 
—  ~~"  sand  ;  e,  the  orifice  in  the  front  wall,  for  admission  of  the 

culm,  and  removal  of  the  coke,  over  the  sloping  stone/.  The 
flame  and  vapours  pass  off  above  this  orifice,  through  the 
chimney  marked  g,  or  through  the  aperture  h,  into  a  lateral 
chimney,  t,  is  a  bar  of  iron  laid  across  the  front  of  the 
door,  as  a  fulcrum  to  work  the  iron  rake  upon.  A  layer 
of  coals  is  first  kindled  upon  the  hearth,  and  when  this  is 
in  brisk  ignition,  it  is  covered  with  the  culm  in  successive 
sprinklings.  When  the  coal  is  sufficiently  coked,  it  is 
raked  out,  and  quenched  with  water. 

Fig.  ]  130.  represents  a  simple  coking  meiler  or  mound, 
constructed  in  a  circular  form  round  a  central  chimney  of 
loose  bricks,  towards  which  small  liorizontal  flues  are  laid 
ainong  the  lumps  of  coals.  The  sides  and  top  are  covered 
with  culm  or  slack,  and  the  heap  is  kindled  from  certain 
openings  towards  the  circumference.  Fig.  1131.  represents 
an  oblong   meiler ^    sometimes  made   100  or  150  feet  in 


length  and  from  10  to  12  in  breadth.  The  section  in  the  middle  of  the  figure  shows 
how  the  lumps  are  piled  up;  the  wooden  stakes  are  lifted  out  when  the  heap  is 
finished,  in  order  to  introduce  kindlings  at  various  points;  and  the  rest  of  the 
meiler  is  then  covered  with  slack  and  clay,  to  protect  it  from  the  rains.  A  jet  of 
smoke  and  flame  is  seen  issuing  from  its  left  end. 

An  excellent  range  of  furnaces  for  making  a  superior  article  of  coke,  for  the  service 
of  the  locomotive  engines  of  the  London  and  Birmingham  Railway  Company,  has  been 
recently  erected  at  the  Camden  Town  station ;  consisting  of  18  ovens  in  two  lines,  the 
whole  discharging  their  products  of  combustion  into  a  horizontal  flue,  which  tenniaales 


\K 


m  a  chimney-stalk,  115  feet  high.  Fig.  1132  is  a  ground  plan  of  the  elliptical  ovens,  each 
being  12  feet  by  1 1  internally,  and  having  3  feet  thickness  of  walls,  a,  a,  is  the  mouth,  3i 
feet  wide  outside  and  about  21  feet  within,  h,  b,  are  the  entrances  into  the  flue  •  thev 
may  be  shut  more  or  less  completely  by  horizontal  slabs  of  fire-brick,  resting  on  iron 
frames,  pushed  m  from  behind,  to  modify  the  draught  of  air.  The  grooves  of  these  dam- 
per-slabs admit  a  small  stream  of  air  to  complete  the  combustion  of  the  volatilized  par- 
ticles of  soot.  By  this  means  the  smoke  is  well  consumed.   The  flue  <?,  c  is  2^  feet  high. 


by  21  inches  wide.  The  chimney  4,  at  the  level  of  the  ^ue,  is 
11  feet  in  diameter  inside,  and  17  outside ;  being  buUt  from  an 
elegant  design  of  Robert  Stephenson,  Esq.  (See  Chimney.; 
d,  I  are  the  keys  of  the  iron  hoops,  which  bind  the  brickwork  of 
the  oven.  Fie.  1133  is  a  vertical  section  in  the  line  A,  b,  oi  jig. 
1132  showing,  at  6,  6,  and  e,  e,  the  entrances  of  the  difl-erenl  ovens 
into  the  horizontal  flue  ;  the  direction  of  the  draught  being  indi- 
cated by  the  arrows.  /,/,  is  a  bed  of  concrete,  upon  which  the 
whole  furnace-ran?e  is  built,  the  level  of  the  ground  being  in  the 
middle  of  that  bed.  g  is  a  stanchion  on  which  the  crane  w 
mounted ;  (see^g.  1134.)  his  a  section  of  the  chimney  wajl,  witH 
part  of  the  interior  to  the  left  of  the  strong  hue.  f»fi:-1134is  a 
front  elevation  of  two  of  these  elegant  coke-ovens ;  in  which  the 

113S 


1134 


bracing  hoops  ,-,  i,  i  are  ^-o- ,  fc,  k. -^he  -']- tS^rfit^fnteT^^  ^ 
trC^f'rLr^-^  ^"/ed^l'^d  loiS:^  !:;'»'«L\flai„s  and  counterweigh...  »oved 

upon  the  body  of 
the  fuel.  In  this 
way  the  smoke  is 
consumed  at  the 
very  commence- 
ment     of     the 
process,  when  it 
would  otherwise 
be    most    abun- 
dant,   A  neigh- 
bor      of       iha 
above       coking 


ovens, 
lately 


having 
indicted 


them  as  a   nuisance,  procured,  secundum   artem,  a   parcel  of  affidavits  from   sundiy 
chemical  Ld  mS  Ln.     T^vo  of  the  former,  who  had  not  -^f-V^hlt^"^^^^^^^^^ 
had  espied  the  outside  of  the  furnaces'  range  at  some  ^^iff^""^^' ^f^^^T?**    Hovv  i^^^^^^^^^ 
process,  as  performed  at  the  ovens,  is  a  species  of  distillation  of  coal !       ««^^^^^^y.^^ 
Unpractical  \heorists  affirm   what   is  utterly  unfounded,  ^"^  Jfjf  ^^..^^"on  Sut  a 
iud-e!     That  the  said  coking  process  is  in  no  respect  a  spec  es  of  distillation,  but  a 
Complete  cumbusUon  of  the  volatile  principles  of  the  coal,  wil    ^^%"^^f  jj^^^j^^^^ '^^^ 
following  description  of  its  actual  progress.     The  mass  of  coals  is  first  k^»dl^^^^^^^ 
suLe,  as  above  stated,  where  it  is  supplied  with  abundance  of  atmospheric  ox^^^^^^ 
because  tlie  doors  of  the  ovens  in  front,  and  the  throat-vents  behind,  we  then  left  open 
T^e  consequence  is.  that  no  more  smoke  is  discharged  from  the  top  of  the  clumnej^  at 
Ss  the  mS  sooty  period  of  the  process,  than  is  produced  by  an  ordinary  kitchen  fire^ 
S  thesrcircumstances.  the  coal  gas,  or  other  gas,  supposed  to  be  generated  m  U^e 
^htirheatTmass  beneath  cannot  escape  destruction  in  passing  up  through  the 

8  L  2 


--fipiWM 


444 


PLATED  MANUFACTURE. 


drogen  gases  which  iSay  escape  from  bX^^  'jhet^^^^^^^^^  I'  sulphuretted  hy- 

downward  order,  cannot  emit  into  the  atmosphere^anv  mor^^  when  calcmed  in  this 
gases  than  the  smallest  heap;  and  therefore  the  a^mpnT/'  *?^  above-mentioned 
magnitndc  of  the  operations  is  altogether  fallacious!^  ''"^  ''^  *""^""*  ^^  *»>• 

The  coke  being  perfectly  freed  from  all  fuliginous  and  volatile  matter*!  hv  »  r»ln;n-f:«- 
of  upwards  of  40  hours,  is  cooled  down  to  n.^erale  ignition  by~  ?n\hetrper^ 
and  sliding  up  the  doors,  which  had  been  partially  closed  during  the  la  ler  nart  XS 
process  It  is  now  observed  to  form  prismatic  concretions,  somUha^e  fcohii^ 
mass  of  basalt  These  are  loosened  by  iron  bars,  liAed  out  upon  hovels  funi^hS^ 
with  long  iron  shanks,  which  are  poised  upon  swing  chains  with  hooked  ends  and  t^ 
umps  are  thrown  upon  the  pavement,  to  be  exlin|uished  by  sprSgTat'er  unon 
oCfn  '/•  "'''^f  ^  watering-can;  or,  they  might  be 'transfer  e? into  a  iaree 
chest  of  sheet-iron  set  on  wheels,  and  then  covered  up!  Good  coals  thus  treated  vipW 
SO^per  cent,  of  an  excellent  compact  glistening  coke;  'weighing  about  14  cwt.  per' c'h'aU 

»nJ!ln.\''''  ^^■T!t^ !"  coking  in  the  ordinary  ovens  is  usually  reckoned  at  25  per  cent  • 
and  coal,  which  thus  loses  one  fourth  in  weight,  sains  one  fourth  in  bulk  ' 

joy^tTrLably^sSoThe^Th/^"'"  ^"'^^^^'  ^^  rightly-constructed  coke  ovens,  se.m  to  en 

If  f/J^  '\^ ti^^  '^-7^  f  ^^^  ^  '"'''■'""^  principles  detected  in  wood-tar  by  Reichenbach 
1   IS  a  dark.blue  solid  substance,  somewhat  like  indigo,  assumes  a  metallic  fie^lustr^^^^^^ 
f.  ct.on,  and  varies  m  tint  from  copper  to  golden,     if  is  void  of  taste  and  smel?  not  vola 
lile  ;  carbonizes  at  a  high  heat  without  emitting  an  ammoniacal  smeH    "s  sS  or  ralh.; 
very  dilfusible  in  water;  gives  a  green  solution  with  a  cast  of  crSi   irsuloLnvljH 
with  a  cast  of  red  blue,  in  muriatic  acid,  and  with  a  cast  of  aurora  red/inace^acT^ 
^o^tmordantf'"     ''  ''"  ^  ''''  '^"^  "P^"  ^^'^^'^  '''  ^««-  good^  with  Un  a'd'alu" 

PLASTER;  S^e  Mortar. 

PLASTER  OF  PARIS ;  see  Gvpsum. 

for\omnf  as  ft  will  hn  J  !lT  *^'  1''  ^"u*  ^'  T^^^  ^^^^^^  «*-^^«^^«  ''«  ^^e  vessel  used 
and  drv  tL  '  L  lu  "^y*  ^""^  ^l^""^  ^^"^  ^^^'^  ^«^  «  «bort  time ;  then  withdraw  them, 
?l?oo^  *''^^''^,^^^^^'  continue  this  until  all  the  articles  have  been  treated  h! 

^IntTvf'"?''"^'  then  introduce  into  the  hartshorn  water  clearwoolLn  ra^^^^^^ 

theTilter""  TU^T'"!  "^^^^  i^'T't^'  "^*^^  ^^^^^  ^^^  *^«-'  -^  "-  them  for  poKg 

dool  Whe?  hf«?i^'  '^"J'f  '"^'^"°r  ^?^  .^^^"°^°^  ^''^'  «°^  b^^««  handle?  of  roorf 
Tsoft  IP  JvTI    t^P^l^^^/^V'^es  are  perfectly  dry,  they  must  be  carefully  rubbed  with 

ment  of  Inv  J^A  '^''^\''^'  ^^'^^^°^  ^  "^^^"^°^  ^""^  "^"^^  preferable  to  the  empToy- 
^^siWer^IJH^^V  ri^^'T^  mercury    as  mercury  has  the  eflfect  of  rende^rUig 

The^vJ^nJf.t^^^^^V^^r^f''*''^^"^  </^  p/ayt.e,  Fr"^;  Silber  plattirnng,  Germ.) 
in^  of  Zr.r  /k"^  '"  not  apphed  to  ingots  of  pure  copper,  but  to  an  alloy  conS 
mgof  copper  and  brass,  which  possesses  the  requisite  stit^^ness  for  the  various  art"cleT 

to  thelrt" Vhrr^  or  gate  to  gn.e  pressure  to  the  liquid  metal,  andfecure  sol  dity 
r^pr^L  K^  •      .        '^?''^i  '*  ^^^^^^'  t^"  t*»e  grease  with  which  its  cavity  is  besmeared 

S  isThen'ir'''''  ^"'  Ir  r'  *^"™-  ^^^  P^«P^^  ^^^^  -^  ^^e  m^l ^  3  for 
hT.?nh%  A^  *i,  ^««^,«8  a  bluish  colour,  and  is  quite  liquid.  Whenever  the  met^l 
has  solidified  m  the  mould,  the  wedges  that  tighten  its  rin^  are  driven  out  lesTthi 

¥SeZnM  ^'  '"^/  '^?^^  ^"^«^  th«  ^«"^<i  to  <^r^«t-     «^e  Bras"  '      '  '^"^ 

i«  fi  L^    1     "^'T  "^l?^^^  carefully  with  the  file  on  one  or  two  faces  according  as  it 

ute  one-for1^:th  of'^thl't^'^V  ^^     ^T  .**^^^^"^««  «^  ^^^  "^^^  P^^^e  is  sich  as  t'fon'st^^ 

thkt  tL  siW  ^^^^^  ^•'^'''  ''^  i^"  ^'^go*'  o"-  ^h«°  thi«  «  »^  i««Ji  and  a  quarter 
tnick,  the  Sliver  plate  apphed  is  one  thirty-second  of  an  inch  •  being  by  weight  a  nnuTTJ 

liltly  e^  tr^l:^^^^^^ '  *^  ''  Peon^jei^hts  of  the  latterTe^Twt  wh?^^^^^ 
^tCated  ^l^^tf^nf  Kn^^^ '^^^^^  ^  '^  truly  with  iron  wire,  and  a  little  of  a 

saturated  solution  of  borax  is  then  insinyated  at  the  edges.     This  salt  melts  at  a  low 

S^ioVoMStetlf  Vt"- 'P^''I^  "^'^^  "^^>^  ^^^^-«  the  copper  and  XtJ^ct  Z 
town  of  the  metals.     The  mgot  thus  prepared  is  brought  to  the  plating  furnace 
The  furnace  has  an  iron  door  with  a  small  hole  to  look  through ;  it  if  fed  ^S'coke 


PLATED  MANUFACTURE. 


445 


laid  upon  a  grate  at  a  level  with  the  bottom  of  the  <io<>-     ^^^.^^Ve  P^^^^^^^^  "eT- 

diately  upon  the  cokes,  the  door  is  shut,  and  the  P^^^Jd''  D^  n  Ah^^^^^      of  the  silver 

gtant  when  the  proper  soldering  temperature  is  attained.  J^^^^fJ^^^^^^^^tact  with  the 

and  copper,  the  surface  of  the  former  is  seen  to  be  ^^^awn  into  intimate  com 

fattr.  ^aSd  this  species  of  Hvetting  is  the  signal  -  removing  t^e  compound  bar  i^^^^^^^ 

from  the  furnace.     Were  it  to  remain  a  very  little  longer,  the Jil>  er  wo 

alloyed  with  the  copper,  and  the  plating  be  thus  completely  spoiled    Tb^^f  hes»«^^^ 

fac^CcLplished  here  by  the  formation  of  a  fihn  of  true  silver-solder  at  the  surfaces  of 

^^hfineot  is  next  cleaned,  and  rolled  to  the  proper  thinness  between  cylinders  as  de- 
scrM  umler  Mint;  being  in  its  progress  of  lamination  frequently  annealed  on  a  srn^l 
gcrioeu  uuuci  "*  »  Aftprthe  last  annealing,  the  sheets  are  immersed  in  hot  dilute 
TuIpt^raad'Tni^cot^e"^^^^  fini  Calais  sand ;  they  are  then  ready  to  be  fashioned 

'"V"  ''Tii'Jnt  onnnpT'wire  the  «»ilver  is  first  formed  into  a  tubular  shape,  with  one  edge  pro:. 

:  Jt^n^.  s  "^ro"^^^^^^  ^»--^  a  redhot  copper  cylinder  being  somewhat 

ectmg  s^^?*^   y  °Jf '  ,"L_,     '   closely  pressed  together  with  a  steel  burnisher,  whereby 

w  Jprfi'rmW  unilei      The  tube,^  l^^^^^^^  cleaned  inside,  and  put  on  the  prop- 

they  get  firmly  un  led.     1  he  tub  i         ,^  .^  ^^^^  ^  ^.^^^^  ^^^^  .^^ 

Vu^Zl  is  torved  at   hrextrL^^^^     of  the  klter,  so  that  the  silver  edges,  being  worked 
1  \he  c^meTJrcK>ve,  m^^^^^^^  the  air  from  the  surface  of  the  rod.     The  compound 

TvUnder  is  now  heS  redhot,  and  rubbed  briskly  over  with  the  steel  burnisher  in  a  Ion- 
^ndinaldire^^ion  whereby  the  two  metals  get  firmly  united,  and  form  a  solid  rod  ready 
fo  Sf  drawaTn  o  wke  of  any  requisite  fineness  and  form ;  as  flat,  half-round,  fluted,  or 
■^  rnrmriincTs  accordin-  to  the  figure  of  the  hole  in  the  draw-plale.  Such  wire  is  mu^n 
ITs  5  fT  S  bre'd-^^^^^^^^  -"ffers,  and  articles  combining  elegance  with 

ilthtnt's  and  economy.     The  wire  must  be  annealed  from  lime  to  lime  during  ihe  draw 
;«'«  on/1  finnllv  cleaned,  like  the  plates,  with  dilute  acid.  ^  ,      ,     , 

Xmeriy  the  tSt  sh^  vessels  of  plated  metal  were  all  fashioned  b>'  the  ham 
me^  but  every  one  of  simple  form  is  now  made  in  dies  struck  with  a  drop-hammer  oi 
Stamp.    Some  manufacturers  employ  8  or  10  drop  machines. 

Aq.  1135.  &  1136.  are  two  views  of  the  stamp ;  a  is  a  large  stone,  the  moremassythe 
better ;  b,  the  anvil  on  which  the  die  e  is  secured  by  four  screws,  as  shown  in  the  ground 
plan,^^.  1137.    Injig,  1136.,  a  a  are  two  upright  square  prisms,  set  diagonally  with  the 

lis? 


Ill 


i 


n 


angles  opposed  to  each  other ;  between  whieh  the  ha™?"  "''^XlmeHsSffd  K 
means  of  nicely  fitted  angular  grooves  orreeesses  m  its  s.de^  .^helmmmer  is  raise     j 

pulling  the  rope/,  which  passes  over  the  pulley  c,  and  is  I'^f*"/™"* '"f !?,  ?„»  and 
according  to  tEel  npulse  Squired.  Vessels  which  are  less  in  ^J'^^f  ?* J^^rTai  °d 
bottom  tLn  in  theLddle,S.ust  either  be  raised  by  *«  ^t"""?"  7i^Eed»P»"  *« 
by  a  hand  hammer.    ThedieUusuallymadeofca«(  steel    Whenit  ifl  placea  upu 


li 


446 


PLATED  MANUFACTURE. 


anyfl,  and  the  plated  metal  is  cut  into  pieces  of  prooer  mzp  fh«  fftT%  /xf  *t,«  Ai^  :  At. 
surrounded  wi£  a  lute  made  of  oil  anlclay,  forC fnlh^'tt^ abSvf  itel^^a^e  •  tl 
the  cavity  ,8  filled  with  melted  lead.  The  under  face  of  the  stamp^mmmer  has  a  pSte 
of  iron  called  t}\e  Itcker-up  fitted  mto  it,  about  the  area  of  the  die^  Whenever  the  lead 
has  become  solid  the  hammer  is  raised  to  a  certain  height,  and  droppenown  uDonTt  • 
and  as  the  under  face  of  the  licker-up  is  made  rough  like  a  raso  if^rmW^Si^  *  ' 
the  lead  so  as  to  Hft  it  afterwards  wfth  the  hammfr.  iSe^aL^d  metnsVowXed 
over  the  die,  and  the  hammer  mounted  with  its  lead  is  let  Lu  repeatedly  uZ  VtiU 
the  impression  on  the  njetal  is  complete.  If  the  vessel  to  be  struck  be  Tanv  con- 
siderable  depth  two  or  three  dies  may  be  used,  of  progressive  sizes  in  succe^ioiT^  But 
It  occasionally  happens  that  when  the  vessel  has  a  loi^  conical  neck,  rrcoTe  mnsf  be 
had  to  an  auxiliary  operation,  called  puru:hinr^.  See  ^e  embossing  puncher/?^!  138 
These  are  made  of  cast  steel,  with  their  hollows  turned  out  in  the  lathe.  T^Viec^l 
^6  are  of  lead.  TJe  punching  is  performed  by  a  series  of  these  tools,  of  differed 
Bizes,  beginning  with  the  largest,  and  ending  with  the  least  By  this  means  a  hoTw 
cone,  3  or  4  inches  deep,  and  an  inch  diameter,  may  be  raised  out  of  a  flat  platl 
These  punches  are  struck  with  a  hand  hammer  also,  for  smaU  articles  of  too  ^eat 
delicacy  fof  the  drop.  Indeed  it  frequently  happens  that  one  part  of  an  artide  is 
executed  by  the  stamp  and  another  by  the  hand.  f       w  an  anicie  is 

Cylindncal  and  conical  vessels  are  mostly  formed  by  bending  and  soldenng.     The 
bcndms:  is  performed  on  blocks  of  wood,  with  wooden  mallets ;  but  the  machine  so 
much  used  by  the  tin-smiths,  to  form  their  tubes  and  cylindric  vessels  (see  the  end  section 
"""  '  /g«.1139andll40),raightbe  employed  with  advantage! 

This  consists  of  3  iron  rollers  fixed  in  an  iron  frame,  a,  b,  c, 
are  the  three  cylinders,  and  a,  b,  c,  d,  the  riband  or  sheet 
of  metal  passed  through  them  to  receive  the  cvlindrical  or 
conical  curvature.    The  upper  roller  a  can  be  raised  or 
lowered  at  pleasure,  in  order  to  modify  the  diameter  of 
the  tube  ;  and  when  one  end  of  the  roller  is  higher  than 
the  other,  the  conical  curvature  is  given.     The  edges  of  the  plated  cylinders  or  cones 
are  soldered  with  an  alloy  composed  of  silver  and  brass.    An  alloy  of  silver  and  copper 
IS  somewhat  more  fusible;  but  that  of  brass  and  silver  answers  best  for  plated  meial 
the  brass  being  in  very  small  proportion,  lest  the  color  of  the  plate  be  aft'ected      Calcined 
borax  mixed  with  sandiver  (the  salt  skimmed  from  the  pots  of  crown  glass)  is  used  alone 
with  the  aUoy,  in  the  act  of  soldering.     The  seam  of  the  r-iated  metal  being  smeared  with 
that  saline  mixture  made  into  a  pap  with  water,  and  the  bils  of  laminated  solder,  cut  small 
with  scissors,  laid  on,  the  seam  is  exposed  to  the  flame  of  an  oil  blowpipe,  or  to  that  of 
charcoal  urged  by  bellows  in  a  little  for^e-hearth,  till  the  solder  melts  and  flows  evenly 
along  the  junction.     The  use  of  the  sandiver  seems  to  be,  to  prevent  the  iron  wire  that 
binds  the  plated  metal  tube  from  being  soldered  to  it. 

Mouldings  are  sometimes  formed  upon  the  edges  of  vessels,  which  are  not  merely 
ornamental,  but  give  strength  and  stifl*ness.  These  are  fashioned  by  an  instrument 
called  a  5irage,  represented  in /g5. 1141  and  1142.  The  part  a  lifts  up  by  a  joint,  and  the 
metal  lo  he  swaged  is  placed  between  the  dies,  as  shown  in  the  figures ;  the  tail  b 
being  held  in  the  jaws  of  a  vice,  while  the  shear-shaped  hammer  rests  upon  it.  By 
striking  on  the  head  a,  whUe  the  metal  plate  is  shifted  successively  forwards,  the  beadine 
IS  formed  In  ^g.  1141  the  tooth  a  is  a  guide  to  regulate  the  distance  between  the 
bead  and  the  edge.    A  similar  efi'ect  is  produced  of  late  years  in  a  neater  and  more  expe- 

1141        rrn  ^^**  ^^^^ 


PLATINUM  MOHR. 


447 


ditious  manner  by  the  rollers,  ^g».  1142,  1143.  Fig.  1145  is  a  section  to  show  the 
form  of  the  bead.  The  two  wheels  a,  a.  Jig.  1143  are  placed  upon  axes,  two  of  which 
are  furnished  with  toothed  pinions  in  their  middle  j  the  lower  one,  being  turned  by  the 


silver  f^^J'  J^^rf  g^  ^^rface  spekily  worn  ofl",  and  thus  assumed  a  brassy  look.    The 

that  the  sunk  part  of  ^^^J^  die  should  be  siee^  generally  emploved  to  form  these  silver  or- 
•Tame^tr  ¥hf  ;n:rdVstiro"S;:J  SSTg^s  filled  ^ith  soft  solder,  and  then  bent 
into  the  requisite  form.  ^^^y  ^ade  in  a  die  by  the  stamp,  as  weU  as  the 

The  base  f  ^^^^^J^^f  »';'„^^  J/^^^^^^  and  the  tubular  stem  or  pillar.    The  dif- 

neck,  the  dish  part  of  th^  n*^«  «  /oft  and  others  with  hard  solder.    The  branches  of 

whUe  the  plate  is  still  Bat,  and  fixed  b,  burnishing  w.th  great  pressure  over  «  hot 
"^t  JsJ'fiih  ^^"'grSiven  by  bumishing-tools  of  bloodstone,  fix«i  in  shee.- 
""^^r^i::  rir^tS  ^St'v^tt  ^m^  with  advantage  by  the  deHcU 

1  Jfi  was  338  889/  but  the  vilue  of  the  plated  goods  is  not  given  in  the  tables  of  lev- 
^e  M  pS' the  greyest  manufacturer  of  plated  goods  in  P^MSL^^n  ft;„« 
ZsbusfnessU  monopolized  by  the  capital),  who  makes  to  the  value  of  ,  00,000  fran« 
mis  Dusmess  u  "'"•'  l~        ooo^kid,  he  savs,  is  the  whole  internal  consumpUon  of  the 

EtL7om"£thattheik^KsumVtlo^^ 

'^'^^ri^trtoJ^r^  ",^eT^v:r?isti:x„„n  fene.3 

eUhTampsTbu'r  ^X  P™\tSr„A  wocHoulds  in^t^^^^^^^^^^     lathe  ^c. 

Lu  ^^.r^  f  h3r'strcu^"So":j,rdiSrent"s^i:s^^^^^^^^^^ 

^PLATINUM  MOHR.    This  interesting  preparation,  which  so  rapidly  oxidizes  alco- 
hof^JaSa™    by  what  has  bercalled  in  ehem  stry  the  ca^^^^^^^^^^ 
action,  is  most  easily  prepared  by  the  fol  owing  Pro^css  of  M.  f^«,^^\^J '^^^^^^^^ 
powder  of  potash-chiarure  or  ammonia-chlorure  of  platinum  i.  to  f  ^J^^^^^^^f^XJ? 

LThu  He  aid  io^f^:^:^:!,^  t\lte  wated  ktt^with^Sfu^^^ 
S  ardXYwi^h  wat   *^r fin^enl^if  ttis  powder  depends  upon  that  of  the 

S^Une  po.^e^/em^^^^^^  make  it;   so  that  if  these  ^t,  ^^'^^^^l^T      "  ^Xm^i 

SfplaWm  mohr  wifl  be  also  very  fine,  and  proportionally  powerfiil  as  a  chemical 

""^The  following  easy  method  of  preparing  igniferous  ^^ack  platinum,  P^^^^^^^^^^  thirty 
years  aL'o  by  M  Descotil,  has  been  recently  recommended  by  M.  Dobereiner  .-■ 
^Md^Dlatina  ore  with  double  its  weight  of  zinc,  reduce  the  allojr  to  powder,  and 
treat  it  Ct  with  dilute  sulphuric  acid,  and  next  with  dilute  nitric  a«d,  to  oxidize  and 
Sssolve  outlll  the  z!nc,  wlSch,  contrary  to  one's  expectations,  is  somewhat  difficult  to 
do  even  at  a  boS^^^^^^  The  insoluble  black-gray  powder  con^ins  some  osmmret 

of  iridiui^  united  w^ith  tiie  crude  platinum.  Tliis  compound  acts  like  ."°^P^^  Pl^^V^^* 
blaclTafS'r^t  has  been  purified  by  digestion  in  potash  Y,^rArmL^°L7dt^1he 
Its  oxidizing  power  is  so  great,  as  to  transform  not  only  the  /ormic  acid  into  the 
carbonic,  and  alcohol  into  vinegar,  but  even  some  osmic  acid,  from  the  metallic 
osmium.     The  ^bove  powder  explodes  by  heat  like  gunpowder. 

When  the  platinaJoAr  prepared  by  means  of  zinc  is  moistened  Y;^^  al.«*^*>^  ^^^ 
comes  incan/escent,  and  emits  osmic  acid;  but  if  it  be  mixed  with  alcoho  into  a  past^ 
and  spread  upon  a  watch-glass,  nothing  but  acetic  acid  will  be  disengaged ;  affording  an 
elegant  means  of  diffusing  the  odour  of  vinegar  m  an  apartment  bee  ^^'^J-ff,  ., 
Platinizing  by  the  moUt  way.  Manufacturing  and  operative  chemists  wiU  find  it 
exfeedingly  valuable  in  order'^to  produce  a  covering  of  platma  for  Jhen-  copper  A^ 
vessels,  fhe  experiment  succeeds  ^est  when  we  make  use  of  a  dilute  s^^V^t^^"  ^fJ^J 
Sle  chloride  o^f  soda  and  platina.  Three  immersions  suffice ;  between  ea«h  mimersi^^ 
it  is  necessary  to  dry  the  surface  with  fine  linen,  rubbing  rather  briskly,  after  which  it 


-"■'^--•iWi 


448 


PLATINUM. 


PLATINUM. 


449 


.toof    T.  •  V^  A      T^^  ?f  ^  grayish-white  color,  rcsembJin?  in  a  good  measure  Dolished 
steel.     It  IS  harder  thah  silver,  and  of  about  double  its  density,  UToTlT^iirJ^v^ 

Native  Ptatmum.-U  the  nataral  state  it  is  never  pure,  bein?  alloved  with  sev^ml 

^o  1      ^^1°^  ""^  .^^^  ^"^'"^  °^  "''^^^^  platinum  is  generally  a  grayish-white  like  tarnhhpd 

2r,  orT  '  T"'''"  "^i'^^  T^^  ^™^"^  ^"-^  «^«^  fi"^d  with^rVhy  and  feV  u4ous  mal^ 
ters,  or  sometimes  with  small  grains  of  black  oxyde  of  iron,  adherinrto  the  surface  of 
the  platmum  grains  Their  specific  gravity  is  also  much  lower  than  that  of  for4d  Dur« 
platinum  ;  varying  from  15  in  the  small  particles  to  18-94  in  M  W,,mh^w.i  i  ^  ^^ 
men     This  relative  lightness  is  owing  to'the  pre^enVe  of  il^'c^f;^^  aidTh^o'me: 

^ndlr"  Jum^*'''  ""'  lately  discovered  metalUc  constituents,  piXm^oslm^h^^^^ 
Its  main  localities  in  the  New  Continent,  are  in  the  three  following  districts  — 
1.  At  Choco,  in  the  neighborhood  of  Barbacoas,  and  generally  Sn  the  coa-ts  of  th« 
fSS^hf^^J,''?  **"  the  western  .lopes  of  the  Cordillera  of  the  A^e.,  between^^^^^^ 
and  the  6th  degrees  of  north  latitude.     The  gold-washin'-s  that  fnmAh  TJ f  J^  I- 
are  those  of  Condoto,  in  the  province  of  Novita  •  Those  of  w/p"/  t  P»atinum, 

Santa  Lucia  of  the  Vavine  of  Iro"  and  Cto,  betw:eVNovi ta  and  TaSdJ"  Th?.?! 
^Ueof  gold  and  platinum  grains  is  founrin^lluvial  Vou^taf  a  dipth  ^^^^ 

amal..«H-?n  f  ''T^^'?  ^'°'"  ^^^  -^^^^^"""^  ^^  P^^^'^"?  ^''^  »»»«  hand,  and  also  by 
amalgamation  ;  formerly,  when  ,t  was  imagined  that  platinum  might  be  used  to  debaS 
go  d,  the  grams  of  lhe,former  metal  were  thrown  into  the  rivers,  through  wikh  mistaken 
opinion  an  immense  quantity  of  it  was  lost.  misiaKeu 

2.  Platinum  grains  are  found  in  Brazil,  but  always  in  the  alluvial  land*!  thnf  /.nnfo:« 
From'  tC  o7Sc!,"  ^'r  ^'  ""^'^^T,  The  ore'of  thistum^t  soteU'at  diff 
T^iK  1      r  ^K     •     ^^.  'f  '"  ^'■^'"''  ^^'""^  '^^°»  t«  ^^  fragments  of  a  spongy  substance 
The  whole  of  the  particles  are  nearly  globular,  exhibiting  a  surface  formed  of  small 

bSlTant     ^'''^"^'^^'^^  «^-?Jy  ^«^-i"g  together,  whose  interstices  .^eclean^nd^^^^^^^ 

This  platinum  includes  many  small  particles  of  gold,  but  none  of  the  ma^nPtl^  irnn 
sand  or  of  the  small  zircons  which  accompany  the  Peruvian  ore?    I  is  mixed^  w^  smaU 
grams  of  native  palladium,  which  may  be  recognised  by  their  fibrous  orrrdktedTruclure 
and  particularly  by  their  chemical  characters.  ^auiaieu  siruciure, 

3.  Platinum  grains  are  found  in  Hayti,  or  Saint  Domingo,  in  the  sand  of  the  river 
Jacky,  near  the  mountains  of  Sibao.     Like  those  of  Choco  thev  are    n  sm^lt  >.rnr     f 
grains  as  if  polished  by  friction.     The  sand  containing  therisquarrzoseandTer^^^^^^^^^ 
This  native  platinum  contains,  like  that  of  Choco,  chromium   rnnn^r^ll-         •""•?• 
rhcdiu.,  palladia.,  and  probably  Utaniu..    VaSq'„eIirc3  finT"i  g^Td'Ttiillg  I^ 

Platinum  has  been  discovered  lately  in  the  Ruscsian  f#»rritAi.,-oo  ;„  .i,  -r 

of  Kuschwa  230werstsfrom  Ekateriebo'urg^Td'ccnC^m?^ 

which  seems  to  be  analogous  with  that  of  South  America  geoio^^icai  position 

These  auriferous  sands  are,  indeed,  almost  all  superficial;  they  cover  an  areillaceon, 
soil .  and  include,  along  with  gold  and  platinum,debrisof  doleritc  (aS  of  g"fi^^^^^^^^^^^ 
protoxyde  of  iron,  grains  of  corundum,  &c.  The  platinum  -rains  are  not  \sn  fln^^!  i  k  ^' 
from  Choco,  but  they  are  thicker ;  they  have  less'brilCcrand  Tore  of "  feaden  hu? 
This  platinum,  by  M.  Laug.er's  analysis,  is  similar  in  purity  to  that  of  Choco  but  the 
leaden-gray  grains,  which  were  taken  for  a  mixture  of  osmium  and  iridium,  a^e  merely  an 
alloy  of  platinum,  containing  25  per  cent,  of  these  metals  merely  an 

The  mines  of  Brazil,  Columbia,  and  Saint  Domingo  furnish  altogether  only  about  400 
kilos,  ofplatmum  ore  per  annum;  but  those  of  Russia  produce  a£,ve  1800  kilo^    The 


latter  were  discovered  in  1822,  and  were  first  worked  in  1824.  They  are  all  situated  in 
he  Ural  mountains.  The  ore  is  disseminated  in  an  argillaceous  sand,  of  a  greenish-graY 
color  resulting  from  the  disintegration  of  the  surrounding  rocks,  and  constitutes  from  1 
to  3  parts  in  4000  of  the  sand.  Occasionally  it  has  been  found  in  lumps  weighing  8  kilo- 
erammes  (16  1bs. !),  but  it  generally  occurs  in  blackish  angular  grains,  which  contain 
70  per  cent,  of  platinum,  and  3  to  5  of  iridium.  The  ore  of  Goro-Blagodatz  is  in  small 
flattened  grains,  which  contain  88  per  cent,  of  this  precious  metal.  The  osmiure  of  iri- 
dium is  found  upon  a  great  many  points  of  the  Urals,  throughout  a  space  of  140  leagues, 
being  a  product  accessor^'  to  the  gold  washings.  32  kilogrammes  of  osmiure  are  collected 
there  annually,  which  contain  upon  an  average  2  per  cent,  of  platinum. 

M.  Vauqueiin  found  nearly  ten  per  cent,  of  platinum  in  an  ore  of  argentiferous  cop- 
per which  was  transmitted  to  him  as  coming  from  Guadalcanal  in  Spain.  This  would  be 
thc*only  example  of  platinum  existing  in  a  rock,  and  in  a  vein.  As  the  same  thing  has 
not  acrain  been  met  with,  even  in  other  specimens  from  Guadalcanal,  we  must  delay 
drawing  geological  inferences,  till  a  new  example  has  confirmed  the  authenticity  of 

Platinum  has  been  known  in  Europe  only  since  1748,  though  it  was  noticed  by  Ulloa 
in  1741.  It  was  compared  at  first  to  gold;  and  was,  in  fact,  brought  into  the  market 
under  the  name  of  white  gold.  The  term  platinum,  however,  is  derived  from  the  Spanish 
word  plata,  silver,  on  account  of  its  resemblance  in  color  to  that  metal. 

The  whole  of  the  platinum  ore  from  the  Urals  is  sent  to  St.  Petersburg,  where  it  is 
treated  by  the  following  simple  process :—  ^,      -        .  •  •      r 

One  part  of  the  ore  is  put  in  open  platina  vessels,  capable  of  containing  from  6  to 
8  lbs.,  along  with  3  parts  of  muriatic  acid  at  25"  B.  and  1  part^of  nitric  acid  at  40". 
Thirty  of  these  vessels  are  placed  upon  a  sand-bath  covered  with  a  glazed  dome  with 
moveable  panes,  which  is  surmounted  by  a  ventilating  chimney  to  carry  the  vapors 
out  of  the  laboratory.  Heat  is  applied  for  8  or  10  hours,  till  no  more  red  vapors 
appear;  a  proof  that  the  whole  nitric  acid  is  decomposed,  though  some  of  the  muriatic 
remains.  After  settling,  the  supernatant  liquid  is  decanted  off  into  large  cylindrical  glass 
vessels,  the  residuum  is  washed,  and  the  washing  is  also  decanted  off.  A  fresh  quantity 
of  nitro-muriatic  acid  is  now  poured  upon  the  residuum.  This  treatment  is  repeat- 
ed till  the  whole  solid  matter  has  eventually  disappeared.  The  ore  requires  for 
solution  from  10  to  15  times  its  weight  of  nitro-muriatic  acid,  according  to  the  size  of  iU 

grains.  *  ^i.    •  -j- 

The  solutions  thus  made  are  all  acid;  a  circumstance  essential  to  prevent  the  indium 

from  precipitating  with  the  platinum,  by  the  water  of  ammonia,  which  is  next  added. 

The  deposite  being  allowed  to  form,  the  mother  waters  are  poured  off,  the  precipitate  is 

washed  with  cold  water,  dried,  and  calcined  in  crucibles  of  platinum. 

The  mother-waters  and  the  washings  are  afterwards  treated  separately.  The  first 
oeing  concentrated  to  one  twelfth  of  their  bulk  in  glass  retorts,  on  cooling  they  let  fall 
the  iridium  in  the  state  of  an  ammoniacal  chloride,  constituting  a  dark-puqile  powder, 
occasionally  crvstallized  in  regular  octahedrons.  The  washings  are  evaporated  to  dryness 
in  porcelain  vessels ;  the  residuum  is  calcined  and  treated  like  fresh  ore ;  but  the  platinum 
it  aflords  needs  a  second  purification. 

For  agfflomerating  the  platinum,  the  spongy  mass  is  pounded  in  bronze  mortars;  the 
powder  is  passed  through  a  fine  sieve,  and  put  into  a  cylinder  of  the  intended  size  of  the 
ingot.  The  cylinder  is  fitted  with  a  rammer,  which  is  forced  in  by  a  coining  press,  till 
the  powder  be  much  condensed.  It  is  then  turned  out  of  the  mould,  and  baked  36  hours 
in  a  porcelain  kiln,  after  which  it  may  be  readily  forged,  if  it  be  pure,  and  may  receive 
any  desired  form  from  the  hammer.  It  contracts  in  volume  from  l-6th  to  l-5th  during 
the  calcination.  The  cost  of  the  manufacture  of  platinum  is  fixed  by  the  administration 
at  32  francs  the  Russian  pound ;  but  so  great  a  sum  is  never  expended  upon  it. 

For  Dr.  Wollaston's  process,  see  Phil.  Trans,  1829,  Part  I, 

Platinum  furnishes  most  valuable  vessels  to  both  analytical  and  manufacturing 
chemists.  It  may  be  beat  out  into  leaves  of  such  thinness  as  to  be  blown  about  with  the 
breath. 

This  metal  is  applied  to  porcelain  by  two  different  processes;  sometimes  in  a. 
rather  coarse  powder,  applied  by  the  brush,  like  gold,  to  form  ornamental  figures; 
sometimes  in  a  state  of  extreme  division,  obtained  by  decomposing  its  muriatic  solution, 
by  means  of  an  essential  oil  such  as  rosemary  or  lavender.  In  this  case,  it  must  be 
evenly  spread  over  the  whole  ground.  Both  modes  of  application  give  rise  to  a  steely 
lustre. 

The  properties  possessed  in  common  by  gold  and  platinum,  have  several  times  given 
occasion  to  fraudulent  admixtures,  which  have  deceived  the  assayers,  M.  Vauqueiin 
having  executed  a  series  of  experiments  to  elucidate  this  subject,  drew  the  following  con- 
clusions : — 

Vol,  XL  8  M 


ii 


'•'t-tv 


450 


PLUMBAGO. 


If  the  platinum  do  not  exced  30  or  40  parts  in  the  thousand  of  the  alloy,  the  gold 
does  not  retain  any  of  it  when  the  parting  is  made  with  nitric  acid  in  the  usual  way ; 
and  Avhen  the  proportion  of  platinum  is  greater,  the  fraud  becomes  manifest;  Jst  by  the 
higher  temperature  required  to  pass  it  through  the  cupel,  and  to  form  a  round  button ; 
2.  by  the  absence  of  the  lightning,  fulguration,  or  coruscation;  3.  by  the  dull  while 
color  of  the  button  and  its  crystallized  surface ;  4.  by  the  straw-yellow  color  which 
platinum  communicates  to  the  aquafortis  in  the  parting;  5.  by  the  straw-yellow  color, 
bordering  on  white,  of  the  comet,  after  it  is  annealed.  If  the  platinum  amounts  to  one 
fourth  of  the  gold,  we  must  add  to  the  alloy  at  least  3  times  its  weight  of  fine  silver, 
laminate  it  very  thin,  anneal  somewhat  strongly,  boil  it  half  an  hour  in  the  first  aquafortis, 
and  at  least  a  quarter  of  an  hour  in  the  second,  in  order  that  the  acid  may  dissolve  the 
whole  of  the  platinum. 

Were  it  required  to  determine  exactly  the  proportions  of  platinum  contained  in  an 
alloy  of  copper,  silver,  gold,  and  platinum,  the  amount  of  the  copper  may  be  found  In 
the  first  place  by  cupellation,  then  the  respective  quantities  of  the  three  other  metals 
may  be  learned  by  a  process  founded,  1.  upon  the  property  possessed  by  sulphuric  acid 
of  dissolving  silver  without  affecting  gold  or  platinum ;  and,  2.  upon  the  property  of  pla- 
tinum  being  soluble  in  the  nitric  acid,  when  it  is  alloyed  with  a  certain  quantity  of  gold 
and  silver. 

According  to  Boussingault,  the  annual  product  of  platinum  in  America  does  not  exceed 
8|  cwts.  At  Nis»?hne-Tagilsk,  in  1824,  a  lump  of  native  platinum  weighing  fully  10  lbs. 
was  found  ;  and  in  1830,  another  lump,  of  nearly  double  size,  which  weighed  35|  Prus* 
fiian  marcs;  fuUy  18  lbs.  avoirdupois. 

PRODUCTION  OF  PLATINUM  IN  THE  URAL. 

From  1822  to  1827  inclusively,  52  puds*  and  22*  pounds. 

1828  94 

1829  78  31 J 

1830  105  1 

1831  to  1833      348  16 

AwALTSEs  of  the  Plvtinum  Ores  of  the  Urals,  and  of  that  from  Barbacoas  on  the 
Pacific,  between  the  2d  and  Hth  degrees  of  northern  latitude. 


From  Nischne-Tagilsk. 
Berzcliiis. 

Uoroblagodat. 

BarbacoM. 

Osann. 

Berzelius. 

Magnetic. 

Not  Maapnetic. 

Platinum 

73-58 

78-94 

83-07 

86-50 

84-30 

Iridium  - 

2-35 

4-97 

1-91 

,     _ 

1-46 

Rhodium 

1-15 

0-86 

0-59 

1-15 

3-46 

Palladium 

0-30 

0-28 

0-26 

MO 

1-06 

Iron 

12-98 

11-04 

10-79 

8-32 

5-31 

Copper  - 

5-20 

0-70 

1-30 

0-45 

0-74 

Undissolved        ^ 

Osmium  and     > 
Iridium             ^ 

2-30 

1-96 

1-80 

1-40 

— 

Osmium 

^_ 



1-03 

Quartz  - 
Lime     - 

■"" 

^a^m 

— 

— 

0-60 
0-12 

97-86 

98-75 

99-72 

98-92 

98-08 

PLUMBAGO.  See  Graphite,  for  its  mineralogical  and  chemical  characters.  The 
mountain  at  Borrowdale,  in  which  the  black-lead  is  mined,  is  2000  feet  high,  and  the  en- 
trance to  the  mine  is  1000  feet  below  its  summit.  This  valuable  mineral  became  so  com- 
mon  a  subject  of  robbery  about  a  century  ago,  as  to  have  enriched,  it  was  said,  a  ereat 
many  persons  liymg  m  the  neighborhood.  Even  the  guard  stationed  over  it  by  the  pro- 
prietors was  of  little  avail  against  men  infuriated  with  the  loveof  plunder ;  since  in  those 
days  a  body  of  miners  broke  into  the  mine  by  main  force,  and  held  possession  of  it  for  a 
considerable  time. 

The  treasure  is  now  protected  by  a  strong  building,  consisting  of  four  rooms  upon 
the  ground  floor;  and  immediately  under  one  of  them  is  the  openin?,  secured  by  a  trap- 
door, through  which  alone  workmen  can  enter  the  interior  of  the  mountain.  In  thw 
anartment,  called  the  dressing-room,  the  miners  change  their  ordinary  clothes  for  their 

•  One  pud  =40  Russian  pounde,  =  69,956  Pruwian  marcs  (See  Silvek)  ;  1  pound  -  96  lolotnito 


PORCELAIN. 


451 


worKing  dress,  as  they  come  in,  and  afler  their  six  hours'  post  or  journey,  they  again 
change  their  dress,  under  the  superintendence  of  the  steward,  before  they  are  suffered  to 
go  out.  In  the  innermost  of  the  four  rooms,  two  men  are  seated  at  a  large  table,  sorting 
and  dressing  the  plumbago,  who  are  locked  in  while  at  work,  and  watched  by  the  steward 
from  an  adjoining  room,  who  is  armed  with  two  loaded  blunderbusses.  Such  formidable 
apparatus  of  security  is  deemed  requisite  to  check  the  pilfering  spirit  of  the  Cumberland 
mountaineers. 

The  cleansed  black-lead  is  packed  up  into  strong  casks,  which  hold  1  cwt.  each.  These 
are  all  despatched  to  the  warehouse  of  the  proprietors  in  London,  where  the  black-lead 
is  sold  monthly  by  auction,  at  a  price  of  from  35s.  to  45s.  a  pound. 

In  some  years,  the  net  produce  of  the  six  weeks*  annual  working  of  the  mine  has,  it  is 
said,  amounted  to  30,000Z.  or  40,000/. 

PLUSH  (Panne,  Peluche,  Fr. ;  Wollsammety  Plmch,  Germ.)  is  a  textile  fabric,  having 
a  sort  of  velvet  nap  or  shag  upon  one  side.  It  is  composed  regularly  of  a  woof  of  a 
sinde  woollen  thread,  and  a  two-fold  warp,  the  one,  wool  of  two  threads  twisted,  the  other, 
goat's  or  camel's  hair.  There  are  also  several  sorts  of  plush  made  entirely  of  worsted. 
It  is  manufactured,  like  velvet,  in  a  loom  with  three  treadles ;  two  of  which  separate 
and  depress  the  woollen  warp,  and  the  third  raises  the  hair-warp,  whereupon  the  weaver, 
throwing  the  shuttle,  passes  the  woof  between  the  woollen  and  hair  warp ;  afterwards, 
laying  a  brass  broach  or  needle  under  that  of  the  hair,  he  cuts  it  with  a  knife  (see 
Fustian)  destined  for  that  use,  running  its  fine  slender  point  alons:  in  the  hollow  of  the 
guide-broach,  to  the  end  of  a  piece  extended  upon  a  table.  Thus  the  surface  of  the 
plush  receives  its  velvety  appearance.     This  stuff  is  also  made  of  cotton  and  silk. 

POINT  NET  is  a  style  of  lace  formerly  much  in  vogue,  but  rtbw  superseded  by  the 

bobbin-net  manufacture. 

1X)LYCHR0MATE  {Polychromate,    or    chrysammic  acid\  a  new  compound  from 

which  a  variety  of  colours  may  be  prepared. 

Chrysamraic  acid,  if  such  be  the  acid  here  alluded  to,  has  been  known  hitherto  only 
to  theehemist  as  the  result  of  the  action  of  nitric  acid  upon  powdered  aloes.  Obtained 
by  this  process,  chrysammic  acid  appears  in  golden  crystals.  The  salts  of  compounds 
of  this  acid  are  remarkable  for  their  brilliancy  of  colour ;  but  their  application  in  the 
arts  is  perfectly  new.  . ,       , 

PORCELAIN,    is  the  finest  kind  of  pottery-ware.     It  is  considered  under  that 

title. 

The  articles  in  the  Exhibition  under  the  head  Statuary  Porcelain,  including  Parian, 
Carrara,  (fee,  are  produced  by  "casting."  As  the  most  direct  method  of  illustrating  this 
process,  let  us  suppose  the  object  under  view  to  be  a  figure  or  group,  and  this  we  will 
assume  to  be  2  feet  high  in  the  model.  The  cl?iy,  which  is  used  in  a  semi-liquid  state,  about 
the  consistency  of  cream,  and  called  "slip,"*^is  poured  into  the  moulds  forming  the  va- 
rious parts  of  the  subject  (sometimes  as  many  as  fifty):  the  shrinking  that  occurs  before 
these  casts  can  be  taken  out  of  the  mould,  which  is  caused  by  the  absorbent  nature  of 
the  plaster  of  which  the  mould  is  composed,  is  equal  to  a  reduction  of  one  inch  and  a 
half  in  the  height  These  casts  are  then  put  together  by  the  "figure-maker,"  the  seams 
(consequent  upon  the  marks  caused  by  the  subdivisions  of  the  moulds)  are  then  carefully 
removed,  and  the  whole  worked  upon  to  restore  the  cast  to  the  same  degree  of  finish  as 
the  original  model.  The  work  is  then  thoroughly  dried,  to  be  in  a  fit  state  for  firing, 
as,  if  put  in  the  oven  while  damp,  the  sudden  contraction  consequent  upon  the  great 
degree  of  heat  instantaneously  applied  would  be  very  liable  to  cause  it  to  crack;  in 
the  process  it  again  suffers  a  further  loss  of  one  inch  and  a  half  by  evaporation,  and  it 
is  now  but  1  foot  9  inches.  Again  in  the  "firing"  of  the  bisque  oven,  its  most  severe 
ordeal,  it  is  diminished  3  inches,  and  is  then  but  18  inches  high,  being  6  inches  or  one 
fourth  less  than  the  original.  Now,  as  the  contraction  should  equally  affect  every  por- 
tion of  the  details  of  the  work,  in  order  to  realize  a  faithful  copy,  and  as  added  to  this 
contingency  are  the  risks  in  the  oven  of  being  "  over-fired,"  by  Avliich  it  would  be 
melted  into  a  mass,  and  of  being  "short-fired,"  by  which  its  surface  would  be  im- 
perfect, it  is  readily  evident  that  a  series  of  difficulties  present  themselves  which 
require  considerable  practical  experience  successfully  to  meet  The  moulds  are  made 
of  plaster  of  Paris,  which,  when  properly  prepared,  has  the  property  of  absorbing  water 
so  effectually  that  the  moisture  is  extracted  from  the  clay,  and  the  ware  is  enabled  to 
leave  the  mould,  or  "  deli  ver  "  with  care  and  rapidity.  Prior  to  use  the  plaster  (gypsum) 
is  put  into  long  troughs,  having  a  fire  running  underneath  them,  hy  which  means  the 
water  is  drawn  off,  and  it  remains  in  a  state  of  soft  powder;  and  if  its  own  proportion 
of  water  be  again  added  to  it,  it  will  immediately  set  into  a  firm  compact  body,  which 
is  the  case  when  it  is  mixed  to  form  the  mould. 
The  following  are  the  degrees  of  temperature  in  which  the  different  branches 

work : — 

3M2 


IT  r. 


,^^y|||^ 


452 


PORCELAIN. 


PORCELAIN. 


453 


II 


IP:., 


|l/v_-,.; 

1*'    "i. 


Plate-makers'  hothouse 
Dish-makers'  hothouse 
I^rinters'  shop 
Throwers*  hothouse 


108®  Fahr. 
106      „ 

90 

98 


fi 


The  branches  against  which  the  temperature  of  the  hothouse  is  placed,  require  that 
heat  for  drying  their  work  and  getting  it  oflF  their  moulds.  The  outer  shops  in  which 
they  work  may  be  from  five  to  ten  degrees  less. 

Variety  of  vases,  garden  pots,  and  articles  of  ordinary  use. 

Ancient  font^  from  the  original  in  Winchester  Cathedral. 

The  Portland  jug.     Lily  of  the  valley  jug.     The  acanthus  garden  vase. 

Fine  porcelain. 

A  vase  of  Etruscan  form,  with  chased  and  burnished  gold  ornaments  on  a  blue  ground, 
decorated  with  floral  wreaths  enamelled,  in  colours,  Ac,  with  pedestal  40  inches  high. 

A  variety  of  ornamental  vases,  chased  and  gilded  with  various  designs  and  otherwise. 

Verulam  bottles,  ribbon  wreath,  and  group  of  flowers,  turquoise  ribbon,  and  group 
of  flowers ;  and  gold  lattice. 

Large  tripod  for  flower  stand,  blue  ground  decorated  in  chased  and  burnished  gold. 

The  Dove  tazze  and  pedestal.  The  birds  and  embossments  in  solid  gold,  chased 
turquoise  ground  and  floral  wreath,  <fec.  Another  with  royal  blue  groimds,  the  details 
of  ornament  in  gold  and  silver. 

Enamel  colours  are  metallic  oxides  incorporated  with  a  fusible  flux ;  gold  precipitated 
by  tin  furnishes  the  crimson,  rose,  and  purple ;  oxides  of  iron  and  chrome  produce  reds; 
the  same  oxides  yield  black  and  brown,  also  obtained  from  manganese  and  cobalt ; 
orange  is  from  oxides  of  uranium,  chrome,  antimony,  and  iron ;  greens  from  oxides  of 
chrome  and  copper;  blue  from  oxides  of  cobalt  and  zinc.  The  fluxes  are  borax,  flint, 
oxides  of  lead,  <fcc.  They  are  worked  in  essential  oils  and  turpentine,  and  a  very  great 
disadvantage  under  which  the  artist  labours,  is  that  the  tints  upon  the  palette*  are  in 
most  cases  different  from  those  they  assume  when  they  have  undergone  the  necessary 
heat,  which  not  only  brings  out  the  true  colour,  but  also,  by  partially  softening  the  glaze 
and  the  flux,  causes  the  colour  to  become  fixed  to  the  ware.  This  disadvantage  will  be 
inmoediately  apparent  in  the  case  where  a  peculiar  delicacy  of  tint  is  required,  as  in 
flesh  stones  for  instance.  But  the  difiiculty  does  not  end  here,  for  as  a  definite  heat 
can  alone  give  to  a  colour  a  perfect  hue,  and  as  the  colour  is  continually  varvirfg  with 
the  different  stages  of  graduated  heat,  another  risk  is  incurred,  that  resulting  from 
the  liability  of  it«  receiving  the  heat  in  a  greater  or  less  degree,  termed  "over-fired" 
and  "short-fired."  As  an  instance  of  its  consequence,  we  cite  rose  colour  or  crimson, 
which  when  used  by  the  painter  is  a  dirty  violet  or  drab ;  during  the  process  of  firing 
it  gradually  varies  with  the  increase  of  heat  from  a  brown  to  a  dull  reddish  hue,  and 
from  that  progressively  to  its  proper  tint.  But  if  by  want  of  judgment  or  inattention 
of  the  fireman  the  heat  is  allowed  to  exceed  that  point,  the  beauty  and  brilliancy  of  the 
colour  are  destroyed  beyond  remed}',  and  it  becomes  a  dull  purple.  On  the  other  hand, 
should  the  fire  be  too  slack,  the  colour  is  presented  in  one  of  its  intermediate  stages) 
as  already  described,  but  in  this  case  extra  heat  will  restore  it  Nor  must  we  forget  to 
allude  to  casualties  of  cracking  and  breaking  in  the  kilns  by  the  heat  being  increased 
or  withdrawn  too  suddenly,  a  risk  to  which  the  larger  articles  are  peculiarly  liable. 
These  vicissitudes  render  enamel  painting  in  its  higher  branches  a  most  unsatisfactory 
and  disheartening  study,  and  enhance  the  value  of  those  productions  which  are  really 
successful  and  meritorious. 

There  are  two  distinct  methods  of  printing  in  use  for  china  and  earthenware  ;  one  is 
transferred  on  the  bisque,  and  is  the  method  by  which  the  ordinary  printed  ware  is 
produced,  and  the  other  is  transferred  on  the  glaze.  The  first  is  called  "  press  printing," 
and  the  latter  "bat  printing."  The  engraving  is  executed  upon  copper  plates,  and  for 
press  printing  is  cut  very  deep,  to  enable  it  to  hold  a  sufficiency  of  colour  to  give  a  firm 
and  full  transfer  to  the  ware.  The  printer's  shop  is  furnished  with  a  brisk  stove,  having  an 
iron  plate  on  the  top  immediately  over  the  fire,  for  the  convenience  of  warming  the  colour 
while  being  worked ;  also  a  roller  press  and  tubs.  The  printer  has  two  female  assistants 
called  "  transferers,"  and  also  a  girl  called  a  "  cutter."  ITie  copperplate  is  charged  with 
colour  mixed  with  thick  boiled  oil  by  means  of  a  knife  and  "  dabber,"  while  held  on  the 
hot  stove  plate  for  the  purpose  of  keeping  the  colour  fluid ;  and  the  engraved  portion 
being  filled,  the  superfluous  colour  is  scraped  off  the  surface  of  the  copper  by  the  knife 
which  is  further  cleaned  by  being  rubbed  with  a  boss  made  of  leather.  A  tliick  firm 
oil  is  required  to  keep  the  different  parts  of  the  design  from  flowing  into  a  mass,  or  be- 
coming confused  while  under  the  pressure  of  the  rubber,  in  the  process  of  transferring. 
A  sheet  of  paper  of  the  necessary  size  and  of  a  peculiarly  thin  texture,  called  "pottery 
tissue,"  after  being  saturated  with  a  thin  solution  of  soap  and  water,  is  placed  upon  the 
copper  plate,  and  being  put  under  the  action  of  the  press,  the  paper  is  carefully  drawn  off 
again,  (the  engraving  being  placed  on  the  stove,)  bringing  with  it  the  colour  by  which 


the  plate  was  charged  constituting  the  pattern.  This  impression  is  given  to  the  "  cutter, 
who  cuts  away  the  superfluous  paper  about  it ;  and  if  the  pattern  consists  of  a  border  and 
a  centre  the  border  is  separated  from  the  centre,  as  being  more  convenient  to  fit  to  the 
ware  when  divided.  It  is  then  laid  by  a  transferer  upon  the  ware  and  rubbed  first  with 
a  small  piece  of  soaped  flannel  to  fix  it^  and  afterwards  with  a  rubber  formed  of  rolled 
flannel  The  rubber  is  applied  to  the  impression  very  forcibly,  the  friction  causing  the 
colour  to  adhere  firmly  to  the  bisque  surface,  by  which  it  is  partially  imbibed ;  it  is  then 
immersed  in  a  tub  of  water,  and  the  paper  washed  entirely  away  with  a  sponge,  the 
colour,  from  its  adhesion  to  the  ware  and  being  mixed  with  oil,  remaining  unatfocted- 
It  is  now  necessary,  prior  to  "  glazing,"  to  get  rid  of  this  oil,  which  is  done  by  submitting 
the  ware  to  heat  in  what  are  called  "  hardening  kilns,"  sufficient  to  destroy  it  and  leave 
the  colour  pure.  This  is  a  necessary  process  as  the  glaze,  being  mixed  with  water, 
would  be  rejected  by  the  print,  while  the  oil  remained  in  the  colour. 

The  "bat  printing"  is  done  upon  the  glaze,  and  the  engravings  are  for  this  style  ex- 
ceedingly fine,  and  no  greater  depth  is  required  than  for  ordinary  book  engravings. 
The  impression  is  not  submitted  to  the  heat  necessary  for  that  in  the  bisque,  and  the 
medium  of  conveying  it  to  the  ware  is  also  much  purer.  The  copper  plate  is  first 
charged  with  linseed  oil,  and  cleaned  off  by  hand,  so  that  the  engraved  portion  only  re- 
tains it  A  preparation  of  glue  being  run  upon  flat  dishes  about  a  quarter  of  an  inch 
thick,  is  cut  to  the  size  required  for  the  subject,  and  then  pressed  upon  it  and  being 
immediately  removed,  draws  on  its  surface  the  oil  with  which  the  engraving  was  filled. 
The  glue  is  then  pressed  upon  the  ware,  with  the  oiled  part  next  the  glaze,  and  being 
again  removed,  the  design  remains ;  though,  being  in  a  pure  oil,  scarcely  perceptible. 
Colour  finely  ground  is  then  dusted  upon  it  with  cotton  wool,  and  a  sufficiency  adhering 
to  the  oil  leaves  the  impression  perfect,  and  ready  to  be  fired  in  the  enamel  kilns. 

We  shall  refer  in  the  first  place  to  the  preparation  of  the  two  principal  ingredients, 
flint  and  natural  clay  for  the  use  of  the  potter,  and  afterwards  to  the  blending  of  them. 
The  flint  stones  are  first  calcined,  and  this  is  effected  in  a  kiln  similar  to  that  used  for 
lime  burning.  These  stones  are  separated  by  alternate  layers  of  coal,  and  the  burning 
usually  occupies  about  24  hours.  The  flints  are  then  very  white  and  very  brittle,  and 
ready  to  be  crushed  by  the  "  stamper,"  a  machine  composed  of  upright  shafts  of  wood, 
6  feet  long  and  about  8  inches  square,  heavily  loaded  with  iron  at  the  lower  end,  which, 
by  means  of  applied  power,  are  made  to  rise  and  fall  in  succession  on  the  flints,  contained 
m  a  strong  grated  box.  It  is  then  removed  to  the  grinding  vats,  which  are  from  12  to 
14  feet  in  diameter,  and  4  feet  deep,  paved  with  chert  stone,  large  blocks  of  which  being 
also  worked  round  by  arms  connected  with  a  central  vertical  shaft,  propelled  by  an 
engine,  become  a  powerful  grinding  medium.  Tliis  peculiar  stone  is  used  because  of 
its  chemical  affinity  to  the  fluid,  which  therefore  suffers  no  deterioration  from  the  mix- 
ture of  the  abraded  particles,  which  necessarily  result  from  the  friction,  a  matter  of  seri- 
ous moment  In  these  vats  the  fluid  is  ground  in  water,  until  it  attains  the  consistency 
of  thick  cream,  when  it  is  drawn  off  and  conveyed  by  troughs  into  the  washing  chamber. 
Here  it  undergoes  a  further  purification,  more  water  is  added,  and  it  is  kept  in  a  state 
of  gentle  agitation  by  means  of  revolving  arms  of  wood,  thus  keeping  the  finer  particles 
in  suspension  while  the  liquid  is  again  drawn  away  in  pipes  to  a  tank  below.  The 
sediment  is  afterwards  reground.  . 

The  cleansing  process  is  not  yet  complete,  for  when  the  fluid  has  passed  into  these 
tanks  to  about  half  their  depth,  they  are  filled  up  with  water,  which  is  repeatedly 
changed,  until  it  is  considered  sufficiently  fine  and  free  from  all  foreign  matters;  it  is  then 
fit  for  use.  The  clay  requires  no  grinding.  It  is  received  from  the  merchants  pre- 
pared, and  has  merely  to  be  mixed  with  water  till  it  attains  the  same  degree  of  fluidity 
as  the  flints.  The  next  stage  is  the  "mixing,"  for  which  purpose  the  different  "slips 
(the  technical  term  of  the  fluid  clays,  Ac.)  are  successively  run  off  into  the  blending 
reservoir,  against  the  inner  side  of  which  are  "gauging  rods,"  by  which  the  necessary 
proportion  of  each  material  is  regulated.  The  mixture  is  now  passed  into  other  reser- 
voirs, through  fine  sieves,  on  "  lawns"  woven  of  silk,  and  containing  300  threads  to  the 
square  inch.  A  pint  of  slip  of  Dorsetshire  or  Devonshire  clay  weighs  24  ounces,  of 
proper  consistence ;  of  Cornish  clay  26  ounces ;  and  of  flint  32  ounces.  Finally  the 
slip  is  conveyed  to  a  series  of  large  open  kilns  heated  underneath  by  means  of  flues,  and 
about  9  inches  deep.  The  excessive  moisture  is  thus  evaporated,  and  in  about  24  hours 
the  mixture  becomes  tolerably  firm  in  substance.  It  is  then  cut  into  large  blocks  and 
conveyed  to  an  adjoining  building  to  undergo  the  process  of  "  milling."  The  mill  is  in  the 
form  of  a  hollow  cone  inverted,  with  a  square  aperture  or  tube  at  the  lower  part  In  the 
centre  is  a  vertical  shaft  set  with  broad  knives.  When  this  shaft  is  in  action  (worked 
by  steam  power),  the  soft  clay  is  thrown  downwards,  being  alternately  cut  and  pressed 
until  it  exudes  from  the  aperture  at  the  bottom  in  a  perfectly  plastic  state,  and  ready 
for  the  hand  of  the  potter. 

In  enamelling,  ground-laying  is  the  firet  process  in  operating  on  all  designs  to  which 
it  is  applied ;  it  is  extremely  simple,  requiring  principally  lightness  and  delicacy  of 


lii-^       I 


i|(T 


f  ! 


\  I 


li  I 


I 


m 


454 


PORCELAIN. 


hand.  A  coat  of  boiled  oil  adapted  to  the  purpose  being  laid  upon  the  ware  with  a 
pencil,  and  afterwards  levelled,  or  as  it  is  technically  termed  "bossed,"  until  the  surface 
13  perfectly  uniform ;  as  the  deposit  of  more  oil  on  one  part  than  another  would  cause  a 
proportionate  increase  of  colour  to  adhere,  and  consequently  produce  a  variation  of  tint 
This  being  done,  the  colour  which  is  in  a  state  of  fine  powder,  is  dusted  on  the  oiled 
surface  with  cotton  wool ;  a  sufficient  quantity  readily  attaches  itself  and  the  superfluity 
is  cleared  off  by  the  same  medium.  If  it  be  requisite  to  preserve  a  panel  ornament  or 
any  object  white  upon  the  ground,  an  additional  process  is  necessary,  called  "stencilling." 
The  stencil  (generally  a  mixture  of  rose-pink,  sugar,  and  water)  is  laid  on  in  the  form 
desired  with  a  pencil,  so  as  entirely  to  protect  the  surface  of  the  ware,  from  the  oil,  and 
the  process  of  "grounding,'*  as  previously  described,  ensues.  It  is  then  dried  in  an  oven 
to  harden  the  oil  and  colour,  and  immersed  in  water,  which  penetrates  to  the  stencil, 
and  softening  the  sugar,  is  then  easily  washed  off,  carrying  with  it  any  portion  of  colour 
or  oil  that  may  be  upon  it,  and  leaving  the  ware  perfectly  clean.  It  is  sometimes 
necessary  where  great  depth  of  colour  is  required,  to  repeat  these  colours  several  times. 
The  "  ground-la}'ers"  do  generally,  and  should  always,  work  with  a  bandage  over  the 
mouth  to  avoid  inhaling  the  colour-dust,  much  of  which  is  highly  deleterious.  Bossing 
is  the  term  given  to  the  process  by  which  the  level  surfaces  of  various  colours  so  exten- 
sively introduced  upon  decorated  porcelain  are  effected.  The  "  boss  "  is  made  of  soft 
leather. 

The  process  of  gilding  is  as  follows : — The  gold  (which  is  prepared  with  quicksilver 
and  flux)  when  ready  for  use,  appears  a  black  dust ;  it  is  used  with  turpentine  and  oils 
similar  to  the  enamel  colours,  and  like  them  worked  with  the  ordinary  camels'  hair 
pencil.  It  flows  very  freely,  and  is  equally  adapted  for  producing  broad  massive 
bands  and  grounds,  or  the  finest  details  of  tlie  most  elaborate  design. 

To  obviate  the  difficulty  and  expense  of  drawing  the  pattern  on  every  piece  of  a  ser- 
vice, when  it  is  at  all  intricate,  a  "  pounce"  is  used,  and  the  outline  dusted  through  with 
charcoal, — a  method  which  also  secures  uniformity  of  size  and  shape.  Women  are 
precluded  from  working  at  this  branch  of  the  business,  though  from  its  simplicity  and 
lightness  it  would  appear  so  well  adapted  for  them.  Firing  restores  the  gold  to  its 
proper  tint,  which  firet  assumes  the  character  of  "  dead  gold,"  its  after  brilliancy  being 
the  result  of  another  process  termed  "  burnishing." 

The  process  of  bisque  firing  is  as  follows :  the  ware  being  finished  from  the  hands  of 
the  potter  is  brought  by  him  upon  boards  to  the  "gi'cen-house,"  so  called  from  its  being 
the  receptacle  for  ware  in  the  "  green  "  or  unfired  state.  It  is  here  gradually  dried 
for  the  ovens;  when  ready  it  is  carried  to  the  "sagger-house"  in  immediate  connection 
with  the  oven  in  which  it  is  to  be  fired,  and  here  it  is  placed  in  the  "  saggers ;"  these 
are  boxes  made  of  a  peculiar  kind  of  clay  (a  native  marl)  previously  fired,  and  infusible 
at  the  heat  required  for  the  ware,  and  of  form  suited  to  the  articles  thc}'^  are  to  contain. 
A  little  dry  pounded  flint  is  scattered  between  them  of  china,  and  sand  of  earthenware 
to  prevent  adhesion.  The  purpose  of  the  sagger  is  to  protect  the  ware  from  the  flames 
and  smoke,  and  also  for  its  security  from  breakage,  as  in  the  clay  state  it  is  exceedingly 
brittle,  and  when  dry,  or  what  is  called  white,  requires  great  care  in  the  handling.  A 
plate  sagger  will  hold  twenty  plates  placed  one  on  the  other  of  earthenware,  but  china 
plates  are  fired  separately  in  "setters"  made  of  their  respective  forms.  The  "setters'* 
for  china  plates  and  dishes  answer  the  same  purpose  as  the  saggers,  and  are  made  of 
the  same  clay.  They  take  in  one  dish  or  plate  each,  and  are  "  reared"  in  the  oven  in 
•*  bungs,"  one  on  the  other. 

The  hovels  in  which  the  ovens  are  built  form  a  very  peculiar  and  striking  feature  of 
the  pottery  towns,  and  forcibly  arrest  the  attention  and  excite  the  surprise  of  the  stranger, 
resembling  as  they  closely  do  a  succession  of  gigantic  bee-hives.  Tliey  are  constructed 
of  bricks  about  40  feet  in  diameter,  and  about  35  feet  high,  with  an  ai)erture  at  the  top 
for  the  escape  of  the  smoke.  The  "  ovens"  are  of  a  similar  form,  about  22  feet  in  diameter, 
and  from  18  to  21  feet  high,  heated  by  fire-places  or  "mouths,"  about  nine  in  number, 
built  externally  around  them.  Flues  in  connection  with  these  converge  under  tlie 
bottom  of  the  oven  to  a  central  opening,  drawing  the  flames  to  this  point,  where  they 
enter  the  oven  ;  other  flues  termed  "  bags"  pass  up  the  internal  sides  to  the  height  of 
about  4  feet,  thus  conveying  the  flames  to  the  upper  part. 

When  "setting  in"  the  oven,  the  firemen  enter  by  an  opening  in  the  side,  carrying  the 
saggers  with  the  ware  placed  as  described ;  these  arft  piled  one  upon  another,  from 
bottom  to  top  of  the  oven,  care  being  taken  to  arrange  them  so  that  they  may  receive 
the  heat  (which  varies  in  different  pai-ts)  most  suited  to  the  articles  they  contain.  This 
being  continued  till  the  oven  is  filled,  the  aperture  is  then  bricked  up.  The  firing  of 
earthenware  bisque  continues  sixty  hours,  and  of  china  forty-eight. 

The  quantity  of  coals  necessary  for  a  "bisque"  oven  is  from  16  to  20  tons;  for  a 
"glost"  oven  from  4^  to  6  tons. 

The  ware  is  allowed  to  cool  for  two  days,  when  it  is  drawn  in  the  state  technically 
called  "  biscuit"  or  bisque,  and  is  then  ready  for  "glazing,"  except  when  required  for 


PORCELAIN. 


455 


printing  or  a  common  stjle  of  painting,  both  of  which  processes  are  done  on  the  bisque 

^'A'l!^geTroportk»n  of  circular  articles  not  requiring  ornament  or  relief  beyond  pUin 
cufved  furtaces  are  "  thrown  and  turned."  Few  are  unacquainted  with  the  wonder- 
working ^wers  of  the  potter's  wheel.  A  ball  of  clay  is  placed  on  the  centre  of  the 
revolving  block,  and  by  the  simplest  manipulation  is  made  to  spring  at  once  into  form 
Ind  character,  assuming  at  the  operator's  will  any  contour  of  which  a  circular  vessel  is 
capable,  the  plastic  clay  being  formed  or  transformed  with  an  ease  and  rapidi^amost 
incredible.     Every  piece,  when  made,  is  cut  oflf  the  block  by  a  wire  bemg  passed  under 

'^'When  the  "  thrown  ware"  is  sufficiently  dry,  it  is  transferred  to  the  hands  of  the 
"  turner  "  whose  province  it  is  to  form  the  curves  more  truly  and  sharply,  and  to  impart 
a  uniform  smoothness  and  polish  to  the  surface.  This  process  resemb  es  that  of  ordi- 
nary wood  turning,  but  from  the  nature  of  the  materia  is  executed  ^ith  much  greater 
Lility  The  vessel  is  fitted  upon  a  block  or  "  churn  attached  to  the  lathe,  and  the 
turning  is  performed  by  thin  iron  tools  few  in  number  and  simple  m  form^ 

Seles  o?Ihis  class  which  require  handles  are  passed  from  the  lathe  to  the  "handler." 
Thtse  useful  adjuncts  are  made  by  pressure  in  moulds  of  plaster  of  Pans,  and  after  being 
sufficiently  dried,  are  fixed  on  the  vessel  with  "slip."  The  adhesion  is  ^o  immediate 
lE  mo^st  cases  the  article  may  be  lifted  up  by  the  handle  before  it  has  left  the  hand 
of  the  operator.  When  the  handle  is  fitted,  the  superfluous  slip  which  exudes  fronj  the 
iunction  after  the  parts  have  been  pressed  together,  is  removed  with  a  sponge,  and  the 
iurfaces  worked  together,  and  smoothed  round  with  a  small  tool :  the  article  is  then 
finXd  unless  a  "spout "  or  lip  is  required,  as  in  the  case  of  teapots,  jugs,  Ac  These 
are  made  and  attached  in  the  same  manner  as  handles.  -    a  '    ^\..  ^avJona 

New  ca>npodtions  for  glazing  earthenware.-The  materials  eo™Pri«ed  »n  ^^^.^^\'^^l 
dazes  commonly  used  for  china  and  earthenware,  are  Cornish  stone,  flmt,  jtite  lead^ 
llass  whiting,  L.  These  having  been  ground  together  in  proper  proportions  to  the 
fonltence  of 'milk  form  the  glaze.  The  process  is  eftected  in  \«2i!.^t.^3^Tbi 
«  dippine-houses,"  (china  and  earthenware  bemg  kept  separate)  fatted  up  with  tubes 
for  the  glaze,  and  stages  for  the  reception  of  the  ware  when  dipped,  uix)n  which  it  u 
dried  afd  heated,  generally  by  means  of  a  large  iron  stov;e  or  "cockle,"  from  which 
iron  ptpes  extendiifg  in  various  directions  convey  the  heat  throughout  the  whole  extent 
of  the  "  houses."  Each  dipper  is  provided  with  a  tub  of  glaze,  m  which  he  imnaersea 
the  bisque  ware.  We  may  note  the  results  of  practice  and  experience  in  imparting  a 
facility  and  dexterity  of  handling  so  necessary  to  perfection  m  this  process.  The  ware 
is  held  so  that  as  small  a  portion  as  possible  shall  be  covered  by  the  fingers ;  it  is  then 
plunged  in  the  glaze,  which  by  a  dexterous  jerk  is  made  not  only  to  cover  the  entu-e 
pied  but  at  thi  same  time  so  disperses  it,  that  an  equal  and  level  portion  is  disposed 
Sver  the  whole  surface,  which,  being  porous,  imbibes  and  retains  it  1  he  ware  is  handed 
to  the  dipper  by  a  boy,  and  another  removes  it  when  dipped  to  the  drymg  or  hot- 
house." The  glaze  is  opaque  till  fired,  so  that  the  design  of  pattern  executed  on  the 
bisque  is  completely  hid  after  dipping  till  they  have  been  submitted  to  the  glost  fire. 
An  able  workman  will  dip  about  700  plates  m  a  day. 

In  1751  Dr  Wale  established  a  manufactory  in  Worcester,  under  the  name  of  the 
«  Worcester  Porcelain  Company,"  and  to  him  appears  to  be  due  the  idea  of  printing  upon 
porcelain,  the  transferring  of  printed  patterns  to  biscuit  ware  as  usually  adopted.  From 
a  magazine  in  the  Museum  of  Practical  Geology  decorated  with  a  portrait  of  Frederick 
the  Great,  the  date  ofthis  process  appears  to  be  17  57.  , .      , .         ;, 

The  original  Worcester  Company  principally  confined  themselves  to  making  blue  and 
white  wai'e  in  imitation  of  that  of  Nankin,  and  in  producing  copies  of  the  Japanese 

^^Cockwortly  of  Plymouth  appears  to  have  carried  on  the  business  of  a  potter  in 
Worcester  until  1783,  when  the  manufactory  passed  into  the  possession  of  Mr.  Thomaa 

Stone  china  differs  from  the  "tender  porcelain,"  as  the  English  ware  is  termed,  it 
bein<'  a  fused  body ;  the  alkali  of  the  clays  employed  being  by  the  heat  of  the  furnace 
made  to  combine  "with  the  silica  and  alumina.  Enamel  colours  are  such  as  consist  of 
metallic  oxides  combined  with  an  alkaline  flux,  which,  when  exposed  to  a  high  tempera 

ture,  forms  a  perfect  glass.  .  .      -^  •  •  j  ^ 

When  the  ware  leaves  the  hands  of  the  painters,  gildei-s,  Ac,  it  is  carried  to  a  receir- 
ine-room  in  connexion  with  the  "enamel-kilns."  The  firemen  select  the  ware  frona 
this  room,  according  to  the  degree  of  heat  they  may  require,  and  place  it  m  that  part  of 
the  kiln  most  likely  to  secure  it  The  different  articles  are  ranged  upon  stages  con- 
structed of  "  slabs  "  or  "  bats  "  supported  on  props  all  made  of  fired  clay.  Tlie  time  of 
firing  is  from  6  to  7  hours  according  to  the  size  of  the  kiln,  and  whether  it  contains 
auv  articles  of  unusual  size  and  hazard,  in  which  case  the  heat  is  brought  forward  very 
gradually      The  ♦♦groimd-laymg"  being  executed  with  colours  less  fusible  than  those 


t  n 


'Hf^ 


456 


PORTER. 


employed  by  the  painters,  the  ware  so  decorated  is  fired  in  separate  kilns  at  a  highei 
temperature,  a  level  glossy  surface  being  a  great  desideratum ;  and  as  gold  is  often  used 
m  rehef  upon  the  "grounds,"  it  would  be  liable  to  sink  and  lose  its  lustre  unless  the 
under  colour  had  received  a  greater  degree  of  heat  than  is  required  by  the  gilding.  The 
kilns  are  built  of  large  fired  clay  slabs  made  expressly  for  the  purpose.  They  are  about 
8  feet  SIX  inches  wide,  7  feet  6  inches  high,  and  6  feet  6  inches  long,  with  circular  tops, 
Jia\ang  flues  beneath*  and  around  them.  The  fire-places  or  "mouths"  are  at  the  sides, 
and  the  flames  passing  through  the  flues,  encircle  the  kiln  externally.  Great  care  is 
taken  to  prevent  the  admission  of  smoke  or  flame  into  the  body  of  the  kilns,  the  fronts 
of  which  are  closed  with  iron  doors  having  in  them  small  apertures,  through  which 
the  firemen  occasionally^  draw  "  trails"  of  colour  made  upon  small  pieces  of  ware,  and 
thus  ascertain  to  a  certain  extent  the  progress  of  the  heat.  This  is  a  material  assistance, 
but  being  drawn  from  one  part  only,  still  leaves  a  task  requiring  great  care  and  nicety 
of  judgment  to  manage  successfully.  Gold,  if  not  sufliciently  fired,  will  wipe  off,  and 
if  over  fired  will  not   "  burnish,"  and  the  gilding  has  to  be  repeated. 

Penthesilea,  Queen  of  the  Amazons,  slam,  supported  hy  Achilles,  2'hymhrean  Apollo  and 
Cassandra.  Iris  and  Alcuraon.  The  class  of  work  to  which  these  examples  belong  may 
be  ranked^under  the  head  of  Reproductive  Art.  The  historical,  mythical,  and  domestic 
events  which  they  illustrate,  form  vivid  and  instructive  records  of  the  manners  and  cus- 
toms of  the  ancients.  The  original  bases  which  have  formed  the  material  in  this  series 
are  amougst  the  earliest  memorials  of  Hellenic  civilization.  The  date  of  their  production 
extends  from  the  second  to  the  fifth  century  of  the  Christian  era.  The  diversity  and 
elegance  of  their  forms  bear  conclusive  evidence  of  the  grace  and  beauty  with  which  a 
refined  and  cultivated  intelligence  can  mould  the  objects  which  minister  to  the  humble 
and  familiar  purposes  of  household  wants. 

Their  application  was  chiefly  to  domestic  requirements;  and  it  being  a  custom  con- 
nected with  the  right  of  burial  to  deposit  within  the  sepulchre  such  objects  as  the  deceased 
had  most  highly  valued  during  life,  the  interment  of  a  large  number  of  these  mortuary 
treasures,  which  so  graphically  illustrate  Greek  art  and  life,  resulted.  To  this  we  owe 
the  preservation  of  so  interesting  and  numerous  a  series  of  these  valuable  mementos  of 
archaic  taste  and  skill.  They  are  composed  of  red  clay,  the  figure  and  ornamental  com- 
position being  executed  on  a  dark  liquid  pigment,  worked  in  quick-drying  oils,  and 
submitted  to  a  considerable  degree  of  heat,  to  secure  eff^ectual  adhesion.  Amongst  the 
earliest  designs  are  placed  these  in  which  the  black  selhouette-like  figures  are  painted 
upon  the  red  or  buff  ground.  These  vases  with  the  figures  and  ornaments  in  a  red  on  a 
black  ground  mark  the  period  when  Greek  art  was  at  its  zenith. 

In  reference  to  the  forms  of  these  vases  it  may  be  instructive  to  remark  that  a  careful 
analysis  of  the  best  examples  in  the  British  Museum  proves  that  every  curve  is  the  seg- 
ment of  a  circle ;  and  it  has  been  mathematically  demonstrated  that  even  in  instances 
where  the  most  irregular  diversity  of  outline  has  been  presented,  that  every  curve  has 
been  circular  and  none  elliptical. 

PORPHYRY,  is  a  compound  mineral  or  rock,  composed  essentially  of  a  base  of 
hornstone,  interspersed  with  crj-stals  of  felspar.  It  frequently  contams  also  quartz, 
mica,  and  hornblende.  That  most  esteemed  is  the  ancient  porphyry  of  Egypt,  with 
a  ground  of  a  fine  red  colour  passing  into  purple,  having  snow-white crjstals  of  felspar 
imbedded  in  it.  Most  beautiful  specimens  of  it  are  to  be  seen  in  the  antique  colossal 
statues  in  the  British  Museum. 

Porphyry  occurs  in  Arran,  and  in  Perthshire  between  Dalnacaidoch  and  Tummel 
brids:e.     It  is  much  used  for  making  slabs,  mullers,  and  mortars. 

PORTER  is  a  malt  liquor,  so  called  from  being  the  favorite  beverage  of  the  porters 
and  workpeople  of  the  metropolis  and  other  large  towns  of  the  British  empire ;  it  is  char- 
acterized by  its  dark-brown  color,  its  transparency,  its  moderately  bitter  taste,  and  pecu- 
liar aromatic  flavor,  which,  along  with  its  tonic  and  intoxicating  qualities,  make  it  be 
keenly  relished  by  thirsty  palates  accustomed  to  its  use.  At  first  the  essential  distinction 
of  porter  arose  from  its  wort  being  made  with  highly-kilned  brown  malt,  while  other  kinds 
of  beer  and  ale  were  brewed  from  a  paler  article ;  but  of  late  years,  the  taste  of  the 
public  having  run  in  favor  of  sweeter  and  lighter  beverages,  the  actual  porter  is  brewed 
with  a  less  proportion  of  brown  malt,  is  less  strongly  hopped,  and  not  allowed  to  get  hard 
by  long  keeping  in  huge  ripening  tuns.  Some  brewers  color  the  porter  with  burnt  sugar ; 
but  in  general  the  most  respectable  concentrate  a  quantity  of  their  first  and  best  wort  to  an 
extract,  in  an  iron  pan,  and  burn  this  into  a  coloring  stuff,  whereby  they  can  lay  claim  to 
the  merit  of  using  nothing  in  their  manufacture  but  malt  and  hops.  The  singular  flavor 
of  good  London  porter  seems  to  proceed,  in  a  great  degree,  from  that  of  the  old  casks 
and  fermenting  tuns  in  which  it  is  prepared.  Though  not  much  addicted  to  vinous 
potations  of  any  kind,  I  feel  warranted  by  long  experience  to  opine,  that  the  porter 
brewed  by  the  eminent  London  houses,  when  drunk  in  moderation,  is  a  far  wholesomer 
beverage  for  the  people  than  the  Ihin  acidulous  wines  of  France  and  Germany. 
See  Beer. 


POTASH. 


457 


PORTLAND  CEMENT,  is  formed  by  calcining  together  limestone  and  some  ar^l- 
laceous  earth,  the  result  being  a  mass  which  most  rapidly  absorbs  a  certain  quantity 
of  water,  and  then  becomes  solid  as  a  hydrous  silicate  of  lime.  Tlie  advantages  oyer 
natural  hydraulic  limes  consist  generally  in  greater  hardness  and  durability,  ansmg 
from  the  mixture  of  material  being  more  perfectly  under  command.  Bricks  cemented 
tocether  by  it  bear  a  pressure  on  the  outermost  brick  of  3  tons ;  being  a  beam  of 
cement.      A  block  of  this  cement  tested  by  the  hydraulic  press  bore  a  pressure  of 

PORTLAND  STONE,  is  a  fine  compact  oolite,  so  named  from  the  island  wheie 
it  is  quarried.     It  is  a  convenient  but  not  a  durable  building  stone. 

POTASH  or  POTASSA.  (Potasse,  Fr. ;  Kali,  Germ.)  This  substance  was  so  named 
from  beinff  prepared  for  commercial  purposes  by  evaporating  in  iron  pots  the  lixivium  of 
the  ashes  of  wood  fuel.  In  the  crude  state  called  potashes,  it  consists  therefore,  of  such 
constituents  of  burned  vegetables  as  are  very  soluble  in  water,  and  fixed  in  the  fire.  The 
potash  salts  of  plants  which  originally  contained  vegetable  acids,  will  be  converted  into 
carbonates,  the  sulphates  will  become  sulphites,  sulphurets,  or  even  carbonates,  accord- 
ing to  the  manner  of  incineration;  the  nitrates  will  be  changed  into  pure  carbonates, 
while  the  muriates  or  chlorides  will  remain  unaltered.  Should  quicklime  be  added  to  the 
solution  of  the  ashes,  a  corresponding  portion  of  caustic  potassa  will  be  introduced  into 
the  product,  with  more  or  less  lime,  according  to  the  care  taken  in  decanting  ofl  the  clear 

ley  for  evaporation.  ,  ,  .»,        -i    •» 

In  America,  where  timber  is  in  many  places  an  incumbrance  upon  the  sod,  it  » 
felled,  piled  up  in  pyramids,  and  burned,  solely  with  a  view  t9  the  manufacture  of 
potashes.  The  ashes  are  put  into  wooden  cisterns,  having  a  plug  at  the  bottom  of 
one  of  the  sides  under  a  false  bottom  ;  a  moderate  quantity  of  water  is  then  poured  on 
the  mass,  and  some  quicklime  is  stirred  in.  AAer  standing  for  a  few  hours,  so  as  to 
take  up  the  soluble  matter,  the  clear  liquor  is  drawn  oflT,  evaporated  to  dryness  in  iron 
pots,  and  finally  fused  at  a  red  heat  into  compact  masses,  which  are  gray  on  the  outside, 

and  pink-colored  within.  ,       .        v       ^v   *-n  tx,^  «.>>»1a 

Pearlash  is  prepared  by  calcining  potashes  upon  a  reverberatory  hearth,  till  the  whole 
oaiboaaceous  matter,  and  the  greater  part  of  the  sulphur,  be  dissipal^l :  then  lixiviatmg 
the  mass,  in  a  cistern  having  a  false  bottom  covered  with  slrav,  evaporating  the  clear  lye 
to  dryness  in  flat  iron  pai^  and  stirring  it  towards  the  end  into  white  lumpy  granu- 

*  1  fil^d  the  best  pink  Canadian  potashes,  as  imported  in  casks  containing  about  5  cwts., 
to  contain  pretty  uniformly  60  per  cent,  of  absolute  potassa ;  and  the  best  pearlashes 
to  contain  50  per  cent.;  the  alkali  in  the  former  being  nearly  in  a  caustic  state;  in  the 

latter,  carbonated.  j>       t.  rru^  ^^.^ 

All  kinds  of  vegetables  do  not  yield  the  same  proportion  of  potassa  Ihe  more 
succulent  the  plan?  the  more  does  it  afford ;  for  it  is  only  in  the  juices  that  the  vegetable 
salts  reside,  which  are  converted  by  incineration  into  alkaline  matter.  Herbaceous 
weeds  are  more  productive  of  potash  than  the  graminiferous  species  or  shrubs,  and  these 
than  trees-  and  for  a  like  reason  twigs  and  leaves  are  more  productive  than  timl)er. 
But  plants  in  all  cases  are  richest  in  alkaline  salt^  when  they  have  arrived  at  maturity. 
The  soil  in  which  th«^y  grow  also  influences  the  quantity  of  saline  matter. 

The  following  Table  exhibits  the  average  product  in  potassa  of  several  plants,  accord- 
ing to  the  researches  of  Vauquelin,  Pertuis,  Kirwau,  and  De  Saussure  :— 


In  1000  parts. 

Pine  or  &r  - 

Poplar 

Trefoil        -       - 

Beechwood- 

Oak      -       -       - 

Boxwood    - 

Willow 

Elm  and  Maple  - 

Wlieat  straw     - 

Barb  of  oak  twigs 


Potassa.  I   In  1000  parts. 


0"45  i  Thistles 


-  0  75 

-  075 

-  l-4i 

-  1-53 
.    2'26 

-  2"8.'» 
390 
390 
420 


Flax  stems 
Small  rushes      - 
Viiie  shoots 
Barley  straw     - 
Dry  beech  bark 
Fern    - 
T^arge  rush 
Stalk  of  maize  - 
Bean  stalks 


Potassa. 

-  500 

-  500 

-  608 

-  5  50 
.  5-80 

-  6-00 
.  6-2G 
.  722 


In  1000  parts. 


Potassa. 


Bastard  chamomile   iAtithe- 

mis  cotula,  L.) 
Sunflower  stalks     -       •       - 
Common  nettle 
Vetch  plant      ...       - 
Thistles  in  full  growth  • 
Dry  straw  of  wheat  before 

earing 


i7'5   Wormwood 
20'0 1  Fumitory  • 


196 

2000 

2503 

2750 

35-37 

4ro 

730 
79-0 


Stalks  of  tobacco,  potatos,  chesnuts  chesnut  husks,  broom,  heath,  furze,  tansy,  son-el, 
vine  leaves,  beet  leaves,  orach,  and  many  other  plants,  abound  in  potash  salt*.  In  Bur- 
eundv  the  well  known  cendres  gr^velees  are  made  by  incinerating  the  lees  of  wine 
pressed  into  cakes,  and  dried  in  the  sun ;  the  ashes  contain  fully  16  per  cent,  of  potassa. 

The  purification  of  pearlash  is  founded  upon  the  fact  of  its  being  more  soluble  m 
water  than  the  neutral  salts  which  debase  it.  Upon  any  given  quantity  of  that  substance, 
in  an  iron  pot,  let  one  and  a  half  times  its  weight  of  water  be  poured,  and  let  a  gentle 
heat  be  applied  for  a  short  time.  When  the  whole  has  again  cooled,  the  bottom  will  be 
encrusted  with  the  salts,  while  a  solution  of  nearly  pure  carbonate  of  potash  will  be 
found  floatino-  above,  which  may  be  drawn  off  clear  by  a  syphon.  The  salts  may  be  after- 
wards thrown  upon  a  filter  of  gravel   If  this  lye  be  diluted  with  6  times  its  bulk  of  water, 

Vol.  IL  3  N 


Ml:    I 

i 


458 


POTASH. 


POTASSIUM. 


459 


mixed  with  as  much  slaked  lime  as  there  was  pearlash  employed,  and  the  mixture  be 
boiled  for  an  hour,  the  potash  will  become  caustic,  by  giving  up  its  carbonic  acid  to  the 
lime.  If  the  clear  settled  lixivium  be  now  syphoned  off,  and  concentrated  by  boiling 
in  a  covered  iron  pan,  till  it  assumes  the  appearance  of  oil,  it  will  constitute  the  common 
caustic  of  the  surgeon,  the potassa  fusa  of  the  shops.  But  to  obtain  potassa  chemically 
pure,  recourse  must  be  had  to  the  bicarbonate,  nitrate,  or  tartrate  of  potassa,  salts 
which,  when  carefully  crystallized,  are  exempt  from  any  thing  to  render  the  potassa 
derived  from  them  impure.  The  bicarbonate  having  been  gently  ignited  in  a  silver 
basin,  is  to  be  dissolved  in  6  times  its  weicht  of  water,  and  the  solution  is  to  be  boiled 
for  an  hour,  along  with  one  pound  of  slaked  lime  for  every  pound  of  the  bicarbonate 
used.  The  whole  must  be  left  to  settle  without  contact  of  air.  The  supernataut  ley  is  to 
be  drawn  off  by  a  syphon,  and  evaporatetl  in  an  iron  or  silver  vessel  provided  with  a  small 
orifice  in  its  close  cover  for  the  escape  of  the  steam,  till  it  assumes,  as  above,  the  appear- 
ance of  oil,  or  till  it  be  nearly  redhot.  Let  the  fused  potassa  be  now  poured  out  upon  a 
bright  plate  of  iron,  cut  mto  pieces  as  soon  as  it  concretes,  and  put  up  immediately  in  a 
botlle  furnished  with  a  well-ground  stopper.  It  is  hydrate  of  potassa,  being  composed  of 
1  atom  of  potassa  48,  -|-  1  atom  of  water  9,  =  57. 

A  pure  carbonate  of  potassa  may  be  also  prepared  by  fusing  pure  nitre  in  an  earthen 
crucible,  and  projecting  charcoal  into  it  by  small  bits  at  a  time,  till  it  ceases  to  cause 
deflagration.  Or  a  mixture  of  10  parts  of  nitre  and  1  of  charcoal  may  be  deflagrated  in 
small  successive  portions  in  a  redhot  deep  crucible.  When  a  mixture  of  2  parts  of 
tartrate  of  potassa,  or  crystals  of  tartar,  and  1  of  nitre,  is  deflagrated,  pure  carbonate  of 
potassa  remams  mixed  with  charcoal,  which  by  lixiviation,  and  the  agency  of  quick- 
lime, will  afford  a  pure  hydrate.      Crystals  of  tartar  calcined  alone  yield  also  a  pure 

carbonate. 

Caustic  potassa,  as  I  have  said,  after  being  fused  in  a  silver  crucible  at  a  red  heat, 
retains  1  prime  equivalent  of  water.  Hence  its  composition  in  100  parts  is,  potassium 
70,  oxygen  14,  water  16.  Anhydrous  potassa,  or  the  oxyde  free  from  water,  can  be  ob- 
tained only  by  the  combustion  of  potassium  in  the  open  air.  It  is  composed  of  83|  of 
netal,  and  16f  of  oxygen.    Berzelius's  numbers  arc,  8305  and  16-95. 

Caustic  potassa  may  be  crystallized ;  but  in  general  it  occurs  as  a  white  brittle  sub- 
stance of  spec.  grav.  1*708,  which  melts  at  a  red  heat,  evaporates  at  a  white  heat,  de- 
liquesces into  a  liquid  in  the  air,  and  attracts  carbonic  acid;  is  soluble  in  water  and 
alcohol,  forms  soft  soaps  with  fat  oils,  and  soapy-looking  compounds  with  resins  and 
wax ;  dissolves  sulphur,  some  metallic  sulphurets,  as  those  of  antimony,  arsenic,  &.C., 
as  also  silica,  alumina,  and  certain  other  bases;  and  decomposes  animal  textures,  as 
hair,  wool,  silk,  horn,  skin,  &ic.  It  should  never  be  touched  with  the  tongue  or  the 
fingers. 

The  following  Table  exhibits  the  quantity  oC  Fused  Potassa  in  100  parts  oC  caustic  ley, 
at  the  respective  densities  : — 


Sf.  gr. 

Pot.  in  100. 

Sp.gr. 
1-46 

Pot.  in  100. 

I 

! 

Sp.  gr. 

Pot.  in  10(i 

Sp.  gr. 

Pot.  in  100. 

1 

.  Sp.  gr. 

Pot.mHiO 

1-58 

53-06 

42-31 

1-34 

32- 14 

1-22 

23-14 

1-10 

11-28 

1.56 

51-58 

1-44 

40-17 

1-32 

30-74 

1-20 

21-25 

1-08 

9-20 

1-54 

50-09 

1-42 

37-97 

1-30 

29-34 

1-18 

19-34 

1-06 

7-02 

1-52 

48-40 

1-40 

35-99 

1-28 

27-86 

1-16 

17-40 

104 

4-77 

1-50 

46-45 

1-38 

34-74 

1-26 

26-34 

1-14 

15-38 

1-02 

244 

1-48 

44-40 

1-36 

33-46 

1-24 

21-77 

1-12 

1330 

1-00 

0-00 

The  only  certain  way  of  determining  the  quantity  of  free  potassa  in  any  solid  or  liquid, 
is  from  the  quantity  of  a  dilute  acid  of  known  strength  which  it  can  saturate. 

The  hydrate  of  potassa,  or  its  ley,  often  contains  a  notable  quantity  of  carbonate,  the 
presence  of  which  may  be  detected  by  lime  water,  and  its  amount  be  ascertained  by  the 
loss  of  weight  which  it  suffers,  when  a  weighed  portion  of  the  lev  is  poured  into  a 
weighed  portion  of  dilute  sulphuric  acid  poised  in  the  scale  of  a  balance. 

There  are  two  other  oxydes  of  potassium ;  the  suboxyde,  which  consists,  according  to 
Berzelius,  of  90-74  of  metal,  and  9-26  oxygen  ;  and  the  hyperoxyde,  an  oranee-yellow 
substance,  which  gives  oft' oxygen  in  the  act  of  dissolving  in  water,  and  becomes  potassa. 
It  consists  of  62  of  metal,  and  38  of  oxygen. 

Carbonate  of  potassa  is  composed  of  48  parts  of  base,  and  22  of  acid,  according  to  most 
British  authorities;  or,  in  100  parts,  of  68-57  and  31-43;  but  according  to  Berzelius,  of 
68-09  and  31-91. 

Carbonate  of  potassa,  as  it  exists  associated  with  carbon  in  calcined  tartar,  passes  very 
readily  into  the  Bicarbonate^  on  being  moistened  with  water,  and  having  a  current  of  car- 
bonic acid  gas  passed  through  it.    The  absorption  takes  place  so  rapidly,  that  the  mass 


becomes  hot,  and  therefore  ought  to  be  surrounded  with  cold  water.  Tlie  salt  should 
then  be  dissolved  in  the  smallest  quantity  of  water  at  120°  Fahr.,  filtered  and 
crvstAiIizGQ 

Pearl  and  Pot  Ashes  imported,  in  1850,  184,043  cwts.,  in  1851,  199,911  cwts. 

POTASH,  BICHROMATE  OF.  Mr.  Charles  Kober  obtained  in  1840  a  patent  for 
the  use  of  bichromate  of  potash  as  a  substitute  for  copperas,  alum,  and  other  mordant* 
for  uniting  the  colouring  ingredients  in  dyeing  with  the  wool,  in  consequence  of  mutual 
affinity;  the  ordinary  dyeing  ingredients'beiug  employed  in  conjunction  with  the  bi- 
chromate ;  he  sometimes  adds  2  lbs.  of  argol  for  100  lbs.  of  wool.  The  chief  use  of  the 
bichromate  seems  to  be  for  brightening  and  fixing  the  common  dyes  and  mordants. 

POTASH  AND  SODA,  CAUSTIC.  Mix  a  solution  of  1  part  of  the  dry  carbonate 
salt  with  1  part  freshly  prepared  dry  hydrate  of  lime,  and  allowing  it  to  stand  in  a 
closed  vessel  for  24  hoiii-s  at  a  temperature  of  68»  to  78«»  Fahr.,  frequently  shaking  it 
The  potash  salt  should  be  dissolved  in  12  to  15,  the  soda  salt  in  7  to  15  parts  of  water; 
the  carbonate  of  lime  separates  in  a  granulated  state,  and  the  clear  caustic  lye  may  be 
decanted.  A  weaker  lye  may  be  obtained  from  the  residue  by  fresh  treatment  with  water. 

POTASH,  CHLORATE  OF.  Chlorate  of  potash  may  be  economically  made  bj 
mixing  5^  atoms  of  quick  lime  with  1  of  caustic  potash,  and  passing  a  current  of  chlorine 
gas  through  the  mixture,  in  a  thin  pasty  state,  with  water  at  a  boiling  heat  Under 
these  conditions,  chloride  of  calcium  and  chlorate  of  potash  are  produced,  thus,  by  the 
use  of  lime,  the  enormous  loss  of  potash,  which  in  the  ordinary  process  is  converted  into 
chloride,  is  avoided ;  since,  instead  of  producing  43  grs.  for  100  grs.  of  potasli,  220  grs. 
may  be  obtained,  Avhich  approaches  to  the  theoretical  number  2G0. 

A  fact  which  demonstrates  in  a  remarkable  manner  how  grAitly  the  chemical  af- 
finity of  chlorine  for  oxygen  is  increased  by  heat,  is,  that  a  mere  trace  of  chlorate  is 
produced  when  chlorine  is  passed  into  a  mixture  of  lime  and  caustic  potash  at  the  ordi- 
nary temperature. 

Another  point  which  results  from  these  experiments  is,  the  influence  of  the  degree  of 
concentration  of  the  liquids.  If,  for  instance,  a  solution  of  caustic  potash,  of  1  -040  spec 
gr.  at  82°,  and  containing  34  grs.  of  potash  in  1000  gre.  of  liquid,  is  mixed  with  431  grs. 
of  lime,  or  6  equivs.,  only  131  grs.  of  chlorate  are  obtained.  Another  mixture,  made 
with  1000  grs.  of  liquid  containing  58-75  of  potash  and  6  equivs.  of  lime,  gave  168  grs. 
of  chlorate  of  potash.  Lastly,  by  taking  a  solution  of  caustic  potash  of  11 10  sp.  gr., 
and  containing  102-33  of  potash  for  100  grs.  of  fluid,  and  adding  to  it  6  equivs.  of 
caustic  lime,  heating  the  whole  gradually  to  122°,  then  passing  a  rapid  current  of 
chlorine  to  saturation  (which  raises  the  temperature  to  about  194°),  filtering,  evaporat- 
ing to  dryness,  redissolving  in  boiling  water,  and  allowing  the  whole  to  cool,  220  gra. 
of  pure  chlorate  of  potash  may  be  obtained.  This  process  has  been  applied  on  a  large 
•cale,  and  has  perfectly  succeeded. 

POTASH,  PRL'SSIATE  OF.     See  Prussian  Blue. 

POTASSIUM  (Eng.  and  Fr. ;  Kalium,  Germ.)  is  a  metal  deeply  interesting,  not  only 
from  its  own  marvellous  properties,  but  from  its  having  been  the  first  link  in  the  chain 
of  discovery  which  conducted  Sir  H.  Davy  through  many  of  the  formerly  mysterious  and 
untrodden  labyrinths  of  chemistry. 

The  easiest  and  best  mode  of  obtaining  this  elementary  substance,  is  that  contrived  by 
Brunner,  which  I  have  often  practised  upon  a  considerable  scale.  Into  the  orifice  of  one 
of  the  iron  bottles,  as  A,y/g.  889,  in  which  mercury  is  imported,  adapt,  by  screwing,  a  piece 
of  gun-barrel  lube,  9  inches  long ;  having  brazed  into  its  side,  about  3  inches  from  its  outer 
end,  a  similar  piece  of  iron  tube.  Fill  this  retort  two  thirds  with  a  mixture  of  10  parts 
of  cream  of  tartar,  previously  calcined  in  a  covered  crucible,  and  1  of  charcoal,  both  in 
powder ;  and  lay  it  horizontally  in  an  air-furnace,  so  that  while  the  screw  orifice  is  at 
Uic  inside  waK,  ihe  extremity  of  the  straight  or  nozzle  tube  may  project  a  few  inches 
beyond  the  brickwork,  and  the  tube  brazed  into  it  at  right  angles  may  descend  pretty 
close  to  the  outside  wall,  so  as  to  dip  its  lower  end  a  quarter  of  an  inch  beneath  the  surface 
of  some  rectified  naptha  contained  in  a  copper  bottle  surrounded  by  ice-cold  water. 
By  bringing  tlie  condenser-vessel  so  near  the  furnace,  the  tubes  along  which  the  potas- 
sium vapor  requires  to  pass,  run  less  risk  of  getting  obstructed.  The  horizontal  straight 
end  of  the  nozzle  tube  should  be  shut  by  screwing  a  stopcock  air-tight  into  it.  Bjr 
opening  the  cock  momentarily,  and  thrusting  in  a  hot  wire,  this  tube  may  be  readily 
kept  free,  without  permitting  any  considerable  waste  of  potassium.  The  heat  should 
be  slowly  applied  at  first,  but  eventually  urged  to  whiteness,  and  continued  as  lone 
as  potass  jreted  hydrogen  continues  to  be  disengaged.  The  retort,  and  the  part  of 
the  nozzh;  lube  exposed  to  the  fire,  should  be  covered  with  a  good  refractory  lute,  as 
described  under  the  article  Phosphorus.  The  joints  must  be  perfectly  air-tight ;  and 
the  vessel  freed  from  every  trace  of  mercury,  by  ignition,  before  it  is  charged  with  the 

tartar-ash.  .  i     l      •.. 

Tartar  skilfully  treated  in  this  way  will  afford  3  per  cent,  of  potassium  j  and  when  it 


I 


■1 


,M 


460 


POTASSIUM. 


it  is  observed  to  send  forth  green  fumes,  it  has  commenced  the  production  of  the 

m^y  be  enTployed       '  ^^"^^^^^^^^^  ^^^^^  ^^^^^'^^^^  the  following  ?orm  ofapplj^ 

A,>>  1146.,  represents  the  iron  bottle,  charged  with  the  incinerated  tartar-  and  r 

S'the"bot"ltanT?hrh  t  ^'^f  1  f^f'  «'^'^^  '^'^^  *^^  placerbetwl'^tt  bo^^^^^^ 
01  tHe  bottle  and  the  back  wall  of  the  furnace,  to  keep  the  apparatus  steadv  during 
the  operation  Whenever  the  moisture  is  expelled,  and  the  rJ^Trfai^tlv  Sed  thf 
tube  0  should  be  screwed  into  the  mouth  of^the  bottle,  through  a  sS  ifoTelit  for 


H 


1146 


<z-       e^ 


■^t 


i 


n€ZED 


^ 


rzi 


J 


5 


5 


i5^ 


rh 


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j6 


Ti 


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1147 


iS 


i3 


in 


S3 


this  purpose  in  the  side  of  the  furaace.  That  tube  should  be  no  longer,  and  the  front 
wall  of  the  furnace  no  thicker,  than  what  is  absolutely  necessary.  As  soon  as  the 
reduction  is  indicated  by  the  emission  of  green  vapoui-s,  the  receiver  must  be  adapted. 
0,0,  D,E,  shown  in  a  large  scale  in  Ji^.  1147.  ^ 

This  is  a  condenser,  in  two  pieces,  made  of  thin  sheet  copper;  n^he  upper  part  is  a 
rectangular  box,  open  at  bottom,  about  10  inches  high,  by  5  or  6  long  and  2  wide ;  near 
to  the  side  a,  it  is  divided  mside  into  two  equal  compartments,  up  to  two-thirds  of  its 
height,  by  a  partition,  b,  b,  in  order  to  make  the  vapours  that  issue  from  c  pursue  a 
downward  and  circuitous  path.  In  each  of  its  narrow  sides,  near  the  top,  a  short  tube 
18  soldered,  bX  d  and  a;  the  former  being  fitted  air-tight  into  the  end  of  the  nozzle  of 
ine  retort,  while  the  latter  is  closed  with  a  cork  traversed  by  a  stiff  iron  probe  e  which 
passes  through  a  small  hole  in  tlie  partition  6,  6,  under  c,  and  is  employed  to  keep  the 
tube  o  clear,  by  its  drill  shaped  steel  point  In  one  of  the  broad  sides  of  the  box  i, 
near  the  top,  a  bit  of  pipe  is  soldered  on  at  c,  for  receiving  the  end  of  a  bent  glass  tibe 
ot  satety,  which  dips  its  other  and  lexer  end  into  a  glass  containing  naphtha  f  the 
bottom  copper  box,  with  naphtha,  which  receives  pretty  closely  the  upper  case  d  la  to 
be  immei'sed  in  a  cistern  of  cold  water,  containing  some  lumps  of  ice.  *   * 

The  cliemical  action  by  which  potassa  is  reduced  in  this  process  seems  to  be  some- 
what  complicated,  and  has  not  been  thoroughly  explained.  A  veiy  small  i)roportion 
of  pure  potassium  is  obtained ;  a  great  deal  of  it  is  converted  into  a  black  infusible 
mass,  Avhich  passes  over  with  the  metal,  and  is  very  apt  to  block  up  the  tube  Should 
this  resist  clearing  out  with  the  probe,  the  fire  must  be  immediately  withdrawn  from 
the  furnace,  otherwise  the  apparatus  will  probably  bui-st  or  blow  ua  Care  must  be 
taken  to  prevent  any  moisture  getting  into  the  nozzle,  for  it  would  probably  produce 
a  violent  detonation.  ^  ^ 

When  the  operation  has  proceeded  regularlj^,  accompanied  to  the  end  with  a  con- 
stant evolution  of  gas,  the  retort  becomes  nearly  empty,  or  contains  merely  a  little 
charcoal,  or  carbonate  of  potassa,  and  the  potassium  collects  in  the  naphtha  at  the 
bottom  of  the  receiver  e,  in  the  form  of  globules  or  rounded  lumps,  of  greater  or 
less  size,  and  of  a  leaden  hue.  But  the  greater  pai-t  of  the  metal  escapes  with  the 
gas,  m  a  state  of  combination  not  well  understood.  This  gaseous  compound  burns 
with  a  white  or  reddish-white  flame,  and  deposits  potassa.  Several  ounces  of  potas- 
sium niay  be  produced  in  this  way  at  one  operation ;  but,  as  thus  obtained,  it  always 
contains  some  combined  charcoal,  whisAi  must  be  separated  by  distillin  '  " 
retort,  having  its  beak  plunged  in  naptha. 


g  It  m  an  iron 


POTATO  SUGAR. 


461 


Pure  potassium,  as  procured  in  Sir  H.  Davy's  original  method,  by  acting  upon  fused 
potassa  under  a  film  of  naphtha,  with  the  negative  wire  of  a  powerful  voltaic  battery, 
IS  very  like  quicksilver.  It  is  semi-fluid  at  60°  Fahr.,  nearly  liquid  at  92°,  and 
entirely  so  at  120°.  At  50°  it  is  malleable,  and  has  the  lustre  of  polished  silver;  at 
32^  it  is  brittle,  with  a  crystalline  fracture ;  and  at  a  heat  approaching  to  redness,  it 
begins  to  boil,  is  volatilized,  and  converted  into  a  green-coloured  gas,  which  condenses 
into  globules  upon  the  surface  of  a  cold  body.  Its  specific  gravity  in  the  purest  state 
is  0'865  at  G0°.  When  heated  in  the  air,  it  takes  fire,  and  burns  very  vividl}'.  It  has 
a  stronger  affinity  for  oxygen  than  any  other  known  substance ;  and  is  hence  very  diffi- 
cult to  preserve  in  the  metallic  state.  At  a  high  temperature  it  reduces  almost  every 
oxygenated  body.  When  thrown  upon  water,  it  kindles,  and  moves  about  %iolently 
upon  the  surface,  burning  with  a  red  flame,  till  it  be  consumed;  that  is  to  say, 
converted  into  potassa.  When  thrown  upon  a  cake  of  ice,  it  likewise  kindles,  and  burns 
a  hole  in  it.  If  a  globule  of  it  be  laid  upon  wet  turmeric  paper,  it  takes  fire,  and  runs 
about,  marking  its  desultory  parts  with  red  lines.  The  flame  observed  in  these  cases 
is  owing  chiefly  to  hydrogen,  for  it  is  at  the  expense  of  the  water  that  the  potassium 
burns. 

Potassa,  even  in  a  pretty  dilute  solution,  produces  a  precipitate  with  muriate  of 
platinum,  a  phenomenon  which  distinguishes  it  from  soda.  It  forms,  moreover,  with 
sulphuric  and  acetic  acids,  salts  which  crystallize  very  differently  from  the  sulphates 
and  acetates  of  soda. 

PoTAssiuai,  Cyanurkt  of  {Preparation  of).  Introduce  into  a  retort  a  mixture  of  two 
parts  of  ferro-cyanuret  of  potash,  and  l|^  parts  of  sulphuric  acid,  previously  diluted 
with  1^  parts  of  water,  and  allowed  to  cooL  Place  in  the  receiver  a  colourless  solution 
of  one  part  of  pure  hydrate  of  potash  in  3  or  4  parts  of  alcohol  containing  90  per 
cent,  of  real  alcohoL  The  receiver  or  the  retort  should  be  tubulated  and  furnished 
with  a  safety  tube.  The  receiver  must  be  cooled  as  much  as  possible,  and  the  distilla- 
tion conducted  very  slowly,  in  consequence  of  the  great  heat  developed  in  the  receiver 
during  the  condensation.  As  soon  as  the  force  of  ebullition  in  the  retort  has  subsided, 
the  operation  should  be  stopped,  for  it  is  a  sign  that  the  greater  part  of  the  prussic  acid 
is  disengaged ;  and  if  the  distillation  be  continued,  water  will  be  carried  over  and  mixed 
with  the  liquor  in  the  receiver.  This  liquor  is  transformed  into  a  thick  mixture  of  pre- 
cipitated cyanuret  of  potassium,  and  the  alcoholic  solution  of  the  undecomposed  potash. 
The  precipitate  is  to  be  collected  on  a  filter,  freed  from  the  mother  water,  and  washed 
with  alcohol,  then  pressed  and  dried  on  the  same  filter.  Two  ounces  of  ferro-cyanuret 
of  potash,  treated  in  this  manner,  will  produce  6  grammes  of  cyanuret  of  potassium. 
This  proportion  is  a  little  under  the  calculation,  the  reason  being  that  the  prussic 
acid  is  not  entirely  disengaged  by  the  distillation,  and  that  the  alcohol  dissolves  about 
1  per  cent,  of  its  weight  of  cyanuret  of  potassium.  On  the  other  hand,  it  is  difficult 
to  obtain  this  combination  equally  pure  by  any  other  method.  The  alcohol  may  be 
regained  by  distilling  it  from  some  metallic  salt^  such  as  calcined  green  vitriol. 

POTATO  (Fomme  de  terre,  Fr. ;  JCartoel,  Germ.) ;  is  the  well-known  root  of  the 
Solarium  tuberosum. 

Many  methods  have  at  different  times  been  tried  for  preserving  potatoes  in  an  un- 
changeable state,  and  always  ready  to  be  dressed  into  a  wholesome  and  nutritious  dish, 
but  none  with  such  success  as  the  plan  of  Mr.  Downes  Edwards,  for  which  he  obtained 
a  patent  in  August,  1840.  The  potatoes,  being  first  clean  washed,  are  boiled  in  water 
or  steamed,  till  their  skins  begin  to  crack,  then  peeled,  freed  from  their  specks  and  eyes, 
and  placed  in  an  iron  cylinder,  tinned  inside,  and  perforated  with  many  holes  one-eighth 
of  an  inch  in  diameter.  The  potatoes  are  forced  through  these  by  the  pressure  of  a  piston. 
The  pulp  is  finally  dried  on  well-tinned  plates  of  copper,  moderately  heated  by  steam, 
into  a  granular  meal.  When  this  is  mixed  into  a  pulp  with  hot  water,  and  seasoned 
with  milk,  <fec.,  it  forms  a  very  agreeable  food — like  fresh  mashed  potatoes.  [See  p.  462.] 

POTATO  SUGAR.  Several  years  ago  a  sample  of  sweet  mucilaginous  liquid  was 
sent  to  me  for  analysis  by  the  Hon.  the  Commissioners  of  Customs.  It  was  part  of  a 
quantity  imported  m  casks  at  Hull  from  Rotterdam ;  it  was  called  by  the  importers 
vegetable  Juice.  I  found  it  to  be  imperfectly  saccharified  starch  or  fecula ;  and  on  my 
reporting  it  as  such,  it  was  admitted  at  a  moderate  rate  of  duty.  Some  months  after, 
I  received  a  sample  of  a  similar  liquid  from  the  importer  at  Hull,  with  a  request  that  I 
would  examine  it  chemically.  He  informed  me,  that  an  importation  just  made  by  him 
of  thirty  casks  of  it  had  been  detained  by  orders  of  the  Excise  till  the  sugar  duty  of 
twenty -five  shillings  per  cwt,  of  solid  matter  it  contained,  was  paid  upon  it  It  was 
of  specific  gravity  1-362,  and  contained  80  per  cent  of  ill-saccharified  fecula. 

In  the  interval  between  the  first  importation  and  the  second,  an  Act  of  Parliament  had 
been  obtained  for  placing  every  kind  of  sugar,  from  whatever  material  it  was  formed, 
under  the  provisions  of  the  beet-root  sugar  bill.  As  the  saccharometer  tables,  sub- 
servient to  the  levying  of  the  Excise  duties  under  this  Act^  were  constructed  by  me  at 


I  • 


462 


I  ;i 


■i¥^      i 


POTATO  SUGAR. 


The  following  Table  exhibits  several  good  analyses  of  the  potato; 


Sort. 


Red  potatoes  - 
Id.  germinated 
Potato  sprouts 
Kidney  potatoes 
Large  red  do.  - 
Sweet        do.  - 

Potato  of  Peru 
•  .  England  - 

Onion  potato  - 
.  .      Voigtland 
.  .  cultivated  in  the 
environs  of  Paris 


Fibri 


ne. 


7-0 
6-8 
2-8 
8-8 
G-0 
8-2 

6-2 

6-8 
8-4 
7-1 
6-79 


Starch. 


15-0 
15-2 
0-4 
9-1 
12-9 
151 

16-0 
12-9 
18-7 
15-4 
13-3 


Veg. 
album. 


1-4 
1-3 
0-4 
0-8 
0-7 
0-8 

1-9 
11 
0-9 
1-2 
0-92 


Gum. 


41 
3-7 
3-3 


Acids  and 
Salts. 


51 


Water.  Analvst. 


75-0 
73-0 
93  0 
81-3 

78-0 
74-3 


Jbiiiiiiof. 


3-3 


1-9 

76-0 

1-7 

77-5 

1-7 

70-3 

2-0 

74-3 

1     1-4 

73-12 

Lampad. 


Henry. 


the  request  of  the  president  of  the  board,  I  was  aware  that  fifty  per  cent,  of  the  syrnp 
ot  the  beet  root  was  deducted  as  a  waste  product,  because  beet  root  molasses  is  too 
crude  an  article  for  the  use  of  man.  Well  saccharified  starch  paste,  however,  consti- 
tutes a  syrup,  poor  indeed  m  sweetness  when  compared  with  cane  svrup  or  that  of  the 
beet  root;  but  then  it  does  not  spontaneously  blacken  into  molass^es  by  evaporation, 
as  solutions  of  ordinary  su^ar  never  fail  to  do  when  they  are  concentrated  even  with 
peat  care.  Hence  the  residuary  syrups  of  saccharified  fecula  may  be  all  worked  up 
into  a  tolerably  white  concrete  mass,  which,  being  pulverized,  Is  used  by  greedy 
grocers  to  mix  with  their  dark  brown  bastard  sugars  tS  improve  their  colour  ^ 

It  18  not  many  yeare  that  sugar  has  been  in  this  country  manufactured  from  potato 
starch  to  any  extent,  though  it  has  been  long  an  object  of  commercial  enterpHse  in 
France,  Belgium,  and  Holland,  where  the  large  coarse  potatoes  are  used  for  this  pur- 
pose. The  raw  material  must  be  very  cheap,  as  well  as  the  labour,  for  potato  flour 
or  starch,  for  conversion  into  sugar,  has  been  imported  from  the  continent  into  this 
country  m  large  quantities,  and  sold  in  London  at  the  low  price  of  sixteen  shillings 

The  process  usually  followed  by  the  potato  sugar  makers  Is  to  mix  100  gallons  of 
boiling  water  with  every  1 12  lbs.  of  the  fecula,  and  2  lbs.  of  the  strongest  sulphuric  acid. 
This  mixture  is  boiled  about  12  hours  in  a  large  vat,  made  of  white  deal,  having  lead 
pipes  laid  along  its  bottom  which  are  connected  with  a  high-pressure  steam  boiler. 
After  being  thus  saccharified,  the  acid  liquid  is  neutralized  with  chalk,  filtered,  and  then 
evaporated  to  the  density  of  about  1300,  at  the  boiling  temperature,  or  exactly  1-342. 
when  cooled  to  60°.     When  syrup  of  this  density  is  left  in  repose  for  some  day^  it  con- 

TavTfv  1  If  wi  .'iP'*^"^"'  *">  ^"^  ^^™«  ^°  apparently  dry  solid,  of  specific 
gravity  1-39.  When  this  is  exposed  to  the  heat  of  220«  it  fuses  into  a  liquid  nearly  as 
thin  as  water;  on  cooling  to  150°  it  takes  the  consistence  of  honey,  and  at  100°  F^hr. 
L^^;  f  f  f  \''''\vr'l^-  ^\  ""'*  ^^  ^^^^  «  considerable  time  at  reii  before  it  recovers 
Its  pn  tine  state.     When  heated  to  270°  it  boils  briskly,  gives  off  one-tenth  of  its  weight 

liL  Wll  ^^'^^^.f  tr^"  '^^^*':^  ^°^^  *  ^"e^^  y^"«^'  brittle,  but  deliquescent  mass, 
«a  L  1  S  ^"^-^/^  V  w!  P'-^^  ^^  concentrated  to  a  much  greater  density  than  1  34^ 
as  to  1  -362  or  if  it  be  left  faintly  acidulous,  in  either  case  it  lill  not  granulate,  but  wU 

IIT  A  ^/l  t  ''■l^^'^  ™3^^^'  ^^  b^<^«"«  »  concrete  mass,  which  may  indeed  be  pul- 
verized, though  It  IS  so  deliquescent  as  to  be  unfit  for  the  adulteratioi  of  raw  sugar. 

r.lt  ii,l  •^'"''^  '"  '"^  ^^'  predicament,  and  is  therefore,  in  my  opinion,  hardly  Ime- 
?pin.].Un^  "r  '''^^'  ^n"^'  ^'  '^  "^°^«*  ^y  «°y  °^^«°s  t«  ^«rie<f  up  into  even  the 
to  280°  t^t  U  .r^' •  ^««d  Muscovado  sugar  from  Jamaica  fuses  only  when  heated 
^rlnn  n^  f^  I  immediately  dark-brown  from  the  disengagement  of  some  of  its 
^JZl  il^f  .t«"™Pcrature,  and  becomes,  in  fact,  the  substance  called  caramel  by  the 
^Irln.  «tnt  '  "''i1  for  colouring  brandies,  white  wines,  and  liqueurs.  Thus  starch 
SLf  r/,"f!^r  ^«  ^'^",  ^;.f '"g"'«l^ed  from  cane  sugar,  by  its  fusibility  at  a  moderate 

fifth^«  nf  fhof  ^?  l"*"^'^'*^  ^*  ^  ^'^^^y  ^^g^  ^'^^  Its  sweetening  power  is  only  two- 
fifths  of  that  of  ordinary  sugar.  A  good  criterion  of  incompletely  foimed  grape  sugar 
IS  Its  resisting  the  action  of  sulphuric  acid,  while  perfectly  saccharified  starch  or  cfne 
sugar  IS  readily  decomposed  by  it.  If  to  a  strong  solutioi  of  imperfectly  saccharified 
grape  sugar  nearly  boiling  hot,  one  drop  of  sulphuric  acid  be  let  fall,  no  perceptible 
change  will  ensue ;  but  if  the  acid  be  dropped  into  solutions  of  either  of  the  other  two 
sugars  black  carbonaceous  particles  will  make  their  appearance.  The  article  which  was 
lately  detained  by  the  Excise  for  the  high  duties  at  Hull  is  not  affected  by  sulphuric 


POTATO  SUGAR. 


46d 


acid,  as  are  solutions  of  cane  sugar,  and  of  the  well  made  potato  sugar  of  London ;  and 
for  this  reason  I  gave  my  opinion  in  favour  of  admitting  the  so-called  vegetable  juice 
at  a  moderate  rate  of  duty. 

I  subjected  the  solid  matter,  obtained  by  evaporating  the  Hull  juice  to  ultimate 
analysis,  by  peroxide  of  copper,  in  a  combustion  tube,  with  all  the  requisite  precautions; 
and  obtained  in  one  experiment  37  i)er  cent  of  carbon,  and  in  another  38  per  cent, 
when  the  substance  had  been  dried  in  an  air-bath  heated  to  275°.  The  difference  to 
100  is  hydrogen  and  oxj^gen  in  the  proportion  to  form  water.  Now,  this  is  the  consti- 
tution of  grape  sugar.  Cane  sugar  contains  about  6  per  cent  more  carbon,  whereby 
it  readily  evolves  this  black  element  by  the  action  of  heat  or  sulphuric  acid. 

An  ingenious  memoir,  by  Mr.  Trommer,  upon  the  distinguishing  criteria  of  gum, 
dextrine,  grape  sugar,  and  cane  sugar,  has  been  published  in  the  3rd  volume  of  the 
Annalen  der  Chemie  und  Pharmacie.  I  have  repeated  his  experiments,  and  find  them  to 
give  correct  results,  when  modified  in  a  certain  way.  His  general  plan  is  to  expose  the 
hydrate  of  copper  to  tlie  actions  of  solutions  of  the  above  mentioned  vegetable  products. 
He  first  renders  the  solution  alkaline,  then  adds  solution  of  sulphate  of  copper  to  it,  and 
either  heats  the  mixture,  or  leaves  it  for  some  time  in  the  cold.  By  pursuing  his  direc- 
tions, I  encountered  contradictory  results ;  but  by  the  following  method,  I  have  secured 
uniform  success  in  applying  the  criteria,  and  have  even  arrived  at  a  method  of  deter- 
mining, by  a  direct  test  the  quantity  of  sugar  in  diabetic  urine. 

I  dissolve  a  weighed  portion  of  sulphate  of  copper  in  a  measured  quantity  of  water, 
and  make  the  solution  j^am%  alkaline,  as  tested  with  turmeric  paper,  not  litmus,  by  the 
addition  of  potash  lye  in  the  cold,  for  if  the  mixture  be  hot,  a  portion  of  the  disengaged 
green  hydrate  of  copper  is  converted  into  black  oxide.  This  mixture  being  always 
agitated  before  applying  it  forms  the  test  liquor.  If  a  few  drops  of  it  be  introduced 
into  a  solution  of  gum,  no  change  ensues  on  the  hydrate  of  copper,  even  at  a  boiling 
heat,  which  shows  that  a  gummate  of  copper  is  formed  which  resists  decomposition ;  but 
the  cupreous  mixture  without  the  gum,  is  rapidly  blackened  at  a  boiling  temperature. 
I  do  not  find  that  the  gummate  is  redissolved  by  an  excess  of  water,  as  Trommer  affirms. 
Starch  and  tragacanth  comport  like  gum,  in  which  respect  I  agree  with  Trommer ; 
starch,  however,  possesses  already  a  perfect  criterion  in  iodine  water.  Mr.  Trommer 
says,  that  solution  of  dextrine  affords  a  deep  blue  coloured  liquid,  without  a  trace  of 
precipitate ;  and  that  when  his  mixture  is  heated  to  85°  C.  it  deposits  red  grains  of  pro- 
toxide of  copper,  soluble  in  muriatic  acid.  I  think  these  phenomena  are  dependent,  in 
some  measure,  upon  the  degree  of  alkaline  excess  in  the  mixture.  I  find  tliat  solution 
of  dextrine  treated  in  my  way  hardly  changes  in  the  cold,  but  when  heated  slightly 
becomes  green,  and  by  brisk  boiling  an  olive  tint  is  produced;  it  thus  betrays  its  ten- 
dency of  transition  into  sugar.  Solution  of  cane  sugar,  similarly  treated,  undergoes  no 
change  in  the  cold  at  the  end  of  two  days;  and  even  very  little  change  of  colour,  even 
at  a  boiling  heat,  if  not  too  concentrated.  Cane  sugar,  treated  by  Trommer  in  his  way, 
becomes  of  a  deep  blue ;  it  can  be  boiled  with  potash  in  excess  without  any  separation 
of  orange  red  oxide  of  copper. 

Starch,  or  grape  sugar,  has  a  marvellous  power  of  reducing  the  green  hydrate  of  copper 
to  the  orange  oxide,  but  I  find  it  will  not  act  upon  the  piire  blue  hydrate  even  when 
recently  precipitated ;  it  needs  the  addition  in  this  case  also  of  a  small  portion  of 
alkali ;  but  ammonia  does  not  seem  to  serve  the  purpose,  for  on  using  the  ammonio- 
sulphate  of  copper  in  solution,  I  obtained  unsatisfactory  results  with  the  above  vegetable 
products.  The  black  oxide  of  copper  is  not  affected  by  being  boiled  in  a  solution  of 
starch  sugar.  "  If  solution  of  grape  sugar,"  says  Trommer,  "  and  potash  be  treated  with 
a  solution  of  sulphate  of  copper,  till  the  separated  hydrate  is  re-dissolved,  a  precipitate 
of  red  oxide  will  soon  take  place  at  common  temperature;  but  it  immediately  forms, 
if  the  mixture  is  heated.  A  liquid  containing  j^  of  grape  sugar,  even  * 
part,"  says  he,  "gives  a  perceptible  tinge  (orange)  if  the  light  is  let  fall  upon  it"  *°tS 
obtain  such  a  minute  result,  very  great  nicety  must  be  used  in  the  dose  of  alkali,  which 
I  have  found  it  extremely  difficult  to  hit  With  my  regulated  alkaline  mixture,  how- 
ever, I  never  fail  in  detecting  an  exceedingly  small  portion  of  starch  sugar,  even  when 
mixed  with  Muscovado  sugar;  and  thus  an  excellent  method  is  afforded  of  detecting 
the  frauds  of  the  grocers, 

I  find  that  manna  deoxidizes  the  green  hydrate  of  copper  slowly  when  heated  but 
not  nearly  to  the  same  extent  as  grape  sugar,  which  reduces  it  rapidly  to  the  orange 
oxide. 

If  an  excess  of  the  hydrate  of  copper  test  be  used,  there  will  be  a  deposit  of  green 
hydrate  at  the  bottom  of  the  vessel. 

To  apply  these  researches  to  the  sugar  of  diabetic  urine.  This  should  first  be  boiled 
briskly  to  decompose  the  urea  and  to  dissipate  its  elements  in  the  form  of  ammonia,  as 
well  as  to  concentrate  the  saccharine  matter,  whereby  the  test  becomes  more  efficacious. 
Then  add  to  the  boiling  urine,  in  a  few  drops  at  a  time,  a  cupreous  mixture  containing 


464 


POTTERY. 


POTTERY. 


465 


.  * 


I 


a  known  quantity  of  the  sulphate  of  copper,  till  the  mixture  assumes  a  greenish  tint  and 
continue  he  heat  till  the  colour  becomes  bright  orange.  Should  it  remain  green  it t^a 
proof  that  more  hydrate  of  copper  has  been  introduced  than  is  equivalent  to  the  deo^! 
dizing  power  of  the  starch  sugar.     I  have  found  that  one  grain  of  sulphate  of  Conner  in 

orange  protoxide  by  about  three  grains  of  potato  sugar;  or  more  exactly  thirty  narta 

the  sLr;  ir'^''^'''  "^^^i  ^'^'^ ''  ^v^^^^^^  *^>'^^^^^  «^  copper  praCtES 

iv!r.l  "°^"  T^P^y^^^^\of  100  parts  of  granular' Itarch  sugar.^  Tlius,  for 

Sif  Zbftrurine  "  ^  "''  "^^""^'^  ''''  ^^""^  "^  ^"^"^  ^^^  ^«  ««timated  to 

thj^«ll!,f  Vx^''\  r^^i  ^%"'^^  '"^  i^^  "^^''^  experiments,  but  it  is  not  so  good  as 
the  sulphate.     The  chloride  of  copper  does  not  answer. 

Specific  gravity  is  also  an  important  criterion  applied  to  sugar;  that  of  the  cane  and 
beet  root  is  1-577,  not  l-eOfiS  as  given  by  Berzelius  and  other!;  that  of  starch  sugar  in 
crystalline  tufts,  is  1-39,  or  perhaps  1-40,  as  it  varies  a  little  with  its  state  of  dryness. 
t.J.'^f  P'T  ^  ""^.^ •  ^'^"^^^"s  seventy  per  cent  of  sugar ;  at  the  same  density 
2  9L0  /pT  ^  '"^f  ,^«°^^;««  seventy-five  and  a  half  per  cent  of  concrete  matter,  drieH 
at  250  (Fahr.),  and,  therefore,  freed  from  the  ten  per  cent  of  water  which  it  contains 
in  the  granular  state.  Thus  another  distinction  is  obtained  between  the  two  sugars  in 
the  relative  densities  of  their  solutions,  at  like  saccharine  contents  per  cent 

POTTERY,  PORCELAIN.  (Eng.  and  Fr. ;  Steingut,  Parzellan,  Germ.)  The 
French,  who  are  fond  of  giving  far-fetched  names  to  the  most  ordinary  thin?s,  have 
dignified  the  art  of  pottery  with  the  title  of  ceramique,  from  the  Greek  noun  KepaL  an 
earthen  pot,  compounded  of  two  words  which  signify,  in  that  lansjuape,  burned  clay.  '  In 
relerence  to  chemical  constitution,  there  are  only  two  genera  of  baked  stoneware  The 
first  consists  of  a  fusible  earthy  mixture,  along  with  an  infusible,  which  when  combined 
are  susceptible  of  becoming  semi-vitrified  and  translucent  in  the  kiln.  This  constitutes 
porcelain  or  china-ware;  which  is  either  hard  and  genuine,  or  tender  and  spuriou«! 
according  to  the  quality  and  quantity  of  the  fusible  ingredient.  The  second  kind  con! 
sists  of  an  infusible  mixture  of  earths,  which  is  refractory  in  the  kiln,  and  continues 
opaque.  This  is  pottery,  properly  so  called;  but  it  comprehends  several  sub- 
species,  which  graduate  into  each  other  by  imperceptible  shades  of  difference.  To 
^?na   &c  earthenware,   stoneware,   flintware,  fayence,  delft  ware,   iron-stone 

The  earliest  attempts  to  make  a  compact  stoneware,  "with  a  painted  glaze,  seem  to 
have  originated  with  the  Arabians  in  Spain,  about  the  9th  century,  and  to  have  passed 
thence  into  Majorca,  in  which  island  they  were  carried  on  with  no  little  success.  In  the 
14th  century,  these  articles,  and  the  art  of  imitating  them,  were  highly  prized  by  the 
Italians,  under  the  name  of  Majolica,  and  ;w)rcc/arw,  from  the  Portuguese  word  for  a  cup. 
1  he  first  fabric  of  stoneware  possessed  by  them  was  erected  at  Fayenza,  in  the  ecclesias- 
tical state,  whence  the  French  term  faymce  is  derived.  The  body  of  the  ware  was  usu- 
ally  a  red  clay,  and  the  glaze  was  opaque,  being  formed  of  the  oxydes  of  lead  and  tin,  along 
with  potash  and  sand.  Bernhard  de  Pallissy,  about  the  middle  of  the  16th  century,  man- 
uiactured  the  first  while /ayencc,  at  Saintes,  in  France;  and  not  long  afterwards  tht 
Dutch  produced  a  similar  article,  of  substantial  make,  under  the  name  of  delftware,  and 
delft  /)orcc/«in,  but  destitute  of  those  graceful  forms  and  paintings  for  which  the  ware  of 
layenza  was  distinguished.  Common  fayence  may  be,  therefore,  regarded  as  a  strong, 
well-burned,  but  rather  coarse-grained  kind  of  stoneware. 

It  was  in  the  17th  century  that  a  small  work  for  making  earthenware  of  a  coarse 
description,  coated  with  a  common  lead  glaze,  was  formed  at  Burslem,  in  Staffordshire 
which  may  be  considered  as  the  germ  of  the  vast  potteries  now  established  in  that 
hThl;  J      °^\""f^<^^«ie  was  improved  about  the  year  1690,  by  two  Dutchmen,  the 
thr!i  K    ^  ^'^V'l^''  introduced  the  mode  of  glazing  ware  by  the  vapor  of  salt,  which  they 
threw  by  handfuls  at  a  certain  period  among  the  ignited  goods  in  the  kiln.     But  these 
were  rude,  unscientific,  and  desultory  efforts.     It  is  to  the  late  Josiah  Wedgewood,  Esq. 
that  this  country  and  the  world  at  large  are   mainly  indebted  for  the  ^eat  modem 
advancement  of  the  ceramic  art.     It  was  he  who  first  erected  magnificent  factories, 
where  every  resource  of  mechanical  and  ch-mical  science  was  made  to  co-operate  with 
the  arts  of  painting,  sculpture,  and  statuar/,  in  perfecting  this  valuable  department  of 
the  industry  of  nations.     So  sound  were  his  principles,  so  judicious  his  plans  of  procedure. 
Zi  ^rannnn''''^    r^  ^^^"  prosecuted  by  his  successors  in  Staffordshire,  that  a  popula- 
tion of  60,000  operatives  now  derives  a  comfortable  subsistence  within  a  district  formerly 
bleak  and  barren  of  8  miles  long  by  6  broad,  which  contains  150  kilns,  and  is  signifi- 
cantly called  the  Potteries.  '  "  o "" 

OF  THE  MATERIALS  OF  POTTERY  OR  PORCELAIN,  AND  THEIR  PREPARATION. 

1.  CZay.— The  best  clay  from  which  the  Staffordshire  ware  is  made,  comes  from 
Dorsetshire ;  and  a  second  quality  from  Devonshire ;  but  both  are  well  adapted  for 
working,  being  refractory  in  the  fire,  and  becoming  very  white  when  burnt.  The  clay 
•s  cleaned  as  much  as  possible  by  hand,  and  freed  from  loosely  adhering  stones  at  the 


pits  where  it  is   lug.    In  the  factory  mounted  by  Mr.  Wedgewood,  which  may  be  re 
garded  as  a  type  )f  excellence,  the  clay  is  cut  to  pieces,  and  then  kneaded  into  a  palp 
with  water,  by  engines ;  instead  of  being  broken  down  with  pickaxes,  and  worked  wilk 
water  by  hand-paddles,  in  a  square  pit  or  water-tank,  an  old  process,  called  bluu8:ing. 
The  clay  is  now  thrown  into  a  cast-iron  cylinder,  20  inches  wide,  and  4  feet  high,  or 
into  a  cone  2  feet  wide  at  top,  and  6  feet  deep,  in  whose  axis  an  upright  shaft  revolves, 
bearing  knives  as  radii  to  the  shaft.     The  knives  are  so  arranged,  that  their  flat  sides 
lie  in  the  plane  of  a  spiral  line ;  so  that  by  the  revolution  of  the  shaft,  they  not  only  cut 
through  everything  in  their  way,  but  constantly  press  the  soft  contents  of  the  cylinder 
or  cone  obliquely  downwards,  on  the  principle  of  a  screw.     Another  set  of  knives 
stands  out  motionless  at  right  angles  from  the  inner  surface  of  the  cylinder,  and  projects 
nearly  to  the  central  shaft,  having  their  edges  looking  opposite  to  the  line  of  motion  of 
the  revolving  blades.     Thus  the  two  sets  of  slicing  implements,  the  one  active,  and  the 
other  passive,  operate  like  shears  in  cutting  the  clay  into  small  pieces,  while  the  active 
blades,  by  their  spiral  form,  force  the  clay  in  its  comminuted  state  out  at  an  aperture  at 
the  bottom  of  the  cylinder  or  cone,  whence  it  is  conveyed  into  a  cylindrical  vat,  to  be 
worked  into  a  pap  with  water.    This  cylinder  is  tub-shaped,  being  about  4  limes  wider 
than  it  is  deep.     A  perpendicular  shaft  turns  also  in  the  axis  of  this  vat,  bearing  cross 
spokes  one  below  another,  of  which  the  vertical  set  on  each  side  is  connected  by  upright 
staves  ffiving  the  moveable  arms  the  appearance  of  two  or  four  opposite  square  paddJe- 
boards'  revolving  with  the  shaft.    This  wooden  framework,  or  large  blunger,  as  it  is  called, 
turns  round  amidst  the  water  and  clay  lumps,  so  as  to  beat  them  into  a  fine  pap,  from 
which  the  stony  and  coarse  sandy  particles  separate,  and  subside  to  the  bottom.     When- 
ever the  pap  has  acquired  a  cream-consistenced  uniformity,  it  is  run  off  through  a  series 
of  wire,  lawn,  and  silk  sieves,  of  different  degrees  of  fineness,  which  are  kept  in  continual 
aeitation  backwards  and  forward  by  a  crank  mechanism;  and  thus  all  the  grosser  parts 
are  completely  separated,  and  hindered  from  entering  into  the  composition  of  the  ware. 
This  clay  liquor  is  set  aside  in  proper  cisterns,  and  diluted  with  water  to  a  standard 

density.  .  ,  ^  _ . 

2.  But  clay  alone  cannot  form  a  proper  material  for  stoneware,  on  account  of  its  great 
contractility  by  heat,  and  the  consequent  cracking  and  splitting  in  the  kiln  of  the 
vessels  made  of  it;  for  which  reason,  a  silicious  substance  incapable  of  contraction 
must  enter  into  the  body  of  pottery.  For  this  purpose,  ground  flints,  called  flint- 
powder  by  the  potters,  is  universally  preferred.  The  nodules  of  flint  extracted  from 
the  chalk  formation  are  washed,  heated  redhot  in  a  kiln,  like  that  for  burning  lime, 
and  thrown  in  this  state  into  water,  by  which  treatment  they  lose  their  translucency, 
and  become  exceeding  brittle.  They  are  then  reduced  to  a  coarse  powder  in  a  stamping- 
mill,  similar  to  that  for  stamping  ores;  see  Metallurgy.  The  pieces  of  flint  are  laid 
on  a  strong  grating,  and  pass  through  its  meshes  whenever  they  are  reduced  by  the 
stamps  to  ascertain  state  of  comminution.  This  granular  matter  is  now  transferred  to  the 
proper  flint-mill,  which  consists  of  a  strong  cylindrical  wooden  tub,  bottomed  with  flat 
pieces  of  massive  chertf  or  hornstone,  over  which  are  laid  large  flat  blocks  of  similar  chert, 
that  are  moved  round  over  the  others  by  strong  iron  or  wooden  arms  projecting  from  an 
upright  shaft  made  to  revolve  in  the  axis  of  the  mill-tub.  Sometimes  the  active  blocks 
are  fixed  to  these  cross  arms,  and  thus  carried  round  over  the  passive  blocks  at  the  bot- 
tom. See  infrhf  under  Porcelain,  figures  of  the  flint  and  feldspar  mill.  Into  this  cyl- 
indrical vessel  a  small  stream  of  water  constantly  trickles,  which  facilitates  the  grinding 
motion  and  action  of  the  stones,  and  works  the  flint  powder  and  water  into  a  species  of 
pap.  Near  the  surface  of  the  water  there  is  a  plug-hole  in  the  side  of  the  tub,  by  which 
the  creamy-looking  flint  liquor  is  run  off  from  time  to  time,  to  be  passed  through  lawn  or 
silk  sieves,  similar  to  tn:?e  used  for  the  clay  liquor;  while  the  particles  that  remain  oa 
the  sieves  are  returned  into  the  mill.  This  pap  is  also  reduced  to  a  standard  density  by 
dilution  with  water ;  whence  the  weight  of  dry  silicious  earth  present,  may  be  deduced 
from  the  measure  of  the  liquor. 

The  standard  clay  and  flint  liquors  are  now  mixed  together,  m  such  proportion  by 
measure,  that  the  flint  powder  may  bear  to  the  dry  clay  the  ratio  of  one  to  five,  or  occa- 
sionally one  to  six,  according  to  the  richness  or  plasticity  of  the  clay ;  and  the  liquors  are 
intimately  incorporated  in  a  revolving  churn,  similar  to  that  employed  for  making  the  clay- 
pap.  This  mixture  is  next  freed  from  its  excess  of  water,  by  evaporation  in  oblong  stone 
troughs,  called  slip-kilns^  bottomed  with  fire-tiles,  under  which  a  furnace  flue  runs.  The 
breadth  of  this  evaporating  trough  varies  from  2  to  6  feet ;  its  length  from  20  to  50 ;  and 
its  depth  from  8  to  12  inches,  or  more. 

By  the  dissipation  of  the  water,  and  careful  agitation  of  the  pap,  a  uniform  doughy 
mass  is  obtained;  which,  being  taken  out  of  the  trough,  is  cut  into  cubical  lumps. 
These  are  piled  in  heaps,  and  left  in  a  damp  cellar  for  a  considerable  time ;  that  is, 
several  months,  in  large  manufactories.  Here  the  dough  suffers  disintegration,  pronoted 
by  a  kind  of  fermentative  action,  due  probably  to  some  vegetable  matter  in  the  vratei 

Vol.  II  8  0 


466 


POTTERY. 


Hi 


i-  y 

m 
m 


M  :, 


f 


and  the  clay ;  for  it  becomes  black,  and  exhales  a  fetid  n/?nr       tk  mi  3    ^. 

cious  particles  get  disintegrated  also  by  the  action  of  the  wnt.r^  argillaceous  and  siU. 
ware  made  with  old  paste  is  found  to  be  more  homo^eouT  £  ""  '"'^*  ^^^  '^'^'  ^^^ 
to  crack  or  to  get  disfigured  in  the  bakinra"  the  ware S^hh^'"'^  ^""^  ""'  '^  ^^^ 

But  this  chemical  comminution  must  be  aided  bTmp^^.-  ''^'^'''  P^'^^' 

which  is  called  the  potter^s  ,/o;,4TlS^;  It^on.is^Tn  "•''^'•^^^""^  '  the  first  of 
the  hands,  and,  with  a  twist  of  both  atCce  tearin^it  "nS  two  '"''"=  ^  "'^''•"^  ""^^^  ^" 
a  wire.     These  are  again  slapped  to-ethe.  with  fnr.'«  V  /^  two  pieces,  or  cuttmg  it  with 

ia  Which  they  adhered  beffe  S  thfn  dasirefd^Tin  a  Wd'^^^^^^^^  ts^'"  '^°"^  ^^«' 
torn  or  cut  asunder  at  Hcrht  jmcri^o •      1         ,   "      ."  woara.     ihe  mass  is  once  more 

fixed  ones)  are  minced  to  ^allmo^^^^^^^  reaction  of 

pressure  into  an^S"  of  tTeboXr^^  ^°'''^  ^'l^"^^^^  ^^ '^^  screw-like 

pipe  about  6  inches  square  proceed  TLdnulht''  ''iT"'-  ^'""^  ^'^^^'^  ^  ^^«"^«»tal 
and  is  then  cut  into  lengths  of  about*  12  inoh.  ^Vk  ""^"^.^  ^^  '''"^  *^^'"^"?^  ^^^^  «»tlet, 
back  into  the  cyIindL,'and  subSei  to  th/;.  ^'''  '^'^  ^'^^''''  ^'  ^"^"^^  ^--^  thrown 
luinps  have  their%articies  perfec  ]>  btnde^^^^^  "^^^^"  «"^  ^-^"' ^^^  ^he 

precede  their  being  set  aside  to  ripln  L  a  lamp  cd  lar  In  FrZll\r\^^'"''''''r^l 
IS  not  worked  in  such  a  machine;  but  aftefbdn'  beat  with  Z.  f  ^t;;"^^^^^  dough 
common  also  in  England,  it  is  laid  down  on  a  clel„  floor  and  Iw  t  °'^"-'''  ^  P'"^''^'^^ 
upon  it  with  naked  feet  for  a  considerable  time  w^lS  •  ^ '"^^^'^  '«  set  to  tread 
centre  to  the  circumference  and  f^om  d!  .u  '  ?  "  '"  *  ^^''^^  direction  from  the 
and  also  in  China  (to  jud'eVrom    Hp  rv     ^"^""?^^r^"ce  to  the  centre.      In  Sweden, 

ofmakingporSnMheday^sTroSLnt^^^^^^  ^r^'"*'"='  \^^'^  ^^P^^^^"'  t^^""  "^^nner' 
all  cases,\neaded  like  bakers  douoh  bv  foldin  "  Wt  T'  1  ^  "^^"-  ^^  ^^  ^^erwards,  in 
it  out,  aUernatelv.  "  '    ^  ^''^'^'''^  ^^''^  ^^'^  ^^'^  "!>«»  itself,  and  kneadLg 

eitre'VXn'b^Lt^ra'n'dtlu^^^^^  ^  l^^^^^-  -^'^  ^  -e,  lifting  up 

violent  treatment  of^   laris  repea^dS^^^^^^^^^^  ^''"^'"'r'  ""  ^^^  ^^^^^'  ^"^^^^^^^ 

for  the  smallest  remaining  vesicle  exnandklTnLL-^^^^  air-bubbles  is  removed, 

warts  upon  the  ware  expanding  in  the  kiln,  would  be  apt  to  cause  blisters  oi 

^t^^^:t^tJ^:IZ^^  P--^  -  have  next  to  describe 

con^stroTl^up^trrlTara  This   " 

is  fixed,  by  its  cent're,  a  hori^onJardisc  or  ckf  llr  nLcn^wniS^^'^  ""  '^'  ''^  ^^^^^^^^ 
great  for  the  largest  stoneware  vessel  to  sLnduX      The  o?^^^^^^ 
ed,and  runs  in  a  conical  step,  and   its  collar    a  little  hplnJ^Lt      u      ?^^^. '' P**'"^- 
turned,  is  embraced  in  a  socket  attached  to  the  wooden  f.^r^^^^  r .if  ^'^^'i,  ^^ing  truly 
a  pulley  fixed  upon  it,  with  grooves  for  3  soeedso^^^^^^  ^  ^^'J^'^'u     ^^"  ^^«^^  ^^ 

a  fly-wheel,  by  whose^evolut  oHny  deLedranidi^vof  rn  .^  '"^^u'  ''•^"^  P^^sesfrom 
and  its  top-board.  This  wheeT  when  sriall  Zlfll  f /^'^i'^l^  "^^^  ^^^  gi^en  to  the  shaft 
lathe,  and  then  it  is  driven  by  a  tTeadle  and'o^nl  i  '1?  '^"?'^^''  *^^  '"^  '^^  '^'^^^^ 
turned  by  the  arms  of  aUorer  ^nlr  ^  I  "7  Y^^"  ""^  ^^"S^"*  dimensions,  it  is* 
a  large  thick  c^scT Par  fp^^^^^^^^^  whTch  rw^'tf ' '^"7?"^"'^  plate  is  replaced  by 
without  the  interventln  of'atu^Iey  and  fly  w^^^^^^^  TnTlff^'''  hand  of  the  potter^ 
power  for  fashioning  small  ve^^sels       The  mlT^^^^^  centrifugal 

or  gauged  by  an  experienced  hand  The  ^0^^?  1°  »>«  ^^rown,  is  weighed  out 
centre  of  the  revolving  boardTanddiLnc^hrshanrr  ""'^ff  ^^""^  ^^'  ^"°^P  «"  the 
water,  he  works  up  the  clay  into  a  ^Sl  Lf^^^^^^  »"*,  of 

alternately,  till  he  has  secured  the  finii  /?•    ,  *^>^';^e^  ^nd  then  down  into  a  cake. 

proper  for'i  to  the  veUTunder  a^t  spe  roTrltn'^'-^^^^^  ^^^^  ^^^  ^^« 

wooden  pegs  and  gauges.  He  now  cm!  Jr^off  f  .v,  u  ^'''"'  regulating  its  dimensions  by 
fastened\o\  handle  at  either  end  The  vesllthtt  ^'?  w  t""'''''  ?^«"«  brass  wire, 
tuation  where  it  may  dry  -raduali;  to  a  nif  •  !  ""^^^^  fashioned  is  placed  in  a  si- 
called  the  green  state,  iPpLssesses  a^l?;^^;'  P^!"';^  ^'  *  ^^''^^^  «»«?«  of  the  dning. 
It  is  then  tfken  to  anotheMSe?calfed  the  turnin//?r  ^V'"^.'^^"'  ^"*  ^*  ^^  »>^ked: 
moisture  to  the  vertical  face  of  kwoodei  chuck  an'^'  ^  '^  '^  '  ^"^'^'"^  ^^  ^  "'"^ 
with  a  very  sharp  tool,  which  alL  s^o"hs^r\fteVth^^^^  '""'"rlTV''  ^^Pf  '^''^ 
'     oth  steel  surface.  ^"^^  ^^^^  *'  ?  ^^'S^tly  burnished  with  11 


POTTERY. 


467 


DESCKIPTION   OF  THE  P0TTEB*S   LATHE. 

A,  /g.  1148,  is  the  profile  of  the  English  potter's  lathe,  for  blocking  oot  round 
ware ;  c  is  the  table  or  tray ;  a  is  the  head  of  the  lathe,  with  its  horizontal  disc ;  a,  6, 
is  the  upright  shaft  of  the  head;  d,  pulleys  with  several  grooves  of  dill'erent 
diameters,  fixed  upon  the  shaft,  for  receiving  the  driving-cord  or  band ;  fe  is  a  bench 
upon  which  the  workman  sits  astride ;  «,  the  treadle  fool-board ;  Ms  a  ledge-board, 


for  catching  the  shavings  of  clay  which  fly  off  from  the  lathe ;  A  is  an  instrument, 
with  a  slide-nut  i,  for  measuring  the  objects  in  the  blocking  out;  c  is  the  fly-wheel 
with  its  winch-handle  r,  turned  by  an  assistant ;  the  sole-frame  is  secured  in  its  place 
by  the  heavy  stone  p ;  /is  the  oblong  guide-pulley,  having  also  several  grooves  for  con- 
verting the  vertical  movement  of  the  fly-wheel  into  the  horizontal  movement  of  the  head 
of  the  lathe. 

D  is  one  of  the  intermediate  forms  given  by  the  potter  to  the  ball  of  clay,  as  it  revolves 
upon  the  head  of  the  lathe. 

In  large  potteries,  the  whole  of  the  lathes,  both  for  throwing  and  turning,  are  put  ia 
motion  by  a  steam-engine.  The  vertical  spindle  of  the  lathe  has  a  bevel  wheel  on  it, 
which  works  in  another  bevel  toothed  wheel  fixed  to  a  horizontal  shaft.  This  shaft  is 
provided  with  a  long  conical  wooden  drum,  from  which  a  strap  ascends  to  a  similar  co- 
nical drum  on  the  main  lying  shaft.  The  apex  of  the  one  cone  corresponds  to  the  base 
of  the  other,  which  allows  the  strap  to  retain  the  same  degree  of  tension  (see  the  conical 
drum  apparatus  of  the  Stearinc-press),  while  it  is  made  to  traverse  horizontally,  in  order 
to  vary  the  speed  of  the  lathe  at  pleasure.  When  the  belt  is  at  the  base  of  the  driving- 
cone,  it  works  near  the  vertex  of  the  driven  one,  so  as  to  give  a  maximum  velocity  to  the 
lathe,  and  vice  versa. 

During  the  throwing  of  any  article,  a  separate  mechanism  is  conducted  by  a  boy, 
which  makes  the  strap  move  parallel  to  itself  along  these  conical  drums,  and  nicely  re- 
gulates the  speed  of  the  lathe.  When  the  strap  runs  at  the  middle  of  the  cones,  the 
velocity  of  each  shaft  is  equal.  By  this  elegant  contrivance  of  parallel  cones  revei-se^ 
the  velocity  rises  gradually  to  its  maximum,  and  returns  to  its  minimum  or  slower  motion 
when  the  workman  is  about  finishing  the  article  thrown.  The  strap  is  then  transferred  to 
a  pair  of  loose  pulleys,  and  the  lathe  stops.  The  vessel  is  now  cut  off  at  the  base  with 
small  wire ;  is  dried,  turned  on  a  power  lathe,  and  polished  as  above  described. 

The  same  degree  of  dryness  which  admits  of  the  clay  being  turned  on  the  laihe,  also 
suits  for  fixing  on  the  handles  and  other  appendages  to  the  vessels.  The  parts  to  be 
attached,  being  previously  prepared,  are  joined  to  the  circular  work  by  means  of  a  thin  paste 
which  the  workmen  call  slip,  and  the  seams  are  then  smoothed  off  with  a  wet  sponge. 
They  are  now  taken  to  a  stove-room  heated  to  80**  or  90**  F.,  and  fitted  up  with  a  great  many 
shelves.  When  they  are  fully  dried,  they  are  smoothed  over  with  a  small  bundle  cf  hemp, 
if  the  articles  be  fine,  and  are  then  ready  for  the  kiln,  which  is  to  convert  the  tender  clay 
into  the  hard  biscuit. 

A  great  variety  of  pottery  wares,  however,  cannot  be  fashioned  on  the  lathe,  as  they 
are  not  of  a  circular  form.  These  are  made  by  two  different  methods,  the  one  called 
press-work,  and  the  other  casting.  The  press-work  is  done  in  moulds  made  of  Paris 
plaster,  the  one  half  of  the  pattern  being  formed  in  the  one  side  of  the  mould,  and  the 
other  half  in  the  other  side :  these  moulding-pieces  fit  accurately  together.  All  vessels 
of  an  oval  form,  and  such  as  have  flat  sides,  are  made  in  this  way.  Handles  of  tea- 
pots, and  fluted  solid  rods  of  various  shapes,  are  formed  by  pressure  also ;  viz.,  by 
squeezing  the  dough  contained  in  a  pump-barrel  through  diflferent  shaped  orifices  at  its  hot- 
torn,  by  working  a  screw  applied  to  the  piston-rod.  The  worm-shaped  dough,  as  it  issues, 
is  cut  to  proper  lengths,  and  bent  into  the  desired  form.  Tubes  may  be  also  made  on  the 
same  pressure  principle,  only  a  tubular  opening  must  be  provided  in  the  bottom  plate  of 
the  clay-forcing  pump. 


I 


i  I 


•;i!i 


468 


FOTTERY. 


The  other  method  of  fashioning  earthenware  articles  is  caUed  casting,  and  is,  perhaps, 
the  most  elegant  for  such  as  have  an  irregular  shape.  This  operation  consists  in  pour, 
ing  the  clay,  in  the  state  of  pap  or  slip,  into  plaster  moulds,  which  are  kept  in  Ji 
desiccated  state.  These  moulds,  as  well  as  the  pressure  ones,  are  made  in  halves  which 
nicely  correspond  together.  The  slip  is  poured  in  till  the  cavity  is  quite  full,  and  is 
left  m  the  mould  for  a  certain  time,  more  or  less,  according  to  the  intended  thickness  of 
the  vessel.  The  absorbent  power  of  the  plaster  soon  abstracts  the  water,  and  makes  the 
coat  of  clay  m  contact  with  it  quite  doughy  and  stiff;  so  that  the  part  still  liquid  being 
poured  out,  a  hollow  shape  remains,  which  when  removed  from  the  mould  constitutes 
the  half  of  the  vessel,  bearing  externally  the  exact  impress  of  the  mould.  The  thickness 
of  the  clay  varies  with  the  time  that  the  paste  has  stood  upon  the  plaster.  These  cast 
articles  are  dried  to  the  green  slate,  like  the  preceding,  and  then  joined  accurately  with 
slip.  Imitations  of  flowers  and  foliage  are  elegantly  executed  in  this  way.  This 
operation,  which  is  called  furnishing,  requires  very  delicate  and  dexterous  manipu- 
lation. *^ 

The  saggers  for  the  unglazed  colored  stoneware  should  be  covered  inside  with  a 
glaze  composed  of  12  parts  of  common  salt  and  30  of  potash,  or  6  parts  of  potash  and 
14  of  salt ;  which  may  be  mixed  with  a  little  of  the  common  enamel  for  the  glazed 
pottery  saggers.  The  bottom  of  each  sagger  has  some  bits  of  flints  sprinkled  upon  it, 
which  become  so  adherent  after  the  first  firing  as  to  form  a  multitude  of  little  promi- 
nences for  setting  the  ware  upon,  when  this  does  not  consist  of  plates.  It  is  the  dutv 
of  the  workmen  belonging  to  the  glaze  kiln  to  make  the  saggers  during  the  intervals 
of  their  work  j  or,  if  there  be  a  relay  of  hands,  the  man  who  is  not  firing  makes  the 
saggei-s.     . 

The  English  kilns  difler  from  those  of  France  and  Germany,  in  their  construction,  in  the 
nature  of  their  fuel,  and  in  the  high  temperature  required  to  produce  a  surface  suflUciently 
hard  for  a  perfectly  fine  glaze. 

When  the  ware  is  sufliciently  dry,  and  in  sufllicient  quantity  to  fill  a  kiln,  the  next 
process  is  placing  the  various  articles  in  the  baked  fire-clay  vessels,  which  may  be  either 
of  a  cylindrical  or  oval  shape  ;  called  gazettes,  Fr. ;  kapseln.  Germ.  These  are  from  6 
to  8  inches  deep,  and  from  12  to  18  inches  in  diameter.  When  packed  full  of  the  dry 
ware,  they  are  piled  over  each  other  in  the  kiln.  The  bottom  of  the  upper  sagger  forms 
the  lid  of  its  fellow  below ;  and  the  junction  of  the  two  is  luted  with  a  ring  of  soft  clay 
applied  between  them.  These  dishes  protect  the  ware  froin  being  suddenly  and  unequally 
heated,  and  from  being  soiled  by  the  smoke  and  vapors  of  the  fuel.  Each  pile  of  saggers 
is  called  a  bung. 

POTTERY   KILX   OF   STAFFORDSHIRE, 

Figs.  1149,  60,  61,  62,  63.,  represent  the  kiln  for  baking  the  biscuit,  and  also  forrmi- 
ning  the  glaze,  in  the  English  pottenes. 

1160 


1161 


■J Uti 


ii 


POTTERY. 


469 


1152 


a,  «,  figs.  1149, 1160.1161.  are  the  furnaces  which  heat  the  kiln ;  of  which  h,  in^g 
1U9  are  the  upper  mouths,  and  6'  the  lower ;  the  former  being  closed  more  or  less  by  the 
flre-tile  z,  shown  in  ^g.  1153.  -    ,.    .  x     ^^Ko 

/is  one  fireplace  ;  for  the  manner  of  distributing  the  fuel  in  it,  see  fig.  115d. 

It  V  Hzs  1149  and  1153  are  the  horizontal  and  vertical  flues  and  chimneys  for  con- 
duSing  the'flame  and  smoke.  /  is  the  laboratory,  or  body  of  the  kiln ;  leaving  its^oor 
k  sloping  sliffhtly  downwards  from  the  centre  to  the  circumference,  x,  V*  «  ^he  slit  of 
the  horizontal  register,  leading  to  the  chimney  flue  y  of  the  furnace,  being  the  first  regu 
lator;  x,  «,  is  the  vertical  register  conduit,  leading  to  the  furnace  or  mouth  /,  be  ng  he 
second  regulator;  v  is  the  register  slit  above  the  furnace  and  its  vertical  flue  leading 
into  the  b^y  of  the  kiln ;  v\  c,  slit  for  regulating  flue  at  the  shoulder  of  the  kUn  ;  t  ^ 
an  arch  which  supports  the  walls  of  the  kUn,  when  the  furnace  is  ^^^^^H^^^'^  ^"l 
are  small  flues  in  the  vault  s  of  the  laboratory.    h,fig.  1160,is  the  central  flue,  called 

ian«/<c,  of  the  laboratory.  ,      .,  .        r  •    «  v^^«-      «.' ;o  tko 

T,  T,  is  the  conical  tower  or  howell,  strengthened  with  a  series  of  iron  hoops,     o  x%Xhe 

great  chimney  or  lunette  of  the  tower ;  p  is  the  door  of  the  laboratory,  bound  inside  with 

an  iron  frame.  ^  .^  ^^^  complete  kiln  and  howdl,  with  all  its  appurte- 

B,  /ig.  1150,  is  the  plan  at  the  level  a,  J,  of  the  floor,  to 
show  the  arrangement  and  distribution  of  all  the  horizontal 
flues,  both  circular  and  radiating. 

c,  fig.  1161  is  a  plan  at  the  level  «, «,  of  the  upper  mouths  6, 
of  the  furnaces,  to  show  the  disposition  of  the  fireplaces  of  the 
vertical  flues,  and  of  the  horizontal  registers,  or  peep-holes. 

D  yig.  1151  is  a  bird's-eye  view  of  the  top  of  the  vault  or 
dome  s,  to  show  the  disposition  of  the  vent-holes  c,  c. 

E,  fig.  1162  is  a  detailed  plan  at  the  level  c,  c,  of  one  lur- 
nace  and  its  dependencies.  ,      .,     /•        c 

F,fig.  1153  is  a  transverse  section,  in  detaU,  of  one  lumace 
and  its  dependencies. 

The  same  letters  in  all  the  figures  indicate  the  same  ob- 

^^^Chargingofthe  kiln.— The  saggers  are  piled  up  first  in  the 
space  between  each  of  the  upright  furnaces,  till  they  rise  to 

.-  -  the  top  of  the  flues.      These  contain  the  smaller  articles. 

Above  this  level,  lar-e  fire  tiles  are  laid,  for  supporting  other  saggers,  filled  ^^'^^  teacups, 
suTarVasins,  &c.     In  the  bottom  part  of  the  pile,  within  the  preceding,  the  same  sorts  of 
arScles  are  put ;  but  in  the  upper  part  all  such  articles  are  placed  as  require  a  high  heat. 
Cr  pnrorsmail  sa^^^^      wkh  a  middle  one  10  incnes  in  height,  complete  the  charge 
is  there  are  6  piles  beTweei  each  furnace,  and  as  the  biscuit  kiln  has  8  <^-rnace«' ^  charge 
consequently  amounts  to  48  or  50  bungs,  each  composed  of  from  18  to  f  .s^ff/^'   Jhe 
Llination  of  the  bungs  ought  always  to  follow  the  form  of  the  kiln,  and  s\«;\d  ^he'-efore 
end  towards  the  centre,  lest  the  strong  draught  of  the  furnaces  should  make  the  saggers 
fall  against  the  walls  of  the  kiln,  an  accident  apt  to  happen  were  these  piles  perpendicular. 
The  last  sa-er  of  each  bung  is  covered  with  an  unbaked  one,  three  inches  deep,  in  place 
of  a  round  lid.    The  watches  are  small  cups,  of  the  same  b^^cuit  as  the  charge  placed  m 
sLgers^  four  in  number,  above  the  level  of  the  flue-tops.    They  are  taken  hastily  out  of 
the  saggers,  lest  they  should  get  smoked,  and  are  thrown  into  cold  water. 

When  the  charging  is  completed,  the  firing  is  commenced,  with  coal  of  the  best  quali^. 
The  management  of  the  furnace  is  a  matter  of  great  consequence  to  the  success  of  the 
process.  No  greater  heat  should  be  employed  for  some  time  than  may  be  necessary  to 
a--lutinate  the  particles  which  enter  into  the  composition  of  the  paste,  by  evaporating  all 
the  humidity  ;  and  the  heat  should  never  be  raised  so  high  as  to  endanger  the  fusion  of 
the  ware,  which  would  make  it  very  brittle. 

Whenever  the  mouth  or  door  of  the  kiln  is  built  up,  a  child  prepares  several  fires  m  the 
nei-hborhood  of  the  AoireZ/,  while  a  laborer  transports  in  a  wheelbarrow  a  supply  of 
coals  and  introduces  into  each  furnace  a  number  of  lumps.     These  lumps  divide  the  fur- 
nace  into  two  parts ;  those  for  the  upper  flues  being  placed  above,  and  those  for  the  ground 
flues  below,  which  must  be  kept  unobstructed.  .      ,   ,  .        .  i  ♦^. 

The  fire-mouth,  being  charged,  they  are  kindled  to  begin  the  baking,  the  regulator 
tilez  He  1153, being  now  opened;  an  hour  afterwards  the  bricks  at  the  bottom  oi  me 
furnace  are  stopped  up.  The  fire  is  usually  kindled  at  6  o'clock  in  the  evening,  and 
wo"  re^siveh'  increased  till  10,  when  it  begins  to  gain  force,  and  the  flame  rises  half-way  up 
theSney?  The  second  charge  is  put  in  at  8  o'clock,  and  the  mouths  of  the  furnaces  are 
then  coverS  with  tiles ;  by  which  time  the  flame  issues  through  the  vent  of  the  tower.  Aa 
h^^  Xrwards  a  fresh  charge  is  made ;  the  tiles  z,  which  cover  the  furnaces,  are  slipped 


i 


Si 


470 


POTTERY. 


POTTERY. 


471 


,  1 

1 .  • 


back ;  the  cinders  are  drawn  to  the  front,  and  reph  ted  with  small  coal.  About  hall 
past  1 1  o'clock  the  kiln-man  examines  his  furnaces,  to  see  that  their  draught  is  pro- 
perly regulated.  An  hour  afterwards  a  new  charge  of  coal  is  applied ;  a  practice  repeated 
hourly  tfu  6  o'clock  in  the  morning.  At  this  moment  he  takes  out  his  first  watch,  to 
see  how  the  baking  goes  on.  It  should  be  at  a  very  pale-red  heat ;  but  the  watch  of  7 
o'clock  should  be  a  deeper  red.  He  removes  the  tiles  from  those  furnaces  which  appear  to 
have  been  burning  too  strongly,  or  whose  flame  issues  by  the  orifices  made  in  the  shoulder 
of  the  kiln;  and  puts  tiles  upon  those  which  are  not  hot  enough.  The  flames  glide 
along  briskly  in  a  regular  manner.  At  this  period  he  draws  out  the  watches  every 
quarter  of  an  hour,  and  compares  them  with  those  reserved  from  a  previous  standard 
kiln :  and  if  he  observes  a  similarity  of  appearance,  he  allows  the  furnaces  to  burn  a 
little  longer ;  then  opens  the  mouths  caiefully  and  by  slow  degrees ;  so  as  to  lower  the 
heat,  and  finish  the  round. 

The  baking  usually  lasts  from  40  to  42  hours ;  in  which  time  the  biscuit  kiln  may  con-» 
sume  14  tons  of  coals  ;  of  which  four  are  put  in  the  first  day,  seven  the  next  day  and  fol- 
lowing night,  and  the  four  last  give  the  strong  finishing  heat. 

Emptying  the  fciM.— The  kiln  is  allowed  to  cool  very  slowly.  On  taking  the  ware 
out  of  the  saggers,  the  biscuit  is  not  subjected  to  friction,  as  in  the  foreign  i>s./.teries, 
because  it  is  smooth  enough ;  but  is  immediately  transported  to  the  place  where  it  is  to 
be  dipped  in  the  glaze  or  enamel  tub.  A  child  makes  the  pieces  ring,  by  striking  with  the 
handle  of  the  brush,  as  he  dusts  them,  and  then  immerses  them  into  the  glaze  cream  ; 
from  which  tub  thev  are  taken  out  by  the  enamellcr,  and  shaken  in  the  air.  The  tub 
usually  contains  no' more  than  4  or  5  inches  depth  of  the  glaze,  to  enable  the  workman 
to  pick  out  the  articles  more  readily,  and  to  lay  them  upon  a  board,  whence  they  are 
taken  by  a  child  to  the  glaze  kiln. 

Glazing. — A  good  enamel  is  an  essential  element  of  fine  stoneware ;  it  should  experi- 
ence the  same  dilatation  and  contraction  by  heat  and  cold  as  the  biscuit  which  it  covers. 
The  English  enamels  contain  nothing  prejudicial  to  health,  as  many  of  the  foreign  glazes 
do ;  no  more  lead  being  added  to  the  former  than  is  absolutely  necessary  to  convert  the 
sili'cious  and  aluminous  matters  with  which  it  is  mixed  into  a  perfectly  neutral  class. 

Three  kinds  of  glazes  are  used  in  Staflordshire ;  one  for  the  common  pipe-clay  or 
cream-colored  ware;  another  for  the  finer  pipe-clay  ware  to  receive  impressions, 
called  printing  body ;  a  third  for  the  ware  which  is  to  be  ornamented  by  painting  with  the 

The  glaze  of  the  first  or  common  ware  is  composed  of  .53  parts  of  white  lead,  16  of 
Cornish  stone,  36  of  ground  flints,  and  4  of  flint  glass;  or  of  40  of  white  lead,  36  of  Cor- 
nish stone,  12  of  flints,  and  4  of  flint  or  crystal  glass.  These  compositions  are  not  fritted ; 
but  are  employed  alter  being  simply  triturated  with  water  into  a  thin  paste. 

The  following  is  the  composition  of  the  glaze  intended  to  cover  all  kinds  of  figures 
primed  in  metallic  colors ;  26  parts  of  white  feldspar  are  fritted  with  6  parts  of  soda,  2  of 
nitre,  and  1  of  borax ;  to  20  pounds  of  this  frit,  26  parts  of  feldspar,  20  of  white  lead,  6 
of  ground  flints,  4  of  chalk,  1  of  oxyde  of  tin,  and  a  small  quantity  of  oxyde  of  cobalt,  to 
take  off  the  brown  cast,  and  give  a  faint  azure  tint,  are  added. 

The  following  recipe  may  also  be  used.     Frit  together  20  parts  of  flint  glass,  6  of  flints, 
2  of  nitre,  and  1  of  br.rax;  add  to  12  parts  of  that  frit,  40  parts  of  white  lead,  36  of  feld 
spar,  8  of  flints,  and  6  of  flint  glass ;  then  grind  the  whole  together  into  a  uniform  cream- 

consistenced  paste.  ...  j    r  io 

As  to  the  stoneware  which  is  to  be  painted,  it  is  covered  with  a  glaze  composed  ol  13 
parts  of  the  printing-color  frit,  to  which  are  added  50  parts  of  red  lead,  40  of  white  lead, 
and  12  of  flint ;  the  whole  having  been  ground  together. 

The  above  compositions  produce  a  very  hard  glaze,  which  cannot  be  scratched  by  the 
knife,  is  not  acted  upon  by  vegetable  acids,  and  does  no  injury  to  potable  or  edible  arti- 
cles kept  in  the  vessels  covered  with  it.  It  preserves  for  an  indefinite  time  the  glassy 
lustre,  and  is  not  subject  to  crack  and  exfoliate,  like  most  of  the  Continental  stoneware 
made  from  common  pipe-clay. 

In  order  that  the  saggers  in  which  the  articles  are  baked,  after  receiving  the  glaze,  may 
not  absorb  some  of  the  vitrifying  matter,  they  are  themselves  coated,  as  above  mentioned, 
with  a  glaze  composed  of  13  parts  of  common  salt,  and  30  parts  of  potash,  simply  dissolved 
in  water,  and  brushed  over  them. 

Glaze  kiln.— This  is  usually  smaller  than  the  biscuit  kiln,  and  contains  no  more  than 
40  or  45  bungs  or  columns,  each  composed  of  16  or  17  saggers.  Those  of  the  first  bung 
rest  upon  round  tiles,  and  are  well  luted  together  with  a  finely  ground  fire-clay  of  only 
moderate  cohesion  ;  those  of  the  second  bung  are  supported  by  an  additional  tile.  Th€ 
lower  sa^^^ers  contain  the  cream-colored  articles,  in  which  the  glaze  is  softer  than  that 
which  covers  the  blue  printed  ware ;  this  being  always  placed  in  the  intervals  between 
the  furnaces,  and  in  the  uppermost  saggers  of  the  columns.  The  bottom  of  the  kiln, 
where  the  glazed  ware  is  not  baked,  is  occupied  by  printed  biscuit  ware. 


Pyrometric  balls  of  red  clay,  coated  with  a  very  fusible  I'^^d  enamel,  are  employed  m. 
the  English  potteries  to  ascertain  the  temperature  of  the  ^/^^^/^l"^-  ^^his  enameUs  80 
tiM,  «nd  the  clav  upon  which  it  is  spread  is  so  fine-grained  and  compact,  that  even  wnen 
exnosed  for  th  el  SoursTo  the  briskest  flame,  it  does  not  lose  its  lustre  The  color  of 
^uIZTv  «lnne  chanee«;  wherebv  the  workman  is  enabled  to    udge  of  the  degree  of  heal 

•tVn  ^he  ki?n  At  f&Uhe  b^^^  have  a  pale  red  appearance ;  but  they  become  browner 
w!h  the  inc  ease  of  thf temperature.  The  balls,  when  of  a  slightly  dark-red  color,  indi- 
Tate  the  de^Tof^^^^^^^  1^-d  glaze  of  pipe-clay  ware;  but  if  they  become  dark 

brown  the  glaze  will  be  much  too  hard,  being  that  suited  for  trmstane  ware ;  lastl} ,  when 
?he7acqufre  an  almost  black  hue,  they  show  a  degree  of  heat  suited  to  the  formation  of 

*  t^S"^^^  himself  at  each  round  with  a  stock  of  these  ball  watckes,  reserved 
from  the  preceding  baking,  to  serve  as  objects  of  comparison;  and  he  never  slackens  the 
S-  till  he  has  obtained  the  same  depth  of  shade,  or  even  somewhat  more;  for  t 
mavCremark^,  that  the  more  rounds  a  glaze  kiln  has  made,  the  browner  tne  balk 
may  be  remariveu,  enamel-ware  sooner  than  an  old  one ; 

Z\Z':itleM^n^^^^^^^  The  watch-balls  of  these  first  rounds 

Save  geTerah  not  so  deep  a  color  as  if  they  were  tried  m  a  furnace  three  or  fou^ 
nTonthf  old  After  this  period,  cracks  begin  to  appear  m  the  furnaces ;  th.  horizontal 
Zes  'ot  parttau/  obstructed, 'the  joinings  of  the  brickwork  become  loose;  m  conse- 
.""  nV  wWh  here  is  a  loss  of  heat  and  waste  of  fuel ;  the  baking  of  the  glaze  takes 
STon'er  ime  aVd  he  p^rometrL  balls  assume  a  different  shade  from  what  they  had  on 
a  longer  time,  anu  I       i  watches  are  of  no  comparable  use  after 

twofnonth^  '"The  baking  of  enamel  is  commenced  at  a  low  temperature,  and  the  heat 
irnrreWly  increased;  when  it  reaches  the  melting  point  of  the  glaze,  it   must  be 

Ltefed'by  :ufhraddmr  k  fueH  afte?which  the  kiln  is  allowed  from  5  to  6  hours  to 

^^liump.  -The  naintin-s  and  the    printed  figures  applied   to  the   glaze  of   stone- 
Muffles.—  lhe  pamun^t,  ^^^^  ^^^  porcelain  are  baked  m  muffles 

of  a  peculiar  form.  Fig.  1154.  is  a  lateral 
elevation  of  one  of  these  muffles  ;  yjg.1155 
is  a  front  view.  The  same  letters  denote 
the  same  parts  in  the  two  figures. 

a  is  the  furnace ;  6,  the  oblong  muffle, 
made  of  fire-clay,  surmounted  with  a  dome 
pierced  with  three  apertures  k,  k,  k,  for  the 
escape  of  the  vaporous  matters  of  the  col- 
ors and  volatile  oils  with  which  they  are 
ground  up ;  c  is  the  chimney ;  d,  d,  feed- 
holes,  by  which  the  fuel  is  introduced ;  «, 
the  fire-grate  ;  /,  the  ash-pit;  channels  arc 
u,  .    ^    ,     ^,      .^  .    -  ■    ,^  ■  left  in  the  bottom  of  the  furnace  to  facih- 

tate  the  passage  c^-  the  flame  ^-eath  th^  mur^^^^^^^^^^^  thS  mt^o^lStX^^^^^^^^ 
eommunication  across  the  fumace^m^^  ^^  ^,^  ,^.^^  ,, 

is  passing  withm ;  k,  k,  are  the  ^.^^^'^^^J"^^  .    f  ^^^  chimney  to  modify  its  draught, 
flame;  ^  i^  ^n  opening  ^^X)ped  out  m  the  front  o^^^^^  placed  in  the  muffle 

The  articles  which  Y^J^-'^^Zv^lsx^vm^^^  ^^^t.     The  muffle 

without  saggers,  upon  tripods,  or  «^97^^f  ^^^/X""^^^^  ^ound  its  edges.     The  fuel 

being  charged,  its  mouth  »^<^^«^^d  w^^^h  a  fir^tile  well  M  ^ 

is  then  kindled  in  the  f^^^'V^^^^K^; f^^^^ out.tples,  and  for  examining  the  interior  of 
in  which  a  small  openmg  is  left  for  .t^^^i^^^^^^^^^o  a  stron-  iron  wire,  show  the  progress 

Xe  the  muffle  on  an  sides  and  thence  rises  «p  the  cl,^^^^^^^^^ 
also' to  aid  in  fluxing  the  cobalt. 


■  I . 


lit  I '11 


i; 


m 


472 


POTTERY. 


The  following  are  the  processes  tvsually  practised  in  Staffordshire  for  printing  nndef 
the  glaze. 

The  cobalt,  or  whatever  color  is  employed,  should  be  ground  upon  a  porphyry  slab, 
with  a  varnish  prepared  as  follows: — A  pint  of  linseed  oil  is  to  be  boiled  to  the  consist- 
ence of  thick  honey,  along  with  4  ounces  of  rosin,  half  a  pound  of  tar,  and  half  a  pint  of 
oil  of  amber.  This  is  very  tenacious,  and  can  be  used  only  when  liquefied  by  heat ;  which 
the  printer  effects  by  spreading  it  upon  a  hot  cast-iron  plate. 

The  printing  plates  are  made  of  copper,  engraved  with  pretty  deep  lines  in  the  common 
way.  The  printer,  with  a  leather  muUer,  spreads  upon  the  engraved  plate,  previously 
heated,  his  color,  mixed  up  with  the  above  oil  varnish,  and  removes  what  is  superfluous 
with  a  pallet  knife ;  then  cleans  the  plate  with  a  dossil  filled  with  bran,  tapping  and  wiping 
as  if  he  were  removing  dust  from  it.  This  operation  being  finished,  he  takes  the  paper 
intended  to  receive  the  impression,  soaks  it  with  soap-water,  and  lays  it  moist  upon 
the  copper-plate.  The  soap  makes  the  paper  part  more  readily  from  the  copper,  and  the 
thick  ink  part  more  readily  from  the  biscuit.  The  copper-plate  is  now  passed  through  the 
engraver's  cylinder  press,  the  proof  leaf  is  lifted  off  and  handed  to  the  women,  who  cut  it 
into  detached  pieces,  which  they  apply  to  the  surface  of  the  biscuit.  The  paper  best  fitted 
for  this  purpose  is  maJe  entirely  of  linen  rags ;  it  is  very  thin,  of  a  yellow  color,  and 
unsized,  like  tissue  blotting-paper. 

The  stoneware  biscuit  never  receives  any  preparation  before  being  imprinted,  the  oil 
of  the  color  being  of  such  a  nature  as  to  fix  the  figures  firmly.  The  printed  paper  is 
pressed  and  rubbed  on  with  a  roll  of  flannel,  about  an  inch  and  a  half  in  diameter,  and  12 
or  15  inches  Ions,  bound  round  with  twine,  like  a  roll  of  tobacco.  This  is  used  as  a 
burnisher,  one  end  of  it  being  rested  against  the  shoulder,  and  the  other  end  being  rubbed 
upon  the  paper  ;  by  which  means  it  transfers  all  the  engraved  traces  to  the  biscuit.  The 
piece  of  biscuit  is  laid  aside  for  a  little,  in  order  that  the  color  may  take  fast  hold ;  it  is 
then  plunged  into  water,  and  the  paper  is  washed  away  with  a  sponge. 

When  the  paper  is  detached,  the  piece  of  ware  is  dipped  into  a  caustic  alkaline  ley  to 
saponify  the  oil,  after  which  it  is  immersed  in  the  glaze  liquor,  with  which  the  printed 
figures  readily  adhere.  This  process,  which  is  easy  to  execute,  and  very  economical,  is 
much  preferable  to  the  old  plan  of  passing  the  biscuit  into  the  muffle  after  it  had  been 
printed,  for  the  purpose  of  fixing  and  volatilizing  the  oils.  When  the  paper  impression 
is  applied  to  pieces  of  porcelain,  they  are  heated  before,  being  dipped  in  the  water,  be- 
cause, being  already  semi-vilnfied,  the  paper  sticks  more  closely  to  them  than  to  the  bis- 
cuit, and  can  be  removed  only  by  a  hard  brush. 

The  impression  above  the  glaze  is  done  by  quite  a  different  process,  which  dispense? 
with  the  use  of  the  press.  A  quantity  of  fine  clean  glue  is  melted  and  poured  hot  upon 
a  large  flat  dish,  so  as  to  form  a  layer  about  a  quarter  of  an  inch  thick,  and  of  the  consist- 
ence of  jelly.  When  cold  it  is  divided  into  cakes  of  the  size  of  the  copper-plates  it  is  in- 
tended to  cover. 

The  operative  (a  woman)  rubs  the  engraved  copper-plate  gently  over  with  linseed  oil 
boiled  thick,  immediately  after  which  she  applies  the  cake  of  glue,  which  she  presses  down 
with  a  silk  dossil  filled  with  bran.  The  cake  licks  up  all  the  oil  out  of  the  engraved  lines ; 
it  is  then  cautiously  lifted  off,  and  transferred  to  the  surface  of  the  glazed  ware  which 
it  is  intended  to  print.  The  glue  cake  being  removed,  the  enamel  surface  must  be  rubbed 
with  a  little  cotton,  whereby  the  metallic  colors  are  attached  only  on  the  lines  charged 
with  oil :  the  piece  is  then  heated  under  the  muffle.  The  same  cake  of  glue  may  serve 
for  several  impressions. 

Ornaments  and  co/ormg.— Common  stoneware  is  colored  by  means  of  two  kinds  of 
apparatus ;  the  one  called  the  blowing-pot,  the  other  the  worming-pot.  The  ornaments 
made  in  relief  in  France,  are  made  hollow  (intaglio)  in  England,  by  means  of  a  mould 
engraved  in  relief,  which  is  passed  over  the  article.  The  impression  which  it  produces 
is  filled  with  a  thick  clay  paste,  which  the  workman  throws  on  with  the  blowing-pot. 
This  is  a  vessel  like  a  tea-pot,  having  a  spout,  but  it  is  hermetically  sealed  at  top  with  a 
clay  plug,  after  being  filled  with  the  pasty  liquor.  The  workman,  by  blowing  in  at  the 
spout,  causes  the  liquor  to  fly  out  through  a  quill  pipe  which  goes  down  through  the 
clay  plug  into  the  liquor.  The  jet  is  made  to  play  upon  the  piece  while  it  is  being  turn- 
ed upon  the  lathe  ;  so  that  the  hollows  previously  made  in  it  by  the  mould  or  stamp  are 
filled  with  a  paste  of  a  color  different  from  that  of  the  body.  When  the  piece  has  acquired 
sufficient  firmness  to  bear  working,  the  excess  of  the  paste  is  removed  by  an  instrument 
called  a  tournasiny  till  the  ornamental  figure  produced  by  the  stamp  be  laid  bare; 
in  which  case  merely  the  color  appears  at  the  bottom  of  the  impression.  By  passing 
in  this  manner  several  layers  of  clay  liquor  of  different  colors  over  each  other  with  the 
Mowing-pot,  net-work,  aud  decorations  of  dinereut  colors  and  shades,  are  very  rapiuiy 
produced. 

The  seri)entine  or  snake  pots,  established  on  the  same  principle,  are  made  of  tin  plate 
In  three  compartments,  each  containing  a  different  color.     These  open  at  the  top  cf 


POTTERY. 


473 


the  vessel  in  a  common  orifice,  terminated  by  small  quill  tubes      ^l^^Hfi^e  l^d  are  ^i^t 
the  three  colors  flow  out  at  once  in  the  same  proportion  at  the  one  orifice  and  are  lei 
•all  upon  the  piece  while  it  is  being  slowly  turned  upon  ^^e  lathe  ;whereb>  c^unousser 
pent-like  ornaments  may  be  readily  obtained     The  clay  liquor  o^gl^;  /^^  Ide  wU^ 
u'?h  the  stoneware  paste.    The  blues  succeed  best  when  the  ornaments  are  made  witn 

''^iSrf:rf«^^^^^^^  -talUc  mstre  being  applied  only  to 

^:^r  «Lz:^!^  iL^:^o^d^of  a^;::J^^r^^ 

''The'"w;r  and  platina  lustres  are  usually  laid  upon  a  ^ ^^ rcol^red '4orn7' T^ 
and  copper,  en  account  of  their  transparency  succeed  only  "P?"  ^/^^r.  .^^^^^^ 

'••The  Stn"ZunXtre  is  almost  always  applied  lo  a  paste  body  made  on  purpose 
.nrc:a!:d':Uh  1  a^v^described  lead  glaze  This  paste  is  brown  and  co„.s^s  of 
4  nnru  nf  rlav  4  narts  of  fliuts,  an  equal  quantity  of  kaolin  (china  cla>),  ana  o  pans  oi 
fe£ar     To  make^b^^^^^  in  relief  upon  a  body  of  white  paste,  a  liquor  ,s  mixed 

uf  riUhilpa'CwhS  ought  to  weigh  26  ounces  per  pint,  in  order  to  unite  weU  with 

^^^£i;^^^ir  ::^:^^^-  '^r^  -d  then  .^^  --^^^^^ 

fine  gold  in  288  gfains  of  an  aqua  regia,  composed  of  1  ounce  ^^^'bi?    and  then  poTr 
of  muriatic  acid;  add  to  that  solution  4|  gr^^^^^,  f  §^^»%^'"' ^^^\V^^.,^„^^^^ 
some  of  that  compound  solution  into  20  S''^^"'^.  ^^  »'^1^'^°\^[  ^"^i*,^"' 
of  oil  of  turpentine.     The  balsam  of  sulphur  is  P^^P-'-^ed  by  heating  a  I^'^*  ^n^^^^f^^^^ 
and  2  ounces  of  flowers  of  sulphur,  stirring  them  continually  till  the  J"  f  ^[^  ^^-["^^^^^ 
boil  •  it  is  then  cooled,  by  setting  the  vessel  in  cold  water  ;  after  which  it  »7^»'^'^«^^^*^{;f^^> 
^nd  'stfafned  through  line'n.     The  above  ingredients,  after  being  ^^^^^^^^^^^^  \\l  f 
lowed  to  settle  for  a  few  minutes ;    then  the  remainder  of  the  solution  ol   gom   is  lo  oc 
po"  ed  in   and  the  wioTe  is  to  be  'trituiated  till  the  mass  has  assumed  such  a  consistence 
[hat  the  i;estle  will  stand  upright  in  it;  l^^^^y' ^?^^'^f,°^"^!,t.?reL  read,  to^rpplie^ 
grains  of  oil  of  turpentine,  which  being  ground  m,  ^^f  ?f^i"/H.".  ^ave  Lt  a  su^^^^^^^^ 
If  the  lustre  is  too  light  or  pale,  more  gold  must  be  added,  and  if  it  have  not  a  sumcieni 

ly  viclet  or  purple  tint,  more  tin  must  be  used.  „„i;c>,pH  ^terl  another 

^  Platina  lustrl-Or  this  there  are  two  kinds ;    one  ^^^'^f^^^^^^fj^^    111^1° ina 
lighter  and  of  a  silver-white  hue.     To  give  stoneware  the  steel  c^orwUii^latia^ 
this  metal  must  be  dissolved  in  an  aqua  regia  ^J^^P^^^^^^  ^  Parts  of  muriat  c  ac^^^ 
1  part  of  nitric.    The  solution  being  cooled,  and  poured  »^/° /^^^f  ^^J^f'!.  ^^^^^^ 
added  to  it,  drop  by  drop,  with  continual  stirring  with  a  ?^«VfiuVr  J    If  the  platina 
posed  of  equal  parts  of  tar  and  sulphur  boiled  m  l^«f  f/^!,^"J,f,^^f/f '^  we^  it  must 
solution  be  too  strone,  more  spirit  of  tar  must  be  added  to  it;  but  /^^^^u    fhe ' miZ?e 
be  concentrated   by  boiling,     Thus  being  brought  to  the  PX^vm  lif  the  asp^t 
may  be  spread  over  the  piece,  which  being  put  into  the  muffle,  will  take  the  aspect 

""^Th^^oxvde  of  Dlatina  by  means  of  which  the  silver  lustre  is  given  to  stoneware,  is  pre- 
Theox>deo  platina,  D)  mea  s  saturation  the  metal  in  an  aqua  regia 

ST,  isVaced  upon  a  sand-bath,  and  the  platina  solution  l^^-^J  P^hf  to  be  washed 
will  fall  down  in  the  form  of  the  well-known  yellow  Precuntate,  which  is  to  be  washea 
with  cold  water  till  it  is  perfectly  edulcorated,  then  dried,  and  put  up  for  use 

This  metallic  lustre  is  applied  very  smoothly  by  means  of  a  flat  camel's  hair  brush.     It 

Sc  kiln,  but  they  get  their  proper  appearance  by  being  rubbed  with  cotton. 

Platina  and  sold  lustre ;  by  other  recipes.  ■     r      ^a  ^r  o  Txf>rt«  nf 

Pa   I/u./re.-Dissolve    1   ounce  of  platinum  in  ^^^J  J^«.f.^V,<^;,"/f.  ,1^:,^^^^^^ 

muriatic  acid  and  1  part  of  nitric  acid,  with  heat  upon  a  sand-bath,  till  the  liquid  is  reduced 

Totwo  thirds  of  its  v'olume  ;    let  it  cool ;    ^-^^^  ij\«  ;;„\7jrrm^^^^^^^ 

drop  bv  drop,  with  constant  atirring,  some  distilled  tar,  nnt  1  such  a  mixture  is  p 

as  will  dve  k  good  result  in  a  trial  upon  the  ware  m  the  kiln.    If  the  l«^trej,yoo  in 

tense,  more  ta?  must  be  added  ;    if  it  be  too  weak,  the  mixture  must  be  concentrated  by 

'"tij  .X-LTs-solve  four  shillings'  worth  of  gold  in  aqua  regia  with  a  gentle  heaU 
Vol.  IL  ^  ^ 


I 


n  I 


1      i 


'414 


POTTERY. 


POTTERY. 


475 


I 


II 


To  the  solutior.,  when  cool,  add  2  grains  of  grain  tin,  which  will  immediately  dissolve. 
Prepare  a  mixture  of  half  an  ounce  of  balsam  of  sulphur  with  a  little  essence  of  turpen- 
tine, beating  them  together  till  they  assume  the  appearance  of  milk.  Pour  this  mixture 
into  the  solution  of  gold  and  tin,  drop  by  drop,  with  continual  stirring ;  and  place  the 
whole  in  a  warm  situation  for  some  time. 

]t  is  absolutely  necessary  to  apply  this  lustre  only  u  )on  an  enamel  or  glaze  which  haa 
already  passed  through  the  fire,  otherwise  the  sulphur  yould  tarnish  the  composition. 

These  lustres  are  applied  with  most  advantage  upon  chocolate  and  other  dark  grounds. 
Much  skill  is  required  in  their  firing,  and  a  perfect  acquaintance  with  the  quality  of  the 
glaze  on  which  they  are  applied. 

jin  iron  lustre  is  obtained  by  dissolving  a  bit  of  steel  or  iron  in  muriatic  acid,  mixing 
this  solution  with  the  spirit  of  tar,  and  applyino:  it  to  the  surface  of  the  ware. 

jlventurine  glaze. — Mix  a  certain  quantity  of  silver  leaf  with  the  above-described  soft 
glare,  grind  the  mixture  alontr  with  some  honey  and  boiling  wat  r,  till  the  metal  assume 
the  appearance  of  fine  particles  of  sand.  The  claze,  being  natu-  liiy  of  a  yellowish  hue, 
gives  a  t^oMen  tint  to  the  small  fragments  of  silver  disseminated  thiough  it.  Molybdena 
may  al>o  be  applied  to  produce  the  aventurine  aspect. 

The  granite-like  gfld  lustre  is  produced  by  throwing  lisfhtly  with  a  brush  a  few  drops 
of  oil  of  turpentine  upon  the  goods  already  covered  wiih  the  preparation  for  gold  lustre. 
These  cause  it  to  separate  and  appear  in  particles  resembling  the  surface  of  granite. 
When  marblina:  is  to  be  2:iven  to  stoneware,  the  lustres  of  gold,  platir  \,  and  iron  are 
used  at  once,  which  blending  in  the  fusion,  form  veins  like  those  of  marble. 

Pottery  aiii  slonewtre  of  the  Wedgcivood  color. — This  is  a  kind  of  semi- vitrified  ware, 
called  dry  bodies,  which  is  not  susceptible  of  receiving  a  superficial  glaze.  This  pottery 
is  composed  in  two  ways  :  the  first  is  with  barytic  earths,  which  act  as  fluxes  upon  the 
clays,  and  f  )rm  enamels  :  thus  the  Wediiewoo  1  j-isper  ware  is  made. 

The  white  vitrifying  pastes,  fit  for  receivinor  all  sorts  of  metallic  colors,  are  composed 
of  47  parts  of  sulphate  of  barytes,  15  of  feldspar,  26  of  Devonshire  clay,  6  of  sub^hate 
of  lime,  15  of  flints,  and  10  of  sulphate  of  stronliles.  This  composition  is  capable  of 
receiving  the  tints  of  the  metallic  oxydes  and  of  the  ochrous  metallic  earths.  Manganese 
produces  the  dark  purple  color;  gold  precipitated  by  tin,  a  rose  color  ;  antimony,  orancre; 
cobalt,  diflTcrent  shades  of  blue ;  copi)er  is  employed  for  the  browns  and  the  dead-leaf 
greens ;  nickel  ffiv-^es,  with  potash,  ereenish  colors.       » 

One  p^r  cent,  of  oxyde  of  cobalt  is  added ;  but  one  half,  or  even  one  quarter,  of  a  per 
cent,  would  be  sufficient  to  produce  the  fine  Wedsrewood  blue,  when  the  nickel  and  man- 
ganese constitute  3  per  cent.,  as  well  as  the  carbonate  of  iron.  For  the  blacks  of  this 
kind,  some  English  manufacturers  mix  black  oxyde  of  manganese  with  the  black  oxyde 
of  iron,  or  with  ochre.  Nickel  and  umber  allord  a  fine  brown.  Carbonate  of  iron,  mix- 
ed with  bole  or  terra  di  Sienna,  gives  a  beautiful  tint  to  the  paste;  as  also  manganese 
with  cobalt,  or  cobalt  with  nickel.  Antimony  produces  a  very  fine  color  when  combined 
with  the  carbonate  of  iron  in  the  proportion  of  2  per  cent.,  along  with  the  ingredients 
necessary  to  fjrm  the  above-described  vitrifying  paste. 

The  following  is  another  vitrifying  paste,  of  a  nmch  softer  nature  than  the  preceding. 
Feldspar,  30  parts;  sulphate  of  lime,  23;  silex,  17;  potter's  clay,  15;  kaolin  of  Corn- 
wall (china  clay),  15;  sulphate  of  baryta,  10.  • 

These  vitrifying  pastes  are  very  plastic,  and  may  be  worked  with  as  much  facility  as 
English  pipe-clay.  The  round  ware  is  usually  turned  upon  the  lathe.  It  may, 
however,  be  moulded,  as  the  oval  pieces  always  are.  The  more  delicate  ornaments  are 
cast  in  hollow  moulds  of  baked  clay,  by  women  and  children,  and  applied  with  remark- 
able dexterity  upon  the  turned  and  moulded  articles.  The  colored  pastes  have  such  an 
affinity  for  each  other,  that  the  detached  ornaments  may  be  applied  not  only  with  a 
little  gum  water  upon  the  convex  and  concave  forms,  but  they  may  be  made  to  adhere 
without  experiencins:  the  least  cracking  or  cliinks.  The  colored  pastes  receive  only 
one  fire,  unless  the  inner  surface  is  to  be  glazed  ;  but  a  gloss  is  given  to  the  outer  sur- 
face. The  enamel  for  the  interior  of  the  black  '^'^^direwood  ware  is  composed  of  6  parts 
of  red  leal,  1  of  sijjex,  and  2  ounces  of  manganese,  when  the  mixture  is  made  in  pounds* 
-*"ei?ht. 

The  operation  called  smearing,  consists  in  giving  an  external  lustre  to  the  un^lazed 
s,emi-viinf.ed  ware.  The  articles  do  not  in  this  way  receive  any  immersion, 
nor  even  the  aid  of  the  brush  or  pencil  of  the  artist ;  but  they  require  a  second  fire. 
The  saggers  are  coated  with  the  salt  glaze  already  described.  These  cases,  or  saggers, 
communicate  by  reverberation  the  lustre  so  remarkable  on  the  surface  of  the  English 
stoneware  ;  which  one  misht  suppose  to  be  the  result  of  the  glaze  tub,  or  of  the  brush. 
Occasionally  also  a  very  fusible  composition  is  thrown  upon  the  inner  surface  of  the 
muflSe,  and  5  or  6  pieces  called  refractories  are  set  in  the  middle  of  it,  coated  with  the 
same  composition.     The  intensity  of  the  heat  converts  the  flux  into  vapor;  a  part  of 

6P 


this  is  condensed  upon  the  surfaces  of  the  contiguous  articles ;  so  as  to  give  them  the  de- 

tired  brilliancy.  «  - , ,  «    r    -i         « i  i  ^r 

Mortar  body  is  a  paste  composed  of  6  parts  of  clay,  3  of  feldspar,  2  of  silex,  and  1  of 

^  While^and  yellow  fisures  upon  dark-colored  grounds  are  a  good  deal  employed.  Tc 
produce  yellow  impressions  upon  brown  stoneware,  ochre  is  ground  up  with  a  small 
quantity  of  antimony.  The  flux  consists  of  flint  glass  and  flints  m  equal  weights. 
The  composition  for  white  desi-ns  is  made  by  grinding  silex  up  with  that  flux,  and  print- 
ing it  on,  as  for  blue  colors,  upon  brown  or  other  colored  stoneware,  which  shows  od  the 

li^'ht  hifs 

"EngUsh  porcelain  or  china.-Mosi  of  this  belongs  to  the  class  called  tender  or  soft  por- 
celain by  the  French  and  German  manufacturers.  It  is  not,  therefore,  composed  simply 
of  kaolin  and  petuntse.  The  English  china  is  e:enerally  baked  at  a  much  lower  heat  than 
that  of  Sivres,  Dresden,  and  Berlin;  and  it  is  covered  with  a  mere  glass  Being  inanu- 
factured  upon  a  prodigious  scale,  with  great  economy  and  certainty,  and  little  expenditure 
of  fuel,  it  is  sold  at  a  very  moderate  price  compared  with  the  foreign  porcelain,  and  in 
external  appearance  is  now  not  much  inferior.  rr.u-    •  a 

Some  of  the  En-lish  porcelain  has  been  called  ironstone  china.  This  is  composed  usu- 
ally  of  60  parts  of  Cornish  stone,  40  of  china  clay,  and  2  of  A^t  glass  ;  or  of  42  of  the 
feldspar,  the  same  quantity  of  clay,  10  parts  of  flints  ground,  and  8  of  Aint  glass 

The  ^laze  for  the  first  composition  is  made  with  20  parts  of  feldspar,  15  of  flints,  6  of 
red  leal,  and  5  of  soda,  which  are  fritted  together;  with  44  parts  of  the  frit,  22  parts  of 
flint  slass,  and  15  parts  of  white  lead,  are  ground.  rn-  ♦    i  c     qa  «r  foUc««r 

The  glaze  for  the  second  composition  is  formed  of  8  parts  of  flint  glass,  36  of  feldspar, 
40ofwhitelead,  and  20  of  silex  (ground  flints.)  .  .       r     .,  i  •     k- 

The  En-lish  manufacturers  employ  three  sorts  of  compositions  for  the  porcelain  bis- 
cuit; namely,  two  compositions  not  fritted;  one  of  them  for  the  ordinary  table  sernce; 
another  for  the  dessert  service  and  tea  dishes;  the  third,  which  is  fritted  corresponds  to 
the  paste  used  in  France  for  sculpture ;  and  with  it  all  delicate  kinds  of  ornaments  are 
made.  


Ground  flints     ■ 
Calcined  bones 
China  clay 
Clav 


First  composition. 


75 

180 

40 

70 


Second  compisition.  I  Third  composition. 


Granite 


66 

100 

96 

80 


Lynn  sand  150 

-  300 

-  100 
Potash    -       10 


The  ^laze  for  the  first  two  of  the  preceding  compositions  consists  of,  feldspar  45,  flmls 
9,  borax  21,  flint  class  20,  nickel  4.  After  fritting  that  mixture,  add  12  parts  of  red 
lead  For  the  third  composition,  which  is  the  most  fusible,  the  glaze  must  receive  12 
parts  of  ground  flints,  instead  of  9 ;  and  there  should  be  only  15  parts  of  borax,  instead 
of  21. 

PLAN  OF  AN  ENGLISH  POTTERY. 

A  Stoneware  manufactory  should  be  placed  by  the  side  of  a  canal  or  navigable  river, 
because  the  articles  manufa'ctured  do  not  well  bear  land  carriage. 

A  Slaff'ordshire  pottery  is  usually  built  as  a  quadrangle,  each  side  being  about  100  feel 
lon<'  the  walls  10  feet  hieh,  and  the  ridge  of  the  roof  5  feet  more.  The  base  of  the  edi- 
fice'^consists  of  a  bed  of  bricks,  18  inches  high,  and  16  inches  thick;  upon  which  a  mud 
wall  in  a  wooden  frame,  called  pise,  is  raised.  Cellars  are  formed  m  front  of  the  build- 
ings, as  depots  for  the  pastes  prepared  in  the  establishment.  The  wall  of  the  yard  or 
court  is  9  feet  high,  aa    18  inches  thick.  ^ 

ii'tg.  1156  A,  is  the  entrance  door ;  b,  the  porter's  lodge;  c,  a  particular  warehousej 
D,  workshop  of  the  plaster-moulder-  -.,  me  clay  depot;  f,  f,  large  gates,  6  feet  8  inches 
hi<'h  ;  G,  the  winter  evaporation  stove  ;  h,  the  shop  for  sifting  the  paste  liquors ;  i,  sheds 
for  the  paste  liquor  tubs;  J,  paste  liquor  pits;  k,  workshop  for  the  moulder  of  hcllow 
ware  ;  l,  ditto  of  the  dish  or  plate  moulder  ;  m,  the  plate  drying-stove ;  n,  workshop  oi  the 
biscuit-printers;  o,  ditto  of  the  biscuit,  with  o',  a  long  window ;  p,  passage  leading  to  the 
paste  liquor  pits  ;  q,  biscuit  warehouse;  r,  place  where  the  biscuit  is  cleaned  as  it  comes 
GUI  of  the  biscuit-kilns,  s,  s ;  t,  t,  enamel  or  glaze-kilns  ;  u,  long  passage  ;  v,  space  left  for 
supplementarv  workshops  ;  x  space  appointed  as  a  depot  for  the  sagger  fire-clay,  as  also 
for  making  the  saggers;  z,  ihe  workshop  for  applying  the  glaze  liquor  to  the  biscuits ; 
a  apartment  for  cleaning  the  glazed  ware ;  b,  b,  pumps ;  c,  basin  ;  d,  muffies ;  «,  ware- 
house for  the  finished  stoneware;  /,  that  of  the  glazed  goods ;  g,  g,  another  warehouse , 
k  a  lar^e  space  for  the  smith's  forge,  carpenter's  shop,  packing  room,  depot  of  clays, 
sL<r,Ters "  Jfec.     The  packing  and  loading  of  the  goods  are  performed  in  front  of  iLe 


I'ii 


I 


III 


476 


POTTERY. 


warehouse,  which  has  two  outlets,  in  order  to  facilitate  the  work ;  t,  a  passage  to  the 
court  or  yard ;  Z,  a  space  for  the  wooden  sheds  for  keeping  hay,  clay,  and  other  niiscel- 
1156  


laneous  articles  ;  th,  room  for  putting  the  biscuit  into  the  saggers  ;  m',  a  long  window ; 
n,  workshop  with  lathes  and  fly-wheels  ;  o,  drying-room ;  p,  room  for  mounting  or  fur- 
nishing the  pieces  ;  q,  repairing-room  ;  r,  dr}ing-room  of  the  goods  roughly  turned  ;  », 
rough  turning  or  blocking-out  room;  /,  room  for  beating  the  paste  or  dough;  u, 
counting-house. 

The  declared  value  of  the  earthenware  exported  in  1836,  was  837,774Z. ;  in  1837, 
558,682/. 

There  are  from  33,000  to  35,000  tons  of  clay  exported  annually  from  Poole,  in  Dor- 
setshire, to  the  English  and  Scotch  potteries.     A  good  deal  of  clay  is  also  sent  from  Dev 
onshire  and  Cornwall. 

The  Spanish  alcarazzas,  or  cooling  vessels,  are  made  porous,  to  favor  the  exudation 
of  water  through  them,  and  maintain  a  constantly  moist  evaporating  surface,  Lasteyrie 
says,  that  granular  sea  salt  is  an  ingredient  of  the  paste  of  the  Spanish  alcarazzas;  which 
being  expelled  partly  by  the  heat  of  the  baking,  and  partly  by  the  subsequent  watery  per- 
colation, leaves  the  body  very  open.  The  biscuit  should  be  charged  with  a  considerable 
proportion  of  sand,  and  very  moderately  fired. 

OF   PORCFXAIN. 

Porcelain  is  a  kind  of  pottery  ware  whose  paste  is  fine  grained,  compact,  very  hard, 
and  faintly  translucid ;  and  whose  biscuit  softens  slightly  in  the  kiln.  Its  ordinary  white- 
r.3ss  cannot  form  a  definite  character,  since  there  are  porcelain  pastes  variously  colored. 
There  are  two  species  of  porcelain,  very  difl'erent  in  their  nature,  the  essential  properties 
of  which  it  is  of  consequence  to  establish ;  the  one  is  called  hard,  and  the  other  tender ; 
important  distinctions,  the  neglect  of  which  has  introduced  great  confusion  into  many 
treatises  on  this  elegant  manufacture. 

Hard  porcelain  is  essentially  composed,  first,  of  a  natural  clay  containing  some  silica, 
infusible,  and  preserving  its  whiteness  in  a  strong  heat ;  this  is  almost  always  a  true 
kaolin  ;  secondly,  of  a  flux,  consisting  of  silica  and  lime,  composing  a  quartzose  feldspar 
rock,  called  pe-tun-tse.  The  glaze  of  this  porcelain,  likewise  earthy,  admits  of  no  metaliie 
substance  or  alkali. 


POTTERY. 


477 


Tender  porcelain,  styled  also  vitreous  porcelain,  has  no  relation  with  the  preceding  ii 
its  composition  ;  it  always  consists  of  a  vitreous  frit,  rendered  opaque  and  less  fusible  by 
the  addition  of  a  calcareous  or  marly  clay.  Its  glaze  is  an  artificial  glass  or  crystal,  into 
which  silica,  alkalis,  and  lead  enter. 

This  porcelain  has  a  more  vitreous  biscuit,  more  transparent,  a  little  less  hanl,  and  iCsa 
fragile,  but  much  more  fusible  than  that  of  the  hard  porcelain.  Its  glaze  is  more  glossy, 
more  transparent,  a  little  less  white,  much  tenderer,  and  more  fusible. 

The  biscuit  of  the  hard  porcelain  made  at  the  French  national  manufactory  of  Sevres 
is  generally  composed  of  a  kaolin  clay,  and  of  a  decomposed  feldspar  rock ;  analogous  to  the 
china  clay  of  Cornwall,  and  Cornish  stone.  Both  of  the  above  French  materials  come  from 
Saint  Yriex-la-perche,  near  Limoges. 

After  many  experiments,  the  following  composition  has  been  adopted  for  the  service 
paste  of  the  royal  manufactory  of  Sevres ;  that  is,  for  all  the  ware  which  is  to  be  glazed; 
silica,  59  ;  alumina,  35-2  ;  potash,  2-2  ;  lime,  3-3.  The  conditions  of  such  a  compound 
are  pretty  nearly  fulfilled  by  taking  from  63  to  70  of  the  washed  kaolin  or  china  clay, 
22  to  15  ot  the  feldspar,  nearly  10  of  flint  powder,  and  about  5  of  chalk.  The  glaze  is 
composed  solely  of  solid  felds'par,  calcined,  crushed,  and  then  ground  fine  at  the  mill. 
This  rock  pretty  uniformly   consists   of    silica    73,  alumina    16-2,   potash    8-4,  and 

The  kaolin  is  washed  at  the  pit,  and  sent  in  this  state  to  Sevres,  under  the  name  of 
decanted  earth.  At  the  manufactory  it  is  washed  and  elutriated  with  care ;  and  its  slip 
is  passed  through  fine  sieves.  This  forms  the  plastic,  infusible,  and  opaque  ingredient 
to  which  the  substance  must  be  added  which  gives  it  a  certain  degree  of  fusibility  and 
semi-transparency.  The  feldspar  rock  used  for  this  purpose,  should  contain  neither  dark 
mica  nor  iron,  either  as  an  oxyde  or  sulphuret.  It  is  calcined  to  make  it  crushable,  under 
stamp-pestles  driven  by  machinery,  then  ground  fine  in  hornstone  mills,  as  repre- 
sented in  /g«.  1154,  1155,  1156,  1157.  This  pulverulent  matter,  being  diffused  through 
«rater,  is  mixed  in  certain  proportions,  regulated  by  its  quality,  with  the  argillaceous 
»lip.  The  mixture  is  deprived  of  the  chief  part  of  its  water  in  shallow  plaster  pans 
without  heat ;  and  the  resulting  paste  is  set  aside  to  ripen,  in  damp  cellars,  for  many 
months. 

When  wanted  for  use,  it  is  placed  in  hemispherical  pans  of  plaster,  which  absorb  the 
redundant  moisture ;  after  which,  it  is  divided  into  small  lumps,  and  completely  dried. 
It  is  next  pulverized,  moistened  a  little,  and  laid  on  a  floor,  and  trodden  upon  by  a  work- 
man marching  over  it  with  bare  feet  in  every  direction ;  the  parings  and  fragments  of  soft 
moulded  articles  being  intermixed,  which  improve  the  plasticity  of  the  whole.  When  suffi- 
ciently tramped,  it  is  made  up  into  masses  of  the  size  of  a  man's  head,  and  kept  damp  till 
required. 

The  dough  is  now  in  a  state  fit  for  the  potter's  lathe ;  but  it  is  much  less  plastic  than 
stoneware  paste,  and  is  more  difficult  to  fashion  into  the  various  articles ;  and  hence  one 
cause  of  the  higher  price  of  porcelain. 

The  round  plates  and  dishes  are  shaped  on  plaster  moulds ;  but  sometimes  the  paste 
is  laid  on  as  a  crust,  and  at  others  it  is  turned  into  shape  on  the  lathe.  When  a  crust 
is  to  be  made,  a  moistened  sheep-skin  is  spread  on  a  marble  table ;  and  over  this  the 
doush  is  extended  with  a  rolling-pin  supported  on  two  guide-rules.  The  crust  is  thea 
transferred  over  the  plaster  mould,  by  lifting  it  upon  the  skin;  for  it  wants  tenacity  to 
bear  raising  by  itself.  When  the  piece  is  to  be  fashioned  on  the  lathe,  a  lump  of  the 
dough  is  thrown  on  the  centre  of  the  horizontal  wooden  disc,  and  turned  into  form  as 
directed  in  treating  of  stoneware,  only  it  must  be  left  much  thicker  than  in  its  finished 
state.  After  it  dries  to  a  certain  degree  on  the  plaster  mould,  the  workman  replaces  it  on 
the  lathe,  by  moistening  it  on  its  base  with  a  wet  sponge,  and  finishes  its  form  with  an 
iron  tool.  A  good  workman  at  Sevres  makes  no  more  than  from  15  to  20  porcelain  plates 
in  a  day ;  whereas  an  English  potter,  with  two  boys,  makes  from  1000  to  1200  plates  of 
stoneware  in  the  same  time.  The  pieces  which  are  not  round,  are  shaped  in  plaster  moulds, 
and  finished  by  hand.  When  the  articles  are  very  large,  as  wash-hand  basins,  salads,  &C., 
a  flat  cake  is  spread  above  a  skin  on  the  marble  slab,  which  is  then  applied  to  the  mould 
with  the  sponge,  as  for  plates ;  and  they  are  finished  by  hand. 

The  projecting  pieces,  such  as  handles,  beaks,  spouts,  and  ornaments,  are  moulded 
and  adjusted  separately;  and  are  cemented  to  the  bodies  of  china-ware  with  slip,  or 
porcelain  dough  thinned  with  water.  In  fact,  the  mechanical  processes  with  porcelain 
and  the  finer  stoneware  are  substantially  the  same ;  only  they  require  more  time  and 
greater  nicety.  The  least  defect  in  the  fabrication,  the  smallest  bit  added,  an  unequal 
pressure,  the  cracks  of  the  moulds,  although  well  repaired,  and  seemingly  effaced  in  the 
clay  shape,  re-appear  after  it  is  baked.  The  articles  should  be  allowed  to  dry  very  slow- 
ly ;  if  hurried  but  a  little,  they  are  liable  to  be  spoiled.    When  quite  dry,  they  are  taken 

to  the  kiln. 
The  kiln  for  hard  porcelain  at  Sevres,  is  a  kind  of  tower  in  two  flats,  constructed  of 


\ 

i 


f:     t 


h  '• 


478 


POTTERY. 


POTTERY. 


4*79 


fire-hricks ;  and  resembles,  in  other  respects,  the  stoneware  kiln  already  figured  and 
described.  The  fuel  is  young  aspin  wood,  vei7  dry,  and  cleft  very  small ;  it  is  put  into 
the  apertures  of  the  four  outside  furnaces  or  fire-mouths,  which  discharge  their  flaofie 
into  the  inside  of  the  kiln;  each  floor  being  closed  in  above,  by  a  dome  pierced  with 
holes.  The  whole  is  covered  in  by  a  roof  with  an  open  passage,  placed  at  a  proper  dis- 
tance from  the  uppermost  dome.  There  is,  therefore,  no  chimney  proper  so  called.  See 
Stonk,  artificial. 

The  raw  pieces  are  put  into  the  upper  floor  of  the  kiln  ;  where  they  receive  a  heat  of 
about  the  (iOth  de?ree  of  Wedsewood's  pyrometer,  and  a  commencement  of  baking 
which,  Avithout  altering  their  shape,  or  causin?  a  perceptible  shrinking  of  their  bulk, 
makes  them  completely  dry,  and  gives  them  sufficient  solidity  to  bear  handling.  By  this 
preliminary  baking,  the  clay  loses  its  property  of  forming  a  paste  with  water ;  and  the 
pieces  become  fit  for  receiving  the  glazing  coat,  as  they  may  be  dipped  in  water  without 
risk  of  breakage. 

The  ulaze  of  hard  porcelain  is  a  feldspar  rock  ;  this  being  ground  to  a  very  fiife  pow- 
der, is  worked  into  a  paste  with  water  mingled  with  a  little  vinegar.  All  the  articles  arc 
dipped  into  this  milky  liquid  for  an  instant;  and  as  they  are  very  porous,  they  absorb 
the  water  jjreedily,  whereby  a  layer  of  the  feldspar  glaze  is  deposited  on  their  surface,  in 
a  nearly  dry  state,  as  soon  as  they  are  lifted  out.  Glaze-pap  is  afterwards  applied  with 
a  hair  brush  to  the  projecting  edges,  or  any  points  where  it  had  not  taken  ;  and  the  pow- 
der is  then  removed  from  the  part  on  which  the  article  is  to  stand,  lest  it  should  get 
fi;ted  to  its  support  in  the  fire.  After  these  operations  it  is  replaced  in  the  kiln,  to  be 
completely  baked. 

The  articles  are  put  into  saggers,  like  those  of  fine  stoneware  ;  and  this  operation  is 
one  of  the  most  delicate  and  expensive  in  the  manufacture  of  porcelain.  The  saggers 
are  made  of  the  plastic  or  potter's  clay  of  Abondant,  to  which  about  a  third  part  of  cement 
of  broken  saggers  has  been  added. 

As  the  porcelain  pieces  soften  somewhat  in  the  fire,  they  cannot  be  set  above  each 
other,  even  were  they  free  from  glaze ;  for  the  same  reason,  they  cannot  be  baked  on 
tripods,  several  of  them  beins  in  one  case,  as  is  done  with  stoneware.  Every  i)iece  of 
porcelain  requires  a  sasgcr  for  itself.  They  must,  moreover,  be  placed  on  a  perfectly 
flat  surfiice,  because  in  softening  they  would  be  apt  to  conform  to  the  irregularities  of  a 
rough  one.  When  therefore  any  piece,  a  soup  plate  fqr  example,  is  to  be  saggered,  there 
is  laid  on  the  bottom  of  the  case  a  perfectly  true  disc  or  round  cake  of  stoneware,  made 
of  the  sasrger  material,  and  it  is  secured  in  its  place  on  three  small  props  of  a  clay-lute, 
consisting  of  pottei-'s  clay  mixed  with  a  great  deal  of  sand.  When  the  cake  is  carefully 
levelled,  it  is  moistened,  and  dusted  over  with  sand,  or  coated  with  a  film  of  fire-clay  slip, 
and  the  porcelain  is  carefully  set  on  it.  The  sand  or  fire-clay  hinders  it  from  sticking  to 
the  cake.     Several  small  articles  may  be  set  on  the  same  cake,  provided  they  do  not  touch 

one  another. 

The  saggers  containing  the  pieces  thus  arranged,  are  piled  up  in  the  kiln  over  each 
other,  in  the  columnar  form,  till  the  whole  space  be  occupied  ;  leaving  very  moderate  in- 
tervals between  the  columns  to  favor  the  draught  of  the  fires.  The  whole  being  arranged 
with  these  precautions,  and  several  others,  too  minute  to  be  specified  here,  the  door  of 
the  kiln  is  built  up  with  3  rows  of  bricks,  leaving  merely  an  opening  8  inches  square, 
through  which  there  is  access  to  a  sagger  with  the  nearest  side  cut  oflT.  In  this  sagger 
are  put  fragment-  of  porcelain  intended  to  be  withdrawn  from  time  to  time,  in  order  to 
judge  of  ihe  progrej^s  of  the  baking.  These  are  called  lime-pieces  or  watches  (won/res). 
This  opening  into  the  watches  is  closed  by  a  stopper  of  stoneware. 

The  firing  besins  by  throwing  into  the  furnace-mouths  some  pretty  larse  pieces  of 
white  wood,  and  the  heat  is  maintained  for  about  15  hours,  gradually  raising  it  by  the 
addition  of  a  larger  quantity  of  the  wood,  till  at  the  end  of  that  period  the  kiln  has  a 
cherry-red  color  within.  The  heat  is  now  greatly  increased  by  the  operation  termed 
covering  ihe  fire.  Instead  of  throwing  billets  vertically  into  the  four  furnaces,  there  is 
placed  horizontally  on  the  openings  of  these  furnaces,  aspin  wood  of  a  sound  texture, 
cleft  small,  laid  in  a  sloping  position.  The  brisk  and  long  flame  which  it  yields  dips 
into  the  tunnels,  penetrates  the  kiln,  and  circulates  round  the  sagger-piles.  The  heat 
augments  rapidly,  and,  at  the  end  of  13  or  15  hours  of  this  firing,  the  interior  of  the 
kiln  is  so  white,  that  the  watches  can  hardly  be  distinguished.  The  draught,  indeed,  is 
so  rapid  at  this  time,  that  one  may  place  his  hand  on  the  slope  of  the  wood  without  feel- 
ing incommoded  by  the  heat.  Everything  is  consumed,  no  small  charcoal  re- 
mains, smoke  is  no  longer  produced,  and  even  the  wood-ash  is  dissipated.  It  is  obvious 
that  the  kiln  and  the  saggers  must  be  composed  of  a  very  refractory  clay,  in  order  to  re- 
sist such  a  tire.  The  heat  in  the  Sevres  kilns  mounts  so  high  as  the  134th  degree  of 
Wedgewood. 

At  the  end  of  15  or  20  hours  of  the  great  fire,  that  is,  after  from  30  to  36  hours* 
firing,  the  porcelain  is  baked;    as  is  ascertained  by  taking  out  and   examining  the 


1 1-. 
It . 


watches.  The  kiln  is  suffered  to  cool  during  3  or  4  dayj,  and  is  then  opened  and  dia- 
charged.  The  sand  strewed  on  the  cakes,  to  prevent  the  adhesion  of  the  articles  to  them, 
gets  attached  to  their  sole,  and  is  removed  by  friction  with  a  hard  sandstone  ;  an  opera- 
tion which  one  woman  can  perform  for  a  whole  kiln  in  less  than  10  days ;  and  is  the 
last  apidied  to  hard  porcelain,  unless  it  needs  to  be  returned  into  the  hot  kiln  to  have 
some  defects  repaired. 

The  materials  of  fine  porcelain  are  very  rare ;  and  there  would  be  no  advantage  in 
making  a  gray-white  porcelain  with  coarser  and  somewhat  cheaper  materials^  for 
the  other  sources  of  expense  above  detailed,  and  which  are  of  most  consequence,  would 
still  exist ;  while  the  porcelain,  losing  much  of  its  brightness,  would  lose  the  main  part 
of  its  value. 

Its  pap  or  dough,  which  requires  tedious  grinding  and  manipulation,  is  also  more 
difficult  to  work  into  shapes,  in  the  ratio  of  80  to  1,  compared  to  fine  stoneware.  Each 
porcelain  plate  requires  a  separate  sagger;  so  that  12  occupy  in  the  kiln  a  space  suffi- 
cient for  at  least  38  stoneware  plates.  The  tempeiature  of  a  hard  porcelain  kiln  being 
very  high,  involves  a  proportionate  consumption  of  fuel  and  waste  of  saggers.  With 
40  sferes  (cubic  metres)  of  wood,  12,000  stoneware  plates  may  be  completely  fired,  both 
in  the  biscuit  and  glaze  kilns;  while  the  same  quantity  of  wood  would  bake  at  most  only 
1000  plates  of  porcelain. 

To  these  causes  of  high  price,  which  are  constant  and  essential,  we  ought  to  add  the 
numerous  accidents  to  which  porcelain  is  exposed  at  every  step  of  its  pre]=aralion,  and 
particularly  in  the  kiln;    these  accidents  damage  upwards  of  one  third  of  the  pieces, 
and   frequently  more,  when  articles  of  singular  form  and  large  dimensions  are  ad 
ventured. 

The  best  English  porcelain  is  made  from  a  mixture  of  the  Cornish  kaolin  (called  china 
clay),  ground  flints,  ground  Cornish  stone,  and  calcined  bones  in  powder,  or  bone-ash,  be- 
sides some  other  materials,  according  to  the  fancy  of  the  manufacturers.  A  liquid  pap 
is  made  with  these  materials,  compounded  in  certain  proportions,  and  diluted  with  water. 
The  fluid  part  is  then  withdrawn  by  the  absorbent  action  of  dry  stucco  basins  or  pans. 
The  dough,  brought  to  a  proper  stiffness,  and  perfectly  worked  and  kneaded  on  the  prin- 
ciples detailed  above,  is  fashioned  on  the  lathe,  by  the  hands  of  modellers,  or  by  pressure 
in  moulds.  The  pieces  are  then  baked  to  the  state  of  biscuit  in  a  kiln,  being  enclosed, 
of  course,  in  saggers. 

This  biscuit  has  the  aspect  of  white  sugar,  and  being  very  porous,  must  receive  a 
vitreous  coating.  The  glaze  consists  of  ground  feldspar  or  Cornish  stone.  Into  this, 
diffused  in  water,  along  with  a  little  flmt-powder  and  potash,  the  biscuit  ware  is  dipped, 
as  already  described,  under  stoneware.  The  pieces  are  then  fired  in  the  glaze-kiln,  care 
being  taken,  before  putting  them  into  their  saggers,  to  remove  the  glaze  powder  from  their 
bottom  parts,  to  prevent  their  adhesion  to  the  fire-clay  vessel. 

TENDER  PORCELAIN, 

Tender  porcelain,  or  soft  china-ware,  is  made  with  a  vitreous  frit,  rendered  less  fusible 
and  opaque  by  an  addition  of  white  marl  or  bone-ash.  The  frit  is,  therefore,  first  pre- 
pared. This,  at  Sevres,  is  a  composition,  made  with  some  nitre,  a  little  sea  salt,  Alicant 
barilla,  alum,  gypsum,  and  much  silicious  sand  or  ground  flints.  That  mixture  is  sub- 
jected to  an  incipient  pasty  fusion  in  a  furnace,  where  it  is  stirred  about  to  blend  the 
materials  well ;  and  thus  a  very  white  spongy  fi  it  is  obtained.  It  is  pulverized,  and  to 
every  three  parts  of  it,  one  of  the  white  marl  of  Argenteuil  is  added ;  and  when  the  whole 
are  well  ground,  and  intimately  mixed,  the  paste  of  tender  porcelain  is  formed. 

As  this  paste  has  no  tenacity,  it  cannot  bear  working  till  a  mucilage  of  gum  or  black 
soap  be  added,  which  gives  it  a  kind  of  plasticity,  though  even  then  it  willnot  bear  the 
lathe.  Hence  it  must  be  fashioned  in  the  press,  between  two  moulds  of  plaster.  The 
pieces  are  left  thicke-  than  they  should  be ;  and  when  dried,  are  finished  on  the  lathe 
with  iron  tools. 

In  this  state  they  are  baKed,  without  any  glaze  being  applied ;  but  as  this  porcelain 
fioftens  far  more  during  the  baking  than  the  hard  porcelain,  it  needs  to  be  supported  on 
every  side.  This  is  done  by  baking  on  earthen  moulds  all  such  pieces  as  can  be  trtated 
In  this  way,  namely,  plates,  saucers,  &c.  The  pieces  are  reversed  on  these  moulds,  and 
undergo  their  shrinkage  without  losing  their  form.  Beneath  other  articles,  supports  of 
a  like  paste  are  laid,  which  suffer  in  baking  the  same  contraction  as  the  articles,  and  of 
course  can  serve  only  once.  In  this  operation  saggers  are  used,  in  which  the  pieces  and 
their  supports  are  fired. 

The  kiln  for  the  tender  porcelain  at  Sevres  is  absolutely  similar  to  that  for  the 
common  stoneware  ;  but  it  has  two  floors  ;  and  while  the  biscuit  is  baked  in  the  lower 
story,  the  glaze  is  fused  in  the  upper  one;  which  causes  considerable  economy  of 
fueL  The  glaze  of  soft  porcelain  is  a  species  of  glass  or  crystal  prepared  on  purpose. 
It  is  composed  of  flint,  silicious  sand,  a  little  potash  or  soda,  and  about  two  fifth  parts 


! 


\ 


480 


POTTERY. 


of  lead  oxyde.  This  mixture  is  melted  in  crucibles  or  pots  beneath  the  kiln.  The 
resulting  glass  is  ground  fine,  and  difl'used  through  water  mixed  with  a  little  vinegar  to 
the  consistence  of  cream.  All  the  pieces  of  biscuit  are  covered  with  this  glazy  matter, 
by  pouring  this  slip  over  them,  since  their  substance  is  not  absorbent  enough  to  take  it 

on  by  immersion.  . 

The  pieces  are  encased  once  more  each  in  a  separate  sagger,  but  without  any  supports; 
for  the  heat  of  the  upper  floor  of  the  kiln,  though  adequate  to  melt  the  glaze,  is  not  strong 
enough  to  soften  the  biscuit.  But  as  this  first  vitreous  coat  is  not  very  equal,  a  second 
one  is  applied,  and  the  pieces  are  returned  to  the  kiln  for  the  third  time.  See  Stone,  ar- 
tificial, for  a  view  of  this  kiln,  r  x,    A     '* 

The  manufacture  of  soft  porcelain  is  longer  and  more  difficult  than  that  of  hard ;  lis 
biscuit  is  dearer,  althoush  the  raw  materials  may  be  found  even'where  ;  and  it  furnishes 
also  more  refuse.  Many  of  the  pieces  split  asunder,  receive  fissures,  or  become  detormed 
in  the  biscuit-kiln,  in  spite  of  the  supports;  and  this  vitreous  porcelain,  moreover,  is  al- 
ways  yellower,  more  transparent,  and  incapable  of  bearing  rapid  transitions  of  tempera- 
ture,  so  that  even  the  heat  of  boiling  water  frequently  cracks  it.  It  possesses  some  ad- 
vantages  as  to  painting,  and  may  be  made  so  gaudy  and  brilliant  in  its  decorations,  as  to 
captivate  the  vulgar  eye. 

DESCRIPTION  OF  THE  PORCELAIN  MILL. 

1.  The  following  figures  of  a  feldspar  and  flint  mill  are  taken  from  plans  of  apparatus 
lately  constructed  by  Mr.  Hall  of  Darlford,  and  erected  by  him  in  the  royal  manufactory 
of  Sevres.  There  are  two  similar  sets  of  apparatus,^?.  900,  which  may  be  employed  to- 
eether  or  in  succession  ;  composed  each  of  an  elevated  tub  a,  and  of  three  successive  vats 

1157 


il^^rteJ;^'!'-;,,:,^ 


of  reception  a',  and  two  behind  it,  whose  top  edges  are  upon  a  lower  level  than  the  bottom 
of  the  ca^ks  a,  a,  to  allow  of  the  liquid  running  out  of  them  with  a  sufficient  slope.     A 
proper  charge  of  kaolin  is  first  put  into  the  cask  a,  then  water  is  gradually  run  into  it 
by  the  gutter  adapted  to  the  stopcock  a,  after  which  the  mixture  is  agitated  powerfully 
in  eveiT  direction  by  hand  with  the  stirring-bar,  which  is  hung  withm  a  hole  in  the 
ceilin<'  and  has  at  its  upper  end  a  small  tin-plate  funnel  to  prevent  dirt  or  rust  from 
dropping  down  into  the  clay.     The  stirrer  may  be  raised  or  lowered  so  as  to  touch  any 
part  of  the  cask.    The  semi-fluid  mass  is  left  to  settle  for  a  few  minutes,  and  then  the 
finer  argillaceous  pap  is  run  off  by  the  stopcock  a',  placed  a  little  above  the  gritty 
deposite!  into  the  zinc  pipe  which  conveys  it  into  one  of  the  tubs  a  ;  but  as  this  semi- 
liquid  matter  may  still  contain  some  granular  substances,  it  must  be  passed  through  a 
sieve  before  it  is  admitted  into  the  tub.    There  is,  therefore,  at  the  spot  upon  the  tub  where 
the  zinc  pipe  terminates,  a  wire-cloth  sieve,  of  an  extremely  close  texture,  to  receive  the 
liquid  paste.     This  sieve  is  shaken  upon  its  support,  in  order  to  make  it  discharge  the 
washed  argillaceous  kaolin.     After  the  clay  has  subsided,  the  water  is  drawn  off  from  its 
surface  by  a  zinc  syphon.     The  vats  a'  have  covers,  to  protect  their  contents  from  dust. 
In  the  pottery  factories  of  England,  the  agitation  is  produced  by  machiner>',  instead  ol  the 
hand.     A  vertical  shaft,  with  horizontal  or  oblique  paddles,  is  made  to  revolve  in  the  vaU 

for  this  purpose.  ,         ...         •  j-  _ 

The  small  triturating  tpAU  is  represented  in  fig.  1158,  There  are  three  similar  fi'^ding- 
tubs  on  the  same  line.  The  details  of  the  construction  are  shown  in  figs.  11^9,  60. 
where  it  is  seen  to  consist  principally  of  a  revolving  millstone  a  (yig.  1169)  of  a  last 
or  sleeper  millstone  b',  and  of  a  vat  c,  hooped  with  iron,  with  its  top  raised  above  the 
upper  millstone.  The  lower  block  of  hornstone  rests  upon  a  very  firm  basis,  6  ;  il 
is  surrounded  immediately  by  the  strong  wooden  circle  c,  which  slopes  out  funnel-wise 
above,  in  order  to  throw  back  the  earthy  matters  as  they  are  pushed  up  by  the  attrition 


POTTERY. 


481 


1159 


•f  the  stones.  That  piece  is  hollowed  out,  partially  to  admit  the  key  c,  opposite  to 
which  is  the  faucet  and  spigot  c',  for  emptying  the  tub.  When  one  operation  is  com- 
pleted, the  key  c  is  lifted  out  by  means  of  a 
peg  put  into  the  holes  at  its  top ;  the  spigot  it 
then  drawn,  and  the  thin  paste  is  run  out  into  vats. 
The  upper  grindstone,  b  d,  like  the  lower  one,  is 
about  two  feet  in  diameter,  and  must  be  cut  in  a 
peculiar  manner.  At  first  there  is  scooped  out 
a  hollowing  in  the  form  of  a  sector,  denoted  b) 
d  ^fyfig'^l^O ;  the  arc  d/ is  about  one  sixth  of 
the  circumference,  so  that  the  vacuity  of  the 
turning  grindstone  is  one  sixth  of  its  surface ; 
moreover,  the  stone  must  be  channelled,  in  order 
to  grind  or  crush  the  hard  gritty  substances.  For 
this  purpose,  a  wedge-shaped  groove  d  e  g,  about 
an  inch  and  a  quarter  deep,  is  made  on  its  under 
face,  whereby  the  stone,  as  it  turns  in  the  direc- 


wm/mm/M. 

tion  indicated  by  the  arrow,  acts  with  this  inclined  plane  upon  all  the  particles  in  its 
course,  crushing  them  and  forcing  them  in  between  the  stones,  till  they  be  tritur\ted  to 
an  impalpable  powder.  When  the  grindstone  wears  unequally  on  its  lower  surface,  it  ii 
useful  to  trace  upon  it  little  furrows,  proceeding  from  the  centre  to  the  circumference, 
like  those  shown  by  the  dotted  lines  c'  t".  It  must,  moreover,  be  indented  with  rough 
points  by  the  hammer. 

The  turning  horn-stone  block  is  set  in  motion  by  the  vertical  shaft  h,  which  is  fixed 
by  the  clamp-iron  cross  i  to  the  top  of  the  stone.  When  the  stone  is  new,  its  thickness 
is  about  14  inches,  and  it  is  made  to  answer  for  grinding  till  it  be  reduced  to  about 
8  inches,  by  lowering  the  clamp  i  upon  the  shaft,  so  that  it  may  continue  to  keep  its 
hold  of  the  stone.  The  manner  in  which  the  grindstones  are  turned,  is  obvious  from 
inspection  of  ^g.  1168  where  the  horizontal  axis  l,  which  receives  its  impulsion  from 
the  great  water-wheel,  turns  the  prolonged  shaft  l',  or  leaves  it  at  rest,  according  as  the 
clutch  /,  r,  is  locked  or  opened.  This  second  shaft  bears  the  three  bevel  wheels  m,  m,  m. 
These  work  in  three  corresponding  bevel  wheels  m'  m'  m',  made  fast  respectively  to  the 

three  vertical  shafts  of  the  millstones,  which  pass 
through  the  cast  iron  guide  tubes  m"  m".  These 
are  fixed  in  a  truly  vertical  position  by  the  collar- 
bar  m",  m\fig.  1159.  In  this  figure  we  see  at  m  how 
the  strong  cross-bar  of  cast  iron  is  made  fast  to  the 
wooden  beams  which  support  all  the  upper  mechan- 
ism of  the  mill-work.  The  bearing  m'  is  disposed  in 
an  analogous  manner ;  but  it  is  supported  against 
two  cast  iron  columns,  shown  at  l"  l",  in  ^g.  1168 
The  guide  tubes  m"  are  bored  smooth  for  a  small 
distance  from  each  of  their  extremities,  and  their 
interjacent  calibre  is  wider,  so  that  the  vertical  shafts 
touch  only  at  two  places.  It  is  obvious,  that  when- 
ever the  shaft  l'  is  set  a-going,  it  necessarily  turns 
the  wheels  m  and  m',  and  their  guide  tubes  m";  but  the 
vertical  shaft  may  remain  either  at  rest,  or  revolve, 
according  to  the  position  of  the  lever  click  or  catch 
K,  at  the  top,  which  is  made  to  slide  upon  the  shaft, 
and  can  let  fall  a  finger  into  a  vertical  groove  cut 
in  the  surface  of  that  shaft.  The  clamp-fork  of  the 
click  is  thus  made  to  catch  upon  the  horizontal  bevel- 
wheel  m',  or  to  release  it,  according  as  the  lev^r  k  is 
lowered  or  lifted  up.  Thus  each  millstone  may  be 
thrown  out  of  or  into  gear  at  pleasure. 
These  stones  make  upon  an  average  11  or  12  turns  in 
a  minute,  corresponding  to  three  revolutions  of  the  water- 
wheel,  which  moves  through  a  space  of  3  feet  4  inches  in 
the  second,  its  outer  circumference  being  66  feet.  The 
weight  of  the  upper  stone,  with  its  iron  mountings,  u 
about  6  cwts.,  when  new.  The  charge  of  each  mill  in  dry 
material  is  2  cwts. ;  and  the  water  may  be  estimated  at 
from  one  half  to  the  whole  of  this  weight ;  whence  the  total 
load  may  be  reckoned  to  be  at  least  3  cwts. ;  the  stone,  by 
displacement  of  the  magma,  loses  fully  400  pounds  of  its  weight,  and  weighs  therefore  in 
reality  only  2  cwts.  It  is  charged  in  successive  portions,  but  it  is  discharged  all  at  once. 
When  the  grinding  of  the  silicious  or  feldspar  matters  is  nearly  complete,  a  remarkable 

Vol.  IL  3  Q 


482 


POTTERY. 


POTTERY. 


483 


phenomenon  occurs ;  the  substance  precipitates  to  the  bottom,  and  assumes  in  a  few 
seconds  so  strong  a  degree  of  cohesion,  that  it  is  haidly  possible  to  restore  it  again  to  the 
pasty  or  mamga  state;  hence  if  a  millstone  turns  too  slowly,  or  if  it  be  accidentally 
stopped  for  a  few  minutes,  the  upper  stone  gets  so  firmly  cemented  to  the  under  one, 
that  it  is  difficult  to  separate  them.  It  has  been  discovered,  but  without  knowing  why, 
that  a  little  vinegar  added  to  the  water  of  the  magma  almost  infallibly  prevents  that 
sudden  stiffening  of  the  deposite  and  stoppage  of  the  stones.  If  the  mills  come  to  be 
set  fast  in  this  way,  the  shafts  or  gearing  would  be  certainly  broken,  were  not  some 
safety  provision  to  be  made  in  the  machinery  against  such  accidents.  Mr.  Hall's  con- 
trivance to  obviate  the  above  danger  is  highly  ingenious.  The  clutch  /, /',^^.  1158is 
not  a  locking  ciab,  fixed  in  the  common  way,  upon  the  shaft  l;  but  it  is  composed  as 
''''"  "'''  shown  in^^j.  1161,  62,  63,  64.,  of  a  hoop  t*,  fixed 

upon  the  shaft  by  means  of  a  key,  of  a  collar  r,  and 
of  a  flat  ring  or  washer  x,  with  four  projections,  which 
are  fitted  to  the  collar  r,  by  four  bolts  y.  Fig.  1162 
represents  the  collar  v  seen  in  front ;  that  is,  by  the 
face  which  carries  the  clutch  teeth  ;  and^g.1163  rep- 
resents its  other  face,  which  receives  the  flat  ring  ar, 
fig.  1 164  in  four  notches  corresponding  to  the  four  pro- 
jections of  the  washer-ring.  £ince  the  ring  u  is  fixeil 
upon  the  shaft  l,  and  necessarily  turns  with  it,  it  has 
the  two  other  pieces  at  its  disposal,  namely,  the  collar 

,  ^^  t?,  and  the  washer  X,  because  they  are  always  connected 

with  It  by  the  four  bolts  y,  so  as  to  turn  with  the  ring  7*,  when  the  resistance  they  encounter 
upon  the  shaft  l'  is  not  too  great,  and  to  remain  at  rest,  letting  the  ring  u  turn  by  itself, 
when  that  resistance  increases  to  a  certain  pilch.  To  give  this  degree  of  friction,  we 
need  only  interpose  the  leather  washers  z,  z',fig.  1161.  and  now  as  \i-.<>  collar  coupling, 
box,  V,  slides  pretty  freely  upon  the  ring  «,  it  is  obvious  that  by  tightening  more  or  less 
the  screw  bolts  y,  these  washers  will  become  as  it  were  a  lateral  brake,  to  lighten  more 
or  less  the  bearing  of  the  ring  m,  to  which  thev  are  applied ;  by  regulating  this  pressure, 
everything  may  be  easily  adjusted.  When  the  resistance  becomes  too  great,  the  leather 
washers,  pressed  upon  one  side  by  the  collar  r,  of  the  washer  4-,  and  rubbed  upon  the 
other  side  by  the  prominence  of  the  ring  n,  get  heated  to  such  a  degree,  that  they  are  apt 
to  become  carbonized,  and  require  replacement. 

This  safety  clutch  may  be  recommended  to  the  notice  of  mechanicians,  as  susceptible 
of  beneficial  application  in  a  variety  of  circumstances. 

GREAT  PORCELAIN  MILL, 

The  large  feldspar  and  kaolin  mill,  made  by  Mr.  Hall,  for  Sevres,  has  a  flat  bed  of 
hornstone,  in  one  block,  laid  at  the  bottom  of  a  great  tub,  hooped  strongly  with  iron. 
In  most  of  the  English  potteries,  however,  that  bed  consists  of  several  flat  pieces  of  chert 
or  hornstone,  laid  level  with  each  other.  There  are,  as  usual,  a  spigot  and  faucet  at  the 
side,  for  drawing  off  the  liquid  paste.  The  whole  system  of  the  mechanism  is  very  sub- 
stantial, and  is  supported  by  wooden  beams. 

The  following  is  the  manner  of  turning  the  upper  blocks.  In  ^g.  1157  the  main 
horizontal  shaft  p  bears  at  one  of  its  extremities  a  toothed  wheel,  usually  mounted  upon 

1166  the    periphery    of    the    great 

water-wheel  (yig.  1165.  shows 
this  toothed  wheel  by  a  dotted 
line)  at  its  other  end;  p  car- 
ries the  fixed  portion  p  of  b, 
coupling-box,  similar  to  the 
one  just  described  as  belonging 
to  the  little  mill.  On  the  pro- 
longation of  p,  there  is  a  second 
shaft  p',  which  bears  the  move- 
able portion  of  that  box,  and 
an  upright  bevel  wheel  p" 
Lastly,  in  figs.  1161  and  1165 
there  is  shown  the  vertical 
shaft  Q,  which  carries  at  its 
upper  end  a  large  horizontaj 
., .      .       ,  .^  .         1      -.I.-      ,  cast-iron  wheel  q',  not  seen  in 

this  view,  because  1  is  sunk  withm  the  upper  surface  of  the  turning  hornstone,  like  the 
clamp  d,f,mfig.  1159.  At  the  lower  end  of  the  shaft  q,  there  is  the  bevel  wheel  o'\ 
Fhich  receives  motion  from  the  wheel  f",fig.  1157. 
;  The  shaft  p  always  revolves  with  the  water-wheel  j   but  transmits  its  motion  to  the 


shaft  p'  only  when  the  latter  is  thrown  into  gear  with  the  coupling-box  /)',  by  means  of 
its  forked  lever.     Then  the  bevel  wheel  p'  turns  round  with  the  shaft  p',  and  communicatei 
its  rotation  to  the  bevel  wheel  q",  which  transmits  it  to  the  shaft  Q,  and  to  the  large  cast 
iron  wheel,  which  is  sunk  into  the  upper  surface  of  the  revolving  hornstone. 

The  shaft  q  is  supported  and  centred  by  a  simple  and  solid  adjustment ;  at  its  lower 
part,  it  rests  in  a  step  r',  which  is  supported  upon  a  cast-iron  arch  q',  seen  in  profile  in 
fig.  1167.  its  base  is  solidly  fixed  by  four  strong  bolts.  Four  set  screws  above  R,/g.ll57 
serve  to  set  the  shaft  q  truly  perpendicular ;  thus  supported,  and  held  securely  at  its  lower 
end,  in  the  step  at  B.,figs.  1157  &  1166  it  is  embraced  near  the  upper  end  by  a  brass  bush 
or  collar,  composed  of  two  pieces,  which  moy  be  drawn  closer  together  by  means  of  a 
screw.  This  collar  is  set  into  the  summit  of  a  great  truncated  cone  of  cast-iron,  which 
rises  within  the  tub  through  two  thirds  of  the  thickness  of  the  hornslone  bed;  having  its 
base  firmly  fixed  by  bolts  to  the  bottom  of  the  tub,  and  having  a  brass  collet  to  secure  its 
top.  The  iron  cone  is  cased  in  wood.  When  all  these  pieces  are  well  adjusted  and 
properly  screwed  up,  the  shaft  q  revolves  without  the  least  vacillation,  and  carries  round 
with  it  the  large  iron  wheel  q',  cast  in  one  piece,  and  which  consists  of  an  outer  rim,  three 
arms  or  radii,  and  a  strong  central  nave,  made  fast  by  a  key  to  the  top  of  the  shaft  q,  and 
resting  upon  a  shoulder  nicely  turned  to  receive  it.  Upon  each  of  the  three  arms,  there 
are  adjusted,  with  bolts,  three  upright  substantial  bars  of  oak,  which  descend  vertically 
through  the  body  of  the  revolving  mill  to  within  a  small  distance  of  the  bed-stone ;  and 
upon  each  of  the  three  arcs  of  that  wheel-ring,  comprised  between  its  three  strong  arms, 
there  are  adjusted,  in  like  manner,  five  similar  uprights,  which  fit  into  hollows  cut  in  the 
periphery  of  the  moving  stone.  They  ought  to  be  cut  to  a  level  at  their  lower  part,  to 
suit  the  slope  of  the  bottom  of  the  tub  o,figs.  1157  &  1165  so  as  to  glide  past  it  pretty 
closely,  without  touching. 

The  speed  of  this  large  mill  is  eight  revolutions  in  the  minute.  The  turning  horn- 
stone describes  a  mean  circumference  of  141^  inches  (its  diameter  being  45  inches),  and 
of  course  moves  through  about  100  feet  per  second.  The  tub  o,  is  52  inches  wide  at 
bottom,  56  at  the  surface  of  the  sleeper  block  (which  is  16  inches  thick),  and  64  at  top, 
inside  measure.  It  sometimes  happens  that  the  millstone  throws  the  pastj'  mixture  out 
of  the  vessel,  though  its  top  is  6  inches  under  the  lip  of  the  tub  o;  an  inconvenience 
which  can  be  obviated  only  by  making  the  pap  a  little  thicker ;  that  is,  by  allowing  only 
from  25  to  30  per  cent,  of  water ;  then  its  density  becomes  nearly  equal  to  2*00,  while 
that  of  the  millstones  themselves  is  only  2*7  ;  whence,  supposing  them  to  weigh  only  2 
cwts.,  there  would  remain  an  effective  weight  of  less  than  \  cwt.  for  pressing  upon  the 
bottom  and  grinding  the  granular  particles.  This  weight  appears  to  be  somewhat  too 
small  to  do  much  work  in  a  short  time ;  and  therefore  it  would  be  better  to  increase  the 
quantity  of  water,  and  put  covers  of  some  convenient  form  over  the  tubs.  It  is  estimated 
that  this  mill  will  grind  nearly  5  cwts.  of  hard  kaolin  or  feldspar  gravel,  in  24  hours,  into 
a  proper  pap. 

To  the  preceding  methodical  account  of  the  porcelain  manufacture,  I  shall  now  sub- 
join some  practical  details  relative  to  certain  styles  of  work,  with  comparisons  between 
the  methods  pursued  in  this  country  and  upon  the  Continent,  but  chiefly  by  our  jealous 
rivals  the  French. 

The  blue  printed  ware  of  England  has  been  hitherto  a  hopeless  object  of  emulation  in 
France.  M.  Alexandre  Brongniart,  membre  de  I'Institut,  and  director  of  the  Manvfaciure 
Royal  de  Sevres,  characterizes  the  French  imitations  of  the  Fayence  fine,  ou  ^nglaise,  in 
the  following  terms  :  "  Les  defa-Jts  de  cette  poterie,  qui  tiennent  a  sa  nature,  sonl  de  ne 
pouvoir  aller  sur  le  feu  pour  les  usages  domestiques,  et  d'avoir  un  vemis  tendre,  qui  se 
laisse  aisement  entamer  par  les  instruments  d'acier  et  de  fer.  Mais  lorsque  cette  poterie 
est  mal  fabriquee,  ou  fabriquee  avec  une  economic  mal  entendue,  ses  defauts  deviennenl 
bien  plus  graves ;  son  vemis  jaunatre  et  tendre  tressaille  souvent ;  il  se  laisse  entamer 
ou  user  avec  la  plus  grande  facilite  par  les  instruments  de  fer,  oupar  I'usage  ordinaire. 
Les  fissures  que  ce  tressaillement  ou  ces  rayures  ouvrent  dans  le  vernis  permettent  aux 
matieres  grasses  de  penetrer  dans  le  biscuit,  que  dans  les  poteries  affectees  de  ce  defaut,  a 
presque  toujours  une  texture  lache ;  les  pieces  se  salissent,  s'empuantissent,  et  se  brisent 
meme  avec  la  plus  grande  facilite."* 

What  a  slaze,  to  be  scratched  or  grooved  with  soft  iron ;  to  fly  oflT  in  scales,  so  as  to 
let  grease  soak  into  the  biscuit  or  body  of  the  ware;  to  become  foul,  stink,  and  break  with 
the  utmost  ease !  The  refuse  crockery  of  the  coarsest  pottery  works  in  the  United  King- 
dom would  hardly  deserve  such  censure. 

In  the  minutes  of  evidence  of  the  Enquete  MinistMiUe,  published  in  1835,  MM.  de  Saint 
Cricq  and  Lebeuf,  large  manufacturers  of  pottery-ware  at  Creil  and  Montereau,  give  a 
very  gratifying  account  of  the  English  stoneware  manufacture.  They  declare  that  the  Eng- 
lish possess  magnificent  mines  of  potter's  clay,  many  leagues  in  extent ;  while  those  of  the 

*  Diet.  Technologique,  torn,  xrii.,  article  Poteries,  p  1U3. 


484 


POTTERY. 


I.'     «1 


French  are  mere  patches  or  pots.  Besides,  England,  they  say,  having  upwards  of  20C 
potteries,  can  constantly  employ  a  great  many  public  flint-mills,  and  thereby  obtain  thai 
indispensable  material  of  the  best  quality,  and  at  the  lowest  rate.  «  The  mill  erected  by 
M.  Brongniart,  at  Sdvres,  does  its  work  at  twice  the  price  of  the  English  mills  The 
fuel  costs  in  England  one  fourth  of  what  it  does  in  France.  The  expense  of  a  kiln-round 
m  the  latter  country,  is  200  francs ;  while  in  the  former  it  is  not  more  than  60  "  AAer 
a  two-months  tour  among  the  English  potteries,  these  gentlemen  made  the  followine  ad- 
ditional observations  to  their  first  official  statement :— 

"The  clay,  which  goes  by  water  carriage  from  the  counties  of  Devon  and  Dorset  into 
Staffordshire,  to  supply  more  than  200  potteries,  clustered  together,  is  delivered  to  them 
at  a  cost  of  4  francs  (3*.  2d.)  the  100  kilosrrammes  (2  cwt.) ;   at  Creil,  it  costs  4f  50c 
and  at  Mintereau,  only  2/.  40c.    There  appears,  therefore,  to  be  no  essential  difference 
m  the  price  of  the  clay;  but  the  quality  of  the  English  is  much  superior,  being  inqon- 
testably  whiter,  purer,  more  homogeneous,  and  not  turning  red  at  a  hi^h  heat  like  the 
French.''    The  grinding  of  the  flints  costs  the  English  potter  4*^/.  per  100  kilos.',  and  the 
French  6d. ;  but  as  that  of  the  latter  is  in  general  ground  dry,  it  is  a  coarser  article.    The 
kaolin,  or  chma  clay,  is  imported  from  Cornwall  for  the  use  of  many  French  potteries  • 
but  the  transport  of  merchandise  is  so  ill  managed  in  France,  that  while  2  cwts.  cost  in 
Staflordshire  only  8/.  7oc.  (about  7*.  Id.),  they  cost  12/.   at  Creil,  and  13/.  50c.   al 
Montereau.    The  white  lead  and  massicot,  so  much  employed  for  elazes,  are  62  per  cent 
dearer  to  the  French  potters  than  the  English.     As  no  French  mill  has  succeeded  in 
making   unsized    paper   fit  for    printing  upon   stoneware,   our   potters   are   under   the 
necessity  of  fetching  it  from  England  ;   and,  under  favor  of  our  own  custom-house,  are 
allowed  to  import  it  at  a  duty  of  165/   per  100  kilogrammes,  or  about  8rf.   per  pound 
iLnghsh.    No  large  stock  of  materials  need  be  kept  by  the  English,  because  everr 
*''^-**^  !.T^       ^^^  ^^^"  wanted  from  its  appropriate  wholesale  dealers ;   but  the  case  is 
quite  different  with  the  French,  whose  stocks,  even  in  small  works,  can  never  safely  be 
less  m  value  than  150,000/  or  200,000/  ;   constituting  a  loss  to  them,  in  interest  upon 
their  capital,  of  from  7,500/   to  10,000/   per  annum.     The  capital  sunk  in  buildin^ris 
lar  less  in  England  than  in  France,  in  consequence  of  the  different  stvles  of  erectino-  stone- 
ware factories  in  the  two  countries.    M.  de  Saint  Cricq  informs  us,' that  Mr.  Clewes  of 
bhelton,  rents  his  works  for  10,000/  (380/.)  per  annum;  while  thfe  similar  ones  of  Creil 
and  Montereau,  m  France,  have  cost  each  a  capital  outlay  of  from  500,000/  to  600  000/* 
and  in  which  the  products  are  not  more  than  one  half  of  Mr.  Clewes'.     «  This  forms  a 
balance  against  us,"  says  M.  St.  C,  "of  about  20,000/  per  annum;   or  nearly  800/ 
sterling.     Finally,  we  have  the  most  formidable  rival  to  our  potteries  in  the  extreme 
dexterity  of  the  English  artisans.     An  enormous  fabrication  permits  the  manufacturers 
to  employ  the  same  workmen  during  the  whole  year  upon  the  same  piece ;   thus  I  have 
seen  at  Shelton  a  furnisher,  for  sixpence,  turn  off  100  pieces,  which  cost  at  Creil  and 
Montereau  30  sous  (1*.  2^d.) ;  yet  the  English  workman  cams  18/  75c.  a  week,  while 
the  French  never  earns  more  than    15/      I  have  likewise  seen  an  English  moulder 
expert  enough  to  make  25  waterpots  a  day,  which,  at  the  rate  of  2d.   a  piece,  brin*-  him 
4*.  2d.  of  daily  wages;   while  the  French  moulder,  at  daily  wages  also  of  4*.  2d  "turns 
out  of  his  hands  only  7,  or  at  most  8  pots.     In  regard  to  hollow  wares,  the  English  may 
be  fairly  allowed  to  have  an  advantage  over  us,  in  the  cost  of  labor,  of  100  per  cent  • 
which  they  derive  from  the  circumstance,  that  there  are  in  Staffordshire  60,000  operatives* 
men,  women,  and  children,  entirely  dedicated  to  the  stoneware  manufacture ;  concentra' 
ting  all  their  energies  within  a  space  of  10  square  leagues.  Hence  a  most  auspicious  choice 
ol  good  practical  potters,  which  cannot  be  found  in  France." 

M.  Saint  Amans,  a  French  gentleman,  whp  spent  some  years  in  Staffordshire,  and  has 
lately  erected  a  large  pottery  in  France,  says  the  English  surpass  all  other  nations  in 
manufacturing  a  peculiar  stoneware,  remarkable  for  its  lightness,  strength,  and  ele<'ance- 
as  also  m  printing  blue  figures  upon  it  of  every  tint,  equal  to  that  of  the  Chinese  by 
processes  of  singular  facility  and  promptitude.  After  the  biscuit  is  taken  out  of 'the 
kiln,  the  fresh  impression  of  the  engraving  is  transferred  to  it  from  thin  unsized  paper 
previously  immersed  in  strong  soap  water ;  the  ink  for  this  purpose  being  a  compound 
of  arseniate  of  cobalt  with  a  flux,  ground  up  with  properly  boiled  linseed  oil  The 
copper-plates  are  formed  by  the  graving  tool  with  deeper  or  shallower  lines,  according'  to 
the  variable  depth  of  shades  in  the  design.  The  cobalt  pigment,  on  meltine,  spreads"  so 
as  to  give  the  soft  effect  of  water^iolor  drawing.  The  paper,  being  still  moist,  is 
readily  applied  to  the  slightly  rough  and  adhesive  surface  of  the  biscuit,  and  may  be 
rubbed  on  more  closely  by  a  dossil  of  flannel.  The  piece  is  then  dipped  in  a  tub  of  water 
whereby  the  paper  gets  soft,  and  may  be  easily  removed,  leaving  upon  the  pottery  the  pig- 
ment of  the  engraved  impression.  After  being  gently  dried,  the  piece  is  dipped  into  the 
glaze  mixture,  and  put  into  the  enamel  oven. 


POTTER'S  OVEN. 


285 


Composition  of  the  Earthy  Mixtures, 

The  basis  of  the  English  stoneware  is,  as  formerly  stated,  a  bluish  clay,  brought  from 
Dorsetshire  and  Devonshire,  which  lies  at  the  depth  of  from  25  to  30  feet  beneath  tYie 
surface.  It  is  composed  of  about  24  parts  of  alumina,  and  76  of  silica,  with  some  other 
ingredients  in  very  small  proportions.  This  clay  is  very  refractory  in  high  heats,  a  pro- 
perty which,  joined  to  its  whiteness  when  burned,  renders  it  peculiarly  valuable  for  pot- 
tery. It  is  also  the  basis  of  all  the  yellow  biscuit-ware  called  cream  color ,  and  in  general 
of  what  is  called  the  printing  body ;  as  also  for  the  semi-vitiified  porcelain  of  Wedgewood's 
invention,  and  of  the  tender  porcelain. 

The  constituents  of  the  stoneware  are,  that  clay,  the  powder  of  calcined  flints,  and  of  the 
decomposed  feldspar  called  Cornish  stone.  The  proportions  are  varied  by  the  difl'erenc 
manufacturers.  The  following  are  those  generally  adopted  in  one  of  the  principal  estab- 
lishments of  Staffordshire : — 

For  cream  color,  Silex  or  ground  flints         ------       20  parts 

Clay 100 

Cornish  stone  ---.---2 

Composition  of  the  Paste  for  receiving  the  Printing  Body  under  the  Glaze. 

For  this  purpose  the  proportions  of  the  flint  and  the  feldspar  must  be  increased.  The 
substances  are  mixed  separately  with  water  into  the  consistence  of  a  thick  cream,  which 
weighs  per  pint,  for  the  flints  32  ounces,  and  for  the  Cornish  stone  28.  The  china  clay 
of  Cornwall  is  added  to  the  same  mixture  of  flint  and  feldspar,  when  a  finer  pottery  or 
porcelain  is  required.  That  clay  cream  weighs  24  ounces  per  pint.  These  24  ounces  in 
weight  are  reduced  to  one  third  of  their  bulk  by  evaporation.  The  pint  of  dry  Cornish  clay 
weighs  17  ounces,  and  in  its  first  pasty  state  24,  as  just  stated.  The  dry  flint  powder  weighs 
14^  ounces  per  pint ;  which  when  made  into  a  cream  weighs  32  ounces.  To  40  measures  of 
Devonshire  clay-cream  there  are  added, 

13  measures  of  flint  liquor. 
12        —        Cornish  clay  ditto. 
1        —        Cornish  stone  ditto. 
The  whole  are  well  mixed  by  proper  agitation,  half  dried  in  the  troughs  of  the  slip-kiln, 
and  then  subjected  to  the  machine  for  cutting  up  the  clay  into  junks.    The  above  paste, 
when  baked,  is  very  white,  hard,  sonorous,  and  susceptible  of  receiving  all  sorts  of  im- 
pressions from  the  paper  engravings.     When  the  silica  is  mixed  with  the  alumina  in  the 
above  proportions,  it  forms  a  compact  ware,  and  the  impression  remains  fixed  between  the 
biscuit  and  the  glaze,  without  communicating  to  either  any  portion  of  the  tint  of  the  me- 
tallic color  employed  in  the  engraver's  press.    The  feldspar  gives  strength  to  the  biscuit, 
and  renders  it  sonorous  after  being  baked ;  while  the  china  clay  has  the  double  advantagt 
of  imparting  an  agreeable  whiteness  and  great  closeness  of  grain. 

Dead  silver  on  porcelain  is  much  more  easily  affected  by  fuliginous  vapours  than 
burnished.  It  may,  however,  by  the  following  process  be  completely  protected.  The 
silver  must  be  dissolved  in  very  dilute  acid,  and  slowly  precipitated  ;  and  the  metallic 
precipitate  well  washed.  The  silver  is  then  laid  (in  wavy  lines?)  upon  the  porcelain 
pefore  being  coloured  (or  if  coloured,  the  colour  must  not  be  any  preparation  of  gold) 
in  a  pasty  state  and  left  for  24  hours,  at  the  expiration  of  which  time  the  gold  is  to  be 
laid  on  and  the  article  placed  in  a  moderate  heat  The  layer  of  gold  must  be  very  thin, 
and  laid  on  with  a  brush  over  the  silver  before  firing  it ;  when  by  the  aid  of  a  flux  and 
a  cherry  red  heat  the  two  metals  are  fixed  on  the  porcelain. — NewtorCs  Journal,  xxxL  128. 

POTTER'S  OVEN.  A  patent  was  obtained  in  August,  1842,  by  Mr.  W.  Ridgway 
for  the  following  construction  of  oven,  in  which  the  flames  from  the  fireplaces  are 
conveyed  by  parallel  flues,  both  horizontal  and  vertical,  so  as  to  reverberate  the  whole 
of  the  flame  and  heat  upon  th6  goods  after  its  ascension  from  the  flues.  His  oven  is 
built  square  instead  of  round,  a  fire-proof  partition  wall  being  built  across  the  middle 
of  it,  dividing  it  into  two  chambers,  which  are  covered  in  by  two  parallel  arches.  The 
fireplaces  are  built  in  the  two  sides  of  the  oven  opposite  to  the  partition  wall;  from 
which  fireplaces  narrow  flues  rise  in  the  inner  face  of  the  wall,  and  distribute  the 
flame  in  a  sheet  equally  over  the  whole  of  its  surface.  The  other  portion  of  the  heat 
is  conveyed  by  many  parallel  or  diverging  horizontal  flues,  under  and  across  the  floor 
or  hearth  of  the  oven,  to  the  middle  or  partition  wall ;  over  the  surface  of  which  the 
flame  which  ascends  from  the  numerous  flues  in  immediate  contact  with  the  wall  is 
equally  distributed.  This  sheet  of  ascending  flame  strikes  the  shoulder  of  the  arch, 
and  is  reverberated  from  the  seggars  beneath,  till  it  meets  the  flame  reverberated  from 
the  opposite  side  of  the  arch,  and  both  escape  at  the  top  of  the  oven.  The  same  con- 
struction is  also  applied  to  the  opposite  chamber.    In  figs,  1166,  67,  a,  represents  the 


f 


r 


486 


PRESS.  HYDRAULia 


I'   ,;l 


1166 


1167 


square  walls  or  body  of  the  oven ;  b,  the  partition  wall ;  c,  the  fireplaces  or  fum»cea 
with  their  iron  boilers  ;  d,  the  mouths  of  the  furnaces  for  introducing  the  fuel ;  /,  Ihc 
ash-pits;  g,  the  horizontal  flues  under  the  hearth  of  the  oven;  h,  the  vertical  flues; 
i,  the  vents  in  the  top  of  the  arches ;  and  k,  the  entrances  to  the  chambers  of  the 
ovens. 

PRECIPITATE,  is  any  matter  separated  in  minute  particles  from  the  bosom  of  a  fluid, 
which  subsides  to  the  bottom  of  the  vessel  in  a  pulverulent  form. 

PRECIPITATION,  is  the  actual  subsidence  of  a  precipitate. 

PRESS,  HYDRAULIC.  Though  the  explanation  of  the  principles  of  this  power- 
ful machine  belongs  to  a  work  upon  mechanical  engineering,  ratlier  than  to  one  upon 
1168  1169  ^ 


manufactures,  yet  as  it  is  often  referred  to  in  this  volume,  a  brief  description  of  it  caz^ 
not  be  unacceptable  to  many  of  my  readers. 

The  framing  consists  of  two  stout  cast-iron  plates  a,  b,  which  are  strengthened  by  pro- 
jecting ribs,  not  seen  in  the  section,  Jl^.  1168.  The  top  or  crown  plate  6,  and  the  base- 
plate a,  a,  are  bound  most  firmly  together  by  4  cylinders  of  the  best  wrought  iron,  <?,  e, 
which  pass  up  through  holes  near  the  ends  of  the  said  plates,  and  are  fast  wedged  'in 
them.  The  flat  pieces  e,  e,  are  screwed  to  the  ends  of  the  crown  and  base  plates,  so  as 
to  bind  the  columns  laterally.  /,  is  the  hollow  cylinder  of  tlie  press,  which,  as  well  as 
the  ram  or,  is  made  of  east-iron.  The  upper  part  of  the  cavity  of  the  cylinder  is  east 
narrow,  but  is  truly  and  smoothly  rounded  at  the  boring-mill,  so  as  to  fit  pretty  closely 
round  a  well-turned  ram  or  piston;  the  under  part  of  it  is  left  somewhat  wider 
in  the  casting.  A  stout  cup  of  leather,  perforated  in  the  middle,  is  put  upon  the  ram, 
and  serves  as  a  valve  to  render  the  neck  of  the  cylinder  perfectly  water-tight  by  filling 
up  the  space  between  it  and  the  ram ;  and  since  the  mouth  of  the  cup  is  turned  down- 
wards, the  greater  the  pressure  of  the  water  upwards,  the  more  forcibly  are  the  edges 
of  the  leather  valve  pressed  against  the  insides  of  the  cylinder,  and  the  tighter  does  the 
joint  become.     This  was  Bramah's  beautiful  invention. 

Upon  the  top  of  the  ram,  the  press-plate,  or  table,  strengthened  with  projecting  ridges, 
rests,  which  is  commonly  called  the  follower,  because  it  follows  the  ram  closely  in  its 


PRINTED  FABRICS. 


487 


1170 


ini 


l'•■^'.^'^ 


descent.  This  plate  has  a  half-round  hole  at  each 
of  its  four  corners,  corresponding  to  the  shape  of 
the  four  iron  columns  along  which  it  glides  in  its 
up-and-down  motions  of  compression  and  relaxa- 
tion. 

k,  k,  figs.  1168  and  1169.  is  the  framing  of  a 
force  pump  with  a  narrow  barrel;  i  is  the  well  for 
containing  water  to  supply  the  pump.  To  spare 
room  in  the  engraving,  the  pump  is  set  close  to  the 
press,  but  it  may  be  removed  to  any  convenient 
distance  by  lengthening  the  water-pipe  «,  which 
connects  the  discharge  of  the  force  pump  with  the 
inside  of  the  cylinder  of  the  press.  Fi*r.  1170  is 
a  section  of  the  pump  and  its  valves.  The  pump 
fn,  is  of  bronze ;  the  suction-pipe  n,  has  a  conical 
valve  with  a  long  tail;  the  solid  piston  or  plunger 
p^  is  smaller  than  the  barrel  in  which  it  plays,  and 
passes  at  its  top  through  a  stuffing-box  q;  r  is  the  pressure-valve,  »  is  the  safety- 
valve,  which,  in  fig.  116^  is  seen  to  be  loaded  with  a  weighted  lever;  /  is  the  dis- 
charge-valve, for  letting  the  water  escape,  from  the  cylinder  beneath  the  ram,  back 
into  the  weli.  See  the  winding  passages  in  fig.  1171.  wis  the  tube  which  conveys 
Ihe  water  from  the  pump  into  the  press-cylinder.  In  /g.  1169  two  centres  of  motion  fw 
the  pump-lever  are  shown.  By  shifting  the  bolt  into  the  centre  nearest  the  pump-rod, 
the  mechanical  advantage  of  the  workman  may  be  doubled.  Two  pumps  are  generally 
mounted  in  one  frame  for  one  hydraulic  press ;  the  larger  to  give  a  rapid  motion  to  the 
ram  at  the  beginning,  when  the  resistance  is  small ;  the  smaller  to  give  a  slower  bat 
more  powerful  impulsion,  when  the  resistance  is  much  increased.  A  pressure  of  500  tons 
may  be  obtained  from  a  well-made  hydraulic  press  with  a  ten-mch  ram,  and  a  two  and  a 
one  inch  set  of  pumps.    See  Stearine  Press. 

PRINCE'S  METAL,  or  Prince  Rupert's  metal,  is  a  modification  of  brass. 
PRINTED  FABRIC^  whether  dyed,  felted  or  woven. — Exhibition,  Section  3,  Clou 
18.  The  colour  printer  and  dyer  form  the  subjects  represented  by  this  class.  The  arts 
practised  by  them  have  made  most  important  progress  during  late  years.  At  first,  taught 
only  by  a  long  and  varied  experience,  the  importer  of  colour  was  restricted  to  the  use 
of  a  few  comparatively  simple  substances  for  the  extraction  of  colour  and  its  ai>plication 
to  various  fabrics.  But  since  chemistry  has  been  allowed  to  occupy  a  part  of  the  atten- 
tion of  the  manufacturer,  a  very  different  result  has  arisen.  The  indications  of  expe- 
rience are  confirmed  by  the  teachings  of  philosophy,  and  in  a  large  number  of  instances 
a  vast  economy  of  material,  time  and  labour  has  been  effected.  In  addition,  chemistry 
has  brought  to  light  new  compounds  and  new  means  of  obtaining  dyes  and  colours  of 
great  brilliance  from  a  few  simple  combinations.  It  is  consequently  now  almost  uni- 
versal to  find  that  attached  to  the  extensive  works  of  the  dyer  and  colour-printer  is  a 
large  laboratory  fitted  up  for  chemical  investigations,  and  the  processes  developed  in 
which  are  often  the  source  of  a  very  great  commercial  prosperity'. 

The  print  works  of  Lancashire,  and  particularly  of  Manchester  and  its  vicinity,  form 
the  most  extensive  sources  of  printed  and  dyed  articles.  Glasgow,  Carlisle,  Crayford, 
Paisle}^  and  other  places,  also  contain  important  works  of  a  somewhat  similar  descrip- 
tion. The  origin  of  cotton  printing  appears  to  have  taken  place  in  the  vicinity  of  the 
metropolis  in  1675. 

During  the  last  half  century,  a  surprising  development  of  printing  in  colour  and 
dyeing  has  taken  place.  It  is  estimated  that^  at  its  commencement,  the  annual  quantity 
of  cotton  printed  was  32,869,729  yards.  But  in  1830,  this  quantity  had  attained  the 
enormous  increase  of  347,450,299  yards;  and  it  has  since  still  further  increased.  Th« 
print  works  of  Lancashire,  and  other  places,  form  a  surprising  spectacle  of  the  operation 
of  chemical  and  mechanical  forces  on  the  great  scale.  That  which  was  formerly  the 
labour  of  weeks  is  now  performed  in  a  day.  A  piece  of  cloth  is  printed  at  the  rate  of 
hundreds  of  yards  in  a  day.  On  one  side  of  a  machine-room  it  ascends  moist,  with 
colour  from  the  engraved  copper  c^'linder ;  on  the  other  hand  it  descends  dried,  ready 
for  the  final  processes.  The  printing  machines  are  marvels  of  ingenuity ;  the  pattern  is 
applied  by  the  engraved  surface  of  one  or  more  copper  cylinders,  which  have  received  the 
pattern  from  a  small  steel  cylinder,  or  "  mill "  capable  of  impressing  several  witb  the 
same  design,  and  thus  saving  the  cost  of  repeated  engraving.  At  firgt  only  one  colour 
could  be  applied ;  now  from  six,  or  even  eight  and  ten  colours  are  applied  in  constant 
succession.  These  machines  perform  their  work  with  great  accuracy  and  speed,  and 
produce  all  the  commoner  patterns  seen  in  daily  use ;  but  hand  labour  is  still  employed, 
even  in  these  works,  for  fine  or  complicated  work,  and  more  particularly  for  printing 
mousseline-de-laine  dresses,  <fec.  The  goods  thus  printed  are  exported  in  immense  quan- 
tities to  all  parts  of  the  world,  a  large  portion  being  also  retained  for  home  use.     Foi 


V 


488 


PRINTED  FABRICS. 


1  (> 


foreign  countries  a  certain  peculiarity  of  chromatic  arrangement  is  necessary  in  order 
to  render  the  articles  adapted  to  the  taste  of  purchasers. 

The  art  of  the  dyer  in  towns  is  a  manufacture  on  a  smaller  scale,  and  carried  on  gene- 
rally in  small  establishments  devoted  to  that  purpose.  But  extensive  dye-works  exist, 
which  are  employed  in  imparting  various  colours  to  cloth,  Ac,  on  the  great  scale  To 
the  prosperous  pursuit  of  either  of  these  arts  it  is  beginning  to  be  more  and  more 
■widely  felt  that  an  enlightened  and  philosophical  mind  is  of  the  first  consequence 

Formerly  the  application  of  coloured  designs  to  fabrics  of  various  kinds  was  entirely 
eflFected  by  what  is  called  block-printing,  and  which  in  fact  cl<Mely  resembles  type 
printing.  A  block  of  wood  or  metal,  or  a  combination  of  both,  being  engraved  with  the 
pattern,  received  the  colour  by  the  ordinary  means,  and  this  was  then  transferred  bv 
hand  to  the  fabric.  For  every  diflFerent  colour  a  different  block  was  required,  and  in 
complicated  patterns,  with  many  colours,  the  process  was  excessively  tedioua  It  is. 
however,  still  largely  employed,  where  great  care  in  the  application  of  the  colour  and 
sharpness  of  definition  in  the  pattern  is  required,  but  block  printing  can  only  be  remu- 
nerative in  the  better  descriptions  of  goods,  as  the  infinitely  more  rapid  and  economical 
process  of  the  cylinder  printing  has  almost  superseded  it  for  the  production  of  those  of 
commoner  kinds. 

71.  Hammerdey,  J.  A.  Principal  of  the  School  of  Design,  Manchester,  Designer. 
Picture  in  oil  colours,  showing  the  principles  upon  which  floral  forms  are  adapted  to 
designs  for  textile  fabrics ;  exhibiting  a  central  picture  of  a  composition  of  flowers, 
imitated  from  nature,  surrounded  by  200  geometrical  spaces,  each  containing  a  separate 
design,  and  showing  the  mode  of  applying  these  flowers  to  manufactures. 

For  textile  fabrics,  natural  flowers  have  been  represented  under  conventional  forms; 
so  that,  without  departing  from  the  original  type,  the  character  of  design  may  not  be 
pictorial  The  patterns  of  eastern  chintzes  are  but  fantastic  imitations  of  flowers ;  and 
the  pure  taste  of  ancient  Greece  discarded  from  female  dress  all  ornament  but  that  of 
a  flat  character ;  where  borders  of  the  vine  or  ivy-leaf;  or  of  the  honeysuckle,  have  been 
adopted,  they  are  flat.  The  oriental  cashmere  style,  the  stuffs  and  carpets  of  Persia  and 
Turkey,  the  tartan  of  the  Scot,  the  arabesques  of  ancient  Rome  and  Moorish  decora- 
tion, while  admitting  of  every  variety  of  beauty  in  design  or  colour,  are  examples  of  a 
flat  as  opposed  to  a  relieved  pictorial  style  of  ornament. 

PRINTING.  Galvanography,  in  the  short  interval  which  has  elapsed  since  its  first 
appearance^  has  been  divided  into  two  methods.  The  first  consists  in  the  composition 
being  executed  by  the  artist  himself  with  colour  (roasted  terra  di  Sienna,  or  black-lead 
and  linseed  oil)  and  the  ordinary  brush,  in  the  same  manner  as  an  Indian-ink  drawing 
upon  a  silvered-copper  plate,  which  is  then  placed  in  the  galvanoplastic  apparatus,  in 
order  to  obtain  a  copy  of  the  raised  drawing.  The  copy,  or  sunk  plate,  thus  obtained, 
18  touched  up  with  the  usual  copper-plate  engraving  tools,  and  the  light  and  shade  im- 
proved, and  then  serves  for  printing  from :  it  can  of  course,  by  means  of  the  galvanic 
apparatus,  be  multiplied  to  any  desired  extent  This  method  certainly  possesses  the 
advantage  of  allowing  rapidity  in  execution  and  great  freedom  of  treatment.  In  the 
second  method  of  galvanography,  the  outlines  of  the  given  drawing  are  etched  in  the 
usual  manner,  the  various  tones  of  the  picture  laid  on  with  the  roulette,  and  a  galvano- 
plastic copy  of  this  sunk  plate  is  then  produced.  On  this  second  (raised)  plate,  the 
artist  completes  his  picture  by  means  of  chalk  and  Indian  ink,  and  puts  in  the  lights 
and  shades,  <fec.  From  this  a  second  galvanoplastic  copy  is  produced.  This  second 
copy,  or  sunk  plate,  the  third  plate  in  the  order  of  procedure,  serves,  after  being  touched 
up,  for  printing  from  in  the  copper-plate  press. 

PRINTING  INK.  {Encre  dHmprimerie,  Fr. ;  Buchdrucker/arbe,  Germ.)  After 
reviewing  the  different  prescriptions  sriven  by  Moxon,  Breton,  Papillon,  Lewis,  those  in 
Nicholson's  and  the  Messrs.  Aikins'  Dictionaries,  in  Rees'  Cyclopaedia,  and  in  the  French 
Printer's  Manual,  Mr.  Savage*  says,  that  the  Encyclopaedia  Britannica  is  the  only  work, 
to  his  knowledge,  which  has  ?iven  a  recipe  by  which  a  printing  ink  might  be  made,  thai 
could  be  used,  though  it  would  be  of  inferior  quality,  as  acknowledged  by  the  editor ;  for 
it  specifies  neither  the  qualities  of  the  materials,  nor  their  due  proportions.  The  fine 
black  ink  made  by  Mr.  Savage,  has,  he  informs  us,  been  pronounced  by  some  of  our  first 
printers  to  be  unrivalled  ;  and  has  procured  for  him  the  large  medal  from  the  Society  for 
the  Encouragement  of  Arts. 

1.  Linseed  oil. — Mr.  Savage  says,  that  the  linseed  oil,  however  long  boiled,  unless  sel 
fire  to,  cannot  be  brought  into  a  proper  state  for  forming  printing  ink ;  and  that  the 
flame  may  be  most  readily  extinguished  by  the  application  of  a  pretty  tight  tin  cover  to 
the  top  of  the  boiler,  which  should  never  be  more  than  half  full.  The  French  prefer 
nut  oil  to  linseed ;  but  if  the  latter  be  old,  it  is  fully  as  good,  and  much  cheaper,  in  this 
country  at  least. 

2.  Black  rosin  is  an  important  article  in  the  composition  of  good  ink ;  as  by  melting 

*  lu  his  work  q&  the  Prepai-ation  of  Pnntini;  Ink  ,  8vo.,  Lor.don.  1839. 


PRINTING  MACHINE.  ^^ 

It  in  the  oil,  when  that  ingredient  is  sufficiently  boiled  and  burnt,  the  two  combine  and 
nTn?ihT>r°r^  approxinjating  to  a  natural  bllsam,  like  that  of  CanadaTwhiSi  isll^ 
one  of  the  best  varnishes  that  can  be  used  for  printing  ink.  '  ^ 

6.  aoap.^lbis  is  a  most  important  ingredient  in  printers'  ink,  which  is  not  even 
mentioned  m  any  of  the  recipes  prior  to%hat  in  the  Encycloi^irBritannica  To? 
Tn  «ftpr  T^'  »"k  a<^c«mulates  upon  the  face  of  the  types,  so  as^pletely  to^W  the« 

alkaHne  e."Tnd  I't  s'kfn:'^"'""""'  '^-^^  *^^^"  ^^^ '  ''  ""^  -'  wasVoffTitho^ 
aiKaiine  lejs,  and  it  skins  over  very  soon  in  the  pot.     Yellow  rosin  soao  is  thp  hf»^t  far 

blackinksj  for  those  of  light  and  delicate  shadesfwhite  curd  soaTinrefLable      T^ 

r^tl'^^^^Ti^  ^^'  '"'""^"^  '^^  ^'"P^ession  irregular,  and  to  prevenrtheink7^^^^^ 

n4;  ;^dT^:ts7o?ra^^^  '^-  ^^ '-  ^'^  --  - 

a.  Ivory  black  is  too  heavy  to  be  used  alone  as  a  pigment  for  i^rinting  ink  •  but  it  mav 
be  added  with  advantage  by  grinding  a  little  of  it  upon  a  muller  X  the  lamp  black  foJ 

♦oif*  ^"f^u  ^I?'"'''  "'*  "^'^^  *"  ^"1"*^  ^^^§^^  of  Prussian  blue,  added  in  small  nronortion 
takes  off   he  brown  tone  of  certain  lamp  black  inks.     Mr.  Savage  JecommeE7i^t?; 
Ir^dian  r.d  to  be  ground  in  with  the  indigo  and  Prussian  blue,  to'|wrrrTch?oirti^lh: 

hvl'  cf '''*'''"  f  ''"^T'  *^  ^^^   ^y  ^^-  A^^e»'  Plough-court,  Lombard-street    mixed, 
by  a  stone  and  a  muller,  with  a  due  proportion  of  soap  and  pigment  forms  an  ^tem 
poraneous  ink,  which  the  printer  may  employ  Very  ad?antageoSsl  whenTe  4he8  To" 
execute  a  job  m  a  peculiarly  neat  manner,     Canada  balsam  does^ofLswerquUe  12 

fKA^fn  *^^  "f"^^  ^^^'J"^  ***  ""^  ^^**"  ^^^  ^«i^i"8^  «'^  a  bit  of  burning  paper  stuck  in 
he  cleft  end  of  a  long  stick  should  be  applied  to  the  su/face,  to  set  it  on  fire  asl^on  ^^ 
the  vapor  will  burn;  and  the  flame  should  be  allowed  to  continue  (the  StXi^ 
r^r  rn''"'^'^'!^'^"',  7^'  '^^  fi^^'O--  '^^^'^  t^ken  from  under  the  p^  ml 
fn^  K  ^  """"'"''t  T^^  "P^'*  *  pallet-knife,  draws  out  into  strings  of  about  ha^  a? 
inch  long  between  the  fingers.  To  six  quarts  of  linseed  oil  thus  treated  six  oound.  nf 
rosin  should  be  gradually  added,  as  soon  as  the  froth  of  the  eLmdon  hTs  ^^^^^^^^^^ 
Whenever  the  rosm  is  dissolved,  one  pound  and  three  quarters  of  dry  brown  soap  of  t1?« 
best  quality  cut  into  slices,  is  to  be  introduced  cautiously,  for  its  waterT  cZbina Jn^ 
causes  a  v^lent  intumescence.  Both  the  rosin  and  soap  should  be  wdl  sUrred^ih  £e 
Kl^ionltStle^nr  "  '^  "^"  '''  "^^'^  ''^  ^^^'  ^  ^^^  ^«  complete  tllo^finllSn^? 

Put  next  of  well  ground  indigo  and  Prussian  Whp  pnnh  91  «»«/.««  •  . 
sufficiently  large  toLld  aU  .he^„k.ar„*„"grhipl\tof^^^^^^ 

«d  3J  pounds  of  good  vegelable  lamp  black;  then  add  the  wLm  T«nTsh  b^oTde^ree/ 
carefally  sUrnng,  to  produce  a  perfect  incorporation  of  all  the  ingre^ents     ThTs  mS 

redydc.  ^"iwerp  oiue,  lustie,  umber,  sepia,  browns  mixed  with  Venetian 

Int'^S'lho'^^^^^^^^  -^'--r'  ^'-^    ^-^ckmaschine,  Germ.) 

^r^orirksl:  v^^^^^^^^^  ^h-  P^'-l-tive  arts,  aft^r  a  long 

S  matter,  the  contemplative  mind  can^^^^^^^  some  new  conquest  over  the  inertia 

which  the'academical  philosopher  has  generS^lnlLj^J^^^      T^  '^^^  insignificant  part 
Eno'rossed  with  hnriPn  Jiw;         gen eraUy  played  m  such  memorable  events. 

,rufsrKlisTute';r„\vtfe'MieTsr"the  t^^^t'  "'^  ""."'>""  «»" 
disdains  to  soil  his  hands  with  th<«?hSS  onl,^,?!  .  k°[  n  ?""'"»««s.  """l 
the  arts  must  necessarily  beein.  He  does  It  de?m^  -  r  "^'"^  *"  "nprovements  i. 
unit  has  worked  out  its  own  granderand  ?„H.^„  r"*^*' !!"  "^""^^ 
.ummate  skill.  In  this  spirit  thrmerof"„ec,?I»rrl!-"  "'"*  r^SV'*'"''  *"''  '^• 
rteamen^neof  Newcomen%i:ithc"trsa„ZtUmr^^^^^^^  "^^'^"^  ^'"  ^  ^'"?"'" 
.hey  have^never  deigned  to  illustrate  br£a^lc:;i-tSf,rs'rf:rrr;:^ 


I 


.r., 


fj  ■ 


490 


PRINTING  MACHINE. 


of  Aikwright,  yet  nothing  in  the  whole  compass  of  art  deserves  it  so  well ;  and  though 
perfectly  aware  that  revolvency  is  the  leading  law  in  the  system  of  the  universe,  they  have 
never  thought  of  showing  the  workman  that  this  was  also  the  true  principle  of  every 
automatic  machine. 

These  remarks  seem  to  be  peculiarly  applicable  to  book-printing,  an  art  invented  for 
the  honor  of  learning  and  the  glory  of  the  learned,  though  they  have  done  nothing  for 
its  advancement ;  yet  by  the  overruling  bounty  of  Providence  it  has  eventually  served  as 
the  great  teacher  and  guardian  of  the  whole  family  of  man. 

It  has  been  justly  observed  by  Mr.  Cowper,  in  his  ingenious  lecture,*  that  no  improve- 
ment had  been  introduced  in  this  important  art,  from  its  invention  till  the  year  1798,  a 
period  of  nearly  350  years.  In  Dr.  Dibdin's  interesting  account  of  printing,  in  the 
Bibliographical  Decameron,  may  be  seen  representations  of  the  early  printing-presses, 
which  exactly  resemble  the  wooden  presses  in  use  at  the  present  day.  A  new  era  has, 
however,  now  arrived,  when  the  demands  for  prompt  circulation  of  political  intelligence 
require  powers  of  printing  newspapers  beyond  the  reach  of  the  most  expeditious  hand 
press  work. 

For  the  first  essential  modification  of  the  old  press,  the  world  is  indebted  to  the  late 
Earl  Stanhope,  f  His  press  is  formed  of  iron,  without  any  wood  ;  the  table  upon  which 
the  form  of  types  is  laid,  as  well  as  the  platen  or  surface  which  immediately  gives  the 
impression,  is  of  cast  iron,  made  perfectly  level ;  the  platen  being  large  enough  to 
print  a  whole  sheet  at  one  pull.  The  compression  is  applied  by  a  beautiful  combination 
of  levers,  which  give  motion  to  the  screw,  cause  the  platen  to  descend  with  progressively 
increasing  force  till  it  reaches  the  type,  when  the  power  approaches  the  maximum ; 
upon  the  infinite  lever  principle,  the  power  being  applied  to  straighten  an  obtuse-angled 
jointed  lever.  This  press,  however,  like  all  its  flat-faced  predecessors,  does  not  act  by  a 
continuous,  but  a  reciprocating  motion,  and  can  hardly  be  made  automatic  ;  nor  does  it 
much  exceed  the  old  presses  in  productiveness,  since  it  can  turn  ofl'  only  250  impressions 
per  hour. 

The  first  person  who  publicly  projected  a  self-acting  printing-press,  was  Mr, 
William  Nicholson,  the  able  editor  of  the  Philosophical  Journal,  who  obtained  a  patent 
in  1790-1,  for  imposing  types  upon  a  cylindrical  surface;  this  disposition  of  types, 
plates,  and  blocks,  being  a  new  invention  (see  Jig.  1172.);  2,  for  applying  the  ink  upon 
the  surface  of  the  types,  &c.,  by  causing  the  surface  of  a  cylinder  smeared  with  the 
coloring-matter  to  roll  over  them ;  or  else  causing  the  types  to  apply  themselves  to 
the  said  cylinder.  For  the  purpose  of  spreading  the  ink  evenly  over  this  cylinder,  he 
11Y2  proposed  to  apply  three  or  more  distributing 

rollers  longitudinally  against  the  inking  cy- 
linder, so  that  they  might  be  turned  by  the 
motion  of  the  latter.  3.  "  I  perform,"  he 
says,  "all  my  impressions  by  the  action  of  a 
cylinder,  or  cylindrical  surface;  that  is,  I 
cause  the  paper  to  pass  between  two  cylinders, 
one  of  which  has  the  form  of  types  attached 
to  it,  and  forming  part  of  its  surface;  and 
the  other  is  faced  with  cloth,  and  serves  to 
Nicholson's  for  Nicholson's  for  press  the  paper  SO  as  to  take  oflT  an  impres- 

archedtyi>e.  common  type.  sion    of   the    color    previously    applied;     or 

otherwise  I  cause  the  form  of  types,  previously  colored,  to  pass  in  close  and  successive 
contact  with  the  paper  wrapped  round  a  cylinder  with  woollen."  rSee  fies.  1172  and 
1173.)$  V       ^6 

In  this  description  Mr.  Nicholson  indicates  pretty  plainly  the  principal  parts  of 
modern  printing  machines ;  and  had  he  paid  the  same  attention  to  any  one  part  of  his 
invention  which  he  fruitlessly  bestowed  upon  attempts  to  attach  types  to  a  cylinder,  or 
had  he  bethought  himself  of  curving  stereotype  plates,  which  were  then  beginning  to  be 
talked  of,  he  would  in  all  probability  have  realized  a  working  apparatus,  instead  of 
scheming  merely  ideal  i)lans. 

The  first  operative  printing  machine  was  undoubtedly  contrived  by,  and  constructed 
under  the  direction  of,  M.  KOnig,  a  clockmaker  from  Saxony,  who,  so  early  as  the  year 
1804,  was  occupied  in  improving  printing-presses.  Having  failed  to  interest  the  con- 
tinental printers  in  his  views,  he  came  to  London  soon  after  that  period,  and  submitted 
his  plans  to  Mr.  T.  Bensley,  our  celebrated  printer,  and  to  Mr.  R.  Taylor,  now  one  of 
tke  editors  of  the  Philosophical  Magazine. 

♦  On  the  recent  improvements  in  printini?.  first  delivered  at  the  Royal  Institution,  February  22,  182b 

1  If  d  Stanhope  is  the  only  man  of  learning  whose  name  figures  in  the  annals  of  typography. 

t  The  black  parts  in  these  httle  diagrams,  913—922,  indicate  the  inking  apparatus  ,-  the  diagonal  lines  tha 

^rlinders  upon  which  the  paper  to  be  printed  is  applied  ;  the  perpendicular  lines,  the  plates  or  types  •  «iid 

the  arrow*  show  the  track  pursued  by  the  sheet  of  paper. 


PRINTING  MACHINJK. 


4M 


These  gentlemen  afforded  Mr.  Konig  and  his  assistant  Bauer,  a  German  mechanic, 
liberal  pecuniary  support.  In  181 1,  he  obtained  a  patent  for  a  method  of  working  a  com- 
mon hand-press  by  power;  but  after  much  expense  and  labor  he  was  glad  to  renounce 
the  scheme.  He  then  turned  his  mind  to  the  use  of  a  cylinder  for  communicating  the 
pressure,  instead  of  a  flat  plate;  and  he  finally  succeeded,  some  time  before  the  28th  No- 
Tember,  1814,  in  completing  his  printing  automaton  ;  for  on  that  day  the  editors  of  the 
Times  informed  their  readers  that  they  were  perusing  for  the  first  time  a  newspaper  print- 
ed by  steam-impelled  machinery ;  it  is  a  day,  therefore,  which  wUl  be  ever  memorable  ia 
the  annals  of  typography. 

In  that  machine  the  form  of  type  was  made  to  traverse  horizontally  under  the  pressure 
cylinder,  with  which  the  sheet  of  paper  was  held  in  close  embrace  by  means  of  a  series 

fljhj^  of  endless  tapes.     The  ink  was  placed  in  a  cylindrical  box, 

^  from  which  it  was  extnided  by  means  of  a  powerful  screw,  de- 

^^  ^f  pressing  a  well-fitted  piston;    it  then  fell  between  two  iron 

^1L     /^S^  rollers,  and  was  by  their  rotation  transferred  to  several  other 

•  •     WmAk^     subjacent  rollers,  which   had   not  only  a  motion  round  their 
w"©    ^^P^        ^^^^'^  ^"*  ^"^   alternating   traverse  motion    (endwise).      This 
Limrnii  system  of  equalizing  rollers  terminated  in  two  which  applied 

Konig's  single,  for  one         the  ink  to  the  types.     (See^g.  1174.)  This  plan  of  inking  evi- 
side  of  tho  sheet.  dently  involved  a  rather  complex  mechanism,  was  hence  diflSicult 

to  manage,  and  sometimes  required  two  hours  to  get  into  good  working  trim.     It  has  been 
superseded  by  a  happy  invention  of  Mr.  Cowper,  to  be  presently  described. 

In  order  to  obtain  a  great  many  impressions  rapidly  from  the  same  form,  a  paper-con- 
ducting  cylinder  (one  embraced  by  the  paper)  was  mounted  upon  each  side  of  the  inkin* 
apparatus,  the  form  being  made  to  traverse  under  both  of  them.  This  double-action  ma' 
chine  threw  ofi"  1100  impressions  per  hour  when  first  finished;  and  by  a  subsequent  im- 
provement, no  less  than  1800. 
Mr.  Konig's  next  feat  was  the  construction  of  a  machine  for  printing  both  sides  of 


1175 


Konig's  double,  for  both  sides  of  the  sheet. 


the  newspaper  at  each  complete  tra- 
verse of  the  forms.  This  resembled 
two  single  machines,  placed  with  their 
cylinders  towards  each  other,  at  a  dis- 
tance of  two  or  three  feet;  the  sheet 
was  conveyed  from  one  paper  cylinder 
to  another,  as  before,  by  means  of  tapes  ; 
the  track  of  the  sheet  exactly  resembled 
the  letter  S  laid  horizontally,  thus,    co; 


and  the  sheet  was  turned  over  or  reversed  in  the  course  of  its  passa-e.  At  the  first 
paper  cylinder  it  received  the  impression  from  the  first  form,  and  at  the  second  it  re- 
ceived It  from  the  second  form;  whereby  the  machine  could  print  750  sheets  of  book 
letler-press  on  both  sides  m  an  hour.     This  new  register  apparatus  was  erected  for  Mr. 

r  r'.\"  ^^^r^""^  ^^^h  ^^'""^  *^^  ''"^y  machine  made  by  Mr.  Kunig  for  printing 
npon  both  sides.     See^g.  1175.  =         r  s 

Messrs.  Donkin  and  Bacon  had  for  some  years  previous  to  this  date  been  busily 
engaged  with  printing  machines,  and  had  indeed,  in   1813,  obtained  a  patent  for  an 
11^®  apparatus,  in  which  the  types  were  placed  upon  the  sides  of  a  re- 

vovmg  prism ;  the  ink  was  applied  by  a  roller,  which  rose  and 
lell  with  the  eccentricities  of  the  prismatic  surface,  and  the  sheet 
was  wrapped  upon  another  prism  fashioned  so  as  to  coincide  with 
the  eccentricities  of  the  type  prism.  One  such  machine  was 
erected  for  the  University  of  Cambridge.  (See  ^g.  1176.)  It  was  a 
Deautilul  specimen  of  ingenious  contrivance  and  good  workman, 
snip.  1  hough  It  was  found  to  be  too  complicated  for  common 
operatives  and  defective  in  the  mechanism  of  the  inking  process ; 

«r«,i,    ««    T.-     1      •J^'^'^f^^^^^^'^^o^  the  first  time  the  elastic  inking  rollers,  composed 
of  glue  combmed  with  treacle,  which  alone  constitute  one  of  the  finest  inventi™^^^ 
modern  typography      In  Konig's  machine  the  rollers  were  of  metal  covered  w^tMeather 
and  never  answered  their  purpose  very  well  i^niuer. 

Before  proceeding  further  I  may  state  thit  the  above  elastic  composition,  which  re- 
scmWes  caoutchouc  not  a  little,  but  is  not  so  firm,  is  made  by  dissolving  with  heatTn  tJ^ 

^Id  wa?er  '^  '  °"'  '"""'^  "^  ^""^  ^^"^'  P^^^^^"^^^  ^^^^^^  during  a  nightln 

In  the  year  1815,  Mr.  Cowper  turned  his  scientific  and  inventive  mind  to  the  subject 
IX-'fll^  machines,  and  has  smce,  in  co-operation  with  his  partner,  Mr.  Applegith 
carried  them  to  an  unlooked-for  degree  of  perfection.     In  1815  Mr.  Cowper  obtain«l 
a  patent  for  curving  stereotype  plates,  for  the  purpose  of  fixing  them  oS  a  cvliidw 


Pookin  and  Bacon's 
for  type. 


M 


\ 


•    f 


492 


PRINTING  MACHINE. 


Several  machines  so  mounted,  capable  of  printing  1000  sheets  per  hour  upon  both 
•ides,  are  at  work  at  the  present  day ;   twelve  machines  on  this  principle  having  been 


1177 


1178 


».-♦ 


made  for  the  Di- 
rectors of  the 
Bank  of  Eng- 
land a  short  time 
previous  to  their 
re-issuing  gold. 
See  figs.  1177. 
and  1178. 


Cowper's  single,  for  curred  Cowper's  double,  for  both  sides  of  the 

stereotype.  sheet.  ^^.^, 

It  deserves  to  be  remarked  here,  that  the  same  object  seems  to  have  occupied  the 
attention  of  Nicholson,  Donkin,  Bacon,  and  Cowper ;  viz.,  the  revolution  of  the  form 
of  type3.  Nicholson  sought  to  effect  this  by  giving  to  the  shank  of  a  type  a  shape  like  the 
stone  of  an  arch;  Donkin  and  Bacon  by  attaching  types  to  the  sides  of  a  revolving 
pnsm;  and  Cowper,  more  successfully,  by  curving  a  stereotype  plate.  (See /^.  1177.) 
In  these  machines  Mr.  Cowper  places  two  paper  cylinders  side  by  side,  and  against 
each  of  them  a  cylinder  for  holding  the  plates ;  each  of  these  four  cylinders  is  about  two 
feet  in  diameter.  Upon  the  surface  of  the  stereotype-plate  cylinder,  four  or  five  inking 
rollers  of  about  three  inches  in  diameter  are  placed  ;  they  are  kept  in  their  position  by 
a  frame  at  each  end  of  the  said  cylinder,  and  the  axles  of  the  rolitr*!  rest  in  vertical  slots 
of  the  frame,  whereby,  having  perfect  freedom  of  motion,  they  act  by  their  gravity  alone,  and 
require  no  adjustment. 

The  frame  which  supports  the  inking  rollers,  called  the  wavmg-frame,  k  attached  by 
hinges  to  the  general  framework  of  the  machine;  the  edge  of  the  stereotype-plate  cylin- 
der is  indented,  and  rubs  against  the  waving-frame,  causing  it  to  vibrate  to  and  fro,  and 
consequently  to  carry  the  inking  rollers  with  it,  so  as  to  give  them  an  unceasing  traverse 
movement.  These  rollers  distribute  the  ink  over  three  fourths  of  the  surface  of  the 
cylinder,  the  other  quarter  being  occupied  by  the  curved  stereotype  plates.  The  ink  is 
contained  in  a  trough,  which  stands  parallel  to  the  said  cylinder,  and  is  formed  by  a 
metal  roller  revolving  against  the  edge  of  a  plate  of  iron ;  in  its  revolution  it  gets 
covered  with  a  thin  film  of  ink,  which  is  conveyed  to  the  plate  cylinder  by  a  distributing 
roller  vibrating  between  both.  The  ink  is  diffused  upon  the  plate  cylinder  as  before 
described  ;  the  plates  in  passing  under  the  inking  rollers  become  charged  with  the  colored 
varnish  ;  and  as  the  cylinder  continue?  to  revolve,  the  plates  come  into  contact  with  a 
sheet  of  paper  on  the  first  paper  cylinder,  which  is  then  carried  by  means  of  tapes  to  the 
second  paper  cylinder,  where  it  receives  an  impression  upon  its  opposite  side  from  the  plates 
upon  the  second  cylinder. 

Thus  the  printing  of  the  sheet  is  completed.  Though  the  above  machine  be  applicable 
only  to  stereotype  plates,  it  has  been  of  general  importance,  because  it  formed  the  foun- 
dation of  the  future  success  of  Messrs.  Cowper  and  Applegalh's  printing  machinery,  by 
showing  them  the  best  method  of  serving  out,  distributing,  and  applying  the  colored  varnish 
to  the  types. 

In  order  to  adapt  this  method  of  inking  to  a  flat  type-form  machine,  it  was  merely 
requisite  to  do  the  same  thing  upon  an  extended  flat  surface  or  table,  which  had 
been  performed  upon  an  extended  cylindrical  surface.  Accordingly,  Messrs.  Cowper 
and  Applegath  constructed  a  machine  for  printing  both  sides  of  the  sheets  from  type 
including  the  inking  apparatus,  and  the  mode  of  conveying  the  sheet  from  the  one  paper 
cylinder  to  the  other,  by  means  of  drums  and  tapes.  It  is  highly  creditable  to  the  scien- 
tific judgment  of  these  patentees,  that  in  new  modelling  the  printing  machine  they  dis- 
pensed with  forty  wheels,  which  existed  in  Mr.  Konig's  apparatus,  when  Mr.  Bensley  re- 
quested them  to  apply  their  improvements  to  it 

The  distinctive  advantages  of  these  machines,  and  which  have  not  hitherto  been 
equalled,  are  the  uniform  distribution  of  the  ink,  the  equality  as  well  as  delicacy 
with  which  it  is  laid  upon  the  types,  the  diminution  in  its  expenditure,  amounting  to 
1^  J  1179  one  half  upon  a  given  quantity  of  letter-press,  and  the  facility  with 
^     it  which  the  whole  mechanism  is  managed.       The  band  inking-roller 

and  distributing-table,  now  so  common  in  every  printing-office  in  Eu- 
rope and  America,  is  the  invention  of  Mr.  Cowper,  and  was  specified 
in  his  patent.  The  vast  superiority  of  the  inking  apparatus  in  his  ma- 
chines, over  the  balls  used  of  old,  induced  him'  to  apply  it  forthwith 
to  the  common  press,  and  most  successfully  for  the  public ;  but  with 
little  or  no  profit  to  the  inventor,  as  the  plan  was  unceremoniously  in- 
fringed throughout  the  kingdom,  by  such  a  multitude  of  printers,  whether 
rich  or  poor,  as  to  render  all  attempts  at  reclaiming  his  rights  by  prose- 
cution hopeless.    See  fig.  1179. 

To  construct  a  printing  machine  which  shall  throw  off  two  sides  at  a 
time  with  exact  register,  that  is,  with  the  second  side  placed  precisely  upon  the  back  of  the 

66 


Cowper's  inking 
table  and  roller. 


PRINTING  MACHINE. 


493 


first,  is  a  very  difficult  problem,  which  was  first  practically  solved  by  Messis.  Applegati 
and  Cowper.  It  is  comparatively  easy  to  make  a  machine  which  shall  print  the  one  side 
of  a  sheet  of  paper  first,  and  then  the  other  side,  by  the  removal  of  one  form,  and  the 
introduction  of  another;  and  thus  far  did  Mr.  Konig  advance.  A  correct  register 
requires  the  sheet,  after  it  has  received  its  first  impression  from  one  cylinder,  to  travel 
1180  1181 


Applegath  and  Cowper's  sing^le.  Applegath  and  Cowper's  double. 

round  the  peripheries  of  the  cylinders  and  drums,  at  such  a  rate  as  to  meet  the  typef 
of  the  second  side  at  the  exact  point  which  will  ensure  this  side  falling  with  geome- 
trical nicety  upon  the  back  of  the  first.  For  this  purpose,  the  cylinders  and  drums 
must  revolve  at  the  very  same  speed  as  the  carriage  underneath  ;  hence  the  least  incor- 
rectness in  the  workmanship  will  pro<luce  such  defective  typography  as  will  not  be 
endured  in  book-printing  at  the  present  day,  though  it  may  be  tolerated  in  newspapers. 
An  equable  distribution  of  the  ink  is  of  no  less  importance  to  beautiful  letter-press.  See 
figs.  1180,  1181. 

The  machines  represented  in  _^g».  1183,  84,  85.  are  different  forms  of  those  which  have 
been  patented  by  Messrs.  Applegath  and  Cowper.  That  shown  in  figs.  1182,  and  84  prints 
both  sides  of  the  sheet  during  its  passage,  and  is  capable  of  throwing  off  nearly  1000 
finished  sheets  per  hour.  The  moistened  quires  of  blank  paper  being  piled  upon  a 
table  A,  the  boy,  who  stands  on  the  adjoining  platform,  takes  up  one  sheet  after  another, 
and  lays  them  upon  the  feeder  b,  which  has  several  linen  girths  passing  across  its  sur- 
face, and  round  a  pulley  at  each  end  of  the  feeder ;  so  that  whenever  the  pulleys  begin 
to  revolve,  the  motion  of  the  girths  carries  forward  the  sheet,  and  delivers  it  over  the 
entering  roller  e,  where  it  is  embraced  between  two  series  of  endless  tapes,  that  pass 
round  a  series  of  tension  rollers.  These  tapes  are  so  placed  as  to  fall  partly  between, 
and  partly  exterior  to,  the  pages  of  the  printing ;  whereby  they  remain  in  close  contact 
with  the  sheet  of  paper  on  both  of  its  sides  during  its  progress  through  the  machine.  The 
paper  is  thus  conducted  from  the  first  printing  cylinder  f,  to  the  second  cylinder  g, 
without  having  the  truth  of  its  register  impaired,  so  that  the  coincidence  of  the  two 
pages  is  perfect.  These  two  great  cylinders,  or  drums,  are  made  of  cast  iron,  turned  per- 
fectly true  upon  a  self-acting  lathe  ;♦  they  are  clothed  in  these  parts,  corresponding  to  the 
typographic  impression,  with  fine  woollen  cloth,  called  blankets  by  the  pressmen,  and 
revolve  upon  powerful  shafts  which  rest  in  brass  bearings  of  the  strong  framing  of  the 

1182 


machine.  These  bearings,  or  plummer  blocks,  are  susceptible  of  any  de«'ree  of  adm^t- 
ment,  by  set  screws.  The  drums  h  and  i  are  made  of  wood ;  they  serve  to  conduct  th* 
■heet  evenly  from  the  one  printing  cylinder  to  the  other.  conduct  the 

One  series  of  tapes  commences  at  the  upper  part  of  the  entering  drum  e,  proceeds  in 
eontact  with  the  right-hand  side  and  under  surface  of  the  printing  cylinder  f,  passw 

MwcheSEer!''*''""'^  '"'^^  ""'^  ^^*'"""' '''''  *''™°^  °^  '^""^  «^*"*  '^^»°^«"  ^  Me«x..  Cowper'.  factory  tf 


I 


494 


PRINTING  MACHINE. 


U 


next  over  the  carrier-drum  h,  and  under  the  carrier-drum  i ;   then  encompassing  tht 
*eft-hand  side  and  under  portion  of  the  priming  drum  g,  it  passes  in  contact  with  the 


small  tension  rollers  a,  6,  c,  d,  ^g.  1184,  and  finally  arrives  at  the  roller  e,  which  may 
be  called  the  commencement  of  the  one  series  of  endless  tapes.  The  other  series  may 
be  supposed  to  commence  at  the  roller  h ;  it  has  an  equal  number  of  tapes,  and  cor- 
responds with  the  former  in  being  placed  upon  the  cylinders  so  that  the  sheets  of  paper 
may  be  held  securely  between  them.  This  second  series  descends  from  the  roller  h, 
^g.  1184,  to  the  entering  drum  e,  where  it  meets  and  cpincides  with  the  first  series  in 
«uch  a  way  that  both  sets  of  tapes  proceed  together  under  the  printing  cylinder  f,  over  h, 
under  i,  and  round  g,  until  they  arrive  at  the  roller  i,  fig.  1182  where  they  separate,  after 
having  continued  in  contact,  except  at  the  places  where  the  sheets  of  paper  are  held 
between  them.  The  tapes  descend  from  the  roller  i,  to  a  roller  at  k,  and,  after  passing  in 
contact  with  rollers  at  Z,  m,  w,  they  finally  arrive  at  th^  roller  h,  where  they  were  supposed 
to  commence.  Hence  two  series  of  tapes  act  invariably  in  contact,  without  the  least 
mutual  interference,  as  may  be  seen  by  inspection  of  the^g«.  1182,  1183,  1184. 

The  various  cylinders  and  drums  revolve  very  truly  by  means  of  a  system  of  toothed 
wheels  and  pinions  mounted  at  their  ends.  Two  horizontal  forms  of  types  are  laid  at  a 
certain  distance  apart  upon  the  long  carriage  m,  adjoining  to  each  of  which  there  is  a  fiat 
metallic  plate,  or  inking  table,  in  the  same  plane.  The  common  carriage,  bearing  its  two 
foiins  of  type  and  two  inking  tables,  is  moved  backwards  and  forwards,  from  one  end  of 
the  printing  machine  to  the  other,  upon  rollers  attached  to  the  frame-work,  and  in  its 
traverse  brings  the  types  into  contact  with  the  sheet  of  paper  clasped  by  the  tapes  round 
the  surfaces  of  the  printing  cylinders.  This  alternate  movement  of  the  carriage  is  pro- 
duced by  a  pinion  working  alternately  into  the  opposite  sides  of  a  rack  under  the  table. 
The  pinion  is  driven  by  the  bevel  wheels  k. 

The  mechanism  for  supplying  the  ink,  and  distributing  it  over  the  forms,  is  one  of  the 
most  ingenious  and  valuable  inventions  belonging  to  this  incomparable  machine,  and  is 
so  nicely  adjusted,  that  a  single  grain  of  the  pigment  may  sufl5ce  for  printing  one  side 
of  a  sheet.  Two  similar  sets  of  inking  apparatus  are  provided ;  one  at  each  end  of  the 
machine,  adapted  to  ink  its  own  form  of  type.  The  metal  roller  l,  called  the  ductor 
roller,  as  it  draws  out  the  supply  of  ink,  has  a  sl6w  rotatory  motion  communicated  to  it 
by  a  catgut  cord,  which  passes  round  a  small  pulley  upon  the  end  of  the  shaft  of  the 
printing  cylinder  g.  A  horizontal  plate  of  metal,  with  a  straight-ground  edge,  is 
adjusted  by  set  screws,  so  as  to  stand  nearly  in  contact  with  the  ductor  roller.  This  plate 
lias  an  upright  ledge  behind,  converting  it  into  a  sort  of  trough  or  magazine,  ready  to 
impart  a  coating  of  ink  to  the  roller,  as  it  revolves  over  the  table.  Another  roller, 
covered  with  elastic  composition  (see  supra),  called  the  vibrating  roller,  is  made  to  travel 
between  the  ductor  roller  and  the  inking  table  ;  the  vibrating  roller,  as  it  rises,  touches 
ihe  ductor  roller  for  an  instant,  abstracts  a  film  of  ink  from  it,  and  then  descends  to 
transfer  it  to  the  table.  There  are  3  or  4  small  rollers  of  distribution,  placed  somewhat 
diagonally  across  the  table  at  m,  (inclined  only  2  inches  from  a  parallel  to  the  end  of  the 
frame,)  furnished  with  long  slender  axles,  resting  in  vertical  slots,  whereby  they  are 
left  at  liberty  to  revolve  and  to  traverse  at  the  same  time;  by  which  compound  movement 
they  are  enabled  to  efface  all  inequality  in  the  surface  of  the  varnish,  or  to  effect  a  per- 


PRINTING  MACHINE.  495 

e  a  or  4  proper  mkmg  rollers  n.  Jig.  ii83,  imparts  to  them  a  miifon. 


^*t- 


I 


496 


PRINTING  MACHINE. 


't  i 


film  of  ink,  to  be  immediately  transferred  by  them  to  the  types.  Hence  each  time  that 
the  forms  make  a  complete  traverse  to  and  fro,  which  is  requisite  for  the  printing  of  every 
sheet,  they  are  touched  no  less  than  eight  times  by  the  inking  rollers.  Both  the  distribu- 
ting and  inking  rollers  turn  in  slots,  which  permit  them  to  rise  and  fall  so  as  to  bear  with 
their  whole  weight  upon  the  inking  table  and  the  form,  whereby  they  never  stand  in  need 
of  any  adjustment  by  screws,  but  are  always  ready  for  work  when  dropped  into  their 
respective  places. 

Motion  is  given  to  the  whole  system  of  apparatus  by  a  strap  from  a  steam  engine  goini? 
round  a  pulley  placed  at  the  end  of  the  axle  at  the  back  of  the  frame ;  one  steam-horse 
power  being  adequate  to  drive  two  double  printing  machines ;  while  a  single  machine 
may  be  driven  by  the  power  of  two  men  acting  upon  a  fly-wheel.  In  Messrs.  Clowes' 
establishment,  in  Stamford-street,  two  five-horse  engines  actuate  nineteen  of  the  above 
described  machines. 

The  operation  of  printing  is  performed  as  follows  : — See  fig.  1185. 
The  sheets  being  carefully  laid,  one  by  one,  upon  the  linen  girths,  at  the  feeder  b,  the 
rollers  c  and  d  are  made  to  move,  by  means  of  a  segment  wheel,  through  a  portion  of  a 
revolution.  This  movement  carries  on  the  sheet  of  paper  sufficiently  to  introduce  it  be- 
tween the  two  series  of  endless  tapes  at  the  point  where  they  meet  each  other  upon  the 
entering  drum  e.  As  soon  as  the  sheet  is  fairly  embraced  between  the  tapes,  the  rollers 
c  and  D  are  drawn  back,  by  the  operation  of  a  weight,  to  their  original  position,  so  as 
to  be  ready  to  introduce  another  sheet  into  the  machine.  The  sheci.  advancing  between 
the  endless  tapes,  applies  itself  to  the  blanket  upon  the  printing  cylinder  f,  and  as  it 
revolves  meets  the  first  form  of  types,  and  receives  their  impression ;  after  being  thus 
printed  on  one  side,  it  is  carried,  over  h  and  under  i,  to  the  blanket  upon  the  printing  cy- 
linder G,  where  it  is  placed  in  an  inverted  position ;  the  printed  side  being  now  in  contact 
with  the  blanket,  and  the  white  side  being  outwards,  meets  the  second  form  of  types  at  the 
proper  instant,  so  as  to  receive  the  second  impression,  and  get  completely  printed.  The 
perfect  sheet,  on  arriving  at  the  point  t,  where  the  two  series  of  tapes  separate,  is  tossed 
GUI  by  centrifugal  force  into  the  hands  of  a  boy. 

The  diagram,  fig.  1185  shows  the  arrangement  of  the  tapes,  agreeably  to  the  preced- 
ing description;  the  feeder  b,  with  the 
rollers  c  and  d',  is  seento  have  an  independent 
endless  girth. 

The  diagram,  fig.  1186.  explains  the 
structure  of  the  great  machine  contrived 
by  Messrs.  Applegath  and  Cowper  for 
printing  the  Times  newspaper.  Here 
there  are  four  places  to  lay  on  the  sheets, 
and  four  to  take  them  off;  consequently, 
the  assistance  of  eight  lads  is  required, 
p,  p,  p,  p,  are  the  four  piles  of  paper ; 
r,  F,  F,  F,  are  the  four  feeding-boards  ;  e,  e,  e,  e,  are  the  four  entering  drums,  upon  which 
the  sheets  are  introduced  between  the  tapes  t,  t,  t,  t,  whence  they  are  conducted  to  the 

1186  P 


PRINTING  MACHINE. 


1185 


497 

four  printing  cylinders  I   2  S  4        '♦»,#• 

which  one  ia  placed  at 'each 'end  of  the  fo™"™-!?'  'T'  ''  '■"•*  '""  '"•"■"«  '"l-Krf 
•bove  described,  with  the  addition  of  tw^'  .1?  i  •  ,"?  "PP*™'"'  ■»  ''i-ilar  to  th2 
receive  their  ink  from  the  ini>iW  t»U«  t?  ^"^"^  '""""S  ■•""«>•*  "^  which  liliewiM 
r.»  and  fall  about  half  an  Sih?  the  fet  2^  T^i'"^  ''^"■"''"  >•  2- »•  •••  »■•«  ™^I  to 
and  fourth  The  form  of  t™',  .^pls'n-  fro^f  .""""''''''•"''""^'y'  ■"  »'«'  ""e  ^nd 
returning  from  b  to  a,  it  prints  shee?r»tf.„^^  I','  P"°'»  sheets  at  I  and  8  •  in 
to  give  the  imnreesion.  anTriles  to  ^rmit  ??e  f^^  J?""  ""'  ^^^'"^''  «lton,atel/felS 

Zt\  'J'?KP""J'''e  cvlitlder,  and^S  uptarda  to  ;  '^  '^^  '»P*'  '•  ^ 
parted,  and  the  sheet  falls  into  the  bands  S  »K?»  j  fv"'  "■  »■  ^"""e  tbe  tapes  »• 
18  so  perfectly  equipped,  that  h^^.r^'i^tl^Tt'^J^^""'^^'"^^'^^ 
the  form  «  brought  into  the  machine^ZS    The  "^Jd  ^f  v'"?'"  '""  ■"'■"■t''  «f^ 

last  few  years,  ^C^Z  rmenrStm  wlJ'*  T^."'  «>«  ^''-  "-tU  the 
dered  it  necessary  to  provide  a  mXe  wui  "X"*  ^T^^  "P"-  "»  powers  rei 
the  paper  per  hour.     ''  "™"'°  """<*  """W  "or*  off  at  Ua.t  10,000  co^^ 

whaf  r^tef^aTru^dltC^  r ""'■^  •'  »  "----y  ^  observe  that 
one  by  one  t^  the  fingerWf  The  Machine  bv.„P?r''^'"  '«P™'*d  must  iTdel?™^ 
machine,  they  are  carried  through  "irktedhf"  V  ^•'*"  ^^^  "^  *°  «  tU 
the  case  of  sheets  so  laree  as  th<vi»^,f^  printed  by  self-acting  machinerv  Bnt  i- 
delivered  with  the  necesJ^y^/e'cS^^^^^^  ^^  ^o-<*  that  the^^^o.^oTlS 

Not  inTh?'*'' ""'  twentj-fi^e'^per  minui  S"  at  thVr«?  '"^^t/^Pid  rate  than  twi 

cv^^dfr«  to  S^°^\^,  P'^*  ^t  '^^  ^-^te  of  1^000  nerH^.'"'  ^^00  sheets  per  hour, 
cylinders  to  place  which  so  as  to  be  acted  ,,L1.  k       P      **°"'*'  ^^uld  require  seven 

Slffi'cuir'"^'  fra^ne.  in  the  manneTalreardetrlb/fT  ^^  °^«^'°^  llternTei; 
difficul  les  almost  msurmountable.  ^  described,  would  present  mechanic^ 

the  drum,  bat  the  breadth  of  ?k/^i'  *^®  ^^^^^^  ""^  ^^^c^  coincides  with  Ikl l   ^    ^ 
^url       P"°*!°^  ^'^hxne  measures  200  I  nni  ;.  •     ^  «rcumference  of  this  drum  in 

''^f--rcenT4ir~££^^^^^^^^^ 

Ihis  drum  is  surrounded  hv  ^.v^ilf      r  j    ®*  *"®  ^^P^  and  inking  tablps  * 

.t^oftKrilTdTSSSh"^^^^^^^^^ 

Tiously  inked,  and  ead,  of   he  ^i^ht  cvliL'"^''*  "^"f-'^*''-  ""d  if  the  t^^^were  ^ 

"Beside  the  eight  paper cvlindpra  Of      i       »  f  t^^  w 

•re^U^dtwoduotorroUet^  ^eseZfcK^irr^^-^^ 


498 


PRINTING  MACHINE. 


PRUSSIAN  BLUE. 


49ft 


'■ « 


TOirs  placed  above  them.  As  the  inking  table  attached  to  the  revolving  drum  passes 
each  of  these  diictoi-  rollerSi  it  receives  from  them  a  coating  of  ink.  It  next  encounters 
the  inking  rollers  to  which  it  delivers  over  this  coating.  The  types  next,  by  the  con- 
tinued revolution  of  the  drum,  encounter  these  inking  rollers,  and  receive  from  them  a 
coating  of  ink,  after  which  they  meet  the  paper  cylinders,  upon  which  thev  are  im- 
pressed, and  the  printing  is  completed. 

"  Thus  in  a  single  revolution  of  the  great  central  drum  the  inking  table  receives  a 
Bijpply  eight  times  successively  from  the  ductor  rollers,  and  delivers  over  that  suddIv 
eight  times  successively  to  the  inking  rollers,  which,  in  their  turn,  deliver  it  eight  timei 
successively  to  the  faces  of  the  type,  from  which  it  is  conveyed  finally  to  the  eiehl 
sheets  of  paper  held  upon  the  eight  cylinders  by  the  tapes.  ^ 

"  Let  us  now  explain  how  the  eight  cylinders  are  supplied  with  paper.  Over  each  of 
them  IS  erected  a  sloping  desk,  h  h  &c  upon  which  a  stock  of  unprinted  paper  is 
deposited  Beside  this  desk  stands  the  "  layer  on,"  who  pushes  forward  the  paper,  sheet 
by  sheet,  towards  the  fingers  of  the  machine.  ^  ^    ' 

"These  fingers,  seizing  upon  it,  first  draw  it  down  in  a  vertical  direction  between  tapes 
m  the  eight  vertical  frames  until  its  vertical  edges  correspond  with  the  position  of  the 
form  of  type  on  the  printing  cylinder.  Arrived  at  this  position  its  vertical  motion  is 
stopped  by  a  self-acting  upparatus  provided  in  the  machine,  and  it  begins  to  move  hori- 
rontally,  and  It  IS  thus  carried  towards  the  printing  cylinder  by  the  tapes.  As  it  passes 
round  this  cylinder  it  is  impressed  upon  the  type,  and  printed.  It  is  then  carried  back 
horizontally  by  similar  tapes  on  the  other  side  of  the  frame,  until  it  arrives  at  another 
desk,  where  the  taker  off  awaits  it.  The  fingers  of  the  machine  are  there  disengagS 
from  it,  and  the  "  taker  off  receives  it,  and  disposes  it  upon  the  desk.  This  movement 
goes  on  without  interruption,  the  moment  that  one  sheet  descends  from  the  hands  of  the 
layer  on,  and  being  carried  vertically  downwards  begins  to  move  horizontally,  space  is 
left  for  another,  which  he  immediately  supplies,  and  in  this  manner  he  delivers  to  the 
machine  at  the  average  rate  of  two  sheets  every  five  second8,and  the  same  delivery  taking 


I 


M  ; 


ive'^seclndl^  ^^  ^^^  ^'^^^  cyKnders,  there  are  16  sheeta  deUvered  and  printed  eveiy 

"It  is  found  that  by  this  naachine  in  ordinary  work  between  10,000  and  11.000  per 
hour  can  be  printed;  but  with  very  expert  men  to  deliver  the  sheets,  a  stiU  Veat^r 
speed  can  be  attained  Indeed,  the  velocity  is  limited,  not  by  any  conations  aC  W 
the  machine,  but  by  the  power  of  the  men  to  deliver  the  sheets  to  it  ^ 

In  case  of  any  misdelivery  a  sheet  is  spoilt,  and  consequently,  the  effective  per- 
formance of  the  machme  is  iVired.  I^  however,  a  stiU  ^greater  speed  of  prfnt^g 
were  required,  the  same  description  of  machine,  without  changing  its  pkneip?f 
would  be  sufiicient  for  the  exigency;  it  would  be  necessary  that  the  types  should  £ 
surrounded  with  a  greater  number  of  printing  cylindei-s.  "^ 

"The  machine  which  was  erected  in  the  Exhibition,  the  property  of  Mr  Inffram. 
was  used  in  printing  the  Illustrated  London  News.  The  great  central  cylinder  ™S 
this  case  surrounded  by  only  four  printing  cylinders,  each  superintendei  by  two  men. 
«f  TL^T^       "^  V.  •  '^'''^.  that  these  surrounding  cylinders  and  rollers,  in  the  case 

of  Th^  Times  machine,  are  not  uniformly  distributed  round  the  great  central  drum  • 
they  are  so  arranged  as  to  leave  on  one  side  of  that  drum  an  open  space  equal  to  the 
width  of  the  type  form.  This  is  necessary  in  order  to  give  access  to  the  ty^e  form^ 
as  to  adjust  it.  ^*^     vi***  i»v 

-In  a  machine  where  the  number  of  type  cylinders  is  not  so  crowded  round  th« 
arum,  this  precaution  is  not  necessary. 

"One  of  the  practical  difficulties  which  Mr.  Applegath  had  to  encounter  in  the 
solution  of  the  prob  em,  which  he  has  so  successfully  effected,  arose  from  the  shock 
produced  to  the  machinery  by  reversing  the  motion  of  the  horizontal  frame  which  in 
the  old  machine  carried  the  tj^pe  form  and  inking  table,  a  moving  mass  which  weighed 
a  ton  1  This  frame  had  a  motion  of  88  mches  in  each  direction,  and  it  was  found  that 
such  a  weight  could  not  be  driven  through  such  a  space  with  safety  at  a  greater  rate 

tZ  ^htt  perTour  '''  "^"^"^^  "^^'  "^'^^  ^^  ^^--  P-^-^  Powe;t 

"Another  difficulty  in  the  construction  of  this  vast  piece  of  machinery  was  so  to 

regulate  the  self-acting  mechanism  that  the  impression  of  the  type  form  shouM^lwa^ 

be  made  m  the  centre  of  the  page,  and  so  that  the  space  upon  the  paper  occupted^y 

"  The  type  form  fixed  on  the  central  drum  moves  at  the  rate  of  10  inches  per  second, 
and  the  paperis  moved  in  contact  with  it  of  course  at  exactly  the  same  ratl^  Now  tf 
l^uJJVZ,'^  \  ^f""^"^  or  motion  of  a  sheet  of  paperf  it  arrive  at  the  pr?nW 
cylmder  l-70th  part  of  a  second  too  soon  or  too  late,  the  relative  position  of  thf 
colunins  will  vary  by  l-70th  part  of  70  inches-that  is  to  say.  by  one  inch.  In  that 
case  the  edge  of  the  printed  matter  on  one  side  would  be  an  inch  nearer  to  the  edge^f 
the  paper  than  on  the  other  side  This  is  an  incident  which  rarely  happens,  but  when 
t  does,  a  sheets  of  course,  is  spoi  t  In  fact,  the  waste  from  that  cause  is  conside^bly 
less  m  the  present  vertical  machine  than  in  the  former  less  powerful  horizontal  on^ 

thrinrl^'foffi  ^r'*'"^  f  ^'  ^°^^"^  '^"^"  ''  °^«^^  conducive  to  the  goodne^  of 
^e  work-for  the  type  and  engraving  are  only  touched  on  their  extreme  surface-Th^ 
the  horizontal  machme,  where  the  inking  rollers  act  by  gravity  •  also  anv  dii«t^«t!n 

upon^'the  flo^oT^'  "'^^'  ^^^°^^^^^  ^^  ^^^^^"^^  ^PoVZZii^ironlr^rol^^^ 

thlTl\f  teSl'^'  ^^'^^^  impressions  have  been  taken  without  stopping  to  brush 

J' The  principle  of  this  vertical  cylinder  machine  is  capable  of  ahnost  unlimited 
extension      Mr.  Applegath  offered  tlie  Royal  Commission  to  make  a  machinoT^ 
Great  Exhibition  which  with  no  rate  of  Motion  more  rapid  than  thaTof  AV?W 
^ommtn^To^kl^S''  ^'^^"^  ^''  ^^^••'  «''  ^^^^  ^^^^  ^^-^  between  two  UcW^ 
PRUSSIAN  BLU^  and    PRUSSIATE  OF  POTASH,  are   two  important  articles 
of  chemical  manufacture,  which  must  be  considered  together.     Thrfa^r^Us  caU^  by 
Enghsh  chemists,  Ferrocyanodide  of  iron,  the  Cyanure%rosoferHgt^o^ Ber^uS 
Msenblausaures  asenoxyd,  ov  eisen^yanur  +  eisekcyanu^  Germ^;  th!  second  il^^ 
Ferrocyanodide  of  potasszum  the  Cyanure  ferroso-potassique  of  BerzeUus;  iLL^u^ 
kalmm^cyanetsen^  cyankahum,ov  Blausaures  LenoxyduL-lcali,  GernT     ^**"^^'**"^ 
Prussian  blue  (^erW6/at^  Germ.,)  is  a  chemical  compound  of  iron  and  cyanogen. 
When  organic  matters  abounding  m  nitrogen,  as  dried  blood,  homs^  h^r^S^ 
hoofs  ot  animal  are  triturated  along  with  poUsh  in  a  strongly  ignited  iron  po?Tdark 
gray  mass  is  obtamed,  that  affords  to  water  the  liquor  origlially  called  li^vium^ 

•  The  Groat  ExhibiUon  and  London  in  1851,  reviewed  by  Dr.  Lardner,  Ac    London,  18S2. 

8S2 


60Q 


PRUSSIAN  BLUE. 


11 


t::     : 

'i  '       • 


and  has  for  its  ultimate  constituent^  Mtaii^,^m  fr^^      commeree,  prussiate  of  potash. 

h^/rL^Jic^^pSl^e^J't^^  ~i.?In?44^?f'  J^ttr/siro^- 

to  be  their  true  chemicarcois,k„,!f„n°''^''*^  '"«  P*"^!  b">  th?fet  aDoeal 

(26  X  2  +  4Crx2)  ,  the  sin,  bTinf iJr    !'  !  L       ^cyande  of  potassiui,  132,= 

The  crystUs  of  prusViate  „fZ«h  Ll  Slarl  r™  ""'"^  10  in  the  seale  of  equivalent, 
somewhat  bitterish  tastVXbte  in  4  „ZV  ".'"'"""J'if ''"'  "'^  «  sweetish  saliue  and 
water,  but  insoluble  in  alcS     TV.  Tt  1     ""'"■  ?'  *^  *"•'  """l  '"  '  !»«  of  boil'ne 

l«!ni"t?  "^""^'^  ''«™  °to.eIS:r,h.rrt":'lL'"^^^^^^  ""'  <"dinar;terapera.:re,! 
losing  their  form  or  cohprpni.*.  o«^  v        ^    ,         ""  ^^*  P^""  cent,  of  water  witimnt 


PRUSSIAN  BLUE. 


501 


Metallic  solutions. 
Antimony    -        .        . 

Bismum 

Cadmiam     -        _        . 

Cerium  (protoxyde") 
Cobalt         -        . 
Copper  (protoxyde)  - 

Do.    (peroxyde) 
Iron  (protoxyde) 

Do.     (peroxyde) 
Lead 

Manganese  (protoxyde) 
Manganese  (deutoxyde) 
Mercury  (protoxyde)   - 
Do      (peroxyde)      * 
Molybdenum 
Nickel  (oxyde) 

Palladium  (protoxyde) 
Silver  -  .  , 

Tantalum 
Tin  (protoxyde) 
Do.  (peroxyde) 
Uranium 
Zinc        -        . 


-  white.  C«Jo''ofP"«Pitate. 

-  white. 

-  white,  a  Ht.Ie  yellowish. 

-  white,  soluble  in  acids. 

-  green,  soon  turning  reddish-gray. 

-  white,  changing  to  red. 

-  brown-red. 

-  "^hite,  rapidly  turning  blue. 

-  dark  blue.  ^ 

-  white,  with  a  yellowish  cast. 

-  white,  turning  quickly  peach  or  blood-red. 

-  greemsh-gray. 

-  white. 

-  white,  turning  blue. 

-  dark  brown. 

-  white,  turning  greenish. 

-  green  (gelatinous.) 

-  white,  turning  brown  in  the  light. 

-  yellow,  dark  burned  color. 

-  white,  (gelatinous.) 

-  yeJlow,        do. 

-  red-brown. 
-            -  white. 

yttri:,^;3t^^^^^^^  or  earthy  salts,  except  that  of 

t^e  metal   thrown  lw„rw\"l^  f^'^^.^S^^^^^  with'cy'Sfo? 

cyanide  of  potassium  and  the  Deeuli«r^roi?-  ^i^  reciprocal  decomposition  of  the 
cipitate  from  the  sulphate  of ^op^Y  Tas  a  fine'Zn'  ^''^l'^"  '"  'J»^  ^«^"^^"-  The  pre! 
pigment;  but  it  is  somewhat  tSlrent  !n^fi,T"  T^«'>  *«d  has  been  used  as  a 
cipitate  from  the  peroxvde  s-ltf  ^/"      ?    ^  therefore  does  r.ot  cover  well.     The  Dre 

continent,  Paris  bire:X:fbrr2r^^^^^  P^"^-"  blue,  call  J'^the 

prussiate  of  peroxyde  of  iron ;  or  as'a  d^bu  ?  ^^^P^^jd  of  prussiate  of  protoxyde  and 
iron,  as  the  denomination  ^JnZfe^r^TfI^:Z''i^^  ^^  the  protoxyde  and  peroxyde  of 
may  be  therefore  stated  thus^  pms^^r^vH^^^-  *^^"?i^'-  ^"  '^"mbers,  its  composition 
peroxyde  of  iron,  30-79;  or  c^yTnogen  ifi??^^^  protoxyde  of  iron,  20-73" 

sent  its  constitution  when  it  isforS'bv  Zj- T.^  ^^'^^V^^^^^^  ^^'^^  ;  which  reprel 
sa  t  of  iron  that  contains  no  prSyde  ^  Tf  th?  •  ^"*' k  V^  '^'  ^'""'^^^'^  ^^  P^^ash  or  a 
Wit,  it  will  afford  a  precipitate,  at/m'pa  e  uV'Z^l  ?"'  ^^'/'^^^^  peroxydized  in  the 
swting  of  a  mixture  of  prussiate  of  Tro?oxvde  aJ  '^  '  •  ?'  ^r"^  ""^  ^  '^^  ^'''>  <^«^ 
white  cyanide  of  iron  (the  prussiate  of  the  pure  ^inJfT\^^  ^^'^^^'de.    In  fact,  the 

V       y  ic  oi  me  pure  protoxyde),  when  exposed  to  the  air  in  a 


moist  condition,  becomes,  as  above  stated,  dark  blue;  yet  the  new  combination  formed 
in  this  case  through  absorption  of  oxygen,  is  essentially  different  from  that  resulting  from 
the  precipitation  by  the  peroxyde  of  iron,  since  it  contains  an  excess  of  the  peroxyde  in 
addition  to  the  usual  two  cyanides  of  iron.  It  has  been  therefore  caUed  basic  Prussian 
Wiw,  and,  from  its  dissolving  in  pure  water,  solitble  Prussian  blue. 

Both  kinds  of  Prussian  blue  agree  in  being  void  of  taste  and  smell,  in  attracting 
humidity  from  thj  air  when  they  are  artificially  dried,  and  being  decomposed  at  a  heat 
above  d48   F.     The  neutral  or  insoluble  Prussian  blue  is  not  affected  by  alcohol;  the 
basic,  when  dissolved  in  water,  is  not  precipitated  by  that  liquid.     Neither  is  acted  upon 
by  dilute  acids ;  but  they  form  with  concentrated  sulphuric  acid  a  white  pasty  mass. 
From  which  they  are  again  reproduced  by  the  action  of  cold  water.     They  are  decom- 
posed by  strong  sulphuric  acid  at  a  boiling  heat,  and  by  strong  nitric  acid  at  common 
temperatures ;  but  they  are  hardly  affected  by  the  muriatic.     They  become  green  with 
chlorine,  but  resume  their  blue  color  when  treated  with  disoxydizing  reagents.     When 
Prussian  blue  is  digested  in  warm  water  along  with  potash,  soda,  or  lime,  peroxyde  of 
iron  IS  separated,  and  a  ferroprussiate  of  potash,  soda,  or  lime  remains  in  solution.     II 
the  Prussian  blue  has  been  previously  purified  by  boiling  in  dilute  muriatic  acid,  and 
washing  with  water,  it  will  afford  by  this  treatment  a  solution  of  ferrocyanodide  of  po- 
tassium, from  which  by  evaporation  this  salt  may  be  obtained  in  its  purest  crystalline 
state.     When  the  powdered  Prussian  blue  is  diffused  in  boiling  water,  and  digested  with 
red  oxyde  of  mercury,  it  parts  with  all  its  oxyde  of  iron,  and  forms  a  solution  of  bi-cy- 
anodide,  improperiy  called  prussiate  of  mercury ;  consisting  of  79-33  mercury,  and  20-67 
cyanogen;  or,  upon  the  hydrogen  equivalent  scale,  of  200  mercury,  and  52=(26X2) 
cyanogen.     When  this  salt  is  gently  ignited,  it  affords  gaseous  cyanogen.     Hydrocyanic 
or  prussic  acid,  which  consists  of  1   atom  of  cyanogen  =  26,  -f  1   of  hydrosen  =  1,  is 
prepared  by  distilling  the  mercurial  bi-cyanide  in  a  glass  retort  with  the  satutjiting  quan- 
tity  of  dilute  muriatic  acid.     Prussic  acid  may  also  be  obtained  by  precipitating  the  mer- 
cury by  sulphureted  hydrogen  gas  from  the  solution  of  its  cyanide;  as  also  by  distilling 
the  ferrocyanide  oi  potassium  along  with  dilute  sulphuric  acid.     Prussic  acid  is  a  very 
▼olatile  light  fluid,  eminently  poisonous,  and  is  spontaneously  decomposed  by  keeping,  es- 
pecially when  somewhat  concentrated. 

Haying  expounded  the  chemical  constitution  of  Prussian  blue  and  prussiate  of  potash. 
I  shall  now  treat  of  their  manufacture  upon  the  commercial  scale. 

l.Ofblood-ley,  the  phlogisticated  alkali  of  Scheele.  Among  the  animal  substances  nsed 
for  the  preparation  of  this  lixivium,  blood  deserves  the  preference,  where  it  can  be  had 
cheap  enough.  It  must  be  evaporated  to  perfect  dryness  reduced  to  powder  and  sifted 
Hoofs,  parings  of  horns,  hides,  old  woollen  rags,  and  other  animal  offals,  are,  however^ 
generally  had  recourse  to,  as  condensing  most  azotized  matter  in  the  smaUest  bulk.  Dried 
funguses  have  been  also  prescribed.  These  animal  matters  may  either  be  first  carbonized 
m  cast  iron  cylinders,  as  for  the  manufacture  of  sal  ammoniac  (which  see),  and  the  residual 
charcoal  may  be  then  taken  for  making  the  ferroprussiate ;  or  the  dry  animal  matters  may 
be  directly  employed.  The  latter  process  is  apt  to  be  exceedingly  offensive  to  the  work- 
men and  neighborhood,  from  the  nauseous  vapors  that  are  exhaled  in  it.  Eight  pounds 
of  horn  (hoofs),  or  ten  pounds  of  dry  blood,  afford  upon  an  average  one  pound  of  charcoal. 
This  must  be  mixed  well  with  good  peariash,  (freed  previously  from  most  of  the  sulphate 
of  potassa,  with  which  it  is  always  contaminated),  either  in  the  dry  way,  or  by  soakin* 
the  bruised  charcoal  with  a  strong  solution  of  the  alkali ;  the  proportion  being  one  pari 
of  carbonate  of  potassa  to  from  1^  to  2  parts  of  charcoal,  or  to  about  eight  parts  of  hani 
animal  matter.  Gautier  has  proposed  to  calcine  three  parts  of  dry  blood  with  one  of  ni 
tre ;  with  what  advantage  to  the  manufacturer,  I  cannot  discover. 

The  pot  for  calcining  the  mixture  of  animal  and  alkaline  matter  is  egg-shaped  as 
represented  at  a,  yig.  1188  and  is  considerably  narrowed  at  the  neck  «,  to  facilitate  th^ 
closing  of  the  mouth  with  a  lid  i.     Ii  Ls  made  of  cast  iron,  about  two  inches  thick  in  the 

belly  and  bottom;  this  strength  being  requi- 
site because  the  chemical  action  of  the  ma- 
terials wears  the  metal  fast  away.  It  shouki 
be  built  into  the  furnace  in  a  direction  sloping 
downwards,  (more  than  is  shown  in  the  figure), 
and  have  a  strong  knob  b,  projecting  from 
its  bottom  to  support  it  upon  the  back  wall, 
while  its  shoulder  is  embraced  at  the  arms  c,  c, 
by  the  brickwork  in  front.  The  interior  of 
the  furnace  is  so  formed  as  to  leave  but  a 
space  of  a  few  inches  round  the  pot,  in  order 
to  make  the  flame  play  closely  over  its  whole 
surface.  The  fire-door/,  and  the  draught- 
hole  Zf  of  the  ash-pit,  are  placed  in  the  pos- 
—  terior  part  of  the  furnace,  in  order  that  the 

workmen  may  not  be  incommoded  by  the  heat.    The  smoke  vent  o,  issues  through  the 


502 


PRUSSIAN  BLUE. 


a 


!•• . 


.^;! 


,^»    u     "*  "^  I'^'^civeu.     Ai  mis  time,  the  neat  should  be  increased  thp  mm.fj,  «r  «k« 
In^  '^^^^^aaiiy  Kept  up,  the  flame  becomes  less  and  less  each  time  that  the  not  w  on^nli 

with  iron-rust  cement,  and  re-inserted  with  thpcnnn^  a       \,^  ^umace,  patched  up 

solution  was  emploved  direotlv  fnr  tKo  «,.o«:,.;t„«-        r  ^"""^"y/nai  very  complex  impure 

regulated  works,  i^rcoTvertVbv  evln^^^^^^  of  Prussian  blue  ;  but  now,  in  all  well 

of  potash.     The  mother  watPrJ«LJ-^  f "?  ^°5^'""  '"*°  crystallized  ferroprussiate 

inferior  ferroprusSate  isTbtainid  ^=^'"  f^^''^'''^  .^"^  crystallized,  whereby  a  somewhat 

add  as  much  solu  on  of  er"iohrte  of^rL'^r/^^    '''i  '^'  ^'^7^^' ''  '^  ^^^^^^^e  to 

tate  of  cyanide  of  iron  wh'T  first  fak  I  idth      i  ^'  ""'"  re-d,ssolve  the  white  precipi- 

which  is  present  in  thJl  oL  fntn  f^  f  ^^/  *'°''^^.''  ^^^  ^>'*"^^«  ^^  potassium, 

siate  of  potash  may  be  rendered  ciemtT/'"^^'  k^  potassium.     The  commercial  prus-' 

stove,  fusing  them  whh  a  Ini  h-t  ^      ^^^'^     ^  "     -^  '^'  "^'^*^'  effloresce  in  a 

neutralizin/anyca7Cate^anfcvaniL'%*^.^^l%l''°'''*^'^^^^^^^       '^'  "^^'^  ^^  ^«ter, 

then  precipitating  the  fer  oprussia^te  o^  r^2?  i^?^  ^'  S"""'""*  ^^^^  «^^»'^  «^iJ 

alcohol,  and  finally  cryslEn'    he  nreS^-'     ^'* '''  *  '"^"'"'  ^"'"'^''^  "^ 

of  potassa  may  be  dewmposed  bv  aopt«?p  nf  k     f  ^^  ^wice  over  in  water.    The  sulphate 
removed  by  alcohol.     ^  ^  ^''^^^^  *^^  ^^-"y^^'  ^"^  ^^^  ''^s^lti"?  acetate  of  potassa 

^yle'^^tnZ:^::!^^^^^  -;P»;^te  of  iron  is  always  employed 

prussiate,  in  forming  Prussian  blue  thouah^thP  r'  ^     f^u '""  "^-'^^  '°^"^^°"  «^  ^^^^  ^^"'>' 
would  afford  a  much  richer  bhiep^Jment'V^^^  ""''T'  ^ '""T^t  «^  -oa 

carefuUy  freed  from  any  cupreoL^  i^P-gn^^' T^^ 


PRUSSIAN  BLUE. 


503 


dirty  brownish  cast.  The  green  sulphate  of  iron  is  the  most  advantageous  precipitant, 
on  account  of  its  affording  protoxyde,  to  convert  into  ferrocyanide  any  cyanide  of  po- 
Ussium  that  may  happen  to  be  present  in  the  uncryslallized  lixivium.  The  carbonate 
of  potash  in  that  lixivium  might  be  saturated  with  sulphuric  acid  before  adding  the 
solution  of  sulphate  of  iron;  but  it  is  more  commonly  done  by  adding  a  certain  portion 
of  alum;  in  which  case,  alumina  falls  along  with  the  Prussian  blue;  and  though  it 
renders  it  somewhat  paler,  yet  it  proportionally  increases  its  weight ;  whilst  the  acid  of 
the  alum  saturates  the  carbonate  of  potash,  and  prevents  its  throwing  down  iron-oxyde, 
to  degrade  by  its  brown-red  tint  the  tone  of  the  blue.  For  every  pound  of  pearlash 
used  in  the  calcination,  from  two  to  three  pounds  of  alum  are  employed  in  the  precipi- 
tation. When  a  rich  blue  is  wished  for,  the  free  alkali  in  the  Prussian  ley  may  be  partly 
saturated  with  sulphuric  acid,  before  adding  the  mingled  solutions  of  copperas  and 
alum.  One  part  of  the  sulphate  of  iron  is  generally  allowed  for  15  or  20  parts  of  dried 
blood,  and  2  or  3  of  horn-shavings  or  hoofs.  But  the  proportion  will  depend  very 
much  upon  the  manipulations,  which,  if  skilfully  conducted,  will  produce  more  of  the 
cyanides  of  iron,  and  require  more  copperas  to  neutralize  them.  The  mixed  solutions 
of  alum  and  copperas  should  be  progressively  added  to  the  ley  as  long  as  they  produce 
any  precipitate.  This  is  not  at  first  a  fine  blue,  but  a  greenish  gray,  in  consequence  of 
the  admixture  of  some  white  cyanide  of  iron ;  it  becomes  gradually  blue  by  the  absorption 
of  oxygen  from  the  air,  which  is  favored  by  agitation  of  the  liquor.  Whenever  the 
color  seems  to  be  as  beautiful  as  it  is  likely  to  become,  the  liquor  is  to  be  run  off  by  a 
spigot  or  cock  from  the  bottom  of  the  precipitation  vats,  into  flat  cisterns,  to  settle. 
The  clear  supernatant  fluid,  which  is  chiefly  a  solution  of  sulphate  of  potash,  is  then 
drawn  off  by  a  syphon  ;  more  water  is  run  on  with  agitation  to  wash  it,  which  after 
settling  is  again  drawn  off;  and  whenever  the  washings  become  tasteless,  the  sediment  is 
thrown  apon  filter  sieves,  and  exposed  to  dry,  first  in  the  air  of  a  stove,  but  finally  upon 
slabs  of  chalk  or  Paris  plaster.  But  for  several  purposes,  Prussian  blue  may  be  best 
employed  in  the  fresh  pasty  state,  as  it  then  spreads  more  evenly  over  paper  and  other 
surfaces. 

A  ffood  article  is  known  by  the  following  tests  :  it  feels  light  in  the  hand,  adheres  to 
the  tonffue,  has  a  dark  lively  blue  color,  and  gives  a  smooth  deep  trace;    it  should  not 
effervesce  with  acids,  as  when  adulterated  with  chalk ;    nor  become  pasty  with  boiling 
water,  as  when  adulterated  with  starch.     The  Paris  blue,  prepared  without  alum,  with 
a  peroxyde   salt  of  iron,  displays,  when  rubbed,  a  copper-red  lustre,  like  indigo.     Prus- 
sian blue,  detfraded  in  its  color  by  an  admixture  of  free  oxyde  of  iron,  may  be  im- 
proved by  digestion  in  dilute  sulphuric  or  muriatic  acid,  washing,  and  drying.     Its  rela- 
tive richness  in  the  real  ferroprussiate  of  iron  may  be  estimated  by  the  quantity  of  potash  oi 
soda  which  a  given  quantity  of  it  requires  to  destroy  its  blue  color. 

Sulphureted  hydrogen  passed  through  Prussian  blue  diffused  in  water,  whitens  it; 
while  prussic  acid  is  eliminated,  sulphur  is  thrown  down,  and  the  sesquicyanide  of  iron 
is  converted  into  the  single  cyanide.  Iron  and  tin  operate  in  the  same  way.  When 
Prussian  blue  is  made  with  two  atoms  of  ferrocyanide  of  potassium,  instead  of  one,  it  be- 
comes soluble  in  water. 

For  the  mode  of  applying  this  pigment  in  dyeing,  see  Cauco-printing. 

Sesqui/errocyanate  of  potash  is  prepared  by  passing  chlorine  gas  through  a  solution  d 
ferrocyanide  of  potassium,  till  it  becomes  red,  and  ceases  to  precipitate  the  peroxyde  salts 
trfiron.  The  liquor  yields,  by  evaporation,  prismatic  crystals,  of  a  ruby-red  transparency. 
They  are  soluble  in  38  parts  of  water,  and  consist  of  40*42  parts  of  sesquicyanide  of  iron, 
and  59'58  of  cyanide  of  potassium.  The  solution  of  this  salt  precipitates  the  foUowisg 
metals,  as  stated  in  the  tablt? ; — 

Bismuth 

Cadmium 

Cobalt 

Copper  (protox3'de) 
Do.    (peroxyde) 

Iron,  protoxyde  salts  of  blue. 

Manganese    -        -        brown. 

Mercury  (protox^'de)      red-brown. 

Neto  process  for  prussian  blue,  which  deserves  peculiar  notice,  as  the  first  in  which  thif 
interesting  compound  has  been  made  to  any  extent  independently  of  animal  matter. 
Mr.  Lewis  Thompson  received  a  well-merited  medal  from  the  Society  of  Arts,  in  1837, 
for  this  invention.  He  justly  observed  that  in  the  common  way  of  manufacturing 
prussiate  of  potash,  the  quantity  of  nitrogen  furnished  by  a  given  weight  of  animal 
matter  is  not  large,  and  seldom  exceeds  8  per  cent. ;  and  of  this  small  quantity,  at  leaal 
one  half  appears  to  be  dissipated  during  the  ignition.  It  occurred  to  him  that  the 
atmosphere  might  be  economically  made  to  supply  the  requisite  nitrogen,  if  caused  to 
Act  in  favourable  circumstances  upon  a  mixture  of  carbon  and  potash.    He  found  tb« 


pale  yellow. 

yellow. 

dark  brown-red. 

red-brown. 

yellow-green. 


Mercury  (peroxyde) 

Molybdenum 

Nickel 

Silver 

Tin  (protoxyde) 

Uranium     - 

Zinc 


yellow. 

red-brown. 

yellow-green. 

red-brown« 

white. 

red-brown. 

orange-yellow. 


504 


PRUSSIATE  OF  POTASH. 


1  i:  I 


P 


3 

,1' 


$ 


foUowing  prescription  to  answer.  Take  of  pearlash  and  coke  each  2  nartg  •  iron 
turnings,  1  part;  grind  them  together  into  a  coarse  powder  plL^  this  m  an  onen 
crucible,  and  expose  the  whole  for  half  an  hour  to  a  fSl  r.d  hW^tlTan  opei^  Z  Zth 
occasional  stirring  of  the  mixture.  During  this  process,  little  iet«  of  puX  flame  will 
be  observed  to  rise  from  the  surface  of  the  materials.  When  these  ceShecrucrble 
must  be  removed  and  allowed  to  cool.  The  mass  is  to  be  lixivfated  \lie  iSv^ 
which  IS  a  solution  of  ferrocyanide  of  potassium,  with  excess  of  potash  is  to  be TreltS 
m  the  usual  way,  and  the  black  matter  set  aside  for  a  fresh  operation  ^^th  a  fresh 
dose  of  peariash     Mr  Thompson  states  that  one  pound  of  peariasrcJ^taininr45 

Tabont  f  *^^"^''  ^''^f^  '^''  e^*^^«  «^  P^^^  ^^"««i^^  Wue,^or  ferr Van^d',";"\>of  . 
or  about  3  ounces  avoirdupois.  j""iuc  ui  iiou , 

PRU^IATE  OF  POTASH.    Leuch's  Polytechnic  Zeitnng,  June,  1837.    Manufac 
tare  of  Kalium  Eisen  Cyanure,  by  Hofflmayr  and  Prukner.-The  potash  musfbeire^ 
from  sulphate,  for  each  atom  of  sulphur  destroys  an  atom  of  the  Eisencyankalium     A 
very  s  rong  heat  is  advantageous.     The  addition  of  from  1  to  3  §  of  saltpetre  is  useful 
when  the  mass  is  too  long  of  fusing.    A  reverberatory  furnace  (flammofen)  is  recom-' 

^o?  r  '  .u"*  ^.,?u^"^  "''''^  ''^^  ^^^  ^"^  '""^^^  "Pon  ^^^  materials,  for  fear  of  oxy- 
genating them.  When  the  smoky  red  flame  ceases,  it  is  useful  to  throw  in  from  time 
to  t  me  small  portions  of  uncarbonized  animal  matter,  particularly  where  the  flame  first 
beats  upon  the  mass,  whereby  the  resulting  gases  prevent  oxidation  by  the  air.  The 
«!T!i  ?'fu"^"u'^''"^fM"^'  ^  ^"^  '""'^^  carbonized,  but  left  somewhat  brown-colored, 
m»v  i  ino^^  ^  readilj' pulverized.  Of  uncarbonized  animal  matters,  the  proportions 
may  be  100  parts  dried  blood,  to  from  28  to  30  of  potash  (carbonate),  and  from  2  to  4  of 
hammerschlag  (smithy  scales),  or  iron  filings;  2,  100  parts  of  horns  or  hoofs  ;  from  33 

Woo5  T,!f V  ^  '°  ^"*^? '  K^'  ^^^  ^"^''^" '  ^^  '^  ^«  P«*^«h  5  «»d  2  to  4  iTou.  From 
blood,  8  to  9  per  cent,  of  the  prussiate  are  obtained  ;  from  horns,  9  to  10  ;  and  from 

I  if'?  ''i"  ^-  T^^  P^*^'^  '^''''^^  ^^  °^'^^^  i^  ^««"^  particles,  like  peas,  with  th^ 
^n^iu  T/^u^  ""^"^V  "^^r^  f  ^y  ^^  ^'^  ^''"^  ^°  «  revolving  pot,  containing  can- 
?rn^  lo  t;    ^^!^\*"'°^«.^  coal  and  potash,  equal  parts  may  be  taken,  except  with  that 

LnThnrn  "''i  "^^'VTZ^'  ^  ^^^.  ^^^^  °**^^  P°^««^  P^'  ^^^^^  ^^  ^^^  average,  blood 
8°  bit  hv  ^oi?  t^""^?  aff-ord  never  less  than  20  per  cent,  of  prussiate,  nor  the  leather  than 
8;  but  by  good  treatment,  they  may  be  made  to  yield,  the  first  25,  and  the  last  from  10 

Reduce  charcoal  into  bits  of  the  size  of  a  walnut,  soak  them  with  a  solution  of  car- 
bonate  of  potash  in  urme ;  and  then  pour  over  them  a  solution  of  nitrate  or  acetate  of 
m>n;  dry  the  whole  by  a  moderate  heat,  and  introduce  them  into  the  cast-iron  tubes 
presently  to  be  described.     The  following  proportions  of  constituents  have  been  found 

?^ TZ^'  ''^  ^fli?"^,  ^T^d^  ^^"^ '  ."''^'^'  ^" '  ^*^^*"t«  «^  »^«n'  15  ;  <^harcoal  or  coke, 
Ur  t  Jhif  r^  ^^T^'  ^^''J^^  materials,  mixed  and  dried,  are  put  into  retorts  simi-' 

T^i  Jin  w  ''?^*  P-*  ^^^  ^"'"".^^  ^^^^^''  ^"^^^^'^  <^^«  ^lo^)>  "  placed  in  sepa- 
rate compartments  of  pipes  connected  with  the  above  retorts.    The  pipes  containing  the 

animal  matter  should  be  brought  to  a  red  heat  before  any  fire  is  placed  under''  the 

J.^^^lV^^^^i  ^»  ^»  ^»  Is  a  horizontal  section  of  a  furnace  constructed  to  receive  four 
elliptical  iron  pipes.  The  furnace  is  arched  in  the  part  a,  c,  b,  in  order  to  reverberate 
the  heat,  and  drive  it  back  on  the  pipes  w,  w',  w",  w'".  These  pipes  are  placed  on  the 
plane  E,  r,  of  the  ellipsoid ;  a  a,  represents  the  grating  or  bars  of  the  furnace  to  be 
heated  with  coal  or  coke;  i,  i,  is  the  pot  or  retort  shown  in^g«.  1190,  11  yi  1192 
This  pot  or  retort  is  placed  in  a  separate  compartment,  as  seen  in  /Iff.  1189  which  is  a 

rretrr  Cm^^^^^^^^^^^^  T"  ''  ^'^  ^-^  -  ^^  -  «  — ^-^  tube,  from 
In  section.  Jig.  1190.,  the  shape  of  the  tube  k  will  be  better  seen ;  also  its  cocks  «. 
ajad  likewise  Its  connection  with  the  pipes  w.  I,  is  a  safety  valve ;  «,  the  cover  of 
the  pot  or  retort ;  i,  is  the  ash-pit ;  and  6,  the  door  of  the  furnace ;  x,  is  an  open 
ST'^tler''        '''''''''  '*'"  *  ^'^  ^^^^  *'^''^®  ^"^  ^^^  furnace,  and  under  it  the  pipes  are 

The  arrows  indicate  the  direction  of  the  current  of  heat  This  current  traverses 
the  intervals  left  between  the  pipes,  and  ascends  behind  them,  passing  through  the 
aperture  J,  m  the  brick  work,  which  is  provided  with  a  valve  or  4mper,  for  cloliiiij  it, 
AS  reqmred.  The  heat  passes  through  this  aperture,  and  strikes  against  the  sides  of 
the  pot  when  the  valve  is  open.     Another  valve  /.  g,  must  also  be  open  to  expose  the 

mto^a  chimne     n  *''^'''''  ""^  ^^  ^^*     ^^^  '"'''^^  ^^^^^  ^^  *  lateral  passage 

It  must  be  remarked  that  there  is  a  direct  communication  between  the  chimney  and 
that  compartment  of  the  furnace  which  contains  the  pipes,  so  that  the  heat,  reflected 
from  the  part  v,  strikes  on  the  pot  or  retort  only  when  the  pipes  w,  w',  w".  w'".  are 
•omciently  heated.  *^         ,      ,      ,        ,  »ic 

in  Jig.  1191.  is  shown  an  inclined  plane  m  (also  represented  in;?^.  1190.)  and  the  juno- 


PRUSSIATE  OF  POTASH. 


505 


1189 


1191 


tion-tubes  which  connect  the  four  pipes  with  their  gas-burners  z,  z,  and  the  cocks  m, 
m'.  r,  r,  are  covers,  closing  the  pipes,  and  having  holes  formed  in  them  ;  these  holes 
are  shut  by  the  stoppers  e. 

Whether  the  pipes  are  placed  in  the  vertical  or  horizontal  position,  it  is  alwa^'s 
proper  to  be  able  to  change  the  direction  of  the  current  of  gas  ;  this  is  easily  done  by 
closing,  during  one  hour  (if  the  operation  is  to  last  two  hours,)  the  cocks  i,  m'  and 
opening  those  u',  m  ;  then  the  gas  passes  through  %i\  into  the  branch  k,  and  entering 
w  ,  passes  through  q,  into  w",  through  jt>,  into  w',  and  through  o,  and  w,  and  finally 
escapes  by  the  burner  z.  During  the  following  or  other  hour,  the  cocks  u'  in,  must 
be  closed  :  the  cocks  u,  m',  being  opened,  the  current  then  goes  from  u,  into  k  w  w' 
w",  w'",  and  escapes  by  the  burner  z',  where  it  may  be  ignited.  '     '      * 

The  changing  of  the  direction  of  the  current  dispenses,  to  a  certain  degree  with  the 
labour  required  for  stirring  with  a  spatula  the  matters  contained  in  the  pipes  •  never- 
theless, It  IS  necessary,  from  time  to  time,  to  pass  an  iron  rod  or  poker  amongst  the 
substances  contamed  in  the  pipes.  It  is  for  this  purpose  that  apertures  are  tormed. 
so  as  to  be  easily  opened  and  closed. 

The  patentee  remarks,  that  although  this  operation  is  only  described  with  reference 
to  potash,  lor  obtaining  prussiate  of  potash,  it  is  evident  that  the  same  process  is 
applicable  to  soda:  and  when  the  above-mentioned  ingredients  are  employed  soda 
being  substituted  for  potash,  the  result  will  be  prussiate  of  Boda.— Newton  s  Journal 
C.  S.  XXI.  96.  ' 

Manv/actiirc  of  Prussiate  of  Potash.  All  things  considered,  the  manufacture  of 
prussiate  of  potash  is,  perhaps,  less  understood,  and  therefore  less  perfect,  than  that  of 
any  other  chemical  substance  of  equal  importance.  The  conditions  requisite  to  ensure 
success  are  totally  unknown  amongst  scientific  men,  and  the  manufacturers  themselves 
seem  so  divided  m  their  opinions  respecting  the  best  modes  of  production,  that  nothing 
valuable  can  be  deduced  tiom  the  discordant  results  of  their  experience.  Thus,  whilst 
some  are  so  careful  to  avoid  the  presence  of  water  in  the  materials  they  employ  that 
these  are  highly  dried  before  being  cast  into  the  furnace  pot,  others  pay  no  regard  at  all 

Vol.  IL  2  T 


i«M 


^^^ 


•fc»> 


506 


PRUSSIATE  OF  POTASH. 


PRUSSIATE  OF  POTASH. 


607 


to  this  circumstance,  or  even  actually  wet  the  nitrogenised  substances,  with  a  view  to 
increase  their  power.  The  diflference  in  theory  between  these  methods  is  so  enormous, 
that  it  ought,  long  ago,  to  have  shown  itself  in  the  practical  results,  if  there  be  not  some 
error  in  the  assertion  that  prussiate  of  potash  is  entirely  destroyed  by  steam  at  a  red 
heat  That  such  is  the  case  when  pure  prussiate  is  thus  acted  on,  no  one  can  doubt  for 
a  moment ;  but  how  far  this  is  true  with  respect  to  the  mixture  of  carbonaceous  and 
alkaline  matters  contained  in  the  furnace  pot  of  a  prussiate  manufacturer,  remains  still 
to  be  investigated.  Whatever  be  the  plan  adopted,  a  prodigious  waste  invariably 
occurs  in  making  prussiate  of  potash ;  and  fully  two-thirds  of  all  the  nitrogen,  exist- 
ing in  the  azotised  ingredients  of  the  process,  are  driven  off  and  lost  More  frequently, 
indeed,  the  loss  amounts  to  three-fourths,  and  even  this  is  sometimes  exceeded.  The  state 
of  the  weather,  and  the  temperature  of  the  furnace,  also  largely  affect  the  production 
of  prussiate  of  potash, — for  damp,  foggy  weather,  and  a  low,  dull  heat,  are  extremely 
prejudicial.  The  most  favourable  indications  are,  a  heat  verging  on  whiteness,  and  th« 
production  of  a  clear,  bright  flame,  the  moment  the  materials  are  thrown  into  the  pot 

Woollen  rags  or  clippings,  and  good  American  potash  or  pearlash,  with  an  admixture 
of  scrap  iron,  have  given  a  larger  produce  than  any  other  substances  within  the  range  of 
our  experience,  though,  even  in  this  instance,  two-thirds  of  the  whole  nitrogen  passed 
away  as  ammonia.    In  general,  1  ton  of  dried  blood,  or  woollen  rags,  with  about  3  cwts, 
of  good  potash,  will  produce  from  2  cwts.  to  2^  cwts.  of  prussiate  of  potash,  and  a  pro- 
portionate amount  of  sulphate  of  potash.     The  presence  of  scrap  iron  in  a  proper  state 
of  subdivision  is,  however,  necessary  to  insure  the  above  result ;  for  when  no  more  is 
supplied  than  that  which  arises  accidentally  from  the  iron  pot  in  which  the  operation  is 
carried  on,  scarcely  half  these  proportions  will  be  obtained.     A  very  useful  mixture  may 
be  made  of  1  ton  of  proper  nitrogenised  matter  in  a  dry  condition,  with  from  3  to  4  cwts. 
of  pearlash  in  powder,  and  50  or  60  lbs.  of  scrap  iron  in  the  form  of  wire,  or  thin  sheets 
or  clippings.    This  is  to  be  projected  by  degrees  into  a  thick  iron  pot  previously  brought 
to  a  bright  cherry-red  heat ;  and,  after  each  addition,  the  whole  contents  of  the  pot  must 
be  well  stirred  with  a  heavy  iron  poker  or  bar,  until  the  residue  becomes  pasty ;  when 
more  of  the  mixture  must  be  thrown  in  and  similarly  treated,  until  the  pot  is  about  half 
full;  after  this,  the  heat  may  be  maintained  for  15  or  20  minutes;  and  then  the  charge 
must  be  ladled  out  to  make  room  for  another  operation.     The  form  and  nature  of  the 
iron  pot  are  by  no  means  matters  of  indiflFerence.     The  form  should  be  such  as  to  prevent 
the  access  of  air  as  much  as  possible,  without  causing  unnecessary  labour  to  the  workmen 
in  the  charging  and  emptying  of  the  pot ;  and,  in  consequence  of  the  high  temperature 
employed,  the  cast-iron  should  be  of  the  kind  called  "  cold-blast  iron ; "  for  this  will 
resist  a  much  greater  application  of  fire  than  "  hot-blast  iron."    The  old  shape  of  a 
prussiate  of  potash  pot  is  almost  exactly  that  of  an  egg,  with  its  upper  part  cut  off ;  and 
this,  in  an  economical  point  of  view,  is  scarcely  susceptible  of  improvement ;  but  the 
pasty  mass,  after  each  operation,  can  be  removed  from  this  pot  with  great  difficulty  only ; 
and  the  mixing  or  stirnng  is  still  more  open  to  objection.     Nevertheless,  many  manu- 
facturers continue  to  employ  this  form.     More  recently,  a  kind  of  oblong  shallow  trough 
has  come  into  use,  which  presents  every  facility  for  charging  and  discharging ;  but  the 
waste  of  nitrogen  is  said  to  be  considerable,  and  the  wear  and  tear  excessive ;  so  that  a 
middle  shape,  or  combination  of  the  two,  appears  indicated.     We  have,  however, 
witnessed  the  employment  of  common  gas-retorts  for  this  purpose,  and  with  the  most 
unqualified  success.    In  these,  the  action  of  the  air  is  entirely  prevented,  and  the  stirring 
process  goes  on  through  an  opening  in  the  cover,  which,  being  provided  with  a  plug  or 
stopper,  permits  the  occasional  condensation  of  much  of  the  waste  ammonia  to  take 
place  ;  or,  by  the  use  of  what  are  called  "  reciprocating  retorts,"  enables  the  manufac- 
turer to  pass  the  volatile  matters,  arising  from  a  recent  charge,  over  the  incandescent  ma- 
terials of  an  old  or  spent  charge,  so  as  to  convert  the  ammonia  they  contain  into  cyanogen. 

The  fii-st  steps  of  the  operation  being  finished,  the  pasty  mass  is  commonly  allowed 
to  cool  and  harden  ere  it  is  roughly  powdered  and  boiled  in  water.  Some  manufacturers^ 
however,  plunge  it  at  once,  whilst  still  red-hot,  into  cold  water,  and  fancy  that  some 
advantage  is  thus  gained.  In  a  theoretical  view,  the  proper  course  would  be  to  cover 
up  the  red-hot  mass,  so  as  to  obstruct  both  the  access  of  air  and  moisture,  and  thus 
prevent  the  decomposition  of  the  cyanide  of  potassium  during  the  process  of  cooling. 
As  the  prussiate  of  potash  is  extremely  soluble  in  boiling  water,  the  fused  mass  rapidly 
disintegrates  beneath  the  action  of  this  fluid ;  and,  in  a  short  time,  the  whole  is 
resolved  into  a  solution  of  the  prussiate,  carbonate,  and  sulphate  of  potash,  and  into 
an  insoluble  magma  of  carbon  and  scrap-iron.  By  filtration,  the  saline  fluid  is  sepa- 
rated from  the  insoluble  portion ;  and,  after  evaporation,  furnishes  crystals  of  prussiate 
of  potash,  mixed  with  sulphate  of  potash,  which,  by  re-solution  and  crystallization, 
are  rendered  sufl&ciently  pure  for  the  market 

Some  years  ago,  the  Society  of  Arts  presented  their  gold  medal  to  Mr.  L.  Thompson,  for 
his  discovery  of  the  manufacture  of  prussiate  of  potash  by  means  of  the  nitrogen  of  the 
air;  and  several  patents  have  since  been  taken  out  for  improvements  in  the  apparatus 


needed  to  render  this  discovery  available.  The  process  is  at  present  conducted  on  a  large 
scale  at  Newcastle-upon-Tyne,  and  seems  to  answer  the  object  contemplated  We  have 
not,however,had  an  opportunity  of  becoming  acquainted  with  its  commercial  advantages, 
though,  on  sanitary  grounds,  these  are  of  the  highest  importance.  The  fact  that 
atmospheric  nitrogen  can  be  brought  into  chemical  union  is,  nevertheless,  thoroughly 
established  by  this  discovery, — which  should  therefore  stimulate  inventors  to  further 
efforts  for  utilising  this  great  storehouse  of  azote.  If  nitrogen  can  be  made  to  unite 
with  carbon,  why  should  it  not  also  be  made  to  combine  with  hydrogen,  and  thus  pro- 
duce ammonia  ?  Twenty  years  ago  the  one  of  these  combinations  was  seemingly  as 
improbable  as  the  other. 

Much  attention  has  of  late  been  drawn  to  the  cyanogen  compounds  evolved  during 
the  distillation  of  coal  in  the  manufacture  of  gas ;  and  it  must  be  confessed  that  a  wide 
field  for  improvement  is  opened  in  this  direction.  The  quantity  of  cyanogen  triven  off 
during  the  decomposition  of  one  ton  of  common  Newcastle  coal  is  sufficient  to'producc 
about  7  pounds  of  Prussian  blue,  which,  at  the  existing  market-price,  would  greatly 
exceed  the  total  value  of  the  coal.  The  cyanogen  is  most  probably  evolved  in  the  fonn 
of  C3'anide  of  ammonium,  and  therefore  requires  protoxide  of  iron  for  the  purpose  of 
rendering  it  a  fixed  and  permanent  salt.  Hence,  if  either  the  protoxide  or  peroxide  of 
iron  be  placed,  so  that  the  gaseous  constituents  of  the  coal  are  made  to  pass  through  or 
over  these  oxides,  a  quantity  of  Prussian  blue,  and  prussiate  of  ammonia,  are  generated  . 
and  this  process  may  be  repeated  until  almost  the  whole  of  the  oxide  of  iron  has  been 
converted  into  ferrocyanic  acid  and  Prussian  blue.  We  have  said,  that  the  peroxide  of 
iron  will  answer  this  end  as  well  as  the  protoxide  ;  but,  in  reality,  it  is  still  the  protoxide 
which  acts,  for  the  impure  coal-gas  always  contains  sulphuretted  hydrogen  ;  and  this, 
as  is  well  known,  has  the  property  of  reducing  the  peroxide  of  iron  to  the  protoxide ; 
consequently,  both  are  equally  efficacious  in  the  production  of  ferrocyanic  acid.  When 
impure  coal-gas,  therefore,  has  been  passed,  for  some  time,  over  either  of  the  oxides  of 
iron,  a  substance  results,  from  which  prussiate  of  potash  may  be  obtained,  at  a  rate 
which  must,  one  day,  lead  to  the  total  suppression  of  the  present  mode  of  making  that 
article.  Let  us  suppose,  for  example,  that  a  few  pounds  of  oxide  of  iron  have  been 
mingled  with  sawdust,  and  subjected  to  the  action  of  the  impure  gas  arising  from  the 
distillation  of  50  tons  of  coal :  then  sufficient  cyanogen  must  have  combined  Avith  the 
iron  to  generate  35  pounds  of  Prussian  blue,  and  this  too  without  the  least  expense. 
Now  these  35  pounds  of  Prussian  blue,  when  treated  with  caustic  lime  and  sulphate  of 
potash,  would  afford  oxide  of  iron,  sulphate  of  lime,  and  prussiate  of  potash,  by  double 
decomposition, — the  latter  of  which  would  require  only  to  be  crystallized  from  the  fluid 
in  which  it  was  dissolved;  whilst  the  sulphate  of  lime  and  oxide  of  iron  might  be 
returned  again  to  the  position  formerly  occupied  by  the  oxide  of  iron  alone,  and  there 
made  to  combine  with  a  fresh  portion  of  cyanogen ;  and  so  on,  time  after  time.  We 
have  seen  some  cwts.  of  prussiate  of  potash  prepared  in  this  way  by  Mr.  Laming,  of  the 
Chemical  Works,  Millwall,  and  can  answer  for  the  purity  and  value  of  the  article. 
Mr.  Laming  has  also  manufactured,  in  a  similar  manner,  several  beautiful  samples  of 
Prussian  blue.  There  is,  however,  an  art  connected  with  the  production  of  Prussian 
blue,  which  requires  more  than  mere  purity  of  materials ;  for  if  an  inexperienced 
individual  were  to  attempt  to  make  a  good  marketable  Prussian  blue,  even  though 
possessed  of  the  purest  re-agents,  he  would  certainly  fail  to  bestow  upon  it  the  essentml 
conditions  of  colour  and  cohesion,  by  which  alone  it  attains  a  commercial  value.  The 
old  mode  of  obtaining  this  article,  in  a  proper  state,  was  by  precipitating  a  solution  of 
common  copperas,  or  protosulphate  of  iron,  by  a  mixed  solution  of  the  carbonate  and 
ferrocyanate  of  potash,  and  allowing  the  mixed  precipitate  of  oxide  and  prussiate  of  iron 
to  remain,  for  three  weeks,  in  contact  with  the  air ;  when  it  was,  in  technical  language, 
"  brightened"  by  the  addition  of  a  dilute  acid,  generally  muriatic.  The  theory  of  this 
process  appears  to  have  been  this — in  the  first  place,  protocyanide  and  protocarbonate 
of  iron  were  precipitated  together,  and  these,  by  exposure  to  the  air,  passed  into  the 
state  of  peroxide  of  iron  and  Prussian  blue  ;  the  peroxide  of  iron  meanwhile  acting 
mechanically,  and  preventing  the  particles  of  Prussian  blue  from  cohering  together  and 
becoming  one  hard  mass,  as  invariably  happens  when  no  such  impediment  to  cohesion  is 
present  Having  attained  this  end,  the  dilute  muriatic  acid  was  employed  to  dissolve 
away  the  superfluous  oxide  of  iron,  and  thus  bring  out  the  brilliancy  of  the  blue  colour, 
whilst  it  increased  the  peculiar  spongy  and  friable  nature  of  the  product,  and  this,  after 
copious  ablutions  of  hot  water,  was  next  dried  on  a  stone  and  sent  to  market  The 
practice  of  the  present  day  is,  however,  much  simpler  and  speedier  than  this ;  for,  instead 
of  3  weeks,  scarcely  3  days  are  now  necessary  for  the  production  of  Prussian  blue. 
The  plan  generally  followed  is,  to  dissolve,  in  two  separate  portions  of  boiling  water, 
exactly  as  much  protosulphate  of  iron  and  prussiate  of  potash  as  will  mutually  decom 
pose  each  other ;  and,  for  this  purpose,  nothing  but  actual  experiment  must  be  depended 
on,  as  the  atomic  numbers  of  these  substances  do  not  give  a  good  result     Assuming, 

8T2 


508 


PRUSSIC  ACID. 


^rtfon  nf  H  T  ^  ^  ir?*'^T  ""^  ^^  •  T  ^""'^  ^^  ^^«^  f«"°^  equal  to  a  giyen  ?«>- 
portion  of  tlie  other  and  that,  when  mixed  and  thrown  on  a  filter,  neither  iron  nor 
.  Ferrocyanic  acid  can  be  detected  in  the  filtered  fluid,  then  the  mixture  Ts  made  in  the^ 
proportions,  andaquanitv  of  recently  precipitated  peroxide  of  iron  havingbeen  added 
the  whole  IS  rapidly,  boilea  for  several  minutes ;  after  which  it  is  allowed  U,cooL  and  U 
then  brightened'''  by  a  dilute  acid,  copiously  washed  with  warm  waterdried  on  » 
stove,  and  rendered  fit  for  the  market.  Prior  to  drying,  the  colour  is  ^erv  often  brought 
down  by  the  addition  of  inert  colourless  substances,  such  as  starch! rnX^^^ 
^^r^u  ''1^7'''''  ^^^?*'  *«««rding  to  the  object  of  the  manufactured         ^  ^  ^ 

^  Ihe  fabrication  of  what  is  termed  the  red  prussiate  of  potash  has  now  assumed  an 
important  position  m  the  arts,  and  is  supposecl  by  some  to  constitute  a  kbd  of  s^cretlS 
the  trad^  There  is,  however,  in  truth,  nothing  secret  about  it  The  first  method  o1 
forming  this  salt  was  by  transmitting  chlorine  through  a  solution  of  ^he  common 
prussiace  of  potash,  until  ft  ceased  to  precipitate  the  permits  of  iron ;  ^nd,  as  this  rpTied 

diS^nu'^^r^  "^'^!  T  '^^  P*""*  ^^  '^'  "P^^^^«^'  '^'  r^«<^^««  «««»« to  be  regarded  aXth 
difficult  and  secret:  for  an  excess  of  chlorine  not  only  constituted  a  waste  but.  mor^ 

ove^  actually  destroyed  the  red  prussiate  when  formed,  and  dius  led  to  a  total  faTC 
Now  however,  this  article  is  manufactured  in  the  dry  way,  and  the  ill  effects  of  an  exce^ 
ofchlorine  are  easily  obviated.  To  prepareita  quantity  of  ordinary  yellow  pru^iateol? 
po  ash  must  be  reduced  to  a  very  fine  powder,  anil  subjected  to  the  a^^L  oTcwS  Lf 

Thurn  ^^rf^V  ^S^t^^r'T?"'^  ^"^^  """T^^'  ^'  that  Aich  can  be  produced  in  a  TOtf^ 
churn.  In  this  way  the  clilorme  is  rapidly  absorbed,  and  chloride  of  potassium  and  red 
prussiate  of  potash  generated.  When  it  is  found  that  the  chlorine  paLs  freely  throiSh 
^e  mixture,  without  being  absorbed,  the  process  must  be  stopped  and  the  powder 

he^faZ\  ^^Hr^'^'  ^'^  ^r  ^  dissolved  in  the  smaUest  possible  quantity  of  wlte^ 
heated  to  about  18D°  Fahr.,  will  produce,  on  cooling,  long  ne^e-shaped  crystals  of  the 
red  prussiate  ot  potash,  which  may  be  rendered  purS  and  larger  by  rec^ySlli^^^^^^^^ 
tiie  usual  way;  the  chloride  of  potassium,  meanwhile,  reLiniig  Ssolverfn  the 
mother-hquor.  It  is  far  from  improbable  that  this  salt  might  be  made  by  means  of  the 
permanganate  of  potash,  or  chameleon  mineral,  as  the  manganesic  acid^parts  with  iU 

bZfi^J/'^h'''''"'''"'^'^^^^"  ^^  ^"'"^^^-     I^^^i«  Buplosition  BhouFd  turnout  to 
be  correct,  then  a  saving  would  occur  in  the  process,  even  independently  of  the  cost  of 

KinnL.f?''  7^^tu^  "^T"^  ^  '^'■'^^^  investigation  by  those  interested  inthisKancI 

cLiTo  prin^r'  '"^  ^"""""'^'^  ^  '*P^^^^  '^'^'^^e  in  use  amongst  dyers  and 

PRUSSIC  ACID;  I^iebia's  new  test  for.    When  some  sulphuret  of  ammonium  and 

caustic  ammonia  are  added  to  a  concentrated  aqueous  solution  of  prussie  acid,  and  the 

Z^TjTi  ""'-'^  '^'  f  1^''^^"  ^.^P^r  ^^^^^  of  sulphur,  the  prussie  acid  is  converted 
in  a  few  minutes  into  sulphocyanide  of  ammonium.     This  metamorphosis  dependron 
the  circumstance,  that  the  higher  sulphurets  of  ammonium  are  instantly  deprived  by  the 
cyanide  of  ammonium  of  the  excess  of  sulphur  they  contain  above  the  monosulphuret 
for  instance,  if  a  mixture  of  prussie  acid  and  ammonia  be  added  to  the  pentasuiphuret 

wT^r^''"'!  'k'  '^.^"?^''  ^^  ""^''^  ''  ^^  *  ^^^P  >'«"«^  <^olo"r,  and  the  whole  Ctly 
heated,  the  sulphuret  of  ammonium  is  soon  discolorized,  and  when  the  clear  colourle^ 
hquid  IS  evaporated  and  the  admixture  of  sulphuret  of  ammonimn  expelled,  a  white  sahni 
mass  IS  obtained,  which  dissolves  entirely  in  alcohol.  The  solution  yields  orcoohng  oJ 
evaporation  colourless  crystals  of  pure  sulphocyanide  of  ammonium.  Only  a  sm^ 
quantity  of  sulphuret  of  ammonium  is  requisite  to  convert,  in  presence  of  an  excesT^ 
su  phur,  unlimited  quantities  of  cyanide  of  ammonium  into  sulphocyanide  ;  because  the 
sulphuret  of  ammonium  when  reduced  to  the  state  of  monosuJphuJet,  con'stantly  re  ac! 
quires  its  power  of  dissolving  sulphur,  and  transferring  it  to  the  cy an  de  of  amuYonii^ 

ll^:Z!^i:ZT:^'''  "^  ^^^  'T^  '^  ^^  advanfageous.  2  Lees  of  solutionTf' 
^usUc  ammonia,  ot  0-9o  specific  gravity,  are  saturated  with  sulphuretted  hydrogen  eas  • 
the  hydrosulphuret  of  ammonia  thus  obtained  is  mixed  with  6  ounces  of  the  erne 
solution  of  ammonia,  and  to  this  mixture  2  ounces  of  the  flowers  of  sulphur  are  addT 
and  then  the  product  resulting  from  the  distillation  of  6  ounces  of  prusCte  of  ^taslu 
3  ounces  of  the  hydrate  of  sulphuric  acid,  and  18  ounces  of  water.  Ih  s  miiTure  is 
digested  m  the  water  bath,  until  the  sulphur  is  seen  to  be  no  longer  altered  and  the 
hqmd  has  assumed  a  yellow  colour ;  it  is  then  heated  to  boiling,  and  kept  at  this  temi^! 
niture  until  the  sulphuret  of  ammonium  has  been  expelled  and  the  liquor  ImsaX 
become  colourless.  The  deposit,  or  excess  of  sulphur,  is  now  removc^d  by  tiltrat^ion" 
and  the  hquid  evaporated  to  crystallization.  In  this  way  from  3]  to  3i  ounces  are  got  of 
a  dazzlmg  white  dry  sulphocyanide  of  ammonium,  whi/h  may  be  employed  as  a  reagent 
and  for  he  same  purposes  as  the  sulphocyanide  of  potassium :  of  the  2  ounces  of  sul- 
phur  added,  half  an  ounce  is  left  undissolved. 

The  habitude  of  the  higher  sulphurets  of  ammonium  towards  prussie  acid,  furnishes 
ftn  admirable  test  for  this  acid.    A  couple  of  drops  of  a  pru.sic  acid  wliich  has  ht&i 


PUDDLING  OF  IRON. 


509 


dilated  with  so  much  water  that  it  no  longer  gives  any  certain  reaction  with  salts  of 
iron  by  the  formation  of  prussian  blue,  when  mixed  with  a  drop  of  sulphuret  of 
ammonium,  and  heated  on  a  watch  glass  until  the  mixture  has  become  colourless,  yields 
a  liquid  containing  sulphocyanide  of  ammonium,  which  produces  with  persalts  of  iron 
a  very  deep  blood  red  colour ;  and  with  persalts  of  copper,  in  presence  of  sulphurous 
acid,  white  sulphocyanide  of  copper. 

PUDDLING  OF  IRON".  This  is  the  usual  process  employed  in  Great  Britain 
for  converting  cast  iron  into  bar  or  malleable  iron — a  crude  into  a  more  or  less  pure 
metal.  The  following  plan  of  a  puddling  furnace  has  been  deemed  economical,  espe- 
cially with  resi  ect  to  fuel,  as  two  furnaces  are  joined  side  by  side  together,  and  the 
workmen  operate  at  doors  on  the  opposite  sides.    Fig.  1193  represents  this  twin  furnace 


119S 


in  a  side  elevation;  yig-.  1194in  section,  according  to  the  line  E  F, in  ^g.  1195  which 
exhibits  a  plan  of  the  furnace.  The  various  parts  are  so  clearly  shown  in  form  and 
construction  as  to  require  no  explanation.  The  total  length  outside  is  I4{  feet ;  width, 
12f  feet :  from  which  the  dimensions  of  the  other  parts  may  be  measured. 

Iron  is  puddled  either  from  cast  pigs,  or  from  the  plates  of  the  refinery  (finery)  ftur- 
iMice.  In  several  iron-works  a  mixture  of  these  two  crude  metals  is  employed.  In  the 
refining  process,  the  waste  at  the  excellent  establishment  of  Mr.  Jessop,  at  Codner  Park, 
is  from  2^  to  2f  cwt.  per  ton ;  on  which  process  the  wages  are  Is.  per  ton ;  and  the 
coke  I  ton,  worth  6«» ;  so  that  the  total  cost  of  refining  per  ton  is  15*.,  when  pig-iron 
is  worth  3/.  10*. 

The  puddling  is  accompanied  with  a  loss  of  weight  of  1|  cwt.  per  ton ;  it  costs  In 
wages,  for  puddling  refinery  plates,  6s.  6d.,  and  for  pigs,  8». ;  in  which  18  cwt.  of  coal 
are  consumed ;  value,  5s.  per  ton. 

Shingling  (condensing  the  bloom  by  the  heavy  hammer)  costs,  in  wages,  la.  9d, 
per  ton ;  and  rough-rolling,  Is.  2d.  Cutting  and  weighing  these  bars  cost  9d.  for 
wages,  including  their  delivery  to  the  mill  furnace,  where  they  are  reheated  and  welded 
together.  The  mill  furnace  heating  costs  1«.  6d.  in  wages,  and  consumes  in  fuel  12  cwt 
of  coals,  at  5«.  per  ton.  The  rolling  and  straightening  cost  6«.  6<i ;  cropping  the  ends, 
weighing,  and  stocking  in  the  warehouse,  1«.  for  wages.  Wear  and  tear  of  power,  6*. 
Labourers  for  clearing  out  the  ashes,  <fec.  1«.  6cL  per  ton. 

In  Wales  4  tons  of  pig-iron  afford  upon  an  average  only  3  tons  of  bars.  From  the 
above  data  a  calculation  may  easily  be  made  of  the  total  expense  of  converting  crude 
into  cast-iron  at  the  respective  iron  works. 

A  great  economy  in  the  conversion  of  the  cast  into  wrought  metal  seems  about  to  be 
effected  in  our  iron  works,  by  the  application  of  a  current  of  voltaic  electricity  to  the 
crude  iron  in  a  state  of  fusion,  whether  on  the  hearth  of  the  blast  furnace,  or  on  the  fused 


510 


PUDDLING  OF  IRON. 


PURPLE  OF  CASSIUS. 


511 


I  < 


1194 


i^^^mmmmmm^-m/m-mm  mmt 


pigs  in  the  sand,  or  on  the  metal  immediately  on  its  being  run  from  the  finery  for- 
nace ;  the  voltaic  force  of  from  50  to  100  pairs  of  a  powerful  Smee's  battery  ieinc 
previously  arranged  to  act  upon  the  whole  train  of  the  metal.  This  process,  for  which 
Mr.  Arthur  Wall  has  recently  obtained  a  patent,  is  founded  upon  the  well-established 


E— i-  — 


sulphur,  phosphorus,  arsenic,  o^Tn^r^^^^^^^^ 

tioii  to  iron,  which  is  electro-positive      Wh^n  f>,n  \^r.^     •    *"*'^^™  "^gative  in  rela- 

b,a.t,f„™.ees.  is  subjected  durC^^Lurg'':^^^^^^^^ 

voltaic  electricity,  the  cliemical  affinities  bv  whioh  it*  vor,'««c  i.l/       poweriui  stream  of 

arc  firmly  associited  are  immediately  sXU^^^  components 

sulphur,  phosphorus,  Ac,  which  destroy  or  impkiT  its  tena^^^^^^^^^  T'  '^'^ 

readily  separable  in  the  act  of  puddling.     On  th 's  nrincinll  ^I  ^"i"'^"^^^'!^*:^' t>ecome 

ordinary  Effect  of  Mr.  Wall's  p^atent  efectiST^te^^s^red  i^t^^ 


the  excellent  iron-works  of  Mr.  Jessop,  at  Codner  Park,  Derbyshire,  where  the  elec- 
trised forge  pigs  discharge  those  noxious  elements  so  copiously  in  the  puddling  fur- 
nace, as  to  become  after  a  single  re-heating,  without  piling  or  fagoting,  brilliant  bars 
of  the  finest  fibrous  metal.  The  bars  so  made  have  been  subjected,  under  my  inspec- 
tion, to  the  severest  proofs  by  skilful  London  blacksmiths,  and  they  have  been  found  to 
bear  piercing,  hammering,  bending,  and  twisting,  as  well  as  the  best  iron  in  the  mar- 
ket I  have  also  analysed  the  said  iron  with  the  utmost  minuteness  of  chemical 
research,  and  have  ascertained  it  to  be  nearly  pure  metal,  containing  neither  sulphur 
nor  phosphorus,  and  merely  an  inappreciable  trace  of  arsenic.  I  can  therefore  con- 
scientiously recommend  Mr.  Wall's  patent  process  to  ironmasters  as  one  of  the  greatest; 
easiest,  and  most  economical  improvements,  which  that  important  art  has  lately  received. 
The  pecuniary  advantage  of  this  process,  in  respect  of  saving  labour  and  waste  of 
material,  has  been  estimated  at  one  pound  sterlmg  per  ton ;  but  it  is  not  yet  practically 
worked  out.  J      r  J 

The  effect  of  electrising  iron  is  displayed  in  a  singular  manner  by  the  conversion  into 
steel  of  a  soft  rod,  exposed  in  contact  with  coke,  for  a  few  hours,  to  a  moderate  red 
heat ;  a  result  which  1  have  witnessed  and  can  fully  attest 

PUMICE-STONE  {Pierre-ponce^  Fr. ;  Bimstein,  Germ.),  is  a  spongy,  vitreous-loolcing 
mineral,  consisting  of  fibres  of  a  silky  lustre,  interlaced  with  each  other  in  all  directions. 
It  floats  upon  water,  is  harsh  to  the  touch,  having  in  mass  a  mean  sp.  grav.  of  0*9 14 ; 
though  brittle,  it  is  hard  enough  to  scratch  glass  and  most  metals.  Its  color  is  usually 
grayish  white;  but  it  is  sometimes  bluish,  greenish,  reddish,  or  brownish.  It  fuses 
without  addition  at  the  blowpipe  into  a  white  enamel.  According  to  Klaproth,  it  is 
composed  of,  silica,  77-5;  alumina,  17-5;  oxyde  of  iron,  2  ;  potassa  and  soda,  3  ;  in  100 
parts.  The  acids  have  hardly  any  action  upon  pumice-stone.  It  is  used  for  polishing 
ivory,  wood,  marble,  metals,  glass,  &c.;  as  also  skins  and  parchment.  Pumice-stone 
is  usually  reckoned  to  be  a  volcanic  product,  resulting,  probably,  from  the  action  of 
fire  upon  obsidians.  The  chief  localities  of  this  minerafare  the  islands  of  Lipari,  Ponza, 
Ischia,  and  Vulcano.  It  is  also  found  in  the  neighborhood  of  Andernach,  upon  the  banks 
of  the  Rhine,  in  TenerifTe,  Iceland,  Auvergne,  &c.  It  is  sometimes  so  spongy  as  to  be 
of  specific  gravity  0*37. 

PUOZZOLANA  is  a  volcanic  gravelly  product,  used  in  making  hydraulic  mortar. 
See  Cements  and  Mortabs. 

PURPLT^.  OF  CASSIUS,  Gold  purple  {Pourpre  de  Cassius,  Fr. ;  Gold-jmrpnr,  Germ.), 
is  a  vitrifiable  pigment,  which  stains  glass  and  porcelain  of  a  beautiful  red  or  purple  hue. 
Its  preparation  has  been  deemed  a  process  of  such  nicety,  as  to  be  liable  to  fail  in  the 
most  experienced  hands.  The  following  observations  will,  I  hope,  place  the  subject  upon 
a  surer  footing. 

The  proper  pigment  can  be  obtained  only  by  adding  to  a  neutral  muriate  of  gold  a 
naixture  of  the  protochloride  and  pcrchloride  of  tin.  Everything  depends  upoii  this 
intermediate  state  of  the  tin ;  for  the  protochloride  does  not  afford,  even  with  a  con- 
centrated solution  of  gold,  either  a  chestnut-brown,  a  blue,  a  green,  a  metallic  preci- 
pitate, or  one  of  a  purple  tone ;  the  perchloride  occasions  no  precipitate  whatever, 
whether  the  solution  of  gold  be  strong  or  dilute;  but  a  properly  neutral  mixture,  pf 
1  part  of  cr)'stallized  protochloride  of  tin,  with  2  parts  of  crystallized  perchloride,  pro- 
duces^ with  I  part  of  crystallized  chloride  of  gold  (all  being  in  solution),  a  beautiful 
purple-colored  precipitate.  An  excess  of  the  protosalt  of  tin  gives  a  vellow,  blue,  or 
green  cast ;  an  excess  of  the  persalt  gives  a  red  and  violet  cast ;  an  excess  in  the  gold 
ealt  occasions,  with  heat  (but  not  otherwise),  a  change  from  the  violet  and  chestnut- 
bro^yn  precipitate  into  red.  According  to  Fuchs,  a  solution  of  the  sesquioxyde  of  tin  in 
muriatic  acid,  or  of  the  sesquichloride  in  water,  serves  the  same  purpose,  when  dropped 
into  a  very  dilute  solution  of  gold. 

Buisson  prepares  gold-purple  in  the  following  way.  He  dissolves,  first,  1  gramme 
of  the  best  tin  in  a  sufl[icient  quantity  of  muriatic  acid,  taking  care  that  the  sola 
tion  is  neutral ;  next,  2  grammes  of  tin  in  aqua  regia,  composed  of  3  parts  of  nitric 
acid,  and  1  part  of  muriatic,  so  that  the  solution  can  contain  no  protoxyde ;  lastly  7 
grammes  of  fine  gold  in  a  mixture  of  1  part  of  nitric  acid,  and  6  of  muriatic,  observine 
to  make  the  solution  neutral.  This  solution  of  a^old  bein?  diluted  with  3|  litres  of  water 
(about  three  quarts),  the  solution  of  the  perchloride  of  tin  is  to  be  added  at  once  and 
afterwards  that  of  the  protochloride,  drop  by  drop,  till  the  precipitate  thereby  formed 
acquires  the  wished-for  tone  j  afler  which  it  should  be  edulcorated  by  washing,  as  quickly 

AS  pOSSlDlCa 

Frick  gives  the  following  prescription  -.—Let  tin  be  set  to  dissolve  in  very  dilute 
aqua  regia  without  heat,  till  the  fluid  becomes  faintly  opalescent,  when  the  metal  must  be 
taken  out,  and  weighed.  The  liquor  is  to  be  diluted  laro:ely  with  water,  and  a  definite 
weight  of  a  dilrf^  solution  of  gold,  and  dilute  sulphuric  acid,  is  to  be  simultaneously 
stirred  into  the  nitfo-munate  of  tin.     The  quantity  of  solution  of  gold  to  be  poured  into 


^^^  PUTREFACTION. 

of  36  "Jo  r '""''  ^'  '"*^^'  '^^'  '^^  «^^**  ^  *^«  «"«  i«  to  the  tin  in  the  other  in  the  ratic 

Mu^rS^r/d^  ta^eTtre^^uf ou'f  Jfl"  'l ''  K  ^'  ^"'  "P^^"^  '''^  ^'  ^  dirty-brown  powder. 

t^the  seini  heTl^''- /"  '''  "^'''!"^  ^^^'^  ^^""^  ^^^^  ^^«  ^^^^^  o^  Un  accord  ng 
of  tin  U.J  ^-^  ^^*'^f.^s  a  purple  oxyde  along  with  the  sesquioxyde  c/  peroxvde 
aLoSingto!!"'"''"'^  "  differenay  reported  by  different  chemist.    The  eons'tSts 

,        Oberkampf,  in  the  purple  precipitate,  are    -        .        .    39^82         "^'Kg* 
Berzelius  '''''^^^        ^^""^        ....    20-58  79-42 

Buissr    - 3<^-725  69-275 

GayLussa  I        I        I        .       I        I  '    ^^^  till 

^ 17-87  82-13 

If  to  a  mixture  of  protochloride  of  tin,  and  perehloride  of  iron,  a  properlv  diluted  snln 
Uon  of  gold  be  added,  a  very  beautiful  purple  precipitate  of  Cass  us  w&e^a^^^^^^^ 

^P^rln  r"  ^'^  ^t  ^^^-  ^5  *^^  ""1"^^  '''  '^^  ''^^^  «^  a  protochloride.  The^rple  thus 
prepared  keeps  in  the  air  for  a  long  time  without  alteration.  Mercury  doL  not  au! 
from  It  the  smallest  trace  of  gold.-^FuchsWmmal  fur  Chemiet  ^y'''''^  "'^^^  "^'  ^*^* 

nitric  add  ^^^t  tf/?fi '  ^^  ^'/^  ''^^^'"l'^  \y  ^T.*^**^  ""^  °'  ^ithic  acid  with  dilute 
nitnc  acid.    It  has  a  fine  purple  color;  but  has  hitherto  been  applied  to  no  use  in  the 

«J»y7i^?^^^^^^^'  """^  *'*  -P*-^^'*"'^-    The  decomposition  of  animal  bodies  or  of 
tTev  i^e'exn^ed  rih;"'"  in  their  composition,  which  ^kes  place  sponleously  ^hen 
facti^     V^nt  ?J       "'  ""^^  ^^^-  ^'^fl^e^ce,  «f  "moisture  and  warmth,  is  called  putre- 
taction      During  this  process,  there  is  a  complete  transposition  of  the  proximate  nrin 
ciples,  the  elementary  substances  combining  in  new  and  principaHy  gase^s  iomt^unds' 
ofli!\y^''''^^  ^"^"^  '^^  atmosphere,  and  converted  into  carbom^add     oneCuon 
L    c^lt''^?J''"T  T''  ^it\*^«  o^y?en;  another  portion  forms,  wiUi  Ihe^^ote" 
the    carbon,   the    phosphorus,   and    the    sulphur   respectively,    ammonia    carburet^ 
phosphureted,   and  sulphureted  hydrogen  gases,   which   occaSonTe^au4o«s  smell 
evolved  by  putrefying  bodies.     There  remains  a  friable  earthy-looking  res  duum  Ton- 
sistmg  of  rotten  mould  and  charcoal.    Vegetables  which  contain  no  azote   h^i  the 
i^rS'nt'^  plants,  suffer  their  corresponding  decomposition  mucrmoJe  s'owly!  and 
with  diflerent  modifications,  but  they  are  finally  converted  into  vegetable  mould      In 
thLs  process,  the  juices  with  which  the  plants  are  filled  first  enter  into  the  acetous  fer 
^^ellnrnr^rh 'fi^  ""''""  of  heat  and  moisture;  the  acid  thereby  generated  destroys  Se 
^Pcc    r  t/  ^  /  fi^^o"s  "matter,  and  thus  reduces  the  solids  to  a  pulpy  state.    In  the  pro! 

^cave  ^'JlT^^'Tr'  "  '"j*^'""'"  ''.  ^^''^^  P^«^"^^^  which  resembles  oxyd  zZ^ 
teacUve,  IS  soluble  m  alkalis,  and  is  sometimes  called  mould.  This  decomposition  of  the 
plants  which  contain  no  azote,  goes  on  without  any  offensive  smell,  as  no^fof  the  a  W 

nlhe'd^unTn?' nf  'Z^'^T'"'''^'-  -  ^^^"  ^^^^^'^^^^  ^^''^^  -«  -^^  wi  h  antat 
as  in  the  dung  of  cattle,  this  decomposition  proceeds  more  rapidly,  because  the  animalized 

Ss  aJe'noiTtL'iT'"'  *  k- '^  ^'^^^"^^J*  ^^=^^^^^^  "^''^'^  '''''^'>  «^ts,  and  voktilkS 
ous,  are  not  of  themselves  subject  to  putrefaction. 

^hlilf  f^^""^  ^^  ^^^  ^''^''^"^  .^'""^^^  ^^  ^°  ^^^^^1  ^^«  principles  and  processes,  according  to 
rri^pn'tS'  ^^"°,f  P^'-P^ses  in  the  arts,  the  destruction  of  bodies  by  putrefiction  may  b2 
Rented,  and  their  preservation  in  a  sound  state  secured  for  a  longer  or  a  STorteJ 


PUTREFACTION. 


511 


/>- 


I.   COKDinONB  OF  THE  PIlfiVENTION  OF  PTTTREFACTrOH. 

The  circumstances  by  which  putrefaction  is  counteracted,  are,  1.  the  chemical  change 
of  the  azolized  juices;  2.  the  abstraction  of  the  water;  3.  the  lowering  of  the  tempera* 
ture;  and  4.  the  exclusion  of  oxygen. 

1.  The  chemical  change  of  the  azotized  juices. — The  substance  which  in  dead  aninoal 
matter  is  first  attacked  with  putridity,  and  which  ser\'es  to  communicate  it  to  the  solid 
fibrous  parts,  is  albumen,  as  it  exists  combined  with  more  or  less  water  in  all  the  animal 
fluids  and  soft  parts.  In  those  vegetables  also  which  putrefy,  it  is  the  albumen  which 
first  suffers  decomposition;  and  hence  those  plants  which  contain  most  of  that  proximate 
principle,  are  most  apt  to  become  putrid,  and  most  resemble,  in  this  respect,  animal  sub- 
stances; of  which  fact,  mushrooms,  cabbages,  coleworts,  &c.,  aflbid  illusti aliens.  The 
albumen,  when  dissolved  in  water,  very  readily  putrefies  in  a  moderately  warm  air ;  but 
when  coagulated,  it  seems  as  little  liable  to  putridity  as  fibrin  itself.  By  this  change,  it 
throws  oft"  the  superfluous  water,  becomes  solid,  and  may  then  be  easily  dried.  Hence, 
those  means  which  by  coagulation  make  the  albumen  insjoluble,  or  form  with  it  a  new 
compound,  which  does  not  dissolve  in  water,  but  which  resists  putrefaction,  are  powerful 
antiseptics.  Whenever  the  albumen  is  coagulated,  the  uncombined  water  may  be  easily 
evaporated  away,  and  the  residuary  solid  matter  may  be  readily  dried  in  the  air,  so  as  to 
be  rendered  unsusceptible  of  decomposition. 

In  this  way  acids  operate,  which  combine  with  the  albumen,  and  fix  it  in  a  coagulated 
state,  without  separating  it  from  its  solution ;  such  is  the  effect  of  vinegar,  citric  acid, 
•arlaric  aci-.  &c 

Tannin  combines  with  the  albuminous  and  gelatinous  parts  of  animals,  and  forms  insol- 
uble  comiwunds,  which  resist  putrefaction  ;  on  which  fact  the  art  of  tanning  is  founded. 

Alcohol,  oil  of  turpentine,  and  some  other  volatile  oils,  likewise  coagulate  albumen, 
and  thereby  protect  it  from  putrescence.  The  most  remarkable  operation  of  this  kind  is 
exhibjled  by  wood  vinegar,  in  consequence  of  the  creosote  contained  in  it,  according  to 
the  discovery  of  Reichenbach.  This  peculiar  volatile  oil  has  so  decided  a  power  of  coag- 
ulating albumen,  that  even  the  minute  portion  of  it  present  in  pyroligneous  vinegar  is  suf- 
ficient to  preserve  animal  parts  from  putrefaction,  when  they  are  simply  soaked  in  it. 
Thus,  also,  flesh  is  cured  by  wood  smoke.  Wood  tar  likewise  protects  animal  matter 
from  change,  by  the  creosote  it  contains.  The  ordinary  pyroligneous  acid  sometimes  coiu 
tains  5  per  cent,  of  creosote. 

In  circumstances  whei-e  a  stronger  impregnation  with  this  antiseptic  oil  may  be  neces- 
saiy,  common  wood  vinegar  may  be  heated  to  167°  F.,  and  saturated  with  eflloresced 
Glauber's  saltf^,  by  which  expedient  the  oil  is  separated  and  made  to  float  upon  the  surface 
of  the  warm  liquid;  whence  it  should  be  immediately  skimmed  off;  because,  by  cooling 
and  crystallizing,  the  solution  would  so  diminish  in  density  as  to  allow  the  oil  to  sink  to 
the  bottom ;  for  its  specific  gravity  is  considerably  greater  than  that  of  water.  This  oil, 
which  contains,  besides  creosote,  some  other  volatile  constituents,  may  be  kept  dissolved 
ready  for  use  in  strong  vinegar  or  alcohol.  Water  takes  up  of  pure  creosote  only  If  per 
cent, ;  but  alcohol  dissolves  it  in  every  proportion. 

The  earthy  and  metallic  salts  afford  likewise  powerful  means  for  separating  albumen 
from  its  \vatery  solution,  their  bases  having  the  property  of  forming  insoluble  compounds 
with  it.  The  more  completely  they  produce  this  separation,  the  more  eftectually  do  they 
counteract  putrefaction.  The  alkaline  salts  also,  as  common  salt,  sal  ammoniac,  saltpetre 
and  tartar,  operate  against  putrescence,  though  in  a  smaller  degree,  because  they  do  not 
precipitate  the  albumen  ;  but,  by  abstracting  a  part  of  its  water,  they  render  it  less  liable 
to  become  putrid.  Among  the  earthy  salts,  alum  is  the  most  energetic,  as  it  forms  a  sub- 
salt  which  combines  with  albumen ;  it  is  three  times  m.ore  antiseptic  than  common  salt, 
and  from  seven  to  eight  times  more  so  than  saltpetre.  MuriatCof  soda,  however,  may  be 
employed  along  with  alum,  as  is  done  in  the  tawing  of  sheepskins. 

The  metallic  salts  operate  still  more  effectually  as  antiseptics,  because  they  form  with 
albumen  still  more  intimate  combinations.  Under  this  head  we  class  the  green  and  red 
sulphates  of  iron,  the  chloride  of  zinc,  the  acetate  of  lead,  and  corrosive  sublimate ;  the 
latter,  however,  from  its  poisonous  qualities,  can  be  employed  only  on  special  occasions. 
Nitrate  of  silver,  though  equally  noxious  to  life,  is  so  antiseptic,  that  a  solution  containing 
**"^^  yoo  ^^  ^^^  ^*^*  ^^  capable  of  preserving  animal  matters  from  corruption. 

2.  Mfiraciion  of  xvafer. — Even  in  those  cases  where  no  separation  of  the  albumen 
takes  place  in  a  coagulated  form,  or  as  a  solid  precipitate,  by  the  operation  of  a  substance 
foreign  to  the  animal  juices,  putrefaction  cannot  go  on,  any  more  than  other  kinds  of 
fermentation,  in  bodies  wholly  or  in  a  great  measure  deprived  of  their  water.  For  the 
albumen  itself  runs  so  much  more  slowly  into  putrefaction,  the  less  water  it  is  dissolved 
in ;  and  in  the  desiccated  state,  it  is  as  little  susceptible  of  alteration  as  any  other  dry 
vegetable  or  animal  matter.  Hence,  the  proper  drying  of  an  animal  substance  '  ecomes 
a  universal  preventive  of  putrescence.    In  this  way  fruits,  herbs,  cabbages,  fii^j,  flesh. 


5U 


PUTREFACTION. 


Tvln^  f  7th  B  ,  Tr  I^*^«"-  If  ^^^  *'^  ^«  »«t  cold  and  dry  enonffh  to  caase  the 
evapoiation  of  the  fluids  before  putrescence  may  come  on,  the  organic  substance  must  be 
dried  by  ar  ificial  means,  as  by  being  exposed  m  thin  slices  in  properly  constructed  air. 

rir'^h^n  hlT![^'"r;°'^'''  T  ^"  '^'  ."[^"."^^'^  •^"^^  "P  without  coagulation,  .nd 
^.^Lnffi.;  f  J  ■^''r''^'^r"/*'J^.  water,  with  its  valuable  properties  unaltered.  By 
such  artificial  desiccation,  if  flesh  is  to  be  preserved  for  cookiJig  or  boiling,  it  must  not 

like  th'rilkiir''''"'-'"  '?P '"^^  ^  ^^'''f  *^^"^'  ""^^'^  would  harden  it^ermanentl? 
^lll  R    f  "1??";!"^^^  «f  ^Sypt.     Mere  desiccation,  indeed,  can  hardly  ever  be  employ! 
^upon  flesh.     Culinary  salt  is  generally  had  recourse  to,  either  alone  or  with  the  addi- 
tion of  saltpetre  or  su^ar. 

These  alkaline  salts  abstract  water  in  their  solution,  and,  consequently,  concentrate 
the  aqueous  solution  of  the  albumen;  whence,  by  converting  the  simple  watery  fluid 
{hlVni  Jwn/'  ""au  '"  ^T'^^  less  favorable  to  the  fermentation  of  animal  matter 
tuJ  7^'^'\""^,  by  expelling  the  air,  they  counteract  putridity.  On  this  account, 
«aUed  meat  may  be  dried  in  the  air  much  more  speedily  and  safely  than  fresh  meat  The 
dr^mg  IS  promoted  by  heating  the  meat  merely  to  such  a  degree  as  to  consolidate'the  al- 
bumen,  and  eliminate  the  superfluous  water. 

Alcohol  operates  similarly,  in  abstracting  the  water  essential  to  the  putrefaction  of 
animal  substances,  taking  it  not  only  from  the  liquid  albumen,  but  counteracting  its  de- 
composition,  when  mixed  among  the  animal  solids.  Su-ar  acts  in  the  same  wav,  fixing 
in  an  unchangeable  sirup  the  water  which  would  otherwise  be  accessory  to  the  feVmenta- 
ion  of  H\e  organic  bodies.  The  preserves  of  fruits  and  vegetable  juices  are  made  upon 
this  principle.  When  animal  substances  are  rubbed  with  charcoal  powder  or  i^and,  per- 
feclly  dry,  and  are  afterwards  freely  exposed  to  the  air,  they  become  deprived  of  their 
moisture,  and  will  keep  for  any  length  of  time. 

3.  Defect  ofwarmih.-As  a  certain  degree  of  heat  is  requisite  for  the  vinous  fermenta- 
tion,  so  IS  1  for  the  putrefactive.  In  a  damp  atmos,>here,  or  in  one  saturated  with  mois- 
ture,  if  the  temperature  stand  at  from  70°  to  80°  F  ,  the  putrefaction  goes  on  most  rapidlv ; 
but  n  proceeds  languidly  at  a  few  degrees  above  freezing,  and  is  supended  altogether 'aJ 
that  point.  The  elephants  preserved  in  the  polar  ices  are  proofs  of  the  antiseptic  influ- 
ence of  low  temperature.  In  temperate  climates,  ice-houses  sen-e  the  purpose  of  keeping 
meat  fresh  and  sweet  for  any  length  of  time.  '  ^ 

4.  Mslradion  of  oxygen' gas.— As  the   putrefactive   decomposition  of  a    body  first 
commences   with    the    absorption    of   oxygen    from    the   atmosphere,  so   it    may    be 
retarded  by  the  exclusion  of  this  gas.     It  is  not,  however,  enough  to  remove  the  aerial 
oxygen  from  the  surface  of  the  body,  but  we  must  expel  all  the  oxygen  that  may  be 
diflused  among   the  vessels  and  other   solids,  as  this  portion  suffices  in  general   to 
excite    putrefaction    if  other  circumstances    be  favorable.      The    expulsion    is   most 
readily  accomplished  by  a  moderate  degree  of  heat,  which,  by  expanding  the  air,  evolves 
It  in  a  great  measure,  and  at  the  same  time  favors  the  fixation  of  the  oxygen  in  the 
extractive  matter,  so  as  to  make  it  no  longer  available  towards  the  putrefaction  of  the 
other  substances.     Milk  soup,  solution  of  gelatine,  &c.,  mav  be  kept  long  in  a  fre«;h 
state,  if  they  be  subjected  m  an  air-tight  vessel  every  other  d'ay  to  a  boiling  heat      Oxv- 
genation  may  be  prevented  in  several  ways :    by  burning  sulphur  or  phosphorus  in  the 
air  of  the  meat  receiver;    by  filling  this  with  compressed  carbonic  acid ;    or  with  oils, 
fats,  sirups,  &c.,  and  then  sealing  it  hermetically.     Charcoal  powder  recently  calcined 
IS  efficacious  in  preserving  meat,  as  it  not  only  excludes  air  from  the  bodies  surrounded 
by  It,  but  ntercepts  the  oxygen  by  condensing  it.     When  butcher-meat  is  enclosed  in  a 
Tessel  filleu  with  sulphurous  acid,  it  absorbs  the  gas,  and  remains  for  a  considerable  time 
proof  against  corruption.     The  same  result  is  obtained  if  the  vessel  be  filled  with  ammo- 
niacal  gas.     At  the  end  of  76  days  such  meat  has  still  a  fresh  look,  and  may  be  safely 
dried  in  the  atmosphere.  '  '       oai^ij 

II.  PECULIAR  ANTISEPTIC  PROCESSES. 

Upon  the  preceding  principles  and  experiments  depend  the  several  processes  er.'ployed 
for  protecting  substances  from  putrescence  and  corruption.  Here  we  must  distinguish 
between  those  bodies  which  may  be  preserved  by  any  media  suitable  to  the  purpose,  as 
•naomical  preparations  or  objects  of  natural  history,  and  those  bodies  which,  being  in- 
tended  for  food,  cari  be  cured  only  by  wholesome  and  agreeable  means 

A  common  method  for  preserving  animal  substances  unchanged  in  property  and 
texture,  is  to  immerse  them  in  a  spirituous  liquor  containing  about  65  or  70  per  cent 
of  real  alcohol.  Camphor  may  also  be  dissolved  in  it,  and  as  much  common  silt  as  its 
water  will  take  up.  A  double  fold  of  ox-bladder  should  be  bound  over  the  mouth  of 
the  vessel  m  order  o  impede  the  evaporation  of  the  watery  portion  of  the  liquid,  and  its 
Tipper  surface  should  be  coated  with  a  turpentine  varnish.  Undoubtedly  a  little  creo- 
•ote  would  be  of  use  to  counteract  the  decomposing  influence  of  the  alcohol  upon  *kc 


PUTREFACTION. 


5U 


. 


itiimal  substances.  With  such  an  addition,  a  weaker  spirit,  containing  no  more  than  30 
per  cent,  of  alcohol,  would  answer  the  purpose. 

Instead  of  alcohol,  a  much  cheaper  vehicle  is  water  saturated  with  sulphurous  acid; 
and  if  a  few  drops  of  creosote  be  added,  the  mixture  will  become  very  efficacious.  A 
solution  of  red  sulphate  of  iron  is  powerfully  antiseptic ;  but  after  some  time  it  gives  a 
deposite  of  the  oxyde,  which  disguises  the  preparation  in  a  great  degree. 

According  to  Tauffier,  animal  substances  may  be  preserved  more  permanently  by  a 
solution  of  one  part  of  chloride  of  tin  in  20  parts  of  water,  sharpened  with  a  little  muriatic 
acid,  than  even  by  alcohol. 

For  preserving  animal  bodies  in  an  embalmed  form,  mummy-like,  a  solution  of 
chloride  of  mercury  and  wood  vinegar  is  most  efficacious.  As  there  is  danger  ia 
manipulating  with  that  mercurial  salt,  and  as  in  the  present  state  of  our  knowledge  of 
creosote  we  have  it  in  our  power  to  make  a  suitably  strong  solution  of  this  substance  in 
vinegar  or  spirit  of  wine,  I  am  led  to  suppose  that  it  will  become  the  basis  of  most  an- 
tiseptic preparations  for  the  future.  From  the  statements  of  Pliny,  it  is  plain  that  wood 
vinegar  was  the  essential  means  employed  by  the  ancient  Egyptians  in  preparing  their 
mummies,  and  that  the  odoriferous  resins  were  of  inferior  consequence.  ** 

CURING  OF  PROVISIONS. 

Flesh.— The  ordinary  means  employed  for  preserving  butcher  meat  are,  drying,  smoking 
salting,  and  pickling  or  souring.  ** 

Drying  of  animal  Jihre.— The  best  mode  of  operating  is  as  follows  :— The  flesh  must 

be  cut  into  slices  from  2  to  6  ounces  in  weight,  immersed  in  boiling  water  for  5  or  6 

minutes,  and  then  laid  on  open  trellis-work  in  a  drying-stove,  at  a  temperature  kept 

steadily  about  122°  F.,  with  a  constant  stream  of  warm  dry  air.     That  the  boiling  water 

may  not  dissipate  the  soluble  animal  matters,  very  little  of  it  should  be  used,  just  enough 

for  the  meat  to  be  immersed  by  portions  in  succession,  whereby  it  will  speedily  become 

a  rich  soup,  fresh  water  being  added  only  as  evaporation  takes  place.     It  is  advanta«'e- 

ous  to  add  a  little  salt,  and  some  spices,  especially  coriander  seeds,  to  the  water.    After 

the  parboiling  of  the  flesh  has  been  completed,  the  soup  should  be  evaporated  to  a  ffela- 

tinous  consistence,  in  order  to  fit  it  for  forming  a  varnish  to  the  meat  after  it  is  dried, 

which  may  be  completely  eflTected  within  two  days  in  the  oven.     By  this  process  two 

thirds  of  the  weight  is  lost.     The  perfectly  dry  flesh  must  be  plunged  piece  by  piece  in 

the  fatty  gelatinous  matter  liquefied  by  a  gentle  heat ;    then  placed  once  more  in  the 

stove,  to  dry  the  layer  of  varnish.    This  operation  may  be  repeated  two  or  three  times, 

in  order  to  render  the  coat  sufficiently  uniform  and  thick.    Butcher's  meat  dried  in  thS 

way  keeps  for  a  year,  affijrds,  when  cooked,  a  dish  similar  to  that  of  fresh  meat  and  is 

therefore  much  preferable  to  salted  provisions.     The  drying  may  be  facUitated,  so  that 

larger  lumps  of  flesh  may  be  used,  if  they  be  imbued  with  some  common  salt  immediately 

after  the  parboiling  process,  by  stratifying  them  with  salt,  and  leaving  them  in  a  proper 

pickling-tub  for  12  hours  before  they  are  transferred  to  the  stove.     The  first  method 

however,  aflfords  the  more  agreeable  article.  ' 

5mofeing.— This    process   consists   in    exposing  meat   previously   salted,   or  merely 

rubbed  over  with  salt,  to  wood  smoke,  in  an  apartment  so  distant  from  the  fire  as  not  to 

be  unduly  heated  by  it,  and  into  which  the  smoke  is  admitted  by  flues  at  the  bottom  of 

the  side  walls.     Here  the  meat  combines  with  the  empyreumatic  acid  of  the  smoke,  and 

gets  dried  at  the  same   ime     The  quality  of  the  wood  has  an  influence  upon  the  smell 

and  taste  of  the  smoke-aried  meat;   smoke  from  beech  wood  and  oak  being  preferable  to 

that  froni  fir  and  larch.     Smoke  from  the  twigs  and  berries  of  juniper,  from  rosemary. 

peppermint,  &c.,  imparts  somewhat  of  the  aromatic  flavor  of  these  plants.     A  slow 

smoking  With  a  slender  fire  is  preferable  to  a  rapid  and  powerful  one,  as  it  allows  the 

empyreumatic  principles  time  to  penetrate  into  the  interior   substance,  without  drying 

Si  «"  n^^  •°*'  T.I'    ^ir!"^'"'  '^^.^  ^•'°'°  attaching  itself  to  the  provisions,  they  maf 

Sf  the  op^eliron         "*'  *'''"'  ^'^"'  "^^^"^  "^^^  ^  easily  removed  at  the  end 

vnlTni:n'I1th''V°"  v'k'  ^^^^f^  "P^"  *^^  ^^^'^"^  «^  ^^^  ^«o^  «cid>  or  the  creosote 
volatilized  with  it  which  operates  upon  the  flesh.     The  same  change  may  be  produced 

in  a  much  shorter  time  by  immersing  the  meat  for  a  few  hours  in  pyrSligneous  acid,  then 

hanging  it  up  in  a  diy  air,  which,  though  moderately  warm,  makes  it  fit  for  keeping, 

rj.l^r«n7^;hrrl 'h  '"'fr''-  i^^^'*  ^/^^  ^^^^  ^^-^P^^^"--  ^^  loses  the  empyreu^atfe 
smell,  and  then  resembles  thoroughly  smoked  provisions.  The  meat  dried  in  this  way 
is  in  general  somewhat  harder  than  by  the  application  of  smoke,  and  therefore  softens 
ess  when  cooked,  a  diff-erence  to  be  ascribed  to  the  more  sudden  and  concentrated  opeim- 
tion  of  the  wood  vinegar,  which  effects  m  a  few  hours  what  would  require  smokinrfor 
several  weeks.  By  the  judicious  employment  of  pyroligneous  acid  diluted  to  successive 
degrees,  we  migU  probably  succeed  in  imitating  perfectly  the  eflfect  of  smoke  in  curuuf 
provisiCTis.  ^ 


\r 


516 


PUTREFACTION. 


Salting.--.The  meat  should  be  rubbed  well  with  common  salt,  containing  about  one 
sixteenth  of  saltpetre,  and  one  thirty-secondth  of  sugar,  till  every  crevice  has  been  im- 
pregnated  with  Jt;  then  sprinkled  over  with  salt,  laid  down  for  24  or  48  hours,  and, 
lastly,  subjected  to  pressure.  It  must  next  be  sprinkled  anew  with  salt,  packed  into 
proper  vessels,  and  covered  with  the  brine  obtained  in  the  act  of  pressing,  rendered 
stronger  by  boiling  down.  For  household  purposes  it  is  sufficient  to  rub  the  meat  well 
with  good  salt,  to  put  It  into  vessels,  and  load  it  with  heavy  weights,  in  order  to  squeeze 
out  as  much  pickle  as  will  cover  its  surface.  If  this  cannot  be  had,  a  pickle  must  be 
pour«l  on  It,  composed  of  4  pounds  of  salt,  1  pound  of  sugar,  and  2  oz.  of  saltpetre,  dis- 
solved in  2  gallons  of  water.  o«»  p^w  ,  «*»- 

Pickling  with  vinegar.—YinegHT  dissolves  or  coagulates  the  albumen  of  flesh,  and  there- 
by counteracts  Us  putrescence.  The  meat  should  be  washed,  dried,  and  then  laid  in  strong 
vinegar.  Or  it  may  be  boiled  in  the  vinegar,  allowed  to  cool  in  it,  and  then  set  aside  with 
It  in  a  cold  cellar,  where  it  will  keep  sound  for  several  months. 

Fresh  meat  may  be  kept  for  some  months  in  water  deprived  of  its  air.  If  we  strew  on 
the  bottom  of  a  vessel  a  mixture  of  iron  filings  and  flowers  of  sulphur,  and  pour  over  them 
some  water  which  has  been  boiled,  so  as  to  expel  its  air,  meat  immersed  in  it  will  ke-p 

fh-  !;°  r^  -n^  V^^^.  ^  ''^''^^^'^  "^'^^  *  ^*y«^  «^  oi''  ^''o°»  half  an  inch  to  an  inS 
thick.  Meat  will  also  keep  fresh  for  a  considerable  period  when  surrounded  with  oil. 
or  lat  of  any  kind,  so  purified  as  not  to  turn  rancid  of  itself,  especially  if  the  meat  be 
fowls  &J  ^^^^^^^  '^  ^*"^*^  potting,  and  is  applied  successfuUy  to  fish, 

Prechtl  says  that  living  fish  may  be  preserved  14  days  without  water,  by  stopping  their 
mouths  with  crumbs  of  bread  steeped  in  brandy,  pouring  a  little  brandy  into  them,  and 
packing  them  in  this  torpid  state  in  straw.  When  put  into  fresh  water,  they  comealivc 
again  after  a  few  hours  !     Prechtl,  Encyclop.  Technologisches,  art.  Faiilniss  Mhaliung. 

Agg*.— These  ought  to  be  taken  new  laid.  The  essential  point  towards  their  pre- 
servation is  the  exclusion  of  the  atmospheric  oxygen,  as  their  shells  are  porous,  and  per- 
init  the  external  air  to  pass  inwards,  and  to  excite  putrefaction  in  the  albumen.  There 
IS  also  some  oxygen  always  in  tlie  air-cell  of  the  eggs,  which  ought  to  be  expelled  or  ren- 
dered  inoperative,  which  may  be  done  by  plunging  Ihem  for  5  minutes  in  water  heated  to 
140"  h .  The  eggs  must  be  then  taken  out,  wiped  dry,  besmeared  with  some  oil  (not  apt 
to  turn  rancid)  or  other  unctuous  matter,  packed  into  a  vessel  with  their  narrow  ends  up- 
permost, and  covered  with  sawdust,  fine  sand,  or  powdered  charcoal.  Eggs  coated  with 
gum  arable,  and  packed  in  charcoal,  will  keep  fresh  for  a  year.  Lime  water,  or  rather 
mUk  of  lime,  is  an  excellent  vehicle  for  keeping  eggs  in,  as  I  have  verified  by  long  expe- 
rience. Some  persons  coagulate  the  albumen  partially,  and  also  expel  the  air  by  boilin- 
the  eggs  for  2  minutes,  and  dnd  the  method  successful.  When  eggs  are  intended  fo? 
hatching,  they  should  be  kept  in  a  cool  cellar ;  for  example,  in  a  chamber  adjoining  an 
ice-house.  Eggs  exposed,  in  the  holes  of  perforated  shelves,  to  a  constant  current  of  air, 
lose  about  |  of  a  gram  of  their  weight  daUy,  and  become  concentrated  in  their  albuminous 
l)art,  so  as  to  be  little  liable  to  putrefy.  For  long  sea  voyages,  the  surest  means  of  pre- 
serving  eggs,  is  to  dry  up  the  albumen  and  yolk,  by  first  triturating  them  into  a  homoge- 
neous paste,  then  evaporating  this  in  an  air-slove  or  a  water-bath  heated  to  125°.  and 
putting  up  the  dried  mass  in  vessels  which  may  be  made  air-tight.  When  used,  it  should 
be  dissolved  in  three  parts  of  cold  or  tepid  water. 

•  i^!?'".  "*[  ^"  kinds,  as  wheat,  barley,  rye,  &c.,  and  their  flour,  may  be  preserved  for  an 
indefinite  lengh  of  time,  if  they  be  kiln-dried,  put  up  in  vessels  or  chambers  free  from 
damp  and  excluded  from  the  air.     Well  dried  grain  is  not  liable  to  the  depredaUons  of 

To  preserve  fruits  in  a  fresh  state,  various  plans  are  adopted.  Pears,  apples,  plums, 
*c.  Should  be  gathered  in  a  sound  state,  altogether  exempt  from  bruises,  and  plucked,  in 
dry  weather,  before  they  are  fully  ripe.  One  mode  of  preservation  is,  Xo  expose  them  in 
an  airy  place  to  dry  a  little  for  eight  or  ten  days,  and  then  to  lay  them  in  dry  sawdust 
or  cnoppeu  straw,  spread  upon  shelves  in  a  cool  apartment,  so  as  not  to  touch  each  other. 
Another  method  consists  in  surrounding  them  with  fine  dry  sand  in  a  vessel  which  should 

^Jv  LT  'u'^^""^  ^^P'  I"  *  """^^  »'**"•  ^""^  Pe^'sons  coat  the  fruit,  including  their 
stalks,  with  melted  wax ;  others  lay  the  apples,  &c.,  upon  wicker-work  shelves  in  a  vault- 
ed  chamber,  f^^  smoke  them  daily  during  4  or  5  days  with  vine  branches  or  juniper  wood. 
Apples  thus  treated,  and  afterwards  stratified  in  dry  sawdust,  without  touching  each  other, 
will  keep  fresh  for  a  whole  year. 

The  drying  of  garden  fruits  in  the  air,  or  by  a  kiln,  is  a  well-known  method  of  preser- 
vation Apples  and  peaiy  of  large  size  should  be  cut  into  thin  slices.  From  5  to  6  meas. 
lire?  of  fresh  apples,  and  from  6  to  7  of  pears,  affbrd  in  general  one  measure  of  dry  fruit, 
(biffins).     Dried  plums,  grapes,  and  currants  are  a  common  article  of  commerce. 

Herbs,  cabbages,  &c.,  may  be  kept  a  long  time  in  a  cool  cellar,  provided  they  are 
eovered  with  dry  sand.    Such  vegetables  are  in  general  preserved  for  the  parpoMS  o( 


PUTREFACTION. 


617 


food,  by  means  of  drying,  salting,  pickling  with  vinegar,  or  beating  up  with  sugar.  Cab. 
bages  should  be  scalded  in  hot  water  previously  to  drying ;  and  aU  such  plants,  when 
dned,  should  be  compactly  pressed  together,  and  kept  in  air-tight  vessels.  Tuberous  and 
other  roots  are  better  kept  in  an  airy  place,  where  they  may  dry  a  little  without  being  ex- 
posed to  the  winter's  frost. 

A  partial  drying  is  given  to  various  vegetable  juices  by  evaporating  them  to  the  con- 
sistence of  a  sirup,  called  a  rob,  in  which  so  much  of  the  water  is  dissipated  as  to  prevent 
them  from  running  into  fermentation.  The  fruits  must  be  crushed,  squeezed  in  bags  tc 
expel  (he  juices,  which  must  then  be  inspissated  either  over  the  naked  fire,  or  on  a  watcx 
or  steam  bath,  in  the  air  or  in  vacuo.  Sometimes  a  small  proportion  of  spices  is  added, 
which  tends  to  prevent  mouldiness.  Such  extracts  may  be  conveniently  mixed  with  sugar 
into  what  are  called  conserves. 

Salting  is  employed  for  certain  fruits,  as  small  cucumbers  or  gherkins,  capers,  olives, 
tc.  Even  for  peas  such  a  method  is  had  recourse  to,  for  preserving  them  ascertain 
time.  They  must  be  scalded  in  hot  water,  put  up  in  bottles,  and  covered  with  satuiated 
brine,  having  a  film  of  oil  on  its  surface,  to  exclude  the  agency  of  the  atmospheric  air. 
Before  being  used,  they  must  be  soaked  for  a  short  time  in  warm  water,  to  extract  the 
salt.  The  most  important  article  of  diet  of  this  class,  is  the  sour  kraut  of  the  northern 
nations  of  Europe  (made  from  white  cabbage),  which  is  prepared  simply  by  salting ;  a 
little  vinegar  being  formed  spontaneously  by  fermentation.  The  cabbage  must  be  cul 
into  small  pieces,  stratified  in  a  cask  along  with  salt,  to  which  juniper  berries  and  carui 
seeds  are  added,  and  packed  as  hard  as  possible  by  means  of  a  wooden  rammer.  The 
cabbage  is  then  covered  with  a  lid,  on  which  a  heavy  weight  is  laid.  A  fermentation 
commences,  which  causes  the  cabbage  to  become  more  compact,  while  a  quantity  of  juice 
exudes  and  floats  on  the  surface,  and  a  sour  smell  is  perceived  towards  the  end  of  the 
fermentation.  In  this  condition  the  cask  is  transported  into  a  cool  cellar,  where  it  is 
allowed  to  stand  for  a  year ;  and  indeed,  where,  if  well  made  and  packed,  it  may  be  kept 
for  several  years. 

The  excellent  process  for  preserving  all  kinds  of  butcher  meat,  fish,  and  poultry,  first 
contrived  by  M.  Appert  in  France,  and  afterwards  successfully  practised  upon  the  great 
commercial  scale  by  Messrs.  Donkin  and  Gamble,  for  keeping  beef,  salmon,  soups^  &c. 
perfectly  fresh  and  sweet  for  exportation  from  this  country,  as  also  turtle  for  importation 
thither  from  the  West  Indies,  deserves  a  brief  description. 

Let  the  substance  to  be  preserved  be  first  parboiled,  or  rather  somewhat  more,  the 
bones  of  the  meat  being  previously  removed.  Put  the  meat  into  a  tin  cylinder,  fill  up 
the  vessel  with  seasoned  rich  soup,  and  then  solder  on  the  lid,  pierced  with  a  small  hole. 
When  this  has  been  done,  let  the  tin  vessel  thus  prepared  be  placed  in  brine  and  heated 
to  the  boiling  point,  to  complete  the  remainder  of  the  cooking  of  the  meat.  The  hole 
«f  the  lid  is  now  to  be  closed  perfectly  by  soldering,  while  the  air  is  rarefied.  The  vessel 
it  then  allowed  to  cool,  and  from  the  diminution  of  the  volume,  in  consequence  of  the 
reduction  of  temperature,  both  ends  of  the  cylinder  are  pressed  inwards,  and  become  con- 
cave. The  tin  cases,  thus  hermetically  sealed,  are  exposed  in  a  test-chamber,  for  at  least 
a  month,  to  a  temperature  above  what  they  are  ever  likely  to  encounter;  from  90=  to  11(^ 
of  Fahrenheit.  If  the  process  has  failed,  putrefaction  takes  place,  and  gas  is  evolved 
which,  in  process  of  time,  will  cause  both  ends  of  the  case  to  bulge,  so  as  to  render  them 
convex,  instead  of  concave.  But  the  contents  of  those  cases  which  stand  the  test  win 
infallibly  keep  perfectly  sweet  and  good  in  any  climate,  and  for  any  number  of  years  If 
there  be  any  taint  about  the  meat  when  put  up,  it  inevitably  ferments,  and  is  detected  ia 
the  proving  process.     Mr.  Gamble's  turtle  is  delicious. 

This  preservative  process  is  founded  upon  the  fact,  that  the  small  quantity  of  oxveen 
contained  withm  the  vessel  gets  into  a  state  of  combination,  in  consequence  of  the  high 
temperature  to  which  the  animal  substances  are  exposed,  and  upon  the  chemical  principle, 
that  free  oxygen  is  necessary  as  a  ferment  to  commence  or  give  birth  to  the  process  of 
putrefaction. 

I  shall  conclude  this  article  with  some  observations  upon  the  means  of  preserving 
water  fresh  on  sea  voyages.  When  lone  kept  in  wooden  casks,  it  undergoes  a  kind  of 
putrefaction,  contracts  a  disagreeable  sulphurous  smell,  and  becomes  undrinkable.  The 
influence  of  the  external  air  is  by  no  means  necessary  to  this  change,  for  it  happens  in 
close  vessels  even  more  readily  than  when  freely  exposed  to  the  atmospherical  oxveen. 
The  origin  of  this  impurity  lies  in  the  animal  and  vegetable  juices  which  the  Water 
originally  contained  in  the  source  from  which  it  was  drawn,  or  from  the  cask,  or  insects, 
&c.  These  matters  easily  occasion,  with  a  sufficient  warmth,  fermentation  in  the  stag- 
nant water,  and  thereby  cause  the  evolution  of  oflTensive  gases.  It  would  appear  that 
the  gypsum  of  hard  waters  is  decomposed,  and  gives  up  its  sulphur,  which  aggravates  the 
disagreeable  odor ;  for  selenitic  waters  are  more  apt  to  take  this  putrid  taint,  than  those 
which  contain  merely  carbonate  of  lime. 

As  the  corrupted  water  has  become  unfit  for  use  merely  in  consequence  of  the  admu 


518 


PYROGALLIC  ACID. 


^^i^L  •  TIJ  °*"^"'  ^?''  '^^*^'  ^"  ^^^^'^  i«  "ot  liable  to  corruption,  so  it  roar  on 
purified  again  by  their  separation.     This  purification  may  be  accomplish^  most  eLilr 

d^J^nTl  '\^"'T  i!l'-«"^V<^h«'-<^o«I  powder,  or  throu^Hh^powder  of  rS 
Sltclt  S^fato  th;  J*"'  <^-bon  takes  away  not  only  the  finely  diffused  coVrnpt 
Sm  about  ^0  drnn!  "tn  T'  '""TT'' ■  ^^  ^^^^"^  *°  '^^  ^^*^"  «  ^^^-^  l^^le  sulphurk 
b^iaved  Undoubted  V  f,  P°"f  ?;  L«witz  says  that  tv.o  thirds  of  the  charcoal  may 
oe  saved.     iJndoubtedly  the  sulphuric  acid  acts  here,  as  in  other  similar  casp«!    hi 

Lnd  r°T'^''"';/"^  '"P"™*^""  '^''''  albuminous  matters,  combing  wiiHfi^^ 
and  rendering  them  more  apt  to  be  seized  by  the  charcoal.     A  more  effectual  aS 

^  lA'^T^'f '?  ^.^  ^^^"^  ^"^^''  ^^  '^  ^'  ^«""d  »"  ^l"'"-  A  drachm  of  pound^  a!um 
should  be  dissolved  with  agitation  in  a  gallon  of  the  water,  and  then  left  to  S"Quie"S 

may  L  'p^'r'ed  tfT^^'rHT !""'''  ''  'u'  "^1^"™'  "'L"1^'^  ^"^''^  ^^-'"^^  clea^r  atT,  and 
may  be  poured  off.     The  alum  combines  here  with  the  substances  dissolved  in  the  water 

as  it  does  with  the  stuffs  in  the  dyeing  copper.  In  order  to  decompose  any  alum  w h  ch 
Sd^  to  ii."  '"  ""'     '  equivalent  quantity  of  crystals  of  carbonate  o/s^a  may  ^ 

The  red  sulphate  of  iron  acts  in  the  same  way  as  alum.     A  few  drops  of  its  solution 
are  sufficient  to  purge  a  pound  of  foul  water.     The  foreign  matters  dissofved  in  the  wa^^^^^^^ 
which  occasion  putrefaction,  become  insoluble,  in  consequence  of  oxydizement  Iike7e-e 
teble  extractive,  and  are  precipitated.     On  this  accounlTalso,  foul  water  may  be  purifif? 
frlsh"aT'so'S'.n"r  \''r'^' '^  with  bellows,  or  by 'agitating  it  TLma'ct  S 

fluencP  nVll  a'  ^?'^-^^  *'^  ^""^'^^  *°  ^^y^^"'     ^^""^  ^«  ^^^  explain  the  in- 

fluence  of  streams  and  winds,  m  counteracting  the  corruption  of  water  exposed  to  them 

Chlorine  acts  still  more  energetically  than  the  air  in  purifying  water.  A  Httle  aqueout* 
^l^aTe:  itt  m^ilTe^"'  ^^  '''  ^^^"^"-^  ^'  ^  ""^«  ^—  chlorinelr^o^uTh  ?C 
Water-casks  ought  to  be  charred  inside,  whereby  no  fermentable  stuff  will  be  extract- 
or Sn'.r^*  ,^"'''?  '^'P^'  ''^^"^^'•'  *^^  "°^  ^«"°^«'»^y  provided  with  i^on  t?nk; 
for  holdins  their  water  in  lonsr  vovages. 

is  nSuS' if^oTpt    bisulphuretof  iron.     Copper  pyrites,  called  Culgarly  mundick, 

Jlm'sfGlJi^,  '  Tv'";-  (f  *^-' /'y-^-i^'^^.  -Acetone,  Fr. ;  Brennzlicher  Essig. 
geist  Mesit,  Germ  )  This  liquid  was  discovered  and  described  by  Chenevix  Ion-  before 
pyrohgmaus  spirit  was  known.  It  may  be  obtained  by  subjecin-  to  drv  disUllf Hon 
the  acetates  of  copper,  lead,  alkalis,  and  earths;  and  a  J  it  is  formed  esp7cialydun^ 
thesecond  half  of  the  process,  the  liquor  which  comes  over  then  should  brset  anaJu 
separated  by  decantation  from  the  empyreumatic  oil,  and  distilled  a  second  t  me  by 
the  heat  of  a  water-bath.  The  fine  light  fluid  which  now  comes  over  first,  is  to  be 
rectified  along  with  carbonate  of  potassa,  or  chloride  of  calcium.  As  pyro-acetic  sniril 
usually  retains,  even  after  repeated  distillations,  a  disagreeable  empvreumatic  smelf  like 
r^-'  H  ^'k^'T'^  bone-black  should  be  employed  in  its  final  recUfication  Tccord  ng 
to  Reichenbach,  pyro-acetic  spirit  may  be  extracted  in  considerable  quantity  from  beech 

?„'•     ^f^'i^K""^'  T'^'-^     P'  '^''"'  '•^"^  P^^P^^^^  '^  «  ^«l«rl^«s  limpid  ?"ufd  of 

^crid  and  burning  taste  at  first,  but  afterwards  cooling;    of  a  penetrating  aromatic 

smdl,  different  from  that  of  alcohol ;    of  the  spec,  gravity  0-7921   at  60°  R.^b^iH^  a^ 

fA\lo^  remaining  fluid  at  5°.     It  consists  ultimately  of-carbon,  62-148     hvdrL 

gen,  10-453  ;  oxygen  27-329 ;  or,  of  1  proportion  of  carbonic  acid  +  2  prop  of  o'efian^ 

f^'  t  ^'Z  ''^^''^'''  ?''  ^  P^'^P-  ^^  «'"''"  ^^'^  -  ^  P'-^P-  «<•  carbonic  acid.  AccorO^ 
i^488  TnuZ  "'''"'  !!  •'  ^P'^Pf  H«f  51-52  parts  of  concentrated  acetic  acid,  and 
48^488  of  oil  of  wine,  being  double  of  the  quantity  in  acetic  ether.  It  is  very  combu^ 
tible,  anu  brims  with  a  brilliant  flame,  without  smoke.  When  treated  by  chSeU 
llonl  T  fif"  ''^\''-  ^y^'^^^'^'  ^"d  absorbs  2  atoms  of  chlorine.  It  is  soluble  in  watVj 
alcohol,  ether,  and  is  not  convertible  into  ether  h,r  strong   sulphuric  acid.     It  is  u.^' 

luflened    ""^         '"''"'  commonly  called  gums,  with  which  the  bodies  of  hats  a^ 

PYROGALLIC  ACID,  and  sotne  astringent  substances  which  yield  it.  To  procure 
the  pyrogallic  acid  for  examination,  powdered  nutgalls  are  treated  with  water;  which 
w  evaporated  until  an  extract  resembling  catechu  is  obtained,  which  being  sublimed 
in  Mohr  8  apparatus  gives  about  10-3  per  cent,  of  pure  crystals  of  the  acid.  By  aaalvsis 
It  was  found  that  0-312  yielded  065  carbonic  acid,  and  0-1345  water;  thia  would  to 


8  carbon 
4  hydrogen 
4  oxygen 


611-480  calculated  67-61 

49-918        do  4-70 

400000        do         87-69 


found  57'60 
do  4-78 
do     37-62 


PYROGALLIC  ACID. 


519 


In  exanaining  the  substances  which  yield  pyrogallic  acid,  Stenhouse  states,  that  he 
TOuld  obtain  pure  tannin  only  from  nutgalls,  let  his  process  be  ever  so  carefully  conducted 
Pure  tannm  and  gallic  acid  are  the  only  substances  which  are  known,  by  distillation,  to 
yield  pyrcgalhc  acid.  Taking  advantage  of  this  circumstance,  he  proceeded  to  test 
various  substances  for  the  presence  of  gallic  acid,  and  to  examine  whether  the  tannin 
they  contain  is  the  same  as  that  of  nutgalls. 

Sumach.  Sumach,  obtained  from  the  small  branches  of  Rhus  coriaria,  was  digested 
m  hot  water,  filtered,  evaporated,  and  subjected  to  distillation.  The  flqid  distilled  over 
into  the  receiver  gave  no  crystals  of  pyrogallic  acid  (owing  to  the  empyreumatic  oil 
and  impurities  passing  over  with  it);  but  it  evidently  contained  the  acid  and  tannin, 
similar  to  that  of  nutgalls,  an  hypothesis  which  his  subsequent  analysis  verified,  for 
after  treating  a  watery  extract  with  alcohol,  and  again  with  ether,  he  obtained  pure 
colourless  crystals,  which  answered  to  the  qualities  of  gallic  acid,  and  on  distillation 
yielded  pyrogallic  acid. 

The  tannin  freed  from  gallic  acid,  subjected  to  distillation,  yielded  as  much  pyrogallic 
acid  as  the  same  quantity  obtained  from  nutgalls  would  have  given.  He  also  succeeded 
in  converting  the  tannin  of  sumach  into  gallic  acid,  by  boiling  it  with  dilute  sulphuric 
acid.  In  treating  tannin  precipitated  from  sumach  by  sulphuric  acid  with  alcohol 
and  ether,  he  procured  crystals  of  gallic  acid ;  sumach,  therefore,  most  closely  resembles 
nutgall,  for  which  it  has  long  been  a  substitute  in  the  arts.  The  quantity  of  tannin  it 
contains  is,  however,  considerably  less. 

Valonia.  The  acorn  of  Quercus  cegilops.  Dried  extract  of  valonia  gave  on  distilla- 
tion no  signs  of  pyrogallic  acid:  a  concentrated  solution  was  precipitated  by  size— the 
fluid  was  evaporated— the  extract  boiled  with  alcohol— the  alcohol  distilled  over— and 
the  extract  treated  with  ether,  yielding  a  small  quantity  of  crystals  having  the  properties 
of  gallic  acid,  which,  on  distillation,  gave  pyrogallic  acid,  but  in  very  limited  quantity, 
alwut  oiie-thirtieth  of  that  of  sumach.  The  solution  of  valonia,  treated  with  sulphuric 
acid,  gave  but  a  trifling  precipitate  of  tannin ;  distilled,  it  gave  much  charcoal,  but  no 
empyreumatic  products.  The  fluid  in  the  receiver  was  colourless,  and  had  no  traces  of 
pyrogalhc  acid.     The  tannin  of  valonia  differs  materially  from  that  of  nutgalla 

Oak-Bark.  The  extract,  treated  as  the  former,  gave  no  traces  of  pyrogallic  acid  •  even 
in  subjecting  large  quantities  of  a  decoction  to  examination,  he  could  not  obtain  crystals 
of  gal  10  acid,  which  he  concludes  to  exist  in  it  in  very  minute  quantities,  if  it  exist  in 
"•  ,.,V^^.  ^""^?  precipitated  by  sulphuric  acid  yielded  no  traces  of  pyrogallic  acid  on 
distillation,  and  appears,  therefore,  to  differ  from  that  of  nutgalls. 

i>it;t-i>iwi,  imported  from  Carthagena,  is  the  pod  of  a  leguminous  shrub,  the  Ccesal- 
pima  cortaria  according  to  Balfour.  The  extract,  subjected  to  distillation,  yields  no 
traces  of  pyrogallic  acid ;  but  the  fluid,  passing  over  into  the  receiver,  has  its  character- 
istic  signs  By  treating  m  the  manner  above  mentioned,  pure  crystals  of  gallic  acid 
may  be  obtamed  from  it  which,  on  distillation,  yield  pyrogallic  acid.  Sulphuric  acid 
gave^  with  a  concentrated  solution,  but  a  very  small  precipitate,  which,  dried  and  dis- 
tilled, yielded  no  trace  of  pyrogallic  acid,  but  much  charcoal.  Thence  the  tannin  of 
divi-divi  diff-ers  materially  from  that  of  nutgall.  The  quantity  of  mucilage  which  it 
contains  prec  udes  it  from  the  use  of  dyers;  but  as  it  contains  much  tanninlt  is  lar-elr 
used  for  tanning.  '  *~o^»j 

Kino.  From  the  African  kino  he  could  obtain  neither  gallic  acid,  nor  did  the  abun- 
dant precipitate  produced  by  sulphuric  acid,  on  distillation,  show  any  traces  of  pyro- 
gallic acid ;  nitric  acid  converted  it  into  oxalic  acid.  ^^ 

Catechu  Catechu  contained  no  gallic  acid,  but  catechu  and  a  peculiar  tannin,  which 
18  precipitated  by  sulphuric  acid  and  when  boiled  with  dilute  sulphuric  acid  is  of  a 
dark  brown  colour,  ike  the  tannin  of  oak-bark.  It  is  insoluble  in  cold  or  hot  water 
alcohol,  or  ether  and  but  trivially  soluble  in  a  solution  of  strong  alka Us.  DistilT^Ti 
gave  no  traces  of  pyrogallic  acid  or  pyrocatechin  xjiBuuea,  u 

cat^echi^?  zt'en^^^^  '^'""^^  ''''"^"^^"  ^°  '"^^  ^^*^''  ^''^^'  «°  distillation  the  pyro- 
Salicin.     Charies   Gerhardt  was    induced  again   to   undertake  the  analvsis  of  this 

lllld'strli."  '"'"'  '^  '^'  modification  of  lie  atomic  numtr  of  car£^^by  Du^ 
In  100  parts  he  found 


Carbon 
Hydri^en  - 
Oxygen     - 


I 

IL 

65-28 

55-24 

6-50 

6-63 

38-22 

38-23 

1061-898 


100-00 


lOOlM) 


100-00 


10000 


m 


u 


(If  ! 


i 


PYROLIGNOtrS  ACID. 


He  quotienU  of  th««  number^  dialed  by  the  .tomic  w.ighl^  .„, 


Carbon 

Hydrogen 

Oxygen 


At 

1474 
1040 
882 


48 
28 
22 


in  100  ports 
55-3 
6-2 
S8-5 


PTROLTGNITE  OF  LEAD  tk«  «  r 
•f  sugar  of  lead,  ought  to  l^  tolerabfv^JJe&L"'''^  ^^^^^^^^  '"  *^«  manufacfnre 
Jield  a  good  product^  The  manVfacturerrof  TrS^'^"^^^^^^^  substances,  in  order  to 
name  of  rauriute  of  lead)  a  produc^^whTch  is  ve7v  h^^^^^^  ^"'°'^*^  <*^^^«»  ""^^^  t^* 

tares,  and  which  ia  prepare/bv  satumtW  ^tlf  ^  brown  by  these  empyreumatic  adraix- 
printing.  sugar  of  iLd'ia  lieLu^^tr^^tlT".-''^  T'^'  ^'''^^'^-  I"  clyeing^nd 
impure  sugar  of  lead  is  prejuSi^r^  the  morH^  ^''''"  ?^  *^^*^*^  ^^  alumi/a;  but  as 
pared  from  alcohol  vinegar  ^aioneLe^^l^^^^^^^  ^"  r^^.  P^^e  sugar  of  le'ad.  pre- 
yellow.  chrome  orange,  ^  ^  employed  for  these,  as  weU  as  for  chrome 

4t  obSS^p^^Str  ^^^^^  f  r  ^  ^^  -^-»^  the  sugar  of  lead 

The  rough  Pyrolignous'^S  Ts  ^1.6^  h,  the t^l  ^^^^^^^^ 

riaked  lime,  and  exposed  to  the  air  for  V  if.  i  ^  "°^';  .t*"^"  supersaturated  with 
frecjuently  stirred  up^  By  the  ex^l  of  1L.TI  *;"°S^,^J'<^J  *!«««  the  mass  is  to  be 
Jbich  forms  with  the  limeVmore  or  ess^^^^^^^  the  empyreumatic  matter. 

The  e^Dosure  to  the  air  is  necesLry  Lc^uL  Z^ 

oxidised,  assume  a  deeper  colol^rindZZ.LTr^'''^''^!^  "^'^^ers  become  more 
brown  solution  of  the  acetate  of  Hmpio^  ^"^^  ?":  combination  with  lime.  The 
precipitate,  and  heated  to  £  Ll  Xnl^U  ""^!r'^  ?  "  «"'*«*>^«  »»«"°«'*  ^o^  the 
W  are  successively  addS  rion^asThe  l^uTi  'n^^  "  clear  solution  of  chloride  of 
evaporatmg  to  dryness,  the  yellowTsh  Jav  S.  i!"f '  to  become  paler.  After 
with  a  smaU  proportion  of  chloridrnf  ii  -^  ^  ^  '  ^^'''^'  """^^'^^^  «^  "^etate  of  lime 
acetate  be  intenrd  to  be  obtS  bv  d1  t  nTr  "  t^^^r^^  by  sulphuric  acid.  If^e 
must  be  diluted  with  an  equalvoTumLf  wat^^^^  ^'""^  ''^"  °"'^*"^«'  *^«  ^^^P^^""^  «<^id 
-^ff^t^^^^^^^^^  or  only  very  slightly  so,  and 

«  left  standing  for  a  short  tim^e  U  Tthen  to Z  H  1^  I  a  ^"^f^^mn  of  heat.  Themixture 
drawn  off  from  the  gypsum.  li  this  case  U  is  nf  L^^  •  with  water,  and  the  clear  water 
phunc  ac  d  with  water  «<,  ♦».«  r!t         ^  "**'  advisable  to  prev  ously  dilute  the  mil 

with  difficulty,  an7l:;\:Lf  mKu'd*''"  "^""^^  ^  crystallioe^oose  J,ditLt  subsfdi 

-id";  an5,rtL*treTt:'at"rfr„^^         ^"r*^*y  "^  «"--*'«  -•<^'  -^-  -Ip^nrous 
added  and  heat  applied "KtiVr'acto  7  ^^^^«  "^^^^  '^^  »-  toZ 

acid  from  the  gypsum  and  also  «,  lr^w    Ti    !i       f*  ..      Precipitate  retains  sulphurous 
acetate  of  leafylld^a^owi  A^^^  and  chlori/e  of  lead.    The  solutio?  of  tS 

Jead  but  which  is  gener^^fy  s^lXnurl  for'  5^"*^"""^  ^  «"^^»  Po^tion  of  chforide  of 
purified  by  recrystallization  ^  ^  '^  ^^^^  *^^^'"^  purposes,  and  can  be  still  further 

I  Zf ?e^IK^  t^fp'r^^^^^^^^^  ba>  been  said  under  Ac...  Ac. 

Manchester.     The  retortHnf  ca^ imn  1^fp?t""i  *  ^''Vl^l'  «^  «"  establishment  ne^ 
Two  of  these  cylinders  are  h^a^LlTy  re  h.VthVfl^^^^^^  1  ^"^^^  ^"  ^'-"^^e^ 

and  upper  surface;  but  the  bottom  is  shield^  bv  firp  ,1  7""^  H^^'l^  '"""^  their sid^w 
fire.  2  cwts.  of  coals  are  suffickSt  o  crmnlet^thpr  n  ?'''"  V^'  ^^""^^^  «^»'on  o*'  <br 
36  imperial  gallons  of  crude  vinegar  of  rc^c^mvjfv  1  nof  "J^  ^"^  '^'^^"^  «^  ^^^^  J 
retort.     The  process  occupies  24 "ours      tI  ?7  \^  1-025  being  obtained  from  each 

^nited  charcoal  is  raked  out  7orexS;n^^„r^^^^^  If  '?""  ™oved,  and  the 

edges,  into  which  a  lid  is  fitted     ^''^"'''**^''  '"*«  *"  "o»  ^best,  having  a  groove  round  iu 

^^^^^S^^"^:^^  distDled,  it  yields  one  ^ 

successive  distillations  with  quicklime         "^P'^">'    ^^^^^^^  is  rectified  by  two  or  tnfee 

Ji?;a^rJsarut%°,^^^^^^^  -bjeeted  to  distillation  b, 

quicklime,  and  subsequent  a/itationwitlwa^er^  ^"  ^"'''^"^  ^^  re-distillation  with 

whTch%ra'r;^f.pt%^^rtt*:i!!^h%^^^^^^     -'^  -  '^  ^-^--pper, 

up  with  the  heat.  Vhe  fluidXound  ttt  pt^:^^^^^^^^  'j'^f  --' -  ^^  iVoths* 

and  mixed  with  a  quantity  of  alum  equivalenfto  its  siSn^pr^  f^""  *"5^'***''  ^^^P*''* 
liquor,  or  acetate  of  alumina,  of  the  cali^nrintPr  tII^I*''  '"  ^'!^^''  *°  ^°™  tbe  red 
alumina  and  potash,  mutually  decomno  ^rch  o.h^r        ^k^^^^^  '""^VhRte  of 

lime,  M'hich  falls  immediately  to  'heTttom  '   ^^^  *^^  formation  of  sulphate  of 

M.  Kestner,  of  Thann,  in  Alsace,  obtain's,  in  his  manufactory  of  pyroligneous  acid,  6 


PYROLIGNOUS    ACID. 


521 


hectolitres  (112  gallons  imperial,  nearly)  from  a  cord  containing  93  cnbic  feet  of  wood. 
The  acid  is  very  brown,  much  loaded  w^ith  tar,  and  marks  5°  Baume  ;  220  kilogrammes 
of  charcoal  are  left  in  the  cylinders ;  600  litres  of  that  brown  acid  produce,  after  several 
distillations,  375  of  the  pyroligneous  acid  of  commerce,  containing  7  per  cent,  of  acid, 
with  a  residuum  of  40  kilogrammes  of  pilch.  For  the  purpose  of  making  a  crude  acetate 
of  lead  (pyrolignile)  he  dries  pyrol ignite  cf  lime  upon  iron  plates,  mixes  it  with  the 
equivalentdecomposingquantity  of  sulphuric  acid,  previously  diluted  with  its  own  weight 
of  water,  and  cooled  ;  and  transfers  the  mixture  as  quickly  as  possible  into  a  cast-iron 
cylindric  still,  built  horizontally  in  a  furnace ;  the  under  half  of  the  moulh  of  the  cylinder 
being  always  cast  with  a  semicircle  of  iron.  The  acetic  acid  is  received  into  large  salt- 
glazed  stone  bottles.  From  100  parts  of  acetate  of  lime,  he  obtains  133  of  acetic  acid,  ai 
38^  Baume.  It  contains  always  a  little  sulphurous  acid  from  the  reaction  of  the  tar  and 
the  sulphuric  acid. 

The  apparatus  represented  in/g*.  11 96  and  1197  is  a  convenient  modification  of  thai 
exhibited  under  acetic  acid,  for  producing  pyroligneous  acid.   ii%.  1196  shows  the  fur 


nace  in  a  horizontal  section  drawn  through  the  middle  of  the  flue  which  leads  to  the 
chimney.  Fiff.  1197.  is  a  vertical  section  taken  in  the  dotted  line  x,  x,  of /^.  1196.  The 
chest  a  is  constructed  with  cast-iron  plates  bolted  together,  and  has  a  capacity  of  100 
cubic  feet.  The  wo(k1  is  introduced  into  it  through  the  opening  6,  in  the  cover,  for 
which  purpose  it  is  cleft  into  billets  of  moderate  length.  The  chest  is  heated  from 
the  subjacent  grate  c,  upon  which  the  fuel  is  laid,  through  the  fire-door  d.  The  flame 
ascends  spirally  through  the  flues  e,  e,  round  the  chest,  which  terminates  in  tlie  chimney/. 
An  iron  pipe  ^r  conveys  the  vapours  and  gaseous  products  from  the  iron  chest  to  the  con- 
denser. This  consists  of  a  series  of  pipes  laid  zigzag  over  each  other,  M'hich  rest 
upon  a  framework  of  wood.  The  condensing  tubes  are  enclosed  in  larger  pipes  f.  t;  a 
stream  of  cold  water  being  caused  to  circulate  in  the  interstitial  spaces  between  them. 
The  water  passes  down  from  a  trough  k,  through  a  conducting  tube  /,  enters  the  lowest 
cylindrical  case  at  m,  flows  thence  along  the  series  of  jackets  «,  t,  i,  being  transmitted 
from  the  one  row  to  the  next  above  it,  by  the  junction  tubes  o,  o,  o,  till  at  p  it 
runs  ofl"  in  a  boiling-hot  state.  Tlie  vapours  proceeding  downwards  in  an  opposite  direc- 
tion to  the  cooling  stream  of  water,  get  condensed  into  the  liquid  state,  and  pass  off  at  y, 
through  a  discharge  pipe,  into  the  first  close  receiver  r,  while  the  combustible  gases  flow 
off  through  the  tube  «,  which  is  provided  with  a  stop  ci^k  to  regulate  the  magnitude  of 
their  flame  under  the  chest.  As  8o<m  aa  the  distillation  is  fully  .set  agoing,  the  stop  cock 
upon  the  gas  pipe  is  opened ;  and  after  it  is  finished,  it  must  be  shut.  The  fire  slunild  be. 
supplied  with  fuel  at  first,  but  after  some  time  the  gas  generated  keeps  up  the  distilling 
heat  The  charcoal  is  allowed  to  cool  during  6  or  6  hours,  and  is  then  taken  out 
through  an  aperture  in  the  back  of  the  chest,  which  corresponds  to  the  opening  «,  ^.j 


t 


622 


PYROLIGNOUS  ACIDS. 


1196.,  in  the  brickwork  of  the  furnace.  About  60  per  cent,  of  charcoal  may  be  obtained 
from  100  feet  of  fir-wood,  with  a  consumption  of  as  much  brush- wood  for  fuel. 

Stoltze  has  ascertained,  by  numerous  experiments,  that  one  pound  of  wood  yields  from 
6  to  7i  ounces  of  liquid  products;  but  in  acetic  acid  it  affords  a  quantity  varying  from  2 
to  5,  according  to  the  nature  of  the  wood.  Hard  timber,  which  has  grown  slowly  upon 
a  dry  soil,  gives  the  strongest  vinegar.  White  birch  and  red  beech  afibrd  per  pound  7i 
ounces  of  wood  vinegar,  1^  ounce  of  combustible  oil,  and  4  ounces  of  charcoal.  One 
ounce  of  that  vinegar  saturates  110  grains  of  carbonate  of  potassa.  Red  pine  yields  per 
pound  6^  ounces  of  vinegar,  2^  ounces  of  oil,  Sf  ounces  of  charcoal;  but  one  ounce  of 
the  vinegar  saturates  only  44  grains  of  carbonate  of  potassa,  and  has  therefore  only  two- 
fifths  of  the  strength  of  the  vinegar  from  the  birch.  An  ounce  of  the  vinegar  from  the 
white  beech,  hollv  oak  (Jlez),  common  ash,  and  horse  chesnut,  saturates  from  90  to  100 
grains  of  the  carbonate.  In  the  same  circumstances,  an  ounce  of  the  vinegar  of  the 
alder  and  white  pine  saturates  from  58  to  60  grains. 

At  Cornbrook  works,  near  Manchester,  cast-iron  cylinders  of  6  feet  by  3  feet  are 
employed,  with  square  doors,  on  hinges,  placed  in  the  centre  of  the  front  of  each  cylinder. 
6  tons  of  wood  are  carbonized  by  means  of  H  ton  of  coal.  24  hours  are  allowed  for 
the  process  of  carbonization.    The  cylinders  are  heated  by  one  fire. 

The  Risca  and  Abercam  works,  both  in  Monmouthshire,  and  belonging  to  one  pro- 
prietor, form  conjointly  the  largest  works  of  the  kind  in  this  country.  At  Risca,  cast- 
iron  cylinders,  6  feet  by  4  feet,  holding  about  f  of  a  cord  of  wood  each,  are  employed, 
as,  also,  wrought  iron  chests,  with  an  iron  pipe,  of  6  inches  diameter,  passing  through 
to  convey  the  heat  to  the  interior  of  the  chest,  each  of  which  is  capable  of  holding  14- 
cord  of  wood.  ^  ^    * 

At  Abercam,  8  square  ovens,  with  boxes,  are  used,  each  oven  being  capable  of  con- 
taining 1  cord  of  wood.  Twenty-four  hours  is  usually  allowed  for  carbonization ;  but 
a  charge  can  be  worked  off  in  from  twelve  to  sixteen  hours,  if  required.  At  Chester 
works,  large  cylinders  are  employed,  also  a  large  square  oven  like  that  at  Risca.  The 
heated  cast-iron  pipe  passing  through  the  interior  of  the  dense  mass  of  wood  very  much 
assists  its  carbonization.  At  Lougher,  near  Swansea,  and  also  at  Deptford,  the  following 
form  of  carbonizing  apparatus  is  adopted : — a  large  circular  sheet  iron  vessel  is  set  in 
brickwork,  having  an  aperture  of  particular  shape  and  size  in  the  top;  within  this 
carbonizer,  the  sheet  iron  vessels  containing  the  wood  are  placed.  These  are  of  such  a 
shape,  that  6  of  them,  each  2  feet  wide  at  one  part,  and  4  feet  deep,  form,  when  put 
together,  a  shape  corresponding  with  that  of  the  carbonizing  vessel  iu  which  they  are 
contained.  As  there  is  but  one  aperture  in  the  carbonizer  through  which  to  introduce  the 
six  inner  vessels  containing  the  wood,  a  moveable  framework  is  placed  at  the  bottom  of 
the  carbonizer,  by  means  of  which  each  of  the  receptacles  for  the  inner  vessels  are  in  turn 
brought  under  the  aperture  in  the  top  of  the  cylinder,  and  receive  the  casing  of  wood 
destined  for  them.  The  aperture  is  then  closed  with  a  sheet  iron  lid,  and  luted  in  the 
ordinary  manner. 

The  liquid  products  of  the  distillation  of  wood  may  be  comprised  under  the  heads  of 
acid,  spirituous,  tarry,  and  oleaginous ;  the  gaseous  products  are  carbonic  acid,  olefiant 
gas,  and  light  carburetted  hydrogen.  The  relative  proportions  of  charcoal,  and  of  liquid 
and  gaseous  products  depend  on  the  nature  and  quality  of  the  wood  employed,  and  the 
regulation  of  the  temperature.  Stoltze  is  quite  right  in  his  statement  that  the  strongest 
acid  IS  obtained  from  firm  woods,  of  slow  growth,  in  a  dry  soil ;  then  those  in  moist 
grounds ;  and  lastly,  the  weakest  from  pines  and  resinous  trees,  the  product  from  these 
being  much  inferior  to  all  the  others. 

To  effect  the  carbonization  of  sawdust,  spent  bark,  and  other  refuse  materials,  two 
processes  have  been  recommended ;  the  one  that  of  Mr.  A.  P.  Halliday,  of  Manchester, 
whose  process  is  as  follows.  The  raw  material  is  introduced  into  a  hoppr,  whence  it  is 
fed  through  a  pipe  by  means  of  a  screw  revolving  in  the  said  pipe  to  the  retort,  which 
has  also  a  screw  of  about  the  same  diameter  as  the  inside  of  the  retort ;  a  revolving 
motion  to  which  being  given,  the  material  is  passed  gradually,  in  an  agitated  state,  through 
the  heated  retort.  At  the  extreme  end  of  the  retort  two  pipes  branch  off,  one  passing 
downwards  and  dipping  into  a  vessel  or  cistern  of  water  into  which  the  carbonized 
substance  falls ;  the  other  pipe  passes  upwards,  for  the  conveyance  of  the  gases  given  off 
during  the  destructive  distillation  of  the  material,  through  a  main  conduit  pipe  to  the 
condenser,  which  may  be  constructed  according  to  any  of  the  approved  modes  now 


in  use. 


The  other  process  is  that  patented  by  Messrs.  Solomons  and  Azulay,  which  consists  in 
passing  super-heated  steam  into  the  mass,  whereby  the  heating  agent  comes  into  actual 
contact  with  every  particle  of  the  vegetable  mass,  and  effectually  carbonizes  it  A 
charcoal  well  adapted  for  artificial  manures  is  thus  obtained,  as  well  as  the  ordinary 
products  of  the  distillation  of  wood,  which  pass  off  with  the  steam.    It  may  be  urged 


PYROLIGNOUS  ACID. 


533 


that  the  quantity  of  steam  required  for  carbonization  in  passing  off  with  the  products  of 
distillation,  dilute  them  to  such  a  degree  as  greatly  to  increase  the  quantity  of  fuel 
requisite  for  the  evaporation  of  the  acetate  of  lime  or  other  acetate  to  be  formed  with  it ; 
this,  however,  is  obviated  by  making  the  steam  and  heated  vapours  from  the  cylinder 
traverse  a  coil  of  pipe  immersed  in  the  solution  to  be  evaporated,  or  pass  through  stills 
containing  liquid  to  be  distilled ;  all  danger  of  the  pipes  being  clogged  up  with  tarry 
matter,  as  in  the  exit  pipes  of  ordinary  cylinders,  being  prevented  by  the  passing  of  the 
steam. 

Part  II. — Separation  of  the  liqtcid  products  of  distillation  from  each  other.  The  con- 
densed liquid  products  before  described  form,  by  subsidence  in  the  tank  or  receptacle, 
two  layers,  the  lower  composed  of  tarry  and  oily  matters,  and  the  upper  containing  the 
acid  and  spirituous  parts  of  the  products.  If  two  tanks  be  provided,  the  one  at  a  lower 
level  than  the  other,  the  acid  and  spirituous  liquor  passes  by  means  of  an  overflow  pipe 
into  the  lower  tank,  and  thus  becomes  separated  from  the  tar  ;  and  if  the  acid  liquor,  in 
passing  from  one  tank  to  the  other,  be  made  to  traverse  a  suitable  filter,  a  large  portion 
of  the  tarry  and  oily  matters  held  mechanically  in  suspension  by  the  acid  liquor  will  be 
returned. 

The  next  process  depends  upon  the  method  of  working  adopted  at  each  particular 
manufactory,  but  without  individual  reference  we  may  class  them  all  under  two  heads. 
First,  those  who  distil    the    pyroxylic  spirit  direct  from  the  crude  acid  liquors;  and, 
secondly,  those  who  first  neutralize  the  acid  liquors  with  lime  and  then  distil  off  the 
spirit.     The  first  class  employ  copper  stills  of  a  capacity  of  about  500  gallons ;   into 
these  the  crude  acid  liquor  is  pumped,  and  heat  applied  either  by  means  of  steam  made 
to  traverse  a  coil  of  well-connected  copper  pipes  placed  within  the  still,  as  at  Pitchcombe 
"Works,  or  the  stills  are  heated  externally,  as  at  Cwm  Avon  Works.     In  the  second  case 
sheet-iron  stills  or  boilers  are  employed,  and  the  previously  neutralized  acid  liquor  run 
into  them,  and  external  heat  applied,  as  at  the  Melancrythan  and  other  works.     In  each 
case  about  100  gallons,  or  ^  of  the  contents  of  the  still,  are  distilled  off  and  put  by  as 
containing  all  the  pyroxylic  spirit,  the  further  distillation  and  purification  of  which  we 
shall  hereafter  speak  of.     In  the  first  case  the  remaining  acid  is  next  distilled  off,  and  the 
residuary  tarry  liquor  run  off  through  a  cock  placed  in  the  lower  part  of  the  still,  or  if 
distilled  acid  be  not  required,  the  remaining  400  gallons  are  run  off  into  a  suitable  tank 
or  reservoir,  in  which  the  tar  settles  to  the  bottom,  and  the  acid  liquor  may  be  drawn 
off  or  pumped  up  for  further  use.     In    the  second  case  the  remaining  400  gallons  of 
neutralized  acid  liquor,  or  acetate  of  lime  solution,  is  run  out  of  the  still,  and  employed 
as  will  be  hereafter  described. 

The  tarry  product  of  the  distillation  of  wood  is  also  distilled  in  copper  or  cast-iroa 
stills,  and  the  crude  spirit  obtained  therefrom  is  added  to  that  obtained  from  the  dis- 
tillation of  the  acid  liquor  above  mentioned. 

Part  III. — Manufacture  of  pyroxylic  spirit  or  wood  naphtha.  The  crude  and  weak 
spirit,  procured  in  the  distillation  before  mentioned,  is  next  subjected  to  repeated 
distillations  in  order  to  obtain  the  spirit  in  a  more  concentrated  form,  which  is  then 
rectified  by  distillation,  first  with  lime  alone,  and  lastly  with  a  mixture  of  lime  and 
caustic  potash.  In  some  works  chalk  is  employed,  and  in  others  lime  and  bicarbonate 
of  soda.  For  this  purpose  copper  stills  are  employed,  and  steam  heat  applied,  either 
through  a  coil  of  lead  pipe  placed  within  the  still,  or  to  the  outside  of  the  still,  the 
lower  half  of  which  has  been  previously  cased  in  an  iron  jacket.  The  pyroxylic  spirit 
thus  obtained  is  perfectly  colourless,  and  is  to  be  met  with  in  the  market  of  sp.  grav. 
varying  from  0-870  to  0-8320. 

The  quantity  as  well  as  quality  of  the  pyroxylic  spirit  obtained  at  one  .works  often 
differs  much  from  that  obtained  at  another  works ;  the  kind  of  wood  has  something  to 
do  with  this,  but  management  of  the  process  much  more.  The  quantity  varies  from  1^ 
gallons  to  2\  or  even  3  gallons  per  ton  of  wood  employed. 

The  following  table  was  constructed  by  Dr.  lire,  with  the  view  of  showing  the  percentage 
of  real  spirit  in  pyroxylic  spirit  of  different  specific  gravities.  The  wood  spirit  employed 
in  the  construction  of  this  table  was  purified  by  distillation  over  powdered  quicklime, 
and  was  drawn  over  with  the  heat  of  a  water  bath  at  such  a  temperature  that  its  sp. 
grav.  was  0-8136  at  a  temperature  of  60*^  Fahr. 

Mr.  Scanlan,  in  the  Proceedings  of  the  British  Association,  1835,  gives  -828  as  the 
specific  gravity,  and  150°  as  the  boiling  point.  "  Wood  spirit  of  0*870  specific  gravity," 
says  Dr.  Ure,  "  boils  at  144°  F.,  and  if  it  be  brought  by  distillation  to  spec.  grav.  0  832, 
it  boils  at  140°  F."  The  commercial  wood  spirit  varies  very  much,  both  as  to  its  spec 
grav.  and  its  power  of  dissolving  gum  sandarach,  shellac,  <fec.,  from  its  containing  acetone, 
anesite,  Ac,  in  variable  proportions.  The  presence  of  these  bodies  is  to  be  accounted 
for  by  variation  in  the  modes  employed  for  obtaining  and  purifying  the  wood  spiriti 
as  also  by  the  more  or  less  careful  management  of  the  several  processes  it  is  made  to 
undergo.    The  question  then  natiu-ally  arises,  how  are  we  to  judge  of  the  quality  of 


634 


PYROLIGNOUS  ACID. 


Specific 
Gravity. 


Beal  Spirit 
percent 


Over  Excise 
proof 


•8136 

10000 

•8216 

98-00 

•8256 

9611 

•8320 

94-34 

•8384 

92-22 

•8418 

90-90 

•8470 

89-30 

•8514 

87-72 

•8564 

86-20 

•8696 

84-76 

•8642 

83-33 

•8674 

82-00 

•8712 

80-64 

•8742 

79-36 

•8784 

78-13 

•8820 

77-00 

•8842 

76-76 

•8876 

7463 

•6918 

73-53 

•8930 

72-46 

•8960 

71-43 

•8984 

70-42 

•9008 

69-44 

64-10 

6110 

58-00 

65-60 

62-60 

49-70 

47-40 

44-60 

42-20 

39-90 

37-10 

85-00 

32-70 

8000 

27-90 

26-00 

24-30 

22-20 

20-60 

18-30 

16-30 

15-30 


Specific 
Gravity. 


•9032 
•9060 
•9070 
•9116 
•9164 
•9184 

•9218 

•9242 

•9266 

•9296 

•9344 

•9386 

•9414 

•9448 

•9484 

•9518 

•9540 

•9664 

•9584 

•9600 

•9620 


Beal  Spirit 
per  cent. 


Orer  or  under* 

IKTOOf. 


wood  spirit  ?  will  a  knowledge  of  its  snpp  o-ra^  «,.  «<^  •*    u    i- 

respect  I    If  a  wood  spirit  £  requleT  fof  bu;!^       ^'^'-^  V^  ^"'^^  "'  '°  ^^a 
horses,  there  can  be  no  doubt  bu?  that  thp  «n^rT/  f  *k"  ?  "?"'**  ^"^P'  «^  ^^^  «i"geing 
but  if  the  wood   spirit  T  requ  r^  for  th?  m.nf,f-  ^?  ^^"^"/^  '^^:  8^^'  ^  ^^^  ^««'1 
especially  those  containing  ffumlandarach     L  fv.    ^"^'"""^  ""^  varnishes  and  polishes 
instance/a  sample  of  wc^^spTrircon  ^^^^^^^  per'J^nrhJlt""  7'''  "'^-^  ^^5^    ^- 

of  another  sample  containing  95  per  cent  wJ^ln^  •'  ^^^^^  Z^''  P^^^erred  to  that 
spirit  obtained  by  limine,  the  cruJp Lvfl;  f  ^^^  invariably  found  that  the  wood 
n^t  dissolve  -ndfrach"  whiUt%raf o^fc  ^"^^^^  ^-tillation  d^^ 

crude  liquor  before  limine-  is  a  o-nnri  sni^o^r^y  aistUling  off  the  spirituous  portion  of  the 

.f  »  low^pe.  grav..  ^^il'^brwi^"  wafer 'wtut^e'  {aLTc  /■'•*''1  f '  ""^  ""'"S 
and  was  rendered  milky  on  the  addition  of  ^^6*  «>ntamed  les.  real  spiri? 

w^kin-rorLtr.r.I'oVoTn^'^^^^^^  "t'-"'  -  ^e  «verag. 

tons  of  wood  has  only  yielded  Ifin  3i^J!   r  another  a  weekly  consumption  of  80 

gallons  have  been  obt'Li^'from  36  f^s  of  woS""^'''  ''^'"^ '  *"^  ''  *  '""'^'^  ^^^^  '^ 
^^^^elj;7.^:-^^^^^^  acetate  of  lime  is  of  two 

saturating  with  lirae  eithe?  th^  dis^illpd  nnl^  w  '"^  ^^^ '  *^^««  ^'^  obtained  by 
after  pyrSxylic  spirit  hTb^en  remoy^  by  S^^  mentioned,  or  the  undistilled  aciS 

almost  to  dryness^^or  by  eyrporatT^Tl^,nf„f  "'^     "l  ?**  ^T^porating  the  clear  solution 

in  the  case  in  which  tl^  crEc  S\as  Wn  n^^^  •  u^'/^"  ^''•""  ^^  ^^«"^  *^«  ''^^ 

lation  of  the  spirituous  product  TT^i,  Z  "^"*^^^^^f  ^1*^  lime  previous  to  the  distil- 
distillation.  or  ?he  disUll^d  acid,  or^e  unSllTdldd'  .^^^*^^?"d-  -<^^^  Previous  to 
the  same  manner.  The  add  linnnr  ;«  L  i  •  !  *^*^'  *^  *"  ^^^^^'  case  performed  in 
capacity  say  from  5oS  to  Too^ga^L^^^  or  iron  yessels  o7conven1eit 

of  skked  and  sifted  lime,  previous ly  ma^^^^  ""^  ^'^^^'  powdered  chalk  or 

added  until  the  blue  ™  W  of  S,f  1^^  '""^^  the  consistence  of  cream  with  water  is 
lime  is  then  added.  ^Jita  ^few  To  reXthe°'J"°!'  reddened ;  a  slight  excess  of 
complete.     A  portion  of  the  tarry  mattolfr  ?«P«fation  of  the  oily  matters   more 

of  tCe  chalk  ?r  lime  empW^^^^^^  *"  *^  ^'^^  ^ith  the  impuriti^ 

floats  CHI  the  surface,  and  Vremryed^byskim^^^^^^^^^  ^^«  ^•'"e. 

when  clear,  is  ready  for  the  evaporating  nn^o      ?•  u         ^^^^^^n  of  acetate  of  lime. 

with  lead,  and  furnished  whh  coUg  oJ^I  P^m^^'"^  ?'^  ^'^^^'  ^«°<^«"  ^^«-^«l«  lined 
boiler,  or  shallow  pans  of  sheet  iron  Jt  "5  ^ron  steani-pipes  in  connexion  with  a 
repeatedly  skimmej^  to  remrve  he  terry  matL^floTr''^  ^'T'^''  *^"'"^  ^^^^'^n  '*« 
as  fixst  as  formed,  is  fished  out  by  Ss  of  W.  !?-°^  ''^  ^"  ^^''^^^^ '  '^^'^  ^^'^  ««!*. 
Uskets  suspended  oyer  the  pans/so  th:?^  ^^  ^^1^^  t^ Jt  L^  Z^^ 


PYROLIGNOUS  ACID. 


525 


allowed  to  cool.  The  following  practical  result  was  obtained  by  the  use  of  three  sheet 
iron  pans  about  18  inches  in  depth,  and  capable  of  containing  450  gallons  of  acetate  of 
lime  liquor  each.  First  six  days  of  24  hours  each,  7020  gallons  of  liquor  were  evapo- 
rated,  producing  78  cwt.  of  diy  acetate  of  lime.  Second  week,  8060  gallons  were 
evaporated,  producing  92  cwt.  of  dry  acetate.  Third  week,  7000  gallons  were  evaporated, 
producing  78  cwt.  of  dry  acetate  of  lime.  Two  of  the  pans  contained  brown  acetate  of 
lime  liquor,  and  the  other  grey  acetate  liquor. 

Tlie  next  part  of  the  process  is  the  drying  of  the  drained  acetate  of  lime.  Tliis  is 
usually  effected  by  placing  it  on  the  top  of  the  mass  of  brickwork  in  which  the  retorts,  or 
cylinders,  or  ovens,  are  set ;  but  as  there  is  seldom  room  to  dry  the  whole  of  the  salt  in 
this  way,  many  works  are  furnished  with  a  drying  house  in  addition,  and,  where  the 
lime  is  made  on  the  spot,  the  waste  heat  from  the  kiln  or  furnace  is  made  available  for 
drying  the  acetate,  it  being  made  to  traverse  the  flues  beneath  the  floor  of  the  drying 
house.  As  a  general  rule,  however,  the  drying  of  the  acetate  of  lime  is  a  part  of  the 
processes  of  this  manufacture  by  no  means  well  executed,  requiring  as  it  does  more 
attention  than  the  workmen  are  usually  disposed  to  give  to  it. 

Turf  forms  the  best  material  for  fuel,  as  it  does  not  burn  rapidly,  and  produces  a 
steady  and  equal  temperature. 

Drying  of  the  acetate  of  lime.  When  the  furnace  is  thoroughly  and  equally  heated, 
the  flame  of  the  fire  is  allowed  to  subside.  If  wood  is  employed  as  fuel,  the  sliding  door 
should  be  opened  at  the  commencement  in  order  to  allow  the  moisture  to  escape.  The 
salt  is  transferred  from  the  evaporating  vessels  to  the  drying  plate,  and  spread  out  to 
the  depth  of  2  inches ;  and  after  the  first  portion  has  become  somewhat  dry,  the  depth 
is  increased  to  4  or  5  inches ;  the  heat  is  preserved  at  the  degree  already  mentioned  for 
24  hours,  and  during  this  time  the  salt  is  turned  several  times ;  subsequently  when  the 
mass  appears  to  be  becoming  dry,  the  temperature  may  be  increased  to  100°  (257°  R), 
so  as  to  dry  it  completely.  The  mass  is  dry  and  properly  roasted  when  it  possesses  the 
following  characters.  It  must,  before  cooling,  be  brittle,  easily  crumbled  between  the 
fingers,  mixed  with  blackish  carbonaceous  points  or  streaks,  between  which  appear 
pieces  of  dry  salt.  A  solution  of  the  comminuted  salt,  in  4  or  6  times  its  volunae  of  hot 
water,  possesses  a  yellowish  brown  colour  with  a  dark  tinge,  while  previously  it  had  a 
reddish  brown  colour.  When  the  heat  is  increased  towards  the  end  of  the  process,  as 
described,  care  must  be  taken  to  do  it  gradually,  so  that  no  smoke  shall  rise  from  the 
acetate,  because  it  might  thus  be  decomposed.  Neither  must  any  spark  be  permitted 
to  come  in  contact  with  the  acetate  of  lime  ;  because,  like  sugar  of  lead,  it  possesses  the 
property,  in  these  circumstances,  of  catching  fire  and  burning — by  which  the  whole  dry 
preparation  would  be  completely  destroyed.  The  treatment  of  the  acetate  of  lime  in 
this  manner,  by  means  of  gradual  drying,  as  experience  has  shown,  possesses  many 
advantages  over  the  method  of  drying  the  salt  in  an  open  vessel ;  because  there  is  no 
loss  of  acetic  acid,  as  always  occurs  by  the  latter  process.  The  operator  has  the  prepa- 
ration C4)mpletely  in  his  power,  and  with  little  expense  of  fuel  and  time,  many  hundred- 
weights of  the  salt  can  be  prepared  at  once.  This  process  does  not  merely  extend  to 
the  removal  of  the  moisture  from  the  acetate  of  lime,  out  a  chemical  influence  is  exerted 
by  means  of  it ;  because  it  is  certain  that  the  substances  formed  by  dry  distillation, 
which  have  been  recently  distinguished  by  Reichenbach,  are  partly  dissipated  by  the 
heat,  and  partly  decomposed,  the  acetate  of  lime  possessing  very  different  properties 
before  and  after  the  process.  After  the  process,  the  salt  does  not  imbibe  water  so  readily 
as  it  did  previously.  After  solution,  filtration,  and  evaporation,  a  much  purer  product 
is  obtained  than  liefore,  and  upon  the  filter  a  resinous  matter  remains,  the  constituents 
of  which  have  not  yet  been  examined. 

Part  V. — Manufacture  of  Pyro-acetic  spirit ^  or  acetone.  The  usual  mode  of  obtaining 
pyro-acetic  spirit  is  by  the  decomposition  of  the  acetates  by  means  of  heat.  For  this 
purpose  the  acetate  is  submitted  to  dry  distillation  in  a  retort,  great  attention  being  paid 
to  the  temperature,  which  should  be  kept  as  low  as  possible,  consistent  with  the  decom- 
position of  the  acetate  employed.  The  distillation  should  be  conducted  with  a  slowly 
mcreasing  heat,  as  the  quicker  the  temperature  is  raised,  the  larger  is  vhe  quantity  of 
pyro-acetic  spirit  destroyed ;  carbon  remains  in  the  retort*  and  the  empyreumatic  oil 
formed  renders  the  spirit  impure.  In  the  case  of  the  metallic  acetates,  water,  acetic 
acid,  and  pyro-acetic  spirit,  pass  off  in  a  state  of  vapour,  and  are  condensed ;  carbonic 
acid  and  carburetted  hydrc^en  gases  are  the  incondensable  products,  whilst  the  metallic 
base,  mixed  with  some  carbonaceous  matter,  remains  in  the  retort.  The  metallic  base  is 
usually  reduced  to  the  metallic  state,  and  the  more  difficult  this  reduction  is,  the  greater 
ia  the  quantity  of  pyro-acetic  spirit  formed. 

Acetates,  tne  bases  of  which  contain  carbonic  acid  at  a  red  heat,  produce,  when  heated 
in  close  vessels,  the  carbonate  of  the  base  and  acetone.  This  takes  place,  for  example, 
with  the  acetates  of  potassa,  soda,  and  baryta.  Where  the  oxide  cannot  retain  carbonic 
acid  at  a  red  heat,  as  in  the  case  of  acetates  of  magnesia,  zinc,  or  manganese,  tb« 


phi 


hf 


I    ! 


mi 


526 


PYROLIGNOUS  ACID. 


acetate  is  accompanied  by  carbonic  acid.    If  the  oxide  be  easily  reducible  as  in  the  acetatei 
of  copper,  silver  and  mercury,  there  are  given  oflF  hydrated^acetlacTd  carbonic  o^^^ 

acetates.    The  following  extract  shows  the  quantity  of  pyro-acetic  sp^it  oltl^ned 


Acetate  of  silver 
da 
do. 
do. 


copper 
nickel 


do. 
do. 
da 


iron 
lead 
zinc 
manganese 


0-00 
Oil 
020 
0-24 
0-55 
0-69 
0-94 


proportion  of  pyro- 


-.^  ^  -f  fr  P°^^^  f"^^  ^'""^'  ^"^  ^"3^**  y^^^d  a  n^uch  larger  proportion  ot  pvro. 
acetic  spirit  than  any  of  the  metallic  acetates,  and  are  therefore  generally  cmpWerf^ 
this  purpose  more  especially  the  acetate  of  lime.  It  would  appear  that^the  acet^ates  of 
silver  and  of  baryta  stand  at  the  two  extreme  points  of  the  list^f  acetates  in  rl^t^o 
the  production  of  pyro-acetic  spirit ;  the  former  yielding  only  a  concentrated  a.^t^acd 
with  not  a  trace  of  spirit,  wtiilst  the  latter  yields  a  liquid  product  a  most  ertird^ 
spirituous,  with  scarcely  a  trace  of  acid.    The  acetate  of  copper  also  yields  but  a  smaft 

Dumas  submitted  to  dry  distiUation  100  parts  of  acetate  of  baryta,  composed  of 


Baryta 
Acetic  acid 
Water 


560 
37-4    ' 
6-6 

1000 

The  result  of 


and  capable,  therefore,  of  yielding  215  per  cent,  of  pyro-acetic  spirit 
several  experiments  gave  the  following  products :—  ^ 

Carbonate  of  baryta  -  -  .  . 

Charcoal  -----  T 

Pyro-acetic  spirit  -  ...  * 

Water  -  -  ...  I 

Gas  and  loss  -  -  -  .  " 


1000 

T.«S"nf'r"P^''*''"!**'**.*^°  P^'^°^^  o^*^^  ^^^^'•^o^^  "o«e  from  the  decomposition  of  a 
C  „^J  Pyro-acet.c  spirit,  tfi ere  would  be  about  two  per  cent,  of  spirit  t7l^added  tS 
1 8  np^.'  7  '^  ^^W  g've  near  about  the  theoretical  quantity.  Taking  the  product  at 
18  per  cent   one  cwt  of  acetate  of  baryta  should  furni8h^2i  gallons  of  pfro  aS  sd  rft 

2..  Z  u  '\T-^  ^ft""'  •'  ^^^^'"^^  fro^  *^«  o^d'"«»-y  «««tate  of  lime  Jrcommerce^nd 
the  results  obtained  by  operating  on  some  tons  of  this  salt  did  not  give  evSX  amount 
of  produce,  no  doubt  on  account  of  sufficient  attention  not  havinXen  Jiven    o  the  due 

successive  distillat  ons  over  quick  lime,  when  a  limpid  colourlerfluid  Ca  t-a^  0  ?92^^ 
^^poduced.      It  IS  «,luble  in  water,   alcohol,   a'nd   ethe.,  and' bl?  wi^l':  tS 

or  IVoUnn^ifT^  ""^^^fZ^A'  "^  r''^'    ^''?«/«<^'«'-''  of  the  brou,n  acetate  of  leaa 

'•un  in  UDon  it  whilst  hnilino-   fi^f  l^i  ^V®'^?'^'^®'  about  three  times  its  bulk  of  water  ia 

to  tne  surface ;  when  they  are  removed,  the  evaporation  goes  on  as  before     If  t  e  J  f, 
fon  t«  st.U  too  much  coloured,  another  dose  of  "Crater  mfst  be  given     A  litde  p^U^ 


. 


-  1 


PYROLIGNOUS  ACID. 


627 


toon  enables  us  to  know  where  the  evaporation  should  be  checked.  The  onlinary  \iiotb<^d 
is,  to  rinse  a  ladle  (which  is  used  to  skim  off  the  tar  from  the  solution)  through  tlu» 
liquid,  and  observe  how  mkny  drops  of  solution  fall  from  it  before  the  solution  taki's  a 
stringy  appearance  ;  if  only  10  or  12  fall,  then  it  is  strong  enough.  The  liquifl  is*  now 
ladleU  out  into  malleable  iron  pans,  5  ft.  long,  by  3  ft.  broad,  and  about  6  inches  deep,  the 
sides  being  bevelled,  or  sloping  outwards,  from  below  upwards,  to  crystallize.  After  l>e- 
coming  sufficiently  firm,  the  sugar  of  lead  is  taken  out  by  inverting  the  pan  on  a  cloth. 
The  pots  used  in  the  above  process  are  heated  only  at  the  bottom. 

Manufacture  of  the  white  acetate  of  lead. — This  is  prepared  by  dissolving  litharge  in 
acetic  acid  ;  the  acetic  acid  is  first  placed  in  a  vessel,  and  the  litharge  added  by  degrees, 
well  stirring  the  mixture  until  the  solution  does  but  slightly  redden  litmus  paper;  a 
quantity  of  water,  equal  to  about  one-half  of  the  acid*  employed,  is  then  run  into  the  lead 
solution ;  heat  is  next  applied,  and  the  mixture  slowly  evaporated  for  about  12  hours,  or 
until  it  has  acquired  a  density  of  about  1-600.  During  evaporation  any  impurities 
which  rise  to  the  surface  are  skimmed  off,  and  when  the  solution  has  acquired  its  proper 
density,  it  is  run  off  into  the  crystallizing  pans.  When  the  mass  of  crystals  has  become 
sufficiently  hard  to  allow  of  its  removal  en  masse  from  the  crystallizers,  it  is  drained  and 
placed  on  wooden  racks  in  the  drying  house,  and  when  dry,  cleaned  and  broken  up  into 
u'agments  for  the  market. 

The  mother  liquor,  containing  neutral  and  basic  acetates  of  lead  and  other  metallic  salts, 
may  either  be  treated  with  vinegar,  evaporated,  recrvstallized,  and  the  residue  employed 
as  washings  in  subsequent  operations,  or  it  may  be  decomposed  by  carbonate  of  soda  or 
lime,  and  used  as  carbonate  of  lead,  or  dissolved  in  acetic  acid,  and  the  superuatent 
acetate  of  soda  or  lime  recovered. 

Tlie  vessels  employed  in  the  manufacture  of  acetate  of  lead  are  in  most  cases  made  of 
lead.  In  Wales  the  mixing  pans  are  of  lead  f  of  an  inch  thick,  7  ft  long  by  ^  ft  wide, 
and  1  foot  deep.  Those  pans  are  set  on  iron  plates  over  arches,  and  the  fireplaces  are 
outside  the  building,  m  order  that  the  acetate  may  not  be  darkened  by  the  sulphurous 
vap)urs  from  the  coal.  The  crvstallizing  pans  are  of  wood  lined  with  thin  copper,  and 
are  about  4  ft.  long  by  2  ft  wide,  and  from  6  to  8  mches  deep,  sloping  inwards  at  the 
edges.  At  Pitchcombe  the  mixing  and  crystallizing  vessels  are  both  of  copper,  having  a 
strip  of  lead  soldered  down  the  sides  and  across  the  bottom  of  the  vessel  to  render  the 
copper  more  electro-negative :  there  is  thus  no  action  on  the  copper  from  the  acetic  acid. 
Great  care  is  requisite  in  the  drying  of  the  sugar  of  lead ;  the  temperature  of  the  drving 
house  should  not  exceed  90°  Fahr.  In  Wales  the  heated  air  of  a  stove  placed  outside  the 
drying  house  is  conveyed  through  pipes  passing  round  the  interior  ;  at  other  places  steam 
heat  is  employed  for  this  purpose,  which  is  much  to  be  preferred  on  account  of  its  being 
more  easily  regulated. 

We  now  come  to  speak  of  the  product  of  sugar  of  lead  from  a  given  quantity  of  li- 
tharge. 112  lbs.  of  good  Newcastle  litharge  should  produce  187  lbs.  of  sugar  of  lead  by 
the  employment  of  127  lbs.  of  acetic  acid  of  spec,  grav.  1057,  but  not  more  than  180  lbs. 
is  obtained  in  practice.  In  one  set  of  works  in  Wales,  a  ton  of  Welsh  litharge  produces 
with  the  acid  obtained  from  1  ton  of  acetate  of  lime,  from  28  to  30  cwt.  of  sugar  of  lead  * 
and  in  another  manufactory  1  ton  of  best  Newcastle  litharge,  with  the  acid  from  1  ton  and 
a  half  of  acetate  of  lime,  produced  33  cwt  of  acetate. 


ecut 


The  following  process  with  metallic  lead,  recommended  first  by  Berard  is  easilv  ex- 
uted  and  is  said  by  Runge  to  yield  a  good  product  with  great  economy.  '  Granulated 
lead,  the  tailings  in  the  white  lead  manufacture,  Ac,  are  put  in  several  vessels  (say  eio-ht) 
one  above  the  other,  on  steps,  so  that  the  liquid  may  be  run  from  one  to  the  other  The 
upper  one  is  filled  with  acetic  acid,  and  after  half  an  hour,  let  oflF  into  the  second  after 
another  half  hour  into  the  third,  <fec.,  and  so  on  to  the  last  or  eighth  vessel  The  acid 
causes  the  lead  to  absorb  oxygen  rapidly  from  the  air,  evolving  heat,  so  that  when  the 
acid  runs  off  from  the  lowest  it  is  thrown  on  the  upper  vessel  for  the  second  time  it  forma 
a  certain  quantity  of  acetate  of  lead  in  solution,  and  after  passing  through  the  whole 
series  is  so  strong  that  it  may  be  evaporated  at  once  to  crystallize.  There  are  two  points 
of  importance  in  this  manufacture ;  whatever  method  may  be  pursued,  they  are  to  emplov  a 
strong  acid,  that  less  time  and  acid  may  be  lost  in  concentrating  the  liquid  and  to  keen 
the  solution  always  acid,  to  prevent  the  formation  of  a  basic  salt.  ' 


A  vessel  is  provided  of  adequate  capacity  for  the  quantity  of  acetate  require(f,  and  con- 
structed of  such  material  as  will  not  be  readily  destroyed  by  the  acid.  The  top  of  this 
vessel  IS  closed  hermetically  by  a  cover  fastened  down  by  any  convenient  means,  and  in 
the  lower  part  of  the  vessel  is  placed  either  a  minutely  perforated  false  bottom,  or  a  coiled 
tube  of  several  convolutions,  minutely  perforated  to  admit  vapour  to  pass  throu'^h  freely 
To  prevent  the  loss  of  acid,  there  is  also  placed,  at  different  degrees  of  elevation  several 


628 


PYROLIGNOUS  ACID. 


t 


■  ( 


^i 


11 


SfoJ  ?!  1  ^'^P^."^.??*'  "°^  to  the  false  bottom  just  mentioned,  on  each  of  which  is 

^ZJni^J'u?!    f^"^\^^l^^  y^''^  *^'  ^^"''  °^  *^«  ^««««1  i«  t«^l>«  accurately  closed 

^JiZfZt  '^'J'a^  distillatory  apparatus,  liquid  acetic  acid  (strong  or  weak,  pure 

or  impure)  is  converted  mto  vapour,  which  vapour  is  conducted  by  means  of  a  dIm  into 

the  convoluted  perforated  pipe  before  mentioned,  or  between  the  red  botZ^f  the 

vessel  and  the  perforated  false  bottom;  hence  the  vapour  passing  through  theTumLlu^^ 

perforations  of  the  false  bottoms  and  diaphragms,  diSases  r^elf^throuTeverriSrt^^^^ 

the  vessel  Its  acid  entering  into  combination  with  the  base  employed,  and  foTm^f  the 

aceta  e  which  falLs  to  the  bottom  of  the  vessel,  and  in  its  descent  mLts  SthTLsJend! 

ing  streams  of  vapour,  the  acid  of  which  renders  it  perfectly  neutral-  meanwhile  the 

more  aqueous  parts  of  the  vapour  become  liberated,  and  maintaining  their  temTrature 

ascend,  and  in  the.r  passage  through  the  successive  layers  of  the  base  are  thereby  d^S 

of  their  remaining  acid.     The  vapour  thus  reduced  to  simple  steam  is  allowed  to  escIS 

through  one  or  more  pipes  at  the  top  of  the  vessel;  and  as  this  stream  still  maintains 

a  boihng  temperature  it  is  conducted  through  a  worm  to  evaporate  the  acetate  or  the 

mother-liquor,  by  its  heat.    The  distiUation  of  the  acid  is  continued  until  the  acetate  in 

the  vessel  is  arrived  at  the  proper  degree  of  concentration  for  crystallization,  which  ie 

easily  ascertained  by  examining  a  small  quantity  drawn  off  by  a  cick  at  the  bottom  of 

letir'  ^^^  ^^*'^''  ^^""^^"^  ^"^  discharged  when  the  operation  in  com- 

As  the  operation  draws  to  its  close,  by  nearly  aU  the  base  having  combined  with  the 
acid,  the  vapour  issues  out  of  the  vessel,  charged  with  a  certain  portion  of  acid  ;  and  in 
order  that  no  loss  may  be  sustained  by  its  escape  into  the  atmospEere,  it  is  conducted  into 
another  vessel,  prepared  like  the  first  mentioned,  but  charged  super-abundantly  with  the 

^'  ,x  h  "f  ^'^^'^  P^'*'"^^,  ^^  *^^  ^"'^  ^««"^S  «"t  ^^  *^«  first  vessel,  until  the  opera- 
tion m  that  first  vessel  was  ended.  As  the  temperature  of  the  solution  of  the  acctatrcan 
never  exceed  that  of  the  vapour,  the  crystalline  product  is  of  fine  quality 
./a  V":-^^^"/^*^^'-^  0/  acetic  acid.  In  treating  of  the  manufacture  of  acetic 
acid,  we  shall  not  enter  upon  any  other  processes,  than  those  of  the  decomposition  of  the 
acetates,  as  effected  either  by  heat  or  by  sulphuric  acid 

^^f'^'^^^fi!'^  ''^^f'^i  ^y  decomposition  of  the  acetates  hy  mean»  of  heat. -^Aromatic  vine- 
gar     We  have  already  mentioned,  whilst  speaking  of  the  produce  of  pyro  acetic  soirit 
that  when  the  acetates  are  submitted  to  dry^distiultion,  acetk  acid  is  pureed   l^rfol-' 

iZTn^o^f  k""".!     Z''*'^''^  ^'?^  *^/  1*^^^  *^^"  *1"«*^^'  «^°^i°g  the  quantity  of  acetic  acid 
obtained  by  the  decomposition  of  the  metallic  acetates :—  ^ 


Acetate  of  silver 

do.  copper 

do.  nickel 

do.  inm 

do.  lead 

do.  zinc 

do.  manganese 


107-309 

84-868 

44-781 

27-236 

8-045 

2268 

1-286 


The  crystallized  acetate  of  copper  is  the  salt  most  usuaUy  employed  for  this  purpose. 
20  pounds  of  the  powdered  acetate  are  placed  in  an  earthen  retort  of  the  capacity  of 
about  two  gallons,  previously  luted  and  exposed  to  the  action  of  the  fire  ;  the  elongated 
neck  of  the  retort  is  connected  with  a  tubulated  receiver,  and  this  with  a  seconi  and 
third  the  last  of  which  is  furnished  with  a  Wetter's  safety  tube,  dipping  into  water 

^^wnK^l^^/^'S^'^!^""^.^??"^^  *^^°  gradually  Increased,  and  the  operation 
regulated  by  the  development  of  the  gaseous  products,  which  must  not  be  too  S)w  or 
too  fast.    The  receivers  must  be  kept  cool.     When  on  increasing  the  heat  it  is  found 

tS.  .of/fT^^'L^- ^  ?r"  °^'  *^^.^/^  ^"«*  ^  P«*  ^"*'  "^^  thelpparatus  left  to  cooL 
TTie  acid  thus  obtained  has  a  greenish  colour,  its  sp.  gr.  is  1-061.     pl-om  20  lbs.  of  acetate 

^I'^ff/nAilK^'T  *^*°  ^^  ^^^  **^'^"Sh  ^^^  ^'•e  obtained.  The  residuum  in  the  retort 
T?>o  i„l  ^  ^'S!  "^PJ^*:  '",*  P"^*^"^^  ****«'  "^^^  ^^*h  a  small  quantity  of  charcoal. 
Sfnf^llif  J*^"\«b,t^.ned  IS  next  placed  in  a  glass  retort  of  the^capacity  of 
t^«l  i^  ''rK*?u''^rS.^  'I  *^^P*'^  ^  tutulated  receiver,  and  the  retort  is  heated  by 
means  of  a  sand-bath.  The  first  portions  which  come  over  are  veiy  weak,  and  the  product 
should  be  kept  separate  until  it  comes  over  of  a  density  of  1072;  the  whole  of  the 
remaining  product  is  now  collected  together,  and  the  distillation  continued  to  dryness. 

Jn-!  ^    f  r'  ^  'P.-  ^;  °^  1"^^^  ♦«  1"088.    The  weaker  products  are  redistilled, 

and  Oie  stronger  portions  mixed  with  the  former.    The  9f  lbs.  of  crude  acid  furnish  ii^ 

^  1  n/.^  ^  ^T  ^'1^'  'P'.^-  ^'^^^'  ^  P*»"°^«  **  «P-  g*--  1-042,  and  half  a  lb.  of  sp. 
gr.  1  023.  The  small  portion  of  acetone  which  comes  over  with  the  acid,  imparts  £ 
agreeable  aroma  to  it,  and  the  addition  of  camphor  and  essential  oils  constitutes  the 
aromatic  vinegar  of  commerce. 


PYROLIGNOUS  ACID. 


529 


Manufacture  of  acetic  acid,  bp  the  decomposition  of  acetate  of  »oda  hy  sulphuric  aeid. 
Any  given  quantity  of  crystallized  acetate  of  soda  is  placed  in  a  copper  still,  and  a  hollow 
place  having  been  made  in  the  mass  of  the  crystals,  a  quantity  of  strong  sulphuric  acid. 
equivalent  to  35  or  36  per  cent,  of  the  weight  of  the  acetate  of  soda  employed,  is  then 
poured  in  at  once;  the  crystals  forming  the  sides  of  the  heap  in  the  still  are  thea 
pushed  down  into  the  acid,  and  the  whole  stirred  with  a  long  broad  wooden  spatula; 
the  head  is  then  put  on  and  luted,  and  the  connection  made  with  the  refrigerator. 
Nearly  4  cwt  of  acetic  acid,  of  sp.  gr.  1  060,  may  thus  be  obtained  from  3  cwt.  of  acetat* 
of  soda,  which  only  requires  to  be  passed  through  a  calico  filter  (of  the  form  described  in 
Mohr  and  Redwood's  Practical  Pharmacy,  page  20Z,fig.  211),  on  which  some  animal 
charcoal  has  been  placed,  to  fit  it  for  the  market.  A  small  quantity  of  acetic  ether  is 
often  added  to  flavour  it. 

The  still  employed  should  be  of  stout  copper,  (the  solder  used  in  its  construction 
should  be  silver  solder),  having  its  lower  half  set  in  an  iron  vessel,  which  either  receive* 
the  high  pressure  steam  to  be  used  as  the  heating  medium,  or  contains  oil.  tallow,  or 
fusible  metal,  according  as  either  of  these  substances  may  be  preferred  for  use.  In  the" 
former  case  a  cock  is  placed  at  the  lower  part  of  the  casing,  to  let  off  the  condensed 
steam  from  time  to  time ;  and  in  the  latter  case  the  iron  jacket  is  placed  over  the  fire ; 
the  contents  of  the  still  receiving  sufficient  heat  from  the  heated  tallow,  oil,  or  metal 
■with  which  the  copper  still  is  in  contact.  A  safety  tube  should  be  attached'  to  permit 
the  rise  and  escape  of  the  heated  oil,  <kc.,  should  the  temperature  be  raised  too  high. 

The  head  of  the  still  is  of  earthenware,  and  an  earthenware,  silver,  or  block  tin  worm 
may  be  employed  to  condense  the  acid  vapour,  according  to  the  supply  of  water  which 
can  be  obtained  for  condensation ;  or  a  series  of  Woulfs  stoneware  receivers,  of  about 
20  galls,  each,  one  third  full  of  water,  may  be  connected  with  the  head  of  the  still.  In 
this  latter  case,  at  the  close  of  an  operation,  the  acid  in  the  first  receiver  will  be  found 
to  be  stronger  than  the  second,  the  second  than  the  third,  Ac. ;  and  if  the  union  of  the 
contents  of  the  whole  series  will  not  furnish  an  acid  of  the  strength  required,  the  stronger 
portions  may  be  drawn  off  from  the  first  and  second  receivers,  and  the  weaker  portions 
m  the  third  and  fourth  receivers  may  be  placed  in  the  first  and  second  for  the  next 
operation.  A  silver  arm  to  connect  the  head  with  the  earthenware  worm  is  some- 
times used,  a  regular  supply  of  cold  water  being  kept  dripping  on  the  metallic  arm. 
The  residuum  left  in  the  still  after  the  distillation  of  the  aci<^,  is  sulphate  of  soda, 
which  should  be  m  the  state  of  an  almost  dry  crystalline  powder  when  the  process 
has  been  well  conducted:  this  may  be  dissolved  in  water,  and  the  solution  filtered, 
evaporated,  and  crystallized  ;  or  it  may  be  used  in  the  manufacture  of  acetate  of  soda. 

MaMifaeture  of  glacial  acetic  acid. — Acetic  acid  may  be  obtained  in  a  glacial  state  by 
using  a  dry  acetate  of  soda  from  which  the  water  of  crystallization  has  been  expelled  by 
heat :  to  this  is  added  about  its  own  weight  of  strong  oil  of  vitriol,  sp.  gr.  1-85.  The 
first  I  of  the  product  should  be  collected  separately,  the  last  |  will  crystallize. 

Manufacture  of  acetic  acid  by  the  decomposition  of  acetate  of  lime  by  means  of  sulphuric 
acid.  —  Large  quantities  of  this  acid  are  employed"  in  the  manufacture  of  acetate  of  lead 
and  other  commercial  acetates,  white  lead,  and  emerald  green  ;  also  in  the  preparation 
of  the  inferior  class  of  pickles,  <fec.  Ac.  Much  of  the  rough  acid  is  sent  from  Wales  to 
London  and  purified  by  re-distillation.  This  rough  acid  is  obtained  in  Wales  and  other 
parts  of  the  country  m  the  following  manner:— A  cast-iron  cylinder,  about  4  feet  long, 
and  2  feet  wide,  closed  at  one  end,  is  fitted  with  an  iron  rod  passing  through  its  interior 
and  furnished  with  numerous  projecting  pieces  of  iron ;  which  reach  almost  from  the 
centre  rod  to  the  inner  sides  of  the  cylinder.  The  other  end  of  the  cylinder  is  screwed 
on  so  as  to  be  readily  removed  at  any  time  when  the  cylinder  is  to  be  cleaned  or 
*"rP'J!I  *\  At  ^"u  ]^  .*<*^b«  divided  into  2  parts,  one  of  which,  occupying  a  space 
of  about  f  of  the  whole,  is  fixed  on  the  upper  part,  the  other  \  is  occupied  by  a  moveable 
door,  cosing  an  aperture  through  which  the  contents  of  the  cvlinder  may  be  removed • 
through  this  upper  part  one  end  of  the  iron  rod  above  mentioned  passes,  and  is  attached 
to  an  hanale,  by  means  of  which  a  rotary  motion  is  communicated  to  the  rod  and  its 
appendages,  and  the  contents  of  the  cylinder  are  kept  in  continual  agitation.  This  vessel 
IS  termed  an  agitator.  It  is  placed  in  a  horizontal  position  on  a  mass  of  brickwork  or 
masonry;  at  its  upper  part  is  an  opening,  through  which  the  acetate  of  lime,  sulphuric 
acid  and  water,  are  passed :  motion  is  given  by  steam  or  manual  power.  When  the  mixture 
18  complete  the  door  is  opened,  and  the  contents  of  the  cylinder  discharged  into  a  tub  or 
other  vessel  placed  underneath  the  front  of  the  cylinder.  The  pulpy  mass  is  next  trans- 
ferred to  shallow  iron  trajrs  2  feet  wide,  and  from  2  to  4  feet  in  height,  and  2  inches 
deep.  These  are  placed  m  cast-iron  cylinders  about  5  feet  long  and  8  feet  wide,  and 
each  layer  of  trays  is  separated,  the  one  from  the  other,  by  means  of  iron  rods  placed 
between  them  ;  the  cylinders  are  exposed  to  the  direct  action  of  the  fire,  and  the  acetic 
acid  passes  off  m  the  form  of  vapour,  which  b  condensed  by  passing  it  through  leadco 
worms  munersed  m  cold  water. 

84 


riMMHk 


{ 


t 


1 
.•Ml 


530 


PYROLIGNOUS  ACID. 


This  impure  acid,  which  is  contaminated  with  sulphurous  acid  and  free  sulphur, 
produced  by  the  reaction  of  the  tarry  matter  of  the  acetate  of  lime  or  the  excess  of  the 
sulphuric  acid,  is  then  run  into  leaden  vessels,  placed  in  an  iron  cylinder  and  submitted 
to  distillation.  The  liquid  product  is  condensed  by  passing  it  through  an  earthenware 
worm.  The  acid  in  this  state  is  employed  in  the  manufacture  of  sugar  of  lead.  16 
cwt.  of  brown  acetate  of  lime,  with  75  per  cent  of  sulphuric  acid  of  sp.  gr.  1-770,  and 
10  galls,  of  water,  produce  about  1550  lbs.  of  rough  acid  of  ep.  gr.  1070.  Sometimei* 
a  larger  quantity  of  water  is  employed.  On  a  small  scale  the  following  results  were 
obtained : — 


Acetate  of  lime, 
lbs. 
1 2  Grey 
12    do. 
12  Brown 


Sulphuric  acid. 

lbs. 
9 

9 
9 


Water.        Acetic  acid. 
lbs.  lbs. 

15  produced  23^ 
10        do.       17 
15       do.       18 


Sp.gr. 

1-056. 
1-073. 
1050. 


On  the  large  scale,  1^  ton  of  rough  acetic  acid,  of  sp.  gr.  1-050  should  be  obtained 

from  one  ton  of  good  acetate  of  lime,  and  f  of  a  ton  of  sulphuric  acid.     Acetate  of  lime 

•   may  be  so  prepared,  and  the  decomposition  and  rectifying  processes  so  carried  on,  that 

the  acid  obtained  is  not  readily  distinguishable  from  that  obtained  from  acetate  of  soda. 

At  some  works  copper  stills,  set  over  the  naked  fire,  are  employed,  and  the  acid  is  re- 
distilled in  copper  stills,  set  in  a  sand-heat  Iron  stills  of  various  sizes,  with  a  flat  cover, 
formed  of  magnesian  limestone,  or  of  a  rot^  burnt  clay,  or  of  metallic  tin,  are  also  used. 
Large  stills  are  not  desirable,  because  towards  the  end  of  the  distillation,  decomposition 
of  the  acetic  acid  is  readily  effected  in  consequence  of  the  destruction  which  a  portion  of 
the  mass  in  contact  with  the  bottom  undergoes,  whilst  all  the  acid  contained  in  it  is  being 
dnven  oflF.  The  distillation  should  be  begun  with  a  gentle  fire,  and  should  be  carried  on 
without  much  increasing  the  heat. 

PYROLIGNOUS  or  PYROXYLIC  SPIRIT,  improperly  called  naphtha.  This  is 
employed,  as  well  as  pyroacetic  ether,  to  dissolve  the  sandarach,  shellac,  and  other 
resmous  substances,  which,  under  the  name  of  gums,  are  used  for  stiJBFening  the  bodies  of 
hats.  I  have  alreadv  described,  in  the  article  Pvbolignous  Acid,  how  this  spirit  is 
obtained.  Berzelius  has  found  that  the  crude  spirit  may  be  best  purified  by  agitating  it 
with  a  fat  oil,  in  order  to  abstract  the  empyreumatic  oil ;  then  to  decant  the  spirit,  distil 
it,  first  with  fresh  calcined  charcoal,  and  next  with  chloride  of  calcium.  The  pyrolignous 
spirit  thus  purified,  is  colourless,  and  limpid  like  alcc^l ;  has  an  ethereous  sinell,  some- 
what resembling  that  of  ants.  Its  taste  is  hot,  and  analogous  to  that  of  oil  of  peppermint. 
Its  specific  gravity,  by  my  experiments,  is  0824.  It  readily  takes  fire,  and  burns  with 
a  blue  flame  witht»ut  smoke.  It  combines  with  water  in  "any  proportion;  a  propertv 
which  distinguishes  it  from  pyroacetic  ether  and  spirit 

It  is  not  easy  to  say  what  is  the  real  chemical  nature  of  pyroxylic  spirit  There  is  no 
ultimate  analysis  of  it  that  can  be  depended  upon.  The  properties  of  the  spirit  examined 
by  MM.  Marcet  and  Macaire  differ  from  those  of  our  spirit,  in  refusing  to  combine  with 
water,  like  alcohol.  The  article  on  sale  in  this  country  readily  unites  with  water,  and  in 
all  proportions  with  alcohol. 

Test  far  distinguishing  acetone  fr&m  pyrolignous  acid.  As  there  are  several  fluids  to 
be  met  under  the  name  of  naphtha,  considerable  doubt  existed  as  to  which  of  them  should 
be  used  as  "  medical  naphtha"  by  the  compounder.  The  only  tests  relied  upon,  I  believe, 
for  a  long  time,  were  misoibility  of  the  naphtha  with  water  without  becoming  milky,  and 
its  not  being  blackened  by  a  drop  or  two  of  concentrated  sulphuric  or  of  nitric  acid.  Any 
"  wood  naphtha"  met  with  in  commerce,  when  repeatedly  rectified  over  quick  lime,  will 
be  found  to  stand  these  tests ;  and  hence,  when  so  rectified,  was  considered  to  be  the 
proper  naphtha  to  be  used  in  medicine. 

A  question  subsequently  seems  to  have  arisen  as  to  the  dependence  to  be  placed  upon 
these  tests,  and  it  was  asked,  Is  it  pyroacetic  or  pyroxylic  spirit  that  should  be  used? 
and  how  are  we  to  distinguish  readily  between  the  two  ?  Accordingly  we  find  this  subject 
fully  discussed  in  the  Pharmaceutical  Journal  so  far  back  as  the  year  1843,  (vol  iii.  p.  33.) 

In  this  article  upon  naphtha,  it  is  stated  that  pyroacetic  spirit,  or  acetone,  '*  is  the  kind 
of  naphtha  which  Dr.  Hastings  uses;"  and  a  mode  of  distinguishing  this  fluid  from 
pyroxylic  spirit,  or  ordinary  wood  naphtha,  is  pointed  out,  as  suggested  by  Dr.  Ure.  It 
IS  the  way  in  which  nitric  acid  acts  upon  these  two  diflferent  substances.  This  test  may 
be  depended  upon ;  but  is  almost  dangerous,  as  nitric  acid  of  spec  grav.  1-45  acts  with 
explosive  violence  upon  acetone. 

Chloride  of  calcium  affords  us  a  much  more  ready  and  certain  mode  of  distinguishing 
acetone  from  wood-spirit  naphtha,  the  former  having  no  action  upon  it,  while  the  latter 
dissolves  and  combines  with  it.  It  will  be  found  that  a  drop  or  two  of  a  saturated  solu- 
tion of  chloride  of  calcium,  added  to  pyroacetic  spirit  in  a  test  tube,  is  immiscible  with 
It,  and  separates  after  agitation,  whilst  such  a  solution  is  instantly  dissolved  by  the 
pyroxylic  spirit — Maurice  Scanlan.  ^ 


PYROTECHNY. 


531 


It  should  be  ascertained  beforehand,  that  the  "  naphtha"  under  examination  does  not 
separate  into  two  fluids,  or  become  milky  on  the  addition  of  water. 

On  applying  Mr.  Scanlan's  test,  it  was  found  that  those  specimens  which  had  been  most 
approved  of  as  medicinal  agents  were  pyroxylic  spirit. 

PYROMETER,  is  the  name  of  an  instrument  for  measuring  high  degrees  of  heat 
above  the  range  of  the  mercurial  thermometer.  Wedgewood's  is  the  one  commonly 
referred  to  by  writers  upon  porcelain  and  metallurgy  ;  but  a  better  one  might  be  easily 
contrived. 

P  YROPHORUS,  is  the  generic  name  of  any  chemical  preparation,  genertlly  a  powder^ 
which  inflames  spontaneously  when  exposed  to  the  air. 

PYROTECHNY,  See  Fire-works. 

PYROTECHNY  FIRES  ;  Blue,  Green,  and  Red. 


5  parts 

2     " 

1    "    Mix. 


Blue  Fire. — Nitre  -  -  -  . 

Sulphur  ... 

Metallic  antimony 

Chreen. — Nitrate  of  barytes  -  -  62^  parts 

Sulphur  ...  10^    « 

Chlorate  of  potash  -  -  28^^    " 

Charcoal  and  sulphuret  of  arsenic  of  each    If    ♦«     Mix. 

Med  Fire. — Dried  nitrate  of  strontia   -  -  72  p^ts 

Sulphur  -  -  -  20     " 

Gunpowder  -  -  -  6    " 

Coal  dust  -  -  -  2    **    Mix. 


TTie  following  recipes  for  the  preparation  of  mixtures  for  coloured  fires  were  foiind 
among  the  posthumous  papers  of  tne  late  Professor  Marchand.  The  materials  are 
rubbed  to  a  fine  powder  separately,  and  then  mixed  with  the  hand. 

Dark  Violet. — 60  p.  c.  chlorate  of  potash 
16  sulphur 

12         carbonate  of  da 


Red. — 61  p.  c  chlorate  of  potash 
16         sulphur 
28         carbonate  of  strontia 


12 


Pwjple-red. — 61  p.  c.  chlorate  of  potash 
16         sulphur  , 
2S         chalk 

Rose-red. — 61  p.  c.  chlorate  of  potash 
16  sulphur 

23         chloride  of  calcium    — 

Orange-red. — 62  p.  c.  chlorate  of  potash 
14         sulphur 
84         chalk 

Yellow. — 61  p.  c.  chlorate  of  potash 
16         sulphur 
28         dry  soda 

or,  60  p.  c.  nitre 
16         sulphur 
20         soda 
14        gunpowder 

or,  61  p.  c.  nitre 
17^-       sulphur 
20         soda 
li       charcoal 

L^ht  Blue. — 61  p.  c.  chlorate  of  potash 
16         sulphur 
23        strongly  calcined  alum 

J)ark  Blue. — 60  p.  c  chlorate  of  potash 
16  sulphur 

12         carlxmate  of  copper 
12         alum 


alum 


Pale  Violet. — 54  p.  c.  chlorate  of  potash 
14         sulphur 
16         carbonate  of  potash 
16         alum 

Green,— is  p.  c.  chlorate  of  potash 
17         sulphur 
10         boracic  acid 

Light  Green. — 60  p.  c  chlorate  of  potash 
16         sulphur 
24         carbonate  of  baryta 

For  Theatrical  Illumination. 

White.— %\  p.  c  nitre 

21  sulphur 

15         gunpowder 

or,  76  p.  c.  nitre 

22  sulphur 
2         charcoal 

Red. — 56  p.c.  nitrate  of  strontlan 
24  sulphur 

20         chlorate  of  potash 

Chreen.—iO  p.  c.  nitrate  of  baryta 

22         sulphur  "*- 

18         chlorate  of  potash 

Pinh. — 20  p.  c  sulphur 
32         nitre 

27         chlorate  of  potash 
20         chalk 
1         charcoal 


mmm 


532 
Blue. 


PYROXILINK 


27  p. 

28 

15 

15 

15 


c.  nitre 
chlorate  of  potash 
sulphur 

sulphate  of  potash 
ammooia-sulphate  of  copper. 


.m™ol*;'u,X"o"»p^  '""  *^^  "'  "^  '^^'' "'  «""«  •"'P'""*  of  Pot-1^  and 
uZiJ  »™/°<'ebted  to  that  ingemou,  chemist  for  the  foCing  Llr  '*'" 

If  it  be  dissolved  in  boTli^  XLl  oYhTc^H  ofT^^nH  P^f^^'^'^f  I'M^'  "«»'lj  Pure. 

ffulw^nH!ma     TKo     ^'''^'"'"^J*  ^  ^^^  n^'c^scope,  they  are  seen  to  be  thin  right  rectan- 

colour  between  the  two  sverT^LhVrr'  *"f,."°d^^t^e  microscope,  the  difference  in 
in  free  airTheated  in  a  cloIe7uhit  k  WK  T^''"^  ^^^"^  ^'  ^^^°  ^-  ^*  «"b»"«^«  ^^  300° 
be^ns  to  deL'^';^.s"  anSl"  o  i^;  de'co^ol^^^^^^^  ''  ISnh  ^^P^""^- !^*/«^°  ^  >*  then 
producing  a  bcauUful  blue  colour  wwTSo  •  f  •  ^"^P^""^  acid  decomposes  it, 
from  the^atmosphe  e  ^d  it  Siv  Hi  «  ^  '  '"*?  *^!™f "' ««  ^he  acid  attracts  water 
carbon  of  aXrtv  SL^rJlr  T  ^I'^m^'^  °"  Pl«»'>ful  dilution  with  water,  leaving 
yellow  a/e  toTege't^ble'^r^^^^^^^^  ^^  ^"'T-"*'"^  ^^^^'^  -P-^s  a  permaneo! 


Q. 

«hrl™^?^L"  **ha"°fKld  ",L^^  "'.^r'f  *'>'"  ^  *»  *«  ■^fi-'^-  »W  with 

but  is  now  prohibited  under  s^T^  ^SllU^    i{  Iff '*^^"^"^  >  some  brewers  for  hops. 
or  poison  fo?  flies  penalties.    It  affords  a  safe  and  efficacious  fly-water, 

QUEEN'S  WARE.    See  Pottery. 

me^cuiy        ^^^^^ W»  «  ^  ^«««i  "ame  of  Turbith  Minera;  or  yeUow  subsulphate  of 

in  S  Amer?ca'  ^^l  ^"^  "*  •  ***"  ^T  '^^>«'  ^'  ^^"o^  ^t>  »  tree  which  grows 

and  little  in  water^    S^lutfrof  ^W  5      i   '  ^T^^  soluble  in  alcohol,  hardly  in  ether, 

QUICKLIME ;  see  Lme. 
QUICKSILVER ;  «ee  Mercury. 

covery  an(f  use  of  SmiSs  wJ^      ^1'''''^^''^'"^  ^H^  ^^  «^'*^"»7'  "  ^«  dis. 


QUICKSILVER. 


53^ 


the  gold,  and  imparts  a  white  colour  to  it;  at  the  conclusion  the  metal  is  volatilized  in  4 
•mall  tube,  to  obtain  it  in  the  state  of  the  characteristic  fluid  globule. 

After  a  comparative  examination  of  the  reactions  for  discovering  mercury  in  its  solu- 
tions, we  are  satisfied  that  the  galvanic  or  galvanoplastic  action  is  the  most  sensitive. 
We  have  been  able  to  detect  by  means  of  this  test  the  mercury  in  a  solution  containing 


o"ly  TmrVmr  **»• 


It  is  not  the  galvanic  apparatus  which  Smithson  invented  that  we  employed  in  our 
researches  ;  we  only  preserved  its  principle.  For  toxicological  researched,  this  ingenious 
instrument  would  have  been  subject  to  inconveniences,  which  we  wished  to  avoid :  we  sub- 
stituted for  the  apparatus  of  the  English  chemist  one  in  which  the  vessel  containing  the 
suspected  liquid  was  inverted  in  a  kind  of  funnel  terminating  in  a  tube  drawn  out  to  a 
bore  which  was  almost  capillary,  so  that  the  liquid  might  flow  out  of  it  at  the  rate  of 
about  a  drop  in  5  seconds ;  it  was  caught  in  a  capsule.  The  flow  could  be  regulated 
by  varying  the  inclination  of  the  apparatus.  The  electro-positive  pole  was  placed 
in  the  capillary  tube,  the  negative  in  the  wide  part  of  the  funnel ;  they  were  placed 
nearly  in  contact,  and  both,  or  at  least  those  parts  which  touch  the  liquid,  should  be 
made  of  pure  gold.  When  the  pile  (Bunsen's),  which  consists  of  a  single  pair  of  plates, 
is  in  action,  evolution  of  gas  takes  place  at  both  poles,  and  the  mercury  contained  in  the 
solution  is  deposited  upon  the  electro-positive  pole,  which  it  whitens.  To  be  certain 
that  this  effect  is  produced  by  mercury,  the  metal  need  only  be  volatilized  in  a  reduction- 
tube. 

Being  certain  of  detecting  the  slightest  trace  of  mercury  with  this  apparatus,  we  still 
had  to  find  a  suitable  process  for  separating  the  mercury  from  the  organic  matters,  and 
to  isolate  it  from  them  as  far  as  possible  without  loss.  The  Academy  approved  of  the 
process  of  carbonization  by  sulphuric  acid  proposed  by  us,  and  this  process  is  now  gene- 
rally practised  in  cases  of  medico-legal  inquiry.  We  tested  its  application  to  the  detec- 
tion of  mercury,  and  succeeded  in  this  without  having  recourse  to  distillation,  as  we  at  first 
feared  we  should  be  obliged  to  do.  After  numerous  trials  we  adopted  the  following 
process : — At  a  temperature  of  about  212°  we  liquefy  the  animal  matters  by  one-third 
or  half  of  their  weight  of  monohydrated  sulphuric  acid  in  the  ordinary  manner.  This 
liquefaction  being  completed,  which  requires  only  an  hour  and  a  half,  or  at  the  most 
two  hours,  the  capsule  is  taken  from  the  fire  and  left  to  cool  to  a  certain  extent  Then,  • 
after  having  placed  the  vessel  underneath  a  chimney  with  a  good  draught,  to  protect  the 
operator  against  the  disengagement  of  vapours,  we  throw  into  the  black  carbonized  liquid 
saturated  chloride  of  lime  in  separate  pieces,  stirring  the  mixture  at  the  same  time  with 
a  glass  rod.  By  degrees,  as  the  matter  thickens,  and  becomes  white,  distilled  water  is 
added,  which  favours  the  action  of  the  chlorine,  and  this  is  continued  until  the  liquid  to 
be  separated  by  filtration  appears  almost  colourless.  The  quantity  of  chloride  of  lime  must 
always  be  very  nearly  in  relation  to  the  amount  of  sulphuric  acid  required  for  the  perfect 
liquefaction  of  the  animal  matters.  For  3  ounces  of  silver,  on  account  of  the  bile  and 
fats  which  the  liver  contains,  sometimes  1^  ounces  of  sulphuric  acid  and  H  ounces  of 
chloride  of  lime  are  necessary ;  but  it  is  scarcely  ever  requisite  to  exceed  this  proportion. 
Tlie  substance,  which  is  whitened  and  rendered  of  a  chalky  aspect,  is  well-moistened 
whilst  cold  with  absolute  alcohol,  then  diluted  with  distilled  water  and  filtered,  and  the 
precipitate  washed  repeatedly.  The  liquid,  if  too  abundant,  is  concentrated  by  evapo- 
ration, after  which  it  is  submitted  to  the  action  of  a  galvanic  current,  in  the  apparatus 
described.  It  was  proved  by  experiment  that  the  voltaic  current  favoured  the  precipita- 
tion of  the  mercury  on  the  gold  wire,  and  that  in  all  cases  it  at  least  possessed  the 
advantage  of  accelerating  an  operation,  which  without  the  concurrence  of  tliis  action 
would  perhaps  require  much  time  to  accomplish. 

Tlie  metal  being  obtained  on  the  electro-positive  conductor  of  the  pile,  it  is  necessary 
to  wash  the  gold  wire  in  boiling  aether  or  alcohol  to  remove  all  fatty  matter,  and  to  dry 
it  before  introducing  it  into  the  reducing  tube.  This  should  be  perfectly  free  from 
moisture,  which  might  stain  the  globule  of  mercury,  which  is  sometimes  extremely  small, 
and  must  be  made  perceptible  to  the  eye. 

The  efficacy  and  sensitiveness  of  this  process  has  been  ascertained  by  numerous  ex- 
periments. We  have  required  3  ounces  only  of  the  liver  of  an  animal  poisoned  with 
corrosive  sublimate  to  obtain  an  appreciable  quantity  of  mercury  from  it.  In  future 
therefore  it  will  not  be  more  difficult  to  detect  corrosive  sublimate  than  ai-senious  acid, 
or  any  other  metallic  compound. — Comptes  Rendua,  March  31,  p.  951,  1845. 

QUILL.     See  Feathers. 

QUINIDINE. — Put  100  grains  of  sulphate  of  quinine  in  a  Florence  flask  with 
5  ounces  of  distilled  water  ;  heat  this  to  brisk  ebullition ;  the  sulphate  of  ouinine  ought  not 
to  be  entirely  dissolved ;  add  2  ounces  more  water,  and  again  heat  it  to  eoullition  ;  which 
ought  to  make  a  perfectly  clear  solution.  If  this  be  allowed  to  cool  for  six  hours,  and 
the  crystals  carefully  dried  in  the  open  air  on  blotting  paper,  they  will  be  found  to 
weigh  about  90  gr. ;   the  mother-liquor  may  be  evaporated  and  tested  with  ether,  when 


534 


QUININA. 


QUININE. 


6SS 


any  cinchonine  (or  ^  quinine)  will  be   easily  detected.    On  examining  sulphate  of 
Sln'a  .r^;;^Tf  ^Th ''"''^^  ^'"^!?^  manufacturera.  I  have  fo^d  allVthCgivl, 

The  above  quantity  of  water  (7  ounces)  readily  dissolves  800  grs  of  sulnhate  of 
0  qumine;  and  if  100  grs..  of  this  salt  are  dissolved  in  1  ounces  of  wate^ihe  cry  uds  dried 

J^r^^.Xar^  ^^  ^  '*  ^''"  ^'^"'''^  '^  ^"'  ^"  '^^"''"°'  ^^^^ead  of  al^u^  10  g^^^^^ 

QUININA.      This  medicine  is  now  prepared  in  such  quantities  as  to  constitutP  a 
chemical  manufacture.     Quinina  and  cin^cho^ina  are  two  vVtab  e  at'ka^L  wh  d    exi^ 
m  Peruvian  bark  or  cmchona  ;    the  pale  or  grey  bark  contains  most  cbcl7^ ina   a^ 
the  yellow  bark  most  qumma      The  methods  of  extracting  these  bases  are  very  va;ious 
In  general,  water  does  not  take  them  out  completely,  because  it  transforms  th^e  neu^m 
salts  m  the  barks  mto  more  soluble  acidulous  salts,  and  into  less  soluble  sub-salts.      To 
exhaust  the  bark  completely,  one  or  other  of  the  following  solvents  is  employed  — 
w«L  i.     •  .•    ^^,^?'^^ci   ty    this    menstruum    is    to   be    treated   with   ve;y  dilute 
warm  munatic  acid,  in  order  to  dissolve  every  thing  thus  soluble ;  the  acid  liqior  is  to 
be  saturated  with  magnesia,  by  boiling  it  with  an  excess  of  this  earth  ;    the  precipitate 
18  to  be  dried,  filtered,  and  then  exhausted  by  boiling-hot  alcohol 

2  Dilute  acids  Boil  the  bark,  coarsely  pounded,  with  eight  times  its  weight  of 
water  containing  5  per  cent,  of  the  weight  of  the  bark  of  sulphuric  acid.  Thi?treat- 
Sf^fiu"  A  ^  "^P^.^*^^  ^^^»»  ?  ^'f^  5"antity  of  dilute  acid.  The  whole  liquors  must 
f  S^cX  I  ^f '^"""?  strained,  ancf  the  solution  mixed  with  quicklime,  equal  to  one 
fourth  of  the  bark  employed.  This  mixture,  after  having  been  well  stirred,  is  to  be 
strained,  whenever  it  acquires  an  alkaline  reaction,  that  is,  tinges  reddened  litmus  paper 
blue,  or  turmenc  brown.  Tlie  calcareous  mass  is  to  be  now  washed  with  a  little 
water,  and  dried  and  then  boiled  thrice  with  spirit  of  wine  of  sp.  grav.  0835  Thi* 
solution  being  filtered,  is  to  be  mixed  with  a  little  water,  and  distilled.  The  bases 
cinchonina  and  quinma  remain  under  the  form  of  a  brown  viscid  mass,  and  must  be 
purified  by  subsequent  crystallization,  after  being  converted  into  sulphates 

S.  An  alkah,  and  then  an  acid— The  object  of  this  process  is,  to  retain  the 
vegetable  alkalis  m  the  bark,  while  with  the  alkaline  water  we  dissolve  out  the  acids, 
the  colouring  matters,  the  extractive,  the  gum.  «fec.  Boil  for  an  hour  one  pound  of 
the  bark  with  six  pounds  of  water,  adding  by  degrees  a  little  solution  of  ^tash,  so 
that  the  liquor  may  have  still  an  alkaline  taste  when  the  boiling  is  over.  Allow  it  to  cooL 
filter,  wash  the  residuum  with  a  little  water,  and  squeeze  it.  Diffuse  it  next  in  tepid 
water,  to  which  add  by  degrees  a  little  muriatic  acid,  till  after  a  prolonged  digestion 
the  mixture  shall  perceptibly  redden  litmus  paper.  Filter  the  liquor,  and  boil  it  with 
magnesia.  The  precipitate  being  washed  and  dried,  is  to  be  treated  with  hot  alcohol 
which  dissolves  the  quinina  and  cinchonina. 

Obtained  by  any  of  the  above  methods,  the  quinina  and  cinchonina  are  more  or  less 
coloured  and  may  be  blanched  by  dissolving  them  in  dilute  muriatic  acid,  and  treating 
the  solution  with  animal  charcoal.  ^ 

There  are  several  methods  of  separating  these  two  vegetable  alkalis. 

1.  When  their  solution  in  spirit  of  wine  is  evaporated  by  heat  to  a  certain  point,  the 
greater  part  of  the  cinchomna  crystaUizes  on  cooling  while  the  quinina  remains  dissolved 

2.  Digestion  m  ether  dissolves  the  quinina,  and  leaves  the  cinchonina. 

3.  We  may  supersaturate  slightly  the  two  bases  with  sulphuric  acid.  Now  as  the 
eupersulphate  of  quinina  is  sparingly  soluble,  the  liquor  need  only  to  be  evaporated  to  a 
proper  pomt  to  crystallize  out  that  salt,  while  the  supersulphate  of  cinchonina  continues 
in  solution  with  very  little  of  the  other  salt.      Even  this  may  be  separated  by  pre- 

•cipitating  the  bases,  and  treating  them,  as  above  prescribed,  with  alcohol  or  ether. 

One  pound  of  bark  rarely  yields  more  than  2  drams  of  the  bases.  One  pound  of 
red  bark  aflforded,  to  Pelletier  and  Caventou,  74  grains  of  cinchonina,  and  107  grains  of 
quinina.  »  &  «» 

Quinina  is  composed  of  7576  carbon,  7-52  hydrogen,  811  azote,  and  8-61  oxygen. 

1  he  salts  of  quinina  are  distinguished  by  their  strong  taste  of  Peruvian  bark,  and  if 
crystallized  by  their  pearly  lustre.  Most  of  them  are  soluble  in  water,  and  some  also 
in  ether  and  alcohol  The  soluble  salts  are  precipitated  by  the  oxalic,  gallic,  and  tartaric 
acids,  and  by  the  ^Its  of  these  acids.     Infusion  of  nutgalls  also  precipitates  them. 

The  sulphate  of  quinina  is  the  only  object  of  manufacturing  operations.  Upon  the 
brownish  viscid  mass  obtained  in  any  of  the  above  processes  for  obtaining  quinina.  pour 
very  dilute  sulphuric  acid  in  sufficient  quantity  to  produce  saturation.  The  solution 
must  be  then  treated  with  animal  charcoal,  filtered,  evaporated,  allowed  to  cor.l,  when  ik 
deposits  crystals.  1000  parts  of  bark  afford,  upon  an  average,  12  parts  of  sulphate. 
The  sulphate  of  cmchonina,  which  is  formed  at  the  same  time,  remains  dissolved  in  the 
mother  waters. 


The  neutral  sulphate  of  quinina  occurs  in  small  transparent  right  prismatic  needles. 
By  spontaneous  evaporation  of  their  solution,  larger  crystals  may  be  procured.  They 
contain  24|  per  cent,  of  water ;  and,  therefore,  melt  when  exposed  to  heat.  They  dis- 
solve in  11  parts  of  water  at  ordinary  temperatures  ;  are  much  more  soluble  in  hot  spirit 
of  wine,  somewhat  dilute,  than  in  cold ;  and  are  nearly  insoluble  in  anhydrous  alcohoL 
If  they  be  well  dried,  they  possess  the  property  of  becoming  luminous  when  heated  a  little 
above  the  boiling  point  of  water,  especially  when  they  are  rubbed.  The  sulphate  is, 
in  this  case,  charged  with  vitreous  electricity.  This  is  the  sub-sulphate  of  some 
chemists. 

There  is  a  sub-sulphate,  but  it  is  applied  to  no  use.  The  effloresced  sulphate,  called 
by  some  bisulphate,  is  preferred  for  medical  practice.  The  extensive  sale  and  high 
price  of  sulphate  of  quinina.  have  given  rise  to  many  modes  of  adulteration.  It  has 
been  mixed  with  boracic  acid,  margaric  acid,  sugar,  sugar  of  manna,  gypsum.  <fcc.  By 
incinerating  a  little  of  the  salt  upon  a  slip  of  platina,  the  boracic  acid  and  gypsum  re- 
main while  the  quinine  is  dissipated ;  sugar  and  margaric  acid  exhale  their  peculiar 
smoke  and  smell ;  or  they  may  be  dissolved  out  by  a  few  drops  of  water.  Cincho- 
nina may  be  detected  by  adding  ammonia  to  the  solution,  and  treating  the  precipitate 
with  ether,  which  leaves  that  vegeto-alkali. 

Sulphate  of  Quinine  tested.  — A  solution  of  sulphate  of  quinine  being  mixed  with 
chlorine  water,  and  then  with  caustic  ammonia,  produces  a  beautiful  emerald-greeii 
colour.  If  an  excess  of  concentrated  solution  of  the  ferrocyaoide  of  potjvssium  be 
added  instead  of  ammonia,  a  dark-red  colour  is  instantly  produced,  which  after  some 
hours  passes  into  green,  especially  when  exposed  to  light.  This  reaction  is  charae- 
teristic  of  quinine.  If  caustic  potash  is  used  instead  of  the  ammonia,  the  solution  ac- 
quires a  sulphur -yellow  colour.     These  reactions  do  not  take  place  with  cinchonine. 

Determination  of  the  quantity  of  water. — 25  grammes  of  sulphate  taken  from  a  bottle 
the  contents  of  which  were  thoroughly  mixed,  were  dried  in  a  closet  heated  by  b<iiling 
water.  The  loss  was  039  gr.,  answering  to  15 '6  per  cent,  of  water,  or  to  7  equiva- 
lents and  a  half.  This  quantity  of  water  is  that  which  is  usually  found  in  the  half 
effloresced  sulphate  of  commerce. 

This  sulphate  does  not  redden  on  the  addition  of  concentrated  sulphuric  acid,  and  does 
not  contain  salicine. 

When  concentrated  sulphuric  acid  is  added,  it  assumes  a  very  pale  greenish  yellow 
colour,  which  might  be  supposed  to  indicate  the  presence  of  a  small  quantity  of  phh- 
ridzine.  But  as  it  does  not  undergo  the  least  coloration  when  exposed  under  a  receiver 
to  the  vapour  of  liquid  ammonia,  it  is  evident  that  that  substance  is  not  present. 

Tliis  sulphate  is  very  slightly  soluble  in  cold  spirit,  containing  90  per  cent  of  alcohol ; 
but  it  dissolves  completely  and  very  rapidly  on  the  application  of  moderate  heat.  This  expe- 
riment shows  that  it  contains  neither  gum,fecxda,  sulphate  of  lime,  suffar  of  milk,  nor  even 
9ugar. 

This  sulphate  is  completely  soluble  with  heat  in  water  acidulated  with  sulphuric  acid ; 
it  therefore  contains  neither  /a/<!/  acid  nor  sub-resin. 

Test  by  Baryta.  —In  order  to  ascertain  if  the  sulphate  of  quinine  contains  si^ar, 
salicine,  phloridzine,  mannite,  Ac.  and  to  affect  the  separation  of  one  from  the  other  of  these 
substances,  the  addition  of  baryta  water  to  the  dissolved  sulphate  has  been  recommended ; 
but  whether  we  operate  thus,  or  triturate  the  pulverized  sulphate  with  an  excess  of 
baryta-water  during  some  length  of  time,  we  can  only  succeed  iu  producing  a  sub-sul- 
phate of  quinine,  sensibly  soluble  in  cold  water,  and  partaking,  in  common  with  quinine 
itself,  of  the  property  of  becoming  insoluble  on  the  application  of  heat.  To  detect  tht 
presence  of  sulphate  of  cinchonine  2*5  grammes  of  sulphate  of  quinine,  taken  from  a  per- 
fect mixture  of  the  sulphate  contained  in  a  bottle  of  30  grammes,  were  introduced  into  a 
bottle  with  15  grammes  of  liquid  ammonia.  After  having  thoroughly  agitated  the 
mixture,  it  was  allowed  to  stand  for  24  hours,  in  order  to  be  certain  of  the  entire  de- 
composition of  the  sulphate.  It  was  then  heated  in  a  water  bath,  so  as  to  almost 
entirely  volatilize  the  excess  of  ammonia ;  then  left  to  cool,  and  30  grammes  oi pure  ether 
added.  By  agitation,  the  quinine  rapidly  and  entirely  dissolved,  so  that  two  superposed 
transparent  liquids  were  in  the  bottle,  — namely,  the  water  containing  the  sulphate  of 
ammonia  and  the  ether  containing  the  quinine.  This  experiment,  which  is  very  accurate, 
proved  to  us  that  the  sulphate  of  quinine  submitted  to  our  examination  did  not  contain 
sulphate  of  cinchonine. 

Adulteration  of  Sulphate  of  Quinine. — The  high  price  of  the  genuine  Bolivian 
Cinchona  Calisaya,  through  the  monopoly  of  its  export,  has  given  occasion  to  imports 
from  other  districts  of  Cin<;honas,  the  quality  of  which  widely  differs  from  that  of  the 
Calisaya,  inasmuch  as  they  contain  principally  quinidine.  The  lower  prices  of  these 
barks,  regardless  of  their  different  constituents,  have  brought  them  quickly  into  use  ia 
many  manufactories  of  quinine,  whereby  a  large  quantity  of  quinine  containing  quini* 
dine  has  got  into  the  market,  causing  an  undue  depreciation  in  the  price  of  quinine. 


636 


QUININE. 


'        ! 


S[ 


1     (■ 


tim?t::nal,Zb;fh:^  «  no.  established  beyond  a  doubt  by  nU 

there  can  be  no  further  question  that  onfnn  ^^  ^^^Po^ant  distinctive  tests;  and 
distinguished  from  quininr  '^e  ezternircW?..  ™"'';  "^"^"^  ^'^»'  cinchonine.  be 
from  those  of  sulpha^  of  quin  ne  iThas  a  Greater  /rt  -^^  '"^P^^'"  ^^  ^"'""^'"^  ^'^er 
crystallization,    in   dry  warm   aiV    t  dL^s^wTh  if!'^''^  ^^^^ 

deliquescing  or  losing  li  crysTallizedXect-T^tlv  If  "^T  ^^  crystallization  without 
of  quinine  in  cold  water  an/in  alXf^       '  '  ' ''  *"  ^^''"^'"^  ^^^^^^^  than  sulphate 

One  of  the  distinctive   properties  of  the  three   alkiilnJrla  ;„ 
behaviour  with  ether— places  in  our  hand.,  a  rpmitr^  r  j  "  question— viz.   their 

cinchonine  and  quinidiL  with  qu  n ine  LhwitzTrT.  ''S^'iJ'i'"^  '^'  "^'^^^--^  ^^ 
p.  175.)  has  already  employed  eS^r  for  the  ditfrHin  /•  ^u'^-  ^'^"^"^'  ^'«^  «*• 
•access;  «nd  his  proLs  hL  ^ith  ju  Uce^^^^^^^^^  ^'th  complete 

It  answers  its  purpose  completelv  CinchoiWnP  f"?^^^q"^»/'y  Quoted  m  most  manuals,  as 
whatever  mayV  the  quanf^tTofetS    eZl^^^^  to  be  entirely  insoluble  in  ether, 

as  compared  with  that  of  quinine  is  buHE     *  ««l"b»hty  of  nuinidine  in  ether 

process  for  Ibe  detection  of  quinidine  and  cinchonine--^     ^     ""''   "'"^  "^"""ni™* 

(1  acid  with  6  wafer),  wi  h  15  dro™  of  w^ter  f^d  .**  ''''.r.."'  *'"""'  '"'P''""''  '•"d 
the  solution.  This  having  been  effected  and  the  -l^t"''  *"!?'  ,*PP"^  to^ccelerate 
«fficinal  sulphuric  ether  with  20  drops  of  sni,f,n^°  ^nt'rely  cooled.  60  drops  of 
whole  welfshaken,  while  the  t„pTcl3  bv  tl  L  rT"  nT  't  '"'''"'■  ^  'h' 
llosely  stopped,  and  shaken  gentl^frotn  ttoe  to  tW  LTi  ■,  l?"  ^"^^  «  "'™  «»  •» 
Bore  readily  enter  the  layer  of  ether  '  ""  """  "'«  '""''"«'  "'  »''  may 

.o'^tte?';:^rnibt  irpLTj i-ttm  ^t  'nfr-  7- «"--"  *'-' "'«"  - 

.urface,  wh'en  "contact  of  the  TwoTaye  I  ckar  Z  "'."^  ''T'™'''  '''"'''  ""  «'« 
impurities  only  will  be  separated  (h.wh"ch  reZ.«  .1  "^  P'*"'  ""  '"ech.-.nical 
quinine  difTer)."^  After  some  time  loncier  the  lavlr  o'^  K  J!"""'  .'""'  "'  «on""ercial 
after  which  ni  further  observation  is'^siWe^  ""^  "^""^^  ^'^  ""J  g-^'atioous. 

From  the  above  statement  respectin?  the  anlnKilii^  „r  „  •  ■  i- 
U.at  the  10  grains  of  the  salt  to  ^e^^„M  may  c^,f,ab  ?  Jr^"'f"'  -"T'  "  "PP*"" 
a  complete  solution  with  ether  and  ammouii  n^v  Mu^  l^.™  .?•'  I"'""!'"".  ai>d  still 
will  shortly  begin  to  crystallize  in  aZ"r  of  eS  t  ii, . '"  **"',  '"''  ">'  'J'"™'''"' 
yet  n.ore  definitively  Setected  by  emfjovb '  insi.-H  f  ?^  "■"?  "'  quinidine  may  be 
previously  saturated  with  quinidiL? bf  Xh  me^,s  Jl  oJX"''""'? ^■""'-  '""^  "*« 
the  qumine  must  remain  undissolved^  It  is  mrUcularlv  r„^-  '»;"■'.«'■"«  contained  in 
fast  experiment  to  observe,  after  the  shaking  CheJ  an  h»?T  %'"  r/»™i"g  *i. 

Wl^be^dissolved  on  the  addition  of  proportionatel^l":  X  willfcL^lne^IlT',^ 

infl^r^'trth^^rSn'o^a'^Srl-stsltTolit^^^^^        "^="*''  -"••  *"■•  >»-  >« 
thesuspected  sal,  When,  if  present.  It^iuttlt^^^^^^^^^^^^ 

-it  tfm^;7hrk^{wr/rttre  t  sz.y:?  '^'"'"'' "» ^'-  ^-'-"^  ^-"v- 

io  point  of  c^l^ur  as  the  usual  artli;  of  c^^me™.'''""'"*  "J""'>"«'».  but  not  so  wlit. 

I 


RAILWAY  TRAIN  BREAK. 


537 


I*  You  are  aware  that  the  whiter  salt  is  brought  to  its  snow  white  hue  by  the  agency  of 
animal  charcoal,  the  action  of  sulphuric  acid  therefore  on  the  lime  and  lime  salts  of  the 
charcoal,  forming  sulphate  of  lime,  is  likely  to  be  present  in  the  white  kind,  unless  very 
carefully  prepared.  This  hospital  sulphate  runs  no  chance  of  such  impurities,  as  the 
publislied  process,  when  patented,  will  show. 

"  The  price  at  which  it  is  introduced  is  perhaps  of  no  moment  to  you,  but  it  may  be 
interesting  to  you  to  know  that  it  will  cost  consumers  about  20  per  cent,  less  than  the 
white  kind.  Independently,  therefore,  of  its  purity,  I  expect  this  great  saving  will  not 
be  the  least  of  its  recommendations. 

"  The  bark  is  boiled  in  a  solution  of  caustic  soda.  This  extracts  the  colouring  matter 
and  gum  of  the  bark :  it  is  pressed,  washed  with  cold  water,  and  again  boiled  with  cau8> 
tic  potash — again  pressed,  washed,  and  again  pressed.  The  bark  is  now  free  of  all 
colouring,  and  hence  obviating  the  use  of  animal  charcoal,  unless  the  sulphate  is  required 
to  be  quite  white — in  which  case  I  use  pure  animal  charcoal 

"  The  pressed  bark  is  now  boiled  in  acid  and  water,  and  this  for  the  first  time  dissolves 
the  quina.  This  is  precipitated  by  soda,  and  thus  the  pure  quina  is  formed.  On 
treating  with  acid,  sulph.,  the  hospital  sulphate  of  quinine  crystallizes  at  once.  You 
now  therefore  see  by  this  sketch  that  no  impurity  can  exist,  and*  the  action  of  the  caustic 
soda  on  the  bark  sufficiently  bleaches  the  quina  without  the  aid  of  charcoal.  The 
treatn^nt  of  the  soda  liquor  is  rather  a  troublesome  operation,  but  all  of  which  will  ap- 
pear in  the  patent." — Extract  of  a  letter. 

I  have  found  Mr.  Herring's  hospital  sulphate  of  quinine  to  be  a  good  article,  cont^n- 
ing  within  a  few  per  cents,  as  much  base  as  the  whitest  in  the  market. 

QUINTESSENCE.  The  alchemists  understood  by  this  term,  now  no  longer  in 
scientific  use,  the  solution  in  alcohol  of  the  principles  which  this  menstruum  can  extract 
from  aromatic  plants  or  flowers,  by  digestion,  during  some  days,  in  the  sun,  a  stove,  or 
upon  a  sand-bath  slightly  warmed.  A  quintessence,  therefore,  corresponds  to  the  alco- 
holic tincture  or  essence  (not  essential  oil)  of  the  present  day.     See  Perfumery. 


R. 


RAILWAY  TRAIN  BREAK.  Patent  break  for  railway  trains,  designed  to 
obviate  the  serious  defects  of  the  common  railway  break.  The  first  advantage  which 
it  presents  is  an  improvement  as  to  the  permanent  way,  which  is  effected  by  the  use  of 
the  long  shoe,  by  having  18  inches  of  clearing  surface  upon  the  rails;  it  will  slide 
over  the  soft  and  bad  places  hitherto  made  worse  by  the  application  of  the  ordinary  break, 
the  wheels  having  only  about  one  inch  of  surface.  The  ends  of  the  rails  will  not  be 
jumped  up,  or  flattened  by  the  wheels  coming  in  contact  with  them,  which  is  now 
the  case,  as  the  wheels,  resting  upon  the  shoe,  will,  in  fact,  press  such  irregularities 
down.  • 

llie  second  advantage  is  that  in  the  locomotive  department,  the  wheels'  tires  are  always 
preserved  perfectly  circular,  and  the  shoe,  by  bearing  up  the  wheel  when  the  br^ak  is 
applied,  prevents  the  flat  places  being  formed,  and  also  torsion  upon  the  axles.  The 
wheels,  whether  of  wood  or  iron,  are  saved  from  being  strained,  and  the  tires,  rivets,  bolts, 
Ac.  are  not  liable  to  get  loose,  an  evil  which  is  caused  by  their  becoming  heated.  The 
carriage  frame  is  also  saved  from  being  racked  and  twisted,  as  the  patent  break  is 
suspended  from  the  axle  only.  This  will  cause  a  great  saving  in  the  repair  of  break 
carriages.  By  the  adoption  of  this  break  a  power  is  gained,  when  applied  to  2  wheels 
only,  fully  equal  to  the  usual  breaks  applied  to  6,  a  feature  of  no  slight  importance  in 
cases  of  danger.  This  power  in  retarding  a  train  is  also  always  the  same,  which  is  not 
the  case  with  the  common  break.  The  different  weights  with  which  the  carriages  are 
loaded  are  continually  altering  the  position  of  the  blocks,  which  varies  the  number  of 
turns  of  the  screw  necessary  to  apply  the  ordinary  break  ;  while  in  wet,  greasy  weather, 
it  is  almost  impossible  to  skid  the  wheels.  The  patent  break  can  be  applied  in  less 
time  and  with  2  or  3  turns  only  of  the  screw,  whereas  6  or  7  turns  are  required  with 
that  hitherto  in  use.  It  is  also  free  from  the  usual  unpleasant  noise,  smell,  and  sensation 
from  friction. 

Lastly,  considerable  saving  is  effected  both  in  the  amount  of  stock  required  and  in  the 
wear  and  tear  of  railway  apparatus, — Montgomery  s  patent. 

The  necessity  for  the  introduction  of  an  improved  railway  break  is  universally  admitted 
by  all  engineers  and  practical  men.  The  breaks  in  common  use  are  very  injurious, 
both  with  regard  to  the  duratulity  of  the  wheels  and  rails.     Timber  blocks  of  poplar 


It  1 


i  I 


1    i 


'<  i 


638 


RAZORS. 


wood  are  made  to  bear  hard  upon  the  peripheries  of  the  wheels,  so  as  to  stop  their 
revolution.  The  result  is  the  grinding  of  many  flat  places  on  the  tire  of  the  wheels  and 
the  abrasion  of  the  rails,  occasioning  frequent  renewal. 

RAISINS,  are  grapes  allowed  to  ripen  and  dry  upon  the  vine.  The  best  come 
from  the  south  of  Europe,  as  from  Roquevaire  in  Provence,  Calabria,  Spain  and  Por- 
tugal. Fine  raisins  are  also  imported  from  Smyrna,  Damascus,  and  Egypt.  Sweet 
fleshy  grapes  are  selected  for  maturing  into  raisins,  and  such  as  grow  upon  the  sunny 
elopes  of  hills  sheltered  from  the  north  winds.  The  bunches  are  pruned,  and  the  vine 
is  stripped  of  its  leaves,  when  the  fruit  has  become  ripe;  the  sun  then  beaming  full 
upon  the  grapes  completes  their  saccharification,  and  expels  the  superfluous  water.  Tlie 
raisins  are  plucked,  cleansed,  and  dipped  for  a  few  seconds  in  a  boiling  lye  of  wood  ashes 
and  quicklime,  at  12  or  13  degrees  of  Beaum6's  areometer.  The  wrinkled  fruit  is  lastly 
drained,  dried  and  exposed  in  the  sun  upon  hurdles  of  basket-work  during  14  or  15  days. 

The  finest  raisins  are  those  of  the  sun,  so  called  ;  being  the  plumpest  bunches,  which 
are  left  to  ripen  fully  upon  the  vine,  after  their  stalks  have  been  half  cut  through. 

The  amount  of  raisins  imported  for  home  consumption  was  m  the  year  1850, 
218,982  cwts.;  in  1851,  208,801  cwts. ;  duty  received,  1850,  172,260/.;  1851,  164.401/. 

RAM  HYDRAULIC.  Originally  invented  by  Montgolfier,  in  France,  and 
patented  by  him  in  1797. 

This  machine,  which  is  self-acting,  is  composed  of  an  air  vessel  and  3  valves,  2*  for  the 
water  and  1  for  keeping  up  the  supply  of  air.  Upon  pressing  down  the  valve  in  the 
conducting  tube,  which  opens  downwards,  the  water  escapes  from  it,  until  this  momentum 
is  sufficient  to  overcome  the  weight,  when  the  valve  immediately  rises  and  closes  the 
aperture.  The  water,  having  then  no  other  outlet  than  the  inner  valve,  rushes  through 
it  by  its  general  force,  compressing  the  air  in  the  air  vessel  until  equilibrium  takes 
place,  when  the  air  reacts  by  its  expansive  force,  closing  the  inner  valve,  which  retains 
the  wajter  above  it,  and  driving  it  up  the  ascending  tube.  By  this  reaction  the  water  is 
forced  back  along  the  conducting  pipe,  producing  a  partial  vacuum  beneath  the  outer 
valve,  which  immediately  falls  by  its  own  weight.  The  water  thus  escapes  until  it  has 
acquired  sufficient  force  to  close  this,  when  the  action  proceeds  as  before.  It  is  best 
adapted  for  raising  moderate  quantities  of  water,  as  for  household  or  farming  pur- 
poses. 

RAPE-SEED,  imported  for  home  consumption  in  1850,  107,029  qrs. ;  in  1851, 
82,394  qrs.     See  Oils,  unctuous. 

RASP,  MECHANICAL,  is  the  name  given  by  the  French  to  an  important  ma- 
chine much  used  for  mashing  beet-roots.     See  Sugar. 

RASPS  AND  FILES.  File-making  is  a  manufacture  which  is  still  in  a  great 
measure  confined  to  Sheffield.  It  is  remarkable  that  hitherto  no  machine  has  been  con- 
structed capable  of  producing  files  which  rival  those  cut  by  the  human  hand.  Machine- 
made  files  have  not  the  "  bite  "  which  hand-cut  files  have :  this  is  accounted  for  by  the 
peculiar  facilities  of  the  human  wrist  to  accommodate  itself  to  the  particular  angle 
suitable  to  produce  the  proper  "  cut"  *'  Small  files  are  made  out  of  the  best  cast  steel; 
those  of  a  larger  size  from  ordinary  steel ;  flat  files  are  forged  on  an  ordinary  study. 
Other  forms  on  bolsters,  with  the  intlentature  corresponding  to  the  shape  required  being 
thereon  impressed,  a  chisel  wider  than  the  blank  to  be  cut  is  used  as  the  only  instrument 
to  form  the  teeth  :  it  is  moved  by  the  hand  with  the  greatest  nicety.  After  cutting  and 
previous  to  hardening,  the  file  is  immersed  in  some  adhesive  substance,  such  as  ale- 
grounds,  in  which  salt  has  been  dissolved  ;  this  protects  the  teeth  from  the  direct  action 
of  the  fire;  it  is  then  immersed  perpendicularly  in  water;  cleansed  by  finishing. 

RATAFIA,  is  the  generic  name,  in  France,  of  liqueurs  compounded  with  alcohol, 
sugar,  and  the  odoriferous  or  flavouring  principles  of  vegetables.  Bruised  cherries  with 
their  stones  are  infused  in  spirit  of  wine  to  make  the  ratafia  of  Grenoble  de  Teysskre. 
The  liquor  being  boiled  and  filtered,  is  flavoured,  when  cold,  with  spirit  of  noyeau,  made 
by  distilling  water  off  the  bruised  bitter  kernels  of  apricots,  and  mixing  it  with  alcohoL 
Syrup  of  bay  laurel  and  galango  are  also  added.     See  Liqueurs. 

RAZORS.  151.  Elliot,  J.  Towiihead  Street,  Sheffield  —  Manufacturer.  Pattern 
razors  manufactured  of  the  best  steel,  exhibited  for  temper,  design  and  workmanship. 

Frame  back  razor,  ground  exceedingly  thin  and  cannot  require  to  be  again  ground, 
thus  retaining  a  fine  and  durable  edge,  and  increasing  greatly  the  ease  of  shaving.  The 
gold,  silver,  steel,  german-silver  or  brass  backs,  form  an  elegant  contrast  to  the  blade, 
and  enhance  the  beauty  of  appearance,  as  well  as  afford  more  opportunity  for  originality 
of  design  and  skill  in  execution. 

Two  workmen  are  always  engaged  in  razor-making.  The  rod  of  steel  of  which  they 
are  made  is  about  half  an  inch  in  breadth,  and  of  sufficient  thickness  to  form  the  back. 
The  stake  upon  which  they  are  forged  is  rounded  on  both  sides  of  the  tops,  which  is 
instrumental  in  thinning  the  edge,  and  much  facilitates  the  operation  of  grinding.  The 
blades  are  then  hardened  and  tempered  in  the  ordinary  way,  with  the  exception  that 


RED  LIQUOR. 


639 


they  are  placed  on  their  back  on  an  iron  plate,  and  the  moment  they  assume  a  straw 
colour  of  a  deep  shade  they  are  removed. 

The  grinding  follows,  on  a  stone  revolving  in  water ;  then  glazing  on  a  wooden  disc. 
The  fine  polish  is  given  by  a  wooden  wheel,  having  its  circumference  covered  with  buff 
leather,  which  is  covered  with  crocus.  The  ornamentation  of  the  blade  by  etching  with 
acid  and  gilding,  if  such  is  required,  is  the  last  process. 

REALGAR,  Red  Orpiment  {Arsenic  rouge  sulpkure,  Fr. ;  Rothes  schwe/elarsenik. 
Germ.)  This  ore  occurs  in  primitive  mountains,  associated  sometimes  with  native 
arsenic  under  the  form  ot  veins,  efflorescences,  very  rarely  crystalline ;  as  also  in  volcanic 
districts;  for  example,  at  Solfaterra  near  Naples ;  or  sublimed  in  the  shape  of  stalactites, 
in  the  rents  and  craters  of  Etna,  Vesuvius,  and  other  volcanoes.  Its  spec.  grav.  varies 
from  3-3  to  3*6.  It  has  a  fine  scarlet  colour  in  mass,  but  orange  red  in  powder,  whereby 
it  is  distinguishable  from  cinnabar.  It  is  soft,  sectile,  readily  scratched  by' the* nail; 
its  fracture  is  vitreous  and  conchoidal.  It  volatilizes  easily  before  the  blowpipe,  emitting 
the  garlic  smell  of  arsenic,  along  with  that  of  burning  sulphur.  It  consists  of  arsenic  10, 
sulphur  30  in  100  parts.  It  is  employed  sometimes  as  a  pigment.  Factitious  orpiment 
IS  made  by  distilling  in  an  earthen  retort  a  mixture  of  sulphur  and  arsenic,  of  orpiment 
and  sulphur,  or  of  arsenious  acid,  sulphur  and  charcoal.  It  has  not  the  rich  colour  of 
the  native  pigment,  and  is  much  more  poisonous  ;  since,  like  factitious  orpiment,  it  always 
contains  more  or  less  arsenious  acid. 

RECTIFICATION,  is  a  second  distillation  of  alcoholic  liquors,  to  free  them  from 
whatever  impurities  may  have  passed  over  in  the  first. 

RED  LIQUOR,  is  a  crude  acetate  of  alumina,  employed  in  calico-printing,  and  pre- 
pared from  pyrolignous  acid ;  which  see,  and  Calico  Printing. 

At  first  sight  it  would  appear  that  alumina  is  the  intermediate  fixing  agent.  The 
pyrolignite  of  alumina,  by  its  easy  decomposition  into  acetic  acid  and  alumina,  would  be 
the  one  preferred ;  but  practice  has  shown  that  a  sulpho-acetate  of  alumina  gives  the 
best  results,  and  which  is  composed  as  follows : — 

+  SO3, 

-f  2  C4  H,  O,, 

and  prepared  by  mixing  together 

453  lbs.  of  ammoniacal  alum. 

379  lbs.  of  acetate  of  lead,  or  315  lbs.  of  pyrolignite  of  lead. 
1182  lbs.  of  water. 


AlaO, 


or, 


383  lbs.  of  sulphate  of  alumina. 

379  lbs.  of  acetate  of  lead,  or  315  lbs.  of  pyrolignite  of  lead. 
1132  lbs.  of  water. 


or, 


or. 


463  lbs.  of  alum,  and  a  quantity  of  solution  of  pyrolignite  of  lime,  amounting  to 
158  IKq. 


383  lbs.  of  sulphate  of  alumina,  with  the  same  amount  of  pyrolignite  of  lime. 


These  substances  are  well  stiired  together  for  several  hours,  complete  double  decom- 
position ensues,  sulphate  of  lead  is  deposited,  and  sulpho-acetate  of  alumina  remains  in 
solution  with  one  equivalent  of  sulphate  of  ammonia,  proceeding  from  the  ammoniacal 
alum  employed,  as  only  two  equivalents  of  sulphuric  acid  are  removed  from  the  four 
which  alum  contains 

But  as  sulphate  of  ammonia  is  of  no  use  in  the  process  of  mordanting  cloth,  and  as  it 
may  be  considered  as  increasing  the  price  of  the  articles  to  the  manufacturer,  a  very 
intelligent  firm  had  the  good  idea  of  replacing  ammoniacal  alum  by  sulphate  of 
alumina,  thus  not  only  rendering  the  liquor  cheaper,  but  their  liquor  marks  the 
same  strength  as  that  of  other  manufacturers, — namely,  sp.  gr.  1  085,  or  17  Twaddle. 
The  red  mordant  D  of  this  firm  contains  a  larger  amount  of  useful  agents  under  the 
same  bulk  of  fluid. 

The  following  analyses  clearly  show  this  point :  (see  next  page)— 
From  these  results  it  is  easy  to  perceive  that  the  composition  of  red  liquors  varies  a 
great  deal  m  ]JIanchester,  and  that  it  is  of  importance  to  our  extensive  calico-printing 
firms  to  inouire  more  than  they  at  present  do  into  the  composition  of  their  red  mor- 
dants. By  doing  so  we  have  no  doubt  they  will  arrive  at  two  ends,— viz.,  account  better 
than  they  do  for  the  superiority  of  some  prints  over  others,  and  discover  why  certain 
persons  always  believe  the  peculiar  red  mordant  they  employ  the  best,  and  if  results  do 
not  come  up,  attribute  failures  to  the  madder,  «fec 

I  may  mention  here  a  fraud  or  two  which  has  been  discovered  in  the  pyrolignite  of 
iron,  or  black  Uquor,  employed  by  calico  printers  and  dyers  for  obtaining  black  erev 

8  Z  2  '&     ». 


.  — ^ 

III 


i  i 


I , , 


I-  ■: .  ' 


640 


REED. 

OompoHtion  of  Four  MordanU  per  Gallon. 


8alw(«Deet. 


Alumina         -       • 
Sulphuric  acid 
Acetic  acid     • 
Aminoaia  and  water 


Formnln. 

ALs  O3  8O3  QC.  Hs  03  +NH3 
8O3  UO. 


Mordant  A. 


irrains. 

leso-o 

1642-5 
•674-1 


oz. 

8 

6 

1 
1 


18 

20 

807 

936 


Mordant  B. 


ffraiiis. 
1 830-0 
2800-0 
3670-0 
■9100 


oz. 

4 

6 

8 

3 


gr*- 
1« 

178 
70 
36 


Fom»n'a. 
ALiO:.Q803   C4 

HsOa  +  NHsSOs 
HO. 


Mordant  C. 


uns. 
IS39-0 
SOI 7-0 

1281-7 
•6531 


oz. 

2 
1 


gn. 
865 
395 
40< 
915 


Formula, 

Ala  O3  +  8O3  QC« 

H3O3. 


Mordant  D. 


gmint, 
«!«4-4 
16616 
3679-9 


oz.  irr*. 

4  416 

3  333 

8  179 


mar^n,  chocolate,  <fea    It  is  but  just  to  state,  that  this  fraud  is  mainly  owing  to  the 

i^li  4  p""ar"''"  '^'°"'''"'  "^"  '^^""'  "^'''''^  **  ^  ^^"^^  p"««  ^^--'^y 

r.Ji'lfP""'^"''*''  '^^^r^  ''''^''  ^"^^  ^^*^^  ^'q"°"  a^«  """"ate  or  sulphate  of  iron  in 
proportions  varying  from  10  to  30  per  cent.  To  detect  them  the  black  liiuo;  8 
treated  by  carbonate  of  soda,  which,  on  throwing  down   the  oxide  of  iron  SuceJ 

trtfr  "h""  '"^  '""^^Y'  "^.  ^"^^  ^''^  "'^«^«  •«  '^^^  thrown  up^rn'^.  fiUer 
The   liquor,  when    evaporated   to   dryness,  and    calcined,  to  destroy  organic   matter 

nUracid'f  wh;tfr^""  l-.ing /i^solved,  gives,  after  being  re^nderfS  aciHth 
nitric  acid,  a  white  curdy  precipitate  with  nitrate  of  silver,  and  a  white  pulverulent 

''^Frn  "-""^V"  ^^  ^n7'^  '^  "^^°"^^^  "^  ^"^P'^^'^«  *••«  P^«^"t  in  the  llqEor. 

KJi.KD,   is   the  well-known   implement   of  the  weaver,   made  of  paralfel   slips   of 

ff  ,     ""■    '^^'^''  ""^^Y.  ^^"^'-      ^    thorough    knowledge  of   the    adaption  of  yarn 

nL/'TI-  f^%''^u'^"^"^'^^^  ''"y  ^''^^'^  ^^^^^^  of  reed,  constitutes  one  of  the 
principal  objects  of  the  manufacturer  of  cloths;  as  upon  this  depends  entirely  the 
appearance,  and  in  a  great  degree  the  durability,  of  the  cloth  when  finished.  The 
ILuinl  P^";?"^;"'"-  this  properly  ,s  known  by  the  names  of  examining,  setting,  or 
sleying,  which  are  used  indiscriminately,  and   mean    exactly   the   same   thin?.      The 

r„l  .'ZT  ''^.u"'''  ^^'""V  P'""?  ^^^^^'  '^*  ^  ^^^  '"«»»^«  apa'-t,  «nd  they  are  of 
fnl  T^  "    \  *'  ^  ^'^'u '.^  y*'?  ^"^  ^  ^"^'  ^^••'  "^c-     The  division  of  the  yard  being 

into  halves,  quarters,  eighths,  and  sixteenths;  the  breadth  of  a  web  is  generally  ex" 
pressed  by  a  vulgar  fraction,  as  |,  4,  5,  ^.  and  the  subdivisions  by  the  eighths  or  six- 
teenths,  or  nails,  as  they  are  usually  called,  as  1, 1,  U  &c.,  or  11  JS    1  9    &c      In 

r^^I^f;'v'  '^''i' K^  f  "'.""S''^  P"''  betweenShelongitudinalV'i'ecVs'oT^'ibsof  the 
reed,  are  expressed  by  hundreds,  porters,  and  splits.  The  porter  is  20  splits,  or  1th  of 
a  hundred.  * 

riJjnn^^nr'fhi''^  7^  ^l^'^^'^  ^  ^'^^'^"^  T*^^  ''  ^^^J^^^^'  ^"^h  as  to  the  measure  and  di- 
ns  ons  of  the  reed.     The  Manchester  and  Bolton  reeds  are  counted  bv  the  number  of 

5?n?^''\'''H''7K^''  '^"■'  called,  dents,  contained  in  24i  inches  of  the  reed.  These 
ients,  instead  of  being  arranged  in  hundreds,  porters,  and  splits,  as  in  Scotland  are  cal- 
eulated  by  what  is  there  termed  hares  or  bears,  each  containing  20  dents  or  the  same 
number  as  the  porter  m  the  Scotch  reeds.  The  Cheshire  or  StSckport  reeds  againTe! 
ceive  their  designation  from  the  number  of  ends  or  threads  contained  in  one  inT'two 
llfZZI-  f^'^'f  i"-  ^^f  y '^^'^  th^.t  beino:  the  almost  universal  number  in  eve  y  sfic^s 
and  description  of  plain  cloth,  according  to  the  modern  practice  of  weaving,  and  aKr 
a  great  proportion  of  fanciful  articles.  c«ving,  anu  aiso  lor 

The  number  of  threads  in  the  warp  of  a  web  is  generallv  ascertained  with  considerable 
r,Tr!rd\'  "^T'  '^.\'T^^  n^a^nifying  glass,  fitted  into'a  socket  of  bm  s^mSer  wWch 
^•siWe  1  Z  'T^^""^^  '"  '^'  ^"r  P^^*"  ""^  '^'  standard.  The  number  of  ihTeads 
Tfthereed     Vn^^^^^  number  of  threads  in  the  standard  measure 

whtl  th!  ;i«cT  "k^.:"a^.°^^^41?  ^V^  sometimes  four  perforations,  over  any  one  of 
.^thereL^w.11™^^^  tV^'^fu*  J^?  ^'''  P^'-^^'-^tion  is  f  of  an  inch  in  diameter,  and 
{Mini  ?h!  7^",  ^^"r^^  i*"  *^^  Stockport  mode  of  counting;    that  is  to  say,  for  ascer- 

Je;S  beit  rth'Lf,  'f'J'  '^''^fKP".>;^  '  ^^^  '^'-^^  '^  -^^P^-^  ^-'^e  Holland 
reed,  being  ._J_jth  part  of  40  inches;  the  third  is     i    th  of  37  inches,  and  is  adapted  foi 

the  now  almost  universal  construction  of  Scotch  reeds;  and  the  fourth,  being  ^-th  of 

ute"mea%u^e"''^^^^^^  ^''"'^  ""'"o^T^V  Every  thread  appearing  In  thesVr'espec 

live   measures    of  course    represents   200   threads,  or    J 00   splits    in    the   standnnl 

S'Vven"tfter  \h?clS^  ^'  T  '^'^'^  '"'^^  '^  ^^'^''^'^^  ^^^  cons!SeUTe"'pr^ 
iound  oT  dvfwork  Bv  .^V""^t'"^^^^  '^P'^^'^  wettins^s,  either  at  the  bleach  ng. 
ground  oi  (l>e.work.  By  counting  the  other  way,  the  proportion  which  the  woof  bear, 
to  the  warp  is  also  known  and  this  forms  the  chief  use  of  the  slass  to  the  maTfacl^re^ 
o?  theTeTd:"^'  ^'''^'''  """'''  °^  ^^°°^  ""''  P^^"^«"^^y  ^^^"^"^^«d  with  the  exaclmei^" 


REFINING  OF  GOLD  AND  SILVER. 


541 


Comparative  Table  of  37-inch  reeds,  being  the  standard  used  throughout  Europe,  for 
linens,  with  the  Lancashire  and  Cheshire  reeds,  and  the  foreign  reeds  used  for  holland 
and  cambric. 


Scotch. 

Lancashire. 

Cheshire. 

Dutch  holland. 

French  cambric. 

600 

20 

34 

550 

653 

700 

24 

38 

650 

761 

800 

26 

44 

740 

870 

900 

30 

50 

832 

979 

1000 

34 

54 

925 

1089 

1100 

36 

60 

1014 

1197 

2200 

40 

64 

1110 

1300 

1300 

42 

70 

1202 

1414 

1400 

46 

76 

1295 

1464 

1500 

50 

80 

1387 

1602 

1600 

52 

86 

1480 

1752 

1700 

56 

92 

1571 

1820 

1800 

58 

96 

1665 

1958 

1900 

62 

104 

1757 

2067 

2000 

66 

110 

1850 

2176 

In  the  above  table,  the  37-inch  is  placed  first.  It  is  called  Scotch,  net  because  it 
cither  originated  or  is  exclusively  used  in  that  country.  It  is  the  general  linen  reed  of 
all  Europe ;  but  in  Scotland  it  has  also  been  adopted  as  the  regulator  of  her  cotton  manuo 
factures, 

REFINING  OF  GOLD  AND  SILVER;  called  also  Parting.  (JJinage  d'argent. 
Depart,  Ft.  ;  Scheidung  in  die  quart.  Germ.)  For  several  uses  in  the  arts,  these  pre- 
cious metals  are  required  in  an  absolutely  pure  state,  in  which  alone  they  possess  their 
malleability  and  peculiar  properties  in  the  most  eminent  degree.  Thus,  for  example, 
neither  gold  nor  silver  leaf  can  be  made  of  the  requisite  fineness,  if  the  metals  contain 
the  smallest  portion  of  copper  alloy.  Till  within  these  ten  or  twelve  years,  the  parting 
of  silver  from  gold  ^yas  effected  everywhere  by  nitric  acid;  it  is  still  done  so  in  all  the 
establishments  of  this  country,  except  the  Royal  Mint ;  and  in  the  small  refining-houses 
abroad.  The  following  appaiatus  may  be  advantageously  employed  in  this  operation.  It 
will  serve  the  double  purpose  of  manufacturing  nitric  acid  of  the  utmost  purity,  and  of 
separating  silver  from  gold  by  its  means. 


1.  On  procuring  mine  acid  for  parting.-'^  is  a  platinum  retort  or  alembic ;  b  is 
Us  capital,  terminating  above  in  a  tubulure,  to  which  a  kneed  tube  of  platinum, 
about  2  feet  long,  is  adapted;  c  is  the  tubulure  of  the  retort,  for  supplying  acid 
diinng  the  process,  and  for  inspecting  its  progress.  It  is  furnished  with  a  lid  ground 
air-tight,  which  may  be  secured  in  its  place  by  a  weight,  c  is  a  stoneware  pipe,  about 
two  inches  diameter,  and  several  feet  long,  according  to  the  locality  in  which  the 
operation  is  to  be  carried  on.  It  is  made  in  lengths  fitted  to  one  another,  and  secured 
at  the  joints  with  loam-lute.  The  one  bend  "of  this  earthenware  hard  salt-glazed 
pipe  is  adapted  to  receive  the  platinum  tube,  and  the  other  bend  is  inserted  into  a  tubu- 
lure in  the  top  of  the  stoneware  drum/.     The  (.pening  /,  /,  in  the  middle  oC  the  lop  of  /,  is 


542 


REFINING  OF  GOLD  AND  SILVER. 


REFINING  OF  GOLD  AND  SILVER. 


543 


t- 


■  f 


for  inspecting  the  progress  of  the  condensation  of  acid;  and  the  third  tubulure  tenni 
nates  in  a  prolonged  pipe  *,  i,  consisting  of  several  pieces,  each  of  which  enters  from  above 
conically  into  the  one  below.  The  joinings  of  the  upper  pieces  need  not  be  tightjy  luted, 
as  it  is  desirable  that  some  atmospherical  oxygen  should  enter,  to  convert  the  relatively 
light  nitrous  gas  into  nitrous  or  nitric  acid  vapor,  which  when  supplied  with  moisture  will 
condense  and  fall  down  in  a  liquid  state.  To  supply  this  moisture  in  the  most  diflusivc 
form,  the  upright  stoneware  pipes  t,  t,  /,  /,  (at  least  3  inches  diameter,  and  12  feet  high), 
should  be  obstructed  partially  with  flint  nodules,  or  with  siiicious  pebbles;  and  water 
should  be  allowed  to  trickle  upon  the  top  pebble  from  a  cistern  placed  above.  Care  must 
be  taken  to  let  the  water  drop  so  slowly  as  merely  to  preserve  the  pebbles  in  a  state  of 
humidity.  A  is  a  stopcock,  of  glass  or  stoneware,  for  drawing  off  the  acid  from  the  cis- 
tern/, k  is  a  section  of  a  small  air-furnace,  covered  in  at  top  with  an  iron  ring,  on  which 
the  flat  iron  ring  of  the  platinum  frame  rests. 

g,  g,  is  a  tub  in  which  the  stoneware  cistern  stands,  surrounded  with  water,  kept  con- 
stantly as  cold  as  possible  by  passing  a  stream  through  it ;  the  spring  water  entering  by  a 
pipe  that  dips  near  to  the  bottom,  and  the  hot  water  escajung  at  the  upper  edge. 

With  the  above  apparatus,  the  manufacture  of  pure  niiric  acid  is  comparatively  easy 
and  economical.  Into  the  alembic  a,  100  pounds  (or  thereby)  of  pure  nitre,  coarsely 
bruised  if  the  crystals  be  large,  are  to  be  put ;  the  capital  is  then  to  be  adapted,  and  the 
platinum  tube  (the  only  moveable  one)  luted  into  its  place.  Twenty  pounds  of  strong 
sulphuric  acid  are  now  to  be  introduced  by  the  tubulure  c,  and  then  its  lid  must  be  put 
on.  No  heat  must  yet  be  applied  to  the  alembic.  In  about  an  hour,  another  ten  pounds 
of  acid  may  be  poured  in,  and  so  every  hour,  till  60  pounds  of  acid  have  been  added.  A 
few  hours  after  the  affusion  of  the  last  portion  of  acid,  a  slight  fire  may  be  kindled  in  the 
furnace  k. 

By  judicious  regulation  of  the  heat,  the  whole  acid  may  be  drawn  off  in  24  hours ;  its 
final  expulsion  being  aided  by  the  dexterous  introduction  of  a  quart  or  two  of  boiling 
water,  in  small  successive  portions,  by  the  tubulure  c,  whose  lid  must  be  instantly  shut 
after  every  inspersion.  The  most  convenient  strength  of  acid  for  the  parting  process,  is 
when  its  specific  gravity  is  about  1-320,  or  when  a  vessel  that  contains  16  ounces  of  pure 
water,  will  contain  21 1  of  the  aquafortis.  To  this  strength  it  should  be  brought  very  ex- 
actly by  the  aid  of  a  hydrometer. 

Its  purity  is  easily  ascertained  by  letting  fall  into  it  a  few  drops  of  solution  of  silver; 
and  if  no  perceptible  milkiness  ensues,  it  may  be  accounted  good.  Should  a  white 
cloud  appear,  a  few  particles  of  silver  may  be  introduced,  to  separate  whatever  muriatic 
acid  may  be  present,  in  the  form  of  chloride  of  silver.  Though  a  minute  quantity  of 
sulphuric  acid  should  exist  in  the  nitric,  it  will  be  of  no  consequence  in  the  operation  of 
parting. 

2.  On  parting  by  the  nitric  acid,  called  by  the  Mexicans,  "  II  apartado/'— The  principle 
on  which  this  process  is  founded,  is  the  fact  of  silver  being  soluble  in  nitric  acid,  while 
gold  is  insoluble  in  that  menstruum.  If  the  proportion  of  gold  to  that  of  silver  be  greater 
than  one  to  two,  then  the  particles  of  the  former  metal  so  protect  or  envelop  those  of  the 
latter,  that  the  nitric  acid,  even  at  a  boiling  heat,  remains  quite  inactive  on  the  alloy.  II 
is  indispensable,  therefore,  that  the  weight  of  the  silver  be  at  least  double  that  of  the  gold. 
100  pounds  of  silver  take  38  pounds  of  nitric  acid,  of  specific  gravity  1-320,  for  oxydize. 
ment,  and  111  for  solution  of  the  oxyde ;  being  together  149 ;  but  the  refiner  often  con- 
sumes, in  acid  of  the  above  strength,  more  than  double  the  weight  of  silver,  which  shows 
great  waste,  owing  to  the  imperfect  means  of  condensation  employed  for  recovering  the 
vapors  of  the  boiling  and  very  volatile  acid. 

By  the  apparatus  above  delineated,  the  38  pounds  of  acid  expended  in  oxydizing  the  silver, 
become  nitrous  gas  in  the  first  place,  and  are  afterwards  reconverted  in  a  great  measure 
into  nitric  acid  by  absorption  of  atmospherical  oxygen  ;  so  that  not  one  fifth  need  be  lost, 
under  good  management.  As  the  acid  must  be  boiled  on  the  granulated  garble,  or  alloy, 
to  etiect  the  solution  of  the  silver,  by  proper  arrangements  the  vapors  may  be  entirely  con- 
densed, and  nearly  the  whole  acid  be  recovered,  except  the  111  parts  indispensable  to  con- 
stitute nitrate  of  silver.  Hence,  with  economical  management,  120  pounds  of  such  acid 
may  be  assigned  as  adequate  to  dissolve  100  of  silver  associated  with  50  of  gold. 

It  must  here  be  particularly  observed,  that  100  pounds  of  copper  require  130  pounds  of 
the  above  acid  for  oxydizement ;  and  390  for  solution  of  the  oxyde ;  being  520  pounds  in 
whole,  of  which  less  than  |  part  could  be  recovered  by  the  above  apparatus.  It  is  there- 
fore manifest  that  it  is  desirable  to  employ  silver  pretty  well  freed  from  copper  by  a  pre- 
vious process ;  and  always,  if  practicable,  a  silver  containing  some  gold. 

These  data  being  assumed  as  the  bases  of  the  parting  operation,  60  pounds  of  gold  and 
silver  alloy  or  garble  finely  granulated,  contain  ins:  not  less  than  40  pounds  of  silver,  are  to 
be  introduced  into  the  ten-gallon  alembic  of  platinum,  fig.  931,  and  80  pounds  of  nitric 
acid,  of  1-320,  is  to  be  poured  over  the  alloy ;  a  quantity  which  will  measure  6  gallont 
Imperial.    As  for  the  bulk  of  the  alloy,  it  is  considerably  less  than  half  a  gallon.    Abun 


dait<;e  of  space  therefore  remains  in  the  alembic  for  effervescence  and  eballition,  provided 
the  fire  be  rightly  tempered. 

Bv  the  extent  of  stoneware  conducting  pipe  e,  which  should  not  be  less  than  40  feet,  by 
the  cfimensions  and  coldness  of  the  cistern/,  and  by  the  regenerating  influence  of  the  ver- 
cical  aerial  pipe  filled  with  moist  pebbles  i,  i,  it  is  clear,  that  out  of  the  80  pounds  of  ni- 
tric acid,  specific  gravity  1-320,  introduced  at  first,  from  20  to  30  will  be  recovered. 

Whenever  the  effervescence  and  disengagement  of  nitrous  red  fumes  no  longer  appear 
on  opening  the  orifice  c,  the  fire  must  be  removed,  and  the  vessel  may  be  cooled  by  the 
application  of  moist  cloths.  The  alembic  may  be  then  disengaged  from  the  platinum  tube, 
and  lifted  out  of  its  seat.  Its  liquid  contents  must  be  cautiously  decanted  off,  through  the 
orifice  c,  into  a  tub  nearly  filled  with  soft  water.  On  the  heavy  pulverulent  gold  which 
remains  in  the  vessel,  some  more  acid  should  be  boiled,  to  carry  off  any  residuary  silver. 
This  metallic  powder,  after  being  well  washed  with  water,  is  to  be  dried,  fused  along  with 
a  little  nitre  or  borax,  and  cast  into  ingots. 

Plates  of  copper  being  immersed  in  the  nitric  solution  contained  in  wooden  or  stone- 
ware cisterns,  will  throw  metallic  silver  down,  while  a  solution  of  nitrate  of  copper, 
called  blue  water,  will  float  above.  The  pasty  silver  precipitate  is  to  be  freed  from  the 
nitrate  of  copper,  first,  by  washing  with  soft  water,  and  next,  by  strong  hydraulic  pressure 
in  cast  iron  cylinders.  The  condensed  mass,  when  now  melted  in  a  crucible  along  with 
a  little  nitre  and  borax,  is  fine  silver. 

The  above  apparatus  has  the  further  advantage  of  enabling  the  operator  to  recover  a 
great  portion  of  his  nitric  acid,  by  evaporating  the  blue  water  to  a  state  approaching  to 
dryness,  with  the  orifices  at  c,  and  at  the  top  of  the  capital,  open.  In  the  progress  of 
this  evaporation,  nothing  but  aqueous  vapor  escapes.  Whenever  the  whole  liquid  is 
dissipated,  the  pipe  d  is  to  be  re-adjusted,  and  the  lid  applied  closely  to  c.  The  heat 
bein;;  now  continued,  and  gradually  increased,  the  whole  nitric  acid  will  be  expelled 
from  the  copper  oxyde,  which  will  remain  in  a  black  mass  at  the  bottom  of  the  alembic. 
The  contrivance  for  letting  water  trickle  upon  the  pebbles,  must  be  carefully  kept  in 
play,  otherwise  much  of  the  evolved  acid  would  be  dissipated  in  nitrous  fumes.  With 
due  attention  to  the  regenerative  plan,  a  great  part  of  the  acid  may  be  recovered,  at  no 
expense  but  that  of  a  little  fuel. 

The  black  oxyde  of  copper  thus  obtained,  is  an  economical  form  of  employing  thai 
metal  for  the  production  of  the  sulphate ;  100  pounds  of  it,  with  122|  of  sulphuric  acid 
diluted  with  water,  produce  312$  pounds  of  crystallized  sulphate  of  copper.  A  leaden 
boiler  is  best  adapted  for  that  operation.  100  pounds  of  silver  are  precipitable  from  its 
solution  in  nitric  acid,  by  29  of  copper.  If  more  be  needed,  it  is  a  proof  that  a  wasteful 
excess  of  acid  has  existed  in  the  solution. 

In  parting  by  nitric  acid,  the  gold  generally  retains  a  little  silver ;  as  is  proved  by 
the  cloud  of  chloride  of  silver  which  it  affords,  at  the  end  of  some  hours,  when  dissolved 
in  aqua  regia.  And  on  the  other  hand,  the  silver  retains  a  little  gold.  These  facts 
indr.ced  M.  Dize,  when  he  was  inspector  of  the  French  mint,  to  adopt  some  other  pro- 
cess, wnich  would  give  more  accurate  analytical  results ;  and  after  numerous  experi- 
ments, he  ascertained  that  sulphuric  acid  presented  great  advantages  in  this  point  of 
view,  since  with  it  he  succeeded  in  detecting,  in  silver,  quantities  of  gold  which  had 
eluded  the  other  plan  of  parting.  The  suggestion  of  M.  Dize  has  been  since  univer- 
sally adopted  in  France.  M.  Costell,  about  nine  or  ten  years  ago,  erected  in  Pomeroy- 
street.  Old  Kent-road,  a  laboratory  upon  the  French  plan,  for  parting  by  sulphurie 
acid ;  but  he  was  not  successful  in  his  enterprise ;  and  since  he  relinquished  the  business, 
Mr.  Matheson  introduced  the  same  system  into  our  Royal  Mint,  under  the  management 
of  M.  Costell's  French  operatives.  In  the  Parisian  refineries,  gold,  to  the  amount  of 
one  thousandth  part  of  the  weight,  has  been  extracted  from  all  the  silver  which  had  been 
previously  parted  by  the  nitric  acid  process ;  being  3500  francs  in  value  upon  every  thou- 
sand kilogrammes  of  silver. 

I  shall  give  first  a  general  outline  of  the  method  of  parting  by  sulphuric  acid,  and  then 
describe  its  details  as  I  have  lately  seen  them  executed  upon  a  magnificent  scale  in  an 
establishment  near  Paris. 

The  most  suitable  alloy  for  refining  gold,  by  the  sulphuric  acid  process,  is  the  compound 
of  gold,  silver,  and  copper,  having  a  standard  quality,  by  the  cupel,  of  from  900  to  950 
milliemes,  and  containing  one  fifth  of  its  weight  of  gold.  The  best  proportions  of  the 
three  metals  are  the  following :— silver,  725 ;  gold,  200  ;  copper,  75 ;  =  1000.  It  has 
been  found  that  alloys  which  contain  more  copper,  aflibrd  solutions  that  hold  some 
anhydrous  sulphate  of  that  metal  in  solution,  which  prevents  the  gold  from  being  readily 
separated ;  and  that  alloys  containing  more  gold,  are  not  acted  on  easily  by  the  sulphuric 
acid.  The  refiner  ought,  therefore,  when  at  all  convenient,  to  reduce  the  alloys  that 
he  has  to  treat  to  the  above-stated  proportions.  He  may  effect  this  purpose  either  by 
fusing  the  coarser  alloys  with  nitre  in  a  crucible,  or  by  adding  finer  alloy,  or  even  fine 
silver,  or  finally,  by  subjecting  the  coarser  alloys  to  a  previous  cupellation  with  lead  on 


544 


REFINING  OF  GOLD  AND  SILVER. 


I  I  It     I 


[|   I! 


: 


'W.i 


,:f  •  •  i 


t.f^l  Tl\  ^  ^""^  *'''  ^u'^^'  ]'""'''"'  '^^'''^  contains  Jead  and  other  easily  ox> 
iizable  metals  besides  copper,  the  refiner  uugnt  always  to  avoid  treating  mem  oy  siJ 
phuric  acid ;  and  should  separate,  first  of  all,  these  foreign  metals  by  the  agency  of  nitre 
if  they  exist  m  minute  quantity;  but  if  in  larger,  he  should  have  Tecours?  to  the  cuDeL 

be  refined'.'"''^'  '^'"^'''  ^  ^'"'"^  ^'""^  '^'  ^"^^^'""^  preparation  of  the  aUoytc 

nf^l^..^  •""^.^^^^.^^''^l^'^^P^'''"'^^'^  P""^''P^^  P*"«^^»  refiners  are  in  the  halit 

^^InW^r"^/*""'^  '^^\^r^^^  °^  '"^P^""^  ^"^'  *^  ""'^^^  ^^  «^^«i"  *  clear  solution  of 
sulphate  of  silver,  which  does  not  loo  suddenly  concrete  on  eooline,  so  as  to  ob^ruct  its 
discharge  from  the  alembic  by  decantation.  A  small  increase  in  the  quantity  of  copper! 
calls  for  a  considerable  increase  in  the  quantitv  of  acid.  ^       copper, 

Generally  speaking,  one  half  of  the  sulphuric  acid  strictly  required  for  convertine  the 
silver  and  copper  into  sulphates,  is  decomposed  into  sulphurous  acid,  which  is  lost  to  the 
manufacturer,  unless  he  has  recourse  to  the  agency  of  nitrous  acid. 
_  The  process  for  silver  containing  but  little  gold,  consists  of  five  different  opera- 

1.  Upon  several  furnaces,  one  foot  in  diameter,  egg-shaped  alembics  of  platinum  are 
mounted,  into  each  of  which  are  put  3  kilogrammes  (8  lbs.  troy)  of  the  granulated 
•liver,  containing  a  few  grains  of  gold  per  pound,  and  6  kilogrammes  of  concentrated 
sulphuric  acid.  The  alembics  are  covered  with  conical  capitals,  ending  in  bent  tubes 
Which  conduct  the  acid  vapors  into  lead  pipes  of  condensation;  and  the  furnaces  are 
erected  under  a  proper  hood.  As  the  cold  acid  is  inoperative,  it  must  be  set  a  boilin-. 
at  which  temperature  it  gives  up  one  atom  of  its  oxygen  to  the  metal,  and  is  transforme^d 
into  sulphurous  acid,  which  escapes  in  a  gaseous  state.  Some  of  the  undecomposed  sul- 
phuric  acid  immediately  combines  with  the  oxyde  into  a  sulphate,  which  subsides,  in  the 
state  of  a  crystalline  powder,  to  the  bottom  of  the  vessel.  The  solution  goes  on  vi-or- 
ously,  with  a  copious  disengagement  of  sulphurous  acid  gas,  only  during  the  two  or  three 
first  hours ;  after  which  it  proceeds  slowly,  and  is  not  completed  till  after  a  digestion  of 
nearly  twelve  hours  more.  During  the  ebullition  a  considerable  quantity  of  sulphuric 
acid  vapor  escapes  along  with  the  sulphurous  acid  gas;  the  former  of  which  is  readily 
condensed  in  a  large  leaden  receiver  immersed  in  a  cistern  of  cold  water,  if  need  be  It 
has  been  proposed  to  condense  the  sulphurous  acid,  by  leading  it  over  extensive  surfaces 
of  Iime-pap,  as  in  the  coal-gas  purifiers. 

2.  When  the  whole  silver  has  been  converted  into  sulphate,  this  is  to  be  emptied  out 

?i  7^!ir,"u    i"*°.  ^^!5^  contamedin  a  round-bottomed  receiver  lined  with  lead,  and 

nflu  •  /k  r^''^'^  ""^u^^  '^^"^^"'I  "^^'^^  ^'^^  ^^'  *°  20°  Baume.  The  small  portion 
ol  gold  m  the  form  of  a  brown  powder,  which  remains  undissolved,  having  been  allowed 
to  settle  to  the  bottom,  the  supernatant  solution  of  silver  is  to  be  decanted  carefully  off 
into  a  leaden  cistern,  and  the  powder  being  repeatedly  edulcorated  with  ^ater  the  wash- 
ings are  to  be  added  to  it.  The  silver  is  now  to  be  precipitated  by  plunging  plates  of 
copper  m  the  solution,  and  the  magma  which  falls  is  to  be  well  washed,  and  freed  from 
the  residuary  particles  of  sulphate  of  copper  by  powerful  compression. 

3.  The  silver,  precipitated  and  dried  as  above  described,  is  melted  in  a  crucible  and 
east  into  an  ingot.  * 

.,  ^V'T^^  ^^^^  PO^<Jer  is  also  dried  and  cast  into  an  ingot,  a  little  nitre  being  added  in 
the  lusion,  to  oxydize  and  separate  any  minute  particles  of  copper  that  may  perchance 
have  been  protected  from  the  solvent  action  of  the  acid.  P^rcnanct: 

5.  As  the  sulphate  of  copper  is  of  considerable  value,  its  solution  is  to  be  neutralized, 
evaporated  in  leaden  pans  to  a  proper  strength,  and  set  aside  to  crystallize  in  leaden 
^f/J"^  •  J^  ^^"°T  throughout  France  consume  an  immense  quantity  of  this  salt. 
They  sprinkle  a  weak  solulion  of  it  (at  2»  or  3<»  Baume)  over  their  grain  before  sowing 
It,  in  order  to  protect  it  against  the  ravages  of  birds  and  insects. 

The  pure  gold,  at  the  instant  of  its  separation  from  the  alloy  by  the  action  of  sulphuric 

fni„«„!i"V''  V-^^  ^"^  ^'^^''^'  ^"'^  ^y'""  ^"  ^'*»««  *^°"t«<^*  ^»th  the  platinum,  under  the 
influence  of  a  boiling  menstruum,  which  brightens  the  surfaces  of  the  two  Petals,  and 

«tw1«l  v^cnl/'^JJ.Tyu^  *?  ^""^  ^^^  ^?^^^  ^^^'^^  ""'  Fahrenheit's  scale,  tends  to  become 
?<??  iru  •  .  ^^^  platinum,  and  may  thus  progressively  thicken  the  bottom  of  the 
still.  1  he  importance  of  preserving  this  vessel  entire,  and  of  economizing  the  fuel  re- 
quisite  to  heat  its  contents,  induces  the  refiner  to  detach  the  crust  of  gold  from  time  to 
time,  by  passing  over  the  bottom  of  the  still,  in  small  quantities,  a  dilute  nitro- 
muriatic  acid,  which  acts  readily  on  gold,  but  not  on  platinum.  But  as  this  operation 
IS  a  very  delicate  one,  it  must  be  conducted  with  great  circumspection.  The  danger  of 
such  adhering  deposi  es  is  much  increased  by  using  too  high  a  heat,  and  too  small  a 
body  of  acid,  relatively  to  the  metals  dissolved.  Hence  it  is  advantageous  to  employ 
alembics  of  large  size.  Should  any  lead  or  tin  get  into  the  platinum  still,  while  the  hot 
acid  IS  m  1  ,  the  precious  vessel  would  be  speedily  destroyed  ;  an  accident  which  has  not 
onfrequently  happened.    Each  operation  may  be  conveniently  finished  in  twelve  hours- 


REFINING  OF  GOLD  AND  SILVER. 


545 


BO  that  eat»n  alembic  may  refine  with  ease  160  marcs  daily.    Some  persons  work  more 
rapidly,  but  such  haste  is  hazardous. 

The  Parisian  refiners  restore  to  the  owners  the  whole  of  the  gold  and  silver  contained 
in  the  ingots,  reserving  to  themselves  the  copper  which  formed  the  alloy,  and  charging 
only  the  sum  of  5|  francs  per  kilogramme  (2-68  lbs.  troy)  for  the  expense  of  the  parting 
of  the  metals. 

If  they  are  employed  to  refine  an  ingot  of  silver  containing  less  than  one  tenth  of  gold, 
they  retain  for  themselves  a  two  thousandth  part  of  the  gold,  and  all  the  copper,  existing 
in  the  alloy ;  return  all  the  rest  of  the  gold,  with  the  whole  of  the  silver,  in  the  ingot; 
and  give,  besides,  to  the  owners  a  premium  or  bonus,  which  amounted  lately  to  |  of  a 
franc  on  the  kilogramme  of  metal.  Should  the  owner  desire  to  have  the  whole  of  the  gold 
and  silver  contained  in  his  ingot,  the  refiner  then  demands  from  him  2  francs  and  68  cen- 
times per  kilogramme,  retaining  the  copper  of  the  alloy.  As  to  silver  ingots  of  low 
standard,  the  perfection  of  the  refining  processes  is  such,  that  the  mere  copper  contained 
in  them  pays  all  the  costs ;  for  in  this  case,  the  refiner  restores  to  the  proprietor  of  the 
ingot  as  much  fine  silver  as  the  assay  indicated  to  exist  in  the  ingot,  contenting  himself 
with  the  copper  of  the  alloy.     See  in/r^. 

The  chemical  works  of  M .  Poizat,  called  affinage  (Pargenty  on  the  bank  of  the  cemai 
de  POurcq,  in  the  vicinity  of  Paris,  are  undoubtedly  the  most  spacious  and  best  arranged 
for  refining  the  precious  metals,  which  exist  in  the  world.  On  being  introduced  to  this 
gentleman,  by  my  friend  and  companion  M.  Clement-Desormes,  he  immediately  expressed 
his  readiness  to  conduct  me  through  his  fabrique,  politely  alluding  to  the  French 
translation  of  my  Dictionary  of  Chemistry,  which  lay  upon  the  desk  of  his  bureau. 
The  principal  room  is  240  feet  long,  40  feet  wide,  and  about  30  feet  high.  A  lofty 
chimney  rises  up  through  the  middle  of  the  apartment,  and  another  at  each  of  its  ends. 
The  one  space,  120  feet  long,  to  the  right  of  the  central  chimney,  is  allotted  to  the  pro- 
cesses of  dissolving  the  silver,  and  parting  the  gold;  the  other,  to  the  left,  to  the  eva- 
poration and  crystallization  of  the  sulphate  of  copper,  and  the  concentration  of  the  re- 
covered sulphuric  acid. 

M.  Poizat  melts  his  great  masses  of  silver  in  pots  made  of  malleable  iron,  capable  of 
holding  several  cwts.  each  ;  and  granulates  it  by  pouring  it  into  water  contained  in  large 
iron  pans.  The  granulated  silver  is  dried  with  heat,  and  carried  into  a  well  lighted  of- 
fice enclosed  by  glazed  casements,  to  be  weighed,  registered,  and  divided  into  determinate 
portions.  Each  of  these  is  put  into  a  cast-iron  pot,  of  a  flattened  hemispherical  shape, 
about  2  feet  in  diameter,  covered  with  an  iron  lid,  made  in  halves,  and  hinged  together 
in  the  middle  line.  From  the  lop  of  the  fixed  lid  a  bent  pipe  issues,  and  proceeds  down- 
wards into  an  oblong  leaden  chest  sunk  beneath  the  floor.  Four  of  the  above  cast-iron 
pots  stand  in  a  line  across  the  room,  divided  into  two  ranges,  with  an  intervening  space 
for  passing  between  them.  The  bottoms  of  the  pots  are  directly  heated  by  the  flame, 
one  fire  serving  for  two  pots.  Two  parts  of  concentrated  sulphuric  acid  by  weight  are 
poured  upon  ever?  part  of  granulated  silver,  and  kept  gently  boiling  till  the  whole  silv3r 
be  converted  into  a  pasty  sulphate. 

From  the  underground  leaden  chests,  a  leaden,  pipe  4  inches  in  diameter,  rises  verti- 
cally, and  enters  the  side  of  a  leaden  chamber,  which  is  supported  upon  strong  cross-beams 
or  rafters,  a  little  way  beneath  the  roof  of  the  apartment.  This  chamber,  which  is  30 
feet  long,  10  feet  wide,  and  6  feet  high,  is  intended  to  condense  the  sulphuric  acid  vapors, 
along  with  some  of  the  sulphurous  acid  ;  that  of  the  latter  being  promoted  by  the  admis- 
sion of  nitrous  gas  and  air,  which  convert  it  into  sulphuric  acid.  From  the  further  end 
of  this  chamber,  a  large  square  leaden  pipe  returns  with  a  slight  slope  towards  the  middle 
of  the  room,  and  terminates  at  the  right-hand  side  of  the  central  chimney,  in  a  small  leaden 
chest,  for  receiving  the  drops  of  acid  which  are  condensed  in  the  pipe.  From  that  chest 
a  pipe  issues,  to  discharge  into  the  high  central  chimney  the  incondensable  gases,  and 
also  to  maintain  a  constant  draught  through  the  whole  scries  of  leaden  chambers  back  to 
the  cast-iron  hemispherical  pots. 

Besideis  the  above  cast-iron  pots,  destined  to  dissolve  only  the  coarse  cupreous  silver, 
containing  a  few  grains  of  gold  per  pound,  there  are,  in  the  centre  of  the  apartment,  at 
the  right-hand  side  of  the  chimney,  6  alembics  of  platinum,  in  which  the  rich  aUoys  of 
gold  and  silver  are  treated  in  the  process  of  refining  gold*. 

The  pasty  sulphate  of  silver  obtained  in  the  iron  pots,  is  transferred  by  cast-iron  ladles 
with  long  handles  into  large  leaden  cisterns,  adjoining  the  pots,  and  there  diluted  with 
a  little  water  to  the  density  of  36°  Baume.  Into  this  liquor,  steam  is  admitted  through 
a  series  of  upright  leaden  pipes  arranged  along  the  side  of  the  cistern,  which  speedily 
causes  ebullition,  and  dilutes  the  solution  eventually  to  the  22d  degree  of  Baume.  In 
this  state,  the  liquid  supersulphate  is  run  oflT  by  leaden  syphons  into  large  oblong  leaden 
cisterns,  rounded  at  the  bottom  ;  and  is  there  exposed  to  the  action  of  ribands  of  copper, 
like  thin  wood  shavings.    The  metallic  silver  precipitates  in  a  pasty  form ;   and  the 


Ul 


mm 


546 


REFINING  OF  GOLD  AND  SILVER. 


I 


IN  ; 


ii  I  >i 


'   fi 


ji;  ■ 


fnpernaiant  sulphate  of  copper  is  then  run  off  into  a  cistern,  upon  a  somewhat  lower  ierel, 
where  it  is  left  to  settle  and  become  clear. 

The  precipitate  of  silver,  called  by  the  English,  water-silver,  and  by  the  French,  chaus 
i*argent,  is  drained,  then  strongly  squeezed  in  a  square  box  of  cast-iron,  by  the  action  ol 
a  hydraulic  press ;  in  which  60  pounds  of  silver  are  operated  upon  at  once. 

The  silver  lumps  are  dried,  melted  in  black  lead  crucibles,  in  a  furnace  built  near  the 
lilver  end  of  the  room,  where  the  superintendent  sits  in  his  bureaus,  closet  enclosed  by 
glazed  casements,  like  a  green-house.  The  whole  course  of  the  operations  is  so  planned, 
that  they  are  made  to  commence  near  the  centre  with  the  mixed  metals,  and  progressive- 
ly approach  towards  the  office  end  of  the  apartment  as  the  parting  processes  advance. 
Here  the  raw  material,  after  being  granulated  and  weighed,  was  given  out,  and  here  the 
pure  gold  and  silver  are  finally  eliminated  in  a  separate  state. 

In  the  other  half  of  the  hall,  the  solutions  of  sulphate  of  copper  are  evaporated 
in  large  shallow  leaden  pans,  placed  over  a  range  of  furnaces ;  from  which,  at  the  proper 
degree  of  concentration,  they  are  run  off  by  syphons  into  crystallizing  pans  of  the  same 
metal.  From  the  mother-waters,  duly  evaporated,  a  second  crop  of  crystals  is  obtained  j 
and  also  a  third,  the  last  being  anhydrous,  from  the  great  affinity  for  water  possessed  by 
the  strong  sulphuric  acid  with  which  they  are  now  surrounded.  The  acid  m  this  way 
parts  with  almost  the  whole  of  the  cupreous  oxyde,  and  is  then  transferred  into  a  large 
alembic  of  platinum  (value  1000/.),  to  be  rendered  fit,  by  re-conceniration,  for  acting  upon 
fresh  portions  of  granulated  silver.  The  capital  of  that  alembic  is  connected 
with  a  leaden  worm,  which  traverses  an  oblong  vessel,  through  which  a  stream  of  cola 

The  crystallized  sulphate  of  copper  fetched,  two  years  ago,  301.  a  ton.  It  is  almost  all 
soM  to  the  grocers  in  the  towns  of  the  agricultural  districts  of  France.  In  the  above  es- 
tablishment of  M.  Poizat,  silver  to  the  value  of  10,000/.  can  be  operated  upon  daily. 

There  is  a  steam  engine  of  6-horse  power  placed  in  a  small  glazed  chamber  at  one  side 
of  the  parting  hall,  which  serves  to  work  all  his  leaden  pumps  for  lifting  the  dilute  sul- 
phuric acid  and  acidulous  solutions  of  copper  into  their  appropriate  cisterns  of  concen- 
tration,  as  also  to  grind  his  old  crucibles,  and  drive  his  amalgamation  mill,  consisting  of 
a  pair  of  vertical  round-edged  wheels,  working  upon  one  shaft,  in  a  groove  formed  round 
a  central  hemisphere— of  cast-iron.  After  the  mercury  has  dissolved  out  of  the  ground 
crucibles  all  the  particles  of  silver  which  it  can  find,  the  residuary  earthy  matter  is  sold 
to  the  sweep-washers.  The  floor  of  the  hall  around  the  alembics,  pots,  and  cisterns,  is 
covered  with  an  iron  grating,  made  of  bars  having  one  of  their  angles  uppermost,  to  act 
as  scrapers  upon  the  shoes  of  the  operatives.  The  dust  collects  in  a  vacant  space  left 
beneath  the  gratin?,  whence  it  is  taken  to  the  amalgamation  mill.  The  processes  are 
so  well  arranged  and  conducted  by  M.  Poizat,  that  he  can  execute  as  much  business  m 
bis  establishment  with  10  workmen  as  is  elsewhere  done  with  from  40  to  50 ;  and  with 
less  than  3  grains  of  gold,  in  one  Paris  pound  or  7561  grains  of  silver,  he  can  defray  the 
whole  expenses  of  the  parting  or  refining. 

Since  26  parts  of  copper  afford  100  of  the  crystallized  sulphate,  the  tenth  of  coppei 
present  in  the  dollars,  and  most  foreign  coins,  will  yield  nearly  four  times  its  weight  of 
blue  vitriol;  a  subsidiary  product  of  considerable  value  to  the  refiner. 

The  works  of  M.  Poizat  are  so  judiciously  fitted  up  as  to  be  quite  salubrious,  and  have 
not  those  «« very  mischievous  effects  upon  the  trachea,"  which  Mr.  Matheson  slates  as 
being  common  in  his  refinery  works  in  the  Roya.  Mint.*  But,  in  fact,  as  refining  by 
sulphuric  acid  is  always  a  nuisance  to  a  neighborhood,  it  is  not  suffered  in  the  Monnaii 
Royale  of  Paris ;  but  is  best  and  most  economically  performed  by  private  enterprise  and 
fair  competition,  which  is  impossible  in  London,  on  account  of  the  anomalous  privilege, 
worth  at  least  2000/.  a  year,  possessed  by  Mr.  Malheson,  who  works  most  extensively 
for  private  profit  on  a  public  plant,  fitted  up  with  a  lofty  chimney,  platinum  vessels  to 
the  value  of  3000/.,  and  other  apparatus,  at  the  cost  of  the  government.  His  charge  to 
the  crown  for  refining  gold  per  lb.  troy,  is  6«.  Qd. ;  that  of  the  refiners  in  London,  who 
are  obliged,  for  fear  of  prosecution,  to  employ  the  more  expensive,  but  more  condensable, 
Bitric  acid,  is  only  4s.  That  of  the  Parisian  refiners  is  regulated  as  follows.  For  the 
dealers  in  the  precious  metals  :  — 

For  gold  bullion  containing  silver,  and  more  than  ^«-00_  of  gold,  6  fr.  12  c.  per  kilo- 

gramme,  =  2  fr.  29  c.  per  lb.  troy. 

For  silver  bullion,  containing  from  ^^1^  to  ^y>Oy  of  gold  (called  dares)^  3  fr.  27  c 

per  kilogramme,  =  1  fr.  22  c.  per  lb.  troy. 

For  the  Monnaie,  the  charges  are — 

For  gold  refined  by  sulphuric  acid,  when  alloyed  with  copper  only,  from  -f-^^  ^o  TT^JHTi 
C  fr.  per  kilogramme,  =  1  fr.  86  c.  per  lb.  troy. 

For  gold  alloyed  with  copper  and  silver,  whatever  be  the  quantity  of  silver,  5  fr.  75  c* 
per  kilogramme,  =  2  fr.  12  c.  per  lb.  troy. 

*  Report  of  Committee  of  House  of  Commona  on  the  Mint,  in  1837,  p.  91. 


REFRIGERATION  OF  WORTS.  547 

There  arc  ab»ut  ten  bullion  refiners  by  sulphuric  acid  in  the  environs  of  Paris;  two  of 
whom,M.  Poizat  St.  Andre,  and  M.  Chauviere,  are  by  far  the  most  considerable:  the 
former  working  about  300  kilogrammes  (  =  804  lbs.  troy)  daUy,and  the  latter  about  two 
Uiiras  01  that  quantity.  In  former  times,  when  competition  was  open  in  Ix>ndon,  Messrs. 
Browne  and  Bnnde  were  wont  to  treat  6  cwts.  of  sUver,  or  9  cwts.  of  gold  alloy,  daily, 
for  several  months  m  succession.  J»        J» 

The  result  of /rce/rarfe  in  refining  bullion  at  Paris  is,  that  the  silver  bars  imported 
into  London  from  South  America,  &c.,  are  mostly  sent  off  to  Paris  to  be  stripped  of  the 
few  grams  of  gold  which  they  may  contain,  and  are  then  brought  back  to  be  sold  here. 

*  «?I!**"^  *^.  ^""^^  *"  """^  ^*"®  ^^'  ""^  s^*^^'*»  P«^y  ^^^  "^finers  there  for  taking  them 
out.  What  a  disgrace  is  thus  brought  upon  our  manufacturing  industry  and  skill,  by 
the  monopoly  charges  m  refining  and  assaying  granted  to  two  individuals  in  our  Roval 
Mint. 

Mr.  Bingley's  charges  for  assaying  at  the  Royal  Mint  in  London,  are— 

For  an  assay  of  gold,  4s. ;  for  a  parting  assay  of  gold  and  silver,  6*. ;  for  a  sUver  assay 

2».  brf.— charges  which  absorb  the  profits  of  many  a  transaction. 

The  charges  at  the  Royal  Mint  of  Paris,  for  assays  made  under  the  following  distin- 

|aished  chemical  savants— D&rcct,  Directeur  i  Breant,  VerijicateHT:  Chevillot  and  Pelouze. 

iLssayturs;  are —  y^^y^^ 

For  an  assay  of  gold,  or  dorc  (a  parting  assay),  3  francs. 

Ttr  n      r"        ^"T  "~,  —         0-  80  c.  =  8(i.  English. 

M,  Cxay  Lussac  is  the  assayer  01  the  Bureau  de  Garantie  at  the  Monnaie  RoLole,  an 
office  which  corresponds  10  the  Goldsmiths'  Hall  at  London.  The  silver  assays  in  all 
the  official  establishments  of  Europe,  except  the  two  in  London,  are  made  by  the  humid 
method,  and  are  free  from  those  errors  and  blunders  which  daily  annoy  and  despoil  the 
British  bullion  merchant,  who  is  compelled  by  the  Mint  and  Bank  of  England  to  buy  and 
sellby  the  c«/)c//a/i(wi  assay  of  Mr.  Bindley.    See  Assay  and  Silver. 

REFRIGERATION  OF  WORTS,  &c.  In  August,  1826,  Mr.  Yandall  obtained 
a  patent  <or  an  apparatus  designed  for  cooling  worts  and  other  hot  fluids,  without 
exposing  them  to  evaporation.  Utensils  employed  for  this  purpose,  are  generally  caUed 
refrigerators^  and  are  so  constructed,  that  a  quantity  of  cold  water  shall  be  brought  in 
contact  with  the  vessel  which  contains  the  heated  fluid.  But  in  every  construction  of 
refrigerator  heretofore  used,  the  quantity  of  cold  water  necessarily  employed  in  the 
operation  greatly  exceeded  the  quantity  of  the  fluid  cooled,  which,  in  some  situations, 
where  water  cannot  be  readily  obtained,  was  a  serious  impediment  and  objection  to  the 
use  of  such  apparatus. 

The  inventor  has  contrived  a  mode  of  constructing  a  refrigerator,  so  that  any  quantity 
of  wort  or  other  hot  fluid  may  be  cooled  by  an  equal  quantity  of  cool  water:  the  process 
being  performed  with  great  expedition,  simply  by  passing  the  two  fluids  throigh  very  nar- 
row  passages,  m  opposite  directions,  the  result  of  which  is,  that  the  cold  liquor  imbibes 
the  heat  from  the  wort,  or  other  fluid,  and  the  temperature  of  the  hot  fluid  is  reduced  in 
the  same  ratio.  ^         *->*«v^*i  ua 

hP  mft  ^^%  ^?^'  ^201  represent  different  forms  in  which  the  apparatus  is  proposed  to 
^rvi  T?  T  ^'?  ^''''^  ^'^^  V^^^^K^s ;  the  third,  channels  running  in  convolute 
J.nJfh   J^T       r*^5  f  ^''*^^'  *''^  ^^*^^  ^°^*"  ^'^P^^^ity  in  thickness,  but  of  great 

Jftg.  1202  is  the  section  of  a  portion  of  the  apparatus  shown  at  figs,  1199  &  1200  upon 
Sue  nSt  r?J'rl.  ''  ?  "'^^^  ^y  connecting  three  sheets  of  copper  or  any  othe  thhi  S2 
tollic  plates  together,  leavi  \g  parallel  spaces  between  each  plate  for  the  passage  of  ^e 
fluids,  represented  by  the  biack  lines.  passage  oi  me 

ribI\TnoTt?on.' oVmirjrf  b^  occasionally  introducing  between  the  plates  thin  straps, 

S^P  rhrnnTthf?  •?  '    ^  "^^'^^  ?^*"'  ^^"^^  thin  channels  are  produced,  and  throuS 

!.!^^  and  Zl.  •  K^'  ""'^  *"^^"^^  ^°  ^^  P^s^^d'  ^^^  cold  Uquor  running  in  one  dirls- 
Uon,  and  the  hot  m  the  reverse  direction.  ""cv- 

Supposing  that  the  passages  for  the  fluids  are  each  one  eighth  of  an  inch  thick  then 
the  entire  ength  for  the  run  of  the  fluid  should  be  about  80  feet,  the  breadth  of  the  ai^ 
^Tn  ?r/  "y;?^,'^<^c«"*i"^to  the  quantity  of  fluid  intenTeitoVe  pas^J^^roug^^^^^^ 

shouirbe  exienied  to  I'^Xt  """h  '""^^  I  ^"^^^  «^  ^"^  ^"^^  thicCthen  theirWglh 
Should  be  extended  to  160  feet;  and  any  other  dimensions  in  similar  proportions :  but  a 

Hrhntrpr  nl"  T  ^"!?''5*!  ^"^^'^^«  Patentee considei^  wouldTob  ectiin^^^^^^^ 
t  on^  thanrp  inid/«L^'r^^  't'  ^'  ^^'^'^  ^''^  recommended,  is  under  thi  considera- 
i^'fmm  a  hildtnT  /^r^""  ^«>"?\the  apparatus  by  some  degree  of  hydrostatic  pres- 
tTli^Th.  nf  ivi  n  ^^^^^fU-^^t^above ;  but  if  the  fluids  flow  without  pressure,  then 
me  lengths  of  the  passages  need  not  be  quite  so  great 

In   the  apparatus  constructed  as  shown  in  perspective  at  fig,  1199,  and  further 


.1   : 


If      ; 


■T- 

i 


;  I 


348 


REFRIGERATION  OF  WORTS. 


REFRIGERATION  OF  WORITS. 


549 


seveloped  by  the  section,  Jig»  1202,  cold  water  is  to  be  introduced  at  the  funnel  », 

whence  it  passes  down  the  pipe  b,  and 
through  a  long  slit  or  opening  in  the  side 
of  the  pipe,  into  the  passage  c,  c  (see  fig, 
1202),  between  the  plates,  where  it  flows 
in  a  horizontal  direction  through  the 
channel  towards  the  discharge-pipe  d. 
When  such  a  quantity  of  cold  water  has 
passed  through  the  funnel  a,  as  shall  have 
filled  the  channel  c,  c,  up  to  the  level  of 
the  top  of  the  apparatus,  the  cock  e  being 
shut,  L'len  the  hot  wort  or  liquor  intended 
to  be  cooled,  may  be  introduced  at  the 
funnel  /,  and  which,  descending  in  the 
pipe  gj  passes  in  a  similar  manner  to  the 
former,  through  a  long  slit  or  opening  in 
the  side  of  the  pipe  g,  into  the  extended 
passage  r.,^  (see^g.  1202), and  from  thence 
proceeds  horizontally  into  the  discharge- 
pipe  i. 
_  The  two  cocks  c  and  k,  being  now 

opened,  the  wort  or  other  liquor  is  drawn  off,  or  otherwise  conducted  away  through  the 
cock  fc,  and  the  water  through  e.  If  the  apertures  of  the  two  cocks  e  and  k  are  equal, 
and  the  channels  equal  also,  it  follows  that  the  same  quantity  of  wort,  &c.,  will  flow 
through  the  channel  A,  h,  A,  in  a  given  time,  as  of  water  through  the  channel  c,  c;  and  by 
the  hot  fluid  passing  through  the  apertures  in  contact  with  the  side  of  the  channel  which 
contains  the  cold  fluid,  the  heat  becomes  abstracted  from  the  former,  and  communicated  to 
the  latter  ;  and  as  the  hot  fluid  enters  the  apparatus  at  that  part  which  is  in  immediate 
contact  with  the  part  where  the  cooling  fluid  is  discharged,  and  the  cold  fluid  enters  the 
apparatus  at  that  part  where  the  wort  is  discharged,  the  consequence  is,  that  the  wort  or 
other  hot  liquor  becomes  cooled  down  towards  its  exit-pipe  nearly  to  the  temperature  of 
cold  water ;  and  the  temperature  of  the  water,  at  the  reverse  end  of  the  apparatus,  be- 
comes raised  nearly  to  that  of  the  boiling  wort. 

It  only  remains  to  observe,  that  by  partially  closing  either  of  the  exit-cocks,  the  quan- 
tity of  heat  abstracted  from  one  fluid,  and  communicated  to  the  other,  may  be  regulated ; 
for  instance,  if  the  cock  e  of  the  water-passage  be  partially  closed,  so  as  to  diminish  the 
quantity  of  cold  water  passed  through  the  apparatus,  the  wort  or  other  hot  fluid  conducted 
through  the  other  passages  will  be  discharged  at  a  higher  temperature,  which  in  some 
cases  will  be  desirable,  when  the  refrigerated  liquor  is  to  be  fermented. 

J'tg.  1200  exhibits  an  apparatus  precisely  similar  to  the  foregoing,  but  diflferent  in  its 
position ;  for  instance,  the  zigzag  channels  are  made  in  obliquely  descending  planes. 

a  is  the  funnel  for  the  hot  liquor,  whence  it 
descends  through  the  pipe  d  into  the  channel 
c,  c  (see  yig.  1202),  and  ultimately  is  discharged 
through  the  pipe  b,  at  the  cock  e.  The  cold 
water  being  introduced  into  the  funnel  /,  and 
passing  down  the  pipe  t,  enters  the  zigzag 
channel  h,  h,  and,  rising  throi^h  the  apparatus, 
runs  ofl*  by  the  pipe  g,  and  is  discharged  at  the 
cock  below. 

The  passages  of  this  apparatus  for  heating 
and  cooling  fluids,  may  be  bent  into  various 
contorted  figures ;  one  form  found  particularly 
convenient  under  some  applications,  is  that 
represented  at  fig.  1201,  which  is  contained 
in  a  cylindrical  case.  The  passages  here  run 
in  convolute  curves,  the  one  winding  in  a 
spiral  to  the  centre,  the  other  receding  from  the 
centre. 

The  wort  or  other  hot  liquor  intended  to 
be  cooled,  is  to  be  introduced  at  the  funnel  a, 
and  passing  down  the  pipe  b,  is  delivered  into 
the  open  passage  c,  which  winds  round  to  the 
central  chamber  d,  and  is  thence  discharged 
through  the  pipe  e,  at  the  cock  /.  The  cold 
water  enters  the  apparatus  at  the  funnel  f, 
and  proceeding  down  the  pipe  h,  enters  the 


1200 


closed  channel  t,  and  after  traversing  round  through  the  apparatus,  is  in  like  manner 
discharged  through  the  pipe  fe,  at  the  cock  I.    Or  the  hot  liquor  may  be  passed  through 

the  closed  channel,  and  the  cold  through 
the  open  one ;  or  these  chambers  may  be 
both  of  them  open  at  top,  and  ihe  ap- 
paratus covered  by  a  lid  when  at  work, 
the  principal  design  of  which  is  to  aflford 


the  convenience  of  cleaning  them  more 
readily  than  could  be  done  if  they  were 
closed  ;  or  they  may  be  both  closed. 

A  similar  ingenious  apparatus  for  cool- 
ing brewer's  worts,  or  wash  for  distillers, 
and  also  for  condensing  spirits,  in  place 
of  the  ordinary  worm  tub,  is  called  by 
the  inventor,  Mr.  Wheeler,  an  Archi- 
medes condenser,  or  refrigerator,  the  pe- 
culiar novelty  of  which  consists  in  form- 
ing the  chambers  for  the  passage  of  the 
fluids  in  spiral  channels,  winding  round 
a  central  tube,  through  which  spiral 
channels  the  hot  and  cold  fluids  are  to  be 

passed  in  opposite  directions. 

Fig,  1203  represents  the  external  appearance  of  the  refrigerator,  enclosed  in  a  cylin- 
drical case ;  fig,  1204,  the  same,  one  half  of  the  case  being  removed  to  show  the  form 


1202 


of  the  apparatus  within  ;  and  fig.  1205,  a 
section  cut  through  the  middle  of  the  appa- 
ratus perpendicularly,  for  the  purpose  of 
displaying  the  internal  figure  of  the  spiral 
channels. 

The  apparatus  is  proposed  to  be  made  of 
sheet  copper,  tinned  on  its   surface,  and   is 
formed  by  cutting  circular  pieces  of  thin  cop- 
„  per,  or  segments  of  circles,  and  connecting 

ihem  together  by  rivets,  solder,  or  by  any  other  convenient  means,  as  coppersmiths  usu- 
ally do ;  these  circular  pieces  of  copper  being  united  to  one  another,  in  the  way  of  a  spiral 
or  screw,  form  the  chambers  through  which  the  fluids  are  to  pass  within,  in  an  ascending 
or  descending  inclined  plane. 


1203 


1204 


Inyig*.  1204  <k  1205,  a,  a,  is  the  central  tube  or  standard  (of  any  diameter  that  may 
be  found  convenient),  round  which  the  spiral  chambers  are  to  be  formed :  6,  b,  are  the 
sides  of  the  outer  case,  to  which  the  edges  of  the  spiral  fit  closely,  but  need  not  be 
attached ;  c,  c,  are  two  of  the  circular  plates  of  copper,  connected  together  by  rivets  at 
the  edges,  in  the  manner  shown,  or  by  any  other  suitable  means;  J,  is  the  chamber, 
formed  by  the  two  sheets  of  copper,  and  which  is  carried  round  from  top  to  bottom  in  a 
»piral  or  circulai  'uclmed  plane,  by  a  succession  of  circular  plates  connected  to  each 
other. 


550 


RENNET. 


RESINS. 


651 


yi 


'  I 


t  \ 


The  hot  fluid  is  admitted  into  the  spiral  chamber  d,  through  a  trumpet  or  wide- 

I  I ]  I        mouthed  lube  e,  at  top,  and  it 

I  t|       r-jTi^  '^1  i        discharged     at     bottom     by    aa 

aperture  and  cock  /.  The  cold 
water  which  is  to  be  employed 
as  the  cooling  material,  is  to  be 
introduced  through  the  pipe  g, 
in  the  centre,  from  whence  dis- 
charging itself  by  a  hole  at  bot- 
tom, the  cold  water  occupies 
the  interior  of  the  cylindrical 
case  b,  and  rises  in  the  spiral 
passage  A,  between  the  coils  of 
the  chamber,  until  it  ascends  to 
the  top  of  the  vessel,  and  then  it 
flows  away  by  a  spout  t,  seen  in 
Jig-  1203. 

It  will  be  perceived  that  the 
hot  fluid  enters  the  apparatus 
at  top,  and  the  cold  fluid  at 
bottom,  passing  each  other,  by 
means  of  which  an  interchange 
of  temperatures  takes  place 
through  the  plates  of  copper, 
the  cooling  fluid  passing  ofl"  at 
top  in  a  heated  state,  by  means 
of  the  caloric  which  it  has  ab- 
stracted from  the  hot  fluid;  and 
the  hot  fluid  passing  oflf  through 
the  pipe  and  cock  at  bottom,  in 
a  very  reduced  state  of  tempera- 
ture, by  reason  of  the  calorie 
which  it  held  having  been  given 
out  to  the  cooling  fluid. 

Fig.  1206  is  a  side  view  and 
■ectioR  of  Wagenmann's  apparatus  for  cooling  worts ;  Jig.  1207,  a  view  from  above.  The 
preceding  contrivances  seem  to  be  far  preferable. 

a,  a,  is  the  tub  for  receiving  the  apparatus,  whose  central  upright  shaft  6,  rests  upon  n 
step  c,  in  the  bottom,  and  revolves  at  top  in  a  bu«h  at  d,  made  fast  to  a  bar  e,  fixed  flat 
across  the  mouth  of  the  tub.  The  shaft  may  be  driven  by  the  two  bevel  wheels  /,/,  at 
right  angles  to  each  other,  and  the  horizontal  rod  turned  by  hand  ;  or  the  whole  may  be 
impelled  by  any  power,  g,  is  an  iron  basin  for  receiving  the  cold  water  from  the  spout 
kf  supplied  by  a  well;  it  flows  out  of  the  basin  through  two  tubes  it,  down  into  the  lower 
part  of  the  cooler  fe  k.  The  cooler  consists  of  two  flat  vessels,  both  of  which  are  formed 
of  a  flat  interior  plate,  and  an  arched  exterior  one,  so  that  their  transverse  section  is  plano- 
ronvex.  The  water  which  flows  along  the  tubes  i  i,  spreads  itself  upon  the  bottom  of  the 
cooler,  and  then  rises  through  the  scabbard-shaped  tubes  /  /,  ice,  into  the  upper  annular 
Tcssel  mm;  whence  it  is  urged  by  hydrostatic  pressure,  in  a  now  heated  state,  through 
the  slanting  tubes  n  n,  which  terminate  in  the  common  pipe  o,  of  the  annular  basin  p  p, 
and  is  thence  discharged  by  the  pipe  q.  The  basin  p  />,  is  supported  by  the  two  bearers 
r,  made  fast  to  the  cross-beam  e.  There  is  in  the  lowest  part  of  the  hollow  ring  at  bot- 
tom, a  screw  plug,  which  may  be  opened  when  it  is  desired  to  discharge  the  whole  con- 
tents, and  to  wash  it  with  a  stream  of  water. 

REGULUS  is  a  term  introduced  by  the  alchemists,  now  nearly  obsolete.  It  means 
literally  a  little  king,  and  refers  to  the  metallic  slate  as  one  of  royalty,  compared  with 
the  native  earthy  condition.  Antimony  is  the  only  metal  now  known  by  the  name  of 
r^ulus. 

RENNET.  The  gastric  juice  of  the  stomach  of  the  sucking  calf,  which,  being 
extracted  by  infusion  immediately  after  the  death  of  the  animal,  serves  to  curdle  milk. 
As  the  juice  passes  rapidly  into  putrefaction,  the  stomach  must  be  salteil  after  the  outer 
skin  has  been  scraped  off,  and  all  the  fat  and  useless  membranes  carefully  removed.  It 
is  only  the  inner  coat  which  is  to  be  preserved  after  it  is  freed  from  any  curd  or  other 
extraneous  matter  in  the  stomach.  The  serum  left  in  it  should  be  pressed  out  with  a 
cloth,  and  is  then  to  be  replaced  in  the  stomach  with  a  large  quantity  of  the  best  salt. 
The  skins,  or  veils  as  they  are  called,  are  next  put  into  a  pan  and  covered  with  a  saturated 
solution  of  salt  and  soaked  for  some  hours ;  but  there  should  be  no  more  brine  than  covers 
the  veils.    They  are  afterwards  hung  up  to  dry,  a  piece  of  wood  being  put  crosswise  into 


each  to  stretch  them  out  They  should  be  perfectlv  iSried  and  look  like  parchment.  In 
this  state  they  may  be  kept  in  a  dry  place  for  any  length  of  time,  and  are  always  ready 
for  use. 

Pieces  of  veil  are  cut  off  and  soaked  for  some  hours  in  wey  or  water,  and  the  whole  is 
added  to  the  warm  milk  for  curdling  it,  its  strength  having  been  first  tested  on  a  small 
c[uantity.  By  the  rapidity  with  which  it  curdles  and  the  form  of  the  flakes,  a  judgment 
is  formed  of  its  strength  and  the  quantity  required  for  the  whole  milk. 

RESINS,  (^e«ine«,  Fr. ;  JIarze,  Germ.) ;  are  proximate  principles  found  in  most  vege- 
tables, and  in  almost  every  part  of  them ;  but  the  c«ily  resins  w^hich  merit  a  particular 
description,  are  those  which  occur  naturally  in  such  (quantities  as  to  be  easily  collected  or 
extracted.  They  are  obtained  chiefly  in  two  ways,  either  by  spontaneous  exudation  from 
the  plants,  or  by  extraction  by  heat  and  alcohol.  In  the  first  case,  the  discharge  of  resin 
in  the  liquid  state  is  sometimes  promoted  by  artificial  incisions  made  in  summer  through 
the  bark  into  the  wood  of  the  tree. 

Resins  possess  the  following  general  properties: — They  are  soluble  in  alcohol,  insoluble 
in  water,  and  melt  by  the  application  of  heat,  but  do  not  volatilize  without  partial  decom- 
position. They  have  rarely  a  crystalline  structure,  but,  like  gums,  they  seldom  affect  anv 
peculiar  form.  They  are  almost  all  translucid,  not  often  colourless,  but  generally  brown, 
occasionally  red  or  green.  Any  remarkable  taste  or  smell,  which  they  sometimes  possess, 
may  be  ascribed  to  some  foreign  matter,  commonly  an  essential  oil  Their  specific 
gravity  varies  from  092  to  1-2.  Their  consistence  is  also  very  variable.  The  greater 
part  are  hard,  with  a  vitreous  fracture,  and  so  brittle  as  to  be  readily  pulverized  in  the 
cold-  Some  of  them  are  soft,  a  circumstance  probably  dependent  upon  the  presence  of  a 
heterogeneous  substance.  The  hard  resins  do  not  conduct  electricity,  and  they  become 
negatively  electrical  by  friction.  When  heated  they  melt  more  or  less  easily  into  a 
thick  viscid  liquid,  and  concrete,  on  cooling,  into  a  smooth  shining  mass,  of  a  vitreous 
fracture,  which  occasionally  flies  off  into  pieces,  like  Prince  Rupert's  drops ;  especially, 
after  being  quickly  cooled,  and  scratched  with  a  sharp  point.  They  take  fire  by  contact 
of  an  ignited  body,  and  bum  with  a  bright  flame,  and  the  diffusion  of  much  sooty 
smoke.  When  distilled  by  themselves  in  close  vessels,  they  afford  carbonic  acid  and 
carburetted  gases,  erapyreumatic  oil  of  a  less  disagreeable  smell  than  that  emitted 
by  other  such  oils,  a  little  acidulous  water,  and  a  very  little  shining  charcoal  See 
Rosin  Gas. 

Resins  are  insoluble  in  water,  but  dissolve  in  considerable  quantities  in  alcoliol,  both 
hot  and  cold.  This  solution  reddens  tincture  of  litmus,  but  not  syrup  of  violets ;  it  is 
decomposed  by  water,  and  a  milkiness  ensues,  out  of  which  the  particles  of  the  resin 
gradually  agglomerate.  In  this  state  it  contains  water,  so  as  to  be  soft,  and  easily 
kneaded  between  the  fingers;  but  it  becomes  hard  and  brittle  again  when  freed  by 
fusion  from  the  water.  The  resins  dissolve  in  ether  and  the  volatile  oils,  and,  with  tlie 
aid  of  heat,  combine  with  the  unctuous  oils.  They  may  be  combined  bv  fusion  with 
eulphur,  and  with  a  little  phosphorus.  Chlorine  water  bleaches  several  coloured  resins, 
if  they  be  diffused  in  a  milky  state  through  water.  The  carburet  of  sulphur  dissolves 
them. 

Resins  are  little  acted  upon  by  acids,  except  by  the  nitric,  which  converts  them 
into  artificial  tan.  They  combine  readily  with  the  alkalis  and  alkaline  earths,  and 
form  what  were  formerly  reckoned  soaps;  but  the  resins  are  not  truly  saponified; 
they  rather  represent  the  acid  constitution  themselves,  and,  as  such,  saturate  the  salifi- 
able bases. 

Every  resin  is  a  natural  mixture  of  several  other  resins,  as  is  the  case  also  with  oils; 
one  prmciple  being  soluble  in  cold  alcohol,  another  in  hot,  a  third  in  ether,  a  fourth  in  oil 
of  turpentine,  a  fifth  in  naphtha,  Ac.  Tlie  soft  resins,  which  retain  a  certain  portion 
of  volatile  oil,  constitute  what  are  called  balsams.  Certain  other  balsams  contain  bensoic 
acid.  The  solid  resins  are,  amber,  anime,  benzoin,  colophony  (common  rosin),  copal, 
dammar  a,  dragon's  blood,  elemi,  guaia/:,  lac,  resin  oi  jalap,  ladanum,  tnastic,  tandarack, 
ftorax,  takamahae. 

An  ingenious  memoir  upon  the  resins  of  dammar,  copal,  and  anime,  has  lately  been 
published  by  M.  Guibourt,  aa  eminent  French  pharmacien,  from  which  the  following 
extracts  may  be  found  interesting. 

The  hard  copal  of  India  and  Africa,  especially  Madagascar,  is  the  product  of  the 
Hymenaa  verrucosa  ;  it  is  transparent  and  vitreous  within,  whatever  may  be  its  appear- 
ance outside;  nearly  colourless,  or  of  a  tawny  yellow;  without  taste  or  smell  in  the 
cold,  and  almost  as  liard  as  amber,  which  it  much  resembles,  but  from  which  it  may  be 
distinguished,  1st,  by  its  melting  and  kindling  at  a  candle-flame,  and  running  down  in 
drops,  while  amber  burns  and  swells  up  without  flowing;  2dly,  this  hard  copal  or 
anim6  when  blown  out  and  still  hot,  exhales  a  smell  like  balsam  copaiva  or  capivi ;  while 
amber  exhales  an  unpleasant  bituminous  odour;  3dly,  when  moistened  bv  alcohol  of 
85  per  cent.,  copal  becomes  sticky,  and  shows  after  drying  a  gkzed  opaque  surfkcei, 


662 


RESINS. 


^ii 


ii 


'If 


while  amber  is  not  affected  by  alcohol ;  4thly,  the  copal  affords  no  succinic  add,  as  amber 
does,  on  distillation. 

When  the  pulverised  copal  is  digested  in  cold  alcohol  of  0-830,  it  leaves  a  considerable 
residuum,  at  first  pulverulent,  but  which  swells  afterwards,  and  forms  a  slightly  coherent 
mass.  When  this  powder  is  treated  with  boiling  alcohol  it  assumes  the  consistence  of  a 
thick  gluten,  like  crumbs  of  bread,  but  which  does  not  stick  to  the  fingers  Thus  treated, 
it  affords,  ^     '  ^ 


RHODIUM. 


553 


Resin  soluble  in  cold  alcohol 
Resin  dissolved  in  boiling  alcohol    - 
Resin  insoluble  in  both 


81-42 

4-00 

65-71 

100-83 


The  small  excess  is  due  to  the  adhesion  of  some  of  the  menstruum  to  the  resins. 

Ether,  boiling  hot,  dissolves  39-17  per  cent,  of  copal. 

Essence  (spirits)  of  turpentine  does  not  dissolve  any  of  the  copal,  but  it  penetrates  and 
combines  with  it  at  a  heat  of  212°  Fahr. 

The  property  of  swelling,  becoming  viscid  and  elastic,  which  Berzelius  assigns  to  copal 
belongs  not  to  it,  but  to  the  American  resin  of  courbaril,  or  the  occidental  anime  -  and  the 
prooerty  of  dissolving  entirely  in  ether  belongs  to  the  aromatic  dammar,  a  friable  and 
tender  resin. 

2.  Resin  of  courbaril  of  Rio  Janeiro,  the  English  gum-anira6,  and  the  semi-hard 
copal  of  the  French.  It  is  characterised  by  forming,  in  alcohol,  a  bulky,  tenacious 
elastic  mass.  It  occurs  m  rounded  tears,  has  a  very  pale  glassy  aspect,  transparent 
within,  covered  with  a  thin  white  powder,  which  becomes  glutinous  with  alcohol 
Another  variety  is  soft,  and  dissolves,  for  the  most  part,  in  alcolK>l  •  and  a  third* 
resembles  the  oriental  copal  so  much  as  to  indicate  that  they  may  both  be  produced 
from  the  same  tree.  100  parts  of  the  oriental  and  the  occidental  anime  yield  respec- 
tively the  following  residua : —  J  f 


Oriental 
Occidental 


"With  alcohol. 
65-71 
43-53 


With  ether. 
60-83 
27-50 


With  essence. 
Ill 
75-76 


The  hard  and  soft  copals  possess  the  remarkable  property  in  common  of  becoming 
soluble  in  alcohol,  after  being  oxygenated  in  the  air. 

8.  Dammar  puti,  or  dammar  batu.— This  resin,  soft  at  first,  becomes  eventually  like 
amber,  and  as  hard.  It  is  little  soluble  in  alcohol  and  ether,  but  more  so  ia  essence 
ef  turpentine. 

4.  Aromatic  dammar. — This  resin  occurs  in  large  orbicular  masses.  It  is  pretty  soluble 
in  alcohol  Only  small  samples  have  hitherto  been  obtained.  Of  100  parts,  3  are  inso- 
luble in  alcohol,  none  in  ether,  and  93  in  essence  of  turpentine.  M.  Guibourt' thinks  that 
this  resin  comes  from  the  Molucca  isles.  Its  ready  solubility  in  alcohol,  and  great  hard- 
ness, render  it  valuable  for  varnish-making. 

6.  Slightly  aromatic  dammar  leaves,  after  alcohol,  37  per  cent. ;  and  after  ether  17  per 
cent. ;  and  after  essence  87  per  cent.  ' 

6.  Tender  and  friable  dammar  selan. — Tliis  resin  occurs  in  considerable  quantity  in 
commerce  (at  Paris).  It  is  in  round  or  oblong  tears,  vitreous,  nearly  colourless  and  trans- 
parent within,  dull  whitish  on  the  surfaces.  It  exhales  an  agreeable  odour  of  olibanuin 
or  mastic,  when  it  is  heated.  It  crackles  with  the  heat  of  the  hand,  like  roll-sulphur.  It 
becomes  fluid  in  boiling  water,  but  brittle  when  cooled  again.  It  sparkles  and  burns  at 
the  flame  of  a  candle ;  but  this  being  the  effect  of  a  volatile  oil  the  combustion  soon 
ceases. 


Resin  soluble  in  cold   alcohol 
Resin  insoluble  in  boiling  alcohol 


75-28 
20-86 


It  dissolves  readily  and  completely  in  cold  essence  of  turpentine,  and  forms  a  good 
varmsh.  M.  Guibourt  refers  the  origin  of  this  resin  to  the  Dammara  selanica  of 
Rumphius.    Of  the  preceding  resins,  100  parts  have  left  respectively 


Hard  copal,  or  anime 
Tender  copal 
Dammar  puti 
Dammar  aromatic 
Dammar  austral 
Dammar  slightly  aromatic 
Dammar  friable 


Alcohol  of  0-830. 

-  65-71 

-  43-53 

3-0 

-  43-33 

-  37-00 

-  20-86 


Insoluble  In 
Ether. 

60-83 
27-50 


36-66 

17-00 

2-00 


Essence. 
Ill 
76-76 

93 
80 
87 


RESIN,  KAURI  or  COWDEE,  is  a  new  and  very  peculiar  substance,  recently  im- 
ported in  considerable  quantities  from  New  Zealand,  which  promises  to  be  useful  in  the 
arts.    It  oozes  from  the  trunk  of  a  noble  tree  called  Dammara  australis,  or  Pinus  kauri, 
which  rises  sometimes  to  the  height  of  90  feet  without  a  branch,  with  a  diameter  of  12  feet, 
and  furnishes  a  log  of  heart  timber  of  11  feet.     The  resin,  which  is  called  Cowdee  gum 
by  the  importers,  is  brought  to  us  in  pieces  varying  in  size  from  that  of  a  nutmeg  to  a 
block  of  2  or  3  cwts.    The  color  varies  from  milk-white  to  amber,  or  even  deep  brown  ; 
some  pieces  are  transparent  and  colorless.     In  hardness  it  is  intermediate  between  copal 
and  resin.     The  white  milky  pieces  are  somewhat  fragrant,  like  elemi.     Specific  gravity, 
1*04  to  1*06.    It  is  very  inflammable,  burns  all  away  with  a  clear  bright  flame,  but  does 
not  drop.    When  cautiously  fused,  it  concretes  into  a  transparent  hard  tough  mass,  like 
shellac.     It  affords  a  fine  varnish  with  alcohol,  being  harder  and  less  colored  than  mastic, 
while  it  is  as  soluble,  and  may  be  had  probably  at  one  tenth  of  the  price.     A  solution  in 
alcohol,  mixed  with  one  fourth  of  its  bulk  of  a  solution  in  oil  of  turpentine,  forms  an 
excellent  varnish,  which  dries  quickly,  is  quite  colorless,  clear  and  hard.     It  is  insoluble 
kn  pyro-acetic  (pyroxilic  ?)  spirit.     Combined  with  shellac  and  turpentine,  it  forms  a  good 
sealine-wax. 
REVERBERATORY  FURNACE  ;  see  Copper,  Iron,  and  Soda. 
RETORT.    For  producing  coal  gas,  there  are  many  modifications,  varying  in  dimension 
and  shape  with  the  caprice  of  the  constructor,  and  in  many  cases  without  any  definite  idea 
of  the  principle  to  be  aimed  at. 
They  may  be  divided  into  three  general  classes  : 

1st.  The  circular  retort,  from  twelve  to  twenty  inches  in  diameter,  and  from  six  to 
nine  feet  in  length.  This  retort  is  used  in  Manchester  and  some  other  places,  in  gene- 
ral for  the  distillation  of  cannel,  or  Scotch  parrot  coal.  It  answers  for  the  distillation 
of  a  coal  which  retains  its  form  in  lumps,  and  is  advantageous  only  from  the  facility 
with  which  its  position  is  changed,  when  partially  destroyed  by  the  action  of  fire  on  the 
under  side. 

2d.  The  small  or  London  d  retort,  so  called  in  consequence  of  its  having  first  been 
nsed  by  the  chartered  tnmpany  in  London,  being  still  in  use  at  their  works,  and  re- 
commended by  their  engineer.  This  retort  is  12  inches  broad  on  the  base,  11  inches  high, 
and  7  feet  long,  carbonizing  one  and  a  half  to  two  bushels  at  a  charge. 

3rd.  The  York  D  retort,  (so  called  in  consequence  of  its  having  been  introduced 
by  Mr.  Outhit,  of  York,)  and  the  modifications  of  it,  among  which  I  should  include  the 
elliptic  retort,  as  having  the  same  general  purpose  in  view.  The  difference  between  the 
London  and  York  D  retorts,  consists  only  in  an  extension  of  surface  upon  which  the  coal 
i8  spread.     See  Gas-light. 

Clay  retorts  for  gas  works.  Mr.  Joseph  Cowan,  of  Newcastle,  has  much  improved 
the  quality  of  clay  retorts,  by  mixing  in  their  composition  with  Newcastle  fire  clay, 
or  any  other  good  fire  clay  of  the  coal  measures,  sawdust,  pulverised  coke,  or  carbon 
obtained  from  the  inside  of  gas  iron  retorts,  <fec.,  in  such  proportion  as  the  nature 
of  the  clay  may  require.  The  more  aluminous  the  clay,  the  more  carbonaceous  mat- 
ters is  needed,  to  take  away  their  tendency  to  crack  by  great  or  unequal  shrinkage. 
He  uses  a  wooden  cylindrical  box  or  chamber  as  a  mould,  into  which  the  plastic  clay 
mixture  is  to  be  introduced  through  a  man  hole  at  the  top.  There  is  a  core  made 
towards  one  end,  to  the  figure  of  the  required  internal  form  of  the  retort,  the  other 
part  of  the  core  being  cylindrical  and  hollow,  for  the  sake  of  lightness  in  the 
pattern.  This  core  is  placed  concentrically  within  the  cylindrical  box  or  chamber, 
and  is  made  fast  thereon  by  a  stud  and  key.  to  the  end  plate  of  the  cylinder.  A 
circular  plate  acts  as  a  piston  within  the  cylinder,  sliding  over  the  core  for  the  pur-, 
pose  of  compressing  the  clay  compost;  which  piston  has  several  rods  aflixed  to  it 
whereby  mechanical  force  may  be  applied  to  drive  the  pistons  forwards  in  order  to 
condense  the  clay  into  every  part  of  the  mould,  which  is  shown  by  small  portions 
of  the  clay  oozing  out  of  what  he  calls  the  nose  piece  of  the  mould,  or  end  of  the 
intended  retort,  which  has  for  its  transverse  sectional  figure  that  of  the  letter  D  •  but 
to  this  form  the  patentee  does  not  confine  himselft  Figures  illustrative  of  the  mould 
are  given  in  Newton's  Journal,  xxvi.  Plate  II.  fin.  1. 
RHINE  WINES.     See  Wink. 

RHODIUM  is  a  metal  discovered  by  Dr.  Wollaston  in  1803,  in  the  ore  of  platinum. 
It  18  contained  to  the  amount  of  three  per  cent,  in  the  platinum  ore  of  Antioquia  in 
Colombia,  near  Barbacoas;  it  occurs  in  the  Ural  ore,  and  alloyed  with  gold  in  Mexico. 
The  palladium  having  been  precipitated  from  the  muriatic  solution  of  the  platinum  ore 
previously  saturated  with  soda  by  the  cyanide  of  mercury,  muriatic  acid  is  to  be  poured 
into  the  residuary  liauid,  and  the  mixture  is  to  be  evaporated  to  dryness,  to  expel  the 
hydrocyanic  acid,  and  convert  the  metallic  salts  into  chlorides.  The  dry  mass  is  to  be 
reduced  to  a  very  fine  powder,  and  washed  with  alcohol  of  specific  gravity  0837.  This 
solvent  takes  possession  of  the  double  chlorides  which  the  sodium  forms  with  the  plati 


1  '' 

lit :  i 


554  RICE  CLEANING. 

n„m  iridiam  copper,  and  mercury,  and  does  not  dissolve  the  double  cMoride  of  rhodium 
^JsidfurbSue^^^^^  it  in  the  fofm  of  a  powder,  of  a  fine  d-k--d  color  Th.sa^t 
h^JnT  washed  with  alcohol,  and  then  exposed  to  a  very  strong  heat,  affords  the  rhodium. 
S^t  I  bet  er  mode  of  reducing  the  metal  upon  the  small  scale,  consists  m  he^trng  the  dou^ 
We  chlSg^ntly  in  a  glass^'tube,  while  a  stream  of  hydrogeu  passes  over  it,  and  then  to 
wash  away  the  chloride  of  sodium  with  water.  ^    .     u-  u         v      ,«^«*.aH  in  a 

Rhodium  resembles  platinum  in  appearance       Any  heat  which  can  >«  pn>d«ced  ^^^^^^^ 
chemical  furnace  is  incapable  of  fusing  il ;  and  the  on  y  way  of  giving  it  cohes  ve  soad- 
itvTs  to  calcine  the  sulphuret  or  arseniuret  of  rhodium  man  ^P^"  vessel  at  a  white 
hlit  till  all  the  sulphur  or  arsenic  be  expelled.     A  bntton  may  thus  be  obtained,  some- 
what    pon«iy    having   the   color  and  lustre  of  silver.      Accordmg  to  ^  oUaston    the 
Toec  fie  gral  ty  of  rhodium  is  1 1.      It  is  insoluble  by  itself  m  any  acid ;    but  when  an 
mirofof  ft  S  certain  metals,  as  platinum,  copper,  bismuth,  or  lead    is  trea  ed  with 
iaua  reoia  The  rhodium  dissolves  along  with  the  other  metals;  but  when  alloyed  with 
S  or  lUver  it  wUl  not  dissolve  along  with  them.      It  may,  however,  be  rendered  very 
Sluble  by  miiinlit  in  the  state  of  a  fine  powder  with  chloride  of  potassium  or  sodium 
Tad  heatinnhe  mixture  to  a  dulUred  heat,  in  a  stream  of  chlorine  gas.      t  thus  forms  a 
Oriole  sal    very  soluble  in  water.     The  solutions  of  rhodium  are  of  a  beautiful  rose  color 
»wn.!.  A  nILe       In  the  dry  wav,  it  dissolves  by  heat  in  bisulphate  of  potassa ;  and 
l^eZ^s  sTlphuroul\ctd%;7in"theactof  solution!.  There  are  '-  oxY-^^^^^^^ 
Rhodium  combines  with  almost  all  the  metals;  and,  m  small  quantity,  'n^Ued  with  stee  , 
ShasTeen  supposed  to  improve  the  hardness,  closeness,  and  toughness  of  this  metal, 
rl^hief  use  atTesent  is  fo?  making  the  inalterable  nibs  of  the  so-named  rhodium  pens. 
Ri  RRO^  MANUFACTURE,  is  a  modification  of  Weaving,  which  see.       ,     ,    ^      , 
R  CE    ?f  Cifrolina    analyzed  by  Braconnot,   was  found  to  be    composed  of  starch 
85^7  of  eluteu  t^'of^r^^^^^  uncrystallizable  sugar  0-29  of  a  colourless  rancid 

fet  iL  su^et  0  laf  ofVegeW  fib;e  4-8.  of 'salts  with  potash  and  lime  bases  04,  and  6-0 
of  water. 


RIVETTING-MACfflNE. 


555 


Year. 


I 


Imported. 


1850 
1861 


1860 
1851 


Entered  for  Home 
ConsumptioD. 


cwts. 
785,451 
745,736 


qrs. 
37,150 
31,481 


Rice. 

cwte. 
435,961 
399,170 

nice  in  the  husk. 

qre. 

86,430 

28,291 


Duty  received. 


£ 
12,789 
11,013 


£ 

1821 
1414 


Rice  Paver  as  it  is  called,  on  which  the  Chinese  and  Hindoos  paint  flowers  so  prettily. 
Rtee  raper,  ^  "  »\*'*";,  '    .    .         ,,     ^rtocarpus  incisifoha  of  naturalists. 

^  "mcTSEVNING^  V^^^^^^^^^   machines  halTbe^en  contrived  for  effecting  tliis  purpose 
RlCb  ULiiiiAiNiiMij.     V  itriuua  jn»^  vf^itril  WiUon  in  1826.  may  be  regarded 

of  »hich  the  following  secured  ^X  P»*«"' *"  Mr  ^eWa  ^^^^^^  8  b,  ^j^^    „_^.^.^^_ 

husks  or  impurities  may  adhere  to  them.    A  hopper  is  set  above  to 


ever 


ever  iiui>iv3  ui  iw.|yu.  »-.>- j  _ 

and  conduct  it  down  into  the  cleansing  cy  mder.  ^roiecting  so  as  to  reach  verv 

''t^e?=\rsr;inc«nea  in  the  figure  ^^^Z^::^ ^^^ 

it  may  le  placed  also  "P"?'"' »' •'"I\^""'*\f"f„"^^id  „S'  wh»«  '>'»  """''" 
framework.  The  central  shaft  should  be  put  '"  '»P'f  '°f  ^Sli^d  by  that  ac'tion,  U 
receives  a  slow  motion  m  the  opposite  ^''f ''»»•.  „^?/;X*?„J„*"tSu,^  (shoot),  and  i. 
^^^^X^. '  Thf  ^:J^' ™:;-  b^'arW e'l  If  hanTor  by  any'  other'  eonve- 

""'SKnlists  chiefly  of  starch,  -<i '>>erefore  «nnpt  by  itse^^^ 

fa  used  in    the   cotton  factnr.es  to  '"^^^^^/^.''SfitLto  fibres   and  plates, 

':t^  t^^ulrlt^' CUtrorr^i':t^Z^^^  relmb^g  those  of 


mother-of-pearl.    When  a  decoction  of  rice  is  fermented  and  distilled,  it  affords  the 
sort  of  ardent  spirit  called  arrack  in  the  East  Indies. 
RIFLE.  See  Fire  Arms. 

RINSING  MACHINE,  is  one  of  those  ingenious  automatic  contrivances  for 
economizing  labour,  and  securing  uniformity  of  action,  now  so  common  in  the  factories 
of  Lancashire.  Fig.  1208  is  a  longitudinal  middle  section  of  an  approved  mechanism  for 
rinsing  pieces  of  calico  dyed  with  spirit  or  fancy  colours,  and  which  require  more  delicate 
treatment  than  is  compatible  with  hand-washing,  a  e  f  b  is  a  wooden  cistern,  about 
21  feet  long,  4  feet  high  at  one  end,  2  feet  at  the  other,  and  of  the  ordinary  width  of 

calico  cloth.  It  is  divided  transversely  into  a 
series  of  equal  compartments  by  partitions,  de- 
creasing in  height  from  the  upper  to  the  lower 
end,  the  top  of  each  of  them,  however,  being  an 
inch  at  least  under  the  top  of  the  enclosing  side 
at  its  line  of  junction.  Above  the  highest  end 
of  the  trough,  a  pair  of  squeezing  rollers  ia 
mounted  at  b  ;  the  lower  one  having  a  pulley 
upon  the  end  of  its  shaft,  for  turning  it,  by- 
means  of  a  band  from  one  of  the  driving-shafts 
of  the  factory  ;  and  the  upper  one  is  pressed 
down  upon  it  by  weightetl  levers  acting  on  the 
ends  of  its  axis.  The  roller  above  the  second 
highest  partition  has  also  a  pair  of  squeezing 
rollers,  with  a  weighted  lever  a  The  pieces  of 
cloth,  stitched  endwise,  being  laid  upon  a  plat- 
form to  the  right  hand  of  the  cistern,  are  intro- 
duced over  the  roller  a,  passed  down  under  the 
roller  beneath  it,  and  so  up  and  down  in  a  ser- 
pent-like path,  from  the  lowest  compartment  of 
the  cistern  to  the  uppermost,  being  drawn 
through  the  series  by  the  traction  of  the  rotatory 
roller  at  b.  While  the  long  web  is  thus  pro- 
ceeding upwards  from  a  to  b,  a  stream  of  pure 
water  is  made  to  flow  along  in  the  opposite  di- 
rection from  b  to  A,  running  over  the  top  of  each 
partition  in  a  thin  sheet.  By  this  contrivance, 
the  goods  which  enter  at  a,  having  much  loose 
colour  upon  their  surfiice,  impregnate  the  water 
strongly,  but  as  they  advance  they  continually 
get  cleaner  by  the  immersion  and  pressure  of  the 
successive  rollers,  being  exposed  to  purer  water, 
till  at  last  they  reach  the  limpid  stream,  and  are 
discharged  at  b,  perfectly  bright.  The  rinsing 
operation  may  be  modified  by  varying  the  quan- 
tity of  water  admitted,  the  speed  with  which  the 
pieces  are  drawn  through  the  cells,  or  the  pres- 
sure upon  the  series  of  top  rollers. 
RIVETTING  MACHINE  of  Fairbairn.  The  invention  of  the  rivetting  machine 
originated  in  a  turn-out  of  the  boiler-makers  in  the  employ  of  that  great  engineer  about 
fifteen  years  ago.  On  that  occasion  an  attempt  was  made  to  rivet  two  plates  together 
by  compres-oing  the  red-hot  rivet  in  the  ordinary  punching-press.  The  success  of  this 
experiment  immediately  led  to  the  construction  of  the  original  machine,  in  which  the 
moveable  die  was  forced  upon  the  rivet  by  a  powerful  lever  acted  upon  by  a  cam. 
A  short  experience  proved  the  original  machine  inadequate  to  the  numerous  require- 
ments of  the  boiler-maker's  trade,  and  the  present  form  was  therefore  adopted  about 
twelve  years  since. 

The  large  stem,  a,  is  made  of  malleable  iron,  and,  having  an  iron  strap  b  b  screwed 
round  the  base,  it  renders  the  whole  perfectly  safe  in  case  of  the  dies  coming  in  contact 
vith  a  cold  rivet,  or  any  other  hard  substance,  during  the  process.  Its  construction  also 
allows  the  workman  to  rivet  angle  iron  along  the  edges,  and  to  finish  the  corners  of 
boilers,  tanks,  and  cisterns;  and  the  stem  being  now  made  4  feet  6  inches  high,  it 
renders  the  maclime  more  extensive  in  its  application,  and  allows  of  its  rivetting  the  fire- 
box of  a  locomotive  boiler  or  any  other  work  within  the  given  depth. 

In  addition  to  these  parts,  it  has  a  broad  moving  slide,  c,  in  which  are  three  dies  corre- 
sponding  with  others  in  the  wrought  iron  stem.  By  using  the  centre  die.  everv  descrip- 
tion  of  flat  and  circular  work  can  be  riveted,  and  by  selecting  those  on  the  sides,  it  wiU 
rivet  the  corners,  and  thus  complete  vessels  of  almost  every  shape.     This  machine  is  ia 


566 


RIVETTING-MACHINE. 


I 


v:   II 


t  1 


M  ' 

1^1  ^ 


m 


iii 


ft  portable  form,  and  can  be  moved  off  raUB  with  care  to  suit  the  article  suspended  from 

%heTntroduction  of  the  knee-joint  gives  to  the  dies  a  variable  motion  and  ca^f.^^J;? 
greatest  force  to  be  exerted  at  a  proper  time,  viz.  at  the  closing  of  the  jomt  and 

finii^hinsr  of  the  head  of  the  rivet.  ,  ,       .  •    *  „*-„«,«„« 

in  other  respects  the  machine  operates  as  before,  effecting  by  an  almost  mstantaneouB 
wessure  what  is  performed  in  the  ordinary  mode  by  a  long  series  of  impacts.  Ihe 
machine  fiLes  in  the  firmest  manner,  and  completes  eight  rivets  of  f  inch  dianieter  in  • 
mbu  e  wUh  the  attendance  of  two  men  and  Uy«  to  the  plates  and  rivets  ;  ^ereas  the 
ftver^;  work  that  can  be  done  by  two  riveters,  with  one  «  holder  on"  and  a  boy  is  40* 


ROPE-MAKING. 


557 


inch  rivets  per  hour ;  the  quantity  done  in  two  cases  being  in  the  proportion  of  40  to  480, 
or  as  1  to  12,  exclusive  of  the  saving  of  one  man's  labour.  The  cylinder  of  an  ordinary 
locomotive  engine  boiler  8  feet  6  inches  long  and  3  feet  diameter  can  be  riveted  and  the 
plates  fitted  completely  by  the  machine  in  4  hours ;  whilst  to  execute  the  same  work  by 
hand  would  require  with  an  extra  man  twenty  hours.  The  work  produced  by  the  machine 
is  likewise  of  a  superior  kind  to  that  made  in  the  ordinary  manner ;  the  rivets  being  found 
stronger,  and  the  boilers  more  free  from  leakage,  and  more  perfect  in  every  respect.  Tlie 
riveting  is  done  without  noise,  and  thus  is  almost  entirely  removed  the  constant  deafening 
clamour  of  the  boiler-maker's  hammer. 

ROCKETS.  M.  de  Montgery,  captain  of  a  frigate  in  the  French  service,  has  written  a 
Traite  mr  les  Fmees  de  Gtierre,  in  which  he  discusses  the  merits  of  the  Congreve  rockets,  and 
describes  methods  of  imitating  them.  As  the  subject  of  military  projectiles  is  foreign  to 
this  Dictionary,  I  refer  my  readers  to  the  above  work,  which  is  commended  by  the  editor 
of  the  D'ctionnaire  Technologique. 

ROLLING-MILL.     See  Iron,  Mint,  and  Plated  Manufacture. 

ROOFING,  ASPHALTK  Patent  asphalte  roofing  felt,  particulariy  applicable  for 
warm  climates.  It  is  a  non-conductor.  It  is  portable,  being  packed  in  rolls,  and  not 
being  liable  to  damage  in  carriage,  it  effects  a  saving  of  half  the  timber  usually  required. 
It  can  be  easily  applied  by  any  unpractised  person.  From  its  lightness,  weighing  only 
about  42  lbs.  to  the  square  of  100  feet,  the  cost  of  cartage  is  small.  The  felt  can  be  laid 
on  from  gable  to  gable,  or  across  the  roof  from  eaves  to  eavea  It  is  essential  that  it 
should  be  stretched  tight  and  smooth,  overlapping  full  one  inch  at  the  joinings,  and 
closely  nailed  through  the  overlap,  with  twopenny  fine  clout  nails,  (heated  in  a  shovel 
and  thrown  when  hot  into  grease  to  prevent  rust,)  about  1^  inches  apart,  but  copper 
nails  are  preferable. 

The  whole  roof  must  have  a  good  coating  of  coal-tar  and  lime,  (about  two  gallons  of 
the  former  to  six  pounds  of  the  latter),  well  boiled  together,  kept  constantly  stirring 
while  boiling,  and  put  on  hot  with  a  common  tar  mop,  and  while  it  is  soft  some  coarse 
sharp  sand  may  be  sifted  over  it  The  coating  must  be  renewed  every  fourth  or  fifth 
year,  or  more  or  less  frequently  according  to  the  climate.  The  gutters  should  be  made 
of  two  folds,  one  over  the  other,  cemented  together  with  the  boiling  mixture. 

ROPE-MAKING.  The  fibres  of  hemp  which  compose  a  rope,  seldom  exceed  in  length 
three  feet  and  a  half,  at  an  average.  They  must,  therefore,  be  twined  together  so  as  to 
unite  them  into  one ;  and  this  union  is  effected  by  the  mutual  circumtorsion  of  the  two 
fibres.  If  the  compression  thereby  produced  be  too  great,  the  strength  of  the  fibres  at  the 
points  where  they  join  will  be  diminished ;  so  that  it  becomes  a  matter  of  great  consequence 
to  give  them  only  such  a  degree  of  twist  as  is  essential  to  their  union. 

The  first  part  of  the  process  of  rope-making  by  hand,  is  that  of  spinning  the  yarns  or 
threads,  which  is  done  in  a  manner  analogous  to  that  of  ordinary  spinning.  The  spin- 
ner carries  a  bundle  of  dressed  hemp  round  his  waist ;  the  two  ends  of  the  bundle  being 
assembled  in  front.  Having  drawn  out  a  proper  number  of  fibres  with  his  hand,  he 
twists  them  with  his  fingers,  and  fixing  this  twisted  part  to  the  hook  of  a  whirl,  which 
is  driven  by  a  wheel  put  in  motion  by  an  assistant,  he  walks  backwards  down  the  rope> 
walk,  the  twisted  part  always  serving  to  draw  out  more  fibres  from  the  bundle  round 
his  waist,  as  in  the  flax-spinning  wheel.  The  spinner  takes  care  that  these  fibres  are 
equably  supplied,  and  that  they  always  enter  the  twisted  parts  by  their  ends,  and  never 
by  their  middle.  As  soon  as  he  has  reached  the  termination  of  the  walk,  a  second  spin- 
ner takes  the  yarn  off  the  whirl,  and  gives  it  to  another  person  to  put  upon  a  reel,  while 
he  himself  attaches  his  own  hemp  to  the  whirl  hook,  and  proceeds  down  the  walk.  "When 
the  person  at  the  reel  begins  to  turn,  the  first  spinner,  who  has  completed  his  yarn,  holdg 
it  firmly  at  the  end,  and  advances  slowly  up  the  walk,  while  the  reel  is  turning,  keeping 
it  equally  tight  all  the  way,  till  he  reaches  the  reel,  where  he  waits  till  the  second  spinner 
takes  his  yarn  off  the  whirl  hook,  and  joins  it  to  the  end  of  that  of  the  first  spinner,  in 
order  that  it  may  follow  it  on  the  reel. 

The  next  part  of  the  process  previous  to  tarring,  is  that  of  warping  the  yarns,  or 
stretching  them  all  to  one  length,  which  is  about  200  fathoms  in  full-length  rope-grounds, 
and  also  in  putting  a  slight  turn  or  twist  into  them. 

The  third  process  in  rope-making,  is  the  tarring  of  the  yarn.  Sometimes  the  yams 
are  made  to  wind  off  one  reel,  and,  having  passed  through  a  vessel  of  hot  tar,  are  wound 
upon  another,  the  superfluous  tar  being  removed  by  causing  the  yarn  to  pass  through  a 
hole  surrounded  with  spongy  oakum ;  but  the  ordinary  method  is  to  tar  it  in  skeins  or 
hanks,  which  are  drawn  by  a  capstan  with  a  uniform  motion  through  the  lar-keltle.  In 
this  process,  great  care  must  be  taken  that  the  tar  is  boiling  neither  too  fast  nor  too  slow. 
Yarn  for  cables  requires  more  tar  than  for  hawser-laid  ropes ;  and  for  standing  and  run- 
ning rigging,  it  requires  to  be  merely  well  covered.  Tarred  cordage  has  been  found  to 
be  weaker  than  what  is  untarred,  when  it  is  new ;  but  the  tarred  rope  is  not  so  easily 
injured  by  immersion  in  water. 


*IJ 


ti 


'M 


II: 


558 


ROPE-MAKING. 


EOPE-MAKING. 


The  last  part  of  the  process  of  rope-making,  is  to  lay  the  cordage.  For  this  pnrpora 
two  or  more  yarns  are  attached  at  one  end  to  a  hook.  The  hook  is  then  turned  the  con- 
trary way  from  the  twist  of  the  individual  yarn,  and  thus  forms  what  is  called  a  strand. 
Three  strands,  sometimes  four,  besides  a  central  one,  are  then  stretched  at  length,  and 
attached  at  one  end  to  three  contiguous  but  separate  hooks,  but  at  the  other  end  to  a 
single  hook ;  and  the  process  of  combining  them  together,  which  is  eflected  by  turning 
the  single  hook  in  a  direction  contrary  to  that  of  the  other  three,  consists  in  so  regulating 
the  progress  of  the  twists  of  the  strands  round  their  common  axis,  that  the  three  strands 
receive  separately  at  their  opposite  ends  just  as  much  twist  as  is  taken  out  of  them  by 
their  twisting  the  contrary  way,  in  the  process  of  combination. 

Large  ropes  are  distinguished  into  two  main  classes,  the  cable-laid  and  hawser-laid. 
The  former  are  composed  of  nine  strands,  namely,  three  great  strands,  each  of  these  con- 
sisting of  three  smaller  secondary  strands,  which  are  individually  formed  with  an  equal 
number  of  primitive  yarns.  A  cable-laid  rope  eight  inches  in  circumference,  is  made  up 
of  333  yarns  or  threads,  equally  divided  among  the  nine  secondary  strands.  A  hawser-latd 
rope  consists  of  only  three  strands,  each  composed  of  a  number  of  primitive  yarns,  propor- 
tioned to  the  size  of  the  rope ;  for  example,  if  it  be  eight  inches  in  circumference,  it  may 
have  414  yarns,  equally  divided  among  three  strands.  Thirty  fathoms  of  yarn  are  reck- 
oned equivalent  in  length  to  eighteen  fathoms  of  rope  cable-laid,  and  to  twenty  fathoms 
hawser-laid.  Ropes  of  from  one  inch  to  two  inches  and  a  half  in  circumference  are  usu- 
ally hawser-laid  ;  of  from  three  to  ten  inches,  are  either  hawser  or  cable-laid  j  but  when 
more  than  ten  inches,  they  are  always  cable-laid. 

Every  hand-spinner  in  the  dock-yard  is  required  to  spin,  out  of  the  best  hemp,  six 
threads,  each  160  fathoms  long,  for  a  quarter  of  a  day's  work.  A  hawl  of  yam,  in  the 
warping  process,  contains  336  threads. 

The  following  are  Captain  Huddarl's  improved  principles  of  the  fope  manufacture  ^^ 

1.  To  keep  the  yarns  separate  from  each  other,  and  to  draw  them  from  bobbins  revolT- 
ing  upon  skewers,  so  as  to  maintain  the  twist  while  the  strand  or  primarj'  cord  is  forming. 

2.  To  pass  them  through  a  register,  which  divides  them  by  circular  shells  of  holes; 
the  number  in  each  concave  shell  being  conformable  to  the  distance  from  the  centre  of 
the  strand,  and  the  angle  which  the  yarns  make  with  a  line  parallel  to  it,  and  which  gives 
them  a  proper  position  to  enter. 

3.  To  employ  a  tube  for  compressing  the  strand,  and  preserving  the  cylindrical  figure 
of  its  surface. 

4.  To  use  a  gauge  for  determining  the  angle  which  the  yarns  in  the  outside  shell 
make  with  a  line  parallel  to  the  centre  of  the  strand,  when  registering ;  because  accord- 
ing to  the  angle  made  by  the  yams  in  this  shell,  the  relative  lengths  of  all  the  yams  in 
the  strand  will  be  determined. 

5.  To  harden  up  the  strand,  and  thereby  increase  the  angle  in  the  outside  shell;  which 
compensates  for  the  stretching  of  the  yarns,  and  the  compression  of  the  strands. 

A  great  many  patents  have  been  obtained,  and  worked  with  various  degrees  of  success, 
for  r;iaking  ropes.  Messrs.  Cartwright,  Fothergill,  Curr,  Chapman,  fialfour,  and  Hud- 
dart,  have  been  ttie  most  conspicuous  inventors  in  this  country ;  but  the  limits  of  thii 
work  preclude  us  doing  justice  to  their  respective  merits. 

All  the  improvements  in  the  manufacture  of  cordage  at  present  in  use,  either  in  her 
Majesty's  yards  or  in  private  rope-grounds,  owe  their  superiority  over  the  old  method 
of  making  cordage  to  Captain  Huddart's  invention  of  the  register  plate  and  lube. 

Mr.  Balfour  took  out  a  patent  for  the  manufacture  of  cordage  about  a  month  before 
Captain  Huddart;  but  the  formation  of  his  strand  was  to  be  accomplished  by  what  he 
called  a  top  minor  (in  the  form  of  a  common  top,  with  pins  to  divide  the  yarns),  which 
upon  trial  could  not  make  cordage  so  good  as  by  the  common  mode.  On  seeing  Cap- 
tain Huddart's  specification,  Mr.  Balfour,  five  years  after,  procured  another  patent,  ia 
which  he  included  a  plate  and  tube,  but  which  was  not  sufficiently  correct,  and  ex- 
perience in  the  navy  proved  the  insufficiency  of  the  cordage.  Captain  Huddart'& 
plate  and  tube  were  then  adopted  in  the  king's  yards,  and  he  gave  his  assistance  for  the 
purpose. 

Captain  Huddart  then  invented  and  took  a  patent  for  a  machine,  which  by  registering 
the  strand  at  a  short  length  from  the  tube,  and  winding  it  up  as  made,  preserved  a  uni- 
formity of  twist,  or  ans^le  of  formation,  from  end  to  end  of  the  rope,  which  cannot  be  ac- 
complished by  the  method  of  forming  the  strands  down  the  ground,  where  the  twist  ift 
communicated  from  one  end  to  the  other  of  an  elastic  body  upwards  of  300  yards  in 
length.  This  registering-machine  was  constructed  with  such  correctness,  that  when 
some  were  afterwards  required,  no  alteration  could  be  made  with  advantage  by  the  most 
skilful  and  scientific  mechanic  of  that  day,  Mr.  Rennie.  Thus  the  cold  register  was  car- 
ried to  the  greatest  perfection. 

A  number  of  yarns  cannot  be  put  together  in  a  cold  state,  without  considerable 
vacancies,  into  which  water  may  gain  admission ;  Captain  Huddart,  therefore,  formed  the 


559 


yams  into  a  strand  immediately  as  they  came  from  the  tar-kettle,  which  he  was  enabled 
to  do  by  his  registering-machine,  and  the  result  was  most  satisfactory.  This  combination 
of  yarns  was  found  by  experiment  to  be  14  per  cent,  stronger  than  the  cold  register;  it  con- 
stituted a  body  of  hemp  and  tar  impervious  to  water,  and  had  great  advantaee  over  any 
other  cordage,  particularly  for  shrouds,  as  after  they  were  settled  on  the  masl-head,  and 
properly  set  up,  they  had  scarcely  any  tendency  to  stretch,  effectually  secured  the  mast, 
and  enabled  the  ship  to  carry  the  greatest  press  of  sail. 

In  order  more  effectually  to  obtain  correctness  in  the  formation  of  cables  and  large 
cordage.  Captain  Huddart  constmcted  a  laying-machine,  which  has  carried  his  inventions 
in  rope-making  to  the  greatest  perfection,  and  which,  founded  on  true  mathematical  prin- 
ciples, and  the  most  laborious  calculations,  is  one  of  the  noblest  monuments  of  mechanical 
ability  since  the  improvement  of  the  steam-engine  by  Mr.  Watt.  By  this  machine,  the 
strands  receive  that  degree  of  twist  only  which  is  necessary,  and  are  laid  at  any  angle 
with  the  greatest  regularity ;  the  pressure  is  regulated  to  give  the  required  elasticity,  and 
all  parts  of  the  rope  are  made  to  bear  equally.  In  no  one  instance  has  a  rope  or  cable 
thus  formed  been  found  defective  in  the  lay,  or  stiff,  or  difficult  to  coil. 

Such  a  revolution  in  the  manufacture  of  cordage  could  not  be  accomplished  without 
great  expense,  as  the  works  at  Limehouse  fully  testify ;    and  considerable  opposition 
necessarily  arose.     Captain  Huddart's  first  invention  was,  however,  generally  adopted 
as  soon  as  the  patent  expired  ;    and  experience  has  established  the  great  importance  of 
his  subsequent  improvements. 

His  cordage  has  been  supplied  in  large  quantities  to  her  Majesty's  navy,  and  has  re- 
ceived the  most  satisfactory  reports. 

The  following  description  of  one  of  the  best  modern  machines  for  making  ropes  on 
Captain  Huddart's  plan,  will  gratify  the  intelligent  reader. 

J'lig.  1211  exhibits  a  side  elevation  of  the  tackle-board  and  bobbin-frame  at  the  head 


T 

of  the  ropcLV,  and  also  of  the  carriage  or  rope-machine  in  the  act  of  hanlin*'  oat^nd 
twisting  the  strands.  ^  ® 

i^tg.l212is  a  front  elevation  of  the  carriage. 

IVg.  1213is  a  yarn-guide,  or  board,  or  plate,  with  perforated  holes  for  the  yams  to  pan 
through  before  entering  the  nipper.  ^^ 

Figs.  1214  and  1215  are  side  and  front  views  of  the  nipper  for  pressing  the  rop«i. 

a  is  he  frame  for  containing  the  yarn  bobbins.  The  yarns  are  brought  from  tbe 
frame,  and  pass  through  a  yarn-guide  at  b.  c  is  a  small  roller,  under  which  the  rone- 
yarns  pass ;  they  are  then  brought  over  the  reel  rf,  and  through  another  yarn-guide  e 
after  which  they  enter  the  nippers  at  v,  and  are  drawn  out  and  formed  into  strands  by 
the  carriage.  The  roller  and  reel  may  be  made  to  traverse  up  and  down,  so  as  to  regulati 
the  motion  of  the  yarns.  ^ 

The  carriage  runs  on  a  railway.  /,/,  is  the  frame  of  the  carriage ;  g,  g,  are  the  smaU 
wheels  on  which  it  is  supported  ;    k,  k,  is  an  endless  rope,  reaching  from  the  head  to 


1212 


the  bottom  of  the  railway,  and  is  driven  by  a  steam-engine; 
wi,  nj,  IS  a  wheel  with  gubs  at  the  back  of  it,  over  which  the 
endless  rope  passes,  and  gives  motion  to  the  machinery-  of  the 
oarriage.  «,  is  the  ground  rope  for  taking  out  the  carriage, 
as  will  be  afterwards  described.  On  the  shaft  of  wi,  wi,  ^e 
two  bevel  wheels  3,  3,  with  a  shifting  catch  between  them: 
these  bevel  wheels  are  loose  upon  the  shaft,  but  when  the 
catch  rs  put  into  either  of  them,  this  last  then  keeps  motion 
with  the  slMft,  while  the  other  runs  loose.  One  of  these 
wheels  serves  to  communicate  the  twist  to  the  strand  in 
drawing  out ;  the  other  gives  the  opposite  or  after  turn  to 
the  rope  in  closing.  4,  4,  is  a  lever  for  shifting  the  catch 
accordingly.    6,  is  a  third  bevel  wheel,  which  i  eceives  its 


I'^ti  I 


560 


ROPE-MAKING. 


ROPE-MAKING. 


Ml 


H 


,!■'  ; 


li!   1    ■ 


1213 


w^ 


1214( 


D 


1215 


!    i 


.  motion  from  either  of  the  other  two,  and  communicates  the 
same  to  the  two  spur  wheels  6,  6,  by  means  of  the  shaft  x. 
These  can  be  shifted  at  pleasure ;  so  that  by  applying  wheels 
of  a  greater  or  less  number  of  teeth  above  and  beneath,  the 
twist  given  to  the  strands  can  be  increased  or  diminished 
accordingly.  The  upper  of  these  two  communicates  motion, 
by  means  of  the  shaft  o,  to  another  spur  wheel  8,  which  working  in  the  three  pinions 
above,  9,  9,  gives  the  twist  to  the  strand  hooks. 

The  carriage  is  drawn  out  in  the  following  manner.  On  the  end  of  the  shaft  of  m,  w, 
is  the  pinion  3,  which,  working  in  the  large  wheel  b,  gives  motion  to  the  ground-rope 
shaft  upon  its  axis.  In  the  centre  of  this  shaft  is  a  curved  pulley  or  drum  /,  round 
which  the  ground-rope  takes  one  turn.  This  rope  is  fixed  at  the  head  and  foot  of  the 
ropery  ;  so  that  when  the  machinery  of  the  carriage  is  set  a-going  by  the  endless  rope  k, 
k,  and  gives  motion  to  the  ground-rope  shaft,  as  above  described,  the  carriage  will  neces- 
sarily move  along  the  railway ;  and  the  speed  may  be  regulated  either  by  the  diameter  of 
the  circle  formed  by  the  gubs  on  the  wheel  »n,  tm,  or  by  the  number  of  teeth  in  the  pinion 
3.  At  T,  is  a  small  roller,  merely  for  preventing  the  ground- rope  from  coming  up  among 
the  machinery.  At  the  head  of  the  railway,  and  under  the  tackle-board,  is  a  wheel  and 
pinion  z,  with  a  crank  for  tightening  the  ground-rope.  The  fixed  machinery  at  the  head, 
for  hardening  or  tempering  the  strands,  is  similar  to  that  on  the  carriage,  with  the  ex- 
ception of  the  ground-rope  gear,  which  is  unnecessary.  The  motion  is  communicated  by 
another  endless  rope  (or  short  band,  as  it  is  called,  to  distinguish  it  from  the  other), 
which  passes  over  gubs  at  the  back  of  the  wheel  1,  1. 

When  the  strands  are  drawn  out  by  the  carriage  to  the  requisite  length,  the  spur  wheels 
3,  R,  are  put  out  of  gear.  The  strands  are  cut  at  the  tackle-board,  and  fixed  to  the 
hooks  1,  1,  1 ;  after  which  they  are  hardened  or  tempered,  being  twisted  at  both  ends. 
When  this  operation  is  finished,  three  strands  are  united  on  the  large  hook  h,  the  top  put 
in,  and  the  rope  finished  in  the  usual  w^ay. 

In  preparing  the  hemp  for  spinning  and  ordinary  thread  or  rope  yarn,  it  is  only  heckled 
over  a  large  keg  or  clearer,  until  the  fibres  are  straightened  and  separated,  so  as  to  run 
freely  in  the  spinning.  In  this  case,  the  hemp  is  not  stripped  of  the  tow,  or  cropped,  unless 
it  is  designed  to  spin  beneath  the  usual  grist,  which  is  about  20  yarns  for  the  strand 
of  a  three-inch  strap-laid  rope.  The  spinning  is  still  performed  by  hand,  being  found 
not  only  to  be  more  economical,  but  also  to  make  a  smoother  thread,  than  has  yet  been 
effected  by  machinery.  Various  ways  have  been  tried  for  preparing  the  yams  for 
tarring.  That  which  seems  now  to  be  most  generally  in  use,  is,  to  warp  the  yarns  upon 
the  stretch  as  they  are  spun.  This  is  accomplished  by  having  a  wheel  at  the  foot,  as 
well  as  the  head  of  the  walk,  so  that  the  men  are  able  to  spin  both  up  and  down,  and 
also  to  splice  their  threads  at  both  ends.  By  this  means,  they  are  formed  into  a  haul, 
resemb  ing  the  warp  of  a  common  web,  and  a  little  turn  is  hove  into  the  haul,  to  pre- 
serve it  from  getting  foul  in  the  tarring.  The  advantages  of  warpins:  from  the  spin- 
ners, as  above,  instead  of  winding  on  winches,  as  formerly,  are,  1st,  the  saving  of  this 
last  operation  altogether;  2dly,  the  complete  check  which  the  foreman  has  of  the 
quantity  of  yarn  spun  in  the  day ;  Sdly,  that  the  quality  of  the  work  can  be  subjected 
to  the  minutest  inspection  at  any  time.  In  tarring  the  yarn,  it  is  found  favorable  to 
the  fairness  of  the  strip,  to  allow  it  to  pass  around  or  under  a  reel  or  roller  in  the 
bottom  of  the  kettle  while  boiling,  instead  of  coiling  the  yarn  in  by  hand.  The  tar  is  then 
pressed  from  the  yarn,  by  means  of  a  sliding  nipper,  with  a  lever  over  the  upper  part,  and 
to  the  end  of  which  the  necessary  weight  is  suspended.  The  usual  proportion  of  tar  ia 
ordinary  ropes,  is  something  less  than  a  fifth.  In  large  strap-laid  ropes,  which  are  ne- 
cessarily subjected  to  a  greater  press  in  the  laying  of  them,  the  quantity  of  tar  can  scarcely 
exceed  a  sixth,  without  injuring  the  appearance  of  the  rope  when  laid. 

For  a  long  period,  the  manner  of  laying  the  yams  into  ropes,  was  by  stretching  the 
haul  on  the  rope-ground,  parting  the  number  of  yarns  required  for  each  strand,  and 
•wisting  the  strands  at  both  ends,  by  means  of  hand-hooks,  or  cranks.     It   will  be 
obvious  that  this  method,  especially  in  ropes  of  any  considerable  size,  is  attended  with 
serious  disadvantages.     The  strand  must  always  be  very  uneven ;  but  the  principal  dis- 
idvantage,  and  that  which  gave  rise  to  the  many  attempts  at  improvement,  was,  that 
She  yarns  being  all  of  the  same  length  before  being  twisted,  it  fc^Jlowed,  when  the  rope 
was  finished,  that  while  those  which  occupied  the  circumference  of  the  strand  were  per- 
fectly tight,  the  centre  yarns,  on  the  other  hand,  as  they  were  now  greatly  slackened  by 
the  operation  of  hardening  or  twisting  the  strands,  would  actually  bear  little  or  no  part 
•>f  the  strain  when  the  rope  was  stretched,  until  the  foimer  gave  way.      The  method 
lisplayed  in  the  preceding  figures  and  description,  is  among  the  latest  and  most 
improved.    Every  yarn  is  given  out  from  the  bobbin  frame  as  it  is  required  in  twist* 
mg  the  rope ;  and  the  twist  communicated  in  the  out-going  of  the  carriage,  can  be  in- 
creased or  diminished  at  pleasure.    In  order  to  obtain  a  smooth  and  well-filled  strand, 


It  18  nectary  also,  in  prmmg  the  yarns  through  the  upper  board,  to  proportion  the 
number  of  centre  to  that  of  outside  yams.  In  ordina^r  sfzed  ropes,  the  strand  seems  to 
have  the  fairest  appearance,  when  the  outside  yarns  form  from  fd  to  fths  of  the  whole 
strandF'  '"         ^  ^"^'"^  ^""^^  ^^  ^^"^  ""^""'^^  ""  drawing  out  and  forming  the 

10?*  ^?y'"f/a^les,  torsion  must  be  given  botli  behind  and  before  the  laying  top.  i^«. 
IZ1»,  17,  18.  represent  the  powerful  patent  apparatus  employed  for  this  purpose,    j^ia 


1216 


:t1np;^e?e'n?JL7lT^  ^---ta.  beam  ..  .,  and  bearing 

bobbins  \!r  reels  round  y^^^thr^rjJ2r^'  .  °'  J"'  ^'^  ^'^'^  «^  *^«  '^^ee  gr^ 
These  are  drawn  up  byTT ro^i^^f  ^T^J? ^^T^'  ^^^^  ^^^««"  ^'^  ^«^"d. 
over  the  three  guije  pulWs  k  k  T  towardf^h!  1      "^'"f  '*'"^'''  ''  ''  '>  ^^^^^  P«>ceed 
the  tube  o.  to  be  wounLiSi  tWbie  rleTo      '^li^f'"^  top  m  and  finally  pass  through 
do  not  revolve  about  the  f^p^lkrV^  a  im-n?.  -'^T!  ^^  ^h"^'^^  ^^^^'  «»  h.  h. 
its  own  shaft  q,  which  is  steadied  hf«K^°  ^/^'  ^"*  ^^^^  ^^^"^  revolves  roimd 
bottom.     The   three   ^bbins  are   n^aced  ^If'"'^  "^^l'^  f  ^'  *"^  ^  <^"i^  Btep  at  ite 
JBceives  a  rotatory  motiorupon  its^iwrom  Z7£X  "/  ^''  ^1?^^  ^P^'*'  ^^  each 
by  the  common  central  spur^  wheel  o     Th^s  Li     rtu  '??'  ^^^^^  «'  ^^^^^  "  driven 
proper  degree  of  twist  put  into  it  inoJ^^rJr       ^^.^^^^  three  secondaiy  cords  has  a 
suitable  digree  of  twist  ki  an  oppos^^^^  ^re^Tl''nJ^^:^'  '^^'^^^'  ''  ^^'^'^^  Setting  a 
o,  G,  round  two  pivot.,  the  one  under  the  nS/        ^J^  f^^olution  of  the  frame  or  c%6 
has  thus,  like  the  bobbins  h,  h,  two  2vemen2  ^*^"'  "^^''  ^-    ^h^  '^^ 

that  upon  its  axis,  produced  by  thLaSbnTfJ^o'    a^  »»  common  with  its  frame,  and 
<«e  of  its  ends,  and  the  pulley  e'  above  tscentr'^^^^^^  *^«  pulley  e,  upon 

the  bevel  mill-gearing  pf p  p  as  alsoX  nL  ""^  notation.     The  pulley  e  is  driven^y 

'¥  -g.'.//l216^hich  belr^fhe"^^^^  -.in//l2li  istheplaceo?= 

view  of  the  bobbin  h,  to  show  the  worm  of  p??i       P""^^'  "^  ^  ^-     ^^>-  ^217  is  an  end 
wo  snail-toothed  whUls,  upl  theTdTof  the  fwnTT  \?^'^^'  ^^'^'  ^^'^^'^^  ^'^  '^^ 

them.    The  upright  shafts  of  j,/  receive  tbp1r^t•'1."'''"''^V  ''  ^*^^^^  «^'^«  *«  *««•«» 
re  wi  J,  J,  receive  their  motion  from  pulleys  and  cords  near  their 


.it, .11  i 


I 


562 


ROPE-MAKING. 


bottom.  Instead  of  these  puDeys,  and  the  others  k,  «',  bevel-T^heel  geenng  .haa  been 
s^^tu^ted  with  advantage,  not' being  liable  to  slip,  like  the  pulley-band  mechamsny 
Th?  axis  of  the  great  reel  is  made  twice  the  length  of  the  bobbin  d,  in  order  to  allow  of 
the  latter  moving  from  right  to  left,  and  back  again  alternately,  in  winding  on  thecable 
with  uniformity  as  it  is  laid.    The  traverse  mechanism  of  this  part  is,  for  the  sake  oi 

TwSiar&'oTe  W  obtained  a  patent  in  May,  1833,  for  an  improve 

ment' adapted  to  the  ordinary  machines  employed  for  twisting  hempen  yarns  into 
strands,  Wording,  it  is  said,  a  simpler  and  more  eligible  mode  of  accomplishing  that 
object,  and  also  of  laying  the  strands  together  than  has  been  hitherto  effected  by 
machinerv  The  yarns  spun  from  the  fibres  of  hemp  are  wound  upon  bobbins  and 
Jhese  bobbins  are  mounted  upon  axles,  and  hung  in  the  frame  of  the  machine,  as  shown 
in  the  elevation,  Ha.  1219,  from  which  bobbins  the  several  ends  of  yarn  are  passed  upwaids 
tSroucrh  slaS^^^  by  the  rotation  of  which  tubes,  and  of  the  carriages  in  which 

th^  febbbs  are  suspended,  the  yarns  become  twisted  into  strands,  and  also  the  strands 

are  laid  so  as  to  form  ropes.  .  .  x.       i.        ^e 

His  improvements  consist,  first,  in  the  application  of  three  or  more  tubes,  two  of 
wWch  are  shown  in  iq.  1219,  placed  in  inclined  positions,  so  as  to  receive  the  strands 
Trnmedirely  Xve  t^^^^^  «,  -,  and  nearly'in  a  line  with  a,  the  point  of  closing 

"ng  the  rope.  B^nd  b^,  are  opposite  side  views;  B^  ^V'fjrt'f^r  th^'tu^a 
section  of  the  same.  He  does  not  claim  any  exclusive  right  of  patent  for  the  tubes 
themselves,  but  only  for  their  fonn  and  angular  position.  ^     i  oi  a    f n  P«rh 

Secondly,  in  attaching  two  common  flat  sheaves,  or  pulleys,  c,  o,  ^.  1219.,  to  eacn 


^SM&MmmmmM: 


of  the  said  tubes  nearly  round  which  each  strand  is  lapped  or  coiled,  to  prevent  it  from 
afippL  ^  sW  Tnthe  section  b^  The  said  sheaves  or  pulleys  are  connected  by  a 
tw^'or'nte  wheel  n.  loose  upon  6,  6.  the  main  or  upright  axle ;  B.|. »«  \^f^^ 
wheel  upon  each  tube,  working  into  the  said  crown  or  centre  wheel,  and  fixed  upon  the 

^Tk>  a  tTothet  t  sp^r  whed,  fixed  also  upon  each  of  the  loose  boxes  ^^^^^^^^^ 
into  a  smaller  wheel  o,  upon  the  axis  2,  of  each  tube ;  h,  is  a  bevel  whee  faxed  upon  the 
Sme  iTwith  G,  and  woAing  into  another  bevel  wheel  J,  fixed  upon  the  cross  axle  3 
Tf  eac^tube;  k,  is  a  spur  wheel  attached  to  the  same  axis  with^  at  the  opposite  end 
^/working  into  i,  another  spur  wheel  of  the  same  size  upon  each  of  the  tubes.  By 
wheels  thS"  arranged  and  connected  with  the  sheaves  or  pulleys,  as  above  descnbed, 
TpeXtly  equal  strain  or  tension  is  put  upon  each  strand  as  drawn  forward  over  the 
pulley  r 


ROPE-MAKING. 


668 


^  ,^ri/'  r  invention  consists  in  the  introduction  of  change  wheels  if .  ic,  m  m 
Jig  1219.,  for  putting  the  forehard  or  proper  twist  into  each  strand  before  the  rop^  is 
laid  ;  this  is  effected  by  smaU  spindles  on  axles  4,  4,  placed  paraUel  with  the  line  of  each 
tube  B, 

Upon  the  lower  end  of  each  spindle  the  bevel  wheels  n,  n,  are  attached,  and  driven 
t>y  other  bevel  wheels  o,  o,  fixed  immediately  above  each  press-block  a,  a.  On  the 
top  end  of  each  spindle  or  axle  4,  4,  is  attached  one  of  the  change  wheels,  working 
into  the  other  change  wheel  fixed  upon  the  bottom  end  of  each  of  the  tubes, 
whereby  the  forehard  or  proper  twist  in  the  strands  for  all  sizes  of  ropes,  is  at  once 
attained,  by  simply  changing  the  sizes  of  those  two  last  described  wheels,  which  can  be 
very  readily  effected,  from  the  manner  in  which  they  are  attached  to  the  lubes  b,  b,  and 
4,  4.  '    ' 

From  the  angular  position  of  the  tubes  towards  the  centre,  the  strands  are  nearly  in 
contact  at  their  upper  ends,  where  the  rope  is  laid,  immediately  below  which  the  forehard 
or  proper  twist  is  given  to  the  strands. 

Fourthly,  in  the  application  of  a  press-block  p,  of  metal,  in  two  parts,  placed 
directly  above  and  close  down  to  where  the  rope  :'s  laid  at  a,  the  inside  of  which  is 
polished,  and  the  under  end  is  bell-mouthed  ;  to  prevent  the  rope  from  being  chafed  in 
entering  it,  a  sufficient  grip  or  pressure  is  put  upon  the  rope  by  one  or  two  levers  and 
weights  5,  5,  acting  upon  the  press-block,  so  as  to  adjust  any  t; ifling  irregularity  in  the 
strand  or  m  the  laying ;  the  inside  of  which  being  polished,  gives  smoothness,  and  by 
the  said  levers  and  weights,  a  proper  tension  to  Ihe  rope,  as  it  is  drawn  forward  through 
the  press-block.  By  the  application  of  this  block,  ropes  may  be  made  at  once  properly 
stretched,  rendering  them  decidedly  preferable  and  extremely  advantageous,  particularly 
for  shipping,  inclined  planes,  mines,  &c. 

The  preceding  description  includes  the  whole  of  Mr.  Norvell's  improvements;  the 
remaining  parts  of  the  machine,  being  similar  to  those  now  in  use,  may  be  briefly 
described  as  follows:— A  wheel  or  pulley  c,  is  fixed  independently  of  the  machine,  over 
Which  the  rope  passes  to  the  drawing  motion  represented  at  the  side ;  d,  d,  is  a  grooved 
wheel,  round  which  the  rope  is  passed,  and  pressed  into  the  groove  by  means  of  the 
lever  and  weight  e,  e,  acting  upon  the  binding  sheaf/,  to  prevent  the  rope  from  slipping. 
After  the  rope  leaves  the  said  sheave,  it  is  coiled  away  at  pleasure,    g,  g,  are  two  chan-e 
wheels,  for  varying  the  speed  of  the  grooved  wheel  rf,  rf,  to  answer  the  various  sizes  li 
ropes;  A,  is  a  spiral  wheel,  driven  by  the  screw  fc,  fixed  upon  the  axle  Z;  »n,  is  a  band- 
wheel,  which  IS  driven  by  a  belt  from  the  shaft  of  the  engine,  or  any  other  communicating 
power ;  «,  w,  is  a  friction  strap  and  striking  clutch.     The  axle  q,  is  driven  by  two  change 
wheels />,p;  by  changing  the  sizes  of  those  wheels,  the  different  speeds  of  the  drum  r/r, 
for  any  sizes  of  ropes,  are  at  once  effected. 
The  additional  axle  «,  and  wheels  /,  t,  shown  in  fi^,  1220,  are  applied  occasionally  for 


reversing  the  motion  of  the  said  drums,  and  making  what  is  usually  termed  left-hand 
ropes;  r^  fig,.  1219.,  1220,  show  a  bevelled  pinion,  "driving  the  main  crown  whiir« 
which  wheel  carries  and  gives  motion  to  the^^drums  r,  e  ;  «,  «,,  is  a  fixed  ^s^n  wheel' 
which  gives  a  reverse  motion  to  the  drums,  as  they  revolve  round  the  s^me,  by  me^s  of 
the  mtervemng  wheels  x  x,x,  whereby  the  reverse  or  retrograding  motioi  is  prXed 
and  which  gives  to  the  strands  the  r  ght  twist  The  various  retrograding  mo  ioS^rtht 
tw  St  for  aU  sizes  and  descriptions  of  ropes,  may  be  obtained  by  changing  the  diaLet'ers 
of  the  pinions  y,  y,  y,  on  the  under  ends  of  the  drum  spindles  ;  the  carriafes  of  the  inte^ 
vening  wheels  zxx,  being  made  to  slide  round  the  ring  z,  .;V,  w,  is  tKamewo  k  of 
the  machine  and  drawing  motion;  t.t.'t,  are  the  bobbins  containing  the  vaJr  thei 
number  is  varied  to  correspond  with  the  different  sizes  of  the  machine!         ^        ' 

thrl^lT    "^  7^  ^"^y^'i'  »°.«l^.^*'ion  and  plan,  is  calculated  to  make  ropes  from 
three  to  seven  and  one-half  inches  m  circumference,  and  to  an  indefinite  length, 
W  Il'ri5?KT      ^^^*^!^^^'  to  whom  the  art  of  rope-making  is  deeply  indebted,  hav- 
ing observed  that  rope  yarn  is  considerably  weakened  by  passing  through  the  tar-kettle 


564 


ROSIN. 


; 


Ihat  tarred  cordage  loses  ils  strength  progressively  in  cold  climates,  and  so  rapidly  m 
hot  climates  as  to  be  scarcely  fit  for  use  in  three  years,  discovered  that  the  deterioration 
was  due  to  the  reaction  of  the  mucilage  and  acid  of  the  tar.    They  accordingly  proposed 
the  followinsj  means  of  amelioration.     1.  Boiling  it  with  water,  in  order  to  remove  these 
two  soluble  constituents.    2.  Concentrating  the  washed  tar  by  heat,  till  it  becomes  pitcny, 
and  then  restoring  the  plasticity  which  it  thereby  loses,  by  the  addition  of  Ullow,  or  ani- 
mal or  expressed  oils.  ,.    j     r  ^.v;^.*   » 
In    1807,  the  same  able  engineers  obtained  a  patent  for  a  method  of  makAng   a 
belt  or  flat  band,  of  two,  three,  or  more  strands  of  shroud  or  hawser-laid  rope,  placea 
side  by  side,  so  as  to  form  a  band  of  any  desired  breadth,  which  may  be  used  for  hoistmg 
the  kibbles  and  corves  in  mine-shafts,  without  any  risk  of  ils  losing  twist  by  rotation. 
The  ropes  should  be  laid  with  the  twist  of  the  one  strand  directed  to  the  right  hand,  that 
of  the  other  to  the  left,  and  that  of  the  yarns  the  opposite  way  to  the  strands,  whereby 
perfect  flatness  is  secured  to  the  band.     This  parallel  assemblage  of  strands  has  been 
found  also  to  be  stronger  than  when  they  are  all  twisted  into  one  cylinder.     The  patentees 
at  the  same  time  contrived  a  mechanism  for  piercing  the  strands  transversely,  in  order  to 
brace  them  firmly  together  with  twine.     Flat  ropes  are  usually  formed  of  hawsers  wiUi 
three  strands,  softly  laid,  each  containing  33  yarns,  which  with  four  ropes,  compose  a  cord- 
age four  and  a  half  inches  broad,  and  an  inch  and  a  quarter  thick,  being  the  ordinary  dl- 
mensions  of  the  grooves  in  the  whim-pulleys  round  which  they  pass. 

Relative  Strength  of  Cordage,  shroud  laid. 


Size. 

Warm  Register.         1 

Cold  Register. 

Commun  Staple. 

Tons. 

Cwts. 

Qrs.    Lbs. 

Tons. 

Cwts. 

Qrs. 

Us. 

Tons. 

Cwts. 

Qrt. 

Lhs. 

3  inches  bore  - 

H       - 

4  — 
4J         - 

5  — 

H       - 

6  — 

6^          - 

7  — 

n     - 

8  — 

3 
5 

17 
5 

—      16 

3 

4 

5 
9 

3 
2 

16 
21 

2 
3 

9 
6 

1 

1 

24 
27 

6 

8 
10 
12 
14 

17 
13 
14 
19 
15 

2 

1 
2 
2 

16 
8 
4 
4 

24 

5 

7 

9 

11 

13 

17 
5 
3 

1 
3 

3 

1 
2 

4 

1 

4 

25 

8 

4 
5 
6 

7 
8 

5 

1 

9 

12 

17 

3 
2 
2 

1 

6 
8 

22 
20 

18 
21 

2 

10 

15 
17 

9 
18 

1 
3 

9 
8 

9 
11 

16 
4 

3 

1 

14 
21 

24 

27 

2 

8 

1 

16 
26 

20 
23 

11 
8 

1  1 

9 

8 

12 
13 

8 
2 

3 
3 

6 
12 

The  above  statement  is  the  result  of  several  hundred  experiments 

ROPE  Exhihition.-S^Qdmem  of  Smith's  patent  galvanized  and  ungalvanized  iron 
and  copper  wire  ropes  used  for  railway  inclines,  various  mming  operations  including 
pit  guutes,  suspensfon  bridges,  standing  rigging,  lightning  conductors,  window  and 
conservatory  sashes,  fencing,  and  submarine  telegraphs.  xi     „  •  u* 

Iron  wire  ropes  are  of  equal  strength  with  a  hempen  rope  of  four  times  the  weight, 
and  resist  the  wear  and  tear  they  are  subjected  to  in  "running  gear  twice  as  long. 
If  the  surface  of  a  wire  rope  be  left  in  any  part  unprotected  by  some  coating  impene- 
trable to  moisture,  the  internal  fibres  become  in  process  of  time  oxidized,  and  unseen 
decay  goes  forward.  Iron  cleaned  by  acid,  and  plunged  mto  a  bath  containing  melted 
zinc,  bicomes  coated  with  that  metal,  and  the  parts  left  unzmced  alone  rust  Iron  thus 
treated  is  said  to  be  galvanized.  .  ,  - 

Specimens  of  subLrine  telegraph  wire  rope.     Round  wire  '«F  P'-epared  for  use 
The  improvement  is  stated  to  consist  in  preventing  the  wires  and  strands  from  being 
twisted  on  themselves  in  the  process  of  laying  them  round  centre  cores  of  hemp    m 
giving  an  equal  tension  to  eacC  individual  wire,  and  in  preserving  the  mterior  surface 
from  corrosion  by  saturating  the  cores  of  hemp  with  tar,  Ac, 

Sample  of  wire  strand,  used  for  fencing,  signal  cord,  Ac  Sample  of  wire  rope^ 
Wire  rope  for  suspension  bridges,  and  cable  laid  wire  ropes.  Wire  ropes  showing  the 
mode  of  splicing.  Patent  wire  ropes  for  submarine  telegraph;  lightning  conductor ; 
copper  window-sash  cord  and  picture  cord.  Patent  flat  wire  rope,  and  guide  rope  for 
coal  pits,  Ac.    Rope  which  has  been  at  work  constantly  for  five  years. 

ROSIN,  or  COLOPHANY  {Galipot,  Fr.;  Fichtenharz,  Germ.);  is  the  rosm  left 
after  distilling  off  the  volatile  oil  from  the  different  species  of  turpenUne.  Yellow  rosm 
contains  some  water,  which  black  rosin  does  not.    See  Tuopeotinb. 


ROSIN  GAS.  565 

raylof 'I'^Martin^/u  ^^ZX"/"' ^''''K'f'^  '''  ^PP«"^«g««.  "  erected  by  Messrs. 
Aitviur  wiu  jnariineau,  under  the  direction  of  the  patentee,  Profeslor  Daniel  F    R  <? 

Jl7e  to  S"i  Iff  r'"'''^"'™-^  P"J«'=''  °°t  ■»  »  pattern  1;   m°ate  but  a^f„ 
example  to  deter  ;  as  affording  a  very  instructive  lesson  of  the  daneer  of  rushin»  hp»T 

prooaouity  oi  their  ultimate  success.     The  capital,  labour,  and   time  annuallv  wa^tprl 
upon  visionary  schemes  of  this  sort,  got  up  by  chamber  chemists.  l^\n^\Z^{\y^^t 
JTo  more  essential  service  could  be  rendered  to  the  cause  of  p^ductive  industry^h^* 
to  unmask  the  thousand  and  one  chimerical  inventions  whidi  S  I^e  ou^   L  oT 
patents  during  the  ast  thirty  years.     These  remarks  have  been  suggested  bv  the  circum 
stance    hat  50,000;.  were  squandered  upon  the  rosin-gas  concern  fa  fact  cLmunS" 
to  me  by  an  eminent  capitalist,  who  was  induced  b|  fallacious  statement  to  Pmtn.v 
largely  ,n  the  speculation      Had  100/.  been  employed  befrehand  bTa^spasW^ 
Srnfi/'^^^T^"'  in  making  judicious  trials,  and  in  calculating  the  chaLes  of  even^uS 
profit  and  loss,  it  would  have  been  demonstrated,  as  clearly  as  noon-dav  that  rosTm.n^ 
never  compete  with  pitcoal  in  the  production  of  gas-light        Whatever  i^eTu^^vwlf 
expended  m  getting  up  the  following  apparatus,  may  bf  re^^d^^^^J^^^XZ^ 
£r  \S.T'^^^^  *^f.  P."WiC,  and  livert  their  thoughts  from  the  ab^s  tlmt  lay  b£e 
them.     The  mam  preliminary  to  be  settled,  in  all  new  undertakings,  is  the  soundness  of 

SbVJulfDanak"^^^^^^"^^  ^^^  ^""'^  P^^^^^^^   perpetually%klize  the^'pfary 

The  retort  e,  ..  fig.  1221.,  is  seen  charged  with  coke,  which  is  in  the  first  instance  raised 


to  a  bnght  red  heat,  by  means  of  the  furnace  beneath     TKo  «  r 

commerce,  which  is  deposited  in  the  tankTTt^^K  •  V»® .  <^,<>™jnon  brown  rosin  of 
densed  from  the  rosin  v-apours  in  a  nrerHIno:  i  ^^  T^^^  "^'^^  *'^«  e^^euimX  oil  (con- 
pounds  of  the  former  to  t^n  ^  "o,7ofThe  "after^T"-^  fl  *'^'  proportion  of  one  hunilred 
air  beneath  serves  to  preserve  this  in  a  fluid  If  J  i"  k"'"^^  ^^  *^"  ^*"^«  ^"'^  ^^^ated 
aperture  in  the  chimney,  the  temp  ratufe  of  ^1'^^  ^^  *  t^"^'  P^^'"?  ^^'^  ^^^ 
wire-gauze  screen  at  /  Reaches  to  tKoUonf  oMhe  t.nl™^^^^  "^"''^^  regulated.  A 
or  any  impurity  with  which  it  may  iL  m  xed  from  .l,ll-  '  ^?^  P'^'^^"*'  *^^  ^^^'^  ^osin. 

ITie  meTted  rosin  Imvincr  pa^ed  bv  t  f.  „/        f  ?H"^  ^^^  stopcock, 
retort,  falls  on  the  coke'  ind  i^t^  pas^I Je  th^Klt^'  'Tf  ^'  "".^  ^^P^^"  ^'  '"*«  '^^ 
On  arriving  at  the  other  end  of  the  retort    a  wJ     ^^^"^  "J^"'  ^"^"^^  decomposed, 
the  form  of  condensable  vapour    s  separated  ^!ff    P?"^'"*"  °^  ^^'^  ^'^  «^  turpentiW^  in 
water  from  a  cistern  aboveS  the  nKilnLhl!  refrigerator  5. ;  this  is  sup^ied  with 

and  <i.>«  beneath  the  surface  of  the  flu?d  in  h:"^^^^^^  TTif  "^^^  *"'^  *' 

and  the  gas  proceeds  in  a  perfectly  pure  state  hvf  hi  ^.^'!.««"Pjete8  the  condensation ; 
to  the  floating  reservoir,  for  use  '  ^  ^^^  P'P®  ^'  *^  ^^^  gasometer,  or  rather 


iti     i 


566 


RUM. 


SABOTIERE. 


507 


ftf! 


Hi 


borne  in  mind  that  the  tube  prevents  the  escape  of  the  gas,  which  would  otherwise  pass 
awav  from  the  bo»with  the  essential  oil.     Another  pipe  and  sjphon  w,  n,  serve  to  con- 
vev  the  condensed  essential  oil  from  the  top  cistern. 
BOTTEN-STONK     See  Tripoli. 

ROUGE.  (Fard,  Fr.)  The  only  cosmetic  which  can  be  applied  without  injury  to 
brighten  a  lady's  complexion,  is  that  prepared,  by  the  following  process,  from  safflower, 
{Carthamus  tinctoritu.)  The  flowers,  after  being  washed  with  pure  water  till  it  comes 
off  colorless,  are  dried,  pulverized,  and  digested  with  a  weak  solution  of  crystals  of  soda, 
which  assumes  thereby  a  yellow  color.  Into  this  liquor  a  quantity  of  finely  carded 
white  cotton  wool  is  plunged,  and  then  so  much  lemon  juice  or  pure  vinegar  is  added  as 
to  supersaturate  the  soda.  The  coloring  matter  is  disengaged,  and  falls  down  in  an  im- 
palpable powder  upon  the  cotton  filaments.  The  cotton,  after  being  washed  in  cold  water, 
to  remove  some  yellow  coloring  particles,  is  to  be  treated  with  a  fresh  solution  of  carbo- 
nate of  soda,  which  takes  up  the  red  coloring  matter  in  a  state  of  purity.  Before  precipitating 
this  pigment  a  second  time  by  the  acid  of  lemons,  some  soft  powdered  talc  should  be  laid 
in  the  bottom  of  the  vessel,  for  the  purpose  of  absorbing  the  fine  rouge,  in  proportion  as 
it  is  separated  from  the  carbonate  of  soda,  which  now  holds  it  dissolved.  The  colored 
mixture  must  be  finally  triturated  with  a  few  drops  of  olive  oil,  in  order  to  make  it  smooth  and 
marrowy.  Upon  the  fineness  of  the  talc,  and  the  proportion  of  the  safflower  precipitate 
which  it  contains,  depend  the  beauty  and  value  of  the  cosmetic.  The  rouge  of  the  above 
second  precipitation  is  received  sometimes  upon  bits  of  fine-twisttd  woollen  stuff,  called 
crepons,  which  ladies  rub  upon  their  cheeks. 
RUBY.    See  Lapidary. 

RUM,  is  a  variety  of  ardent  spirits,  distilled  in  the  West  Indies,  from  the  fermented 
skimmings  of  the  sugar  teaches,  mixed  with  molasses,  and  diluted  with  water  to  the 
proper  degree.  A  sugar  plantation  in  Jamaica  or  Antigua,  which  makes  200  hogs- 
heads of  sugar  of  about  16  cwts.  each,  requires,  for  the  manufacture  of  its  rum,  two  cop- 
per stills ;  one  of  1000  gallons  for  the  wash,  and  one  of  600  gallons  for  the  low  wines,  with 
corresponding  worm  refrigeratories.  It  also  requires  two  cisterns,  one  of  3000  gallons  for 
the  lees  or  spent  wash  of  former  distillations,  called  dunder  (Quasi  redundar,  Span.), 
another  for  the  skimmings  of  the  clarifiers  and  teaches  of  the  sugarhouse ;  along  with 
twelve,  or  more,  fermenting  cisterns  or  tuns. 

Lees  that  have  been  used  more  than  three  or  four  times,  are  not  considered  to  be 
equally  fit  for  exciting  fermentation,  when  mixed  with  the  sweets,  as  fresher  lees.  The 
wort  is  made,  in  Jamaica,  by  adding  to  1000  gallons  of  dunder,  120  gallons  of  molasses, 
720  gallons  of  skimmings  (  =  120  of  molasses  in  sweetness),  and  160  gallons  of  water; 
so  that  there  may  be  in  the  liquid  nearly  12  per  cent,  of  solid  saccharum.  Another 
proportion,  often  used,  is  100  gallons  of  molasses,  200  gallons  of  lees,  300  gallons  of 
skimmings,  and  400  of  water ;  the  mixture  containing,  therefore,  15  per  cent,  of  sweets. 
These  two  formulae  prescribe  so  much  spent  wash,  according  to  my  opinion,  as  would  be 
apt  to  communicate  an  unpleasant  flavor  to  the  spirits.  Both  the  fermenting  and  flavor- 
ing principles  reside  chiefly  in  the  fresh  cane  juice,  and  in  the  skimmings  of  the  clarifier ; 
because,  after  the  sirup  has  been  boiled,  they  are  in  a  great  measure  dissipated.  I  have 
made  many  experiments  upon  fermentation  and  distillation  from  West  India  molasses,  and 
always  found  the  spirits  to  be  perfectly  exempt  from  any  rum  flavor. 

The  fermentation  goes  on  most  uniformly  and  kindly  m  very  large  masses,  and  requires 
from  9  to  15  days  to  complete ;  the  difference  of  time  depending  upon  the  strength  of  the 
wort,  the  condition  of  its  fermentable  stuff,  and  the  state  of  the  weather.  The  progress 
of  the  attenuation  of  the  wash  should  be  examined  from  day  to  day  with  a  hydrometer,  ns 
1  have  described  in  the  article  Distillation.  When  it  has  reached  nearly  to  its  maxU 
mum,  the  wash  should  be  as  soon  as  possible  transferred  by  pumps  into  the  still,  and 
worked  off  by  a  properly  regulated  heat ;  for  if  allowed  to  stand  over,  it  will  deteriorate 
y  acetification.  Dr.  Higgins's  plan,  of  suspending  a  basket  full  of  limestone  in  the  wash 
tuns,  to  counteract  the  acidity,  has  not,  I  believe,  been  found  to  be  of  much  use.  It 
would  be  better  to  cover  up  the  wash  from  the  contact  of  atmospheric  air,  and  to  add 
perhaps  a  very  little  sulphite  of  lime  to  it,  both  of  which  means  would  tend  to  arrest  the 
acetous  fermentation.  But  one  of  the  best  precautions  against  the  wash  becoming  sour, 
is  to  preserve  the  utmost  cleanliness  among  all  the  vessels  in  the  distillery.  They  should 
be  scalded  at  the  end  of  every  round  with  boiling  water  and  quicklime. 

About  115  gallons  of  proof  rum  are  usually  obtained  from  1200  gallons  of  wash.  The 
proportion  which  the  product  of  rum  bears  to  that  of  sugar,  in  very  rich  moist  plantations, 
is  rated,  by  Edwards,  at  82  gallons  of  the  former  to  16  cwt.  of  the  latter ;  but  the  more 
usual  ratio  is  200  gallons  of  rum  to  3  hogsheads  of  sugar.  But  this  proportion  will  ne- 
cessarily vary  with  the  value  of  rum  and  molasses  in  the  market,  since  whichever  fetches 
the  most  remunerating  price,  will  be  brought  forward  in  the  greatest  quantity.  In  one 
considerable  estate  in  the  island  of  Grenada,  92  gallons  of  rum  were  made  for  eTery 
hogshead  (16  cwts.)  of  sugar.    See  Still. 


Imported.  Retained  for  Oonsamption.  Duty  received. 
Gallons.                       Gallons.  £. 

1860  4.194,683  2,902,212  1,100,286 

1851  4,747,031  2,880,776  1,098,200 

RUSSIAN  LEATHER,  as  tanned  at  Kazan.  The  hides  to  be  tanned  may  be  either 
fresh  from  the  animal  or  dry,  no  matter  which ;  they  are  first  laid  to  soak  for  3  days  and 
nights  in  a  solution  of  potash,  to  which  some  quicklime  is  added.  The  potash  used  Is 
made  of  the  tree  called  in  Russ  ilim  (the  common  elm),  which  sort  is  said  to  be  preferable 
to  any  other,  if  not  essential ;  it  is  not  purified,  so  that  it  is  of  a  brown  colour  and  of  an 
earthy  appearance :  about  12  poods  of  this,  (the  pood  is  86  lbs.  English),  and  2  poods  of 
lime  serve  for  100  skins.  As  they  have  no  way  of  ascertaining  the  degree  of  causticity 
of  the  alkali  but  by  its  effect  upon  the  tongue,  when  they  find  it  weak  they  let  the  skins 
lie  loDgCT  in  the  solution. 

When  the  skins  are  taken  out  of  this  solution  they  are  carried  to  the  river  and  left 
under  water  for  a  day  and  a  night 

Next  a  vedro  of  dog's  dung  is  boiled  in  as  much  water  as  is  enough  to  soak  60  skins 
(the  vedro  is  equal  to  2696  English  imperial  gallons),  but  in  the  winter  time,  when  the 
dung  is  frozen,  twice  that  quantity  is  found  necessary.  The  skins  are  put  into  this  solu- 
tion, not  while  it  is  boiling  hot,  but  when  at  the  heat  which  the  hand  can  bear  ;  in  this 
they  lie  one  day  and  one  night. 

The  skins  are  then  sewed  up  so  as  to  leave  no  hole ;  in  short,  so  as  to  be  water-tight ; 
about  one  third  of  what  the  skin  will  contain  is  then  filled  up  with  the  leaves  and  small 
twigs  chopped  together  of  the  plant  called  in  Russ  Toloknanka (Arbutus  uvaursi,  some- 
times called  bear  berry),  which  is  brought  from  the  environs  of  Solikamskaga,  and  the 
skin  is  then  filled  up  with  water. 

The  skins  thus  filled  are  laid  one  on  the  other  in  a  large  trough,  and  heavy  stones  upon 
them,  so  as  by  their  weight  to  press  the  infusion  through  the  pores  of  the  skin  in  about 
4  hours ;  yet,  as  it  was  said  at  the  same  time,  that  the  skins  are  filled  up  with  the  same 
water  which  had  been  pressed  out  10  times  successively,  and  that  the  whole  operation 
takes  but  one  day  and  one  night,  this  leaves  but  2^  hours  for  each  time. 

The  skins  are  then  taken  to  the  river  and  washed,  and  are  ready  for  the  dyeing.  The 
whitest  skins  are  laid  aside  for  the  red  and  yellow  leather. 

(The  operations  in  dyeing  follow,  but  are  here  omitted.) 

To  soften  the  skins  after  dyeing,  they  are  harassed  by  a  knife,  the  point  of  which  is 
curved  upwards. 

RUST,  is  the  orange-yellow  coat  of  jieroxide  which  forms  upon  the  surface  of  iron 
exposed  to  moist  air.  Oil-paint,  varnish,  plumbago,  or  a  film  of  caoutchouc,  may  be 
employed,  according  to  circumstances,  to  prevent  the  rusting  of  iron  utensils. 

RYE,  consists,  according  to  the  analysis  of  Einhof,  of  242  of  husk,  65-6  of  flour,  and 
10-2  of  water,  in  100  parts.  This  chemist  found  in  100  parts  of  the  flour,  61-07  of  starch, 
9-48  of  gluten,  828  of  vegetable  albumen,  3'28  of  uncrystallizable  sugar,  1109  of  gum, 
638  of  vegetable  fibre,  and  the  loss  was  562,  including  a  vegetable  acid  not  yet  investi- 
gated.   Some  phosphate  of  lime  and  magnesia  are  also  present     See  Gin.  , 


s. 

SABOTIE^RR  The  apparatus  for  making  ices,  called  "  sabotiSre,"  is  composed  of 
two  principal  parts— a  pail  which  is  indented  towards  the  top  and  covered ;  and  the 
saboti^re,  or  inner  vessel,  slightly  conical,  which  is  inserted  in  a  pail,  on  which  it  rests  by 
a  projecting  border  or  rim ;  this  vessel  is  closed  at  the  bottom  like  a  cup,  and  open  at  the 
top  to  admit  the  creams  to  be  iced.  It  is  closed  at  the  top  by  a  cover  furnished  with  a 
handle  and  a  hook,  which  fastens  it  to  the  rim  of  the  vessel.  This  apparatus  works  as 
follows :— The  freezing  mixture,  composed  of  sulphate  of  soda  pulverized  and  hydro- 
chloric acid,  IS  turned  into  the  pail,  and  the  creams  to  be  iced  into  the  inner  vessel ;  iU 
cover  is  then  fastened  by  the  hook,  and  the  vessel  is  set  into  the  pail  among  the  freezing 
liquid ;  then  taking  the  whole  by  the  handle  of  the  saboti^re,  an  alternate  motion  of 
rotation  is  given  to  it  for  about  a  quarter  of  an  hour,  when  the  cream  is  sufficientlv  frozen. 
The  cover  is  opened  from  time  to  time,  and  the  mixture  well  stirred  with  a  spoon  adapted 
for  the  purpose.  The  freezing  mixture  must  be  removed  every  15  or  20  minutes.  There 
is  a  measure  for  the  freezing  mixture,  which  contains  2  parts  of  salt  and  1  of  acid.  Tlie 
pail  is  furnished  with  a  handle,  and  is  surrounded  with  thick  woollen  cloth  to  exclude  the 
effect  of  outward  air. 


tf68 


SADDLER'S  IRONMONGERY. 


SACCHAROMETER. 


569 


4i 

1                 t    ' 

SACCHAROMETER  is  the  name  of  a  hydrometer,  adapted  by  its  scale  to  poin« 
<mt  the  proportion  of  sugar,  or  the  saccharine  matter  of  malt,  contained  in  a  solution  of 
any  specific  gravity.  Brewers,  distillers,  and  the  Excise,  sometimes  denote  by  the  term 
gravity,  the  excess  of  weight  of  1,000  parts  of  a  liquid  by  volume  above  the  weight  of  a 
like  volume  of  distilled  water ;  so  that  if  the  specific  gravity  be  1,045, 1,070, 1,090,  &c., 
the  gravity  is  said  to  be  45,  70,  or  90 ;  at  others,  they  thereby  denote  the  weight  of 
saccharine  matter  in  a  barrel  (36  gallons)  of  worts ;  and  again,  they  denote  the  excess 
in  weight  of  a  barrel  of  worts  over  a  barrel  of  water,  equal  to  36  gallons,  or  360  pounds. 
This  and  the  first  statement  are  identical,  only  1,000  is  the  standard  in  the  first  case, 
and  360  in  the  second. 

The  saccharometer  now  used  by  the  Excise,  and  by  the  trade,  is  that  constructed  by 
Mr.  R.  B.  Bate,  well  known  for  the  accuracy  of  his  philosophical  and  mathematicai 
instruments.  The  tables  published  by  him  for  ascertaining  the  values  of  wort  or  wash, 
and  low  wines,  are  preceded  by  explicit  directions  for  their  use.  "  The  instrument  is 
composed  of  brass ;  the  ball  or  float  being  a  circular  spindle,  in  the  oppos'te  ends  of 
which  are  fixed  a  stem  and  a  loop.  The  stem  bears  a  scale  of  divisions  numbered 
downward  from  the  first  to  30 ;  these  divisions,  which  are  laid  down  in  an  original 
manner,  observe  a  diminishing  progression  according  to  true  principles ;  therefore  each 
division  correctly  indicates  the  one  thousandth  part  of  the  specific  gravity  of  water  j 
and  further,  by  the  alteration  made  in  the  bulk  of  the  saccharometer  at  every  change 
of  poise,  each  of  the  same  divisions  continues  to  indicate  correctly  the  said  one  thou- 
sandth part  throughout." 

In  my  own  practice,  I  prefer  to  take  specific  gravities  of  all  liqukls  whatever  with  a 
glass  globe  containing  500  or  1,000  grains  of  distilled  water  at  60^  Fahr.,  when  it  is 
closed  with  a  capillary-bored  glass  stopper ;  and  with  the  gravity  so  taken,  I  look  into 
a  table  constructed  to  show  the  quantity  per  cent,  of  sugar,  malt,  extract,  or  of  any 
other  solid,  proportional  to  the  density  of  the  solution.  By  bringing  the  liquid  in  the 
gravity-bottle  to  the  standard  temperature,  no  correction  on  this"  account  is  needed. 
Mr.  Bate's  elaborate  table  contains  all  these  equations  correctly  for  solutions  of  sugar 
of  every  successive  specific  gravity.  When  employed  in  such  researches  by  the  Mo- 
lasses Committee  of  the  House  of  Commons  in  the  year  1830,  I  found  that  the  specific 
gravities  of  solutions  of  the  concrete  extract  of  malt  differed  somewhat  from  tliose  of 
«olutions  of  sugar,  as  given  by  Mr.  Bate.     (See  page  100  of  Dictionary.^ 

The  following  table  shows  the  quantities  of  sugar  contained  in  syrups  of  the  annexed 
specific  gravities.     It  was  the  result  of  experiments  carefully  made : — 


Table  exhibiting  the  Quantity  of  Sugar,  in  Pounds  Avoirdupois,  which  is  contained  in 
One  Gallon  of  Syrup,  at  successive  Degrees  of  Density,  at  60°  F. 


lExperimenlal  spec,  gravity. 

Suj^r  in  100-  by 

Experimental  spec,  gravity. 

Sugar  in  100-  by 

,        of  solution  at  60°  F. 

weight. 

of  solution,  at  60°  F. 

weight. 

'               1-3260 

66-666 

1-1045 

25-000 

1-2310 

50-000 

1-0905 

21-740 

1-1777 

40-000 

1-0820 

20-000 

1-4400 

33-333 

1-0635 

16'66Q 

1-1340 

31-250 

1-0500 

12-500 

1-1250 

29-412 

1-0395 

10-000 

1-1110 

26-316 

N.  B.  The  column  in  the  opposite  table,  marked  Solid  extract  by  weight,  is  Mr. 
Bate's ;  it  may  be  compared  with  this  short  table,  and  also  with  the  table  of  malt  in- 
fusions in  page  100  of  the  Dictionary. 

If  the  decimal  part  of  the  number  denoting  the  specific  gravity  of  syrup  be  mul- 
tiplied by  26,  the  product  will  denote  very  nearly  the  quantity  of  sugar  per  gallon  in 
pounds  at  the  given  specific  gravity.* 

SADDLER'S  IRONMONGERY.  Zowe,  John  and  Henry,  Clarence  Works, 
Birmingham, — Manufacturers.  The  manufacture  of  saddlers'  ironmongery  is  principally 
located  at  Birmingham  and  in  the  neighbouring  towns  of  Wolverhampton,  Walsall,  <fec. 
Its  object  is  the  production  of  bits,  spurs,  stirrups,  curb-chains,  <fec.  These  are  formed 
out  of  iron  and  steel  by  the  ordinary  process  of  hammering ;  and  are  finished  by  japanning, 
tinning,  burnishing,  or  plating  with  brass  or  silver.  Some  produced  for  the  South 
American  market  ar6  of  very  fantastic  shapes,  and  richly  gilt;  they  differ  from  those 

♦  This  rule  was  annexed  to  an  extensive  table,  representing  the  qnantitiee  of  sugar  per  gallon,  cor- 
T«^ondIng  to  the  specific  gravities  of  the  syrups,  constracted  by  the  Author,  for  the  Excise,  la  subser- 
Tieacy  to  the  Beet-root  bill. 


1000 

1001 

I  002 

1003 

1-004 

J  005 

1-006 

1007 

1-008 

1009 

1010 

1-011 

1012 

1-013 

1014 

1015 

1016 

1017 

1-016 

1-019 

/•020 

1-021 

1022 

1-023 

1024 

1-025 

]  026 

1  027 

1028 

1  029 

1030 

1  031 

1032 

1033 

1034 

1  035 

1  036 

1037 

1038 

1039 

1  040 

1041 

1042 

1043 

1-044 

1-045 

1046 

1  047 

1-048 

1049 

1  050 

1-051 

1  052 

1053 

1-054 

1055 

1  056 

1057 

1058 

1059 

1-060 

1061 

1062 

1063 

1064 

1065 

1066 

1067 

1-068 

1069 

1-070 

1-071 

1072 

1073 

1  074 

1075 

1-076 


5o 


00000 

0  0255 

00510 

00765 

0  1020 

01 275 

0  1530 

01785 

0-2040 

0-2295 

02550 

0-2805 

0  3060 

0-3315 

0-3570 

0-3625 

04180 

04335 

0-4590 

04845 

0-5100 

05351 

0  5602 

0-5853 

06104 

06355 

0-6606 

0-6857 

07108 

0  7.159 

07610 

0-7861 

0  8112 

08363 

0-8614 

08866 

09149 

0  9-149 
0-9768 
10090 
10400 

1  0653 
10906 
1  1159 
1  1412 
1  1665 
1-1918 
1  2171 
12424 
1  2687 
1-2940 
1  3206 
1  3472 
1-3738 
14004 
1-4270 
1-4536 
1-4802 
1-5068 
1  5334 
1-5600 
1-5870 
1-6142 
1-6414 
1-6688 
16959 
17228 
1-7496 
17764 
1-8033 
1-8300 
18571 
18843 
1  9116 
1-9385 
1-9653 
1-9928 


K 


(U 


^a 


•0000 
•0026 
•0051 
•0077 
•0102 
•0128 
0153 
•0179 
•0204 
•0230 
•0255 
•0280 
•0306 
•0331 
•0.156 
•0361 
•0406 
•0431 
■0456 
•0481 
•0506 
•0531 
•0555 
•0580 
•0605 
•0629 
•0654 
•0678 
•0703 
-0727 
•0752 
•0776 
•0800 
•0825 
•0849 
•0873 
•0897 
-0921 
•09^5 
•0969 
•0993 
•1017 
•1041 
•1065 
•1089 
•1113 
■1136 
•1160 
•1184 
-1207 
•1231 
•1254 
•1278 
•1301 
•1325 
•1348 
■1372 
•1395 
-1418 
•1441 
1464 
-1487 
•1510 
•1533 
•1556 
-1579 
•1602 
-1625 
-1647 
-1670 
-1693 
■1716 
-1738 
-1761 
-1783 
-1806 
-1828 


1077 
1-078 
1-079 
1-080 
1-081 
1082 
1083 
1-084 
1085 
1086 
1087 
1-088 
1-089 
1-090 
1091 
1-092 
1-093 
1094 
1095 
1096 
1097 
1-098 
1099 
1-100 
1-101 
1  102 
1-103 
1-104 
1  105 
1-106 
1-107 
1-108 
1-109 
1-110 
I-lll 
]112 
1113 
1114 
1115 
1-116 
1  117 
1-118 
1119 
1-120 
1-121 
1-122 
I  123 
1.124 
1-125 
1126 
11-27 
1-128 
M29 
1130 
1  131 
1  132 
133 
M34 
1135 
1  136 
1137 
1  138 
1  139 
1  140 
1-141 
1-142 
1-143 
1  144 
1  145 
1146 
1  147 
1148 
1-149 
1150 
1  151 
1  152 
1  153 


I 


2  0197 
20465 
20734 
2- 1006 
2-1275 
2-1543 
21811 
2-2080 
2-2359 
2-2627 
22894 
23161 
23438 
2-3710 
23987 
2-4256 
2-4524 
2-4792 
25061 
2-5329 
2  5598 
25866 
2-6130 
26404 
2-6663 
2-6921 

2  7188 
27446 
2-7704 
2-7961 
28227 
28485 
28740 
2-9001 
2-9263 
29522 
29780 
3-0045 
3-0304 

3  0563 
30821 
3  1080 
3  1343 
31610 
3-J871 
3-2130 
3  2399 
3-2658 
3-2916 
3-3174 
3-3431 
33690 
3-3949 
3  4211 
3-4490 
3-4769 
3-5048 
35326 
3-5605 
3-5882 
3-6160 
3-6437 
3-6716 
3-7000 
3-7281 
3-7562 
37840 
38119 
3  8398 
3-8677 

3  8955 
39235 
39516 
3-9801 

4  0070 
4034S 
40611 


•1851 
•1873 
•1896 
•1916 
•1941 
•1963 
•1985 
8007 
2029 
•2051 
•2073 
•2095 
•2117 
•2139 
•2161 
•2183 
•2205 
•2227 
•2249 
•2270 
•2292 
•2314 
•2335 
•2357 
•2378 
•2400 
•2421 
-2443 
•2464 
•2486 
•2507 
•2529 
•2550 
•2571 
•2593 
•2614 
•2635 
•2656 
•2677 
•2698 
•2719 
•2740 
■2761 
•2782 
■2803 
•2824 
•2845 
•2865 
•2886 
•2907 
•2927 
•2946 
•2969 
•2989 
•3010 
•3030 
•3051 
•3071 
•3092 
•3112 
•3132 
•3153 
•3173 
•3193 
•3214 
-3234 
•3254 
-3274 
-3294 
•3314 
-3334 
-3354 
-3374 
-3394 


1-154 

1155 

1-156 

1  157 

1  158 

1159 

1-160 

1-161 

1162 

1163 

1164 

1165 

1166 

1-167 

1168 

1169 

1170 

1-171 

1172 

1-173 

1174 

1175 

1176 

1177 

1178 

1179 

II80 

1181 

1182 

1183 

n84 

1185 

1186 

ri67 

1188 

1189 

1190 

1191 

1192 

1193 

1194 

1195 

1196 

1197 

1198 

1199 

1200 

1-201 

1202 

1203 

1204 

1205 

1206 

1207 

1208 

1-209 

1  210 

1211 

1  212 

1213 

1  214 

1-215 

1-216 

1-217 

1218 

1219 

1-220 

1221 

1-2-22 

1-223 

1-224 

1  225 

1  226 

1-227 

1  228 

1  229 

1-230 


Co 

.2* 


4-0880 

4  1148 

41319 

4-1588 

41 857 

4-2128 

4-2502 

4-2771 

4-3040 

4-3309 

43578 

4-3847 

4-4115 

44383 

4-4652 

4-4923 

4-5201 

4-5460 

4-5722 

4-5983 

4  6242 

4-6505 

4-6764 

4-7023 

4^7281 

4-75.19 

4  7802 

4-8051 

4-8303 

4-6554 

4-6602 

4-9051 

4-9300 

4  9552 
4-9803 

5  0054 
50301 
50563 
5-0822 
5- 1060 
51341 
51602 
5-1863 
5-2124 
5-2381 
5-2639 
5-2901 
5-3160 
53422 
5-3681 
53941 
5-4203 
54462 
5-4720 
5-4979 
55239 
55506 
5-5786 
5  6071 
5-6360 
5-6651 
5-6942 
57233 
57522 
5-7814 
58108 
5-8401 
5-86S0 
5-6962 
59242 
5-9523 
5-9801 
60081 
6-0361 
60642 
60925 
6-1S05 


1231 

1  232 

1-233 

1-234 

1  235 

1236 

1-237 

1  238 

1  239 

1-240 

1241 

1-242 

1243 

1  244 

1245 

1-246 

1-247 

1248 

1-249 

1  250 

1  251 

1-252 

1  253 

1254 

1  255 

1256 

1-257 

1  258 

1-259 

1-260 

1-261 

1-262 

1-263 

1264 

1-265 

1-266 


1-267 
1  268 
1  269 


1  270 
1271 
1  272 
1-273 
1274 
1-275 
1-276 
1277 
1-278 
1279 
1-280 
1  281 
1-282 
1-283 
1284 
1-285 
1-286 
1  287 
1-288 
1289 
1-290 
1  291 
1  292 
1  293 
1294 
1295 
1296 
1297 
1298 
1299 
1-300 


.2 


6-1474 

61743 

62012 

6-2260 

6-2551 

6  2622 

6  3093 

6-3362 

63631 

6-3903 

6-4152 

6-4401 

6-4650 

6  4902 

65153 

6-5402 

6-5651 

65903 

66152 

6  6402 

6-6681 

66960 

6-7240 

6-7521 

6-7800 

6-6061 

6  8362 

6864.1 

6-8y2l 

6  9201 

6-9510 

6  9622 
70133 

7  0444 
7-0751 
71060 
7-1369 
71678 
71988 
7-2300 
7-2601 
7-2902 
73204 
7-3506 
73807 
7-4109 
7-4409 
7-4708 
7-5007 
7-5307 
7-5600 
7  5891 
76180 
7  •6469 
7-6758 
7-7048 
7  7331 
7-7620 
77910 
7-8201 
''848J 
7-8763 
7-9048 
79321 
79600 
7-9879 
8-0158 
8-0448 
80719 
81001 


mmtii 


570 


SAL  AMMONIAC. 


SAL  AMMONUC. 


571 


for  home  use  in  their  massive  appearance,  the  sides  of  the  bits  being  carved  into  various 
designs,  and  the  rowels  of  the  spurs  are  made  enormously  large.  When  bits  arc  to  be 
plated  with  metal  thev  are  tinned,  and  a  piece  of  metal  of  sufficient  thickness  is  wrapt 
or  bent  round  it  by  pressure ;  this  is  aided  by  pressing  down  upon  them  with  burnishers, 
Ac  When  the  covering  has  been  made  to  adhere  very  closely,  the  whole  is  heated,  tin 
solder  is  applied,  and  the  two  become  united :  the  final  polish  is  given  by  the  friction  of 
buflf  leather  and  powdered  burnt  rotten-stone. 

SAFFLOWER.   This  dye-stuff  has  been  fully  described  under  Caethamus  and  Rouge. 

Landings,  Deliveries,  and  Stocks  of  Safflower, 


Landed. 

Delivered. 

Stock  1st  Janaary. 

Bales. 

Bales. 

Bales. 

In  December    1851 

913 

331 

— 

1850 

1,176 

465 

— 

In  12  months  1851 

4,431 

4,701 

2,990 

1850 

5,065 

3,266 

8,260 

1849 

3,756 

8,529 

1,461 

1848 

2,667 

2,269 

1,254 

Prices,  January,  1852,  fine,  6/.  5«.  to  11.  10«.  per  cwt. ;  middling,  4/.  5«.  to  6/.  10». ; 

ordinary,  21.  to  Si.  lOs.  ^  ,  ^     r     i. 

SAFFRON  (Saffran,  Fr.  and  Genn.)  is  a  filamentous  cake,  composed  of  the 
stigmata  of  the  flowers  of  the  Crocus  sativus.  It  contains  a  yellow  matter  called  poly- 
chroite,  because  a  small  quantity  of  it  is  capable  of  coloring  a  great  body  of  water.  This 
is  obtained  by  evaporalin?  the  watery  infusion  of  saflron  to  the  consistence  of  an  extract, 
digesting  the  extract  with  alcohol,  and  concentrating  the  .ilcoholic  solution.  The 
polychroite  remains  in  the  form  of  a  brilliant  mass,  of  a  reddish-yellow  color,  transpa- 
rent, and  of  the  consistence  of  honey.  It  has  the  agreeable  smell,  with  the  bitter  pungent 
taste,  of  saliron.  It  is  very  soluble  in  water ;  and  if  it  be  stove-dried,  it  deliquesces 
speedily  in  the  air.  According  to  M.  Henry  pere,  polychroite  consists  of  eighty  parts  of 
coloring  matter,  combined  with  20  parts  of  a  volatile  oil,  which  cannot  be  separated 
by  distillation  till  the  coloring  matter  has  been  combined  with  an  alkali.  By  mixing 
one  part  of  shred  saffron  with  eight  parts  of  saturated  brine,  and  one  half  part  of 
caustic  ley,  and  distilling  the  mixture,  the  oil  comes  over  into  the  receiver,  and  leaves 
the  coloring  matter  in  the  retort,  which  may  be  precipitated  from  the  alkaline 
solution  by  an  acid.  The  pure  coloring  matter,  when  dried,  is  of  a  scarlet  hue,  and 
then  readily  dissolves  in  alcohol,  as  also  in  the  fat  and  volatile  oils,  but  sparingly  in 
water.  Lisht  blanches  the  reddish-ytllow  of  saffron,  even  when  it  is  contained  in  a  full 
vial  well  corked.  Polychroite,  when  combined  with  fat  oil,  and  subjected  to  dry  distil- 
lation, affords  ammonia,  which  shows  that  azote  is  one  of  its  constituents.  Sulphuric  acid 
colors  the  solution  of  polvchroite  indigo  blue,  with  a  lilach  cast ;  nitric  acid  turns  it  green, 
of  various  shades,  according  to  the  stale  of  dilution.  Protochloride  (muriate)  of  tin  pro- 
duces a  reddish  precipitate. 

Saffron  is  employed  as  a  seasoning  in  French  cookery.  It  is  also  used  to  tinge  confec- 
tionary articles,  liqueurs,  and  varnishes ;  but  rarely  as  a  pigment. 

SAGO  CSagou^  Fr.  and  Germ.)  is  a  species  of  starch,  extracted  from  the  pith  of  the 
sago  palm,  a  tree  which  grows  to  the  height  of  30  feet  in  the  Moluccas  and  the  Philippines. 
The  tree  is  cut  down,  cleft  lengthwise,  and  deprived  of  its  pith,  which  being  washed  with 
water  upon  a  sieve,  the  starchy  matter  comes  out,  and  soon  forms  a  deposite.  This  is 
dried  to  the  consistence  of  dough,  pressed  through  a  metal  sieve  to  corn  it  (which  is  called 
pcarHixg),  and  then  dried  over  a  fire  with  agitation  in  a  shallow  copper  pan.  Sago  is 
sometimes  imported  in  the  pulverulent  state,  in  which  it  can  be  distinguished  from  arrow- 
root only  by  microscopic  examination  of  its  particles.  These  are  uniform  and  spherical, 
not  unequal  and  ovoid,  like  those  of  arrow-root. 

SAL  AMMONIAC.  The  manufacture  of  this  salt  may  be  traced  to  the  remotest 
era.  Its  name  is  derived  from  Ammonia,  or  the  temple  of  Jupiter  Ammon,  in  Egypt, 
near  to  which  the  salt  was  originally  made.  Sal  ammoniac  exists  ready  formed  in  seve- 
ral animal  products.  The  dung  and  urine  of  camels  contain  a  sufficient  quantity  to 
have  rendered  its  extraction  from  them  a  profitable  Egyptian  art  in  former  times,  in  order 
to  supply  Europe  with  the  article.  In  that  part  of  Africa,  fuel  being  very  scarce,  recourse 
is  had  to  the  dung  of  these  animals,  which  is  dried  for  that  purpose,  by  plastering  it  upon 
the  walls.  When  this  is  afterwards  burned  in  a  peculiar  kind  of  furnace,  it  exhales  a  thick 
UDoke  replete  with  sal  ammoniac  in  vapor :  the  soot  of  course  contains  a  portion  of  that 


salt,  condensed  along  with  other  products  of  combustion.  In  every  part  of  Egypt,  bat  es. 
pecially  in  the  Delta,  peasants  are  seen  driving  asses  loaded  with  bags  of  that  soot,  on 
tlieir  way  to  the  sal  ammoniac  works. 

Here  it  is  extracted  in  the  following  manner.  Glass  globes  coated  with  loam  arc 
filled  with  the  soot  pressed  down  by  wooden  rammers,  a  space  of  only  two  or  three  inches 
Yemg  lefl  vacant,  near  their  mouths.  These  globes  are  set  in  round  orifices  formed  in 
the  ridge  of  a  long  vault,  or  large  horizontal  furnace  flue.  Heat  is  gradually  applied  by 
a  fire  of  dry  camels'  dung,  and  it  is  eventually  increased  till  the  globes  become  obscurely 
red.  As  the  muriate  of  ammonia  is  volatile  at  a  temperature  much  below  ignition,  ii 
rises  out  of  the  soot  in  vapor,  and  gets  condensed  into  a  cake  upon  the  inner  surface  of 
the  top  of  the  globe.  A  considerable  portion,  however,  escapes  into  the  air ;  and  another 
portion  concretes  in  the  mouth,  which  must  be  cleared  from  time  to  time  by  an  iron  rod. 
Towards  the  end,  the  obstruction  becomes  very  troublesome,  and  must  be  most  carefully 
attended  to  and  obviated,  otherwise  the  globes  would  explode  by  the  uncondensed 
vapors.  In  all  cases,  when  the  subliming  process  approaches  to  a  conclusion,  the 
globes  crack  or  split ;  and  when  they  come  to  be  removed,  after  the  heat  has  subsided, 
Ihey  usually  fall  to  pieces.  The  upper  portion  of  the  mass  is  separated,  because  to  it  the 
white  salt  adheres ;  and  on  detaching  the  pieces  of  glass  with  a  hatchet,  it  is  ready  for  the 
market.  At  the  bottom  of  each  balloon  a  nucleus  of  salt  remains,  surrounded  with  fixed 
pulverulent  matter.  This  is  reserved,  and  after  being  bruised,  is  put  in  along  with  the 
charge  of  soot  in  a  fresh  operation. 

The  sal  ammoniac  obtained  by  this  process  is  dull,  spongy,  and  of  a  grayish  hue ; 
but  nothing  belter  was  for  a  long  period  known  in  commerce.  Forty  years  ago,  it 
fetched"2«.  Qd.  a  pound ;  now,  perfectly  pure  sal  ammoniac  may  be  had  at  one  fifth  part 
of  that  price. 

Various  animal  offals  develop  during  their  spontaneous  putrefactive  fermentation,  or 
their  decomposition  by  heat,  a  large  quantity  of  free  or  carbonated  ammonia,  among  their 
volatile  products.  Upon  this  principle  many  sal  ammoniac  works  have  been  established. 
In  the  destructive  distillation  of  pitcoal,  there  is  a  considerable  quantity  of  ammoniacal 
products,  which  are  also  worked  up  into  sal  ammoniac. 

The  first  attempts  made  in  France  to  obtam  sal  ammoniac  profitably  in  this  manner, 
failed.  A  very  extensive  factory  of  the  kind,  which  experienced  the  same  fate,  was 
under  the  superintendence  of  the  celebrated  Baume,  and  affords  one  out  of  a  thousand 
mstances  where  theoretical  chemists  have  shown  their  total  incapacity  for  conducting 
operations  on  the  scale  of  manufacturing  economy.  It  was  established  at  Gravelle  near 
Charenton,  and  caused  a  loss  to  the  shareholders  in  the  speculation  of  upwards  of 
400,000  francs.  This  result  closed  the  concern  in  1787,  after  a  foolish  manipulation  of 
27  years.  For  ten  years  after  that  event,  all  the  sal  ammoniac  consumed  in  France  was 
imported  into  it  from  foreign  countries.  Since  then  the  two  works  of  MM.  Payen 
and  Pluvinet  were  mounted,  and  seem  to  have  been  tolerably  successful.  Coal  soot  was, 
prior  to  the  introduction  of  the  gas-works,  a  good  deal  used  in  Great  Britain  for  obtaining 
sal  ammoniac.  In  France,  bones  and  other  animal  matters  are  distilled  in  large  iron  retorts, 
for  the  manufacture  of  both  animal  charcoal  and  sal  ammoniac. 

These  retorts  are  iron  cylinders,  2  or  3  feet  in  diameter,  and  6  feet  long.    Fins  1222 
and  1223,  show  the  form  of  the  furnace,  and  the  manner  in  which  the  cylinders  art 


1222 


1223 


arranged ;  the  first  being  a  longitudinal,  the  second  a  transverse  section  of  it.  A,  the  ash- 
pits under  the  grates ;  b,  the  fireplaces,  arched  over  at  top ;  c,  the  vault  or  bench  of  fire- 
bricks, perforated  inside  with  eight  flues  for  distributing  the  flame ;  d,  a  great  arch,  with 
a  triple  voussoir  d  d ,  <f",  under  which  the  retorts  are  set.  The  first  arch  d,  is  perforated 
with  twenty  vent-holes;  the  second,  with  four  vent-holes;  through  which  the  flame 
passes  to  the  third  arch,  and  thence  to  the  common  chimney-stalk.    The  retorts  e,  are  shut 


ii 


1      1 


;.  til 


572 


SAL  AMMONIAC. 


by  the  door  t'  (fig.  1223),  luted,  and  made  fast  with  screw-bolts.  Their  other  ends  e"  ter- 
minate in  tubes  f,fyf,  which  all  enter  the  main  pipe  h.  The  condensing  pipe  proceeds 
slantingly  downwards  from  the  further  end  of  A,  and  dips  into  a  large  sloping  iron  cylinder 
immersed  in  cold  water.     See  Gas-light  and  Stove,  for  a  belter  plan  of  furnace. 

The  filters  used  in  the  large  sal  ammoniac  works  in  France  are  represented  in  fig, 
1224.  The  apparatus  consists — 1.  of  a  wooden  chest  c,  lined  with  lead,  and  which  it 
turned  over  at  the  edges ;  a  socket  of  lead  6,  soldered  into  the  lowest  part  of  the  bottom, 
serves  to  discharge  the  liquid ;  2.  of  a  wooden  crib  or  grating  formed  of  rounded  rods, 
as  shown  in  the  section  c,  c,  and  the  plan  d ;  this  grating  is  supported  one  inch  at  least 
above  the  bottom,  and  set  truly  horizontal,  by  a  series  of  wedges;  3.  of  an  open 
fabric  of  canvass  or  strong  calico,  laid  on  the  grating,  and  secured  over  the  edges, 
so  as  to  keep  it  tense.     A  large  wooden  reservoir  /,  lined  with  lead,  furnished  with  a 


1224 


.vi^f»<^<^<»<^<v»^»^^a 


cover,  IS  placed  under  each  of  the  filters ;  a  pump  throws  back  once  or  twice  upon  tne 
filters  what  has  already  passed  through.  A  common  reservoir  g,  below  the  others,  may 
be  made  to  communicate  at  pleasure  with  one  of  them,  by  means  of  intermediate  stop- 
cocks. 

The  two  boilers  for  evaporating  and  decomposing  are  made  of  lead,  about  one  quarter 
of  an  inch  thick,  set  upon  a  fire-brick  vault,  to  protect  them  from  the  direct  action 
of  the  flame.  Through  the  whole  extent  of  their  bottoms  above  the  vault,  horizontal 
cast-iron  plates,  supported  by  ledges  and  brick  compartments,  compel  the  flame  and 
burned  air,  as  they  issue  from  the  arch,  to  percur  many  sinuosities  before  they  pass  up 
the  chimney.  TMs  floor  of  cast  iron  is  intended  to  support  the  bottom  of  the  boiler, 
and  to  diffuse  the  heat  more  equably.  The  leaden  boilers  are  surrounded  with  brick- 
work, and  supported  at  their  edges  with  a  wooden  frame.  They  may  be  emptied  at 
pleasure  into  lower  receivers,  called  crystallizers,  by  means  of  leaden  syphons  and  long- 
necked  funnels. 

The  crystallizers  are  wooden  chests  lined  with  lead,  15  inches  deep,  3  or  4  feel 
broad,  and  from  6  to  8  feet  long ;  and  may  be  inclined  to  one  side  at  pleasure.  A  round 
cistern  receives  the  drainings  of  the  mother-waters.  The  pump  is  made  of  lead,  hardened 
with  antimony  and  tin. 

The  subliming  furnace  is  shown  in  figs,  1225  and  1226,  by  a  transverse  and  longitudi- 
nal section,  a  is  the  ash-pit ;  6,  the  grate  and  fire-place ;  c,  the  arch  above  them.  This 
arch,  destined  to  protect  the  bottles  from  the  direct  action  of  the  fire,  is  perforated  with 
vent-holes,  to  give  a  passage  to  the  products  of  combustion  between  the  subliming  vessels. 
df  d,  are  bars  of  iron,  upon  which  the  bottoms  of  the  bottles  rest ;  e,  stoneware  bottles, 
protected  by  a  coating  of  loam  from  the  flame. 


1226 


1227 


BDOOODOOOO 


oosoaoDooo 


\n\c 

122« 

h            6' 

b' 

\     A     1 

SAL  AMMONLAO. 


678 


^g.  1227.  shows  the  cast-iron  plates,  a,  b,  c,  which,  placed  above  the  vaults,  receive 
each  two  bottles  in  a  double  circular  opening. 

At  the  extremity  of  the  above  furnace,  a  second  one,  called  the  dner,^g.  1228.,  receives 
the  products  of  the  combustion  of  the  first,  at  a,  under  horizontal  cast-iron  plates,  and 
upon  which  the  bottom  of  a  rather  shallow  boiler  b  rests.  After  passing  twice  under 
these  plates,  round  a  longitudinal  brick  partition  b,  b\  b",  the  products  of  combustion 
enter  the  smoke  chimney  c.     See  plan,  fia.  1229. 

The  boiler  set  over  this  furnace  should  have  no  soldered  joints.  It  may  be  3^  feet 
broad,  9  or  10  feet  long,  and  1  foot  deep.  The  concrete  sal  ammoniac  may  bt  crushed 
under  a  pair  of  edge  mill-stones,  when  it  is  to  be  sold  in  powder. 

Bones,  blood,  flesh,  horns,  hoofs,  woollen  rags,  silk,  hair,  scrapings  of  hides  and 
leather,  &c.,  may  be  distilled  for  procuring  ammonia.  When  bones  are  used,  the 
residuum  in  the  retort  is  bone  black.  The  charcoal  from  the  other  substances  will  serve 
for  the  manufacture  of  Prussian  blue.  The  bones  should  undergo  a  degree  of  calcination 
beyond  what  the  ammoniacal  process  requires,  in  order  to  convert  them  into  the  best  bone 
black ;  but  the  other  animal  matters  should  not  be  calcined  up  to  that  point,  otherwise  they 
are  of  little  use  in  the  Prussian  blue  works.  If  the  bones  be  calcined,  however,  so  highly 
as  to  become  glazed,  their  decoloring  power  on  sirups  is  nearly  destroyed.  The  other 
substances  should  not  be  charred  beyond  a  red-brown  heat. 

The  condensed  vapors  from  the  cylinder  retorts  afibrd  a  compound  liquor  holding  car 
bonate  of  ammonia  in  solution,  mixed  with  a  large  quantity  of  empyreumatic  oil,  which 
floats  at  top.     Lest  incrustations  of  salt  should  at  any  time  tend  to  obstruct  the  tubes,  a 
pipe  should  be  inserted  within  them,  and  connected  with  a  steam  boiler,  so  as  to  blow 
steam  through  them  occasionally. 

The  whole  liquors  mixed  have  usually  a  density  of  8®  or  9°  Baume  (1060).  The 
simplest  process  for  converting  their  carbonate  of  ammonia  into  muriate,  is  to  saturate 
them  with  muriatic  acid,  to  evaporate  the  solution  in  a  leaden  boiler  till  a  pellicle 
appears,  to  run  it  off  into  crystallizers,  and  to  drain  the  crystals.  Another  process  is,  to 
decompose  the  carbonate  of  ammonia,  by  passing  its  crude  liquor  through  a  layer  of 
sulphate  of  lime,  3  or  4  inches  thick,  spread  upon  the  filters,  fig.  1224.  The  liquor  may 
be  laid  on  with  a  pump ;  it  should  never  stand  higher  than  1  or  2  inches  above  the 
surface  of  the  bruised  gypsum,  and  it  should  be  closely  covered  with  boards,  to  prevent 
the  dissipation  of  the  volatile  alkali  in  the  air.  When  the  liquor  has  passed  through 
the  first  filter,  it  must  be  pumped  upon  the  second;  or  the  filters  being  placed  in  a  terrace 
form,  the  liquor  from  the  first  may  flow  down  upon  the  second,  and  thus  in  suc- 
cession. The  last  filler  shouH  be  formed  of  nearly  fresh  gypsum,  so  as  to  ensure  the 
thorough  conversion  of  the  carbonate  into  sulphate.  The  resulting  layers  of  carbonate 
of  lime  should  be  washed  with  a  little  water,  to  extract  the  sulphate  of  ammonia  inter- 
posed among  its  particles.  The  ammoniacal  liquor  thus  obtained  must  be  completely 
saturated,  by  adding  the  requisite  quantity  of  sulphuric  acid ;  even  a  slight  excess  of  acid 
can  do  no  harm.  It  is  then  to  be  evaporated,  and  the  oil  must  be  skimmed  off  in  the  course 
(^the  concentration.  When  the  liquid  sulphate  has  acquired  the  density  of  about  1*160, 
sea  salt  should  be  added,  with  constant  stirring,  till  the  whole  quantity  equivalent  to  the 
double  decomposition  be  introduced  into  the  lead  boiler. 

The  fluid  part  must  now  be  drawn  off  by  a  syphon  into  a  somewhat  deep  reservoir, 
where  the  impurities  are  allowed  to  subside ;  it  is  then  evaporated  by  boiling,  till  the 
sulphate  of  soda  falls  down  in  granular  crystals,  as  the  result  of  the  mutual  reaction  of  the 
sulphate  of  ammonia  and  muriate  of  soda ;  while  the  more  soluble  muriate  of  ammonia 
remains  in  the  liquor.  During  this  precipitation,  the  whole  must  be  occasionai.y  agitated 
with  wooden  paddles ;  the  precipitate  being  in  the  intervals  removed  to  the  cooler  portion 
of  the  pan,  in  >rder  to  be  taken  out  by  copper  rakes  and  shovels,  and  thrown  into  draining- 
hoppers,  plac?a  near  the  edges  of  the  pan.  The  drained  sulphate  of  soda  must  be  after- 
wards washed  with  cold  water,  to  extract  all  the  adhering  sal  ammoniac. 

The  liquor  thus  freed  from  the  greater  part  of  the  sulphate,  when  sufliciently  concen- 
trated, IS  to  be  drawn  off  by  a  lead  syphon,  into  the  crystallizers,  where,  at  the  end 
of  20  or  30  hours,  it  affords  an  abundant  crop  of  crystals  of  sal  ammoniac.  The  mother- 
water  may  then  be  run  off,  the  crystallizers  set  aslope  to  drain  the  salt,  and  the  salt  itself 
must  be  washed,  first  by  a  weak  solution  of  sal  ammoniac,  and  lastly  with  water.  It 
must  be  next  desiccated,  by  the  apparatus  yig.  1228,  into  a  perfectly  dry  powder,  then 
put^mto  the  subliming  stoneware  balloons,  by  means  of  a  funnel,  and  well  rammed  down. 
The  mouth  of  the  bottle  is  to  be  closed  with  a  plate  or  inverted  pot  of  any  kind.  The 
fire  must  be  nicely  regulated,  so  as  to  effect  the  sublimation  of  the  pure  salt  from  the 
under  part  of  the  bottle,  with  due  regularity,  into  a  white  cake  in  the  upper  part.  The 
neck  of  the  bottle  should  be  cleared  from  time  to  time  with  a  long  steel  skewer,  to 


574 


SAL  AMMONIAC. 


SALTS. 


575 


li 


the  internal  surface  of  the  pots ;  the  vapour  being  received  and  condetised  into  cakeSj 
^Uh^  bTuoons  of  green  glaTset  over  thlir  mouths.  The  salt,  when  taken  out  and  fr^ed 
bv  scraping  from  any  adhering  ochreous  or  other  impurities,  is  ready  for  the  marfee^ 
b^ine  sold  in  hollow  spherical  masses.  The  residuum  in  the  pots  or  bottles  may  be 
partially  worked  up  in  another  operation.  The  greatest  evil  is  produced  by  the  mixture 
or  even  contact  of  iron,  because  its  peroxide  readily  rises  in  vapour  with  the  sal  ammoniac, 

and  tinges  it  of  a  red  or  yellow  colour.  .      ,  ,.  r  ^i.  v»  ;«*^ 

Tlie  most  ordinary  process  for  converting  the  ammomacal  liquor  of  the  gas-works  into 
gal  ammoniac,  is  to  saturate  it  with  sulphuric  acid,  and  to  decompose  the  sulphate  thus 
formed,  by  the  processes  above  described.  But  muriatic  acid  will  be  preferred,  where  it 
is  as  cheap  as  sulphuric  of  equivalent  saturating  power;  because  a  tolerably  pure  sal 
ammoniac  is  thereby  directly  obtained.  As  the  coal-gas  liquor  contains  a  good  deal  of 
sulphuretted  hydrogen,  the  saturation  of  it  with  acid  should  be  so  conducted  as  to  burn 
the  disengaged  noxious  gases  in  a  chimney.  Formerly  human  urine  was  very  extensively 
employed,  both  in  this  Country  and  in  France,  in  the  manufacture  of  sal  ammonmc  ;  but 
Bince  the  general  establishment  of  gas-works  it  has  been,  I  believe,  abandoned,     llie  pro- 

cess  was  exceedingly  offensive.  *    x  j- i.„.  ♦!,.«« 

The  best  white  sal  ammoniac  is  in  spheroidal  cakes  of  about  one  foot  diameter,  three 
or  four  inches  thick  in  the  middle,  somewhat  thinner  at  the  edges  and  is  semi-transparent 
or  translucent.  Each  lump  weighs  about  one  quarter  of  a  cwt  As  it »«  easily  volatil^ed 
by  heat,  it  may  be  readily  examined  as  to  its  sophistication  with  other  salts.  Sal  ammonmc 
hL  a  certain  tenacity,  and  is  flexible  under  the  hammer  or  pestle.  It  is  principally  used 
in  tinning  of  cast-iron,  wrought-iron,  copper,  brass,  and  for  makmg  the  various  ammomacal 

^inScaUacToT/near  Glasgow,  7200  gallons  of  ammoniacal  liquor,  ^^^f ^"f JTff^'^y 
from  the  gas-works,  are  treated  as  follows  :-The  liquor  is  first  'f.t'fi«^.^y,^'«.Xii.J? 
from  a  waggon-shaped  wrought-iron  boiler,  into  a  square  cistern  of  iron  Imed  y«h  l^^^ 
4500  lbs.  of  sulphuric  acid,  of  specific  gravity  1-625.  are  then  slowly  added  to  the  sorn^ 
what  concentrate  distilled  water  of  ammonia.  The  produce  is  2400  gallons  of  8«lphate 
of  ammonia,  sUghtly  acidulous,  of  specific  gravity  1;150,  being  of  such  ftrength  as  to 
deposit  a  few  crystals  upon  the  sides  of  the  lead-lined  iron  tank  m  which  the  sahne  com- 
bination  is  made.     It  is  decomposed  by  common  salt  „Vo:  Jnn«n 

From  the  7200  gallons  of  the  first  crude  liquor,  900  gallons  of  tar  are  ^ot  by  subsidence 
and  200  gallons  of  petroleum  are  skimmed  oflf  the  surface.    The  tar  is  converted,  by  a 
moderate  boiling  in  iron  pans,  into  good  pitch. 

A  patent  wa?  oblaineJin  1840,  for  improvements  m  the  "'jnujacture  of  this  article,  b^ 
Mr.  H.  Waterton.  Two  modes  of  operating  are  described ;  the  first  consists  fJ^f'^SJ' 
saturated  solution  of  common  salt  in  water,  and  mixing  with  it  a  quantitjr  of  finely  pul- 
verised carbonate  of  ammonia,  about  equal  in  weight  to  the  salt  contamed  in  the  soluti^ 
The  mixture  is  agitated  in  a  close  vessel  for  six  or  eight  hours,  and  as  """^^f^'Tbonic^ 
is  infused  therein  as  it  will  absorb  (but  the  introduction  of  the  gas  is  not  absolutely  ne^s- 
sary,  although  the  patentee  prefers  it);  the  liquid  is  then  separated  ^^^^^^^  jl'^^^' 
by  filtration  and  pressure.  The  solid  matter  is  chiefly  bi-carUnate  of  soda,  and  the  bquid 
holds  in  solution  muriate  and  carbonate  of  ammonia,  and  common  salt,  and  sometimes  a 

small  portion  of  the  bi-carbonate  of  soda,  ,       ^      r         ^-    u-;„«  ^;-_ 

The  liquid  is  now  placed  in  a  distilling  vessel,  and  the  carbonate  of  ammonia  being  dis- 
tiUed  ovlr  into  a  suitable  receiver,  a  solution  of  munate  of  ammonia  and  common  ^  t 
remains  in  the  stilL  This  solution  is  evaporated,  by  heat,  to  such  »  consistency  a^  will 
cause  the  separation  of  the  common  salt,  by-crystallisation,  and  the  salt,  thus  crystoll^^d 
U  evaporated  from  the  liquid  by  any  convenient  method.  The  liquid  ^t^en  evaporated 
until  it  attains  the  proper  specific  gravity  for  crystallismg,  and  it  is  transferred  in  osmta. 
ble  utensils  for  th^  purpose.  The  crystals,  produced  by  these  ^f  "«'.«•;«  "^'^J^iC 
muriate  of  ammonia,  anS  then  pressed  and  dried  may  be  brought  to  market  without 
further  preparation,  or  they  may  be  sublimed  into  cake  sal  ammoniac. 

The  otheV  mode  of  manufacturing  sal  ammomac  consists  m  takmg  *  quantity  of  hquid. 
containing  ammonia,  either  in  the  caustic  state  or  combined  with  carbon,  ^^y^'iosulphur.^ 
or  hydrocyanic  acid  (such  as  gas  ammoniacal  liquor,  or  bone  ammomacal  l^q^or)  aiid 
rectifying  it,  bv  distillation,  until  the  distilled  portion  ^ontams  from  twenty  to  twenty- 
five  per  ?ent  of  carbonate  of  ammonia.  If  the  h^quid  contains  any  other  ^j^s^an  those 
above  mentioned,  a  sufficient  quantity  of  lime  is  used  in  the  distillation  to  decompose  the 

""iSrih^UleVliquid  being  now  mixed  with  as  large  a  quantity  of  powdered  common 
salt  as  it  wiU  dissolve,  is  agitated  for  several  hours,  and  as  °™"<^V  ^!^"'^/J;^^/!t 
is  infused  into  it  as  it  will  absorb.  The  remainder  o  the  operation  is  the  same  a^ 
before  described  in  the  first  method  of  manufacturing  sal  ammomac-^Newton  s  Jmmal, 

C.  S.  xxii.  35 

SALAMSTONE.    See  Lapidabt. 


SALEP   or  SALOUP,  is  the  name  of  the  dried  tuberous  roots  of  the  OrchU,\m' 
oofttlfrom  Pe^^and  Asia  Minor,  which  are  the  product  of  a  great  many  ?Pecies  of  the 

i^rAuZsrJaotZ^n  eountry  were  cleaned,  scraped  steeped  for  a  short  t^e  m 

^^po^str^rsS'rr.^^^^ 

J;fS,e  terk  onL  whUe^iUow  (Saiix  att„)^ 

wme  other  willows,  and  some  poplars.    It  has  a  very  bit  er  taste. 

SAL  PRUNELLA,  is  fused  nitre  cast  into  cakes  or  tails. 

SAL  VOLATILE,  is  sesquicarbonate  of  ammonia. 

f^,^^^^6^h^^lt:tS^^li^os,^'^^'>  of  soda  and  an»>oni. 

SALT  OF  AMBER,  is  succmic  acid. 

SALT  OF  LEMONS,  is  citric  acid. 

SALT  OF  SATURN,  is  acetate  of  lead. 

SALT  OF  SODA,  is  carbonate  of  soda. 

SALT  OF  SORREL,  is  bi-oxalate  of  potassa. 

SALT  OF  TARTAR,  is  carbonate  of  potassa. 

SALT  OF  VITRIOL,  is  sulphate  of  zinc. 

SALT  PERLATE,  is  phosphate  of  soda. 

SALTPETRE,  is  nitre,  or  nitrate  of  potassa. 

•  'siL?S,'are1.S^^^^^^^^  compounds,  anciently  studied  under  the 

fireek  title  of  Ha/ur^v.  At  one  period  every  inorganic  substance  readily  soluble  m 
water  was  rec-Sdedis  a  sS  ;  and'^aflerwaids,  every  substance  soluble  in  five  hundred 
ti^esitr^i-ht  of  water.  Thus  both  acid  and  alkaline  bodies  cam-  to  be  enrol  cd  among 
^ts.  bariatTerly,  the  combinations  of  the  acids  witii  alkalis,  earths,  and  metaiuz  calces 
(^ow  s?yled  ox^^^^^^^  were  aloae  thought  to  be  entitled  to  the  denominalion  of  ^Its.  m 
conLuntce  of  thei  resemblance  in  appearance,  and  supposed  analogy  in  composiuon, 
tneuUna^  salt  Since  Sir  H.  Davy  demonstrated  that  this  substance  contain«^  neither 
icid  o^iraYi^e  r^^^^^^^^  that  it  consisted  of  chlorine  and  the  metal  sodium  U« 
JeneraUty  of  chemists  found  it  impossible  to  include  salts  under  one  categorjr  of  con»U. 
tut"ou ;  while  a  few  hare  rashly  offered  to  cut  the  knot,  by  excluding  from  the  saline 
family,  chloride  of  sodium,  the  patriarch  of  the  whole. 

StUts  may  be  justly  divided  into  three  orders :  ^        .,     x.       -a       «».i«««»-. 

1.  The  binary,  consisting  of  two  single  members;  such  as  the  bromides,  cwonaes, 
cyanides,  fiuorides,  iodides,  carburets,  phosphurets,  sulphurets,  ^-C- 

2.  The  bi-binary,  consisting  of  two  double  members;  such  as  the  borates,  bromaie*, 
carbonates,  chlorates,  sulphates,  sulphites,  hyposulphites,  sulphohydrates,  &c. 

3  The  ternary,  consisting  of  two  single  members  of  one  genus,  and  one  member  ol  an- 
other ;  such  as  the  boro-fluorides,  silico-fluorides,  sulpho-cyanides,  chloriodides,  &c. 

The  species  of  each  order  may  exist  in  three  states,  constituting  neutral  salts,  super- 
salts,  and  subsalts ;  as  for  example,  the  chloride  of  sodium,  the  bisulphate  of  potassa, 
the  subnitrate  of  lead,  &c.  .     ,        u  e 

In  the  above  arrangement,  cyanogen  is  allowed  to  represent  a  simple  substance,  trom 
its  forming  analogous  compounds  with  chlorine  and  iodine.  The  neutral  state  of  salts  is 
commonly  indicated  by  their  solutions  not  changing  the  colors  of  litmus,  violets,  or  red 
cabbage ;  the  sub-state  of  salts,  by  their  turning  the  violet  and  cabbage  green  ;  and  the 
super-state  of  salts,  by  their  changing  the  purple  of  litmus,  violets,  and  cabbage,  red;  but 
to  the  generality  of  this  criterion  there  are  some  exceptions.  The  atomic  theory  may  be 
advantageously  resorted  to,  in  this  predicament.  1.  When  one  prime  equivalent  of  the 
one  member  (whether  single  or  double)  of  a  salt,  combines  with  one  prime  of  the  other 
member,  a  neutral  salt  is  the  result,  as  in  chloride  of  sodium  or  nitrate  of  potassa.  Z. 
When  two  primes  of  the  electro-negative  member  combine  with  one  prune  of  the 
electro-positive,  a  supersalt  is  formed,  as  bichloride  of  tin,  or  bisulphate  of  potassa. 
3.  When  one  prime  of  the  electro-negative  member  combines  with  two  or  more  prim^ 
of  the  electro-positive,  a  subsalt  is  produced,  as  the  subacetate  and  subchromate  of 

SALT*    The  salt  manufacture  of  Droitwich,  Worcestershire,  existed  at  a  very  early 
period :  it  is  mentioned  as  in  operation  at  the  time  of  the  Roman  invasion;  then  it  was 


676 


m 


SALT,  SEA. 


madei,  „se  to  .he  surface  t&'t  ^r"  ^'^  o^&Ct"''  «''='«  o?"^"™ 
the  freshwater  spring.  ;,  *'";™''  '»  wo^'e;  for  in  ascend^^  K  '^''.'"S-  Tliia  process 
tie  salt,  which  wm  TOnduXj  k     ^  ""^  '"'^wed  in  strenJ^f  ^T^''  ""d  miiins  wUh 

There    has   been   recently  nhi  •     ^  '«rmerly,  it  varied  between 

salt:    bv  usino- T,«.       '^^tJUiiJ    Obtained    a   nafon*    r        .  ""cen 

per  annum  manufactured  „?^l!-l''''''  ""''  ^5"»toI.    11  er'  »rl    "^  "  ""P"--'*!  largelv 
purposes;  the  rest  Is  utedil^fl* /"'"«'  «<»»  are  used  f.,r    I  "^^'''''''f  '0,000  folS 

varies  from  2  0  to  2-^  "  JP'""'  ""d  softer  than  ~lc„rt  "'"■* '  "  ''  ""rly  as  hard  21 
Posure  to  heat,  it  coS,o„rdi;.''"'''' '' '»  ~'»rlesMrinTce'„f''"-  "'  'P^'fl'  g™vi? 
ftsion  at  an  elevated  t^^iLlf'*P"».'« ;  but  some  Cdi  „r  '  ?"■  '™"sparent.  On™, 
been  oriyinally  subjected  to^he*'?  '''""'"^'"ce  which  h  J  J  '*'■  ""'"  W^'Ir  into 
According  to  M/GaTl,  °  *c  'mT  "^  ^'^-  '^"^  '» '^''" !««"«« 

35  81  parts  of  the'sajt  .IT  "*■  *"'"  *"™'ve- 
35-88  "  3'  •'  'emperature  570»  ^r 

37- J4  62-5» 

iwr  ,.  ^0-38  ~  ]40-0» 

Jime,  niagnesia,  soda,  muriatlV^?     "^""'"^  ^^^  qualities     Tho        ^^^  '*''"^J"n  matters 
«late  of  diifusion,  fcc!     """''*  ^^^agnesia  and  pota  h  4u  Jen   '  vi''  V^^  ^^^^^^^^^  «? 
Muriate  of  potash  has  hpo     ^  ""amen,  oxyde  of  iron,  clay  in  a 

Berchtesgaden  in  Bavark  of  R  n'-^'-'^'  '"  the  waters  of  th.  • 

of  Rosenheim.  ^"^'^^  ^'^H-U-n  in  the  territor?  oT&L^^rrr^  •"  l'^  ^^^"^^"^  ^^ 

The  more  heterogeneous  the  ..n  .u  ^i2t>onrg,  and  m  the  salt  springs 

different  saline  constituenTs  •L'flV^^  "^^^  .  ^ 

may  serve  to  show  approxt'«r.f   t"'  *  ^^"<^ate  hyi-imeter  ni     ""^?P^«^«'  affinity  of  itt 
of  a  saturated  solution  of  iTf^^  *^^  ''"^^'^y  of  the?X    T  '/i""5^^  ^"  saturated  brne 

«>lutio?.  ^^   ^^^  ^^-«s  and'silin^^  eUit^utn^U^^^ -f«^  VenZi^Y^ 

the^dri&h^*-  ^"  ^^^  «>-  of  this  salt  th  ^'  ^'"   ''  ^^  ^'^ 

.haped,Thlt?V^e:-^^^^^^ 

jurface  of  the  saline  soS'^-'     ?  *^  *  ^^"ow  rec'an"n,«    '  *^^"^.^he  funnel  or  hop^r! 

floating  cube,  upon  wMch  r     "*  I^^  *^0"^se  of  its  evarS"^-  ^^'^"^'^^  ^^ich  forms  a?^* 


SALT,  SEA.  577 

A  Table  of  the  results  of  the  Analyses  of  several  varieties  of  Culinary  Salt. 


Chloride 

Muriate 

Muriate 

Sulphate 

Sulphate 

Sulphate 

Clay  and    Oxyd«  | 

Origin  of  the  Salt. 

of 

of  Mag- 

<.f 

of 

of  Mag- 

of 

other  ill- 

of 

Sodium. 

nesia. 

Lime. 

Soda. 

nesia. 

Lime. 

soluble 
bodies. 

iron. 

Sal-^emofVicJ'^!;^^^ 
(  red 

99-30 
99-80 

^^^ 

— 

_ 

— 

0005 

0-020 
0-002 

Cheshire, 

crushed 

98-33 

0-02 

— 

— 

— 

0-65 

— 

0-002 

Salt  from  Salt  Sprintas  : 

Schonbeck,  Westphalia 

93-90 

0-30 

— 

1-00 

0-80 

M-""'  V^^"' 

97-17 

0-25 

— 

2-00 

0-58 

93-59 

0-61 

— 

5-55 

0-25 

Chateau  Salins 

97-82 

2-12 

White  of  Sulz       - 

96-88 

3-12 

Ludwisshall,       middle 

grained 

99-45 

— 

— 

0-05 

— 

0-28 

Koenigsborn,  Westphalia 

95-90 

— 

0-27 

— 

— 

1-10 

Sea  salt,  half  white 

97-20 

0-064 

— 

— 

0-050 

0-120 

0-070 

96- 
93-55 

0-30 

^_^ 

0-45 

2-35 

Common  Scottish  salt 

2-80 

— 

1-75 

1-50 

l.vmirtirton,  common    - 

93-7 

l-I 

— 

— 

3-50 

1-50 

2-00 

9R-8 

n.R 

_ 

^^^ 

,  0-5 

0-1 

Cheshire,  stoved 

98-25    0-075 

0-025 

— 

1-55 

The  geological  position  of  rock  salt  is  between  the  coal  formation  and  the  lias,  Th« 
great  rock-salt  formation  of  England  occurs  within  the  red  marly  or  new  red  sandstone, 
the  hunttr-sandstein  of  the  Germans,  so  called,  because  its  colors  vary  from  red  to 
salmon  and  chocolate.  This  mineral  stratum  frequently  presents  streaks  of  light  blue, 
verdigris,  buff,  or  cream  color;  and  is  chiefly  remarkable  for  containing  considerable 
masses  or  beds  of  gypsum.  At  Northwich,  in  the  vale  of  the  Weaver,  the  rock  salt 
consists  of  two  beds,  together  not  less  than  60  feet  thick,  which  are  supposed  to  con- 
stitute large  insulated  masses,  about  a  mile  and  a  half  long,  and  nearly  1300  yards 
broad.  There  are  other  deposites  of  rock  salt  in  the  same  valley,  but  of  inferior  im- 
portance. The  uppermost  bed  occurs  at  75  feet  beneath  the  surface,  and  is  covered 
with  many  layers  of  indurated  red,  blue,  and  brown  clay,  inlerstralified  more  or  less 
with  sulphate  of  lime,  and  interspersed  with  arsillacc  »us  marl.  The  second  bed  of  rock 
salt  lies  31^  feet  below  the  first,  being  separated  fron  it  by  layers  of  indurated  clay,  with 
veins  of  rock  salt  running  through  them.  The  lowest  ocd  of  salt  was  excavated  to  a  depth 
of  1 10  feet,  several  years  ago. 

The  beds  or  masses  of  rock  salt  are  occasionally  so  thick,  that  they  have  not  been  yet 
bored  through,  though  mined  for  many  centuries.  This  is  the  case  with  the  immense 
mass  of  Wieliczka,  and  the  lower  bed  at  Northwich.  But  in  ordinary  cases,  this 
thickness  varies  from  an  inch  or  two  to  12  or  15  yards.  When  the  strata  are  thin, 
they  are  usually  numerous ;  but  the  beds,  layers,  or  masses  never  exhibit  throughout  a 
great  extent  any  more  than  an  illusory  appearance  of  parallelism  ;  for  when  they  arc 
explored  at  several  points,  enlargements  are  observed,  and  such  diminutions  as  cause 
the  salt  to  disappear  sometimes  altogether.  This  mf.neral  is  not  deposited,  therefore,  in 
a  geolosical  stratum,  but  rather  in  lenticular  masses,  of  very  variable  extent  and  thick- 
ness, placed  alongside  of  each  other  at  unequal  distances,  and  interposed  between  the 
coursec  of  'he  other  formations. 

Sometimes  the  rock  salt  is  disseminated  in  small  masses  or  little  veins  among  the  cal- 
careous and  argillaceous  marls  which  accompany  or  overlie  the  greater  deposites.  Bitu- 
men, in  small  particles,  hardly  visible,  but  distinguishable  by  the  smell,  occurs  in  all  the 
minerals  of  the  saliferous  system. 

It  has  been  remarked,  that  the  plants  which  grow  generally  on  the  sea  shores,  such  as 
the  Triglochinum  maritimumj  the  Salicomia,  the  Salsola  kali,  the  Jster  trif»lium,  or  fare- 
well to  summer,  the  Glaux  maritima,  &c.,  occur  also  in  the  neighborhood  of  salt  mines 
and  salt  springs,  even  of  those  which  are  most  deeply  buried  beneath  the  surface. 

The  interior  of  rock-salt  mines,  afler  digging  through  the  strata  of  clay  marl,  &c.  is 
extremely  dry;  so  that  the  dust  produced  in  the  workings  becomes  an  annoyance  to  the 
miners,  thouch  in  other  respects  the  excavations  are  not  at  all  insalubrious. 

Salt  springs  occur  nearly  in  the  same  circumstances,  and  in  the  same  geological  form. 


578 


SALT,  SEA. 


SALT,  SEA. 


579 


I 


m  \    ! 


*tion  as  the  sail  rock.  It  has  been  noticed  that  salt  spines  issne  in  Mnem!  from  thm 
npper  portion  of  the  saliferous  strata,  principally  froJS.fS^'cl!rm^sV^^ 
however  occur,  where  the  salt  springs  are  not  accompanied  by  rock  salt,  and  where  t^ 
^mroTl^T  '"  "'""^  ^''"  '^'  "^""^^  themselves,  which  thus^oistUutrS^e  only 
It  has  been  imagined  that  there  are  two  other  periods  of  geological  formation  of  this 
•ubstance ;  one  much  more  ancient,  belonging  to  the  transition  series  of  rX  the  othe? 
relatively  modern  among  secondary  strata.  To  the  former  has  been  relrred  the  salffor! 
ma  .on  of  Bex,  that  of  Cardonne,  Sec.  But  M.  Brongniart  assigns  valid  reasons  f^^^ 
S^%h^''  ^"PPosition.  M.  Beudant,  indeed,  refers  to  the  secondary  strata  a^ve  t^^ 
chalk,  the  rock-salt  formation  of  Wieliczka,  and  of  the  base  of  the  Carpathians  placng 
these  among  the  plastic  clay  and  lignites.  p«""ans ,  piacing 

The  mines  of  rock  salt  do  not  appear  to  possess  any  determiftate  elevation  unon  the 
surface  of  the  earth  Immense  masses  of  it  are  met  with  at  very  great  depths  below  the 
level  of  the  sea,  (the  mine  of  Wieliczka  is  excavated  860  feet  beneath  the  s^nTanS 
others  exis   at  a  considerable  altitude,  as  that  of  Haliein  near  Salzbourg,  which  is  3300 

SS^"^j;V  h  ^^^^.l«^^^^  ''\^^^  '^^  ^«Ii"^  ^ock  of  Arbonne  in  Savoy,  which  is  ne^iy 
4000  feet  higher,  situated  at  the  great  elevation  of  7200  feet  above  the  level  of  the  sea 

Inh.r'f'^"'"'^^  '"'^^  ^^/io"f  P-'-petual  snow.  Therock  is  amass  of  saccharoid  and 
anhjdrous  gypsum,  imbued  with  common  salt,  which  is  extracted  by  lixiviation :  after 
which  the  gypsum  remains  porous  and  light.  i«"un,   aiier 

The  inland  seas,  salt  lakes,  and  salt  marshes,  have  their  several  localities  obvionslv 
independent  of  peculiar  geological  formations.  The  ocean  is,  however,  the  most  maS- 
cent  mine  of  salt,  since  this  chloride  constitutes  about  one  thirtieth  part  of  its  weight  • 
^hL^  ?h'7"''^  ^f""''^  throughout  its  waters,  when  no  local  cause  disturbs  trequil 
mao.naJt'  ^^'"^f  ^\  P^^P^^ion  of  salt  held  in  solution  in  the  open  sea,  is  38  parts  in 
1000,  and  the  smallest  32.  In  a  specimen  taken  by  Mr.  Wilkinson,  out  of  the  Red  Sea 
at  Berenice,  I  found  43  parts  of  salt  in  1000.     The  specific  gravity  of  the  water  was  1035, 

Were  it  requisite  to  extract  the  chloride  of  sodium  from  sea-water  bv  fuel  alone  manv 
countries  even  maritime,  would  find  the  process  too  costly.  The  salt  is  therefore  ibuT/- 
ed  from  It  in  two  different  manners;  1.  by  natural  evaiK)ration  alone ;  2.  by  natural  and 
ti^ffn^  ^^«P«;at.on  combined.  The  first  method  is  employed  in  w'arm  r^ is,  under 
the  form  of  saline  tanks,  or  brine  reservoirs,  called  also  brine-pits  These  are  lar^e 
shaUow  basins,  the  bottom  of  which  is  very  smooth,  and  formed  of  day.  They  are  el! 
cavated  along  the  sea-shore,  and  consist  of  —  ^      iney  are  ex- 

.nH't^Lll^^VK*^""''"*'''  ^^^^^^  ^^*"  ^^^  ^^^^^'  brine-pits,  which  is  dug  between  them 
and  the  sea.  This  reservoir  communicates  with  the  sea  by  means  of  a  channel  provided 
with  a  sluice.  On  the  sea-shore,  these  reservoirs  may  be  filled  at  high  water,  though  the 
tides  are  rather  inconvenient  than  advantageous  to  brine-pits.  j         e    luc 

2dly.  The  brine-pits,  properiy  so  called,  which  are  divided  into  a  number  of  compart- 
meats  by  means  of  little  banks.  All  these  compartments  have  a  communication  with  each 
other  but  so  that  the  water  frequently  has  a  long  circuit  to  make,  from  one  set  to  another 
Sometimes  it  must  flow  400  or  500  yards,  before  it  reaches  the  extremity  of  this  sort  of 
P.Knf.i!;v  Jr  ^*''.'7^^*vjJ««ns  have  a  number  of  singular  names,  by  which  they  arc 
techmcally  distinguished.    They  should  be  exposed  to  the  north,  north-east,  or  nor^ 

The  water  of  the  sea  is  le*  into  these  reservoirs  m  the  month  of  March,  where  it  » 
exposed  on  a  vast  surface  to  eYaporalion.  The  first  reservoir  is  intended  to  detain  the 
water  till  its  impurities  have  subsided,  and  from  it  the  other  reservoirs  are  supplial  as 
their  water  evaporates.  The  salt  is  considered  to  be  on  the  point  of  crystallizing  when 
tiie  water  begins  to  groAt  rec  Soon  after  this,  a  pellicle  forms  on  the  surface  which 
breaks,  and  falls  to  the  bottom.  Sometimes  the  salt  is  allowed  to  subside  in  the  first  com- 
partment;  at  others,  the  strong  brine  is  made  to  pass  on  to  the  others,  where  a  larger 

^^  ro  dSdVr^r  "^- '"  ^^^'^^  ^^^^  ^'^ '''' ''  ^'^^  -^'  -'^  ^^"  ^p-  '^* 

The  salt  thus  obtained  partakes  of  the  color  of  the  bottom  on  which  it  is  formed :  and 
IS  nence  white,  red,  or  gray. 

t»  tl^''^^f'  contains,  ii,  1000  parts,  25  of  chloride  of  sodium,  6-3  sulphate  of  magnesia. 
3-6  chloride  of  magnesium,  0-2  carbonate  of  lime  and  magnesia,  0-1  sulphate  of  lime,  be- 
l^^  5o'oo  ^'  sulphate  and  muriate  of  potash.  It  also  contains  iodide  of  sodium,  and 
bromide  of  magnesium.     Its  average  spec.  grav.  is  from  1*029  to  1-030 

Sea-water  and  weak  brines  may  be  cancentrated  either  by  the  addition  of  rock  salt 
by  spontaneous  evaporation  in  brine-pits  (see  supr^),  or  by  graduation.  Houses  for  the 
last  purpose  are  extensively  employed  in  France  and  Germany.  The  weak  brine  is 
pumped  into  an  immense  cistern  on  the  top  of  a  tower,  and  is  thence  allowed  to  flow 
down  the  surface  of  bundles  of  thorns  built  up  in  regular  walls,  between  parallel  wooden 
irames.    At  Saiza,  near  Schonebeck,  the  graduation-house  is  5817  feet  long,  the  thorn 


walls  are  from  33  to  52  feet  high,  m  diflferent  parts,  and  present  a  total  surface  ol 
25,000  square  feet.  Under  the  thorns,  a  great  brine  cistern,  made  of  strong  woodea 
planks,  is  placed,  to  receive  the  perpetual  shower  of  water.  Upon  the  ridge  of  the 
graduation-house  there  is  a  long  spout,  perforated  on  each  side  with  numerous  holes,  and 
furnished  with  spigots  or  stopcocks  for  distributing  the  brine,  cither  over  the  surface  of 
the  thorns,  or  down  through  their  mass  ;  the  latter  method  affording  larger  evaporation. 
The  graduation-house  should  be  built  lengthwise  in  the  direction  of  the  prevailing 
wind,  with  its  ends  open.  An  experience  of  many  years  at  Salza  and  Durrenberg  has 
shown,  that  in  the  former  place  graduation  can  go  on  258,  and  in  the  latter  207  days,  on 
an  average,  in  the  year ;  the  best  season  being  from  May  till  August.  At  Diirrenbei^, 
3,596,561  cubic  feet  of  water  are  evaporated  annually.  According  to  the  weakness  of 
the  brine,  it  must  be  the  more  frequently  pumped  up,  and  made  to  flow  down  over  the 
thorns  in  different  compartments  of  the  building,  called  the  1st,  2d,  and  3d  graduation. 
A  deposite  of  gypsum  incrusts  the  twigs,  which  requires  them  to  be  renewed  at  the  end 
of  a  certain  time.  Figs.  1230  A  1231  represent  the  graduation-house  of  the  salt-works 
ftt  Durrenberg.    o,  a,  a,  are  low  stone  pillars  for  supporting  the  brine  cistern  6,  called 


1230 


1231 


the  sooleschiff.  c,  c  are  the  inner,  d,  d  the  outer,  walls  of  thorns  ;  the  first  have  per- 
pendicular sides,  the  last  sloping.  The  spars  e,  e,  which  support  the  thorns,  are  longer 
than  the  interval  between  two  thorn  walls  from /to  g,^g.  1231,  whereby  they  are  readily 
fastened  by  their  tenons  and  mortises.  The  spars  are  laid  at  a  slope  of  2  inches  in  the 
foot,  as  shown  by  the  line  h,  t.  The  bundles  of  thorns  are  each  l\  foot  thick,  from  5  to 
7  feet  long,  and  are  piled  up  in  the  following  way :  —  Guide-bars  are  first  placed  in  the 
line  fe,  /,  to  define  the  outer  surface  of  the  thorn  wall ;  the  undermost  spars  m,  n,  arc 
fastened  upon  them ;  and  the  thorns  are  evenly  spread,  after  the  willow-withs  of  the 
bundles  have  been  cut.  Over  the  top  of  the  thorn  walls  arc  laid,  through  the  whole  length 
of  the  graduation-house,  the  brine  spouts  o,  o,  which  are  secured  to  the  upper  beams ;  and 
at  both  sides  of  these  spouts  are  the  drop-spouts  p,  p,  for  discharging  the  brine  by  the 
spigots  »,  *,  as  shown  upon  a  larger  scale  in^g.  123'/-.  The  drop-spouts  are  6  feet  long, 
have  on  each  side  small  notches,  5  inches  apart,  and  are  each  supplied  by  a  spigot. 
The  space  above  the  ridge  of  the  graduation-house  is  covered  with  boards,  supported  at 
their  ends  by  binding-beams  q.  r,  r,  show  the  tenons  of  the  thorn-spars.  Over  the  soole- 
schiff 6,  inclined  planes  of  boards  are  laid  for  conducting  downwards  the  innumerable 
showers.  The  brine,  which  contains  at  first  7*692  per  cent,  of  salt,  indicates,  after  the 
first  shower,  11*473  ;  after  the  second,  16*108 ;  and  after  the  third,  22.  The  brine,  thus 
concentrated  to  such  a  degree  as  to  be  fit  for  boiling,  is  kept  in  great  reservoirs,  of  which 
the  eight  at  Salza,  near  Schonebeck,  have  a  capacity  of  2,421,720  cubic  feet,  and  are  fi- 
nished with  pipes  leading  to  the  sheet-iron  salt-pans.  The  capacity  of  these  is  very  dif- 
ferent at  different  works.  At  Schonebeck  there  are  22,  the  smallest  having  a  square 
surface  of  400  feet,  the  largest  of  1250,  and  are  enclosed  within  walls,  to  prevent  theii 
being  affected  by  the  cold  external  air.  They  are  covered  with  a  funnel-formed  or  pyra- 
midal trunk  of  deals,  ending  in  a  square  chimney,  to  carry  off  the  steam. 

Figs.  1233,  34,  35,   represent  the  construction  of  a  salt-pan,  its  furnace,  and  the 
■alt  store-room  of  the  works  at  Durrenberg;  /g.  1235 being  the  ground  plan, yig.  1324 


(      '  (. 


i  w 


580 


SALT,  SEA. 


1283 


the  longitudinal  section,  and  ^g.  1233  the  transverse  section,     a  is  the  fire-erate  which 
slopes  upwards  to  the  back  part,  and  is  31J  inches  distant  from  the  ^ttom^o7  the  pin 
The  ratio  of  the  surface  of  the  grate  to  that  of  the  bottom  of  the  pa^  is  as  1  to  59^^5  * 

brfck:  sm^othl^^^^^^^^^^        '''  ^'-P'V^  '  ''•  ''''     '^^^  ^^^  under  re;ins  law  w'h 
bricks,  smoothly  plastered  over,  from  6  to  c,  m  Jig.  1234.  Upon  this  bed  the  pillars  d  d 
&c.,  are  bu.lt  m  a  radiated  direction,  being  6  inches  broad  at  the  bottom,  and  taperinl^'  to 
H  inch  at  top.    The  pan  is  so  laid  that  its  bottom  has  a  fall  towards  the  Sfe  of 

2|  inches;  see  «, /,  ^g.  1234.  The  fire 
diftuses  Itself  in  all  directions  under  the 
pan,  proceeds  thence  through  several 
holes  g,  g,  g,  into  flues  A,  A,  A,  which  run 
round  three  sides  of  the  pan ;  the  burnt 
air  then  passes  through  i,  ^g.  1 235,  uiv- 
der  other  pans,  from  which  it  is  collected 
in  the  chimneys  fc,  fc,  to  be  conducted  into 
the    drying-room.     At    /,    /,    there    is    « 

A  L'!!.'^"u"'  "^  ""*  '.'''"''  *""  '""'^  "  B™''''"'  ascent  above  the  level  of  the  fire-orate 
«g«r<.  ll'''rTertai„"',^^^^^^^^^   T  "'""f' '°  '""^  "«  ""  smoke.Xhly  chance  to 

ttfaVhpU  (L  firiiaf/iJ^^^^^       ''^''!.'"^r'!  "'P^^'"''"  "Pon  each  side  of 
"•«  asa  pit  (see  figs.  1234  &  1235),  into  which  cold  air  is  admitted  by  the  flue  «,  r 


II 

1 

" TV 

^^ 

Ik 

^ 

^ 

II  0* 

/ 

Jk. 

SiliS 

\\aa      , 

I 

1"^      1 

— M — : 

^ 

''T^ 

IL 

J^ 

Z 

.'^ 

II- 

^ 

iV 

^ 

r-  1 

1235 


Tr^n't^^yT'^'''^  ^'^*^x'  ^*  ^'  conducted  through  iron  pipes  ,,  and  thence  escanes  at  L 

which  the  pan  UsnppuJd^ffiual^  brine'     ""*''  ""**•    "'  "'  '"'"'  *«  P'P"  ''^ 

DacriptimoftkeSteam4ruvk,mfig.nZi 

thiba'lrl^fu^oZ&nV/'l^ari  'rare-stl C^'  Z""  T!"'"'  """  '»  """^  "^ 
upon  the  bearers  d  d      Af\  7 «  J;-«        j  ^^    ,     *    ^^®  PiHars  c,  c,  are  sustained 

for  fixing  dowrthe  L  A  J'/'      kT  r^'^T'"^^'  S^'^^^^^  "  '"^de  in  the  beams, 
lor  nxmg  aown  ine  lour  boards  which  form  the  bottom  of  the  stpam  wnv     Tn  #*..•: 


SALT,  SEA. 


581 


two  other  rows  of  boards  are  hooked  on  so  as  to  cover  the  pan,  as  shown  at  h 
Whenever  the  salt  is  sufficiently  drained,  the  upper  shelves  are  placed  in  a  horizontal 

position ;  the  salt  is  put  into  small  baskets, 
and  carried  into  the  stove-room,  t,  j^,  is 
the  steam-trunk ;  l,  m,  is  a  tunnel  for  car- 
rying  off  the  steam  from  the  middle  of  the 
pan,  when  this  is  uncovered  by  lifting  the 
boards. 

In  proportion  as  the  brine  becomes  con- 
centrated by  evaporation,  more  is  added 
from  the  settling  reservoir  of  the  gradu- 
ation-house, till  finally  small  crystals  ap- 
pear on  the  surface.  No  more  weak  brine 
is  now  added,  but  the  charge  is  worked 
off,  care  being  taken  to  remove  the  scum 
as  it  appears.  In  some  places  the  first 
pan  is  called  a  schlot-plan,  in  which  the 
concentration  is  carried  only  so  far  as  to 
cause  the  deposition  of  the  sludge,  from 
which  the  saline  solution  is  run  into  an- 
other pan,  and  gently  evaporated,  to  pro- 
duce the  precipitation  of  the  fine  salt. 
This  salt  should  be  continually  raked  to- 
wards the  cooler  and  more  elevated  sides 
of  the  pan,  and  then  lifted  out  with  cullender-shovels  into  large  conical  baskets,  arranged 
in  wooden  frames  round  the  border  of  the  pan,  so  that  the  drainage  may  flow  back  into 
the  boiling  liquor.  The  drained  salt  is  transferred  to  the  hurdles  or  baskets  in  the  stove- 
room,  which  ought  to  be  kept  at  a  temperature  of  from  120°  to  130°  Fahr.  The  salt  is 
then  stowed  away  in  the  warehouse. 

The  graduation  range  should  be  divided  lengthwise  into  several  sections ;  the  first 
to  receive  the  water  of  the  spring,  the  lake,  or  the  sea ;  the  second,  the  water  from  the 
first  shower-receiver ;  the  third,  the  water  from  the  second  receiver;  and  soon.  The 
pumps  are  usually  placed  in  the  middle  of  the  building,  and  lift  the  brine  from  the  several 
receivers  below  into  the  alternate  elevated  cisterns.  The  square  wooden  spouts  of  distri- 
bution may  be  conveniently  furnished  with  a  slide-board,  attached  to  each  of  their  sides, 
to  serve  as  a  general  valve  for  opening  or  shutting  many  trickling  orifices  at  once.  The 
rate  of  evaporation  at  Moutiers  is  exhibited  by  the  following  table : — 


Number  of  Showers. 


1  and  2 

3,  4, 5,  6,  7,  8,  and  9    - 

10  -  -        - 


Total  Surface  of  the  Fagfots. 


5158  square  feet 
2720 
550 


Specific  Gravity 
of  the  Brine. 


Water 

evaporated. 


1-010 
1-023 
1-072 
1-140 


0-000 
0-540 
0-333 
0-062 


Total  evaporation 
Water  remaining  in  the  brine  at  the  density  of  1-140 

Water  assigned  at  the  densitv  of  1-0 10 


0-935 
1-065 


1000 


From  the  above  table  it  appears  that  no  less  than  10  falls  of  the  brine  have  been 
required  to  bring  the  water  from  the  specific  gravity  1-010  to  1-140,  or  18°  Baume.  The 
t^aporation  is  found  to  proceed  at  nearly  the  same  rate  with  the  weaker  water,  and  with 
the  stronger,  within  the  above  limits.  When  it  arrives  at  a  density  of  from  1*140  to  1-16, 
it  is  run  off  into  the  settling  cisterns.  M.  Berthier  calculates,  that  upon  an  average,  in 
ordinary  weather,  at  Moutiers,  60  kilogrammes  of  water  (13  gallons,  imp.)  are  evaporated 
from  the  fagots,  in  the  course  of  24  hours,  for  every  square  foot  of  their  surface.  Without 
the  aid  of  currents  of  air  artificially  warmed,  such  an  amount  of  evaporation  could  not  be 
reckoned  upon  in  this  country.  In  the  schlotiing,  or  throwing  down  of  the  sediment,  a 
little  bullock's  blood,  previously  beaten  up  with  some  cold  brine,  promotes  the  clarifica- 
tion. When  the  brine  acquires,  by  brisk  ebullition,  the  density  of  1-200,  it  should  be  run 
off  from  the  preparation,  to  the  finishing  or  salting  pans. 

The  mother-water  contains  a  great  deal  of  chloride  of  magnesium,  along  with  chloride 
of  sodium,  and  sulphate  of  magnesia.  Since  the  last  two  salts  mutually  decompose 
each  other  at  a  low  temperature,  and  are  transformed  into  sulphate  of  soda,  which 
trvstallizes,  and  muriate  of  magnesia,  which  remains  dissolved,  the  mother-water  witk 


582 


SAND. 


SANDAL  WOOD. 


583 


Ihis  view  may  be  exposed  in  tanks  to  the  frost  durine  winter  whpn  it  nffVirri.  th^^  «.- 
cessive  crystamne  deposites,  the  last  being  sulphate  of  s^SlrneLly  pire  '^"^  *""• 

The  chloride  of  magTiesium,  or  bittern,  not  only  deteriorates  the  salt*  very  much  but 
occasions  a  considerable  loss  of  weight.     It  may,  however,  be  most  adUntYge^usly  eot 
nd  of  and  converted  into  chloride  of  sodium,  by  the  following  simple  expedfenr-Le 
quick  mie  be  introduced  m  equivalent  quantity  to  the  magnesia  present  and  i^wilpre 
cipitale  this  earth,  and  form  chloride  of  calcium,  which  will  immediately  reac    Zon  thi 
sulphate  of  soda  in  the  mother-water,  with  the  production  of  sulphate  of  limeandrhlnrid! 
of  sodium.    The  former  being  sparingly  soluble,  is  easily  separated     iTme  Ireover 
rhwTnf'  ^'r'"^  -^^  '^^^"5"  of  magnesium,  but  with  the  effect  of  merelTsubst  tutine 
fn  S!       ^^^"7"\^"  't«  ^^^ad-     B»t  in  general  there  is  abundance  of  sulphaie  of  S 
in  brine  springs  to  decompose  the  chloride  of  calcium.    A  still  belter  way  of  proce^^S 
with  sea-water,  would  be  to  add  to  it,  in  Ihe  settling  tank,  the  quantity ^?Ueequh^en? 
l^T^tTT'-'^^^'^^?/'*  ^^^^^'^'^  ^^P°^'t«  °^  this  earth  would  be  obtained,  anhesami 

{^^Xva»^^^^  '^  ^"^^^^"^-  "'^^^^  ^'"^  p^"^^^  '"^y  ^  ^^^'y  -"eS 

In  suinmer,  the  saturated  boiling  brine  is  crjstallized  by  passing  it  over  verfcal  ronP«  • 

Set7..'m^"'*^f^'^^'Tx.'"^*'-^^  (110,000  yards)  are  mounted  in  a"  aTaVtmer'i 

S     i-  J^??-^^^':^-     ^*^^"  *^^  ««'t  ^^^  ^^'^^^  a  crust  upon  the  ropes  aW  2* 

nches  thick,  It  IS  broken  off,  allowed  to  fall  upon  the  clean  floor  of  the  aXtUnt  and 

then  gathered  up.     The  salting  of  a  charge,  which  would  lake  5  or  6  days  in  the  nan^s 

T^:^i^ei:^^sja^^     '^' '''  -^^— -  -  --  abunrt.%reri 

The  boilers  constructed  at  Rosenheim,  in  Bavaria,  evaporate  3^  T)oiind«c  nf  «rnfon  a>. 
every  pound  of  wood  burned  ;  which  is  rWoned  a  fUraWe   esuU  ^"1   o^  on 
described  under  Evaporation,  would  throw  off  much  more.  °^ 

«rthi  r  J*"^-  ^^^^"^'"^  and  principal  brine  springs  are  in  Cheshire  ;  and  the  chief  part 
ofthe  Cheshire  salt,  both  fossil  and  manufactured,  is  sent  by  the  river  Weaver  to  Liver 
?^1^^J;  •"^"  proportion  of  it  being  conveyed  elsewhere,  by  canal  or  llnd  cardaeT 
JnH  •    w      '"f  «P"»?V"  Staffordshire,  from  which  Hull  is  furnished  with  whfte  sa!t  * 
jnd  m  Worcestershire,  from  which  Gloucester  is  supplied.     If  to  the  7uantiTv  .hinnil 
by  the  Weaver,  100,000  tons  of  white  salt  are  ad.led  annually  for  nternrcl' utptbl 
and  exports  exclusive  of  Liverpool,  the  total  manufacture  will  be  approached  verv  near 
ly ;  but  as  there  IS  now  no  check  from  the  excise,  it  is  impossible  to  Leer  tain  heLX 
il't'fi":'''^  '■  '™^V,  '^"""'^^'^^  ^'  «°°^^  «^  the  Cheshire  manufactories,  to  Jtre^^ti^ 
l«nH  "*    '  T^  ''  principally  exported  ;    some  to  Ireland,  but  chiefly  to  Befeum  and  Hoi 
land.«*      The   average  quantity  of  rock  salt  sent  annually  down  the  rive"  Weaver 
^^TI^^u'"^'  ?  Cheshire,  between  the  years  1803  and  1834  inclusive  was  86  000  ^Z 

tt  C'lSis'Vhe'L""''"^  '^^"^^  '''/'I'-  ^"  *'^  y^^'  ''''>  an7tl^l:L't?7^Vo^^^^^ 
flJff  r  T  ^.  ^^-^'^^^  quantity  of  white  salt  sent  annually  down  the  Weaver 

from  the  manufactories  m  Cheshire  during  the  same  period  was  221  q^i     Vh!.  ^^*7  ' 
being  383,669,  in  the  year  1832,  and  the  least  being  12'o,486;  I'the  '"^ar 'iLl  ''  ''''''''' 
M.  Clement-Desormes,  engineer  and  chief  adimnaire  of  the  great  salt-works  of  Dienre 

S>n  onn?'  '"^''"'  "'^  '^l'  ^^'  ^"'^^"^^  consumption  of  that  kingdom  is  rl'ier  l^eThaS 
200,000  tons  per  annum,  being  at  the  rate  of  6I  kilojrrammes  for  each  individual  of^ 
population  estimated  at  32,000,000.    As  the  retail  price  of  salt  in  FranceTs  10  soi  n- 
kilogramme  (Of  2i  lbs.  avoird.),  while  in  this  counti^  it  is  not  more  fhanTs^us  H  pennv^ 
Its  consumption  per  head  will  be  much  greater  with  us ;    and,  takin/i^o  accounT  tl^' 
immense  quantity  of  salted  provisions  that   are  used,  i    may  be  reckoned  at  22  Ihl 
whence  our  internal  consumption  will   be  240,000  tons,  instU  of  mOOO  as  quo^^^ 
above,  from  the  tables  published  by  the  Board  of  Trade  i"",""",  as  quoted 

In  J836,  9,622,427  bushels,  of  56  lbs.  z=  240,560  tons  of  salt,  value   173  923/    wer^ 
exported  from  the  United  Kingdom,  of  which  1,350,849  bushels  wentrKusLa  Ys^^  ORR 
to  Belgium;  314,132  to   the  Western  coast  of  Africa  •    1293  560  to  tL  Br  I,  if^^^^ 
American  colonies;    2,870,808  to  the  fnited  StatesTf  Ame'Lf  53  299  t^  Ne^ 
Wales,  Van  Diemen's  Land,  and  other  Australian  settlements     58  735  to  thpR^rK 
West  Indies  ;  and  90,655  to  Guernsey,  Jersey,  Alderney  a™d  M^n     '  m.  Zh^L  Irlu 
^^r;?JM?^^  ^^^«  15,819,664  bushels;  in  1851    18  ^5  eQsSiels.  ^  *^^ 

obEL^Llt'n^L^hT"/^'^^-  ^'-  ,^--andrand'Mr.TFell  have  lately 
8U  8  of  a  v?rt  ca  cvliin! '^"^  P^'^^"'  ^^'')  f  ""'^  *«  ^^''^  ^^"-  ^he  apparatus  con- 
WK  ♦i.  „I  K  1  ^  .'^^^^*''',"^'?f^"®^  ^^  horizontal  partitions  communicating  each 
with  the  one  below  it  and  each  with  a  pipe  leading  to  a  condenser.  A  smce  isTeft 
between  the  sides  of  the  cylinder  and  the  partitions,  to  allow  of  steam  citculS  freely 

Khe  apparatus  from  the  top,  and  circulates  over  the  partitions,  and  the  aqueous  vapour 
•  Tables  of  the  Keveaue,  Population,  Commerce,  Ac.,  for  1835,  p.  122. 


arising  from  it  passes  oflF  to  the  condenser,  and  on  its  way  becomes  mixed  with  at- 
mospheric air,  introduced  through  a  suitable  pipe,  and  issues  from  the  condenser  in  an 
aerated  state,  while  the  water  arising  from  the  condensation  of  the  steam  admitted  into 
the  cylinder  is  discharged  therefrom  without  being  aerated.  The  apparatus  may  bo 
constructed  of  any  suitable  materials,  but  the  patentees  recommend  the  use  of  zinked  or 
galvanized  iron. 

SAND  (Eng.  and  Genn. ;  Sable,  Fr.) ;  is  the  name  given  to  any  mineral  substance  in 
a  hard  granular  or  pulverulent  form,  whether  strewed  upon  the  surface  of  the  ground, 
found  in  strata  at  a  certain  depth,  forming  the  beds  of  rivers,  or  the  shores  of  the  sea 
The  siliceous  sands  seem  to  be  either  original  crystalline  formations,  like  the  sand  of 
Neuilly,  in  6-sided  prisms,  terminated  by  two  6 -sided  pyramids,  or  the  debris  of  granitic, 
schistose,  quartzose,  or  other  primitive  crystalline  rocks,  and  are  abundantly  distributed 
over  the  globe;  as  in  the  immense  plains  known  under  the  names  of  downs,  deserts, 
steppes,  landes,  Ac,  which,  in  Africa,  Asia,  Europe,  and  America,  are  entirely  covered  with 
loose  sterile  sand.  Valuable  metallic  ores,  those  of  gold,  platinum,  tin,  copper,  iron, 
titanium,  often  occur  in  the  form  of  sand,  or  mixed  with  that  earthy  substance.  Pure 
siliceous  sands  are  very  valuable  for  the  manufacture  of  glass,  for  making  mortars, 
filters,  ameliorating  dense  clay  soils,  and  many  other  purposes.  For  moulder's  sand, 
see  Founding.     Lynn  and  Ryegate  furnish  our  purest  siliceous  sand. 

SAND  FOR  GLASS  MAKING.  The  Great  Exhibition  was  well  furnished 
with  specimens  of  the  finer  kinds  of  sand ;  some  of  which,  as  those  from  the  l3l« 
of  Wight,  and  the  neighbourhood  of  Lynn,  were  remarkably  white  and  beautiful  By 
fiir  the  finest  sample  of  sand  ever  seen  in  this  country  was,  however,  in  the  American 
department  of  the  Crystal  Palace,  and  did  not  fail  to  attract  the  notice  of  those  interested 
in  such  matters.  This  sand  was  contained  in  two  or  three  barrels  in  the  southern  side  of 
the  building,  and  seems  totally  free  from  iron  and  every  other  source  of  contamination. 
It  was  positiviely  as  white  as  snow,  and  so  far  as  the  making  of  glass  is  concerned,  may 
rival  or  supersede  the  best  flint,  even  if  the  high  price  of  this  latter  article  did  not  form  an 
insuperable  obstacle  to  its  employment.  It  was  from  T.  Gray  &  Co.,  Boston,  Massachusetts ; 
but  its  geological  locality  was  not  stated.  The  principal  exhibitors  of  sand  for  the  ma- 
nufacture of  glass  were.  Sir  T.  Mary  on  Wilson,  of  Charlton  ;  J.  Rock,  jun.,  of  Hastings; 
Whittaker  <fe  Winksworth,  Derbyshire;  J.  Claston,  of  Alum  Bay,  and  J.  Squire,  of 
Yarmouth,  Isle  of  Wight;  S.  Relfe,  of  Reigate,  and  G.  Morrison  of  the  same  town, 
agent  to  Earl  Somers ;  with  J.  Long,  of  Limerick ;  J.  Deering,  of  Cork ;  T.  Smedley, 
of  Lardidno ;  and  J.  Lee,  of  Hartwell,  near  Aylesbury.  These  specimens  of  sand  have 
all  more  or  less  of  the  yellow  topaz  hue,  indicating  oxide  of  iron,  and  which  imparts  to 
all  glass  the  green  tinge  so  very  perceptible  in  the  common  window  variety.  To 
remove  this  oxide  of  iron  from  sand,  has  never  yet,  we  believe,  been  attempted  ;  though 
if  we  may  judge  by  the  trouble  taken  to  mollify  its  influence  in  the  manufacture  of  glass, 
an  effectual  process  of  the  kind  would  be  a  lucrative  discovery.  When  sand  contain- 
ing oxide  of  iron  is  mixed  with  a  little  charcoal  and  subjected  at  a  red-heat  to  the  action 
of  chlorine  gas,  the  whole  of  the  iron  is  volatilized  as  chloride  of  iron,  and  the  silica 
remains  pure  as  soon  as  the  excess  of  charcoal  is  burnt  off:  this  experiment  seems  to 
suggest  the  possibility  of  purifying  the  glass  maker's  sand,  by  the  employment  of  the 
waste  muriatic  acid,  now  thrown  away  so  largely  by  our  soda  makers.  Even  at  ordinary 
temperatures,  the  solution  of  oxide  of  iron  by  this  means  might  be  hoped  for;  but  there 
can  be  no  practical  objection  to  the  use  of  a  reasonable  amount  of  heat  for  such  a  pur- 
pose, if  found  necessary. 

SANDAL  or  RED  SAUNDERS  WOOD  {Santal,  Fr. ;  Sandelholzy  Germ.  ),  is  Ibe 
wood  of  the  Pterocarpus  sanicUinuSy  a  tree  which  grows  in  Ceylon,  and  on  the  coast  of 
Coromandel.  The  old  wood  is  preferred  by  dyers.  Its  coloring  matter  is  of  a  resinous 
nature  ;  and  is,  therefore,  quite  soluble  in  alcohol,  essential  oils,  and  alkaline  leys  ;  bat 
sparingly  in  boiling  water,  and  hardly  if  at  all  in  cold  water.  The  coloring  matter 
which  is  obtained  by  evaporating  the  alcoholic  infusion  to  dryness,  has  been  called 
gantaline;  it  is  a  red  resin,  which  is  fusible  at  2l2°  F.  It  may  also  be  obtained  by 
digesting  the  rasped  sandal  wood  in  water  of  ammonia,  and  afterwards  saturating  the 
ammonia  with  an  acid.  The  santatine  falls,  and  the  supernatant  liquor,  which  is  yellow 
by  transmitted,  appears  blue  by  reflected  light.  Its  spirituous  solution  aflbrds  a  fine 
purple  precipitate  with  the  protochloride  of  tin,  and  a  violet  one  with  the  salts  of  lead. 
^^anlaline  is  very  soluble  in  acetic  acid,  and  the  solution  forms  permanent  stains  upon 
llie  skm. 

Sandal  wood  is  used  in  India,  along  with  one  tenth  ofsapan  wood  (the  Casalpinia  sapan 
of  Japan,  Java,  Siam,  Celebes,  and  the  Philippine  isles),  principally  for  dyeing  silk  and 
cotton.  Trommsdorf  dyed  wool,  cotton,  and  linen  a  carmine  hue  by  dipping  them  alter- 
nately in  alkaline  solution  of  the  sandal  wood,  and  in  an  acidulous  balh.  Bancroft  ob» 
tained  a  fast  and  brilliant  reddish-yellow,  by  preparing  wool  with  an  alum  and  tartar  t>ath, 
and  then  passing  it  through  a  boiling  balh  of  sandal  wood  and  sumac    Pelletier  did  noC 


584 


SCAGLIOLA. 


SCARLET  DYE. 


585 


il 


f    in 

1    I* , 


,;fi 


!     '.11 
il 


I 


succeed  in  repeating  this  experiment.    Accordine  to  Toiler  xirnni  cJib  ^«f*««  -  j  r 
mordanted  with  salt  of  tin  and  dipped  in  a  cold'  aLfeSe ff\he^  3^^ 
same  tincture  mixed  with  8  parts  of  boiling  water,  become  of  a    uperb  pon^au-r^^^^^^^^ 
With  alum,  they  took  a  scarlet-red  ;   with  sulphate  of  iron,  a  deep  viokt  C  brotn  r^* 
Unluckily,  ihese  dyes  do  not  stand  exposure  to  li-ht  well.  '        brown-red. 

SANDARACH,  is  a  peculiar  resinous  substance,  the  product  of  the  Thuufi  nrN.^iJnfn 
a  sma  1  tree  of  the  coniferous  family,  which  grows  in  [he  northern  par  s^?  it^ei 
pecially  round  Mount  Atlas.  ^  Airica,  e8- 

The  resin  comes  to  us  in  pale  yellow,  transparent,  brittle,  small  tears  of  a  RnliPrIP«l 
or  cyhndr.cal  shape      It  has  a  faint  aromatic  smell,  does  not'sof.en,  but  bVeLs  Liwe^^^^^ 

^J  ApVt^'  different  resins ;  one  soluble  in  spirit  of  wine,  somewhat  resembl  n"  ;^^^^^^ 
actd(seeluRPENTiNK);  one  not  soluble  in  that  n>enstruum  ;  and  a  third  .olubie  onlv 
in  alcohol  of  90  per  cent  It  is  used  as  pounce-powder  for  strewing  o4r  pa/er  erasur^^^^^ 
as  incense,  and  in  varnishes.  *  ^      ciasuree, 

Tt  fAnt^i^I  k^?k'  'I*  ^Pl"f  ^'^  the  C^salpinia  genus,  to  which  Brazil  wood  belongs 
It  is  so  called  by  the  French,  because  it  conies  to  them  from  Japan,  which  thev  corrS 

Euron'I^r  "'^^^  Z^  '^""'^  '^"^*""  ''•"'  '^'y  ^^"''^  "«^  have  been  used  ardye'sTuff;  Z 
Europe  before  the  beginning  of  the  16th  century.     Yet  the  author  of  the  article  «  Brazil  ^ 
Int       Jy^^«P^^'«' ««d  Mr.  Southey,  in  his  History  of  Brazil,  say  that  ira^tV  wood  is 
aientioned  nearly  one  hundred  years  before  the  discoveries  of  Columbus  and  VaTcode  Garni 
by  Chaucer,  who  died  m  1400 ;  that  it  was  known  many  a?es  before  his  time     and  that' 

I^^::  't  7r'/if  '^'  T^r^^  T^^^^  ^^  ^^^^  country  giWng  the  name  t^the  wood  as 
I  have  stated,  with  BerthoUet  and  other  writers  on  dyeinff.     The  CtBsalmnia,am,nn 

^h".?  IT:'  '^  ^'f  Coromandel  coast,  may  possibly  iLe  been  transponrin^'^S 
other  Malabar  merchandise  to  the  Mediterranean  marts  in  the  middle  aees  but  the  inu 
portation  of  so  lumbering  an  article  in  any  considerable  quanti.v  by  Iharchan,  el^s^ 

dyers  of  Europe  before  the  discovery  of  the  New  World.  ^ 

SARD ;  see  Lapidary. 

SATIN  (Eng.,  Fr.,  and  Germ.),  is  the  name  of  a  silk  stuff,  first  imported  from  Thin. 
which  IS  distinguished  by  its  very  smooth,  polished,  and  glossy'surfac"^  i  Is  wo^e^unon 
a  loom  with  at  least  five-leaved  healds  or  heddles,  and  as  many  corr^spondi^-  tr3« 
These  are  so  mounted  as  to  rise  and  fall  four  at  a  time,  raising  and  depress ii"\liern«^' 
\1  four  yarns  of  the  warp,  across  the  whole  of  which  the  weft  is  thrXn  by  il^e  4uttle' 
80  as  to  produce  a  uniform  smooth  texture,  instead  of  the  checkered  work  resultin^ZS 
intermediate  decussations,  as  in  common  webs.  See  Textile  FABRicr  W%  ?" 
woven  with  the  glossy  or  right  side  undermost,  because  the  four-fifths  of  the*  war,  whkh 
are  alway's  left  there  during  the  action  of  the  healds,  serve  to  support  the  shuTt l^Tn  Tts 
^ce  Were  they  woven  in  the  reverse  way,  the  scanty  fifth  part  of  the  warp  thread  J 
ti  TTT^p'■A^'?r^'^P^°'■^?  ^'  ^°"^^  ^^  ^°«  n^"^h  worn  bv  the  shultle.  ^  *"*' 

&A1  UKAllON,  is  the  term  at  which  any  bodv  has  taken  its  full  dose  or  chemical 

in  their  teeth  very  accurately  by  means  of  a  division  plate ;  this  prevfnts  iSa.  ly  of 
eize,  and  imparts  smoothness  and  uniformity  of  action.  The  krger  sizes  Sfccular 
saws  are  made  m  segments  and  connected  together  by  means  o  dove  au/  A  U^^^^^^ 
are  hardened  and  tempered  in  oil;  their  irregularities  are  removed  by  hammering  o„ 
ci^'ni'  t'^  '^'"^  ^''  '^"^"^"^  ^y  g""^^"^-    ^'^^«  ««veral  forms  of  teefh  do  nTS'the 

SrouLh  tf/r/r'^Y  ''"'^•"''  ^'Pf"^  "P^^  '^'^'^  ^^^  ^'^  *»»«««  b-«t  fitted  ?or 'c^^^t  ' 
^rough  the  particular  sectiun,  quality,  or  hardness  of  the  material  to  be  cut.  The  "  se"" 
of  the  saw  consists  m  inclining  the  teeth  at  the  particular  angle  known  to  be  the  £t 
to   facilitate  the   exit   of  the   sawdust,   and    thereby  allow  the  saw  to    operate  mo'e 

Sous'  ra?e  and'i^w'  .  ^'""SWesented  to  the  saw  red  hot;  the  saw  rotated  at  a  pro3 - 
pous  rate,  and  is  kept  m  cutting  condition,  or  cool,  by  its  lower  edge  bein-  immersed 
^PAPT  TOr^r '''"  '"t"'  '"  diameter  is  cut  throughin  a  few  seconds       °  "^ 

bOALrLlULA,  13  merely  ornamental  plaster-work,  produced  by  applying  a  pap  madt 
of  finely-ground  calcined  gypsum,  mixed  with  a  weak  solution  of  FlanTer^s'  gli^  mx.^rny 
figure  tormed  of  laths  nailed  together,  or  occasionally  upon  brickwork  and  b^  uddin^ka 
surface,  while  soft,  with  splinters  (^cagliole)  of  spar,  m^rbre.granite  bits  of  cotrete^S 
ppsum,  or  v-ems  of  clay,  m  a  semi-fluid  state.  The  substances  employed  to  colour  he 
spots  and  patches  are  the  several  ochres,  boles,  terra  di  Sienna,  chrome  yellow.  <fec  The 
surface  of  the  column  is  turned  smooth  upon  a  lathe,  polished  with  stones  of  dkreo? 


fineness,  and  finished  with  some  plaster-pap,  to  give  it  lustre.  Pillars  and  other  flat  sur- 
faces are  smoothed  by  a  carpenter's  plane,  with  the  chisel  finely  serrated,  and  afterwards 
polished  with  plaster  by  friction.  The  glue  is  the  cause  of  the  gloss,  but  makes  the  sur- 
face apt  to  be  injured  by  moisture,  or  even  damp  air. 

SCARLET  DYE.  {Teinture  en  ecarlaie,  Fr. ;  Scharlachfdrberei,  Germ.)  Scariet  is 
usually  given  at  two  successive  operations.  The  boiler  (see  Jigs.  364,  365,  article  Dye- 
ing) is  made  of  block  tin,  but  its  bottom  is  formed  occasionally  of  copper. 

1.  The  bouillm,  or  the  cohring-lath.—Tor  100  pounds  of  cloth,  put  into  the  water,  when 
it  is  little  more  than  lukewarm,  6  pounds  of  argal,  and  stir  it  well.  When  the  water  be- 
comes too  hot  for  the  hand,  throw  into  it,  with  agitation,  one  pound  of  coChineal  in  fine 
powder.  An  instant  afterwards,  pour  in  5  pounds  of  the  clear  mordant  g  (see  Tin  Mor- 
dants), stir  the  whole  thoroughly  as  soon  as  the  bath  begins  to  boil,  introduce  the  cloth, 
and  wince  it  briskly  for  two  or  three  rotations,  and  then  more  slowly.  At  the  end  of  a 
two-hours'  boil,  the  cloth  is  to  be  taken  out,  allowed  to  become  perfectly  cool,  and  well 
washed  at  the  river,  or  winced  in  a  current  of  pure  water.  (See  an  automatic  plan  of 
washing  described  under  the  article  Rinsing  Machine.) 

2.  The  rougie,  or  finishing  dye. — The  bouillon  bath  is  emptied,  and  replaced  with  water 
for  the  rougie.  When  it  is  on  the  point  of  boiling,  5|  pounds  of  cochineal  in  fine  powder 
are  to  be  thrown  in,  and  mixed  with  care ;  when  the  crust,  which  forms  upon  the  sur- 
face, opens  of  itself  in  several  places,  14  pounds  of  solution  of  tin  (as  above)  are  to  be 
added.  Should  the  liquor  be  likely  to  boil  over  the  edges  of  the  kettle,  it  must  be  refresh- 
ed with  a  little  cold  water.  When  the  bath  has  become  uniform,  the  cloth  is  to  be  put  in, 
taking  care  to  wince  it  briskly  for  two  or  three  turns ;  then  to  boil  it  bodily  for  an  hour, 
IhrusUng  it  under  the  liquor  with  a  rod  whenever  it  rises  to  the  surface.  It  is  lastly  ta- 
ken out,  aired,  washed  at  the  river,  and  dried. 

As  no  person  has  done  more  for  the  improvement  of  the  scarlet  dyes  than  Poerner,  I 
shall  here  give  his  processes  in  detail. 

Bouillon^  or  coloring. — For  every  pound  of  cloth  or  wool,  take  14  drachms  of  cream  of 
tartar.  "When  the  bath  is  boiling,  and  the  tartar  all  dissolved,  pour  in  successively  14 
drachms  of  solution  of  tin  {Mordant  f.  Tin),  and  let  the  whole  boil  together  during  a  few 
minutes.  Now  introduce  the  cloth,  and  boil  it  for  2  hours ;  then  take  it  out,  and  let  it 
drain  and  cool. 

Rougicy  or  dye. — For  every  pound  of  woollen  stuff,  take  2  drachms  of  cream  of  tartar. 
When  the  bath  begins  to  boil,  add  1  ounce  of  cochineal  reduced  to  fine  powder,  stir  the 
mixture  well  with  a  rod  of  willow  or  any  white  wood,  and  let  it  boil  for  a  few  minutes. 
Then  pour  in,  by  successive  portions,  1  ounce  of  solution  of  tin  {Mordant  f),  stirring  con- 
tinually with  the  rod.    Lastly,  dye  as  quickly  as  possible.    The  color  will  be  a  beautiful 

scarlet. 

Secmd  scarlet  process  of  Poerner,  the  bouillon  being  the  same  as  above  given,  and  al- 
ways estimated  for  1  pound  of  cloth  or  wool.  Rougie. — Take  1  ounce  of  cochineal  in  fine 
powder,  and  2  ounces  of  solution  of  tin  without  tartar. 

Third  scarlet  process  of  Poerner ;  the  bouillon  being  as  above.  Rougie  for  a  pound  of 
cloth. — ^Take  two  drachms  of  cream  of  tartar,  one  ounce  of  cochineal,  one  ounce  of  solu- 
tion of  tin,  and  2  ounces  of  sea  salt ;  dye  as  in  process  1.  The  salt  helps  the  dye  to  pendt 
trate  into  the  cloth. 

Tables  of  the  Composition  of  the  Bouiixon  and  Rougie,  by  diflferent  Authors, 

for  100  pounds  of  Cloth  or  Wool. 

Composition  of  the  Bouillon. 


Nnmes  of  the  Authon. 

Starch. 

Cream  of 
Tartar. 

Cochineal. 

Solution  of 
Tin. 

CommoD 
Salt. 

BerthoUet     - 
Hellot 
Scheflfer 
Poerner 

lb.        OZ, 

0        0 
0        0 
9         6 
0        0 

lb.      oz. 

6        0 
12        8 

9        6 
10       15 

lb.      dr. 

8  0 
18  6 
12        4 

0        0 

lb.      oz. 

5        0 
12        8 

9         6 
10       15 

lb.        OX. 
0        0 
0        0 
0        0 
0        0 

M.  Lenormand  states  that  he  has  made  experiments  of  verification  upon  all  the  formu 
lee  of  the  preceding  tables,  and  declares  his  conviction  that  the  finest  tint  may  be  obtained 
by  taking  the  bouillon  of  Schefler,  and  the  rougie  No.  4  of  Poerner.  The  solution  which 
produced' the  most  brilliant  red,  is  that  made  according  to  the  process  of  mordant  b  (Tin.) 
M.  Robiquet  has  given  the  following  prescription  for  making  di  printing  scarlet,  for  well- 
whitened  woollen  cloth. 


586 


It! 


^1 II 


'i  i 


11  i  1 
11 


l;i 


In 


SCHEELE'S  GREEN. 

Composition  of  the  Rougte, 


SCOURING. 


587 


Names  of  the  Authors. 


Starch. 


I     Cream  of 
Tartar. 


BerlhoUet 

Hellot 

Scheffer 

I  Poerner 


i 


lb. 

0 
3 
3 
0 
0 
0 


oz, 

0 

2 

2 

0 

0 

0 


lb. 

0 

0 

3 

1 

0 

1 


Cochineal. 


OZ. 

0 

0 

2 

8 

0 

8 


lb. 

5 

7 

5 

6 

6 

6 


OZ. 

8 
4 

7i 
4 
4 
4 


dotation  of 
Tin. 


lb. 

14 
12 

4 

6 
12 

6 


Common 
Salt. 


OZ. 

«>. 

oc 

0 

0 

0 

8 

0 

0 

11 

0 

0 

4 

0 

0 

8 

0 

0 

4 

12 

8 

he  eight  pints  of  decoction,  thickr.hV„pr„S  ^^h  .^^^^^  "'T  '''« '•««<l''"n..'D,ix 

into  a  paste.    Let  it  cool  down  to  104°  r    ih^^.Z  7  """"J''*  "^  ^'^^h,  and  boil 

of  tin,  and  two  ounces  of  ordinal  ia"t  of  iin  ("ul.e T'  xX"  "'^'"^  '"^'"'""^  «''""''» 

m  sZl""?';^''''  ^--Mturmeri^rshrid  beidde?'"  "  '""''='"'  '«"  '^  -""'«'. 

.pe^fiVtaiZ  /e^' V=  "3?":^^^^^^^^^^^^^  "'"■'^--  <»>»«  of  "i'ric  acid,  of 

The  tin  is  to  bi  divided  in  o  eight lrtion"and?ne  oTr"'"' '. '?"'  """«'  "'  f^™'"  «'»• 
ture  every  quarter  of  an  hour.  '        ™'  ""^  ""^  '"  "> "«  P"'  '"lo  Ihe  acid  mix- 

mafkabfrnner?"""'  "'  '"'«^^'  '"""*  '>  ^  -"• '»  ''e-tify  scarlet  cloth  in  .  re 

»«tra^dTE?s::,vi:;rtinTbua  si'statt-su'^  rr-  »^  -'->"™  ""o 

ayers  to  adopt  his  plans.  l'„  fac^  the  prZr  bZ  s  n  mv"^-''"' '"  Pr^""*!"?  scarlet- 
oxyde  and  pcroxyde  of  tin :  and  this  canimi  h.^M»  • '  a  u^  "P'.""'".  »  ""Jtlure  of  Ihe  prot- 
murio-sulphuric  acid.  He  also  p  escr  brf  ?he  e^Hl^^  ""7  T"  "'"  ■"''»'  '>"^"« 
change  the  natural  crimson  of  the  cochneal  into  scar  i^th-^^^^^  ''""■'"'■™  ''"'"'  '" 
ty  of  this  expensive  dye-stuff.    See  Lac  Dve  ^  econoroizing  the  quanti- 

ac,d  to  2  pounds  of  carbonate  of  potaSrdTsid  i^i^fo^'^''"!^"^  ^^  «""<=««  of  arsrnious 
disso  ve  2  pounds  of  crystallized  sulphate  o?c^^^^^^^^^  ^'^'"^  ^^^^^^  ^  «ext, 

solution,  then  pour  the  first  pro-ressivelv  into  fhp  .^LnH  P^^^^^ ''^  water ;  filter  each 
grass-green  precipitate.  This  beinrthiwn  unonTfiu' ^V??"  ^l^'  Produces  a  rich 
warm  water,  will  afford  1  pound  6  ounceronhisTautif^i^^nF;  i  ^"?  edulcorated  with 
oi  copper  28-51,  and  of  arsenious  ac"d  7l'46      T^fs  '^^^^^^^^^^  It  consists  of,  oxyde 

SCHWfX^'tILT^^^^^  See  CALico.p;rNTmc.^"'" ''  ^PPHed  by  an  analogous 

procedin,S''™dS^din^8HV™^^^  ^^-   '^^ 

and  remained  for  many  years  a  profitable  .errPt  in  iK  -if    ?^  ^.","'^'''  *^  Schweinfurth, 

gs  composition  known;  in  182?,  rhafbLn  Tncrnr.nnrJt"'''-  ^'  ^'^^'^  ^^^'"?  "^^de 
Braconnot  puk/ished,  about  the  same  time  another  To 'L'"r^  ^"'^'  ?""^  color-works, 
pigment.  Us  preparation  is  very  simple  buHtsforrTnTon-  '"^""^"^'"ring  the  same 
teresting  circumstances.  On  mixin^^ukl  narts  of  «^^  i?  is  accompanied  with  some  in- 
each  in  a  boiling  concentrated  solution  a'buk/oli^^^^  "''''''  ""^  ^""^^"'^"^  ^<^i^> 

produced;  while  much  acetic  acid  is  itfilThpn^^^^^^  is  immediately 

a  compound  of  arsenious  acid  and  oxyde  of  cooner  n  «  n  *^•'  °^'^'"^'^'  ^^^'^'^  ^o  bj 
composed  by  sulphuric  acid,  no  aceUc  o^r  is  exhaied  Nr."^/"-''"'' '  f'"<^e  when  de- 
in?,  by  exposure  to  air,  or  b^  being  heatS  in  water  but  f^tt  K  "i"'.  -^'^^  ^^  ^'7- 
liquor  from  which  it  was  precipitated  it  soon  rh^nlii  •»  ,'  ^  ^^  '*°*^^*^  *"  ^he  acidulous 
gation,  and  forms  a  new  denSin  \ip X^^^^  its  color,  as  well  as  its  state  of  a^^re- 
As  fine  a  color  is  produced  'bTrbumbndu'n'fivlrsrr  ^^^^"  ^ow^er. 

end  of  several  hours  by  mixin<r  the  two  boi?in"%nlnr  ^'"n^'»  ^'  ^'  '^^^^'"ed  at  the 

together.     I„  the  latter  case,  Ihe  preZSwhth"'i'  ?^  ""r"'"-  '^^  "^^^^^  to  cool 
denser  by  decrees;  it  next  bitrays^greTn  s^^^^^^^^^  '  "1  "''^'  °'  '''■'''  ^^^«'"^» 

grows  altoorether  of  a  crystalline  constitution  am^^^  increase,  till  the  mass 

by  ebullition.  '  ^  constitution,  and  of  a  still  more  beautiful  tint  than  if  formed 

laS;W,^^h:rel^;^^^^^^^  the  predpitat. 

ftner.      The  best  mode  of  procedure    i.  l  lu   ?'  I'^V,^^^^*'^^  **'*  "'^^'^^^  it  much 
.»U.  of  cold  water,  and  to  ^^^'^^^.^^^L^  ^iX^^r:;^^^  ^^ 


rent  the  formation  of  any  such  pellicle  on  the  surface  as  might,  by  falling  to  the  bottom, 
excite  premature  crystallization.  Thus  the  reaction  continues  during  two  or  three 
days  with  the  happiest  effect  The  difference  of  tint  produced  by  these  variations 
arises  merely  from  the  different  sizes  of  the  crystalline  particles ;  for  when  the  several 
powders  are  levigated  upon  a  porphyry  slab  to  the  same  degree,  they  have  the  same 
shade.  Schweinfurth  green,  according  to  M.  Ehrmann's  researches,  in  the  81st  Bulletin 
de  la  Societee  Industrielle  Mulhausen,  consist  of,  oxide  of  copper  31-666,  arsenious  acid 
58-699,  acetic  acid  10-294.  Kastoer  has  given  the  following  prescription  for  making 
this  pigment ;— For  8  parts  of  arsenious  acid,  take  from  9  to  10  of  verdigris ;  diffuse  the 
latter  through  water  at  120°  F.,  and  pass  the  pap  through  a  sieve ;  then  mix  it  with 
the  arsenical  solution,  and  set  the  mixture  aside,  till  the  reaction  of  the  ingredients  shall 
produce  the  wished-for  shade  of  colour.  If  a  yellowish  tint  be  desired,  more  arsenic 
must  be  used.  By  digesting  Scheel's  green  in  acetic  acid,  a  variety  of  Schweinfurth 
green  may  be  obtained. 

Both  of  the  above  colours  are  rank  poisons.  The  first  was  detected  a  few  years  a^o, 
as  the  colouring-matter  of  some  Parisian  bonbons,  by  the  cojuteil  de  salubrite;  since  which 
the  confectioners  were  prohibited  from  using  it,  by  the  French  government 

Schvoeinfarth  Oreen  ;  preparation  of.  60  lbs  of  sulphate  of  copper  and  10  lbs.  of  lime 
are  dissolved  in  20  gallons  of  good  vinegar,  and  a  boiling-hot  solution  of  50  lbs.  white 
arsenic  conveyed  as  quickly  as  possible  into  the  solution;  it  is  stirred  several  times,  and 
then  allowed  to  subside.  The  supernatant  liquor  is  employed  the  next  time  for  dis- 
solving the  arsenic. 

The  pigment  is  cooled  on  the  filter,  dried,  pounded,  sifted,  and  again  rubbed  up  with 

a  little  muriatic  acid.  ^, .         ,      .  ,  »  j-  j  v 

SCOURING,  or  renovating  articles  of  dress.  This  art  has  been  much  more  studied  by 
Frenchmen,  who  wear  the  same  coats  for  two  or  thr«»  'ears,  than  by  Englishmen,  who 
generally  cast  them  off  af\er  so  many  months.  The  workmen  who  remove  greasy  stains 
from  dress,  are  called,  in  France,  ieiniuriers-degraisseurs,  because  they  are  ofien  obliged 
to  combine  dyeins  with  scourine  operations.  The  art  of  cleansing  clothes  being  founded 
upon  the  knowledge  of  solvents,  the  practitioner  of  it  should,  as  we  shall  presently  illus- 
trate by  examples,  be  acquainted  with  the  laws  of  chemical  affinity. 

Among  the  spots  which  alter  the  colors  fixed  upon  stuffs,  some  are  caused  by  a  substance 
which  may  be  described  as  simple,  in  common  language ;  and  others  by  a  substance  which 
results  from  the  combination  of  two  or  more  bodies,  that  may  act  separately  or  together 
upon  the  stuff,  and  which  may  therefore  be  called  compound. 

Simple  «/at7J«.— Oils  and  fats  are  the  substances  which  form  the  greater  part  of  simple 
stains.  They  give  a  deep  shade  to  the  ground  of  the  cloth  ;  they  continue  to  spread  for 
several  days ;  they  attract  the  dust,  and  retain  it  so  strongly,  that  it  is  not  removeable  by  the 
brush ;  and  they  eventually  render  the  stain  lighter  colored  upon  a  dark  ground,  and  of  a  dis- 
agreeable gray  tint  upon  a  pale  or  light  ground. 

The  general  principle  of  cleansing  all  spots,  consists  in  applying  to  them  a  substance 
which  shall  have  a  stronger  affinity  for  the  matter  composing  them,  than  this  has  for  the 
cloth,  and  which  shall  render  them  soluble  in  some  liquid  menstruum,  such  as  water, 
spirits,  naptha,  oil  of  turpentine,  &c.     See  Bleaching. 

Alkalis  would  seem  to  be  proper  in  this  point  of  view,  as  they  are  the  most  powerful 
solvents  of  grease;   but  they  act  too  strongly  upon  silk  and  wool,  as  well  as  change  too 
powerfully  the  colors  of  dyed  stuffs,  to  be  safely  applicable  in  rernovi.;?  stains.    The  best 
substances  for  this  purpose  are— 1.  Soap.      2.    Chalk,  fuller's  earth,  soap-stone   or 
steatite  (called  in  this  country  French  chalk).     These  should  be  merely  diffused  through 
a  little  water  into  a  thin  paste,  spread  upon  the  stain,  and  allowed  to  dry.     The  spot  re- 
quires now  to  be  merely  brushed.     3.  Ox-gall  and  yolk  of  egg  have  the  property  of  dis- 
solving fatty  bodies  without  affecting  perceptibly  the  texture  or  colors  of  cloth,  and  may 
therefore  be  employed  with  advantaffe.    The  ox-gall  should  be  purified,  to  prevent  iU 
greenish  tint  from  degrading  the  brilliancy  of  dyed  stuff's,  or  the  purity  of  whites.     Thus 
prepared  (see  Gall),  it  is  the  most  precious  of  all  substances  known  for  removing  ihese 
kinds  -jf  stains.    4.  The  volatile  oil  of  turpentine  will  lake  out  only  recent  stains ;  for 
which  purpose  it  ought  to  be  previously  purified  by  distillation  over  quicklime,     Wax, 
rosin,  turpentine,  pitch,  and  all  resinous  bodies  in  general,  form  stains  of  greater  or  less 
adhesion,  which  may  be  dissolved  out  by  pure  alcohol.     The  juices  of  fruits,  and  the  col- 
ored juices  of  all  vegetables  in  general,  deposite  upon  clothes  marks  in  their  peculiar 
hues.     Stains  of  wine,  mulberries,  black  currants,  morellos,  liquors,  and  weld,  yield  only 
to  soaping  with  the  hand,  followed  by  fumigation  with  sulphurous  acid;  but  the  latter 
process  is  inadmissible  with  certain  Colored  stuffs.     Iron  mould  or  rust  stains  may  he 
taken  out  almost  instantaneously  with  a  strong  solution  of  oxalic  acid.    If  the  stain  is 
recent,  cream  of  tartar  will  remove  it.  j  t     •    u      v 

Compound  spots.  —  That  mixture  of  rust  of  iron  and  grease  called  cambouts  by  the 


538 


SCREW-MAKING. 


SEAL  FISHERY. 


589 


''!l 


renu^val  Of  the  grease,  and  theLf  he  i^sfb^^^^^^^^      *^°  1^'*^^*  operations;  first,  the 
Mud.  especially  that  of  cities  is  IcnZt.  ^i    f  ^eans  above  indicated. 

matter  in  S  state'^of  black  ox  ?a     wrsE":!"^^^^^^!*^  '5^"^'  «-»  -'  ferruginous 
Boapingr  will  take  away  the  vegetobleticL  ticfr.n'^fi''''-^^""^^^  '^  necessary  with 
cream  of  tartar,  which  itself  mi^howive'  be  wtn^t^^         ^'^[^  «\^3f  be  removed  with 
cen  ,  may  be  taken  out  by  washii..  first  with  nnri  J?        ''"^*     ^""^  stains,  when  re- 
laslly  with  lemon  juice;  but  if  o  ^Ihev  m^ast  h'TrlJr^r^^  ^^^^  soapy  water,  and 

sioned  by  smoke,  or  by  'sauces  browned  [n  a  t^^^^^  "^''^  ^-^^^'^  ^cid.     Stains  icca- 

niLxture  of  pitch,  black  oxyde  of  i^n  em"  ^eurt^^^^^^  ""7  ^^  '"^^^^^^  ^^  '^""^^^l  of  a 
in  pyioligneous  acid.     In  \his  cas^sev^  rea4' t.^  m ^  '"^^  matters  dissolved 

«ams.  Water  and  soap  dissolve  pcrfec  ly  weH  the^'l  be  employed  to  remove  the 
pyrohgneous  acid,  and  even  the  empy  ^11^^^^^  matters,  the  salts,  the 

turpentine  will  remove  the  rest  of  the  oTand  a  IL\^!T  "'^'"'^ '  ^^^  ^''^''^^  of 
may  be  used  to  discharge  the  iron.  Coflee  stains  remnvi^^  T""' '  •  *^^"  °-^«"«  ^^^^ 
careful  soaping,  at  the  temperature  of  ]20OF    followed  hv*  Tk^'"^-  ^^'^  ^^*^^>  ^"^  » 

prl^^ci::^^^^^^  be  corrected  by  ap, 

acid,  the  stain  is  best  counteracted  bv  the  annl.vJ.       "r  ^''''^''  *^^«^*^  '«  reddened  by  an 
Silk  colors  are  injured  by  soapror  alkaline'^^at  p?.  1  ''^'''  «*' ^'""^onia.     If  delicate 
colorless  vinegar  of  moderate  force      An  rrt,?v.   '  '  ^^  r^*"'  "^"^^  ^«  ^^^ted  with 
made  as  follows :  -  Take  f"ller%e;rth^  freest  VoTnT^^^^^  '""""^"^  ^''^''  «P«^«  « 
water  ;  mix  with  half  a  pound  of  threa  th%o  '  eLri^h    2^  matter  by  elulrialion  with 
«oap  and  eight  yolks  of  eggs  well  beafu  ,  whh  Zf^'    ""^^  T""^  ""^  ^«^«'  ««  »«"<^h 
whole  must  be  carefully  triturated  upon  a'poZy.^  ih  T."''  ^'^i  ^""'^^^  «^-?^^^-     The 
same  manner  as  colors  are  ground,  mix"n^  in  Sad  Inl  ^k'   ^^^  '"^^  "^'^^  *^^  ^^«^P  ''^  the 
ly  beat  together.     Incorporate  neirthe  foft  earfh  k/  .     ^T  ^"^  '^^  ^^-"«"  P^^^i««^ 
paste  be  formed,  which  should  be  made  into  hTnln  ^  5^°'''  ?^^'^^''  *'"  ^  ""^^orm  thick 
out  to  dry.     A  little  of  this  determent  beTn°  tr!    a  ""1^^^  ^[^  convenient  size,  and  laid 
with  water,  and  applied  to  the  stafn^wHl  remove  7t  "  p'^'i  /  ^""''  '"''^*^  ^"^°  ^  ^^^^^^ 
through  Its  own  bulk  of  water,  appli^^to  thesnot.  n,hhT^1.  •'■^'"  ^'  ^«  ^'^  ^'^^^^^ 
till  they  disappear,  after  which  the  stuff  is  tote  w«?h    1     "^k"  'T  ^^"°^  ^^^^  the  hands 
substance  for  removing  stains  on  woollen  clothes  "*  ""''^  '""  ^^'"^-     ^^  ^«  ^^e  best 

or  a  tXot:11.^ir^^^^^^^^^^^^^  "Pon  the  dry  clothes  with  a  sponge 

with  some  plastic  clay  rediced  lo^'.wder      WiE  Jh^r'"      ''-^'"""'^'^ 

formed  round  the  stain,  as  large  a.  i/ie  part  mn/C       i    ''u^'u"^^"^*^"*  *  *^^«"d  would  be 

Oxalic  acid  may  be  applied  in  nowul Tri    ?i^^"^^  "^'^^  *^^  turpentine, 
well  rubbed  on,  a'nd  ihelZ.'^^Tor::^^^^^^^^^  ^'^^--^y  -oi^tened  with  watei, 

Sulphurous  acid  is  best  ffpnpmt*..!  «»  »k  ^aier. 

stained,  they  should  be  susSdt'  a'  oV"di„TrvTmilr""\"-  J'  ^^^  ^'«^^-  ^^  -"- 
the  sulphur  may  be  burned  under  the  w  de  e7d  of  1"^'"?,  "^^'?^'''  ^"^  ^"«'"^  ^^^ms, 
upper  orifice  is  applied  near  the  cloth  ^  ^  '"^"  ^^'^  °'  P^P^''  ^""nel,  whose 

Manipulations  of  the  sccmrer  —ThPQP /.nn.-  ♦  «    .  • 

water,  or  in  soap-water.    The  cloth  must  hf'     f ' '"  "^l'^'""  ^^^  ^^"^^^^^  '"  clear  soft 

rubbed  with  the  appropriate  reageitraLve  "d'es  ritf '??  °"k  "  ^^^'''"^  ho^r^.^nl 

hard  brush.     The  application  of  a  redStTon  a  HUle  wl'^'ilf'  ^"^  *  ?P^"^«  «^  «  ^mall 

volatilizes  the  greasy  matter  out  of  it     Stl'n"  of  n  t^h  t{  ^i!"  *  moistened  spot  often 

become  dry.  must  first  be  softened  with  a  ifttt  K'  uT'  T'\  P*''?*'  ^^^'^^^  »^«^« 

with  the  powder  of  the  scouring  ball      Whe,       p  l\    \^    u""  ""^  ^^'■^'  *"^  ^hen  treated 

be  restored  by  applying  the  fiterld  m^cuLe  of  tm  f^^^^^^^^  'f^"  ^^""^  «'^^''  ^^  "^^^ 

a  frame  to  dry.     Ribbo^ns  are  glossed  with¥nglasfTpT'^"'' '  stretching  it  „poi 

SCR  W'  M  "■  *^'^  ^^""^  ^"""  cleane  l!  ^  ^'"^""  J"''^  ^«  "^^^  ^o  brighten 

Taper  wckkI  sc/ewJhHron.f;:^,  fi^dtoS'-  l;'^',  ^--'^/— i»^-v/a..«r^. 
description,  and  for  stoves  grate,  etc  ^^  ^""^  "^'^"^^  ^«''  machinery  of  every 

SSr  L"'te^:^;;t^^^^^  «-  cabinetwork, 

making  machine,  a  pLe  suffictnrt"  fTrmtscretT'^'l'  '^^  '"^''.^"^^^  '"*"  «>«  '^^^rew- 
is  to  say,  the  portion  which  forms  the  head  if.  '"S'^^'  '^""^^  "P  ^"^  ^^a^ed,  that 

♦'  blank"  is  dropped  into  a  receXlf  Llow  '  n  P  •'''''*^  '"*"  ^'^^P^  ^"'^  the  now  caUed 
and  smoothing  the  counteS  which  i7npr?P^^^^^^  2  consists  in  flatteaiing  the  head 
clams  and  having  a  cutLr  revoTv^nl  in  ^tJlT''^  ^^  '^l  "^'*"'^"  ^^'"^  ''^I^  ''"  both 
"  blank"  is  placecl  in  a  pair  of  nTpner?  whirhT'  """"^  u?"^^^'"  *'"^'"^-     ^'  ««"i"^:    th* 

action  ;  the  head  is  pre^seS  ISt  a  smaU  rplir''^''-""^"''""''  ^^  "^'^^"='  "^  «  ^^^o^ 

i'  against  a  small  revolving  circular  saw,  and  the  slit  made 


1238 


1239 


1240 


4.  Threading  is  effected  by  the  "  blank"  being  introduced  into  a  pair  of  clams  which  is 
attached  to  a  spindle,  the  back  part  of  which  is  cut  with  a  wonn  or  thread  corresponding 
to  that  of  the  screw  to  be  cut,  and  which  propels  forward  the  clams  and  the  "  blank" 
against  small  toothed  cutters,  which  groove  out  the  thread ;  three  runnings  down  are  suf- 
ficient to  complete  the  manufacture  of  an  ordinary  sized  screw.  The  diflference  in  the 
fineness  of  the  threads  arises  from  the  shape  of  the  cutters. 

SEAL  ENGRAVING.  Tlie  art  of  engraving  genis  is  one  of  extreme  nicety.  The 
stone  having  received  its  desired  form  from  the  lapidary,  the  engraver  fixes  it  by  cement 
to  the  end  of  a  wooden  handle,  and  then  draws  the  outline  of  his  subject  with  a  brass 
needle  or  a  diamond,  upon  its  smooth  surface. 

FHg.  1237.  represents  the  whole  of  the  seal 
engraver's  lathe.  It  consists  of  a  table  on 
which  is  fixed  the  mill,  a  small  horizontal 
cylinder  of  steel,  into  one  of  whose  extremi- 
ties the  tool  is  inserted,  and  which  is  made 
to  revolve  by  the  usual  fly-wlieel,  driven 
by  a  treddle.  Tlie  tools  that  may  be  fitted 
to  the  mill-cylinder,  are  the  following :  Jig. 
1238.  a  hollow  cylinder,  for  describing  circles, 
and  for  boring;  Jig.  1239.  a  knobbed  tool, 
or  rod  terminated  by  a  small  ball ;  Jig. 
1240.  a  stem  terminated  with  a  cutting  disc, 
whose  edge  may  be  either  rounded,  square, 
or  sharp ;  being  in  the  last  case  called  a  saw. 
Having  fixed  the  tool  best  adapted  to  his 
style  of  work  in  the  mill,  the  artist  applies 
to  its  cutting  point,  or  edge,  some  diamond 
powder,  mixed  up  with  olive  oil ;  and  turn- 
ing the  wheel,  he  holds  the  stone  against  the 
tool,  so  as  to  produce  the  wished-for  delinea- 
tion and  erosion.  A  similar  apparatus  is 
used  for  engraving  on  glass. 

In  order  to  give  the  highest  degree  of 
polish  to  the  engraving,  tools  of  boxwood, 
pewter,  or  copper,  bedaubed  with  moistened  tripoli  or  rotten  stone,  and  lastly,  a  brush, 
are  f,istened  to  the  mill.  These  are  worked  Like  the  above  steel  instruments.  Modern 
engravings  on  precious  stones,  have  not  in  general  the  same  fine  polish  as  the  ancient 
The  article  Gems,  in  Bees'  Cyclopcedia,  contains  a  variety  of  valuable  information  on  tliia 
eubject,  equally  interesting  to  the  artist  and  the  scholar. 

SEAL  FISHERY.  The  seal  fishery  of  Newfoundland  has  now  become  the  most 
important  part  of  the  trade  of  that  colony.  Although  not  so  extensive  a  staple,  or  so 
generally  followed  as  the  cod  fishery,  yet  when  the  capital  and  time  employed,  and  the 
almost  certain  and  immediate  return  for  investment,  are  taken  into  consideration,  it  is  by 
far  the  most  profitable  part  of  the  business  of  that  colony,  or  perhaps  of  any  otUer  part 
of  the  British  empire. 

A  quarter  of  a  century  ago,  there  were  only  about  50  vessels,  varying  from  30  to  60 
tons  burthen,  engaged  in  this  branch  of  trade ;  but  within  that  period  it  has  been  gradu- 
ally increasing.  In  the  year  1860,  the  outfit  for  this  fishery  from  Newfoundland  consisted 
of  229  vessels,  of  20,581  tons,  employing  7,919  men.  The  number  oi  seals  taken  was 
440,828.  According  to  the  custom-house  returns  for  that  year,  the  total  value  of  skins 
and  oil  produced  from  the  sale  amounted  to  298,796/.  In  the  present  year,  1852,  the 
outfit  consisted  of  3G7  vessels,  of  35,760  tons,  employing  about  13,000  men.  The  returns 
and  value  of  this  year's  fishery  have  not  yet  been  ascertained.  Although  it  was  a 
disastrous  season,  in  respect  to  loss  of  vessels,  yet  the  catch  of  seals  upon  the 
whole  was  above  an  average  one,  there  being  from  half  to  three-quarters  of  a  millioa 
seals  captured. 

The  vessels  engaged  in  this  business  are  from  75  to  200  tons  burthen.  Tliose  lately 
added  to  the  sailing  fleet,  and  which  are  now  considered  of  the  most  suitable  sizes,  range 
from  130  to  160  tons.  Vessels  of  this  size  carry  from  40  to  50  men.  The  season  of 
embarking  for  the  voyage  is  from  the  1st  to  the  15th  of  March.  The  voyage  seldom 
exceeds  two  months,  and  is  often  performed  in  two  or  three  weeks.  Several  vessels 
make  two  voyages  in  the  season,  and  some  perform  the  third  voyage  within  the  space  of 
two  months  and  a  half 

The  seals  frequenting  the  coast  of  Newfoundland  are  supposed  to  whelp  their  young 
in  the  months  of  January  and  February ;  this  they  do  upon  pans  and  fields  of  ice,  on  the 
coast,  and  to  the  northward  of  Labrador.  This  ice,  or  the  whelping  ice,  as  it  is 
termed,  from  the  currents  and  prevailing  northerly  and  north-east  winds,  trends  towanla 


h 


690 


SEAL  FISHERY. 


SEALING-WAX. 


the  east  and  north-east  coast  of  Newfoundland,  and  is  alwavs  in  Ko  a.««j  ««  -«««  —a 
of  the  coast  after  the  middle  of  March,  before  Xhlime'TSy^u^g'^L^^^  Z  ^^o^n"^ 
to  be  profitable.  The  young  seal  does  not  take  to  the  water  until  his  three  month! 
o^d.  They  are  often  discovered  in  such  numbers  within  a  day"  s^l  of  the  porTthaJ 
tTr  7  ^:ru^7lJ'^}  '."^"^  *«  ^^^  »  ^««««1  ^it»»  the  pelt,,  Xrconlist  of^he  Ikfn 
novIt'"stftoi';L''^^  'th'"  off  while  the  animal  ?s  wirmrL'^'^l^lLXo? 
f-V  /  !V  **°  ^°®  **^-    ^^'^  y°""?  seals  are  accompanied  by  the  old  ones  which 

take  to  the  water  on  the  approach  of  danger.  When  the  ice  is  jammed  and  the;e  is  no 
open  water,  large  numbers  of  the  old  seals  are  shot    The  youngTaU  are  e^ilv  VZ 

1^:1'  IZfLVJtJT'iT^  '  slight  stroke  of  a  bat  o^  V^ead  rea'^Vd'te 
nnAlrV     T^K  P!i     ^'^^^  *^^'^"  °°  ^^^^'  suflScjent  time  is  aUowed  for  them  to  cool 

?he  market  at%t'joW°  ''7'.t  *^^V".^""^  ^^/^^  ^-^<^'  ^nd  in  this  state  th"yre^h 
r^Lh  ^tllf  T  ^  .  "  ^,  *""*  ""i^^f  P^''*  '°  ^^^  •«^*°^-  Five-sevenths  of  the  whole  catch 
W  fhl       ••  "^.f "  «  °^f  ket.    A  thousand  seals  are  considered  as  a  remuneratirnumber 

6  000  IT'"'^  "•  K^'  ^"''"^'  ^^'""^  ^'^^  "P^^^^d^  «f  3,000,  many  with  IS^and 
h^i.L  i  '"""^  "^"^^  ^,  "'^^y  ^  '^'^«^'  S'^^^'  *°^  »'000-  Seals  were  formerly  soM 
by  tale  ;  they  are  now  all  sold  by  weight,-that  is,  so  much  per  cwt.  for  fat  anTsWa 

cond  .  P7*r^  'P'"^"'  '^P'"^"^  ^••^  '^«  *^««d  *°d  harp  seal.  The  bu  k  of  the  ^atch 
consists  of  the  young  hood  and  harp  in  nearly  equal  proportions,  lie  be.  and  most 
productive  seal  taken  is  the  young  harp.  There  are  generally  four  different  a uaimes 
at?p^^^;^^''^^'^?f"^^r*^"y°"°^  harp,  young  ho^,  old  harp  anri^dlarr  the 
It  V.  ^V^^u  "i^  ^^°«<^)'.«"J  ^e  old  hood.  There  is  a  difference  of  2?  per  cw  in 
the  value  of  each  denomination.  P  *  *° 

from  th^/'irfhh  ^^'''  ^^"ff  and  weighing  is  the  skimming,  or  separating  the  fat 
irom  the  skip ;  this  is  speedily  done,  for  an  expert  skinner  will  skin  from  300  to  400 
young  pelts  in  a  day.  After  being  dry-salted  in  bulk  for  about  a  month  ^he  skins  are 
sufficiently  cured  for  shipment  the  chief  market  for  them  being  Grelt  Brit^  m 
fet  is  then  cut  up  and  put  into  the  seal- vats.  ^"lam.     ine 

The  seal-vat  consists  of  what  are  termed  the  crib  and  pan.  The  crib  is  a  strong, 
wooden  erection,  from  20  to  30  feet  square,  and  20  to  25  feet  q  height  It  is  firmlv 
secured  with  iron  camps,  and  the  interstices  between  the  upright  posts  are  filled  S 

tont  '  Th!  :T ^  Pt"     ^'  .^^  "  ^*^^°^  *'^^^^  fl^"-'  capable^of^usLinTng  300  or  4oS 
tons.     The  crib  stands  in  a  strong  wooden  pan  3  or  4  feet  larger  than  the  square  of  thp 
crib,  so  as  to  catch  all  the  drippings.     The^^pan  is  about  3  fee?  deep  and  tiSuyc^^^^^^^^ 
A  small  quan.t;jr  of  water  is  kept  on  the  bottom  of  the  pan,  for  the  douT  purZe  of 
fnr^^      '.r^  '^  '^'^  ^^  ^  ^"^^'  ^^  ^°^  P""^^'^"^  it  fro^  the  bl<^  and^anTother 

^  ifiln^"r-  °^  '7'?^'  ^'^'''^-  ^^  '^^^^^^^  ^y  *W«  P'«^«««  i«  aU  cold-drawn  no 
Whtfl  ^'^^\''^PP}'^^  ^»  any  way,  which  accounts  fir  the  unpleasant  smell  of TeaUa 
When  the  vats  begin  to  run,  the  oil  drops  from  the  crib  upon  the  water  in    he  p^ 

whlh  5  ««^»"1"^^*"'  ^*  ''-"^^^^  °^'  ^°^  '^^^y  f«^  shipment  The  first  runnhfc' 
which  IS  caused  by  compression  from  its  own  weight,  begins  about  the  10th  of  May 

^ni  in  T^T'  *^  ^'^\^  ^>\^  ''  *"^"^"^  P""^'  ''^^^^^  fro«^  two  to  three  months,  S 
from  60  to  70  per  cent,  of  the  quantity  is  drawn  off,  according  to  the  season   or  in 

fhTsTs'noT  «?f ?/  ^""t '^  '^  °^^  ''^^  ^"'  ^^  P"^  ^^*«  '^'  ^**«-  ^'o™  beingToughe ° 
this  IS  not  acted  upon  by  compression,  nor  does  it  yield  its  oil  until  decomposition  takes 

from   he  vats  is  much  freer  from  smeU  than  tfe  latter!^   As  decomposition  takes  dE 

darketanH    rf '  *"  «traw  becoming   every  day,  as  the  season  advances,  darker  a?d 

slackens^t  Cn  K^  """""'^  ^°^  ^''''^'  "°*^^ ''  ^"^^^^^  ^""^  ^'"^^^  «il-  A«  this  running 
slackens,  it  then  becomes  necessary  to  turn  over  what  remains  in  the  vats.     The  crib 

being  generally  divided  into  nine  apartments  or  pounds,  this  operation  is  performed  by 
first  emptying  one  of  the  pounds,  and  dispersing  the  contents  over  the  others  aTd  then 
filling  and  emptying  them  alternately  until  the  entire  residue,  by  this  time  a  comDlete 
S,t1n'//"'^^"'"""'  -^^  *""^«^  o^er  By  this  process  a  furthe;  rLning  rbrown  oTi! 
?h.  "k  i  ^^  '"""^'"f  *'^*^^"  ^°*"^  ^^^^  «"t  in  large  iron  poU,  which  duHng 
the  whole  season  are  kept  in  pretty  constant  requisition  for  boiling  out  the  cutt'^^s 
and  clippings  of  the  skinning  and  other  parts^f  the  pelts,  whifh  H  is  not  fS 
advisable  to  put  into  the  vats.  The  produce  of  this,  and  t^he  remains  of  the  vats  are 
what  IS  termed  the  boiled  seal  oil.  These  operations  occupy  about  six  mon  hs  and  ter^ 
mmate  towards  the  end  of  September.  ^^  "iuuuis,  ana  ter- 

v^f^'^jiw^W  "'''''*^'  ??  '^"^^'  ^"S"«t,  and  September,  the  smell  and  effluvia  from  the 
vats  and  boiling  operation  are  almost  insufferable.  The  healthy  situation  of  St  John's 
fn>m  Its  proximi  y  to  the  sea,  and  the  high  and  frequent  lo  J  winds,  is  doub tles^  the 
cause  of  preventing  much  sickness  at  this  season  of  the  year.  I  have  never  known  any 
d^se  or  epidemic  attributable  to  such  a  cause.  The  m^n  more  immediately  employed 
about  the  seal-vats  have  a  healthy  and  vigorous  appearance.  employed 

Some  improvement  has  taken  place  since  the  great  fire  of  1846,  when  all  the  seal-yata 


691 


in  the  town  were  destroyed.  Many  of  the  manufacturers  have  erected  their  new  vats  on 
the  south  or  opposite  side  of  the  harbour ;  but  there  still  remains  suflicient  vestiges  of  the 
seal  trade  to  cause  a  summer  residence  in  the  town  of  St.  John's  anything  but  desirable. 
Even  the  country  for  several  miles  around  St  John's  affords  no  protection  from  these 
horrible  stenches.  The  animal  remains  from  the  vats,  and  the  offal  from  the  codfish,  are 
found  to  be  such  a  valuable  manure,  that  they  are  readily  purchased  by  the  farmers  in  the 
neighbourhood ;  and  from  whatever  quarter  the  wind  blows,  the  pedestrian  in  his  rural 
walk  has  little  chance  of  breathing  a  genial  atmosphere. 

After  a  year's  residence  in  Newfoundland,  the  attention  of  the  author  was  turned  to 
some  mode  of  improving  the  manufacture  of  the  seal  oil.  The  result  of  several  exj>eri- 
meuts  upon  the  different  qualities  of  seal's  fat  satisfied  him  that  the  whole  produce  of  the 
fishery,  if  taken  while  the  material  is  fresh,  as  it  generally  arrives  in  the  market,  and 
subjected  to  a  process  of  artificial  heat,  was  capable  of  j'ielding,  not  only  a  uniform  quality 
of  oil,  but  the  oil  so  produced  was  much  better  in  quality  than  the  best  prepared  by  the 
old  process,  and  free  from  the  unpleasant  smell  common  to  all  seal  oil.  His  subsequent 
experiments  resulted  in  the  invention  of  a  steam  apparatus  for  rendering  seal  and  other 
oils,  which  has  been  found  to  answer  an  admirable  purpose,  and  for  which  he  has  received 
letters-patent  under  the  Great  Seal  of  the  Island  of  Newfoundland,  securing  to  him  the 
right  of  his  invention  for  fourteen  years. 

The  advantage  of  this  process  must  be  manifest,  when  it  is  understood  that  twelve 
hours  suffice  to  render  the  oil,  which  by  the  old  process  requires  about  six  months ;  that 
a  uniform  quality  of  oil  is  produced  superior  to  the  best  pale  by  the  old  process,  and  free 
from  smell ;  that  a  considerable  per-centage  is  saved  in  the  yield,  and  what  is  termed 
pale  seal,  produced  from  the  old  as  well  as  from  the  young  seal.  (The  sample  herewith 
sent  Dr.  Ure  is  from  the  old  hood  seal.)  Besides,  if  this  process  were  universally  adopted, 
the  manufacturing  season  woujd  cease  by  the  31st  of  May,  and  the  community  would  be 
saved  from  the  annoyance  attending  the  old  process. 

The  chief  market  for  seal  oil  and  skins  has  hitherto  been  Great  Britain  and  Ireland :  a 
few  cargoes  occasionally  go  to  the  continental  cities.  This  year,  for  the  first  time,  a  new- 
market  for  seal  oil  has  been  opened  in  the  United  States,  owing  to  the  greatly  increased 
consumption  of  oil  in  that  country,  together  with  the  failure  of  their  whale  fishery. 
Upwards  of  2000  tons  of  this  year's  produce  have  already  been  shipped  to  that  country. 
The  latter  shipments,  however,  have  not  realised  to  the  shippers  the  prices  of  the  first, 
from  the  fact  that,  upon  the  trial  of  this  oil,  although  it  was  found  to  be  valuable  for  its 
combustible  qualities,  yet  in  a  hot  climate  it  was  altogether  unfit  for  domestic  purposes, 
on  account  of  its  singularly  offensive  smell. 

In  the  United  States  the  great  consumption  of  oil  is  for  domestic  purposes ;  the  chief 
dties  only  as  yet  being  lighted  with  gas,  and  that  but  partially,  from  their  constant  in- 
crease. Candles,  unless  of  the  most  expensive  kind,  will  not  suit  that  climate,  particu- 
larly in  the  summer  season ;  and  hence  oil  and  camphene,  where  gas  is  not  used,  are  the 
chief  ingredients  for  lamps.  All  animal  oils  used  in  that  country,  whether  of  sperm,  right 
whales,  or  lard,  are  rendered  by  artificial  heat,  and  in  consequence  free  from  the  un- 
pleasant smell  of  our  cold-drawn  seal  oil 

From  his  having  exhibited  samples  of  his  oil  in  America,  the  subscriber  has  fully 
ascertained  that,  on  account  of  its  yielding  so  brilliant  a  light,  and  producing  no  offensive 
smell,  it  will  command  a  much  higher  price  than  the  best  pale,  prepared  by  the  cold- 
drawn  process. — 8.  G.  Archibald,  St.  John's^  Newfoundland. 

SEALING-WAX.— (Circa  cacA^<tfr,Fr.;  Siegellack,  Germ.)  The  Hindus  from  time 
immemorial  have  possessed  the  resin  lac,  and  were  long  accustomed  to  use  it  for  sealing 
manuscripts  before  it  was  known  in  Europe.  It  was  first  imported  from  the  East  into 
Venice,  and  then  into  Spain  ;  in  which  country  sealing-wax  became  the  object  of  a  con- 
siderable  commerce,  under  the  name  of  Spanish-wax. 

If  shell-lac  be  compounded  into  sealing-wax,  immediately  after  it  has  been  separated  by 
fusion  from  the  palest  qualities  of  stick  or  seed  lac,  it  then  forms  a  better  and  less  brittle 
article,  than  when  the  shellac  is  fused  a  second  time.  Hence  sealing-wax  rightly  pre- 
pared m  the  East  Indies  deserves  a  preference  dver  what  can  be  made  in  other  countries, 
where  the  lac  is  not  indigenous.  Shellac  can  be  restored  in  some  degree,  however  to  a 
plastic  and  tenacious  state  by  melting  it  with  a  very  smaU  portion  of  turpentine. '  The 
palest  shellac  is  to  be  selected  for  bright-coloured  sealing-wax,  the  dark  kind  being  re- 
served for  black.  ° 

The  following  prescription  may  be  followed  for  making  red  sealing-wax  .—Take  4 
ounces  of  shell-lac,  1  ounce  of  Venice  turpentine  (some  say  \\  ounces)  and  3  ounces  of 
yermillion.  Melt  the  lac  in  a  copper  pan  suspended  over  a  clear  charcoal  fire,  then  pour 
the  turpentine  slowly  into  it  and  soon  afterwards  add  the  Vermillion,  stirring  briskly  all 
the  time  of  the  mixture  with  a  rod  in  either  hand.  In  forming  the  round  sticks  of 
sealing-wax,  a  certam  portion  of  the  mass  should  be  weighed  while  it  is  ductile,  divided 
into  the  desired  number  of  pieces,  and  then  rolled  out  upon  a  warm  marble  slab,  by 


592 


SEA  WATER. 


of  ftusion.     The  marks  ffX  iLerof  luucS 'oT  tl  ,^  above  compound  m  a  atate 

removed  by  holding  the  sticL  over  a  cC  firp  o/l^"'""u'^-^^  °^^^  ^^  afterwards 
HT    ui    1        1  o  "^."^  BUCKS  over  a  ciear  nre,  or  passins:  them  over  a  hlnp  iras-flamp 

Marbled  seahng-wax  is  made  by  mixing   two.  three.   or'morT  Xured    kin!i?  ofTt! 

Either  lamp  black  or  ivory  black  serves  for  the  colourinff-matter  of  H»^w! 5  =    •■ 

The  following  prescriptions  are  good  •— 
cmttfL'"*  *"•  ^'"''"*°  '"P""'"''  «  "^   ^^-^'  *  <»^  "lophony,  U  oz. 
ma^ltir''"'''"""^  ■"'  ""'"-"^  "■'^  ^"^  '-  «<"»?'"'■'?  »<<  «»-bar  each  1*  ox., 
m^^nlit^c'""''  ""•  '"P*""""'  '*  "^'-  ^•''"•"«'  1*  «•  "'•»P'«>°y.  li  «-  cinnabar, 

b,af  LigtirhlaTf-tlr^/n't  IsTuoltlsV^^r"''^  *  "^-  -<""«»'y-  -P" 
oaTt'^^enZe  ''""'"'"  '"'P'"""''  *  ""•  *'"-'^'=-  «  "^  ""ophooj,  Ump-bUck,  and 

4tUarn,r;net°an^Toft"uVnre^'^"-'^  ^*  "^-  "''"P^-^'  *  -  '""S'' 
ear^hti^^rL^er  Jrr  '"''"'''°^'  '*  ""•  **"•■-•  '*  '-  •"o™  English 
ear^hl^^ii^^xtaglr  rawr'"'-  '  °^'-  ^'"'"■"^  "  ""■  «>'''?■-?.  H  <>-  EngU.h 
4;«~prdIhTlfr„"a^r^^^^  ^-^"-'-^  '  o^-O-wn  earth.  *o. 

».i^::;fbfi::^4:::iaLTre  *"'""''''''' '  "^  *■«'  '"'"'■''"=■  ^  <»•  ""opw.  i  <.. 
ye.t;Toiroirt"e,!::p^::iritc  ^'"''-'^  '*  »^-  '"'»p'-<'"^-  *  -  >^-8'» 
ch|r;:d,ttr^rgoTra.''j;^VKf"t%tt^-  '-^"-'^  ^  -  -•"p-'-^-  ^  »- 

brot??tri^'et'':Sunu?p:X'^"-^"^  "  »"-''  of  S-"-  '-^Sold.  ioz. 

ihf^n'l^^'^^-^'  '^^^TP""'^^  ^  ^«"«^^'  according  to  the  author  of  the  artirlo  ^.;-„     • 
the  Dictionnaire  Technologique  .-—Chloride  of  sodium    OKn       m     j       ?    ^<'^»'*<^*.  >" 
0-35 ;  sulphate  of  magnesia  0-58  •  carbonatprnf^mo  '   a^  '   ^'^^^"^^  ""^  magnesium, 
limo,  001?  water,  96^ri00  paVtT  Se^^^^^^^^^  LT  "^  '°'^°""'  '•'' '  ^"^P^^^«  ^^ 

bea-water,  distillation  of.     ITiree  of  TTpr  Mai'oo^^'..  ^i.-       a^ 
Fitzroy.  the    Plumper,  l^  cl^^JeJ^LuoTi:^^^^^^  ?^^^P*r 

Crawcroft,  have  been  furnished  with  the  Government  di^trnfr:!  '  ,9«°^°^ander 
constructed  by  Mr.  Grant:  other  gaUeys  of  t^,e  s™me  kind  I^!  ^  ^""^  ^^^''"^  ^^"^y* 
facture  for  the  largest  class  of  ^essL.  The  iSunUess  1496  ?on"  T' t  °^  °^"""- 
1.556  tons,  and  the  Encounter,  906  tons,  all  Lw  shins  on  tL«^'  ^  Termagant, 
ordered  to  have  first  class  machines  of  the  aW  descriDt^on  L  I^  .P"°^'P'«'  ^^ 
made  smce  the  introduction  of  the  galleys  into  the  nfv/l  P^^J"  I  *^®  ""P'-ovements 
water  obtained  by  the  distillation  o^f  saTwater  durin^^^^^^^  quanity  of  fresh 

the  fires  alight  in  the  gallev  for  the  purDoses  ofT?-  P-n"*^  '^  l^  required  to  keep 
each  individual  on  boarl  the^veLels  wi?h  Te  '  ^^^^^^  «"  ^^e  average,  suppl^ 

latter  kind  of  water  continues  to  be  preferred^for  ^^^^^^  "^^'^  ^^y  '     ^ho 

water  usually  supplied  to  the  shins  •  it  casses  mnlT  . ¥  r^  ^"V""^  purposes  to  the 
water  tanks^it  t£e  same  ter^Sure  ^^  th^r^  *^^  condenser  into  the 

becomes  perfectly  aeraJ^^loX  aWether^L  vT^^  '^''^°-  ^°  *^^«^  *^»^^«  ^^ 
water  in  the  course  of  a  few  hfurs  without  tJP-^^7"^^^^^  *«  *"  ^»«tilled 
mechanical  arrangement,  br^eZnle  fact  of  It  ^T-"^  ^^  "^^"'^^^  preparation  or 
motion  of  the  shiS  when'at^se"  Tsties  of  vert  LprlT  '"P";'-"^  *^  '^'  ^"^^  ^^  *»»« 
have,  however,  been  made,  and  are  still  i^U^f^^  ^u^ '?P°'*^"^  ^^P""'^^"*^ 
Captain  Yat.;    bearing  the  f^V  ^  Z^S{^^Z,''c^t  KhiS,  l^' 


SEWING  BY  MACHINERY. 


693 


Mr.  Cross,  with  the  view  of  imparting  at  the  moment  of  distillation  the  oxygen  of  which 
the  water  is  deprived  in  the  process,  and  giving  to  it  that  briskness  which  is  found  in 
epring  water  This  is  effected  by  passing  a  proportionate  current  of  electricity  through 
the  oarticles  of  water  by  means  of  an  extremely  simple  and  self-acting  apparatus.  The 
results  ()f  tlie  experiments  made  have  been  highly  satisfactory.  The  only  point  to  be 
determined  is,  whether  any  artificial  means,  either  chemical  or  mechanical,  are  required 
for  aerated  distilled  water  on  board  ship,  as  it  is  found  that  such  water  becomes 
sufficiently  aerated  in  a  few  hours  by  the  motion  imparted  to  it  by  the  ship;  but  if 
the  water  is  required  for  immediate  use,  Mr.  Cross's  application  produces  the  object 
desired  most  effectually. 

SEGGAR,  or  SAGGER,  is  the  cylindric  or  oval  case  of  fire-clay,  in  which  fine 
stoneware  is  enclosed  while  being  baked  in  the  kiln. 

SELENIUM,  from  IieXijvT},  the  moon,  is  a  metalloid  principle,  discovered  by  Berze- 
lius,  in  1817.  It  occurs  sparingly  in  combination  with  several  metals,  as  lead,  cobalt, 
copper,  and  quicksilver,  in  the  Harz,  at  Tilkerode ;  with  copper  and  silver  (Eukairite) 
in  Sweden,  with  tellurium  and  bismuth  in  Norway,  with  tellurium  and  gold  in 
Siebenbiirgen  ;  in  several  copper  and  iron  pyrites,  and  with  sulphur  in  the  volcanic  pro- 
ducts of  the  Lipari  Islands,  Selenium  has  been  found  likewise  in  a  red  sediment  which 
forms  upon  the  bottoms  of  the  lead  chambers  in  which  oil  of  vitriol  has  been  made  from 
a  peculiar  pyrites,  or  pyritous  sulphur.  The  extraction  of  selenium  from  that  deposit  is 
a  very  complex  process. 

Selenium,  after  being  fused  and  slowly  cooled,  appears  of  a  bluish-gray  colour,  with  a 

f  listening  surface ;  but  it  is  reddish  brown,  and  of  metallic  lustre  when  quickly  cooled. 
t  is  brittle,  not  very  hard,  and  has  little  tendency  to  assume  the  crystalline  state. 
Selenium  is  dark-red  in  powder,  and  transparent,  with  a  ruby  cast,  in  thin  scales.  Its 
specific  gravity  is  4'30.  It  softens  at  the  temperature  of  176°  P.,  is  of  a  pasty  con- 
sistence at  212°,  becomes  liquid  at  a  somewhat  higher  heat,  forming  in  close  vessels  dark- 
yellow  vapours,  which  condense  into  black  drops;  but  in  the  air,  the  fumes  have  a  dn- 
nabar-red  colour. 

This  singular  substance,  apparently  intermediate  in  its  constitution  between  sulphur 
and  metals,  has  not  hitherto  been  applied  to  any  use  in  the  aits. 

SELF-ACTING  MACHINES.     See  Machines. 

SELTZER  WATER.    See  Soda-water,  and  Watees,  Minkeal. 

SEMOULE.  The  name  given  in  France,  and  used  in.  this  country,  to  denote  the 
large  hard  grains  of  wheat  flour  retained  in  the  bolting  machine  after  the  fine  flour  has 
been  passed  through  its  meshes.  The  best  semoule  is  obtained  from  the  wheat  of  the 
southern  parts  of  Europe.  With  the  semoule,  the  fine  white  Parisian  bread  called 
ffruau  is  baked.  Skilful  millers  contrive  to  produce  a  great  proportion  of  semoule 
from  the  large -grained  wiieat  of  Naples  and  Odessa. 

SEPIA,  is  a  pigment  prepared  rrom  a  black  juice  secreted  by  certain  glands  of  the 
cuttle-fish,  which  the  animal  ejects  to  darken  the  water  when  it  is  pursued.  One  part 
of  it  is  capable  of  making  1000  parts  of  water  nearly  opaque.  All  the  varieties  of  thia 
mollusca  secrete  the  same  juice;  but  the  Sepia  officinalis,  the  Sepia  ioligo,  and  the  Sepia 
tunicata,  are  chiefly  sought  after  for  making  the  pigment.  "  The  first,  which  occurs  abun- 
dantly in  the  Mediterranean,  affords  most  color ;  the  sac  containing  it  being  extracted 
the  juice  is  to  be  dried  as  quickly  as  possible,  because  it  runs  rapidly  into  putrefaction! 
Though  insoluble  in  water,  it  is  extremely  diffusible  through  it,  and  is  very  slowly  de- 
posited. Caustic  alkalis  dissolve  the  sepia,  and  turn  it  brown ;  but  in  proportion  as  the 
alkali  becomes  carbonated  by  exposure  to  air,  the  sepia  falls  to  the  bottom  of  the  vesseL 
Chlorine  blanches  it  slowly.  It  consists  of  carbon  in  an  extremely  divided  state  alons 
with  albumine,  gelatine,  and  phosphate  of  lime.  * 

The  dried  native  sepia  is  prepared  for  the  painter,  by  first  triturating  it  with  a  little 
caustic  ley,  then  adding  more  ley,  boiling  the  liquid  for  half  an  hour,  filtering  next 
saturating  the  alkali  with  an  acid,  separating  the  precipitate,  washing  it  with  water,  and 

^'^oi^J.i^i??**'  ^^1^*  ^^?^^^  ^^^^'     ^^^  pigment  is  of  a  brown  color,  and  a  fine  grain. 

SEPIARIA,  called  anciently  Indus  Hehnantii,  (the  quoits  of  Van  Helmont,  from  their 
form,)  are  lenticular  concretions  of  clay  ironstone,  intersected  by  veins  of  calc-spar  which, 
when  calcined,  and  ground  to  powder,  form  an  excellent  hydraulic  cement.  See  MoktI^ 
HrDRAULic.  ■^ 

SERPENTINE,  is  a  mineral  of  the  magnesian  family,  of  a  green  color :  it  is  scratched 
by  calcareous  spar,  is  sectile,  tough,  and  therefore  easily  cut  into  ornamental  forms.  It 
o«curs  in  Unst  and  Fetlar,in  Shetland;  at  Portsoy,  in  Banffshire;  in  Cornwall;  and  the 
Isle  of  Holyhead.  The  floors  of  bakers'  ovens  are  advantageously  laid  with  slabs  of 
terpentine. 

SEWING  BY  MACHINERY.  The  Wilson  machine  is  in  our  opinion  a  great 
triumph  of  American  genius  ;  it  is  no  larger  than  a  neat  small  work-box,  very  portable 


694 


SHAGREEN. 


Ai 


«nd  convenient,  and  we  have  seen  fine  shirt  bosoms  and  collars  stitched  by  it  in  a  more 
perfect  and  accurate  niauner  than  any  we  have  ever  seen  done  bj  hand-work  me™ 
we  first  noticed  How's  Sewing-machmerj,  in  1847,  there  was  not  a  solitary  machine  of 
the  kind  m  active  operation,  m  our  whole  country,  if  in  the  world  There  are  now  wa 
beheve.  about  500  m  opeijtion.  and  we  have  bei,  told  by  Mr  Wilson  thaUheordera 
for  his  machines  cannot  be  supplied  fast  enouffh  There  arp  «f  r^ri-l^f  II  a  i 
machines  about  finished  at  the  Company's  ^oT-WhZL  wtLrZ  Co  wtf 
town,  Connecticut,  and  these  are  all  engaged  *^°eeier,  wiiaon,  and  Co..  Water- 

asrcLTreToSntyr':  To^w'^tttillt^^^  ^«  -^ 

.titching  by  one  of  Wi  Jn's  little  machines  L'  algl  tu^. 'Th^tLe'^^^^^^^^^ 

wives  tailors,  and  sempstresses  of  every  description,  il  of  incalculable  TrnpoHance  for  i? 

T^Vlr  *^'"  ■?^.iZ^^^  ^^^^  ^>*"°'^«"  *«  «*»^^^  ^^^SB,  during  the  Ze  whTch  u'ed 
to  be  taken  up  with  dull  seam-sewing.     Youne  ladies  will  have  mopp  Hmo  +r!i       *  ! 

ornamental  work,  (it  would  be  bette°r  for  the^i  afu?  They  Sfd  more  o^U)  Ind  fln^He: 
m  which   here  are  a  number  of  children,  which  require  a  continual  st  tch  ^g  in  ^^^^^ 
machre"    "^    ""^  '°'""^  ''^^  "'^'''  ^^"  ^''  ^  ^1^«*«^  by  the  improv^ei  s^wbg^ 

?S A p Rir^i?''''JWl  ^'^'^^^  *  perpendicular  or  slightly  inclined  pit. 
^•ff  7?  1*,  ^^J^^Sriny  Fr.  and  Germ.)  The  true  oriental  shagreen  is  essentiallv 
different  from  all  modifications  of  leather  and  parchment.  It  approachertLlaUer  som/ 
what,  indeed  m  its  nature,  since  it  consists  of  a  dried  skin,  not  combined  wfih  an  tannTne 
or  foreign  njatter  whatever.  Its  distinguishing  character  stic  is  havTn-  iTe  47n  or  S 
side  covered  over  with  small  rough  round  specks  or  granulations.  " 

.hfii'/'^^^K  ^T/^^  skins  of  horses,  wild  asses,  and  camels  ;  of  strips  cut  alon-  the 
Sn  nV  ir  It-  "?^^»,^Tl'^«  ^*i«  tail,  apparently  because  this  st^on^;  and  Uncker^'por! 
Uon  of  the  skm  IS  best  adapted  to  the  operations  about  to  be  described.  These  fineti 
mrc  to  be  steeped  in  water  l  11  the  epidermis  becomes  loose,  and  the  hairs  easi  y  come 
away  by  the  roots ;  after  which  they  are  to  be  stretched  upon^  board/anddrested  with  the 

f  ffS  ?'^^ -'^■^."'^'-     ?^?"y  "™"^*  b^^^Pt  continually  moist,  and  extend;rbvcorf8 
attached  to  their  edges,  with  the  flesh  side  uppermost  upon  the  board.    Each  strin  now 
resembles  a  wet  bladder,  and  is  to  be  stretched  in  an  open  square  woS;n  frame  bv  meanT 
of  strings  tied  to  its  edges,  till  it  be  as  smooth  and  tense  as  a  drurhead      For  thiTnur 
pose  it  must  be  moistened  and  extended  from  time  to  time  in  the  frame  ^ 

l,;n^V**i?  *'^,^*^»^f  °^  ^^^  "^""'^^  ^^"P  «^  skin  must  next  be  sprinkled  over  with  a 
wUh  ?hfrf  t  *=^"^.,f  ^«^'«>  ^'-'hich  are  to  be  forced  into  its  surface^Xr  by  tramping 
ThX^X  T^i:^  A  kT^^"  P'Tv?  P'"^"  ^^  ^^^'  «^  ^'^^'  thick  stuff-  being^aid  u^I 
{^«T^  ;  c  J  •  tf  **f  b^'r?  P'-?^ai>Iy  to  the  Chenapodium  album.  They  are  lenticXr 
hard  of  a  shining  black  color,  farinaceous  within,  about  the  size  of  poppy  seed  and  «« 
sometimes  used  to  represent  the  eyes  in  wax  fi^-ures  ' 

^K^Ilf  f  •''r'  ^'PP'^1°  dry  in  the  shade,  with  the  "seeds  indented  into  its  surface  •  after 
?hl  nntVl  'm1  kTk^^'^  ^y  '^^^^"»  ''>  ^"^  b^^ting  upon  its  other  s  de  with  a 's?k? 
and  number  ^fre^seeS. '""''  **"'  ^^"^'  "^^'  ^"^"  ^°"^-  corresponding  toVe  st^ 

In  order  to  make  the  next  process  intelligible,  we  must  advert  tn  »n«fi,o,       i 
.nd  well-known  operation.    When  we  make'  impr^siorfn  fin^^rlreSt:  w^Tft 

p::iinr..fw\^r^;T.isrr2^^^^^^^^ 

The  strip  of  skin  is  stretched  in  an  incUned  plane,  witn  its  upper  ed<'e  attached  to  hook«- 

semitr^^'  T 'w  ^'^  "'''  \^^="'^^'  ^"  ^"^•^'^  P^^^tion  it  is'thinn^ 'rwith  a  prop5 
semi-lunar  knife,  but  not  so  much  as  to  touch  the  bottom  of  the  seed-nits  orienrrS/ 

oLTTe'TV:  XT  ?d  T  ''  l'^".nV°  ^"^"'  -^  thVKco'L'To^^^^^^^^^^ 
over  the  surface  which  had  been  shaved.     The  swelling  is  completed  bv  steenine  the 

aStherdy"^:" '''"'""  °^^^"^''^'^' "'^^^ 

In  the  East  the  following  processes  arc  pursued.     Entirely  white  shaereen  is  obtainpd 

kev' wheaTlnd  lfte"/^r  "  ''''''r  ^'k^^""'  ^«^^""^"  ''  -'^h  the  dough^LadV^^^^^^^^^ 
«^L      Si^     s?"^^  *  ^'°*^  washing  this  away  with  a  solution  of  alum.     The  strins  are 

TaTer  turlrwithTbTun'JrT' ''  ?T'^'  *!^^^^  '•'^•^^^^'  ^^^  --^^  <^-''-"  ^^  ho 
water  curried  with  a  blunt  knife,  and  afterwards  dried.     They  are  died  red  with  decoc 

l^on  oHMrsTl  Lt'r?  ^"^,^r" -ith  fine  copper  filings  Ld  sal  ammonracthe^ 
mnlfJ  inf/  if  fif^i  ^PPl^^d,  then  the  filings  being  strewed  upon  the  skin,  which 

must  be  rolled  up  and  loaded  with  weights  for  some  time ;  blue  is  given  with  indigo  auiJk. 
hme,  soda,  and  honey  j  and  black,  with  gaUs  and  copperas.  °  *  ^ 


fcjHEATHING  OF  SHU>S. 


595 


SHALE,  or  SLATE- CLAY,  is  an  important  stratiform  member  of  the  coal- 
measures.    See  PiTcoAL. 

SHAMOY  LEATHER  See  Leather. 
*  SHAWL  MANUFACTURE.  Shawls  were  originally  woven  in  the  heart  of  India, 
from  the  fine  silky  wool  of  the  Thibet  goat ;  and  the  most  precious  of  them  still  come 
from  Cashmere.  The  wool  of  which  these  articles  are  manufactured  consists  of  two  dis- 
tinct sorts,  called  wool  and  kemp.  The  wool  is  beautifully  rich  and  soft  to  the  touch, 
and  is  probably  superior  in  this  respect  to  the  finest  continental  lamb's  wool,  and  equal 
in  richness  to  the  Thibet  wool  It  is  also  divisible  into  qualities.  The  kemp  presents 
the  appearance  of  a  coarse  rough  hair,  such  as  is  avoided  by  the  manufacturer  in  all  pur- 
chases of  wools,  deteriorating  as  it  does  the  appearance  of  even  common  fabrics  by  its 
inferiority  and  harshness. 

The  two  wools  as  shorn  from  the  goat  are  closely  intermingled,  and  present  the  ap- 
pearance of  a  coarse  hairy  wool  of  a  very  low  character,  but  a  minute  inspection  shows 
that  part  of  it  is  of  a  very  fine  quality.  In  order  to  separate  this  fine  quality  from  the 
coarse,  it  is  necessary  to  do  so  fibre  by  fibre,  and  this  has  to  be  effected  entirely  by  hand, 
no  machinery  having  as  yet  been  applied  to  this  purpose.  The  process  is  both  difficult 
and  tedious,  one  person  not  being  able  to  separate  more  than  half  an  ounce  in  twelve  hours. 

After  the  separation  of  the  qualities  it  is  desirable  further  to  divide  it,  in  order  to 
make  a  warp  yarn  for  fabrics  like  the  shawls ;  but  this  was  impossible  in  the  present 
instance,  owing  to  the  small  quantity  produced,  otherwise  the  fabric  would  have  been 
much  finer.  In  the  dresses  this  result  has  been  achieved,  because  the  warp  is  of  silk, 
and  the  quantity  required  for  the  weft  was  therefore  not  so  great  in  proportion. 

The  specimen  of  coarse  cloth  in  the  Great  Exhibition  was  entirely  manufactured  of 
coarse  hairs  or  kemp  after  it  was  assorted  from  the  finer  material  of  the  wool  In  a  ge- 
neral way  this  is  considered  worthless. 

SHEATHING  OF  SHIPS.  For  this  purpose  many  different  metals  and  metalUc 
alloys  have  been  lately  proposed.  From  a  train  of  researches  which  I  made  for  an 
eminent  copper  company,  a  few  years  ago,  upon  various  specimens  of  sheathing  which 
had  been  exposed  upon  ships  during  many  voyages,  it  appeared  that  copper  containing 
a  minute,  but  definite,  proportion  of  tin,  was  by  far  the  most  durable. 

The  process  of  coppering  vessels,  which  has  of  late  years  been  generally  adopted,  in 
order  to  protect  their  bottoms  from  the  injurious  effects  of  insects  m  hot  countries,  and 
prevent  the  adherence  of  barnacles,  <fec.,  which  greatly  impede  the  progress  of  the  vessels, 
had  been  open  to  many  objections  ;  for  not  only  was  the  prime  cost  of  the  material  very 
great,  but  the  exjpense  of  rolling  it  into  sheets,  and  the  frequent  renewal  of  parts  which 
had  been  injured  during  the  voyage,  made  this  copper  covering  a  serious  item  in  the 
expenses  attendant  upon  fitting  out  ships. 

In  order  to  make  this  application  of  copper  still  more  general,  Sir  Humphry  Davy 
turned  his  attention  to  the  subject,  and  endeavoured  to  devise  some  method  of  counter- 
acting the  rapid  oxidation  which  took  place  on  its  exposure  to  the  sea  water,  as  it  was 
rare  for  the  copper  bottom  of  a  ship  to  last  longer  than  five  or  six  years.  It  struck  Sir 
H.  Davy  that  if  a  portion  of  zinc  were  applied  to  the  copper  it  would  counteract  the 
process  of  oxidation ;  and  a  vessel  sheathed  with  copper  and  zinc  plates  was  accordingly 
sent  a  voyage  to  a  distant  part  of  the  world,  from  whence  it  returned  perfectly  uninjured 
by  the  salt  water,  as  far  as  the  metal  was  concerned,  but  in  as  foul  a  state  as  i'f  there  had 
been  no  sheathing  upon  the  bottom  of  the  vessel.  The  presence  of  the  zinc  had  pre- 
vented the  oxidation  of  the  copper,  but  had  stopped  that  electric  action  which  was 
necessary  to  resist  the  marine  deposit  The  problem,  therefore,  still  remained  to  be 
solved,  whether  any  metallic  composition  could  be  found  for  the  sheathing  of  ships 
capable  of  preventing  the  bottom  from  fouling,  and  at  the  same  time  resisting  the  process 
of  oxidation.  To  the  solution  of  this  problem  Mr.  Muntz,  who  is  a  metal-roller  at 
Birmingham,  directed  his  attention,  and  commenced  a  series  of  experiments,  which 
resulted  in  his  taking  out  a  patent  in  1832.  This  invention  slowly,  but  steadily,  attracted 
the  notice  of  the  shipping  interest  of  the  country,  and  it  appeared  that  in  1834  in  the 
port  of  London  20  ships  were  sheathed  with  metal  prepared  by  Muntz's  patent  process. 
The  number  gradually  increased,  until,  in  1843,  there  were  in  the  same  port  257  vessels 
sheathed  with  the  new  composition,  of  which  17,947  cwt.  were  sold  in  the  last  mentioned 
year.  The  improved  metal-sheathing  was  a  mixture  of  copper  and  zinc,  which  was 
cheaper  than  copper,  more  easily  worked,  and  lasted  longer  than  the  pure  metal  before 
in  use.  In  the  specification  of  Mr.  Muntz's  patent,  the  nature  of  his  invention  is  thus 
described :— "  I  take  that  quality  of  copper  known  to  the  trade  by  the  appellation  of 
•  best  selected  copper,'  and  that  quality  of  zinc  known  in  England  aa  •  foreign  zinc,* 
and  melt  them  together  in  the  usual  manner,  in  any  proportions  between  50  per  cenu 
of  copper  to  60  per  cent,  of  zinc,  and  63  per  cent,  of  copper  to  87  per  cent,  of  zinc, 
both  of  which  extremes,  and  all  intermediate  proportions,  will  roll  at  a  red  heat ;  but,  as 
too  large  a  proportion  of  copper  increases  the  difficulty  of  working  the  metal,  and  too 


596 


SHOE-BLACKING. 


ii   .' 


i 


i 


hrge  a  proportion  of  zmc  renders  the  metal  too  hard  when  cold,  and  not  sufficientlv 
liable  to  oxidation,  I  prefer  the  alloy  to  consist  of  about  60  wr  cent  of  co,^  to  in 
per  cent  of  zinc."     It  was  proved  on  the  part  of  Mr  M^inf  J^  tw  ^^       •  *  S 

with  th«  frftHo  «f  o  i««*»i  Hii        ""•'"«  pari  oi  inr.  Muntz,  that  any  person  acquainted 

Tf  thfhiyenlLn  cXi^p/?n  ^L^^^^^-'JT^^  composition  from  the  description 

and  An^i^^  1843  ^oth^r  n«./  1'^"'^?*'''°'  ^^'^  ^PPeared.  that  between  February 
t^  a^S  700/  or  80or«S^  ^  Y  ?\^^  *  ^"^"i'Vy  *^^  sheathing,  amounting  in  valuJ 
w  aoout  700/.  or  800/.,  some   of  which  was  sold  by  them  in  J^vernool-   and  which. 

L°  ^"sf  Sef  ouTL^Z'at'^  ""^."'.-^^ ''''  s/me  proportbnTro^peTl^^^^^^^ 
^Ople^::^^^^^^^^^  -  ^^^  ^^t  aUoy  for  the%poae,  .iz- 

thf.^'fv,*^-^  '^^^!"''^  '*  "^^^  pleaded,  that  there  had  been  no  infringement  of  the  patent- 
tdlt  '^TX'''"  ^^?  °«*.°«^.  ^nd  that  Mr.  Muntz  was  not  the  fir^^d  true  inventor  * 
jnd  also  that  the  specification  was  bad  for  uncertainty,  <kc      Upon  thrfirst  ^in^-tha 

S'isoratrljoni^rlr-  -;-«f-^<^^-^  but  L  mainSof  defennasTtha? 
!li  oJiL  Collins  obtained  a  patent  for  a  composition  for  sheathing  shins  which  it 
W.wf  TK™  «".^«ta»t>*»y  the  same  invention  ks  that  which  the  plfintTclaTmed  M 

iWs"^^^^^^^^  ^'a:  *^«  y^"-  sheat?iing  (the  si'arhin'^ 

♦lloJ  !;  *   ^  consists  chiefly  of  zmc  and  copper.     The  compound  must  be  heated  and  in 
^t  state  rolled;  100  parts  of  copper  anS  80  of  zinc  afford  a  ^rd  com  posit  bn^^^^ 
^e  proportions  may  be  varied,  or  other  metallic  substances  added.^videTthe  proiertv 
of  bearing  the  mechanical  process,  when  added,  is  not  destroyed."  ^Ev  dence  was  Sfven 

S;  th:n  te'r  Aprif  mt  wi:'  «^«V'^Sr^  ^^^'^  °^^*^"^^  sheathing  m^ufXe" 
Sll^oi  *  ^  '  ^.'  ^^  "^^de  from  the  specificat  on  in  CoUins's  patent  alone  and 
several  witnesses  were  also  called  to  prove,  on  their  behalf,  that  a  comp^ositioo  or^^^^^ 

The  Lord  Chief  Justice,  before  proceeding  to  charge  the  iurr  told  them  fliAf  if  tt.^ 

^o'thffr"',  '[uT'"^  ""^  "'■"^^  °f  «"=  "idenceWoie^he  should  wh  to  t^ 
ttat  t,i,?^„^/i^*'  PTrr '  *""  "•  """"B  ''=«'»  the  eridence,  they  did  not  r^'re 
thel  w™1l T"  ''^^'»•.''^  <'\«^^  P"<»ed  to  call  their  attention  to  the  points  on  whWk 

the  ?nm^n?r  P  f  J^as  sufficiently  plain  and  intelligible  to  enable  other  peVsons  to  make 
nr^ni^P  "lu  ^'"'  ^^'""^  f.^  P**^"'  ^^d  been  granted.  His  Lordship  also Tve  h  T^ 
Son  w.;Tn  A^  "'•K '^v^^  l^^  ^"^^'"^  ^"  ^'^^  ^^^^«'  that  the  nature  of  tL  p?aS's  i^v^ 
«WpT  f  K  f,!''".^^^'^  *^"  *'^^"  «^  ^^^  patent,-"  An  improved  manuCture  of  metal 
gates  for  sheathmg  the  bottoms  of  ships  or  other  such  vessels ;"  that  neXr  "  Lst  selS 

S^a^comZi  •^°'' f  ^"  r'l'^r^  P^^^  «^  *^«  i"^^"*i«°.  ^hiih  consisted  in  th^  discovery 
no  morTtir  ^v  ^^eathmg  by  which  a  proper  degree  of  oxidation  was  obtabed  ^3 
andXf  'fli  •       "*-"^  ??^i  """^^  ^^  *  '^d  heat  was  not  claimed  as  part  of  the  invention 

SS^i,^^-    See  Lac,  and  Sealing-wax. 
SHOE-BLACKING. 

Ivory  black  -  -  .  , 

Treacle  -  .  .  ^ 

Vinegar  -  .  .  " 

Oil  of  vitriol  -  .  . 

Sperm  oil  .  .  .  * 

To  be  mixed  in  the  above  order  in  a  mortar 

Ivory  black    .  ^  ^^-ckir^  (paste). 

Oil  of  vitriol   -  ,  . 

Treacle  -  •  -  I  " 

Sweet  oil        -  .  .  * 

Vinegar         .  .  J  J  " 

Sulphate  of  iron  -  .  "  ' 

Gumarabic    -      <Di«^l^^i°  ^  water  6  oz.) 


SILICA. 


597 


8  oz. 

6  oz. 
24  oz. 

1  oz. 
10  dr. 


21ba. 
4  ox. 
lib. 

4  oz. 

5  oz. 
i  oz. 


(by  weight) 


1  oz.  Mix. 


SIENITE  is  a  granular  aggregated  compound  rock,  consisting  of  feldspar  and  horn- 
blende, sometimes  mixed  with  a  little  quartz  and  mica.  The  hornblende  is  the  charac- 
teristic ingredient,  and  serves  to  distinguish  sienite  from  granite,  with  which  it  has  >*'»a 
sometimes  confounded ;  though  the  feldspar,  which  is  generally  red,  is  the  more  abu.i- 
dant  constituent.  The  Egj'ptian  sienite,  containing  but  little  hornblende,  with  a  good 
deal  of  quartz  and  mica,  approaches  most  nearly  to  granite.  It  is  equally  metalliferoui 
with  porphyry ;  in  the  island  of  Cyprus,  it  is  rich  in  copper ;  and  in  Hungary,  it  contains 
many  valuable  gold  and  silver  mines. 

Sienite  forms  a  considerable  part  of  the  Criffle,  a  hill  in  Galloway.  It  takes  its  name 
from  the  city  of -Syene,  in  the  Thebaid,  near  the  cataracts  of  the  Nile,  where  this 
rock  abounds.  It  is  an  excellent  building-stone,  and  was  imported  in  large  quantities 
from  Egypt  by  the  Romans,  for  the  architectural  and  statuary  decorations  of  theii 
capital. 

SILESIAN  LINENS.  The  manufacture  of  linens  is  carried  on  in  Bohemia,  Moravia, 
Silesia,  and  Galicia  on  the  largest  scale.  Of  the  entire  production  about  five-twelfths  are 
brought  into  the  market,  and  of  this  quantity  the  bulk  must  be  of  domestic  manufacture, 
since  few  great  linen  manufactories  exist  in  Austria.  Among  the  linen  fabrics,  table- 
cloths and  napkins,  veils,  cambrics,  dimities,  twills,  and  drills  are  important  articles.  Ii^ 
the  next  rank  we  must  place  the  manufacture  of  thread,  especially  in  Bohemia,  Moravia, 
and  Lombardy.  The  tape  manufacture  is  of  less  consequence ;  and  as  to  the  business  of 
dying  and  printing,  that  has  been  almost  entirely  absorbed  by  the  cotton  manufacture, 
and  is  now  m  requisition  for  thread  and  handkerchiefs  only. 

As  the  loss  resulting  from  the  processes  of  weaving,  bleaching,  <tc.  is  estimated  at 
about  10  per  cent.,  the  net  aggregate  of  these  manufactures  of  linen,  thread,  <tc.,  may  be 
assumed  at,  say,  1,037,000  cwt.;  of  which  quantity  about  450,000  cwt.  come  into  the 
market,  the  rest  being  absorbed  by  domestic  consumption.  Since,  upon  an  average  of  the 
five  years  from  1843  to  1847,  there  appear  to  have  been  imported  from  abroad  only  242 
cwt.,  whereas  the  average  of  exports  for  the  same  period  shows  42,609  cwt.,  it  follows 
that  there  remained  for  home  consumption  about  1,000,000  cwt  Thus,  on  a  population 
of  38,000.000  of  persons  about  2^  lbs.  would  fall  to  the  share  of  each ;  but  this  estimate 
falls  much  below  the  truth,  when  we  consider  that  the  national  costume  in  Hungary  and 
Galicia  requires  more  than  double  the  quantity  we  have  allowed  for.  In  fact  the  crop 
of  flax  is  estimated  to  be  10  per  cent,  higher  than  is  given  in  the  official  reports ;  but  the 

•  consumption  of  even  3  lbs.  per  head,  which  would  thus  result,  is  yet  smaller  than  in 
reality  it  must  be.  In  the  imperial  army  the  quantity  used  up  annually  by  each  man 
averages  more  than  7  lbs. 

In  the  above  statistics  of  the  manufacture  of  linen  goods  no  allowance  has  been  made 
for  the  extensive  production  of  rope  work  and  the  like. 

SIliICA  and  SILICON".  (StVice,  si/tcmm,  Fr. ;  Kieselerde,  kieselj  Germ.)  Silica  was 
till  lately  ranked  among  the  earths  proper ;  but  since  the  researches  of  Davy  and  Ber- 
zeliiis,  it  has  been  transferred  to  the  chemical  class  of  acids.  It  constitutes  the  principal 
portion  of  most  of  the  hard  stones  and  minerals  which  compose  the  crust  of  the  globe ; 
occurring  nearly  pure  in  rock  crystal,  quartz,  agate,  calcedony,  flint,  &c.  Silica  or 
silicic  acid  may  be  obtained  perfectly  pure,  and  also  in  the  finest  state  of  comminution, 
by  taking  the  precipitate  formed  by  passing  silicated  fluoric  gas  through  water,  filter 
ing,  washing,  and  igniting  it,  to  expel  the  last  traces  of  the  fluoride  of  silicon.  The 
powder  thus  obtained  is  so  light  as  to  be  blown  away  with  the  least  breath  of  air.  Silica 
may  be  more  conveniently  procured,  however,  by  fusing  ground  flint  with  four  times  its 
wei'-'ht  of  a  mixture,  in  equal  parts,  of  dry  carbonate  of  potassa  and  carbonate  of  soda,  ia 
a  platinum  or  silver  crucible.  The  alkaline  carbonates  should  be  first  fused,  and  the  flint 
powder  sprinkled  into  the  liquid,  as  long  as  it  dissolves  with  effervescence.  The  mass  is 
to  be  then  allowed  to  cool,  dissolved  in  dilute  muriatic  acid;  the  solution  is  to  be  filtered, 
and  evaporated  to  dryness ;  the  dry  crust  is  to  be  pulverized,  digested  for  two  hours  with 
a  little  muriatic  acid,  to  remove  any  iron  and  alumina  that  may  be  present,  next  washed 

♦  with  hot  water,  drained,  dried,  and  ignited. 

The  above  silicate  of  potassa  and  soda  is  the  compound  called  soluble  glass,  which 
applied  in  solution  to  the  surface  of  wood,  calico,  paper,  &c.,  renders  them  unsusceptible 
of  taking  fire  on  the  contact  of  an  ignited  body. 

Silica,  as  thus  prepared,  is  a  white  powder,  rough  to  the  touch,  gritty  between  the 
teeth,  absolutely  iasoluble  in  water,  acids,  and  most  liquids.  Its  specific  gravity  ia 
2*66.  It  cannot  be  fused  by  the  most  intense  heat  of  our  furnaces,  but  at  the  flame  ol 
the  oxy-hydrogen  blowpipe  it  melts  into  a  limpid  colorless  glass.  By  peculiar  chemi- 
cal methods,  an  aqueous  solution  of  it  may  be  made  artificially,  similar  to  what  nature 
presents  us  with  in  many  thermal  springs,  as  in  those  of  Reikum  and  of  Geyser  in  Ice- 
land, and  of  most  mineral  waters,  in  minute  quantity.  There  is  no  acid  except  the  flu- 
oric which  can  directly  dissolve  dry  or  calcined  silica.  Silica  is  composed  of  48  04  silicoi^ 
and  51*96  oxygen. 


Mi    ;i  I 


ill     J 


i 


^1 

I' 


!:   I 


■''I' 


f! 


!^8 


SILK  MANUFACTURE. 


SILICATES  »re  compoands  of  silicic  acid  (■«ilI<.«N  »:<i.  .1.    v  • 

•esia,  polassa,  soda,  fccV  Thev  const  h«^Vl,;  i     .'  '^  ^"^^  alumina,  lime,  magL 

.15  which  incr'us.  th'eTerresfriaT.Zf  ThLs  c4^?,l^  number  by  far  of  the  hard  mine?, 
•nd  leucite,  are  silicates  of  a"un,ina  and  P«tas4'^  a  bite'.n'S  »''''?"' ""^"'"T"'  ^'^T' 
•niina  and  soda:  stilbite  orehnite  n,.J;n,.Ti;  *"".**""  ""a'cme.  are  silicates  of  al- 
Ces  of  alumina  ^ndZe'.'^Jrrysomr.TeM^^^^^^  loarmaline,  mica,  &c.,  are  sili- 

«f  magnesia;  au-ite  and  hornb7ent'\rl  S'esTf Tto"^"^^  meerschanm,  are  silicate. 

.ufr!;'r'Thrpr:^^t1r.rcoif  ^^^^^^^  ■'"  ^'"-eO 

eilt  solution,  which  ircimnosed^f  r„rr  J-  1T°,  •"  "  '"'''»•» '"'^"'  "'""  «  ^«"  »f  ««' 
ever,  be  removed  by  a  erardeal  of  washini      TbT'.t     f"T  .™'  ^■'"  ""J.  •■»»- 

«afbfdi^i^^'^--T™„chi-r:';bet J^^t.^^^^^^  r-^nSt^r?  ^"^ 

P^a^Cnyl'e'^S.trr,^^^^^^^^^ 

fctt'L^^s  aJi'^liVfal^rr^ea'Jh  ^f  1^F¥^     ''' "^^  ^^"'^^ 

^^::i.  of  tt^  ti!??^  »H?i"7-^^^^^  t;^,'=.i;7  s'j 

u  ui  uieir  weigni.     J^ach  ultimate  filament  measures  about      1_  of  an  ineh 
In  average  fine  silk,  and  the  pair  measures  of  course  fully      i      of  an  in^  In  Z  r« w 

,  The  specjhc  gravity  of  silk  is  J -300,  water  bein-  l-OOO      Tt  f«  hv  A,r  ti, 

rv;h/^e^ir  !tr/ernuri"^rfe  vf^^^^^^^^^^ 

™r..es  of  sil.  are  perfectly  wJiL^rthf  gt^^clr^ ISv^s^tT;  .o^d^S 

The  production  of  silk  was  unknown    in  EuronP  iJli  i>,o  ^:^t\, 
Bonks,  who  brought  some  eggs  of  the  silkwormTom  C  ina  or  IndiaToS,,!:  f"  T 
were  encouraged  to  breed  the  insect  and  ■.nli,„iT-.  mjia  to  Constantinople, 

«ian^  Several'  silk  man^Jactu'rer^el^et  c»  "q'nen  e  eT.S'e  '  i^Afh^eSr  x/r '" " 
and  Corinth,  not  only  for  rearing  the  worm  «pon  mulb^rnMeafes  bnt  for  tn-L?^ 

riches  from  the  trade  J^urope  Miin  siJk  goods,  and  derived  great 

^^^^^zf^^!^:i.:,  ^\rs"etnnd"  '»'tv"^ 

Mopnd-s:^;iL-d^-;xr-^^^^^^^^^ 

=prst-n-:v^^Xe-ii:a^^^^^^^^^ 

l^J.1  ,'•^^^^"°"«'  '»  r''*^"'^  "'^■»  -"'"  ^^^y  of  the  southern  ZyTnces  of  Fr.n» 

t^Hr„iyTr^d'"si;i:^bt"^vi^:e'"S^^^^^ 

•objects  to  p,ant'^lK;?rtT;VurhM<JXMS™lhe%ZT'^^^^^^^^^ 

not  seem  to  be  well  adapted  for  this  soppipq  nf  V.,  k   ^         project.     This  country  does 

valence  of  blighting  eaTtCrndrdu  "ng'  rmonf^^^^^^^^^  '^.'^*^  T**  ^''' 

require  a  plentiful  sipply  of  mulbern-rieave.     Thtl  ^^l'^ ^""^  ^^T' ^''^n  t»>e  worms 

«ade  great  prosress^duHngThark?ni'rpe;ceft.f  a^J"^^^^^^^^  '^''^^  ^^"^h  ^'""'^''^ 
become  so  considerable  in  London    that  !?.[  I  ?^^  ^"  ^^^9  il  had 

were  formed  into  a  public  corporat^n  So  earlv  a.  Jfi'jT'  "^  '^  'I'lA''^  ^"^"'^ 
The  revocation  of  the  edict  of  Nantes  inUS^cnJr^^A^^'  '""^^''•'1  ^?.'^^  ^"••'°"^- 
the  increase  of  the  En-lish  .ik  trade  W  til   '  ^^'^^^'^^^.^  »"  *  remarkable  manner  to 


SILK  MANUFACTURE. 


599 


afterwards,  in  the  year  1730,  the  English  silk  goods  bore  a  higher  price  in  Italy  thaa 
those  made  by  the  Italians,  according  to  the  testimony  of  Keysler. 

Till  the  year  1826,  however,  our  silk  manufactures  in  general  labored  under  very 
grievous  fiscal  burdcRS.  Foreign  organzine,  or  twisted  raw  silk,  paid  an  import  duty  of 
14a.  7|i.  per  pound  ;  Raw  Bengal  silk,  4«. ;  and  that  from  other  places,  55.  7|rf.  Mr. 
Huskisson  introduced  a  bill  at  that  time,  reducing  the  duty  on  organzine  to  5*.,  and  the 
duty  on  other  raw  silk  to  3d.  per  pound.  The  total  prohibition  of  the  import  of  French 
manufactured  silks,  which  gave  rise  to  so  much  contraband  trade,  was  also  converted 
into  a  duty  of  30  per  cent,  ad  valorem.  During  the  reign  of  the  prohibitory  system, 
when  our  silk  weavers  had  no  variety  of  patterns  to  imitate,  and  no  adequate  stimulus 
to  excel,  on  account  of  the  monopoly  which  they  possessed  in  the  home  market,  the 
inferiority  of  their  productions  was  a  subject  of  constant  pride  and  congratulation 
among  the  Lyonnais;  and  accordingly  the  English  could  not  stand  their  competition 
any  where.  At  that  time,  the  disadvantage  on  English  silk  goods,  compared  to  French, 
was  estimated  in  foreign  markets  at  40  per  cent. ;  of  late  years  it  certainly  does  not  ex- 
ceed 20,  notwithstanding  the  many  peculiar  facilities  which  France  enjoys  for  this  her 
favorite  staple. 

The  silkworm,  called  by  entomologists  Phaloena  bombyx  nzon,  is,  like  its  kindred 
species,  subject  to  four  metamorphoses.  The  egg,  fostered  by  the  gen.'/U  warmth  of 
spring,  sends  forth  a  caterpillar,  which,  in  its  progressive  enlargement,  ca&ts  its  skin 
either  three  or  four  times,  according  to  the  variety  of  the  insect.  Having  acquired  its 
full  size  in  the  course  of  25  or  30  days,  and  ceasing  to  eat  during  the  remainder 
of  its  life,  it  begins  to  discharge  a  viscid  secretion,  in  the  form  c'  pulpy  twin 
filaments,  from  its  nose,  which  harden  in  the  air.  These  threads  are  instinctively 
coiled  into  an  ovoid  nest  round  itself,  called  a  cocoon,  which  serves  as  a  defence  against 
living  enemies  and  changes  of  temperature.  Here  it  soon  changes  into  the  chrvsalis  or 
nymph  state,  in  which  it  lies  swaddled,  as  it  were,  for  about  15  or  20  days.  Then  it 
bursts  its  cerements,  and  comes  forth  furnished  with  appropriate  wings,  antennae,  and 
feet,  for  living  in  its  new  element,  the  atmosphere.  The  male  and  the  female  moths 
couple  together  at  this  time,  and  terminate  their  union  by  a  speedy  death,  their  whole 
existence  being  limited  to  two  months.  The  cocoons  are  completely  formed  in  the  course 
of  three  or  four  days ;  the  finest  being  reserved  as  seed  worms.  From  these  cocoons, 
after  an  interval  of  18  or  20  days,  the  moth  makes  its  appearance,  perforating  its  tomb 
by  knocking  with  its  head  against  one  end  of  the  cocoon,  after  softening  it  with  saliva, 
and  thus  rendering  the  filaments  more  easily  torn  asunder  by  its  claws.  Such  moths  or 
aurelias  are  collected  and  placed  upon  a  piece  of  soft  cloth,  where  they  couple  and  lay 
their  eggs. 

The  eggs,  or  grains,  as  they  are  usually  termed,  are  enveloped  in  a  liquid  which 
causes  them  to  adhere  to  the  piece  of  cloth  or  paper  on  which  the  female  lays  them. 
From  this  glue  they  are  readily  freed,  by  dipping  them  in  cold  water,  and  wiping  them 
dry.  They  are  best  preserved  in  the  ovum  state  at  a  temperature  of  about  55°  F.  If 
the  heat  of  spring  advances  rapidly  in  April,  it  must  not  be  suffered  to  act  on  the  eggs, 
otherwise  it  might  hatch  the  caterpillars  long  before  the  mulberry  has  sent  forth  its  leaves 
to  nourish  them.  Another  reason  for  keeping  back  their  incubation  is,  that  they  may  be 
hatched  together  in  large  broods,  and  not  by  small  numbers  in  succession.  The  eggs 
are  made  up  into  small  packets,  of  an  ounce,  or  somewhat  more,  which  in  the  south  of 
France  are  generally  attached  to  the  girdles  of  the  women  during  the  day,  and  placed 
under  their  pillows  at  night.  They  are,  of  course,  carefully  examined  from  lime  to  time. 
In  large  establishments,  they  are  placed  in  an  appropriate  stove-room,  where  they  are 
exposed  to  a  temperature  gradually  increased  till  it  reaches  the  86th  degree  of  Fahren- 
heit's scale,  which  term  it  must  not  exceed.  Aided  by  this  heat,  nature  completes  her 
mysterious  work  of  incubation  in  eight  or  ten  days.  The  teeming  eggs  are  now  covered 
with  a  sheet  of  paper  pierced  with  numerous  holes,  about  one  twelfth  of  an  inch  in 
diameter.  Through  these  apertures  the  new-hatched  worms  creep  upwards  instinctively, 
to  get  at  the  tender  mulberry  leaves  strewed  over  the  paper. 

The  nursery  where  the  worms  are  reared  is  called  by  the  French  a  magnanilre ;  it 
ought  to  be  a  well-aired  chamber,  free  from  damp,  excess  of  cold  or  heat,  rats,  and  other 
vermin.  It  should  be  ventilated  occasionally,  to  purify  the  atmosphere  from  the 
noisome  emanations  produced  by  the  excrements  of  the  caterpillars  and  the  decayed 
caves.  The  scaffolding  of  the  wicker-work  shelves  should  be  substantial ;  and  they 
snould  be  from  15  to  18  inches  apart.  A  separate  small  apartment  should  be  allotted 
to  the  sickly  worms.  Immediately  before  each  moulting,  the  appetite  of  the  worms 
begins  to  flag ;  it  ceases  altogether  at  that  period  of  cutaneous  metamorphosis,  but 
revives  speedily  after  the  skin  is  fairly  cast,  because  the  internal  parts  of  the 
animal  are  thereby  allowed  freely  to  develop  themselves.  At  the  end  of  the  second 
age,  the  worms  are  half  an  inch  long ;  and  then  should  be  transferred  from  the  small 
room  in  which  they  were  first  hatched,  into  the  proper  apartment  where  they  are  to 


600 


SILK  MANUFACTURE. 


i' 


■  :1 


!>:. 


4i 


•be  brouj,ht  to  maturity  and  set  to  snin  their  hall«      n«  «-      •         ^    ^ 
abode,  t].ey  mast  be  well  cleansed  froT  the  litter  Ldu^^^^  ^^^ 

supplied  with  an  abundance  of  food  e^ery  six  hou  s  1  T  ^'^^  ""^  ^^^  ^'^^^^'  *»« 
bed,  a  piece  of  network  being  laid  over  the  4^0^  n l  es  ZT"''''''  /"  l^^^*"^  ^^^" 
worms  will  creep  up  over  them  •  whpn  tVo«  v  P;*^^%«»d  covered  with  leaves,  the 

The  litter,  as  well  L  [he  Sv'  ZrZ  tl^^L^  transferred  in  a  body  upon  the'net! 

.single  hUhy  one""  AfleTthl  rr^^^^^^^^ 

they  are  now  exceedin^^lv  voracioiiQ    »nA  1,L   ^*  t        f  *^  ^"**^^  ^^^^^s;  because 

diet.  The  exposure  of  chloride  of  limP  T.-H  t'h-  ^'  ^"^«^^»^"«Iy  stinted  in  their 
magnanrere,  has  been  found  useful  L  rnteTactit  tlTe  tS  ^^""''Vl  ''''  ^'^  ^^  ^^« 
pears^of  an  epidemic  disease  ^on^l^^S^^^  ^^ 

«nh^^l^  ^^K^  """f  "^^^  '"  *»•'  «'">"  in  "hf  fourth  or  fifth  ."e  aereeahlv  .„  .k 

work  ,vhieh  cons.i.u.es  ,he  ij7^  Sk  fo^e  Xg  andl^i  *  r."''  "  ""'"  ""*"  "«'• 

Jt:rXe'':s■l^ht*'r:h„r  r  '^  -Vi  '°"?^  •■-  -^  -^^^^  -* 

«.n.e  out,  .he  filaments  at  0"^  e^5  woS  d  be  cut  Slh  Yn^l  r^', '"  ^^  '"'''"^'  «' 
Talue.  It  is  therefore  nece««arv  to  extinlnith  ,ki  rr  r  fu  '^"*  '*"'  "'""'«'  »"  'heir 
done  either  by  exposing  he~cocoo^"fo  'a  ftwd«s  to  su°n,htf/r'','  "^  ''T'  *"''"  » 
OTen,  or  in  the  steam  of  boiling  water     A  W  of  202"  p'  Z  '?''""°/  "■'"■ '"  »  ""o' 

porpose  and  it  may  be  best  admin^ed  b^nginAi^casesS  w^h^fr'"  ""» 
into  water  heated  to  that  pitch  i'^""S"»o  iin  cases  njled  with  the  cocoons 

J^X"»C'a'rhe±   l^^^^^^  ^^ -ks  from 

iazardous  period  in  the  prSsof  breedintfhe  w^ms  I  ».  fr.V^^'^";?"'-    T*'  »»«« 
for  upon  the  sixth  day  of  the  ihirH  »"„  -^i  .if  *"'™«' '» /'  "he  third  and  fourth  moulting  j 

..t  nothing  a.  all.    On  the  first  dayWe  fourth?!  n ''  "'""  '"°"'-"''  ""^^  '"  "^"'^ 
ounce  of  eggs  will,  accordin  "to  BnnJll  ^  '  "'*  ™™«  proceeding  from  one 

«.d  a  quartfr  of  llberry  lelve^^^  firs.'T ZT,?"  "'"!!«'  '"^ty-thVee  pounds 

two  pounds  J    and  on  the  sSh  dav  of    h!  1  ^?'^"'  "«^'  ""y  "'"  consume  forty, 

dty,  devour  ng  no  less  than  223  i^uLIf       T' i*"^  acquire  their  maximum  vori, 

SV"'  ™  '"^  '-'^  2"y  0^'-'^  a1e%heXf„L'ri;Xr^:dT"''^        "- 

JLtte^:^e:3];ii^''97ee5^%r*';xs'mtffrd'J^^^ 

they  produce.  general,  the  more  food  they  consume,  the  more  silk  will 

BulT;i'"fo'u™  X.^'ilZZl't'^'''?-'''  I''''' '  ^'^  ^«  P^-^ed  out  of  the 
increasing  crop  oHeaves  til  'the  weniith  if  !'Tf  '"  l^'  ^^^  y^^'''  «"d  affords  an 
according^to  iVs  ina.^hud  a^d  mLe  ^f  c'-ltfv^^^^^^^^^^^  oTe  V"''  ^^',7^^-  ^^  ^«^^^«' 
worth  in  France  about  2Krancs     it  renuire^^^^^^  ounce  of  silkworm  eggs  is 

15  cwts.  of  mulberry  leaverXch  co.TZ  an  «vt  development  into  cocoons  about 
reason.  One  ounS  of  Ssls  calcu  ated  as  ?  hlv.'^'  '/?"''  ^''  '^''  ^"  *  ^^^«^*^^« 
poundsofcocoons,of  the  v^ueof  1  fr  5^^^^^^  '5  ^'"^""^  ^'^°^  ««  t°  ^00 

About  8  pounds  of  reeled  raw  ^Ik  wo^fh  18  f^anof'  ^*'""^.' ""'  ^^5  francs  in  whole. 
100  pounds  of  cocoons.  '  ^'^''  *  P^""^'  ^^^  ^^lai'^ed  from  these 

Jo^'^Sr^;^^^^^^^^^ 

tram  ,s  made  usually  from  inferior  si^krand  irvery  .lithifvCi^tS '•  "'^^^^^^      ^^^^^^^  > 

spread  more,  and  cover  better  in  the  weft    tt^ Zrhn,.      ^      '^^"'^  *."  ^"""^^^  ^^^^  it  may 

•ilk,  which  is  carded  and  spun  1  ke  Totton     Orln^     '  T''''^  °^^^^  ^^'""'^^^  t^^o^^eJ 

to  30  twin  filaments  of  the  worm  •   the^rmePrr'"^  ^""^  ''vf^^  '"^^  ^^^^'^'^  ^''O'"  3 

filaments  being  fipst  twis  ed  Tn  one  direction  Id  ff''"'  *  ^""i*^"  ^^^^^'  *^«  component 

the  latter  receives  merira  sULsTng^t^i^^^^  the  compound  thread  in  theop^c^ite, 

ishes  in  thickness  and  slren-th    from  Ihi       ^    ^^9  1""'"  ^^^""^"t  gradually  dimin* 

begins  its  work  in  a  state  7v^or  Tthl  J«t     '%*'^  the  cocoon,  where  the  animal 

biJity  and  exhaustion  Tbecau.e  f  cin  receivp  n^'f  ""^T  "  ^^'^"^  ^^>  ^"  *  ^^^ate  of  de- 

to  spin  by  spouting  forth  iSslk^ubstinceTh/w'  I"^^  '^'  "^°'"""'  ^^  ^'^  »>^Si»««8 

attenuation,  and  introduces  tbe^lrnJ^^elt^^f^te^rorr^^^^^^^^ 


SILK  MANUFACTURE. 


601 


Imnination  of  others.  The  quality  of  raw  silk  depends,  therefore,  very  much  upon  the 
skill  and  care  bestowed  upon  its  filature.  The  soi^lest  and  purest  water  should  be  used 
in  the  cocoon  kettle. 

The  quality  of  the  raw  silk  is  determined  by  first  winding  off  400  ells  of  it,  equal  to 
475  metres,  round  a  drum  one  ell  in  circumference,  and  then  weighing  that  length* 
The  weight  is  expressed  in  grains,  24  of  which  constitute  one  denier ;  24  deniers  con- 
stitute one  ounce;  and  16  ounces  make  one  pound,  poids  de  inarc.  This  is  the  Lyons 
rule  for  valuing  silk.  The  weight  of  a  thread  of  raw  silk  400  ells  long,  is  two  grains  and 
«  half,  when  five  twin  filaments  have  been  reeled  and  associated  together. 

Raw  silk  is  so  absorbent  of  moisture,  that  it  may  be  increased  ten  per  cent,  in  weight 
by  this  means.  This  property  has  led  to  falsifications;  which  are  detected  by  enclosing 
weighed  portions  of  the  suspecte<l  silk  in  a  wire-cloth  cage,  and  exposing  it  to  a  stove-heat 
of  about  78°  F.  for  24  hours,  with  a  current  of  air.  The  loss  of  weight  which  it  thereby 
undergoes,  demonstrates  the  amount  of  the  fraud.  There  is  an  office  in  Lyons  called 
the  Condition^  where  this  assay  is  made,  and  by  the  report  of  which  the  silk  is  bought 
and  sold.  The  law  in  France  requires,  that  all  the  silk  tried  by  the  Condition  must  be 
worked  up  into  fabrics  in  that  country. 

In  the  Journal  of  the  Asiatic  Society  of  Bengal,  for  January,  1837,  there  are  two 
very  valuable  papers  upon  silkworms ;  the  first,  upon  those  of  Assam,  by  Mr.  Thomas 
Hugon,  stationed  at  Nowgong ;  the  second  by  Dr.  Heifer,  upon  those  which  are  indi- 
genous to  India.  Besides  the  Bombyx  rnori,  the  Doctor  enumerates  the  following 
seven  species,  formerly  unknown  :  —  1.  The  wi'ji  silkworm  of  the  central  provinces,  a 
moth  not  larger  than  the  Bombyx  mori.  2.  The  Joree  silkworm  of  Assam,  Bombyx 
religiosce,  which  spins  a  cocoon  of  a  fine  filament,  with  much  lustre.  It  lives  upon  the 
pipul  tree  (^Ficus  religiosa)^  which  abounds  in  India,  and  ought  therefore  to  be  turned 
to  account  in  breeding  this  valuable  moth.  3.  Satumia  silhetica,  which  inhaUv<s  the 
cassia   mountains  in   Silhet  and  Dacca,  where  its  large  cocoons  are  spun   into  silk. 

4.  A  still  larger  Satumia^  one  of  the  greatest  moths  in  existence,  measuring  ten  inches 
from  the  one  end  of  the  wing  to  the  other ;   observed  by  Mr.  Grant,  in  Chirra  punjee. 

5.  Satumia  paphia,  or  the  Tusseh  silkworm,  is  the  most  common  of  the  native  species, 
and  furnishes  the  cloth  usually  worn  by  Europeans  in  India.  It  has  not  hitherto  been 
domesticated,  but  millions  of  its  cocoons  are  annually  collected  in  the  jungles,  and 
brought  to  the  silk  factories  near  Calcutta  and  Bhagelpur.  It  feeds  most  commonly 
on  the  hair-tree  (^Zizyphus  jujuba'),  but  it  prefers  the  Terminalia  alatOj  or  Assam  tree, 
and  the  Bombax  heptaphyltum.  It  is  called  Koutkuri  moogay  in  Assam.  6.  Another 
Satumia^  from  the  neighborhood  of  Comercolly.  7.  Satumia  assamensis,  with  a  cocoon 
of  a  yellow-brown  color,  different  from  all  others,  called  moogay  in  Assam ;  which, 
although  it  can  be  reared  in  houses,  thrives  best  in  the  open  air  upon  trees,  of  which 
seven  different  kinds  afford  it  food.  The  Mazankoory  mooga,  which  feeds  on  the  Ada- 
koory  tree,  produces  a  fine  silk,  which  is  nearly  white,  and  fetches  50  per  cent,  more 
than  the  fawn-colored.  The  trees  of  the  first  year's  growth  produce  by  far  the  most 
valuable  cocoons.  The  mooga  which  inhabits  the  soom-tree,  is  found  principally  in  the 
forests  of  the  plains,  and  in  the  villages.  The  tree  grows  to  a  large  size,  and  yields 
three  crops  of  leaves  in  the  year.  The  silk  is  of  a  light  fawn  color,  and  ranks  next 
in  value  to  the  Mazankoory.  There  are  generally  five  breeds  of  mooga  worms  in  the 
year ;  1.  in  January  and  February ;  2.  in  May  and  June  ;  3,  in  June  and  July;  4.  in 
August  and  September ;  5.  in  October  and  November  ;  the  first  and  last  being  the  most 
valuable. 

The  Assamese  select  for  breeding,  such  cocoons  only  as  have  been  begun  to  be 
formed  in  the  largest  number  on  the  same  day,  usually  the  second  or  third  after  the 
commencement ;  those  which  contain  males  being  distinguishable  by  a  more  pointed 
end.  They  are  put  in  a  closed  basket  suspended  from  the  roof;  the  moths,  as  they 
come  forth,  having  room  to  move  about,  afler  a  day,  the  females  (known  only  by  their 
large  body)  are  taken  out,  and  tied  to  small  wisps  of  thatching-straw,  selected  always 
from  over  the  hearth,  its  darkened  color  being  thought  more  acceptable  to  the  insect. 
If  out  of  a  batch,  there  should  be  but  few  males,  the  wisps  with  the  females  tied  to 
them  are  exposed  outside  at  night ;  and  the  males  thrown  away  in  the  neighborhood 
find  their  way  to  them.  These  wisps  are  hung  upon  a  string  tied  across  the  roof,  to 
keep  them  from  vermin.  The  eggs  laid  afler  the  first  three  days  are  said  to  produce 
weak  worms.  The  wisps  are  taken  out  morning  and  evening,  and  exposed  to  the  sun- 
shine, and  in  ten  days  afler  being  laid,  a  few  of  them  are  hatched.  The  wisps  being 
then  hung  up  to  the  tree,  the  young  worms  find  their  way  to  the  leaves.  The  ants, 
whose  bite  is  fatal  to  the  worm  in  its  early  stages,  are  destroyed  by  rubbing  the  trunk 
of  the  tree  with  molasses,  and  tying  dead  fish  and  toads  to  it,  to  attract  these  rapacious 
insects  in  large  numbers,  when  they  are  destroyed  with  fire ;  a  process  which  needs  to  be 
repeated  several  times.  The  ground  under  the  trees  is  also  well  cleared,  to  render  it  easy 
lo  pick  up  and  replace  the  worms  which  fall  down.     They  are  prevented  from  coming  to 


*!||t 


U 


602 


SILK  MANUFACTURE. 


the  ground  by  tying  fresh  plantain-leaves  round  the  trunk,  over  whose  ^linnerv  ^inrfliM 
they  cannot  crawl;  and  they  are  transferred  from  exhausted  treLTofrLhZs  on  b^ 
boo  platters  tied  to  long  poles.  The  worms  require  to  be  constantlv  wntrh^H^n^^ 
tected  from  the  depredations  of  both  day  and  nig'ht  birds%s  ^XTrl  iTothe "^^^^^ 
During  their  moultmgs,  they  remain  on  the  branches  ;  but  when  about  be"  in mW  tn^ln' 

L'^Z'  'T\'''  '"'^  '^^^^^^"^  ^^^PP^  ^y  the  planta?ni:^^s;are^  he  e^^^^ 
m  baskets,  which  are  afterwards  put  under  bunches  of  dry  leaves,  suspended  from  the 
roof,  into  which  the  worms  crawl,  and  form  their  cocoons-several  befn"^Lt-»rTd  to 
pther :  this  accident,  due  to  the  practice  of  crowding  the  worms  to^er^whT^^^^ 
injudicious,  rendering  it  impossible  to  wind  ofl*  their  silk  in  continuous  t^rerds  as  in  the 
filatures  of  Italy,  France,  and  even  Bengal.    The  silk  is,  therefore,  spun  like  fl^x  instead 

?or  thTL^'^r"".^  '"  n^'  ^^""^^^'^-     ^^''  ^^"^  ^^y'  '^^  proper'l.ocoons  ar^^ekct^ 

fin  M  7n  /'  ^''^v'  -^^  ^^^  '^'^  ^'^  ""'^"'^-    "^'^e  tot^  duraUon  of  a  breed  varfes  from 
60  to  70  days ;  divided  into  the  following  periods :  — 


Four  moultings,  with  one  day's  illness  attending  each 

From  fourth  moulting  to  beginning  of  cocoon 

In.  the  cocoon  20,  as  a  moth  6,  hatching  of  eggs  10 


20 
10 
36 

66 


On  being  tapped  with  the  finger,  the  body  renders  a  hollow  sound :  the  quality  of  which 
cearedTeedin'J     ''  '"'  '""'  ''"'^  '''  "'^"^  '''''''''  «"  ^^«  tree! o? frSir  haJlng 

As  the  chrysalis  is  not  soon  killed  by  exposure  to  the  sun,  the  cocoons  are  put  on 
stages,  covered  up  with  leaves,  and  exposed  to  the  hot  air  from  grass  burned  under  them" 
they  are  next  boiled  for  about  an  hour  in  a  solution  of  the  potash,  made  from  ?nc?nerat°d 

¥hrfln  «l'  •  ^'"  '"^"'^  T^r^^.  ^^'^  ""  ^^°^^»  ^'^^'^  «^^^them  to  keepTem  warm. 
The  floss  being  removed  by  hand,  they  are  then  thrown  into  a  basin  of  hot  water  to  b^ 
unwound ;  which  is  done  in  a  veiy  rude  and  wasteful  way. 

^w  ^»P^^r"^*H'"''  ^""l  ^^^  ""^^f^  silkworm  in  Lower  Assam*  amount  to  5000  acres,  besides 
what  the  forests  contain;  and  yield  1500  maunds  of  84  lbs.  each  per  annum.  UppS 
Assam  IS  more  productive.  ^  v^pcr 

The  cocoon  of  the  Koutkun  mooga  is  of  the  size  of  a  fowl's  egg.  It  is  a  wild  SDecies. 
and  affords  filaments  much  valued  for  fishing-lines.     See  Silkworm  Gut  ^ 

8.  The  ^rnndy  or  Eria  worm,  and  moth,  is  reared  over  a  greit  part  of  Hin- 
dostan  but  entirely  withm  doors.  It  is  fed  principally  on  the  /fera,  or  Palma 
chrish  leaves,  and  gives  sometimes  12  broods  of  spun  silk  in  the  course  of  a  yefr.  It 
affords  a  fibre  which  looks  rough  at  first;  but  when  woven,  becomes  soft  and  silky, 
after  repeated  washings.  The  poorest  people  are  clothed  with  stuff  made  of  it,  which  is 
ZiZ  Vt  ^^^^^"^from  mother  to  daughter.  The  cocoons  are  put  in  a  closed 
^  f  1  ♦k"""  "P  '?,  ^^^h°»s«'  «"t  «f  '•each  of  rats  and  insects.  When  the  moths 
come  forth  they  are  allowed  to  move  about  in  the  basket  for  twenty-four  hours;  after 
which  the  females  are  lied  to  long  reeds  or  canes,  twenty  or  Iwenty-five  to  each,  and 

?'^'L*';%^"^,"P  '"  ^^?  *'*'"'^-  '^^^  ^^^^  ^^^t  are  laid  the  first  three  days,  amouitine 
to  about  200,  alone  are  kept ;  they  are  tied  up  in  a  cloth,  and  suspended  to  The  ro^f 
till  a  few  begin  to  hatch  These  eggs  are  white,  and  of  th^  size  of  furnip-seed  Wh^n 
a  few  of  the  worms  are  hatched,  the  cloths  are  put  on  small  bamboo  platters  hung  up  in 
the  house,  m  which  they  are  fed  with  tender  leaves.  After  the  second  moultfng" 
they  are  removed  to  bunches  of  leaves  suspended  above  the  ground,  beneath  which  a 

Zt  ll^^'^'fT'f  ^^'"^^  ''^'"  '^''  ^^"-  ^*^^"  '^'y  <=^^^^  to  feed,  they  are  thrown 
into  baskets  full  of  dry  leaves,  among  which  they  form  their  cocoons,  Iwo  or  three 

animad'l^rL  ^  *°^^^^'''      ^^""^  ^^''  injudicious  practice  I  have  already 

9.  The  Satumia  tn/enestrafa  has  a  yellow  cocoon  of  a  remarkably  silky  lustre.    It  live* 
on  the  soom-tree  in  Assam,  but  seems  not  to  be  much  used 

fJvJ^iJiT^^I'io.f  ^^^u-"*^  filature,  as  lately  improved  in  France,  is  very  ingenioas. 
^fgs.  1241  and  1212  exhibit  it  in  plan  and  longitudinal  view,  a  is  an  oblong  copper 
basin  containing  water  heated  by  a  stove  or  by  steam.  It  is  usually  divided  by  :-4nsveVse 
partitions  into  several  compartments,  containing  20  cocoons,  of  which  there  ar>  5  in 

fhro.fT  wVM  .r"«!"  ^^^  ^^"'^-  ^'  ^'  ^'^  ""''^^  ^^th  hooks  or  eyelets  at  their  ends, 
Ih^r^^h.fiV^  ?  filaments  run  apart,  and  are  kept  from  ravelling,  c,  c,  the  point! 
where   he  filaments  cross  and  rub  each  other,  on  purpose  to  clean  their  surfaces,    rf,  is 

LTTiMTV^K*!!  T"  5  P'"  P°^"^'  ^"^  ^^^^  the  traverse  molion  alternately  lo 
right  and  left,  whereby  the  thread  is  spread  evenly  over  the  surface  of  the  reel  e.  /,/,  are 
the  pulleys,  which  by  means  of  cords  transmit  the  rotatory  movement  of  the  cylinder  rf. 
to  the  reel  e.    g,  is  a  friction  lever  or  tumbler,  for  lightening  or  slackening  the  endlesi 


SILK  MANUFACTURE. 


603 


cord,  in  the  act  of  starting  or  stopping  the  winding  operation.  Every  apartment  of  a 
large  filature  contains  usually  a  series  of  such  reels  as  the  above,  all  driven  by  one  prime 
mover ;    each  of  which,  however,  may  by  means  of  the  tumbling  lever  be  stopped  at 

1241 


pleasure.     The  reeler  is  careful  lo  remove  any  slight  adhesions,  by  the  application  of  a 
brush  in  the  progress  of  her  work. 

The  expense  of  reeling  the  excellent  Cevennes  silk  is  only  3  francs  and  50  centimes 
per  Alais  pound ;  from  4  to  5  cocoons  going  lo  one  thread.  That  pound  is  92  hun- 
dredths of  our  avoirdupois  pound.  In  Italy,  the  cost  of  reeling  silk  is  much  higher, 
being  7  Italian  livres  per  pound,  when  3  to  4  cocoons  go  to  the  formation  of  one 
thread  ;  and  6  livres  when  there  are  from  4  to  5  cocoons.  The  first  of  these  raw  silk& 
will  have  a  tiire  of  20  lo  24  deniers ;  the  last,  of  24  lo  28.  If  5  lo  6  cocoons  go  to 
one  thread,  the  litre  will  be  from  26  to  32  deniers,  according  to  the  quality  of  the  co- 
coons. The  Italian  livre  is  worth  7|(i.  English.  The  woman  employed  at  the  kettle 
receives  one  livre  and  five  sous  per  day ;  and  the  girl  who  turns  the  reel,  gets  thirteen 
sous  a  day  ;  both  receiving  board  and  lodging  in  addition.  In  June,  July,  and  August, 
they  work  16  hours  a  day,  and  then  they  wind  a  rubo  or  ten  pounds  weight  of  cocoons, 
which  yield  from  l-5th  to  l-6th  of  silk,  when  the  quality  is  good.  The  whole  expenses 
amount  to  from  6  lo  7  livres  upon  every  ten  pounds  of  cocoons :  which  is  about  2*.  8d 
per  English  pound  of  raw  silk. 

The  raw  silk,  as  imported  into  this  country  in  hanks  from  the  filatures,  requires  lo  be 
regularly  wound  upon  bobbins,  doubled,  twisted,  and  reeled  in  our  silk-mills.  These  pro- 
cesses are  called  throwing  silk,  and  their  proprietors  are  called  silk  ^Arotf^/ers ;  terms  pro- 
bably derived  from  the  appearance  of  swinging  or  tossing  which  the  silk  threads  exhibit 
during  their  rapid  movements  among  the  machinery  of  the  mills. 

A  representation  of  a  French  mill  for  throwing  silk,  is  given  in  the  Dictionnairt 
Technologique,  under  the  article  Moulinage  de  Soie.  But  it  is  a  most  awkward,  operose, 
and  defective  piece  of  machinery,  quite  unworthy  of  being  presented  to  my  readers. 
It  was  in  Manchester  that  throwing-mills  received  the  grand  improvement  upon  the 
ancient  Italian  plan,  which  had  been  originally  introduced  into  this  country  by  Sir  Thomas 
Lombe,  and  erected  at  Derby.  That  improvement  is  chiefly  due  lo  the  eminent  factory 
engineers,  Messrs.  Fairbairn  and  Lillie,  who  transferred  to  silk  the  elegant  mechanism  of 
the  throstle,  so  well  known  in  the  cotton  trade.  Still,  throughout  the  silk  districts  of 
France,  the  throwing  mills  are  generally  small,  not  many  of  them  turning  off  more  than 
1000  pounds  of  organzine  per  annum,  and  not  involving  5000/.  of  capital.  The  average 
price  of  throwing  organzine  in  that  country,  where  the  throwster  is  not  answerable  for 
lass,  is  7  francs  ;  of  throwing  trame,  from  4  fr.  lo  5  fr.  (per  kilogramme  7)  Where  the 
throwsfer  is  accountable  for  loss,  the  price  is  from  10  fr.  to  11  fr.  for  organzine,  and  from 
6  to  7  for  trame.  In  Italy,  throwing  adds  3«.  9d.  to  the  price  of  raw  silk,  upon  an  average. 
I  should  imagine,  from  the  perfection  and  speed  of  the  silk-throwing  machinery  in  this 
eountry,  as  about  to  be  described,  that  the  cost  of  converting  a  pound  of  raw  silk  either  into 
organzine  or  trame  must  be  considerably  under  any  of  the  above  sums. 

SILK-THROWING  MILL. 

The  first  process  to  which  the  silk  is  subjected,  is  winding  the  skeins,  as  imported,  off 
npon  bobbins.  The  mechanism  which  effects  this  winding  off  and  on,  is  technicallf 
called  the  engine,  or  swift.    The  bobbins  to  which  the  silk  is  transferred^  are  woodei 


%M 


604 


SILK  MANUFACTURE. 


!i    « 


cylinders,  of  such  thickness  as  may  not  injure  the  silk  by  sudden  flexure,  and  which 
may  also  receive  a  great  length  of  thread   without   having  their  diameter  materiallv 
increased,  or  their  surface  velocity  changed.      Fig.  1243, is  an  end  view  of  the  silk 
throwing  machine,  or  engine,  m  which  the  two  large  hexagonal  reels,  called  swifts,  are 

1243 


Si"nfra?raulctd''   T^^  them,  to  which  the  bobbins  and  impelling 

«e  frequently  changed.    The  motion  is  communicated  ,„  th^.'end  onhrengTne  sWn  Si.' 

..„^''*  ^^"  '''■'''  '*'  '^'X'™  •>«■•«  '"  "OSS  section,  is  sometime^  of  ereat  Ien».),  .^ 
tending  20  feet  or  more,  according  to  the  size  of  the  apartment      Uwn  This  ih."  i'.?^; 

etym«,c^c''a',Ta'su\Y;Ts''j;ra  JJirj^.'^  7.%'  trf^irreSnY.''!  "■"' 
gular  sowness,  yet  they  do  their  work  mnk  quicker  han  ,„y  of 'he "m  anoa^J^t 
and  ,n  th,s  respect  may  deserve  their  name.  At  every  ei.hth  or  Li.h  w?f.^.  •  '^ 
projecting  horizontal  piece  l,,  which  carries  at  its  end  Sl,er"horizo„ tal  bar?  tiZ'kt 

iS«s™f''th:  t'::^  "  ""  ""•""■    ™^  -""''='■'  "■'  sIender'ree;s°'or rwU^^ti^^  Z 

1244  thestrucfireof  the  swifts  will  be  fully  understood.     From  the  wo«itn  shaft  6 
^j:^rt  a  ^l/f ^aJ'  L«  :'^:-:t^  Ira^e^i^ 


SILK  MANUFACTURE. 


605 


■re  set  between  each  pair  of  spokes,  to  stay  them,  and  to  keep  the  cord  tight,    e  is  one 
of  the  two  horizonul  shafts,  placed  upon  each  side  of  the  engine,  to  which  are  afiixed 


a  number  of  light  iron  pulleys  g,  g  (shown  on  a  double  scale  in^ig.  1245.  (These  serve, 
by  friction,  to  drive  the  bobbins  which  rest  upon  their  peripheries. 

To  the  Uble  A,^g.l24.S,are  screwed  the  light  cast-iron  slot-bearings  i,  i,  wherein 
the  horizontal  spindles  or  skewers  rest,  upon  which  the  bobbins  revolve.  The  spindles 
(sec  Fj^g.  1249.)  carry  upon  one  end  a  little  wooden  pulley  A,  whereby  they  press  and 
revolve  upon  the  larger  driving  pulleys  g,  of  the  shaft  e.  These  pulleys  are  called 
$tars  by  our  workmen.  The  other  ends  of  the  spindles,  or  skewers,  are  cut  into  screws, 
for  attaching  the  swivel  nuts  i  (Jig,  1249.)  by  which  the  bobbins  k,  k,  are  made  fast  to 

their    respective    spindles. 
. f..^  f.j^-^         I  G  *      Besides  the  slots,  above  de- 

^  //>.-^         H  ™.,^r>      scribed,  in  which  the  spin- 

dles rest  when  their  friction 
pulleys   A,    are    in   contact 


with  the  moving  stars  g, 
there  is  another  set  of  slots 
in  the  bearings,  into  which 
the  ends  of  the  spindles  may 
be  occasionally  laid,  so  as 
to  be  above  the  line  of  coll- 
ect of  the  rubbing  periphery  of  the  star  g,  in  case  the  thread  of  any  bobbin  breaks.  When- 
ever the  girl  has  mended  the  thread,  she  replaces  the  bobbin-spindle  in  its  deeper  slot-bear- 
ings, thereby  bringing 


1249 


1246 


its  pulley  once  more  into 
contact  with  the  star, 
and  causing  it  to  revolre. 
6  is  a  long  ruler  or 
bar  of  wood,  which  is 
supported  upon  every 
eighth  or  twelfth  leg  b, 
B.  (The  figure  being,  for 
convenience  of  the  page, 
contracted  in  length, 
shows  it  at  every  sixth 
leg.)  To  the  edge 
of  that  bar  the  smooth 
l^ass    rods    Jt,   are    made  fast,   over    which    the    threads   glide  from  the  swifts,  in 


M. 


I 


W  ■  ii 


a 


i 


r  ■  i  1  !ii  ; 


«06 


SILK  MANUFACTURE, 


1247 


their  way  to  the  bobbins,  h  is  the  guide  bar,  which  has  a  slow  traverse  or  seesaw  rot 
tion,  sliding  m  slots  at  the  top  of  the  legs  b,  where  they  support  the  bars  g.  Upon  th« 
guide  bar  h,  the  guide  pieces  /,  I,  are  made  fast.  These  consist  of  two  narrow,  thin,  up. 
right  plates  of  iron,  placed  endwise  together,  their  contiguous  edges  being  smooth,  piral- 
leJ,  and  capable  of  approximation  to  any  degree  by  a  screw,  so  as  to  increase  or  diminish 
at  pleasure  the  ordinary  width  of  the  vertical  slit  that  separates  them.  Through  this  slii 
the  silk  thread  must  pass,  and,  if  rough  or  knotty,  will  be  either  cleaned  or  broken ;  in 
tne  latter  case,  it  is  neatly  mended  by  the  attendant  girl. 

The  niotions  of  the  various  parts  of  the  engine  are  given  as  follows.  Upon  the  end  of 
the  machme,  represented  in  fig.  1243  there  are  attached  to  the  shafts  e  (fig  1244)  the 
bevel  wheels  1  and  2,  which  are  set  in  motion  by  the  bevel  wheels  3  and  4,  rJsnectivelv 
These  latter  wheels  are  fixed  upon  the  shaft  m,fig.  1243.  m  is  moved  by  the  main  steam 
shaft  which  runs  parallel  to  it,  and  at  the  same  height,  through  the  length  of  the  enein* 
apartment,  so  as  to  drive  the  whole  ran^e  of  the  machines.  5  is  a  loose  wheel  or  pulley 
upon  the  shaft  rn,  working  in  gear  with  a  wheel  upon  the  steam  shaft,  and  which  mav 
^L?^""u  .^^^^^*^^''^''^'*'^^"'°""^  ^^^  ^^"'^  lever  or  gearing  rod  o  (/ig«.  1 243  and 
u-  u  u  "  ^^  ^""^"^  *^  ^**  ^^  ^^^  **  ^^°''^-  ^  »s  *  SP">^  w^eel  upon  the  shaft  n>,  by 
Which  the  stud  wheel  7  is  driven,  in  order  to  give  the  traverse  motion  to  the  guide  bar 
?<;.o  -l^^^^  *^  represented,  with  its  appendages,  in  double  size, ^g*.  1247  and 
1J48  with  Its  boss  upon  a  stud  p,  secured  to  the   bracket  q.     In  an  eccentric  hole 

1248    t  ^    .n       -J        ^oA^^     of  the  same  boss,  another  stud  r,  revolvcs.  Upon 

which  the  little  wheeU,  is  fixed.  This  wheel  *, 
is  in  gear  with  a  pinion  cut  upon  the  end  of 
the  fixed  stud  p ;  and  upon  it  is  screwed  the 
little  crank  t,  whose  collar  is  connected  by  two 
rods  u  (figs.  1243  and  1244),  to  a  cross-piece  v 
v/hich  unites  the  two  arms  w,  that  are  fixed  upon 
the  guide  bar  h,  on  both  sides  of  the  machine. 
By  the  revolution  of  wheel  7,  the  wheel  s  will 
cause  the  pinion  of  the  fixed  stud  p  to  turn 

-  ^       ,     ,        ,        round.    If  that  wheel  bear  to  the  pinion  the 

proportion  of  4  to  1,  then  the  wheel  s  will  make,  at  each  revolution  of  the  wheel  7  one 
fourth  of  a  revolution  ;  whereby  the  crank  t  will  also  rotate  through  one  fourth  of  a  turn 
so  as  to  be  brought  nearer  to  the  centre  of  the  stud,  and  to  draw  the  guide  bar  so  much 
Jess  to  one  side  of  its  mean  position.     At  the  next  revolution  of  wheel  7,  the  crank  /  will 
move  through  another  quadrant,  and  come  still  nearer  to  the  central  position,  drawing 
the  guide  bars  still  less  aside,  and  therefore  causing  the  bobbins  to  wind  on  more  thread 
in  their  middle  than  towards  their  ends.    The  contrary  eifect  would  ensue  were  the 
guide  bars  moved  by  a  single  or  simple  crank.    After  four  revolutions  of  the  wheel  7 
the  crank  t  will  stand  once  more  as  shown  in^g.  1248  having  moved  the  bar  h  through 
the  whole  extent  of  its  traverse.     The  bobbins,  when  filled,  have  the  appearance  renre 
sented  in^g.  1250 ;  the  thread  having  been  laid  on  them  all  the  time  in  diagonal  lines  so 
as  never  to  coincide  with  each  other.  "  ' 

Doubling  is  the  next  operation  of  the  silk  throwster.  In  this  process,  the  threads  ol 
two  or  three  of  the  bobbins,  filled  as  above,  are  wound  together  in  contact  upon  a  single 
bobbin  An  ingenious  device  is  here  employed  to  stop  the  winding-on  the  moment  that 
one  of  these  parallel  threads  happens  to  break.  Instead  of  the  swifts  or  reels,  a  creel  is 
here  mounted  for  receiving  the  bobbins  from  the  former  machine,  two  or  three  beinff 
placed  in  one  line  over  each  other,  according  as  the  threads  are  to  be  doubled  or  trebled 
iv.u  lu^J?"?^^"'^  *^  '"  ""*"y  respects  like  the  engim,  it  has  some  additional  parts! 
whereby  the  bobbins  are  set  at  rest,  as  above  mentioned,  when  one  of  the  doubling  threadt 
gels  broken.  =•  "'tcauB 

-Ftg.l251is  an  end  View  from  which  it  will  be  perceived  that  the  machine  is,  like  the 
preceding,  a  double  one,  with  two  working  sides.  ' 

^ig.l252is  a  front  view  of  a  considerable  portion  of  the  machine, 
i'ngff  bobbin^°^^  part  of  a  cross  section,  to  explain  minutely  the  m^e  of  winding  upon  • 

Fig.  1254is  the  plan  of  the  parts  shown  in^g.  1253  ;  these  two  figures  being  drawn  to 
double  the  scale  ofylg*.  125 land  1252.  ««"  w 

A,  A,  figs.  1251  ^1262,  are  the  end  frames,  connected  at  their  tops  by  a  wooden  stretcher 
or  bar^eam,  «,  which  extends  through  the  whole  length  of  the  machine ;  this  bar  is  shown 
also  in/g«.  1253  and  12o4. 

B  B,  are  the  creels  upon  each  side  of  the  machine,  or  bobbin  bearers,  resting  upon 
wooden  beams  or  boards,  made  fast  to  the  arms  or  brackets  c,  about  the  middle  of  th« 
frames  a. 

D,  D,  are  two  horizontal  iron  shafts,  which  pervade  the  whole  machine,  and  carry  a 
•enes  of  light  moveable  pulleys,  called  stars,  c,  c,  (figs  1 253,1 254.)which  serve  to  drive  tht 


t>n.K  MANUFACTUllE. 


607 


bobbins  e,  e,  whose  fixed  pulleys  rest  upon  their  peripheries,  and  are  therefore  tomed 
wnply  by  friction.    These  bobbins  are  screwed  by  swivel  nuts  «,  c,  upon  spindles,  as  m 

the  silk  engine.  Be. 
sides  the  small  friction 
pulley  or  boss,  d,  seen 
best  in  fig.  1254,  by 
which  they  rest  upon 
the  star  pulleys  c,  c,  a 
little  ratchet  wheel  /, 
is  attached  to  the  other 
end  of  each  bobbin. 
This  is  also  shown  by 
itself  at/,  in  ^g.  1255. 
The  spindles  with 
their  bobbins  revolve 
in  two  slot-bearings 
F,  F,  fig.  1254,  screwed 
to  the  bar-beam  a, 
which  is  supported  by 
two  or  three  interme- 
diate upright  frames, 
such  as  a'.  The  slot 
bearings  f,  have  also 
a  second  slot,  in  which 

the  spindle    with   the 

bobbin  is  laid  at  rest,  out  of  contact  of  the  star  wheel,  while  its  broken  thread  is  being 
mended,  g  is  the  g-uide  bar  (to  which  the  cleaner  slit  pieces  g,  g,  are  attached),  for 
H  1252 


i 


^=q^^^^jg^ 


frT~r^^p=!^ 


*^m 


'^1 


n 


II 


II 


II 


i( 


II 


II 


N 


^™™ 


^^^*^^^ 


making  the  thread  trayerse  to  the  right  and  the  left,  for  its  proper  distribution  over 
the  surface  of  the  bobbin.  The  guide  bar  of  the  doubling  machine  is  moved  with  a 
slower  traverse  than  m  the  engine ;  otherwise,  in  consequence  of  the  difl^erent  obliquities 
of  the  paths,  the  single  threads  would  be  readily  broken,  h,  h,  is  a  pair  of  smooth  rods  of 
iron  or  brass,  placed  parallel  to  each  of  the  two  sides  of  the  machine,  and  made  fast  to  the 
standards  H,  h,  which  are  screwed  to  brackets  projecting  from  the  frames  a,  a'.  Over  these 
rods  the  silk  threads  glide,  in  their  passage  to  the  guide  wires  g,  g,  and  the  bobbins  e,  e. 
I,  I,  is  the  lever  board  upon  each  side  of  the  machine,  upon  which  the  slight  brass 
beanngs  or  fulcrums  t,  t,  one  for  each  bobbin  in  the  creel,  are  made  fast.  This  board 
bears  the  balance-lever  k  I,  with  the  falters  n,  n,  n,  which  act  as  dexterous  fingers,  and 
Btop  the  bobbin  from  wmdmg-on  the  instant  a  thread  may  chance  to  break.  The  levers 
ft,  /,  swing  upon  a  fine  wire  axis,  which  passes  through  their  props  t,  t,  their  arms  being 
shaped  rectangularly,  as  shown  at  fc,  fc',yig.  1254.  The  arm  /,  being  heavier  than  the  arm  fc, 
naturally  rests  upon  the  ridge  bar  w?,  of  the  lever  board  r.  «, «, «,  are  three  wii  es,  resting 
at  one  of  their  ends  upon  the  axis  of  the  fulcrum  t,  i,  and  having  each  of  their  other  hooked 
ends  suspended  by  one  of  the  silk  threads,  as  it  passes  over  the  front  steel  rod  h.  and  undei 


III!  \ 


S 


608 


SILK  MANUFACTURE. 


iriti.^     ^  ^^'^K'^''*^,'*^''**^^**"^^'!'*r«  ^""'^^  truly  in  their  up-and-down  motioni 

with  the  thread,  by  a  cleaner-plate  o,  having  a  vertical  slit  in  its  middle.     Hence,  when- 

ever  any  thread  happens  to  break,  in  its  way  to  a  winding-on  bobbin  k  the  wfre  n^ 

1258         ^  I  which  hung  by  its  eyelet  end 

to  that  thread,  as  it  passed 
through  between  the  steel  rods 
in  the  line  of  A,  A',  falls  upon 
the  lighter  arm  of  the  balance 
lever  fc,  /,  weighs  down  that 
arm  fc,  consequently  jerks  up 
the  arm  /,  which  pitches  its  tip 
or  end  into  one  of  the  three 
notches  of  the  ratchet  or  catch 
wheel  /  (Jigs.  1254  &  1255), 
fixed  to  the  end  of  the  bobbin. 
Thus  its  motion  is  instantane- 
ously arrested,  till  the  girl  has 
had  leisure  to  mend  the  thread, 
when  she  again  hangs  up  the 
faller  wire  n,  and  restores  the 

tJnn      TP  ^o««^k-i      I.     .    1  .  leverfe,/,  to  its  horizontal  posi- 

t  on.  If;  meanwhile,  she  took  occasion  to  remove  the  winding  bobbin  out  of  the  sunk 
slot-bearing,  where  pulley  d  touches  the  star  wheel  .,  into  the  right-hand  upper  slot  of 
repose,  she  must  now  shift  it  into  its  slot  of  rotation.  ^^ 

The  motions  are  given  to  the  doubling 
machine  in  a  very  simple  way.  Upon  the 
end  of  the  framing,  represented  in^g  1251, 
the  shafts  d,  d,  bear  two  spur  wheels  1  and 
2,  which  work  into  each  other.  To  the 
wheel  1,  is  attached  the  bevel  wheel  3, 
driven  by  another  bevel  wheel  4  (Jig. 
1252),  fixed  to  a  shaft  that  extends  the 
whole  length  of  the  apartment,  and  serves, 
therefore,  to  drive  a  whole  range  of  ma- 
chines. The  wheel  4  may  be  put  in  gear 
with  the  shaft,  by  a  clutch  and  g'ear- 
handle,  as  in  the  silk  engine,  and  thereby  it 
drives  two  shafts,  by  the  one  transmitting 
Its  movement  to  the  other. 

js  effected  as  follows  =  -iT^n  one  of  ,he  shafts  .^'.L'r^l^TbTrwhed  5  'dtl„1",h°^ 
S^-Jlr      >.    '  "IT  ""f-  '"?  °^  'he  upright  shaft  p  (fig.  1252,  to  the  ri-hrof  the 

.Jailer  which  is  fixed  to  the  e'„d  of ':h:^fve'^';';Ue\  Ki^  f  t^TT^r'^Ihe' 

rrb^^s^e^-^rehioirtre^.V/zr 

t7^f:ttr"^ji  whTi?tCrsr;rt  tJ:^!^^  i^ 
^rhKnt";  .^e^:fdi^:/thfp^«^sP^^ 

The  motion  is  given  to  this  shaft  in  the  following  w«v  TTr,««  ♦!,«  u  •  .  • 
AaO  J,  there  is  a  bevel  wheel  g  (fig,.  1252  and  125^  "v\ie?'dVi,eYKe  ^LlToT^l 
the  shaft  a:;   on  whose  upper  end,  the  worm  v  work-in  ih»  «ill  i  11     ^    r  ^/."P?" 

JJi:  r=eS'tt'-irclli:dTe'''^pi„t'f ^r^  i^X"-"''  '^r  -  '5'" 

twisted  in  one  direction,  next  doubled  and  tl^ln%w!*P^  t  »^^^  -^  u^"^  singles  are  first 
an  exceedingly  wiry,  compact  thread, Co^^^^^^^^  theopposite  direction, 

either  the  singles  or  the  doubled  silk  whilTbei?^  unwoS  ?ror*nnJ  .  VC!l'"""''"i 
wound  upon  another  set,  is  subjected  to  a  reef,  W  ^LI^"  '^^°™  °"^  ^^f  °^  bobbms,  and 
the  thread  is  conducted  ^s  usuathrouSi  -aides ^^^^^  S?**"*''"n  '  *"  "^^['^  ^^'^^^^^ 

by  a  proper  mechanism.  ^   "    ^'''  *"^  "''^^^  diagonally  upon  the  bobbins 

J't^.  1256  exhibits  an  end  view  of  the  soinninw  t«:n .   :«  ^u-^x,  r  i  •      ». 

.re  shown ;  two  tiers  upon  each  side,  one  Xv^e  Vler*"^  w\JZin7  mlSf  Lav" 


SILK  MANUFAGTC/RE. 


609 


1266 


Ihicc  working  tiers  upon  each  side;  but  as  the  highest  tier  must  be  reached  by  a  laddex 
or  platform,  this  construction  is  considered  by  many  to  be  injudicious. 

J^iff.  1267,  ia  a  front  view,  where,  as 
in  the  former  figure,  the  two  working 
lines  are  shown. 

Ficf.  1258,  is  a  cross  section  of  a  part 
of  the  machine,  to  illustrate  the  cod- 
struction  and  play  of  the  working  parts ; 
^gs.  1264,  1265,  are  other  views  of  J^. 
1258. 

Fir/.  1259,  shows  a  single  part  of  the 
machine,  by  which  the  bobbins  are  made 
to  revolve. 

Figs.  1260,  and  1261,  sliow  a  dif- 
ferent mode  of  giving  the  traverse  to 
the  guide  bars,  than  that  represented  in 
Jig.  1268. 

Figs,  1262,  and  1263,  show  the  shape 
of  the  full  bobbins,  produce!  by  the 
action  of  these  two  different  traverse 
motions. 

The  upper  part  of  the  machine 
oeing  exactly  the  same  as  the  under 
part,  it  will  be  sufficient  to  explain  the 
construction  anii  operation  of  one  of 
them. 

A,  A,  are  the  end  upright  frames  or 
standards,  between  which  are  two  or 
three  intermediate  standards,  accord- 
ing to  the  length  of  the  machine. 
They  are  all  connected  at  their  sides 
by  beams  b  and  c,  which  extend  the 
whole  length  of  the  machines,  d.  d, 
made  fast  to  the  beams  b,  and  their 
These  two  bars  together  are 


«re  the  spindles,  whose  top  bearings  o,  a,  are 
bottoms  turn  in  hard  brass  steps,  fixed  to  the  bar  c. 

^  1257 


Wi 


610 


SILK  MANUFACTURE. 


4. 


called,  by  the  workmen,  the  spindle  box.    The  standards  A,  a,  are  bound  with  cwbb  Wun 

Mm.       Urn 


SILK  MANUFACIURE. 


611 


Vj  N. 


the'  Unll'of^E  r Y/?256  1 W  ^f J  'Z'^  ^V  r'"^  x^^^'"  '^'  ^«"^«»t*l  ^in  cylinder  in 
the  J  nes  ol  e,  e,  Jig.  1256  lying  m  the  middle  line  between  the  two  oarallel  rows  of 

spindles  D,  D  F,  F,  are  the  bobbins  containing  the  untwisted  doXd  sS  wh'ch  a^ 
simply  pressed  down  upon  the  taper  end  of  the  spindles,  d,  d,  are  Uuie  fl^ers,^ 
forked  wings  of  wire,  attached  to  washers  of  wood,  which  revolve  W  upon  the^ops 
of  the  said  bobbins  f,  and  round  the  spindles.  One  of  the  wings  is  somethn^  S 
upwards  to  serve  as  a  guide  to  the  silk,  as  shown  by  dotted  lines  in  fig.  U 58  TiZTe 
pieces  of  wood  pressed  upon  the  tops  of  the  spindles,  to  prevent  the  flfers  froin  ttartLg 
off  by  the  centrifugal  force,  g,  are  horizontal  shafts  bearing  a  number  of  Tittle  sou? 
?^ff I'  ¥'  !!'  ""'1  slot-bearings,  similar  to  those  of  the  doubling-mSne  wh  ch  S^e 
fixed  to  the  end  and  middle  frames.  In  these  slots,  the  li^ht  square  casi-iron  shafts  ^J 
spindles  g,/.g.  1257  are  laid,  on  whose  end  the  spur  wheel  h  is  Sst ;  and  when  the  shaft  ^ 
lies  in  he  front  slot  of  its  bearing,  it  is  in  gear  with  the  wheel  /,  upon  the  snaft  g  bu^ 
when  It  IS  laid  m  he  back  slot,  it  is  out  of  ^ear.  and  at  rest.  See  f,  f,  fiTlo^l  ' 
Upon  these  Jittle  cast-iron  shafts  or  spindles  g.fig.  1259.  the  bobbins  or  blocks  i,  are 

thrust,  for  receiving,  by  winding-on,  the  twisted 
or  spun  silk.  These  blocks  are  made  of  a  large 
diameter,  in  order  that  the  silk  fibres  may  not  be 
too  much  bent ;  and  they  are  but  slightly  fillevL 
at  each  successive  charge,  lest,  by  increasing  their 
diameter  too  much,  they  should  produce  too  rapid 
an  increase  in  the  rate  of  winding,  with  propor- 
tional diminution  in  the  twist,  and  risk  of  stxetch- 
mg  or  tearing  the  silk.  They  are  therefore  the  more 
frequently  changed,  k,  k,  are  the  guide  bars,  with 
the  guides  i,  t,  through  which  the  silk  passes,  being 
drawn  by  the  revolving  bobbins  i,  and  delivered 
or  laid  on  by  the  fliers  d,  d,  from  the  rotatory 
twisting  bobbins  f.  The  operation  of  the  ma- 
chine IS  therefore  simple,  and  the  motions  are 
given  to  the  parts  in  a  manner  equally  so. 

Upon  the  shaft  of  the  tin  cylinder  or  drum, 
exterior  to  the  frame,  the  usual  fast  and  loose 
pulleys,  or  riggers,  l,  l',  are  mounted,  for  driving 
the  whole  machine.  These  riggers  are  often  called 
steam-pulleys  by  the  workmen,  from  their  being 
connected  by  bands  w;ith  the  steam-driven  shaft 
of  the  factory.  In  order  to  allow  the  riggers  upon 
the  shafts  of  the  upper  and  the  under  drums  to 
be  driven  from  the  same  pulley  upon  the  main 
shaft,  the  axis  of  the  under  drum  is  prolonged  at 
r,  L',  and  supported  at  its  end,  directly  from  the 
floor,  by  an  upright  bearing.     Upon  the  shafts 
of  the  tin  cylinders  there  is  also  a  fly-wheel  m, 
to  equalize  ihe  motion.     Upon  the  other  ends  of 
these  shafts,  namely,  at  the  end  of  the  spinning- 
mill,  represented  in  ;?g.  1256,  the  pinions  1  are 
fixed,  which  drive  the  wheels  3,  by  means  of  the 
intermediate  or  carrier  wheel  2;  called  also  the 
p  ate  wheel,  from  its  being  hollowed  somewhat 
like  a  trencher.  1,  is  called  the  change-pinion,  be- 
cause  It  IS  changed  for  another,  of  a  different  size 
Uieveloc-tvnf  wV,«-ro     A  o  '   .   i.     *"^  ^^fferent  number  of  teeth,  when  a  change  in 

be  alSt  1   thf  th  ^"9  •  ''  ^"^  ^  r^'^''    ^"^  ""^^  *  ^'^^''  «^  ^"^^"er  pinion  to 
DC  applied  at  1,  the  wheel  2  is  mounted  upon  a  stud  fe,  which  is  moveable  in  n  «lnt  /.nrT 

t^^ZT  'l"  "^'^  ef.'he.^hed  3.    Tu!  sM  is  a  brin^hfrom  ThJ  cr^'bar  t  n'e 
smaller    he  change-pnuon  is,  the  nearer  will  the  stud  k  approach  to  the  vertical  Ine 

iZH^  T.  T'"'  "^  I^^V  ""u"  ^  \  """  '"«  "">«  slowly  will  the  pUte  wherf  2l^ 
driven.  To  the  spur  wheel  3,  a  bevel  wheel  4,  is  fixed,  with  which  the  other  also 
revolves  loose  upon  the  stud.  The  bevel  wheel  5  upon  the  shaft  ;,is  driven  by  the  wS 
whee  4;  and  .t  communicates  motion,  by  the  bevel  wheels  6  and  7,  to  each  of  the  Wi- 
.ontal  shafts  g  c  extending  alon?  the  upper  and  under  tiers  of  the  machine.  A,  .he 
o  ,tw  ,r  ^  °'^  •  "  '°?  T  l^-^^-  '-^^-'''^  '"»  ''''«'«  6  «»d  7  are  omitted,  on  purpos^ 

itrs'of%'e™b;;£:.' '"  ^""^  "•  "^  "^  "^  ^'"'-'-""'^ «"  ««^'"s  '^«  ^^•^ 


If  it  be  desired  to  communicate  twist  in  the  opposite  direction  to  that  which  would 
be  given  by  the  actual  arrangement  of  the  wheels,  it  is  necessary  merely  to  transpose 
the  carrier  wheel  2,  from  its  i)resent  position  on  the  right  hand  of  pinion  1,  to  the 
left  o'f  it,  and  to  drive  the  tin  cyliuder  by  a  crossed  or  close  strap,  instead  of  a  straight  or 
open  one. 

The  traverse  motion  of  the  guide  is  given  here  in  a  similar  way  to  that  of  the  engine, 
(fig'  1243.)  Near  one  of  the  middle  or  cross-frames  of  the  machine  (see  fig.  1258) the 
wheel  /,  in  gear  with  a  spur  wheel  /i,  upon  one  of  the  block-shafts,  drives  also  a  spur 
wheel  m,  that  revolves  upon  a  stud,  to  which  wheel  is  fixed  a  bevel  wheel  n,  in  gear 
with  the  bevel  wheel  o.  To  wheel  o,  the  same  mechanism  is  attached  as  was  described 
under/g«.  1247  and  1248,  and  which  is  here  marked  with  the  same  letters. 

To  the  crank-knob  r,j^^.  1269,a  rod  ar,  is  attached,  which  moves  or  traverses  the  guide 

bar  belonging  to  that  part  of 
the  machine ;  to  each  ma- 
chine one  such  apparatus  is 
fitted.  In  ^g«.  1260  and  1261 
another  mode  of  traversing 
the  guide  bar  is  shown,  which 
is  generally  used  for  the 
coarser  qualities  of  silk. 
Near  to  one  of  the  middle 
frames,  one  of  the  wheels  fy 
in  gear  with  the  spur  wheel 
m,  and  the  bevel  wheel  «, 
both  revolving  on  one  stud, 
gives  motion  also  to  the 
wheel  0,  fixed  upon  a  shaft 
-,  a',   at  whose  other  end  the 

elliptical  wheel  6'  is  fixed,  which  drives  a  second  elliptical  wheel  c',  in  such  a  way  that 
the  larger  diameter  of  the  one  plays  in  gear  with  the  smaller  diameter  of  the  other ;  the 
teeth  being  so  cut  as  to  take  into  each  other  in  all  positions.     The  crank-piece  d'  is  screwed 
1262  1263  upon  the  face  of  the  wheel  c',  at  such  a  distance  from  its  centre 

as  may  be  necessary  to  give  the  desired  length  of  traverse  motion 
to  the  guide  bar  for  laying  the  silk  spirallv  upon  the  blocks. 
The  purpose  of  the  elliptical  wheel  is  to  mod'ii'y  the  simple  crank 
motion,  which  would  wind  on  more  silk  at  the  ends  of  the  bob- 
bins than  in  their  middle,  and  to  effect  an  equality  of  winding- 
on  over  the  whole  surface  of  the  blocks.  In  ^g-.1261  the  elliptical  wheels  are  shown  in 
front,  to  illustrate  their  mode  of  operating  upon  each  other.    Fig.  1262  is  a  block  filled 

by  the  motion  of 
the  eccentric,  fig. 
1258;  and  fig, 
1263  is  a  block 
filled  by  the  ellip- 
tical mechanism. 
As  the  length  of 
the  motions  of  the 
bar  in  the  latter 
construction  re- 
mains the  same  during  the  whole  operation,  the  silk,  as  it  is  wound  on  the  blocks,  will 
slide  over  the  edges,  and  thereby  produce  the  flat  ends  of  the  barrel  in  fig.  1263.  The 

conical  ends  of  the  block  (fig.  1262)  are  produced  by  the  con- 
tinually shortened  motions  of  the  guide  bar,  as  the  stud  ap- 
proaches, in  its  sun-and-planet  rotation,  nearer  to  the  genera] 
centre. 

i''tg».l  264,1 265  are  two  different  views  of  the  differential  me- 
chanism described  under yig.  1258, 

The  bent  wire  x,  ^g.  1258,  is  called  the  guider  iron.     It  is 
attached  at  one  end  to  the  pivot  of  the  sun-and-planet  wheel- 

7     work  /,  4,  0,  and  tt 


1264 


K 


i 


1265 


cm 


H 


umik 


^ 


W 


'6 


the   other    to    the 

guide    bar    /,  /, 

fig.     1257,       The 

silk   threads    pass 

through  the  guides,  as  already  explained.    By  the  motion  communicated  to  the  guide  bar 

(gvtder),  the  diamond  pattern  is  produced,  as  shown  in^g.  1262. 


— ":-i" I—"  fi  ■■  TCi  "='  ■  -  -  ;-t~^"  T  "^ 


i 


I 

-A  I 


w 


mi 


612 


SILK  MANUFACTURE. 


THE   SILK   AUTOMATIC  BE£L. 


In  this  machine,  the  silk  is  unwound  from  the  blocks  of  the  throwing-mill,  and  formed 
into  hanks  for  the  market.  The  blocks  being  of  a  large  size,  would  be  productive  of 
much  friction,  if  made  to  revolve  upon  skewers  thrust  through  them,  and  would  cause 
frequent  breakage  of  the  silk.  They  are,  therefore,  set  with  their  axes  upright  upon  a 
board,  and  the  silk  is  drawn  from  their  surface,  just  as  the  weft  is  from  a  cop  in  the 
shuttle.  On  this  account  the  previous  winding-on  must  be  executed  in  n  very  regular 
manner;  and  preferably  as  represented  in  fig.  1'1&2, 

fig.l266isafront  viewof  the  reel;  little  more  than  one  half  of  it  being  shown. 
Fig.  1267  is  an  end  view.    Here  the  steam  pulleys  are  omitted,  for  fear  of  obstructing  th« 

D  1266 


view  of  the  more  essential  parts,  a,  a,  are  the  two  end  framings,  connected  by  mahogany 
stretchers,  which  form  the  table  b,  for  receiving  the  bobbins  c,  c,  which  are  sometimes 
"weighted  at  top  with  a  lump  of  lead,  to  prevent  their  tumbling,  d  is  the  reel,  consisting 
of  four  long  laths  of  wood,  which  are  fixed  upon  iron  frames,  attached  to  an  octagonal 
wooden  shaft.  The  arm  which  sustains  one  of  these  laths  is  capable  of  being  bent  in- 
wards, by  loosening  a  tightening  hook,  so  as  to  permit  the  hanks,  when  finished,  to  be 
taken  oflT,  as  in  every  common  reel. 

The  machine  consists  of  two  equal  parts,  coupled  together  at  a,  to  facilitate  the  removal 
of  the  silk  from  either  half  of  the  reel ;  the  attendant  first  lifting  the  one  part,  and  then 
the  other,  b  is  the  guide  bar,  which  by  a  traverse  motion  causes  the  silk  to  be  wound 
on  in  a  cross  direction.  6  and  c  are  the  wire  guides,  and  d  are  little  levers  lying  upon 
the  cloth  covered  guide  bar  e.  TTie  silk,  in  its  way  from  the  block  to  the  reel,  passes 
under  these  levers,  by  which  it  is  cleaned  from  loose  fibres.  ^^ 

^  On  the  other  end  of  the  shaft  of  the  reel,  the  spur  wheel  1  is  fixed,  which  derives  mo 
tion  from  wheel  2,  attached  to  the  shaft  of  the  steam-pulley  f.  Upon  the  same  shaft 
there  is  a  bevel  wheel  3,  which  impels  the  wheel  4  upon  the  shaft  «;  to  whose  end  a 
plate  18  attached,  to  which  the  crank  /is  screwed,  in  such  a  way  as  to  give  the  proper 
length  of  traverse  motion  to  the  guide  bar  e,  connected  to  that  crank  or  eccentric  stud  by 
the  jomted  rod  g.    Upon  the^shaft  of  the  steam-pulleys  f,  there  is  a  worm  or  endless 

I^a"^'  IV  %^..?^-C'H'^^^l''^^'^^  ^°'^^  ^"  »  ^^*^el  5>  attached  to  the  short  upright 
shaft  /t  (fig.  1266).  At  the  end  of  A,  there  is  another  worm,  which  works  in  a  wheel  6  • 
at  whose  circumterence  there  is  a  stud  i,  which  strikes  once  at  every  revolution  a^'ainst 
an  arm  attached  to  a  bell,  seen  to  the  left  of  g  ;  thus  announcing  to  the  reel  tente'r  that 
a  measured  length  of  silk  has  been  wound  upon  her  reel,  e  is  a  rod  or  handle,  by  which 
the  fork  /,  with  the  strap,  may  be  moved  upon  the  fast  or  loose  pulley,  so  as  to  set  on  or 
arrest  the  motion  at  pleasure. 
Throwsters  submit  their  silk  to  scouring  and  steaming  processes.     They  soak  the 


SILK. 


613 


hankS;  as  imported,  in  lukewarm  soap-water  in  a  tub ;  but  the  bobbins  of  the  twisted 
single  silk  from  the  spinning  mill  are  enclosed  within  a  w^ooden  chest,  and  exposed  to 

the  opening  action  of  steam  for  about  ten  minutes. 
They  are  then  immersed  in  a  cistern  of  warm  water, 
from  which  they  are  transferred  to  the  doubling  frame. 
The  wages  of  the  workpeople  in  the  silk-throw- 
ing mills  of  Italy  are  about  one  half  of  their  wages 
in  Manchester;  but  this  difference  is  much  more 
than  counterbalanced  by  the  protecting  duty  of  2s, 
lOd.  a  pound  upon  thrown  silk,  and  the  superior 
machinery  of  our  mills.  In  1832,  there  was  a 
power  equal  to  342  horses  engaged  in  the  silk-* 
throwing  mills  of  Manchester,  and  of  about  100  ia 
the  mills  of  Derby.  The  power  employed  in  the 
other  silk  mills  of  England  and  Scotland  has  not 
been  recorded.  r   ^ ;  •  i  :  , 

There  is  a  peculiar  kind  of  silk  called  marabouty 
containing  generally  three  threads,  made  from  the 
white  Novi  raw  silk.  From  its  whiteness,  it  takes 
the  most  lively  and  delicate  colors  without  thc' 
discharge  of  its  gum.  After  being  made  into  tram 
by  the  single  twist  upon  the  spinning  mill,  it  is 
reeled  into  hanks,  and  sent  to  the  dyer  without  fur- 
ther preparation.  After  being  dyed,  the  throwster 
re- winds  and  re-twists  it  ui>on  the  spinning  mill,  in 
order  to  give  it  the  whipcord  hardness  which  consti- 
tutes the  peculiar  feature  of  marabout.  The  cost 
of  the  raw  Novi  silk  is  I9s.  6d.  a  pound;  of  throw- 

,  „     _.>^.\     ^'^o  ^^  ^^^^  tram,  2s.  6d. ;  of  dyeing,  2*.  •,  jf  re-wind- 

■Hii'  '^  m    m     ing  and  re-twisting,  after  it  has  been  dyed,  about 

5«.;  of  waste,  2a.,  or  10  per  cent. :  the  total  of  which  sum  is  31  a. ;  being  the  price  of 
one  pound  of  marabout  in  1832. 

SILK.     Several  pieces  of  silk  were  put  into  my  hands,  for  analysis,  on  the  I8th  of 
February,  after  I  had,  on  tht  preceding  12th  of  the  month,  visited  the  St.  Katharine's 
Dock  warehouses,  in  New  street,  Bishopsgate  street,  for  the  purpose  of  inspecting  a ' 
large  package  of  the  Corahs,  per  Colonist.     I  was  convinced,  by  this  inspection,  that,' 
notwithstanding  the  apparent  pains  bestowed  upon  the  tin  plate  and  teakwood  packing- 
cases,  certain  fissures  existed  in  them,  through  which  the  atmospheric  air  had  found 
access,  and  had  caused  iron-mould  spots  upon  the  gunny  wrapper,  from  the  rusting  or ' 
oxidizement  of  the  tinned  iron. 

I  commenced  my  course  of  analysis  upon  some  of  the  pieces  which  were  most 
damaged,  as  I  thought  they  were  most  likely  to  lead  me  to  an  exact  appreciation  of 
the  cause  of  the  mischief;  and  I  pursued  the  following  general  train  of  research  : — 

1.  The  piece  of  silk,  measuring  from  6  to  7  yards,  was  freely  exposed  to  the  air,  then 
weighed,  afterward  dried  near  a  fire,  and  weighed  again,  in  order  to  determine  its 
hygrometric  property,  or  its  quality  of  becoming  damp  by  absorbing  atmospheric  vapor. 
Many  of  the  pieces  absorbed,  in  this  way,  from  one  tenth  to  one  eighth  of  their  whole 
weight;  that  is,  from  1  oz  to  1|  oz.  upon  13  oz.  This  fact  is  very  instructive,  anU 
shows  that  the  goods  had  been  dressed  in  the  loom,  or  imbued  subsequently,  with  some 
very  deliquescent  pasty  matter. 

2.  I  next  subjected  the  piece  to  the  action  of  distilled  water,  at  a  boiling  tempera- 
ture, till  the  whole  glutinous  matter  was  extracted  ;  five  pints  of  water  were  employed 
for  this  purpose,  the  fifth  being  used  in  rinsing  out  the  residuum.  The  liquid  wrung 
out  from  the  silk  was  evaporated  first  over  the  fire,  but  toward  the  end  over  a  steam 
bath,  till  it  became  a  dry  extract;  which  in  the  damaged  pieces  was  black, like  extract" 
of  liquorice,  but  in  the  sound  pieces  was  brown.  In  all  cases  the  extract  so  obtained 
absorbed  moisture  with  great  avidity.  The  extract  was  weighed  in  its  driest  slate,  and 
the  weight  noted,  which  showed  the  addition  made,  by  the  dressing  to  the  weight  of 
the  silk.  The  piece  of  silk  was  occasionally  weighed  in  its  cleansed  state,  when  dry, 
as  a  check  upon  the  preceding  experiment. 

3.  The  dry  extract  was  now  subjected  to  a  regular  chemical  analysis,  which  was 
mollified  according  to  circumsUnces,  as  follows :  100  parts  of  it  were  carefully  igni/ 
ted  in  a  platinum  capsule ;  during  which  a  considerable  flame  and  fetid  smoke  were 
disengaged.  The  ashes  or  incombustible  residuum  were  examined  by  the  action  of  dis- 
tilled water,  filtration,  as  also  by  that  of  acids,  and  other  chemical  tests,  whereby  thc 
constituents  of  these  ashes  were  ascertained.  In  the  course  of  the  incineration  or  cal- 
cination of  the  extract  from  the  several  samples,  I  never  observed  any  sparkling  or 
scintillation ;  whence  I  inferred  that  no  nitre  ha4  been  used  in  the  dressing  of  the 
goods,  as  some  persons  suggested. 


614 


SILK. 


Wing  minute  course  of  researches,  in  order  to  discover  whether  the  urine  of  man  had 

of"the"rd'«tlct  In  alcoholTo^  ''''''  f  ^'^  ^"^^  T^'  '  ^^'^  ^^^  aTrtlTortioa 
ot  the  said  extract  m  alcohol,  60  per  cent,  over  proof,  which  is  incapable  of  dissolvine 

the  nee  water  or  other  starchy  matter,  which  might  be  properly  appM  ?o  the  sHk  ?f 
the  loom.    The  alcohol,  however,  especially  when  aided  by  a  moderate  hear^^^^^^ 

of  tZnTrin:  "ThrrlolTf  "^  ^r^'  "'^^\^^  ^^'  characteristic  constituti^ 
01  numan  urine.     The  alcohol  took  a  yellow  tint,  and  being,  after  subsidpnop  nf  thp 

lt^Z^\fA"%'i  '^'"  f  ^"^^  ^  ^^^^^  '^^«^'  and 'exposed  to^hTgentle  hea^of  a  w^^^ 
nn»  ^^^^ Vk  '^'"^^  ''■^'  ^i^*'  '^*°  ^^«  receiver,  and  left  a  residuum  in  the  retort  which 
hpft  n?99noV'''P^''''  ''^^'^^'.  ^^''  ^"^«^^^^^  ^^«  ««lid  when  cold,  Wt  mehed  at  a 
heat  of  220^  F.;  and  at  a  heat  of  about  245^  it  decomposed  with  the  producUon  of  wa 

Tir.L'^^^'^^V^  ammonia-the  well-known  products  of  urea  at  S^fmpei^^ture' 
lan.fp,^  w^K''^*°^^"^^7^'  ^"^  ^^'^^^"^  ^«  the  smell,  and  was  made^S  ariy 
manifest  by  its  browning  yellow  turmeric  paper,  exposed  in  a  moist  state  to  the  fump/ 

^ffectTd^TttusTbt '•'  T' V^^'^.?^^^  ^'^'  ^^  -^-h  th^  decomVoshion'wL  uta^'; 
ettected.     I  thus  obtained  perfect  evidence  that  urine  had  been  employed  in  India  in 

KnwiT  '^'  P^'"  ""  '^  ^i^'^  ^  ^^^^t  °^«^y  «^  th«  pieces  had  beenX  sed  it  S 
known  to  every  experienced  chemist,  that  one  of  the  most  fermentative  or  pitrefai 

TtllhT^'^''^^'  ''^''^  "^^  ^'  °^^^^'  ^^«^t«  fr«°»  the  mixture  of  humL  urfne  w^^^ 
starchy  or  gummy  matter,  such  as  rice  water ;  a  substance  which,  by  the  test  of  iodine 

ne'^n^cSn^^retusr^^^^^''  "  '  ^'^"^'  ^°  ^^^  ^^"^^^^  present?l\^^rvtt  ' 
5.  On  incinerating  the  extract  of  the  Corahs,  I  obtained,  in  the  residuum  »  nnt«Kio 

Z^Vj.f  ''T  "'^"'^  S7^^^''  ^y  ^h*'  ^^«t  of  chloride  of  plaCm,prov^^^^^^      potS 
But,  as  the  extract  itself  was  neutral  to  the  tests  of  litmus  and  turmeric  naneri™ 

D?Z?pTh?tw'  ^'^^??"'  '5*^  ^^^  ^^tract  contained  some  vegetaT  acTprobnZ 
produced  by  the  fermentation  of  the  weaver's  dressing,  in  the  hot  climate  of  HiEan 
Lnl  i?t'v  ^^^'  examined  the  nature  of  this  acid,  by  distilling  a  portbn  of  the  extraci 
along  witv  some  very  dilute  sulphuric  acid,  and  obtained  in  the  receiver  a  notablp 
quantity  of  the  volatilized  acid  condensed.  This  acid  might  be  the  acelic  Cvinelarl 
the  result  of  fermentation,  or  it  might  be  the  formic  orTcId  of  ants  the  result  of  ThP 
;fi;n?pf '"\P^"::L'  ^^'^  ^P.^^  ^^^^^^y  ^^"er.  to  decide  this  pLt^lUturated  the  saM 
m,  "  ?/''.^'''^r  "^^g'^^^}^' a°d  obtained  on  evaporaUon  the  characteri  tic  gum^^^ 
mass  of  acetate  of  magnesia,  soluble  in  alcohol,  but  none  of  the  cnstals  of  forn^X  of 

froT  thP  Nn°'"^"^\'  '^  *l'"^'-    ^'""^  the  quantity  of  alkali  (p^tSa  whkh"^^^ 
from  the  incineration  of  the  extract  of  one  piece  of  the  damaged  silk  and  whioh 

ZZffZ  '^-  r'^'V  ^""^^  ^  ^"^  ^^•^^^"^^'l  that  wood  astThad  be^n  addl^  n 
India,  to  the  mix  ure  of  sour  rice  water  and  urine,  which  would  therefore  constitute  a 
compound  remarkably  hygrometric,  and  well  qualified  to  keep  the  wa%  of  the  web 

t"kintTpon^t     Thi'tTr^^^  ^'^  '^^^  ^^«*  the  Tantyo?  weaver™ 

m«fr!?  r   P        \     .,  *^^tate  of  potassa,  present  in  the  said  Corahs,  is  one  of  thP 
most  deliquescent  salts  known  to  the  chemist :  and,  when  mixed  with  femented  urine 
^JZ^T"^  ^'^''''  hygrometric  dressing-one,  likewise,  which  wUl  readUy  generate 

6.  That  the  dressing  applied  to  the  webs  is  not  simolv  a  dPP«nt.««  «r    •       v 
very  manifest,  by  comparing  the  incinerated  res  dCrnVrice  w'^^^^^ 
siduum  of  the  extract  of  the  said  Corahs.     I  find  that  100  CTainTnf  tl  *?"?^^^ted  re- 
a  platinum  capsule,  leave  only  about  one  fifth  of  a  Jain  ?r  ifn  ^on  ^f  •  "'"T^'^i" 
matter,  which  is  chiefly  silicious  sand;  whereas  when  100^ Jn.    r     «^^^<^«°^bustible 
of  several  of  these  Corihs  were  similariy  incSerthey  feft  nlT^r  ""''"'* 

busUb  e  matter.  This  consisted  chiefly  of  alumina  or  S  of  clavUIh^i-'  ""^  '"'^°'' 
and  a  litUe  common  or  culinary  salt.  (Has  the  cUbe^n  added  ^n,-^''^'''''- ^^^S?'** 
Chester,  to  give  apparent  substance  to  the  thin  siJk  leb  ?)  '    '  "  ^''''^  '^  ^*^- 

staXuringtp'eVoforf^u^^^^^^^^^^  f  w^^uT^^^' 4i^  ^^^-^  -  ^^-ost  con- 
J^e  of  the  sai'd  go'ods  had  bee\'  -rasionerby'Th^e'vU^^  ^  the  dam, 

them  in  India;  which, as  I  have  said  under  thpJfl,  ^'^essing  which  had  been  put  into 
them  to  become  more  or  lesr^ldeTed^n  nrnnLr  ?'!u^^^  ^^^^  ^^^  ^''^  ^""^  ^^"^ed 
packed  at  Calcutta,  and  to  thraSal  iH^^^  ^  "^'^  ^"^'-"^^  ^^°^P°^««  ^^^^ 
ring  the  voyage  from  Calcutta  toLSon  ^^''''  "^  atmospheric  au:  into  the  cases  du. 

The  following  is  the  list  of  Corahs  which  I  chemically  examined  :- 


SILK. 


615 


1  and  2,  per  Colonic,  from  Calcutta,  2  pieces,  sound. — ^These  two  pieces  had  been 
dressed  with  a  sweet  viscid  matter,  like  jaggery  or  goor  (molassy  sugar),  mixed  with 
the  rice  water.  This  extract  contained  no  urine,  but  emitted  a  smell  of  caramel  or 
burned  sugar,  when  ignited.  It  amounted  to  270  grains  in  the  one,  and  370  in  the 
other. 

3,  ditto,  1  piece,  mildewed,  1st  degree. — ^This  piece  had  been  dressed  like  No.  5,  and 
contained  no  trace  of  urine.  It  aflbrded  400  grains  of  a  most  deliquescent  sweetish 
glutinous  matter. 

4,  ditto,  1  piece,  mildewed,  1st  degree,  as  No.  3. 

5,  ditto,  1  piece,  mildewed,  3d  degree. — This  piece  contained  no  trace  of  urine,  but  it 
afforded  210  grains  of  a  light  brown  extract,  being  rice  water,  mixed  with  something 
like  jaggery. 

6,  ditto,  1  piece,  3d  degree,  mildewed. — This  piece  aflbrded  evidence  of  urine  in  it, 
by  test  of  carbonate  of  ammonia.    The  extract  amounted  to  320  grains. 

8,  ditto,  2  pieces,  damaged  in  the  3d  degree. — The  total  weight  of  one  of  these  pie- 
ces, after  exposure  to  air,  was  4,610  grains,  and  it  lost  440  grains  by  drjing.  The  total 
weight  of  the  other  was  4,950  grains,  and  it  lost  320  grains  by  drying.  The  weight  of 
extract  was,  in  one  piece,  210  grains ;  and  both  pieces  contained  abundant  traces  of 
urine,  as  well  as  of  potash.  These  constituents,  along  with  the  rice  water,  accounted 
sufliciently  for  the  great  damage  of  these  two  pieces  by  mildew. 

10,  ditto,  2  pieces,  sound. — These  contained  no  urea.  Each  afl"orded  from  300  to 
600  grains  of  a  light  brown  vegetable  extract. 

12,  ditto,  2  pieces. — The  extract  in  the  one  amounted  to  222  grains,  and  in  the  other 
to  330.    Both  contained  urea,  and  had,  therefore,  been  imbued  with  urine. 

14,  ditto,  2  pieces,  mildewed,  3d  degree. — There  was  no  urea  in  the  extracts  from 
these  two  pieces ;  but  they  aflforded,  the  one  300  grains  of  extract,  and  the  other  750. 
But  this  extract  was  a  saccharine  molassy  matter,  impossible  to  dry  over  a  steam  heat. 
The  same  quantity  as  the  last,  if  dried  by  stronger  means,  would  have  weighed  proba- 
bly 600  grains.  Its  extraordinary  deliquescence  kept  the  pieces  very  moist,  and  there- 
by caused  the  mildewing  of  them.  With  the  saccharine  matter,  four  per  cent,  of  culi- 
nary salt  was  mixed  in  one  of  these  extracts. 

16,  ditto,  2  pieces,  3d  degree  of  mildew. — ^The  extract,  about  200  grains,  contained 
abun  'ant  evidence  of  urea,  and,  consequently  of  urine. 

18,  ditto,  2  pieces,  sound. — Both  these  contained  some  traces  ot  urea ;  but  the  one 
yielded  only  102  grains  of  extract,  and  the  other  370  grains.  They  must  have  been 
well  screened  from  the  air  to  have  resisted  the  action  of  the  urine. 

20,  ditto,  2  pieces,  damaged,  1st  degree. — No  urea.  The  extract  of  the  one  was  320 
grains ;  of  the  other  piece  380 ;  and  it  had  a  light  brown  color,  being  a  sacchanne 
mucilage. 

22,  ditto,  2  pieces,  3d  degree  mildew. — 200  grains  of  extract  in  the  one,  and  210  io 
the  other :  they  contained  urea. 

24,  2  pieces,  3d  degree  of  mildew. — 310  grains  of  extract  in  the  one,  and  180  grains 
in  the  other.     Both  were  impregnated  with  urea,  and  consequently  with  urine. 

Having  in  the  preceding  report  demonstrated,  by  the  clearest  processes  of  chemical 
research,  that  the  above  mildewed  Corahs  had  been  damaged  by  the  fermentative  de- 
composition of  the  dressing  paste  with  which  they  had  been  so  abundantly  impregnated, 
I  would  recommend  tne  importers  of  such  goods  to  cause  the  whole  of  the  dressing  to 
be  washeJ  out  of  them,  and  the  pieces  to  be  thoroughly  dried,  before  being  packed  up. 
I  believe  that  clean  silk  may  be  kept  and  transported,  even  in  the  most  humid  atmo- 
sphere, without  undergoing  any  change,  if  it  be  not  imbued  with  fermentative  paste. 

I  examined  eight  other  pieces  of  a  different  mark,  imported  by  another  mercantQe 
house,. per  Colonist,  and  they  afforded  results  similar  to  the  above. 

The  beautiful  and  artistic  silk  trophy,  occupying  the  entrance  to  the  "Western  Nave 
of  the  Exhibition,  did  not  fail  to  attract  notice.  This  trophy  consisted  of  an  elegant 
arrangement  of  rich  tissues,  brocades,  damasks,  and  other  fumitm'e,  silks,  the  whole 
of  ■which  had  been  manufactured  by  Messrs.  Keith  &  Co.,  and  was  surmounted  by  a 
silken  banner.  A  variety  of  rich  and  costly  productions  of  the  Spitalfields  loom  were 
exhibited  in  the  Galleries. 

The  colours  and  textures  of  these  fabrics  were  of  great  brilliancy  and  finish.  An  in- 
teresting collection  of  specimens  of  the  raw  and  manufactured  material  was  also  exhibited 
Specimens  of  silk-plush  for  various  purposes  and  in  imitation  of  furs  were  likewise  found 
among  these  articles.  The  ribands  of  Coventry^  have  acquired  a  universal  reputation  ;  and 
this  characteristic  manufacture  was  well  represented  in  the  number  and  variety  of  the 
articles  exhibited.  The  application  of  steam  power  as  a  substitute  for  hand-weaving 
in  this  manufacture  is  making  rapid  progress,  and  some  of  its  results  were  apparent. 

At  present  the  United  Kingdom  draws  its  supply  of  the  raw  material  for  manufac- 
ture principally  from  the  East   Indies;    and  France,  Italy,  Turkey,  and   China,  also- 


616 


SILK. 


liii 


m 


! 


this  vase  quantity  of  textill  fibJTis  the  r^uU  of  rte  J^Z'tA  «"«°''>e.r<>d  that  aU 
guned  of  the  importance  of  things  seemingly  in°  igJUfirnt    "^      ^*'  ""  '**  "^^  ** 
Manchester  exhibited  Gros  de  Nanles  a<?  o-nnrl  an,i  oo  «u 

:?d^t^^^ftTatt^er'»'-'-^"^^ 

the^s^^ts^-ofihis^^^rn  srrrutirro/ -i"  *tLrrn  1^^  ^K' 

^r^fm'^r?!  raises  "4oSt?r3er.;r  r 'S?r  -^" «- 

cheap,  enabling  the  manufacturer  to  sell  at  a  v^rv  lot  ratJ^  Thl  ^^""^  ]'  extremely 
manufacturers  of  this  canton  employ  their  own  can  taT  anHhoIo  ^/^'P*^  P^*"*  «^  *^^ 
difficulties   and  disadvantages  iLeparaWe  frorfht  p^  "iVl  ^^''^^^unt  those 

The   medium   annual  prodL  of  t^he   manuSure^   o^^lST'- ^  of  borrowed  capital. 

Btrikes  and  coalitions  so  inSu%  tr„,he^mZf«TP''^^" '",''•  ^^P'^y*""' ""^  the 

daS:,  Id  ™sV?eSaSre&h!tZ  Sifflff'""''  "i'"™.'  *"«  ""  "^  P™'-"™ 
tive  cisterns,  instead  of  telngVretudttalhaveS^^^^^^^^  '•"  ^'S^  prohibi- 

genius  and  emulation  of  the  nlam^faw  fr.~  ?„S  •  j  •"''T**?*'  ^^  '""easing  the  active 
Bore  favourable  outW,  for  tCr  ijfor  Tif "  ^tV"^  "■""  '»  ''^^  """•«  a'"*"'  »"<« 
edge  of  the  Swiss  marbeLnsldeS^it  K.  •  "7??'^'  '"=*"'"y  """I  ""n-nercial  knowl- 
brSnch  of  trade        ^       eous.dered  the  baas  of  the.r  success  in  this  most  important 

the*fo;t^±,S-3up^y  •„f''snk'''^etS"Xi  'oV  t"'*"""  r-T'-y  P---* 
important  scale  in  theSbardn  V.ni?^L'?-    ^  "^  "'.''  '*  inducted  on  the  most 

*he%yro.:  thesam'e\t;trtlr  Iried'  f^^^^^^^ 

cocoons  amount  on  an  averse  aunuauj^  '"■  *"''  ^"""•''^    The  productions  of 


In  Lombardy 

The  p>-ovince  of  Venice 

The  Tyrol      - 

The  other  provinces  - 


to  250,000  cwt 
200,000 
28,000 
12,000 


Or,  in  round  numbers,  500,000  cwt.  ^""^^  ^^^'^^^  *'^*- 

The  cocoons  are  prepared  at  the  reeling  establishment  into  raw  sHkr     FrnT«  f>,  i* 

of  mquines,  it  wou  d  appear  that  Lombardy  comprises  sofioTp!^?;  ^V\^  ""^^^ 
which  employ  79  500  workneonlp  wWlim^fVoi?  '^°™P"^^^  ^'06')  reehng  establisliments, 
ments,  whIchVre  noi  taSd'^L^Ws  enumeratto"^"^^^^^  the  smaller  establish-' 

8,612  000  Vienna  lbs. ;  and  sinc^  12  lirof  c^t^^VieU  iTh  „f  P'-'>^"«'»\'»n<'"nts  to 
qmred  for  this  aggregate  of  raw  silk  3(X)4(K)cwrof  S„„  meZ„7^  "j""  ""  "" 
qnired  ,n  e^ess  of  the  quantity  produced,  an  excS  of  LarivSn^f^"^""'' '^' 
^w';?rt'"=*'°"  <?'""=  ^^•''''^'^  P--"«'.  d.iefl;ty  that  rf^emna  -  "  "'™"'*' 

<*Tess  ei\P"TTe"'  "'  ^f"'-  ''^  '^".""S  -'«W-hments  are  p"eV  numerous  but' 
tw  less  extent.     The  nearest  approximation  in  reference  tn  thi^  J^,,**^  .""'"^'^P"^,  wit 

taking  the  extent  of  the  production  at  one-haff  of  Zt  in  LoX^d^     T^  *^'°'^ 
of  the  cocoons  produced  in  the  province  undprL  fnlff       J^ombardj     The  remainder 
partly  in  the  Ty^rol  also  wl^stT^^r  fo^o;^^^^^^^^  ^"  ^f^^\'y^  ««d 

wen  as  in  Istria,  are  prepared  in  Venetian  reeHng  estaSLnta^^^^  """^  '^'"^''^'"'  "^ 

The  number  and  the  performance  of  the  reelin|  mach  nes^n  th;  Tv^nl  „ 
known.     In  the  year  1848  South  Tvrol  r^nf-Jir.^^   -^r?    f       ,    ®  ^^^^^^  "'"®  accurately 

These  employed^8.00o"nd:!lI':n"doTtl65  70o1Ctf"'^^"^nrV""'^^^ 
Vienna  cwt.  of  cocoons.    The  suddIv  of  cocno™  ™ '      j  v     "'Z?^  »''k  from  31,900 

production  Of  the  countiy  was  Z^!fflThrVe  Sr^ro^^f^^^^  ^'^^  '""^'^'^^  ^^  ^^ 
^"^^f^^rnststfvTnliaT^^^^^^^^^^^  P-inces  ^"cV conjointly  from  10,000' 

n.  the  reeling  establishments  is  not  less  t^n  wTo^lf  l^^rm^'f^^^^^^^^^ 


SILK. 

reduced  to  270  days  in  the  year,  80,000  only).  Besides  the  products  already  enumerated 
about  900  cwt  of  cocoons  are  annually  imported  into  Lombardy,  principally  from 
Switzerland,  and  the  neighbouring  Italian  States,  and  are  prepared  in  the  Lombardy 
reeling  establishments.  The  quantity  of  silk  produced  is  thus  increased  to  an  aggregate 
of  4,116,200  lbs. 

TTie  raw  silk  undergoes  further  preparation  in  the  throwing  mills,  but  the  whole 
mass  of  the  production  is  not  thus  worked  up  within  the  monarchy,  for  the  exports  of 
raw  silk  are  found  considerably  to  exceed  the  imports.  On  an  average  of  the  five  years 
1843  to  1847,  the  annual  imports  were  110,000  Vienna  lbs.  of  raw  silk  (through  Venice, 
Switzerland,  and  the  adjacent  Italian  States),  whilst  70,000  lbs.  of  this  commodity  were 
exported,  for  the  most  part  to  Switzerland,  the  adjacent  states  of  Italy,  and  Southern 
Germany.  Hence  it  results  that  a  balance  of  raw  silk,  amounting  to  689,000  lbs.,  have 
been  taken  off  by  foreign  consumption,  and  that  the  other  3,518,800  Vienna  lbs.  are  re- 
tained by  the  states  of  the  monarchy,  and  more  than  two-thirds  thereof  are  worked  up 
in  Lombardy.  In  1817,  that  province  reckoned  500  throwing  mills,  with  1,239,000 
spindles ;  and  of  these  702,100  were  for  spinning,  and  507,209  for  twisting.  In  the 
throwing  mills  themselves,  12,000  hands  were  employed,  (namely,  4,400  men,  5,500 
women,  and  2,100  children,)  and,  moreover,  there  were  occupied  31,800  female  winders. 
The  production  yielded  was  989,000  Vienna  lbs.  of  tram,  and  1,189,700  lbs.  of  thrown 
silk ;  for  this  aggregate  of  production  2,256,200  lbs.  of  raw  silk  were  used.  The  floss 
eilk  was  to  the  weight  of  76,000  lbs. 

The  working  of  the  throwing  •  mills  of  Venice  produced,  in  proportion  to  those  of 
Lombardy,  almost  similar  results  to  those  above  indicated  in  reference  to  the  reeling 
establishments;  only  the  production  of  tram  greatly  preponderates.  The  number  of 
persons  employed  in  the  throwing  mills,  both  within  and  without  doors,  were  20,000 ; 
their  production  was  above  960,000  Vienna  lbs.,  and  the  consumption  of  raw  eilk  by  the 
cmiversion  into  this  quantity  was  1,009,000  lbs.,  giving  waste  (floss)  to  the  amount  of 
47,400  lbs. 

There  are  at  present  in  the  Tyrol  55  throwing  mills,  with  125,047  spindles;  85,583 
of  which  latter  are  for  spinning,  and  89,464  for  twisting.  In  these  mills  500  men  and 
1,200  women  and  children  are  employed.  Tlie  production  there,  including  that  of  the 
smaller  throwing  mills,  which  give  occupation  to  500  workmen,  amount  to  220,400 
Vienna  lbs.  of  thrown  eilk,  for  which  231,400  Vienna  lbs.  of  raw  silk  have  to  be 
worked  up. 

Of  the  remainder  of  the  raw  silk  (28,200  lbs.)  about  14,000  lbs.  are  distributed 
through  the  other  southern  provinces,  and  the  remaining  9,200  lbs.  appropriated  to  other 
purposes. 

Thus  we  find  a  resulting  total  of  production  equal  to  3,874,000  Vienna  Iba  of  thrown 
silk. 

Silk  in  the  Exhibition, — Sitnpson,  Miles,  5,  Aldermanburi/  Postern,  4,  Milk  Street,  Man- 
chaster,  Leek,  and  Derby. — Manufacturer.  Specimens  of  the  leading  classes  of  raw  silks, 
from  France,  Italy,  China,  Bengal,  and  Turkey,  selected  by  Messrs.  Durant  &  Co. 

Sewing,  netting  silk,  and  twist,  intended  to  show  the  varieties  of  quality,  their  rich- 
ness and  beauty  of  colour. 

Sewing,  netting  silk  and  twist. 

Raven  and  jet  sewings,  in  weight  and  form  as  sold  in  the  market,  of  four  qualities. 

Crochet  and  Mohair  silks,  exhibited  for  quality  and  price. 

Shoe  mercery,  consisting  of  silk  and  union  galloons,  doubels,  braids,  and  round  silk 
laces,  yellow  and  black  borders,  <fec.    Specimens  of  union  cord. 

In  1849,  the  enormous  quantity  of  6,269,179  lbs.  of  silk  in  its  several  conditions  of 
raw,  waste,  and  thrown,  was  imported  into  this  country.  The  manufacture  employe 
upwards  of  33,000  individuals,  and  is  caiTied  on  in  nearly  300  silk  factories.  The  sum 
annually  expended  on  silk  goods  in  England  is  taken  at  considerably  upwards  of  fifteen 
millions  annually. 

In  the  following  Table  are  included 


ISM. 

1851. 

Importa  to  Liverpool  of        -       -       - 
Stocks  at  Liverpool,  31st  December     - 
Also,  exporta  us  "  Consumption" 

lbs.                                   lb.. 
China         121,218           R'ngul      34.6M) 
Do.              6.-,:04              Do.           1,950 
Raw  SUk  600,786     Thrown  Silk  66  618 

lbs.                                   lbs. 

China        16«.-;70          B<>ni^       6,410 

Do.               2.650              Do.          none. 

Raw  Silk  48-2,643     Thrown  Silk  66,560 

The  Imports  warehoused  in  December  were — 

China    -        -  1,877  bales       Bengal          -  1,262  bales      Chinese  Thrown  20  bales 

Italian  Raw  -     204                Brutia           -       86                 Persian       -        -  858 

Italian  Thrown    107                 Greek  -        -         6                 Canton       -        -  1414 
Of  tlie  above,  237  bales  China  were  at  the  port  of  Liverpool 


B!  ■  I 


n  ;'i!! 


618 


SILK. 


An  Account  of  the  Imports,  Consumption,  and  Stock  of  Silb:  in  1860  and  1851. 


Deieription. 

Imports 
1850. 

Imports 
I85I. 

Kxtreme 

Prices 

during 

1850. 

Extreme 
Prices 
during 
1851. 

Consump- 
tion. 
1850. 

CoDsiunp- 
tion. 
1851. 

Stock 

aisc  Dec. 

1850. 

Stock 

3Ut  Dec. 

1851. 

Prices 

1st  JiUI. 
1851. 

1 

Prices 

1st  Jan. 

1859. 

CHINA—* 

Ts^ttlee 

Tuyssam 

Coiitun 

Chin  Chew 

Thrown 
BENGAL      " 
BRHTIA 
PERSIAN 
GREEK 
SYRIAN 

riAUAN— 
Raw 

Thrown 

lbs. 
1,325,082 
611,836 

llu,16ij 

ll.8;« 

66.:84 

1,510,350 

443,410 

210,435 

21.15U 

1,140 

629,300 
440,800 

lbs. 

1,219,488 

621,810 

361,119 

32,088 

56  000 

1,233,810 

186,600 

226,950 

13,200 

10,850 

562.310 
363,080 

«.  d.     t.d. 

14  6®22  0 
9  6     n  6 
8  6      13  9 

15  0       8  0 

16  6      19  6 
5  6      19  6 

11  0      18  0 

8  6     11  0 

13  0     21  0 

20  9      26  0 

16  0     28  6 
18  6     31  0 

«.  d.     i.d. 

14  6®  22  0 

10  0     11  6 
10     14  0 

4  6       10 

15  6      18  6 

5  0      19  0 

11  0      18  0 

8  6    no 

12  0     21  0 

18  9      22  0 

11  0     28  6 

19  0     80  6 

lbs. 

1,453,500 

423.198 

311.2 

21,248 

21,198 

1.393.050 

394.040 

253,650 

23.100 

1,140 

699.480 
542,o00 

lbs. 

1,238,994 

691.182 

282,401 

40.606 

61,160 

1,25^,340 

216,0 '0 

289.500 

13.650 

10,850 

631.130 
41)6,580 

lU. 

681.156 

301,134 

19,9- .8 

11,424 

31.856 

1,000.350 

113.600 

18.000 

4,500 

none 

306. Sio 

159,5(10 

Ibi. 

191,660 

9;n,16;i 

165,286 

2.85A 

26,096 
981,ShO 

94.300 

15,450 
4,1)50 
none 

232,000 
U6,000 

t.  d.    #.  d, 

18  6@22  0 

19  0      116 
10      18  6 
56       80 

18  0      18  6 
5  6      19  0 

13  0      10  0 
90      106 

14  0     21  0 
00     000 

19  0     28  6 
19  6     30  6 

*.d.    I.d. 

16  0@20  0 

10  6      16  6 

8  6      14  0 

60       10 

18  0       — 
6  0     16  0 

116     18  0 

96      11  0 

12  6      19  6 

21  0      32  0 

200     96  0 

19  0     99  0 

Total. 

6,383,3^9 

4,969,915 

5,280,226 

5,213,593 

2,180,908 

2,521,230 

•_« 


Average  net  weight  of  »  bale  of  Bengal  150  lbs. ;  China  Raw  102  lbs. ;  Chinese  Thrown  119  lbs 

Italian  V90  lbs. ;  and  a  ballot  of  Pertiao  15  Ibe. 


Brutia  300  lbs. ; 


•  Ist  January  1851- 
du.  1859 


-The  Stock  of  China  of  1,118.138  lbs.  is  estim.-»fed  at  119,112  lbs.  sold,  and  33^966  lbs.  unsold, 
do.  do.  1,153,650  lbs.  964,128  lbs.  198|922  lb*. 


la  the  Import  of  Brutia  are  included  19,260  lb.  of  a  superior  sort,  from  19*.  6rf  to  91*  M 

do.       Chm  Chew  are  included    6,080       ofKohratsilk  4     a  —     * 

do.  do.  do.         9,600       of  China  Tusah  6     0  — 


Unsold  8,460  Iba. 
do.        none. 
do.       none. 


An  Estimate  of  the  Annual  Quantities  of  Silk  produced  or  exported  from  the  several 
Countries  in  the  World,  exhibiting  also  the  Countries  to  which  exported. 

iVb^c— These  estimates  exclude  the  silk  manufactured  in  Italy. 


Countries  whence  exported. 


Italy  exports  -  -  .  . 
France  produces  -  -  . 
India  and  Bengal  export 
Persia  " 

China  " 

Asia  Minor  " 

Levant,  Turkey,  and  Ar- 
chipelago  export    -    - 
Spain  " 

Total    .    - 


Quantities. 


« 


(    n^  kils.,  or 

(  128^  Vienna  lbs. 

162  lbs.  English. 


34,000  bales  of  225  small  lbs. 
10,500 

9,500 

7,500 

4,000 

3,500 

8,500 
1,500 


Countries  to 
which  exported. 


74,000  bales. 


)  England  - 
5  France  -  - 
Prussia  -  - 
Russia  -  . 
Austria   and 

Germany 
Switzerland 

Total      - 


Qnantitiee. 


Bales. 

28,000 

22,000 

7,600 

6,400 

5,000 

6,000 
74"^" 


State  of  the  "Warehouses  in  London,  ending  December  31,  1850  and  1851. 


Bengal  ...... 

"  Liverpool  ... 
China 

"  Liverpool  -  .  . 
Canton 

"  Liverpool  ... 
Chinese  Thrown  .... 

"        Liverpool       ... 

Total      - 

*  Included  in  China,  but  the  quan- 
tity very  small. 

Sold  Stock. 

Unsold  Stock. 

1 

Delivered  in  Dec. 

1850. 

1851. 

1850. 

1851. 

1850. 

1851. 

Bales. 
4,286 

7,376 

• 
» 

234 

Bales. 
3,067 

7,698 

25 

1,134 

233 

Bales. 

2,3W 

13 

3.157 

52 

• 

lo4 

Bales. 
3,715 

1,675 

232 

Bales. 
683 

1,542 

* 

32 

Bales. 
608 

1,752 

92 

185 

138 

11,896 

12,157 

5,696 

5,622 

2,257 

2,775 

snx 


619 


Average  Monthly  Deliveries  from  the  Warehouses  in  London,  from  Ist  Jan.  to  Slst  Dec 
xn  the  Years  1849,  1850,  and  1851  (including  Liverpool). 


Bengal  -  -  - 
China  -  -  . 
China  Thrown 


1849. 


715  Bales  per  Month 
72     "  " 

46     "  " 


1850. 


780  Bales  per  Month 
1608     "  " 

81     "  " 


1851. 


718  Bales  per  Month 
1784     "  « 

60     "  ** 


The  following  is  an 

Account  of  the  Exports  of  Silk  of  British  Produce  and  Manufacture. 


Quantities. 

Declared  Value. 

1850. 

1861. 

1860. 

185L 

Manufactures  of  silk  only : — 
Stuffs,  handkerchiefs, 

and  ribbons  ....  lbs. 

Stockings doz.  pair 

All  other  descriptions    -  value 
Of  silk  mixed  with  other 

materials : — 
Stuffs,  handkerchiefs, 

and  ribbons .    -    -    -  lbs. 

Stockings doz.  pair 

All  other  descriptions   -  value 

419,366 
12,269 

766,358 
4,143 

436,301 
15,986 

748,694 
4,971 

£ 
487,450 
20,261 
174,879 

832,140 

8,153 

23,102 

£ 
534,418 
26,557 
194,987 

847,886 

4,651 

26,432 

Total      ....... 

Silk  thrown     ....  lbs. 

Silk  twiat  and  yam  .    .  lbs. 

69,993 
474,349 

72,460 
389,901 

1,040,985 

63,278 

161,883 

1,134,931 

67,803 

138,685 

Total 

• 

. 

1,255,641 

1,881,369 

V.  *  ,1^  .  ^yT,  for  angling,  is  made  as  follows  .--Select  a  number  of  the 
best  and  largest  silkworms,  just  when  they  are  beginning  to  spin;  which  is  known  by 
their  refusing  to  eat,  and  havmg  a  fine  silk  thread  hangbg  from  their  mouthi 
Immerse  them  m  strong  vinegar,  and  cover  them  closely  for  twelve  hours,  if  the 
weather  be  warm,  but  two  or  three  hours  longer,  if  it  be  6ooL    When  taken  ou    tod 


1268 


(XSIimilQD  ^^SBfiHElID 


/  / 


0 o 

o  u 

o- .a 

O o 


/ 
/ 

y 
/I 


/ 


/ 


\ 

\ 


s 


=7Nk 


s. 


pulled  asunder,  two  transparent  guts  will  be  observed,  of  a  yellow  green  colour  aa  fhlr-V 
a.  a  small  straw,  bent  double.    The  rest  of  the  entr'aUs  reCbTes^Sfled  sp^^^ 
therefore  can  occasion  no  mistake  as  to  the  silk-gut.    If  this  be  soft,  or  break  u^n 


I 


i  .    , 


620 


SILVER 


i  i 


stretdiing  it.  it  w  a  pm>f  that  the  worm  has  not  been  long  enough  under  the  influence  of 
the  vinegar  When  the  gut  18  fit  to  draw  out.  the  end  of  it  fa  to  be  dipped  into  the 
vinegar,  and  the  other  end  is  to  be  stretched  gently  to  the  proper  length^^When  thus 
?n'ni.^,"in  fhf  "ni  ^^  f  ^K^^  '^^f  ^'^.  ^^  a  thin  piece  of  boarcf  by  putting  its  extremities 
n^rv     Tl!«l!n  •        u  "^T^' ""'  ^'•^"o"^  ^^^'V^  P'°''  ^"^  ^hen  exjosed  in  the  sun 

iLZ'd.  I!p  X«    "^  '  ^"^f  "  ""^^^  '"  ^Pf  °-     ^'•^"^  ^^  °^*°°^^  i"  ^hict  it  is  dried, 
the  ends  are  always  more  or.  less  compressed  or  attenuated.*    Fia.  1268  a  is  the  silk- 

Z^t'^n'L    Vf'^  *T°  ^r^"'  '.  ^'  ''  *^^  ^"^' '  ^  ^'  *  ^^^^  «"t  ^t  the  ends,  with  th. 
^oTrVrS^'  Z'-^'  ^^^"^^  ^'^^  wooden  pegs,  for  the  same  purpose. 

blLVER  (Argent,  Fr. ;  /Si/6er.  Germ. ;)  was  formerly  called  a  perfect  metal  because 
heat  alone  revived  its  oxide,  and  because  it  could  pass  unchangoj  through  fiery  tS 
which  apparently  destroyed  most  other  metals,  the  distinctions,  perfect  ir^perfec?' 
and  noble,  are  now  justly  rejected.    The  bodies  of  this  class  are  all  equal  in  nSuc 

wh,Vh^'^'\^T^  ""^"^"^  merely  with  different  relations  to  otlier  forms  of  mluen 
which  serve  to  characterize  it,  and  to  give  it  a  peculiar  value.  ' 

\yhen  pure  and  planished,  silver  is  the  brightest  of  the  metals.     Its  specific  cravitv 
in  the  ingot  is  10-47  ;  but,  when  condensed  under  the  hammer  or  !n  the  coining  pfe^H 
^Trcp  vf     ^Tt^''  ^l  ^  ^"^^^  '"^  ^'^'^  "  temperature  estimated  by  somf  a's  eq^ii 
L    «^-  f  f.^'^-,^'^^  ^y  «^^^^s  to  22°  Wedgewood.    It  is  exceedingly  malleable  and  Zt^ 

h^ufl^u'  "''  °^''  '''"  tWo  0  0  ^^  ^  ^"^^  ^^^^^'  «"d  ^^^  f^  fi»er  than  a 

W«^'J.;  r  ■  ^  '  i'""  *^^*  '^J^^'  ^fl  '"termediate  strength  between  these  two  metals. 
.!^^  T^^"*"  ^''  ^^''^^  """t  affect  silver,  but  that  of  houses  impregnated  with  sulrhurl 
eted  hydrogen,  soon  tarnishes  it  with  a  film  of  brown  sulphuret.  It  is  distinguished 
^iZhfrlZ^  f '  r*^'  platinum  by  its  ready  solubility  in  nitric  acid,  and  frolJl'aW 
all  other  metals,  by  its  sahne  solutions  affording  a  curdy  precipitate  with  a  most  minute 
quantity  of  sea  salt,  or  any  soluble  chloride.  /  f       i^      c  wim  a  most  minute 

Silver  occurs  under  many  forms  in  nature  : — 

J.  Native  silver  possesses  the  greater  part  of  the  fcbove  properties;  yet,  on  account  of 
Its  being^more  or  less  alloyed  with  other  metals,  it  diff-ers  a  litUe  in  malkabiUty Tstre 
pnli'^'^'J""-,  Jt/«°^^tim^s  occurs  crystallized  in  wedge-form  octahedrons,  ncub^? 
^^J}'^^^^^^/ons.  At  other  times  it  is  found  in  dendritic  shapes,  or  arWescence? 
resulting  from  minute  crystals  implanted  upon  each  other.  But  more  usually  it  preS 
Inagnimde        ^'''"'  ''"^'"'  determinable  form,  or  in  amorphous  masses  of  wfoul 

The  gar/gtt«  (mineral  matrices)  of  native  silver  are  so  numerous,  that  it  may  be  said 

S  nS  '"  ^"  .^'"^'  °^  '^'^'•.  ^^  T".'^^  ''  "PP^«^^  ^^  i^  filtered'  into  thdrfissures; 
at  another  as  having  vegetated  on  their  surface,  and  at  a  third,  as  if  impasted  in  thS 
substance.  Such  varieties  are  met  with  principally  in  the  mines  of  Peru 
fh«t  nf^T^Un®  metal  is  found  in  almost  all  the  sUver  mines  now  worked;  but  especially  ia 
that  of  Kongsberg  in  Norway,  m  carbonate  and  fluate  of  lime,  &c. ;  at  Schl^genl^£ 
m  Siberia,  m  a  sulphate  of  baryles;  at  Allemont,  in  a  ferruginous  clay,  &c.i^ljf 
article  Mines,  I  have  mentioned  several  large  masses  of  native  silver  that  have  been 
discovered  m  various  localities.  i*iai  imvc  u^r 

The  metals  most  usually  associated  with  silver  in  the  native  alloy  are  cold  conner 
arsenic,  and  iron.  At  Andreasberg  and  Guadalcanal  it  is  alloyed  with  about  5  ner  J^? 
of  arsenic.    The  auriferous  native  silver  is  the  rarest ;  it  has  I  brals-Jeffow  coW       ^ 

2.  ^nhnjoniaZ  «/rer.-This  rare  ore  is  yellowish-blue ;  destitute  of  malleability  •  even 
very  brittle;  spec.  grav.  9-5.     It  melts  before  the  blowpipe,  and  afl-ords  whhe  fumeso? 
o^de  of  antmiony ;  being  readily  distinguished  from  arsenical  iron  anTarsenicayTobalt 
antimoir  '"^'  ""^  ^^'^  ^^  ^"^  ^  ""^  '^^^''  «"^  from  24  to  16  of 

3.  Mixed  aniimonial  saver.^At  the  blowpipe  it  emits  a  strong  garlic  smell     Its  con 

4.  Sulphuret  0/  stlver.^This  is  an  opaque  substance,  of  a  dark-gray  or  leaden  hue- 
•hghUy  malleable,  and  easily  cut  with  a  knife.  wL.;i  it'  betrays  a  meSbc  lustre     The 

bl7xplHrn[-Tr87  aJe?h  T'T    "  """^^^  ''^  ''  ''  sulphur  ?o  89  of  silver 
Dy  experiment  ,  13  to  87  are  the  theoretic  proportions.    Its  spec.  grav.  is  69     It  occurs 

cjTstallized  m  most  sdver  mine«,  but  especially  in  thoee  of  Frefberg  Jo^himsthd  " 
Bohemia,  Scheranitz  in  Hungary,  and  Mexico.  J'  "^'^>  ^oacnimstnai  m 

86^of1uver^^^"''^  '•^"^'"''''  '^^"^  ^^'^'-^^  «Pec.  gray,  is  6-7.  It  contains  from  84  to 

i'i^;.f'';?'^T/"''^*f*^*'r..V'''-*  *»*^f  ^'~It9  constituents  are,  lead  36,  bismuth  27   silver 
15,  sulphur  16,  with  a  httle  iron  and  copper.    It  ia  rare.  "'»"*uia  ^<,  aiiver 

•  Nobb's  Art  of  Trolling. 


SILVER. 


621 


7.  ^niimoniated  sulphuret  of  stiver,  the  red  silver  of  many  mineralogists,  is  an  ore 
remarkable  for  its  lustre,  color,  and  the  vanety  of  its  forms.  It  is  friable,  easily 
scraped  by  the  knife,  and  affords  a  powder  of  a  lively  crimson  red.  Its  color  in  mass 
is  brilliant  red,  dark  red,  or  even  metallic  reddish-black.  Jt  crystallizes  in  a  variety  of 
forms.  Its  constituents  are, — silver  from  56  to  32 ;  antimony  from  16  to  20  ;  sulphur 
from  11  to  14 ;  and  oxygen  from  8  to  10.  The  antimony  being  in  the  state  of  a  purple 
oxyde  in  this  ore,  is  reckoned  to  be  its  coloring  ))rinciple.  It  is  found  in  almost  all 
silver  mines;  but  principally  in  those  of  I'reyberg,  Sainte-Marie-aux- Mines,  and  Gua- 
dalcanal. 

8.  Black  sulphuret  of  silver,  is  blackish,  brittle,  cellular,  affording  globules  of  silver 
at  the  blowpipe.  It  is  found  only  in  certain  mines,  at  Allemont,  Freyberg ;  more  abun- 
dantly in  the  silver  mines  of  Peru  and  Mexico.    The  Spaniards  call  it  iiegrillo. 

..  9.  Chloride  of  silver,  or  horn  silver. — In  consequence  of  its  semi-transparent  aspect,  its 
'Yellowish  or  greenish  color,  and  such  softness  that  it  may  be  cut  with  the  nail,  this  ore 
has  been  compared  to  horn,  and  may  be  easily  recognised.  It  melts  at  the  flame  of  a 
candle,  and  may  be  reduced  when  heated  along  with  iron  or  black  flux,  which  are 
distinctive  characters.  It  is  seldom  crystallized ;  but  occurs  chiefly  in  irregular  forms, 
sometimes  covering  the  native  silver  as  with  a  thick  crust,  as  in  Peru  and  Mexico.  Its 
density  is  only  4*74. 

Chloride  of  silver  sometimes  contains  60  or  70  per  cent,  of  clay ;  and  is  then  called 
butter-milk  ore,  by  the  German  miners.  The  blowpipe  causes  globules  of  silver  to  sweat 
out  of  it.  This  ore  is  rather  rare.  It  occurs  in  the  mines  of  Potosi,  of  Annaberg,  Frey- 
berg, AIMmont,  Schlangenberg,  in  Siberia,  &c. 

Mix  1  part  ot  it,  with  1  o!  powdered  charcoal,  and  2  of  nitre,  and  project  the  mixture 
fapidl^  i»  small  successive  portions  into  a  redhot  crucible,  and  maintain  the  fused  metal 
in  ignition  for  a  quarter  of  an  hour. 

10.  Carbonate  of  silver,  a  species  little  known,  has  been  found  hitherto  only  in  tht 
mine  of  S.  Wenceslas^  near  Wolfache. 

Table  of  the  Quantities  of  Silver  brought  into  the  Market  every  year,  on  an  average, 

from  1790  to  1802. 


Old  Continent. 

Lbs.  Avoird. 

New  Continent. 

Lbs.  AToird. 

ASIA. 

Siberia    - 

. 

38,500 

Central  America  - 

1,320,000 

EUROPE. 

Hunarary 

. 

44,000 

South  America     - 

605,000 

Austrian  States  - 

. 

11,000 

Hartz  and  Hessia 

• 

11,000 

Saxony   - 

. 

22,000 

Norway  - 

- 

22,000 

Sweden  - 

-) 

France  - 

-> 

11,000 

Spain      -            -            - ) 
Total  of  the  Old  Continent 

Total  of  the  New  Continent 

159,500 

1,925,000 

Thus  the  New  Continent  furnished  twelve  times  more  silver  than  the  old.  For  more 
detailed  statistics  of  silver,  see  the  end  of  the  article. 
The  following  is  Mr.  Ward's  description  of  the  treatment  of  silver  ores  in  Mexico:— 
"  After  returning  from  San  Augustin,"  says  he,  "  I  passed  the  whole  of  the  after 
noon  at  the  hacienda  (melallurgic  works)  of  Salgado,  in  which  the  ores  of  the  Valenciana 
mine  are  reduced.  The  hacienda,  of  which  a  representation  is  given  below,  fg.  1001, 
contains  forty-two  crushing-mills,  called  arrastres,  and  thirty-six  stampers.  The  ore, 
on  being  extracted  from  the  mine,  is  placed  in  the  hands  of  the  pepenadores,  men  and 
women,  who  break  all  the  larger  pieces  with  hammers,  and  after  rejecting  those  in 
which  no  metallic  particles  are  contained,  divide  the  rest  into  three  classes"  (inferior, 
middling,  and  rich).  "These  are  submitted  to  the  action  of  the  morteros  (stamps), 
one  of  which,  of  eight  stampers,  is  capable  of  reducing  to  powder  ten  cargas  of  ore  (each 
of  350  lbs.)  in  twenty-four  hours.  This  powder  not  being  thought  sufficiently  fine  for 
the  quicksilver  to  act  upon  with  proper  effect,  it  is  transferred  from  the  morteros  to  the 
arra^tres  (crushing-mills,  see  wood-cut),  in  which  water  is  used.  Each  of  these 
reduces  to  a  fine  impalpable  metalliferous  mud,  six  quintals  (600  lbs.)  of   powder  in 


!'  X 


622 


SILVER. 


24  hours.  At  Guknajuato,  where  water-power  cannot  be  obtained,  the  arrastrea 
are  worked  by  mules  (see  yi^  1001),  which  are  kept  constantly  in  mot  on  a^T^Iow 
pace,  and  are  changed  every  6  hours  The  grinding-stones,  as  well  as  the  sides  ^d 
bottom  of  the  mni  itself,  are  composed  of  granite;  four  blocks  of  which  revolve  in 
each  crushmg-mill,  attached  to  cross-bars  of  wood.  This  part  of  the  operation  is  thought 
of  great  importance,  for  it  is  upon  the  perfection  of  the  grinding  that  the  sav  n-  of  fhe 
quicks.lver  is  supposed  in  a  great  measure  to  depend,  in  the  subsequent  amal  "amation! 
The  |rmd.ng  is  performed  usually  in  a  covered  shed  or  gallery,  which  in  a  lar^e  Aa"S 


1269 


The  Gallera  of  the  Hacienda  of  Salgado, 


in  C^Si^*^  T  J?Jr^"*  1  ^^^r"^^  ^""'^^"^  apparatus  used  at  the  lavaderos,  or  gold  washings, 
m  Chile.     The  streamlet  of  water  conveyed  to  the  hut  of  the  gold  washer,  is  received  upon 

a  large  rude  stone,  whose  flat  sur- 
face  has  been  hollowed  out  into  a 
shallow  basin,  and  in  the  same 
manner  into  3  or  4  others  in  suc- 
cession ;  the  auriferous  particles 
are  thus  allowed  to  deposite  them- 
selves in  these  receptacles,  while 
the    lighter    earthy    atoms,  still 

.bom  three  feet  in  diameter,  \u^i\.^^^^,f'^-?^Tlf:^^'''^''^"'""'  ^""' 
spherical  boulder  of  syenitic  eranite  alSjut  twn  r^..  ■  /  ^^V  ?'""*  '*  "  '"«* 
i«rt  two  iron  Dlii»q  flT.H  ™„    ".  i'  .      l-v  •'"'  '"  d'ameter,  havinij  on  its  upper 

^^r^'hTrirn^'^!  lttxr^^^ZT^vc::f,'t\ !""""?  °^  ""'^' »  ^t"- 

Ihe  extremities  of  this  lever,  work  it  ud  andTwn  =i?  ,  (°*'  '""^ '  '""  '"'^"  '^^'^  '"' 
rollin"  motion  whi^h  !.»,;?[:!!•.  I     "^     u      T"  ^"erna'elv,  so  as  to  give  to  the  stone  a 

?he' washes lh"s,?ord!trsl:cS      tZ'^.V"'  "r^  """•"""'  ^"""^  '•■'"•™',''  "i 
3  ucu  ucAieriiy ,   ana  it  there  were  much  gold  to  be  separated,  it 


SILVER. 


623 


1271 


would  afford  very  profitable  employment;  but  generally  the  small  quantity  collected  is 
sufficient  only  to  afford  subsistence  to  a  few  miserable  families. 

The  trapichCj  ingenio,  or  mill,  for  grinding  the  ores  of  silver,  is  a  verj-  simple  piece  of 
mechanism.  A  place  is  chosen  where  a  small  current  of  water,  whose  section  wiU 
present  a  surface  of  six  inches  diameter,  can  be  brought  to  a  spot  where  it  can  fall  per- 
pendiculariy  ten  or  twelve  feet;  at  this  place  a  well  is  built  of  this  depth,  about  6  feet 
in  diameter ;  m  its  centre  is  fixed  an  upright  shaft,  upon  a  central  brass  pin  ;  it  is  con- 
fined above  by  a  wooden  collar.  A  little  above  its  foot,  the  shaft  has  a  small  wheel  affix- 
cd  to  It,  round  which  are  fixed  a  number  of  radiating  spokes,  shaped  at  the  end  somewhat 
like  cups,  and  forming  altogether  a  horizontal  wheel,  four  feet  in  diameter.  Upon  the 
slanting  edges  of  the  cups,  the  water  is  made  to  strike  with  the  force  it  has  acquired  in 
felling  down  a  neariy  perpendicular  trough,  scooped  out  of  the  solid  trunk  of  a  tree 
This  impression  makes  the  wheel  turn  with  a  quick  rotatory  motion.  The  upri'^ht  axis 
rises  about  6  feet  above  the  top  of  the  well,  at  about  half  which  heisbt  is  inserted^  small 
horizontal  arm,  four  feet  long,  which  serves  as  an  axle  to  a  ponderous  mi.  -stone  of  granite 
of  from  four  to  six  feet  diameter,  which  is  made  to  roll  on  its  edge  in  a  circular  trough! 
somt»limes  made  of  the  same  material,  and  sometimes  of  hard  wood. 

The  weight  of  this  quickly  roUing  stone  effects  the  pulverization  of  the  ore.  In  some 
cases.  It  is  taken  out  in  the  dry  state,  and  sifted  ;  but  more  generally  the  separation  of 
tfee  finely  ground  particles  is  accomplished  by  the  action  of  running  water.  For  this 
pjrpose  a  small  stream  is  made  to  trickle  into  the  circular  trough,  by  which  the 
jounded  ore  is  worked  up  into  a  muddy  consistence,  and  the  finer  particles  flow  off  with 
lie  excess  of  water,  through  a  notch  cut  in  the  margin  of  the  trough.  This  fine  matter 
-»  received  m  little  pools,  where  tjie  pounded  ore  is  left  to  settle ;   and  the  clear  water 

being  run  off,  the  powder  is  re 
moved  from  the  bottom,  and  car 
ried  to  the  place  of  amalgamation. 

The  ingeniosy  or  stamping-mills, 
are  driven  by  a  small  breast  water 
wheel,  of  five   feet  diameter,  and 
one    foot    broad.     Fig.    1003   will 
give  a  sufl5cient  idea  of  their  con- 
struction.      The    long    horizontal 
shaft,  fixed  on  the  axis  of  the  wheel, 
is  furnished  with  5  or  6  cams  placed 
at  different   situations    round     the 
shaft,  so  as  to  act  in  succession  on 
the  projecting  teeth  of  the  upright 
rods    or    pestles.     Each   of  these 
weighs  200  pounds,  and  works  in  a 
corresponding    oblong    mortar    of 
stone  or  wood. 

The  ;>a<io,  or  amalgamation  floor,  Jig.  1272,  is  a  large  flat  space,  open  to  the  sky, 
312  feet  m  length,  by  236  m  breadth,  and  securely  surrounded  by  strong  walls.     It  i| 

^-''^  paved    with    large    un- 

hewn blocks  of  porphy- 
ry, and  is  capable  of 
containing  24  tortas^  or 
flat  circular  collections 
oftama,  of  about  50  feet 
diameter,  and  7  inches 
deep,  when  the  patio  is 
not  filled,  (but  of  some- 
what smaller  dimensions 
when  nearly  so,)  ranged 
in  4  rows,  and  numbered 

Z\,  ofone-^o'-tl-/-""  '^"-'^^--"^  -  aP-  for  theX^VS-rnlX 

The  following  description  of  Mexican  amalgamation  is  given  by  Cantain  Lvon. 
T  ^v  ?*5  ^.^^^^^'^^^  *=°"^*'"s  «0  '"onions  of  20  quintals  each,  and  is  thus  formed : - 
In  the  first  instance,  a  square  space  of  the  requisite  size  for  a  torta,  is  marked  out,  and 
enclosed  by  a  number  of  rough  planks  which  are  propped  in  their  places  on  the  patio 
floor  by  large  stones  and  dried  horse-dung  and  dust  are  piled  round  their  ed^es  to  ™ 
vent  the  escape  of  the  lama  A  heap  of  saltierra  (salt  mixed  with  earthy  impurities)  is 
rTi?  .r  f"*""^'  V}t  P^T^^'^"^  «f  2  fanegas  (each  =  1-6  En-lish  bushels)  and 
1  half  to  the  monton,  =  150  for  the  torta.    After  this,  the  lama,  or  ore  ground  into  a 


i^ 


I  i 


I 


> 


Tm     f 


624 


SILVER. 


fine  paste,  is  poured  in.  When  the  last  or  6Uth  monton  is  delivered,  the  saltierrait 
shovelled  down  and  well  mixed  with  the  lama,  by  treading  it  with  horses,  and  turning  it 
•  with  shovels ;  after  which  the  preparation  is  left  at  rest  for  the  remainder  of  the  day.  Ob 
the  following  day  comes  the  el  incorporo.  After  about  one  hour's  treading  by  horses,  the 
magistral  or  roasted  and  pulverized  copper  ore  is  mixed  with  the  lama*  (the  repaso  or 
ireading-mill  still  continuing,)  in  summer  in  the  proportion  of  15  cargas  of  12  arrobas 
(25  lbs.  each)  to  the  torta,  if  the  ore  be  of  6  marcs  to  the  monton,  and  in  winter  in  only  half 
the  quantity.  For  it  is  a  sinrrular  fact,  that  in  summer  the  mixturr  cools,  and  equires 
more  warmth;  while  in  \  r.Ler  it  acquires  of  itself  ad'iiior  !  heat.  With  jiooier  ores, 
as  for  instance  those  ol  4  marcs  to  the  monton,  12  carg;i>  uio  applied  in  summer,  and  6 
m  wmter.  From  November  to  February,  lime  is  also  occasionally  used  to  cool  the  lama, 
m  the  proportion  of  about  a  peck  per  monton. 

The  repaso,  or  treading  out,  is  continued  by  six  horses,  which  are  guided  by  one  man, 
who  stands  in  the  lama,  and  directs  them  all  by  holding  all  their  long  halters.  This 
operation  is  much  more  eflectual  in  a  morning  than  an  evening,  and  occupies  about  five 
or  six  hours.  When  the  magistral  is  well  mixed,  the  quicksilver  is  applied  by  being 
sprinkled  through  pieces  of  coarse  cloth  doubled  up  like  a  bag,  so  that  it  spurts  out  in 
very  minute  particles.  The  second  treading  of  the  horses  then  follows;  after  which  the 
whole  mixture  is  turned  over  by  six  men  with  wooden  shovels,  who  perform  the  opera- 
tion m  an  hour.  The  torta  is  then  smoothed  and  left  at  rest  for  one  entire  day,  to  allow 
the  incorporation  to  take  place.  It  unaergoes  the  turning  by  shovels  and  treading  by 
horses  every  other  day,  until  the  amalgamator  ascertains  that  the  first  admixture  of  quick. 
„  silver  is  found  to  be  all  taken  up  by  the  silver ;  and  this  he  does  by  vanning  or  washing 
a  small  quantity  of  the  torta  in  a  little  bowl.  A  new  supply  is  then  added,  and  when 
this  has  done  its  duty,  another  is  applied  to  catch  any  stray  particles  of  silver.  On  the 
same  day,  after  a  good  repaso,  the  torta  is  removed  on  hand-barrows  by  the  laborers,  to 
the  lavaderosy  in  order  that  it  may  receive  its  final  cleansins.  The  general  method  of 
proportioning  the  quicksilver  to  the  tortas,  is  by  allowing  that  every  marco  of  silver 
which  is  promised  by  trial  of  the  ores  as  the  probable  produce  of  a  monton,  will  require 
in  the  whole  process  4  lbs. 

In  metals  of  five  to  six  marcs  and  a  half  per  monton  (of  the  average  richness  of  Zacate- 
cas),  16  lbs.  of  quicksilver  were  incorporated  for  every  monton,  =  900  lbs.  for  the  torta. 
On  the  day  of  the  second  addition,  the  proportion  is  5  lbs.  the  monton ;  and  when  the 
torta  IS  ready  to  receive  the  last  dose  of  quicksilver,  it  is  applied  at  the  rate  of  7  lbs. 
the  monton,  =  420  lbs. ;  making  a  total  of  1620  lbs.  of  quicksilver.  With  poorer  ores, 
less  quicksilver  and  less  magistral  are  required. 

^  The  usual  time  for  the  completion  of  the  process  of  amalgamation,  is  from  12  to  19 
days  m  the  summer,  and  20  to  25  in  the  winter.  This  is  less  than  a  third  of  the  time 
taken  at  some  other  mines  in  Mexico.  This  rapidity  is  owing  to  the  tortas  being  spread 
very  flat,  and  receiving  thereby  the  stronger  influence  of  the  sun.  In  the  Mexican  mines, 
only  one  monton  is  commonly  mbced  at  a  time ;  and  the  lama  is  then  piled  in  a  small 
conical  heap  or  monton. 

Lavadero,  or  washing  m^.— Here  the  prepared  tortas  are  washed,  in  order  to  carry  off 
the  earthy  matters,  and  favor  the  deposition  of  the  amalgam  at  the  bottom.  Each  vat  is 
about  8  feet  deep,  and  9  in  diameter;  and  solidly  built  in  masonry. 

A  large  horizontal  wheel,  worked  by  mules,  drives  a  vertical  one,  which  turns  a  horU 
Eontal  wheel  fitted  round  a  perpendicular  wooden  shaft,  revolving  upon  an  iron  pivot  at 
the  bottom  of  the  vat.  To  the  lower  end  of  this  shaft,  four  cross-beams  are  fitted,  from 
which  long  wooden  teeth  rise  to  the  height  of  5  fetU  Their  motion  through  the  water 
being  rapid,  keeps  all  the  lighter  particles  afloat,  while  the  heavier  sink  to  the  bottom. 
Ihe  large  wheel  is  worked  by  four  mules,  two  at  each  extremity  of  the  cross-beam. 
Water  is  supplied  from  an  elevated  tank.  It  requires  12  hours'  work  of  one  tub  to  wash 
a  torta.  Eight  porters  are  employed  in  carrying  the  prepared  lama  of  the  torta  in  hand- 
barrows  to  the  vats.    The  earthy  matter  receives  a  second  washin<'. 

The  amalgam  is  carried  in  bowls  into  the  azoguena,  where  it  is'subjected  to  straining 
tbrough  the  strong  canvass  bottom  of  a  leather  bag.     The  hard  mass  left  in  the  bag  is 

12*1^3  moulded  into  wedge-shaped  masses  of  30 

lbs.,  which  are  arranged  in  the  burning- 
house,  ( /ig.  1273),  to  the  number  of  JI, 
upon  a  solid  copper  stand,  called  hasOy  hav- 
ing a  round  hole  in  its  centre.  Over  this 
row  of  wedges  several  others  are  built ;  and 
th  e  whole  pile  is  called  pina.  Each  circu- 
lar range  is  firmly  bound  round  with  a  rope. 
The  base  is  placed  over  a  pipe  which 
,      .       ,         .  ,   .,  ,.   ,  .  Jeads  to  a  small  tank  of  water  for  con- 

di'nsmg  the  quicksilver;  a  cylindrical  space  being  left  in  the  middle  of  theptna,  to  give 
btt  egress  to  the  mercurial  vapors. 


SILVER. 


625 


A  large  bell-shaped  cover,  called  capellina,  is  now  hoisted  up,  and  carefully  .owered 
over  the  pina,  by  means  of  pulleys.  A  strong  lute  of  ashes,  saltierra,  and  lama  is  applied 
to  its  lower  edge,  and  made  to  fit  very  closely  to  the  plate  on  which  the  base  stands. 
A  wall  of  fire-bricks  is  then  built  loosely  round  the  capellina,  and  this  space  is  filled 
with  burning  charcoal,  which  is  thrice  replenished,  to  keep  it  burning  all  night.  After 
the  heat  has  been  applied  20  hours,  the  bricks  and  ashes  are  removed,  the  luting  broken, 
and  the  capellina  hoisted  up.  The  burned  silver  is  then  found  in  a  hard  mass,  which  is 
broken  up,  weighed,  and  carried  to  the  casting-house,  to  be  formed  into  bars  of  about  1080 
ounces  each.  The  loss  of  silver  in  burning  is  about  5  ounces  to  each  bar  (barra),  and 
the  loss  of  quicksilver,  from  2|  upon  the  good  metals,  to  9  upon  the  coarse. 

Molina  told  Mr.  Miers,  that  the  produce  of  the  galena  ores  of  Uspaltata  did  not  average 
more  than  2  marcs  per  caxon  of  5000  lbs.,  which  is  an  excessively  poor  ore.  The  argen- 
tiferous galena  ores  of  Cumberland  afford  11  marcs  per  caxon  ;  while  tlie  average  produce 
of  the  Potosi  silver  ores  is  only  5  or  6  marcs  in  the  same  quantity.  These  comparisons  afibrd 
the  clearest  evidence  that  the  English  mode  of  smelling  can  never  be  brought  into  com 
petition  with  the  process  of  amalgamation  as  practised  in  America. 

Humboldt,  Gay  Lussac,  Boussingault,  Karsten,  and  several  other  chemists  of  note, 
have  offered  solutions  of  the  amalgamation  enigma  of  Mexico  and  Peru.  The  following 
seems  to  be  the  most  probable  rationale  of  the  successive  steps  of  the  process : — 

The  addition  of  the  magistral  (powder  of  the  roasted  copper  pyrites),  is  not  for  the 
purpose  of  disengaging  muriatic  acid  from  the  sea  salt  {saltierra),  as  has  ^^een  supposed, 
since  nothing  of  the  kind  actually  takes  place;  but,  by  reciprocal  or  compound  affinity, 
is  serves  to  fbrm  chloride  of  copper,  and  chloride  of  iron,  upon  the  one  hand,  and  sulphate 
of  soda,  upon  the  other.  Were  sulphuric  acid  to  be  a«««l  instead  of  the  magistral,  as 
certain  novices  have  prescribed,  it  would  certainly  prove  injurious,  by  causing  muriatic 
acJJ  to  exhale.  Since  the  ores  contain  only  at  times  oxyde  of  silver,  but  always  a  great 
abundance  of  oxyde  of  iron,  the  acid  would  carry  off  both  partly,  but  leave  the  chloride  of 
silver  in  a  freer  state.  A  magistral,  such  as  sulphate  of  iron,  which  is  not  in  a  condition 
to  generate  the  chlorides,  will  not  suit  the  present  purpose  ;  only  such  metallic  sulphates 
are  useful  as  are  ready  to  be  transformed  into  chlorides  by  the  saltierra.  This  is  pe- 
culiarly the  case  with  sulphate  of  copper.  Its  deuto-chloride  gives  up  chlorine  to  the 
silver,  becomes  in  consequence  a  protochloride,  while  the  chloride  of  silver,  thus  formed, 
is  revived,  and  amalgamated  with  the  quicksilver  present,  by  electro-chemical  agency 
which  is  excited  by  the  saline  menstruum;  just  as  the  voltaic  pile  of  copper  and  silver  is 
rendered  active  by  a  solution  of  sea  salt.  A  portion  of  chloride  of  mercuiy  will  be  simul- 
taneously formed,  to  be  decomposed  in  its  turn  by  the  sulphate  of  silver  resulting  from 
the  mutual  action  of  the  acidified  pyrites,  and  the  silver  or  its  oxyde  in  the  ore.  An 
addition  of  quicklime  counteracts  the  injurious  efl'ect  of  too  much  magistral,  by  decom- 
posing the  resulting  sulphate  of  copper.  Quicksilver  being  an  excellent  conductor  of 
heat,  when  introduced  in  too  great  quantities,  is  apt  to  cool  the  mass  too  much,  aad  thereby 
enfeebles  the  operation  of  the  deuto-chloride  of  copper  upon  the  silver. 

There  is  a  method  of  extracting  silver  from  its  ores  by  what  is  called  imhibitum.  This 
is  exceedingly  simple,  consisting  in  depriving,  as  far  as  possible,  the  silver  of  its  gangue, 
then  melting  it  with  about  its  own  weight  of  lead.  The  alloy  thus  procured,  contains 
from  30  to  35  per  cent,  of  silver,  which  is  separated  by  cupellation  on  the  great  scale,  as 
described  under  ores  of  lead.  In  this  way  the  silver  is  obtained  at  Kongsberg  in  Norway. 
The  amalgamation  works  at  Halsbriicke,  near  Freyberg,  for  the  treatment  of  silver  ores 
by  mercury,  have  been  justly  admired  as  a  model  of  arrangement,  convenience,  and  regu- 
larity;  and  I  shall  conclude  this  subject  with  a  sketch  of  their  general  distribution. 
Fig,  1274  presents  a  vertical  section  of  this  great  tisine  or  hiittemverk,  subdivided  into 

1274 


5.        y./-A/- 


^^^^^^'''^^i^mm 


four  main  departments.    The  first,  a,  b,  is  devoted  to  the  preparation  and  roasting  of  Ae 
matters  intended  for  amalgamation.    The  second,  b,  c,  is  occupied  with  two  successive 


626 


SILVER. 


p.ra.us  is  placed,  where  ii.el^"Z.MyVi.'eJ'  '^""''  "'  "-  ""^  ■"='"""«  "^ 

chambers  of  sublimaK  4  /  r     ^^^'^^>.^^  ^^«  calcmmg  area.     Above  the  furnace  ar« 
thp^fin«  *''^  *^ivision  B,  c,  we  have  rf,  the  floor  for  the  coarse  siftin«'  •  beneath  that  fnr 

At  D  th.  rr.n!.  .,     J    r   ^   ■■  "'".'^  ''™''' '"  ""^  transported  to  the  amaJsamation  casks, 

Sinner  iron  l!^ A  7  'TT^^  u^fx"  (ppeissglanzsilber),  bismuth,  sulphurets  of  arsen'l 
ih^f^th  '  :  r^  ^''?^^^'  ''°^'*^^>'  ^^"<^*  w^^h  several  earthy  m  nerals.  It  is  essentS 
!£a  h^v""'''  *^**'  amalgamated  shall  contain  a  certain  proporSn  of  silphur  In  order 
that  they  may  decompose  enough  of  sea  salt  in  the  roast  n-  to  di4n4  "e  as  mnrh 
chlorine  as  to  convert  all  the  silver  present  into  a  chloride  Wit!  ths^ew  ores  no^r 
ThP  n^r"n  T  TA^  ""''^  .'^^^"  ^''^^  ^'^  "<^^^^'  ^o  make  upa  detemSe  avem^e 
HelZlCm^lLZZ  ^i?  ''^■'?'"^'  '\''  rectangular  heap',  aboutTr  efls  lonTa'nd 
hJ^I  r        ?,  ^  n  ^      .  ^^^  ^^^'    a"^  "PO'^  tJ^at  layer  the  requisite  quantitv  of  salt  i^  }Jt 

4SS^L'rof'rre'"Vhe7:an'^^^        %"^"'^"- 1""^^  •'  ''  '^'-  ofsalttlif,  aTlott  d  t'o 
mast  be  ihPn  will  1^    ^J^ap  being  made  up  with  alternate  strata  to  the  desired  magnitude 

from  3Mo  dLw^  T^'  ^""^  ^T"^  ^"'°  ?"'"".  *^'"^^'  ^«"^^  ro«,^po,/,,  weighing  each 
^VbylhrPri^^^^^^^^^^  ^'  ^''  ^'  Halsbrucke^  6000  cwts.^,  it  iS 

Ihe^Te  n?s^lt^7?hf '"'''T  ^^^*— ^he  furnaces  appropriated  to  the  roasting  of 
ine  ore-posts  are  of  the  reverberatory  class,  prov  ded  with  soot  chambers  Th^v  .rl 
built  up  alongside  of  the  bed-Jioor,  and  connected  with  i^  b^  a   br  ck    unnd     Vh^ 

fuTr^rivrthen^thi^^^^^^^^  n^rV^^  helnSfandSwi^htcesJan 

lurmn^  over ,  men  the  hre  is  raised  so  as  to  kindle  the  sulphur,  and  keen  the  nrp  rpdhnt 

I^d  w^r  re  Sd'Thl  d'^^f  i''"^; '""  -5i^-^-y -^^^^^^ 

fl«m7    Thf/   exhaled.    The  desulphuration  next  begins,  with  the  appearance  of  a  blue 

m^s  is  Jmoerv  ?u7nef  n'''''  ''T'  t'""^^  ^'^^^  ^"^^  ^^^^^'^^  is  kept  up ;  and  he 
^l^L  w!  ^  turned  over,  m  order  to  present  new  surfaces,  and  to  prevent  anv 
^king.  Whenever  sulphurous  acid  ceases  to  be  formed,  the  finishin^^calcinat^on  is^J 
be  commenced  with  increased  firing ;  the  object  being  now  to  decompose  thesea  salt  b? 
means  of  the  metallic  sulphates  that  have  been  generated,  to  converT?hem  into  ebbtides' 

iml^he  Vrfs  tXX'^^^^^^  T»^^  stirring  isl'becoSS 

of  m„HrH?li  Tk-^  ^^*'*''  ""*  ^°"^^''  betray  the  smell  of  sulphurous,  but  only 

of  muna  ic  acid  gas.     This  roasting  stage  lasts  commonly  three  quarters  of  an  hour 
13  or  14  furnaces  are  worked  at  the  same  time  at  Halsbrucke  j   and  each  turns  out  in  a 


SILVER. 


627 


week  5  tons  upon  an  average.  Out  of  the  nichi  chambers  or  soot  vaults  of  the  furnaces, 
from  96  to  100  cwts.  of  ore-dust  are  obtained,  containing  32  marcs  (16  lbs.)  of  silver. 
This  dust  is  to  be  treated  like  unroasted  ore.  The  fuel  of  the  first  fire  is  pitcoal ;  of  the 
finishiag  one,  fir-wood.  Of  the  former  115^^  cubic  feet,  and  of  the  latter,  294^,  are,  upon 
an  average,  consumed  for  every  100  cwts.  of  ore. 

During  the  last  roasting,  the  ore  increases  in  bulk  by  one  fourth,  becomes  in  conse* 
quence  a  lighter  powder,  and  of  a  brown  color.  When  this  process  is  completed,  the  ore 
is  raked  out  upon  the  stone  pavement,  allowed  to  cool,  then  screened  in  close  sieve-boxes, 
in  order  to  separate  the  finer  powder  from  the  lumps.  These  are  to  be  bruised,  mixed 
with  sea  salt,  and  subjected  to  another  calcination.  The  finer  powder  alone  is  taken  lo 
the  millstones,  of  which  there  are  14  pairs  in  the  establishment.  The  stones  are  of  gra- 
nite, and  make  from  100  to  120  revolutions  per  minute.  The  roasted  ore,  after  it  has 
passed  through  the  bolter  of  the  mill,  must  be  t£  impalpable  as  the  finest  flour. 

The  Amalgamation. — This  (the  verquicken)  is  performed  in  20  horizontal  casks, 
arranged  in  4  rows,  each  turning  upon  a  shaft  which  passes  through  its  axis ;  and  all 
driven  by  the  water-wheel  shown  in  the  middle  of  ^g.  1006.  The  ca^s  are  2  feet  10 
inches  long,  2  feet  8  inches  wide,  inside  measure,  and  are  provided  with  iron  ends.  The 
staves  are  3|  inches  thick,  and  are  bound  together  with  iron  hoops.  They  have  a  double 
bung-hole,  one  formed  within  the  other,  secured  by  an  iron  plug  fastened  with  screws. 
They  are  filled  by  means  of  a  wooden  spout  terminated  by  a  canvass  hose ;  through 
which  10  cwts.  of  the  bolted  ore-flour  (erzmehl)  are  introduced  after  3  cwts.  of  watei 
have  been  poured  in.  To  this  mixture,  from  |  to  |  of  a  cwt.  of  pieces  of  iron,  l^  inch 
square,  and  |  thick,  are  added.  When  these  pieces  get  dissolved,  they  are  replaced  by 
others  from  time  to  time.  The  casks  being  two  thirds  full,  are  set  to  revc^ve  for  If  or 
2  hours,  till  the  ore-powder  and  water  become  a  uniform  pap ;  when  5  cwts.  of  Quicb> 
silver  are  poured  into  each  of  them.  The  casks  being  again  made  tight,  are  put  in  gear 
with  the  driving  machinery,  and  kept  constantly  revolving  for  14  or  16  hours,  at  the  rate 
of  20  or  22  turns  in  the  minute.  During  this  time  they  are  twice  stopped  and  opened,  in 
order  to  see  whether  the  pap  be  of  the  proper  consistence ;  for  if  too  thick,  the  globules 
of  quicksilver  do  not  readily  combine  with  the  particles  of  ore ;  and  if  too  thin,  they 
fall  and  rest  at  the  bottom.  In  the  first  case,  some  water  must  be  added  ;  in  the  second, 
some  ore.  During  the  rotation,  the  temperature  rises,  so  that  even  in  winter  it  some- 
times stands  so  high  as  104®  F. 

The  chemical  changes  which  occur  in  the  casks  are  the  following : — The  metallic 
chlorides  present  in  the  roasted  ore  are  decomposed  by  the  iron,  whence  results  muriate 
of  iron,  whilst  the  deutochloride  of  copper  is  reduced  partly  to  protochloride,  and  partly 
to  metallic  copper,  which  throw  down  metallic  silver.  The  mercury  dissolves  the  silver, 
copper,  lead,  antimony,  into  a  complex  amalgam.  If  the  iron  is  not  present  in  sufficient 
quantity,  or  if  it  has  not  been  worked  with  the  ore  long  enough  to  convert  the  copper 
deutochloride  into  a  protochloride,  previously  to  the  addition  of  the  mercury,  more  or  less 
of  the  last  metal  will  be  wasted  by  its  conversion  into  protochloride  (calomel.)  The 
water  holds  in  solution  sulphate  of  soda,  undecomposed  sea  salt,  with  chlorides  of  iron, 
manganese,  &c. 

As  soon  as  the  revivification  is  complete,  the  casks  must  be  filled  with  water,  set  to 
revolve  slowly  (about  6  or  8  times  in  the  minute),  whereby  in  the  course  of  an  hour,  or 
an  hour  and  a  half  at  most,  a  great  part  of  the  amalgam  will  have  collected  at  the  bot- 
tom ;  and  in  consequence  of  the  dilution,  the  portion  of  horn  silver  held  in  solution 
by  the  sea  salt  will  fall  down  and  be  decomposed.  Into  the  small  plug  in  the  centre  of 
the  bung,  a  small  tube  with  a  stopcock  is  now  to  be  inserted,  to  discharge  the  amalgam 
into  its  appropriate  chamber.  The  cock  must  be  stopped  whenever  the  brown  muddy 
residuum  begins  to  flow.  The  main  bung  being  then  opened,  the  remaining  contents 
of  the  casks  are  emptied  into  the  wash-tun,  while  the  pieces  of  iron  are  kept  back. 
The  residuary  ore  is  found  to  be  stripped  of  its  silver  within  s  or  _I-  of  an  ounce  per 
cwt.  The  emptying  of  all  the  casks,  and  charging  them  again,  takes  2  hoars ;  and  the 
whole  process  is  finished  within  18  or  20  hours ;  namely,  1  hour  for  charging,  14  to  16 
nours  for  amalgamating,  I^  hour  for  diluting,  1  hour  for  emptying.  In  14  days,  3200 
cwts.  of  ore  are  amalgamated.  For  working  100  cwts.  of  ore,  14^  lbs.  of  iron,  and  2 
lbs.  121  ounces  of  mercury  are  required ;  whence,  for  every  pound  of  silver  obtained, 
0*95  of  an  ounce  of  mercury  are  consumed. 

Trials  have  been  made  to  conduct  the  amalgamation  process  in  iron  casks,  heated  to 
150°  or  160°  Fahrenheit,  over  a  fire ;  but,  though  the  de-silvering  was  more  complete, 
the  loss  by  mercury  was  so  much  greater  as  to  more  than  counterbalance  that  advantage. 

Treatment  ^  of  the  jlmalgam. — It  is  first  received  in  a  moist  canvass  bag,  through 
which  the  thin  uncombined  quicksilver  spontaneously  passes.  The  bag  is  then  tied  up 
and  subjected  to  pressure  Out  of  20  casks,  from  3  to  3i  cwts.  of  solid  amalgam  are  thus 
procured,  which  usually  consist  of  1  part  of  an  alloy,  containing  silver  of  12  or  13  loths 
(in  J 6),  and  6  parts  of  quicksilver.     The  foreign  metals  in  that  alloy  are,  copper,  lead. 


u 


628 


SILVER. 


Wv. 


i 


i 


gold,  antimony,  cobalt,  nickel,  bismuth,  zinc,  arsenic  nnil  ir«n      tv    cu      j      j  i   n 
contains  moreover  2  ti  3  loths  of  siJverIn  the  c^   '  "'     ^^®  ^^^'^  qnicMref 

1275     A  basis  ^;  b  is  an  open  basin  or  box  of 

'"*  fast  iron,  laid  in  the  wooden  drawer ;  y 

is  a  kind  of  iron  candelabra,  sapported 
upon  four  feet,  and  set  in  the  basin  £  s 
under  d  are  five  dishes,  or  plates  of 
wrought  iron,  with  a  hole  in  the  centre 
of  each,  whereby  they  are  fitted  upon 
the  stem  of  the  candelabra,  3  inches 
apart,  each  plate  being  successively 
smaller  than  the  one  below  it.  3  indi- 
cates a  cast-iron  bell,  furnished  with  a 
wrought-iron  frame  and  hook,  for  rais- 
L-  mg  it  by  means  of  a  pulley  and  cord. 
**  Th'  Tl;'*"^^^^-  ^^^  ^e"  has  been  set  in  its  place*  '"  *  ^^^^^^-iron  door  for  closing  the 

renewed'r^hrgh  a'^ipeln  ifZl  !!f  Z  w^""!  "^^^^'  T^^^''  "^"^*  ^^  -"^'"-"^ 
kept  always  submerseVand  cool.  The  d  awer  .  be.^n'"'  '"  '""T '\'  'T  ^"^^"  "^^^  ^ 
under  d  being  char-ed  with  \Zu  nf  »^oi         /'  •  J"^  properly  placed,  and  the  plates 

is  to  be  let  dolnTnto  thrwater  ^^  'a^  Tand  rT.,t^':^^''"fK' i°"'^*^^'  ^  ^^^^'^^  '^'  ^^"  3 

Upon  the  ledge  1,  which  defines  the  boUom  n/  th^r  'V  ^«^^^P«'!  ^^'^^  candelabra. 

laid,  having  a  ho  e  in  its  middle  fnrthphiT.     *^^  ^f^-P^ace,  a  circular  plate  of  iron  is 

fir-wood  ar'e  kindled  thl  the  dlrV'^^^^^  'V^'f  '^T^^'    ^P^"  ^his  plate  chips  of 

The  fuel  is  now  placed  i^tieva^an?^^^^^^^^^  T^  "^^^^  ^^  ^H^l  «"^  J"»^^  '^^^ht. 

must  be  fed  in  most  gradually  first  witrt„rf\h?nw-tK^  l^^^'  y*'^  f  ^^^  ^'"-     "^^^  ^« 

red,  the  mercury  volatilize  "and  ronii'-^^      v '^  charcoal ;  whenever  the  bell  gets 

At 'the  end  orS^hourshoSd  n^  ^  m  globules  into  the  bottom  of  the  basin  b. 

the  fire  is  stopped      When  "he  bell  has  b/onL'  '^  °?'^f  ^"T.^i^T^  '^  ^«»  ^"^^  t^**  ^ater, 

from  the  candelabra  d^^and  this  be^ '  taken  ouT  hi'  '/  ^'^'^  '^'  i^/  ""^^'''Z''  '^'""^"^ 

nace.    The  mercury    s  drained    dr^Pd    «n^  c   %  ^  '^•'^'^"  "  ''  '^'^  ^^^^  ^'"^^^  ^^^  fur- 

The  saver  is  fused  and  refinerbfc^pe^^^^^^^^    ''"'  "^^''^  '"'"  '^^  amalgamation  works. 

proma^Ty'outTlrt^^yfsiu  apparatus,  would  be  distilled  more 

815,  816:  ^  '"  ^^^  mercurial  retorts  described  and  figured  in  pages 

of  16 ;  one  fifth  paTof^h    mS  befng'c^^^^^^^^^^  ^-""'''f  |"^  ^"^^^  «"t 

Of  160  or  170  marcs,  in  black-lead  rrudEfifledwf.h-t    ^^'V  '^5"t^/°  quantities 
submitted  to  brisk  ignition     Th^  ^^i?  T  *"'"  ^^°  ^^^^^^^  <^^  ^heir  brims,  and 

liquid  slag,  whicrbelnrskimmed  off    ^"  ""'r  ''^•^^"'  f  °^"  ^«P^^«'  ^^^^  t^^-o^s  ^P  a 
Ader,  and  covered  wi?h  a  H^^  't  *°  ^^  '^'^^^^  over  with  charcoal 

the  charcoal  LXn  rrmoVed  aionlw^^  been  briskly  urged  for  a  short  time, 

observe  whether  the  vap^have  of aled     If  n ^  fil?  ^'  ""V  ^•^^^^'^^"^  ^^  order  to 

the  crucible  must  be  co?erKth^^^^^^^  ""'*  '^ '^^^^^  ^PP"^^' 

and  the  surface  of  the  silver  becomes  tranmiirS     Ik      n^  ^""^^P  ^°""^r  produced, 
gold  and  much  coppe;,  beTng  now  frirn  ^  if  Z^S   th  f  P\^?J?h  <^°"t->*"«  *  ""le 

maUon,\'S?4"u^^^^^^^  being  "submitted  to  a  second  amalg, 

with  three  or  four  per  cent    of  a  mktLl  Af  /  ''^T'    7^''  '^  ^''^  ^"^^^  a^^"? 

sulphate  of  soda),  aSd  then  refined  Thl  I  ^""^^t"'  ^?^'^  '^^*^^"^^  quicksalz  (impure 
tanks  in  which  the  contents  of  the  casks  are  niw!!^  ^T""'  '**?'  ^'  '^^^^'^  ^'"^  «^  ^^^ 
of  soda,  along  with  some  common  salt  sulnhitr  J"'''''^''  T'''''  '^''^^  of  sulphate 
Dhosphate,  a?seniate,  and  fluatTof  soda  Th!  ^l  'T"  ^"^  inanganese,  and  a  litUe 
«f  «  7n/A  «r    -1  .  ^  ^^^  ^^r^by  deposite  contains  from  i  to    » 

LVSi^einlZZ''^'-  '"'  ""  *"■««"-'  -'">«)  of  extracting  thi,  s.,.!  ,Va„u¥, 
•^*  '     ^"'  *^'°»  ana  iJ7y.      These  figures  exhibit  the  cupellatioi 


SILVER. 


629 


furnace  of  the  principal  smelting  works  in  the  Hartz,  where  the  following  parts  must  be 
distinguished}  ifig*  1278);  1.  masonry  of  the  foundation;  2.  flues  for  the  escape  of 
moisture  ;  3.  stone  covers  of  the  flues ;  4.  bed  of  hard  rammed  scoriae ;  5.  bricks  set  on 
edge,  to  form  the  permanent  area  of  the  furnace ;  6.  the  sole,  formed  of  wood  ashes, 
washed,  dried,  and  beaten  down ;  k,  dome  of  iron  plate,  moveable  by  a  crane,  and  sus- 
ceptible of  being  lined  two  inches  thick  with  loam;  w,  n,  tuyeres  for  two  bellows  •; 
having  valves  suspended  before  their  orifices  to  break  and  spread  the  blast ;  j,  door  for 
introducing  into  the  furnace  the  charge  of  lead,  equal  to  84  quintals  at  a  time;  s,Jig. 


1279 


1279,  two  bellows,  like  those  of  a  smith's  forge ;  y,  door  of  the  fireplace,  through  which 

billets  of  wood  are  thrown  on  the  grate;  x,  small  aperture  or  door,  for  giving  issue  to  the 

frothy  scum  of  the  cupellation,  and 
the  litharge;  z,  basin  of  safety, 
usually  covered  with  a  stone  slab,  ovei 
which  the  litharge  falls;  in  case  of 
accident  the  basin  is  laid  open  to  ad- 
mit the  rich  lead. 

The  following  is  the  mode  of  con- 
ducting the  cupellation.  Before  put- 
ting the  lead  into  the  furnace,  a  flooi 
is  made  in  it  of  ashes  beat  carefully 
down  (see  6,  Jig.  1278);  and  there  is 
left  in  the  centre  of  this  floor  a  circulai 

space,  somewhat  lower  than  the  rest  of  the  hearth,  where  the  silver  ought  to  gather  at 

the  end  of  the  operation.     The  cupel  is  fully  six  feet  in  diameter. 

In  forming  the  floor  of  a  cupel, 


35  cubic  feet  of  washed  wood 
ashes,  usually  got  from  the  soap 
works,  are  employed.  The  pre- 
paration of  the  floor  requires  two  and 
a  half  hours'  work ;  and  when  it  is 
completed,  and  the  moveable  dome  of 
iron  plate  has  been  lined  with 
loam,  84  quintals  (cwts.)  of  lead 
are  laid  on  the  floor,  42  quintals 
being  placed  in  the  part  of  the 
furnace  farthest  from  the  bellows, 
and  42  near  to  the  fire-bridge ;  to 
these,  scoriae  containing  lead  and 
silver  are  added,  in  order  to  lose 
nothing.  The  moveable  lid  is  now  luted  on  the  furnace,  and  heat  is  slowly  applied  in  the 
fireplace,  by  burning  fagots  of  fir-wood,  which  is  gradually  raised.  Section  1278  is  in  the 
line  c,  D,  of  1277. 

At  the  end  of  three  hours,  the  whole  lead  being  melted,  the  instant  is  watched  for 
when  n3  more  ebullition  can  be  perceived  on  the  surface  of  the  bath  or  melted  metal; 
then,  but  not  sooner,  the  bellows  are  set  a  playing  on  the  surface  at  the  rate  of  4  or  5 
strokes  per  minute,  to  favor  the  oxydizement. 

In  five  hours,  reckoned  from  the  commencement  of  the  process,  the  fire  is  smartly 
raised ;  when  a  grayish  froth  (abstrich)  is  made  to  issue  from  the  small  aperture  x  of 
the  furnace.  This  is  found  to  be  a  brittle  mixture  of  oxydized  metals  and  impurities. 
The  workman  now  glides  the  rake  over  the  surface  of  the  bath,  so  as  to  draw  the  froth 
out  of  the  furnace ;  and,  as  it  issues,  powdered  charcoal  is  strewed  upon  it,  at  the  aperture 
r,  to  cause  its  coagulation.    The  froth  skimming  lasts  for  about  an  hour  and  a  half. 


630 


SILVER. 


%§i 


After  this  time,  the  litharge  he eins  to  form  -«^  •»  •     i     t 
x;  its  issue  being  aided  by  a  hook     In  n^n'    ?    ''  '^  ''^^'J^^  ""^  ^r  ^^^  ^^'^^  openiDji 
pregnated  with  litharge,  the  woTktan  d.V^T/*-?"  "'  .!^%^°^'  «^  ^»»«  f«™«<^e  8^^  >«n 
litharge;  it  falls  in  from' of  the  smXapertSe^l^^  the  escape  of  thi  liouid 

By  means  of  the  two  moveable  vaJve^  l!,.«l'nH»  1  ^.^""^^^^j"  stalactitic  forms. 

should  be  made  to  cause  a  slight  curl  on  ihJ  Kn,  •  i  ^^  ^^^  '"«t«^-    The  wind 

lations,  and  gradually  propel  a  portion  of  the  b.h^'  '"^  ^'  to  produce  circular  undu- 
the  cupel,  and  allow  this  ?o  ret^rtsshlpeur^  ^^^^rds  the  edges  of 

of  air  should  drive  the  greater  part  of  the  lifh«rl.  .  I  ^u  ^P^^»tion.  The  stream 
the  workman  deepens  the  ouUeffor  k  in  nJononf  'T'n'  ?^'  ^:°^?"  ^P^"^"^  ^>  ^^ere 
scends,  and  the  bottom  of  theToor\\tt\^?^J^  ^^-  the  level  of  the  metal  bath  de- 

tharge'is  thus  obtained  during  about  2  honr^  nJ^'^^^'i'^ k  ""^  '^l  ^"^«^^^  ^"^'^^  ^^' 
gins  to  take  shape  in  the  cent^re  of  the  eupel    '  '"''  ^'"'^  '^'  '"^^  «^  "»^'^'  ^^ 

•lithaTcaVbe  "oked  for,  a^ wL^n  "trmTsST  •''\^  '°"'  .^^^^'^^'^^^  '^-'"^als  of 
cake  in  the  middle  of  the  floor  gTeatc^eZ/t  iJfV'  !^^  "^^^h^orhood  of  the  silver 
because  they  contain  silver   \C  thT  Sd^i^^^^^^^^^^  apart  the  latter  portions, 

places  before  the  little  opening  x  a  brick   inilt  ^  ''  ^creased,  and  the  workman 

The  use  of  this  brick  is      i    f«  k-  V     .7  ^    ^^"^  ^^  *  »""""^  to  the  efflux  of  lithar-e 
for  example,  shouWan^;;t  on  t^a^^^^^^  f  '^'  ^"^„"  '"  ''''  '^  «"y  aS-n^  i 

litharge,  should  that  still  cSatin^ro,n/t^  ^'^  ^"'"^''  \^'  **^  '"'''"^^  «  'magazine  of 
cupel,  for  in  this  dilemma  reS/eT^^^^^^^  rakpH  TX^'  'f"^'-"!^'  '^^^^^^^^  ^^  the 
the  escape  of  the  water  that  Lst  b^^thm^n  .    .if^M  ^^""^  *"."  *^*^  "^'^^^J  3.  to  prevent 

When^he  argentif^^ouf  lirarge  ^^^^^^^  '^'T'^  ^^^^e  procnfs. 

moved,  it  is  let  out  in  the  form  of  a  jet  bv  the  Lit Prn^  'V^l  "?°-«^i"^'  is  to  be  re- 

Lastly,  after  20  hours  the  Rllvpr  S     •        dexterous  use  of  the  iron  hook. 

The  moment  for  stoppYng  the  fi  randlhe'beTnw '  •  '•'  J^'l  ^7^^l""^  "^^^^^  <^'^^"^". 
ance  of  the  colored  particles  of  or  vdenflLHTi!'  .'"^i.'^^l^^  »>y  the  sudden  disappear- 
undulate  with  extrerrapidi?y  o7er  ife  sll^htTv  1' '"  '^'  T''  T'''''''  ^^  «^>'^^'ion, 
ing  from  the  centre  to  the  circumference  fhJrlZ  ""  surface  of  the  silver  bath,  mov- 
is  called  the  lightning,  or  fiStTon      Wh^n^r^^^^^  ""^  ^v^"  ^^''^^  'Jisappearance 

perfectly  clean,  there  is  introducedTnto  th^  furnlce  ^'.^7'''  *^"  ^^^'^  "^  ^^^^^^'^  ^^'^^ 

"TtrpXirn7ft'-i%^'f^^^^^^^ 

woTkTng    'Tie  pr^^^^^^  Z'^'^f'^'T  ^^!?  ^^^^^  ^"  ^— ^  ^^  or  20  hours' 

leads  employed,  SndSn  the  acre's  oHe'Ltr^'  Z  '""t  ^^^T^  ^^  Parity  of  tlTc 
of  fuel.    A'go'od  workman  co^Te  es  the  cu'npnI?L'''r\f '"?  ^'f  "^^  *^^  ^^^^^'^T 

at.e.t^e^ofS4.uintalcha;g-oS^^^^^ 
The  products  of  the  charge  are  as  follows  :~ 

2  Pnlfi,t>,     ^"^  '"  ^^9  ?""^'»  "^  '"^^^^  «"d  3  loths  of  alloy  - 

2.  Pure  litharge,  containing  from  88  to  90  per  cent,  of  lead    - 

3.  Impure  litharge,  holding  a  little  silver  . 

4.  Skimmings  of  the  cupellation  .  .  '        " 

5.  Floor  of  the  furnace  impregnated  with  litharge  '.        I 

aboK  quintal  amiaim  116  Colopu:  poundl  ^       i03  pound,  ttvoirdupous  and  ilu 

From  numerous   experiments  inihe  i»rpnt\r«t   •.  ». '    v        /^^  ^"  *  ^°^«"" -"^ale. 
100  quintals  of  lead  can   be  profitlblv  culTJ^^^^^    "'  ^''"  ^^^"'^  *^^^  "«'  "^«^^  than 
furnace,  and  however  pLerfufandmultS  '^'T/'"^'  ^"^^^'^''  '«^^^  ^^^ 

loss  on  eilher  the  lead  or  the  silver  or  on   both  t      i T  ^""^  *"^'^',''  "^^^  ^^5  for  the 
no  less   than  500  quintals  were  acted  on   in  ^  ^r^li^lsrr''^^'     \"  «"«  "^^'"Pt, 

W«ono/  M.Z..4^^5iis  r:^a-i-la-eaTJ^;;r^^^^^^^^^ 
Such  is  the  train  of  operations  by  which  the  cupriferous  galena  schlich,  or  ground  oit 


24  to  30  marcs. 

50  -  60  quintals. 
2-6      — 
4-8      — 

22-30      — 


SILVER. 


631 


is  reduced,  in  the  district  of  Clausthal,  into  lead,  copper,  and  silver.    The  workt  of 
Fmnkenscharn  have  a  front  fully  400  feet  long. 

Ftg.  1279,  exhibits  the  plan  and  elevation  of  these  sraelting-works,  near  Clausthal,  is 
the  Hartz,  for  lead  ores  containing  copper  and  silver,  where  about  84,000  cwts.  oftdUick 


Silver-smelting  Works  of  Frankenacham^  near  Clausthal. 


128C 


(each  of  123  Cologne  pounds)  are  treated  every  year.  This  quantity  is  the  prodir*  of 
thirty  distinct  mines,  as  also  of  nearly  as  many  stamp  and  preparation  works.  All  these 
different  schlichs,  which  belong  to  so  many  different  joint-stock  companies,  are  confound- 
ed and  worked  up  together  in  the  same  series  of  metallurgic  operations;  the  resulting 
mixture  being  considered  as  one  and  the  same  ore  belonging  to  a  single  undertaking;  but 
in  virtue  of  the  order  which  prevails  in  this  royal  establishment,  the  rights  of  eacn  of  the 
companies,  and  consequently  of  each  shareholder,  are  equitably  regulated.  A  vigorous 
control  is  exercised  between  the  mines  and  the  stamps,  as  also  between  the  stamps  and 
the  smelting-houses ;  while  the  cost  of  the  metallurgic  operations  is  placed  under  the  ofli- 
cers  of  the  crown,  and  distributed,  upon  just  principles,  among  the  several  mines,  ac- 
cording to  the  quantities  of  metal  furnished  by  each. 

From  these  arrangements,  the  following  important  advantages  flow : — 
1.  The  poor  ores  may  be  smelted  with  profit,  without  putting  the  companies  to  any 
risk  or  expense  in  the  erection  of  new  works ;  2,  by  the  mixture  of  many  different  ores, 
the  smelting  and  metallic  product  become  more  easy  and  abundant;  3,  the  train  of  the 
operations  is  conducted  with  all  the  lights  and  resources  of  science  ;  and  4,  the  amount 
of  metal  brought  into  the  market  is  not  subject  to  such  fluctuations  as  might  prove  inju- 
rious to  their  sale. 
The  following  is  the  series  of  operations; — 

1.  The  fusion  of  the  schlich  (sludge) ;  2,  the  roasting  of  the  mattes  under  a  shed,  and 
their  treatment  by  four  successive  re-meltings ;  3,  the  treatment  of  the  resulting  black 
copper;  4,  the  liquation  ;  5,  the  re-liquation  iressjias;e)  ;  6,  the  refining  of  the  copper  ; 
7,  the  cupellation  of  the  silver;  8,  the  reduction  of  the  litharge  into  lead.  The  5th  and 
6th  processes  are  carried  on  at  the  smelting  works  of  Altenau. 

The  buildings  are  shown  at  a,  b,  c,  and  the  impelling  stream  of  water  at  d  ;  the  upper 
figure  being  the  elevation  ;  the  lower,  the  plan  of  the  works. 

a,  is  the  melting  furnace,  with  a  cylinder  bellows  behind  it ;  6,  c,  d,  furnaces  similar 
to  the  preceding,  with  wooden  bellows,  such  as  yig.  1281 ;  «,  is  a  furnace  for  the  same 

purpose,  with  three  tuyeres,  and 
a  cylinder  bellows ;  /,  the  large 
furnace  of  fusion,  also  with  three 
tuyeres;  g,  a  furnace  with  seven 
tuyeres,  now  seldom  used ;  A,  low 
furnaces,  like  the  English  slag- 
hearths,  {krummofen,)  employed 
for  working  the  last  mattes ;  fc, 
slag-hearths  for  reducing  the  li- 
tharge ;  m,  the  area  of  the  liqua^ 
tion  ;  n,  p,  cupellation  furnaces. 

Xy  y,  a  floor  which  separates 
the  principal  smelting-house  into 


632 


SILVER. 


two  stories;  the  materials  acstined  for  charpinir  «i,.  r„  *  .       , 

Copper,  (finally  purified  in  the  works  of  Alten.n,)    "      .     "  ^ 


Total  product. 


-    28,564 


e^ab,rhfe'nt~ht';ar"t  SVu^n  sh"'""  ••"^'"  ""^"^^  ''^'^  '-  ">«  «™«  ofh. 
bellows  are  constru'ctXToSy  of  w3t'iZm/''T',!'  """""  ""'  «f  ■'^'h"'^''-  Th« 
a  bishop  of  Bamberg,  a  Ju,  ihl  yerr^'O      Aflnr  ^^'-''''''''ir  i-nprovemen,  n.ade  b, 

were  adopted,  towards  i730,  fn^Ymos  a^t^he  iLeltTne  wS,  l!",?"'  "'""fi""-^.  "4 
a  few  places,  as  Carniola   wherp  Inrai  ^1       smelling- woi  ks  ol  ihe  co*  jnent,  except  in 

to  he  erected.  Thes^p  C'^/a  XpeTreCs"'e"^\r 'r?!-^  water  blowinVmac'hi^: 
have,  however,  many  imperfections  •  theiV  size  m?,T'X  u  "^^^*^«^'«  wooden  boxes, 
order  to  furnish  an  adequate  stream  nfifr    fi       T        ^^"  ^^  inconveniently  larj?e,  in 

-^^^^    l9fiQ    u __^.™.^_ the  seal,  (^ite.)    In  the  bottom  of 

the  p/e,  there  is  an  orifice  furnish- 
ed with  a  clack-valve  rf,  opening 
inwards  when  the/y  is  raised,  and 
shutting  when  it  falls.  In  order 
that  the  air  included  in  the  capaci- 
ty of  the  two  chests  may  have  no 
other  outlet  than  the  nose-pipe  w. 
the  upper  portion  of  the  gi/e  is  pro- 
vided at  its  four  sides  with  small 

square  slips  ofwood,c,c,c,  which 
^_ ^    are  pressed  against  the  sides  of  the 

b,byb,  while  they  are  retained  upon  the  eife  hv  mp.nc    r  ^  ^V°"^  springs  of  iron  wire, 

a,  a,  a.     The  latter  a,  a,  are  SratS  i„  thp  .     .      '""^^  T^'^  ^'^'^^  "^'wood,  a. 

Stems,  called  bucheaes /they  are'atthed,  aUhefr  [owe^^  ^o'^h'^^'  "?^?  rectanguW 

r/6  G.     P,  IS  the  driving-shaA  of  a  water'wheel  wMHi  hv  1 '      ^^J?  "^""^'^  ^^^^^  «^  the 

lurZes^e'i^'pioy^^^^^^ 

lead  ores  extracted  from  the  mine  of  RammelsberT'    See  .^"^^    "i''  ^"'-^"^^^^'"^  ^^^  silvery 

Pig.  1283,  is  the  front  elevation  of  theTw in  fuT;aces    bun»  •  ""^  *"  P-.^^^,  Vol.  1L 
n,.  1284,  IS  a  plan  taken  at  the  level  of  T^^i^t^  ^^/^  't  of  .Tml* 

^2®^  ^f*.  1285  aid  1286,  exhi! 

bit  two  vertical  sections? 
the  former  in  the  line  a,  b, 
the  latter  in  the  line  c,  d, 
of  fig,  1284.   In  these  four 
figures   the  following  oh. 
jects  may  be  distinguished, 
a,  by  c,  dy  a  balcony  or 
platform   which   leads  to 
the  place  of  charging,  n  ; 
«,/; wooden  stairs,  by  which 
the     charging    workmen 
mount  from  the  ground  ;>,^, 
of  the  works,  to  the  plat- 
form ;  gy  hy  brick-work  o| 
the    furnaces;    t,  /c,  wall 
-,f.^ .    ■■    ■    -J    ^     the     smelting- worki^ 

OTpported  J  ly  upper  basin  of  reception,  hollowed  out  of  th^  h.?^***"^!    "^^'""^  /^^>'   "« 
bed,)  6;  m,  arch  of  the  tuydre  v.  by  which  mcK  f  ^  brasqru,  (ci  rround  charcoal 

»u,cic  V,  oy  wmcli  each  furnace  receives  the  blast  of  two 


SILVER. 


633 


bellows;  n,  place  of  charging,  which  takes  place  through  the  upper  orifice  n,  o,  of  the 
basjn  w,  o,  v,  t,  of  the  furnace;  /,  a  slab  of  clay,  placed  in  such  a  way  that,  during  the 
^  1284  treatment  of  the  lead,  a  liitle 

metallic  zinc  may  run  together 
in  a  sloping  gutter,  seen  m 
fig.  1269,  formed  of  slates  ce- 
mented together  with  clay. 

In^gs.  1283  and  1285,  1,2-, 
is  the  brick-work  of  the  fcon- 
dations;  »n,  conduits  (called 
evaporatory)for  the  exhalation 
of  the  moisture ;  4,  a  layer  of 
slags,  rammed  above ;  5,  a  bed 
of  clay,   rammed    above    the 

.  .    ^   ,    ~       J  *  .  ^'^"^ '  ^>  ^  brasque,  composed 

•)!  one  part  of  clay,  and  two  parts  of  ground  charcoal,  which  forms  the  sole  of  the  furnace. 
The  excellent  refinery  furnace,  or  treibheerd,  of  Kre.leiickshutte,  near  Tarnowitz,  in 

Upper  Silesia,  is  represented  in  fig?  1287 
and  1288.     a,  is  the  bottom,  made  ol  slag 
or  cinders ;  b,  the  foundation  of  fire-bricks ; 
f,  the  body  of  the  hearth  prcner,  composed 
of  a  mixture  of  7  parts  of  doiomite,  and  1 
of  fire-clay,  in  bulk;  d,  the  grate  of  the  air 
furnace;  e,  the  fire-bridge;  /,  the  dome  or 
cap,  made  of  iron  plate  strengthened  with 
bars,  and  lined  with  clay-lute,  to  protect 
the  metal  from  burning ;  g,  the  door  of  the 
fireplace;  h,  the  ash-pit;  i,  the  tap-hole; 
ky  ky  the  flue,  which  is  divided  by  partition! 
into  several  channels ;  Z,  the  chimney ;  m, 
a  damper-plate  for  regulating  the  draught ; 
n,  a  back  valve,  for  admitting  air  to  cool 
the  furnace,  and  brushes  to  sweep  the  flues; 
o,  tuyere  of  copper,  which  by  means  of  an 
iron  wedge  may  be  sloped  more  or  less  to- 
wards the  hearth;  />,  ihe schneppety  a  round 
1286  piece  of  sheet  iron,  hung  before  the  eye  of  the 

tuyere,  to  break  and  spread  the  blast;  9,  the 
outlet  for  the  glassy  litharge. 

Lime-marl  has  been  found  to  answer  well  foi 
making  the  body  of  the  hearth-sole,  as  it  ab- 
sorbs the  vitrified  litharge  freely,  without  com- 
bining with  it.  A  basin-shaped  hollow  is  form- 
ed in  the  centre,  for  receiving  the  silver  at  the 
end  of  the  process  ;  and  a  gutter  is  made  across 
the  hearth  for  running  off  the  glatte  or  fluid 
litharge. 

ir"^TooP®^'  ^^^^'  represent   the   eliquation  hearth  of  Neustadt. 

/•    -.J-  *^'*  *^''°^^  ^^*^^^°"  5  fiS'  1290  is  a  front  view;  and^g.  1 291. 

a  longitudinal  section.     It  is  formed  by  two  walls  «,  a,  ^  feet  hi-h 


placed  from  I  to  1  foot  apart,  sloped  off  at  top  with  iron  plates,  three 


inches  thick,  and 
18  inches  broad, 
called  saigers-char" 
teUy  or  refining 
plates,  by  by  inclin- 
ed three  inches  to- 
wards each  other 
in  the  middle,  so  as 
to  leave  at  the  low- 
est point  a  slit  two 
and  a  half  inches 
wide  between  them, 
through  which  the 
leed,  as  it  sweats 
out  by  the  heat,  is 
allowed  to  fell  into 


*"""■■""■"■"■" 


634 


SILVER. 


the  space  between  the  two  walls  c,  called  the  jt/»»v#^«.«..-  , 

a  crucible  or  poi.     Up- 
on one  of  the  long  sides, 
and  each  of  the  shorter 
ones,  of  the  heartli,  the 
walls  rf,  d,   are  raised 
two  feet  high,  and  up- 
on these   the  liquation 
lumps   rest;    upon   the 
other  long  side,  where 
there  is  no  wall,  there 
is   an   opening  for  ad- 
mitting these  jumps  in- 
lo    the    hearth.      The 
openings  are  then  shut 
with   a    sheet    or   cast 
iron  plate  «,  which,  by 
_  means  of  a  chain,  pul- 

may  be  easily  raised  and  lowered      r  J=  «  «»  r     •  .      ^^^'  *"^  counterweight, 

. \  ""*  r^r   .  oo/'   ^  ?  passage  for  increasing  the  draught  of  air. 

rickshut  e  by  Tarnowilz;  a,  is  the  fire  door;  6,  the  grate-  r  The 
door  for  introducing  the  silver;  d,  the  inoveable\est,festing  ipon 

but  thki  AnJ  -^  ^'\  ^""^^^  ^^^"  ^^"'^  ^^^»"  to  be  necessary ; 
bu   this  IS  done  in  order  to  be  able  to  place  the  surface  of  the 

if  A/^l   M*  ^'^rT^y^  ^^  ^"^'  ^'^^'     For  Ihi'refinins  of  JOO  marks 

cubic  feet  of  pit-coal  are  rlqS   '  The  11"'"'^'  ^', '"'  ^°i^^  (half  ounces)  per  cw^S 

silver  and  soft  lead  are  pinntoii  '"'  '"^'^  "'"'^  '^^  ^"^^^'^  ^^^°^^  ^^"^  ^'"P"^ 

At  these  smelting-houses,  from  150  to  160  cwts.  of  very  pure  v^UW  lead  (lead  con- 

^_I290        ^  J291 


SILVER. 


63S 


.Uoy  containing  f„n.  uj  lo-'lsT.Tr ff  iLtXr  ""efcm.'Js  S„T  ""''  ""'"  '" 


1292 


1293 


fireplace  is  22  inches  squarerrnd  s  «™ratS  Z„  r"''/.«'-  ^P*  ""^  !-«».  ^"h"* 
in  breadth.  The  flame,  after  having  S3  o^er  .h^  ""r  '"'*  X»  fi"-Wdge,  14  inche. 
ters  two  flues  e,  e,  on  the  onTO^he  s?de  o^lh.  f^^  ^"'i^'v  '"^"'*  '«»''  '"">«  «"Pel,  en- 
f, .-,  40  feet  high.     At  the  bK  nf  ,h!  lill  "=^'  "^""'  '«™i"»'e  '"  a  chimney  t  L 

Ulfic  dust  de^sited  withiSr'%"hefe  „pen'r47re"irduri^^{i,'''  *■"'  """"'»"'  '"^  "»^ 

The  cupel  or  test,  which  constitulL,    n'  fact*  fhe  ™"e  oY  Jh7  ll"?.;  •        ... 
operatton  take,  place,  is  moveable.     I,  consi:^",  "S  Tver  Li' d  1;^  rinf^f'^ 


n  *u««jca*  .fc  .    TOUT  iron  oars  (a,  d,  m,  m,  b,  c,  n,  n)  are  fixed  across  iti 

1294  u-^  „„H  ,m,i  .  bottom,      which      are 

also  3|  inches  broad, 
and  an  inch  thick. 
The  first  of  these  bars 
is  placed  9  inches 
from  the  end  of  the 
elliptic  ring  nearest 
the  fireplace,  and 
the  three  others  ai2 
equally  distributed  be- 
tween this  bar  and  the 
back  end. 

In  forming  the 
cupel,  several  layers 
of  a  mixture  of  moist- 
ened bone  ashes,  and 
fern  ashes,  in  very 
fine  powder,  are  put 
into  the  test-frame. 
The  bone  ash  con- 
stitutes from  I  to  1 
of  the  bulk  of  the 
mixture,  according 
r  I-  ,,..,,  to  the    purity  of   the 

rem  ashes  employed,  estimated  by  the  proportion  of  potash  they  contain,  which  has  the 
property  of  semi-vitrifying  the  powder  of  burnt  bones,  of  thus  removing  its  friability,  and 
1296    „      _!*      .m_        „  joqY 

C ^_ 


Vi. 


renderms  It  more  durable.  The  layers  of  ashes  are  strongly  beat  down,  till  the  frame  is 
entirely  filled.  The  mass  thus  formed  is  then  hollowed  out  by  means  of  a  little  snade 
made  on  purpose,  till  it  is  only  three  quarters  of  an  inch  thick  above  the  iron  bars  near 
the  centre  of  the  bottom.  A  flange,  2  inches  broad,  is  made  at  the  upper  part,  and  2i 
inches  at  the  lower  part,  except  on  the  front  or  breast,  which  is  5  inches  thick  In  thb 
anterior  part,  there  is  hollowed  out  an  opening  of  an  inch  and  a  quarter  bro'ad,  and  6 
inches  long,  with  which  the  outlet  or  gateway  of  the  litharge  communicates 

The  cupel  thus  prepared  is  placed  in  the  refining  furnace\  It  rests  in  an  iron  ring  buUt 
into  the  brickwork.  The  arched  roof  of  the  furnace  is  12  inches  above  the  cupel  n?ar"he 
fire-bridge,  and  9  inches  near  the  flue  at  the  other  end 

is  JlL^rdlroV^K  '"  '*""  ^''^  "^  '^'  ^''™^'''  °^P"'^'"  '^  '^'  '^'  *'  ^^'^^^  '^'  ^'^^S^ 

dud^gldted  kid""  ^'^  *'  '^'  '^''  ""^  '^"^  '"P'^'  '^'^''  ^''  ^"""^'^^  ««"  ^'  ^^'  ^""^ 
Refining  of  lead  to  extract  its  silver.--This  operation,  which  the  leadof  Derbvshirecan- 
not  be  submitted  to  with  advantage,  is  performed  in  a  certain  number  of  the  smelting- 
houses  at  Alston-moor,  and  always  upon  leads  reduced  in  the  Scotch  furnace 

The  cupel  furnace  above  described  must  be  slowly  heated,  in  order  to  drv  the  cunel 

'^tHe'JZi:iVL%''"^xk'^^^\'^''''i:^  infallibly  be  produced  by  sudden  7vaporati^ 
of  the  moisture  m  it.  ^  Whenjt  has  been  thus  slowly  brought  to  the  verge  of  a  red 
heat.  It  IS  almost  completely  filled  with  lead  previously  melted  in  an  iron  pot.  The 
cupel  may  be  charged  with  about  5  cwts.  At  the  temperature  at  whicn  the  lead  is  in- 
troduced.  It  IS  immediately  covered  with  a  gray  pellicle  of  oxyde;  but  when  the  heat  of 
the  furnace  has  been  progressively  raised  to  the  proper  pitch, -t  becomes  whitish-rcU, 
and  has  its  surface  covered  over  with  litharge.  Now  is  the  time  to  set  in  action  the 
blowing-machine,  the  blast  ot  which,  impelled  in  the  direction  oi  u.e  crcat  axis  ol  th* 
cupel,  drives  the  litharge  towards  the  breast  of  the  cupel,  and  makes  it  flow  out  by  the 

7t 


li 


636 


SILVER. 


?2.^r  ??^  ^'  '^'  l^^^J^  7^'^^  'i  ^^"'  ''^''  ""  *^^^*-»^«"  P'«te,  on  a  level  with  th« 

floor  of  the  apartment,  and  is  dispersed  into  tears.    It  is  carried  in  this  state  to  the  fur- 

nace  of  reduction  and  revived.     As  by  the  effect  of  the  continual  oxydization  which  it 

anderg^oes,  the  surface  of  the  metal  necessarily  falls  below  the  level  ofThegat^iy  of 

the  litharge,  melted  lead  must  be  added  anew  by  ladling  it  into  the  furnacffSL  ^he 

iron  boiler,  as  occasion  may  require.    The  operation  is  carried  on  in  this  manner  till 

84  cwts  or  4  Newcastle /od^ier,  of  lead  have  been  introduced,  which  S.es  from  16  to    8 

hours,  if  the  tuyere  has  been  properly  set.    The  whole  quantity  of^ilver  wh  ch  th^ 

mass  of  lead  contams,  s  left  in  combination  with  about  1  cwt.  of  Lad,  which  uider  the 

name  of  nch  lead,  is  taken  out  of  the  cupel.  *  '  * 

When  a  sufficient  number  of  these  pieces  of  rich  lead  have  been  procured,  so  that  br 

2M0  on n^Z"     r  T^^'^l^^'  determined  by  assaying,  they  contain  in  whole  from  1000  to 

2000  ounces  of  silver,  they  are  re-melted  to  extract  their  silver,  in  the  same  furnace  but 

ma  cupel  which  differs  from  the  former  in  having  at  its  bottoi  a  depression  capable  of 

receiving  at  the  end  of  the  process  the  cake  of  silver.     In  this  case  a  portion  of  Te  hot- 

th"ed1I^s'onre*'snver  ''''  ^  ^^^  '*'''"*  ""^^  ^^  ^"'^"^  ^'''^^  "^'^^  *  ""^^  rake,  from 
The  experiments  of  MM.  Lucas  and  Gay  Lussac  have  proved  that  fine  silver,  exoosed 
to  the  air  in  a  state  of  fusion,  absorbs  oxygen  gas,  and  gives  it  out  again  in  the  act^ 
consolidation  The  quantity  of  oxygen  thus  absorbed  may  amount  to%wen?y.two  tiLei 
the  volume  of  the  silver.  The  following  phenomena  are  observed  when  the  mass  of  mTtS 
IS  considerable ;  for  example,  from  40  to  50  pounds. 

The  solidification  commences  at  the  edges,  and  advances  towards  the  centre  The 
liquid  silver,  at  the  moment  of  its  passage  to  the  solid  state,  experiences  a  slight  agination 
and  then  becomes  motionless.  The  surface,  after  remaining  thus  tranquil  for  a  mtle' 
flow  fn  H-f?"'"  ,T^"1^''^  perturbed,  fissures  appear  in  one  or  several  lines,  from  wh  ch 
^Jnn  ^J.f '•f  ^^7^-^'°^ >  st'-eams  of  very  fluid  silver,  which  increase  the  original  ad- 
tation  The  firs  stage  does  not  yet  clearly  manifest  the  presence  of  gas,  and  seems  to 
arise  from  some  intestine  motion  of  the  particles  in  their  tendency  to  groip,  on  entmn? 
upon  the  process  of  crystaUization,  and  thus  causing  the  rupture  of  the  Invelop  or  ex  S 
crust,  and  the  ejection  of  some  liquid  portions.  ^      exiernai 

.r.t^^''  remaining  some  time  tranquil,  the  metal  presents  a  fresh  appearance,  precisely 
^;?l!f  ?  to  volcanic  phenomena.     As  the  crystallization  continues  the  oxy^n  gas  J 

fnTeTr  nfThl^c/'?^"'''"  ^'  ^  • '  ""'  °^°.'"  C^^"^^^'  ^"''^^'^S   ^'^'^  ^'  '^^^^^  silver  from    he 
interior  of  the  surface,  producing  a  series  of  cones,  generally  surmounted  by  a  small  crater 

vomiting  out  streams  of  the  metal,  which  may  be  seen  boiling  violently  within  them  ' 
«n J  tw  ^Jh-^l  g'-a'l^ally  increase  in  height  by  the  accumulation  of  metal  throwi  up. 
and  that  which  becomes  consolidated  on  their  sloping  sides.  The  thin  crust  of  metS 
on  which  they  rest,  consequently  experiences  violent  impulses,  being  alternately  raised 
and  depressed  by  such  violent  agitation,  that  were  it  not  for  the  tenacity  and  elasTicity 
fjA^'^^'^h  here  would  evidently  arise  dislocation,  fissures,  and  other  anaToious 
accidents.  At  length  several  of  the  craters  permanently  close,  while  others  cont!nu'e  to 
allow  the  gas  a  passage.  The  more  difficult  this  is,  the  more  the  craters  become 
elevated,  and  the  more  their  funnels  contract  by  the  adhesion  or  coa^u  at  on  of  a 

fZ\Z  °^w'  °''''^:  J^'  P^'^J^^^^'^"  «*'  ^^°*»"'^^  °^  «"^«^  "o^  »>ecomes  more  violent* 
i  Ir^l^'r  1  ' -'"^^  ^"^  ^'^^l  distances,  even  beyond  the  furnace,  and  accompanied  by 
a  series  of  explosions,  repeated  at  short  intervals.  It  is  t^enerally  the  last  of  these  little 
J^l'tZZ  '^'  '^"ains  the  greatest  altitude,  and  exhibits  the  foregoing  phenomena  w"h 
the  greatest  energy.     Jt  is,  moreover,  observable,  that  these  cones  do  Jot  all  arise  at  the 

nZl  ™^'''™'  ^n^  T^^^^^f'  ^°'''^"'  ^^^'^  others  commence  forming  at  other 
ppmts      Some  reach  the  height  of  an  inch,  forming  bases  of  two  or  three  inches  in 

of'aTlToir.  '  """''''"^  ^^  '^''  "^^•^^'^'"'^  ^^  "'  ^'^''  ^'•^"^  ^^^^  »«  three  quJte« 

.K^y'lf  *hf /;j™ation  of  these  cones,  by  the  evolution  of  gas,  portions  of  silver  are 
shot  forth,  which  assume,  on  induration,  a  form  somewhat  cylindrical,  and  often  ve^ 
fantastic  notwithstanding  the  incompatibility  which  appears  to  ex trbetween  th^ 
fluidity  of  the  silver  and  these  elongated  figures.  Their  appearance  is  momenlarv  and 
w.lho.rt  any  symptoms  of  gas,  although  it  is  impossible  to  decide  whetheT  they  mly  no' 

Jrar^'peiiod."'""'''  '''^'  ^*^^"'  "  ^'^^'  ''  ^-^^^'""^  ^^«^  P^^»°°^--  of  theTj 

Till  very  recently,  the  only  operations  employed  for  separating  silver  from  lead  in  the 
English  smelting-works,  were  the  following  •—  o     *  ^^  »»""i  icau  m  loie 

llJ;.?Tr^^*'";i'"  '^r'''^  ^^l  leadvr^s  converted  into  a  vitreous  oxyde,  which  w 
Ooated  oH  from  the  surface  of  the  silver. 

2.  Reduction  of  that  oxyde,  commonly  called  lithart'e 

J 


SILVER. 


637 


Cupellation  and  its  two  complementary  operations  were,  in  many  respects,  objectiona* 
blc  processes  j  from  the  injurious  effects  of  the  lead  vapors  upon  the  health  of  the  work, 
men ;  from  the  very  considerable  loss  of  metallic  lead,  amounting  to  7  per  cent,  at  least ; 
and,  lastly,  from  the  immense  consumption  of  fuel,  as  well  as  from  tne  vast  amount  of 
manual  labor  incurred  in  such  complicated  operations.  Hence,  unless  the  lead  were 
tolerably  rich  in  silver,  it  would  not  bear  the  expense  of  cupellation. 

The  patent  process  lately  introduced  by  Mr.  Paltinson,  of  Newcastle,  is  not  at  all  pre- 
judicial to  the  health  of  workmen;  it  does  not  occasion  more  than  2  per  cent,  of  loss  ot 
lead,  and  in  other  respects  it  is  so  economical,  that  it  is  now  profitably  applied  in  Nor- 
thumberland to  alloys  too  poor  in  silver  to  be  treated  by  cupellation.  This  process  if 
founded  upon  the  following  phenomena. 

After  melting  completely  an  alloy  of  lead  and  silver,  if  we  allow  it  to  cool  very  slowly, 
continually  stirring  it  meanwhile  with  a  rake,  we  shall  observe  at  a  certain  period  a 
continually  increasing  number  of  imperfect  little  crj-stals,  which  may  be  taken  out  with  a 
drainer,  exactly  as  we  may  remove  the  crystals  of  sea  salt  deposited  during  the  concen- 
tration of  brine,  or  those  of  sulphate  of  soda,  as  its  agitated  solution  cools.  On  submit- 
ting to  analysis  the  metallic  crystals  thus  separated,  and  also  the  liquid  metal  deprived  ol 
them,  we  find  the  former  to  be  lead  almost  alone,  but  the  latter  to  be  rich  in  silver,  when 
compared  with  the  original  alloy.  The  more  of  the  crystalline  particles  are  drained  from 
the  metallic  bath,  the  richer  does  the  mother  liquid  become  in  silver.  In  practice,  the 
poor  lead  is  raised  by  this  means  to  the  standard  of  the  ordinary  lead  of  the  litharge 
works ;  and  the  better  lead  is  made  ten  times  richer.  This  very  valuable  alloy  is  then 
submitted  to  cupellation ;  but  as  it  contains  only  a  tenth  part  of  the  quantity  of  lead  sub- 
jected to  crystallization,  the  loss  in  the  cupel  will  be  obviously  reduced  to  one  tenth  of 
what  it  was  by  the  former  process;  that  is,  seven  tenths  of  a  per  cent.,  instead  of  seven. 
These  nine  tenths  of  the  lead  separated  by  the  drainer,  are  immediately  sent  into  the 
market,  without  other  loss  than  the  trifling  one,  of  about  one  half  per  cent.,  involved  in 
reviving  a  little  dross  skimmed  off  the  surface  of  the  melted  metal  at  the  beginning  of  .he 
operation.  Hence  the  total  waste  of  lead  in  this  method  does  not  exceed  two  per  cent. 
And  as  only  a  small  quantity  of  lead  requires  to  be  cupelled,  this  may  be  done  with  the 
utmost  slowness  and  circumspection ;  where'by  loss  of  the  precious  metal,  and  injury  to 
the  health  of  the  work-people,  are  equally  avoided. 

The  crystallization  refinery  of  Mr.  Pattinson  is  an  extremely  simple  smelting-house. 
It  contains  3  hemispherical  cast-iron  pans,  41  inches  in  diameter,  and  |  of  an  inch  thick. 
The  3  pans  are  built  in  one  straight  line,  the  broad  flange  at  their  edge  being  supported 
upon  brick-work.  Each  pan  has  a  discharge  pipe,  proceeding  laterally  from  one  side  of 
its  bottom,  by  which  the  melted  metal  may  be  run  out  when  a  plug  is  withdrawn,  and 
each  is  heated  by  a  small  separate  fire. 

Three  tons  of  the  argentiferous  lead  constitute  one  charge  of  each  pan;  and  as  soon 
as  it  is  melted,  the  fire  is  withdrawn  ;  the  flue,  grate-door,  and  ash-pit,  are  immediately 
closed,  and  made  air-tight  with  bricks  and  clay-lute.  The  agitation  is  now  commenced, 
with  a  round  bar  of  iron,  terminated  with  a  chisel-point,  the  workman  being  instructed 
merely  to  keep  moving  that  simple  rake  constantly  in  the  pan,  but  more  especially 
towards  the  edges,  where  the  solidification  is  apt  to  begin.  He  must  be  careful  to  take 
out  the  crystals,  progressively  as  they  appear,  with  an  iron  drainer,  heated  a  little  higher 
than  the  temperature  of  the  metal  bath.  The  liquid  metal  lifted  in  the  drainer,  flows 
readily  back  through  its  perforations,  and  may  be  at  any  rate  effectually  detached  by  giv- 
ing the  ladle  two  or  three  jogs.  The  solid  portion  remains  in  the  form  of  a  spongy,  semi- 
crystalline,  semi-pasty  mass. 

The  proportion  of  crystals  separated  at  each  melting,  depends  upon  the  original  quality 
of  the  alloy.  If  it  be  poor,  it  is  usually  divided  in  the  proportion  of  two  thirds  of  poor 
crystals,  and  one  third  of  rich  liquid  metal ;  but  this  proportion  is  reversed  if  the  alloy 
contain  a  good  deal  of  silver. 

Let  us  exemplify,  by  the  common  case  of  a  lead  containing  10  ounces  of  silver  per  toa. 
Operating  upon  3  tons  of  this  alloy,  or  60  cwts.,  containing  30  oz.  of  silver,  there  will  be 
obtained  in  the  first  operation — 

(o)  40  cwts.  at  4  J  ounces  of  silver  per  ton ;  in  whole  9  oz.  >  on 
(6)  20  cwts.  at  21  —  -_  gl        5^"°^' 

Each  of  these  alloys,  (a)  and  (6),  will  be  joined  to  alloys  of  like  quality  obtained  in 
the  treatment  of  one  or  several  other  portions  of  three  tons  of  the  primitive  allov.  Agaia, 
three  tons  of  each  of  these  rich  alloys  are  subjected  to  the  crjstallization  process,  and 
thus  in  succession.  Thus  poorer  and  poorer  lead  is  got  on  the  one  hand,  and  richer  and 
richer  alloys  on  the  other.  Sometimes  the  mother  metal  is  parted  from  a  great  body  of 
poor  crystals,  by  opening  the  discharge-pipe,  and  running  off  the  liquid,  while  the  work- 
man  keeps  stirring,  to  facilitate  the  separation  of  the  two. 

25  fodders,  15  cwts.,  49  lbs.  —  540  cwts.,  49  lbs.  of  alloy,  holding  5  oz.  of  silver  per 
fodder,  in  the  whole  130  oz.,  afforded,  after  three  successive  crystallizations, — 


\ 


t 


t     ! 


638  SILVER. 

440  cwts.  of  poor  lead,  holding  |  oz.  of  silver  per  fodder;  in  aU 
I5cwts.49       —        holding  the  original  quantity,  nearly    - 
84  cwts.  oflead  for  the  cupel,  holding  29  oz.     ... 


116 


Total J3Q 

1  cwt.  of  loss,  principally  in  the  reduction  of  dross. 
The  expenses  of  the  new  method  altogether,  including  3«.  per  fodder  of  natent  dues 

in^eipenlesl-"'''  "^""^  '**^^'^'  *^^  treatment  of  argentiferous  le«d  occasions  the  follow- 

FOR  ONE  FODDER.  £      ,.      d. 

ay  tne  new  process     -        -        -        .        .        .        .        0     13     7 
By  the  old  process  -        -        .        .        .        .        -222 

tK^«°'fiI'""  ^^^\^^^  treatment  of  sUver  holding  lead  is  economically  possible  only  when 
St/w-^^'f.'^''^^  to  one  tenth  of  the  gross  expenses  of  the  process,  wVn.ay  easily  cllcu. 
tentsTn  silve^r?-*"       '         '  ^  sufficient  for  the  leiid  to  have  the  foUowing  coS 

With  the  new  process,  3  ounces  per  fodder;  or,     -        -        0*000078 

With  the  old  process,  8_4_  ounces  per  fodder ;  or,      -        -    0000218 

To  conclude,  the  refining  by  crystallization  reduces  the  cost  of  the  partin-  of  lead  and 

silver,  m  the  proportion  of  three  to  one;  and  allowsof  extracting  silverfom\  lead  which 

contains  only  about  three  oz.  per  ton.     In  England,  the  new  method  produces  at  p^sint 

IZed  "tires'  rr''''  Vr'f'/  '^  ^^'^^"^^  '^  '"^^  --^^  --»«-«  ^^  ^^7^ l  ^aTbe 
V^lfnln  h.H  iL  *  ^  '^"^"^'^^  ""^  "^^  ^''""^"y  ^-^^'•^^t^^  ^'^"^  the  mines  in  the  United 
Kingdom  had  been  progressively  raised  to  47,000  tons.  Reduced  almost  to  one  half  of 
this  amount  m  1832,  by  the  competition  of  the  mines  of  la  Sierra  de  Gador,  the  En^Ush 

r.  h«Tnrl'^  K  ^^r  V"  •""""'"  ^"  ^^^^'  ^"  ^«3^'  35,000  tons  of  lead  were  oSS, 
one  half  of  which  only  having  a  mean  content  of  eiaht  and  a  half  ounces  of  silver  per  ton 

^tlL"ffit?oVa?e^'''°"'  '"'  "'"'"'^  '''"'"  °"  ^'  ^"^  P^^"«"^  -etal!' xLTetaUs 

SUver  extracted  from  17,500  Ions  oflead,  holding  upon  the  average  ei-ht  > 

and  a  half  ounces  per  ton,     -        .        .        .        .        -        .         (140,000  02. 

SUver  extracted  from  sUver  ores,  properly  so  caUed,  in  Cornwall,    "  -  36,000 


176,000 


See  Smelting  of  Lead. 
•  I^}^V'  *f  production  of  lead  amounted  probably  to  40,000  tons:  upon  which  the 
introduction  of  the  new  method  would  have  the  effect  not  only  of  reducin/consideraWr 
the  cost  of  partmg  the  20,000  tons  of  lead  containing  8  oz.  of  silver,  per  ton  bu  of  ^? 
mittiDg  the  extraction  of  4  or  6  oz.  of  silver,  which  may  be  supposerto  eist  upol^ 
VZT.  '^  \  1  g'-eater  portion  of  the  remaining  20,000  tons.  Otterwiae.  this  mass  of  the 
precious  metal  would  have  had  no  value,  or  have  been  unproductive 
rJ.Jr'^''^'^^''i?  apparatus  of  Locke,  Blacket  and  Co.,  consists  of  seven  crystallizini? 
pots,  and  one  smaller  pot  for  receiving  the  desilverized  lead.  They  are  aU  made  of  S 
iron,  and  arranged  m  a  straight  line. 

The  lead  in  each  pot  varies  in  its  contents  of  silver. 


The  first  containing  86  cwt  lead  at  about  60  oz.  of  silver,  or  ^t.  per  ton 
Is  divided  into  55  cwt.  crystals  carried  to  second  pot,  at  36  o^pirton 
18  cwt.  do.  to  be  put  in  first  pot  again,  at  64  oz.  per  ton 
and  12  cwt  rich  lead  to  be  cupelled,  at  170  oz.  per  ton 

The  second  pot  containing  90  cwt  lead,  at  about  35  oz.  silver  per  ton 
Is  divided  mto  60  cwt  crystals  carried  to  third  pot,  at  20  oz.  per  ton 
and  80  cwt.  lead  put  into  first  pot,  at  66  oz.  per  ton 


oz. 

oz. 

• 

256 

•  96 

-  67 

-  102 



265 

. 

167 

-  60 

-  97 

w 


SILVER. 

The  third  pot  containing  90  cwts.  of  lead,  at  about  20  oz.  per  ton 
Is  divided  into  55  cwts.  crystals  carried  to  fourth  pot,  at  10  oz.  per  ton      - 
and  25  cwts.  lead  put  into  second  pot,  at  36  oz.  per  ton     - 

The  fourth  pot  containing  80  cwts.  lead,  at  about  10  oz.  per  ton 
Is  divided  mto  55  cwts.  crystals,  carried  to  fifth  pot,  at  5|  oz.  per  ton 
and  25  cwts.  lead  put  into  third  pot,  at  20  oz.  per  ton 

The  fifth  pot  containing  80  cwts.  lead,  at  about  5|  oz.  silver  per  ton  - 

Is  divided  into  55  cwts.  crystals,  put  into  sixth  pot,  at  3  oz.  per  ton    - 

and  25  cwts.  lead,  put  into  fourth  pot,  at  11  oz.  per  ton     - 

The  sixth  pot  containing  80  cwts.  lead,  at  about  3  oz.  per  ton    -        -        . 

Is  divided  into  55  cwts.  crystals,  carried  to  seventh  pot,  at  1|  oz.  per  ton  - 

and  25  cwts.  lead,  put  into  fifth  pot,  at  6  oz.  per  ton  - 

The  seventh  pot  containing  55  cwts.  lead,  at  about  1|  oz.  per  ton      - 
Is  divided  into  25  cwts.  crystals,  carried  to  small  pot,  at  1|  oz.  per  ton      - 
and  30  cwts.  lead,  put  into  sixth  pot,  at  2|  oz.  per  ton 


27 
63 


15 
25 


4| 


639 
90 

90 
40 

40 
22 

22 
12 

12 

4 


The  above  25  cwts.  of  crystals  are  melted  and  cast  into  pigs  and  sent  to  the  market. 

in  operating  upon  lead  containing  about  10  oz.  per  ton,  the  fourth  pot  is  filled  with 
It;  It  It  should  contain  20  oz.,  or  thereabouts,  it  is  put  into  the  third  pot:  and  so  of 
any  other. 

fig.  1298  represents  the  arrangement  of  the  iron  pots  or  caldrons,  in  their  order. 


The  desilvermg  apparatus  represented  m;2g.l298is  composed  of  five  caldrons  of 
cast  iron,  each  heated  by  its  own  fire,  besides  two  smaller  pots,  similarly  heated  The 
caldrons  rest  by  their  upper  flange  and  surface  upon  bricks  property  fomk  and 
arranged.  Theur  shape  is  not  hemispherical;  their  mouth  is  40  inches  in  len^  hm 
only  26  inches  in  width  Over  the  door  of  the  fireplace,  the  moutIS  stendfsVeet 
4  inches  above  the  ground  or  bottom  of  the  ash-pit,  of  which  space,  18  inchS^iL™« 
wtwecn  the  grate  and  the  brun.  The  grate  is  2  feet  long  and  8f  Lches  ^de  Tfl 
ThV?fth~«w*-'  ^^%'!^t«»ipt.i<^  form,  with  a  bottom  like  the  smiu  end  ^L  e« 
^nf  ^  ?  v^  •?  smaller,  but  this  one  serves  merely  to  melt  the  lead  which  hMbefn 
•tnpped  of  Its  silver,  in  order  to  be  cast  into  salmons  or  blocks.  ^^ 

The  charge  consists  of  64  or  65  salmons,  each  weighing  from  120  to  140  lbs     Wl,pn 
they  are  well  melted,  the  fire  is  removed  from  the  grate,  as  well  m  thp  LSi'  fii       ? 

posture  m  this  plane.  During  this  operation,  intended  to  establisra  un^or^^mnei 
ture  throughout  the  mass,  a  second  workman  heats  in  the  smaUe?  pot  XiS  to 
No.  1  a  large  skimmer  at  the  end  of  a  long  wooden  handle,  and  next  proceeds  to^fish 
out  the  crystals,  taking  care  to  let  them  drain  off  for  a  few  seconds  aU  The  lloud  leS 
«nong  them,  and  then  turns  ont  the  crystah,  slowly  into  the  next  ca?dron.  No  2^ 
the  second  workman  meanwhile  adds  the  metal  solidifi'ed  round  the  s  dS,  and  stiS  all 
together  to  equalise  the  temperature.    These  two-fold  operations  occ^pV  about  fifty 


,' 


i  ; 


640 


SILVER. 


mmxxtea  j  by  which  time,  there  remains  in  the  caldron  about  16  salmons.  The  workman 
now  lifts  out  the  crystals,  as  before,  with  the  drainer,  and  throws  them  upon  the  ground 
in  two  heaps.  His  assistant  takes  them  up  a  little  while  afterward,  and  puts  them 
away  to  make  room  for  fresh  crystals,  which  the  first  workman  continues  to  throw 

^^-"^^  J^  ^•°*'^'^  ^r-  T  *'"  ^''^y  ®  ^^°°^  '^"^^^^  i°  the  caldron,  a  point  ascer- 
tained by  gauging  the  height  to  the  bath.  The  fire  being  at  this  time  reioy«i  from 
cauldron  No.  2  into  the  grate  of  No.  I,  the  8  salmons  of  lead  enriched  with  silve^ 
which  remain  at  the  bottom  of  the  caldron,  are  run  out  into  movable  moulds ;  and  the 
8  salmons  which  were  thrown  upon  the  ground  are  put  into  it ;  the  full  charce  beinc 
then  made  up  with  salmons  of  the  same  richness  as  those  previously  used 

While  this  mass  is  melting  in  No.  1  the  process  just  finished  in  it  is  repeated  in 
No.  2.  About  three  fourths  of  the  metallic  mass  is  next  separated  in  the  state  of 
crystals,  which  are  transferred  to  No.  3,  and  also  one  eighth  of  crystals  thrown  on  the 

ground,  after  pouring  the  remaining  one  eighth  at  the  bottom  of  caldron  No.  2  not 
into  moulds,  but  into  No.  1.  »,  ^  uu^ 

A  like  process  is  performed  in  caldrons  3  and  4;  and  the  poor  lead  taken  out  of  4 
is  transferred  to  5  to  be  melted,  and  run  into  salmons,  which  are  submitted  afresh  to  the 
preceding  senes  of  crystallizations,  provided  the  lead  still  contains  a  sufficient  proportion 

The  following  Table  will  place  the  results  of  the  above  successive  operations  in  a 


clear  light : — 


Original  lead         ---•._ 

1.  Rich  crystals    ---«.. 

2.  Poor  ditto         ----.. 
— Rich    ditto  >  proceeding  from  the  treatment  of  the  prece- 

3.  Poor  ditto   $     ine  No.  2  poor  crystals 

4.  Rich  )  proceeding  from  the  treatment  of  No.  3  poor  crvs- 
— Poor  Stals r-j 

(Lead)poor  l  as  above  fitim  No.  4 


Silver  in  1  Ton  of  Lead. 
0-001153 
0-003324 
0-000933 
0-0020802 
0-0007021 
0-001399 
0-0004569 
0-0008135 
0-0001128 


We  thus  see,  that  four  crystallizations,  repeated  upon  the  original  lead  from  the 
smelting  furnace,  of  the  above  richness,  will  afford  a  lead  ten  times  poorer.  With  a 
lead  originally  containing  only  0-0002248  in  silver,  three  crystallizations  would  suffice 
to  make  It  ten  times  poorer.  In  general,  the  poorer  the  lead,  within  certain  limits,  the 
better  adapted  is  it  to  this  process. 

1    TK^'fl  T-  *I?  ^""'au  ''^J^''^''  ',  ^^^^^  *'^^°*^^  ^^'^^'  »°d  suroxide,  by  Berzelius 
1   The  first  IS  obiamed  by  adding  solution  of  caustic  potassa.  or  lime-water,  to  a  solutbn 
of  nitrate  of  silver.    The  precipitate  has  a  browhish-gray  colour,  which  darkens  wheS 
dried,  and  contains  no  combined  water.     Its  specific  gravity  is  Y-143.     On  exoosure 
to  the  sun,  It  gives  out  a  certain  (Quantity  of  oxygen,  and  becomes  a  black  powder 
This  oxide  18  an  energetic  base  ;  being  slightly  soluble  in  pure  water,  reacting  fike  the 
a  kalis,  upon  reddened  litmus  I>aper   and  displacing,  from  their  combinations  with  the 
alkalis,  a  portion  of  the  acids,  with  which  it  forms  insoluble  compounds.     It  is  iosolub  e 
m  the  caustic   yes  of  potassa  or  soda.    By  combination  with  caustic  ammonia,  it  forms 
fulminating  silver.    This  formidable  substance  may  be  prepared  by  DreciDitatin^  thp 
nitrate  of  silver  with  lime-water,  washing  the  oxide^upon^a  £ter,  anLpreX^  i^^upon 
gray  paper,  to  make  it  nearly  dry     Upon  the  oxide,  still  moist,  water  of  ammonia  isT 
be  poured,  and^allowed  to  remain  for  several  hours.    The  powder,  which  becomes  black, 
w  to  be  freed  from  the  supernatant  liquor  by  decantation,  divided  into  small  portion 
while  moist,  and  set  aside  to  dry  upon  bits  of  porous  paper.    Fulminating  silver  may 
be  made  more  expeditiously  by  dissolving  the  nitrate  in  water  of  pure  ammonia,  and 
I)recipitating  by  the  addition  of  caustic  potassa  lye  in  slight  excess.    If  fulminating 
silver  be  pressed  with  a  hard  body  m  its  moist  state,  it  detonates  with  unparalleled 
violence;  nay,  When  touched  even  w  th  a  feather,  in  its  dry  state,  it  frequentl^exp  odes 
As  many  persons  have  been  seriously  wounded,  and  some  have  been  killed,  by  these 
explosions,  the  utmost  precaution  should  be  taken,  especially  by  young  chemiste,  in  its 
preparation.     This  violent  phenomenon  is  caused  by  the  sudden  production  of  water 
and  mtrog^,  at  the  instant  when  the  metallic  oxidfe  is  reduced.  ^The  quiescent  and 

r'^tl  "iVf-^"  i!^'  '^•°'  *i^^  '''  °'^^^7  ^a^a^ced  in  this  curious  compound/that  the 
slightest  disturbance  is  sufficient  to  incite  the  hydrogen  of  the  ammonia  to  snatch  the 
oxygen  from  the  silver.  The  oxide  of  silver  dissolves  in  glassy  fluxes,  and  renders  them 
yellow.  It  consists,  according  to  Berzehus,  of  6311  parts  of  silver,  and  9-89  of  oxygen. 
2.  The  suroxide  of  silver  is  obtained  by  passing  a  voltaic  current  through  a  weak  solu- 
tion of  the  nitrate-  It  being  deposited,  of  course,  at  the  positive  or  oxygenating  pole 
It  18  said  to  ciystaUize  m  needles  of  a  metalUc  lustre,  interlacing  one  another,  whicharo 


SILVER. 


641 


one-third  of  an  inch  long.  When  thrown  into  muriatic  acid,  it  causes  the  disengage- 
ment of  chlorine,  and  the  formation  of  chloride  of  silver ;  into  water  of  amsionia,  it 
occasions  such  a  rapid  production  of  nitrogen  gas,  with  a  Iiissing  sound,  as  to  convert 
the  whole  liquid  into  froth.  If  a  little  of  it,  mixed  with  phosphorus,  be  struck  with  a 
hammer,  a  loud  detonation  ensues.  With  heat  it  depreciates,  and  becomes  metallic 
silver. 

Sulphuret  of  silver,  which  exists  native,  may  be  readily  prepared  by  fusing  the 
constituents  toorether;  and  it  forms  spontaneously  upon  the  surface  of  silver  exposed  to 
the  air  of  inhabited  places,  or  plunged  into  eggs,  especially  rotten  ones.  The  tarnish 
may  be  easily  removed,  by  rubbing  the  metal  with  a  solution  of  catneleon  mineral^  jM-epared 
by  calcining  peroxide  of  manganese  with  nitre.  Sulphuret  of  silver  is  a  powerful 
sulpho-base ;  since  though  it  be  heated  to  redness  in  close  vessels,  it  retains  the  volatile 
sulphides,  whose  combinations  with  the  alkalis  are  decomposed  at  that  temperature.  It 
consists  of  87-04  of  silver,  and  1296  of  oxygen. 

A  small  quantity  of  tin,  alloyed  with  silver,  destroys  its  ductility.  The  best  method 
of  separating  these  two  metals,  is  to  laminate  the  alloy  into  thin  plates,  and  distil  them 
along  with  corrosive  sublimate.  The  bichloride  of  tin  comes  over  in  vapours,  and 
condenses  in  the  receiver.  Silver  and  lead,  when  combined,  are  separated  by  heat  alone 
in  the  process  of  cupellation,  as  described  in  the  article  Assay,  and  in  the  reduction  of 
silver  ores.     See  suprd. 

An  alloy,  containing  from  one-twelfth  to  one-tenth  of  copper,  constitutes  the  silver 
coin  of  most  nations ;  being  a  harder  and  more  durable  metal  under  friction  than  pure 
silver.  When  this  alloy  is  boiled  with  a  solution  of  cream  of  tartar  and  sea-salt,  or 
scrubbed  with  water  of  ammonia,  the  superficial  particles  of  copper  are  removed,  and  a 
surface  of  fine  silver  is  left 

Oliloiide  of  silver  is  obtained  by  adding  muriatic  acid,  or  any  soluble  muriate,  to  a 
solution  of  nitrate  of  silver.  A  curdy  precipitate  falls,  quite  insoluble  in  water,  whidi 
being  dried  and  heated  to  dull  redness,  fuses  into  a  semi-transparent  gray  mass,  called, 
from  its  appearance,  horn-silver.  Chloride  of  silver  dissolves  readily  in  water  of 
ammonia,  and  crystallizes  in  proportion  as  the  ammonia  evaporates.  It  is  not  decom- 
posed by  a  red  heat,  even  when  mixed  with  calcined  charcoal ;  but  when  hydrogen  or 
steam  is  passed  over  the  fused  chloride,  muriatic  acid  exhales,  and  silver  remains. 
When  fused  along  with  potassa  (or  its  carbonate),  the  silver  is  also  revived ;  while 
oxygen  (or  also  carbonic  acid)  gas  is  liberated,  and  chloride  of  potassium  is  formed. 
Alkaline  solutions  do  not  decompose  chloride  of  silver.  When  this  compound  is 
exposed  to  light,  it  suffers  a  partial  decomposition,  muriatic  acid  being  disengaged. 
See  Assay  by  the  humid  method. 

The  best  way  of  reducing  the  chloride  of  silver,  says  Mohr,  is  to  mix  it  with  one-third 
of  its  weight  of  colophony  (black  rosin),  and  to  heat  the  mixture  moderately  in  a  crucible 
till  the  flame  ceases  to  have  a  greenish-blue  colour ;  then  suddenly  to  increase  the  fire, 
so  as  to  melt  the  metal  into  an  ingot 

The  subchloride  may  be  directly  formed,  by  pouring  a  solution  of  deuto-chloride  of 
copper  or  iron  upon  silver  leaf.  The  metal  is  speedily  changed  into  black  spangles, 
which,  being  immediately  washed  and  dried,  constitute  subchloride  of  silver.  If  the 
contact  of  the  solutions  be  prolonged,  chloride  would  be  formed. 

The  bromide,  cyanide,  fluoride,  and  iodide  of  silver,  have  not  been  applied  to  any  use 
in  the  arts.  Sulphate  of  silver  may  be  prepared  by  boiUag  sulphuric  acid  upon  the 
metal.  See  Refinikg  of  Gold  and  Silver.  It  dissolves  in  88  parts  of  boiling  water, 
but  the  greater  part  of  the  salt  crystallizes  in  small  needles  as  the  solution  cools.  It 
consists  of  118  parts  of  oxide,  combined  with  40  parts  of  dry  acid.  Solutions  of  the 
hyposulphite  of  potassa,  soda,  and  lime,  whidi  are  bitter  salts,  dissolve  chloride  of 
silver,  a  tasteless  substance,  into  liquids  possessed  of  the  most  palling  sweetness,  but  not 
at  all  of  any  metallic  taste. 

The  iodide  of  silver  is  remarkable,  like  some  other  metallic  compounds,  for  changing 
its  colour  alternately  with  heat  and  cold.     If  a  sheet  of  white  paper  be  washed  over  with 
a  solution  of  nitrate  of  silver,  and  afterwards  with  a  somewhat  dilute  solution  of  hydrio- 
date  of  potash,  it  will  immediately  assume  the  pale  yellow  tint  of  the  cold  silver  iodide. 
On  placing  the  paper  before  the  fire,  it  will  change  colour  from  a  pale  primrose  to  a 
gaudy  brilliant  yellow,  like  the  sun-flower ;  and  on  being  cooled,  it  will  again  resume 
the  primrose  hue.    These  alternations  may  be  repeated  indefinitely,  like  those  with  the 
salts  of  cobalt,  provided  too  great  a  heat  be  not  applied.    The  pressure  of  a  finger  upon 
the  hot  yellow  paper  makes  a  white  spot,  by  cooling  it  quickly. 
Fulminate  of  silver  is  prepared  in  the  same  way  as  Fulminate  of  Mercwry,  which  see. 
On  'the  10th  of  February,  1798,  the  Lords  of  the  Privy  Council  appointed  the  Hoc 
Charles  Cavendish,  F.  R.  S.,  and  Charles  Hatchett,  Esq.,  F.  R.  S.,  to  make  investigation* 
upon  the  wear  of  gold  coin  by  friction.     Their  admirable  experiments  were  begun  in 
the  latter  end  of  1798,  and  completed  in  April,  1801,  having  been  instituted  and  coa- 

41 


h 


I! 


iM' 


642 


SILVER. 


ducted  with  every  mechanical  aid  aa  r]ev;««>/l  kx,  *i.^ 

phers.and  provided,  at  no  stall  ex^nse^  the  ^^^^^^^^^  ^^'^"^ 

important  conclusions  of  their  officialVeport  :—*     S^^^ernment.    The  following  are  the 

"  Gold  made  standard  bv  a  mixture  of  pnnnl  rka-*-  ^t    m 
as  gold  alloyed  only  with  silveT^Ser  is   t  so^nat     f  "•!"''  *"^  "°PP^''  ''  °«'  «>  «oft 

and  stamped  with  great  facilitv-  «n!i  ,VnJ  ^  ^"'PP'^''-     ^*  "^^y  also  be  rolled 

le,«by  friction  than  |;i5'afq;!:7by'^u;:rtrp*;:^a'ire'"'^""'-  "  ''^^"'  '»  "^'' 
Of  ete.fe^r„  rtU*";:^^^  f-  the  s„rfa« 

be  preferred  for  coin."  ^^   "^^^"^  *°^  copper  is  rather  to 

any  scientific  reason  or  resS  anLrendv  fo?  rhJ  ^°*""^l^  '^'  **  °°"-»^^'  ^^^hout 
in  our  mint  a  good  job^n  sw^aU^^^^^^^  ^^  ^'^'"^  ^  ^^'"tain  official 

it.  in  the  newloina^e.  With Top^^^^^lf  o  ,11^^^^^  ^^  -PJ-ng 

ounce  of  our  excellent  gold  cdn  and  charging  tKunirvS/f!'  ''"\^^  '?'*' 
besides  the  very  considerable  exDen«;e  in  nrnviHmiV  ^  ^  ^""^  '^^  extraction. 
The   pretence   s-^t  up  for ISs  "rt^rd  n^^^^  ^P^-^  *'-,  -l-er 

coin  might  peradventure  be  exported  in  ord^r  tn  k1  ^  i  ^  ?*".'  '^^''  ^^^^  <>"' 
which  could  have  been  most  readilv  avert^l    L  ?.o^  de-si  vered  abroad,  a  danger 

sovereign  as  was  equivalenTtoX  s^lvVr   ntldu^ed^^^^^^^^^  n^^.""''    ^"^  '''  ""'^^ 

value  m  precious  metal.     When  the  film  of  fina  S     u-  u        P^^^serving  its  intrinsic 

pieces  has^  been  rubbed  offfrom  tie  prLfnent  n!r  f  7h  '^  '^'f '  '^^  "^  ^"^  P''^^^"' 
ferent  and  deeper  colour  tlian  thr/at  Tr!  ^  '  ^^^^o^^st  appear  of  a  very  dif- 
therefore,  is  suLently  appa'en '"^  ^^  '^?.  ^^      "  T^^«   '^^^^^ 

ailver  only,  cannot  be  hab?e^  to  thisUmUh  '^a^H  i'^^  '^  ^""^^^  with 

.be  much  jess  liable  to  it,  thaV  wu";  alol"^  ^rdrd  thl  -IV  ^^' ^'  ""«^ 
m  a  late  Committee  of  the  House  of  Common,  on  ?L  m- ^*  k,-  J^^e  pohtical  economista 
lie  economy  and  expediency  ?  Commons  on  the  Mint  blink  this  question  of  pub- 

Gold,  as  imported  from  America  Asia  anA  Af-Uo    ^     x  • 
right  proportion  of  silver  for  mScMhe  £t  t^^'.T^  ?  n"  ''^?'"^-"  "^"^^  ^^ 

standard,  of  22  parts  of  gold  1  orsilver  and  In?  '/  ^ere  it  alloved  to  our  national 
dish  and  Hatchett,  then  by  aim  pi  v  adding  Z  ifi.'  P^''  ^  ^^^""^^  ^^  ^^'''^  ^aven- 
metals,  by  the  rulk  of  allSn  the  very  consfd^^^^^^^^^^^  ^"""*'*'"^  "^  ?^\^'  *^«  ^^  th^^^ 
nation,  a/d  sulphureous  n^is^nce  to  the  VoZ  H^m^^^^^^^  ^  ^^^^^  *«  *»^« 

silvering  and  cuprifying  sovereigns  at  the  Rojal  Mir       '  ^°^'^'^  '^'"'"'""^  ^"  **«- 

Mexico  amounts  only  £,  from  0   8  to  O^fof  a    ' ;  f,  ^^f^.T'  T"'"L''^"^^^  ^" 
m  100  lbs.;  the  true'average  being,  perhaps,  no?  Tore  than  2^     U  L'ZV''-^  'T^' 

silvW  cCTs^^^ttd'^td'r  tt  ftlfe  'oVchrf  ^  ''^'  {'  -^«-  ^/  -^-    ^e 
thus  ascertained;  the  eh"  IfteV  h^W^g  tet' wd^^  f  "'^   -"^^ 

IS  to  be  put  into  a  stoppered  wide-necked  bottle  a  01^1  v  of  rpfinl^  ^''''^  ^^PP^'' 
candy,  is  then  added,  equal  in  weight  to  the  -illov  *  ^"?".^'*y  .^^  ,^6^^?^  ^"gar,  or  sugar- 
of  a  solution,  composed^  60  JaSs  of  ^o^  L/^  1  mixed  with  an  equal  volSme 
distilled  water,  which  will  vYdS^^lution^  o1^  n^tf  h^  f  J^o^^^'  *"^  ^^^  ^''^'^^^^  «f 
after  closing  the  bottle  the  mixture  i^  to  ^^  ^^u^    ,^.^T^'  ""'  t^^ereabouts : 

it  occasionSly,  to  favour  thrreacUon  After^thU  '  ^"f  l^'°  '^'  ^^  ^^  hours,  shaking 
several  times,  until  the  last  wa^h  n^^^^^  ^l  Z"'"^  ^1  "J"P'-'^'  '^ '«  *«  ^  ^^^^ed 

which  should  be  preceded  b;tn^'iSurpaT  ^l"  ct  ot^^^^^^^^^  l}^^^ 

or  show  any  change  whatever     Thl,  dnnp  tho  /.«JU     *    Y"'<^^  ought  not  to  become  blue, 

to  a  porce/ain  capsule,  byThe  he?;  of  ri  it  'rt^nr/ waVer^t^^^  t"^  '\T''T^ 

deposit  the  excess  of  licuid  is  poured  off,  and  tfetlveT  d^Ted  ^^^^^  's""^  ""'^'^  *^ 

By  these  means  we  o\tam  that  to  which  I  have  given  the  name  of^y  ,Uver.    Thi. 

♦  It  Is  inserted  in  the  PhUoeophical  TramacUom  for  1808L 


SILVER. 


643 


silver  consists  of  some  bright  spangles,  which  become  more  brilliant  on  friction.  It 
does  not  contain  any  impurities,  with  the  exception  of  a  small  quantity  of  oxide,  and  a 
few  atoms  of  chloride  of  silver.  This  latter  produces  a  slight  turbidity  in  the  liquor, 
when  dissolved  in  perfectly  pure  nitric  acid,  and  diluted  with  distilled  water.  Thia 
turbidity  does  not,  however,  prevent  the  formation  of  pure  nitrate  of  silver:  as  the 
Chloride  being  only  m  suspension  in  the  liquid,  it  is  sufficient  to  filter  it  on  a  small 
portion  of  well  washed  asbestos,  in  order  to  obtain  an  unobjectionable  liquor.  The 
nitrate  of  silver  will  not  contain  any  trace  of  other  metals,  as  none  are  used  in  the 
reduction  of  the  chloride  of  silver,  and  by  the  reduction  of  this  salt,  the  silver  is  com- 
pletely separated  from  the  iron  and  copper  which  the  solution  might  contain.  Thus  the 
nitric  acid  of  commerce  may  be  employed,  without  inconvenience,  for  dissolving   the 

The  grey  «7»ct-  almost  always  contains  a  small  quantity  of  oxide ;  this  is  easily  verified 
by  the  addition  of  ammonia,  which,  after  digestion  on  the  metal  and  filtration,  produces  a 
slight  turbidity  on  adding  mtric  acid,  which  is  caused  by  the  separation  of  the  dissolved 
chloride  of  silver;  the  turbidity  is  then  increased  by  the  addition  of  a  small  quantity  of 
chloride  of  sodium  to  the  nitrate  of  ammonia  previously  formed  ;  thus,  then,  is  the  oxide 
of  Sliver  dissolved  m  the  liquor  m  the  state  of  ammoniacal  nitrate,  which  is  precipiuted 
m  the  form  of  insoluble  chloride.  *^ 

Oxide  of  silver  not  being  an  impurity  in  the  uses  to  which  pure  silver  is  applied  in 
laboratories,  we  may  consider  the  grey  silver  obtained  in  the  manner  above  descnbed  as 
more  pure,  and  with  less  loss,  than  any  of  those  prepared  up  to  the  present  time,  by  the 
reduction  of  chloride  of  silver ;  and  without  the  necessity  of  melting,  a  troublesome  operation 
ana  one  of  much  inconvenience  in  a  laboratory. 

«i.f '*°°"i  T^.r''^''  ^°"*'  Spanish  franc),  the  weight  of  which  was  5759  grammes,  I 
^l^'^^t  t  •  /'S"?'''  ""^J""'^  *'''^''"'  ^"^  supposing  that  the  standard  wal  at  90  ^r 
cent,  which  IS  doubtful  as  the  money  of  Seville  has  often  an  infenor  standard,  I  obtained 
^Jj^'fT'  ""^  ??^  '"'''-^T  contained  in  the  alloy;  but  the  remainder  is  not  lost,  as  the 
waters  of  the  washing  acidulated  by  nitric  acid  are  poured  into  the  vessel  on  the  precipi- 
tates of  silver,  and  form  a  fresh  chloride.  ^      ^ 

*dt  fT'''"n  \^'^  mixture  for  the  purpose  of  obtaining  the  grey  silver,  it  will  be  observed 
irnln  i'*"^'^^^^^'  ^'"*=^;  ^«  ^^6  first  instauce  is  white,  changes  to  a  dirty  reddish- 
I^r?,  ^Z'\  ^,f """^yt  \^  \'o^\-}^^ted  grey  ;  and,  finally,  to  a  blackish-brown.  It 
^?vtM?  11  K  "^i"^'  !""'  *>","^  '^^^^  ""^  *'«"'■'  ^'  *^«  e"d  «^  ^hich  time,  the  whole  of 
tm^l  ^r  ^-  ^T^-  ^"tirely  covered  with  a  thin  layer  of  brilliant  silver,  forming  a 
^mplete  cyhndrical  mirror.    This  layer  wiU  remain  as  long  as  the  liquid  is  not  much 

^J^^  Z^u^  ''^''•'''-  «^^hich  I  treat  in  the  memoir  from  whence  this  note  is  extracted,  is 
obtained  by  precpitatir.g  oxide  of  silver,  and  oxide  of  copper,  by  potash,  then  reducing 
oxide  of  silver  by  sugar,  taking  certain  precautions ;  but,  from  the  alloy  only  46  per  cent 
of  SI  yens  obtained.  In  the  state  of  dead  silver,  it  is  as  white  as  pumice  stone  ;  and,  by 
simple  friction  with  a  g  ass  rod  it  assumes  considerable  briUiancy.  The  white  silver  is 
free  from  oxide  or  chloride— it  is  chemically  picre.  ^ 

Production  of  silver  in  Spain,  by  Frederick  Burr,  Esq.,  Mining  Engineer.   In  the  earliest 
ages  of  authentic  history,  Spain  was  one  of  the  countries  most  cdebrated  for  the  pr^ 

^^^'ZlJin  r  ^  "  '^^'.f  5^i""y  *J"  ^"**«^-  ^'  PhcEnicians  and  Cartha^  n  ansC 
said  indeed  to  have  freighted  their  ships  with  these  metals,  and  even  tohfveformid 
their  anchors  of  them.    On  the  subject  of  ancient  mining  ii  Spain  T  Spanllh  wrher 

fio  onn^K  P  7'  X?P^'^"  °^**^?"^  ^"""^"3^  f""""*  «*!"«».  the  Asturias  and  Lusi  S 
♦h;?p  «./p'- ""^  f  ^1'  f  we  are  informed  by  Pliny,  who  extols  the  quanUty  of  gold  S 
ISS^^i!rHP^'f  1^'^^  '"  ^"^^  ^''""^'-     '^'^^  «"^«^  «f  Spain  was  found  in  such  quantity 
that,  according  to  the  same  author,  Hannibal  in  a  mine  worked  by  him  nearCartTena 
extracted  daily  a  quantity  which  exceeded  80.000  reals  (300/.)  of  ™ur  money      Cato 

4SoTi:L  of'lV  a'll'TwZh?'?:  '^-  °'  '""r  ^"  ^^^«  *"^  120.00oTn  money'^-besidt 
400  Itw.  ot  gold  all  of  which  he  had  accumulated  in  Spain.  Helvetiu<»  who  was  onlv 
governor  of  Andalusia,  delivered  3Y,000  lbs.  of  silver  in  ^in,  and  40.00^  C  of  Tver  In 

rpmorW?«fTif '""  • '^''''^'  of  the  production  of  the  precious  metals  in  Spain.  I  would 
diSo  er  L  of  s^e?^  t"^'  their  coiTectne^ss.  both  from  the  resuTt  of  mo<lem 

Crh^Tnian  mtl^r^^^^  h^^Vstrw'i^htt^-  h'^^'^^''^  ^^"^"r^"' 

i/,ff  K^  ti.o  o.,«:«.,f     •  "°  ^'^^^y^'^**'-    /  nave  seen  with  astcmishment  the  vast  excavations 

whilp^hl!  '"  *^!  feierra  Almagrera  and  in  the  neighbourhood  of  Cartagena; 

Tw  '.IV  r  "^T^'  of  ancient  scoria  on  the  coast  of  the  Mediterranean  near  the 
f^Lrl  nn  ?f'  Ti.^^^  ^^'^^  ^^i-^^tivity  with  which  metallurgical  operations  were 
earned  on  in  the  south  of  Spam  Within  the  last  few  years  most  of  thSe  mounds  of 
ancient  scoria  have  been  re-smelted,  and  with  considerable  profit 


644 


i 


M 


SILVER. 


^(A%ZZ^^^  -  the  subject  till  the  .idd,» 

industnr  in  Spain.  The  precious  metals  weTe  at  ^ if  r^  the  Second  to  revive  mining 
nch  sifver  mines  of  Guiialcanal  wSe  SVered  andT^.^^^  '\"^^^  ^^'^'^  ^^  '^« 
Silver  mines  were  also  discovered  at  cLa  kit  Ooi!  '^^^  "^  *^«  Sierra  Morena. 

range;  these  are  described  as  1^4  verTricVat ^fe^  w  1^}''  P^^^«  '»  *^«  ^^^^ 
declined  after  a  few  years'  working  an7fn\i,  u  ^"l®'  ^"*  ^^^J  ^  appear  to  have 
16th  or  beginning  of  the  mh  centu^  Of  tht^'''  abandoned  ^bout  the  end  of  the 
authentic  records%vere  preserved  during  the  p^rim? "^^"1"^"^  ^^^  "^'^^^'^  «°^ 
government.  In  these  ft  is  stated  to  h .L  !l  ^  i.L^^^  worked  on  account  of  the 
twenty  years  after  its  disc^ve!^  l.*S  wl^^^^^^^ 
passed  into  the  hands  of  the  wealthv  ami  !IfioT   Tj  r^  *,     ^^^^^'    ^^^^r  this  period  it 

to  have  obtained  immense  tre^Somtrem^^^^^^      ^' —  'J  '^'  F^^^''^^'  who^are  said 
filling  with  water.  ''^'''"  *^^  "^'"^  previous  to  its  being  abandoned  and 

revvaf  of  mining,  wh^ich  dates  Sck  only  from  1825     ^f  ^',o  ^r°71'''  ''"''^  "">  ^"^"t 
Sierra  Almagrcra,  in  the  province  ofAWrU  i       r     1839  the  celebrated  mines  of  the 

recent  and  minor  disLe  iea  I  m^^ta  'e  tha^w?tWn7l,  P'"^."?'™-    P'^'ng  over  more 
of  Mr.  Pattinson'a  desilverizinR  processhas  hLrl.  ^',  f*'' /«"«  "«  introduction 

prl^e^lrof^^|[5S£H=^^^^^^^ 

of  the  Sierra  /imagrmTnT  MnrSt  Z ^nf thi  yt^  C""l''8'i;*'"'i"'T' '''"™'" 

Srre^LfLsr^Tootd^-f^^^^^^^^^ 

theSierra  A.ma/era-2t:^  S^    o^^eSt^  Hrrnt^^K^r^ 


Tear& 


Silver,  in  marca* 


1841 
1842 
1848 
1844 
1846 
1846 
1841 


Total  in  the  seven  years. 


10,178 

56,676 
143,331 
159,285 
144,829 
185,141 
103,985 

752,926  marc5. 


have  declined  considerTbW  3Cd  fcount  of  th^?  ft.  "'"'  ""'"•'''  »"<'  Foduclion 
level,  and  partly  from  harinVml^  wi.^  wL°    ■    ¥  'f^"  ^"""'"g  Poorer  below  a  certain 

have  neces  Vbeen^ns^n^r'  rs'jm'4  ^nf C-hrvIr'^at  len'^ T  ^*"^^'!? 

mines  in  the  year  1850  wm  40  m?  r^tt.!  ^r  ^:?*'^<^*^«n-     The  produce  of  the  Almagrera 

about  the  saL  ;  for  aUrugh  1L  rk^mfnes  JiL"^^  ^'^^^^  ^'"^^  *^^"  '^^^-^^ 
other  discoveries  have  been  madp  in  tL^"  ai  '^^*'^''  ^^^^  continued  to  decline, 
ward,  which  will  ha;;Sribufed  ?o  W  u^^^^^^^^^  ^V^"^*^"  ^"^^  ^^  ^^^  ^e^t-' 

Of  the  produce  of  the  m^«s  nf  w;!?  i^  ■       /T^"*  P'-^'l^ction  of  silver. 

although  Lre  uniform  thrtUoMhfLTerr^^^^^  ""\T°  1°^  «^*^°^^"*'  ^* 
inferior  to  it  ^  ^'®'^'^*  Almagrera,  it  has  been   considerably 

gm^eVSl^jItea\n'''^^e'3';?es™"C^^^^^  ""^  *™™-  «-'/ 

traordinary  size,  being  in  places  6  or  R to,  i      ^         '^'^^  "/  *^®  '^^^''^^  '"'"es  is  of  ex, 

Cbiefl,  argWo.  WK^idUr^re^rur^^b-uV^^^f*.^^^^^^^ 

•  Tb«  oonees  havo  bean  hare  omitted. 


SILVERING  OF  GLASS. 


6^ 


rate  state.  The  lodes  of  Hiendelencina  run  nearly  east  and  west ;  they  seldom  exceed 
3  feet  iu  width,  and  are  properly  silver  lodes,  as  they  produce  the  ores  of  silver,  ss 
chlorides  and  sulphurets,  but  unmixed  with  any  ores  of  lead.  The  Silver  of  the  Sierra 
Almagrera  has  been  almost  entirely  exported  to  Marseilles— that  of  Hiendelencina  is 
•ent  to  Madrid.  The  silver  coinage  of  Spain  has  not  been  therefore  by  any  means  so 
considerable  as  might  be  inferred  from  her  large  production  of  that  metal.  It  is  stated, 
however,  that  in  the  year  1850,  the  total  quantity  of  silver  coined  in  Spain,  in  the  three 
mints  of  Madrid,  Barcelona,  and  Seville,  amounted  to  the  value  of  27,780,319  reals,  or, 
in  round  numbers,  about  280,000/.  sterling ;  the  silver  proceeded  chiefly  from  the  mines 
of  Hiendelencina  and  Sierra  Almagrera,  exclusive  of  course  of  the  bar  silver  which  was 
exported. 

Mr.  R  H.  "Wilson,  Consul  for  Peru,  estimates  the  produce  of  the  Peruvian  mines  at 
about  5,210,000  dollars  a-year;  about  3,500,000  dollars  of  this  amount  are  exported  on 
English,  French,  German,  and  Spanish  account 

The  whole  annual  production  of  Europe  and  Asiatic  Russia,  has  been  rated  by 
Humboldt  at  292,000  marcs  ;  by  other  authorities,  at  810,000 ;  while  at  the  beginning 
of  the  present  century,  that  of  the  Spanish  colonies  in  America  was  3,849,160  marcs,  or 
nearly  twelve  times  as  much.  The  sum  total  is  3,704,160  marcs,  of  3609  grains  troy 
each  ;  which  is  nearly  1,900,000  lbs.  avoirdupois ;  that  is,  little  less  than  9000  tons. 

The  whole  of  the  mines  of  the  Zmeinsgorsk  Circle  have  yielded  an  aggregate  of 
183,884,116  poods  of  ores,  from  which  have  been  extracted  69,708  poods  of  silver,  con- 
taining a  quantity  of  gold  estimated  at  1,900  poods. 

We  are  indebted  for  the  following  valuable  tables  to  M.  Michel  Chevalier's  Remark* 
on  the  Production  of  the  Precious  Metals,  translated  by  D.  Forbes  Campbell,  Esq. 

Comparative  Table,  showing  the  annual  Produce  (approximate  Calculation)  in  value 
of  fine  Gold  and  Silver,  for  1846  and  1850,  the  former  being  Two  Years  before,  the 
latter  Two  Years  after  the  Discovery  of  the  Gold  Mines  in  California. 


California  -  - 
United  States 
Mexico  -  -  - 
New  Grenada 
Peru  -  -  -  . 
Bolivia  -  -  - 
Chili-  -  -  . 
BfHzil    -    -    - 


Total  of  North  and 
South  America    - 


1846. 


Gold. 


237,336 
249,7.W 
252,407 
96,24 1 
60,337 
145,585 
259,871 


Silver. 


1,864 

3,457,020 

42,929 

1,000,583 

460,191 

297,029 

2,003 


Total. 


1,301,560 


Russia  -    -    -    - 
Norway  -    -    -    - 
North  Germany  - 
Siixony  -    -    -    . 
Austria  -    -    -    . 
Piedmont  -    -    - 
Spain    -    -    -    -    . 
United  Kingdom     ' 
Africa    .    -    -    .    . 
Borneo  -    -    •    -    . 
Ava  .----, 
Malacca      -    -    .    , 
Sumatra     •    ■    .    . 
Annan  or  Tonquin 
Various  countries*  ■ 


Total  of  Europe, 
AOica,  and  Asia  - 

Total  of  North  and 
South  America    - 


3,414,427 
357 


5,261,619 


282,750 

17,841 

3,498 


203.900 
305,900 
100,000 
72,240 
63,719 
30,585 
50,975 


4,545,192 
1,301,560 


Total 


5,846,752 


167,831 

32.346 

138,022 

198,200 

282,654 

7,444 

227,499 

109,989 

1,056 

1,584 

517 

374 

330 

53,460 

33,000 


239,230 
3,706,773 
295,336 
1,096,824 
520,548 
442,614 
261,874 


1830. 


Gold. 


6,563,179 


1,254,306 
5,261,619 


3,582,258 

32,346 

138.379 

198,200 

565,404 

25.285 

229,997 

109,989 

204,956 

307,484 

100,517 

72,614 

64,049 

84,045 

83,975 


6,515,925 


5,799,498 
6,563,179 


£ 

12,000,000 

115,430 

382,901 

252,407 

96,241 

60,357 

145,5p5 

289,068 


Silver. 


13,341,989 


4,175,860 

357 

288.708 

17,841 

2,498 

203,900 
305,850 
100,000 
72,240 
63,719 
30,585 
50,975 


5,312,533 
13,341,989 


12,362,677     18,654,522 


£ 

62,088 

11,444 

5,383,333 

42,929 

1,000,583 

460.191 

297,029 

2,227 


Totel. 


7,259.824 


171,817 

35,607 

138.022 

198,200 

286,971 

7,444 

440,210 

160.000 

1,056 

1,584 

517 

374 

330 

53,460 

33,000 


1,528,592 
7,259,824 


£ 

12,062,088 

126,874 

5,766,234 

295,336 

1,096.824 

520,548 

442,614 

291,295 


20,601,813 


4,347,477 

35,607 

138,379 

198,200 

575,679 

25.285 

442,708 

160,000 

204,956 

307.484 

100,517 

72,614 

64,049 

64,045 

83,975 


6,840,975 
20,601.813 


8,788,416      27,442,788 


*  Exclusive  of  China  and  Japan,  which  produce  large  quanUties  of  gold  and  silver,  the  amount  of 
which  18  quite  unknown  to  Europeans.  *  «"•»",  «jc  ouiuunk  ui 

n  ???^■i;^.hi^i^n!f'^r'"/  f  '?v'^.K  ''^i'^S'^'  ."*'*»°  Humboldt's  estimate  (Sssai  PolUiqus,  tome  ii , 
SAih  inH  ^Sl^iTiJ^r^^''^*'  ?%\^^^^  America  was  17,591  kilogrammes  -  46,331  lbs.  troy  of 

ra  V^J  ^h  ''''oerammes-.  2,131  770  lbs.  of  silver ;  value  of  both  metals  in  dollars,  43,500.00ol  to 
V^i^Lh  ^,K®  produce  of  Europe  and  Northern  Asia  at  the  same  time  was  4,916  lbs.  of  gold,  250,593i  • 
Korth^  Arii'io  152 OaS  '  °^  ^^  ^'^^°"'  ""^^^  raised  in  Americ^  K^rop;/^;^ 


646 


M  ■   .' 


■H 


SILVER. 


The  following  table  is  similar  to  the  ahovA  nrl*\>  ♦u-       ^     i- 
eubstituted  for  values.  ®'  ^'^^  *^®  exception  that  quantuea  art 


•California 

United  States •---. 

^flnL*^oki!°  ^^'  ^^  *^®  ^"'"^  washing  98o"lbs. 

*VoW^'  ''^  "P®*^"**"  °^  parting,  3,920  lbs.  fine 

^lT«n  r"^  ^■~*°  *^^'  '^y  ^''e  English  Colom-i 
In  ll^    K**  Company.  343  lbs.  fine  gold. 

J^'.7'*/.K^  «  ^"^'i^'^  Marmato  Gold  Com- 
Pe?r  -    -    -    .    ®  *.  **:  *"**  ^^  ''^  ^°«  »"^er.  J 
Bolivia ".""""'" 

^abou?n^;  fl^  '^^  .?"«''i^  ^"«Po"  Compa'ny; 

•  Rr^rn      1^  iflr^^l^'"*'  '^^  T.oodlbs.  fine  silver 
rTv  r"Ti"p^^^'  ^^  ^,^«  En?ri9h  St.  John  d'eH 
5»  L?  J^  Company,  1425  lbs.  gold,  containing 
•«o  per  cent,  silver.  * 

1850,  by  ditto,  2,517  lbs.  gold,  containing  20  per 
cent,  silver.  *^ 

1846,  by  the  English  Imperial  Brazilian  Gold 

S^r^cffiiJ^eV"  ^°'''  ^^''^"'°«  '^^^^  " 
1850,  by  ditto,  379  lbs.  gold,  containing  about  14 

per  cent,  silver. 
1846,  by  the  English  National  Brazilian  Gold 

Company, 89  lbs.  gold,  containing  about  14  per 

Ociii*  Silver* 
1850,  by  ditto,  120  lbs.  gold,  containing  about  14 

per  cent,  silver. 


I'otal  of  North  and  South  America 
Russia:— 1846,  by  private  mines  in  the 


J 


Ural 8,125  lbs. 

Public  ditto-  -  -  5,672  lbs. 
Private.  Siberia  -  57,235  lbs. 
Public  ditto-    -    -    2,555  lbs., 

73,587  lbs. 


9  per  cent } 
alloy.      J 


Norway  (Kongsberg  silver  mines) 

North  Germany  (Hartz  Mountains)     -    -    -    . 
Saxony ' 

Austria,  in  1846,  by  private  mines,  about  4,100 
lbs.  pure  gold,  and  34,400  lbs.  pure  silver      Bv 

fi!H®^S^",K™'"*'^'  "**«"*  ^'*^^  'bs.  pure  gold, 
and  51,200 lbs.  pure  silver  -    -    -    -   .   .*     ' 

Piedmont     ---------..,.* 

Spain  -------....I"'*" 

United  Kingdom  -----.1111" 

•Africa    ------.-.   .11*3" 

*  Borneo  ------.••111"'" 

*Ava  --- -Ill*'* 

*  Malacca-    -------.III''" 

•Sumatra    -------IIIII^' 

Annan  or  Tonqnin    --~...ll''' 
Various  countries  -    ---.-..'"" 


TotalofEurope,  Africa,  and  Asia-    -    - 
Total  of  North  and  South  America  -    -    - 

Grand  Total 


184& 


Pur*  Gold. 


Lbf.  Troy. 

4,625 
4,900 

4,954 

1,888 
1,184 

2,856 


5,096 


25,503 


66,985 


5,549 

350 

49 


4,000 
6,000 
1,961 
1,420 
1,250 
600 
1.000 


89,171 
25,503 


Put*  tr.lrer. 


Lbt.  Troy. 
565 

1,047,582 

13,009 

303.207 
139.452 

90,009 


1850. 


Pure  Gold. 


Lb«.  Trey. 
235.409 
2,263 

7,509 


4,954 

1,888 
1,184 

2,856 


Pur«  Silver. 


Lb«.  Troy. 
18.814 

3,165 
1,631,313 


13,009 

303,207 
139,452 

90,009 


607 


5,668 


675 


1,594.431 


261,731 


50,858 


9.802 
41,825 
60,606 


85,653 

2,2.56 

68,953 

33,330 

320 

480 

157 

113 

100 

16.200 

10,000 


2,199,644 


81,919 


384.653 
1,594,431 


5,663 

350 

49 

4,000 
6,000 
1,961 
1,420 
1,250 
600 
1,000 


52,053 


10,790 
41.825 
60,606 


86.961 

2.256 

133.397 

48,484 
320 
480 
157 
113 
100 

16,200 

10,000 


Enrope,  Africa,  and  Asia 
247  lbs.  British  standard 


gold  - 18,654,322^.  ^     ^'       '        ''*'• '  ^^^  Produce,  365,950  lbs.  -  399, 


•  Those  countries  marked  thus  C*i  havn  *,«  o«i..« 
having  existed  in  the  native  gold.'^to  We  JJI^a^e  aSoSntTs"  "I  I^Ji'' '  '"^^  «" 


average  amount  of  8  per  cent. 


Iver  stated  is  estimated 


SILVER. 


64*) 


Total  Production  of  the  Silver  and  Gold  Mines  of  America  prior  to  the  Discovery  of  th« 

Gold  Mines  of  California. 


Ootmtriei. 


United  States     -   -   - 
Mexico  ------ 

New  Grenada     -    -    - 

Peru      ; 

Bolivia )     -    -    -    -    - 

Brazil    -...-- 
Chili 

Totals 


Silver. 


Weight  in 
Kilogramme*. 


61,985,522 
259,774 

58,765,244 
1,040,184 


122,050,724 


V»lne  in 

Miliiona  of 

FrHDcs. 


V3,774 
58 

13,059 
251 


27,122 


Gold. 


Weight  in 
Kilogrammes. 


22,125 

389,269 
566,748 

340,393 

1,342.300 
250,142 


2,940,977 


Value  in 

Milliotu  of 

Fraoc*. 


76 
1,341 
1,952 

1,172 

4,623 
862 


10,026 


ToUl  for  each 
Country 

in  Miliiooa  of 
Francs. 


76 

15.115 
2,010 

14.331 

4.623 
1,093 


37,148 


'  (I 


Quantities  of  Gold  and  Silver  supplied  to  the  European  Markets  by  the  undermentioned 

Countries  during  three  Centuriies  ending  in  1848. 


Countries. 

Silver. 

Gold. 

Weight  in 
Kilogramme!. 

Value  in 

Millions  of 

Francs. 

Weight  in 
Kilogrammes. 

Valne  in 

Miliiona  of 

Franca. 

Europe,  exclusive  of  Russia 

Russia -.- 

Africa,  and  the  Islands  of  the  Malay  Archi- 
pelago, Sec.  --.-----.- 

9.000.000 
1,485,000 

2,000 
300 

445,1.50 
319.330 

725,750 

1,500 
1.100 

2,500 

Totals 10,485,000 

2,330 

1,490,230 

5,100 

Gold  and  Silver  produced  in  Forty  Years,  from  1790  to  1830. 


Mexico, 
ChUe, 

Buenos  Ayres, 
Russia, 


Gold. 


£6,436,453 
2,768,488 
4,024,895 
3,703,743 


Sihrer. 


;£  139,8 18,032 

1,822,924 

27,182,673 

1,502,981 


Returns  of  the  Dollars  coined  at  the  different  Mints  in  Mexico. 


Mexico 

Guanajuato 

Zacatecas 

Guadalaxara    - 

Durans^o 

San  Luis 

Ilalpan 

Total 

1829. 

1830. 

1831. 

1834. 

1,280,000 

2,406,000 

4,505,000 

596,000 

659,000 

1,613,000 

728,000 

1,090,000 

2,560,000 

5,190,000 

592,000 

453,000 

1,320,000 

90,000 

1,386,000 

2,603,000 

4,965,000 

590,000 

358,000 

1,497,000 

323,000 

952,000 
2,703,000 
5,527,000 

715,000 
1,215,000 

928,000 

11,787,000 

11,295,000 

1 1,722,000 

12,040,000 

The  English  Mint  silver  contains  222  pennyweights  of  fine  silver,  and  18  of  copper,  m 
the  troy  pound  of  240  pennyweights  :  or  92-5  in  100  parts.  1  pound  troy  =  6760  grains, 
•ontains  65-8  shillings,  each  weighing  87-55  grains.      The  French  silver  coin  contains 


H$ 


SILVERING  OF  GLASS. 


^M&l^^f  ^^a^^l^^Srr^V^f  ^-^-  ^-y-      ^e   Prussian 
343-7  grans  troy,  and  contains  257-9  ^J^^Z'tJ  'T''  ^^"^«  ^  '^^^^  ^-gh» 

^  h^  "^  r"^^'     '^^^  ^"«t"«"  *^oin  Sains    ^"ofj'  ^'"^  '^^  P^""  ^^"^-  ^^  silver. 

i?ri?r?2^^rti  per  cent.  "''""'  ^*8  of  alloy,  according  to  Wasserburg 

SILVER  LEAF  is  made  in  precisely  the  «.m. 
"""s/r  vrmv'/^^^'-  ^^^  ^^«^^'-  '^  "^  *^''^  ''«-^'  *«  ^»''<=h  article  1 

"■'"•.f-^'-by  fheFr„ci;"aS  "*'"'  '""  """■'"»«  "-  -*«  of  .he  copper, 

rteel,  of  various  forms.     The  workman  hi-      v'  ^^^T  ^"  "'  ««'-<'ace  bv  burnisher,  nf 
any  part  darken  i„  the  hea J^lJ^rbe^S^^^^  ^'^  ^^^^  do«ble"^'''|i^,^S 

The  silverer  always  works  two  piece!  «nn^«  ^  »>yihe  scratch-brush.  ^'^ 

bomishing  the  other.     After  apT^yin'two  sZ/i  '"  ^^l  ^^  "^^^  ^^^'  ^he  one  while 
the  same  degree  as  at  first,  and  he  tien  fixes  on  withTh'^k^"  '"."^^  ^'^'  "P  the  pieTe  to 

nas  applied,  one  over  another,  30  40  50  nr  fin  i  '  '  "  *  leaves  at  a  time  till  h. 

of  the  silverins.    He  then  burnfahes  do^n  J?i.  t"""?'  '""'''"''«  '»  the  dJZ'sMikt 
''sX'^'"L'''?/""'^°™'''«^»'p«""^       ^        P«s.areand  address,  fVhthiJ 

ShftlnT  «J  "-is  powder  is  toT  mLS  w  ,h  3  plrS'of  ^U'  "''!  "«"«"  «'"l  driei 
whiting,  and  one  and  a  half  of  sea  salt      Aft.r  m.    ■      ?v  ^"^  Peariash,  one  of  washeH 

net.lrr°"  ?""'■""■'  3  Po^nrolsuUT^  JfTn?  °^.""""^''^«  'Sa'te,  3 
1  he  buttons  being  cleaned,  are  smeared  over  wirh  tl,»,     •     '  '""'  *"e'.  '"to  a  paste. 

T^^r  button  t.us  acquires  a  silvery  ^  "  w£l^  t^^^^  ^^^^ 

..;r;;h':n1h7X^r^S^^^trnrr  ^'  ^^-^'^-^^  »-^  -  «Pmt  .amish  to  th^ 
SILVER^G  OF  GL  \SS     A    P'^^f «"»•«.  *^        ^^'^n'sh,  to  the  But. 

mirrors,  is  deposited  on  glass  by  Vhe'' fo  lofvil '' l''^'"'  "^'J  ^I  *'"  ""^^^am  as  on  ,-.ommon 
n»Tounded  with  a  raise^d  bord^er  of  g  Ws^  i^^;?rf  ^.  ^^^  The  plated  ng 

u.trat«  of  sdver,  with  which  a  little  alXl  'vaTe/^f  f  '"  -"^'^'^l  ^^''^  *  ^"'"^^on  of 
doves,  have  been  mixed.  The  silver  is  precin  t  [ted  h  T"'*'  '^^  -•'"^  ^'^  «^  ^''^'»  a«4 
oik  m  a  metallic  state.    This  method  wi^et  s^^^^^^^    'T*'""  1  '^''  ^^^^hol  and 

Be^ve  10  sUver  sraaU  irregular  and  polygooal 


SINGEING  OF  WEBS. 


ea 


TOTfaces  of  glass  very  conveniently ;  but  the  cost  of  the  precious  metal,  Ac.  will  preclude 
Its  application  to  large  mirrors. 

Mr.  Dmy  ton  has  patented  a  plan  of  making  looking  glasses  and  omameutal  mirrors  by 
«oatiug  gl^s  with  silver  mstead  of  mercury.  He  makes  a  mixture  of  nitrate  of  silvw 
(1  oz.),  with  half  an  ounce  of  water  of  ammonia  and  2  oz.  of  water,  which  after  atanding 
for  24  houi^  IS  filtered ;  (the  deposit  upon  the  filter,  which  is  silver,  being  preserved^ 
*nd  an  addition  is  made  thereto  of  3  oz.  of  spirit,  (by  preference  of  spirit  of  wine),  at 
60  above  proof,  or  wood-spirit ;  from  20  to  30  drops  of  oil  of  cassia  are  then  added,  and 
after  remain.ng  for  about  6  hours  longer,  the  solution  is  ready  for  use.  The  glas.«.  to  be 
silvered  with  this  mixture  must  have  a  clean  and  polished  surface;  it  is  to  be  placed  in  a 
borizontal  position,  and  a  wall  of  putty  or  other  suitable  material  formed  round  it-  so 
that  the  solution  may  cover  the  surface  of  the  glass,  to  the  depth  of  from  an  ei<'hth  to  a 
quarter  of  an  inch.  After  the  solution  has  been  poured  on  the  glass,  from  6  to°12  droos 
of  a  mixture  of  oil  of  cloves  and  spirit  of  wine,  (in  the  proportion  of  one  part  by  measure 
of  oil  of  cloves  to  three  of  spirit  of  wine),  are  dropped  into  it  at  diflFerent  places,  or  the 
diluted  oil  of  cloves  may  be  nuxed  with  the  solution  before  it  is  poured  on  the  gl^s  •  the 
more  oil  of  cloves  is  used,  the  more  rapid  will  be  the  decomposition  of  the  silver  but  it 
Is  preferable  to  effect  it  in  2  hours  at  soonest.  When  that  has  taken  place,  the  si>lution 
IS  poured  off,  and  as  soon  as  the  silver  on  the  glass  is  quite  dry,  it  is  varnished  with  a 
composition  formed  by  melting  together  equal  parts  of  bee's  wax  and  tallow  The  solu- 
tion after  being  poured  off  is  allowed  to  stand  for  3  or  4  days  in  a  close  vessel  -  as  it  still 
contanis  silver  it  may  again  be  employed  after  filtration,  and  the  addition  of  k  sufficient 
supply  of  fresh  ingredients  to  replace  those  which  have  been  used.  The  patentee  states 
that  he  has  found  that  about  18  grains  of  nitrate  of  silver  are  needed  foT  each  «;quare 
foot  of  glass ;  but  the  quantity  of  spirit  varies,  from  evaporation,  with  the  temperature 
ot  the  air  and  the  duration  of  the  process. 

If  the  glass  be  placed  in  an  inclined  or  even  .in  a  vertical  position,  and  the  surface 
covered  over,  leaving  a  narrow  space  for  the  solution  between  the  surface  of  the  glass 
and  the  cover  which  fits  close,  then  by  using  spirit  without  water  in  the  mixture,  the 
object  will  be  accomplished.  The  colour  of  the  sQvcr  may  be  varied  by  adding  a  little 
oil  of  thyme  or  carui.  j  &  ^ 

Oil  of  cassia  varies  much  in  quality  as  found  in  different  shops;  and  if  when  mixed 
with  the  solution,  it  becomes  flaky,  the  solution  must  be  filtered  before  being  applied 

SILVERSMITH'S  STRIPPING  LIQUID,  consists  of  8  parts  of  sulphuric  acid  and 
1  part  of  nitre.  r  r 

SIMILOR,  is  a  golden-coloured  yariety  of  brass. 

SINGEING  OF  WEBS.  The  old  furnace  for  singeing  cotton  goods  is  represented 
to  longitudinal  section,/^.  1299.,  and  in  a  transverse  one  in  ^.  1300.    a  is  the  fire- 


door  ,  b,  the  grate ;  c,  the  ashpit ;  d,  a  flue,  6  inches  broad,  and  2^  high,  over  which  a  hoi- 
low  semi-cylindrical  mass  of  cast  iron  e,  is  laid,  one  inch  thick  at  the  sides  and  2^  thick 
at  the  top  curvature.  The  flame  passes  along  the  fire  flue  d,  into  a  side  opening  /; 
in  the  chimney.  The  goods  are  swept  swiftly  over  this  ignited  piece  of  iron,  with  con- 
siderable friction,  by  means  of  a  wooden  roller,  and  a  swing  frame  for  raising  them  at  anv 
moment  out  of  contact.  °  ^ 

In  some  shops,  semi-cylinders  of  copper,  three  quarters  of  an  inch  thick,  have  been  sub- 
stituted for  those  of  iron,  m  singeing  goods  prior  to  bleaching  them.  The  former  last 
three  months  and  do  1500  pieces  with  one  ton  of  coal ;  while  the  latter,  which  are  an 
mch  and  a  half  thick,  wear  out  in  a  week,  and  do  no  more  than  from  500  to  600  pieces 
with  the  same  weight  of  fuel.  '^ 

In  the  early  part  of  the  year  1818,  Mr.  Samuel  Hall  enrolled  the  specification  of  a 
patent  for  removing  the  downy  fibres  of  the  cotton  thread  from  the  interstices  of  bobU- 
net  lace,  or  muilins,  which  he  effected  by  singeing  the  lace  with  the  flame  of  a  gaa- 


960 


SINGEING  OP  WEBS. 


feabo':':  pr:'a;^:^:LS^^^^^  f^^J^,  ^V-lms.  L,  for  an  improvement 

through  the  interstice;  of  thri^^^as  itTL«  ♦u^  J'*"  ^  ^'"^^  ^^^  A^^e  of  the  gas 

in  a.tSbe  placed  immediately  a^VeX^rr^SL^^^^  ^'^'''''  «^  ^  ^P^*^ 

an  air-pump  or  exhauster.  gas-jete,  which  tube  communicates  with 

-%.  1301.  shows  the  construction  of  the  aDDaratna  Anmr.i«# 
opera..  ;  „.  a,  .  a  ga^pipe.  .applied  by  LS^^Slt  ,"?l"T/;ilt'^' 

loOl 


r 


a 


Tnr  fa   fcfrf 


a 


passes;  and  when  it  is  ignited  the  tobbine.  ff-T       "It'  """"S''  "'''<=''■  "'  J'*'.  the  «S 
.  emended. da.wnfapid,>„^e^tl^^^^^^^^ 

cat!^  Hotd^-^TI^^tif^-eTeV^iol^^^^^^^^^  '?  '»«  ^om-e.  speeifi- 

^t1'bjrj'„^r--'-^iri^^^^^^ 

exhausting  apparatua  communicates  with  the  pipe  e,  e,  e,  which  leads  to  the 

.nJ?J^t;en^^^  filled  with  water, 

beam  fe;  each  of  the  boxes  is  furnished  wilh  a  valve  nnl'       ^^  '^^i  **"  *^'  ^^^^''^""^ 
extending  from  the  horizontal  part  of  thelipe/up  inTthp^iJJP^"'^' '   ^',arepip4 
which  p,pes  have  valves  at  their  tops,  alsoTpeiing  ipwald      mL^'t."^''''^' ^."i  ^ 
scends,  the  water  in  the  tank  forces  ou   the  air  containSTwrt**.;    .t^  the  vessel  h  de- 
m  ;  but  when  that  vessel  rises  again,  the  valve  ^bp^^  m      ?  lu^  ""^'"^^  «'  *^«  ^^^^e 
the  pipe  e,  through  the  pipe  /.     The  same  take^^l.^^^    ]u^^^'  *^^  ^^'  ^^  ^'"^^^n  from 
.ir  in  its  descent  is  expelled  through  "Lvalve^lnnS  '^^.r'^'^ »'»  ^^^^  which  the 
through  the  pipe  /,  from  the  Di^eL^hJ^\^J'    "^' '"  •**,'  *'<^^"t'  ^''^ws  the  ait 
in  the  pipe  .,.,  and  the  tube  J  c      to  sunnlv  wWh"  *V*  PP^^^l  ?J»«««tion  is  effected 
force  through   the  long  opening  of  ihe  Zlfl       ^\  ^^^  ^''  '"'^^«  ^'^^  considerable 
gas-burners!      The   bobbfnet  ifce    or  Xr  ^rS^f !  •""''  ^^'^  ^*  *»^^   ^^^^^  «f  *»>« 
between  the  burner  6,  6,  an?  the  eihauste^^^^^^  h'""  "«^  j^^^wn  over  the  flame 

the  flame  of  the  gas  is  foLd  through   L'^.'  '.'■  ^^  "/*"'  of  rollers,  as  above  said, 

filaments  and  loose  fibres  of  the   hiead  arl  burn  'nT''-.K^  '^'  ^^^"^'  ^"'^  ^"  »^«  fi"« 
the  goods.  *'''^^*''  ^^^  *"""*  °ff»  without  damaging  the  substance  of 

suspended  by  a  cord  or  chaln^'ssU  ov-^^^^^^^^  ^"  ^.l^  ^^"^^  ^^  ^ 

IS  also  a  scraper  introduced  inio  the  lube  c  which  k  m«2  I  ^^  ^  ^^'^^^  P'    There 

to  revolve  and  slide  backwards  and  forwardrfor  th.T*^^'  ^^  *7  convenient  contrivance, 
ler  that  may  arise  from  the  /oX^sinTed  aj^d  '  l^^.V^^^^^^^^  of  removing  any  light  mat! 
passage.  Two  of  these  draught  tubes  rmav  Zlf  ^^^  otherwise  obstruct  the  air 
apparatus,  when  a  double  row  of  burners T/emni^?^  .*"?  ""^^"^  ^«  '^^  exhausting 
may  be  directed  upwards,  downward  or  ./I?^^''^''^'  ^5?  ^^'  inclination  of  the  flame 

in  the  draft  tube,  by  which  ransaS'^i^^^^^^^^  ' -'^'  '''''''"  "^  '^'  '^^ 

both  sides  at  one  operation  ^  description  of  goods  may,  if  required,  be  singed  oq 

The  greater  part  of  the  bobbinet  lace  made  in  England,  is  sent  to  Mr.  HaU's  work^ 


SLATES, 
w™'!^!"^"  ^*\"^°«H°^  t?  ^  singed;  and  at  a  reduction  of  prices  truly  wonderfiil 

SKIN  (Peau,  Ft.  ;  /fatt/,  Germ.),  the  external  membrane  of  animal  bodies,  consists  of 
three  layers :  1.  the  epidermis,  scarf-skin,  (Oberhauty  Germ.)  ;  2.  the  vascular  organ,  or 
papillary  body,  which  performs  the  secretions ;  and  3.  the  true  skin,  (Lederhaut,  Geri.), 
of  which  leather  is  made.  The  skin  proper,  or  dermoid  substance,  is  a  tissue  of  innumer- 
anie  very  delicate  fibres,  crossing  each  other  in  every  possible  direction,  with  smaU 
orifices  between  them,  which  are  larger  on  its  internal  than  on  its  external  surface.  The 
conical  channels  thus  produced  are  not  straight,  but  oblique,  and  filled  with  cellular  mem- 
brane ;  they  receive  vessels  and  nerves  which  pass  out  through  the  skin  (cutis  vera),  and 
are  distributed  upon  the  secretory  organ.  The  fibrous  texture  of  the  skin  is  composed 
oi  the  same  animal  matter  as  the  serous  membranes,  the  carlilases,  and  the  cellular 
tissue ;  the  whole  possessing  the  property  of  dissolving  in  boiling  water,  and  being,  there- 
by, converted  into  glue.     See  Glue,  Leather,  and  Tan. 

SLAG  (Laitier,  Ft.  ;  Schlacke,  Germ.),  is  the  vitreous  mass  which  covers  the  fused 
metals  m  the  sroellmg-hearths.  In  the  iron-works  it  is  commonly  called  cinder.  Slan 
consist,  m  general,  of]  bi-silicates  of  lime  and  magnesia,  along  with  the  oxydes  of  ir^ 
and  other  metals ;  being  analogous  in  composition,  and  having  the  same  crystalline  form 
as  the  mineral,  pyroxene.     See  Copper  and  Iron. 

SLATES  (.^rdoises.  Ft.  ;  Schiefem,  Germ.)  The  substances  belonging  to  this  clan 
may  be  distributed  into  the  following  species  :  —  5    6        uus  cia» 

1.  Mica-slate,  occasionally  used  for  co-     5.  Drawing-slate,  or  black  chalk. 


6.  Adhesive  slate. 

7.  Bituminous  shale. 

8.  Slate-clay. 


vering  houses. 

2.  Clay-slate,  the  proper  roofing-slate. 

3.  Whet-slate. 

4.  Polish ing-slate. 

1.  Mica-slate.  —This  is  a  mountain  rock  of  vast  continuity  and  extent,  of  a  schistOM 
domi'na!!  *^^'°P®^^'*  °'  *^®  minerals  mica  and  quartz,  the  mica  being  generally  pre- 

2.  C/ay-5/a^c._.  This  substance  is  closely  connected  with  mica ;  so  that  uninterrupted 
transitions  may  be  found  between  these  two  rocks  in  many  mountain  chains.  It  is  a 
simple  schistose  mass,  of  a  bluish-gray  or  grayish-black  color,  of  various  shades,  and  a 
ahinmg,  somewhat  pearly  internal  lustre  on  the  faces,  but  of  a  dead  color  in  the  cross 
Iracture. 

Clay-slate  is  extensively  distributed  in  Great  Britain.  It  skirts  the  Highlands  of 
Scotland,  from  Lochlomond  by  Callender,  Comrie,  and  Dunkeld  j  resting  on,  and 
r^dually  passing  into  mica-slate  throughout  the  whole  of  that  territory.  KcifinR- 
slate  occurs,  on  the  western  side  of  England,  in  the  counties  of  Cornwall  and  Devon  • 
in  various  parts  of  North  Wales  and  Anglesea ;  in  the  north-east  parts  of  Yorkshire! 
near  Ingleton,  and  in  Swaledale ;  as  also  in  the  counties  of  Cumberland  and  Westmore! 
land.  It  IS  likewise  met  with  in  the  cqunty  of  Wicklow  and  other  mountainous  distrieU 
OI  Ireland. 

All  the  best  beds  of  roofing-slate  improve  in  quality  as  they  lie  deeper  under  the  suit 
face ;  near  to  which,  indeed,  they  have  little  value. 

A  good  roofing-slate  should  split  readily  into  thin  even  lamince ;  it  should  not  be 
absorbent  of;  water  either  on  its  face  or  endwise,  a  property  evinced  by  its  not  increasing 
perceptibly  in  weight  after  immersion  in  water;  and  it  should  be  sound,  compact,  and 
not  apt  to  disintegrate  in  the  air.  The  slate  raised  at  Eisdale,  on  the  west  coast  of 
Argyllshire,  is  very  durable. 

CUaving  and  dressing  of  the  slates.— The  splitter  begins  by  dividing  the  block,  cut 
lengthwise,  to  a  proper  size,  which  he  rests  on  end,  and  steadies  between  his  knees.  He 
uses  a  mallet  and  a  chisel,  which  he  introduces  inio  the  stone  in  a  direction  parallel  Ic 
thejolia.  By  this  means  he  reduces  it  into  several  manageable  pieces,  and  he  gives  to 
each  the  requisite  length,  by  cutting  cross  grooves  on  the  flat  face,  and  then  striking  the 
Slab  with  the  chisel.  It  is  afterwards  split  into  thinner  sections,  by  finer  chisels  dex- 
terously applied  to  the  edges.  The  slate  is  then  dressed  to  the  proper  shape,  by  being 
laid  on  a  block  of  wood,  and  having  its  projecting  parts  at  the  ends  and  sides  cut  off 
with  a  species  of  hatchet  or  chopping-knife.  It  deserves  to  be  noticed,  that  blocks  of 
Hate  may  lose  their  property  of  divisibility  into  thin  laminae.  This  happens  from  long 
exposure  to  the  air,  after  they  have  been  quarried.  The  workmen  say,  then,  that  they 
have  lost  their  waters.  For  this  reason,  the  number  of  splitters  ought  to  be  always 
proportioned  to  the  number  of  block-hewers.  Frost  renders  the  blocks  more  fissile; 
but  a  supervening  thaw  renders  them  quite  refractory.  A  new  frost  restores  the  faculty 
w  splitting,  though  not  to  the  same  degree;  and  the  workmen  therefore  avail  themselves 


! 


(I 


W52 


SjVIELTING 


fllj 

I 


ktrtTawr^  ^^^""^^    ^  Succession  of  frosts  and  thaws  renders  the  qoarried  Hoclfs  quit* 

k»  ti^'lf ''^'^  *""  '^'''^^  ^"^^^  '^  *  ^^^*y  ^«ck,  containing  a  great  proportion  of  ouartz 
te  which  the  component  particles,  the  same  as  in  clay-sllte  Sd  m^aSate  Imt  in^' 
Cerent  proportions,  are  so  very  small  as  to  be  indiscernible.  ' 

imti^. w  *"^''"'^-,  r^'^'''"'  c^a«»-yellow,  in  alternate  stripes ;  massive •  composition 
«npalpable ;  principal  fracture,  slaty,  thin,  and  straight ;  cross  fracture  fine  ewS^  S 
ft^Ki  "'T''  ^^^"^^'  little,  if  at  all,  to  the  tongue;  is  VCTy%oft  Sn«^  into 
til  LT't^""  ^i^""'^^ }""  ^^^  ^^y  state,  0-6;  when  imbued  with  moSureiT' It  S 
•apposed  to  have  been  formed  from  the  ashes  of  burnt  coal.  It  S  foun d'at  Pl«nit? 
•ear  Zwickau,  and  at  Kutschlin  near  Bilin  in  Bohemia?  "^  "^  ^^^"'^^ 

^c;i„  K  T'"''"*^'']'''  ?/■  ^''''*'  ^^"'*= '  ^«s  »  grayish-black  color :  is  very  soft  sectile 
easily  broken,  and  adheres  slightly  to  the  tongue;  spec,  ffrav  2^1  The  .tr?«b  5 
glistening.  It  occurs  in  beds  in  primitive  and  tranWirclf^slkte  alsJL  seco\^^^^^ 
iZTlZ  '  ^'  '"^  ^^^-  ^°^l-^^as«'-es  of  most  countries.  It  is  used  n  cmyon  drawing 
Us  trace  upon  paper  is  regular  and  black.  The  best  kinds  are  found  in  SpaTn  Italy  and 
^  ^/''"'/^r^.^'^'V^'^^  "^^"^^  ^^'^ '"  Caernarvonshire  and  in  "hSid  of  Islay 
ashinfn^s'jrk  11^''  *>"^'  peenish-gray  color,  is  easily  broken  or  exfoliated,  h« 
a  stimmg  streak,  adheres  strongly  to  the  tongue,  and  absorbs  water  raoidlv  with  th^ 
emission  of  air-bubbles  and  a  crackling  sound.  ^    ^'  ^^^ 

Kit;;rr,o''"'"uT*  '^""^^^M  »  species  of  soft,  sectile  slate-clay,  much  impregnated  with 
bitumen,  which  occurs  in  the  coal-measures.  impregnaiea  wiin 

inhfJft'f''^'^^^  a  gray  or  grayish-yellow  color;  is  massive,  with  a  dull  glimmer- 
ing lustre  from  spangles  of  mica  interspersed.  Its  slaty  fracture  approaches  at  tCTto 
earthy;  fragments,  tabular ;  soft,  sectile,  and  very  frangible;   speciKravit^  L-fi      I? 

?s  ?S  '"  '''  'T^"''  ""'  f""^'^^  ^°^"  when  immer'sedfor  some  ti^rii^waln 
nnSer"pxTco"  t''Th?n^r^^  coal-measures.     (See  the  sections  of  7hesirata 

fi^efrom  w:L  .^*^^"  5'^eathed  upon,  it  emits  a  strong  argillaceous  odor.     When 
free  from  lime  and  iron,  it  forms  an  excellent  material  for  making  refractory  fire-bricks 
^mg  an  infusible  compound  of  alumina  and  silica;  one  of  the  best  exSefof  wh^^^^^ 
•^UT  Tni^a''  Hn?"^"  ^^  ^^  "«°^^  of  Stourbridge  clay.  examples  oi  wnich 

fomiati^n  "^""^  ^'""''  ^^  **""  ^^"""^'^  "^°^"  ^  ^^^^^  ^^^'  of  more  modern 

SMALL  WARES,  is  the  name  given  in  this  country  to  textile  articles  of  the  tane 

fand    narrow  bmdmgs  of  cotton,  linen,  silk,  or  woollen  fabric;  plaited  S!h  ^rdbm? 

Ac.  Tapes  are  woven  upon  a  loom  like  that  for  weaving  ribl^ns,  wh^  isTow  J^t 
rally  dnven  by  mechanical  power.  Messrs.  Worthington  and  Mulliner  o£"ed  a  pftent 
2:^^V  'f"'  "'  '^Pro^-rnents  in  such  a  loom,  which  have  answered  the  pu^^^^^^^ 
then-  large  factory  ,n  Manchester  very  well;  and  in  May,  1831  Mr  WhiteheaTof  th* 
«me  town  patented  certain  improvements  in  the  manufacture  of  Jalwar^' '^'^ 
^bjects  of  the  latter  patent  are,  the  regular  taking  up  of  the  tap^or  cbS  as  it  ij 
woven,  a  greater  facility  of  varying  the  vibration  of  the  lay.  togethe?  whh  the  ivhi^  of 

tsMALT,  see  Azuee  and  Cobalt. 

SMELTING,  is  the  operation  by  which  the  ores  of  iron,  copper,  lead  <fec  are  reduciw! 
to  the  metallic  state.    See  METALLURay,  Ores,  and  the  reiecSre  metals      '  ^ 

Smelting  of  lead  by  H.  L.  Fattinson,  Esq.  F.RS.^fhe  process  of  smelting  miiv 
be  most  conveniently  described  under  four  heads,  viz .«  ^  smelting  may 

Roasting  of  the  Ore. 

Smelting  in  the  Ore  Hearth. 

Smelting  in  the  Slag  Hearth. 

Smelting  of  Hearth  Ends  and  Smelters'  Fume. 

The  manner  of  conducting  the  process  of  roasting  is  the  same  in  all  casp-     THp  r^rorv*.. 

tX^"  "^  rf."  T'^^  ''T^y  "^^'-  *^^  ^^  °f  the^furnace Tthe  Sep^of  t J^  or'^  hSS 

nrSed  and    Jarred"  in  o'^^'^^.f  T,'"^*^^^,:  '"""^^  ^^'^^  the' or:  iXu  n% 
lurnea  ana  stirred,  in  order  that  the  whole  may  be  nn  formly  heated    but  care  is  to  hL 

ta^en  hat  no  part  is  prematurely  fused.  If  the  fire  is  judicio^usly  manned  Te  char^ 
gradually  attains  a  dull  red  heat-a  greater  heat  is  the-'n  given.  LTthTore  vtorousS 
?  t-'u  i^"'  -I'-^^-^l^f  *'"'^'  '^  ^^'"«  *°  ^^^1  «>ft  and  adhere  slightirto  tlie  t3 
m  which  state  it  is  withdrawn  from  the  furnace.  The  roasting  pro<Sss  if  Suited  in  ?he 
best  manner,  when  great  care  is  taken  to  apply  the  heat  vei^  gently  at  first.  To  keep,  b? 

♦  Newton'8  London  Journal.  voL  xiii  p.  192 ;  and  vol  I.  Combined  Series,  p.  219. 


SMELTING. 


653 


constant  stirring  and  change  of  place,  the  temperature  of  the  whole  charge  ns  unifonn  a« 
possible,  and  to  withdraw  it  at  the  proper  time  from  the  furnace. 

After  the  furnace  is  properly  heated  and  working,  two  Winchester  bushels,  or  about 
li  cwt.  avoirdupois,  of  free  coal,  are  required  to  roast  one  bing  of  ore ;  but  some  varieties 
of  ore  can  be  more  easily  reduced  into  the  pasty  state,  mentioned  above,  than  others; 
that  is,  they  fuse  at  a  lower  degree  of  heat,  and  this  in  proportion  to  their  purity.  The 
least  fusible  ores  are  generally  the  most  difiicult  to  smelt,  and  undergo  the  greatest  loss 
in  that  operation.  It  is  well  known  that  a  considerably  greater  produce  of  lead  can  b© 
obtained  frona  the  same  ore  after  being  properly  roasted,  than  before.  This  difference  is 
of  course  variable,  but  in  some  instances,  20  biugs  of  roasted  ore  have  yielded  8  or  9  cwt 
more  lead  than  20  bings  of  the  same  ore  smelted  in  its  raw  state. 

At  nearly  all  smelting  mills  long  horizontal  chimneys  or  flues  are  constructed  (generally 
on  the  slope  of  an  adjacent  hill  if  practicable),  which  the  smoke  from  the  various  pro- 
cesses of  smelting  is  made  to  traverse  before  it  escapes  into  the  atmosphere.  As  the  heat 
of  the  furnace  in  roasting,  if  incautiously  applied,  may  volatilize  a  portion  of  the  ore,  and 
the  draught  has  a  tendency  to  draw  along  with  it  some  of  the  smaller  particles,  the  fume 
from  the  roasting  furnace  is  conveyed  into  this  flue,  where  the  heavy  metallic  portion  ia 
deposited. 

Smelting  in  the  Ore  Hearth, — The  furnace  in  which  the  roasted  ore  is  reduced  into  lead 
18  called  an  ore  hearth.  Its  construction  is  almost  exactly  the  same  in  all  smelting  houses 
m  the  north  of  England,  and  seems  to  have  undergone  but  little  alteration  from  a  very 
remote  period.  It  may  be  briefly  described  as  a  square  furnace,  close  on  three  of  iu 
Bides,  and  open  towards  the  bottom  of  the  fourth.  Immediately  in  front  of  this  opening 
18  placed  a  sloping  cast-iron  plate,  the  upper  edge  of  which  is  4^  inches  above  the  bottom 
of  the  furnace,  forming  a  reservoir  of  that  depth,  in  which  the  reduced  lead  accumulates, 
and  out  of  which  it  flows,  through  a  channel  in  the  plate,  into  a  pot  below,  after  the 
reservoir  becomes  full 

In  proceeding  to  smelt  by  means  of  an  ore  hearth,  two  workmen  are  required  to  be  in 
attendance  from  the  beginning  to  the  end  of  each  smelting  shift,  the  duration  of  which  is 
from  12  to  15  hours.  The  first  step  in  commencing  a  smelting  shift  is  to  fill  up  the 
hearth-bottom,  and  space  below  the  workstone  with  peats^  placing  one  already  kindled 

J  ^if  '°®  "°^^^®  ^^  ^^^  bellows.  The  powerful  blast  very  soon  sets  the  whole  in  a  blaze, 
^  °y  J^®  addition  of  small  quantities  of  coal  at  intervals,  a  body  of  fire  is  obtained  fill- 
mg  the  hearth.  Roasted  ore  is  now  put  upon  the  surface  of  the  fire,  between  the  fore- 
stone  and  pipestone,  which  immediately  becomes  heated  red  hot  and  reduced  •  the  lead 
from  It  sinking  down  and  collecting  in  the  hearth  bottom.  Other  portions  of  ore  of  10 
or  12  lbs.  each  are  introduced  from  time  to  time,  and  the  contents  of  the  hearth  are  stirred 
and  kept  open,  being  occasionally  drawn  out  and  examined  upon  the  workstone,  until 
the  hearth-bottom  becomes  full  of  lead.  The  hearth  may  now  be  considered  in  its  regular 
working  state,  having  a  mass  of  heated  fuel,  mixed  with  partly  fused  and  semi-reduced 
ore,  called  Brouze,  floating  upon  a  stratum  of  melted  lead.  The  smelting  shift  is  then 
regularly  proceeded  with  by  the  two  workmen,  as  follows  :— The  fire  being  made  up  a 
stratum  of  ore  is  spread  upon  the  horizontal  surface  of  the  brouze,  and  the  whole  suffered 
to  remain  exposed  to  the  blast  for  the  space  of  about  five  minutes.  At  the  end  of  that 
time,  one  man  plunges  a  poker  into  the  fluid  lead,  in  the  hearth  bottom  below  the  bronze 
and  raises  the  whole  up,  at  different  places,  so  as  to  loosen  and  open  the  bronze,  and  iil 
doing  so,  to  pull  a  part  of  it  forwards  upon  the  workstone,  allowing  the  recently  added 
ore  to  sink  down  into  the  body  of  the  hearth.  The  poker  is  now  exchanged  for  a  shoveL 
with  a  head  6  inches  square,  with  which  the  brouze  is  examined  upon  the  workstone.  and 
any  lumps  that  may  have  been  too  much  fused,  broken  to  pieces ;  those  which  are  so  far 
j^glutinated  by  the  heat,  as  to  be  quite  hard,  and  further  known  by  their  brightness, 
bemg  picked  out,  and  brown  aside,  to  be  afterwards  smelted  in  the  slag  hearth  They 
are  called  "grey  slags. '  A  little  slaked  lime,  in  powder,  is  then  spread  upon  the  brouze^ 
which  has  been  drawn  forward  upon  the  workstone.  if  it  exhibit  a  pasty  a^arance ;  and 
a  portion  of  coal  is  added  to  the  hearth,  if  necessary,  which  the  workman  knows  bi  ex- 
perience. In  the  mean  time,  his  fellow  workman,  or  shoulder  fellow,  clears  the  opening, 
through  which  the  blast  passes  into  the  hearth,  with  a  shovel,  and  places  a  peat  iinmeth' 
ately  above  it,  which  he  holds  in  its  proper  situation,  until  it  is  fixed,  by  the  return  of 
all  the  brouze  from  the  workstone  into  the  hearth.  The  fire  is  made  up  again  into  the 
shape  before  described,  a  stratum  of  fresh  ore  spread  upon  the  part,  and  the  operation  of 
Btirring,  breaking  the  lumps  upon  the  workstone,  and  picking  out  the  hard  slags  repeated, 
after  the  expiration  of  a  few  minutes,  exactly  in  the  same  manner.  At  ever?  stirring  a 
fresh  peat  is  put  above  the  nozzle  of  the  bellows,  which  divides  the  blast,  and  cause?  it 
to  be  distributed  all  over  the  hearth  ;  and  as  it  bums  away  into  light  ashes,  an  opening  ia 
left  for  the  blast  to  issue  freely  mto  the  body  of  the  brouze.  The  soft  and  porous  nature 
of  dried  peat  moss  renders  it  very  suitable  for  this  purpose  ;  but,  in  some  instances,  where 
a  detiaeocy  of  peats  has  occurred,  blocks  of  wood  of  the  same  size  have  been  used  with 


i 


654 


SMELTING. 


Ill  ol  f  fi?  T-  ^-  the  smelting:  proceeds,  the  reduced  lead,  filtering  down  through 
all  parts  of  the  brouze  into  the  hearth  bottom,  flows  through  the  channel  out  ^  whidb  S 
18  laded  into  a  proper  mould,  and  formed  into  pigs.  cnannei  out  of  which  it 

The  principal  particulars  to  be  attended  to  in  manaffino"  an  nro  k^o^^k  i      j    • 

the  smelting  shift,  are  these:   First-It  is  very Tm^rfa^Hrem; W ^p^^^^^ 
which  should  be  carefully  regulated,  so  as  to  be  neither  too  weak,  S>r  tL  poC?M    T^ 
hl^il  blast  would  not  excite  the  requisite  heat  to  reduce  the  ore?  and  onrtl^TwerM 
has  the  effect  of  fusing  the  contents  of  the  hearth  into  slags.     In  ihis  pardc^ar^no  cer 
ta.n  rules  can  be  given  ;  for  the  same  blast  is  not  suitable  for  every  L?etrof  ore     Soft 
free-grained  galena,  of  great  specific  gravity,  bein?  verv  fuaiblp  La  TS       J     j 
quires  a  moderate  blast ;  while  the  hLer  a^Syer  WiS 

In  all  cases,  it  is  most  essential,  that  the  blast  should  Se  no  more  than  sufficient  tnr?l!.o 

-The  blast  should  be  as  much  divided  as  possible,  and  made  to  pass  throu.^h  ever^Dart 
nlrt  nf  ^r"'%  ^^"•^— The  hearth  should  be  vigorously  stirred,  at  due  fntervall  ^nd 
lit  U  K    J^"^^'^*^ «^P«««^, "P«"  the  workstone ;  when  the  partially  fused  lumns  should 
pfcS  out     Thi'^s  tS  ""?  ''• "  "*^"^.  '''  '"'■*^^''  -t"fied.^so  as  to^form  slag"^^^^^^^^^^ 
So  ^  L-  ;        u    ^^^^^'""S^  Pjeces,  and  exposure  of  the  hottest  part  of  the  br.  uze  u^n 

itr^     """f '  ^^-  ^  "^f'  ^""^"'^^  ^^^^t  i°  promoting  its  reductionlto  lead    for  C 
atmospherical  a.r  immediately  acts  upon  it,  ancf  in  that  heated  state  the  sdohur  is  r.lmt 

ItT^^fZ  '"T^'f^  ^"i"  f  "^P^T""^  acid,  leaving  the  lead  in  £  metal  icstlte    het^ 
It  IS  that  the  reduced  lead  always  flows  most  abund^tly  out  of  the  hearth  irrnnedSv 

take  place,  when  it  is  considered,  that  n  smelting  bv  means  of  thp  orl  v.o{.!i    •!       f 

^n,ai„,  impedes  the  smelting  procesa.  and  in™  tL  quiw;':fICs     ^;e^J^ 
difference  of  composition  of  perfectly  dressed  ore  ma^  rp^,in«  ki      ?    ^!*    j    ^®1  *"^"^ 
reducibility;  and  hence  it  is, Wore  froTdlffereH^^^^^  ^^  f  :^"'  '''' 

strata,  as  before  observed    s  freauentlv  fo3  to  J!l  '       the  same  vein  m  different 
singly  in  the  hearth.     It  ha^peLTherl^^^^^  ^**«"  «'"«'t^ 

of  ore  require  more  coal  anTlim;,  and  a  ^^^^^^^^^^  Cee  oftatThan^'othp""'  'T^'' 
for  this  reason  that  the  forestone  is  made  moyeabirS  1  eitW  'tn  !  7  '  """^  t  ? 

works  with  a  large  or  small  quantity  of  brouze       '  ^''^'^^'  ^'"'  ""'^  ""^'^^ 

en^or.^^:l^:':^ety^^^^^  'o  15  hours,  at  the 

necessary  to  stop  for  some  tlV^oTder^^^^^^^^  ^^t.  and  it  is 

shift  is  12  hours,  the  hearths  usually  go  on  12  houM  ^d  .t  ZVt  ^^/  smohmg 

half  or  five  bings  of  ore  (36  to  40  cwU  are  smpUp/S  «"«pended  5  ;  four  and  a 

who  manage  the  hearth  each  work  fo,7r«h?ft!  n^     ^,  ^"/'"^.^  «hift,  and  the  two  men 
at  8  o'clock  on  Wednesly  aftr^tn^^^^^^^^^  terminating  their  week's  work 

also  work  four  12  hour  shifts    ThTla«tnfU-wf''^l^^  ^^  *^^  «*^«''  ^"^kmen.  who 

In  these  eight  shifts,  from' t  toto  btgsVo'r  tll^^tef  w'Lic^  7  "r'^T- 

ity,  produce  from  9  to  10  fodders  of  lead  At  JhL  ^^^  J^^^^i  ^'^^n  «f  S^^^^  qual- 
hours,  the  furnace  is  kindled  at  4  o'clock  in  tl  ^1"- '"'""  J^^""^  *1^«  ^^'^^  ^^  1*  or  15 
evening,  each  day,  six  days  in  the  wee^  t-^g  th^^^^  lftT''''*KrK-  '  °^'  '"  **^« 
smelted,  and  two  men  at  one  hearth  in  the  elrW  *«!     r    '  ?  *""  ^f  ^'"8^'  ""^  ""'^  *™ 


SMELTING. 


655 


^ii^T"^!-^^'  '^  P""?^^  •'  'P.  «*>°»e  cases  the  quantity  of  ores  melted  in  one  hearth,  ia  a 
week,  by  four  men,  is  40  bings;  but  a  fair  rate  of  forking  is  from  30  to  35  bings  per 

^J^t  '^•'Jw^K*^  °^  ^^^  required  to  smelt  a  fodder  of  lead,  as  has  been  already  stated. 

ter  b^i;^^   nt  T'^l^  "^  h  ''':    ^*^""  t^-  ^^"^^  i^  «f  °^«d«rat«  goodness,  8  Winches: 
ter  bushels,  or  6  cwt.  avoirdupois,  are  sufficient  to  smelt  18  or  20  bings:  but  when  the 

Tto  lVw?nfhp7tp  I'  \T'''/  ''r''i  ''  ''"^  considerably  greater.  ^In  general,  from 
W  shifts  19  1       ^u    ^^/''^^  «••  fr«°»  ?  to  9  cwt.,  are  consumed  during  four  ^melt- 

{o^stdder^    fl^ri'^'^'  ^°^'.^  ^^f  ^"^?^^'^  ^^  ^^^^  "^^^^^  d»^""g  this  tim°e  is  from  4^ 
to  5  fodders,  the  coal  consumed  is  after  the  rate  of  from  U  to  2  cwt  per  fodder     The 
quantity  of  peats  used  in  the  same  time  is  about  four  small  cart  Gs,  being  som^^^ 
fchl^"  ^  eart  load  per  fodder  of  lead.    The  lime  expended  is  aboit  12Vrchestef 
bushels,  or  something  below  3  bushels  per  fodder  of  lead.  mcnesier 

otoTeteZhliil^^'"^  ^'"^K-^T?.^  slags  picked  out  of  the  brouze  during  the  process 
?;  ?;^P^^^^  smelting  are  subjected  to  another  operation,  in  what  is  caUed  a  slag  hearth 
It  18  simply  a  square  furnace,  open  towards  the  bottom  of  the  front  side.  Its  d^ensfons 
are  various,  but  a  common  size  is  26  inches  from  back  to  front,  22  inches  broad  and  sl 
nches  deep,  inside  measure.  The  blast  enters  through  the  back  wTaW  12  or  it 
mches  from  the  top,  and  below  this,  as  the  heat  is  incoSiderable.  the  sides  o^^he^urn^ 
SLrts  nf  ^  T'^'.f  "^^  "'^'^  (at.working  smelting-houses  old  bearers,  or  other  w^ 
&tensP   fhp     r^^''  f '  econonucally  used),  but  above  the  blast,  where  the  heat  S 

Plate  2  inchP«  fhJ.r  ^?'°''/  f  '^\^  .^^1  '^^'^'^'''^  ^'^'''>''^  ^'  ^••^^"^k.  A  cast-ircJS 
A  (Lst  iron  ^L  .  ^  Pr'^i  *t  a  sbght  slope  outwards,  forms  the  bottom  of  the  hearth. 
thZh  5   ;  ^  P^-^"^'^'  ^''"°'  '"  P^^^^'*  «PP««i^«  to  the  opening  in  front,  one  lip  of 

Jhich  ,s  made  to  project  inwards  towards  the  furnace,  and  to  extend  a  little  befo^the 

trSn  rpt°^  "^  '^'  ?T'-;  J^''  P""  '«  ^'^'^^^  ^'th  two  compartmen  s!by  an  iron 
partition,  reaching  nearly  to  its  bottom,  and  is  kept  hot  by  a  small  fire  underneath    Below 
the  front  of  this  pan,  a  square  pit,  6  or  8  feet  long,  and  4  or  6  feet  broad  and  deep  is  duff 
P  pes  to  convey  water  are  lafd  to  this  pit,  by  which  it  can  be  kept  constaDtfy^^^^^ 
Within  a  few  inches  of  the  top,  when  the  hearth  is  at  work.  ^ 

follows  :-^  "'""^  ^*  *^^  '^*^  ^'^''^  ^'  "^^'^  ^°^  ^^^  '"^thod  of  working  it  is  as 

♦I,  J^^u^'"^u-  u'^'iu  °\*i^  t^®  ''■°"  P^'^'  *"^  the  whole  space  of  the  hearth  below  the  orifice 
itepH?*'''^?'  ^}^'  ^"'"^^'  ''  fi"^^  ^^th  cincfers  of  a  moderate  sizi,  genemlly 
obtained  from  below  the  grate  of  an  adjacent  reverberatory  furnace.  Upon  the  top  of 
whlTf  r  '"^  «PP««'te  to  the  nozzle-'of  the  bellows,  a  kYndled  peat  is  K  and^hl 
supplied  l^thT£f' L^v  °^  '?'  ^"'^>  ^"^^  ^''^  P^^*  ^"d  ««i  ^^"<=h  is  continually 

du^A  ania  ho5v  of  f '^1?/  '^^^  fJ^'  ^^  ^'^'  ^«"^^'  ""^11  an  intense  heat  is  pro^ 
duced,  and  a  body  of  fuel  obtained,  filling  the  upper  part  of  the  hearth  Some  of  the 
g-ey  slags  from  the  smelting  hearth,  untroken,  Tpik'ed  out  of  the  brouze  are  now 
i^inr^  T  J'^'  «r  rather  round  the  edges  of  the  fire,  which  fuses  them  rar^dW^nto 
a  hquid  glass  and  any  lead  they  contain  is  set  at  liberty ;  the  blast  at  the  sSne  time 
h?ih^  t/1"'5  -»7  P.-'-tieles  of  ore  which  may  have  escaped  the  action  Tthe  ore 
Sprf  i«.  H  •  tu^^^''^  '^'  ™"^'"^  ^^^'«  ^th  sink  down  through  the  porous  maL  of  c^! 
tZ  ^r  f  -r  ""^r  P^^'  ^^  V^^  *^^*'th;  the  lead  descending  more  rapidly  l^th  on 
account  of  its  greater  tenuity  and  superior  specific  gravity,  very  soon  collect  below  the 
cinders,  m  the  metal  pan  placed  to  receive  itfand  filtering^\hrougMsTSed  without 
much  impurity,  out  of  which  it  is  cast  into  pigs.     The  thick  fluid  XHrrfllpJ  WaS 

a  5ftu:'do;sTo  iktxf  rt  '^"^'^:,  i  '^^'^-r^'  ^-^nX^^^^ 

a  uttie  does  not  sink  further,  but  is  made  to  issue  through  a  small  taphole   and  flow 

stream  '  By'riliS^:hire  ti^'^'t'  ""^^  ''^^  ^^^  P^*  ^^'^^  ^^^  ^^^^^  "°tinu^ 
ol.on  %  i?  ^""®  ,*t  »"to  cold  water,  the  black  slag  is  granulated  and.  aa 
small  particles  of  lead  may  be  carried  over  with  it,  through  inattention  on  the  Srt  o7 
mmrw'"^°>;  •'  *'^,?^'-^»««'  the  granulated  slags  ar^  carefdly  washed  at  most  s^eltinl 

earthy  matter  contained  m  the  ore  and  coal,  which  the  metalUc^oxides  Tnvert  bto  a 

In  workinjaslag  hearth,  the  workman's  attention  is  principally  required  to  .upply 
gray  slag  an  J  fuel  as  it  is  melted  down  and  consumed,  to  keep  the  Lzz^e  of  the  iSlows 
clear,  and  to  guard  agamst  the  metallic  lead  running  'along  wVthe  sl^  Tnto  the  pit Tf 

«  K^r^rTlt'lT"  ffl^  r°»Pj«yed  to  work  a  slag  hearth,  but,  at  some  mills,  a  man  and 
Jt^J«  V  t  «"^''«"*'  the  attention  of  one  is  wholly  given  to  the  fir;  while  the 
other  supplies  coke  and  gray  slag.    The  length  of  a  shift  is'  14  or  16  hours,  during  which 


' 


Ill 


656 


SMELTING. 


8lag  lead  made  in  smelting.  alWbL  conceived    i^^  ^  v.'^"^'     ^^  q"»ntity?f 

refractory  than  in  rich  anlfree-mn^ninl  orel  hJ'  t  '^f^^^'^Wv  greater  in  poor  and 
thirteentii  of  the  lead  yielded  at  theTe^Itinff  hearth  so  S  ^,/*"'i  .^""^"^  ^*  «°«- 
transactions.  13  twelve-stone  pigs  of  commof  lead  and  1  rJ  j!  '',  "'?^  ^  f  ^"''«°' '"  W« 
.  i^.«r^A  JEnds  and  Smelter  sl^e.l-^Z  oner'at^on  of  Ir^^-  ^'^'''  *^*'^"  ^°^^^^- 
it  happens  that  particles  of  unreduced  and  «!mF!I3  L  smelting,  as  already  described, 
the  fe^rth,  partly  by  the  W  o't'SLrb^^^^^^^^^ 
ore  on  the  application  of  heat    Thi«,  ^ITL  ^-   P""*^!P~^y  ^7  t«e  decrepitation  of  the 

made  use  of  m^meltingauS  which  arTd^^^^^^^^  ^r'''''.  \^  ^^^  ^"^^  «"d  ^^^^ 

and  are  called  hearth-^ds.  It  -^cusiZlrfrre^^^^^  ,1  }^f  '"^'''^^^  ^'^^'^ 

and  deposit  them  in  a  convenient  place  Si  the  Tnd  of  the  vilr  1,  ^  ^'"'"V"'^^  ^«  ^'"^"^ 
when  they  are  washed  to  get  rid  of  the  ear  hv  m^fl  !k1  ^  '  .^""^  '^"'■^^^'^  P«"H 
portion  is  roasted  at  a  strong  heat  untini  hL^- .  they  may  contain,  and  the  metaffic 
Afterwards  smelted  in  th^ofeheaVtrexa^^  ^°^  ""^^^^  ^"*«  ^""^P«.  and 

operation,  for  the  first  time  already  des^S  '"^  ""^^  ^'  ^""^  undergoing  that 

giv^n\1fntUy  oro*^%ttrL\^°1:iyi^^^^^^^^^  T^^^  ^J  t^e  smelting  of  a 

biBgs.  on  being  roasted  and  reduLdTthe  orp  hp«r^^^^^  produced  in  smelting  9^51 

and  the  gray  stags  separated  L  th"  p  ^t  ^ve  by  tr^Sme^^^^^^ 

of  slag  lead ;  making  the  total  quantitv  of  lead  '^fi9  Zi^^^  I-  *  !  '!^  ^'^^'"*^'  ^^  ""^^ 
qrs.  23  lbs.  from  the  smelting  oriJSbfngs  o^^^^^^^      ^^"  ^^''^  "  ^^  *^"  '^^^  «^  ^  cwt  3 

frollhl'rLtTfltfo'r^^^^^^^^^  ^\"'^^::  ^^•^  «°^«^«  -°d  metallic  vapours, 

of  some  time,  a  fo'^ourd^"^^^^^^^^^  ""'^^T'^^'^  ^^"^^'^'  ^^  *^^-^ 

and.  probably,  also  of  sulpKate  of  ead  whi.h  L^f  k  'i  ^"  v  ^  ?''"'''*^  °^  sulphuret. 

cesses,  mixed,  like  hearth-ends  with  a  n^kv  nf  ^f""  ^°^f Jihzed  in  the  diflFerelit  pro! 
used  in  smelting.  It  is  eenerX  sufferS^^  ^  ^  earthy  njatter,  from  the  Ume  and  coal 
until  the  end  of^  he  yea?Xn^t7s  wSLeS  ^""^^^^^^"ther  in  or  out  of  the  chimneys^ 
residue  is  roasted  unti?  H^heres  Tnt^lumns  «nT^^^  u^a  ^^'^J^  T^^''^  ^"^  ^^^  ^^^^7 
the  same  way  as  gray  slags    t£  quint  tvo^fLl^^ln  '"  ?f  '^^  ^'""'^^  ^^^"y  ii 

deposited  in  Wltin|975Vbi^8  of  ore %^  t^l^f  ^w  "''^.  [T  '^'  '"^'^''''^  ^""^^ 
14  lbs.  of  lead  per  100  bings  of  or^        '  ^  ^^^  '''*•'  ^^"^  ^*  ^^^  '^^  ^^  5  cwt  0  qrS 

quInUtro^^eXS  :^::^^^^^^^^^^^  ^«  considered  invariable,  for  the 

ends  a/d  smelter's  fume,  from  a  S^e^^f^^Xt^^^^^^^^^  ^^"^  '^^^^  *«  time  by  the  hearth- 

d^p^s  .Oder  c„.ide.tio„  „«  ,U.e.,  to^g^.^LiLt  ^Z%  'L?S  iSIS^' 

Correspmdenet  of  Proiwe  with  Atsav.—As  the  amrftino. .    •    ••  i, 

m.sm^agement.  through  inexperience  ofimuLtil  TThe  laHf  V^™  '  *"  ^*S' 
men,  it  is  a  matter  of  eome  conseouence  to  l-r,^^  K^  ^     .1  ^         ,.   ®  *«''"''  ""■  ^o''k- 
by  smeltiug  in  the  laree  A  cSotdcTs  with  Z„  .^  f  !    ^  '^'^^^'^^  "^  '""•  °'*»i°«J 
o|^ra^d  uV,  and/r  thia'puTpS^Tu ra'.^*ro'^^^ro°hl^ve~rtl^ 
sampled  and  aesajed  prior  to  smelting.    The  pureet  ^lena?a  a  eom7o™d?f       ""'''' 


1  atom  lead, 

1  atom  sulphur,  - 


13 
2 

15 


86-66 
13-33 

99-99 


Wr^e^tTfir^slTr  Sr^'r'l-n^'Tl^iT a"^  T^''^^"  *"  '^  ^^r- 
piece  of  cubical  galena,  by  treatLent^th  bi™^  Id  ,»h  ^  ^,i^r^  "■""  »  ""^  P»" 
awayer.  In  the  large  4y  leaTore  if  seE^l  In  '  '-1  ""^ ''""''  "^  *"  «peflenced 
yield  more  lead  to  the  assay  tton  77  or  78  ner  cenr  n  "^  P"T'  "'"'  '''"^'  ■""  "f*" 
of  lead,  contains,  besides,  protebly,  4  oje'^^r  «„t  ^L^^^^^-^  ^J'"  "  P*"-  ««■"■ 
before  reduction  in  the  prOTesa  of  a,«vlna.TrL.-;f  "oxidized,  or  volatilized, 
is  only  made  to  its  absofute  p^oSnceX  ^y  no  ,S^  d"L''''  "^^'^'a  f  V'""P'<''  '"^""'"^ 
tity  of  lead  it  may  contain  ll^jond  IhT^ST/p^duT       ^"^  P'"* '°  ""  f°'"'"«  I"*"" 

asiXrs^i^^Jrtli'e'ltii^aS^ru*^  l-flj  "^  "l""  '"'"-'^'^  "^  the 

allowance  is  to  deduct  6  parrffoKe^ro^S^rV?^  ""^  "?"'•  ^  «-"t<'«'"y 
alent  to  making  an  allowaniTl  cwtT^Kr  ."""?  P"',' "^  ^ V''''='' "  ^q"'''- 
-lowance  of  /or  3  per  cent..  orUrT^  ll^^'e/^rSIstt  lrfor"mSU''S.hS 


SMELTING. 


657 


•r«i,  when  weighed  over  at  the  mine,  as  the  sample  assayed  is,  in  all  cases,  perfectly  dry 
It  is  found,  in  practice,  in  almost  every  case  where  a  large  quantity  of  well-dressed  ore 
is  skilfully  and  carefully  smelted,  that  the  allowance  of  5  parts  of  lead  from  the  assay,  or 

1  cwt  of  lead  for  every  ton  of  ore,  is  rather  more  than  sufficient  to  cover  the  loss  in  the 
smelting  process,  without  taking  into  account  the  lead  obtained  from  the  hearths  end« 
and  smelter's  fume 

Refining  of  Lead. — The  quantity  of  silver  contained  in  the  greater  part  of  the  lead 
raised  in  the  northern  mining  district  is  sufficient  to  render  its  extraction  profitable,  and 
it  is  of  the  greatest  importance  that  the  process  of  refining  should  be  performed  in  the 
most  perfect  and  economical  manner,  in  consequence  of  the  enormous  quantity  of  lead 
continually  submitted  to  this  operation.  It  is  well  known  that  the  separation  of  lead 
and  silver  is  eifected  through  the  difference  of  oxidability  between  these  two  metals,  silver 
remaining  unaltered  when  exposed  to  the  air  ot  the  atmosphere  at  a  high  temperature, 
and  lead,  wider  the  same  circumstances,  becoming  rapidly  converted  into  the  state  of  a 
protoxide ;  which,  when  formed  in  the  large  way,  is  called  litharge.  The  refining  pro- 
cess is  therefore  performed  by  exposing  the  lead  containing  silver  to  a  strong  btast  of 
air,  at  a  high  temperature,  in  a  furnace  properly  constructed  to  allow  the  iftharge  to 
separate  as  it  is  formed,  and  to  admit  of  the  continual  introduction  of  lead  as  the 
operation  proceeds,  and  the  ready  removal  of  the  cake  of  silver  obtained  at  the  end  of 
the  process. 

The  furnace  for  this  purpose  is  called  a  refining-fumace.  It  is  a  small  reverberatory 
furnace,  the  fire  place  of  which  is  very  large  compared  to  the  size  of  its  body,  rendering 
it  capable  of  exciting  an  intense  heat  Some  of  the  objects  to  be  attained  in  the  con. 
struction  of  this  furnace  already  stated,  render  it  necessary  that  its  bottom  should  be 
moveable,  in  consequence  of  which  an  open  space  is  left  quite  through  under  the  body 
of  the  furnace,  from  back  to  front,  which  is  formed  by  two  walls  of  brickwork.  The 
distance  of  these  walls  in  front  is  36  inches ;  but  they  approach  together  at  the  back  of 
the  furnace,  and  the  space  between  them  is  but  28  inches,  which,  to  prevent  a  draught 
of  cold  air  underneath  the  furnace  bottom,  is  closed  with  iron  doors.  At  the  height  of  16 
or  17  inches  from  the  floor  two  strong  iron  bars  are  laid  across  between  these  walls  and 
firmly  secured  in  the  brickwork  at  each  end.  Above  these  bars,  and  at  the  height  of  27 
inches  from  the  floor,  a  plate  of  cast-iron,  having  an  elliptical  opening  in  the  middle,  the 
transverse  and  conjugate  diameters  of  which  are  46  and  28  inches  respectively,  is  laid 
across,  from  wall  to  wall.  Instead  of  a  square  plate,  a  broad  elliptical  ring,  supported 
by  bearers,  is  sometimes  used;  but,  in  either  case,  the  brickwork  forming  the  body  of  the 
furnace,  is  built  upon  this  plate,  and  is  made  to  extend  to,  and  surround,  the  edge  of  the 
elliptical  opening;  except  a  small  aperture  in  front,  6  inches  wide  by  9  inches  high.  The 
two  flues  communicate  with  the  chimney,  and  in  other  respects,  except  those  to  be  after* 
wards  noticed,  the  furnace  is  finished  in  the  usual  manner. 

The  bed  or  bottom  of  the  furnace,  when  in  operation,  is  formed  by  a  shallow  elliptical 
vessel,  called  a  test  or  test-bottotn,  the  construction  of  which  merits  particular  attention, 
as  it  is  an  important  part  of  the  refining  apparatus.     An  elliptical  iron  ring,  4  feet  long 

2  feet  6  inches  broad,  and  4  inches  deep,  outside  measure.  The  thickness  of  the  iron  ii 
1^  of  an  inch,  and  across  the  bottom  of  the  ring  are  five  bars,  each  8^  or  4  inches  broad, 
and  i  an  inch  thick,  firmly  rivetted  into  the  ring,  with  the  under  surface  of  each  level 
with  its  lower  edge.  The  ring  is  filled  with  a  mixture  of  one  part  by  measure  of  fern 
ashes,  and  ten  parts  of  ground  bone  ashes,  well  incorporated  and  moistened  with  a  little 
water,  until  a  small  quantity,  when  compressed  in  the  hand,  is  found  to  cohere  slightly 
together.  In  filling  the  test  ring,  it  is  placed  upon  a  level  floor,  and  this  composition 
strongly  beat  into  it,  with  an  iron  rammer  5  or  6  lbs.  weight  (similar  to  those  used  by 
founders  for  compressing  sand  into  moulds),  until  it  is  quite  full,  and  the  surface  of  the 
mixture  perfectly  level  with  the  upper  edge  of  the  rin^.  A  sharp  spade  is  then  taken, 
with  which  a  part  of  the  composition  is  removed,  so  as  to  form  the  test  into  a  flat  dish. 
The  bottom  of  this  dish  is  about  If  inch  thick  between  the  bars,  and  the  breast  of  the 
test  is  5  inches  thick,  the  remainder  of  the  circumference  being  2  inches  thick,  and 
sloping  inwards  to  increase  its  strength.  Across  the  breast  of  the  test,  a  furrow  or  small 
channel,  called  a  gateway,  is  cut  diagonally,  1  inch  wide,  and  |  of  an  inch  deep,  as  a 
passage  for  the  litharge ;  and  it  is  made  near  one  side  of  the  breast,  in  order  that  a  simiUr 
passage  may  be  cut  on  the  other  side,  after  the  test  has  been  some  time  in  operation,  and 
the  first  gateway  has  become  worn  down  by  the  stream  of  litharge.  A  space  1^  inch 
wide,  and  7  or  8  inches  long,  is  cut  out  between  the  front  of  the  breast  and  the  test  ring, 
in  order  that  the  litharge  may  flow  down  from  the  test,  without  coming  in  contact  wiS 
the  iron. 

Instead  of  bone  and  fern  ashes,  mixed  together  in  the  proportion  stated,  it  is  a  better 
practice,  and  one  gradually  coming  into  general  use,  to  make  the  tests  of  a  mixture  of 
one  part  of  the  best  American  pearl  ashes,  to  forty  parts  of  bone  ashes,  by  weight  Tbe 
pearl  ashes,  reduced  to  fine  powder,  and  perfectly  dry,  are  thoroughly  incorporated  wi'k 

24 


rn 


658 


SMELTING. 


Uie  Done  ashes,  and  the  compound  is  then  moistened  to  the  proper  dcCTee  with  wat«r 
after  which  the  test  ring  is  filled  in  the  usual  manner.     FroHTo  F^Tunds  orue^rl 

Tlie  test,  thus  constructed,  is  apDlied   to   the   onpnm>*   ;«    ^v^    •  i  x 

When  the  test  is  properly  fixed  in  this  situation,  and  thorouffhlv  dried  hv  the 
applicatmn  of  a  gentle  Ut,  it  is  ready  for  the  reception  of  lead,  which  s  poured  into  it 
with  aniron  ladle,  through  the  chaimel.  being  previously  melted  mid  kepT  nearly  at  a 

etl     A  mode"  o'fleedt ''"tl  '  r."  -^^  '^^^  ''  '^^"^^^^  *«  «"  ^  "^^  ^-^  to  t^e  wo^rk  „^ 
a  P^  of  lead  or  1  it„  3  K?  J^''  ''  f  "betimes  practised,  which  consists  in  suspending 
t^Jlu      ■       ^/.^  V°°  Y^'^}"^'  ^^"""^  *  ^^"^  »^^e  the  melting  pot,  by  means  of  a  chain 
and  a  owing  ,t  to  dip  into  the  melted  lead  when  made  to  dfsSnd,  lo  ^^o  W^  ?S 

ead  displaced  by  its  introduction  directly  into  the  test  through  the  4an^el  wL^hi^ 
that  case  must  be  a  little  lower  than  the  lid  of  the  melting  pot  Some  ^fin  n/furnaces 
a  e  not  constructed  with  the  channel;  but,  instead  of  it,^hayinc.  an  openL  [nX 
buck- work  of  the  furnace,  on  each  side  of  the  test,  through  one  of  whtch  aChol!  nl^? 
kad  IS  introduced  and  gradually  melted  down  into  the  test  by  the  heat  of  the^L 
^S^slTe  of  i;r*;'V"'  ^-«^.^r«  *»  t^^^.  -  the  lead  is  consLed.  An  op^ Jnf^n 
fnTrod^  cpd  nn^^  J  "  considered  necessary,  in  order  that  the  lead  may  he  always 
!.nL^?if  '^°.*v^"'^^  ''PP?!*^  *^  *^^  gateway  working  at  the  time  to  prevent  the 

Ent  ^t: te  a^d"!n"om'  '  ^^'^  ^*TT'  f '"^^  ^^^  '"^^  breaTt  ofXtest  n t 
^uant  vnflln'^^  'fi  A^^  instances,  to  be  afterwards  mentioned,  where  so  large  a 
2.oT-  ^  ?  A^^^^  P^°^^  *"  *  *^^*'  ^  *«  '■^n^Jer  it  necessary  to  have  three  ffatewavs  the 
L  at  wort  "''^  '''"^'^  '°  "P^""^  ^^""^'  ^"""S  *^^  *^^«  that  tie  mifSirga^eway 
The  last  part  of  the  refining  furnace  to  be  noticed  is  the  aperture  behind   for  the 

maXneTv      tSi^^'^T   '•    f   Tf^^^^   ^^'  ^   P*>"«^^"1  ^oub^e  l^Uows,  worked  by 
machinery.    This  aperture  is  formed  by  a  conical  iron  tube  called  a  muzzle  walled  into 

ll  1  "fr'Lfr"''"^  '^"  ^^^  "^  '^'  ^"'^^^«'  its  larger  end  our^rt^eS  es The 

of  the  It  is^nTl'  "'^  ;^^^,T'"'^'"^  P^^J^''"»  ^^^^  ^^«  fumace,ove  the  inner  ed.e 
A  J  r  'uf  bent  down  slightly,  and  its  orifice  compressed  into  an  oval  form  so  m  tn 
deliver  the  blast  with  sufficient  force  upon  the  surface  of  the  lead  and  at  the  same Tin^ 
to  spread  It  out  towards  the  sides  of  thftest.  Much  care  is  usSSly^rtowed  upon  the 
construction  of  the  muzzle  as  the  proper  direction  and  distribution  of  ^e  blast  i/a  po\nt 
of  great  consequence  to  the  working  of  the  furnace  *         ^ 

Refining  furnaces  are  generally  built  double,  that  is  one  on  each  side  of  the  upright 
tTZV  ^j;*'  ^^.^^P^'"^^"  t»^«  d'r<^tion  of  the  draught,  and  consequent  sLLfffhe 
fire-places,  there  is  no  difference  whatever  between  them.  The  fume\nd  smoke  from  b^th 

from Th?^'^  r*" ? ^^^'''"^  "^ ^}' ^^^'•^^^"^^ fl"^' «^P^^te from  that  con^g theTmoke 
fo  mil  He?/  h  ^  ^r^"":  T  ^'^'*^'  ^^  '^^  ^''^^^^  ^i*^  ^^i^^h  they  are  n^ot  suffered  • 
oxide  of  Tead.      ^    ^^'    ^    ^^''^  ^'^^  P^^^"''  "^^^"^  '"^""^'^  ^"'"^'  ^^<^»^ "  principally 

.Jo*f!  *5^t  j)emg  properly  placed  in  its  situation,  cautiously  dried,  and  filled  with  lead 
as  already  detai  ed,  is  exposed  with  its  contents  to  the  flame  passUig  over  ^  ^til  tS« 
lead  attains  a  bright  red  fcat,  at  which  period  the  blast  of  air  ifm^e  to  plLv^pon^t^ 
rnronp/J'r  oxygen  thus  supplied  rapfdly  produces  a  stratum  STuid  li&eThich 
18  propelled  forwards  by  the  tlast.  and  forced  through  the  gateway,  over  tKre^t  of 
tream' '  C  fc^"^  supplied  by  a  fresh  quan^tity.  so\s  to  ^e^rup  a  conUnuaf 
time  W  thVt  I  ^  •  ^';?''^*f«  »"*°  1"°^P«  ^  »t  falls,  which  are  removecf  from  time  to 
of  ll^T  !  1  workmen  in  attendance,  who  take  care,  by  the  addition  of  fresh  quaiTitie^ 
of  lead,  to  keep  Its  surface  in  the  test  always  at  the  proper  working  level  UZwa^ 
the  operation  proceeds ;  but  as  the  hot  litharge  gradualirwears  down  tC^atewlv  Jt^ 

t  ^Tuf  '?'  ':''  r^P"^^^  '^  ^«^^'°S  *  «"ffi<^'«"t  quantity  of  eaH  b^^omes  ne^;rar^ 
to  make  a  fresh  gateway,  generally  after  two  fodders  of  lead  have  been  refined  wS 
^js  IS  done,  the  blast  is  suspended^  the  old  gateway  is  topped  up^^th  a  p^t  of^ne 
ashes,  a  fresh  channel  made  on  the  other  side  of  the  breast  and  the  test  fiutr?  ,?«  w^?K 

mnre'%'l '  T^'  K^'^'  "^?  ^"^^     ^^'  ^'^'^  then  proce^^agLIn,  un^ 
more  of  lead  have  been  oxidised,  when  the  second  gateway  being  also  worn  down    „ntfl 
the  test  does  not  contain  more  than  one  cwt.  of  lefd.  the  Wge^s  T^po^n^  ^b^^^^^^^ 
are  slackened,  and  those  in  front  taken  away,  and  the  fluid  Wrcalfe^^lSi^Uv  rich 

four'  whLT'^  Th°  "\T  r'  '^  ^"^^^^  ^»  ^i^«^«^'  r-"i4'  upo;\'':LX^e^;^S 
four  wheels.       This  rich  leaJ,  containing   the    silver  of  four  fodders  of  oriS  T^«A 
(usually  from  30  to  4o  ozs.)  is  cast  into  a  pig  and  taken  awa^ :  a  fresh  test  is  aT^^ 
the  furnace,  and  4  fodders  of  lead  worke/in  it,  in  the  manner  described! VntiW or  lo 


SMELTING. 


659 


pieces  of  rich  lead  are  obtained.    A  test  is  then  made,  the  bottom  of  which  is  somewhat 
concave,  instead  of  being  flat  like  those  already  mentioned,  and  in  this  the  rich  lead  is 
carefully  refined,  yi;eWin^.  at  the  end  of  the  proce8^  a  cake  of  silver  weighing  from  1200 
to  1800  ounces.    IJe  rich  lead  is  treated  in  the  same  way  as  ordinary  fcad,  except 
perhaps  more  carefully,  and  after  the  last  piece  is  introduced,  the  gatewayis  made 
deeper  with  an  iron  tool,  from  time  to  time,  as  the  surface  of  the  lead  subsides  by  its 
gradual  conversion  mto  litharge ;  and,  from  this   period  untU  the  cake  of  silver  is 
rendered  pure  aU  the  itharge  then  flowing  is  kept  separate,  as  it  ia  apt  to  carry  along 
•  with  It  a  portion  of  silver.    The  part  received  is  caUed  rich  litharge,  and  may  contain 
on  an  average  20  oz.  of  silver  per  ton  ;  it  is  generally  worked  up  at  the  end  of  the  year 
by  being  reduced  into  lead  and  again  refined.     As  the  cake  of  silver  becomes  nearly 
pure,  It  is  most  essential  to  keep  it  constantly  in  fusion,  for  if  ooce  suffered  to  solidify 
It  18  very  difficult  to  excite  a  sufficient  heat  to  melt  it  again.    The  fire  is  therefore 
urged  with  great  violence,  untU  at  length  the  whole  of  the  lead  being  oxidized   the 
formation  of  litharge  ceases,  and  the  mass  of  melted  silver  appears  pure  and  beautifuUy 
resplendent     At  this  stage,  it  sometimes  happens  that  drops  of  melted  slag  from  the 
rurnace  roof  fall  down  upon  the  fluid  silver,  in  which  case  they  are  carefuUybrouffht  to 
the  edge  of  the  melted  metal,  and  raked  off  upon  the  naked  part  of  the  test     The  blast 
from  the  bellows  is  now  stopped,  the  fire  is  slacked,  and  the  silver  suffered  to  cool  • 
winch  it  does,  very  gradually,  first  at  the  surface,  forming  a  solid  crust  over,  a  portion 
remammg  fluid  below.     When  the  temperature  has  fallen  sufficiently,  this  also  becomes 
8oad,  and  in  the  act  of  doing  so.  a  large  quantity  of  nearly  pure  oxygen  gas  is  expelled 
irom  It,  and  at  the  same  instant  its  particles  expand  considerably,  so  as  to  break  the 
crust  already  formed,  and  force  out  a  portion  of  silver,  to  the  height  of  3  or  4  inches 
above  the  rest  of  the  cake.     Occasionally  particles  of  melted  silver  are  projected  out  of 
this  mass,  to  a  distance  over  the  naked  part  of  the  test,  and  the  sides  of  the  furnace,  by 
wl^ch  a  loss   of  the   precious   metal   is   sometimes  sustained.     After   having    cooled 
sufficiently,  the  cake  of  silver  is  removed  from  the  furnace  along  with  the  test   from 
Which  It  IS  then  separated  without  difficulty  ;  and  if  any  slag  or  portions  of  the  test  are 
lound  to  adhere  to  it,  they  are  cleaned  off,  and  it  is  ready  for  sale. 

During  the  working  of  each  test  it  gradually  absorbs  litharge  until  saturated  and  the 
portion  thus  combined  is  sufficient  to  pay  the  cost  of  extraction.  For  this  purpose  the 
o  d  tests  are  broken  to  pieces,  and  smelted  in  the  slag  hearth,  mixed  with  a  portion  of 
black  slag,  m  order  to  render  the  bone  ashes  more  fusible ;  the  black  slag  used  beinff 
run  into  lumps  for  the  purpose,  and  not  granulated  in  the  ordinary  way.  The  produce 
of  this  fusion  IB  a  description  of  lead  called  test-bottom  lead,  which  is  very  hard  and  of 
mferior  quality.  j       ^      » »i 

The  deposit  called  refiner's  fume  is  removed  from  the  horiiontal  flues  from  time  to 
time,  and  is  frequently  ground  up  with  oil,  forming  a  very  cheap  and  durable  paint 
but  the  quantity  produced  is  generally  too  considerable  to  admit  of  the  whole  being 
disposed  of  in  this  way,  and  the  surplus  is  reduced  by  being  roasted  almost  to  fusion 
and  then  worked  in  the  slag  hearth,  in  the  same  manner  as  gray  slags  As  mieht  be 
expected,  the  lead  obtained  from  the  test  bottoms  and  refiner's  fume  contains  but  a  verv 
email  portion  of  silver.  ^ 

Instead  of  converting  into  litharge  but  4  fodders  of  lead  in  each  test,  as  already 
mentioned,  some  refiners  are  in  the  habit  of  working  12  or  13;  but,  in  this  case  the 
tests  are  constructed  with  peculiar  care,  and  the  bottom,  sides,  and  breasts  are  liiade 
thicker  than  usual.  The  litharge  from  4  fodders  of  lead  flows  through  the  first  gate- 
way made  on  one  side  of  the  breast,  and  when  the  quantity  of  lead  in  the  test  is 
reduced  to  about  a  cwt,  it  is  cast  into  a  rich  pig ;  4  fodders  of  lead  are  then  worked 
through  another  gateway,  on  the  opposite  side  of  the  breast,  yielding  a  pig  of  rich  lead 
m  the  same  manner  ;  and,  for  the  remaining  4  fodders,  a  gateway  is  made  across  the 
°J!  u  j't  the  breast  By  adopting  this  method  of  working,  the  loss  from  the  lead 
absorbed  by  the  test  bottoms  is  considerably  lessened,  and  a  great  saving  is  made  in  the 
expense  of  tests ;  but  the  process  is  rendered  slower,  as  it  is  necessary  to  work  at  a  low 
degree  of  heat.  The  saving  in  tests  is  not  what  it  appears  to  be  at  first  sight ;  for  those 
made  to  refine  the  larger  quantity  of  lead,  being  thicker  and  stronger  than  the  others, 
reauire  a  larger  quantity  of  bone  ashes.  vjuuco, 

I  A  "^^^'A-^  '^^^"'"^  ''*'^''*?  *  ""^^'  ^^^"^  *^®  «^"8e  just  stated.  When  4  fodders  of 
lead  are  oxidized  in  a  test,  it  is  usual  to  accomplish  this  in  from  16  to  18  hours  ;  and  6  tests, 
or  24  fodders  of  lead,  can  be  very  easily  converted  into  litharge,  in  one  furnace,  by  3 
men  in  a  week.  The  quantity  of  coal  consumed  is  about  4  Winchester  bushels,  or  3 
cwt  avoirdupois,  per  fodder  of  lead.  In  cases  where  12  or  13  fodders  of  lead  are  refined 
in  a  test,  it  is  customary  to  work  but  one  test  in  a  week,  in  one  furnace,  which  is  only 

Sf^:  n.^"j?*''y  ®.*?^®1  ^^^®  ■'  ^"'  ^^^^  *^«0'  t^'^ee  men  by  managing  2  furnaces  refine 
24  to  26  fodders  of  lead  per  week. 

Reducing  of  Litharge.— The  reduction  of  litharge  into  lead  ia  an  easy  process  and  in 


660 


SMELTING. 


being  flat,  is  niade  to^lope  towards  an^  o^nTng  Tn  SL  thVc^^^^^^^^^^^^  r'ff  ^i 

18  conveved,  bj  means  of  a  cast-iron  channel  into  a  not  fn  Ko  f   Ti  5^  reduced  lead 

sale.    The  inside  of  a  roasting  furnace  is Venerallv  ml'dl  ]L  ^k  ^.  ""S?^  ?"*°  P'^«  ^^'• 
feet  long  and  5^  broad,  and  1  furnace  V^rS  ^orLnrtSrL'"'^*^'"!'  ?^"'  ' 
shifts  each,  is  capable  of  reducing,  without  difficilty^  the  iL  n^^-'^^T'  ^\  ^  ^T' 
ing  furnaces,  each  working  six  teste,  or  24  fodders  ^^r' week     After  S^r!^  '  •  ^^^  ''^' 
has  been  properly  heated,  the  Droceas  io  nnmmo!!nli   i!        -^"er  the  reducing  furnace 
stratum  of  coal,  which  taking  fir?^^  sL  form?f  1^^  T'T^.  j^^bottom  with  a 
thicknesa  Upon  this  the  chaLe  of  SffT^ed  „n  wfftf  °^  '^T"^  ^"'?  '""«  '"^^^^  '^ 
is  thrown,  an^  a  furnace  of  the  sizfrneftio^  wm^i,  u^  '"'*"  ^"^^^'^^  «^  ^^sh  coal 
reduction  goes  on  rapidly  and  the  ?^^T^  T"^  ^i^  i^°°^  ^.^^  ^^  three  tons.    The 
litharge,  until  the  quant  [y  adld  L  S  as  wilT^^^^^^    T  '^f  *"  *^'°^'  ^^^^  fresh 
the  charge  is  then  suffere/ to  run  down  wfthThl  ?d^?     %T  V^  ^  /^^^^^  ^^  ^^^d; 
reduction,  as  it  seems  to  ^  reoTred     At  th«  ^A  «?    •  ""^  ''^/'■^?  *^°^^'  *^  P'-^™^*^  the 
litharge  is  reduced,  and  S  thrboln,  of  theTurnac^^^^^^^  '\'  ^^«^«  9^*^^ 

s^,^called  litharge  slag,  which  is  raked  o'ul  'XTs^irh^tT^l^^/r °n"^^ 

is  afterwards  worked  iver  n  the  sSearth  t^th  W^  unavoidably  united  with  it,  it 

bottoms,  yielding  what  ircaUed  ffim?  «w  i     ^    "?•  u^?\ '"  *^^  ^""^  ^^^^  as  the  test- 
ferior  qiiity  an^dlnta  nsSe  Jlv^^^^^^^^  ^'^'  test^bottom  fead.  is  of  in- 

naed  to  mix  with  the  lithLte  in  o^^^^^^  that  th/ ^^  f^^°'^  *^^*  l^^  ^^'^  ^^^^  «^«"^d  be 

-nounted  U,  one  thirtyseeond  part  oHhe  o?§naI  leld  ^fi^ed    "'  ""'^  '"'"'  '"S""""' 

undergoing  the  reYnbL  S^^ts  but'  ?^  i"^°  ^^  ''iK'^  *'  *<"»'  I"""'"?  »'  k»d 
the  helrth%nda  and"  ^U?S^™'e  W  tt  dee?^e  If  w't  ^  ^K^^.  T**  i"?*fi«^  ''''« 
are  worked ;  it  is  therefore  imDoJ  blf  ^rhf^IL      >      '■\'^^'^  *e  refining  furnaces 

^.rrespond  with  experien^  r^^^^/^eTtlfeMUht ^^^  "''°''  ^'"  «-«? 

to  the  profess,  by  tEg  a  Sip  fr^ieJh  „,V  3'"^.?*  'fl  *°  '^  '^^"'^  ?'«"<»>' 
ting  a  known 'weVt  to^cupdfatiT  UtZtZyhL^L'^t^^i^''^"'  »■«'  '"bmit- 
obtained  in  the  large  way  isVater  than  thalSi»t.yr?..  *■""  «''\q"»""'y  of  silver 
is.  that  the  lithargf,  aa  It  sinfettotre  smalt  Pelea,?;^^^^^^  -"T"  '"^'"='' 

•liver,  rendering  the  button  obtained  rather  le„flf.'„?r  T.  f  v  "  ?'°"'*  P""^'""  »' 
the  litharge  ab^rbed  by  the  ^^McupSZlkZ^Z^'^^A'i^.^t;-  *"" ^11"^'"'"^ 
refining  this  lead  a  second  time,  anothS  minute  bu«o?„'fTi*  ''\^\^^^  ^  .bor",  and 
to  the  first  button,  generally  indicX  a  oZ,Htv  „f  .ii  ■  fl  ",  °'''"°H  which  added 
with  which  its  produce  ta^rCTeat  way^rhin^car^^^^^^^^  under  examination, 

taking  into  account  the  sLu  pSriiW  unavoffl?^"*^^'  ""^  ''-T'^  ""'""^es 
and  found  in  all  samples  of  XnedLad  to  tireXt^^f    "f'.r^''  """^  "'«  ^'^^"e"' 
per  fodder.    It  will  easily  be  «n<«ived  that  if  the  , In  ^"K  *"  """'=«  ">  »''  »""<=« 

carefully  performed  at  firsrwl^h"  due  deCT«  of  he^?  Jr'''  "'  <="P«'l»«on  has  been 

theptMteS  ^Llrfh-^uldt'^^ednr^ta-sf^ei'"  ""^rr 

or  1  cwt.  of  lead  for  everv  ton  of  oro   a«^  w«r,u-  V  •      if      ^  °  P**^*^  '^^o"*  the  assay, 

e?err.7.r  ■  ^/-^p"^- o-nr;^a§  teaVtiriry^^i 

firs?,Urc:f  irli"welftrof?eZi.«^^^^^^^^  'l  "T''^  ^»«««"«'J-  '■>  ft" 

fume  is  melted  up.  and  the  fead  extrS  from  the  /  ^.i.T''*''  *''«  deposit  of  refiner's 
ultimate  loss  becSmes  not  more  thS  onelS^Sh  a„d  wiS?  1°""'  »"d  'fthai^e  slag,  th. 

heat  at  which'The  o,idatic„  wiSl  t  '^t^  V:^.  t  tiLVt.^^Tr^^-,  "J 


SMELTING. 


661 


ind^TmW  w!fh\t'f '''''?^  ^i^  i^  ^^^^  the  particles  of  silver  to  separate  from  it. 
and  combme  with  the  remaming  lead  in  the  cupef;  they  are  thus,  as  it  were  entangled 

ll'riaUySir™''''*  ''"'"  '"^  "'-''  "/"'"=''  ""«  P™0-i/slM 

SMKLTING  IRON  FURNACES,  commonly  called  BLAST  FURNACKS     Several 

of  these  furnaces,  a,  mounted  near  Glasgow.^deserve  to  be  made  known   on  SSu 

olttirTem*"'  "'"'""'"»"•  '"*  '«'^'-"^-  of  *'-  fo-.  -d'th"  a^S^u^St 
^^r.  1302  represents  one  of  the  smallest  of  these,  which  measures  from  thp  Un^  of  *».^ 
bottom  to  the  top  48  feet,  from  which  all  the  oth^r  d  meSs  may  b^  estimated  U 
Tm'ZWil  T"''''  I''  '""'^f  into  moulds  and  for  melting?7the  cu^  >V '* 
1803.  and  1304,  represent  a  much  larger  furnace,  being  from  the  top  to  the  liSe  a  b  c  d 


«0  feet  high.  A  few  have  been  built  still  larger.  This  furnace  has  a  double  case,  each 
of  which  consists  of  fire-bricks.  This  case  is  enclosed  by  common  bricks,  and  these  by 
a  wall  of  stone  masonry,  llie  successive  rows  of  bricks  are  laid  stair-wise,  having  the 
aiiijular  retreat  filled  up  with  fire  clay.  Fiff.  1307.  is  a  modern  furnace  of  verylaree 
cumeiisioas,  as  the  numbers  upon  it  show.  ® 


;n  ^  If  I,-  "^P'  ?^"V''^  «f  the  great  iron  works  of  Butterly  and  Codner  Park 
in  Derbyshire,  has  invented  a  very  elegant  and  eflFective  apparatus  for  fSngWs 
^idLlirvHlJrl^/T^  mm.  (cacined  ironstone),  and  limes^tone  Tdue   prSon^ 

?^d  arJ  itu  ^i  130^^^^^^^  T^'  "^  'K  ^"'•"^-  ^^*-  1308.  09.  rep^res^  this 
feed-apparatus,    /^t^r.  1308.  shows  at  a  an  outline  of  the  furnace,  and  at  b,  the  line  of 

barrnl"  n  ^  n  ^^  "' ''  '^'  ^^«^,°^«<^hanism.  It  coDsists  of'a  loug  bilance  lever 
a^  2rfe«t  in'hpia^r?n  ^  ":°".^^yl^°d«»-'  «pen  at  top  and  bottom.  4  feet  in  diameter 
»nd  2i  feet  m  height,  m  the  mside  of  which  a  hoUow  cone  of  iron  is  suspended,  with 


662 


SMELTING. 


It 


^;m 


l!      I 


SMOKE  PREVENTION. 


663 


never,  d,  e.  is  seen  m  profile  or  vertical  section;  a,  is  the  fulcrum  wheel,  upon  which 
the  lever  is  m  equihbno  when  9  cwt.  of  coals  are  put  into  the  cylinder;  thena  weight 
IS  hung  on,  near  the  end,  e,  of  the  lever,  as  an  equipoise  either  to  9  or  12  cwt.  of  mme 
according  to  circumstances;  and  next  a  weight  to  balance  one-third  of  that  weight  of 
limestone.  These  weights  of  materials  being  introduced  into  the  cylinder,  while  the 
barrow  rests  upon  a  level  with  the  line  e  d,  it  is  then  rolled  forward  into  its  place 
as  shown  in  the  figure  upon  the  wheels,  b  6,  upon  a  platform  sustained  on  the  top  of  an 
inverted  cylinder  within  the  cast-iron  column,  into  which  cylinder  air  is  admitted 
(through  a  valve  opened  by  the  workman)  from  the  furnace  blast,  the  air  passincr  up  the 
tube  seen  m  the  axis  of  f.  The  inverted  air-cylinder  is  8  J  feet  in  diameter?  36  feet 
long,  and  rises  25  feet;  being  made  air-tight  with  water,  it  ascends  in  its  columnar  case 
which  IS  4  feet  in  diameter,  without  friction.      Tlie   space,  o  h.  Jig.  1309,  is  36    feet 

The  iron  cone,  which  serves  as  a  valve  to  the  charging-drum  or  cylinder,  is  raised 
and  lowered  by  means  of  a  chain  passing  round  a  worm-wheel,  which  is  turned  round 
by  an  endless  screw,  acted  upon  by  the  long  rod  at  c,  which  the  workman  can  move  bv 
hand  at  pleasure,  thereby  lowering  or  raising  the  end  of  the  short  lever  d  to  which  the 
valve  cone  is  suspended.  The  cord  by  which  the  workman  opens  or  shuts  the  air 
piston-valve  is  seen  at  «,  /  I  have  viewed  with  much  pleasure  the  precise  and  easv 
movements  of  this  feed-apparatus,  at  an  excellent  blast  furnace  in  Codner  Park  iron 
works. 

SMOKE  PREVENTION.     Among  the  fifty  several   inventions  which  have  been 
patented  for  ell ecting  this  purpose,  with  regard  to  steam-boiler  and  other  lar^-e  furnaces 
very  few  are  sufficiently  economical  or  effective.     The  first  person  who  investigated  this 
subject  m  a  truly  philosophical  manner  was  Mr.  Charles  Wye  WUliams,  managing  director 
of  the  Dublin  and  Liverpool  Steam  Navigation  company,  and  he  also  has  had  the  merit 
of  constructing  many  furnaces  both  for  marine  and  land  steam-engines,  which  thoroughly 
prevent  the  production  of  smoke,  with  increased  energy  of  combustion,  and  a  more  or 
less  considerable  saving  of  fuel,  according  to  the  care  of  the  stoker.    The  specific  inven- 
tion, for  which  he  obtained  a  patent  in  1840,  consists  in  the  introduction  of  a  proper 
quantity  of  atmospheric  air  to  the  bridges  and  flame-beds  of  the  furnaces,  througha 
great  number  of  small  orifices,  connected  with  a  common  pipe  or  canal,  whose  aitacan 
be  increased  or  diminished,  according  as  the  circumstances  of  complete  combustion  mar 
require,  by  means  of  an  external  valve.     The  operation  of  air  thus  entering  in  smaU 
jets  into  the  half-burned  hydro-carburetted  gases  over  the  fires,  and  in  the  first  flue,  is 
their  perfect  oxygenation,  the  development  of  all  the  heat  which  that  can  produce,  and 
£®  ^^^11^   prevention   of  smoke.      One  of  the   many   ingenious  methods  in  which 
Mr.  Williams  has  carried  out  the  principle  of  what  he  justly  calls  his  Argand  furnace. 
la  represented  in ;Jg.  1310,  where  a  is  the  ash-pit  of  a  steam  boiler  furnace;  b,  is  the 


c 


•         •        •       •-       .       •        •••••# 

•         •        •       •-        •       •        »       •       •         •        •        • 


mouth  of  a  tube  which  admits  the  externa!  air  into  the  chamber  or  iron  box  of  distri- 
buuon,  c,  placed  immediately  beyond  the  fire-bridge,  g,  and  before  the  diffusion  or 


664 


SOAP. 


S^era'^Tht/in  I'^^Z^^T.^J,^^^^^^  -'t^er  with  round  or  oblon, 

which  may  have  its  fire-brick  lin^g  alL  perforat^  1^  ^^'  ^^^'  '^^  ''  '^'  ^''-^^^^ 
)ects  in  front, and  it, as  well  as  the  sidw  andaTh^H**  ^" f^P^^ /ases,  the  fire-door  pro- 
of  perforated  fire-tiles,  enclosed  in  common  bS^^rk^^^  ^'''''"^^'  ^^^  ^^"^tnicted 
which  the  air  may  be  admitted  in  Te^n]atldZsnih.\^T  ^"^^^"^ediate  space, into 

X^^if e^Sc£^^^^  t^rsSter  '^  -^-^"^  • 

of  the  house  of  cimrns  of  t^eTue^^^^^^^^^^    fnnlTr"  ^^  S?°H^  ^'^^^^^i^'*  <^ommitt«i 
Uoa  to  many  furnaces  of  the  largest  S^^^  f  ^r-  Wmiam^,^  p,^,^^  j„^^„. 

worth,  of  Manchester,  who,  mountini^n  the  fii^sfSf,!.  '^^"'^"^  ^y  ^''  HenryHoulas- 
jn  an  external  dial  index,  succeeded  In  observi^^  ^Z^^"''^^''^'^!^  ''^>  ^^ich  act^ 
duced  by  varying  the  introduction  of    he  aiHe  s  Infn  ,7  ^"^*^^*>»  oftemperature,  pro- 
out  of  the  furnace.    He  thereby  demons  rati  that  20  T'  "^^^"''^^  ^^««  P«««i«8 
easily  obtained  from  the  fuel  when  Mr  wni:       ,^  ?^  ^^^  ^^^^'  ^^^^  ^eat  could  be 
the  fire  was  left  to  burn  in  ^re'usu'^rr^rd  tf^^^r^' "^^^^^^ 
volumes  of  smoke.    It  is  to  be  hoped,  that  a  kw  win  k«     ^  P«>duction  of  the  usual 
parliament  for  the  suppression,or  aneast  aLtement  nf  th''^''"^  '°  '^"""^*  session  of 
disfigures  and  pollutes  many  Darts  of  TnnHnnS?^^^"  nuisance,  which  so  greatlv 
while  it  acts  i^^juriously  oV^nTm^l^^nd  ve"etX^^^^      '^"^"'^  manufacturing  low  "s' 
Williams  for  his  indefatigable  and  d  sLterlstfd  1« w    -^  ^Much  praise  is  due  to  Mr 
faSoJ/L  &nr  -'-  -'  --- o^o^lTyt^^^^^^^  - 

oilf  w^fh  te  !:-lJtiJ^  Vo^  t\etS::L-T""1'-  ^^  -^"^«ed  fats  or 
matters,  when  subjeoeed  to  the^acUon  of  alk^lfT      "^^^^»^'"g   l^nen,  <fec.      Fatty 
being  converted  into  three  diiilren    acids  ^uIT  /^^  •'  "''^^'^*^  *  remarkable  chang/ 
these  acids,  in  fact,  which  combkT4h  the  Li    •   'T^'  margaric,  and  oleic;  and  it  S 
analogous  to  the'  neutro-saTinr  &)me  ch^?;«?  '  '^?''^  Pf^Po^tions,  to  form  compound" 
every  compound  which  may  resulftai  uTunLn'''rT  ^^^^^V^e  under  the  title  soap' 
metallic  oxydes-a  latitude  of  rmenclaTure  lh?.h    ""^  ^^'^  T'^'  ^^^  ^^^^"s  earths  and 
«nd  which  would  perplex  the  manufaclurer  '°°'"''"  ^'"^"^^^  ^^"'^^^  "^^oS^ise, 

j;a|rdreS^r?orii?t^^^^  consistence;  the 

by  that  of  potash.     The  nature  of  the  Sts  contr^buteraV''"  ""^  "^^  "P«"  ^^^«'  '^^  l«ter 
of  soaps  J  thus  tallow,  which  contains  much  steari^^^^^  '^"  consistenc. 

a  more  consistent  soap  than  liquid  oi^will  do  whinh  .      •"''"I^?''"^  ^'^^  Potash 
drying  oils,  such  as  those  of  hns2ed  and  poppy,t;oJuefthe°^^^^^^^^  ''  oleine.^Tb. 

1.  Of  the  manufacture  of  hard  sonn      Thi  r  »    r  .P-         soltest  soaps, 
of  Europe,  is  usually  talloi,  and    „  firslu'hern  larl'^^         V""'  "^^^^^^^  <=«"ntrie, 
grease  are  saponified  by  soda,  with  diffe  ent  de^^^^^^^^^  ^^^-    ^^«"^^^»t  species  of 

tweet  almond,  rapeseed,  and  castor  oil  •  and  amnn-  Ml  ?1'^^ '  ^f'^^"^  «"«>  ^he  olive, 
butter,  are  most  easily  'saponified.  Acco^din/ ^o  the  n Ir '''  'fV'  *^"^  grease,  and 
SIX  or  seven  days  are  required  to  comnCrfhp  ro.^»/?'^'^V'^  ^^  ^^^  ^^^^^^  Kingdom, 
day  or  two  more  for  settling  the  imS.es  f  It  .n^f  ^^"  °^  ^  P""  °^  ^^'^  soap,;nd  a 
of  tallow  are  estimated  to  VoduJ?  one  toi  of  --^  '  '"''•J"*  ^'*'"'  ^^  ^^  ^  ^^^^ 
manufactories  the  tallow  usK  be  ^ai^nmed  w1^^^^^  i  ^"^"  ^^^^^^  ^^^  i"  miny 

soap  was  converted,  in  the  course  of  t^e  process  i Jin  \'^  i'^''  *°^  '^^  ''^^^Jt^^?  ^ft 
of  muriate  of  soda,  or  weak  kelp  levs  in  suffip.Vn,  '       ?  ^^'^  ^^'^P'  *>y  ^^^  introduction 
of  soda  by  the  reaction  of  the  potSh  uno^  tZ  n   ?'f  '?  ^"™^^^  the  proper  quan^Sy 
potash,  and  the  diminished  price  Is  weU  as  imnrnv^i'^  'f '*  .^"^  ^«  ^4^  prfce  of 
led  to  their  general  adoption  in  soaiS.      improved  quality  of  the  crude  sodas,  have 
tains  in  general  about  36  per  cem  of  rp«1  ^n/      !^*"^'^  "'^^  ^^^  ^^^  soap-boiler  con 
muriate  of  soda,  and  more^or  fess  undecornnniH'"  ^^l  ^^ateof  dry  carbonat^,  mS  with 
ash,  made  from  sulphate  of  sodl  in  whiT^K^'^  sulphate.    I  have  met  lately  with  s^l 
jnperfectlydecompSsed?af  ^^ii^ai^'r^^^^^^^^  J-- - '"  woJkrd^a^S"^- 

TenSl"'''V-   T  ^"'"«"«  to  the  sciaranulctu^^^^^^^  circumstance  equally 

lenerifl^e  contain  from  18  to  24  npr  /.^.m^r       i      ?  '    ^"^  barillas  from  Spain  and 

employed  in  England;   l^iHa  bein/ suono.Pd'^^^^  '^^'    ^^'  ^^^^'^  i"  both  s^a^es^s 

%P>  -  ^^^^''''''''''''^-^^om^^^^  '"""'  '"  '''''  •  ^"^'  white  or  cLS 

ine   crude   soda   of   eithpr   n«j    v  • 

cylindrical  cast-iron  vats,7roL  g  to  T^^ftet  w^Tan'd  f    '%^  ^^^^^^^^  ^^^^    ^-«  « 
kyer  consisting,  of  course,  of  unslaked  or^hpiiS^^^^^  4  to  5  feet  deep;  the  lowest 

perforated  with  holes,  and  a  lateral  tb^lur^^^^^^^  The  vats  have  a  false  botro^' 

laug,  similar  to  the  S,ine  of  the  Frents^  ""^^^^  i^  t£  'lin^rtri^LVcrcreB 


SOAP. 


665 


mid  caustic,  arter  infiltration  through  the  beds  of  lime.    The  quantity  of  lime  must  be 
proportional  to  the  carbonic  acid  in  the  soda. 

Upon  1   ton  of  tallow  put  into  the  soap  pan,  about  200  gallons  of  soda  ley,  of 
•pecific  gravity  1-040,  being  poured,  heat  is  applied,  and  after  a  very  gentle  ebullition 
of  about  4  hours,  the  fat  will  be  found  to  be  completely  saponified,  by  the  test  of  the 
^atula,  trowel,  or  pallet  knife;   for  the  fluid  ley  will  be  seen  to  separate  at  once  upon 
the  steel  blade,  from  the  soapy  paste.    Such  leys,  if  composed  of  pure  caustic  soda, 
would  contain  4  per  cent,  of  alkali ;  but  from  the  presence  of  neutro-saline  matter,  they 
■eldom  contain  so  much  as  2  per  cent. ;  in  fact,  a  gallon  may  be  estimated  to  contain 
not  more  than  2  ounces ;  so  that  200  gallons  contain  25  pounds  of  real  soda.    The  fire 
being  withdrawn  from  the  soap  pan,  the  mass  is  allowed  to  cool  during  one  hour,  or  a 
little  more,  after  which  the  spent  leys,  which  are  not  at  all  alkaline,  are  run  off  by  a  spigot 
below,  or  pumped  off  above,  by  a  pump  set  into  the  pan.    A  second  similar  charge  of  ley  is 
now  introduced  into  the  pan,  and  a  similar  boiling  process  is  renewed.     Three  such  boils 
may  be  given  in  the  course  of  one  day's  work,  by  an  active  soap-maker.  Next  day  the  same 
routine  is  resumed  with  somewhat  stronger  leys,  and  so  progressively,  till,  towards  the  sixth 
day,  the  ley  may  have  the  density  of  M60,  and  will  be  found  to  contain  6  per  cent,  of  real 
8oda.»     Were  the  ley  a  solution  of  pure  caustic  soda,  it  would  contain  at  this  density  no 
less  than  14f  per  cent,  of  alkali.     The  neutro-saline  matter  present  in  the  spent  l»y  is 
essential  to  the  proper  granulation  and  separation  of  the  saponaceous  compound ;  for 
otherwise  the  watery  menstruum  would  dilute  end  even  liquefy  the  soap.    Supposintr 
12J  cwts.  of  tallow  to  yield  upon  an  average  20  cwts.  of  hard  soap,  then  20  cwts.  of  tallow 
will  produce  32  cwts. ;  and  as  its  average  contents  in  soda  are  6  per  cent.,  these  32  cwts. 
should  require  1-52  cwts.  of  real  soda  for  their  production.     If  barilla  at  20  per  cent, 
be  the  alkaii  employed,  then  7-6  cwts.  of  barilla  must  be  consumed  in  the  said  process. 
11  the  alkali  be  soda-ash  of  40  per  cent.,  half  the  weight  will  of  course  suffice.     I  have 
reason  to  believe  that  there  is  great  waste  of  alkali  incurred  in  many  soap-works,  as  6  cwts. 
01  soda-ash,  of  at  least  30  per  cent.,  are  often  expended  in  making  1  ton  of  soap,  being  50 
per  cent,  more  than  really  enters  into  the  composition  of  the  soap. 

^  The  barillas  always  contain  a  small  proportion  of  potash,  to  which  their  peculiar  value, 
in  makmgaless  brittle  or  more  plastic  hard  soap  than  the  factitious  sodas,  may  with 
great  probability  be  ascribed.  Chemistry  affords  many  analogies,  especially  in  mineral 
waters,  where  salts,  apparently  incompatible,  co-exist  in  dilute  solutions.  We  may  thus 
conceive  how  a  small  quantity  of  stearate  or  oleate  of  potash  may  resist  the  decomposing 
action  of  the  soda  salts.  The  same  modification  of  the  consistence  of  hard  soap  may. 
However,  be  always  more  conveniently  produced  by  a  proper  admixture  of  oleine  with 
stearin  e. 

Soda  which  contains  sulphurets  is  preferred  for  making  the  mottled  or  marbled  soap, 
whereas  the  desulphureted  soda  makes  the  best  white  curd  soap.  Mottling  is  usually 
given  in  the  London  soap-works,  by  introducing  into  the  neariy  finished  soap  in  the 
pan  a  certain  quantity  of  the  strong  ley  of  crude  soda,  throush  the  rose  spout  of  a 
waterinj-can.  The  dense  sulphureted  liquor,  in  descending  through  the  pasty  mass, 
causes  the  marbled  appearance.  In  France  a  small  quantity  of  solution  of  sulphate 
ot  iron  is  added  during  the  boiling  of  the  soap,  or  rather  with  the  first  service  of 
the  leys.  The  alkali  seizes  the  acid  of  the  sulphate,  and  sets  the  protoxyde  of  iron 
free,  to  mingle  with  the  paste,  to  absorb  more  or  less  oxygen,  and  to  produce  thereby 
a  variety  of  tints.  A  portion  of  oxyde  combines  also  with  the  stearine  to  form  a 
meta  he  soap.  When  the  oxyde  passes  into  the  red  state,  it  Rives  the  tint  called  maiUeau 
Isabelk.  As  soon  as  the  mottl^r  has  broken  the  paste,  and  made  it  pervious  in  all  directions, 
he  ceases  to  push  his  rake  from  right  to  left,  but  only  plunges  it  perpendiculariy,  till  he 
reaches  the  ley;  then  he  raises  it  suddenly  in  a  vertical  line,  making  it  act  like  the 
stroke  of  a  piston  in  a  pump,  whereby  he  lifts  some  of  the  ley,  and  spreads  it  over  the 
surface  ol  the  paste.  In  its  subsequent  descent  through  the  numerous  fissures  and  chan- 
nels, on  Its  way  to  the  bottom  of  the  pan,  the  colored  ley  impregnates  the  soapy  particles 
in  various  forms  and  degrees,  whence  a  varied  marblin?  results"^ 

Three  pounds  of  olive  oil  afford  five  pounds  of  marbled  Marseilles  soap  of  good  qua- 
lity, and  only  four  pounds  four  ounces  of  white  soap;  showin-  that  more  water  is 
retained  by  the  former  than  the  latter.  Oils  of  grains,  as  linseed  and  rapeseed,  do  not 
afford  so  solid  a  soda  soap  as  oil  of  olives;  but  tallow  affords  a  still  harder  soap  with 
soda  Some  of  the  best  Windsor  soap  made  in  London  contains  one  part  of  olive  oU 
(callipoli)  for  every  nine  parts  of  tallow.  Much  of  the  English  hard  soap  is  made 
with  kitchen  and  bone  fat,  of  a  very  coarse  quality ;  the  washing  of  the  numerous 
successive  leys,  however,  purifies  the  foul  fats,  and  deprives  them  of  their  offensive  smell 
in  a  great  decree.  It  is  common  now  at  Marseilles  to  mix  ten  per  cent,  of  the  oil  of 
grains  with  olive  oil ;  for  which  purpose  a  large  proportion  of  the  oils  extracted  from  seeds 

•  According  to  my  own  ezperimenta  upon  the  soda  ley  used  in  the  London  s(«p-works. 


»!•.  I 


666 


SOAP. 


washing ;  because  Che  t.o^p«i«  of  ft/?Ise  to  .mllX"'""  """^  '"''  ""*'  *■" 
temperature,  and  letTcoolTo  he^^i„,  ii„r  .r  °!f '  '*."°"  "  "'e  '""«'  I^s^iWe 

•nenon  to  be  due  toSfcalStracHon      r„  ,        .   "f  '!.T-"?'."^«'  P™"'"?  "-e  pheno-' 
risen  from  54»  to  140»  P^       attraction.    In  some  trials  of  this  kind,  the  themomeler  hat 

When  four  pans  of  cSi™  nil  »~  V.vJ.  „-.k  *  '"""  """i*'  ""^  ''"^"J^  "  <■""»  '0°  to  1 1'. 
is  now  the^eLral  pracfe  arCl^s  .rn^:'°^'"-P''^'"'*'°^  linseed  oil,  m 

tTTd^;i^^r;^;;^ersi4tatv^^^^^^^ 

leys  should  not  be  caustic  .arextr^ord?n«rt  I       .-"^^P  '"  ^"^"'^  ^^^^^^^  "^^  that  the 
fairly  established,  to™t?^u"rthe  "t'o'ngtty       '"°  ''"'  '"''  '"'"  '"^  ^PonihcaUo. i. 

in.^:h^rsn::haT;irLTat"i^^^ 

SrelTa  LtSr5J:„^r!^;?o^  n"crS«'  ^"/-Ufe'ptii'SrcTri 
water  directly.  ^       *  ^*'*  ^  '^  "^^^  ^^^  '^«'«'-  ^^t,  because  it  receives  the  . 

144  pounds  of  o°l  viTld  «  M.'rJ^nl!       ^'"*  """  "'™"«''  "'  '^  "■™™  upon  No.  I. 
poundsof  soap™  0    IM  S'^uS;onri"68*"  ^Tf'  ""'?"'  "■""  '"'•o"  ^^0  to 244 
this  rate  nearly'eo  ponnd^oJoU  «e  consle^ '  "  ""' '"  ""^"^  '»« J"""-^  "^^J'' « 

.  OF  YELLOW  OR  ROSIN  SOAP. 

of?^Sg\ransSji*^.rin''!.dd"  a'dtmnTofr' " ""'  ""T""  susceptible, lilce fa... 

itself     The  more  caustctSe  alMrt2e7lcl[^^^^^^^^^^^ 

IS  made  with  it.    Hence  fat  of  3p  Wi„!l  i„  .       j      v,    *  ""*  resinous  compound  which 

with  the  rosin,  themZ,ultl^rA^ru'^i?y^^'?^'''"'^\"'r  ^  ""^  "'»»« 
As  alkaline  matter  cannot  be  nSi^S  by^;i„  ?.  '^Zl"  "^f  "  '^T/™"'  **'"«  S"""- 
«o«p  poor  in  fat,  and  is  r^irto  »m  .!i  L^  r' ,.  P'^««"'<»  'ts  peculiar  acrimony  in  a 

fibres  So  which  it  is  appM^^R  fe  sad^afrZla  ^i"'"''  '"^""'  ""''  ""  »"'«'•  »"'"»» 

of  rosin  in  soap  moJ?  than  an^^'a  t'^olr^t  i^l  „7  ftY'Tromwh  '^  ^T^*^" 
said,  It  IS  obviously  needlpcs  tn  moL-^  .k^  ,^o-     **  j^'/^  "^  ^^'-     irom  what  we  have  just 

io.,  therefore,  is  fir.tr31^rLrtfer:lSXTnl^^uUtS;r^^ 


SOAP. 


667 


service  or  chaise  of  ley,  namely,  when  this  ceases  to  be  absorbed,  and  presenres  in  the 
boiling-pan  its  entire  causticity,  to  add  the  proportion  of  rosin  intended  for  the  soap. 
In  order  to  facilitate  the  solution  of  the  rosin  in  the  soap,  it  should  be  reduced  to  coarse 
powder,  and  well  incorporated  by  stirring  with  the  rake.  The  proportion  of  rosin  is 
usually  from  one  third  to  one  fourth  the  weight  of  the  tallow.  The  boil  must  be  kept 
up  for  some  time  with  an  excess  of  caustic  ley;  and  when  the  paste  is  found,  on  cooling 
m  sample  of  i^  to  acquire  a  solid  consistence,  and  when  diffused  in  a  little  water,  not 
to  leave  a  resinous  varnish  on  the  skin,  we  may  consider  the  soap  to  be  finished.  We 
next  proceed  to  draw  off  the  superfluous  leys,  and  to  purify  the  paste.  For  this 
purpose,  a  quantity  of  leys  at  80°  B.  being  poured  in,  the  mass  is  heated,  worked 
well  with  a  rake,  then  allowed  to  settle,  and  drained  of  its  leys.  A  second  service  of 
leys,  at  4°  B.,  is  now  introduced,  and  finally  one  at  2°;  after  each  of  which,  there  is  the 
usual  agitation  and  period  of  repose.  The  pan  being  now  skimmed,  and  the  scum  re- 
moved for  another  operation,  the  soap  is  laded  off  by  hand-pails  into  its  frame-moulds.  A 
little  palm  oil  is  usually  employed  in  the  manufacture  of  yellow  soap,  in  order  to  correct 
the  flavor  of  the  rosin,  and  brighten  the  color.  This  soap,  when  well  made,  ought  to  be 
of  a  fine  wax-yellow  hue,  be  transparent  upon  the  edges  of  the  bars,  dissolve  readily  in 
water,  and  afford,  even  with  hard  pump-^ater,  an  excellent  lather. 

The  frame-moulds  for  hard  soap  are  composed  of  strong  wooden  bars,  made  into  the 
form  of  a  parallelogram,  which  are  piled  over  each  other,  and  bound  togelher  by  screwed 
iron  rods,  that  pass  down  through  them.  A  square  well  is  thus  formed,  which  in  large  soap 
lactories  is  sometimes  10  feet  deep,  and  capable  of  containing  a  ccuple  of  tons  of  soap. 

Mr.  Sheridan  some  time  since  obtained  a  patent  for  combining  silicate  of  soda  witk 
hard  soap,  by  triturating  them  together  in  the  hot  and  pasty  state  with  a  crutch  in 
•n  iron  pan.  In  this  way  from  10  to  30  per  cent,  of  the  silicate  may  be  introduced. 
Such  soap  possesses  very  powerful  detergent  qualities,  but  it  is  apt  to  feel  hard  and  be 
•omewhat  gritty  in  use.  The  silicated  soda  is  prepared  by  boiling  ground  flints  in  « 
•trong  caustic  ley,  till  the  specific  gravity  of  the  compound  rises  to  nearly  double  the 
density  of  water.  It  then  contains  about  35  grains  of  silica,  and  46  of  soda-hydrate,  u 
100  grains.* 

Hard  soap,  after  remaining  two  days  in  the  frames,  is  at  first  divided  horizontally 
into  parallel  tablets,  3  or  4  inches  thick,  by  a  brass  wire ;  and  these  tablets  are  again  cut 
vertically  into  oblong  nearly  square  bars,  called  wedges  in  Scotland. 

The  soap-pans  used  in  the  United  Kingdom  are  made  of  cast  iron,  and  in  three  sepa- 
rate pieces  joined  together  by  iron-rust  cement.  The  following  is  their  general  form : — 
The  two  upper  frusta  of  cones  are  called  curbs ;  the  third,  or  undermost,  is  the  pan,  to 
which  alone  the  heat  is  applied,  and  which,  if  it  gets  cracked  in  the  course  of  boiling, 
may  easily  be  lifted  up  within  the  conical  pieces,  by  attaching  chains  or  cords  for  raising 
it,  without  disturbing  the  masonry,  in  which  the  curbs  are  firmly  set.  The  surface  of 
the  hemispherical  pan  at  the  bottom,  is  in  general  about  one  tenth  part  of  the  surface 
of  the  conical  sides. 

The  white  ordinary  tallow  soap  of  the  London  manufacturers,  called  curd  soap,  con- 
eists,  by  my  experiments,  of — fat,  62 ;  soda,  6 ;  water,  42 ;  =  100.  Nine  tenths  of  the 
fat,  at  least,  is  tallow. 

I  have  examined  several  other  soaps,  and  have  found  their  composition  somewhat 
different. 

The  foreign  Castile  soap  of  the  apothe-       A  perfumer's  white  soap  was  found  to 
cary  has  a  specific  gravity  of  1'0705,  and 
consists  of — 

Soda        ... 

Oily  fat  -  -  - 

Water  and  coloring-matter 

100-0 
English  imitation  of  Castile  soap,  spec, 
grav.  0-9669,  consists  of— 

Soda      -  -  -  -     10-5 

Pasty  consistenced  fat  -  -    75-2 

Water,  with  a  little  coloring-    - 
matter  ...     14*3 


100-0 


A  perfumer's  white 
consist  of — 

soap  was 

found 

Soda 

. 

-    9 

Fatty  matter 
Water      - 

- 

-  76 
.  16 

100 

Glasgow  white  soap- 
Soda 

. 

.    6*4 

Tallow    - 

. 

-  600 

Water    - 

- 

-  33-6 

lOO-O 


e  By  my  own  experiments  upon  the  Uquld  silicate  made  at  Mr.  Gibbs's  excellent  soap  tetoqr. 


668 

Glasgow  brown  rosin  soap^. 
Soda        -  .  . 

Fat  and  rosin 
Water 


SOAP. 


100*0 


A  London  cocoa-D'it  oil  soap  was  found 
to  consist  of—  *"uau 

Soda        -  ,  ^  - 

coc„.„u,  ,aM       :     :  2,: 

•  -  73*5 


A    poppy-nut-oil 
of— 

Soda 

OU 

Water 


100-0 


^lli''*^''!"^'"^.^^^^   ^°*P  ^«8   sufficiently 
•olid ;    but  It  dissolved  in  hot  water  w  th 

Zl'""' ^r^'^'l-     It  is  called  marine  slap, 
because  it  washes  linen  with  sea  water. 


hard    soap   consisted 

-  7 

-  76 

-  17 

_  100 

rhe  soap  known  in  France  by  the  name 
of  soap  tn  tables,  consists,  according  to 
M.  Thenard's  analysis,  of—  ^ 

Soda  -  .  .  4.g 

Fatty  matter  .  .         50.2 

Water         .  .  .  ^^.^ 

JOO-0 
M.  D'Arcet  states  the  analysis  of  M«iu 
seilles  soap  at— 
Soda  -  -  -  fi 

Water        -  -  -         34 

loo 

SOFT  SOAP. 

quantity  of  it,  and  become  solid  •  th^v Tr«  T     ■    ^  T  ..   *    ^®  ^°"°^^  ^^^^^  »  large 
.;.h.eblerWiveXa^lV^^^^^^ 

mcKlerate  consist'ence.     This  feeble7l:sW;^o^^^^^^^^^  ^^^fj'  P«^*^^  «-P  of 

if  there  be  a  small  excess  of  the  alkali      Tt  iJthlt^r       ?  ^   to  deliquesce,  especially 
the  leys ;  and  the  washing  or  r'Lg^^^^^^^  '^  ^^P^-'ate  it  frsm 

ble  in  the  soft.     Perhans  howpvpr  tific  P^^^^^'^f  °?  *^«  hard-soap  process,  is  inadmis&J 
effected  by  usingTensr'leys  of  m^^^^^^^  or  abstraction  of  water  mi^ht  be 

wda  change  the  pS  intraso^aTan  Iv '^^^^^^^       Those  of  muriate  or  sulphate  of 
solubility,  more  aUcaline  reactlonT^nriower  pd^^^  ^7^  ^''  ""P^rior 

purposes,  and  especially  for  scoudng  wX  y'arnl^d  1  '^7'  "  '"'^""*  '^^  ""^^ 

Soft  soaps  are  usually  made  in  this  country  with  whalp  Jp«1  «r  j  r        . 

and  a  cerla  n  quantity  of  tallow  •  on  thp  nnnL  l  .u  .'  ^^*''  °^^^^'  »"<^  Imseed  oUs, 
rapeseed,  linseed,  poppy-sej?,  a„VcoLa^^^^^^^^^^^  ^^'  ""'  "^  ^^°^P««^d'  ^^^same^ 

tallow  is  added,  ;s^nGrea7  Britain,  th^  ob7ecf  ^To  nr^H  ''T"/ "^  ^^^^^  o"^'  ^hen 
grains  of  stearic  soap  in  the  transparent  mass  call S  ^fi^  '^  l^'^^  ^"^  somewhat  solid 
•embles  the  granular  texture  of  a  fi|  ^^""^^       ^'^'^  ^^^^  ^*P  ^^^"^  ^^ 

The  potash  leys  should   be  made  perfectlv  can«t.\.    o«,i     r    .  , 
strengths ;  the  weakest  being  of  speci^c  eravitv  iT  '     a  .u^  *'  ^^^''  ^^°  ^^^^^^n* 
1-25.     Being  made  from  the  potasres  of  comlrcf  th^K  *^^  ^^^^^^^^t'  ^'20,  or  even 
60  per  cent.,  and  often  less,  of  real  alkali  th^  lev.'  T.    '^  '^1'^- "  '^^'^""^  "'^'^^  ^^^^ 
double  their   alkaline  strength      tha\ 's '^saJ  a  Jola^^^^^^^  '"  specific  gravity  to 

density,  would  be  fully  twice  as  strong      THp  fXn  ^^r^^^."^  of  pure  potash,  of  the  same 

.pectable  manufacturers  of  sol    IZ^lsaJor^eTT^  ''  '^"  F'""'^''  ^°"°^«J  ^y  re. 
upon  the  continent.  ^  ^        "  *"'^''  ^"^'"^  naturally  or  artificially  green) 

A  portion  of  the  oil  being  poured  into  the  pan,  and  heated  ir^  n«o  1    .u    u  •,• 
of  water,  a  certain  quantity  of  the  weaker  lev  k  fntrJ     !^  ^?  ^^T^^  *^^  ^o»'*"S  P«'nt 
as  to  bring  the  mixfure  to  a  boiUngstate     Then  .n      '''^'   *^^  ^'^  being  kept  up  so 
jernately,  till  the  whole  quanUty  of  oLin^^^^^^^  *"^.  ley  are  added  al- 

lilion  is  kept  up  in  the  gentlest  manner  oossiblP  IJ  ^^'^  *'  introduced.  The  ebul- 
ndded,  till  the  workman'judgel  trs^ponEuirto^be"?^^^^^^^^^^^ 

progressively  less  tumultuous,  the  frothy  mass  sub^irL  .k^  ♦  ^^^  ^^''"'^  becomes 
it  gradually  thickens.  The  operatin  is  considered  fn  hi  fi  P^f  ^.^T'  transparent,  and 
to  affect  the  tongue  with  an  acrid  plgenc/t^^^^^  IntM^""^"^  ""^'^  '^^  ^^''^  ^'^'^ 
•nd  when  a  little  of  the  soap  placed  to  coo7  ur^n  1  *"  '^*"^f  *"d  opacity  disappear, 
consistency.  ^  ^  '*'*^  "P""*  *  ?lass  plate,  assumes  the  proper 

A  peculiar  phenomenon  may  beremarkpd  in  «}»o/.«^i-         1..  ,     « 
of  the  quality  of  the  soap.    wLn  iSe^rformed  .Z  '^"fl^^i ''?  *^^"^'  *  ^^"^  *^"^^"on 
.  fraction  of  an  inch  broaJ,  this  is    up  'Ud  "o In^^  the  htlle  patch,  an  opaque  zone, 

caUed  the  */ren^f A;  when  it  is  absent  lhr«n»n-f^  *'°"'P'^'^  saponification,  and  1^ 
.one  soon  vanifheJ  after  be  ng  disSt  y  seen  thf  1'"  T "^J^^  ''r^'''  ^'^^'^  '"^^ 
When  it  occurs  in  the  best  ^U  the  1^ TV^rLTa^^^^^^^^^^^^ 


SOAP. 


669 


by  removing  the  fire,  and  then  adding  some  good  soap  of  a  previous  round,  to  cool  it  down^ 
and  prevent  further  change  by  evaporation. 

200  pounds  of  oil  require  for  their  saponification — 72  pounds  of  American  potash  of 
moderate  quality,  in  leys  at  15®  B. ;  and  the  product  is  460  pounds  of  well-boiled  soap. 

If  hempseed  oil  have  not  been  employed,  the  soap  will  have  a  yellow  color,  instead 
of  the  green,  so  much  in  request  on  the  continent.  This  tint  is  then  given  by  the  ad- 
dition of  a  little  indigo.  This  dye-stuff  is  reduced  to  fine  powder,  and  boiled  for  some 
hours  in  a  considerable  quantity  of  water,  till  the  stick  with  which  the  water  is  stirred 
presents,  on  withdrawing  it,  a  gilded  pellicle  over  its  whole  surface.  The  indigo  paste 
dififused  through  the  liquid,  is  now  ready  to  be  incorporated  with  the  soap  in  the  pan, 
before  it  stiffens  by  cooling. 

M.  Thenard  states  the  composition  of  soft  soap  at — potash  9-5,  4-  oil  44*0,  4-  water 
46-5,  =  100. 

Good  soft  soap  of  London  manufacture,  yielded  to  me — potash  8*5,  -{-  oil  and  tallow 
45,  -j-  water  46*5. 
Belgian  soft  or  green  soap  afforded  me — potash  7,  -(-  oil  36,  -|-  water  57,  =  100. 
Scotch  soft  soap,  being  analyzed,  gave  me — potash  8,  -j-  oil  and  tallow  47, -j-  water  45w 
Another  well-made  soap — potash  9,  -f-  oil  and  fat  34,  -j-  water  57. 
A  rapeseed-oil  soft  soap,  from  Scotland,  consisted  of — potash  10,  +  oil  51-66,  -4- 
water  38-33. 

An  olive-oil  (gallipoli)  soft  soap,  from  ditto,  contained — potash  with  a  good  deal  of 
carbonic  acid  10,  oil  48,  water  42,  =  100. 

A  semi-hard  soap,  from  Verviers,  for  fulling  woollen  cloth,  called  savon  economiqut, 
consisted  of,  potash  11-5,  -{-  fat  (solid)  62,  -|-  water  26-5,  =  100. 
The  following  is  a  common  process,  in  Scotland,  by  which  good  soft  soap  is  made  :— 
273  gallons  of  whale  or  cod  oil,  and  4  cwts.  of  tallow,  are  put  into  the  soap-pan,  witu 
250  gallons  of  ley  from  American  potash,  of  such  alkaline  strength  that  1  gallon  con- 
tains 6600  grains  of  real  potash.     Heat  being  applied  to  the  bottom  pan,  the  mixture 
froths  up  very  much  as  it  approaches  the  boiling  temperature,  but  is  prevented  from 
boiling  over  by  being  beat  down  on  the  surface,  within  the  iron  curb  or  crib  which  sur* 
mounts  the  caldron.     Should  it  soon  subside  into  a  doughy-looking  paste,  we  may  infer 
that  the  ley  has  been  too  strong.     Its  proper  appearance  is  that  of  a  thin  glue.     We 
«  should  now  introduce  about  42  gallons  of  a  stronger  ley,  equivalent  to  8700  gr.  of  pot- 
ash per  gallon ;  and  after  a  short  interval,  an  additional  42  gallons ;   and  thus  suc- 
cessively till  nearly  600  such  gallons  have  been  added  in  the  whole.     After  suitable  boil- 
ing  to  saponify  the  fats,  the  proper  quality  of  soap  will  be  obtained,  amounting  in  quan- 
tity to  100  firkins  of  64  pounds  each,  from  the  above  quantity  of  materials. 

It  is  generally  supposed,  and  I  believe  it  to  be  true,  from  my  own  numerous  experi- 
ments upon  the  subject,  that  it  is  a  more  difficult  and  delicate  operation  to  make  a  fine 
•oft  soap  of  glassy  transparency,  interspersed  with  the  figged  granulations  of  stearate  of 
potash,  than  to  make  hard  soap  of  any  kind. 

Soft  soap  is  made  in  Belgium  as  follows  :— For  a  boil  of  18  or  20  tons,  of  100  kilo- 
^ammes  each,  there  is  employed  for  the  leys — 1500  pounds  of  American  potashes,  and 
600  to  600  pounds  of  quicklime. 

The  ley  is  prepared  cold  in  cisterns  of  hewn  stone,  of  which  there  are  usually  five  in  « 
range.  The  first  contains  the  materials  nearly  exhausted  of  their  alkali ;  and  the  last 
the  potash  in  its  entire  state.  The  ley  run  off  from  the  first,  is  transferred  into  the  se- 
cond ;  that  of  the  second  into  the  third ;  and  so  on  to  the  fifth. 

In  conducting  the  empatage  of  the  soap,  they  put  into  the  pan,  on  the  eve  of  the  boil- 
ing-day, 6  aimes  (1  ohm,  =  30  gallons  imperial)  of  oil  of  colza,  in  summer,  but  a  mixture 
of  that  oil  with  linseed  oil  in  winter,  along  with  2  aimes  of  potash  ley  at  13°  B.,  and 
leave  the  mixture  without  heat  during  eight  hours.  After  applying  the  fire,  they  con- 
tinue to  boil  gently  till  the  materials  cease  to  swell  up  with  the  heat ;  after  which,  ley 
of  16°  or  17®  must  be  introduced  successively,  in  quantities  off  of  an  aime  after  another, 
till  from  2  to  4  aimes  be  used.  The  boil  is  finished  by  pouring  some  ley  of  20°  B.,  so 
that  the  whole  quantity  may  amount  to  9|  aimes. 

It  is  considered  that  the  operation  will  be  successful,  if  from  the  time  of  kindling  the 
fire  till  the  finish  of  the  boil,  only  five  hours  elapse.  In  order  to  prevent  the  soap  from 
boiling  over,  a  wheel  is  kept  revolving  in  the  pan.  The  operative  considers  the  soap  to 
be  finished,  when  it  can  no  longer  be  drawn  out  into  threads  between  the  finger  and 
thumb.  He  determines  if  it  contains  an  excess  of  alkali,  by  taking  a  sample  out  daring 
the  boil,  which  he  puts  into  a  tin  dish  ;  where  if  ,it  gets  covered  with  a  skin,  he  pours 
fresh  oil  into  the  pan,  and  continues  the  boil  till  the  soap  be  perfect.  No  wonder  the 
Belgian  soap  is  bad,  amid  such  groping  in  the  dark,  without  one  ray  of  science ! 

SOFT  TOILET   SOAPS. 

The  soft  fancy  toilet  soaps  are  divisible  into  two  classes :  1.  good  potash  soap,  colored 
and  scented  in  various  ways,  forms  the  basis  of  the  Naples  and  other  ordinary  soft  8o«p« 


i 

'i 


■f!l 


670 


SOAP. 


of  the  perfbmer;  2.  pearl  soapy  (savon  nacrcy')  which  differs  from  the  other  both  in  phy^ 
leal  aspect  and  in  mode  of  preparation. 

Ordinary  soft  Toilet  Soap. — Its  manufactare  being  conducted  on  the  principles  already ' 
laid  down,  presents  no  difficulty  to  a  man  of  ordinary  skill  and  experience ;  the  only 
point  to  be  strictly  attended  to,  is  the  degree  of  evaporation,  so  as  to  obtain  soap  always 
of  uniform  consistence.  The  fat  generally  preferred  is  good  hog's  lard  j  of  which  thirty 
pounds  are  to  be  mixed  with  forty-five  pounds  of  a  caustic  ley  marking  IT*  on  Baume*8 
scale;  the  temperature  is  to  be  gradually  raised  to  ebullition,  but  the  boil  must  not  be 
kept  up  too  long  or  too  briskly,  till  after  the  empatage  or  saponification  is  completed,  and 
the  whole  of  the  ley  intimately  combined  with  the  fatty  particles;  after  this,  the  evapora- 
tion of  the  water  may  be  pushed  pretty  quickly,  by  a  steady  boil,  till  copious  vapors  cease 
to  rise.  This  criterion  is  observed  when  the  paste  has  become  too  stiff  to  be  stirred  free- 
ly. The  soap  should  have  a  dazzling  snowy  whiteness,  provided  the  lard  has  been  well 
refined,  by  being  previously  triturated  in  a  mortar,  melted  by  a  steam  heat,  and  then 
strained.  The  lard  soap  so  prepared,  is  semi-solid,  and  preserves  always  the  same  ap- 
pearance. If  the  paste  is  not  sufficiently  boiled,  however,  it  will  show  the  circumstance 
very  soon ;  for  in  a  few  days  the  soap  will  become  gluey  and  stringy,  like  a  tenacious 
mass  of  birdlime.  This  defect  may  not  only  be  easily  avoided,  but  easily  remedied,  by 
subjecting  the  paste  to  an  adequate  evaporation.  Such  soaps  are  in  great  request  for 
shaving,  and  are  most  convenient  in  use,  especially  for  travellers.  Hence  their  sale  has 
become  very  considerable. 

Pearl  soft  Soap. — It  is  only  a  few  years  since  the  process  for  making  this  elegant  soap 
became  known  in  France.  It  differs  little  from  the  preceding,  and  owes  its  beautiful 
aspect  merely  to  minute  manipulations,  about  to  be  described.  Weigh  out  20  pounds 
of  purified  hog's  lard  on  the  one  hand,  and  10  pounds  of  potash  ley  at  36*  B.  on  the 
other.  Put  the  lard  into  a  porcelain  capsule,  gently  heated  upon  a  sand-bath,  stirring 
^  constantly  with  a  wooden  spatula;  and  when  it  is  half  melted,  and  has  a  milky 
appearance,  pour  into  it  only  one  half  of  the  ley,  still  stirring,  and  keeping  up  the  same 
temperature,  with  as  little  variation  as  possible.  While  the  saponification  advances 
gradually,  we  shall  perceive,  after  an  hour,  some  fat  floating  on  the  surface,  like  a  film  of 
oil,  and  at  the  same  time  the  soapy  granulations  falling  to  the  bottom.  We  must  then 
add  the  second  portion  of  the  lev;  whereon  the  granulations  immediately  disappeai 
and  the  paste  is  formed.  After  conducting  this  operation  during  four  hours,  the  past* 
becomes  so  stiff  and  compact,  that  it  cannot  be  stirred ;  and  must  then  be  lightly  beaten. 
At  this  time  the  capsule  must  be  transferred  from  the  sand-bath  into  a  basin  of  warm 
water,  and  allowed  to  cool  very  slowly. 

The  soap,  though  completely  made,  has  yet  no  pearly  appearance.  This  physical 
property  is  developed  only  by  pounding  it  strongly  in  a  marble  mortar ;  whereby  all  its 
particles,  which  seemed  previously  separated,  combine  to  form  a  homogeneous  paste. 
The  perfume  given  to  it,  is  always  essence  of  bitter  almonds ;  on  which  account  the  soap 
is  called  almond  creartiy  crcme  d*amandes. 

HARD   SOATS   FOR   THE   TOILET. 

The  soaps  prepared  for  the  perfumer,  are  distinguished  into  different  species,  according 
to  the  fat  which  forms  their  basis.  Thus  there  is  soap  of  tallow,  of  hog's  Iturd,  of  oil  of 
olives,  of  almonds,  and  palm  oil. 

It  is  from  the  combination  of  these  different  sorts,  mingled  in  various  proportions,  and 
perfumed  agreeably  to  the  taste  of  the  consumer,  that  we  owe  the  vast  number  of  toilet 
soaps  sold  under  so  many  fantastic  names.  One  sort  is  rarely  scented  by  itself,  as  a  mix- 
ture of  several  is  generally  preferred;  in  which  respect  every  perfumer  has  his  peculiar 
secret.  Some  toilet  soaps,  however,  require  the  employment  of  one  kind  more  than  of 
another. 

Formerly  the  Windsor  soap  was  made  in  France,  wholly  with  mutton  suet ;  and  it  was 
accordingly  of  inferior  value.  Now,  by  mixing  son^  olive  oil  or  lard  with  the  suet,  a 
vei7  good  Windsor  soap  is  produced.  I  have  already  stated,  that  the  fat  of  the  London 
Windsor  is,  nine  parts  of  good  ox  tallow,  and  one  of  olive  oil.  A  soap  made  entirely 
with  oil  and  soda,  does  not  afford  so  good  a  lather  as  when  it  contains  a  considerable 
proportion  of  tallow. 

The  soaps  made  with  palm  oil  are  much  used ;  when  well  made,  they  are  of  excellent 
quality,  and  ought  to  enter  largely  into  all  the  colored  sorts.  They  naturally  possess  the 
odor  of  violets. 

The  soaps  made  with  oil  of  almonds  are  very  beautiful,  and  preserve  the  agreeable 
smell  of  their  perfume ;  but  being  expensive,  are  introduced  sparingly  into  the  mixtures 
by  most  manufacturers. 

Some  perfumers  are  in  the  habit  of  making  what  may  be  called  extempore  soaps,  em- 
ploying leys  at  36P  Baume  in  their  formation.  This  method,  however,  ought  never  to 
be  adopted  by  any  person  who  prefers  quality  to  beauty  of  appearance.  Such  soap  is, 
indeed,  admirably  white,  glistening,  contains  no  more  water  than  is  necessary  to  its  con* 


SOAP. 


671 


Btltntion,  and  may  therefore  be  sold  the  day  after  it  is  made.  But  it  has  counter-Daian- 
cing  disadvantages.  It  becomes  soon  very  hard,  is  difficultly  soluble  in  water,  and,  if 
not  made  with  tallow,  does  not  lather  well.  Hog's  lard  is  very  commonly  used  for  ma- 
king that  soap.  Twenty  kilogrammes  of  the  fat  are  taken,  to  ten  kilogrammes  of  soda 
lej',  at  36°  B.  (specific  gravity  1-324) ;  as  soon  as  the  former  is  nearly  fluid,  five  kilo- 
grammes of  the  ley  are  introduced,  and  the  mixture  is  continually  agitated  during  an 
hour  with  a  wooden  spatula.  The  temperature  should  never  be  raised  above  150°  Fahr. 
at  the  commencement  of  the  operation ;  at  the  end  of  one  hour,  five  other  kilogrammes 
of  ley  are  to  be  added,  with  careful  regulation  of  the  heat.  The  paste  thus  formed  by  the 
onion  of  the  fat  and  alkali,  ought  to  be  perfectly  homogeneous,  and  should  increase  in 
consistence  every  hour,  till  it  tecomes  firm  enough  to  be  poured  into  the  frame ;  during 
wklch  transfer,  the  essential  oils  destined  to  scent  it,  should  be  introduced.  Next  day 
the  soap  is  hard  enough;  nor  does  it  differ  in  appearance  from  ordinary  soap,  only  it 
requires  prompt  manipulation  to  be  cut  into  bars  and  cakes ;  for  when  neglected  a  day 
or  two,  it  may  become  too  brittle  for  that  purpose,  and  too  hard  to  take  the  impression 
of  the  stamps  in  relief.  Such  an  article  gets  the  name  of  little-pan  soap,  on  account  of 
the  small  quantity  in  which  it  is  usually  manufactured.  Hard  soap,  made  in  the  com- 
mon way,  is,  on  the  contrary,  called  large-pan  soap.  This  extemporaneous  compound  is 
now  seldom  or  never  made  by  respectable  manufacturers.  In  making  Windsor  soap,  the 
admixture  of  olive  oil  is  advantageous  ;  because,  being  richer  in  oleine  than  suet,  it  sa- 
ponifies less  readily  than  it,  and  thus  favors  the  formation  of  a  more  perfect  neutral  com- 
bination. When  the  soap  cuts,  or  parts  from  the  ley,  when  the  paste  becomes  clotty,  or. 
In  the  language  of  the  operative,  when  the  grain  makes  its  appearance,  the  fire  should 
be  immediately  withdrawn,  that  the  impurities  may  be  allowed  to  subside.  This  part  of 
the  operation  lasts  twelve  hours  at  least ;  after  which,  the  soap,  still  hot,  becomes  alto- 
gether fluid  and  perfectly  neutral. 

For  every  1000  pounds  of  the  paste,  there  must  be  introduced  nine  pounds  of  essences, 
mingled  in  the  following  proportions: — six  pounds  of  essence  of  carui ;  one  and  a  half 
ditto  lavender,  (finest) ;  one  and  a  half  ditto  rosemary. 

The  mixture  must  be  well  stirred,  in  order  to  get  completely  saturated  with  the 
perfumes;  and  this  may  be  readily  done  without  at  all  touching  or  stirring  up  the 
subjacent  leys ;  m  the  course  of  two  hours,  the  soap  may  be  transferred  into  the  ordinary 
frames.  In  twenty-four  hours,  the  mass  is  usually  solidified  enough  for  cutting  into  bars 
and  cakes,  ready  to  be  stamped  for  sale. 

The  above  method  of  scenting  Windsor  soap  is  practised  only  in  the  largest  establish- 
ments ;  in  the  smaller,  the  soap  is  pailed  out  of  the  soap-pans,  into  a  pan  provided  with 
a  steam  case  or  jacket,  and  there  mixed  with  the  essential  oils,  by  means  of  appropriate 
beat  and  agitation. 

The  most  fashionable  toilet  soaps  are,  the  rose,  the  bouquety  the  cinnamon,  the  orange- 
flower,  the  musk,  and  the  bitter  almond  or  peach  blossom. 

Soap  d  la  rose. — This  is  made  of  the  following  ingredients :  30  pounds  of  olive-oil 
soap ;  20  of  good  tallow  soap. 

Toilet  soaps  must  be  reduced  to  thin  shavings,  by  zr/eans  of  a  plane,  with  its  undei 
face  turned  up,  so  that  the  bars  may  be  slid  along  it.  These  shavings  must  be  put  into 
an  unlinned  copper  pan,  which  is  ^rrounded  by  a  water-bath,  or  steam.  If  the  soap  be 
old  and  hard,  5  pounds  of  water  must  be  added  to  them ;  but  it  is  preferable  to  take 
fresh-made  soaps,  which  may  melt  without  addition,  as  soap  some  time  kept  does  not 
readily  form  a  homogeneous  paste.  The  fusion  is  commonly  completed  in  an  hour,  or 
thereby,  the  heat  being  applied  at  212°  F.,  to  accelerate  the  progress,  and  prevent  the 
dissolution  of  the  constituent  water  of  the  soap.  For  this  purpose  the  interior  pan  may 
be  covered.  Whenever  the  mass  is  sufficiently  liquefied,  1|  ounces  of  finely  groiad  ver- 
milion are  to  be  introduced,  and  thoroughly  mixed,  after  which  the  heal  may  be  taken 
off  the  pan ;  when  the  following  perfumes  may  be  added  with  due  trituration  :— 3  ounces 
of  essence  of  rose  ;  1  ditto  cloves ;  J  ditto  cinnamon  ;  2|  ditto  bergamot ;  =  7f . 

The  scented  soap  being  put  into  ihe  frames,  speedily  consolidates.  Some  recommend 
to  pass  the  finished  fused  soap  through  a  tammy  cloth,  in  order  to  free  it  from  all  clots 
and  impurities ;  a  very  proper  precaution  in  the  act  of  transferring  it  to  the  frame.  If 
the  preceding  instructions  be  observed,  we  obtain  a  soap  perfect  in  ever)'  point  of  view; 
possessing  a  delicious  fragrance,  equally  rich  and  agreeable,  a  beautiful  roseate  hue,  and 
the  softest  detergent  qualities,  which  keeping  cannot  impair.  Such  a  soap  has,  in  fact, 
been  known  to  retain  every  property  in  perfection  during  four  or  five  years.  When  the 
essential  oils  are  particularly  volatile,  they  should  not  be  added  to  the  soap  till  its  tem- 
perature has  fallen  to  about  140°  Fahr. ;  but  in  this  case  a  more  careful  trituration  is 
required.  The  economy  is,  however,  ill  bestowed  ;  for  the  cakes  made  of  such  cooler 
soap  are  never  so  homogeneous  and  glossy. 

^  Soap  au  bouquet. — 30  pounds  of  good  tallow  soap ;  4  ounces  of  essence  of  bergamot ; 
oil  of  cloves,  sassafras,  and  thyme,  1  ounce  each ;  neroli,  |  ounce.  The  color  is  given 
with  7  ounces  of  brown  ochre. 


672 


SOAP. 


SOAP. 


673 


Cinnamon  Soap. — 30  ponnds  of  good  tallow  soap ;  20  ditto  of  palm-oil  soap.  Per 
fumes: — 7  ounces  of  eseence  of  cinnamon;  1|  ditto  sassafras;  jj  ditto  bcrgamot. 
Color : — 1  pound  of  yellow  ochre. 

Orange-jlofwer  Soap. — 30  pounds  of  good  tallow  soap ;  20  ditto  palm-oil  soap.     Per 
ftimes :— 7|  ounces  essence  of  Portugal ;  7^  ditto  amber.     Color : — 9i  ounces,  consisting 
of  8J  of  a  yellow-green  pigment,  and  Ij  of  red  lead. 

Mtisk  Soap. — 30  pounds  of  good  tallow  soap  ;  20  ditto  palm-oil  soap.     Perfumes  : 

Powder  of  cloves,  of  pale  roses,  gilliflower,  each  4h  ounces ;  essence  of  bergamot,  and 
essence  of  musk,  each  3h  ounces.     Color : — 4  ounces  of  brown  ochre,  or  Spanish  brown. 

Bitter  Almxmd  Soap — Is  made  by  compounding,  with  60  pounds  of  the  best  white  soap, 
10  ounces  of  the  essence  ol  bitter  almonds. 

LIGHT  SOAPS. 

The  apparatus  employed  for  making  these  soaps  is  a  copper  pan,  heated  by  a  wateN 
bath ;  in  the  bottom  of  the  pan  there  is  a  step,  to  receive  the  lower  end  of  a  vertical  shaft, 
to  which  arms  or  paddles  are  attached,  for  producing  constant  agitation,  by  causing  them 
to  revolve  among  the  liquefied  mass.  Inio  a  pan  so  mounted,  50  pounds  of  good  oil  soap 
of  any  kind  are  put  (for  a  tallow  soap  does  not  become  frothy  enough),  and  melted  by 
proper  heat,  with  the  addition  of  3  or  4  pounds  of  water.  By  the  rapid  rotation  of  the 
machine,  an  abundant  thick  lather  is  produced,  beginning  first  at  the  bottom,  and  creep- 
ing gradually  upwards  to  the  top  of  the  pan,  when  the  operation  should  be  stopped  ;  the 
soap  having  by  this  time  doubled  its  volume.  It  must  now  be  pailed  off  into  the  frame, 
allowed  to  cool,  and  then  cut  into  cakes.  Such  soap  is  exceedingly  pleasant  at  the  wash- 
stand,  feeling  very  soft  upon  the  skin,  affording  a  copious  thick  lather,  and  dissolving 
with  the  greatest  ease. 

TRANSPARENT  SOAPS. 

These  soaps  were  for  a  long  time  manufactured  only  in  England,  where  the  process 
was  kept  a  profound  secret.    They  are  now  made  every  where. 

Equal  parts  of  tallow  soap,  made  perfectly  dry,  and  spirit  of  wine,  are  to  be  put  into 
a  copper  still,  which  is  plunged  in  a  water-bath,  and  furnished  with  its  capital  and 
refrigeratory.  The  heat  applied  to  effect  the  solution  should  be  as  slight  as  possible,  to 
avoid  evaporating  too  much  of  the  alcohol.  The  solution  being  effected,  must  be  suf- 
fered to  settle ;  and  after  a  few  hours*  repose,  the  clear  supernatant  liquid  is  drawn  off 
into  tin  frames,  of  the  form  desired  for  the  cakes  of  soap.  These  bars  do  not  acquire 
their  proper  degree  of  transparency  till  after  a  few  weeks'  exposure  to  dry  air.  They 
are  now  planed,  and  subjected  to  the  proper  mechanical  treatment  for  making  cakes  of 
any  form.  The  soap  is  colored  with  strong  alcoholic  solution  of  archil  for  the  rose  tint, 
and  of  turmeric  for  the  deep  yellow.  Transparent  soaps,  however  pleasing  to  the  eye. 
are  always  of  indifferent  quality ;  they  are  never  so  detergent  as  ordinary  soaps,  ana 
they  eventually  acquire  a  disagreeable  smell. 

Tlie  exports  of  soap  from  this  country  during  the  last  9  months,  (November  1862),  wen 
117,623  cwt.  against  99,983  cwt.  in  1851,  and  96,123  in  1850. 

The  following  is  an  invention  for  which  Dr.  Normandy  obtained  a  patent.  When 
yellow  soap  is  made  with  the  cheaper  kinds  of  fat,  tt  will  hardly  acquire  a  sufficient 
degree  of  firmness  or  hardness  to  satisfy  the  thrifty  washerwoman.  It  melts  away  too 
rapidly  in  hot  water ;  a  defect  which  may  be  well  remedied  by  the  introduction  into  the 
soap  of  a  little  fused  sulphate  of  soda ;  and  the  salt  concreting  gives  the  soap  a  desirable 
hardness,  while  it  improves  its  colour,  and  renders  it  a  more  economical  article  for  the 
washing-tub.  In  a  trial  recently  before  the  Court  of  Common  Pleas,  it  was  proved  that 
the  soap  made  according  to  Dr.  Normandy's  patent  was  worth  fully  21.  a  ton  more  than 
the  original  soap,  without  the  sulphate  of  soda. 

Soda-ash  is  the  substance  employed  in  the  manufacture  of  soap,  and  varies  in  the 
amount  of  soda  it  contains  to  the  extent  of  from  S§  to  50  per  cent,  according  to  the 
mode  of  its  formation.  A  small  quantity  of  this  soda  is  occasionally  in  the  caustic 
state  ;  but  the  great  bulk  is  combined  with  carbonic  acid,  as  carbonarte  of  soda,  and 
variable  proportions  of  chloride  of  sodium  and  sulphate  of  soda  exist  with  it  in  the 
soda  ash.  The  fabrication  of  soap  is  under  the  surveillance  of  the  excise,  and  conse- 
quently there  is  little  or  no  scope  for  improvement, — an  assertion  well  supported  by  the 
notorious  fact,  that  no  alteration  baa  taken  place  in  it  since  the  reign  of  Queen  Anne. 
Yet,  looking  upon  the  innumerable  changes  and  metamorphoses  which  the  fats  and  oils 
are  capable  of  undergoing  through  the  agency  of  chemistry,  there  is  no  subject  which 
offers  a-  fairer  field  for  the  labours  of  inventive  genius  than  this  very  manufacture. 
The  elements  united  together  in  the  class  of  animal  and  vegetable  oils  of  fats  are  not 
numerous,  but  seemingly  fitted  for  displaying  an  endless  mutability ;  and  no  doubt  the  day- 
will  come,  when,  from  perhaps  the  cheapest  and  most  worthless  of  these  substances,  we 
shall  be  able  to  form  every  other  variety,  or,  even  from  wood  and  coal  extract  substances 
of  this  kind  to  rival  and  supersede  tallow,  wax,  or  spermaceti.    At  present,  however,  tlie 


i. 


prmcipal  manufacturer  mterested  in  the  working  out  of  such  questions  lies  under  the 
inquisitorial  power  of  our  great  fiscal  harpy.  Improvement  under  such  an  influence 
loses  Its  reward;  for  concealment  is  impossible,  not  only  for  the  period  required  to  seal 
a  patent,  but  even  for  a  day  or  an  hour.  The  excise  officer  is  omnipotent  in  a  soap 
work,  for  he  carries  the  master  key  of  every  lock  on  the  premises :  all  must  open  wheh 
he  knocks :  all  must  explain  when  he  questions.  In  spite,  therefore,  of  the  thousands 
^.nf-T.r^  discoveries  which  have  been  made  within  the  last  twenty  years  in  depart- 
S!"  ^;^  ^'^  ""r^^^  *"'^^.***  soap-making,  this  manufacture  has  stood  still  for  more 
SjrH^^.r^"'  ?  ^'^'^"*'  9"^  "^""'^  remarkable  proofs  of  the  unwholesome  and  im- 
S^  M  t«  ir  <fe^<^^^  mterference.  Under  such  circumstances,  we  feel  almost  com- 
i^n^vil^nfr  w""?  ""T  Z-'T^^"^'''"^.  of  offering  a  few  remarks  in  the  direction  of 
IKm  of  T  .  ?"*'  u  ^^''  ^'"^T  *^  *^^  «>ap-™aker  like  the  water  bubbling  in 
down  hi  r  J  I  r  "'*^  ?\^"^  r""°^  ^"J^^'  *^^  V^^^^re^  boon,  for  he  is  tied 

hZ  »f  Th   !"TaP'^'''?^'^  ^"^  5?""^  ^''''  necessary  for  the  social  status  of  this  kinff- 

nZfll  hi  r  ^"T  ^T:  ^"I  '!r'^'  "P^"  *^«  ^»P  n^anufiicture  will  con^ 
quently  bear  no  proportion  whatever  to  the  importance  of  the  subject  or  to  the  position 

wS  LTV  ^''"T  *«Tr^''^  'f^""'^  /'"™  ^^^'-  restrictions:  the  L:un 
which  has  so  ong  restrained  the  wmg  of  invention  would  laugh  at  our  efforts  to  raise 
the  victim  of  his  oppression.  ^  "*'** 

In  this  department  of  industry,  improvement  has  therefore,  of  necessity    a  foreiffn 
origin  and  hence  we  regard  it  as  a  mere  matter  of  course  that  the  Exhibition  pr^ 

?nl„  iV.wV  T  f  fr  P^'"^  ':i^"  *^^  ^^"?'  ^^  ^°  American.  Mr.  John  Ransom  St 
John,  of  New  \  ork,  for  the  soap  made  under  whose  process  a  prize  medal  has  been  most 
justly  awarded,  has,  we  see,  secured  his  process  in  this  country  by  letters  patent  vet 
.t  will  not  surprise  us  m  the  least  to  find  that  Mr.  St.  John  is  prevented  brtheexcbe 
from  fol  owing  out  h.s  invention  here.  A  circumstance  exactly  parallel  to  this  assunintTon 
occurred  a  few  years  ago  to  another  foreigner,  Dr.  Normandy,  who  had  taken  oui 
patent  for  improvements  m  soap-making,  but  was  ruinously  in  erfered  with  and  u Iti 
mately  stopped  by  the  excise.  In  wishing  Mr.  St  John,  therefore,  all  tie  sucSe^  hb 
extremely  mgenious  invention  merits,  we  warn  him  that  he  may  yet  fal  b^nSth  ttie 
cnishmg  influence  of  the  Broad  Street  authorities  ^  ^  neneatn  the 

viously  spoken  of  is  mixe^d  with  an  amSunroTVe^lntTy^lTeXe  U^^^^^^^^^^ 
previously  ascertained  strength  of  the  soda-ash;  with^these  a  c^rtaTnTulHf  s^^^^^^^ 
generally  mixed,  for  the  purpose  of  facilitating  the  subsequent  process  of  fili^tl^ 
The  entire  mixture  is  now  placed,  layer  by  layer  in  a  tank  !imil^r  t^^K  .  5       -u  ",' 
for  lixiviating  the  ball-soda'^n  soda  iorkl  X^ayers  of  ^  L-  ^rJ^JlX 
layers  of  rush-matting  from  each  other,  and  a  plu-  l^inc.  driven  into  f»fa^!fwl       •«  ^ 
of  the  tank  this  lattef  is  filled  full  of  wkter  an/alfo^d  to  s"an3  frtwelve  oT  eiZt"^ 
hours.     The  plug  be  ng  then  withdrawn,  the  saturated  solution  of  cTustL  sodTflows 
down  into  a  reservoir  placed  beneath;  after  which,  the  plug  is  again  replS  mZl 
water  applied,  and  this  operation  is  repeated  five  or  six  times";  the  fariou"  iSsThu* 
obtained  being  conveyed  into  separate  reservoirs,  and  distinguished  from  eac2  other  by 
^e  names  first  running,  second  running,  and  so  on,  the  last  lling  of  course  tte  wSesf 
When  weak  soda-ash  is  employed  little  or  no  common  salt  need  be  addpd  f  n  Thfr^' 
ture  m  the  lime  vat;  but  when  soda-ash  of  great  stren-th  is  used  it  i,  np.if       f  ^^i 
a  considerable  quantity  of  common  salt  to  it  for  a  DurnosP  whtl^   '' "^^1^,7  *«  ^^ 
plained.    Having  in  this  way  produced  a  series  of  cSc  Ivis  of  dTi    'Y."^  ^  ^^Z 
strength,  the  weakest  is  pumped  up  into  a  b^i  er  cop^^asT^^^  ^T''  ""^ 

ally  made  of  cast-iron.  To  this  lye  a  quantity  of  tallow^««?^oi  5  .i  '^'  ^^^^J'  .^^"^'- 
some  time,  or  until,  upon  testing  it  tTeTe  is  fonnZn  ifi^  i'  ^"l*^^  ""^^^  ^'^^^  *"«' 
The  whole  is  now  klloVed  to  ccSl  and  remain  aUest  untU  tLT'  ''"  '*!J''^"-  n^/"^' 
alkali,  settles  to  the  bottom  of  the  copper  whence  ft  i.  n  Ln!J^^%"r  ^t^'T^  2^  '^ 
pump,  as  the  excise  regulations  do  noTpermitTto  t  wS^i^^^^^  "^.  ^^""^ 

other  countries,  from  the  bottom'  of  the  boiler  Thf,  fl„^f  ^T  ""  ?^1  ^  *'  **  ^^ 
and  contains  a  portion  of  glycerine  derived  from  ThL  f^f  \  ^f"«°""ated  spent  lye. 
flulphate  and  muViate  of  soda  of  he  soda-ash  and  In  .HWr  '  *f^^«^' *?g«*^«»'  ^^th  the 
soda  added  by  the  soap-maker.  Sie  presence  of  hi  *^,^'.*7*1  q"^"*'  y  of  muriate  of 
for  otherwise  the  taUow  and  lye  wouTd  Se  L  o  1  ^nf^^^^^  "^^  «  mdispensable, 
would  be  impossible  afterwards^toleparate  he  Slnt  Ive  h.^  T^^''^"'  ^T  ^.t'"^^* 
soluble  in  a  solution  of  common  salt  the  partialinlnJff^^^  '°*5  •'  '']^'^^^^^^  '^^ 

to  float  on  the  surface,  and  permits  of  th^e^Slv?nrl?^^  I*'"'  ^•■°"^*^* 

whence  as  we  have  seen  it  ia  n.Tna^  «        spent  lye  precipitating  to  the  bottom,  fron» 
wn^ce,  as  we  nave  seen,  it  is  pumped  away  and  lost,  being  of  no  value 

mive.  at  wbicU  the  grease  u'said  to^.^  "4^^»"^f  roThTloXfie  UlCt 

4« 


«74 


SOAP. 


•aponified,  or  combined  with  ite  full  equivalent  ot  soda.     This  point  is  well  known  to 
the  workmen  by  the  consjstence  of  the  compound,  when  a  little  of  it  is  squeezed  between 
the  finger  and  thumb  and  allowed  to  cool;  if  finished,  it  readily  separates  from  the  skin 
as  a  hard  cake  and,  moreover,  has  no  longer  the  taste  peculiar  to  grease ;  if,  on  the  con- 
trary, any  ^^l^/^^J^'" .  ^^«*P<>f  »fied,  this  oozes  out  by  the  pressure,  and  becomes 
perceptible  both  to  the  sight  and  taste.     A  more  certain  mode,  however,  is  to  decom- 
pose  a  portion  of  the  suspected  soap  by  means  of  an  acid,  and  ascertain  whether  the 
resultnig  grease  is  wholly  soluble  in  boihng  spirits  of  wine,  for,  if  not,  the  saponification 
has  been  imperfect.     Presummg,  however,  that  a  perfect  result  has  been  secured,  the 
soap  has  now  to  be  brought  into  a  marketable  condition,  and,  for  this  purposeTit  is 
fused  with  a  quantity  of  weak  lye  or  water.    So  soon  as  combination  lias  takeVplkce  a 
quantity  of  very  strong  lye  is  added,  until  an  incipient  separation  begins  to  show  itself 
The  heat  is  now  increased,  and  the  boiling  continued  for  a  considerable  time  the  mass 
being  prevented  from  boiling  out  of  the  vessel  by  workmen,  armed  with  shovels  who 
dash   the  soap  to   and  fro,  so  as  to   break  the  froth   upon   the   surface,  and   fkvour 
evapomtion.     At  first  the  soap  is  divided  into  an  innumerable  number  of  small  globules 
each  separate  and  distinct  from  its  fellow;  but,  as  the  boiling  goes  on,  those  graduallv' 
run  together  into  larger  and  larger  globules,  till  at  last  the  soap  is  seen  to  assume  a 
pasty  consistence,  and  to  unite  in  one  uniform  mass,  through  which   the  steam  from 
below  slowly  forces  its  way  in  a  series  of  bursts  or  little  explosions.     The  process  is  now 
tmished   and  all  that  remains  to  be  done  is  to  shut  down  the  Ud  of  the  copper,  havintr 
previously  extmguished  the  fire.     In  from  one  to  two  or  three  days,  accordincr  to  the 
nature  and  quantity  of  the  soap  in  question,  the  lid  is  again  raised,  and  tire  semifluid 
soap  ladled  from  the  precipitated  lye  by  means  of  ladles;  the  product  being  thrown 
into  a  wooden  or  iron  frame,  of  specific  dimensions,  where  its  weight  is  estimated  by 
measurement,  and  the  duty  charged  upon  it.    In  making  common  yellow  or  resin  soap, 
the  resm  is  usually  added  after  the  saponification  of  the  tallow,  in  the  proportion  of  on4- 
third  or  one-fourth  of  the  tallow  employed.     The  subsequent  operations   are   much 
about  the  same  as  those  above  described ;  but,  in  addition,  just  before  closing  the  lid  of 
^e  copper,  a  quantity  of  water  or  weak  lye  is  sprinkled  over  the  melted  soap,  which 
carries  down  with  it  the  mechanical  impurities  of  the  resin ;  and  these  constitute  a  dark 
layer  of  soap  restmg  upon  the  lye,  which  is  not  poured  into  the  frame  with  the  rest,  but 
18  placed  apart  under  the  name  "  nigerr  and  brings  a  less  price.     Good  curd  or  white 
soap  should  cont^n  of  or  «  w  >»*"»« 


Orease 

Soda 

Water 


or  consist  of 


Grease  acid 
Soda 
Water    - 


-  61*0  parts 

6-2      " 

-  32-8     •* 

100 

1  atom=816 

1  atom=  32 

17  atom8=153 


Resin  soap  has  a  more  variable  composiUon,  but,  when  not  adulterated  with  water 
•nould  contain  about  as  follows : — 


Grease  and  resin 

Soda 

Water 


60 
84 

100 


^e  manufacture  of  soft  soap  differs  greatly  from  that  of  hard  soap;  as,  in  this  case 

Snd  3'' ^'P"' T^  ^'•^'^  t^^™''^^"--?  i«  tl^e  boiler;  and  the  alkali  employed  is  IS] 
and  not  soda.  The  mode  of  obtaining  a  caustic  lye  of  potash  is  exActfy  the  simc  as 
with  soda,  except  that  the  weak  lyes  are  used  in  place  of  water  for  V  subTequeSJ 
operation,  and  not  pumped  up  into  the  boiler.  The  materials  employed  as  fats  a?e 
mixturesofthe  vegetable  and  animal  oils,  as  rape,  and  the  fish-oil  ^lled  "Southern  " 
For  the  best  kinds  of  soft  soap,  a  little  tallow  is  added  to  these,  which  prXces  a 
S^n  ft'  Thlf  T^'^'1^  ^^  crystallization  in  the  soap,  that  conf;rs  add itfonal  value 
upon  It.  These  oils  or  fats  are  merely  boiled  with  the  strong  caustic  potash-lye,  until 
thorough  combination  has  taken  place,  and  so  much  of  the  watir  of  the  lye  is  evaporated, 
that,  when  a  portion  of  the  soap  is  poured  upon  a  cold  slab,  and  allowed  to  rekt  for  a 
few  mmutes,  it  assumes  the  consistence  of  soft  butter.  As  soon  as  this  happens,  the 
whole  is  run  out  into  little  casks,  where  it  cools;  and  is  thus  sent  into  the  market.  Of 
course  no  atomic  arrangement  can  be  traced  in  so  variable  a  compound;  and  hence  iU 


SOAP. 


675 


mni^fnJ'I^nrr  "W'"a*'C'"'***'^'*-  ^^  employment  of  soft  soap  is  daily  becoming 
more  and  more  bmited.    Soft  soap  usually  contains  as  under  ^ 

Fatty  oils        -  -  .  .  -      48 

Potash  -  .  .  .  -      10 

Water  -  .  .  .  -     47 

bat  its  composition  differs  greatly. 

fatfv  3V^i  W^^'^i^iir^t  PTr'^  '°  ^  P?*^"*  &'^°*«^  »»  1845  to  make  soap  from 
wSe  otl  arc  nuf  fnl^^"'^^^^  ™'*"'  of  sulphuric  acid.  10  tons  of  palm  oil  or 
wnaie  oil  are  put  into  a  wrought-iron  vessel  provided  with  a  perforated  steam  worm- 
through  which  steam  is  admitted  till  the  temperature  rises  to  350^  F     the  ili^Z^^r 

¥he  tanr?i.'s?st\*""'-'""'^  of  brick  lined  with  lead  and  sunkt  the^^ou"d 
Ihe  tank  has  a  steam  pipe  inserted  into  it,  and  has  a  wooden  cover  lined  with  lead, 
having  two  manholes  in  it.  It  is  closed  by  an  oil  joint  about  8  inches  deen  Thro^h 
the  c^ver  a  pme  passes  connected  with  a  high  shaft  for  the  escape  of  offensWe  vaSs 
and  their  concfensation  by  a  jet  of  cold  water.  2000  lbs.  of  sulfuric  acifof  18  s^E^^^^ 
gravity  are  poured  into  the  tank ;  the  temoerature  of  the  mas^s  b^rng  meaLwhili^^ 
fully  watched  hj  a  thermometer  and  not  allowed  to  exceed  SSO^  pihl  TTe  admis^c^ 
of  steam  IS  continued  wh.le  the  acid  is  being  slowly  poured  in.  When  this  is  do"e  thS 
fire  IS  extinguished  But  steam  is  admitted  for  4  hmiVs  afterwards  King  heated  btwy 
by  passing  through  pipes  placed  over  a  ^re.  The  steam  being  stopped,  and  the  mai 
somewhat  cooled,  a  large  pump  is  introduced,  and  the  product  is^  turned  out  into^ 
wooden  vessel  lined  with  lead  and  provided  with  a  steam  worm.  In  thrveLlthe  f^ttv 
Tpn  l/'  T^"*  by  n^eans  of  free  steam  with  half  its  bulk  of  water  f^  2  h^irs  an^^^^^ 
then  allowed  to  rest  for  12  hours.  The  product  thus  obtained  can  be  made  into  Un  b 
the  ordinary  way ;  but  it  is  better  to  distil  it  first    See  Fat  ^ 

*r«X'^o^T-^'^'i"'^  ''^'^'''^^'f  ^  our  E^ise  LarcH.-ln  1831,  the  candle  makine 
trade  was,  after  a  long  reign  of  oppression,  emancipated  from  the  odious  exc^  hTrpies^ 
and,  says  the  patno  ic  Mr.  G.  F.  Wilson,  "those  only  know  their  crai^pfng  inflTen« 
who  have  worked  under  them.  Our  neighbour  trade,  soap  making,  sho^'^^ts  in?urv  b^ 
he  fiict  that  the  German  soap  makers  are  so  far  in  advance  of  oufi  thai  theVbiy  from 

cha  rs^'tile  En"Lh  «t^^  '"'1; '"  ^^'V^^l  V^^  freight,  commission^aid^the" 
cnarges.  while  English  soap   makers  cannot   use  it,  though   at   their  own    doors.     Tn 

HerpTh^TP  ^^'•^f^^ol^^^cid  forms  a  part  of  llmost  every  ste^icTndtfectory 
Here  the  nuisance  of  being  subject  to  fixed  times  and  rules  of  work,  and  to  prvinriJ' 
cisemen  m  most  cases  prevents  the  business."- On  ^A.  Stearic  CalkMLu}J^reLG 
^iS^'  ^c^?;\^ZT'^J^''''^^''^  ^fP^^^^'^  Candle  Company.     1852.      ^  ^ 

SOAPS  QUALITY  OF.  To  determine  the  quantity  of  water,  thin  slices  are  cut 
from  the  edges  and  from  the  centre  of  the  bars.  A  portion  is  then  weig^^^^^^^ 
6  grammes  (60  o  70  gmins),  and  exposed  to  a  curre^of  air  heated  t^  212-' Fahr  or  k 
J^if  bath^^ntil  It  ceases  to  lose  weight  Tlie  dry  substance  is  then  weLhed  X 
difference  between  che  first  and  last  weighing  will  indicate  the  quantity  of  wafer  e;a^ 
rated  If  it  be  a  soft  soap,  it  is  weighed  in  a  counterpoised  shallow  ^psuTeln^ 
^Xll  ;"rrnt.°'  "^'^''  ^"^^^  ''•^'^  ''  "-  ''  P-  -'^'  -  -ottled  anTsoft'oa';^  gS^ 

The  purity  of  soap  may  be  ascertained  by  treating  it  with  hot  alcohol-  if  the  soan  b« 
wh  e  and  without  admixture,  the  portion  Remaining  undissolved  is  verV  m^nte  aL  a 
mottle  soap  of  good  quality  does  not  leave,  when  oLratinHn  5  ^aLZs  Z^'thnn  S 
centigrammes,  or  about  1  per  cent  i^i«tiiig  ou  o  grammes,  more  than  5 

If  there  should  be  a  sensible  amount  of  residue  from  white  soap,  or  more  than  1  n*.r 
cent  from  mottled  soap,  some  accidental  or  fraudulent  admixtur^e  may  b^  su^ecSi 
^^naTyst""''  '''^*"^'  *"'*'^  ^"^"^^^^  ^"^  ^^^^  ^'  ^^^^  m"7be''d:Sfned 

alkdLt"'^'^  '^  '^^'^^  '''*"^"^^  ^°  '^'  ««*P  ^«  ^^y  d-^-^^i^ed  by  means  of  the 

10  grammes  in  thin  slices  are  taken,  for  instance,  and  dissolved  in  150  grammes  of 
boiling  water  •,  and  this  solut  on  is  saturated  with  a  normal  M^.Z^  !.^J-  e^*°**°^®  of 
of  water  100  grammes  of  sulphuric  JtdXecTiTsl^Tv^^^^^  *°  f'  ^T' 

Tl.  volume  of  this  l^uor^equired  fo~lft""^^^^^ 

T^r^lrZte  I'f'X'"'''  ^^^  ^'^^'  ''  ''''^'  ^^^^  ^^^^^^  ^o  ^i^^ulS  wTigh^ 

The  quantity^  pure  potash  or  soda  may  be  thus  deduced. 

There  is  no  difficulty  m  ascertaining  in  the  same  assay  the  quantity  of  the  fatty  sub- 
stance.     For  this  purpose  10  grammes  of  pure  white  wax  free  from  water  are  adJed  to 
hiT-l  •  ^1!"  '^%'^''^:^  r'^  sulphuric  acid,  and  the  whole  heated  to  completrHque 
faction :  it  is  then  allowed  to  cool,  and  when  it  has  become  solid,  the  cake  of  wlx  ^^d 


676 


SODA. 


fatty  matter  -which  have  united  is  removed,  and  "washed,  dried  and  weighed ;  the 
augmentation  in  weight  beyond  the  10  grammes  employed  will  give  the  weight  of 
the  fatty  matter. 

The  liquid  decanted  from  the  solidified  wax  may  afterwards  be  tested,  to  ascertain  the 
purity  of  the  base. 

The  solution  of  the  sulphate  may  also  be  evaporated,  and,  by  an  examination  of  ita 
crystalline  form,  or  by  means  of  chloride  of  platinum,  it  may  be  ascertained  whether  the 
base  be  soda  or  potash,  or  a  mixture  of  the  two. 

As  to  the  nature  of  the  fatty  substance,  it  is  ascertained  with  more  or  less  certainty, 
by  saturating  the  solution  of  the  soap  with  tartaric  acid,  collecting  the  fat  acids,  and 
taking  their  point  of  fusioa  It  is  possible,  at  least,  by  this  to  prove  the  identity  or  the 
absence  of  identity  with  the  sample  in  the  soap  supplied ;  for  instance,  whether  it  is  made 
from  oil  or  tallow,  <fec.  The  odour  developed  by  the  fatty  matter  at  the  moment  of  the 
decomposition  of  the  soap  by  acids  assisted  by  heat  will  often  indicate  the  nature  of  the 
fatty  substance  employed  in  its  fabrication,  or  that  at  least  of  which  the  odour  may 
prevail. 

The  soap  is  proved  to  contain  an  excess  of  fatty  matter  not  saponified,  by  separating 
the  fatty  acids  by  means  of  hydrochloric  acid,  washing  with  hot  distilled  water,  thea 
combining  them  with  baryta  and  thoroughly  washing  the  new  compound  with  boiling 
water.  The  nonsaponified  fatty  matter  is  easily  separated  from  the  barytic  soap  by 
treating  the  mass  with  boiling  alcohol,  which  dissolves  the  fatty  substance.  We  can 
moreover  assure  ourselves  that  it  has  no  acid  reaction  on  moistened  litmus  paper,  that  it 
is  fusible,  and  that  it  possesses  the  general  character  of  a  neutral  fatty  substance. 

SOAPSTONE ;  see  Steatite. 

SODA,  Caustic  soda  {Hydrate  de  sonde,  Fr. ;  jSetznairon,  Genn.)>  is  an  alkaline  sub 
StEQce,  used  in  chemical  researches,  in  bleachine,  and  in  the  manufacture  of  soap.  It  i^ 
prepared  by  boiling  a  solution  of  crystallized  carbonate  of  soda  in  4  or  5  parts  of  water, 
with  half  its  weight  of  recently  slaked  and  sifted  lime.  At  the  end  of  half  an  hour,  the 
Tessel  of  iron,  porcelain,  or  preferably  silver,  may  be  removed  from  the  fire,  and  covered 
carefully,  till  the  calcareous  matter  has  settled  into  a  solid  magma  at  the  bottom.  The 
clear  supernatant  ley  may  be  then  decanted  into  bottles  for  use  in  the  liquid  state,  or 
evaporated,  out  of  contact  of  air,  till  it  assumes  an  oily  appearance,  then  poured  upon 
an  iron  or  marble  slab,  broken  into  pieces,  and  put  up  in  vials  secured  with  greased  stop- 
pers or  corks. 

Caustic  soda  is  a  white  brittle  mass,  of  a  fibrous  texture,  a  specific  gravity  of  1*536, 
melting  at  a  heat  under  redness,  having  a  most  corrosive  taste  and  action  upon  animal 
matters,  dissolving  readily  in  both  water  and  alcohol,  attracting  carbonic  acid  when 
exposed  to  the  atmosphere,  but  hardly  any  water,  and  falling  thereby  into  an  eflaorescent 
carbonate ;  it  forms  soaps  with  tallow,  oils,  wax,  rosin  ;  dissolves  wool,  hair,  silk,  horn, 
alumina,  silica,  sulphur,  and  some  metallic  sulphurets.  It  consists  of  77*66  soda,  and 
22*34  water.  A  solution  of  caustic  soda  affords  no  precipitate  with  solution  of  chloride 
of  platinum,  or  tartaric  acid,  as  a  solution  of  caustic  potash  never  fails  to  do. 

The  following  Table  of  the  quantity  of  Caustic  Soda  contained  in  Leys  of  different 
densities,  has  been  given  by  Richter : — 


1      Spec. 

Soda 

Spec. 

Soda 

Spec. 

Soda 

Spec. 

Soda 

grav. 

per  ceut. 

grav. 

per  cent. 

grav. 

per  cent. 

giav. 

per  cent. 

1*00 

0-00 

1*12 

11-10 

1*22 

20*66 

1*32 

29*96 

1*02 

2-07 

1*14 

12*81 

1*24 

22*58 

1-34 

31*67 

1«04 

4*02 

1*]6 

14*73 

1*26 

24*47 

1*35 

32*40 

1-06 

6*89 

M8 

16*73 

1*28 

26*33 

1-36 

33-08 

1*08 

7*69 

1-20 

18-71 

1*30 

28*16 

1*38 

34*41 

MO 

9-43 

Soda  free  from  water  can  be  obtained  only  by  the  combustion  of  sodium,  which  see. 

On  the  30th  of  June,  1838,  Messrs.  Dyars  and  Hemmings  obtained  a  patent  for 
manufacturing  soda  by  the  decomposition  of  sea-salt  with  sesquicarbt^nate  or  bicarbonate 
of  ammonia.  Equal  parts  of  the  chloride  of  sodium  and  sesquicarbonate  are  pres- 
cribed, being  very  nearly  the  equivalent  decomposing  proportions,  and  the  ammonia 
salt  is  recommended  to  be  added  in  powder  to  a  saturated  solution  of  the  sea  salt,  and 
the  mixture  to  be  stirred,  and  then  set  aside  till  the  mutual  action  and  decomposition 
be  effected.  Having  been  employed  to  examine  this  process  for  a  gentleman  who 
wished  to  adopt  it  on  a  manufacturing  scale,  I  obtained   tlic  following  results.      On 


SODA. 


677 


^r 


-r 


making  the  prescribed  mixture  in  the  cold,  brisk  effervescence  takes  place,  because 
the  quantitv  of  carbonic  acid  combined  with  the  ammonia  is  greater  than  the  resulting 
soda  can  readily  absorb,  even  to  form  its  bicarbonate,  and  this  extrication  of  gas  carries 
off  with  it  more  or  less  ammonia,  amounting,  in  carefully  conducted  experiments,  to  no 
less  than  27  per  cent,  of  the  sesqui-carbonate  employed ;  though  the  magma  deposited 
from  the  mixture  was  drained  in  vessels  nearly  close,  and  though  the  ammonia  which 
adhered  to  it,  as  well  as  that  in  the  drained  mother  liquors,  was  recovered  by  distilla* 
tion  in  vessels  connected  with  aWoulfe's  apparatus.  Moreover,  the  utmost  amount  of 
soda-ash  (not  pure  carbonate)  which  was  obtained,  was  only  37*5  for  100  of  sea  salt 
used,  whereas  90  of  carbonate  should  result  from  100  of  the  sea  salt,  with  the  above 
equivalent  dose  of  sesqui-carbonate  of  ammonia.  This  latter  salt  contains  about  one 
^  half  more  carbonic  acid  than  is  required  by  the  soda  to  become  a  carbonate.  A  good 
illustration  of  the  loss  of  ammonia  in  a  similar  case  is  afforded  by  the  decomposition  of 
chloride  of  calcium  in  solution,  by  adding  to  it  the  equivalent  dose  of  pulverized 
ammonia  carbonate  ;  viz.,  56  of  the  former  and  59  of  the  latter.  The  rapid  extrication 
of  the  carbonic  acid  on  making  this  mixture,  causes  such  a  waste  of  ammonia,  that 
more  of  the  sesqui-carbonate  must  be  afterward  introduced,  to  complete  the  decompo- 
sition of  the  chloride ;  the  stronger  the  solution  of  the  chloride  the  greater  is  the  loss 
of  ammonia. 

In  one  of  my  experiments  where  were  employed  3500  grains  =half  a  pound  avoir 
dupois,  of  each  ingredient,  the  following  were  the  products  : — 


1.  Ammonia  recovered  by  distillation  from  the  drained  magma, 

equivalent  in  sesqui-carbonate  to        -        -        -        -        - 

2.  Ammonia  as  carbonate,  from  the  remaining  liquid,  sucked  into  a 

vacuous  apparatus  and  distilled  -        -        -        -        - 

3.  Additional  ammonia  as  carbonate,  obtained  from  the  cold  mother 

liquors,  by  distillation  with  quicklime,  and  out  of  the  sal 
ammoniac  formed      -------- 


Grains. 
257 

1509 


Sesqui  carbonate  employed 


775 

2541 
3500 


4 


Loss  ....        -        959 

or  27-4  per  cent. 

The  product  from  this  experiment  in  dry  soda  ash  was  only  1500  grains,  which  were 
found  to  contain  only  1312  of  pure  carbonate,  or  87*6  per  cent,  of  the  whole.  Here  is 
a  deficiency  of  soda  carbonate,  upon  the  quantity  of  the  chloride  used,  of  no  less  than 
68^  per  cent,  for  only  1312  grains  are  obtained  instead  of  3150. 

Subsequently  a  method  occurred  to  me,  whereby  this  process,  elegant  in  a  scientific 
point  of  view,  might  possibly  be  executed  with  advantage  upon  the  commercial  scale ; 
out  it  would  require  a  very  peculiar  apparatus,  though  not  nearly  so  costly  as  what  was 
erected  by  Mr.  Cooper,  under  the  direction  of  the  patentees,  at  Battersea  and  in  Brussels. 

SODA,  CARBONATE  OF  {Kohlemaures  natron^  Germ.) ;  is  the  soda  of  commerce 
in  various  states,  either  crystallized,  in  lumps,  or  in  a  crude  powder  called  soda-ash.  It 
exists  in  small  quantities  in  certain  mineral  waters ;  as,  for  example,  in  those  of  Seltzer, 
Seydschutz,  Carlsbad,  and  the  volcanic  springs  of  Iceland,  especially  the  Geyser ;  it  fre- 
quently occurs  as  an  efflorescence  in  slender  needles  upon  damp  walls,  being  produced 
by  the  action  of  the  lime  upon  the  sea  salt  present  in  the  mortar.  The  mineral  soda  is 
the  sesquicarbonate,  to  be  afterwards  described. 

Of  manufactured  soda,  the  variety  most  antiently  known  is  barilla,  the  incinerated 
ash  of  the  Sahola  soda.  This  plant  is  cultivated  with  great  care  by  the  Spaniards, 
especially  in  the  vicinity  of  Alicant  The  seed  is  sown  in  light  low  soils,  which  are 
embanked  towards  the  sea  shore,  and  furnished  with  sluices,  for  admitting  an  occasional 
overflow  of  salt  water.  When  tlie  plants  are  ripe,  the  crop  is  cut  down  and  dried  ;  the 
seeds  are  rubbed  out  and  preserved  ;  the  rest  of  the  plant  is  burned  in  rude  furnaces,  at 
a  temperature  just  sufficient  to  cause  the  ashes  to  enter  into  a  state  of  semi-fusion,  so 
as  to  concrete  on  cooling  into  cellular  masses  moderately  compact.  The  most  valuable 
variety  of  this  article  is  called  sweet  barilla.  It  has  a  grayish-blue  colour,  and  gets 
covered  with  a  saline  efflorescence  when  exposed  for  some  time  to  the  air.  It  is  hard 
and  difficult  to  break  ;  when  applied  to  the  tongue,  it  excites  a  pungent  alkaline  taste. 

I  have  analysed  many  varieties  of  barilla.     Their  average  quantity  of  free  or  alkali- 
metrical  soda  is  about  17  per  cent;    though   several    con  tarn   only  14   parts  in    the 
hundred,  and  a  few  upwards  of   20.      This  soda  is  chiefly  a  carbonate,  with  a  little 
Bulphuret  and  sulphate ;  and  is  mixed  with  sulphate  and  muriate  of  soda,  carbonate  of 
lime,  vegetable  carbon,  Ac. 


678 


SODA. 


SODA. 


«rf 


Another  mode  of  manufacturing  crude  soda  is  by  burning  sea- weed  into  kelp.  For 
merly  very  large  revenues  were  derived  by  the  proprietors  of  the  shores  of  the  Scottish 
islands  and  Highlands^  from  the  incineration  of  sea-weed  by  their  tenants,  who  usually 
paid  tlieir  rents  in  kelp;  but  since  the  tax  has  been  taken  off  salt,  and  the  manufactur* 
of  a  crude  soda  from  it  has  been  generally  established,  the  price  of  kelp  has  fallen 
extremely  low. 

The  crystals  of  soda-carbonate,  as  well  as  the  soda-ash  of  British  commerce,  are  now 
made  altogether  by  the  decomposition  of  sea-salt. 

SODA  MANUFACTURE. 

The  manufacture  divides  itself  into  three  branches : — 1.  The  conversion  of  sea  sail 
or  chloride  of  sodium,  into  sulphate  of  soda.    2.  The  decomposition  of  this  sulphate  into 
crude  soda,  called  black  balls  by  the  workmen.    3.  The  purification  of  these  balls  either 
into  a  dry  while  soda-ash  or  into  crystals.  ' 

1.  The  preparation  of  the  sulphate  of  aoda.—Figs.  1311,  1312,  1313,  represent  the 
furnace  for  converting  the  muriate  of  soda  into  the  sulphate.  The  furnace  must  be 
built  interiorly  of  the  most  refractory  fire-bricks,  such  as  are  used  for  glasshouses,  but 
of  the  ordinary  brick  size ;  except  the  bridges  c,  g,  n,  which  should  be  formed  of  one 
mass,  such  as  what  is  called  a  Welsh  lump,  a  is  the  ash-pit ;  b,  the  grate ;  c  the 
first  bridge,  between  the  fire  and  the  first  calcining  hearth  d,  d  ;  f,  f,  is  its  roof;'  g'  the 
second  bridge,  between  the  calcining  hearth  and  the  decomposing  hearth  i,  i,*  i ; '  the 
roof  of  which  is  k,  k.  This  hearth  i,  i,  is  lined  with  a  lead  square  pan,  5  or  6  inches 
deep,  sloped  at  the  back  opening,  in  fig.  1313,  marked  m';  which  deficient  part  of  the 
upright  side  is  filled  up  with  two  bricks  placed  one  over  the  other,  as  shown  at  m,  m 
fig.  1312,  and  luted  with  clay,  to  confine  the  semi-liquid  mass  in  the  pan,  i,  i.  Some 
manufacturers  make  this  pan  8  inches  deep,  and  hne  its  bottom  and  sides  with  bricks 
"^  or    silicious    sandstone,   to    protect    the 

lead  from  the  corrosive  action  of  the 
acid.  There  are  others  who  consider 
this  precaution  troublesome,  as  the 
points  of  the  pan  which  become  leaky 
are  thereby  concealed.  In  the  roof  of 
the  decomposing  hearth,  one  or  two 
syphon  funnels  r,  of  lead,  are  in- 
serted when  the  charge  of  acid  (sul- 
phuric)  is    to    be    poured    down    upon 

— — ;; s ^^^  ^^'*  ^^  '»  '» to  save  the  risk  of  any 

annoyance  from  the  fumes  of  the  muriatic  acid,     o,  o,  is  a  chimney  filled  with  round 
flint  nodules,  which  are  kept  continually  moist  by  the  trickling  of  a  streamlet  of  water 

upon  the  topmost  layer.  The  muriatic  gas, 
meeting  this  descending  film  of  water  upon 
so  extensive  a  surface,  becomes  absorbed,  and 
runs  out  below  in  a  liquid  form.  When  the 
acid  is  required  in  a  somewhat  concentrated 
state,  this  chimney  should  be  made  both  high 
and  capacious.  Such  a  plan,  moreover,  is 
very  valuable  for  abating  the  nuisance  caused 
by  the  disengagement  of  the  muriatic  acid 


■^ 


1812 


M 


El 


_ 


gas;  which  is  otherwise  apt  to  sterilize  the  surrounding  vegetation 

A  fire  being  kindled  in  the  grate  B,figs.  1311.  and  1312,  3  cwts.  of  salt  in  powder 
are  to  be  thrown  by  a  shovel  into  the  pan  i,  through  the  door  M,fig.  1813,  or  m.m  fig 
1312.  Two  hundred  weights  and  a  half  of  oil  of  vitriol,  of  specific  gravity  1-844  havini 
been  diluted  with  from  25  to  30  per  cent,  of  water,  and  well  mixed,  or  3  cwts.  at  56^ 
Baume,  are  to  be  slowly  poured  in  by  the  funnel,  and  diffused  among  the  muriate  of 
soda,  by  an  occasional  stir  with  an  iron  rake  cased  with  sheet  lead.  Fumes  of  muriatic 
acid  will  now  plentifully  escape,  and,  passing  up  the  condensing-shaft  o,  will  flow  down 
.n  the  form  of  hquid  spirit  of  salt,  and  escape  by  the  stoneware  stopcock  p,  mto  tlie 
pipe  of  a  sunk  cistern.  The  fire  having  been  steadily  kept  up  at  a  moderate  degree,  the 
chemical  reaction  wdl  be  tolerably  complete  in  the  course  of  two  hours ;  but  as  this  is 
relative  to  the  nature  of  the  fuel,  and  the  draught  of  the  furnace,  no  very  precise  rule 
in  point  of  time  can  be  laid  down ;  but  it  is  sufficient  for  this  stage  of  the  process  when 
the  fumes  cease  to  be  very  dense  and  copious,  as  may  be  ascertained  by  opening  the  door 
M,  and  looking  in,  or  by  the  appearance  at  the  lop  of  the  shaft  o.  Over  the  door  m'  in 
the  opposite  side  of  the  decomposing  hearth, /ig.  1313,  there  must  be  an  arch  or  hood 
terminating  in  a  small  chimney,  15  or  20  feet  high,  for  the  ascent  of  the  muriatic  vapors. 


'' 


i 


1313 


Ol    .'fr    ,5|    ,    ,    ,    ,^P 


1.5 .   .  -f'tajo 


1314 


when  the  charge  Is  drawn  or  mn  out  of  the  hearth,  and  allowed  to  fall  into  a  «innre 
shallow  iron  tray,  placed  on  the  ground  at  the  back  of  the  furnace,  /or  this  discharge, 
the  two  bricks  which  serve  as  stoppers  to  that  orifice,  must  be  unluted  and  r^emovea. 

As  soon  as  that  charge  is  taken  out,  (the  fire  being  meanwhile  checked  by  opening 
the  door  T,fig.  1312,  and  shutting  partially  the  ash-pit  opening  at  a,)  a  Iresh  charge 
must  be  introduced  as  above  described.  The  nearly  decomposed  saline  matter,  during 
the  second  charging  of  the  hearth  i,  will  have  grown  cool  and  concrete.  It  must  be 
shovelled  into  the  calcining  hearth  d,  D.fig.  1311,  by  the  back  door  Q,;ig.  1813,  where 
it  will  receive  a  higher  degree  of  heat;    and,  by  the  expulsion  of  the  remaining  part  ot 

the  muriatic  acid,  it  will  become  a 
perfect  sulphate  of  soda.  It  should 
be  finally  brought  into  a  state  of  semi- 
fusion.  When  a  sample  of  it,  taken 
out  on  \he  end  of  the  rake  or  trowel- 
shaped  scraper,  emits  no  fumes,  the  con- 
version is  accomplished. 
From  3  cwts.  of  common  salt,  or  mu- 

,   ,  1   ,  1^1   I  V  T'|o        riate  of  soda,  rather  more  than  3i  cwts. 

of  perfect  sulphate  should  be  obtained,  quite  free  Uvm  metallic  impurity. 
The  next  step  is  the  conversion  of  the  sulphate  into  a  crude  soda. 
One  of  the  most  improved  soda  furnaces  is  that  employed  in  a  few  factories,  repre- 
sented in  figf.  1314, 1316,  and  1316.  In  the  section  fig.  1315,  there  are  two  hearths 
in  one  furnace,  the  one  elevated  above  the  level  of  the  other  by  the  thickness  of  a  brick, 
or  about  3  inches,  a  is  the  preparatory  shelf,  where  the  mixture  to  be  decomposed  is 
first  laid  in  order  to  be  thoroughly  heated,  so  that  when  transferred  to  the  lower  or 
decomposing  hearth  b,  it  may  not  essentially  chill  it,  and  throw  back  the  operation. 

c  is  the  fire-bridge,  and  d  is  the  grate. 
In   the  horizontal   section,  or  ground 
plan, /ig.  1316,  we  see  an  opening  in 
the  front  corresponding  to  each  hearth. 
This   is  a  door,  as  shown  in  the  side 
view    or    elevation    of    the    furnace, 
fig.   1314;   and  each  door  is  shut  by 
an   iron   square   frame    filled    with    a 
fire-tile    or    bricks,    and     suspended 
by    a  chain   over    a  pulley    fixed    in 
any  convenient   place.     See  Pitcoal, 
COKING  OF,  p.    1047.     The   workman, 
on     pushing     up     the     door      lightly, 
makes  it  rise,  because  there  is  a  coun- 
terweight at    the   other   end   of  each 
chain,  which  balances  the  weight  of  the 
frame  and  bricks.     In  the  ground  plan, 
only  one    smoke-flue    is   shown;    and 
this  construction   is  preferred  by  many 
manufacturers ;    bat   others  choose    to 
have  two  flues,  one  from  each  shoulder, 
as  at  a,  6 ;  which  two  flues  afterwards 
unite   in   one    vertical  chimney,  from 
25  to  40  feet  high  ;  because  the  draught 
of  a  soda-furnace  must  be  very  sharp. 
Having     sufliciently      explained      the 
construction     of    this     improved    fur- 
nace, I  shall  now  proceed  to  describe 
the  mode  of  makin?  soda  with  it. 


I 


xi: 


L 


III 


I 


^ 


£ESE 


I       1 I L 


J L 


*■*>   ^^t. 


The  materials  with  which  the  sulphate  is  decomposed  into  a  rough  carbonate  of  soda, 
are  chalk  or  ground  limestone,  and  ground  coal  or  charcoal.  The  proportions  in  which 
these  three  substances  are  mixed,  influence  in  a  remarkable  degree  the  success  of  the 
dfccomposing  process.  I  have  known  a  lalse  proportion  introauced,  and  persevered  in, 
at  a  factory,  with  the  most  prejudicial  effect  to  the  product;  the  soda-ash  produced  being 
in  a  small  quantity  relatively  to  the  sulphate  employed,  and  being  much  charged  with 
sulphur.  After  very  numerous  trials  which  I  have  made  on  the  great  scale,  anu  many 
in(|uiries  at  the  most  successful  soda-woi-ks,  both  in  this  country  and  abroad,  I  am  war- 
ranted to  offer  the  following  pro|)ortions  as  the  most  profitable  : — 

Sulphate  of  soda,  100  parts;  carbonate  of  lime  (chalk  or  limestone),  from  110  to  120 
parts;  if  pure,  110;  if  a  little  impure  or  ilanip,  120;  pitcoal,  50  oarts. 


li    I 


1 


680 


SODA. 


These  materials  must  be  separately  ground  by  an  edge-stone  mill,  and  siAed  into  • 
tolerably  fine  powder.  They  must  be  then  very  carefully  mixed.  Attention  to  these  par- 
ticulars is  of  no  little  importance  to  the  success  of  the  soda  process. 

One  hundred  parts  or  pounds  of  sulphate  of  soda  are  equivalent  to  75  parts  of  car- 
bonate, and  when  skilfully  decomposed,  will  generally  yield  fully  70  pounds.  A  charge 
for  the  decomposing;  furnace  with  the  preparatory  shelf  should  not  exceed  200  lbs.  or 
perhaps  180 ;  therefore  if  75  pounds  of  ground  sulphate  of  soda,  with  80  pounds  of  chalk 
or  limestone  (ground),  and  37  pounds  of  ground  coal,  be  well  mixed,  they  will  constitute 
one  charge.  This  charge  must  be  shovelled  in  upon  the  hearth  a,  or  shelf  of  preparation 
(fig.  1031) ;  and  whenever  it  has  become  hot  (the  furnace  having  been  previously  brought 
to  bright  ignition),  it  is  to  be  transferred  to  the  decomposing  hearth  or  laboratory  b  by 
-  an  iron  tool,  shaped  exactly  like  an  oar,  called  the  spreader.  This  tool  has  the  flattened 
part  from  2  to  3  feet  long,  and  the  round  part,  for  laying  hold  of  and  working  by,  from 
6  to  7  feet  long.  Two  other  tools  are  used  ;  one,  a  rake,  bent  down  like  a  garden  hoe  at 
the  end ;  and  another,  a  small  shovel,  consisting  of  a  long  iron  rod  terminated  with  a  piece 
of  iron  plate,  about  6  inches  long,  4  broad,  sharpened  and  tipped  with  steel,  for  cleaning 
the  bottom  of  the  hearth  from  adhering  cakes  or  crusts.  Whenever  the  charge  is  shoved 
by  the  sliding  motion  of  the  oar  down  upon  the  working  hearth,  a  fresh  charge  should 
be  thrown  into  the  preparation  shelf,  and  evenly  spread  over  its  surface. 

The  hot  and  partially  carbonized  charge  being  also  evenly  spread  upon  the  hearth  b, 
is  to  be  left  untouched  for  about  ten  minutes,  during  which  time  it  becomes  ignited,  and 
begins  to  fuse  upon  the  surface.  A  view  may  be  taken  of  it  through  a  peep-hole  in 
the  door,  which  should  be  shut  immediately,  in  order  to  prevent  the^reduction  of  the 
temperature.  When  the  mass  is  seen  to  be  in  a  state  of  incipient  fusion,  the  workman 
takes  the  oar  and  turns  it  over  breadth  by  breadth  in  regular  layers,  till  h-  has  reversed 
the  position  of  the  whole  mass,  placing  on  the  surface  the  particles  which  were  formerly 
in  contact  with  the  hearth.  Having  done  this,  he  immediately  shuts  the  door,  and  lets 
the  whole  get  another  decomposing  heat.  After  five  or  six  minutes,  jets  of  flame  begin 
to  issue  from  various  parts  of  the  pasty-consistenced  mass.  Now  is  the  time  to  incoi^ 
rate  the  materials  together,  turning  and  spreading  by  the  oar,  gathering  them  together 
by  the  rake,  and  then  distributing  them  on  the  reverse  part  of  the  hearth;  that  is,  the  oar 
should  transfer  to  the  part  next  the  fire-bridge  the  portion  of  the  mass  lying  next  the 
shelf,  and  vice  versa.  The  dexterous  management  of  this  transposition  characterizes  a 
good  soda-furnacer.  A  little  practice  and  instruction  will  render  this  operation  easy  to  a 
robust  clever  workman.  After  this  transposition,  incorporation,  and  spreadins,  the  door 
may  be  shut  again  for  a  few  minutes,  to  raise  the  heat  for  the  finishing  off.  Lastly,  the 
rake  must  be  dexterously  employed  to  mix,  shift,  spread,  and  incorporate.  The  jets, 
called  candles,  are  very  numerous,  and  bright  at  first ;  and  whenever  they  begin  to  fade 
the  mass  must  be  raked  out  into  cast-iron  moulds,  placed  under  the  door  of  the  labonu 
tory  to  receive  the  ignited  paste. 

One  batch  being  thus  worked  off,  the  other,  which  has  lain  undisturbed  on  the  shelt 
IS  to  be  shoved  down  from  a  to  b,  and  spread  equally  upon  it,  in  order  to  be  treated  as 
above  described.    A  third  batch  is  then  to  be  placed  on  the  shelf. 

The  article  thus  ootained  should  contain  at  least  22  per  cent,  of  real  soda,  equivalent 
to  37  per  cent,  of  dry  carbonate,  or  to  100  of  crystals.  A  skilful  workman  can  turn  out 
a  batch  in  from  three  quarters  of  an  hour  to  an  hour,  producing  a  perfect  carbonate, 
which  yields  on  solution  an  almost  colorless  liquid,  nearly  destitute  of  sulphur,  and  con- 
taining hard}}'  any  decomposed  sulphate. 

In  some  soda-works,  where  the  decomposing  furnace  is  very  large,  and  is  charged  with 
a  ton  of  materials  at  a  time,  it  takes  two  men  to  work  it,  and  from  five  to  six  hours  to 
complete  a  batch.  Having  superintended  the  operation  of  the  above-described  small  fur- 
nace, and  examined  its  products,  I  feel  warranted  to  recommend  its  adoption. 

The  followiDET  materials  and  products  show  the  average  state  of  this  soda  process  — 
Materials.— m  parts  of  sulphate  of  soda,  ground,  equivalent  to  75  of  carbonate; 
1 10  of  chalk  or  ground  limestone ;  55  of  ground  coal ;  in  the  whole,  265. 

Products.— \6S  parts  of  crude  soda,  at  33  per  cent.  =  55-5  of  dry  carbonate. 

Or,      J  ^?!?    "■    crystals  of  carbonate  of  soda  =  48  of  dry    carbonate ;   aiii! 
'      ^100    —    msoluble  matter. 

But  these  products  necessarily  vary  with  the  skill  of  the  workman. 

In  anotner  manufactory  the  following  proportions  are  used  :— Six  stones,  of  14  lbs, 
each,  of  dry  ground  sulphate  of  soda,  are  mixed  with  3  of  chalk  and  3  of  coal.  This 
noixtnre,  weighing  U  cwt.,  forms  a  batch,  which  is  spread  upon  the  preparation  shelf 
of  the  furnace  (figs.  1037  and  1038),  as  above  described,  and  gradually  heated  to  inci- 
picLt  Ignition.  It  is  then  swept  forwards  to  the  lower  area  b,  ly  the  iron  oar,  and 
spread  evenly  by  the  rake.     Whenever  it  begins  to  soften  under  the  rising  heat  of  the 


SODA 


681 


laboratory  (the  side  doors  being  meanwhile  shut),  the  mnss  must  be  laboriously  turned 
over  and  incorporated ;  the  small  shovel,  or  paddle,  being  employed  to  Iransler,  by  tne 
interchange  of  small  portions  at  a  time,  in  rapid  but  orderly  succession,  the  whole  mate- 
rials from  the  colder  to  the  hotter,  and  from  the  hotter  to  the  colder  pw-ts  of  the  hearin. 
The  process  of  working  one  batch  takes  about  an  hour,  during  the  first  hall  ol  wbicn 
period  it  remains  upon  the  preparation  shelf.  The  average  weight  of  the  finished  baU 
is  1  cwt.,  and  its  contents  in  alkalimelrical  soda  are  33  pounds.  , 

Where  the  acidulous  sulphate  of  iron  from  pyrites  may  be  had  at  a  cheap  rate,  "  Has 
been  long  ago  employed,  as  at  Hurlett  in  Scotland,  instead  of  sulphuric  acid,  for  decom- 
posing the  chloride  of  sodium.  Mr.  Turner's  process  of  preparing  soda,  by  decomposing 
sea  salt  with  litharge  and  quicklime,  has  been  long  abandoned,  the  resulting  patent  yel- 
low, or  sub-chloride  of  lead,  having  a  very  limited  sale.  ^,    ,    ,    „ 

2.  The  extraciimi  of  pure  soda  from  the  crude  article.— The  black  balls  must 
be  broken  into  fragments,  and  thrown  into  large  square  iron  cisterns,  furnished 
with  false  bottoms  of  wooden  spars;  when  the  cisterns  are  nearly  full  of  these  lum^ 
water  is  pumped  in  upon  them,  till  they  are  all  covered.  After  a  few  days,  the 
lixivialion  is  effected,  and  the  ley  is  drawn  off  either  by  a  syphon  or  by  a  plug-hole 
near  the  bottom  of  the  cistern,  and  run  into  evaporating  vessels.  These  may  be 
of   two  kinds.     The   surface-evaporating  furnace,   shown    in  fig.    1317,  is    a    very 

admirable  invention  for  economizing 
vessels,  lime,  and  fuel.     The  grate  a, 
and  fireplace,  are  separated  from  the 
evaporating  laboratory  d,  by  a  double 
fire-bridge  b,  c,  having  an  interstitial 
space    in    the   middle,   to    arrest  the 
communication   of   a  melting    or  ig- 
niting   heat     towards    the    lead-lined 
cistern   d.      This  cistern  may  be  8, 
10,  or  20  feet  long,  according  to  the 
magnitude   of  the   soda-work,   and  4 
feet  or  more  wide.    Its  depth  should  be  about  4  feet.     It  consists  of  sheet  lead,  of  about 
6  pounds  weight  to  the  square  foot,  and  it  is  lined  with  one  layer  of  bricks,  set  in  Roman 
or  hydraulic  cement,  both  along  the  bottom  and  up  the  sides  and  ends.    The  lead  comes 
up  to  the  top  of  c,  and  the  liquor,  or  ley,  may  be  filled  in  to  nearly  that  height.     Things 
being  thus  arranged,  a  tire  is  kindled  upon  the  grate  A ;  the  flame  and  hot  air  sweep 
along  the  surface  of  the  liquor,  raise  its  temperature  there  rapidly  to  the  boiling  point, 
and  carry  ofl'  the  watery  parts  in  vapor  up  the  chimney  e,  which  should  be  15  or  20  feet 
high,  to  command  a  good  draught.     But,  indeed,  it  will  be  most  economical  to  build  one 
high  capacious  chimney  stalk,  as  is  now  done  at  Glasgow,  Manchester,  and  Newcastle, 
and  to  lead  the  flues  of  the  several  furnaces  above  described  into  it.    In  this  evaporating 
furnace  the  heavier  and  stronger  ley  goes  to  the  bottom,  as  well  as  the  impurities,  where 
they  remain  undisturbed.     Whenever  the  liquor  has  attained  to  the  density  of  1-3,  or 
thereby,  it  is  pumped  up  into  evaporating  cast-iron  pans,  of  a  flattened  somewhat  hemi- 
spherical shape,  and  evaporated  to  dryness  while  being  diligently  stirred  with  an  iron 
rake  and  iron  scraper. 

This  alkali  gets  partially  carbonated  by  the  above  surface-evaporating  furnace,  and  is 
an  excellent  article. 

When  pure  carbonate  is  wanted,  that  dry  mass  mu»t  be  mixed  with  its  own  bulk  of 
ground  coal,  sawdust,  or  charcoal,  and  thrown  into  a  reverberatory  furnace,  like^g.  1316, 
but  with  the  sole  all  upon  one  level.  Here  it  must  be  exposed  to  a  heat  not  exceeding 
650O  or  700°  F. ;  that  is,  a  little  above  the  melting  heat  of  lead ;  the  only  object  being  to 
volatilize  the  sulphur  present  in  the  mass,  and  carbonate  the  alkali.  Now,  it  has  been 
found,  that  if  the  heat  be  raised  to  distinct  redness,  the  sulphur  will  not  go  off,  but  wiU 
continue  in  intimate  union  with  the  soda.  This  process  is  called  calking,  and  the  fur- 
nace is  called  a  calker  furnace.  It  may  be  six  or  eight  feet  long,  and  four  or  five  feet 
broad  in  the  hearth,  and  requires  only  one  door  in  its  side,  with  a  hanging  iron  frame 
filled  with  a  fire-tile  or  bricks,  as  above  described. 

This  carbonating  process  may  be  performed  upon  several  cwts.  of  the  impure  soda, 
mixed  with  sawdust,  at  a  lime.  It  takes  three  or  four  hours  to  finish  the  desulphuration ; 
and  it  must  be  carefully  turned  over  by  the  oar  and  the  rake,  in  order  to  bum  the  coal 
into  carbonic  acid,  and  to  present  the  carbonic  acid  to  the  particles  of  caustic  soda  diffu- 
sed through  the  mass,  so  that  it  may  combine  with  them. 

\Vhen  the  blue  flames  cease,  and  the  saline  matters  become  white,  in  the  midst  of  the 
9oaly  matter,  the  batch  may  be  considered  as  completed.  It  is  raked  out,  and  when 
cooled,  lixiviated  in  great  iron  cisterns  with  false  bottoms,  covered  with  mats.  The 
watery  solution  being  drawn  off"  clear  by  a  plug-hole,  is  evaiwrated  either  to  dryness,  in 
hemisjherical  cast-iron  i)ans,  as  above  described,  or  only  to  such  a  strength  that  it  showt 


662 


SODA 


a  pellicle  upon  its  surface,  when  it  may  be  run  off  into  crystaUizing  cisterns  of  cast  iron, 
or  lead-lined  wooden  cisterns.  The  above  dry  carbonate  is  the  best  article  for  the  elast 
manufJEicture.  ** 

Crystallized  carbonate  of  soda  contains  62f  per  cent,  of  water.  The  crystals  are  colorlesi 
transparent  rhomboids,  which  readily  effloresce  in  the  air,  and  melt  in  their  own  water  of 
crystallization.  On  decanting  the  liquid  from  the  fused  mass,  it  is  found  that  one  part  of 
the  sa  t  has  given  up  its  water  of  crystallization  to  another.  By  evaporation  of  that  fluid, 
crystals  containing  one  fifth  less  water  than  the  common  carbonate  are  obtained.  These 
do  not  effloresce  in  the  air. 

Mineral  soda,  the  sesquicarbonate  {Anderthalb  kohlensaures  natrm.  Germ  )  is  found 
m  the  province  of  Sukena,  in  Africa,  between  Tripoli  and  Fezzan.  It  forms  a  stratum 
no  more  than  an  inch  thick,  just  below  the  surface  of  the  soil.  Its  texture  is  striated 
crystalline,  like  fibrous  gypsum.  Several  hundred  tons  of  it  are  collected  annually 
which  are  chiefly  consumed  in  Africa.  This  species  of  soda  does  not  effloresce  like  the 
Egyptian,  or  the  manufactured  soda  crystals,  owing  to  its  peculiar  state  of  composition 
and  density.  It  was  analyzed  by  Klaproth,  under  its  native  name  of  trcma,  and  was  found 
to  consist,  m  100  parts,  of— soda,  37 ;  carbonic  acid,  38 ;  sulphate  of  soda,  25 :  water. 
22*5,  in  100.  * 

This  soda  is,  therefore,  composed  of— 3  atoms  of  carbonic  acid,  associated  with  2  atoms 
of  soda,  and  4  of  water ;  while  our  commercial  soda  crystals  are  composed  of— 1  atom  of 
carbonic  acid,  1  atom  of  soda,  and  10  atoms  of  water. 

There  are  six  natron  lakes  in  Egypt.  They  are  situated  in  a  barren  valley,  called  Bahr- 
bela-ma,  about  thirty  miles  to  the  west  of  the  Delta. 

There  are  natron  lakes  also  in  Hungary,  which  afford  in  summer  a  white  saline  efflo- 
rescent crust  of  carbonate  of  soda,  mixed  with  a  little  sulphate. 

There  are  several  soda  lakes  in  Mexico,  especially  to  the  north  of  Zacatecas,  as  also  in 
many  other  provinces.  In  Columbia,  48  English  miles  from  Merida,  mineral  soda  is  ex. 
Iracted  from  the  earth  in  great  abundance,  under  the  name  of  ttrao. 

Bicarbonate,  of  soda  (Doppelt  kohlensaures  natrmy  Germ.),  is  prepared,  like 
bicarbonate  of  potassa,by  transmitting  carbonic  acid  gas  through  a  cold  saturated  solution 
of  pure  carbonate  of  soda,  till  crystalline  crusts  be  formed.  The  bicarbonate  may  also 
be  obtained  m  four-sided  tables  grouped  together.  It  has  an  alkaline  taste  and  reaction 
upon  litmus  paper,  dissolves  in  13  parts  of  cold  water,  and  is  converted  by  boiling  water 
into  the  sesquicarbonate,  with  the  disengagement  of  one  fourth  of  its  carbonic  acid.  It 
consists  of— 37  of  soda,  62-35  carbonic  acid,  and  10-65  water. 

Soda   Manufacture  Improved.     In  carying  on   this   process  on  the  great  scale   it 
was  long  customary  to  permit  the  escape  of  the  hydrochloric  acid  in  the  decomposition 
of  the  muriate  of  soda  by  sulphuric  acid  as  a  waste  product ;  and  this  is  done  in  some 
localities  at  the  present  day.     But  independently  of  the  actual  loss  thus  caused,  the  in- 
jurious action  of  the  acid  fumes  upon  every  form  of  vegetation,  for  many  miles  around 
the  manufactory,  has  compelled  the  maker  of  soda  to  condense  this  hydrochloric  acid,  by 
passing  it  through  flues  filled  with  coke ;  over  the  cavernous  surface  of  which  a  sraaU 
stream  of  water  constantly  flows.     In  this  way,  a  large  quantity  of  liquid  muriatic  acid 
IS  procured,  which,  though  too  impure  for  many  of  the  ordinary  requirements  of  the  arta 
*r^f  1  »?f"ably  adapted  for  the  generation  of  chlorine,  and  the  subsequent  manufacture* 
of  chloride  of  lime.    The  total  worth  of  this  waste  product  may  be  gathered  from  the 
fact,  that  in  one  set  of  large  soda  works  near  Glasgow,  sufficient  muriatic  acid  is  collected 
to  yield  8,000  tons  of  chloride  of  lime  per  annum,  and  yet  this  scarcely  represents  one- 
twentieth  of  the  soda  manufacture  of  Great  Britain.     Having  in  this  way  obtained  a 
quantity  of  sulphate  of  soda,  the  soda  maker  now  proceeds  to  his  next  operation     Here 
however,  it  may  be  as  well  to  remark,  that  the  sulphate  of  soda  in  question  is  not  nearly 
pure,  but  usually  contams  from  five  to  ten  per  cent,  of  common  salt,  which  has  escape'd 
decomposition  in  the  sulphate  furnace ;  as  it  is  more  economical  to  leave  a  small  excess 
of  chloride  of  sodium  than  to  add  a  superfluity  of  sulphuric  acid,— since  this  latter  is 
vastly  more  expensive  than  the  former;  and  the  presence  of  common  salt  is  rather  be- 
neficial than  otherwise  during  the  subsequent  process.     To  convert  this  impure  sulphate 
of  soda  into  carbonate  of  soda,  it  is  mixed  in  about  equal  proportions  with  chalk  or  car- 
bonate  of  lime,  and  small  coals,  all  in  a  state  of  rough  powder.     The  mixture,  merely 
thrown  togetJier  with  shovels,  is  projected  into  a  reverberating  furnace  called  the  ball- 
furnace,  where  it  IS  stirred  about  with  a  long  iron  paddle,  until  it  undergoes  an  imper- 
feet  fusion;  and  long  jets  of  yellow  flame,  technically  called  "candles,"  burst  out  from 
various  parts  of  the  mass,  which,  for  an  ordinary  charge  of  3  cwt.  or  4  cwt    will  re- 
quire about  three  hours.     The  whole  is  then  raked  out,  and  allowed  to  cool,  the  furnace 
being  supplied,  as  before,  with  a  fresh  charge  of  materials.    The  product  of  this  opera- 
tion IS  known  as  ball-soda,  and  it  consists  of  carbonate  of  soda,  sulphuret  of  sodium, 
chloride  of  sodium,  undecomposed  sulphate  of  soda,  carbonate  of  lime,  sulphuret  of 
calcium,  and  carbon  of  coke.    We  have  had  an  opportunity  of  examining  seyeral 


SODA  MANUFACTURE. 


683 


specimens  from  the  largest  manufactories  in  the  kingdom,  and  find  no  great  difference  in 
the  results.     The  average  composition  appears  to  be  as  under : — 


Soda 
Carbonic  acid 
Sulphuret  of  sodium 
Chloride  of  sodium 
Sulphate  of  soda 
Sulphate  of  calcium 
Carbonate  of  lime 
Coke 


19-80 
9-24 
2-64 
6-22 
610 
29-40 
21-70 
6-90 

100 


We  shall  describe  the  mode  of  analyzing  this  compound  a  little  further  on,  but  at 
this  moment  it  will  be  more  advantageous  to  pursue  the  remainder  of  the  operation  for 
procuring  carbonate  of  soda  from  the  cooled  product  of  the  ball-furnace.  This  substance, 
under  the  name  ball-soda,  is  roughly  broken  to  pieces,  and  piled  up  in  alarge  iron  tank, 
provided  with  a  false  bottom  or  grating,  and  having  an  aperture  near  the  bottom.  When 
the  tank  is  full,  the  aperture  near  the  bottom  is  plugged  up,  and  hot  water  run  upon  the 
ball-soda  to  within  an  inch  or  two  of  the  top  of  the  tank.  The  whole  is  allowed  to  remain 
for  several  hours ;  by  which  the  salts  of  soda,  consisting,  as  we  have  seen,  of  carbonate 
and  sulphate  of  soda,  with  the  chloride  and  sulphuret  of  sodium,  are  dissolved ;  the  plug 
is  then  withdrawn,  and  the  soluble  matters  are  allowed  to  flow  away  from  the  carbonate 
of  lime,  sulphuret  of  calcium,  and  coke,  whicli  are  insoluble.  Upon  these  latter  a  fresh 
portion  of  hot  water  is  poured,  so  as  thoroughly  to  remove  the  soda  salts ;  and  this  last 
solution  is  commonly  applied  to  a  quantity  of  new  ball-soda,  in  order  to  economize  the 
cost  of  evaporation.  The  first  fluid  from  the  tank  is  conducted  at  once  into  a  reverbera- 
tory  furnace,  where  the  water  is  rapidly  expelled,  and  a  dry  saline  product  obtained. 
This  is  immediately  transferred  to  what  is  called  the  carbonating  furnace,  where  the  sul- 
phuret of  sodium  is  partly  decomposed  by  the  carbonic  acid  of  the  furnace,  and  partly 
reconverted  into  sulphate  of  soda  by  the  oxygen  of  the  air. 

Meantime,  the  portion  of  soda  existing  in  the  mass  as  caustic  soda  becomes  carbonated 
by  the  carbonic  acid  of  the  fire ;  and  hence  the  name  of  this  particular  furnace.  Having 
been  kept  at  a  dull  red  heat,  but  short  of  that  required  for  actual  fusion,  the  whole 
is  withdrawn  and  cooled ;  after  which,  it  is  boiled  in  water,  and  the  concentrated  solu- 
tion run  off  into  shallow  coolers  to  crystallize.  As  the  saline  constituents  now  consist 
almost  entirely  of  carbonate  of  soda,  with  a  little  sulphate  of  soda  and  chloride  of 
sodium,  the  former  salt  crystallizes  and  becomes  solid ;  leaving  the  two  latter  with  a 
portion  of  carbonate  of  soda,  in  solution.  The  crystals  are  taken  out,  dried,  and  packed 
for  the  market ;  whilst  the  residuary  solution  is  evaporated  to  dryness,  and  the  result 
sold  under  the  name  of  soda-ash :  though  this  name  is  sometimes  also  applied  to  the 
direct  product  of  the  carbonating  furnace.    The  nature  of  the  decomposition  which  takes 

5 lace  in  the  ball-furnace  may  be  very  correctly  inferred  from  the  composition  of  the  pro- 
ucts  thence  ensuing.  We  have  seen  that  the  primary  mixture  is  composed  of  sulphate 
of  soda,  carbonate  of  lime,  and  carbon.  On  exposing  these  to  a  red  heat,  sulphuret  of 
sodium  is  generated,  which  immediately  acts  upon  the  carbonate  of  lime,  producing  sul-'^ 
phuret  of  calcium  and  carbonate  of  soda.  As,  however,  during  the  reduction  of  the 
sulphate  of  soda,  part  of  the  carbonate  of  lime  is  rendered  caustic  by  the  expulsion  of  its 
carbonic  acid,  this  caustic  lime  makes  its  appearance  in  the  ball  soda  tank,  and  converts  a 
portion  of  the  carbonate  of  soda  into  caustic  soda;  hence  the  necessity  for  the  carbonating 
furnace,  which  is,  moreover,  useful  in  destroying  the  sulphuret  of  sodium. 

We  shall  now  proceed  to  describe  the  mode  of  analyzing  ball-soda ;  after  which  it  will 
be  necessary  to  review  the  whole  process  of  soda-making,  with  a  view  to  the  possibility 
of  improvement. 

Having  selected  a  fair  sample  of  the  ball  soda  to  be  examined,  this  must  be  reduced 
to  an  extremely  fine  powder,  and  a  given  weight  of  it — stiy  100  grains,  digested  in  two 
ounces  of  hot  water  for  ten  or  fifteen  minutes;  then  throw  the  whole  on  a  filter,  and  wash 
this  gradually  with  3  ounces  of  boiling  water,  taking  care  to  add  these  washings  to  the 
first  liquid  which  passes  through  the  filter.  The  filter,  with  its  insoluble  contents,  may 
now  be  set  in  a  warm  place  to  dry.  Meanwhile,  the  clear  solutions  being  mixed,  are  to 
be  tested  with  finely  powdered  carbonate  of  lead,  until  this  ceases  to  be  blackened :  when 
this  occurs,  the  heavy  black  precipitate  of  sulphuret  of  lead  is  allowed  to  settle,  and  the 
clear  colourless  solution  is  poured  off  iirto  a  porcelain  basin.  This  being  gently  heated, 
is  now  to  be  thrown  upon  the  sulphuret  of  lead ;  and,  when  this  has  again  settled,  the 
clear  fluid  must  be  withdrawn  and  added  to  that  in  the  porcelain  basin.  This,  being 
gently  heated,  must  next  be  treated  by  a  dilute  acid  of  a  determinate  strength,  (stw 
Aikalimetry),  until  litmus  paper,  on  being  dipped  into  it,  becomes  slightly  reddened; 


684 


SODA  MANUFACTURE. 


"whea  the  amount  of  soda  present,  or  of  carbonate  of  soda,  may  be  inferred,  in  the  usual 
way,  from  the  composition  of  dilute  acid.     The  sulphuret  of  lead  remaining  from  this 
operation  is  now  to  be  supersaturated  with  acetic  acid,  and  slightly  heated,  for  the  pur- 
pose of  removing  from  it  any  excess  of  carbonate  of  lead  that  may  have  been  added  in 
the  first  instance ;  the  sulphuret  of  lead  must  then  be  well  washed  with  hot  water,  dried 
and  weighed.    Every  120  grains  represent  40  grains  of  sulphuret  of  sodium,  and  for 
this  32  grains  of  soda  must  be  deducted  from  the  result  of  the  acidulous  assay.     The  m- 
Boluble  matter  remaining  on  the  filter  is  now  to  be  transferred  to  a  double-necked  bottle 
provided  with  a  bent  tube,  for  passing  the  evolved  gases  through  a  solution  of  the 
acetate  of  lead  in  weak  acetic  acid.     This  insoluble  matter  consists  of  carbonate  of  lime, 
sulphuret  of  calcium,  and  coke ;  if,  therefore,  diluted  muriatic  acid  is  poured  upon  it,  the 
two  former  substances  will  be  decomposed  with  the  evolution  of  carbonic  acid  and 
sulphuretted  hydrogen,  the  latter  of  which  is  absorbed  by  the  acidulous  solution  of  the 
acetate  of  lead ;  whilst  the  carbonic  acid  passes  on  and  escapes.     In  combining  with  the 
solution  of  acetate  of  lead,  the  sulphuretted  hydrogen  gives  rise  to  the  formation  of  sul- 
phuret of  lead,  which,  being  well  washed  with  hot  water,  then  dried  and  weighed,  gives 
the  amount  of  sulphuret  of  calcium  existing  in  the  residue :  for  every  1 20  grains  of  sul- 
phuret of  lead  indicates  34  of  sulphuret  of  calcium.    The  fluid  in  the  two-necked  flask 
consists  of  chloride  of  calcium,  with  the  coke  of  the  ball-ash.    Tliis  must,  therefore,  be 
thrown  on  a  filter,  and  well  washed  with  hot  water,  and  dried :  the  coke  may  then  be 
separated  and  weighed.    As  from  the  existence  of  carbonate  of  soda  in  the  first  solution 
neither  lime  nor  its  sulphate  could  exist  in  the  insoluble  matter,  if  this  had  been  weighed 
previously  to  these  latter  experiments,  the  difference  in  weight,  after  deducting  the 
sulphuret  of  calcium  and  the  coke,  will  be  that  of  the  carbonate  of  lime ;  and  this,  under 
the  circumstances,  is  suflBciently  correct  in  moderately  skilful  hands.    It  now  remains, 
therefore,  only  to  determine  the  quantity  of  chloride  of  sodium  and  sulphate  of  soda 
present  in  the  ball-soda.   For  this  purpose,  100  grains  of  the  finely  powdered  compound 
are  to  be  treated  exactly  as  before,  with  hot  water  and  carbonate  of  lead.     In  this  case, 
however,  the  resulting  alkaline  solution  must  be  supersaturated  with  pure  nitric  acid, 
and  to  this  an  excess  of  nitrate  of  silver  must  be  added,  and  the  mixture  warmed.     A 
dense  coagulated  precipitate  will  fall,  from  which  the  clear  solution  being  poured  off 
into  a  proper  vessel,  the  precipitate  is  to  be  washed  with  a  little  boiling  distilled  water, 
and  the  washings  added  to  the  clear  solution  before  mentioned.     The  precipitate  being 
now  well  dried  in  a  dark  place  must  be  weighed;  and  for  every  144  grains  of  this  pre 
cipitate,  60  grains  of  chloride  of  sodium  must  be  assumed.     To  the  clear  solution  result- 
ing from  this  operation,  an  excess  of  nitrate  of  baryta  must  be  thrown  in,  and  the  mixture 
slightly  heated  as  before,  and  then  thrown  on  a  previously  weighed  filter.    This  filter, 
when  the  solution  has  passed,  is  to  be  repeatedly  washed  with  boiling  distilled  water, 
until  this  fluid  passes  through  pure ;  the  filter  is  then  to  be  well  dried  and  weighed,  to 
ascertain  its  increase  of  weight.    This  increase  is  due  to  the  presence  of  sulphate  of 
baryta,  for  every  117  grains  of  which  12  grains  of  sulphate  of  soda  must  have  existed 
in  the  portion  of  ball-soda  examined.    To  determine  the  amount  of  carbonic  acid  com- 
bined with  the  soda,  a  given  quantity  (and  for  this  purpose  50  grains  is  enough)  of  the 
finely-powdered  ball-soda  must  be  lixiviated  as  before,  and  the  clear  solution  boiled  down 
to  dryness  with  an  excess  of  pure  peroxide  of  manganese, — the  whole  being  at  last 
slightly  heated  over  the  fire.     By  the  action  of  the  manganese  at  this  heat,  the  sulphuret 
of  sodium  is  converted  into  sulphate  of  soda ;  and  if  the  soda  salts  be  now  dissolved  in  a 
small  quantity  of  water,  and  the  solution  placed  in  a  proper  flask,  provided  with  a  bent 
tube  containing  chloride  of  calcium,  to  arrest  moisture,  the  carbonic  acid  may  be  expelled 
by  a  known  weight  of  diluted  sulphuric  acid ;  and  presuming  tlie  flask  and  the  vessel 
containing  the  dilute  acid  to  have  been  carefully  weighed  before  and  after  the  experi- 
ment, the  loss  gives  at  once  the  weight  of  the  carbonic  acid  united  to  the  soda.    This 
appears  never  to  be  equivalent  to  the  amount  of  soda.    There  is  a  circumstance  connected 
with  the  lixiviation  of  ball-ash,  on  the  large  scale,  which  has  probably  escaped  the  atten- 
tion of  manufacturers,  but  is  of  considerable  importance  towards  securing  a  successful 
result.     The  general  practice  is  to  employ  hot  water  for  dissolving  out  the  soda  salts, 
and  to  retain  this  solution  in  contact  with  the  insoluble  residue  for  several  hours.     Theo- 
retically, this  is  incorrect,  and,  practically,  we  have  found  it  injurious.     Sulphuret  of 
calcium,  though  an  insoluble  salt,  is  not  absolutely  so ;  and  the  moment  this  substance 
in  solution  comes  in  contact  with   carbonate  of  soda,   double   decomposition   ensues, 
attended  with  the  production  of  carbonate  of  lime  and  sulphuret  of  sodium — a  process 
exactly  the  reverse  of  that  which  happens  under  the  influence  of  a  red  heat,  and  of  which, 
in  chemistry,  there  are  many  other  examples.   Thus  it  constantly  happens  that  sulphuret 
of  sodium  is  found  in  the  lixiviated  products  of  ball-soda.     If,  however,  cold  water  be 
employed,  and  the  contact  of  the  carbonate  of  soda  with  the  sulphuret  of  calcium  be 
considerably  diminished,  as  with  great  ease  may  be  done,  by  coarsely  powdering  the 
ball-soda,  instead  of  employing  it  in  lumos,  then  the  clear  solution  is  almost  entirely 


SODA  MANUFACTURE. 


es§ 


free  from  sulphuret  or  sodium,  and  is  devoid  of  colour;  whereas,  by  the  hot  water  pit>- 
Cii^,  this  fluid  is  invariably  of  a  dirty-green  hue,  and  has  an  offensive  odour  of  sulphu- 
retted hydrogen.  Now,  remembering  that  the  sulphuret  of  sodium  is  a  dead  loss  to  the 
manufacturers,  and  moreover  diminishes  the  market  value  of  the  rest  of  his  produce,  the 
question  of  hot  or  cold  water,  with  or  without  proper  pulverization  of  the  ball-soda,  is 
in  reality  a  very  important  affair. 

By  the  afore-recited  analysis,  it  appears  that,  out  of  22-91  parts  of  soda,  2*11  were 
combined  with  sulphuretted  hydrogen;  this  is  at  the  rate  of  more  than  9  per  cent.,  and 
would  form  a  handsome  addition  to  the  usual  profits  of  the  manufacturer.  One  of  the 
great  drawbacks  upon  the  manufacture  of  soda  is  the  difficulty  of  disposing  of  the  inso- 
luble residue.  This  contains  more  than  half  its  weight  of  sulphuret  of  calcium,  a  sub- 
stance which,  in  the  wet  state,  is  rapidly  decomposed  by  the  carbonic  acid  of  the  air 
with  the  evolution  of  sulphuretted  hydrogen  gas,  and,  if  moderately  dry,  is  almost  certain 
to  take  fire  by  contact  with  the  atmosphere,  and  thus  taint  the  surrounding  neighbour- 
hood with  its  sulphurous  emanations.  It  is  extremely  likely  that  this  refuse  product 
would  answer  the  purpose  of  lime  for  all  agricultural  uses,  and  also  furnish  sulphur  to 
such  crops  as  require  this  element, — plants  of  the  natural  order  cruciferae  for  example. 
Gas  lime  is  in  great  measure  a  perfectly  analogous  compound,  and  this  is  largely  used 
in  some  of  our  inland  counties,  and  found  to  be  an  extremely  beneficial  application. 
The  refuse  of  soda-works  has  not,  however,  assumed  a  similarly  favourable  character 
amongst  farmers;  and  it  is  now  a  real  and  growing  nuisance  to  the  manufacturer  of 
Boda. 

Perhaps,  after  all,  it  would  be  better  to  think  of  devising  a  remedy  for  preventing  the 
formation  of  this  residuum  than  seek  an  outlet  for  its  consumption.  With  tliis  view, 
we  venture  to  lay  the  following  process  before  our  readers,  embracing  within  itself  what 
may  be  termed  the  perfection  of  soda-making.  How  far  on  a  large  scale  the  difficul- 
ties might  increase  beyond  the  advantage,  our  experience  will  not  enable  us  to  judge ; 
but  in  a  moderate  way,  the  whole  of  the  operations  have  been  consecutively  tried  and 
found  satisfactory.  The  key  to  the  ultimate  decomposition  turns  upon  a  circumstance 
in  chemistry  which  is,  for  the  most  part,  but  little  known :  and  that  is,  the  ease  with 
which  the  hydrosulphates  of  the  alkalis,  when  slightly  moistened,  are  converted  into 
carbonates  by  the  action  of  carbonic  acid.  If  much  water  be  present,  the  decomposition 
goes  on  languidly,  and  is  never  perfect ;  if  too  little  water,  the  decomposition  is  speedily 
arrested  by  the  formation  of  a  crust  of  alkaline  carbonate.  It  is  the  middle  state, 
between  these  two  conditions,  which  must  be  aimed  at,  and  which  we  will  now  proceed 
to  describe  in  a  condensed  account  of  the  proposed  method : — With  a  precisely  similar 
form  of  apparatus  to  that  now  in  use  for  preparing  sulphate  of  soda,  and  condensing 
muriatic  acid,  but  with  some  little  additional  care,  a  given  weight  of  common  salt 
might  be  converted  into  sulphate  of  soda,  and  the  whole  of  its  muriatic  condensed, 
which,  of  course,  would  be  an  exact  equivalent  of  the  soda  present  in  the  sulphate  of 
soda ;  that  is  to  say,  60  parts  of  chloride  of  sodium  and  49  parts  of  pure  hydrated 
sulplmric  acid  would  produce  72  parts  of  dry  sulphate  of  soda,  and  37  parts  of  anhy- 
drous muriatic  acid.  These  relative  proportions  must  be  borne  in  mind  to  facilitate  the 
comprehension  of  the  ultimate  process.  Having  placed  the  muriatic  acid  on  one  side 
for  the  present,  we  proceed  to  conv^t  the  sulphate  of  soda  into  sulphuret  of  sodium,  by 
mixing  it  with  its  own  weight  of  coarsely  powdered  coal  or  coke,  and  exposing  the 
mixture  to  a  red  heat  in  a  proper  furnace  for  an  hour  or  two.  At  this  temperature  the 
carbon  of  the  coal  unites  with  the  oxygen  of  the  sulphate  of  soda,  and  flies  off  as  car- 
bonic oxide  gas,  leaving  the  sulphur  and  sodium  combined  together  as  sulphuret  of 
sodium,  with  the  excess  of  small  coal  or  coke  employed.  As  soon  as  this  mixture  is 
sufficiently  cool,  it  should  be  broken  or  pounded  into  a  rough  powder,  which  must  now 
be  moistened  with  water  to  the  consistence  of  damp  sand,  or  until  a  handful  tightly 
squeezed  in  the  hand  adheres  together  as  a  ball  or  lump.  Wlien  this  is  the  case,  the 
whole  should  be  placed  in  a  vessel,  or  set  of  vessels,  similar  to  those  used  for  the  purifi- 
cation of  coal-gas  by  means  of  slaked  lime.  It  is  best  to  have  four  of  these  vessels, 
three  of  which  are  to  be  continually  in  action.  The  moistened  sulphuret  of  sodium  or 
hydrosulphate  of  soda  being  duly  an-anged,  a  stream  of  carbonic  acid  is  made  to 
traverse  the  three  vessels  in  action,  by  which  the  hydrosulphate  of  soda  is  converted 
into  carbonate  of  soda,  and  the  hydrosulphuric  acid,  or  sulphuretted  hydrogen,  being 
expelled  in  a  pure  state,  may  readily  be  burnt  at  a  jet  in  a  common  sulphuric  acid  cham- 
ber, with  the  usual  dose  of  nitrate  of  soda  for  its  acidification.  Thus  the  quantity 
of  sulphuric  acid  originally  employed  to  decompose  the  salt  would  be  constantly 
regenerated  and  used  over  again.  The  requisite  carbonic  acid  would  also  be  easily 
procured  by  acting  upon  chalk  with  the  muriatic  acid  condensed  in  the  first  instance. 
Some  fear  might  seem  to  be  justified  by  the  possibility  of  the  carbonic  acid  passing 
off  with  the  sulphuretted  hydrogen ;  but,  under  common  care,  guided  by  experience, 
this  could    never  occur.     So   long    as  any  considerable    quantity  of  hydrosulphate  of 


686 


SODA  WATER 


soda  remained  in  the  second  and  third  vesaeb,  no  carbonic  acid  could  pass  throuffh  them  • 
and  as  soon  as  No.  1  was  discoyered  to  be  saturated,  this  might  be  tfcrown  ou?!f  ^0' 
and  the  fourth  vessel  employed;  meanwhile  No.  1.  might  be  emptied  and  refiSed  w?th 
^^luali;  '''''""  °"  "''"  """•  '•'  ^^'°  *'^  ^^^^'^  ^^«^^  ™  luxated ;  and  rhu. 

In  comniencing  this  description  we  assumed  at  first  60  parts  of  common  salt  and  49 
of  hydrated  sulphuric  acid,  which  would  give  72  of  sulphate  of  soda  3  87  of  muriafic 
acid      Now  these  72  of  sulphate  of  soda  would  form  49  of  hydrosulphate  of  soda    wS 
37  of  muriatic  acid  by  acting  upon  chalk,  would  furnish  exactly  sufficient  ir^nir  acid 
to  convert  the  49  of  hydrosulphate  of  soda  into  54  of  carbonate  of  soda^  a^d T 7Tf  sul- 
phuretted  hydrogen.     But  this  sulphuretted  hydrogen,  when  carefully  consumed  woula 
regenerate  49  parts  of  sulphuric  acid,  to  be  again  used  in  decomposing  60  pa™  s  of  Zi 
mon  salt,  and  so  on  in  continual  rotation.    The  only  resulting  product?  wouW  therefore 
be  carbonate  of  soda  and  muriate  of  lime;  the  silphuric  acid  merely  perforS  the 
part  of  a  vehicle  for  effecting  the  decomposition.  ^As  regards  the  economy  of  thit 
process.  It  seems  m  no  way  doubtful ;  and,  viewed  in  a  practical  light,  there  is  no  insT 
mountable  or  even   probable   difficulty  in  the  way  of  ite  immediate   and   successful 
adop  ion:  necessarily  there  would  arise  some  loss  from  waste  and  commercial  inTpuritfes 
Zv  h!  "^T   A   'Pf^pl^t^^^  '"^ustry  is  very  large,  and  all  risk  of  much  loss  by  failun; 
D  ext/ndirlr''^'"  reasonable  limits  by  beginning  upon  a  very  small  scale  at  firs^ 
and  extending  the  manufacture  m  proportion  to  the  success  of  the  enterprise      The 
?3nTTJ^'°'  «^.f "^P^V«*  «f.  <^^><^i"°i  ^^"ch  arise  under  the  present  system,  and  con- 
^T.aV^^  ^J'  ^^^^tj^^'^  pestiferous  exhalations,  proclaim  too  obviously  that  a  change 
{llfK     'a^I^  '°??®  'r^^.  ""{  *^^  enormous  mass  of  matter  thus  daily  accumulating  may 
^rod^cZf  f°S;'^''  ^-f'  ^^^  °""  soda-maker  alone  admitted  to  us  that  his  afer^^ 

£;nur-:!y.'i^7?;^",;r "'  ''^  "'^  ^' '''  ^°^  ^'  "•^^^  ^^ ''''''  *«-  ^' 

«  ??.?  Ki"^^^^^'  ^®  ?®  "*°^®  ^^^®"  *°  ^»t"  containing  a  minute  quantity  of  soda 
and  highly  charged  with  carbonic  acid  gas,  whereby  it  acquires  a  sparkHng  anpeara^e' 
ILlutZ^LZ^'T'^r'^^^  exhilarating  quality,  and  certain  m'l^icina^l  powers     iJ 
constitutes  a  considerable  object  of  manufacture  in  this  kingdom.     The  followin-  fi-ure 
represents  I  understand,  the  best  system  of  apparatus  for  preparing  it.    A  ven-  dilule 

IlieXi^fdTxXuon!"""^  ^"^^'"^  P"'"^-^^^'  -  -"  beUerstood  from' 
nf  Ji'v  n^T  *PP*™^''«  '"fy  ^^^^.  **»'•  "taking  any  species  of  aerated  water,  in  imitation 
IT.  iTt  'f""^-  ^"  ^^^^  i'  necessary  for  this  purpose,  is  to  put  inti  the  cistern 
Q,  the  neutro-salme  matter,  earths,  metallic  oxydes,  pure  water,  &c.,  each  in  due  pro- 

Sr'thT'^T  '"  I^'  T^  ".'"'^'^^  *""^>'^'^  «^*^«  ^i"«^«l  ^«te;  to  be  imitated'^  t^ 
nfiln.tP  h  f^lh  T  '°.  '"'^  'l'"'^  '^".  "'"?^^"'"'  «'  *»>^°^§»»  ^^«  pipe  «»  «"d  then  to  \m. 
Se  gasometer  F  ^^''^'    ^  ^""^^      '^'  appropriate  gas,  previously  contained  in 

,   Thus,  to  make  Seltzer  water,  for  each  12  pounds  troy,  =  69,120  grains,  or  1  eallon 

l«^nT.t^^"T^^'  '*^'.  ^%rrf  *^^  ^^^^"^ie  ^^^^>  57  of ^rbo^ate  of  Hme^ 
1?^  nf  !h^"V^  of  magnesia,  3|  of  subphosphate  of  llumina,  3  of  chloride  of  potassium 
Ih^oLl^f^  i  ^?^^"">,;"d  3  of  finely  precipitated  silica.  Put  these  materials  inTo 
ThP^  tn?Wh^"*^  ""l-'^V^l  gasometer  F  with  353  cubic  inches  of  carbonic  acid  eas. 
Then  work  the  machine  by  the  handle  of  the  wheel  x,  as  explained  below,  and  reeulate 
the  introduction  of  the  liquid  and  the  gas  in  aliquot  portions;    for  ex;mple'T  the 

ri'^' w?hf7«''' v'^^  V^"??5  "^'l'^'  ^  '^'^  '^^'  ^"^'^tity  of  liquid'^should  b^ 
^i  ^!i    '  ^  ^^?  *'"*''^  ^"''^^^  f  ^^^  »*"'  ^ei'^-  «^e  half  of  the  whole  quan  ity.     The  sul! 
phureted  mineral  waters  may  be  imitated  in  like  manner,  by  taking  the  nro^rtion/oJ 
Aeir  constituents,  as  given  in  Table  11.  of  Wateks,  MikeraL        ^         Proportions  of 

of  Mr^F  V^^p/J"*^'  n ''V'^  <^«"J«ine^d  series  of  Newton's  Journal,  the  patent  apparatus 
Of  Mr.  F.  C.  Bakewell,  of  Hampstead,  for  making  soda  water  is  well  descrihpVl  Ji*h 
Illustrative  figures.  The  patent^was  obtained  in krch,  1882 'but  how  far  h^  ^en 
introduced  into  practice  I  have  not  heard.    Its  arrangement  discovers  ingenuity  bu?^? 

no o'j^t  ^'tf/  *°  P""^^"  ^"""^^^^  '^""  '^'  P^*^"^  ^PP^^atus  of  Mr.  Tyler.  wLh^;* 
1320.  m  the  following  page  represents,  according  to  his  latest  specification  a  is  the  S^' 
generator,  where  the  chalk  and  sulphuric  acid  are  mixed;  b,  the  gasometer-  c  the  soda! 
water  pump  for  forcing  the  gas;  d.  the  condenser;  e,  the  8olutioT^(ot  Todaj  pan  f,  the 
bot  1  ng  cork;  g,  the  acid  bottle,  at  the  right  hand  shoulder  of  a-  h  the  wheels  fo? 
working  the  agitator  n  the  condenser ;  i,  th^e  pipe,  for  conveying  the  Vs  toThe^ump- 
rh/  ,^,  n.''''"^^"  *^^  ?^"*-^"  V^^-  P"™P'  ^'  *^^«  f°^  regulating  the  admisdon  of 
the  gas  into  solution ;  m  drawmg-off  pipe  leading  to  the  bottling  cSrk ;  n,  the  forcing 
pipe  from  the  pump  to  the  condenser.  .  ^"rcing 

The  vessel  in  which  the  soda  water  is  condensed  is  lined  with  silver  in  order  to  resist 


SODA-WATER,  ^  ggT 

IMPROVED  SODA-WATER  APPARATUS,  AS  MADE  BY  MR.   HAYWARD   TYLER, 

OF  MILTON  STREET, 

Fig.  1318,  front  view  of  the  soda  water  machine.    Fig,  1319,  end  view  of  the  sam« 


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688 


SODIUM. 


SODIUM,  the  metallic  basis  of  soda,  is  obtained  by  processes  similar  to  those  by  which 
potassium  is  prcjcured.  By  fusing  hydrate  of  soda  with  a  little  hydrate  of  potassa,  a  mix- 
ture is  obtained,  which  yields  more  readily  than  soda  by  itself  to  the  decomposing  action 
of  iron-turnings  at  a  high  heat,  in  a  bent  gun-barrel.  The  portion  of  potassium  pro- 
duced may  be  got  rid  of,  by  digesting  the  alloy  for  a  few  days  in  some  naplha  or  oil  of 
turpentine  contained  in  an  open  vessel.  The  sodium  remains  at  the  bottom  of  the 
liquid.  Pure  sodium  may,  however,  be  prepared  at  once,  by  subjecting  incinerated  tar- 
trate of  soda  to  heat  in  the  apparatus  of  Brunner,  described  under  Potassium.  It  is 
white,  like  silver  ;  softer  and  more  malleable  than  any  other  metal,  and  may  be  readily 
reduced  into  very  thin  leaves.  It  preserves  its  malleability  till  it  approaches  the  melting 
point.  Its  specific  gravity  is  0'970.  It  softens  at  the  temperature  of  122°  F.,  and  at 
200°  it  is  perfectly  fluid ;  but  it  will  not  rise  in  vapor  until  heated  to  nearly  the  melting 
point  of  glass.  In  the  air  it  oxydizcs  slowly,  and  gets  covered  with  a  crust  of  soda;  but 
it  does  not  take  fire  til!  it  is  made  nearly  red-hot ;  and  then  it  emits  brilliant  scintilla- 
tions. When  thrown  upon  water,  it  is  rapidly  oxydized,  but  without  kindling,  like 
potassium.     If  a  drop  of  water  be  thrown  upon  it,  it  becomes  so  hot  by  the  chemical  ae- 


SOILS,  ANALYSIS  OF.  689 

Jl?  i^*jr  ^^^t'^'    '^T^  ^'^i  ^"^  ^^^  °^  «^""  ;  >•  *»^«  «"^»d« ;  2.  the  oxide,  or 

the  basa  of  common  soda;  and.  3.  the  suroxide;  the  list  being  formed  when  eodiuii  k 

•  heated  to  redness  upon  a  plate  of  silver.  «»*^um  » 

-^?2?n^of;«;^^^lP  J^r  ,•  ^^"»g  been  some  time  ago  engaged  in  a  minute  chemical 
tZetZ  lli  ?r^  l'^^  ^^'^^  farm,  remarkable  for  perennial  fertility  without  manur^ 

extent  ^  orJ^ied  hv'^.r^'^"'"  T^^'^'^  T^°^«  of  analysis,  which  may  to  a  certaii^ 
extent  be  practised  by  ordinary  farmers,  and  may  throw  some  %ht  on  the  means  of 
miproymg  permanently  the  composition  of  their  lands.  The  fidd  from  whic^  thT^p^. 
subject  of  analysis  was  taken,  is  situated  on  Marsh  Farm,  in  HrelinTle^eL  h,  theTrS 

R  M  Kerd^u  C'^'m  d'%  rT  t'  ^'^^*  *^^  '^*^---'  ^^  neafl^p?o"tl  toS 
Ln  app  i^^tl?s'fa;m'o^-^n^n'  ^'  proprietor,  informs  me  that  no  minure  has  ever 
oeen  appiieu  to  this  farm  of  200  acres,  durmg  a  period  of  at  least  fiftv  vears  exceot 
once ;  and  in  that  season  the  wheat  became  so  heavy  as  to  be  in  a^reat  meLu^'sSu 
It  produces  every  variety  of  crop  most  abundantly  '"  ^  *°  »  ^rent  measure  spoiled. 

The  substratum,  which  lies  beneath  a  three-feet  bed  of  the  soil  is  an  alluvial  denoait 
replete  with  decaying  vegetable  matter;  the  remains  prol^blTof  s^e  ance^^^ 
hLdtu^JTed^Jirr.e^^'^^^^^^^^^        1  *'^  ^f  ^^l--  B^^b^LlThVS^^^ 
aS^Then  it  w^^stoDPed  nL T    11'  ^^^T  ''  «"bmerged  till  about  two  centuries 

uniform  texture  and  appearance;  being  a  finely  comminuted  friable  loam,  quite  frS 

from  stones,  consisting  of  a  fortunate  mixture 
of  fine  siliceous  sand,  clay,  oxide  of  iron,  and 
carbonate  of  lime,  with  minute  proportions 
of  phosphate  of  lime  and  magnesia,  but  very 
little  organic  matter.  It  would  seem,  there- 
fore, to  derive  its  principles  of  fertility  chiefly 
from  the  atmosphere,  and  tiie  emanations  from 
the  subsoil. 

The  specific  gravity  of  the  soil,  in  its  average 
state  of  dryness,  is  2-2  to  water  called  10; 
indicating  the  presence  of  but  little  vegetable 
mater. 

100  parts  of  it  collected  after  a  period  of 
ordinary  drv  weather  lose  112  by  a  steam 
heat  of  212°,  and  readily  re-absorb  that  por- 
tion of  moisture  when  again  exposed  to  damp 
air.  When  the  dried  residuum  is  calcined  at  a 
dull  red  heat,  six  parts  of  vegetable  substance 
are  burned  away;  at  a  higher  temperature 
the  carbonate  of  lime  would  become  calcined, 
and  cause  an  additional  loss  of  weight,  which 
might  inconsiderately  be  misti^en  for  organic 
matter. 

The  first  problem  in  an  agricultural  analysis, 
is  to  find  the  proportion  of  calcareous  matter, 
as  carbonate  and  phosphate  of  lime.  Thia 
may  be  easily  solved  with  the  aid  of  the  fol- 
lowing instrument  {Jiff.  1321.),  which  may  be 
called  the  Limestone  Meter,  one  of  which  was 
presented  and  explained  by  me  to  the  Council 
of  the  Royal  Society  of  Agriculture  on  the 
29th  of  May,  1848. 

A,  is  a  cylinder  of  glass,  two  inches  in 
diameter,  and  fourteen  inches  long,  graduated 
on  one  side  with  a  scale,  into  spaces  of  100 
water -grain  measures  from  0  to  12,000,  marked 
10,  20,  80,  Ac.;  and  graduated  on  the  other 
side  into  spaces  of  240  water  grain-measures, 
each.  The  former  scale  is  used  for  the  analysis 
of  all  sorts  of  alkaline  carbonates,  and  also  of 
acids ;  the  latter  is  adapted  to  the  direct 
analysis  of  carbonate  of  lime  and  marls ;  and 
indirectly  to  that  of  phosphate  of  lime  and 
carbonate  of  magnesia. 

•  AU  the  RtsWe-yard  dung  is  sold  by  the  farmer. 


W{) 


SOILS,  ANALYSIS  OP. 


The  cylinder  a,  has  a  tubulure  in  its  side  near  the  bottom  ;  this  is  closed  with  a  cork, 
m  the  axis  of  which  a  short  glass  tube  is  cemented,  hooped  externally  to  a  collar  of 
caoutchouc  E,  which  serves  as  a  joint  to  the  upright  long  glass  tube  b,  heM  near  its  upper - 
recurved  end  m  a  hooked  wire.  .    *^^ 

The  top  of  the  cylinder  a  is  closed  with  an  elastic  cork,  through  a  perforation  in  which 
the  taper  tail  of  the  little  phial  c  passes  air-tight.  The  small  tube  f,  open  at  both  its 
ends,  IS  cemented  on  its  outer  surface,  into  the  bottom  of  the  phial  c,  so  as  to  close  it, 
whUc  the  tube  itself  opens  a  free  passage  to  gaa,  from  the  shoulder  of  the  phial  down 
mto  the  cylinder  a.  ^ 

The  mouth  of  the  phial  c  is  shut  with  a  cork,  through  which  the  small  end  of  the  tube 
1)  passes  air- tight.  The  tube  d  is  graduated  into  spaces  of  10,  20,  Ac.  water-grain 
measures  up  to  250,  and  is  closed  at  top  with  a  stopcock.  Its  lower  and  capillary 
extremity  is  recurved. 

In  ascertaining  with  this  instrument  the  proportion  of  real  carbonate  of  lime,  in  any 
lime-stone,  marl,  or  soil,  proceed  as  follows : — 

Lift  out  the  phial  c,  and  pour  water  into  the  cylinder  a  till  it  stands  about  half  an  inch 
below  the  line  marked  o,  and  fill  up  this  space  with  common  linseed-oil.  Restore  the 
phial  c  to  its  place,  pressing  it  in  air  tight.  Then  take  out  its  cork  with  its*  graduated 
tube,  and  introduce  into  the  phial  as  many  grains  weight  of  the  soil  or  marl  as  it  is  proper 
to  operate  upon.  Of  an  average  limestone  50  grains  are  sufficient,  because  the  magnified 
scale  of  the  lime- proof  is  adapted  to  the  analysis  of  50  grains  of  pure  carbonate  of  lime. 
Of  soils  and  marls,  100,  200,  or  even  500  grains,  may  be  taken,  because  these  sub- 
Btances  will  rarely  contain  one- tenth  their  weight  of  carbonate  of  lime.  But  as  the 
result  may  always  be  obtained  within  five  minutes,  at  the  cost  of  half  a  farthing, 
several  successive  experiments  may  be  made  on  diflFerent  weights  of  the  sample! 
Having  introduced  the  proper  weight  of  the  object  into  the  phial,  cover  it  with 
water,  till  this  stands  a  little  above  the  point  to  which  the  recurved  tube  descends. 
Holding  D  in  the  hand,  dip  its  bent  point  into  a  phial  containing  ordinary  muriatic 
(hydrochloric)  acid,  diluted  with  its  own  bulk  of  water,  and  applying  the  mouth  to  the 
opened  stop-cock,  suck  up  the  acid  into  the  tube  till  this  be  about  two-thirds  full,  then 
turn  the  key  of  the  cock  before  it  is  taken  from  the  lip,  and  the  acid  will  not  drop  out 
when  the  tube  is  held  upright.  Replace  the  cork  with  its  tube  d  in  the  phial  c.  Detach 
the  long  tube,  b,  from  its  wire-rest  with  the  left  hand,  and  hold  its  curved  extremity 
above  an  empty  basin  ;  then  with  the  right  hand  open  the  stop  cock  of  d,  to  let  a 
little  acid  run  down  upon  the  marl,  but  shut  it  almost  instantly  again,  lest  too  much  acid 
should  escape,  and  cause  so  brisk  an  effervescence  as  to  occasion  an  overflow  of  the  mix- 
ture into  the  small  tube  f.  The  disengaged  carbonic  acid  escapes  through  the  tube  f, 
presses  on  the  surface  of  the  oil  in  a,  and  causes  a  stream  of  water  to  flow  from  the  tube 
B,  into  the  subjacent  basin.  "When  the  water  ceases  to  run,  open  the  stop-cock  again, 
when  more  acid  will  descend,  cause  a  fresh  extrication  of  gas,  and  a  further  flow  of 
water.  The  curved  end  of  the  tube  b  should  be  progressively  lowered,  as  the  oil  falls  in 
a,  so  as  to  maintain  its  level  and  that  in  the  tube,  in  the  same  horizontal  plane.  When- 
ever gas  ceases  to  be  extricated  by  the  muriatic  acid,  the  experiment  is  completed,  and 
the  number  on  the  lime-meter  scale  opposite  to  the  upper  surface  of  the  oil,  denotes  the 
number  of  grains  of  carbonate  of  lime  in  the  quantity  of  limestone,  marl,  or  soil,  put 
into  the  phial  c  for  experiment.  A  little  carbonic  acid  gas  remains  condensed  in  the 
muriatic  solution,  but  tliis  is  not  more  than  equivalent  to  the  bulk  of  liquid  acid  intro- 
duced into  the  capacity  of  the  apparatus ;  so  that  no  compensation  need  be  made  on  this 
account.  For  the  purpose  of  minute  chemical  research,  that  portion  of  gas  may  be 
expelled  by  surrounding  the  phial  c  with  a  cloth  wrung  out  of  hot  water,  and  the  volume 
of  dilute  acid  added  may  also  be  taken  into  the  account.  Thus  the  composition  of  carbo- 
nates by  an  acid,  and  of  acids  by  a  bi-carbonate,  may  be  determined  by  means  of  this 
instrument  with  equal  rapidity  and  precision. 

The  contents  of  thephial  may  be  poured  out  into  a  porcelain  capsule,  gently  heated,  and 
thrown  on  a  filter.  The  lime  of  the  carbonate,  as  well  as  the  phosphate  of  lime  and  the 
magnesia,  will  pass  through  in  solution  along  with  a  very  little  iron.  On  super-saturating  the 
acidulous  liquor  with  water  of  pure  ammonia,  phosphate  of  lime  (if  present,  will  fjill,  and 
may  be  drained  on  a  filter  and  dried.  Taken  off  the  dried  filter,  and  digested  with  a  little 
dilute  sulphuric  acid,  sulphate  of  lime  will  result,  characterized  by  its  entire  insolubility  in 
dilute  alcohol.  Hence  the  sulphate  washed  with  vinous  spirits,  dried  and  calcined,  will  repre- 
sent by  its  weight  one-fifth  more  than  the  original  weight  of  the  phosphate.  By  the  action 
of  the  sulphuric  acid,  the  iron  precipitated  by  the  ammonia  with  the  phosphate  is  got  rid  of 

The  magnesia,  unless  its  proportion  has  been  very  great,  will  all  remain  dissolved  as 
ammonia-muriate,  and  its  quantity  may  be  ascertained  by  precipitating  it  either  vith 
soda,  or  phosphate  of  soda.  In  the  former  case,  the  substance  obtained,  when  wa^ed 
on  a  filter,  dried  and  ignited,  is  pure  magnesia;  in  the  latter,  it  is  the  ammonia- 
machine. 


SOILS,  ANALYSIS  OF.  591 

Cv''jf!^t^^°lf'T!''!'* :  ^"^  "^^^^ ^"^^  ^t  t»>e moderate  heat  of  120°  Fahr   it  represents 
ma^esl^      "^"'  '"^  '^"^'  *'"'  "^  *^^  ^^^«'^  P^«««"t;  or  for  100  parTs^lTi  of 

YenTent:-* '^"^^'*'  ^*^^"'  ^^  '^"  "  *^  ^  ™»^«'  ^^^  following  apparatus  is  con- 

hoW  iTfels^/rou^rhf'  "'f"^"''  f\^  '"J^"^.i"  ""'  *^^"^^«  t»^'n  ^^'^^'     Tl.is  should 
yl  r.u.f}         quart  of  water;  and  when  the  soil  and  dilute  acid  are  introduced  it  is  to 

this  way  til  every  constituent  of  the  soil,  except  the  silicaT  becomes  duL.lvS  ^M , 

quaatitTlha1,re".i"^  preferred  for  the  analyjis  of  soils,  »d^rJwhat'^''greatr 
quantity  than  the  bases  in  the  given  weight  of  soil  can  npufralio-      Tn,«  f     ^1       j 

Fg™  ™i.ytlu'roo^™iror%  rrn-^^?  -^"^^f "  ^:J!zrl::a 

fnr  «f  q\      -^      x^/^^*^*?^  ^^  ^^'^  *°  *^®  *<^^»o»  of  boiling  dilute  acid  in  this  wav 

rfiit:^\'irsi;:r^^r^i  rsL'TJi'^njr:^^^^^^^ 

|*.ai„s  »  the  "filter  having  been  washed'  i'n  2' p" 'ts  dr^d!  i^^ed:'^ 

The   alumina,  iron-oxide,  and   phosphate   of  lime    thrown   Hnwn   l,«^  ♦!,«   „ 
being  washed  in  the  filter,'and  dr?ed  I  a  cheesy TonsiSce?  a^eT^moU  :ith  a™Ze 

potSThettv 'tt''.r^^  -^^^  ^-*  in  ai:rutTon\'f  p^u^e 

fw    K       iu  ^  ^u   ^^"""'"^  IS  dissolved,  when  its  alkaline  solution  is  to  be  oassed 
through  a  filter,  then  saturated  with  muriatic  acid,  and  next  supersaturated^  wTth 

action  of  dilute  alcohol,  acidulated  ^ith  sulphuric  acid  afag^^^^^^^^  heat  ftiul  h^ 
iron  oxide  will  be  dissolved,  and  its  solution  may  be  passed  through  a  fiher  wh^le  h! 
sulphate  of  lime  will  remain  upon  it,  to  be  dried,  ignited,  and  weighed  FT;e  parts  of 
of  «Z?'P"^l5u''  f-""'  ^^  P^o«Phate.  The  iron  is  obtained  by  predpUation  with  water 
Tr  W  fi  ''*7'r^"^  ^Sniiion.-For  phosphoric  add,  see  thfseguel 
Ihe  tirst  filtered  hquor,  with  excess  of  ammonia,  contains  the  lime  of  the  car 
bonate,  and  the  magnesia.     The  former  is  separated  by  a  solution  of  oxalate  of  Tm 

iSonT>f  f.^'^'^'r.'".  "  "^"^r^^  "^^"^*^  ^«^  *  ^«-  h°"^«'  filtratln  and  very  genUe" 
TJl  ■  t^^y^'^.ed  dry  powder,  when  the  pure  carbonate  of  lime  is  obtained  The 
magnesia  exis  ing  in  the  filtered  liquor  as  an  amnion ia-muriate,  may  l^  oEed  hv 
precipitation  with  soda,  or  phosphate  of  soda,  as  already  described      ^  ^ 

it  Wnn?*"^  refractory  soils,  in  which  the  alumina  exists  as  a  double  or  triple  silicate 

t  m^,T,  t  "Tf  %*'*  ^"'l^^  ^'^'"^  °^  '^^  «^™P^^'  i"  fi"«  powder,  mixeS  with  foS 
r  S!  „i  1^^/^  '*  ''^•?'*^  carbonate  of  soda,  the  mixture  being  put  into  a  platilim  cr^ 
The  ^rnoihrr-"'^  7  ''?  Centre  50  grains  of  hydrate  of  ^tash  being  1^ 
The  crucible  being  slowly  raised  to  a  red-white  heat,  affords  a  fufed  liauid  nnit^ 
homogeneous,  of  a  grey  or  brown  colour  according  to  th^  metals  present    n  i       M«n 
ganese  gives  a  purple  tint;   and  iron  a  reddish  brown      '^^fLd  matter  ^hm^lS^" 

trelt:d  "ad^Y; rS"""  '"'  """""'"^  '=»'""'"«'"'  "'  *"  -'•  -d  U  to  be 


,  J- 


692 


SOILS,  ANALYSIS  OP. 


1 1 


^hiskey  (11  per  cent,  overproof).  The  whole  sulphate  of  lime  will  be  now  separated 
from  the  fluid,  and  after  being  drained  on  a  filter,  may  be  dried,  ignited,  and 
weighed.  ''  »    o         » 

For  determining  the  alkaline  salts,  the  water  filtered  from  the  100  grains  of  the 
BoU  should  be  evaporated  down  to  one-fifth  of  its  bulk,  and  then  treated— Ist,  with 
nitrate  of  barytes,  for  the  sulphates;  2d,  with  nitrate  of  silver  for  the  muriates:  3d, 
with  oxalate  of  ammonia,  for  the  nitrate  or  muriate  of  lime  (provided  no  sulphate  of 
;\?®  18  indicated  by  the  first  test);  4th,  with  litmus  paper,  for  alkaline  or  acid  reaction  ; 
oth,  with  soda-chlonde  of  platinum  for  potash  salts,  which  are  very  valuable  for  the 
growth  of  many  plants. 

The  portion  of  soil  tested  for  potash  salts  should,  before  being  digested  in  water  be 
gently  calcined,  to  insure  the  expulsion  of  ever^  particle  of  ammoniacal  salt,  otherwise 
the  precipitate  afforded  by  soda-chloride  of  platinum  would  be  fallacious. 

Another  peculiar  research  of  great  importance  is  that  which  determines  the  amount 
of  ammonia  in  a  soil ;  and  which  may  exist  either  ready  formed,  or  in  its  elements, 
capable  of  affording  a  portion  of  the  azotic  food  so  indispensable  to  vigorous  vegetation. 
The  actual  ammonia  is  easily  obtained  by  distilling  the  soil  along  with  some  "milk  of 
lime.  The  distilled  water  will  contam  all  the  volatile  alkali,  which  may  be  measured 
by  the  number  of  drops  of  a  standard  dilute  acid  which  it  will  saturate. 

The  ;)0<cn<ia/  ammonia,  slumbering,  so  to  speak,  in  its  embryo  elements,  may  be 
estimated  by  igniting  200  grains  of  the  soil  with  its  own  weight  of  a  mixture  of  hydrate 
of  soda  and  quicklime,  as  described  in  my  memoir  on  "  Guano,"  in  this  work. 

I  have  subjected  the  soil  of  Dr.  Kerrison's  farm  to  the  various  modes  of  research 
above  enumerated,  and  have  obtained  the  following  results : — 

1.  By  the  application  of  my  limestone  meter  I  obtained  carbonic  acid  gas,  equivalent 
to  9  grains  of  carbonate  of  lime. 

2.  By  igniting  200  grains  of  the  soil  along  with  2Q0  grains  of  mixed  quicklime  and 
hydrate  of  soda,  in  the  appropriate  apparatus,  I  obtained  0  34  grains  of  ammonia,  or 
017  per  cent  of  the  weight  of  the  soil  Hence,  600  grains  of  the  soil  contain  the 
azotic  equivalent  of  one  grain  of  ammonia.  This  remarkable  fact  reveals  most  plainly 
one  secret  source  of  the  uninterrupted  production  of  rich  crops  of  cereals  and  other 
plants  from  it,  without  receiving  any  manure.  How  appropriate  to  such  land  is  Vir- 
gil's beautiful  title  of  the  subiect  of  his  ••  Georgics,"  ?'w«<i«»iwa  tellus  ! 

3.  By  the  process  of  cohobation  for  8  hours,  with  dilute  muriatic  acid,  as  also  by  the 
process  of  fusion  with  the  alkalis  in  a  platinum  crucible,  and  the  subsequent  treatment 
above  detailed,  I  obtained— 


1.  Sih'ca     •  • 

2.  Alumina  .... 

3.  Oxide  of  iron     .... 

4.  Carbonate  of  lime  ... 
6.  Sub-phosphate  of  lime  -  -  - 

6.  Magnesia  (carbonate)     ... 

7.  Moisture  separable  by  steam-heat 

8.  Organic  matter,  chiefly  vegetable  mould 

9.  Moisture  separable  at  a  red-heat 


660 
80 
6-6 
90 
0-4 
0-5 

11-3 
6-6 
2-7 


1000 


besides  traces  of  muriate  of  soda,  and  muriate  of  lime  (chlorides  of  sodium  and 
calcium).  The  iron  exists  mostly  in  the  state  of  protoxide,  a  circumstance  owing, 
probably,  to  exhalations  from  the  subsoil  of  sulphuretted,  phosphuretted,  and  car- 
buretted  hydrogen.  The  fresh  soU  is  of  a  grey  colour,  but  becomes  ochrey-red  by 
calcmation.  "^ 

100  grains  of  the  said  soil,  dried  at  212°,  absorb  8  grains  of  moisture  in  24  hours; 
while  100  grains  of  the  comparatively  sterile  soil  of  Regent's  Park,  dried  equally) 
absorb  only  6  grains ;  a  difference  due  chiefly  to  the  finer  comminution  of  the  former. 

Since  the  phosphates  are  such  precious  ingredients  towards  fertilizing  soils,  it  \g 
desu-able  to  possess  a  clear  and  simple  test  of  their  presence.  For  this  purpose  digest 
tlie  soil,  for  an  hour  or  so,  with  a  moderate  heat,  in  dilute  nitric  acid,  free  from 
muriatic  (viz.  which  affords,  when  largely  diluted,  no  precipitate,  by  the  addition  of 
a  solution  of  nitrate  of  silver).  Throw  the  mixture  on  a  filter,  and  to  the  filtered 
liquid  add  potash-water,  cautiously,  till  the  instant  that  a  precipitate  begins  to  appear ; 
then  drop  into  it  a  weak  solution  of  nitrate  of  silver.  If  any  phosphoric  salts  be 
present,  a  yellowish  precipitate  will  immediately  fall,  which  is  re-soluble  in  an  excess 
of  nitric  acid.  Whatever  is  not  thus  dissolved  is  chloride  of  silver,  and  ought  to  be 
■eparated  by  filtration.    On  adding  then  weak  water  of  potash  (not  ammonia)  cautiously 


SOILS,  ANALYSIS  OF.  gg^ 

J^iJon'pSrihVh^^^^^^^^  will  be  obtalnad,  without  any  alumina 

membered  that  chloride^  oFsLrfLlbtrj^^^^^  ^\  ^"^*  *«  ^  '«* 

of  the  phosphate  of  silver  -nirnor^on  S  J^^'*' ^Y^JjP^^  quite  different  from  that 
and  not  cafaned,  b^use  th?  X  i  .  ^  ^^  "'^^.*''  ^'^  experiment  should  be  fresh 
•alts  of  silver.  The  s^^onge'  tT^^^^7Tt^''t'  f  ^^^  ^?'*^  precipitates  wiS 
more  characteristic  is  the  y^bw  predD^tete  wfth  dl  P^^«P^«"^  «^'»«  compound  is.  the 
for  eff«.ting  the  partial  JurSof  tC^^  niay  be  used 

lent  re-agent  for  detecting  DhosnhonV  aoiS  on?  /  Sulphate  of  magnesia  is  an  excel- 
•olution7when  it  is  Sl^  reSrI  LT^fi?  **'  ^^P^rating  it  from  the  above  acid 
the  phosphoric  acid  Cd  arifmon^^^^^^^  '  ^^'  "^^  "^^^^'^^  ^^^^  ^ith 

nesian  phosphate.  A  soludrTsulnh.f^nf  ^  ^ •""'*'  precipitate  of  ammonia-mag- 
JB  probably'the  best  tes  Sof  fo^S^^^^^^  *  ^'"^^  8al-ammonia| 

better  in  niutral  solutions^  ^'"^  phosphates  m  fiiintly  acidulous,  but  still 

4'-rof  -Ica^r L:^^^^^^^^^^^  this  country,  there  is  a 

with  alumina  or  oxide  of  irS  w^Si  reZn  i^l,^^^^  °1  phosphoric  acid 

cultural  analysis  to  search  for  ph^hatLTa^^^^^^^^^  '^^  f '  '^'^^^^^  ''  -^- 

often  associated  with  iron  it  exists  in  frv.  Tr«oii  5-  '**"*      ^^  ^^^  manganese, 

little  value,  to  make  it  wirth  whie  to  effeotT«  L^  P^^^^^^^' «»d  "  possessed  of  t<^ 

expenmint),  gives   the    quantft^'T  o'r^'nif'mi^^^^^^  Its^Talit'""  T^^^Venl^^ 
th^e^ultimate  analysis   by  mean^s  of  hyTrate  ^tSa   a^^d  ^tlU^, t^Tvt^j:    • 

.cMrpS:^^^  ignited  soil   in   nitric 

^^^i^aTidT^t^-^  Z'Z  ^"^lOF^^^f  -^^ai  i?trr 
nitric    acid,   decompose    the    sLtlwifh^^'*"^^  I>igest  in 

inixture  upon  a  filteJ,  and  weSh  ^e  srinLfift^^S  ^''^'-  .^^^ ,  alcohol,  throw  the 
this  weighMhat  of  the  oxil  ?f  U^A  ^^  ?^  ^^^^  remaining  left  upon  it  From 
contain  112  of  oxide  Z  nnL  t  ^"^Tx'  ^.°«^°.;  «i"ce  152  of  sulphate  of TiS 
in  apother  equal  portion  ofthTtTU^  '"i^''!!"^  *?^  ^*^°°^   ^J  ^^^^^  of  ^ryt^ 

n^ea^nstf  ThTstSf-chS  o^f'  fit  ''?lif  S^"  ^'  ^"^^  \^  ^^^  <»-%  by 
«nine  the  quantity  of  that  impoK  aTkali  as  weU  iVl^^  1*^*?^^  ^  ^^^^'^ 
•oil  m  hydrochloric  acid  is   to   V«    troaSS      tu  I  ^^  ^^^     ^«   solution  of  the 

reddened  litmus  papT  t  il  then  hfff^  ^'^}  ^^^'^  ^a*«'  ^^^  the  hquid  blue! 
the  whole  of  the^sSf^hu  c  anS  ph,^^^^^^^^^^^^  "Pon  a  filter.     By  ^s^^^l 

n.agnesia..and  the  lim^e  that  was^cZw"  S  w  th  'tlTe  ph'^snh  '^'  °^i?^°'  '^"^  *»>« 
The  precipitate  is  to  be  washed  till  the  wallr  l^  I  Phosphoric  acid,  is  separated, 
by  nitrate  of  silver     To  the  rW  i:  f    7^^^^   P*®^»  ^^ases  to  be  affected 

w^th  caustic  ammonia  is  \o  MrtoXl'^ow''  T*^^*?  ^'  ammonia  mtel 
is  to  be  left  in  repose  for  a  Httl^fni  -      ^7   ^""^^  *"   ***«   barytes.     The  whole 
be  thrown  upon  a  fi^e"  and  washed     ke  lltrerir^'P^'*'  '^"«'  ^"^  ^'  '^  ^^^'o 
the  residuum  is  to  be  ignited  in  a  platinum  orlT     ^"^"«^^'nff  evaporated  to  dryness, 
when  it  can  contain  oX  thralkalfne  m...^      T  ^^P'"^^'  ^  expeVall  the  amSo^ 
chlorides.    After  being'UXd.'ft  is  tr^^^^oS"^  '"^  ""^r?  ^°  '^'  «**  "^ 
trace   of  magnesia  miy  appear    (which  Sn   iT   r    •'^^''^''^  ^"^«  "^^^'^  when  a 
amount  of  potash  is  to^be^eSimatlr  rL  the^eilT'n^^^^  ^^  ^^i^^^^^'    ^^   '^ 
•oda-chloride  of  platinum.     The  differenc^  „f  t^o^   •  l[  *^^  P'^^P'tate  produced  by 
of  that  corresponding  to  the  potash  ius^LnV^  "^T^*  **^  ^^^  ^^°^«  ^"oride  an3 
and  of  course  ^soda  in  the  b^        ^  """^  ^'^^  ^^^  ^l"*"^'*^  of  sodium  chloride, 

of^SX^fn^^^^  ;«JHe  p^ss  of  uniting  the  surfaces 

surface,  serves,  partly  hy  chemical  attracUo^^'d^  ^^  ^,^ ^h^^f  .^^^^  ^^  -^ 


694 


SOY. 


I  .- 


together.  The  metals  thus  united  may  be  either  the  same  or  dissimilar ;  but  the  uniting 
metal  must  always  have  an  affinity  for  both.  Solders  must  be,  therefore,  selected  m 
reference  to  their  appropriate  metals.  Thus  tin-plates  are  soldered  with  an  alloy  con- 
sisting of  from  1  to  2  parts  of  tin,  with  1  of  lead ;  pewter  is  soldered  with  a  more  fusible 
alloy,  containing  a  certain  proportion  of  bismuth  added  to  the  lead  and  tin ;  iron,  copper, 
and  brass  are  soldered  with  spelter,  an  alloy  of  zinc  and  copper,  in  nearly  equal  parts ; 
silver,  sometimes  with  pure  tin,  but  generally  with  sUver-solder,  an  alloy  consisting  of 
5  parts  of  silver,  6  of  brass,  and  2  of  zinc  ;  zinc  and  lead,  with  an  alloy  of  from  1  to  2 
parts  of  lead  with  1  of  tin ;  platinum,  with  fine  gold  j  gold,  with  an  alloy  of  silver  and 
gold,  or  of  copper  and  gold  ;  &c. 

In  all  soldering  processes,  the  following  conditions  must  be  observed ;    1.  the  surfaces 

to  be  united  must  be  entirely  free  from  oxyde,  bright,  smooth,  and  level ;    2.  the  contact 

of  air  must  be  excluded  during  the  soldering,  because  it  is  apt  to  oxydize  one  or  other 

of  the  surfaces,  and  thus  to  prevent  the  formation  of  an  alloy  at  the  points  of  union. 

This  exclusion  of  air  is  effected  in  various  ways.    The  locksmith  encases  in  loam  the 

objects  of  iron,  or  brass,  that  he  wishes  to  subject  to  a  soldering  heat ;  the  silversmith 

ajid  brasier  mix  their  respective  solders  with  moistened  borax  powder ;  the  coppersmith 

and  tinman  apply  sal  ammoniac,  rosin,  or  both,  to  the  cleaned  metallic  surfaces,  before 

using  the  soldering-iron  to  fuse  them  together  with  the  tin  alloy.     The  strong  solder  of 

the  coppersmith  consists  of  8  parts  of  brass  and  1  of  zinc  ;    the  latter  being  added  to  the 

former,  previously  brought  into  a  state  of  fusion.    The  crucible  must  be  immediately 

covered  up  for  two  minutes  till  the  combination  be  completed.    The  melted  alloy  is  to 

be  then  poured  out  upon  a  bundle  of  twigs  held  over  a  tub  of  water,  into  which  it  falla 

in  granulations.     An  alloy  of  3  parts  of  copper  and   1  of  zinc  forms  a  still  stronger 

solder  for  the  coppersmiths.     When  several  parts  are  to  be  soldered  successively  upon 

the  same  piece,  the  more  fusible  alloys,  containing  more  zinc,  should  be  used  first.     A 

soiler  solder  for  coppersmiths  is  made  with  6  parts  of  brass,  1  of  tin,  and  1  of  zinc ;  the 

tin  being  first  added  to  the  melted  brass,  then  the  zinc ;  and  the  whole  well  incorporated 

by  stirring. 

The  edges  of  sheet  lead  for  sulphuric  acid  chambers,  and  its  concentration  pans,  arc 
joined  together  by  melted  lead  itself,  because  any  solder  containing  tin  would  soon  be 
corroded.  With  this  view,  the  two  edges  being  placed  in  contact,  are  flattened  down 
into  a  long  wooden  groove,  and  secured  in  their  situation  by  a  few  brass  pins  driven 
into  the  wood.  The  surfaces  are  next  brightened  with  a  triangular  scraper,  rubbed  over 
with  candle  grease,  and  then  covered  with  a  stream  of  hot  melted  lead.  The  riband  of 
lead  thus  applied  is  finally  equalized  by  being  brought  into  partial  fusion  with  the  plum- 
ber's conical  iron  heated  to  redness ;  the  contact  of  air  being  prevented  by  sprinkling 
rosin  over  the  surface.  The  sheets  of  lead  are  thus  burned  together,  in  the  language  of 
the  workmen.  • 

SOLDERING  OF  LEAD,  cuid  other  metals,  is  called  by  ita  inventor,  M.  de  Richemont, 
autogenioua,  because  it  takes  place  by  the  fusion  of  the  two  edges  of  the  metals  them- 
selves, without  interposing  another  metallic  alloy,  as  a  bond  of  union.  He  eflFects  this 
purpose,  by  directing  a  jet  of  burning  hydrogen  gas,  from  a  small  moveable  beak,  upon 
the  two  surfaces  or  edges  to  be  soldered  together.  Metals  thus  joined  are  much  less  apt 
to  crack  asunder  at  the  line  of  union,  by  differences  of  temperature,  flexure,  dec,  than 
when  the  common  soldering  processes  are  employed.  The  fusing  together  the  edges  of 
lead  sheets,  for  making  sulphuric  acid  chambers,  has  been  long  practised  in  this  country, 
but  it  was  performed  by  pouring  some  of  the  melted  metal  along  the  line  of  junction,  and 
afterwards  removing  its  excess  by  means  of  a  plumber's  soldering  iron.  The  method  of 
M.  Richemont  is  a  great  improvement  upon  that  old  practice.  It  is  much  quicker  and 
more  convenient. 

SOOT  (JVbtr  defun^e,  Suie,  Fr. ;  Jius,  Flatterrus,  Germ.)  ;  is  the  pulverulent  charcoal 
condensed  from  the  smoke  of  wood  or  coal  fuel.  A  watery  infusion  of  the  former  is  said 
to  be  antiseptic,  probably  from  its  containing  some  creosote. 

The  soot  of  pitcoal  has  not  been  analyzed  with  any  minuteness.     It  contains  some  sul- 
phate and  carbonate  of  anmiouia,  along  with  bituminous  matter. 
SORBIC  ACID,  is  the  same  with  malic  acid ;  which  sec. 

SOY,  is  a  liquid  condiment,  or  sauce,  imported  chiefly  from  China.  It  is  preparer 
with  a  species  of  white  haricots,  wheat  flour,  common  salt,  and  water ;  in  the  propor- 
tions respectively  of  50,  60,  50,  and  250  pounds.  The  haricots  are  washed,  and  boiled 
in  water  till  they  become  so  soft  as  to  yield  to  the  fingers.  They  are  then  laid  in  a  flat 
dish  to  cool,  and  kneaded  along  with  the  flour,  a  little  of  the  hot  water  of  the  decoctioa 
being  added  from  time  to  time.  This  dough  is  next  spread  an  inch  or  an  inch  and  a 
half  thick  upon  the  flat  vessel  (made  of  thin  staves  of  bamboo),  and  when  it  becomes  hoi 
and  mouldy,  in  two  or  three  days,  the  cover  is  raised  upon  bits  of  stick,  to  give  free  access 
of  air.  If  a  rancid  odor  is  exhaled,  and  the  mass  grows  green,  the  process  goes  on  wellj 
but  if  it  grows  black,  it  must  be  more  freely  exposed  to  the  air.    As  soon  as  all  the  sor* 


SPINNIJ^G.  595 

ftce  IS  covered  with  green  mouldiness,  which  usually  happens  in  eignt  or  ten  days,  the 
SI  W  ''"'''''k'!.''^  ^^'  °^*""'*  ^^  P^*^^  i»  t^«  ««»«hine  for  several  davs     When  il 

J^se^  andVover^d  wltVt^^^^^^  ^'  T  f'""  ^^"  ^^«^°^^"^«>  ^^^^  info  an  eaAheS 
wholhr.drrpH  toiThl  %^  r"1^'  ""^  '^**^''  ^*^^"S  the  salt  dissolved  in  it.  The 
h^inl  nl«!2;  f  ^T  ^^''  "^""^  *^^  ^^'-^^  *'  "^^'^^  'he  water  stands  is  noted.    The  vessd 

Jjieffs  a^lildi^^^^^^^^  "P^^^^y  "^^'•^"S  ^^^  evening;  anl!^ 

cover  IS  applied  at  night,  to  keep  it  warm  and  exclude  rain.    The  more  nowprfnl  thm 

•ni  »kI  ^-  5  "?"'"s- .  -As  the  mass  diminishes  by  evaporation,  well  water  is  added  • 
and  the  digestion  i.  continued  till  the  salt  water  has  dissolved  the  whole  Tf  the  flourTnd 
the  haricots ;  after  which  the  vessel  is  left  in  the  sun  for  a  few  da7s!  as  the  r^  ouamv 

.tiri?n/'^WHP'">\""  '^"  ^TP^^^""^^^  «f  '^'  ^«^"tion,  whichTpromoted^^rrJiJ 
stS  ^tlil  h\^^V^"?th  assumed  an  oily  appearance,  it  is  poured  nto  ba^:^ 
strained.    The  clear  black  liquid  is  the  soy,  ready  for  use.    It  is  not  boiled  h..f  ,«  nnt  n« 

SPARRY  IRON  ORPTI,?        """"  ''f-^'?^'"V0/ Science,  of  Stockholm  [or  1803. 
.Ja.u  ■  ■■       ™^  'P"'y  '""■  <"■«  '5  '^««<'  fof  the  manufacture  of  oie  iron 

and  changes  m  roasting  into  magnetic  ironstones,  discernible  by  theTvS  The  m^' 
f«ture  of  iron  mto  bars  by  mean,  of  gas,  is  but  in  its  infanc/;  butX  iron  pT^du^ta 

^rSn  •'  "-""if  «<» '»  be  preferable  to  that  produced  by  means  of  XiS^^  to 
thepuddled  iron  in  bars  made  by  pitcoaL  wiaicom,  ana  w) 

Jrnn  ^i!'^'*^^  •**(  ^"""^^^y  »^a^«  no*-  teen  found  favourable  to  the  production  of  ^ood 
iron ;  the  prmc.ple  has  therefore  been  introduced,  of  distilling  the  fueTScC  vJ^ 
and  usmg  the  resulting  gases,  in  a  state  of  combustion  in  the  furnace  aa^  SHou^  of 
^^^  ^  J?,^^  ''*°°-  J^^  '■^^"^'«'  ^'  ^^'  ^'  *^^  experiment  has  yet  S'trTed  are  sat^f^ 
r^^tive  vatVo7  ?L^T  ^'^f^'''^  e-tendingy the  iron  distrits  of  the  ContTneut  'S^ 
ret^Tob^^^^^^^^  '''''''  ''  ^"^P«  "^^y  ^  -f-«<^  fro-  the  following 


£ 
2.000,000 
502,000 
448,000 
400,000 
800,000 
190,000 
150,000 
145,000 
76,000 


Great  Britain  -  -  . 

United  States  -  -  -  . 

France  -  -  . 

Russia  -  -  -  »  . 

Prussian  Zolverein    -  -  .  I 

Austria         •  •  -  -  . 

Belgium        ....  * 

Sweden  -  -  .  .  . 

All  the  other  European  States  -  -  /e  uw 

.a^^hlJil^^^h,?^^^?^;  designates  the  relative  weights  of  different' bodies  under  the 
fame  bulk ;  thus  a  cubic  foot  of  water  weighs  1000  ounces  avoirdupois ;  a  cubic  foot  of 
coal,  J350  ;  a  cubic  foot  of  cast  iron,  7280 ;  a  cubic  foot  of  silver,  10  400  •  and  a  cnW* 
foot  of  pure  gold,  19,200 ;  numbers  which  represent  the  specific  gravi^^^^ 
substances,  compared  to  water  =  1-000.     See  Alloy.  S'^aviiies  oi  ine  respecUve 

SPESMArPT^^tT^kJ-  ^""fnJ  ''^'?P%'  ^"'^  *^"'  ^^<^'^^  "nder  Copper. 
•I.O  PA     7  '    \  F^^'"^  °r  Chevreul.    In  certain  species  of  the  cachalot  whale  ai 

the  Physeter  macrocephalus,  ursio,  mtcrop,,  and  orthodon,  is  also  the  Delph^us  S«zJ? 

eed      Th/r^r-'' JV'^"^'^  "^^'^  ^°"^*^"^  *  peculiar' kind  of  stLriuVcaHeJ^r^^ 
thJ'riJ  f  ?»' ??>tamed  from  cavities  in  the  bones  of  the  cranium  of  the  above  ceS?^ 
the  richest  m  this  kind  of  stearine.     This  being  thrown  into  great  filter-Ws  the  ^r 
maceti  oil  i>asses  through,  and  s  subsequentlv  nurified  bv  thP^.i^uLr!  ^r-        i.       ^ 
of  potash  ley,  which  precipitates  certain  i^K  by  t^rin^^^^^^^^^ 
in  solution.     The  solid  which  remains  on  the  filter  "rnSt  ^u\ez^^^^^^  hie  k       ^" 

m^^^t::^\^^b^e:,^rTs^,T^it^  r„zr'  ^^ »"-- »« cooiing.  wh.. 

the  eeUrn  of  Chevreul,  or  pure  SMraTace  i     I  ,t°  ."'^"  '•  «?<•"«'')'.«''««  ■'•""ins  « 
msd  its  hoilinir  noini  Bi«.  p    ..  »i- V  *!  j-    ..'  ■»«'•">«  Pomt  has  now  become  llfi»  F- 

J^s';a^l^"1twi?M*tt  '^""  "*""'  •"*""""••    *'•"'"'=  •"^« 

SPINNING.    The  greatest  improvement  hitherto  made  in  formine  textile  fabri«L 

•mce  the  era  of  Arkwright,  is  due  to  Mr.  G.  Bodmer.  of  Manchestef.    ByL^iS 


996 


SPINNING. 


waa  obuined  m  1»24'  *"J  ?"  „eriS  rf  14  Teare  was  expired.  It  contained  the 
Council,  for  7  ye^  '^" ^  ^^^  fibr«  oflotton,  flax,  &c.,  were  Upped  and 
fcrt  development  of  a  P'»^J'T''''S%°?2'  ,nd  blomng,  cardii«,  drawing,  roving, 
nnlapped  through  aU  the  opemtwns  of  deam^^^^  ^S,^^^^  ^j.  ^^^^._^  .^ 

:^rTh^e^rppturth''e=°^.jnnot^j^.^ 


Patent  of  1835. 
«.     1  «j     TT.*.  mrthod  aDDlied  through  aU  the  foDowing  operations  ^  th» 

Vl^:^'^  '^^T^  SrUU^^ma,  WS38.  lia  18«.  of  Mr. 

Botliner.  „        ,,  ,  .  „„;,  .,  Onener  ("  Wolf,"  in  German),  which 

By  .  roachine  g'"!™"^  .''^I'f  »  ?7„'J  a  roUer  covered  with  spikes  (see^g.  1828) 

rro;'sstertrurhe'a^|:^g^^^^^^^ 
rp^irn:,rd°'sp"j^ruVVsrKri^;srfjh^'^^ 

behind  the  first  blower.  without  teeth,  and  over  this  plate  the 

The  first  blower  has  a  feeding-plate  Uke^g.^^^^^^  .^  .    ^  ^^^^^^^ 

cotton  is  delivered  to  the  operation  of  the  common  b^s,  irom  wui 


Paiwi  of  1835. 


Patents  of  1824  and  1835. 


«to  a  narrow  compartment  of  4|  or  5  inch..  ,^-^' «j^^^^^^^^^^^  lu^Z 

machines,  upon  rollers  in  beautifully  level  ^.^^  well-cleaned  lap^^^^S^       ^^  ^^^ 

narrow  laps  are  then  placed  behind  a  ^f^^f^^^^^S.^^'^^f,^^^^^  edges  is 

first.    Instead  of  the  common  beater,  »^°^«^!.^[>  ^^^^^^^  the  fibres  from  on© 

ased  (see/ig.  1824),  which  opens  the  cotton  still  more,  and  separates  ui 


SPINNING. 


69T 


toother.  The  cotton  is  again  formed  into  similar  narrow  laps,  which  arc  still  more 
equal  than  the  preceding  ones,  and  eight  of  these  laps  are  then  placed  behind  the  carding 
engines.  It  was  only  by  applying  his  lap-machine,  patented  in  1842,  that  he  succeeded 
In  forming  small  laps  on  the  blower;  without  this  he  could  not  perform  the  doffing  of 
the  laps  without  stopping  the  wire-cloth,  and  in  doing  this,  an  irregular  lap  would  be 
formed  because  of  the  accumulating  of  the  falling  cotton  in  one  place  while  the  wire- 
cloth  was  standing. 

Carding  Engine.— His  patent  of  1824  showed  a  mode  of  coupling  a  number  of  carding 
engines,  the  product  of  which  was  delivered  upon  an  endless  belt  or  a  trough,  and  at 
the  end  of  this  trough  was  wound  upon  a  roller.  This  arrangement  Awants  no  description, 
•8  it  is  generally  known.     I  have  seen  it  in  use  on  the  Continent. 

When  a  set  of  cards  work  together,  any  interruption  or  stoppage  of  a  single  carding 
engine  causes  a  defect  in  the  produce  of  the  whole  lap.  Interruption  occurred  several 
times  a  day  by  the  stripping  of  the  main  cylinder,  and  during  this  operation  the 
missing  band  or  sliver  was  supplied  out  of  a  can,  being  the  produce  of  a  single  carding 
engine  working  into  cans  (a  spare  card).  The  more  objectionable  defect  was,  however, 
the  difference  of  the  product  of  the  carding  engine  after  the  main  cylinder  had  been 
•tripped  ;  the  band  or  sliver  from  it  will  be  thin  and  light  until  the  cards  of  the  main 
cylinder  are  again  sufficiently  filled  with  cotton,  when  the  band  will  again  assume  its 
proper  thickness.  Another  irregularity  was  caused  by  the  stripping  of  the  flats  or  top 
cards,  but  was  not  so  fatal  as  the  first  one.  These  defects  were  of  course  a  serious 
drawoack  in  his  system  of  working,  the  latter  of  which  he  provided  against  in  his  first 
patent  by  stripping  the  top  cards  by  mechanism ;  the  former,  however,  was  only 
conquered  by  Us  invention  of  the  self-strippers  for  the  main  cylinders;  thus  the 
carding  engine  may  now  work  from  Monday  morning  till  Saturday  night  without 
interruption,  the  cylinders  requiring  only  to  be  brushed  out  every  evening;  the  coiir 
sequence  is,  that  much  time  is  gained,  and  a  very  equal,  clean,  and  clear  product  is 
obtained.  Old  carding  engines  to  which  he  applied  his  feeders  (see ^g.l325).and  main 
cylinder-clearers  produce  much  superior  work,  and  increase  the  production  from  18  to 
24  per  cent. 

The  main  cylinder-clearer  consists  of  a  very  light  cast  iron  cylinder  upon  which 
five,  six,  or  more  sets  of  wire  brushes  are  fixed,  which  are  caused  to  travel  to  and  frc 
across  the  main  cylinder ;  the  surface  or  periphery  of  the  brushes  overrunning  the 
surface  or  periphery  of  the  main  cylinder  by  8  or  10  per  cent.,  the  brushos  thus  lifling 
the  cotton  out  of  the  teeth  of  the  cards  of  the  main  cylinder,  and  causing  the  dirt  and 
lumps  to  fall. 

As  the  brushes  are  not  above  a  quarter-inch  in  breadth,  and  travel  to  and  fro,  it  is 
clear  that  no  irregularity  can  take  place  in  the  fleece  which  comes  from  the  doffer; 
not  more  than  1  40th  part  of  the  breadth  of  the  cylinder  being  acted  upon  at  the  same 
time.    Figs.  1326,    1327.  give  an  idea  of  the  clearer :  the  mechanism  within  the  clearer, 


1325 


Patents  of  1838  and  1842. 

ind  by  which  the  brushes,  a,  are  caused  to  travel,  is  simple  and  solid.  The  mam 
cylinders  for  the  carding  engines  are  made  of  cast  iron,  the  two  sets  of  arms  and  rim 
are  cast  in  the  same  piece ;  when  complete,  they  weigh  50  lbs.  less  than  those  made  of 
wood. 


698 


SPINNING. 


Th«  new  lap  machine  connected  with  these  engines  is  almost  self-acting ;  a  girl  haf 
only  to  turn  a  crank  when  the  lap  is  full ;  by  this  turn,  the  full  lap  is  removed  and  an 
empty  roller  put  in  its  place,  the  band  of  cotton  is  cut,  and  no  waste  is  made. 

Drawing  Frame. — The  drawing  frame  of  1824  was  improved,  and  the  improvements 
patented,  in  1835,  and  others  again  in  1842.  That  of  1824  is  known  in  Germany  and 
France,  and  generally  in  use.  The  laps  from  the  carding  engine  lap-machine  are  put 
upon  delivering  rollers,  behind  a  set  of  drawing  rollers,  and  from  them  delivered  upon  a 
belt  or  trough,  and  again  formed  into  laps  similar  to  those  from  the  carding  engines. 
The  next  operation  formed  the  laps  into  untwisted  rovings,  and  the  next  again  into 
umaller  untwisted  rovings,  or  rovings  with  false  twist  in  them,  as  infringed  upon  by 
Dyer.  The  false  twist  was  rather  objectionable,  and  in  his  patent  of  1835  he  put  a 
number  of  rovings  on  the  same  bobbin,  with  left  and  right  permanent  twist  in  them. 
This  does  very  well;  there  is,  however,  a  little  objection  to  that  place  in  which  the 
twist  changes  from  right  to  left  when  it  comes  to  the  last  operation  before  spinning. 
In  his  patent  of  1838,  and  particularly  in  that  of  1842,  he  confined  the  left  and  right- 
hand  twist  to  the  drawing  frame,  when  he  converts  two  laps  into  one  roving,  and  forms  a 
roller  or  bobbin  of  14  inches  diameter  and  15  inches  broad,  with  six  separate  and  twisted 
rovings  wound  upon  it.  {See  Jigs.  1328.  and  1329.)  The  twist  is  given  by  tubes  in  two 
directions,  so  that  it  remains  in  it  (see  ^g.l329),  the  tube  turns  in  the  same  direction, 
while  the  roving  advances  4  or  5  inches,  and  then  turns  in  the  other  direction.  These 
laps  or  bobbins  are  then  placed  behind  a  machine,  which  he  calls  a  coil-frame,  the  most 
important  arrangement  of  which  he  claimed  already  in  his  patent  of  1835.  It  consists 
of  a  slot  with  a  travelling  spout,  without  which  the  coils  can  not  be  formed  under  pres- 
sure. Coiling  in  cotton  can  not  be  claimed,  as  it  was  done  in  the  first  system  of  cotton 
spinning. 

Coil  Frame.— The  bobbins  (^g.l328),  are  placed  behind  this  machine,  and  two  ends 
from  the  bobbin  are  passed  through  the  drawing  rollers  and  formed  into  one  untwisted 
sliver  or  roving  in  the  following  manner :  When  the  cotton  has  passed  through  the 
drawing  rollers  (see  ^g.  1330),  and  calender  rollers.  A,  it  is  passed  through  the  tube,B, 
ind  the  finger,  C ;  the  spindle  with  its  disc,  D,  revolves  in  such  a  proportion  as  to  tak« 
up  the  cotton  which  proceeds  from  the  calender  rollers.  A,  and  cause  the  rovinpi  .o  be 
laid  down  in  a  spiral  line  closely  one  by  one,  and  as  the  rollers.  A,  work  at  a  "regular 


1328 


1329 


Patents  of  1835,  1838,  and  1842, 
•peed,  it  is  evident  that  the  motion  of  the  finger,  C,  and  the  speed  of  the  tube,  B,  must 
vary  accordingly.  The  coil,  E,  is  stationary,  and  is  pressed  by  the  lid  or  lop,  F,  which 
slides  up  the  spindle,  G,  made  of  tin  plate.  The  cotton  enters,  through  the  slot,  X,  in 
M'  D-     It  IS  quite  evident  that  the  finger,  C,  and  spindle,  G,  only  perform  one  and  the 

?Zf  hpr'^'^r  ^"1;''?«*'-  ^V^P««^^^.^'  ^""^'^  ^'^'^  ^^5^^^'  «"d  the  coil  is  thus  built 
from  below;    t  is  about  8  inches  m  diameter  and  18  inches  high  when  compressed 
and  contains  4|  lbs.  of  cotton.     Mr.  Bodmer  has  several  modes  of  farming  th^secoSs' 
but  one  only  is  shown  here.     These  coils  are  placed  behind  the  twist  coil  frImesTn  hatf 

^^on  TnK^  T\  ''''•?  « Vf ''"^J''  ?^  ^^^^"^  *  ^^"'^^'^S  machine,  where  they  are  wound 
upon  rollers  side  by  side,  like  the  lap  or  bobbin  shown  in  the  drawing  frame  and 
placed  behind  the  twist  coil  frame  in  this  state.  urawing  irame,  ana 

TtTM^  C(n7£rarne.-This  frame  forms  rovings  into  coils  simUar  to  those  above 
explained,  with  this  diflerence,  that  the  rovings  are  fine,  say,  from  1  to  10  hanks  per 
pound,  and  regularly  twisted :  their  diameter  varies  from  2|  to  5  inches.  The  saL« 
machine  produces  rovings  more  or  less  fine,  but  the  diameter  of  the  coils  does  not  differ. 


i 


SPINNING. 


699 


■ntmnnjk 


Patents  of  1838  and  1842. 


-88-8 


Paindi  of  1838  awi  1842. 


The  difference  of  this  machine  from  that  above  described  consists  in  the  dimensions  of 
their  parts,  and  in  its  having  the  spindle,  o,  and  the  lid  or  top,  f,  revolving,  as  well  as 
the  tube,  b.  (See  Jig.  1331.)  In  this  machine  the  motion  of  the  spindle,  b,  is  uniform :  the 
spindle,  o,  however,  is  connected  by  the  bevel  wheels  h  and  i,  with  a  differential  motion 
at  the  end  of  the  frame,  with  which  the  motion  of  the  finger,  c,  corresponds.  The  skew 
wheels,  k  and  l,  are  connected  with  the  drawing  rollers,  a.  The  speed  of  the  tube,  b, 
and  the  spindle,  g,  are  so  proportioned,  that  while  the  spindle,  g,  performs  one  revolution, 
and  therefore  puts  one  twist  into  the  roving,  the  tube,  b,  also  performs  one  revolution, 
missing  so  much  as  will  be  required  to  pass  through  the  slot  in  the  cap  or  disc,  d,  and 
lay  on  it  as  much  of  the  roving  as  proceeds  from  the  rollers,  a,  and  in  which  one  twist 
is  contained.  Of  course  the  twist  of  these  rovings  can  be  adapted  to  their  fineness  aud 
varied ;  but  it  is  evident  that,  on  account  of  the  regularity  of  the  machine  and  its  sim- 
plicity of  movement,  the  rovings  can  never  be  stretched,  and  much  less  twist  can  be  put 
into  thera  than  can  be  put  in  the  common  fly  frames.  These  coils  are  put  behind  the 
spinning  machines  on  shelves  or  in  small  cans,  open  in  front ;  or  they  are  wound  from 
24  to  72  ends   upon   bobbins,   and   placed   upon   unlap  rollers   behind  the  spinning 

frames. 

Coifing  Machine  for  Cardina  Engines  and  Drawing  Frames. — These  are  simple 
machines,  which  may  be  applied  to  carding  engines  or  drawing  frames  of  any  descrip- 
tion.   They  form  largft  coils,  9  inches  in  diameter  and  22  inches  long,  when  on  the 


700 


SPINNING. 


machine.  ^  There  are  two  spindles,  a,  (see  jig.  1382.)  on  each  machine,  for  the  purpose  of 
doffiog;  withont  stopping  the  drawing  frame  and  caraing  engines.    When  one  eoil  it 


Vattfids  of  J  849 


filled,  the  finger,  h,  is  just  brought  over  to  the  other  spindle,  so  that  the  full  coil  is 
stopped  and  the  new  one  begins  to  be  formed  without  the  slightest  interruption  of  the 
machine. 

Mr.  B.  forms  coils  in  various  ways,  also  in  cans ;  but  this  description  is  suflRcient  to 
show  the  application  of  this  mode  of  winding  up  bands  or  rovings.  Several  of  the  above- 
described  machines  are  adopted  with  equal  success  to  wool  and  flax.  In  his  patents  of 
1835,  1837,  and  1838,  he  shows  several  modes  of  applying  his  system  to  cotton  and  other 
machinery.  He  winds  directly  from  the  carding  engines  the  slivers  separately  upon  long 
bobbins,  and  he  gives  them  twist  in  two  directions,  for  the  purpose  of  uniting  the  fibres 
to  some  extent,  so  that  they  not  only  come  off  the  bobbins  without  sticking  to  one 
another,  but  also  that  they  may  draw  smoother.  He  also  showed  a  machine,  by  which 
several  rovings,  say  4  or  more,  are  put  upon  the  same  bobbin  with  conical  ends; 
these  bobbins  are  placed  behind  the  mules  or  throstles,  and  are  unwound  by  a  belt  or 
strap  running  parallel  with  the  fluted  rollers  of  the  spinning  machine  as  seen  in^^.  1338. 
The  belt  or  band  a,  is  worked  in  a  similar  way  to  that  described  in  his  former  patent, 
and  the  bobbins,  b,  rest  upon  and  revolve  upon  their  surface,  exactly  according  to  the 
speed  of  the  belt.  It  is  auite  evident  that  the  whole  set  of  rovings  must  be  unwound 
exactly  at  the  same  speed,  and  that  no  stretching  can  take  place.  He  can  put  real  and 
reversed  twist  in  these  rovings  as  well  as  fabe  twist  only.  The  most  important  feature 
in  the  roving  machine  is  a  metal  plate,  in  which  a  slot  is  formed  through  which  the 
rovings  pass;  this  slot  is  seen  in  jigi,  1334,  1835,  and  1336.  The  cotton  when  coming 
from  the  drawing  rollers  is  passed  through  the  twisters,  c,  and  through  the  slot  in  the 
plate,  D.  Thus  he  is  enabled  to  put  any  convenient  number  of  neatly  formed  and  per- 
fectly separate  coils  upon  the  wooden  barrel  or  bobbin.  The  bobbin  formed  upon  these 
machines  is  represented  vajig.  1337.,  and  the  conical  ends  are  formed  by  a  mechanism,  by 
which  the  twisters,  c,  are  caused  to  approach  a  little  more  to  one  another,  after  each 
layer  of  rovings  has  been  coiled  round  the  barrel :  the  section  of  the  bobbin  is  therefore 
like  that  shown  in  fig.  1337.  He  makes  use  of  exactly  the  same  arrangements,  viz.,  a 
finger  trayelling  along  a  slot  in  a  plate,  for  the  purpose  of  forming  the  coils,  which  has 
Deen  already  described. 

Bovings  wound  upon  bobbins  by  means  of  tubes  revolving  in  one  direction  are  cer* 


SPINNING. 


701 


1JjS4 


■  ■■Till  II H  Ihl  III!  iiTtra^ 


AAAiS 


1336 


1336 


W^ty^yg: 


PatMi  of  1835. 


fi1=F 


1 — V 


^^      ^         1         /-IT^ 


1837 


teinly  not  so  fit  for  spinning  as  rovings  into  which  a  smaU  degree  of  twist  is  put.    The 
tube  by  which  a  twist  is  put  in  on  one  side  and  taken  out  at  the  othercuSs  ^  ruffleS 

^th  Sr*^  '*^'''.'' '?  ^^^^^  °"^  ^«  "^  P^««^^  between   he  rolSs,  wWIe  r^« 
with  a  httle  permanent  twist  in  them  are  held  together  in  the  nrnPP«  nf^ri^lv^     ^ 

thus  produce  smooth  yam.    To  remedy  the  evU  above  described  when  ^inLI^J^J^'  ^ 

There  is  a  little  defect  in  the  working  of  the  rovings  with  rever«.i»d  twict  «Ko-  ♦^ 

SS'er  ''^s^d!? eir  ^' ''  ^";  ^?  *' V^  "^^^  "^«  win^g  mach^et  nTkep'^'i^^^ 
^\\^?^^.w     y    proceeds  from  the  change  in  the  twist  of  the  roving  seen  at  A 
H^  1338 ;  in  this  place  the  twist  is  not  like  that  at  B,  and  it  would,  in  some  S  Sf  the 

1338 


"  ' — ^-^  ^<^J^^  ^ 


B 


S 


yam,  be  detected  under  circumstances  lust  descrihp/?      Tn  *.«««»  «a j     . , 

are  used,  the  twisters  are  so  arranged  i^to  pnt'hftWi.t  in^^^  double  rovings 

Jig.  1339 ;  in  this  case  the  reversing  place  of  one  rovW  mi?t!*'tt  '*"♦!? f '/'.  ^^""^^  ^^ 
Other,  and  the  fault  is  completely  rectified.  ^        ^^  ^®  ^""^^  P^*^^  *»^  ^« 

1339 


SPIRITS. 


SPIRITS. 


703 


702 

W  with  the  xnule  arc  contained  in  the  --^^^^^^^^^^^^         LtrfVw^TmVe:'  ^f. 
i;Slcs,as  seen  in  fig-  l^^O  «  and  &,  the  ^elf-actors    to  e  ^^  ^^.^^  ^^^  ^^^  ^^ 

1340  bands  and  shaftswith  the  self-actor, 

or  rather  partly  self-actor.    A  girl 
of  fifteen  or  sixteen  years  old  stands 
at  X  between  a  and  &,  and  never 
leaves  her  place  except,  perhaps,  for 
aiding  in  doffing  or  in  banding  the 
spindles.    The  gearing  of  the  room 
acts  by  means  of  straps  upon  the 
machines  a  and  6,  and  from  these 
machines  all   the  movements   axe 
given  to  the  six  mules,  namely,  the 
motion  of  the  rollers,  the  spmdles, 
the  drawing  out  of  the  carnage,  the 
after  draft,  &c.   When  the  carnages 
are  to  be  put  up,  the  girl  takes 
hold  of  two  levers  of  the  machine  a, 
and  by  moving  them  in  certain  pr(^ 
portions,  mcts  upon  two  cones  and 
pulleys,  and  thus  causes,  m  the  most 
easy  and  certain  manner,  the  car- 
riages to  run  in  and  the  yarn  to  be 
wound  on  the  spindles     The  first 
machine  Mr.  B.  made  for  this  pur 
pose  was  completely  self-acting,  but 
he  found  very  soon  that  the  me- 
chanism was  more  complicated  and 
apt  to  go  out  of  order  than  that  of 
.  the  above-described  machine  ;  and 

as  it  is  necessary  to  have  a  girl  of  a  certain  ay  to  watc^^  over  the  Piece- [^^^^^^^ 
dumber  of  mules,  he  prefenred  the  simplified  maclnne ,  P  ^c^ JgJ  ^^^  ^,,  overlooked 
machines,  from  whence  the  yl^^^J  «^^°f  ^^^fed    ^^  this  impediment  to  the 

as  the  creeis  behind  tne  mules  are  n^^^^^J^^^^'^i^ege  machines  for  the  purpose  of 
^l-.f.'l:fim^elUnZ^eI^^^  self-actors;  they  are  equally 

^i^^T^z^^"^^  ^^.S  wih^i;  :;X  tmtT^t  asi; 

Tcry  simple  bastard  fr^'^^"  H  fhVthev  can  JL  handled  about  without  any  danger  of 
in  jig.l34l,and  wound  so  hard  hat  they  can  ^^  hanai  ^^^^^  one  third 

•^        1341  spoiling  them;  \^f ^  l^^^J^^f  self-actors.    The  machme  la 
"^o'^e  yarn  than  the  best  cops  oi   s  circumstances   in  the 

/r: U-r^^--,    extremely  simple;   but   ^^^^^^S^^^f*  ^^°J^^   "e  has  not  been  able 

QX -'b:^^-^    constniction  of  the  wmders  and  P**^^/'  f^^^^'^A^^     no.  20's. 

"^^^ U)  spin   fvantageously  upon  large  mac^^^^^^^ 

He  has   spun  on  it  No.  56  and  most  ^^autiful  y^n     The  quani  y     ^^  ^^^^^^  ^^ 

produces  is  nearly  one  third  more  ^^^^^^^^^^^^^/^^^^^^^^  the?e   is  a  copping 

Spindles,  and  the  yarn  and  cops  are  much  superior.  J^  .    continuous,  as  weU 

motion   connected  with  the  machine:  ^^  ^^^^^^i^f'^S^^^  Jhe 

'"spirit  of  ammonia,  is,  property  speaking,  alcohol  combined  .ith  ammon.a  gaa; 

nr  checks  the  fermenting  process,  though  a  gi^^at  aeai  oi  i  ^^^^^^^. 

"uLtnged.  Mr.  Sheruian  '- -S^,'"  "^.X  '^^'  ^1^  's^^rU^i""  i^forn,ed.  For 
Z  tj;£TlT:Z  ITiXth-i  ; ^L'U  'connected  U.  a  50-^^^^^, 
lorked  by  machinery,  thus  continually  ^«";°""J.'^  '"Sol  readily  distils  at  » 
^^ZtS\^^^^.  ^Sr^^Vilur  dt^^f  tat  is  not  injurious  to  th. 


W( 


B 


Patents  of  1888  and  1842. 

fermentation,  provided  that  it  be  communicated  by  the  air  of  a  stove-room,  and  not  by 
water  or  steam  pipes  traversing  the  liquid,  which  would  inevitably  scald  or  seeth  the 
particles  in  succession,  and  thereby  extinguish  the  fermenting  principle. 

By  the  above  ingenious  plan,  Mr.  Sheridan  tells  me  he  has  obtained  28  gallons  of 
proof  spirit  from  a  quarter  of  grain,  instead  of  the  average  product,  21,  being  an  increase 
of  25  per  cent.  The  experiment  was  tried  upon  a  considerable  scale  at  Messrs.  Currie'a 
great  distillery  near  London ;  but  could  not  be  established  as  a  mode  of  manufacture,  on 
account  of  the  excise  laws,  which  prohibit  the  distillers  from  carrying  on  the  two  pro- 
cesses of  fermentation  and  distillation  at  the  same  time. 

Consumption  of  Spirits— According  to  a  return  recently  made,  the  total  number  of 
gallons  of  proof  spirits  distilled  in  the  United  Kingdom  during  the  year  ending  January 
5,  1860,  was  24,775,128,  distributed  among  the  three  kingdoms  thus :  — England, 
6,573,411  gallons,  of  which  5,865,600  were  from  raalt  with  unmalted  grain  17  837  from 
sugar  or  molasses  with  unmalted  grain,  13,941  from  sugar,  and  176,553  from  molasses; 
Scotland  10,846,634  gallons,  of  which  6,058,086  were  from  malt  only,  and  4,788,554 
from  malt  with  unmalted  grain;  Ireland,  8,355,883  gallons,  of  whicli  85,756  were  from 
malt  only,  8,047,077  from  malt  with  unmalted  grain,  and  222,250  from  sugar  or  molasses 
with  unmalted  grain.  The  number  of  gallons  of  proof  spirits  on  which  duty  was  paid 
for  home  consumption  in  the  United  Kingdom  was  22,962,012.  the  total  amount  of  duty 
,  ^o^;2fo'oPi:  ^*'  distributed  as  follows  :  — England,  676,036  gaUons  from  malt 
only,  8,166,226  from  malt  mixed  with  unmalted  grain,  14,740  from  sugar,  and  177,052 
from  molasses;  total.  9,053,676  gallons,  on  which  3,546,023/.  2s.  duty  was  paid,  at  the 
rate  of  Is.  lOd  per  gallon ;  Scotland,  4,950,736  gallons  from  malt  only;  1,984,115 
from  malt  mixed  with  unmalted  grain,  and  152  from  sugar;  total.  6,936,003  gallons, 
on  which  the  duty,  at  3s.  Sd.  per  gallon,  amounted  to  1,271,417/.  4«.  4d ;  Ireland, 
452,468  gallons  from  malt  only,  6,404,770  from  malt  mixed  with  unmalted  grain, 
112,308  from  sugar  or  molasses  with  unmalted  grain,  and  3,787  from  sugar;  total, 
6.973,833  gallons,  yieldmg,  at  the  rate  of  2a.  8d.  per  gallon,  an  amount  of  duty  equal  to 
929,777/.  14«.  Sd. 


Y04 


SPIRITS. 


SPIRITS. 


705 


SPIRITS.    Correspondence  between  Specific  Gravity  and  per  Centa.  over  Proof  at  «f  P 


Specific      ] 
OraTtij.     C 

Per  Cent. 

Specific 

Per  Cent. 

Specific 

»ver  Proof. 

Gravity.     0 

ver  Proof. 

Gravity. 

0-8890 

67-0 

•8455 

517 

•8748 

•8160 

668 

•8459 

515 

•8751 

•8163 

66^fi 

•8463 

51-3 

•8755 

•8167 

66' 5 

•8465 

511 

•8758 

•8170 

66  3 

•8469 

509 

•6762 

•8174 

66' 1 

•8472 

50-7 

•8765 

•8178 

65-6 

■8476 

50-5 

•8769 

•8181 

658 

•8480 

50-3 

■8773 

•8185 

65-6 

•8483 

501 

•8776 

•8188 

655 

•8486 

49-9 

•8779 

•8I0S 

65-3 

•8490 

49^7 

•8783 

•8196 

65  1 

•8493 

495 

-8786 

•8199 

650 

•8496 

49*3 

•8790 

•8203 

648 

•8499 

49-1 

•8793 

•8306 

64-7 

•8503 

489 

•8797 

•8310 

64-5 

•8506 

487 

•8800 

-BM 

643 

•8510 

48-5 

•8804 

8318 

64  1 

•8513 

48-3 

•8807 

•8221 

64  0 

•8516 

480 

'8811 

•8334 

638 

•8520 

47-8 

•8814 

•6337 

636 

•8523 

476 

•8818 

•8331 

634 

•8527 

474 

-8822 

•8334 

633 

•8530 

473 

•8825 

8338 

63.1 

•8533 

470 

•8829 

•8S4S 

63-9 

•8537 

468 

•8833 

•8345 

63-7 

•8540 

466 

•8836 

•8249 

63-5 

•8543 

464 

•8840 

•8252 

633 

•8547 

46-3 

•8843 

•8256 

63-3 

•8550 

460 

•8847 

•8259 

630 

•8553 

45-8 

•8850 

•8363 

618 

•8556 

456 

-8854 

•8260 

616 

•8560 

45'4 

•8858 

•8370 

61*4 

•8563 

453 

•8861 

•8373 

613 

•8566 

450 

•8865 

•8277 

61-1 

•8570 

44-8 

•8869 

•8280 

609 

•8573 

446 

•8873 

•8284 

60-7 

•8577 

444 

•8876 

•8387 

60-5 

•8581 

44-3 

•8879 

•8391 

604 

•8583 

439 

•8883 

'8394 

603 

•8587 

43-7 

•8886 

•8398 

600 

•8590 

435 

•8890 

•8301 

59-8 

•8594 

433 

'8894 

•8305 

596 

•8597 

431 

•8897 

•8308 

595 

•8601 

438 

•8901 

■8313 

69-3 

•8604 

43*6 

•8904 

•8315 

591 

•8608 

434 

•8908 

•8319 

58-9 

•8611 

43-3 

•8913 

•8333 

58-7 

•8615 

420 

•8915 

•8336 

586 

•8618 

417 

•8919 

•8339 

58-4 

•8023 

41-5 

•8923 

•8333 

583 

•8625 

41-3 

•8926 

•8336 

580 

•8629 

41-1 

•8930 

•8340 

57-8 

•8633 

40-9 

•8933 

•8344 

577 

'8636 

400 

•8937 

•8347 

67-5 

•8639 

404 

•8940 

•8351 

57-3 

'8643 

403 

•8944 

•8S54 

671 

•8646 

400 

•8948 

•8158 

56'9 

'8650 

398 

•8951 

•8363 

568 

•8653 

39-5 

•8955 

•8365 

566 

•8657 

393 

•8959 

•8369 

564 

•8660 

391 

•8963 

•8373 

563 

•8664 

38  9 

•8966 

•8376 

56-0 

•8667 

38-7 

•6970 

1                  *• —     ^ 

•8379 

559 

•8671 

38-4 

•8974 

•8383 

55-7 

•8674 

38-3 

•8977 

•8380 

555 

•8678 

380 

•8981 

'8390 

55-3 

•8681 

37  8 

•8985 

'8393 

551 

•8685 

376 

•8989 

•8396 

55-0 

'8688 

373 

•8993 

•8400 

548 

•8699 

371 

•8996 

•8403 

54-6 

•8695 

369 

•9000 

•8407 

54-4 

•8699 

367 

•9004 

•8410 

543 

'8703 

364 

•9008 

•8413 

541 

•8706 

362 

•9011 

•8417 

53-9 

•8709 

359 

•9015 

•8420 

53-7 

•8713 

35-7 

•9019 

•8434 

535 

•8716 

355 

•9023 

•8437 

53-3 

•8720 

352 

•9026 

•8431 

53-1 

•8733 

350 

•9030 

'8434 

52-9 

•8727 

847 

•9034 

8438 

537 

-8730 

34-5 

•9038 

'8441 

535 

-8734 

343 

•9041 

'£445 

533 

-8737 

34  1 

•9045 

■8448 

531 

•8741 

33-8 

•9049 

•845t 

ftl9 

-8744 

336 

•MSt 

Per  Cent 
Over  Proof. 


334 

333 

339 

337 

334 

33-3 

330 

317 

315 

31-3 

310 

308 

305 

30-3 

300 

39-8 

295 

39  3 

290 

288 

385 

283 

28-0 

37-8 

275 

37-3 

370 

368 

365 

363 

360 

358 

355 

35-3 

350 

348 

345 

34-3 

34*0 

33-8 

23-5 

232 

23-0 

22-7 

225 

232 

219 

217 

21*4 

21-3 

20-9 

306 

90*4 

201 

19-9 

196 

19-3 

191 

188 

186 

18  3 

180 

17-7 

175 

17  9 

16^9 

16-6 

16-4 

16-1 

15^9 

15-6 

15-3 

150 

148 

145 

143 

139 

13-6 

13*4 

131 

13-8 

13-5 

13-3 

ISO 

11-7 


Specific 
Gravity. 


Per  Cent 
Over  Proof. 


■9056 
■9060 
■9064 
•9067 
•9071 
•9075 
•9079 
•9083 
•9085 
•9089 
•9093 
•9097 
•9000 
•9104 
•9107 
•9111 
•9115 
•9118 
•9133 
•9136 
•9130 
•9134 
•9137 
•9141 
•9145 
•9148 
•9153 
•9156 
9159 
•9163 
♦9167 
•9170 
•9174 
•9178 
•9183 
•9185 
•9189 
•9193 
•9196 
•9200 

Under 
•9204 
•9207 
•9210 
•9314 
•9218 
9223 
•9336 
9939 
•9333 
9237 
•9341 
•9344 
•9348 
•9259 
•9855 
•9959 
■9963 
•9267 
•9370 
•9274 
•9378 
•9383 
•9386 
•9991 
•9295 
•9299 
'9309 
•9306 
•9310 
•9314 
•9318 
•9329 
•9336 
•9339 
•9333 
•9337 
•9341 
•9345 
•9349 
•9353 
•9357 
•9360 
•9364 
•9368 


114 

HI 

108 

106 

10-3 

100 

97 

9-4 

99 

89 

86 

8S 

80 

77 

7^4 

71 

66 

6-5 

6-9 

5-9        I 

56 

5-3 

50 

48 

45 

49 

i'9 

S-6 

33 

30 

97 

3-4 

31 

1-9 

16 

1-3 

10 

0-7 

03 

Proof 
Proof. 
0^3 
0-6 
09 
13 
1-6 
19 
99 
95 
9-8 
31 
34 
17 
40 
4-4 
47 
SO 
5S 
67 
60 
64 
6-7 
70 
7-S 
7-7 
80 
8-3 
86 
90 
93 
97 

loo 

lOS 
lO^T 
110 

ir4 
irt 

I9^1 
134 
13-S 
131 
IS'6 
13-0 
^•t 
14-t 


\ 


Table — continued. 

I     Specific 

Per  Cent. 

Specific 

Per  Cent. 

Specific 

Per  Cent. 

Specific 

PerCoKt 

1     Gravity. 

Under  Prf. 

Gravity. 

Under  Prf. 

Gravity. 

Under  Prf. 

Gravity. 

Under  Prf. 

1       •9373 

14-9 

9530 

310 

•9685 

522 

•9846 

79-3 

1        -9376 
1        •9380 

15  3 

•9534 

31-4 

•9689 

529 

•9850 

798 

15-7 

•9539 

311 

•9693 

533 

•9854 

80-4 

1        •9384 

160 

9542 

32-8 

•9697 

542 

•9858 

81  1 

•9388 

16-4 

-9546 

32-8 

•9701 

54^8 

-9862 

817 

•9392 

167 

-9550 

332 

•9705 

555 

■9866 

823 

•9396 

171 

•9553 

33  7 

•9709 

56  2 

•9&70 

829 

•9399 

175 

-9557 

34-2 

•9713 

569 

•9874 

83-5 

•0403 

178 

•9561 

34  6 

•9718 

576 

•9878 

840 

•9407 

182 

•9565 

35  1 

•9722 

58-3 

•9882 

84-6 

•9411 

185 

•9569 

356 

•9726 

590 

•9886 

858 

•9415 

18-9 

•9573 

361 

•9730 

59-7 

•9890 

85*8 

•9419 

19  3 

•9577 

866 

•9734 

60-4 

•9894 

863 

■9422 

197 

•9580 

371 

•9738 

611 

-9698 

869 

-9425 

20  0 

•9584 

376 

•9742 

61-8 

•9902 

87  4 

•9430 

304 

•9588 

381 

•9746 

62-5 

•9906 

880 

•9434 

208 

•9592 

386 

•9750 

632 

•9910 

885 

-9437 

21  2 

•9596 

39  1 

•9754 

639 

•9914 

891 

I        -9441 

216 

•9599 

396 

•9758 

64  6 

•9918 

896 

•9445 

21  9 

•9eo3 

401 

•9762 

653 

•9922 

90.3 

•9148 

223 

•9607 

406 

•9766 

660 

9926 

90-7 

-9452 

22  7 

•9611 

411 

•9770 

667 

•9930 

91-2 

■9456 

23-1 

•9615 

417 

•9774 

674 

•9934 

917     • 

•9460 

235 

•9619 

422 

•9778 

68-0 

■9938 

923 

9464 

239 

•9623 

42-8 

•9782 

68^7 

•9942 

92-8 

,        -9468 

243 

•96«7 

433 

•9786 

694 

•9946 

933 

•9 172 

247 

•9631 

43  9 

•9790 

701 

•9950 

938 

■»476 

25  1 

•9635 

444 

■9794 

708 

•9954 

943 

•9480 

25  5 

•9638 

450 

•9798 

714 

•9958 

94  9 

•9484 

25-9 

•9642 

455 

9802 

72-1 

♦9963 

95-4 

•9488 

26-3 

•9646 

4«1 

•9806 

728 

•9966 

959 

•9492 

267 

•9650 

46-7 

'9810 

735 

•9970 

96.4 

■9496 

271 

•9654 

473 

■9814 

741 

•9974 

968 

•9i99 
•95(13 

875 

-9657 

479 

■9816 

74^8 

•9978 

97  1 

28-0 

•9661 

485 

•9822 

754 

•9983 

97-7 

•9507 

284 

•9665 

491 

•9826 

7«1 

•9986 

983 

•9511 
•9515 

28^8 

•9669 

497 

•9830 

76-7 

•9990 

98-7 

29-2 

•9674 

50-3 

•9834 

773 

•9993 

99-1 

•9519 
•9522 
•9526 

29-7 
301 
30iJ 

•9677 
•9661 

510 
516 

•9838 
•9842 

78-0 
786 

-9997 
10000 

91.6 
lOOO 

The  total  number  of  gallons  of  proof  spirits  imported  into  England  in  the  year  ending 
January  6,  1850,  from  Scotland,  amounted  to  2,651,529  gallons,  of  which  678,342  were 
distilled  from  malt  only,  and  1,978,187  from  a  mixture  of  malt  with  unmalted  grain ;  and 
the  total  amount  of  duty  paid  thereon,  at  the  rate  of  Is.  lOd.  per  gallon,  was  1,038,'5164 
10«.  6rf.,  being  513,3.30/.  8«.  on  removal  from  bond,  and  525,185/.  2«.  6«i  after  arrival  at 
the  place  of  destination.  The  number  of  gallons  imported  from  Ireland  was  890  021  of 
which  1,694  were  from  malt  only,  884,772  from  malt  with  unmalted  grain,  3,285  firom 
sugar  or  molasses  with  grain,  and  270  from  sugar ;  and  the  total  amount  of  duty  paid 
was  348,591/.  11«.  2d.,  being  118,912/.  Is.  6d.  on  removal  from  bond,  and  229,679/.  3^8dL 
after  arrival  at  the  place  of  destination.  The  number  of  gallons  imported  from  Scotland 
mto  Ireland  was  766,405,  of  which  396,064  were  from  malt  only,  370,205  from  malt 
mixed  with  gram,  and  136  from  sugar,  the  amount  of  duty  paid,  at  the  rate  of  2*.  8<i. 
bemg  102,187/.  6«.  8rf.,  levied  after  arrival  at  the  place  of  destination.  The  quantity 
imported  trom  Ireland  into  Scotland  was  12.580  gallons,  of  which  12,428  were  from  malt 

T^^^J^^]^^^}^^  ^^^  ^^^'  ^^  ^^  ^^^y  P*^<i  thereon,  at  the  rate  of  Ss.  8c/.,  amounted 
Co  2,806/.  6<.  8a. 

SPIRIT  OF  WINE;  Alcohol. 

SPONGE  (Eponge,  Fr. ;  Schwamm,  Germ.),  is  a  cellular  fibrous  tissue  produced  by 
small  animals,  ahnost  imperceptible,  called  polypi  by  naturalists,  which  live  in  the  sea. 
This  tissue  IS  said  to  be  covered  in  its  recent  state  with  a  kind  of  semi-fluid  thin  coat  oi 
animal  jelly,  susceptible  of  a  slight  contraction  or  trembling  on  being  touched ;  which 
is  the  only  symptom  of  vitality  displayed  by  the  sponge.  After  death,  this  jelly  disap- 
pears, and  leaves  merely  the  sponge ;  formed  by  the  combination  of  a  multitude  of  smaB 
capillary  tubes,  capable  of  receiving  water  in  their  interior,  and  of  becoming  thereby  dk. 
tended.  Sponges  occur  attached  to  stones  at  the  bottom  of  the  sea ;  and  abound  par- 
ticularly upon  the  shores  of  the  islands  in  the  Grecian  Archipelago.  Although  analo- 
gous in  their  origin  to  coral,  sponges  are  quite  different  in  their  nature ;  the  former 
being  composed  almost  entirely  of  carbonate  of  lime;  while  the  latter  are  formed  of  the 
same  elements  as  animal  matters,  and  afford,  on  distillation,  a  considerable  quantity  U 
ammonia. 


706 


STAINED  GLASS. 


Dilute  sulphuric  acid  has  been  recommended  for  bleaching  sponges,  after  the  calcare* 
ous  impurities  have  been  removed  by  muriatic  acid.    Chlorine  water  answers  better. 

SPOON  MANUFACTURE.     See  Stamping  of  Metals. 

STAINED  GLASS.  When  certain  metallic  oxydes  or  chlorides,  ground  np  with 
proper  fluxes,  are  painted  upon  glass,  their  colors  fuse  into  its  surface  at  a  moderate 
heat,  and  make  durable  pictures,  which  are  frequently  employed  in  ornamenting  the 
windows  of  churches  as  well  as  of  other  public  and  private  buildings.  The  colors  of 
stained  glass  are  all  transparent,  and  are  therefore  to  be  viewed  only  by  transmitted 
light.  Many  metallic  pigments,  which  afford  a  fine  effect  when  applied  cold  on  canvast 
or  paper,  are  so  changed  by  vitreous  fusion  as  to  be  quite  inapplicable  to  painting  in 
stained  glass. 

The  glass  proper  for  receiving  these  vitrifying  pigments,  should  be  colorless,  uniform, 
and  difficult  of  fusion ;  for  which  reason  crown  glass,  made  with  little  alkali,  or  with 
kelp,  is  preferred.  When  the  design  is  too  large  to  be  contained  on  a  single  pane,  seve- 
ral are  fitted  together,  and  fixed  in  a  bed  of  soft  cement  while  painting,  and  then  taken 
asunder  to  be  separately  subjected  to  the  fire.  In  arranging  the  glass  pieces,  care  must 
be  taken  to  distribute  the  joinings  so  that  the  lead  frame-work  may  interfere  as  little  ai 
possible  with  the  effect. 

A  design  must  be  drawn  upon  paper,  and  placed  beneath  the  plate  of  glass ;  though 
Ihe  artist  cannot  regulate  his  lints  directly  by  his  palette,  but  by  specimens  of  the  colors 
producible  from  his  palette  pigments  after  they  are  fired.  The  upper  side  of  the  glass  be- 
ing sponged  over  with  gum-water,  affords,  when  dry,  a  surface  proper  for  receiving  the 
colors,  without  the  risk  of  their  running  irregularly,  as  they  would  be  apt  to  do,  on  the 
slippery  glass.  The  artist  first  draws  on  the  plate,  with  a  fine  pencil,  all  the  traces  which 
mark  the  great  outlines  and  shades  of  the  figures.  This  is  usually  done  in  black,  or,  at 
least,  some  strong  color,  such  as  brown,  blue,  green,  or  red.  In  laying  on  these,  the 
painter  is  guided  by  the  same  principles  as  the  engraver,  when  he  produces  the  effect  of 
light  and  shade  by  dots,  lines,  or  hatches ;  and  he  employs  that  color  to  produce  the 
shades,  which  will  harmonize  best  with  the  color  which  is  to  be  afterwards  applied  ;  but 
for  the  deeper  shades,  black  is  in  general  used.  When  this  is  finished,  the  whole  pic- 
ture will  be  represented  in  lines  or  hatches  similar  to  an  engraving  finished  up  to  the 
highest  effect  possible  ;  and  afterwards,  when  it  is  dry,  the  vitrifying  colors  are  laid  on 
by  means  of  larger  hair  pencils ;  their  selection  being  regulated  by  the  burnt  specimen 
tints.  When  he  finds  it  necessary  to  lay  two  colors  adjoining,  which  are  apt  to  run 
together  in  the  kiln,  he  must  apply  one  of  them  to  the  back  of  the  glass.  But  the  few 
principal  colors  to  be  presently  mentioned,  are  all  fast  colors,  which  do  not  run,  except 
the  yellow,  which  must  therefore  be  laid  on  the  opposite  side.  After  coloring,  the  artist 
proceeds  to  bring  out  the  lighter  effects  by  taking  off  the  color  in  the  proper  place,  with 
a  goose  quill  cut  like  a  pen  without  a  slit.  By  working  this  upon  the  glass,  he  removes 
the  color  from  the  parts  where  the  lights  should  be  the  strongest ;  such  as  the  hair,  eyes, 
the  reflection  of  bright  surfaces  and  light  parts  of  draperies.  The  blank  pen  maybe 
employed  either  to  make  the  lights  by  lines,  or  hatches  and  dots,  as  is  most  suitable  to  thi 

subject.  J    r     u  •      e    A 

By  the  metallic  preparations  now  laid  upon  it,  the  glass  is  made  ready  for  l)eing  lired, 
in  order  to  fix  and  bring  out  the  proper  colors.  The  furnace  or  kiln  best  adapted  for  this 
purpose,  is  similar  to  that  used  by  enamellers.  See  Enamel,  and  the  Glaze-kiln,  under 
PoTTiiRY.  It  consists  of  a  muf&e  or  arch  of  fire-clay,  or  pottery,  so  set  over  a  fireplace, 
and  so  surrounded  by  flues,  as  to  receive  a  very  considerable  heat  within,  in  the  most 
equable  and  regular  manner ;  otherwise  some  parts  of  the  glass  will  be  melted ;  while, 
on  others,  the  superficiar  film  of  colors  will  remain  unvitrified.  The  mouth  of  the  muffle, 
and  the  entry  for  introducing  fuel  to  the  fire,  should  be  on  opposite  sides,  to  prevent  as 
much  as  possible  the  admission  of  dust  into  the  muflle,  whose  mouth  should  be  closed 
with  double  folding-doors  of  iron,  furnished  with  small  peep-holes,  to  allow  the  artist  to 
watch  the  progress  of  the  staining,  and  to  withdraw  small  trial  slips  of  glass,  painted  with 
the  principal  tints  used  in  the  picture. 

The  muflie  must  be  made  of  very  refractory  fire-clay,  flat  at  its  bottom,  and  only  5  or 
6  inches  high,  with  such  an  arched  top  as  may  make  the  roof  strong,  and  so  close  on  all 
sides  as  to  exclude  entirely  the  smoke  and  flame.  On  the  bottom  of  the  muflie  a  smooth 
bed  of  sifted  lime,  freed  from  water,  about  half  an  inch  thick,  must  be  prepared  for 
receiving  the  pane  of  glass.  Sometimes  several  plates  of  glass  are  laid  over  each  other 
with  a  layer  of  dry  pulverulent  lime  between  each.  The  fire  is  now  lighted,  and  most 
gradually  raised,  lest  the  glass  should  be  broken ;  and  after  it  has  attained  to  its  full  heat, 
it  must  be  kept  up  for  3  or  4  hours,  more  or  less,  according  to  the  indications  of  the 
trial  slips ;  the  yellow  color  being  principally  watched,  as  it  is  found  to  be  the  best  crite- 
rion of  the  state  of  the  others.  When  the  colors  are  properly  burnt  in,  the  fire  is  suffered 
to  die  away,  so  as  to  anneal  the  glass. 


STAINED  GLASS. 


STAINED-GLASS  PIOMENTI. 


707 


Flesh  color. — Take  an  ounce  of  red  lead,  2  ounces  of  red  enamel,  (Venetian  glass  ena- 
mel, from  alum  and  copperas  calcined  together,)  grind  them  to  fine  powder,  and  work  this 
Dp  with  spirits  (alcohol)  upon  a  hard  stone.  When  slightly  baked,  this  produces  a  fine 
flesh  color. 

Black  color. — ^Take  14ji  ounces  of  smithy  scales  of  iron,  mix  them  with  two  ounces  of 
white  glass,  (crystal,)  an  ounce  of  antimony,  and  half  an  ounce  of  manganese;  pound  and 
grind  these  ingredients  together  with  strong  vinegar.  A  brilliant  black  may  also  be  ob- 
tained by  a  mixture  of  cobalt  blue  with  the  oxydes  of  manganese  and  iron.  Another  black 
is  made  from  three  parts  of  crystal  glass,  two  parts  of  oxyde  of  copper,  and  one  of  (glass 
oC)  antimony  worked  up  together,  as  above. 

Brown  color.— An  ounce  of  white  glass  or  enamel,  half  an  ounce  of  good  manganese; 
ground  together. 

Red,  rose,  and  brown  colors,  are  made  from  peroxyde  of  iron,  prepared  by  nitric  acid. 
The  flux  consists  of  borax,  sand,  and  minium  in  small  quantity. 

Bed  color,  may  be  likewise  obtained  from  one  ounce  of  red  chalk  pounded,  mixed  with 
two  ounces  of  white  hard  enamel,  and  a  little  peroxyde  of  copper. 

*tf  red^  may  also  be  composed  of  rust  of  iron,  glass  of  antimony,  yellow  glass  of  lead, 
such  as  IS  used  by  potters,  (or  litharge,)  each  in  equal  quantity ;  to  which  a  little  sulpha- 
ret  of  silver  is  added.  This  composition,  well  ground,  produces  a  very  fine  red  color  on 
glass.  When  protoxyde  of  copper  is  used  to  stain  glass,  it  assumes  a  bright  red  or  green 
color,  according  as  the  glass  is  more  or  less  heated  in  the  furnace,  the  former  correspond- 
ing to  the  orange  protoxyde,  the  latter  having  the  copper  in  the  state  of  peroxyde. 

Bist'es  and  brown  reds,  may  be  obtained  by  mixtures  of  manganese,  orange  oxyde  of 
copper,  and  the  oxyde  of  iron  called  umber,  in  different  proportions.  They  rnust  be  pre- 
viously fused  with  vitreous  solvents. 

Green  color. — Two  ounces  of  brass  calcined  into  an  oxyde,  two  ounces  of  minium,  and 
eight  ounces  of  white  sand;  reduce  them  to  a  fine  powder,  which  is  to  be  enclosed  in  a 
well  luted  crucible,  and  heated  strongly  in  an  air-furnace  for  an  hour.  When  the  mix- 
ture is  cold,  grind  it  in  a  brass  mortar.  Green  may,  however,  be  advantageously  proda- 
ced  by  a  yellow  on  one  side,  and  a  blue  on  the  other.  Oxyde  of  chrome  has  been  also 
employed  to  stain  glass  green. 

Jifine  yellow  color. — Take  fine  silver  laminated  thin,  dissolve  in  nitric  acid,  dilate  with 
abundance  of  water,  and  precipitate  with  solution  of  sea  salt.  Mix  this  chloride  of  sil- 
ver, in  a  dry  powder,  with  three  times  its  weight  of  pipe-clay  well  burnt  and  pounded. 
The  back  of  the  glass  pane  is  to  be  painted  with  this  powder ;  for  when  painted  on  the 
face,  it  is  apt  to  run  into  the  other  colors. 

jSnother  yellow  can  be  made  by  mixing  sulphuret  of  silver  with  glass  of  antimony, 
and  yellow  ochre  previoustly  calcined  to  a  red-brown  tint.  Work  all  these  powders 
together,  and  paint  on  the  back  of  the  glass.  Or  silver  lamina  melted  with  sulphur,  and 
glass  of  antimony,  thrown  into  cold  water,  and  afterwards  ground  to  powder,  afford  a 
fellow. 

ji  pale  yellow  may  be  made  with  the  powder  resulting  fi-om  brass,  sulphur,  and  glass 
«** antimony,  calcined  together  in  a  crucible,  till  they  cease  to  smoke ;  and  then  mixed 
with  a  little  burnt  yellow  ochre. 

The  fine  yellow  of  M.  Merand  is  prepared  from  chloride  of  silver,  oxyde  of  zinc,  white- 
day,  and  rust  of  iron.     This  mixture,  simply  ground,  is  applied  on  the  glass. 

Orange  cotor.— Take  1  part  of  silver  powder,  as  precipitated  from  the  nitrate  of  that 
metal  by  plates  of  copper,  and  washed ;  mix  it  with  1  part  of  red  ochre  and  1  of  yellow, 
by  careful  trituration ;  grind  into  a  thin  pap  with  oil  of  turpentine  or  lavender,  and  apply 
this  with  a  brush,  dry,  and  burn  in. 

In  the  Philosophical  Magazine,  of  December,  1836,  the  anonymous  author  of  an  in- 
genious essay,  «  On  the  Art  of  Glass-painting,"  says,  that  if  a  large  proportion  of  ochre 
has  been  employed  with  the  silver,  the  stain  is  yellow ;  if  a  small  proportion,  it  is  orange- 
colored  ;  and  by  repeated  exposure  to  the  fire,  without  any  additional  coloring-matter, 
the  orange  may  be  converted  into  red ;  but  this  conversion  requires  a  nice  management 
of  the  heat.  Artists  often  make  use  of  panes  colored  throughout  their  substance  in  the 
glass-house  pots,  because  the  perfect  transparency  of  such  glass  gives  a  brilliancy  of 
effect,  which  enamel  painting,  always  more  or  less  opaque,  cannot  rival.  It  was  to  a 
glass  of  this  kind  that  the  old  glass-painters  owed  their  splendid  red.  This  is,  in  fact, 
the  only  point  in  which  the  modern  and  ancient  processes  differ ;  and  this  is  the  only 
part  of  the  art  which  was  ever  really  lost.  Instead  of  blowing  plates  of  solid  red,  the 
old  glass-makers  (like  those  of  Bohemia,  for  some  time  back)  used  to  J!a$h  a  thia 
layer  of  brilliant  red  over  a  substratum  of  colorless  glass ;  by  gathering  a  lump  of  the 
latter  upon  the  end  of  their  iron  rod  in  one  pot,  covering  it  with  a  layer  of  the  former 
in  another  pot,  then  blowing  out  the  two  together  into  a  globe  or  cylinder,  to  be  opened 


# 


708 


STAINED  GLASS. 


STAMPING  OF  METALS. 


709 


into  circular  tables,  or  into  rectangular  plates.    The  elegant  art  of  tinging  glass  red  by 
Jiotoxyde  of  copper',  and  flashing  it  on  common  crown  glass,  has  become  general  within 

^Tha' gold  melted  with  flint  glass  stains  it  purple,  wa.  originally  «J»scovered  and  pra^ 
tised,  as  a  profitable  secret,  by  Kunckel.  Gold  has  been  recently  used  at  BirminghMa 
for  giving  a  beautiful  rose-color  to  scent  bottles.  The  proportion  of  gold  should  be 
Tery  small,  and  the  heat  very  great,  to  produce  a  good  effect.  The  g^ss  must  contain 
either  the  oxyde  of  lead,  bismuth,  zinc,  or  antimony ;  for  crown  glass  will  take  no  color 
from  gold.  Glass  combined  with  this  ietal,  when  removed  from  the  crucible  is  general- 
yTf  I  pale  rose-color ;  nay,  sometimes  is  as  colorless  as  water,  and  does  not  assume  it* 
i^by  color  till  it  has  been  exposed  to  a  low  red  heat,  either  under  «  ^^f  ^  ^^  ^'J^ 
lamp.  This  operation  must  be  nicely  regulated ;  because  a  s  .ght  ^^^^^^^f^^^'^J'^l^J^ 
the  color,  leaving  the  glass  of  a  dingy  brown,  but  with  '^  ^"^  (^f  ^  ^^^I? X  n^^d ' 
like  that  of  gold  leaf.  It  is  metallic  gold  which  gives  the  color;  and,  indeed^  the  oxyde 
is  too  easily  reduced,  not  to  be  converted  into  the  metal  by  the  intense  heat  which  is  ne- 

'iTpon'thHifd-red  art  of  painting  in  enamel,  Mr.  A.  Essex  has  P-^li^^ed  an  ,„^^ 
teresting  paper  in  the  same  journal,  for  June,  1837,  in  which  he  says  hat  the  ancient 
^hy"r\>^^g  exposed  to  the  heat  of  a  glass-kiln,  preserves  its  color  unimpaireJ. 

while  the  modern  suffers  considerable  injury,  and  in  ^^^^^^  fi*^Tp'"ffp\hrior  ^ 
Hence  the  latter  cannot  be  painted  upon,  as  the  heat  requir^  to  fix  the  fresh  color  would 
destroy  the  beauty  of  the  original  basis.  To  obviate  this  difficulty,  the  artist  paints  uj^n 
a  piece  of  plain  glass  the  tints  and  shadows  necessary  for  blending  the  rich  ruby  g.ow 
whh  the  other  pirts  of  his  picture,  leaving  those  parts  untouched  where  he  wishes  he 
ruby  to  appear  in  undiminished  brilliancy,  and  fixes  the  ^J^hyglassjn  the  picture  b^^^^^^^ 
the  painted  piece,  so  that  in  such  parts  the  window  is  double  S^f^^.^'  ^f*  ^f "  '^^^ 
ploys,  as  did  the  late  Mr.  Muss,  chrome  oxyde  alone  for  greens ;  and  he  rejects  the  use 
ofiron  and  manganese  in  his  enamel  colors.  ,  .      .,  ,  „„m  wvo«/*w*   nr^ 

Colored  transparent  glass  is  applied  as  enamel  in  silver  and  ^^^^^^^^^e^n's 
viously  bright-cut  in  the  metal  with  the  graver  or  the  rose-engine  The  c^ts,  reflectin| 
the  rays  of  light  from  their  numerous  surfaces,  exhibit  through  the  glass,  "chly  stained 
with  gold,  silfer,  copper,  cobalt,  &c.,  a  gorgeous  play  of  P"sn^atic  co  ors  varied  with 
every  change  of  aspect.  When  the  enamel  is  to  be  painted  on  it  should  be  made  opal- 
e»cent  by  oxyde  of  arsenic,  in  order  to  produce  the  most  agreeable  eflect. 

The  artist  in  enamel  has  obtained  from  modern  chemistry,  preparations  of  the  metali 
platinum,  uranium,  and  chromium,  which  furnish  four  of  the  richest  and  most  useful 
colors  of  his  palette.  Oxyde  of  platinum  produces  a  substantive  "c^  h^^o^^Jormerl; 
unknown  in  enamel  painting;  a  beautiful  transparent  tmt,  which  no  intensity  or  repeti- 
tion of  fire  can  injure.  Colors  proper  for  enamel  pamting,  he  says,  are  not  to  be  pur- 
chased;  those  sold  for  the  purpose,  are  adapted  only  for  painting  upon  clnna  The  con- 
stituents of  the  green  enamel  used  by  his  brother,  Mr.  W.  Essex,  are,  silica,  borax,  oxyde 

°'»s:fx?s%t^m^^^^^^^^  is  a  cubic  space  of  about  ,2  inches  -d  contains 

fire-clay  muffle,  without  either  bottom  or  back,  which  is  surrounded  ^^th  coke,  except  i» 
front.     The   entire  draught  of  air  which   suppUes  the   furnace,   passes  through   the 

muffle;  the  plates  and  paintings  being  placed  ««,  V';%'^'t  "J^.f  AsTe  .r^^^^^^^^^ 
clay,  technically  termed  planche,  which  rests  on  the  bed  of  coke-fuel.  As  the  greatest 
heat  is  at  the  back  of  the  muffle,  the  picture  must  be  turned  round  ^hUc  in  the  fire, 
bv  means  of  a  pair  of  spring  tongs.  The  above  furnace  serves  for  objects  up  to  tve 
S^cSSSid^e^ter;  butV  larger  works  a  different  furnace  is  required,  for  the  descnp. 
tionofwhich  I  must  refer  to  the  original  paper.  ijr^^  «„  „!««» 

Relatively  to  the  receipts  for  enamel  colors,  and  for  staining  and  g'^ing  on  glas^ 
for  1th  twenty  guineas  were  voted  by  the  Society  for  the  Encouragement  of  Art^m 
the  session  of  1817,  to  Mr.  R.  Wynn,  Mr.  A.  Essex  says,  in  p.  446  of  his  essay 
J^heunrtunaJe  artist  who  shall  aUempt  to  make  colors  for  the  V-rvo.eo^v^rnU^^^^^^ 
enamel  from  these  receipts,  will  assuredly  find,  to  his  disappointment  that  they  ar^^ut^ 
terlv  useless."  In  page  449  he  institutes  a  comparison  between  Mr.  Wynn  s  complex 
frrrlgofbr  green"  as^ublished  in  the  Transactions  of  the  Society,  ^^/th  the  simple 
reS  of  hi!  brother,  as  given  above.  It  is  a  remarkable  circumstance,  that  not  one  of 
cur  enamel  artists,  dJirin|  a  period  of  twenty  years,  should  have  denounced  Uie  falUc, 
of  these  receipts,  and  the  folly  of  sanctioning  imposture  hy  a  public  reward.  Should 
Sir.  Essex's  animidversions  be  just,  the  well-intentioned  Soc  ety  H^^^^^  ^ddphi^^^^^^ 
the  negligence  of  its  committee,  come  to  merit  the  sobnquety  «  For  the  Discouragemem 

"^Ae^'blues  of  vitrified  colours  are  all  obtained  from  the  oxide  of  cobalt  Cobalt 
ore  (Bulph^et)  being  weU  roasted  at  a  dull  red  heat,  to  dissipate  all  the  sul- 
^m^dZ^uxc  iflllissolved.in   somewhat   dilute   nitric   acid,  and   after  the  addi 


tion  of  much  water  to  the  saturated  solution,  the  oxide  is  precipitated  by  carbonate  of 
soda,  then  washed  upon  a  filter,  and  dried.  The  powder  is  to  be  mixed  with  thrice  its 
weight  of  saltpetre ;  the  mixture  is  to  be  deflagrated  in  a  crucible,  by  applying  a  red 
hot  cinder  to  it,  then  exposed  to  the  heat  of  ignition,  washed,  and  dried.  Three  parts 
of  this  oxide  are  to  be  mixed  vrith  a  flux,  consisting  of  white  sand,  borax,  nitre,  and  a 
little  chalk,  subjected  to  fusion  for  an  hour,  and  then  ground  down  into  an  enamel 
powder  for  use.  Blues  of  any  shade  or  intensity  may  be  obtained  from  the  above,  by 
mixing  it  with  more  or  less  flux. 

The  beautiful  greenish  yellow,  of  which  color  so  many  ornamental  glass  vessels  have 
been  lately  imported  from  Germany,  is  made  in  Bohemia  by  the  following  process.  Ore 
of  uranium,  Uran-ochre,  or  Uran-glimmer,  in  fine  powder,  being  roasted,  and  dissolved 
in  nitric  acid ;  the  filtered  solution  is  to  be  freed  from  any  lead  present  in  it,  by  the 
cautious  addition  of  dilute  sulphuric  acid.  The  clear  green  solution  is  to  be  evapora- 
ted to  dryness,  and  the  mass  ignited  till  it  becomes  yellow.  One  part  of  this  oxide  is 
to  be  mixed  with  3  or  more  parts  of  a  flux,  consisting  of  4  parts  of  red  lead  and  1  of 
ground  flints ;  the  whole  fused  together  and  then  reduced  to  powder. 

Chrome  Green.  Triturate  together  in  a  mortar  equal  parts  of  chromate  of  potash  and 
flowers  of  sulphur :  put  the  mixture  into  a  crucible  and  fuse.  Pour  out  the  fluid  mass ; 
when  cool,  grind  and  wash  well  with  water  to  remove  the  sulphuret  of  potash  and  to 
leave  the  beautiful  green  oxide  of  chrome.  This  is  to  be  collected  upon  a  filter,  dried, 
rubbed  down  along  with  thrice  its  weight  of  a  flux,  consisting  of  4  parts  of  red  lead  and 
1  part  of  ground  flints  fused  into  a  transparent  glass ;  the  whole  is  now  to  be  melted 
and  afterward  reduced  to  a  fine  powder. 

Violet.  One  part  of  calcined  black  oxide  of  manganese,  one  of  zaffre,  ten  parts  of 
white  glass  pounded,  and  one  of  red  lead,  mixed,  fused,  and  ground.  Or  gold  purple 
(Cassius's  purple  precipitate)  with  chlorsilver  previously  fused,  with  ten  times  its 
weight  of  a  flux,  consisting  of  ground  quartz,  borax,  and  red  lead,  all  melted  together; 
solution  of  tin  being  dropped  into  a  large  qua  titv  of  water,  solution  of  nitrate  of 
silver  may  be  first  added,  and  then  solution  of  gold  in  agua  regia,  in  proper  proportion* 
.The  precipitate  to  be  mixed  with  flux  and  fused. 

Exhibition  Stained  Glass  Windows. — Leaded  work  with  medallions  and  ornamental 
work  of  the  early  Gothic  style ;  and  in  the  style  of  the  fourteenth  century,  the  figures 
being  St.  Peter  and  St.  Paul,  St.  George  and  Britannia;  armorial  decoration;  a  land- 
scape and  ornamental  work  suitable  for  a  dwelling  house.  Flowers  painted  and 
enamelled  on  a  large  plate  of  glass,  with  borders  ;  the  glass  having  been  burnt  in  a  kiln 
four  times. 

The  interest  attached  to  this  beautiful  art,  and  its  comparatively  recent  revival,  calls 
for  a  few  remarks.  Its  antiquity  is  undoubted.  Pliny  speaks  of  "  coloured  glasses 
made  to  imitate  precious  stones  and  gems,"  and  painted  glass  in  the  church  of  Notre 
Darae  at  Paris  is  described  as  early  as  the  sixth  centurv.  To  Suggerius  Abbot  of  St 
Denis,  in  1150,  is  probably  owing  the  reintroWuction  of  painted  glasses  in  churches.  How 
rapidly  his  example  was  followed,  is  proved  by  the  magnificent  glass  of  the  thirteenth 
century  abounding  on  the  continent,  and  partially  existing  in  this  country,  the  oldest 
examples  we  have  being  in  Canterbury  Cathedral.  At  first  the  ornaments  consisted  of  a 
mere  drapering  ;  then  rude  representations  of  saints  and  kings;  then  panels  of  various 
forms,  with  subjects  from  the  Testaments,  on  grounds  of  blue  or  ruby,  the  intermediate 
parts  filled  with  Mosaic  patterns  in  rich  colours,  and  the  whole  enclosed  within  a  coloured 
border.  In  later  styles  single  figures  predominated,  with  flowing  patterns  of  foliage  and 
later  still,  with  canopies  over  them.  Some  of  the  finest  works  are  by  French  and  Flemish 
artists ;  and  this  art  was  traditionally  known  to  the  early  Florentine  painter  Cimabue 
who  is  said  to  have  introduced  it  into  Italy.  Probably  our  actual  obligations  are  due  to 
our  Norman  neighbours,  as  a  necessary  appendage  to  their  architecture.  It  has  been  a 
popular  notion  thjtt  this  art  was  lost  to  us ;  such  is  not  the  case ;  it  has  indeed  been 
dormant,  but  nevei  extinct. 

STAMPING  OF  METALS.  The  following  ingenious  machine  for  manufacturing 
metal  spoons,  forks,  and  other  articles,  was  made  the  subject  of  a  patent  by  Jonathan 
Hayne,  of  Clerkenwell,  in  May,  1833.  He  employs  a  stamping-machine  with  dies,  ia 
which  the  hammer  is  raised  to  a  height  between  guides,  and  is  let  fall  by  a  trigger. 
He  prefers  fixing  the  protuberant  or  relief  portion  of  the  die  to  the  stationary  block  or 
bed  of  the  staropmg-machine,  and  the  counterpart  or  intaglio  to  the  falling  hammer 
or  ram. 

The  peculiar  feature  of  improvement  in  this  manufacture  consists  in  producing  the 
spoon,  ladle,  or  fork  perfect  at  one  blow  in  the  stamping-machine,  and  requiring  no 
further  manipulation  of  shaping,  but  simply  trimming  off  the  barb  or  fin,  and  polishing 
the  surface,  to  render  the  article  perfect  and  finished. 

Heretofore,  in  employing  a  stamping-machine,  or  fly-press,  for  manufacturing  spoons, 
ladles,  and  forks,  it  has  been  the  practice  to  give  the  impressions  to  the  handles,  and  to 


719 


STAMPING  OF  METALS. 


the  bowls  or  prongs,  by  distinct  operations  of  different  dies,  and  aAer  having  so  par. 
tially  produced  the  pattern  upon  the  article,  the  handles  had  to  be  bent  and  formed  by 
the  operations  of  filing  and  hammering.  ^  ^      »  j    j  ii«— 

By  his  improved  form  of  dies,  which,  having  curved  surfaces  and  bevelled  edges,  allow 
of  no  parts  of  the  faces  of  the  die  and  counter^ie  to  come  into  contact,  he  is  enabled  to 
produce  considerable  elevaUons  of  pattern  and  form,  and  to  bring  up  the  article  pertecl 
at  one  blow,  with  only  a  slight  barb  or  fin  upon  its  edge.  ,    ,.     /.  .     • 

In  the  accompanying  drawings,  fig.  1344  is  the  lower  or  bed  die  for  producing  m 
•peon,  seen  edgewise  j  fig.  1345  is  the  face  of  the  upper  or  counter^ie,  corresponding ; 

1345 


Jig.  1846.  IS  a  section,  taken  through  the  middle  of  the  pair  of  dies,  showing  the  space  in 
which  the  metal  is  pressed  to  form  the  spoon.  .      ^^ 

To  manufacture  spoons,  ladles,  or  forks  according  to  his  improved  process,  he  first 
forffea  out  the  ingot  into  flat  pieces,  of  the  shape  and  dimension  of  the  die  of  the 
intended  article ;  and  if  a  spoon  or  ladle  is  to  be  made,  gives  a  slight  degree  of  concavity 
to  the  bowl  part ;  but,  if  necessary,  bends  the  back,  in  order  that  it  may  lie  more  steadily 
and  bend  more  accurately,  upon  the  lower  die ;  if  a  fork,  he  cuts  or  otherwise  remove 
portions  of  the  metal  at  those  parts  which  will  intervene  between  the  prongs ;  and, 
Kving  thus  produced  the  rude  embryo  of  the  intended  article,  scrapes  its  entire  surface 
clean  and  free  from  oxidation-scale  or  fire-strain,  when  it  is  ready  to  be  introduced  mto 

the  stamping-machine.  ,  .  ,  .        ,  ^  ■    ax. 

He  now  fixes  the  lower  die  in  the  bed  of  the  stampmg-machme,  shown  at  a,  a,  in  the 

elevations  figs.  1347.  and  1348.,  and  fixes,  in  the  hammer  b,  the  upper  or  counter-dw 

c,  accurately  adjusting  ti.om  both,  so  that  they  may  correspond  exactly  when  brought 

loeether.     He  then  places  the  rudely-formed  article  above  described  upon  the  lower 

^  die,    and    having    drawn    up    the 

1347  hammer   to  a   sufficient   elevation 

by  a  windlass  and  rope,  or  othei 
ordinary  means,  lets  go  the  trigger, 
and  allows  the  hammer  with  the 
counter-die  to  fall  upon  the  undei 
die,  on  which  the  article  is  placed ; 
when,  by  the  blow  thus  given  to 
the  metal,  the  true  and  perfect 
figure  and  pattern  of  the  spoon, 
ladle,  or  fork  is  produced,  and 
which,  as  before  said,  will  only 
require  the  removal  of  the  slight 
edging  of  barb  or  fin,  with  polish- 
ing, to  finish  it. 

On  striking  the  blow,  in  the 
operation  of  stamping  the  article, 
the  hammer  will  recoil  and  fly  up 
some  distance,  and  if  allowed  16 
fall  again  with  reiterated  blows, 
would  injure  both  the  article  and 
the  dies;  therefore,  to  avoid  this 
inconvenience,  he  causes  the  ham- 
mer on  recoiling  to  be  caught  by 
a  pair  of  palls  locking  into  rack* 
I  on  the  face  of  the  standards,  seen 

in  figsVlUl  and   1348^     In  fig.  1347  the  hammer  6.  of  the  stamping-machine,  is  seen 


STARCH. 


711 


raised  and  suspended  by  a  rope  attached  to  a  pair  of  jointed  hooks  or  holders  d,  J,  the 
lower  ends  of  which  pass  into  eyes  «,  «,  extending  from  the  top  of  the  hammer.  When 
the  lever  or  trigger  t  is  drawn  forward,  as  in^fg.  1046,  the  two  inclined  planes  g,  g, 
on  the  axle  A,  press  the  two  legs  of  the  holders  d,  rf,  inward,  and  cause  their  hooks  or 
lower  ends  to  be  withdrawn  from  the  eyes  e,  e,  when  the  hammer  instantly  falls,  and 
brings  the  dies  together :  such  is  the  ordinary  construction  of  the  stamping-machine. 

On  the  hammer  falling  from  a  considerable  elevation,  the  violence  of  the  blow  causes 
it  to  recoil  and  bound  upwards,  as  before  mentioned ;  it  therefore  becomes  necessary  to 
catch  the  hammer  when  it  has  rebounded,  in  order  to  prevent  the  dies  coming  again  to- 
gether; this  is  done  by  the  following  mechanism: — 

Two  latch  levers  t,  i,  are  connected  by  joints  to  the  upper  part  of  the  hammer,  and 
two  pall  levers  k,  k,  turning  upon  pins,  are  mounted  in  the  bridge  /,  afiixed  to  the  ham- 
mer. Two  springs  m,  m,  act  against  the  lower  arms  of  these  levers,  and  press  them 
outwards,  for  the  purpose  of  throwing  the  palls  at  the  lower  ends  of  the  levers  into  the 
teeth  of  the  ratchet  racks  n,  n,  fixed  on  the  sides  of  the  upright  standards. 

Previously  to  raising  the  hammer,  the  upper  ends  of  the  pall  levers  fr,  are  drawn  back, 
and  the  latches  t,  being  brought  down  upon  them,  as  in  fig.  1045,  the  levers  k  are  con- 
fined, and  their  palls  prevented  from  striking  into  the  side  racks ;  but  as  the  hammer 
falls,  the  ends  of  the  latches  t  strike  upon  the  fingers  o,  o,  fixed  to  the  side  standards,  and 
liberate  the  palls,  the  lower  ends  of  which,  when  the  hammer  rebounds,  after  stamping, 
catch  into  the  teeth  of  the  racks,  as  in  fig.  1046,  and  thereby  prevent  the  hammer  from 
again  descending. 

STANNATE  OR  STANNITE  OF  POTASH  AND  SODA.  Stannates  and  stannitea 
of  alkalis  are  valuable  mordants  in  calico  printing,  and  are  prepared  by  the  patented  plan 
of  Messrs.  Greenwood,  Church  and  Barnes,  as  foUowa  For  the  staunate  of  soda:  2S 
pounds  of  caustic  soda  are  first  put  into  an  iron  crucible,  heated  to  a  low  red  heat,  till  the 
hydrate  be  produced ;  to  which  8  pounds  of  nitrate  of  soda  and  4  pounds  of  common  salt 
are  introduced.  When  the  mixture  is  at  a  ^uxing  heat,  10  pounds  of  feathered  block  tin 
are  added,  and  it  is  stirred  with  an  iron  rod.  The  mass  now  becomes  dark  coloured,  and 
pasty,  and  ammonia  is  given  off  (the  tin  decomposing  the  water  of  the  hydrated  soda  and 
part  of  the  nitrate  of  soda.)  The  stirring  is  continued,  as  well  as  the  heat,  till  deflagra- 
tion takes  place,  and  the  mass  becomes  redhot,  and  pasty.  Tliis  product  is  stannate  of 
eoda.     It  may  be  purified  by  solution  and  crystallization. 

Stannite  of  soda  is  made  by  putting  4  pounds  of  common  salt,  13^^  pounds  of  caustic 
soda,  and  4  pounds  of  feathered  block  tin  into  a  hot  iron  crucible  over  a  fire,  and  stirring 
and  boiling  to  dryness,  and  as  long  as  ammonia  is  given  off  What  remains  is  stannite 
of  soda. 

To  produce  the  tin  preparing  Hqnor,  3  pounds  of  stannate  of  soda  are  dissolved  in  one 
gallon  of  boiling  water,  and  3  gallons  or  more  of  cold  water,  to  bring  it  to  the  required 
strength.  The  stannite  of  soda  is  treated  in  the  same  way.  The  potash-stannate  and 
stannite  are  prepared  in  like  manner.  These  dilute  liquors  are  thus  prepared  (or  the 
dyers  and  printers. 

STARCH  (jlmidorij  Fecule,  Fr;    Starke,  Germ.),  is  a  white  pulverulent  substance, 
composed  of  microscopic  spheroids,  which  are  bags  containing  the  amylaceous  matter. 
It  exists  in  a  great  many  different  plants,  and  varies  merely  in  the  form  and  size  of  its 
microscopic  particles ;  as  found  in  some  plants,  it  consists  of  spherical  particles      i      of 
an  inch  in  diameter;  and  in  others,  of  ovoid  particles,  of  ^i_  or  -i_  of  an  inch.     It  oc- 
curs, 1.  in  the  seeds  of  all  the  acotyiedinous  plants,  among  which  are  the  several  species  of 
corns,  and  those  of  other  graminea ;   2.  in  the  round  perennial  tap  roots,  which  shoot 
np  an  annual  stem  ;  in  the  tuberose  roots,  such  as  potatoes,  the  Convolvulus  batatas  and 
edulitfihe  HeliatUhus  ivherosus,  the  Jatropha  tnanihot,  &c.,  which  contain  a  great  quantity 
of  it ;    3.  in   the  stems  of  several   monocotyledinous   plants,  especially  of  the   palm 
tribe,  whence  sago  comes ;    but  it  is  very  rarely  found  in  the  stems  and  branches  of 
the  dicotyledinous  plants;    4.  it  occurs  in  many  species  of  lichen.     Three  kinds  of 
starch  have  been  distinguished  by  chemists ;  that  of  wheat,  that  called  inuline,  and  lichen 
starch.     These  three  agree  in  being  insoluble  in  cold  water,  alcohol,  ether,  and  oils,  and 
in  being  converted  into  sugar  by  either  dilute  sulphuric  acid  or  diastase.     The  main 
difference  between  (hem  consists  in  their  habitudes  with   water  and  iodine.     The  first 
forms  with  hot  water  a  mucilaginous  solution,  which  constitutes,  when  cold,  the  paste 
of  the  laundress,  and  is  tinged  blue  by  iodine;  the  second  forms  a  granular  precipitate, 
when  its  solution  in  boiling-hot  water  issuflered  to  cool,  which  is  tinged  yellow  by  iodine; 
the  third  affords,  by  cooling  the  concentrated  solution,  a  gelatinous  mass,  with  a  clear  liquoi 
floating  over  it,  that  contains  little  starch.     Its  jelly  becomes  brown-gray  with  iwJine. 
1.  Ordinary  starch. — This  may  be  extracted  from  the  following  grains : — wheat,  rve^ 


712 


STARCH. 


l».rlpv  oftts  buckwheat,  rice,  maize,  miUet,  spelt ;  from  the  siliquosc  seeds,  as  peas  beans, 
S^fle's  Ic'   ^STtuSeVous  knd  taproots,  as  those  of  the  potato,  the  orchis,  manioc,  arrojjr 
«St    bimti    ic.     Different  kinds  of  corn  yield  very   variable  quantities  of  starch* 
Wh^aSe/s  1^  ihis  respect,  according  to  the  varieties  of  the  plant,  as  well  as  the  soil 

'^z:Lrp^;^^:!T^  ^,-p^r'  Sid\tTavr 

fiicture  of  starch,  as  this  constituent  suffers  less  injury  than  the  gluten ;  and  it  may  be 

^f  '^l'::XS''Z^^^^^^^  siAed  clean,  is  to  be  put  into  cistern^ 

eovered  with  soft  water,  and  left  to  steep  till  it  becomes  swollen  and  so  soft  as  to  be 
Slfly  crushed  between  Jhe  fingers.  It  is  now  to  be  taken  out,  and  ""«^^«^^  -  ^  ^^ 
water  of  a  temperature  equal  to  that  of  malting-barley,  whence  it  is  to  be  transferred 
Jto  Lgs.  whXare  placed  in  a  wooden  chest  containing  so.e  water,  and  exposed  to 
Srono^prersure.  The  water  rendered  milky  by  the  starch  being  drawn  off  by  a  ap, 
feshwaler  I  poured  in,  and  the  pressure  is  repeated.  Instead  of  putting  the  swollen 
«^iT»rnto  bairsome  prefer  to  griid  it  under  vertical  edge-stones,  or  between  a  pair  of 
&ntal  roflers,  and'then  to  lly  it  in  a  cistern  and  separate  the  ^tarchj  liqj^^^^^^^^ 
triation  with  successive  quantities  of  water  well  stirred  up  with  it.  Ihe  '^f  »d"*7  "">^ 
iS-  n  the  sacks  or  cisterns  contains  much  vegetable  albumen  and  gluten,  along  with  the 
husS;  when  exposed  to  fermentation,  it  affords  a  small  quantity  of  starch  of  rather  in- 

'^  Th^abovImiJky  liquor,  obtained  by  expression  or  elutriation,  is  run  into  large  CKtem^s 
where  it  deposits  stanch  in  layers  successively  less  and  less  dense;  the  upperm^t 
Iwitalnine  a  considerable  proportion  of  gluten.  The  supernatant  liquor  being  drawn 
X  aid  fresh  water  poured  oi  it,  the  whole  must  be  well  str red  up  allowed  again  to 
^ttle  and  the  surface- liquor  again  withdrawn.  This  washing  should  be  repeated  as 
toie  as  the  watef  takes  any  perceptible  color.  As  the  first  turbid  liquor  contains  a 
Sture  of  gluten,  suRar!  gum,  albumen,  &c.,  it  ferments  readily,  and  produces  a  certain 
Sn  of  finS^^  to  dissolve  out  the  rest  of  the  mingled  gluten,  and  thu. 

S?bWh  the  starch  It  is,  in  fact,  by  the  action  of  this  fermented  or  soured  water,  and 
Ltted  wasS^^^^^^^^^  After  the  last  deposition  and  decantation  there 

Ip^^ars  on  the  surface  of  the  starch  a  thin  layer  of  a  slimy  mixture  of  gluten  and  albu- 
me^  which  being  scraped  off,  serves  for  feeding  pigs  or  oxen ;  underneath  will  be  found 
Tsurlh  of  goS  quality  Th^  layers  of  different  sorts  are  then  taken  up  with  a  wooden 
Jhovel  tmnsfe^^  into  separate  cisterns,  where  they  are  agitated  with  water  and  passed 
Srough  fine  s  Jv^^  After  this  pap  is  once  more  well  settled,  the  clear  water  is  drawn 
Sff  the  stLchy  m^^^  is  taken  out,  and  laid  on  linen  cloths  in  wicker  baskets,  to  drain  and 
Seiome  partially  dry.  When  sufficiently  firm,  it  is  cut  nto  pieces,  which  are  spread  upon 
other  cloths,  and  thoroughly  desiccated  in  a  proper  drying-room,  which  in  winter  is  heat. 
Sbv  stoves  The  upper  surface  of  the  starch  is  generally  scraped,  o  remove  any 
fusty' matler  and  the  Resulting  powder  is  sold  in  that  state.  ,  Wheat  yields  upon  an 
average,  only  from  35  to  40  per  cent,  of  good  starch.    It  should  afford  more  by  skilful 

"Tirthil'country,  wheat  crushed  between  iron  rollers  is  laid  to  steep  in  as  much 
water  as  will  wet  it  'thoroughly ;  in  four  or  five  days  the  mixture  ferments,  soon  afterwards 
IS  ties  a^d  sTeady  to  be  washed  out  with  a  quantity  of  water  into  the  proper  ferment- 
Sgvas  The  common  time  allowed  for  the  steep,  is  from  14  to  20  days  The  nex 
SIcess  consists  in  removing  the  .stuff  from  the  vats  into  a  ^tout  round  basket  set 
Lross  a  back  below  a  pump.  One  or  two  men  keep  going  round  the  bask e  stirring 
up  the  stuff  with  strong  wooden  shovels,  while  another  keeps  P^^^J^.'^g  J^^^V^'?/" /ij 
firina  is  completely  washed  from  the  bran.  Whenever  the  subjacent  t>ack  is  fille^ 
the  liquor  is  taken  out  and  strained  through  hair  sieves  into  square  frames  or  m^ni^ 
where  it  is  allowed  to  settle  for  24  hours;  after  which  ^^^^  wa^er  is  run  off  from^^^^^ 
deposited  starch  by  plug  taps  at  different  levels  m  the  side.  The  thin  stuff  called  ,^^". 
IZn  the  surface  of  the  starch,  is  removed  by  a  tray  of  a  peculiar  form.  Fresh  water 
is  now  introduced,  and  the  whole  being  well  mixed  by  proper  agitation,  is  then  poured 
npon  fine  silk  sieves.  What  passes  through  is  allowed  to  settle  for  24  hours;  the 
liquor  being  withdrawn,  and  then  the  slimes,  as  before,  more  water  *«  «f '" J/ff^  "' 
with  agitatfon,  when  the  mixture  is  again  thrown  upon  the  silk  sieve.  The  milky  liquor 
I  now  suffered  to  rest  for  several  days,  4  or  5,  till  the  starch  becomes  settled  pretty 
firmly  at  the  bottom  of  the  square  cistern.  If  the  starch  is  to  have  the  blue  tint, 
called  Poland,  fine  smalt  must  be  mixed  in  the  liquor  of  the  last  sieve,  in  the  proportion 
of  two  or  three  pounds  to  the  cwt.  A  considerable  portion  of  these  shnes  may,  by  good 
manao^ement,  be  worked  up  into  starch  by  elutriation  and  straining. 
The  starch  is  now  fit  for  fcoxrng,  by  shovelling  the  cleaned  deposite  into  wooden  chests. 


STARCH. 


713 


about  4  feet  long,  12  inches  broad,  and  6  inches  deep,  perforated  throughout,  and  lined 
with  Ihin  canvass.  When  it  is  drained  and  dried  into  a  compact  mass,  it  is  turned  out  by 
inverting  the  chests  upon  a  clean  table,  where  it  is  broken  into  pieces  four  or  five  inches 
square,  by  laying  a  ruler  underneath  the  cake,  and  giving  its  surface  a  cut  with  a  knife, 
after  which  the  slightest  pressure  with  the  hand  will  make  the  fracture.  These  pieces 
are  set  upon  half-burned  bricks,  which  by  their  porous  capillarity  imbibe  the  moisture  of 
the  starch,  so  that  its  under  surface  may  not  become  hard  and  horny.  When  sufficiently 
dried  upon  the  bricks,  it  is  put  into  a  stove,  (which  resembles  that  of  a  sugar  refinery,) 
and  left  there  till  tolerably  dry.  It  is  now  removed  to  a  table,  when  all  the  sides  are 
carefully  scraped  with  a  knife ;  it  is  next  packed  up  in  the  papers  in  which  it  is  sold ; 
these  packages  are  returned  into  the  stove,  and  subjected  to  a  gentle  heat  during  some 
days ;  a  point  which  requires  to  be  skilfully  regulated. 

Mr.  Samuel  Hall  obtained  a  patent  for  bleaching  starch  by  chloride  of  lime  in  1821. 
Chlorine  water  would  probably  be  preferable,  and  might  prove  useful  in  operating  upon 
damaged  wheat. 

The  sour  water  of  the  starch  manufacture  contains,  according  to  Vauquelin,  acetic  acid, 
acetate  of  ammonia,  alcohol,  phosphate  of  lime,  and  gluten. 

During  the  drying,  starch  splits  into  small  prismatic  columns,  of  considerable  regulari- 
ty. When  kept  dry,  it  remains  unaltered  for  a  very  long  period.  When  it  is  heated  to 
a  certain  decree  in  water,  the  envelopes  of  its  spheroidal  particler  burst,  and  the  farina 
forms  a  mucilaginous  emulsion,  magma,  or  paste.  When  this  apparent  solution  is  eva- 
porated to  dryness,  a  brittle  horny-looking  substance  is  obtained,  quite  different  in  aspect 
from  starch,  but  similar  in  chemical  habitudes.  When  the  moist  paste  is  exposed  for  two 
or  three  months  to  the  air  in  summer,  the  starch  is  converted  into  sugar  to  the  amount 
of  one  third  or  one  half  of  its  weight,  into  gum,  and  gelatinous  starch  called  amidine  by 
De  Saussure,  with  occasionally  a  resinous  matter.  This  curious  change  goes  on  even  in 
close  vessels. 

Starch  from  poiatoes.-^From  the  following  table  of  analyses,  it  appears  that  potatoes 
contain  from  24  to  30  per  cent,  of  dry  substance  : — 


Red  potatoes,  - 
Germinating  potatoes,  - 
Kidney  potatoes. 
Large  red  potatoes, 
Sweet  potatoes, 
Peruvian  potatoes, 
English  potatoes, 
Parisian  potatoes. 


fitow^Vi 

Fihrons  Pa- 

Vegetable 

renchyma. 

Albumen 

150 

7-0 

1-4 

15-2 

6-8 

1-3 

9-1 

8-8 

0-8 

12-9 

6-0 

0-7 

15-1 

8-2 

0-8 

150 

5-2 

1-9 

12-9 

6-8 

M 

13-3 

6-8 

0-9 

Gum,  Sui^ar, 
and  Salts. 

Water 

9-2 

75-0 

3-7 

730 

— 

81-3 

— 

780 

— 

74-3 

1-9 

760 

1-7 

77-5 

4-8 

73-1 

Manufacture  of  potato  starch.— The  potatoes  are  first  washed  in  a  cylindrical  cage 
formed  of  wooden  spars,  made  to  revolve  upon  a  horizontal  axis,  in  a  trough  fiJled  with 
water  to  the  level  of  the  axis.  They  are  then  reduced  to  a  pulp  by  a  rasping  machine 
similar  to  that  represented  in  Jigs.  1047,  1048,  where  a  is  a  wooden  drum  covered  with 
sheet-iron,  roughened  outside  with  numerous  prominences,  made  by  punching  out  holes 
from  the  opposite  side.  It  is  turned  by  a  winch  fixed  upon  each  end  of  the  shaft.  The 
drum  is  enclosed  in  a  square  wooden  box,  to  prevent  the  potato-mash  from  being  scatter- 
cd  alwut.  The  hopper  b  is  attached  to  the  upper  frame,  has  its  bottom  concentric  with 
the  rasp-drum,  and  nearly  in  contact  with  it.  The  pulp  chest  c  is  made  to  slide  out,  so 
as  when  full  to  be  readily  replaced  by  another.  The  two  slanting  boards  d,  d,  conduct 'the 
pulp  into  it.  A  moderate  stream  of  water  should  be  made  to  play  into  the  hopper  upon 
the  potatoes,  to  prevent  the  surface  of  the  rasp  from  getting  foul  with  fibrous  matter. 
Two  men,  with  one  for  a  relay,  will  rasp,  with  such  a  machine,  from  2*  to  3  tons  of  po- 
tatoes in  12  hours.  ^^ 

The  potato  pulp  must  be  now  elutriated  upon  a  fine  wire  or  hair  seive,  which  is  set 
npon  a  frame  in  the  mouth  of  a  large  vat,  while  water  is  made  to  flow  upon  it  from  a 
spout  with  many  jets.  The  pulp  meanwhile  must  be  stirred  and  kneaded  by  the  hand, 
or  by  a  mechanical  brush-agitator,  till  almost  nothing  but  fibrous  particles  are  left  upon 
the  sieve.  These,  however,  generally  retain  about  five  per  cent,  of  starch,  which  cannot 
be  separated  in  this  way.  This  parenchyma  should  therefore  be  subjected  to  a  separate 
rasping  upon  another  cylinder.  The  water  turbid  with  starch  is  allowed  to  settle  for  some 
time  in  a  back ;  the  supernatant  liquor  is  then  run  bj  a  cock  into  a  second  back,  and  aftef 


it 


714 


STARCH. 


1349 


1350 


some  time  into  a  tnird,  whereby  the  whole 
starch  will  be  precipitated.  The  finest 
powder  collects  in  the  last  vessel.  The 
starch  thus  obtained,  containing  33  per 
cent,  of  water,  may  be  used  either  in  th« 
moist  state,  under  the  name  of  green /eat- 
la,  for  various  purposes,  as  for  the  prepa- 
ration of  dextrine,  and  starch  sirup ;  or 
it  may  be  preserved  under  a  thin  layer  of 
water,  which  must  be  renewed  from  time 
to  time,  to  prevent  fermentation ;  or  last- 
ly, it  may  be  taken  out  and  dried. 

In  trials  made  with  St.  Etienne's  rasp 
and  starch  machinery,  in  Paris,  which 
was  driven  by  two  horses,  nearly  18  cwtg. 
of  potatoes  were  put  through  all  the  re- 
quisite operations  in  one  hour,  including 
the  pumping  of  the  water.  The  product 
in  starch  amounted  to  from  17  to  18  per 
cent,  of  the  potatoes.  The  quicker  the 
process  of  potato-starch  making,  the  bet- 
ter is  its  quality. 

Starch  from  certain  foreign  plants.--l.  From  the  pith  of  the  sago  palm.    See  Saoo. 
2    From  Xe  roots  of  the  Maranta  arundinacea,  of  Jamaica    the  Bahamas,  and  other 
wSt  IndS  islands,  the  powder  called  arrow-root  is  obtained,  by  a  process  analogous  to 

'^'i'YZ^^r^^'^T Manioc,  ^l^^^  also  grows  in  the  West  Indies  as  well  as  in 
Africa, Te  cLava  is  procured  by  i  similar  process.  The  juice  of  this  plant  is  poison- 
^s  f^om  whTch  the  wholesome  starch  is  deposited.  When  dried  with  stirrmg  upon  hot 
Ton  Dlales  it  a-glomerates  into  small  lumps,  called  tapioca  ;  being  a  gummy  fecula. 

Z  characters  of  the  different  varieties  of  starch  can  be  learned  only  from  microscopic 
observation;  by  which  means  also  their  sophistication  or  admixture  maybe  readily  as- 

^^sStfrom  whatever  source  obtained,  is  a  white  soft  po^^er,  which  feels  crispy,  like 
flowe  s  of  sXhur,  when  pressed  between  the  fingers;  it  is  destitute  of  taste  and  smell, 
nndian-eable  in  the  atmosphere,  and  has  a  specific  gravity  of  1-53.  I  have  already  de- 
wr'bed'the  particles  as  spheroid^  enclosed  in  a  membrane.  The  potato  contains  some 
of  he  lar'e^st,  and  the  millet  the  smallest.  Potato  starch  consists  of  truncated  ovoids^ 
rai^lngln'siz^from^  to^V^ofaninch;  arrow-root,  of  ovoids  varying  m  size  from 

1  to  J—  of  an  i2;  flowerstarch,  of  insulated  globules  about  ^^o  «"  "^  '"'^' 
ea^ava  ^'^simular  globules  assembled  in  groups.  These  measurements  I  have  made 
^trrioodTCmftic  microscope,  and  a  divided  glass-slip  micrometer  of  TuUy 

For  the  saccharine  changes  which  starch  undergoes  by  the  action  oMiastase,  see  Fer- 

■^^.S;  a  species  of  starch  obtained  ^^om  Iceland  moss,  (Ce/rarm^^^^^^^^ 

as  in-line,  from  elecampane,  (Inula  Helmium,)  are  rather  objects  of  chemical  curiosity, 

"^  T^lTalTnd  o7;tarch  made  in  order  to  be  converted  into  gum  for  the  calico-printer. 
This  conversion  having  been  first  made  upon  the  great  scale  in  this  country,  has  occa- 
sioied  the  pr^uct  to  be  called  British  gum.  The  following  is  the  process  pursued  m  • 
Trge  and  wdl  conducted  establishment  near  Manchester.  A  range  of  four  wooden  cis- 
SrSs  each  about  7  or  8  feet  square,  and  4  feet  deep,  is  provided.  Into  each  of  them  2000 
gallons  of  waTer  being  introduced,  12i  loads  of  flour  are  stirred  in.  This  mixture  is  set 
to  ferment  upon  old  leaven  left  at  the  bottom  of  the  backs,  during  2  or  3  days.  Thj 
intents  are?hen  stirred  up,  and  pumped  off  into  3  stone  cisterns  7  feet  square  and  4 
feet  deep ;  as  much  water  being  added,  with  agitation,  as  will  fill  the  cisterns  to  the  brim. 
In  the  course  of  24  hours  the  starch  forms  a  firm  depos.te  at  the  bottom ;  and  the  water 
is  then  svphoned  off.  The  gluten  is  next  scraped  from  the  surface  and  the  starch  if 
transferred  into  wooden  boxes  pierced  with  holes,  which  may  be  lined  with  coarse  cloth, 
or  not,  at  the  pleasure  of  the  operator.  ^      .*    j      •     „  i„«i,- 

The  starch,  cut  into  cubical  masses,  is  put  into  iron  trays,  and  set  to  dry  m  a  large 
apartment,  two  stories  high,  heated  by  a  horizontal  cylinder  of  cast  iron  traversed  by  he 
flame  of  a  furnace.  The  drying  occupies  two  days.  It  is  now  ready  for  eonvers  ja 
fnto  -urn  for  which  purpose  it  is  put  into  oblong  trays  of  sheet  iron,  and  heated  to  the 
lemperrii  e  of  300°  F.  in  a  cast-iron  oven,  which  holds  four  of  these  trays.  Here  ,t 
Srete«r^nto  irregular  semi-transparent  yellow-brown  lumps,  which  are  ground  into 
fiTfloTr  between  mill  stones,  and  in  this  state  brought  to  the  market  ^n  this  roasted 
starch,  tbe  vesicles  being  burst,  their  contents  become  soluble  m  cold  water,    iiritiali 


STARCH. 


716 


^m  is  not  convertible  into  sugar,  as  starch  is,  by  the  action  of  dilute  sulphuric  acid ;  oor 
into  mucic  acid,  hj  nitric  acid  ;  but  into  the  oxalic ;  and  it  is  tinged  purple-red  by  iodine. 
It  is  composed,  m  100  parts,  of  35*7  carbon,  6'2  hydrogen,  and  58*1  oxygen;  while 
starch  is  composed  of,  43'5  carbon,  6-8  hydrogen,  and  49'7  oxygen. 

To  prove  whether  starch  be  quite  free  from  gluten,  or  whether  it  be  mixed  with  any 
wheat  flour,  diffuse  12  grains  of  it  through  six  ounces  of  water,  heat  the  mixture  to 
boiling,  stirring  it  meanwhile  with  a  glass  slip.  If  the  starch  be  pure,  no  froth  will  be 
seen  upon  the  surface  of  the  pasty  fluid ;  or  if  any  be  produced  during  the  stirring,  it 
will  immediately  subside  after  it ;  but  if  the  smallest  portion  of  gluten  be  present,  much 
froth  will  be  permanently  formed,  which  may  be  raised  by  stirring  into  the  appearance 
of  soap-suds. 

Starch  has  been  made  the  subject  of  a  patent  by  Mr.  Thomas  Berger,  of  Hack- 
ney, under  which  he  soaks  rice  in  caustic  alkali,  as  Mr.  Wickham  did  in  1824,  at 
successive  times,  levigates  it  into  a  cream,  adds  one  part  of  oil  of  turpentine  to  2000 
gallons  of  the  cold  mash,  stirs  the  mixture,  filters  or  strains  through  fine  lawn  sieves, 
settles,  neutralizes  with  dilute  sulphuric  acid,  and  adding  8  oz,  of  sulphate  of  zinc  to  each 
cwt.  of  starch,  stirs,  boxes,  and  finishes  as  usual.  One  is  apt  to  ask  what  purpose  the 
spirits  of  turpentine  can  serve  in  such  a  small  quantity,  except  it  be  to  prevent  ferment- 
ation.    He  also  suggests  electricity ;  but  how  to  use  it  he  says  not. 

In  June,  1841,  Mr.  W.  T.  Berger  obtained  a  patent  for  manufacturing  starch  by  the 
agency  of  an  alkaline  salt  upon  rice.    He  prefers  the  carbonates  of  potash  and  soda. 

In  January,  1839,  M.  Pierre  Isidore  Verdure  obtained  a  patent  for  making  starch, 
the  chief  object  of  which  was  to  obtain  the  gluten  of  the  wheat  in  a  pure  state,  as  a 
suitable  ingredient  in  making  bread,  biscuits,  <fec.  He  works  wheat  flour  into  dough 
by  a  machine,  kneads  it,  washes  out  the  starch  by  streams  of  cold  water,  a  process 
long  known  to  the  chemist,  and  purifies  the  starch  by  fermentation  of  the  superjacent 
water.     I  can  see  nothing  new  in  his  specification. 

Mr.  Jones's  patent,  of  date  April,  1840,  is  based  upon  the  purification  of  the  starch 
of  rice  and  other  farinaceous  matters  by  means  of  caustic  alkali.  He  macerates  100 
lbs.  of  ground  rice  in  100  gallons  of  a  solution  composed  of  200  grains  of  caustic  soda 
or  potash  to  a  gallon  of  water,  stirs  it  gradually  till  the  whole  be  well  mixed ;  after  24 
hours  draws  off  the  superjacent  liquid  solution  'of  gluten  in  alkali,  treats  the  starchy 
deposit  with  a  fresh  quantity  of  weak  caustic  lye,  and  thus  repeatedly,  till  the  starch 
becomes  white  and  pure.  The  rice  before  being  ground  is  steeped  for  some  time  in  a 
like  caustic  lye,  drained,  dried,  and  sent  to  the  mill. 

Starch  is  made  from  wheal  flour  in  a  like  way.  The  gluten  may  be  recovered  for 
use  by  saturating  the  alkaline  solution  with  sulphuric  acid,  washing  and  drying  the  pre- 
cipitate. 

Mr.  James  Colman,  by  his  patent  invention  of  December,  1841,  makes  starch  from 
ground  maize  or  Indian  corn,  by  the  agency  either  of  the  ordinary  process  of  steeping 
and  fermenting,  or  of  caustic  or  carbonated  alkaline  lyes.  He  also  proposes  to  em- 
ploy dilute  muriatic  acid  to  purify  the  starchy  matter  from  gluten,  <fec. — See  NewioiCt 
Jwirnal,  C.  S.  xix.  246.;  xx.  184.  188. ;  and  xxl  173. 

The  manufacture  of  potato  flour  (fecule)  or  starch  in  France  and  Holland  has  been 
economised  to  such  a  degree  that  they  supply  this  country  with  it,  at  the  rate  of  8».  or 
10«.  a  hundredweight.  Fig.  1351.  represents  in  section  the  powerful  and  ingenious 
mechanical  grater,  or  rasp  (rape)  now  used  in  Franca  a  a,  is  the  canal,  or  spout, 
along  which  the  previously  well-washed  potatoes  descend ;  b  b,  is  the  grater,  composed 
of  a  wooden  cylinder,  on  whose  round  surface  circular  saw  rings  of  steel,  with  short 
sharp  teeth,  are  planted  pretty  close  together.  The  greater  the  velocity  of  the 
cylinder,  the  finer  is  the  pulp.  A  cylinder  20  inches  in  diameter  revolves  at  the  rate  of 
from  600  to  900  times  in  a  minute,  and  it  will  convert  into  pulp  from  14  to  15  hecto- 
litres (about  300  imperial  gallons)  of  potatoes  in  an  hour.  Potatoes  contain  from  15 
to  22  per  cent  of  dry  fecula.  The  pulp,  after  leaving  the  rasp,  passes  directly  into  the 
apparatus  for  the  preparation  of  the  starch,  c  c,  is  a  wooden  hopper  for  receiving  the 
falling  pulp,  with  a  trap  door,  d,  at  bottom,  e,  is  the  cylinder-sieve  of  M.  Etienne; 
/  a  pipe  ending  in  a  rose  spout,  which  delivers  the  water  requisite  for  washing  the  pulp, 
and  extracting  the  starch  from  it ;  g  g,  &  diaphragm  of  wire  cloth,  with  small  meshes, 
on  which  the  pulp  is  exposed  to  the  action  of  the  brushes  a  a,  moving  with  great  speed, 
whereby  it  gives  out  its  starchy  matter,  which  is  thrown  out  by  a  side  aperture  into  the 
spout  n.  Tlie  fecula  now  falls  upon  a  second  web  of  fine  wire-cloth,  and  leaves  upon  it 
merely  some  fragments  of  the  parenchyma  or  cellular  matter  of  the  potato,  to  be  turned 
out  by  a  side  opening  in  the  spout  n.  The  sift'ing  or  straining  of  the  starch  likewise 
takes  place  through  the  sides  of  the  cylinder,  which  consist  also  of  wire-cloth ;  it  ia 
collected  into  a  wooden  spout,  m,  and  is  thence  conducted  into  the  tubes  o  o,  to  be  de- 
posited and  washed,  p,  is  a  mitre-toothed  wheel-work  placed  on  the  driving-shaft,  and 
gives  motion  to  the  upright  axis  or  spindle,  q  q,  which  turns  the  brushes,  %  i. 


ir 


716 


STARCHING  APPARATUS. 


Starch  prepared  from  rice  or  maize  by  alkali  ia  said  not  to  require  boiling— a  point  of 
great  importance  in  its  use;  and.  being  less  hygrometric  than  wheat  starch,  retains  a  more 
Srmanent  stiffness  and  glaze.  The  rough  starch  obtained  m  the  process  is  valuable  for 
feeding  purposes,  and  for  stiffening  coarse  fabrics. 

STARCHING  and  STKAM-DayrNO  Appaeatus.  The  system  of  hollow  cylinders  for 
dryin-  goods  in  the  processes  of  bleaching  or  calico-printing,  is  represented  in  h-^^^^ 
bl  longitudinal  section,  and  in  Jig.  1353.  in  a  top  view;  but  the  cylinders  are  supposed 
to  be  broken  off  in  the  middle/as  it  was  needless  to  repeat  the  parts  at  the  other  end, 
which  are  sufficiently  shown  in  the  section.  .      ,    j         *•»  „«^ .  ^  o 

A  ia  the  box  containing  the  paste,  when  the  goods  are  to  be  starched  or  stiffened ;  a  a 
wiich.  when  it  is  desired  to  turn  the  machine  by  hand,  though  it  is  always  raov«d  bv 
power  in  considerable  factories;  6,  is  the  driving  pinion ;d,  f,  two  brass  rollers  with 
dhafts.  the  undermost  of  which  is  moved  by  the  wheeU.  in  geer  with  the  pimon  6 
The  uppermost  roller  d',  is  turned  by  the  friction  with  the  former,  d,  being  pressed  upon 
it  by  Sfe  weighted  leve^  h;  e  is  the  trough  filled  with  the  paste,  which  rests  upon  the 
bars /,  and  mav  be  placed  higher  or  lower  by  means  of  the  adjusting  ^^'^^^d^.^^^^'tll 
aa  the  roller  d  is  to  be  plunged  more  or  less  deeply.     A  brass  roller  .  serves  to  force  dowu 

the  cloth  into  the  paste.  ,   .     .       ,  i  i  m.^   ii„«  ^*..,no  /^» 

B,  is  the  drying  part  of  the  machine:  k,  k,  its  iron  frammg;  /,  ?,  Ac,  five  drums,  or 

hollow  copper  cylinders,  heated  with  steam:  m,  m,  m.  <fec  sma  l  <=«PP7'  ^/^^f;.^" 
pairs,  turnilig  freely  on  shafts  under  the  former,  for  stretching  the  goods  and  ainng 
them  durins  their 'passage  through  the  machine:  n,  n,  is  the  mam  steam-pipe  from 
which  braidi  off  small  copper  tubes,  o.  o.  Ac,  which  conduct  the  steam  through 
Ttuffing  boxes  into  the  cavity  of  the  drying-drums.  There  are  similar  tubes  upon  the 
other  ends  of  the  drums,  for  discharging  the  condensed  water  through  similar  s  uffin^- 
boxes:  q,  9,  are  valves,  opening  internally,  for  admitting  the  air  ^»^*^°t^^\^*^%«^^,X 
token  ort-  or  becomes  feeble,  to  prevent  the  drums  from  being  crushed  by  the  unba- 
lanced  pressure  of  the  atmosphere  upon  their  external  surfaces 

o  is  (he  clothbeam.  from  which  the  starching  roller  draws  forwards  the  goo<!«' f' ^« 
two  rollers,  of  which  the  lower  is  provided  with  a  band-pulley  or  rigger  driven  by  a 
L^ilar  pulley  fixed  up<,n  the  shaft  of  the  starching  roller  (i  .  These  two  ^^\«"  P^ 
th"  gootk  through  the  drying  machine,  and  then  let  them  fall  either  upon  a  table  or  th« 

floor. 


STATUARY. 


TIT 


STATUARY,  cast  in  zinc,  bronzed;  and  in  other  metals. — ^This  ia  a  new  branch  of 
art  h\tely  sprung  up  in  Birmingham,  which  displays  equal  constructive  economy  and 
taste.  Bronze  varies  in  its  composition,  according  to  the  taste  of  the  artist,  as  to  it« 
hardness  or  the  depth  of  its  colour.  A  very  excellent  bronze  is  formed  by  the  addition 
of  2  oz.  of  tin  to  16  of  copper. 

The  casting  of  a  bronze  statue  may  be  thus  described.  The  core  is  made  up  of  brick- 
Work  and  clay  until  a  rude  representation  of  the  intended  work  is  made ;  upon  this  tho 


718 


STEAM. 


sculptor  models  in  wax,  of  the  thickness  intended  for  the  metal,  all  the  details,  such  as 
the  features,  drapry,  Ac. ;  when  this  is  completed,  it  is  coated  with  loara  of  very  thin  con- 
sistency ;  then  foUow  repeated  solid  cdatings  of  clay,  <fec.,  until  a  shell  of  sufficient  strength 
to  bear  the  pressure  of  the  melted  metal  is  formed ;  the  whole  is  then  bound  together,  heat 
is  applied,  the  wax  is  melted  out,  and  a  space  thereby  left  for  the  introduction  of  the 
metal ;  suitable  runners  are  made  and  vents  to  allow  of  the  free  escape  of  air.  The  metal  is 
melted  in  reverberating  furnaces,  and  when  in  a  proper  condition,  the  plug  is  withdrawn, 
and  the  mould  filled.  After  being  allowed  to  remain  till  cool  it  is  opened,  the  rough- 
ness cleansed  off,  and  the  statue  is  completed.  The  peculiar  tinge  of  the  bronze  is 
acquired'by  exposure  to  the  air. 

A  bronze  of  nearly  the  same  tinge  is  given  to  brass  by  immersion  in  a  mixture  of 
spirits  of  salt  and  arsenic ;  the  metal  is  to  be  heated  previous  to  this  ;  the  article  is  after- 
wards brushed  with  black-lead,  and  after  being  again  heated,  is  coated  with  a  lacquer, 
composed  of  spirits  of  wine,  with  a  little  yellow  colouring  matter ;  the  shade  of  antiquity 
is  thus  imparted  in  a  few  minutes. 

The  establishment  of  Messrs.  Messenger  and  Son  is  one  of  the  oldest  in  the  trade  io 
Birmingham ;  it  has  been  in  existence  upwards  of  50  years :  it  was  one  of  the  earliest  to 
recognise  the  importance  of  the  union  of  art  with  mauufactures.  For  this  the  genius 
of  Flaxman  and  Chantrey  was  called  into  requisition ;  artists  celebrated  for  their  skill 
in  architectural  enrichment  were  also  employed  in  the  modelling  of  balustrades,  can- 
delabra, tripods,  <tc. 

STEAM,  is  the  vapour  of  hot  water ;  the  discussion  of  which  belongs  to  chemistry, 
physics,  and  engineering.  Certain  practical  applications  of  the  subject  will  be  found 
va  the  article  Evaporation.  _  _ 

Steam  ;  its  laws.  An  able  memoir  on  the  pressure  and  density  of  steam  was  laid  before 
the  Institute  of  Civil  Engineers  in  June,  1848,  by  Mr.  Pole,  C.  E.,  which  deserves  con- 
fidence for  its  accuracy  and  usefulness.  He  proposed  a  new  formula  for  the  relation 
between  these  two  mechanical  qualities,  applicable  particularly  to  engines  working 
with  high  pressure  steam  expansively. 

The  relations  between  the  elasticity,  temperature,  and  density  of  steam  have  long  been 
interesting  and  important  subjects  of  philosophical  research.    They  are  fully  discussed, 
and  represented  in  extensive  tables  in  PrechtVs  Technological   Encyclopcedia,  article 
■Ddmp/e. 

The  connection  of  the  two  former,  namely,  pressure  and  temperature,  with  each  other, 
has  excited  the  greatest  attention,  numerous  experiments  having  been  undertaken  to 
ascertain  the  values  of  them  at  all  points  of  the  scale,  and  many  formulae  proposed 
by  English  and  foreign  mathematicians,  to  express  approximately  the  relation  between 

them.  ,      ,      . 

The  pressure  and  temperature  being  known,  the  density,  or  what  answers  the  same 
purpose,  the  relative  volume,  compared  with  the  water  which  has  produced  it,  may  be 
deduced  by  a  combination  of  the  laws  of  Boyle  and  Gay  Lussac,  and  may  be  expressed 
algebraically  in  terms  of  the  pressure  and  temperature  combined ;  whence,  by  elimi- 
nating the  latter,  by  means  of  the  before  mentioned  formulae,  expressions  can  be  arrived 
at  which  will  connect  at  once  the  volume  with  the  pressure. 

But  there  are  several  difficulties  in  the  way  of  this  process,  the  equations  which  may 
be  thus  ootained  being  too  complicated  for  practical  use;  and  therefore,  since  it  is 
important  in  calculations  connected  with  steam  and  the  steam  engine,  to  find  a  tolerably 
accurate,  and  at  the  same  time  simple  rule,  which  shall  give  the  pressure  and  volume 
directly  in  terms  of  each  other,  the  empirical  method  has  been  resorted  to. 

The  paper  enumerates  three  formulae  given  for  this  purpose  by  M.  Navier  and  M.  de 
Pambour,  explaining  the  peculiar  cases  to  which  they  are  applicable,  and  those  in 
which  they  fail ;  and  the  author  then  proposes  a  fourth  expression,  which  is  intended  to 
meet  a  case  not  provided  for  by  either  of  the  others,  namely,  for  •'  condensing  engines 
working  with  high  pressure  steam  expansively,"  such  as  the  Cornish  and  Woulf's 
double  cylinder  engine.    The  equation  is, 


P= 


24250 
V-65 


24250 
or  reciprocally,  ¥==— p —  X65 

P  being  the  total  pressure  of  the  steam  in  lbs.  per  square  inch,  and  V  its  relative 
volume,  compared  with  that  of  its  constituent  water. 

These  formulse  may  be  adopted  without  considerable  error  throughout  the  range 
generally  required  in  such  engines,  viz.,  from  about  5  lbs.  to  65  lbs.  per  square  inch. 

Two  tables  are  then  given,  showing  the  pressure  and  volumes,  as  calculated  for  every 


STEAM. 


719 


.v5  lbs.  pressure  in  this  scale;  the^  show  a  comparison  of  the  results  of  the  four  formula 
with  each  other,  and  the  respective  amount  of  deviation  from  truth  in  each. 


The  greatest  error  ia, — 

By  M.  Navier's  formula 

M.  de  Pambour's  first  ditto 
"  •*    second  ditto 

The  new  formula 

The  mean  error  is, — 

By  M.  Navier's  formula 

M.  de  Pambour's  first  ditto 
"  "    second  ditto 

The  new  formula 


lbs. 
•    131  per  square  inch. 

-  412  « 

-  2-75  " 
.    0-71            « 


0-245  per  square  inch. 
1-42  « 

0-35  « 

00062        « 


The  tables  also  show :  — 

;«  li  '^f  ^*!u  "e7,,^o«*'°"Ja  "  nearer  the  truth  than  either  of  the  others,  taken  separately 
m  three-fourths  of  the  scale.  ^        ^ 

2.  That  it  is  nearer  than  all  three  combined  in  half  the  scala 
.^^  ?^^l  *^^  greatest  error  of  the  new  formula,  with  regard  to  the  pressures,  is  only 
about  half  as  great  as  that  of  the  most  correct  of  the  other  three 

4.  That  the  mean  error  is  only  one-fortieth  of  either  of  the  others,  and  equal  to  only 
about  one-tenth  of  an  ounce  per  square  inch.  ^    i  i"  umy 

6.  That  the  errors  in  the  volumes  are  much  less  numerous  and  important  with  the 
new  formula  than  with  either  of  the  others. 

6.  It  is  also  added,  that  the  new  expression  is  simpler  in  algebraical  form  than  the 
others ;  it  is  more  easily  calcu  ated  the  constants  are  easier  to  remember,  and  that  no 
alteration  of  the  constants  m  the  other  formulae  wiU  make  them  coincide  so  nearly  with 
the  truth  as  the  new  one  does.  ^ 

St^rn,  {sp/urical  state  of)  It  is  a  well  known  fact,  that  if  a  small  quantity  of  water 
^thrown  on  to  a  me  talhc  plate,  heated  to  a  temperature  approaching^dull  rednes^  the 
water  is  not,  as  might  have  been  expected,  rapidly  dissipated  in  vajSur,  but  ass^m^g 

of  tZ  W  J^'^r^'  ^T'  ''  '"'"l"'  ^"r^^"''  "^  «''g^*V  agitated'only  by  the  aSbf 
of  the  heat  sometimes  rolhng  over  the  surface  of  the  heated  plate.  It  is  evident  in  this 
case,  tha    the  water  is  not  contact  with  the  metal;  consequently  there  is  no  a^ioa 

JhJl^llTrTr  '"^A  u.P^'^^  ^^^'"i  '^'  ^"^^^  ^^^"  ^"  ^h'^'^hich  has  been  called 
the  spherical,  condition.     Although  m  close  proximity  to  a  plate  of,  it  might  be    red 

rpL^  ^^'  ^a'  ""•*"'  ^PP"^^  *^  ^".  ^'^^'^  ^°>  *"  ^^"*  206^0,  and  in  this  fondition  H 
remains,  undergoing  slow  evaporation,  until  the  metal  becomes  so  far  cooled  as  to  admit 
of  the  water  coming  into  contact  with  it;  when  this  occurs,  the  water  loses  its  sphericJ 

ircoZct  ZVr  '^'  TT'^'A'-  '''''  "'^'^^  ^^^*^^  -^*^1'  with  which  Tnowt 
m  contact,  and  it  is  instantly  dissipated  m  vapour. 

««i^  ^rf  'l?'''^^^^  interesting  experiments  have  been  made  in  connection  with  this 

cL^^of  LL^r'r^'  ^"^,n*^'  '''''^1'  ^r  ^^^"  f«""^^  «"  explanatio^of  thai 
W-  T/k^  kJ^P^"''?'.  '""^'^^  ""T'  "^^'  b»^  not  «'  '^  ^om^nt  of,  the  excessive 
heatmg  of  the  boiler.  It  is  assumed  that  in  these  cases  the  boiler  becomes  heated  to  a 
temperature  at  which  the  water  is  thrown  into  the  spherical  condl^Twhile  in  this 
s^a  every  lit  le  steam  IS  generated  but  as  soon  as  the'^boiler  has  cooled  to  a  p^"nt  at 

Txpltr  ^  "'"'  '^'  '"^^'"  ^"'"^"'^"^  "^  "  ^*^S«  ^^^""^^  of  steam  caS  the 

It  has   been   found   that  other  volatile  bodies  besides  water  are  similarlv  affected 

under  like  circumstances.     Thus,  ether,  alcohol,  iodine,  <fec.  assume  the  XriilS 

dition  when  thrown  mto  a  metallic  vessel  (a  platinum  crucible  for  insLnL)  iSedTto 

:^:^t^jr-s  t^z^t'J^^  tsf^trs 

Boutigny,  availing  himself'^j^:  ^''^  I^etJ^^^^^  £lr  rJTpable^f 

Suclble^   I'is'^xTeTiinrnf  ^f  '^t^-'  \™^*^-J  ^^  freezinrwaterTn  a  ^^d  hoi 

crucible.     Ihs    experiment    IS    performed    m    the   following   manner-  — Some  liauid 
anhydrous  sulphurous  acid   is  first  prepared,  by  passing   thf  dry  gi' thi^rh  a  tTbe 

tZTpll/  .^  ^  ^'""''a^  T'^'"'*"  ^^  '^f  *"^  «^^*^°<1  «>'lecting  t^he^ro^luTin  a  sn«U 
tube   sealed    at   one  end,  also   surrounded  with   a   freeyinir   m.'vfnri     ThL   i:^.,!^  !i 

»lph«rous  acid  Ms  at  14=  Fahr    and  therefore.  iHtTS  T^  Ja "v  iZt^t 

time  the  mouth  of  the  tube  must  be  sealed  at  the  blowpipe  flame.  '^A  thick  platinum 

^S   .l^^JT?- "fT'^?^''"'"  '?i  .''  *°  ^  '■««'«'?  ^  redness,  and  whil^  in  thU 
•t.te,  about  f  5  J  of  the  sulphurous  acd  is  to  be  rapidly  projected  out  of  the  tube  into 


720 


STEARIC  ACID. 


\ 
5 


the  crucible.  The  add  assumes  the  spherical  condition,  and  while  in  this  state  undergoes 
comparatively  slow  evaporation ;  the  lamp  is  now  quickly  withdrawn,  and  a  small  quan- 
tity of  water  thrown  into  the  crucible  with  a  syringe.  The  temperature  of  the  crucible 
is  reduced  by  the  introduction  of  the  water,  so  as  to  cause  the  contact,  and  conseauently 
.he  instantaneous  vaporization,  of  the  sulphurous  acid,  which  during  its  evaponzatioo, 
robs  the  water  of  its  heat  and  reduces  it  to  the  state  of  ice. 

STEARIC  ACID,  improperly  called  Stearine  {Talgsaure,  Germ.),  is  the  solid  con- 
stituent of  fatty  substances,  as  of  tallow  and  olive  oil,  converted  into  a  crystalline  mass 
by  saponification  with  alkaline  matter,  and  abstraction  of  the  alkali  by  an  acid.  By  this 
process,  fats  are  convertible  into  three  acids,  called  Stearic,  Margaric,  and  Oleic ;  the 
first  two  being  solid,  and  the  last  liquid.  The  stearine,  of  which  factitious  wax  candles 
are  made,  consists  of  the  stearic  and  margaric  acids  combined.  These  can  be  separated 
from  each  other  only  by  the  agency  of  alcohol,  which  holds  the  margaric  acid  in 
solution  after  it  has  deposited  the  stearic  in  crystals.  Pure  stearic  acid  is  prepared, 
according  to  its  discoverer,  Chevreul,  in  the  following  way : — Make  a  soap,  by  boiling 
a  solution  of  potash  and  mutton-suet  in  the  proper  equivalent  proportions  (see  Soap); 
dissolve  one  part  of  that  soap  in  6  parts  of  hot  water,  then  add  to  the  solution  40 
or  50  parts  of  cold  water,  and  set  the  whole  into  a  place  whose  temperature  is  about 
52"  Fahrenheit.  A  substance  falls  to  the  bottom,  possessed  of  pearly  lustre,  consisting 
of  the  bi-stearate  and  bi-margarate  of  potash ;  which  is  to  be  drained  and  washed  upon 
a  filter.  The  filtered  liquor  is  to  be  evaporated,  and  mixed  with  the  small  quantity  of 
acid  necessary  to  saturate  the  alkali  left  free  by  the  precipitation  of  the  above  bi-salts. 
On  adding  water  to  it  afterwards,  the  liquor  aflTords  a  fresh  quantity  of  bi-stearate  and 
bi-margarate.  By  repeating  this  operation  with  precaution,  we  finally  arrive  at  a  point 
when  the  solution  contains  no  more  of  these  solid  acids,  but  only  the  oleic.  The  pre- 
cipitated bi-salts  are  to  be  washed  and  dissolved  in  hot  alcohol,  of  specific  gravity  0*820, 
of  which  they  require  about  24  times  their  weight.  During  the  cooling  of  the  solution, 
the  bi-stearate  falls  down,  while  the  greater  part  of  the  bi-margarate,  and  the  remainder 
of  the  oleate,  remain  dissolved.  By  once  more  dissolving  in  alcohol,  and  cr^^stallizing, 
the  bi-stearate  will  be  obtained  alone ;  as  may  be  proved  by  decomposing  a  little  of  it 
in  water  at  a  boiling  heat,  with  muriatic  acid,  letting  it  cool,  washing  the  stearic  acid 
obtained,  and  exposing  it  to  heat,  when,  if  pure,  it  will  not  fuse  in  water  under  the  158th 
degree  of  Fahrenheit's  scale.  If  it  melts  at  a  lower  heat,  it  contains  more  or  less  mar- 
garic acid.  The  purified  bi-stearate  being  decomposed  by  boiling  in  water  along  with  any 
apid,  as  the  muriatic,  the  disengaged  stearic  acid  is  to  be  washed  by  melting  in  water,  then 
cooled  and  dried. 

Stearic  acid,  prepared  by  the  above  process,  contains  combined  water,  from  which  it 
cannot  be  freed.  It  is  insipid  and  inodorous.  After  being  melted  by  heat,  it  solidifies 
at  the  temperature  of  158°  Fahrenheit,  and  affects  the  form  of  white  brilliant  needles 
grouped  together.  It  is  insoluble  in  water,  but  dissolves  in  all  proportions  in  boiling 
anhydrous  alcohol,  and  on  cooling  to  122°,  crystallizes  therefrom,  in  pearly  plates; 
but  if  the  concentrated  solution  be  quickly  cooled  to  112°,  it  forms  a  crystalline  mass. 
A  dilute  solution  affords  the  acid  crystallized  in  large  white  brilliant  scales.  It  di». 
solves  in  its  own  weight  of  boiling  ether  of  0'727,  and  crystallizes  on  cooling  in  beau- 
tiful scales,  of  changing  colors.  It  distils  over  in  vacuo  without  alteration  ;  but  if  the 
retort  contains  a  little  atmospheric  air,  a  small  portion  of  the  acid  is  decomposed  during 
the  distillation;  while  the  greater  part  passes  over  unchanged,  but  slightly  tinged 
brown,  and  mixed  with  traces  of  empyreumalic  oil.  When  heated  in  the  open  air,  and 
kindled,  stearic  acid  burns  like  wax.  It  contains  3*4  per  cent,  of  water,  from  which 
it  may  be  freed  by  combining  it  with  oxyde  of  lead.  When  this  anhydrous  acid  is  sub- 
jected to  ultimate  analysis,  it  is  found  to  consist  of — 80  of  carbon,  12-5  hydrogen, 
and  7-5  oxygen,  in  100  parts.  Stearic  acid  displaces,  at  a  boiling  heat  in  water, 
carbonic  acid  from  its  combinations  with  the  bases ;  but  in  operating  upon  an  alka- 
line carbonate,  a  portion  of  the  stearic  acid  is  dissolved  in  the  liquor  before  the 
carbonic  acid  is  expelled.  This  decomposition  is  founded  upon  the  principle,  that 
the  stearic  acid  transforms  the  salt  into  a  bicarbonate,  which  is  decomposed  by  the 
ebullition. 

Stearic  acid  put  into  a  strong  watery  infusion  of  litmus,  has  no  action  upon  it  in  the 
cold  ;  but  when  hot,  the  acid  combines  with  the  alkali  of  the  litmus,  and  changes  its 
blue  color  to  red ;  so  that  it  has  sufficient  energy  to  abstract  from  the  concentrated 
tincture  all  the  alkali  required  for  its  neutralization.  If  we  dissolve  bi-stearate  of  potash 
in  weak  alcohol,  and  pour  litmus  water,  drop  by  drop,  into  the  solution,  this  will  become 
red,  because  the  litmus  will  give  up  its  alkali  to  a  portion  of  the  bi-stearate,  and  will  con- 
vert it  into  neutral  stearate.  If  we  now  add  cold  water,  the  reddened  mixture  will  re- 
sume its  blue  tint,  and  will  deposite  bi-stearate  of  potash  in  small  spangles.  In  order 
that  the  alcoholic  solution  of  th^  bi-stearate  may  redden  the  litmus,  the  alcohol  should 
not  be  very  strong. 


m 


STEARINE  COLD  PRESS. 


721 


From  the  composition  of  stearate  of  potash,  the  atomic  weight  of  the  acid  appears  to  be 
106-6  ;  hydrogen  being  1 ;  for  18 :  48  X  2  ::  100 :  533-3  =  5  atoms  of  acid. 

From  the  stearate  of  soda,  it  appears  to  be  104 ;  and  from  that  of  lime,  102.  The 
stearate  of  lead,  by  Chevreul,  gives  109  for  the  atomic  weight  of  the  acid. 

The  margaric  and  oleic  acids  seem  to  have  the  same  neutralizing  power,  and  the  same 
atomic  weight. 

The  preceding  numbers  will  serve  to  regulate  the  manufacture  of  aCearic  acid  for  the 
purpose  of  makin?  candles.     Potash  and  soda  were  first  prescribed  for  saponifying  fat,  as 
may  be  seen  in  M.  Gay  Lussac's  patent,  under  the  article  Candle  ;  and  were  it  not  for 
the  cost  of  these  articles,  they  are  undoubtedly  preferable  to  all  others  in  a  chemical  point 
of  view.     Of  late  years  lime  has  been  had  recourse  to,  with  perfect  success,  and  has  be- 
come subservient  to  a  great  improvement  in  candle-making.    The  stearine  block  now 
made  by  many  London  houses,  though  containing  not  more  than  2  or  3  per  cent,  of  wax, 
is  hardly  to  be  distinguished  from  the  purified  produce  of  the  bee.     The  first  process  is 
to  bod  the  fat  with  quicklime  and  water  in  a  large  tub,  by  means  of  perforated   steam 
pipes  distributed  over  its  bottom.     From  the  above  statements  we  see  that  about  11  parts 
of  dry  lime  are  fully  equivalent  to  100  of  stearine  and  oleine  mixed  :  but  as  the  lime  is  in 
the  state  of  hydrate,  14  parts  of  it  will  be  required  when  it  is  perfectly  pure;  in  the  ordi- 
nary state,  however,  as  made  from  average  good  limestone,  16  parts  may  be  allowed. 
After  a  vigorous  ebullition  of  3  or  4  hours,  the  combination  is  pretty  complete.    The 
stearate  being  allowed  to  cool  to  such  a  degree  as  to  allow  of  its  being  handled,  becomes 
a  coricrete  mass,  which  must  be  dug  out  with  a  spade,  and  transferred  into  a  contiguous 
tub,  m  order  to  be  decomposed  with  the  equivalent  quantity  of  sulphuric  acid  diluted 
With  water,  and  also  heated  with  steam.     Four  parts  of  concentrated  acid  will  be  sufll- 
cient  to  neutralize  three  parts  of  slaked  lime.     The  saponified  fat  now  liberated  from  the 
hme,  which  is  thrown  down  to  the  bottom  of  the  tub  in  the  state  of  sulphate,  is  skimmed 
off  the  surface  of  the  watery  menstruum  into  a  third  contiguous  tub,  where  it  is  washed 
with  water  and  steam. 

The  washed  mixture  of  stearic,  margaric,  and  oleic  acids,  is  next  cooled  in  tin  pans ; 
then  shaved  by  large  knives,  fixed  on  the  face  of  a  fly-wheel,  called  a  tallow  cutter,  pre- 
paratory to  its  being  subjected  in  canvass  or  caya  bags  to  the  action  of  a  powerful  hydrau- 
lic press.    Here  a  large  portion  of  the  oleic  acid  is  expelled,  carrying  with  it  a  little  of 
the  margaric.    The  pressed  cakes  are  now  subjected  to  the  action  of  water  and  steam 
once  more,  after  which  the  supernatant  stearic  acid  is  run  off,  and  cooled  in  moulds.     The 
cakes  are  then  ground  by  a  rotatory  rasping-machine  to  a  sort  of  mealy  powder,  which  is 
put  into  canvass  bags,  and  subjected  to  the  joint  action  of  steam  and  pressure  in  a  hori- 
zontal  hydraulic  press  of  a  peculiar  construction,  somewhat  similar  to  that  which  has 
been  long  used  in  London  for  pressing  spermaceti.    The  cakes  of  stearic  acid  thus  freed 
completely  from  the  margaric  and  oleic  acids,  are  subjected  to  a  final  cleansing  in  a  tub 
with  steam,  and  then  melted  into  hemispherical  masses  called  blocks.    When  these  blocks 
are  broken,  they  display  a  highly  crystalline  texture,  which  would  render  them  unfit  for 
making  candles.     This  texture  is  therefore  broken  down  or  comminuted  by  fusin<'  the 
stearme  in  a  plated  copper  pan,  along  with  one  thousandth  part  of  pulverized  arsenious 
*"oJ.^  » i^rTJii^^^'^  '^  ^^^^^'  *°  ^^  '^^^^  '"^o  candles  in  appropriate  moulds.     See  Candlk. 
SrEARINE    COLD   PRESS.      The  cold  hydraulic  press,  as  mounted  by  Messrs. 
Maudslay  and  Fm^,  for  squeezing  out  the  oleic  acid  from  saponified  fat,  or  the  oleine 


Scale  Z-1QtKs  of  an  inch  to  the  foot. 


1354 


-722 


STEARINE  COLD  PRESS. 


»l 


1355 


Uuuuuiuy 


frwn  4x>coa-nut  lard,  is  represented  in  plan  in  fig.  1854. ;  in  side  viexr  of  pump  in  fi^. 
1355. ;  and  in  elevation, /^r.  1356. ;  where  the  same  letters  refer  to  like  objects. 

A,  L,  are  two  hydraulic  presses  ;  b,  the  frame  ;  c,  the  cylinder  ;  d,  the  piston  or  ram ; 
K,  the  follower  ;  f,  the  recess  in  the  bottom  to  receive  the  oil ;  g,  twilled  woollen  bags ; 
with  the  material  to  be  pressed,  having  a  thin  plate  of  wrought  iron  between  each ;  h, 
apertures  for  the  discharge  of  the  oil ;  i,  cistern  in  which  the  pumps  are  fixed  ;  k,  fram- 
ing for  machinery  to  work  in;  l,  two  pumps,  large  and  small,  to  inject  the  water 

into  the  cylinders ;  m,  a  frame  con- 
taining three  double  branches;  n, 
three  branches,  each  having  two 
stops  or  plugs,  by  which  the  ac- 
tion of  one  of  the  pumps  may  be 
intercepted  from,  or  communicated 
to,  one  or  both  of  the  presses  ;  the 
large  pump  is  worked  at  the  be- 
ginning of  the  operation,  and  the 
small  one  towards  the  end;  by 
these  branches,  one  or  both  presses 
may  be  discharged  when  the  opera- 
tion is  finished  ;  o,  two  pipes  from 
the  pumps  to  the  branches  ;  p,  pipe 
to  return  the  water  from  the  cyhn- 
ders  to  the  cisterns ;  q,  pipes  lead- 
ing from  the  pumps  through  the 
branches  to  the  cylinders;  e,  coni- 
cal drum,  fixed  upon  the  main  shaft 
]  Y,  driven  by  the  steam-engine  of  the 
factory  ;  s,  a  like  conic^  drum  to 
work  the  pumps ;  t,  a  narrow  leather  strap  to  communicate  the  motion  from  r  to  s ; 
u,  a  long  screw  bearing  a  nut,  which  works  along  the  whole  length  of  the  drum  ;  v,  the 
fork  or  guide  for  moving  the  strap  t  ;  w,  w,  two  hanging  bearings  to  carry  the  drum  s; 
X,  a  pulley  on  the  spindle  of  the  drum  s ;  y,  the  main  shaft ;  z,  fly-wheel  with  groove 
on  the  edge,  driven  by  the  pulley  x ;  on  the  axis  of  s,  is  a  double  crank,  which  works  the 
two  pumps  L.  a,  is  a  pulley  on  the  end  of  the  long  screw  u ;  an  endless  cord  passes 
twice  round  this  pulley,  and  under  a  pulley  fixed  in  the  weight  h  ;  by  layiiig  hold  of 
both  sides  of  this  cord,  and  raising  or  lowering  it,  the  forked  guide  v,  and  the  lea- 
ther strap  T,  are  moved  backwards  or  forwards,  by  means  of  the  nut  fixed  in  the 
guide,  80  as  to  accelerate  or  retard  at  pleasure  the  speed  of  the  working  of  the 
pumps ;  c,  is  a  piece  of  iron,  with  a  long  slit,  in  which  a  pin,  attached  to  Uie  fork  v 
travels,  to  keep  it  in  the  vertical  position. 


STEATITE.  723 

STEARINE.    Fig  1367.  is  a  view  of  both  the  exterior  and  interior  of  the  saponi- 


iii\\v 


1^7 


u 


^ng  tun  of  a  stearine  factory;  where  the  constituents  of  the  tallow  are  combined  with 
juicklime,  by  the  intervention  of  water  and  steam:  a,  is  the  upriSt  shSK  i^n 
nimed  by  tiie  bevel  wheel  above,  in  gear  with  anoth<i  bevel  whef fon  ?he  movTn.' 

lt.pC/h'^Th" '?  "^^'l^^l'  .Thi««P"^htshaftbear8severalarmsd,furnJ8hed^th 
Urge  teeth.  The  tun  is  bound  with  strong  hoops  of  iron,  and  its  contents  are  helted  bv 
means  of  a  spiral  tube  laid  on  the  bottom,  perforated  with  numerons  hn^H  -„i  ^ 
nected  by  a  pipe  with  a  high-pressure  steam-boil^.  »»"°»erous  holes,  and  con- 

Fxg.  1358,  represents  a  longitudinal  section  of  the  horizontal  hydraulic  Dre«  for 
deprivmg  stearic  acid,  as  also  spermaceti,  of  all  theu-  fluid  oily  unpWSS     a't  the 


qrlmder  of  the  press ;  6,  the  ram  or  piston :  t,  t,  t,  t,  hair  and  flannel  baw  enclosing 
the  impure  cakes  to  be  exposed  to  pressure;  rf,  rf,  rf/rf,  iron  plates  prev?/,LlyhS 
^d  placed  between  every  two  cakes  to  facilitate  the  discharge  of  theHny  matter  ee 
so  Id  iron  end  of  the  press,  made  to  resist  great  pressure;  it  is  strongly  boUed  to  t^l 
cyhnder  a,  so  as  to  resist  the  force  of  the  ram;  V  g,  iron  rods  for  W^inn  ?  ?  ft® 
rami,  into  its  place  after  the  pressure  is  over,  by^mfansTf  ot\e7we^^g^^^^ 

ii^^^Z^l'tZl'^^i^'lTt^^^^  -  a  -ineml  of 

with  dendriUc  delineaUons,  and  occurs  maLsTve    as  alf„?n^^'^^'^'  '°^^'''.  ??^"  "^^rked 

line  forms;  it  has  a  duller  fatly  lusfr^  a  coSsfsXZ^^^^ 

edges;  a  shining  streak;  it  writes  feebly ;  is  soHnVeScL  wi  K^J^-r^  translucent 

what  tough;  does  not  adhere  to  the  tongue;  frels  very ?rety    in^.^W^^^  m"'"" 

pipe ;  specific  gravity  from  2-6  to  2-8.     It  consists  of- Jn.f  4^  infusible  before  the  blow- 

2;  iron  7.3;  manganese,  1-5;  chrome,  2;  wiralcfo?lit^T:S^ 

in  .mall  contemporaneous  veins  that  traverse  serpentine  in  ^W  directiLs  as  at  Ky^ 


724 


STEEL. 


•  > 


in  Shetland,  in  the  limestone  of  Icolmkiln,  in  the  serpentine  of  CornwaU,  in  Anglesey  ji 

.am      It  makes  the  buiscuit  semi-transparent,  but  rather  brjtle,  and  ant  to  crack  with 
slight  changes  of  heat.     It  is  employed  for  polishing  serpentine,  marble^gVisers  alalas^ 
ter,  and  mirror  glass ;  as  the  basis  of  cosmetic  powders ;  as  an  inoredient  [rant  attrition 
pastes;  it  is  dusted  in  powder  upon  the  inside  of  boots, 'to  mak^ttfeet  gHde  e^^^^^^^^^^^^ 
them;  when  rubbed  upon  grease-spots  in  silk  and  wooUen  clothes,  it  renfoves  the  stains 
by  absorption ;  it  enters  into  the  composition  of  certain  crayons,  andT  used  Use^  for 
making  traces  upon  glass,  silk,  &c.     The  spotted  steatite,  cut  into'cameos  and  ^alc  ned 
assumes  an  onyx  aspect.     Soft  steatite  forms  exceUent  stoppers  for  the  chemical  apDam 
ST'i?rr.^i'''^^'"#  «^  «"Wiming  corrosive  vapors.    Lamellar  steatite  is  Talc     ^"^ 
bTEEL  (^cier,  Fr. ;  Stahl,  Germ.),  as  a  carburet  of  iron,  has  already  been  considered 

"ch^ical  rS:lts.'  '''"  '"''  "  ''"  "^^^^^  "^"  '"^'''^^''^  ''  '''  manXrre  ani 
1.  Steel  of  cemmtation,  bar  or  blistered  steel.-With  the  exception  of  the  Ulverstone 
charcoal  iron,  no  bars  are  manufactured  in  Great  Britain  capable  of  conversion  inti  steel 
at  all  approaching  m  quality  to  that  made  from  the  Madras,  Swedish,  and  Russian  irons 
so  largely  imported  for  that  purpose.  The  first  rank  is  assigned  to  the  SwXh  Tron 
W^of  Z  m''"^^  f"'^°'V"?  '^'  ^'''''  ^  (^^"^^^  ^«"^d  hoopl)  ;  which  fetches  he  igS 
Sp  nriL  T>?/-  r  T'  J^u^- '^''"'"*  ^""^^''^  ^^^^'^^^'^  "^^^  ^e  had  for  one  fifth  of 
mZr  ;  A-  ?i*'^'  ^"^^^''^  ''^"Z  ^'^  '^^'^  ^*  ^  "^"<=^  l«^er  rate,  though  said  to  be 
manufactured  m  the  same  way ;  and  therefore  the  superiority  of  the  Dannemora  iron  must 
be  owing  to  some  peculiarity  m  the  ore  from  which  it  is  smelted.  The  steel  recentlv 
Som  tie  ""'  '''''■"''''  '^  '^'''^^^'  ^''"^  ''''  «^^^^'«  Madras  iron,  rivals^^^^^^^^ 
The  Sheffield  furnace  for  making  bar  or  blistered  steel,  called  the  furnace  of  cementa- 
Uon,  IS  represented  m  ^g.  1359,  in  a  cross  section,  and  in  Jig.  laeo,  in  a  ground  pkS. 

1J^59   .  1360 


STEEL. 


725 


Of  chimnev  from  ?ft  *„  Kn^Tu°u  t  °. ,?"™«e  »«  b"il'  under  a  conical  hood 
amoke       ^'  ^^  *°  ^^  ^'"  ''«'••  f"'  ^^^  the  draught,  and  carrying  off  the 

The  two  chests  are  built  of  fire-stone  grit.    Thev  are  8  1ft  a,  •„=„  i  k  <•   .  i  j 

from  26  to  36  inches  in  wi<1th  ..n^  j.^fi,  \\.    V  '  ',     •  *"  *'^^°  '*  '^et  long,  and 

uniform  will  the  quali?  rf  tte  8?eel  l£  'a  *  'Tk  '^i^Y'  ^'^  "«•  "'«""'" 
incompaUble  withlqSlUy  of'th  tm'^ntint  ^^'"T^^^^,  ^fs""  "'  V""^'  T 
thick.  The  space  teween  them  is  at  lo»f»  -  r?  •  j  ""1  '""'"  "^  *  ^^"^  '""=''«' 
directly  upon  the  sole  of  the  ZJLf  w  "  ?l'  '"<'*■  ^'7  «'«»'W  "«''"•  "-es' 
upon  gy  tL  arme,^  weU  L  [^^^3  a^n"^"''  ^^^  ^Y"  '""'>'°  f'^^'?  P'*?"! 
bropenings  in  the  Mcror^non  lh»  fn^      jP"    A*  •''K'*^  "'  •"'»'  »  regula'ted 


PoillKiv  »h?c  'u      *''*'*'""^  ?^.i^^  ""^P^"*"*  ^^'^'^^^  »"^  <^^ay,  which  it  penerally  contains. 
Possibly  the  salt  serves  to  vitrify  the  particles  of  silica  in  the  charcoa"],  and  thus  to  pre- 

df^ni^r  Y^    ""^  *"JSu  ^r^'"**^''"  ^'^^  ^^^  ^t^^'-    As  for  the  ashes,  it  is  difficult  to 
discover  their  use.    The  best  steel  may  be  made  without  their  presence.     The  bottom  of 

lill^"^-^         "  T^""^  ^'"^^^  t^«  ^"<^*^^«  ^^t'^e  PO^vder  of  cementation,  the  bars  are  laid 
^ic^r"    V"^"  their  narrow  edge,  the  side  bar  being  one  inch  from  the  trough,  and  the 

Zl  Zl  IZ  '"'  ^'f.'"  'u'';  ?"^'^'  ^^  ^"  ^"^^  ^P*^^-     A^«^e  this  first  layer  of  iron 
bars,  fully  half  an  inch  depth  of  the  powder  is  spread,  then  a  new  series  of  bars  is  strali- 

fin^^  w;t1?  n?^  ^  ?'*""\''  ^"^'i  '^'^^''^  '^'^  ^"'^^^  °^  the  top.     This  space  is  partially 

filled  with  old  cement  powder,  and  is  covered  with  refractory  damp  sand.     Sometimes 

nL      t\  't        l.*^^^^  '"'^^'^^  "^"h  the  old  cement,  and  then  closely  covered  with  fire- 
uies.     Ihe  bars  should  never  be  allowed  to  touch  each  other,  or  the  trough.    The  A-e 

?or?  w^'^'    ""/  "^^i  ^'^"^  \;^°  *^  ^°"'  ^^^^^  *tH  it  acquires  the  temperature  ^f 
100«Wedgewood;  which  must  be  steadily  maintained  during  the  four,  six,  eight    oi 
ten  days  requisite  for  the  cementation ;  a  period  dependant  on  the  size  of  the  furnace, 
and  which  is  determined  by  the  examination  of  the  proof  pieces,  taken  out  from  time  to 

In  the  front  or  remote  end  of  the  furnace,./Zg.  1054,  a  door  is  left  in  the  outer  buildin.^, 
corresponding  to  a  similar  one  in  the  end  of  the  interior  vault,  through  which  the  work! 
man  enters  for  charging  the  furnace  with  charcoal  and  iron  bars,  as  also  for  taking  out 
the  steel  after  the  conversion.  Small  openings  are  likewise  .-sde  in  the  ends  of  the 
chests,  through  which  the  extremities  of  a  few  bars  are  left  projecting,  so  that  thev  raav 
be  pulled  out  and  examined,  through  small  doors  opposite  to  them  in  the  exterior  wail/. 
These  tap  holes,  as  they  are  called,  ohould  be  placed  near  the  centre  of  the  end  stones  of 
the  chests,  that  the  bars  may  indicate  the  average  state  of  the  process.  The  joiain'-s  of 
the  fire-stones  are  secured  with  a  finely  ground  Stourbridge  clay  "* 

The  interval  between  the  two  chests  (in  furnaces  containing 'two,  for  many  have  only 
one)  being  covered  with  an  iron  platform,  the  workman  stands  on  it,  and  sifts  a  layer  of 
charcoal  on  the  bottom  of  the  chests  evenly,  about  half  an  inch  thick;  he  then  lays  a  row 
of  bars,  cut  to  the  proper  length,  over  the  charcoal,  about  an  inch  from  each  other-  he 
next  sifts  on  a  second  stratum  of  charcoal-dust,  which,  as  it  must  serve  for  the  bars  abive, 
fi?i^     SK-^       '•  '"u^^'^r  T  '"''^  ^^'f  5  thus,  he  continues  to  stratify,  till  the  chest  be 
f  f^    J!^.""  ^"^^  '"^^^'  ""^  ^^^  ^""P '  *"^  ^^  '^"^^'■^  the  whole  with  the  earthy  detritus  found 
at  the  bottom  of  grindstone  troughs,  or  any  convenient  fire-loam.     It  is  obvious  that  the 
second  series  of  bars  should  correspond  vertically  with  the  interstices  between  the  first 
senes,  and  so  m  succession.     The  trial-rods  are  left  longer  than  the  others,  and  their 
projecting  ends  are  incrusted  with  fire-clay,  or  imbedded  in  sand.    The  iron  platform 
being  removed,  and  all  the  openmgs  into  the  vault  closed,  the  fire  is  lighted,  and  very 
gradually  increased   to  avoid  every  risk  of  cracking  the  grit-stone  bv  too  sudden  a  chan4 
ol  temperature;  and  the  ignition  being  finally  raised  to  about  JOO^'Wedgewood,  but  not 
higher,  for  fear  of  melting  the  metal,  must  be  maintained  at  a  uniform  pitch,  till  the  iron 
have  absorbed  the  desired  quantity  of  carbon,  and  have  been  converted  as  highly  as  the 
manufacturer  intends  for  his  peculiar  object.     From  six  to  eight  days  may  be  reckoned  a 
sufficient  period  for  the  production  of  steel  of  moderate  hardness,  and  fit  for  tUting  into 
I^A  T]\  ^  f'^'l''^}>  ^- i^^«  -»d  «P"n?^.  takes  a  shorter  period     and  a  ha  Se? 

charcoal  B^ItT^  '^r '''  "'^^  ^"  "'^"^"!  ^'■""'  ^'"  "^^^  ^""^^^  ^^P^^^^e  to  the  ignuS 
charcoal  But,  for  a  few  purposes,  such  as  the  bits  for  boring  cast  iron,  the  bar«;  arc 
exposed  o  two  or  three  successive  processes  of  cementation,  and  are  hence  said  to  b^ 
twice  or  thrice  converted  into  steels.  The  higher  the  heat  of  the  furnace,  the  quicker  i^ 
Uie  process  of  conversion.  '        quicucr  is 

The  furnaoe  being  suffered  to  cool,  the  workman  enters  it  again,  and  hands  out  the  steel 
bars,  which  being  covered  with  blisters,  from  the  formation  and  bursting  of  vesicles  on 
the  surface  filled  with  gaseous  carbon,  is  called  bmered  steel.  This  steel  t  veA  irreeu^ 
lar  m  its  interior  texture  has  a  white  color,  like  frosted  silver,  and  di 'plays  cn'sta^fnc 
angles  and  facettes  which  are  larger  the  further  the  cementation  has  been  urgS  or  he 

fhTsurflc:  ofThelT"^"-    ^'^  ^^^^^'^  ^^^^^^^  ^^  ^'^^^^  -^"^r  than  fhte'nlL^ 
In  such  a  furnace  as  the  above,  twelve  tons  of  bar  iron  may  be  converted  at  a  charge 
But  other  furnaces  are  constructed  with  one  chest,  which  receives  six  or  eight  tons  af  a 
time  ;  the  small  furnaces,  however,  consume  more  fuel  in  proportion  than  the  arger 

The  absorption  and  action  of  the  carbonaceous  matter,  to  the  amount  of  about  a  half 
per  cent.,  occasions  fissures  and  cavities  in  the  substance  of  the  blistered  bTs  whrch 
render  the  steel  unfit  for  any  useful  purpose  in  tool-making,  till  it  be  cSsed  a^Ire^^^^ 
foe'lRON!^'''"'  ""^  ""  "'^' ""''''  ^  P«^^r^«l  h^'^nier  driven  by  macMnerJ. 

*  For  minute  details  of  the  parts,  aee  the  excellent  article  T.ltino-h^mm.r.  in  Ree,U  Cyclop^i^ 


726 


STEEL. 


STEEL. 


727 


I 


i 


The  heads  of  the  iflt-hammers  for  steel  weigh  from  one  and  a  half  to  two  hundred 
pounds.  Those  in  the  neighborhood  of  Sheffield  are  much  simpler  than  the  one  referred 
to  in  the  note.  They  are  worked  by  a  small  water-wheel,  on  whose  axis  is  another 
wheel,  bearing  a  great  number  of  cams  or  wipers  on  its  circumference,  which  strike  the 
tail  of  the  hammer  in  rapid  succession,  raise  its  head,  and  then  let  it  fall  smartly  on  the 
hot  metal  rod,  dexterously  presented  on  its  several  parts  to  the  anvil  beneath  it,  by  the 
workman.  The  machinery  is  adapted  to  produce  from  300  to  400  blows  per  minute ; 
which  on  this  plan  requires  an  undue  and  wasteful  velocity  of  the  float-boards.  Were 
an  intermediate  toothed  wheel  substituted  between  the  water-wheel  and  the  wiper- 
wheel,  so  that  while  the  former  made  one  turn,  the  latter  might  make  three,  a  much 
smaller  force  of  water  would  do  the  work.  The  anvils  of  the  tilt-hammer  are  placed 
nearly  on  a  level  with  the  floor  of  the  mill-house  ;  and  the  workman  sits  in  a  fosse,  dug 
on  purpose,  in  a  direction  perpendicular  to  the  line  of  the  helve,  on  a  board  suspended 
from  the  roof  of  the  building  by  a  couple  of  iron  rods.  On  this  swinging  seat,  he  can 
advance  or  retire  with  the  least  impulse  of  his  feet,  pushing  forward  the  steel  bar,  or 
drawing  it  back  with  equal  rapidity  and  convenience. 

At  a  small  distance  from  each  tilt,  stands  the  forge-hearth,  for  heating  the  steel.  The 
bellows  for  blowing  the  fire  are  placed  above-head,  and  are  worked  by  a  small  crank 
fixed  on  the  end  of  the  axis  of  the  wheel,  the  air  being  conveyed  by  a  copper  pipe  down 
to  the  nozzle.  Each  workman  at  the  tilt  has  two  boys  in  attendance,  to  serve  him  with 
hot  rods,  and  to  take  them  away  after  they  are  hammered.  In  small  rods,  the  bright 
ignition  originally  given  at  the  forge  soon  declines  to  darkness;  but  the  rapid  impulsions 
of  the  tilt  revive  the  redness  again  in  all  the  points  near  the  hammer ;  so  that  the  rod, 
skilfully  handled  by  the  workman,  progressively  ignites  where  it  advances  to  the  strokes. 
Personal  inspection  alone  can  communicate  an  adequate  idea  of  the  precision  and  cele- 
rity with  which  a  rude  steel  rod  is  stretched  and  fashioned  into  an  even,  smooth,  and 
sharp-edged  prism,  under  the  operation  of  the  tilt-hammer.  The  heat  may  be  clearly 
referred  to  the  prodigious  friction  among  the  particles  of  so  cohesive  a  metal,  when  they 
are  made  to  slide  so  rapidly  over  each  other  in  every  direction  during  the  elongation  and 
squaring  of  the  rod. 

2.  Shear  steel  derives  its  name  from  the  accidental  circumstance  of  the  shears  for 
dressing  woollen  cloth  being  usually  forged  from  it.  It  is  made  by  binding  into  a  bundle, 
with  a  slender  steel  rod,  four  parallel  bars  of  blistered  steel,  previously  broken  into 
lengths  of  about  18  inches,  including  a  fifth  of  double  length,  whose  projecting  end  may 
serve  as  a  handle.  This  fagot,  as  it  is  called,  is  then  heated  in  the  forge-hearth  to  a 
good  welding-heat,  being  sprinkled  over  with  sand  to  form  a  protecting  film  of  iron  slag, 
carried  forthwith  to  the  tilt,  and  notched  down  on  both  sides  to  unite  all  the  bars  to- 
gether, and  close  up  every  internal  flaw  or  fissure.  The  mass  being  again  heated,  and 
the  binding  rings  knocked  ofiT  it,  is  drawn  out  into  a  uniform  rod  of  the  size  required. 
Manufacturers  of  cutlery  are  in  the  habit  of  purchasing  the  blistered  bars  at  the  con- 
version furnaces,  and  sending  them  to  tilt-mills  to  have  them  drawn  out  to  the  proper 
size,  which  is  done  at  regular  prices  to  the  trade ;  from  5  to  8  per  cent,  discount  being 
allowed  on  the  rude  bars  for  waste  in  the  tilting.  The  metal  is  rendered  so  compact  by 
the  welding  and  hammering,  as  to  become  susceptible  of  a  much  finer  polish  than  blis- 
tered steel  can  take ;  while  the  uniformity  of  its  body,  tenacity,  and  malleability  are  at 
the  same  time  much  increased ;  by  which  properties  it  becomes  well  adapted  for  making 
table  knives  and  powerful  springs,  such  as  those  of  gun-locks.  The  steel  is  also  softened 
down  by  this  process,  probably  from  the  expulsion  of  a  portion  of  its  carbon  during  the 
welding  and  subsequent  heats ;  and  if  these  be  frequently  or  awkwardly  applied,  it  may 
pass  back  into  common  iron. 

3.  Cast  steel  is  made  by  melting,  in  the  best  fire-clay  crucibles,  blistered  steel,  broken 
down  into  small  pieces  of  convenient  size  for  packing;  and  as  some  carbon  is  always 
dissipated  in  the  fusion,  a  somewhat  highly  converted  steel  is  used  for  this  purpose. 
The  furnace  is  a  square  prismatic  cavity,  lined  with  fire-bricks,  12  inches  in  each  side, 
and  24  deep,  with  a  flue  immediately  under  the  cover,  3|  inches  by  6,  for  conducting 
the  smoke  into  an  adjoining  chimney  of  considerable  height.  In  some  establishments 
a  dozen  such  furnaces  are  constructed  in  one  or  two  ranges,  their  tops  being  on  a  level 
with  the  floor  of  -the  laboratory,  as  in  brass-foundries,  for  enabling  the  workmen  more 
conveniently  to  inspect,  and  lift  out,  the  crucibles  with  tongs.  The  ash-pits  terminate 
in  a  subterraneous  passage,  which  supplies  the  grate  with  a  current  of  cool  air,  and 
serves  for  emptying  out  the  ashes.  The  crucible  stands,  of  course,  on  a  sole  piece  of 
baked  fire-clay;  and  its  mouth  is  closed  with  a  well-fitted  lid.  Sometimes  a  little 
bottle-glass,  or  blast-furnace  slag,  is  put  into  the  crucible,  above  the  steel  pieces,  to  form 
a  vitreous  coating,  that  may  thoroughly  exclude  the  air  from  oxidising  the  metal  The 
fuel  employed  in  the  cast-steel  furnace  is  a  dense  coke,  brilliant  and  sonorous,  broken 
into  pieces  about  the  size  of  an  egg,  one  good  charge  of  which  is  sufficient.  The 
tongs  are  furnished  at  the  fire  end  with  a  pair  of  concave  jaws,  for  embracing  the 


cttrvature  of  the  crucible,  and  lifting  it  out  whenever  the  fusion  is  complete.  The  lid 
is  then  lemoved,  the  slag  or  scoriae  cleared  away,  and  the  liquid  metal  poured  Into 
east-iron  octagonal  or  rectangular  moulds,  during  which  it  throws  out  brilliant  scintil- 
lations. 

Cast-steel  works  much  harder  under  the  hammer  than  shear  steel,  and  will  not,  in  its 
usual  state,  bear  much  more  than  a  cherrj-red  heat  without  becoming  brittle ;  nor  can 
it  beeur  the  fatigue  incident  to  the  welding  operation.  It  may,  however,  be  firmly  welded 
to  iron,  through  the  intervention  of  a  thin  film  of  vitreous  boracic  acid,  at  a  moderate  de- 
gree of  ignition.  Cast  steel,  indeed,  made  from  a  less  carbureted  bar  steel,  would  be  sus- 
ceptible of  welding  and  hammering  at  a  higher  temperature ;  but  it  would  require  a 
very  high  heat  for  its  preparation  in  the  crucible. 

Iron  may  be  very  elegantly  plated  with  cast  steel,  by  pouring  the  liquid  metal  from 
the  crucible  into  a  mould  containing  a  bar  of  iron  polished  on  one  face.  In  this  cir- 
cumstance the  adhesion  is  so  perfect  as  to  admit  of  the  two  metals  being  rolled  out  to- 
gether ;  and  in  this  way  the  chisels  of  planes  and  other  tools  may  be  made,  at  a  moderate 
rate  and  of  excellent  quality,  the  cutting-edge  being  formed  in  the  steel  side.  Such 
instruments  combine  the  toughness  of  iron  with  the  hardness  of  steel. 

For  correcting  the  too  high  carbonization  of  steel,  or  equalizing  the  too  highly  cott- 
verted  exterior  of  a  bar  with  the  softer  steel  of  the  interior,  the  metal  requires  merely 
to  be  imbedded,  at  a  cementing  heat,  in  oxyde  of  iron  or  manganese ;  the  oxygen  of  whi^ 
soon  abstracts  the  injurious  excess  of  carbon,  so  that  the  outer  layers  may  be  even  con- 
verted into  soft  iron,  while  the  axis  continues  steely ;  because  the  decarbonizing  advancei 
far  more  rapidly  than  the  carbonizing. 

Fig.  1361  represents  the  mould  for  making  crucibles  ior  the  cast-steel  works,  m  bc, 
is  a  solid  block  of  wood,  to  support  the  two-handled  outside  mould  n,  n.     This  being 

rammed  full  of  the  proper  clay  dough  or  compost  (see  Cbuci- 
ble),  the  inner  mould  is  to  be  then  pressed  vertically '  into  it, 
till  it  reaches  the  bottom  f,  being  directed  and  facilitated  in  its 
descent  by  the  point  k.  A  cord  passes  through  o,  by  which 
the  inner  mould  is  suspended  over  a  pulley,  and  gviided  in  its 
motions. 

When  a  plate  of  polished  steel  is  exposed  to  a  progressive 
heat,  it  takes  the  following  colors  in  succession :  1 ,  a  faint 
yellow ;  2,  a  pale  straw-color ;  3,  a  full  yellow ;  4,  a  brown 
yellow ;  5,  a  brown  with  purple  spots ;  6,  a  purple ;  7,  a  br^ht 
blue ;  8,  a  full  blue ;  9,  a  dark  blue,  verging  on  black  ;  after 
which  the  approach  to  ignition  supersedes  all  these  colors.  If 
the  steel  plate  has  been  previously  hardened  by  being  dipped 
in  cold  water  or  mercury  when  red-hot,  then  those  successive 
shades  indicate  or  correspond  to  successive  degrees  of  softening 
or  tempering.  Thus,  No.  1  suits  the  hard  temper  of  a  lancet,  which  requires  the  finest 
edgCf  but  little  strength  of  metal ;  No.  2  a  little  softer,  for  razors  and  surgeons'  ampu- 
tating instruments ;  No.  3,  somewhat  more  toughness,  for  penknives ;  No.  4,  for  cold 
chisels  and  shears  for  cutting  iron ;  No.  5,  for  axes  and  plane-irons ;  No.  6,  for  table  knives 
and  cloth  shears ;  No.  7,  for  swords  and  watch-springs  ;  No.  8,  for  small  fine  saws  and 
diggers ;  No.  9,  for  large  saws,  whose  teeth  need  to  be  set  with  pliers,  and  sharpened 
with  a  file.  After  ignition,  if  the  steel  be  very  slowly  cooled,  it  becomes  exceedingly 
soft,  and  fit  for  the  engraver's  purposes.  Hardened  steel  may  be  tempered  to  the  desired 
pitch,  by  plungin?  it  in  metallic  baths  heated  to  the  proper  thermometric  degree,  as  fol- 
lows :  for  No.  1,  430°  Fahr. ;  No.  2,  450° ;  No.  3,  470° ;  No.  4,  490°  ;  No.  5,  510°  j  No, 
6,  530° ;  No.  7,  550°;  No.  8,  560° ;  No.  9,  600°. 

Small  steel  tools  are  most  frequently  tempered,  after  hardening,  by  covering  their 
surface  with  a  thin  coat  of  tallow,  and  heating  them  in  the  flame  of  a  candle  till  the 
tallow  diffuses  a  faint  smoke,  and  then  thrusting  them  into  the  cold  tallow.  Rinman  long 
ago  defined  steel  to  be  any  kind  of  iron  which,  when  heated  to  redness,  and  then  plung^ 
m  cold  water,  becomes  harder.  But  several  kinds  of  cast  iron  are  susceptible  of  such 
hardening.  Every  malleable  and  flexible  iron,  however,  which  may  be  hardened  in  that 
way  is  a  steel.  Moreover,  steel  may  be  distinguished  from  pure  iron  by  its  giving  a 
dark-gray  spot  when  a  drop  of  dilute  nitric  acid  is  let  fall  on  its  surface,  while  iroi 
affords  a  green  one.  Exposed  to  the  air,  steel  rusts  less  rapidly  than  iron ;  and  the 
more  highly  carbureted,  the  more  slowly  does  it  rust,  and  the  blacker  is  the  spot  left  bt 
an  acid. 

After  hardening,  steel  seems  to  be  quite  a  diflTerent  body;  even  its  granular  texture 
becomes  coarser  or  finer,  according  to  the  degree  of  heat  to  which  it  was  raised ;  it  grows 
so  hard  as  to  scratch  gla$s,  and  resist  the  keenest  file,  while  it  turns  exceedingly  brittle. 


728 


STEEL. 


STEEL. 


720 


it 


i 


When  a  slowly  cooled  steel  rod  is  forged  and  filed,  it  becomes  capable  of  affording 
agreeable  and  harmonious  sounds  by  its  vibrations;  but  hard-tempered  steel  affordi 
only  dull  deafened  tones,  like  those  emitted  by  a  cracked  instrument 

The  good  quality  of  steel  is  shown  by  its  being  homogeneous ;  being  easily  worked  at 
the  forge;  by  its  hardening  and  tempering  well;  by  its  resisting  or  overcoming  forces; 
and  by  its  elasticity.    To  ascertain  the  first  point,  the  surface  should  be  ground  and  po- 
lished on  the  wheel ;  when  its  lustre  and  texture  will  appear.     The  second  test  require? 
a  skilful  workman  to  give  it  a  heat  suitable  to  its  nature  and  state  of  conversion.    Th« 
size  and  color  of  the  grain  are  best  shown  by  taking  a  bar  forged  into  a  razor  form ;  har. 
dening  and  tempering  it;  and  then  breaking  off  the  thin  edge  in  successive  bits  with 
hammer  and  anvil.    If  it  had  been  fully  ignited  only  at  the  end,  then,  after  the  harden 
ing,  it  will  display,  on  fracture,  a  succession  in  the  aspect  of  its  grains  from  that  extra 
mity  to  the  other;  as  they  are  whiter  and  larger  at  the  former  than  the  latter.    The  othei 
qualities  become  manifest  on  filing  the  steel;  using  it  as  a  chisel  for  cutting  iron;  d 
bending  it  under  a  heavy  weight. 

Much  interest  was  excited  a  few  years  back  by  the  experiments  of  Messrs.  Stodart  and 
Faraday  on  the  alloys  of  steel  with  silver,  platinum,  rhodium,  and  iridium.  Steel  refusei 
to  take  up  in  fusion  more  than  one  five-hundredth  part  of  silver;  but  with  this  minute 
quantity  of  alloy,  it  is  said  to  bear  a  harder  temper,  without  losing  its  tenacity.  When 
pure  iron  is  substituted  for  steel,  the  alloys  so  formed  are  much  less  subject  to  oxydation 
in  damp  air  than  before.  With  three  per  cent,  of  iridium  and  osmium,  an  alloy  was  ob- 
tained which  had  the  property  of  tempering  like  steel,  and  of  remaining  clean  and  bright, 
in  circumstances  when  simple  iron  became  covered  with  rusi.  »*Upon  the  whole,"  says 
the  editor  of  the  Quarterly  Journal  of  Science,  giving  a  report  of  these  experiments  in  his 
14th  volume,  p.  378,  "though  we  consider  these  researches  upon  the  alloys  of  steel  as 
very  interesting,  we  are  not  sanguine  as  to  their  important  influence  upon  the  improve- 
ment of  the  manufacture  of  cutlery,  and  suspect  that  a  bar  of  the  best  ordinary  steel,  s©. 
lected  with  precaution,  and  most  carefully  forged,  wrought,  and  tempered,  under  the  im- 
mediate impedion  of  the  master,  would  afford  cutting  instruments  as  perfect  and  excellent 
as  those  composed  of  wootz,  or  of  the  alloys." 

The  patent  plan  of  Mr.  William  Onions  of  making  cast  steel  seems  worthy  of  adop- 
tion. He  takes  two  parts  by  weight  of  haematite  ore  (such  as  that  of  Cumberland) 
reduced  to  a  state  of  coarse  powder,  and  puts  them  into  a  crucible ;  he  then  adds 
thereto  four  parts,  by  weight,  of  steel,  made  in  the  ordinary  way,  and  ninety-four 
parts  of  iron,  broken  into  small  pieces,  the  iron  used  being  that  made  from  Cumber- 
land ore,  or  other  iron  which  can  be  rendered  malleable  by  annealing ;  and  he  melts 
these  materials  together.  Instead  of  first  running  the  metal  into  ingots  or  bars,  and 
then  remelting  it,  he  casts  it  at  once  in  sand  moulds,  into  the  articles  required  to  be 
formed  of  cast  steel.  These  castings  are  rendered  malleable  by  the  process  of  anneal- 
ing, and  may  be  tempered  in  the  same  way  as  articles  made  of  ordinary  steel.  The 
annealing  process  employed  is  that  by  which  castings  of  iron,  made  from  Cumberland 
and  like  ores,  are  rendered  malleable.  The  articles  are  put  into  pots  or  boxes  with 
pulverized  Cumberland  ore,  or  other  matter  usually  employed  and  subjected  to  heat,  in 
an  annealing  oven,  for  a  time  dependent  upon  the  thickness  or  substance  of  the  articles, 
under  treatment.  The  articles  which  are  annealing  at  the  same  time  should  therefore 
be  as  nearly  as  possible  of  the  same  thickness;  and  the  heat  should  not  be  permitted  to 
increase  rapidly,  nor  to  attain  too  high  a  temperature.  The  time  required  for  the  an- 
nealing processes  will  be  ascertained  by  practice.  To  anneal  articles  about  an  inch 
square  (supposing  the  metal  to  be  in  bars  of  that  thickness)  they  should  be  kept  at  a 
red  heat  for  120  hours;  the  time  occupied  in  raising  them  to  that  heat  should  be  14 
hours,  and  after  they  have  been  kept  at  a  red  heat  for  10  hours,  they  should  be  allowed 
to  cool  down  very  gradually,  say  in  not  less  than  24  hours.  The  articles  thus  annealed 
may  be  turned  or  otherwise  reduced  to  the  desired  shape  by  the  ordinary  tools,  and 
may  be  tempered  in  the  same  manner  as  articles  made  of  common  cast  steel. 

The  patentee  does  not  confine  himself  to  the  above  details;  but  he  claims  the  mode 
of  manufacturing  cast-steel  by  melting  matters  together  apd  annealing  the  products, 
fts  above  described. 

Case-hardening  of  iron,  is  a  process  for  converting  a  thin  film  of  the  outer  surface 
into  steel,  while  the  interior  remains  as  before.  Fine  keys  are  generally  finished  in 
this  way.     See  Case-hardening. 

So  great  is  the  affinity  of  iron  for  carbon,  that,  in  certain  circumstances,  it  will  absorb 
it  from  carburetted  hydrogen,  or  coal-gas,  and  thus  become  converted  into  steel.  On  this 
principle,  Mr.  Mackintosh  of  Glasgow  obtained  a  patent  for  making  steel.  His  furnace 
consists  of  one  cylinder  of  bricks  built  concentrically  within  another.  The  bars  of  iron 
are  suspended  in  the  innermost,  from  the  top;  a  stream  of  purified  coal-gas  circulates 
freely  round  them,  entering  below  and  escaping  slowly  above,  while  the  bars  are  main- 
tained  in  a  state  of  bright  ignition  by  a  fire  burning  in  the  annular  space  between  the 


cylinders.    The  steel  so  produced  is  of  excellent  quality;  but  the  process  does  not  seem 
to  be  so  economical  as  the  ordinary  cementation  with  charcoal  powder. 

Damasking  of  steel,  is  the  art  of  giving  to  sabre  blades  a  variety  of  figures  in  the  stylf 
of  watering.     See  Damascus  Blades. 

Several  explanations  have  been  offered  of  the  change  in  the  constitution  of  steel, 
which  accompanies  the  tempering  operation ;  but  none  of  them  seems  quite  satisfactory. 
It  seems  to  be  probable  that  the  ultimate  molecules  are  thrown  by  the  sudden  cooling 
into  a  constrained  state,  so  that  their  poles  are  not  allowed  to  take  the  position  of  strong* 
est  attraction  and  greatest  proximity ;  and  hence  the  mass  becomes  hard,  brittle,  and 
somewhat  less  dense.  An  analogous  condition  may  be  justly  imputed  to  hastily  cooled 
glass,  which,  like  hardened  steel,  requires  to  be  annealed  by  a  sul^jequent  nicely  gradua- 
ted heat,  under  the  influence  of  which  the  particles  assume  the  position  of  repose,  and 
constitute  a  denser,  softer,  and  more  tenacious  body.  The  more  sudden  the  cooling  oi 
ignited  steel,  the  more  unnatural  and  constrained  will  be  the  distribution  of  its  particles, 
and  also  the  more  refractory,  an  effect  produced  by  plunging  it  into  cold  mercury.  This 
excess  of  hardness  is  removed  in  any  required  degree  by  judicious  annealing  or  temper* 
ing.  The  state  of  the  carbon  present  in  the  steel  may  also  be  modified  by  the  rate  oj 
refrigeration,  as  Mr.  Karslen  and  M.  Breant  conceive  happens  with  cast  iron  and  the 
damask  metal.  If  the  uniform  distribution  and  combination  of  the  carbon  through  the 
mass,  determine  the  peculiarity  of  white  cast  iron,  which  is  a  hard  and  brittle  substance 
and  if  its  transition  to  the  dark-gray  and  softer  cast  metal  be  effected  by  a  partial  form* 
tion  of  plumbago  during  slow  cooling,  why  may  not  something  similar  be  supposed  to  oc- 
cur with  steel,  an  analogous  compound  ? 

Mr.  Oldham,  printing  engineer  of  the  Bank  of  England,  who  has  had  great  experience 
in  the  treatment  of  steel  for  dies  and  mills,  says  that,  for  hardening  it,  the  fire  should 
never  be  heated  above  the  redness  of  sealing-wax,  and  kept  at  that  pitch  for  a  sufficient 
time.  On  taking  it  out,  he  hardens  it  by  plunging  it,  not  in  water,  but  in  olive  oil,  o. 
rather  naptha,  previously  heated  to  200*^  F.  It  is  kept  immersed  only  till  the  ebullition 
ceases,  then  instantly  transferred  into  cold  spring  water,  and  kept  there  till  quite  cold. 
By  this  treatment  the  tools  come  out  perfectly  clean,  and  as  hard  as  it  is  possible  to  make 
cast-steel,  while  they  are  perfectly  free  from  cracks,  flaws,  or  twist.  Large  tools  are 
readily  brought  down  in  temper  by  being  suspended  in  the  red-hot  muffle  till  they  show  a 
straw  color ;  but  for  small  tools,  he  prefers  plunging  them  in  the  oil  heated  to  400  de- 
grees ;  and  leaves  them  in  till  they  become  cold. 

Mr.  Oldham  softens  his  steel  dies  by  exposing  them  to  ignition  for  rtie  requisite  time, 
imbedded  in  a  nixture  of  chalk  and  charcoal. 

"The  common  mode  of  softening  steel,"  says  Mr.  Baynes,  "is  to  put  it  into  an  iron 
case,  surrounded  with  a  paste  made  of  lime,  cow's  gall,  and  a  little  nitre  and  water;  then 
to  expose  the  case  to  a  slow  fire,  which  is  gradually  increased  to  a  considerable  heat, 
and  afterwards  allowed  to  go  out,  when  the  steel  is  found  to  be  soft  and  ready  for  the 
engraver."* 

Steel,  manufacture  of. — Iron  in  the  composition  of  which  a  portion  of  the  silica  is  re- 
placed by  manganese,  will  while  being  smelted  rather  part  with  the  latter  than  the 
former.  From  this  it  follows,  that  at  the  moment  when  the  iron  is  on  the  point  of  pass- 
ing from  a  liquid  to  a  solid  state  it  will  retain  sufficient  silica  to  form  steel.  For  this 
reason,  during  the  whole  process  of  refining,  the  current  of  air  is  caused  to  act  rather  upon 
the  surface  of  the  metal  than  through  the  interior  of  the  fluid  mass,  in  order  to  avoid 
the  combustion  of  too  much  carbon  and  silica ;  from  which  it  follows  that  the  casting 
becomes  malleable  without  losing  a  suflScient  quantity  of  silica  to  constitute  iron,  prop» 
erly  so  called,  and  the  product  is  raw  or  blistered  steel.  The  casting  which  does  not 
contain  any  manganese  loses  by  the  effect  of  combustion  a  portion  of  silica  proportion- 
able to  the  quantity  of  carbon  burnt,  and  furnishes  iron  only  as  definite  product 

It  is  simply  to  the  mechanical  action  of  the  hammer,  that  the  distinctive  features  of 
bar  steel,  as  compared  with  that  of  cast  steel,  are  due.  In  order  to  effect  this  change, 
the  blistered  steel  is  broken  into  pieces  and  melted  down ;  they  are  afterward  tem- 
pered, again  broken  into  pieces,  and  welded  together  at  a  good  welding  heat  The 
steel  will  be  the  more  malleable,  and  possesses  more  tenacity  and  uniformity  of  texture, 
in  proportion  to  the  number  of  times  these  operations  are  repeated.  The  product  is 
called  "  wrought  or  shear  steel." 

Steel  of  cementation  and  cant  steel. — When  bar  iron  is  heated  to  a  white  heat,  or  even 
melted  in  close  vessels  containing  coal  or  carbonaceous  substances,  it  takes  up  a  certain 
quantity  of  carbon,  and  is  transformed  into  cast-steel  of  various  kinds. 

If  the  iron  contains  together  with  silica,  phosphorus  and  arsenic  in  proportions  suit- 

*  History  of  the  Cotton  Manufacture,  p.  269.     If  that  strange  farrago  be  employed  by  Mr.  Locket  of 
Maiichoetor,  for  softening  liis  dice  and  mills,  it  deserves  consideration.    Should  the  nitre  be  used  in  too 

Seat  quantity  to  be  all  carbonated  by  the  gall,  its  oxygen  may  serve  to  consume  some  of  the  carbon  of 
9  steel,  aod  thus  bring  it  nearer  to  iron.    The  recipe  may  be  old,  but  it  is  a  novelty  to  me. 


fm 


STEEL. 


STEEL. 


731 


abl«  for  softening  the  granular  particles  of  iron  during  their  combination  with  the 
carbon,  by  keeping  it  for  a  certain  time  at  a  red  heat  with  powdered  charoool,  a  casting 
is  obtained,  which,  when  submitted  to  the  action  of  the  hammer  or  rollers,  furnislies  a 
product  known  as  "steel  of  cementation."  During  this  operation  the  stratum  of  oxide 
which  covers  the  particles  of  iron  inside  loses  its  oxygen,  and  passes  again  into  a  me- 
tallic state ;  but  the  vacant  spaces  occasioned  by  this  are  filled  up,  as  the  ferruginous 
particles,  which  are  in  a  semi-fluid  state,  reassumes  the  crystalline  form.  The  carbonic 
acid  (oxide  f )  gas  in  escaping  forms  lar^e  blisters  on  the  surface  of  the  metal,  under  which 
Uie  softened  mass  crystallizes.  On  being  broken,  the  interior  of  these  blisters,  instead 
of  appearing  of  a  dark  color,  indicating  the  presence  of  a  stratum  of  protoxide,  presents 
8  brilliant  and  rainbow-tinted  appearance,  the  yellowish  and  bluish  tints  distinguisJiing 
bronzed  steel  being  observable.  If  this  steel  be  wrought  at  a  white  heat>  these  blisters 
will  weld  in  with  the  mass  with  the  greatest  facility.  During  cementation  the  carbon 
combines  with  the  component  particles  of  the  iron  in  various  proportions,  depending  in 
a  great  degree  upon  the  chemical  composition  of  those  particles.  It  is  therefore  a  vul- 
gar eiTor  to  suppose  that  steel  of  cementation  contains  more  carbon  at  the  surface  than 
in  the  interior,  as  stated  in  all  technological  treatises.  Thus,  in  the  best  Dannemora 
steel,  it  very  frequently  happens,  when  the  cementation  is  finished,  that  the  centre  of 
the  metal  contains  a  much  greater  quantity  of  carbon  than  in  the  superficial  portions 
It  may  also  happen  that  steel  produced  from  the  best  Dannemora  bar  iron  will  differ 
in  an  extraordinary  manner  as  regards  hardness  in  various  portions  of  the  bar;  and 
for  this  reason,  in  steel  works  in  England,  the  bars  of  steel  are  always  broken  into  several 
pieces,  in  order  to  class  those  pieces  together  which  are  the  most  similar  in  quality. 

If  ordinary  iron  be  submitted  to  cementation,  that  is  to  say,  iron  in  which  the  propor- 
tion of  silica  is  ordinarily  insignificant  when  compared  with  that  of  carbon,  and  if  inde- 
pendently of  this  the  iron  is  deficient  in  the  quantity  of  phosphorus  and  arsenic  necessary 
for  easily  softening  the  metallic  molecules,  only  carburet  oi  iron  and  a  little  siliciuret 
of  iron  are  produced,  but  the  carbon  does  not  combine  with  the  silica.  In  this  case 
the  steel  is  aeficient  in  malleability  and  tenacity,  for  this  reason,  that  the  molecules 
will  not  unite  or  crystallize  until  they  have  taken  up  a  quantity  of  carbon  more  than 
sufficient  to  produce  steel.  With  regard  to  simple  carburetted  iron  (when  it  contains 
more  carbon),  it  either  will  not  harden  at  all  when  tempered,  or  becomes  friable  and 
brittle  when  heated  to  redness,  even  when  it  does  not  contain  more  carbon  than  steel 
of  good  quality. 

The  fracture  of  the  steel  of  cementation,  now  under  notice,  is  gray  and  dull,  while 
steel  of  good  quality  is  of  a  silvery  aspect,  and  presents  cubical  crystals. 

The  best  steel  can  only  be  obtained  by  the  cementation  of  forged  iron ;  whilst  the 
Boetal  is  combining  with  the  carbon,  the  iron  must  not  enter  into  a  complete  state  of 
fusion,  as  in  that  ease  groups  of  crystals,  each  possessing  a  diff^erent  degree  of  ^carbon- 
ization, would  be  formed;  even  the  best  Dannemora  iron  will  not  furnish  a  uniform 
froduct,  fit  for  purposes  of  commerce,  when  melted  with  substances  containing  carbon, 
am  well  aware  that  the  experiments  of  Clouet,  Hachettc,  and  Breant,  may  be  opposed 
to  me,  as  set  forth  in  various  treatises  on  chemistry ;  but  these  are  unfortunately  mere 
laboratory  experiments,  the  authors  of  which  have  prudently  concealed,  or  passed  over 
in  silence,  all  those  which  were  unsuccessful.  When  the  operator  has  obtained  a  regulus 
at  the  bottom  of  his  crucible,  and  when,  after  immense  trouble,  he  has  succeeded  in 
extracting  a  small  portion  of  steel  capable  of  being  worked,  he  immediately  hastens  to 
publish  his  pretended  discovery  in  some  journal,  of  which  others  become  faithful  and 
credulous  echoes :  thus,  since  the  manufacture  of  steel  has  become  the  subject  of  chemical 
inquiry,  complaints  are  daily  becoming  more  frequent  upon  the  difficulty  of  obtaining 
steel  capable  of  resisting  the  treatment  to  which  it  is  subjected  in  the  arts.  If  th^j 
persons  who  preside  over  the  coining  department  either  at  London  or  Munich  were 
consiilted,  they  would  all  agree  in  saying  that  it  is  now  very  difficult  to  meet  with  the 
quality  of  steel  necessary  for  making  the  dies.  Even  in  England  good  steel  becomes 
more  and  more  scarce.  With  regard  to  the  manufactories  of  cemented  or  cast  steel 
established  upon  the  Continent,  they  furnish  products  the  quality  of  which  is  so  uncer- 
tain that  the  workman  is  often  reduced,  after  having  lost  his  time  and  trouble,  to  throw 
certain  portions  away,  as  they  want  the  necessary  uniformity  and  tenacity. 

All  the  artificial  alloys  of  silver  with  steel,  of  which  so  much  has  been  said,  are  not 
fit  for  anything,  and  are  never  met  with  in  commerce. 

When  the  steel  has  been  withdrawn  from  the  cementing  furnace,  and  after  it  has  been 
broken  and  the  pieces  drawn  out,  they  are  submitted  to  one  of  the  two  following 
operations :-— The  pieces,  after  being  sorted,  are  piled  one  upon  the  other  and  welded 
together  (this  is  called  iPaggoting  the  steel) ;  or  the  sorted  pieces  are  placed  in  clay 
crucibles  of  a  nearly  cylindrical  form,  and  cast  in  a  reverberatory  furnace,  in  which  two 
crucibles  are  placed,  one  behind  the  other  upon  cakes  of  fire  clay ;  the  orifice  of  these 
crucibles  is  closed  by  a  flat  cake  of  fire  clay.    The  bars  of  cemented  steel,  as  above 


mentioned,  arc  divided  into  pieces  of  one  or  two  inches  in  length ;  these  pieces  are 
distributed,  according  to  their  degree  of  carbonization,  in  vessels  fixed  to  the  walls  ol 
the  place  in  which  the  melting  is  carried  on.  . 

These  diflferent  qualities  of  steel  are  generally  combined  in  such  a  manner  as  to  obtain 
a  product  the  best  suited  for  the  purposes  to  which  cast  steel  is  ordinarily  applied.     ^ 

In  all  treatises  on  practical  chemistry  it  is  asserted  that,  in  order  to  melt  steel,  it  is 
to  be  covered  with  a  layer  of  glass  or  blast  furnace  slag;  that  the  opening  of  the  crucible 
is  luted,  or  at  least  becomes  firmly  fixed  during  the  operation;  these  assertions  are 
however  erroneous.  In  the  first  steel  manufactories  in  Sheffield,  steel  only  is  put  into 
the  crucibles.  With  regard  to  the  cover  it  is  evident  that  it  must  adhere  to  the  crucible, 
as  it  is  necessary  the  operator  should  remove  it  from  time  to  time  with  a  bar  of  iron 
in  order  to  ascertain  the  etate  of  the  metal.  ' 

In  order  to  obtain  steel  of  the  first  quality,  it  is  not  sufficient  that  the  melted  mass 
be  run  into  moulds;  the  most  essential  point  is  to  make  the  casting  at  the  proper  time, 
and  for  this  purpose  the  operator  must  be  guided  by  the  quality  of  the  steel.  This  is 
the  duty  of  the  workman,  who  from  long  practice  can  tell  the  suitable  point  of  fusion, 
either  by  simple  inspection,  or  by  means  of  his  bar  of  iron,  with  which  he  merely  touches 
the  sur^ce  of  the  metal,  being  most  careful  not  to  plunge  it  into  the  melted  mass.  As 
the  quality  and  uniformity  of  the  steel  depend  in  a  great  measure  upon  the  experience 
and  judgment  of  the  workman  who  directs  the  casting,  it  follows  that^  even  in  England, 
a  good  caster  is  much  sought  after  and  well  paid. 

It  is  not  difficult,  therefore,  to  explain  why  so  many  of  the  attempts  made  to  establish 
manufactories  of  cast  steel  in  Germany  have  failed,  and  will  again  fail.  Thanks  to  the 
errors  propagated  by  technical  works,  and  by  the  assertions  of  superficially  informed 
travellers,  who  had  frequently  been  purposely  deceived,  it  was  imagined  that  in  order 
to  obtain  English  steel  of  good  quality,  it  was  only  necessary  to  melt  cemented  steel  in 
a  crucible,  and  afterward  pour  it  into  moulds  when  in  a  state  of  fusion. 

As  soon  as  a  crucible  is  emptied,  it  is  replaced  in  the  oven ;  each  crucible  serves  for 
one  day's  work,  i.e.  four  or  five  castings,  after  which  it  is  thrown  aside.  For  ordinary 
purposes,  the  steel  is  run  into  cast-iron  moulds  of  a  prismatic  form,  previousljr  heated 
and  closed.  When  the  steel  is  required  for  making  saw-blades,  plates,  Ac,  it  is  run 
into  large  moulds  of  a  parallelopiped  form.  Steel  which  is  very  hard  and  highly  car- 
bonized, contracts  considerably  in  the  moulds ;  great  skill  is  therefore  required  to  run 
it  into  the  moulds  in  such  a  manner  that  no  vacuum  may  be  produced.  In  that  part  of 
the  prism  corresponding  to  the  jet,  a  funnel-shaped  aperture  from  1  to  2  inches  deep  is 
formed ;  this  is  detached  and  melted  down  with  other  pieces  of  steel. 

'  The  transverse  fracture  of  a  prism  of  hard  steel  is  silvery,  and  has  a  number  of  rays 
radiating  from  the  centre ;  steel  less  hard  is,  on  the  contrary,  of  a  uniform  granular 
and  crystalline  texture.     This  steel  possesses  all  the  brittleness  of  cast  metal. 

By  fusion,  steel  of  cementation  acquires  peculiar  properties,  and  does  not  sweat  so 
much  as  before  casting. 

When  steel  is  produced  from  iron  of  bad  quality,  and  carburets  of  a  different  nature 
are  produced  during  cementation,  the  melting,  instead  of  improving  it,  renders  it  much 
•worse ;  as,  in  that  case,  the  different  carburets  of  iron,  which  are  of  inferior  quality, 
separate  still  more  during  cooling.  This  has  given  rise  to  an  old  saying,  well  known 
among  English  founders,  that  "when  the  devil  is  put  into  the  crucible,  nothing  but  the 
devil  will  come  out" 

It  is  to  the  existence  of  these  heterogeneous  metallic  carburets,  which  are  produced 
during  cementation  in  iron  of  inferior  quality,  and  which  forms  new  combinations  during 
the  fusion  of  the  metal,  that  the  complaints  of  workmen  working  in  steel  are  to  be 
attributed.  In  fact,  these  carburets  being  only,  so  to  speak,  agglutinated,  even  in  bars 
of  forged  steel,  each  of  them  at  the  moment  of  tempering  is  contracted  or  dilated  more 
or  less  than  the  one  immediately  adjoining  it,  so  that  from  that  time  a  separation  cona- 
mences  between  the  unequally  carbonized  layers ;  in  other  words  a  flaw  or  crack  is 
produced,  which  may  be  distinguished  by  a  peculiar  noise  at  the  moment  when  the 
steel  is  plunged  in  the  water,  or  at  least  there  is  a  tendency  to  separation,  which  only 
requires  the  cooperation  of  an  exterior  cause,  such  as  a  shock,  to  effect  This  is  often 
observed  in  razors,  &c. 

The  transverse  fracture  of  cast  steel  ought  to  present  a  perfectly  homogeneous  surface 
when  the  bar  is  broken  by  a  sharp  blow,  after  being  cut  or  marked  with  a  chisel.  The 
slight  inequalities  which  are  perceptible  ought  to  be  undulating,  and  to  blend  insensibly 
at  their  bases  with  the  rest  of  the  metallic  surface.  When,  on  the  contrary,  they  stand 
out  perpendicularly,  the  conclusion  may  be  arrived  at,  that  this  portion  of  the  bar  was 
the  point  of  contact  of  two  unequally-carbonized  layers,  which,  by  separating  either  at 
the  moment  of  tempering  or  at  a  later  period,  had  inevitably  given  rise  to  this  rupture. 
Indian  steel,  or  wootz. — ^The  wootz  ore  consists  of  the  magnetic  oxide  of  iron,  united 
with  quartz,  in  proportions  which  do  not  seem  to  differ  much,  being  generally  about  42 


732 


STEEL. 


STEEL. 


733 


4 


■ill 


of  quartz,  and  58  of  magnetic  oxyde.  Its  grains  are  of  various  size,  down  to  a  sandy  tex^ 
ture.  The  natives  prepare  it  for  smeltins:  by  pounding  the  ore,  and  winnowin*  away 
the  stony  matrix,  a  task  at  which  the  Hindoo  females  are  very  dexterous.  The  manner 
in  which  iron  ore  is  smelted  and  converted  into  wootz  or  Indian  steel,  by  the  natives  at 
the  present  day,  is  probably  the  very  same  that  was  practised  by  them  at  the  time  of  the 
invasion  of  Alexander;  and  it  is  a  uniform  process,  from  the  Himalaya  mountains  to  Cap€ 
Comorin.  The  furnace  or  bloomery  in  which  the  ore  is  smelted,  is  from  four  to  five  feel 
high;  It  is  somewhat  pear-shaped,  being  about  two  feet  wide  at  bottom,  and  one  foot  af 
top;  It  IS  built  entirely  of  clay,  so  that  a  couple  of  men  can  finish  its  erection  in  a  few 
hours,  and  have  it  ready  for  use  the  next  day.  There  is  an  opening  in  front  about  a  foot 
or  more  m  height,  which  is  built  up  with  clay  at  the  commencement,  and  broken  down 
at  the  end,  of  each  smelting  operation.  The  bellows  are  usually  made  of  a  goat's  skin, 
which  has  been  stripped  from  the  animal  without  ripping  open  the  part  covering  the  belly. 
The  apertures  at  the  legs  are  tied  up,  and  a  nozzle  of  bamboo  is  fastened  in  the  opening 
formed  by  the  neck.  The  orifice  of  the  tail  is  enlarged  and  distended  by  two  slips  of 
bamboo.  These  are  grasped  in  the  hand,  and  kept  close  together  in  making  the  stroke 
for  the  blast;  in  the  returning  stroke  they  are  separated  to  admit  the  air.  By  working 
a  bellows  of  this  kind  with  each  hand,  making  alternate  strokes,  a  pretty  uniform  blast 
IS  produced.  The  bamboo  nozzles  of  the  bellows  are  inserted  into  tubes  of  clay,  which 
pass  into  the  furnace  at  the  bottom  corners  of  the  temporary  wall  in  front.  The  furnace 
IS  filled  with  charcoal,  and  a  lighted  coal  heinjj  introduced  before  the  nozzles,  the  mass 
in  the  interior  is  soon  kindled.  As  soon  as  this  is  accomplished,  a  small  portion  of  the 
ore,  previously  moistened  with  water,  to  prevent  it  from  running  through  the  charcoal, 
but  without  any  flux  whatever,  is  laid  on  the  top  of  the  coals,  and  covered  with  charcoal 
to  fill  up  the  furnace. 

In  this  manner  ore  and  fuel  are  supplied;  and  the  bellows  are  urged  for  3  or  4  hours, 
when  the  process  is  stopped;  and  the  temporary  waU  in  front  being  broken  down,  the 
bloom  IS  removed  by  a  pair  of  tongs  from  the  bottom  of  the  furnace.  It  is  then  beaten 
with  a  wooden  mallet,  to  separate  as  much  of  the  scoriae  as  possible  from  it,  and,  while 
Btill  red-hot,  it  is  cut  through  the  middle,  but  not  separated,  in  order  merely  to  show 
Ihe  quality  of  the  interior  of  the  mass.  In  this  state  it  is  sold  to  the  blacksmiths, 
who  make  it  mto  bar  iron.  The  proportion  of  such  iron  made  by  the  natives  from  100 
parts  of  ore,  is  about  15  parts.  In  converting  the  iron  into  steel,  the  natives  cut  it  into 
pieces,  to  enable  it  to  pack  better  in  the  crucible,  which  is  formed  of  refractory  clay, 
mixed  with  a  large  quantity  of  charred  husk  of  rice.  It  is  seldom  charged  with  more 
than  a  pound  of  iron,  which  is  put  in  with  a  proper  weight  of  dried  wood  chopped 
small,  and  both  are  covered  with  one  or  two  green  leaves ;  the  proportions  being  in 
general  10  parts  of  iron  to  1  of  wood  and  leaves.  The  mouth  of  the  crucible  is  then 
stopped  with  a  handful  of  tempered  clay,  rammed  in  very  closely,  to  exclude  the  air.  Th« 
wood  preferred  is  the  Cassia  anriculata,  and  the  leaf  that  of  the  ^sckpias  zieanteay  or 
the  Convolmilus  laurifolius.  As  soon  as  the  clay  plugs  of  the  crucibles  are  Ur>',  from 
20  to  J4  of  them  are  built  up  in  the  form  of  an  arch,  in  a  small  blast  furnace;  they  are 
icept  covered  with  charcoal,  and  subjected  to  heat  urged  by  a  blast  for  about  two  hours 
and  a  half,  when  the  process  is  considered  to  be  complete.  The  crucibles  beino-  now 
taken  out  of  the  furnace  and  allowed  to  cool,  are  broken,  and  the  steel  is  foSnd  in 
theform  of  a  cake,  rounded  by  the  bottom  of  the  crucible.  When  the  fusion  has  been 
perfect,  the  top  of  the  cake  is  covered  wirh  striae,  radiating  from  the  centre,  and  is  free 
from  holes  and  rough  projections  ;  but  if  the  fusion  has  been  imperfect,  the  surface  of 
the  cake  has  a  honeycomb  appearance,  with  projecting  lumps  of  malleable  iron.  On  un 
average,  four  out  of  five  cakes  are  more  or  less  defective.  These  imperfections  have 
been  tried  to  be  corrected  in  London  by  re-melting  the  cakes,  and  running  them  into 
ingots ;  but  it  is  obvious,  that  when  the  cakes  consist  partially  of  malleable  iron  and  of 
unreduced  oxyde,  simple  fusion  cannot  convert  them  into  good  steel.  When  care  is  taken 
however,  to  select  ouly  such  cakes  as  are  perfect,  to  re-melt  them  thoroughly,  and 
tilt  them  carefully  into  rods,  an  article  has  been  produced  which  possesses  all  the  re- 
quisites  of  fine  steel  m  an  eminent  degree.  In  the  Supplement  to  the  Encyclopaedia 
Britannica,  article  Cutlery,  the  late  Mr.  Stodart,  of  the  Strand,  a  very  competent  jud-e, 
has  declared  « that  for  the  purposes  of  fine  cutlery,  it  is  infinitely  superior  to  the  best 
English  cast  steel." 

The  natives  prepare  the  cakes  for  being  drawn  into  bars  by  annealing  them  for  several 
Hours  m  a  small  charcoal  furnace,  actuated  by  bellows ;  the  current  of  air  beino-  made 
to  play  upon  the  cakes  while  turned  over  before  it ;  whereby  a  portion  of  the  combined 
carbon  is  probably  dissipated,  and  the  steel  is  softened ;  without  which  operation  the 
cakes  would  break  in  the  attempt  to  draw  them.  They  are  drawn  by  a  hammer  of  a  lew 
pounds  weight. 

The  natives  weld  two  pieces  of  cast  steel,  by  giving  to  each  a  sloping  face  jagged  all 
ever  with  a  small  chisel ;  then  applying  them  with  some  calcined  borax  between,  and 


tying  them  together  with  a  wire,  they  are  brought  to  a  full  red  heat,  and  united  by  a 
few  smart  blows  of  a  hammer. 

The  ordinary  bar  iron  of  Sweden  and  England,  when  converted  by  cementation  into 
Bteel,  exhibits  upon  its  surface  numerous  small  warty  points,  but  few  or  no  distinct 
vesicular  eruptions ;  whereas  the  Dannemora  and  the  Ulverston  steels  present,  all  over 
the  surface  of  the  bare,  well  raised  blisters,  upwards  of  three-eighths  of  an  inch  in  di- 
ameter horizontally,  but  somewhat  flattened  at  top.  Iron  of  an  inferior  description, 
when  highly  converted  in  the  cementing-chest,  becomes  gray  on  the  outer  edges  of  the 
fracture;  while  that  of  Dannemora  acquires  a  silvery  color  and  lustre  on  the  edges, 
with  crystalline  facets  within.  The  highly  converted  steel  is  used  for  tools  that  re- 
quire to  be  made  very  hard ;  the  slightly  converted,  for  softer  and  more  elastic  articles> 
such  as  springs  and  sword  blades. 

One  of  the  greatest  improvements  which  this  valuable  modification  of  iron  has  ever 
received  is  due  to  the  late  Mr.  Josiah  M.  Heath,  who,  after  many  elaborate  and  costly 
researches,  upon  both  the  small  and  the  great  scale,  discovered  that  by  the  introduction  of 

1362 


1863 


1864 


annall  portion,  1  per  cent,  and  even  less,  of  carburet  of  manganese  into  the  melting-pot 
along  with  the  usual  broken  bars  of  blistered  steel,  a  cast  steel  was  obtained,  after  f  usioD,of 


734 


STEEL. 


STEREOTYPE  PRINTING. 


735 


I 


iiSI ! 


a  quality  very  superior  to  "wrhat  the  bar  steel  would  have  yielded  without  the  manganese, 
and  moreover  possessed  of  the  new  and  peculiar  property  of  being  weldable  either  to 
itself  or  to  wrought  iron.  He  also  found  that  a  common  bar-steel,  made  from  an  in- 
ferior mark  or  quality  of  Swedish  or  Russian  iron,  would,  when  so  treated,  produce  an 
excellent  cast  steel.  One  immediate  consequence  of  this  discovery  has  been  the  re-  , 
duction  of  the  price  of  good  steel  in  the  Sheffield  market  by  from  30  to  40  per  cent., 
and  likewise  the  manufacture  of  table-knives  of  cast  steel  with  iron  tangs  welded  to 
them ;  whereas,  till  Mr.  Heath's  invention,  table-knives  were  necessarily  made  of  sheer- 
steel,  with  unseemly  wavy  lines  in  them,  because  cast  steel  could  not  be  welded  to 
the  tangs.  Mr.  Heath  obtained  a  patent  for  this  and  other  kindred  meritorious  in- 
ventions on  the  5th  of  April,  1889;  but,  strange  and  melancholy  to  say,  he  never  de- 
rived any  thing  from  his  acknowledged  improvement  but  vexation  and  loss,  in  con- 
sequence of  a  numerous  body  of  Sheffield  steel  manufacturers  having  banded  together 
to  pirate  his  patent.,  and  to  baffle  him  in  our  complex  law  courts.  I  hppe,  however, 
that  eventually  justice  will  have  its  own,  and  the  ridiculously  unfounded  pretences  of 
the  pirates  to  the  prior  use  of  carburet  of  manganese  will  be  set  finally  at  rest.  It  is 
supposed  that  fifty  persons  at  least  embarked  in  this  pilfering  conspiracy.  By  a  re- 
cent decision  of  the  Judicial  Committee  of  the  Privy  Council,  the  heirs  of  Mr.  Heath 
have  obtained  a  prolongation  of  the  term  of  the  patent  for  seven  years  from  this  date, 
February,  1853. 

The  furnace  of  cementation  in  which  bar-iron  is  converted  into  bar  or  blistered  steel 
is  represented  in  Jigs.  1362,68,64.  It  is  rectangular  and  covered  in  by  a  groined  or 
cloister  arch :  it  contains  two  cementing  chests,  or  sarcophaguses,  c,  c,  made  either  of 
fire-stone  of  fire-bricks :  each  is  2^  feet  wide,  3  feet  deep,  and  12  long;  the  one  being 
placed  on  the  one  side,  and  the  other  on  the  other  of  the  grate,  a,  b,  which  occupies  the 
whole  length  of  the  furnace,  and  is  from  13  to  14  feet  long.  The  grate  is  14  inches 
broad,  and  rests  from  10  to  12  inches  below  the  inferior  plane  or  bottom  level  of  the 
chests;  the  height  of  the  top  of  the  arch  above  the  chests  is  5|  feet ;  the  bottom  of  the 
chests  is  nearly  on  a  level  with  the  ground,  so  that  the  bars  do  not  need  to  be  lifted 
high  in  charging  the  furnace.  The  flame  rises  between  the  two  chests,  passes  also 
below  and  round  them  through  the  horizontal  and  vertical  flues,  d,  and  issues  from  the 
furnace  by  an  opening,  h,  in  the  top  of  the  vault,  and  by  orifices,  t,  which  communicate 
with  the  chimneys  placed  in  the  angles.  The  whole  is  placed  within  a  large  cone  of 
bricks,  25  or  30  feet  high,  and  open  at  top :  this  cone  increases  the  draught,  makes  it 
more  regular,  and  carries  off  the  smoke  away  from  the  establishment.  The  furnace 
has  three  doors;  two,  t  (fg.  1363),  above  the  chests,  serve  to  admit  and  to  remove  the 
bars ;  they  are  about  7  or  8  inches  square :  in  each  of  them  a  piece  of  sheet-iron  is  put, 
folded  back  on  its  edges;  upon  which  the  bars  are  made  to  slide,  so  as  to  save  the  wall. 
A  workman  enters  by  the  middle  door,  p,  to  arrange  the  bars ;  the  trial  bars  are  taken 
out  from  time  to  time  by  the  apertures,  s,  (fg.  1362.)  left  in  the  sides  of  the  chests. 
The  bars  are  laid  in  strata,  along  with  wood  charcoal  in  powder,  in  the  said  chests; 
they  are  about  three  inches  broad,  and  one-third  of  an  inch  thick ;  they  must  not  be 
placed  too  near  each  other,  lest  they  should  get  welded  together;  the  air  or  uppermost 
layer  is  covered  with  a  stratum  of  loamy  matter  from  4  to  6  inches  thick.  The  furnace 
must  be  gradually  heated,  not  reaching  its  maximum  temperature  before  8  or  9  days, 
and  the  cooling  lasts  5  or  6  days;  the  whole  operation  18  or  20  days,  and  sometimes 
more,  according  to  the  quality  of  the  steel  to  be  cemented.  About  13  tons  of  coals  are 
consumed  in  this  period.  It  is  of  consequence  that  the  refrigeration  be  slow,  to  favor 
the  crystallization  of  the  metal.  The  grain  of  the  steel  varies  with  the  rate  of  cooling, 
the  largest  and  whitest  grain  denoting  the  most  fusible  steel. 

Heavy  Steel.  E.  Thomas,  JcTcnield  works,  Birminqham,  manufacturer.  The  articles 
exhibited  illustrated  the  heavy  steel  "  toy"  trade  of  Birmingham.  Brazil  axes ;  Ame- 
rican wedge  axes,  and  hand  hatchet ;  shingling  hatchets,  assorted  patterns ;  coopers* 
adze  and  axe;  round  and  square  eye  adze;  mahogany  squaring  axe;  English  car- 
penter's axe;  eyed  shell  and  screw  auger;  double  plane  iron;  socket  chisel;  trowel; 
gun  and  hand  harpoons;  improved  grass  shears;  and  a  variety  of  garden  tools,  to  screw 
into  one  handle.  The  manufacture  of  the  axe  used  by  the  backwoods-men,  of  the  hoe  used 
in  the  agriculture  of  the  tropics,  the  pick  used  by  the  Caffirs  of  the  Cape,  and  the  harpoon 
of  the  whale-fisher,  give  employment  to  many  artizans  of  its  vicinity.  In  order  to  convey 
a  general  idea  of  the  process  by  which  these  articles  are  "got  up,"  the  manufacture  of  an 
ordinary  axe  may  be  selected.  A  piece  of  iron  is  taken,  and  after  being  heated  is  doubled 
over  a  piece  of  steel,  corresponding  in  form  to  the  future  eye  which  is  to  hold  the  shank; 
is  not  then  welded  together.  A  small  piece  of  steel  which  is  intended  to  form  the 
future  cutting  edge,  is  heated  along  with  the  iron  back  to  a  welding  heat,  and  is  passed 
under  a  tilt  hammer  (that  is,  a  large  hammer  driven  by  steam  or  water),  which  speedily 
flattens  it  out ;  it  is  then  exposed  to  another  heat,  and  the  eye  is  completed  with  the  small 
hammer.    The  superfluous  iron  or  steel  is  removed  by  a  pair  of  lai^e  scissors.    The 


the  process  of  hardening  and  tempering  follow ;  the  grinding  is  performed  on  stones 
which  out  away  the  iron  and  disclose  the  steel  edge.  The  "glazing"  on  emery  "bobs" 
or  wheels  succeeds,  and  the  polishing  is  effected  by  means  of  emery  and  oil  on  a  similar 
tool.  Considerable  improvement  in  appearance  is  imparted  by  the  use  of  a  blue  var 
nish  which  is  applied  to  the  axe,  and  drying  in  a  small  stove.  "Toy"  is  a  technical  term 
applied  to  an  anvil,  a  hammer,  and  various  other  objects  which  are  comprised  under 
the  term  "  heavy  steel" 

In  the  year  1843,  25,000  tons  of  steel  were  annually  converted  in  this  country,  and 
of  that  quantity  not  more  than  2,500  were  made  from  the  best  Swedish  iron. 

For  the  remainder,  inferior  qualities  of  iron,  such  as  the  Russian  iron  marked  CCND, 
from  the  foiges  of  Count  Demidoff,  were  used ;  that  iron  was  made  with  charcoal,  and 
could  be  caUed  inferior  only  when  compared  with  that  made  from  the  Dannemora 
ore. 

STEEL  PLATE  ENGRAVING.  An  entire  change  in  engraving  has  taken  place  by 
the  substitution  of  steel  for  copper  plates.  An  engraving  made  upon  copper  is  speedily 
rendered  useless  by  the  process  of  jnking,  and  the  friction  necessary  to  remove  the  sn- 
perfluous  ink.  The  rubbing  with  whitening  to  clean  the  face  of  the  plate  wears  away 
the  surface  and  renders  it  valueless  after  a  few  thousand  impressions. 

The  Queen's  head  on  the  postage  stamp  has  been  only  once  engraved.  It  had,  in 
1842,  been  multiplied  6,000  times — that  is  to  say,  the  original  produced  6,000  plates, 
which  printed  all  the  postage  stamps  of  the  above  kind  which  had  been  used  since  the 
introduction  of  Rowland  Hill's  measure  up  to  the  period  stated. 

The  multiplication  of  a  steel  plate  is  a  feature  of  some  importance :  a  plate  is  en- 
graved and  hardened ;  from  this  an  impression  is  taken  upon  a  softened  steel  roller ; 
Siis  steel  roller  is  then  hardened,  and  softened  steel  plates  being  passed  under  it,  an 
impression  is  imparted  to  them ;  they  are  then  hardened,  and  are  equal  to  the  origioaj 
as  to  their  impressions.  This  method  is  adopted  in  bank-note  engraving ;  and  the 
postage  stamp  plates  are  produced  by  the  same  meana 

STEREOTYPE  PRINTING  signifies  printing  by  fixed  types,  or  by  a  cast  typo- 
graphic plate.    This  plate  is  made  as  follows : — The  form,  composed  in  ordinary  types, 
and  containing  one,  two,  three,  or  more  pages,  inversely  as  the  size  of  the  book,  being 
laid  flat  upon  a  slab,  with  the  letters  looking  upwards,  the  faces  of  the  types  are  brushed 
over  with  oil,  or  preferably,  with  plumbago  (black  lead.)     A  heavy  brass  rectangulal 
fratne  of  three  sides,  with  bevelled  borders,  adapted  exactly  to  the  size  of  the  pages,  it 
then  laid  down  upon  the  chase,*  to  circumscribe  three  sides  of  its  typography ;  but  Iha 
fourth  side,  which  is  one  end  of  the  rectangle,  is  formed  by  placing  near  the  types,  and 
over  the  hollows  of  the  chase,  a  single  brass  bar,  having  the  same  inwards  sloping  bevel 
as  the  other  three  sides.    The  complete  frame  resembles  that  of  a  picture,  and  serves  to 
define  the  area  and  thickness  of  the  cast,  which  is  made. by  pouring  the  pap  of  Paris 
plaster  into  its  interior  space,  up  to  a  given  line  on  its  edges.    The  plaster  mould,  which 
soon  sets,  or  becomes  concrete,  is  lifted  gently  oflf  the  types,  and  inmiediately  placed 
upright  on  its  edge  in  one  of  the  cells  of  a  sheet-iron  rack,  mounted  within  the  cast-iron 
oven.     An  able  workman  will  mould  ten  sheets  octavo  in  a  day,  or  160  pages.     The 
moulds  are  here  exposed  to  air  heated  to  fully  400°  F.,  and  become  perfectly  dry  in  the 
course  of  two  hours.     As  they  are  now  friable  and  porous,  they  require  to  be  delicately 
handled.     Each  mould,  containing  generally  two  pages  octavo,  is  laid,  with  the  im- 
pression downwards,  upon  a  flat  cast-iron  plate,  called  the  floating-plate ;  this  plate 
being  itself  laid  on  the  bottom  of  the  dipping-pan,  which  is  a  cast-iron  square  tray. 
With  its  upright  edges  sloping  outwards.    A  cast-iron  lid  is  applied  to  the  dipping-pan, 
and  secured  in  its  place  by  a  screw.     The  pan  having  been  heated  to  400°  in  a  cell  of 
the  oven,  under  the  mould-rack,  previous  to  receiving  the  hot  mould,  is  ready  to  be 
plunged  into  the  bath  of  melted  alloy  contained  in  an  iron  pot  placed  over  a  furnace, 
.Jind  it  is  dipped  with  a  slight  deviation  from  the  horizontal  plane,  in  order  to  facilitate 
the  escape  of  the  air.    As  there  is  a  minute  space  between  the  back  or  top  surface  of 
the  mould  and  the  lid  of  the  dipping-pan,  the  liquid  metal,  on  entering  into  the  pan 
through  the  orifices  in  its  corners,  floats  up  the  plaster  along  with  the  iron  plate  on 
which  it  had  been  laid,  thence  called  the  floating-plate,  whereby  it  flows  freely  into  every 
line  of  the  mould,  through  notches  cut  in  its  edge,  and  forms  a  layer  or  lamina  upon  ite 
face,  of  a  thickness  corresponding  to  the  depth  of  the  border.    Only  a  thin  metal  film 
is  left  upon  the  back  of  the  mould.    The  dipping-pan  is  suspended,  plunged,  and  removed 
by  means  of  a  powerful  crane,  susceptible  of  vertical  and  horizontal  motions  in  all  direc- 
tions.    "When  lifted  out  of  the  bath,  it  is  set  in  a  water-cistern,  upon  bearers  so  placed 
as  to  allow  its  bottom  only  to  touch  the  surface.    Thus  the  metal  first  concretes  below, 

*  Chase  {ckoBait,  frame,  Fr.),  quoin  Uoin,  wedge,  Kr.)  are  terms  which  show  that  the  art  of  printixig 
came  directly  from  France  to  Eiigland. 


736 


STEVENSON'S  REVOLVING  LIGHTHOUSE. 


STEVENSON'S  REVOLVING  LIGHTHOUSE. 


737 


''isn 


I 


fil! 


while  by  remaining  fluid  above,  it  continues  to  impart  hydrostatic  pressure  during 
the  shrinkage  attendant  upon  refrigeration.  As  it  thus  progressively  contracts  in  volume, 
more  melted  metal  is  fed  into  the  corners  of  the  pan  by  a  ladle,  in  order  to  keep  up  the 
hydrostatic  pressure  upon  the  mould,  and  to  secure  a  perfect  impression,  as  well  as  a  solid 
cast  Were  the  pan  more  slowly  and  equably  cooled,  by  being  left  in  the  air,  the  thin 
film  of  metal  upon  the  back  of  the  inverted  plaster  cake  would  be  apt  to  solidify  firsts 
and  intercept  the  hydrostatic  action  indispensable  to  the  purpose  of  filling  all  the  lines 
in  its  face.  A  skilful  workman  makes  five  dips,  containing  two  pages  octavo  each  in 
the  course  of  an  hour,  or  about  nine  and  a  half  octavo  sheets  per  day.  The  pan  being 
taken  asunder,  the  compound  cake  of  mould  and  metal  is  removed,  and  beat  upon  ite 
edges  with  a  wooden  mallet,  to  detach  the  superfluous  metaL  The  stereotype  plate  is 
then  handed  over  to  the  picker,  who  planes  its  edges  truly  square,  turns  its  back  flat 
upon  a  lathe  to  a  determinate  thickness,  and  carefully  removes  the  little  imperfections 
occasioned  by  dirt  or  air  left  among  the  letters  when  the  mould  was  cast  Should  any 
of  them  be  damaged  in  the  course  of  the  operation,  they  must  be  cut  out>  and  replaced 
by  soldering  in  separate  types  of  the  same  size  and  form. 

STEVENSON'S  REVOLVING  LIGHTHOUSE.  This  apparatus  consists  of  two 
parts.  The  principal  part  is  a  right  octagonal  hollow  prism  composed  of  eight  large 
lenses,  which  throw  out  a  powerful  beam  of  light  whenever  the  axis  of  a  single  lens 
comes  in  the  line  between  the  observer  and  the  focus.  This  occurs  once  in  a  minute, 
as  the  frame  which  bears  the  lense  revolves  in  eight  minutes  on  the  rollers  place  be- 
neath. The  subsidiary  parts  consist  of  eight  pyramidal  lenses  inclined  at  an  angle  of 
80°  to  the  horizon,  and  forming  together  a  hollow  truncated  cone,  which  rests  above 
the  flame  like  a  cap.  Above  these  smaller  lenses  (which  can  only  be  seen  by  looking 
from  below)  are  placed  eight  plain  mirrors,  whose  surfaces  being  inclined  to  the  horizon 
at  60°  in  the  direction  opposite  to  that  of  the  pyramidal  lenses,  finally  causes  all  the 
Mght  made  parallel  by  the  refraction  of  these  lenses  to  leave  the  mirror  in  a  horizontal 
direction.  The  only  object  of  this  part  is  to  turn  to  useful  account,  by  prolonging  the 
duration  of  the  flash,  that  part  of  the  light  which  would  otherwise  escape  into  the  at- 
mosphere above  the  main  lenses.  This  is  effected  by  giving  to  the  upper  lenses  a  slight 
horizontal  divergence  from  the  vertical  plane  of  the  principal  lenses.  Below  are  five 
tiers  of  totally  reflecting  prisms,  which  intercept  the  light  that  passes  below  the  great 
lenses,  and  by  means  of  two  reflections  and  an  intermediate  refraction  project  them  in 
the  shape  of  a  flat  ring  to  the  horizon. 

Fixed  dioptric  apparatus  of  the  first  order  (same  as  that  at  the  Isle  of  May,  with  va- 
rious improvements).  The  principal  part  consists  of  a  cylindric  belt  of  glass  which 
surrounds  the  flame  in  the  centre,  and  by  its  action  refracts  the  light  in  a  vertical  di- 
rection upward  and  downward,  so  as  to  be  parallel  with  the  focal  plane  of  the  system. 
In  this  way  it  throws  out  a«at  ring  of  light  equally  intense  in  every  direction.  To  near 
observers,  this  action  presents  a  narrow  vertical  band  of  light  depending  for  its  breadth 
on  the  extent  of  the  horizontal  angle  embraced  by  the  eye.  This  arrangement  therefore 
fulfils  all  the  conditions  of  a  fixed  lights  and  surpasses  in  effect  any  arrangement  of  par- 
abolic reflectors.  In  order  to  save  the  light  which  would  be  lost  in  passin*^  above  and 
below  the  cylindrical  belt,  curved  mirrors  with  their  common  focus  in  the  lamp  were 
formerly  used;  but  by  the  present  engineer,  the  adaptation  oi catadioptric zouqs,  to  this 
part  of  the  apparatus  was,  after  much  labor,  successfully  carried  out  These  zones  are 
triangular,  and  act  by  a  total  reflexion,  the  inner  face  refracting,  the  second  totally  re- 
flecting, and  the  third  or  outer  face,  a  second  time  refracting,  so  as  to  cause  the  light  to 
emerge  horizontally.  The  apparatus  has  received  many  smaller  changes  by  the  intro- 
duction of  a  new  mode  of  grouping  the  various  parts  of  the  frame  work,  by  which  the 
passage  of  the  light  is  less  obscured  in  every  azimuth.  During  the  last  four  years  these 
improvements  have  been  introduced  into  the  lighthouses  of  Scotland. 

Mechanical  lamps  of  four  wicks,  in  which  the  oil  is  kept  continually  overflowing  by 
means  of  pumps  which  raise  it  from  the  cistern  below ;  the  rapid  carbonization  of  the 
wicks,  which  would  be  caused  by  the  great  heat  is  thus  avoided.  The  flames  of  the  lamp 
reach  their  best  effect  in  three  hours  after  lighting,  i.  e.  after  the  whole  of  the  oil  in  tho 
cistern,  by  passing  and  repassing  over  the  wicks  repeatedly,  has  reached  its  maximum 
temperature.  After  this  the  lamp  often  burns  14  hours  without  sensible  diminution  of 
the  light,  and  then  rapidly  falls.  The  height  varies  from  16  to  20  times  that  of  the  Argand 
flame  of  an  inch  in  diameter;  and  the  quantity  of  oil  consumed  by  it  is  greater  nearly 
in  the  same  proportion.  ./  o  j 

Revolving  light  with  axial  rotation,  by  which  one  half  the  number  of  reflectors  and 
one  half  the  quantity  of  oil  are  designed  to  be  saved.  Intended  for  illuminating  any 
arch  of  not  more  than  180°.  The  intervals  of  time  of  illumination  are  equal  within 
the  whole  of  the  illuminated  arch,  instead  of  unequal  as  in  the  reciprocating  light  The 
reflectors  are  also  of  a  new  form  consisting  of  parabolic  strips  of  different  focal  diatancea; 


Ordinary  parabolic  reflector  rendered  holophotal  (where  the  entire  light  is  parallel- 
ieed)  by  a  portion  of  a  catadioptric  annular  lens.  The  back  part  of  the  parabolic 
conoid  is  cut  off,  and  a  portion  of  a  spherical  mirror  substituted,  so  as  to  send  the  rays 
again  through  the  flame.  All  the  light  intercepted  by  the  annular  lens  is  lost  in  the 
ordinary  reflector. 

Holophotal  catadioptric  annular  lens  apparatus  (unfinished).  This  is  a  combination  ot 
a  hemispherical  mirror,  and  a  lens  with  totally  rellecting  zones  ;  the  peculiarity  of  this 
arrangement  is,  that  the  catadioptric  zones,  instead  of  transmitting  the  light  in  parallel 
horizontal  j)late8,  as  in  Fresnel's  apparatus,  produces,  as  it  were,  an  extension  of  the 
lenticular  or  quaquaversal  action  of  the  central  lens  by  assembling  the  light  around  its 
axis  in  the  form  of  concentric  hollow  cylinders.  (The  above  instruments  belong  to  the 
Board  of  Northern  Lights.) 

The  early  method  of  illuminating  lighthouses  was  by  coal  or  wood  fires  contained  in 
"  chauffers."  The  Isle  of  Man  light  was  of  this  kind  until  1816.  The  first  decided  im- 
provement was  made  by  Argand,  in  1784,  who  invented  a  lamp  with  a  circular  wick, 
the  flame  being  supplied  by  an  external  and  internal  current  of  air.  To  make  these 
lamps  more  effective  for  lighthouse  illumination,  and  prevent  the  ray  of  light  escaping 
on  all  sides,  a  reflector  was  afterward  added  ;  this  threw  the  light  forward  in  parallel 
rays  toward  such  points  of  the  horizon  as  would  be  useful  to  the  mariner.  Good  reflectors 
increase  the  luminous  effect  of  a  lamp  about  400  times;  this  is  the  "catoptric"  system 
of  lighting.  When  reflectors  are  used,  there  is  a  certain  quantity  of  light  lost^  and  the 
**  dioptric"  or  refracting  system,  invented  by  the  late  M.  Augustm  Fresnel,  is  designed 
to  obviate. this  effect  to  some  extent:  the  "catadioptric"  system  is  a  still  further  im- 
provement and  acts  both  by  refraction  and  reflexion.  Lights  of  the  first  order  have  aa 
interior  radius  or  focal  distance  of  36*22  inches,  and  are  lighted  by  a  lamp  of  four  con- 
centric wicks,  consuming  570  gallons  of  oil  per  annum. 

The  appearance  of  light  called  short  eclipses  has  hitherto  been  obtained  by  the  fol- 
lowing arrangement: — 

An  apparatus  for  a  fixed  light  being  provided,  composed  of  a  central  cylinder  and 
two  zones  of  catadioptric  rings  forming  a  cupola  and  lower  part^  a  certain  number  of 
lenses  are  arranged  at  equal  distances  from  each  other,  placed  upon  an  exterior  move- 
able frame  making  its  revolution  around  the  apparatus  in  a  given  period.  These  lenses, 
composed  of  vertical  prisms,  are  of  the  same  altitude  as  the  cylinder,  and  the  radius 
of  their  curves  is  in  opposite  directions  to  those  of  the  cylinder,  in  such  a  manner  that 
at  their  passage  they  converge  into  a  parallel  pencil  of  light,  all  the  divergent  rays  emit- 
ted horizontally  from  the  cylinder  producing  a  brilliant  effect^  like  that  obtained  by 
the  use  of  annular  lenses  at  the  revolving  lighthouses. 

The  first  improvement  exhibited  has  special  reference  to  the  light,  and  produces  a 
considerable  increase  in  its  power,  while  the  simplicity  of  the  optical  arrangements  is 
also  regarded.  It  consists,  firstly,  in  completely  dispensing  with  the  moveable  central 
cylindrical  lenses ;  secondly,  it  replaces  these  by  a  single  revolving  cylinder  composed 
of  four  annular  lenses  and  four  lenses  of  a  fixed  light  introduced  between  them;  but 
the  number  of  each  varying  according  to  the  succession  of  flashes  to  be  produced  in  the 
period  of  revolution. 

The  second  improvement,  of  which  already  some  applications  that  have  been  made 
serve  to  show  the  importance,  consists  in  a  new  method  of  arranging  the  revolving  parts, 
experience  having  shown  that  the  arrangements  at  present  in  use  are  not  very  faulty 
A  short  time  is  suflBcient  for  the  action  of  the  friction  rollers,  revolving  on  two  parallel 
planes,  to  produce  by  a  succession  of  cuttings  a  sufficiently  deep  groove  to  destroy  the 
regularity  of  the  rotatory  movement  To  obviate  this  great  inconvenience  the  friction 
rollers  are  so  placed  and  fitted,  on  an  iron  axis  with  regulating  screws  and  traversing 
between  two  bevelled  surfaces,  that  when  an  indentation  is  made  in  one  place  they  can 
be  adjusted  to  another  part  of  the  plates  which  is  not  so  worn. 

The  third  improvement  produces  the  result  of  an  increase  of  the  power  of  the  flashes 
in  revolving  lighthouse  apparatus  to  double  what  has  been  obtained  hitherto.  By 
means  of  lenses  of  vertical  prisms  placed  in  the  prolongation  of  the  central  annular 
lenses,  the  divergent  rays  emerging  from  the  catadioptric  zone  are  brought  into  a 
straight  line,  and  a  coincidence  of  the  three  lenses  is  obtained. 

The  whole  of  the  prisms,  lenses,  and  zones,  are  mounted  with  strength  and  simplicily, 
accurately  ground  and  polished  to  the  correct  curves  according  to  their  respective 
positions,  so  as  to  properly  develope  this  beautiful  system  of  Fresnel.  The  glass  of 
which  they  are  composed  is  of  the  clearest  crystal  color,  and  free  from  that  green  hue 
which  so  materially  reduces  the  power  of  the  lights  and  is  considered  objectionable  for 
apparatus  of  this  kind.  The  lamp  by  which  tlie  apparatus  is  to  be  lighted  consists 
of  a  concentric  burner  with  four  circular  wicks  attached  to  a  lamp  of  simple  construe 
tion,  the  oil  being  forced  up  to  the  burner  by  atmospheric  pressure  only,  so  that  ther« 
are  no  delicate  pumps  or  machinery  to  become  deranged. 


738 


STILL. 


iui; 


i  i 


Improved  lantern  and  revolvmg  apparatus  for  a  light  vessel.  The  principal  improTe- 
ment  consists  in  constructing  the  nnachinery  to  work  beneath  the  dect,  instead  of  In  tha 
lantern  as  formerly.  A  vertical  rod  working  in  metal  beariues  is  attached  to  the  masL 
with  a  large  gnn-metal  pinion  fixed  to  the  top  of  the  rod/Ttrfadphrto  whichT^. 
necessary  to  hoist  the  lantern,  wherein  a  train  of  cog-wheels  is  pL^to  co^ect  w  t" 
the  pinion  and  communicate  the  motion  obtained  therefrom  to  trtraversinA^^^^^^ 
tha  supporte  the  lamps  and  reflectors.  The  advantages  of  this  arrZeSTe  ?h^ 
the  lanterns  can  be  made  much  lighter,  the  rolling  of  thTvessel  caused  SX^reatrweght 
at  the  mast  head  is  greatly  diminished,  and  the  machinery  being  more  under  oTS 
and  better  protected   works  with  greater  regularity  and  precision. 

An  idea  of  the  utility  of  these  improvements  may  be  gained  by  reflecting  thnf  th* 
TtlTmv  r  %"'" V'  light-vessels  a're  placed  are  at^all  tLes  diS^ult  oft^^^^^^^^ 
stormy  weather,  when  accidents  are  most  likely  to  occur,  quite  unapproachable ;  so  that 

t^Ie  apprSt'd. "''  ''''"'"°  ^''''  '^'"^^^  ^'^  "^^^"^^  '^  de^Lgement  is  greatly 

aimh^rJn.t"''  t"  ^^r^'^S^  <^«"^«^  fr«™  the  novel  construction  of  the  lamps  and 
gimbal  work,  which,  by  a  movement  exactly  coinciding  with  the  motion  of  the  vessel 
causes  a  perfect  level  to  be  always  maintained,  and  enfures  the  pTopTflow  of  oS 
the  burners,  however  irregular  that  motion  ma^  be.  This  improvement  is  not  of  so  re- 
cent an  introduction  as  the  former,  but  when  It  was  first  invented  by  one  of  the  ex- 
.wiriL  K^'^^^-n  a""  '^°]P^^^  revolution  in  the  apparatus  for  floating  lights,  and  en- 

^ut^^    ^.K^'^"^  ^"^r.^  '^'VP^  ^'^^  parabolic  reflectors,  to  be  used  inst^d  of  the 
old  lamps  with  smoky  flat  wicks. 

hv^h?^^  (-^^^^ftic.  Fr.  -Blase,  Germ.),  is  a  chemical  apparatus,  for  vaporizing  liquid, 
by  heat  in  one  part  called  the  cucurbit,  and  condensing  the  vapors  into  liquids  in  anotheJ 
jmrt,  called  the  refrigeratory ;  the  general  purpose  of  both  combined  being  to  separate 
the  more  volatile  fluid  particles  from  the  less  volatile.  In  its  simpleslTrm,  it  consTsi; 
InHnlTh'"/  ^  'T'T'  "^  "^  ^  r^'-'^^/P^d  matrass  and  a  capital,  furnis'hed  whh  a 
Jianting  tube  for  conducting  away  the  condensed  vapors  in  drops:  wheice  the  term  stiU 
from  the  Latin  verb  stillare  to  drop.  Its  chief  employment  in  this  count.^  being  to  elim! 
mate  alcohol,  of  greater  or  less  strength,  from  fermented  wash,  I  shall  devote  this  article 
to  a  description  of  the  stills  best  adapted  to  the  manufacture  of  British  spirits  riferrini 
to  chemical  authors*  for  those  fitted  for  peculiar  objects  reierring 

In  respect  of  rapjdity  and  extent  of  work,  stills  had  Attained  to  an  extraordinary  pitcli 
of  perfection  in  Scotland  about  thirty  years  ago,  when  legislative  wisdom  thoueht  fit  to 
levy  the  spirits  duty,  per  annum,  from  each  distiller,  according  to  the  capacity  of  hii 
still.  It  having  been  shown,  m  a  report  presented  to  the  House  of  Commons  in  1799 
that  an  SO-gallon  still  could  be  worked  ofl-in  eight  minutes,  this  fact  was  made  the  basis' 
of  a  new  fiscal  law  on  the  supposition  that  the  maximum  of  velocity  had  been  reached 
But,  instigated  by  the  hopes  of  enormous  gains  at  the  expense  of  the  revenue,  the  distill- 
ers soon  contrived  to  do  the  same  thing  in  three  minutes,  by  means  of  broad-bottomed 
shal  ow  stills,  with  stirring-chains,  and  lofty  capitals.  In  the  year  1815,  that  preposter- 
ous law,  which  encouraged  fraud  and  deteriorated  the  manufacture,  was  repealed  The 
whiskey  duties  having  been  since  levied,  independently  of  the  capacity  of  the  still,  upon 
the  quantity  produced,  such  rapid  operations  have  been  abandoned,  and  processes  of  econ- 
omy in  fuel,  and  purity  m  product,  have  been  sought  after. 

One  of  the  greatest  improvements  in  modern  distilleries,  is  completing  the  analysis 
rS?"  l/^r     ?'  '•''^  operation.     Chemists  had  been  long  familiar  with  the  contrivance 
of  Woulfe,  for  impregnating  with  gaseous  matter,  water  contained  in  a  range  of  bottles  • 
but  they  had  not  thought  of  applying  that  plan  to  distillation,  when  Edouard  Adam' 
an  illiterate  workman  of  Montpellier,  after  hearing  accidentally  a  chemical  lecture 
upon   that   apparatus,  bethought   himself  of  converting  it   into  a   still      He   caused 
the  boiling-hot  vapors  to  chase  the  spirits  successively  out  of  one  bottle'  into  another 
so  as  to  obtain  m  the  successive  vessels  alcohol  of  any  desired  strength  and  purity,  «  oJ 
am  and  the  same  heat  "He  obtained  a  patent  for  this  invention  in  1801,  and  was  soon 
afterwards  enabled,  by  his  success  on  the  small  scale,  to  set  up  in  his  native  city  a  mag- 
mficent  distillery  which  excited  the  admiration  of  all  the  practical  chemists  of  thft 
day     In  November,  1805,  he  obtained  a  certificate  of  certain  improvements  for  ex- 
tractmg  from  wine,  at  one  process,  the  whole  of  its  alcohol.     Adam  was  so  ovenoyed. 
after  making  his  first  experiments,  that  he  ran  about  the  streets  of  Montpellier,  telling 
everybody  of  the  surprising  results  of  his  invention.     Several  competitors  soon  entered 
the  lists  with  him,  especially  Solimani,  professor  of  chemistry  in  that  city,  and  Isaae 

♦  The  treatises  of  LeNormand  and  Dubruiifaut  may  also  be  consulted.    The  French  stills  are  in  nn»tml 
SiTof  ^S  '  *"**  ""^  """^^  ^'^"  ""^  P^"""^"'  "  »°  ^  «nfit  for  filing  Se  glSSSS 


STILL. 


739 


Berard,  distiller  in  the  department  of  Gard ;  who,  having  contrived  ether  forms  of  cos 
tinuous  stills,  divided  the  profits  with  the  first  inventor. 

The  principles  of  spirituous  distillation  may  be  stated  as  follows  :— The  boiling  point 
oC'  alcohol  varies  with  its  density  or  strength,  in  conformity  with  the  numbers  in  the  fol- 
lowing  table: — 


Speafic  grtLYity. 

Boiling^  point,  by  Fahrenheit's 
scale. 

Specific  gfravity. 

Boiling  point,  bj  Fahr«nheit% 
male. 

0-7939 

168-5® 

0-8875 

181-0" 

0-8034 

168-0 

0-8631 

1830 

0-8118 

168-5 

0-8765 

187-0 

0-8194 

1690 

0-8892 

190-0 

0-8265 

172-5 

0-9013 

194-0 

0-8332 

173-5 

0-9126 

197-0 

0-8397 

175-0 

0-9234 

199-0 

0-8458 

177-0 

0-9335 

201-0 

0-8518 

179-0 

See  also  the  table  under  Alcohol,  page  22. 

Hence,  the  lower  the  temperature  of  the  spirituous  vapor  whsch  enters  the  refti- 
geratory  apparatus,  the  stronger  and  purer  will  the  condensed  spirit  be ;  because  the 
oflensive  oils,  which  are  present  in  the  wash  or  wine,  are  less  volatile  than  alcohol,  and 
are  brought  over  chiefly  with  the  aqueous  vapor.  A  perfect  still  should,  therefore,  consist 
of  three  distinct  members ;  first,  the  cucurbit,  or  kettle ;  second,  the  rectifier,  for  inter- 
cepting more  or  less  of  the  watery  and  oily  particles ;  and  third,  the  refrigerator,  or  conden- 
ser of  the  alcoholic  vapors. 

These  principles  are  illustrated  in  the  construction  of  the  still  represented  in^g».  1365, 
1366,  1367,  1368,  1369  ;  in  which  the  resources  of  the  most  refined  French  stills  are 
combined  with  a  simplicity  and  solidity  suited  to  the  grain  distilleries  of  the  United 
Kingdom.  Three  principal  objects  are  obtained  by  the  arrangement  here  shown;  first, 
the  extraction  from  fermented  wort  or  wine,  at  one  operation,  of  a  spirit  of  any  desired 
cleanness  and  strength  ;  second,  great  economy  of  time,  labor,  and  fuel ;  third,  freedom 
from  all  danger  of  blowing  up  or  boiling  over,  by  mismanaged  firing.  When  a  com- 
bination of  water,  alcohol,  and  essential  oil,  in  the  state  of  vapor,  is  passed  upwards 
through  a  series  of  winding  passages,  maintained  at  a  determinate  degree  of  heat, 
between  170°  and  180°,  the  alcohol  alone,  in  any  notable  proportion,  will  retain  the 
elastic  form,  and  will  proceed  onwards  into  the  refrigeratory  tube,  in  which  the  said 
passages  terminate ;  while  the  water  and  the  oil  will  be  in  a  great  measure  condensed, 
arrested,  and  thrown  back  into  the  body  of  the  still,  to  be  discharged  with  the  efiete 
residuum. 

The  system  of  passages  or  channels,  represented  in^g.  1366,  is  so  contrived  as  to  bring 
the  mingled  vapors  which  rise  from  the  alembic  a,  into  ample  and  intimate  contact  with 
metallic  surfaces,  maintained,  in  a  water-bath,  at  a  temperature  self-regulated  by  a  heat- 
governor.     See  Thermostat. 

The  neck  of  the  alembic  tapers  upwards,  as  shown  at  6,  fig.  1365  ;  and  at  c,fig,  1366, 
it  enters  the  bottom,  or  ingress  vestibule,  of  the  rectifier  c,/.  /is  its  top  or  egress 
vestibule,  which  communicates  with  the  bottom  one  by  parallel  cases  or  rectangular 
channels  d,  <£,  d,  of  which  the  width  is  small,  compared  with  the  length  and  height. 
These  cases  are  open  at  top  and  bottom,  where  they  are  soldered  or  rivet«l  into  a  genenu 
frame  within  the  cavity,  enclosed  by  the  two  covers  /,  c,  which  are  secured  round  their 
edges  e,  e,  e,  e,  with  bolts  and  packing.  Each  case  is  occupied  with  a  numerous  series 
of  shelves  or  trays,  placed  at  small  distances  over  each  other,  in  a  horizontal  or  slightly 
inclined  position,  of  which  a  side  view  is  given  in  fig.  1367,  and  cross  sections  at  d,  d,  J^ 
fig.  1366.  Each  shelf  is  turned  up  a  little  at  the  two  edges,  and  at  one  end,  but  slop^d 
down  at  the  other  end,  that  the  liquor  admitted  at  the  top  may  be  made  to  flow  slowly 
backwards  and  forwards  in  its  descent  through  the  system  of  shelves  or  trays,  as  in- 
dicated by  the  darts  and  spouts  in  fig.  1367.  The  shelves  of  each  case  are  framed 
together  by  two  or  more  vertical  metallic  rods,  which  pass  down  through  them,  and  are 
fixed  to  each  shelf  by  solder,  or  by  screw-nuts.  By  this  means,  if  the  cover/,  be  removed, 
the  sets  of  shelves  may  be  readily  lifted  out  of  the  cases  and  cleaned ;  for  which  reason 
they  are  called  moveabU. 

The  intervals  i,  i,  i,fig.  1366,  between  the  cases,  are  left  for  the  free  circulation  of  the 
water  contained  in  the  bath-vessel  g,  g ;  these  intervals  being  considerably  narrower  tha* 
the  cases.  • 

Fig.  1368  represents  in  plan  the  surface  of  the  rectifying  cistern,  shown  in  two 
different  sections  in^ig*.  1366  and  1367.     h,k,fig$,  1366  and  1368, is  the  heat-governor. 


740 


STILL. 


STILL. 


741 


P' 


lii.  I 


iii  i 


it  i 


shaped  somewhat  like  a  pair  of  tongs.     Each  leg  is  a  compound  bar,  consisting  of  • 
flat  bar  or  ruler  of  steel  and  one  of  bmss  alloy,  riveted  facewise  together  having  I?e5 

-h?.rP '"?  ^T-    ^^"  ^^"^''  ^'  ^>  "^  J«'"^d  '^  '^'  fr««  ends  of  tSese  coCun^^  bar^ 
Which,  receding  by  increase  and  approaching  by  decrease  of  temperature,  act  by  a  ?ey«  2 


the  stopcock  /,  fixed  to  the  pipe  of  a  cold-water  back,  and  are  so  adjusted  by  a  screw-nut. 
that  whenever  the  water  in  the  bath  vessel  g,  g,  rises  above  the  desired  temperature! 
cold  water  will  be  admitted,  through  the  stopcock  /,  and  pipe  n,  into  the  bottom  of  the 
cistern,  and  will  displace  the  over-heated  water  by  the  overflow-pipe  m.  Thus  a  perfect 
equihbnum  of  caloric  may  be  maintained,  and  alcoholic  vapor  of  correspondent  uniformity 
transmitted  to  the  refrigeratory.  ' 

if'ig.  1369  is  the  cold  condenser,  of  similar  construction  to  the  rectifier, /ig.  1366;  only 
the  water  cells  should  be  here  larger  in  proportion  to  the  vapor  channels  d,  d.  This 
refrigeratory  system  will  be  found  very  powerful,  and  it  presents  the  great  advantage  of 
perniitting  its  intenor  to  be  readily  inspected  and  cleansed.  It  is  best  made  of  laminated 
tin,  hardened  with  a  little  copper  alloy. 

The  mode  of  working  the  preceding  apparatus  will  be  understood  by  the  following 
instructions.  Into  the  alembic,  a,  let  as  much  fermented  liquor  be  admitted  as  will  pr(^ 
tect  Its  bottom  from  being  injured  by  the  fire,  reserving  the  main  body  in  the  charging- 
back.  Whenever  the  ebullition  in  the  alembic  has  raised  the  temperature  of  the  water- 
Wr/'  ^\^  the  desired  pitch,  whether  that  be  170°,  175o,  or  180°,  the  thermostatic 
instrument  is  to  be  adjusted  by  its  screw-nut,  and  then  the  communication  with  the 
chargmg-back  is  to  be  opened  by  moving  the  index  of  the  stopcock  o,  over  a  proper 
portion  of  its  quadrantal  arch.  The  wash  will  now  descend  in  a  slender  equable 
stream,  through  the  pipe  o,  /,  thence  spread  into  the  horizontal  tube  p,  p,  and  issue 
trom  the  orifices  of  distribution,  as  seen  in  the  figure,  into  the  respective  flat  trays  or 
spouts.  1  he  manner  of  its  progress  is  seen  for  one  set  of  trays,  in  fig.  1059.  The  direc 
tion  of  the  stream  in  each  shelf  is  evidently  the  reverse  of  that  in  the  shelf  above  and 
wi  hbiV  ^"^»^-"P  end  of  one  shelf  corresponding  to  the  discharge  slope  of  iU 

By  diffusmg  the  cool  wash  or  wine  in  a  thin  film  over  such  an  ample  range  of  sur- 
faces, the  constant  tendency  of  the  bath  to  exceed  the  proper  limit  of  temperature  is 
counteracted  to  the  utmost,  without  waste  of  time  or  fuel;  for  the  wash  itself,  in 
transitu,  becomes  boilmg-hot,  and  experiences  a  powerful  steam  distillation.  By  this 
arrangement  a  very  moderate  influx  of  cold  water,  through  the  thermostatic  stopcock, 
suffices  to  temper  the  bathj  such  an  extensive  vaporization  of  the  wash  producing  a  far 
more  powerful  refrigerant  influence  than  its  simple  heating  to  ebullition.  It  deserves 
to  be  remarked;  that  the  maximum  distillatory  effect,  or  the  bringing  over  the  greatest 
quantity  of  pure  spintsm  the  least  time,  and  with  the  least  labor  and  fuel,  is  here 
accomplished  without  the  least  steam  pressure  in  the  alembic ;  for  the  passages  are 


ill  pervious  to  the  vapor;  whereas,  in  almost  every  wash-still  heretofore  contrived  fbr 
similar  purposes,  the  spirituous  vapors  must  force  their  way  through  successive  layert 
of  liquid,  the  total  pressure  produced  by  which  causes  undue  elevation  of  temperature, 
and  obstruction  to  the  process.  Whatever  supplementary  refrigeration  of  the  vapors  in 
their  passage  through  the  bath  may  be  deemed  proper,  wUl  be  administered  by  the  ther- 
mostatic regulator. 

Towards  the  end  of  the  process,  after  all  the  wasli  has  entered  the  alembic,  it  may  be 
sometimes  desirable,  for  the  sake  of  despatch,  to  modify  the  thermostat,  by  its  adjusting- 
screw,  so  that  the  bath  may  take  a  higher  temperature,  and  allow  the  residuary  feints  to 
run  rapidly  over,  into  a  separate  cistern.  This  weak  fluid  may  be  pumped  back  into  the 
alembic,  as  the  preliminary  charge  of  a  fresh  operation. 

The  above  plan  of  a  water-bath  regulated  by  the  thermostat,  may  be  used  simply  as 


a  rectifying  cistern,  without  transmitting  the  spirit  or  wash  down  through  it.  The 
series  of  shelves  will  cause  the  vapors  from  the  still  to  impinge  against  a  most  ex- 
tensive system  of  metallic  surfaces,  maintained  at  a  steady  temperature,  whereby  their 
watery  and  crude  constituents  will  be  condensed  and  thrown  back,  while  their  fine 
alcoholic  particles  will  proceed  forwards  to  the  refrigeratory.  Any  ordinary  still  may 
be  readily  converted  into  this  self-rectifying  form,  by  merely  interposing  the  cistern, 
fig.  1366,  between  the  alembic  and  the  worm-tub.  The  leading  novelty  of  the  present 
invention  is  the  moveable  system  of  shelves  or  trays,  enclosed  in  metallic  cases,  separated 
by  water,  combined  with  the  thermostatic  regulator.  By  this  combination,  any  quality 
of  spii'its  may  be  procured  at  one  step  from  wash  or  wine,  by  an  apparatus,  simple,  strong, 
and  easily  kept  in  order. 

The  empyreumatic  taint  which  spirits  are  apt  to  contract  from  the  action  of  the  naked 
fire  on  the  bottom  of  the  still,  may  be  entirely  prevented  by  the  use  of  a  bath  of  potash 
ley,  p,  py  fig.  1365 ;  for  thus  a  safe  and  effectual  range  of  temperature,  of  300°  F.,  may 
be  conveniently  obtained.    The  still  may  also  be  used  without  the  bath  vessel. 

Mr.  D.  T.  Shears,  of  Southwark,  obtained  a  patent  in  March,  1830,  for  certain  im- 
provements and  additions  to  stills,  which  are  ingenious.  They  are  founded  upon  a 
previous  patent,  granted  to  Joseph  Corty,  in  1818 ;  a  section  of  whose  contrivance  is 
•hown  in  fig,  1370,  consisting  of  a  first  still  a,  a  second  still  6,  a  connecting  tube  c,  from 

the  one  end  to  the  other,  and  the  tube  d,  which  leads 
1370  from  the  second  still-head  down  through  the  bent  tube 

/     f'TU^f****^        *»  *'  '®  ^^*  lower  part  of  the  condensing  apparatus. 

'  ^  The  original  improvements  described  under  Corty's 

patent,  consisted  further,  in  placing  boxes  /,/,/>  of  the 

condensing  apparatus  in 
horizontal  positions,  and 
at  a  distance  from  each 
other,  in  order  that  the 
vapor  might  ascend 
through  them,  for  the 
purpose  of  discharging 
the  spirit  by  the  top  tube 
g,  and  pipe  /i,  into  the 
worm,  in  a  highly  recti- 
fied or  concentrated 
state.  In  each  of  the 
boxes/,  there  is  a  convex 
plate  or  inverted  dish  t, 
t,  i,  and  the  vapor  ia 
rising  from  the  tube  4^ 
strikes  against  the  con- 
cave or  under  part  of 
the  first  dish,  and  then 
escapes  round  its  edges, 
and  over  its  convex  sur- 
face, to  the  under  part 
of  the  second  dish,  and 
so  on   to   the   top,  the 

eondeased  part  of  the  vapor  flowing  down  again  into  the  still,  and  the  spirit  passing  oflT 
by  the  pipe  h,  at  top ;  and  as  the  process  of  condensation  will  be  assisted  by  cooling  the 
Tapor  as  it  rises,  cold  water  is  made  to  flow  over  the  tops  of  the  boxes  /,  from  a  cock  k, 
and  through  small  channels  or  tubes  on  the  sides  of  the  boxes,  and  is  ultimately  discharged 
by  the  pipe  I,  at  bottom. 

Fig.  1371  represents  a  peculiarly  shaped  tube  a,  through  which  the  spirit  is  described 
as  passing  after  leaving  the  end  of  the  worm  at  6,  which  tube  is  open  to  the  atmospheric 


742 


STILL. 


STILL. 


743 


# 


Now  the  improvements  claimed  under  the  present  oatent  are  PTh;K;»«^  ;„  ^^.  iiro 
1373  and  1374  Fig.  1372.  represents  the 'externaftpearincT'o^a  stUl^t^he  h^S 
of  Str.X  l^TirZT'^''  guard  against  over-boiJing  by  any  mislnagemenl 
?  J^  .if'^*^:i  ^i^j^®  same,  partly  m  section.  On  the  top  of  the  still-head  is 
formed  the  first^escribed  rectifying  apparatus,  or  series  of  condensing  £^esTh" 
vapor  from  the  body  of  the  still  filling  the  head,  meets  with  the  first  check  fr^m  !he  Sh 
or  lower  vessel  i,  and  aUer  passing  under  its  edges,  ascends  and  strikes  SainTt^helowe- 

^pl  tZ  "  ''"''  ''  '"'  ''  "*  '^  it  ultimately  leal;  tLft""tadbyT^^^^ 

This  part  of  the  apparatus  is  slightly  altered  from  the  former,  by  the  substitution  ol 
hollow  convex  vessels,  instead  of  the  inverted  dishes  before  described,  whicrveselsLv 
nms  descending  from  their  under  surfaces,  for  the  purpose  of  r^tainfng  the  va^r 
The  cold  water,  which,  as  above  described,  flowed  over  the  tops  of  the  bofes/  forThe 
purpose  of  cooling  them,  now  flows  also  through  the  hollow  convex  vessels  t^^j^'thin  the 
boxes,  and  by  that  means  greatly  assists  the  refrigerating  process^by  which  thTaqueiSs 
?^'^\^^'^Y^l^l^remore  readily  condensed,  and  made  to  fall  do^na^d  flow  back  a^L^ 

Lthttrof^i^^riii^^'"^ '''  ''''^^-  ^-''  ^-  «^-  -p  -  ^'^  wr.!  inVi:;? 

rntfthesUlV  ^!|f,'^^'.^^^--^^  in  which  the  wash  is  placed  ^ei^ouITntr^^^^^^^^^ 
Sit  h!  K  ;  7^^  P'P^  '"^  "  *^^'^'^  "''""^  *"  *^^  ^°we^  part  of  the  vessel  «,  in  order 
heat  hv  ^nni'**  "^f^''  may  communicate  its  caloric  to  the  wash,  instead  VlUUThc 
heat  by  allowing  the  water  to  flow  away.  After  the  heated  water  has  made  several 
turns  round  the  wash  heater,  it  passes  out  at  the  curved  pipe  o  which  iTbentunh^ 
order  to  keep  the  coils  of  the  pipe  within  always  full  of  water  ^' 

the  horwater'?n,nf  1  ^'f  "?  ^^^  described  the  patentee  pr'oposes  sometimes  to  pass 
w!ch  .  T   t    Ta  ^  «*'*'P'>«';i»  a  tub  or  wooden  vessel,  as  at  n,  in  fig.  1369,  in  which  the 

;;rn\^''htrx"ra«i;L^„"''^'  ^''"  •"■""=  --' «»"  *»  -p-'^i  '^»'»  ""=  -owe: 

The  swan-neck  h,  fig,  1372  and  1373,  which  leads  from  Ihe  head  of  the  still  conduct. 

spirit  passes  to  the  worm  tub,  and  being  finally  con-  ^ — T^       ^t^ 

densed,  is  passed  through  a  safety  tube,  as  (fig.  1366)  /         \y\  ^u    ^372 

before  described,  and  by  the  funnel  is  conducted  into  ^     ^"''^ 
the  cask  below. 


Should  any  spirit  nse  m  the  wash-heater  during  the  above  operation,  it  will  be  carried 
down  to  the  worm  by  the  neck  ;,,  and  coiled  pipe,  and  discharged  at  its  lower  end^o^k 
may  be  passed  into  the  still-head,  as  shown  in^g!  1370.  *    '  ** 

Coffejf^i  Still  This  ingenious,  ori^ginal  and  powerful  apparatus  for  distilling  spirits 
from  fermented  worts  or  wash  of  all  kinds,  is,  after  many^^struggles  with  the  illiberS 
prejudices  of  the  Excise  now  universally  recognized  as  the  besfraost  economica  and 
surest  m  a  revenue  point  of  view,  of  all  the  contrivances  of  eliminating  the  alcohil  in 
the  purest  state,  and  of  any  desired  strength,  at  one  operation.  Its  outer  form  ind 
internal  structure  differ  essentially  from  those  of  all  the  old  stills,  though  it  possesses 
some  of  the  good  principles  of  Derosnes,  m  continuity  of  action,  and  in  causing  a  currenl 


of  spirituous  vapor  to  ascend,  and  a  current  of  wash  deprived  of  its  alcohol  to  descend 
in  one  system  of  continuous  cells.  Its  main  structure  consists  of  a  series  of  wooden 
planks,  6  or  6  inches  thick,  fixed  over  one  another,  the  joints  being  covered,  or  the 
whole  being  lined  with  sheet  copper;  so  that  the  apparatus  resembles  a  great  ches^ 
to  which  is  attached  the  induction  pipe  of  a  steam  boiler,  as  the  active  principle  of 

the  whole. 

The  essential  apparatus  consists  of  three  main  parts;  the  wash  collector  a,  a,  a,  and 
the  two  rectangular  columns  or  uprights. 

The  front  column  d,  d,  d,  or  the  analyser,  is  for  rectifying  the  wash,  the  other  column 
is  intended  for  warming  the  wash ;  the  under  part  f,  f,  f,  of  the  forewarraer  serves  as 
ft  dephlegmator  and  for  the  rectification  of  the  feints;  the  upper  part  e,  b,  Ki  serves  to 
condense  the  strong  spirituous  vapor. 

1376 


The  wash  collector  a,  is  divided  into  two  compartments  b  and  o,  by  means  of  the 
copper  plate  c  c;  this  plate  c  c,  is  pierced  with  a  drainer,  with  a  number  of  small  holes, 
and  is  provided  also  with  a  t  shaped  valve  o  o  o.  The  wash  rectifier  d  is  divided  by 
the  plates  r,  r,  of  a  like  drainer  construction  into  12  chambers,  and  the  feint  rectifier 
F  f,  into  10  chambers  by  similar  plates  s,  «,  «.  These  orifices  are  so  narrow  as  to  allow 
the  passage  of  the  rising  vapor,  but  to  prevent  the  downward  passage  of  the  liquid 
resting  on  the  plates,  which  passes  downwards  through  the  adjunct  tubes,  viz.,  d,  into 
the  wash  collector  b,  v,  into  the  rectifier  d,  and  likewise  into  the  dephlegmator  f,  pass- 
ing from  each  upper  into  the  next  under  chamber.  When  the  steam  pressure  is  too 
strong,  the  valves  o,  o,  give  it  vent 

When  the  apparatus  is  in  action,  a  continuous  stream  of  wash  is  raised  out  of  o,  by 
means  of  the  pump  k,  into  the  tube  t,  which  feeds  the  still.  This  current  must  be  re- 
gulated very  nicely,  so  as  just  to  feed  the  tube  »,  allowing  the  excess  to  return  through 
the  stop-cock  ar,  and  the  tube  I,  into  the  wash-cistern  a  The  tube  t  enters  into  the 
uppermost  partition  of  e,  forming  7  zig-zag  bendings  in  this  space,  and  through  f,  and 
then  mounts  upwards  from  that  chamber  into  the  top  chamber  of  d.  Thence  the  wash 
flows  down  from  chamber  to  chamber,  and  arrives  through  d  into  c,  and  finally  in  a 
similar  way  into  b,  where  it  is  fully  deprived  of  spirit,  and  is  from  time  to  time  run  off 
through  t.  It  is  necessary  throughout  that  the  wash  in  this  passage  into  d  and  b  should 
stand  about  an  inch  high  upon  each  plate  r  r,  for  which  purpose  the  adjunct  tubes  • 


744 


STILL. 


STILL. 


should  stand  an  inch  aboye  the  plate,  and  thus  give  the  vapor  no  indirect  passage,  aa 
the  under  end  of  each  tube  v  dips  into  a  shallow  cup,  and  is  thus  shut  in  by  the  wash 
remaining  in  it  The  tube  d,  which  leads  the  wash  from  the  plate  c  c  into  c,  serves  a 
Jike  purpose.  As  soon  as  it  has  risen  up  in  it  to  the  upper  orifice  of  the  glass  tube  y. 
the  valve  6  is  to  be  opened,  to  allow  it  to  flow  off  into  b  through  the  tube  6 

Here  into  b  the  very  hot  and  nearly  spent  wash  comes  into  contact  with'  the  steam 
issuing  fi-om  the  steam  boiler  through  tlie  steam  tube  a,  a.  It  rushes  through  it.  and 
carries  <>ff  from  it  the  spirit  through  the  small  orifices  of  the  plate  c,  expands  thus  into 
the  whole  breadth  of  this  chamber  through  the  wash  standing  in  it,  and  deprives  this  at 
once  of  every  trace  of  spirit^  then  collects  over  the  fluid,  and  enters  through  the  connec- 
tion tube  c,  into  the  undermost  chamber  of  d,  and  thence  into  the  following  in  succession 
always  through  the  orifices  of  the  plate  r  r.  Whilst  the  steam  meets  the  wash  in  even? 
•hamber  and  becomes  more  spirituous  the  higher  it  mounts,  it  at  the  same  time  becomes 
cooler,  and  deposites  the  watery  part,  absorbing  more  alcohol,  so  that  after  this  compli- 
cated  rectification  it  passes  on  through  the  tube  m,  wi,  into  the  lowest  chamber  of  the 
lorewarmer  r  It  here  pursues  a  like  path  upwards  through  the  plates  »,  «,  where  the 
feints  are  at  the  same  time  rectified  by  the  dephlegmation  of  the  vapor.  The  steam 
flows  through  the  different  junction  tubes  into  f,  and  its  subdivisions,  whereby  (as  the 
wash  in  D)  forms  upon  each  plate  a  layer  an  inch  thick  to  be  penetrated  by  tlie  steam. 
Ihe  remainder  passes  out  of  the  undermost  plate  through  the  tube  g  g,  into  g,  where  it 
18  carried  on  by  the  pump  with  fresh  wash  into  circulation  in  the  apparatus. 

Ihe  alcoholic  vapors  reaches  now  b.  The  plate  which  separates  b  and  f  is  not  per- 
forated  ;  it  lets  the  vapor  merely  pass  through  the  short  and  wide  junction  tube  w,  into 
tne  condenser  e,  where  in  like  manner  the  non-perforated  plates  w,  w,  compel  it  to  fol- 
low  the  zig-zag  bendings  of  i,  i,  so  as  to  complete  its  condensation  and  the  heating  of 
llie  wash  in  r.  The  completely  condensed  vapor  is  collected  on  the  bottom  of  e,  and 
18  conducted  out  of  the  cup  of  the  junction  tube  there,  which  is  larger)  through  the 
annexed  tube  sideways  at  p,  into  the  refrigerator,  (not  shown  in  the  figure! 

1  shall  conclude  this  article  with  a  description  of  two  stills,  the  first  of  which  is  com- 
monly employed  by  the  chemists  in  Berlin  for  rectifying  alcohol,     a,  is  the  ash-pit;  b. 


the  fireplace ;  c,  c,  the  flues,  which  go  spirally  round  the  sides  of  the  cucurbit  </•  e  the 
capital,  made  of  block  tin,  and  furnished  with  a  brass  edge,  which  fits  tight  to  a  corre- 
sponding edge  on  the  mouth  of  d;  f,f,  the  slanting  pipes  of  the  capital ;%.  the  oval  re- 
frigeratorv,  made  of  copper ;  A,  the  water-gauge  glass  tube ;  t,  a  stopcock  for  emptying 
the  vessel;  ^,  do,  for  drawing  off  the  hot  water  from  the  surface;  /,  tube  for  the 
■"f ^/ .?  ^""l^  ^***^-  ^  ^"""^^^  cylinder  of  tin  is  placed  in  the  refrigeratory  of 
which  the  outer  one  m,  m,  stands  upon  three  feet,  and  is  furnished  with  a  dischirge 
pipe  n.  Ihe  inner  one  o,  o,  which  is  open  above,  receives  cold  water  through  the 
pipe/),  and  lets  the  warm  water  flow  off  through  the  short  tube  q,  into  the  refricrera- 
lory.  In  the  narrow  space  between  the  two  cylinders,  the  vapors  preceding  from 
tlie  capital  are  condensed,  and  pass  off  in  the  liquid  state  through  i  The  refrige- 
ratory  is  made  oval,  m  order  to  receive  two  condensers  alongside  of  each  other  in  the 
hne^of  the  longer  axis;  though  only  one,  and  that  in  the  middle,  is  represented  in  the 

The  continuous  system  of  distillation  has  been  carried  in  Prance  to  a  great  pitch 
of  perfection,  by  the  mgenmty  chiefly  of  M.  Cellier  Blumenthal,  and  M.  cl  Derwne. 
J^g,  1377  18  a  general  view  of  their  apparatus ;  a  and  b  are  boilers  or  alembics  encased 


745 

in  brickwork,   and  receiving 
directly  the  action  of  the  flame 
playing  beneath  thera ;  in  the 
copper.  A,  the  vinasse,  or  spent 
wine,  is  finally  exhausted  of 
all  its  alcohol,     c  is  the  column 
of  distillation ;  d,  the  column 
of  rectification ;   e,  the  wine- 
heating  condenser;    f,  the  re- 
frigerator;    G,    a  vessel    sup- 
plying vinasse  to  the  cooler  f, 
and  feeding  itself  at  the  same 
time  by  means  of  a  ball  stop- 
cock placed  in  the  vessel  h; 
H,  reservoir  of  vinasse ;  i,  tube 
oif  communication  conducting 
the    alcoholic  vapors  of   the 
rectifying  column,  d,  up  into 
the  flat  worm   of   the   wine- 
heater,  e;  a,  stopcock  of  dis- 
charge of  the  alembic,  a  ;  when 
the    operation    goes    on,   the 
spent    vinasse    runs   off   con- 
tinually    by    the     stop-cock; 
6,  a  glass  tube  to  show  the 
height  of  the  liquor  in  a  ;   c,  a 
safety-valve;    a,   a    stop-cock 
for  passing  the  vinasse  from 
the  alembic,  b,  into  the  bottom 
of  the  alembic,  a;    c,  a  tube 
to  lead  the  alcoholic  vapors, 
generated  in  a,  into  the  bottom 
of  B,  which  vapors,  in  passing 
through  the  liquor  in  b,  heat 
it,  and  are  partially  condensed ; 
/,  glass  tube  to  mark  the  level 
of  the  liquor  in  b;  g,  and  or,  level 
indicators;  h,  pipe  condfucting 
the  vinasse  from  the  lower  part  of  the  wine-heater,  e,  upon  the  uppermost  of  the  series 
of  horizontal  discs,  mounted  within  the  column  of  distillation ;  i,  a  stop-cock  for  empty- 
ing the  wine-heater  at  the  end  of  an  operation ;  I,  I,  two  tubes  fitted  to  the  wine-heater, 
X,  of  which  the  first  descends  into  the  last  compartment  of  the  rectifier,  whence  it  rises 
to  the  fifth ;  and  the  second  tube  descends  to  the  third  compartment,  whence  it  rises  above 
the  second.     At  the  curvature  of  each  of  these  two  tubes  a  stopcock,  I,  and  k,  is  placed 
on  them,  for  drawing  at  pleasure  a  sample  of  the  liquor  returned  to  the  rectifier;  wi,  n, 
and  o,  are  tubes  communicating  on  one  side  with  the  slanting  tube,  j5,  and  on  the  other 
with  the  tube,  /.     These  three  communications  serve  to  furnish  a  spirit  of  greater  or 
less  strength.    Thus  if  it  be  wished  to  obtain  a  very  strong  spirit,  the  alcoholic  vapors 
which  condense  in  the  worm  enclosed  in  e,  are  all  to  be  led  back  into  the  rectifier,  d, 
to  effect  which  purpose  it  is  requisite  merely  to  open  the  stop-cocks,  n  and  o ;  again, 
weaker  spirits  may  be  had  by  closing  the  stop-cock,  o,  and  still  weaker  by  closing  the 
stop-cock,  w;  for  in  this  case,  the  alcoholic  vapors  condensed  in  the  worm  within  ^ 
will  flow  off  into  the  worm  within  the  upright  cooler,  f,  and  will  get  mixed  with  the 
richer  vapors  condensed  in  this  refrigeratory.     The  interior  of  the  column,  c,  contains 
a  series  of  moveable  concave  scale  pans  (like  those  of  balances),  with  spaces  between, 
each  alternate  pan  having  the  convex  side  turned  reversely  of  the  preceding  one,  for  the 
purpose  of  prolonging  the  cascade  descent  of  the  vinasse  through  c,  and  exposing  it  more 
to  the  heating  action  of  the  ascending  vapors ;  the  edges  of  these  pans  are,  moreover, 
furnished  with  projecting  spiculfie  of  copper  wires,  to  lead  off  the  liquor  from  their 
surfaces  in  a  fine  shower.     The  interior  of  the  rectifier  column,  d,  is  mounted  with  a 
series  of  shelves,  or  floors,  the  passage  from  one  compartment  to  that  above  it  being 
through  a  short  tube,  bent  at  right  angles,  and  open  at  either  end ;  p,  p,  p,  is  a  general 
tube,  for  receiving  the  vapors  condensed  in  case  of  the  turns  of  the  large  serpentine 
within  E.     The  axis  of  this  worm  is  horizontal ;  q,  q,  q,  peep-holes  in  the  top  of  the 
wine-heater ;  r,  a  tube  to  conduct  the  alcoholic  vapors  not  condensed  in  the  worm  of 
E,  and  also,  if  desired,  those  which  have  been  condensed  there,  into  the  worm  of  the 
refrigeratory,  f;  ^  a  tube  to  bring  the  vinasse  from  the  reservoir,  g,  into  the  lower  part 


746 


STILL. 


of  the  cooler,  f;  ^,  a  tube  to  lead  the  vinasse  from  the  upper  part  of  the  cooler,  f,  inU 
the  upper  part  of  the  wine  heater,  e;  w,  a  funnel;  v,  a  stop-cock  to  feed  the  tube,  (, 
with  vmasse ;  ar,  a  tube  of  outlet  for  the  spirits  produced ;  it  ends,  as  shown  in  the  figure, 
in  a  test  tube  containing  an  hydrometer. 
The  still  of  Laugier  is  represented  by  a  general  view  in^.  1878.    a  and  b  are  alcmbict 


STONE,  ARTIFICIAL. 


747 


exposed  to  the  direct  action  of  the  fire,  and  serve  a  like  purpose  to  those  of  fia  1377  •  a 
IS  a  cylinder  containing  the  rectifier,  and  serving  as  a  wine-heater ;  d.  is  the  condensing 
cylinder;  a,  a  stop-cock  communicating  with  the  wine  tun;  b,  a  plunger  tube  fur- 
nished with  a  funnel,  through  which  wine  runs  constantly  into  the  condenser  d-  c  an 
overflow  of  pipe  d,  between  c  and  d,  communicating  by  a  tube,  dipping  in  the'cylinder 
c;  ^  a  plunger  equilibrium  tube,  supplying  the  alembics  with  hot  wine;  /a  tubi 
leading  the  vapors  of  the  first  alembic,  a,  into  the  second  one,  b,  into  which  it  dips-  iT 
rif/Jsl/*'         ?"i?  *K^  '''P^''^  of  alcohol  from  the  alembic,  b,  into  the  circles  of  the 

nfrl»  ^  ?u  ^  *"^fi  ^"°.^'"^  ^u^'^  '".^^  ^^^  *^^™^'^'  «•  *^«  ^«P«»-«  condensed  in  the 
Circles  of  the  rectifier;  ^  a  tube  conducting  the  vapors  not  condensed  into  the  worm 
of  the  condenser:  t,  a  tube  serving  for  the  expulsion  of  the  air  when  the  wine  cornea 
into  the  vessel  c;  It  communicates  with  the  tube,  A,  so  as  not  to  lose  alcohol.    Thl 

tact  with  the  external  air;  /,  a  stop-cock  through  which  the  alcohol  condensed  runs  off 
f 'n.  UibeTth  ::;  "'  ''w^  indicating  the  height  of  the  liquor  in  the  alembics  a  and 
8^;:^  vinasle  (washr  ^"^  "'  "''"'"  ^^''^''^'  stopcock  of  the 

Thtn?!iSf '^"  ''7^''  ""^^u^T.  ""^  ^'i'  ^'f  '^^}  ^"^  ^^°^^^  t^^t  «^  the  second  intelligible. 

The  alembic,  a,  being  filled  three-fourths  with  vinasse,  and  b  having  only  4  or  5  inchei 
of  vinasse  over  its  bottom,  the  liquor  in  a  is  made  to  boil,  and  the  stoVcock.  r,  being^ 
the  same  time  opened,  some  of  the  wine  to  be  distilled  is  allowed  to  fall  iito  the  fun- 
heateV  bv  the  Ih'^"?'  '""'  "f  ^^l  bottom  of  the  cooler,  k,  fills  it,  passes  into  the  wine- 

itf^tl^to^tal^^^^  ^^-"^^^^  itscompart^mentfirfSnt 

1.^^""°^  *'"«  f«f  ^^'  the  liquor  of  a  having  begun  to  boil,  the  alcoholic  vapor  passes 
by  means  of  the  tube  .,  ..  into  the  second  alembic  b,  which,  being  heateTbv  Xese 
vapors,  and  by  the  produets  of  combustion  issuing  frim  the'fire-pLe  under  the  fi^ 
fKl?'  ''  ^f  %'?i,"  r^'  '^  *^^^'-  .  '^^^  ^^P°^  ^^"<^h  it  produce?  is  disengaged  into 

Bartm  r\     ^'f '"f '-f  "'  "^''-^  ^V.**'  ^^'  ^'°«  ^^»«^  trickles  through  flllts  cor^ 
partmen^  transfers  to  it  a  portion  of  its  heat,  and  deprives  it  of  alcohol,  goes  into  the 


column  D,  where  it  is  alcoholized  afresh,  then  enter  into  the  worm  within  the  wine- 
heater  E,  glides  through  all  its  windings,  gets  stripped  in  part  of  the  aqueous  vapors 
which  accompanied  the  alcohol,  and  which  returns  first  by  the  tube  p,  p,  then  by  I,  ?, 
into  the  column  of  rectification  :  afterward  the  spirituous  vapors  passes  into  the  worm 
enclosed  in  the  cooler  f,  to  issue  finally  condensed  and  deprived  of  all  the  water, 
wished  to  be  taken  from  it,  by  the  tube  x,  into  the  gauge  receiver. 

When  the  indicator/,  of  the  alembic  b,  shows  it  to  be  nearly  full,  the  stop-cock  a  of 
the  alembic  a  is  opened,  and  the  vinasse  is  allowed  to  run  out  entirely  exhausted  of 
spirit;  but  as  soon  as  there  are  only  seven  inches  of  liquor  above  the  discharge  pipe, 
tne  cock  a  is  shut,  and  d  is  opened  to  run  off  seven  inches  of  liquor  from  b. 

It  appears,  therefore,  that  in  reference  to  the  discharge,  the  operation  is  not  quite 
continuous;  but  this  slight  interruption  is  a  real  improvement  introduced  by  M. 
Derosne  into  the  working  of  M.  Blumenthal's  apparatus.  It  is  impossible  for  any 
distiller,  however  expert,  to  exhaust  entirely  the  liquor  of  the  last  alembic,  if  the 
discharge  be  not  stopped  for  a  short  time.  The  above  distilling  apparatus  requires 
from  two  to  three  hours  to  put  it  in  full  action.     From  10  to  15  per  cent,  of  spirit  of  5. 

are  obtained  from  the  average  of  French  wine !  and  600  litres  of  such  spirit  are  run  off 
with  150  kilogrammes  of  coals;  or  about  two  old  English  quarts  cf  spirits  for  each 
pound  of  coals. 

STOCKING  MANUFACTURE.     See  Hosiery. 

STONE,  is  earthy  matter,  condensed  into  so  hard  a  state  as  to  yield  only  to  the  blows 
of  a  hammer,  and  therefore  well  adapted  to  the  purposes  of  building.  Such  was  the 
care  of  the  ancients  to  provide  strong  and  durable  materials  for  their  public  edifices,  that 
but  for  the  desolating  hands  of  modern  barbarians,  in  peace  and  in  war,  most  of  the 
temples  and  other  public  monuments  of  Greece  and  of  Rome  would  have  remained 
perfect  at  the  present  day,  uninjured  by  the  elements  during  2000  years.  The  contrast, 
m  this  respect,  of  the  works  of  modern  architects,  especially  in  Great  Britain,  is  very 
humiliating  to  those  who  boast  so  loudly  of  social  advancement;  for  there  is  scarcely 
a  public  building  of  recent  date  which  will  be  in  existence  one  thousand  years  hence. 
Many  of  the  most  splendid  works  of  modern  architecture  are  hastening  to  decay,  in 
what  may  be  justly  called  the  very  infancy  of  their  existence,  if  compared  with  the 
date  of  those  erected  in  ancient  Italy,  Greece,  and  Egypt.  This  is  remarkably  the  case 
with  the  three  bridges  of  London,  Westminster,  and  Blackfriars;  the  foundations  of 
which  began  to  perish  most  visibly  in  the  very  lifetime  of  their  constructors.  Every 
stone  intended  for  a  durable  edifice  ought  to  be  tested  as  to  its  durability,  by  immer- 
sion in  a  saturated  solution  of  sulphate  of  soda,  and  exposure  during  some  days  to  the 
air.  The  crystallization  which  ensues  in  its  interior  will  cause  the  same  disintegration 
of  its  substance  which  frost  would  occasion  in  a  series  of  years. 

STONES,  for  building,  and  bricks,  may  be  proved  as  their  power  of  resisting  the 
action  of  frost,  by  the  above  method,  first  practised  by  M.  Brard,  and  afterward  by 
MM.  Vicat,  Billaudel,  and  Coarad,  engineers  of  the  bridges  and  highways  in  France. 
The  operation  of  water  in  congealing  within  the  pores  of  a  stone  may  be  imitated  by 
the  action  of  a  salt,  which  can  increase  in  bulk  by  a  cause  easily  produced  ;  such  as 
efflorescence  or  crystallization,  for  example.  Sulphate  of  soda  or  Glauber's  salt  answers 
the  purpose  perfectly,  and  it  should  be  applied  as  follows : — 

Average  samples  of  the  stones  in  their  sound  state,  free  from  shakes,  should  be  sawed 
into  pieces  2  or  3  inches  cube,  and  numbered  with  China  ink  on  a  graving  tool.  A 
large  quantity  of  Glauber's  salt  should  be  dissolved  in  hot  water,  and  the  solution  should 
be  left  to  cool.  The  clear  saturated  solution  being  heated  to  the  boiling  point  in  a 
saucepan,  the  several  pieces  of  stone  are  to  be  suspended  by  a  thread  in  the  liquid  for 
exactly  one  half-hour.  They  are  then  removed  and  hung  up  each  by  itself  over  a  ves- 
sel containing  some  of  the  above  cold  saturated  solution.  In  the  course  of  24  hours,  if 
the  air  be  not  very  damp  or  cold,  a  white  efflorescence  will  appear  upon  the  stones. 
Each  piece  must  be  then  immersed  in  the  liquor  in  the  subjacent  vessel,  so  as  to  cause 
the  crystals  to  disappear,  and  be  once  more  hung  up — and  dipped  again  whenever  the 
dry  efflorescence  lorms.  The  temperature  of  the  apartment  should  be  kept  as  uniform 
as  possible  during  the  progress  of  the  trials.  According  to  their  tendency  to  exfoliate 
by  frost,  the  several  stones  will  show,  even  in  the  course  of  the  first  day,  alterations 
on  the  edges  and  angles  of  the  cubes;  and  in  five  days  after  the  efflorescence  begins, 
the  results  will  be  manifest,  and  may  be  estimated  by  the  weight  of  disintegrated  fragments^ 
compared  to  the  known  weight  of  the  piece  in  its  original  state,  both  taken  equally  dry. 

STONE,  ARTIFICIAL,  for  statuary  and  other  decorations  of  architecture,  has 
been  made  for  several  years  with  singular  success  at  Berlin,  by  Mr.  Feilner.  His 
materials  are  nearly  the  same  with  those  of  English  pottery ;  and  the  plastic  mass  is 
fashioned  either  in  moulds,  or  by  hand.  His  kilns,  which  are  peculiar  in  form,  and 
economical  in  fuel,  deserve  to  be  generally  known.  Iiffs.  1379  and  1380  represent  his 
round  kiln;  Jig.  1319  being  an  oblique  section  in  the  line  a,  b,  c,  of  Jiff.  1380,  which  ia 


748 


STONE,  ARlxtiLiAL. 


a  ground  plan  in  the  line  i>,  a.  &  b.  of  /£<r  is'zq     tK/»  ;«««-  -•      i  • 

with  the  elliptical  arch,  is  filled  wTth  the  w!s  to^e  balJ/  '."^*''  T^V^  "^'^'''"^ 
The  hearth  is  a  few  feet  above  the  ground-  anTtiierP  «r.  !?'  V''?^''  brick  supports 
the  workmen  to  mount  by,  in  charS  tS;  kSn  i^.  %  ^^^  ^-^^^^^  *^^  ^****^  ^  ^«» 
under  the  hearth.  The  /ame  of  eafi  f>aLes  a^^3ng  t^e  sfrai^h^SS'^'S^^  ^V?";."^x^ 
the  second  annular  flue  a  a,  as  also  in  thTthird  ?  /  th?fl«  J  /^l-O'  *?^/»'/*-  I" 
being  separated  from  th?'  fdjoinirg.";  tL''st^^^^^^^^^  ^^^^  Wh'flt  :iCe 

flames  again  come  together,  as  also  in  o,  and  ascend  by  t^e  middle  oSnirB^sidp! 

^^^^  1380 


flames  into  the  upper  space  u  which  is  usually  left  empty.     These  vents  can  be  closed 
by  iron  damper-plates,  pushed  in  through  the  slide-slits  of  the  dome,     t,  t,  are  peei> 

ttkid'un   X"?4^l''''''1-'^r^^^^^  ^"^  '^^y^^'  mo'st'comn^^n^ 

bricked  up.    Mff.    381  is  a  vertical  section,  and  Jig.  1382  a  plan,  o(  an  excellent  kiln  for 

baking  clay  to  a  stony  consistence,  for  the  above  purpose,  or  for  burning  fire  briok^ 
1881 


1882 


ch  mney  kT  a\te™^^^^^^^^^  ^°?.  ^'  *^«  ^-^.  terminating  in  the 

with  a/iron  doo;  c.  d,  L  tfe  peep  ho  e  fiZ"J'  ^f.'"^?^  ""'  '^'  ^'^'''  ^'  >'«  ^«^ered 
/,/  a  vent  in  the  middle  of  earha^rch^ifl  with  a  clay  stopper;  .,  is  the  fire-place; 
tween  the  two  fireplaces  i  if  ^11  .J'/'  ^"f  ^^  *^^  ^'^^«  ^^  ^^^  a*"«he8.  situated  be- 
;,  a  grate  f^r  the^ll^he^^^^^^^^^  to  be  baked; 

ings  through  which  the  flamesof  a  second  fiL^Ufk  *^^"P^'  '*' ^h^  fire-door;  o,  open- 
kiln  .  .  fifed.  wUa  deft  biUets  of  ^CwVoS!  traS  Tt  thto^l^S^^rrt^K 


STOVE. 


749 


Ib  finished,  the  second  is  fired ;  and  then  the  third  in  like  manner.  This  kiln  is  very 
like  the  porcelain  kiln  of  Sevres,  and  is  employed  in  many  cases  for  baking  stoneware. 
Mr.  Keene  obtained  a  patent  a  few  years  ago,  for  making  a  factitious  stone-paste 
in  the  following  way: — He  dissolves  one  pound  of  alum  in  a  gallon  of  water,  and 
in  this  solution  he  soaks  84  pounds  of  gypsum  calcined  in  small  lumps.  He  exposes 
these  lumps  in  the  open  air  for  about  eight  days,  till  they  became  apparently  dry  and 
then  calcines  them  in  an  oven  at  a  dull-red  heat  The  waste-heat  of  a  coke  oven  ia 
well  adapted  for  this  purpose.  (See  Pitcoal,  coking  of.)  These  lumps,  being  ground 
and  sifted,  afford  a  fine  powder,  which,  when  made  up  into  a  paste  with  the  proper 
quantity  of  water,  forms  the  petrifying  ground.  The  mass  soon  concretes,  and  after 
being  brushed  over  with  a  thin  layer  of  the  petrifying  paste,  may  be  polished  with 

Eumice,  Ac,  in  the  usual  way.  It  then  affords  a  body  of  great  compactness  and  dura- 
ility.  If  half  a  pound  of  copperas  be  added  to  the  solution  of  the  alum,  the  gypsum 
paste,  treated  as  above,  has  a  fine  cream  or  yellow  color.  This  stone  stands  the  weather 
tolerably  well. 

STONEWARE  {Fayence  Fr. ;  Steingut  Germ.)    See  Pottery. 

STORAX,  STYRAX,  flows  from  the  twigs  and  the  trunk  of  the  Liquidamher 
ityracijlua,  a  tree  which  grows  in  Louisiana,  Virginia,  and  Mexico.  Liquidamber,  aa 
this  resin  is  also  called,  is  a  brown  or  ash-gray  substance,  of  the  consistence  of  turpen- 
tine, which  dries  up  rapidly,  has  an  agreeable  smell,  like  benzoin,  and  a  bitterish,  sharp, 
burning  taste.  It  dissolves  in  four  parts  of  alcohol,  and  affords  1-4  per  cent  of  benzoic 
acid. 

STOVE  (Poelej  Calorifdre,  Fr. ;  O/en^  Germ.),  is  a  fire-place,  more  or  less  close,  foi 
warming  apartments.  When  it  allows  the  burning  coals  to  be  seen,  it  is  called  a  stove- 
grate.  Hitherto  stoves  have  rarely  been  had  recourse  to  in  this  country  for  heating  our 
sitting-rooms ;  the  cheerful  blaze  and  ventilation  of  an  open  fire  being  generally  prefer* 
red.  But  last  winter,  by  its  inclemency,  gave  birth  to  a  vast  multitude  of  projects  for 
increasing  warmth  and  economizing  fuel,  many  of  them  eminently  insalubrious,  by  pre- 
senting due  renewal  of  the  air,  and  by  the  introduction  of  noxious  fumes  into  it.  When 
coke  is  burned  very  slowly  in  an  iron  box,  the  carbonic  acid  gas  which  is  generated, 
being  half  as  heavy  again  as  the  atmospherical  air,  cannot  ascend  in  the  chimney  at  the 
temperature  of  300°  F. ;  but  regurgitates  into  the  apartment  through  every  pore  of  the 
stove,  and  poisons  the  atmosphere.  The  large  stoneware  stoves  of  France  and  Germany 
are  free  from  this  vice ;  because,  being  fed  with  fuel  from  the  outside,  they  cannot  pro- 
duce a  reflux  of  carbonic  acid  into  the  apartment,  when  their  draught  becomes  feeble,  as 
inevitably  results  from  the  obscurely  burning  stoves  which  have  the  doors  of  the  fire-place 
and  ash-pit  immediately  above  the  hearth-stone. 

I  have  recently  performed  some  careful  experiments  upon  this  subject,  and  find  that 
when  the  fuel  is  burning  so  slowly  in  the  stove  as  not  to  heat  the  iron  surface  above  the 
250th  or  300th  degree  of  Fahr.,  there  is  a  constant  deflux  of  carbonic  acid  gas  from  the 
ash-pit  into  the  room.  This  noxious  emanation  is  most  easily  evinced  by  applying  the 
beak  of  a  matrass,  containing  a  little  Goulard's  extract  (solution  of  subacetate  of  lead), 
to  a  round  hole  in  the  door  of  the  ash-pit  of  a  stove  in  this  languid  state  of  combustion. 
In  a  few  seconds  the  liquid  will  become  milky,  by  the  reception  of  carbonic  acid  gas.  I 
shall  be  happy  to  afford  ocular  demonstration  of  this  fact  to  any  incredulous  votary 
of  the  pseudo-economical,  anti-ventilation  stoves,  now  so  much  in  vogue.  There  is  no 
mode  in  which  the  health  and  life  of  a  person  can  be  placed  in  more  insidious  jeopardy, 
than  by  sitting  in  a  room  with  its  chimney  closed  up  with  such  a  choke-damp-vomiting 
stove. 

That  fuel  may  be  consumed  by  an  obscure  species  of  combustion,  with  the  emission  of 
very  little  heat,  was  clearly  shown  in  Sir  H.  Davy's  Researches  on  Flame,  «  The  facts 
detailed  on  insensible  combustion,"  says  he,  "  explain  why  so  much  more  heat  is  obtained 
from  fuel  when  it  is  burned  quickly,  than  slowly ;  and  they  show  that,  in  all  cases,  the 
temperature  of  the  acting  bodies  should  be  kept  as  high  as  possible  ;  not  only  because 
the  general  increment  of  heat  is  greater,  but  likewise  because  those  combinations  are 
prevented,  which,  at  lower  temperatures,  take  place  without  any  considerable  production 
of  heat.  These  facts  likewise  indicate  the  source  of  the  great  error  into  which  experi- 
menters have  fallen,  in  estimating  the  heat  given  out  in  the  combustion  of  charcoal ;  and 
they  indicate  methods  by  which  the  temperature  may  be  increased,  and  the  limits  to 
certain  methods."  These  conclusions  are  placed  in  a  strong  practical  light  by  the  follow- 
ing simple  experiments:—!  set  upon  the  top  orificeof  a  small  cylindrical  stove,  a  hemis- 
pherical copper  pan,  containing  six  pounds  of  water,  at  60°  F.,  and  burned  briskly  under 
it  three  and  a  half  pounds  of  coke  in  an  hour;  at  the  end  of  which  time,  four  and  a  half 
pounds  of  water  were  boiled  off.  On  burning  the  same  weight  of  coke  slowly  in  the 
same  furnace,  mounted  by  the  same  pan,  in  the  course  of  twelve  hours,  little  more  than 
one  half  the  quantity  of  water  was  exhaled.    Yet,  in  the  first  case,  the  aerial  products 


-■l^J! I  , 


750 


1883 


STOVE. 

of  combustion  swept  so  rapidly  over  the  bottom  of  tb« 
pan,  as  to  communicate  to  it  not  more  than  one-fourth  of 
the  effective  heat  which  might  have  been  obtained  by  one 
of  the  plans  described  in  the  article  Evaporation  ;  while 
in  the  second  case,  these  products  moved  at  least  twelve 
times  more  slowly  across  the  bottom  of  the  pan,  and  ought 
therefore  to  have  been  so  much  the  more  effective  in  eva- 
poration, had  they  possessed  the  same  power  or  quantity 
of  heat. 

Stoves,  when  properly  constructed,  may  be  employed 
both  safely  and  advantageously  to  heat  entrance-halls  upon 
the  ground  story  of  a  house ;  but  care  should  be  taken  not 
to  vitiate  the  air  by  passing  it  over  ignited  surfaces,  as  is 
the  case  with  most  of  the  patent  stoves  now  foisted  upon 
the  public.  Fig.  1383  exhibits  a  vertical  section  of  a 
stove  which  has  been  recommended  for  power  and  econo- 
my; but  it  is  highly  objectionable,  as  being  apt  to  scorch 


STOVE. 


751 


the  air.     The    flame   of  the   fire   a, 

the  horizontal  pipes  of  cast-iron,  6,  6,  c,  c,  (2,  d. 


circulates  round 
e,  e, 
which  receive  the  external  air  at  the  orifice  b,  and 
conduct  it  up  through  the  series,  till  it  issues  highly  heated  at  k,  l,  and  may  be  thence 
eonducted  wherever  it  is  wanted.  The  smoke  escapes  through  the  chimney  b.  This 
ttove  has  evidently  two  prominent  faults;  first,  it  heats  the  air-pipes  very  unequally, 
and  the  undermost  far  too  much ;  secondly,  the  air,  by  the  time  it  has  ascended  through 
the  zigzag  range  to  the  pipe  e  e,  will  be  nearly  of  the  same  temperature  with  it,  and  will 
therefore  abstract  none  of  its  heat.  Thus  the  upper  pipes,  if  there  be  several  in  the  range^ 
will  be  quite  inoperative,  wasting  their  warmth  upon  the  sooty  air. 

Fig,  1074  exhibits  a  transverse  vertical  section  of  a  far  more  economical  and  powerful 
Itove,  in  which  the  above  evils  are  avoided.     The  products  of  combustion  of  the  fire  a, 

1383        ^..,r-^sg;^^<MisMji^^^^  *     ^^^^  "P  between  two  brick  walls,  so 

as  to  play  upon  the  bed  of  tiles  b, 
where,  aAer  communicating  a 
moderate  heat  to  the  series  of  slant- 
ing pipes  whose  areas  are  represent- 
ed by  the  small  circles,  a,  a,  they 
turn  to  the  right  and  left,  and  circu- 
late round  the  successive  rows  of 
pipes  bbj  c  c,d  djC  e,  and  finally  es- 
cape at  the  bottom  by  the  flues  g,  g, 
pursuing  a  somewhat  similar  path  to 
that  of  the  burned  air  among  a 
bench  of  gas-light  retorts.  It  is 
known,  that  two  thirds  of  the  fuel 
have  been  saved  in  the  gas-works  by 
this  distribution  of  the  furnace.  For 
the  purpose  of  heating  apartments, 
the  great  object  is  to  supply  a  vast 
body  of  genial  air ;  and,  therefore, 
merely  such  a  moderate  fire  should 
be  kept  up  in  a,  as  will  suffice  to 
warm  all  the  pipes  pretty  equably  to 
the  temperature  of  220°  Fahr. ;  and,  indeed,  as  they  are  laid  with  a  slight  slope,  are  open 
to  the  air  at  their  under  ends,  and  terminate  at  the  upper  in  a  common  main  pipe  or  tun 
nel,  they  can  hardly  be  rendered  very  hot  by  any  intemperance  of  firing.  I  can  safely 
recommend  this  stove  to  my  readers.  If  the  tubes  be  made  of  stoneware,  its  construction 
will  cost  very  little;  and  they  may  be  made  of  any  size,  and  multiplied  so  as  to  carry  off 
the  whole  effective  heat  of  the  fuel,  leaving  merely  so  much  of  it  in  the  burned  air,  as  to 
waft  it  fairly  up  the  chimney. 

I  shall  conclude  this  article  by  a  short  extract  of  a  paper  which  was  read  before  the 
Royal  Society,  on  the  16th  of  June,  1836,  upon  warming  and  ventilating  apartments;  a 
subject  to  which  my  mind  had  beeA  particularly  turned  at  that  time,  by  the  Directors 
of  the  Customs  Fund  of  Life  Assurance,  on  account  of  the  very  general  state  of  indis- 
position and  disease  prevailing  among  those  of  their  officers  (nearly  100  in  number)  en- 
gaged on  duty  in  the  Long  Room  of  the  Custom  House,  London. 

"The  symptoms  of  disorder  experienced  by  the  several  gentlemen  (about  twenty  in 
number)  whom  I  examined,  out  of  a  great  many  who  were  indisposed,  were  of  a  verf 
uniform  character.     The  following  is  the  result  of  my  researches  : — 

"  A  sense  of  tension  or  fulness  of  the  head,  with  occasional  flushings  of  the  coun- 
tenance, throbbing  of  the  temples,  and  vertigo,  followed,  not  unfrequently,  with  a  con- 


fusion of  ideas,  very  disagreeable  to  officers  occupied  with  important  and  sometimes 
intricate  calculations.  A  few  are  affected  with  unpleasantperspiration  on  their  sides. 
The  whole  of  them  complain  of  a  remarkable  coldness  and  languor  in  their  extremities, 
more  especially  the  legs  and  feet,  which  has  become  habitual,  denoting  languid  cir- 
culation in  these  parts,  which  requires  to  be  counteracted  by  the  application  of  warm 
flannels  on  going  to  bed.  The  pulse  is,  in  many  instances,  more  feeble,  frequent,  sharp, 
and  irritable,  than  it  ought  to  be,  according  to  the  natural  constitution  of  the  individuals. 
The  sensations  in  the  head  occasionally  rise  to  such  a  height,  notwithstanding  the  most 
temperate  regimen  of  life,  as  to  require  cupping,  and  at  other  times  depletory  remedies. 
Costiveness,  though  not  a  uniform,  is  yet  a  prevailing  symptom. 

**The  sameness  of  the  above  ailments,  in  upwards  of  one  hundred  gentlemen,  at  very 
various  periods  of  life,  and  of  various  temperaments,  indicates  clearly  sameness  in  the 
cause. 

"The  temperature  of  the  air  in  the  Long  Room  ranged,  in  the  three  days  of  my  expe- 
rimental inquiry,  from  62"  to  64®  of  Fahrenheit's  scale  ;  and  in  the  Examiner's  Room  it 
was  about  60**,  being  kept  somewhat  lower  by  the  occasional  shutting  of  the  hot-air 
valve,  which  is  here  placed  under  the  control  of  the  gentlemen ;  whereas  that  of  the 
Long  Room  is  designed  to  be  regulated  in  the  sunk  story,  by  the  fireman  of  the  stove, 
who  seems  sufficiently  careful  to  maintain  an  equable  temperature  amidst  all  the  vicis- 
situdes of  our  winter  weather.  Upon  the  7th  of  January,  tha  temperature  of  the  open 
air  was  50';  and  on  the  11th  it  was  only  35*» ;  yet  upon  both  days  the  thermometer  ia 
the  Long  Room  indicated  the  same  heat,  of  from  62°  to  64°. 

"  The  hot  air  discharged  from  the  two  cylindrical  stove-tunnels  into  the  Long  Room 
was  at  90°  upon  the  7lh,  and  at  110°  upon 'the  11th.  This  air  is  diluted,  however,  and 
disguised,  by  admixture  with  a  column  of  cold  air,  before  it  is  allowed  to  escape.  The 
air,  on  the  contrary,  which  heats  the  Examiner's  Room,  undergoes  no  such  mollification, 
and  comes  forth  at  once  in  an  ardent  blast  of  fully  170°;  not  unlike  the  simoom  of  the 
desert,  as  described  by  travellers.  Had  a  similar  nuisance,  on  the  greater  scale,  existed 
in  the  Long  Room,  it  could  not  have  been  endured  by  the  merchants  and  other  visiters 
on  business :  but  the  disguise  of  an  evil  is  a  very  different  thing  from  its  removal. 
The  direct  air  of  the  stove,  as  it  enters  the  Examiner's  Room,  possesses,  in  an  eminent 
degree,  the  disagreeable  smell  and  flavor  imparted  to  air  by  the  action  of  red-hot  iron ; 
and,  in  spite  of  every  attention  on  the  part  of  the  fireman  to  sweep  the  stove 
apparatus  from  time  to  time,  it  carries  along  with  it  abundance  of  burned  dusty 
particles. 

"  The  leading  characteristic  of  the  air  in  these  two  rooms,  is  its  dryness  and  disagree- 
able smell.  In  the  Long  Room,  upon  the  11th,  the  air  indicated,  by  Daniell's  hygro- 
meter, 70  per  cent,  of  dryness,  while  the  external  atmosphere  was  nearly  saturated  with 
moisture.  The  thermometer  connected  with  the  dark  bulb  of  that  instrument  stood  at 
30**  when  dew  began  to  be  deposited  upon  it;  while  the  thermometer  in  the  air  stood  at 
64°.  In  the  court  behind  the  Custom-house,  the  external  air  being  at  35°,  dew  was 
deposited  on  the  dark  bulb  of  the  hygrometer  by  a  depression  of  only  3° ;  whereas  in 
the  Long  Room,  on  the  same  day,  a  depression  of  34°  was  required  to  produce  that 
deposition.  Air,  in  such  a  dry  state,  would  evaporate  0-44  in  depth  of  water  from  a 
cistern  in  the  course  of  twenty-four  hours ;  and  its  influence  on  the  cutaneous  exhalants 
must  be  proportionably  great. 

"  As  cast  iron  always  contains,  besides  the  metal  itself,  more  or  less  carbon,  sulphur, 
phosphorus,  or  even  arsenic,  it  is  possible  that  the  smell  of  air  passed  over  it  in  an 
incandescent  state,  may  be  owing  to  some  of  these  impregnations ;  for  a  quantity  of 
noxious  effluvia,  inappreciably  small,  is  capable  of  affecting  not  only  the  olfactory 
nerves,  but  the  pulmonary  organs.  I  endeavored  to  test  the  air  as  it  issued  from  the 
valve  in  the  Examiner's  Room,  by  presenting  to  it  pieces  of  white  paper  moistened  with 
a  solution  of  nitrate  of  silver,  and  perceived  a  slight  darkening  to  take  place,  as  if  by 
sulphurous  fumes.  White  paper,  moistened  with  sulphureted  hydrogen  water,  was 
not  in  the  least  discolored.  The  faint  impression  on  the  first  test  paper,  may  be, 
probably,  ascribed  to  sulphurous  fumes,  proceeding  from  the  ignition  of  the  myriads  of 
animal  and  vegetable  matters  which  constantly  float  in  the  atmosphere,  as  may  be  seen 
in  the  sunbeam  admitted  into  a  dark  chamber:  to  this  cause,  likewise,  the  offensive 
smell  of  air,  transmitted  over  red-hot  iron,  may  in  some  measure  be  attributed,  as  well 
as  to  the  hydrogen  resulting  from  the  decomposition  of  aqueous  vapor,  always  present 
in  our  atmosphere  in  abundance;  especially  close  to  the  banks  of  the  Thames,  below 
London  Bridge. 

«  When  a  column  of  air  sweeps  furiously  across  the  burning  deserts  of  Africa  and 
Arabia,  constituting  the  phenomenon  called  simoom  by  the  natives,  the  air  becomes 
not  only  very  hot  and  dry,  but  highly  electrical,  as  is  evinced  by  lightning  and  thunder. 
Dry  sands,  devoid  of  vegetation,  cannot  be  conceived  to  communicate  any  noxious  gas 
or  vapor  to  the  atmosphere,  like  the  malaria  of  marshes,  called  miasmata  ;  it  is,  hence, 
highly  probable  that  the  blast  of  the  simoom  owes  its  deadly  malignity,  in  reference  to 


752 


STOVE. 


I 


animal  as  well  as  yegetable  life,  simply  to  extreme  heat,  dryness,  and  electrical  disturb- 
anoe.    Similar  conditions,  though  on  a  smaller  scale,  exist  in  what  is  called  the  bell,  or 
cockle,  apparatus  for  heating  the  Long  Room  and  the  Examiner's  apartment  in  the 
Custom-house.     It  consists  of  a   series  of  invited,  hollow,  flattened  pyramids  of  cast 
iron,  wiih  an  oblong  base,  rather  small  in  their  dimensions,  to  do  their  work  sufficient!? 
in  cold  weather  when  moderately  heated.    The  inside  of  the  pyramids  is  exposed  to 
the  flames  of  coke  furnaces,  which  heat  them  frequently  to  incandescence,  while  currents 
oj  cold  air  are  directed  to  their  exterior  surfaces  by  numerous  sheet-iron  channels. 
1  he  incandescence  of  these  pyramids,  or  bells,  as  they  are  vulgarly  called,  was  proved 
by  pieces  of  paper  taking,  fire  when  I  laid  them  on  the  summits.     Aeain,  since  air  be 
comes  electrical  when  it  is  rapidly  blown  upon  the  surfaces  of  certain   bodies  .  it  oc 
curred  to  me  that  the  air  which  escapes  into  the  Examiner's  Room  might  be 'in  this 
predicament.    It  certainly  excites  the  sensation  of  a  cobweb  playing  round  the  head 
which  IS  well  known  to  all  who  are  familiar  with  electrical  machines.    To  determine 
this  point,  I  presented  a  condensing  gold-leaf  electrometer  to  the  said  current  of  hot 
air,  and  obtained  faint  divergence  with  negative  electricity.    The  electricity  must  be 
unpaired  in  its  tension,  however,  in  consequence  of  the  air  escaping  through  an  iron 
grating,  and  striking  against  the  flat  iron  valves,  both  of  which  tend  to  restore  the 
electnc  equilibrium.    The  air  blast,  moreover,  by  being  diffused  round  the  glass  of  tht 
eondensei  apparatus,  would  somewhat  mask  the  appearances.     Were  it  worth  while,  aa 
apparatus  might  be  readily  constructed  for  determining   this  point,  without  any  such 
sources  of  fallacy.     The  influence  of  an  atmosphere  charged  with  electricity  in  exciUng 
Aeadache  and  confusion  of  thought  in  many  persons,  is  universally  known. 

«  The  fetid  burned  odor  of  the  stove  air,  and  its  excessive  avidity  for  moisture,  are  of 
themselves,  however,  sufficient  causes  of  the  general  indisposition  produced  among  the 
gentlemen  who  are  permanently  exposed  to  it  in  the  discharge  of  their  public  duties. 

'  i  rom  there  being  nearly  a  vacuum,  as  to  aqueous  vapor,  in  the  said  air,  while  there 
IS  nearly  a  plenum  in  the  external  atmosphere  round  about  the  Custom-house,  the  vicissi- 
tudes of  feeling  in  those  who  have  occasion  to  sro  out  and  in  frequently,  must  be  highly 
detrimental  to  health.  The  permanent  action  of  an  artificial  desiccated  air  on  the  ani- 
mal economy  may  be  stated  as  follows  :— 

^  «  The  living  body  is  continually  emitfing  a  transpirable  matter,  the  quantity  of  which, 
m  a  grown  up  man,  will  depend  partly  on  the  activity  of  the  cutaneous  exhalants,  and 
partly  on  the  relative  dryness  or  moisture  of  the  circumambient  medium.  Its  average 
amount,  m  common  circumstances,  has  been  estimated  at  20  ounces  in  twenty-four 

«  When  plunged  in  a  very  dry  air,  the  insensible  perspiration  will  be  increased ;  and,  as 
It  IS  a  true  evaporation  or  gasefaciion,  it  will  generate  cold  proportionably  to  its  amount. 
Ihose  parts  of  the  body  which  are  most  insulated  in  the  air,  and  furthest  from  the 
heart,  such  as  the  extremities,  will  feel  this  refrigerating  influence  most  powerfuUy. 
Hence  the  coldness  of  the  hands  and  feet,  so  generally  felt  by  the  inmates  of  the  apart- 
ment, though  us  temperature  be  at  or  above  60*.  The  brain,  bein?  screened  by  the 
scull  trom  this  evaporating  influence,  will  remain  relatively  hot,  and  will  get  larchareed 
besides,  with  the  fluids  which  are  repelled  from  the  extremities  by  the  condensation 
or  contraction,  of  the  blood-vessels,  caused  by  cold.  Hence  the  affections  of  the  head! 
such  as  tension,  and  its  dangerous  consequences.  If  sensible  perspiration  happen,  from 
debihty,  to  break  forth  from  a  system  previously  relaxed,  and  plunged  into  dry  iir,  so 
attractive  of  vapor,  it  will  be  of  the  kind  called  a  cold  clammy  sweat  on  the  sides  ind 
back,  as  experienced  by  many  inmates  of  the  Long  Room. 

"Such,  in  my  humble  apprehension,  is  a  rationale  of  the  phenomena  observed  at  the 
Custom-house.  Similar  effects  have  resulted  from  hot-air  stoves  of  a  similar  kind  in 
many  other  situations. 

.il^J}?  ^^^  ""r*  "^^t'^^f.P^ys'cal  and  medical  investigation,  I  am  of  opinion  that  the 
n^fr^cr  ?r^'  abovc  specified  cannot  act  permanently  upon  human  beings,  without  im- 
pairing their  constitutions,  and  reducing  the  value  of  their  lives.  The  Directors  of 
he  Customs  Fund  are  therefore  justified  in  their  apprehensions,  '  that  the  mode  of  heat- 
in  the  Long  Room  is  injurious  to  the  health  of  persons  employed  therein,  and  that  it 
must  unduly  shorten  the  duration  of  life.'  «  »wi  « 

«*It  may  be  admitted,  as  a  general  principle,  that  the  comfort  of  sedentary  individuals 
occupying  large  apartments  during  the  winter  months,  cannot  be  adequately  secured  by 
Uie  mere  influx  of  hot  air  from  separate  stove  rooms :  it  requires  the  genial  influence 
of  radiating  surfaces  in  the  apartments  themselves,  such  as  of  open  fires,  of  pipes,  or 

fi^h'  J'f '  •  ^^-^  "^''^  ^°V  ^f  "•■  °'  '''^'^'  The 'clothing  of  oSr  bodies,  exS  Z 
IJtt  '*,^^^^'«"  \l  X  P"^.^'  ^'■^^5'  somewhat  cool  and  bracing  air,  absorbs  a  much  more 
JSS  lv7*t™«V^^'l ''  could  acquire  by  being  merely  immer'sed  in  an  atmosphere 
th.  fnl  r  ^/^"':u'^^  J^'*  f  ^^^  ^^'^^  ^««"^-    ^»  the  former  predicament, 

inrfi.plr  th  ^""^'^  1u^  a  relative  y  dense  air,  say  at  52P  Fahr. ;  while  the  external 
surlace  of  the  body  or  the  clothing  is  maintained  at,  perhaps,  TCP  or  75".    This  dis- 


STRINGS. 


753 


tanetive  circumstance  has  not,  I  believe,  been  hitherto  duly  considered  by  tht  store 
doctors,  each  intent  on  puffing  his  own  pecuniary  interest ;  but  it  is  obviously  one  of 
great  importance,  and  which  the  English  people  would  do  well  to  keep  in  view ;  because 
it  is  owing  to  our  domestic  apartments  being  heated  by  open  fires,  and  our  factories  by 
steam  pipes,  that  the  health  of  our  population,  and  the  expectation  of  life  among  all 
orders  in  this  country,  are  so  much  better  than  in  France  and  Germany,  where  hot-air 
stoves,  neither  agreeable  nor  inoffensive,  and  in  endless  variety  of  form,  are  generally 
employed. 

"  In  conclusion,  I  take  leave  to  state  to  you  my  firm  conviction  that  the  only  method 
of  warming  your  Long  Room  and  subsidiary  apartments,  combining  salubrity,  safety, 
and  economy,  with  convenience  in  erection  and  durable  comfort  in  use,  b  by  a  series 
of  steam  pipes  laid  alon?  the  floor,  at  the  line  of  the  desk  partitions,  in  suitable  lengths, 
with  small  arched  junction-pipes  rising  over  the  several  doorways,  to  keep  the  passages 
clear,  and  at  the  same  time  to  allow  a  free  expansion  and  contraction  in  the  pipes,  there- 
by providing  for  the  permanent  soundness  of  the  joints." 

It  would  not  be  difficult  to  construct  a  stove  or  stove-grate  which  should  combime 
economy  and  comfort  of  warming  an  apartment,  with  briskness  of  combustion  and  duni' 
lulity  of  the  fire,  without  any  noxious  deflux  of  carbonic  acid.    See  Chimnet. 

STRASS;  see  Pastes. 

STRAW-HAT  MANUFACTURE.  The  mode  of  preparing  the  Tuscany  oc 
Italian  straw,  is  by  pulling  the  bearded  wheat  while  the  ear  is  in  a  soft  milky  state,  the 
corn  having  been  sown  very  close,  and  of  consequence  produced  in  a  thin,  short,  and 
dwindled  condition.  The  straw,  with  its  ears  and  roots,  is  spread  out  thinly  upon  the 
ground  in  fine  hot  weather,  for  three  or  four  days  or  more,  in  order  to  dry  the  sap ;  it 
is  then  tied  up  in  bundles  and  stacked,  for  the  purpose  of  enabling  the  heat  of  the  mow 
to  drive  off  any  remaining  moisture.  It  is  important  to  keep  the  ends  of  the  straw  air« 
tight,  in  order  to  retain  the  pith,  and  prevent  its  gummy  particles  from  passing  off  by 
evaporation. 

After  the  straw  has  been  about  a  month  in  the  mow,  it  is  removed  to  a  meadow  and 
spread  out,  that  the  dew  may  act  upon  it,  together  with  the  sun  and  air,  and  promote 
the  bleaching,  it  being  necessary  frequently  to  turn  the  straw  while  this  process  is  going 
on.  The  first  process  of  bleaching  being  complete,  the  lower  joint  and  root  is  pulled 
from  the  straw,  leaving  the  upper  part  fit  for  use,  which  is  then  sorted  according  to 
qualities ;  and  after  being  submitted  to  the  action  of  steam,  for  the  purpose  of  extracting 
its  color,  and  then  to  a  fumigation  of  sulphur,  to  complete  the  bleaching,  the  straws  are 
in  a  condition  to  be  platted  or  woven  into  hats  and  bonnets,  and  are  in  that  state  imported 
into  England  in  bundles,  the  dried  ears  of  the  wheat  being  still  on  the  straw. 

Straw  may  be  easily  bleached  by  a  solution  of  chloride  of  lime,  and  also  by  sulphuring. 
For  the  latter  purpose,  a  cask  open  at  both  ends,  with  its  seams  papered,  is  to  be  set 
upright  a  few  inches  from  the  ground,  having  a  hoop  nailed  to  its  inside,  about  six 
inches  beneath  the  top,  to  support  another  hoop  with  a  net  stretched  across  it,  upon 
which  the  straw  is  to  be  laid  in  successive  handfuls  loosely  crossing  each  other.  The 
cask  having  been  covered  with  a  tight  overlapping  lid,  stuffed  with  lists  ^£  cloth,  a 
brasier  of  burning  charcoal  is  to  be  inserted  within  the  bottom,  and  an  iron  dish  con- 
.dining  pieces  of  brimstone  is  to  be  put  upon  the  brasier.  The  brimstone  soon  takes 
fire,  and  fills  the  cask  with  sulphurous  acid  gas,  whereby  the  straw  gets  bleached  in  the 
course  of  three  or  four  hours.  Care  should  be  taken  to  prevent  such  a  violent  combu-stion 
of  the  sulphur  as  might  cause  black  burned  spots,  for  these  cannot  be  afterwards  removed. 
The  straw,  after  being  aired  and  softened  by  spreading  it  upon  the  grass  for  a  night, 
is  ready  to  be  split,  preparator>'  to  dyeing.  Blue  is  given  by  a  boiling-hot  solution  of 
indigo  in  sulphuric  acid,  called  Saxon  bitte,  diluted  to  the  desired  shade  ;  yellow,  by  de- 
coction of  turmeric  ;  red,  by  boiling  hanks  of  coarse  scarlet  wool  in  a  bath  of  weak  alum 
water,  containing  the  straw ;  or  directly,  by  cochineal,  salt  of  tin,  and  tartar.  Brazil 
wood  and  archil  are  also  employed  for  dyeing  straw.  For  the  other  colors,  see  their  re- 
spective titles  in  this  Dictionary. 

STREAM-WORKS.  The  name  given  by  the  Cornish  miners  to  alluvial  deposits  cf 
tin  ore,  usually  worked  in  the  open  air. 

STRETCHING  MACHINR     Cotton  goods  and  other  textile  fabrics,  either  white  or 

t)rinted,  are  prepared  for  the  market  by  being  stretched  in  a  proper  machine,  which 
ays  all  their  warp  and  woof  yarns  in  truly  parallel  positions.  A  very  ingenious  and 
effective  mechanism  of  this  kind  was  made  the  subject  of  a  patent  by  Mr.  Samuel  Mo- 
rand,  of  Manchester,  in  April,  1834,  which  serves  to  extend  the  width  of  calico  piecei^ 
or  of  other  cloths  woven  of  cotton,  wool,  silk,  or  flax,  after  they  have  become  shrunk 
in  the  processes  of  bleaching,  dyeing,  <fec.  I  regret  that  the  limits  of  this  volume  will 
not  admit  of  its  description.  The  specification  of  the  patent  is  published  in  Newton** 
Journal,  for  December,  1835. 

STRINGS.    The  name  given  by  the  Cornish  miners  to  the  small  filamentous  ramifr 
cations  of  a  metallic  yein. 
Vol.  II.— 48 


754 


SUGAR. 


V 


3«  nf  i?r'  """'•  ^'^  '^l'"'"'  ^""^  ^°^"^'^  »»  52  parts  of  water  at  6%  and  in*  a^uTI 
parts  of  bo.lmg  water ;  when  heated  they  part  with  53  parts  of  water  but  retain  thp 

o^oxviL'"}?'"'"."!  "J'^.^'^K  '^^'^  '^^  '^''"^  ^«"«i'ts  of  84-55  o?base,  and  "s!^? 
^lohlf.i,  ^^-  '^^^'^l  distinguished  from  baryta,  by  its  inferior  solubility  and  by  hi 
«o  able  salts  giying:  a  red  tinge  to  flame,  while  those  of  baryta  dve  a  yellow  tin4  K 
Jor^^r  tk""^  '^^''  °^'^.*  precipitate  the  salts  of  the  latter  earth,  but  no  those  of  S^ 
former.  The  compounds  of  stronlia  are  not  poisonous,  like  those  of  baryta  The  oS! 
'^'S^Pvrwm  A^'"^"^'''  ",f«1.i»  the  ^••ts  is  the  Nitrate;  which  see.       ^  ^  ''"'' 

i^^,i         A  }u    *rr^"  allfalme  base,  extracted  from  the  Strychnos  mix  vomica   Strvchru^ 
^a/.a  and  the  Upas  timte ;  which  has  been  employed  in  medicinnHome^f  t^ 
poison  doctors,  but  is  of  no  use  in  any  of  the  arts.     When  introduc^  Into  the  ll.h 
Btr^chnia  acts  with  fearfiil  energy,  caiisiog  lock-jaw  immediately,  and   he  death  oTth^ 

n«?n"r!"^  /If  ^"^  "  '^'"''P  ?^  ^f''*'"^  sulphuric  acid  on  a  piece  of  glass,  add  to  it  a  small 
quantity  of  the  suspected  substance,  and  stir  the  whole  togeth^^To  as  to  favor  s^lu 
mZl  !  T  '^""^^  u  ^^"''u*^"  '"'^^""^  "  ""'«  powdered  bichromate  of  potLh  and  eentlv 
"birbea^Tv^ilf  h^:;"^\'-"  ^"i^- .  {^  «^^^,-»^"-  ^e  present,  a  violet^cotr  ^f  conS 
fnf«  o  ^  ?  ^  ,1^  ^^'^^'^^  immediately  produced,  which,  after  a  few  minutes,  will  fade 
into  a  reddish  yellow,  but  may  be  renewed  by  the  addition  of  morelbiXomate  so  W 
.8  any  strychnia  remains  undestroyed  in  the  mixture.     In  this  way  ^  J_ 'Tf  a^ain  "f 

tic'ed  ar^ethatTuTphtiTtid'^^"'"  '  T^  ^^^'^^"^  ^"^'^^^^«°-  ^he"  pdnt.  to  be  no- 
Srfa  of  sulphuric  acid  alone  produces  no  apparent  effect,  and  that  the  action  be- 

gins  at  once  roun^  each  particle  of  the  bichromate,  so  that  if  the  glaL  be  heMina 
vert  cal  position,  streams  of  a  violet  colored  fluid  may  be  seen  tf  fl^w  fr.!^  A«k 
particle ;  and  if  at  this  time,  the  whole  be  slowly  stim^,  tL  enUre  buL  o  Z  Su  d 
will  speedily  assume  the  same  characteristic  tint. 

•J"  ;i°T"^/ n"  "^-'^^  'V^  ^"^"^'  ^^-  ^^«'*«o°.  «^  Southampton  Row  I  have  thus  ex 
7eZitoffr-"^  a  kaloids:  morphia,  brucia,  aconita,^tropra  codi^'^narco  ine 
S W  ^f  nil      1  T'^A"'"?'  '^^^"'^  ^"'•^'"«'  «"^  Pl^loridza,  but  without  notS  anv- 

edaVa  means  o?Sl'ln'.'^r^  ^.^""^'  "P"°  ^^^'^^"^  «^ ^^«  indication  thus  olS 
ea,  as  a  means  of  demonstrating  the  presence  of  strychnia.     In  these  exoerimenfii  fba 

thTl^tT^^  ^^  'r^'^''^  ««"g»^t  to  be  avoided  by  the  employment  ofXmaUriat' 
^e  alkaloids  having  been  manufactured  with  great  care.   Com^unds  cEnTnTniS 

loid";.nH  th"''^  ri'  ^  t^^^""^  ^^^^'•^  ""fi^  ^^'^  «"«»^  invest^ations^the  pure  alkT 
STUcVo."'se?  ^'^°^  unobjectionable.-Jfn  zJ,  77*o^p.J.P"'^^ 

SUBERIC  ACID,  is  prepared  by  digesting  grated  cork  with  nJtrJ/.  o«;i      t»  r 

sriRT  {m4t?Ak  '"''  i""**  "■"""  '■^'""'"?  f™""  condensed  vapors,  and. 
..H        i^'?'"'  "  "''^  P'"**^*  >>?  '"'''="  ">e  ™latile  pariides  are  raised  bv  h».t 
«.d  condensed  into  .  crjstalline  mass.     See  CAWM^t  and  slr  I^otrAc!  for^JlSI: 

leaT^^"'  ''  "  ""  '"  "'■'"'  ""  ■"'*  '^  "»' «"»"'«'  "i*  «Wi  as  subacetate  d 

pj?;=^  ''^-rrb  itrr^fe  dts:l  ?Sr  iS5 

nr^n.u     7^^'*  f""*,'-  ^'''^'.\^f':^-)y  is  the  sweet  constituent  of  vegetable  and  animal 
products.    It  may  be  distinguished  into  two  nrincinal  «;npriP«!     Th^  fi «♦«,>.•  T    *"™r 


SUGAR. 


755 


by  100 ;  and  in  circumpolarization  it  bends  the  luminous  rays  to  the  right  The  second 
occurs  ready  formed  in  ripe  grapes  and  other  fruits;  it  is  also  produced  by  treating 
starch  with  diastase  or  sulphuric  acid.  This  species  forms  cauliflower  concretions,  but 
not  true  crystals;  it  has  a  sweetening  power  which  may  be  represented  by  60,  and  in 
circumpolarization  it  bends  the  rays  to  the  left  Besides  these  two  principal  kinds  of 
sugar,  some  others  are  distinguished  by  chemists ;  as  the  sugar  of  milk,  of  manna,  of 
certain  mushrooms,  of  liquorice-root,  and  that  obtained  from  sawdust  and  glue  by 
the  action  of  sulphuric  acid ;  but  they  have  no  importance  in  a  manufacturing  point 
of  view. 

Sugar,  extracted  either  from  the  cane,  the  beet,  or  the  maple,  is  identical  in  its  pro- 
perties and  composition,  when  refinti  to  the  same  pitch  of  purity ;  only  that  of  the  beet 
seems  to  surpass  the  other  two  in  col  esive  force,  since  larger  and  firmer  crystals  of  it  are 
obtained  from  a  clarified  solution  of  equal  density.  It  contains  5*3  per  cent,  of  combined 
water,  which  can  be  separated  only  by  uniting  it  with  oxyde  of  lead,  into  what  has  been 
called  a  saccharale;  made  by  mixing  sirup  with  finely  ground  litharge,  and  evaporating 
the  mixture  to  dryness  upon  a  steam-bath.  When  sugar  is  exposed  to  a  heat  of  400* 
F.,  it  melts  into  a  brown  pasty  mass,  but  still  retains  its  water  of  composition.  Sugai 
thus  fused  is  no  longer  capable  of  crystallization,  and  is  called  caramel  by  the  French. 
It  is  used  for  coloring  liqueurs.  Indeed,  sugar  is  so  susceptible  of  change  by  heat,  that 
if  a  colorless  solution  of  it  be  exposed  for  some  time  to  the  temperature  of  boiling  wa- 
ter, it  becomes  brown  and  partially  uncrystallizable.  Acids  exercise  such  an  injurious 
influence  upon  sugar,  that  after  remaining  in  contact  with  it  for  a  little  while,  though 
they  be  rendered  thoroughly  neutral,  a  great  part  of  the  sugar  will  refuse  to  crystallize. 
Thus,  if  three  parts  of  oxalic  or  tartaric  acid  be  added  to  sugar  in  solution,  no  crys- 
tals of  sugar  can  be  obtained  by  evaporation,  even  though  the  acids  be  neutralized 
by  chalk  or  carbonate  of  lime.  By  boiling  cane  sugar  with  dilute  sulphuric  acid,  it  is 
changed  into  starch  sugar.  Manufacturers  of  sugar  should  be,  therefore,  particularly 
watchful  against  every  acidulous  taint  or  impregnation.  Nitric  acid  converts  sugar  into 
oxalic  and  malic  acids.  Alkaline  matter  is  likewise  most  detrimental  to  the  grain  of 
•ugar ;  as  is  always  evinced  by  the  large  quantity  of  molasses  formed,  when  an  excess  oi 
temper  lime  has  been  used  in  clarifying  the  juice  of  the  cane  or  the  beet.  When  one 
piece  of  lump  sugar  is  rubbed  against  another  in  the  dark,  a  phosphorescent  light  is 

emitted. 

Sugar  is  soluble  in  all  proportions  in  water ;  but  it  takes  four  parts  of  spirits  of  wine, 
of  spec.  grav.  0-830,  and  eighty  of  absolute  alcohol,  to  dissolve  it,  both  being  at  a  boiling 
temperature.  As  the  alcohol  cools,  it  deposites  the  sugar  in  small  crystals.  Caramelized 
and  uncrystallizable  sugar  dissolves  readily  in  alcohol.  Pure  sugar  is  unchangeable  in 
the  air,  even  when  dissolved  in  a  &Jod  deal  of  water,  if  the  solution  be  kept  covered  and 
in  the  dark ;  but  with  a  very  small  addition  of  gluten,  the  solution  soon  begins  to  fer- 
ment, whereby  the  sugar  is  decomposed  into  alcohol  and  carbonic  acid,  and  ultimately 
into  acetic  acid. 

Sugar  forms  chemical  compounds  with  the  salifiable  bases.  It  dissolves  readily  ii 
caustic  potash  ley,  whereby  it  loses  its  sweet  taste,  and  aflbrds  on  evaporation  a  mast 
which  is  insoluble  in  alcohol.  When  the  ley  is  neutralized  by  sulphuric  acid,  the  sugar 
recovers  its  sweet  taste,  and  may  be  separated  from  the  sulphate  of  potash  by  alcohol,  but 
it  will  no  longer  crystallize. 

That  sirup  possesses  the  property  of  dissolving  the  alkaline  earths,  lime,  magnesia, 
Btrontites,  barytes,  was  demonstrated  long  ago  by  Mr.  Ramsay  of  Glasgow,  by  experi- 
ments published  in  Nicholson's  Journal,  volume  xviii.  page  9,  for  September,  1807.  He 
found  that  sirup  is  capable  of  dissolving  half  as  much  lime  as  it  contains  of  sugar ;  and 
as  much  strontites  as  sugar.  Magnesia  dissolved  in  much  smaller  quantity,  and  barytes, 
seemed  to  decompose  the  sugar  entirely.  These  results  have  been  since  confirmed  by 
Professor  Daniell.  Mr.  Ramsay  characterized  sugar  treated  with  lime  as  weak,  from  its 
sweetening  power  being  impaired;  from  its  solution  he  obtained,  after  some  time,  a 
deposite  of  calcareous  carbonate.  M.  Pelouze  has  lately  shown,  that  the  carbonic  acid 
in  this  case  is  derived  from  the  atmosphere,  and  is  not  formed  at  the  expense  of  the  ele- 
ments of  the  sugar,  as  Mr.  Daniell  had  asserted. 

Sugar  fornus  with  oxyde  of  lead  two  combinations ;  the  one  soluble,  the  other  insolu- 
ble. Oxyde  of  leau  digested  in  sirup  dissolves  to  a  certain  amount^  forms  a  yellowish 
liquor,  which  possesses  an  alkaline  reaction,  and  leaves  after  evaporation  an  uncrystalli- 
zable, viscid,  deliquescent  mass.  If  sirup  be  boiled  with  oxyde  of  lead  in  excess,  if  the 
solution  be  filtered  boiling  hot,  and  if  the  vial  be  corked  in  which  it  is  received, 
white  bulky  flocks  will  fall  to  its  bottom  in  the  course  of  24  hours.  This  compound  is 
best  dried  in  vacuo.  It  is  in  both  cases' light,  tasteless,  and  insoluble  in  cold  and  boiling 
water ;  it  takes  fire  like  German  tinder,  (Amadou,)  when  touched  at  one  point  with  an 
ignited  body,  and  burns  away,  leaving  small  globules  of  lead.  It  dissolves  in  acids,  and 
also  in  neutral  acetate  of  lead,  which  forms  with  the  oxyde  a  subsalt,  and  sets  the  sugar 


756 


SUGAK. 


SUGAR. 


757 


free.   Carbonic  acid  gas  passed  through  water  in  which  the  above  saccharate  is  diffused, 
decomposes  it,  with  precipitation  of  carbonate  of  lead.    It  consists  of  58*26  parU  of  oxide 
of  lead,  and  41-74  sugar,  in  100  parts.    From  the  powerful  action  exercised  upon  sugar 
by  acids  and  oxyde  of  lead,  we  may  see  the  fallacy  and  danger  of  using  these  chemical 
reagents  m  sugar-refining.    Sugar  possesses  the  remarkable  property  of  dissolving  the 
oxyde,  as  well  as  the  subacetate  of  copper,  (verdigris,)  and  of  counteracting  their  pois( 
ous  operation.     Orfila  found  that  a  dose  of  verdigris,  which  would  kill  a  do«'  in  an  bo 
or  two,  might  be  swallowed  with  impunity,  provided  it  was  mixed  with  a  considera) 
quantity  of  sugar.  When  a  solution  of  sugar  is  boiled  with  the  acetate  of  copper,  it  caus 
an  abundant  precipitate  of  protoxyde  of  copper ;  when  boiled  with  the  nitrates  of  mercu 
•nd  silver,  or  the  chloride  of  gold,  it  reduces  the  respective  bases  to  the  metallic  state. 

The  following  Table  shows  the  quantities  of  Sugar  contained  in  Sirups  of  the  annexe 
ipecific  gravities.*    It  was  the  result  of  experiments  carefully  made. 


Experimental  specific  ^ra- 
Tity  of  solution  at  60'  F. 

Sugar  in  100,  by 
weight. 

Experimental  specific  gra- 
vity of  solution  at  60°  F. 

Sugar  in  100,  by 
weight. 

1-3260 
1-2310 
1-1777 
1-4400 
1-1340 
M250 
1-1110 

66-666 
50000 
40-000 
33-333 
31-250 
29-412 
26-316 

1-1045 
1-0905 
1-0820 
1-0685 
1-0500 
1-0395 

25-000 
21-740 
20-000 
16-666 
12-500 
10000 

If  the  decimal  part  of  the  number  denoting  the  specific  gravity  of  sirup  be  multiplied 
by  26,  the  product  will  denote  very  nearly  the  quantity  of  sugar  per  gallon  in  pounds 
weight,  at  the  given  specific  gravity .f 

Sugar  has  been  analyzed  by  several  chemists;  the  following  Table  exhibits  some  of 
Iheir  results : — 


Gay  Lussac 
and  Thenard. 

Berzelius. 

Prout. 

Ure. 

Oxygen,      -    - 

Carbon,    -    -     - 
Hydrogen,  -    - 

56-63 

42-47 

6-90 

49-856 

43-265 

6-875 

53-35 

39-99 

6-66 

50-33 

43-38 

6-29 

in  100. 

Of  the  mpar  cane,  and  the  extraction  of  sugar  from  it. — Humboldt,  after  the  most 
elaborate  historical  and  botanical  researches  in  the  New  World,  has  arrived  at  the  con- 
clusion, that  before  America  was  discovered  by  the  Spaniards,  the  inhabitants  of  that 
continent  and  the  adjacent  islands  were  entirely  unacquainted  with  the  sugar  can^,  with 
any  of  our  corn  plants,  and  with  rice.     The  progressive  diffusion  of  the  cane  has  been 
thus  traced  out  by  the  partisans  of  its  oriental  origin.     From  the  interior  of  Asia  it  wat 
transplanted  first  into  Cyprus,  and  thence  into  Sicily,  or  possibly  by  the  Saracens  di- 
rectly into  the  latter  island,  in  which  a  large  quantity  of  sugar  was  manufactured  iu 
the  year  1 148.    Lafitau  relates  the  donation  made  by  William  the  Second,  king  of  Sicily, 
to  the  convent  of  St  Benoit,  of  a  mill  for  crushing  sugar  canes,  along  with  all  its  priv- 
il^es,  workmen,  and  dependencies:   which  remarkable  gift  bears  the  date  of  1166. 
According  to  this  author,  the  sugar  cane  must  have  been  imported  into  Europe  at  the 
period  of  the  Crusades.     The  monk  Albertus  Aquensis,  in  the  description  which  he  has 
given  of  the  processes  employed  at  Acre  and  at  Tripoli  to  extract  sugar,  says,  that  in 
the  Holy  Land,  the  Christian  soldiers  being  short  of  provisions,  had  recourse  to  sugar 
canes,  which  they  chewed  for  subsistence.     Toward  the  year  1420,  Dom  Henry,  regent 
of  Portugal,  caused  the  sugar  cane  to  be  imported  into  Madeira  from  Sicily.     This  plant 
succeeded  perfectly  in  Madeira  and  the  Canaries ;  and  until  the  discovery  of  America 
these  islands  supplied  Europe  with  the  greater  portion  of  the  sugar  which  it  consumed. 
The  cane  is  said  by  some  to  have  passed  from  the  Canaries  into  the  Brazils;  but 
by  others,  from  the  coast  of  Angola  in  Africa,  where  the  Portuguese  had  a  sugar  colony. 
It  was  transported  in  1506,  from  the  Brazils  and  the  Canaries,  into  Hispaniolaor  Haytij 
where  several  crushing-mills  were  constructed  in  a  short  time.     It  would  appear, 

*  ^?  author,  in  minutes  of  evidence  of  Molasses  Committee  of  the  House  of  Commons,  1831,  p.  143L 
t  This  rule  was  annexed  to  an  extensive  table,  representing  the  quantity  of  sugar  per  gallon  corre. 
spondmg  to  the  specific  gravities  of  the  syrup,  constructed  by  the  author  of  the  Excise,  in  subserviency 
to  the  Bee^root  Kll.  "' 


moreover,  from  the  statement  of  Peter  Martyr,  in  the  third  book  of  his  first  Decade, 
written  during  the  second  expedition  of  Christopher  Columbus,  which  happened  between 
1493  and  1495,  that  even  at  this  date  the  cultivation  of  the  sugar  cane  was  widely  spread 
in  St.  Domingo.  It  may  therefore  be  supposed  to  have  been  introduced  here  by  Co- 
lumbus himself,  at  his  first  voyage,  along  with  other  productions  of  Spain  and  the  Canaries, 
and  that  its  cultivation  had  come  into  considerable  activity  at  the  period  of  his  second 
expedition.  Towards  the  middle  of  the  17th  century,  the  sugar  cane  was  imported  into 
Barbadoes  from  Brazil,  then  into  the  other  English  West  Indian  possessions,  into  the 
Spanish  Islands  on  the  coast  of  America,  into  Mexico,  Peru,  Chile,  and,  last  of  all,  into 
the  French,  Dutch,  and  Danish  colonies. 

The  sugar  cane,  jirundo  saccharifera,  is  a  plant  of  the  graminiferous  family,  which 
varies  in  height  from  8  to  10,  or  even  to  20  feet.  Its  diameter  is  about  an  inch  and  a 
half;  its  stem  is  dense,  brittle,  and  of  a  green  hue,  which  verges  to  yellow  at  the  approach 
of  maturity.  It  is  divided  by  prominent  annular  joints  of  a  whitish-yellow  color,  the  plane 
of  which  is  perpendicular  to  the  axis  of  the  stem.  These  joints  are  placed  about  3 
inches  apart ;  and  send  forth  leaves,  which  fall  off  with  the  ripening  of  the  plant.  The 
leaves  are  3  or  4  feet  long,  flat,  straight,  pointed,  from  1  to  2  inches  in  breadth,  of  a  sea- 
green  tint,  striated  in  their  length,  alternate,  embracing  the  stem  by  their  base.  They 
are  marked  along  their  edges  with  almost  imperceptible  teeth.  In  the  11th  or  12th 
month  of  their  growth,  the  canes  push  forth  at  their  top  a  sprout  7  or  8  feet  in  height, 
nearly  half  an  inch  in  diameter,  smooth,  and  without  joints,  to  which  the  name  arrow  is 
given.  This  is  terminated  by  an  ample  panicle,  about  2  feet  long,  divided  into  several 
knotty  ramifications,  composed  of  very  numerous  flowers,  of  a  while  color,  ajvetalous, 
and  furnished  with  3  stamens,  the  anthers  of  which  are  a  little  oblong.  The  roots  of 
the  sugar  cane  are  jointed  and  nearly  cylindrical;  in  diameter  they  are  about  one 
twelfth  of  an  inch ;  in  their  utmost  length  1  foot,  presenting  over  their  surface  a  few 

short  radicles. 

The  stem  of  the  cane  in  its  ripe  state  is  heavy,  very  smooth,  brittle,  of  a  yellowish- 
violet,  or  whitish  color,  according  to  the  variety.  It  is  filled  with  a  fibrous,  Spongy, 
dirty-white  pith,  which  contains  very  abundant  sweet  juice.  This  juice  is  elaborated 
separately  in  each  internodary  portion,  the  functions  of  which  are  in  this  respect  inde- 
pendent of  the  portions  above  and  below.  The  cane  may  be  propagated  by  seeds  of 
buds  with  equal  facility;  but  it  is  usually  done  by  cuttings  or  joints  of  proper  lengths, 
from  15  to  20  inches,  in  proportion  to  the  nearness  of  the  joints,  which  are  generally 
taken  from  the  tops  of  the  canes,  just  below  the  leaves. 

There  are  several  varieties  of  the  sugar-cane  plant.  The  first,  and  longest  known,  if 
the  Creole,  or  common  sugar  cane,  which  was  originally  introduced  at  Madeira.  It 
grows  freely  in  every  region  within  the  tropics,  on  a  moist  soil,  even  at  an  elevation  of 
3000  feet  above  the  level  of  the  sea.  In  Mexico,  among  the  mountains  of  Caudina- 
Masca,  it  is  cultivated  to  a  height  of  more  than  5000  feet.  The  quantity  and  quality  of 
sugar  which  it  yields,  is  proportional  to  the  heat  of  the  place  where  it  grows,  provided  it 
be  not  too  moist  and  marshy. 

The  second  variety  of  this  plant  is  the  Otaheilan  cane.  It  was  introduced  mto  the 
West  Indies  about  the  end  of  the  18th  century.  This  variety,  stronger,  taller,  with 
longer  spaces  between  the  joints,  quicker  in  its  growth,  and  much  more  productive  in 
susar,  succeeds  perfectly  well  in  lands  which  seem  too  much  impoverished  to  grow  the 
ordinary  cane.  It  sends  forth  shoots  at  temperatures  which  chill  the  growth  and  develop- 
ment of  the  Creole  plant.  Its  maturation  does  not  take  more  than  a  year,  and  is  accom- 
plished sometimes  in  nine  months.  From  the  strength  of  its  stem,  and  the  woodiness  of 
its  fibres,  it  better  resists  the  storms.  It  displays  a  better  inflorescence,  weighs  a  third 
more,  affords  a  sixth  more  juice,  and  a  fourth  more  sugar,  than  the  common  variety.  Its 
main  advantage,  however,  is  to  yield  four  crops  in  the  same  time  that  the  creole  cane 
yields  only  three.  Its  juice  contains  less  feculency  and  mucilage,  whence  its  sugar  is 
more  easily  cr^'stallized,  and  of  a  fairer  color. 

Besides  these  two  varieties,  another  kind  is  described  by  Humboldt  and  Bonpland, 
under  the  name  of  the  violet  sugar-cane,  for  its  haum  and  leaves  are  of  this  color.  It 
was  transported  from  Batavia  in  1782.  It  flowers  a  month  sooner  than  the  rest,  that 
is,  in  August,  but  it  yields  less  solid  sugar,  and  more  liquid,  both  of  which  have  a  violet 
tint. 

In  saying  that  the  cane  may  be  propagated  by  seeds  as  well  as  buds,  we  must  remark 
that  in  all  the  colonies  of  the  New  World,  the  plant  flowers,  indeed,  but  it  then  sends 
forth  a  shoot  (arrow),  that  is,  its  stem  elongates,  and  the  seed-vessel  proves  abortive. 
For  this  reason,  the  bud-joints  must  there  be  used  for  its  propagation.  It  grows  to  seed, 
however,  in  India.  This  circumstance  occurs  with  some  other  plants,  which,  when  pro- 
pagated by  their  roots,  cease  to  yield  fertile  seeds ;  such  as  the  banana,  the  bread-fruit, 
the  lily,  and  the  tulip. 

In  the  proper  season  for  planting,  the  ground  is  marked  out  by  a  line  into  rows  three 
or  four  feet  asunder,  in  which  rows  the  canes  are  planted  about  two  feet  apart.    The 


r58 


SUGAR. 


f 


!l    !  lll^V/  ^ir^^^  "'**'.  P'®''^^  ""^  ^^"^  60  or  70  feet  broad,  learing  spaces  of 
about  20  feet,  for  the  convenience  of  passage,  and  for  the  admission  of  sun  and  air 
between  the  stems.     Canes  are  usuaUy  planted  in  trenches,  about  6  or  8  inches  deep, 
made  with  the  hand-hoe,  the  raised  soil  being  heaped  lo  one  side,  for  covering-in  tht 
WrLTifJ  A^   •  *^\^°^^*  ^  negro  drops  the  number  of  cuttings  intended  to  be 
IZf.  .kA-11  ^^if*"^  ^k";?  Pf  ^°""^,.by  other  negroes.     The  earth  is  then  drawn 
about  the  hillocks  with  the  hoe.     This  labor  has  been,  however,  in   many   places 
better  and  more  cheaply  performed  by  the  plough ;   a  deep  furrow  being  made,  into 
which  the  cuttings  are  regularly   planted,  and   the  mould   then  properly  turned  in. 
!L  M  if '*""?    »''  ***  }^  afterwards  kept   clear  by  the  horse-hoe,  the  rows  of  canes 
should  be  0  feet  asunder,  and  the  hillocks  2$  feet  distant,  with  only  one  cane  left  in 
one  hillock.     After  some  shoots  appear,  the  sooner  the  horse-hoe  is  used,  the  more  wiU 
the  plants  thrive  by  keeping  the  weeds  under,  and  stirring  up  the  soil.     Plant-canes 
01  the  first  growth  have  been  known  to  yield,  on  the  brick-mould  of  Jamaica,  in  very 
fine  seasons  2i  tons  of  sugar  per  acre.    The  proper  season  for  planting  the  cane  slips, 
containing    he  buds,  namely,  the  top  part  of  the  cane,  stripped  of  its  leaves,  and 
the  two  or  three  upper  joints,  is  m  the  interval  between  August  and  the  beginning  of 
^nnlfJ?  tn'*>,  ^*''?K^  ^^  the  autumnal  weather,  the  young  plants  become  luxuriant 
enough  to  shade  the  ground  before  the  dry  season  sets  in;  thereby  keeping  the  roots 
cool  and  moderately  moist.     By  this  arrangement  the  Creole  canes  are  ripe  for  the  miU 
in  the  beginning  of  the  second  year,  so  as  to  enable  the  manaser  to  finish  his  crop  early 

^J.l^^:r  I  '^  ""u  ^""f  ^l'  ^"■°'"  '"^  ^^^  *^°^«"»^^  ^^*^  Pl«"ting  canes  at  an  improper 
season  of  the  year,  whereby  his  whole  system  of  operations  becomes  disturbed,  and,  in  « 
certain  degree,  abortive.  >  *    ^ 

The  withering  and  fall  of  a  leaf  aflford  a  good  criterion  of  the  maturity  of  the  cane- 
joint  to  which  It  belonged ;  so  that  the  eight  last  leafless  joints  of  two  canes,  which  are 
cut  the  same  day  have  e:cactly  the  same  age  and  the  same  ripeness,  though  one  of  the 
canes  be  15  and  the  other  only  10  months  old.  Those,  however,  cut  towaAs  the  end  of 
the  dry  season,  before  the  rains  begin  to  fall,  produce  better  sugar  than  those  cut  in  the 
rainy  season  as  they  are  then  somewhat  diluted  with  watery  juice,  and  require  more  eva- 
poration  to  form  sugar.  It  may  be  reckoned  a  fair  averaee  product,  when  one  pound  of 
sugar  is  obtained  from  one  gallon  (English)  of  juice.         -    *-  '  r-        u. 

Rattoons  (a  word  corrupted  from  rejettons)  are  the  sprouts  or  suckers  that  spring  from 
the  roots  or  stoles  of  the  canes  that  have  been  previously  cut  for  sugar.  They  are 
thTrr"Jf  "PJ  '"^  12  months  ;  but  canes  of  the  first  growth  are  called  plant-canes,  being 
Innir  ntvl?^^  •  '^^  ^"^'"^^  '""-'"^^  "''  ^^™^  P^^^^^  ^^  ^he  grouud,  and  require  I 
lrP^.,7n  ^«*>""?;h/™  to  maturity.    The  first  yearly  return  from  the  roofs  that 

nn  ,.  nrT^"'  T  fh  •     ^''^  rf  toons;  the  second  year's  growth,  second  rattoons;  and  so 
on,  according  to  their  aije.     Instead  of  stocking  up  his  rattoons,  holing,  and  planting 

^^.^k\VZ''^'"''I^T^'''^'\^^  ^i°'"^  *°  continue  in  the 'ground/ and  SenJ 
himself,  as  the  cane  fields  become  thin  and  impoverished,  with  supplying  the  vacant  nlacei 
With  fresh  plants.  By  these  means,  and  with  the  aid  V  manure,\he  pr^uce  of  su 'S 
per  acre,  if  not  apparently  equal  to  that  from  plant-canes,  gives  perhaps  in  the  Ion-  run 
as  great  returns  to  the  owner,  considering  the  relative  proportion  of  the  labor  and  expense 
attending  the  different  systems.  The  common  yielding  on  proper  land,  such  as  the  rS 
soil  of  Trelawney,  m  Jamaica,  is  7  hogsheads,  of  1 6  cwts.  each,  to  10  acres  of  rattoong  cZ 
annually ;  and  such  a  plantation  lasts  from  6  to  10  years.  *«iioon8cui 

When  the  planted  canes  are  ripe,  they  are  cut  close  above  the  ground,  by  an  oblique 
sec  ion,  into  lengths  of  3  or  4  feet,  and  transported  in  bundles  to  the  mill-house      Iflhe 
roots  be  then  cut  ofi;  a  few  inches  below  the  surface  of  the  soil,  and  covered  up  with  fine 
mould,  they  will  push  forth  more  prolific  oflsets  or  rattoons,  than  when  left  projectinc  in 
he  common  way.  ^  "jc^^wug  la 

The  recent  researches  of  the  eminent  French  chemist,  M.  Casaseca,  upon  cane  iuice 

«.  fST"*K  '  •  ^"^'r  ^r""^  demonstrated  clearly  the  enormous  loss  which  sugar-plan tew 

suffer  by  the  imperfection  of  their  manufacturing  processes.     His  results  confirm  those 

previously  obtained  by  M.  Peligot  in  Paris,  and^  Ihow  that  cane  juice  evatrTtedi^ 

\acuo  at  the  atmospheric  temperature  yields,  in  100  parts,—  i^rateu  la 

Crystalline  white  sugar  -  ,  .       20'94 

Water  -  -  .  .  -      78'80 

Mineral  substances        -  .  .  .        q.-,a 

Organic  matter,  different  from  sugar  -        0*12 

The  cane  from  which  the  above  juice  was  drawn  is  called  canade  la  tierra  in  Cuba. 
The  juice  of  the  Otaheite  cane  ,s  identical  with  the  preceding.  But  the  proportions  o^ 
Igneous  fibres  m  the  two  canes  are  very  different ;  that  of  la  tierra  containing  according 
to  M.  Casaseca,  16-4  per  cent,  while  that  of  Otaheite  contains  only  10.  (Hher  canef 
however,  differ  in  this  respect  considerably  from  these  two  varieties.  The  averaS 
quantity  of  grained  sugar  obtained  from  cane  juice  in  our  colonial  plantations  is  proba  Wy 
not  more  than  one-third  of  the  quantity  of  crystalline  sugar  in  the  juice  which  they  boif 


SUGAR. 


759 


The  following  analysis  of  cane  juice,  performed  by  a  French  chemist,  was  given  me 
by  Mr.  Forstall  of  New  Orleans.  In  10  English  gallons,  of  231  cubic  inches  each  of 
juice  making  8i°  Baum6,  there  are  6f  ounces  English  of  salts,  which  consist  of— 

Sulphate  of  potash  -        -         17*840  grammes— 16'44  grains  each. 

Phosphate  of  potash  -         -         16-028 

C^lorure  of  potassium       -        -  8"355 

Acetate  of  potash      -        •        -        63*760 

Acetate  of  lime  -        -        -        36*010 

Gelatinous  silica       ...        15*270 

167*153  ■«=  5*57  ounces  avoirdupois 
To  the  large  proportion  of  deliquescent  saline  matter,  of  which  one  half  he  says 
remains  in  the  sugar,  the  analyst  ascribes  very  properly  the  deliquescence  and  dete- 
rioration of  the  sugar  when  kept  for  some  time  or  transported.  It  was  probably  the 
juice  of  the  cane  grown  in  the  rich  alluvial  soil  of  Louisiana,  and  therefore  more  abun- 
dant in  saline  matter  than  the  average  soil  of  our  West  India  Islands.  The  Demerara 
cane-juice  has  perhaps  the  above  saline  constitution,  as  it  suffers  much  loss  of  weight 
by  drainage  in  the  home  voyage. 

OF  SUGAR  MILLS. 

The  first  machines  employed  to  squeeze  the  canes,  were  mills  similar  to  those  which 
serve  to  crush  apples  in  some  cider  districts,  or  somewhat  like  tan-mills.  In  the  centre 
of  a  circular  area  of  about  7  or  8  feet  in  diameter,  a  vertical  heavy  wheel  was  made  to 
revolve  on  its  edge,  by  attaching  a  horse  to  a  cross  beam  projecting  horizontally  from 
it  and  making  it  move  in  a  circular  path.  The  cane  pieces  were  strewed  on  the  some- 
what concave  bed  in  the  path  of  the  wheel,  and  the  juice  expressed  flowed  away 
through  a  channel  or  gutter  in  the  lowest  part  This  machine  was  tedious  and  unpro- 
ductive. It  was  replaced  by  the  vertical  cylinder-mill  of  Gonzales  de  Velosa ;  which 
has  continued  till  modern  times,  with  little  variation  of  external  form,  but  is  now  gen- 
erally superseded  by  the  sugar-mill  with  horizontal  cylinders. 

SpeciJicatioH  of,  and  Observations  on  the  Construction  and  Use  of  the  best 

Horizontal  Sugar-mill. 
Fly.  1385.     Front  elevation  of  the  entire  mill.     Fig.  1386.     Horizontal  plan.     Fig. 
1387.    End  elevation.     Fig.  1388.    Diagram,  showing  the  dispositions  of  the  feeding 
and  delivering  rollers,  feeding  board,  returner,  and  delivering  board. 

Fig.  1385.  a,  a,  solid  foundation  of  masonry;  b,  b,  bed  plate:  o,  c,  headstocks  or 
standards;  d,  main  8haft(seenonly in/^.  1386);  b, intermediate  shaft ;  f,  f,  plummer- 
blocks  of  main  shaft  d  (seen  only  \v\jig.  1386);  h  driving  pinion  on  the  fly-wheel  shaft 
of  engine ;  i,  first  motion  mortise  wheel,  driven  by  the  pinion ;  k,  second  motion  pinion, 
on  the  same  shaft;  l,  second  motion  mortise-wheel,  on  the  main  shaft;  m,  brays  of 
wood,  holding  the  plummer-blocks  for  shaft  d  ;  n,  wrough^iron  straps  connecting  the 
brays  of  the  standards  c,  c;  o,  o.  regulating  screws  for  the  brays;  p,  top  roller  and 
gudgeons;  q  and  k,  the  lower  or  feeding  and  delivering  rollers;  s,  clutch  for  the  con- 
nection of  the  side  of  lower  rollers  q  and  r,  to  the  main  shaft  (seen  only  mjig.  1386) ; 
T,  T,  the  drain  gutters  of  the  mill-bed  (seen  only  in^^.  1386). 

The  same  letters  of  reference  are  placed  respectively  on  the  same  parts  of  the  mill 
in  each  oijigs.  1385,  1386,  and  1387. 

The  relative  disposition  of  the  rollers  is  shown  in  the  diagram,^.  1388,  in  which  a 
is  the  top  roller;  b,  the  feeding  roller;  c,  the  delivering  roller;  d,  the  returner;  e,  the 
feed  board ;  f,  the  delivering  board. 

The  rollers  are  made  2^  inches  to  2^  inches  thick,  and  ribbed  in  the  centre.  The 
feeding  and  delivering  rollers  have  small  flanges  at  their  ends  (as  shown  in  Jig  1385) 
between  which  the  top  roller  is  placed ;  these  flanges  prevent  the  pressed  canes  or  begass 
from  working  into  the  mill-bed.  The  feeding  and  top  rollers  are  generally  fluted,  and 
sometimes  diagonally,  enabling  them  the  better  to  seize  the  canes  from  the  feed-board. 
It  is,  however,  on  the  whole,  considered  better  to  flute  the  feeding  roller  onlv,  leaving 
the  top  and  delivery  rollers  plane;  when  the  top  roller  is  fluted,  it  should  be  very 
slightly,  for,  after  the  work  of  a  few  weeks,  its  surface  becomes  sufficiently  rough  to- 
bito  the  canes  effectively.  The  practical  disadvantage  of  fluting  the  delivering  rollers; 
is  in  the  groves  carrying  round  a  portion  of  liquor,  which  is  speedily  absorbed  by  the 
spongy  begass,  as  well  as  in  breaking  the  begass  itself,  and  thus  causing  great  waste. 

The  feed  board  is  now  generally  made  of  cast  iron,  and  is  placed  at  a  considerable 
inclination,  to  allow  the  canes  to  slip  the  more  easily  down  to  the  rollera  The  returner 
is  also  of  cast  iron,  serrated  on  the  edge,  to  admit  the  free  flowing  of  the  liquor  to  the 
mill-bed.  The  concave  returner,  formerly  used,  was  pierced  with  holes  to  drain  off  the 
liquor,  but  it  had  the  serious  disadvantage  of  the  holes  choking  up  with  the  splinters 
of  the  cane,  and  has  therefore  been  discarded.  The  delivering  board  is  of  cast  iron, 
fitted  close  to  the  roller,  to  detach  any  begass  that  may  adhere  to  it,  and  otherwise 
mix  with  the  liquor. 


reei 


SUGAR. 


SUGAR. 


761 


r 


.  J^^.^'^k'^™',,®"?"*"'  Cayenne,  and  the  alluvial  district  of  Trinidad,  it  is  oraal  to 
ittacii  to  the  mill  a  liquor-pump,  with  two  barrels  and  three  adjustments  of  stroke.    Thit 


ffl! 


■M 


b  worked  from  the  gudgeon  of  the  top  roller.     In  action,  the  liquor  from  the  eutter  of 

whicT  eads  toThVt  -fi'  '''''"^  ''  ^'^  ^T  *"^  '^'  '^^'^  by  ?he  pump  to  thTgutti 
rarsinrDfnes  arVl  f  S  ""'.f^^^^'''  ?"«»»  P"^PS  have  brass  barrels  and  copper  dis- 
charging pipes,  are  worked  with  a  very  slow  motion,  and  require  to  be  carefully  adiusted 

^«.ffl?"^"  f^  ''^■^T'"  .'^  ^"  '""'''^  ^^^'^h'  ^ithou[  such  p'ecaution% Slher  not drall 
JuXuZi^y  mill,  the  feeding  roller  is  kept  about  half  an  inch  distant  from  the  upper 


•iher  as  little  as  possible.    They  are  taken  in  by  the  feed  rollers,  which  split  and  sHgh^ 
press  them ;  the  liquor  flows  down,  and,  the  returner  guiding  the  canes  between  ine  wp 


and  delivering  rollers,  they  receive  the  final  pressure,  and  are  turned  out  on  the  mill-floor, 
while  the  liquor  runs  back  and  falls  into  the  mill-bed.  The  begass,  then  m  the  state  of 
pithy  adhering  to  the  skin  of  the  cane,  is  tied  up  in  bundles,  and  after  being  exposed  a 
short  time  to  the  sun,  is  finally  stored  in  the  begass-house  for  fuel.  By  an  important 
improvement  in  this  stage  of  the  process,  recently  introduced,  the  begass  is  carried  to  the 
begass-house  by  a  carrier  chain,  worked  by  the  engine. 

The  relative  merits  of  horizontal  and  vertical  sugar-mills  on  this  construction  may  be 
thus  slated:— The  horizontal  mill  is  cheaper  in  construction,  and  is  more  easily  fixed; 
the  process  of  feeding  is  performed  at  about  one  half  of  the  labor,  and  in  a  much  supe- 
rior manner;  the  returner  guides  the  canes  to  receive  the  last  pressure  more  perfectly; 
and  the  begass  is  not  so  much  broken  as  in  the  vertical  mill,  but  left  tolerably  entire,  so 
as  to  be  tied,  dried,  and  stored,  with  less  trouble  and  waste. 

The  vertical  mill  has  a  considerable  advantage,  in  being  more  easily  washed ;  and  it 
can  be  readily  and  cheaply  mounted  in  wooden  framing ;  but  the  great  labor  of  feeding 
the  vertical  mill  renders  it  nearly  inapplicable  to  any  higher  power  than  that  of  about 
ten  horses.  In  situations  where  the  moving  power  is  a  windmill,  or  a  cattle-gin,  the 
vertical  mill  may  be  preferred. 

The  scale  of  produce  of  such  mills  varies  according  to  the  climate  and  soil.  In  Deme- 
rara,  a  well-constructed  engine  and  mill  will  produce  about  100  gallons  of  liquor  per 
hour  for  each  horse  power. 

The  dimensions  of  the  most  approved  horizontal  mills  are  these : — 


Horae-powcr  of  Engine. 

Leng:th  of  Rollers. 

Diameter  of  Rollers. 

8 
10 

12 

ft.         in, 
4           0 
4            6 

4           8       , 

inches, 
25 
27 
28 

The  surface  speed  of  the  rollers  is  3*4  or  3*6  feet  per  minute ;  and  to  provide  for  th« 
varying  resistance  arising  from  irregular  feeding,  or  the  accidental  crossing  of  the  canes, 
by  which  the  engine  is  often  brought  up  so  suddenly  as  to  break  the  fly-wheel  shaft,  it  is 
necessary  to  make  both  the  shaft  and  the  fly-wheel  of  unusual  strength  and  weight. 

Sugar  is  manufactured  in  the  East  Indies  by  two  distinct  classes  of  persons ;  the  ryoiSf 
who  raise  the  sugar  cane,  extract  its  juice,  and  inspissate  it  to  a  sirupy  consistence;  and 
the  goldarsy  who  complete  the  conversion  into  sugar. 

The  ryots  are  the  farmers,  or  actual  cultivators  of  the  soil ;  but,  properly  speaking, 
they  are  merely  peasants,  toiling  under  oppressive  landlords,  and  miserably  ^  poor. 
After  they  cut  the  canes,  they  extract  the  juice  by  one  ci  other  of  the  rude  mills  or 
mortars  presently  to  be  described,  and  boil  it  down  to  an  entire  mass,  which  is  gene- 
rally called  gooTf  without  making  any  attempt  to  clarify  it,  or  separate  the  granular 
sugar  from  the  uncrystallizable  molasses.    This  goor  is  of  various  qualities ;  one  of 


762 


SUGAR. 


SUGAR. 


763 


i  i« 


1389 


1 

1 

1 

which,  in  roost  common  nse  for  making  sugar,  is  known  amongst  the  English  settlert 
under  the  name  of  jaggery.  There  is  a  caste  in  Ceylon,  called  jaggeraros,  whc 
make  sugar  from  the  produce  of  the  Caryota  t*re»w,  or  Kitui  tree ;  and  the  sugar  if 
styled  jaggery.  Sugar  is  not  usually  made  in  Ceylon  from  the  sugar  cane ;  but  either 
from  the  juice  of  the  Kitul,  from  the  Cocos  nuciferaf  or  the  Borassus  Jlabelliformis  (the 
Palmyra  tree.) 
Several  sorts  of  cane  are  cultivated  in  India. 

The  Cadjoolee  (fig.  1389)  is  a  purple-colored  cane ;  yields  a  sweeter  and  richer  juice 
than  the  yellow  or  light-colored,  but  in  less  quantities,  and  is  harder  to  press.  It  ?row8 
in  dry  lands.  When  eaten  raw,  it  is  somewhat  dry  and  pithy  in  the 
mouth,  but  is  esteemed  very  good  for  making  sugar.  It  is  not  known 
to  the  West  India  planter.  The  leaves  rise  from  a  point  6  feet  above 
the  ground.  An  oblique  and  transverse  section  of  the  cane  is  repre- 
sented by  the  parts  near  the  bottom  of  the  figure. 

The  Pooree  is  a  light-colored  cane,  yellow,  inclining  to  white,  deeper 
yellow  when  ripe  and  on  rich  ground.  West  India  planters  consider 
it  the  same  sort  as  one  of  theirs.  It  is  softer  and  more  juicy  than  the 
preceding,  but  the  juice  is  less  rich,  and  produces  a  weaker  sugar.  It 
requires  seven  parts  of  pooree  juice  to  make  as  much  goor  as  is  pro- 
duced from  six  of  the  cadjoolee.  Much  of  this  cane  is  brought  to  the 
Calcutta  market,  and  eaten  raw. 

The  CuUorah  thrives  in  swampy  lands,  is  light-colored,  and  grows 
to  a  great  height.  Its  juice  is  more  watery,  and  yields  a  weaker  sugar 
also  than  the  cadjoolee.  However,  since  much  of  Bengal  consists  of 
low  grounds,  and  since  the  upland  canes  are  apt  to  suffer  from  drought, 
it  deserves  encouragement  in  certain  localities. 

It  is  only  large  farms  that  cut  an  acre  of  cane  in  a  year ;  one  mill, 
therefore,  and  one  set  of  the  implements  used  in  inspissating  the 
juice,  although  very  rude  and  simple,  serve  for  several  farms,  and 
generally  belong  to  some  wealthy  man,  who  lets  them  out  for  hire  to 
his  poorer  neighbors,  the  whole  of  whom  unite  to  clear  each  other*i 
fields  by  turns ;  so  that  though  many  people  and  cattle  are  employed 
jT^f  |IV\  at  one  of  these  miserable  sets  of  works,  very  few  indeed  are  hired* 
and  the  greater  part  of  the  labor  is  performed  by  the  common  stock  of 
the  farms. 

The  inspissated  juice,  or  extract  of  cane,  called  by  the  natives  goor 
is  of  two  kinds ;   one  of  which  may  be  termed  cake  extract,  and  the 
other  pot  extract ;  both  being  often  denominated  jaggery,  as  above 
stated,  by  the  English  residents. 
One  third  of  an  acre  of  good  land  in  the  southern  districts,  is  reckoned  by  the 

farmers  to  produce  18,891 
pounds  of  cane,  and  1,169 
pounds  of  pot  extract.  Its 
produce  in  cake  extract  is 
about  952  pounds. 

I  shall  now  describe  the 
primitive  rude  mill  and  boi- 
ler used  in  preparing  the 
extract  of  sugar  cane,  and 
which  are  usually  let  to  the 
ryots  by  the  day.  The  mill 
in  Dinajpur,/g.  1080,  is  on 
the  principle  of  a  pestle  and 
mortar.  The  pestle,  how- 
ever,  does  not  beat  the 
canes,  but  is  rubbed  against 
them,  as  is  done  in  DHiny 
chemical  triturations ;  and 
the  moving  force  is  two 
oxen.  The  mortar  is  gene- 
rally a  tamarind  tree,  one 
end  of  which  is  sunk  deep 
in  the  ground,  to  give  it 
firmness.  The  part  pro- 
,  ^       , .  .         ,  jecting,   a,  a,  a.  a,  mar 

be  about  two  feet  high,  and   a  foot  and  a  half  in  diameter ;    and  in  the  upper  end 
»  hollow  is  cut,  like  the  small  segment  of  a  sphere.     In  the  centre  of  this,  a 


channel  descends  a  little  way  perpendicularly,  and  then  obliquely  to  one  side  of  the  mortar, 
80  that  the  juice,  as  squeezed  from  the  cane,  runs  oflT,  by  means  of  a  spout  6,  into 
a  strainer  c,  through  which  it  falls  into  an  earthen  pot,  that  stands  in  a  hole 
d,  under  the  spout.  The  pestle  e,  is  a  tree  about  18  feet  in  length,  and  1  foot  in 
diameter,  rounded  at  its  bottom,  which  rubs  against  the  mortar,  and  which  is  se- 
cured in  its  place  by  a  button  or  knob,  that  goes  into  the  channel  of  the  mortar. 
The  moving  force  is  applied  to  a  horizontal  beam  /,  about  16  feet  in  length,  which 
turns  round  about  the  mortar,  and  is  fastened  to  it  by  a  bent  bamboo^  b.  It  is 
suspended  from  the  upper  end  of  the  pestle  by  a  bamboo  g,  which  has  been  cut 
with  part  of  the  root,  in  which  is  formed  a  pivot  that  hangs  on  the  upper  point  of  the 
pestle.  The  cattle  are  yoked  to  the  horizontal  beam,  at  about  ten  feet  from  the  mortar, 
move  round  it  in  a  circle,  and  are  driven  by  a  man,  who  sits  on  the  beam,  to  increase 
the  weight  of  the  triturating  power.  Scarcely  any  machine  more  miserable  can  be  con- 
ceived ;  and  it  would  be  totally  ineffectual,  were  not  the  cane  cut  into  thin  slices.  This 
is  a  troublesome  part  of  the  operation.  The  grinder  sits  on  the  ground,  having  before 
him  a  bamboo  stake,  which  is  driven  into  the  earth,  with  a  deep  notch  formed  in  its  up- 
per end.  He  passes  the  canes  gradually  through  this  notch,  and  at  the  same  time  cuts 
oflf  the  slices  with  a  kind  of  rude  chopper. 

The  boiling  apparatus  is  somewhat  better  contrived,  and  is  placed  under  a  shed, 
though  the  mill  is  without  shelter.  The  fireplace  is  a  considerable  cavity  dug  in  the 
ground,  and  covered  with  an  iron  boiler  p,fig.  1391.  At  one  side  of  this,  is  an  opening 
q,  for  throwing  in  fuel ;  and  opposite  to  this,  is  another  opening,  which  communicates 


1391 


with  the  horizontal  flue.  This  is  formed  by  two  parallel  mud  walls  r,  r,  a,  s,  about  20 
feet  long,  2  feet  high,  and  18  inches  distant  from  each  other.  A  row  of  eleven  earthen 
boilei  s  t,  is  placed  on  these  walls,  and  the  interstices  «,  are  filled  with  clay,  which 
completes  the  furnace-flue,  an  opening  r,  being  left  at  the  end,  for  giving  vent  to  the 
smoke. 

The  juice,  as  it  comes  from  the  mill,  is  first  put  into  the  earthen  boiler  that  is  most 
distant  from  the  fire,  and  is  gradually  removed  from  one  boiler  to  another,  until  it  reaches 
the  iron  one,  where  the  process  is  completed.  The  fireplace  is  manifestly  on  the  same 
model  as  the  boiler  range  in  the  West  Indies,  and  may  possibly  have  suggested  it,  since 
the  Hindostan  furnace  is,  no  doubt,  of  immemorial  usage.  The  execution  of  its  parts  is 
very  rude  and  imperfect.  The  inspissated  juice  that  can  be  prepared  in  24  hours  by  such 
a  mill,  with  16  men  and  20  oxen,  amounts  to  no  more  than  476  lbs. ;  and  it  is  only  in  the 
southern  parts  of  the  district,  where  the  people  work  night  and  day,  that  the  sugar-works 
are  so  productive.  In  the  northern  districts,  the  people  work  only  during  the  day,  and 
inspissate  about  one  half  the  quantity  of  juice.  The  average  daily  make  of  a  AVest  India 
sugar-house,  is  from  2  to  3  hogsheads,  of  16  cwts.  each. 

The  Indian  manufacturers  of  sugar  purchase  the  above  inspissated  juice  or  goor  from 
the  farmers,  and  generally  prefer  that  of  a  granular  honey  consistence,  which  is  offered 
for  sale  in  pots.  As  this,  however,  cannot  conveniently  be  brought  from  a  distance,  some 
of  the  cake  kind  is  also  employed.  The  boilers  are  of  two  sizes ;  one  adapted  for 
making  at  each  operation  about  ten  cwts. ;  the  other,  about  eight  and  a  half.  The  latter 
is  the  segment  of  a  sphere,  nine  feet  diameter  at  the  mouth ;  the  former  is  larger.  The 
boiler  is  sunk  into  a  cylindrical  cavity  in  the  ground,  which  serves  as  a  fireplace,  so 
that  its  edge  is  just  above  the  floor  of  the  boiling-house.  The  fuel  is  thrown  in  by  an 
aperture  close  to  one  side  of  the  boiler,  and  the  smoke  escapes  by  a  horizontal  chimney 
that  passes  out  on  the  opposite  side  of  the  hut,  and  has  a  small  round  aperture,  about 
ten  feet  distant  from  tb  i  wall,  in  order  to  lessen  the  danger  from  fire.  Some  manufac- 
turers have  only  one  boiler ;  others  as  many  as  four ;  but  each  boiler  has  a  separate  hut, 
in  one  end  of  which  is  some  spare  fuel;  and  in  the  other,  some  bamboo  stages,  which 
support  cloth  strainers,  that  are  used  in  the  operation.  This  hut  is  about  twenty-four 
cubits  long,  and  ten  broad  ;  has  mnC  walls,*ix  cubits  high ;  and  is  raised  about  one  cubit 
a1)ove  the  ground. 

For  each  boiler,  two  other  houses  are  required :  one  in  which  the  cane  extract  is 
separated  by  straining  from  the  molasses,  is  about  twenty  cubits  long  by  ten  wide ;  an- 
other, about  thirty  cubits  long,  by  eight  wide,  is  that  in  which,  after  the  extract  has  been 
strained,  boiled,  and  clarified,  the  treaciC  is  separated  from  the  sugar  by  an  operation  an. 
alogous  to  claying. 


764 


SUGAR. 


SUGAR. 


765 


:iil{     ., 


bef ;?  hiXleTr'^"'''''"'  ^^  ^  """^'^""'^  ^''^'''  "*'  *  ^^«  proportional  to  the  nam. 

About  960  pounds  of  pot  extract  being  divided  into  four  parts,  each  is  nut  into  a  ba< 

•  ^r"'-'  iff^^'^°>K'  ^';"^.  ^^^'  ^"^  ^^"^^  """^^^^  °^  wide-mouthV  earthen  ie^els  a3 
,s  besprinkled  with  a  htl  e  water.  These  drain  from  the  bags  about  24?  noTnds  ofl 
substance  analogous  to  West  Indian  molasses.  The  remainde?  in  the  ba-s  La  kind  of 
coarse  muscovado  sugar;  but  is  far  from  beine  so  well  drainpH  «n^  a.  i^^r  , 

»«!  that  nfthp.  Antni^r     Vk^  -yon  i     WliT-^  &"  well  arainea  and  freed  from  molasses 

as  tnat  ot  the  Antilles.  The  720  pounds  of  this  substance  are  then  put  into  a  boiler  with 
270  pounds  of  water,  and  the  mixture  is  boiled  briskly  for  n/minutes  when  180 
additional  pounds  of  water  are  added,  and  the  boiling  is  continued  for  48  mtnules  mor^ 
An  alkaline  solution  is  prepared  from  the  ashes  of  the  plantain  tree,  strewed  over  Zw 
placed  in  the  bottom  of  an  earthen  pot  perforated  with  holes.  Ninety  Sds  of  J^7r 
are  passed  through;  and  6  pounds  of  the  clear  lixivium  are  added  to  th^l^ninJ  7w^ 
whereby  a  thick  scum  is  raised  which  is  removed.  After  24  minuTe  ,  fou?  and  a  ha  J' 
pounds  of  a  kalme  solution  and  about  two  fifths  of  a  pound  of  raw  mUk,  a?e  added  • 
after  which  the  boilmg  and  skimming  are  continued  24  minutes.     This  Tust  be  repeated 

IZ/ th  '  1-  '''^"'  T't  ^"'"  r  ^""'^  ^^""^  ^^^'^''-  240  pounds  of  water  be  ng  now 
added,  the  hquor  is  to  be  poured  into  a  number  of  strainers.  These  are  ba^^  of  rn«rc! 
cotton  cloth,  in  the  form  of  inverted  quadrangular  pyramids,  each  of  whkMs  suspend^ 
from  a  frame  of  wood,  about  two  feet  square.  The  operation  of  straining  occupres^Ib^m 
96  minutes  The  strained  liquor  is  divided  into  three  parts  :  one  of  theselput  ini^  a 
boiler,  with  from  half  a  pound  to  a  pound  and  a  half  of  alkaline  solution!one  twelfth  of 
a  pound  of  milk,  and  12  pounds  of  water.  After  having  boiled  for  between  48  and  72 
minutes,  three  quarters  of  a  pound  of  milk  are  added,  and  the  liquor  rrourefin  equ^ 
portions,  into  four  refining  pots.  These  are  wide  at  the  mouth,  and  pointed  a  heff 
torn ;  but  are  not  conical,  for  the  sides  are  curved.  The  bottim  is  nerforat^  anH  thZ' 
stem  of  a  plantain  leaf  forms  a  plug  for  closing  theaperture.  The^J^^remSni^^'p'rU^^^^^ 
of  the  strained  hquor  are  managed  in  exactly  the  same  manner;  so  that  eich  reS 
pot  has  its  share  of  each  portion.  When  they  have  cooled  a  ittle,  the  refinin"To! 
IS  removed  to  the  curing-house,  and  placed  on  the  ground  for  24  hours;   next='  C 

t'l  ^''  P.w  ^  "^^  ^  ^''T'  ''}'''^  ^"PP«^^  ^^'"^  ^t  '^^^  distance  from  the^ound  A 
Tht''^^'^"^,  ""T"}  ''  Pl«^^.^"d^r  each,  to  receive  the  viscid  liquor  that  E  from 
them  In  order  to  draw  off  this  more  completely,  moist  leaves  of  the  ValisneHaTvira^ 
are  placed  over  the  mouth  of  the  pot,  to  the  thickness  of  two  inches -X?  10  or  12 
days,  these  are  removed ;  when  a  crust  of  sugar,  about  half  an  inch  in  thickness  is  found 
on  the  surface  of  the  boiled  liquor.  The  crust  being  broken  and  removeTfresV  lea^^^^^ 
are  repeatedly  added,  until  the  whole  sugar  has  formed;  which  requires  from  75  to^ 
^Tboile^.  '  '"''"''  ^'  "''^' ''  ^"''  "°^  '^'^^  ^  ^'  strained'before  it  £  putlnto 

rpl'lic^  aWye-described  operose  and  preposterous  process,  it  is  needless  to  make  any 
remarks.  While  it  is  adhered  to  with  the  tenacity  of  Hindoo  habit,  the  West  Ind^a 
has  no  reason  to  fear  the  competition  of  the  East,  in  the  manufacture  of  sugar,  provwS 
lo  sippTy.'  th^^selves  of  the  aids  which  chemical  and  mechanical  sdel^'a^eT^^ 

In  every  part  of  the  Behar  and  Putna  districts,  several  of  the  confeetionprs  nro«.«i. 
the  coarse  article  called  shukkur,  which  is  entirely^imUa?  in  ap^aranc^^^^^^  LTeriJJ 
Jamaica  sugars.  They  prepare  it  by  putting  some  of  the  thii  extract  of  suVar.™ 
into  coarse  sackcloth  bags,  and  by  laying  weigSts  on  them,  tLy  squeezrout  th^^ 

a  process  perfectly  analogous  to  that 
contemplated  in  several  English  pat- 
ents,  ' 

,  The  sugar-mill  at  Chica  Ballapur* 
IS  worked  by  a  single  pair  of  buffaloes 
or  oxen,  fig.  1392,  going  round  with 
the  lever  a,  which  is  fixed  on  the  top 
•f  the  right-hand  roller.  The  two 
rollers  have  endless  screw  heads  b, 
which  are  formed  of  4  spiral  grooves 
and  4  spiral  ridges,  cut  in  opposite 
directions,  which  turn  into  one  an- 
other, when  the  mill  is  working. 
These  rollers  and  their  heads  are  of 
one  piece,  made  of  the  toughest  and 

ts  will  not  impart  any  bad  taste  to  the  iuice  ThtTJJ^  ^^^l  ?°  ^^  K'-'  f  "'^  '"^^ 
wooden  frame  and  their  r1i<=f«n«r^r  ^  I'  f"®^  ^'^^  supported  m  a  thick  strong 
wooden  trame,  and  the  r  dis  ance  from  each  other  is  regulated  by  means  of  wedffef 
Vhich  pass  through  mortises  m  the  frame  planks,  and  a  |roove  mad?fn  a  bit  oTS 


1393 


sort  of  hard  wood,  and  press  upon  the  axis  of  one  of  the  rollers.  The  axis  of  the  other 
presses  against  the  left-hand  side  of  the  hole  in  the  frame-boards.  The  cane  juice  runs 
down  the  rollers,  and  through  a  hole  in  the  lower  frame-board,  into  a  wooden  conductor, 
which  carries  it  into  an  earthen  ix»t.  Two  long-pointed  stakes  or  piles  are  driven  into 
the  earth,  to  keep  the  mill  steady,  which  is  all  the  fixing  it  requires.  The  tinder  part  of 
the  lowermost  plank  of  the  frame  rests  upon  the  surface  of  the  ground,  which  is  chosen 
level  and  very  firm,  that  the  piles  may  hold  the  faster.  A  hole  is  dug  in  the  earth,  im  • 
mediately  below  the  spout  of  the  conductor,  to  receive  the  pot. 

The  mill  used  in  Burdwan  and  near  Calcutta,  is  simply  two  small  wooden  cylinders, 
grooved,  placed  horizontally,  close  to  each  other,  and  turned  by  two  men,  one  at  each 
end.  This  simple  engine  is  said  completely,  but  slowly,  to  express  the  juice.  It  is  very 
cheap,  the  prime  cost  not  beinar  two  rupees  ;  and  being  easily  moved  from  field  to  field, 
it  saves  much  labor  in  the  carriage  of  the  cane.  Notwithstanding  this  advantage,  so  rude 
a  machine  must  leave  a  large  proportion  of  the  richest  juice  in  the  cane-trash. 

It  is  curious  to  find  in  the  ancient  arts  of  Hindostan  exact  prototypes  of  the  sugar-roll- 
ers, horizontal  and  upright,  of  relatively  modern  invention  in  the  New  World. 

The  sugar-mill  of  Chinapatam,  fig.  1393,  consists  of  a  mortar,  lever,  pestle,  and  regu- 
lator.   The  mortar  is  a  tree  about  10  feet  in  length,  and  14  inches  in  diameter :  a  is  a 

plan  of  its  upper  end  ;  6 
is  an  outside  view ;  and 
c  is  a  vertical  section. 
It  is  sunk  perpendicu- 
larly into  the  earth,  leav- 
ing one  end  2  feet  above 
the  surface.  The  hol- 
low is  conical,  tnncated 
downwards,  and  then 
becomes  cylindrical, 
with  a  hemispherical 
projection  in  its  bottom, 
to  allow  the  juice  to  run 
freely  to  the  small  open- 
ing that  conveys  it  to  a 
spout,  from  which  it 
falls  into  an  earthen  pot. 
Round  the  upper  mouth 
of  the  cone  is  a  circular 
cavity,  which  collects  any  of  the  juice  that  may  run  over  from  the  upper  ends  of  the  pie- 
ces of  cane;  and  thence  a  canal  conveys  this  juice,  down  the  outside  of  the  mortar,  to 
the  spout.  The  beam  d,  is  about  16  feet  in  length,  and  6  inches  in  thickness,  being  cut 
out  from  a  large  tree  that  is  divided  by  a  fork  into  two  arms.  In  the  fork  an  excavation 
is  made  for  the  mortar  6,  round  which  the  beam  turns  horizontally.  The  surface  of  this 
excavation  is  secured  by  a  semi-circle  of  strong  wood.  The  end  towards  the  fork  is  quite 
open,  for  changing  the  beam  without  trouble.  On  the  undivided  end  of  the  beam  sits 
the  bullock-driver  c,  whose  cattle  are  yoked  by  a  rope  which  comes  from  the  end  of  the 
beam ;  and  they  are  prevented  from  dragging  out  of  the  circle  by  another  rope,  which 
passes  from  the  yoke  to  the  forked  end  of  the  beam.  On  the  arms  /,  a  basket  is  placed, 
to  hold  the  cuttings  of  cane;  and  between  this  and  the  mortar  sits  the  man  who  feeds  the 
mill.  Just  as  the  pestle  comes  round,  he  places  the  pieces  of  cane  sloping  down  into  the 
cavity  of  the  mortar ;  and  after  the  pestle  has  passed,  he  removes  those  that  have  beea 
squeezed. 

or  THE  MANUFACTURE  OF  SUGAR  IN  THE  WEST  INDIES. 

Cane-juice  varies  exceedingly  in  Hchness,  with  the  nature  of  the  soil,  the  culture  the 
season,  and  variety  of  the  plant.  It  is  an  opaque  fluid,  of  a  dull  gray,  olive,  or  olive- 
green  color ;  in  taste,  balmy  and  saccharine ;  exhaling  the  balsamic  odor  of  the  cane ; 
slightly  viscid;  and  of  a  specific  gravity  varying  from  1-033  to  M06,  according  to  cir- 
cumstances. When  fresh,  it  consists  of  two  parts;  the  one  liquid,  the  other  solid;  the 
latter  of  which  being  merely  suspended  in  the  former,  and,  therefore,  separable  in  a  great 
measure  by  filtration  or  repose.  The  solid  matter  consists  of  fragments  of  the  cellular 
parenchyma  of  the  cane,  its  fibres,  and  bark,  mechanically  protruded  through  the  mill; 
mixed  with  a  very  abundant  greenish  substance,  like  that  called  chlaroj^yle  by  che- 
mists. 

When  left  to  itself  in  the  colonial  climates,  the  juice  runs  rapidly  into  the  acetous 
fermentation;  twenty  minutes  being,  in  many  cases,  sufllcient  to  bring  on  this  destruc- 
bve  change.    Hence  arises  the  necessity  of  subjecting  it  immediately  to  clarifying  pro- 


766 


SUGAR. 


SUGAR. 


767 


eesses,  speedy  in  their  action.  When  deprived  of  its  green  fecula  and  glutinous  extrac- 
tive, It  IS  still  subject  to  fermentation  J  but  this  is  now  of  the  vinous  kind.  The  juice 
flows  from  the  mill  through  a  wooden  gutter  lined  with  lead,  and  being  conducted  into 
the  sugar-house,  is  received  m  a  set  of  large  pans  or  caldrons,  called  clarifiers.  On  es- 
tales  which  make  on  an  average,  during  crop  time,  from  15  to  20  hogsheads  of  sugar  a 
week,  three  clanfiers,  of  from  300  to  400  gallons'  capacity  each,  are  sufficient.  With  pans 
of  his  dimension,  the  liquor  may  be  drawn  off  at  once  by  a  stop-cock  or  syphon,  without 
disturbing  the  feculencies  after  they  subside.  Each  clarifier  is  hung  over  a  separate  fire, 
the  tiue  being  furnished  with  a  damper  for  checking  th«  combustion,  or  cxiinguishine  it 
altogether.  The  clarifiers  are  sometimes  placed  at  one  end,  and  sometimes  in  the  middle 
ot  the  house,  particularly  if  it  possesses  a  double  set  of  evaporating  pans. 

Whenever  the  stream  from  the  mill  cistern  has  filled  the  clarifier  with  fresh  juice  the 
fire  is  lighted,  and  the  temper,  or  dose  of  slaked  lime,  diffused  uniformly  through  a  little 
juice,  IS  added.  If  an  albuminous  emulsion  be  used  to  promote  the  clarifyin«',  very  little 
lime  will  be  required;  for  recent  cane-lujuor  contains  no  appreciable  portion  of  acid  to  be 
saturated.  In  fact,  the  lime  and  alkalis  in  general,  when  used  in  small  quantity,  seem 
U»  coagulate  the  glutinous  extractive  matter  of  ihe  juice,  and  thus  tend  to  bric'hten  it  up 
But  il  an  excess  of  temper  be  used,  the  gluten  is  taken  up  again  by  the  strong  affinity 
which  is  known  to  exist  between  sugar  and  lime.  Excess  of  lime  may  always  be  cor- 
rected by  a  little  alum-water.  Where  canes  grow  on  a  calcareous  marly  soil,  in  a  favor- 
able season,  the  saccharine  matter  gets  so  thoroughly  elaborated,  and  the  glutinous  mu- 
cilage so  completely  condensed,  that  a  clear  juice  and  a  fine  sugar  may  be  obtained 
Without  the  use  of  lime.  «  *cu 

1  A^  r^^  l''^"""  ^^?.\^  ^^^  ^^  ^^^  clarifier,  a  scum  is  thrown  up,  consisting  of  the  coagu- 
lated feculencies  of  the  cane-juice.  The  fire  is  now  gradually  urged  till  the  temperature 
approaches  the  boiling  point ;  to  which,  however,  it  must  not  be  suffered  to  rise.  It  is 
tnown  to  be  sufficiently  heated,  when  the  scum  rises  in  blisters,  which  break  into  white 
a-oth;  an  appearance  observable  in  about  forty  minutes  after  kindlin*'  the  fire  The 
damper  being  shut  down,  the  fire  dies  out ;  and  after  an  hour's  repose,  the  clarified  liquor 
is  ready  to  be  drawn  off  into  the  last  and  largest  in  the  series  of  evaporating  pans.  In 
the  British  colonies,  these  are  merely  numbered  1,  2,  3,  4,  5,  beginning  at  the  smallest, 
which  hangs  right  over  the  fire,  and  is  called  the  teache ;  because  in  it  the  trial  of  the 
Sirup  by  touch,  is  made.  The  flame  and  smoke  proceed  in  a  straight  line  along  a  flue  to 
the  chimney-stalk  at  the  other  end  of  the  furnace.  The  area  of  this  flue  proceeds,  with 
a  slight  ascent  from  the  fire  to  the  aperture  at  the  bottom  of  the  chimney;  so  that  be- 
iween  the  surface  of  the  grate  and  the  bottom  of  the  teache,  there  is  a  distance  of  28 
inches ;  while  between  the  bottom  of  the  flue  and  that  of  the  grand,  No.  5,  at  the  other  end 
of  the  range,  there  are  barely  18  inches. 

In  some  sugar-houses  there  is  planted,  in  the  angular  space  between  each  boiler,  a 
basin,  one  foot  wide  and  a  few  inches  deep,  for  the  purpose  of  receiving  the  scum  which 
thence  flows  off  into  the  grand  copper,  along  a  gutter  scooped  out  on  the  margin  of  the 
brick-work.  The  skimmings  of  the  grand  are  thrown  into  a  separate  pan,  placed  at  its 
side.  A  large  cylindrical  cooler,  about  six  feet  wide  and  two  feet  deep,  has  been  nlaced  in 
certain  sugar-works  near  the  teache,  for  receiving  successive  charges  of  its  insnissated 
sirup  Each  finished  charge  is  called  a  skipping,^  because  it  is  skfpp^  or  laded  out 
The  term  striking  is  also  applied  to  the  act  of  emptying  the  teache.  When  upon  one  skiiv 
ping  of  sirup  in  a  state  of  incipient  granulation  in  the  cooler,  a  second  skipping  is  poorl 
ed,  this  second  congeries  of  saccharine  particles  agglomerates  round  the  first  as  nuclei  o{ 
crystallization,  and  produces  a  larger  grain  ;  a  result  improved  by  each  successive  skip- 
pmg.  This  principle  has  been  long  known  to  the  chemist,  but  does  not  seem  to  ha^ 
been  always  properly  considered  or  appreciated  by  the  sugar-planter 
n  Jn^'T/^^  above  described  cooler  the  sirup  is  transferred  into  woiden  chests  or  boxes, 
open  at  top,  and  of  a  rectangular  shape ;  also  called  coolers,  but  which  are  more  proneS 
crystalhzersorgranulators.     These  are  commonly  six  in  number;  each  Wng  aCt  o„e 

Sr  «.  t?ff  "^'"Z'''  ^"  r^'  ^"'^  f  ^'  "'  ''"  ^'''  ''''^'-  When  filled  such  a  mals  is  coll^u 
ed,  as  to  favor  slow  cooling,  and  consequent  large-grained  crystall  zation.  If  these  boxM 
be  too  shallow,  the  grain  is  exceedingly  injured,  as  may  be  easily  shown  by  pouring  m^ 

^ft  san^  '''"^  "''  *  '""'"  '"^^  '  ^^'"'  ""  '^""^^"^'  '^^'  ^^?*'^"^  appear  mce  a  m^d^ 

in  yJ'^"'t"*' •  ^^-^^if  ^^l  "^^.'L^  ^"^"^  J"^?^  «^  the  due  concentration  of  the  simp 
in  the  teache   IS  difficult  to  describe,  and  depends  almost  entirely  on  the  sacacitv  and 

S'rthfhl'^W  nfVh'^^'^S-  "^n,^'  l'^"^  J"^-^^  "^y  ^^«  appeaLce  of  tKdpient 
grain  on  the  back  of  the  cooling  ladle ;  but  most  decide  by  «/!« /ottcA,"  that  is  the  fee' 
and  appearance  of  a  drop  of  the  sirup  pressed  and  then  drawn  into  a  thread  bet we« 
the  thumb  and  fore-finger.     The  thread  eventually  break*,  at  a  certain  Hmit  of  ext^n 
ion,  shrinking  from  the  thumb  to  the  suspended  LserXlnX^^^^^^ 


tional  to  the  inspissation  of  the  sirup.  But  the  appearance  of  granulation  in  the  thread 
must  also  be  considered  ;  for  a  viscid  and  damaged  sirup  may  give  a  long  enough  thread, 
and  yet  yield  almost  no  crystalline  grains  when  cooled.  Tenacity  and  granular  aspect 
must,  therefore,  be  both  taken  into  the  account,  and  will  continue  to  constitute  the  prac- 
tical guides  to  the  negro  boiler,  till  a  less  barbarous  mode  of  concentrating  cane-juice 
be  substituted  for  the  present  naked  teache,  or  sugar  frying-pan. 

That  weak  sugars  are  such  as  contain  an  inferior  proportion  of  carbon  in  their  com- 
position, was  first  deduced  by  me  from  my  experiments  on  the  ultimate  analysis  of  vege- 
table and  animal  bodies  ;  an  account  of  which  was  published  in  the  Philosophical  Trans- 
actions of  the  Royal  Society  for  1822.  Since  then.  Dr.  Prout  has  arrived  at  results 
confirmatory  of  my  views.  See  Philosophical  Transactions  for  1827.  Thus,  he  found 
pure  suifar-candy,  and  the  best  refined  sugar,  to  contain  42-85  parts  of  carbon  per  cent ; 
East  India  susar-candy,  41*9  parts;  East  India  raw  sugar  in  a  thoroughly  dry  state,  but 
of  a  low  quality,  40-88  ;  manna  sugar,  well  refined,  28-7 ;  sugar  from  Karbonne  honey, 
36*36 ;  sugar  from  starch,  36*2.  Hence,  by  caramelizing  the  sirup  in  the  teache,  not 
only  is  the  crystallizable  sugar  blackened,  but  its  faculty  of  crystallizing  impaired,  and 
the  granular  portion  rendered  weaker. 

A  viscous  sirup  containing  much  gluten  and  sugar,  altered  by  lime,  requires  a  higher 
temperature  to  enable  it  to  granulate  than  a  pure  saccharine  simp ;  and  therefore  the 
thermometer,  though  a  useful  adjuvant,  can  by  no  means  be  regarded  as  a  sure  guide,  in 
determining  the  proper  instant  for  striking  the  teache. 

The  colonial  curing-house  is  a  capacious  building,  of  which  the  earthen  floor  is  exca- 
vated to  form  the  molasses  reservoir.  This  is  lined  with  sheet  lead,  boards,  tarras,  or 
other  retentive  cement ;  its  bottom  slopes  a  little,  and  it  is  partially  covered  by  an  open 
massive  frame  of  joist-work,  on  which  the  potting  casks  are  set  upright.  These  arc 
merely  empty  sugar  hogsheads,  without  headings,  having  8  or  10  holes  bored  in  their 
bottoms,  through  each  of  which  the  stalk  of  a  plantain  leaf  is  stuck,  so  as  to  protrude 
downwards  6  or  8  inches  below  the  level  of  the  joists,  and  to  rise  above  the  top  of  the 
cask.  The  act  of  transferring  the  crude  concrete  sugar  from  the  crystallizers  into  these 
hogsheads  is  called  potting.  The  bottom  holes,  and  the  spongy  stalks  stuck  in  them, 
allow  the  molasses  to  drain  slowly  downwards  into  the  sunk  cistern.  In  the  common 
mode  of  procedure,  sugar  of  average  quality  is  kept  from  3  to  4  weeks  in  the  curing- 
house;  that  which  is, soft-grained  and  glutinous  must  remain  5  or  6  weeks.  The  curing- 
house  should  be  close  and  warm,  to  favor  the  liquefaction  and  drainage  of  the  viscid 
caramel. 

Out  of  120  millions  of  pounds  of  raw  sugar,  which  used  to  be  annually  shipped  by  the 
St,  Domingo  planters,  only  96  millions  were  landed  in  France,  according  to  the  authority 
of  Dutrone,  constituting  a  loss  by  drainage  in  the  ships  of  20  per  cent.  The  average 
transport  waste  at  present  in  the  sugars  of  the  British  colonies  cannot  be  estimated  at 
less  than  12  per  cent.,  or  altogether  upwards  of  27,000  tons !  What  a  tremendous  sacri- 
fice of  property ! 

Within  these  few  years  a  very  considerable  quantity  of  sugar  has  been  imported  into 
Great  Britain  in  the  state  of  concentrated  cane-juice,  containing  nearly  half  its  weight 
of  granular  sugar,  along  with  more  or  less  molasses,  according  to  the  care  taken  in  the 
boiling  operations.  I  was  at  first  apprehensive  that  the  sirup  might  undergo  some 
change  on  the  voyage ;  but  among  more  than  a  hundred  samples  which  I  have  analyzed 
for  the  custom-house,  I  have  not  perceived  any  traces  of  fermentation.  Since  sugar  softens 
in  its  grain  at  each  successive  solution,  whatever  portion  of  the  crop  may  be  destined 
for  the  refiner,  should  upon  no  account  be  granulated  in  the  colonies ;  but  should  be 
transported  in  the  state  of  a  rich  cane-sirup  to  Europe,  transferred  at  once  into  the 
blowing-up  cistern,  subjected  there  to  the  reaction  of  bone  black,  and  passed  through 
bag-filters,  or  through  layers  of  the  coarsely  ground  black,  previously  to  its  final  concen- 
tration in  the  vacuum  pan.  Were  this  means  generally  adopted,  I  am  convinced  that  30 
per  cent,  would  be  added  to  the  amount  of  home-made  sugar  loaves  corresponding  to  a 
given  quantity  of  average  cane-juice ;  while  30  per  cent,  would  be  taken  from  the 
amount  of  molasses.  The  saccharine  matter  now  lost  by  drainage  from  the  hogsheads  in 
the  ships,  amounting  to  from  10  to  15  per  cent.,  would  also  be  saved.  The  produce  of 
the  cane  would,  on  this  plan,  require  less  labor  in  the  colonies,  and  might  be  exported  5 
or  6  weeks  earlier  than  at  present,  because  the  period  of  drainage  in  the  curing-house 
-would  be  spared. 

It  does  not  appear  that  our  sugar  colonists  have  availed  themselves  of  the  proper 
chemical  method  of  counteracting  that  incipient  fermentation  of  the  cane-juice,  which 
sometimes  supervenes,  and  proves  so  injurious  to  their  products.  It  is  known  that  grape- 
must,  feebly  impregnated  with  sulphurous  acid,  by  running  it  slowly  into  a  cask  in 
which  a  few  sulphur  matches  have  been  burned,  will  keep  without  alteration  for  a  year; 
and  if  must,  so  muted,  is  boiled  into  a  sirup  within  a  week  or  ten  days,  it  retains  no 
sulphureous  odor.    A  very  slight  muting  would  suffice  for  the  most  fermenta?>le  cane- 


I 


IH 


768 


SUGAR. 


II 


;|uice;  and  it  could  be  easily  given,  by  burning  a  sulphur  match  within  the  cistern 
immediately  before  charging  it  from  the  mill.  The  cane  juice  should,  in  this  case,  be 
heated  m  the  clarifier,  so  as  to  expel  the  sulphurous  acid,  before  adding  the  temper  lime* 
for  otherwise  a  little  calcareous  sulphite  might  be  introduced  into  the  suo-ar  Thus  the 
acescence  so  prejudicial  to  the  saccharine  granulation  would  be  certainly  prevented. 

Sirup  intended  for  formmg  c.ayea  sugar  must  be  somewhat  more  concentrated  in  the 
.cache,  and  run  off  into  a  copper  cooler,  capable  of  receiving  three  or  four  successive 
skippings.  Here  it  is  stirred  to  ensure  uniformity  of  product,  and  is  then  transferred  bt 
ladles  into  conical  moulds,  or  formes,  made  of  coarse  pottery,  having  a  small  orifice  at 
the  apex,  which  is  stopped  with  a  plug  of  wood  wrapped  in  a  leaf  of  maize.  Thesfl 
pots  are  arranged  with  the  base  upwards.  As  their  capacity,  when  largest  is  sreatlf 
less  than  that  of  the  smallest  potting-casks,  and  as  the  process  lasts  severalweeks  the 
claying-house  requires  to  have  very  considerable  dimensions.  Whenever  the  sirup  is 
properly  granulated,  which  happens  usually  in  about  18  or  20  hours,  the  plugs  are 
removed  from  the  apices  of  the  cones,  and  each  is  set  on  an  earthen  pot  to  receive  the 
drainings.  At  the  end  of  24  hours,  the  cones  are  transferred  over  empty  pots,  and  the 
molasses  contained  in  the  former  ones  is  either  sent  to  the  fermenting-house  or  sold. 
The  claying  now  begins,  which  consists  in  applying  to  the  smoothed  surface  of  the 
sugar  at  the  base  of  the  cone,  a  plaster  of  argillaceous  earth,  or  tolerably  tenacious  loam 
in  a  pasty  state.  The  water  diffused  among  the  clay  escapes  from  it  by  slow  infiltra- 
tion, and  descending  with  like  slowness  through  the  body  of  the  sugar,  carries  along 
with  it  the  residuary  viscid  sirup  which  is  more  readily  soluble  than  the  granulated 
particles.  Whenever  the  first  magma  of  clay  has  become  dry,  it  is  replaced  by  a  second  • 
and  this  occasionally  in  its  turn  by  a  third,  whereby  the  sugar  cone  gets  tolerably  white 
and  clean.  It  is  then  dried  in  a  stove,  cut  transversely  into  frusta,  crushed  into  a  coarse 
powder,  on  wooden  trays,  and  shipped  off  for  Europe.  Clayed  sugars  are  sorted  into 
different  shades  of  color,  according  to  the  part  of  the  cone  from  which  they  were  cut  • 
under  the  denomination  in  French  commerce  or  premier,  second,  iroisieme,  petit,  commun 
and  tete ;  the  last  or  the  tip  being  an  indifferent  article.  The  clayed  sugar  of  Cuba  is 
called  Havana  sugar,  from  the  name  of  the  shipping  port. 

Clajed  sugar  can  be  made  only  from  the  ripest  cane-juice,  for  that  which  contains 
much  gluten  would  be  apt  to  get  too  much  burned  by  the  ordinary  process  of  boiling  to 
bear  the  claying  operation.  The  sirups  that  run  off  from  the  second,  third,  and  fourth 
applications  of  the  clay-paste,  are  concentrated  afresh  in  a  small  building  apart,  called 
the  refinery,  and  yield  tolerable  sugars.  Their  draininsjs  go  to  the  molasses  cistern.  The 
cones  remain  for  20  days  in  the  claying-house,  before  the  sugar  is  taken  out  of  them. 
^  Claying  is  seldom  had  recourse  to  in  the  British  plantations,  on  account  of  the 
increase  of  labor,  and  diminution  of  weight  in  the  produce,  for  which  the  improvement 
in  quahty  yields  no  adequate  compensation.  Such,  however,  was  the  esteem  in  which 
Ihe  French  consumers  held  clayed  sugar,  that  it  was  prepared  in  400  plantations  of  St. 
Domingo  alone.  *^ 

SUGAR  REFINING. 

Raw,  or  muscovado  sugar,  as  imported  from  the  colonies,  is  contaminated  more  or 
less  with  gluten,  lune,  but  particularly  caramel,  which  give  its  grains  a  yellow  brown 
tint,  an  empyreumatic  odor,  and  a  soft  clammy  feel  in  the  hand.  If  such  sugar  be  dis- 
solved in  water,  and  the  sirup  be  evaporated  by  a  gentle  heat,  it  wiU  afford  a  sugar  of 
still  inferior  quality  and  appearance.  This  rapid  deterioration  is  in  some  measure 
owing  to  the  injurious  operation  of  a  prolonged  ^^eat  upon  the  crystalline  structure,  but 
^lefly  to  the  chemical  reaction  of  the  glutinous  ferment  and  lime  upon  the  sugar. 
The  first  care  of  the  refiner  should  therefore  be  the  immediate  abstraction  of  these 
noxious  alteratives,  which  he  effects  by  the  process  called  meltings;  that  is,  mixing  up 
the  sugar  m  a  pan  with  hot  water  or  steam  into  a  pap,  and  transferring  this  pap  into 
large  sugar-moulds.  Whenever  these  become  cool,  their  points  are  unplugged,  and  they 
are  set  tc  Irain  for  a  few  days  in  a  warm  apartment.  Sugar  thus  cleansed  is  well  pre- 
pared tor  the  next  refining  process ;  which  consists  in  putting  it  into  a  large  square 
copper  cistern  along  with  some  lime-water,  (a  little  bullock's  blood,)  and  from  5  to  20 
per  cent,  of  bone  black,  and  blowing  it  up  with  steam ;  or,  in  other  words,  injecting 
steam  through  the  mixture  from  numerous  orifices  in  copper  pipes  laid  along  the 
bottom  and  sides  of  the  vessel.  Under  the  influence  of  the  heat  and  agitation  thus 
occasioned,  the  saccharine  matter  is  perfectly  dissolved  and  incorporated  with  the  albumen 
of  the  blood  and  the  bone  black.  Instead  of  the  blood,  many  refiners  employ  a  mixture  of 
gelatinous  alumina  and  gypsum,  caUed^ntng*,  prepared  by  adding  a  solution  of  alum  to 
a  body  of  lime-water,  coUecting,  washing,  and  draimng  the  precipitate  upon  a  filter. 


SUGAR. 


769 


1894  Other  refiners  nse  both  the  blood  and  finings  with  advantage 

iJone  DlacK  is  now  very  frequently  employed  by  the  sugar-renner, 
not  in  a  fine  meal,  but  in  a  granular  state,  like  corned  gunpowder, 
for  the  purpose  of  decoloring  his  sirups ;  in  which  case,  he  places 
it  in  a  box,  in  a  stratum  8  or  10  inches  thick,  and  makes  the 
sirup  percolate  downwards  through  it,  into  a  cistern  placed  be. 
neath.  By  this  means  it  is  deprived  of  color,  and  forms  th« 
clairce  of  the  French  refiner.  When  the  blowing  up  cistern  ii 
charged  with  sugar,  finely  ground  bone  black,  and  blood,  the  mix. 
ture  must  be  passed  through  a  proper  system  of  filters.  Thai 
now  most  in  use  is  the  creased  bag  filter,  represented  in  fies.  1394 
1395,  1396.  "^  * 

The  apparatus  consists  of  an  upright  square  wooden  case  o,  a, 
about  6  or  8  feet  high,  furnished  with  a  door  of  admission  to  arrange 
the  interior  objects ;  beneath  is  a  cistern  with  an  educting-pipe  for 
receiving  and  carrjing  off  the  filtered  liquor;  and  above  the  case 
is  another  cistern  e,  which,  like  the  rest,  is  lined  with  tinned  sheet 
copper.  Into  the  upper  cistern,  the  sirup  mixed  with  animal 
charcoal  is  introduced,  and  passes  thence  into  the  mouths  «,  e,  of 
the  several  filters  d,  d.  These  consist  each  of  a  bag  of  thick 
tweeled  cotton  cloth,  about  12  or  15  inches  in  diameter,  and  6  or 
8  feet  long,  which  is  inserted  into  a  narrow  bottomless  bag  of 
canvass,  about  5  inches  in  diameter,  for  the  purpose  of  folding  the 
filter-bag  up  into  a  small  space,  and  thus  enabling  a  great  extent 
of  filtering  surfaces  to  be  compressed  into  one  box.  The  orifice  of 
each  compound  bag  is  tied  round  a  conical  brass  mouth-piece  or 
nozzle  e,  which  screws  tight  into  a  corresponding  opening  in  the 
copper  bottom  of  the  upper  cistern.  From  40  to  60  bags  are  mounted 
in  each  filter  case.  The  liquor  which  first  passes  is  generally  tinged 
a  httle  with  the  bone  black,  and  must  be  pumped  back  into  the  upper  cistern,  for  refil- 
tration.  In  cold  weather  the  interior  of  the  case  may  be  kept  warm  by  a  proper  dis- 
tribution of  steam-pipes.  Fig.  1395  shows  one  mode  of  forming  the  funnel-shaped 
nozzles  of  the  bags,  in  which  they  are  fixed  by  a  bayonet  catch.  Fig.  1396  shows  the 
same  made  fast  by  means  of  a  screwed  cap,  which  is  more  secure. 

The  next  process  in  sugar-refining  is  the  evaporation  of  the  clarified  sirup  to  the 

granulating  or  crystallizing  pitch.     The  more  rapidly  this  is  effected,  and  with  the  less 

scorching  injury  from  fire,  the  better  and  greater  is  the  product  in  sugar-loaves.    No 

apparatus  answers  the  refiner's  double  purpose  of  safety  and  expedition  so  well  as  the 

•cuum-pan  of  Howard. 

F^.  189Y  shows  the  structure  of  a  single  vacuum-pan.  The  horizontal  diameter  of 
the  copper  spheroid  a  is  not  less  than  5  feet;  the  depth  of  the  under  hemisphere  is  at 
Ijeast  18  mch€«  from  the  level  of  the  plane;  and  the  height  of  the  dome-cover  is  2  feet 
Ihe  two  hemispheres  (of  which  the  inferior  one  is  double,  or  has  a  steam-jacket)  ars 

f.'in^'f  ?f  ^^  ^?'^!  *"*^  f""^^^^  "^''^^  P^«^'"g  b^t^«^«  ^^^  fla"g««  to  preserve  ths 
joints  tight  against  atmospheric  pressure.  The  jacket  of  the  lower  hemisphere  forms 
the  case  of  the  steam,  which  communicates  heat  to  the  syrup  enclosed  in  the  innef 
hemisphere.  In  general,  the  pans  contain,  when  filled  to  the  flange,  100  gallons  of 
syrup,  and  yield  about  11  cwt  of  granulated  sugar  at  every  charge  ^ 

r.\t  "P'"*'^'?^,  the  vacuum  spheriod ;  b,  the  neck  with  the  lid.     From  the  side  of  b,  a 

ve?ticTr>TJ  K  connirr  TT^^  ^^  ^"  ^?"'  .P^P^  ^'  ^'  ^»»i«^  terminates  in  V, 
vertical  pipe  k,  connected  with  the  vacuum  main-pipe  k,  proceeding  horizontally  from 

^is'l^o^d  ?  ^""'/mT-  ^^  '^'  ^^^''^  ^'  '^'  toVof  ^^a  valve,  movablT  by  a  sc^ 
Lhi?i  .  i  .1''^^^^"'''°^.^'  '"^'>^  ^^  ^^^  connection  with  the  air-pump  at  pleasSI 
fhfZi    •  T.  '^^  ™'*'"'.^  S?,^^'°'  ^'•«'"  ^^''^^  ^^^  successive  charges  are  a^dmitted  into 

D^ne^und.r?h'  "'f'"''  \^l'^  ^^'^  ^^'  '^'^'  '^'''^'  ^^^  opening  the  stopcock  "on  aJ 
pipe  under  the  ceiling,  which  communicates  with  the  filter-cistern  placed  above     ois 

ThiJnw'r  P^"^'.^k''  *'  '^'  ^/''"™  ^^  '^'  P^°'  ^^^^  discharging  the^granulatfng  syru^ 
It  1^1  lL??rnrlvi^  T •  \"^ " P"^/'^"^  '"^r  \^**^»»^^ "^^^ '''^^ connection litlth^ 
theS  ^I/ZouT^  intercepted,  i,  is  the  barometer,  or  manometer,  for  showing 
reeeiv?n^  /nv  llJl?  corresponding  to  the  temnerature.     n,  k,  is  a  cistern-pipe  for 

Ze  ill  off  h^l^nJT  .""-^  K  T^  ^r'^^^^^^y  boil  over  the  neck  b.  Its  ^ntenU 
Zj^\ri.^  •  '^°P9°^^^^  »t8  bottom  from  time  to  time,    m  shows  the  place  of  the 

£r!  -^See  t/ra  °^''''''"'  '"^  ^''"  ^^^^  ^"^  *  «""P^^  ^^  ^^^^P  ^^t^^^"*  ^^"^^^S 

»A^ff^A^T^V''^Z  ?'*°**'"l  ^^^"^  2?  ^*"«°«-  This  quantity  of  syrup  being  first 
S?,r.i  !J'  •  •  T-^^^  ^  \''r^^^"  P'^^^  *^^  concentratioS.  a  second  measure  is  in™ 
duced,  the  inspissation  of  which  is  supposed  by  some  refinera  to  cause  an  agglomeration 


T70 


SUGAK. 


1397 


I 


I 


of  sacchanne  matter  round  the  first  crystalline  particles.  The  repetition  of  tnis  proeeM 
for  two  or  three  times  is  imagined  to  produce  the  large  brilliant  grain  of  vacuum-pan 
sugar.  This  hypothesis  is  more  specious  than  sound,  because  the  granulating  syrup 
discharged  from  the  pan  is  subjected  to  a  heat  of  180°  or  190°  in  the  subjacent  steam- 
cased  receiver,  whereby  the  granulations  are  again  reduced  to  a  very  small  size.  Into 
this  receiver,  two  or  three  skippings  or  discharges  of  the  pan  are  admitted  in  succesaion, 
and  the  whole  are  diligently  mixed  and  agitated  by  a  stirring  oar.  It  is  by  this  proceae 
that  the  granulating  tendency  is  promoted  and  determined.  From  this  receiver 
(absurdly  enough  called  a  cooler)  the  moulds  are  filled  in  the  usual  way,  by  means  of 
copper  basins  or  large  ladles. 

The  case  of  the  under  hemisphere  of  the  vacuum-pan  is  filled  with  steam,  generated 
under  a  pressure  of  4  or  6  pounds  on  the  square  inch ;  the  heat  of  which  causes  the  interior 
syrup  to  boil  rapidly  while  the  air-pump  is  kept  in  action.  A  small  escape-pipe  for 
-waste  steam  must  be  placed  at  the  opposite  side  of  the  case  or  jacket,  to  ensure  its  equal 
distribution ;  as  also  a  stopcock  below,  to  let  oflf  the  water  of  condensation.  The  paos 
«re  mounted  on  iron  feet,  or  short  pillars,  which  insulate  them  from  the  floor,  and  allow 
their  whole  surface  to  be  inspected,  and  any  flaw  to  be  repaired.  The  air-pump  usually 
stands  in  a  cold-water  cistern,  to  favor  the  condensation  of  the  aqueous  vapor,  which 
It  draws  out  of  the  pans;  and  it  is  kept  in  constant  action  by  the  steam-engine,  being 
attached  to  the  working-beam  of  its  piston. 

Mg.  1398  exhibits  the  general  arrangement  of  the  vacuum-pans,  and  their  subsidiary 
apparatus.  Here  are  shown,  on  the  ground  floor,  the  heaters  e,  e  (miscalled  coolers),  into 
which  the  concentrated  syrup  is  let  down.  These  heaters  are  made  of  copper,  in  one  piece, 
surrounded  with  a  cast-iron  jackets  bolted  at  the  flange  or  brim  to  it  Each  pan  contains, 
when  full,  about  350  gallons,  equivalent  to  nearly  86  cwt.  of  crystallized  sugar.  They 
are  furnished  with  steam-cocks  and  waste  steam-pipes.  Under  the  level  of  the  spheroiA 
d,d,  the  horizontal  main  pipe  is  seen,  for  supplying  the  cases  with  steam.  In  the  face 
of  each  pan,  above  the  line  b,  b,  the  handle  of  the  proof-stick  appears,  like  that  of  a  stop- 
cock.   The  distribution  of  the  measure  cisterns,  and  some  other  parts  of  the  pans^  w 


slightly  varied  in  this  representation  from  the  former.  From  the  bottom  of  the  liquor 
cisterns  c,  c,  pipes  descend  to  the  charging  measures  a,  a,  below.  The  cisterns  c,  c,  are 
made  of  copper,  and  contain  each  about  400  gallons.  Six  tons  of  refined  sugar  can  be 
turned  out  daily  in  a  three-pan  house. 

Fig.  1399  represents  in  section  another  form  of  the  vacuum-pan.      a  is  the  spheroidal 
eopper  vessel,  supported  by  four  iron  columns  6, 6.    It  may  be  discharged  by  meant  of 


Ike  pipe  c,  which  is  secured  with  a  conical  valve  d.  This  may  be  opened  or  shot,  bf 
acting  on  the  lever  e.  The  lower  of  the  two  hemispheres  of  which  the  pan  is  composed 
IS  double,  and  the  interstitial  space/,/,  is  filled  with  steam  by  the  pipe  g,  as  the  heetduT 
and  evaporating  agent,  h,  is  the  steam  valve ;  i,  the  pipe  for  the  efflux  of  the  condensed 
water,  /c,  a  tube  for  the  escape  of  the  air  at  the  commencement  of  the  operation.  L  is 
an  apparatus  inserted  air-tight  into  the  cover  of  the  vacuum-pan,  and  which  dips  down 
into  the  sirup;  serving  to  take  out  a  sample  of  it,  without  allowmg  air  to  enter,  and 
1  Jm^  1*"?^  lino  P/i!?^^fn;  ?\^  construction  of  this  instrument  is  exhibited  in  Jigs. 
ll:Ik  '^'      ^'  ^^A^-  ^^^?'  '^^'''^  "^'^  ^^  presently  explained,     tn,  is  the  thermometer, 

^ut  v.±?  ^^uT^ ■lltV^t.^"'^^! '.  ^^^^"^  ^^'  »^  ^»»«  barometer.  «,  is  the  charger  o^ 
gauge-vessel,  fi»ed  with  the  filtered  sirup,  which  it  discharges  by  the  pipe  «'.  o,  is  the 
cover  or  capital  of  the  vacuum-pan.  o',  is  a  safety-valve,  through  which  the  air  may  be 
admitted  ail er  the  completion  of  the  process,  p,  is  a  bent  pipe,  slanting  downwirds 
with  a  stopcock  9  at  its  end,  to  receive  the  superfluous  sirup.  The  vapor,  which  is 
disengaged  from  the  sirup  during  its  concentration,  is  extracted  from  the  top  of  the 
pan  into  the  pipe  r,  passes  from  this  into  the  vessel  *,  which  is  divided  by  a  plate  of 


T72 


SUGAR. 


SUGAR. 


773 


copper  into  two  compartments.     The  syrap  forced  over  aecidentallj  in  the  ebullition, 

goes  into  the  vessel  »,  and  passes  by  the  glass  tube  t,  into  the  pipe  p.     The  glass  tube 

serves  to  show  the  quantity  of  the  sirup  that  has  boiled  over,  so  that  it  may  be  drawn 

off  when  necessary.     For  this  purpose,  the  stopcock  «,  of  the  vessel  v,  must  be  closed, 

and  q  must  be  opened,  in  order  to  fill  r,  while  the  air  contained  in  it  escapes  into  the 

pan.    The  stopcock  q,  being  then  shut,  and  u,  with  the  little  air-cock  a:,  opened,  the  sirup 

will  flow  into  the  large  receiver  placed  beneath  it,  commonly  but  erroneously  called  a 

cooler;   because  it  is  a  double  copper  basin,  with  steam  in  the  interstitial  space.      The 

hot  steam  rushes  from  a,  into  the  cast-iron  vessel  y,  where  it  is  condensed.    «,  is  a  pipe 

for  introducing  the  water  of  condensation  through  the  copper  rose  a\  The  condensed  water 

flows  through  the  pipe  b',  and  the  valve  e',  to  the  air-pump,  which  receives  motion  from 

the  shaA  of  the  steam-engine. 

The  vacuum-pan  was  originally  heated  solely  by  the  admission  of  steam  between  the 

1400  double  bottom ;   but  of  late  years  the  heat 

has  been  also  applied  to  the  simp  through 
several  coils  of  pipe  placed  within  the  pan, 
filled  with  steam  at  a  temperature  many 
degrees  above  212°  F.,  sometimes  so  high 
as  250°.  By  this  double  application  of 
heat,  the  evaporating  power  of  a  pan  has 
been  vastly  increased.  The  latest  made 
pans  have  a  considerably  flat  bottom,  fig, 
1400  ;  a  spiral  pipe,  laid  close  upon  it ;  and 
between  the  under  hemisphere  and  the 
upper  one,  there  is  a  space  a,  a,  2^  feet 
high,  to  give  the  sirup  room  for  frothing 
up  without  boiling  over.  The  space  b,  of 
the  bottom  receives  steam  of  common 
pressure,  and  the  spiral  tubes,  of  high 
pressure.  A  pan  like  this  is  now  making  for 
a  house  in  London,  which  is  to  work  off  16 
tons  of  sugar-loaves  daily. 
The  proof-stick,  ^g.  1405,  consists  of  a  cylindrical  rod,  capable  of  being  screwed  air- 
tight into  the  pan  in  an  oblique  direction  downwards.  The  upper  or  exterior  end  is  open ; 
the  under,  which  dips  into  the  sirup,  is  closed,  and  has  on  one  side  a  slit  a  (figs.  1401, 1402) 
cr  notch,  about  |  inch  wide.   In  this  external  tube,  there  is  another  shorter  tube  6,  capable 


1402 


1401 


m 


of  moving  round  in  it,  through 
an  arc  of  180°.  An  opening 
upon  the  under  end  «,  corre- 
sponds with  the  slit  in  the  outer 
tube,  so  that  both  may  be  made 
to  coincide,  fig.  1401,  A.  A 
wooden  plug  d,  is  put  in  the 
interior  tube,  but  so  as  not  to 
shut  it  entirely.  Upon  the 
upper  end  there  is  a  projection 
or  pin,  which  catches  in  a  slit 
of  the  inner  tube,  by  which 
this  may  be  turned  round  at 
pleasure.  In  the  lower  end  of 
the  plug  there  is  a  hole  e,  which 
can  be  placed  in  communication  with  the  lateral  openings  in  both  tubes.  Hence  it  if 
possible,  when  the  plug  and  the  inner  tube  are  brought  into  the  proper  position,  a, 
fig,  1401,  to  fill  the  cavity  of  the  wooden  rod  with  the  sirup,  and  to  take  it  out  without 
allowing  any  air  to  enter.  In  order  to  facilitate  the  turning  of  the  inner  tube  within 
the  outer,  there  is  a  groove  in  the  under  part,  into  which  a  little  grease  may  be 
introduced. 

Whenever  a  proof  has  been  taken,  the  wooden  plug  must  be  placed  in  reference  to  the 
mner  tube,  as  shown  in  fig.  1401,  c,  and  then  be  turned  into  the  position  a  ;  when  the 
cavity  of  the  plug  will  again  be  filled  with  sirup,  c  must  be  now  turned  back  to  the  for- 
mer position,  whereby  all  intercourse  with  the  vacuum-pan  is  cut  off;  the  plug  being  drawn 
«fut  a  little,  and  placed  out  of  communication  with  the  inner  tube.  The  plug  is  then  turned 
into  the  position  b,  drawn  out,  and  the  proof  examined  by  the  fingers. 

Table  showing  the  boiling  point  of  sirup,  at  the  corresponding  atmospheric  pressure 

within  the  vacuum-pan : — 

Height  of  the  mercury  (iachei)  in  oae  leg  of  the  syphon,  abore  that  in  the  other— 

0-74   0»86    1-01    M7    1-36    1-57    1-80  205    2-36   2-72   3- 10   3-52    4-OU. 


*^ 


a 


1407 


Boiling  point,  Fahr.— 
116°  120^  126°  130°  135°  140°  145°  150°  165°  160°  165°  170°  HS®. 

The  large  double  steam-basin,  which  receives  several  successive  skippings  of  the 
concentrated  granulating  sirup,  serves  to  heat  it  from  the  temperature  of  160®  or  170°,  at 
which  it  leaves  the  vacuum-pan,  up  to  200°  or  thereby,  before  it  is  filled  out  into  the  moulds ; 
for  were  it  introduced  in  the  cooler  state,  it  would  not  concrete  into  sufliciently  compact 
loaves. 

The  following  apparatus  is  used  in  many  French  sugar-houses,  for  concentrating 
sirups,  called  the  sioing  pan,  or  chavdilre  H  bascule.      It  is  represented  in  fig,  1406,  in 
1406  elevation,  and  in^g.  1407,  in  ground  plan,      a,  is  the  pan; 

bj  its  spout ;  c,  the  axis  or  pivot  round  which  it  swings, 
so  as  to  empty  itself,  when  raised  behind  by  the  chain  d  ; 
e,  is  the  furnace  door ;  /,  the  passage  to  the  fireplace  and 
grate  g ;  A,  A,  A,  side  flues  for  conducting  the  smoke  into  the 
chimney. 

The  duly  clarified,  concentrated,  granulated,  and  re- 
heated sirup,  is  transferred,  by  means  of  copper  basins,  from 
the  coolers  into  conical  moulds,  made  either  of  brown  and 
somewhat  porous  earthenware,  or  of  sheet  iron,  strongly 
painted.  The  sizes  of  the  moulds  vary,  from  a  capacity 
of  10  pound  loaves,  to  that  of  56  pound  bastards — a  kind 
of  soft  brown  sugar  obtained  by  tbe  concentration  of  the 
inferior  sirups.  These  moulds  have  the  orifices  at  their 
tips  closed  with  bits  of  twisted  paper,  and  arc  set  up  in 
rows  close  to  each  other,  in  an  airy  apartment  adjoining 
the  coolers.  Here  they  are  left  several  hours,  commonly 
the  whole  night,  after  being  filled,  till  their  contents 
become  solid,  and  they  are  lifted  next  morning  into  an 
upper  floor,  kept  at  a  temperature  of  about  80°  by  means  of 
^♦•'am  pipes,  and  placed  each  over  a  pot  to  receive  the  sirup 
draining^ — the  paper  plug  being  first  removed,  and  a  steel 
wire,  called  a  piercer,  being  thrust  up  to  clear  away  any 
concretion  firom  the  tip.  Instead  of  setting  the  lower 
portion  of  the  inverted  cones  in  pots,  some  refiners  arrange  them  in  wooden  racks,  with 
their  apiees  suspended  over  longitudinal  gutters  of  lead  or  zinc,  laM  with  a  slight  slope 
upon  the  floor,  and  terminating  in  a  sunk  cistern.  The  sirup  which  flows  off  spon- 
taneously is  called  green  sirup.  It  is  kept  separate.  In  the  course  of  two  or  three 
days,  when  the  drainage  is  nearly  complete,  some  finely  clarified  sirup,  made  from  loaf 
sugar,  called  liqtior  by  the  refiners,  is  poured  to  the  depth  of  about  an  inch  upon  the 
base  of  each  cone,  the  surface  having  been  previously  rendered  level  and  solid  by  an 
iron  tool,  called  a  bottoming  trowel.  The  liquor,  in  percolating  downwards,  being 
already  a  saturated  sirup,  can  dissolve  none  of  the  crystalline  sugar,  but  only  the 
colored  molassy  matter ;  whereby,  at  each  successive  liquoring,  the  loaf  becomes  whiter, 
from  the  base  to  the  apex.  A  few  moulds,  taken  promiscuously,  are  emptied  from  time 
to  time,  to  inspect  the  progress  of  the  blanching  operation ;  and  when  the  loaves  appear 
to  have  acquired  as  much  cotor,  according  to  the  language  of  refiners,  as  is  wanted  for 
the  particular  market,  they  are  removed  from  the  moulds,  turned  on  a  lathe  at  the  tips,  if 
necessary,  set  for  a  short  time  upon  their  bases,  to  diffuse  their  moisture  equally  through 
them,  and  then  transferred  into  a  stove  heated  to  130°  or  140°  by  steam  pipes,  where  they 
•re  allowed  to  remain  for  two  or  three  days,  till  they  be  baked  thoroughly  dry.  They  are 
then  taken  out  of  the  stove,  and  put  up  in  blue  paper  for  sale. 

In  the  above  description  of  sugar-refining,  I  have  said  nothing  of  the  process  of  clay- 
ing the  loaves,  because  it  is  now  nearly  obsolete,  and  abandoned  in  all  well-appointed 
sugar-bouses.  Those  of  my  readers  who  desire  to  become  acquainted  with  sugar- 
refining  upon  the  old  plan,  may  consult  my  Report  made  upon  the  subject  to  the 
Honorable  Housb  of  Commons  in  July,  1833;  where  they  will  find  every  step  detailed, 
and  the  numercial  results  stated  with  minute  accuracy.  The  experiments  subservient 
to  that  oflUcial  report  were  instituted  purposely  to  determine  the  average  yield  or  pro- 
duct, in  double  and  single  refined  loaves,  lumps,  bastards,  and  treacle,  which  different 
kinds  of  sugar  would  afford  per  cwt,  when  refined  by  decoloring  with  not  more  than  5 
per  cent  of  bone  black,  boiling  in  an  open  pan,  and  clearing  the  loaves  with  clay-pap. 
Centrifugal  action  has  been  of  late  years  had  recourse  to  for  separating  the  uncryst^- 
lizable  from  the  granular  portion  of  sugar ;  and  the  following  mode  of  applying  it  seems  to 
be  one  of  the  most  efficacious.  It  was  patented  in  October  1849,  by  Mr.  C.  W.  Finzel, 
of  Bristol.  Fia.  1408  is  an  elevation,  partly  in  section ;  fiff.  1409  is  a  vertical  section, 
and^.  1410  a  front  view  (both  on  a  larger  scale  than/^.  1408)  of  the  perforated  box,  by 


I  mm 


774 


SUGAR. 


SUGAR. 


775 


mm 


Hi 


1411 


1413 


which  steam  is  caused  to  act  against  the  periphery  of  the  cylinder  or  drum  of  the  machine. 
In  the  outer  ease  a,  a  narrow  recess  b,  of  nearly  the  same  height  as  the  revolving 
cylinder  c  is  formed ;  and  in  this  recess  is  placed  the  steam  box  d,  connected  by  a  pipe 
e,  with  a  steam  boiler.  The  side  of  the  box  d,  which  is  nearest  to  the  cylinder  «,  is  per- 
forated with  small  holes,  through  which  the  steam  rushes  in  numerous  jets  against  the 
periphery  of  the  cylinder  c  ;  and  such  steam  is  prevented  from  escaping  from  the  machine 
by  the  application  of  lids/,  to  the  top  of  the  case  a. 

The  mode  of  operating  with  the  machine  is  as  follows: — 

The  sugar  having  been  mixed  with  molasses  or  syrup,  to  bring  it  to  the  proper  con- 
sistency, is  put  in  the  cylinder  c,  which  is  then  caused  to  rotate ;  and  after  the  cylinder 
has  made  a  few  turns,  the  steam  is  let  on  (by  turning  a  cock  on  the  pipe  c),  and  per- 
mitted to  issue  freely  through  the  holes  in  the  box  d,  against  the  periphery  of  the  cylinder 
for  about  a  minute,  which  has  the  effect  of  clearing  the  meshea  The  state  of  the  sugar 
may  be  ascertained,  from  time  to  time,  without  stopping  the  machine,  by  raising  the  lids 
/;  and  if  the  extraction  of  the  moisture  therefrom  appears  to  be  impeded,  steam  is  to  be 
again  let  on  for  a  short  time,  in  order  to  clear  the  meshes.  The  cylinder  c  is  to  be  kept 
rotating,  and  the  steaming  repeated  occasionally  (if  required)  until  the  whole  or  nearly 
the  whole  of  the  syrup  or  fluid  is  extracted  from  the  sugar;  and  this,  when  operating 
upon  ordinary  sugar,  will  generally  be  effected  in  a  few  minutea  Sugars  taken  from 
the  evaporating  pan,  after  partial  cooling,  may  be  put  into  the  machine,  and  operated 
upon  directly,  as  above. 

The  apparatus,  ^^.  1411,  is  for  working  such  sugars  as  require  to  be  previously  mixed 
with  liquid.  It  consists  of  a  vessel  with  a  series  of  steam-pipes  fixed  in  it ;  and  of  a  cen- 
trifugal sieve  and  centrifugal  drum,  both  fixed  upon  the  same  shaft,  which  revolves  in  the 
vessel,  a  is  the  vessel,  in  the  centre  of  which  a  vertical  shaft  6,  is  mounted.  This  shaft 
for  about  two  thirds  of  its  length  from  the  top  is  made  hollow ;  and  upon  it  is  fixed  a 
small  centrifugal  drum  c,  having  a  perforated  periphery,  and  furnished  with  divisions  or 
leaves,  projecting  inward,  to  impart  to  the  fluid  (which  enters  it  through  openings  in  the 
shaft  6),  the  centrifugal  speed  of  the  shaft  The  shaft  h  also  carries  a  sieve  d,  the  meshes 
of  which  are  made  coarser  or  finer  at  pleasure ;  and  for  breaking  any  accretions  of  crystals 
the  sieve  is  furnished  with  a  number  of  metal  points.  A  receptacle  «,  is  formed  at  the 
upper  part  of  the  vessel,  to  receive  any  lumps  that  may  happen  to  be  thrown  over  the 
top  of  the  sieve.  Beneath  the  sieve  several  perforated  steam  pipes/,  are  fixed  for  the 
purpose  of  causing  steam  to  be  brought  in  contact  with  the  particles  of  sugar  which 
pass  through  the  sieve.  Thus: — Communicate  motion  to  the  shaft  6,  and  admit  steam 
to  the  pipes/,  through  the  pipe/,  then  introduce  the  syrup  with  which  the  sugar  is  to 
be  mixed  into  the  drum  c,  through  the  shaft  h.  The  sugar  which  has  been  prepared  by 
crushing  is  deposited  in  the  centre  of  the  sieve,  whence  it  is  thrown  by  the  centrifugal 
action  through  the  meshes  of  the  sieve ;  it  then  descends  through  the  steam  that  issues 
from  the  pipes  /  whereby  it  is  moistened  and  prepared  to  receive  the  syrup,  which  is 
thrown  from  the  drum  c,  and  thus  become  mixed  with  the  sugar. 


Fig.  1412,  is  an  elevation,  partly  in  section,  of  a  vacuum-pan,  with  the  improved  ftp* 
paratus  applied  thereto,  a,  is  the  vacuum-pan^  the  head  h,  of  which  is  connected  by  ft 
copper  pipe  c^  with  a  condenser  d — shown  in  vertical  section  at  Jig.  1413.  The  con- 
denser consists  of  a  metal  cylinder  with  conical  ends,  which  are  separated  from  the 
body  of  the  cylinder  by  plates  e ;  but  a  communication  is  established  between  the  two 
ends  by  a  series  of  copper  pipes/  which  are  inserted  at  top  and  bottom  into  the  plates  «, 
At  the  bottom  of  the  cylinaer  there  is  a  pipe  g,  by  which  cold  water  is  admitted  into 
it ;  and  at  the  top  there  is  a  pipe  A,  through  which  the  water  flows  away.  The  bottom 
of  the  condenser  is  connected  with  a  receiver  i,  by  a  pipe^',  provided  with  a  stop- valve, 
which  can  be  worked  by  means  of  the  crank-handle  *:.  The  receiver  is  furnished  with 
steam-pipes  t^,  for  evaporating  the  water  of  condensation,  as  represented  in  Jig.  1414 — 
which  is  a  plan-view  of  the  receiver  «,  with  the  top  removed.  The  receiver  is  con- 
nected by  a  pipe  I,  with  a  second  condensing  vessel  in,  which  is  divided  longitudinally, 
near  the  top,  by  a  perforated  plate  n  supported  by  vertial  bearers  o.  There  is  a  per- 
forated pipe  p,  at  the  top  of  the  condenser  m,  by  which  cold  water  is  supplied  to  the 
upper  compartment  thereof,  whence  it  descends  in  a  shower  through  the  perforations 
in  the  plate  ti,  and  condenses  the  aqueous  vapor  in  the  lower  compartment  The  con- 
denser m,  is  connected  with  the  exhausting  pumps  by  the  pipe  q. 

The  progress  of  the  operation  is  as  follows : — As  the  vapor  from  the  vacuum-pan 

Products  of  refining  in  Bond.     Rejinery  A. 


Foreign  sugar  received  into 

finery         ... 
Brltiah  refined,  ditto 

28993    1    10 
7306    1    27 
9644    2      8 

re- 

Cwt.  qr. 

47,479    3 
240    0 

lb. 

14 
0 

47,719    3 

14 

45944    1    17 

45944    1    17 
946 

46890    1    17 
240 

47130    1    17 

Delivered  for  exportation  atores, 
tc. : — 

Refined  sugar •  • 

Bastards  -  • 

Treacle 

Raw  sugar  removed  to  other  re. 
finery  ... 

Syrup,  ditto  .  .  - 

Scrapings,  ditto 

Samples         ... 

Total    • 
Deficiency 

Balance 


CwL  qr. 

lb. 

28,993    1 
7,306    1 
9,644    2 

10 

27 

8 

385    2 

284    1 

145    0 

14    0 

14 

7 
10 
23 

46,773    2 
946    0 

15 
27 

47,719    3 

14 

Refinery  B. 


Foreign  sugar  received   into  re. 
finery         .... 
British  refined  (bastard)    • 

56800)41770  (  73-5 
39760       25 

Cwt.  qr.  lb. 

56,485    1    22 
314    0    21 

Delivered  for  exportation  stores, 
tc.:— 

Refined  sugar  ... 
Bastards           ... 
Treacld           ... 

Total 
Deficiency 

Balance  > 

Cwt   qr.  lb. 

41,770    0    26 

1,425    3     4 

12,194    2     4 

66,799    2    15 

■ 

55,390    2     6 
1,409    0     9 

20100    21-5 
17040 

100-0 

3060 

56800)1426  (2-5 
1136 

56,799    2    15 

2900 

56800)121950  (21-4  or  5 
113600 

83500 
56800 

26700 

A»00)140900  (2-5 
11360 

27300 

776 


SUGAR. 


SUGAR. 


777 


"pMses  through  the  condenser  d,  a  portion  of  it  is  condensed  in  the  pipes/  together 
with  the  saccharine  matters,  and  flows  from  the  bottom  of  the  condenser  into  the  re» 
eeiver  «,  in  the  state  of  a  weak  solution  of  sugar.  Steam  being  admitted  into  the  pipes 
t^,  the  heat  thereof  (in  combination  with  the  action  of  the  exhausting  pumps)  evaporatet 
the  solution  to  a  more  concentrated  state;  and  then  it  may  be  drawn  off  through  the 
pipe  r; — air  being  at  the  same  time  admitted  into  the  receiver  through  a  cock  at  i;  to 
supply  the  place  with  liquor  as  it  flows  away.  If  the  pumps  are  kept  in  action  during 
this  part  of  the  process,  a  throttle  yalye  must  be  used  to  close  the  pipe  /. 

Refinery  C. 


flareign  sugur  received 

44)54-7 
22- 
10-7 


Cwt.  qr.  lb. 
8,074      0     3 


Delivered  for  exportation  stores, 
tc.  :— 

Refined  sugar  • 
Bastards 


Treacle 
Samples 


Total 
Deficiency* 

Balance  • 


CwL  qr. 

lb. 

4,396    1 

1,775    1 

8.V>    3 

2    0 

11 
15 

7 
21 

7,080    0 
1.043    3 

26 
5 

8,074    0 

3 

*  Mem. — An  accident  happened  by  tlie  bursting  of  a  boiler 
BEET-ROOT  SU6AK. 

The  physical  characters  which  serve  to  show  that  a  beet-root  is  of  good  quality,  are 
its  being  firm,  brittle,  emitting  a  creaking  noise  when  cut,  and  being  perfectly  sound 
within;  the  degree  of  sweetness  is  also  a  good  indication.  The  45th  degree  of  latitude 
appears  to  be  the  southern  limit  of  the  successful  growth  of  beet  in  reference  to  the  extraction 
of  sugar. 

Extraction  of  Sugar  from  the  Beet.  — The  first  manipulations  to  which  the  beets  are 
exposed,  are  intended  to  clear  them  from  the  adhering  earth  and  stones,  as  well  as  the 
fibrous  roots  and  portions  of  the  neck.  It  is  desirable  to  expose  the  roots,  aAer  this  operation, 
to  the  action  of  a  cylinder  washing-machine. 

The  parenchyma  of  the  beet  is  a  spongy  mass,  whose  cells  are  filled  with  juice.  The 
cellular  tissue  itself,  which  forms  usually  only  a  twentieth  or  twenty-fifth  of  the  whoje 
weight,  consists  of  ligneous  fibre.  Compression  alone,  however  powerful,  is  inadequate 
10  force  out  all  the  liquor  which  this  tissue  contains.  To  efiect  this  object,  the  roots 
must  be  subjected  to  the  action  of  an  instrument  which  will  tear  and  open  up  the 
greatest  possible  number  of  these  cells.  Experiments  have,  indeed,  proved,  that  by  the 
most  considerable  pressure,  not  more  than  40  or  50  per  cent,  in  juice  from  the  beet  can 
be  obtained ;  whilst  the  pulp  procured  by  the  action  of  a  grater  produces  from  75  to  80 
percent. 

1416 

n 


1415 


The  beet-root  rasp  of  Moulfarine  is  represented  in^gx.  1415,  1416-    a,  a,  is  the  frame- 
work of  the  machine ;  6,  the  feed-plate,  made  of  cast  iron,  divided  by  a  ridge  into  two 


parts ;  c,  the  hollow  drum  ;  d,  its  shaft,  upon  either  side  of  whose  peripheiy  nuts  are 
screwed  for  securing  the  saw  blades  e,  e,  which  are  packed  tight  againrt  each  other  by 
means  of  laths  of  wood  ;  /,  is  a  pinion  upon  the  shaft  of  the  drum,  into  which  the  whed 
g  works,  and  which  is  keyed  upon  the  shaft  A;  t,  is  the  driving  rigger ;  Ar,  piller  of  sup- 
port; /,  blocks  of  wood,  with  which  the  workman  pushes  the  beet-roots  against  the  re- 
volving-rasp :  m,  the  chest  for  receiving  the  beet-pap ;  n,  the  wooden  cover  of  the  dram, 
lined  with  sheet  iron.     The  drum  should  make  500  or  600  turns  in  a  minute. 

A  few  years  ago,  M.  Dombasle  introduced  a  process  of  extracting  the  juice  from  the 
beet  without  either  rasping  or  hydraulic  pressure.  The  beets  were  cut  into  thin  slices 
by  a  proper  rotatory  blade  machine;  these  slices  were  put  into  a  macerating  cistern, 
with  about  their  own  bulk  of  water,  at  a  temperature  of  212°  F.  After  half  an  bourns 
maceration,  the  liquor  was  said  to  have  a  density  of  2°  B.,  when  it  was  run  off  into  a 
second  similar  cistern,  upon  other  beet-roots;  from  the  second  it  was  let  into  a  third, 
and  so  on  to  a  fifth ;  by  which  time,  its  density  having  risen  to  5|°,  it  was  ready  for  tte 

{>roce88  of  defecation.  Juice  produced  in  this  way  is  transparent,  and  requires  littlw 
ime  for  its  purification ;  but  it  is  apt  to  ferment,  or  to  have  its  granulating  power  im- 
paired by  the  watery  dilution.  The  process  has  been  accordingly  abandoned  in  most 
establishments. 

I  have  seen  the  following  operations  successfully  executed  in  a  beet-root  factory  near 
Lille,  and  have  since  verified  their  propriety  in  my  own  laboratory  upon  white  beets, 
grown  near  Mitcham  in  Surrey.  My  product  was  nearly  5  per  cent. ;  it  was  very  fair, 
and  large  grained,  like  the  vacuum-pan  sugar  of  Demerara,  but  w^ithout  its  clamminess. 

The  roots  were  washed  by  a  rotatory  movement  upon  a  grating  made  like  an  Archime* 
des'  screw,  formed  round  the  axis  of  a  squirrel-cage  cylinder,  which  was  laid  horizontally 
beneath  the  surface  of  water  in  an  oblong  trough.  It  was  turned  by  hand  rapidly,  witk 
the  intervention  of  a  toothed  wheel  and  pinion.  The  roots,  after  being  sufficiently 
agitated  in  the  water,  were  tossed  out  by  the  rotation  at  the  end  of  the  cyliirfer  farthest 
from  the  winch.  They  were  next  hoisted  in  a  basket  up  through  a  vr^p-hole  into  the 
floor  above,  by  means  of  a  cord  and  pulley  moved  by  mechanical  power;  a  six-horse  steam 
engine,  upon  Woolfe's  expansive  principle,  being  employed  to  do  all  the  heavy  work. 
They  were  here  subjected  to  the  mechanical  grater  (raj?e  mecontgttg),  &ee^g».  1098, 1099, 
which  had,  upon  its  sloping  feed-table,  two  square  holes  for  receivin?  at  least  two  beets 
at  a  time,  which  were  pushed  forwards  by  a  square  block  of  wood  held  in  the  workman's 
hand  by  means  of  a  strap.  The  rasp  was  a  drum,  having  rows  of  straight  saws  placed 
half  an  inch  apart  round  its  periphery,  parallel  to  the  axis,  with  teeth  projecting  about 
I  of  an  inch.  The  space  between  each  pair  of  saws  was  filled  with  a  wedge  of  wood.  The 
steel  slips,  or  saw  plates,  were  half  an  inch  broad,  twelve  inches  long,  and  serrated  on 
both  their  longitudinal  edges,  so  that  when  the  one  line  of  teeth  was  blunted,  the  other 
could  be  turned  out.     The  drum  made  750  turns  per  minute. 

The  pulp  from  the  rasp  fell  into  a  flat  trough  placed  beneath,  whence  it  was  shovelled 
into  small  bags.  Each  bag  had  its  mouth  folded  over,  was  laid  upon  a  wicker  plate,  and 
spread  flat  with  a  rolling-pin.  The  bags  and  hurdles  were  then  piled  in  the  hydraulic 
press.  There  were  three  presses,  of  which  the  two  allotted  to  the  first  pressure  were 
charged  alternately,  and  the  third  was  reserved  for  a  final  and  more  durable  pressure  of 
the  marc.     See  Press,  hydraulic,  and  Stearine  Press. 

The  juice  flowed  over  the  edges  of  the  wicker  plates,  and  fell  into  the  sill-plate  of 
the  press,  which  was  furnished  with  upright  borders,  like  a  tray,  through  whose  front 
side  a  pipe  issued,  that  terminated  in  a  leathern  hose,  for  conducting  the  juice  into  an 
elevatea  cistern  in  the  boiling-house.  Here  one  pound  of  slaked  lime  was  mixed  with 
every  four  hectolitres  (about  88  gallons  imp.)  of  juice.  The  mixture  was  made  to  boil 
for  a  little  while  in  a  round  pan  alongside,  whence  it  was  decanted  into  oblong  flat  filters, 
of  blanket  stuff".  The  filtered  liquor,  which  had  in  general  a  spec,  gravity  of  15<*  £aume 
(about  double  that  of  the  fresh  juice),  was  now  briskly  concentrated  by  boiling,  in  an 
oblong  pan,  till  it  acquired  the  density  of  28°  B.  The  fire  being  damped  with  raw 
coal,  the  sirup  was  run  off"  rapidly  by  a  stopcock  into  a  large  basin  with  a  swing  handle, 
and  immediately  replaced  by  fresh  defecated  liquor.  The  basin  was  carried  by  two  men 
to  the  opposite  side  of  the  boiling-house,  and  emptied  into  a  cistern  set  on  a  high 
platform,  whose  horizontal  discharge-pipe  was  provided  with  a  series  (five)  of  stopcocks, 
placed  respectively  over  five  copper  chests  (inverted  truncated  pyramids),  containing  a 
thick  bed  of  granular  bone  black,  covered  with  a  perforated  copper  plate.  The  hot  sirup 
thus  filtered  had  a  pale  straw-color,  and  was  subsequently  evaporated  in  swing  pans,^g«. 
1406,  1407,  over  a  brisk  fire,  in  quantities  equivalent  to  half  a  cwt.  of  sugar,  or  four 
hectolitres  of  average  juice. 

MAPLE   SUGAR. 

The  manufacture  of  sugar  from  the  juice  of  a  species  of  maple  tree,  which  grows 


778 


SUGAR. 


SUGAR. 


779 


spontaneously  in  many  of  the  uncultivated  parts  of  North  America,  appears  to  hare 
been  first  attempted  about  1752,  by  some  of  the  farmers  of  New  England,  as  a  branch 
Df  rural  economy. 

The  sugar  maple,  the  Jicer  sacc^annttm  of  LinnsBus,  thrives  especially  in  the  States  of 
New  York  and  Pennsylvania,  and  yields  a  larger  proportion  of  sugar  than  that  which 
grows  upon  the  Ohio.  It  is  found  sometimes  in  thickets  which  cover  five  or  six  acrei 
of  land;  but  it  is  more  usually  interspersed  among  other  trees.  They  are  supposed  to 
arrive  at  perfection  in  forty  years. 

The  extraction  of  maple  sugar  is  a  great  resource  to  the  inhabitants  of  districts  far 
removed  from  the  sea;  and  the  process  is  very  simple.  After  selecting  a  spot  among 
surrounding  maple  trees,  a  shed  is  erected,  called  the  sugar-camp^  to  protect  the  boilers 
and  the  operators  from  the  vicissitudes  of  the  weather.  One  or  more  augers,  three 
fourths  of  an  inch  in  diameter ;  small  troughs  for  receiving  the  sap ;  tubes  of  elder  or 
sumach,  8  or  10  inches  long,  laid  open  through  two  thirds  of  their  length,  and  corres- 
ponding in  size  to  the  auger-bits;  pails  for  emptying  the  troughs,  and  carrying  the  sap 
to  the  camp;  boilers  capable  of  holding  15  or  16  gallons;  moulds  for  receiving  the 
sirup  inspissated  to  the  proper  consistence  for  concreting  into  a  loaf  of  sugar ;  and) 
lastly,  hatchets  to  cut  and  cleave  the  fuel,  are  the  principal  utensils  requisite  for  this 
manufacture.     The  whole  of  February  and  beginning  of  March  are  the  sugar  season. 

The  trees  are  bored  obliquely  from  below  upwards,  at  18  or  20  inches  above  the  ground, 
with  two  holes  4  or  5  inches  asunder.  Care  must  be  taken  that  the  auger  penetrates  no 
more  than  half  an  inch  into  the  alburnum,  or  white  bark ;  as  experience  has  proved  that 
a  greater  discharge  of  sap  takes  place  at  this  depth  than  at  any  other.  It  is  also  advisa- 
ble to  perforate  in  the  south  face  of  the  trunk. 

The  trough,  which  contains  from  two  to  three  gallons,  and  is  made  commonly  dt 
white  pine,  is  set  on  the  ground  at  the  foot  of  each  tree,  to  receive  the  sap  which  flowi 
through  the  two  tubes  inserted  into  the  holes  made  with  the  auger ;  it  is  collected  together 
daily,  and  carried  to  the  camp,  where  it  is  poured  into  casks,  out  of  which  the  boilers 
are  supplied.  In  every  case,  it  ought  to  be  boiled  within  the  course  of  two  or  three  days 
from  flowing  out  of  the  tree,  as  it  is  liable  to  run  quickly  into  fermentation,  if  the  weather 
become  mild.  The  evaporation  is  urged  by  an  active  fire,  with  careful  skimming  during 
the  boiling  ;  and  the  pot  is  continually  replenished  with  more  sap,  till  a  large  body  has 
at  length  assumed  a  sirupy  consistence.  It  is  then  allowed  to  cool,  and  passed  through  a 
woollen  cloth,  to  free  it  from  impurities. 

The  sirup  is  transferred  into  a  boiler  t*  three  fourths  of  its  capacity,  and  it  is  urged 
with  a  brisk  fire,  till  it  acquires  the  requisite  consistence  for  being  poured  into  the  moulds 
or  troughs  prepared  to  receive  it.  This  point  is  ascertained,  as  usual,  by  its  exhibiting 
a  granular  aspect,  when  a  few  drops  are  drawn  out  into  a  thread  between  the  finger  and 
the  thumb.  If  in  the  course  of  the  last  boiling,  the  liquor  froth  up  considerably,  a  small 
bit  of  butter  or  fat  is  thrown  into  it.  After  the  molasses  have  been  drained  from  the  con- 
creted loaves,  the  sugar  is  not  at  all  deliquescent,  like  equally  brown  sugar  from  the  cane. 
Maple  sugar  is  in  ta^^te  equally  agreeable  with  cane  sugar,  and  it  sweetens  as  well.  When 
refined,  it  is  equally  fair  with  the  loaf  sugar  of  Europe. 

The  period  during  which  the  trees  discharge  their  juices  is  limited  to  about  six  weeks. 
Towards  the  end  of  the  flow,  it  is  less  abundant,  less  saccharine,  and  "Eoro  difiicult  to  be 
crystallized. 

Sugar  op  potatoes,  grapes,  or  starch.  About  eight  years  ago  a  sample  of  sweet 
mucilaginous  liquid  was  sent  to  me  for  analysis,  by  the  Honorable  the  Commissioners 
of  Customs.  It  was  part  of  a  quantity  imported  in  casks  at  Hull,  from  Rotterdam.  It 
was  called  by  the  importers,  "  Vegetable  Juice."  I  found  it  to  be  imperfectly  sacchari- 
fiied  starch  or  fecula ;  and,  on  my  reporting  it  as  such,  it  was  admitted  at  a  moderate 
rate  of  duty. 

Some  months  after  I  received  a  sample  of  a  similar  liquid  from  the  importer  at  Hull, 
with  a  request  that  I  would  examine  it  chemically.  He  informed  me,  that  an  im- 
portation, just  made  by  him  of  30  casks  of  it,  had  been  detained  by  orders  of  the 
Excise,  till  the  sugar  duty  of  25«.  per  cwt  of  solid  matter  it  contained  was  paid  upon 
it  It  was  of  specific  gravity  1*362,  and  contained  SO  per  cent  of  ill-saccharified 
fecula. 

In  the  interval  between  the  first  importation  and  the  second,  an  Act  of  Parliament 
had  been  obtained  for  placing  every  kind  of  sugar,  from  whatever  material  it  was 
formed,  under  the  provisions  of  the  "  Beet-root  Sugar  Bill."  As  the  saccharometer 
tables,  subservient  to  the  levying  of  the  excise  duties,  under  this  Act,  were  constructed 
by  me,  at  the  request  of  the  President  of  the  Board  of  Trade,  I  well  know  that  50  per 
cent  of  the  syrup  of  the  beet-root  was  deducted  as  a  waste  product  because  beet-root 
molasses  is  too  crude  an  article  for  the  use  of  man.  Well  saccharified  starch  paste, 
however,  constitutes  a  syrup,  poor  indeed  in  sweetness  when  compared  with  cane  syrup, 
or  that  of  the  beet-root  \  but  then  it  does  not  spontaneously  blacken  into  molasses,  by 


eyaporation,  as  solutions  of  ordinary  sugar  never  fail  to  do  when  iJiey  are  eoneentrated, 
even  with  great  care.  Hence  tlje  residuary  syrups  of  saccharified  fecula  may  be  all 
worked  up  into  a  tolerably  white  granular  mass,  which,  being  crushed,  is  used  by 
greedy  grocers  to  mix  with  dark-brown  bastard  sugars,  to  improve  their  color. 

It  ie  only  within  a  few  years  that  sugar  has  been  in  this  country  manufactured  from 
potato  starch  to  any  extent  though  it  has  been  long  an  object  of  commercial  enterprise 
in  France,  Belgium,  and  Holland,  where  the  large  coarse  potatoes  are  used  for  this 
purpose.     The  raw  material  must  be  very  cheap  there,  as  well  as  the  labor ;  for  potato 
flour  or  starch,  for  conversion  into  sugar,   has  been  imported  from  the  continent  into 
this  country  in  large  quantities,  and  sold  in  London  at  the  low  price  of  10*.  per  cwt. 

The  process  usually  followed  by  the  potato-sugar  makers,  is  to  mix  100  gallons  of 
boiling  water  with  every  112  lbs.  of  the  fecula,  and  2  lbs.  of  the  strongest  sulphuric 
acid.  This  mixture  is  boiled  about  12  hours  in  a  large  vat,  made  of  white  deal,  having 
pipes  laid  along  its  bottom,  which  are  connected  with  a  high  pressure  steam-boiler. 
After  being  thus  saccharified,  the  acid  liquid  is  neutralized  with  chalk,  filtered,  and 
then  evaporated  to  the  density  of  about  1  -300,  at  the  boiling  temperature,  or  exactly 
1*342,  when  cooled  to  60^.  When  syrup  of  this  density  is  left  in  repose  for  some  days, 
it  concretes  altogether  into  crystalline  tufts,  and  forms  an  apparently  dry  solid,  of  spe- 
cific gravity  1*39.  When  this  is  exposed  to  the  heat  of  220°,  it  fuses  into  a  liquid 
nearly  as  thin  as  water;  on  cooling  to  150°,  it  takes  the  consistence  of  honey,  and  at 
100**  F.  it  has  that  of  a  viscid  varnish.  It  must  be  left  a  considerable  time  at  rest  be- 
fore it  recovers  its  granular  state.  When  heated  to  270°,  it  boils  briskly,  gives  ofi"  one 
tenth  of  its  weight  of  water,  and  concretes,  on  cooling,  into  a  bright  yellow,  brittle,  but 
very  deliquescent  mass,  like  barley  sugar.  If  the  syrup  be  concentrated  to  a  much 
greater  density  than  1*340,  as  to  1*362,  or  if  it  be  left  faintly  acidulous,  in  eithet  tase 
it  will  not  granulate,  but  will  remain  either  a  viscid  magma  or  become  a  con<*;ete  mass, 
which  may  indeed  be  pulverized,  though  it  is  so  deliquescent  as  to  be  unfit  for  the 
adulteration  of  raw  sugar.  The  Hull  juice  is  in  this  predicament,  and  is  therefore,  in 
my  opinion,  hardly  amenable  to  the  new  sugar  law,  as  it  can  not  by  any  means  be 
worked  up  into  even  the  semblance  of  sugar. 

Good  Muscovado  sugar,  from  Jamaica,  fuses  only  when  heated  to  280°,  but  it  tarns 
immediately  dark  brown,  from  the  disengagement  of  some  of  its  carbon,  at  that  tem- 
perature, and  becomes,  in  fact,  the  substances  called  "  caramel"  by  the  French,  which 
is  used  for  coloring  brandies,  white  wines,  and  liqueurs. 

Thus  we  see  that  starch  or  grape-sugar  is  well  distinguished  from  cane-sugar,  by  its 
fusibility,  at  a  moderate  heat,  and  its  inalterability  at  a  pretty  high  heat.  Its  sweet- 
ening power  is  only  two  fifths  of  that  of  ordinary  sugar.  A  good  criterion  of  incom- 
pletely formed  starch-sugar  is,  its  resisting  the  action  oi  sulphuric  acid,  while  perfectly 
saccharified  starch  or  cane-sugar  is  readily  decomposed  by  it.  If,  to  a  strong  solution 
of  imperfectly  saccharified  grape-sugar,  nearly  boiling  hot,  one  drop  of  strong  sulphuric 
acid  be  let  fall,  no  perceptible  change  will  ensue,  but  if  the  acid  be  dropped  into  solu- 
tions of  either  of  the  other  two  sugars,  black  carbonaceous  particles  will  make  theii 
appearance. 

The  article  which  was  lately  detained  by  the  Excise,  for  the  high  duties,  at  Hull,  is 
not  affected  by  sulphuric  acid,  like  the  solutions  of  cane-sugar,  and  of  the  weU-made 
potato-sugar  of  London ;  and  for  this  reason  I  gave  my  opinion  in  favor  of  admitting 
the  so-called  vegetable  juice  at  a  moderate  rate  of  duty. 

I  submitted  the  solid  matter,  obtained  by  evaporating  the  Hull  juice,  to  nltimate 
analysis,  by  peroxide  of  copper,  in  a  combustion  tube,  with  all  the  requisite  precau- 
tions, and  obtained,  in  one  experiment,  37  per  cent,  of  carbon ;  and  in  another  38  per, 
cent.,  when  the  substance  had  been  dried  in  an  air  bath,  heated  to  275°.  The  differ- 
ence to  100,  is  hydrogen  and  oxygen,  in  the  proportion  to  form  water.  Now  this  is 
nearly  the  constitution  of  starch.  Cane-sugar  contains  about  5  per  cent,  more  carbon, 
whereby  it  readily  evolves  this  black  element,  by  the  action  of  heat  or  sulphuric  acid. 

An  ingenious  memoir,  by  Mr.  Trommer,  upon  the  distinguishing  criteria  of  gum, 
dextrine,  grape-sugar,  ar.l  cane-sugar,  has  been  published  in  the  39th  volume  of  the 
"  Annalen  der  Chemie  und  Pharmacie."  I  have  repeated  his  experiments,  and  find 
them  to  give  correct  results,  when  modified  in  a  certain  way.  His  general  plan  is  to 
expose  the  hydrate  of  copper  to  the  action  of  solutions  of  the  above-mentioned  vege- 
table products.  He  first  renders  the  solution  alkaline,  then  adds  solution  of  sulphate 
of  copper  to  it,  and  either  heats  the  mixture  or  leaves  it  for  some  time  in  the 
cold.  By  pursuing  his  directions,  I  encountered  contradictory  results ;  but,  by  the 
following  method,  I  have  secured  uniform  success,  in  applying  the  criteria,  and  have 
even  arrived  at  a  method  of  determining,  by  a  direct  test,  the  quantity  of  sugar  in 
diabetic  urine. 

I  dissolve  a  weighed  portion  of  sulphate  of  copper  in  a  measured  quantity  of  water, 
and  make  the  solution  faintly  alkaline,  as  tested  with  turmeric  paper,  by  the  addition 


7^ 


SUGAR. 


of  potash  Ije,  in  the  cold;  for  if  the  mixture  be  hot,  a  portion  of  the  disengaged  green 
hydrate  of  copper  is  converted  into  black  oxide.  This  mixture  being  always  agitated 
before  applying  it,  forms  the  test  liquor.  If  a  few  drops  of  it  be  introduced  into  a 
lolution  of  gum,  no  change  ensues  on  the  hydrate  of  copper,  even  at  a  boiling  heat, 
which  9how8  that  a  gummate  of  copper  is  formed,  which  resists  decomposition ;  but 
the  cupreous  mixture,  without  the  gum,  is  rapidly  blackened  at  the  boiling  tempera- 
ture. I  do  not  find  that  the  gummate  is  re-dissolved  by  an  excess  of  water,  as  'fi'om- 
mer  affirms. 

Starch  and  tragacants  comport  like  gnm,  in  which  respect  I  agree  with  Trommer. 
Starch,  however,  possesses  already  a  perfect  criterion,  in  iodine  water.  Mr.  Trommer 
Bays,  that  solution  of  dextrine  affords  a  deep  glue-colored  liquid,  without  a  trace  of 
precipitate ;  and  that  when  his  mixture  is  heated  to  85°  C,  it  deposites  red  grains  of 
protoxide  of  copper,  soluble  in  muriatic  acid.  I  think  these  phenomena  are  dependant, 
in  some  measure,  upon  the  degree  of  alkaline  excess  in  the  mixture.  I  find,  the  solu- 
tion of  dextrine,  treated  in  my  way,  hardly  changes  in  the  cold ;  but  when  heated 
slightly,  it  becomes  green,  and  by  brisk  boiling  an  olive  tint  is  produced.  It  thus  be- 
trays its  tendency  of  transition  into  sugar. 

Solution  of  cane-sugar,  similarly  treated,  undergoes  no  change  in  the  cold  at  the  end 
of  two  days ;  and  very  little  change  of  color  even  at  a  boiling  heat,  if  not  too  concen- 
trated. Cane-sugar,  treated  by  Trommer  in  his  way,  becomes  of  a  deep  blue;  it  can 
be  boiled  by  potash  in  excess,  without  any  separation  of  orange-red  oxide  of  copper. 

Starch  or  grape-sugar  has  a  marvellous  power  of  reducing  the  green  hydrate  of 
copper  to  the  orange  oxide.  I  find,  however,  that  it  will  not  act  upon  the  pure  blue 
hydrate,  even  when  recently  precipitated ;  it  needs  the  addition,  in  every  case,  of  a 
small  portion  of  alkali.  Yet  ammonia  does  not  seem  to  serve  the  purpose;  for,  in 
using  the  ammonia-sulphate  of  copper,  in  solution,  I  obtained  unsatisfactory  results 
with  the  above  vegetable  products. 

The  black  oxide  of  copper  is  not  affected  by  being  boiled  in  solution  of  starch-sugai. 

**  If  solution  of  grape-sugar,"  says  Trommer,  "  and  potash,  be  treated  with  a  solution 

of  sulphate   of  copper,  till  the  separated  hydrate  is  redissolved,  a  precipitate  of  red 

oxide  will  soon  take  place,  at  common  temperatures,  but  it  immediately  forms,  if  the 


mixture  is  heated.    A  liquid  containing 


of  grape-sugar,  even  one  millionth 


„  ,  .  100   0^ 

part,"  says  he,  "  gives  a  perceptible  tinge  (orange),  if  the  light  is  let  fall  upon  it."  To 
obtain  such  a  minute  result,  very  great  nicety  must  be  used  in  the  dose  of  alkali,  which 
I  have  found  it  extremely  difficult  to  hit.  With  my  regulated  alkaline  mixture,  how- 
ever, I  never  fail  of  discovering  an  exceedingly  small  proportion  of  starch-sugar,  even 
when  mixed  with  Muscovado  sugar;  and  thus  an  excellent  method  is  afforded  of  de- 
tecting the  frauds  of  the  grocers. 

I  find  that  manna  deoxidizes  the  green  hydrate  of  copper  slowly  when  heated,  but 
not  nearly  to  the  same  extent  as  grape-sugai*,  which  reduces  it  rapidly  to  the  orarge 
oxide. 

If  an  excess  of  the  hydrate  of  copper  test  be  used,  there  will  he  a  deposite  of  green 
hydrate  at  the  bottom  of  the  vessel,  under  the  orange  oxide. 

To  apply  these  researches  to  the  sugar  of  diabetic  urine :  This  should  first  be 
boiled  briskly  to  decompose  the  urea,  and  to  dissipate  its  elements  in  the  form  of  am- 
monia, as  well  as  to  concentrate  the  saccharine  matter,  whereby  the  test  becomes  more 
efficacious.  Then  add  to  the  boiling  urine,  in  a  few  drops  at  a  time,  the  cupreous 
mixture,  containing  a  known  quantity  of  sulphate  of  copper,  till  the  whole  assumes  a 
greenish  tint,  and  continue  the  heat  until  the  color  becomes  bright  orange.  Should 
it  remain  green,  it  is  a  proof  that  more  hydrate  of  copper  has  been  introduced  than  has 
been  equivalent  to  the  deoxidizing  power  of  the  starch-sugar.  I  have  found  that  one 
grain  of  sulphate  of  copper  in  solution,  supersaturated  very  slightly  with  potash,  is  de- 
composed with  the  production  of  orange  protoxide,  by  about  3  grains  of  potato-sugar; 
or,  more  exactly,  30  parts  of  the  said  sulphate,  in  the  state  of  an  alkaline  hydrate  of 
copper,  pass  altogether  into  the  state  of  orange  oxide,  by  means  of  100  parts  of  granular 
•tarch-sugar.  Thus,  for  every  3  grains  of  sulphate  so  changed,  10  grains  of  sugar 
may  be  estimated  to  exist  in  diabetic  urine. 

Acetate  of  copper  may  be  used  in  the  above  experiments,  but  it  is  not  so  good  as  the 
sulphate.     The  chloride  of  copper  does  not  answer. 

Specific  gravity  is  also  an  important  criterion,  applied  to  sugars ;  that  of  the  cant 
and  beet-root  is  1-577 ;  that  of  starch-sugar,  in  crystalline  tufts,  is  1-39,  or  perhaps 
1-40,  as  it  varies  a  little  with  its  state  of  dryness.  At  1-342,  syrup  of  the  cane  contains 
70  per  cent,  of  sugar ;  at  the  same  density,  syrup  of  starch-sugar  contains  75|  per  cent, 
of  concrete  matter,  dried  at  260°  F.,  and  therefore  freed  from  the  10  per  cent,  of 
water  which  it  contains  in  the  granular  state.  Thus,  another  distinction  is  obtained 
between  the  two  sugars,  in  the  relative  densities  of  their  solutions,  at  like  saccharine 
contents  per  cent. 


SUGAR. 


781 


A  very  simple  method  of  improving  the  quality  of  sugar  has  been  proposed  by 
Messrs.  Oxland,  of  Plymouth,  chemists,  for  defecating  the  juice  of  beet-root  and 
of  the  cane.  It  consists  in  the  use  of  acetate  of  alumina,  of  which  they  say  that  four 
pounds  of  the  earth  dissolved  in  acetic  acid  are  sufficient  for  one  ton  of  Jamaica  sugar, 
without  any  peculiarity  of  treatment  in  the  boiling  or  filtration.  I  should  fear  that 
the  acid  might  be  apt  to  weaken  the  grain  or  crystalline  force  of  the  sugar.  When 
nearly  all  the  acetic  acid  is  driven  off  by  the  boiling  of  the  syrup,  a  solution  of  tan, 
made  by  digesting  1  pound  of  crushed  valonia  in  2  gallons  of  hot  water,  is  filtered  hot 
into  the  syrup. 

Fermentable  property  of  different  kinds  of  Sugar.  There  is  a  remarkable  difference 
between  the  fermentable  property  of  cane  sugar  and  grape  sugar,  which  has  not  hitherto 
been  sufficiently  noticed,  no  mention  being  made  of  it  in  chemical  works.  It  is,  that  s 
solution  of  grape  sugar  requires  but  a  very  small  quantity  of  ferment  to  induce  alcoholic 
fermentation,  while  solution  of  cane  sugar  requires  a  large  quantity.  When  a  solution 
is  made  of  the  same  quantities  of  cane  sugar  and  grape  sugar  in  equal  proportions  of 
distilled  water,  it  will  be  necessary  to  add  at  least  eight  times  as  much  of  the  same 
ferment  to  induce  alcoholic  fermentation  in  the  solution  of  cane  sugar  as  in  that  of 
grape  sugar. 

Under  the  action  of  a  larger  quantity  of  ferment,  cane  sugar  is  transformed  into 
grape  susar,  and  this  latter  appears  to  be  the  only  substance  susceptible  of  being  de- 
composed by  ferment  into  carbonic  acid  and  alcohol. 

If  a  solution  of  cane  sugar  be  brought  into  the  state  of  alcoholic  fermentation,  and 
the  action  be  stopped  some  time  before  the  decomposition  of  the  sugar  is  completed,  by 
the  addition  of  a  large  quantity  of  strong  alcohol,  it  will  be  found  that  the  remaining 
undecomposed  sugar  has  been  transformed  into  grape  sugar. 

The  fermentable  property  of  sugar  depends  then  upon  the  same  causes  as  that  of 
starch,  several  kinds  of  gum,  and  sugar  of  milk.  These  substances  are  transformed 
into  grape  sugar  under  the  influence  of  different  agents ;  but  of  all  vegetable  matters 
susceptible  of  undergoing  this  transformation,  grape  sugar  is  undoubtedly  that  in  which 
the  change  is  eflfected  with  the  greatest  ease  and  promptitude.  Indeed,  it  so  readily 
undergoes  the  alcoholic  fermentation  that  it  has  been  classed  among  fermentable 
sugars,  but  it  has  no  more  right  to  this  title  than  starch,  several  kinds  of  gum,  and 
sugar  of  milk. 

Another  invention  of  Messrs.  Oxland  for  improvements  in  the  manufacture  and  re- 
fining of  sugar  (patented  in  May,  1851),  consists  in  the  use  of  phosphoric  acid  in  a  com- 
bined state  for  defecating  saccharine  liquids,  or  solutions  of  sugar,  and  removing  the 
color  of  the  same.  On  the  26th  of  April,  1849,  the  present  patentees  obtained  a  patent 
for  defecating  and  removing  the  color  from  solutions  of  sugar  by  the  employment  of 
acetate  of  alumina.  In  the  specification  of  such  patent,  lime  was  directed  to  be  used 
for  effecting  the  separation  of  the  alumina ;  but  it  has  been  found  that,  even  when  care 
is  observed,  some  alumina  is  liable  to  be  left  in  solution.  When  acetate  of  alumina  and 
lime  have  been  used,  the  patentees  effect  the  removal  of  the  remaining  alumina  by  the 
use  of  superphosphate  of  alumina  or  superphosphate  of  lime,  by  simply  adding  a  small 
quantity  of  either  of  these  substances  to  the  syrup  after  the  completion  of  the  process 
with  acetate  of  alumina,  as  described  in  the  former  specification,  then  boiling  for  two 
or  three  minutes,  carefully  neutralizing  the  excess  of  acid,  by  the  addition  of  aluminate 
of  lime,  saccharate  of  lime,  lime  of  water,  or  milk  of  lime ;  and,  when  it  has  been 
ascertained  that  alumina  is  completely  separated,  completing  the  process  in  the  manner 
described  in  the  former  specification. 

In  place  of  using  acetate  of  alumina,  either  alone  or  combined  with  phosphoric  acid, 
a6  above  explained,  phosphates  may  be  employed  directly ;  and  they  are  capable  of  pro- 
ducing similar  effects  to  those  resulting  from  the  use  of  acetate  of  alumina,  with  the 
advantage  that  the  whole  of  the  agent  employed  is  separated  from  the  saccharine 
matters.  In  treating  a  saccharine  liquid,  or  solution  of  sugar,  (say,  for  example,  an 
ordinary  sample  of  Mauritius  sugar),  the  patentees  dissolve  it  by  blowing-up  with 
steam  in  the  usual  wav,  but  avoiding  the  use  of  blood,  and  adding  a  soluble  phosphate 
to  the  water  employea  ;  if  crystallized  phosphate  of  soda  be  used,  it  should  be  in  the 

f)roportion  of  one  pound  ana  a  half  thereof  for  each  ton  of  sugar.  The  saccharine 
iquid  is  brought  to  the  boiling  point, — any  acidity  being  neutralized  with  aluminate 
of  lime,  saccharate  of  lime,  lime  water,  or  milk  of  lime ;  and  then  the  syrup  thus 
obtained  (which  will  be  of  the  specific  gravity  of  from  25**  to  30**  Baum^)  is  passed 
through  the  ordinary  bag-filters.  The  sugar  is,  by  this  means,  thoroughly  defe- 
cated,— the  feculent  matters  being  left  in  the  bags,  from  which  the  last  trace  of  sugar 
may  be  removed  by  passing  clean  water  through  them.  The  weak  solutions  obtained  in 
this  way  may  be  used  for  blowing  up  fresh  quantities  of  raw  sugar.  As  part  of  the 
color  is  removed  from  the  syrup  by  the  above  described  operation,  it  may  be  considered 
sufficient  treatment  previous  to  boiling  in  the  vacuum-pan,  or  otherwise,  for  crystalliza- 


782 


SUGAR. 


SUGAR. 


783 


tl     1 


tion  ;  but  a  farther  amount  of  color  may  be  removed  by  the  use  of  from  6  to  8  per 
cent,  or  more,  of  hydrate  of  alumina  (which  has  been  dried  at  a  temperature  of  212° 
Fahr.,)  diffused  through  the  water  used  in  blowing  up  the  sugar ;  and,  by  this  means, 
the  use  of  animal  charcoal  will  be  rendered  unnecessary.  The  residuary  alumina  left 
in  the  filter  bags,  after  the  whole  of  the  saccharine  matter  has  been  washed  out,  may 
be  dried,  and  the  organic  matter  removed  by  ignition  ;  and,  after  further  washing,  to 
remove  any  residuary  soluble  saline  substance,  it  may  be  employed  for  manufacturing 
hydrate  or  superphosphate  of  alumina ;  or,  after  the  first-mentioned  washing,  previous 
to  ignition,  it  may  be  used  over  again,  with  the  addition  of  a  further  quantity  of  hy- 
drate of  alumina. 

When  superphosphate  of  alumina  is  used,  it  is  mixed,  in  solution,  with  the  water 
Tised  in  blowing-up  the  raw  sugar,  in  the  proportion  of  six  pounds  of  alumina  dissolved 
in  phosphoric  acid  for  each  ton  of  sugar;  and  while  the  syrup  (at  from  25^  to  30° 
Baume),  is  being  brought  to  the  boiling  point,  any  acidity  is  neutralized  by  the  addition 
of  aluminate  of  lime,  saccharate  of  lime,  lime  water,  or  milk  of  lime.  The  syrup  is 
then  passed  through  the  bag-filters,  and  the  clear  syrup  conducted  into  the  receiver 
that  supplies  the  vacuum  or  other  boiling  pan.  The  subsequent  operations  are  the 
same  as  in  the  old  plan  of  working.  The  matters  left  in  the  filter-bags  are  treated  aa 
above  described,  to  remove  any  remaining  saccharine  matter. 

The  patentees  prepare  the  superphosphate  of  alumina  by  dissolving  alumina  in 
phosphoric  acid,  in  the  following  manner: — They  burn  bones  white,  grind  them  to  fine 
powder,  and  digest  the  product  in  sufiicient  muriatic  acid  for  the  solution  of  the  car- 
bonate of  lime  only ;  and  then  they  dry  the  residue,  after  carefully  washing  it,  to  remove 
every  trace  of  soluble  matter.  To  a  given  weight  of  this  residue,  mixed  with  enough 
"Water  to  make  a  thin  paste  (in  a  shallow  earthenware  tank  or  vessel),  they  add  a 
quantity  of  pure  sulphuric  acid,  sufficient  to  combine  with  nearly  all  the  lime  present, 
«.  e.,  all  except  2  or  3  per  cent. ;  stirring  the  mixture  well  and  keeping  it  warm  (say 
above  90°  Fahr.),  for  about  24  hours,  and  after  this  they  lixiviate  the  mass  with  water 
until  all  the  soluble  matters  are  separated  from  the  sulphate  of  lime.  The  strong 
liquors,  obtained  in  this  way,  may  be  used  for  combining  with  alumina,  and  the  weak 
solutions  for  lixiviating  fresh  quantities  of  phosphoric  acid  in  course  of  manufacture. 
When  alumina  is  digested  in  the  phosphoric  acid,  produced  in  the  manner  above  de- 
scribed, phosphate  of  alumina,  insoluble  in  water,  is  first  formed;  and  by  dissolving 
this  in  a  quantity  of  phosphoric  acid  sufficient  only  for  that  purpose,  superphosphate  of 
alumina  is  obtained,  which  should  be  filtered  previous  to  use. 

Aluminate  of  lime  is  prepared  by  dissolving  alumina  in  caustic  potash  or  soda,  and 
then  hy  the  addition  of  lime  water  or  milk  of  lime,  precipitating  aluminate  of  lime, 
which  is  to  be  carefully  washed.  When  required  for  use,  the  patentees  diffuse  the 
aluminate  of  lime  through  water,  and  they  prefer  to  employ  it  instead  of  saccharate  of 
lime,  or  milk  of  lime  or  lime  water. 

When  making  sugar  from  the  cane,  they  defecate  the  juice  with  aluminate  of  lime 
in  the  usual  way,  neutralizing  any  excess  of  lime  with  superphosphate  of  alumina  or 
superphosphate  of  lime ;  then,  after  filtering  and  concentrating  the  filtered  liquid  to 
firom  25°  to  30°  Baume,  they  treat  the  syrup  with  phosphate  of  soda  in  the  same  man- 
ner as  described  with  respect  to  raw  sugars;  and  after  a  second  filtration,  they  boil  in 
the  usual  way. 

In  the  manufacture  and  refining  of  beet-root  sugar,  they  proceed  as  above  described 
for  cane  sugar,  only  using  a  larger  quantity  of  aluminate  of  lime  or  milk  of  lime  in  the 
first  defecation. 

The  patentees  state  that  thev  do  not  confine  themselves  to  the  details  above  given, 
Dr  to  the  phosphates  mentioned,  as  others  may  be  substituted;  but  what  they  claim  is, 
the  employment  of  phosphoric  acid  in  a  combined  state,  as  above  described.— -i^ew- 
ton  s  Journal,  vol  xl.,  p.  27. 

Sugar  tested  hy  bichromate  of  potash.  If  a  thick  pure  cane  sugar  syrup  be  mixed 
w-ith  a  boiling  solution  of  bichromate  of  potash  in  a  test  tube,  and  then  withdrawn 
from  the  heat,  a  deep  green  color  will  appear,  especially  on  dilution  with  water. 
Other  kinds  of  sugar  remain  indifferent  to  the  bichromate.  No  change  takes  place  in 
It  with  starch  sugar,  and  if  this  be  mixed  with  cane  sugar,  it  protects  the  latter  from 
being  colored  a  dark  green.  Nitrate  of  cobalt  added  to  cane  sugar  alkalized  produces 
a  bluish  violate  precipitate ;  but  not  with  an  alkalized  (potash)  grape  8ugar.--i2«.'A. 


SvoAB  in  Four  Ports  of  Gbkat  BarrAm,  for  the  Ten  Months  ending  Slst  October,  1851 

and  1852.* 


British 
Plantation. 
West  India     •          .          . 
Mauritius 
East  Indta      • 

Total  British  Plantation      - 

Foreign. 
Manilla,  &c.    ... 
Brazil  .          .          .          . 
Cuba    .          .          .          . 
Porto  Rico,  tc. 

Total  Foreign 

Total  British  Plantation 

Total  Sugar  ... 

Molasses 

(reduced  to  Sugar) 

Total    -          .          .          . 

Import.         | 

Duty  Paid.      j 

Export. 

Stock.          | 

1851. 

1852. 

1851. 

1852. 

1851. 

1&52. 

1851. 

1852. 

Tons. 

120,800 

45,400 

54,600 

Tons. 

143,300 

49,000 

49,500 

Tons. 
93,800 
38,400 
50,300 

Tons. 

136,400 
47,100 
61,800 

Tons. 

Tons. 

Tons. 
41,000 
14,700 
28,800 

Tons. 
40,100 
14,700 
24,900 

220,800 

241,800 

187,500 

245,300 

— 

— 

84,500 

79,100 

12,700 
34,500 
38,800 
17,300 

5,800 
11,400 
20,400 

6,600 

3,300 
11,600 
25.100 
15,700 

1,000 

1,900 

15,2(t0 

7,000 

5,600 
7,000 
4,800 
1,400 

4,100 
8,600 
9,400 
3,100 

11,200 

25.100 

27.500 

6,800 

8,500 
16,600 
20,700 

3,500 

103,300 
220,800 

44,200 
241,800 

55,700 
187,500 

2.5,100 
245,300 

270,400 

14,600 

18,800 

25,200 

70,600 
84,500 

49,300 
79,100 

324,100 
16,300 

286,000 
11,300 

243,200 
15,500 

18,800 

25,200 

155,100 
11,800 

128,400 
6,000 

340,400 

297,300 

258,700 

285,000 

18,800 

25,200 

166,900 

134,400 

SuOAB  in  EuROPr^  including  Gbkat  Betfain,  for  the  Ten  Months  ending  3l8t  October, 

1860,  1851,  and  1852. 


Holland        .  .  . 

Antwerp       .  .  . 

Hamburgh    .  .  • 

Bremen        .  .  . 

Havre    .       .  .  . 

Trieste  .       .  .  . 

Genua    .       .  .  . 

Leghorn       .  .  . 

Total  Continent  . 
Great  Britain 

Total  Europe  • 


Import. 

Stock. 

1850. 

1851. 

1852. 

1850. 

1851. 

1352. 

Tons. 

Tons. 

Tons. 

Tons. 

Tons. 

Tons. 

95,600 

97,660 

86,100 

8,400 

13.710 

6,400 

30,720 

13,660 

19,540 

2,060 

3,870 

2,080 

25,250 

23,500 

20,250 

5,750 

8,750 

4,250 

6.500 

7,750 

4,460 

300 

1,300 

300 

23,650 

20,360 

37,120 

4,770 

2,830 

10,670 

43,870 

26,490 

39,270 

18,810 

10,310 

10,410 

17,230 

8,290 

14,630 

4.690 

3,300 

2,780 

7,050 

3,540 

7,330 

1,360 

810 

850 

249,870 

201,250 

228.700 

46,140 

44.880 

37,740 

290,780 

340,400 

297,300 

118,540 

166,900 

134,400 

540,650 

541,650     ' 

526,000 

164,680 

211,780 

172,140 

Sugar  in  United  Kingdom  (refined,  or  equal  to  refined). 


Years. 

Import. 

Consumption. 

Export 

Tons. 

Tons. 

Tons. 

1847 

4,820 

1,260 

2,930 

1848 

11,040 

2,220 

6,130 

1849 

15.220 

8,070 

9,900 

1850 

17,890 

5,8^40 

4,620 

1851 

21,930 

16,930 

2,650 

Molasses. 


Years. 

Import 

Consumption. 

Export 

1847 
1848 
1849 
1860 
1851 

Tons. 

47,490 

25,890 

63.130 

45,250 

89,560 

Tons. 

31,930 

31,850 

40,620 

45,880 

33,650 

The  exports  of  mo- 
lasses are  very  in- 
significant. 

*  For  these  important  tables,  I  am  indebted  to  James  Cook,  Esq.,  of  Mbicing  Lane. 


784 


SUGAR. 


SUGAR. 


785 


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786 


SUGAR  OF  LEAD. 

Sugar  in  United  Kingdom  (unrefined,  or  not  equal  to  refined). 


SULPHATE  OF  IRON. 


787 


Year*. 

Imports. 

Consumption. 

Exports 
Baw. 

Refined  in 
Bond. 

Tons. 

Tons. 

Tons. 

Tona 

1840 

201,790 

179,740 

11,480 

11,760 

1841 

245,260 

202,880 

21,270 

15,610 

1842 

237,800 

193,420 

20,090 

13,740 

1843 

261,030 

201,410 

28,680 

13,000 

1844 

244,000 

206,470 

16,690 

10,960 

1845 

291,040 

242,830 

30,800 

13,690 

1846 

281,130 

261,010 

12,040 

11,880 

1847 

410,480 

288,980 

40,200 

11,460 

1848 

343,600 

307,120 

16,630 

12,440 

1849 

346,290 

296,110 

27,930 

11,160 

1850 

314,570 

804,570 

18,490 

10,460 

1851 

397,010 

312,770 

15,340 

12,930 

Months 
1852. 

England. 

Hamburg. 

France. 

United 
States. 

Holland. 

West 
Indies. 

ChilL 

Callao. 

Total. 

January 

February 

March 

April 

May 

June 

July 

August 

September 

Ql9. 

37,141 

19,527 
22,065 
46,493 
5,500 
42,169 
64,096 
14,777 

Qls. 

4,002 
7,040 

25,130 
2,000 

14,628 

Qls. 

4,211 
11,000 

12,570 

6,029 
7.000 
5,600 

Qk 

6,126 
17,633 
11,180 

Qls. 
7,499 
5,473 

~     ~ 

6,500 

Qls. 
2,287 

Qls. 
1,100 

Qls. 

837 
900 

Qls. 
51,866 
29,594 
45,709 
29,095 
84,193 
14,000 
62,826 
71,933 
21,277 

251,758 

62,800 

46,410 

34,939 

19,472 

2,287 

1,100 

1,737 

410,493 

SUGAR  OF  LEAD,  properly  jJcetate  of  lead  (Jcetate  de  plomb ;  Sel  de  SatumBf 
Fr. ;  Essigsaures  Bleioxyd,  Bleizucker,  Germ.),  is  prepared  by  dissolving  pure  litharge, 
with  heat,  in  strong  vinegar,  made  of  malt,  wood,  or  wine,  till  the  acid  be  saturated. 
A  copper  boiler,  rendered  negatively  electrical  by  soldering  a  strap  of  lead  within  it,  is 
the  best  adapted  to  this  process  on  the  great  scale,  325  parts  of  finely  ground  and 
sifted  oxyde  of  lead,  require  575  parts  of  strong  acetic  acid,  of  spec.  grav.  7**  Baume, 
for  neutralization,  and  afford  960  parts  of  crystallized  sugar  of  lead.  The  oxyde  should 
be  gradually  sprinkled  into  the  moderately  hot  vinegar,  with  constant  stirring,  to  pre- 
vent adhesion  to  the  bottom ;  and  when  the  proper  quantity  is  dissolved,  the  solution 
may  be  weakened  with  some  of  the  washings  of  a  preceding  process,  to  dilute  the  acetate, 
after  which  the  whole  should  be  heated  to  the  boiling  point,  and  allowed  to  cool  slowly, 
in  order  to  settle.  The  limpid  solution  is  to  be  drawn  off  by  a  syphon,  concentrated 
by  boiling  to  the  density  of  32°  B.,  taking  care  that  there  be  always  a  faint  excess  of 
acid,  to  prevent  the  possibility  of  any  basic  salt  being  formed,  which  would  interfere  with 
the  formation  of  regular  crystals.  Should  the  concentrated  liquor  be  colored,  it  may  be 
whitened  by  filtration  through  granular  bone  black. 

Stoneware  vessels,  with  salt  glaze,  answer  best  for  cry  stall  izers.  Their  edges  should 
be  smeared  with  candle-grease,  to  prevent  the  salt  creeping  over  them  by  efflortscent 
vegetation.  The  crystals  are  to  be  drained,  and  dried  in  a  stove-room  very  slightly 
heated.  It  deserves  remark,  that  linen,  mats,  wood,  and  paper,  imbued  with  sugar  of 
lead,  and  strongly  dried,  readily  take  fire,  and  burn  away  like  tinder.  When  the 
mother  waters  cease  to  aflTord  good  crystals,  they  should  be  decomposed  by  carbonate  of 
«oda,  or  by  lime  skilfully  applied,  when  a  carbonate  or  an  oxyde  will  be  obtained,  fit  for 
treating  with  fresh  vinegar.  The  supernatant  acetate  of  soda  may  be  employed  for  the 
extraction  of  pure  acetic  acid. 

A  main  point  in  the  preparation  of  sugar  of  lead,  is  to  use  a  strong  acid ;  otherwise 
much  time  and  acid  are  wasted  in  concentrating  the  solution.  Tliis  salt  crystallizes  in 
colorless,  transparent,  four  and  six-sided  prisms,  from  a  moderately  concentrated  solution; 
but  from  a  stronger  solution,  in  small  needles,  which  have  a  yellow  cast  if  the  acid  has 
been  slightly  impure.    It  has  no  smell,  a  sweetish  astringent  metallic  taste,  a  specific 


fravity  of  2*345;  it  is  permanent  in  the  air  at  ordinary  temperatures,  but  efl3oresces  when 
heated  to  95®,  with  the  loss  of  its  water  of  crj'stailization  and  some  acid,  falling  into  a 
powder,  which  passes,  in  the  air,  slowly  into  carbonate  of  lead.  The  crystals  dissolve  in 
Ij  times  their  weight  of  water  at  60®,  but  in  much  less  of  boiling  water,  and  in  8  parts  of 
alcohol.  The  solution  feebly  reddens  litmus  paper,  but  has  an  alkaline  reaction  upon  the 
colors  of  violets  and  turmeric.  The  constituents  of  the  salt  are,  58-71  oxyde  of  lea^ 
27'08  acetic  acid,  and  14*21  water,  in  100. 

Acetate  of  lead  is  much  used  in  calico-printing.  It  is  poisonous,  and  ought  to  be  pre- 
pared and  handled  with  attention  to  this  circumstance. 

There  are  two  subacetates  of  lead  ;  the  first  of  which,  the  ter-subacetate,  has  three 
atoms  of  base  to  one  of  acid,  and  is  the  substance  long  known  by  the  name  of  Grouiard's 
extract.  It  may  be  obtained  by  digesting  with  heat  a  solution  of  the  neutral  acetate, 
upon  pure  litharge  or  massicot.  The  solution  affords  white  crystalline  scales,  which  do 
not  taste  so  sweet  as  sugar  of  lead,  dissolve  in  not  less  than  30  parts  of  water,  are  insolu- 
ble in  alcohol,  and  have  a  decided  alkaline  reaction  upon  test  paper.  Carbonic 
acid,  transmitted  through  the  solution,  precipitates  the  excess  of  the  oxyde  of  lead, 
in  the  state  of  a  carbonate,  a  process  long  ago  prescribed  by  Thenard  for  making 
white-lead.  This  subacetate  consists  of  88-66  of  oxyde,  and  13-34  acid,  in  100  parts. 
It  is  employed  for  making  the  orange  sub-chromate  of  lead,  as  also  sometimes  in 
surgery. 

A  sex-subacetatey  containing  6  atoms  of  base,  may  be  obtained  by  adding  ammonia 
in  excess  to  a  solution  of  the  preceding  salt,  and  washing  the  precipitate  with  dilute 
water  of  ammonia.  A  white  powder  is  thus  formed,  that  dissolves  sparingly  in  cold 
water,  but  gives  a  solution  in  boiling  water,  from  which  white  silky  needles  are  de- 
posited.    It  consists  of  92-86  oxyde,  and  7-14  acid. 

SULPHATES,  are  saline  compounds  of  sulphuric  acid  with  oxydized  bases.  The 
ininutest  quantity  of  them  present  in  any  solution,  may  be  detected  by  the  precipitate, 
insoluble  in  nitric  or  muriatic  acid,  which  they  afford  with  nitrate  or  muriate  of  baryta. 
They  are  mostly  insoluble  in  alcohol. 

SULPHATE  OF  ALUMINA  AND  POTASSA,  is  alum. 

SULPHATE  OF  AMMONIA,  is  a  salt  sometimes  formed  by  saturating  the  ammonia 
liquor  of  the  gas-works  with  sulphuric  acid ;  and  it  is  employed  for  making  carbonate  of 
ammonia.     See  Ammonia  and  Sal  Ammoniac 

This  salt,  now  so  extensively  used  in  preparing  artificial  manures  and  imitations  of 
guano,  for  farmers,  is  made  of  great  purity,  and  at  an  economical  rate,  by  the  patent 
process  of  Mr.  Evans,  described  under  the  article  Gas.  A  mixture  of  10  per  cent 
of  this  sulj)hate  with  20  of  bone-dust,  some  gypsum  and  farmyard  manure,  will  form 
a  very  fertilizing  composts  applicable  to  a  great  variety  of  soils. 

SULPHATE  OF  BARYTA,  is  the  mineral  called  heavy-spar,  which  frequently 
forms  the  gangue  or  vein-stone  of  lead  and  other  metallic  oreai 

SULPHATE  OF  COPPER,  Roman  or  Blue  Vitriol  (Vitriol  de  Chypre,  Fr. ;  Kmp~ 
fervitriol,  Germ.),  is  a  salt  composed  of  sulphuric  acid  and  oxyde  of  copper,  and  may  be 
formed  by  boiling  the  concentrated  acid  upon  the  metal,  in  an  iron  pot.     It  is,  how- 
ever, a  natural  product  of  many  copper  mines,  from  which  it  flows  out  in  the  form  of  a 
blue  water,  being  the  result  of  the  infiltration  of  water  over  copper  pyrites,  which  has 
become  oxygenated  by  long  exposure  to  the  air  in  subterranean  excavations.     The  liquid 
is  concentrated  by  heat  in  copper  vessels,  then  set  aside  to  crystallize.     The  salt  forms 
in  oblique  four-sided  tables,  of  a  fine  blue  color;  has  a  spec,  gravity  of  2*104;  an  acerb, 
disagreeable,  metallic  taste ;  and,  when  swallowed,  it  causes  violent  vomiting.    It  be- 
comes of  a  pale  dirty  blue,  and  effloresces  slightly,  on  long  exposure  to  the  air;    when 
moderately  heated,  it  loses  36  per  cent,  of  water,  and  faHs  into  a  white  powder.    It  dis- 
solves in  4  parts  of  water,  at  60°,  and  in  2  of  boiling  water,  but  not  in  alcohol ;  the  solu- 
tion has  an  acid  reaction  upon  litmus  paper.    When  strongly  ignited,  the  acid  flies  off, 
and  the  black  oxyde  of  copper  remains.     The  constituents  of  crystallized  sulphate  of 
copper  are— oxyde,  31-80;    acid,  32*14;   and  water,  36-06.     Its  chief  employment  in 
this  country  is  in  dyeing,  and  for  preparing  certain  green  pigments.    See  Scheele's  and 
ScHWEiNFURTH  Green.     In  Fraucc,  the  farmers  sprinkle  a  weak  solution  of  it  upon 
their  grains  and  seeds  before  sowing  them,  to  prevent  their  being  attacked  by  biids  and 
insects. 

SULPHATE  OF  IRON,  Green  vitriol,  Copperas  {Couperose  verte,  Fr. ;  Eisen-vitriol, 
Schwefelsures  Eisenoxydul,  Germ.),  is  a  crystalline  compound  of  sulphuric  acid  and 
protoxyde  of  iron;  hence  called,  by  chemists,  the  protosulphate ;  consisting  of,  26-10  of 
base,  29*90  of  acid,  and  44*00  of  water,  in  100  parts;  or  of  1  prime  equivalent  of 
protoxyde,  36,  -|-  1  of  acid,  40,  -|-  7  of  water,  63,=  139.  It  may  be  prepared  by  dis- 
solving iron  to  saturation  in  dilute  sulphuric  acid,  evaporating  the  solution  till  a  pel- 
h'cle  forms  upon  its  surface,  and  setting  it  aside  to  crystallize.  The  copperas  of 
eommerce  is  made  m  a  much  cheaper  way,  by  stratifying  the  pyrites  found  in  the  eoal 


788 


SULPHATE  OF  IRON. 


SULPHOSELS. 


789 


iii  i 


I 


ineasiires  (VUridkies  and  SlrahVcies  of  the  Germans),  upon  a  sloping  puddled  platform 
of  stone,  leaving  the  sulphuret  exposed  to  the  weather,  till,  by  the  absorption  of  oxygen, 
il  effloresces,  lixiviating  with  water  the  supersulphate  of  iron  thus  formed,  saturating  thi* 
excess  of  acid  with  plates  of  old  iron,  then  evaporating  and  crystallizing.  The  other 
pyrites,  which  occurs  often  crystallized,  called  by  the  Germans  Schwefelkies  or  EisenkieSf 
must  be  deprived  of  a  part  of  its  sulphur  by  calcination,  before  it  acquires  the  property 
of  absorbing  oxygen  from  the  atmosphere,  and  thereby  passing  from  a  bisulphuret  into 
a  bisulphate.  Alum  schist  very  commonly  contains  vitriolkies,  and  affords,  after  being 
roasted  and  weather-worn,  a  considerable  quantity  of  copperas,  which  must  be  carefully 
•eparated  by  crystallization  from  the  alum. 

This  liquor  used  formerly  to  be  concentrated  directly  in  leaden  vessels;  but  the  first 
stage  of  the  operation  is  now  carried  on  in  stone  canals  of  considerable  length,  vaulted 
over  with  bricks,  into  which  the  liquor  is  admitted,  and  subjected  at  the  surface  to  the 
action  of  flame  and  heated  air,  from  a  furnace  of  the  reverberatory  kind,  constructed  at 
one  end,  and  discharging  its  smoke  by  a  high  chimney  raised  at  the  other.  See  Soda 
Manufacture.  Into  this  oblong  trough,  resting  on  dense  clay,  and  rendered  tight  in 
the  joints  by  water-cement,  old  iron  is  mixed  with  the  liquor,  to  neutralize  the  excess  of 
acid  generated  from  the  pyrites,  as  also  to  correct  the  tendency  to  superoxydizement  in 
copperas,  which  would  injure  the  fine  green  color  of  the  crystals.  After  due  concen- 
tration and  saturation  in  this  surface  evaporator,  the  solution  is  run  off  into  leaden 
boilers,  where  it  is  brought  to  the  proper  density  for  afibrding  regular  crystals,  which  it 
does  by  slow  cooling,  in  stone  cisterns. 

Copperas  forms  sea-green,  transparent,  rhoroboidal  prisms,  which  are  without  smell, 
but  have  an  astringent,  acerb,  inky  taste ;  they  speedily  become  yellowish-brown  in 
the  air,  by  peroxydizement  of  the  iron,  and  effloresce  in  a  warm  atmosphere :  they 
dissolve  in  1'43  parts  of  water  at  60°,  in  0*27  at  190°,  and  in  their  own  water  cf  crystal- 
lization at  a  higher  heat.  This  salt  is  extensively  used  in  dyeing  black,  efei>ecially 
hats,  in  making  ink  and  Prussian  blue,  for  reducing  indigo  in  the  blue  vat,  in  the  China 
blue  dye,  for  making  the  German  oil  of  vitriol,  and  in  many  chemical  and  medicinal 
preparations. 

There  is  a  persulphate  and  subpersulphate  of  iron,  but  they  belong  to  the  domain  of 
chemistry.  The  first  may  be  formed,  either  by  dissolving  with  heat  one  part  of  red 
oxyde  of  iron  (colcothar)  in  one  and  a  half  of  concentrated  sulphuric  acid,  or  by  adding 
some  nitric  acid  to  a  boiling>hot  solution  of  copperas.  It  forms  with  galls  and  logwood 
a  very  black  ink,  which  is  apt  to  become  brown-black.  When  evaporated  to  dryness, 
it  appears  as  a  dirty  white  pulverulent  substance,  which  is  soluble  in  alcohol.  Il  con- 
sists, in  100  parts,  of  39*42  of  red  oxyde  of  iron,  and  60*58  sulphuric  acid. 

Hydrated  peroxyde  of  iron,  prepared  by  precipitation  with  alkali  from  solution  of  the 
persulphate,  is  an  excellent  antidote  against  poisoning  by  arsenic.  A  Trench  perruquier, 
who  had  swallowed  two  drachms  of  arsenious  acid,  was,  after  an  interval  of  twenty  minutes, 
treated  with  the  oxyde  precipitated  from  6  ounces  of  that  salt  by  caustic  potash.  It  was 
diffused  in  20  quarts  of  weak  sirup,  and  administered  in  successive  doses.  After  repeat* 
ed  vomiting  and  purging,  the  patient  felt  no  more  pain,  and  was  pronounced  by  the  phy- 
sician to  be  quite  convalescent. 

In  the  copperas  and  alum  works,  a  very  large  quantity  of  ochrey  sediment  is  obtained; 
which  is  a  peroxyde  of  iron,  containing  a  little  sulphuric  acid  and  alumina.  This  de- 
posite,  calcined  in  reverberatory  hearths,  becomes  of  a  bright-red  color ;  and  when  ground 
and  elutriated,  in  the  same  way  as  is  described  under  uhite  lead,  forms  a  cheap  pigment, 
in  very  considerable  demand,  called  English  red,  in  the  French  market. 

Colcothar  of  Vitriol,  and  Crocus  of  Mars,  are  old  names  for  red  oxyde  of  iron.  Thi» 
brown-red  powder  is  obtained  in  its  purest  state,  by  calcining  dried  sulphate  of  iron  in  a 
furnace  till  all  its  acid  be  expelled,  and  its  base  become  peroxydized.  It  must  be  levi- 
gated, elutriated,  and  dried.  This  powder  is  employed  extensively  in  the  steel  manufac- 
ture, for  giving  the  finishing  lustre  to  fine  articles ;  it  is  used  by  silversmiths  under 
the  name  of  plate  powder  and  rouge ;  and  by  the  opticians  for  polishing  the  specula  of 
reflecting  telescopes.  Much  of  the  crocus  in  the  market,  is  made,  however,  from  the  cop- 
peras and  alum  sediments,  and  is  greatly  inferior  to  the  article  prepared  by  the  last  pro- 
cess. The  finest  rou^z  is  made  by  precipitating  the  oxyde  with  soda,  then  washing  and 
calcining  the  powder. 

An  excellent  powder  for  applying  to  razor-strops,  is  made  by  igniting  together  in  a 
crucible  equal  parts  of  well-dried  copperas  and  sea  salt.  The  heat  must  be  slowly 
raised  and  well  regulated,  otherwise  the  materials  will  boil  over  in  a  pasty  state,  and 
the  product  will  be  in  a  great  measure  lost.  When  well  made,  out  of  contact  of  air, 
it  has  the  brilliant^pect  of  plumbago.  It  has  a  satiny  feel,  and  is  a  true  fer  olegisUf 
similar  in  composition  to  the  Elba  iron  ore.  It  requires  to  be  ground  and  elutriated  { 
after  which  it  afl^ords,  on  drying,  an  impalpable  powder,  that  may  be  either  rubbed 
on  a  strop  of  smooth  bufif  leather,  or  mixed  up  with  hog's-lard  or  tallow  into  a  stifi 
cerate. 


SULPHATE  OF  LIME.    See  Gypsum. 

SULPHATE  OF  MAGNESIA,  Epsom  Salt  (Sel  amer,  Fr. ;  Bittersatz,  Germ.), 
exists  in  sea-water,  as  also  in  the  waters  of  Saidschiitz,  Sedlitz,  and  PiiHna;  and  in  many 
saline  springs,  besides  Epsom  in  Surrey,  whence  it  has  derived  its  trivial  name,  and  from 
which  It  was  first  extracted,  in  the  year  1695,  and  continued  to  be  so,  till  modem  chem- 
istry pointed  out  cheaper  and  more  abundant  sources  of  this  useful  purgative  salt. 
The  sulphate  of  magnesia,  occasionally  found  effloresced  on  the  surface  of  minerals 
in  crystalhne  filaments,  was  called  haarsalz  (hair  salt)  by  the  older  writers.  The  bittern 
of  the  Scotch  sea-salt  works  is  muriate  of  magnesia,  mixed  with  a  little  sulphate  of 
magnesia  and  chloride  of  sodium.  If  the  proper  decomposing  quantity  (found  by  trial) 
of  sulphate  of  soda  be  added  to  it,  and  the  mixed  solution  be  evaporated  at  the  tem- 
perature of  122°  F.,  chloride  of  sodium  will  form  by  double  affinity,  and  fall  down  in 
cubical  crystals;  while  the  solution  of  sulphate  of  magnesia  which  remains,  being 
evaporated  to  the  proper  point,  will  afford  regular  crystals  in  four-sided  prisms  with 
four-sided  acummations.  Or,  if  bittern  be  treated  in  a  retort  with  the  equivalent 
quantity  of  sulphuric  acid,  the  muriatic  acid  may  be  distilled  oflfinto  a  series  of  Woulfe's 
bottles,  and  the,  sulphate  of  magnesia,  soda,  and  lime,  wiU  remain  in  the  retort,  from 
which  mixture  the  sulphate  of  magnesia  may  be  separated  by  filtration  and  crystalliza- 
tion. ^ 

Magnesian  limestone  being  digested  with  as  much  muriatic  acid  as  will  dissolve  out  its 
lime  only,  will,  after  washing,  afl'ord,  with  the  equivalent  quantity  of  sulphuric  acid  a 
pure  sulphate  of  magnesia ;  and  this  is  certainly  the  simplest  and  most  profitable  procesc 
for  manufacturing  this  salt  upon  the  great  scale.  Many  prepare  it  directly,  by  di<»esting 
upon  magnesian  limestone  the  equivalent  saturating  quantity  of  dilute  sulphuric  acid. 
The  sulphate  of  lime  being  separated  by  subsidence,  the  supernatant  solution  of  sulphate 
of  magnesia  is  evaporated  and  crystallized. 

This  salt  is  composed  of,  magnesia  16*72,  sulphuric  acid  32*39,  and  water  50-89 
When  free  from  muriate,  it  tends  to  effloresce  in  the  air.    It  dissolves  in  four  parts  of 
water  at  32°,  in  3  parts  at  60°,  in  1*4  at  200°,  and  in  its  own  water  of  crystallization  at 
a  higher  heat. 

SULPHATE  OF  MANGANESE  is  prepared  on  the  great  scale  for  the  calico- 
pnnters,  by  exposing  the  peroxyde  of  the  metal  and  pitcoal  ground  together,  and  made 
into  a  paste  with  sulphuric  acid  to  a  heat  of  400°  F.  On  lixiviating  the  calcined  mass, 
a  solution  of  the  salt  is  obtained,  which  is  to  be  evaporated  and  crystallized.  It  forms 
pale  amethyst-colored  prisms,  which  have  an  astringent  bitter  taste,  dissolve  in  2i  parU 

So  o^^^"*'  ^^^  ^^^^^^^  ®^'  protoxyde  of  manganese  31*93,  sulphuric  acid  35*87,  and  water 
32*20,  m  100  parts.  ' 

SULPHATE  OF  MERCURY  is  a  white  salt  which  is  used  in  making  corrosive 
sublimate.     See  Mercury.     The  subsulphate,  called  Turbith  Mineral,  is  a  pale  yeUow 
pigment,  and  may  be  prepared  by  washing  the  white  sulphated  peroxyde  with  hot  water 
which  resolves  It  into  the  soluble  supersulphate,  and  the  insoluble  subsulphate,  or  Turirith 
It  IS  poisonous.  ' 

SULPHATE  OF  POTASSA  is  obtained  by  first  igniting  and  then  crystalUzing  the 
residuum  of  the  distillation  of  nitric  acid  from  nitre. 

SULPHATE  OF  SODA  is  commonly  called  Glauber's  salt,  from  the  name  of  the 
chemist  who  first  prepared  it.  It  is  obtained  by  igniting  and  then  crystallizing  the  resi- 
duum of  the  distillation  of  muriatic  acid  from  common  salt.  It  crystallizes  in  channeUed 
6-sided  prisms.     See  Soda  Manufacture. 

SULPHATE  OF  ZINC,  called  also    White  Vitriol,  is  commonly  prepared  in  the 
Harz,  by  washmg  the  ca  cmed  and  effloresced  sulphuret  of  zinc  or  blende,  on  the  same 
principle  as  green  and  blue  vitriol  are  obtained  from  the  sulphurets  of  iroi  and  coddct 
Pure  sulphate  of  zmc  may  be  made  most  readily  by  dissolving  the  metal  in  dilute  sulphni 
nc  acid,  evaporating  and  crystallizing  the  solution.     It  forms  prismatic  crystals  which 

SULPHITES  are  a  class  of  salts,  consisting  of  sulphurous  acid,  combined  in  eauivalent 
proportions  with  the  oxydized  bases.  a  f  »  «t,iu,  comoinea  in  equivalent 

SULPHOSELS  is  the  name  given  by  Berzelius  to  a  class  of  salts  which  mar  be 
rrverv'S'n^:;!-.  ^T^^/  «*»'  P-^^i^^ing  of  an  oxydT and  an  LIJ  (an  o^Lo 
S.„r.tp7hvTniprrn  V^  ''^^?'''  *"^,  ^T^  ^*^^«»g^  t»»«  solution  a  stream  3^  sail 
phureted  hydrogen,  till  the  sa  t  be  entirely  decomposed.     In  this  operation,  the  oxysaU 

firtlTlr.K  ^'^^^^*«^^*>y  the  sulphur  of  the  compound  gas ;  while  its  hydSg^ 
forms  water  with  the  oxygen  of  the  saline  base.    This  process  is  applicable  only  to  the 

Xr  'LfhS'nrV""'-^  these  not  to  the  nitrates,  carbonates,  or  phosphates.     2.  Tn. 
other  method  of  preparing  sulphxtsalts  is,  to  add  to  a  watery  solution  of  sulphuret  of 


790 


SULPHUR. 


potassium,  an  electro-negative  metallic  sulphuret,  which  will  dissolve  in  the  liquid  tii 
the  sulphuret  of  potassium  be  saturated.  This  saline  compound  is  to  be  employed 
to  effect  double  decompositions  with  the  oxysalts ;  that  is,  to  convert  the  radical  of 
another  b«se,  combined  with  an  oxacid^  into  a  sulphosalt.  3.  If  the  electro-negative 
sulphuret  be  put  in  powder  into  a  solution  of  the  hydrosulphuret  of  potassa,  it  will  dis- 
solve and  expel  the  sulphureted  hydrogen  with  effervescence :  just  as  carbonic  acid  is 
displaced  by  a  stronger  acid.  For  his  other  three  methods  of  preparing  sulphosalts,  see 
his  ElementSy  vol.  iii.  p.  336,  Fr.  translation. 

SULPHUR,  Brimstone  (Sou/re,  Fr. ;  Sckwe/el,  Germ.),  is  a  simple  combustible,  solid, 
non-metallic,  of  a  peculiar  yellow  color,  very  brittle,  melting  at  the  temperature  of  226* 
Fahr.,  and  possessing,  after  it  has  been  fused,  a  specific  gravity  of  1'99.  M'hen  held  in 
a  warm  hand,  a  roll  of  sulphur  emits  a  crackling  sound,  by  the  fracture  of  its  interior 
parts;  and  when  it  is  rubbed,  it  emits  a  peculiar  well-known  smell,  and  acquires  vt  the 
same  time  negative  electricity.  When  heated  to  the  temperature  of  660°  F.  it  takes  fire, 
burns  away  with  a  dull  blue  flame  of  a  suffocating  odor,  and  leaves  no  residuum.  When 
naore  strongly  heated,  sulphur  burns  with  a  vivid  white  flame.  It  is  not  afl'ected  by  air 
T  water. 

Sulphur  is  an  abundant  product  of  nature ;  existing  sometimes  pure  or  merely  mixed, 
and  at  others  in  intimate  chemical  combination  with  oxygen,  and  various  metals,  form- 
ing sulphates  and  sulphurets.  See  ores  of  Copper,  Iron,  Lead,  &c.,  under  these 
metals. 

Fig.  1417  represents  one  of  the  cast-iron  retorts  used  at  Marseilles  for  refining  sul- 
phur, wherein  it  is  melted  and  converted  into  vapors,  which  are  led  into  a  large 
chamber  for  condensation.  The  body  a,  of  the  retort  is  an  iron  pot,  3  feet  in  diameter 
outside,  22  inches  deep,  half  an  inch  thick,  which  weighs  14  cwts.,  and  receives  a  charge 
of  8  cwts.  of  crude  sulphur.  The  grate  is  8  inches  under  its  bottom,  whence  the  flame 
rises  and  plays  round  its  sides.  A  cast-iron  capital  b,  being  luted  to  the  pot,  and 
coverei'wiih  sand,  the  opening  in  front  is  shut  with  an  iron  plate.  The  chamber  d,  is 
23  feet  long,  11  feet  wide,  and   13  feet  high,  with   walls  32  inches  thick.     In  the  roof, 

at  each  gable,  valves  or  flap- 
doors,  e,  10  inches  square,  are 
placed  at  the  bottom  of  the 
chimney  c.  The  cords  for  open- 
ing the  valves  are  led  down  to 
the  side  of  the  furnace.  The 
entrance  to  the  chamber  is  shut 
with  an  iron  door.  In  the  wall 
opposite  to  the  retorts,  there  are 
two  apertures  near  the  floor,  for 
taking  out  the  sulphur.  Each 
of  the  two  retorts  belonging  to 
a  chamber  is  charged  with  7^  or 
8  cwts.  of  sulphur ;  but  one  is 
fired  first,  and  with  a  gentle 
heat,  lest  the  brimstone  froth 
should  overflow;  but  when  the 
fumes  begin  to  rise  copiously, 
with  a  stronger  flame.  The  dis- 
tillation commences  within  an 
hour  of  kindling  the  fire,  and  is 
eompleted  in  six  hours.  Three  hours  after  putting  fire  to  the  first  retort,  the  second  is 
in  like  manner  set  in  operation. 

When  the  process  of  distillation  is  resumed,  after  having  been  some  time  suspended, 
explosions  may  be  apprehended,  from  the  presence  of  atmospherical  air ;  to  obviate  the 
danger  of  which,  the  flap-doors  must  be  opened  every  ten  minutes;  but  they  should 
remain  closed  during  the  setting  of  the  retorts,  and  the  reflux  of  sulphurous  fumes  or 
acid  should  be  carried  off  by  a  draught-hood  over  the  retorts.  The  distillation  is  carried 
on  without  interruption  daring  the  week,  the  charges  being  repeated  four  times  in  the 
day.  By  the  third  day,  the  chamber  acquires  such  a  degree  of  heat  as  to  preserve  the 
sulphur  in  a  liquid  state;  on  the  sixth,  its  temperature  becoming  nearly  300°  F.,  gives 
the  sulphur  a  dark  hue,  on  which  account  the  furnace  is  allowed  to  cool  on  the  Sunday. 
The  fittest  distilling  temperature  is  about  248°.  The  sulphur  is  drawn  off  through  two 
iron  pipes  cast  in  the  iron  doors  of  the  orifices  on  the  side  of  the  chamber  opposite  to  the 
furnace.  The  iron  stoppers  being  taken  out  of  the  mouths  of  the  pipes,  the  sulphur  is 
allowed  to  run  along  an  iron  spout  placed  over  red-hot  charcoal,  into  the  appropriate 
wooden  moulds. 

Native  stUphnr  in  its  pure  state  is  solid,  brittle,  transparent,  yellow,  or  yellow  bordei>^ 


SULPHUR. 


791 


inf  on  green,  and  of  a  glassy  lustre  when  newly  broken.  It  occurs  frequently  in  crys- 
talline masses,  and  sometimes  in  complete  and  regular  crystals,  which  are  all  derivaWe 
'  from  the  rhomboidai  octahedron.  The  fracture  is  usually  conchoidal  and  shining.  Its 
specific  gravity  is  2*072,  exceeding  somewhat  the  density  of  melted  sulphur.  It  possesses 
a  very  considerable  refractive  power ;  and  doubles  the  images  of  objects  even  across  two 
parallel  faces.  Sulphur,  crystallized  by  artificial  means,  presents  a  very  remarkable  phe- 
nomenon; for  by  varying  the  processes,  crystals  are  obtained  whose  forms  belong  to  two 
different  systems  of  crystallization.  The  red  tint,  so  common  in  the  crystals  of  Sicily, 
and  of  volcanic  districts,  has  been  ascribed  by  some  mineralogists  to  the  presence  of  real- 
g€U",  and  by  others  to  iron;  but  Stromeyer  has  found  the  sublimed  orange-red  sulphur  of 
Vulcano,  one  of  the  Lipari  islands,  to  result  from  a  natural  combination  of  sulphur  and 
selenium. 

It  is  extracted  from  the  minerals  containing  it,  at  Solfatara,  by  the  following  pro 
cess: — 

Ten  earthen  pots,  of  about  a  yard  in  height,  and  four  and  a  half  gallons  imperial  in  o» 
pacity,  bulging  in  the  middle,  are  ranged  in  a  furnace  called  a  gallery;  five  being  set  on  th^ 
one  side,  and  five  on  the  other.  These  are  so  distributed  in  the  body  of  the  walls  of  thj 
gallery,  that  their  belly  projects  partly  without,  and  partly  within,  while  their  top  riset 
out  of  the  vault  of  the  roof.  The  pots  are  filled  with  lumps  of  the  sulphur  ore  of  the  size 
of  the  fist;  their  tops  are  closed  with  earthenware  lids,  and  from  their  shoulder  proceeds 
a  pipe  of  about  two  inches  diameter,  which  bends  down,  and  enters  into  another  covered 
pot,  with  a  hole  in  its  bottom,  standing  over  a  tub  filled  with  water.  On  applying  heat 
to  the  gallery,  the  sulphur  melts,  volatilizes,  and  runs  down  in  a  liquid  state  into  the  tubs, 
where  it  congeals.  When  one  operation  is  finished,  the  pots  are  re-charged,  and  the  pro- 
cess is  repeated. 

In  Saxony  and  Bohemia,  the  sulphurets  of  iron  and  copper  are  introduced  into  lai^e 
earthenware  pipes,  which  traverse  a  furnace-gallery ;  and  the  sulphur  exhaled  flows  into 
pipes  filled  with  cold  water,  on  the  outside  of  the  furnace.     900  parts  of  sulphuret  afford 
from  100  to  150  of  sulphur,  and  a  residuum  of  metallic  protosulphuret.     See  METAJXua 
ov  and  Copper. 

Volcanic  sulphur  is  purer  than  that  extracted  from  pyrites ;  and  as  the  latter  is  com- 
monly mixed  with  arsenic,  and  some  other  metallic  impregnations,  sulphuric  acid  made 
of  it  would  not  answer  for  many  purposes  of  the  arts;  though  a  tolerably  good  sulphuric 
acid  may  be  made  directly  from  the  combustion  of  pyrites,  instead  of  sul[«/iur,  in  the  lead 
chambers.  The  present  high  price  of  the  Sicilian  sulphur  is  a  great  encouragement  to 
its  extraction  from  pyrites.  It  is  said  that  the  common  English  brimstone,  such  as  was 
extracted  from  the  copper  pyrites  of  the  Parys  mine  of  Anglesey,  contained  fully  a  fif- 
teenth of  residuum,  insoluble  in  boiling  oil  of  turpentine,  which  was  chiefly  orpiment ; 
while  the  fine  Sicilian  sulphur,  now  imported  in  vast  quantities  by  the  manufacturers  of 
oil  of  vitriol,  contains  not  more  than  three  per  cent,  of  foreign  matter,  chiefly  earthy,  but 
not  at  all  arsenical. 

Sulphur  has  been  known  from  the  most  remote  antiquity.  From  its  kindling  at  a  mo- 
derate temperature,  it  is  employed  for  readily  procuring  fire,  and  lighting  by  its  flame 
other  bodies  not  so  combustible.  At  Paris,  the  preparation  of  sulphur  matches  constitutes 
a  considerable  branch  of  industry.  The  sulphurous  acid  formed  by  the  combustion  of 
sulphur  in  the  atmospheric  air,  is  employed  to  bleach  woollen  and  silken  goods,  as  also 
cotton  stockings;  to  disinfect  vitiated  air,  though  it  is  inferior  in  power  to  nitric  acid 
vapor  and  chlorine ;  to  kill  mites,  moths,  and  other  destructive  insects  in  collections  of 
zoology ;  and  to  counteract  too  rapid  fermentation  in  wine-vats,  &.c.  As  the  same  acid 
gas  has  the  property  of  suddenly  extinguishing  flame,  sulphur  has  been  thrown  into  a 
chimney  on  fire,  with  the  best  effect;  a  handful  /  •*»  being  sometimes  suflUcient.  Sulphur 
is  also  employed  for  cementing  iron  bars  in  stone-,  for  taking  impressions  from  seals  and 
cameos,  for  which  purpose  it  is  kept  previously  melted  for  some  time,  to  give  the  casts  an 
appearance  of  bronze.  Its  principal  uses,  however,  are  for  the  manufactures  of  vermil- 
ion, or  cinnabar,  gunpowder,  and  sulphuric  acid. 

See  Metallurgy,  page  157,  for  the  description  of  Gahn's  furnace  for  extracting  sul- 
phur  from  pyrites. 

Pyrites  as  a  bi-sulphuret,  consisting  of  45*5  parts  of  iron,  and  54*5  of  sulphur,  may,  by 
proper  chemical  means,  be  made  to  give  oft"  one  half  of  its  sulphur,  or  about  27  per  cent,  j 
but  great  care  must  be  taken  not  to  generate  sulphurous  acid,  as  is  done  very  wastefulljr 
by  the  Fahlun  and  the  Groslar  processes.  By  the  latter,  indeed,  not  more  than  one  or  two 
parts  of  sulphur  are  obtained,  by  roasting  100  part:  of  the  pyritous  ores  of  the  Rammels- 
berg  mines.  In  these  cases,  the  sulphur  is  burned,  instead  of  being  sublimed.  The  re- 
siduum of  the  operation,  when  it  is  well  conducted,  is  black  sulphuret  of  iron,  which  may 
be  profitably  employed  for  making  copperas.  The  apparatus  for  extracting  sulphur  from 
pyrites  should  admit  no  more  air  than  is  barely  necessary  to  promote  the  sublimation. 
Sicily  produced  last  year  70,000  tons  of  sulphur,  and  Tuscany  1200;  of  which  Great  BriU 


788 


SULPHURIC  ACID 


I  i  ■  ( 


I 


^rnXnlTsVooTon;/""'''  ''''^'  other  places,  6,000.    In  1820,  Great  irJtafn  «» 
SULPHURATION,  is  the  process  by  which  woollen,  silk,  and  cotton  eoods  are  ex, 
posed  to  the  vapors  of  burning  sulphur,  or  to  sulphurous  acid  gas     InTe  aS  Straw 
ot^r^"^""""'  '  '"'  '"'"'''  '  '^"^^^  ''''  ^^^^P  api^atu^  well  Spt^^^^^^^^ 
Sulphuring-rooms  are  sometimes  constructed  upon  a  great  scale,  in  which  blankets. 

stdd\:fla.":S"wrth'^''l""^^  '^  ^"^P^'^^^'  ^^^^^y"P«"  poles  ;,rco^sTK^^^ 
should  be  flagged  with  a  sloping  pavement,  to  favor  the  drainage  of  the  water  that  drops 

down  from  the  moistened  cloth.  The  iron  or  stoneware  vessels,  in  which  the  sutphur  ^ 
cordit'to  thfH*"  the  corners  of  the  apartment.  They  should  be  increased  n  number  a" 
cord  ng  to  he  dimensions  of  the  place,  and  distributed  uniformly  over  it.  The  windo^ 
dZ-  thPr?  Jif  "Ti  i^""  """'n^^  ""^^^  *°  '^"^  hermetically  close.  In  the  lower  part  of  the 
e^  iv  th.l..h  •  ^  T"  ^P^"'"-.^'th  a  sliding  shutter,  which  may  be  raised  or  low- 
ered  by  the  mechanism  of  a  cord  passing  over  a  pulley. 

iJrv^on^.h?r  K^  "^r"'^  ?'  sulphurous  acid  and  azotic  gases  are  let  off,  in  order  to 
W^.hL  *^«"^"sl»«n.  should  be  somewhat  larger  than  the  opening  at  the  bottom.  A 
InaL  I  W  ^  '^'■"^'  the  noxious  gases  above  the  building,  and  diffuses  them  over  a  widi 
TathlnZ  T^"''^"  ^5;"|  promoted  by  means  of  a  draught-pipe  of  iron,- connected  with 
an  ordinary  stove,  provided  with  a  valve  to  close  its  orifice  when  not  kindled. 

nans  ,t  U  kin^^^^^^^^  J  proper  quantity  of  sulphur  being  next  put  into  the  shallow 
lllr  thV  c  !  '•  ^  ^""^T^^  1''°'' ''  '^^'"^'  «^  ^^"  ««  its  shutter,  while  a  vent-hole 
f!^l-  F  i  '^  T"^  ^^  drawing  its  cord,  which  passes  over  a  pulley.  After  a 
few  minutes,  when  the  sulphur  is  fully  kindled,  that  vent-hole  must  be  almost  entirely 
^t,  by  relaxing  the  cord  ;  when  the  whole  apparatus  is  to  be  let  alone  for  a  sufficient 

fr«I!*fho^^r*  K^  ^^v  P*':'*'^^'"^  precautions  is  to  prevent  the  sulphurous  acid  gas  escaping 
from  the  chamber  by  the  seams  of  the  principal  doorway.  Tnis  is  secured  by  closing  i1 
imperfectly,  so  that  it  may  admit  of  the  passage  of  somewhat  more  air  than  can  enter  by 
Uie  upper  seanjs,  and  the  smallest  quantity  of  fresh  air  that  can  support  the  combustion. 

t.nf  Zr  ^  ^i?n  *^  T'""^";  °^  ^''  "^y  ^^  increased  at  pleasure,  by  enlarging  the  under 

vent-hole  a  httle,  and  quickening  the  fire  of  the  drauffht-stove. 

«m«»  fil^'^^^JI^  the  entrance  door  of  the  apartment,  for  the  discharge  of  the  goods,  a 

o^r  f  n^  r  1^^-  ^'^K^^  '"  'i^  ^""^"-^^  ^"""«^^'  *^^  vent-hole  must  be  thrown  entirely 
open  and  the  sliding  shutter  of  the  door  must  be  slid  up,  gradually  more  and  more  every 

2?Thf  f  T  ^'""•V,  ?"^  ^"^"y  ^'^  "^'"^^  ^P^»  ^^^  *  P^«P«^  time.  By  this  me^s  the  a^ 
of  the  chamber  will  become  soon  respirable. 

.  jy^^f^?^TF  HYDROGEN,  is  a  gas,  composed  of  one  part  of  hydrogen  and  six- 
teen  parts  of  sulphur,  by  weight.  Its  specific  gravity  is  M912,  compared  to  air=l-0O0O. 
It  is  the  active  constituent  of  the  sulphurous  mineral  waters.  When  breathed,  it  is  very 
deleterious  to  animal  life ;  and  being  nearly  twice  as  dense  as  air,  it  may  be  poured  from 
us  generating  bottle  into  cavities;  a  scheme  successfully  employed  by  M.  Thenard  to  de- 
stroy rats  m  their  holes. 

SULPHURIC  ACID,  Vitriolic  ^cid,  or  Oil  of  Vitriol,  (^cide  sul/urique,  Fr. ; 
HnnT"^  T'  ^T*^  ^^'f  important  product,  the  agent  of  many  chemical  operal 
tions,  was  formerly  procured  by  the  distillation  of  dried  sulphate  of  iron,  called  green 
Jlni  •  "^f  "^«.  the  corrosive  liquid  which  came  over,  having  an  oily  consistence,  was 
denominated  oil  of  vitriol.  This  method  has  been  superseded  in  Great  Britain,  France! 
and  most  other  countries,  by  the  cox;.-,L-tion  o^  sulphur  along  with  nitre,  in  large 

InH  M««!r  ""^ '  •  ^"o  *^  ^^  ^°''"'^'"  P''^*'^^s>  ^h^'^"  's  still  practised  at  Bleyl  in  Bohemia, 
Md  Nordhausen  m  Saxony,  gives  birth  to  some  interesting  results,  I  shall  describe  it 

Into  a  long  horizontal  furnace,  or  gallery  of  brickwork,  a  series  of  earthenware  retorts. 
01  a  pear  shape,  is  arranged,  with  curved  necks  fitted  into  stoneware  bottles  or  conden- 
J!^*^»  ,  ""^  ""^  *^  ^J}^^^^  "^ith  sulphate  of  iron,  which  has  been  previously  heated 
to  mo-Jerate  redness.  The  first  product  of  the  distillation,  a  slightly  acidulous  phlegm,  is 
allowed  to  escape  ;  then  the  retort  and  receiver  are  securely  luted  together.  The  fire  is 
•^LfL''^\l  /""^^"^r 5"'^^^  ^°':  ^^^'^y-^'*  ^°""s,  whereby  the  strong  sulphuric  acid  is 
expelled,  w  the  form  of  heavy  white  vapors,  which  condense  in  the  cold  receiver  into  an 
oily-looking  liquid.  The  latter  portions,  when  received  in  a  separate  refrigerator,  fre- 
quently concrete  into  a  crystalline  mass,  formerly  called  glacial  oil  of  vitriol.  About  six. 
ty  four  pounds  of  strong  acid  may  be  obtained  from  six  hundred  pounds  of  copperas.  It 
18  brown-colored ;  and  varies  in  specific  gravity  from  1-842  to  1-896.  Its  boiling  point 
18  so  low  as  120°  Fahr.  When  re-distilled  in  a  glass  retort,  into  a  receiver  surrounded 
with  ice,  a  very  moderate  heat  sends  over  white  fumes,  which  condense  into  a  soft  solid. 
IB  silky  filaments,  like  asbestos,  tough,  and  difficult  fo  cut.    When  this  is  exposed  tf 


SULPHURIC  ACID. 


793 


the  air,  it  emits  copious  fumes  of  sulphuric  (not  sulphurous)  acid.  It  bums  holes  m 
paper  as  rapidly  as  a  red-hot  iron.  Dropped  in  small  quantities  into  water,  it  excites  a 
hissing  noise,  like  ignited  metal ;  and  in  larger  quantities,  it  occasions  an  explosion. 
By  dropping  a  fragment  of  it  into  a  poised  vial  containing  water,  and  stoppering  in- 
stantly, to  prevent  the  ejection  of  liquid,  by  the  ebullition  which  always  ensues,  I  got  a 
dilute  acid,  containing  a  known  portion  of  the  solid  acid,  from  the  specific  gravity  of 
which,  as  well  as  from  its  saturating  power,  I  ascertained  that  the  above  solid  sulphuric 
acid  was  truly  anhydrous  (void  of  water),  consisting  of  1  equivalent  proportion  of  sul- 
phur, and  3  of  oxygen  ;  or,  by  weight,  of  16  of  the  A)rmer,  and  24  of  the  latter.  Thit 
acid  makes  a  red  solution  of  indigo. 

The  production  of  sulphuric  acid  from  sulphur  and  nitre  may  be  elegantly  illustrated 
by  means  of  a  glass  globe  with  a  stoppered  hole  at  its  side,  and  four  bent  glass  tubes  in- 
sened  into  a  leaden  cap  in  its  upper  orifice.  The  first  tube  is  to  be  connected  with  a 
heated  matrass,  disengaging  sulphurous  acid  from  copper  filings  and  sulphuric  acid ;  the 
second  with  a  retort,  disensraging  more  slowly  deutoxyde  of  azote  (nitric  oxyde)  from 
copper  filings  and  nitric  acid  ;  the  third  with  a  vessel  for  furnishing  steam  in  a  moderate 
current  towards  the  end  of  the  process,  when  no  water  has  been  previously  admitted  into 
the  balloon  ;  the  fourth  tube  may  be  upright,  and  terminate  in  a  small  funnel.  Through 
the  opening  in  the  side  of  the  globe,  atmospherical  air  is  to  be  admitted  from  lime  tc  ♦kne, 
by  removing  the  stopper ;  after  which,  the  residuary  lighter  azote  may  be  allowed  to 
escape  by  the  funnel  orifice. 

The  nitric  oxyde  first  absorbs  oxygen  from  the  air,  becomes,  in  consequence,  nitrous 
acid  vapor,  which  giving  up  one  third  of  its  oxygen  to  the  sulphurous  acid,  converts  this, 
with  the  aid  of  water,  into  sulphuric  acid,  while  itself  returning  to  the  slate  of  nitric 
oxyde,  is  again  qualified  to  take  oxygen  from  the  air,  and  to  transfer  it  to  the  sulpharous 
acid  gas;  and  thus  in  perpetual  rotation.  These  oxygenating  and  disoxygenating  pro- 
cesses continue  until  nearly  the  whole  oxygen  of  the  atmospheric  air  contained  in  the 
globe  is  consumed.  Were  there  liitle  aqueous  vapor  present,  those  gases  would  soon 
cease  to  operate  upon  each  other ;  for  though  the  nitric  oxyde  became^  nitrous  acid,  this 
would  oxygenate  little  of  the  sulphurous  acid,  because  the  three  substances  would  con- 
dense into  white  crystals  upon  the  sides  of  the  balloon,  like  hoar  frost  upon  a  window- 
pane  in  winter.  These  indicate  a  deficiency  of  aqueous  vapor,  and  an  excess  of  nitrous 
acid.  On  the  admission  of  steam,  the  crystals  disappear,  the  sulphuric  acid  is  liquefied, 
the  nitrous  acid  is  converted  into  nitric  acid  and  nitric  oxyde ;  the  former  of  which  com- 
bines with  the  water,  while  the  latter  is  converted  by  the  atmospheric  oxygen  into  nitrous 
acid  vapor.  A  certain  quantity  of  water  is  therefore  requisite  to  prevent  the  formation 
of  that  crystalline  compound,  which  condenses  the  nitrous  acid,  and  renders  it  inoperative 
in  transforming  fresh  portions  of  sulphurous  acid  into  sulphuric.  On  these  principles 
alone  is  it  possible  to  oxygenate  the  sulphurous  acid,  by  the  nitrous  acid  resuming  and 
surrendering  a  dose  of  oxygen.  In  perpetual  alternation. 

It  was  MM.  Clement  and  Desormes  who  first  had  the  sagacity  to  trace  these  compli- 
cated  changes.  They  showed  that  nitrous  acid  gas  and  sulphurous  acid  gas  mixed,  react 
on  each  other  through  the  intervention  of  moisture  ;  that  there  resulted  thence  a  combina- 
tion of  sulphuric  acid,  deutoxyde  of  azote  (nitrous  gas),  and  water;  that  this  crystalline 
Compound  was  instantly  destroyed  by  more  water,  with  the  separation  of  the  sulphuric  acid 
in  a  liquid  state,  and  the  disengagement  of  nitrous  gas;  that  this  gas  re-constituted  nitrous 
acid  at  the  expense  of  the  atmospheric  oxygen  of  the  leaden  chamber,  and  thus  brought 
matters  to  their  primary  condition.  From  this  point,  starting  again,  the  particles  of 
sulphur  in  the  sulphurous  acid,  through  the  agency  of  water,  became  fully  oxygenated  by 
the  nitrous  acid,  and  fell  down  in  heavy  drops  of  sulphuric  acid,  while  the  nitrous  gas 
derived  from  the  nitrous  acid,  had  again  recourse  to  the  air  for  its  lost  dose  of  oxygen. 
This  beautiful  interchange  of  the  oxygenous  principle  was  found  to  eo  on,  in  their  ex- 
periments, till  either  the  sulphurous  acid,  or  oxygen  in  the  air,  was  exhausted. 

They  verified  this  proposition,  with  regard  to  what  occurs  in  sulphuric  acid  chambers, 
by  mixing  m  a  crystal  globe  the  three  substances,  deutoxyde  of  azote,  sulphurous  acid, 
and  atmospheric  air.     The  immediate  production  of  red  vapors  indicated  the  transforma- 
tion of  the  deutoxyde  into  nitrous  acid  gas;    and  now  the  introduction  of  a  very  little 
water  caused  the  proper  reaction,  for  opaque  vapors  rose,  which  deposited  white  star- 
form  cr>'slals  on  the  surface  of  the  glass.     The  gases  were  once  more  transparent  and  color- 
less; but  another  addition  of  water  melted  these  crystals  with  effervescence,  when  ruddy 
rapors  appeared.    In  this  manner  the  phenomena  were  made  to  alternate,  till  the  oxygen 
ofthe  included  air  was  expended,  or  all  the  sulphurous  acid  was  converted  into  sul- 
phuric.   The  residuaiy  gases  were  found  to  be  nitrous  acid  gas  and  azote,  without  sul- 
phurous acid  gis ;  while  unctuous  sulphuric  acid  bedewed  the  inner  surface  ofthe  globe. 
Hence,  Ihey  justly  concluded  their  new  theory  of  the  manufacture  of  oil  of  vitriol  to  be 
demonstrated. 

In  consequence  of  their  discovery,  the  manufacture  of  this  acid  has  received  suck 


794 


SULPHURIC  ACID. 


improvements,  that  a  nearly  double  product  of  it  may  now  be  obtained  from  the  same 
weight  of  materials.  Indeed,  the  economy  may  be  reckoned  to  be  much  greater;  for  one 
half  of  the  more  cosily  ingredient,  the  nitre,  formerly  employed  with  a  given  weight  of 
•alphur,  suffices  at  present. 

^  In  the  manufacture  of  sulphuric  acid  upon  the  great  scale,  two  different  systems  of 
working  were  long  prevalent ;  the  intermittent  or  periodical,  and  the  continuous  or 
uniform.  Both  were  carried  on  in  large  leaden  chambers.  In  the  former,  the  cham- 
bers were  closed  during  the  period  of  combustion  and  gaseous  combination,  but  were 
opened  from  lime  to  time  to  introduce  fresh  atmospheric  air.  This  method  is,  I  believe, 
generally  abandoned  now,  on  account  of  the  difficulties  and  delays  attending  it,  though 
it  afforded  large  products  in  skilful  hands.  In  the  latter,  a  continuous  current  of  air  is 
allowed  to  enter  at  the  oven  in  front  of  the  chamber  for  the  combustion  of  the  sulphur, 
and  there  is  a  constant  escape  of  nitrogen  gas,  with  a  little  sulphurous  acid  gas,  at  the 
remote  end  of  the  roof. 

Fig.  1418  represents  a  sulphuric  acid  chamber,  a,  a,  are  the  bi  ick  or  j^one  pillars  upon 
which  it  rests ;  fr,  6,  are  the  sustaining  wooden  beams  or  joists  ;  c,  is  the  chimney  for  the 
discharge  of  the  nitrogen ;  rf,  is  the  roof,  and  c,  the  sole  of  the  hearth  for  the  combustion 
of  the  sulphur;  /,  is  the  cylindrical  tunnel,  or  pipe  of  lead  or  cast  iron,  for  conducting 
the  gasiform  materials  into  the  chamber ;  g,  is  the  steam  boiler ;  and  hy  the  steam-pipe. 
That  plan  is  variously  modified,  by  different  oil  of  vitriol  makers  in  this  country  and 
in  France.  Very  frequently,  the  oven  e,  d,  is  not  situated  under  the  chamber,  but 
is  built  at  the  end  of  it,  as  at  t,  and  arched  over  with  brick,  the  crown  being  9 
inches  thick.  The  pipe/,  18  inches  in  diameter,  is  then  placed  outside  of  the  chamber, 
being  inserted  into  a  brick  chimney,  and,  turning  rectangularly,  enters  it  opposite  k. 
The  sole  of  the  hearth  e,  is  a  thick  plate  of  cast  iron  (not  hollowed  as  shown  in  the 
figure),  5  or  6  feet  long,  and  3  or  4  broad,  with  a  small  fireplace  constructed  beneath 
it,  whose  smoke-flue  runs  outwards,  under  the  floor,  to  the  side  wall  of  the  building. 
The  oven  is  in  this  case  about  2  feet  in  height,  from  the  sole  to  the  roof;  and  it  hat 
an  iron  door,  about  12  inches  by  15,  which  slides  up  and  down  in  a  tightly-fitted  iron 

frame.  This 
door  is  frequent- 
ly placed  in  the 
side  of  the  oven, 
parallel  to  the 
long  side  of  the 
leaden  chamber. 
A  stout  collar 
of  lead  is  bolted 
to  the  chamber, 
where  the  pipe 
enters  it.  A 
the  middle  of 
the  side  of  the 
chamber,  about 
2  feet  above  the 
ground,  a  leaden 
trough  is  fixed, 
which  serves  as 
a  syphon-funnel  and  water-trap  for  introducing  water  to  the  acid  gases. 

Several  manufacturers  divide  the  chamber  into  a  series  of  rectangular  compartments, 
by  parallel  leaden  screens,  10  or  12  feet  asunder,  and  allow  these  compartments  to  com- 
municate by  a  narrow  opening,  or  a  hole  1  foot  square,  in  the  top  and  bottom  of  each 
screen  alternately.  Thus  the  fumes,  which  enter  from  the  chimney-pipe  over  A:,  will  be 
forced,  by  the  screen  at  6,  to  descend  to  1,  and  pass  through  the  opening  there,  to  get  into 
the  second  compartment,  whence  Ihey  will  escape  near  the  top  at  2,  thus  circulating  up 
and  down,  so  as  to  occasion  a  complete  agitation  and  intermixture  of  their  hetero- 
geneous particles.  Into  the  side  of  the  chamber,  opposite  to  the  centre  of  each  com- 
partment, a  lead  pipe  enters,  and  proceeds  towards  the  middle  of  the  area,  terminating  in 
a  narrow  orifice,  for  discharging  a  jet  of  high-pressure  steam  from  a  boiler  loaded  with 
40  pounds  upon  the  square  inch.  This  boiler  should  be  placed  under  a  shed  exterior 
to  the  building.  It  deserves  lo  be  noted,  that  the  incessant  tremors  produced  in  this 
pipe  by  the  escape  of  the  steam,  cause  the  orifice  to  contract,  and  eventually  to  close 
almost  entirely,  just  as  the  point  of  a  glass  tube  does  when  exposed  directly  to  the  flame  of 
a  blowpipe.  Provision  should  therefore  be  made  against  this  event,  by  the  chemical 
engineer. 

Equidistant  between  the  middle  point  and  each  end  of  the  chamber,  two  round  holet 
are  cut  out  in  its  side,  about  16  inches  in  diameter,  and  2  feet  from  the  floor ;  the  sheet 


SULPHURIC  ACID. 


795 


%ad  being  folded  back  over  the  face  of  the  strong  deals  which  strengthen  the  chamber 
in  that  place.  The  edges  of  the  holes  are  bevelled  outwards,  so  as  to  fit  a  large  conical 
plug  of  wood  faced  with  lead,  called  a  man-hole  door.  One  or  other  of  these  doors  is 
opened  from  tune  to  time,  to  allow  the  superintendent  to  inspect  the  process,  or  work- 
men to  enter,  after  the  chamber  is  well  ventilated,  for  the  purpose  of  making  repairs. 
1  he  joists  or  tie-beams,  that  bind  the  rafters  of  the  roof  of  both  the  leaden  chamber  and 
the  house,  must  be  at  least  7  inches  deep,  by  3  broad,  and  of  such  length  as  to  have 
tneir  ends  supported  upon  the  outer  waU,  or  the  columnar  supports  of  the  roof,  in  case 
a  number  of  chambers  are  enclosed  together  in  parallel  ranges  under  a  vast  shed.  These 
beams,  which  lie  two  feet  apart,  suspend  the  leaden  roof,  by  means  of  leaden  straps 
soldered  to  its  upper  surface  and  edges.  The  sides  of  the  chamber  are  sustained  by 
means  of  similar  leaden  straps  affixed  to  the  wooden  posts  (uprights),  4  inches  broad  by  3 
thick,  placed  two  or  three  feet  apart  along  the  sides  of  the  chamber ;  resting  on  the  ground 
Jjelow,  and  mortised  into  the  tie-beams  above.  Some  chambers  rest  upon  a  sand-floor; 
but  they  are  preferably  placed  upon  wooden  joists,  supported  by  pillars  stretching  over  an 
open  irea,  as  shown  in  the  figure,  into  which  the  workmen  may  descend  readily,  to  examine 
the  bottona.  .  ' 

The  outlet  c,  on  the  top  of  the  chamber,  is  sometimes  joined  to  a  long  pipe  of  lead  laid 
nearly  horizontally,  with  a  slight  inclination  upwards,  along  the  roof,  for  favoring  the 
condensation  and  return  of  acid  matter. 

„J^^  *^®  extremity  /,  of  the  chamber,  which,  having  a  downward  slope  of  1  inch  in  every 
20  feet,  should  stand  from  3  to  6  inches  (according  to  its  length)  lower  than  t,  one  leg  of 
an  inverted  syphon  pipe  is  fixed  by  fusion,  into  which  the  liquid  of  the  chamber  passing, 
wilJ  show  by  Its  altitude  the  depth  on  the  bottom  within.  From  the  cup-shaped  orifice  of 
that  bent-up  pipe,  the  acid  of  the  chamber  is  drawn  off  by  an  ordinary  leaden  syphon  into 
the  concentration  pans. 

The  sheet  lead  of  which  the  sides  and  top  are  made  should  weigh  from  5  to  6  pounds 
per  square  foot;  that  of  the  bottom  should  be  nearly  of  double  thickness. 

Having  now  detailed,  with  sufficient  minuteness,  the  construction  of  the  chamber,  I 
shall  next  describe  the  mode  of  operating  with  it.    There  are  at  least  two  plans  at  present 
m  use  for  burning  the  sulphur  coutinuously  in  the  oven.     In  the  one,  the  sulphur  is  laid 
?"  i,  ^  u  **"*     f.'  </''•  rather  on  the  flat  hearth  in  the  separate  oven,  above  described,)  and  is 
kindled  by  a  slight  fire  placed  under  it ;   which  fire,  however,  is  allowed  to  go  out  after 
the  first  day,  because  the  oven  becomes  by  that  time  sufficiently  heated  by  the  sulphur 
flames  to  carry  on  the  subsequent  combustion.      Upon  the  hearlh,  an  iron  tripod  is  set, 
supporting,  a  few  inches  above  it,  a  hemispherical  cast-iron  bowl  (basin)  charged  with 
nitre  and  its  decomposing  proportion  of  strong  sulphuric  acid.     In  the  other  plan,  12  parts 
of  bruised  sulphur,  and  1  of  nitre,  are  mixed  in  a  leaden  trough  on  the  floor  with  1  of 
strong  sulphuric  acid,  and  the  mixture  is  shovelled  through  the  sliding  iron  door  upon 
the  hot  hearth.     The  successive  charges  of  sulphur  are  proportioned,  of  course,  to  the 
size  of  the  chamber.    In  one  of  the  largest,  which  is  120  feet  long,  20  broad,  and  16 
high,  12  cwts.  are  burned  in  the  course  of  24  hours,  divided  into  6  charges,  every  fourth 
hour,  of  2  cwts.  each.     In  chambers  of  one  sixth  greater  capacity,  containing  1400 
metres  cube,  1  ton  of  sulphur  is  burned  in  24  hours.     This  immense   production  wa« 
first  introduced  at  Chaunay  and  Dieuze,  under  the  management  of  M.  Clement-Desormes 
The  bottom  of  the  chamber  should  be  covered  at  first  with  a  thin  stratum  of  sulphuric 
acid,  of  spec.  grav.  1-07,  which  decomposes  nitrous  acid  into  oxygen  and  nitrous  gas* 
but  not  with  more  water,  which  would  absorb  the  nitrous  acid  vapors,  and  withdraw 
them  from  their  aerial  sphere  of  action.     The  vapor  of  nitric  acid,  disengaged  from 
the  nitre  on  the  hearlh  of  the  oven,  when   brought  into  intimate  contact  with  the 
sulphurous  acid,  either  gives  up  oxygen  to  it,  becomes  itself  nitrous  gas,  and  converts 
It  into  sulphuric  acid;    or  combines   with   the   sulphurous  acid   into   the   crystalline 
compound  above  described,  which,  the  moment  it  meets  with  moisture,  is  decompo^^ed 
into  sulphuric  acid  and  nitrous  gas.     The  atmospherical  oxygen  of  the  chamber  imme- 
diately reconverts  this  gas  into  nitrous  or  nitric  acid  fumes,  which  are  a^'ain  ready  with 
the  co-operation  of  sulphurous  acid  gas  and  aqueous  vaiwr,  to  produce  fresh  quantities 
Of  hydrous  sulphuric  acid  (oil  of  vitriol)  and  nitrous  gas.     At  low  temperatures,  this 
curious  play  of  chemical  affinities  has  a  great  tendency  to  form  the  crystalline  compound, 
and  to  deposite  it  in  a  crust  of  considerable  thickness  (from  one  half  to  one  inch)  on  the 
sides  of  the  chamber,  so  as  to  render  the  process  inoperative.     A  circumstance  of  this 
kind  occurred,  in  a  very  striking  manner,  during  winter,  in  a  manufacture  of  oil  of 
▼lino  m  Russia ;  and  it  has  sometimes  occurred,  to  a  moderate  extent,  in  Scotland.     It 
18  called,  at  Marseilles,  the  maladie  des  chambres.     It  may  be  certainly  prevented,  by 
maintaining  the  interior  of  the  chamber,  by  a  jet  of  steam,  at  a  temperature  of  100»  F. 
When  these  crystals  fall  into  the  dilute  acid  at  the  bottom,  they  are  decomposed  with  a 
Violent  effervescence,  and  a  hissing  gurgling  noise,  somewhat  like  that  of  a  tun  of  beer  in 
brisk  fermentation. 


■*H!>^P^9*=- 


796 


SULPHURIC  ACID. 


SULPHURIC  ACID. 


797 


I 


rni' 


M.  Clement- Desormej.  demonstrated  the  proposition  relative  to  the  influence  of  temnef^ 
tture  l^  a  decisive  experiment.  He  took  a  glass  globe,  furnished  with  three  twi^X 
and  put  a  bH  of  ice  into  it.  Through  the  first  opening  he  then  introducedsulnhuro^ 
«cid  gas;  through  the  second,  oxygen  ;  and  through  thi  third,  nitrius  gas  (de""^^^^^^^ 
azote).  VVhile  the  globe  was  kept  cool,  by  being  plunged  in  i'ced  waterfno  sulphuric  acW 
was  formed,  though  all  the  ingredients  essential  to  its  production  were  present  Buron 
exposing  the  globe  to  a  temperature  of  100-  Fahr.,  the  four  bodies  began  i^ediaTelvtS 
react  on  each  other,  and  oil  of  vitriol  was  condens^  in  visible  stride  "^^'^^^^^  ^^ 

The  introduction  of  steam  is  a  modern  invention,  which  has  vastly  facilitated  and 
increased   the  production  of  oil  of  vitriol.    It  serves,  by  powerful  T«^ftation  not  o^^^^ 
to  mix  the  different  gaseous  molecules  intimately  togelLl;  but  to  impel  Tern  a^^^^^^^ 
each  other,  and  thus  bring  them  within  the  sphere  of  their  mutual  S icll  StraS 
This  ,s  Its  mechanical  effect.     Its  chemical  agency  is  still  more  important  VsupplyTni; 
moisture  a    every  point  of  the  immense  included  space,  it  determines  the  forman\,n  of 
hydrous  sulphuric  acid,  from  the  compound  of  nitric,  nitrous,  sulphurous  and  Srv  sul- 
phunc  acids.     No  sooner  is  this  reaction  accomplished,  than  the  nitrous  gis  resumes  iU 
tlT'  ^n  '^^  ^^"^'""^"^  atmospherical  current,  and  becomes  a^a^  fiTto  operate  a 
like  round  of  transmutations  with  sulphurous  acid,  steam,  and  oxygen.  The  ni  ro-enSte^ 
which  ough   to  be  the  only  residuum  in  a  perfectly  regulated  vifrio  chambri^escapes  bj 
Its  relative  lightness  at  the  opening  c,  in  the  roof,  or,  more  properly  speaking  is  dfficed 
by  the  influx  of  the  heavier  gases  at  the  entrance-pipe.  ^PeaKing,  is  aisplaced 

On  the  intermittent  plan,  after  the  consumption  of  each  charge,  and  condensation  of 
Jhe  product,  the  chamber  was  opened,  and  freely  ventilated,  so  as VexpeHhe  res  duary 
azote,  and  replenish  it  with  fresh  atmospheric  air.     In  this  system  there  were  four  dS 
stages  or  periods:- J.  Combustion  for  two  hours;  2.  Admission  of  sLam  a nT^Sa 
for  an  hour  and  a  half;  3.  Conversion,  for  three  hoursf duiinT wh  cMnt'^val  the  ^ro^^^ 

fhZZf  T^r'^  ^'^'^  ^^"i""  "'^^  *^"^^  ^*^^^^«"^«  ^^  the  bottom  ;  4   Purging  of  ?he 
chamber,  for  three  quarters  of  an  hour.  •«^"*g*"5  "i  lac 

By  the  continuous  method,  sulphuric  acid  may  be  currently  obtained  in  the  chambers 
of  the  specific  gravity  1-350,  or  1-450  at  most ;  for,  when  stronger,  it  absorbs  and  r^talS 
permanently  much  nitrous  acid  gas;  but  by  the  int'ermittent,  so^dense  as      550^^^^^ 
1-620  ;  whence  in  a  district  where  fuel  is  hi^h  priced  as  near  P.rio  ♦»,;         »k  ^ 
mended  itself  by  economy  in  the  concentratio^n  oKe  a'c"."^'  IT^{  B^^.l'Ta  Jv'enTn" 
most  parts  of  France  however,  where  time,  workmen's  wages,  an^nteres  of  caniLTaiS 
the  paramoun   considerations,  manufacturers  do  not  find  it  for  their  "nLSstneener^^^^ 
raise  the  density  of  the  acid  in  the  chambers  above  1-400,  or  at  most  1500    as  the  further 
increase  goes  on  at  a  retarded  rate,  and  its  concentration  from  1  400^1^600  Vnkiea 
pans,  costs  very  little.  "  '  *"  leaaen 

«/k  ^^u""^  ^^l  '^"^^j^^  ^^^'^"y  ""^  ^'^^' '"  ^'^^^  Britain,  the  liquid  of  the  chambers  is  run 
ofl,  by  the  syphon  above  described,  into  a  leaden  gutter  or  spout,  which  dSr'es  it  i^to 
a  series  of  rectangular  vessels  made  of  large  sheets  of  lead,  of  12^14  lbs  to  the  sL^e 
foot,  simply  folded  up  at  the  angles  into  pans  8  or  10  inches  deep/restin-  upon  aTrSe 
made  of  a  pretty  close  row  of  wrought-iron  bars  of  considerable^rength,  under  wh7^ 
tllT  ^'k  ^  ^"  k"^'^  f  ^*^''-  "^^^'^  *^°^'^  ^'•^  ^^»y  <=heap,  each  pan  ma^  have  a^epk- 
If,n  nfX  ^^  ^*^^^t  hey  are  somewhat  dear,  the  flame,  after  passing  under  the  lowest 
pan  of  the  range,  which  contains  the  strongest  acid  (at  about  1-600)  pmceedsunwirds 
with  a  slight  slope  to  heat  the  pans  of  weaker  acid,  which,  as  it  concent?a?eTrs  gmdu^^^^ 

diSMpated.  The  3  or  4  pans  constituting  the  range  are  thus  placed  in  a  straiaht  Zp  w 
each  at  a  different  level,  terrace  like;  en  gradins^s  the  French  sS  ^  '  **"^'  *""' 

Platinu'ni^retorts,  to  u^derg'oTlrirncenfr^^^^^^^  Zl  tt"speS"vitJt  tsll  Z 

ZrZTrtZfLlZhr^^^^^^^  -'^-  -P-'t'f  Xn%fass  reform 

Tderthira  Zl^f^  flVm^^pfatfrd  Zl,\  fl^^'^adtra^^^rfrrmt  '^ 
place,  near  to  which  it  is  most  distant  from  the  tLs  L  the  relt^r  PnH^  flTh^'.  ^T 
with  tolerable  equality  on  the  first  and  last  retort  in\he  range       When  natin^ir^.f-n'' 

causes  a  safe,  rapid,  anS.  ecrorif^con^e^tf^tlon'^o?  ^Xt''^e\l'  Z^ 
7k^  '^":'  /'u '^"™    '"'"r'"'  ^""^  ^'^^   concentrated  boilL-hot   oil  of  vUrk)l  ^re 

osier  baskets  lined  with  straw.    Sometimes,  however,  the  acid  is  cooled  by  running  5 


•lowly  off  through  a  long  platinum  syphon,  surrounded  by  another  pipe  filled  with  cold 
vater.     Fig.  1419  shows  my  contrivance  for  this  purpose. 

The  under  stopcock  a,  being  shut,  and  the  leg 
6,  being  plunged  to  nearly  the  bottom  of  the  still, 
the  worm  is  to  be  filled  with  concentrated  cold 
acid  through  the  funnel  c.  If  that  stopcock  is  now 
shut,  and  a  opened,  the  acid  will  flow  out  in  such 
quantity  as  to  rarefy  the  small  portion  of  air  in  the 
4^  ^^^^^^"^^^^^^Z   ~F^  e  "PP^*^  P*''^  °^  the  pipe  6,  suflSciently  to  make  the 

ff  \  J"^   \  3         ^^t  acid  rise  up  over  the  bend,  and  set  the  syphon 

^  inaction.    The  flow  of  the  fluid  is  to  be  so  regu- 

lated by  the  stopcock  a,  that  it  may  be  greatly 
cooled  in  its  passage  by  the  surrounding  cold  water 
in  the  vessel  /,  which  may  be  replenished  by  means 
of  the  tube  and  funnel  rf,  and  overflow  at  «. 

A  manufacturer  of  acid  in  Scotland,  who  buiTH 
in  each  chamber  210  pounds  of  sulphur  in  24  hours, 
being  at  the  rate  of  420  pounds  lor  20,000  cubic 
feet  (=  nearly  2000  metres  cube),  has  a  product  ol 
nearly  3  pounds  of  concentrated  oil  of  vitriol  foi 
every  pound  of  sulphur  and  twelfth  of  a  pound  of 
nitre.  The  advantage  of  his  process  results,  I  con 
ceive,  from  the  lower  concentration  of  the  acid  in 
the  chambers,  which  favors  its  more  rapid  produc- 
tion. 

The  platinum  retort  admits  of  from  4  to  6  opera- 
lions  in  a  day,  when  it  is  well  mounted  and  man- 
aged. It  has  a  capital  of  platinum,  furnished  with 
a  short  neck,  which  conducts  the  disengaged  vapors  into  a  lead  worm  of  condensation ; 
and  the  liquid  thus  obtained  is  returned  into  the  lead  pans.  Great  care  must  be  taken 
to  prevent  any  particles  of  lead  from  getting  into  the  platinum  vessel,  since  at  the  tem- 
perature of  boiling  sulphuric  acid,  the  lead  unites  with  the  precious  metal,  and  thus 
causes  holes  in  the  retort.  These  must  be  repaired  by  soldering-on  a  plate  of  platinum 
with  gold. 

Before  the  separate  oven  or  hearth  for  burning  the  sulphur  in  contact  with  the  nitr« 
was  adopted,  this  combustible  mixture  was  introduced  into  the  chamber  itself,  spread  oa 
iron  trays  or  earthen  pans,  supported  above  the  water  on  iron  stands.  But  this  plan  was 
very  laborious  and  unproductive.     It  is  no  longer  followed. 

One  of  the  characters  of  the  good  quality  of  sulphuric  acid,  is  its  dissolving  indigo 
without  altering  its  fine  blue  color. 

Sulphuric  acid,  when  well  prepared,  is  a  colorless  and  inodorous  liquid,  of  an  oily 
aspect,  possessing  a  specific  gravity,  in  its  most  concentrated  state,  of  1*842,  when  re- 
distilled, but  as  found  in  commerce,  of  1-845.  It  is  eminently  acid  and  corrosive,  so 
that  a  single  drop  will  communicate  the  power  of  reddening  litmus  to  a  gallon  of  water, 
and  will  produce  an  ulcer  of  the  skin  when  allowed  to  remain  upon  it.  If  swallowed  in 
its  strongest  state,  in  even  a  small  quantity,  it  acts  so  furiously  on  the  throat  and  stomach 
as  to  cause  intolerable  agony  and  speedy  death.  Watery  diluents,  mixed  with  chalk  or 
magnesia,  are  the  readiest  antidotes.  At  a  temperature  of  about  600**  F.,  or  a  few  de- 
grees below  the  melting  point  of  lead,  it  boils  and  distils  over  like  water.  This  is  the 
best  method  of  procuring  sulphuric  acid  free  from  the  saline  and  metallic  matters  with 
which  it  is  sometimes  contaminated. 

The  afl5nity  of  sulphuric  acid  for  water  is  so  strong,  that  when  exposed  in  an  open 
saucer,  it  imbibes  one-third  of  its  weight  from  the  atmosphere  in  24  hours,  and  fully  six 
times  its  weight  in  a  few  months.  Hence  it  should  be  kept  excluded  from  the  air.  If 
four  parts,  by  weight,  of  the  strongest  acid  be  suddenly  mixed  with  one  part  of  water, 
both  being  at  50**  F.,  the  temperature  of  the  mixture  will  rise  to  300**;  while,  on  the 
other  hand,  if  four  parts  of  ice  be  mixed  with  one  of  sulphuric  acid,  they  immediately 
liquefy  and  sink  the  thermometer  to  4°  below  zero.  From  the  great  attraction  existing 
between  this  acid  and  water,  a  saucer  of  it  is  employed  to  effect  the  rapid  condensation 
of  aqueous  vapor  as  it  exhales  from  a  cup  of  water  placed  over  it ;  both  standing  under 
the  exhausted  receiver  of  an  air-pump.  By  the  cold  produced  by  this  unchecked  evapo- 
ration in  vacuo,  the  water  is  speedily  frozen. 

To  determine  the  purity  of  sulphuric  acid,  let  it  be  slowly  heated  to  the  boiling  point 
of  water,  and  if  any  volatile  acid  matter  be  present,  it  will  evaporate,  with  its  character- 
istic smell.  The  presence  of  saline  impurity,  which  is  the  common  one,  is  discovered 
by  evaporating  a  given  weight  of  it  in  a  small  capsule  of  platinum  placed  on  red-hot 
cinders.    If  more  than  two  grains  remain  out  of  500,  the  acid  may  be  reckoned  to  be 


\ 


798 


SULPHURIC  ACID. 


'I 


1 


impure.  The  best  test  for  sulphuric  acid,  and  the  soluble  salts  into  which  it  cnten,  Ji 
the  nitrate  of  baryta,  of  which  182  parts  are  equivalent  to  49  of  the  strongest  liquid  acid, 
or  to  40  of  the  dry,  as  it  exists  in  crystallized  sulphate  of  potassa.  Oiie  twenty  thou- 
sandth part  of  a  grain  of  the  acid  may  be  detected  by  the  grayish-white  cloud  which 
baryta  forms  with  it.  100  parts  of  the  concentrated  acid  are  neutralized  by  143  parts  of 
dry  carbonate  of  potassa,  and  by  1 10  of  dry  carbonate  of  soda,  both  perfectly  pure. 

Of  all  the  acids,  the  sulphuric  is  most  extensively  used  in  the  arts,  and  is,  in  fact,  the 
primary  agent  for  obtaining  almost  all  the  others,  by  disengaging  them  from  their  saline 
combinations.  In  this  way,  nitric,  muriatic,  tartaric,  acetic,  and  many  other  acids,  are 
procured.  It  is  employed  in  the  direct  formation  of  alum,  of  the  sulphates  of  copper, 
zinc,  potassa,  soda;  in  that  of  sulphuric  ether,  of  sugar  by  the  saccharification  of  starch, 
and  in  the  preparation  of  phosphorus,  &c.  It  serves  also  for  opening  the  pores  of  skins 
in  tanning,  for  clearing  the  surfaces  of  metals,  for  determining  the  nature  of  several  salts 
by  the  acid  characters  that  are  disengaged,  &c. 

Acconling  to  the  analysis  of  Dr.  Thomson,  the  crystalline  compound  deposited  occa- 
sionally in  the  leaden  chambers  above  described  consists  of 

Sulphurous  acid,  0*6387,  or  3  atoms.  Water        -        -    0'073?,  or  1  atom. 

Sulphuric  acid,     0-5290       2  Sulphate  of  lead,    00140.' 

Nitric  acid       -    0-3450        1  atom. 

He  admits  that  the  proportion  of  water  is  a  little  uncertain  ;  and  that  the  prese&oe  of 
sulphurous  acid  was  not  proved  by  direct  analysis.  When  heated  with  water,  the  crys- 
talline matter  disengages  nitrous  gas  in  abundance ;  lets  fall  some  sulphate  of  lead  ;  and 
the  liquid  is  found  to  be  sulphuric  acid.  When  heated  without  water,  it  is  decomposed 
with  emission  of  nitrous  gas  and  fuming  nitric  acid  ;  leaving  a  liquid  which,  mixed  with 
water,  produces  a  brisk  effervescence,  consisting  chipfly  of  nitrous  gas. 

A  valuable  improvement  of  the  process  for  manufacturing  this  fundamental  chemical 
agent  has  been  contrived  by  M.  Gay  Lussac,  and  made  the  subject  of  a  patent  in  this 
country  by  his  agent  M.  Sautter.  It  consists  in  causing  the  waste  gas  of  the  vitriol 
chamber  to  ascend  through  the  chemical  cascade  of  M.  Clement  Desormes,  and  to  en- 
counter there  a  stream  of  sulphuric  acid  of  specific  gravity  1-760.  The  nitrous  acid 
gas,  which  is  in  a  well  regulated  chamber  always  slightly  redundant,  is  perfectly  ab- 
sorbed by  the  said  sulphuric  acid ;  which,  thus  impregnated,  is  made  to  trickle  down 
through  another  cascade,  up  through  which  passes  a  current  of  sulphurous  acid,  from 
the  combustion  of  sulphur  in  a  little  adjoining  chamber.  The  condensed  nitrous  acid 
gas  is  thereby  immediately  transformed  into  nitrous  gas  (deutoxide  of  azote),  which  is 
transmitted  from  this  second  cascade  into  the  large  vitriol  chamber,  and  there  exercises 
its  well-known  reaction  upon  its  aeriform  contents.  The  economy  thus  effected  in  the 
sulphuric  acid  manufacture  is  such  that  for  100  parts  of  sulphur  3  of  nitrate  of  soda 
will  suflSce,  instead  of  9  or  10  as  usually  consumed. 

Upon  the  formation  of  sulphated  nitrous  gas  (N  0«,  8  S  0^,  2  H  OX  and  its  combina- 
tion  with  the  oil  of  vitriol,  the  manufacture  of  hydrated  sulphuric  acid  is  founded. 
Either  sulphur  is  burned  in  mixture  with  about  one-ninth  of  saltpetre :  whence  along 
with  sulphuric  acid  gas,  nitrous  oxide  gas  is  disengaged,  while  sulphate  of  potash  re- 
mains ;  thus  K  0,  N  0«  +  S  —  S  03  -f-  N  O",  K  O.  2.  Or,  nitric  acid  in  the  fluid  or 
vaporous  form  may  be  present  in  the  lead-chamber,  into  which  the  sulphurous  acid 
gas  passes,  m  consequence  of  placing  in  the  flames  of  the  sulphur  a  pan  charged  with 
a  mixture  of  sulphuric  acid  and  nitre,  or  nitrate  of  soda.  This  nitric  acid  being 
decomposed  by  a  portion  of  the  sulphurous  acid,  there  will  result  sulphuric  acid  and 
nitrous  gas.  By  the  mutual  re-action  of  the  sulphurous  and  nitric  acids,  sulphuric 
acid  and  nitrous  gas  will  be  produced ;  N  O'*  -f-  3  S  0  —  N  0'  -j-  3  S  O-"'.  3.  Or,  by 
heating  sugar  or  starch  with  nitric  acid,  the  mixture  of  nitrous  gas  and  nitrous 
acid  vapor  which  results  may  be  thrown  into  the  chamber  among  the  sulphurous 
acid.  In  any  one  of  these  three  cases,  sulphurous  acid  gas,  nitrous  acid  vapors  (pro- 
ceeding from  the  mixture  of  nitrous  oxide  and  atmospherical  oxygen)  and  steam  are 
mingled  together;  whence  arises  the  crystalline  compound  of  sulphated  nitrous  oxide 
w-ith  sulphuric  acid,  which  compound  subsides  in  white  clouds  to  the  bottom  of  the 
chamber,  and  dissolves  in  the  dilute  oil  of  vitriol  placed  there,  into  sulphuric  acid, 
with  disengagement  of  nitrous  gas.  This  gas  now  forms,  with  the  remaining  atmo- 
spherical  oxygen,  nitrous  acid  vapors  once  more,  which  condense  a  fresh  portion  of 
sulphurous  acid  gas  into  the  above  crystalline  compound;  and  thus  in  perpetual  al- 

Sulphurous  acid  gas  does  not  act  upon  nitrous  gas,  not  even  upon  the  nitrous  acid 
yapor  produced  by  the  admission  of  oxygen,  if  water  be  absent;  but  the  moment  that 
a  little  steam  is  admitted  the  crystalline  compound  is  condensed.    The  presence  of 


^ 


SULPHURIC  ACID. 


799 


much  sulphuric  acid  favors  the  formation  of  the  sulphated  nitrous  gas.    These  crystal. 

rvJinTr''.  I  k'P'^  ^^^"^^  ^'^^  disengagement  of  nitrous  ga^s,  which  sei^  S^ 
oxygen  present  and  becomes  nitrous  acid  (hyponitric  of  many  chemists). 

acid  ?n^hT  Sl^Mn«f  ^^°^  .'u'^^'^wu^*'^  "^^H^  «^«°^*  ^«  condense  their  waste  muriatic 

J^Pcrh  f  in  r  '  ^""^  r"  u  '^^^  "S^^°  '"^""°  ^  ^^«  nuisance-creating  system  if  they 
might  In  time,  no  doubt,  the  copper  smelter  will  also  be  compelled  to  arrest  the 
poisonous  fumes  now  so  wantonly  evolved ;  and  then  he  too  will  G  a  profiTin  that 
which,  at  present,  only  injures  his  neighbor.  It  is  with  individual  intereste  as  wiS 
physical  bodies,  the  largest  are  the  most  difficult  to  move  from  any  estabHshed  tS^iuia 

l^oL"-'a{/TH"^"H""-''!f  P^""r?^  "?^^  ^°  '"^^  country  wL  made  from^ul^^^^^ 
alone,  and,  although  scientific  men  had  pointed  out  iron  p/rites  as  an  abundant  in. 
dipnous  source  for  the  generation  of  this  acid,  yet  no  attention  whatever  was  g^^en  to 
this  seenimgly  value  ess  information.  Folly,  however,  achieved  that  which  w™om  could 
no  reach ;  and  the  infatuated  cupidity  of  a  Sicilian  king  compelled  our  manufacture™ 

p^  f  /  r'"'"^  ^""^  ^  !:^^  ^V""^  ^^  «"^«°«^'  *°^  «^«k  at  home  that  which  aTohiWtiy^ 
export  duty  prevented  them  from  obtaining  abroad.    Their  eves  were  at  lpn£h  nl.^n^ 
and    too  late,  the  King  of  Sicily  saw  his  error;  for,  th^grtL  exces^^^^^^^^ 
sulphur  has  since  been  removed,  it  has  not  only' failed  to  put  down  thT  use  oMrnn 
pyrites,  but  the  best  informed  authorities  are  decidedly  of  o&nion  That  this Ttfpr  wm 

furnish  the  essential  element  for  the  fabrication  of  nearly  all  our  sulphuriracid  ThlrA 
11^^  however  one  very  serious  drawback  to  the  generaf  use  of  iron  pyrtes  for  su^^^^^ 
purpose,  and  that  is,  the  presence  of  arsenic  in  all  the  acid  thus  madl^  tL  obSon 

^.n  i!  -^^  Pf.!-"- *^  ^"^  '^'  "^"^^'"^^  «^^"«^  of  mechanical  and  chemical  gSiS  alone 
Wn  i''"^'  f'J"  important  manufacture  from  so  great  an  obstacle.  Means^have  inS 
b«rfll'«r'^  ^''-  ?'3^'^-\^  V^^  ^''""^"  ^"^"^  *^«  ««'^  ^f<^r  the  formation  of  the  atte^ 
a  prSirfS.^^^^^^  ^''^  the  practical  working  of  sulphuric  acid  well  know  that  such 
XTnVwith  thrdlrfr^l'  ^^^  '\'  ^^^^  ''"^"-  '^^^'^  ^^^^  ^^  ^^^^  ^ut  two  mode, 
at  all  KvJn  fl  ^"^^'  ^^l"""^  ^^'°^  ^  P^^^'^^t  the  volatilization  of  the  arsenic 
at  all,  by  mixing  the  pyrites  with  some  suitable  ingredient  ere  it  is  thrown  into  fh« 
furnace ;  and  the  other,  to  remove  the  arsenic  from  the  sulphurou  acid  Wo^e  it  reache! 
tl  f^T^f  ""^  condensation.  The  first  would  be  the  simplest  plan  ;  b^t Tn  the  e^? 
bevotl  f  h""/ ''''°''f  '"°  ""^'"'^^  ^"  *i°P^^  ^^^-  The  last,  howeve?,  is  iot  by  any  mTn^ 
thHrsPni  K  -P'  ""'  Pt"7«»-*°<?  «"<i  ingenuity.    It  must  be  borne  in  mind.  thal,^trouffh 

tV^Z'^^lVtt'^''^  '''Tr  "f^  ^*^^°  ''  ^^^^^«  thefurnice  w/th  tie 
fnffilo  ?  ' .  ?.  "*  the  gaseous  state,  yet  a  very  trifling  reduction  of  temneratura 

suffices  to  conver  it  into  solid  powder ;  in  which  condition  it  is  merely  cairiedo^^^^^^ 
mechanically,  by  the  current  of  sulphurous  acid;  and  thus  reaches  the  Sen  chalbe? 
The  mixture,  therefore,  resembles  that  of  turbid  water-  and  bearing  thi««n«i^ - 
mind  ^e  shall  now  proceed  to  describe  the  Pyritic  process  of  mak^"^^^^^^^^^ 
adding,  as  we  go  on,  a  hint  at  the  proper  place  for^^arresting  the  arinious  fumer  a^ 
thus  producing  a  pure  and  satisfactory  acid,  equal  to  that  obtained  froSlianTuTnhi 
The  furnace  employed  for  roasting  iron  pyrites  is  very  peculiar,  but  e^nt  X  eon^S^ 
of  an  inverted  cone,  with,  of  course,  a  small  area  of  L-grat^    in  p^nort^o^n  ?n   l^ 
o?  aTr  thTn' Wh'^  f"'  fumace,-the  object  of  this  bein.,  tofrev;nt  thSus^^^^^ 
nLf ^f  ^h     ^^  ^^^  f"'°^l''  ^""^  ^*"««  '^«  ^"^^•'"^^  ««U«r  to  bum  only  at  the  u^SJ 

upper  openings  are  no  longer  useful,  but  must  be  closed  so  as  to  cornnpHh^  Ihnl  ? 
the  air  to  pass  through  the  red-hot  protosulphuretaid  thu«  fnr^f  i  ^  *^^^  ^I 
and  oxide  of  iron.-the  latter  of  whic^h  is  ultWely  wkhdr^^^^^  ^i^^"~"'r^^ 
An  iron  pan  containing  nitrato  of  soda,  is  usuall/pW  Ke  L*  !^^^^^ 
number  of  these  furnaces,  to  supply  nitric  oxide  ga^s-  and  the  whoTnrfL 
products  are  made  to  pass  through  a  considerable  length  of  tuHn^«nbiw/?fK^ 
JhlXS  :frnd1ntiot'  -  -  ''  -^  ^'^  ^se^^^^.^'^t^ 

41^%^^^^^^^^^^  ^o^LdVlTti^Kf  rJ^'  T^'  *^^f r 

substance;  and  therefore  we  now  procUd  to  eon^iZ.  fl      ^?-  **'%^"P^'*^?'*°.*  °^^*'**' 
volatile  mixture  the  arsenicarmatters  wl  fchTt  hoM   '  '^"''^'''''  ""-^  ''T^'°/  ^'^^^  ^^^ 


m 


800 


SULPHURIC  ACID. 


SUMACH. 


801 


suffer^  but  a  trifling  contraction  in  its  bulk.  "We  requested  attention  to  the  case  of 
turbid  water  as  a  simile  whence  to  acquire  a  correct  notion  of  the  kind  of  mixture 
passing  into  a  condensing  chamber ;  and  this  suggests  also  the  means  of  purification. 
With  turbid  water  filtration  might  indeed  be  resorted  to,  which  is  inapplicable  to  our 
difficulty;  but  there  is  another  mode  in  which  water  is  purified  by  nature  on  the  large 
scale,  and  that  is,  by  deposition,  or  attraction  of  gravitation.  Por  this  purpose  absolute 
rest  is  not  necessary;  as  may  be  seen  on  examining  the  water  running  into  and  out  of 
a  lake  in  spring  or  autumn.  It  enters  foul  and  muddy ;  but,  at  its  exit,  is  clear  and 
pellucid  as  crystal.  This  is  precisely  the  object  desired  with  respect  to  the  gaseous 
products  given  off  from  a  pyrites  furnace,  and  may  be  accomplished  in  precisely  the 
same  way.  Let  a  gaseous  lake,  or  lai^e  chamber  in  brickwork,  be  interposed  between 
the  refrigerating  tube  and  the  condensation-chamber,  through  which,  of  course,  the 
contaminated  sulphurous  acid  would  flow,  but  so  slowly  as  to  deposit,  like  the  water 
in  the  lake,  the  mechanical  impurities  suspended  in  it,  and  thus  pass  pure  and  unde* 
filed  into  the  leaden  chamber,  possessing  now  all  the  properties  and  uses  of  that  ob- 
tained by  the  combustion  of  pure  sulphur.  The  size  of  this  gaseous  lake  or  arsenical 
precipitator,  as  it  might  be  termed,  would  require  adjustment  according  to  the  area  of 
the  entrance  tube  and  the  velocity  of  the  current,  but  need  not^  perhaps,  be  more  than 
one  half  of  the  cubical  contents  of  the  leaden  chamber,  especially  if  the  gas  entered 
below  and  issued  from  the  top. 

We  are  now  arrived  at  the  point  where  the  modes  of  using  pyrites  and  sulphur  unite: 
consequently,  it  will  be  necessary  to  examine  the  early  steps  in  the  employment  of 
this  latter.  These  are  quite  as  simple  as  the  management  of  a  common  hre, — for  the 
sulphur  is  merely  thrown  into  a  kind  of  oven,  provided  with  a  door  capable  of  regulat- 
ing the  admission  of  air;  and  near  to  this  door,  but  within  the  oven,  an  iron  pot  con- 
taining nitrate  of  soda  is  placed,  the  contents  of  which  are  in  the  proportion  of  about  6 
per  cent  of  the  nitrate  to  a  given  amount  of  sulphur.  The  sulphur  having  been  once 
lighted,  combustion  goes  on  continuously,  and  the  volatile  products, after  passing  through 
the  refrigerating  tube,  ultimately  enter  the  condensing  chamber ;  here  they  are  met  by 
a  current  of  steam,  which  causes  the  compound  of  sulphur,  nitrogen,  and  oxygen,  to 
fall  to  the  bottom  of  the  chamber,  and,  in  combining  with  the  water  there  placed,  de- 
composition ensues,  attended  with  the  formation  of  sulphuric  acid  and  nitric  oxide  gas; 
the  former  of  which  remains  in  solution,  whilst  the  latter  rises,  and  uniting  to  a  fresh  por- 
tion of  sulphurous  acid,  and  to  part  of  the  oxygen  in  the  chamber,  again  falls,  and  is 
decomposed  as  before,  until  either  no  more  sulphurous  acid  or  oxygen  gas  remains  in 
the  chamber,  the  latter  of  which  circumstances  would  imply  bad  management,  and  is 
probably  the  cause  of  what  is  termed  "chamber  sickness.  This  condensation  process 
lasts  many  hours,  and  sometimes  even  days  are  spent  in  its  completion,  the  workmen 
judging  of  its  progress  by  the  color  of  the  fumes  displayed  on  opening  a  small  door  or 
aperture  near  the  bottom  of  the  chamber ;  by  which  they  also  form  an  opinion  as  to  the 
excess  or  deficiency  of  nitrous  vapor,  and  apply  the  appropriate  remedy  in  the  combus- 
tion furnace.  When  the  water  on  the  floor  of  the  chamber  has  received  a  certain 
amount  of  sulphuric  acid,  it  ceases  to  act  favorably  upon  the  gaseous  mixture,  and  is 
therefore  withdrawn.  For  many  purposes  in  the  arts,  such  acid  is  quite  strong 
enough ;  and  hence,  under  the  name  "chamber  acid,**  it  is  extensively  employed.  Bnt» 
to  complete  its  character  as  oil  of  vitriol,  this  chamber  acid  is  evaporated,  first  in 
leaden  vessels,  but  ultimately  in  a  platinum  boiler,  set  over  the  naked  fire,  and  pro- 
vided with  a  head  or  cover,  and  a  syphon  tube,  all  in  platinum :  by  the  syphon  tube 
the  operator  is  enabled  to  draw  off  the  concentrated  acid  when  sufficiently  evaporated. 
A  boiler  of  this  kind  is  kept  constantly  in  action  after  the  fire  has  been  once  lighted 
the  only  cause  of  stoppage  being  the  necessity  for  repairs,  which  are  vastly  more  fre- 
quent than  might  be  imagined,  considering  the  imperishable  nature  of  the  metal  em- 
ployed in  the  construction  of  these  boilers.  Selenious  acid  is  thought  to  be  the  corro- 
ding agent,  and  perhaps  correctly,  as  chlorine  is  quite  out  of  the  question. 

Concentrated  dry  sulphuric  acid  of  Nordhausen.  M.  Paul  Gilbert  Prelier,  of  Parian 
has  patented  the  following  plan  of  manufacturing  dry  sulphuric  acid.  He  employs  100 
parts  of  sulphate  of  soda,  2  parts  of  sulphate  of  potash,  and  2  parts  of  sulphate  of  lime. 
The  mixture  is  put  into  freestone  retorts  (cornwea  de  gres'f)  set  in  a  suitable  furnace ;  then 
by  means  of  a  bent  glass  tube,  the  acid  is  introduced  into  the  retorts,  and  heat  is  gradually 
applied.  Shortly  after  the  application  of  heat,  drops  of  water  will  fall  from  the  retort^ 
then  acidulated  water,  followed  by  acid  at  40°,  60°,  and  66°  Baura6,  and  finally  by  acid 
which  fumes  or  smokes.  To  enable  the  operator  to  judge  correctly  of  the  progress  of 
the  operation,  vessels  containing  water  are  placed  to  receive  the  drops  of  acid ;  and  when 
each  drop  produces  a  sound  resembling  that  which  a  red-hot  iron  would  cause  in  the 
water,  the  dry  acid  is  produced,  and  is  to  be  collected.  Nordhausen  acid  is  obtained, 
he  says,  by  introducing  oil  of  vitriol,  at  66'^  Baume,  into  the  vessels  which  receive  the  dry 


acid.     But  this  Nordhausen  acid  is  colorless,  and  pure.     He  does  not  specify  the 
quantity  of  oil  of  vitriol  that  he  introduces  at  first  along  with  the  sulphates. 

Anhydrous  Sulphuric  Acid  Highly  concentrated  oil  of  vitriol  must  be  mixed  with 
dry  phosphoric  acid,  obtained  by  the  combustion  of  phosphorus  beneath  a  receiver 
placed  over  a  plate  of  glass,  allowing  free  access  for  dry  atmospheric  air.  On  mix- 
ing the  two  acids,  a  strong  chemical  action  ensues,  with  considerable  elevation  of 
temperature ;  and  therefore  the  mixture  should  be  made  in  a  retort  surrounded  by  a 
freezing  mixture,  the  phosphoric  acid  being  previously  cooled,  and  the  cold  oil  of  vitriol 
being  gradually  added ;  allowing  the  heat  to  subside  after  each  addition.  When  a 
quantity  of  oil  of  vitriol  equal  to  about  two-thirds  the  weight  of  the  phosphoric  acid 
has  been  thus  added,  the  mixture  which  has  acquired  a  dark  brown  color,  is  removed 
from  the  cooling  bath,  and  a  receiver  is  placea  there,  to  which  the  retort  has  been 
adapted,  A  gentle  heat  is  now  applied  to  the  retort,  and  dense  white  vapors  soon  be- 
gin to  pass  into  the  receiver  where  they  are  condensed  by  the  cold.  In  this  way  a 
considerable  quantity  of  beautiful  white  silky  crystals  are  obtained.  With  careful 
manipulation,  an  ounce  of  phosphorus,  converted  into  anhydrous  acid  by  combustion 
in  dry  air,  will  yield  one  ounce  of  anhydrous  sulphuric  acid.  If  a  few  drops  of  water 
be  added,  a  dangerous  explosion  ensues. — BarreswilL 

The  following  Table  shows  the  quantity  of  concentrated  and  dry  sulphuric  acid  in  IOC 
parts  of  dilute,  at  different  densities,  by  my  experiments,  published  in  the  Quarterly 
Journal  of  Science,  for  October,  1817 : — 


Liquid. 

Spec  gravity. 

Dry. 

Liquid. 

Spec,  gravity. 

Dry. 

Liquid. 

Spec,  gravity. 

Dry. 

100 

1-8460 

81-54 

66 

1-5503 

53-82 

32 

1-2334 

26-09 

99 

1-8438 

80-72 

65 

1  5390 

53-00 

31 

1-2260 

25-28 

98 

1-8415 

79-90 

64 

1-5280 

52-18 

30 

1-2184 

24-46 

97 

1-8391 

79-09 

63 

1-5170 

51-37 

29 

1-2108 

23-66 

96 

1-8366 

78-28 

62 

1-5066 

50-55 

28 

1-2032 

22-83 

95 

1-8340 

77-46 

61 

1-4960 

49-74 

27 

1-1956 

22-01 

94 

1-8288 

76-65 

60 

1-4860 

48-92 

26 

1-1876 

21-20 

93 

1-8235 

75-83 

59 

1-4760 

48-11 

25 

1-1792 

20-38 

92 

1-8181 

75-02 

58 

1-4660 

47-29 

24 

1-1706 

19-57 

91 

1-8026 

74-20 

57 

1-4560 

46-48 

23 

M626 

18-75 

90 

1-8070 

73-39 

56 

1-4460 

45-66 

22 

1-1649 

17-94 

89 

1-7986 

72-57 

55 

1-4360 

44-85 

21 

1-1480 

17-12 

88 

1-7901 

71-75 

54 

1-4265 

44-03 

20 

1-1410 

16-31 

87 

1-7815 

70-94 

53 

1-4170 

43-22 

19 

1-1330 

15-49 

86 

1-7728 

70-12 

52 

1-4073 

42-40 

18 

1-1246 

14-68 

85 

1-7640 

69-31 

51 

1-3977 

41-58 

17 

1-1165 

13-«6 

84 

1-7540 

68-49 

50 

1-3884 

40-77 

16 

1-1090 

13-05 

83 

1-7425 

67-68 

49 

1-3788 

39-95 

15 

1-1019 

12-23 

82 

1-7315 

66-86 

48 

1-3697 

39-14 

14 

1-0953 

11-41 

81 

1-7200 

66-05 

47 

1-3612 

38-32 

13 

1-0887 

tO-60 

80 

1-7080 

65-23 

46 

1-3530 

37-51 

12 

1-0809 

9-78 

79 

1-6972 

64-42 

45 

1-3440 

36-69 

11 

1-0743 

8-97 

78 

1-6860 

63-60 

44 

1-3345 

35-88 

10 

1-0682 

8-16 

77 

1-6744 

62-78 

43 

1-3255 

35-06 

9 

1-0614 

7-34 

76 

1-6624 

61-97 

42 

1-3165 

34-25 

8 

1-0544 

6-62 

75 

1-6500 

61-15 

41 

1-3080 

33-43 

7 

1-0477 

5-71 

74 

1-6415 

60-34 

40 

1-2999 

32-61 

6 

1-0405 

4-89 

73 

1-6321 

59-52 

39 

1-2913 

31-80 

5 

1-0336 

4-08 

72 

1-6204 

58-71 

38 

1-2826 

30-98 

4 

1-0268 

3-26 

71 

1-6090 

57-89 

37 

1-2740 

30-17 

3 

1-0206 

2-446 

70 

1-5975 

57-08 

36 

1-2654 

29-35 

2 

1-0140 

1*63 

69 

1-5868 

56-26 

35 

1-2572 

28-54 

1 

1-0074 

0-8154 

68 

1-5760 

55-45 

34 

1-2490 

27-72 

67 

1-6648 

64-63 

33 

1-2409 

26-91 

SUMACH  (Eng.  and  Fr. ;  Schmack,  Germ.) ;  is  Uie  powder  of  the  leaves,  peduncles 
and  young  branches  of  the  Rhus  coriaria  and  Hhus  cotinuSy  shrubs  which  grow  in  Hun- 
gary, the  Bannat,  and  the  Illyrian  provinces.  Both  kinds  contain  tannin,  with  a  little 
yellow  coloring  matter,  and  are  a  good  deal  employed  for  tanning  light-colored 
leathers ;  but  the  first  is  the  best    With  mordants  it  dies  nearly  the  same  colors  m 


ispi' 


802 


SUN  PAINTING. 


galls.  In  calico-printing,  snroach  affords,  with  a  mordant  of  tin,  a  yellow  color ;  with 
acetate  of  iron,  weak  or  strong,  a  grey  or  black ;  and  with  sulphate  of  zinc,  a  brownish- 
yellow.  A  decoction  of  sumach  reddens  litmus  paper  strongly ;  gives  white  fiocka 
with  the  proto-muriate  of  tin ;  pale-yellow  flocks  with  alum ;  blue  flocks  with  red 
sulphate  of  iron,  with  an  abundant  precipitate.  In  the  south  of  France  the  twigs  and 
leaves  of  the  Coriaria  myrthifolia  are  used  for  dyeing,  under  the  name  of  redoul  or  roekm, 

SUN  PAINTING  or  HELIOGRAPHY.  This  elegant  art  having  been  cultivated 
with  ren>arkable  success  by  Sir  William  John  Newton,  Knt,  I  have  great  pleasure  in 
transferring  into  this  Dictionary  the  very  specific  instructions  which  he  has  published 
00  the  subject  in  the  first  number  of  the  "  Photc^raphic  Journal." 

To  iodize  the  Paper. — Ist*  Brush  your  paper  over  with  muriate  of  barytes  (half  ain 
ounce,  dissolved  in  nearly  a  wine-bottle  of  distilled  water) :  lay  it  flat  to  dry.  2d. 
Dissolve  sixty  grains  of  nitrate  of  silver  in  about  an  ounce  of  distilled  water.  Ditto 
sixty  grains  of  iodide  of  potassium  in  another  bottle  with  the  like  quantity  of  water. 
Mix  them  together  and  shake  well :  let  it  subside  :  pour  off  the  water,  and  then  add  hot 
water  :  shake  it  well :  let  it  subside :  pour  off  the  water,  and  then  add  three  ounces  of 
distilled  water,  and  afterward  as  much  iodide  of  potassium  as  will  redissolve  the  iodido 
of  silver. 

Brush  your  previously-prepared  paper  well  with  this,  and  let  dry ;  then  place  them 
in  water,  one  by  one,  for  about  one  hour  and  a  half  or  two  hours,  constantly  agitating 
the  water.  As  many  as  a  dozen  pieces  may  be  put  into  the  water,  one  after  the  other, 
taking  care  that  there  are  no  air  bubbles ;  take  them  out,  and  pin  to  the  edge  of  a  board 
at  one  corner. 

When  dry  they  will  be  ready  for  exciting  for  the  camera  by  the  following  process : 


1  drachm  of  No.  4.  6 
drachms  of  distilled  water. 


4 

25  grains  of  nitrate  of  sil- 
ver to  half  an  ounce  of 
water.  Add  45  minims  of 
glacial  acetic  acid. 


2 

20  min.   of  No.   8,  6 
drachms  of  distilled  water. 


2  drachms  of  No.  4,  6  drs. 
of  water. 


A  saturated  solution  of  gal- 
lic acid. 


Equal  parts  of  Nos.  1  and  2. 

N.  B.  —  This  must  be 
mixed  just  before  using, 
and  the  bottle  cleaned  af- 
terward. 


(These  are  supposed  to  be  in  six  1-ounce  bottles  with  glass  stoppers.) 

To  excite  for  the  Camera. — Mix  equal  parts  of  Nos.  1  and  2,  and  with  a  glass  rod 
excite  the  iodized  paper  and  blot  off ;  and  it  may  be  put  in  the  slide  at  once,  or  the 
number  you  require  may  be  excited,  and  put  into  a  blotting-paper  book,  one  between 
each  leaf,  and  allowed  to  remain  until  required  to  be  placed  in  the  slide. 

2Kme  of  Expomre. — ^The  time  varies  from  three  minutes  to  a  quarter  of  an  hour, 
according  to  the  nature  of  the  subject  and  the  power  of  the  sun ;  out  five  minutes  is 
generally  the  proper  time. 

To  bring  out. — ^Bring  out  with  No.  8,  and  when  the  subject  begins  to  appear,  add 
Na  5 ;  and  when  sufficiently  developed  hold  it  up,  and  pour  water  upon  it ;  and  then 
put  it  into  hyposulphite  of  soda  to  nx  it,  for  about  half  an  hour  or  more,  and  then  into 
water :  this  is  merely  to  fix  it  for  the  after  process  at  your  leisure. 

To  clean  the  Negative. — Get  a  zinc  tray  about  three  or  four  inches  deep,  with  another 
tray  to  fit  in  at  the  top,  about  one  inch  deep ;  fill  the  lower  tray  with  boiling  water,  so 
that  the  upper  tray  may  touch  the  water ;  put  your  solution  of  hyposulphite  of  soda, 
not  strong  in  the  upper  tray,  and  then  your  negatives  one  by  one,  watching  them  with 
care  until  the  iodine  is  removed ;  then  put  them  in  hot  water,  containing  a  small  piece 
of  common  soda  (the  size  of  a  nutmeg  to  about  two  quarts  of  waterl  for  about  ten 
minutes;  pour  off  the  dirty  water,  and  then  add  more  hot  water,  shaking  them  gently 
for  a  short  time;  pour  off  the  water  again,  and  then  add  fresh  hot  water,  and  let  it  re- 
main until  it  is  cold,  after  which  take  them  out  carefully  one  by  one,  and  put  them  in 
clean  cold  water  for  an  hour  or  two;  then  take  them  all  out  together,  and  hold  np  to 
drain  for  a  short  time,  and  then  put  them  between  three  or  four  thicknesses  of  linei^ 
and  press  as  much  of  the  water  out  as  you  can ;  then  carefully  (for  now  all  the  sizo 
is  removed)  lay  them  out  flat  separately  upon  linen  to  dry. 


SUN  PAINTING. 


803 


Mode  of  Waxing  the  Negative*, — Melt  the  pure  white  wax  over  a  lamp  of  moderate 
heat,  just  merely^  to  keep  it  in  a  liquid  state ;  then  fill  the  same  deep  tray  as  above  de- 
scribed with  boiling  water,  and  with  another  similar  to  the  upper  one  before  described 
(which  must  be  kept  for  this  purpose  only) ;  put  a  clean  piece  of  blotting-paper  in  this 
tray,  and  lay  your  negative  face  downwards,  and  with  a  soft  flat  hog's  hair-brush,  about 
an  inch  wide,  dip  it  into  the  liquid  wax,  and  brush  the  negative  over,  when  it  will  be 
immediately  transparent,  and  it  can  be  done  so  that  there  is  very  little  redundant  wax, 
after  which  it  may  be  put  between  two  or  three  thicknesses  of  blotting-paper  and  ironed, 
if  necessary,  which  should  not  be  very  hot,  when  it  is  ready  to  take  positives  from. 

Positives  on  Negative  Paper. — ^Take  one  part  of  the  iodide  of  silver  before  described 
and  add  two  parts  of  water ;  then  add  as  much  iodide  of  potassium  as  will  redissolre  it 
Brush  your  paper  with  the  foregoing,  let  dry,  put  into  water,  and  proceed  in  all  re- 
spects, as  above  described  for  the  negatives. 

Excite  for  positives. — Excite  with  No.  1;  blot  off;  lay  it  in  your  press,  place  the 
negative  face  downwards ;  expose  to  the  light  from  ten  seconds  to  half  a  minute,  or  more 
according  to  the  light  (not  in  the  sun),  and  bring  out  with  No.  3  ;  and  when  it  is  nearly 
developed  add  No.  1 ;  then  take  it  up  and  pour  water  upon  it,  and  then  place  it  in 
hyposulphite  of  soda  (cold)  until  the  iodide  is  removed ;  after  which  put  it  into  alum 
water,  about  half  a  teaspoonful  of  powdered  alum  in  two  quarts  of  water ;  this  will 
readily  remove  the  hyposulphite,  and  also  fix  the  positive  more  particularly ;  it  will 
also  take  away  any  impurities  which  there  may  be  in  the  paper,  alter  which  put  it  into 
clean  cold  water,  and  change  two  or  three  times. 

I  have  been  thus  particular  in  describing  the  process  which  I  have  adopted,  more 
especially  for  beginners ;  and  with  great  cleanliness  and  care  in  each  process,  and 
especially  in  keeping  all  the  bottles  with  the  chemicals  free  from  dirt  of  every  kind, 
the  foregoing  will  lead  to  favorable  results. 

Motive  for  washing  the  paper  over  with  chloride  of  barium  previous  to  iodizing. — In 
the  first  place,  I  find  that  it  appears  to  give  strength  to  the  paper. 

Secondly,  that  the  action  in  the  camera  is  better  and  more  certain. 

Thirdly,  it  keeps  cleaner  in  the  bringing-out  process,  thereby  allowing  a  longer  time 
for  a  more  complete  development. 

Fourthly,  I  have  never  found  any  solarizing  take  place  since  I  have  used  it  (about 
three  years) ;  and,  fifthly,  I  find  that  it  keeps  longer  and  better  after  it  is  excited  for 
the  eamera. 

From  the  observations  which  I  have  made  since  I  have  made  use  of  chloride  of  bari- 
um, I  conclude  that  it  has  the  effect  of  destroying  any  injurious  properties  which  may 
be  in  the  paper,  and  more  especially  with  respect  to  the  size ;  and  besides  which,  when 
combined  with  iodide  of  silver,  greater  intensity  is  obtained  in  the  negative. 

I  have  occasionally  prepared  paper  without  chloride  of  barium,  but  I  have  always 
found  (except  for  positives)  that  I  could  not  rely  upon  it  with  the  same  degree  of  cer- 
tainty. I  need  scarcely  add  that  throughout  the  whole  of  this  process  the  greatest  care 
and  attention  are  required,  and  that  the  water  should  be  constantly  agitated  while  the 
paper  is  in  it,  and  that  the  water  should  be  once  changed. 

Rationale  of  the  action  of  the  common  soda  and  powdered  alum^  dsc. — ^My  motive  for 
nsing  common  soda  to  cleanse  the  negatives  is,  that  it  not  only  removes  tiie  hypo- 
sulphite of  soda  more  readily,  but  any  impurities  which  may  be  in  the  paper,  as  well 
as  the  whole  of  the  size,  such  being  absolutely  necessary  for  the  after  waxing  process ; 
which,  when  done,  the  negative  should  appear  nearly  as  transparent  as  glass. 

Tho  reason  why  I  prefer  alum  for  the  positives  is,  that  while  it  has  the  effect  of  re- 
moving the  hyposulphite  (A  soda  and  other  impurities  in  the  paper,  it  does  not  act 
upon  the  size,  which  in  this  instance  it  is  desirous  to  retain. 

I  have  been  induced  to  make  a  series  of  experiments,  with  a  view  to  prevent  the 
fading  of  the  positives,  or,  indeed,  that  any  portion  should  be,  as  it  were  eaten  away  in 
parts;  and  since  I  have  adopted  the  foregoing  in  no  one  instance  has  any  change  tAcen 
place  whatever. — Sir  W.  J.  Newton. 

Mr.  Fenton,  one  of  the  most  expert  and  successful  heliographers,  recommends  for 
pi^r  to  be  used  the  same  day  that  it  is  excited,  two  grammes  of  common  salt  to  be 
added  to  the  iodizing  solution.  This  addition  increased  the  rapidity  of  the  formation 
of  the  picture,  but  much  lessened  the  time  during  which  the  paper  could  be  kept  in  a 
sensitive  state  uninjured.  The  solution  for  exciting  the  paper  was  the  usual  one  of  SO 
grammes  of  nitrate  of  silver,  and  half  a  drachm  of  acetic  acid  to  the  ounce  of  water. 
The  paper  on  which  the  greater  part  of  Mr.  Fenton's  negatives  were  taken  was  iodized 
by  the  following  preparation : — 

Rice  water  -        -        -        .  looo  gramme* 
Iodide  of  potassium      .        .      SO 
Bromide  of  potassium  -        -         8 
Cvanide  of  potassium  -        -        2 
Fluoride  of  potassium  -       •       li 


I 


804 


SYRUP. 


An  even  film  of  collodion  may  be  obtained  by  the  following  means.    Represent  tlie 
plate  of  glass  by  the  following  figure : — 


Hold  the  plate  with  the  left  hand  at  1,  pour  a  body  of  collodion  in  the  centre,  tilt 
towards  1  (being  careful  not  to  let  it  touch  the  thumb),  incline  towards  2,  run  into  8, 
and  pour  oflf  at  4.  Then  hold  the  plate  vertically  (resting  the  corner  4  on  the  neck  of 
the  collodion  bottle)  to  drain ;  incline  it  first  to  the  right  and  then  to  the  left^  repeating 
this  several  times  until  the  ridges  are  removed.  By  these  means  an  even  film  may  be 
produced  without  a  thick  ridge  from  2  to  4.  The  time  it  may  be  left  without  plunging 
into  the  silver  bath  will  depend  upon  the  temperature  (about  half  a  minute).  Dip 
evenly  into  the  bath,  lifting  up  and  down  to  allow  the  evaporation  of  the  ether;  the 
film  will  also  saturate  more  rapidly.  When  the  greasy  appearance  is  gone,  it  is  ready 
for  the  camera.  Sometimes  the  film  is  nearly  transparent  and  bluish,  not  having  suf- 
ficient iodide  of  silver ;  or  it  may  contain  too  much  iodide,  the  greater  part  flaking  oflf 
in  the  bath,  leaving  the  collodion  with  very  little,  and  that  patchy ;  or  from  being 
placed  in  the  bath  too  quick,  the  lower  corner  will  present  a  reticulated  appearance, 
which  of  course  renders  it  useless. 

Having  exposed  the  plate  the  necessary  time,  the  next  step  is  the  development  The 
solution  employed  by  some  is  prepared  with  protosulphate  of  iron.  The  proportions 
are,— 


"Water 

Acetic  acid  {Beaufoy'i) 
Protosulphate  of  iron 
Nitric  acid 


-  2  oz^ 

-  1  drachm 

-  8  grains 

-  2  drops. 


Mix  the  water  and  acetic  acid  first ;  then  dissolve  the  sulphate  of  iron,  and,  lastly,  add 
the  nitric  acid,  which,  by  varying  the  quantity,  produces  different  effects.  On  pouring 
the  solution  over  the  plate,  there  is  sometimes  a  difficulty  experienced  in  causing  it  to 
flow  evenly.  Sometimes  a  little  more  acetic  acid  in  the  developing  solution,  or,  if  the 
plate  has  been  out  of  the  bath  for  some  time,  redipping  it,  will  prevent  this ;  but  if  this 
does  not  remove  it,  and  the  resulting  picture  is  hard  and  unpleasant  in  tone,  anew  bath 
is  necessary.  For  positives  the  resulting  picture  is  more  pleasing  and  delicate,  by  using 
the  developing  agent  rather  weak.  After  it  has  remained  on  sufficiently  long  to  bring 
out  the  image,  the  undecompounded  iodide  is  to  be  removed  by  hyposulphate  of  soda. 

SUSPENSION  BRIDGES.  Suspension  bridges  of  iron  were  introduced  about  the 
year  1741,  at  which  date  one  of  70  feet  span  was  thrown  over  the  river  Tees.  Sca- 
mozzi,  Del  Idea  Archi,  published  1615,  conveys  some  notion  of  these  structures;  but 
Bernouilli  first  explained  their  true  principles.  The  Union  bridge  over  the  Tweed  449 
feet  span,  constructed  by  Captain  Sir  S.  Brown,  in  1820,  was  the  first  large  bar  chain 
bridge  erected  in  Britain.  The  Newhaven  and  Brighton  suspension  piers  were  also 
erected  by  the  same  engineer.  The  great  bridge  by  Telford,  across  the  Menai  Straits, 
is  670  feet  span;  it  was  commenced  in  May,  1819,  and  completed  in  December,  1826. 
The  Hammersmith  bridge,  422  feet  span,  by  Tierney  Clark,  was  completed  in  1824. 
The  Montrose  bridge,  by  Rendel,  412  feet  span,  was  erected  in  1829 ;  and  the  Hunger- 
ford  bridge  over  the  Thames,  67 6i  feet  span,  by  Brunei,  was  built  in  1844.  The  wire- 
rope  bridge  of  Freiburg  is  820  feet  span.  The  road-ways  of  suspension  bridges  must 
not  merely  be  hung  from  the  chains,  but  be  rendered  stiff,  to  resist  the  undulatory  mo- 
tion caused  by  the  wind.  See  Minutes  of  Proceedings  of  the  Institution  of  Civil  Engi- 
neers, Feb.  16,  1841,  on  this  subject 

SWEEP- WASHER,  is  the  person  who  extracts  from  the  sweeping,  potsherds,  Ac,  of 
refineries  of  silver  and  gold,  the  small  residuum  of  precious  metal. 

SYNTHESIS,  is  a  Greek  word,  which  signifies  combination,  and  is  applied  to  the 
chemical  action  which  unites  dissimilar  bodies  into  a  uniform  compound ;  as  sulphurio 
acid  and  lime  into  gypsum  ;  or  chlorine  and  sodium  into  culinary  salt 

SYRUP,  is  a  solution  of  sugar  in  water.  Cane-juice,  concentrated  to  a  density  of 
1*800,  forms  a  syrup  which  does  not  ferment  in  the  transport  home  from  the  West 
Indies,  and  may  be  boiled  and  refined  at  one  step  into  superior  sugar-loaves,  with  emi- 
nent advantage  to  the  planter,  the  refiner,  and  the  revenue. 

Syrup,  juration  of,  through  beds  of  bone  black,  has  been  prescribed  as  follows  by 
Messrs  Greenwood  and  Parker.   Suppose  5  filter  beds,  Nos.  1,  2,  8,  4,  5,  to  be  in  action, 


TANNIN,  PREPARATION  OF. 


805 


of  which  Na  1  has  been  longest  in  use ;  No.  2  the  next  longest,  and  so  on.  As  soon 
as  No.  1  has  become  too  impure  to  be  used  any  longer,  it  is  thrown  out  of  action,  No.  2 
becomes  the  first  of  the  series,  and  No.  6  is  brought  into  use  as  the  last  of  the  seriea 
The  process  of  filtration  goes  on  until  No.  2  becomes  too  impure  to  be  longer  employed ; 
it  is  then  thrown  out  of  action,  and  No.  3  becomes  the  first  in  the  series;  and  No.  1 
(which  has  been  supplied  with  fresh  filtering  materials  in  the  meanwhile)  is  brought 
into  use  as  the  last  of  the  series.  The  several  filter  beds  are  connected  together  by  pipes 
(provided  with  stopcocks),  in  such  a  manner  that  the  filtered  syrup  will  pass  from  the 
lower  part  of  No.  1  into  the  upper  part  of  Na  2,  and  from  the  lower  part  of  No.  2 
into  the  upper  part  of  No.  3,  and  so  on. 


T. 


TABBYING,  or  WATERING,  is  the  process  of  giving  stuffs  a  wavy  appearance 
with  the  calender. 

TACAMAHAC  is  a  resin  obtained  from  the  Fagura  octandra,  a  tree  which  grows  in 
Mexico  and  the  West  Indies.  It  occurs  in  yellowish  pieces,  of  a  strong  smell,  and  a 
bitterish  aromatic  taste.    That  from  the  island  of  Madagascar  has  a  greenish  tint. 

TAFFETA  is  a  light  silk  fabric,  with  a  considerable  lustre  or  gloss. 

TAFIA  is  a  variety  of  rum. 

TALC  is  a  mineral  genus,  which  is  divided  into  two  species,  the  common  and  the 
indurated.  The  first  occurs  massive,  disseminated  in  plates,  imitative,  or  crystallized  in 
small  six-sided  tables.  It  is  splendent,  pearly,  or  semi-metallic,  translucent,  flexible,  but 
not  elastic.  It  yields  to  the  nail ;  spec.  grav.  2*77.  Before  the  blowpipe,  it  first  whitens 
and  then  fuses  into  an  enamel  globule.  It  consists  of— silica,  62 ;  magnesia,  27 ;  alu- 
mina, 1'5;  oxyde  of  iron,  3*5;  water,  6.  Klaproth  found  2|  per  cent,  of  potash  in  it. 
It  is  found  in  beds  of  clay-slate  and  mica  slate,  in  Aberdeenshire,  Banffshire,  Perthshire, 
Salzburg,  the  Tyrol,  and  St.  Gothard.  It  is  an  ingredient  in  rouge  for  the  toilette,  com> 
municating  softness  to  the  skin.  It  gives  the  flesh  polish  to  soft  alabaster  figures,  and  is 
also  used  in  porcelain  paste. 

The  second  species,  or  talc-slate,  has  a  greenish-gray  color ;  is  massive,  with  tabular 
fragments,  translucent  on  the  edges,  soft,  with  a  white  streak ;  easily  cut  or  broken,  but 
is  not  flexible  ;  and  has  a  greasy  feel.  It  occurs  in  the  same  localities  as  the  preceding. 
It  is  employed  in  the  porcelain  and  crayon  manufactures ;  as  also  as  a  crayon  itself,  by 
carpenters,  tailors,  and  glaziers. 

TALLOW  (Suify  Fr. ;  Talgj  Germ.)  is  the  concrete  fat  of  quadrupeds  and  man. 
That  of  the  ox  consists  of  76  parts  of  stearine,  and  24  of  oleine;  that  of  the  sheep 
contains  somewhat  more  stearine.     See  Fat  and  Stearine. 

Tallow  imported  into  the  United  Kingdom,  in  1836,  1,186,364  cwts.  1  qr.  4  lbs.;  m 
1837,  1,308,734  cwts.  1  qr.  4  lbs.  Retained  for  home  consumption,  in  1836,  1,318,678 
cwts.  1  qr.  25  lbs. ;  in  1837,  1,294,009  cwts.  2  qrs.  21  lbs.  Duty  received,  in  1836, 
£208,284 ;  in  1837,  £204,377. 

TALLOW,  PINEY.     See  Piney  Tallow. 

TAMPING  is  a  term  used  by  miners  to  express  the  filling  up  of  the  hole  which  they 
have  bored  in  a  rock,  for  the  purpose  of  blasting  it  with  gunpowder.     See  Mines. 

TAN,  or  TANNIC  ACID.  (Tannin^  Fr. ;  Gerbstoff,  (Germ.)  See  its  preparation  and 
properties  described  under  Galls. 

The  barks  replete  with  this  principle  should  be  stripped  with  hatchets  and  bills,  from 
the  trunk  and  branches  of  trees,  not  less  than  30  years  of  age,  in  sprine,  when  their  sap 
flows  most  freely.  Trees  are  also  sometimes  barked  in  autumn,  and  left  standing,  whereby 
they  cease  to  vegetate,  and  perish  ere  long ;  but  afford,  it  is  thought,  a  more  compact 
timber.  This  operation  is,  however,  too  troublesome  to  be  generally  practised,  and 
therefore  the  bark  is  commonly  obtained  from  felled  trees ;  and  it  is  richer  in  tannia 
Ibe  older  they  are.  The  bark  mill  is  described  in  Gregory's  Mechanics,  and  other  similai 
Vorks. 

TANNIN,  PREPARATION  OF.     The  substance  from  which  tannin  is  most  fre- 

?uently  obtained  is  nutgalls,  of  which  it  constitutes  about  40  per  cent  of  their  weight 
t  may  be  procured  also  from  several  other  sources,  such  as  oak,  horse  chestnut,  sumach, 
and  cinchona  barks,  catechu,  kino,  <fec.  Tannin  obtained  from  these  different  sources, 
however,  differs  materially  in  some  of  its  characters.  The  tannin  of  nutgalls,  which  ia 
that  generally  employed  for  chemical  purposes,  is  sometimes  called  gallo-tannic  acid,  to 
distinguish  it  from  the  other  species.  According  to  Berzelius,  nutgalls  yield,  besides 
pure  tannin,  a  small  quantity  of  gallic  acid,  tannates  of  potash  and  of  lime,  modified 
tannin  in  the  state  which  is  generally  designated  by  the  name  extractive,  and  lastly,  a 
combination  of  tannin  with,  probably,  pectic  acid,  which  combination  is  insoluble  in 
cold  water,  and  is  met  with  particularly  in  the  extract  of  o^  bark. 


806 


TANNIN,  PREPARATION  OF. 


A 


The  following  Table  shows  the  quantity  of  extractive  matter  and  tan  in  100  parts  ol 
the  several  substances : — 


Substances. 

t. 
it 

00  ac 

*Mf£ 

1* 

100  parts,  by 
det  de  Gassin- 
court. 

Substances. 

d 

L 
1- 

1  100  parts,  l»y 
idet  de  Gaasln- 
court. 

d 
78 

* 

d 

White  inner  bark  of  old  oak 

.. 

21 

Bark  of  Cherry-tree 

59 

24 

Do.  young:  oak  -        -        - 

77 

Do.  Sallow  -        .        -        - 

— 

59 

Do.  Spanish  chestnut 

63 

30 

Do.  Poplar - 

— 

76 

Do.  Leicester  willow 

79 

Do.  Hazel           -       -        - 

— 

79 

Colored  or  middle  bark  of    ) 
oak        -        -        -          ) 

19 

Do.  Ash      -        -        -        - 

— 

82 

Do.  trunk  of  Span,  chestnut 

— 

98 

Do.  Spanish  chestnut 

14 

Do.  Smooth  oak  -        -        - 

— 

104 

Do.  Leicester  willow 

16 

Do.  Oak,  cui  in  spring 

— 

108 

Entire  bark  of  oak 

29 

Root  of  Tonnentil  -        -        - 

— 

46 

Do.  Spanish  chestnut 

21 

Curnus  sauguinea  of  Canada 

— 

44 

Do.  Leicester  willow 

33 

109 

Bark  of  Alder 

— 

36 

Po.  Elm    -        -        -        - 

13 

28 

Do.  Apricot 

— 

32 

Do.  Common  willow  - 

11 

boughs,  31 

Do.  Pomegranate 

— 

32 

Sicilian  snraach   -        -        - 

78 

158 

Do.  Cornish  cherry-tree 

— 

19 

Malaga  sumach    -        -        - 

79 

Do.  Weeping  willow  - 

— 

16 

Souchong  tea       -        -        - 

48 

Do.  Bohemian  olive     - 

— 

14 

Green  tea     -        -        -        - 

41 

Do.  Tan  shrub  with  myrtle  | 
leaves         -        -         ) 

13 

Bombay  catechu  -        -        - 

361 

Bengal  catechu    -        -        - 

231 

Do.  Virginian  sumach 

— 

10 

Nut-galls      .        -        -        - 

127 

- 

46 

Do.  Green  oak    -        -        - 

— 

10 

Bark  of  oak,  cut  in  winter  - 

— 

30 

Do.  Service-tree - 

— 

8 

Do.  beech  -        -        -        - 

.  II 

31 

Do.  Rose  chestnut  of  Amer. 

— 

8 

Do.  Elder .       -        -       - 

«^ 

41 

Do.  Rose  chestnut 

— 

6 

Do.  Plum-tree   -        -        - 

— 

58 

Do.  Rose  chestnut  of  Caro-  ) 
lina    -        -        -         j 

6 

Bark  of  the  trunk  of  willow  - 

-_ 

52 

16 

Do.  Sycamore    -         -         - 
Bark  of  Birch 

— 

53 

Do.  Sumach  of  Carolina      - 

— 

5 

— 

54 

Tannin  when  in  solution  attracts  oxygen  from  the  atmosphere,  and  speedily  under- 
goes a  change.  Gallo-tannic  acid  is  by  this  means  converted  into  gallic  acid,  water,  and 
carbonic  acid;  but  it  is  probable  that  a  change  of  a  different  nature  takes  place  with 
some  of  the  other  species  of  tannin,  such  as  kino. 

The  following  is  the  method  proposed  by  Berzelius/or  the  purijication  of  tannin  voiih 

sulphuric  acid.  ,  .»       a     i  t.     • 

To  a  hot  infusion  of  nutgalls  in  water,  add  a  very  small  quantity  of  diluted  sulphuric 
acid,  and  well  shake  the  mixture ;  a  flocculent  coagulum  will  be  formed,  containing 
tannin  and  extractive,  and  which  in  separating  carries  with  it  any  impurities  present^  in 
the  same  mannner  as  in  clarifying  with  white  of  eggs.  Pass  the  fluid  through  a  filter, 
and  now  add  sulphuric  acid  mixed  with  its  own  weight  of  water,  in  small  quantities  at 
a  time,  until  the  precipitate,  after  standing  for  an  hour,  is  found  to  form  a  semi-fluid 
glutinous  mass.  As  soon  as  this  change  is  found  to  have  been  effected,  decant  the  liquid, 
and  mix  with  care  concentrated  sulphuric  acid  until  no  further  precipitate  is  formed; 
a  yellowish  white  mass  is  thus  obtained,  which  is  a  combination  of  sulphuric  acid  and 
tannin,  and  is  insoluble  in  acidulated  water.  This  must  be  put  on  a  filter ;  washed  with 
water  mixed  with  a  good  deal  of  sulphuric  acid ;  jjressed  between  the  filtering  paper, 
and  afterward  dissolved  in  pure  water,  with  which  it  immediately  forms  a  pale  yellow 
solution.  To  the  solution  thus  obtained,  carbonate  of  lead  in  very  fine  powder  is  to  be 
added  in  very  small  proportions,  so  as  to  saturate  first  the  excess  of  acid,  and  after- 
wards, by  allowing  it  to  macerate  for  a  short  time,  that  portion  of  acid  combined  with 
the  tannin.  When  the  saturation  is  complete,  the  color  will  become  of  a  more  de- 
cided yellow.  The  solution  must  now  be  filtered,  and  evaporated  to  dryness.  The 
evaporation  ought  to  be  conducted  in  vacuo.  The  hard  mass  thus  obtained  will  con- 
sist of  tannin  with  a  portion  of  extractive  formed  by  the  access  of  the  air.  This  mass 
being  powdered  is  to  be  digested  with  ether,  at  a  temperature  of  86^  Fahr.,  until  noth- 
ing more  is  taken  up  by  the  menstruum  ;  the  ether  is  then  allowed  to  evaporate  spon- 
taneously, and  the  tannin  remains  in  the  form  of  a  transparent  mass,  slightly  yellow, 
which  does  not  change  by  contact  with  the  air.  That  which  remains  undissolved  by 
the  ether  is  a  brown  extractive,  not  entirely  soluble  in  water. 

Berzelius  also  gives  the  following  process  for  the  purificcdion  of  tannin  by  means  of 

1o  a  filtered  infusion  of  nutgalls,  add  a  concentrated  solution  of  carbonate  of  potash, 
BO  as  to  form  a  white  precipitate;  but  too  much  potash  must  not  be  added,  as  the  pre- 
cipitate is  soluble  in  excess  of  the  alkah*.  The  precipitate,  placed  on  a  filter,  is  to  be 
wadied  with  ice-cold  vMUr,  ajod  afterwards  dissolved  in  diluted  acetic  acid,  when  sepa- 


TANNIN,  PREPARATION  OF. 


Wl 


rtlteft  a  bf own  extractive  matter,  formed  by  the  action  of  the  air  dnring  the  previont 
washing.  Having  filtered  the  solution,  precipitate  the  tannin  by  means  of  acetate  of 
lead,  wash  the  precipitate,  and  decompose  it  with  hydro-sulphuric  acid.  Tlie  tannin 
will  now  form  a  colorless  solution  with  water,  and  may  be  obtained  in  hard  scales  on  the 
evaporation  of  the  water  in  vacuo  over  potassa.  Any  extractive  retained  in  this  tannin 
may  be  separated  by  dissolving  it  in  ether,  and  allowing  the  ether  to  evaporate  spontft- 
neously. 

A  French  pharmacien  has  observed,  that  sulphuret  of  mercury  has  the  property  ol 
decolorizing  tannin,  acting  in  the  same  way  as  powdered  charcoal  does  on  some 
substances. 

Pelouze's  process  for  the  preparation  of  tannin  is  much  more  simple  than  either  of  tli« 
foregoing;  it  is  also  more  productive.  It  consists  in  treating  nutgalls  with  ether,  by  the 
process  of  percolation.  A  displacement  apparatus  of  proper  size  being  provided,  the 
galls  in  fine  powder  are  introduced,  so  that,  when  slightly  compressed,  the  apparatus 
shall  be  one  half  filled ;  sulphuric  ether  of  commerce  is  now  to  be  added,  until  the  appa- 
ratus is  full ;  the  top  of  the  apparatus  should  be  partially  closed,  so  as  to  prevent  the 
evaporation  of  the  ether,  while  the  access  of  air  is  admitted.  Thus  arranged,  the 
apparatus  is  allowed  to  remain  for  24  hours,  by  which  period  there  will  be  found  in 
the  receiver  two  liquids,  one  floating  on  the  surface  of  the  other.  The  lighter  of  those 
will  be  perfectly  fluid,  and  but  slightly  colored,  while  that  forming  the  denser  stratum 
will  be  thick  and  syrupy,  and  of  a  light  amber  color.  More  ether  is  to  be  passed 
through  the  galls  as  long  as  the  separation  of  the  percolated  liquor  takes  place.  The 
two  fluids  are  now  to  be  separated  by  means  of  a  funnel.  The  heavier  fluid,  which 
contains  the  tannin,  is  to  be  repeatedly  washed  with  sulphuric  ether,  and,  being  put 
into  a  porcelain  cap.sule,  is  to  be  submitted  to  heat  in  a  stove  or  other  suitable  apparatus. 
The  vapors  of  ether  and  of  water  will  be  disengaged;  the  substance  contained  in 
the  capsule  will  be  considerably  augmented  in  volume,  and  a  spongy  residue  will  be 
left,  having  a  brilliant  crystalline  appearance.  This  is  sometimes  colorless,  but  more 
frequently  of  a  light  yellow  color. 

The  light  fluid  which  has  been  separated  from  the  other  may  be  distilled  for  the  re- 
covery of  the  ether,  of  which  it  principally  consists. 

When,  in  the  above  process,  the  nutgalls  are  perfectly  dry,  and  pure  anhydrous  ether 
is  substituted  for  the  ether  of  commerce,  which  contains  about  JL  its  weight  of  water,  no 
tannin  is  obtained ;  and  when,  on  the  other  hand,  dry  tannin  is  put  into  ether  which  has 
been  distilled  from  chloride  of  calcium,  only  a  very  small  quantity  is  dissolved,  the  re- 
mainder falling  down  in  the  form  of  powder ;  although,  if  the  ether  of  commerce  be  used, 
a  dense  solution  will  be  formed  in  a  few  minutes,  which  will  separate  to  the  bottom  of 
the  vessel  in  the  same  manner  as  the  solution  obtained  from  the  galls  by  displacement 

Pelouze  infers  from  these  facts,  that  of  all  the  constituents  of  the  nutgalls,  the  tannin 
is  that  which  has  the  strongest  affinity  for  water,  while  it  is  best  soluble  in  ether ;  and  on 
this  account  it  separates  the  water  contained  in  the  ether  of  commerce,  together  with  a 
small  quantity  of  ether,  forming  with  these  the  syrupy  fluid  alluded  to.  The  gallic  acid, 
and  some  other  constituents  of  the  galls,  are  held  in  solution  by  the  ether,  so  that  th« 
tannin  obtained  by  this  process  is  very  pure. 

Pelouze  made  a  great  number  of  attempts  to  obtain  tannin  in  the  crystalline  form; 
but  after  using  various  solvents  for  this  purpose,  and  experimenting  with  the  greatest 
care,  his  efforts  proved  unsuccessfuL  Examined  by  the  microscope,  tannin  presents  the 
appearance  of  a  perfectly  homogeneous  body. 

To  prepare  tannin,  take,  as  in  the  usual  way,  equal  weights  of  nut  galls  and  of  ether. 
Expose  these  two  substances  in  a  glass  or  stoneware  vessel  to  a  temperature  of  15°  or 
20*-*  C. ;  after  macerating  for  one  month,  the  mixture  having  become  a  somewhat  solid 
paste,  place  it  in  a  strong  cloth,  and  submit  it  to  pressure.  TTie  product  obtained  will 
De  of  the  consistence  of  molasses,  very  adhesive  to  the  touch,  and  does  not  disengage  any 
portion  of  the  ether  which  it  contains  at  ordinary  temperatures.  I^  having  placed  this 
mixture  in  an  open  vessel,  we  expose  it  to  the  sun,  or  in  a  stove,  at  the  end  of  some  time 
we  shall  perceive  the  surface  to  become  covered  with  efliorescence,  whilst  the  rest  of 
the  mass  maintains  the  appearance  of  a  thick  honey-like  fluid  for  more  than  six  montha 

To  obviate  this  inconvenience,  which  retards  the  preparation  of  tannin,  and  affects  its 
purity,  by  the  deposition  of  foreign  bodies  contained  in  the  atmosphere,  it  is  necessarr 
to  submit  the  mixture  to  the  action  of  an  elevated  temperature  of  at  least  120°  C.  This 
temperature  may  be  obtained  in  a  very  fixed  manner,  by  means  of  a  concentrated  solution 
of  chloride  of  calcium.  The  choride  of  calcium  thus  forms  an  excellent  salt  water  bath, 
of  very  great  service  in  many  chemical  preparations. 

The  apparatus  most  in  use  is  composed,  1st,  of  an  iron  boiler,  containing  the 
muriate  of  lime ;  2d,  of  a  flat-bottomed  silver  basin  (one  of  copper  will  answer,  if  well 
tinned),  into  which  the  tannin  is  to  be  placed.  This  latter  is  to  be  placed  in  the  muriate 
of  lime,  which  is  to  be  raised  to  the  boiling  temperature.    But  to  obtain  a  temperature 


808 


TAPESTRY. 


of  120°  C.  without  burning  the  product^  it  is  necessary  to  toke  some  precautions  which 
Will  readily  be  foreseen.  ^ 

Having  arranged  the  apparatus  with  suitable  precautions,  and  having  cautiously  set 

it'?  fP^""-^  m',^  i??""^'*"^  ^'m.^^®  ®^^^''  ^**^^^  preserves  the  tannin  iS  the  stat*  of  a 
thick  liquid  will  readily  volatilize,  and  the  inferior  part  of  the  mass  touching  the  basin 
wil  be  converted  into  brilliant,  nearly  white,  very  light  scales,  forming  a  masTof  greatei 
bulk  than  before.  Meanwhile  the  upper  portion  remains  colored  and  transparent 
because  it  contains  a  larger  quantity  of  the  ether,  which  cannot  be  driven  off  the  heat 
not  penetrating  with  sufficient  power  to  this  part  It  is  in  this  state  that  we  find  the 
tannin  in  commerce  But  to  render  it  white  and  light  throughout  the  whole  mass,  it  is 
proper  to  cover  the  basiu  with  a  plate  of  copper,  on  which  some  red-hot  coals  ar^o  be 
placed;  then  the  phenomenon  indicated  above  will  be  perceived  to  take  place,  namelv 
the  part  remaining  colored  and  transparent  will  increase  in  bulk,  and  become  changed 
^^^I^lji^n\7>^'^^  ''S^^''  ^  ^*^  l»appened  in  tlie  portion  touching  the  basin  itself. 

TANNING  (banner,  Fr.;  G drberei,  Germ.)  is  the  art  of  converting  skin  into  Lkathkr 
which  see.     It  has  been  ascertained,  beyond  a  doubt,  that  "  the  saturated  infusions  of 
astringent  harks  contain  much  less  extractive  matter,  in  proportion  to  their  tannin,  than 
the  weak  infusions;  and  when  skin  is  quickly  tanned  (in  the  former),  cowmon  expe- 
nence  shows  that  it  produces  leather  less  durable  than  leather  slowly  formed."*    The 
older  tanners  who  prided  themselves  on  producing  a  substantial  article,  were  so  much 
impressed  with  the  advantages  of  slowly  impre-natin?  skin  with  astringent  matter,  that 
they  employed  no  concentrated  infusion  (ooze)  in  their  pits,  but  stratified  the  skins  with 
abundance  of  ground  bark,  and  covered  them  with  soft  water,  knowing  that  its  active 
principles  are  very  soluble,  and  that,  by  being  gradually  extracted,  they  would  penetrate 
uniformly  the  whole  of  the  animal  fibres,  instead  of  acting  chiefly  upon  the  surface,  and 
making  brittle  leather,  as  the  strong  infusions  never  fail  to  do.     In  fact,  100  pounds  of 
«kin,  quickly  tanned  in  a  strong  infusion  of  bark,  produce  137  of  leather  •  while  100 
pounds,  slowly  tanned  in  a  weak  infusion,  produce  only  1 17|.    The  additional'l9*  pounds 
weight  in  the  former  case  serve  merely  to  swell  the  tanner's  bill,  while  they  deteriorate 
his  leather,  and  cause  it  to  contain  much  less  of  the  textile  animal  solid.     Leather  thu« 
highly  charged  with  tannin  is,  moreover,  so  spongy  as  to  allow  moisture  to  pass  readilr 
through  Its  pores,  to  the  great  discomfort  and  danger  of  persons  who  wear  shoes  made 
uT    -^^^  ^^^*""  of  time,  and  the  increase  of  product,  are  temptations  strong 
enough  to  induce  many  modern  tanners  to  steep  their  skins  in  a  succession  of  stron-  irJ 
fusions  of  bark,  is  sufficiently  intelligible;  but  that  any  shoemaker  should  he  so  i?nomnl 
or  so  foolish  as  to  proclaim  that  his  leather  is  made  by  a  process  so  injurious  to  its 
quality,  is  unaccountably  stupid.  j     "u.  lo  w 

TANTALUM  is  the  rare  metal,  also  called  Columbium. 

TAPESTRY  is  an  ornamental  figured  textile  fabric  of  worsted  or  silk,  for  lining  the 
walls  of  apartments ;  of  which  the  most  famous  is  that  of  the  Gobelins  Royal  Manufao- 
iory)  iiccLr  i  siris* 

TAPESTRY  AND  LACE.  Some  of  the  objects  included  in  this  claes  in  the  Exhi- 
bition  presented,  from  their  remarkable  disposition  in  the  building,  a  highly  attractive 
and  interesting  appearance,  suspended  from  the  girders  over  the  galleries,  and  thus  dis- 
played to  the  best  advantage,  and  under  circumstances  the  most  highly  calculated  to 
develop  their  peculiar  beauties;  the  specimens  of  carpets,  oil-cloths,  and  tapestry, 
must  be  considered  as  having  occupied  a  very  prominent  space  in  the  Exhibition^ 

The  following  sub-classes  had  a  place  under  the  general  classes,  inclusive  of  these  and 
other  articles :  A,  tapestry,  as  carpets  of  all  kinds,  Axminster,  Brussels,  Kidderminster, 
&c,  matting,  oi  -cloth,  counterpanes,  and  ornamental  tapestry  of  different  materials;  B 
lace  as  pillow-  ace,  made  wholly  by  hand,  and  machine-wrought  lace;  C,  sewed  and 
temboured  muslins ;  D,  embroidery  by  hand  and  machinery,  and  in  different  materials; 
£,  fringes,  tassels,  <fec. ;  F,  fancy  and  industrial  works. 

The  manufacture  of  tapestry,  such  as  carpets,  oil-cloths,  and  lace,  is  localized  in 
peculiar  districts,  m  a  remarkable  manner;  Kidderminster,  Wilton,  Glasgow  and 
Halifa>^  contain  extensive  factories  solely  engaged  in  the  production  of  the  various 
descriptions  of  carpets  in  ordinary  domestic  use.  The  application  of  the  power-loom  to 
the  carpet  manufacture  is  recent,  and  its  use  is  extending.  A  great  variety  of  combina- 
tion  of  materials  was  exhibited,  many  of  which  indicated  a  remarkable  departure  from 
the  ordinary  method  of  manufacturing  carpets  and  similar  objects.  One  of  these  was  a 
species  of  mosaic  tapestry,  where  the  cut  wool  was  fixed  to  a  ground  or  foundation  of 
caoutchouc.  ° 

The  lace  productions  of  Honiton  and  Buckinghamshire  have  long  attained  universal 
renown.  These  laces  are  chiefly  wrought  by  hand  at  the  houses  of  the  persons  concerned 
in  their  manufacture ;  but  recently  a  combination  of  machine-made  lace  and  pillow-made 

*  Sir  H.  Davy,  on  the  Operation  of  Aatringent  Vegetables  in  Tanning.-PAiZ.  Trans.  1803. 


TAR  (COAL). 


809 


(jmament  has  been  introduced,  under  the  title  of  "appliqu^e  lace."  The  machine  lace 
of  Nottingham  has  scarcely  an  inferior  degree  of  celebrity :  in  that  town  factories  are 
in  almost  constant  work,  producing  by  the  aid  of  a  large  number  of  the  most  delicate 
and  costly  automatic  engines  this  splendid  fabric.  In  a  preceding  class  these  machines 
were  described,  and  were  exhibited  in  motion  in  another  part  of  the  building.  In  the 
south  central  gallery  were  some  beautiful  specimens  of  the  intricate  and  elegant  orna- 
mentation capable  of  being  imparted  by  these  machines.  Of  the  lace  made  bv  hand 
various  interesting  specimens  were  shown,  which  represented  much  patient  e&brt  in 
the  instruction  of  the  poor  in  this  art  and  considerable  taste  in  design. 

Few  departments  of  ornamental  industry  have  experienced  so  many  vicissitudes,  in 
consequence  of  the  introduction  of  mechanical  power,  as  that  of  the  lace  manufacture. 
The  lace  of  Honiton  in  Devon  has  long  rivalled  the  most  beautiful  and  costly  produc- 
tions of  the  continent  At  one  period  during  the  last  war,  veils  of  Honiton  lace 
sold  for  very  large  sums,  as  much  as  100  guineas  having  been  paid  for  fine  specimens: 
Honiton  lace  is  entirely  made  on  the  pillow  by  hand  labor. 
^^  The  application  of  machinery  to  the  production  of  lace  is  very  remarkable  and 
interesting,  as  probably  few  introductions  of  machinery  to  textile  manufactures  pro- 
duced so  sudden  an  alteration  on  the  expiration  of  the  patent  protecting  it,  in  the  or- 
dinary course  of  fabrication.  The  bobbin-net  machine  was  invented  in  1809;  it 
came  into  general  use  in  1823,  and  an  immense  stimulus  was  communicated  to  the 
manufacture.  The  power  of  production  of  this  machine  are  to  hand  labor  nearly  as 
80,000  to  6,  and  the  lace  production  by  it  has,  in  plain  articles,  wholly  superseded  that 
made  by  hand.    See  Bobbinet. 

TAPIOCA,  is  a  modification  of  starch,  partially  converted  into  gum,  by  heating  and 
stirring  cassava  upon  iron  platea     See  Cassava  andi  Starch. 

TAR  of  ioood{Goitdron.;  Fr. ;  Ther,  Germ.);  is  the  viscid,  brown-black,  resino-oleagi- 
nous  compound,  obtained  by  distilling  wood  in  close  vessels,  or  in  ovens  of  a  peculiar  con- 
struction. See  Charcoal,  PrrcoAL,  coking  of,  and  Ptrolignous  Acid.  According  to 
Reichenbach,  tar  contains  the  peculiar  proximate  principles,  parajine,  eupion,  creosote^ 
picamar,  pittacall,  besides  pyrogenous  resin,  or  pi/retine,  pryogenous  oil,  or pyroleiiie,  and 
yinegar.     The  resin,  oil,  and  vinegar  are  called  empyreumatic,  in  common  language. 

TAR  (COAL).  There  is  not  perhaps  any  waste  article  of  our  manufacturing  indus- 
try which  has  been  so  singularly  neglected  as  coal-tar,  and  yet  there  can  be  but  veiy 
few  which  offer  anything  like  so  fair  a  field  of  remuneration  for  the  exercise  of  skiU 
and  ingenuity.  To  begin :  the  article  has  hitherto  been,  and  still  in  great  measure  con- 
tinues, entirely  valueless;  it  has  in  fact  only  a  nominal  price  in  the  market,  as  is  evi- 
denced by  the  circumstance  that  it  is  consumed  as  fuel  at  many  of  our  large  metropoli- 
tan gas  works,  and  at  others  is  sold  as  low  as  at  the  rate  of  one  penny  for  6  gallons. 
This  latter  is  however  far  from  its  real  value  even  as  fuel,  for  it  has  been  found  in  prac- 
tice that  the  average  heating  power  of  tar,  as  compared  with  coke,  upon  a  long  series 
of  workings,  is  as  more  than  two  to  one,  or  in  other  words  that  a  gallon  of  tar  weigh- 
ing about  10|  lbs.  affords  as  much  heat  as  half  a  bushel  or  22  lbs.  of  coke,  and  this  too 
although  the  tar  contains  about  one  pound  of  water  entangled  in  its  substance  or  chemi- 
cally combined,  so  as  not  to  be  separable  by  long  standing.  As  we  have  before  said, 
the  tar  thus  adulterated  with  water  is  still  equal  to  more  than  double  its  weight  of  good 
coke  as  a  heating  agent,  when  tested  upon  a  large  working  scale  for  many  months  in 
succession.  This  fact  ought  to  convince  us,  if  any  doubt  yet  remains,  of  the  folly  and  ig- 
norance of  those  persons  who  assert  that  the  value  of  coal  as  a  calorific  substance  de- 
pends solely  upon  the  amount  of  carbon  or  coke  which  it  contains,  and  is  in  no  way 
proportioned  to  or  affected  by  the  quantity  of  its  tarry  or  volatile  products.  The  truth 
would  appear  to  be,  that  where  a  coal  affords  by  distillation  30  per  cent  of  these  tarry 
products,  its  heating  power  is  exactly  double  of  that  which  the  residuary  carbon  or  coke 
18  able  to  produce ;  and  this  proportion  of  volatile  to  fixed  matter  is  just  about  the  ratio 
existing  in  most  bituminous  coals,  so  that^  as  a  general  rule,  the  advocates  of  the  above 
hypothesis  are  wrong  to  the  extent  of  one  half.  The  high  heating  power  of  coal-tar 
ought  to  induce  the  managers  of  gas  works  either  to  use  it  themselves,  or,  where  this 
cannot  be  done,  to  vend  it  at  a  price  proportioned  to  its  value  in  coke ;  thus,  presuming 
a  bushel  of  coke  to  be  worth  4<i,  then  a  gallon  of  tar  as  fuel  would  be  worth  2d. ; 
whereas,  as  we  have  seen,  this  tar  has  been  sold  as  low  as  6  gallons  for  one  penny,  a 
most  convincing  proof  of  the  expensive  nature  of  ignorance  in  some  situations.  The 
arrangements  now  in  use  at  the  Equitable  Gas  Works,  Pimlico,  are  the  best  we  have 
seen,  so  far  as  regards  the  heating  of  gas  retorts. 

The  consumption  of  tar  as  fuel  is,  however,  after  all,  but  a  barbarous  misapplication  of 
ingenuity,  and  far  beneath  the  intelligence  of  the  age.  This  substance,  when  properly 
distilled,  is  capable  of  yielding  naphtha,  a  fixed  oil,  and  pitch,  the  two  former  of  which 
are  vastly  more  valuable  than  tar.  The  relative  proportion  of  these  products  is,  however, 
very  variable  according  to  the  kind  and  quality  of  the  tar  employed.    Thus  tar  from 


I 


F 


f; 


« 


fl 


M 
f  I 


u 


I 


m^ 


TARTAR. 


Naphtba. 

DeadoU. 

Pitch 

8 

62 

86 

9 

60 

81 

16 

67 

18 

^e  oondenser  is  more  valuable  for  its  products  than  tlie  tar  of  the  same  coal  taken 
from  the  hydraulic  maiD,  and  again  canuel  coal  tar  is  always  superior  to  common  coal- 
tar.  In  general  we  may  estimate  the  available  amount  of  the  volatile  and  fixed  mat- 
tars  of  cool  somewhat  in  the  following  order. 

Common  coal  tar 
Ordinary  cannel  tar 
Boghead  cannel  tar 

Of  these  the  naphtha  is  in  large  demand  for  the  solution  of  caoutchouc,  the  lighting 
of  lamps,  and  other  purposes.  The  dead  oil  contains  paraffine,  and  is  an  excellent 
lubricator  for  machinery :  the  uses  of  pitch  need  not  be  enumerated.  At  the  present 
time  this  kind  of  naphtha  reaches  about  U  6d.  per  gallon,  and  the  dead  oil  from  8(i  to 
90.  per  gallon,  so  that  a  more  profitable  form  of  manufacture  can  scarcely  be  desired. 
1^  mode  of  working  up  these  substances  from  the  crude  tar  is  by  no  means  either 
difficult  or  expensive.  In  the  first  instance  the  oU  is  run  into  a  vessel  like  a  common 
steam  boiler,  and  to  which  a  common  condenser  or  worm  is  connected ;  fire  is  then 
opphed,  and  the  process  of  distiUation  carried  on  till  all  the  naphtha  has  passed  over 
which  IS  known  by  the  cessation  of  the  fluid  flowing  from  the  worm;  after  this  the 
heat  18  raised  considerably,  and  another  receiver  applied,  when  a  less  volatile  fluid 
makes  Its  appearance,  which  is  the  dead  oil,  and  which  continues  to  flow  until  smoke 
issues  from  the  worm,  when  the  operation  is  finished  by  running  the  pitch  out  of  the 
boUer,  so  as  to  be  ready  for  another  operation.  The  naphtha  is  now  to  be  mixed  with 
about  10  per  cent  by  bulk  of  concentrated  sulphuric  acid,  and  when  the  mixture  is 
cool,  peroxide  of  manganese  should  be  stirred  in  to  the  extent  of  half  the  weight  of  the 
SulDhunc  acid  previously  employed,  after  which  the  naphtha  must  be  decanted  off  and 
re-distilled  with  care,  so  as  to  become  colorless,  and  of  a  specific  gravity  of  about  -850 
Pu  ^^^^^^^  ^^  commonly  sent  into  the  market  in  its  crude  state,  but  this  is  a  practice 
to  be  condemned.  The  best  way  is  to  treat  it  in  the  same  manner  as  the  naphtha  with 
sulphuric  acid,  and  peroxide  of  manganese,  after  which  it  should  be  boiled  with  a  por- 
tion  of  caustic  soda  lye,  and  when  the  oil  has  risen  to  the  surface  by  standing,  it  should 
be  decanted  carefully  and  distilled  gradually,  first  rejecting  the  watery  portions  which 
nse  in  the  beginning  of  the  operation. 

xu^^l^  Boghead  cannel  coal  has  been  used  for  the  production  of  the  tar,  the  dead  oil 
then  obtained  contains  a  portion  of  paraffine,  which  crystallizes  in  the  dead  oil  tern- 
l)erature  below  50°  Fahr.  In  this  state  it  may  be  collected  by  filtration,  and  pu- 
nfied  from  adhering  oil  by  pressure,  when  it  may  be  boiled  with  about  8  per  cent  of 
Its  weight  of  highly  concentrated  oil  of  vitriol,  which  clears  and  destroys  its  impuri- 
tiea  The  paraffine  is  next  to  be  boiled  in  water,  and  suffered  to  cool  slowly  so  as  to 
deposit  the  charred  matters,  and  this  may  be  repeated  once  or  twice,  when  it  is  pure 
and  marketable.  i  t*    v 

^fT^S^APrTT^i'?)®  theUnited  Kingdom,  in  1860,  12,097  lasts;  in  1851,  16,780  lasts. 

1  AKFAULm  (from  Tar) ;  canvas  imbued  with  tar,  used  to  cover  over  the  hatch- 
ways of  a  ship  to  prevent  rain  or  sea  water  from  entering  the  hold 

TARRAS ;  see  Cement,  ana  Mortar,  hvdrauuc. 

TARTAR  (Tarlre,  Fr. ;  Weinstein,  Germ.),  called  also  argal  or  argol,  is  the  crude 
bitartrate  of  potassa,  which  exists  in  the  juice  of  the  grape,  and  is  deposited  from  wines 
in  their  fermenting  casks,  being  precipitated  in  proportion  as  the  alcohol  is  formed,  in 
consequence  of  its  insolubility  in  that  liquid.  There  are  two  sorts  of  argal  known  in 
commerce,  the  white,  and  the  red ;  the  former,  which  is  of  a  pale-pinkish  color,  is  the 
crust  let  fall  by  white  wines ;  the  latter  is  a  dark-red,  from  red  wines. 

The  crude  tartar  is  purified,  or  converted  into  cream  of  tartar,  at  Montpellier,  by  the 
following  process : —  *  r         3    ^ 

The  argal  having  been  ground  under  vertical  mill-stones,  and  sifted,  one  part  of  it  is 
boiled  with  lo  of  water,  in  conical  copper  kettles,  tinned  on  the  inside.  As  soon  as  it  is  ' 
dissolved,  35  parts  of  ground  pipe-clay  are  introduced.  The  solution  bei.ig  well  stirred, 
and  then  settled,  is  drawn  off  into  crystallizing  vessels,  to  cool ;  the  crystals  found  con- 
creted on  the  sides  and  bottom  are  picked  out,  washed  with  water,  and  dried.  The 
mother  water  is  employed  upon  a  fresh  portion  of  argal.  The  crystals  of  the  first  crop 
are  re-dissolved,  re-cryslallized,  and  exposed  upon  stretched  canvass  to  the  sun  and  air, 
to  be  bleached.  The  clay  serves  to  abstract  the  coloi.ag  matter.  The  crystals  formed 
Hpon  the  surface  are  the  whitest,  whence  the  name  cream  of  tartar  is  derived. 

Purified  tartar,  the  bitartrate  of  potassa,  is  thus  obtained  in  hard  clusters  of  small  col- 
orless crystals,  which,  examined  by  a  lens,  are  seen  to  be  transparent  4-sided  prisms.  It 
has  no  smell,  but  a  feebly  acid  taste ;  is  unchangeable  in  the  air,  has  a  specific  gravity 
of  1-953,  dissolves  in  16  parts  of  boiling  water,  and  in  200  parts  at  60°  F.  It  is  insolu- 
ble in  alcohol.    It  consists  of  24*956  potassa,  70-276  tartaric  acid,  and  4-768  water.    H 


TARTARIC  ACID. 


811 


affords,  by  dry  distillation,  pyrofcartaric  acid,  and  an  erapyreumatic  oil ;  while  carbonate 
of  potassa  remains  associated  with  much  charcoal  in  the  retort  constituting  black  flnx. 
Tartar  is  used  in  dyeing,  medicine,  and  for  extracting. 

TARTARIC  ACID,  {jicide  tartarique,  Fr. ;  Weinsteinsdure,  Germ.)  This  is  pre- 
pared by  adding  gradually  to  a  boiling-hot  solution  of  100  parts  of  tartar,  in  a  large 
copper  boiler,  26  of  chalk,  made  into  a  smooth  pap  with  water.  A  brisk  eflervescence 
ensues,  by  the  disengagement  of  the  carbonic  acid  of  the  chalk,  while  its  base  combines 
with  the  acid  excess  in  the  tartar,  and  forms  an  insoluble  precipitate  of  tartrate  of  lime. 
The  supernatant  liquor,  which  is  a  solution  of  neutral  tartrate  of  potassa,  must  be 
drawn  off  by  a  syphon,  and  decomposed  by  a  solution  of  chloride  of  calcium  (muriate 
•f  lime.)  28|  parts  of  the  dry  chloride  are  sufficient  for  100  of  tartar.  The  tartrate 
of  lime,  from  both  processes,  is  to  be  washe<l  with  water,  drained,  and  then  subjected,  in 
a  leaden  cistern,  to  the  action  of  49  parts  of  sulphuric  acid,  previously  diluted  with  8 
times  its  weight  of  water ;  100  of  dry  tartrate  take  75  of  oil  of  vitriol.  This  mixture, 
after  digestion  for  a  few  days,  is  converted  into  sulphate  of  lime  and  tartaric  acid.  The 
latter  is  to  be  separated  from  the  former  by  decantation,  filtration  through  canvass,  and 
edulcoration  of  the  sulphate  of  lime  upon  the  filter. 

The  clear  acid  is  to  be  concentrated  in  leaden  pans,  by  a  moderate  heat,  till  it  acquircar 
the  density  of  40°  B.  (spec  grav.  1-38),  and  then  it  is  run  off,  clear  from  any  sediment, 
into  leaden  or  stoneware  vessels,  which  are  set  in  a  dry  stove-room  for  it  to  crystallize. 
The  crystals,  being  re-dissolved  and  re-crystallized,  become  colorless  6-sided  prisms- 
In  decomposing  the  tartrate  of  lime,  a  very  slight  excess  of  sulphuric  acid  must  be  em 
ployed ;  because  pure  tartaric  acid  would  dissolve  any  tartrate  of  lime  that  may  escape  de 
composition.     Bone  black,  previously  freed  from  its  carbonate  and  phosphate  of  lime,  by 
muriatic  acid,  is  sometimes  employed  to  blanch  the  colored  solutions  of  the  first  crystals 
Tartaric  acid  contains  nearly  9  per  cent,  of  combined  water.     It  is  soluble  in  two  parts 
of  water  at  60*,  and  in  its  own  weight  of  boiling  water.     In  its  dry  state,  as  it  exists  u 
the  tartrate  of  lime  or  lead,  it  consists  of  36-8  of  carbon,  3  of  hydrogen,  and  60-2  of  oxy 
gen.    It  is  much  emploved  in  calico-printing,  and  for  making  sodaic  powders. 

In  consequence  of  the  great  variation  in  the  constituents  of  ai^ol  or  rough  tartar,  ths 
manufacture  of  tartaric  acid  is  not  nearly  so  simple  as  a  first  glance  at  its  several  processes 
might  lead  an  inexperienced  individual  to  suppose.  The  theory  of  preparing  tartaric 
acid  seems,  indt^ed,  a  remarkably  easy  affair;  and,  provided  the  materials  operated  upon 
were  pure  or  of  uniform  quality,  no  kind  of  manufacture  could  put  on  less  the  appear- 
ance of  risk  or  speculation.  But  too  many  know,  to  their  cost,  with  what  ready  facility 
the  whole  profit,  and  something  more,  of  a  large  operation,  will  occasionally  ooze  off 
through  a  variety  of  unknown  channels,  and  present  a  sadly  defective  and  truncated 
return  of  saleable  produce.  In  fact,  money  is  not  unfrequently  lost  in  this  manufacture 
by  very  old  and  experienced  makers.  The  differences  in  ai^ol  arise  from  the  greater 
or  smaller  amount  of  tartrate  of  lime  combined  with  the  bitartrate  of  potash ;  these 
differences  will,  in  a  commercial  way,  amount  to  from  5  to  25  or  even  80  per  cent ;  and 
herein  resides  a  difficulty,  requiring  more  analytical  skill  and  chemical  knowledge  than 
is  commonly  found  amongst  practical  manufacturers.  We  will  suppose  that  an  ai^ol 
has  been  purchased,  containing  by  analysis  70  per  cent  of  bitartrate  of  potash,  but  also, 
though  unknown  to  the  purchaser,  containing  20  per  cent  of  tartrate  of  lime.  Accord- 
ing to  t^e  process  followed,  this  argol  would  be  dosed  with  a  definite  proportion  of  chalk 
or  carbonate  of  lime,  so  as  to  produce  tartrate  of  lime  with  the  extra  tartaric  acid  of  the 
fiupertartrate  of  potash.  This  tartrate  of  lime,  being  insoluble,  would  fall  and  mingle 
with  the  20  per  cent  already  existing;  but  as  in  practice  the  quantity  of  sulphuric  acid 
employed  for  subsequent  decomposition  of  this  tartrate  of  lime  is  proportioned  to  the 
amount  of  chalk  originally  employed,  it  follows  that  the  tartrate  of  lime  naturally  present 
in  the  ai^ol  is  left  undecomposed,  and  comes  to  be  regarded  as  sulphate  of  lime,  to  the 
great  loss  of  the  manufacturer,  who  probably  finds  his  more  intelligent  neighbor  able 
to  buy  as  he  buys,  and  yet  capable  of  underselling  him  in  the  open  market  To 
illustrate  the  full  bearing  of  this  and  other  interesting  points  in  the  fabrication  of  tartaric 
acid,  it  will  be  better  to  enter  into  a  condensed  description  of  the  whole  process,  taken  on 
the  assumption  that  pure  bitartrate  of  potash  is  the  raw  material  to  be  used  in  the 
manufacture.  Having  weighed  out  a  given  proportion  of  this  substance,  it  is  to  be 
thrown  into  a  leaden  boiler,  provided  with  a  stirring  apparatus,  and  the  whole  has  some- 
times a  closely  fitting  cover  provided  with  a  pipe  for  carrying  off  and  utiliang  the  car- 
bonic acid  gas  generated,  as  we  shall  see,  during  the  first  operation.  The  bitartrate  of 
Sotash  having  been  introduced  into  this  vessel,  water  is  then  added,  and  a  quantity  of 
ried  chalk,  in  the  ratio  of  about  one  part  of  dry  chalk  to  four  of  bitartrate  of  potash, 
put  in  by  degrees.  After  boiling  and  stirring  for  some  time,  the  effervescence  due  to 
the  carbonic  acid,  arising  from  the  decomposition  of  the  chalk,  ceases ;  and  then  the 
tartrate  of  lime  is  to  be  allowed  to  subside,  that  the  clear  solution  of  tartrate  of  potash 
may  be  tested  with  litmus,  to  demonstrate  the  non-existence  of  bitartrate  of  potash  in 


;1 


812 


TEA. 


TEA. 


813 


the  fluid.    This  being  Satisfactory,  a  quantity  of  finely  powdered  sulphate  of  lime  is  now 
thrown  in,  equal  to  one  and  three  quarter  times  the  weight  of  the  dried  chalk  first 
employed,  or  rather  better  than  j ths  of  the  bitartrate  of  potash.    This  mixture  must  be 
boiled  for  a  considerable  time,  and  assiduously  stirred  until  a  little  of  the  clear  liquor, 
when  hot,  affords  no  precipitate  on  the  addition  of  a  strong  solution  of  nitrate  of  lime. 
The  decomposition  is  now  complete,  and  the  whole  of  the  tartaric  acid  will  be  found 
united  to  the  lime  as  an  insoluble  powder  (tartrate  of  lime);  whilst  the  potash,  in  the 
state  of  sulphate  exists  m  solution,  and  may  be  procured  by  evaporating  the  clear  liquor. 
After  the  insoluble  tartrate  of  lime  has  been  two  or  three  times  washed  with  warm  water 
It  18  to  be  decomposed  by  a  slight  excess  of  diluted  sulphuric  acid,  made  by  mixing 
together  oil  of  vitriol,  equal  to  2|  times  the  weight  of  the  chalk  used,  with  10  times  ito 
bulk  of  water.    In  this  way  sulphate  of  lime  is  formed,  which  is  set  aside  for  a  subse- 
quent  oj3eration,  leaving  the  tartaric  acid  with  a  trifling  excess  of  sulphuric  acid  in  the 
clear  solution     This  solution,  when  crude  tartar  has  been  employed,  has  generally  a 
brown  or  reddish-yellow  color,  and  requires  to  be  digested  for  some  hours  upon 
animal  charcoal,  to  purify  and  bleach  it    When  this  is  effected,  it  is  carefully  evaporated 
on  a  water  bath,  or  by  steam  heat,  and,  after  proper  concentration,  run  out  into  large 
cylindrical  leaden  coolers  to  crystallize.     A  second  solution,  digestion  on  animal  char- 
coal  and  recrystallization,  are  generally  needed  to  render  the  acid  white  enough  for  the 
market     From  the  above,  it  will  be  seen  that  unless  the  manufacturer  is  not  only  aware 
of  the  surplus  tartrate  of  lime  present  in  the  rough  tartar  he  buys,  but  has  also  a  toler- 
ably correct  idea  of  Its  quantity,  he  runs  a  risk,  almost  amounting  to  a  certainty,  of 
leaving  undecomposed  tartrate  of  lime  in  his  sulphate  of  lime;  and  as  this  latter  is  in 
great  part  a  waste  product^  the  two  pass  away  from  the  works  under  one  name,  as  mere 
refuse.     But  there  is  also  an  important  consideration  connected  with  the  evaporation  of 
solutions  of  tartaric  acid.    This  is  generally,  and  indeed  we  might  say  invariably,  done 
in  contact  with  atmospheric  air,  the  solution  meanwhile  containing  a  perceptible  excess 
of  sulphuric  acid ;  but,  under  such  treatment,  tartaric  acid  undergoes  decomposition 
almost  as  readily  as  sugar;  and  therefore,  like  sugar,  it  ought  to  be  operated  upon  in 
vacuo,  or,  at  least,  in  a  vessel  similar  to  a  vacuum  pan,  but  lined  with  lead,  to  prevent 
cupreous  contamination.     In  this  way,  and  by  knowing  the  exact  composition  of  the 
rough  tartar  used  in  every  instance,  the  greatest  certainty  might  ultimately  be  secured 
m  this  delicate  manufacture,  instead  of  the  conflicting  and  paradoxical  results  which 
now  annoy,  and  too  frequently  dishearten,  the  practical  operator. 

TARTRATES,  are  salts  composed  of  tartaric  acid,  and  oxidized  bases,  in  eauivalent 
proportions.  ^ 

TAWING,  is  the  process  of  preparing  the  white  skins  of  the  sheep  doe,  Ac     See 

TEA.  This  well-known  plant  has  recently  acquired  peculiar  interest  among  men 
of  science,  both  in  a  chemical  and  physiological  point  of  view.  In  its  composition  it  ap- 
proaches  by  the  quantity  of  azote  it  contains  to  animalized  matter,  and  it  seems  thereby 
qualified,  according  to  Liebig,  to  exercise  an  extraordinary  action  on  some  of  the  funo 
tions  of  animals,  especially  the  secretion  of  bile.  The  chemical  principle  characteristic 
of  tea,  coffee,  and  cocoa-beans,  is  one  and  the  same  when  equally  purified,  from  which- 
ever of  these  substances  it  is  extracted;  and  is  called  indifferently  either  theine  or 
caffeine.  Mulder  takes  it  from  tea,  by  treating  the  evaporated  extract  by  hot  water, 
with  calcined  magnesia,  filtering  the  mixture,  evaporating  to  dryness  the  liquor  which 
passes  through,  and  digesting  the  residuum  in  ether.  This  solution  being  distilled, 
the  ether  passes  over,  and  the  theine  remains  in  the  retort.  This  principle  is  extracted 
in  pe  same  war/  from  ground  raw  coffee  and  from  guarana,  a  preparation  of  the 
seeds  cfpaio.ama,  highly  valued  by  the  Brazilians.  Theine,  when  pure,  crystallizeg 
in  fine  glossy  needles,  like  white  silk,  which  lose,  at  the  heat  of  boiling  water,  8  per 
sent,  of  their  weight,  constituting  its  two  atoms  of  water  of  crystallization.  These 
needles  are  bitter  tasted.  They  melt  at  350^  F.,  and  sublime  at  543°  without  decom- 
posing.  The  crystals  dried  at  250°  dissolve  in  98  parts  of  cold  water,  97  of  alcohoL 
and  194  parts  of  ether.  In  their  ordinary  state,  they  are  but  little  more  soluble 
m  these  menstrua.  Theine  is  a  feeble  base,  and  is  precipitable  by  tannin  alone  from 
its  solution. 

Mr.  Stenhouse  prepares  theine  by  precipitating  a  decoction  of  tea  with  solutiou  of 
acetate  of  lead,  evaporating  the  filtered  liquor  to  a  dry  extract,  and  exposing  this 
extract  to  a  subliming  heat  in  a  shallow  iron  pan,  whose  mouth  is  covered  flatly  with 
porous  paper  luted  round  the  edges,  as  a  filter  to  the  vapor,  and  surmounted  with  a 
cap  of  compact  paper,  as  a  receiver  to  the  crystals.  In  this  way  he  obtained,  at  a 
maximum,  only  1-37  from  100-00  of  tea.  But  M.  Peligot,  from  the  quantity  of 
azote  amounting  to  about  6  per  cent.,  which  he  found  in  the  tea  leaves,  being  led  to 
believe  that  much  more  theine  existed  in  them  than  had  hitherto  been  obtained,  adopted 
the  following  improved  process  of  extraction.    To  the  hot  infusion  of  tea,  subacetate 


of  lead  and  then  ammonia  were  added ;  through  the  filtered  liquor  a  current  of  sul- 
phuretted hydrogen  was  passed  to  throw  down  all  the  lead,  and  die  clear  liquid  being 
evaporated  at  a  gentle  heat  afforded,  on  cooling,  an  abundant  crop  of  crystals.     By  re 
evaporation  of  the  mother  liquor,  more  crystals  were  procured,  amounting  altogether 
to  from  5  to  6  out  of  100  of  tea. 

The  composition  of  theine  may  be  represented  by  the  chemical  formula,  C*,  H^,  Na, 
08 ;  whence  it  appears  to  contain  no  less  than  29  per  cent,  of  nitrogen  or  azote. 
Pekgot  found,  on  an  average,  in  100  parts  of — 

Parts  soluble  in  boiling  Wate 
Dried  black  teas     -  -  -  -  -  -    43*2 

green  teas      --•--.    47.1 

Black  teas,  as  sold  -  -  -  .  .    38.4 

Green  teas,  ditto   -  -  -  -  -  -43*4 

Tea,  by  Mulder's  general  analysis,  has  a  very  complex  constitution;    100  parte 
contain — 


Essential  oil  (to  which  the  flavor  is  due)  - 
Chlorophyle  (leaf-green  matter)    - 

Wax 

Resin         -  -  -  -  « 

Gum  -  .  .  .  . 

Tannin       -  -  -  .  - 

Theine        -  -  -  .  - 

Extractive  matter  -  -  -  - 

Do.        dark-colored 
Colorable  matter  separable  by  muriatic  acid 
Albumine   -  -  -  -  - 

Vegetable  fibre      -  -  -  - 

Ashes         -  -  •  •  - 


Green. 

0-79 
2-22 
0-28 
222 
8-56 

17-80 
0-43* 

22-80 

23-60 
3-00 

17-08 
5-56 


Black. 

0-60 
1-84 

3-64 

7-28 
12-88 

0-46 
19-88 

1-48 
19-12 

2.80 
28-32 

5-24 


Since  the  proportion  of  azote  in  theine  and  caffeine  is  so  much  greater  than  even  in 
any  animal  compound,  urea  and  uric  acid  excepted,  and  since  so  many  different  nations 
have  been,  as  it  were,  instinctively  led  to  the  extensive  use  of  tea,  coffee,  and  chocolate 
or  cocoa,  as  articles  of  food  and  enlivening  beverage,  which  agree  in  no  feature  01 
property,  but  in  the  possession  of  one  peculiar  chemical  principle,  we  must  conclude 
that  the  constitution  of  these  vegetable  products  is  no  random  freak  of  nature,  but  that 
it  has  been  ordained  by  Divine  Wisdom  for  performing  beneficial  effects  on  the  human 
'  race.  Hitherto,  indeed,  medicine,  a  conjectural  art,  exercised  too  much  by  men  super- 
ficially skilled  in  the  science  of  nature,  and  the  slaves  or  abettors  of  baseless  hypotheses, 
has  laid  tea  and  coffee  generally  under  its  ban,  equally  infallible  with  the  multitude, 
as  that  of  the  pope  in  the  olden  time,  and  has  denounced  their  use,  as  causing  a  variety 
of  nervous  and  other  nosological  maladies.  But  chemistry,  advancing  with  her  un- 
quenchable torch  into  the  darkest  domains  of  nature,  has  now  unveiled  the  mystery 
and  displayed  those  elemental  transformations  of  the  organic  functions  in  the  human 
body,  to  which  tea  and  coffee  contribute  a  salutary  and  powerful  aid. 

Liebig,  in  his  admirable  researches  into  the  kingdoms  of  life,  has  been  led  to  infer 
that  the  bile  is  one  of  the  products  resulting  from  the  decomposition  of  the  animal 
tissues,  and  that  our  animal  food  may  be  resolved  by  the  action  of  oxygen,  so  amply 
applied  to  the  lungs  in  respiration,  into  bile  and  urea,  the  characteristic  constituent  of 
urine. 

When  the  consumption  of  tissue  in  man  is  small,  as  among  mankind  in  the  artificial 
state  of  life,  with  little  exercise  and  consequently  languid  digestion,  assimilation,  and 
decomposition,  the  constant  use  of  substances  rich  in  azotized  compounds,  closely  anal- 
ogous to  the  chief  principle  of  the  bile,  must  assist  powerfully  in  the  production  of  this 
secretion,  so  essential  to  the  healthy  action  of  the  bowels  and  other  organs.  Liebig 
has  fully  i)roved  that  the  bile  is  not  an  excrementitious  fluid,  merely  to  be  rejected,  ai 
•  prejudicial  inmate  of  the  system,  but  that  it  deserves,  after  secretion,  some  important 
purpose  in  the  animal  economy,  being,  in  particular,  subservient  to  respiration. 

I  shall  conclude  these  remarks,  perhaps  more  appropriate  to  a  work  on  chemistry 
than  to  the  present,  by  staling  the  relation  between  theine  and  the  animal  product  ia» 
fine,  the  characteristic  constituent  of  bile. 


One  atom  of  theine 

Nine  atoms  of  water    -    = 

Nine  atoms  of  oxygen  -    = 


=       C8,N2,  H5,  O2 
=  Hg,  O9 

09 


Two  atoms  of  taurine. 
=^8,  Nj,  Hk,  Oao- 


*  Thifl  constituent  is  obviously  much  underrated, 


814 


TEA. 


The  letters  C,  N,  H,  0,  denote  carbon,  nitrogen  or  azote,  hydrc^en,  and  oxygen ;  aad 
the  figures  attached  to  each,  the  number  of  atoms ;  one  atom  of  carbon  being  6,  one  of 
azote  H  one  of  hydrogen  1,  and  one  of  oxygen  8;  from  which  the  composition  of 
the  bodies,  theine  and  taurine,  may  be  easily  computed  for  100  parts.  Now,  suppowng 
one  tenth  of  the  bile  to  consist  of  solid  matter,  and  this  solid  matter  to  be  choleio  acid 
(resolvable  into  taurine  bat  different  from  it^  which  contains  3*87  of  nitrogen,  then 
2.8  grains  of  theine  would  afford  to  480  grains  of  bile  (supposed  solid,  or  4,800  grains 
in  its  ordinary  state)  all  the  nitrogen  required  for  the  constitution  of  taurine,  its  peculiar 
crystalline  principle. 

"  The  quantity  of  tea  grown  and  consumed  in  China  can  not  be  ascertained,  but  thiB 
consumption  of  Europe  and  America  may  be  taken  as  follows  :— 


Russia   -  -  - 

United  States  of  America 
France  -  -  - 

Holland 
Other  countries 
Great  Britain    - 


-  6,500,000  lbs. 

-  8,000,000 

-  2,000,000 

-  2,800,000 

-  2,000,000 

-  50,000,000 


71,300,000  lbs.  or  31,830  tons. 

"The  number  of  tea-dealers  in  the  year  1839  was,  in  England,  82,794 ;  in  Scotland, 
13,611 ;  and  in  Ireland,  12,744;  making  a  total  of  109,179.  It  is  presumed  that  incon« 
sequence  of  the  increased  population  their  number  at  present  must  exceed  120,000. 

"  The  observations  of  Liebig  afford  a  satisfactory  explanation  of  the  cause  of  the 
great  partiality  of  the  poor  not  only  for  tea,  but  for  tea  of  an  expensive  and  superior 
kind.  He  says,  *  We  shall  never  certainly  be  able  to  discover  how  men  were  first  led 
to  the  use  of  the  hot  infusion  of  the  leaves  of  a  certain  shrub  (tea),  or  of  a  decoction 
of  certain  roasted  seeds  (coffee).  Some  cause  there  must  be,  which  will  explain  how 
the  practice  has  become  a  necessary  of  life  to  all  nations.  But  it  is  still  more  remark- 
able, that  the  beneficial  effects  of  both  plants  on  the  health  must  be  ascribed  to  one  and 
the  same  substance  (theine  or  caffeine^  the  presence  of  which  in  two  vegetables,  belong- 
ing to  natural  families,  the  products  of  different  quarters  of  the  globe,  could  hanily  have 
presented  itself  to  the  boldest  imagination.  Yet  recent  researches  have  shown,  in  such 
a  manner  as  to  exclude  all  doubt,  that  theine  and  caffeine  are  in  all  respects  identical.' 
And  he  adds,  that  *  we  may  consider  these  vegetable  compounds,  so  remarkable  for 
their  action  on  the  brain,  and  the  substance  of  the  organs  of  motion,  as  elements  of 
food  for  organs  as  yet  unknown,  which  are  destined  to  convert  the  blood  into  nervous 
substance,  and  thus  recruit  the  energy  of  the  moving  and  thinking  faculties.*  Such 
«  discovery  gives  great  importance  to  tea  and  coffee,  in  a  physiological  and  medical 
point  of  view, 

"  At  a  meeting  of  the  Academy  of  Sciences,  in  Paris,  lately  held,  M.  Peligot  read  a 
paper  on  the  chemical  combinations  of  tea.  He  slated  that  tea  contained  essential 
principles  of  nutrition,  far  exceeding  in  importance  its  stimulating  properties ;  and 
showed  that  tea  is,  in  everf  respect,  one  of  the  most  desirable  articles  of  general  use. 
One  of  his  experiments  on  the  nutritious  qualities  of  tea,  as  compared  with  vnose  oC 
soup,  was  decidedly  in  favor  of  the  former. 

"  Coffee  is  grown  in  BrazU,  Cuba,  Hayti,  Java,  British  West  Indies,  Dutch  Guiana, 
•tates  of  South  America,  French  West  India  colonies,  Porto  Rico,  Sumatra,  Ceylon, 
Bourbon,  Manilla,  and  Mocha.  Brazil  produces  the  largest  quantity,  72,000,000 
pounds  weight ;  and  the  other  states  and  colonies  according  to  the  order  in  which  they 
are  enumerated,  down  to  Mocha,  which  produces  the  least,  or  1,000,000  pounds ;  ma- 
king a  total  of  346,000,000  pounds,  equal  to  the  consumption  of  the  enormous  quantity 
of  2,900  tons  weekly,  or  150,800  tons  per  annum. 

**  From  the  official  returns,  the  quantities  of  coffee  exported  in  one  year  from  the 
different  places  of  production  were  154,550  tons: — 


To  France 

U.  S.  of  America 

Trieste 

Hamburg 

Antwerp 

Amsterdam 

TONS. 

-  29,650 

-  46,070 

-  9,000 

-  20,620 

-  10,000 

-  8,530 

Bremen 

St.  Petersburg  - 

Norway  and  Sweden    - 

-  4,500 

-  2,000 

-  1,470 

Denmark 

m 

^ 

TONS. 

1,400 

Spain 

m 

« 

1,000 

Prussia  - 

• 

_ 

930 

Naples  and  Sicily 

- 

s 

640 

Venice    - 

m 

m 

320 

Fiume    - 

m 

. 

170 

Great  Britain  (average  of  10  y'rs) 

18,250 

154,550 


"  Every  reflecting  man  will  admit,  that  articles  of  such  vast  consumption  as  tea  and 


TEA. 


815 


coffee  (amounting  together  to  more  than  185,000  tons  annually),  forming  the  chief 
liquid  food  for  a  whole  nation,  must  exercise  a  great  influence  upon  the  health  of  the 
people,  and  that  any  discovery  that  tends  to  the  purification  of  these  alimentary  drinks, 
rendering  them  more  wholesome,  without  rendering  them  less  agreeable,  is  a  great  boon 
conferred  upon  society. 

TEA,  COMPOSITION  OP.  The  most  remarkable  products  that  have  been  indi- 
cated in  tea  are,-— 1st,  tannin;  2nd,  an  essential  oil,  to  which  it  owes  its  aroma,  and 
which  has  great  influence  on  its  commercial  value ;  3rd,  a  crystalline  substance,  very 
rich  in  nitrogen,  theine,  which  is  also  met  with  in  coffee  (whence  it  is  frequently  termed 
caffeine),  and  which  is  likewise  found  in  Guarana  a  remedy  highly  valued  by  the  Brazilians. 

Besides  these  three,  M.  Mulder  extracted  from  tea  eleven  other  substances,  which  are 
usually  met  with  in  all  leaves.  The  same  chemist  found,  in  the  various  kinds  of  tea 
from  China  and  Java,  a  little  less  than  a  half  per  cent  of  the  weight  of  theine.  Dr. 
Stenhouse,  in  a  recent  investigation,  obtained  from  1-37  to  098  theine  from  100  parts 
of  tea. 

An  accurate  knowledge  of  the  amount  of  the  nitrogenous  principles  contained  in  tea 
being  of  the  utmost  importance,  he  first  determined  the  total  amount  of  nitrogen  con- 
tained in  the  leaf,  in  order  thus  to  have  a  safe  guide  when  subsequently  isolating  the 
substances  between  which  this  nitrogen  is  distributed. 

On  determining  the  nitrogen  by  M.  Dumas's  process,  he  obtained  the  following 
numbers: — 


Pekoe  tea 
Gunpowder  tea 
Souchong  tea 
Assam  tea 


Nitrogen  in  100  parti, 
tea  dried  at  230o. 

6-58 

615 

6-16 

5-10 


This  amount  of  nitrogen  is  far  more  considerable  than  has  been  detected  in  any  v^- 
etable  hitherto  analysed.  These  first  experiments  prove,  therefore,  the  existence  of  from 
20  to  30  per  cent  of  nitrogenous  substances  in  tea,  while  former  analyses  scarcely  cany 
the  proportion  to  more  than  three  or  four  hundredths.  He  sought  for  these  substanoes 
successively  in  the  products  of  the  leaf  soluble  in  boiling  water,  in  those  which  do  not 
dissolve  in  water,  and  in  each  of  the  substances  which  might  be  separated  either  frtmi 
the  infusion  or  from  the  exhausted  leaf. 

He  first  determined  the  proportion  of  soluble  products  which  boiling  water  extracts 
from  tea,  and  operated  upon  27  kinds  of  tea,  taking  into  consideration  the  water  al- 
ready contained  in  the  leaf,  either  from  its  desiccation  in  China  not  having  been  com- 
plete, or  from  having  absorbed  during  or  after  its  transport  a  certain  quantity  of  at- 
mospheric water.  He  found  that  the  green  teas  contain,  on  an  average,  10,  the  Uack 
teas  8  per  cent  of  water. 

The  proportion  of  products  soluble  in  hot  water  varies  considerably,  and  depends 
chiefly  upon  the  age  of  the  leaf,  which  is  younger,  and  consequently  less  liqueoui^  in 
the  green  than  in  the  black  tea.    On  an  average  he  found  in  100  parts  of 


Dry  black  teas    -  .  . 

Dry  green  teas    -  -  - 

Black  teas  in  their  commercial  state 
Green  teas  do  do 


Parts  soluble  in 
boiling  water. 

-  48-2 
•  47*1 

-  88-4 

-  43-4 


When  an  infusion  of  tea  is  evaporated  to  dryness,  a  chocolate  brown  residue  remains, 
which,  when  derived  from  green  gunpowder,  contains  435  per  cent  nitrogen;  if  from 
black  souchong,  4*70  per  cent  nitrogen. 

These  considerable  quantities  of  nitrogen,  do  they  belong  to  several  principles  con- 
tained in  the  infusion,  or  solely  to  the  theine,  which  is  the  only  nitrogenous  substenee 
hitherto  noticed  in  itf  He  first  endeavored  to  solve  this  question:  as  the  quantitative 
determination  of  theine  is  a  difficult  operation  from  its  being  soluble  in  water,  alcohol, 
and  ether,  and  not  being  precipitated  by  any  reagent  with  the  exception  of  tannin,  he 
first  ascertained  whether  the  other  substances  which  might  be  separated  from  the  in- 
fusion contained  any  nitrogen. 

The  subacetete  of  lead  throws  down  about  half  the  soluble  constituents  contained  in 
this  infusion.  The  precipitate,  which  is  of  a  more  or  less  dark  yellow,  according  to 
whether  it  is  derived  from  green  or  black  tea,  contains  the  whole  of  the  coloring  mat- 
ter, the  whole  of  the  tannin,  and  a  peculiar  acid,  which  affords  an  insoluble  stdt  of  a 
light  yellow  color  with  the  subacetate  of  lead.  He  has  not  yet  terminated  the  examina- 
tion of  this  acid. 

I  found  this  mixed  precipitate  to  contain  very  little  nitrogen;  it  is  therefore  in  the 


816 


TEA. 


portion  of  the  infusion  which  is  not  precipitated  that  the  substances  containing  this  ele* 
xnent  must  be  sought  for.  ° 

To  determine  the  amount  of  theine,  M.  Mulder  evaporates  the  infusion  with  caustic 
magnesia,  and  treate  the  residue  with  ether,  which  only  dissolves  out  the  theine.  On 
modifymg  this  process,  Dr.  Stenhouse  has  obtained  the  following  quantities  of  thein« 


Hyson     --..... 

Another  kind      -  .  -  .  . 

Mixture  in  equal  parts  of  gunpowder,  hyson,  imperial 

caper,  and  pekoe         .... 
Gunpowder         -  -  -  .  . 

Another  kind      --..., 


2-40 
2-66 

2-70 

41 

8-5 


These  quantities  are  far  more  considerable  than  have  been  obtained  either  by  K 
Mulder,  or  Dr.  Stenhouse;  but,  at  the  same  time,  they  do  not  account  for  the  total 
amount  of  nitrogen  of  the  infusion  in  the  state  of  theine,  for  the  composition  of  theine 
being  represented  by  the  formula  C^HsN^O',  and  this  substance  containing  290  per 
cent  of  nitrogen,  gunpowder  tea  should  contain  7-4  and  souchong  6-6  theine  in  100 
parts  of  these  teas  taken  in  their  ordinary  state,  if  no  other  nitrogenous  substance  ao- 
companied  the  theme  in  the  solution. 

By  the  following  very  simple  process,  I  succeeded  in  obtaining  a  proportion  of  theine 
far  more  considerable  than  I  first  found.  To  the  hot  infusion  of  tea  subacetate  of  lead 
and  then  ammonia  are  added;  the  liouid  is  separated  by  filtration  from  the  precipi- 
tate, and  a  current  of  sulphuretted  hydrogen  passed  through  it,  the  sulphuret  of  lead  is 
removed  from  the  solution,  which  is  evaporated  at  a  gentle  heat;  on  cooling,  an  abun- 
dant crop  of  crystals  of  theine  is  obtained,  and  the  mother  lye  affords  more  crystals  on 
cautious  evaporation.  The  first  crystals  are  purified  by  recrystallization  from  water, 
and  then  the  mother  lye  is  used  to  dissolve  the  second  crop,  so  as  to  have  the  least 
possible  quantity  of  mother  lye  and  the  largest  amount  of  crystals.  In  this  manner  I 
obtained  from  60  grammes  of  gunpowder  tea  1-92  grammes  of  crystallized  theine.  which 
18  equal  to  8*84  per  cent 

But  there  remains  a  syrupy  liquid  which  still  contains  some  theine.  This  I  deter- 
™^5  T  t.  T.™^*°®  ^^  ^  solution  of  tannin  of  known  strength,  which  precipitates  it  alone, 
and  I  believe  entirely,  if  the  liquid  be  cold  and  accurately  neutralized  with  ammonm 
as  the  tannin  is  added. 

On  adding  the  fresh  qaantity  of  theine,  isolated  by  this  re-agent  to  that  obtained  as 
crystals,  one  hundred  parts  of  gunpowder  tea,  taken  in  its  ordinary  state,  furnished  6-84 
th^e;  100  parts  of  the  same  tea  in  its  dry  state  gave  622  of  this  substance. 

These  numbers  approach  very  nearly  to  those  which  should  be  obtained  if  theine  were 
the  only  nitrogenous  substance  contained  in  the  infusion.  There  is,  however  still  a 
deficit  of  O-YS  nitrogen,  but  it  must  be  remembered  that  I  obtained  only  a  minimum. 
It  18,  moreover,  possible  that  the  infusion  contained  some  ammoniacal  salts,  or  that  a 
snaall  portion  of  the  theine  was  decomposed  during  the  evaporation  of  the  liquid  •  this 
substance  being  very  liable  to  alteration,  like  the  compounds  rich  in  nitrogen,  which  it 
resembles  by  its  composition  and  properties. 

However  this  be,  it  may  be  concluded  from  the  above  experiments,  1,  that  theine  is 
tne  principal  nitrogenous  substance  contained  in  the  infusion  of  tea.  2.  that  it  exists  in 
la^r  quantity  than  has  hitherto  been  admitted.  " 

The  portion  of  tea  from  which  boiling  water  extracted  no  more  soluble  principle 
contained  m  100  parts,  dried  280°,  4-46  nitrogen  for  the  souchong,  and  4  80  for  the 
gunpowder.  These  quantities,  added  to  those  of  the  infusion,  represent  very  nearly 
the  nitrogen  ascertained  by  analysis  to  exist  in  the  entire  leaf.  J  J 

On  boiling  for  some  time  the  exhausted  leaves  in  water  containing  yV  of  their  weiffht 
of  potash,  a  brown  liquid  is  obtained,  which  affords,  on  the  addition  of  dilute  sulphuric 
or  acetic  acid,  a  considerable  flocculent  and  brown  precipitate,  which  contains  8  45  per 
cent  nitrogen  ;  the  product  of  another  preparation  gave  9-98.  Alcohol  and  ether  re- 
move  froni  this  precipitate  about  30  per  cent  of  a  green  substance,  which  appears  to 
contain  a  fat  acid.  This  product  is  not  pure  after  this  treatment,  for  it  is  strongly  col- 
ored and  contains  pectic  acid;  nevertheless  that  which  contained  8-45  nitrcjen  af. 
forded  11 -SS  of  this  element  after  being  treated  with  alcohol  and  ether.  Although  I 
have  not  obtained  this  substance  in  a  state  of  purity,  I  do  not  hesitate  to  consider  it 
from  the  general  resenablance  of  its  characters,  as  identical  with  the  caseine  from  milk. 
It  18  probable  that  this  body  exists  in  the  insoluble  portion  of  the  leaf  in  combination 
with  tannin,  and  that  the  potash  acts  by  destroying  this  combination.  The  presence 
ot  this  substance  m  tea  is  a  fact  the  more  worthy  of  attention  as  it  occurs  to  a  very  large 
amount^  if,  as  is  probable,  the  greater  portion  of  the  nitrogen  in  the  exhausted  leaf  is 


TEA. 


817 


derived  from  it  On  admitting,  with  MM.  Dumas  and  Cahours,  16  per  cent  of  nitroge* 
in  caseine,  the  exhausted  leaves  would  contain  no  less  than  28  hundredths  of  this  prin- 
ciple ;  tea  in  its  ordinary  state  would  contain  from  14  to  16  per  cent 

I  found  it  impossible  to  separate  the  whole  of  this  caseine  from  the  tea.  I  obtained, 
in  one  experiment,  from  100  parts  of  exhausted  leaves,  36  of  the  mixture  above  men- 
tioned, containing  from  8  to  10  per  cent  nitrogen,  which  represent  from  18  to  20  p« 
cent  of  caseine  supposed  pure ;  out  the  leaves,  after  being  treated  twice  with  potaish, 
still  contained  2*73  per  cent  This  nitrogen,  in  the  state  of  caseine,  would  represent  b1 
per  cent,  so  that  we  thus  approach  very  close  to  the  amount  of  the  nitrogen  indicated 
by  analysis. 

It  will  be  seen  from  these  experiments,  that  tea  contains  a  proportion  of  nitrogen 
altogether  exceptional ;  it  must,  however,  be  remembered  that  the  leaf  is  not  taken  in 
its  natural  state,  but  that  it  comes  to  us  after  having  been  manufactured.  It  is  well- 
known  that,  before  being  delivered  into  commerce,  tea  is  submitted  to  a  torrefaction, 
which  softens  the  leaf  and  allows  of  a  rather  considerable  quantity  of  an  acrid  and 
slightly  corrosive  juice  being  expressed  by  means  of  the  pressure  of  the  hands;  the  leaf 
is  then  rolled  up,  and  dried  more  or  less  rapidly  according  to  whether  green  or  black 
tea  is  to  be  made  from  it  Now  it  is  possible  that  this  juice  contains  little  or  no  nitro- 
gen, and  that  consequently  it«  separation  would  increase  the  amount  of  nitrogen  which 
remains  in  the  leaf.  On  determining  the  quantity  contained  in  fresh  leaves  from  some 
tea  plant  cultivated  in  gardens  near  Paris,  I  found  4"37  nitrogen,  in  100  parts  of  the 
dried  tea.  Perhaps  the  difference  of  climate  and  mode  of  culture  may  suffice  to  pro- 
duce these  variations. 

•  I  will  conclude  this  paper  by  some  observations  on  the  use  of  tea  considered  as  ber- 
erage  and  as  aliment  It  cannot  be  denied,  considering  the  amount  of  nitrogen  con- 
tained in  this  leaf  and  the  presence  of  caseine,  that  tea  is  a  true  aliment  when  con- 
sumed as  a  whole,  with  or  without  previous  infusion,  as,  according  to  information,  some 
of  the  Indian  tribes  do. 

We  find  the  following  statement  in  one  of  Victor  Jacquemont's  letters:  "Tea  comes 
to  Cashmere  by  caravans,  through  Chinese  Tartary  and  Thibet  .  .  .  It  is  pre- 
pared with  milk,  butter,  and  salt,  and  an  alkaline  of  salt  of  a  bitter  taste.  At  Kurnoor 
it  is  prepared  in  a  different  manner ;  the  leaves  are  boiled  for  an  hour  or  two,  the 
water  is  thrown  away,  and  the  leaves  mixed  with  rank  butter,**  Ac  Is  it  not  evident 
that  in  the  first  case  the  instinctive  use  of  the  alkaline  salt  has  for  its  object  the  solu- 
tion of  the  caseine,  and  thus  causing  it  to  form  part  of  the  infusion,  while  in  the  second 
the  caseine  remains,  and  is  consumed  with  the  leaf  itself. 

But  it  is  not  in  this  manner  that  tea  is  prepared  among  the  more  civilized  nations. 
Ought  we  to  admit  that  its  infusion,  made  with  little  and  much  water,  has  any  other 
actions  but  on  the  nervous  system,  by  producing  an  excitement  which  may  for  a  certain 
time  form  a  substitute  for  veritable  food  ?  Can  it  be  compared  to  other  substances  of 
undoubted  efficacy  as  nutriment,  to  milk  or  to  meat  broth  ?  Without  seeking  to  solve 
these  difficult  questions,  I  have  determined  some  of  the  elements  which  must  occupy 
an  important  rank  in  their  discussions.  I  have  determined  the  weight  and  the  nature 
of  the  principles  which  enter  into  the  infusion  of  tea,  as  it  is  usually  prepared  for  drink- 
ing. The  tea  is  not  then  deprived  of  all  its  soluble  principles ;  the  leaf  still  retains  at 
least  a  third  of  what  it  abandons  to  water  when  submitted  to  frequent  washings,  an 
infusion,  for  instance,  made  with  20  grains  of  gunpowder  tea  and  one  quart  of  water 
afforded  6*83  grains  of  soluble  products,  containing  very  nearly  one  grain  of  theine. 
— Peligot,  in  Comptes  Rendus,  July  17,  1843. 

TEA,  greeii,  contains  34-6  parts  of  tannin,  6-9  of  gum,  5-7  of  vegetable  albumine, 
51-8  of  ligneous  fibre,  with  2-5  of  loss;  and  black  tea  contains  406  of  tannin,  BS  of 
gum,  5;4  of  vegetable  albumine,  44*8  of  ligneous  fibre,  with  2  of  loss.  The  ashes  con- 
tain silica,  carbonate  of  lime,  magnesia,  and  chloride  of  potassium. — Frank.  Davy  ob- 
tained 32-5  of  extract  from  Souchong  tea ;  of  which  10  were  precipitated  by  gelatine. 
He  found  8'5  only  of  tannin  in  green  tea.  The  latter  chemist  is  most  to  be  depended 
ujpon.  Chemical  analysis  has  not  yet  discovered  that  principle  in  tea  to  which  its  ex 
citing  property  is  due. 

Preparation  of  green  tea.  It  is  brought  to  Canton  unprepared ;  as  Bohea,  Sauehvnff, 
and  is  thrown  into  a  hemispherical  iron  pan,  kept  red-hot  over  a  fire.  The  leaves  are 
constantly  stirred  till  they  are  thoroughly  heated,  when  they  are  dyed,  by  adding  for 
each  pound  of  tea,  1  spoonful  of  gypsum,  1  of  turmeric,  and  2  or  8  of  Prussian  bine. 
The  leaves  instantly  change  into  a  bluish  green,  and  after  being  well  stirred  for  a  few 
minutes,  and  are  taken  out^  being  shrivelled  by  the  heat  They  are  now  sifted ;  the 
small  longish  leaves  fall  through  the  first  sieve,  and  form  young  Hyson ;  the  roundest 
granular  ones  fall  through  the  last  and  constitute  Gunpowder,  or  Choo-cha. 

The  Chinese  method  oj  making  Black  Tea  in  Upper  Assam.*-~In  the  first  place,  the 

*  By  C.  A  Bruce,  superintendent  of  tea  culture. 

Vol.  II.— 52 


818 


TEA. 


TELEGRAPHS. 


819 


foungest  and  most  tender  leaves  are  gathered;  but  when  there  are  many  hands  and  ft 
great  quantity  of  leaves  to  be  collected,  the  people  employed  nip  off  with  the  forefinger 
and  thumb  the  fine  end  of  the  branch  with  about  four  leaves  on,  and  sometimes  even 
more,  if  they  look  tender.     These  are  all  brought  to  the  place  where  they  are  to  be 
converted  into  tea;  they  are  then  put  into  a  large,  circular, open-worked  bamboo  basket, 
having  a  nm  all  round,  two  fingers  broad.     The  leaves  are  thinly  scattered  in  these 
baskets,  and  then  placed  in  a  frame- work  of  bamboo,  in  all  appearance  like  the  tide  of  an 
Indian  hut  without  grass,  resting  on  posts,  2  feet  from  the  ground,  with  an  an"le  of 
about  25*.     The  baskets  with  leaves  are  put  in  this  frame  to  dry  in  the  sun,  and  are 
pushed  up  and  brought  down  by  a  long  bamboo  with  a  ciicular  piece  of  wood  at  the 
end.     The  leaves  are  permitted  to  dry  about  two  hours,  being  occasionally  turned ;  but 
the  time  required  for  this  process  depends  on  ihe  heat  of  the  sun.    When  they  bepiln  to 
have  a  slightly  withered  appearance,  they  are  taken  down  and  brought  into  the  house 
where  they  are  placed  on  a  frame  to  cool  for  half  an  hour.     They  are  then  put  into 
smaller  baskets  of  the  same  kind  as  the  former,  and  placed  on  a  stand.    People  are  now 
employed  to  soften  the  leaves  still  more,  by  gently  clapping  them  between  their  hands, 
with  their  fingers  and  thumb  extended,  and  tossing  them  up  and  letting  them  fall,  for 
about  five  or  ten  minutes.     They  are  then  again  put  on  the  frame  during  half  an  hour, 
and  brought  down  and  clapped  with  the  hands  as  before.    This  is  done  three  successive 
times,  until  the  leaves  become  to  the  touch  like  soft  leather ;  the  beating  and  putting 
away  being  said  to  give  the  tea  the  black  color  and  bitter  flavor.     After  this  the  tea 
is  put  into  hot  cast-iron  pans,  which  are  fixed  in  a  circular  mud  fireplace,  so  that  the 
name  cannot  ascend  round  the  pan  to  incommode  the  operator.     This  pan  is  well  heated 
by  a  straw  or  bamboo  fire  to  a  certain  degree.     About  two  pounds  of  the  leaves  are  then 
put  into  each  hot  pan,  and  spread  in  such  a  manner  that  all  the  leaves  may  get  the  same 
degree  of  heat.    They  are  every  now  and  then  briskly  turned  with  the  naked  hand,  to 
prevent  a  leaf  from  being  burnt.     When  the  leaves  become  inconveniently  hot  to  the 
hand,  they  are  quickly  taken  out  and  delivered  to  another  man  with  a  close-worked 
bamboo  basket  ready  to  receive  them.     A  few  leaves  that  may  have  been  left  behind  are 
smartly  brushed  out  with  a  bamboo  broom ;  all  this  time  a  brisk  fire  is  kept  up  nnder 
the  pan.     After  the  pan  has  been  used  in  this  manner  three  or  four  times,  a  bucket  of 
cold  water  is  thrown  in,  and  a  soft  brickbat  and  bamboo  broom  used,  to  give  it  a  good 
scouring  out ;  the  water  is  thrown  out  of  the  pan  by  the  brush  on  one  side,  the  pan 
itself  being  never  taken  off.    The  leaves,  all  hot  on  the  bamboo  basket,  are  laid  on  a 
table  that  has  a  narrow  rim  on  its  back,  to  prevent  these  baskets  from  slipping  ofl*  when 
pushed  against  it.     The  two  pounds  of  hot  leaves  are  now  divided  into  two  or  three 
parcels,  and  distributed  to  as  many  men,  who  stand  up  to  the  table  with  the  leaves  right 
before  them,  and  each  placing  his  legs  close  together ;  the  leaves  are  next  collected  into 
a  ball,  which  he  gently  grasps  in  his  left  hand,  with  the  thumb  extended,  the  fingers 
close  together,  and  the  hand  resting  on  the  little  finger.    The  right  hand  must  be  ex- 
tended in  the  same  manner  as  the  left,  but  with  the  palm  turned  downwards,  resting  on 
the  top  of  the  ball  of  tea  leaves.    Both  hands  are  now  employed  to  roll  and  propel  the 
ball  along ;  the  left  hand  pushing  it  on,  and  allowing  it  to  revolve  as  it  moves ;  the  right 
hand  also  pushes  it  forward,  resting  on  it  with  some  force,  and  keeping  it  down  to 
express  the  juice  which  the  leaves  contain.     The  art  lies  here  in  giving  the  ball  a  cir- 
cular motion,  and  permitting  it  to  turn  under  and  in  the  hand  two  or  three  whole 
revolutions,  before  the  arms  are  extended  to  their  full  length,  and  drawing  the  ball  of 
leaves  quickly  back  without  leaving  a  leaf  behind,  being  rolled  for  about  fiv'e  minutes  in 
this  way.    The  ball  of  tea  leaves  is  from  time  to  time  gently  and  delicately  opened  with 
the  fingers,  lifted  as  high  as  the  face,  and  then  allowed  to  fall  again.     This  is  done  two 
or  three  times,  to  separate  the  leaves ;  and  afterwards  the  basket^with  the  leaves  is  lifted 
up  as  often,  and  receives  a  circular  shake  to  bring  these  towards  the  centre.    The  leaves 
are  now  taken  back  to  the  hot  pans,  and  spread  out  in  them  as  before,  being  again  turn- 
ed with  the  naked  hand,  and  when  hot  taken  out  and  rolled;  after  which  they  are  put 
into  the  drying  basket,  and  spread  on  a  sieve  which  is  in  the  centre  of  the  basket,  and 
toe  whole  placed  over  a  charcoal  fire.    The  fire  is  very  nicely  regulated ;  there  must  not 
be  the  least  smoke,  and  the  charcoal  should  be  well  picked. 

When  the  fire  is  lighted,  it  is  fanned  until  it  gets  a  fine  red  glare,  and  the  smoke  is  all 
Irone  off;  being  every  now  and  then  stirred  and  the  coals  brought  into  the  centre,  so  as 
^  leave  the  outer  edge  low.  When  the  leaves  are  put  into  the  drying  basket,  they  are 
gently  separated  by  lifting  them  up  with  the  fingers  of  both  hands  extended  far  apart, 
And  allowing  them  to  fall  down  again ;  they  are  placed  3  or  4  inches  deep  on  the  sieve, 
Ifeavmg  a  passage  in  the  centre  for  the  hot  air  to  pass.  Before  it  is  put  over  the  fire,  We 
drying  basket  receives  a  smart  slap  with  both  hands  in  the  act  of  lifting  it  np,  which  it 
done  to  shake  down  any  leaves  that  might  otherwise  drop  through  the  sieve,  or  to  pre- 
vent  them  from  falling  into  the  fire  and  occasioning  a  smoke,  which  would  affect  and 
•poll  the  tea.    This  slap  on  the  basket  is  invariably  applied  throughout  the  stages  of  the 


tea  manufacture.  There  is  always  a  large  basket  underneath  to  receive  the  small  leaves 
that  fall,  which  are  afterwards  collected,  dried,  and  added  to  the  other  tea;  in  no  case 
are  the  baskets  or  sieves  permitted  to  touch  or  remain  on  the  ground,  but  always  laid  on 
a  receiver  with  three  legs.  After  the  leaves  have  been  half  dried  in  the  drying  basket, 
and  while  they  are  still  soft,  they  are  taken  off  the  fire  and  put  into  large  open-worked 
baskets,  and  then  put  on  the  shelf,  in  order  that  the  tea  may  improve  in  color. 

Next  day  the  leaves  are  all  sorted  into  large,  middling,  and  small ;  sometimes  there 
are  four  sorts.    All  these,  the  Chinese  informed  me,  become  so  many  different  kinds  of 
teas ;  the  smallest  leaves  they  called  Pha-ho,  the  second,  Pow-chong,  the  third  Su-chong, 
and  the  fourth,  or  the  largest  leaves,  Toy-chong.     After  this  assortment  they  are  again 
put  on  the  sieve  in  the  drying  basket  (taking  great  care  not  to  mix  the  sorts),  and  on 
the  fire,  as  on  the  preceding  day ;  but  now  very  little  more  than  will  cover  the  bottom  of 
the  sieve  is  put  in  at  one  time,  the  same  care  of  the  fire  is  taken  as  before,  and  the  same 
precaution  of  tapping  the  drying  basket  every  now  and  then.    The  tea  is  taken  off  the 
fire  with  the  nicest  care,  for  fear  of  any  particle  of  the  tea  falling  into  it.    Whenever 
the  drying  basket  is  taken  off,  it  is  put  on  the  receiver,  the  sieve  -n  the  drying  basket 
taken  out,  the  tea  turned  over,  the  sieve  replaced,  the  tap  given,  and  the  basket  placed 
again  over  the  fire.     As  the  tea  becomes  crisp,  it  is  taken  out  and  thrown  into  a  lai^e 
receiving  basket,  until  all  the  quantity  on  hand  has  become  alike  dried  and  crisp ;  from 
which  basket  it  is  again  removed  into  the  drying  basket,  but  now  in  much    larger 
quantities.     It  is  then  piled  up  eight  and  ten  inches  high  on  the  sieve  in  the  drying 
basket ;  in  the  centre  a  small  passage  is  left  for  the  hot  air  to  ascend ;  the  fire  that  was 
before  bright  and  clear,  has  now  ashes  thrown  on  it  to  deaden  its  effect,  and  the  shakings 
that  have  been  collected  are  put  on  the  top  of  all ;  the  tap  is  given,  and  the  basket  with 
the  greatest  care  is  put  over  the  fire.     Another  basket  is  placed  over  the  whole,  to  throw 
back  any  heat  that  may  ascend.    Now  and  then  it  is  taken  off,  and  put  on  the  receiver ; 
the  hands,  with  the  fingers  wide  apart,  are  run  down  the  sides  of  the  basket  to  the  sieve, 
and  the  tea  gently  turned  over,  the  passage  in  the  centre  again  made,  &c.,  and  the  basket 
again  placed  on  the  fire.     It  is  from  time  to  time  examined,  and  when  the  leaves  have 
become  so  crisp  that  they  break  by  the  slightest  pressure  of  the  fingers,  it  is  taken  off, 
when  the  tea  is  ready.     All  the  different  kinds  of  Ifeaves  underwent  the  same  operation. 
The  tea  is  now  little  by  little  put  into  boxes,  and  first  pressed  down  with  the  hands  and 
then  with  the  feet  (clean  stockings  having  been  previously  put  on). 

There  is  a  small  room  inside  of  the  tea-house,  7  cubits  square  and  5  high,  having 
bamboos  laid  across  on  the  top  to  support  a  net-work  of  bamboo,  and  the  sides  of 
the  room  smeared  with  mud  to  exclude  the  air.  When  there  is  wet  weather,  and  the 
leaves  cannot  be  dried  in  the  sun,  they  are  laid  out  on  the  top  of  this  room,  on  the  net- 
work, on  an  iron  pan,  the  same  as  is  used  to  heat  the  leaves ;  some  fire  is  put  into  it, 
either  of  grass  or  bamboo,  so  that  the  flame  may  ascend  high  ;  the  pan  is  put  on  a  square 
wooden  frame,  that  has  wooden  rollers  on  its  legs,  and  pushed  round  and  round  this 
little  room  by  one  man,  while  another  feeds  the  fire,  the  leaves  on  the  top  being 
occasionally  turned;  when  they  are  a  little  withered,  the  fire  is  taken  away,  and  the 
leaves  brought  down  and  manufactured  into  tea,  in  the  same  manner  as  if  it  had  been  dried 
in  the  sun.  But  this  is  not  a  good  plan,  and  never  had  recourse  to,  if  it  can  possibly  be 
avoided. 

Tea  imported  into  the  United  Kingdom,  in  1836,  49,307,701  lbs. ;  in  1837,  36,765,735 
lbs.  Retained  for  home  comsumption,  in  1836, 49,841,507  lbs. ;  in  1837,  31,872  lbs.  Duty 
received,  in  1836,  £4,728,600;  in  1837,  £3,319,665. 

TEASEL,  the  head  of  the  thistle  (Dipsactts),  is  employed  to  raise  the  nap  of  cloth.  See 

Woollen  Manufacture. 

TEETH      ^ee  Bones. 

TELEGRAPHS,   ELECTTRICAL,   PRUSSIAN.     These  telegraphs  are  used  on  aU 

Prussian  government  lines,  and  on  most  of  the  railway  lines  of  Northern  Germany; 

making  a  total  of  about  3,000  miles ;  besides  extensive  lines  which  at  present  are  in 

course  of  construction  in  Russia  and  other  countries. 

Indicating  Telegraphs. — Keys  are  arranged  round  a  dial,  each  key  bearing  a  letter  of 
the  alphabet ;  one  line  wire  is  used,  which  connects  two  or  more  instruments  at  different 
stations.  A  hand  on  each  dial  revolves  in  concert  with  the  hands  on  the  remaining 
instruments ;  but  by  pressing  down  a  key  on  any  of  them,  all  the  hands  stop,  pointing  to 
the  same  letter,  until  the  key  is  again  released.  These  instruments  differ  essentiallr 
from  other  telegraphs,  inasmuch  as  they  are  entirely  electrical  machines,  which  break 
and  reclose  their  own  contacts  in  a  similar  manner  as  a  steam-engine  works  its  slide. 

The  electric  current  in  passing  through  the  line  wire,  and  the  coils  in  each  instrument 
cause  the  armatures  to  be  attracted  by  its  motion  to  break  the  circuit ;  the  armatures  ara 
then  quite  at  liberty  to  fall  back,  and  in  so  doing  each  instrument  re-establishes  the 
circuit,  and  the  succeeding  stroke  takes  place.  In  pressing  down  a  key,  the  armature  is 
stopped  from  falling  bacl^  and  consequently  no  current  can  pass  through  the  line  wire 


I 


[820] 

A  TABLE    OF 

ARRANGED  FOR  THE  USE  OF  THE  PRACTICAL  CLASSES  IN  THE 

H.B.— The  action  of  the  most  important  Compounds  of  the  Substances  in  the  vertical  cohmjn   with  th« 
Btudeat  of  the  science;  and  by  a  comparlaon  of  these  actions,  this  Uble  will  be  found  a  most  valuable 


SALTS  OF  POTASH  .  . 
SODA  •  •  •  •  • 
LITHU 

BAR xTA  •  •  •  •  • 
BTRONTIA      .... 


UME        .... 

MAGNESIA     .       .       . 

ALUMINA       ... 

GLUCINA        ,       .       . 

THORINA  .  .  . 
TTTRIA  .... 
ZIRCONIA 


AMMONIA. 


CERIUM 


j PROTOXIDE 

(peroxide 


No  preeipitote. 
No  preeipitote. 
No  preeipitote. 


A  Tolaminoha  precipi 
tote,  soluble  in  a  larg^e 
qumnUty  of  water. 


No  preeipitote  nnleia 
left  for  some  days. 


Same  asStrootia. 


A  bnllcy  preeipitote 
eompletely  soluble  in 
Muriate  of  Ammonia. 


A  white  precipitate  in- 
soluble in  Muriate  of 
Ammonia  and  in  ex- 
cess, but  soluble  in 
Potash. 

A  white  preeipitote  in- 
soluble in  excess  and  in 
Muriate  of  Ammonia. 


A^latinons  preeipitote 
insoluble  in  excess. 


POTASH. 


A  Toluminous  preeipi- 
tote, soluble  in  a  large 
quantity  of  water. 


Same  as  Baryto;  not 
quite  so  soluble. 


CARBONATE  OP 
POTASH. 


No  immediate  preeipi- 
tote, bat  after  a  time 
a  granular  one. 

A  white  precipitate, 
soluble  with  eiKirTe*- 
cence  in  free  acids. 


Same  as  Baryta. 


BICARBONATE  OP 
POTASH. 


The  some ;  not  quite  so  1  he  same  asBaiyto  and 
soluble.  Strontia. 


A  white  preeipitote 
insoluble  in  excess  ; 
soluble  in  Muriate  of 
Ammonia. 

A  preeipitote  soluble  in 
excess,  in8<iluble  in 
Muriate  of  Ammonia. 


A  preeipitote  complete- 
ly soluble  in  excess. 


Thai 


A   white    Tolnminoos   The 
preeipitote    insoluble 


IB  excess. 


MANGANESE,  PROTOXIDE 


(SESQUIOXIDE 
MANGANESE-j  and 

(PEROXIDE 


ZINC 


COBALT 


NICKEL 


(PROTOXIDE 
i         and 
(  PEROXIDE 


(PROTOXIDE 
^  and 

(  PEROXIDE 


mON,  PROTOXIDE 


(  SESQUIOXIDE 
IRON   .        .<  and 

( PEROXIDE 


A  white  preeipitote  in- 
soluble in  excess. 


A  white  precipitate, 
taming  brown,  Insol- 
uble in  excess. 


A  white  preeipitote, 
soluble  in  Muriate  of 
Ammonia,  turning 
brown  at  the  surface 


A  dark  brown  preeipi- 
tote, insoluble  in  Mu- 
riate of  Ammonia. 


A  white  gelatinons  pre- 
cipitate, soluble  in 
excess. 


A  blue  preeipitote,  solu- 
ble in  excess,  forming 
a  greenish  solution, 
taming  brown. 

A  slight  green  trou- 
bling, then  a  clear 
blue  solution,  preeipi- 
toted  green  by  Potash 

A  green  preeipitote, 
soluble  in  Muriate 
of  Ammonia,  turning 
brown  in  contact  with 
the  air. 

A  reddish  brown  pre- 
eipitote, insoluble  in 
Moriate  of  Ammonia. 


TTie  same  ;    perfectly 
insoluble  in  excess. 

The  same. 


A  white  preeipitote, 
turning  brown,  insol- 
uble in  Muriate  of 
Ammonia. 


The 


The  same  as  Ammonia. 


A  blue  precipitate,  in- 
soluble, turning  £reen 
and  pale  red  when 
boiled. 


An  apple  green  preei- 

pitHte,    insoluble 
excess. 


A  white  preeipitote, 
soluble  inMunateof 
Ammonia. 


The 


The 


The  Muna  aa  BarjiM. 


The 


No  preeipitote  nnleaa 
the  solution  be  boiled, 
then  a  strong  one. 


A  white  preeipitote,  The  same  ;  Carbonic 
soluble  m  Caustic  >  Acid  eas  is  diseneaeed. 
Potash.  *  * 


A  preeipitote  soluble  in   The 
a  great  excess  of  pre- 
cipitont. 


A    white    preeipitote, 
soluble  in  excess. 


A  white  preeipitote, 
slightly  soluble  in  a 
great  excess. 

A  white  precipitate, 
slightly  soluble  in  a 
great  excess. 

A  white  precipi  tot  , 
slightly  soluble  in  ex- 


A  green  preeipitote, 
insoluble  in  excess, 
turning  brown  at  the 
Mirfisoe. 


The  same. 


A  permanent  white 
precipitate.  sHghtly 
soluble  in  Muriate  of 
Ammonia. 

A  brown  voluminous 
preeipitote. 


A  white  precipitate, 
insoluble  in  excess, 
but  soluble  in  Muriate 
of  Ammonia  or  Caus- 
tic Alkalies. 

A  red  preeipitote  which 
boiling  renders  blue 


A  lighter  green  preeipi- 
tote. 


The 


The  same ;  completely 
soluble  m  a  great  ex 
cess. 


nnlMiveiy 


A  white  preeipitote, 
soluble  in  Muriate  of 
Ammooia. 


A  lighter  brown  preei- 
pitote. 


The  same. 


The 


The  sanu 
dilute. 


The 


A  white  preeipitote 
which  behaves  m  thft 
same  manner. 


A  red  preeipitote. 


The  same  ^    Carbonic 
Acid  gas  u  given  oS. 


The 


The    same  ;   Carbonia 
Acid  is  disengaged 


[821] 

ANALYTICAL   CHEMISTRY 

PESTALOZZIAN  INSTITUTION,  WORKSOP,  BY  JAMES  HAYWOOD. 

Eeagents  in  the  horizontal,  arc  generally  of  so  characteristic  a  nature  as  not  to  be  mistalcen  by  the  youngest 
Assistant  to  the  proficient  in  Chemistry  in  conducting  an  analysis,  or  in  general  experimental  researcn. 


CARBONATE  OF 
AMMQNIA. 


SULPHURETTED 
HYDROGEN. 


No  preeipitote. 


The  HUM. 


The 


The 


Same  at  the  Bicarbonate 
of  Potash,  soluble  in 
Muriate  of  Ammonia. 


The  tame. 


A  white  preeipitote,  sol- 
able  in  excess. 


The 


The  same. 


The  same;  more  easily 
soluble  in  excess. 


Thesama. 


TheaaoM. 


The  same. 


A  white  preeipitote,  sol- 
uble in  excess. 


No  preeipitote. 


No  precipitate. 


No  preeipitote. 


No  precipitate. 


HYDROSULPHATE 
OF  AMMONIA. 


YELLOW  PRUSSIATE    RED  PRUSSIATE  OF 
OF  POTASH.  i  POTASH. 


No  preeipitote  in  any 
solution. 


No  preeipitote. 


No  preeipitote. 


No  preeipitote. 


No  preeipitote. 


No  preeipitote. 


No    preeipitote  nnless 
Ammonia  l>e  added. 


A  milk-white  preeipitote 
of  Sulphur  ;  solution 
then  contoins  a  Frote- 
salt. 


No   preeipitote  if  the 
test  is  pure. 


A  white  preeipitote  of 
Alumina,  soluble  in 
Potash. 


A  white  preeipitote,  sol- 
uble in  PotasD. 


A  white  predpitote  of 
Thorina. 


A  preeipitote  of  Yttria. 


No  preeipitote. 


No  precipitate. 


A  white  heavy  preeipi- 
tote, soluble  m  acids. 


A  white  preeipitote. 


No  precipitate. 


A  voluminous  preeipitote.   A  white  preeipitote. 


A  white  preeipitote  of 
Protoxide. 


A  flesh-red  preeipitote, 
turning  brownish  in 
contoct  with  the  air. 


The  flesh-red  preeipi- 
tote —  the  preeipitote 
by  Ammonia  is  turned 
flesh-red  by  it. 


A  white  preeipitote   if    A  white  preeipitote,  in- 
neutral,   but  none    if      soluble  m  excess, 
acid. 


A  red  preeipitote,  solu-    No  preeipitote ;  solution 
ble  in  Muriate  of  Am-       turns  darker. 


A  green  precipitate,  sol- 
uble in  excess,  forming 
a  bluish  solution. 


Thesame. 


A  light  brown  preeipi- 
tote. 


No  preeipitote ;  solution 
turns  darker. 


No  preeipitote. 


A  milk-white  preeipitote 
of  Sulphur;  solution 
then  contains  Protoxide, 


A  black  precipitate,  in- 
soluble m  excess. 


A  black  preeipitote  and 
color,  slightly  soluble 
in  excess. 


A  black  precipitate,  turn- 
ing brown  at  the  surface. 


A    black  preeipitote  — 
same  as  tae  Protoxide. 


A  white  preeipitote. 


A  pale  red  preeipitote, 
soluble  in  uee  acida. 


A  grayish  green  preei- 
pitote. 


A  gelatinous  white  pre- 
eipitote, insoluble  in 
Muriatic  Acid. 


A  green  preeipitote, 
turning  gray,  insoluble 
in  Muriatic  Acid. 


A  white  preeipitote  — 
tilightly  tending  to 
green,  insoluble  in  Mu- 
riatic Acid. 


A  light  blue  preeipitote, 
turning  darlcer,  insolu- 
ble in  Muriatic  Acid. 


An  immediate  dark  blue 

Srecipitote,  insoluble  in 
luriatie  Acid. 


No  precipitate. 
No  preeipitote. 
No  precipitate. 
No  precipitate. 


A  brown  preeipitote,  in- 
soluble m  free  acida. 


The  same  as  tlie  Protox- 
ide. 


A  yellowish  red  predpi- 
tote, soluble  in  Muria- 
tic Acid. 


A  reddish  brown  pred- 

Sitote,     insoluble     in 
luriatie  Acid. 


A  yellowish  green  pre- 
cipitate, insoluble  in 
Munatic  Acid. 


An  immediate  dark  bln« 
preeipitote,  insolnble 
m  acids. 


No  preeipitote. 


822] 


A  TABLE  OF  ANALYTICAL 


CHEMISTRY— Continued. 


[823 


SALTS  OF  POTASH 


•• 


SODA 


UTHIA    . 


BARYTA. 


STRONTLA 


LUIE 


liAGNESU     . 


ALUMINA 


GLUCINA 


THORINA 


YTTRIA  . 


ZIRCONIA 


•       •       • 


CKRIUM  . 


j PROTOXIDE 
1  PEROXIDE 


MANGAXESE,  PROTOXIDE . 


(SESQUIOXIDE 
MANGANESE  ■{  and 

(  PEROXIDE 


ZINC. 


COBALT 


mCKEL 


(PROTOXIDE 

-{         and 

I  PEROXIDE 


(PROTOXIDE 
<        and 
( PEROXIDE 


IRON,  PROTOXIDE 


IRON 


i 


(SKSQUIXODE 
<  and 

(PEROXIDE 


OXALIC  ACED. 


No  preeipiUta. 


No  precipitate  unlet 
left  for  some  day«. 


A  troubling  in  strong 
•olutiona;  if  Ammo- 
nia be  added  a  pre- 
cipitate. 

An  immediate  preci- 
pitate, soluble  m  Ni- 
tric or  Muriatic  Acid. 


No  precipitAt«  unleM 
Ammonia  be  added. 


No  precipitate. 


No  precipitate. 


A  white  precipitate, 
ioaoluble  in  exceu. 


A  white  precipitate, 
soluble  in  Muriatic 
Acid. 


A  white  precipitate, 
soluble  m  a  great 
excess  or  in  Muriatic 
Acid. 

A  white  precipitate, 
even  in  acid  solu- 
tions, sparingly  solu- 
ble in  Muriatic  Acid. 


A  white  crystallme 
deposit,  onlesa  very 
dilute. 


'So  precipitate,  bat 
the  solution  is  soon 
rendered  colorless. 


A  white  precipitate, 
soluble  in  free  Acids 
and  Alkalies. 


A  slight  troubling  and 
shortly  a  pale  red 
precipitate. 


No  immediate  precipi- 
tate, but  a  slow  de- 
posit. 

A  yellow  color,  and 
shortly  a  precipitate. 


No  precipitate ;  solu- 
tion turns  yellowish. 


IODIDE  OF 

POTASSIUM. 


SULPHATR  OF 
POTASH. 


PHOSPHATE  OF 
SODA. 


No  precipitate. 


No  precipitate. 


No  precipitate. 


A  white  precipitate, 
if  Ammonia  be  add- 


A  voluminous  white 
precipitate,  insoluble 
in  strong  acids. 


The  same  as  Baryta ; 
rather  more  soluble 
in  water. 


No  precipitate  in  di- 
lute solutions,  but  a 
white  one  if  strong. 


No  precipitate. 


After  a  time  Crystals 
of  Alum  are  formed. 


No  precipitate ;  but  if 
Aiuinonia  be  added, 
a  strong  one. 


A  white  precipitate, 
aoluble  in  free  acids. 


Same  as  Baryta. 


Same  aa  Baryta. 


A  white  precipitate, 
particularly  if  Am- 
monia be  added. 


A  white  precipitate, 
soluble  in  Acids  or 
Potash. 


No  erystala  are  formed.  A  voluminoua  precipi- 
tate. 


Thrown  down  aa  a 
double  salt,  insoluble 
in  excess. 


After  a  time  a  precipi- 
tate is  formed,  but  is 
easily  soluble  is  an 
excess. 

A  white  precipitate, 
almost  insoluble  in 
water  and  acids. 


After  a  time  a  precipi- 
tate insoluble  in  ex- 
cess. 


No  precipitate. 


No  precipitato. 
No  precipitate. 
No  precipitate. 
No  precipitate. 


A  white  flaky  precipi- 
tate. 


A  white  precipitate, 
soluble  in  acids,  but 
is  Again  precipitated 
by  boiling. 

A  voluminous  precipi- 
tate. 


A  white  precipitate. 


A  permanent   white 
precipitate. 


A  brown  precipitate  in 
neutral  solutions. 


A  white  precipitate, 
soluble  in  free  Acids 
and  Alkalies. 


A  blue  precipitate. 


A  white  precipitate, 
slightly  tendmg  to 
green. 


A  white  precipitate, 
turning  green. 


A  white  precipitate, 
which  Ammonia 
tnrnH  brown,  and  at 
length  dissolves. 


.^p 


BEFORE  THE  BLOWPIPE. 


Ko  pndpitaU, 


OBSERVATIONS. 


On  Platinnm  wire  tinges  outer  flame 
violet :  with  Borax  and  Oxide  of 
Nickel,  a  blue  l>ead. 

The  bead  of  Nickel  and  Borax  is  not 
changed  by  Soda;  heated  on  Pla- 
tinum wire  tinges  outer  flame  yel- 
k)w. 

Tinges  outer  flame  of  a  carmine  color ; 
the  double  phosphate  is  fusible. 


Cannot  easily  be  distinguished ;  the 
Chloride  tinges  outer  flame  green- 
ish; infusible  alone;  fusible  with 
flaxes. 

Tinges  outer  flame  carmine  red  when 
heated  on  Platinum  wire. 


Same  as  Strontia,  only  not  so  bright ; 
gives  a  powerful  white  light  when 
strongly  heated. 

When  ft  Salt  of  Magnesia  that  hae 
been  heated,  is  moistened  with 
Nitrate  of  Cobalt,  it  acquires  a  pale 
red  color. 

Treated  as  the  above  on  Charcoal,  a 
fine  blue  color  is  communicated  to 
the  assay. 


Gives  a  white  precipitate  with  Tartanc  Acd,  a  yeUowow 

with  Chloride  of  Pfatinum,  and  a  golatmous  one  ^^J^»y^ 
fluosilicic  Acid,  which  distinguishes  it  from  other  subetancea. 

Gives  no  precipitate  with  Tartaric  Acid,  or  Chbride  of  Flftti- 
nam,  by  which  it  may  be  diitingiufthed. 


No  precipitate  with  Chloride  of  Plfttinwn ;  can  ea«ly  be  di»- 
tinguished  firom  the  former. 


Easily  distinguished  by  forminje  •  white  precipiute  with 
Sulphates  LxA  Carbonates.  The  Chloride  is  msoluUe  u» 
AlcohoL 

Distinguished  from  Baryta  by  giving  a  precipitate  yi}l«  Hydro- 
fluosnicic  Acid,  and  by  the  filtered  liquid  of  the  still  Alkaline 
Sulphate  giving  a  precipiUte  with  BaryU  water. 

DlBtiniruiBhed  from  Baryta  and  Strontia  by  giving  no  prwdpi 
tate  with  Sulphates  when  diluted,  separated  m  the  sUte  ot 
Nitrates  and  Chlorides  by  AlcohoL 

EasUy  distinguished  and  separated  by  Sulphates  from  the 
above,  or  by  the  precipiUtes  being  all  soluble  m  MunaU  of 
Ammonia. 

Distinguished  f^m  the  Alkalis  by  givme  a  white  precipiUte 
with  Ammonia,  and  may  be  separated  from  most  other  sub- 
stances by  Caustic  Potash. 


When  moistened  with  Nitrate  of  Co- 
balt, becomes  dark  gray,  or  nearly 
bladL. 

Not  easily  distinguished ;  produces  a 
colorless  bead  with  Borax. 


Yttria  behaves  in  the  same  manner 
MGlncina. 


Cannot  easily  be  distingoished  from 
similar  substances. 


Converted  to  peroxide,  soluble  m 
Borax,  producing  a  red  bead,  color 
flies  on  cooling. 


Produces  a  bead  of  an  amethyst  col- 
or in  the  outer  flame  with  Borax, 
which  disappears  in  the  inner  flame. 

Same  as  Protoxide. 


On  Charcoal  with  Soda  a  coat  of 
white  Oxide  is  formed;  with  Ni- 
trate of  Cobalt  they  aaeume  a  green 
color. 

The  smallest  portion  colors  Borax 
strongly  blue ;  reduced  to  a  metallic 
aUte  with  Soda;  magnetic 

With  Borax  in  the  outer  flame,  a 
reddish  color,  which  disappeara 
when  cold ;  with  Soda,  a  white 
magnetic  powder. 

With  Borax  in  the  outer  flame,  a  red 
bead,  turning  lighter  as  it  cools; 
mterior  flame  a  green  bead,  turning 
lighter  on  cooling. 

Peroxide  behaves  b  the  same  man- 
ner ;  with  Soda,  a  magnetic  powder 
is  obtained. 


Maybe  distinguUhed  from  Alumina  by  the  Cwbonates, from 
aiagnesia  by  being  insoluble  in  Muriate  of  Ammonia,  ana 
from  Lime  and  the  Alkalis  by  Ammonia. 

Thorina  may  be  distinguished  and  senarated  from  the  abovjs 
substances,  as  it  is  perfecUy  insoluble  alter  igmUon  m  all 
acids  except  the  Sulphuric 

Distinguished  from  Thorina  by  Sulphate  of  Potash,  and  f^m 
the  other  suUtanoes  described  by  the  same  means  as  Thorma. 


Distinguished  from  Thorma  by  Sulphate  of  Potash  and  Oxalic 
Acidfand  from  Yttria  by  its  Oxide,  after  igmUon,  bemg  insol- 
table  in  all  Acids,  except  the  Sulphuric 

Distinguished  from  other  substances  previoosly  described  by 
tummg  into  a  red  Peroxide  when  heated  m  contact  ^ith  the 
atmosphere. 


The  reaction  of  these  salU  with  Hydroaulphate  of  Ammonia 
is  to  well  chaiacterixed  that  they  cannot  be  mistaken. 


The  Peroxide  is  alwavs  converted  into  the  Deutoxide  by  solo- 
tion  in  an  Acid.  MuriaUc  Acid  converU  it  mto  Protoxide  by 
boiling. 

The  solution  in  Potash  is  precipitated  by  Hyd.  Sal.  Am.  which 
distinguishes  it  from  earthy  salts,  and  may  easUy  be  lep^ 
rated  from  other  metals  by  Ammonia. 


Easily  distinguUhed  from  all  other  salU  by  their  behavior 
wiu  Hydroeolphate  of  Ammonia. 

Distinguished  from  Cobalt  by  Ammonia  and  Potash,  and  from 
other  subetanoes  in  the  aame  way  aa  Cobalt. 

The  Salta  of  Iron  are  easily  distinguished  ^J  *«^^^^ 
with  the  Prussiates ;  may  be  separated  from  Manganese  by 
Succinate  of  Soda. 

Peroxide  if  distinguished  and  separated  from  Protoxide  by 
Red  Pmssiate  of  Potash  and  Ammonia. 


824] 


A  TABLE  OF  ANALYTICAL 


CHEMISTEY— CoNTnnjED. 


[825 


i 


CADMIUM 


LEAD 


BISMUTH 


j  PROTOXIDE 
(  PEROXIDE 


COPPER,  DEUTOXIDE  . 
SlliV  EIR    «        •        •        • 

MERCURY,  PROTOXIDE 
MERCURY,  PEROXIDE 
PLATDTA 

GOLD  .  . 
TXN.PROTOXTOE 

TIN,  PEROXIDB 
ANTIMONY    . 
CHROMIUM    . 

TANADIUM  . 
COLUMBIUM  . 
IRIDIUM.  . 
RHODIUM  . 
PALLADIUM  . 
OSMIUM  . 
TELLURIUM  . 
TTIAimTM      . 

TUNGSTEN  . 
URANIUM  . 
MOLYBDENUM 


AMMONIA. 


A  white  preeipitAt«, 
•olubl«  m  ft  slight 
ezceu. 

A  white  precipitate, 
inaoluble  in  an  ez- 
cesa,  except  with  the 
Acetate. 

A  white  precipitate, 
inaoluble  in  excess. 


A  green  precipitate, 
and  deep  purple  solu- 
tion ;  again  precipitat- 
ed by  Potash  if  boiled. 

A  brown  precipitate, 
▼ery  soluble  in  ex- 
cess, but  is  repreci- 
pitated  by  Potash. 

A  black  precipitate, 
insoluble  in  excess. 


A  white  precipitate, 
insoluble  in  an  excess. 


A  yellow  precipitate, 
soluble  in  excess,  in- 
soluble m  free  acids. 


A  yellow  precipitate. 


A  white  precipitate, 
insoluble  in  excess. 


A  white  precipitate, 
soluble  in  acids  and 
in  an  excess. 

A  white  precipitate 
insoluble  in  excess 
and  in  Muriatic  Acid. 

A  ^eenish  blue  preci- 
pitate, insoluble  in 
excess. 

A  grayish  white  pre- 
cipitiite,  turning  red 
and  dissolving. 

Is  readily  dissolved, 
and  may  be  again 
precipitated  by  acids. 

A  brown  precipitate, 
partly  soluble,  form- 
ing a  purple  solution. 

Shortly  a  lemon  yel- 
low color. 


A  yellowish  precipi- 
tate, slightly  soluble 
in  excess. 

No  precipitate;  solu- 
tion turns  yellow. 


A  white  precipitate, 
soluble  in  excess. 


A  white   precipitate, 
insoluble  in  excess. 


The  Acid  dissolves,  but 
is  again  precipitated 
by  stronger  acids. 

A  brown  flaky  preci- 
pitate, insoluble  in 
excess. 

The  Acid  is  dissolved, 
and  the  Protoxide 
forms  a  brown  preci- 
pitate. 


POTASH. 


A  white    precipitate, 
insoluble  in  excess. 


A  white  precipitate, 
soluble  in  a  great  ex- 
cess. 


The  same. 


A  fp-een  precipitate, 
which  boiling  renders 
black. 


A  brown  precipitate, 
insoluble  in  excess, 
but  soluble  in  Am- 
monia. 

A  black  precipitate, 
soluble  in  an  excess. 


A  yellow  or  white  pre- 
cipitate, insoluble  in 
excess. 

A  yellow  precipitate, 
soluble  in  e xcesa  when 
boiled ;  and  again  pre- 
cipitated by  acids. 

At  first  no  precipitate, 
but  shortly  a  black 
one. 

A  white  precipitate, 
soluble  in  excess ;  de- 
composed by  boiling. 

The  same,  soluble  in 
excess. 


The  same,  soluble  in 
Muriatic  Acid. 


A  green  precipitate,  sol- 
uble in  excess ;  again 
thrown  down  by  boil- 
ing. 

The  same. 


The  same,  insoluble  in 
strong  acids. 


A  dark  brown  preci- 
pitate. 


A  yellow  precipitate, 
soluble  in  acids. 


An  orange  colored  pre- 
cipitate from  the  Ni- 
trate. 

Fused  with  it,  the 
whole  is  soluble  in 
water. 

A  white  precipitate, 
soluble  m  excess ;  re- 
precipitated  by  acids. 

The  same. 


The  same. 


A  yellowish  precipi- 
tate, insoluble  in  ex- 
cess. 

llie  same ;  precipitate 
insoluble  m  excess. 


CARBONATE  OF 
POTASH. 


A  white   precipitate, 
insoluble  m  excess. 


A  white  precipitate, 
inaoluble  in  excess ; 
but  soluble  in  Potash. 


The 


A  green  precipitate, 
which  boiling  renders 
black. 


BICARBONATE  OF 
POTASH. 


soluble 


_  precipitate, 

ill  Ammonia. 


A  dirty  yellow  preci- 
pitate, which  boiling 
renders  black. 

A  reddish  brown  pre- 
cijpitate ;  if  it  contains 
Muriate  of  Ammonia 
a  white  one. 

A  yellow  precipitate, 
insoluble  va  excess. 


No  precipitate. 


A  white  precipitate, 
insoluble  in  excess. 


The  same;  deposits 
slowly  again  after 
solution. 

The  same. 


A  green  precipitate, 
slightly  soluble  in 
excess. 

A  grayish  white  pre- 
cipitate, soluble   in 


The  same,  and  may 
be  dissolved  by  Ace- 
tic Acid. 

No  precipitate ;  color 
destroyed. 


A  gelatinous  precipi- 
tate when  boiled  with 
the  double  Chloride. 

A  deep  brown  precipi- 
tate, insoluble  in  ex- 
cess. 

No  precipitate ;  solu- 
tion turns  yellowish. 


The  same. 


The  same. 


Is  insoluble  in  water 
when  fused  with  it. 


The  same,  slightly  sol- 
uble. 


A  brown  precipitate, 
soluble  in  excess. 


A  white  precipitate. 
Carbonic  Acid  is  dis- 
engaged. 

A  similar  precipitate, 
with  an  evolution  of 

The  same. 


A  light  green  preci- 
pitate, soluble  m  an 
excess. 


The  same. 


A  white  precipitate, 
rendered  black  by 
boiling. 

A  reddish  brown  pre- 
cipitate, either  imme- 
diate or  after  a  time. 

The  same  ;  Muriatic 
Acid  must  be  added 
in  all  cases. 


No  precipitate. 


The  same. 


A  white  precipitate, 
insoluble  ia  excess. 


The  same. 


The    same ;    rather 
lighter. 


The  same. 
The  same. 
The  same. 
No  precipiteto. 
The  same. 
The  same. 
The  same. 
The 


The 


The 


. CARBONATE  OF 
AMMONIA. 


A  white  precipitate,  in- 
solnble  m  excess. 


The  same. 


®"hySS^?J^^     I    HTOROSULPHATE 
HYDROGEN.  OF  AMMONIA. 


The  same. 


A  green  precipitate,  sol- 
uble in  excess,  same  as 
Ammonia. 

A  white  precipitate,  sol- 
nble  in  excess. 


A  gray  or  black  precipi- 
tate. 


A  white  precipitate. 
A  yellow  precipitate. 


A  yellow  precipitate,  if 
neutral. 


The  same. 


Tbeiune. 


The  same. 


A  yellow  precipitate. 


A  black  precipitate,  in 
both  neutral  and  acid 
solutions. 


A  black  precipiute,  in 
both  neutral  and  acid 
solutions. 

A  black  or  dark  brown 
precipitate,  in  both 
neutral  and  acid  solu- 
tions. 

A  black  precipitate,  in 
both  neutral  and  acid 
solutions. 


A  black  precipitate,  in 
acid  and  neutral  solu- 
tions. 

A  black  precipitate,  turn- 
ing white,  and    again 
black   by   an    excess, 
soluble  in  Potash. 

A  brown  color  and  short- 
ly a  precipitate. 


YELLOW  PRUSSIATE 
OF  POTASH. 


A  yellowish  precipitate, 
insoluble  in  excess. 

A  black  precipitate,  in- 
soluble m  excess. 


A  black  precipitate,  in- 
soluble IB  excess. 

The  same ;  insoluble  in 
excess. 


A  black  precipitate,  in- 
soluble m  excess. 


RED  PRUSSIATE  OF 
POTASH. 


A  slightly  yellow  preci- 
pitate, soluble  in  Muri- 
atic Acid. 

A  white  precipitate. 


A  white  precipitate,  sol- 
uble in  Muriatic  Acid. 

A  reddish  brown  preci- 
pitate, insoluble  in  Mu- 
riatic Acid. 

A  white  precipitate. 


A  black  precipitate,  in 
both  acid  and  neutral 
solutions. 

A  dark  brown  precipi- 
tate, in  both  acid  and 
neutral  solutions. 

No  immediate  precipi- 
tate, but  shortly  a  yel- 
low one. 

A  red  precipitate  in  acid 
solutions. 


A  black  precipitate,  in- 
soluble in  excess,  part- 
ly soluble  in  Potash. 

The  same ;  solution  must 
be  neutral. 

A  brown  precipitate,  sol-    A  yellow  precipitate,  so- 
uble  m  a  large  excess.        lution  tujrns  ^ker. 


A  white  gelatinous  pre- 
cipitate. 

A    white     precipitate, 
turning  blue. 


The  same ;  approaching 
to  violet. 


The  same,  insoluble  in 
excess. 


The  same. 

The  same. 
No  precipitate. 
Tliesame. 
The  same. 
The  same. 
The  same. 


No  precipitate  in  any  so- 
lutions. 


Generally  a  brown  pre- 
cipiute, in  ether,  acid, 
or  neutral  solutions. 


A  dark  brown  precipi- 
tate. "^ 


A  dark  brown  precipi- 


A  brown  precipitate,  sol- 
uble in  excess. 

A  brown  precipitate,  sol- 
uble in  excess,  repre- 
cipitated  by  Muriatic 
Acid. 

A  yellow  precipitate,  sol- 
uble in  excess. 


A  red  precipitate,  solu- 
ble in  an  excess. 


An  emerald  green  color. 


A  white  gelatinous  pre- 
cipitate. 


;  No  precipitate  at  first, 
but  shortly  the  whole 
I    forms  a  thick  jelly. 

A  white  precipitate,  in- 
soluble in  AlnnaUc  Acid. 


A  yellow  precipitate, 
soluble  in  Muriatic 
Acid. 

No  precipitate. 


A  pale  yellow  precipi- 
tate, soluble  in  Muria- 
tic Acid. 

A  yellowish  green  pre- 
cipitate, insoluble  in 
Muriatic  Acid. 


A  reddish  brown  preci- 
piUte. 


A  reddish  brown  preci- 
pitate, turning  wnite. 

A  yellow  in  most  eola- 
tions, but  none  with 
the  Perchloride. 

The  same. 


No  precipitate. 


A  white  precipitate,  sol- 
uble in  Munaiic  Acid. 


A  greenish  precipitate,    j  No  precipitate. 


A  brown  precipitate. 

A  black  precipitate,  sol- 
uble in  Potash. 

No  precipitate. 


A  grayish  white  preci- 
pitate. 

No  action  with  the  Acid, 
but  a  brown  precipitate 
with  the  Oxide. 

The  same ;  soluble  in 
excess. 


No  precipitate. 


No  precipitate. 


No  precipitate,  but  short, 
ly  a  slight  opacity.        11 

No  precipitate. 


A  yellowish  precipitate, 
■olnble  in  ezcees. 

The  tame. 


No  precipitate. 
No  precipiute. 


A  brown  precipitate,  in 
Alkaline  solutions. 


The  same. 


The  same;   solnble  in 
excess. 


The  same,  or  in  excess. 


A  dirty  green  precipitate, 
unless  Tartaric  Acid  be 
present,  then  no  preci- 
pitate. 

A  precipitate,  soluble  in 
excess. 


A  black  precipitate, 
slightly  soluble  in  ex- 
cess. 

The  same,  if  Muriatic 
Acid  be  added. 


A  yellowish  green  pre- 
cipitate. 

No  precipiute. 


No  precipiute. 

An  orange  or  olive  yel- 
low precipitate. 

No  precipitate. 
No  precipitate. 


•A|^eep  orange  prccipi- 


No  precipitate. 
No  predpiUto. 
The  same. 


A  brownish  red  precipi- 
tate. ^ 


A  brown  precipiute. 


The  same. 


i 


826] 


A  TABLE  OF  ANALYTICAL 


CADMIUM 


LEAD 


BISMUTH 


r PROTOXIDE 
(  PEROXIDE 


COPPER,  DEUTOXIDE  . 
SILVER    .... 

MERCURY,  PROTOXIDE 

MERCURY,  PEROXIDE 

PLATINA 
GOLD       .       . 
TIN,  PROTOXIDE 
TIN,  PEROXIDE 
ANTIMONY     . 

CHROMIUM    . 
VANADIUM    . 
COLUMBIUM  . 
IRIDIUM .       . 
RHODIUM       . 
PALLADIUM  . 
OSinUM  .       . 
TEU.URIUM  . 
TITANIUM      . 
TUNGSTEN     . 
CHANIUM       • 
MOLYBDENBM     r 


OXALIC  ACID. 


An  immedUta  preci- 
pitate, soluble  in 
Ammonia. 

An  immediate  fihUe 
precipitate. 


No  imm6diftt«  preeipi- 
tat«,  but  after  a  time 
a  granular  one. 


IODIDE  OF 
POTASSIUM. 


A  yellow  precipitate, 
■oluble  in  a  great  ex- 
cess. 


A  brown  precipitate, 
soluble  in  excess. 


A    greenish    precipi-     A  while  precipiUte, 
late.  soluble  in  a  great  ex- 


A  white   precipitate, 
■oluble  in  Ammonia, 


A  white  precipitate. 


A  white  precipitate, 
but  none  m  the  Per- 
chloride. 


No  precipitate. 


A  dark  color,  and 
shortly  the  Gold  is 
precipitated. 

A  white  precipitate. 


No  precipitate. 


A  white   preeipitato, 
caused  by  water. 


No  preeipitata. 


eesa. 


A  yellowish    precipi- 
tate, soluble  in  excess. 


SULPHATE  OF 
POTASH. 


A  white  precipitate, 
Tery  insoluble. 


No  precipitate,  except 
from  the  water  of  so- 
Intion. 


No  precipitate. 


A  white  precipitate, 
unless  the  solution 
be  diluted  ;  soluble 
in  water. 


PHOSPHATE  OF 
SODA. 


A  greenish  yellow  pre- 1  A  white  precipitate, 
cipitate,         rendered 
black  by  an  excess  and 
at  length  diasolres. 


A  fine  scarlet  precipi- 
tate, soluble  in  excess 
and  in  Muriatic  Acid. 


A  deep  brown  color, 
and  precipitale,which 
boiling  reduces. 

A  dark  color,  and  a 
yellowish  precipitate. 


A  yellowish  precipi- 
tate, turning  red, 
soluble  in  excess. 

No  precipitate. 


The  same. 


A  greenish  precipi- 
tate, eoluble  m  Moiri- 
stie  Acid. 


Dissolves  the  Ozirde. 


Noaetioo. 


Tnms  darker,  but  ia 
not  precipitated. 


A  white  floeculeatyr*- 

upitate. 


A  white  precipitate. 


No  precipitate. 


No  predpitate. 


A  white  precipitate, 
partial. 


No  precipitate. 


The  same. 


No  precipitate. 


No  precipitate. 


Fused  with  it,  the  Oz> 
ide  remains  after 
boiling. 

No  precipitate  or  ac- 
tion. 


Fused  with  the  BisnI- 
phate,  the  whole  dia- 
.  solves  in  water. 

An  orange  yellow  pre- 
cipitate. 


No  precipitate  or  ao- 
twn. 


A  white  precipitate. 


A  white  precipitate, 
soluble  in  Potish. 


A  white  precipitate. 


A  greenish  white  prjB- 
cipitate,  soluble  in 
Ammonia. 

A  yellow  predpitate, 
soluble  in  Ammonia. 


A.  white  precipitate. 


A  white  precipitate  in 
most,  but  none  in  the 
Percnloride. 


No  precipitate. 
No  precipitate. 
A  white  precipitate. 
A  white  precipitate. 
The  same. 


A  light  green  precipi- 
tate. 


No  precipitate. 


Does  not  form  a  doable 
■alt. 


No  doable  salt. 


CHEMISTRY— Continued. 


[827 


METALUC  ZINC. 


Is  precipitated  as  small 
metallic  spangles. 

Precipitates  in  a  crystal- 
line metallic  state. 


Precipitates  it  from  the 
milky  soliilion  even  as  a 
spongy  mass. 


Zinc  and  Iron  both  preci- 
pitate nietallic  copper 
Irom  all  its  solutions. 

Is  precipitated  in  a  metal- 
Uc  state. 


Forms   a    gray  coating, 
which  is  an  amalgam. 


Same  aa  Protoxide. 


A  black  metallic  powder. 


BEFORE  THE  BLOWPIPE. 


Heated  with  Soda  on  charcoal,  in  the 
inner  flame  a  brownish  red  powder 
sublimes. 

Heated  on  charcoal  with  Soda,  ia  re- 
duced to  metallic  globules,  which  are 
malleable,  a  yellow  powder  sublimes 
—produces  clear  glass  with  Borax. 

On  charcoal  are  easily  reduced  to 
brittle  nietallic  f^lnbulea— a  yellow 
Oxide  sublimes ;  with  Borax,  a  clear 
glass. 

Outer  flame  with  Borax,  a  fine  green 
bead  ;  inner  flame  dirty  red ;  with 
Soda  is  reduced. 

With  Borax  in  the  outer  flame  a 
milky  glass;  with  Soda  is  easily 
reduced. 


Heated  in  a  glass  tube  with  a  little 
Soda,  Mercury  sublimes  and  con- 
denses m  small  globules. 


OBSERVATIONS. 


A  brown  boiky  coating. 


Small  grayish  white  span- 
gles of  Tin. 


A  white  jelly.  Hydrogen 
Gas  is  disengaged. 

Precipitated  in  the  form 
of  a  black  powder. 


Same  aa  Protoxide. 


Completelr  reduced,  but  gives  no 
color  to  fluxes  or  flame. 


No  precipitate. 


Precipitated  aa  a  dark 
powder. 


Precipitated  firom  the  dou- 
ble Chloride  of  Rhodium 
and  Soda. 

Precipitated  in  a  metallic 


Same  as  Platina,  insoluble  in  all  acids 
except  Nitro-Muriatio. 

Easily  reduced  with  Soda:  deprives 
a  bead  of  Copper  and  Microcosmic 
Salt  of  its  green  color. 

Reduced  on  charcoal ;  forms  a  white 
enamel  with  glass ;  does  not  dissolve 
easily  m  Borax. 

Reduced  with  Soda,  rapidly  oxidizes 
and  sublimes  in  the  outer  flame  as  a 
thick  white  smoke. 

A  fine  emerald  green  bead,  both  in 
the  inner  and  outer  flame,  with 
fluxes.  I 

In  the  inner  flame,  with  Borax,  a 
green  glass  •  outer  becomes  yellow. 

Effervercei  with  Soda ;  a  clear  jrlass 
with  Borax,  ol  the  Phosphoric  Salt. 


Distinguished  by  Sulphuretted  Hydrogen,  and  may  be  sepa- 
rated from  all  the  above  by  a  bar  of  Zinc. 

Solutions  of  Lewi  give  a  precipitate  with  Sulphuric  Acid  and 
^ulpbate8,  and  therefore  may  be  distinguished  frcm  most 
other  metals.  Muriatic  Acid  also  precipiutes  Lead,  but  wa- 
ter dissolves  the  precipitate. 

May  be  detected  by  giving  a  precipitate  with  waUr  alone,  and 
by  lU  reaction  with  Potash  and  Sulphuretted  Hydrogen. 


^their  hfhfr'  can  b«/««ily  distinguished  from  other  salU  by 
their  behavior  with  Ammonia  and  Potash. 

^sIirdlJ'w'.''^i  \V°'^\*'"'*°  ?*''"«  P'«ipit*te  insoluble  in 
SiLuJi^'s!  '"  '"""'"•^  ^^'"^  distinVishes  it  {^^ 

^^i^^h^A^"''^  ^'**?  '"''"«  Precipitate  insoluble  in  acids. 
^uT^lfuZ'^arof^T^Z^^'  by  S'phnrettad 


Easily  recognized  by  its  behavior  with  Potash  and  Ammonl.  • 
may  be  separated  by  Muriate  of  Potash.  Ammoma , 

Protochloride  of  Tin  gives  a  deep  purple  color  and  precipitate 
»m"r»VX^r'Sl^'^'^  ''"  ^""'  which  dStin'^it; 

""J-'SSh^k^Jr  ^"'^  "'^  ^''''' "  "--. » •"-w-t 

The  Peroxide  is  insoluble  in  all  acids  after  ienition  •  Nitri* 
Acid  oxidixea  Tin,  but  does  not  dissolve  the  Sr ' 

The  Oxide  is  volatile  and  insoluble  in  Nitric  Acid  :  mav  be  di. 
»;^'ut/-^t^o^tS^ffir«^'«<^H^«^-^en^ 


Its  solutions  are  W"*"/ ^en  and  may  be  distinguished  from 
tions  by  Sulphuretted  >Iydrogen: 


..a  iTuiuuuuB  are  usuaii 
most  other  solutions  1 


^^liiuSK^AlLSli;^.'"'  ^f^^  ^-I~n  by  Hy- 
^Vuble'i^  waS.^""""'  "'  Carbonated  AlkaU.  the  whole  iM 


Precipitated  aa  a  dark 
powder. 

Ta  precipitated  as  a  black 
powder. 

A  deep  blue  color  is  pro- 


In  Muriatic  Acid  a  bine 
Oxide  is  formed. 


In  a  Muriatic  solution  of 
the  acid  a  blue  and  red 
powder. 


No  action  with  fluxes ;  no  odor ;  may 
be  cupelled  with  lead. 


No  action  with  fluxes. 
Same  as  Rhodium. 


Gives  a  strong  odor  of  Chlorine ;  has 
no  action  with  fluxes;  maybe  cu- 
pelled with  lead. 

A  white  glass  when  cold,  with  flux- 
es ;  fumes  when  heated  alone. 

With  Soda,  a  yellow  glass,  opaque 
when  cold,  with  Borax,  and  inner 
name  a  blue  glass. 

With  Borax,  a  clear  glass  in  the  outer 
flame,  yellow  in  the  inner ;  blood- 
red  with  Iron  and  Phosphorous  Salt. 

On  Platinum  with  Borax,  a  clear  yel- 
low  glass,  outer  flame  dirty  crreen  • 
not  volatile.  ' 

Sublimes  aa  a  white  powder :  a  clear 
glass  with  Borax. 


^watlr^'but^rfi!;^?''*  of  Potash,  the  result  is  not  *>luble  in 
Tott         ^^^^''''  "*  ^"'■"'^*'  '^"«''  producing  v«io«« 

Insoluble  in  acids  a^r  ienition;  distinguished  and  separated 
iiohoK^  ^  '"^'  '^^  "l^^We  t-Woride  is  soffii^ 

TheCyanideof  Mercury  will  easily  separate  Palladium  as  a 
yellow  precipitate ;  the  Chloride  Is  soluble  in  AIcohoL 

'^SllatioJ.*^*^  ^^''  *  ^"^^^  precipitate;  «.p.rated  by 

»Iay  be  sepamted  from  most  other  metals,  combined  with 
Chlorme  or  Hydrogen-both  compounds  being  volatile. 

''i.'S'^if '*^**'^  ^y^^""** '.  distinguished  from  other  metals  by 
moS    '"""^  "^  ^"'*  "•*  Hydrosulphate  of  Am- 

Sulnhuric,  Nitric,  and  Muriatic  Acids  precipitate  its  Alkaline 
mSc  Ac^d      *""^^  ^'*"'"^  *'^^°  *^*^*'*  *'*^  ^''*^ 

Separated  from  most  metals  by  dissolving  in  CWrbooate  of 
Ammonia  or  Soda ;  its  solutions  are  green. 

Distinguished  by  Carbonates,  but  separated  by  Hydroaulithata 
ofAmmoma.  * 


IRREGULAR  PAGINATION 


820 


TESTS. 


TEXTILE  FABRICS. 


821 


until  it  is  released.  The  motion  of  the  armature  is  transferred  to  a  notched  wheel,  the 
Bpindle  of  which  carries  the  hand  on  the  dial.  In  the  same  case  with  each  telegraph  is 
an  alarum  which  is  also  worked  by  the  electric  circuit,  only  at  the  time  when  the  com- 
mutator arm  is  placed  in  the  position  of  "rest,"  and  that  of  another  station  is  moved  on 
"telegraphs."  The  alarum  continues  to  sound  until  the  arm  of  the  telegraph,  which  is 
to  receive  a  message,  is  also  placed  on  the  telegraph,  when  the  instruments  begm  to 
work,  making  about  35  revolutions,  or  1,060  double  strokes  of  the  armature  per 

Printing  telegraphs  are  also  worked  by  the  electric  current  only,  without  the  aid  of 
clockwork  Their  arrangement  is  similar  to  that  of  the  indicating  telegraph.  In  place 
of  the  hand  on  the  dial,  there  is  a  type  wheel  with  30  springs,  each  carrymg  a  type;  it 
stops  with  the  hand  of  the  indicating  telegraph,  at  which  moment  a  hammer  placed 
below  the  wheel  strikes  against  it,  and  prints  the  letter  on  a  strip  of  paper,  which  passes 
over  a  blackened  roller  turning  round  with  it  so  as  always  to  oflfer  new  surfaces  to  the 
hammer.  The  hammer  is  worked  by  a  magnet,  which  is  excited  by  the  same  battery 
which  works  the  type  wheel :  its  current  is  continually  broken  and  restored  by  the 
movements  of  the  armature  of  the  type  wheel ;  but  as  the  type  wheel  stops,  the  current 
becomes  permanent,  and  accumulates  sufficient  power  to  raise  the  hammer,  which  in  so 
doing  breaks  its  own  current  and  falls  back  again.  ,,.,.,.       ^,  v  -„^ 

The  printing  telegraph  is  placed  always  by  the  side  of  the  indicating  telegraph,  and 
records  each  message  on  both  or  all  stations.  . 

By  this  means  mistakes  in  the  transmission  of  the  messages  are  made  morally  im 
possible.  The  current  being  always  broken  on  both  or  all  the  stations,  currents  arising 
from  bad  insulation  of  the  line  wire  will  not  influence  the  harmonious  working  ot  the 
instruments,  as  long  as  these  currents  are  not  strong  enough  to  work  one  or  the  other 
instruments  by  their  own  action,  and  the  receiver  of  the  message  will  always  be  able  to 
interrupt  and  speak  to  the  communicator.  Besides,  an  unlimited  number  <>»  telegraphs 
and  other  instruments  for  communicating  particular  signals  may  be  included  in  the 
circuit  of  the  same  line-wire.  ,    .,     .  x-       i.i. 

2.  Another  telegraph  is  peculiarly  adapted  to  record  on  both  stations  the  message 
delivered  by  the  common  English  needle  telegraph.  Two  magnets  by  naeans  of  two  pins 
make  dots  in  two  different  lines  on  a  strip  of  paper  which  is  nioved  by  clockwork.  Dots 
on  the  upper  line  correspond  with  a  movement  of  the  needle  to  the  right,  and  dots  on 
the  lower  line  correspond  with  that  to  the  left  .  i.  j 

Instead  of  needle  telegraphs  peculiar  communicating  instruments  nnay  be  used  con- 
sisting  either  of  a  pair  of  keys  onTy,  or  of  a  complete  key-board,  which  by  pressing  down 
one  of  them  causes  the  conventional  sign  representing  the  letter  marked  on  it  to  be 

orinted  in  a  double  line  of  dots.  ,    ,  ,  t. 

*^  3.  A  double  needle  telegraph,  with  electro-magnets  and  worked  ^7  one  line-wire. 
4.  An  alarum,  by  which  intermediate  stations,  when  excluded  from  the  line-wire,  may 

be  called  into  the  circuit  ,  .  ,  ,       _       .      ,  •  «  j,« 

6.  An  alarum  with  two  large  cast-iron  bells,  which  are  placed  on  evel  crossings,  Ac., 
along  railways  and  serve  to  announce  the  departure  of  each  tram  along  the  line.  Ihe 
ffare  surrounded  by  clockwork,  which  is  released  by  a  current  of  longer  duration 

than  is  required  to  work  the  telegraphs.  ,  .      ,    .      .    .t  .^  u„  ««„*oil 

6.  An  instrument  which  is  used  to  detect  bad  insulation  in  the  gutta  percha  coated 

7  Y  galvanometer  to  test  the  insulation  of  the  line-wire,  and  another  by  which 
defects  in  the  line-wire  may  be  pointed  out,  without  leaving  the  end  stations. 

8.  Gutta  percha  coated  electric  line-wire,  which  was  first  invented  by  Mr.  Sumens, 
and  applied  by  him  on  a  large  scale,  since  1847. 

9.  An  improved  Morse's  telegraph  worked  by  secondary  power. 
TELLURIUM,  is  a  metal  too  rare  and  high-priced  to  be  used  in  the  arts. 
TERRA-COTTA,  literally  baked  clay,  is  the  name  give  to  statues,  architectural 

decorations,  figures,  vases.  Ac.,  modelled  or  cast  in  a  paste  made  of  pipe  or  potter  s  cla^  and 
a  fine-grained  colorless  sand,  from  Ryegate,  with  pulverized  potsherds^  slowly  dried  in  the 
air  and  afterward  fired  to  a  stony  hardness  in  a  proper  kiln.     See  Stonb,  Amificiai. 

TERRA  DI  SIENA,  is  a  brown  ferruginous  ochre,  employed  m  painting. 

TEST  LIQUORS.  To  reduce  an  alkaline,  acid,  or  a  neutral  saline  solution  ot  a 
certain  strength  to  one  of  any  other  strength.  Let  a  =-  the  given  strength  per  cent  of 
S  ouid  •  6  -  100 ;  0  -  the  desired  strength  ;x^the  volume  of  the  (Tiluted  solution 

Example.     Let  an  alkaline  solution  contain  40  per  cent  of  alkali :  if  it  is  to  be  reduced 

,         -       .        ao  4000        iRR.fl. 

to  one  containing  24  per  cent,  then  the  above  formula  gives   -  a;  —  —  —  lot)  o, 

hence  if  100  measures  of  the  liquid  a  be  diluted  into  166  measures,  it  will  then  contain 
^VfiS-STwe  chemical  reagents  of  any  kind,  which  indicate,  by  special  characten, 


1421 


r 

-- 

_  - 

r 

o 

--- 

1                     1 

c 

1                     I 

f 

1                     < 

c 

'  1                  '  1 

c 

1                     1 

a_u 

■  -    1                     1 

- 

°J 

• 

_ . 

--&, 

.rzs 


the  nature  of  any  substance,  simple  or  compound.     See  Assay,  the  several  metal^ 
acids,  Ac 

TEXTILE  FABRICS.    The  first  business  of  the  weaver  is  to  adapt  those  parts  of 
his  loom  which  move  the  warp,  to  the  formation  of  the  various  kinds  of  ornamental  figures 
which  the  cloth  is  intended  to  exhibit  This  subject  is  called  the  draught,  drawing  or  read- 
ing in,  and  the  cording  of  looms.     In  every  species  of  weaving,  whether  direct  or  cross, 
^e  whole  difference  of  pattern  or  effect  is  produced,  either  by  the  succession  in  which  the 
threads  of  warp  are  introduced  into  the  heddles,  or  by  the  succession  in  which  thoie  heddlos 
are  moved  in  the  working.    The  heddles  being  stretched  between  two  shafts  of  wood,  all 
the  heddles  connected  by  the  same  shafts  are  called  a  leaf;  and  as  the  operation  of  in- 
troducing the  warp  into  any  number  of  leaves  is  called  drawing  a  warp,  the  plan  of  suc- 
cession is  called  the  draught.     When  this  operation  has  been  performed  correctly,  the  next 
part  of  the  weaver's  business  is  to  connect  the  different  leaves  with  the  levers  or  treddles 
by  which  they  are  to  be  moved,  so  that  one  or  more  may  be  raised  or  sunk  by  every 
treddle  successively,  as  may  be  required  to  produce  the  peculiar  pattern.     These  connex- 
ions being  made  by  coupling  the  different  parts  of  the  apparatus  by  cords,  this  opei'ation 
is  called  the  cording.     In  order  to  direct  the  operator  in  this  part  of  his  business, 
especially  if  previously  unacquainted  with  the  particular  pattern  upon  which  he  isemployed, 
plans  are  drawn  upon  paper,  specimens  of  which  will  be  found  in  figs.  1420,  1421,  &.c. 
2^20  /J  These  plans  are  horizontal  sections  of  a  loom,  the 

jjillgM^^  heddles  being  represented  across  the  paper  at  a,  and 
"^'^''^^^^^  the  treddles  under  them,  and  crossing  them  at  right 
angles,  at  b.  In  figs.  1420  and  1421,  they  are  re- 
presented as  if  they  were  distinct  pieces  of  wood, 
those  across  being  the  under  shaft  of  each  leaf  of 
heddles,  and  those  at  the  left  hand  the  treddles. 
See  Weaving.  In  actual  weaving,  the  treddles  are 
placed  at  right  angles  to  the  heddles,  the  sinking 
cords  descending  perpendicularly  as  nearly  as  pos- 
sible to  the  centre  of  the  latter.  Placing  them  at  the 
left  hand,  therefore,  is  only  for  ready  inspection,  and 
for  practical  convenience.  At  c  a  few  threads  of  warp 
45 GIB  are  shown  as  they  pass  through  the  heddles,  and  the 
thick  lines  denote  the  leaf  with  which  each  thread  is  connected.  Thus,  in  fig.  1420,  the 
right-hand  thread,  next  to  a,  passes  through  the  eye  of  a  heddle  upon  the  back  leaf,  and  is 
disconnected  with  all  the  other  leaves;  the  next  thread  passes  through  a  heddle  on  the  second 
leaf;  the  third,  through  the  third  leaf;  the  fourth,  through  the  fourth  leaf;  and  the  fifth, 
through  the  fifth  or  front  leaf.  One  set  of  the  draught  being  now  completed,  the  weaver 
recommences  with  the  back  leaf,  and  proceeds  in  the  same  succession  again  to  the  front. 
Two  sets  of  the  draught  are  represented  in  this  figure,  and  the  same  succession,  it  is 
understood  by  weavers  (who  seldom  draw  more  than  one  set),  must  be  repeated  until  all 
the  warp  is  included.  When  they  proceed  to  apply  the  cords,  the  right-hand  part  of  the 
plan  at  h  serves  as  a  guide.  In  all  the  plans  shown  by  these  figures,  excepting  one  which 
shall  be  noticed,  a  connexion  must  be  formed,  by  cording,  between  every  leaf  of  heddles  and 
every  treddle  ;  for  all  the  leaves  must  either  rise  or  sink.  The  raising  motion  is  effected 
by  coupling  the  leaf  to  one  end  of  its  correspondent  top  lever ;  the  other  end  of  this 
lever  is  tied  to  the  long  march  below,  and  this  to  the  treddle.  The  sinking  connexion 
is  carried  directly  from  under  the  leaf  to  the  treddle.  To  direct  a  weaver  which  of 
these  connexions  is  to  be  formed  with  each  treddle,  a  black  spot  is  placed  when  a  leaf  is 
to  be  raised,  where  the  leaf  and  treddle  intersect  each  other  upon  the  plan,  and  the 
sinking  connexions  are  left  blank.  For  example,  to  cord  the  treddle  1,  to  the  back 
leaf,  put  a  raising  cord,  and  to  each  of  the  other  four,  sinking  cords ;  for  the  treddle  2, 
raise  the  second  leaf,  and  sink  the  remaining  four,  and  so  of  the  rest ;  the  spot  always 
denoting  the  leaf  or  leaves  to  be  raised.  The  figs.  1420,  and  1421,  are  drawn  for  the 
purpose  of  rendering  the  general  principle  of  this  kind  of  plans  familiar  to  those  who 
have  not  been  previously  acquainted  with  them ;  but  those  who  have  been  accustomed 
to  manufacture  and  weave  ornamented  cloths,  never  consume  time  by  representing 
cither  heddles  or  treddles  as  solid  or  distinct  bodies.  They  content  themselves  with 
ruling  a  number  of  lines  across  a  piece  of  paper,  sufficient  to  make  the  intervals  between 
these  lines  represent  the  number  of  leaves  required.  Upon  these  intervals,  they  merely 
mark  the  succession  of  the  draught,  without  producing  every  line  to  resemble  a  thread 
of  warp.  At  the  left  hand,  they  draw  as  many  lines  across  the  former  as  will  afford  «« 
interval  for  each  treddle ;  and  in  the  squares  produced  by  the  intersections  of  these  linet, 
they  place  the  dots,  spots,  or  ciphers  which  denote  the  raising  cords.  It  is  also  commoa 
to  continue  the  cross  lines  which  denote  the  treddle  a  considerable  length  beyond  the 
intersections,  and  to  mark  by  dots,  placed  diagonally  in  the  intervals,  the  order  or  sne- 


fi 


^^ 


TEXTILE  FABRICS. 


oeaaion  in  which  the  treddlea  are  to  be  pressed  down  in  weaving.  The  foracr  of  theit 
modes  has  been  adopted  in  the  remaining  fig».  to  1429;  but  to  save  room,  the  latter 
has  been  avoided,  and  the  succession  marked  by  the  order  of  the  figures  under  the 

intervals  which  denote  the  treddles.  .<.,,,  .  ^  i.    .i.         ^ 

Some  explanation  of  the  various  kinds  of  fanciful  cloths  represented  by  these  plana, 
mav  serve  further  to  illustrate  this  subject,  which  is,  perhaps,  the  most  important  of  any 
connected  with  the  manufacture  of  cloth,  and  will  also  enable  a  person  who  thoroughly 
studies  them,  readily  to  acquire  a  competent  knowledge  of  the  other  varieties  in  weaving, 
which  are  boundless.     Fig>^.  1420  and  1421  represent  the  draught  and  cording  of  th« 
two  varieties  of  tweeled  cloth  wrought  with  five  leaves  of  heddles.    The  first  is  tne  re- 
eular  or  run  tweel,  which,  as  every  leaf  rises  in  regular  succession,  while  the  rest  arc 
funk,  interweaves  the  warp  and  woof  only  at  every  fifth  interval,  and  as  the  successioa 
is  uniform,  the  cloth,  when  woven,  presents  the  appearance  of  parallel  diagonal  ines,  at 
an  aa-le  of  about  45°  over  the  whole  surface.     A  tweel  may  have  the  regularity  ol  its 
diagonal  lines  broken  by  applying  the  cording  as  in  fig,  1421.     It  wil  be  observed  ^at 
in  ^Ih  figures  the  draught  of  the  warp  is  precisely  the  same,  and  that  the  whole  differ- 
ence of  the  two  plans  consists  in  the  order  of  placing  the  spots  denoting  the  raising  cords, 
the  first  being  regular  and  successive,  and  the  second  alternate.  ,  ,       ,  „..v 

Fies  1422  and  1423  are  the  regular  and  broken  Iweels  which  may  be  produced  with 
eight  leaves.    This  properly  is  the  tweel  denominated  satin  in  ^^e^  silk^manu^^^ 


1422 


1423 


r                 1 

o 

\                 ' 

1 > 

1                 ' 

0 

'  1                  1 

o 

1                  1 

o 

1 

0 

I , 

__o U 

1                  1 

c 

m!'^5d7ff 

11346 


although  many  webi 
of  silk  wrought  with 
only  five  leaves  re- 
ceive that  appella- 
tion. Some  of  the 
finest  Florentine 
silks  are  tweelei 
with  sixteen  leaves. 


When  the  broken  tweel  of  eight  leaves  is  used,  the  effect  is  much  superior  to  what 
couU  be  produced  by  a  smaller  number;  for  in  this,  two  leaves  are  passed  in  every  in- 
terval which  gives  a  much  nearer  resemblance  to  plain  cloth  than  the  others,  /or  this 
reason  it  is  preferred  in  weaving  the  finest  damasks.  The  draught  of  the  eight-leaf 
tweel  differs  in  nothing  from  the  others,  excepting  in  the  number  of  leaves.  Ihe  diHer- 
ence  of  the  cording  in  the  broken  tweel,  will  appear  by  inspecting  the  ciphers  which 
mark  the  raising  cords,  and  comparing  them  with  those  of  the  broken  tweel  of  five 
leaves  Fit;.  1424  represents  the  draught  and  cording  of  striped  dimity  of  a  tweel  of 
five  leaves.     This  is  the  most  simple  species  of  fanciful  iweeling.     It  consists  of  ten 


1424 


leaves,  or  double  the  number  of  the  common  tweel. 

These  ten  leaves  are  moved  by  only  five  treddles,  in 

the  same  manner  as  a  common  tweel.     The  stripe  is 

formed  by  one  set  of  the  leaves  flushing  the  warp, 

I  - — 1— -  fn  M  ||°|"i;l°LI     and  the  other  set,  the  woof.     The  figure  represents 

i  '  I     : -pet-- "^11      a  stripe  formed  by  ten  threads,  alternately  drawn 

'■111  rUiry°lll3     through  each  ofthe  two  sets  of  leaves.     In  this  case, 

,M94,si22^^      ^^^  ^^^.p^  ^j  ^^^  intervals  will  be  equally  broad, 

and  what  is  the  stripe  upon  one  side  of  the  cloth,  will  be  the  interval  upon  the  other, 
and  rice  versa.  But  great  variety  of  patterns  may  be  introduced  by  drawing  the  warp 
in  greater  or  smaller  portions  through  either  set.  The  tweel  is  of  the  regular  kind, 
but  may  be  broken  by  placing  the  cording  as  in  fig.  1421.  It  will  be  observed  that 
the  cording-maiks  of  the  lower  or  front  leaves  are  exactly  the  converse  of  the  other 
set-  for  where  a  raising  mark  is  placed  upon  one,  it  is  marked  for  smkmg  in  the  other; 
that  is  to  say,  the  mark  is  omitted ;  and  all  leaves  which  sink  m  the  one,  are  marked 
for  raising  in  the  other:  thus,  one  thread  rises  in  succession  m  the  back  set,  and 


1425 


four  sink ;  but  in  the  front  set,  four  rise,  and  only 
one  sinks.  The  woof,  of  course,  passing  over  the 
four  sunk  threads,  and  under  the  raised  one,  in  the 
first  instance,  is  flushed  above ;  but  where  the  re- 
verse takes  place,  as  in  the  second,  it  is  flushed 
below ;  and  thus  the  appearance  of  a  stripe  is  formed. 
The  analogy  subsisting  between  striped  dimity  and 
dornock  is  so  great,  that  before  noticing  the  plan  for 
fancy  dimity,  it  may  be  proper  to  allude  to  the  dornock,  the  pUn  of  which  is  represented 

The  drau«^ht  of  dornock  is  precisely  the  same  in  every  respect  with  that  of  striped 
dimitv  It  ''also  consists  of  two  sets  of  tweeling-heddles,  whether  three,  four,  or  hve 
leav-es  are  used  for  each  set.  The  right  hand  set  of  treddles  is  also  corded  exactly  in  the 
same  way  as  will  appear  by  comparing  them.    But  as  the  dimity  is  a  continued  stripe 


i  ^  .3  ^  J 


TEXTILE  FABRICS. 

from  the  be^nning  to  the  end  of  the  web,  only  five  treddles  are  required  to  move  tea 

leave*    The  dornock  being  checker-work,  the  weaver  must  possess  the  power  of  pe- 

Tersing  this  at  pleasure.    He  therefore  adds  five  more  treddles,  the  cording  of  which  i« 

exactly  the  reverse  of  the  former;  that  is  to  say,  the  back  leaves,  in  the  former  case, 

having  one  leaf  raised,  and  four  sunk,  have,  by  working  with  these  additional  treddles, 

one  leaf  sunk  and  four  leaves  raised.     The  front  leaves  are  in  the  same  manner  reversed, 

and  the  mounting  is  complete.     So  long  as  the  weaver  continues  to  work  with  either 

•ct,  a  stripe  will  be  formed,  as  in  the  dimity;  but  when  he  changes  his  feet,  from  one  set 

to  the  other,  the  whole  effect  is  reversed,  and  the  checkers  formed.     The  dornock  paU 

tern  upon  the  design-paper,  yig.  1425,  may  be  thus  explained:  let  every  square  of  the 

design  represent  five  threads  upon  either  set  of  the  heddles,  which  are  said  by  weavers 

to  be  once  over  the  draught,  supposing  the  tweel  to  be  one  of  five  leaves;  draw  three 

parallel  lines,  as  under,  to  form  two  intervals,  each  representing  one  of  the  sets ;  the 

draught  will  then  be  as  follows : — 


1 


The  above  is  exactly  so  much  of  the  pattern  as  is  there  laid  down,  to  show  its  ap- 
pearance ;  but  one  whole  range  of  the  pattern  is  completed  by  the  figure  1,  nearest  to 
the  right  hand  upon  the  lower  interval  between  the  lines,  and  the  remaining  fic^ures, 
nearer  to  the  right,  form  the  beginning  of  a  second  range  or  set.  These  are  to  be  re- 
peated in  the  same  way  across  the  whole  warp.  The  lower  interval  represents  (he  five 
front  leaves ;  the  upper  interval,  the  five  back  ones.  The  first  figure  4,  denotes  that  five 
threads  are  to  be  successively  drawn  upon  the  back  leaves,  and  this  operation  repeated 
four  times.  The  first  figure  4,  in  the  lower  interval,  expresses  that  the  same  is  to  be 
done  upon  the  front  leaves;  and  each  figure,  by  its  diagonal  position,  shows  how  often, 
and  m  what  succession,  five  threads  are  to  be  drawn  upon  the  leaves  which  the  interval 
in  which  it  is  placed  represents. 

Dornocks  of  more  extensive  patterns  are  sometimes  woven  with  3,  4,  5,  and  even  6 
sets  of  leaves;  but  after  the  leaves  exceed  15  in  number,  they  both  occupy  an  incon- 
venient space,  and  are  very  unwieldy  to  work.  For  these  reasons  the  diaper  harness  ia 
m  almost  every  instance  preferred. 

Fig.  1426  represents  the  draugj;it  and  cording  of  a  fartciful  species  of  dimity    in 
which    it    will  be  observed  that  the  warp  is   not    drawn    directly  from   the    back 
J426  to  the  front  leaf,  as  in  the  former  examples;    bul 

when  it  has  arrived  at  either  external  leaf,  the  draught 
is  reversed,  and  returns  gradually  to  the  other.  The 
same  draught  is  frequently  used  in  tweeling,  when  it 
is  wished  that  the  diagonal  lines  should  appear  upon 
the  cloth  in  a  zigzag  direction.  This  plan  exhibits 
the  draught  and  cording  which  will  produce  the  pat- 

ti.o  o«.,o..o  1  J  u  .u  •  *^^"  "P®'*  ^^^  design-paper  in  fig.  1420,  a.  Were  all 
the  squares  produced  by  the  intersection  of  the  lines  denoting  the  leaves  and  treddles 
vvhere  the  raised  dots  are  placed,  filled  the  same  as  on  the  design,  they  would  produce 
the  effect  of  exactly  one  fourth  of  that  pattern.  This  is  caused  by  the  reversing  of  the 
draught,  which  gives  the  other  side  reversed  as  on  the  design ;  and  when  all  the  treddles 
fi-om  1  to  16,  have  been  successively  used  in  the  working,  one  half  of  the  pattern  will 
become  complete  The  weaver  then  goes  again  over  his  treddles,  in  the  reversed  order 
Fri^PwT-\T  V^.K^"  ^^'7"^"  '^'^  other  half  of  the  pattern  will  be  completed. 

iZ  ^,  th  }  '^L""^  ^A^  ^";^^"-  *^  ^^^  ^^'»^"'  '^  ''  ^^^y*  ^»»^"  *  <J^^i««  is  given,  to 
make  out  the  draught  and  cording  proper  to  work  it;  and  when  the  cording  is  given  to 
see  Its  enect  upon  the  design.  ^        * 

Fig.  1427  represents  the  draught  of  the  diaper  mounting,  and  the  cording  of  the  front 
'^"^  leaves,  which  are  moved  by  treddles.     From  the  plan. 

It  \yill  appear  that  5  threads  are  included  in  every 
mail  of  the  harness,  and  that  these  are  dra^Ti  in 
single  threads  through  the  front  leaves.  The  cording 
forms  an  exception  to  the  general  rules,  that  when  one 
or  more  leaves  are  raised,  all  the  rest  must  be  sunk; 

.        j7^^—  ,  ^®'"»'^  this  instance,  one  leaf  rises,  one  sinks,  and  three 

remain  stationary.     An  additional  mark,  therefore,  is  used  in  this  plan.     The  dots,  as 

formerly,  denote  raising  cords ;  the  blanks,  sinking  cords ;  and  where  the  cord  is  to  be 

totally  omitted,  the  cross  marks  X  are  placed. 

Fig.  1438  is  the  draught  and  cording  of  a  spot  whose  two  sides  are  similar,  but  re- 


it 


824 


TEXTILE  FABRICS. 


▼ersed  That  upon  the  plan  forms  a  diamond,  similar  to  the  one  drawn  npon  the  d<^ 
rien  paper  in  the^diagram.  but  smaller  in  size.  The  draught  here  is  reversed,  as  in  ho 
ZitTpla  "and  the'treading  is  also  to  be  reversed  after  arnv.oga^^^^^^^  T^av  ng 
diamond  Like  it,  too,  the  raising  marks  form  one  fourth  of  the  pattern.  In  weaving 
spo^  ?hey  are  commonly  placed ''at  intervals,  with  a  port.on  of  plam  c\oth  between 
Tem  and  in  alternate  rows,  the  spots  of  one  row  being  between  those  of  the 
oJh™;  But  as  intervals  of  plain  cloth  must  take  place,  both  by  the  warp  and  woof  2 
?eaves  are  added  for  that  purpose.  The  front,  or  ground  leaf,  includes  every  second 
Arlad  of  the  whole  warp ;  the  second,  or  plain  leaf,  that  part  which  forms  the  inter- 
vals  4  the  warp.  The  remaining  leaves  fornx  the  spots  ;  the  first  six  being  alio  led  ta 
Te  row  of  spots,  and  the  second  six  to  the  next  row;  where  each  spot  ism  the  centxebe- 
"     "'    »       '  ^^ggj^  ^Yie  former.     The  reversed  draught  of  the  first 

is  shown  entire,  and  is  succeeded  by  12  threads  of 
plain.  One  half  of  the  draught  of  the  next  row  is 
then  t'iven,  which  is  to  be  completed  exactly  like  the 
first,  "and  succeeded  by  12  threads  more  of  plain ; 
when,  one  set  of  the  pattern  being  finished,  the  same 
succession  is  to  be  repealed  over  the  whole  warp. 
As  spots  are  formed  by  inserting  woof  of  coarser 
dimensions  than  that  which  forms  the  fabric,  every  second  thread  only  is  allotted  for  the 
spoltin-.  Those  included  in  the  front,  or  ground  leaf,  are  represented  by  lines,  and  ine 
spot  threads  between  them,  by  marks  in  the  intervals,  as  in  the  othff/'^ns. 

The  treddles  necessary  to  work  this  spot  are,  in  number,  14.  Of  these,  the  two  m  ine 
cv^are  a,  6,  when  pressed  alternately,  will  produce  plain  cloth  ;  for  6  raises  the  [ront  le^> 
which  includes  half  of  the  warp,  and  sinks  all  the  rest ;  while  a  exactly  reverses  t^e  opera- 

lion.  The  spol-lreddles  on  the  right  hand  work  Uie 
row  contained  in  the  first  six-spot  leaves  ;  and  those 
upon  the  left  hand,  the  row  contained  in  the  second 
six.  In  working  spots,  one  thread,  or  shot  of  si)Olling- 
woof,  and  two  of  plain,  are  successively  inserted,  by 
means  of  two  separate  shuttles. 

Dissimilar  spots,  are  those  whose  sides  are  q.*ile 

different  from  each  other.     The  draught  only  of  these  is  represented  by  Jig.   1429. 
The  cordin?  depends  entirely  upon  the  figure.  ,    r  j   »  „„.>,or       if  thP 

Fig.  1430   represents  any   solid   body  composed  of  parts  lashed   together.      11   tne 
darkened  squares  be  supposed  to  be  beams  of  wool,  connected  by  cordage,  they  wi  1 
give  a  precipe  idea  of  textile  fabric.     The    beams  cannot    come  into   aciua    contact, 
because,  if  the  lashmg  cords  were  as  fine  even  as  human  hairs,  they  must  still  require 
'  1430  space.      The    thickness    is    that    of   one 

beam    and  one  cord;  but    if   the    cords 
touch   each    other,  it  may    then   be   one 

beam    and     two    cords;     but    it    is    not 

possible   in  practical  weaving  to  bring  every   thread  of  weft  into  actual  contact.    Il 

may  therefore  be  assumed,  that  the  thickness  is  equal  to  the  diameter  of  one  thread  ot 

the  warp,  added  to  that  of  one  yarn  of  the  weft ;  and  when  these  are  equal,  the  thick- 

-  .„.  ness  of  the  cloth  is  double  of  that  diame- 

^^^^  ler.     Denser  cloth  woukl  not  be  suffi- 

^      ciently  pliant  or  flexible. 
^         Fig.  1431  is  a  representation  of  a  sec- 
lion  of  cloth  of  an  open  fabric,  where  the  round  dots  whicn  represent  the  warp  are  placed 
at  a  considerable  distance  from  each  other. 

Fig.  1432  may  be  supposed  a  plain  fabric  of  that  description  which  approaches  the 
most  nearly  to  any  idea  we  can  form  of  the  most  dense  or  close  contact  of  which  yarn 
can  be  made  susceptible.     Here  the  warp  is  supposed  to  be  so  tightly  stretched  in 

]432  the   loom    as   to  retain   entirely  the 

^^^-r^^^-^      parallel  state,  without  any  curvature, 

^^^Mi       and  the   whole   flexure    is    therefore 

given    to  the  woof.    This  mode  of 

weaving  can  never  reallv  exist ;  but  if  the  warp  be  sufficiently  strong  to  bear  any  tight 

stretching,  and  the  woof  be  spun  very  soft  and  flexible,  something  very  near  it  may  be 

produced.     This  way  of  making  cloth  is  well  fitted  for  those  goods  which  require  to 

give  considerable  warmth ;  but  they  are  sometimes  the  means  of  very  gross  fraud  and 

imposition;  for  if  the  warp  is  made  of  very  slender  threads,  and  the  woof  of  slackly 

twisted  cotton  or  woollen  yarn,  where  the  fibrils  of  the  stuff,  being  but  slightly  brought 

into  contact,  are  rough  and  oozy,  a  great  appearance  of  thickness  and  strength  may  be 

given  to  the  eye,  when  the  cloth  is  absolutely  so  flimsy,  that  it  may  be  torn  asunder  as 

easily  as  a  sheet  of  writing-paper.    Many  frauds  of  this  kind  are  practised; 


TEXTILE  FABRICS. 


825 


..  f'J/5'-  1433  13  given  a  representation  of  the  position  of  a  fabric  of  cloth  in  section,  as 
It  IS  in  the  loom  before  the  warp  has  been  closed  upon  the  woof,  which  still  appears  as  a 

I'^^S  straight  line.      This  figure   may  use- 

A  a  /^  f**''y  illustrate  the  direction  and  ratio 

■^^^=^     of  contraction  which  must  unavoidably 
"V       take   place  in  every  kind  of  cloth,  ac- 
,.     ,.         .         ^   ,  irf        is   '•  cording  to  the  density  of  the  texture, 

the  dimensions  of  the  threads,  and  the  description  of  the  cloth.     Let  a,  b,  represent  on« 
thread  of  woof  completely  stretched  by  the  velocity  of  the  shuttle  in  passing  between 
ine  inreaos  of  warp  which   are  represented  by  the  round  dots  I,  2.  Ac,  and  those 
distinguished  by  8,  9,  &c.     When  these  threads  are  closed  by  the  operation  of  the 
neuaies  to  form  the  inner  texture,  the  first  tendency  will  be  to  move  in  the  direction 
i,  0,  I,  b,  &c.,  for  those  above,  and  in  that  of  8  a,  9  a,  &c.,  for  those  below ;    but  the 
contraction  for  a,  b,  by  its  deviation  from  a  straight  to  a  curved  line,  in  consequence 
01  the  compression  of  the  warp  threads  1  6,  2  6,  &c.,  and  1  a,  2  a,  &c.,  in  closin?,  will 
produce,  by  the  action  of  the  two  powers  at  right  angles  to  each  other,  the  oblique  or 
diagonal  direction  denoted  by  the  lines  1,  8— 2,  9,  to^the  left,  for  the  threads  above 
and  that  expressed  by  the  lines  2,  8—3,  9,  &c.,  to  the  right,  for  the  threads  below' 
xxow,  as  the  whole  deviation  is  produced  by  the  flexure  of  the  thread  a,  b,  if  a  is  sup- 
posed to  be  placed  at  the  middle  of  the  clolh,  equidistant  from  the  two  extremities  or 
selvages,  as  they  are  called  by  weavers,  the  thread  at   1  may  be  supposed  to  move  really 
m  the  direction  1  b,  and  all  the  others  lo  ai)proach  to  it  in  the  directions  represented 
Whilst  those  to  the  right  would  apjiroach  in  the  same  ratio,  but  the  line  of  approxima- 

1434  lion  would  be  inverted.     Fig.  1434 

9'm^W^^W^^^^ii^^^0^i:^^%^<^^^^^  for  lawns,  muslins,  and  the  middle 
kinu  ol  goods,  the  excellence  of  whicli  neither  consists  m  the  greatest  strength,  nor  in 
the  greai?<;t  lransi)arency.     It  is  entirely  a  medium  bet  ween  ^g.~  1431  andyjg.^1432. 

In  the  eflbit?  to  give  great  strength  and  thickness  lo  cloth,  it  will  be  obvious  that  the 
common  mode  of  ^vavinff,  by  c<»nstant  intersection  of  warp  and  woof,  although  it  may 
be  perhaps  the  best  which  can  be  devised  for  the  former,  presents  invincible  obstruc- 
tions to  the  latter,  beyond  a  certain  limit.  To  remedy  this,  two  modes  of  weavin*'  are 
in  conrimori  use,  which,  while  they  add  to  the  power  of  compressing  a  great  quantify  of 
materials  in  a  small  compass,  possess  the  additional  advantage  of  affording  much  facility 
for  adding  ornament  to  the  superficies  of  the  fabric.  The  first  of  these  is  double  cloth 
or  two  webs  woven  together,  and  joined  by  the  oi>eiation.      This  is  chiefly  used  for 

1435  carpets;    and    its    geometrical    prin- 

ciples aie  entirely  the  same  as  those 
,    .  ,  .        .  *         ....,,  °^  P^^'**   Q\oih,  supposing    the   webs 

to  be  sewed  together.    A  section  of  the  cloth  will  be  found  in^ig.  1435.    See  Carpet 
Of  the  simplest  kind  of  iweeled  fabrics,  a  section  is  given  in  fig.  1436 
The  great  and  prominent  advantage  of  the  tweeled  fabric,  in 'point  of  texture,  arises 
from  the  facility  with  which  a  very  great  quantity  of  materials  may  be  put  closely  to- 

gether.    In  the  figure,  the  warp  is 


represented  by  ihe  dots  in  the  same 
slraiffht  line  as  in  the  plain  fabrics ; 
but  if  we  consider  the  direction  and 
ratio  of  contraction,  upon  principles 


h    1436 


sunilar  to  those  laid  down  in  the  explanation  given  of;^g.  TlierwrslTall  rea^iirdTscovS 

the  very  diflerenl  way  in  which  the  tweeled  fabric  is  affected  ^  discover 

When  the  doited  lines  are  drawn  at  a,  b,  c,  d,  their  direction  of  contraction,  instead 

?h.  "'r  ??"  r''^  '"'''??  ^'  °^^^''"^^"  ^^''''^'  ''  «"^y  "P«"  every  fifth  thread,  and 
Ipnt^  r  .k'"?'"*^^'  T".^^  consequently  be,  to  bring  the  whole  into  the  form  repr^ 
sented  by  the  lines  and  dotted  circles  at  a,  6,  c,  d.  In  point,  then,  of  thickness  from 
the  upper  to  the  under  superficies,  it  is  evident  that  the  whol'e  fabHc  has  increased  S 
the  ratio  of  nearly  three  to  one.  On  the  other  hand,  it  will  appear,  that  four  thread 
or  cylinders  being  thus  put  together  in  one  solid  mass,  mighl  be  supposed  only  onj 
£  nt  S  r»ii  ^  ^  strands  of  a  rope  before  it  is  twisted;  but,  to  remedy  this,  the  thread 
being  shifted  every  time,  the  whole  forms  a  body  in  which  much  aggregate  matter  is 
compressed;  but  where,  being  less  firmly  united,  the  accession  of  strength  acquired  by  the 
accumulation  of  materials  is  partially  counteracted  by  the  want  of  equal  firmness  of 
junction. 

The  second  quality  of  the  Iweeled  fabric,  susceptibility' of  receiving  ornament,  arises 

1437  from  its  capability  of  being  inverted  at 

m     pleasure,  as  in  fig.  1437.    In  this  figure 

^^     we  have,  as  before,  four  threads,  and  one 

alternately    intersected;    but   here    the 


TEXTILE  FABRICS. 


W 


li 


and  adds  even 


ength 
1488 


89& 

ib«r  tbreads  marked  1  and  i  are  under  the  woo^  whUe  those  marked  8  and  4  art 

above.  , .   ,    -  tweeled  work  which  produces  an  ornamental  effect, 

m  1438  '«Pf«««^^^t**i'?^f  .^^^^^  for  BB  nccumulation  of  matter  can  be 

r.d  «dds  even  to  the  strength  of  a  fabric,  in  ^^^^.^^^^^  -^  ^^^^  ^-^y^^^    The  figure 

represents  a  piece  of  velvet  cut  m 
section,  and  of  that  kind  which,  be- 

. -^ ^         ^        ,-  ing  woven  upon  a  tweeled  ground, 

k  known  by  the  name  of  Genoa  velvet     1st,  Because,  by  combining  a  great  quantitj 
rf  matrrfal  in  a  small  compass,  they  afford  great  warmth.  ^2d.  From  the  great  resist- 
L^TwhTch  hey  oTpose  to  Sternal  friction,  they  are  very  durable.     And  3d.  Because 
^^m  The  very  natur^of  the  texture,  they  afford  the  finest  means  of  rich  ornamental  dec»>. 

'^tZ  use  of  velvet  cloths  in  cold  weather  is  a  sufficient  proof  of  the  truth  of  the  first. 
Th?manufacture  of  pl^^^^^^^  corduroy,  and  other  stuffs  for  the  dress  of  those  exposed  to  the 
IddTnts  of  la^^^^^^^^^^^  the  second;  and  the  ornamented  velvets  and 

Wilton  caroetins  are  demonstrative  of  the  third  of  these  positions. 

In  tie  figure  the  diagonal  form  which  both  the  warp  and  woof  of  cloth  assume,  is  very 
a^rttf?omlhe  illness  of  the  scale.  Besides  what  this  adds  to  Jhe Jtrength  of^he 
S,  the  flushed  part,  which  appears  interwoven  at  the  ^^^^ly  shaded  int^^^^^^  1^  2  &c., 
forms,  when  finished,  the  whole  covering  or  upper  surface.  The  prmciple,  in  so  lar  as 
regards  texture,  is  entirely  the  same  as  any  other  tweeled  fabric. 

fS.  1122,  which  represents  corduroy,  or  king's  cord,  ;s  merely  f"ped  velvet  The 
princfple  is  the  same,  and  the  figure  shows  that  t;^^  ^  ^^^^^^^^^  S^; 

1439  ^^^^  ^Yilch  are  of  the  most  flimsy  and 

,open  description  of  texture;    those  in 
which  neither  strength,  warmth,  nor  du- 
rability is  much  required,  and  of  which 
nnenness  and  transparency  are  the  chiel  recommendations. 
^T^^riS  r^prese^nts  colimon  .auze,^_or /».u    a -^f-ce  very  ^^^^^^^^^^^ 


TEXTILE  FABRICS. 


827 


purposes. 


The  essential  difference  between  this  description  of  cloth  and  all  others,  con- 
ine  essenu  ^.^^^  .^  ^^^  ^^^^  ^^.^^  ^^^^^^  ^^  twisted 

1440  like  a  rope  during  the  operation  of  weav- 

and  hence  it  bears  a  considerable 
The  twining  of  gauze  is 


ing, 

analogy  to  lace. 


not  continued  in  the  same  direction,  but  is  alternately  from  right  to  left,  ^nd  vice  versa, 
Mween  every  intersection  of  the  woof.  The  fabric  of  gauze  is  always  open,  flimsy,  and 
Uarparent;^but,  from  the  turning  of  the  warp,  it  possesses  a.^.uncommon  degree  of 
strength  and  tenacity  in  proportion  to  the  quantity  of  material  which  i  contains.  This 
qualify,  together  with  the' transparency  of  the  fabric,  renders  it  Peculiarly  adapted  for  or- 
Samental  purposes  of  various  kinds,  particularly  for  flowering  or  figuring,  fi  her  in  the 
him,  or  by  the  needle.  In  the  warp  of  gauze,  there  arises  a  much  greater  degree  of 
c^nT  action  during  the  weavinsr,  than  in  any  other  species  of  cloth ;  and  this  »s  produced 
i^  the  turning,  the  twisting  between  every  intersection  of  weft  amounts  precisely  to  one 
Slee  revolution  of  both  Threads ;  hence  this  difference  exists  between  ih^f  and  every 

other  species  of  weaving,  namely,  that  the  one 

l'*'*^  thread  of  warp  is  always  above  the  woof,  and 

rf^^sa^^es^aa^^s^pss^sa^^   jj^g  contiguous  thread  is  always  below. 

Fig.  1124  represents  a  section  of  another  species  of  twisted  cloth,  which  is  known  by 
the  name  of  catgut,  and  which  differs  from  the  gauze  on  y  by  being  ^"^jected  to  a  greater 
degree  of  twine  in  Weaving;  for  in  place  of  one  revolution  between  fa^h  intersection  a 
resolution  and  a  half  is  always  given;  and  thus  the  warp  is  alternately  above  and  below, 

'^Fie^lk  is"a\Sp^ficIarrepresentation  of  the  most  simple  kind  of  ornamental  net-work 
produced  in  the  loom.  It  is  called  a  whip-net  by  weavers,  who  use  the  terra  whip  for 
*^*  any  substance  interwoven  in  cloth  for 

ornamental  purposes,  when  It  is  dis- 
tinct from  the  ground  of  the  fabric. 
In  this,  the  difference  is  merely  ia 
the  crossing  of  the  warp;  for  it  is 
very  evident  that  the  crossings  at  1, 
2,  3,  4,  and  5,  are  of  different  threads 
from  those  at  6,  7,  8,  and  9. 
Fiit  1126  represents,  superficially,  what  is  called  the  mail-net,  and  is  merely  a  combi- 
ItuiLf  conJSrgauze  ^^  the  whip-net  in  the  same  fabric.    The  gauze  here  beang  in 


1^^  the  same  direction  as  the  dotted  line 

in  the  former  figure,  the  whole  fabric 
is  evidently  a  continued  succession  of 
right-angled  triangles,  of  which  the 
woof  forms  the  basis,  the  gauze  part 

,  the  perpendiculars,  and  the  whip  part 

the  hypotenuaea     The  contraction  here  being  very  different,  it  is  necessary  that  the 
gauze  and  whip  parts  should  be  stretched  upon  separate  beams. 

In  order  to  design  ornamental  figures  upon  cloths,  the  lines  which  are  drawn  from  the 
top  to  the  bottom  of  the  paper  may  be  supposed  to  represent  the  warp ;  and  those  drawa 
Across  the  woof  of  the  web ;  any  number  of  threads  being  supposed  to  be  included  be- 
tween every  two  lines.  The  paper  thus  forms  a  double  scale,  by  which,  in  the  first  in- 
stance, the  size  and  form  of  the  pattern  may  be  determined  with  great  precision  •  and 
the  whole  subsequent  operations  of  the  weaver  regulated,  both  in  mounting  and  working 
his  loom.  To  enable  the  projector  of  a  new  pattern  to  judge  properly  of  its  effect? 
when  transferred  from  the  paper  to  the  cloth,  it  will  be  essentially  necessary  that  he 
Bhould  bear  constantly  in  his  view  the  comparative  scale  of  magnitude  which  the  design 
will  bear  m  each,  regulating  his  ideas  always  by  square  or  superficial  measuremenL 
Ahus,  in  the  large  design,  fg.  1444,  representing  a  bird  perched  upon  the  branch  of  a 
tree  It  will  be  proper,  m  the  first  place,  to  count  the  number  of  spaces  from  the  point 
of  the  bill  to  the  extremity  of  the  tail ;  and  to  render  this  the  more  easy  it  is  to  be 
observed  that  every  tenth  line  is  drawn  considerably  bolder  than  the  others.  This 
number  in  the  design  is  135  spaces.  Counting  again  from  the  stem  of  the  branch  to 
the  upper  part  of  the  bird's  head,  he  will  find  76  spaces.     Between  these  spaces,  there- 


1444 


fore,  the  whole  superficial  measure  of  the  pattern  is  contained.    By  the  measure  of  the 

lT\nlt\  lVM7\'r^  ""l'^  ^  ^r""!  «^"^P^^^«'  -^<^  ^"^  ^^  foundTbe  nearly 
6^«j  inches  in  length  by  8/_  inches  in  breadth.     Now,  if  this  is  to  be  woven  in  a  reed 

containing  800  intervals  in  37  inches,  and  if  every  interval  contains  five  threads  sup- 
Td  ?h^htT»,^<;°.l^-^'^'"^  ^V'y  ^^^  P*^^"^^  '^^^^^  the  length  will  be  624  £ch£ 
nLrlv  nf  th!  i     ^^A'  ""''^''  °'*'^^ '  '^  ^^^^  ^^^  %"»"^  "P«°  ^he  cloth  Would  be  ve^ 

Lstea^d  of  an  IZ'ttZT'"''' "'  '^^'  T^  '^'  P"P^^ '  ^"^  ^^  »  '  200  reed  were  ^ 
instead  of  an  800,  the  dimensions  would  be  proportionally  contracted. 

A  correct  idea  being  formed  of  the  design,  the  weaver  may  proceed  to  mount  his 
loom  according  t«    he  pattern ;  and  this  is  done  by  two  perso^nfre  of  whTm  tok^ 
T  ^^tAT^""  instructions  necessary  for  the  other  to  follow  in  tying  hfs  clrds. 
rzg.  1445  IS  a  representation  of  the  most  simple  species  of  table-line^n.  wS  merely 


1446 


an  imitation  of  checker-work  of  various  sizes :  and  is  known  in  Scotland  where  ihm 


828 


TEXTILE  FABRICS. 


TEXTILE  MANUFACTURES. 


829 


\   ! 


1446 


extent  of  the  design,  and  the  means  by  which  it  is  executed.  Fig.  1446  is  a  design  fvf 
a  border  of  a  handkerchief  or  napkin,  which  may  be  executed  either  in  the  manner  ^J 
damask,  or  as  the  spotting  is  practised  in  the  lighter  fabrics. 

Textile  fibres  condensed.  Mr.  John  Mercer's  novel  plan  of  transforming  cotton  and 
flax  into  fibres  of  a  fine  silky  texture,  while  their  strength  and  substance  are  increased, 
has  recently  excited  much  interest.  He  subjects  them  to  the  action  of  caustic  alkaline 
lye,  sulphuric  acid,  or  to  solution  of  chloride  of  zinc,  of  such  strength  and  at  such  a 
temperature  as  produces  certain  remarkable  changes  in  them,  quite  the  reverse  of  what 
most  people  would  have  expected.  The  mode  of  operating  according  to  this  invention, 
upon  cloth  made  wholly  or  partially  of  any  vegetable  fibres  and  bleached,  is  as  follows: 
— The  cloth  is  passed  through  a  padding  machine  charged  with  caustic  soda  or  caustic 
potash  at  60°  or  70°  of  Twaddle's  hydrometer,  at  the  common  temperature  of  the  atmo- 
sphere (say  60°  Fahr.  or  under) ;  then,  without  being  dried,  it  is  washed  in  water;  and, 
after  this,  it  is  passed  through  dilute  sulphuric  acid,  and  washed  again.  Or  the  cloth 
Is  conducted  over  and  under  a  series  of  rollers  in  a  cistern  containing  caustic  soda  or 
caustic  potash  at  40°  to  50°  Twaddle,  at  the  ordinary  temperature  (the  last  two  rollers 
being  set  so  as  to  squeeze  the  excess  of  soda  or  potash  back  into  the  cistern) ;  and  then 
it  is  passed  over  and  under  rollers  placed  in  a  series  of  cisterns,  which  are  charged  at 
the  commencement  of  the  operation  with  water  only ;  so  that  when  the  cloth  arrives 
at  the  last  cistern,  nearly  all  the  alkali  has  been  washed  out  of  it  After  the  cloth  has 
either  gone  through  the  padding  machine  or  through  the  cisterns,  it  is  washed  in  water, 
passed  through  dilute  sulphuric  acid,  and  again  washed  in  water. 

When  grey  or  unbleached  cloth,  made  from  the  above  mentioned  fibrous  material,  is 
to  be  treated,  it  is  first  boiled  or  steeped  in  water,  so  as  to  wet  it  thoroughly ;  then 
most  of  the  water  is  removed  by  the  squeezer  or  hydro-extractor;  and,  after  this,  it  is 
passed  through  the  soda  or  potash  solution,  <kc.,  as  before  subscribed. 

Warps,  either  bleached  or  unbleached,  are  treated  in  the  same  manner ;  but,  after 
passing  through  the  cistern  containing  the  alkali,  they  are  passed  through  squeezers  or 
through  a  hole  in  a  metal  plate,  to  remove  the  alkali;  and  then  the  warps  are  con- 
ducted through  the  water  cisterns,  "  soured,"  and  washed,  as  before  subscribed. 

When  thread  or  hank  yarn  is  to  be  operated  upon,  the  threads  or  yarns  are  im- 
mersed in  the  alkali  and  then  wrung  out  (as  is  usually  done  in  sizing  or  dyeing  them); 
and  afterwards  they  are  subjected  to  the  above-mentioned  operations  of  washing, 
souring,  and  washing  in  water.  ^  j   •    • 

When  any  fibre  in  the  raw  state,  or  before  it  is  manufactured,  is  to  be  treated,  it  is 
first  boiled  m  water,  and  then  freed  from  most  of  the  water  by  the  hydro-extractor  or 
a  press;  after  which,  it  is  immersed  in  the  alkaline  solution,  and  the  excess  of  alkali 
is  removed  by  the  hydro-extractor  or  a  press ;  then  it  is  washed  in  water,  soured  with 
dilute  sulphuric  acid,  and  washed  again ;  and  finally  the  water  is  removed  by  the 
hydro-extractor  or  a  press. 

The  following  are  the  effects  produced  by  the  above  operations  upon  cloth  made  of 
vegetable  fibrous  material,  either  alone  or  mixed  with  animal  fibrous  material : — the 
cloth  will  have  shrunk  in  length  and  breadth,  or  have  become  less  in  ita  external  di- 
mensions, but  thicker  and  closer ;  so  that  by  the  chemical  action  of  caustic  soda  or 
caustic  potash  on  cotton  and  other  vegetable  fabrics,  an  effect  will  be  produced  some- 
what analogous  to  that  which  is  produced  on  woollen  by  the  process  of  fulling  or  mill- 
ing ;  the  cloth  will  likewise  have  acquired  greater  strength  and  firmness, — greater  force 
being  requirei  to  break  each  fibre, — it  will  be  found  to  have  become  heavier  than  it 
was  previously  to  being  acted  upon  by  the  alkali ;  if  in  both  cases  it  be  weighed  at  the 
temperature  of  60°  Fahr.,  or  under.  It  w^l  also  have  acquired  greatly  augmented  and 
improved  powers  of  receiving  colors  in  printing  and  dyeing. 

The  effects  resulting  from  the  above  treatment  of  the  vegetable  fibre,  in  any  of  its 
various  stages,  before  it  is  made  into  cloth,  will  be  readily  understood  from  the  state- 
ment of  th^  effects  produced  on  cloth,  composed  of  such  fibre,  by  treating  it  according 
to  this  invention. 

Secondly,  the  patentee  employs  diluted  sulphuri<f  acid,  at  105°  Twaddle,  and  at  60" 
Fahr.  or  under,  instead  of  caustic  soda  or  caustic  potash,  the  operation  being  the  same 
as  when  soda  or  potash  is  used,  except  the  last  souring,  which  is  now  unnecessary.     ' 


Tliirdly,  the  patentee  uses  a  solution  of  chloride  of  zinc,  at  14*°  Twaddle,  and  from 
160°  to  160°  Fahr.,  instead  of  the  soda  or  potash,  and  in  the  same  manner. 

When  operating  on  mixed  fabrics,  composed  partly  of  vegetable  fibres  and  partly  of 
silk,  wool,  or  other  animal  fibres,  such  as  delaines,  it  is  preferred  that  the  strength  of 
the  alkali  should  not  exceed  40°  Twaddle,  nor  the  temperature  be  above  50°  Fahr., 
lest  the  animal  fibre  should  be  injured. 

The  apparatus  and  the  temperature  and  strength  of  the  soda  or  potash,  sulphuric 
acid,  or  chloride  of  zinc  solution,  may  be  varied  to  a  considerable  extent,  and  will  pro- 
duce proportionate  effects ;  for  instance,  the  soda  or  potash  may  be  used  at  a  strength 
even  as  low  as  20°  Twaddle,  and  still  give  improved  properties  to  cotton,  Ac,  for  re- 
ceiving colors  in  printing  and  dyeing,  particularly  if  the  temperature  be  low ;  for  the 
lower  the  temperature,  the  more  effectually  the  soda  or  potash  acts  on  the  fibrous  ma- 
terial. The  patentee  does  not,  therefore,  confine  himself  to  any  particular  strength  or 
temperature;  but  he  prefers  the  strength,  heat,  and  process  above  described, 

He  claims  as  his  invention,  the  subjecting  of  cotton,  linen,  and  other  vegetable 
fibrous  material,  either  in  the  fibre  or  &n^  stage  of  its  manufacture,  either  alone,  or 
mixed  with  silk,  woollen,  or  other  animal  fibrous  material,  to  the  action  of  caustic  soda 
or  caustic  potash,  dilute  sulphuric  acid,  or  solution  of  chloride  of  zinc,  of  a  tempera- 
ture and  strength  sufiicient  to  produce  the  new  effects,  and  gives  to  them  the  new  pro- 
perties above  described,  either  by  padding,  printing,  or  steeping,  immersion,  or  any 
other  mode  of  application. — Neuitoth  Journal,  xxxviii.,  p.  456. 

For  washing  textile  fabrics,  Messrs.  M'Alpin,  of  Hammersmith,  have  combined  a 
rotating  (centrifugal)  wash  vessel  with  vertical  beaters ;  a  very  effective  contrivance 
which  may  be  seen  at  work  at  any  time. 

Textile  Manufactures. — Commencing  at  the  extreme  west  of  the  Great  Exhibition  we 
observe  the  extensive  series  contributed  by  Messrs.  Hibbert,  Platt^  &  Co.,  of  Oldham, 
in  illustration  of  the  various  operations  in  preparing  and  spinning  cotton.  The  first 
operation  is  that  of  opening  the  entangled  locks,  and  of  partially  freeing  the  fibres  from 
extraneous  substances.  Instead  of  the  "  willy"  commonly  employed  for  this  purpose, 
Messrs.  Hibbert  and  Piatt  exhibit  a  novel  apparatus  of  American  origin.  The  principle 
of  action  in  this  machine  is,  that  it  draws  the  cotton  between  spiked  and  fluted  rollers, 
so  as  to  loosen  the  matted  fibres  by  drawing  action,  instead  of  by  a  rapidly  revolving 
beater ;  the  portions  of  seed  and  other  impurities  being  separated  by  the  rotation  of  other 
fluted  rollers,  which  revolve  against  the  fibres  as  they  are  held  by  the  spikes,  and  ihua 
effect  the  required  cleaning.  The  cotton,  as  it  comes  from  the  bale,  is  spread  upon  an 
endless  travelling  apron,  which  carries  it  forwards  and  delivers  it  into  the  machine. 

In  the  next  machine,  for  further  opening  and  cleansing  the  material,  two  arrange- 
ments  are  included,  which  are  not  generally  employed,  except  by  this  firm.  The  scutch- 
ing action  IS  accomplished  in  the  ordinary  manner,  the  impurities  falling  below  through 
an  iron  grating;  the  opened  locks,  however,  having  arrived  at  the  other  end  of  the 
machines  pass  over,  instead  of  under,  the  exhausting  apparatus,  so  that  the  dust  re- 
moved therefrom  by  the  draft  is  not  compelled  to  pass  through  the  sheet  of  cotton. 
There  IS  also  a  peculiar  arrangement  of  rollers,  between  and  partly  around  which  the 
web  of  cotton  is  conducted  previously  to  being  wound  into  a  lap ;  the  design  being  to 
effect  a  more  perfect  calendering  or  consolidating  of  the  fibres. 

Six  carding  machines,  which  effect  the  next  process,  are  exhibited;  two  of  these 
only,  however,  are  necessary  to  complete  the  perfect  operation  they  are  designed  to 
efleclV  the  remaining  four  being  added  merely  for  the  purpose  of  supplying  a  sufll- 
cient  quantity  of  carded  cotton  to  meet  the  demand  of  the  machining  sub^quenUy 
used.  Kefernng  then  to  two  of  these:  the  first  used  is  called  a  breaker,  and  the  lap 
of  cotton  from  the  last  machine  is  placed  so  as  to  revolve  in  a  portion  of  the  frame- 
work, to  effect  an  unwinding.  According  to  the  usual  method,  the  material  would 
pass  through  a  pair  of  rollers,  which,  by  their  revolution,  bring  it  under  the  action 
of  the  machine;  here,  however,  the  "patent  feeder"  is  employed,  consisting  of  a 
roller  and  concave  surface,  between  which  the  sheet  of  cotton  passes,  and  is  from  thence 
token  by  a  roller  called  the  "  licker-in,"  covered  with  wire  cards.  From  this  roller  the 
fibres  ire  stripped  by  the  revolution  of  the  large  central  carding  cylinder,  and  again 
teased  and  straightened  by  the  action  of  other  revolving  carding  surface*  In  many 
instances  the  whole  process  is  accomplished  by  these  means.  In  the  case,  however,  of 
the  exhibited  machinery  now  under  notice,  there  are  in  addition  to  the  rollers  a  series 
Of  stationary  surfaces,  covered  with  wire  cards,  and  having  no  concave  form,  corre- 
sponding to  the  periphery  of  a  large  revolving  cylinder.  The  material  passing  between 
these  combining  surfaces,  the  one  brushing  over  the  other,  becomes  further  straightened 
and  separated,  so  as  to  be  regularly  diffused  over  the  main  carding  surface ;  it  is  then 
removed  therefrom  by  the  doffer,  and  subsequently  stripped  in  the  form  of  a  light  fleecy 
sheet  by  the  rapid  chopping  action  of  the  doffer-comb.  A  trumpet-shaped  orifice  then 
narrows  the  sheet  of  cotton  into  a  spongy  cord  which  is  delivered  by  a  set  of  revolving  rol- 


830 


TEXTILE  MANUFACTURES. 


TEXTILE  MANUFACTURES. 


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i 


I  I 


r  i 


lers  into  a  receiver  place  below.     This  in  many  instances  is  simply  ft  cylindrical  can, 
sometimes  provided  with  a  rising  and  falling  plunger,  which,  by  pressing  upon  the  top  of 
the  material,  effects  the  stowage  of  a  greater  quantity  than  could  otherwise  be  received 
into  the  can.     Messrs.  Tathan  and   Cheetham\  patent  "coiler"  is  now,  however,  fast 
guperaeding  the  old  arrangements ;  and  the  estimation  in  which  it  is  held  is  evinced  by 
the  fact  of  its  application,  instead  of  the  old  system,  to  all  the  preparing  machinery  m 
motion  at  the  Exhibition.     The  construction  of  this  apparatus,  as  adopted  by  Messrs. 
Hibbert  and  Piatt,  somewhat  differs  from  that  of  the  original  patentees,  but  the  princiole 
of  construction  is  the  same.     The  sliver  delivered  by  the  rollers  passes  through  revolv- 
ing surfaces,  which  thus  carry  it  round,  and  deposit  it  in  circles  within  a  can  placed 
below:  this  can,  however,  not  being  stationary  but  revolving  upon  a  centre,  eccentric 
to  the  centre  of  motion  of  the  delivering  surfaces,  carries  onward  the  sliver,  as  it  falls- 
and  thereby,  instead  of  allowing  it  to  form  a  cylinder  of  cotton,  disposes  it  in  a  series 
of  coils  throughout  the  area  of  the  can.     As  the  can  becomes  filled,  the  material  rise* 
against  a  plate  at  top ;  and  the  operation  still  proceeding,  effects  a  pressing-down  of  the 
sliver,  so  as  to  produce  a  condensation  of  the  coils.     A  number  of  cans  thus  tilled  ar* 
taken  to  a  machine,  which  will  be  observed  on  the  north  side  of  the  compartment  of 
cotton  machinery.     Here  a  sufficient  number  of  slivers  are  drawn  by  a  pair  of  roller* 
from  their  cans,  and  wound  side  by  side  upon  an  axle,  so  as  to  form  a  lap;  the  fibres  in 
some  measure  adhering  to  each  other,  and  thus  constituting  a  sheet  of  the  material. 
Laps,  thus  formed,  are  taken  to  the  other  range  of  carding  engines,  and  there  undergo 
another  operation  of  teasing  and  straightening ;  and  then  pass  off  through  a  conical  tube, 
so  as  to  be  narrowed,  as  before,  into  a  spongy  cord.    The  slivers  which  constitute  th6 
lap  for  feeding  this  machine,  are  from  30  to  40  in  number;  but  are  admitted  so  slowly 
as  to  be  carded  down  to  such  an  extent  that  the  sliver  removed  from  the  doffer  is  equal 
to  one  only  of  the  number  of  slivers  which  entered ;  and  thus  any  irregularitv  thai 
might  have  existed  in  a  portion  of  the  feed  is  so  much  diffused  as  to  be  nearly,  if  not 

entirely  lost  ,       , .     -       .  .         . 

We  have  before  spoken  of  the  drawing-frame;  the  next  employed  is  of  vast  importance 
to  the  cotton  manufacture.     This  machine  has  since  its  introduction  undergone  great 
improvement,  principally  by  the  application  of  a  "stop-motion,"  which  arrests  the 
action  of  the  machine  immediately  as  the  breakage  of  a  sliver  takes  place :  this  arrange- 
ment  is  applied  to  all  the  exhibited  drawing  frames.     A  number  of  the  cans  from  the 
finishing  carding  engine  are  arranged  at  the  back  of  the  machine;  the  slivers  from  these 
pass  over  a  series  of  conductors,  termed  "spoons,"  several  slivers  being  drawn  over 
together.     These  instruments  are  weighted  guide  levers,  mounted  so  as  to  be  capable 
of  turning  upon  centres;  but  during  the  proper  working  of  the  machine  are  kept  in  a 
certain  position  by  the  tension  of  the  slivers  which  are  in  process  of  being  drawn. 
Upon  the  breakage   taking  place,  therefore,  or  upon  a  can    beconriing  empty,  the 
equilibrium  will  be  destroyed,  and  a  part  projecting  from  the  under  side  of  the  spoon 
will,  on  the  spoon  falling,  intercept  the  motion  of  a  vibrating  bar,  which,  being  thus 
arrested,  effects,  by  an  arrangement  of  apparatus  designed  for  the  purpose,  the  shitting 
of  the  driving  strap  from  the  driving  to  the  loose  pulley,  and  thereby  stops  the  action 
of  the  machine.    To  this  machine  the  patent  coiler  mentioned  m  reference  to  the  card- 
ing-engine  is  also  applied,  the  drawn  slivers  being  again  deposited  in  revolving  cans. 

These  slabbing  and  roving-frames  next  come  under  notice.  Those  exhibited  by 
Messrs.  Hibbert  and  Piatt  are  three  in  number;  the  first  two  being  distinguished  by 
the  term  slubbing-frames.  and  the  other  by  that  of  the  roving-frame.  The  operation 
»nd  arrangement  of  machinery,  however,  are  substantially  the  same;  the  only  object  of 
the  processes  being  gradually  to  reduce  the  sliver,  and  impart  to  it  a  sufficient  amount 
of  solidity  suitable  for  the  action  of  the  spinning  frames.  This  class  of  machines  is  most 
fully  represented  in  the  Exhibition,  and  the  particular  point  to  which  the  stream  of 
inventive  genius  is  now  directed  is  distinctly  shown.  The  beautiful  mechanism  of  the 
glubbing  or  roving-frarae  appears,  as  far  as  its  simplicity  of  construction  and  efficiency 
of  working  are  concerned,  to  have  arrived  at  a  point  beyond  which  there  is  but  little  to 
desire.  Invention  has  therefore  of  late  been  directed  solely  to  increase  its  quantitative 
producing  power.  The  limit  to  this  had  been  the  velocity  at  which  the  revolving 
•pindles  and  their  "flyers"  could  be  driven.  In  three  out  of  the  four  exhibitors  of 
cotton  preparing  machinery  in  motion,  we  find  evidence  of  an  earnest  attention  to  this 
subject  In  the  series  now  under  review,  the  desired  end  is  sought  to  be  accomplished 
in  two  ways;  first  by  reducing  the  top  of  the  flyer  so  as  to  enable  the  bobbin  to 
traverse  higher  than  usual,  and  thus  avoid  the  necessity  of  carrying  the  flyer  legs  so  far 
downwards ;  which,  being  thus  reduced  in  length,  will  admit  of  being  driven  at  a  higher 
speed  without  increasing  the  vibration.  The  second  method  is  by  placing  the  bevel- 
pinion,  which  drives  the  bobbin,  upon  a  fixed  socket  instead  of  upon  the  spindle,  by 
which  method  the  vibration  and  the  wear  of  the  spindle  are  diminished.  These  irrw 
provements  are  said  to  enable  the  manufacturers  to  increase  the  driving  speed  of  the 


•pmdles  one  fifth  beyond  the  ordinary  velocity  attained.  To  the  slubbing-frames  of 
Messrs.  Hibbert  and  Piatt  is  attached  a  stop  motion  similar  to  that  we  have  mentioned 
as  commonly  applied  to  the  drawing-frame.  The  motion  of  the  machine  is  therefore 
arrested  immediately  upon  the  breakage  of  a  sliver.  In  our  general  description  of  the 
cotton  manufacture  we  spoke  of  the  sliver  as  proceeding  direct  from  the  leg  of  the  flyer 
to  the  bobbin.  This  plan  is  frequently  adopted,  and  particularly  in  mills  where  the 
finest  yarns  are  spun.  In  those  machines,  however,  now  under  review  the  presser 
principle  is  adopted.  On  this  plan,  the  legs  of  the  flyers  carry  an  arm  called  a  "  presser," 
-which  receives  an  inclination  to  move  inward  by  the  action  of  a  spring,  so  as  to  bear 
against  the  surface  of  the  bobbin.  The  slivers  pass  down  the  legs  of  the  flyers,  and  are 
coiled  along  their  respective  arms,  threaded  through  eyes  formed  therein,  and  from 
thence  are  conducted  to  the  bobbins.  The  action  of  the  spring-presser  is  to  consolidate 
the  roving,  and  thereby  to  increase  the  capacity  of  the  bobbin  for  holding  the  roving 
and  prevent  the  necessity  for  frequently  changing  the  bobbin.  Tliis  arrangement  \i 
distinguished  as  the  presser  bobbin  ;  and  the  other  as  the  soft  bobbin. 

The  next  in  order  of  the  machines  to  be  noticed  are  those  for  spinning,  both  principles 
of  which,  VIZ.,  the  mule  and  the  throstle,  are  exhibited  in  this  series;  the  former  also 
being  illustrated  by  two  machines,  the  one  for  the  production  of  weft,  and  the  other  for 
warp.  We  have  already  in  our  article  Cotton  Spinning  explained  the  peculiarities  of 
these  two  constructions  of  machines,  the  operation  of  the  throstle  being  continuous, 
and  having  its  spindles  mounted  in  a  stationary  frame,  and  the  spindles  of  the  mule  being 
mounted  on  a  carriage  which  alternately  approaches  to  and  recedes  from  the  delivering 
ro  ers.  The  throstle  exhibited  by  Messrs.  Hibbert  and  Piatt  presente  no  features  that 
call  for  particular  comment;   but  in  the  mules  we  notice  a  peculiar  arrangement  of 

scavenger"  is  applied.  The  object  of  this  apparatus  is  to  clear  particles  of  waste 
from  the  top  of  the  carriage,  and  the  operation  is  effected  by  means  of  a  roller  which, 
instoad  of  sweeping  the  refuse  toward  the  cops,  moves  it  away  in  an  opposite  direction. 
Ihe  construction  of  these  mules  is  on  the  principle  of  Sharp  and  Roberts'  patent- 
they  are  provided  with  an  adjustable  cam  for  "backing  off."  and  also  an  apparatui 
applied  to  the  front  roller  for  preventing  the  threads  from  becoming  snarled 

Messrs.  Pair,  Curtis,  and  Madely,  of  Manchester,  exhibited  several  preparing  and 
spinning  machines.  The  first  of  these,  the  carding-engines,  is  provided  with  a  motion 
for  traversing  the  conical  tube  which  conducts  the  sliver  from  the  doffer  cylinder  and 
thereby  causes  it  to  be  taken  up  by  the  delivering  rollers  at  varying  parts  of  their  lengths- 
this  le  the  patent  of  Messrs.  Lakin  and  Rhode.  ^     e  f  8 

In  the  drawing-frame  there  is  a  peculiar  arrangement  of  spoon  for  the  stop  motion : 
the  lower  part  is  formed  as  a  fork;  and  under  the  space  between  the  prongs  stands  out 
a  projecUon  from  the  vibrating  shaft  which,  when  arrested  in  its  motion,  causes  the 
stoppage  of  the  machine.  The  spoons  held  up  by  passing  the  sliver  fall  vertically  upon 
a  breakage  taking  place,  and  thereby  intercept  the  vibrating  projection  with  one  or 
other  of  their  prongs,  and  consequently  arrest  the  motion  of  the  machine. 

In  the  slubbing-frame  a  spring  is  applied  to  the  presser,  differing  from  those  commonly 
employed;  it  being,  in  this  instance,  formed  as  a  coiled  watch-spring.  This  arrange- 
ment IS  intended  to  effect  a  more  equal  pressure,  and  a  reduction  in  the  weight  of  the 
flyer.    In  this  machine  also  the  tension  weight,  for  lightening  the  cone-strap,  is  carried 

«Ln  [r^'  A  TT  ??  *  P.*""*^  *"*^^^^  *^  ^^^  b«*™'  i"«tead  of  allowing  it  to  rest 
npon  the  grooved  shaft;  there  is  also  an  application  of  geaiing  to  the  shortening  and 
traverse  motions.  All  of  the  improvements  are  shown  applied  to  a  roving  frame  U^n 
3'rhv'fK^  ^°'  ""^i  •"'"  "^^t^""'-  ^^"  ^^^^^^^  ''  ^^^-"^^  ^y^^^  comparatively  litile  n^sS 
Shv!  fhrh  kk-  '°^'  ^""^  T'i  ^"'l"'''^'  ^^  fi'^^«  ^^''^  the  toothed  wheels,  which 

a^d  rWfT?  ''  are  composed  of  gutta-percha:  this  is  the  patent  of  Messrs.  Tatham 
tnL?.uiti    r'  ' '  fV^'  Pff  «°^8e«»«  probable,  the  material  should  be  found 

^here  i^ri''thi;fl  *  ^K^''''''^^^  ''^  J^^!  ^'  accomplished  by  its  introduction. 
T„  nn/fT      rr  self-acting  mules^  exhibited  by  Messrs.  Pair,  Curtis,  and  Madely. 
In  one  of  these  the  apparatus  generally  adopted  for  producing  th^  changes  required  S 
jpinning.  IS  substitoteJ  by  an  arrangement  which  is  positive  fn  it^  aS?  InTtherehj 
prevents  the  common  breakages  of  bands,  and  the  general  injury  of  the  machine     T^e 

dn^h\7lfZ^'"T'f  ^T  '"^^^"S  '^^^^^^^  '^'^  other,^an^d  thus  rendered  rn^e 
durable  by  the  application  of  an  extra  scroll. 

Another  improvement  belonging  to  this  mule  relates  to  the  arrangement  for  puitinir 
f r^takeVr^  l^'  "  ^""'•'  V  '^'  «^J-5.being  to  prevent  a  coil  Ihen  the  "  bCk  n| 

^^tt^tl^fhtL  V  P^r'"'^'"^  ^  ""^.'^^"2  °^  ^^™^g«  ^f  the  yarn.  The  "squarinf 
shaft    8^  m  this  machine,  driven  b^  gearing  instead  of  bands,  as  usual.  ^  ^ 

Smtl,  «n'J  n  ^^^"^  t!  °'"^'  ^'i^'^^^  ^"^  improvement  upon  that  principle  known  as 
Smthand  Orrs.  Tlie  present  construction  dispenses  wk  the  frfcUon  or  differentij 
motion  for  winding  on  the  yarn,  and  substitutes  an  application  of  the  radial  arm^ 
arranged  so  as  to  prevent  breakages  of  the  mangle-wheel.    The  roUers  driven  inde^ 


'    I 


832 


TEXTILE  MANUFACTURES. 


TEXTILE  MANUFACTURES. 


I! 


pendently  of  the  maDgle-wheel,  necessarilj  prevent  a  strain  thereon ;  they  may  be  put 
m  motion  or  stopped  at  pleasure ;  and  as  they  derive  their  rotation  from  the  driving 
pinion,  a  more  uniform  action  is  obtained.     This  mule  also  is  driven  by  one  strap  instead 

of  two. 

The  third  mule  contains  a  new  arrangement  of  the  patented  improvements  of  this 
firm,  a  new  motion  for  winding  on  the  yarn  with  a  self-regulator  being  applied ;  the 
design  being  to  enable  a  person,  capable  of  "piecing  ends,"  to  superintend  the  machine, 
and  reduce  the  making  of  a  set  of  cops  to  as  easy  a  task  as  the  making  a  set  of  bobbins 
on  a  roving  frame. 

We  next  arrive  at  the  machinery  of  Mr.  John  Mason,  of  Rochdale:  here  we  find  a 
drawing  frame,  with  patent  coiler;  and  also  slubbing  and  roving-frames.  The  two 
last-mentioned  machines  are  fitted  with  improvements  for  obtaining  a  greater  velocity 
in  the  rotation  of  the  spindles.  This  consists  in  firmly  attaching  to  the  copping-rail, 
tubes,  over  which  the  bobbins  pass,  they  being  hollowed  out  sufiiciently  large  for  that 
purpose.  The  spindles  pass  through  the  tubes,  and  run  in  contact  with  the  internal 
periphery  thereof  at  top  and  bottom ;  by  which  arrangement,  two  bearings  are  obtained 
a  considerable  distance  apart,  affording  a  support  productive  of  great  steadiness  of  action. 
It  is  stated  that,  with  the  application  of  this  arrangement,  the  spindles  of  roving 
machines,  where  the  lift  of  the  bobbin  is  six  or  seven  inches,  may  make  from  1,200  to 
1,400  revolutions  per  minute.  This  improvement  is  exhibited  as  applied  to  a  frame 
where  pressers  are  used ;  and  also  to  one  arranged  for  the  production  of  soft  bobbins. 

Another  improvement  in  these  machines  is  the  application  of  a  plate,  situated  before 
the  delivering  rollers,  and  through  which  the  rovings  pass  on  their  way  to  the  bobbins ; 
this  is  for  the  purpose  of  preventing  an  entanglement  when  an  end  becomes  broken,  an 
inconvenience  which  frequently  occurs  in  the  ordinarv  arrangements.  The  perforated 
plates  effect  this  by  forming  a  shield,  which  keeps  the  broken  roving  from  falling  down 
ward  to  the  other  threads.  To  these  machines  an  apparatus  is  also  applied  for 
disengaging  the  parts  which  drive  the  bobbins  or  spindles  from  the  other  parts  of  the 
machines:  so  that  the  whole  series  may  be  turned  at  once  by  hand  when  the  bobbins  are 
full,  for  the  purpose  of  unwinding  a  suflScient  length  of  each  thread,  for  forming  an  at- 
tachment to  the  fresh  bobbins. 

In  front  of  Mr.  Mason's  machinery  will  be  found  that  of  Messrs.  Higgins  and  Sons,  of 
Salford.  The  roving  frame  of  this  firm  exhibits  another  instance  of  the  attention  paid  to 
a  gain  of  speed  in  the  revolution  of  the  spindles.  According  to  the  usual  practice  the 
spindles  are  formed  of  the  same  diameter  throughout  the  upper  part  of  their  length ;  but 
in  the  roving-frame  now  spoken  of,  the  spindles  are  formed  of  varying  diameters,  de- 
creasing toward  the  top,  which  configuration  admits  of  their  being  driven  at  a  greatly 
increased  velocity,  without  an  extended  vibration :  the  flyers  also  are  so  attached  that 
the  bobbin  may  traverse  to  a  higher  point  that  usual ;  and  thus  the  legs  are  decreased 
in  length,  and  consequently  reduced  in  weight,  possessing  at  the  same  time  a  stiflFness 
which  will  bear  an  increased  revolution.  The  conical  pulley  is  mounted  upon  a  frame 
which  swings  upon  centres,  so  that  at  whatever  diameter  the  strap  may  be  situated  it 
will  always  be  distended. 

In  the  compartment  containing  the  machinery  we  have  described  are  some  cases  of 
spindles  and  flyers  of  various  constructions  now  in  use :  amongst  these  is  one  which,  as 
it  bears  upon  the  subject  of  increased  speed,  we  will  particularize ;  this  is  the  invention 
of  Mr.  William  Maclardy,  of  Manchester.  The  object  sought  is  Jiere  attained  by  causing 
the  spindle  to  run  in  a  top  bearing,  so  as  to  eflfect  a  greater  steadiness  of  action ;  and  in 
order  to  provide  for  the  removal  of  the  fill  bobbins,  the  spindle  is  formed  in  two  por- 
tions which  are  temporarily  connected  together ;  their  separation  is  accomplished  by 
lifting  the  upper  part  of  its  top  bearing;  when,  the  lower  end  being  turned  in  its  bottom 
bearing,  so  as  to  occupy  a  position  out  of  a  right  line,  the  filled  bobbing  mav  be  slipped 
oflF.    We  are  informed  that  these  spindles  are  running  at  a  considerably  increased 

Messra  Sharp,  Brothers,  of  Manchester,  exhibited  a  throstle  spinning  frame  on  the 
•*  ring  and  traveller  "  principle.  This  machine  is  of  American  origin,  and,  although  used 
to  a  considerable  extent  in  that  country,  has  made  but  little  progress  here.  The  thread, 
instead  of  passing  on  to  the  bobbin  through  a  flyer,  as  in  other  throstles,  is  conducted 
through  a  fine  metallic  loop,  mounted  so  as  to  revolve  upon  arms  which  project  fropa 
the  copping  rail :  this  loop  is  dragged  round  by  the  traction  of  the  thread.  The  bobbin 
does  not  in  this  case  rise  and  fall,  to  distribute  the  yarn  upon  its  surface,  but  the  same 
eflfect  is  produced  by  the  upward  and  downward  motion  of  the  ring.  This  machine 
exhibits  an  arrangement  of  friction  surfaces  in  place  of  the  ordinary  driving  toothed 

v^heels. 

In  the  French  department  was  exhibited  a  machine  calhed  the  "  Epurator,"  the  design 
of  which  is  to  supersede  the  use  of  the  ordinary  scutching  machine,  and  eflTect  by  one 
operatioa  the  cleaning  and  carding  of  the  material    When  practice  has  confirmed  the 


833 


use  of  two  distinct  processes,  it  rarely  occurs  that  the  final  object  can  be  achieved  by  one : 
all  endeavors,  however,  to  arrive  at  a  simplification  of  operations  should  be  viewed 
with  consideration.  The  material  to  be  operated  upon  by  this  machine  is  formed  into 
laps,  by  a  spreading  apparatus,  a  number  of  which  laps  (five  in  the  exhibited  machine) 
are  placed  so  as  to  be  simultaneously  fed  by  revolving  fluted  rollers  to  the  cleaning  and 
carding  cylinder.  This  cylinder  is  4  feet  in  diameter,  and  revolves  at  the  rate  of  from 
250  to  270  revolutions  per  minute,  its  periphery  is  provided  with  a  series  of  strips  of 
wire  cards,  with  strong  teeth,  between  which  strips  are  placed  flexible  metallic  brushee^ 
the  extremities  of  which  project  slightly  beyond  the  surface  of  the  cards.  The  grooved 
feeding  rollers  revolve  slowly,  and  therefore  present  the  cotton  gradually  to  the  action 
of  the  revolving  cards  and  brushes;  the  eflfect  of  which  is  said  to  be  the  combined 
operation  of  scutching  and  carding,  the  impurities  being  separated  by  centrifugal  force^ 
and  the  loosened  fibres  laid  side  by  side  without  being  broken  by  the  action  of  revolving 
beaters.  Beneath  each  pair  of  feeding  rollers  there  are  gratings,  through  which  the 
separated  extraneous  matters  fall.  There  are  three  diflferent  cylinders  to  this  machine, 
for  the  more  perfect  removal  of  the  cotton ;  each  one  of  which  is  provided  with  the 
usual  doflSng  combs  for  the  removal  of  the  slivers,  which  are  then  guided  so  as  to  unite 
into  one.  The  exhibitor  states  that  this  machine  will  produce  from  220  to  260  Ibi  of 
prepared  cotton  in  12  hours, — one  workman  superintending  two  or  three  machines* 
and  that  if  coarser  numbers  are  to  be  spun,  a  subsequent  carding  is  unnecessary  the 
cotton  being  taken  from  the  epurator  direct  to  the  drawing  frame. 

Near  the  machine  last  described  will  be  seen  a  roving-frame  of  French  manufacture^ 
in  which  the  arrangement  of  wheels  for  driving  the  spindles  and  bobbins  is  diflferent  from 
that  commonly  employed  in  England.  Instead  of  the  two  shafts,  carrying  their  series 
of  bevel-wheels,  one  only  is  employed,  which  drives  a  pinion  mounted  upon  a  loose  col- 
lar. On  the  upper  end  of  this,  there  is  a  spur-wheel,  which  takes  into  the  teeth  of  two 
spur-pinions,  each  of  which  is  used  for  driving  a  bobbin  or  spindle,  as  the  case  may  be. 
In  the  Belgian  department  a  willow  is  exhibited  by  the  Soci6te  du  Phoenix,  of  Ghent 
The  peculiarity  of  this  machine  consists  in  the  employment  of  a  revolving  shaft,  provided 
with  a  series  of  projecting  arms,  arranged  in  a  spiral  form.  This  shaft  is  enclosed  within 
a  casing,  the  internal  surface  of  which  is  provided  with  an  iron  grating.  The  cotton  is 
fed  in  through  an  aperture  at  one  end  of  the  casing,  and  beaten  by  the  spirally-arranged 
revolving  arms,  which,  at  the  same  time,  carry  it  forward  to  be  delivered  out  at  the 
other  end,  the  separated  impurities  falling  through  the  surrounding  grating. 

From  Belgium  we  have  also  a  roving  frame  possessing  a  feature  not  entirely  new  to 
us,  but  as  yet  unemployed.  This  consists  in  the  employment  of  toothed  segments,  of 
decreasing  diameter,  which  constitute  conical  wheels,  and  are  intended  to  dwplace  the 
conical  pulleys  now  ordinarily  used ;  the  segments  are  locked,  one  after  the  other,  to 
their  shafts,  so  as  to  eflfect  the  required  rotation  at  the  necessary  variable  speed ;  this 
invention  is  the  subject  of  a  patent  in  England  granted  to  Messrs.  Fairbairn  and 
Hetherington. 

The  Exhibition  does  not  illustrate  fully  the  manufacture  of  woollen  fabrics ;  a  system 
of  producing  woollen  yarns  is,  however  exhibited  by  Mr.  J.  Mason,  of  Rochdale,  and 
claims  particular  attention.  The  machinery  to  which  we  refer  has  been  for  some  years 
in  general  operation  in  France  and  Belgium ;  but  the  slowness  with  which  an  entu-e 
change  of  system  is  received  in  England,  has  prevented  it  from  becoming  so  extensively 
employed  as  its  merit  seems  to  demand.  In  order  that  this  machinery  may  be  properly 
understood,  we  must^  in  the  first  place,  briefly  describe  the  usual  processes  employed  for 
the  production  of  woollen  yarns,  premising  that  our  present  notice  refers  to  that  branch 
of  the  manufacture  relating  to  the  class  of  goods  technically  distinguished  as  "woollens'* 
in  distinction  to  *'  worsteds,"  comprising  broad-cloth,  flannels,  Ac,  and  made  from 
shorter  descriptions  of  wools. 

The  material  is  first  cleaned  by  a  machine  similar  to  the  willow  of  the  cotton  manu- 
facture, and  18  then  subjected  to  the  process  of  carding,  called,  in  this  instance,  "scrib- 
bhng.  After  this,  another  card  operation  follows,  the  wool  being  doflfed  therefrom  not  in 
a  continuous  film,  as  described  in  reference  to  cotten,  but  in  short  spongy  cards,'  equal 
^\^-?,°?w  ^  ^^ly^^^^  of  ^^e  carding  engine;  these  "cardings"  are  then  taken  to  the 
"billy  (a  machine  operating  upon  the  principle  of  the  muleX  where  they  are  joined 
one  to  another,  generally  by  hand,  so  as  to  form  continuous  lengths,  and  twisted  pre- 
viously to  being  wound  into  cops,  which  are  to  be  transferred  to  the  spinning  machine. 
According  to  the  system  exhibited  by  Mr.  Mason,  the  wool  as  it  is  taken  by  the 
ordinary  action  of  the  doflfer  comb  from  the  first  carding  machine,  is  gathered  into  a 
narrow  band,  and  after  passing  through  a  revolving  tube,  which  imparts  a  certain 
amount  of  false  twist  is  wound  upon  a  roller,  so  as  to  constitute  a  lap,  about  16  inchea 
in  diameter,  and  4  or  6  inches  in  breadth.  When  the  required  quantity  is  wound  on, 
an  arrangement  of  apparatus,  by  ringing  a  bell,  gives  notice  to  the  attendant;  imme 
diately  after  which,  the  winding  machinery,  by  a  self-acting  motion,  disengages  the  lap* 
Vol.  IL — 53 


834 


THEINE. 


THERMOMETER. 


835 


|i!l 


BO  tliat  a  determinate  quantity  of  material  is  always  wound  upon  the  roller.  Several  of 
these  narrow  laps  are  placed,  side  by  side,  upon  a  framework  attached  to  a  second 
carding  machine ;  and  tneir  rollers  are  mounted  so  as  to  be  capable  of  revolving,  in 
order  to  unwind  the  carded  wool,  which  unwinding  is  effected  through  the  agency  of 
surface  rollers,  placed  in  contact  with  the  lapped  material.  The  slivers,  constituting 
the  laps,  are  applied  in  such  a  number,  that  their  aggregate  width  shall  be  equal  to  that 
of  the  required  feed ;  and  they  are  conducted  through  guides,  so  as  to  bring  their 
edges  together,  and  thus  form  a  continuous  sheet  as  they  are  fed  into  the  second  card* 
ingengine. 

The  wool  having  been  carded  as  usual,  is  removed  by  the  agency  of  two  doffer 
cylinders,  each  of  which  has  alternate  rings  of  wire  cards  and  blank  places;  the  rings 
of  cards  on  the  one  doffer  being  opposite  to  the  spaces  on  the  other,  and  vice  versd.  By 
this  arrangement,  each  doffer  removes  a  series  of  narrow  strips  of  wool,  which,  being 
conducted  therefrom  by  stripper  rollers,  form  endless  spongy  cords,  instead  of  the  short 
cardings  before  referred  to.  These  endless  cords  are  then  conducted  between  travel- 
ling straps,  placed  at  right  angles  to  the  line  of  progress  of  the  cords,  which  straps  by 
their  rubbing  action,  condense  the  material  previously  to  its  being  wound  upon  rol- 
lers^ and  sufficiently  to  admit  of  its  being  taken  direct  to  the  spinning  machine. 

It  will  be  understood  frofti  the  foregoing  statement,  that  this  system  effects  a  great 
economy  of  labor ;  the  feeding  being  self-acting,  and  the  piecing  and  slubbing  being 
dispensed  with.  This  simplification,  however,  is  not  the  only  advantage ;  the  selt 
feeder  supplies  the  machine  in  a  much  more  regular  manner  than  can  be  attained  by 
hand ;  and  the  "  cardings"  are,  consequently,  more  even ;  the  manufactured  threads  are 
also  more  "nappy,"  which  increases  the  felting  quality  in  milling,  and  affords  a  rich- 
ness of  appearance  in  the  woven  cloth  not  attained  in  the  usual  course  of  manufacture. 

In  manufacturing  warps  on  this  system,  it  is  merely  necessary  to  double  the  slivers  of 
wool  upon  an  intermediate  engine,  and  draw  the  slubbing  more  in  the  "  condenser"  and 
mule,  to  obtain  that  straightness  of  fibre  which  gives  strength  to  the  thread.  If  the 
first  process  of  obtaining  narrow  laps  be  repeated,  so  that  two  carding  engines  are  fed 
by  a  number  of  these,  a  doubling,  not  attainable  under  the  old  system,  may  be  effected, 
which  will  of  course  add  to  the  regularity  of  the  yarn.  That  this  system  is  not 
universally  adopted  may  be  attributed,  in  gi-eat  measure,  to  the  failures  which  have 
taken  place  in  other  attempts  to  obtain  endless  cardings.  Mr.  Mason's  machinery  is 
now,  however,  employed  by  some  of  the  most  eminent  firms  of  the  north  and  west  of 
England ;  and  therefore  may  be  looked  upon  as  making  its  way  towards  that  position 
which  its  merits  entitle  it  to  attain. 

The  French  department  contains  an  example  of  an  endless  carding  machine  con^ 
tributed  by  Messrs.  Merciere  &  Co.,  of  Louviers ;  the  chief  distinction  from  that  we 
have  above  described  being  the  employment  of  series  of  revolving  tubes  for  consolida- 
ting the  cardings,  instead  of  the  travelling  straps  of  Mr.  Muson.  In  the  "first"  carding 
engine  exhibited  with  this  endless  carding  engine,  the  feed  apron  is  divided  into  two 
parts,  and  the  sliver  is  removed  from  the  doffer  in  the  same  number  of  distinct  weba, 
which  pass  through  separate  conical  apertures,  but  are  finally  united  upon  the  same 
lap  roller.  The  object  of  this  is  to  work  the  machine  with  different  colors  of  wool, 
wnich,  becoming  mixed  at  the  next  operation,  afford  a  parti-colored  carding.  In  con 
nection  with  these  machines  is  also  a  hand  woollen  mule ;  it  does  not,  however,  ajv 
pear  to  possess  any  novelty  which  demands  notice. 

THEINE,  the  principle  of  tea.  It  may  be  conveniently  prepared  by  sublimation  in 
the  apparatus  of  Mohr,  for  preparing  benzoic  acid,  which  consists  of  a  shallow  iron 
pan,  having  its  mouth  covered  with  tissue  paper  secured  tight  round  the  edges;  and 
the  whole  then  surmounted  with  a  conical  paper  cap. 

A  decoction  of  the  tea  is  precipitated  by  acetate  of  lead,  the  liquor  filtered  hot  and 
evaporated  to  dryness.    The  dry  extract  is  sublimed  as  above  described. 

The  following  proportions  of  theine  were  obtained  from  different  kinds  of  tea  :— 


From  green  hyson 
"  black  Congo 
"  "  Assam 
twankay  (green) 


«( 


1*05  per  cent 

1-02 

1-87 

0-98 


Theine  was  obtained  from  coffee  by  the  same  process  slightly  altered.  The  active 
properties  of  tea  are  due  to  this  principle. 

The  decoction  of  Paraguay  tea  was  precipitated  first  by  acetate  of  lead,  and  then  the 
filtered  liquor  by  subacetate  of  lead ;  and  the  liquid  drawn  off  and  evaporated  to  dry- 
ness. When  the  extract  was  submitted  to  distillation,  it  gave  long  flat  crystals  exactly 
resembing  theine.  The  sublimate  also  resembled  theine  in  its  odor  and  relations  to 
water,  alcohol,  and  ether.    It  also  answered  to  the  following  new  test  of  theine. 


Found. 

Calculated 

-    49-06 

49-79 

-      5145 

6-08 

Theme  18  boiled  for  a  few  minutes  with  twice  ita  weight  of  fuming  nitric  acid,  by 
which  a  bright  yellow  solution  is  obtained.  This  liquid,  gently  evaporated  to  drynesfl^ 
leaves  a  deep  yellow  mass.  A  drop  of  ammonia  is  let  fall  upon  this,  and  a  gentle  heat 
applied,  when  a  splendid  purple  color  is  immediately  produced,  similar  to  that  from 

The  carbon  and  hydrogen  in  the  theine  of  Paraguay  tea  were  also  determined:— 

Carbon     .  .  .  • 

Hydrogen  -  -  . 

From  want  of  material  the  nitrogen  was  not  determined.  There  is  no  doubt  that 
Paraguay  tea  contains  theine,  although  the  proportion  is  small. 

The  leaves  of  the  Camellia  Japonica  and  of  the  holly  were  examined  for  theine,  and 
found  to  contain  none.     See  Tea. 

THENARD'S  BLUE,  or  COBALT  BLUE,  is  prepared  by  digesting  the  oxide  of  co- 
bait  used  m  the  potteries,  with  nitric  acid,  evaporating  the  nitrate  almost  to  drynessL 
dilutmg  It  with  water,  and  filtering,  to  separate  some  arseniate  of  iron,  which  usually 
precipitates.  The  clear  liquor  is  to  be  poured  into  a  solution  of  phosphate  of  soda, 
whence  an  insoluble  phosphate  of  cobalt  falls.  This  being  well  washed  is  to  be  in^ 
timately  mixed  in  its  soft  state  with  eight  times  its  weight  of  well-washed  gelatinous 
•alumina,  which  has  been  obtained  by  pouring  a  solution  of  alum  into  water  of  ammonia 
in  excess.  The  uniformly  colored  paste  is  to  be  spread  upon  plates,  dried  in  a  stove, 
then  bruised  m  a  dry  mortar,  enclosed  in  a  crucible,  and  subjected  to  a  cherry-red  heat 
for  half  an  hour.  On  taking  out  the  crucible,  and  letting  it  cool,  the  fine  blue  pigment 
IS  to  be  removed  into  a  bottle,  which  is  to  be  stoppered  till  used. 

The  arseniate  of  Cobalt  may  be  substituted,  in  the  above  process,  for  the  phosphate  but 
It  must  be  mixed  with  sixteen  times  its  weight  of  the  washed  gelatinous  alumina  'The 
arseniate  is  procured  by  pouring  the  dilute  nitrate  of  cobalt  into  a  solution  of  arseniate 
of  pota^a.  If  nitrate  of  cobalt  be  mixed  with  alumina,  and  the  mixture  be  treated  as 
above  described,  a  blue  pigment  will  also  be  obtained,  but  paler  than  the  preceding: 

SSSf^ioXl*    ^^^^  consists  essentially  of  alumina  stained  with  oxide  of  cobalt 

IMJi-OBROMINE,  IS  a  chemical  principle  found  in  cocoa  beans,  and  identical  with 
catteine  and  theine  as  obtained  from  tea  and  coffee.  It  is  extracted  by  boiling  with 
water,  filtering,  precipitating  with  acetate  of  lead,  filtering  the  precipitate  after  wash- 
ing  11,  then  decomposing  it  by  sulphuretted  hydrogen;  or  boiling  it  with  alcohol,  from 
wnicb,  on  cooling,  the  theobromine  separates  in  a  crystalline  powder.  It  is  purified  by 
re-crystalhzation.     It  is  little  soluble  in  water  or  alcohol 

THERMOMETER,  signifies  the  measure  of  heat  Its  description  belongs  to  a  treatise 
on  chemical  physics.  ^ 

Philosophers  have  been  always  much  troubled  by  the  failures  of  the  maximum  self- 
registering  thermometers,  especially  those  exposed  to  the  sun;  the  part  of  the  tube  in 
which  the  index  ought  to  slide  becomes  foul,  apparently  lined  with  a  coat  of  metal,  and 
the  mdex  IS  immovable.  A  construction  invented  by  Messrs.  Negretti  &  Zambra  ao- 
pears  hkely  to  evade  this  difficulty.  The  mercury  in  its  expansion  is  forced  past  an  ot 
struction  in  the  tube,  and  does  not  return  past  it  in  its  contraction.  No  index  is  re- 
quired  in  this  construction.  "  The  specimens  of  this  instrument  which  we  have  tried 
answer  well,"  says  the  Astronomer  Royal. 

In  the  Quarterly  Report  of  the  Registrar  General,  there  is  the  following  annotation  :^ 

U  fW  !.f  V    °^/"«i''"'"«'?<^  »^«Pted  during  the  past  quarter  for  maximum  temperature 
IS  that  of  Negretti  cfe  Zambra,  which  is  found  to  act  admirably  "  f      ^uic 

wffjnTiffTK'*''  ^«.*«^?"«^«=    ai,'"^'!  piece  of  glass  is  inserted  near  the  bulb  and 
^la  fi-      •"^''  7^''^  \*  "'^'^^  fills  ;-on  an  increase  of  temperature,  the  mercuir 

S'usted  indicates  the  maximum  temperature.     After  reading,  it  is  easily 

FfJZfel^irt^  ""'y^^'^retti  &  ZaMs  Self-Registering  Maximnm  TIierm<ymeteT.-^ 
For  determination  of  the  maximum  temperature  of  the  air.-Suspend  the  thermometer 
by  means  of  the  two  brass  plates  attached  for  that  purpose,  in  such  manner  that  the 
bulb  18  a  htUe  lower  than  the  other  part  of  the  instrument,  and  so  placed  that  it  is  in 
the  shade,  with  the  air  passing  freely  to  it  from  all  sides:  then  on  an  increase  of  heat 
the  mercury  will  pass  up  the  tube  as  in  an  ordinary  thermometer,  and  continue  doine 
80  as  long  as  the  heat  increases.  ° 

On  a  decrease  of  heat,  the  contraction  of  mercury  will  take  place  below  the  bend  in 
the  tube,  leaving  the  whole  column  of  mercury  in  the  tube,  thus  registering  the  highest 
tem^>erature,  and  showing  such  till  the  instrument  is  disturbed.     °  °  & 

To  prepare  the  instrument  for  future  observation,  it  is  simply  necessary  to  remoye 


836 


THERMOMETER. 


that  end  from  its  hook  which  is  the  farthest  from  the  bulb ;  to  raise  it^  till  the  instru- 
ment is  nearly  perpendicular;  and  then  to  slightly  agitate  it  while  the  brass  plate  the 
nearest  to  the  bulb  is  still  suspended  from  its  hook.  The  mercury  will  descend  in  the 
tube,  and  indicate  the  temperature  of  the  air  at  that  time,  and  when  again  suspended 
from  its  hook,  is  prepared  for  future  observation. 

For  determination  of  the  solar  radiation,— The  instrument  for  this  purpose  must 
have  a  black  bulb ;  it  should  be  placed  nearly  horizontal,  with  its  bulb  in  the  full  rays 
of  the  sun,  and  if  possible,  so  that  lateral  wind  should  not  strike  the  bulb.  The  direc- 
tions for  use  are  identical  with  that  for  the  determination  of  the  temperature  of  the 
air. 

THERMOMETER,  SELF-REGISTERING,  by  Mr.  Brooke.  The  Exhibition  con- 
tained a  wet  and  dry  bulb  thermometer,  and  apparatus  for  registering  the  tempera- 
ture they  indicate.  The  registering  apparatus  consists  of  a  pair  of  vertical  concentric 
cylindei-8,  supported  on  a  table.  The  bulbs  of  the  thermometers  are  underneath  the 
table,  through  which  the  stems  pass  vertically,  and  are  placed  between  the  opposite 
sides  of  the  cylinders  and  two  lights.  A  narrow  vertical  hne  of  light  brought  to  a  focus 
by  a  cylindrical  lens  falls  on  the  stem  of  the  thermometer,  and  passing  through  the 
empty  portion  of  the  bore  affects  the  paper.  The  boundary  between  the  darkened 
and  undarkened  portion  indicates  the  position  of  the  mercury  in  the  stem  of  the  ther- 
mometer. Fine  wires  are  placed  across  the  slit  in  the  frame,  through  which  light 
falls  on  the  stem.  They  intercept  narrow  portions  of  the  light,  and  thus  the  scale 
of  the  thermometer  is  continuously  impressed  on  the  register,  as  well  as  the  tempera- 
ture, a,  6,  Jig.  144*7,  are  campliine  lamps;  1447 
c,  d^  cylindrical  lenses,  by  which  a  bright 
focal  line  of  light  is  obtained ;  e,  the  psyehro- 
meter,  or  wet  bulb  thermometer ;  /,  the  dry 
bulb  thermometer;  g,  two  concentric  cylin- 
ders, between  which  the  photographic  paper 
is  placed ;  A,  the  register,  as  it  appears  after 
the  impression  is  developed;  i,  one  of  the 
rollers  of  a  turn-table,  on  which  the  cylinders 
rest;  j,  the  frame  which  contains  the  time- 
piece; k,  a  bent  pin,  or  carrier,  attached  to 
the  axis  of  the  cylinders;  this  is  carried  round 
by  a  fork  at  the  end  of  the  hour  hand  of  the 
time-piece.  As  this  apparatus  is  necessarily 
placed  in  the  open  air,  when  in  actual  opera- 
tion it  is  provided  with,  1,  an  inner  cylin- 
drical zinc  case,  with  sliding  doors,  to  protect 
the  sensitive  paper  from  light,  when  the  cy-  ^ 
linder  is  removed  from,  and  brought  back  to 
the  photographic  room;  2,  an  outer  wind 
and  water-tight  zinc  case,  with  water-tight 
doors  for  removing  and  replacing  the  cylin- 
ders, and  for  trimming  the  lamps,  if  lamps 
are  used. 

The  skilful  application  of  photography  by 
Mr.  Brooke  to  register  natural  phenomena, 
with  no  more  labor  than  that  of  supplying  the  cylinder  punctually  with  prepared  pa- 
per, is  one  of  the  most  useful  and  beautiful  uses  to  which  photography  has  as  yet  been 
applied.  Tlie  paper  is  prepared  so  as  to  render  it  extremely  sensitive  to  light,  being 
first  washed  with  a  solution  of  isinglass,  bromide  of  potassium  and  iodide  of  potassium, 
in  the  proportion  of  1,  3,  and  2,  respectively ;  and  when  required  for  use,  it  is  washed 
with  an  aqueous  solution  of  nitrate  of  silver,  which  causes  the  paper  to  be  sufficiently  sen- 
sitive to  the  action  of  light,  so  that  if  a  beam  of  light  be  allowed  to  fall  upon  it^  an  im- 
pression is  made  upon  that  part  where  the  light  falls,  which  becomes  visible  on  being 
washed  with  a  solution  of  gallic  acid,  with  a  small  admixture  of  acetic  acid.  A  light  is 
placed  near  a  small  aperture,  through  which  rays  pass  and  fall  upon  a  concave  mirror 
carried  by  a  part  of  the  suspension  apparatus  of  the  magnet,  and  this  reflection  falls 
upon  a  piano-cylindrical  lens  of  glass  placed  at  the  distance  of  its  focal  length  from  the 
paper  on  the  cylinder.  As  the  magnet  is  ever  varying  and  making  small  excursions  on 
one  or  other  side  of  its  mean  position,  the  point  of  light  traces  a  corresponding  zigzag 
on  the  paper.  The  thermometer  apparatus  has  no  mirror  and  no  reflector,  the  mercury 
in  the  tubes  themselves,  intercepting  the  pencils  of  light ;  and  thus  this  apparatus, 
throughout  the  day  and  nighty  is  constantly  recording  the  slightest  change  of  position 
of  the  magnets  and  the  smallest  changes  of  temperature. 

The  object  of  this  self-registering  magnetometer  above  described  is  to  determine  the 


THERMOMETER. 


837 


direction  and  intensity  of  the  earth's  magnetism.  Its  direction  is  generally  found  by 
suspending  a  piece  of  steel  previously  magnetized,  or  in  other  words  a  magnet,  by 
parallel  threads  of  untwisted  silk,  and  the  bar  settles  in  that  position  in  which  mag- 
netism causes  it  to  rest,  and  which  is  called  the  magnetic  meridian.  The  angle  between 
the  astronomical  meridian  and  the  magnetic  meridian  gives  the  magnetic  declination 
which  is  the  subject  of  research  with  the  declination  magnetometer;  at  present^  this 
value  m  London  is  about  22^°  west  of  the  astronomical  meridian. 

Having  determined  the  declination,  the  vertical  plane  is  determined  in  which  the 
force  of  magnetism  is  exerted. 

The  angle  which  the  magnet  makes  when  freely  suspended  on  this  plane  from  the 
horizon  is  termed  the  dip.  At  present  the  dip  at  London  is  about  68°  40'.  The  force 
of  magnetism  exerted  in  this  inclined  direction  can  be  resolved  into  two  forces,  the  one 
acting  in  a  horizontal  direction,  the  other  in  a  vertical  direction,  so  that  conjointly  they 
shall  produce  exactljp^  the  same  force  as  the  single  force.  The  biplar,  or  horizontal 
force  magnetometer  is  intended  for  measuring  the  variations  of  the  horizontal  com- 

Eonent  of  the  variations  of  the  force  of  magnetism.  It  consists  of  a  magnet  suspended 
y  two  halves  of  a  skein  of  untwisted  silk,  kept  at  a  certain  distance  apart  If  an  un- 
magnetized  bar  were  thus  suspended,  it  would  remain  at  rest  only  in  that  position  ir. 
which  the  two  parts  of  the  suspension  skein  were  without  twist,  and  if  it  were  turned 
out  of  this  position,  it  would  endeavor  to  resume  its  former  position  with  a  force  pro- 
portionate to  its  weighty  and  the  angle  through  which  it  had  been  turned.  This  prin- 
ciple is  made  the  means  of  measuring  the  force  of  magnetism.  A  freely  suspended 
magnet  alwaj^s  endeavors  to  rest  in  the  magnetic  meridian. 

The  variations  in  the  vertical  component  of  the  magnetic  dip  are  the  subjects  of  in- 
vestigation with  the  vertical  force  magnet,  which  is  a  magnet  placed  nearly  at  right 
angles  to  the  magnetic  meridian.  It  is  kept  horizontal,  or  nearly  so,  by  weights  balanced 
with  extreme  accuracy,  and  made  to  vibrate  like  a  balance;  and  from  its  diflferent  in- 
clination the  variation  of  the  vertical  force  of  magnetism  is  determined. 

Thermoynetrical  Table,  by  Alfred  S.  Taylor,  Esq.— The  accompanying  therm ometrical 
table  of  Mr.  A.  Taylor,  has  been  copied  from  a  thermometer  in  his  possession,  graduated 
on  the  scales  of  Fahrenheit  and  Celsius.  It  has  been  designed  to  obviate  the  necessity 
f6r  those  perplexing  calculations,  so  often  rendered  necessary  by  the  use  of  different 
methods  of  graduation  in  England  and  on  the  Continent  In  most  chemical  works,  we 
find,  besides  the  rules  given  for  the  conversion  of  the  degrees  of  one  scale  into  those  of 
another,  comparative  tables,  which,  however,  convey  no  information  beyond  the  bare 
fact  of  the  correspondence  of  certain  degrees.  In  this  table,  the  attempt  has  been  made 
to  make  it  convey  information  on  numerous  interesting  points,  connected  with  temper- 
ature in  relation  to  climatology,  physical  geography,  chemistry,  and  physiology. 

There  is  another  advantage  which  a  table  of  this  kind  must  possess  over  those  hitherto 
published  m  works  on  chemistry.  In  the  latter,  the  degrees  on  one  scale  only  run  in 
arithmetical  progression,  while  the  corresponding  degrees  on  the  other  scale,  are  neces- 
sarily given  m  fractional  or  decimal  parts,  and  at  unequal  intervals.  Thus,  in  some  of 
the  best  works  on  chemistry,  a  comparative  table  is  printed,  which  is  only  fitted  for  the 
conversion  of  the  Centigrade  into  Fahrenheit  degrees,  so  that  a  person  wishing  to  convert 
the  Fahrenheit  into  Centigrade  degrees,  would  have  to  revert  to  one  of  the  old  formula 
of  conversion.  This  process  must  also  be  adopted  whenever  the  Centigrade  degrees  are 
given  in  decimal  parts,  for  all  the  tables  yet  published  in  English  works,  wrongly 
assume  that  the  Centigrade  degrees  are  always  given  in  whole  numbera  The  present 
table  renders  such  calculations  unnecessary,  since  the  value  of  any  degree,  or  of  any 
part  of  a  degree  on  one  scale,  i«  immediately  found  on  the  other  by  looking  at  the 
degree  m  a  paralle  line  with  it  The  main  divisions  will,  I  believe,  be  found  perfecUy 
occurate:-in  single  degrees  a  little  inequality  may  be  occasionally  detected;  but  I 
have  not  found  the  error  to  be  such  as  to  affect  the  calculated  temperature. 

Although  the  Fahrenheit  and  Centigrade  scales  are  the  two  which  are  chiefly  used  in 
Europe,  it  has  been  thought  advisable  to  carry  out  the  parallel  degrees  of  Reaumur's 
scale,  by  dote  on  the  drawing  of  the  tube.  This  table,  therefore  comprises  in  itself 
BIX  distinct  tables,  assuming  the  necessity  for  each  scale  to  be  represented  in  whole 
degrees-with  the  additional  advantages:  Ist,  that  the  space  occupied  is  smaller,  and 
the  othLTwIf  sclfel^  fractional  part  of  a  degree  on  one  may  be  at  once  determined  on 

^  It  is  extraordinary,  considering  the  great  advances  which  have  been  recently  made 
in  physical  science,  and  in  the  manufacture  of  philosophical  instruments,  that  the  makers 
of  thermometers  should  still  adhere  to  the  ofd  and  absurd  practice  of  marking  on  the 
Farenheit  scale,  the  unmeaning  words  Temperate,  Summer-heat,  Blood-heat,  Fever- 
heat,  Spirits  boil,  Ac,  when  the  instrument  might  be  easily  made  to  convey  a  large 
amount  of  information  in  respect  to  climate,  as  it  is  dependent  on  temperature.  Thus  the 
mean  temperature  of  England,  Ireland,  and  Scotland,  with  the  maxima  and  minima,  m 


B3a 


THERMOMETER. 


THERMOMETER. 


839 


CENTIGRADR 


REAUMUR. 


FAHRENHEIT. 


CENTIGRADE. 


REAUMUR 


FAHRENHEIT. 


Cblor.  Cyanogen  toL  190 

Tte  and  Imd,  p.  c  m. ;  also  Alloy  18  T.  4  L. 

(Phunben'  solder). 

dat.  loL  Chloride  zinc  boila. 


Alloy  4  T.  1  L.  m. 

Oxalic  etlier,  b.  1  -09. 
Salphuric  acid,  1*67  boila. 

pr.  steam,  10  at 


Pannaphthallne,  m.,  aHoy  13  T.  4  L.  melts. 
Oil  of  oranges,  b.  0-835. 

Starch  converted  to  dextrine. 


180 


pr.  steam,  9  at. 
Tup.,  ▼.  63-8>    Salphuric  acid  165  binls. 

AUoy  10  T.  4  L.  m. 

AHoy  9  T.  4  L.  m. 

pr.  steam,  8  at 

AHoy  8  T.  4  L.  m. 

Alloy  7  T.  4  L.  m.  yjQ 

pr.  steam  7 '6  at. 
Alloy  I  B.  3  T.  m. 

pr.  steam,  7  at 

AUoy  8  B.  38  L.  34  T.  m. 

Oil  elemi,  b.  0-853. 

pr.  steam,  6.5  at 


yg.  ttetm,  0  at    Fusible; 


Elast,  A.  V.  137.  38. 

Alloy  8  B.  33  L.  36  T.  m.  1  gn 
AUoy  8  B.  33  L.  34  T.  m. 


Elaat  A.  V.  131  -67. 

Fulminating  silver  explodes. 

pr.  steam,  6*6  at 

Zlast  A.  V.  126.86. 

Elast  Turp.  v.  33-6. 
pr.  steam,  6  at. 

Elast  A.V.  UO.OS. 


Slaat  Turp.  ▼.  30.    Sat.  nit  lime  boils. 
Sulphur  bums  feebly. 

Elast  A.  V.  114-l.V  IRQ  , 
Terbromide  Silicon,  b. 
4  pta,  Nlphnrie  add,  aad  1  pt  water  mixed ;  pr.  steam,  4-5  at 

Mastich  resin,  m. 

Alloy  8  B.  16  L.  18  T.  m. 

Kut  A.  y.  108*31 ;  Temp,  of  certain  factories. 

Nicotine  distils. 
pr.  steam,  4  at 

Elast  A.  v.  103.45. 

Fulminating  gold  explodes. 

AUoy  8  B.  16  L.  14  T.  m. 


pr.  steam,  3*6  at 
Cblor.  cyanogen,  m. :  S.  G.  t  -33.  i^q 

Grape  sugar  to  Caramel. 
Elaat  A.  V.  90.99. 


Sat  oit  ammonia  boils. 


pr.  steam,  3  at 
Pimeiic  acid,  m. ;  Xlast  A.  T.  79-94. 


pr.  steam,  IS  at 
372  Zinc  pnlTerirabie. 

ArseniouB  acid  vol :  Saliculous  acid  k 

Dichlor.  carbon,  b.  d.  ■».  4"7. 

pr.  steam,  1 1  at 

Fulminating  mercury  explodes. 

AUoy  16  T.  4  L.  m. 

362  Alloy  14  T.  4  L.  m. 
Elast  Turp.  V.  60.8. 
Alloy  13  T.  4  L.  m. 

Arsenic  vol. :  sugar  melts ;  hydrnret  of  bentule  i 
Succinic  acid  meiU. 


Chloride  benzole,  m. 


352 


Alloy  8  B.  33  L.  84  T.  m. ;  Citrilene  b.  0- 

AUoys  6  T.  4  L.,  and  ]  1  T.  4  L.  m. 

Sulphuret  solid;  iodine  boils,  d.  r.  8*69. 

Malic  acid  m. 

Alloy  8  B.  33  L.  36  T.  m. 

Oil  of  lemons  boils, 0-848. 
Oil  of  Cascarilla  b.  0  938. 
Alloy  8  B.  30  L.  34  T.  m. 

.  342  Caoutcboucine  boils. 
Elast  Turp.  V.  47*3. 

Sat  acet  potash  boils;  enpion  b. 
Alloy  6  T.  4  L.  m. 

222  •A.lloy  8  B,  33  L.  38  T.  m. 

Oxalic  acid  vol.;  elast  turp.  V.  43*1 
Alloy  8  B.  33  L.  30  T.  m. 


322 


AUoy  8  B.  33  L.  40  T.  m. 

AUoy  8  B.  33  L.  38  T.  m 

Naphtha  boils ;  aUoy  8  B.  36  L.  24  T.  m.,  alao  8  B.  99 1. 9S  T. 

Prussian  blue  decomposed. 

AUoy  8  B.  16  L.  34  T.  m. 

Oil  of  turpentine  boils  0*86 ;  dens.  Y.  4*7. 

„       Alloy  8  B.  16  L.  33  T.  m. 
viii  Quinine  m. 

Alloy  8  B.  30  L.  34  T.  m.  J  oU  juniper  b 

AUoy  8  B.  32  L.  34  T.  m. 

Rect  petroleum  b. 

Carb  not  sat  boHa    J  ^  "*'>'■  «  B.  16  L.  10  T. 
carb.  pot  sat.  boils,  j  ^^j  g  g  jg  l.  go  T.  m. 

202  ETHERIFICATION  ends;  latent  heat;  tAhn  rap. 

Alloy  8  B.  16  L.  8  T.  m. ;  camphilene  b.  86. ;  tngu  of  milk  m 

Asphaltum  melts;  camphor  melts,  d.  t.  6*31. 
Zinc  malleable. 

AUoy  8  B.  16  L.  13  T.  m. 

292  Alloy  8  B.  16  L.  16  T.  m. 

Gypsum  converted  to  plaster. 
Sulphuric  acid,  1*53  b. 

Elast  A.  V.  96*64. 

Tin  and  bismuth,  p.  r.  melt;  ancc.  acid  toU 

pr.  steam  locomotive  boilers. 
2g2  ETHERIFICATION  begins. 


Cholesterine  mehsk 
Elast  A.  V.  86-47. 

Oil  black  mustard  b. ;  maleic  acid  m. 

Peucyl  b.  0*80. 

b-.272 


PUoridaina  solid.    AUoy,  8  B.  10  L.  8.  T.  m.  ,»«. 
Camphoric  acid  r. 
pr.  steam,  3-6  at 

Elast  A.  V.  69*73. 

Sabacic  acid  m.;  Elast.  alch.  r.  166*3. 

Sat  mur.  ammonia  boils. 

Sat  acet  soda  boils. 

Pyromeconic  acid  m. 
Elast  A.  V.  60-06. 

pr.  steam,  3.  at  ' 

Sat  nit  soda  boils. 

Cinnamic  acid  m.;  caoutchouc  melts.  120  ■ 
Alloy  6  B.  I  L.  4  T.  m. 


Sat  cblor.  strontium  boils. 
Elast  A.  V.  61*34. 

Byrvp  boils  86  per  cent ;  chlor.  calcium  sat  boils. 

Elast  A,  V.  47*3, 
Alloy  8  B.  8  L.  4  T.  m. 

Chloric  ether  1,837  boils;  pr.  steam,  1  -6  at 

Elast  A.  y.  43-34. 

Xlaene  b.;  Elast  alch.  t.  94*1.  HO 
Phloridzine  m. 

Elast  A.  V.  39*69. 
Alloy,  8  B.  8  L.  3  T.  m. 

Oxalhydric  acid,  b.  1  -375. 

Water  of  the  Dead  Sea  boils. 

carb.  aoda,  chlor.  of  barium,  and  chlorate  potash  boil. 

Salicioe  m.;  nitric  acid,  I'lSb. 

Hur.  acid,  1*136  b.  ' 

Sjrrup  boils  63  per  cent  sugar. 

Chlor.  alumina  boils;  water  boils,  bar.  31  313*76. 
Glauber  salt  sat  boils. 
el  1  pt  ice;  4  sulphuric  acid;  pr.  steam,  1  at.  inn. 

100airat33«'=137-6.]  ■*"" 

Elast  A.  ¥.=30  S.  G.  636.]         Water  boils  bar.  39  in. 

Perox.  chlor.  explodes. 

W.  B.  MADRID. 

W.  B.  EL  SATTRE  (between  Dead  Sea  and  Akabah.) 

COMAGILLAS.    Mexican  Springs. 

W.  B.  GAVARNIE  PYRENEES. 

▼olcanic  mud;  JORULLO,  S.  AMERICA. 

Oxychlorocarbonic  ether  b. 

Elast  ether  vap.  166;  Elast  A.  V,  23-64. 

W.  B.  MEXICO. 

7471  ft.  eL 

W.  B.  SANTA  FE  BE  BOGOTA. 

8730  ft  el.     90—1 
Water  boils ;  CONVENT  ST.  BERNAND. 

9734  ft.  d. 

W  B.  FARM  OF  ANTI8ANA  Andes,  13,000  ft.  eL 

Chloric  ether  b.  I  ■34. 
W.  B.  aource  of  Oxus,  CENTRAL  ASIA. 
(16,600  ft.  elev.) 

Elast  A.  V.  16*16. 

G«yier  Springs,  Ireland. 
Xlast  A.  V.  14-8. 


Syrup  sat  boils. 

Corrosive  sublimate  rolatilised. 


Elast  A,  V.  74-79. 

Margaritic  acid  ;  castor  oil  m. 
Elast  alch.  V.  166-1. 
Syrup  boils  80  per  cent  sugar. 
.  262  ^*'*-  tartrate  potass  boils. 

Sat  nitrate  potass  boils;  heat  borne  by  Sir  J.  Banks  and  Dr. 

Hydriodic  acid  boils  1  -7 ;  also  hydrobrom.  acid  1'6.         '*•■•* 
Elast  A.  V.  64*83;  pimaric  acid  m. 

AUoy  8  B.  8  L.  6  T.  m. 

■  252  ^'^"'^  ■*^"'  ''*2  '»<>''•■ 

Elast  alch.  V.  133-3.  ;  dichL  carbon  t. 

Benzine  melts ;  hyd.  acet  acid  boils  (Tomar). 
Elast  A.  V.  66-64. 

Heavy  muriatic  ether  b. 
Elast  alch.  V.  118-8. 


-242 


Heat  of  fluid,  beeswax.    80' 
Xltat  alch.  Tap.  30 is.  S.  G.  0-SlX 


Alloy  8  B.  8  L.  6  T.  m. 

Sulphuric  acid  1  -30  b. ;  pyrogaUic  acid  m. 

Veratrine  and  benzaraide  m. 
Accumulated  temp,  of  air,  EDINBURGH 
Acet  acid  1*063  boils;  nit.  acid  1-30  b. 

Syrup  boils  84  per  cent  sugar. 


'232  Sulphur  melts,  d.  t.  6-65;  bensoine  m. 
Benzoic  acid  melts,  d.  v.  4-37. 
Salicine  m. 
Zinc  malleable;  heat  borne  by  Delaroch*. 

Sat  chlor.  sod.  boils. 
Sat  chlor.  pot  boila. 

Sat  phos.  soda  boils. 
-non  Muriatic  acid  1  047  b. ;  Elast  A.  T.  36*86. 
XCi  Accumulated  temp,  of  air,  GENEVA. 

Asphaltum  soft;  iodine  melts;  elast  ether  V.  S4a 

Elast  A.  V.  33*09  inches  mercuiy;  grape  sugar  m. 
Osmic  acid  volatilised. 
Sylvic  acid  m. 

Water  boils  lOM  ft.  dep. ;  se1eni-im  melts;  water  boils  Kar.  SL 
Water  boils,  328  dep. ;  W.  B.  DEAD  SEA  and  SEA  of  TlBX- 
•01 9  Water  boils  bar.  30.  rRIASL 

*^'«  Water  boils  631  ft.  elevation.  l»»«»* 

Water  boils  1064  ft.  elevation;  osmic  acid  melta. 
Water  boils  1600  ft.  elevation;  Reikiavik  spr. 
Water  boils  2138  ft.  elevation. 

Water  boils  2678  ft.  elevation  ;  aUoy  8  B.  6  L.  3  T.  ■. 
Water  boils  3221  ft  elevation. 
Water  boils  3766  ft.  e!e-/ation. 
Water  boils  4313  ft.  elevation. 
Water  boils  4863  ft  elevation. 
•202  Water  boils  6415  ft.  elevation. 

Fusible  metel,  8  R  6  L.  3  T.  m. ;  chloral  b.  d.  t.  S. 
-  Elast  alcb.  Taps.  63. 

I^j  W.  B.  St  Gothard,  6807  ft.  elevation. 

W.  B.  Mt  WUUam,  AUSTRALLl,  8300  ft.  eL 

Water  boils  at  Quito,  9341  ft.  el 

Sodium  melts;  Trinchera  springs  S.  AMERICA. 

•  192  Water  boils  summit  of  Etna,  10,955  ft.  eleT. 
Elast  ether  vap.  134*8 ;  akh.  Tap.  43*8. 

Alcohol  b.  0*967, 85  per  cent 

Nitric  acid  1  *638  boils ;  alcohol  b.  0*968, 30  pr.  e. 
Ozokerite  ni. 

182  Water  boils  Mont  Blanc  summit,  16,630  ft.  eL 
San  Germano  bath,  NAPLES. 
Starch  dissolves ;  alch.  b.  0-870,  71  per  cent 
AIX  LA  CHAPELLE,  spr.  max.  t 
Latent  heat,  petroleum  Tap.,  also  oil  Pajf. 

|—  Alcohol  boils,  0-736,  86  per  cent 

Tliermal  spr.,  I.  LUCON. 
Alcohol  boils,  0-794,  also  0*818, 94  per  oeofc  to  Iflft 
■  173  Naphthaline  melts. 


840 


CENTIGRADEL 


THERMOMETER. 
REAUMUR. 


FAHRENHEIT. 


THERMOMETER. 


841 


Pitch  melta. 
Tapor  bath,  FINLAND,  max.  t. 

Fercblor.  carbon  rap.  l-Sft. 

Uelenine  in. 

lUat  A.  V.  9*4«j  ether  Tap.  80.3. 

Starch  converted  to  sugar. 


70  _I 


Baden  Baden  Springs,  max.  C 

CALPEE,  1NI>IES,  max.  t 
BAGNKRES  DE  LUGHON,  epr. 

Ihwt  A.  V.  7-48.,  S.  O.  017;  ether,  rap.  67&         H 


Albnraen  opaline. 
Elast  A.  V.  6-87.  , 

Heat  of  fluidity  Spermaceti        .-I 

Heat  of  fluidity  nulphur. 

Vapor  bath,  RUSSIA. 

Chloroform,  b.  d.  v.  4-3. 

Htele  Mid  {1-6)  68  pts.  water,  13  pU.  from  60«.  60— | 

Mariana  aprings,  S.  AMERICA. 

Zlaat  ether.  Tap.  61.9.  I 

•"I 

BARBARY,  max.  t, 
Abietic  arid  m. 

Ammonia  0-936  b. 
Elaat,  A,  V.  43. 

OASIS  OF  MOORZOUK,  max.  t. 

FEZZAN,  AFRICA,  max.  t. 

Terchlor.  silicon,  b. 
BAGNERES  DE  BIGORRE,  apr. 
Amalgam  8  B.  6  L.  3  T.  and  3  mercury  m.  50~| 

Concent,  sulphuric  acid  evaporates. 

Palmitic  acid  no. 

Hamman  Ali  springs,  BARBART. 

PAMPAS,  SOUTH  AMERICA. 

CXNTRAL  AFRICA,  «,  t;  BASSORA,  max,  t  ' 
PONDICHERRY  max.  t 

-,,, ■    Chloronapbthalese  m. 

PHILOX,  EGYPT,  CAPE  OF  GOOD  HOPE,  max.  t. 

Myrtle  wax  m. 
SENEGAL,  8.  t.         ^1 
BAREGE,  spr.  ' 

MADRAS,  CAIRO,  max.  t 

Onmartoi  spring,  GREENLAND. 
GUADALOUPE,  max.  t 
PARIS  1793,  EQUATOR,  max.  t. 
_  Eupion,  b  0"%.  -  • 

OUAHAXUATO  MINES,  1700  ft.  deep,  7034  ft  el.  I 

MEXICAN  MINES,  max.  t         "' 
8TRA3BURG,  VIENNA,  max.  t    *Man,  min.  t. 

TE.XAS,  8.  t.  , 

MARTINIQUE,  max.  t       —  I 

STOCKHOLM,  max.  t  1 

Consol  mines.  CORNWALL,  1740  ft. 

COPENHAGEN,  WARSAW,  max.  t. 

EAUX  BONNES,  Pyrenees. 

max.  t.  o«"  SURINAM, 

ROCHAT,  spr. 

CAIRO,  s.  t.         H 
IS.  MALTA,  EGYPT,  m.  s.  t.  on 
PONDICHERRY,  m.  t   '^' 
Schlangenbad  Spa, 

CUMANA,  m.  t 

BRAZILS,  m.  t ;  BARBARY  m.  s.  t. 
CEYLON,  SENEGAL,  BATAVIA,m.  t 

MADRAS  m.  t.  ■ 

CONGO,  MANILLA,  BENARES,  HAVANNA,  m.  t.         J 

BOMBAY,  m.  t;  ITALY,  ro.  a.  t  Date  tree,  VERA  CRUZ.         "" 
Artasian  well  (300  ft.),  BRAZILS,  JAMAICA,  m.  t. 

RIO  JANEIRO,  m.  t. 
CANTON,  MACAO,  m.  t. 

BAGDAD,  m.  t         —I 
AMebyde,  b.;  CARACCAS,  CAIRO,  m,  t. 


Sqrcbellet,  rati,  t 


Ehut.  ether  vap.  93-«,  alch.  b.  92  per  cent  0  -SIT 
Elast.  A.  V.  ll-fi. 

Phoaphorus  bnma  violently ;  acetic  ether  U 
OU  of  cedar  melu,  Carlsbad  Spa. 

Elast.  A.  V.  10-4. 
162  H^t  of  fluidity  lead. 

Albumen  coaguL;  acetic  ether  boils;  Pisciarelli  ipriqp.NAPLCi 

Kochbrunnen,  Wisbaden. 
Stearic  acid  melts. 

Elast.  A.  V.  8-4. 

STEAMBOAT'S  ENGINE  ROOM,  W.  INDIES. 
HECLA,  EARTH  AT  SUMMIT. 
252  Thermal  epr.,  TAJURAH  AND  SHOA. 

White  wax  melU;  pyrox.  spirit  boils. 
Wiesbaden  Spa;  hydriod  ether  b.,  S.  G.  1-93. 
Plombieres  spr. 

Ambergris  spr. 

Ischla  springs,  NAPLES;  Leaker  spr.  6000  ft.  eL 
__  Aix-Ia-Cliapello  Spa. 

I",  J42  ^*"o*  "fax  melts. 

Ammonia  0-94  boils;  pyroxylic  sp.  h.  0-833 ;  elast  A.  V.  ••»4 
Bluriatic  acid  1-19  boils. 

UPPER  EGYPT,  in  a  tent;  Aries  spr. 
Elast  A,  V.  6-14. 

Margaric  acid  melts. 
Formic  ether  b.  S.  G.  916. 
J32  Atelone  boils  (pyroacetic  spirit). 
Oleene  boils. 

Potassinm  melts;  vapor  bath  ends. 
Berger  in  vapor  bath  13  min. 

Jorullo  springs,  S.  AMERICA;  MYNPOOREE,  max   t. 
Sands  at  S.  Fernando,  S.  AMERICA,  air  lOl* 
Stearic  and  oleic  acids  (mixed)  melt,  BELBEIS,  XGYPV 
Mutton  suet  melts;  Cauterets  spr. 
Kntakekaumene  spr. 
122  Styracine  m. 

Stearine  and  cetine  melt;  myristic  acid  m.;  elaat  A.  V.  3*38. 

Palmitic  acid  m. 

Bath  springs,  max.  t;  supposed  depth  3,360  ft.  *Lark. 

Bromine  boils  ;  hot  pump  at  Bath,  dens.  Br,  V.  6'64. 

Elms  Si)r.  max.  t 

King's  bath  at  Bath,  laurine  m. 

Sol.  ammonia  boils  0*91. 
112  Spermaceti  melts ;  Muscat  eprings. 

♦Duck,  *guinea  fowl,  *raTen. 

"^Pigeon;  PEKIN,  max.  t. ;  Vichy  apr.  max.  t 

C.  fowl ;  Cross  bath  at  Bath. 

*Bird»,  lOS-*,  lU". 

Sulpli.  carbon  boils. 

Coldblooded  animals  die. 

Temp,  for  incubation;  elast.  ether  van.  30  inches 

"^Slieep  and  pig,  owl ;  pliosjihorus  melts. 
102  *■*!'*•  "^"S"  P"»t»  artificial  mcubation. 
*  '*Animal8,  man,  max-  t ;  ox,  infant  child. 

^Squirrel,  rat,  cat,  jackal,  panther. 

*Bat,  liare, tiger,  horse,  elephant;  elast  A.  V,  I'M. 

Warm  bath  ends,  vapor  batli  commences. 
'*Temp.  man,  kite  (birds). 

Blood  heat,  hedgehog,  dnrmou.<>e.  [V.  a^flg. 

Tepid  bath  ends,  warm  bath  begins;  Ether  boils  0*734;  dena. 
Oil  of  roses  melts  ;  cocoic  acid  m. 
^  PUTREFACTION  rapid.     Old  palm  oil  m. 
92  VALENCIANA  MINE,  MEXICO;  Grenelle  well,  1,794  ft. 
Elast  A.  V.  1-36;  Pold ice  mine. 
Tallow  melts. 

ACETOUS  FERMENTATION, 
PETERS B  URG,  max.  t ;  oil  nutmegs  m. 
Kaisareyeh.  ASIA  MINOR.  4,200  ft.  el. 

Tepid  bath  begins.  Cacao  butter  m.  [1498  fV 

*Tortoise,  Cornish  mines,  Buxton  Spa,  DALCOATH  MINM 
"Serpents,  SEA  EQUATOR,  83-7. 
on  Nitrous  acid  1-42  boils;  Buxton  bath,  ALGIERS,  s.  t 
•S^  EQUATOR,  m.  t  81-6 1  *oy9ter,  snail  (Tropics). 

Phosphorus  luminous  in  pure  oxygen;  NAPLES,  s.  t 
Prussic  acid  boils  0-69,  [£|,  A.  ▼.  1 

Prog,  shark,  flying  fish,  scorpion  (Tropics). 
Insect!!,  silk  wo.-ms  hatched,  germination. 
Bristol  Spa,  temp.,  wasp. 

MEXICAN  MINES  1,650  ft.  deep;  SYDNEY,  a.  t 
Glow  worm,  cricket ;  PRUSSIAN  MINES,  880  ft. 
Artesian  well,  GRENELLE,  1,300  ft.  deep. 
72  MONKWEARMOUTH  MINE.  1,600  ft,  deep. 


CENTIGRADE. 


REAUMUR. 


FAHRENHEIT. 


20- 


SANTA  CRUZ,  TENERIFFE. 

Hypon.  ether  b. ;  iodine  vaporised. 

Elast.  A.  V.  0-731, 

Cotton  tree;  ALGIERS,  m.  t 

Gipps  land,  AUSTRALIA,  MALTA,  m.  t. 

CAPE  OF  GOOD  HOPE,  FUNCHAL,  m.  t 

Elast  A.  V.  0*616. 

CultiTation  of  Tine  ends, 
ENGLAND,  m.  b.  t  63-6. 

TOULON,  m.  t 

Elast  A.  V.0-S2;  ROME,  NICE,  m.t 

tflLTILLS,  I.  (max,  t)    NISMES,  GENOA,  LUCCA,  m.  t 

PERPIGNAN,  MONTPELIER,  m.  t 

Waterford  mines,  774  ft.  dep.  MARSEILLES,  m.  t 

LISBON,  BOLOGNA,  BORDEAUX.  AIX,  VENICE,  m.  t 

LYONS,  VERONA,  MILAN,  m.  t 

PAU,  in.  t    LOWER  EGYPT,  w.  t 

AMSTERDAM,  PEKIN,  NEW  YORK,  m.  t 

m.  t  NANTES,  ST.  MALO, 

MALTA,  w.  t ;  m.  t  BRUSSELS. 

PENZANCE,  m   t      in 

Cultivation  of  vine  begms,  PARIS,  LONDON,  m.  t     ■"■"' 

Elast  A.  V.  0-37.,  S.  O.  01. 

Salt  nriines  CRACOW,  730  ft. ;  Muriatic  acid,  40  at  Liq,  ) 

Sulphur,  hyd.  17  at ;  ammonia,  6*6  at  ) 

EDINKURGH,  BERLIN,  DUBLIN,  m.  t 

INVERNESS,  COPENHAGEN,  m.  t 

COVE  CORK,  w.  t,  m.  t  TORONTO, 

MONT  PERDU,  PYRENEES,  II. -265  ft  eL 

UPSAL,  STOCKHOLM,  QUEBEC,  m.  t 

CANADA,  m.  t     E List  A.  V.  0-263. 

CHRISTIANIA,  DRONTHEIM.m  t 

Hybernation  of  animiils. 

PETERSBURG,  m.  t;  Etna  sum.  10.956  ft.  el. 

KASAN,  ni.  t 

POLAR  SEAS  360  ft  deep. 

BERGEN,  PADUA,  COLUMBIA,  r.  w.  t 

MOSCOW,  m.  t ;  oils  freere.  ALTEN,  NORWAY,  m.  t 

(Carbonic acid  hq. 36 at),  N.CAPE  LAPLAND,  LABRADOR, 

Elast   A.  V.  0  2  inclies,  S.  G.  005. 

CUMBERLAND,  HO.  N.  A.  m.  t 

Eartli,  YAKUTSK.  3.M)  to  38-2  ft  dep. 

CHIMBORAZO,  18,6fl0  ft  el, 

MONT  BLANC,  if> fi'M  ft. 

HIMALAYAS,  18,01)0  ft  el. 

IRKUTSK,  m.  t 

SIBERIA,  m.  t. 

Earth  YAKUTSK,  77  ft.  dep 

AIR.  m  t  POLAR  SEA 

NOYA  ZEMBLA,  m,  t,  PORT  ENTERPRISE,  w,  t 

Aniiyd.  sulphitrous  acid  boils. 

Oil  of  turpentine  freezes,     JQ  • 


LoTest  natural  temperature  at  YAKUTSK  in  Siberia. 
— 72=84''  below  this  scale. 

CENTIGRADE  TO  FAHRENHEIT. 

Above  Ice.  Between  Ice  and  Zero. 

CXl'8+33.  33  (CXl'S). 

Below  Zero. 

Cxt'S— 32. 


Water  boile  in  vacuo,  *crab. 

VINOUS  FERMENTATION,  butyrine  melta,  CAIRO  WELL 

DURHAM  COAL  MINES,  'MfO  ft.  [310  ft.  im^. 

Cocoa  nut  oil  liquid,  Matlock  bath.  Grotto  del  Cane. 

CORDILLERAS,  ANDES,  m.  t  ."i.OOO  ft.  el. 

Matlock  springs,  CUMBERLAND  COAL  MINES,  600  ft. 

SAXON  MINES,  1,246  ft ;  Bakewell  spring*.  [it- 

i  MADEIRA,  m.  w.  t;  air  centre  of  Atl.  waters  of  the  ScajBa» 
NAPLES,  m.  t  Temp,  for  sick  rooaxg. 

^     DEEP  MINES,  EUROPE;  sea  bnuk  of  AguiUas. 
■02    PARAMATTA,  N.  S.  W.  m.  t ;  ALGIERS,  w,  t ;  aea  Aaoras. 

Fluoric  acid  boils,  anhyd.  chlorine  liqfd.  4  at 

Acetic  add  cryst ;  Puy  de  Dome,  3,600  ft. 

CAIRO  w.  t.  MINES  OF  BRITTANY  500  ft.,  BEKGEN  •■  t 

*Trout,  MEDITERRANEAN  SEA  2,000  ft,  decfk 

Vaucluse  fountain,  StiO  ft  el. 

Artesian  well  VIENNA,  200  ft. ;  Hanwell,390  ft. 

Camphor  floats,  elast  A.  V.  0  44. 

PIC  DU  MIDI,  9,660  ft. ;  JERSEY,  m.  t 
■52     ^''  ^^  aniseed  solid,  muriatic  ether  boils. 

CLER.MONT,  m.  t ;  Columbia  r.  m.  t  [beipae. 

ITALY,  m.  w.  t ;  VIENNA,  m.  t  60  6;  PUTREFACTION 

Liq.  ammon.  boils,  Sat  at  32;  STRASBURG,  m.  t 

WARSAW,  BERNE,  m.  t  [PRAGUE,  GENEVA,  aa.  t 

TENERIFFE  PEAK,  12,072  ft.  el. 

ZURICH,  GOTTINGEN,  LABRADOR,  s.  t 

Sulphurous  acid  liqfd.  8  at ;  protox.  nit  50  at;  Cyanogen,  30  at 

SEA  EQUATOR,  3.400  ft  deep. 
4n     DEEP  SEA,  common  springs,  HASTINGS,  w.  t 
■*•*     LAKE  OF  GENEVA,  1,0(»0  ft.  deep  ;   ROME,  w.  t 

LAKE  LUCERNE,  fi.=S0  ft.  deep  ;  *beetle,  PAU,  w.  t 

St  acid  freeze.s;  CARPATH.  MOUNTAINS:  mercury  evap. 

CAPE  HORN  SURFACE  OF  SEA,  max.  density  of  water. 

EDINBURGH,  w.t  ENGLAND,  m.  w.  t  37-8.  [w.  ^ 

Alcohol  boils  in  vacuo;  NOVA  ZEMBLA  s.  t,  SHETLAND 

Fixed  oils  freeze;  SOUTH  SEA.  1-J,420  ft.  deep. 

CAPE  HORN  SEA,  6,400  ft  deep. 

Mount  Argaeus,  ASIA  MINOR,  10,300  ft.  eL 
.32     ICE,  chlor  wr.  freexee,  sc.  ad.  3rd.,  hydr.  freei£t 

I'OLAK  SEA,  3,300  ft.  deep;  earth  YAKUTSK,  383  ft.  deep. 

Milk  freezes. 

CAKTHAGENA,  SPAIN,  w.  t 

Salt  water  freezes,  1,0-26  ;  vinegar  freexes;  formic  acid  freeew 

Earth  YAKUTSK,  217  ft.  deep. 

JUNGFRAU,  summit,  I2.72.i  ft. 

Blood  freezes,  earth  YAKUTSK,  119  ft.  deep. 

Eliiin  freezes,  HECLA  (Air)  at  summit,  6,110  ft.  A 
^22     O''  bergamot  freezes. 

Oil  cinnamon  freezes,  oleic  acid  (castor  oil)  frnaaw 
Wine  IVeesea, 

Earth  YAKUTSK,  60  ft,  dep. 

GUI.FBOTHNIA  AIR,  m.  w.  t :  Great  Bear  Lake,  m  t 

AIR  -23,000  feet  elevation  above  PARIS  (at  surface  SVi. 

Salt  water  freezes,  1-104. 
,„     RUSSIA,  m.  w.t 
•  I*     Prussic  acid  cryst  0  69  S.  O. 
ALTEN,  NORWAY,  w.  t 
N.  POLE,  m.  t  13  below  zero  (calc). 

Mercury  freezes.  I  40"  below  zero,  m.  w.  t..  at  KOTi 

Ether  Ik>iIb  in  vacuo.  )       ZEMBLA  AND  YAKUTSE. 

Carbouic  acid  freezes  148"  below  zero. 
Lowest  artificial  cold  187"  below  zero. 

FAHRENHEIT  TO  CENTIGRADE. 
Above  Ice.  Between  Ice  and  Zeio 

F-33  32-F 


1-8 


!•• 


Below  Zero 
F+W 


ABBREVIATIONS. 

m.  melts,  m.  t  mean  temperature,  w,  winter,  a.  eummpr.  at.  atmosphere,  b,  boils,  v.  rolatilized,  liq.  liqtiid, 
liqfd.  liquefied.  Ad.  acid.  max.  maximum,  min.  minimum.  Sol.  solution,  W.  B.  water  boils,  el.  elevation.  In 
reference  to  fusible  alloys.  B.  Bismuth.  T.  tin.  L.  lead.  pr.  pressure,  dep.  dej)re88ion.  I.  Island.  Vapr.  Vapoc 
Elast  Elasticity.  Fluid.  Fluidity.  Alch,  Alcohol,  Turp.  Turpentine,  dens,  aensity.  In  regard  to  places  meaa 
temp,  is  implied  where  not  expressly  stated,  r.  river,  spr,  spring,  fr,  freezes,  A.  V,  Aqueous  vapor,  d.  ▼ 
density  of  vapor.    S.  G,  specific  gravity.    The  Elasticity  of  Vapors  is  given  in  inches  of  Mercuiy. 

TEMPERATURES  ABOVE  THE  SCALE. 

Tin  and  Cadmium  m.  442«».  Tempered  Steel  (straw  color)  460°.  Sc.  ad.  1-78  b.  467o,  Bismnth  m.  476*.  Tempered 
Steel  (brown)  500°  Fixed  Oils  b.  SJO*.  Tempered  Steel  (red  and  purple)  550".  The  same  (blue)  600*.  Leadm.  612*>. 
Sc.  ad.  1-85  b,  648^  Mercury  b.  602*.  Zinc  m.  680«».  Gunpowder  explodes  700®.  Antimony  m.  8I0»,  Red  heat 
980«».  FKnt  glass  m,  1000^.  Heat  of  common  fire  1141o,  Brass  m.  1869®  Silver  m.  1873<».  Copper  m.  1996^. 
Gold  m.  8016*.    Cast  Iron  2786*.    Pure  iron  and  Platina  m.  3-380*.    Wind  furnace  white  heat  3300®. 


l( 


J» 


84!^ 


THERMOMETER. 


II 


well  as  the  mean  range  of  the  thermometer  throughout  the  year,  might  easily  find  a 
place  in  all  the  common  scales.  When  the  length  of  the  scale  would  admit  of  such  an 
arrangement  the  mean  temperatures  of  the  principal  cities  and  towns  of  Great  Britain 
as  well  as  of  foreign  climates,  might  be  attached,  with  many  interesting  points  in  ani- 
mal and  vegetable  physiology.  The  extensive  tables  on  temperature,  collected  and 
arranged  by  Sir  James  Clark,  in  hia  excellent  treatise  on  Climate,  would  here  serve  as 
a  useful  guide. 

It  will  be  seen  that  the  table  now  for  the  first  time  published,  ranges  from  12*^  to 
Z*I4P  Fahr.,  from— 11°  to -j-  190°  Centigrade,  and  from -9°  to  -j-  162'^  Reaumur.  It 
might  have  been  extended,  but  this,  it  was  considered,  would  have  rendered  it  of  very 
inconvenient  size ;  and  besides,  the  range  here  selected  comprises  all  the  most  remark- 
able  phenomena  connected  with  heat  The  more  important  facts  relating  to  tempera- 
ture above  and  below  this  range,  will  be  found  inserted  in  distinct  paragraphs,  on  the 
table,  with  formula  for  the  conversion  of  the  degrees  of  Centigrade  into  those  of  Fah- 
renheit, and  vice  versa. 

It  will  be  only  necessanr  to  state  generally  those  facts  which  the  table  is  intended  to 
illustrate.  They  will  be  found  arranged  opposite  to  their  respective  degrees,  either  on 
the  Centigrade  or  Fahrenheit  side,  according  to  the  space  afforded.  Some  points  have 
been  necessarily  omitted,  in  order  not  to  render  the  table  confused. 

Thus  it  has  been  impossible  to  introduce  all  the  maxima  and  minima  of  temperature 
in  respect  to  climate,  owing  to  the  spaces  being  already  occupied,  but  a  selection  hae 
been  made  of  some  of  the  most  important  of  these.  The  facts  connected  with  tempera- 
ture, placed  on  the  scale,  may  be  arranged  under  the  heads  of  Climatology,  Physical 
Geography,  Chemistry,  and  Physiology. 

Climatology.  1.  The  mean  temperatures  of  the  principal  countries,  towns,  and  cities 
in  the  world,  with  the  maxima  and  minima,  as  well  as  the  mean  summer  and  winter 
temperature  of  some  of  the  most  important  localities. 

2.  The  maximum  degrees  of  heat,  and  the  minimum  degrees  of  cold,  observed  on 
the  surface  of  the  globe,  including  the  accumulated  temperatures  of  air  at  Edinbui^h 
and  Geneva. 

,  Physical  Geography.  1.  The  temperature  of  the  atmosphere,  as  observed  on  the 
summits  of  the  principal  mountains  of  the  Old  and  New  World,  with  the  respective 
elevation  attached — at  the  sea  level  in  various  latitudes,  from  the  Arctic  to  the  An- 
tartic  seas,  as  well  as  in  deep  mines  and  other  excavations  in  Europe  and  America. 

2.  The  temperature  of  the  ocean  at  the  surface,  and  at  various  depths  12,420  feet, 
including  the  temperature  of  the  Polar  Seas,  of  the  Mediterranean,  Atlantic,  and  Pacific^ 
with  the  temperature  of  the  Gulf  stream. 

8.  The  temperature  of  the  waters  of  lakes  and  rivers  at  various  depths,  with  the  re- 
spective fathomings  attached. 

4.  The  temperature  of  the  strata  of  the  earth  at  various  depths,  observed  in  some  of 
the  deepest  mines  in  the  Old  and  New  World. 

6.  The  temperature  of  water  raised  in  Artesian  wells  in  Europe,  from  deptha 
varying  from  250  to  1*794  feet. 

6.  T^e  temperature  of  the  principal  thermal  springs  and  baths  observed  in  Europe, 
Africa,  the  West  Indies,  and  South  America. 

7.  The  temperature  at  which  water  boils  at  all  the  elevated  and  inhabited  spots  in 
the  world,  including  the  summits  of  the  mountains  of  Switzerland,  South  America,  and 
Central  Asia;  the  boiling  point  for  all  elevations  up  to  5416  feet,  and  for  1064  feet  de- 
pression below  the  level  of  the  sea. 

Chemistry.  1.  The  evaporating,  boiling,  fusing,  melting,  subliming,  and  congealing 
points  of  all  solids  and  liquids  in  chemistry,  from  12**  to  374'  Fahr.,  from  — 11°  to 
-|-190°  Cent  and  from  — 9  to  -f  155°  Reau.,  including  the  boiling  points  of  the 
saturated  solutions  of  numerous  salts,  and  the  melting  points  of  a  large  number  of 
alloya 

2.  The  temperature  for  fermentation  of  various  kinds,  malting,  putrefaction,  etherifi* 
cation,  and  other  chemical  processes. 

.  3.  The  boiling  points  of  alcohol  and  acids  of  various  specific  gravities,  with  the  re- 
spective densities  of  the  vapors. 

4.  The  pressure  or  elastic  force  of  the  vapor  of  water,  alcohol,  oil  of  turpentine  and 
"ether,  at  various  temperatures. 

6.  The  temperatures,  with  the  corresponding  pressures  required  for  the  liqnefactioB 
of  the  gases. 

6.  l!he  temperature  for  the  explosion  and  ignition  of  fulminating  and  combustible 
labstances. 

Physiology.  1.  The  maximum  degrees  of  natural  and  artificial  heat^  and  minimnm 
degrees  of  cdd,  borne  bj  man  and  animals. 


THERMOSTAT. 


843 


2.  The  temperature  of  the  body  in  man,  mammalia,  birds,  reptiles,  fishes,  and 
insects.  '^ 

3.  The  temperature  at  which  hybernation  takes'  place  in  certain  animals. 

4.  The  temperature  for  the  germination  of  seeds,  incubation,  the  artificial  hatching  of 
the  ova  of  birds,  fishes  and  insects. 

6.  The  temperature  for  the  growth  of  the  sugar-cane,  date,  indigo,  cotton  tree,  and 
for  the  cultivation  of  the  vine. 

6.  The  temperature  for  warm,  tepid,  and  vapor  baths;   the  vapor  baths  of  Russia 
and  Finland. 

As  the  value  of  a  table  of  this  kind,  depends  less  on  the  compiler  than  on  the 
observers  on  whom  he  relies,  I  feel  bound  to  state  that  I  am  chiefly  indebted  to  the 
following  authorities:— for  Climatology  and  Physical  Geography;  to  Humboldt,. 
Bonpland,  Saussure,  Boussingault,  Rose,  Ermann,  Baer,  Von  Wrangell,  Breislak, 
Phipps,  Scoresby,  Franklin,  Parry,  Back,  Ross,  Pachtusoff,  Zivolka,  Cordier,  Gay- 
Lussae,  Pouillet,  Biot,  Arago,  Bertrand,  Desfontainos,  Gerard,  Lhotsky,  Schomburgk, 
Davidson,  Forbes,  Brewster,  D'Abbadie,  Moore,  and  Beke;— for  Chemistry  and  Physi- 
ology; to  Berzelius,  Dumas,  Mitscherlich,  Gaultier  de  Claubry,  Peligot,  Davy,  Fara- 
day, Ure,  Brande,  Graham,  Turner,  Dr.  Davy,  and  Liebig.  In  respect  to  the 
department  of  Physical  Geography,  I  am  much  indebted  to  the  foreign  correspondence 
of  the  Athenaeum. 

^  Many  of  the  facts  I  was  enabled  to  collect  or  verify  by  personal  observation  during  a 
iourney  through  France,  Italy,  and  Switzerland.  Some  of  the  chemical  phenomena 
have  also  been  derived  from  direct  experiment  It  is  very  probable  that  a  few  of  the 
temperatures,  in  each  department,  will  be  found  to  differ  from  those  given  in  some 
works  on  Chemistry ;  and,  on  this  point,  I  have  one  remark  to  make,  namely,  that  the 
greatest  discrepancies  will  often  be  found  among  respectable  authorities  in  regard  to 
temperature.  It  is  impossible  here  to  enter  into  the  causes  of  these  discrepancies. 
I  have  invariably  acted  on  the  principle  of  selecting  the  best  authorities ;  and  where  these 
differed,  I  have  endeavored  to  arrive  at  an  approximation  to  the  truth  by  experiment, 
or  where  this  was  impossible,  by  seeking  for  corroborative  circumstances.  A  large 
number  of  observations,  made  by  travellers,  I  have  been  obliged  to  reject,  in  some 
instances,  owing  to  the  omission  or  confusion  of  the  -}-  and  —  signs ;  and  in  others,  owing 
to  the  observers  having  omitted  to  state  what  thermometers  they  employed.  During  the 
researches  into  which  the  compilation  of  this  table  has  led  me — occupying  as  it  has  done 
the  occasional  leisure  of  four  years— mj^  mind  has  been  strongly  impressed  with  the 
benefits  which  would  accrue  to  science,  if  the  philosophers  of  Europe  would  agree  to 
employ  only  one  scale,  with  small  degrees,  and  so  adjusted  as  to  render  entirely  un- 
necessary the  use  of  the  -|-  and  —  signs. 

THERMOSTAT,  is  the  name  of  an  apparatus  for  regulating  temperature,  in  va- 
porization, distillation,  heating  baths  or  hothouses,  and  ventilating  apartments,  Ac.; 

for  which  I  obtained  a  patent  in  the  year  1881.* 
It  operates  upon  the  physical  principle,  that 
when  two  thin  metallic  bars  of  different  expansi- 
bilities are  riveted  or  soldered  f&cewise  together, 
any  change  of  temperature  in  them  will  cause  a 
sensible  movement  of  flexure  in  the  compound 
bar,  to  one  side  or  other;  which  movement  may 
be  made  to  operate,  by  the  intervention  of  levers, 
Ac,  in  any  desired  degree,  upon  valves,  stopcocks, 
stove-registers,  air-ventilators,  Ac. ;  so  as  to  regu- 
late the  temperature  of  the  media  in  which  the 
said  compound  bars  are  placed.  Two  long  rulers, 
one  of  steel,  and  one  of  hard  hammered  brassy 
riveted  together,  answer  very  well;  the  object 
being  not  simply  to  indicate,  but  to  control  or 
modify  temperature.  The  following  diagrams 
will  illustrate  a  few  out  of  the  numerous  appli- 
cations of  this  instrument  :— 

i%.  1448  a,  6,  is  a  single  thermostatic  bar, 
consisting  of  two  or  more  bars  or  rulers  of 
differently  expansible  solids  (of  which,  in  certain 
cases,  wood  may  be  one):  these  bars  or  rulers 
are  firmly  riveted  or  soldered  together,  face  to 
face.  One  end  of  the  compound  bar  is  fixed 
.  .        ...  _,       ^        ,       y^y  ^^^^  at  a,  to  the  interior  of  the  containinfir 

Cistern,  boiler,  or  apartments,  almb,  whereof  the  temperature  has  to  be  regulate^ 


844 


THERMOSTAT. 


THIMBLE. 


845 


,  1 


1451 


and  the  other  end  of  the  compound  bar  at  6,  is  left  free  to  move  down  toward  e,  hy 
the  flexure  which  will  take  place  when  its  temperature  is  raised. 

The  end  6,  is  connected  by  a  link,  h  d,  with  a  lever  d  e,  which  is  moved  by  the 
flexure  into  the  dotted  position  6  g,  causing  the  turning-valve,  air-ventilator,  or  re- 
gister, o  n,  to  revolve  with  a  corresponding  angular  motion,  whereby  the  lever  will 
raise  the  equipoised  slide-damper  k  t,  which  is  suspended  by  a  link  from  the  end  e, 
of  the  lever  e  cl,  into  the  position  k  h.  Thus  a  hothouse  or  a  water-bath  may  have 
its  temperature  regulated  by  the  contemporaneous  admission  of  warm,  and  dischai^e 
->f  cold  air,  or  water. 

Fig.  1449  a  6  c  is  a  thermostatic  hoop,  immersed  horizontally  beneath  the  surface  of 
the  water-bath  of  a  still.  The  hoop  is  fixed  at  a,  and  the  two  ends  6,  c,  are  connected  by 
two  links  hd,cd,  with  a  straight  sliding  rod  d  h,  to  which  the  hoop  will  give  an  endwiso 
motion,  when  its  temperature  is  altered ;  e,  is  an  adjusting  screw-nut  on  the  rod  d  h,  for 
setting  the  lever  /  g,  which  is  fixed  on  the  axis  of  the  turning-valve  or  cock  /,  at  any 
desired  position,  so  that  the  valve  may  be  opened  or  shut  at  any  desired  temperature, 
corresponding  to  the  widening  of  the  points  b,  c,  and  the  consentaneous  retraction  of 
the  point  d,  toward  the  circumference  a  6  c  of  the  hoop,  g  h,  is  an  arc  graduated  by  a 
thermometer,  after  the  screw-piece  e  has  been  adjusted.  Through  a  hole  at  h,  the  guide- 
rod  passes;  «,  is  the  cold-water  cistern ;  ifk,  the  pipe  to  admit  cold  water;  I,  the  over- 
flow pipe,  at  which  the  excess  of  hot  water  runs  ofi; 

Mg.  1450  shows  a  pair  of  thermostatic  bars,  bolted  fast  together  at  the  ends  a.  The  free 
ends  6,  c,  are  of  unequal  lengths,  so  as  to  act  by  the  cross  links  d,  f,  on  the  stopcock  e. 
The  links  are  jointed  to  the  handle  of  the  turning  plug  of  the  cock,  on  opposite  sides 
of  its  centre ;  whereby  that  plug  will  be  turned  round  in  proportion  to  the  widening  of 
the  points  be.     h  g  a  the  pipe  communicating  with  the  stopcock. 

Suppose  that  for  certain  purposes  in  pharmacy,  dyeing,  or  any  other  chemical  art,  a 
water-bath  is  required  to  be  maintained  steadily  at  a  temperature  of  150°  F. ;  let  the 
combined  thermostatic  bars,  hinged  together  at  e,  /,  fig.  1451,  be  placed  in  the  bath,  be 

tween  the  outer  and  inner  vessels  a,  6,  c,  d, 
being  bolted  fast  to  the  inner  vessel  at  g  ; 
and  have  their  sliding  rod  k,  connected  by  a 
link  with  a  lever  fixed  upon  the  turning  plug 
of  the  stop-cock  t,  which  introduces  cold 
water  from  a  cistern  m,  through  a  pipe  m, 
i,  n,  into  the  bottom  part  of  the  bath.  The 
length  of  the  link  must  be  so  adjusted  that 
the  flexure  of  the  bars,  when  they  are  at  a 
temperature  of  150°,  will  open  the  said  stop- 
cock, and  admit  cold  water  to  pass  into  the 
bottom  of  the  bath  through  the  pipe  i,  n, 
whereby  hot  water  will  be  displaced  at  the 
top  of  the  bath  through  an  open  overflow- 
pipe  at  q.  An  oil  bath  may  be  regulated  on 
the  same  plan ;  the  hot  oil  overflowing  from 
5,  into  a  refrigeratory  worm,  from  which  it 
may  be  restored  to  the  cistern  m.  When  a 
water  bath  is  heated  by  the  distribution  of  a 
tortuous  steam  pipe  through  it,  as  i,  n,  o^p,  it  will  be  necessary  to  connect  the  link  of  the 
thermostatic  bars  with  the  lever  of  the  turning  plug  of  the  steam-cock,  or  of  the  throttle 
valve  i,  in  order  that  the  bars,  by  their  flexure,  may  shut  or  open  the  steam  passage 
more  or  less,  according  as  the  temperature  of  the  water  in  the  bath  shall  tend  more  or 
less  to  deviate  from  the  pitch  to  which  the  apparatus  has  been  adjusted.  The  water  of 
the  condensed  steam  will  pass  off  from  the  sloping  winding-pipe  i,  n,  o,  p,  through  the 
sloping  orifice  p,  A  saline,  acid,  or  alkaline  bath  has  a  boiling  temperature  proportional 
to  its  degree  of  concentration,  and  may  therefore  have  its  heat  regulated  by  immersing  a 
thermostat  in  it,  and  connecting  the  working  part  of  the  instrument  with  a  stop-cock  t, 
which  will  admit  water  to  dilute  the  bath  whenever  by  evaporation  it  has  become  concen- 
trated, and  has  acquired  a  higher  boiling  point.  The  space  for  the  bath,  between  the 
outer  and  inner  pans,  should  communicate  by  one  pipe  with  the  water-cistern  m ;  and  by 
another  pipe,  with  a  safety  cistern  r,  into  which  the  bath  may  be  allowed  to  overflow  du- 
ring any  sudden  excess  of  ebullition. 

Mg.  1454  is  a  thermostatic  apparatus,  composed  of  three  pairs  of  bars,  d,  d,  d,  which 
are  represented  in  a  state  of  flexure  by  heat ;  but  they  become  nearly  straight  and  parallel 
when  cold,  a  6  c  is  a  guide  rod,  fixed  at  one  end  by  an  adjusting  screw  e,  in  the 
strong  frame  /  «,  having  deep  guide  grooves  at  the  sides.  /  g,  is  the  working-rod, 
which  moves  endways  when  the  bars  d,  d,  d,  operate  by  heat  or  cold.  A  square  re- 
gister-plate h  g,  may  be  affixed  to  the  rod  f  g,  so  as  to  be  removed  backward  and  for- 


1453 


1454 


ward   thereby,  according  to  the  variations 
of  temperature;  or  the  rod  /  g,  may  cause 
the  circular  turning  air-register,  i,  to  re- 
volve by  rack  and  wheel-work,  or  by  a  chain 
and    pulley.      The    register-plate    h  g,   or 
turning  register  t,  is  situated  at  the  ceiling 
or  upper  part  of  the  chamber,  and  serves 
to  let  out  hot  air.     k,  is  a  pulley,  over  which 
a   cord   runs   to   raise   or   lower   a   hot-air 
register  I,  which  may  be  situated  near  the 
floor  of  the  apartment  or  hot-house,  to  admit 
hot  air  into  the  room,     r,  is  a  milled  head, 
for  adjusting  the  thermostat,  by  means  of 
the  screw  at  e,  in  order  that  it  may  regulate 
the  temperature  to  any  degree. 

Fig.  1455  represents  a  chimney,  furnished 
with  a  pyrostat  a  b  c,  acting  by  the  links 
o,  d,  e,  c,  on  a  damper  /  h  g.     The  more 

supposed  to  be  on  the  outside.     The  plan? Ttt'irp:Ula^  till'^hlsTar 

7trmVerurt:"^'^ '''''  ^'^  ^^^^^^^ ''  '"^^  ^-"^^^  ^'^^^^^^^  criTyt  in^eJ^: 

Fig.  1453  represents  a  circular  turning  register,  such  as  is  used  for  a  stove  or  stove- 

grate,  or  lor  ventjlatmg  apartments  ;  it  is  furnished  with  a  series  of  spiral  Th'ermosS^Tc 

bars  e^ch  bar  being  fixed  fast  at  the  circumference  of  the  circle  6,  c,  of  the  fixeT  nlate 

"55  of  the  air-register ;  and  all  the  bars  act  in  concert  at  the  centre  a,  of  the 

LTh  nl  ^*    ?f  '^^-  '^^'T'  ^^  ^^^'"  ^"^^  ^""S  inserted  between  the 
nt    1  .    K™^^^  ^1"'^"' '''  ^y  bemg  jointed  to  the  central  part  of  the  turn- 
ing plate  by  small  pms. 

^J'vh  ^.^^2  represents  another  arrangement  of  my  thermostatic  apparatus 
applied  to  a  circular  turning  register,  like  the  preceding,  for  veXS 

bv  meT.'of  7rvT'  «^^r P-"d  b-r«  are  appfied  so  as7o  actrconce^ 
by  means  of  the  links  a  c,b  c,  on  the  opposite  ends  of  a  short  lever  which 
IS  fixed  on  the  central  part  of  the  turning  plate  of  the  air-reS    The 

Z\lX^LTZf  '"'  «^-\^-tened  to  the  circ^flrence^o? 

the  faxed  plate  of  the  turning  register,  by  two  sliding  rods  ad,  be,  which 

are  furnished  with  adjusting  screws.     Their  motion  or  flexure  is  Trwis^ 

muted  by  the  links  a  c,  and  b  c,  to  the  turning  plate,  about  its  centre^o^ 

tnnr.       ,^      the  purpose  of  shutting  or  opening  the  venUkting*  sectorial  a^Jres 

more  or  less,  according  to  the  temperature  of  the  air  which  surrounds   he  thermosteS 

urning  register.     By  adjusting  the  screws  a  rf,  and  6  c,  the  turninrre%sterTs^^^^ 

to  close  all  its  apertures  at  any  desired  degree  of  temperature :  but  whenever  the  ^?l! 

THIMRrT?^'''"'"'  '"f  "^^'^2,^'^-  <^«'nP<'»nd  bars  will  open  t^e  apertures 
IHIMBLE  (-De  a  coudre.Fv.i  Fineerhut  ( Untrprhnt^    r^r.J.\   •     ^  "Hciiuiej*. 

metallic  cone  deviating  little  froi  a  ^^Ser,^^^^^^^^^^^^ 

middt  fiT  efofr  ^'Cc::z'i^s't7:ii^ :  r  «-?<>'  "^^ 

through  uoth  or  leather,  in  the  act  of  sewin^     Th^?  lim!  ff^  readily  and  safely 

two  ways;  either  with  a  pitted  round  erdTr^'withoit  one      he  l^n'"'  »^,S'^i«"ed  in 

thimble,  being  employed  by  tailors,  uphols  erers  and  Uner^lvlp^        ""^^^  '^.1  ^P^"" 

The  following  ingenious  process  for  makinl  S  pJllnf  ?  •     V  ^P^^^^"?'  ^^  needle-men, 

MM.  Rouy  and'Berthier,Tf  Paris  ha     h^^^^^^^  '}^  contrivance  of 

Sheet-iron,  one  twenty-fourth  of  an  inoh  tM^l  ?»ch  celebrated,  and  very  successful. 

to  the  intended  size^  thrthYmbles      T^e^e 'Jrin?    '"'"^  ^^"P/»  o^  dimensions  suited 

whereby  they  are  cut  into  LcsTrb^ut  2lLS.?^        .^^''^  ^"^"'' *  P^^^h-press, 

Each  strip  contains  one  dozen  of  these  Inkr^f  'l^'f  '''^''^''  ^^  *  ^*«- 

hot,  and  to  lay  them  on  a  mand/ilnfcely  fitted*  tolhei  i'e  '"rh'/w  'l  °^"'''  '""'"^  '.'^' 

the  middle  of  each  with  a  round-faced  Lnoh«hn„t/h    1\   ^^^  workman  now  strikes 

sinks  it  into  the  concavity  of  the  first  manSril      He  ^l    /'^"f  '•  ^''  ^""^''^  *"^  ^^" 

other  mandril,  which  has  five  hollows  ^f^nrL.^^^    -      *'^"'^"/  *'  successively  to  an- 

it  into  them,  brings  it  to  the  proper Iha^!^  mcreasmg  depth;  and,  by  striking 

A  second  workman  takes  this  rude  thimble  stiVVc-t  ;n  fK.»  «i.     i     /-l-    .    ..     . 
to  polish  it  within,  then  turns  it  outside  maVK  the  .r^       ?  "»f  ""^^llf  '^^^^' '"  ""'^ 

united  to  the  surface  of  fhe  i.^^^  by  re^l^TLtf i?  tf^Z'l^^^J^ 


846 


THREAD  MANUFACTURE. 


dril.    A  gold  fillet  is  applied  to  the  outside,  in  an  annular  space  turned  to  receive  it» 
>»eing  fixed,  by  pressure  at  the  edges,  into  a  minute  groove  formed  on  the  lathe. 

Thimbles  are  made  in  this  country  by  means  of  moulds  in  the  stamping-machine.  See 
Stamping  of  Metals. 

THORINA  is  a  primitive  earth,  with  a  metallic  basis,  discovered  in  1828,  by  Ber- 
xelius.  It  was  extracted  from  the  mineral  thorite,  of  which  it  constitutes  58  per  cent., 
and  where  it  is  associated  with  the  oxydes  of  iron,  lead,  manganese,  tin,  and  uranium, 
besides  earths  and  alkalis,  in  all  12  substances.  Pure  thorina  is  a  white  powder,  without 
taste,  smell,  or  alkaline  reaction  on  litmus.  When  dried  and  calcined,  it  is  not  affected 
ly  either  the  nitric  or  muriatic  acid.  It  may  be  fused  with  borax  into  a  transparent 
glass,  but  not  with  potash  or  soda.  Fresh  precipitated  thorina  is  a  hydrate,  which  dis- 
solves  readily  in  the  above  acids,  as  well  as  in  solutions  of  the  carbonates  of  potash,  soda, 
and  ammonia,  but  not  in  these  alkalis  in  a  pure  state.  This  earth  consists  of  74-5  parts 
of  the  metal  thorinum,  combined  with  100  of  oxygen.  Its  hydrate  contains  one  equiva- 
lent prime  of  water.  It  is  hitherto  merely  a  chemical  curiosity,  remarkable  chiefly  for  a 
density  of  9-402,  far  greater  than  that  of  all  the  earths,  and  even  of  copper. 

THREAD  MANUFACTURE.  The  doubling  and  twisting  of  cotton  or  linen 
yarn  into  a  compact  thread,  for  weaving  bobbinet,  or  for  sewing  garments,  is  performed 
by  a  machine  resembling  the  throstle  of  the  cotton-spinner.  Fig.  1138  shows  the 
thread-frame  in  a  transverse  section,  perpendicular  to  its  length,  a,  is  the  strong 
framing  of  cast-iron ;  6,  is  the  creel,  or  shelf,  in  which  the  bobbins  of  yam  I,  I,  are  set 
loosely  upon  their  respective  skewers,  along  the  whole  line  of  the  machine,  their  lowei 
ends  turning  in  oiled  steps,  and  their  upper  in  wire  eyes ;  c,  is  a  glass  rod,  across  which 
the  yarn  runs  as  it  is  unwound ;  d,  d,  are  oblong  narrow  troughs,  lined  with  lead,  and 
filled  with  water,  for  moistening  the  thread  during  its  torsion ;  the  threads  being  made 
to  pass  through  eyes  at  the  bottom  of  the  fork  e,  which  has  an  upright  stem  for  lifting 
it  out,  without  wetting  the  fingers,  when  anything  goes  amiss ;  /,  /,  are  the  pressing 
rollers,  the  under  one  g,  being  of  smooth  iron,  and  the  upper  one  h,  of  box-wood;  the 
former  extends  from  end  to  end  of  the  frame,  in  lengths  comprehending  18  threads, 
which  are  joined  by  square  pieces,  as  in  the  drawing-rollers  of  the  mule-jenny.  The 
necks  of  the  under  rollers  are  supported,  at  the  ends  and  the  middle,  by  the  standards  % 
secured  to  square  bases  j,  both  made  of  cast  iron.  The  upper  cylinder  has  an  iron  axis, 
and  is  formed  of  as  many  rollers  as  there  are  threads;  each  roller  being  kept  in  its  place 
upon  the  lower  one  by  the  guides  k,  whose  verticle  slots  receive  the  ends  of  the  axes. 

The  yarn  delivered  by  the  bobbin  /,  glides  over  the  rod  c,  and  descends  into  the  trough 
d  e,  where  it  gets  wetted :  on  emerging,  it  goes  along  the  bottom  of  the  roller  g,  turns 
up,  so  as  to  pass  between  it  and  h,  then  turns  round  the  top  of  A,  and  finally  proceeds 
obliquely  downward,  to  be  wound  upon  the  bobbin  m,  after  traversing  the  guide-eye  n. 
These  guides  are  fixed  to  the  end  of  a  plate  which  may  be  turned  up  by  a  hinge-joint 
at  0,  to  make  room  for  the  bobbins  to  be  changed. 

There  are  three  distinct  simultaneous  movements  to  be  considered  in  this  machine 
1,  that  of  the  rollers,  or  rather  of  the  under  roller,  for  the  upper  one  revolves  merely  by 
friction ;  2,  that  of  the  spindles  w,  «';  3,  the  up-and-down  motion  of  the  bobbins  upon 
the  spindles. 

The  first  of  these  motions  is  produced  by  means  of  toothed  wheels,  upon  the  right 
hand  of  the  under  set  of  rollers.  The  second  motion,  that  of  the  spindles,  is  effected  by 
the  drum  z,  which  extends  the  whole  length  of  the  frame,  turning  upon  the  shaft  v,  and 
communicating  its  rotary  movement  (derived  from  the  steam  pulley)  to  the  whorl  b' 
of  the  spmdles,  by  means  of  the  endless  band  or  cord  a\  Each  of  these  cords  turns  four 
spindles,  two  upon  each  side  of  the  frame.  They  are  kept  in  a  proper  state  of  tension 
by  the  weights  e\  which  act  tangentially  upon  the  circular  arc  <f ,  fixed  to  the  extremity 
of  the  bell-crank  lever  e' f  g',  and  draw  in  a  horizontal  direction  the  tension  puUeye 
A,  embraced  by  the  cords.  The  third  movement,  or  the  vertical  traverse  of  the  bobbins, 
along  the  spmdles  »/i,  takes  place  as  follows  :— 

The  end  of  one  of  the  under  rollers  carries  a  pinion,  which  takes  into  a  carrier  wheel 
that  communicates  motion  to  a  pinion  upon  the  extremity  of  the  shaft  m\  of  the  heart- 
shaped  pulley  n'.  As  this  eccentric  revolves,  it  gives  a  reciprocating  motion  to  the 
levers  o\  o ,  which  oscillate  in  a  vertical  plane  round  the  points  p',  p'.  The  extremities 
of  these  levers  on  either  side  act  by  means  of  the  links  q\  upon  the  arms  of  the  sliding 
sockets  r',  and  cause  the  vertical  rod  «',  to  slide  up  and  down  m  guide-holes  at  f,  u\  along 
with  the  cast-iron  step  v',  which  bears  the  bottom  washer  of  the  bobbins.  The  periphery 
of  the  heart- wheel  u\  is  seen  to  bear  upon  friction  wheels  x,  x\  set  in  frames  adjusted 
by  screws  upon  the  lower  end  of  the  bent  levers,  at  such  a  distance  from  the  point  p\ 
as  that  the  traverse  of  the  bobbins  may  be  equal  to  the  length  of  their  barrel. 

By  adapting  change  pinions  and  their  corresponding  wheels  to  the  rollers,  the  delivery 
of  the  yarn  may  be  increased  or  diminished  in  any  degree,  so  as  to  vary  the  degree  of 


THUNDER  CONDUCTORS. 


847 


1456 


twist  put  into  it  by  the  uniform  rotation  of  the  drum  and  spindles.    The  heart  motion 
being  derived  from  that  of  the  rollers,  will  necessarily  vary  with  it 

Silk  thread  is  commonly  twisted  in  lengths  of  from  60  to  100  feet,  with  hand  reek 
somewhat  similar  to  those  employed  for  making  ropes  by  hand 

THUNDER  CONDUCTORS.  The  several  nautical  and  scientific  conditions  which 
thesystem  of  lightning  conductors  in  ships  professes  to  satisfy,  are  as  follows:— 

The  conductors  are  capacious  and  always  in  place,  consequently  ready  to  meet  the 
most  unexpected  danger  at  all  times  and  under  any  circumstances  in  which  the  general 
fabric  in  all  ite  casualties  may  become  placed.  This  system  of  conductors,  whilst  being 
permanently  fixed  throughout  their  whole  extent,  still  admit,  upon  demonstrable  prin^ 
ciples  of  electrical  action,  the  perfect  motion  of  the  sliding  masts  one  upon  the  other,  or 
of  any  part  of  the  mast  being  removed,  either  by  accident  or  design,  without  for  an 
instant  interfering  with  the  protecting  power.  The  conductors  are  independent  of  the 
officers  or  crew  of  the  ship;  so  that  the  sailors  are  never  required  to  handle  or  replace 
them,  often  a  very  perilous  and  annoying  service.  The  conducting  plates  are  quite  clear 
of  the  standing  and  running  rigging;  the  whole  series  is  calculated  to  resist  external 
violence,  and  at  the  same  time  yield  to  any  flexnre  or  straim  incidental  to  the  spars  to 
which  they  are  applied.  Finally,  the  whole  system  is  so  arranged  that  a  discharge  of 
lightning  falling  on  any  part  of  the  ship  could  scarcely  enter  upon  any  circuit  in  its 
course  to  the  sea  of  which  the  conductors  did  not  form  a  part;  hence  has  arisen  that 
perfect  security  which  experience  has  shown  to  be  derived  from  such  a  system. 

In  the  original  conception  of  this  system  Sir  Snow  Harris  was  led  to  consider  the  elec- 
trical discharge,  as  seen  in  the  phenomenon  of  lightning,  to  be  an  explosive  form  of  the 
action  of  some  unknown  agency  in  nature  when  forcing  its  way  through  resisting  matter 
such  as  air,  all  vitreous  and  resinous  bodies,  and  some  other  kinds  of  matter :  whilst  in 
traversing  other  bodies  offering  but  a  very  small  resistance  to  its  progress^  this  explosive 


848 


TIN. 


TIN. 


it 


;i  iilili  i 


form  of  action  we  call  lightning  becomes  transformed  into  a  sort  of  comparatively 
quiescent  current  The  attempt  was  therefore  to  bring  a  ship  as  far  as  possible  into  that 
passive  or  non-resisting  state  which  she  could  possess  as  regards  the  electrical  discharge, 
supposing  the  entire  mass  were  metallic  throughout;  so  that  from  the  instant  the  agency 
of  lightning  struck  upon  any  portion  of  the  masts  aloft^  the  explosive  action  would  vanish, 
and  the  electrical  discharge  be  prevented  from  traversing  the  vessel  under  the  form  of 
lightning.  The  following  extract  from  the  official  journal  of  a  M.  S.  Conway,  23,  whilst 
proving  with  a  great  natural  experiment  in  common  with  numerous  other  cases  the 
truth  of  this  deduction,  is  of  no  ordinary  interest  in  practical  science : 

"Port  Louis,  Isle  of  France,  9th  March,  1846,  11  45  a.  m.  The  pendant  staflF  at 
Doain-top-mast-head  was  shivered  in  pieces  by  lightning,  Harris's  conductor  carrying 
oflr  the  fluid  without  further  damage." 

The  ship  was  refitting  at  this  time,  and  the  top-gallant  masts  on  deck,  so  that  a  small 
spar  was  set  up  at  the  top-mast-head  as  a  temporary  support  for  the  pendant;  this  spar 
had  not  consequently  any  conductor  on  it  It  is  seen  by  the  ship's  journal  that  the  spar 
was  shivered  in  pieces  by  the  explosive  action,  which  became  immediately  transformed 
into  a  comparatively  quiescent  current  on  reaching  the  line  of  conduction. 

The  report  of  the  thunder  was  as  if  one  of  the  main-deck  guns  had  been  fired.     The 
gunner,  who  was  sitting  in  his  berth  immediately  under  one  of  the  lateral  branches  of 
the  conductor  passing  through  the  ship,  saw,  through  the  scuttle  port,  a  brilliant  blaze 
of  light  from  the  ship  upon  the  sea,  but  experienced  no  inconvenience. 
TILES.    See  Bricks. 

TILTING  OF  STEEL.  See  Steel.  Rees's  Cyclopaedia  contains  an  excellent  article 
on  this  subject. 

TIN  (Etain,  Ft.  ;  Zinn,  Germ.),  in  its  pure  state,  has  nearly  the  color  and  lustre 
of  silver.  In  hardness  it  is  intermediate  between  gold  and  lead;  it  is  very  malleable, 
and  may  be  laminated  into  foil  less  than  the  thousandth  of  an  inch  in  thickness ;  it 
has  an  unpleasant  taste,  and  exhales  on  friction  a  peculiar  odor ;  it  is  flexible  in  rods 
or  straps  of  considerable  strength,  and  emits  in  the  act  of  bending  a  crackling  sound,  as  if 
sandy  particles  were  intermixed,  called  the  creaking  of  tin.  A  small  quantity  of  lead, 
or  other  metal,  deprives  it  of  this  characteristic  quality.  Tin  melts  at  442°  Fahr.,  and  is 
very  fixed  in  the  fire  at  higher  heats.  Its  specific  gravity  is  7*29.  When  heated 
to  redness  with  free  access  of  air,  it  absorbs  oxygen  with  rapidity,  and  changes 
first  into  a  pulverulent  gray  protoxyde,  and  by  lonsjer  ignition,  into  a  yellow-white 
powder,  called  putty  of  tin.  This  is  the  peroxyde,  consisting  of  100  of  metal  +  27-2 
of  oxygen.  ' 

Tin  has  been  known  from  the  most  remote  antiquity;  being  mentioned  in  the  books 
of  Moses.     The  Phoenicians  carried  on  a  lucrative  trade  in  it  with  Spain  and  Cornwall. 

There  are  only  two  ores  of  tin ;  the  peroxyde,  or  tin-stone,  and  tin  pyrites;  the 
^rmer  of  which  alone  has  been  found  in  sufficient  abundance  for  metallurgic  purposes. 
The  external  aspect  of  tin-stone  has  nothing  very  remarkable.  It  occurs  sometimes  in 
twin  crystals ;  its  lustre  is  adamantine ;  its  colors  are  very  various,  as  white  gray 
yellow,  red,  brown,  black;  specific  gravity  6-9  at  least;  which  is,  perhaps,  its  most 
striking  feature.  It  does  not  melt  by  itself  before  the  blowpipe;  but  is  reducible  in 
the  smoky  flame  or  on  charcoal.  It  is  insoluble  in  acids.  It  has  somewhat  of  a  ereasy 
aspect,  and  strikes  fire  with  steel. 

Tin-stone  occurs  disseminated  in  the  ancient  rocks,  particularly  granite ;  also  in  beds 
and  veins,  in  large  irregular  masses,  called  stockwerks ;  and  in  pebbles,  an  assemblage 
ot  which  IS  called  stream-works,  where  it  occasionally  takes  a  ligneous  aspect,  and  is 
termed  wood-tin,  *  o  r     > 

This  ore  has  been  found  in  few  countries  in  a  workable  quantity.  Its  principal  locali- 
ties are,  Cornwall  Bohemia,  Saxony,  in  Europe ;  and  Malacca  and  Banca,  in  Asia. 
Ihe  tin-mines  of  the  Malay  peninsula  lie  between  the  10th  and  6th  degree  of  south  lati- 
tude;  and  are  most  productive  in  the  island  of  Junck-Ceylon,  where  they  yield  sometimes 
aoo  tons  per  annum,  which  are  sold  at  the  rate  of  48/.  each.  The  ores  are  found  in  lar<-e 
caves  near  the  surface ;  and  though  actively  mined  for  many  centuries,  still  there  is  easy 
access  to  the  unexhausted  parts.  The  mines  in  the  island  of  Banca,  to  the  east  of 
Smatra  discovered  in  1710,  are  said  to  have  furnished,  in  some  years,  nearly  3500  tons 
of  tin.  Small  quantities  occur  in  Gallicia  in  Spain,  in  the  department  of  Haute  Vienne 
inlrance,  andin  the  mountain  chains  of  the  Fichtel  and  Riesen^eburge  in  Germany. 
The  columnar  pieces  of  pyramidal  tin-ore  from  Mexico  and  Chile,  are  products  of  stream- 
works.  Small  groups  of  black  twin  crystals  have  been  lately  discovered  in  the  albite  rock 
of  Chesterfield  in  Massachusetts. 

The  Cornish  ores  occur— 1  in  small  strata  or  veins,  or  in  masses ;  2.  in  stockwerks, 
or  congeries  of  small  veins ;   3.  m  large  veins ;   4.  disseminated  in  alluvial  deposites. 

The  stanniferous  small  veins,  or  thin  flat  masses,  though  of  small  extent,  are  somt- 
Umes  very  numerous,  mterposed  between  certain  rocks,  parallel  to  their  beds,  and  zte 
commonly  caUed  Un-floors.    The  same  name  is  occasionally  given  to  stockwerks.    In 


849 


Sh-tv  six  flthorit  b!^  fi  "f^,^^  .^"^"  ^^""^  '''  the  killas  (primitive  schistose  rock), 
Shi  .nnr-P  h  ,  ^""^  ^^'^  -^""^^  ""^  ^^^  ^^^  5  it  is  about  a  foot  and  a  half  thick,  and  occu' 
cinnexLn TeLeP^^^^^^^^  principal  vein  and  its  ramification ;  but  there  seems  to  be  no 
connexion  between  iha  Jloor  and  the  great  vein. 

•Z^tnThr^  .***'*'"*'  /"  ^'^"^^^  ^"^  '^  ^he  feldspar  porphyry,  called  in  ComwalJ. 
S^^ar%/!^.Lr'Tr''^^''°^'^'^^-^?  *^^  granite,  is  Vthe'lin-mine  of  Carcli^ 
t^^ni.J'fu  \-^-^^  ''''''■^^  ^^^  ^^^"^d  0"  i*!  the  open  air,  in  a  friable  granite,  con! 
Sinv  ?S'r  ^'''''''^'^'f  V"to  kaolin,  or  china  cla^  which  is  traversed^by  a%reat 
S/eadoni  InLT'^'f.fTl'^^^'''''^  ^'^^^^"^  ^"^  ^  ^^''^^  ^'^^-^tone,  that  form  black 
ra  dy  iceeds  fi  inlr  ""■  ^^e  light-gray  granite.  The  thickness  of  Ihese  little  veins 
mich  less  Sol  nrf^'  ^"'^^'^^^"-  ^he  adhering  solidified  granite,  and  is  occasionally 
mhcrs  with  fhP«J  H^°\'"''"1^''^  ^^?  ^"^  ^^'t'  '^''th  an  almost  vertical  dip; 
degrees.  direction,  incline  to  the  south  at  an  angle  with  the  horizon  of  70 

mJn!fn?''5^''''"^//*'''u'\f  J"^  ^'■^  '""*'''  "'"^^  frequent  in  tfieelvan  (porphyry),  of  which  the 
mine  of  Trewidden-ball  is  a  remarkable  example.     It  is  worked  among  flattened  masses 

anS^'STno?'  ''''''''  ^'^l^'  ^''^'  ''^  ''  ^^^  -st-north-east  V  a  consid^rS 
gkche/wh.Vh  Z  ^*^^""^^"  '""^^  ^^^"«'  7*^y»"?  i"  thickness  from  half  an  inch  to  8  or 
eitrtL^tect^VoT^^^^^^^^^  interrupted,  that  it  is  difficult  to  determine 

of  Co  Jn  w  Jl  17t"i?  ^'T'  P^talliferous  veins  are  not  equally  distributed  over  the  surface 
01  Cornwall  and  the  adjoining  part  of  Devonshire;   but  are  grouped  into  three  districts  • 
namely  1.  in  the  south-west  of  Cornwall,  beyond  Truro;   2.  inhHeic^h^^^^^^ 
St.  AusUe ;  and  3.  In  the  neighborhood  of  Tavistock  in  D^vonshL.       ""^'^^^'^"^  ^^ 

«hnn  JL  P-^  f-'"''^  •'  ^^-  ^^^  t^^  "*^^^'t,  and  the  best  explored.  The  formation  most 
abnndan  m  m  mines  is  principally  granitic;  whilst  tha  of  the  copper  iSnes  ?s  m^t 
fiequently  schistose  or  killas;  though  with  numerous  exceptions.  The  great  tiiv«^s 
are  the  mos  ancient  metalliferous  veins  in  Cornwall ;  yet  they  are  not  aU  orone  for^f 
buTi^rT  '"  T  ^"^^^?'  ^y^^^°^^-  Their  direction  is,  hUever,  nearly  the  s^e" 
ollr  tT  "^f.^^""  ^?  1°'^^'*^'  ^^^  "«^^^'  «"d  ^ll^ers  towards  the  south.  The  firstTe 
tip  on  ^V-  K  '!'^"^ '  [""'  ^"  ^"  '^^  °^*»^«  ^^^^^  t^^ese  two  sets  of  vein;  are  assodltS 

of  ^ip^'I?""^"*' •  mines,  the  two  systems  of  tin  veins  are  both  intersected  by  the  oldest 
of  the  copper  veins;   indicating  the  prior  existence  of  the  tin  veins.    In  )g!  1457 
' *^'  ^  marks  the  first  system  of  tin  veins ;  c,  the  second ; 

and  d,  the  east  and  west  copper  veins.  Some  of 
these  tin  veins,  as  at  Poldice,  have  been  traced 
over  an  extent  of  two  miles ;  and  they  vary  in 
thickness  from  a  small  fraction  of  an  inch  to 
several  feet,  the  average  width  being  from  2  to  4 
feet;  though  this  does  not  continue  uniform  for 
any  length,  as  these  veins  are  subject  to  continual 
narrowings  and  expansions.  The  gangue  is  quartz 
chlorite,  tourmaline,  and  sometimes  decomposed 
A     aij     •  1  ^'  .  granite  and  fluor  spar. 

trntpr  ?c  Z      •     •    1        *"*^  ^*-  ^^^^^^  5  w^ere  they  are  called  stream-works  •  because 
wat^er  IS  the  prmcipal  agent  employed  to  sepamte  the  metalUc  oxyde  froTthe'sand  and 

Dla^eVatini"?rnL^il"^/^'  in  Saxony  (fig.  1458,  which  is  a  vertical  projection  in  a 

tte  wortoea  zu,ater,or  ambiguou,.  In  ,620,  the  mini  w^wo  Jd  by  21  indSeS 
companies  in  a  most  irregular  manner,  whereby  it  was  damaged  toadepihof  170^^ 
hja  dreadful  downfall  of  the  roofs.  This  happened  on  a  Sunday,  providentially'wh^X 
pious  mmers  were  all  at  church.    The  depth  of  this  abyss,  mwked  by  the  cimTun. 


850 


TIN. 


ft,  I,  I,  is  66  fathoms ;  but  the  devastation  is  manifest  to  a  depth  of  95  fathoms  below  thai 

tJuyCy  and  35  fathoms  below  the  actual  workings,  represented  at  the  bottom  of  the  shaft 

under  b.  The  parts  excavated  are  shaded  black  in  the 
figure.  There  are  two  masses  of  ore,  one  under  the 
shaft  B,  and  another  under  the  shaft  c ;  which  at  the 
levels  5  and  10  are  in  communication,  but  not  at  6,  7. 
There  is  a  direct  descent  from  8  to  9.  The  deposites 
are  by  no  means  in  one  vertical  plane,  but  at  a  consider- 
able horizontal  distance  from  each  other,  a  is  the  de- 
scending shaft  ;  B  is  tlie  extraction  shaft,  near  the  mouth 
of  which  there  is  a  water-wheel;  c  is  another  extraction 
shaft,  worked  also  by  means  of  a  water-wheel,  a  and 
c  are  furnished  with  ladders,  but  for  b  the  ladders  are 
placed  in  an  accessory  shaft  b'  j  under  d  a  shaft  is  sunk 
for  pumping  out  the  water,  by  means  of  an  hydraulic 
wheel  at  D  ;  E  is  the  gallery  or  drift  for  admitting  the 
water  which  drives  the  wheels.  This  falls  300  feet,  and 
ought  to  be  applied  to  a  water-pressure  engine,  instead 
of  the  paddles  of  a  wheel.  At  d  is  the  gallery  of  dis- 
charge for  the  waters,  which  serves  also  to  ventilate  the 
mine,  being  cut  to  the  day,  through  936  toises  of  syenitic 
^  porphyry  and  gneiss.  J  is  a  great  vaulted  excavation. 
The  mine  has  13  stages  of  galleries,  of  which  11 
serve  for  extracting  the  ore;  1  is  the  mill-course;  the 
rest  are  marked  with  the  numbers  2,  3,  4,  &c. ;  each 
having  besides  a  characteristic  German  name.  The  rare 
mineral  called  topaz  pycnite  is  found  in  this  mine,  above 
10,  between  the  shafts  c  and  d. 

The  only  rule  observed  in  taking  ore  from  this 
mine  has  been  to  work  as  much  out  of  each  of  these 
levels  as  is  possible,  without  endangering  the  super- 
incumbent or  collateral  galleries;  on  which  account 
many  pillars  are  constructed  to  support  the  roofs.  The 
mine  yields  annually  1600  quintals  (Leipzick)  of  tin, 
being  four  fifths  of  the  whole  furnished  by  the  district 

of  Allenberg ;   to  produce  which,  400,000  quintals  of  ore  are  raised.      1000  parts  of 

the  rock  yield  8  of  concentrated  schlich,  equivalent  to  only  4  of  metal ;  being  only  1  in 

250  parts. 

Bnt  the  most  extensive  and  productive  stream-works  are  those  of  Pentowan,  near 

St.  Austle. 
Fig.  1459  represents  a  vertical  section  of  the  Pentowan  mine,  taken  from  the 

stream-uo)kf  Happy  Union.    A  vast  excavation,  r,  t,  u,  »,  has  been  hollowed  out  in 


TIN. 


851 


1459 


the  open  air,  in  quest  of  the  alluvial  tin 
ore,  T,  which  occurs  here  at  an  unusual 
depth,  below  the  level  of  the  strata  r,  s. 
Before  getting  at  this  deposite,  several 
successive  layers  had  to  be  sunk  through  j 
namely,  1,  2,  3 ;  the  gravel,  containing  in 
its  middle  a  band  of  ochreous  earth  2,  or 
ferruginous  clay ;  4,  a  black  peat,  per- 
fectly combustible,  of  a  coarse  texture, 
composed  of  reeds  and  woody  fibres,  ce- 
mented into  a  mass  by  a  fine  loam ;  5, 
coarse  sea-sand,  mingled  with  marine  shells ; 
6,  a  blackish  marine  mud,  filled  with  shells.  Below  these  the  deposite  of  tin-stone  occurs, 
including  fragments  of  various  size,  of  clay  slate,  flinty  slate,  quartz,  iron  ore,  jasper ; 
in  a  word,  of  all  the  rocks  and  gangues  to  be  met  with  in  the  surrounding  territory,  with 
the  exception  of  granite.  Among  these  fragments  there  occur,  in  rounded  particles,  » 
coarse  quartzose  sand,  and  the  tin-stone,  commonly  in  smal  grains  and  crystals.  Beneath 
the  bed  t,  the  clay  slate  occurs,  called  killas,  (a,  x,  y,)  which  supports  all  the  depositee 
of  more  recent  formation. 

The  systeii  of  mining  is  very  simple.  The  successive  beds,  whose  thickness  is  shown 
in  the  figure,  are  visibly  cut  out  into  steps  or  platforms.  By  a  level  or  gallery  of  efflux, 
fc,  the  waters  flow  into  the  bottom  of  the  well  Z,  m,  which  contains  the  drainage  pumps; 
•nd  these  are  put  in  action  by  a  machine, ;,  moved  by  a  water-wheel.  The  extraction  c/ 
the  ore  is  effected  by  an  inclined  plane,  i,  cut  out  of  one  of  the  sides  of  the  excavation, 
at  an  angle  of  about  45  degrees.    At  the  lower  end  of  this  sloping  pathway  there  is  a 


fht^Vo^wul? '  ^''i^^  '^.'  "PP^'  ^"^  ^^  ^  horse-gm,  for  alternately  raising  and  lowenng 
the  two  baskets  of  extraction  on  the  pathway  t.  g«u«iuwcnng 

^^nt"lAl  '"^^'"'"^^  P^^."li*'  ''"^  '"  *^s  mechanical  preparation  or  dressing,  on  ac 
hft  ^''''"''  '^  ^"''^^"  °^^^^'  ^^""  '^^'^>  ^'  ^^  h»^«  stated,  the  s^ieam  tS 

niniVk^  the  mine  tin  is  for  the  most  part  extremely  dispersed  through  the  ganffue  it 

IZ^LT^ICLt^^^Z^  ^"^  «"^  ^^'"' '"  -'-  "•«  -WicXS'  i' 

is  lesAnt"!^  ™f^!r  ■°^'i°"°T''  """^.  «"*'"  """>  *■>«'  <"■  ■»««»  o'her  metallic  ores,  it 

^^'in^ytzn^^a^s^"''''''  "^ '''-'''  -  -^ '°  •«  -""^'-'^ 

^  3.  As  the  peroxyde  of  tin  is  not  afifected  by  a  moderate  heat  it  mav  be  exno^nl  tn  p«1 

We  may  therefore  conclude,  that  tin  ore  should  be  first  of  all  pounded  verv  fine  in  the 

foil:  ^^''''''''S  the  ore.— This  is  usually  done  at  the  mouth  of  the  gallery  of  efflux  bv  a-i- 

r;i*  f''''l}''S---The  ore  thus  cleaned,  is  sorted  on  the  grate,  into  four  heaps  :  1.  stones 
rich  m  tin;  2.  s  ones  containing  both  tin  and  copper  ore;  3.  copper  ore-  4  senile 
pieces,  composed  ma  great  measure  of  stony  gangue  with  iroi  and  arsenical  pyrites  la 
WheVresen^Thp'r  ^'  ^^^^PP- ^^  t|ie  seco^kd  'and  third  heaps  are  obvtuTaLnu 
fra^m^en^are'^orte'drer  "'  "  '"'^"  "^^  ^"^"^^  ^'^^^^  "^^^  ^  -'^^^^^  -^  the 
3.  Stumping.— The  stanniferous  fragments  (No.  1)  are  stamped  into  a  sand  of  greater 
or  less  fineness,  according  to  the  dissemination  of  the  tin-stone  in  he  gan^c  TheT- 
termination  of  the  size  of  the  sand  is  an  object  of  great  importance  ItTreVulafed  bv 
a  copper  plate  pierced  with  small  holes,  through  which  every  thing  from  the  s^a^nin/ 

Several  years  ago,  all  the  stamp-mills  were  driven  by  water-wheels  which  limited  the 
quantity  of  ore  that  could  be  worked  to  the  hydraulic  power  of  iKre^m  or  water^^^^^^ 
but  since  the  steam  engine  has  been  applied  to  this  purpose,  thrLnualpr^rt  of  tii 
has  been  greatly  increased.     On  the  mine  of  Huel  Vor,  there  are  "hree  ste^  eneinS 
appropriated  to  the  stamping-mills.     Their  force  is  25  horses  at  least?    O^of  Sese 

llLrJni  •  \  The  weight  of  these  pestles  varies  from  370  to  387  pounds ;  and  they 
generally  rise  through  a  space  of  10|  inches.  The  machine  called  south  stamvs  thl 
strongest  of  the  three,  gives  I7|  blows  in  the  minute,  each  pestle  beinrMedtTc;  ^^^^^ 
ft^'nL'''"'''il?'K  ^'fT-  r  '^^^  '"'^"^  '^^^^'  «^  this  ^iU  has  a  power  Sf  25  hordes  and 
itamp-rx!"  "^"^"  "^  '°"^'  ^"  '^'  °^"'^'^-    T^^^^  P^^^^^  Constitute  a  Se^,  or 

Washing  and  stamping  0/ tin  ores  at  Polgooth,  near  St.  jSustle.-The  stamps  or  pesUes 
1460        1.^5  "'"''^^  ^  '''''^J  ^y  ^^  i"  the  square :  they  carry  lifting  bars  6,  secured 

iTmn^nr"^'"  "^'^^^  ,?.^  "  ^'^'  "^  ^^«">  «"d  ^^cy  terminate  belowTa 
lump  of  cast  iron  a,  called  the  head,  which  is  fastened  to  them  by  a  taU 
and  weighs  about  2|  cwts  The  shank  of  the  pestle  is  strengthened  wiTh 
ZJrT.',  '^  ^F"^"&/S^^ft  communicates  motion  to  the  stamps  by  cams 
stuck  round  its  circumference,  so  arranged  that  the  second  falls  while  the 
fin  r^  'i^'n  ^^r^V^'  are  uplifted.  There  are  4  cams  on  one  p^riphei;! 
and  the  shaft  makes  7  turns  in  the  minute.  Each  stamp,  therefore,  givTs 
lle^ttZr\TT  «»\f^"V^ro«gh  a  space  of  7i  inches.  The  sfiLp 
chest  s  open  behind    so  that  the  ore  slips  away  under  the  pestles,  by  its 

trti^"^  '^-  r^r^  ^^^T  ^^^^  '^^  ^^^^^  «f  ^^ter.     The  Wtom  ol 

I 1 Pnii-  ^     ^TT  u^  '^'"P^^  °'*^^-   With  6  batteries  of  6  pesUes  each,  at 

A  P«W»ce,  near  Redruth,  120  bags  of  ore  are  stamped  in  12  hours ;  each  bag 

' '    feTaTl6fcfbi;rrher  ^"^  measuring  altogethe;  352  cubil 

The  openings  in  the  front  sides  of  the  troughs  are  neariv  ei«»ht  inches  hv  rpvph  nnrl  . 
S  ^^^y.^f  "^^  ^^^^  ^l  T'^  f--e,  which  b  closed  wih  sK  i  ^nS^  w' th  al^ut 
dels  Jlc'^rf  ^''^r '>  ^T^-  '""^'.^'.'5^'  ^^^"S  "*"«^«^  ^'thin.  The  ore7«  issuing 
wS  •  I  ^^^ V"  ^^/  ^''^  ^^'"1'  ^"^  '^^  ^^^^^«  i«  the  following  basins.  The  rough  S 
n  k?n!?  ^''  f 'm  ^'^^;  P/^'  f  ^^;  *"^  ^"  tossing.tubs ;  the  slimes  in  tru'nks,  and  n? 
on  a  kind  of  twin  tables,  called  racks.  Into  the  tossing4ub,  or  dolly,  fig.  1461,  the  stamS 
ed  ore  is  thrown,  along  with  a  certain  quantity  of  water,  'and  a  worLan  s ti«  it  SSJl 


\l 


852 


TIN. 


I 


^^W^^^^^^5^^»^m^WM?5^^^ 


"With  an  iron  shovel  for  three  or  four  minutes.    He  then  removes  a  little  of  the  water 

with  a  handled  pitcher,  and  strikes  the  sides  of  the  tub  for  8  or  10  minutes  with  a  hammer, 

which  hastens  the  subsidence  of  the  denser  parts.    The  water 

is  next  poured  off  by  inclining  the  tub  to  one  side.    In  one 

operation  of  this  kind,  four  distinct  strata  of  the  ores  may  be 

procured,  as  indicated  by  the  lines  a  b,  c  d,  e  f  g,hiky  in 

the  figure.     The  portion  b  is  to  be  washed  again  in  the 

trunking^x,  figs.  1462,  1463 ;  b  is  to  be  washed  upon  the 

German  chests  or  racks,  fig,  1464  ;  c,  the  most  considerable, 

js  put  aside,  as  schlich  fit  for  the  market ;  d,  forming  a  nucleus 

in  the  centre  of  the  tub,  is  to  be  passed  through  sieves  of 

copper  wire,  having   18  meshes  in  the  square  inch.    This 

,    „     , .  .  .    Prtxluct  thus  affords  a  portion  D',  which  passes  through  the 

sieve,  and  d    which  remams  upon  it ;  the  latter  is  sometimes  thrown  away,  and  at  others  is 

loniTrou-h"         °P^''***®"  ""^^^^  the  He,  viz.,  a  washing  upon  the  sloping  bottom  of  a 

The  slimes  are  freed  from  the  lighter  mud  in  the  tiunking-box,  /iff*.  1462,1463: 
which  IS  from  7  to  8  feet  long.    Being  accumulated  at  m,  the  workmf  n  pushes  them 

_^  ^     back  with  a  shovel  from  a  towards  b. 
The  metallic  portion  is  carried  off,  and 
deposited  by  the  stream  of  water  upon 
the  table ;  but  the  earthy  matters  are 
floated  along  into  a  basin  beyond  it. 
The  product  collected  in  the  chest  is  di- 
vided into  two  portions;  the  one  of 
which  is  washed  once,  and  the  other 
twice,  upon  the  rack,  fig.  1464.    Thii 
is  composed  of  a  frame  c,  which  carries 
a  sloping  board  or  table,  susceptible  of 
turning  round  to  the  right  or  left  upon 
two  pivots,  K,  K.    The  head  of  the 
table  is  the  inclined  plane  t.    A  small 

^P  .    ,,  - ,,.,„,...  board  p,  which  is  attached  by  a  band 

01  leather  l,  forms  the  communication  with  the  lower  table  c,  whose  slope  is  generally 
5  inches  m  its  whole  length  of  9  feet;  but  this  may  vary  with  the  natire  of  the  ore, 
bemg  somewhat  less  when  it  is  finely  pulverized.    The  ore  is  thrown  upon  t,  in  small 

portions  of  20  or 
25  lbs.  A  woman 
spreads  it  with 
a  rake,  while  a 
stream  of  water 
sweeps  a  part  of 
it  upon  the  table, 
where  it  gets 
washed.  The  fine 
mud  falls  through 
a  cross  slit  near 
the      lower     end. 

After  working  for  a  few  minutP*!  «wi7T>I     ZTT  "^^^^^    ^^^^    ^    ^^^^^    ^* 

turns  the  t^hle  ronldTs  ^Tltl^tnf  ''k''^.  '"""^  1°^"'^"^  ""^'  ^^^  ^P^^^^ive 
is  in  B ;  an  impure  schich^n  ^'\^  S  ^"^^^^  ''  '"^°  '^^  ^^^^^^  ^e^«^-  The  mud 
schlich  fit  for  rSing  in  B-       '  "'''''  ^^  ""^^^"^  *^*^  "P°"  *^^  ^""'^ '  ^""^^ 

^Jhe  slope  of  the  raVtabie  for  washing  the  roasted  tin  ore,  is  Tf  inches  in  the  nine 

rop'eT^iS'ir^r^e'  to\f  SStd'^;^^^^^^^  ''T'  ^'^  ^  ^^-^  ^^  -  -'^^-^ 
A  trap  bling  opened  in  t^e  sMe  of T.  -  l'^^  T'  ^^^^^'^^^  «^«^^  in  ;?g.  1465. 
It  passes  directly  between  thPtJn  ^^,.^*S°'^'  ^he  ore  falls  into  the  hopper  t,  whence 
receives  a  see  L  mot?on  h^^^^^^  "^^^  ^P<>^  '^^  sieve  i,  which 


TIN. 


853 


receives  a  seesaw  motion  hnr.Vnn7oiT;,T  '    '  r* ,  "^^'  "P®^  '^®  sieve  d,  which 

upright  turning-shar  Ve  fine/  .S^.^^  °lf^^  «^  i^«  '^  ^>  ^nd  the  crank  of  the 
forms  the  heap  8.    tL  coarser^^^^^^  ""^^"^^  P«^^^«  ^^^^^^  that  sieve, 

between  the  cyuJrT ^T^Zo^TZ:"  llvef  anT/  *'^  t^''  °'  ^^A^^^^^'  ^^^  '^ 
and  s"  of  unsifted,  ore        '    ^""  *  ^^^^r  level,  and  forms  the  second  heap  s'  of  sifted, 

fin^e'ss'.°'?4^S^^  rr^^>  ''^  p'^r  ^^^^  -^  °^^^^  »- 

limps  from  the  wagons.  '  ^  ^^  uppermost  hopper  t,  along  with  tht 


The  diameter  and  length  of  the  under  rolls  (see  fig.  1466)  are  each  16  incnca. 

•  6,  is  the  square  end  of  the  gudgeon  t,  which  prevents  the  shaft  shifting  laterally  on 

of  its  place.  The  di- 
ameter of  the  upper 
rolls  is  18  inches,  but 
their  length  is  the 
same.  Both  are  made 
of  white  cast  iron, 
chilled  or  case-harden- 
ed by  being  cast  in 
iron  moulds  instead  of 
sand;  and  they  last  a 
month,  at  least,  when 
of  good  quality.  They 
make  from  10  to  15 
turns  in  a  minute,  ac- 
cording to  the  hard- 
ness of  the  ores  of  tin 
or   copper;    and    can 

grind  about  50  tons  of  rich  copper  ore  in  12  hours ;  but  less  of  the  poorer  sort. 

*  The  next  process  is  the  calcination  in  the  burning-house;  which   includes 


1466 


several 
reverberatory  furnaces.  At  the  mine  of  Poldice,  they  are  4  or 
5  yards  long,  by  from  2§  to  3  yards  wide.  Their  hearth  is  hori- 
zontal ;  the  elevation,  about  26  inches  high  near  the  fireplace, 
sinks  slightly  towards  the  chimney.  There  is  but  one  opening, 
which  is  in  the  front;  it  is  closed  by  a  plate-iron  door,  turning 
on  hinges.  Above  the  door  there  is  a  chimney,  to  let  the  sulphurous  and  arsenical 
vapors  fly  off,  which  escape  out  of  the  hearth,  without  annoying  the  workmen.  This 
chimney  leads  to  horizontal  flues,  in  which  the  arsenious  acid  is  condensed. 

Six  hundred  weights  of  ore  are  introduced;  the  calcination  of  which  takes  from  12  to 
18  hours,  according  to  the  quantity  of  pyrites  contained  in  the  ore.  At  the  beginning 
of  the  operation,  a  moderate  heat  is  applied ;  after  which  it  is  pushed  to  a  dull  red,  and 
kept  so  during  several  hours.  The  door  is  shut ;  the  materials  are  stirred  from  time  to 
time  with  an  iron  rake,  to  expose  new  surfaces,  and  prevent  them  from  agglutinating  or 
kerning,  as  the  workmen  say.  The  more  pyrites  is  present,  the  more  turning  is  neces- 
sary. Should  the  ore  contain  black  oxyde  of  iron,  it  becomes  peroxydized,  and  is  then 
easily  removed  by  a  subsequent  washing. 

Figs.  1467,  1468  represent  the  furnace  employed  at  Altenberg,  in  Saxony,  for  roasting 
tin  ores,    a  is  the  grate ;  b,  the  sole  of  the  roasting  hearth ;  c,  an  opening  in  the  arched 


1467 


roof  for  introducing  the  dried  schlich  (the  ground 
and  elutriated  ore) ;  d,  is  the  smoke-mantle  or 
chimney-hood,  at  the  end  of  the  furnace,  under 
which  the  workmen  turn  over  the  spread  schlich, 
with  long  iron  rods  bent  at  their  ends  ;  e,  is  the 
poison  vent,  which  conducts  the  arsenical  vapors 
to  the  poison  chamber  (gifthaus)  of  condensa- 
tion. 

When  the  ore  is  sufllciently  calcined,  as  is 
shown  by  its  ceasing  to  exhale  vapors,  it  is 
taken  out,  and  exposed  for  some  days  to  the 
action  of  the  air,  which  decomposes  the  sul- 
phurets,  or  changes  them  into  sulphates.  The 
ore  is  next  put  into  a  tub  filled  with  water, 
stirred  up  with  a  wooden  rake,  and  left  to  settle ; 
by  which  means  the  sulphate  of  copper  that  may 
have  been  formed,  is  dissolved  out.  After  some 
time,  this  water  is  drawn  off  into  a  large  tank, 
and  its  copper  recovered  by  precipitation  with 
pieces  of  old  iron.  In  this  way,  almost  all  the 
copper  contained  in  the  tin  ore  is  extracted. 
The  calcined  ore  is  sifted,  and  treated  again  on  the  racks,  as  above  described. 
The  pure  schlich,  called  black  tin,  is  sold  under  this  name  to  the  smelters ;  and  that 
which  collects  on  the  middle  part  of  the  inclined  wash-tables,  being  much  mixed  with 
wolfram,  is  caJled  mock  lead.  This  is  passed  once  more  through  the  stamps,  and  washed; 
when  it  also  is  sold  as  bla^k  tin. 

Stream  tin  is  dressed  by  similar  methods;  1.  by  washing  in  a  trunking-box,  of  such 
iimensions  that  the  workman  stands  upon  it  in  thick  boots,  and  makes  a  skilful  ust 


■■ai 


854 


TIN. 


TIN. 


855 


'l!il 


>f  the  rake;  2,  by  separating  the  larger  conglomerate  pebbles  from  the  smaller  pure 
jig? 910^1  if  '^^""P'"^'  ^""^  washing,  on  a  kind  of  sleeping-table, .    See  Metallurgy, 

thI^"jL-^lS'  ^^^°',^^^"  and  Devonshire  are  all  reduced  within  the  counties  where 
fer  nn?nJnrvf '  tv^  laws  prohibit  Uieir  exportation  out  of  them.  Private  interests  suf- 
ter  no  injury  from  this  prohibition ;  because  the  vessels  which  bring  the  fuel  from  Wales, 
for  smelting  these  or«,  return  to  Swansea  and  Neath  loaded  with  copper  ores 

The  smelting-works  belong  in  general  to  individuals  who  possess  "no  tin  mines,  but 
who  purchase  at  the  cheapest  rate  the  ores  from  the  mining  proprietors.    Th7  ores  are 

S'rn/h'Th^'?^/" '^'^' ^r^";^  ^^  "^''^^^  ^"^  '''  fineness?  condition  whrchth^y 
determine  by  the  following  mode  of  assay  :-When  a  certain  number  of  bags  of  ore,  of 
nearly  the  same  quality,  are  brought  to  the  works,  a  small  sample  is  taken  frSm  each  bae 

four  n'pr^^pt  '7  """^  ^i'^^l*  ^^-^  """^^^  °^  ^^'^  average  ore  are  mixed  wifhaboS 
fnrn  J  V  P""*^  ^''.^^'  P"*  ^''^'^  *"  **P^"  ^^'"^^^^  cfucible,  and  heated  in  an  air 

verv  hn/whpTK  *^"^A^^ mches  square)  till  reduction  takes  place.  As  the  furnace  is 
W     t11    ftr''^^''':i".''^'^'^^^  «"'^^^J  i"  about  a  quarte,  of  an 

o  }a-  ^^*^  ^^"^  ^^^'^^^  *^  P®"*"^  *"*o  *  "^ould,  and  what  remains  in  the  crucible 

IS  pounded  m  a  mortar,  that  the  grains  of  tin  may  be  added  to  the  in^ot. 

T.ni  oo™f  ^^  'i^u""^  imperfect  in  a  chemical  point  of  view,  serves  the  smelter's  pur- 
pose, as  It  affords  him  a  similar  result  to  what  he  would  get  on  the  sreat  scale     A  more 

thplT'  r"^. '/  '^^'^"'^  ^y  !:"^^"-  ^"  ^  ""^'We  lined  with  hard  rammS  charToal! 
the  ore  mixed  with  five  per  cent,  of  ground  glass  of  borax.     To  the  crucible  a  gentle  hea 
hould  be  applied  during  the  first  hour,  then  a  strong  heat  during  the  second  hour!  and 
lastly,  an  intense  heat  for  a  quarter  of  an  hour.   This  process  brings  out  from  four  o  five 
per  cent,  more  tm  than  the  other ;  but  it  has  the  inconvenience  of  reducing  the  iron  should 
asTavT«l!f  ho  t^n  !'^^^  subsequent  solution  in  nitrie  acid  will  be  readily  shown.    This 

saSpkTi^  one  day.  ''  "^^  ^^'''  ^'''^'^^  '"^  '"^  ^  ^'"^^  "^^"^ 

The  smelting  of  tin  ores  is  effected  by  two  difi*erent  methods  — 

In  the  first,  a  mixture  of  the  ore  with  charcoal  is  exposed  to  heat  on  the  hearth  of  a 
reverberatory  furnace  fired  with  coal.  °'  * 

In  the  second,  the  tin  ore  is  fused  in  a  blast  furnace,  called  a  blowin^-house  sunnlied 
with  wood  charcoal  This  method  is  practised  in  onl/a  few  works,  in  order  to  obtSI 
very  pure  quality  of  tin,  called  grain  tin  in  England  and  etain  en'/armS?n  France  a 
metal  required  for  certain  arts,  as  dyeing.  Sec,    This  method  is  applied  merely  to  stream 

In  the  smelting-hmses,  where  the  tin  is  worked  in  reverberatories,  two  kinds  of  furna 
ces  are  employed ;  the  reduction  and  the  refining  furnaces. 
Figs.  1469,  1470,  represent  the  furnaces  for  smelting  tin  at  St.  Austle,  in  Cornwall; 

the  former  being  a  longitudinal  section! 


the  latter  a  ground  plan,    a,  is  the  fire- 
door,  through  which  pitcoal  is  laid  upon 
the  grate  6;  c,  is  the  fire-bridge;  <f,  the 
door  for  introducing  the  ore ;  e,  the  door 
through  which  the  ore  is  worked  upon 
the  hearth  /;  g,  the  stoke-hole ;  A,  an 
aperture  in  the  vault  or  roof,  which  is 
opened  at  the  discharge  of  the  waste 
schlich,  to  secure  the  frte  escape  of  the 
fumes  up  the  chimney ;  t,  i,  air  channels 
for  admitting  cold  air  under  the  fire- 
bridge and  the  sole  of  the  hearth,  with 
the  view  of  protecting  them  from  injury 
by  the  intensity  of  the  heat  above,   fc,  Ar, 
are  basins  into  which  the  melted  tin  is 
drawn  oflT;  Z,  the  flue ;  m,  the  chimney, 
from  35  to  50  feet  high.    The  roasted 
and  washed  schlich  is  mixed  with  small 
coal  or  culm,  along  with  a  little  slaked 
lime,  or  fluor  spar,   as   a  flux;    each 
charge  of  ore  amounts  to  from  15  to  24 
cwts.,  and  contains  from  60  to  70  pei 
cent,  of  metal. 

Fig.  1471  represents  in  a  vertical  sec 
tion  throush  the  tuyere,  and  j?g.  1472,  in 
a  horizontal  section,  in  the  dotted  line  a:, 
^i  ^^  fiS-  1471,  the  furnace  employed 


1470 


1471 


fcr  smelling  tin  at  the  Erzegebirge  mines,  in  Saxony,    a,  are  the  furnace  pillars,  ol 
jmeiss ;  by  b,  are  shrouding  or  casing  walls ;  c,  the  tuyere  wall ;  d,  front  wall,  both  of 

granite;  as  also  the  tuyere  e.  /,  the  sole-stone,  of  granite,  hewn 
out  basin-shaped ;  g,  the  eye,  through  which  the  tin  and  slag 
are  drawn  off  into  the  fore-hearth  h)  t,  the  stoke-hearth  ;  fc, .%, 
the  light  ash  chambers ;  /,  the  arch  of  the  tuyere ;  «i,  wi,  the 
common  flue,  which  is  placed  under  the  furnace  and  the  hearths, 
and  has  its  outlet  under  the  vault  of  the  tuyere. 

In  the  smelting  furnaces  at  Geyer,  the  following  dimensions 
are  preferred :— Length  of  the  tuyere  wall,  11  inches;  of  the 
breast  wall,  11  inches;  depth  of  the  furnace,  17  inches.     High 
chimney-stalks  are  advantageous  where  a  great  quantity  of  ores 
is  to  be  reduced,  but  not  otherwise. 
The  refining  furnaces  are  similar  to  those  which  serve  for  re- 
ducing the  ore ;  only,  instead  of  a 
1472  basin  of  reception,  they  have  a 

refining  basin  placed  alongside, 
into  which  the  tin  is  run.  This 
basin  is  about  four  feet  in  diame- 
ter, and  thirty-two  inches  deep; 
it  consists  of  an  iron  pan,  placed 
over  a  grate,  in  which  a  fire  may 
be  kindled.  Above  this  pan  there 
is  a  turning  gib,  by  means  of  which 
a  billet  of  wood  may  be  thrust 
down  into  the  bath  of  metal,  and 
kept  there  by  wheeling  the  gibbet 
over  it,  lowering  a  rod,  and  fixing  it  in  that  position. 

The  works  in  which  the  blast  furnaces  are  employed,  are  called  blowing-hmLses.  The 
smelting  furnaces  are  six  feet  high,  from  the  bottom  of  the  crucible  (concavf  hearth)  to 
the  throat,  which  is  placed  at  the  origin  of  a  long  and  narrow  chimney,  interrupted  by  a 
chamber,  where  the  metallic  dust,  carried  off  by  the  blast,  is  deposited.  This  chamber 
is  not  placed  vertically  over  the  furnace ;  but  the  lower  portion  of  the  chimney  has  an 
oblique  direction  from  it.  The  furnace  is  lined  with  an  upright  cylinder  of  cast  iron, 
coated  internally  with  loam,  with  an  opening  in  it  for  the  blast.  This  opening,  which 
corresponds  to  the  lateral  face  opposite  to  the  charging  side,  receives  a  tuyere,  in  which 
the  nozzles  of  two  cylinder  single  bellows,  driven  by  a  water-wheel,  are  planted.  The 
tuyere  opens  at  a  small  height  above  the  sole  of  the  furnace.  On  a  level  with  the  sole, 
the  iron  cylinder  presents  a  slope,  below  which  is  the  hemispherical  basin  of  reception, 
set  partly  beneath  the  interior  space  of  the  furnace,  and  partly  without.  Near  the  corner 
of  the  building  there  is  a  second  basin  of  reception,  larger  than  the  first,  which  can  dis- 
charge itself  into  the  former  by  a  sloping  gutter.  Near  this  basin  there  is  another,  for 
the  refining  operation.    These  are  all  made  either  of  brick  or  cast  iron. 

The  quality  of  the  average  ground-tin  ore  prepared  for  smelting  is  such,  that  20  parts 
of  it  yield  from  12|  to  13  of  metallic  tin,  (62|  to  65  per  cent.)  The  treatment  consists 
of  two  operations,  smelting  and  refining. 

First  0}ieratim;  deoxydization  of  the  ore  and  fusion  of  the  fin.— -Before  throwing  the 
ore  into  the  smelting  furnace,  it  is  mixed  with  from  one  fifth  to  one  eighth  of  its  wei^'ht 
o^ blind  coal,  in  powder,  called  culm;  and  a  little  slaked  lime  is  sometimes  added,  to  ren- 
der  the  ore  more  fusible.  These  matters  are  carefully  blended,  and  damped  with  water 
to  render  the  charging  easier,  and  to  prevent  the  blast  from  sweeping  any  of  it  away  at 
tlie  commencement.  From  12  to  16  cwts.  are  introduced  at  a  charge ;  and  the  doors  are 
immediately  closed  and  luted,  while  the  heat  is  progressively  raised.  AVere  the  fire  too 
strong  at  first,  the  tin  oxyde  would  unite  with  the  quartz  of  the  gan?ue,  and  form  an 
enamel.  The  heat  is  applied  for  6  or  8  hours,  during  which  the  doors  are  not  opened  • 
of  course  the  materials  are  not  stirred.  By  this  time  the  reduction  is,  in  general,  finish- 
ed; the  door  of  the  furnace  is  removed,  and  the  melted  mass  is  worked  up  to  complete 
the  separation  of  the  tm  from  the  scoriae,  and  to  ascertain  if  the  operation  be  in  sufiicient 
forwardness.  When  the  reduction  seems  to  be  finished,  the  scorice  are  taken  out  at  the 
same  door,  with  an  iron  rake,  and  divided  into  three  sorts;  those  of  the  first  class  A, 
which  constitute  at  least  three  fourths  of  the  whole,  are  as  poor  as  possible,  and  may  be 
thrown  away;  the  scoriae  of  the  second  class  b,  which  contain  some  small  grains  of  tin, 
are  sent  to  the  stamps;  those  of  the  third  class  c,  which  are  last  removed  from  the  sur- 
face of  the  bath  of  tin,  are  set  apart,  and  re-smelted,  as  containing  a  considerable  quan- 
Uty  of  metal  m  the  form  of  grain  tin.  These  scoriae  are  in  small  quantity.  The  stamo 
slag  contains  fully  five  per  cent,  of  metallic  tin. 
As  soon  as  the  scoriae  are  cleared  away,  the  channel  is  opened  which  leads  to  the 


oOv 


Tm. 


TIN. 


I  1 


3 


basin  of  reception,  into  which  the  tin  consequently  flows  out.  Here  it  is  left  for  somo 
lime,  that  the  scoriae  which  may  be  still  mixed  with  the  metal,  may  separate,  in  virtue 
of  the  difference  of  their  specific  gravities.  When  the  tin  has  sufficiently  settled,  it  is 
lifted  out  with  ladles,  and  poured  into  cast-iron  moulds,,  in  each  of  which  a  bit  of  wood  is 
fixed,  to  form  a  hole  in  the  ingot,  for  the  purpose  of  drawing  it  out  when  it  becomes  cold. 

Refining  of  tin. — The  object  of  this  operation  is  to  separate  from  the  tin,  as  completely 
as  possible,  the  metals  reduced  and  alloyed  along  with  it.  These  are,  principally,  iron, 
copper,  arsenic,  and  tungsten ;  to  which  are  joined,  in  small  quantities,  some  sulphurets 
and  arseniurets  that  have  escaped  decomposition,  a  little  unreduced  oxyde  of  tin,  and  also 
some  earthy  matters  which  have  not  passed  off  with  the  scoriae. 

Liquation.— -TYie  refining  of  tin  consists  of  two  operations ;  the  first  being  a  liquation, 
which,  ia  the  interior,  is  efi'ected  in  a  reverberatory  furnace,  similar  to  that  employed  in 
smelting  the  ore,  {figs.  1469,  1470.)  The  blocks  being  arranged  on  the  hearth  of  the 
furnace,  near  the  bridge,  are  moderately  heated ;  the  tin  melts,  and  flows  away  into  the 
refining-basin  j  but,  after  a  certain  time,  the  blocks  cease  to  aflbrd  tin,  and  leave  on  the 
hearth  a  residuum,  consisting  of  a  very  ferruginous  alloy. 

Fresh  tin  blocks  are  now  arranged  on  the  remains  of  the  first ;  and  thus  the  liquation 
is  continued  till  the  refining-basin  be  sufficiently  full,  when  it  contains  about  five  tons. 
The  residuums  are  set  aside,  to  be  treated  as  shall  be  presently  pointed  out. 

Refining  proi>er. — Now  begins  the  second  part  of  the  process.  Into  the  tin-bath, 
billets  of  green  wood  are  plunged,  by  aid  of  the  gibbet  above  described.  The  dis 
engagement  of  gas  from  the  green  wood  produces  a  constant  ebullition  in  the  tin : 
bringing  up  to  its  surface  a  species  of  froth,  and  causing  the  impurest  and  densest 
parts  to  fall  to  the  bottom.  That  froth,  composed  almost  wholly  of  the  oxydes  of 
tin  and  foreign  metals,  is  successively  skimmed  oft',  and  thrown  back  into  the  furnace. 
When  it  is  judged  that  the  tin  has  boiled  long  enough,  the  green  wood  is  lifted  out,  and 
the  bath  is  allowed  to  settle.  It  separates  into  diflerent  zones,  the  upper  being  the 
purest ;  those  of  the  middle  are  charged  with  a  little  of  the  foreign  metals ;  and  the 
lower  are  much  contaminated  with  them.  When  the  tin  begins  to  cool,  and  when  a 
more  complete  separation  of  its  diflerent  qualities  cannot  be  looked  for,  it  is  lifted  out  in 
ladles,  and  poured  into  cast-iron  moulds.  It  is  obvious,  that  the  order  in  which  the  suc- 
cessive blocks  are  obtained,  is  that  of  their  purity ;  those  formed  from  the  bottom  of  the 
basin  being  usually  so  impure,  that  they  must  be  subjected  anew  to  the  refining  process, 
as  if  they  had  been  directly  smelted  from  the  ore. 

The  refining  operation  lakes  5  or  6  hours ;  namely,  an  hour  to  fill  the  basin,  three  hours 
to  boil  the  tin  with  the  green  wood,  and  from  one  to  two  hours  for  the  subsidence. 

Sometimes  a  simpler  operation,  called  tossing^  is  substituted  for  the  above  artificial 
ebullition.  To  eflect  it,  a  workman  lifts  some  tin  in  a  ladle,  and  lets  it  fall  back  into 
the  boiler,  from  a  considerable  height,  so  as  to  agitate  the  whole  mass.  He  continues 
this  manipulation  for  a  certain  time ;  after  which,  he  skims  with  care  the  surface  of 
the  bath.  The  tin  is  afterwards  poured  into  moulds,  unless  it  be  still  impure.  In  this 
case,  the  separation  of  the  metals  is  completed  by  keeping  the  tin  in  a  fused  state  in  the 
boiler  for  a  certain  period,  without  agitation  ;  whereby  the  upper  portion  of  the  bath  (at 
least  one  halO  is  pure  enough  for  the  market. 

The  moulds  into  which  the  tin  blocks  are  cast,  are  usually  made  of  granite.  Their 
capacity  is  such,  that  each  block  shall  weigh  a  little  more  than  three  hundred  weights. 
This  metal  is  called  block  tin.  The  law  requires  them  to  be  stamped  or  coined  by  public 
officers,  before  being  exposed  to  sale.  .  The  purest  block  tin  is  called  refined  tin. 

The  treatment  just  detailed  gives  rise  to  two  stanniferous  residuums,  which  have  te 
be  smelted  again.    These  are — 

1.  The  scoriae  b  and  c,  which  contain  some  granulated  particles  of  tin. 

2.  The  dross  found  on  the  bottom  of  the  reverberatory  furnace,  after  re-melting  the  tin 
to  refine  it. 

The  scoriae  c,  are  smelted  without  any  preparation ;  but  those  marked  b,  are  stamped 
in  the  mill,  and  washed,  to  concentrate  the  tin  grains ;  and  from  this  rich  mixture,  called 
frillion,  smelted  by  itself,  a  tin  is  procured  of  very  inferior  quality.  This  may  be  readily 
imagined,  since  the  metal  which  forms  these  granulations  is  what,  being  less  fusible  than 
the  pure  tin,  solidified  quickly,  and  could  not  flow  off  into  the  metallic  bath. 

Whenever  all  the  tin  blocks  have  thoroughly  undergone  the  process  of  liquation,  the 
fire  is  increased,  to  melt  the  less  fusible  residuary  alloy  of  tin  with  iron  and  some  other 
metals,  and  this  is  run  out  into  a  small  basin,  totally  distinct  from  the  refining  basin. 
After  this  alloy  has  reposed  for  some  time,  the  upper  portion  is  lifted  out  into  block 
moulds,  as  impure  tin,  which  needs  to  be  refined  anew.  On  the  bottom  and  sides  of  the 
basin  there  is  deposited  a  white,  brittle  alloy,  with  a  crysUUine  fracture,  which  contains 
so  great  a  proportion  of  foreign  metals,  that  no  use  can  be  made  of  it.  About  three  au^ 
a  half  tons  of  coal  are  consumed  in  producing  2  of  tin. 

Smelting  of  tin  by  the  blast  /umace.— This  mode  of  reduction  employs  only  wood 


857 


charcoal,  and  its  object  is  to  obtain  tin  of  the  maximum  purity  to  which  it  can  be  broueh 
by  man  ufacturmg  processes.     The  better  ores  of  the  stream-works,  and  the  finer  tin  sands, 
are  selected  for  this  operation.     The  washings  being  always  well  performed,  the  oxyde 

Slinl^ilf  .^fi>F/  k""™  ^^""'y  arsenical  or  sulphurous  impurity,  and  is  associated  with  no- 
thing but  a  little  hematite.     It  is  therefore  never  calcined. 

The  smelting  is  effected  without  addition;  only,  in  a  few  cases,  some  of  the  reeiduary 
matters  of  a  former  operation  are  added  to  the  ore.     About  a  ton  and  six  tenths  of  wood 
charcoal  are  burned  for  one  ton  of  fine  smelted  tin.    The  only  rule  is,  to  keep  the  furnace 
always  full  of  charcoal  and  ore.     The  revived  tin  is  received  immediately  in  the  first 
basin ;  then  run  off  into  the  second,  where  it  is  allowed  to  settle  for  some  time     The 
scoriae  that  run  off  into  the  first  basin,  are  removed  as  soon  as  they  fix.    These  «5coriiB 
are  divided  m to  two  classes;  namely,  such  as  still  retain  tin  oxyde,  and  sucll  as  hold 
none  oi  the  metal  m  that  state,  but  only  in  granulations.    The  metallic  bath  is  divided 
by  repose,  into  horizontal  zones,  of  different  degrees  of  purity ;  the  more  compound  and 
denser  matters  falling  naturally  to  the  bottom  of  the  basin.     The  tin  which  forms  the  su 
perior  zones,  being  judged  to  be  pure  enough,  is  transvased  by  ladles  into  the  refining 
basin,  previously  heated,  and  under  which,  if  it  is  of  cast-iron,  a  moderate  fire  is  applied 
1  he  tin  near  the  bottom  of  the  receiving  basin  is  always  laded  out  apart,  to  be  aeaiiJ 
smelted ;  sometimes,  indeed,  when  the  furnace  is  turning  out  very  impure  tin  none  of  it 
is  transvased  into  the  second  basin ;  but  the  whole  is  cast  into  moulds,  to  be  again  treated 
m  the  blast  furnace. 

In  general  they  receive  no  other  preparation,  but  the  green  wood  ebullition,  before 
passing  into  the  market.  Sometimes,  however,  the  block  of  metal  is  j  eated  till  it  be- 
comes brittle  when  it  is  lifted  to  a  considerable  height,  and  let  fall,  by  which  it  is  broken 
to  pieces,  and  presents  an  agglomeration  of  elongated  grains  or  tears:  whence  it  is  called 
gram  tin. 

On  making  a  comparative  estimate  of  the  expense  by  the  blowing-hcuse  process,  and 
by  the  reverberatory  furnace,  it  has  been  found  that  the  former  yields  about  66  per  cent 
of  tm,  m  smelting  the  stream  or  alluvial  ore,  whose  absolute  contents  are  from  76  to  78 
parts  of  metal  in  llie  hundred.  One  ton  of  tin  consumes  a  ton  and  six  tenths  of  wood 
charcoal,  and  suflers  a  loss  of  15  per  cent.  In  working  with  the  reverberatory  furnace 
It  IS  calculated  that  ore  whose  mean  contents  by  an  exact  analysis  are  70  per  cent.,  yields 
65  per  cent,  on  the  great  scale.  The  average  value  of  tin  ore,  as  sold  to  the  smelir,  is 
60  pounds  sterling  per  ton  ;  but  it  fluctuates,  of  course,  with  the  market  prices.  In  1 824, 
the  ore  of  inferior  quahty  cost  30/.,  while  the  purest  sold  for  60/.  One  ton  of  tin,  ob- 
tained from  the  reverberatory  furnace,  cost— 

1 J  tons  of  ore,  worth         ---.-.        £J5     q    q 

If  tons  of  coals,  at  10s.  per  ton         -        -        .        .  0  17    6 

Wages  of  labor,  interest  on  capital,  &,c.    -        -        -  3     0    0 


78  17  6 
On  comparing  these  results  with  the  former,  we  perceive  that  in  a  blowing-house  the 
loss  of  tm  IS  15  per  cent.;  whereas  it  is  only  5  in  the  reverberatory  furnace  The  ex- 
pense m  fuel  IS  likewise  much  less  relatively  in  the  latter  process;  for  only'lf  tons  of 
coals  are  consumed  for  one  ton  of  tin  ;  while  a  ton  and  six  tenths  of  wood  charcoal  are 
burned  to  obtain  the  same  quantity  of  tin  in  the  blowing-house;  and  it  is  admitted  that 
one  ton  of  wood  charcoal  is  equivalent  to  two  tons  of  coal,  in  calorific  effect.  Hence  everv 
thing  conspires  to  turn  the  balance  in  favor  of  the  reverberatory  plan.  The  operation 
is  also,  m  this  way,  much  simpler,  and  may  be  carried  on  by  itself.  The  scoria,  besides, 
from  the  reverberatory  hearth,  contain  less  tin  than  those  derived  from  the  same  or« 
Ueated  with  charcoal  by  the  blast,  as  is  done  at  Altenberg.  It  must  be  remembered,  how- 
ever,  that  the  gram  tm  procured  by  the  charcoal  process  is  reckoned  to  be  finer,  and 
fetches  a  higher  price ;  a  superiority  partly  due  to  the  purity  of  the  ore  reduced  and 
partly  to  the  purity  of  the  fuel.  '  ^^ 

To  test  the  quality  of  tin,  dissolve  a  certain  weight  of  it  with  heat  in  muriatic  acid : 
Should  It  contain  arsenic,  brown-black  flocks  will  be  separated  during  the  solution,  and 
arseniureted  hydrogen  gas  will  be  disengaged,  which,  on  being  burned  at  a  jet,  will 
fwlthlfl  "'"^V?f^^^  film  of  metallic  arsenic  upon  a  white  saucer  held  a  little  way 
above  the  flame.  Other  metals  present  m  the  tin  are  to  be  sought  for,  by  treating  thj 
above  solution  with  nit"P/cid  of  spec.  grav.  M6,  first  in  the  cold,  and  it  last  with  heat 
and  a  small  excess  of  acid.  When  the  action  is  over,  the  supernatant  liquid  is  to  be  de- 
canted  off  the  peroxydized  tin,  which  is  to  be  washed  with  very  dilute  nitric  acid,  and  both 
Uquors  are  to  be  evaporated  to  dissipate  the  acid  excess.  If,  on  the  addition  of  water 
to  the  concentrated  liquor,  a  white  powder  falls,  it  is  a  proof  that  the  tin  contains 
bismuth;  if  on  adding  sulphate  of  ammonia,  a  white  precipitate  appears,  the  tin  con- 
lams  lead  j  water  of  ammonia  added  to  supersaturation,  will  occasion  reddish-brown 


:| 


858 


TIN. 


TIN. 


A. 


flocks,  if  iron  is  present;  and  on  evaporating  the  anpernatant  liquid  to  dryness,  the 
copper  will  be  obtained. 

'Ae  uses  of  tin  are  very  numerous.  Combined  with  copper,  in  diflferent  proportions, 
it  forms  bronze,  and  a  series  of  other  useful  alloys ;  for  an  account  of  which  see  Odppeb. 
With  iron,  it  forms  tin-plate ;  with  lead,  it  constitutes  pewter,  and  solder  of  various 
kinds  (see  Lead).  Tin-foil  coated  with  quicksilver  makes  the  reflecting  surface  of  glass 
mirrors.  (See  Glass.)  Nitrate  of  tin  att'ords  the  basis  of  the  scarlet  dye  on  wool,  and 
of  many  bright  colors  to  the  calico-printer  and  the  cotton-dyer.  (See  Scarlet  and  Tin 
Mordants.)  A  compound  of  tin  with  gold  gives  the  fine  crimson  and  purple  colors  to 
stained  glass  and  artificial  gems.  See  Purple  of  Cassius.  Enamel  is  made  by  fusing 
oxide  of  tin  with  the  materials  of  flint  glass.  This  oxide  is  also  an  ingredient  in  the 
white  a«d  yellow  glazes  of  potters-ware. 

The  Exhibition  contained  a  series  of  specimens,  illustrative  of  an  improved  process 
for  dressing  ores  of  tin  containing  wolfram  (the  tungstate  of  iron  and  manganese,  in- 
vented by  Mr.  R.  Oxland,  of  Plymouth,  for  the  separation  of  the  wolfram  from  the  ores 
of  the  Drake  Walls  tin  mine,  on  the  Cornish  side  c  the  river  Tamar.  This  process  is 
now  in  regular  operation  at  the  mine.  In  consequence  of  the  specific  gravity  of  wolf- 
ram, which  is  from  7100  to  7-600,  being  greater  than  that  of  the  black  tin  of  the  mines 
or  the  pure  native  oxide  of  tin,  which  is  only  from  6'3  to  7*0,  it  has  been  found  impos- 
sible to  separate  the  wolfram  from  the  tin  oxide  by  the  usual  mechanical  process  of 
washing  in  a  stream  of  water.  This  led  to  the  necessity  of  adopting  the  patent  chemi- 
cal process  explained,  with  the  description  of  the  series  of  specimens. 

No.  1,  "Tin  witts:"  the  ore  obtained  from  the  stamp-floors,  where,  subsequentiy  to 
its  having  been  crushed  or  stamped  down  to  a  suitable  size,  it  has  been  washed  in  a 
stream  of  water,  in  order  to  separate  the  earthy  particles  with  which  it  was  associated. 
The  clean  "  witts"  contain  the  native  oxide  of  tin ;  black  tin  or  resin  tin,  and  wolfram 
with  iron  and  arsenical  pyrites,  generally  containing  some  copper.  In  the  course  of 
washing,  the  "  witts"  are  sorted  into  different  parcels,  according  to  the  size  of  the 
particles,  and  are  known  as  jigged,  marked  A;  flucan,  B;  smalls,  or  "8male8,"C: 
slime,  D ;  roughs  or  rows,  R  The  "  witts"  are  calcined  in  a  reverberatory  furnace, 
usually  constructed  of  fire-bricks  throughout  The  calcination  is  continued  until  all 
the  sulphur  and  arsenic  is  evolved. 

The  residue  of  No.  2  contains  black  tin  or  native  tin  oxide,  peroxide  of  iron,  wolfram, 
some  sulphate  of  copper,  and  a  small  quantity  of  earthy  matter.  By  a  series  of  wash- 
ing operations  on  the  burning  house  floors,  the  peroxide  of  iron,  sulphate  of  copper, 
and  earthy  matters,  are  removed,  and  the  product  obtained  is  No.  3,  which  consists  of 
oxide  of  tin,  with  most  of  the  wolfram.  The  process  is  in  the  next  place  employed  for 
the  removal  of  the  wolfram.  Its  proportion  having  been  ascertained  by  analysis,  a 
quantity  of  sulphate  of  soda  or  salt  cake  is  mixed  with  the  ore,  suflBcient  to  supply  a 
slight  excess  equivalent  of  soda  for  the  quantity  of  tungstic  acid  present ;  but  with  the 
sulphate  of  soda  must  be  mixed  suflBcient  coal  dust  or  charcoal  to  afford  carbon  or  car- 
buretted  hydrogen,  for  the  decomposition  of  the  sulphuric  acid  and  the  conversion  of 
sulphate  of  soda  into  sulphide  of  sodium.  The  mixture  is  exposed  to  heat  on  the  bed 
of  the  furnace  described  below ;  a  smoky  or  reducing  flame  is  at  first  employed,  but 
after  the  whole  of  the  chaise  has  been  at  a  red  heat  for  some  time  an  oxidating  flame 
is  necessary  to  complete  the  operation.  Thus  the  sulphate  of  soda  is  first  converted 
into  sulphide  of  sodium,  then  the  tungstic  acid  of  the  wolfram  combines  with  the  soda, 
producing  tungstite  of  soda,  setting  the  sulphur  free  as  sulphurous  acid,  and  leaving  the 
iron  in  the  condition  of  a  light,  finely  divided  peroxide. 

The  product  No.  4  is  drawn  from  the  furnace  into  the  wrinkle  or  chamber  beneath, 
and  is  thence  removed  whilst  still  hot  into  tanks  containing  water,  which  quickly  di»« 
solves  the  tungstate  of  soda.  The  solution  is  run  off  into  receivers,  and  the  residue  is 
removed  to  the  burning  house  floors,  where  by  a  series  of  washings  the  peroxide  is  re- 
moved, and  the  native  oxides  of  tin  obtained  pure  and  ready  for  the  smelting  house  as 
seen  in  No.  5 :  an  ore  which  had  fetched  only  42^.  per  ton  has  by  this  operation  been 
BO  much  improved  in  quality  as  to  obtain  56/.  per  ton. 

The  tungstate  of  soda.  No.  6,  is  obtained  in  the  crystalline  form  by  the  evaporation 
to  the  crystallizing  point  of  the  solution  in  which  it  was  separated  from  the  tin.  It  is 
proposed  to  be  used  as  a  substitute  for  stannite  of  soda,  a  mordant  for  dyeing 
purposea 

Tungstic  acid,  No.  7,  may  be  employed  for  the  same  purpose  or  for  the  manu- 
facture of  tungstate  of  the  tungstous  oxide  with  soda,  a  compound  much  resembling 

gold. 

The  tungstate  of  lead.  No.  8,  and  tungstate  of  lime.  No.  9,  are  good  white  pigments 
(manufactured  from  the  tungstate  of  soda),  from  which  was  also  obtained  the  metallic 
tungsten.  No.  10,  and  sulphuret  of  tungsten,  No.  11.  The  former  is  for  use  in  the 
manufacture  of  metallic  alloys;  the  latter  has  been  proposed  as  a  substitute  for  black 


859 


lead.  The  fiimace  is  composed  in  the  usual  manner,  excepting  that  a  cast-iron  bed 
has  been  emp  oyed  to  prevent  the  loss  that  would  arise  from  the  reaction  of  the  silica 
of  the  bricks  the  soda  and  the  tin  oxide  on  each  other.  The  fire  after  passing  over  the 
bed  IS  made  to  circulate  beneatii  it  before  passing  away  to  the  chimney. 

.liiSflt  «r^^^'"!u'°^  ^*'''^''  ^^  *^^'  ""^"^  ^^«  ^'"o^^  «"«'ng  from  Uie  furnace  is 
Sf  T  ^^J^^^^^^th  noxious  vapors,  containing  besides  other  poisonous  matters  a  large 

?vT^  L  tfl  "^1^^  l^^'"'P*'  ^^^^  ^^*°  "^^^^  *«  «^^«t«  this  nuisance;  and  the 
system  adopted  by  the  exhibitor  has  been  found  to  be  very  successful 

tinn  JliT  •  ^.  building  in  solid  masonry,  about  80  feet  in  height,  is  divided  by  a  parti- 
tion  wall  into  two  chambers,  having  a  tall  chimney  or  towSr  adjoining,  which  com- 
municates  with  one  of  the  chambers  at  the  bottom.  The  smoke  froS  The  varTo^ 
furnaces,  8  in  number  and  about  100  yards  distance  from  the  condenser,  is  cafried  by 
separate  flues  into  a  large  chamber;  from  thence  by  a  large  flue  it  ekters  the  first 
chamber  of  the  condenser  at  the  very  bottom,  and  is  forced  upward  in  a  zigzag  coui^ 
towards  the  top,  passing  four  times  through  a  shower  of  water,  constantly  percolating 
IZr  \  £ff W-  '•^!t™ V<^  the  summit  of  the  tower.  The  smoke  is  again  compeUed  to 
hlter  a  fifth  time  through  a  cube  of  coke  some  two  feet  square,  tiirough  wkich  a  stream 

gLTng  of  woo'd  ^"^°^"^^^'  «°^  ^^'^^  ''  «°"fi°^^  to  iS  proper  liSte  by  a  verticS 
The  smoke  having  reached  the  top  is  now  opposite  the  passage  into  the  second  or 
vacuum  chamber  This  is  termed  the  exhaustiJJg  chambe?,  anf is  abou^VfTby  7 
feet  mside,  and  30  or  more  feet  in  height  On  its  summit  is  fixed  a  large  reservoir 
^ttnf^  ^"  ample  stream  of  water,  always  maintaining  a  depth  of  6  to  10  inches. 

Ihe  bottom  of  this  tank  is  of  iron  having  several  openings  or  slots,  12  in  number  and 
about  an  inch  in  width,  and  extending  across  the  whole  area  of  the  reservorcommu- 
mcating  directly  with  the  chamber  beneath.  On  this  iron  plate  workra  hyXX 
side-plate  with  openings  corresponding  in  one  position  with  those  in  the  reservoir.  This 
plate  receives  a  horizontal  reciprocating  motion  from  a  water  wheel  or  other  powS 
driven  by  means  of  a  connecting  rod  and  crank.  power. 

In  the  middle  of  every  stroke  the  openings  in  the  plate  correspond  with  those  in  the 
bottom  ot  the  reservoir,  and  a  powerful  body  of  water  falls  as  a  shower  bath  the  whole 
length  of  the  vacuum  chamber,  and  in  doing  so  sweeps  the  entire  inside  area  ca^yW 

Se  furnareZ  ^         "  "'  "'''"^''  "'''''  ^'^^  ^"^^^"^^^  ^^  '^'  y^V-^^^^^^l^l 
The  atmospheric  pressure  of  course  acts  in  alternate  strokes,  as  a  blast  at  the  furnace 
rHon^"  T^  '^?'-'  *  ^''"^^'  sufficiently  strong  to  force  the  impure  vapors  through  the 
var  ous  channels  in  connection  wi^th  the  water,  the  wet  coke,  and  exhausting  chamber 
until  It  passes  purified  and  inert,  into  the  atmosphere.  ^  ' 

n«S!  w  ^''  «at»rated  witii  particles  of  lead,  Ac,  held  in  mechanical  solution,  finally 
ScrcVa^g^^/tta^'"  ^^  ^"^^^^"^  '^'^^^''^  ^-  ^^^  P-P-'  -^  there  depo^U  iS 

« Jtl^T^^I  *^^i^'^  arrangement  are  most  apparent  and  beneficial  to  the  surroundincr 
neighborhood.     Formerly  the  noxious  fumes  passing  from  the  shaf^  of  th?^,^o.i 
poisoned  the  neighborhood ;  the  heather  wasVirnt^p  vegeLttn  desLoved  a^^^^^ 
animal  could  graze,  or  bird  feed  near  the  spot    Now  the  heftherX  seen  in^fuixfr^f nn^ 

halrb'er^rrcIpS^i/  ofEngland  appear  to 

been  verv  erudp  nn/l  fy,oi-».  t«..*„ii       •    i  ^^^  modes  of  working  must  have 

^  Till  a  comparatively  recent  date,  tin  was  the  only  metal  which  was  souSt  for  •  ar,^ 
!^  r.°J.llT  n'  rn'  r'  abandoned  when  the  miner'  cime  to  t^e  ">eIlo^^^^^^  thai 
^sti^aSvl  l«r*  "^.rPP?- .  The  greatest  quantity  of  tin  has  been  prol^ced  by 

streaming  (as  washing  the  debris  in  the  valleys  is  termed) ;  and  this  variety  callSl 
"stream  tin,"  produces  the  highest  price  in  the  market  ^' 

The  conditions  under  which  these  deposites  occur  are  curious  and  instructiye.    At  the 


860 


TIN. 


TIN. 


861 


IHPf  nff 


tei 


Carnon  Tin  Stream  Works,  near  of  Falmouth,  the  rotnded  pebbles  of  tin  are  found 
at  a  depth  of  about  60  feet  from  the  surface,  beneath  the  bottom  of  an  estuary,  where 
trees  are  discovered  in  their  place  of  growth,  together  with  human  skulls,  and  the 
remains  of  deer,  amidst  the  vegetable  accumulation  which  immediately  covers  the 
stanniferous  bed&  According  to  Mr.  Kenwood's  measurement,  the  section  presents 
first  about  50  feet  of  schlieh  and  gravel;  then  a  bed  of  18  inches  m  thickness  of  wood, 
leaves,  nuts,  &c.,  restmg  on  the  tin  ground,  composed  of  the  debris  of  quartz,  slate,  and 
granite,  and  the  tin  ore.  At  the  Pentuan  Works,  near  St  Austell,  similar  deposits, 
occur,  proving  a  material  alteration  in  the  level,  during  the  period  expended  m  the 
formation  of  this  deposit  Tin  is  also  worked  out  of  the  lode  in  many  parts,  the  ore 
occurring  both  in  the  slate  and  granite  formations.  The  modes  of  •'  dressing  the  tin 
ore,  jpreparing  it  for  the  smelter,  and  the  process  of  smelting,  were  illustrated  in  the  Ex- 
hibition. 

There  has  been  a  remarkable  uniformity  in  the  quantity  of  tin  produced  in  Cornwall, 
during  a  long  period,  as  will  be  seen  from  the  following  table : — 


Yean. 

Tons. 

Prices  per  cwt 

&        s. 

1750 

1,600 

1760 

1,800 

1770 

2,000 

1780 

1,800 

S   0 

1790 

2,000 

8  15 

1800 

1,500 

5   0 

1810 

1,400 

7   0 

1820 

1,700 

8   6 

1830 

8,500 

8   0 

1840 

6,000 

8  15 

The  produce  of  this  metal  within  the  last  few  years  has  been  as  follows :— 


Years. 

Tons. 

1844 

7,507 

1845 

7,739 

1846 

8,945 

1847 

10,072 

1848 

10,176 

1849 

10,719 

Since  1838  the  quantity  cannot  be  accurately  ascertained,  the  trade  in  tin  being  in 
the  hands  of  a  few,  and  the  purchase  of  ore  being  usually  made  by  private  contract— 
See  Metallic  Statistics. 

Tin  coating  of  iron  and  zinc,  by  Mr,  Morries  Sterling's  patent  process.  Th%  first 
improvement  in  coating  metals  or  alloys  of  metals  with  other  metals  or  their  alloys^ 
relates  to  coating  iron  with  tin  or  its  alloys  after  the-  iron  has  been  coated  with  zinc. 
For  this  purpose  the  sheet,  plate,  or  other  form  of  iron,  previously  coated  with  zdnc^ 
either  by  dipping  or  by  depositing  from  solutions  of  zinc,  is  taken,  and  after  cleaning 
the  surface  by  washing  in  acid  or  otherwise,  so  as  to  remove  any  oxide  or  foreign  mat- 
ter which  would  interfere  with  the  perfect  and  equal  adhesion  of  the  more  fusible 
metal  or  alloy  with  which  it  is  to  be  coated,  it  is  dipped  into  melted  tin,  or  an^  suita- 
ble alloy  thereof  in  perfectly  fluid  state,  the  surface  of  which  is  covered  with  any 
suitable  material  such  as  fatty  or  oily  matters,  or  the  chloride  of  tin,  so  as  to  keep  the 
surface  of  the  metal  from  oxidation ;  and  such  dipping  is  to  be  conducted  in  a  like 
manner  to  the  process  of  making  tin  plate  or  of  coating  iron  with  zinc.  When  a  fine 
surface  is  required,  the  plates  or  sheets  of  iron  coated  with  zinc  may  be  passed  between 
polished  rolls  (as  already  described)  before  and  after,  or  either  before  or  after  they  are 
coated  with  tin  or  other  alloy  thereof.  It  is  preferred  in  all  cases  to  use  for  the  coat- 
ing pure  tin  of  the  description  known  as  grain  tin. 

Another  part  of  the  invention  consists  in  covering  either  (wholly  or  in  part)  zinc  and 
its  alloys  with  tin,  and  such  of  its  alloys  as  are  sufficiently  fusible.    To  effect  this,  the 


following  is  the  process  adopted :— A  sheet  or  plate  of  zinc  (by  preference  such  as  has 
been  previously  rolled,  both  on  account  of  its  ductility  and  smoothness)  is  taken,  and 
after  cleaning  ita  surface  by  hydrochloric  or  other  acid,  or  otherwise,  it  is  dried,  and 
then  dipped  or  passed  in  any  convenient  manner  through  the  melted  tin,  or  fusible 
alloy  of  tin.    It  is  found  desirable  to  heat  the  zinc,  as  nearly  as  may  be,  to  the  temper- 
ature of  the  melted  metal,  previous  to  dipping  it,  and  to  conduct  the  dipping,  or  passing 
through,  as  rapidly  as  is  consistent  with  thorough  coating  of  the  zinc,  to  prevent  as 
much  as  possible  the  zinc  becoming  alloyed  with  the  tin.     It  is  recommended  also  that 
the  tin  or  alloy  of  tin  should  not  be  heated  to  a  higher  temperature  than  is  necessary 
for  its  proper  fluidity.     The  metal  thus  coated,  if  in  the  form  of  sheet,  plate,  or  cake,  can 
then  be  rolled  down  to  the  required  thickness;  and  should  the  coating  of  tin  or  alloy  be 
found  insufficient  or  imperfect,  the  dipping  is  to  be  repeated  as  above  described,  and  the 
rolling  also  if  desired,  either  for  smoothing  the  surface  or  further  reducing  the  thickness. 
Another  part  of  the  invention  consists  in  coating  lead  or  its  alloys  with  tin  or  alloys 
thereof.     The  process  is  to  be  conducted  as  before  described  for  the  coating  of  zinc,  and 
the  surface  of  lead  is  to  be  perfectly  clean.     The  lead  may,  like  the  zinc,  be  dipped  more 
than  once,  either  before  or  after  being  reduced  in  thickness  by  rolling.     The  hydraulic 
press  may  be  advantageously  employed  in  the  process  of  coating  lead  or  its  alloys  with 
tm  or  its  alloys;  and  this  process  is  already  practised  and  well  understood,  as  applied 
to  the  coating  of  lead  pipe  with  tin;  it  is  only  necessary  to  remark  that  a  die  or  orifice 
must  be  used  of  such  length  and  width  as  will  allow  an  ingot  cake  or  sheet  to  be  formed. 
On  both  sides  of  this  cake  or  sheet,  melted  tin  is  to  be  poured  into  a  suitable  receptacle, 
as  is  well  understood  in  the  making  of  pipe ;  but  where  only  one  side  or  portion  of  the 
cake,  ingot,  or  sheets  is  to  be  tinned,  a  partition  or  division  should  be  placed  to  confine 
the  melted  tin,  so  that  it  shall  only  be  applied  to  that  portion  of  the  lead  which  is  re- 
quired to  be  tinned.     Where  a  smooth  surface  is  required,  the  cake  or  other  form  of 
lead  18  to  be  passed,  while  in  a  heated  state,  through  a  collar  of  suitable  hard  and 
smooth  material,  such  as  hardened  steel  or  iron,  kept  as  cool  as  may  be.     Where  a 
strong  coating  of  tin  is  required,  the  lead  so  coated  is  to  be  passed  through  melted  tin. 
Such  coated  lead,  or  its  alloys,  may  be  reduced  by  rolling;  and  where  the  lead  so  coated 
18  to  be  reduced  to  extreme  thickness,  the  further  coating  is  advantageously  given  after 
the  coated  metal  has  been  reduced  to  some  extent  by  rolling.     Any  number  of  addi- 
tional coatings  may,  in  a  similar  manner,  be  given,  according  to  the  purpose  for  which 
the  coated  lead  is  required.     In  coating  lead  or  its  alloys  with  tin,  it  is  recommended 
wk      1   PTO^f  ^  ^^«^®  a  surface  of  lead  is  to  be  avoided,  pure  tin  should  be  used. 
When  lead  is  alloyed  with  antimony,  zinc,  tin,  or  any  other  metal,  to  render  the  lead 
more  hard  than  lead  m  its  ordinary  state,  the  tin  coating  may  also  be  somewhat  hard- 
ened by  alloying  with  zinc  or  other  suitable  hardening  metal. 

Lead  and  its  alloys  may  also  be  coated  with  tin  or  its  alloys  of  greater  fusibility  than 
the  metal  to  be  coated  as  follows :— The  cake,  or  other  form  to  be  coated,  is  to  be  placed 
as  soon  after  casting  as  mav  be  in  an  iron,  gun  metal  or  other  suitable  mould,  or  if  thia 
can  not  be  conveniently  done,  the  surfaces  are  to  be  cleansed  and  prepared,  for  the 
reception  of  the  coating  metal,  either  by  previously  tinning  the  surface,  or  by  applying 
other  suiteble  material  to  facilitate  the  union,  as  heretofore  practised.  At  one  end  of 
the  mould  18  to  be  attached  chambers,  of  more  than  sufficient  capacity  to  contain  the 
quantity  of  metal  to  be  used  for  coating,  which  may  with  advantage  form  an  integral 
part  of  the  mould,  or  such  chamber  may  surround  the  mould,  and  by  one  or  more  sluices 
or  valves  in  such  chamber  or  chambers,  the  melted  metal  is  to  be  allowed  to  run  on  to 
the  surface  of  the  metal  to  be  coated,  when  the  metal  is  to  be  coated  on  one  side  only. 
When  It  IS  mtended  to  coat  the  metal  on  both  sides,  the  vertical  position  will  be  found 
convement^  and  the  coating  metal  is  to  be  formed  into  a  chamber  or  chambers  attached 
to  the  mouldy  and  to  be  introduced  into  the  lower  part  of  the  mould  by  opening  a  sluice 
or  valv^  sufficient  space  being  left  on  each  side  of  the  cake  or  other  form  to  alfow  of  the 
coating  being  of  the  required  thickness ;  the  sluice  or  valve  should  be  of  nearly  the  width 
fLl"?.  tbe  cake  or  other  form,  and  the  melted  metal  should  be  aUowed  to  flow  into 
toe  bottom  of  the  mould  (Mr.  Stirling  here  observes,  that  he  is  aware  that  lead  has 

S!!f  if  T""^^  ^A'i?*^'^'^'^^  ^''^  ^7  P^"^^"g  ^i'l  "P«°  ^^^  lead,  and  also  by  pressure,  and 
toat  he  does  not  therefore  claim  the  coating  of  lead  by  such  means).  The  surface  of  the 
plate  or  cake  ought  to  be  smooth  and  true,  and  the  mould,  if  horizontal,  to  be  perfocUy 
80^  and  If  upright,  quite  perpendicular,  so  as  to  insure  in  either  case  an  equal  footing. 
The  surface  of  the  lead  should  also  be  clean,  and  it  wiU  be  found  advantageous  to  rai^ 
Its  temperature  to  a  pomt  somewhat  approaching  the  melting  point  of  tin?r  of  the  alloy 
employed  for  coating,  as  by  this  means  the  union  of  the  two  metals  is  facilitated.  It  ik 
recommended  also  that  a  somewhat  larger  quantity  of  the  tin  or  alloy  than  is  necessary 
for  the  coating  of  the  lead  or  other  metal,  or  alloy,  should  be  emploved,  and  that  when 
the  requisite  thickness  of  coating  has  been  given,  the  flow  of  Uie  coating  metal  be  stopped, 
•8  by  this  means  the  impurities  on  the  surface  of  the  tin  wiU  be  prevented  passing 


862 


TIN-PLATE. 


il 


m%\ 


K 


tiirongh  the  opening  on  to  the  surface  of  the  cate:  the  chamber  or  chambers  should 
be  kept  at  such  temperature  as  to  ensure  the  proper  fluidity  of  the  coating  metal 
Zinc  and  its  alloys  may  m  like  manner  be  coated  with  tin  and  its  alloys,  by  employing 
a  bke  apparatus  to  that  just  described  for  coating  lead  and  its  alloys,  knd  it  constitutJ 
a  part  of  this  invention  thus  to  coat  zinc.  The  coating  of  zinc  with  tin,  however,  is 
not  claimed,  that  having  been  done  by  pouring  on  tin. 

Another  part  of  the  invention  consists  in  coating  zinc  and  its  alloys  with  tin  and  its 
a  oys  by  pressure.  For  this  purpose  Mr.  Stirling  takes  a  suitable  piece  of  zinc  or 
alloyed  zmc  (by  preference  previously  rolled),  and  when  it  is  desired  to  coat  it  on 
both  sides  with  tin  or  alloyed  tin,  of  sufficient  dimensions  to  completely  cover  the  zinc. 
He  then  subjects  the  metal  so  placed  to  pressure,  to  obtain  perfect  contact-  and  for 
this  purpose  when  making  shee^  he  employs  rolls,  and  rolls  out  the  two  metkls  to  the 
extent  desired. 

The  last  part  of  the  invention  relates  to  the  employment  of  zinc  when  welding  to- 

gether  plates  or  other  forms  of  iron,  which  is  principally  applicable  when  piling  Iron, 

Thm  sheet  zinc,  placed  between  the  layers,  has  been  found  to  answer  well;  but  the 

use  of  calamine,  m  the  form  of  powder  or  paste,  is  preferred.     In  the  latter  case  the 

paste  may  be  formed  with  water,  to  which  a  small  quantity  of  borax  may  be  added  • 

the  paste  can  be  then  applied  with  a  brush  or  otherwise,  to  the  surface  of  the  plates 

or  other  forms  of  iron.     Additional  stiffness  and  toughness  are  produced  by  this  process. 

^tatVi  A?^^^  ^^^^V^  believed  to  be  more  particularly  benefited  thereby. 
1  INC  AL,  crude  borax.  ^ 

TINCTORIAL  MATTER.  One  of  the  most  curious  and  valuable  facts  ascertained 
mpon  this  subject,  is,  that  madder  kept  in  casks,  in  a  warm  place,  undergoes  a  species  of 
lermenlation,  which,  by  ripening,  or  rather  deoxydizing  the  coloring-matter,  increases  its 
dyeing  power  by  no  less  than  from  20  to  50  per  cent.  See  M.  H.  Schlumberger's  memoir 
read  to  the  Societe  Indusinelle  de  Mulhausen,  24  November,  1837. 

riNCTURE  is  a  title  used  by  apothecaries  to  designate  alcohol,  in  a  somewhat 
substlnce*^  '   impregnated  with  the  active  principles  of  either  vegetable  or  animal 

TIN-GLASS  is  a  name  of  bismuth. 
TIN  MORDANTS,  for  dyeing  scarlet  :— 

M(yrdant  a,  as  commonly  made  by  the  dyers,  is  composed  of  8  parts  of  aquafonis, 
Sncertair™"*'''  '      '''"       ammoniac,  and  1  of  granulated  tin.    This  preparation  it  ver^ 
M^dant  B.-Pour  into  a  glass  globe,  with  a  long  neck,  3  parts  of  pure  nitric  acid  at 

Z.J  ^  f  ^  ""^  T"^^'""  ^""'^  ^^  ^'^°  5  shake  the  globe  gently,  avoiding  the  corro- 

sive  vapors,  and  put  a  loose  stopper  in  its  mouth.  Throw  into  this  nitro-muriatic  acid 
one  eighth  of  its  weight  of  pure  tin,  in  small  bits  at  a  time.  When  the  solution  is  com- 
plete and  settled,  decant  it  into  bottles,  and  close  them  with  ground  stoppers.  It  should 
be  diluted  only  when  about  to  be  used. 

.J!rfr^  ""'■  ^^  ?ambourney.-In  two  drachms  Fr.  (144  grs.)  of  pure  muriatic  acid,dis. 
solve  18  grains  of  Malacca  tin.  This  is  reckoned  a  good  mordant  for  brightening  or 
hxing  the  color  of  peachwood.  ^         ^ 

^J^<^dant^  by  Hellot.— Take  8  ounces  of  nitric  acid,  diluted  with  as  much  water; 
disso  ve  m  it  half  an  ounce  of  sal  ammoniac,  and  2  drachms  of  nitre.     In  this  acid  solution 

mt:^::eZry>:i^^t' '" ''  "^"""^"^  ^'"^"^"^  "°^  ^°  ^^^  ^^  ^  ^^^^^  p^^- 

Mwdant  e,  by  Scheffer.— Dissolve  one  part  of  tin  in  four  of  a  nitro-muriatic  acid,  nre- 
sa/ammonia"c^'"'''  ^""'^  ^^^""^^^  ^'^^^  '^^  °'^''  ^^'^^^  ""^  '^**"'  ^^  """^  thirty-secondth  of 

JfordantF  by  Poerner.--Mix  one  pound  of  nitric  acid  with  one  pound  of  water,  and 
dissolve  m  it  an  ounce  and  a  half  of  sal  ammoniac.  Stir  it  well,  and  add,  by  very  slow 
degrees  two  ounces  of  tin  turned  into  thin  ribands  upon  the  lathe. 

Mordant  g,  by  Berthollet.-Dissolve  in  nitric  acid  of  30°  B.  one  eighth  of  its  weight 

tinnlT^''"  r"'  ^^uV^^  by  degrees  one  eighth  of  its  weight  of  tin,  and  dilute  the  soln- 
tion  with  one  fourth  of  its  weight  of  water. 

Mordant  k,  by  Dambourney.— In  one  drachm  (72  grs.)  of  muriatic  acid  at  17°,  one  of 
of  fine^Malacca  tin^  ^'^'"^  ""^  ^^^'''''  dissolve,  slowly  and  with  some  heat,  18  grains 

Mordant  L  is  the  birch  bark  prescribed  by  Dambourney.— This  bark,  dried  and  ground, 
iS  said  to  be  a  very  valuable  substance  for  fixing  the  otherwise  fugitive  colors  pfoduced 
by  woods,  roots,  archil,  &c.  *  wu^^ou 

TIN-PLATE.  The  only  alloy  of  iron  interesting  to  the  arts  is  that  with  tin,  in  the 
formation  of  tin-plate  or  whtte-ir&n,  ' 

The  sheet  iron  intended  for  this  manufacture  is  refined  with  charcoal  instead  of  coke. 
subsequently  roUed  to  various  degrees  of  thinness,  and  cut  into  rectangles  of  different 


TIN-PLATE. 


863 


bo2s^/dT°or  fo^Hm^1?^^^^  ^'^'l  \  *  water-^heel,  which  will  turn  out  100 

ninff  is  to  free  thl  mP  in-  ^^V'^'^^J'^^  <5°fc  by  hand  labor.  The  first  step  toward  tin- 
«r,fii  •      -fVi     "^^^^^<^  surface  from  every  particle  of  oxyde  or  impurity,  for  any  sneh 

se^JitS^^^^^^^  *'Lr  '""i  ^"°^'^"5  -^^^  ^^^  ^--     TheTates  are  ne7t  beS 

IhTflame  mav  nil  ?  T^**^^  *"*  ^u'^'^P^'  ^"'^  '^"^^^  ^^  «  reverberatory  oven,  so  that 
ninna!J^^  f  ^^.^!t^  ^'^^^^  ^"°"^  ^^^°^»  ^""^  ^^at  them  to  redness.  They  are  then 
plunged  into  a  bath,  composed  of  four  pounds  of  muriatic  acid  diluted  with  three  laUons 

to  fl.  '  ^-^  *  ^r  "''""*"''  '^^""  «"*  ^"d  '^^^i^ed  «"  the  floor,  and  once  more  elpo^^ 
to  Ignition  m  a  furnace,  whereby  they  are  scaled,  that  is  to  say,  cast  IheTr  Tcales    '^ 

«t°ooth  ''^  ""'"  '"?''  ^'^.  ^^"^^"^  ^^^^  P'^^^«-  When  takenl',  they  arTbeafL^el lid 
smooth  on  a  cast-iron  block,  after  which  they  appear  mottled  blue  and  whie  if  the 

Lon  o?1  If  ^''"  i^°T^^^^  ?""!•    ^^'^  «^^  next  passed  through  chmed  Tolls  or  ciS^ 

Xtilid  hvT^'S'tl  r^^"^.^y  ^"^"^  '^''  ^"  '^''^  i^«"  °^«"Ws,  as  has  been  ^ 
pract  sed  by  the  Scotch  founders  in  casting  bushes  for  cart-wheels  After  Oii^nrripJ 
of  co/d  ro//mg,  the  plates  are  immersed,  for  ten  or  twelv"  Tours  in  aif  acSSoSs^ef 
Jjade  by  fermenting  bran-water,  taking  care  to  set  them  separa"e^y  on  ^ge  and  to  t„m 
them  at  least  once,  so  that  each  may  receive  a  due  share  of  the  oneraUon  From  th^ 
ley-steep  they  are  transferred -into  a  leaden  trough,  divided  by  parUtioTandchar^Jd  ^A 
diute  sulphuric  acid.  Each  compartment  is  called  a  hole  by  ^hrCkmen  and  is  caTc? 
}SUr''T7.'^^°"'  ^^^  plates,  the  number  afterwards  packerupTogether  in TiS' 

f^m  .    rt  '  u'^  ^'^  ^^'^^^  *^"'  ^"^  ^^"'■^  *•»  they  becoL  perfectly  bright  Lnd  ^ 
from  such  black  spots  as  might  stain  their  surface  at  the  time  of  unmSsion      Thi,  n^ 

rumsLcf         '"  ^'^^""'^  ^"'  '■™'"  ™^'  f"  "■"-y  months,  a  ver?remriablec" 

are  thence  removed,  with  the  Zherine  '"ease   int^  tt%i   ,"^^7"  i""-    ^^I 

the  superflu^metal^S  -^  - -^  Z^^^^S^  ^^  ^^^^^ 

plie^ltr?tt^hU^°cieL^^^^^^^  tin  the  workman  puts  the  above 

in  it,  for  keeping  the  droTof  tin ^h J  r  L  •  '"""^b  ^r^'^  ''  *  longitudinal  partiUon 
the  ast  dip  is  grven  Inde^  the  iL  '  \l  u^  ^'^^  "^"'"""^  '^'^  ^^^^^^  ^^^re 
70  boxes,  becomes  so  foul  that  th^wpiih/r  ^^^T\^J^^'  ^^^^"^  ^'''^  ««  6^  or 
into  the  lin-pot,  No.  1,  and  rep  aceS  Tv  f  frplh^K  f^^  ^"^'^^  V  ''  transferred 

lifted  out  of  ihe  wash-pot7w[th  tont  heVin  the  left  h^l^n^T  ''"*  ^  ^^'  ^^^'''  ^'^^ 
on  each  side  with  a  neculiar  hVm«^„  T    u  V  ,J  •     .  "^  °^  ^^^  workman,  are  scrubbed 

moment  in  Ihriot  tin  aS  forthwhhL  "'^'i'"^'^  i"  ^^-  '^'^^''  *^^"^'  ^^^^  ^^^PPed  for  a 
requires  manual  dexterity  ;an5lhou^^^^^^^^^^  ^"^'T^^  ^rease.j^oU  No"  3.    This 

washing  225  plates,  yet  a  good  wSan  cl^tT^^^^^  ^^Vl'  ^'^'^''^  ^"^  ^^' 

hours,  by  putting  5625  pktes  trro^TXis  hand"  Thl  &•  "^'^-''n"?  ^'^  '^^^^« 
the  marks  of  the  brush  and  to  Zlo  tl  r     ^^^^..^^^l  tm-dip  is  useful  to  remove 

temperature  of  the  allow-^t  Ind^Lf.  •  "'^^l'  Tf"^}^  ^'''^^''  ^o  regulate  the 
great  skill  and  circSnspLS  on  thrn«rf.^^^^  ^^^If  ^'^  ^^"  ^^  it,  requires 

would  be  deprived,  t^a^  certain  exten?  of  1  ^^^  ^°^^°^f "'  ^^  kept  in  it  too  long,  they 
Of  tin  would  disfigure  their  surface  V/^th-  f''^^  ^"'''^.'  ^'^^  '^  ^^  '^""''^  '^'^^^ 
lifted  out  of  the  washina  pot  Tream-rp^  «  *^^*^^  P^^^^/^tains  more  heat  after  being 
has  pins  fixed  within  it!  to  keenX  nl„^.P'''P°?^"^"^^°*'^^^  grease-pot.  This  p?t 
transferred  five  plates  to  i  a  W^iftsthlT.^'"''^^^  and  whenever  the  workman  has 
soon  as  the  wofkmTntransfe^V sixth  nl.?.  T  T  '^'  '"^^  ^^J^^*^^"'  P^°'  No.  4;^ 
The  manufacture  is  compS  by  remo^^^^^^^  boy  removes  the  second  ;  and  so  on. 

plates,  in  consequence  of  their  veS  Josh  n„  Tth  ""^  *'"  r^'  ""^  '^'  "'^^"^  "^"^  «^  '^^ 
H        c  ui  lucir  venicai  position  m  the  preceding  operations.    This  is  the 


li 


864 


TIN-PLATE. 


TOBACCO. 


86f 


litiiifi 


business  of  the  list-hoy,  who  seizes  the  plates  when  they  are  cool  enough  to  handle,  and 
puts  the  lower  edge  of  each,  one  by  one,  into  the  list-pot,  No.  5,  which  contains  a  very 
little  melted  tin,  not  exceeding  a  quarter  of  an  inch  in  depth.  When  he  observes  the 
wire-edge  to  be  melted,  he  takes  out  the  plate,  and,  striking  it  smartly  with  a  thin  stick, 
detaches  the  superfluous  metal,  which  leaves  merely  a  faint  stripe  where  it  lay.  This 
mark  may  be  perceived  on  every  tin-plate  in  the  market. 

The  plates  are  finally  prepared  for  packing  up  in  their  boxes,  by  being  well  cleansed 
from  the  tallow,  by  friction  with  bran. 

Mr.  Thomas  Morgan  obtained  a  patent,  in  September,  1829,  for  clearing  the  sheet-iron 
plates  with  dilute  sulphuric  acid  in  a  hole,  instead  of  scaling  them  in  the  usual  way,  pre- 
vious to  their  being  cold  rolled,  annealed,  and  tinned ;  whereby,  he  says,  a  better  article 
is  produced  at  a  cheaper  rate. 

Crystallized  tin-plate,  see  Moiree  Metallique.  It  would  seem  that  the  acid  merely 
lays  bare  the  crystalline  structure  really  present  on  every  sheet,  but  masked  by  a  film  of 
redundant  tin.  Though  this  showy  article  has  become  of  late  years  vulgarized  by  its 
dieapness,  it  is  still  interesting  in  the  eyes  of  the  practical  chemist.  The  English  tin- 
f^tes  marked  f  answer  well  for  producing  the  Moiree,  by  the  following  process.  Place 
tke  tin-plate,  slightly  heated,  over  a  tub  of  water,  and  rub  its  surface  with  a  sponge 
dipped  in  a  liquor  ccnnposed  of  four  parts  of  aquafortis,  and  two  of  distilled  water, 
holding  one  part  of  common  salt  or  sal  ammoniac  in  solution.  Whenever  the  crystal- 
lint  ipangles  seem  to  be  thoroughly  brought  out,  the  plate  must  be  inunersed  in  water, 
washed  either  with  a  feather  or  a  little  cotton  (taking  care  not  to  rub  off"  the  film  of  tm 
Chat  forms  the  feathering),  forthwith  dried  with  a  low  heat,  and  coated  with  a  lacker 
varnish,  otherwise  it  loses  its  lustre  in  the  air.  If  the  whole  surface  is  not  plunged  at 
once  in  cold  water,  but  if  it  be  partially  cooled  by  sprinkling  water  on  it,  the  crystalli- 
zation will  be  finely  variegated  with  large  and  small  figures.  Similar  results  will  be 
obtained  by  blowing  cold  air  through  a  pipe  on  the  tinned  surface,  while  it  is  just  passing 
frcHu  the  fused  to  the  solid  state;  or  a  variety  of  delineations  may  be  traced,  by  playing 
over  the  surface  of  the  plate  with  the  pointed  flame  of  a  blowpipe. 

The  following  Table  shows  the  several  sizes  of  tin-plates,  the  marks  by  which  they  are 
distinguished,  and  their  current  wholesale  prices  in  London :  — 


Names. 

Sizes. 

No.  in 
a  box 

Weight  of 
each  box. 

Marks  on 
the  boxes. 

Prices  per  box,  in       1 

1823. 

1838. 

Inches. 

cwt. 

qrs.  lbs. 

a. 

9.  d. 

Common,  No.  1 

13|  by  10 

226 

1 

0     0 

CI. 

47 

35 

Ditto           2      - 

I3i--   9i 

. 

0 

3  21 

CII. 

45 

33  6 

Ditto           3 

121—   9i 

- 

0 

3  16 

cm. 

43 

32  9 

Cross,       No.  1 

131—10 

. 

1 

1     0 

XI. 

53 

40  2 

Two  crosses,    1 

- 

. 

1 

1  21 

XXI. 

58 

43  2 

Three  crosses,  1 

. 

1 

2  14 

XXX.  I. 

63 

47 

Four  crosses,  1 

. 

. 

1 

3    7 

XXXX.  I. 

Common  doubles    - 

16J  — 12| 

100 

0 

3  21 

CD. 

64-61     .50 

48  6 

Cross  doubles 

. 

. 

1 

0  14 

X7^. 

73-6 

sheets 

66 

Two  cross  do. 

. 

. 

1 

1     7 

XXD. 

81 

> 
m 

60  6 

Three  cross  do. 

. 

. 

1 

2    0 

XXXD. 

sjuej 

each. 

66 

Four  cross  do. 

. 

. 

1 

2  21 

XXXXD. 

Com.  small  doubles  - 

6—11 

200 

1 

2    0 

CSD. 

69                    51  6 

Cross  do.      do.     - 

. 

«• 

1 

2  21 

XSD. 

75                    56  0 

Two  cross     do. 

. 

. 

1 

3  14 

XXSD. 

80 

59  6 

Three  do.       do. 

. 

• 

2 

0    7 

XXXSD. 

Four   do.       do.     - 

_ 

_ 

2 

1    0 

XXXX80. 

/ 

Waster's  com.  No.  1 

3f— 10 

225 

1 

0    0 

WCI. 

44 

32  9 

Ditto    cross,        1 

ditto 

- 

1 

1     0 

WXI. 

50 

47  3 

These  are  the  cash  prices  of  one  wholesale  warehouse  in  Thames  street ;  an  imme- 
diately adjoining  warehouse  charges  fully  Is.  more  upon  the  standard  ci,  and  propor- 
tionally upon  othera 

Tin  plate  working  in  the  Exhibition.  Jackson,  W.,  Birmingham,  manufacturer.  Anvil 
for  planishing  tin  plate.  Hammers  assorted  for  tin  and  copper  work.  Crease-iron 
or  wireing  stake  for  tin.  General  swage  to  hold  diflferent  tools,  for  beading  tin.  Bick- 
iron  for  tin  plate,  and  side  stake  for  tin  or  copper  work.  Bottom  stake,  for  planishing 
copper.  Pair  of  stock  shears  and  hand  shears  for  cutting  tin,'  copper,  Ac  Model  of 
a  raising  machine  for  raising  dish  covers,  \\  inch  in  scale. 


oi^Zt  td  tCh  .r''  -^"'M  P'^^'  "^^^^^  '''  enumerated  in  the  above  colleetio. 
eL^n  su^?8eded  th!  n/r'''"C ^J  "'r'?'  ^?  "spinning"  and  stamping  has  Uy  a  great 
bSk  ronTith  th.tVi''  ""^^°^'  f  V""^  ^^'•^^"^'  ^^«  P^J'^»»«d  «nvil  stakes  or 
y^  he  dispentd  Witt  7^^^^^^  plan.sh.ng-faced  hammers  of  various  forms,  cannot 
Avoided  Sni.minJ^n  !  ^\^  n«w  mode  of  production  seam-soldering  is  entirely 
w^U.  densen^erof  ix^  M  '^n^'"^'  ^9^''^^^''^^'  ^'^'^  «^  firmness  and  solid!^ 

I^-ticles    to  effecf  fh'uW  ^^^"^^^/"g  'V^*'^  necessary  in  the  manufacture  of  certain 

TOBACCO.     It  IS  said  that  the  name  tobacco  was  ^iven  by  the  SnaniardsVo  ihl  l^l* 
because  it  was  first  observed  by  them  at  Tabasrn  or  T«KL-^i  o    ^P^P^*™^^*'*^  ^^^^^ 

«ml   „„  ,,k  return  i„,o  France,' ,o  Catherine  orMXisrtent'i  "has  b^en  S 
plant  was  cultivated  in  Britain  before  the  rear  loTO  •  «nH  ^^1  ^^^^^"^'"f  }^  ^-^^el,  this 

covered  up,  and  left  to  swLt  forTweek  orT«4  aceord^ni"  o  Z"'''  'I"'"'*^  Z^''^ 
of  the  season;  durins  which  time  thev  n,„  J  k'«  1        •^j^'*'^''^ ''''''''>'  '"^  'he  state 

^"hrpro-^S  t^^^-B  Si  \S  "~-  pSSelt.^ 

d^riro^rhLr^"''-"--^^^^^ 

kZ^I  l"^^"'  M  "?  V"P^'^'  <"■ ""«"  Without  fermentation,  is  sent  into  the  market  ■  but 

q::^u\^:^x^  fft^^L^itTst^^r  ""'"■'  ='"  '""•™''""'  "-•>  •"»- '«« 

thev  nr!;?ifp'','°'ll''  '.''''■"=<=<'"'^'?  "'e  very  careful  to  separate  all  the  damaged  leaves,  before 
^t^Z,  wafer  nt'LTch";:'"'™'  "'■''" ."'^y  <*»  byspreading  them  in  a  heap  upon'asto« 
l«vcracnt,\vaicung  each  layer  in  succession  with  a  solution  ofsea  salt,  of  soec  .rav  I-im 

1^„!.  n    .u  .    '  '  ^""f"!'"?  to  the  temperature,  and  the  nature  of  the  tobacco    It  is  hi^hw 

rttw':  atrk'if  af  T'""'"?  r?""  ""^"^  odors,  anV^^p^^Mlyof'^l^ 
«mi.<  m„r^l!. ..     ,i  ^'^^''  Si^een  leaf  of  tobacco  be  crushed  between  the  fin^ersTtt 

^cutiarodorofnuH-     itva„',l"!f  "^"T  •""*'"'"  "'»  ™'»«liately  exhale  thj 

.rSuc:rabuXnce%?amm^^^  "-^"^'^^^  principle,  which  by  fermentai^n 

chiefly  in  mode  'tint  the  ?prml  t  .'     '  ^^«  5>dorous  principles.     The  salt  water  is  useful 
factive  srni^    Tus   a',   nft  [ff  ""'?^'°"'  ^"f  preventing  it  from  passing  into  the  putre- 
rtemne    rheVeimenta  iv^  n  sometirnes  added  to  saccharine  worts  in  tropical  countries, 
l^ns  some  Ll^P^^^^^^^^^^^^  .  ?'  ''V''^^'  «^  concentrated  sea  water,  which  con! 

tTpure  chlodSe  of  sod  i^^^^^^^  '^  ^''^  the  tobacco  moist,  and  is  therefore  preferable 
salt  LLf  ^d  L/rih.  n^h  ^V?.?"'PT^-  ^'""^  tobacconists  mix  molasses  with  the 
salt  sauce,  and  ascribe  to  this  addition  the  violet  color  of  the  macouba  snuff  of  Mar! 


866 


TOBACCO. 


tiniqiie ;  and  others  add  a  solution  of  extract  of  liquorice.  Tlie  following  prescription  » 
that  used  by  a  skilful  niaiiufacturei:--In  a  solution  of  the  liquorice  juice  a  few  figs  are 
to  be  boiled  for  a  couple  of  hours ;  lo  the  decoction,  while  hot,  a  few  bruised  anise-seeds 
mre  to  be  added,  and  when  cold,  common  salt  to  saturation.  A  little  silent  spirit  of  wine 
being  poured  m,  the  mixture  is  lo  be  equably,  but  sparingly,  sprinkled  with  the  rose  of 
a  watering-pot,  over  the  leaves  of  the  tobacco,  as  they  are  successively  stratified  upon  the 
preparation  floor.  * 

The  fermented  leaves,  bein?  next  stripped  of  their  middle  ribs  bv  the  hands  of  chil- 
dren, are  sorted  anew,  and  the  larjje  ones  are  set  apart  for  making  cisars.  Mo^t  of  the 
tobaccos  on  sale  in  our  shops  are  mixtures  of  different  growths:  one  kind  of  smokin«' 
tobacco,  for  example,  consists  of  70  parts  of  Maryland,  and  30  of  meager  Virginia ;  and 
one  kind  of  snufl  consists  of  80  parts  of  Virginia,  and  30  parts  of  either  Humesfort  or 
Warwick.  The  Maryland  is  a  very  light  tobacco,  in  thin  yellow  leaves;  that  of  Vir- 
ginia IS  m  large  brown  leaves,  unctuous  or  somewhat  gluey  on  the  surface,  having  a 
smell  somewhat  like  the  figs  of  Malaga ;  thai  of  Havana  is  in  brownish,  light  leaves, 
of  an  agreeable  and  rather  spicy  smell ;  it  forms  the  best  cigars.  The  Carolina  tobacco 
IS  less  unctuous  than  the  Virginian ;  but  in  the  United  States  it  ranks  next  to  the 
Maryland. 

The  shag  tobacco  is  dried  to  the  proper  point  upon  sheets  of  copper. 

Tobacco  is  cut  into  what  is  called  sha?  tobacco  by  knife-edged  chopping  stamps,  a  ma- 
chine somewhat  similar  to  that  represented  under  METALLURGY,y^g.  670.^  For  grinding 
the  tobacco  leaves  into  snuff,  conical  mortars  are  employed,  somewhat  like  that  used  by  the 
Hindoos  for  grinding  sugar-canes,  fig.  1080;  but  the  sides  of  the  snuff-mill  have  sharp 
ndifes  from  the  top  to  near  the  bottom. 

J^u  1^'  ^*  ^"^^^  obtained  a  patent  in  August,  1827,  for  a  tobacco-cutting  machine, 
which  bears  a  close  resemblance  to  the  well-known  machines  with  revolving  knives,  for 
cutting  straw  into  chaff.  The  tobacco,  after  being  squeezed  into  cakes,  is  placed  upon  a 
smooth  bed  within  a  horizontal  trough,  and  pressed  by  a  follower  and  screws  to  keep  it 
compact.  These  cakes  are  progressively  advanced  upon  the  bed,  or  fed  in,  to  meet  the 
revolving  blades.  The  speed  of  the  feeding-screw  determines  the  degree  of  fineness  of  the 
sections  or  particles  into  which  the  tobacco  is  cut. 

I  was  employed  some  years  ago  by  the  Excise  lo  analyze  a  quantity  of  snuff  seized 
on  suspicion  of  having  been  adulterated  by  the  manufacturer.  I  found  it  to  be  largely 
drugged  witli  pearl  ashes,  and  lo  be  thereby  rendered  very  punsent,  and  absorbent  of 
moisture  ;  an  economical  method  of  rendering  an  effete  article  at  the  same  time  active  aad 
aqueous. 

According  to  the  recent  analysis  of  Possett  and  Reimann,  10,000  parts  of  tobacco. 
leaves  contain  —  6  of  the  peculiar  chemical  principle  nicotine ;  1.  of  nicotianine ;  287  of 
llightly  bitter  extractive;  174  of  gum,  mixed  with  a  little  malic  acid;  26-7  of  a  green 
resin ;  26  of  vegetable  albumen ;  104-8  of  a  substance  analogous  to  gluten ;  51  of 
malic  acid;  12  of  malate  of  ammonia;  4*8  of  sulphate  of  potassa;  6*8  of  chloride  of 
potassium;  95  of  potassa,  which  had  been  combined  with  malic  and  nitric  acids* 
16-6  of  phosphate  of  lime;  24-2  of  lime,  which  had  been  combined  with  malic  acid; 
8-8  of  sihca;  496.9  of  fibrous  or  ligneous  matter;  traces  of  starch;  and  8828  of  water' 

Nicotine  is  a  transparent  colorless  liquid,  of  an  alkaline  nature.  It  may  be  dis- 
tilled ma  retort  plunged  into  a  bath  heated  to  290°  Fahr.  It  has  a  pricking,  burninff 
taste,  which  is  very  durable ;  and  a  pungent  disagreeable  smell.  It  burns  by  means  of 
a  wiek,  with  the  diffusion  of  a  vivid  light,  and  much  smoke.  It  may  be  mixed  with 
water  in  all  proportions.  It  is  soluble  also  in  acetic  acid,  oil  of  almonds,  alcohol  and 
etfier,  but  not  in  oil  of  turpentine.  It  acts  upon  the  animal  economy  with  extreme 
violence;  and  in  the  dose  of  one  drop  it  kills  a  dog.  It  forms  salts  with  the  acids. 
About  one  part  of  it  may  be  obtained  by  very  skilful  treatment  from  one  thousand  of 
good  tobacco. 

Virginia  leaf  costs  in  bond  ^d.  per  lb.,  the  duty  is  1,100  per  cent 
Ditlo  strips  "  5\d.  "  700        " 


Ditto  strips 
Kentucky  leaf 
Ditto  strips 
Havanna  cigars 
Manilla  cheroots 
East  India  cheroots 


5; 

sU 

8*. 
G«. 
If. 


Negrohead  and  Cavendish  6d. 
Bates  of  duty  on  tobacco  in  foreign  countries:— 


700 
1,200 
800 
112 
150 
900 
1,800 


<« 

M 
« 


Austria— leaf  tobacco 

Belgium       ditto       ... 

Bremen        ditto,  ^  per  cent,  ad  valorem 

Denmark  leaves  and  stems 

Prussia 

Saxuny 

Bavaria  j  Zoll-Verein) 

Brunswick  )      States.     ) 

Wirtemberg 

Frankfort  on  the  Maine 


Per  EiiKliab 

Pound. 
•       3d. 
-       id. 


2d 


Tn  Englisk 
Pound. 


Other  German  States 
Hamburgh        §  per  cent,  ad  valorem. 
Holland  2  per  cent,  ad  valorem. 

Ditto,  cigars  .... 

Ionian  islands,  leaf  stems 

Ditto  manufactured 

Rassia  30  per  cent,  ad  valorem 

on  foreign. 
Sweden  imd  Norway  -  about  IdL 


2dL 

Sd 


TOBACCO-PIPES. 


867 


A  f^tnet  royal  monoply  {r^gie)  exists  in  Austria  Proper,  France,  Sardinia,  the  Duchies 
of  1  at-ma  and  Lucca,  and  the  Grand  Duchy  of  Tuscany ;  and  in  Portugal,  Spain,  Naples, 
and  the  States  of  the  Church,  the  license  to  manufacture  is  periodically  sold  to  com- 
panies, which  regulate  the  price  of  tobacco  as  they  please.  It  will  be  found  that  the 
situation  of  all  these  countries  where  the  monopolies  and  high  prices  are  kept  up,  is 
neariy  the  same,  as  to  illicit  trade  in  tobacco,  as  in  England.  No  measure  short  of  a 
reduction  of  the  duty  to  U.  per  lb.  can  put  a  stop  to  it 

The  following  analysis  of  10,000  parts  of  fresh  tobacco,  by  Posselt  and  Reimann.  will 
show  the  exceeding  complexity  of  this  substance : — 


Nicotine        .  .  .  . 

Nicotianine  -  .  .  . 

Extractive  matter,  slightly  bitter 
Oum  with  a  little  malate  of  lime 
Oreen  resin  ... 

Vegetable  albumen 
Substances  analogous  to  gluten  - 
Malic  acid    .... 
Malate  of  ammonia 
Sulphate  of  potash 


6 
1 
287 
174 
26-7 
260 
104-8 
510 
120 
4-8 


Chloride  of  potassium  -  -  . 

Potash  combined  with  melic  and  nitric  acids 
Phosphate  of  lime         -      ••    . 
Lime  in  union  with  malic  acid 
Silica        ..... 
Woody  fibre 


Water  (traces  of  starch) 


6-3 

95 

16C 

24-2 

88 

496-9 


-     8,828-0 


10,000-0 


In  Silliman's  Journal,  vol.  vii.  p.  2,  a  chemicnl  examination  of  tobacco  is  given  by  Dr 
Covell,  which  shows  its  components  to  have  been  but  imperfectly  represented  in  the 
above  Gerinan  analysis.     He  found,  1,  gum ;  2,  a  viscid  slime,  equally  soluble  in  water 
and  alcohol,  and  perceptible  from  both  by  subacctate  of  lead  ;  3,  tannin-  4  gallic  acid- 
5,  chlorophyle  (leaf-green);  6,  a  green  pulverulent  matter,  which  dissolves  in  boiling 
water,  but  falls  down  again  when  the  water  cools;  7,  a  yellow  oil,  possessing  the  smell 
taste,  and  poisonous  qualities  of  tobacco;  8,  a  large  quantitv  of  a  pale  yellow  resin- 
9,  nicotine;  10,  a  white  substance,  analogous  to  morphia,  soluble  in  hot,  but  hardly 
m  cold,  alcohol ;    11,  a  beautiful  orange-red  dye  stuff,  soluble  only  in  acids:  it  defla- 
CTates  in  the  fire,  and  seems  to  possess  neutral  properties;  12,  nicotianine.    In  the 
infusion  and  decoction  of  the  leaves  of  tobacco,  little  of  this  substance  is  found  -  but 
after  they  are  exhausted  with  ether,  alcohol,  and  water,  if  they  be  treated  with  sul- 
phuric acid,  and  evaporated  near  to  dryness,  crystals  of  sulphate  of  nicotianine  are  ob- 
tamed.     Ammonia  precipitates  the  nicotianine  from  the  solution  in  the  state  of  a  yel- 
lowish white,  mit  powdering  r«atter,  which  may  be  kneaded  into  a  lump,  and  is  void 
Of  taste  and  smell,  as  all  its  neutral  saline  combinations  also  are:  its  most  characteristic 
fd/a^       ^*  forming  soluble  and  uncrystallisable  compounds  with  vegeUble 

According  to  Buchner,  the  seeds  of  tobacco  yield  a  pale  yellow  extract  to  alcohol 
which  contains  a  compound  of  nicotine  and  sugar.     Kepertorium  fur  die  Pharmacil 

MM.  Henry  and  Boutron  Charlard  found  in 
1000  parts  of  Cuba  tobacco 
Maryland    - 
Virginia 
He  et  Vilaine 
Lot  et  Garonne 
more  than  were  obtained  by  Posselt  and  Reimann. 

1  *,*l^J'^*""^'^®  of  tobacco  retained  for  home  consumption  in  1842,  amounted  to 
nearly  17,000,000  pounds.  Professor  Schleiden  gives  a  sfngular  illustratTon  of  the 
iroclS^OOOntr^r^^ri!^-  North  America  alone  produces  annually  upwards  of 
200,000,000  of  pounds  of  tobacco.  The  combustion  of  this  mass  of  vegeteble  material 
would  yield  about  840,000,000  pounds  of  carbonic  acid  gas,  so  that  thf  yearly  produce 

foSSoooooo';:^,^'.''^'T  ^b««««T"^^"S  alone,  canlot  be  estimat^  atiL  than 
ino^fb.  '«f  P  I  "^'i  \l"^^^  contribution  to  the  annual  demand  for  this  gas  made 
upon  the  atmosphere  by  the  vegetation  of  the  worid.  ^ 

SfiTfifi^'S  'ihf^'^-^  il^?/^o^,  .^?^^"^  Kingdom,  viz.: -unmanufactured,  in  1850. 
ffiJ?M«lJ  •'  ,'?«i^o\\,^^'^^  '^^^  lbs.; -manufactured,  and  snu^  in  1850 
tSYn  18.o' 9?  ?«\'n!'^K^'^''  ^^'-  ^^'^'"^^  f^^  ^^"'^  consumption,  unmanufael 
S'i?A  A«i  'iK  '^^^'loti^ol'"  ^^?^'  27,863.390  lbs.  ;-manufactured,  and  snuff,  in 
in  1 85^  4  33J  2.8/'  '"in  1  «^.'iT^/A\'^n^  ^"'^  receiTed,-on  unmanufactured  tobacco! 
92,8?3?;;1'nT851 '9^.858^'^'  '''''''''' '  ^°  "«-^««tured  (.bacco.  and  snuff,  in  1850.' 

nia^^ntt^nn^;ri^^-  7»^^J>^««tice  of  smoking  tobacco  has  become  so  general  in 
Strv  Snr?.^  T^V^.  the  manufacture  of  tobacco-pipes  a  considerable  branch  of 
WJnTW  f.  K   K      «  "•  ^w  ^"f^^on  of  tobacco-smoke  a  p'leasurable  narcotism ;  others 

^ZrZ  inW  '""'^''^^  *^'t'''•  ^'".^^^ '  ^""^  ^°  general,  smoking  is  merely  a  dreamy 
resource  against  ennui,  which  ere  long  becomes  an  indispen^ble  stimulus.    The 


8*64  of  nicotine; 

6-28 
10-00 
11-20 

8-20 ;  quantities  from  12  to  19  times 


Hi 


i  I  i 


868 


TOBACCO-PIPES. 


iiih!! 


filthiness  of  this  habit,  the  offensive  odor  which  persons  under  its  influence  emit  from  their 
mouths  and  clothes,  the  stupor  it  too  often  occasions,  as  well  as  the  sallow  complexion, 
black  or  carious  teeth,  and  impaired  digestion,  all  prove  the  great  consumption  of  tobacco 
to  be  akin  in  evil  influence  upon  mankind  to  the  use  of  ardent  spirits. 

Tobacco-pipes  are  made  of  a  fine-grained  plastic  white  clay,  to  which  they  have  given 
the  name.  It  is  worked  with  water  into  a  thin  paste,  which  is  allowed  to  settle  in  pits, 
or  it  may  be  passed  through  a  sieve,  to  separate  the  silicious  or  other  stony  impurities ; 
the  water  is  afterwards  evaporated  till  the  clay  becomes  of  a  doughy  consistence,  when 
it  must  be  well  kneaded  to  make  it  uniform.  Pipe-clay  is  found  chiefly  in  the  isle  of 
Purbeck  and  Dorsetshire.  It  is  distinguished  by  its  perfectly  white  color,  and  its  great 
adhesion  to  the  tongue  after  it  is  baked;  owing  to  the  large  proportion  of  alumina  which 
it  contains. 

A  child  fashions  a  ball  of  clay  from  the  heap,  rolls  it  out  into  a  slender  cylinder  upon 
a  plank,  with  the  palms  of  his  hands,  in  order  to  form  the  stem  of  the  pipe.  He  sticks 
a  small  lump  to  the  end  of  the  cylinder  for  forming  the  bowl ;  which  having  done,  he 
lays  the  pieces  aside  for  a  day  or  two,  to  get  more  consistence.  In  proportion  as  he 
makes  these  rough  figures,  he  arranges  them  by  dozens  on  a  board,  and  hands  them  to  the 
pipemaker. 

The  pipe  is  finished  by  means  of  a  folding  brass  or  iron  mould,  channelled  inside  of  the 
shape  of  the  stem  and  the  bowl,  and  capable  of  being  opened  at  the  two  ends.  It  is  formed 
of  two  pieces,  each  hollowed  out  like  a  half-pipe,  cut  as  it  were  lengthwise  ;  and  these  two 
jaws,  when  brought  together,  constitute  the  exact  space  for  making  one  pipe.  There  are 
small  pins  in  one  sidfi  of  the  mould,  corresponding  to  holes  in  the  other,  which  serve  as  guides 
for  applying  the  two  together  with  precision. 

The  workman  takes  a  long  iron  wire,  with  its  end  oiled,  and  pushes  it  through  the 
soft  clay  in  the  direction  of  the  stem,  to  form  the  bore,  and  he  directs  the  wire  by  feeling 
with  his  left  hand  the  progress  of  its  point.  He  lays  the  pipe  in  the  groove  of  one  of 
the  jaws  of  the  mould,  with  the  wire  sticking  in  it ;  applies  the  other  jaw,  brings  them 
smartly  together,  and  unites  them  by  a  clamp  or  vice,  which  produces  the  external 
form.  A  lever  is  now  brought  down,  which  presses  an  oiled  stopper  into  the  bowl  of 
the  pipe,  while  it  is  in  the  mould,  forcing  it  sufficiently  down  to  form  the  cavity ;  the 
wire  being  meanwhile  thrust  backwards  and  forwards  so  as  to  pierce  the  tube  completely 
through.  The  wire  must  become  visible  at  the  bottom  of  the  bowl,  otherwise  the  pipe 
will  be  imperfect.  The  wire  is  now  withdrawn,  the  jaws  of  the  mould  opened,  the  pipe 
taken  out,  and  the  redundant  clay  removed  with  a  knife.  After  drying  for  a  day  or 
two,  the  pipes  are  scraped,  polished  with  a  piece  of  hard  wood,  and  the  stems  being  b-nt 
into  the  desired  form,  they  are  carried  to  the  baking  kiln,  wnich  is  cfipaWe  of  firing  f.fty 
gross  in  from  8  to  12  hours.  A  workman  and  a  child  can  easily  make  five  gross  of  pipes 
in  a  day. 

No  tobacco-pipes  are  so  highly  prized  as  those  made  in  Natolia,  in  Turkey,  out  of 

meerschaum,  a  somewhat  plastic  magnesian  stone,  of  a  soft  greasy  feel,  which  is  formed 

into  pipes  after  having  been  softened  with  water.     It  becomes  white  and  hard  in  the  kiln 

A  tobacco-pipe  kiln  should  diffuse  an  equal  heat  tc  every  part  of  its  interior,  while 

it  excludes  the  smoke  of  the  fire.     The  crucible,  or  large  sagger,  a,  a,  figs.  1473  and 

1474,  is  a  cylinder,  covered  in  with  a  dome.  It  is  placed 
over  the  fireplace  b,  and  enclosed  within  a  furnace  of  ordinary 
brickwork  d,  d,  lined  with  fire-bricks  e,  e.  Between  this  lining 
and  the  cylinder,  a  space  of  about  4  inches  all  round  is  left 
for  the  circulation  of  the  flame.  There  are  12  supports  or 
ribs  between  the  cylinder  and  the  furnace  lining,  which  form 
so  many  flues,  indicated  by  the  dotted  lines  a*,  in  Jig.  1474 
(the  dotted  circle  representing  the  cylinder).  These  ribs  are 
perforated  with  occasional  apertures,  as  shown  in  Jig.  1473, 
for  the  purpose  of  connecting  the  adjoining  flues  ;  but  the  main 


1474 


bearing  of  the  hollow  cylinder  is  given 
by  five  piers,  6,  b,  c,  formed  of  bricks 
projecting  over  and  beyond  each  other. 
One  of  these  piers  c,  is  placed  at  the 
back  uf  the  fireplace,  and  the  other  four 
at  the  sides  b,  b.  These  project  nearly 
into  the  centre,  in  order  to  support  and 
strengthen  the  bottom ;  while  the  flues 
pass  up  between  them,  unite  at  the  top 
of  the  cylinder  in  the  dome  l,  and  dis- 
charge the  smoke  by  the  chimney  n. 


The 


lining 


F,  E,  E,  of  the  chimney  is 


TOOTH  FACTORY. 

•Den  on  one  side  to  form  the  door,  by  which  the  cylinder  is  charged  and  discharged, 
^h  ZT^  «  permanently  closed  as  high  as  k,  /g.  1473.  by  an  iron  plate  plastered 
3hltTpr^'  ^^"^^  ^-^''"  '^^^^  open,  and  shut  merely  with  temporary  brick-work 
tTrnll  rh  ''''*''^''  ^T^'    y^^^""  ^^^^  i^  removed,  the  furnace  can  be  filled  or  emptied 
whTa  ?«    I    T"*"l'  '^^  cyhndric  crucible  having  a  correspondent  aperture  in  its  side, 
wo  kman  fi?f  '"  ^^'  ^?"°^^"p  ^"^^'^'^"^  ^^^^  "^^^^  '^^  ^^^uace  is  in  action.     The 
^em,  nf  w?  '^''^-    '  *  ^^^^'f  ""^^^  '*°"'*^  '^^  ^^?«  °^  ^^^  opening,  he  then  sticks  the 
wffh  Hw  Iv    M  ^,T'  across  from  one  side  to  the  other,  and  plasters  up  the  interstices 
with  clay,  exactly  like  the  lath-and-plaster  work  of  a  ceiling.    The  whole  of  the  cylinder, 
indeed,  is  constructed   in  this  manner,  the  bottom  being  composed  of  a  great  many 
w?rh"!ffM      ^r^^  ''^™?'  radiating  to  the  centre;  these  are  coated  at  the  circumference 
7hlt    ly^'"  ?^<^^ay-    A  number  of  bowls  of  broken  pipes  are  inserted  in  the  clav:  in 
r«.?n!i  ?K        f'-a^ments  are  placed  upright,  to  form  the  sides  of  the  cylinder.     The  ribs 
r.  Kv  'i^°"^^''^^'  ^'"/=»^  ^o™  the  flues,  are  made  in  the  same  way,  as  well  as  the  dome 
iJnnlZl'^r  T'"''-^  !u^  J^V"^"*^  ^^^^  T^  b^  "^ade  very  strong,  and  yet  so  thin  as  to 
a!^n  P.     T.  ^^  ""  ^^^  ^'"''^'"'^  *  "^^^^'^^^  fi'-e  to  heat  it,  while  it  is  not  apt  to  spUt 
?„r,c  ••    .Tk^  ^'P^'  ^/^  arranged  within,  as  shown  in  the  figure,  with  their  bowls  rest- 
ing agamst  the  circumference,  and  their  ends  supported  on  circular  pieces  of  clay  r,  which 
^ln^\u^  '"  ^''m  ^'^""■t  ^""^  ^^*'  purpose.     Six  small  ribs  are  made  to  project  inwards  all 
round  the  crucible,  at  the  proper  heights,  to  support  the  different  ranges  of  pipes,  withou 
navmg  so  many  resting  on  each  other  as  to  endanger  their  being  crushed  by  the  weight. 

withii'sTr  q  Innr'^'TT'  u"'  ^"'"^T  V^  ^^"^^''^  ^^  ^'^''^  ^'  ^^^O  pipes,  all  baked 
r»r.l«n!  T  ?  !e  ^^t-^'^  ^^'"^  gradually  raised,  or  damped  if  occasion  be,  by  a  plate 
partially  slid  over  the  chimney  top.  >    /  "  I'^^^c 

TODDY,  Sura,  3fee.ru,  sweet  juice.— The  proprietors  of  cocoa-nut  plantations  m 
the  peninsula  of  India,  and  in  the  Island  of  Ceylon,  instead  of  collecting  a  crop  of  nuS 
stalk'  Wh^'^h^'!?  produce  of  the  trees  by  extracting  sweet  juice  from  the  flowed 
w?fh  o  flowering  branch  is  half  shot,  the  toddy-drawers  bind  the  stock  round 

With  a  yming  cocoa-nut  leaf  in  several  places,  and  heat  the  spadix  with  a  short  baton  of 

S-a  ^o^^o^^fheT^^^^^     ^ff^  '\^:^s.::i:^-:\^^  tt::i 

rjy  thVE^^pltTc^^^^      l^-"  '-  -'^-'^  -^-  '>  ^^  --^-  ^^^i"^->  w^ieS 

A  tlt''j!!''r  ''  ^^^f "  ^T  '^^  '^"""P  ^^'^y*  ^"'^  *^«  to^'Jy  «  removed  twice  a  day. 
h^.  „?  ;  K.  ^'"J'^Vf^tly  Pushes  out  a  new  spadix  once  a  month;  and  after  each  spadS 
t^^ns  to  bleed.  It  continues  to  produce  freely  for  a  month,  b^  which  time  another  S 
ready  to  supply  its  place.  The  old  spadix  continues  to  give  a  little  juice  for  another 
ft  ^„^.^i!'^''^'^  ''  "'^"*'''^'  i^^  ^^^'  '^-'^  ^"-^  sometimes  two  pots  attached  to  a  tr^ 

dnce  .Z'  K  f""''.  T'"-  ^^'^  "^  ^^'""'^  'P^^'*^^^'  '^  *"«^^  t«  ^row,  would  pro- 
duce a   bunch  of  nuts  from  two  to  twenty.     Trees  in  a  good  soil  produce  twelve 

thr.fvK"  '\'y'^'^,^^'  ^^^!»  ^r  ^""^^'^^^y  situated,  they%ften  do  Z  gTve  mor! 

1  tree  daUv"       '•  "^         '^  ""^  ''^  ^"^^''^  P^°''  °^  ^^^^  ^^  sometimes  yielded  b^ 

^;Ji*'*^'^^K  '^  "V"^^  '°  demand  as  a  beverage  in  the  neighborhood  of  villages,  esoe- 
Zll^Z^"""  ^^'T^^^'oops  are  stationed!  When  it  is  drunk  before  simrUe  it  is  t 
cool  delicious,  and  particularly  wholesome  beverage;  but  by  eight  or  nia^ o'clock  fe^. 
mentation  has  made  some  progress,  and  it  is  then  highly  intoxicating  % 

lULlJ,   18  a   brownish-red   balsam,    extracted   from   the  stem  of   the  Mvroxilon 
tolmferum,  a  tree  which  grows  in  South  America.      It  is  compo  ed  of  ISin    oil 
and  benzoic  acid     Having  an  agreeable  odor,  it  is  sometimes  Ssed  in  perfumery 

''^^^^:^:X^t;i^  ^-  -^-^  ^-^  --- 1  knotVoi  ^^^^"°^^^^- 

^Jo?;f  ^^1  ??^^'  !^\^''"i^  ^^  "'^  Dlpterix  odorata,  affords  a  concrete  crystalline 

tTon  tth'  a  cthTt^^^^^^^^^^^^^  ^^  ^^^  F--'--     I^  -  exTr^cfedTy  d^g^^^ 

«r.JKi.   *^^^,*'^'' 7'»<^l^  dissolves  the  stearoptene  and  leaves  a  fat  oil     It  has  an 

Sgher  llLl^'"'  ""'  "  "^^"  ^^^^     ^'  '^  '-^'^'^  -'  1220  Fahrenhef^  and  volatfle  at 

mfn^tlken^^om'Jhe^fi^  ^^^  ^«  ««^«'"^<i   by  a  moderate  heat. 

intrnimberles^  Dite^^^^^  watei.  which  breaks  it 

liut  inrr  mil?£S;.  •?   i/^^5  ^'%^^^  *^^  ^'•^^^'i  ioto  ^^a"er.  and  the  whole 
put  into  a  mm,  which  is  itself  made  of  nnnrf^     w^,.^  fu^  .,•  e     i  •     j    """•« 

arp  o-ronnrl  iin  Jnf^  fin^  ^^„A         xt    "^3  ^"2.     Here  the  pieces  of  calcined  quartz 

"p%fS'Zontio  :iT„fp„J5:f    ArtiS  lirJ™"  '"  i".p»riUe.  is  ground 
r  »  XI lie  powuer.     ArtiQciaJ  teeth  are  composed  of  two  parts, 

*  Contribution*  to  the  Hiatory  o^  the  Cocoa-nut  Tr*u»     n»  w» «     i.  n   «.        r^      ^  , 

ofHospitala.  '       "*«  V'ucua  nuc  i  ree.    By  Henry  ifarahall,  Esq.,  Deputy  Iiupector 


mM 


870 


TORTOISE-SHELL. 


TRIPOLL 


871 


called  the  body  and  enamel    The  body  of  the  tooth  is  made  firat^  the  enamel  ia  added 

*The  next  step  is  to  mix  together  nearly  equal  parts,  by  weight,  of  the  powdered 
spars  and  quartz.    This  mixture  is  again  ground  to  a  greater  fineness.     Certam  metallic 
oxides,  as  of  tin,  are  now  added  to  it,  for  the  purpose  of  producing  an  appropriate  color, 
and  water  and  china  clay  to  make  it  plastic  and  give  it  consistence.     This  mixture 
resembles  soft  paste,  which  is  transferred  to  the  hands  of  females,  who  are  engaged  m 
filling  moulds  with  it,  or  otherwise  working  upon  it    After  the  paste  has  been  moulded 
into  proper  shape,  two  small  platina  rivets  are  inserted  near  the  base  of  each  tootb,  for 
the  purpose  of  fastening  it  (by  the  dentist)  to  a  plate  in  the  mouth      They  are  now 
transferred  to  a  furnace,  where  they  are  "cured,"  as  it  is  technically  called ;  that  is,  half 
baked  or  hardened.     The  teeth  are  now  ready  to  receive  the  enamel,  which  is  done  by 
women ;  it  consists  of  spar  and  quartz  which  has  been  ground   pulverized,  and  reduced 
to  the  state  of  a  soft  paste,  which  is  evenly  spread  over  the  half  baked  body  of  the  tootb 
by  means  of  a  delicate  brush.    The  teeth  must  be  next  subjected  to  an  intense  heat. 
They  are  put  into  ovens,  lined  with  platina  and  heated  by  a  furnace,  in  which  the 
necessary  heat  is  obtained.    The  baking  process  is  superintended  by  a  workman,  who 
occasionally  removes  a  tooth  to  ascertain  whether  those  withm  have  been  sufliciently 
baked.    This  is  indicated  by  the  appearance  of  the  tooth.     When  they  are  done  the 
teeth  are  placed  in  jars  ready  for  use.     An  experiment  tests  the  hardness  of  these 
artificial  teeth.     One  of  them  taken  indiscriminately  out  from   a  jar-full  is  driven 
without  breaking  hito  a  fine  board,  until  it  is  even  with  the  surface  of  the  wood. 

TOPAZ.    See  Lapidary.  .u     v  .j 

TORTOISE-SHELL,  or  rather  scale,  a  horny  substance,  that  covers  the  hara 
strong  covering  of  a  bony  contexture,  which  encloses  the  Testudo  imbricata,  Linn.  The 
lamella  or  plates  of  this  tortoise  are  thirteen  in  number,  and  may  be  readily  separated  from 
the  bony  parts  by  placing  fire  beneath  the  shell,  whereby  they  start  asunder.  They  vary 
in  thickness  from  one  eighth  to  one  quarter  of  an  inch,  according  to  the  age  and  size  of 
the  animal,  and  weigh  from  5  to  25  pounds.  The  larger  the  animal,  the  better  is  the 
*hell.  This  substance  may  be  softened  by  the  heat  of  boiling  water ;  and  if  compressed 
in  this  state  by  screws  in  iron  or  brass  moulds,  it  may  be  bent  into  any  shape.  Ihe 
moulds  being  then  plunged  in  cold  water,  the  shell  becomes  fixed  in  the  torm  imparted 
by  the  mould.  If  the  turnings  or  filings  of  tortoise-shell  be  subjected  skilfully  to  grad- 
ually increased  compression  between  moulds  immersed  in  boihiig  water  compact 
obiect^  of  any  desired  ornamental  figure  or  device  may  be  produced.  The  soldering  of 
two  pieces  of  scale  is  easily  effected,  by  placing  their  edges  together,  after  they  are  nicely 
filed  to  one  bevel,  and  then  squeezing  them  strongly  between  the  long  flat  jaws  ot  hot 
iron  pincers,  made  somewhat  like  a  hairdresser's  curling-tongs.    The  pincei-s  should  be 


1476 


1477 


1478 


1480 


1479 


•trong,  thick,  and  just  hot  enough  to  brown  paper  slightly,  without  burning  it  They  may 
be  soldered  also  by  the  heat  of  boiling  water,  applied  along  with  skilful  pressure.  But 
in  whatever  way  this  process  is  attempted,  the  surfaces  to  be  united  should  be  made  very 
smooth,  level,  and  clean ;  the  least  foulness,  even  the  toucA  of  a  finger,  or  breathing  upoa 
them,  would  prevent  their  coalescence.    See  Horn. 

Tortoise-shell  is  manufactured  into  various  objects,  partly  by  cutting  out  the  shapes  and 
partly  by  agglutinating  portions  of  the  shell  by  heat  When  the  shell  has  become  soft 
by  dipping  it  in  hot  water,  and  the  edges  are  in  the  cleanest  possible  state  without 
grease,  they  are  pressed  together  with  hot  flat  tongs,  and  then  plunged  into  cold  water, 
to  fix  them  in  their  position.  The  teeth  of  the  larger  combs  are  parted  in  their  heated 
state,  or  cut  out  with  a  thin  frame  saw,  while  the  shell,  equal  in  size  to  two  comba^ 
with  their  teeth  interlaced,  as  in  Jig.  1475,  is  bent  like  an  arch  in  the  direction  of  the 
length  of  the  teeth,  as  in^g.  1476.  The  shell  is  then  flattened,  the  points  are  separated 
With  a  narrow  chisel  or  pricker,  aud  the  two  combs  are  finished,  while  flat,  with  coarse 
single-cut  files  and  triangular  scrapers.  They  are  finally  warmed,  and  bent  on  the  knee 
over  a  wooden  mould,  by  means  of  a  strap  passed  round  the  foot,  just  as  a  shoemaker 
fixes  his  last.  Smaller  combs  of  horn  and  tortoise-shell  are  parted,  while  flat,  by  an 
ingenious  machine,  with  two  chisel-tbrmed  cutters  placed  obliquely,  so  that  each  cut 
produces  one  tooth.  See  Rogers'  comb-cutting  machine.  Trans.  Soc.  Arts,  vol.  xlix., 
part  2,  since  improved  by  Mr.  Kelly.  In  making  the  frames  for  eye-glasses,  spec- 
tacles, &c.,  the  apertures  for  the  glasses  were  formerly  cut  out  to  the  circular  form,  with 
a  tool  something  like  a  carpenter's  centre-bit,  or  with  a  crown  saw  in  the  lathe.  The 
discs  so  cut  out  were  used  for  inlaying  in  the  tops  of  boxes,  &c.  This  required  a  piece 
of  shell  as  large  as  the  front  of  the  spectacle;  but  apiece  one  third  of  the  size  will  now 
suffice,  as  the  eyes  are  strained  or  -pulled.  A  long  narrow  piece  is  cut  out,  and  two  slits 
are  made  in  it  with  a  saw.  The  shell  is  then  warmed,  the  apertures  are  pulled  open, 
and  fastened  upon  a  taper  triblet  of  the  appropriate  shape ;  as  illustrated  by  figs.  1477, 
1478,  and  1479.  The  groove  for  the  edge  of  the  glass  is  cut  with  a  small  circular  cutter, 
or  sharp-edged  saw,  about  three  eighths  or  half  an  inch  in  diameter ;  and  the  glass  is 
sprung  in  when  the  frame  is  expanded  by  heat. 

In  making  tortoise-shell  boxes,  the  round  plate  of  shell  is  first  placed  centrally  over 
the  edge  of  the  ring,  as  in  ^g.  1480:  it  is  slightly  squeezed  with  the  small  round  edge- 
block  g,  and  the  whole  press  is  then  lowered  into  the  boiling  water :  after  immersion 
for  a'jout  half  an  hour,  it  is  transferred  to  the  bench,  and  g  is  pressed  entirely  down,  so 
as  to  bend  the  shell  into  the  shape  of  a  saucer,  as  tA^fig.  1481,  without  cutting  or  injuring 
the  material ;  and  the  press  is  then  cooled  in  a  water-trough.  The  same  processes  are 
repeated  with  the  die  rf,  which  has  a  rebate  turned  away  to  the  thickness  of  the  shell, 
and  completes  the  angle  of  the  box  to  the  section  fig.  1482,  ready  for  finishing  in  the 
lathe.  It  is  always  safer  to  perform  each  of  these  processes  at  two  successive  boilings 
•nd  coolings.  Two  thin  pieces  are  cemented  together  by  pressure  with  the  die  c,  and  a 
aevice  may  be  given  by  the  engraved  die  /. — See  HoUzapffeVs  Turning  and  Mechanical 
Manipulation,  vol.  i.,  p.  129. 

TOUCH-NEEDLES,  and  TOUCH-STONE,  are  means  of  ascertaining  the  quality  of 
gold  trinkets.     See  Assay. 

TOW.     See  Flax. 

TRAGACANTH,  gum.  (Gotmne  adracante,  Fr. ;  Traganih  Germ.)     See  Gum. 

TRAVERTINO.     See  Tufa. 

TREACLE,  is  the  viscid  brown  uncrystallizable  sirup  which  drains  fi-om  the  sugar-re- 
Ciuig  moulds.  Its  specific  gravity  is  generally  1*4,  and  it  contains  upon  an  average  75 
pc  •  cent,  of  solid  matter,  by  my  experiments. 

TRIPOLI  (Terre  pourrie,  Fr. ;  Tripel,  Germ.),  rotten-stone,  is  a  mineral  of  ao 
earthy  fracture,  a  yellowish-gray  or  white  color,  composition  impalpably  fine,  meager 
to  the  touch,  does  not  adhere  to  the  tongue,  and  burns  white.  Its  analogue,  the 
Polierschiefer,  occurs  in  thin  flat  foliated  pieces,  of  the  above  colors,  occasionally  striped ; 
soft,  absorbent  of  water;  spec.  grav.  1-9  to  2*2. 

M.  Khrenberg  has  shown  that  both  of  these  friable  homogeneous  rocks,  which  consist 
almost  entirely  of  silica,  are  actually  composed  of  the  exuviae  or  rather  the  skeletons  of 
infusoria  (animalcula)  of  the  family  of  BarcUlaria,  and  the  genera  Coeconema,  Gmphonetna, 
&c.  They  are  recognised  with  such  distinctness  in  the  microscope,  that  their  analogies 
with  living  species  may  be  readily  traced  ;  and  in  many  cases  there  are  no  appreciable 
differences  between  the  living  and  the  j)etrified.  The  species  are  distinguished  by  the 
number  of  partitions  or  transverse  lines  upon  their  bodies.  The  length  is  about  i.  of  a 
line.  M.  Ehrenberg  made  his  observations  upon  the  tripolis  of  Billen  in  Bohemia,  of 
Santafiora  in  Tuscany,  of  the  Isle  of  France,  and  of  Francisbad,  near  Eger. 

The  meadow  iron  ore  {Fer  liinoneux  des  marats)  is  composed  almost  wholly  of  the 
Gaellomlla  ferrugi/iea.  Most  of  these  infusoria  are  lacustrine ;  but  others  are  marine^ 
particularly  the  tripolis  of  tlie  Isle  of  France. 


"   ^'ift-^Mft 


872 


TUBULAR  CRANE. 


TURF. 


873 


According  to  the  chemical  analysis  of  Bucholz,  tripoli  consists  of— silica,  81 ;  alumina, 
1-6  ;  oxide  of  iron,  8;  sulphuric  acid.  3'45  ;  water,  4-55.  This  specimen  was  probably 
found  in  a  coal-field.  The  tripoli  of  Corfu  is  reckoned  the  best  for  scouring  or  brighten- 
ing brass  and  other  metals.  Mr.  Philips  found  in  the  Derbyshire  rotten-stone  (near 
Bakewell),  85  of  ahimina,  4  of  silica,  and  10  of  carbon— being  a  remarkable  diflference 
in  composition  from  the  Bohemian. 

TUBES  OF  BRASS.  Brass  or  other  tubes  are  formed  of  rolled  metal,  which  is  cut 
to  the  required  breadth  by  means  of  revolving  discs ;  in  the  large  sizes  of  tubes,  the  metal 
is  partially  curved  in  its  length  by  means  of  a  pair  of  rolls ;  when  in  this  condition  it  is 
passed  through  a  steel  hole  or  a  die,  a  plug  being  held  in  such  a  position  as  allows  the 
metal  to  pass  between  it  and  the  interior  of  the  hole.  Oil  is  used  to  lubricate  the 
metal;  the  motion  is  communicated  by  power,  the  drawing  apparatus  being  a  pair  of 
huge  nippers,  which  holds  the  brass,  and  is  attached  to  a  chain  and  revolves  round  a 
windlass  or  cylinder.  The  tube  in  its  unsoldered  state  is  annealed,  bound  round  at 
intervals  of  a  few  inches  with  iron  wire,  and  solder  and  borax  applied  along  the  seam. 
The  operation  of  soldering  is  completed  by  passing  the  tube  through  an  air  stove, 
heated  with  "cokes" or  "breezes,"  which  melts  the  solder,  and  unites  the  two  edges  of 
the  metal,  and  forms  a  perfect  tube ;  it  is  then  immersed  in  a  solution  of  sulphuric  acid, 
to  remove  scaly  deposits  on  its  surface,  the  wire  and  extra  solder  having  been 
previously  removed :  it  is  then  drawn  through  a  "finishing  hole  plate,"  when  the  tube 
18  corapdeted.  i  j 

Mandril  drawn  tubes,  as  the  name  indicates,  are  drawn  upon  a  very  accurately  turned 
steel  mandril ;  by  this  means  the  internal  diameter  is  rendered  smooth  ;  the  tube  formed 
by  this  process  is  well  fitted  for  telescopes,  syringes,  small  pump-cvlinders,  Ac. 

Brass  solder  is  composed  of  almost  equal  quantities  of  copper  and  zinc;  its  properties 
should  be  that  of  melting  at  such  a  temperature  as  will  allow  the  article  to  be  soldered 
to  be  sufficiently  heated,  but  yet  some  degrees  from  the  melting  point.  Solder  is  al- 
ways used  in  connection  with  borax,  the  cleansing  properties  of  which  appear  to  laeili- 

tate  the  fusion  of  the  metal. 

TUBULAR  CRANE.  Under  the  title  Crane,  that  elegant  mechanical  invention 
of  William  Fairbairn,  Esq.,  F.  R.  S.,  Member  of  the  French  Institute,  is  described  ;  and 
here  an  analysis  of  its  structure  by  Sir  D.  Brewster  may  be  inserted,  as  laid  before 
the  meeting  of  the  British  Association  for  1851.  These  structures  indicate  some  ad 
ditional  examples  of  the  extension  of  the  tubular  system,  and  the  many  advantages 
that  may  yet  be  derived  from  a  judicial  combination  of  wrought  iron  plates,  and  a 
careful  distribution  of  the  material  in  all  those  combinations  which  require  security, 
rigidity,  and  strength. 

The  projection  or  radius  of  the  jib  of  these  cranes  is  32  feet  6  inches  from  the  centre 
of  the  stem,  and  iU  height  80  feet  above  the  ground.    It  is  entirely  composed  of  wrought 
iron  plates,  firmly  riveted  together  on  the  principle  of  the  upper  side  being  calculated 
to  resist  tension,  and  the  under,  or  concave  side,  which  embodies  the  cellular  construction 
to  resist  compression.    The  form  is  correctly  that  of  the  prolonged  vertebra  of  the  bird 
from  which  this  machine  for  raising  weights  takes  its  name;  it  is  truly  the  neck  of  the 
crane,  tapering  from  the  point  of  the  jib,  where  it  is  3  ft.  deep  by  18  inches  wide,  to  the 
level  of  the  ground,  where  it  is  5  ft  deep  and  3  ft.  6  inches  wide.     From  this  point  it 
again  tapers  to  a  depth  of  18  ft.  under  the  surface,  where  it  terminates  in  a  cast-iron 
shoe,  which  forms  the  toe  oa  which  it  revolves.     The  lower  or  concave  side,  which  is 
calculated  to  resist  compression,  consists  of  plates  forming  three  cells,  and  varying  in 
thickness  in  the  ratio  of  the  strain  ;  as  also  the  convex  top,  which  is  formed  of  long  plates 
chain  riveted  with  covers;  but  the  sides  are  of  uniform  thickness,  riveted  with  T  iron, 
and  covering  plate  4^  inches  wide  over  each  joint.     This  arrangement  of  the  parts  and 
distribution  of  the  materials  constitute  the  principal  elements  of  strength  in  the  crane. 
The  form  of  the  jib,  and  the  point  at  which  the  load  is  suspended,  are  probably  not  the 
most  favorable  for  resisting  pressure.      It  nevertheless  exhibits  great  powers  of  re- 
sistance ;  and  its  form,  as  well  as  the  position,  may  safely  be  considered  as  a  curved 
hollow  beam  having  one  end  immoveably  fixed  at  a,  and  the  other  end  c,  the  part  to 
which  the  force  is  applied.   Viewing  it  in  this  light,  the  strengths  are  easily  determined ; 
and  taking  the  experiments  herein  recorded,  we  have  by  the  formula,*  which  was 
originally  framed  for  the  calculation  of  the  ultimate  strength  of  tubular  beams,  that  a 
load  of  63  tons  would  be  required  to  break  the  crane.    With  20  tons  the  deflection  was 
8-97  — -64  of  a  permanent  set  =  3-33  inches,  the  deflection  of  the  jib  due  to  a  load  of 
20  tons.     The  following  constitutes  the  experiments  made  at  Keyham  docks. 


•W= 


^^^  where  W=  breaking  weight  in  tons;  a  the  Bcctional  area  of  the  hottom  of  beam  sub- 


Experiments  made  to  ascertain  the  resisting  Powers  of  a  new  wroughi-iron  tubular  Crane 
erected  at  Keyham  Dockyard,  Devonport,  November  8,  1860. 


Weight  of  cargo 

Deflection  at  the  point  of 

in  tons. 

the  jib  in  inches. 

2 

•32 

3 

•60 

4 

•65 

6 

•90 

6 

ro6 

7 

1-20 

8 

1-35 

9 

1-50 

10 

1-70 

With  5  tons  suspended,  the  crane  was  turned  completely  round,  without  any  alteration 
"n  the  deflection. 

With  this  weight  the  crane  was  again  turned  round;  the  deflection  is  8  minutes 
increasing  to  1^85  inches,  when  it  became  permanent,  after  sustaining  the  load  during 
the  whole  of  the  night,  a  period  of  about  16  hours. 

On  the  9th  November  the  experiments  were  resumed  as  follows: — 


Weight  of  cargo 

Deflection  at  the  point  of 

in  tons. 

the  jib  in  inches. 

11 

2-06 

12 

2-22 

13 

2-40 

14 

2-60 

15 

2^80 

16 

3-00 

17 

3-20 

18 

3-60 

19 

3-73 

20 

397 

l«ct  to  tension ;  d  the  depth  of  beam ;  C  (80).  a  constant  derived  from  experiment,  and  /  the  length  ot 
Mun— an  in  inches. 


On  again  turning  the  crane  round  with  a  load  of  20  tons  there  was  no  perceptible 
alteration  in  the  deflection,  and  the  permanent  set,  after  removing  the  load,  was  ^64 
inches. 

From  the  above  experiments,  it  appears  that  the  ultimate  strength  of  the  crane  is 
much  greater  than  is  requisite  either  in  theory  or  practice,  and,  although  tested  with 
nearly  a  double  load,  it  is  still  far  short  of  its  ultimate  powers  of  resistance,  which  it 
will  be  observed  are  five  times  greater  than  the  weight  it  is  intended  to  bear. 

The  advantages  claimed  for  this  construction  are  its  great  security,  and  the  facility  with 
which  bulky  and  heavy  bodies  can  be  raised  to  the  very  top  of  the  jib  without  failure. 
It  moreover  exhibits,  when  heavily  loaded,  the  same  restorative  principle  of  elasticity 
strikingly  exemplified  in  the  wrouglit-iron  tubular  girder.  Tliese  constructions,  although 
diflfereiit  in  form,  are  nevertheless  the  same  in  principle,  and  undoubtedly  follow  the 
same  law  as  regards  elasticity  and  their  powers  of  resistance  to  fracture.  They  all  do 
great  honor  to  the  mechanical  genius  c   Mr.  Fairbairn. 

TUFA,  or  TUF,  is  a  gray  deposite  of  calcareous  carbonate,  from  springs  and  streams. 

TULA  METAL,  is  an  alloy  of  silver,  copper,  and  lead. 

TUNGSTEN  (Eng.  and  Fr. ;  Wolfram,  Germ.),  is  a  peculiar  metal,  which  occurs  in 
the  state  of  an  acid  (the  tungstic),  combined  with  various  bases,  as  with  lime,  the  oxydes 
of  iron,  raan^:anese,  and  lead.  The  metal  is  obtained  by  reduction  of  the  ore,  or  the  do- 
oxydizement  of  the  acid,  in  the  form  of  a  dark  steel-gray  ^^owder,  which  assumes  under 
the  burnisher  a  feeble  metallic  lustre.     Itf.  specific  gravity  is  ^7-2'2. 

TURBITH  MINERAL,  is  the  yellow  sabsulphate  of  mercury. 

TURF  {Peat,  Scotch;  Tourhe,  Fr. ;  Torf,  Germ.),  consists  of  vegetable  matter,  chiefly 
of  the  moss  family,  in  a  slate  of  partial  decomposition  by  the  action  of  water.  Cut, 
during?  suromer,  into  brick-shaped  pieces,  and  dried,  it  is  extensively  used  as  fuel  by  the 
peasantry  in  every  region  where  it  abounds.  The  dense  black  turf,  which  forms  the  lower 
stratum  of  a  peat-moss,  is  much  contaminated  with  iron,  sulphur,  sand,  &.C.,  while 
the  lighter  turf  of  the  upper  strata,  though  nearly  pure  vegetable  matter,  is  too  bulky  for 
transportation,  and  too  porous  for  factory  fuel.  These  defects  have  been  happily 
removed  by  Mr.  Williams,  managing  director  of  the  Dublin  Steam  Navigation  Company, 
who  has  recently  obtained  a  patent  for  a  method  of  converting  the  lightest  and  purest 


iiliii  I 


874 


TURPENTINE. 


M 


beds  of  peat-moss,  or  bog,  into  the  fonr  following  products :  1,  A  brown  combustible 
solid,  denser  than  oak ;  2,  A  charcoal,  twice  as  compact  as  that  of  hard  wood ; 
8,  A  factitious  coal ;  and  4,  A  factitious  coke ;  each  of  which  possesses  very  valuable 
properties. 

Mr.  D'Ernst,  artificer  of  fire-works  to  Vauxhall,  has  proved,  by  the  severe  test  of  co 
lored  fires,  that  the  turf  charcoal  of  Mr.  Williams  is  20  per  cent,  more  combustible  than 
that  of  oak.  Mr.  Oldham,  engineer  of  the  Bank'of  England,  has  applied  it  in  softening 
his  steel  plates  and  dies,  with  remarkable  success.  But  one  of  the  most  important  results 
of  Mr.  Williams's  invention  is,  that  with  10  cwls.  of  pitcoal,  and  2|  cwts.  of  his  facliliou* 
coal,  the  same  steam  power  is  now  obtained,  in  navigating  the  Company's  ships,  as  witli 
17i  cwts.  uf  pitcoal  alone  ;  thereby  saving  30  per  cent,  in  the  stowage  of  fuel.  What  a 
prospect  is  thus  opened  up  of  turning  to  admirable  account  the  unprofitable  bogs  of  Ire- 
land ;  and  of  producing,  from  their  inexhaustible  stores,  a  superior  fuel  for  every  purpose 
of  arts  and  engineering  ! 

The  turf  is  treated  as  follows: — Immediately  after  being  dug,  if  is  triturated  under  re- 
volving edge-wheels,  faced  with  iron  plates  perforated  all  over  their  surface,  and  is  for- 
ced by  the  pressure  through  these  apertures,  till  it  becomes  a  species  of  pap,  which  is 
freed  from  the  greater  part  of  its  moisture  by  squeezing  in  a  hydraulic  press  between 
layers  of  caya  cloth,  then  dried,  and  coked  in  suitable  ovens. — (See  Charcoal,  and  Pit- 
goal,  COKING  OF.)  Mr.  Williams  makes  his  factitious  coal  by  incorporating  with  pitch 
or  rosin,  melted  in  a  caldron,  as  much  of  the  above  charcoal,  ground  to  powder,  as  will 
form  a  douuhy  mass,  which  is  moulded  into  bricks  in  its  hot  and  plastic  state.  From  the 
experiments  of  M.  Le  Sage,  detailed  in  the  5th  volume  of  "The  Repertory  of  Arts, 
charred  ordinary  turf  seems  to  be  capable  of  producing  a  far  more  intense  heal  than  com- 
mon charcoal.  It  has  been  found  preferable  to  all  other  fuel  for  case-hardening  iron, 
tempering  steel,  forsing  horse-shoes,  and  welding  gun-barrels.  Since  turf  is  partially 
carbonized  in  its  native  slate,  when  it  is  condensed  by  the  hydraulic  press,  and  fully  char- 
red, it  must  evidently  afford  a  charcoal  very  superior  in  calorific  power  to  the  porous  sub- 
stance generated  from  wood  by  fire. 

TURKEY  RED,  is  a  brilliant  dye  produced  on  cotton  goods  by  Madder. 

TURMERIC,  Curcuma^  Terra  merita,  {Soiichet,  or  Safran  des  Indes,  Fr. ;  Gelbwirzel, 
Germ.),  is  the  root  of  the  Curcuma  longa  and  rotunda,  a  plant  which  grows  in  the  East 
Indies,  where  it  is  much  employed  in  dyeing  yellow,  as  also  as  a  condiment  in  curr)'  sauce 
or  powder.  The  root  is  knotty,  tubercular,  oblong,  and  wrinkled ;  pale-yellow  without, 
and  brown-yellow  within  ;  of  a  peculiar  smell,  a  taste  bitterish  and  somewhat  spicy.  It 
contains  a  peculiar  yellow  principle,  called  curcuminCy  a  brown  coloring-matter,  a  volatile 
oil,  starch,  &c.  The  yellow  tint  of  turmeric  is  changed  to  brown-red  by  alkalis,  alka- 
line earths,  subacetate  of  lead,  and  several  metallic  oxydes ;  for  which  reason,  paper 
Stained  with  it  is  employed  as  a  chemical  test. 

Turmeric  is  employed  by  the  wo(d-dyers  for  compound  colors  which  require  an  admix- 
ture of  yellow,  as  for  cheap  browns  and  olives.  As  a  yellow  dye,  it  is  employed  only 
upon  silk.  It  is  a  very  fusitive  color.  A  yellow  lake  may  be  made  by  boiling  tur- 
meric powder  with  a  soiution  of  alum,  and  pouring  the  filtered  decoction  upon  pounded 
chalk. 

TURXSOLE.     See  Archil  and  Litmus. 

TURPENTINE  {Terebinihine,  Fr.;  Terpenthin,  Germ.);  is  a  substsnce  which  flows 
out  of  incisions  made  in  the  6t.em8  of  several  species  of  pines.  It  has  the  consistence 
and  gray-yellow  color  of  honey.  It  has  a  smell  which  is  not  disagreeable  to  many 
person?,  a  warm,  sharp,  bitterish  taste;  dries  into  a  solid  in  the  air,  with  the  evapora- 
tion of  its  volatile  oil.  It  becomes  quite  fluid  at  a  moderate  elevation  of  temperature, 
and  burns  at  a  higher  heat,  with  a  bright  but  very  fuliginous  flame.  There  are  several 
varieties  of  turpentine. 

1.  Common  turpentine,  is  extracted  from  incisions  in  the  Pinus  abies  and  Ptnus  m/- 
vestris.  It  has  little  smell;  but  a  bitter  burning  taste.  It  consists  of  the  volatile  oil 
of  turpentine  to  the  amount  of  from  5  to  25  per  cent. ;  and  of  rosin  or  colophony. 

2.  Venice  turpentine,  is  extracted  from  the  Pinus  larix  (larch)  and  the  French  tur- 
pentine from  the  Pinua  tnaritima.  The  first  comes  from  Styria,  Hungary,  the  Tyrol, 
and  Switzerland,  and  contains  from  18  to  25  per  cent,  of  oil ;  the  second,  from  the  south 
of  France,  and  contains  no  niore  than  12  per  cent,  of  oil.  The  oil  of  all  the  turpen- 
tines is  extracted  by  distilling  them  along  with  water.  They  dissolve  in  all  proportions 
in  alcohol,  without  leaving  any  residuum.  They  also  combine  alkaline  lyes,  and  in 
general  with  the  salifiable  bases.     Venice  turpentine  contains  also  succinic  acid. 

8.  Turpentine  of  Strasbourg  is  extracted  from  the  Pinus  picea  and  Abies  excelsa. 
It  affords  33-5  per  cent  of  volatile  oil,  and  some  volatile  or  crystallisable  resin,  with 
extractive  matter  and  succinic  acid. 

4.  Turpentine  of  the  Carpathian  mountains,  and  of  Hungary;   the  first  of  whick 


TYPE. 


875 


comes  from  the  Pinus  cembra,  and  the  second  from  the  Pimis  muffox.    They  resemble 
that  of  Strasbourg. 

6.  Turpentine  of  Canada,  called  Canada  balsam,  is  extracted  from  the  Pinus  cana- 
densis and  bahainea.     Its  smell  is  much  more  agreeable  than  that  of  the  preceding 

species.  , .     ,         t*.  i. 

6.  Turpentine  of  Cyprus  or  Chio  is  extracted  from  the  Pistacea  terehinthus.  It  has 
a  yellow,  greenish,  or  blue-green  color.  Its  smell  is  more  agreeable,  and  taste  leas 
acrid,  than  those  of  the  preceding  sorts.  , 

TURPENTINE,  OIL  OF,  sometimes  called  essence  of  turpentine.  As  found  in 
commerce,  it  contains  more  or  less  rosin,  from  which  it  may  be  freed  by  re-distillation 
along  with  water.  It  is  colorless,  limpid,  very  fluid,  and  possessed  of  a  very  peculiar 
smell.  Its  specific  gravity,  when  pure,  is  0-870;  that  of  the  oil  commonly  sold  m 
London  is  0-876.  It  always  reddens  litmus  paper,  from  containing  a  little  succinic 
acid.  According  to  Opermann,  the  oil  which  has  been  repeatedly  rectified  over 
chloride  of  calcium,  consists  of  84-60  carbon,  11-735  hydrogen,  and  3-67  oxygen. 
When  oil  of  turpentine  contains  a  little  alcohol,  it  burns  with  a  clear  flame;  but  other- 
wise it  affords  a  very  smoky  flame.  Chlorine  inflames  this  oil ;  and  muriatic  acid  con- 
verts it  into  a  crystalline  substance,  like  camphor.  It  is  employed  extensively  in  var- 
nishes, paints,  <fee.,  as  also  in  medicine. 

TURPENTINE,  SPIRITS.  ESSENCE  OR  OIL  OF.  Camphen  is  the  new  name 
given  by  the  continental  chemists  to  every  etherous  or  volatile  oil  which  is  composed 
of  5  atoms  of  carbon  and  8  of  hydrogen,  and  which  combines  directly  with  hydro- 
chloric acid,  either  into  a  solid  or  a  liquid  compound,  resembling  camphor.  Under  this 
title  the  following  oils  are  included:— turpentine,  citron,  or  lemon,  orange-flower, 
copaiva,  balsam  oil,  juniper,  cubebs,  and  pepper.  Some  add  to  this  last, — the  oils  of 
cloves,  valerian,  and  bergamot  As  the  new  patent  lamps  burn  spirits  of  turpentine 
they  have  been  called  Camphine.     See  Lamps. 

Common  turpentine  imported  into  the  United  Kingdom,  in  1850,437,121  cwta.; 
in  1851,  431,950  cwts. 

TURQUOIS.     See  Lapidary. 
TUTENAG,  is  an  alloy  of  copper  and  zinc. 

TYPE  {Caractere,  Fr. ;  Druckbuchstabe,  Germ.)  The  first  care  of  the  letter-cutter 
is  to  prepare  well  tempered  steel  punches,  upon  which  he  draws  or  marks  the  exact 
shape  of  the  letter,  with  pen  and  ink  if  it  be  large,  but  with  a  smooth  blunted  point  of 
a  needle  if  it  be  small ;  and  then  wuth  a  proper  sized  and  shaped  graver  and  sculpter, 
he  digs  or  scoops  out  the  metal  between  the  strokes  upon  the  face  of  the  punch,  leaving 
the  marks  untouched  and  prominent.  He  next  works  the  outside  with  files  till  it  be 
fit  for  the  matrix.  Punches  are  also  made  by  hammering  down  the  hollows,  filing 
up  the  edges,  and  then  hardening  the  soft  steel.  Before  he  proceeds  to  sink  and  justify 
the  matrix,  he  provides  a  mould  to  justify  them  by,  of  which  a  good  figure  is  shown  in 
plate  XV.,  Miscellany,  Jigs.  2,  3,  of  Rees's  Cyclopcedia. 

A  matrix  is  a  piece  of  brass  or  copper,  about  an  inch  and 
a  half  long,  and  thick  in  proportion  to  the  size  of  the  letter 
which  it  is  to  contain.  In  this  metal  the  face  of  the  letter 
intended  to  be  cast  is  sunk,  by  striking  it  with  the  punch  to 
a  depth  of  about  one  eighth  of  an  inch.  The  mould,  fig. 
1483,  in  which  the  types  are  cast  is  composed  of  two  parts. 
The  outer  part  is  made  of  wood,  the  inner  of  steel.  At  the 
top  it  has  a  hopper-mouth  a,  into  which  the  fused  type-metal 
is  poured.  The  interior  cavity  is  as  uniform  as  if  it  had  been 
hollowed  out  of  a  single  piece  of  steel ;  because  each  hal^ 
which  forms  two  of  the  four  sides  of  the  letter,  is  exactly  fit- 
ted to  the  other.  The  matrix  is  placed  at  the  bottom  of  the 
mould,  directly  under  the  centre  of  the  orifice,  and  is  held  in 
its  position  by  a  spring  b.  Every  letter  that  is  cast  can  be 
loosened  from  the  matrix  only  by  removing  the  pressure  on 
the  spring. 

A  good  type-foundry  is  always  provided  with  several  fur- 
naces, each  surmounted  with  an  iron  pot  containing  the  melt- 
ed alloy,  of  3  parts  of  lead  and  1  of  antimony.  Into  this  pot 
the  founder  dips  the  very  small  iron  ladle,  to  lift  merely  aa 
much  metal  as  will  cast  a  single  letter  at  a  time.  Having  poured  in  the  metal  with 
his  right  hand,  and  returned  the  ladle  to  the  melting-pot^  the  founder  throws  up  his  left 
hand,  which  holds  the  mould,  above  his  head,  with  a  sudden  jerk,  supporting  it  with  his 
right  hand.  It  is  this  movement  which  forces  the  metal  into  all  the  interstices  of  the 
matrix :  for  without  it,  the  metal,  especially  iu  the  smaller  moulds,  would  not  be  able 


1483 


I 


!t  llllili 


['!! 


iiliillll 


illi'Pi 


9m 


TYPE. 


to  expel  the  air  and  reach  the  bottom.  The  pouring  in  the  metal,  the  throwing  up  the 
mould,  the  unclosing  it,  removing  the  pressure  of  the  spring,  picking  out  the  cast  letter, 
oloaing  the  mould  again,  and  re-applying  the  spring  to  be  ready  for  a  new  operation, 
are  all  performed  with  such  astonishing  rapidity  and  precision,  that  a  skilful  workman 
will  turn  out  500  good  letters  in  an  hour,  being  at  the  rate  of  one  every  eighth  part 
of  a  minute.  A  considerable  piece  of  metal  remains  attached  to  the  end  of  the  type  as 
it  quits  the  mould.  There  are  nicks  upon  the  lower  edge  of  the  types,  to  enable  tha 
compositor  to  place  them  upright  without  looking  at  them. 

From  the  table  of  the  caster,  the  heap  of  types  turned  out  of  his  mould,  is  transferred 
from  time  to  time  to  another  table,  by  a  boy,  whose  business  it  is  to  break  off  the  super- 
fluous metal,  and  that  he  does  so  rapidly  as  to  clear  from  2000  to  5000  types  in  an  hour; 
a  very  remarkable  despatch,  since  he  must  seize  them  by  their  edges,  and  not  by  their 
feeble  flat  sides.  From  the  breakin^-off  boy,  the  types  are  taken  to  the  rutber,  a  man 
who  sits  in  the  centre  of  the  workshop  with  a  ^rit-slone  slab  on  a  table  before  him,  and 
having  on  the  fore  and  middle  finger  of  his  right  hand  a  piece  of  tarred  leather,  passes 
each  broad  side  of  the  type  smartly  over  the  stone,  turning  it  in  t^e  movement,  and  that 
so  dexterously,  as  to  be  able  to  rub  2000  types  in  an  hour. 

From  the  rubber,  the  types  are  conveyed  to  a  boy,  who,  with  equal  rapidity,  sets  them 
up  in  lines,  in  a  long  shallow  frame,  with  their  faces  uppermost  and  nicks  outwards. 
This  frame,  containing  a  full  line,  is  put  into  the  dresser's  hands,  who  polishes  them  on 
each  side,  and  turning  them  with  their  fices  downwards,  cuts  a  groove  or  channel  ia 
their  bottom,  to  make  them  stand  steadily  on  end.  It  is  essential  that  each  letter  be  per- 
fectly symmetrical  and  square;  the  least  inequality  of  their  length  would  prevent  them 
from  making  a  fair  impression  ;  and  were  there  the  least  obliquity  in  their  sides,  it  would 
be  quite  impossible,  when  200,000  sinsjle  letters  are  combined,  as  in  one  side  of  the  TinuM 
newspaper,  that  they  could  hold  together  as  they  require  to  do,  when  wedged  up  in  the 
chases,  as  securely  as  if  that  side  of  type  formed  a  solid  plate  of  metal.  Each  letter  is  finally 
tied  up  in  lines  of  convenient  length,  the  proportionate  numbers  of  each  variety,  small 
letters,  points,  large  capitals,  small  capitals,  and  figures,  being  selected,  when  the  fount 
of  type  is  ready  for  delivery  to  the  printer. 

The  sizes  of  types  cast  in  this  country  vary  from  the  smallest,  called  diamond,  of  which 
205  lines  are  contained  in  a  foot  length,  to  those  letters  employed  in  placards,  of  which  a 
single  letter  may  be  three  or  four  inches  high.  The  names  of  the  different  letters  and 
their  dimensions,  or  the  number  of  lines  which  each  occupies  in  a  foot,  are  stated  in  the 


following  table : — 


Double  Pica, 

-    4li 

Small  Pica,     - 

-      83 

Nonpareil,    - 

-    143 

Paragon, 

44i 

Long  Primer, 

89 

Agate, 

166 

Great  Primer,    - 

-    51i 

Bourgeois, 

-     102i 

Pearl,  - 

-    178 

English, 

64 

Brevier, 

1121 

Diamond,  - 

205 

Pica, 

-    7lt 

Minion, 

-     128 

T.  Aspinwall,  Esq.,  the  American  Consul,  obtained,  in  May,  1828,  a  patent  for  an  im- 
proved method  of  casting  printing  types  by  means  of  a  mechanical  process,  being  a  com- 
munication from  a  foreigner  residing  abroad.  The  machine  is  described,  with  six  expla- 
natory figures,  in  the  second  series  of  Newton's  Journal,  vol.  v.  page  212.  The  patentee 
does  not  claim,  as  his  invention,  any  of  the  parts  separately,  but  the  general  process  and 
wrangement  of  machinery;  more,  particularly  the  manner  of  suspending  a  swing  table 
(apon  which  the  working  parts  are  mounted)  out  of  the  horizontal  and  perpendicular  po- 
sition ;  the  mode  of  moving  the  table  with  the  parts  of  the  mould  towards  the  melting 
pot ;  the  manner  of  bringing  the  parts  of  the  mould  together,  and  keeping  them  closed 
during  the  operation  of  casting  the  types.  Several  other  mechanical  schemes  have  beea 
proposed  for  founding  types,  but  I  have  been  informed  by  very  competent  judges,  Messrs. 
Clowes,  that  none  of  them  can  compete  in  practical  utility  with  that  dexterity  and  precision 
of  handiwork,  which  I  have  often  seen  practised  in  their  great  printing  establishment  ia 
Stamford  street. 


ULTRAMARINE. 


877 


U. 

ULTRAMARINE  (Outremer,  Fr. ;  Ultramarins,  Germ.),  is  a  beautiful  blue  piawem 
Obtained  from  the  variegated  blun  mineral,  called  lazulite  Qapis  lazuli),  bv  the  follow, 
mg  process  :—Grmd  the  stone  to  fragments,  rejecting  all  the  colorless  bits, 'calcine  at  a 
red  heat,  quench  m  water,  and  then  grind  to  an  impalpable  powder  along  with  water,  in 
a  pamt-mill  (see  Paints,  grinding  of),  or  with  a  porphyry  slab  and  muller.  The  paste, 
being  dried,  is  to  be  rubbed  to  powder,  and  passed  through  a  silk  sieve.  100  parts  of  it 
are  to  be  mixed  with  40  of  rosin,  20  of  white  wax,  25  of  linseed  oil,  and  15  of  Burgundy 
pitch,  previously  melted  together.  This  resinous  compound  is  to  be  poured  hot  into  cold 
water;  kneaded  well  first  with  two  spatulas,  then  with  the  hands,  and  then  formed  into 
one  or  more  small  rolls.  Some  persons  prescribe  leaving  these  pieces  in  the  water  during 
lifleen  days,  and  then  kneading  them  in  it,  whereby  they  give  out  the  blue  pigment,  ap- 
parently  because  the  ultramarine  matter  adheres  less  strongly  than  the  gawgwr,  or  merely 
silicious  matter  of  the  mineral,  to  the  resinous  paste.  MM.  Clement  and  Desoimes  who 
were  the  first  to  divine  the  true  nature  of  this  pigment,  think  that  the  soda  contained  in  the 
lazulite,  uniting  with  the  oil  and  the  rosin,  forms  a  species  of  soap,  which  serves  to  wash 
out  the  coJoring-matter.  If  it  should  not  separate  readily,  water  healed  to  about  150=*  F. 
should  be  had  recourse  to.  When  the  water  is  sufficiently  charged  with  blue  color,  it 
IS  poured  oflT  and  replaced  by  fresh  water:  and  the  kneading  and  change  of  water  are 
repeated  till  the  whole  of  the  color  is  extracted.  Others  knead  the  mixed  resinous  mass 
under  a  slender  stream  of  water,  which  runs  oflf  with  the  color  into  a  large  earthen  pan. 
The  first  waters  aflford,  by  rest,  a  deposite  of  the  finest  ultramarine ;  the  second,  a 
somewhat  inferior  article,  and  so  on.  Each  must  be  washed  afierwai-ds  with  several 
more  waters,  before  they  acquire  the  highest  quality  of  tone;  then  dried  separately,  and 
freed  from  any  adhering  particles  of  the  pitchy  compound  by  digestion  in  alcohol.'  The 
remainder  of  the  mass  being  melted  with  oil,  and  kneaded  in  water  containing  a  little 
coda  or  potash,  yields  an  inferior  pigment,  called  nltramarim  ashes.  The  best  ttW/atno- 
nne  is  a  splendid  blue  pigment,  which  works  well  with  oil,  and  is  not  liable  to  chan<-e  by 
time.  Its  price  m  Italy  was  five  guineas  the  ounce,  a  few  years  ago,  but  it  is  now  creaUr 
reduced.  -  -=  ?  »         / 

The  blue  color  of  Inzulite  had  been  always  ascribed  to  iron,  till  MM.  Clement  and 
Desormes,  by  a  most  careful  analysis,  showed  it  to  consist  of— silica,  34;  alumina  33- 
sulphur,  3;  soda,  22;  and  that  the  iron,  carbonate  of  lime.  &c.,  were  accidental  ingre- 
dients, essential  neither  to  the  mineral,  nor  to  the  pigment  made  from  it.  Bv  another 
analyst,  the  constituents  are  said  to  be— silica,  44;  alumina,  35  ;  and  soda,  21 ;'  and  by  a 
third,  potassa  was  found  instead  of  soda,  showing  shades  of  diflerence  in  the  composition 
of  the  stone. 

•  "^oL^  ?,^^  •'^^''^  ®"°'  '^^'^^^' «^'<^inpt  failed  to  make  ultramarine  artificially.  At  len«»th, 
in  1828,  M.  Guimet  resolved  the  problem,  guided  by  the  analysis  of  MM!  Clement  and 
Desormes,  and  by  an  observation  of  M.  Tassaert,  that  a  blue  substance  like  ultramarine 
was  occasionally  produced  on  the  sandstone  hearths  of  his  reverberatory  soda  furnaces. 
Of  M.  Guiraet  s  finest  pigment  I  received  a  bottle  several  years  ago,  from  mv  friend  M 
Merimee,  Secretary  of  the  Ecok  dc  Beaux  .dris.  which  has  been  found  by  art'ists  little  if 
any,  inferior  to  the  lazulite  ultramarine.  M.  Guimet  sells  it  at  sixty  francs  per  pound 
French.— which  is  little  more  than  two  guineas  the  English  pound.  He  has  kept 
his  process  secret.  But  M.  Gmelin,  of  Tiibingen,  has  published  a  prescription  for 
making  It ;  which  consists  in  enclosing  carefully  in  a  Hessian  crucible  a  mixture  of  two 
parts  of  sulphur,  and  one  of  dry  carbonate  of  soda,  heating  them  gradually  to  redness  till 
the  mass  fuses,  and  then  sprinkling  into  it  by  degrees  another  mixture,  of  silicate  of  soda, 
and  a  uminate  of  soda;  the  first  containing  seventy-two  parts  of  silica,  and  the  second 
jevenly  parts  of  alumina  The  crucible  must  be  exposed  after  this  for  an  hour  to  the  fire. 
The  ultramarine  will  be  formed  by  this  time;  only  it  contains  a  little  sulphur,  which  can 
be  sepamted  by  means  of  water.  M.  Persoz,  professor  of  chemistry  at  Strasbourg,  has 
likewise  succeeded  in  making  an  ultramarine,  of  perhaps  still  better  quality  than  that  of 
M.  Guimet.  Lastly,  M.  Robiquet  has  announced,  that  it  is  easy  to  form  ultramarine. 
by  heating  to  redness  a  proper  mixture  of  kaolin  (China  clay),  sulphur,  and  carbonate 
of  soda.  It  would  therefore  appear,  from  the  preceding  details,  that  ultramarine  may 
be  regarded  as  a  coinpound  of  silicate  of  alumina,  silicate  of  soda,  with  sulphuret  of 
•odium;  and  that  to  the  reaction  of  the  last  constituent  upon  the  former  two,  it  owes  its 
color. 


It 


iiiiiii 


r  I     'Tfn 


itiii'iii! 


M 


878 


ULTRAMARINE. 


ANALYSIS   OF   ULTRAMARINE   BY   WARHENTRAP, 


Lapis  Laznii 
Potash 

Artificial  from 
Meissen 
1-75 

Eisner. 
Blue.                      Oreeo. 

Soda 

909 

21-47 

40-0 

26-6 

Alumina 

31-07 

23-30 

29*5 

300 

Silica 

42-50 

45  00 

40-0 

89-9 

Sulphur 
Lime 

0-95 
3-62 

1-68 
0-02 

4-0 

4-6 

Iron 
Chlorine 

0-86 
0-42 

1-06 

1-0 

0-9 

Sulphuric 
Water 

Acid 

5-89 
0-12 

3-83 

8*4 

0-4 

ULTRAMARINE,  ARTIFICIAL.  Till  within  these  last  16  or  18  years,  the  only 
source  of  this  beautiful  pigment  was  the  rare  mineral  lapis  lazuli.  The  price  of  th« 
finest  ultramarine  was  then  so  high  as  five  guineas  the  ounce.  Since  the  mode  of 
making  it  artificially  has  been  discovered,  however,  its  price  has  fallen  to  a  few  shillings 
per  pound,  and  even  to  a  little  more  than  one  shilling  wholesale,  for  a  fair  article.  Arti- 
ficial ultramarine  is  now  manufactured  to  a  very  considerable  extent  on  the  Continent, 
and  also  in  London.  The  chief  French  manufactories  of  ultramarine  are  situated  in 
Paris,  and  the  two  largest  ones  in  Germany  are  those  of  Meissen  in  Saxony,  and  of 
Nuremberg  in  Franconia.  Three  kinds  of  ultramarine  occur  in  commerce,  the  blue, 
the  green,  and  the  yellow.  The  first  two  only  are  true  ultramarines ;  that  is,  sulphur 
compounds ;  the  yellow  is  merely  chromate  of  baryta. 

Both  native  and  artificial  ultramarine  have  been  examined  very  carefully  by  several 
eminent  chemists,  who,  however,  have  been  unable  to  throw  much  light  upon  their  true 
nature.  Chemists  have  undoubtedly  ascertained  that  ultramarine  always  consists  of  silica, 
alumina,  soda,  sulphur,  and  a  little  oxide  of  iron ;  but  no  two  specimens,  either  of  the 
native  or  artificial  ultramarine,  contain  these  ingredients  in  at  all  similar  proportions. 
In  fact  the  discrepancies  between  the  analysis  are  so  great,  as  to  render  it  impossible  to 
deduce  from  them  any  formula  for  the  constitution  of  ultramarine ;  if  indeed  it  does 
possess  any  definite  composition.  The  following  are  a  few  specimens  of  these  analyses^ 
and  others  equally  discordant  might  easily  be  added. 


Soda 

Alumina    - 
Silica 
Sulphur 
Carbonate  of  lime 


Soda  and  potash    • 

Lime  .  -  . 

Alumina     -  - 

Silica  -  - 

Sulphuric  acid 

Resin,  sulphur,  and  loss    - 


Lapis  Lazuli,  by  Clement  and 
Desormea. 

-  23-2 

-  248 

-  35-8 

-  3-1 

-  31 

Parisian  artificial  ultramine, 
by  C.  O.  Gmelin. 

-  12-863 

-  1-546 

-  22-000 

-  47-306 

-  4-679 

-  12-218 


Dr.  Eisner  published  a  very  elaborate  paper  upon  ultramarine  in  the  23rd  number 
ot  Erdmann's  Journal  for  1841.  The  first  part  of  Dr.  Eisner's  paper  is  historical,  and 
contains  an  account  of  the  accidental  discovery  of  artificial  ultramarine  by  Tassaert  and 
Kuhlman  in  1814,  and  of  the  labors  of  subsequent  chemists.  He  then  gives  a  detailed 
account  of  his  own  experiments,  which  have  been  very  numerous,  and  from  these  he 
deduces  the  following  conclusions:  1st,  that  the  presence  of  about  1  per  cent  of  iron  is 
indispensable  to  the  production  of  ultramarine ;  he  supposes  the  iron  to  be  in  a  state 
of  sulphuret  2d,  that  the  green  ultramarine  is  first  formed,  and  that  as  the  heat  is  in- 
creased, it  passes  by  degrees  into  the  blue.  The  cause  of  this  change  is.  he  affirms,  that 
part  of  the  sodium  absorbs  oxygen  from  the  atmosphere,  as  the  operation  is  conducted 
in  only  partially  closed  vessels,  and  combines  with  the  silica,  while  the  rest  of  the  sodium 
passes  into  a  higher  degree  of  sulphuration.  Green  ultramarine,  therefore,  contains 
simple  sulphurets,  and  blue,  polysulphurets. 

Dr.  Eisner's  paper  does  not,  however,  furnish  any  details  by  which  ultramarine  could 
be  manufactured  successfully  on  the  great  scale.    Thus,  for  example,  in  regard  to  the 


VACUUM-MADE  LIQUEURS. 


879 


necessary  degree  of  heat,  perhaps  the  roost  important  circumstances  in  the  process,  he 
gives  no  directions  whatever.  We  know  however,  from  other  sources,  that  it  should 
be  a  low  red  heat,  as  at  much  higher  temperatures  both  native  and  artificial  ultrama- 
rines soon  become  colorless.  Dr.  Eisner,  indeed,  does  not  affirm  that  he  was  able  to 
procure  ultramarine  in  quantity  of  a  uniformly  good  color.  In  fact,  the  process  of 
Kobiquet,  published  nearly  ten  years  ago,  is  the  best  which  scientific  chemists  possess, 
though  undoubtedly  the  manufacturers  have  greatly  improved  upon  it.  Robiquet's 
process  consists  in  heating  to  low  redness  a  mixture  of  one  part  porcelain  clay,  one  and 
a  half  sulphur,  and  one  and  a  half  parts  anhydrous  carbonate  of  soda,  either  in  an  earth- 
enware retort  or  covered  crucible,  so  long  as  vapors  are  given  off.  When  opened,  the 
crucible  usually  cont-ains  a  spongy  mass  of  deep  blue  color,  containing  more  or  less  ul- 
tramarine mixed  with  the  excess  of  sulphur  employed,  and  some  unaltered  clay  and 
soda.  The  soluble  matter  is  removed  by  washing,  and  the  ultramarine  separated  from 
the  other  impurities  by  levigation.  It  is  to  be  regretted,  however,  that  the  results  of 
Robiquet's  process  are  by  no  means  uniform  ;  one  time  it  yields  a  good  deal  of  ultra- 
marine of  excellent  quality,  and  perhaps,  at  the  very  next  repetition  of  the  process  in 
circumstances  apparently  similar,  very  little  ultramarine  is  obtained,  and  that  of  an  in- 
ferior quality. 

The  fabrication  of  ultramarine  is  a  subject  which  well  deserves  the  attention  of  English 
chemical  manufacturers,  as  it  could  be  carried  on  with  peculiar  advantage  in  this  coun- 
try. The  chief  expense  of  the  process  is  the  fuel  required,  which  can  be  purchased 
in  Great  Britain  for  less  than  half  the  money  it  would  cost  either  in  France  or  Ger- 
many. 

UMBER,  is  a  massive  mineral ;  fracture  large  and  flat;  conchoidal  in  the  great^  very 
fine  earthy  in  the  small ;  dull;  color,  liver,  chestnut,— dark  yellowish  brown  ;  opaque; 
does  not  soil,  but  writes ;  adheres  strongly  to  the  tongue,  feels  a  little  rough  and  meagre, 
and  is  very  soft;  specific  gravity  2-2.  It  occurs  in  beds  with  brown  Jasper  in  the  island 
of  Cyprus,  and  is  used  by  painters  as  a  brown  color,  and  to  make  varnish  dry  quickly. 

URANIUM,  is  a  rare  metal,  first  discovered  by  Klaproth,  in  the  black  mineral  called 
pechblende,  found  in  a  mine  near  Johan-Georgen-Stadt,  in  Saxony,  and  which  is  a 
sulphuret  of  uranium.  A  double  phosphate  of  uranium  and  copper,  called  green 
waniie,  and  uran  triica,  occurs  in  Cornwall.  It  has  been  reduced  to  the  metallic  state 
by  various  devices,  but  it  has  hardly  the  appearance  of  metal  to  the  naked  eye,  and 
from  the  rarity  of  its  ores  is  not  likely  to  be  of  any  importance  in  the  arts,  except  to 
color  glass. 

URAO,  is  the  native  name  of  a  sesquicarbonate  of  soda  found  at  the  bottom  of  cer- 
tain lakes  in  Mexico,  especially  to  the  north  of  Zacatecas,  and  in  several  other  provinces; 
also  in  South  America  at  Colombia,  48  English  miles  from  Merida. 

UREA.  The  quantity  of  urea  present  in  urine  may  be  estimated  with  great  facility 
by  treating  the  urine  with  a  standard  solution  of  the  pernitrate  of  mercury.  A  copious 
■white  precipitate,  resembling  the  chloride  of  silver,  with  liberation  of  nitric  acid,  falls. 
As  this  acid  prevents  the  further  action  of  the  nitrate,  it  must  be  neutralized  by  water 
of  barytes.  A  further  quantity  of  the  nitrate  of  mercury  is  to  be  now  added,  and  so  on, 
by  repeated  additions  of  the  test,  and  subsequent  neutralization  with  barytes,  till  the 
whole  urea  is  precipitated.  The  addition  of  more  of  the  nitrate  of  mercury  produces  a 
yellow  precipitate  of  binoxide  of  mercury.  The  quality  of  urea  present  in  a  given 
sample  of  urine,  may  thus  be  readily  deduced  from  the  quantity  of  a  solution  of  nitrate 
of  mercury  required  for  its  precipitation.    The  urine  should  be  fresh. 


V. 


VACUUM-MADE  LIQUEURS.  Samples  of  brandy  made  of  alcohol  and  fruits  of 
various  kinds  by  distillation  in  a  vacuum. 

In  this  manufacture  about  200  lbs.  of  these  fruits  yield  nearly  7  quarts  of  black  cherry 
brandy,  having  the  flavor  of  prussic  ether. 

These  brandies  may  serve  as  the  basis  of  all  compositions  of  fruit  tafias,  without  pre- 
judice to  the  delicacy  of  the  flavor.  The  brandy  has  the  taste  and  flavor  of  the  fruit. 
It  is  mild  and  destitute  of  the  burning  taste  common  to  wine  brandy.  Pure  or  mixed 
■with  water  it  is  an  agreeable  drink,  and  tnay  from  its  variety,  taste,  and  flavor,  advan- 
tageously replace  other  spirituous  mixtures. 


880 


VANILLA. 


VARNISH. 


881 


The  liqueurs  prepared  from  these  various  sorts  of  brandy  are  called  marasquin,  on 
account  of  their  analogy  to  those  of  Venice  and  Trieste.  They  are  manufactured  from 
the  fruit  of  a  variety  of  laurels  (cherry  bay),  called  in  Italy  mirasca. 

The  distillation  in  vacuo  deprives  the  mixture  of  the  coarse  essential  oil  which 
remains  after  ordinary  distillation,  and  which  contains  the  resinous  and  heterogeneous 
substances  so  disagreeable  to  the  palate  and  injurious  to  the  stomach.  The  disrillation 
m  vacuo  is  earned  on  at  from  40°  to  60°  of  temperature,  instead  of  120°  to  150°  in  the 
ordinary  process. 

This  marasquin  from  the  wild  or  brandy  cherry  is  a  cephalic  The  cherry  is  tonic 
and  mikl  The  peach  approximates  to  the  cherry.  The  strawberry  is  diuretic  and 
beneficial  in  phthisical  complaints  and  weak  constitutions.  The  raspberry  is  cooling  and 
antiscorbutic  ;  mixed  with  water  it  is  a  sweet  and  agreeable  beverage.  The  flavor  of 
the  black  currant  is  very  superior,  and  the  operation  of  the  vacuum,  instead  of  weaken- 
ing, concentrates  the  properties  of  the  fruit.     An  Exhibition  puff. 

VALONIA,  is  a  kind  of  acorn,  imported  from  the  Levant  and  the  ftlorea  for  tne  use 
of  tanners,  as  the  husk  or  cup  contains  abundance  of  tannin.  The  quantity  imported 
for  home  consumption  in  1836,  was  80,511  cwts. ;  of  which  Turkey  furnished  .78,724. 
Italy  and  the  Italian  islands,  7209. 

VANADIUM,  is  a  metal  discovered  by  Sefstrom,  in  1830,  in  a  Swedish  iron,  remarka- 
ble for  Its  ductility,  extracted  from  the  iron  mine  of  Jabera:,  not  far  from  Jonkiipino. 
Its  name  is  derived  from  Vanadis,  a  Scandinavian  idol.  This  metal  has  been  found  fn 
the  state  of  vanadic  acid,  in  a  lead  ore  from  Zimapan,  in  Mexico.  The  finery  cinders  of 
the  Jaberg  iron  contain  more  vanadium  than  the  metal  itself.  It  exists  in  it  as  vanad'r 
acid.  For  the  reduction  of  this  acid  to  vanadium,  see  Berzelius's  TraiU  de  Chimie.y  voC 
IV.  p.  644.  Vanadium  is  white,  and  when  its  surface  is  iwlished,  it  resembles  silver  oi 
molybdenum  more  than  any  other  metal.  It  combines  with  oxygen  into  two  oxydes  and 
an  acid. 

The  vanadate  of  ammonia,  mixed  with  infusion  of  nutgalls,  forms  a  black  liquid 
which  is  the  best  writing-ink  hitherto  known.  The  quantity  of  the  salt  requisite  is  so 
small  as  to  be  of  no  importance  when  the  vanadium  comes  to  be  more  extensively  ex- 
tracted. The  writing  is  perfectly  black.  The  acids  color  it  blue,  but  do  not  remove 
It,  as  they  do  lannate  of  iron:  the  alkalis,  diluted  so  far  as  not  to  injure  the  paper  do  not 
dissolve  it ;  and  chlorine,  which  destroys  the  black  color,  does  not,  however,  make  the 
traces  illegible,  even  when  they  are  subsequently  Avashed  with  a  stream  of  wate^  It  is 
perfectly  fluent,  and,  being  a  chemical  solution,  stands  in  want  of  no  viscid  sum  to  sus- 
pend the  color,  like  common  ink.  The  influence  of  time  upon  it  rem'ains  to  be 
tried. 

VANILLA,  is  the  oblong  narrow  pod  of  the  Epvlendron  vanilla,  Linn.,  of  the  natural 
family  Orchi(k(B,  which  grows  in  Mexico,  Colombia,  Peru,  and  on  the  banks  of  the 
Oronoco. 

The  best  comes  from  the  forests  rouni  the  village  of  Zentila,  in  the  intendancy  of 
v/axaca. 

The  vanilla  plant  is  cultivated  in  Brazil,  in  the  West  Indies,  and  some  other  tropical 
countries,  but  does  not  produce  fruit  of  such  a  delicious  aroma  as  m  Mexico.  It  clings 
like  a  parasite  to  the  trunks  of  old  trees,  and  sucks  the  moisture  which  their  bark  de- 
rives from  the  lichens,  and  other  crypto^amia,  but  without  drawin?  nourishment  from 
the  tree  itself,  like  the  ivy  and  mistletoe.  The  fruit  is  subcylindric,  about  8  inches 
long,  one-celled,  siliquose,  and  pulpy  within.    It  should  be  gathered  before  it  i«  fully 


ripe. 


When  about  12000  of  these  pods  are  collected,  they  are  strung  like  a  garland  by  their 
lower  end,  as  near  as  possible  to  the  foot-stalk ;   the  whole  are  plunged  for  an  instant 
m  boiling  water  to  blanch  them ;  they  are  then  hunjj  up  in  the  open  air,  and  expo«!ed 
to  the  sun  for  a  few  hours.     Next  day  they  are  lightly  smeared  with  oil,  by  means  of  a 
feather,  or  the  fingers;  and  are  surrounded  with  oiled  cotton,  to  prevent  the  valves  from 
cpening.     As  they  become  dry,  on  inverting  their  upper  end,  they  discharge  a  viscid 
liquid  worn  it,  and  they  are  pressed  at  several  times  with  oiled  fin?ers  to  promote  its 
flow.     The  dried  pod?  lose  their  appearance,  grow  brown,  wrinkled,  soft,  and  shrink 
into  one  fourth  of  their  original  size.     In  this  state  they  are  touched  a  second  time 
with  oil,  but  very  sparingly ;    because,  with  too  much  oil,  they  would  lose  much  of  their 
delicious  perfume.     They  are  then  packed  for  the  market,  in  small  bundles  of  50  or 
100  in  each,  enclosed  in  lead  foil,  or  tight  metallic  cases.    As  it  comes  to  us,  vanilla  is 
a  capsular  fruit,  of  the  thickness  of  a  swan's  quill,  straight,  cylindrical,  but  somewhat 
flattened,  truncated  at  the  top,  thinned  off"  at  the  ends,  glistenin?,  wrinkled,  furrowed 
lengthwise,  flexible,  from  5  to  10  inches  long,  and  of  a  reddish-brown  colo^     It  con. 
tains  a  pulpy  parenchyma,  soft,  unctuous,  very  brown,  in  which  are  imbedded  black, 
brilliant,  very  small  seeds.    Its  smell  is  ambrosiacal  and  aiomaUcj  its  taste  hot,  and 


rather  sweetish.  These  properties  seem  to  depend  upon  an  essential  oil,  and  also  npo« 
benzoic  acid,  which  forms  efflorescences  upon  the  surface  of  the  fruit.  The  pulpy  part 
possesses  alone  the  aromatic  quality;  the  pericarpium  has  hardly  any  smell. 

The  kind  most  esteemed  in  France,  is  called  Uq  vanilla;  it  is  about  6  inches  long, 
from  i  to  I  of  an  inch  broad,  narrowed  at  the  two  ends,  and  curved  at  the  base ; 
somewhat  soft  and  viscid,  of  a  dark-reddish  color,  and  of  a  most  delicious  flavor,  like 
that  of  Balsam  of  Peru.  It  is  called  vanilla  givrees,  when  it  is  covered  with  efflorescence! 
of  benzoic  acid,  after  having  been  kept  in  a  dry  place,  and  in  vessels  not  hermetically 
closed. 

The  second  sort,  called  vanilla  simarona,  or  bastard,  is  a  little  smaller  than  the  fre- 
ced ins,  of  a  less  deep  brown  hue,  drier,  less  aromatic,  destitute  of  efflorescence.  It  is 
said  to  be  the  produce  of  the  wild  plant,  and  is  brought  from  St.  Domingo. 

A  third  sort,  which  comes  from  Brazil,  is  the  vanillon,  or  large  vanilla  of  the  French 
market ;  the  vanilla  pampiona  or  bova  of  the  Spaniards.  Its  length  is  from  5  to  6  inches; 
its  breadth  from  one  half  to  three  quarters  of  an  inch.  It  is  brown,  soft,  viscid,  almost 
always  open,  of  a  strong  smell,  but  less  agreeable  than  the  leq.  It  is  sometimes  a  little 
spoiled  by  an  incipient  fermentation.  It  is  cured  with  sugar,  and  enclosed  in  tin-plate 
boxes,  which  contain  from  20  to  60  pods. 

Vanilla,  as  an  aromatic,  is  much  sought  after  by  makers  of  chocolate,  ices,  and  creams; 
by  confectioners,  perfumers,  and  liquorists,  or  distillers.  It  is  difficultly  reduced  to  fine 
particles ;  but  it  may  be  sufficiently  attenuated  by  cutting  it  into  smadl  bits,  and  grinding; 
these  along  with  sugar.  The  odorous  princi|)le  can,  for  some  purposes,  be  extracted  by 
alcohol.  Their  analysis  by  Bucholz  is  unsatisfactory,  and  refers  obviously  to  the  coarsest 
sort.     Berzelius  says  that  the  efflorescences  are  not  acid. 

VAPOR  (^Vapeur,  Fr. ;  Dampf,  Germ.),  is  the  state  of  elastic  or  aeriform  fluidity 
into  which  any  substance,  naturally  solid  or  liquid  at  ordinary  temperatures,  may  be 
coiiverttd  by  the  agency  of  heat.     See  Evaporation. 

VARXISH  {Vtniis,  Fr. ;  Fimiss,  Germ.),  is  a  solution  of  resinous  matter,  which  is 
spread  over  the  surface  of  any  body,  in  order  to  give  it  a  shining,  transparent,  and  hard 
coat,  capable  of  resisting,  in  a  greater  or  less  degree,  the  influences  of  air  and  moisture. 
Such  a  coat  consists  of  the  resinous  parts  of  the  solution,  which  remain  in  a  thin  layer 
upon  the  surface,  after  the  liquid  solvent  has  either  evaporated  away,  or  has  dried  op. 
When  large  quantities  of  spirit  varnish  are  to  be  made,  a  common  still,  mounted  with  iU 
capital  and  worm,  is  the  vessel  employed  for  containing  the  materials,  and  it  is  placed  in  a 
steam  or  water  bath.  The  capital  should  be  provided  with  a  stuffing-box,  through  which 
a  stirring-rod  may  pass  down  to  the  bottom  of  the  still,  with  a  cross-piece  at  its  lower 
end,  and  a  handle  or  winch  at  its  top.  After  heating  the  bath  till  the  alcohol  boils  and 
begins  to  distil,  the  heat  ought  to  be  lowered,  that  the  solution  may  continue  to  proceed 
in  an  equable  manner,  with  as  little  evaporation  of  spirit  as  possible.  The  operation  may 
be  supposed  to  be  complete  when  the  rod  can  be  easily  turned  round.  The  varnish  must 
be  passed  through  a  silk  sieve  of  proper  fineness ;  then  filtered  through  porous  paper,  or 
allowed  to  clear  leisurely  in  stone  jare.  The  alcohol  which  has  come  over  should  be 
added  to  the  varnish,  if  the  just  proporli<!<5  of  the  resins  have  been  introduced  at  first 
The  following  are  reckoned  good  French  recipes  for  varnishes  : — 

Wliite  spirit  varnish. — Sandarach,  250  parts;  mastic  in  tears,  61 ;  elemi  resin,  32; 
turpentine  (Venice),  64 ;  alcohol,  of  85  per  cent.,  1000  parts  by  measure. 

The  turpentine  is  to  be  added  after  the  resins  are  dissolved.  This  is  a  brilliant 
varnish,  but  not  so  hard  as  to  bear  polishing. 

Varnish  for^  the  wood  toys  of  Spa.  Tender  copal,  75  parts ;  mastic,  12*5 ;  Venice 
turpentine,  6-5 ;  alcohol,  of  95  per  cent.,  100  parts  by  measure ;  water  ounces,  for  ex- 
ample, if  the  other  parts  be  taken  in  ounces. 

The  alcohol  must  be  first  made  to  act  upon  the  copal,  with  the  aid  of  a  little  oil  of 
lavender  or  camphor,  if  thought  fit ;  and  the  solution  being  passed  through  a  linen  cloth, 
the  mastic  must  be  introduced.  After  it  is  dissolved,  the  Venice  turpentine,  previously 
melted  in  a  water-bath,  should  be  added ;  the  lower  the  temperature  at  which  these 
operations  are  carried  on,  the  more  beautiful  will  the  varnish  be.  This  varnish  ought 
to  be  very  white,  very  drying,  and  capable  of  being  smoothed  with  pumice-stone  and 
polished. 

Varnish  for  certain  parts  of  carriages. — Sandarach,  190  parts;  pale  shellac,  95;  rosia, 
125;  turpentine,  190;  alcohol,  at  85  per  cent.,  1000  parts  by  measure. 

Varnish  for  cabinet-makers.— Pa.\e  shellac,  750  parts;  mastic,  64  ;  alcohol,  of  90  per 
cent.,  1000  parts  by  measure.  The  solution  is  made  in  the  cold,  with  the  aid  of  frequent 
stirring.    It  is  always  muddy,  and  is  employed  without  being  filtered. 

With  the  same  resins  and  proof  spirit  a  varnish  is  made  for  the  bookbinders  to  do  ovei 
their  morocco  leather. 

The  varnish  of  Watin,for  gilded  articles.— Gam  lac,  in  grain,  125  parts;  gamboge, 
125;  dragon's  blood,  125;  annotto,  125;  saflfron,  32.    Each  resin  must  be  dissolved  in 


882 


VARNISH. 


■ 


1000  parts  by  measnre,  of  alcohol  of  an  _. 

n»UewMhil,e  Jragon's  blood  «"da„l?,^  ^'iS*''  '«">  «W™te  tinctares  mast  U 

Almost  all  IZZ^TttZni'^'T^  -dissolv^rcopa^r  '"  "  """^  "' ^'™""='' 
«.pal,  before  adding  the  oil  of  tureen  n^K'T"'"''.'?  '»  """''ine  the  dryin^  oil  with  th. 
t»rpe„t.„e    „„bi„es  very  readUyTvUh  ?u  '  d  "'  '",  ""'  '!"'  "^  "islaken      Cl  „"  oU  of 

ra^t  Se""'  '""""'^^  '"  "  leSs  by'Sr'"r7'''  "«'.''«"e„s  the  vrrSi.:^  ""^ 
"rying  the  proporlioos  of  the  inTe,);.™..      .J"'^"-    "s  consistence  may  be  varie,)  h. 

d".^  "PO"  fe  walls  of  ^ereuLfel"  aT P^p^  i  teXT'fl'e^i'''^  «-?"-- 
The  Jfeshness  at  the  present 

ee  months.     The  magnesia  will  absorb  alJ  the  ac  J  li/^"'*''?  ^«  settle  for  at  least 

""^  **''**  *«d  mucilage  from  the  oil,  and 


VAllNISH.  883 

fill  to  the  bottom  of  the  cistern,  leaving  the  oil  clear  and  transparent,  and  fit  for  nae. 
Recollect,  when  the  oil  is  taken  out,  not  to  disturb  the  bottoms,  which  are  only  fit  foi 
black  paint. 

GENERAL  OBSERVATIONS  AND  PRECAUTIONS  TO  BE  OBSERVED  IN  MAKING  VARNISHES. 

Set  on  the  boiling-pot  with  8  gallons  of  oil ;  kindle  the  fire ;  then  lay  the  fire  in  the 
gum-furnace;  have  as  many  81b.  bags  of  gum-copal  all  ready  weighed  up,  as  will  be 
wanted;  put  one  81b.  into  the  pot,  put  fire  to  the  furnace,  set  on  the  gum-pot;  in  three 
minutes  (if  the  fire  is  brisk)  the  gum  will  begin  to  fuse  and  give  out  its  gas,  steam,  and 
acid;    stir  and  divide  the  gum,  and  attend  to   the  rising  of  it,  as  before   directed. 
Eight  pounds  of  copal  take  in  general  from  sixteen  to  twenty  minutes  in  fusing,  from  the 
beginning  till  it  gets  clear  like  oil,  but  the  time  depends  very  much  on  the  heat  of  the 
fire,  and  the  attention  of  the  operator.     During  the  first  twelve  minutes,  while  the  gum 
is  fusing,  the  assistant  must  look  to  the  oil,  and  bring  it  to  a  smart  simmer ;  for  it  ought 
to  be  neither  too  hot,  nor  yet  loo  cold,  but  in  appearance  beginning  to  boil,  which  he 
is  strictly  to  observe,  and,  when  ready,  to  call  out,  "  Bear  a  hand  !"    Then  immediately 
both  lay  hold  of  a  handle  of  the  boiling-pot,  lift  it  right  up,  so  as  to  clear  the  plate, 
carry  it  out  and  place  it  on  the  ash-bed,  the  maker  instantly  returning  to  the  gum-pot, 
while  the  assistant  puts  three  copper  ladlefiils  of  oil  into  the  copper  pouring-jack, 
bringing  it  in  and  placing  it  on  the  iron  plate  at  the  back  of  the  gum-pot  to  keep  hot 
until  wanted.     When  the  maker  finds  the  gum  is  nearly  all  completely  fused,  and  that 
it  will  in  a  few  minutes  be  ready  for  the  oil,  let  him  call  out,  "  Ready  oil  !'*     The  assist- 
ant is  then  to  lift  up  the  oil-jack  with  both  hands  ;  one  under  the  bottom  and  the  other 
on  the  handle,  laying  the  spout  over  the  edge  of  the  pot,  and  wait  until  the  maker  calls 
out,  "  Oil !"     The  assistant  is  then  to  pour  in  the  oil  as  before  directed,  and  the  boiling 
to  be  continued  until  the  oil  and  gum   become  concentrated,  and  the  mixture  looks 
clear  on  the  glass;    the  gum   pot  is  now  to   be  set   upon    the  brick-stand  until  the 
assistant  puts  three  more  ladlefuls  of  hot  oil  into  the  pouring-jack,  and  three  more  into 
a  spare  tin  for  the  third  run  of  gum.     There  will  remain  in  the  boiling-pot  still  3| 
gallons  of  oil.    Let  the  maker  put  his  right  hand  down  the  handle  of  the  gum-pot  near 
to  the  side,  with  his  left  hand  near  the  end  of  the  handle,  and  with  a  firm  grip  lift  the 
gum-pot,  and  deliberately  lay  the  edge  of  the  gum-pot  over  the  edge  of  the  boiling-pot 
until  all  its  contents  run  into  the   boiling  pot.     Let  the   gum-pot    be  held,  with  its 
bottom  turned  upwards,  for  a  minute  right  over  the  boiling-pot.     Observe,  that  when- 
ever the  maker  is  beginning  to  pour,  the  assistant  stands  ready  with  a  thick  piece  of 
old  carpet,  without  holes,  and   sufficiently  large  to  cover  the  mouth  of  the  boiling-pot 
should  it  catch  fire  during  the  pouring,  which  will  sometimes  happen  if  the  gum-pot  is 
very  hot ;  should  the  gum-pot  fire,  it  has  only  to  be  kept  bottom  upwards,  and  it  will 
go  out  of  itself;  but  if  the  boiling-pot  should  catch  fire,  during  the  pouring,  let  the 
assistant  throw  the  piece  of  carpet  quickly  over  the   blazing  pot,  holding  it  down  all 
round  the  edges  ;   in  a  few  minutes  it  will  be  smothered.     The  moment  the  maker  has 
emptied  the  gum-pot,  he  throws  into  it  half  a  gallon  of  turpentine,  and  with  the  sivish 
immediately  washes  it  from  top  to  bottom,  and  instantly  empties  it  into  the  flat  tin  jack  : 
he  wipes  the  pot  dry,  and  puts  in  8  pounds  more  gum,  and  sets  it  upon  the  furnace ;  pro- 
ceeding with  this  run  exactly  as  with  the  last,  and  afterwards  with  the  third  run. 
There  will  then  be  8  gallons  of  oil  and  24  pounds  of  gum  in  the  boiling-oot,  under  which 
keep  up  a  brisk  strong  fire  until  a  scum  or  froth  rises  and  covers  allthe  surface  of  the 
contents,  when  it  will  begin  to  rise  rapidly.     Observe,  when  it  rises  near  the  rivets  of 
the  handles,  carry  it  from  the  fire,  and  set  it  on  the  ash-bed,  stir  it  down  again,  and 
scatter  in  the  driers  by  a  little  at  a  time ;  keep  stirring,  and  il   the  frothy  head  goes 
down,  put  it  upon  the  furnace,  and  introduce  gradually  the  remainder  of  the  driers, 
always  carrying  out  the  pot  when  the  froth  rises  near  the"  rivets.     In  general,  if  the  fire 
be  good,  all  the  time  a  pot  requires  to  boil,  from  the  time  of  the  last  gum  being  poured 
in,  is  about  three  and  a  half  or  four  hours ;  but  time  is  no  criterion  for  a  beginner  to 
ju^dge  by,  as  it  may  vary  according  to  the  weather,  the  quality  of  the  oil,  the  quality  of 
the  gum,  the  driers,  or  the  heat  of  the  fire,  &c.;  therefore,  about  the  third  hour  of 
boihng,  try  it  on  a  bit  of  glass,  and  keep  it  boiling  until  it  feels  strong  and  stringy  be- 
tween the  fingers;  it  is  then  boiled  sufficiently  to  carry  it  on  the  ash-bed,  and  to  be  stirred 
down  until  it  is  cold  enough  to  mix,  which  will  depend  much  on  the  weather,  vary- 
ing from  half  an  hour,  in  dry  frosty  weather,  to  one  hour  in  warm  summer  weather. 
Previous  to  beginning  to  mix,  have  a  sufficient  quantity  of  turpentine  ready,  fill  the 
pot,  and  pour  in,  stirring  all  the  time  at  the  top  or  surface,  as  before  directed,  until 
there  are  fifteen  gallons,  or  five  tins  of  oil  of  turpentine  introduced,  which  will  leave  it 
quite  thick  enough  if  the  gum  is  goo«l,  and  has  been  well  run;  but  if  the  gum  was  of 
a  weak  quality,  and  has  not  been  well  fused,  there  ought  to  be  no  more  than  twelve 
gallons  of  turpentine  mixed,  and  even  thai  may  be  too  much.     Therefore,  when  twelve 
gallons  of  turpentine  have  been  introdused,  have  a  flat  saucer  at  hand,    ad  pour  into  it 


884 


VARNrSH. 


a  portion  of  the  varnish,  and  in  two  or  three  minutes  it  will  show  whether  it  is  too 
thick ;  if  not  sufficiently  thin,  add  a  little  more  turpentine,  and  strain  it  ofl"  quickly. 
As  soon  as  the  whole  is  stored  away,  pour  in  the  turpentine  washings,  with  which  the 
gum-pots  have  been  washed,  into  the  boiling-pot,  and  with  the  swish  quickly  wash 
down  all  the  varnish  from  the  pot  sides ;  afterwards,  with  a  large  piece  of  woollen  rag 
dipped  in  pumice-powder,  wash  and  polish  every  part  of  the  inside  of  the  boiling-pot, 
performing  the  same  operation  on  the  ladle  and  stirrers ;  rinse  them  with  the  turpen- 
tine washings,  and  at  last  rinse  them  altogether  in  clean  turpentine,  which  also  put  to 
the  washings ;  wipe  dry  with  a  clean  soft  rag  the  pot,  ladle,  stirrer,  and  funnels,  and 
lay  the  sieve  so  as  to  be  completely  covered  with  turpentine,  which  will  always  keep  it 
Irom  gumming  up.     The  foregoing  directions  concerning  running  the  gum,  and  pouring 
in  the  oil,  and  also  boiling  ofl'  and  mixing,  are,  with  very  little  difference,  to  be  observed 
in  the  making  of  all  sorts  of  copal  varnishes,  except  the  differences  of  the  quantities  of 
oil,  gum,  &c.,  which  will  be  found  under  the  various  descriptions  by  name,  which  will  be 
hereafter  described. 

The  choice  of  linseed  oil  is  of  peculiar  consequence  to  the  varnish-maker.  Oil  from 
fine  full-grown  ripe  seed,  when  viewed  in  a  vial,  will  appear  limpid,  pale,  and  brilliant; 
it  is  mellow  and  sweet  to  the  taste,  has  very  little  smell,  is  specifically  lighter  than  im- 
pure oil,  and,  when  clarified,  dries  quickly  and  firmly,  and  does  not  materially  change  the 
color  of  the  varnish  when  made,  but  appears  limpid  and  brilliant. 

Copal  varnishes  for  fine  paintings^  ^c. — Fuse  8  pounds  of  the  very  cleanest  pale  African 
gum  copal,  and,  when  completely  run  fluid,  pour  in  two  jjallons  of  hot  oil,  old  measure; 
let  it  boil  until  it  will  string  very  strong;  and  in  about  fifteen  minutes,  or  while  it  is 
yet  very  hot,  pour  in  three  gallons  of  turpentine,  old  measure,  and  got  from  the  top  of 
a  cistern.  Perhaps,  during  the  mixing,  a  considerable  quantity  of  the  turpentine  will 
escape  ;  but  the  varnish  will  be  so  much  the  brighter,  transparent,  and  fluid;  and  will  work 
freer,  dry  more  quickly,  and  be  very  solid  and  durable  when  dry.  After  the  varnish  has 
been  strained,  if  it  is  fbund  too  thick,  before  it  is  quite  cold,  heat  as  much  turpentine,  and 
mix  with  it,  as  will  bring  it  to  a  proper  consistence. 

Cabinet  varnish — Fuse  7  pounds  of  very  fine  African  gum  copal,  and  pour  in  half  a 
gallon  of  pale  clarified  oil ;  in  three  or  four  minutes  after,  if  it  feel  stringy,  take  it  out 
of  doors,  or  into  another  building  where  there  is  no  fire,  and  mix  with  it  three  gallons 
of  turpentine ;  afterwards  strain  it,  and  put  it  aside  for  use.  This,  if  properly  boiled, 
will  dry  in  ten  minutes ;  but  if  too  strongly  boiled,  will  not  mix  at  all  with  the  turpen- 
tine; and  somefiines,  when  boiled  with  the  turpentine,  will  mix,  and  yet  refuse  to  incor- 
porate with  any  other  varnish  less  boiled  than  itself:  therefore  it  requires  a  nicety  which 
is  only  to  be  learned  from  practice.  This  varnish  is  chiefly  intended  for  the  use  of  ja- 
panners,  cabinet-painters,  coach-painters,  &c. 

Best  body  copal  varnish  for  coach-makersy  4rc. — This  is  intended  for  the  body  parts  of 
coaches  and  other  similar  vehicles,  intended  for  polishing. 

Fuse  8  lbs.  of  fine  African  gum  copal ;  add  two  gallons  of  clarified  oil  (old  measure)  ; 
boil  it  very  slowly  for  four  or  five  hours,  until  quite  stringy;  mix  with  three  gallons  and 
a  half  of  turpentine  ;  strain  off,  and  pour  it  into  a  cistern.  As  they  are  too  slow  in  dry- 
ing, coach-makers,  painters,  and  varnish-makers,  have  introduced  to  two  pots  of  the  ore- 
ceding  varnish,  one  made  as  follows : — 

8  lbs.  of  fine  pale  gum  animej  I      3h  gallons  of  turpentine. 

2  gallons  of  clarified  oil;  (        "To  be  boiled  four  hours. 

Quick  drying  hodg  copal  varnish,  for  coaches,  ^c. 


(1.)  8  lbs.  of  the  best  African  copal ; 
2  gallons  of  clarified  oil ; 
J  lb.  of  dried  sugar  of  lead; 
3|  gallons  of  turpentine. 

Boiled    till  stringy,  and  mixed  and 

strained. 

To  be  mixed  and  strained  while  hot  into  the  other  pot.  These  two  pots  mixed  togetn«» 
will  dry  in  six  hours  in  winter,  and  in  four  in  summer ;  it  is  very  useful  for  varnishlBf 
old  work  on  dark  colors,  &c. 


(2.)  8  lbs.  of  fine  gum  anime; 
2  gallons  of  clarified  oil ; 
\  lb.  of  white  copperas ; 
3§  gallons  of  turpentine. 
Boiled  as  before. 


Best  pale  carriage  varnish, 

(1.)  8  lbs.  2d  sorted  African  copal; 
2|  gallons  of  clarified  oil. 
Boiled  till  very  stringy. 
I  lb.  of  dried  copperas ; 
J  lb.  of  litharge; 
5|  gallons  of  turpentine. 
Strained   ft.r.. 


(2.)  8  lbs.  of  2d  sorted  gum  anim^  { 
24  gallons  of  clarified  oil ; 
f  lb.  of  dried  sugar  of  lead  ; 
I  lb.  of  litharge; 
5^  gallons  of  turpentine. 
Mix  this  to  the  first  while  hot. 


VARNISH. 


885 


This  varnish  will  dry  hard,  if  well  boiled,  in  four  hours  in  summer,  and  in  six  ia  win. 
ler.  As  the  name  denotes,  it  is  intended  for  the  varnishing  of  the  wheels,  springs,  and 
carriage  parts  of  coaches,  chaises,  &c. ;  also,  it  is  that  description  of  varnish  which  is 
generally  sold  to  and  used  by  house-painters,  decorators,  &,c. ;  as  from  its  drying  quality 
an^.  strong  gloss,  it  suits  their  general  purposes  well. 


8  lbs.  of  2d  sorted  gum  anime ; 
2|  gallons  of  fine  clarified  oil ; 
5^  gallons  of  turpentine ; 
i  lb.  of  litharge ; 


Second  carriage  varnish. 


I  lb.  of  dried  sugar  of  lead; 
J  lb.  of  dried  copperas. 
Boiled'and  mixed  as  before. 


Wainscot  varnish. 


8  lbs.  of  2d  sorted  gum  anime ; 
3  gallons  of  clarified  oil ; 
i  lb.  of  litharge  j 
J  lb.  of  dried  sugar  of  lead ; 


5k  gallons  of  turpentine. 
To    be    well    boiled    until  it   strings 
very   strong,  and   then   mixed  and 
strained. 

Mahogany  varnish  is  made  either  with  the  same  proportions,  with  a  little  darker  gum ; 
otherwise  it  is  wainscot  varnish,  with  a  small  portion  of  gold  size. 

Black  japan  is  made  by  putting  into  the  set-pot  48  pounds  of  Naples,  or  any  other  of 
the  foreign  asphaltums,  (except  the  Egyptian.)  As  soon  as  it  is  melted,  pour  in  10  gal- 
lons of  raw  linseed  oil;  keep  a  moderate  fire,  and  fuse  8  pounds  of  dark  gum  anime  in 
tlie  gum-pot ;  mix  it  with  2  gallons  of  hot  oil,  and  pour  it  into  the  set-pot.  Afterwards 
fuse  10  pounds  of  dark  or  sea  amber  in  the  10  gallon  iron  pot;  keep  stirring  it  while 
fusing ;  and  whenever  it  appears  to  be  overheated,  and  rising  too  high  in  the  pot,  lift  it 
from  the  fire  for  a  few  minutes.  When  it  appears  completely  fused,  mix  in  2  gallons  of 
hot  oil,  and  pour  the  mixture  into  the  set-pot ;  continue  the  boiling  for  3  hours  longer, 
and  during  that  thne  introduce  the  same  quantity  of  driers  as  before  directed  ;  draw  out 
the  fire,  and  let  it  remain  until  morning ;  then  boil  it  until  it  rolls  hard,  as  before  directed  ; 
leave  it  to  cool,  and  afterwards  mix  with  turpentine. 

Pale  amber  varnish. — Fuse  6  pounds  of  fine  picked  very  pale  transparent  amber  in 
the  gum-pot,  and  pour  in  2  gallons  of  hot  clarified  oil.  Boil  it  until  it  strings  very  strong. 
Mix  with  4  gallons  of  turpentine.  This  will  be  as  fine  as  body  copal,  will  work  very 
free,  and  flow  well  upon  any  work  it  is  applied  to;  it  becomes  very  hard,  and  is  the  most 
durable  of  all  varnishes ;  it  is  very  excellent  to  mix  in  copal  varnishes,  to  give  them  a 
hard  and  durable  quality.  Observe;  amber  varnish  will  always  require  a  long  time  be- 
fore it  is  ready  for  polishing. 

Best  Brunswick  black. — In  an  iron  pot,  over  a  slow  fire,  boil  45  pounds  of  foreign 
asphaltum  for  at  least  6  hours ;  and  during  the  same  time  boil  in  another  iron  pot  6  gal- 
lons of  oil  which  has  been  previously  boiled.  During  the  boiling  of  the  6  gallons,  intro- 
duce 6  pounds'of  litharge  gradually,  and  boil  until  it  feels  stringy  between  the  fingers; 
then  ladle  or  pour  it  into  the  pot  containing  the  boiling  asphaltum.  Let  the  mixture  boil 
until,  upon  trial,  it  will  roll  into  hard  pills ;  then  let  it  cool,  and  mix  it  with  25  gallons  of 
turpentine,  or  until  it  is  of  a  proper  consistence. 

Iron-work  black. — Put  48  pounds  of  foreign  asphaltum  into  an  iron  pot,  and  boil  for 
4  hours.  During  the  first  2  hours,  introduce  7  pounds  of  red  lead,  7  pounds  of  litharge, 
3  pounds  of  dried  copperas,  and  10  gallons  of  boiled  oil ;  add  1  eight-pound  run  of  dark 
gum,  with  2  gallons  of  hot  oil.  After  pouring  the  oil  and  gum,  continue  the  boiling  two 
hours,  or  until  it  will  roll  into  hard  pills  like  japan.  When  cool,  thin  it  off  with  thirty 
gallons  of  turpentine,  or  until  it  is  of^a  proper  consistence.  This  varnish  is  intended  for 
blacking  the  iron-work  of  coaches  and  other  carriages,  &c. 

Jl  cheap  Brunswick  black. — Put  28  pounds  of  common  black  pitch,  and  28  pounds  of 
common  asphaltum  made  from  gas  tar,  into  an  iron  pot ;  boil  both  for  8  or  10  hours, 
which  will  evaporate  the  gas  and  moisture  ;  let  it  stand  all  night,  and  early  next  morn- 
ing; as  soon  as  it  boils,  put  in  8  gallons  of  boiled  oil ;  then  introduce,  gradually,  iO 
pounds  of  red  lead,  and  10  pounds  of  litharge,  and  boil  for  3  hours,  or  until  it  will  roll 
very  hard.  When  ready  for  mixing,  introduce  20  gallons  of  turpentine,  or  more,  until 
of  a  proper  consistence.  This  is  intended  for  engineers,  founders,  ironmongers,  &,c. ;  it 
will  dry  in  half  an  hour,  or  less,  if  properly  boiled. 

Jxioms  observed  in  the  making  of  copal  varnishes. — The  more  minutely  the  gum  is 
run,  or  fused,  the  greater  the  quantity,  and  the  stronger  the  produce.  The  more 
regular  and  longer  the  boiling  of  the  oil  and  gum  together  is  continued,  the  more  fluid 
or  free  the  varnish  will  extend  on  whatever  it  is  applied  to.  When  the  mixture  of  oil  and 
gum  is  too  suddenly  brought  to  string  by  too  strong  a  heat,  the  varnish  requires  more 
than  its  just  proportion  of  turpentine  to  thin  it,  whereby  its  oily  and  gummy  quality  is 
reduced,  which  renders  it  less  durable ;  neither  will  it  flow  so  well  in  laying  on.  The 
greater  proportion  of  oil  there  is  used  in  varnishes,  the  less  they  are  liable  to  crack, 
because  the  tougher  and  softer  they  are.    By  increasing  the  proportion  of  gum  in  varnishes, 


■p*' 


886 


VARNISH. 


the  thicker  -will  be  the  stratum,  the  firmer  they  will  set  solid,  and  the  quicker  they  will 
dry.  When  varnishes  are  quite  new  made,  and  must  be  sent  out  for  use  before  they  are 
of  sufficient  age,  they  must  always  be  left  thicker  than  if  they  were  to  be  kept  the  proper 
time.  Varnish  made  from  African  copal  alone  possesses  the  most  elasticity  and  transpa- 
rency. Too  much  driers  in  varnish  render  it  opaque  and  unfit  for  delicate  colors.  Cop- 
peras does  not  combine  with  varnish,  but  only  hardens  it.  Sugar  of  lead  does  combine 
with  varnish.  Turpentine  improves  by  age;  and  varnish  by  being  kept  in  a  warm  place. 
All  copal  or  oil  varnishes  require  age  before  they  are  used. 

Cmcluding  observaliom,—A\\  body  varnishes  are  intended  and  ought  to  have  l\  lbs.  cf 
gum  to  each  gallon  of  varnish,  when  the  varnish  is  strained  off,  and  cold ;  but  as  the  thin- 
ning  up,  or  quantity  of  turpentine  required  to  bring  it  to  its  proper  consistence,  depends 
verj'  much  upon  the  degree  of  boiling  the  varnish  has  undergone,  therefore,  when  Ihe  gum 
and  oil  have  not  been  strongly  boiled,  it  requires  less  turpentine  for  that  purpose ;  whereas, 
when  ihe  gum  and  oil  are  very  strongly  boiled  together,  a  pot  of  20  gallons  will  require 
perhaps  3  gallons  above  the  regular  proportionate  quantity  ;  and  if  mixin?  the  turpentine 
is  commenced  too  soon,  and  the  pot  not  sufficiently  cool,  there  will  be  frequently  above  a 
gallon  and  a  half  of  turpentine  lost  by  evaporation. 

All  carriage,  wainscot,  and  mahogany  varnish  ought  to  have  fully  one  pound  of  gum  for 
each  gallon,  when  strained  and  cold ;  and  should  one  pot  require  more  than  its  proportion 
of  turpentine,  the  following  pot  can  easily  be  leA  not  quite  so  strongly  boiled ;  then  it 
will  require  less  turpentine  to  thin  it  up. 

Gold  sizes,  whether  pale  or  dark,  ought  to  have  fully  half  a  pound  of  good  gum  copal  to 
each  gallon,  when  it  is  finished  ;  and  the  best  black  japan,  to  have  half  a  pound  of  eood 
gum,  o>  upwards,  besides  the  quantity  of  asphaltum. 

Fine  mattic,  or  picture  varnish. — Put  5  pounds  of  fine  picked  gum  mastic  into  a  new 
four-gallon  tin  botile;  get  ready  2  pounds  of  glass,  bruised  as  small  as  barley;  wash  it 
several  times;  afterwards  dry  it  perfectly,  and  put  it  into  the  bottle  with  2  gallons  of  tur- 
pentine that  has  settled  some  time ;  put  a  piece  of  soft  leather  under  the  bung ;  lay  the 
tin  on  a  sack  upon  ihe  counter,  table,  or  any  thing  that  stands  solid ;  begin  to  agitate  the 
tin,  smartly  rolling  it  backward  and  forward,  causing  the  gum,  glass,  and  turpentine,  to 
work  as  if  in  a  barrel  churn  for  at  least  4  hours,  when  the  varnish  may  be  emptied  out  into 
any  thing  sufficiently  clean,  and  large  enough  to  hold  it.  If  the  sum  is  not  all  dissolved, 
return  the  whole  into  the  bottle,  and  agitate  as  before,  until  all  the  gum  is  dissolved ; 
then  strain  it  through  fine  thin  muslin  into  a  clean  tin  botile:  leave  it  uncorked,  so  that 
the  air  can  get  in,  but  no  dust ;  let  it  stand  for  9  months,  at  least,  before  it  is  userl ;  for 
the  longer  it  is  kept,  the  tougher  it  will  be,  and  less  liable  to  chill  or  bloom.  To  prevent 
mastic  varnish  from  chillins,  boil  one  quart  of  river  sand  with  two  ounces  of  pearl-ashes; 
afterwards  wash  the  sand  three  or  four  times  with  hot  water,  straining  it  each  time ;  put 
the  sand  on  a  soup-plate  to  dry,  in  an  oven ;  and  when  it  is  of  a  good  heat,  pour  half  a 
pint  of  hot  sand  into  each  gallon  of  varnish,  and  shake  it  well  for  five  minutes;  it  will 
soon  settle,  and  carry  down  the  moisture  of  the  gum  and  turpentine,  which  is  the  general 
cause  of  mastic  varnish  chilling  on  paintings. 

Common  mastic  varnish. — Put  as  much  gum  mastic,  unpicked,  into  the  gurn-pot  as  may 
be  required,  and  to  every  2f  pounds  of  ?um  pour  in  1  gallon  of  cold  turpentine ;  set  the 
pot  over  a  very  moderate  fire,  and  stir  it  with  the  stirrer;  be  careful,  when  the  steam  of 
the  turpentine  rises  near  the  mouth  of  the  pot,  to  cover  it  with  the  carpet,  and  carry  it 
out  of  doors,  as  the  vapor  is  very  apt  to  catch  fire.  A  few  minutes'  low  h^eat  will  perfectly 
dissolve  8  pounds  of  gum,  which  will,  with  4  gallons  of  turpentine,  produce,  when  strain- 
ed, 4^  gallons  of  varnish;  to  which  add,  while  yet  hot,  5  pints  of  pale  turpentine  varnish, 
which  improves  the  body  and  hardness  of  the  mastic  varnish. 

Crystal  varnish,  may  he  made  either  in  the  varnish-house,  drawing-room,  or  parlor. 
Procure  a  bottle  of  Canada  balsam,  which  can  be  had  at  any  druggist's ;  draw  out  the 
cork,  and  set  the  botile  of  balsam  at  a  little  distance  from  the  fire,  turning  it  round  several 
times,  until  the  heat  has  thinned  it ;  then  have  something  that  will  hold  as  much  as  double 
the  quantity  of  balsam ;  carry  the  balsam  from  the  fire,  and,  while  fluid,  mix  it  Jvith  the 
same  quantity  of  good  turpentine,  and  shake  them  together  until  they  are  well  incorpora- 
ted; in  a  lew  days  the  varnish  is  fit  for  use,  particularly  if  it  is  poured  into  a  half-gallon 
glass  or  stone  bottle,  and  kept  in  a  gentle  warmth.  This  varnish  is  used  for  maps,  prints, 
charts,  drawings,  paper  ornaments,  &c. ;  and  when  made  upon  a  larger  scale,  requires 
only  warming  the  balsam  to  mix  with  the  turpentine. 

White  hard  spirit-of-wine  varnish.— ?ui  5  pounds  of  gum  sandarach  into  a  four-gallon 
tin  bottle,  with  2  gallons  of  spirits  of  wine,  60  over  proof,  and  agitate  it  until  dissolved, 
exactly  as  directed  for  the  best  mastic  varnish,  recollecting,  if  washed  glass  is  used,  that 
it  is  convenient  to  dip  the  bottle  containing  the  gum  and  spirits  into  a  copperful  of  hot 
water  every  10  minutes— the  bottle  to  be  immersed  only  2  minutes  at  a  time— which  will 
greatly  assist  the  dissolving  of  the  gum  ;  but,  above  all,  be  careful  to  keep  a  firm  hold 
over  the  cork  of  the  bo»»le,  otherwise  the  rarefaction  will  drive  the  cork  out  with  tbt 


VARNISH. 


887 


foice  of  a  shot,  and  perhaps  set  fire  to  the  place.  The  bottle,  every  time  it  is  heated, 
ought  to  be  carried  away  from  the  fire ;  the  cork  should  be  eased  a  little,  to  allow  the 
rarefied  air  to  escape ;  then  driven  tight,  and  the  agitation  continued  in  this  manner 
until  all  the  gum  is  properly  dissolved;  which  is  easily  known  by  having  an  empty  tin 
can  to  pour  the  varnish  into,  until  near  the  last,  which  is  to  be  poured  into  a  gallon  mea- 
sure. If  the  gum  is  not  all  dissolved,  leturn  the  whole  into  the  four-gallon  tin,  and  con- 
tinue the  agitation  until  it  is  ready  to  be  strained,  when  every  thing  ought  to  be  quite 
ready,  and  perfectly  clean  and  dry,  as  oily  fins,  funnels,  strainers,  or  any  thing  damp,  or 
even  cold  weather,  will  chill  and  spoil  the  varnish.  After  it  is  strained  off,  put  into  the 
varnish  one  quart  of  very  pale  turpentine  varnish,  and  shake  and  mix  the  two  well 
together.  Spirit  varnishes  should  be  kept  well  corked ;  they  are  fit  to  use  the  day  after 
being  made. 

Brown  hard  spirit  varnish,  is  made  by  putting  into  a  bottle  3  pounds  of  gum  sandarach, 
with  2  pounds  of  shellac,  and  2  gallons  of  spirits  of  wine,  60  over  proof;  proceeding 
exactly  as  before  directed  for  the  white  hard  varnish,  and  agitating  it  when  cold,  which 
requires  about  4  hours*  time,  without  any  danger  of  fire;  whereas,  making  any  spirit 
varnish  by  heat  is  always  attended  with  danger.  No  spirit  varnish  ought  to  be  made 
either  near  a  fire  or  by  candle  light.  When  this  brown  hard  is  strained,  add  one  quart  of 
turpentine  varnish,  and  shake  and  mix  it  well :  next  day  it  is  fit  for  use. 

The  Chinese  varnish,  comes  from  a  tree  which  grows  in  Cochin-China,  China,  and 
Siam.     It  forms  the  best  of  all  varnishes. 

Gold  lacker. — Put  into  a  clean  four-gallon  tin,  1  pound  of  ground  turmeric,  1|  ounces 
of  powdered  gamboge,  3|  pounds  of  powdered  gum  sandarach,  f  of  a  pound  of  shellac,  and 
2  gallons  of  spirits  of  wine.  After  being  agitated,  dissolved,  and  strained,  add  1  pint  ol 
turpentine  varnish,  well  mixed. 


Red  spirit  lacker. 

2  gallons  of  spirits  of  wine ; 

1  pound  of  dragoi's  blood; 

3  pounds  of  Spanish  annotto ; 
3|  pounds  of  gum  sandarach; 

2  pints  of  turpentine. 

Made  exactly  as  the  yellow  gold  lacker. 


Pale  brass  lacker, 

2  gallons  of  spirits  of  wine ; 

3  ounces  of  Cape  aloes,  cut  small ; 
I  pound  of  fine  pale  shellac ; 

1  ounce  gamboge,  cut  small. 
No  turpentine  varnish.     Made  exactly 
before. 


as 


But  observe,  that  those  who  make  lackers,  frequently  want  some  paler,  and  some  darker, 
and  sometimes  inclining  more  to  the  particular  tint  of  certain  of  the  component  ingredir 
ents.  Therefore,  if  a  four-ounce  vial  of  a  strong  solution  of  each  ingredient  be  prepared, 
a  lacker  of  any  tint  can  be  produced  at  any  time. 

Preparation  of  linseed  oil  for  making  varnishes. — Put  25  gallons  of  linseed  oil  into  an 
iron  or  copper  pot  that  will  hold  at  least  30  gallons;  put  a  fire  under,  and  gradually  in- 
crease the  heat,  so  that  the  oil  may  only  simmer,  for  2  hours ;  during  that  time  the  great- 
est part  of  its  moisture  evaporates;  if  any  scum  arises  on  the  surface,  skim  it  off,  and 
put  that  aside  for  inferior  purposes.  Then  increase  the  fire  gradually,  and  sprinkle  in, 
by  a  little  at  a  lime,  3  lbs.  of  scale  litharge,  3  lbs.  of  good  red  lead,  and  2  lbs.  of  Turkey 
umber,  all  well  dried  and  free  from  moisture.  If  any  moist  driers  are  added,  they  will 
cause  the  oil  to  tumefy ;  and,  at  the  same  time,  darken  it,  causing  it  to  look  opaque  and 
thick,  ropy  and  clammy,  and  hindering  it  from  drying  and  hardening  in  proper  time ;  be- 
sides, it  will  lie  on  the  working  painting  like  a  piece  of  bladder  skin,  and  be  very  apt  to 
rise  in  blisters.  As  soon  as  all  the  driers  are  added  to  the  oil,  keep  quietly  stirring  the 
driers  from  the  bottom  of  the  pot ;  otherwise  they  will  burn,  which  will  cause  the  oil  to 
blacken  and  thicken  before  it  is  boiled  enough.  Let  the  fire  be  so  regulated  that  the  oil 
shall  only  boil  slowly  for  three  hours  from  the  time  all  the  driers  were  added;  if  it  then 
ceases  to  throw  up  any  scum,  and  emits  little  or  no  smoke,  it  is  necessary  to  test  its  tem- 
perature by  a  few  quill  tops  or  feathers.  Dip  a  quill  top  in  the  oil  every  two  minutes, 
for  when  the  oil  is  boiled  enough,  the  quill  top  will  crackle  or  curl  up  quite  burnt;  if  so, 
draw  out  the  fire  immediately,  and  let  the  oil  remain  in  the  pot  at  least  from  10  to  24 
hours,  or  longer  if  convenient,  for  the  driers  settle  much  sooner  when  the  oil  is  It  ft  to 
cool  in  the  pot,  than  when  it  is  immediately  taken  out. 

Poppy  oil. — Into  four  pints  of  pure  soft  water,  put  two  ounces  of  foreign  white  vitriol  g 
warm  the  water  in  a  clean  copper  pan,  or  glazed  earthen  jar,  until  the  vitriol  is  dissolv- 
ed ;  pour  the  mixture  into  a  clean  glass  or  stone  bottle,  large  enough  to  contain  three 
gallons;  then  add  to  the  solution  of  vitriol  one  gallon  and  a  half  of  poppy  oil,  cork  and 
agitate  the  bottle  regularly  and  smartly  for  at  least  two  hours ;  then  pour  out  the  contents 
into  a  wide  earthenware  dish :  leave  it  at  rest  for  eight  days,  when  the  oil  will  be  clea» 
and  brilliant  on  the  surface,  and  may  be  taken  off  with  a  spoon  or  flat* skimmer,  and  pu* 
up  in  a  glass  bottle  and  exposed  to  the  light,  which  in  a  few  weeks  renders  the  oil  exceed- 
ingly limpid  and  colorless. 


888 


VENTILATION. 


VENTILATION. 


889 


iVi<^o^/  or  oil  of  walnutu,  is  extracted  by  expression ;  and  that  which  is  extracted 
without  healv  is  certainly  the  most  pale,  pure,  and  nutritive  seasoning,  and  retains  an 
exquisite  taste  of  the  fruit  That  designed  for  the  arts  is  of  inferior  quality,  and  is 
plentifully  imported  to  us  from  France;  the  heat  it  undergoes  in  its  ton-efaction,  pre- 
vious to  its  expression,  disposes  it  to  dry  more  quickly  than  that  expressed  by  the  cold 
process;  but,  at  the  same  time,  the  heat,  though  it  frees  it  from  its  unctuous  quality 
gives  It  more  color.  When  it  has  been  extracted  by  the  cold  process,  it  may  be  pre- 
pared m  the  same  way  as  directed  for  the  poppy  oil. 

In  the  above  article  I  have  retained  the  workmen's  names— gum,  white  vitriol  Ac. 
instead  of  resin,  sulphate  of  zinc,  <fec.  '       * 

VARNISH ;  Green.  Grind  Chinese  blue  with  double  the  quantity  of  finely  pow- 
dered chromate  of  potash  and  copal  varnish,  thinned  with  turpentine.  The  proportions 
of  blue  and  chromate  may  be  varied.  This  varnish  produces  a  striking  effect  on 
japanned  goods,  Ac.  , 

VEGETABLE  ACIDS.  The  terra  vegetable  is  now  nearly  superseded  by  the  word 
or^ran^r,  though  the  distinction  must  always  be  maintained  between  acids  of  animal  and 
vegetable  origin. 

The  following  are  the  most  prominent  vegetable  acids. 


Aconitic 

Acrylic 

Benzilic 

Benzoic 

Bilic 

Boletic 

Campholie 

Camphoric 

Carbolic 

Cevadic 

Chelidonic 

Cinnamic 

Citraconic 


Citric 

Cocinio 

Cominic 

Coumarie 

Cuminio 

Ellagic 

Erytliric 

Fumaric 

Fungi  c 

Gallic 

Hippuric 

Isatic 

Itaconic 


Krameric 

Lactic 

Meconic 

Metagallic 

Mucic 

Nitro-picric 

(Enanthic 

Para  tartaric 

Peetic 

Pyrocitric 

Pyrogallic 

Pyrotartaric 

Quinic 


Racemic 

Roccellic 

Sacchario 

Suberic 

Succinic 

Tannic 

Tartaric 

Tartralic 

Tartrelic 

Valeric 

Veratric 

Xanthic 


4!i7?^^^  (i^/on«,  Fr.;  Gauge,  Germ.);  are  the  fissures  or  rents  in  rocks,  which  are 
filled  with  peculiar  mineral  substances,  most  commonly  metallic  ores. 

VEIN  STONES,  or  GANGUES,  are  the  mineral  substances  which  accompany,  and 
frequently  enclose,  the  metallic  ores. 

VELLUM,  is  a  fine  sort  of  Parchment,  which  see. 

VELVET  ( r<?^Mr«,  Fr.;  Sammet,  Germ.);  a  peculiar  stuflF,  the  nature  of  which  is 
explained  under  Fustian  and  Textile  Fabrics. 

VENETIAN  CHALK,  is  Steatite. 

VENTILATION,  or  the  renewal  of  fresh  air  in  stajjnant  places,  is  nowhere  exhibited 
to  such   advantage   as  m  the   coal   mines  of   Northumberland   and    Durham,  where 
Mr.  Huddle  has  earned  well  nigh  to  systematic  perfection  the  plan  of  coursin«'  the 
air  through  the  winding  galleries,  originally  contrived  about  the  year  1760,  by  Mr.  James 
Speddmg,  of  Workmglon,  the  ablest  pitman  of  his  day.*    He  converted  the  whole  of 
the  passages  into  air-pipes,  so  to  speak,  drew  the  current  of  air  from  the  downcast  pit, 
then  traversed  it  up  and  down,  and  round  about,  through  the  several  sheaths  of  the 
workings,   so    that    no    particular  gallery    was   left    without  a    current    of    air.      He 
thereby    succeeded  in   actually    expelling  the  noxious   gases  from  the  mines;     those 
demons,  which  m  Germany,  at  no  remote  era,  were  wont  to  be  combated  bv  the  priests 
with  impotent  exorcisms  or   pious  frauds.        Before  Mr.    Buddie   introduced   his   im- 
provements, he  has  known  the  air  to  be  led  through  a  series  of  workings,  thirty  miles 
long,  before  It  made  Us  exit.     There  is  in  every  coal  mine  an  experienced  corps,  called 
wastemen   because  they  travel  over  the  waste,  or  the  exhausted  regions,  who  can  tell  at 
once,  by  the  whistling  sound  which  the  air  makes  at  the  crevices  in  certain  partitions  and 
doors,  whether  the  ventilation  he  in  good  condition  or  not.     They  hear  these  stoppings 
begin  to  *i«-or  ca//,  as  they  say,  whenever  an  interruption  lakes  place  in  any  point  of  the 
jabyrinthian  line.     Another  indication  of  something  being  wrong,  is  when  the  doors  get  so 
heavy,  that  the  boys  in  attendance  upon  them  find  them  difficult  to  shut  or  open.    The 
instant  such  a  defect  is  discovered  by  any  one,  he  cries  aloud,  «  Holloa,  there  is  something 
wrong — the  doors  are  calling  !"  ° 

In  Mr.  Spedding's  system,  the  whole  of  the  return  air  came  in  one  current  to  his 
rar^fyin?  furnace  (see  letter  c.fig.  1158),  whether  it  was  at  the  explosive  point  or  not 
This  distribution  was  often  fraught  with  such  danger,  that  a  torrent  of  water  had  to  he 

hi8*i^irii)"^  engineers  uae  the  term  good  pUman,  aa  admirala  do  good  seaman,  to  denote  a  proficient  in 


kept  in  readiness,  under  the  name  of  the  waterfall,  to  be  let  down  to  extinguish  the  fire 
in  a  moment  Many  explosions  at  that  time  occurred,  from  the  furnaces  below,  and 
also  down  through  tubes  from  the  furnaces  above-ground. 

About  the  year  1807,  Mr.  Buddie  had  his  attention  intensely  occupied  with  this  most 
important  object,  and  then  devised  his  plan  of  a  divided  current,  carrying  that  portion 
through  the  active  furnace  c,fig.  1 158,  and  the  portion  of  the  air  from  the  foul  workings 
of  the  air  which,  descending  in  the  downcast  pit  a,  coursed  through  the  ctean  workings, 
up  the  dumb  furnace  d,  till  it  reached  a  certain  elevation  in  b,  the  upcast  pit,  above  the 
fireplace.  The  pitmen  had  a  great  aversion,  however,  at  first,  to  adopt  this  plan,  as  they 
thought  that  the  current  of  air,  by  being  split,  would  lose  its  ventilating  power ;  but 
they  were,  ere  long,  convinced  by  Mr.  Buddie  to  the  contrary.  He  divides  the  main 
current  into  two  separate  streams,  at  the  bottom  of  the  pit  a,  as  shown  by  darts  in  the 
figure ;  the  feathered  ones,  representing  that  part  of  the  pit  in  which  the  course  of  the 
current  of  air  is  free  from  explosive  mixture,  or  does  not  contain  above  one  thirtieth 
of  carbureted  hydrogen,  as  indicated  by  its  eflTect  upon  the  flamaof  a  candle.  The 
naked  darts  denote  the  portions  of  the  mine  where  the  air,  being  charged  to  the  firing 
point,  is  led  off  towards  d,  the  dumb  furnace,  which  communicates  with  the  hot  upcast 
shaft,  out  of  reach  of  the  flame,  and  thence  derives  its  power  of  draught.  By  suitable  alter- 
ations in  the  stoppings^  (see  the  various  transverse  lines,  and  the  crosses),  any  portion  of 
the  workings  may,  by  the  agency  of  the  furnace,  be  laid  out  of,  or  brought  within,  the 
course  of  the  vitiated  current,  at  the  pleasure  of  the  skilful  mine  viewer;  so  that,  if  he 
foind  it  necessary,  he  could  confine,  by  proper  arrangements  >f  his  furnace,  all  the 
vitiated  current  to  a  mere  gas-pipe  or  drift,  and  direct  it  wholly  hrough  the  dumb  fur- 
nace. During  a  practice  of  twenty  years.  Mr.  Buddie  has  not  met  with  any  accident  IB 
consequence  of  a  defect  in  the  stoppings  preventing  the  complete  division  of  the  air. 
The  engineer  has  it  thus  within  his  power  to  detach  or  insulate  those  portions  of  the 
mine  in  which  there  is  a  great  exudation  of  gas,  from  the  rest ;  and,  indeed,  he  is  con- 
tinually making  changes,  borrowing  and  lending  currents,  so  to  speak  ;  sometimes  laying 
one  division  or  panel  upon  the  one  air-course,  and  sometimes  upon  the  other,  just  to 
suit  the  immediate  emergency.  As  soon  as  any  district  has  ceased  to  be  dangerous,  by 
the  exhaustion  of  the  gas-blowers,  it  is  transferred  from  the  foul  to  the  pure  air  course,  where 
gunpowder  may  be  safely  used,  as  also  candles,  instead  of  Davy's  lamps,  which  give  less 
light. 

The  quantity  of  air  put  down  into  the  Wallsend  ».olliery,  at  the  timeof  the  last  dreadful 
iccident,  l8th  June,  1835,  was  not  less  than  5000  cubic  feet  per  minute,  whence  it  has  been 
justly  inferred  that  the  explosion  was  caused  by  the  rashness  of  a  wasteman  carrying  a 
light  through  a  door  into  a  foul  drift. 

Till  the  cutting  out  of  the  pillars  commences  (see  the  risrht  end  of  the  diagram),  the 
▼enlilation  of  the  several  passages,  boards,  &c.,  may  be  kept  perfect,  supposing  the 
working  extended  no  furlher  than  o,  or  b;  because,  as  long  as  there  are  pillars  standing^ 


every  passage  may  be  converted  into  an  air-conduit,  for  leading  a  current  of  air  in  any 
direction,  either  to  c,  the  burning,  or  d,  the  dumb  furnace.  But  the  first  pillar  that  is 
removed  deranges  the  ventilation  at  that  spot,  and  takes  away  the  means  of  carrying  the 
air  into  the  further  recess  towards  c.  In  taking:  out  the  pillars,  the  miners  always  work  to 
windward,  that  is  to  say,  against  the  stream  of  air;  so  that  whatever  gas  may  be  evolved 
shall  be  immediately  carried  ofl'  from  the  people  at  work.    When  a  range  of  pillars  has 


msSBm 


890 


VENTILATION. 


been  removed,  as  at  4  «,/,  no  power  remains  of  dislodging  the  gas  from  the  section 
Of  the  mine  beyond  a,  b;  and  as  the  pillars  are  successively  cut  away  to  the  left  hand 
of  the  line  a,  b,  the  size  of  the  poaf,  or  void,  is  increased.  This  vacuity  is  a  true 
gas-holder,  or  reservoir  continually  discharging  itself  at  the  points  a,  fC  L  into  the 
circulating  current,  to  be  carried  off  by  the  gas-pipe  drift  at  the  dumb  furnace,  but 
not  to  be  suffered  ever  to  come  in  contact  with  flame  of  any  description.  The  next 
range  of  working  is  the  line  of  pillars  to  the  left  of  a.  6  ;  the  coal  having  been  entirely 
cleared  out  of  the  space  to  the  right,  where  the  place  of  the  pillars  is  marked  by  dotted 
lines.  The  roof  in  the  waste  soon  falls  down,  and  gets  fractured  up  to  the  next  seam 
of  coal  called  the  yard-coal  seam,  which,  abounding  in  gas,  sends  it  down  in  laree 
^^e^STOVR  immense  gasometer,  or  goaf  below,  continually  replenished, 

.  '^f^^  ?f«  two  general  plans  in  use  for  at  once  diffusing  heat  and  renewing  the  air 
m  extensive  bii'Idings,  which  plans  differ  essentially  in  their  principles,  modes  of  action, 
and  effects.  The  oldest,  and  what  may  be  called,  the  vulgar  method,  consists  in  planting 
stoves  in  the  pas-ages  or  rooms  to  give  warmth  in  cold  weather,  and  in  construetinS 
large  and  lofty  chimney-stalks,  to  draw  air  in  hot  weather  out  of  the  house  by  suctiob. 
«o  to  speak,  whereby  fresh  air  flows  in  to  maintain,  though  imperfectly,  an  equilibrium 
of  pressure.  In  apartments,  thus  warmed  and  ventilated,  the  atmosphere  is  necessarily 
rarer  than  it  is  out  of  doors,  while,  in  cold  weather,  the  external  air  rushes  in  at  every 
opening  and  crevice  of  door,  window,  or  chimney— the  fruitful  source  of  indisposition 
to  the  inmates.  *^ 

The  evils  resulting  from  the  etove-heating  and  air-rarefying  system  were,  a  few  years 

*^v,'-TT^'^^^       ^^™^'  '"  *  ^^^^^  ^^^^  before  the  Royal  Society,*  and  afterward 
published  in  several  scientific  and  technological  journals.     It  is  there  said  that  the  ob 
servations  of  Saussure,  and  other  scientific  travellers  in  mountainous  regions,  demon- 
strate  how  difficult  and  painful  it  is  to  make  muscular  or  mental  exertions  in  rarefied  air. 
Even  the  slight  rarefaction  of  the  atmosphere,  corresponding  to  a  low  state  of  the  bar- 
ometer, at  the  level  of  the  sea,  is  sufficient  to  occasion  languor,  lassitude,  and  uneasi- 
ness, m  persons  of  delicate  nerves ;  while  the  opposite  condition  of  increased  pressure 
as  indicated  by  a  high  state  of  the  barometer,  has  a  bracing  effect  upon  both  body  and 
mmd.     Thus,  we  see  how  ventilation,  by  the  powerful  draught  of  a  high  chimney-stalk 
as  It  operates  by  pumping  out,  exhausting  and  attenuating  the  air,  may  prove  detriment 
talto  vivacity  and  health ;  and  how  ventilation,  by  forcing  in  air  with  a  fan  or  a  pump, 
IS  greatly  to  be  preferred,  not  only  for  the  reason  above  assigned,  but  because  it  pre' 
vents  all  regurgitation  of  foul  air  down  the  chimneys,  an  accident  sure  to  happen  in  the 
former  method.     Genial  air  thrown  in  by  a  fan,  in  the  basement  story  of  a  building 
also  prevents  the  stagnation  of  vapors  from  damp  and  miasmata,  which  lurk  about  the 
loundation  of  buildings  and  in  sewers,  and  which  are  sucked  in  by  the  rarefyin*'  plan. 
Many  a  lordly  mansion  is  rendered  hardly  tenantable  from  such  a  cause,  durin«' certain 
vicissitudes  of  wind  and  weather. 

The  condensing  plan,  as  executed  by  the  engineers,  Messrs.  Easton  and  Amos,  at  the 
Ketorm  Club  House,  consists  of  a  large  fan,  revolving  rapidly  in  a  cylindrical  case,  and 
is  capable  of  throwing  11,000  cubic  feet  of  air  per  minute,  into  a  spacious  subterranean 
tunnel,  under  the  basement  story.  The  fan  is  driven  by  an  elegant  steam-engine,  worked 
on  the  expansion  principle,  of  5  horses'  power.  It  is  placed  in  a  vault,  under  the  flag- 
pavement,  in  front  of  the  building  ;  and  as  it  moves  very  smoothly,  and  burns  merely 
cinders  Irom  the  house  fires,  along  with  some  anthracite,  it  occasions  no  nuisance  of 
any  kind.  The  steam  of  condensation  of  the  engine  supplies  3  cast-iron  chests  with 
the  requisite  heat  for  warming  the  whole  of  the  building.  Each  of  these  c^iests  is  a 
cube  01  3  feet  externally,  and  is  distributed  internally  into  7  parallel  cast-imn  cases, 

I486  1487 


VENTILATION. 


891 


r 


^ 


i 


1485 


—^ 


•1 ir 

—  — 

—m- 



ii 

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IJ 

■1                                i- 



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^^ISr-^"^^^^^  ^^v\s£?.-  n.-f„%To„t-u.Tru5rJi5ri 


each  about  8  inches  wide,  which  are  separated  by  parallel  alternate  spaces,  of  the  same 
width,  for  the  passage  of  the  air  transversely,  as  it  is  impelled  by  the  fan. 

Mg.  1485  is  a  transverse  vertical  section  of  the  steam  chest,  for  heating  the  air;  ^g. 
1486  is  a  plan  of  the  same;  and  Jig.  1487  is  a  perspective  view,  showing  the  outside 
casing,  also  the  pipe  a,  for  admitting  the  steam,  and  the  stop-cock  6,  for  allowing  the 
condensed  water  to  escape. 

This  arrangement  is  most  judicious,  economizing  fuel  to  the  utmost  degree;  becatisfl 
the  steam  of  condensation  which,  in  a  Watt's  engine,  would  be  absorbed  and  carried  off 
by  the  air-pump,  is  here  turned  to  good  account,  in  warming  the  air  of  ventilation  du- 
ring the  winter  months.  Two  hundred  weight  of  fuel  suffice  for  working  this  steam- 
engine  during  twelve  hours.  It  pumps  water  for  household  purposes,  raises  the  coals 
to  the  several  apartments  on  the  upper  floors,  and  drives  the  fan  ventilator.  The  air, 
in  flowing  rapidly  through  the  series  of  cells,  placed  alternately  between  the  steam- 
cases,  can  not  be  scorched,  as  it  is  generally  with  air  stoves ;  but  it  is  heated  only  to  the 
genial  temperature  of  from  75°  to  85**  Fahr.,  and  it  thence  enters  a  common  chamber  of 
brickwork  in  the  basement  story,  from  which  it  is  let  off  into  a  series  of  distinct  flues, 
governed  by  dialled  valves  or  registers,  whereby  it  is  conducted  in  regulated  quantities 
to  the  several  apartments  of  the  building.  I  am  of  opinion  that  it  would  not  be  easy  to 
devise  a  better  plan  for  the  purpose  of  warming  and  ventilating  a  large  house  ;  and  I 
tm  only  sorry  to  observe,  that  the  plan  projected  by  the  engineers  has  been  injudiciously 
counteracted  in  two  particulars. 

The  first  of  these  is,  that  the  external  air,  which  supplies  the  fan,  is  made  to  traverse 
a  great  heap  of  coke  before  it  can  enter  that  apparatus,  whereby  it  suffers  such  friction 
as  materially  to  obstruct  the  ventilation  of  the  house.  The  following  experiments,  which 
I  made  recently  upon  this  point,  will  place  the  evil  in  a  proper  light :  Having  fitted 
up  Dr.  Wollaston's  differential  barometer,  as  an  anemometer,  with  f  il,  of  specific  gravity 
0*900  in  one  leg  of  its  syphon,  and  water  of  1*000  in  the  other,  covered  with  the  said  ofl 
.n  the  two  cisterns  at  top,  I  found  that  the  stream  of  air  produced  by  the  fan,  in  a  ce» 
tain  pait  of  the  flue,  had  a  velocity  only  as  the  number  8,  while  the  air  was  drawn 
through  the  coke,  but  that  it  had  a  velocity  in  the  same  place  as  the  number  11,  when- 
ever the  air  was  freely  admitted  to  the  fan  by  opening  a  side  door.  Thus,  three 
elevenths,  both  of  the  ventilating  and  warming  effect  of  the  fan,  are  lost.  I  can  not 
divine  any  good  reason  for  making  the  members  of  the  Reform  Club  breathe  an  atmo- 
sphere, certainly  not  improved,  but  most  probably  vitiated,  by  being  passed  in  a  moist 
state  through  a  porous  sulphurous  carbon,  whereby  it  will  tend  to  generate  the  two 
deleterious  gases,  carbonic  oxide  and  sulphuretted  hydrogen,  in  a  greater  or  less  de- 
gree. It  is  vain  to  allege  that  these  gases  may  not  be  discoverable  by  chemical  analy- 
sis— can  the  gaseous  matters,  which  generate  cholera,  yellow  fever,  or  ague,  be  detected 
by  chemical  reagents  ?  No,  truly  ;  yet  every  one  admits  the  reality  of  their  specific 
virus.  I  shoiild  propose  that  the  air  be  transmitted  through  a  large  sheet  of  wire-cloth 
before  it  reaches  the  fan,  whereby  it  would  be  freed  from  the  grosser  particles  of 
soot  that  pollute  the  atmosphere  of  London.    The  wire-cloth  should  be  brushed  every 


morning 


The  second  particular,  which  counteracts  in  some  measure  the  good  effects  of  the  fan 
in  steam  ventilation,  is  the  huge  stove  placed  in  the  top  story  of  the  building.  This 
potent  furnace,  consuming,  when  in  action,  3  cwt.  of  coals  per  day,  tends  to  drawdown 
foul  air,  for  its  own  supply,  from  the  chimneys  of  the  adjoining  rooms,  and  thus  to 
impede  the  upward  current  created  by  the  fan.  I  have  measured,  by  Dr.  Wollaston's 
differential  barometer,  the  ventilating  influence  of  the  said  furnace  stove,  and  find  it  to 
be  perfectly  insignificant— nay,  most  absurdly  so— when  compared  with  the  fan,  as  to 
the  quantity  of  fuel  which  each  requires  per  day.  The  rarefaction  of  air  in  the  stove 
chamber,  in  reference  to  the  external  air,  was  indicated  by  a  quarter  of  an  inch  differ- 
ence of  level  in  the  legs  of  the  oil  and  water  syphon,  and  this  when  the  door  of  the 
stove-room  was  shut,  as  it  usually  is ;  the  tube  of  the  differential  barometer  being 
inserted  in  a  hole  in  the  door.  The  fan  indicates  a  ventilating  force  equal  to  2  inches 
of  the  water  syphon,  which  is  20  inches  of  the  above  oil  and  water  syphon,  and  there- 
fore 80  times  greater  than  that  of  the  stove  furnace  ;  so  that,  taking  into  view  the 
smaller  quantity  of  fuel  which  the  fan  requires,  the  advantage  in  ventilation,  in  favor 
of  the  fan,  m  the  enormous  ratio  of  120  to  1,  at  the  lowest  estimate.  The  said  stove, 
in  the  attic,  seems  to  me  to  be  not  only  futile,  but  dangerous.  It  is  a  huge  rectangular 
cast-iron  chest,  having  a  large  hopper  in  front,  kept  full  of  coals,  and  il  is  contracted 
above  into  a  round  pipe,  which  discharges  the  burnt  air  and  smoke  into  a  series  of  hori- 
zontal pipes  of  cast-iron,  about  4  inches  diameter,  which  traverse  the  room  under  the 
ceiling,  and  terminate  in  a  brick  chimney.  In  consequence  of  this  obstruction,  the 
draught  through  the  furnace  is  so  feeble,  that  no  rush  of  air  can  be  perceived  in  its  ash- 
pit, even  when  this  is  contracted  to  an  area  of  6  inches  square :  nav,  when  the  ash-pit 
was  momentarily  luted  with  bricks  and  clay,  and  the  tube  of  the  differential  barometer 


892 


VENTILATION. 


was  introduced  a  little  way  under  the  grate,  the  level  of  the  oil  and  water  svDhon  in  that 
instrument  was  d.splaeed  by  no  more  than  one-tenth  of  an  ineh.  which  is  itone  W 
dredth  of  an  inch  of  water-a  most  impotent  effect  under  a  daily  consumption  of  3  c^. 
of  coals.  In  fact  this  stove  may  be  fitly  styled  an  incendiary  coaUdev^rn  as  it  has 
already  set  fire  to  the  house;  and  though  now  laid  upon  a  new  floor  of  CTifters  ^d 
stone  flags,  it  stUl  oflers  so  much  danger  from  its  outlet  iron  pipes,  shouirthey  become 
pited  from  the  combustion  of  charcoal  deposited  in  them,  that  I  think  no  premium  7 
insurance  adequate  to  cover  the  imminent  risk  of  fire.  The  stove  being,  theSe  a 
superfluous  and  dangerous  nuisance,  should  be  turned  out  of  doors  as  spVedily  as  pos! 
tt\y.^VT\T'T^  ^^^'  ?^"«^^"«^  i«  the  basement  story,  can  not  bemuch  kss 
Wurtenances  ^^^"°^-^"-^^°^'  ^^^^  ^^  '^'^  '^y  ^ff^^tual  warming  and  ventllaUng 

.J  If ^^^ J^\?  ^"^  "^^f'^^'  ^^""^  ^^^  ^y«^^"^  o^  ^^^ting  and  ventilating  apparatus,  con- 
■^ucted  by  Messrs.  Easton  and  Amos,  in  the  Reform  Club  House,  offers  one  s^kT"; 
and  peculiar  advantage      It  may  be  modified  at  little  expense,  so  as  to  become  the  read? 

Sure  o?  10  20"'^^'  """^  '""LT'"'''  ^°^.-^'>"^'  refreshingcurrentsof  air,at  atem! 
?hTl  ?  ?:  u'  ?  '  *'''.^7''  ^^  ^^"^^""^  ^°^^^  that  of  atmosphere.  An  apparatus  of 
?  •  ^^ture  attached  to  the  houses  of  parliament  and  courts  of  law,  would  prove  an  in- 
estimable  blessing  to  our  legislators,  lawyers,  judges,  and  juries.  Of  sudi  coofiJ  a 
very  gentle  stream  would  suffice  to  make  the  molt  crowded  apartments  eom?ortrble 
J^&:l'd"roor"'  '''  ''''*'  °'  ^'"^  '^^^^^  "^^^  ^^^^^  «^-"^  throughTdooi:; 

-«?ii' J^tK-^"^''r  ^^  ^  •  ""^H^  *'°'^.  ^^"^^  ^^'  ^'^^^  '^^"^  ^«>-  the  well-being  of  the  sentient 
and  breathing  functions  of  man  in  the  public  buildings  of  the  metropolfs,  notwithstand. 

^ZZ^T%iT'\^^'T^^'''^  ""^  ^^«*"^'«'^  «^  "^^^"1  knowledge.  Almost  a^^^^^^^^ 
churches  are  filled  on  Sundays  with  stove-roasted  air;  and  even  the  House  of  Commons 
has  Its  atmosphere  exhausted  by  the  suction  of  a  huge  chimney-stalk,  with  a  furnace 
equal,  I  13  said  to  that  of  a  40-horse  steam-boiler.  To  gentlemen  plunged  in  ir  m 
Sf  the'da?:'"     ''''^''^''^^'^''"^^'  and  terseness  of  expression  can  hardly  be  toe^Jd« 

Nearly  seven  years  have  elapsed  since  I  endeavored  to  point  public  attention  to  thin 
important  subject  in  the  following  terms  :  «  Our  legislatoS^  wh^n  bewa" 
ago,  the  fate  of  their  fellow-creatures,  doomed  to  breathe  the  polluted  air  of  a  facto^ 
were  httle  aware  how  superior  the  system  of  ventilation  adopSU  many  co"onS 
was  to  that  employed  for  their  own  comfort  in  either  house  of  parliament!    The  eTi  ! 
neers  cf  Manchester  do  not,  like  those  of  the  metropolis,  trust  for  a  sufficient  suppIv  of 

I^fftZ:  ?r^  ''T'*'^  ^^?^'°  ^^^'"^^^  physically  created  in  the  atmosphere  by^^^^ 
difference  of  temperature  excited  by  chimney-draughts,  because  they  know  them  LhP 
ineffectual  to  remove  with  requisite  rapidit/,  the  dense  carboniVacTd  gas  gener^t^  bv 
many  hundred  powerful  lungs."*  At  page  382  of  the  work  just  quoted,  S^  ^ 
exact  drawing  and  description  of  the  factory  ventilatin-  fan 

On  the  6th  of  June,  1836,  I  took  occasion  again,  in  a  paper  read  before  the  Roval 
Society,  upon  the  subject  of  the  malaria  which  then  prevailed  in  the  customhouse  to 
investigate  the  principles  of  ventilation  by  the  fan,  and  to  demonstrate,  ^a  numerous 
tram  of  experiments  the  great  preference  due  to  it,  as  to  effect,  economy,  and  rmfort 
over  chimney-draught  ventilation.     Yet  at  this  very  time,  the  litter  Cs^oWecUonabVe 

Abou7?h;"  r^'"''  f  T'''^''^^^'  «Po^  ^  colossal  scale,  for  the  H?use  of  Commons 
About  the  same  period,  however,  the  late  ingenious  Mr.  Oldham,  engineer  of  the^ank 
of  England,  mounted  a  mechanical  ventilator  and  steam-chest  heater  f^r  supply int  a 
copious  current  of  warm  air  to  the  rooms  of  the  engraving  and  prin  L-  depar^meits'of 
that  establishment.     Instead  of  a  fan,  Mr.  Oldham^-mployed  a  farge  pump^o  forc^^^^^^^ 

Znf'rt  1^%'t'?^'I  '!"^  ^^  ^''  steam-chest.     He  had  introdu^ced  a  siiiuar  system 
into  the  bank  of  Ireland  about  ten  years  before,  which  is  now  in  full  action 

About  two  years  ag^  Messrs.  Easton  and  Amos  were  employed  to  ventilate  the  letter 
earners'  and  inland  office  departments  of  the  general  post-office,  of  whththe^ 
spnere  was  rendered  not  only  uncomfortable  but  insalubrious  by  the  numerous  iT 
lights  required  there  in  the  evenings.  This  task  has  been  execuKo  tLTnTe  s^^^^^ 
faction  of  their  employers,  by  means  of  fans  driven  by  steam-engne  power  The  saS 
ba^k^r/r^'f '^^r°'''  '^"  '^"^^  '''^''  ^  '''  «^  machinery  simfla?  to  tCer'ect  Jd  at  the 
^ndn5t  ?f^^''^>'  rj"""-"^  ?^  ventilating  the  bank  of  Vienna.  They  are  Justly 
enmled  to  the  credit  of  having  been  the  first  to  execute,  in  all  its  bearin4  the  sjstem 

whirrs^^ru^r^^^^^ 

As  fans  of  sufficient  size,  driven  by  steam  powe?  with  sufficient  velocity  to  warm  in 
winter,  and  ventilate  at  all  times,  the  most  extensive  buildings,  may  be  Sed  upon  the 

*  Philosophy  of  ManufHctures,  p.  380.  published  by  diaries  Knight-London,  1835. 


m 


VENTILATION. 


89o 


principles  above  described,  without  causing  any  nuisance  from  smoke,  it  is  be  hoped 
that  the  Chapel  of  Henry  VII.  will  not  be  desecrated  by  having  a  factory  Vesuvius 
reared  in  its  classical  precincts,  and  that  the  noble  pile  of  architecture  of  the  new 
houses  of  parliament  will  not  be  disfigured  with  such  a  foul  phenomenon. 

^  The  cheering  and  bracing  action  of  condensed  air,  and  the  opposite  effects  of  rarefied 
air  upon  human  beings,  formed  the  subject  of  several  fine  physiological  experiments, 
made  a  few  years  ago  by  M.  Junot,  and  described  by  him  in  the  ninth  volume  of  the 
Archives  Generales  de  Medecine  :  "  When  a  person  is  placed,'*  says  he,  "  in  condensed 
air,  he  breathes  with  a  new  facility ;  he  feels  as  if  the  capacity  of  his  lungs  was  en- 
larged ;  his  respirations  become  deeper  and  less  frequent ;  he  experiences,  in  the  course 
of  a  short  time,  an  agreeable  glow  in  his  chest,  as  if  the  pulmonary  cells  were  becoming 
dilated  with  an  elastic  spirit,  while  the  whole  frame  receives,  at  each  inspiration,  fresh 
vital  impulsion.  The  functions  of  the  brain  get  excited,  the  imagination  becomes  vivid, 
and  the  ideas  flow  with  a  delightful  facility ;  digestion  is  rendered  more  active,  as  after 
gentle  exercise  in  the  air,  because  the  secretory  organs  participate  immediately  in  the 
increased  energy  of  the  arterial  system,  and  there  is  therefore  no  thirst." 

In  rarefied  air  the  effects  on  the  living  functions  are  just  the  reverse.  The  breathing 
is  difficult,  feeble,  frequent,  and  terminates  in  an  asthmatic  paroxysm ;  the  pulse  is  quick 
and  most  compressible;  hoemorrhages  often  occur,  with  a  tendency  to  fainting;  the 
secretions  are  scanty  or  totally  suppressed,  and  at  length  apathy  supervenes. 

These  striking  results  obtained  on  one  individual  at  a  time,  with  a  small  experimental 
apparatus,  have  been  recently  reproduced,  on  a  working  scale,  with  many  persons  at 
once  enclosed  in  a  mining-shaft,  encased  with  strong  tubbing,  formed  of  a  series  of 
large  sheet-iron  cylinders,  riveted  together,  and  sunk  to  a  great  depth  through  the  bed 
of  the  river  Loire,  near  Languin.  The  seams  of  coal,  in  this  district  of  France,  lie 
under  a  stratum  of  quicksand,  from  18  to  20  metres  thick  (20  to  22  yards),  and  they 
had  been  found  to  be  inaccessible  by  all  the  ordinary  modes  of  mining  previously  prac- 
tised. The  obstacle  had  been  regarded  to  be  so  perfectly  insurmountable,  that  every 
portion  of  the  great  coa^-basin,  that  extends  under  these  alluvial  deposites,  though  we| 
known  for  centuries,  had  remained  untouched.  To  endeavor,  by  the  usual  workings, 
to  penetrate  through  these  semi-fluid  quicksands,  which  communicate  with  the  waters 
of  the  Loire,  was,  in  fact,  nothing  less  than  to  try  to  sink  a  shaft  in  that  river,  or  to 
drain  the  river  itself.  But  this  difficulty  has  been  successfully  grappled  with,  through 
the  resources  of  science,  boldly  applied  by  M.  Triger,  an  able  civil  engineer. 

By  means  of  the  above  frame  of  iron  tubbing,  furnished  with  an  air-tight  ante- 
chamber at  its  top,  he  has  contrived  to  keep  his  workmen  immersed  in  air,  sufficiently 
condensed  by  forcing-pumps,  to  repel  the  water  from  the  bottom  of  the  iron  cylinders, 
and  thereby  to  enable  them  to  excavate  the  gravel  and  stones  to  a  great  depth.  The 
compartment  at  top  has  a  man-hole  door  in  its  cover,  and  another  in  its  floor.  The 
men,  after  being  introduced  into  it,  shut  the  door  over  their  heads,  and  then  turn  the 
stop-cock  upon  a  pipe,  in  connexion  with  the  condensed  air  in  the  under  shaft.  An 
equilibrium  of  pressure  is  soon  established  in  the  ante-chamber,  by  the  influx  of  the 
dense  air  from  below,  whereby  the  man-hole  door  in  the  floor  may  be  readily  opened, 
to  allow  the  men  to  descend.  Here  they  work  in  air,  maintained  at  a  pressure  of  three 
atmospheres,  by  the  incessant  action  of  leathern-valved  pumps,  driven  by  a  steam-eneine. 
While  the  densj  air  thus  drives  the  waters  of  the  quicksand,  communicating  with  the 
Loire,  out  of  the  shaft,  it  infuses  at  the  same  time  such  energy  into  the  miners,  that 
they  can  easily  excavate  double  the  work  without  fatigue  which  they  could  do  in  the 
open  air.  Upon  many  of  them  the  first  sensations  are  painful,  especially  upon  the  ears 
and  eyes,  but  ere  long  they  get  quite  reconciled  to  the  bracing  element.  Old  asthmatic 
men  become  here  effective  operatives ;  deaf  persons  recover  their  hearing,  while  others 
are  sensible  to  the  slightest  whisper.  The  latter  phenomenon  proceeds  from  the  stronger 
pulses  of  the  dense  air  upon  the  membrane  of  the  drum  of  the  ear. 

Much  annoyance  was  at  first  experienced  from  the  rapid  combustion  of  the  candles, 
but  this  was  obviated  by  the  substitution  of  flax  for  cotton  thread  in  the  wicks.  The 
temperature  of  the  air  is  raised  a  few  degrees  by  the  condensation. 

Men  who  descend  to  considerable  depths  in  diving-bells,  experience  an  augmentation 
of  muscular  energy,  similar  to  that  above  described.  They  thereby  acquire  the  power 
of  bending  over  their  knees  strong  bars  of  iron,  which  they  would  find  quite  inflexible 
by  their  utmost  efforts  when  drawn  up  to  the  surface. 

These  curious  facts  clearly  illustrate  and  strongly  enforce  the  propriety  of  ventilating 
apartments  by  means  of  condensed  air,  and  not  by  air  rarefied  with  large  chimney- 
draughts,  as  ha^  been  hitherto  most  injudiciously,  wastefully,  and  filthily  done,  in  too 
many  cases. 

As  the  subject  of  Tentilating  and  warnrting  the  public  buildings  in  Liverpool,  and 
particularly  the  new  Custom-house,  has  been  imder  discussion,  we  extract  from  the 
Architectural  Journal  the  following  paper  hv  Mr.  C.  W.  Williams. 

"Doctor  Ure,  in  his  inquiry  into  the  modes  of  warming  and  ventilating,  oUerves, 


m 


894 


VENUS. 


i 

4 


that  the  great  principle  of  ventilation  is,  never  to  present  the  same  portion  of  M*r  twice 
over  to  the  human  lungs^  but  to  supply  them  at  each  fresh  inspiration  with  pure  aerial 
particles  in  a  genial  thermometric  and  hygrometric  condition/ 

"  Where  heating  is  alone  attended  to,  as  in  the  case  of  heat  conveyed  by  steam  in 
metal  pipes,  it  becomes  necessary  to  provide  currents  of  cold  air,  to  supply  the  required 
continued  change  in  the  apartments  for  the  purposes  of  ventilation.     It  is  manifest  then, 
that  the  best  principle  must  be,  first,  to  heat  the  required  volume  of  fresh  air  and  then 
to  introduce  it  to  the  apartments  to  be  heated  and  ventilated,  instead  of  effecting  this 
double  object  by  two  distinct  processes.     The  modus  operandi  is  as  follows :— A  body  of 
pure  air,  of  any  required  volume,  and  passing  at  any  required  velocity,  is  forced,  by  the 
aid  of  an  air-condensing  pump,  into  a  chamber  or  chest,  where  it  is  heated  in  an  ingeni- 
ously contrived,  but  extremely  simple  apparatus,  by  means  of  cross  currents  of  steam. 
Ibe  peculiarity  of  this  contrivance  is,  that  an  ascending  body  of  air,  on  entering  this 
chest,  divides  itself  spontaneously  into  any  required  number  of  thin  horizontal  films, 
by  which  a  very  extending  surface  is  exposed  to  corresponding  steam-heated  metal 
surfacea     Instead,  therefore,  of  passing  the  steam  through  a  series  of  pipes,  along 
Which,  but  in  an  opposite  direction,  the  condensed  water  has  to  return,  it  is  conveyed 
at  once  from  the  boiler  into  the  chest,  or  condenser,  which,  in  fact,  it  is,)  where,  on 
having  parted  with  its  heat  to  the  air  as  above  described,  it  is  condensed,  and  returned 
directly  to  the  boiler.     The  chest  or  condenser,  in  the  apparatus  at  the  Bank  of  England, 
18  but  3  feet  square,  yet  the  body  of  air  to  be  heated,  while  passing  over  but  3  lineal 
feet,  spreads  itself  oner  no  less  than  164  superficial  feet,  and,  coming  in  contact  with  a 
corresponding  superficies,  heated  by  the  steam,  it  necessarily  receives  a  very  large  sup- 
ply of  heat  in  a  short  space  of  time.  J      &       r- 
" The  apparatus  in  the  Bank  of  England,  independently  of  heating  and  ventilating 
several  large  apartments,  is  put  to  the  severest  test,  namely,  that  of  evaporatinir  the 
moisture  from  a  series  of  400  large  mill-boards,  with  a  surface  of  1600  feet,  and  which 
moisture  they  have  absorbed  from  the  fresh  printed  bank  notes  which  are  dailv  dried 
by  this  process.  •' 

"With  respect  to  the  quantity  of  heat  which  this  small  apparatus  is  capable  of  im- 
parting to  the  air,  this  is  accurately  tested  by  the  quantity  of  water  which  is  con- 
aensed,  and  which  amounts  hourly  to  twelve  gallons. 

"Of  the  efficacy  of  an  artificial  current  produced  by  means  of  a  fan  or  cylinder,  Dr. 
Ure  observes,  that  'it  has  been  ascertained  that  a  power  equivalent  to  one  horse,  in  a 
steam  engine,  will  drive  at  the  rate  of  80  feet  per  second  a  fan,  the  effective  surfaces  of 
whose  vanes,  and  whose  inhaling  conduits,  have  each  an  area  of  18  inches  square,  equal 
to  that  of  a  large  steam  boiler  chimney.  The  velocity  of  air  in  the  chimney,  produced 
by  a  consumption  of  fuel  equivalent  to  the  power  of  twenty  horses  was  no  more  than 
86  feet  per  second;  while  that  of  the  fan,  as  impelled  by  the  power  of  one  horse,  was 
66  feet  per  second.  Hence  it  appears  that  the  economy  of  ventilation  by  the  fan  is  to 
that  by  the  chimney  draught,  as  66  X  20  is  to  35,  or  88  to  1.  It  is  obvious,  therefore, 
that,  with  one  bushel  of  coals  consumed  in  working  a  steam-impelled  eccentric  fan,  we 
can  obtain  as  great  a  degree  of  ventilation,  or  we  can  displace  as  great  a  volume  of  air, 
as  we  could  with  38  bushels  of  coals  consumed  in  creating  a  chimney  draught  Econo- 
™?'  u  T^^"^^^  *"*^  compactness  of  construction,  are  not^  however,  the  sole  advantages 
which  the  mechanical  system  of  ventilation  possesses  over  the  physical.  It  is  infallible, 
even  under  such  vicissitudes  of  wind  and  weather  as  would  essentially  obstruct  any 
chimney  draught  ventilation,  because  it  discharges  the  air  with  a  momentum  quite 
eddy  proof;  and  it  may  be  increased,  diminished,  or  stopped  altogether,  in  the  twink- 
ling  ot  an  eye,  by  the  mere  shifting  of  a  band  from  one  pulley  to  another.  No  state  of 
atmospher*}  without,  no  humidity  of  air  within,  can  resist  its  power.  It  will  impel  the 
air  of  a  crowded  room,  loaded  with  the  vesicular  vapors  of  perspiration,  with  equal 
certainty  as  the  driest  and  most  expansive." 

After  so  clear  and  practical  an  exposition  of  the  advantages  of  a  current^  mechani- 
caLy  created,  nothing  further  need  be  said  of  natural  currents  arising  from  mere  in- 
crease  of  temperature,  excepting  that,  by  the  adoption  of  the  pump  instead  of  the  fan,  a 
very  considerable  power  is  saved,  and  the  operation  performed  much  more  effectively. 

Another  peculiarity  of  Mr.  Oldham's  apparatus  here  merits  attention.  The  large 
volume  of  air  heated  and  passed  off  to  the  required  apartments  is,  previously  to  iU 
being  received  into  the  heating  chest,  filtered  and  purified,  by  being  deprived  of  all 
that  noxious  floating  matter  with  which  the  atmosphere,  particularly  that  of  London, 
IS  at  all  times  charged,  and  which,  if  heated  and  sent  into  the  apartments  with  the  air, 
would  but  increase  that  noxious  character,  and  render  it  still  more  injurious  to  the  res- 
piration of  human  beings.  Not  only,  indeed,  are  these  offensive  impurities  which  are 
floating  in  the  atmosphere  effectually  separated,  but  a  power  is  given  of  charging  it 
with  aromatic  or  antiseptic  matter,  thus  rendering  it  not  only  the  medium  of  warmth 
and  ventilation,  but  of  purifying  and  healthful  influences. 

VENUS,  is  the  mythological  name  of  copper. 


VERDIGRIS. 


895 


VERATRINE,  is  a  vegetable  alkali,  of  a  poisonous  nature,  extracted  from  the  seeds 
of  the  Veratrum  sabadilla,  the  roots  of  the  Veratrum  album,  or  while  hellebore,  and  of 
Colchicum  autumnale,  or  meadow  saffron,  in  which  plants  it  exists  combined  chiefly  with 
gallic  acid.  It  is  obtained  in  the  form  of  a  white  powder.  It  has  an  acrid,  burning 
taste,  but  without  any  bitterness;  it  has  no  smell;  but  when  snuffed  into  the  nostrils, 
it  excites  violent  and  dangerous  sneezing.  It  melts  at  a  heat  of  122'^  F.,  and  concretes, 
on  cooling,  into  a  transparent  yellowish  mass.  It  restores  the  blue  color  of  reddened 
litmus  paper.  It  is  hardly  soluble  in  water  or  ether,  but  abundantly  in  alcohol.  It 
consists  of— carbon  66-76,  hydrogen  8*54,  nitrogen  5*04,  and  oxygen  19-60.  Its  saline 
compounds  have  an  acrid  and  burning  taste.  Veratrine  resembles  strychnine  and  brucine, 
in  its  effects  upon  living  bodies,  producing  tetanus  and  death  in  a  moderate  dose;  not- 
withstanding whicli,  it  has  been  prescribed  by  some  of  our  poison  doctors,  especially 
mixed  with  hog's  lard,  in  the  form  of  frictions  on  the  forehead,  for  nervous  maladies; 
but  seldom,  I  believe,  with  any  good  effects. 

VERDIGRIS.  {Vert-de-gris,  Ft.;  Grunspariy  Germ.)  The  copper  used  in  this 
manufacture,  is  formed  into  round  sheets,  from  20  to  25  inches  diameter  by  one  Iwenty- 
foartli  of  an  inch  in  thickness.  Each  sheet  is  then  divided  into  oblontf  squares,  from  4 
to  6  inches  in  length,  by  3  broad ;  and  weighing  about  4  ounces.  They  are  separately 
beaten  upon  an  anvil,  to  smooth  their  surfaces,  to  consolidate  the  metal,  and  to  free  it 
from  scales.  The  refuse  of  the  grapes,  after  the  extraction  of  their  juice,  formerly 
thrown  on  to  the  dunghill,  is  now  preserved  for  the  purpose  of  making  verdigris.  It  is 
put  loosely  into  earthen  vessels,  which  are  usually  16  inches  high,  14  in  diameter  at 
the  widest  part,  and  about  12  at  the  mouth.  The  vessels  are  then  covered  with  lids, 
which  are  surrounded  by  straw  mats.  In  this  situation  the  materials  soon  become 
heated,  and  exhale  an  acid  odor;  the  fermentation  beginning  at  the  bottom  of  the  cask, 
and  gradually  rising  till  it  actuate  the  whole  mass.  At  the  end  of  two  or  three  days, 
the  manufacturer  removes  the  fermenting  materials  into  other  vessels,  in  order  to  check 
the  process,  lest  putrefaction  should  ensue.  The  copper  plates,  if  new,  are  now  pre- 
pared, by  rubbing  them  over  with  a  linen  cloth  dipped  in  a  solution  of  verdigris;  and  they 
are  laid  up  alongside  of  one  another  to  dry.  If  the  plates  are  not  subjected  to  this 
kind  of  preparation,  they  will  become  black,  instead  of  green,  by  the  first  operation. 
When  the  plates  are  ready,  and  the  materials  in  a  fermenting  state,  one  of  them  is  put 
into  the  earthen  vessel  for  24  hours,  in  order  to  ascertain  whether  it  be  a  proper  period 
to  proceed  to  the  remaining  part  of  the  process.  If,  at  the  end  of  this  period,  the  plate 
be  covered  with  a  uniform  green  layer,  concealing  the  whole  copper,  everything  is 
right;  but  if,  on  the  contrary,  liquid  drops  hang  on  the  surface  ©f  the  metal,  the  work- 
nen  say  the  plates  are  sweating,  and  conclude  that  the  heat  of  the  fermented  mass  has 
been  inadequate ;  on  which  account  another  day  is  allowed  to  pass  before  makin?  a  simi- 
lar trial.  When  the  materials  are  finally  found  to  be  ready,  the  strata  are  formed  in  the 
following  manner.  The  plates  are  laid  on  a  horizontal  wooden  gratin?,  fixed  in  the 
middle  of  a  vat,  on  whose  bottom  a  pan  full  of  burning  charcoal  is  placed,  which  heats 
them  to  such  a  degree,  that  the  women  who  manasfe  this  work  are  obliged  to  lay  hold 
of  them  frequently  with  a  cloth  when  they  lift  them  out.  Ther  are  in  this  state  put 
into  earthen  vessels,  in  alternate  strata  with  the  fermented  m'aterials,  the  uppermost 
and  undermost  layers  being  composed  of  the  expressed  grapes.  The  vessels  are  covered 
with  their  straw  mats,  and  left  at  rest.  From  30  to  40  pounds  of  copper  are  put  into 
one  vessel. 

At  the  end  of  10,  12,  15,  or  20  days  the  vessels  are  opened,  to  ascertain,  by  the 
materials  having  become  white,  if  the  operation  be  completed. 

Detached  glossy  crystals  will  be  perceived  on  the  surface  of  the  plates ;  in  which 
case  the  grapes  are  thrown  away,  and  the  plates  are  placed  upright  in  a  corner  of  the 
verdisris  cellar,  one  against  the  other,  upon  pieces  of  wood  laid  on  the  ground.  At  the 
end  of  two  or  three  days  they  are  moistened  by  dipping  in  a  vessel  of  water,  after  which 
they  are  replaced  m  their  former  situation,  where  they  remain  seven  or  eight  days,  and 
are  then  subjected  to  momentary  immersion,  as  before.  This  alternate  moistening  and 
exposure  to  air  is  performed  six  or  eight  times,  at  regular  intervals  of  about  a  week.  As 
these  plates  are  sometimes  dipped  into  damaged  wine,  the  workmen  term  these  immer- 
sions, otie  wine,  two  winesy  &c. 

By  this  treatment,  the  plates  swell,  become  green,  and  covered  with  a  stratum  of 
verdigris,  which  is  readily  scraped  off  with  a  knife.  At  each  operation  every  vessel  yields 
from  nve  to  six  pounds  of  verdigris,  in  a  fresh  or  humid  state;  which  is  sold  to  whole- 
sale  dealers,  who  dry  it  for  exportation.  For  this  purpose,  they  knead  the  paste  ia 
wooden  troughs,  and  then  transfer  it  to  leathern  bags,  a  foot  and  a  half  long,  and  ten 
inches  in  diameter.  These  bags  are  exposed  to  the  sun  and  air  till  the  verdigris  has  at- 
tained a  sufficient  degree  of  hardness.  It  loses  about  half  its  weight  in  this  operation; 
and  It  IS  said  to  be  knife-proof,  when  this  instrument,  plunged  through  the  leathern  bag, 
cannot  penetrate  the  loaf  of  verdigris. 


896 


VTERDITER. 


The  manufacture  of  verdigris  at  Montpellier  is  altogether  domestic.  In  most  vnnt 
farm-houses  there  is  a  verdigris  celJar;  and  its  principal  operations  are  conducted  by  the 
females  of  the  family  They  consider  the  forming  the  strata,  and  scraping  off  the  ver- 
digris^ the  most  troublesome  part  Chaptal  says  that  this  mode  of  nTakin^  verdigris 
would  admit  of  some  improvements:  for  example,  the  acetification  requires  a  warmer 
temperature  than  what  usually  rises  in  the  earthen  vessels;  and  the  plates,  when  set 
aside  to  generate  the  coat  of  verdigris,  require  a  different  degree  of  heat  and  moisture 
from  that  re(juisite  for  the  other  operations. 

Verdigris  is  a  mixture  of  the  crystallized  acetate  of  copper  and  the  sub-acetate  in 

varying  proportions.     According  to  Vauqnelin's  researches,  there  are  three  compounds 

of  oxide  of  copper  and  acetic  acid  ;  1,  a  subacetate,  insoluble  in  water,  but  decomposinj? 

in  that  fluid,  at  common  temperatures  changing  into  peroxide  and  acetate;  2,  a  neutral 

acetate  the  solution  of  which  is  not  altered  at  common  temperatures,  but  is  decomposed 

uy  ebullition,  becoming  peroxide  and  superacetate;    and,  3,  superacetate,  which  in 

solution  IS  not  decomposed,  either  at  common  temperatures  or  at  the  boilm.?  point  j  and 

which  caanot  be  obtained  in  crystals,  except  by  slow  spontaneous  evaporation,  in  air  or 

m  vacuo      The  iiri>i  salt,  in  the  dry  slate,  contains  66-ol  of  oxyde;    the  second,  44-44  j 

Mr.   Phillips   has  given  the  following  analyses  of  French  and  English   verdierii: 
Mnals  0/ Philosophy,  No.  21.—  ^     ^ 

French  Veidigris.  English  Venligrifc 
Acetic  acid            -    29-3  29*62 

Peroxyde  of  copper    4o'd  44'2o 

Water  -        -    25-2  25-51 

Impurity       -        -      20  0  62 


100-0  10000 

Distilled  verdigris,  as  it  was  long  erroneously  called,  is  merely  a  binaceiate  or  supei». 
acetate  of  copper,  made  by  dissolving,  in  a  copper  kettle,  one  part  of  verdigris  in  two  of 
distilled  vinegar ;  aiding  the  mutual  action  by  slis;ht  heat  and  agitation  with  a  wooden 
spatula.  When  the  liquor  has  taken  its  utmost  depth  of  color,  it  is  allowed  to  settle, 
and  the  clear  portion  is  decanted  off  into  well-glazed  earthen  vessels.  Fresh  vinegar  is 
poured  on  the  residuum,  and  if  its  color  does  not  become  deep  enough,  more  verdigris  is 
added.  The  clear  and  saturated  solution  is  then  slowly  evaporated,  in  a  vessef  kept 
uniformly  filled,  till  it  acquires  the  consistence  of  sirup,  and  shows  a  pellicle  on  its  sur- 
face ,-  when  it  is  transferred  into  glazed  earthen  pans,  called  oulas  in  the  country.  In 
eachof  these  dishes,  two  or  three  sticks  are  placed,  about  a  foot  Ions,  cleft  till  within 
two  inches  of  their  upper  end,  and  having  the  base  of  the  cleft  kept  asunder  by  a  bit  of 
wood.  This  kind  of  pyramid  is  suspended  by  its  summit  in  the  liquid.  AH  these  vessels 
are  transported  into  crystallizing  rooms,  moderately  heated  with  a  stove,  and  left  in  the 
same  state  for  15  days,  taking  care  to  maintain  a  uniform  temperature.  Thus  are  ob- 
tained very  fine  groups  of  crystals  of  acetate  of  copper,  clustered  round  the  wooden  rods; 
on  which  they  are  dried,  taken  off;  and  sent  into  the  market.  They  are  distinctly  rhom^ 
boidal  in  form,  and  of  a  lively  deep  blue  color.  Each  cluster  of  crystals  weighs  from 
five  to  six  pounds ;  and,  in  general,  their  total  weight  is  equal  to  about  one  third  of  the 
verdigris  employed. 

The  crystallized  binacetate  of  commerce  consists,  by  my  analysis,  of— acetic  acid,  62 ; 
oxyde  of  copper,  39-6 ;  water,  8-4,  in  100.  I  have  prepared  crystals  which  contain  no 
water.  There  is  a  triple  acetate  off  copper  and  lime,  which  resembles  distilled  verdigris  in 
color.  It  was  manufactured  pretty  extensively  in  Scotland  some  years  aso,  and  fetched  a 
high  price,  till  I  published  an  analysis  of  it  in  the  Edinburgh  Philosophical  Journal.  It 
IS  much  inferior,  for  all  uses  in  the  arts,  to  the  proper  binacetate. 

VERDITER,  01  BLUE  VERDITER.  This  is  a  precipitate  of  oxyde  of  copper  with 
lime,  made  by  adding  that  earth,  in  its  purest  state,  to  the  solution  of  nitrate  of  copper, 
obtained  in  quantities  by  the  refiners,  in  parting  gold  and  silver  from  copper  by  nitric 
acid.  The  cupreous  precipitate  must  be  triturated  with  lime,  after  it  is  nearly  dry,  to 
bring  out  the  fine  velvety  blue  color.  The  process  is  delicate,  and  readily  misgives  in 
unskilful  hands. 

The  ceTidres  bleues  en  pate  of  the  French,  though  analogous,  arc  in  some  respects  a  dif- 
ferent preparation.  To  make  it,  dissolve  sulphate  of  copper  in  hot  water,  in  such  pro- 
portions that  the  liquid  may  have  a  density  of  1-3.  Take  240  pound  measures  of  this  so- 
lution, and  divide  it  equally  into  4  open-headed  casks;  add  to  each  of  these  45  pound 
measures  of  a  boiling-hot  solution  of  muriate  of  lime,  of  specific  gravity,  1-317,  whereby 
a  double  decomposition  will  ensue  ;  with  the  formation  of  muriate  of  copper  and  sulphate 
of  lime,  which  precipitates.  It  is  of  consequence  to  work  the  materials  well  together 
at  the  moment  of  mixture,  to  prevent  the  precipitate  agglomerating  in  unequal  masses. 


VERDITER.  897 

Lch  preciSn  soZ  nf  ?h "^K^  '""^nV'  '""^'^^^  ^^  ^''^''     ^houl/  eithe'r  caiaS 

Meanwhile,  a  magna  of  lime  is  to  be  prepared  as  follows-— Ifift  nmin^-  «<•       •  i 

furnish  from  5»0  to  540  pounds  rflrecn  pas'e^  """''''""'  "'^  """"'""'  P"^"'""""  ■"»'«• 
deferLTi^erbfd'rjtilSo""  2^"^^,"'  J!!^,''"'"'"'^  <!-""  P-en,  in  it  n,us,  b, 

Ju-rS  S^F^^f^^^^  Kd -r  rorn:ti-- 

XTe  mixture  is  t^LjT,',  ""^  ?•"•  ^T"  '1".  P^viously  prepared;  and  the 
auiclr^htffdoVe:  tt  m^llSWn^  T^T'  '"""''"'^  "  "  '='"°'-^'-    ^'"' 

ZV^lhh  a  n  lut'e      A^  !h^"  ".  '"r**/  T"'""">'  •'^'"^'^-    The  cork  mus    Tow  te 
Jmer  an^elTfrfri  '  ^'  '^P?'^^'^^^  ^mid  is  run  off;  when  it  is  fiUed  up  aLrwith 

provided  it  has  not  been  lonJandlarlfnnv  7-  h     "a '''*^  '"v"' '™''  "  '*  «»*"»  «ff««'«i. 
and  gives  it  a  bro,vn  or  blackishireefS  ^  """'^  "'"  """'"'^  '' »'"  "^  '"^''«^ 

Calsel  Euraci"iS''t  '°-5-  '^  "^  '^'"«'*' '"«  P"'"^^  «f  fabrication  in  Bretne.. 

dr;;a^/tt«tr^''te^;;Jefn'n;i'itr^s";T;r;'^.n 

6.  225  lbs.  of  plates  of  old  copper  are^u    by  scUs^rs  nto  bi'ts  o^T^T"'  ""^'tk 

ward,  washed  -ulf  ptr^-;;.?^^ sK:d%1„Tvre"I^S  S  "'^'^  "^  ■^^'- 

eo^mTn^sa'lfand'bKtr^fp^reJSy  ISf  !"%"='?<?»«  '■•=  -^-  "^ 
ieft  for  so.e  ti.e  to  their  '^TLS^'-Fl.r:^;:'^^^'::^:^^-^^^:^ 


898 


VERMICELLI. 


planks  joined  withonl  iron  nails,  and  set  aside  in  a  cellar,  or  other  place  of  moderate 
temperature. 

The  saline  mixture,  which  is  partially  converted  into  sulphate  of  soda  and  chloride 
of  copper,  absorbs  oxygen  from  the  air,  whereby  the  metallic  copper  passes  into  a 
hydrated  oxide,  with  a  rapidity  proportioned  to  the  extent  of  the  surfaces  exposed  to 
the  atmosphere.  In  order  to  increase  this  exposure,  during  the  three  months  that 
the  process  requires,  the  whole  mass  must  be  turned  over  once  every  week,  with  a 
copper  shovel,  transferring  it  into  an  empty  chest  alongside,  and  then  back  into  the 
former  one. 

At  the  end  of  three  months,  the  corroded  copper  scales  must  be  picked  out,  and  the 
saline  particles  separated  from  the  slimy  oxide  with  the  help  of  as  little  water  as 
possible. 

d.  Thl8  oxidised  schalm,  or  mud,  is  filtered,  then  thrown,  by  means  of  a  bucket  con- 
taining 30  pounds,  in  a  tub,  where  it  is  carefully  divided  or  comminuted. 

e.  For  every  six  pailfuls  of  schalm  thus  thrown  into  the  large  tub,  12  pounds  of 
muriatic  acid,  at  16^^  Baume,  are  to  be  added;  the  mixture  is  to  be  stirred,  and  then 
left  at  rest  for  24  or  S6  hours. 

/.  Into  another  tub,  called  the  blue  back,  there  is  to  be  introduced,  in  like  manner 
for  everv  six  pailfuls  of  the  acidified  nchlaniy  15  similar  pailfuls  of  a  solution  of  colorlesi 
clear  caustic  alkali,  at  19®  Bauiiie. 

g.  When  the  back  (e)  has  remained  long  enough  at  rest,  there  is  to  be  poured  into  it 
a  pail  of  pure  water  for  every  pail  of  schlam. 

h.  When  all  is  thus  prepared,  the  set  of  workmen  who  are  to  empty  the  back  («)>  and 
those  who  are  to  slir  (/),  must  be  placed  alongside  of  each.  The  first  set  transfer  the 
schlam  rapidly  into  the  latter  back  ;  where  the  second  set  mix  and  agitate  it  all  the  time 
requisite  to  convert  the  mass  into  a  consistent  stale,  and  then  leave  it  at  rest  from  36  to 
48  hours. 

The  whole  mass  is  to  be  now  washed ;  with  which  view  it  is  to  be  stirred  about  with 
the  affusion  of  water,  allowed  to  settle,  and  the  supernatant  liquor  is  drawn  otf.  This 
process  is  to  be  repeated  till  no  more  traces  of  potash  remain  among  the  blue.  The 
deposiie  must  be  then  thrown  upon  a  filter,  where  it  is  to  be  kept  moist,  and  exposed 
freely  to  the  air.  The  pigment  is  now  squeezed  in  the  filler-bags,  cut  into  bits,  and  dried 
m  the  atmosphere,  or  at  a  temperature  not  exceeding  78°  Fahr.  It  is  only  after  the 
most  coniplfte  desiccation  that  the  color  acquires  its  greatest  lustre. 

VERMICELLI,  is  a  paste  of  wheat  flour,  drawn  out  and  dried  in  slender  cylinders, 
more  or  less  tortuous,  like  worms,  whence  the  Italian  name.  The  gruau  of  the  French 
is  wheat  coarsely  ground,  so  as  to  free  it  from  the  husk  ;  the  hardest  and  whitest  part, 
being  separated  by  sifting,  is  preferred  for  making  the  finest  bread.  When  this  gruau 
is  a  little  more  ground,  and  the  dust  separated  from  it  by  the  bolting-machine,  the 
granular  substance  called  semoule  is  obtained,  which  is  the  basis  of  the  best  pastes. 
The  softest  and  purest  water  is  said  to  be  necessaiy  for  making  the  most  plastic  ver- 
micelli dough ;  12  pounds  of  it  being  usually  added  to  50  pounds  of  semoule.  It  is 
better  to  add  more  semoule  to  the  water,  than  water  to  the  semoule,  in  the  act  of 
kneading.  The  water  should  be  hot,  and  the  dough  briskly  worked  while  still  warm. 
The  Italians  pile  one  piece  of  this  dough  upon  another,  and  then  tread  it  well  with 
their  feet  for  two  or  three  minutes.  They  afterwards  work  it  for  two  hours  with  a 
powerful  rolling-pin,  a  bar  of  wood  from  10  to  12  feet  long,  larger  at  the  one  end  than 
the  other,  having  a  sharp  cutting  edge  at  the  extremity,  attached  to  the  large  kneading- 
trough. 

When  the  dough  is  properly  prepared,  it  is  reduced  to  thin  ribands,  cylinders,  or 
tubes,  to  form  vermicelli  and  macaroni  of  different  kinds.  This  operation  is  performed 
by  means  of  a  powerful  press.  This  is  vertical,  and  the  iron  plate  or  follower  carried  by 
the  end  of  the  screw  fits  exactly  into  a  cast-iron  cylinder,  called  the  hell,  like  a  sausage- 
machine,  of  which  the  bottom  is  perforated  with  small  holes,  of  the  shape  and  size  in- 
tended for  Ihe  vermicelli.  The  hell  being  filled,  and  warmed  with  a  charcoal  fire  to  thin 
the  dough  into  a  paste,  this  is  forced  slowly  through  the  holes,  and  is  immediately  cooled 
and  dried  by  a  fanner  as  it  protrudes.  When  the  threads  or  fillets  have  acquired  the 
length  of  a  foot,  they  are  grasped  by  the  hand,  broken  off,  and  twisted,  while  still  flexi- 
ble, into  any  desired  shape  upon  a  piece  of  paper. 

The  macaroni  requires  to  be  made  of  a  less  compact  dough  than  the  vermicelli.  The 
former  is  forced  through  the  perforated  bottom,  usually  in  fillets,  which  are  afterwards 
formed  into  tubes  by  joining  their  edges  together  before  they  have  had  lime  to  become 
dry.    The  lazagms  are  macaroni  left  in  the  fillet  or  riband  shape. 

Vermicelli  is  made  with  most  advantage  from  the  flour  of  southern  countries,  which 
IB  richest  in  gluten.  It  may  also  be  made  from  our  ordinary  flour,  provided  an  addition 
of  gluten  be  made  to  the  flour  paste.     Vermicelli  prepared  from  ordinary  flour  is  apt 


VERMILLION. 


899 


\.. 


\ 


to  melt  into  a  paste  when  boiled  in  soups.  It  may,  however,  be  weU  made  economicaUy 

by  the  following  prescription :—  ' 

Vermicelli  or  Naples  flour  -               -               -    21  Iba 

White  potato  flour         -  -                . 

Boiling  water.               -  -               . 


-  14  — 

-  12  — 


Total 


47  lbs. 


Affording  45  lbs.  of  dough,  and  30  of  dry  vermicelli    With  gluten,  made  from  common 
Hour,  the  proportions  are : — 


Flour  as  before 
Fresh  gluten  - 
Water 


-  80  lbs. 

-  10  — 

-  7  — 


Total 


41  lbs. 


Affording  30  lbs.  of  dry  vermicelli  or  macaroni. 

r.f  y^^^^^^^l^^  ?**  6'mna6ar,  is  a  compound  of  mercury  and  sulphur  in  the  proportion 
of  100  parts  of  the  former  to  1 6  of  the  latter,  which  occurs  in  nature  as  a  common  ore  of 
quicKsiiver,  and  is  prepared  by  the  chemist  as  a  pigment,  under  the  name  of  VermiUon 
It  is,  properly  speakmg,  a  bisulphuret  of  mercury.  This  artificial  compound  being  ex- 
tensively employed  on  account  of  the  beauty  of  its  color,  in  painting,  for  making  red 
sealing-wax,  and  other  purposes,  is  the  object  of  an  important  manufacture.  When  ver- 
miUon  is  prepared  by  means  of  sublimation,  it  concretes  in  masses  of  considerable 
thickness,  concave  on  one  side,  convex  on  the  other,  of  a  needle-form  texture;  brown- 
jsh-red  m  the  lump,  but  when  reduced  to  powder,  of  a  lively  red  color.  On  exposure 
to  a  moderate  heat,  it  evaporates  without  leaving  a  residuum,  if  it  be  not  contaminated 
flame  *"    *'  *  ^^""^^  ^'  *^^*  ^''^'  *''*^  ^""""^  enUrely  away,  with  a  blue 

Holland  long  kept  a  monopoly  of  the  manufacture  of  vermilion,  from  being  alone  in 
possession  of  the  art  of  giving  it  a  fine  flame  color.    Meanwhile  the  French  chemists 
examined  this  product  with  great  care,  under  an  idea  that  the  failure  of  other  nations 
to  rival  the  Dutch  arose  from  ignorance  of  its  true  composition  ;  some,  with  BertholleU 
imagined  that  it  contained  a  little  hydrogen ;   and  others,  with  Fourcroy,  believed  that 
the  mercury  contained  in  it  was  oxydized ;    but,  eventually,  Seguin  proved  that  both  of 
these  opinions  were  erroneous;    having  ascertained,  on  the  Jne  hand,  that  no  hydro- 
fenous  matter  was  given  out  in  the  decomposition  of  cinnabar,  and  on  the  other  that 
sulphur  and  mercury,  by  combining,  were  transformed  into  the  red  sulphuret  in  close 
vessels    without  the  access  of  any  oxygen  whatever.     It  was  likewise  supposed  that 
the  solution  of  the  problem  might  be  found  in  the  difference  of  compositiorbetween 

v:L  1*  ^  ,  /"'f!'"J'^''''^"^/''"''>'5  *"^  many  conjectures  were  made  with  this 
view,  the  whole  of  which  were  refuted  by  Seguin.  He  demonstrated,  in  fact,  that  a 
mere  change  of  temperature  was  sufficient  to  convert  the  one  sulphuret  into  the  other, 
withou  occasioning  any  variation  in  the  proportion  of  the  two  elements.  Cinnabar 
r„rn  I  k"^  '"  *-^'^l'  '"^?^'  convertible  into  elhiops,  which  in  its  turn  ischan^ 
ilil  h«Mh' ^^/''^''"''f  !^'  '""^l  '^  ^  ^''^^''  temperature;  and  thence  he  was  led  to  l7 
elude  that  the  difference  between  these  two  sulphurets  was  owing  principally  to  the  state  of 
Sat  Znr  ''"  "V^"  ^«"^lit«ents.  It  would  seem  to  result,'from  all  these  research^ 
hat  cinnabar  is  only  an  intimate  compound  of  pure  sulphur  and  mercury,  in  the  pron^ 
tn^fp'^fi"^ '"'  by  analysis;  and  it  is  therefore  reasonable  to  conclude,  that  in^X; 
to  make  fine  vermilion,  it  should  be  sufficient  to  effect  the  union  of  its  element^,  at  i 
high  enough  temperature,  and  to  exclude  the  influence  of  all  foreign  matTCs  buj 
notwithstanding  these  discoveries,  the  art  of  making  good  vermilion  ?s  near'lv  i^ 
much  a  mystery  as  ever.  M.  Seguin,  indeed,  announced  in  his  Memoks,  tha"  he  ha^ 
succeeded  m  obtaming,  m  his  laboratory,  as  good  a  cinnabar  as  that  of  HoUand  and 

muchThTanfhn''  ""''V    '^"JL^^*"^^-^^^  truth  may  be  in  this  assertion,  or  however 
much  the  author  may  have  been  excited  by  the  love  of  honor  and  profit,  no  manu- 

evt"To"foreta'Z\rnfr''r'  7  "'^^?^  his  auspices.  France  is  stilf  as  tributary  i 
ever  to  foreign  nations  for  this  chemical  product.  At  an  exoosition  some  vears  LrT 
indeed,  a  sample  of  good  French  vermilion  was  brought  fXaTto  pTove  that  tlie 
problem  was  nearly  solved ;  but  that  it  is  not  so  completely,  may  be  inf^r?Id  from  the 
silence  on  this  subject  in  M.  Dupin's  report  of  the  last  exposhion  in  ISsT  w  1^^^  we 
.Tow  "Sptr?'  '"'^^  '^"""'^  "'^^  eulogiums  anrSlsVthe  jud^^^^^^^^^ 
of'r;iing.wai^         "'''  '"  "''^  '""''  ^^'^'y  P"^^^  ^y  '^^  ^'^»<^^  manufacturer 

CA^  J^nl'^v'  XTT^  ""^  ^^  ^"^'?  '°"'"*'  published,  long  ago,  in  the  ^rmales  de 
Vhimie,  vol.  IV.,  the  best  account  we  yet  have  of  the  manufacture  of  vermilion  in  HoUand  j 


900 


VERMILLION. 


one  which  has  been  since  verified  by  M.  Payss^,  who  saw  the  process  practised  on  th« 
great  scale  with  success. 

"  The  establishment  in  which  1  saw,  several  times,  the  fabrication  of  sublimed  sul- 
phuret  of  mercury,"  says  M.  Tuckert,  "  was  that  of  Mr.  Brand,  at  Amsterdam,  beyond 
the  gate  of  Utrecht ;  it  is  one  of  the  most  considerable  in  Holland,  producing  annually, 
from  three  furnaces,  by  means  of  four  workmen,  48,000  pounds  of  cinnabar,  besides  other 
mercurial  preparations*     The  following  process  is  pursued  here  : — 

"The  ethiops  is  first  prepared  by  mixing  together  150  pounds  of  sulphur,  with  1080 
pounds  of  pure  mercury,  and  exposing  this  mixture  to  a  moderate  heat  in  a  flat  polished 
iron  pot,  one  foot  deep,  and  two  feet  and  a  half  in  diameter.  It  never  takes  fire,  pro- 
vided the  workman  understands  his  business.  The  black  sulphuret,  thus  prepared,  is 
ground,  to  facilitate  the  filling  with  it  of  small  earthen  bottles  capable  of  holding  about 
24  ounces  of  water ;  from  30  to  40  of  which  bottles  are  filled  beforehand,  to  be  ready 
when  wanted. 

"  Three  great  subliming  pots  or  vessels,  made  of  very  pure  clay  and  sand,  have  been 
previously  coated  over  with  a  proper  lute,  and  allowed  to  dry  slowly.  These  pots  are  set 
upon  three  furnaces  bound  with  iron  hoops,  and  they  are  covered  with  a  kind  of  iron 
dome.  The  furnaces  are  constructed  so  that  the  flame  may  freely  circulate  and  play 
upon  the  pots,  over  two  thirds  of  their  height. 

*'  The  subliming  vessels  having  been  set  in  their  places,  a  moderate  fire  is  kindled  in 
the  evening,  which  is  gradually  augmented  till  the  pots  become  red.  A  bottle  of  the 
black  sulphuret  is  then  poured  into  the  first  in  the  series,  next  into  the  second  and 
third,  in  succession;  but  eventually,  two,  three,  or  even  more,  bottles  may  be  emptied 
in  at  once;  this  circumstance  depends  on  the  stronger  or  weaker  combustion  of  the 
sulphuret  of  mercury  thus  projected.  After  its  introduction,  the  flame  rises  4  and 
sometimes  6  feet  high  ;  when  it  has  diminished  a  little,  the  vessels  are  covered  with  a 
plate  of  iron,  a  foot  square,  and  an  inch  and  a  half  thick,  made  to  fit  perfectly  close. 
In  this  manner,  the  whole  materials  which  have  been  prepared  are  introduced,  in 
the  course  of  34  hours,  into  the  three  pots ;  being  for  each  pot  360  pounds  of  mercury, 
and  50  of  sulphur ;  in  all,  410  pounds." 

The  degree  of  firing  is  judged  of,  from  time  to  time,  by  lifting  oflf  the  cover ;  for  if 
the  flame  rise  several  feet  above  the  mouth  of  the  pot,  the  heat  is  too  great ;  if  it  be 
hardly  visible,  the  heat  is  too  low.  The  proper  criterion  being  a  vigorous  flame  play- 
ing a  few  inches  above  the  vessel.  In  the  last  of  the  36  hours*  process,  the  mass  should 
be  dexterously  stirred  up  every  15  or  20  minutes,  to  quicken  the  sublimation.  The 
subliming  pots  are  then  allowed  to  cool,  and  broken  to  pieces  in  order  to  collect  all  the 
Termilion  incrusted  within  them ;  and  which  usually  amounts  to  400  lbs.,  being  a  loss  of 
only  60  on  each  vessel.  The  lumps  are  to  be  ground  along  with  water  between  honzonta. 
stones,  elutriated,  passed  through  sieves,  and  dried.  It  is  said  that  the  rich  tone  of  the 
Chinese  vermilion  may  be  imitated  by  adding  to  the  materials  for  subliming  one  per 
cent,  of  sulphuret  of  antimony,  and  by  digesting  the  ground  article  first  in  a  solution  of 
sulphuret  of  potassa,  and,  finally,  in  diluted  muriatic  acid. 

The  humid  process  of  Kirchoft*  has  of  late  years  been  so  much  improved,  as  to 
furnish  a  vermilion  quite  equal  in  brilliancy  to  the  Chinese.  The  following  process 
has  been  recommended.  Mercury  is  triturated  for  several  hours  with  sulphur,  in  the 
cold,  till  a  perfect  ethiops  is  formed ;  potash  ley  is  then  added,  and  the  trituration  is 
continued  for  some  time.  The  mixture  is  now  heated  in  iron  vessels,  Aviih  constant 
stirring  at  first,  but  afterwards  only  from  time  to  time.  The  temperature  must  be 
kept  up  as  steadily  as  possible  at  130°  Fahr.,  adding  fresh  supplies  of  water  as  it  eva- 
porates. When  the  mixture  which  was  black,  becomes,  at  the  end  of  some  hours, 
brown-red,  the  greatest  caution  is  requisite,  to  prevent  the  temperature  from  being  raised 
above  1 14°,  and  to  preserve  the  mixture  quite  liquid,  while  the  compound  of  sulphur 
and  mercury  should  always  be  pulverulent.  The  color  becomes  red,  and  brightens  in  its 
hue,  often  with  surprising  rapidity.  When  the  tint  is  nearly  fine,  the  process  should  be 
continued  at  a  gentler  heat,  during  some  hours.  Finally,  the  vermilion  is  to  be  elutri- 
ated, in  order  to  separate  any  particles  of  running  mercury.  The  three  ingredients  should 
be  very  pure.  The  proportion  of  product  varies  with  that  of  the  constituents,  as  we  see 
from  the  following  results  of  experiments,  in  which  300  parts  of  mercury  were  always  ero 
ployed,  and  from  400  to  450  of  water  : — 

Sulphur.  Potash.  Vermilion  obtained. 

114  76  330 

115  75  331 
120  120  321 
150  152  382 
120  180  245 
100              180            244 

60  180  142 


I—  ^ 


VINEGAR. 


901 


The  first  proportions  are  therefore  the  most  advantageous;  the  lasf^  which  are  those  of 
M.  Kirchofi^  himself,  are  not  so  good. 

r  ^'^^^'^  ^^^^^  ^^*'  ^^  P**"^  of  quicksilver,  114  of  sulphur,  75  of  caustic  potassa,  and 
from  400  to  4o0  of  water,  form  very  suitable  proportions  for  the  moist  process :  that  the 
best  temperature  was  113°  F.;  and  that  122°  was  the  highest  limit  of  heat  compatible 
With  the  production  of  a  fine  color. 

The  theory  of  this  process  is  by  no  means  clear.    We  may  suppose  that  a  sulphuret 
of  potassium  and  mercury  is  first  formed,  which  is  eventually  destroyed,  in  proportion  as 
the  oxygen  of  the  air  acts  upon  the  sulphuret  of  potassium  itself.    There  may  also  be  p 
duced  some  hyposulphite  of  mercury,  which,  under  the  same  influence,  would  be  tr 
formed  into  sulphuret  of  mercury  and  sulphate  of  potash. 

Sulphuret  of  potassium  and  mercury  furnish  also  vermilion,  but  it  is  notbeaui».^ 
Red  oxyde  of  mercury,  calomel,  turbith  mineral,  and  the  soluble  mercury  of  Hahnemann, 
treated  with  the  sulphuret  of  potassium,  or  the  hydrosulphuret  of  ammonia,  are  all  capa- 
ble of  giving  birth  to  vermilion  by  the  humid  way. 

The  vermilion  of  commerce  is  often  adulterated  with  red  lead,  brickdust,  dragon's 
blood,  and  realgar.  The  first  two,  not  being  volatile,  remain  when  the  vermilion  is 
heated  to  its  subliming  point ;  the  third  gives  a  red  tincture  to  alcohol ;  the  fourth 
exhales  its  peculiar  garlic  smell  with  heat;  and  when  calcined  in  a  crucible  with  carbon- 
ate of  soda,  and  nitre  in  excess,  aflfords  arsenic  acid,  which  may  be  detected  by  the  usual 
cliemical  tests. 

VINEGAR  The  gross  revenue  derived  from  vinegar  manufactured  in  England  in 
the  year  1845,  amounted  to  284,817/.  yielding  a  nett  revenue  of  67,182/.  The  eross 
revenue  from  vinegar  manufactured  in  the  United  Kingdom,  in  the  same  year,  amounted 
to  311,61 1/.,  producing  a  nett  revenue  of  62,936/. 

Vinegar;  to  detect  sulphuric  acid  in.— Add  a  few  drops  of  a  concentrated  solution  of 
chloride  of  calcium  (muriate  of  lime)  to  the  vinegar  in  question,  not  the  least  turbid- 
ness  will  ensue,  even  at  a  boiling  heat  But  if  free  sulphuric  acid  be  present  in  the 
vinegar,  a  very  considerable  turbidness  will  appear,  followed  by  a  precipitate  of  sulphate 
of  lime.  If  the  proportion  of  the  sulphuric  acid  in  the  vinegar  is  larger  than  J  part, 
the  precipitate  will  appear  even  before  it  has  become  perfectly  cold.  ^^^^ 

^  In  addition  to  the  article  Acetic  Acid,  I  avail  myself  of  this  opportunity  of  describ- 
ing the  recent  invention  of  Anhydrous  Acetic  acid  as  made  by  Mr  Gerhardt  It  is 
obtained  by  mixing  perfectly  dry  fused  acetate  of  potash  with  about  half  its  weight  of 
chloride  of  benzoyle  and  applying  a  gentle  heat;  when  a  liquid  distils  over,  which, 
after  being  rectified,  has  a  constant  boiling  point  of  279^  F.,  is  heavier  than  water  with 
which  it  does  not  mix  until  after  it  has  been  agitated  with  it  for  some  time.  It  dis- 
solves at  once  in  hot  water,  forming  acetic  acid. 

Chlorbenzoyle,.  is  prepared  by  transmitting  dry  chlore  gas  through  pure  oil  of  bitter 
almonds,  till  this  at  a  boiling  heat  affords  no  more  hydrochloric  acid.  The  chlor- 
benzoyle  is  a  limpid  colorless  fluid  of  11 96  specific  gravity.  It  has  a  peculiar  very 
penetrating  smell,  drawing  tears  from  the  eyes,  as  horseradish  does.  It  has  a  hieh 
boiling  pointy  and  burns  with  a  smoky  flame.  It  dissolves  sulphur  and  phosphorus 
with  the  aid  of  heat,  and  combines  with  sulphuret  of  carbon  in  all  proportions 

Vinegar;  new  Method  for  manufacturing  pure.— The  decomposition  of  acetate  of  lime 
or  lead  by  means  of  sulphuric  acid  has  many  inconveniences,  and  there  is  danger  of  the 
product  being  contaminated  with  sulphuric  acid.  Christl*  was  therefore  induced  to 
employ  hydrochloric  acid  as  a  decomposing  agent,  and  has  found  that  when  this  acid 
18  not  used  m  excess,  the  distillate  contains  scarcely  an  appreciable  trace  of  chlorine.  A 
mixture  of  100  lb&  of  raw  acetate  of  lime,  obtained  from  the  distiUation  of  wood  and 
containing  90  per  cent  of  neutral  acetate,  with  120  lbs.  of  hydrochloric  acid  (20°  Baum6) 
IS  allowed  to  stand  during  a  night,  and  then  distilled  in  a  copper  vessel.  The  application 
of  heat  requires  to  be  gradual,  in  order  to  prevent  the  somewhat  thick  liquor  from 
running  over.  The  product  of  acetic  acid  amounted  to  100  lbs.  of  8°  Baum6-  it  had 
a  faint  yellow  color  and  empyreumatic  odor,  which  may  be  perfectly  removed  by 
ti-eatment  with  wood-charcoal  and  subsequent  rectification.  ir  j  j 

In  order  to  obtain  the  acetate  of  lime  sufficiently  pure,  Volckelf  adopts  the  following 
process  :---The  raw  pyrolignous  acid  is  saturated  with  lime  without  previous  distil- 
lation.  A  part  of  the  resinous  substances  dissolved  in  the  acid  are  thus  separated  in 
combination  with  lime.  The  solution  of  impure  acetate  of  lime  is  either  allowed  to 
stand  until  it  becomes  clear  or  filtered,  t  then  evaporated  in  an  iron  pan  to  about  one 
half,  and  hydrochloric  acid  added  until  a  drop  of  the  cooled  liquid  distinctly  reddens 
htmus-paper.     The  addition  of  acid  serves  to  separate  great  part  of  the  resin  still  held 

*  Dingler's  Polytech.  Joum. 

t  Ann.  der  Chem,  und  Pharm. 

i  A  part  ifi  distilled  off  in  a  copper  etill  in  order  to  obtain  wood-epirit 


902 


VINEGAR. 


in  solution,  which  collects  together  in  the  boiling  liquid,  and  may  be  skimmed  off,  and 
likewise  decomposes  the  compounds  of  lime  with  creosote,  and  some  other  imperfectly- 
known  volatile  substances,  which  are  driven  off  by  further  evaporation.  As  these  vol- 
atile substances  have  little  or  no  action  upon  litmus-paper,  it  being  reddened  by  the 
liquor  is  a  sign  that  not  only  are  the  lime  compounds  of  these  substances  decomposed, 
but  also  a  small  quantity  of  acetate  of  lime.  The  quantity  of  acid  necessary  for  this 
purpose  varies,  and  depends  upon  the  nature  of  the  pyrolignous  acid,  which  is  again 
dependent  upon  the  quantity  of  water  in  the  wood  from  which  it  is  obtained.  160 
litres  of  wood-liquor  require  from  4  to  6  lbs.  of  hydrochloric  acid. 

Tlie  solution  of  acetate  of  lime  is  evaporated  to  dryness,  and  a  tolerably  strong  heat 
applied  at  last,  in  order  to  remove  all  volatile  substances.  Both  operations  may  be 
performed  in  the  same  iron  pans;  but  when  the  quantity  of  salt  is  large,  the  latter  may 
be  more  advantageously  effected  upon  cast-iron  plates.  The  drying  of  the  salt  requires 
very  great  care,  for  the  empyreumatic  substances  adhere  very  strongly  to  the  acetate 
of  lime,  as  well  as  to  the  compound  of  resin  and  acetic  acid  mixed  with  it,  and  when 
not  perfectly  separated,  pass  over  with  the  acetic  acid  in  the  subsequent  distillation 
with  an  acid,  commimicating  to  it  a  disagreeable  odor.  The  drying  must  therefore  be 
continued  until  upon  cooling  the  acetate  does  not  smell  at  all,  or  but  very  slightly.  Ik 
then  has  a  dirty  brown  color.  The  acetic  acid  is  obtained  by  distillation  with  hydro- 
chloric acid  in  a  still  with  a  copper  head  and  leaden  condenser ;  when  proper  precau- 
tions are  taken,  the  acetic  acid  does  not  contain  a  trace  of  either  metal.  The  quan- 
tity of  hydrochloric  acid  required  cannot  be  exactly  stated,  because  the  acetate  of  lime 
18  mixed  with  resin,  and  already  formed  chloride  of  calcium.  In  most  instances  90  or 
95  parts  by  weight  of  acid,  1-16  spec,  grav.,  are  sufficient  to  decompose  completely  100 
parts  of  the  salt,  without  introducing  much  hydrochloric  acid  into  the  distillate. 

The  distilled  acetic  acid  possesses  only  a  very  faint  empyreumatic  odor,  very  different 
from  that  of  the  raw  pyrolignous  acid ;  it  is  perfectly  colorless,  and  should  only  become 
slightly  turbid  on  the  addition  of  nitrate  of  silver.  If  the  acid  has  a  yellowish  color, 
this  is  owing  to  resin  having  been  spirted  over  in  the  distillation.  It  is  therefore  ad- 
visable to  remove  the  resin,  which  is  separated  on  the  addition  of  hydrochloric  acid, 
and  floats  upon  the  surface  of  the  liquid,  either  by  skimming  or  filtration  through  a 
linen  cloth.  The  distilled  acid  has  a  specific  gravity  ranging  between  1058  and  1-061, 
containing  upwards  of  40  per  cent  of  anhydrous  acetic  acid.  It  is  rarely  that  acid  of 
this  strength  is  required  ;  and  as  the  distillation  is  easier  when  the  mixture  is  less  con- 
centrated, water  may  be  added  before  or  towards  the  end  of  the  distillation.  Volckel 
recommends  as  convenient  proportions — 

100  parts  of  acetate  of  lime, 
90  to  95  hydrochloric  acid, 
25  parts  of  water, 

which  yield  from  95  to  100  parts  of  acetic  acid  of  M05  spec.  grav. ;  150  litres  of  raw 
pyrolignous  acid  yield  about  60  lbs.  of  acetic  acid  of  the  above  specific  gravity. 

The  acid  prepared  in  this  way  may  be  still  further  purified  by  adding  a  small  quan- 
tity of  carbonate  of  soda  and  redistilling;  it  is  thus  rendered  quite  free  from  chlorine, 
and  any  remaining  trace  of  color  is  likewise  removed.  The  slight  empyreumatic  smell 
may  be  removed  by  distilling  the  acid  with  about  2  or  3  per  cent  of  acid  of  chromate 
of  potash.     Oxide  of  manganese  is  less  efficacious  as  a  purifying  agent 

Although  pure  acetic  acid  may  be  procured  by  the  distillation  of  vinegar,  the  whole 
of  the  acid  cannot  be  obtained  except  by  distilling  to  dryness,  by  which  means  the  ex- 
tractive substances  are  burnt,  and  the  distillate  rendered  impure.  In  order  to  obviate 
this  difficulty.  Stein*  proposes  to  add  30  lbs.  of  salt  to  every  100  lbs.  of  vinegar;  the 
boiling-pomt  is  thus  raised,  and  the  acid  passes  over  completely. 

By  the  quick  process  of  Ham,  when  the  fermentation  is  finished,  the  greatest  care 
ought  to  be  taken  that  all  access  of  air  is  excluded  from  the  wash,  and  that  its  tempe- 
rature be  reduced  to,  and  maintained  at  a  heat  below  the  point  where  acetification  com- 
mences. Those  who,  like  Messrs.  Evans,  Hill,  &  Co.,  of  Worcester,  attach  great  im- 
portance to  the  fabrication  of  the  best  keeping  vinegars,  are  in  the  habit  of  filtering  the 
fermented  wash,  and  also  of  stowing  it  away  for  many  months  in  a  cool  situation  ere 
It  18  passed  through  the  acetifier:  and  there  cannot  be  a  moment's  doubt  concerning 
the  great  value  of  this  practice,  not  only  as  regards  the  appearance  and  flavor  of  the 
resulting  vinegar,  but  also  in  respect  to  its  dietetic  and  sanitary  properties. 

All  recently  fermented  wash  contains  a  quantity  of  partially  decomposed  gluten, 
some  of  which  is  mechanically  suspended  merely,  but  by  far  the  larger  portion  exists 
m  a  state  of  solution  through  the  agency  of  carbonic  acid  gas. 


*  Polytech.  Centralblatt,  1852,  p.  395. 


V^   /. 


VINEGAR. 


903 


A  filter  will  remove  the  former,  but  time  alone  can  dissipate  the  carbonic  acid  and 
lead  to  the  deposition  of  the  latter.  At  all  events,  time  is  the  only  available  remedy, 
for  though  heat  would  expel  the  carbonic  acid,  yet  it  would  at  the  same  time  drive  oflF 
the  alcohol;  and  agitation  in  contact  with  air,  though  it  removed  the  carbonic  acid, 
would  tend  to  the  formation  of  acetic  acid,  by  which  the  gluten  would  be  kept  in  solu- 
tion more  decidedly  than  before,  and  thus  lead  to  the  production  of  a  turbid,  ropy  and 
impure  vinegar,  extremely  liable  to  decompose  and  undergo  the  putrefactive  fermenta- 
tion. It  is  obvious  therefore  that  the  theoretical  conditions  needed  in  the  treatment 
of  fermented  wort  by  the  vinegar-maker  are  precisely  those  which  we  have  shown  to 
be  in  use  at  Worcester.  That  is  to  say,  the  gluten,  when  insoluble,  should  be  removed 
by  a  filter,  and  when  held  in  solution  by  carbonic  acid,  this  must  be  slowly  expelled  by 
keeping  at  a  temperature  too  low  for  acetification  to  take  place,  and  which  may  be  as- 
sumed at  less  than  55^^  Fahr.  Fermented  wort  stowed  away  at  this  temperature  for 
six  months  will  flow  to  the  acetifier  perfectly  limpid  and  bright;  it  will  cause  no  de- 
position of  gluten  upon  the  birch  twigs,  and  thus  secure  complete  oxidation;  it  will 
rapidly  take  on  the  grateful  flavor  of  acetic  ether,  and  never  beeome  tainted  by  the 
formation  of  that  nauseous  and  noxious  product  aldehyde,  which  so  frequently  con- 
taminates ill-made  vinegar. 

Presuming,  however,  that  all  the  necessary  precautions,  with  respect  to  care  in  wash- 
ing, fermenting,  and  keeping  the  wort,  have  been  attended  to,  we  may  now  pass  on  to 
the  acetifier,  that  is  to  say  Ham's  acetifier. 

This  is  a  wooden  vat  or  vessel  (see  sketch)  about  12  feet  in  height,  and  from  Y  to  8 


1488 


DM 


§ 


mSM 


yijij  I 


e 


m 


oiei«f«f« 


tu'.WI    ,    ,    1   'IJi/ 

I^hT 

M  m 

L          / 

feet  in  diameter,  closed  at  top  and  bottom,  except  at  the  openings  for  the  introduction  of 
the  wash  and  the  exit  of  the  vinegar.  The  sides  are  perforated  by  a  few  small  holes 
for  the  admission  of  air,  and  within  are  three  floors  or  partitions  perforated  with  nu- 
merous holes  for  the  passage  of  the  wash  through  them.  Upon  these  floors  are  laid 
bundles  of  birch  twigs,  to  favor  the  dispersion  and  division  of  the  fluid  which  passes 
through  the  acetifier,  and  is  thus  brought  into  the  most  intimate  contact  with  the  oxy- 
gen contained  in  the  vessel,  or  admitted  through  the  openings  in  its  sides.  The  fluid 
or  wash  is  of  course  admitted  at  the  top  of  the  acetifier,  and  suffered  to  trickle  slowly 
through  the  masses  of  birch  twigs  and  through  the  partitions,  thus  causing  a  rapid  ab- 
sorption of  oxygen,  and  consequent  production  of  vinegar,  which  with  any  undecora- 
posed  wash  flows  out  at  the  bottom  of  the  vessel,  and  is  again  pumped  up  to  the  top, 
and  so  on  until  the  process  is  finished.  If  we  examine  the  circumstances  connected  with 
the  formation  of  vinegar  in  this  way,  we  shall  perceive  at  once,  that  it  is  a  case  of  par- 
tial combustion,  or,  in  other  words,  an  example  in  which  an  organic  compound  is  oxi- 
dized at  a  temperature  and  under  conditions  which  prevent  complete  oxidation. 

Every  one  must  have  observed  that  when  common  coals  are  thrown  upon  afire,  a  part 
immediately  bursts  into  flame,  from  which  copious  particles  of  soot  or  carbon  are  thrown 
off  unburnt,  though  of  the  other  constituent  of  the  coal,  that  is  to  say,  the  hydrogen  gat 


904 


VINEGAR. 


no  particle  escapes  unoxidized.  This  arises  from  the  fact  that,  except  at  very  high 
temperatures,  hydrogen  has  a  greater  affinity  for  oxygen  than  carbon  has;  consequent- 
ly, as  the  supply  of  oxygen  from  the  atmospheric  air  in  the  immediate  neighborhood  is 
limited,  the  hydrogen  seizes  upon  its  equivalent  to  the  exclusion  of  the  carbon  which, 
therefore  remains  and  constitutes  soot  Exactly  in  the  same  way  the  hydrogen  of  the 
alcohol  in  the  wash  oxidizes  to  the  exclusion  of  the  carbon,  and  vinegar  is  formed  from 
the  remaining  or  carbonaceous  element,  which  becomes  itself  slightly  oxidized.  Thus 
2  atoms  of  alcohol  are  composed  of: — 


Carbon       -  -  -  .  . 

Hydrogen  -  -  -  -  . 

Oxygen       -  -  -  .  . 

whilst  acetic  acid  or  pure  radical  vinegar  contains  of — 


Carbon 

Hydrogen 

Oxygen 


atoms. 

-  4 

-  6 
•    2 


atoms. 

-  4 

-  3 

-  3 


I^  therefore,  we  suppose  the  contact  of  air  with  alcohol  to  have  led  to  the  absorption 
of  oxygen,  so  as  to  have  oxidized  three  atoms  of  hydrogen,  and  thus  produced  three 
atoms  of  water,  we  have  left 


Carbon  ----.. 
Hydrogen  ----.. 
Oxygen      ----.. 

which,  by  the  mere  absorption  of  another  atom  of  oxygen,  becomes 


Carbon 
Hydrogen  - 
Oxygen 


atoms. 

-  4 
•    8 

-  8 


atoms. 

-  4 

-  8 

-  8 


or  pure  acetic  acid,  with  which  the  water  produced  from  the  hydrogen  remains  in  union 
and  forms  vinegar.  From  the  above  it  follows,  that  as  the  oxidization  of  hydrogen 
generates  heat  or  caloric,  there  ought  to  be  a  very  appreciable  rise  in  temperature 
during  the  passage  of  the  wort  through  the  acetifier.  And,  in  practice,  this  is  found  to 
be  the  case;  so  that  precautions  are  needed  to  prevent  the  heat  from  rising  so  high  as  to 
vaporise  the  remaining  alcohol  of  the  wash.  The  temperature  sought  to  be  obtained 
18  about  90°  or  92°  Fahr.,  at  which  oxidation  goes  on  freely,  and  the  loss  of  alcohol  is 
moderate.  In  using  the  word  moderate,  we  speak  practically  rather  than  chemically 
for  m  reality  the  loss  is  very  serious  with  strong  worta  From  practical  results,  con- 
ducted with  more  than  ordinary  care,  we  have  ascertained  that  about  one-third  of  all 
the  extractive  matter  of  the  malt  and  grain  is  lost  or  dissipated  during  the  processes  of 
fermentation  and  acetificatiou.  Thus,  a  wort  having  a  specific  gravity  of  1072  or  in 
technical  language,  weighing  about  26  lbs.  per  barrel,  afforded  a  vinegar  containing'5-4 
per  cent  of  pure  acetic  acid,  and  a  residuary  extract  of  10  lbs.  from  36  gallons.  The 
former  of  these  would  indicate  35  lbs.  of  sugar,  or  13-7  lbs.  per  barrel  of  gravity 
whilst  the  latter  shows  3-8  lbs.  per  barrel;  the  two  united  being  only  17-6  lbs.  instead 
of  26,  the  original  weight  The  loss,  therefore,  has  been  8-6  lbs.,  or  from  a  specific 
gravity  of  1072  to  less  than  1-050.  The  prodigious  destruction  of  extract  seems  to  im- 
ply that  great  improvements  may  yet  take  place  in  the  manufacture  of  vinegar. 

The  manufacture  of  vinegar,  by  Ham's  process,  is  an  extremely  interesting  operation, 
and  when  conducted  with  proper  care  furnishes  results  of  the  most  satisfactory  and 
uniform  character.  These,  however,  are  not  to  be  obtained  without  a  vast  amount  of 
e^erience  and  the  most  vigilant  attention  on  the  part  of  the  manufacturer.  Thus  a 
difference  in  the  water,  in  the  maU,  in  the  mode  of  washing,  in  the  cooling  of  the  wort 
or  in  the  fermentation  of  the  wort,  will  each  give  rise  to  modifications  in  the  acetifying 
process  which  no  subsequent  skill  or  labor  can  afterwards  rectify.  There  seems  no 
doubt  that  the  most  important  points  in  Ham's  method  are  the  cooling  and  fermentation 
of  the  wort,  though,  where  perfection  is  sought  for,  no  one  of  the  other  conditions  can 
be  omitted  or  neglected  with  impunity.  We  shall,  therefore,  proceed  to  treat  of  these 
conditions  seriatim,  rather  than  m  the  order  of  their  importance.  At  first  sight  it  might 
be  supposed  that  the  purer  the  water  the  better,  that  is  to  say,  the  less  the  amount  of 


-*=i 


«_.-  L 


VIOLET  BYE. 


905 


earthy  or  saline  constituents  the  more  valuable  the  water  would  be  for  making  vinegar. 
Experience,  however,  teaches  us  the  contrary,  and  science  confirms  the  truth  of  this 
teaching,  by  pointing  out  the  real  nature  of  the  operation.  When  pure  water  is  made  to 
act  at  a  high  temperature  upon  the  ordinary  ingredients  of  a  vinegar-maker's  mash  tun, 
it  is  not  alone  the  sugar,  gum,  and  starch  of  the  grain  which  enters  into  solution,  for 
under  such  circumstances  the  gluten  is  also  dissolved.  But  this  gluten  is  composed  of 
vegetable  albumen  and  vegetable  gelatine,  the  former  of  which,  as  is  well  known,  is 
capable  of  being  decomposed  and  precipitated  by  many  earthy  and  metallic  salts,  of 
which  the  sulphate  of  lime  is  one.  If,  therefore,  this  salt  exists  in  the  water  employed 
for  the  fabrication  of  vinegar  or  of  ale  or  beer,  the  wort  will  contain  little  or  no  vegeta- 
ble albumen;  consequently,  the  vinegar  or  beer  made  with  such  water  never  becomes 
cloudy  or  roapy,  as  happens  when  pure  water  is  used,  for  these  defects  arise  from  an 
excess  of  albuminous  matter.  The  water  used  for  making  the  celebrated  Burton  ale 
contains  a  great  deal  of  sulphate  of  lime,  and  the  spring  water  of  Worcester,  which  is 
employed  by  the  extensive  firm  of  Hill,  Evans  and  Co.,  in  that  city,  vinegar-makers, 
contains  also  a  very  large  amount  of  sulphate  of  lime,  and  no  doubt  contributes  much 
toward  maintaining  the  well-established  reputation  of  that  firm.  Whenever,  therefore, 
much  sulphate  of  lime  exists  in  water,  without  the  presence  of  any  noxious  ingredient, 
such  water  may  always  be  relied  upon  as  favorable  for  the  production  of  good  beer  and 
vinegar. 

As  regards  the  malt,  or  rather  the  mixture  of  malt  and  grain,  employed  for  the  pro- 
duction of  wort,  the  common  Scotch  distiller's  formula  is  the  best,  containing,  as  it  always 
does>  a  considerable  per-centage  of  oats,  for  the  long  husk  of  the  oat  greatly  facilitates 
the  operation  of  draining,  and  thus  secures  the  thorough  separation  of  the  wort  from  tie 
spent  grains. 

In  practice  it  is  found  necessary  to  ferment  only  two  gravities,  a  high  and  a  low, 
all  the  other  qualities  of  vinegar  being  made  by  mixing  or  diluting  these  after 
acetificatiou.  The  most  common,  and  unquestionably  the  best  gravity  for  fermentation 
is  that  which  in  technieal  language  weighs  about  20  lbs,,  or  has  a  specific  gravity  of 
1*056 ;  the  other,  or  that  intended  for  strong  or  proof  vinegar,  being  of  spec.  grav.  l.o72 ; 
this  latter  affords  a  vinegar  containing  about  5^  per  cent  of  anhydrous  acetic  acid. 

In  every  instance  the  fermentation  must  be  carried  to  its  utmost  limit  or  to  zero  at 
least,  and  in  cooling  the  wort  prior  to  fermentation,  great  care  must  be  used  to  prevent 
the  accession  of  the  acetous  fermentation  before  the  yeast  is  added ;  for  if  this  happens  to 
any  considerable  extent  the  nitrogenized  matter  of  the  yeast  is  then  permanently  retained 
in  solution  by  the  acetic  acid,  and  this  may  give  rise  to  the  inconvenience  called  the 
"  mother."  To  secure  a  perfect  vinegar  by  Ham's  process,  as  much  attention  is  required, 
during  the  cooling  and  fermentation,  as  for  the  finest  ale,  and  this  axiom  cannot  be 
too  strongly  inculcated  into  the  minds  of  vinegar-makers.  The  heat  of  the  fermenting 
tun  should  not  exceed  75°  Fahr.,  as  the  alcohol  formed  by  the  process  is  apt  at  higher 
temperatures  to  pass  off  in  considerable  quantity  with  the  carbonic  acid,  and  thus  give 
rise  to  a  loss  of  vinegar.  Presuming  that  the  fermentation  has  been  well  conducted,  and 
that  the  specific  gravity  of  the  wash  is  as  low  as  water,  or  1*000,  the  next  step  is  to  pass  it 
through  that  apparatus  which  constitutes  the  great  peculiarity  of  Ham's  process.  This 
apparatus  is  ciilled  tiie  acetifier.     See  Acetic  Acid. 

VIOLET  DYE,  is  produced  by  a  mixture  of  red  and  blue  coloiin?-matters,  which  are 
applied  in  succession.  Silk  is  dyed  a  fugitive  violet  with  either  archil  or  Brazil  wood ; 
but  a  fine  fast  violet,  first  by  a  crimson  with  cochineal,  without  tartar  or  tin  mordant,  and 
after  wasliinar,  it  is  dipped  in  the  indigo  vat.  A  finish  is  sometimes  given  with  archil. 
A  violet  is  also  given  to  silk,  by  passing  it  through  a  solution  of  verdigris,  then  through 
a  bath  of  logwood,  and,  lastly,  through  alum  water.  A  more  beautiful  violet  may  be 
communicated  by  passing  the  alumed  silk  through  a  bath  of  Brazil  wood,  and  after  wash- 
ing it  in  the  river,  through  a  bath  of  archil. 

To  produce  violets  on  printed  calicoes,  a  dilute  acetate  of  iron  is  the  mordant,  and  the 
dye  is  madder.     The  mordanted  goods  should  be  well  dunged. 

A  good  process  for  dyein?  cottons  violet,  is— first,  to  gall,  with  18  or  20  pounds  of  nut- 
galls  for  every  100  |>ounds  of  cotton  ;  second,  to  pass  the  stuff,  still  hot,  through  a  mordant 
composed  of— alum,  10  pounds;  iron-liquor,  at  1^°  B.,  and  sulpnate  of  copper,  each  5  or 
6  pounds ;  water,  from  24  to  28  gallons;  working  it  well,  with  alternate  steeping,  squeez- 
ing, airing,  dipping,  squeezing,  and  washing;  third,  to  madder,  with  its  own  weight  of 
the  root ;  and  fourth,  to  brighten  with  soap.  If  soda  be  used  at  the  end,  instead  of  soap, 
the  color  called  prune  de  monsieur  will  be  produced ;  and  by  varying  the  doses  of  the  in 
gredients,  a  variety  of  violet  tints  may  be  given. 

The  best  violets  are  produced  by  dyeing  yarn  or  cloth  which  has  been  prepared  with 
oil  as  for  the  Turkey-red  process.     See  Madder. 
For  the  violet  pruneau  a  little  nitrate  of  iron  is  mixed  with  the  alum  mordant,  which 


906 


VITRIFIABLE  PIGMENTS. 


VITRIFIABLE  PIGMENTS. 


907 


!ii; 


makes  a  black;  but  this  is  changed  into  violet pnmeau,  by  a  madder-bath,  followed  by 
a  brightening  with  soap. 

VITRIFIABLE  COLORS ;  see  Enamels,  Pastes,  Pottery,  and  Stained  Glass. 

VITRIFIABLE  PIGMENTS.  The  art  of  painting  with  vitrifiable  pigments  has  not 
kept  pace  with  the  progress  of  science,  and  is  far  from  having  attained  that  degree  of 
perfection  of  which  it  is  capable.  It  still  presents  too  many  difficulties  to  prove  a 
fertile  field  to  the  artist  for  his  labors :  and  its  products  have,  for  this  reason,  never 
held  that  rank  in  art  which  is  due  to  them  from  the  indestructibility  and  brilliancy  of 
the  colors.  The  reason  of  this  is  attributable  to  the  circumstance  that  the  production 
of  good  vitrifiable  pigments  is  mere  chance  work;  and  notwithstanding  the  numerous 

f)apers  published  on  this  subject,  is  still  the  secret  of  the  few.  The  directions  given  ia 
arger  works  and  periodicals  are  very  incomplete  and  indefinite ;  and  even  in  the  other- 
wise highly  valuable  Traite  des  Arts  Ceramiques  of  Brongniart,  the  chapter  on  the 
preparation  of  colors  is  far  from  satisfactory,  and  is  certainly  no  frank  communication 
of  the  experience  gathered  in  the  royal  manufactory  of  Sevres. 

Now  it  is  equally  important  to  art  and  science  that  as  many  persons  as  possible  should 
contribute  to  develop  this  art:  but  so  long  as  every  individual  about  to  engage  in  the 
subject  finds  himself  compelled,  as  I  was  on  commencing,  to  discover  the  knowledge  al- 
ready acquired  by  others,  but  kept  secret,  the  cost  of  time  and  trouble  requisite  is  suf- 
ficient to  frighten  most  persons,  and,  what  is  of  greatest  injury  to  the  art,  especially 
the  scientific  chemist,  from  working  on  the  subject 

The  branch  of  painting  with  vitrifiable  pigments  which  has  acquired  its  greatest  de- 
velopment is  the  art  of  painting  on  porcelain.  The  glaze  of  hard  felspar  porcelain, 
owing  to  its  difficult  fusion,  produces  less  alteration  upon  the  tone  of  a  color  of  the 
easily  fusible  pigments  than  is  the  case  in  painting  upon  glass,  enamel,  fayence,  Ac. 
The  colors  for  painting  upon  porcelain  are  all  of  them,  after  the  firing,  colored  lead- 
glasses  throughout ;  but  before  this  operation,  most  of  them  are  mere  mixtures  of  col- 
orless lead-glass,  the^wx,  and  a  pigment.  In  the  so-called  gold  colors,  purple,  violet, 
and  piuk,  the  pigments  are  preparations  of  gold,  the  productions  of  which  has  hitherto 
been  considered  as  especially  difficult  and  uncertain.  The  following  are  the  processes 
which  I  employ : — 

Light  Purple. — 5  grammes  of  tin  turnings  are  dissolved  in  boiling  nitromuriatic  acid, 
the  solution  concentrated  in  the  water  bath  until  it  solidifies  on  cooling.  The  per- 
chloride  of  tin  prepared  in  this  manner,  and  which  still  contains  a  slight  excess  of  mu- 
riatic acid,  is  dissolved  in  a  little  distilled  water,  and  mixed  with  two  grammes  of  so- 
lution of  protochloride  of  tin  of  1*700  sp.  gr.,  obtained  by  boiling  tin  turnings  in  excess 
with  muriatic  acid  to  the  required  degree  of  concentration.  Tliis  mixed  solution  of  tin 
is  poured  into  a  glass  vessel,  and  gradually  mixed  with  10  litres  of  distilled  water.  It 
must  still  contain  just  so  much  acid  that  no  turbidness  results  from  the  separation  of 
oxide  of  tin  ;  this  may  be  ascertained  previously  by  taking  a  drop  of  the  concentrated 
solution  of  tin  upon  a  glass  rod,  and  mixing  it  in  a  watch  glass  with  distilled  water.  A 
clear  solution  of  0'5  grammes  gold  in  nitromuriatic  acid,  which  must  be  as  neutral  as 
possible,  is  poured  into  the  solution  of  tin  diluted  with  10  litres  of  water,  constantly 
agitating  the  whole  time.  The  gold  solution  should  have  been  previously  evaporated 
nearly  to  dryness  in  the  water  bath,  then  diluted  with  water,  and  filtered  in  the  dark. 

On  adding  the  gold  solution,  the  whole  liquid  acquires  a  deep  red  color,  without, 
however,  any  precipitate  being  formed  ;  this  instantly  separates  upon  the  addition  of 
60  grammes  of  solution  of  ammonia.  But  if  no  precipitate  should  result,  which  may 
happen  if  the  amount  of  ammonia  was  too  great  in  proportion  to  the  acid  contained  in 
the  liquid,  and  in  which  case  the  liquid  forms  a  deep  red  solution,  the  precipitate  im- 
mediately results  upon  the  addition  of  a  few  drops  of  concentrated  sulphuric  acid.  It 
subsides  very  quickly.  The  supernatant  liquid  should  be  poured  off  from  it  as  soon  as 
possible,  and  replaced  5  or  6  times  successively  by  an  equal  quantity  of  fresh  spring 
water.  When  the  precipitate  has  been  thus  sufficiently  washed,  it  is  collected  upon  a 
filter;  and  as  soon  as  the  water  has  drained  off  completely,  removed  while  still  moist 
with  a  silver  spatula,  and  mixed  intimately  upon  a  ground  plate  of  glass  by  means 
of  a  spatula  and  grinder  with  20  grammes  of  lead-glass,  previously  ground  very  fine 
upon  the  same  plate  with  water.  The  lead-glass  is  obtained  by  fusing  together  2  parts 
of  minium  with  1  part  of  quartz  sand,  and  1  part  of  calcined  borax. 

The  intimate  mixture  of  gold-purple  and  lead-glass  is  slowly  dried  upon  the  same 
glass  plate  upon  which  it  had  been  mixed  in  a  moderately  warm  room,  carefully  pro- 
tected from  dust,  and  when  dry,  rubbed  to  a  fine  powder,  and  mixed  with  three 
grammes  of  carbonate  of  silver. 

In  this  manner  we  obtain  33  grammes  of  light  purple  pigments  from  0"6  gramme 
gold. 

The  above  proportion  of  lead-glass  and  carbonate  of  silver  to  the  gold  precipitate  holds 


good  only  for  a  certain  temperature,  at  which  the  color  must  be  burnt-in  npon  the  por- 
celain, and  which  is  situated  very  near  the  fusing  point  of  silver. 

To  obtain  the  color  with  a  less  degree  of  heat,  the  amount  of  lead-glass  added  to  the 
gold  must  be  greater,  but  that  of  the  carbonate  of  silver  lesa  The  same  holds  good 
with  respect  to  the  preparation  of  the  purple  pigment  for  glass  painting. 

The  best  purple  may  be  spoiled  in  the  baking  in  the  muffle.  When  this  is  done  at 
too  low  a  temperature,  the  color  remains  brown  and  dull ;  but  if  the  right  degree  of 
temperature  has  been  exceeded,  it  appears  pale  and  bluish.  Reducing,  and  especially 
acid,  vapors,  vapors  of  oxide  of  bismuth,  <fec.,  have  likewise  an  injurious  effect  upon  it 

Dark  purple. — The  clear  neutral  solution  of  0*5  of  gramme  gold  in  nitromuriatic  acid 
is  diluted  in  a  glass  vessel  with  10  litres  of  distilled  water,  and  mixed  under  constant 
agitation  with  7  "5  grammes  of  the  solution  of  protochloride  of  tin  of  1*700  sp.  gr.  pre- 

Eared  in  the  manner  described  above.  The  liquid  is  colored  of  a  dark-brownish  red; 
ut  the  precipitate  is  only  deposited  on  the  addition  of  a  few  drops  of  concentrated  sul- 
phuric acid.  The  supernatant  liquor  is  poured  ofl^,  and  replaced  five  or  six  times  suc- 
cessively with  an  equal  amount  of  spring  water.  The  precipitate,  which  is  sufficiently 
washed,  is  collected  on  a  filter;  and  after  the  excess  of  water  is  drained  off,  removed 
while  still  moist  with  a  spatula,  and  mixed,  exactly  as  described  for  the  liglit  purple, 
upon  a  glass  plate  with  10  grammes  of  the  above  lead-glass,  dried,  then  reduced  to  a 
fine  powder,  and  mixed  with  05  grammes  carbonate  of  silver;  it  furnishes  about  18 
grammes  of  dark  purple  pigment.  The  stated  proportion  of  lead-glass  and  carbonate 
of  silver  to  the  gold  is  for  the  same  temperature  of  firing  as  given  for  the  mixture  of 
light  purple ;  for  a  lower  temperature  and  also  for  painting  upon  glass,  the  quantity 
of  lead-glass  must  be  increased  and  that  of  the  silver  salt  diminished. 

Red  Violet. — ^The  gold  precipitate  from  Oo  grannne  gold  is  prepared  in  the  same 
manner  as  for  the  dark  purple,  and  whilst  moist  taken  from  the  filter,  and  mixed  in- 
timately upon  the  plate  of  glass  with  12  grammes  of  a  lead  glass  prepared  by  fusing  4 
parts  of  minium  with  2  parts  of  quartz  sand  and  1  part  calcined  borax ;  it  is  then  dried 
as  above,  and  reduced  to  a  fine  powder  upon  a  plate  of  glass,  but  without  any  addition 
of  silver.  The  proportion  of  lead-glass  to  gold  applies  likewise  for  the  same  degree  of 
temperature  as  in  the  case  of  the  light  and  dark  purple  pigments ;  a  lower  temperature 
requires  a  larger  proportion  of  lead-glaFs,  A  slight  addition  of  silver  to  this  pigment 
converts  the  red  violet  into  a  dark  purple ;  and  when  employed  alone  for  painting  upon 
glass,  it  gives  a  very  excellent  purple. 

Bltie  Violet. — This  same  gold  precipitate  of  0*5  grammes  gold  is  mixed,  while  still 
moist^  upon  the  glass  plate  with  10'5  grammes  of  a  lead  glass,  obtained  by  fusing  4  parts 
of  minium  with  1  of  quartz  sand,  drying  it  slowly  in  the  manner  above  mentioned,  and 
then  reducing  it  to  a  fine  powder  upon  the  glass  plate.  When  the  pigment  is  burnt-in 
at  a  lower  temperature,  a  larger  addition  of  lead-glass  is  required.  This  blue  violet 
pigment  is  more  especially  adapted  for  mixing  with  blue  pigments.  It  is  not  applicable 
to  glass  painting.  The  most  important  requisite  in  the  preparation  of  good  purple  and 
violet  vitrifiable  pigment  is  the  very  minute  state  of  division  of  the  gold  in  the  gold 
precipitate,  and  the  latter  in  the  lead-glass,  which  is  accomplished  by  mixing  the  moist 
precipitate  with  the  glass. 

By  mixing  the  light  purple  with  the  dark  purple  or  with  the  red  violet^  or  the  red 
violet  with  the  dark  purple,  in  different  proportions,  the  artist  is  able  to  produce  every 
possible  tint  of  purple  and  violet.  The  light  purple,  without  any  additional  silver, 
furnishes  an  amaranth-red  color,  like  that  seen  upon  most  of  the  porcelains  of  the  pre- 
ceding century,  when  the  peculiar  property  of  silver,  of  converting  the  amaranth-red 
into  a  rose-red  color,  does  not  appear  to  have  been  known.  Dr.  Richter,  who  at  the 
commencement  of  this  century  prepared  the  pigments  for  the  Royal  Berlin  manufactory 
of  poicelain,  appears,  however,  to  have  employed  it  for  his  purple,  as  a  very  beautiful 
rose  color  may  be  seen  upon  the  painted  porcelain  of  that  time. 

Pink.— One  gramme  of  gold  is  dissolved  in  nitromuriatic  acid;  the  solution  mixed 
with  one  of  50  grammes  of  alum  in  20  litres  of  spring  water;  then  mixed,  constantly 
agitating,  with  1-5  gramme  solution  of  protochloride  of  tin  of  1-700  specific  gravity, 
and  so  much  ammonia  added  until  all  the  alumina  is  precipitated.  When  the  precipitate 
has  subsided,  the  supernatant  liquor  is  poured  off,  and  replaced  about  10  times  succes- 
sively by  an  equal  amount  of  fresh  spring  water;  the  precipitate  is  then  collected  on 
a  filter,  and  dried  at  a  gentle  heat  It  weighs  about  135  grammes;  and  to  prepare 
the  pigment  is  mixed  with  2*5  grammes  carbonate  of  silver,  and  70  grammes  of  the 
same  lead-glass  described  under  light  purple  (2  minium,  1  quartz  sand,  1  calcined 
borax),  and  reduced  to  a  fine  powder  on  the  glass  plate. 

This  color  is  adapted  only  for  the  production  of  a  light  pink  ground  upon  porcelain, 
and  must  only  be  applied  in  a  thin  layer;  when  laid  on  a  thick  layer,  the  gold 
separates  in  a  metallic  state,  and  no  color  is  produced. 

All  the  gold  colors  above  described  do  not  furnish,  when  fused  alone  in  a  crucible^ 


'!  ■ 


908 


VITRIFIABLE  PIGMENTS. 


VITRIFIABLE  PIGMENTS. 


909 


:!i ' 


red  or  violet  glasses,  as  might  be  expected,  but  dirtj  brown  or  yellowish  glasses,  which 
appear  troubled  from  the  separation  of  metallic  gold  and  silver;  this  peculiar  beautiful 
tint  is  only  developed  when  they  are  fused  upon  the  porcelain  glaze  in  a  layer  which 
must  not  be  too  thick;  they  then  color  it  through  and  through,  as  a  piece  of  porcelain 
pamted  with  it  shows  distinctly  in  the  fracture.  If  the  layer  exceeds  a  certain  thick- 
ness, the  gold  and  silver  separate  in  a  metallic  state;  and  they  produce  either  a  liver 
color,  as  for  instance  the  purple  and  violet  pigments,  or  no  color  at  all,  as  is  the  case 
"With  the  niore  fusible  pink  pigment 

Yellow  Pigments  for  painting  upon  Porcelain.— The  yellow  vitrifiable  pigments  are 
lead-glasses,  colored  either  by  antimonie  acid  or  oxide  of  uranium.  The  antimoniate 
of  potash  18  prepared  by  igniting  1  part  of  finely  powdered  metallic  antimony  with  2 
parts  of  nitre,  in  a  red-hot  Hessian  crucible,  and  washing  the  residue  with  water  The 
oxide  of  uranium  is  obtained  in  the  fittest  state,  by  heating  the  nitrate  until  the  whole 
of  the  nitric  acid  is  expelled. 

I^non  Yellow.—^  parts  antimoniate  of  potash,  2|  parts  oxide  of  zinc,  86  parts  of 
lead-glass  (prepared  by  fusing  together  5  parts  minium,  2  parts  of  white  sand,  and 
1  part  of  calcined  borax),  are  intimately  mixed,  and  heated  to  redness  in  a  porcelain 
crucible,  which  is  placed  in  a  Hessian  crucible,  until  the  mixture  forms  a  paste;  it  is 
then  taken  out  with  a  spatula,  pounded  after  cooling,  and  ground  upon  a  plate  glasa 
If  the  pigment  is  fused  longer  than  requisite  for  the  perfect  union  of  the  ingredients, 
the  yellow  color  is  converted  into  a  dirty  gray  by  the  destruction  of  the  antimoniate 
of  lead. 

lAght  Yelloto.—A  parts  antimoniate  of  potash,  1  part  oxide  of  zinc,  and  36  parts  of 
Jead-glass  (prepared  by  fusing  together  8  parts  of  minium  and  1  part  of  white  sand! 
are  well  mixed,  fused  in  a  Hessian  crucible,  and  after  cooling,  pounded  and  ground. 
In  the  preparation  of  this  color,  long  fusion  is  less  injurious  than  with  the  preceding 
one,  owing  to  the  absence  of  the  borate  of  soda  in  the  lead-glas&  The  color  itself  S 
more  intensely  yellow  than  the  preceding  one,  and  is  extremely  well  adapted  for  mix- 
ing with  red  and  brown  pigments;  but  it  does  not  furnish  such  pure  tints  as  that  when 
mixed  with  green ;  owing  to  its  higher  specific  gravity,  it  flows  more  freely  from  the 
brush,  and  may  be  laid  on  in  a  thicker  layer,  without  scaling  off"  after  the  firing 

JJark  Yellow,!.— 4S  parts  minium,  16  parts  sand,  8  calcined  borax,  16  antimoniate 
ot  potash,  4  oxide  of  zinc,  and  5  parts  peroxide  of  iron  (caput  mortumA  are  intimately 
mixed  and  fused  m  a  Hessian  crucible,  until  the  ingredients  have  perfectly  combined, 
but  no  longer;  otherwise  the  golden  yellow  color  is  converted  into  a  dirty  gray  as  in 
the  caso  of  the  lemon-yellow  pigment 

Dark  Yellow,  2—20  parts  of  minium,  2  J  white  sand,  4|  antimoniate  of  potash.  1  part 
peroxide  of  iron  {caput  mortuum),  and  1  part  oxide  of  zinc,  are  well  mixed  and  fused 
in  a  Hessian  crucible.  Long  fusion  is  less  injurious  in  this  case  than  in  the  preceding 
Iron-rod  pigment  may  be  laid  on  and  near  this  dark  yellow  2,  without  its  beinz 
destroyed,  or  the  harmony  of  the  tints  injuriously  affected. 

For  landscape  and  figure  painting,  the  above-mentioned  yellow  pigments  should  be 
made  less  readily  fusible,  in  order  to  paint  with  them  upon  or  benlath  other  colors, 
without  any  fear  of  what  has  been  painted  being  dissolved  by  the  subjacent  or  super- 
posed  pigment  This  property  is  given  to  it  by  the  addition  of  Naples  yellow,  which 
IS  best  prepared  for  this  purpose  by  long-continued  ignition  of  a  mixture  of  1  part 
tartar-emetic,  2  parts  nitrate  of  lead,  4  parts  of  dry  chloride  of  sodium,  in  a  Hessian 
crucible,  and  washing  the  pounded  residue  with  water.  Very  useful  yellow  colors 
are  likewise  obtained  by  mixing  this  Naples  yellow  with  lead-glis;  they  are,  however 
more  expensive  than  those  above  given.  A  very  excellent  yellow  for  landscape  paintl 
ing  may  be  prepared,  for  instance,  by  mixing  8  parts  Naples  yellow  and  6  parts  lead- 
boTax)  '°^  ^  ^**'^*  ""^  minium  with  1  of  white  sand  and  1  of  calcined 

The  yellow  pigments  obtained  with  antimony,  after  being  burnt-in  upon  the  porce- 
lain appear  under  the  microscope  to  be  mixtures  of  a  yellow  transpaVent  substance 
(antimoniate  of  ead?),  and  a  colorless  glass,  and  not  homogeneous  yellow  glasses. 

UramumYellow^l  part  oxide  of  uranium,  4  parts  lead-glass  (prepared  by  fusing 
8  parts  minium  with  1  part  white  sand),  are  intimately  mixed  and  ground  upon  aglas! 

^r^A'  f  T  f  '  tT  ''  "''k  '"^u^P^"^.  ^°"  ™'^'"g  ^^^^  ^t'^^'*^'  ^ith  which  it  produces  dis- 
cordant tints      It  may  be  shaded  with  dark  purple  or  violet  ^ 

y^iZZTT  7'^^5'^— ^  parts  oxide  of  uranium,  1  part  chloride  of  silver,  and  8  parts 
bismiith  glass  (prepared  by  fusing  4  parts  of  oxide  of  bismuth  with  1  part  of  crystal- 
ized  boracic  acid),  are  intimately  mixed  and  ground  upon  a  plate  glasJ.  This  orange 
18  not  adapted  any  more  than  the  yellow  pigment,  for  being  mixed  with  other  colo^ 
When  examined  under  the  microscope,  after  being  burnt-in  upon  porcelain,  the 
uranium  pigments  appear  as  pale  yellow-colored  glasses,  in  whiJh  unaltered  ixide 


of  uranium  is  suspended.     Only  a  small  portion,  therefore,  of  the  oxide  of  uranium  has 
dissolved  in  the  fusing. 

Green  Pigments  for  painting  npon  Porcelain.  Blue  Green. — 10  parts  of  the  chromate 
of  protoxide  of  mercury  and  1  part  of  chemically  pure  oxide  of  cobalt  are  ground  upon 
a  glass  plate,  in  order  to  produce  as  intimate  a  mixture  as  possible ;  the  mixture  is 
then  heated  in  a  porcelain  tube,  open  at  both  ends,  until  the  whole  of  the  mercury  is 
expelled.  The  beautiful  bluish-green  powder  thus  obtained  is  then  transferred  into 
a  porcelain  crucible,  and  the  lid  cemented  to  it  with  glaze.  The  full  crucible  is 
exposed  to  the  highest  temperature  of  the  porcelain  furnace  during  one  firing,  the 
crucible  carefully  broken  after  the  cooling,  and  the  pigment  washed  with  water,  to 
remove  a  small  quantity  of  chromate  of  potash.  In  this  manner  a  compound  of  oxide 
of  chromium  and  oxide  of  cobalt  is  obtained  in  nearly  equivalent  proportions,  which 
possesses  the  bluish-green  color  of  verdigris. 

The  blue-green  pigment  consists  of  a  mixture  of  1  part  of  the  above  compound  of 
oxide  of  chromium  and  oxide  of  cobalt,  ^  part  of  oxide  of  zinc,  and  5  parts  of  lead-glass 
(prepared  by  fusing  together  2  parts  minium,  1  part  white  sand,  and  1  part  calcined 
borax),  which  are  mixed  and  ground  upon  the  glass  plate.  By  mixing  this  blue-green 
with  lemon-yellow,  any  desired  intermediate  tint  may  be  produced.  1  part  of  blue- 
green  to  6  parts  of  lemon-yellow,  furnishes  a  beautiful  grass-green. 

Dark  Green. — ^The  chromate  of  mercury  is  treated  separately  in  the  same  way  as 
the  mixture  of  it  with  oxide  of  cobalt  for  the  blue-green ;  and  1  part  of  the  beautiful 
green  oxide  of  chromium  thus  obtained  is  mixed  with  3  parts  of  the  same  lead-glass,  as 
given  under  blue-green,  and  ground  upon  the  glass  plate. 

Green  for  shading. — 8  parts  chromate  of  mercury  and  1  part  oxide  of  cobalt  are 
intimately  mixed,  and  exposed  in  a  shallow  dish  to  the  strongest  heat  of  the  porcelain 
furnace,  during  one  of  the  bakings.  In  this  manner,  a  compound  of  oxide  of  chromium 
and  oxide  of  cobalt  is  obtained,  of  a  greenish-black  color,  which,  mixed  with  twice  the 
weight  of  the  lead-glass  directed  for  the  blue-green,  furnishes  a  very  infusible  blackish- 
green  color,  for  shading  other  green  colors. 

"When  thin  splinters  of  the  green  pigments  of  chromium,  burnt-in  upon  porcelain,  are 
examined  under  the  microscope,  it  is  distinctly  seen  that  particles  of  the  oxide  of 
chromium,  or  of  the  oxide  of  chromium  and  cobalt,  as  suspended,  undissolved,  in  the 
colorless  lead-glass. 

Blue  Pigments  for  painting  upon  Porcelain.  Dark  Blue. — 1  part  chemically  pure 
oxide  of  cobalt  1  part  oxide  of  zinc,  1  part  lead-glass  (prepared  by  fusing  together 
2  parts  of  minium  and  1  of  white  sand),  are  well  mixed  and  fused  in  a  porcelain 
crucible,  for  at  least  3  hours  at  a  red  heat :  then  poured  out,  reduced  to  powder,  and 
ground  upon  the  glass.  When  this  pigment  cools  slowly,  it  solidifies  to  a  mass  of 
acicular  crystals.  Long-continued  fusion,  at  not  too  high  a  temperature,  is  requisite 
to  obtain  a  beautiful  tint;  this  is  best  attained  by  fusing  it  during  one  of  the  bakings 
in  the  second  floor  of  the  porcelain  furnace ;  this  is  also  the  cheapest  and  best  way  of 
fusing  the  lead  glasses. 

Light  Blue. — 1  part  oxide  of  cobalt  2  parts  oxide  of  zinc,  6  parts  lead-glass  (pre- 
pared by  fusing  together  2  parts  of  minium  and  1  of  white  sand),  and  1|  part  lead- 
glass  (prepared  by  fusing  together  2  parts  of  minium,  1  part  white  sand,  and  1  part 
calcined  borax),  are  well  mixed  and  fused,  as  directed  for  the  dark  blue. 

Blue  for  shading.  — 10  parts  oxide  of  cobaU,  9  parts  oxide  of  zinc,  26  parts  of  lead- 
glass  (obtained  by  fusing  2  parts  of  minium  and  1  of  white  sand),  and  5  parts  of 
lead-glass  (prepared  by  fusing  together  2  parts  of  minium,  1  part  of  white  sand,  and 
1  part  of  calcined-borax),  are  mixed  and  fused,  as  directed  for  the  dark  blue.  The 
color  is  only  used  for  shading,  or  to  be  applied  upon,  or  beneath,  the  two  preceding 
blue  pigments,  for  which  purpose  it  is  admirably  suited  from  its  being  very  difficult 
of  fusion. 

Sky  Blue. — 2  parts  of  park  blue,  1  part  oxide  of  zinc,  and  4  parts  of  lead-glass  (pre- 
pared by  fusing  4  parts  minium  with  1  of  white  sand),  are  intimately  mLved  and 
ground  upon  the  glass  jilate.  This  pigment  is  employed,  either  alone,  or  mixed  with 
other  colors,  only  for  painting  the  sky  in  landscape. 

Tlie  blue  pigments  described  likewise  appear  under  the  microscope,  after  having 
been  burnt-in  upon  the  porcelain,  not  to  be  homogeneous  blue  glasses,  but  mixtures  of 
a  transparent  blue  substance  (silicate  of  cobalt  and  zinc  ?),  and  a  colorless  glass. 

Turquoise  Blue. — 3  parts  of  chemically  pure  oxide  of  cobalt  and  1  part  of  pure 
oxide  of  zinc,  are  dissolved  together  in  sulphuric  acid;  then  an  aqueous  solution  of 
40  parts  ammonia-alum  added,  the  mixed  solutions  evaporated  to  dryness,  and  the 
residue  heated  to  expel  the  whole  of  the  water ;  then  reduced  to  a  powder,  and  exposed 
in  a  crucible  to  an  intense  red  heat  for  several  hours.  The  color  is  most  beautiful, 
when  it  has  been  exposed,  during  one  firing,  to  the  heat  of  the  porcelain  furnace.  It 
U  a  combination  of  nearly  4  equivs.  alumina,  3  equiva  oxide  of  cobalt  *nd  1  equiv. 


910 


VITRIFIABLE  PIGMENTS. 


oxide  of  zmc,  and  is  of  a  beautiful  turquoise-blue  color.  When  the  oxides  are  mixed 
m  other  proportions  than  those  above  given,  they  do  not  furnish  such  beautiful 
colored  compounds.  To  impart  to  it  a  slightly  greenish  tint,  a  little  moist  recently 
precipitated  prot^chromate  of  mercury  is  mixed  with  the  above  described  solution  of 
ammonia-^alura  zinc,  and  cobalt ;  with  the  above  quantities,  i  part  of  the  chromat6L 
calculated  in  the  dry  state,  suffices.  ^°  "    ««^ 

The  turquoise-blue  yitrifiable  pigment  is  prepared  by  mixing  1  part  of  the  compound 
of  alumma-oxide  of  zinc  and  cobalt  with  two  parts  of  bismuth  glass  (prepared  bv  fu- 
smg  5  parts  of  oxide  of  bismuth  with  1  part  of  crystallized  boracic  acidl 

Ihe  receipt  for  the  preparation  of  the  turquoise-blue  pig.i.ent,  communicated  in  the 
J}-a?tedex  Arts  Ceramignes  by  Brongniart,  is  incorrect;  for  a  lead-glass  of  the  compo- 
sition there  given  (3  parts  minium.  1  part  sand,  1  part  boracic  acid)  destroys  the  tur- 
quoise-blue  pigment  entirely  on  fusion,  and  only  a  dirty  bluish  gray  color  is  produced. 
Un  examining  under  the  microscope  the  turquoise-blue  pigment  burnt-in  upon  porcelain. 
It  appears  to  be  a  mixture  of  a  transparent  blue  substance  and  a  colorless  glass.  The 
transparent  blue  substance  in  all  probability  is  the  above  described  compound  of  oxide 
ol  cobalt  and  alumina,  which  is  of  itself  transparent  under  the  microscope,  but  the 
transparency  of  which  is  increased  by  the  surrounding  fused  glass  of  bismuth,  just 
like  the  fibres  of  paper  by  oil.  This  is  probably  the  case  also  with  the  microscopic 
blue  constituent  of  the  other  blue  vitrifiable  figments,  and  which  is  probably  silicate 
povvde^r""     cobalt;  for  this,  when  prepared  separately,  forms  a  pure  blue  transparent 

Black  and  Gray  Colors  for  painting  upon  Porcelain.  Iridium  5/«cAr.— Iridium,  as  ob- 
tamed  in  commerce  from  Russia  in  the  state  of  a  fine  gray  powder,  is  mixed  with  an 
equal  weight  of  calcined  chloride  of  sodium,  and  heated  to  a  faint  red  in  a  porcelain  tube, 
through  which  a  current  of  chlorine  is  passed.  In  this  manner  a  portion  of  the  iridium 
18  converted  into  the  bichloride  of  iridium  and  sodium,  which  is  dissolved  out  with  water 
from  the  Ignited  mass.  The  aqueous  solution  of  the  double  salt  is  evaporated  to  dryness 
with  carbonate  of  soda,  and  then  extracted  with  water,  which  furnishes  black  sesquioxide 
olmdium.  This  18  dried  and  mixed  with  twice  its  weight  of  lead-glass  (prepared  by 
fusing  together  12  parts  of  minium.  3  parts  of  white  sand,  and  1  part  of  calcined  boraxl 
and  ground  upon  a  plate  of  glass.  The  iridium,  which  remained  undecomposed  in  the 
first  treatment  with  sea  salt  and  chlorine,  is  again  submitted  to  the  same  treatment 

iridium  Crraj/.—l  part  of  the  sesquioxide  of  iridium,  4  parts  of  oxide  of  zinc  and  22 
parts  of  lead  glass  (prepared  by  fusing  together  5  parts  of  minium,  2  parts  of  sand  and 
l  part  of  calcined  borax)  are  intimately  mixed  and  ground  fine  upon  a  plate  of  fflasa. 
Un  microscopical  examination  of  the  iridium  pigments  after  they  have  been  burnt-in 
upon  norcelain,  the  sesquioxide  iridium  is  seen  to  be  suspended  in  the  transparent 
lused  lead-glass.  It  is  owing  to  the  unalterability  of  the  sesquioxide  of  iridium  that  it 
admits  of  being  mixed  with  all  other  vitrifiable  colors  without  injuriously  affecting  the 

p;  ";  '1        ^^®^  ^^^^  ^"  ^^®  ***^^^  vitrifiable  gray  and  black  pigments. 

mack  from  Cobalt  and  Manganese.— 2,  parts  of  sulphate  of  cobalt  deprived  of  its  water 
01  crystallization  2  parts  of  dry  protosulphate  of  manganese,  and  5  parts  of  nitre,  are 
intimately  mixed,  and  heated  to  redness  in  a  Hessian  crucible  until  the  whole  of  the 
mtre  is  decomposed.  The  calcined  mass,  exhausted  with  boiling  water,  furnishes  a 
aeep  black  powder,  which  consists  of  a  combination  of  oxide  of  cobalt  and  oxide  of 
manganese.  1  part  of  this  compound  is  mixed  with  2^  parts  of  lead  glass  (prepared 
by  fusing  together  6  parts  of  minium,  2  parta  of  sand,  and  1  part  calcined  boraxV  and 
ground  fine  upon  a  plate  of  glass.  ^ 

Gray  from  Cobalt  and  Manganese.— 2.  parts  of  the  above  compound  of  the  oxide  of 
coba  t  and  manganese,  1  part  oxide  of  zinc,  and  9  parts  of  Igad-glass  (prepared  by  fu- 
sing  together  5  parta  of  minium,  2  parta  of  sand,  and  1  part  of  calcined  borax)  are  mixed 
and  ground  fine.  ' 

These  black  and  gray  pigments  are  far  less  expensive  to  prepare  than  those  from  irid- 
ium, and  are  not  inferior  to  them  in  color ;  but  they  do  not  mix  so  well  with  other 
color.*,  and  when  baked  several  times  they  vary  their  tint  somewhat,  which  renders 
their  application  less  certain.  When  these  colors  burnt-in  upon  porcelain  are  ex- 
amined  under  the  microscope,  it  is  seen  that  the  oxide  of  cobalt  and  manganese  is  not 
dissolved  by  the  lead-glass,  but  merely  suspended  in  it 

liesides  these  colors  a  very  infusible  black  is  used  in  painting,  which  is  not  acted 
upon  by  the  superposed  colors  in  the  fusion ;  it  is  the        ^  ^' 

Ground  Black  whkh  consists  of  5  parts  of  blue  violet  (gold  purple),  If  part  of  oxide 
of  manganese  and  cobalt,  and  If  part  of  oxide  of  zinc;  these  are  intimately  mixed  and 
ground  fine  upon  a  plate  of  glass.  "^ 

IV/nte  for  covering.— 1  part  minium,  1  part  white  sand,  and  1  part  crystellized  boracic 
acd,  are  well  mixed,  and  fused  in  a  porcelain  crucible.  This  white  enamel  has  the  pe- 
culiarity  of  forming  colorless  clear  glass  when  quickly  cooled  for  instance,  when  poured 
into  water ;  while,  when  slowly  cooled,  it  remains  perfectly  white  and  opaque.   On  heat- 


VITRIFIABLE  PIGMENTS. 


911 


ing  the  clear  glass  to  its  melting  point  it  loses  its  transparency,  and  becomes  opaque  as 
before.  This  property  it  possesses  in  common  with  the  enamels,  the  opacity  of  which 
is  produced  by  arsenic  or  tungstic  acid:  probably  the  opacity  in  the  present  case  is 
produced  by  the  separation  of  silicate  of  lead,  as  in  the  white  enamels  by  arseniate  or 
tungstate  of  potash  or  by  oxide  of  zinc  It  is,  however,  of  excessive  minuteness;  for 
under  the  microscope,  even  with  the  highest  power,  the  glass  merely  exhibits  a  yellow- 
ish turbidness,  and  no  individual  particles  are  visible. 

This  white  serves  for  marking  the  lightest  part  of  the  pictures,  where  it  is  impossible 
to  produce  them  by  exposing  the  bare  surface  of  the  white  porcelain ;  it  is  also  frequently 
mixed  in  small  quantity  with  the  yellow  and  green  pigments,  to  make  them  cover  well. 

LeadFlxix. — A  colorless  lead-glass  for  touching-up  those  parts  of  the  painting  which 
have  remained  dull,  and  for  mixing  with  those  pigments  which  are  not  easy  of  fusion, 
is  obtained  by  mixing  together  6  parts  of  minium,  2  parts  of  white  sand,  and  one  part 
of  calcined  borax. 

Red  and  Broxon  virtrifiable  Pigments  derived  from  Peroxide  of  Iron  for  painting  upon 
Porcelain. — Yellow  Red — Anhydrous  sulphate  of  the  peroxide  of  iron  is  heated  to  red- 
ness on  a  dish  in  an  open  muffle,  and  constantly  stirred  with  an  iron  spatula  until  the 
greater  portion  of  the  sulphuric  acid  has  been  expelled  and  a  sample  mixed  with  water 
upon  a  glass-plate  exhibits  a  beautiful  yellowish-red  color;  after  cooling,  the  peroxide 
of  iron  is  freed  by  washing  with  water  from  any  undecomposed  sulphate,  and  dried. 
To  prepare  the  pigment  7  parts  of  the  yellowish-red  peroxide  of  iron  are  well  mixed 
with  24  parts  of  lead-glass  (prepared  by' fusing  together  12  parts  of  minium,  3  parts  of 
sand,  and  1  part  of  calcined  borax)  and  ground  fine  upon  a  plate  of  glass. 

Broton  Red — When  the  persulphate  of  iron  is  heated  to  redness  until  the  whole  of 
the  sulphuric  acid  is  expelled,  and  a  sample  exhibits  a  dark  red  color,  the  peroxide  of 
iron  is  well  suited  for  a  brownish  red  pigment  which  is  prepared  in  the  same  manner 
as  directed  for  the  yellowish  red. 

Bluish  Red  (Pompadour).— When  the  persulphate  is  heated  still  more  strongly,  it  is 
deprived  of  its  loose  consistence,  becomes  heavier,  and  acquires  a  bluish  red  color.^  To 
hit  this  point  exactly  when  the  oxide  of  iron  has  assumed  the  desired  carmine  tint  is 
not  so  easy,  as  it  changes  very  rapidly  at  these  temperaturea 

The  pigment  is  prepared  by  mixing  2  parts  of  the  purple  colored  peroxide  of  iron 
with  6  parts  of  lead-glass,  obtained  by  fusing  together  5  parts  of  minium,  2  parts  of  sand, 
and  one  part  of  calcined  borax.  ^ 

Chestnut  Brown. — This  color  of  various  shades,  even  to  black,  is  acquired  by  the 
peroxide  of  iron,  at  still  higher  degrees  of  heat  than  required  for  the  preparation  of  red 
colors ;  the  pigments  are  prepared  by  mixing  2  parts  of  the  chestnut-brown  peroxide 
of  iron  with  6  parts  of  lead  glass,  prepared  by  fusing  together  12  parts  of  minium,  3 
parts  of  sand,  and  1  part  of  calcined  borax. 

Chamois.—!  part  of  the  hydrate  of  the  peroxide  of  iron,  prepared  by  precipitating 
the  peroxide  of  iron  with  ammonia,  is  mixed  with  4  parts  of  the  lead-glass,  described 
in  the  preceding,  and  the  mixture  ground  fine  on  a  plate  of  glass.  This  color  is  laid 
on  very  thin,  and  serves  to  produce  a  yellowish  brown  ground. 

Flesh  color. — 1  part  red  peroxide  of  iron,  4  parts  of  dark  yellow  2,  and  10  parts  of 
lead-glass,  prepared  as  described  under  chestnut-brown,  as  well  mixed  and  ground 
fine  upon  a  plate  of  glass.  This  color  can  also  only  be  employed  in  a  thin  layer. 
Various  tints  may  be  given  to  it  by  mixing  it  with  a  red  peroxide  of  iron,  sky-blue 
or  dark  yellow  2.  The  red  of  the  cheeks  and  lips  are  painted  upon  it  with  Pompa- 
dour red. 

When  the  above  colors  are  burnt-in  upon  porcelain,  it  is  distinctly  seen  under  the 
microscope  that  the  peroxide  of  iron  is  suspended  unaltered  in  their  clear  lead-glass; 
at  least  the  quantity  dissolved  by  the  fused  lead-glass  is  so  small  that  it  is  not  percepti- 
bly colored. 

Various  Brown  Pigments  for  painting  upon  Porcelain. — Light  Brown  1. — 6  parts  of 
dry  protosulphate  of  iron,  4  parts  of  dry  sulphate  of  zinc,  and  13  parts  of  nitre  are  well 
mixed  and  heated  to  redness  in  a  Hessian  crucible,  until  the  whole  of  the  nitre  is  de- 
composed. When  cold,  the  crucible  is  broken,  the  residue  removed,  and  separated  by 
boiling  with  water  from  soluble  matters.  A  yellowish  brown  powder  remains,  which 
is  a  combination  of  oxide  of  zinc  with  peroxide  of  iron.  The  pigment  is  made  by  mix- 
ing 2  parts  of  this  compound  with  5  parts  of  lead-glass,  prepared  for  fusing  together  12 
parts  of  minium,  3  parts  of  sand,  and  one  part  of  calcined  borax. 

Light  Brown  2. — 2  parts  of  dry  sulphate  of  iron,  2  parts  of  dry  sulphate  of  zinc,  and 
5  parts  of  nitre,  are  treated  in  the  same  manner  as  above  described  for  light  brown  1. 
The  resulting  compound  of  oxide  of  zinc  and  iron  is  of  a  higher  tint;  the  pigment  is 
prepared  from  it  as  above. 

Light  Brown  3. — 1  part  of  dry  sulphate  of  iron,  2  parts  of  dry  sulphate  of  zinc,  and 
4  paits  of  nitre  are  treated  as  directed  for  1  and  2. 


mrtijft 


tt 


t*—t« 


912 


VITRIFIABLE  PIGMENTS. 


The  light  brown  colors,  after  having  been  burnt-in  upon  porcelain  exhibited  iin«1«i 

..L^f'  •'  ^*^%^«5"^t.ng  beautiful  dark  reddish  brown  combination  JtheoxTdes  of 

nf  ^^T"  ^T"^--!  P*""^  ""^  hydrated  peroxide  of  iron  is  intimately  mixed  with  2  carta 
of  the  chroniate  of  the  protoxide  of  mercury,  and  then  heated  to  re^ne^i^  a  disr^ 

of  troxMef  if 'chromium  r'^^'  ''  ''''  '^■'''T^'  7^^  ^^^^  reddish  brX'cLpound 
oi  me  oxiaes  oi  cftromium  and  iron  is  mixed  with  3  times  its  wpio-hf  r,f  loo/i\,i«»- 

prepared  by  fusing  together  5  parU  of  minium,  2  parts'^J^raVd?  aid  f  pari  ^ftlctel 

i\\Zt?,  t^^'^'''^\  "°^^^  the  microscope,  after  being  burnt-in  upon  porcelain  these 
different  brown  colors  also  show  that  the  dark  compounds  are  mere?rsusnended  hJ 
the  lead  glass,  and  not,  or  merely  to  a  small  extent,  dissolved  TheXpofTn  pKni^ 
IZT  \V'^P^'%'^^  colored  combinations  of  the  oSdes In  tL  drv  wlrfof  Z 

tt' p^eTiStl^^^^^^^  P^^T"^  ^«  <^^-^P-  -^  ™-e"Sait'tha: 

wash^ed TeciD?tatP  ^LTJ  ''"'  by  carbonate  of  soda  and  calcination  of  the 

wasnea  precipitate,  which  also  answers.     If,  however,  the  several  nxJrlps  w^ro  f«  kI 

^nrf  ..'f  •    I'''  ^'t^^'''  separately,  instead  of  comb  ned,  t^e  colo^s^;^^^^^^^         t 
pure  that  is  to  say  they  would  exhibit  after  the  firing  different  tiZ  inTih\nv\^t 
thm  layer;  they  would  moreover  possess  a  totally  different  2rb.Ll  X     k      -^ 
^T:^  ^'^^^^^"^^^  '^^^^  ^^^^  operatio^n,'^Xl?SYhi^t:^^^^^^^^^^ 
«f  fti  f  7^^V'  ?^^i^^^'  according  to  the  process  of  Ladersdorfl^  by  mixing  a  solution 

Distilled  water         -  -  .  . 

Solution  of  gum-arabic  -  .  . 

do      of  tin  salt    -  -  -  . 

do      of  gold 

i!;l?f'*-'"5^^''''l''^/^  ^:^^^  'P'^-  ^^^^  ^"til  t»»e  liquid  begins  to^row  turbid     THa 
purple  is  deposited  and  washed  with  Rnirlf  nf  n-oka     ti  ^  "i  .  j»^"^  puroia.     ihe 


3  ozs. 
28gr8. 
14   .. 
-    23 


VORTEX  WATER  WHEEL. 


913 


small  portions  until  no  more  is  dissolved ;  the  solution  must  be  effected  slowly,  on 
which  account  the  vessel  containing  the  mixture  should  be  placed  in  snow  or  cold 
water.  The  carefully  decanted  solution  is  diluted  with  80  times  its  weight  of  distilled 
•water,  and  mixed  with  a  solution  of  gold,  prepared  according  to  the  above  directions. 
The  precipitate  is  purple-red,  and  remains  so  after  drying.  The  tin  solution  for  this 
pumose  cannot  be  preserved  long,  otherwise  nitric  ether  is  formed ;  and  the  higher 
oxidation  of  the  tin  salt  no  longer  furnishes  such  beautiful  precipitates  with  gold  »3  the 
recently  prepared  solution. 

For  mixing  with  the  purple  in  order  to  produce  a  rose  color,  the  author  does  not 
employ  carbonate  of  silver,  but  the  metal  in  a  very  minute  state  of  division,  obtained 
by  mixing  the  finest  silver  leaf  with  honey  and  a  few  drops  of  ether,  and  well  grinding 
iti  when  the  honey  is  washed  out  with  water.  Mr.  "Waechter  uses  as  a  flux  for  the 
purple  colors  a  lead-glass,  consisting  of  6  parts  minium,  2  parts  silica,  and  2  parts  cal- 
cined borax. 

With  respect  to  the  chrome  colors,  he  observes,  that  the  expensive  method  for  their 
preparation  by  means  of  the  chromate  of  the  protoxide  of  mercury  is  still  the  only  one 
by  means  of  which  a  fine  color  can  be  obtained. 

Cobalt  Colors. — In  purifying  the  cobalt  for  porcelain  colors,  the  removal  of  the 
whole  of  the  arsenic  is  of  less  consequence  than  that  of  the  iron.  Cobalt  ores  from 
various  localities,  Tunaberg,  Saxony,  and  Thuringia,  are  treated  in  the  following  man- 
ner. The  mineral  is  reduced  to  a  fine  power  in  an  iron  mortar,  kept  for  the  purpose, 
and  mixed  with  1-6  its  weight  of  charcoal  powder ;  then  exposed  in  Hessian  crucibles  to 
a  red  heat  under  a  chimney  with  a  good  draught  or  in  the  open  air,  and  roasted  as 
long  as  arsenical  vapors  escape,  a  very  disagreeable  operation,  which  lasts  several 
hours.  The  ore  thus  prepared  is  now  boiled  over  the  fire  with  a  mixture  of  4  parts 
nitre,  and  1  part  muriatic  acid,  1  part  of  which  is  diluted  with  2  parts  of  water.  This 
operation  is  repeated  about  3  times,  with  less  acid.  The  liquids  are  allowed  to  settle, 
the  clear  portion  decanted,  the  remainder  diluted  with  water  and  filtered,  and  the  solu- 
tion evaporated  to  dryness.  The  dry  yiass  is  mixed  with  some  water,  heated,  and 
separated  by  filtration  from  the  residue  of  arseniate  of  iron.  The  green  liquid,  which 
now  contains  more  or  less  cobalt,  iron,  nickel,  and  manganese,  is  mixed  with  a  filtered 
solution  of  pearlash,  until  the  dirty  reddish  precipitate  begins  to  turn  blue.  Care  and 
experience  in  this  operation  are  requisite,  otherwise  a  loss  of  cobalt  might  result. 
The  precipitate  of  arseniate  and  carbonate  of  iron,  which  at  the  same  time  contains 
nickel  and  manganese,  is  separated  by  filtration,  and  the  beautiful  red  liquid  mixed 
with  nriore  of  the  solution  of  pearlash  until  the  whole  of  the  cobalt  is  precipitated ;  the 
precipitate  is  carefully  washed  and  dried.  The  hydrated  oxide  of  cobalt  is  sufficiently 
pure  for  technical  purposes,  and  answers  just  as  well  as  that  prepared  from  oxalate  of 
cobalt  or  by  caustic  ammonia. 

For  painting,  the  oxide  of  cobalt  is  heated  in  a  Hessian  crucible  with  1  part  silica, 
and  Ij^  part  of  oxide  of  zinc  for  two  hours  in  a  blast  furnace,  then  reduced  to  a  fine 
powder  in  a  porcelain  mortar,  and  mixed  with  an  equal  weight  of  lead-glass. 

Yelloip  color. — A  beautiful  yellow  is  obtained  from  2  oz.  minium,  ^  oz.  Siib.  oxydat. 
alb.  abl,  2  drms,  oxide  of  zinc,  2  drms.  2  scruples  calcined  borax,  \  oz.  silica,  \  drm. 
dry  carbonate  of  soda,  and  1  scruple /«?rr.  oxydat.  fuscum.  which  are  well  mixed,  fused 
in  a  crucible,  and  then  ground  fine. —  Waechter. 

VITRIOL,  from  vitnim,  glass,  is  the  old  chemical,  and  still  the  vulgar  appellation  of 
sulphuric  acid,  and  of  many  of  its  compounds,  which  in  certain  states  have  a  glassy 
appearance:  thus — 

Vitriolic  acid,  or  oil  of  vitriol,  is  sulphuric  acid  ;  blue  vitriol,  is  sulphate  of  copper; 
green  vitriol,  is  green  sulphate  of  iron ;  vitriol  of  Mars,  is  red  sulphate  of  iron ;  and 
white  vitriol,  is  sulphate  of  zinc. 

VORTEX  WATER  WHEEL.  Numberless  are  the  varieties,  both  of  principle 
and  of  construction,  to  be  met  with  in  the  mechanisms  by  which  motive  power  may 
be  obtained  from  falls  of  water.  The  chief  modes  of  action  of  the  water  are,  however, 
reducible  to  three,  as  followa  First:— The  water  may  act  directly,  by  its  weight,  on 
a  part  of  the  mechanism  which  descends  while  loaded  with  water,  and  ascends  while 
free  from  load.  Tlie  most  prominent  example  of  the  application  of  this  mode  is 
afforded  by  the  ordinary  bucket  water  wheel.  Second:  The  water  may  act  by  fluid 
pressur^  and  drive  before  it  some  part  of  the  vessel,  by  which  it  is  confined.  This  is 
the  mode  in  which  the  water  acts  in  the  water-pressure-engine,  analogous  to  the 
ordinary  high  pressure  steam-engine.  Third  :  The  water,  having  been  brought  to  ito 
place  of  action,  subiect  to  the  pressure  due  to  the  height  of  its  fall,  may  be  allowed  to 
issue  through  small  orifices  with  a  high  velocity,  its  inertia  being  one  of  the  forces 
essentially  involved  in  the  communication  of  the  power  of  the  mechanism.  Throughout 
the  general  class  of  wheels  called  Turbines,  which  is  of  wide  extent,  the  water  acU 
according  to  some  of  the  variations  of  which  this  third  mode  is  susceptible.    The  name 

Vol.  11—58. 


'**^ 


914 


VORTEX  WATER  WHEEL. 


VORTEX  WATER  WHEEL. 


915 


l|j 


1489 


Turbine  s  derived  from  the  Latin  word  turho,  a  top,  because  the  wheels  to  which  it  if 
applied  almost  all  spin  round  a  vertical  axis,  and  so  bear  some  considerable  resemblance 
to  the  top.  In  our  own  country,  and  more  especially  on  the  continent  turbines  have 
attracted  much  attention,  and  many  forms  of  them  Ue  been  made  knowT  by  pub! 
hshed  descriptions.  The  object  of  the  present  article  is  to  give  an  account  of  a  new 
water  wheel  belonging  to  the  same  general  class,  which  haf  been  recentlv  invent"? 
patented,  and  brought  successfully  into  use,  by  Mr.  James  Thompson  of  Sast  In  hii 
machine,  the  moving  wheel  is  placed  within  l  chamber  of  a  neaHrcircu^^ar  fo^  T^^^^ 
water  is  injected  into  the  chamber  tangentially  at  the  circumfrenee  an7ihul  it 
receives  a  rapid  motion  of  rotation.  Ritainin/  this  motion,  h  paTes  towards  the 
centre,  where,  alone  it  is  free  to  make  it^  exit  The  wheel,  ^hichrplacld  Within 
numhr.f  '  ""fj"^''^  ^^'"-^  ^SJire'y  ^^^  '^^  is  divided  by  thin  partitioKto  a  g^Lt 
number  of  radiating  passages.     Through  these  passages  the  water  must  flow  in  its 

wheel'  *T:  wh-^1  ''Tf '  ""f'  ^"  ^"^'^^  ?«'  ''  ^^P-'^'^^  own  rotatory  moUon  to  th^ 
Zaf        7  u-  ^^^^  Poo^  ?^  ^ater,  acting  within  the  wheel  chamber,  being  one  principal 

tfiz:[T::i:^r' '''''  ^^  *'^  ^^"^^  ^^^'-'  -  ^  -'^^^^^  'desigLti:/forThe 

th  Jone''adn'nf .'a  T.l^'l  ?^f  7?f^^  ™?^««  ^J  construction  ;  but  the  two  principal  forms  are 
the  one  adapted  for  high  falls,  and  one  for  low  falls.  The  former  may  be  called  the 
high  pressure  vortex  and  the  latter  the  low  pressure  vortex.  An  example  of  each  of 
these  two  kinds  is  delineated  in  the  accompanying  figures  ^ 

I'lffs,  1489  and  1490  are  respectively  a  vertical  section  and  a  plan  of  a  vortex  recently 

^'"*°  constructed  for  employing  a  very 

high  fall  near  Belfast  to  drive 
a  flax-mill*  a  a  is  the  water 
wheel.  It  is  fixed  on  the  up- 
right shaft  B,  which  conveys 
away  the  power  to  the  machi- 
nery to  be  driven.  The  water 
wheel  occupies  the  central  part 
of  the  upper  division  of  a  strong 
east-iron  case  c  c  This  part  of 
the  case  is  called  the  wheel 
chamber.  D  d  is  the  lower 
divison  of  the  case,  and  is 
called  the  supply  chamber.  It 
receives  the  water  directly  from 
the  supply  pipe,  of  which  the 
lower  extremity  is  shown  at  k, 
and  delivers  it  into  the  outer 
part  of  the   upper   division  by 

partition  between  the  two  divisions.  This  outer  part^of'tli^'^nnp?^?'"^  ""■  '"  v^a 
the  guide-blade  chamber,  from  its  containing  Tr  gu'7e  bladl  oThioh  d.'r.Mf  ''  l'^ 
tangentially  into  the  wheel  chamber.     Imlediatdy  If'^'f^V^  ilj^ctd  ^nTo  tSi^The" 

chamber  the  water  is  received 
by  the  curved  radiating  passages 
of  the  wheel,  which  are  partly 
to  be  seen  inj?^.  1490  at  a  place 
where  both   the  cover    of    the 
wheel  chamber,  and  the  upper 
plate  of  the  wheel,  are  broken 
}   away  for  the  purpose  of  expos- 
^    ing  the  interior  to  view.     The 
water    on    reaching  the    inner 
ends  of  these  curved   passages, 
having  already  done  its  work, 
is  allowed  to  make  its  exit  by 
two  large  central  orifices  shown 
distinctly  on  the  figures   at  or 
adjacent  to  the  letters  l  l.  the 
one    leading  upwards   and   the 
other  downwards.     Close  jointa 
between  the  case  and  the  wheel 

of*«?^?i'ffl!n''^,r'  T  ''^'^  '"•^^'i  1491.  1492.  some  unimportant  modifications  are  mnde  for  the  purpose 
ctf^implifymg  the  drawings,  and  rendering  them  more  easily  understood  than  Jhey  wSSroTer! 


1490 


to  hinder  the  escape  of  water  otherwise  than  through  the  radiating  passages,  are  made 
by  means  of  two  annular  pieces  l,  l,  called  joint  rings,  fitting  to  the  central  orifices  of 
the  case,  and  capable  of  being  adjusted,  by  means  of  studs  and  nuts  so  as  to  come  close 
to  the  wheel,  without  impeding  its  motion  by  friction.  The  four  openings,  u,  h,  fig.  1490, 
through  which  the  water  flows  into  the  wheel  chambers,  each  situated  between  the  point 
or  edge  of  one  guide-blade  and  the  middle  of  the  next,  determine,  by  their  width,  the 
quantity  of  water  admitted,  and  consequently  the  power  of  the  wheel.  To  render  this 
power  capable  of  being  varied  at  pleasure,  the  guide  blades  are  made  moveable  round 
gudgeons  or  centres  near  their  points;  and  a  spindle  k,  worked  by  a  handle  in  any  con- 
venient position,  is  connected  with  the  guide-blades  by  means  of  links,  cranks,  «fee.  (see 
the  figures)  in  such  a  way  that  when  the  handle  is  moved,  the  four  entrance  orifices  are 
all  enlarged  or  contracted  alike.  The  gudgeons  of  the  guide-blades,  seen  in/<7.  1490  as 
small  circles  near  the  points,  are  sunk  in  sockets  in  the  floor  and  roof  of  the  guide-blade 
chamber,  and  so  they  do  not  in  any  way  obstruct  the  flow  of  the  water,  m  is  the  pivot 
box  of  the  upright  shaft,  and  is  constructed  with  peculiar  provisions  for  oiling  the  pivot, 
which,  by  reason  of  its  being  under  water,  does  not  admit  of  being  oiled  by  ordinary 
means,     n  is  a  hanging  bridge  which  forms  the  fixture  of  the  pivot 

This  vortex  is  calculated  for  50  horse-power,  with  a  fall  varying  from  90  to  100  feet 
On  account  of  the  great  height  of  the  fall,  the  machine  comes  to  be  of  very  small  dimen- 
sions; the  diameter  of  the  water  wheel  itself  being  only  about  15  inches,  and  the 
extreme  diameter  of  the  case  3  feet  9  inches.  The  speed  for  which  the  wheel  is  calcu- 
lated, in  accordance  with  its  diameter  and  the  velocity  of  the  water  entering  its  chamber, 
is  768  revolutions  per  minute. 

A  low  pressure  vortex  constructed  for  another  mill  near  Belfast  is  represented  in  vertical 

section  and  plan,  figa.  1491  and 
1492.  This  is  essentially  the  same 
in  principle  as  the  vortex  already 
described,  but  it  differs  in  the 
material  of  which  the  case  is  con- 
structed, and  in  the  manner  in 
which  the  water  is  led  to  the  guide 
blade  chamber.  In  this  the  case  is 
almost  entirely  composed  of  wood. 
The  water  flows  with  a  free  upper 
surface  w  w,  into  this  wooden  case, 
which  consists  chiefly  of  two  tanks, 
A  A,  and  B  B,  one  within  the  other. 
The  water-wheel  chamber,  and  the* 
guide-blade  chamber,  are  situated 
in  the  open  space  between  the 
bottom  of  the  outer  and  that  of 
the  inner  tank,  and  will  be  readily 
distinguished  by  reference  to  the 
figures.  The  water  of  the  head 
race,  having  been  led  all  round  the 
outer  tank  in  the  space  c  c,  flows  inward  over  its  edge,  and  passes  dow^nward  by  the 
space  D  D,  between  the  sides  of  the  two  tanks.  It  then  passes  through  the  guide-blade 
cnamber  and  the  water-wheel,  just  in  the  same  way  as  was  explained  in  respect  to  the 
high  pressure  vortex  already  described ;  and  in  this  one  likewise  it  makes  its  exit  by  two 

'  central  orifices,  the  one  discharging 

upward,  and  the  other  downward. 
The  part  of  the  water  which  passes 
downward  flows  away  at  once  to 
the  tail  race,  and  that  which  passes 
upward  into  the  space  e,  within 
the  innermost  tank,  finds  a  free 
escape  to  the  tail  race  through 
boxes  and  other  channels,  f  and  o, 
provided  for  that  purpose.  The 
wheel  is  completely  submerged 
under  the  surface  of  the  water  in 
the  tail  race,  which  is  represented 
at  its  ordinary  level  at  y  y,  fig.  1491, 
although  in  floods  it  may  rise  to  a 
much  greater  height  The  power 
of  the  wheel  is  regulated  in  a 
similar  way  to  that  already  de- 
scribed, in  reference  to  the  high 


1492 


^FTtjgViW^mnmn^Mttijmgi^ 


'-•i. 


916 


WAFERS. 


\ 


r   f  ' 


ii 


'III 


*  ■ 


pressure  vortex.  In  this  case,  however,  as  will  be  seen  by  the  figures,  the  guide-blades 
are  not  linked  together,  but  each  is  provided  with  a  hand  wheel  h,  by  which  motion  is 
communicated  to  itself  alone. 

The  foregoing  descriptions  are  suflScient  to  explain  the  principal  points  in  the  struc- 
tural arrangements  of  these  new  water  wheels. 

And  now  a  few  words  more  in  respect  to  their  principles  may  be  added.  In  these 
machines,  the  velocity  of  the  circumference  of  the  wheel  is  made  the  same  as  the  velocity 
of  the  entering  water,  and  thus  there  is  no  impact  between  the  water  and  the  wheel; 
butv  on  the  contrary,  the  water  enters  the  radiating  conduits  of  the  wheel  gently,  that  is 
to  say,  with  scarcely  any  motion  in  relation  to  their  mouths.  In  order  to  attain  the 
equalization  of  these  velocities,  it  is  necessary  that  the  circumference  of  the  wheel  should 
move  with  the  velocity  which  a  heavy  body  would  attain  in  falling  through  a  vertical 
space  equal  to  half  the  vertical  fall  of  the  water,  or,  in  other  words,  with  the  velocity 
due  to  half  the  fall ;  and  that  the  orifices  through  which  the  water  is  injected  into  the 
wheel  chamber  should  be  conjointly  of  such  an  area,  that,  when  all  the  water  re- 
quired IS  flowing  through  them,  it  also  may  have  the  velocity  due  to  half  the  fall. 

Thus  one  half  only  of  the  fall  is  employed  in  producing  velocity  in  the  water;  and, 
therefore,  the  other  half  still  remains,  acting  on  the  water  within  the  wheel  chamber  at 
the  circumference  of  the  wheel,  in  the  condition  of  fluid  pressure.  Now,  with  the 
velocity  already  assigned  to  the  wheel,  it  is  found  that  this  fluid  pressure  is  exactly  that 
which  is  requisite  to  overcome  the  centrifugal  force  of  the  water  in  the  wheel,  and  to 
^*°f  n  water  to  a  state  of  rest  at  its  exit,  the  mechanical  work  due  to  both  halves  of 
the  fall  being  transferred  to  the  wheel  during  the  combined  action  of  the  moving  water 
and  Uie  moving  wheel.  In  the  foregoing  statements,  the  effects  of  fluid  friction,  and  of 
some  other  modifying  influences,  are  for  simplicity  left  out  of  consideration. 

The  discussion  of  such  intricate  matters  would  be  unsuitable  for  the  present  article, 
the  object  of  which  was  to  give  a  full  and  clear  description  of  the  leading  features  of  an 
mven^on,  which  is  giving  great  satisfaction. 

w. 

WACKE,  is  a  massive  mineral,  intermediate  between  claystone  and  basalt.  It  is  of  a 
freenish-s:ray  color ;  vesicular  in  structure ;  dull,  opaque ;  streak  shining ;  soft,  easily 
frangible ;  spec.  grav.  2-55  to  2-9 ;  it  fuses  like  basalt. 

WADD,  is  the  provincial  name  of  plumbago  in  Cumberland ;  and  also  of  an  ore  ol 
manganese  in  Derbyshire,  which  consists  of  the  peroxyde  of  that  metal,  associated  with 
Tiearly  its  own  weight  of  oxyde  of  iron. 

WADDING  (Ouate,  Fr. ;  Watte,  Germ.),  is  the  spongy  web  which  serves  to  line 
ladies*  pelisses,  &c.  Ouate,  or  Wat,  was  the  name  originally  given  to  the  glossy  downy 
tufts  found  in  the  pods  of  the  plant  commonly  called  Jpocyn,  and  by  botanists  Jsclepia* 
Syriaca,  which  was  imported  from  Egypt  and  Asia  Minor  for  the  purpose  of  stuffing  cufh 
ions,  &c.  Wadding  is  now  made  with  a  lap  or  fleece  of  cotton  prepared  by  the  carding- 
engine  (see  Carding,  Cotton  Manufacture),  which  is  applied  to  tissue  paper  by  a  coat 
of  size,  made  by  boiling  the  cuttings  of  hare-skins,  and  adding  a  little  alum  to  the  selatin- 
ous  solution.  When  two  laps  are  glued  with  their  faces  together,  they  form  the  most 
downy  kind  of  wadding. 

WAFERS.    There  are  two  manners  of  manufacturing  wafers :  1,  with  wheat  flour 
and  water,  for  the  ordinary  kind;  and  2,  with  gelatine.     1.  A  certain  quantity  of  fine 
flour  IS  to  be  difl'used  through  pure  water,  and  so  mixed  as  to  leave  no  clotty  particles. 
This  thin  pap  is  then  colored  with  one  or  other  of  the  matters  to  be  particularly 
described  under  the  second  head;  and  which  are,  vermilion,  sulphate  of  indigo,  and 
gamboge.    The  pap  is  not  allowed  to  ferment,  but  must  be  employed  immediately  after  it 
J  mixed.    For  this  purpose  a  tool  is  employed,  consisting  of  two  plates  of  iron,  which 
come  together  like  pincers  or  a  pair  of  tongs,  leaving  a  certain  small  definite  space 
betwixt  them.     These  plates  are  first  slightly  heated,  greased  with  butter,  filled  with 
the  pap,  closed,  and  then  exposed  for  a  short  time  to  the  heat  of  a  charcoal  fire     The 
iron  plates  being  allowed  to  cool,  on  opening  them,  the  thin  cake  appeai-s  dry,  solid 
brittle,  and  about  as  thick  as  a  playing-card.     By  means  of  annular  punches  of  different 
sizes,  with  sharp  edges,  the  cake  is  cut  into  wafers.     2.  The  transparent  wafers  are 
made  as  follows: — 

Dissolve  fine  glue,  or  isinglass,  in  such  a  quantity  of  water  that  the  solution,  when 
cold,  may  be  consistent  Let  it  be  poured  hot  upon  a  plate  of  mirror  glass  (previously 
warmed  with  steam,  and  slightly  greased),  which  is  fitted  in  a  metallic  frame  with  edgw 
just  as  high  as  the  wafers  should  be  thick.  A  second  plate  of  glass,  heated  and 
greased,  is  laid  on  the  surface,  so  as  to  touch  every  point  of  the  gelatine,  resting  on  the 
edges  of  the  frame.    By  this  pressure,  the  thin  cake  of  gelatine  is  made  perfectly 


WASH. 


917 


the  two  plates  of  glass  get  cold,  the  gelatine  becomes  solid,  and  may  easily  be  removed 
It  is  then  cut  with  proper  punches  into  discs  of  different  sizes. 

The  coloring  matters  ought  not  to  be  of  an  insalubrious  kind. 

For  red  wafers,  carmine  is  well  adapted,  when  they  are  not  to  be  transparent;  but 
this  color  is  dear,  and  can  be  used  only  for  the  finer  kinds.  Instead  of  it,  a  decoction 
of  brazil  wood,  brightened  with  a  little  alum,  may  be  employed. 

For  yellow,  an  infusion  of  saffron  or  turmeric  has  been  prescribed;  but  a  decoction 
of  weld,  fustic,  or  Persian  berries  might  be  used. 

Sulphate  of  indigo,  partially  saturated  with  potash,  is  used  for  the  blue  wafers;  and 
this  mixed  with  yellow,  for  the  greens.  Some  recommend  the  sulphate  to  be  nearly 
neutralized  with  chalk,  and  to  treat  the  liquor  with  alcohol,  in  order  to  obtain  the  be^ 
blue  dye  for  wafers. 

Common  wafers  are,  however,  colored  with  the  substances  mentioned  at  the  begin- 
ning of  the  article ;  and  for  the  cheaper  kinds,  red  lead  is  used  instead  of  vermillion, 
and  turmeric  instead  of  gamboge. 

Three  new  methods  of  manufacturing  wafers  were  made  the  subject  of  a  patent  bv 
Peter  Armand  Le  Comte  de  Fontainemoreau,  in  April,  1860;  the  chief  feature  of  which 
is  a  layer  of  metal  foil.  In  the  first  of  the  three  forms  described,  the  metal  slip  or  band 
is  to  be  coated  with  the  ordinary  farinaceous  paste  used  for  making  wafers,  for  which 
purpose  the  slip  is  laid  on  one  of  the  jaws  of  the  ordinary  iron  mould,  then  a  spoonful  of 
paste  is  poured  on  it,  the  mould  is  shut,  and  the  paste  baked  as  usual.  The  metal  band 
18  lastly  punched  into  wafers,  either  plain  or  ornamental. 

The  second  method  is  to  stick  these  slips  to  paper  with  paste,  then  to  dry  and  punch 
them  out 

By  the  third  plan,  strips  of  gummed  paper  are  affixed  to  the  slips,  and  a  resinous 
cement  is  put  on  the  other  side.  The  first  two  methods  require  moistening,  the  third 
heating.     This  contrivance  is  susceptible  of  much  variety  of  decoration. 

WALNUT  HUSKS,  or  PEELS  {Brout  des  noix,  Fr.);  are  much  employed  by  the 
French  dyers  for  rooting  or  giving  dun  colors. 

WARES  (HARD).  Birmingham  has  long  been  connected  with  the  manufacture  of 
hardware  of  every  kind,  to  such  a  degree  that  the  name  of  the  town  has  often  become 
associated  with  these  articles.  Some  departments  of  the  trade  are  likewise  vigorously 
pushed  at  Wolverhampton,  Walsall,  and  SheflSeld;  but  Birmingham  may  be  legiti- 
mately considered  as  the  metropolis  for  hardware  generally;  and  the  enormous  exten- 
sion of  its  trade,  attributable  in  a  large  measure  to  these  manufactures,  indicates  the 
momentous  results  to  which  the  production  in  quantities  of  the  most  trivial  objects  may 
give  rise.  In  40  years  the  population  of  Birmingham  has  increased  by  nearly  160  per 
cent ;  and  what  is  highly  instructive  and  remarkable,  is  the  fact  that  in  proportion  to 
the  increase  of  production  has  been  the  decrease  in  price,  until  there  has  been  a  reduc- 
tion in  the  same  period  of  about  62  per  cent,  and  in  some  articles  to  86  per  cent  The 
exports  likewise  immensely  increased  in  the  same  time;  at  its  commencement  they 
slightly  exceeded  6,800  tons  annually;  in  1849  the  exports  amounted  to  23,421  tons,  the 
value  of  which  has  been  estimated  at  about  £2,201,316  sterling.  This  relates  nearly  to 
the  iron  manufactures:  of  the  brass  and  copper  manufactures  were  exported  in  1849  to 
the  value  of  £1,875,865;  and  it  deserves  notice  that  the  greatest  proportion  of  these 
manufactures  absorbed  by  any  country  is  that  annually  imported  by  Hindostan,  a  coun- 
try whose  early  reputation  in  metal  manufactures  is  a  subject  of  familiar  knowledge. 

The  system  of  the  manufacture  of  hardware  in  Birmingham  is  peculiar,  and  presents 
a  striking  contrast  to  that  adopted  in  Manchester  and  other  large  manufacturing  places: 
the  operatives  are  themselves  the  manufacturers.  Hiring  a  workshop  in  which  steam- 
power  is  laid  on,  and  which  is  specially  fitted  up  by  the  owner  of  the  building,  in  which 
many  such  workshops  are  contained,  the  artizan  plies  his  peculiar  trade,  manufactures 
his  articles,  carries  them  home  to  the  merchant,  and  receives  the  weekly  payment  for 
them,  which  enables  him  to  procure  fresh  materials,  and  proceed  in  the  ensuing  week 
with  his  regular  labors*  A  very  lai^e  proportion  of  hardware  is  thus  manufactured. 
But  this  system  is  not  universal,  and  regularly  organized  factories  employing  a  large 
nuniber  of  workpeople,  and  possessing  all  the  distinguishing  features  of  a  great  pro- 
ducing establishment,  exist  and  are  in  active  operation. 

WARP  {Chaine,  Fr.;  Kette,  Anschweif,  Zettel,  Germ.);  is  the  name  of  the  longitudi- 
nal threads  or  yarns,  whether  of  cotton,  linen,  silk,  or  wool,  which  being  decusated 
at  right  angles  by  the  woof  or  weft  threads  form  a  piece  of  cloth.  The  warp  yams 
are  parallel,  and  continuous  from  end  to  end  of  the  web.  See  Weaving,  for  a  descrip- 
tion of  the  ujarping-miil. 

WASH,  is  the  fermented  wort  of  the  distiller. 

WASHING.     See  Bleaching  and  Scouring. 

WATERING    OF   STUFFS   {Moirage,    Fr.;)    is    a   process   to   which    silk    and 


1 


;i!l- 


I 


:    t 


918 


WATERS,  MINERAL. 


folWrfrit-^^ftXr.uTtV''  *^Pf'""  P'~^°f  "■••  Charles  Townaend  „ 

two  different  solutions  in  suceefsion  th7nnr.f  ^.  •  i  ■  }'  ^1,  ^^^  "'^*  eometimea 
dissolved  in  9  ffallonrof  born?wafVr  Z  ^.K  '  n'  \^  P°"".^«  «^  «"^P^«t«  ^^  "°«. 
in  solution,     fh     combinaUo^^^  ''  ^'''  f^^^"  "^'^^"''^  ^^g"'"  a°<l  «oap 

application.     The^:gtorr,rLrL™I?orrd^  water-proofing 

and  2I  feet  wide;  c:„rninJ'.i:urro7«l  ootfTfe1ZL'ro7lt"Vh't  '°?^' 
13  raost  eonveiiienlly  performed  by  three  men  •  two  to  hoW  tL  1  a  ??'  '''■PP'"* 

ho  d  the  head  out  oM.e  eolution  when  the  bodytimmei^ed     feZ  il"".'  t'^  ^ 

M  possible  o/t  of  the  wo„°  After  thf,  H?.  1  '^*°  T  ^."^'^  "•"  "l"'''  ™  ■»<"«'• 
nearly  dry  which  will  h.  ;„  1    I  o  u  '''f  P.  '*  «"o«'«'i  to  stand  till  its  ooat  is 

of  soVin'  tl  st,TLn„  r  as  U  was  d"';L^"''i  "^f."  "  !'  *"  "",  ^'P^'^  •"  «"«  »'"«<>» 
dipping  is  eompleted,  T  sh^'e^Uy"  to  K^t^V  „  r^'^^"^^^^  ^  ^'""  '"'*  '"' 
each  fibre  of  the  fleece  willXSfhe  oiol.Cof  t  Jir  Pf'^''/''^^  P"'"™'* 

will  be  keptdrv  the  an^»l  E..lT„  .  i^  r^  .  urP'"',''S  -"ater,  and  thus  the  wool 
factnring  purples!  ^  ""'  eomfortable,  and  the  wool  improved  for  manu- 

emX"l"a.t;i:':'rplZLost''r,°'  t' "'  t'^  s*''"--'  """^  '-v  ^ 

in    conjunction    with    tKrorr«lif''"n  '"!  "P,!"'"«  'T'*"'  ■""?  ''«  '"P'-'W 

The  at4e  invention  is  patented  f„7he„amtn?^l/J'".''*''>-  °'  T'^'''  »<«**«• 
l»51.-Neu,lm;  Journal,  ^lui  °    Alexander  Me.n.  and  enrolled  Jun«i 

sitK^e  rt"lt'tratJ^M±t"^al^^^^^^^  '^^T  ^  .^T" 

Analyses.     The  symbol  N  iUnnfl.  k'\  ^®^®^^  °[  ^^ermany,  according  to  the  best 


OQ 
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p  <»  ^~>®  -,  ^ "^ "*> "^ '*» <^ 


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Calcareoui,   Cbaly- 
nearly  pure,   beate. 


Saline. 


Solphu- 
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p  P 

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h^  ^^  *^  "* 
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a.  t=  e.      o  2.  c 

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to  to  o  o 


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CO  I— •  i-d  CO  k.<  rv> 

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928 


WATERS. 


Mineral  waters  may,  m  most  cases,  be  artificially  prepared,  by  the  skilful  application 
of  the  knowledge  derived  from  analysis,  with  such  precision  as  to  imitate  yery  closely 
the  native  springs.  When  the  various  earthy  or  metallic  constituents  are  held  in  solu- 
tion by  carbonic  acid,  or  sulphuretted  hydrogen,  they  should  be  placed  along  with 
their  due  proportions  of  water,  in  the  receiver  of  the  aerating  machine  (see  Soda  WatebI 
and  then  the  proper  quantity  of  gas  should  be  injected  into  the  water.  Sufficient  agi- 
tation will  be  given  by  the  action  of  the  forcing  pump  to  promote  their  solution 

P^a^r^Yi^  u'j  'TJ^^Z''''^  S'"*''^  ^  ^^'^^  ofTenhury,  Worcestershire,  the 
Froperty  of  8.  Holmes  Godson,  Esq.  By  methods  somewhat  similar  to  those  described 
in  my  paper  on  the  "Analysis  of  the  Moira  Brine  Spring."  which  the  Royal  Society 
honored  with  a  place  in  their  Transactions  for  1834,  part  ii.,  I  obtained  the  foUowing 
results  from  one  gallon— Y0,0'>0  water-grain  measuresLl  gallon :— 


1.  Chlorsodium  (muriate  of  soda) 

2.  Chlorcalcium  (muriate  of  lime)     - 

3.  Chlormagnesium  (muriate  of  magnesia) 

4.  Sulphate  of  lime    -  .       ^ .       ' 
6.  Protocarbonate  of  iron 

6.  Bromide  of  sodium  (bromsodium) 


graini. 

1801-4 

425-6 

61-3 

6-0 

1-6 

16-2 


Total  saline  contents— .1802-0 
Specific  gravity  of  the  water  at  60°  F.—1-0208 
Taste,  bitter  saline,  but  not  unpleasantly  so. 

..f^'"  ^t^^fu^u  ^^^"^  ^"""^  P"'^^*^  ^""^  '^'^  medicinal  virtues  as  a  deobstruent  In 
reference  to  the  bromine  constituent,  it  is  doubly  richer  than  the  Moira  spring  water, 
-olln  ^^^.^^^^^^J'^'n  of  the  presence  and  approximate  proportion  of  bromine  in  such  a 
saline  water  is  attended  with  no  difficulty.  Having  concentrated  a  considerable  quan- 
«lZ.f  ir  ^7  ev*P<>ration  to  so  such  a  pitch  as  to  separate  the  greater  part  of  the  readily 
crystallizable  muriate  of  soda,  add  to  the  filtered  mother-water  a  small  portion  of  pretty 
strong  chlorine- water.    The  bright  golden  yellow  color  immediately  produced  indicates 

in^  th.TnHr''  '  •"1!""^??/''^"?.*^  «^'^  ^^  hydrobromic  acid.    Ether  being  poured 
into  the  bottle  partially  filled  with  the  saline  solution,  and  agitated  therewith  seizes 

il  nf  .T'°^'  *°i  "*?  v^P"*'*  "'*'*  ^^^^  ^*^  «°^  ^««^  i'l  a  rich  crimson  solution  on  the 
ivLi  ^^;j,^««?^«red  hquor.     Care  must  be  taken  that  chlorine  has  not  been  used  in 

tho!S.  ^^^^""^^'^  ^^^  ""T^  Pr«<^^««  wo»W  be  vitiated,  which  consist,  first,  in  decanting 
of  nof/Jh?r  *'7P<>"'1<3'?«<^  saturating  it  with  pure  potash  lye,  so^as  to  form  bromidi 
•IS  wifh  ^;  •  T^'«  «*>l"t»r  ^^^°^  evaporated,  and  gently  ignited,  is  to  be  supersatur- 
«^wl  hi  i  ^K^*^i  ^^""TT  precipitated  with  nitratS  of  silver,  and  the  brown 
r^Z^T^tl  T  K^'^'-  filtered,  dried,  and  gently  ignited.  100  parts  of  that  bromide 
IS  f  K  ^  of  bromine  In  Mr.  Godson's  mineral  spring,  there  are  very  nearly  12* 
from  the  warr'""^  ^''*  ^  '  ""^  "^  *^'''^^'"'  "^^^^^  eitracUng  on  the  large^cia! 
ra^t.^^?^'"'-!!^'''^  ^^^  ^^^"^  stripped  of  its  bromine  by  potash  lye,  may  be  nearly  all 
Tfehlnr^^Jm  ♦r°P'^P'''T/^r'^'^  ^'  **^  ^^  repeatedfy  applied  to  fresh  quantities 
t.t^if  ?     rnother-water.    If  the  bromide  of  potaLium  be  mixed  with  one-tliird  of  its 

Sio  .2Tf'?7^^rt.^^??'''  ^°^  *^"  ™^'^^"'-«  ^i«ti"«^  ^ith  its  own  weight  of  sul- 
?i.;l' fl"^'  1'^-''^."^  ""'^^  ^^^i'^  "^^'S^^  ^^  ^ater,  from  a  retort  whose  beak  dips  into  a 

maX  ent?rl"  ."^'"5''';' i^J  ^^"T^^^  ^^''^  ««™^«  ^^^^  f«"«  ^o  the  bottom,  and 
hme)  ^  de-hydrated  by  re-distillation  over-chlorcalcium  (calcined  muriate  of 

.hwffiflJiT'ri!  °^*y  »1«<>  be  extracted,  and  that  very  economically,  by  distilling  the 
Thpfrol^^  IT-T^''  ^^  *^'  'P""S  ^^^^  ^^'  mixture  of  manganese  an^d  oil  of  vftrbL 
Id  thThv  I  ^^  passes  over  may  be  afterwards  purified  by  washing  with  water, 
and  then  by  the  process  above  described,  with  potash,  nitric  acid  Ac  -Dr  Ureii, 
PharmaceuticalJournal,  1848,  vol.  viii.  Na  4. 

Nanheim   a  spa  recently  discovered'on  the  south-eastern  declivity  of  Johannisbenr 
tTlr    r  ^ST  Frankfort-on-the-Mayne  by  railway,  displays^  the  phenomen^ 

l^h  ofrbnni^'riiit^'  °'  '±T^''t^'  *  ^^1"™°  ^^  white  Lm  Lb^bling  ur2  "r  3  feet! 
with  carbonic  acid  gas,  670  feet  above  the  level  of  the  sea.    It  is  an  Artesian  well- 

murilte  of  «od/Jr'^°  gravity  of  1-007  at  72-50  Fahr.     Ite  chief  constituentrare 

rtrb:omid:':h:fur'  """^^  ^^  p^^^^^'  ^^--^  -^  ^-^^  ^^«  ^-^  ^^^-^-t. 

wifh^linL?I'''f  ^°°^^^^'"&  ^'i  J.6  «^  256  grains  of  sea  salt,  8}  of  muriate  of  magnesia, 
b^fh  !nP    f      of  magnesia  and  lime  in  considerable  quantity,  and  of  spec,  gravel -01? 

L  fn  thri'Jr/.'r  .^?^.,^^«^r' -^  "'  Oeynhausen,  Sear  Miiden  upon^he  We  er     I 
18  in  the  immediate  vicinity  of  an  immense  brine  spring  which  throws  up  64  cubic  feet 


mm 


WAX. 


929 


of  salt  water  containing  416  grains  in  10.000  of  saline  matter  at  a  temperature  of  96° 
Fahr.  This  spring  contains  also  some  bromine,  and  throws  out  jets  of  carbonic  acid  gas. 
This  well  has  the  prodigious  depth  of  1994  feet  below  the  level  of  the  sea ;  and  its  mouth 
is  217  feet  above  it*  Here  there  have  been  67  baths  of  different  classes  established.  The 
whole  has  been  well  investigated  and  placed  under  the  superintendence  of  Dr.  Bischofl^ 
Professor  of  Chemistry  in  Bonn. 

WAX  (Cire,  Fr. ;  Wachs,  Germ.),  is  the  substance  which  forms  the  cells  of  bees. 
It  was  long  supposed  to  be  derived  from  the  pollen  of  plants,  swallowed  by  these 
insects,  and  merely  voided  under  this  new  form ;  but  it  has  been  proved  by  the  experi- 
ments, first  of  Mr.  Hunter,  and  more  especially  of  M.  Huber,  to  be  the  peculiar 
secretion  of  a  certain  organ,  which  forms  a  part  of  the  small  sacs,  situated  on  the  sides 
of  the  median  line  of  the  abdomen  of  the  bee.  On  raising  the  lower  segments  of  the 
abdomen,  these  sacs  may  be  observed,  as  also  scales  or  spangles  of  wax,  arranged  in 
pairs  upon  each  segment.  There  are  none,  however,  under  the  rings  of  the  males  and 
the  queen.  Each  individual  has  only  eight  wax  sacs,  or  pouches;  for  the  first  and  the 
last  ring  are  not  provided  with  them.  M.  Huber  satisfied  himself  by  precise  experi- 
ments that  bees,  though  fed  with  honey,  or  sugar  alone,  produced  nevertheless  a  very 
considerable  quantity  of  wax ;  thus  proving  that  they  were  not  mere  collectors  of  this 
substance  from  the  vegetable  kingdom.  The  pollen  of  plants  serves  for  the  nourishment 
of  the  larvae. 

But  wax  exists  also  as  a  vegetable  product,  and  may,  in  this  point  of  view,  be 
regarded  as  a  concrete  fixed  oil.  It  forms  a  part  of  the  green  fecula  of  many  plants, 
particularly  of  the  cabbage ;  it  may  be  extracted  from  the  pollen  of  most  flowers ;  as 
also  from  the  skins  of  plums,  and  many  stone  fruits.  It  constitutes  a  varnish  upon  the 
upper  surface  of  the  leaves  of  many  trees,  and  it  has  been  observed  in  the  juice  of  the 
cow-tree.  The  berries  of  the  Mxjrica  angustifoliay  latifoliay  as  well  as  the  ceriferay  afford 
abundance  of  wax. 

Bees*  wax,  as  obtained  by  washing  and  melting  the  comb,  is  yellow.  It  has  a  peculiar 
smell,  resembling  honey,  and  derived  from  it,  for  the  cells  in  which  no  honey  has  been  de- 
posited, yield  a  scentless  white  wax.  Wax  is  freed  from  its  impurities,  and  bleached,  by 
melting  it  with  hot  water  or  steam,  in  a  tinned  copper  or  wooden  vessel,  letting  it 
settle,  running  oflf  the  clear  supernatant  oily-looking  liquid  into  an  oblong  trough  with 
a  line  of  holes  in  its  bottom,  so  as  to  distribute  it  upon  horizontal  wooden  cylinders^ 
made  to  revolve  half  immersed  in  cold  water,  and  then  exposing  the  thin  ribands  of 
films  thus  obtained  to  the  blanching  action  of  air,  light,  and  moisture.  For  this  pur- 
pose, the  ribands  are  laid  upon  long  webs  of  canvass  stretched  horizontally  between 
standards,  two  feet  above  the  surface  of  a  sheltered  field,  having  a  free  exposure  to  the 
sunbeams.  H6re  they  are  frequently  turned  over,  then  covered  by  nets  to  prevent  their 
being  blown  away  by  winds,  and  watered  from  time  to  time,  like  linen  upon  the  grass 
field  in  the  oU  method  of  bleaching.  Whenever  the  color  of  the  wax  seems  station- 
ary, it  is  collected,  remelted,  and  thrown  again  into  ribands  upon  the  wet  cylinder,  in 
order  to  expose  new  surfaces  to  the  blanching  operation.  By  several  repetitions  of 
these  processes,  if  the  weather  proves  favorable,  the  wax  eventually  loses  its  yellow 
tint  entirely,  and  becomes  fit  for  forming  white  candles.  If  it  be  finished  under  rain,  it 
will  become  gray  on  keeping,  and  also  lose  in  weight. 

In  France,  where  the  purification  of  wax  isaconsiderableobjectof  manufacture,  about 
four  ounces  of  cream  of  tartar,  or  alum,  are  added  to  the  water  in  the  first  melting- 
copper,  and  the  solution  is  incorporated  with  the  wax  by  diligent  manipulation.  The 
whole  is  left  at  rest  for  some  time,  and  then  the  supernatant  wax  is  run  ofi"  into  a 
settling  cistern,  whence  it  is  discharged  by  a  stopcock  or  tap,  over  the  wooden  cylinder 
revolving  at  the  surface  of  a  large  water-cistern,  kept  cool  by  passing  a  stream  con- 
tinually through  it. 

The  bleached  wax  is  finally  melted,  strained  through  silk  sieves,  and  then  run  into 
circular  cavities  in  a  moistened  table,  to  be  cast  or  moulded  into  thin  disc  pieces,  weigh- 
ing from  two  to  three  ounces  each,  and  three  or  four  inches  in  diameter. 

Neither  chlorine,  nor  even  the  chlorides  of  lime  and  alkalis,  can  be  employed  with  any 
advantage  to  bleach  wax,  because  they  render  it  brittle,  and  impair  its  burning  quality. 

Wax  purified,  as  above,  is  white  and  translucent  in  thin  segments ;  it  has  neither  taste 
nor  smell ;  it  has  a  specific  gravity  of  from  0-960  to  0-966 ;  it  does  not  liquefy  till  it  be 
heated  to  154|°  F. ;  but  it  softens  at  86°,  becoming  so  plastic,  that  it  may  be  moulded  by 
the  hand  into  any  form.    At  32P  it  is  hard  and  brittle. 

It  is  not  a  simple  substance,  but  consists  of  two  species  of  wax,  which  may  be  easily 
separated  by  boiling  alcohol.  The  resulting  solution  deposites,  on  cooling,  the  waxy 
body  called  cerine.  The  undissolved  wax,  being  once  and  again  treated  with  boiling 
alcohol,  finally  affords  from  70  to  90  per  cent.  V  its  weight  of  cerine.  The  insoluble 
residuum  is  the  myricine  of  Dr.  John,  so  called  because  it  exists  in  a  much  larger  pro- 


-■■^■T"Mj'.#lk-^Ft-.--jO>.-^s^^.,   ,_^ 


I 


930 


WEAVING. 


I 


^s,tl%:x^^i^r'tnTt,'L  a"s,s»"i  ''^f '  '*»» "«"'  ""-s  of  .h. 

undergoes.    &e  th«e  two  anicl«         '  """^  ""''™'  """'-Position,  which  cerin« 

.inrwVi'ch  d^Sr  .rer^r!  a^nilVrAw'  K  S  '^•"'"'h  •"•  »"  «'  '"'>«"- 
with  mutton  suet      This  fr«nH  mo,,  i      r  ^aji"  substance ;  and  more  frequently 

.hereby  .tfcd,  it  Ju^wfTete^d  XTc^  whSi^'l'^ir^ Ir '"  ^"'^^  ""' 

"  WAV '\u vi'LT^'^^'""'-  «>'-•  f™"foretin!3«r'-'  *"'"'"''''  '^'  '""'■     ""'"• 

texture,  .  conchoidal  (r^ciu^Xy>tT.mt'  l^TTZtV''  T"'  "^  '  !■""."  "* 
a  mortar.  Its  specific  gravity  varierS'u'snnl' «2«  S^'  T  ^  P"'«"«<i  in 
of  it  in  Moldavia,  which  give  a  to*erab  eZht      ?.  ll  .'  ,1,^  r"*"'".  """^  ''""  """J^ 

near  Slanik,  beneath  a  bed  of  bitumi^nf.  .w  1  """  "  "'^'^'  o*^  ""  Carpathians 
weight.  Liyers  of  brown  amb^r  Z  f«„nt tflf'''  '"•  T^T  °f  '^'""  *"  '"  100  pounds 
Tariegated  sandstone,  Zk  saTand  beds  of  c™!  ,r  ""^J^bo^ho'?''-  It  is  associated  with 
Something  similar  has  been  dkiovered  in  ,  f^  ^  ^^,"'tt^  "\  " ,"  analogous  to  hatchetivt. 
faChon,s  if  neath  *>^'l«^l^e'!'T:^::^uTci:S^^^^^^^^^  ^ 

will  furnish  the  qHantity  required  foV  tl^^e  Ln  j^h  ^  .V  "'  ""J""!  therefore  be  taken  as 
sixth  of  that  number  of  bobbins  is  usuall  mounL  I  '"'•'"^t'^  P''*^^  ^^  *=^«'^-  ^ne 
loosely  in  a  horizontal  dTectJon  u^t^^rrs^^^^^^^^  ""'' 5^^?  ««' 

that  they  may  revolve,  and  give  off  the  yarn  fr^elv  Th^^  '  '"  •Z'^"*'^  ^'*°'^'  ^*» 
and  causes  the  reel  b  Jo  revo^  by  tur:iir?o::rdtith\l^  ^aXhe  ^Jef 'c,^^f itl't'h'e' 

endless   rope    or  band   d. 
The    bobbins    filled    with 
yarn    are    placed    in    the 
frame  e.  There  is  a  sliding 
piece  at  f,  called  the  heck 
box,  which  rises  and  falls 
by  the  coiling  and  uncoil- 
ing  of  the  cord  g,  round 
the  central  shaft  of  the  reel 
H.     By  this  simple  contri* 
Vance,  the  band  of  warp- 
yarns    is    wound   spirally, 
from  top  to  bottom,  upon 
the  reel,     i,  i,  i,  are  wood- 
en pins  which  separate  the 
different     bands.        Most 
warping    mills    are    of  a 
prismatic      form ;     having 
twelve,  eighteen,  or  more 
sides.      The  reel  is  com- 

monly  about    six   feet    in 

m  height,  so  as  to  serve  for  measurin*'  Pxartlr  ,in««    •»         <^?a™eter,   and   seven   feet 
the  warp.     All  the  threadrfrmn   f^f  /  ^    ^^.  **^  periphery  the  total  length  of 

of  a  series  of  lely.roHshe^^  ^^^^^f  the  heck  r,  which  consists 

•  part  of  each,  to  receive  and  S'eoTe  thread  The'hT'iJ  '  T"^}  ^'''  ^'  '^^  "PP" 
either  of  which  may  be  lifted  by  a  small  handlp  hL  km  ^'^u^-^  ^"'°  ^^^  P^'^^' 
alternately.  Hence;  when  one  of  them t  raised  a  mtr«v''  *^-'  P''  f"  P^*^^^ 
the  two  bands  of  the  warp  •  but  when^h!  nfl  ■    \^  vacuity  is  formed  between 

this  way,  the  lease  is  Troduced  aT  each  end  of  the  warn  'and'-r-'"''^  ^'  'Tl''"^'     ^"^ 

ri:^:ShiSe.s:  x^^iS^V^??^^^^ 

and  from  left  to  right,  tiU^  ^^2^ J^  Zfj^^^S:^^  ^ 


WEAVING,  BY  HAND. 


931 


breadth  that  is  wanted ;  the  warper's  principal  care  being  to  tie  immediately  every  thread 
as  it  breaks,  otherwise  deficiencies  would  be  occasioned  in  the  chain,  injurious  to  the  ap- 
pearance of  the  web,  or  productive  of  much  annoyance  to  the  weaver. 

The  simplest  and  probably  the  most  ancient  of  looms,  now  to  be  seen  in  action,  i« 
that  of  the  Hindoo  tanty,  shown  in  Jig.  1494.    It  consists  of  two  bamboo  rollers;  one  for 

the  warp,  and  another  for  the 
woven  cloth  ;  with  a  pair  of 
heddles,  for  parting  the  warp, 
to  permit  the  weft  to  be  drawn 
across  between  its  upper  and 
under  threads.  The  shuttle  is 
a  slender  rod,  like  a  large  net- 
ting needle,  rather  longer  than 
the  web  is  broad,  and  is  made 
use  of  as  a  batten  or  lay,  to 
strike  home  or  tondense  each 
successive  thread  of  weft, 
against  the  closed  fabric.  The 
Hindoo  carries  this  simple  im- 
plement, with  his  water  pitcher, 
rice  pot,  and  hooka,  to  the  foot 
of  any  tree  which  can  afford  him 
a  comfortable  shade ;  he  there 
digs  a  large  hole,  to  receive  his 
legs,  along  with  the  treddles  or  lower  part  of  the  harness ;  he  next  extends  his  warp, 
by  fastening  his  two  bamboo  rollers,  at  a  proper  distance  from  each  other,  with  pins, 
into  the  sward ;  he  attaches  the  heddles  to  a  convenient  branch  of  the  tree  overhead ; 
inserts  his  great  toes  into  two  loops  under  the  gear,  to  serve  him  for  treddles ;  lastly,  he 
sheds  the  warp,  draws  through  the  weft,  and  beats  it  close  up  to  the  web  with  his  rodshullle 

or  batten.  .  •  .  j  r  i 

The  European  loom  is  represented  in  its  plainest  state,  as  it  has  existed  for  several 
centuries,  in  fig.  1495.  a  is  the  warp-beam,  round  which  the  chain  has  been  wound  ;  b 
represents  the  flat  rods,  usually  three  in  number,  which  pass  across  between  its  threads, 
to  preserve  the  lease,  or  the  plane  of  decussation  for  the  weft  ;  c  shows  the  heddles  or 
healds,  consisting  of  twines  looped  in  the  middle,  through  which  loops  the  warp  yarns 
are  drawn  one  half  through  the  front  heddle,  and  the  other  through  the  back  one ;  by 


1495 


moving  which,  the  decussation  is  readily 
effected.  The  yarns  then  pass  through 
the  dents  of  the  beed  under  d,  which 
is  set  in  a  moveable  swing-frame  e, 
called  the  lathe,  lay,  and  also  batten, 
because  it  beats  home  the  weft  to  the 
web.  The  lay  is  freely  suspended  to  a 
cross-bar  f,  attached  by  rulers,  called 
the  swords,  to  the  top  of  the  lateral 
standards  of  the  loom,  so  as  to  oscillate 
upon  it.  The  weaver,  sitting  on  the 
bench  g,  presses  down  one  of  the  tred- 
dles at  H,  with  one  of  his  feet,  whereby 
he  raises  the  corresponding  heddle, 
but  sinks  the  alternate  one ;  thus  sheds 
the  warp,  by  lifting  and  depressing  each 
alternate  thread,  through  a  little  space, 
and  opens  a  pathway  or  race-course 
for  the  shuttle  to  traverse  the  middle  of  the  warp,  upon  its  two  friction  rollers  m,  m.  For 
this  purpose,  he  lays  hold  of  the  picking-peg  in  his  right  hand,  and,  with  a  smart  jerk  of 
his  wrist,  drives  the  fly-shuttle  swiftly  from  one  side  of  the  loom  to  the  other,  between 
the  shed  warp  yarns.  The  shoot  of  weft  being  thereby  left  behind  from  the  shuttle  pirn 
or  cop,  the  weaver  brings  home,  by  pulling,  the  lay  with  its  reed  towards  him  by  his  left 
hand,  with  such  force  as  the  closeness  of  the  texture  requires.  The  web,  as  thus  woven, 
is  wound  up  by  turning  round  the  cloth  beam  i,  furnished  with  a  ratchet-wheel,  which 
takes  into  a  holding  tooth.  The  plan  of  throwing  the  shuttle  by  the  picking-peg  and  cord, 
is  a  great  improvement  upon  the  old  way  of  throwing  it  by  hand.  It  was  contrived  exactly 
a  century  ago,  by  John  Kay,  of  Bury  in  Lancashire,  but  then  resident  in  Colchester,  and 
was  called  the  fly-shuttle,  from  its  speed,  as  it  enabled  the  weaver  to  make  double  the 
quantity  of  narrow  cloth,  and  much  more  hroadcloth,  in  the  same  time. 
The  cloth  is  kept  distended,  during  the  operation  of  weaving,  by  means  of  two  piecet 


932 


WEAVING,  BY  POWER. 


The  gr  ater  part  of  plain  weaving,  and  much  even  of  the  figured,  is  now  performed  b. 
^^^°  1496 


WEAVING,  BY  POWER. 


933 


the  power  loom,  caUed  mifier  mScanique  d  tisser,  in  Frencli      F,v    ^aq^ 
cast-iron  power  loom  of  Sharp  and  Roberts        a   a'   «?:  I^l  1496,  repreBenls  the 
standards,  on  the  front  of  the  loom,     d,  is  thi  ^rel't  «;r?  nf     %*^'*  side  uprights,  or 
two  sides  together.    .,  is  the  front  cross-te^i^lt  T^^rorl^teTilZt 


ends  are  bolted  to  the  opposite  standards  a,  a',  so  as  to  bind  the  framework  most  firmly 
together,     g',  ig  the  breast  beam,  of  wood,  nearly  square ;  its  upper  surface  is  sloped  a 
little  towards  the  front,  and  its  edge  rounded  ofl^",  for  the  web  to  slide  smoothly  over  it,  in 
its  progress  to  the  cloth  beam.     The  beam  is  supported  at  its  end  upon  brackets,  and  is 
secured  by  the  bolts  g',  g'.     H,  is  the  cloth  beam,  a  wooden  cylinder,  mounted  with 
iron  gudgeons  at  its  ends,  that  on  the  right  hand  being  prolonged  to  carry  the  toothed 
winding  wheel  h'.    fc',  is  a  pinion  in  gear  with  h'.     h",  is  a  ratchet  wheel,  mounted 
upon  the  same  shaft  h"',  as  the  pinion  h'.     h',  is  the  click  of  the  ratchet  wheel  h".     A'", 
is  a  long  bolt  fixed  to  the  frame,  serving  as  a  shaft  to  the  ratchet  wheel  h",  and  the 
pinion  h'.    i,  is  the  front  heddle-leaf,  and  i',  the  back  one.     J,  J,  j',  j',  jacks  or  pulleys 
and  straps,  for  raising  and  depressing  the  leaves  of  the  heddles.    3'\  is  the  iron  shsdl 
which  carries  the  jacks  or  system  of  pulleys  j,  j,  j',  j'.    k,  a  strong  wooden  ruler,  con- 
necting the  front  heddle  with  its  treddle.     l,  l',  the  front  and  rear  marches  or  treddle- 
pieces,  for  depressing  the  heddle  leaves  alternately,  by  the  intervention  of  the  rods  fe, 
(and  k\  hid  behind  k).     m,  m,  are  the  two  swords  (swing  bars)  of  the  lay  or  batten,     n, 
is  the  upper  cross-bar  of  the  lay,  made  of  wood,  and  supported  upon  the  squares  of  the 
levers  n,'w',  to  which  it  is  firmly  bolted,    n',  is  the  lay-cap,  which  is  placed  higher  or 
lower,  according  to  the  breadth  of  the  reed;  it  is  the  part  of  the  lay  which  the  hand- 
loom  weaver  seizes  with  his  hand,  in  order  to  swing  it  towards  him.     n'  is  the  reed 
contained  between  the  bar  n,  and  the  lay-cap  n'.    o,  o,  are  two  rods  of  iron,  perfectly 
round  and  straight,  mounted  near  the  ends  of  the  batten-bar  n,  which  serve  as  guides  to 
the  drivers  or  peckers  o,  o,  which  impel  the  shuttle.     These  are  made  of  bufl'alo  hide, 
and  should  slide  freely  on  their  guide-rods,    o',  o',  are  the  fronts  of  the  shuttle-boxes ; 
they  have  a  slight  inclination  backwards,    p,  is  the  back  of  them.    See  figs,  1497  and  1498. 
o",  o",  are  iron  plates,  forming  the  bottoms  of  the  shuttle-boxes,    p,  small  pegs  or  pins, 
planted  in  the  posterior  faces  p  (fig.  1498)  of  the  boxes,  round  which  the  levers  p'  turn. 
These  levers  are  sunk  in  the  substance  of  the  faces  p,  turn  round  pegs  p,  being  pressed 
from  without  inwards,  by  the  springs  p'.    p'',fig.  1496,  (to  the  right  of  k,)  is  the  whip 
or  lever,  (and  q",  its  centre  of  motion,  corresponding  to  the  right  arm  and  elbow  of  the 
weaver,)  which  serves  to  throw  the  shuttle,  by  means  of  the  pecking-cord  p"y  attached  at 
its  other  end  to  the  drivers  o,  o. 

On  the  axis  of  q",  a  kind  of  eccentric  or  heart  wheel  is  mounted,  to  whose  concave 
part,  the  middle  of  the  double  band  or  strap  r,  being  attached,  receives  impulsion ;  its 
two  ends  are  attached  to  the  heads  of  the  bolts  r',  which  carry  the  stirrups  r",  that  may 
be  adjusted  at  any  suitable  height,  by  set  screws. 

s  (see  the  left-hand  side  of^g.  1496)  is  the  moving  shaft,  of  wrought  iron,  resting  on 
the  two  ends  of  the  frame,  s'  (see  the  right-hand  side)  is  a  toothed  wheel,  mounted  ex- 
teriorly to  the  frame,  upon  the  end  of  the  shaft  s.  s"  (near  s')  are  two  equal  elbows,  in  the 
same  direction,  and  in  the  same  plane,  as  the  shaft  s,  opposite  to  the  swords  m,  m,  of  the  lay. 
z,  is  the  loose,  and  z',  the  fast  pulley,  or  riggers,  which  receive  motion  from  the  steam- 
shaft  of  the  factory,  z",  a  small  fly-wheel,  to  regulate  the  movements  of  the  main  shaft 
of  the  loom. 

T,  is  the  shaft  of  the  eccentric  tappets,  cams,  or  wipers,  which  press  the  treddle  levers 
alternately  up  and  down  ;  on  its  right  end  is  mounted  t',  a  toothed  wheel  in  gear  with 
the  wheel  s',  of  one  haif  its  diameter,  t",  is  a  cleft  clamping  collar,  which  serves  to  sup- 
port the  shaft  t. 

u,  is  a  lever,  which  turns  round  the  bolt  w,  as  well  as  the  click  h'\  u',  is  the  click  of 
traction,  for  turning  round  the  cloth  beam,  jointed  to  the  upper  extremity  of  the  lever  u ; 
its  tooth  tt',  catches  in  the  teeth  of  the  ratchet  wheel  h".  tt",  is  a  long  slender  rod, 
fixed  to  one  of  the  swords  of  the  lay  m,  serving  to  push  the  lower  end  of  the  lever  u,  when 
the  lay  retires  towards  the  heddle  leaves. 

X,  is  a  wrought-iron  shaft,  extending  from  the  one  shuttle-box  to  the  other,  supported 
at  its  ends  by  the  bearings  x,  x. 

Y,  is  a  bearing,  affixed  exteriorly  to  the  frame,  against  which  the  spring  bar  z,  rests, 
near  its  top,  but  is  fixed  to  the  frame  at  its  bottom.  The  spring  falls  into  a  notch  in  the 
bar  Y,  and  is  thereby  held  at  a  distance  from  the  upright  a,  as  long  as  the  band  is  upon 
the  loose  pulley  z' ;  but  when  the  spring  bar  is  disengaged,  it  falls  towards  a,  and  carries  the 
band  upon  the  fast  pulley  z,  so  as  to  put  the  loom  in  gear  with  the  steam-shaft  of  the  factory. 
Weaving,  by  this  powerful  machine,  consists  of  four  operations  :  1.  to  shed  the  warp" 
by  means  of  the  heddle  leaves,  actuated  by  the  tappet  wheels  upon  the  axis  q',  the  rods 
fe,  fe',  the  cross-bar  e,  and  the  eyes  of  the  heddle  leaves  i,  i' ;  2.  to  throw  the  shuttle  (see 
fig,  1495),  by  means  of  the  whip  lever  p",  the  driver  cord  jt>,  and  the  pecker  o;  3.  to  drive 
home  the  weft  by  the  batten  n,  n';  4.  to  unwind  the  chain  from  the  warp  beam,  and  io 
draw  it  progressively  forwards,  and  wind  the  finished  web  upon  the  cloth  beam  H,  by 
the  click  and  toothed  wheel  mechanism  at  the  right-hand  side  of  the  frame.  For 


i 


!       i 


934 


WELD. 


rh,;**L  r  °  *^t  ^'^^^lonary,  I  shaU  give  here  a  short  notice  of  the  best  kind^ 

•hutUe  for  weaving  hair.    Fig.  1499,shows  in  plan  A,  and  in  longitudinal  sectioaB,, 


or  mouth,  wheaee  i^e^t^i:^'°I^^lt'':^'':SlLi  ''■'^' '°^«"t"  "«  «""«« «V  i"' 
mouth,  and  removing  L  ThLb    lets  ?L  L^r  K       "^i' k"*  ^/  ^^''  "^°*^>  ^"*°  ^^^ 

rollers,  x,  x.  are  likp  thn«P  nf  flir  „k„+*i  v  7  ^  weaver  s  leii  nana.  Ihelriction 
sbuttle  c'an'n'ot  be^l™r '  w'4  ftoS'sWe'  ZZ'"  Th?!'"?  -"venience,  a,  .he 
shuttle  opens  at  the  same  time  iL  tr>,f  if      3      .     ■  ^  '"""'  "'"'='»  receives  the 

5^»tt-d.t^o-ES£S^ 

S^^^w  ^i?^z^  -  »  S^  ?=^ 
a^ir-ii^i^dij^ifS^^ 

They  are  the'drp  Sb'eL  end. 

remain,  when  one  or  more  are  drawn  on/ h^^  Indian  rubber,  so  that  the  others 

flat  where  the  Indian  rrbersDr?n^  exert.  L.r/'-    ^K  ^°^\°^  ^^^  ^'^^^^s  are 
F.    The  spring  is  formed  by  S^  o^ft  1  i^^^^  f'  '^T^  ^^  ^he  dotted  line  at 

of  a  caoutehoSe  bouiror  flask  falniLtK^^^^  ^'^T  ^cT  ^^^  ^"•'^ature  of  the  neck 

the  groove  of  the  shmt?e  whLbv  the  "th-  **'"'?  ^'"^''1^  ^?'  ^'"'^  ^"^  *  ^^'^  ^'^P^^  ^" 
Ihe  inlaid  hairs,     w"  e  s^les  liL  /^^^^^^  ^^°"^  ^^'^  y^^ld,  presses  upon 

two  places  of  the  groove  Tgutter  to  nreUt  t^P  ^^^^^^  ^?  ^''  P^''"-^  ^^^^^^^^  ^^^«»gh 
of  the  s)-;ttle,  which  is  s"Srchar^.T;hh  t^^^^^^^^  '^""-"'"^  "J  ^'^  ^^^  midle 

across  th.     Vened  warn  with  thp  nnp  Ln^  '■•  u    .^  workman  shoves  the  tool 

of  hairs  b>  e  pro^^ctfnrends  and  hnlH^r'"'?  T'^  ^}?  °^^''  ^^^  requisite  number 
more  through  the  Xr^The  r'emLni  hi  «Tr  ^^'l'  ^^'J^^  K^'^"^'  '^^  «^"ttle  once 
and  only  those  for  the  single  dec^sat^^^^^^^^  I''  *^'  ^'^^"^^  ^^  ^^'  «P"»^«' 

on  either  side.     A  weaver  with  th?s  ton?  pT?     '°  ^^  ^^\,*°  ^'^  ^^cured  to  the  lis 
he  could  do  with  the  mouth-Ihuttle  "™  ^'^^  ^  **°"""  ^""^th  of  cloth  of  what 

run^Kl^::.rti^^^  ^^  ^^^  —  ^^  the  yarns  or  threads  whici 

^^cuZ^^To^I/'^u^^^^^^  -"-1  J'-baceous  plant, 

leaves  dye  yellow     and  aS^' the  di  p.  of  •*'  ^"'^'^  '"'''''''•     "^'^^  stems  and  the 

which  period  its  dyeing  power  is  ereateTt  •  /n/l  oO      t  ^^"^*^  "^f^^P^^  ^^^n  in  seed,  at 
the  market.  ^  ^  * '  ^''^  ^^^^'^  ^^ing  simply  dried,  is  brought  into 

Chevreul  has  discovered  a  yellow  coloring  principle  in  weld,  which  he  has  called 


WELLS,  ARTESIAN. 


935 


luteoline.    It  may  be  sublimed,  and  thus  obtained  in  long  needle-form,  transparent, 
yellow  crystals.    Luteoline  is  but  sparingly  soluble  in  water;  but  it  nevertheless  dyes 
alumed  silk  and  wool  of  a  fine  jonquil  color.    It  is  soluble  in  alcohol  and  ether;  it  com- 
bines with  acids,  and  especially  with  bases. 

When  weld  is  to  be  employed  in  the  dye-bath,  it  should  be  boiled  for  three  quarien 
of  an  hour;  after  which  the  exhausted  plant  is  taken  out,  because  it  occupies  too  much 
room.  The  decoction  is  rapidly  decomposed  in  the  air,  and  ought  therefore  to  be  made 
only  when  it  is  wanted.    It  produces,  with 


Solution  of  ising-glass 

Litmus  paper 

Potash  ley     - 

Solution  of  alum     - 

Protoxyde  salts  of  tin 

Acetate  of  lead 

Salts  of  copper 

Sulphate  of  red  oxyde  of  iron 


a  slight  turbidity. 
a  faint  reddening, 
a  golden  yellow  tint, 
a  faint  yellow. 
a  rich  yellow 

ditto 
a  dirty  yellow-brown 
a  brown,  passing  into  olive. 


precipitation. 


A  lack  is  made  from  decoction  of  weld  with  alum,  precipitated  by  carbonate  of  saicja  or 
potassa.    See  Yellow  Dye.  . 

WELDING  (Souder,  Fr. ;  Sckweissen,  Germ.),  is  the  property  which  pieces  of 
wrought  iron  possess,  when  heated  to  whiteness,  of  uniting  intimately  and  permanently 
under  the  hammer,  into  one  body,  without  any  appearance  of  junction.  The  welding 
temperature  is  usually  estimated  at  from  60°  to  90°  of  AVedgewood.  When  a  skilful 
blacksmith  is  about  to  perform  the  welding  operation,  he  watches  minutely  the  eflfect  of 
the  heat  in  his  forge-fire  upon  the  two  iron  bars;  and  if  he  perceives  them  beginning 
to  burn,  he  pulls  them  out,  rolls  them  in  sand,  which  forms  a  glassy  silicate  of  iron 
upon  the  surface,  so  as  to  prevent  further  oxydizement ;  and  then  laying  the  one  pro- 
perly upon  the  other,  he  incorporates  them  by  his  right-hand  hammer,  being  assisted 
by  another  workman,  who  strikes  the  metal  at  the  same  lime  with  a  heavy  forge- 
hammer. 

Platinum  is  not  susceptible  of  being  welded,  as  many  chemical  authors  have  erroneous- 
ly asserted. 

Mr.  T.  H.  Russell,  of  Handsworth,  near  Birmingham,  obtained  a  patent,  in  May,  1836J 
for  manufacturing  welded  iron  tubes,  by  drawing  or  passing  the  skelp,  or  fillet  of  sheet 
iron,  five  feet  long,  between  dies  or  holes,  formed  by  a  pair  of  grooved  rollers,  placed 
with  their  sides  contiguous ;  for  which  process,  he  does  not  previously  turn  up  the  skelp 
from  end  to  end,  but  he  does  this  so  as  to  bring  the  edges  together  at  the  lime  when  the 
welding  is  performed.  He  draws  the  skelp  through  two  or  more  pairs  of  the  above 
pincers  or  dies,  each  of  less  dimension  than  the  preceding.  In  making  tubes  of  an  inch 
of  internal  diameter,  a  skelp  four  inches  and  a  half  broad  is  employed.  The  twin  rollers 
revolve  on  vertical  axes,  which  may  be  made  to  approach  each  other  to  give  j)ressure ; 
and  they  are  kept  cool  by  a  stream  of  water,  while  the  skelp,  ignited  to  the  welding  heat, 
is  passed  between  them.  They  are  affixed  at  about  a  foot  in  front  of  the  mouth  of  the 
furnace,  on  a  draw-bench ;  there  being  a  suitable  stop  within  a  few  inches  of  the 
rollers,  against  which  the  workman  may  place  a  pair  of  pincers,  having  a  beU- 
mouthed  hole  or  die,  for  welding  and  shaping  the  tube.  In  the  first  passage  between  the 
rollers,  a  circular  revolving  plate  of  iron  is  let  down  vertically  between  them,  to  prevent 
the  edges  of  the  skelp  from  overlapping,  or  even  meeting.  The  welding  is  performed  at 
the  last  passage. 

WELLS,  ARTESIAN.  See  also  Artesian  Wells.  The  following  account  of  a 
successful  operation  of  this  kind,  lately  performed  at  Mortlake,  in  Surrey,  deserves  to 
be  recorded.  The  spot  at  which  this  undertaking  was  begun,  is  within  100  feet  of  the 
Thames.  In  the  first  instance,  an  auger,  seven  inches  in  diameter,  was  used  in  pene- 
trating 20  feet  of  superficial  detritus,  and  200  feet  of  London  clay.  An  iron  lube,  8 
inches  in  diameter,  was  then  driven  into  the  opening,  to  dam  out  the  land-sprinqs  and 
the  percolation  from  the  river.  A  4-inch  auger  was  next  introduced  through  the  iron 
tube,  and  tlie  boring  was  continued  until,  the  London  clay  having  been  perforated  to 
the  depth  of  240  feet,  the  sands  of  the  plastic  clay  were  reached,  and  water  of  the  softest 
and  purest  nature  was  obtained ,-  but  the  supply  was  not  suflBcient,  and  it  did  not  reach 
the  surface.  The  work  was  proceeded  with  accordingly ;  and  after  55  feet  of  alternating 
beds  of  sand  and  clay  had  been  penetrated,  ihe  chalk  was  touched  upon.  A  second 
tube,  4|  inches  in  diameter,  was  then  driven  into  the  chalk,  to  stop  out  the  water  of 
the  plastic  sands;  and  through  this  tube  an  auger,  3^  inches  in  diameter,  was  introduced, 
and  worked  down  through  35  feet  of  hard  chalk,  aboundinj?  with  flints.  To  this  succeeded 
a  bed  of  soft  chalk,  into  which  the  instrument  suddenly  penetrated  to  the  depth  of  15  feet. 
On  the  auger  being  withdrawn,  water  gradually  rose  to  the  surface,  and  overflowed. 
The  expense  of  the  work  did  not  exceed  300/.    The  general  summary  of  the  strata  pene- 


mmmr 


fl- 


936 


WHALEBONE. 


i!l   : 


lamipa.,  consisting  oUbreriaidlVag^^^^^^^^^  ^«   1^%-^'  ''    '"^^    ^^^^J 

thcfringes  upon  their  edges,  enable  the  anTmi^^n  ^ii   ^''f  "^'^^^  ""^  ^he  whale,  which,  by 
rows  of  teeth   (which  il  wants)    forbehveen     ^r     '  '""'"'  '"  ^^^  ^^^'^^  throigh 
detam  the  minute  creatures  upon  Xh  it  S     'C^fiT"'  i^^""?,^"^  ^^  *^^'^h  and 
lateral  cohesion,  as  they  are  nil  transverse  vd?p„/«^^^^^         ^^  whalebone  have  little 
detached  .n  the  form  of  Ion?  filamentrorXis.ies     ^.ll?,^^*^  """^^  '^'''^'''''  ^  ^'^^'^^7 
are  externally  compact,  smooth  and  ^.^L.!,  li      r       ^  f>J<^»y  or  scythe-shaped  plate/ 
ma  parallel  series,  by  ^hat  is  caS  tTe^^^^'o^l^jr^  P^'jf^'     ^hey  are'conn'ec^; 
side  of  Its  mouth,  to  the  number  of  about  ^M      -f-h  ^"/"^^'' ^^^  ^'^  arranged  along  each 
is  usually  found  near  the  middle  of  TeleT.'  i.Th     ^""""'^  f  '^^  '""^^^^  Wo^,  which 
designate  the  size  of  the  fish.    tL  greatest  ieni.h  S".'",^^?''''^  ^^  '^'  ^'^^'^^^  to 
but  It  rarely  exceeds  12  or  13      Th^t      }  u^^^.  hitherto  known  has  been  15  feet 
and  the  average  thicknes:  f'm  fiS    to%tV„\^  7^^  en^,ls  fron.  10  to  12  Inched; 
altogether  in  the  mouth  of  the  whale  resemble  1     '1  '",  T^'     J^'  ''''''>  ^^^^^d 
They  are  cleansed  and  soAened   befm-P  nn?r      '   u  ^V^'^^  *^'""'  ^he  roof  of  a  house, 
ewer.  ^"^  ^^*^'e  cutting,  by  boiling  for  two  hours  in  a  long 

Whalebone,  as  brought  from  Pro     i     j   • 
pieces,  comprising  ten  Ir  twelve  bTade."il' ''  commonly  divided  into  portable  junks  or 
separate  blades,  the  gum  ard'he  ha^J^frL^'l'  ^^'^  »«  occasionally  subdivided  into 
daring  the  voyage.      The  pric^^  whLetTfl,^.^.»  ?  **^'"   '!T"^  ^^  '^^  ^'^^o^ 


WHEEL  CARRIAGES.. 


a  carpenter's  bench,  and  is  then 


man,  takin*'  hold  of  th*.  h^r^At  ^  '  ^"^  ^^^^' 
Mn..  and  .U.  ..-.  ..„  i:;;;^  ^^^^^f^^^^^^ 
rection  of  the  fibres  ;  bein  "careful  to  cut  noL  Lr  Vk'"  ^'  ^°  ''^^"^  ««"  «  ^^''^^  i"  the  di- 
arethen  dried,  and  plinedle^elupo   the  "o^  J^'ese  prismatic  slips 

•n  this  operation,  is  used,  instead  of  hair  for  sLffinr'^nf*  ^^^^*>'-«"s  matter  detached 

From  Its  flexibili^,  stren-th  elasiirftv  In/vu,"  mattresses. 
purposes  :  for  ribs  to'umbrdlas  o ''j^ra Jol^^^^^^^^^  ^-P'^^ed  for  many 

hats,  &c.     When  heated  by  steam,  or  a  sand  bath    f  LT^  ''^^'V   ^^^  ^^^  f'^me-work  of 
like  horn,  into  various  shapes,  wSch  it  retainrj^T  ;  " 'f  ^">  ^"^  ™ay  be  bent  or  moulded, 
Snuff-boxes,  and  knobs  of  wa^kir.sticL  marbe^^^^^     ""'^"^  compression.    In  this  way 
The  surface  is  polished  at  first  wifh  grind'  pumice  stonT  feh  '''f '^  ^^^^^  '^ '''  ^'^^'• 
with  dry  quicklime,  spontaneously  slaked  and  S'  ^"'  °"^  '^^*^''   «»d  finished 

increase  their  thickness,  so  as'  Trender  the  mateZr''"i^  *??  ''/'^'  ^^  ^'^^'^  ^ 
sticks,  whip  handles,  parasol  and  umbrella  stiTk-^r^i  ^^/''^^\^  ^^'^^ir^g  walking, 
accomplishes  this  by  bending  the  stnl  to'ether^ntroT  •'^''  .r''"-"^  ^«^'«'  *<^  H^ 
thereby  softening  them,  and  in  that  staTe  coCre  JnTth^^^^^  '"'^  ^  ^^^^"^  «»»e«t^ 

propriate^machinery ;  for  a  description.  ^^.'^.T^o^ZZ:,  Sn'Vr.'j, ^ 

<lua^Sn1  SVhrfitf  ,^utt;  re  t/r/--  ^^.^  ^-'-^^^ed  in  the  largest 
incessant  and  eager  V^nsuitXotlnlJ  for  ttfTlT^^^^^^^^^      \^''^  ^«  ^he  object  of 

immense  suoply  of  oil  which  is  obtaine^dfrL  the  t^^^^^^^^  but  fir  the 

fat,  in  whicti  the  body  is  enveloped.     The  Llth  nf  ^  ^     of  blubber,  or  cutaneous 

whale  60  feet  long,  is  frequently  as  much  as  ?l  Lf     a  If'^?^  P'"'"  ^^  ^«^«««  i"  a 

TjfT''  «««h  containing  about  300  in  number  '"*  ^^^  arranged  in 

whi^.h\'rrof;o^tt:iuf  in'tm^:^^^^^^^^^  form,  the  largest, 

each  s,de  of  the  upper  jaw  of  the  "  wh^leboL  ^^^^^^^^  JL'J "f  ^^r ^''"1*"^^  '''''''  ^^ 
and  ending  m  a  fringe  of  bristles:  the  smalU  nkl  V  '^"^^^f  ^"'^'^'"^^^^^'cally 
iiiternal  to  the  marginal  onea  The  bai  of  eacE  olafe  L'  Ti?"^'^  i°  ^^"^^^  ^"e( 
pnlp  developed  from  a  vascular  germ.  whi2  isVJcte^^  t^tbToa^ aid'shl^^^^^^^^^^ 


937 


pression  occupying  the  whole  of  the  palatal  surface  of  the  maxillary  bones.  The 
plates  are  so  disposed  as  that  their  fringed  terminations  are  directed  downward  and 
inclining  toward  the  back  part  of  the  mouth,  and  they  prevent  the  escape  of  the  small 
marine  animals  which  constitute  the  food  of  the  great  whales  (Balfenie),  for  the 
prehension  of  which  this  singular  substitute  is  adapted.  The  baleen  plates  are  smallest 
at  the  two  extremities  of  the  series;  the  large  intermediate  one  sometimes  attains  the 
length  of  15  feet,  being  above  a  foot  broad  at  the  base.  There  are  about  200  plates  in 
outer  row  on  each  side  of  the  mouth  in  the  "  true  whale"  {Balcena  mysticetus).     Each 

{)late  consists  of  a  central  coarse  fibrous  substance  and  an  exterior  compact  fibrous 
ayer:  but  this  reaches  to  a  certain  extent  only,  beyond  which  the  central  part  projects 
in  the  form  of  a  fringe  of  bristles.  The  chemical  base  of  baleen  is  albumen  hardened 
by  a  small  proportion  of  phosphate  of  lime.  The  baleen  plates  of  the  finners  or  hump- 
backed whales  {Balcenotera)  are  smaller  and  of  less  value  than  those  from  the  true 
whale  {Balcena  mysticetus). 

WHEAT.  {Triticum  vulgare^  Linn.;  Froment,  Fr.;  Waizeti,  Germ.)  See  Bread, 
Gluten,  and  Starch. 

Wheat  Flour;  to  detect  adulteration  of .  Potato  starch  is  insoluble  in  cold  water, 
unless  it  be  triturated  in  thin  portions  in  a  mortar.  If  pure  wheat  flour  be  thus  triturated, 
it  affords  no  trace  of  starch  to  iodine,  as  the  former  does,  because  the  particles  of  wheat 
starch  are  very  minute  and  are  sheathed  in  gluten. 

Bean  flour  digested  with  water  at  a  heat  of  68°  Fahr.  and  triturated  affords  on 
filtration  a  liquid  which  becomes  milky  on  the  addition  of  a  little  acetic  acid,  by  its 
reaction  on  the  legumine  present  in  the  beans. 

WHEEL  CARRIAGES.  Though  this  manufacture  belongs  most  properly  to 
a  treatise  upon  mechanical  engineering,  I  shall  endeavor  to  describe  the  parts  of  a 
carriage,  so  as  to  enable  gentlemen  to  judge  of  its  make  and  relative  merits.  The 
external  form  may  vary  with  every  freak  of  fashion ;  but  the  general  structure  of  a 
vehicle, 'as  to  lightness,  elegance,  and  strength,  may  be  judged  of  from  the  following 
figure  and  description. 

JFig.  1502  shows  the  body  of  a  chariot,  hung  upon  an  iron  carriage,  with  iron  wheels, 
•xletrees,  and  boxes ;  the  latter,  by  a  simple  contrivance,  is  close  at  the  out-head,  by 
which  means  the  oil  cannot  escape ;  and  the  fastening  of  the  wheel  being  at  the  in-head, 
as  will  be  explained  afterward,  gives  great  security,  and  prevents  the  possibility  of  the 
wheel  being  taken  off  by  any  other  carriage  running  against  it. 

Mg.  1603  shows  the  arm  of  an  axletree,  turned  perfectly  true,  with  two  collars  in 
the  solid,  as  seen  at  g  and  h.     The  parts  from  g  to  b  are  made  cylindrical.     At  a  is  a 
screw  nail,  the  purpose  of  which  will  be  explained  in^^.  1607. 
1502 


Fig.  1504,  is  the  longitudinal  section  of  a  metal  nave,  which  also  forms  the  bush,  fof 
the  belter  fitting  of  which  to  the  axletree,  it  is  bored  out  of  the  solid,  and  made  quite  air 
light  upon  the  pin ;  and  for  retaining  the  oil,  it  is  left  close  at  the  out-head  d. 

Fig.  1505,  represents  a  collet,  made  of  metal,  turned  perfectly  true  the  least  diameter 


938 


WHEEL  CARRIAGES. 


1507 


WHEEL  CARRIAGES. 


939 


in  the  collet,  w,  w  a  can^  honn "Iffl  •  \i  J  ""^ }^^  ^"'^'  »"^  ^"'n?  "P  the  eroovei 
made  fast  to  the'b^'sh  Screws''  TMs  hooj;  wh'^  '"  7^^'  '"^^  ^"^^  «^  ^-^  P^ns  ani 
the  possibility  of  the  pinVr^T^rom  j^^rout  of^hpi^\'"'^  '"  '^'  bush/preients 
washer,  interposed  betwixt  the  in  head  of  "he  bu^J  Ind  tlfiT'*  *'',"/  ^'  *  ^^«^^" 
axletree,  to  prevent  the  escape  of  oil  at  the  in  L,^  •  ^  '^'■^^''  "^^^^  ^o'^^^"  ^^  <he 

IS  near  the  letter  k,  in  /Z^  1503  Th.l  L  k  ^  ""'  "f  ^  ^*^'"^^'  ^^e  head  of  which 
hole  it  flows  down  'the  &  in  L  cintre  of  the  a'^f^  ""^'"''  '"?  ""  ^^"^^^  '"^0^2 
by  the  arm,  being  about  one  inch  shorter  th«ni>f  ^  '^r  u'™.'  ^"^  ^"«  ^^^  ^pace  b,  left 
afterwards  replaced,  keeps  a  f  tVht  /„  nmtit  nn'?>,°^'^^  ^?^'  ""^  ^'^^  ^^"^^»  being 
put  into  the  space  betwixt  tne  collet- p  s  aC  th^e  l«rl  '  ''^.:'^'  *i"""  «"  «"«»»'  '<>  be 
moveable  round  the  axletree  ara,,  and  Vein.  maSe  /ast^to  ,'h"^'^  k  ?'  """"  ^>  ^''  ^'^^S 
pins  5,  ^,  revolves  along  with  the  bush,  actfn^aaain.rthVr^'n^-''  '"^^"^  °^  ^^^  ^wo 
keeps  the  wheel  fast  to  the  axletree,  untH  bv  "reSnl  n   '""^'^  ?u^'  ^'  ^^  ^''^  «™>  *"<! 

"The7'"t^'.^'  ^'^  ^""^^  ''<^^o-es'd"en,akdTorth^^b^^^  '  "'  "'  '^^^  '""^» 

The  dovetail,  seen  upon  ihe  collet  atr  iv  i.-nl-  !.  • 

bash,  to  receive  it,  in  consequence  of  which  fh<.\!^'..  *  <'°'''?sPO'"ling  groove  cnt  in  the 
Ihe  collel  and  pins  m  exactl}/  Thie  wheeb  '"'  r"«'l'"  "^"'"'''"^  *>'  I""  «"  S"  ">« 
win  run  a  thousand  miles  without  requTrinrfrlsTo  ,1^.'^  '""""  '"  ^  ""''»  ""^  ^'^  "»«/ 

sX:wh':hti^s,TeU;'aitn  HHr^^^^^^^^^^^ 

together  by  rivets  through  them  The  sna.i  h'?'^^  /u^^  ^*'"'!^''  ^"'^  ^"  ^'^-^^  are  attached 
Should  be  filled  up  with^light Tv^od  the  Ure  the7nu^"o^  '''?r"  "T  ^^^'"'"^  ^^^  ^^^^oet 
and  glands  clasping  both  felloes  ^        '  '^"'^  fastened  to  the  felloes  by  bolts 

.vp?ne :s;tt;  rhr;'r;o7.'hXri^,-t"  ^t'  "^^"^  '''"^- "  '^. « « 

pre^tettfni^'^Vla^re^K"^^^^^^^ 

in  the  boxes  of  the  wheels  Ssob^ectTseffeS'hv',!,"  "■"',"1''  ""''""  '^"'-  ^hl.kin1 
in  certain  parts  of  the  box,  and  brfcontnt,^!  •  '^ ',''\'" V''^'''''™ '''" '^"h''  «>»»» 
so  as  to  bear  against  the  end  of  the  axTeJee  wUh',!* '""  '^""'1'  "'"'  '"  ""'""i  »p! 
that  situation,  without  the  possibility  of  turnin^lnd\r'5'if'  "-^  'f^""?'  ""^  '^  "-^W  i» 
loose.  '  "'  '■"""'•=  found,  or  allowing  the  axletree  to  become 

Mff.  1608  shows  the  section  of  the  hn^,  «f  »  1.1  •  ■  . 
secured  in  it  The  general  form  of  the  box  andTf  tt  T?"  w,  '"^  ^^  ^^'  '^^^^tree 
axles,  there  being  recesses  in  the  box  for  th;  reeenLn  f  '{  ''  ^!'  f '"^"  ^'  ^^^''  "^^^ 
a  cap  «  is  inserted,  with  a  leather  col laJ  enclosed^n^?  k/'!'  ^^  ^^^  ^"^  «^  ^^e  axle, 
axle;  which  cap,  when  screwed  up  sufficient  vtthf  t  l  m -^  *l^'^"?'  *^«  ^"<^  «^  ^he 
or  screw  passed  through  the  cap  a,  into  the  e"^  of  the  '1^  '^  *^'^  '^^""^^^"  ^^  «  P^" 
end  of  the  iron  box  being  shown  at/y.  I609  '*'''  *  representation  of  thi« 


1508 


1609 


Jn  the  can  a,  there  is  also  a  groove  for  conducting  the  oil  to  the  interior  of  the  box,  wilk 
a  screw  at  the  opening,  to  prevent  it  running  out  as  the  wheel  goes  round. 

The  particular  claims  of  improvement  are,  the  leather  collar  aarainst  the  end  of  the  axle ; 
the  pin  going  through  one  of  the  holes  in  the  end  of  the  box,  to  fix  it ;  and  the  channel  for 

conducting  the  oil. 

Mr.  Mason's  patent,  of  August,  1830,  applies  also  to  the  boxes  and  axles  of  that  con- 
struction of  carriage  wheels  which  are  fitted  with  the  so  called  mail-boxes ;  but  part  of  the 
invention  applies  to  other  axles. 

Fig.  1510,  represents  the  nave  of  a  wheel,  with  the  box  for  the  axle  within  it,  both 
shown  in  section  longitudinally;  fig.  1511,  is  a  section  of  the  axle,  taken  in  the  same 
direction  ;  andyig.  1512,  represents  the  screw  cap  and  oil-box,  which  attaches  to  the  outer 
extremity  of  the  axle-box.  Supposing  the  parts  were  put  together,  that  is,  the  axle  inserted 
into  the  box,  then  the  intention  of  the  different  parts  Avill  be  perceived. 

The  cylindrical  recess  a,  in  the  box  of  the  nave,  is  designed  to  fit  the  cylindrical  part 
of  the  axle  6 ;  and  the  conical  part  c,  of  the  axle,  to  shoulder  up  against  a  corresponding 
conical  cavity  in  the  box,  with  a  washer  of  leather  lo  prevent  its  shaking.  A  collar  d, 
formed  by  a  metallic  ring,  fits  loosely  upon  a  cylindrical  part  of  the  axle,  and  is  kept  there 
by  a  flange  or  rim,  fixed  behind  the  cone  c.  Several  strong  pins  /,/,  are  cast  into  the 
back  part  of  the  box ;  which  pins,  when  the  wheel  is  attached,  pass  through  corresponding 
holes  in  the  collar  d ;  and  nuts  being  screwed  on  to  the  ends  of  the  pins/,  behind  the  collar, 
keep  the  wheef  securely  attached  to  the  axle.  The  screw-cap  g,  is  then  inserted  into  the 
recess  h,  at  the  outer  part  of  the  box,  its  conical  end  and  small  tube  i,  passing  into  the  recess 
fe,  in  the  end  of  the  axle. 

The  parts  being  thus  connected,  the  oil  contained  within  the  cap  g,  will  flow  through 
the  small  tube  t,  in  its  end,  into  the  recess  or  cylindrical  channel  /,  within  the  axle,  and  will 
thence  pass  through  a  small  hole  in  the  side  of  the  axle,  into  the  cylindrical  recess  a,  of 
the  box ;  and  then  lodging  in  the  groove  and  other  cavities  within  the  box,  will  lu- 
bricate the  axle  as  the  wheel  goes  round.  There  is  also  a  small  groove  cut  on  the  out- 
side of  the  axle,  for  conducting  the  oil,  in  order  that  it  may  be  more  equally  dis- 
tributed over  the  surface  and  the  bear- 
ings. This  construction  of  the  box  and 
axle,  as  far  as  the  lubrication  goes,  may 
be  applied  to  the  axles  of  w^heels  in 
general ;  but  that  part  of  the  invention 
which  is  designed  to  give  greater  secu- 
rity in  the  attachment  of  the  wheel  to 
the  carriage,  applies  particularly  to  mail 
axles. 

Mr.  William  Mason's  patent  in- 
vention for  wheel  carriages,  of  August, 
1831,  will  be  understood  by  reference 
to  the  annexed  figures.  Fig.  1513,  is  a 
plan  showing  the  fore-axlelree  bed  a,  a, 
of  a  four-wheeled  carriage,  to  which 
the  axletrees  6,  6,  are  jointed  at  each 
end  ;  fig.  1514  is  an  enlarged  plan  ;  and 
fig.  1515  an  elevation,  or  side  view  of  one 
end  of  the  said  fore-axletree  bed,  having 
a  Collinge's  axletree  jointed  lo  the 
axletree  bed,  by  means  of  the  cylindrical  pin  or  bolt  e,  which  passes  through  and  turns 
in  a  cylindrical  hole  d,  formed  at  the  end  of  the  axletree  bed,  shown  also  in  the  plan 
view,/5f.  1516,  and  section, /^r.  1517. 

The  axletree  6,  is  firmly  united  with  the  upper  end  e,  of  the  pin  or  bolt  c  ;  and  to  the 
lower  end  of  it,  which  is  squared,  the  guide  piece  /,  is  also  fitted,  and  secured  by  the 
screw  ^r,  and  cap  or  nut  h,  seen  \nfig.  1515,  and  in  section  in  fig.  1518.  There  are  leather 
washers  i,  i,  let  into  recesses  made  to  receive  them  in  the  parts  a,  b,  and/,  the  intent  of 


1510 


■ 


HQ 


U22> 


WHEEL  CARRIAGES. 
1^8        1517     1616        1614 


po8iteforeaxIetree?r  iSlV^    -''^^  fore-axletree  bed  T  In  L7Zl      \^i.°^^  ^' 


jser^w^  O.J  "  -*^^.  T^^  ^^«  gu'de  piece  f.  tnrna    n.^  fi 


similar  mannef  "^  Th.  tV^'i  ^^PP^^'^^  ^"^  «f  the  TXte^^ 
The^axletree  may  be  incased  in  th.         .       .  '    '  "'  '''"^^  ^'^ 


Til 


WHEEL  CARRIAGES. 


941 


small  compass,  by  throwing  the  axles  of  all  the  four  wheels  simultaneously  into  different 
positions.      They  effect  this  object  by  mounting  each  wheel  upon  a  separate  jointed 

axle,  and  by  connecting  the  free 
ends  of  the  four  axles  by  jointed  rods 
or  chains,  wiih  the  pole  and  splinter- 
bar  in  front  of  the  carriage. 

To  fix  the  ends  of  the  spokes  of 
wheels  to  the  felloe  or  rim,  with 
greater  security  than  had  been  ef- 
fected by  previous  methods,  is  the 
object  of  a  contrivance  for  which 
William  Howard  obtained  a  patent, 
in  February,  1830.  Fig.  1527  shows 
a  portion  of  a  wheel  constructed  on 
this  new  method ;  a,  is  the  nave, 
of  wood ;  6,  6,  6,  wooden  spokes, 
inserted  into  the  nave  in  the  usual 
,  way ;   c,  c,  is  the  rim  or  felloe,  in- 

tended to  be  formed  by  one  entire  circle  of  wrought  iron;  d,  and  e,  e,  are  the  shoes 
or  blocks,  of  cast  iron,  for  receiving  the  ends  of  the  spokes,  which  are  secured  by  bolts 
to  the  nm  on  the  inner  circumference.  The  cap  of  the  block  d,  is  removed,  for  the 
purpose  of  showing  the  internal  form  of  the  block ;  e,  e,  have  their  caps  fixed  on,  as 
they  would  appear  when  the  spokes  are  fitted  in.  One  of  the  caps  or  shoes  is  shown 
detached,  upon  a  larger  scale,  at  Jig.  1528,  by  which  it  will  be  perceived  that  the  end 
1528  of  the  spoke  is  introduced  into  the  shoe  on  the  side.     It  is  proposed 

that  the  end  of  the  spoke  shall  not  reach  quite  to  the  end  of  the 
recess  formed  in  the  block,  and  that  it  shall  be  made  tis[ht  by  a 
wedge  driven  in.     The  wedge  piece  is  to  be  of  wood,  as  fig.  1193, 
with  a  small  slip  of  iron  within  it ;   and  a  hole  is  perforat^  in  the 
Uck  of  the  block  or  shoe,  for  the  wedge  to  be  driven  through.     When  this  is  done,  the 
ends  of  the  spokes  become  confined  and  tight ;   and  the  projecting   extremities  of  the 
1529     wedges  being  cut  off,  the  caps  are  then  attached  on  the  face  of  the  block,  as  at 
f":g     €,  e,  by  pins  riveted  at  their  ends,  which  secures  the  spokes,  and  renders  it 
■—-^     impossible  for  them  to  be  loosened  by  the  vibrations  as  the  wheel  passes 
over  the  ground.     One  important  use  of  the  wedges,  is  to  correct  the  eccentric  figure  of 
the  wheel,  which  may  be  readily  forced  out  in  any  part  that  may  be  out  of  the  true 
form,  by  driving  the  wedffe  up  further ;   and  this,  it  is  considered,  will  be  a  very  im- 
portant advantage,  as  the  nearer  a  wheel  can  be  brought  to  a  true  circle,  the  easier  it 
will  run  upon  the  road.     The  periphery  of  the  wheel  is  to  be  protected  by  a  tire, 
which  may  be  put  on  in  pieces,  and  bolted  through  the  felloe;   or  it  may  be  made  in  one 
ring,  and  attached,  while  hot,  in  the  usual  way. 

Mr.  Reedhead's  patent  improvements  in  the  construction  of  carriages,  are  represented 
in  the  following  figures.     They  were  specified  in  July,  1833. 

Fig.  1530,  is  a  plan  or  horizontal  view  of  the  fore  part  of  a  carriage,  intended  to  be 
drawn  by  horses,  showing  the  fore  wheels  in  their  position  when  running  in  a  straight 
course;  fig.  1531,  is  a  similar  view,  showing  the  wheels  as  locked,  whei.  in  the  act  of 

1530  1531 


I 


turning;  fig.  1532,  is  a  front  end  elevation  of  the  same ;  fig.  1533,  is  a  section  taken 
through  the  centre  of  the  fore  axletree  ;   and  fig.  1534,  is  a  side  elevation  of  the  general 


942 


WHEEL  CARRIAGES. 


WHEEL  CARRIAGES. 


943 


m^ 


appearance  of  a  stage-coach,  with  the  improvements  appended  ;  a,  a,  are  two  splinter- 
bars,  with  their  roller  bolts,  for  connecting  the  traces  of  the  harness ;  these  splinter  bars 
ire  atlached,  by  the  bent  irons  b,  b,  to  two  short  axletrees  or  axle-boxes  c,  c,  which  carry 
Ihe  axles  of  the  fore  wheels  rf,  d,  and  turn  upon  vertical  pins  or  bolts  «,  «,  passed  through 
the  fore  axletree  /,  the  splinter-bars  and  axle-boxes  being  mounted  so  as  to  move 
parallel  to  each  other,  the  latter  partaking  of  any  motion  given  to  the  splinter-bars  by 
the  horses  in  drawing  the  carriage  forward,  and  thereby  producing  the  locking  of  the 
wheels,  as  shown  in  Jig.  1531 ;  and  in  order  that  the  two  wheels,  and  their  axles  and 
axle-boxes,  together  with  the  splinter-bars  a,  </,  may  move  simultaneously,  the  latter  are 
connected  by  pivots  to  the  end  of  the  links  or  levers  g,  g,  which  are  attached  to  the  arms 
t,  f,  which  receive  the  pole  of  the  coach  by  a  hinge-joint  or  pin  h ;  the  arms  t,  t,  turning 
on  a  yerticjvl  fulcrum-pin  fc,  passed  through  the  main  axletree/,  as  the  pole  is  moved  from 
one  side  to  the  other. 

The  axles  o,  o,  are  firmly  fixed  into  the  naves  of  the  wheels,  as  represented  in  the  side 
view  of  a  wheel  detached,  at  yig.  1536,  the  axles  being  mounted  so  as  to  revolve  within 
their  boxes  in  the  following  manner : —  The  axle-boxes,  which  answer  the  purpose  of 
short  axletrees,  are  formed  of  iron,  and  consist  of  one  main  or  bottom  plate  /,  seen  best 
in  Jigs.  153G  and  1535 ;  upon  this  bottom  plate  is  formed  the  chamber  m,  m,  carrying 
the  two  anti-friction  rollers  w,  w,  which  turn  on  short  axles  passed  through  the  sides  and 
partition  at  the  upper  part  of  the  chambers.  These  anti-friction  rollers  bear  upon  the 
cyhndrical  parts  of  the  axle  o,  of  each  wheel,  and  support  the  weight  of  the  coach;  p,  is 
a  bearing  firmly  secured  in  the  axle-box  to  the  plate  Z,  for  the  end  of  the  axle  o  to  run 
1532  1533 


1536 


m,  the  axle  being  confine/  in  its  proper  situation  by  a  collar  and  screw-nut  on  its  end; 
i^  is  the  vertical  pin  or  bolt  before  mentioned,  upon  which  the  axle-bar  turns  when  the 
wheels  are  locking,  which  bolt  is  enlarged  within  the  box,  and  has  an  eye  foi  the  axle 
to  pass  through,  being  firmly  secured  to  the  plate  /,  and  also  to  the  sides  of  the  box.   Fig, 

1536,  is  a  plan  or  horizontal  view  of  an  axle  and  its  box,  belonging 
to  one  of  the  fore  wheels ;  a  piece  q,  is  fixed  to  the  under  side  of  the 
main  axletree,  which  supports  the  ends  of  the  plates  /,  and  thereby 
relieves  the  pins  «,  e,  of  the  strain  they  would  otherwise  have  to 
withstand.  'I'he  axles  of  the  hind  wheels  are  mounted  upon  similar 
plates /,  Z,  with  bearings  and  chambers  with  anti-friction  rollers; 
but  as  these  are  not  required  to  lock,  the  plates  /,  /,  are  fixed  on  to 
the  under  side  of  the  hind  axletree  by  screw-nuts ;  there  are  small 
openings  or  doors,  which  can  be  removed  for  the  purpose  of  un- 
screwing the  nuts  and  collars  of  the  bearings  p,  when  the  wheel  is 
required  to  be  taken  off  the  carriage,  when  the  axle  can  be  with- 
drawn from  the  boxes.  If  it  should  be  thought  necessary,  other 
chambers  with  friction  rollers  may  be  placed  on  the  under  side  of 
the  plale  Z,  to  bear  up  the  end  of  the  axles,  and  relieve  the  bearing 
p.  In  order  to  stop  or  impede  the  progress  of  a  carriage  in  passing 
down  hills,  there  is  a  grooved  friction  or  brake  wheel  /,  fixed,  by 
clamps  or  otherwise,  on  to  the  spokes  of  one  of  the  hind  wheels ; 
«,  is  a  brake-band  or  spring,  of  metal,  encircling  the  friction  wheel,  one  end  of  which 
band  is  fixed  into  the  standard  v,  upon  the  hind  axletree,  and  the  other  end  con- 
nected by  a  joint  to  the  shorter  end  of  the  lever  w,  which  has  its  fulcrum  in  the  standard 
this  lever  extends  up  to  the  hind  seat  of  the  coach,  as  shown  in  Jig.  1198,  and  is  in- 


V 


tended  to  be  under  the  command  of  the  guard  or  passengers  of  the  coach,  and  when  de- 
scending a  hill,  or  on  occasion  of  the  horses  running  away,  the  longer  end  of  the  lever  is 
to  be  depressed,  which  will  raise  the  shorter  end,  and,  consequently,  bring  the  band  or 
spring  tt,  in  contact  with  the  surface  of  the  friction  wheel,  and  thereby  retard  its  revolu- 


tion, and  prevent  the  coach  travelling  too  fast;  or,  instead  of  attaching  the  friction 
brake  to  the  hind  wheel,  as  represented  in  ^g.  1534,  it  may  be  adapted  to  the  fore 


1635 


1634 


wheels,  and  the  end  of  the  lever  brought  up  to  the  side  of  the  foot-board,  or  under  it^ 
and  within  command  of  the  coachman,  the  standard  which  carries  the  fulcrum  being 
made  to  move  upon  a  pivot,  to  accommodate  the  locking  of  the  wheels.  It  will  be 
observed,  that  by  these  improved  constructions  of  the  carriage  and  mode  of  locking,  the 
patentee  is  enabled  to  use  much  larger  fore  wheels  than  in  common,  and  that  the 
splinter-bars  will  always  be  in  the  position  of  right  angles  with  the  track  or  way  of  the 
horses  in  drawing  the  carriage,  by  which  they  are  much  relieved,  and  always  pull  in  a 
direct  and  equal  manner. 

A  manifest  defect  in  all  four-wheeled  carriages,  involving  vast  superfluous  friction,  .8 
the  small  size  of  the  front  wheels ;  a  defect  which  has  existed  ever  since  Walter  Rippon 
made  "  the  first  hollow  turning  coach  with  pillars  and  arches  for  her  majesty  Queen 
Mary,  being  then  her  servant,'*  until  the  railroad  era,  when  our  engineers  remedied  the 
defect  by  equalizing  the  wheels,  at  the  expense  of  another  defect — sacrificing  the  power 
of  turning,  and  thus  producing  great  lateral  friction;  whence  a  train  of  evil  consequences 
result : — necessarily  increased  strength,  and  consequently  increased  weight  of  the  carria- 
ges; increased  power  and  weight  of  the  engine  to  draw  them,  and  overcome  the  friction  j 
and,  of  course,  mcreased  strength  of  rails,  and  greater  solidity  of  railway. 

These  defects  are  at  last  remedied  by  an  invention  patented  by  Mr.  William  Adams, 
author  of  a  work  entitled  "  English  Pleasure  Carriages."  Instead  of  placing  the  perch- 
bolt,  or  turning  centre,  as  is  commonly  done,  over  the  front  axle,  he  places  it  at  a  con* 
yenient  distance  between  the  front  and  hind  axles ;  so  that  when  turning  the  carriage  th( 
front  wheels,  instead  of  turning  beneath  the  body,  as  is  common,  turn  outside  of  it,  ana 
the  driver'i  seat  turns  with  them ;  thus  giving  him  a  perfect  command  over  his  horses  in 
all  positions,  instead  of  the  usual  dangerous  plan,  which  renders  a  driver  liable  to  be 
pulled  ofl'  his  box  by  a  restiflf  horse,  when  in  the  act  of  turning.  A  carriage  constructed 
on  Mr.  Adams's  plan  may  also  be  driven  round  a  corner  at  full  speed,  without  any  risk  of 
overturning,  as  the  weight  is  equally  poised  on  the  axles  in  all  positions.  It  is  well  known 
that  the  oversetting  of  stage  coaches  usually  takes  place  when  turning  a  corner,  the 
momentum  urgin/g  the  vehicle  in  a  right  line,  while  the  horses  are  pulling  at  an  angle. 
By  the  new  arrangement  the  front  wheels  may  be  made  equal  to  the  hind  ones,  or  of  any 
desirable  height,  and  at  the  same  time  the  body  may  be  kept  as  low  as  may  be  thought 
convenient,  even  almost  dose  to  the  ground,  if  desired.  Thus  two  important  objects, 
hitherto  deemed  incompatible,  are  combined — high  wheels  and  a  low  centre  of  gravity. 
These  carriages  are  therefore  essentially  safely  carriages,  while  the  friction  is  reduced  to 
a  minimum.  The  principle,  in  its  various  modifications,  is  applicable  to  every  variety  of 
carriage,  both  those  of  the  simply  useful  kind,  and  those  where  beauty  of  form  and  color 
are  prime  requisites. 

Another  most  important  part  of  Mr.  Adams's  invention,  is  his  new  mode  of  spring  sus- 
pension ;  applying  the  principle  of  the  bow  and  string,  for  the  first  time,  to  obviate  the 
eflfects  of  concussion  in  wheel  carriages.  All  the  springs  hitherto  in  use  for  wheel  carria 
ges,  have  been  friction  springs,  composed  of  Ion?  sliding  surfaces,  uncertain  in  their  ac 
tion,  and  liable  to  quick  destruction  by  rust.  Bui  Mr.  Adams's  springs  are  essentially 
elastic,  being  formed  of  single  plates  abutting  endways,  so  that  all  friction  is  removed, 
and  they  can  be  hermetically  sealed  within  paint  to  prevent  their  corrosion.  He  has 
various  modes  of  applying  the  bow,  either  single  or  double,  above  or  below  the  axle;  but 
one  most  important  feature  is,  that  the  axle  being  attached  to  the  flexible  cords  or  braces, 
the  concussion  which  aflfects  the  wheels,  either  laterally,  vertically,  or  in  the  line  of  pro- 


■  I 


I 


944 


WHEEL  CARRIAGES. 


gress,  is  perfectly  intercepted,  without  the  unpleasant  oscillation  eacperienced  in  car- 
riages where  the  same  purpose  is  accomplished  by  the  use  of  the  curved  or  C  spring. 
Mr.  Adams'  brace  being,  at  the  sanae  time,  a  non-conductor  of  sound,  the  rattling  of  the 
wheels  does  not  annoy  the  rider  as  in  ordinary  cai-riages.  His  springs  are  equally 
applicable  to  vehicles  with  two  and  four  wheels.  m      J 

The  advantages  of  these  carriages  may  be  thus  summed  up:— A  great  diminution  of 
the  total  weight;  a  diminution  of  resistance  in  draught  equal  to  about  one  third-  in- 
crease of  safety  to  the  riders;  increased  durability  of  the  vehicle;  absence  of  noise'and 
vibration ;  absence  of  o3cillation. 

To  these  qualities,  so  desirable  to  all,  and  especially  those  of  delicate  nervous  tem- 
perament, may  be  added— greater  economy,  both  in  the  first  cost  and  maintenance. 

The  whirling  public  so  blindly  follows  fashionable  caprice  in  the  choice  of  a  carriage 
as  to  have  hitherto  paid  too  little  attention  to  this  fundamental  improvement;  but  many 
intelligent  individuals  have  fully  verified  its  practical  reality.  Having  inspected  various 
forms  of  two-wheeled  and  four-wheeled  carriages,  in  the  patentee's  premises  in  Drury 
Lane,  I  feel  justified  in  recommending  them  as  being  constructed  on  the  soundest  me- 
chanical principles ;  and  have  no  doubt,  that  if  reason  be  allowed  to  decide  upon  their 
merits,  they  will  ere  long  be  universally  preferred  by  all  who  seek  for  easy-movinff 
safe,  and  comfortable  vehicles. 

Among  the  wheel  carriages  displayed  in  the  Exhibition  one  of  the  most  remarkable 
was  the  amempton  {unblamable)  of  R  Kesterton,  Long  Acre.  It  is  a  close  double-seated 
carnage,  which  by  a  simple  contrivance  can  be  converted  in  a  light,  open,  step-piece, 
barouche,  adapted  for  summer  and  winter.    Fig.  1537  represents  the  carriage  closed,  or 


1637 


wliat  is  termed  the  amempton,  which  can  be  readily  converted  into  a  step-piece  baronche. 
rig.  1538  13  the  carriage  thrown  completely  open,  and  constructed  as  an  ordinary  open 


1538 


carnage,  with  a  half  head,  which  is  raised  and  lowered  in  the  usual  manner,  with  a  soKd 
folding  knee  flap.  The  front  portion  of  the  amempton  is  formed  of  a  framework  with 
circular  front  glasses,  and  furnished  with  doors.  The  door  glasses  and  front  glasses  are 
made  to  rise  and  fall  at  pleasure,  and  are  furnished  with  silk  spring  curtains,  the  whole 
bemg  surniounted  or  covered  with  a  roof.  This  framework  is  secured  to  the  head  with 
a  new  kind  of  fastening;  the  door  glasses  when  down  are  received  into  the  lower  part 
of  the  doors;  the  back,  instead  of  being  flat,  is  of  a  curved  form 

WHETSLATE,  is  a  massive  mineral  of  a  greenish-gray  color ;  feebly  glimmering; 
fracture,  slaty  or  splintery;  fragments  tubular;  translucent  on  the  edges;  feels  rathl^ 
greasy;  and  has  a  spec  grav  of  2-722.  It  occurs  in  beds,  in  primitive  and  transition 
slates.  Very  fine  varieties  of  whetslate  are  brought  from  Turkey,  called  honestonet, 
which  are  in  much  esteem  for  sharpening  steel  instruments. 


•■rfmsm 


WHITE  LEAD. 


945 


WHEY  {Petit  laity  Fr. ;  Molken,  Germ.),  is  the  greenish-cray  liquor  which  exudes  from 
the  curd  of  milk.  Scheele  states,  that  when  a  pound  of  milk  is  mixed  with  a  spoonful  of 
proof  spirit,  and  allowed  to  become  sour,  the  whey  filtered  ofl;  at  the  end  of  a  month  or  a 
little  more,  is  a  good  vinegar,  devoid  of  lactic  acid. 

WHISKEY,  is  dilute  alcohol,  distilled  from  the  fermented  worts  of  malt  or  grains. 

WHITE  LEAD,  Carbonate  of  lead,  or  Ceruse.  (Blanc  de  plornb,  Fr. ;  Bleiweiss,  Germ.) 
This  preparation  is  the  only  one  in  general  use  for  painting  wood  and  the  plaster  walls  of 
apartments  white.  It  mixes  well  with  oil,  without  having  its  bright  color  impaired, 
spreads  easily  under  the  brush,  and  gives  a  uniform  coat  to  wood,  stone,  metal,  &c.  It 
is  employed  either  alone,  or  with  other  pigments,  to  serve  as  their  basis,  and  to  give  them 
body.  This  article  has  been  long  manufactured  with  much  success  at  Klagenfurth  in 
Carinlhia,  and  its  mode  of  preparation  has  been  lately  described  with  precision  by 
Marcel  de  Serres.  The  great  white-lead  establishments  at  Krems,  whence,  though 
mcorrectly,  the  terms  white  of  Kremnitz  became  current  on  the  continent,  have  been 
abandoned. 

1.  The  lead  comes  from  Bleyberg;  it  is  very  pure,  and  particularly  free  from  contami- 
nation with  iron,  a  point  essential  to  U'e  beauty  of  its  factitious  carbonate.  It  is  melted 
m  ordinary  p»4s  of  cast  iron,  and  cast  into  sheets  of  varying  thickness,  according  to  ihe 
pleasure  of  the  manufacturer.  These  sheets  are  made  by  pouring  the  melted  lead  upon 
an  iron  plate  placed  over  the  boiler;  and  whenever  the  surface  of  the  metal  begins  to 
consolidate,  the  plate  is  slightly  sloped  to  one  side,  so  as  to  run  off  the  still  liquid'^metal, 
and  leave  a  lead  sheet  of  the  desired  thinness.  It  is  then  lifted  off  like  a  sheet  of  paper; 
and  as  the  iron  plate  is  cooled  m  water,  several  hundred  weights  of  lead  can  he  readily 
cast  in  a  day.  In  certain  white-lead  works  these  sheets  are  one  twenty-fourth  of  an 
inch  thick  ;  in  others,  half  that  quantity ;  in  some,  one  of  these  sheets  takes  up  the  whole 
width  of  111 e  conversion-box;  in  others,  four  sheets  are  employed.  It  is  of  conse- 
quence not  to  smooth  down  the  faces  of  the  leaden  sheets ;  because  a  rough  surface  pre- 
sents more  points  of  contact,  and  is  more  readily  attacked  by  acid  vapors,  than  a  polish- 
ed one. 

2.  These  plates  are  now  placed  so  as  to  expose  an  extensive  surface  to  the  acid  fumes 
by  folding  each  other  over  a  square  slip  of  wood.     Being  suspended  by  their  middle,  like 
a  sheet  of  paper,  they  are  arranged  in  wooden  boxes,  from  4^  to  5  feet  long,  12  to  14 
inches  broad,  and  from  9  to  1 1  inches  deep.     The  hoxes  are  very  substantially  construct- 
ed ;  their  joints  being  mortised ;  and  whatever  nails  are  used  being  carefully  covered 
Their  bottom  is  made  tight  with  a  coat  of  pitch  about  an  inch  thick.     The  mouths  of  the 
boxes  are  luted  over  with  paper,  in  the  works  where  fermenting  horse-dung  is  employed 
as  the  means  of  procuring  heat,  to  prevent  the  sulphureted  and  phosphureted  hydro<'en 
from  injuring  the  purity  of  the  white  lead.     In  Carinlhia  it  was  formerly  the  practice 
as  also  m  Holland,  to  form  the  lead  sheets  into  spiral  rolls,  and  to  place  them  so  coiled 
up  in  the  chests;  but  this  plan  is  not  to  be  recommended,  because  these  rolls  -resent 
obviously  less  surface  to  the  action  of  the  vapors,  are  apt  to  fall  down  into  the  liquid  at 
the  bottom,  and  thus  to  impair  the  whiteness  of  the  lead.     The  lower  edges  of  the  sheets 
are  suspended  about  two  inches  and  a  half  from  the  bottom  of  the  box  T  and  they  must 
not  touch  either  one  another  or  its  sides,  for  fear  of  obstructing  the  vapors  in  the  first 
case,  or  of  injuring  the  color  in  the  second.     Before  introducing  the  lead,  a  peculiar  acid 
hquor  is  put  into  the  box,  which  diifers  in  diff-erent  works.     In  some,  the  proportions  are 
four  quarts  of  vinegar,  with  four  quarts  of  wine-lees ;  and  in  others,  a  mixture  is  made 
of  twenty  pounds  of  wine-lees,  with  eight  and  a  half  pounds  of  vinegar,  and  a  pound  of 
carbonate  of  potash.     It  is  evident  that  in  the  manufactories  where  no  carbonate  of  pot- 
ash is^employ^d  m  the  mixture,  and  no  dung  for  healing  the  boxes,  it  is  not  necessaryto 

3.  The  mixture  being  poured  into  the  boxes,  and  the  sheets  of  lead  suspended  within 
them,  they  are  carried  into  a  stove-room,  to  receive  the  requisite  heat  for  raising  round 
the  lead  the  corrosive  vapors,  and  thus  converting  it  into  carbonate.  This  apartment  is 
heated  generally  by  stoves^  is  about  9  feet  high,  30  feet  long,  and  24  feet  wide  or  of  such 
a  size  as  to  receive  about  90  boxes.    It  has  only  one  door 

The  heat  should  never  be  raised  above  86°  Fahr. ;  and  it  is  usually  kept  up  for  fifteen 
days,  m  which  time  the  operation  is,  for  the  most  part,  completed.  If  the  heat  be  too 
high  and  the  vapors  too  copious,  the  carbonic  acid  escapes  in  a  great  measure,  and  the 
metallic  lead,  less  acted  upon,  affords  a  much  smaller  product. 

When  the  process  is  well  managed,  as  much  carbonate  of  lead  is  obtained,  as  there 
was  employed  of  metal;  or,  for  300  pounds  of  lead,  300  of  ceruse  are  procured  besides  a 
certain  quantity  of  metal  after  the  crusts  are  removed,  which  is  returned  to  the  melting- 
pot.  The  mixture  introduced  into  the  boxes  serves  only  once;  and  if  carbonate  of  potash 
has  been  used,  the  residuary  matter  is  sold  to  the  hatters. 

4.  When  the  preceding  operation  is  supposed  to  be  complete,  the  sheets,  being  removed 
from  the  boxe-  sre  found  to  have  grown  a  quarter  of  an  inch  thick,  though  previously 


if -^ 


946 


WHITE  LEAD. 


I 


the  or    t    r  carbonate  of  lead  fo:tTonlL:^tL:::to7^^^^^ 

put  into  large  cisterns,  and  washed  very  clean.     The  cistern  is  ofVoormZlm 

?rom  In?  .r^'.^i^^''  bi^uneqna  height,  so  that  the  liquid  may  be  made  to  overflow 
fhr«I  i""  *'l  ^^^'''•.  ^"^"^^'  ^f  ^'^^  fi'^t  chest  is  too^full.  it^ecant3  its  exdss  int^ 
the  second,  and  so  on  in  succession.     See  Rinsing  Machine. 

IJie  water  poured  into  the  first  chest  passes  successively  into  the  other«  a  «l,VKf 

AfLi  t.  1^'  \!^'^\i^'  tfP^f  f  t],e  last  compartment  is  the  finest  and  light^^ 
After  tins  washing,  the  white  lead  receives  another,  in  large  vats,  where  it  is  nlwTvs 
kept  under  water.  It  ,s  lastly  lifted  out  in  the  state  of  a  liquid  piste  with  wold Jn 
spoons,  and  laid  on  drying-tables  to  prepare  it  for  the  market^        ^       '  ° 

llie  white  lead  of  the  last  compartn.ent  is  of  the  first  quality,  and  is  called  on  th« 
continent  silver  white.     It  is  employed  in  fine  painting.     ^        ^'  ^''^ 

l^nwr.-n  '^^^  "i"o'^  '"  '*1?^  quantities  with  ground  sulphate  of  barytes,  it  i. 

^nZa.  /  T'/m  ^'''"''""^  ^y  '''"  "^'"^  of  Venice  white.     Anothe7quality 
adulterated  with  double  its  weight  of  sulphate  of  barytes,  is  styled  Hamburgh^wh  te  * 
and  a  fourth,  having  three  parts  of  sulphate  to  one  of  white  lead,  gets  th? name  of 
Dutch  white.     When  the  sulphate  of  barytes  is  very  white,  like  that  of  the  Tyrol 
these  mixtures  are  reckoned  preferable  for  certain  kinds  of  painting,  as  the  barytca 
rsThutrsri^Jo^^farJrf  ^'  ""'  ^^"^^"  '''  '-'  from^ingsleedilfdaSS 

for  the  first  and  whitest  quality  was  mere  carbonate  of  lead.     The  freedom  from  sil v^r^ 
^e  lead  of  Vi! lach,  a  very  rare  circumstance,  is  one  cause  of  the  superbr  Hf   tlcar 
bonate;  as  wel   as  the  skilful  and  laborious  manner  in  which  it  is  washeTS  separal^ 
from  any  adhering  particle  of  metal  or  sulphuret.  separated 

•  Z'^^J^";^^"^'  lea'^  is  converted  into  carbonate  in  the  followin-  way  :— The  metal  is  cast 

CJ"  t""  ""{  "  ""''T'^  ^•■^^'"^'  '"  "°"'^^  '^^^"^  fi^»^^"  inches^^ne  and  fof  or  fivi 
bioad.  Several  rows  of  these  are  placed  over  cylindrical  glazed  earthen  pot.  Xut  four 
or  five  inches  m  diameter,  containing  some  treacle-vinegar,  which  are  then  c^^redwi"h 

St*  TrwholLrelr,^;'"'^"^^^  'V^l^'l^  and  so'insuccession?oaconvenTent 
Jieigm.  I  he  whole  are  imbedded  in  spent  bark  from  the  tan-pit,  brought  into  a  ferment 
mg  state  by  being  mixed  with  some  bark  used  in  a  previous  procesr^  Th"  l^s Tre  left 
Jindisturbed  under  the  influence  of  a  fermentin.^  temperature  for  eigh  or  n  ne^veek.  Tn 
the  course  of  tins  time  the  lead  gratings  become,  generally  speaking  converted  throu.^h° 
out  mto  a  solid  carbonate,  which  when  removed  is  levigated  in  a  proper  mill  and  elu^^^^^ 
ated  with  abundance  of  pure  water.  The  plan  of  inserting  coils  o?sreYle^d  ito  ear  hen! 
7Zt  TnH  iT:  ^«'?^^'"'"^7'"^S^'-'  ^"d  imbedding  the  pile  of  pipkins  in  fermenting  horse- 
dang  and  litter,  is  now  little  used  ;  because  the  coil  is  not  uniformly  acted  on  by  the  acid 
ra^IK^rs,  and  the  sulphureted  hydrogen  evolved  from  the  dung  is  apt' to  darken  \he  white 

In  the  above  processes,  the  conversion  of  lead  into  carbonate  seems  to  be  efiected  br 

acfdrVnd'hTnl'i  ""'''"'  '"  "  'T'^^  '"'"•^  atmosphere,  loaded  with  carbonic  and  acetic 
acids ,  and  hence  a  pure  vinegar  does  not  answer  well ;  but  one  which  is  suscentible  br 

operations.     M.  Thenard  first  established  the  principle,  and  MM.  BreLz  and  LeS 

^r  i^fifbVSrTorri^fd  tx-  "^'''-'^  -'^'--  subsequ^^reL^utd^r; 

c^ifrgnall-q:^^^ 

^nd  'hfn.'i:''/  ?  '""Vu'  ''f  ^'  '■'^"''■^'  ^«'-  "^^'^•'""  ^  neutral  acetate,  58  p^ndsTl  harge! 
wLh  Th/^n  '  f^'^A'""''!  '^''^  ''""''  ^^^^  quantity  of  base,  or  174  pounds,  mus 
^nn-?'  ,.^^^/«"^P«""^  \'  <J'>"ted  with  water  as  soon  as  it  is  formed,  and  bein?  decanted 
ofF  quite  hmpid,  is  exposed  to  a  current  of  carbonic  acid  gas,  which,  uniting  wiFh  the  two 
"r^i^y'T^'T  "^M'^^lf  f  '"^V"  '^'  subacetate,  precipitates  them  in^he  form  of  a 
Iv  hp  .vt  •  t^'iT  '''  '\^  r'^  ^r  "'^^  ^  ^^'"^*y  ^^^^"'°"s  ^<^^tate.  The  carbonTc  acid 
T^l  Lit  rTt  T  f  ^-^'^/i  ''\'''^''  compounds,  or  venerated  bv  combustion  of  cha  i- 
IZt'.tlln  .  K  ?'  T- '"  '^r  >'i'r  ^^^^>  it  must  be  transmitted  through  a  solution  cl 
acetate  of  lead  before  being  admitted  into  the  subacetate,  to  deprive  it  of  anv  particles  o 

wXettl^  do'w^t^^^^^    ^''''  l''  precipitation  of  the  car'bonate  of  lead  is  completed;Ld 
well  settled  down,  the  supernatant  acetate  is  decanted  off,  and  made  to  act  on  anithei 


WHITE  LEAD. 


947 


dose  of  litharge.  The  deposit  being  first  rinsed  with  a  little  water,  this  washing  is 
added  to  the  acetate;  after  which  the  white  lead  is  thoroughly  elutriated.  This  repe- 
tition of  the  process  may  be  indefinitely  made;  but  there  is  always  a  small  loss  of 
acetate,  which  must  be  repaired,  either  directly  or  by  adding  some  vinegar. 

In  order  to  obtain  the  nnest  white  lead  by  the  process  with  earthen  pots  containing 
vinegar   buried   in  fermenting   tan,   and   covered   by  a  grating  of  lead,  the   metal 
should  be  so  thin  as  to  be  entirely  convertible  into  carbonate;   for  whenever  any 
of  it  remains,  it  is  apt  to  give  a  gray  tint  to  the  product:    if  the  temperature  of  the 
fermenting  mass  is  less  than  90*^  Fahr.,  some  particles  of  the  metal  will  resist  the  action 
of  the  vinegar,  and  degrade  the  color;  and  if  it  exceeds  122°,  the  white  verges  into 
yellow,  in  consequence  of  some  carbonaceous  compound  being  developed  from  the 
principles  of  the  acetic  acid.     The  dung  and  tan  have  been  generally  supposed  to  act  in 
this  process  by  supplying  carbonic  acid,  the  result  of  their  fermentation ;  but  it  is  now  said 
that  this  explanation  is  inexact,  because  the  best  white  lead  can  be  obtained  by  the  entire 
exclusion  of  air  from  the  pots  in  which  the  carbonation  of  the  metal  is  carried  on. 
We  are  thence  led  to  conclude  that  the  lead  is  oxidized  at  the  expense  of  the  oxygen  of 
the  vinegar,  and  carbonated  by  the  agency  of  its  oxygen  and  carbon ;  the  hydrogen  of 
the  acid  being  left  to  associate  itself  with  the  remiining  oxygen  and  carbon,  so  as  to  con- 
stitute an  ethereous  cotnpoani:  thus,  supposing  the  three  atoms  of  oxvgen  to  form,  with 
one  of  lead  and  one  of  carban,  an  atom  of  carbonate,  then  tl"»e  remaining  three  atoms  of 
carbon  and  three  of  hydrogen  would  compose  oletiant  gas. 

It  is  customary  on  the  continent  to  mould  the  white  lead  into  coni<nl  loaves,  before 
sending  them  into  the  market.  This  is  done  by  stuffing  well-drained  white  lead  into 
unglazed  earthen  pots,  of  the  requisite  size  and  shape,  and  drying  it  to  a  solid  mass,  by 
exposing  these  pots  in  stove-rooms.  The  moulds  beirig  now  inverted  on  tables,  discharge 
their  contents,  which  then  receive  a  final  desiccation ;  and  are  afterwards  put  up  in  pale- 
blue  paper,  to  set  otf  the  white  color  by  contrast.  Nothing  in  all  the  while-lead  process 
is  so  injurious  as  this  pot  operation;  a  useless  step,  fortunately  unknown  in  Great  Britain. 
Neither  greasing  the  skin,  nor  wearing  thick  gloves,  can  protect  the  op?rators  from  the 
diseases  induced  by  the  poisonous  action  of  the  white  lead;  and  hence  they  must  be  soon 
seat  otf  to  some  othsr  depirtin^nt  of  the  work. 

It  his  been  supposed  that  the  differences  observed  between  the  ceruse  of  Clichy  and 
the  conraon  kinds,  depea  I  on  the  greater  compactness  of  the  particles  of  the  latter,  pro- 
duce I  by  their  slower  a:j:»rea:4tion ;  as  also,  according  to  M.  Robiquet,  on  the  former 
containin<^  considerably  less  carbonic  acid.     See  infrH. 

Mr.  Ham  proposed,  in  a  patent  dated  June,  1826,  to  produce  white  lead  with  the  aid  of 
the  fullowing  apparatus,  a,  a  {fig.  1539)  are  the  side-walls  of  a  store-room,  constructed  of 

bricks  ;  6,  is  the  floor  of  bricks  laid  in  Roman 
cement;  c,  c,  are  the  side-plates,  between 
which  and  the  walls,  a  quantity  of  refuse 
tanner's  bark,  or  other  suitable  vegetable 
matter,  is  to  be  introduced.  The  same  ma- 
terial is  to  be  put  also  into  the  lower  part 
at  d  (upon  a  false  bottom  of  grating  ?)  The 
tan  should  rise  to  a  considerable  height, 
and  have  a  series  of  strips  of  sheet  lead  g,  e,  e, 
placed  upon  it,  which  are  kept  apart  by 
blocks  or  some  other  convenient  means, 
with  a  space  open  at  one  end  of  the  plates, 
for  the  passage  of  the  vapors;  but  above 
the  upper  plates,  boards  are  placed,  and 

covered  with  tan,  to  confine  them  there.     In 

the  ower  part  of  the  chamber,  coils  of  steam-pipe/,/,  are  laid  in  different  directions  to 
distribute  heat ;  g,  is  a  funnel-pipe,  to  conduct  vinegar  into  the  lower  part  of  the  vessel ; 
and  A,  is  a  cock  to  draw  it  off,  when  the  operation  is  sus[)ended.  The  acid  vapors  raised 
by  the  heat,  pass  up  through  the  spent  bark,  and  on  coming  into  contact  with  the  sheets 
of  lead,  corrode  them.  The  quantity  of  acid  liquor  should  not  be  in  excess  ;  a  point  to 
be  ascertained  by  means  of  the  small  tube  t,  at  top,  which  is  intended  for  testing  it  by  the 
tongue,  k,  is  a  tube  for  inserting  a  thermometer,  to  watch  the  temperature,  which  should 
not  exceed  170°  Fahr.  I  am  not  aware  of  what  success  has  attended  this  patented  ar- 
rangement.    The  heat  prescribed  is  far  too  great. 

A  magnificent  factory  has  been  recently'  erected  at  West  Bromwich,  near  Birming- 
ham, to  work  a  patent  lately  granted  to  Messrs.  Gossage  and  Benson,  for  making  white 
lead  by  mixing  a  small  quantity  of  acetate  of  lead  in  solution  with  slightly  damped 
litharge,  contained  in  a  long  stone  trough,  and  passing  over  the  surface  of  the  trough 
currents  of  hot  carbonic  acid,  while  its  contents  are  powerfully  stirred  up  by  a  tra- 
velling-wheel mechanism.    The  product  is  afterwards  ground  and  elutriated,  as  usumJ< 


1539 


948 


WHITE  LEAD. 


1 

I 


la::rLtne\fwStVL7attad'^":eetn^  '^"^^    '  -  '«'^  that  40 

The  factory  has  since  proved  abortive  ^  ^       ''  "teraico-mcchanical  operations. 

Messrs.  Button  and  Dver  obt.iiin<.<1  n  n.t.„4     r 
by  transmitting  a  curren^t  of  pSd  carbonic  JidV.T?  "^\'''  °^\^^°^  ^^'^^  J^«<' 
through  a  mixture  of  litharge  and  nRrate  yio^/^l/    '5  the  combustion  of  cok^ 
which  is  kept  in  constant  a|itat"on  and  ebu"  ftn  t     f  ^  ""*^  ^^^'"^^^^  ^'^  water, 
perforated  coil  of  pipes  at  thel^oS  of  the  tub     -^^  introduced  through  . 

«pon  the  principle  of  Thenard'8  old  process^^^^^^  thTt hn  H"'"  ?^  ^'?^  ''  formed  her* 
forms  with  the  litharge  a  subnitrate^Xch  irforth  wiM,  t^^^^ '  ^"  >^'^  "^^""^te  of  lea* 
neutral  nitrate,  by  thi  agency  of  Jhe  cVrbon  c  add  JI  V^jnsformed  into  carbonate  anA 
of  white  lead  produced  by  precinUa^^^^^^  f     a    '^''-  ^^^^^^^^''ed  that  all  sortw 

dition ;  appear.^therefore,  sLfi^C  ^nL  Xn  y]Xd^  '"  •  ««'"^-<^^^«t«"'ne  con- 
cover  so  well  as  white  lead  made  by  lie  tnof.^  1^7'  ^'^^ J">croscope ;  and  do  not 

has  remained  always  solid  durinl  its  tranC'nn  f  ?u^^^\  ^""^  ^«"'  ^"  ^^'^^'  the  lead 
hence  consists  of  opaque  parSf        ''""'^''^^  ^^"^  ^he  blue  to  the  white  state;  and 

anto?h1:rfoTL\t^:£;^^:rbvriiJa't'''  ^^/^^^  ^,^P^'«^^  ^-^^-^ine  Torassa 
or  barrels.'  along  with^^ate;.  and  e/posin'  th^mLf^ "V' I'^T'*^  «''  «^-^>  '"  ^r^yi 
air,  to  be  oxidised  and  carbonate?^  It"?  said  ^w^^^  water  to  the 

expended  at  Chelsea,  by  a  joint  stock  comZ     :*„^f  "^^"'"^  "^  100.000/.  have  been 
the  nreceding  most  opilose'and  d:tuvT7oi; "-'J?^^  ^^  --"^ing 

tried  without  success  in  Germanv     T  amLn,,;       i  n    l!t  ^^  *'®^"'  ^""7  Jeara  ago. 
jects  for  preparing  white  lead  ar;  inferL^n  .  ^'^"^  *^/  ^^^^^  ^^  these^-ecent  p?o: 

old  Dutch   pWs^s   which  r^arb     so  ara^^^^^^^  q^^^ty  of  produce,  to^the 

thoroughly  into  the  best  white  lU.w  thin  £~  ^^  ^'"«  ^^^^ 

than  by  any  other  plan.  ^^^^  ^*^  ^^  ^«3'«>  at  less  expense  of  labor 

is  a''tt'^rb;>rat:'^Ie'i;{t!:.'tl?t::7„"l!'''  ?-t»tV-baoetate.  and  subnitrat, 
oxygon  8  and  one  of  csrboTJ'Sl^-^^llZ^^^,  IZ'TV^  !"'"'  '"*•  »"*  <>' 
compound;  or,  of  lead,  77-6-  oxvfen  «•  1,1  •  'o  *'  "'*  «'»""<=  height  of  the 
been  supposed,  by  so^;  auth'orftfat'  thi  de„r«„^'t' ,  '''=  '"  ^'^  P""^'  ''  h"' 
Krems  and  Holland  is  a  kind  of  subearbon-te  con^nin-        iT"'"^  *'""  '"''d  »' 

preparation  of  sulphate  of  leadfaTplS^^  Tit""'  ^"  ^^^^'"^^^'  ^839.  for  a 

bonate  is  applied.  His  plan  is  to  put  56  L  n/=  ^fl  i  *^.\P"'P««^«  to  which  the  car- 
with  one  pound  of  acetic  Lid  (and  water^n^r.-fi  ^''^-  ^'^^^'-^  '"^to  a  tub,  to  mix  it 
ture  till  the  oxide  of  lead  becomes  LLcetaL  "^  Bat  IT''^'  '  '^t^'  ^'^^  *«  ^^^^^te  the  mix- 
fected,  he  pours  into  the  tub,  t ^ra  pfDe  siifnhn^^  "^rV^''  "-^^"^^  ^«  P^tially  ef. 
the  rate  of  about  1  pound  per  m?nutP  Si  '  ^i  ^^  ^cidof  specific  gravity  1-5975,  at 
been  added  to  convert  aUthrie^d  into  T  .  n"^  't  T"^  ^"?:"^"3^  «^  ^^P^^^c  acid  has 
of  the  litharge.  The  sulnhate  if^ftor  !i  ^''''i^ !.  ^^'°=  «^°"t  20  parts  of  acid  to  1 12 
I  have  examined  {he  parties  of thYsThtrT^^^  "f  ^"^^>  «*«^^«  ^°^  the  market 
and  found  them  to  be  sem  ^crysUll  ne  nndJZf.  "'"'^  ^  good  achromatic  microscope 
carbonate.precipitated  from  sSine'tl^urns  ofThe  meTa?""^'  ^^'^  ""''  ^^^  ^"^^^^  '^ 

a  earion:rCmTs^oliL?or'tr^^^^^^^^  tKT^T^^^^  ^^^^  ^^  P-^P^tatin. 

ammonia.     On  this  process  in  »  ™         •  ,      •  the  metal  by  means  of  carbonate  of 

In  Liebig  ^n,w:e^:Xy:n:^:ZTM^^^^^^^^  »>e-dt 

investigation  of  two  sorts  of  lead  prepared  in  th'  n  /  k^'"^  ^t'  communicated  his 
vinegar  and  carbonic  acid  upon  metallic  IphH  ,ni  *?"^^  "^^^^  ^^  ^^^  «^«^^  action  of 
The  one  sort  was  manXt^rpTlJ^  '       u^""  *^^  ^^^*  ^^^^^^"ti 

He  also  examined  3  rpedmensoA  ^^  ^lagenfurth   of  xlemf  * 

position;  affording  Harper  cent  of  cSn'^  '^^^^^^  ^S'-eed  in  com 

ing  to   the   formula,   2  (PbOrco'Up^O    h'(^^^  correspond- 

carbonate  of  lead  with  1  atom  of  oxide  and  ?'  /    ^V  '''  '"  ^°"^^'   ^  atoms   of 
thus,¥3rmH-112-f-9.  ^  ''^°"'  of  water-in  round  numbers, 

Mulder  observed   specimens  of  whii*.  i^-^     r  j/». 
bonate,  oxide,  and  water/from  the  T^ve  if^' f  ^'A^rent  atomic  proportions  of  car. 
the  carbonate  increased.     The  whhe  lead  bv  thTnT'i  **^^'  '^^  ^""^'ty  improved  a. 
Blackett   of  Newcastle,  is  certaTniy  suSor  Is  «       ''^  P'^'T^        made  by  Messrs. 
Its  particles  are  amorphous  and  opaque  covering  oil  pigment  to  all  others. 

inthrrnSt^erj^^^^^^^^^^^ 

of  magnesia  in  water  impregnated  wi\h  carWc  "  Hd\'''''T^'  m  dissolving  carbonate 
limestone  or  other  earthy  substances  conSJirng  m^^nfS  IS' a^^^^^^^ 


WHITE  LEAD. 


949 


rough  hydrate  of  magnesia  in  the  mode  hereafter  described,  and  in  applying  this  solu- 
tion to  the  manufacture  of  magnesia  and  its  salts,  and  the  precipitation  of  carbonate 
of  lead  from  any  of  the  soluble  salts  of  lead,  but  particularly  the  chloride  of  lead;  in 
which  latter  case  the  carbonate  of  lead,  so  precipitated,  is  triturated  with  a  solution  of 
caustic  potash  or  soda,  by  which  a  small  quantity  of  chloride  of  lead  contained  in  it 
is  converted  into  hydrated  oxide  of  lead,  and  the  whole  rendered  similar  in  composition 
to  the  best  white  lead  of  commerce.    The  manner  in  which  these  improvements  are 
carried   into  effect   is  thus  described   by  the  patentee :  I  take  magnesian   limestone, 
\v1iich  is  well  known  to  be  a  mixture  of  carbonate  of  lime  and  carbonate  of  magnesia, 
in   proportions  varying  at  different  localities;  and  on   this  account  I  am  careful  tc 
procure  it  from  places  where  the  stone  is  rich  in  magnesia.     This  I  reduce  to  powder, 
and  sift  it  through  a  sieve  of  forty  or  fifty  apertures  to  the  linear  inch.    I  then  heat  it 
red  hot,  in  an  iron  retort  or  reverberatory  furnace,  for  two  or  three  hours,  when,  the 
carbonic  acid  being  expelled  from  the  carbonate  of  magnesia,  but  not  from  the  car- 
bonate of  lime,  I  withdraw  the  whole  from  the  retort  or  furnace,  and  suffer  it  to  cool. 
The  magnesia  contained  in  the  limestone  is  now  soluble  in  water  impregnated  with 
carbonic  acid  gas,  and  to  dissolve  it  I  proceed  as  follows :  I  am  provided  with  an  iron 
cylinder,  lined  with  lead,  which  may  be  of  any  convenient  size,  say  4  feet  long  by 
2^  feet  in  diameter ;  it  is  furnished  with  a  safety-valve  and  an  agitator,  which  latter 
may  be  an  axis  in  the  centre  of  the  cylinder,  with  arms  reaching  nearly  to  the  circum- 
ference, all  made  of  iron  and  covered  with  lead.     The  cylinder  is  placed  horizontally, 
and  one  extremity  of  this  axis  is  supported  within  it  by  a  proper  carriage,  the  other 
extremity  being  prolonged,  and  passing  through  a  stufling-box  at  the  other  end  of  the 
cylinder,  so  that  the  agitator  may  be  turned  round  by  applying  manual  or  other  power 
to  its  projecting  end.     A  pipe,  leading  from  a  force-pump,  is  connected  with  the  under 
side  of  the  cylinder,  through  which  carbonic  acid  gas  may  be  forced  from  a  gasometer 
in  communication  with  the  pump,  and  a  mercurial  gauge  is  attached,  to  show  at  all 
times  the   amount  of  pressure  within  the  cylinder,  independently  of  the  safety-valve. 
Into  a  cylinder  of  the  size  given  I  introduce  from  100  to  120  lbs.  of  the  calcined  lune- 
stone,  with  a  quantity  of  pure  water,  nearly  filling  the  cylinder ;  I  then  pump  in  car- 
bonic acid  gas,  constantly  turning  the  agitator,  and  forcing  in  more  and  more  gas,  till 
absorption  ceases,  under  a  pressure  of  five  atmospheres.     I  suffer  it  to  stand  in  this 
condition  three  or  four  hours,  and  then  run  off  the  contents  of  the  cvlinder  into  a 
cistern,  and  allow  it  to  settle.    The  clear  liquor  is  now  a  solution  of  carbonate  oi 
magnesia  in  water  impregnated  with  carbonic  acid  gas,  or,  as  I  shall  hereafler  call  it, 
a  solution  of  bicarbonate  of  magnesia,  having  a  specific  gravity  of  about  1*028,  and 
containing  about  1,600  grains  of  carbonate  of  magnesia  to  the  imperial  gallon. 

I  consider  it  the  best  mode  of  obtaining  a  solution  of  bicarbonate  of  magnesia  from 
magnesian  limestone,  to  operate  upon  the  limestone  after  being  calcined  at  a  red  heat 
in  the  way  described ;  but  the  process  may  be  varied  by  using  in  the  cylinder  the 
mixed  hydrates  of  lime  and  magnesia,  obtained  by  completely  burning  ma?nesian 
limestone  in  a  kiln,  as  commonly  practised,  and  slaking  it  with  water  in  the^  usual 
manner ;  or,  to  lessen  the  expenditure  of  carbonic  acid  gas,  the  mixed  hydrates  may 
be  exposed  to  the  air  a  few  weeks  till  the  lime  has  become  less  caustic  by  the  absorp- 
tion of  carbonic  acid  from  the  atmosphere.  Or  the  mixed  hydrates  may  be  treated 
with  water,  as  practised  by  some  manufacturers  of  Epsom  salts,  till  the  lime  is  wholly 
or  principally  removed ;  after  which  the  residual  rough  hydrate  of  magnesia  may  be 
acted  upon  in  the  cylinder,  as  described ;  or  hydrate  of  magnesia  may  be  prepared  for 
solution,  in  the  cylinder,  by  dissolving  magnesian  limestone  in  hydrochloric  acid,  and 
treating  the  solution,  or  a  solution  of  chloride  of  magnesium,  obtained  from  sea-water 
by  salt-makers  in  the  form  of  bittern,  with  its  equivalent  quantity  of  hydrate  of  lime,  or 
of  the  mixed  hydrates  of  lime  and  magnesia,  obtained  by  completely  burning  magnesian 
limestone,  and  slaking  it  as  above.  When  I  use  this  solution  of  bicarbonate  of  magnesia 
for  the  purpose  of  preparing  magnesia  and  its  salts,  I  evaporate  it  to  drjness,  by  which  a 
pure  carbonate  of  magnesia  is  at  once  obtained,  without  the  necessity  of  using  a  carbonated 
alkali,  as  in  the  old  process ;  and  from  this  I  prepare  pure  magnesia  by  calcination  in  the 
usual  manner ;  or,  instead  of  boiling  to  dryness,  I  merely  heat  the  solutcn  for  some  time 
to  the  boiling  point,  by  which  the  excess  of  carbonic  acid  is  partly  driven  off,  and  pure 
carbonate  of  magnesia  is  precipitated,  which  may  then  be  collected,  and  dried  in  the 
same  way  as  if  precipitated  by  a  carbonated  alkali.  If  I  require  sulphate  of  maimesia, 
I  neutralize  the  solution  of  bicarbonate  of  magnesia  with  sulphuric  acid,  boil  down, 
and  crystallize ;  or  I  mix  the  solution  with  its  e^ivalent  quantity  of  sulphate  of  iron, 
dissolved  m  water,  heated  to  the  boiling  point,  and  then  suffer  the  precipitated  car- 
bonate  of  iron  to  subside;  after  which  I  decant  the  clear  solution  of  sulphate  of  mag- 
nesia, boil  down,  and  crystallize  as  before.  When  using  this  solution  of  bicarbonate 
of  magnesia  for  the  purpose  of  preparing  carbonate  of  lead,  I  make  a  saturated  solution 
of  chloride  of  lead  m  water,  which,  at  the  temperature  of  50*  or  60»  Fahr.,  has  a  specifi- 


950 


WHITE  LEAD. 


dktdvDLiLatP?^Tt^^^^^^  when  carbonate  of  lead  is  imme- 

aiately  precipitated;  but  in  this  operation  I  find  it  necessary  to  use  certain  wecautiona 

T^rtZZ  ^  ^^r'^"'^^^"  ^'?^"''*5^  °^  '^^"""^^  «^  ^^^d  is  carried  down  a"onc.  wiUthe 
^^d   r.n;.n     /'^  precautions  are,  first,  to  use  an  excess  of  the  solutioh  of  mitnesil 
and  secondly  to  mix   the  two  solutions  together  as  rapidly  as  possible     Aslo  the 
first,  when  using  a  magnesian  solution,  containing  1,600  grs  VcaKate  of  maone^a 

r^^^^^r^V^.;""?'  ^^'^  ^  f.^"^^^'^  «^  ^^^""'i^  «^  ^^^^  saturated  at  550  or  erfahr 
1  measure  of  the  former  to  8|  of  the  latter  is  a  proper  proportion ;  in  which  case  thprp 

LIL'^^'T.  ""^  'f  ^'"f  ?  ^^  '^^^"^^^^  ^™P^«y^d>  amounting  to  about  an  eUTof  the 
Ota  quantity  contained  in  the  solution.    When  either  one  or  both  the  solutions  vlr^ 

preliminary  trials.  It  js  not,  however,  necessary  to  be  very  exact,  provided  thern  ii 
twTml  o^w'tf '"^"""'^   of  magnesia   amounting  to^froronTI^hl  to^^^^^ 

Su^  wm  rLirLc^';!'"^"^''''-  '^''^  ''.^'''  ''F''^'''  than  oSe  eighth  no 
T;  f7*i,  A        ^^P^  ^^^   unnecessan'  expenditure  of  the  magnesian   solution 

til  *^\'T"^  precaution,  of  mixing  the  two  solutions  rapidly  to|ethS  it  mav  be 
accomplished  variously;  but  I   have  found  it   a  good   method  to  run  them  S  two 

'r^Z^f'^'^'TiV'^l''''^  ^"  quantity,  into  a  small  cistern  Tn  which  they  are  to  Te 
rapidly  blended  together  by  brisk  stirring,  before   passing  out,  through  a  hole  In  the 

XZl  thn^  ^^kP-  'T^""  ^^  *""^'  ^^^^«  '^'  precipitate  finally  settles.    The  pre! 

if i  a  c^Jbonat  n?1  '',  '"  ^'  '''^\''''^'  ^^^^^^  ^"^  ^^^^^  ^^  ^^^  usual  manSS 
ilJL«T   ♦  ^  lead,  very  nearly    pure,  and  suitable  for  most  purposes:  but  it 

SJZf  t    T'""'  ^  «°^a»  portion  of  chloride  of  lead,  seldom  less  than  from  1  to  2 

Tthe  olo?%rbX  o'f  Th"'';r.  ".  'Vr''  ^  ^'^'^"^^^y^  ^^  somewhaJTnjirious 
it   into  TLa    .  A  ^'f  V^^,  "^l"'^^  ^^^*^-    ^  decompose  this  chloride,  and   convert 

of  caustic  aka^'ln'f 'n^ni  '-^  ''^  ^^^^'^^^  ]!»^  ^^  P-<^^Pitate  wiih  a  so'utfon 
Ip-.lwfth  .fi  ir  •  ""'"  ^'™'^^'"  ^'^  ^^^  ordmary  mill  used  in  grinding  white 
le-.d  with  oil,  adding  just  so  much  of  the  ley  as  may  be  required  to  convert  the  nip 

nf  wf  ilT'*'  ^  '''?  ^"''"-  ^  ^"°^  ^^'«  P^^te  to  lie  a  few  da?s,  after  whTch!  the  chlo?[de' 
formed  ^i"  th?'''' V'  "'  ^^TV^"-*'^^^^  decomposed,  I  wash  'out  the  alkal  ne  chlor  de 
whhe  le^d  l^^'''*^^'^"'  *^d  obtain  a  white  lead,  similar  in  composition  to  the  best 
I«     J        of  commerce     I  prepare  the  caustic  alkaline  ley  by  boiling  together  in  a 

the  sediment,  must  be  kept  in  a  close  vessel  for  use 

As  we  have  before  hinted,  the  manufiicture  of  white  lead  bv  the  Dutch  process  is  one 

the  nature  of  wh.ch  seems  yet  enveloped  in  considerable  obscurity.  So  far  asT^^^^^ 
go  the  action  wou  d  seem  to  consist;  first,  in  the  oxidation  of  metallic  lead  by ?he  atml 
sphere,  under  the  influence  of  the  vapor  of  acetic  acid;  secondlv.  in  thrpri^uction  o7 
acetate  of  lead,  by  the  combination  of  the  oxide  of  lead  w  th  the  acVticacid-  and  t  h-dlJ 
m  the  displacement  of  the  acetic  acid  from  its  union  with  the  ^xide  of  lead  by  th^^ 
action  of  carbonic  acid,  and  the  consequent  formation  of  white  lead  But  thisin  no  w^v 
accounts  for  the  fact,  that,  when  acetate  of  lead  is  decomposed  bj'trbonL  ac  d  it  Ca^ 
bonat^e  of  lead  and  not  white  lead,  which  is  formed.     Nor  can  we  conceive  how  ^ 

another  acid  incapable  of  completely  saturating  the  oxide.     In  other  worS^  L^wh"tf  I^ 

uoL  leinain  uimea  to  this  if  We  confess  our  inability  to  reconcile  the  facts  nf  tb^  n«<i^ 
w,  h  the  preceding  l.ypothesi,,  a„d  therefore  p„.«^on  to  rother  h,  whlc^,  we  wiU 
assume  that  aceta  e  of  lead,  but  not  the  nenfal  acetate,  is  formed  as  wl  havellrerdv 

White  ead.  On  Ins  view,  the  fir.t  actaon  in  a  white  lead  stack  would  be  the  production 
of  sex-b.isic  acetate  of  lead  ;  and  the  next  would  be  thp  Af>^tvnor,r!r:^ftu'..u  P"^**^"*^^'?" 
and  the  formation  of  whit^  lead.  "'^  '^''^'  "'^'*'"  ""^  ^^'^  ^^  eremacausis. 

The  apparatus  employed  in  the  manufacture  of  white  lead  is  extremely  simple  and 
consists  merely  of  certain  large  enclosures  or  spaces,  called  beds,  in  wS  t^he  sUcU  are 
bu.lt  up;  together  with  the  earthenware  pots  needed  for  holding  tWe  >regarand  the 


msi 


■Akrtk^Hata 


tfUi 


WHITE  LEAD. 


951 


machinery  used  in  casting  the  lead  and  grinding  the  white  lead,  so  as  to  fit  it  for  the 
market.  The  metallic  lead  was  formerly  used  in  the  shape  of  sheets  or  coils,  which 
were  placed  perpendicularly  over  the  vinegar  pots ;  but  this  practice  has  been  almost 
everywhere  abandoned,  and  at  present  the  lead  is  generally  cast  into  what  are  called 
"crates"  or  "grates,"  of  about  9  inches  square,  and  having  the  appearance  of  lattice* 
work;  the  object  being  to  expose  as  large  a  surface  as  possible  of  metallic  lead  to  the 
action  of  the  vapor  of  the  vinegar.  The  beds  are  of  considerable  size;  and,  in  this  re- 
spect, some  diversity  of  opinion  prevails  amongst  practical  men ;  but  it  seems  pretty 
certain  that  no  advantage  is  gained  when  the  area  of  a  bed  comes  to  exceed  300  square 
feet;  and  there  are  many  reasons  for  believing,  that,  with  beds  of  twice  this  area,  the 
gain,  in  point  of  diminished  labor,  is  much  more  than  compensated  for  by  the  reduced 
produce  in  white  lead.  Nevertheless,  each  manufacturer  seems  to  entertain  an  opinion 
of  his  own  in  respect  to  tliis  matter ;  and  there  are  even  some  pretensions  to  secresy 
concerning  it  In  fact,  everything  depends  upon  the  construction  of  the  bed,  for  it  is 
this  which  regulates  the  production  of  white  lead;  and  as  a  proof  of  the  great  im- 
portance connected  with  this  circumstance,  we  may  here  mention,  that,  \vhilst  one 
manufacturer  has  produced  as  much  as  65  per  cent,  of  corrosion  during  a  long  course 
of  years,  anoUier  in  his  immediate  neighborhood  has  never  been  abled  to  exceed  52  per 
cent  The  beds  of  the  former  are  16  feet  square,  whilst  those  of  the  latter  are  19|  feet 
square;  and,  in  dwelling  upon  the  details  of  this  operation,  we  shall  find  tliat  theo- 
retically, a  bed  may  be  tx>o  large,  as  the  above  practical  fact  indicates.  Similarly  it 
can  be  shown  that  a  stack  (which  is  merely  a  series  of  beds)  may  be  too  large;  and  ex- 

Seri^-nce  has  convinced  us  that  a  stack  containing  more  than  eight  beds  is  to  be  con- 
emned  ;  and,  as  a  general  rule,  six  should  be  preferred,  except  where  want  of  space 
renders  a  different  line  of  manufacture  indispensable. 

In  forming  a  stack,  it  is  necessary  to  begin  by  laying,  in  the  first  instance,  a  bed  of 
spent  tanner's  bark,  3  feet  in  thickness,  over  the  surface  of  the  bed ;  and  upon  this  are 
placed  the  eartlienware  pots  containing  the  vinegar.  These  are  arranged,  side  by  side, 
and  filled  to  about  one-third  of  their  contents  with  vinegar,  of  a  strength  equal  to  6  per 
cent  of  anhydrous  acetate  acid.  Upon  these  pots  are  placed  the  crates  of  lead,  and  over 
all  a  series  of  boards  are  arranged,  which  form  a  floor  for  the  next  layer  of  spent  tan.* 
Such  an  arrangement  as  we  have  described,  is  denominated  "a  bed,"  but  there  is  this 
difference  between  the  beds,  viz.,  that  the  lowest  or  bottom  bed  has  a  bed  of  tan  3  feet 
in  thickness,  whereas  but  1  foot  is  needed  in  the  others.  Having  finished  the  lowest 
bed,  12  inches  of  spent  tan  are  now  placed  upon  the  bo-^rds,  and  a  similar  arrangement 
of  pots,  crates,  and  boards,  takes  place,  which  constitutes  the  second  bed;  this  is  fol- 
lowed by  a  third,  a  fourth,  and  so  on,  until  at  last  the  uppermost  bed  is  finished  ;  when 
a  layer  of  spent  tan,  30  inches  in  thickness,  is  placed  over  the  whole,  and  the  operation 
may  be  said  to  commence.  In  six  or  eight  days  the  tan  begins  to  ferment  and  evolve 
heat;  and  this  goes  on  increasing  for  some  weeks,  when  it  gradually  diminislies,  and 
at  the  end  of  about  three  months  the  whole  has  become  cool,  and  the  stack  is  fit  to  be 
taken  down.  When  examined,  the  pots,  which  formerly  contained  vinegar,  will  now 
be  found  to  be  quite  empty,  or  to  hold  a  little  water  merely,  but  no  acetic  acid;  the 
leaden  crates  will  be  discovered  to  have  increased  sensibly  in  bulk,  to  have  become 
coated  with  a  thick  and  dense  incrustation  of  white  lead,  and  in  some  places  even  to 
have  become  altogether  converted  into  this  substance ;  w^hilst  the  tan,  having  lost  its 
fermentative  quality,  is  now  useless,  except  for  fuel. 

The  successive  beds  constituting  the  entire  stack  are  next  carefully  removed,  so  as  to 
obtain  the  white  lead  with  the  least  possible  admixture  of  the  tan;  and  as  a  portion  of 
this  substance  always  adheres  to  the  crates,  these  are  washed  in  a  kind  of  wear  or  trough, 
by  which  the  whole  of  the  tan  is  thoroughly  separated.  When  this  is  seen  to  be  com- 
plete, the  corroded  part  of  the  plat^  or  "white  lead"  is  detached  from  the  uncorroded 
or  "blue  lead,"  by  means  of  slight  taps  or  blows  with  a  mallet  The  blue  lead  is 
weighed,  and,  for  the  most  part,  remelted  and  again  cast  into  crates;  whilst  the  white 
lead  is  first  crushed,  and  afterwards  ground  in  wat^r  into  a  fine  powder,  when  it  is  col- 
lected by  elutriation  and  deposition,  and  dried  in  stoves,  a  little  below  the  boiling  heat 
of  water.  Formerly  this  grinding  was  performed  in  the  dry  way,  and  much  injury  to 
the  health  of  the  workmen  thus  resulted;  but,  during  the  last  20  years,  the  wet  mode 
of  grinding  has  become  general,  and  is  greatly  to  be  preferred. 

The  conversion  of  white  lead  into  paint  is  a  simple  mechanical  operation,  though,  as 
we  have  before  remarked,  it  is  followed  by  chemical  results;  for  there  can  be  no  doubt 
that  the  surplus  oxide  in  the  white  lead  combines  with  part  of  the  oil  employed  to  form 
the  paint,  and  gives  rise  to  a  true  plaster  or  metallic  soap.  The  proportions  of  oil  and 
white  lead  vary  with  different  manufacturers;  nor  does  it  matter  much  what  these 
proportions  are:  the  principal  point  is  to  obtain  a  thorough  intermixture  of  the  two 
ingredients;  and  this  is  done  by  grinding  them  together  beneath  heavy  stones  or 
"  runners,"  for  several  hou»-s,  at  the  end  of  which  time  the  mixture  wUl  be  found 
oomogeuoua 


T 


952 


WINDLASSES. 


The  most  probable  explanation  is  cerUiin  v  tl^i?  no  sal.ent  feature  to  guide  our  inquirf 
pre-existence  of  sex-basic  acetate  of  [e^d  ^1  tL«l"''  r^"'  f"^  ^'"^^^  supposes  tb^ 
which  prove  that  this  substance  is  canabie  nfnn  ^^  *V™^  ^''^''^  «'*  "<>  experiments 
to  complete  the  argument  But  then  thL  i^s  n  "/n"  T'?F  ^^"  ^'^^  ^^ombustion^reS 
sohuion;  and  there  are  many  LaWour/aerf^^^^^^ 

eremacausis  or  combustion  heVe  hintfnf  Ta  ^'''^'"^f^^y  ^hat  warrant  the  kind  of 
atom  of  the  sex-basic  acetate  of  ead  and  eitu  r'""'^"^  '^"'^  ^^  be  correct,  th„  one 
unite  as  in  the  following  diac^ram  and  nrod!,./f  "' ?^  atmospheric  oxygen,  wouM 
atoms  ofwater.twoatom^sof^whl^Lwlf;^^^^^^^^^^ 

consisfa  /\f 


WINES. 


953 


sex-basic 
1  -i  acetate 
of  lead 


i 


consists  of 
6  oxide  of  lead 
4  earlon 
3  hydrogen 
3  oxygen 

8  oxygen 


2  hydrated  basic 
carbonate  of  lead 
or  white  lead 


4  carbonic  acid. 


:sf  "F'X '"^^""'■^'•-^^  kind  oT IL^eato  of  lead, 

under  the  influence  of  a  gentle  hpn/  K?/        ..       *  ^'^''  "  '"''^e  excess  of  litharge  oan 
,    Connected  with  this  siS  is  th«  K^^/"^, /'»"«/<>" verted  into  white  lead      ^  '      "' 
lead  or  oxychloride,  which^  s  nov.  eont^f^^^^^  "''''^'  """'^  '^''  «ub  cM,,;^,  ^f 

oxychloride  is  so  constituted.  tTaTJ^for  fw"^:,"'"  as  a  substitute  for  white  lead      The 
we  substitute  two  atoms  of  c'hloride  oM^nTn        '  f  ^"'"bonate  of  lead  in  white  lead 
which  has  been  made  the  sub  l^'o   :Utenttv  Mr"  H"p^^^  ^'"  "^^^  eompound.  and 
T^ne.     Xow  ,t  is  a  very  remarkable  flfand  .JonJw    '  ^«"'"««'».  of  Ne  wcastle-upon- 
we  have  here  advanced,  that  the  nerpkfnt  "cov^6^  corroborative  of  the  views  which 
lead,  just  as  its  basic  composition  woi^d  fn  l«f ^  ^  T""^  '''^"  ^'^h  the  best  white 
of  Jead  contained  in  it  uniTes  to  pm  of  th.  In  V.k  "^  ^^'  probability  is,  that  the  oxide 
Boap ;  whilst  the  chloride  of  lead  remains  in         ^'  ^1"'"^'  ^^^''"'"^  ««  before  a  meta  lie 
opacty  and  whiteness.     An  observaTonUl"^:^^ '"  '''''  T":  ^"^  eommuni cat  . 
Ure.  shows  the  correctness  of  such  a  conclut^An    f      7f'  '"  ^^^  ^''^  '"«tance  by  Dr 
chloride  of  lead  be  quite  insoluble  in  wate'vI?aV.?;'  S''^""^^'  ^''^"  «J«°-.  ^heUy 
readi  y  dissolves  from  the  mass  the  chbr  Je  ohII      "^/"'^ture  with  oil,  boiling  watfr 

^at  paint  made  with  an  insoluble  salt,  like  carboLln'^^'*"^'  '"""^^  "'«<>  *«  «bow. 
with  a  soluble  salt,  like  the  chloride     Exoprlpn?       ^^"^' ''  P'-^^'erable  to  one  madi 

cotton  threads,  which  b/ctpilfary  alL'on  drawTm^fhr-,'  "'r"^  '"^^^  ^^  ^o^  «P"n 
W,  or  wax  in  candles,  in  small  successive  port  on!  fn7  'I  ^"'"'1^''  °^  ^be  melted  tal- 
and  tallow  candles,  the  wick  is  formed  o^parX  X'i^  ^  ^''T'^'  ^"  «^"^"^'>"  wax 
Wick  isp  aited  upon  the  braiding  machrnp'^ml'!f  "T^'^V  ">  the  stearine  candles  the 
and  dried,  whereby,  as  it  burnsjt  fait  to  or.rr'^'"'''' "  ^^''^^"^ 

l".r^fK  '"  '^^  P«^^"^  ««ndl  so  Mr  Palmer  on'pf  T^r^  ^'^^-'^  requiring  ^ 
With  subnitrate  of  bismuth  ground  ud  wiVh  ^f'^      *t"^,^  ""^  ^be  wick  is  first  imbLd 

tTi:r;r"^?  ^•-i>%;  anf^rthis^wrci  tw  Lv  he'i'^^'n'' v'^?  '^^"^^  rounJTn  td 

twisted  double  round  a  rod,  like  the  Z^.2^.^^lfxr  ^^"^^b  of  the  intended  candle  la 
inserted  in  the  axis  of  the  eandle  moujd  Ts^K^^^^r  ™^  ^''^  ^^tb  its  c^il  bein  ' 
low;  and  when  the  tallow  is  set  tL  J.^' '  .  u^  enclosed  by  pouring  in  the  melted  fT 
U.e  candle.  As  this  candTeL  burned  the  end,  %^m  ^5  ''t  ^'  ^«P'  braving  tS^Bw^k^" 
beyond  the  flame;  and  the  bisSh  attachpd  f  I  "''  ^^"^^"  "^'^^  ^^and  out  siJewava 
T?^  't  «^™««Pbere,  causes  the  wic  "tote  co'l'tT'''"  ^'*"^  «^^^^  ^"  by  the  oxy! 
'^'wr'ei'H^^  ^^  «""ffi"^  it-  completely  consumed,  and,  therefore  s^vei, 

WIXCING-MACHINE   is  iha  v    v  x. 

horizontaUy   by  the  endtontTLf  fx;:^n  Crfn^^^^     ^^^^?  '^^^'  ^bich  he  suspends 
the  hue  of  the  axis,  being  placed  ovp^fj,        .  ?I  "^S^'  ^^er  the  edge  of  his  vat  sTt^of 
the  pie«e  of  cloth  ^hich  fs  Cunl  Ton  the  rl':     '  ^''''T  '"^  ^bfcoppe     w  i ',  t^rmi 
partment  of  the  bath,  according  as  i^  turned  bv^  descend  alternatel/fnto  ei &„ 

having  the  windlass  upset     With  this  mr.K;  ^^^  'bip  without  the  possibilitv  nf 


beam,  polygonal  in  transverse  section,  acting  horizontally  at  right  angles  to  a  line  bi- 
secting the  ship  from  stem  to  stern,  and  working  in,  and  bearing  upon,  stancheons, 
called  "knight-heads,"  strongly  fixed  to  the  ship's  deck  and  deck-timbers  immediately 
abaft  the  foremast  The  use  of  the  windlass  is  to  raise  or  weigh  the  anchor,  by  means 
of  the  cable,  which  is  made  to  take  a  turn  round  the  windlass  beam,  whose  spindle  shape 
enables  it  to  present  itself  at  right  angles  to  a  line  drawn  from  either  hawshole,  under 
which  the  anchor  may  lie,  for  the  ship  is  hove  short  upon  her  anchor  by  means  of  the 
more  quickly  moving,  but  less  powerful  capstan,  before  the  windlass  is  called  into  action. 
The  "purchase"  of  a  windlass  is  the  power  applicable  to  work  it,  or  rather  the  means 
provided,  as  the  handspike  levers  in  ordinary  use,  of  applying  the  power  of  the  men  to 
turn  the  beam,  and  wind  or  hoist  up  the  anchor  by  its  cable.  Nothing  can  exceed  the 
simplicity  or  strength  of  the  ordinary  ship's  windlass,  having  regard  to  the  size  and 
strength  of  the  ship  herself:  but  there  is  room  for  improvement  in  the  power  and  in  the 
speed  of  a  windlass,  and  the  means  of  doing  the  same  work  with  fewer  hands  would  be 
a  great  advantage. 

A^INE,  is  the  fermented  juice  of  the  grape.  In  the  more  southern  states  of  Europe, 
the  grapes,  being  more  saccharine,  aflbrd  a  more  abundant  production  of  alcohol,  and 
slronajer  wines,  as  exemplified  in  the  best  port,  sherry,  and  madeira.  The  influence 
of  solar  heat  upon  the  vines  may,  however,  be  mitigated  by  growing  them  to  moderate 
heights  on  level  ground,  and  by  training  them  in  festoons  under  the  shelter  of  trees. 
In  the  more  temperate  climates,  such  as  the  district  of  Burgundy,  the  finer  flavored 
wines  are  produced ;  and  there  the  vines  are  usually  grown  upon  hilly  slopes  front- 
ins  the  south,  with  more  or  less  of  an  easterly  or  westerly  direction,  as  on  the  Cote 
d'Or,  at  a  distance  from  marshes,  forests,  and  rivers,  whose  vapors  might  deteriorate 
the  air.  The  plains  of  this  district,  even  when  possessing  a  similar  or  analogous 
soil,  do  not  produce  wines  of  so  agreeable  a  flavor.  The  influence  of  temperature  be- 
comes very  manifest  in  countries  furiher  north,  where,  in  consequence  of  a  few  de- 
grees of  thermometric  depression,  the  production  of  generous  agreeable  wine  becomes 
impossible. 

The  land  most  favorable  to  the  vine  is  light,  easily  permeable  to  water,  but  some- 
what retentive  by  its  composition ;  with  a  sandy  subsoil,  to  allow  the  excess  of  moisture 
10  drain  readily  ofl".  Calcareous  soils  produce  the  highly  esteemed  wines  of  the  Cote 
d'Or  ;  a  s;ranite  debris  forms  the  foundations  of  the  lands  where  the  Hermitage  wines 
are  grown ;  silicious  soil  interspersed  with  flints  furnishes  the  celebrated  wines  of 
Chateau-Nv,uf,  Ferte,  and  La  Gaude ;  schistose  districts  aflTord  also  good  wine,  as  that 
called  la  Malgue.  Thus  we  see  that  lands  difl'ering  in  chemical  composition,  but 
possesse  1  of  the  proper  physical  qualities,  may  produce  most  agreeable  wines ;  and  so 
also  may  lands  of  like  chemical  and  physical  constitution  produce  various  kinds  of 
wme,  according  to  their  varied  exposure.  As  a  striking  example  of  these  effects,  we 
may  adduce  the  slopes  of  the  hills  which  grow  the  wines  of  Montrachet.  The  insulated 
,>art  towards  the  top  furnishes  the  wine  called  Chevalier  Montrachet^  which  is  less 
esteern«;d,  and  sells  at  a  much  lower  price,  than  the  delicious  wine  grown  on  the  middle 
height,  called  true  Montrachet.  Beneath  this  district,  and  in  the  surrounding  plains. 
Che  vines  aflford  a  far  inferior  article,  called  bastard  Montrachet.  The  opposite  side  of 
the  hills  produces  very  indilfereni  wine.  Similar  differences,  in  a  greater  or  less  degree, 
are  observable  relatively  to  the  districts  which  grow  thePomard,  Volnay,  Beaune,  Nuits. 
Vougeol,  Chamberlin,  Romance,  &c.  Everywhere  it  is  found,  that  the  reverse  side  01 
the  hill,  the  summit,  and  the  plain,  although  generally  consisting  of  like  soil,  afford  infe- 
rior wine  to  the  middle  southern  slopes. 

Amelioration  of  the  soil. — When  the  vine  lands  are  too  light  or  too  dense,  they  may 
be  modified,  within  certain  limits,  by  introducing  into  them  either  argillaceous  or  sili- 
cious matter.  Marl  is  excellent  for  almost  all  grounds  which  are  not  previously  too 
calcareous,  being  alike  useful  to  open  dense  soils,  and  to  render  porous  ones  more  reten- 
tive. 

Manure. — Fcr  the  vine,  as  well  as  all  cultivated  plants,  a  manure  supplying  azotized 
or  animal  nutriment  may  be  used  with  great  advantage,  provided  care  be  taken  to 
ripen  it  by  previous  ferinenlalion,  so  that  it  may  not,  by  absorption  in  too  crude  a 
state,  impart  any  disagreeable  odor  to  the  grape;  as  sometimes  happens  to  the  vines 
grown  in  the  vicinity  of  great  towns,  like  Paris,  and  near  Argenteuil.  There  is  a  com- 
post used  in  France,  called  animalized  ft/ac/f,  of  which  from  one  fifth  to  one  half  of  a  litre 
(old  En^:lish  quart)  serves  sufficiently  to  fertilize  the  root  of  one  vine,  when  applied  every 
year,  or  two  years.  An  excess  of  manure,  in  rainy  seasons  especially,  has  the  effect  of 
rendering  the  grapes  large  and  insipid. 

The  ground  is  tilled  at  the  same  time  as  the  manure  is  applied,  towards  the  month  of 
March;  the  plants  are  then  dressed,  and  the  props  are  inserted.  The  weakness  of  the 
plants  renders  this  practice  useful;  but  in  some  southern  districts,  the  stem  of  the  vine, 
when  supported  at  a  proper  height,  acpuires  after  a  while  sufficient  size  and  strength  to 


===3= 


i  'I 


i 


954 


WINES. 


the  spring  rains  hare  washed  it  down      Thl  r.  •     "    ,  ^^  ^'^^^^^^  over  with  soiJ  aft^r 

repealed  after  maceialin"  the  J»iU>  "^«»'''"?.  "Peralion  beains,  which  is  nsS 
has  softened  the  texture  of  the  sS  1,1  .k""?''  "■'""'  "■""»  «"  "'=  Pie  "t  Lmentaill^ 
grapes  are  collected  i^  the  va,  ,he    „ice  h-?    '""  ''<■'"•    ^^^"^  '"«  whole  bS 

M  s.h-n'^V"  ^""^^  "Wtoas,  were  the  mo»  hs  «?  .h.f'"' '"  ""*  '"Pi  '>'"  ''  »'ou|<| 
M.  Sebille  Attger  introduced  with  ^ucces,  hT.^L  ,■    u""'  "?''  ■=<""«••     With  this  view 
wtrT'"'  "'■"'"  Maine-et-Loire  '^""  """"  '"  ">«  ■""""fecture  of  wineTa 

«  it  eea«st;Tttm'ltuo"„fS"he''wif  "'"'"'■■""  ""'^  »•"«  >««»  'e.ula,ed  as  soon 
be  racked  off  from  the  lees"  by  means  oH V  "",'  ""I'"''''  ^-'-^h^rine  or'muddy' "S 
marc  being  then  gently  scueeLn  In  .  -'l"?"'.  an<l  run  into  the  ripenin-  tunV    Thi 

tributed  among  th^e  tuns  iS  eq„:i  pronoS/^ht.,"  "i'-^"""^  -^'^^  ^"whiSh  isit 
in  U,rS''i°^  "■«  casKs\"f1„S  w^n":  •  ■""  '"^  ^"-  "^'--d  by  stronge;;?j:: 

.he  m„st  beingl^rc:LV'fnl!r?cl7enTTvS"-  T^^'^  '"  ''-'^.  »"  --unt  of 
a  temperature  of  about  65=  or  68°  P    i^.U  ^      "  ■"="  ^'""eracted  by  maintaining 

mis  concentration  be  inconvpm'pnf  »        *«i™ent  is  at  the  same  t  me  deslrovwl      «Jh«»i  i 
mediately  after  racing  it  o^"''  '  '^'^""^  ^^^^^'^^'^  °^«»o^ar  must  be  [nTle^  Ti*! 

happens  particularly  in  the  south  of  FrL^^^^^^  ?^^^"/«  Wgh  as  1-1283.     tS 

the  specihc  gravity  varies  from  1-050  to  hfion         5r  i"  ['^^  °^  ^^^^  ^^cker  in  Germanv 
«  varies  much  in  diflerent  ye^rs.  ^^^'  '"  ^^idelberg,  frcm  1-039,  to  l-O^l     buf 

Atter  the  fermentation   is  comnlete    ih.  ,- 

.hereLX  at'  ^IwaTs'^K'T^  Ye?'"^"'^  '"",^-'"«"^  »  whole  cask  of  wine  and 

~ey  are  rip,  but  are  left  Mr^  ^  0-^^47:1---^^^^^^^ 

In  general  the  whole  vintage  of  thp  r?«v  •  .  ^ 

must  is  received  in  separate  vats      A,  ,?  ''  ^^'^''^^  ''»  ^^^  evening,  and  the  resulting 
ture  be  above  50°  F    and  !f  ,hn  t'  u '^  '^"'^  "''"^^'y  of  6  or  8  hoursif  i  h!  ["^'"'^'"^ 

or  scum   is  forLd  affhe  surf'c7^4h'r  "^^I'^^"  ^°°  <=«'J   ^vhen 'j  fu  I'ed  "S 
acquires  such  a  consistence  as  to'^^^^^^^^^  -creases  in    thickCs^    '^J.e^^^ 

and  drained;   and  the  thin  Jiqno    L    "tu^ed  10^!^' "  ^' ^^'^^^  ^^^ 

S  ma? h  "'  ''?'  f  ^"'•'"^^'  which      "removed '•:  iIl'I*     ^  '^^  ^^^^  ^^^^rward, 
iniia  may  be  produced.     The  re<»ular  v.nn„c  r  •  ^  "tanner,  and  somejines  • 

by  air-bubbles  rising  up  the  side^if  the  Ives  ^^hh"'"''"^^  begins,  cha^acterTzeS 

«;  ^e  su'(ace.  At  this  period  all  the  rem^  n, '  r  .?  ^l*'"''^''  ^hizzin?  as  they  break 
and  the  clear  subjacent  must  be  t lansST  "!.  ^■^^\^'^"^^^  ^^  quickly  skimmed  off 
regular  fermentation.  "anslerred  into  barrels,  where  it  is  left  to  ripen  by  « 


WINES. 


955 


grapes.    The  tannin,  while  it  tends  to  preserve  the  wines,  renders  them  also  more  easj 
to  clarify,  by  the  addition  of  white  of  egg,  or  isinglasSb 

The  white  wines  should  be  racked  off  as  soon  as  the  first  frosts  have  made  them  clear, 
and  at  the  latest  by  the  end  of  the  February  moon.  By  thus  separating  the  wine  from 
.he  lees,  we  avoid,  or  render  of  little  consequence,  the  fermentation  which  takes  place  on 
the  return  of  spring,  and  which,  if  too  brisk,  would  destroy  all  its  sweetness,  by  decom* 
posing  the  remaining  portion  of  sugar. 

The  characteristic  odor  possessed  by  all  wines,  in  a  greater  or  less  degree,  is  pro- 
duced by  a  peculiar  substance,  which  possesses  the  characters  of  an  essential  oil.  As  it 
is  not  volatile,  it  cannot  be  confounded  with  the  aroma  of  wine.  When  large  quan- 
lities  of  wine  are  distilled,  an  oily  substance  is  obtained  towards  the  end  of  the  oper- 
ation. This  may  also  be  procured  from  the  wine  lees  which  are  deposited  in  the 
casks  after  the  fermentation  lias  commenced.  It  forms  one  forty  thousandth  part  of  the 
wine ;  and  consists  of  a  peculiar  new  acid,  and  ether,  each  of  which  has  been  called  the 
ananthic.  The  acid  is  analogous  to  the  fatty  acids,  and  the  ether  is  liquid,  but  insoluble 
in  water.  The  acid  is  perfectly  white  when  pure,  of  the  consistence  of  butter  at  60°, 
melts  with  a  moderate  heat,  reddens  litmus,  and  dissolves  in  caustic  and  carbonated  alka- 
lis, as  well  as  in  alcohol  and  ether.  (Enanthic  ether  is  colorless,  has  an  extremely  strong 
smell  of  wine,  which  is  almost  intoxicating  when  inhaled,  and  a  powerful  disagreeable 
taste.     Liehig  and  Pelouze. 

Sparkling  wines. — In  the  manufacture  of  these,  black  grapes  of  the  first  quality  arc 
usually  employed,  especially  those  gathered  upon  the  vine  called  by  the  French  noh-ien, 
cultivated  on  the  best  exposures.  As  it  is  important,  however,  to  prevent  the  coloring- 
matter  of  the  skin  from  entering  into  the  wine,  the  juice  should  be  squeezed  as  gently  and 
rapidly  as  possible.  The  liquor  obtained  by  a  second  and  third  pressing  is  reserved  for 
inferior  wines,  on  account  of  the  reddish  tint  which  it  acquires.  The  marc  is  then  mixed 
with  the  grapes  of  the  red-wine  vats. 

The  above  nearly  colorless  must  is  immediately  poured  into  tuns  or  casks,  till  about 
three  fourths  of  their  capacity  are  filled,  when  fermentation  soon  begins.  This  is  allowed 
to  continue  under  the  control  of  the  elastic  bung,  above  mentioned,  for  about  15  days, 
and  then  three  fourths  of  the  casks  are  filled  up  with  wine  from  the  rest.  The  casks  are 
now  closed  by  a  bung  secured  with  a  piece  of  hoop  iron  nailed  to  two  contiguous  staves. 
The  casks  should  be  made  of  new  wood,  but  not  of  oak — though  old  white  wine  casks 
are  occasionally  used. 

In  the  month  of  January  the  clear  wine  is  racked  off,  and  is  fined  by  a  small  quan- 
tity of  ising-glass  dissolved  in  old  wine  of  the  same  kind.  Forty  days  afterwards  a 
second  fining  is  required.  Sometimes  a  third  may  be  useful,  if  the  lees  be  considerable. 
In  the  month  of  May  the  clear  wine  is  drawn  off  into  bottles,  taking  care  to  add  to 
each  of  them  a  small  measure  of  what  is  called  liquor^  which  is  merely  about  3  per  cent. 
of  a  sirup  made  by  dissolving  sugar-candy  in  white  wine.  The  bottles  being  filled, 
and  their  corks  secured  by  packthread  and  wire,  they  are  laid  on  their  sides,  in  this 
month,  with  their  mouths  sloping  downwards  at  an  angle  of  about  twenty  degrees,  io 
order  that  any  cediment  may  fall  into  the  neck.  At  the  end  of  8  or  10  days,  the  inclina- 
tion of  the  bottles  is  increased,  when  they  are  slightly  tapped,  and  placed  in  a  vertical 
position ;  so  that  after  the  lees  are  all  collected  in  the  neck,  the  cork  is  partially  removed 
for  an  instant,  to  allow  the  sediment  to  be  expelled  by  the  pressure  of  the  gas.  If  the 
wine  be  still  muddy  in  the  bottles,  along  with  a  new  dose  of  liquor,  a  small  quantity  of 
fining  should  be  added  to  each,  and  the  bottles  should  be  placed  again  in  the  inverted 
position.  At  the  end  of  2  or  3  months,  the  sediment  collected  over  the  cork  is  dexte- 
rously discharged ;  and  if  the  wine  be  still  deficient  in  transparency,  the  same  process  of 
fining  must  be  repeated. 

Sparkling  wine  {vin  mousxeux),  prepared  as  above  described,  is  fit  for  drinking  usually 
at  the  end  of  from  18  to  30  months,  according  to  the  slate  of  the  seasons.  It  is  in 
Champagne  that  the  lightest,  most  transparent,  and  most  highly  flavored  wines  have 
been  hiiheito  made.  The  breakage  of  the  bottles  in  these  sparkling  wines  amounts 
frequently  to  thirty  per  cent.,  a  circumstance  which  adds  greatly  to  their  cost  of  pro- 
duction. 

Weak  wines  of  bad  growths  ought  to  be  consumed  within  12  or  15  months  after  being 
manufactured;  and  should  be  kept  meanwhile  in  cool  cellars.  White  wmtis  of  middling 
strength  ouiiht  to  be  kept  in  casks  constantly  full,  and  carefully  excluded  from  contact 
of  ail.  ind  the  racking  off  should  be  done  as  quickly  as  possible.  As  the  most  of  them 
are  injured  by  too  much  fermentation,  this  process  should  be  so  regulated  as  always  to 
leave  a  little  sugar  undecomposed.  It  is  useful  to  counteract  the  absorption  of  oxygen, 
and  the  consequent  tendency  to  acidity,  by  burning  a  sulphur  match  in  the  casks  into 
which  they  .are  about  to  be  run.  This  is  done  by  hookins:  the  match  to  a  bent  wire,  kindling 
and  suspending  it  within  the  cask  through  the  bung-hole.  Immediately  on  withdrawing 
the  match,  the  cask   should   be  corked,  if  the  wine  be  not  ready  for  transfer.      II 


956 


WINES. 


^"l^p.:^  i:^t Sft^jt- K"^,  j^^-<>  tHe  casl.  .  .  a  proof  of  th. 

uniform  temperature  in  summer  aadwter    and  biaTsLh^Tn"^  ''  V""'''''  «*»-«••'' 
highway  or  street  as  not  to  suffer  vibration  from  ..         f-^  a  distance  from  a  frequented 
Wines  should  be  racked  off  in  ^Ini         .k    ^.'''^  "'*'^"'"  o^carria-es.  ^        ^ 

for  light  wines.     St."n"s  ^r^^^^^^^  off^ml^'^h^'"^^^  'f^^^  ^^^  «»-» time 

months  upon  the  lees,  to  promote  the'  slow  ort,ensihl7r  "^^  '^"^^  ^  ^'^^^  ^'^  ^'?»»teen 
managed  serves  beiter  than  a  faucet  to  draVoff  wrnf  ll'T'^^''^^"'  ^  ^>'P^«"  ^^e" 
wines,  before  being  bottled,  should  be  fined  wi^hi.Tn".!  ^T  '-^^  s^^i^^ent.  White 
with  whites  of  eggs  beat  um  into  a  n-nt h  !n  i  •  '^'"":"Jass ;  red  wines  are  usually  fined 
water.     But  sonTe^trong  wine  ^  ^h  e tare"a  iTtlLl  ^'^^^  ^j'"^^  '"^^^  ^""^  «? 

sho^w{f  :Si;t^^^^^  "^  ^^^^^'^  ^^*"^^^  <ieteriorations,  to  which  remedies 

rn^iZll  l^Si^^;:^:^^^:;?-- fe  n  .  a  violent  ^rmentative  move- 
these  have  been  tightly  clo 'ed  U?e  iiter ior  ZIZ  ^'^"  ?"""  °^'  '"^o  the  casks.  If 
as  to  burst  the  hoops,  or  cause  the  lams  7f  thH'  ""^^  ""^''^'^  '^  «"<=h  «  degree 
bungs  already  described  will  prevent  rebnVt^^n/o^'.t"''  l"'^'  k°  ^P^'^"  '^'^^  ^^^^^ic 
done  to  repress  the  fermentation  le"t  it  .ho.  d /l^L  .,  '"''u'^f '  ^"^  something  must  be 
the  wine  unpalatably  harsh!    One  -emefyf  to  tr3^  ''^  '^"  '""^^'^  «"^  "^^ke 

fumigated  with  burning  sulphur"  another  ?  to  add  n'[r  k  ""^  '"^^  '^'^  previously 
sulphite  of  lime;  and  a  third  and  nerhan/t  fl  1  r  ?  "^  ^  ?^°"^  °"«  thousandth  part  of 
tard-seed  into  e^ch  barrel  At lu'v  ate  the  vWn?s%hnH  I^k'I"^'  *^^^'^  P«""^  '^"«s- 
ments  are  allayed,  to  remove  the  floauLVrernT;^^^^^^^^^^^^^ 

orii;:Sl7tooTt^^^^^^^^  wine  is  a  proof  of  its  containing 

or  to  too  high  a  temperatu  e  in  the  ieflar  Th.  he.t  ti  •^''^.  V\^  ^''^  ^'^  '^  vibrations^ 
mix  It  with  its  bulk  of  a  stronger  wine  in  a  IpV,  -,5  T^  ^°  ^^  ^°"^  ^»  ^''i''  case  is,  to 

bottle  it,  and  to  consume  it  L^  soln  as  poss7b l  r"'.'"^  T''  ^°  ^"^  ^^^  '"''^ture;  to 
w.ne  This  rft./.,„;.,,  i„  wines  fZerlyCe  rise  t/hVv  "7"'  "'"^^  ^  ^°°^  ^^^Pi"? 
ing  litharge  as  a  sweetener;  whereby  a  n'uanti^vn;''J^'  J''^  dangerous  practice  of  add- 
in.  the  liquor,  productive  of  the  2st  deTeSi^f  on         ""^  was  formed 

of  It.  In  France,  the  regulatiLTf  pote  and  Z'"Tr'  'J"  '^"^^  ^^«  ^'^^^ 
council  of  salubrity,  have  comDletelvnnt^'  .?•  ^^^  enlightened  surveillance  of  the 
acid  by  lime  and  ot'hW  alkairetasls  ha  teZ^TZ"'  T''{  /'^^  ^^^"^^^^«»  ^^  t^e 
or  less  the  vinous  flavor  and  taste.  S^^^rally  a  prejudicial  effect,  and  injures  more 

Mopmess  or  viscidity  of  wines.— The  cau^o  nfthio    i, 
for  drinking,  was  altoUher  unknown  tUl  M   F,^n  P^.^"°^'^^"°"' ^hich  renders  wine  unfil 
slrated  that  it  was  owin^  to  an  Sed  matted    .i^i''  ""^  «l>°t^^.cary  of  Nantes,  demon- 
fact  it  is  the  white  wines,  especially   hose  wS  con  ^^^i;'  '^  ^'^"''^'^^  (^^"^^»)     «nd  in 
ject  to  this  malady.     He'  also  poin  ed  out  tT^n  oTr  ^I'^T  ^''>''  V«""'">  w'^'<=''  «re  sub- 
under  a  rather  agreeable  form,  nan:ely,  U.e  bruhTh..  ri?     >\/"  '^^  "^^'^^«"  «^  ^«»«i*-» 
in  a  somewhat  unripe  state ;  of  which'in    po  ^tel^^^i^S^^^  n'i"^'"^'"-'^^?  ^'""''''^^ 
After  agitation,  the  wine  is  to  be  left  in  reLe  for  «  di  '  ,        '     sufficient  for  a  barrel. 
The  tannin  by  this  time  will  have  separated  ihp„Lf-      ,-'   "'   •'^°'  ^"d  t^^en  racked  off. 
moved  , he  ropiness.     The  wine  il  to^'b^red 'rndTS  oil""  '^^"  ^'^  "^""^>  ^^  - 

^«3r^LS?:tSSt^!;:i^  ^-^  --^  -i-  had  re. 

:ii:^:d  ^;s  ^i^rihii^-^^  eausj  of  t  rr  i^st::'^^;^-!;.  f  r  s 

Accordin?  to  a  statement  in  the  Dirfinnttni^^  'r    i     7     . 
hectare  of  vineyard,  upon  tl/e  averagf  rnryTa^fl^^^^^^^  ^"""^^  P^^-^  ^^  a 

litres,  which  fetch  0-877  francs  each,  or  200  fraJcs  .L  .'  r'noo  ^  °^  ^^^"«>''  ^^  ^779 

all  to  1672  francs.  Deducting  for  expenses  and  Mv!/^°^.^^.^  ^•^'^^'  amounting  in 
remain  1,100  francs  of  net  proceeds  tand  as  thev-^'-  ^7'"'^^^^^*^  ^'^  ''^^ncs,  there 
23,000  francs,  the  profit  tuJns  out  ti  be  no'no^e  than%  n''  '"''''"' "^^^  ^^  ^''^^^'^  at 
the  growths  of  Beaune,  Nuits,  &c.,  does  not  excet  600  7  ''"''  \^"  "^'  ^''^^^^^^  ^« 
and  therefore  is  equivalent  to  only  2h  per  cent   unn^.n     ^'^-"'f  ^^'  ^^^^are  (2-4  acres). 

The  quantity  of  alcohol  contained  inTfferem  wines  l^?!;""'*      ,     k         ' 
borate  experiments  by  Brande  and  FontenelleV  but  as  i   r^n^"  T'^'/^'  '"^'J"*^^  «'' ^^«- 

,  out  as  It  must  evidently  vary  with  difler- 


WINES. 


957 


ent  seasons,  the  results  can  be  received  merely  as  approximate.  The  only  apparatus 
required  for  this  research  is  a  small  still  and  refrigeratory,  so  well  fitted  up  as  to  permit 
none  of  the  spirituous  vapors  to  be  dissipated.  The  distilled  liquor  should  be  received  in 
a  glass  tube,  graduated  into  one  hundred  measures,  of  such  capacity  as  to  contain  the 
whole  of  the  alcohol  which  the  given  measure  of  wine  employed  is  capable  of  yielding. 
In  the  successive  experiments,  the  quantity  of  wine  used,  and  of  spirit  distilled  over,  be- 
ing the  same  in  volume,  the  relative  densities  of  the  latter  will  show  at  once  the  relative 
stren^tlis  of  the  wines.  A  very  neat  small  apparatus  has  been  contrived  for  the  purpose 
of  analyzing  wines  in  this  manner,  by  M.  Gay  Lussac.  It  is  constructed,  and  sold  at  a 
moderate  price,  by  M.  Collardeau,  No.  56",  Rue  Faubourg  St.  Martin,  Paris.  The  pro- 
portion given  by  Brande  (Table  I.),  has  been  reduced  to  the  standard  of  absolute  alcohol 
by  Fesser;  and*  that  by  Fontenelle  (Table  II.),  to  the  same  standard  by  Schubarthj  ai 
in  the  following  tables : — 

Table  I. 


Name  of  the  wine. 


Port  Wine, 

Port  Wine, 

Mean, 

Madeira 

Madeira, 

Sherry, 

Sherrj- 

Bordeaux,  Claret,  . . . 
Bordeaux,  Claret,  . . . 

Ca1ca\'ella, 

Lisbon, 

Malaofa, 

Bucellas, 

Red  Madeira, 

Malmsey, 

Marsala, 

Mareala, 

Champagne,  [rose],. . 
Champagne,  [white], 

Burgundy, 

Burgundy, 

White  Hermitage,.. . 

Red  Hermitage, 

H«ck, 

Hock 

Vin  de  Grave 


100  measures 

Sp.  grav. 

contain  at  00°  F. 

Alcohol 

Absolute 

of  0-825. 

alcohol. 

0-97616 

21-40 

19-82 

0-97200 

2583 

2392 

0-97460 

23  49 

21  75 

0-97810 

1934 

1791 

097333 

21-42 

22-61 

0-97913 

18-25 

17-00 

0-97700 

1983 

18-37 

0-97410 

12-9! 

11-95 

0-97092 

16  32 

15-11 

0-97920 

18  10 

16-76 

0-97846 

18-94 

1745 

0  98000 

17-26 

15-98 

0-97690 

18-49 

17-22 

0-97899 

18-40 

17-04 

0-98090 

1640 

15-91 

0-98190 

15-26 

14-31 

0-98000 

17-26 

15-98 

0-98608 

11  30 

1046 

0-98450 

12-80 

11-84 

0-98300 

14-53 

13-34 

0-98540 

11-95 

HOG 

C-9799C 

1743 

16-14 

'3-9S495 

12-32 

11-40 

0-98290 

14-37 

1331 

0-98873 

8-68 

800 

0-9S450 

12fc0 

1184 

Name  of  the  wine. 


Frontignac, 

Cote-Roti, 

Roussillun 

Cape  Madeira, 

iTi uscai .  ••.•»•«•. 9. ... 

Constantia, 

Tinto 

Schiraz, 

Syracuse, 

Nice, 

M.  OlLo  Vf   ■■•  ••••  •••••••• 

Raisin  Wine, 

Drained  grape  Wine,.. 
Lachryniae  Cliristi,  . . . . 

Currant  Wine, 

Gooseberry  Wine, 

Elder  Wine, \ 

Cider, .,.,.  > 

Perry, ) 

Brown  Stout, 

^V16f  ••■•••••••••••«••• 

I  oin6i f  •••  ■•••  ••••••  •■ 

Rum, 

Hollands, 

Scotch  Whiskey 

Irish  Whiskey, 


Sp.  grav, 


0-98452 
0-9S495 
0-98005 
0-97924 
0-97913 
0-97770 
0  98399 
0-98176 
0-98200 
0-98263 
0-98760 
0-97205 
0-97925 

0-97696 
0-9S550 

0-98760 

0  98116 
0-98873 

0-93454 
0-93855 


100  measures 
contain  at  60°  F. 


Alcohol 
of  0-825. 

17-79 
12-27 
1724 
1811 

Absolute 
alcohol. 


16-25 
19-75 
13-30 
1552 
15-28 
14-63 
9-88 
25-77 
18-11 
19  70 
20-55 
11-84 

9-87 

6-SO 

fees 

4-20 
5368 
51-60 
54-32 
53  90 


1184 
11-36 
15-96 
16-77 
17-00 
1829 
12  32 
1435 
14  15 
1364 
915 
23  86 
16-77 
18  24 
1903 
1096 

914 

6-30 

6-00 

3«!9 

4971 

47-77 
50  20 
4991 


Table  II. 

Name  of  the  Wine. 

Absolute 
alcohol. 

Name  of  the  Wine. 

Absolute 
alcohol. 

Name  of  the  Wine. 

Absolute 
alcohol. 

Routnllon  {Eastern 

Pyrenees.) 
Rive-saltes  18  yrs.  old 
BanvuUs      18        » 
Collyouvre  15        " 
Salces          10        " 

Department  of  the 
Aude. 
Fitoa  and  Lcu- 

catg  10  yrs.  old 
1  Lapalme      10        " 

9-156 
9-2-23 

9080 

8-680 

8-568 
8-790 

Sijeau            8  yrs.  old 
Narbonne      8        " 
Lezignan     10        " 
Mirepeisset  10       " 
Carcasonne   8        " 

Department  of  VHe- 

rault. 
Nissau           9        " 
neziers          8        " 
Montagnac  10        " 
Meze            10        " 

8035 
8-379 
8-173 
8-589 
7-190 

7-896 
7-728 
8-108 
7-812 

Montpellier    5  yrs.  old 
Lunel              8        " 
Frontignan     5        " 
Red  Hermitage  4    " 
White     do. 
Burgundy       4        '• 
Grave               3        " 
Champagne  (sparkling) 

Do.  white      do. 

Do.  rose 
Bordeaux 
Toulouse 

7413 
7-564 
7-098 
6-838 
7  056 
6-195 
5-638 
5-680 
5145 
4-956 
6-186 
5027 

WINES.  In  a  case  tried  before  the  Court  of  Exchequer,  at  the  instance  of  the 
Board  of  Customs,  in  December,  1843,  of  an  attempt  to  obtain  the  drawback  upon  a 
large  quantity  of  damaged  claret  offered  for  exportation,  I  had  observed,  in  my  examin- 
ation of  the  wine,  that  on  the  addition  to  it  of  water  of  ammonia  to  supersaturate  its 
acidity,  a  lai^e  flocculent  precipitate  of  decomposed  gluten  fell,  and  the  supernatant 
liquor  lost  its  ruby  color,  and  became  yellow-brown.  I  have  tried  sound  samples  of 
genuine  claret,  very  old,  as  well  as  new,  by  the  same  test,  and  I  have  found  the  ruby 
color  to  remain  but  little  impaired ;  contrary  to  the  allegation  oi  the  chemist  of  the 


958 


WINES. 


forfeited  to  the  Crown.  ^  °  admitted  for  drawback,  and  therefore 

ii^'J^SlZ,  "^^1^:^^-  ^'  '''''  ^-^P-  (-«-)  or  from 
langunge  of  the  Excise,  imder  wS  .,mpt?fS  ^^t  "^'"^^  «»•«  ««^'ed  *«r^i,  in  the 
the  duties  upon  them  ^e,^  replied  asC^ro'st^the  VV^'^P^'*^^^  '^'  1834,  when 
revenue.  The  raisins  called  Lexiai  are  saTtonrod.'^' "S^  unproductive  to  the 
Denias  a  sweet  wine-  the  Rln/^t  ir^  s^'^ /<>  produce  a  drj  flavored  wine-  thfl 
andValeneias  a  Hch  Td  f^    tine  'yhe%?r ^^^^^^^^^  the  red  Sm^rt' 

the  wine  manufacture.  The  m^se^'of  rlL  ^  T  -"^  ""P"^^"  «'«  ^^«  Attest  time  for 
either  beaten  with  mallets  or  crS./l/'  ^^  bemg  taken  out  of  the  packagca.  Z 
then  steeped  in  water  in  far'e  vats  ttw  In  l^?r^^^°^  ^  ^««-"  t^m.^d^r! 

at  top.  The  water  being  after  some  time  drawn  off^K  ^T^  ".'  *^^"om  and  another 
sure  IS  applied  to  the  upper  board  to  extract  Xh  V  1^^""  "°^  '"^^""^^  ^^"'^  Pre^ 
down  through  the  false  bottom,  and  flows  oVLan'l"^^'  '^'''  "?""''''  which  passes 
tuns.  'The  residuary  fruit  is  infused  T.Ta^I-r^  i  ^PP^^P^-^^te  pipe  into  fermenting 
cess  which  is  repeated  till  all  ?hp!l        «<^^'t'?nal  water,  and  then  squeezed-  a  m^ 

jected  to  severe^retr"  fn^a^'srw^or^  Ty.t^f.^l'^:'^^^^^  ^^'  "-P<^'''  ^^-^ 
the  vmous  fermentation  is  occasionnllv  L=LJf?      ^i  ^**®  ^*°^'  >^  the  process  of 

p>rove  its  flavor,  and  also  trmS  t'^^P?;;!'^^^^^^^^^^^  ^^f[-t  body  of  the  ra^pe  to  im 
Pm.JA.^^^''^^'  «^«'''fi^d  by  being  repeated  vrT.^'ff       aT'.'^  ?'  afterwards  set  to 
.  WINES,   DEACIDIFICATICKV  OF     liL  ""  '  *°'^.  ^°^^  ^'^'^  isinglass. 

Liebig*  p«M|,hed  in  his^^n  for*  te  March  .^^^^^J /'.'""ar  tiSe.  Professor 
that  ^^^uable  object  on  old  stored  J?fal/w.M  pf?'^  i^.n  mitlel)  for  effecting 
wines,"  he  says,  "even  of  the  mZtJT^l-^^l^  ^^'""®  ^'"««-  "Most  of  these 
tain  a  certain  quanti;  of  free  SrarK^'I^LT^^^^  "°^  ^"^  '*^^  ^^^^  condition,  con 
properties  depend  T^ie  iuicp  nf  llf  ^'''^•  ^^  ^ho8«  presence  many  of  their  essential 
that  of  those  of  the  youni Toots  n  Ta  ""^  ^'^^^'  ^^'^^^'"^  bitartr^te  of  potasT  and 
of  these  sorts  of  grapes  %ecom'  erme'n .0^^?  '\ T'^'J"^  ^'''^'  ^^  ^he^n  th  'must 
portionally  as  the  alcohol  increases   a^fan^^  diminishes  in  solubility  pro! 

deposit  of  tartar  increases  dtiringtL  first  year  of  1 '"'  .!  ""^  V'^  '^'  ^^^^^  ^W« 
becoming  encrusted  more  and  more  w^th  ils  crvll  '  "^^  ^^'  ^^''  ''^''  *'^  ^^'  ^*«^'» 
addition  of  the  new  wine  to  reXe^^at  of  tK  ^-Ji"- T'T^""^  ^f  the  continual 

thereby  acqVire\  a   a^"e^\a?^  S^oTr^L' ."r ''^T.^^^J^^^^^^^  tarSc S? and 
deposited  tartar.    In  the  8toHn|of  many  of  th^^^^^^^^^  ^T^'^  "^  re-dissolving  the 

at  a  certain  period.     By  progfe^ivTfimnl  nn  fh      '"^"^\f^^«  '«rtar  again  disappears 

augment^  the  taste  and'^iaUfTthe  ^  i'e^^^faLr^^^^^^^^^^    '^^^  proportiSSally 
^me  less  af^reeablp  in  11=0      a      l  ^         exalted,  but  the  acid  contents  makp  th^ 

mean  of  t^&:gt7riretZlZ: ^^a  wXtfir  "'"?""  "•ereforrweict::': 
of  the  wme.     This  mean  is  Dure  nlnfr^f  ...     altering  in  any  respect  the  quality 
centrated  solution,  is  added  tHnph^fl  -^    ''^''  ""{  P^^^^'     "^^^^  *'»«  «alt,  ?n  con 
soluble  tartar  (one  Dart  of  wh.-K  -^"'"J  as  the  above,  there  results  the  sparinZ 

temperature  foH^  ai)thf^^^^^^^^^^  ^«,  ^00  parts  of  water  IZTnU'y 

as  bitartrate  from  the  liquid     If  we  add  to  10^^^^^^^^^  '  °^"^r«^««i<^  «"<!  «eparates 

of  free  tartaric  acid  one  and  ^hZf  ^  *  #•  P  f*  ®^  '^  ^^^^  ^hich  contains  one  Dart 
rate  by  rest  at  180~190  c  two  1.1^  f  ^^"^"//^^  ^^rtrate  of  potash,  there  wil  s?^. 
one  half  part  of  tartar  diSord^rn'v  TT^^^^'^^  ^^^^^  ^"^  ^^«  ^^^ue  contains  now 
acid.  In' this  case.  0  8  oUhe  frl;...^  .  ^k"'"  "'? ,*^"'^  ^^  P«rt8  of  the  origind  freT 
Such  is  the  Professor's  statement^?  bave  been  withdrawn  ffom  the  wine."^  ' 

proved  that  the  sourness  of'o  d  ratt:d  w  nereUher'oVt^  'T^''  ^"^  "^^  ^^«  ^^^t 
proceeded  from  excess  of  tartaric  acid  h'!^^J  /,  }^^  ^'""«  ^^  «ther  vintages, 

genious.  In  the  London  Dock,  amon;  h.  ^"  "^^u  ^^  ^"  ^^"«"j^  ^^^^l  as  it  isin. 
wine  there  stored  up,  numbers  ;enZVom  ZZ  '"^'"''"^  P'^^^  '""^  ^^g^^eads  of 
8our  as  to  be  hardly  potable.  Samp  «;  of  Tuoh T.  '  ^^^''^^'^.^tances,  till  the/become  so 
me  for  analysis  and  amelioration^  Mv  first  o^^  ^^^^  been  brought  t^ 

nature  of  the  acidity.     That  point  wfZ  ^  "'^''^  "^^^  ^«  ascertain  the  amount  and 

test  alkaline  solutio^  thit  warsl^r^rb^'^fv''^  "^^"^^^^  ^^  *^«  P^^P^S  o7a 
port.on  of  it  being  distilled  nearly  odrynL  Z'.VT''^^ ^^  '^-^  ^'"«  -^"o^he? 
temperature  of  about  235°  Fahr    the  whnlfn.    •     ^^!  ^^*^  ^^  «  ^^<l"id  bath,  at  the 

*  See  PAarw.  Jburn.,  page  90. 


■'^m 


WINE. 


959 


water,  filtered,  and  tested  by  Liebig's  plan,  with  a  concentrated  solution  of  neutral  tar- 
trate of  potash,  but  no  precipitate  of  bitartrate  ensued,  proving  that  no  free  tartaric 
acid  was  present  In  fact,  during  the  slow  fermentation  of  old  vatted  wines,  much  of 
the  alcohol  and  of  the  saccharine  matter,  with  the  whole  of  the  easily  decomposed  free 
tartaric  acid,  seems  to  be  acetified,  which  accounts  for  the  lai^e  proportion  of  vinegar 
obtained  in  the  distillation  of  such  wines.  When  a  little  of  that  distilled  liquor  is  re- 
stored to  Ihe  filtered  solution  of  the  residuum,  the  mixture  acquires  the  property  of  de- 
composing neutral  tartrate  of  potash,  just  as  pure  vinegar,  or  malic  acid  does,  by  seizing 
a  portion  of  the  potash,  and  favoring  the  formation  and  precipitation  of  the  bitartrate. 
In  fact,  the  feeblest  free  acid  is  adequate  to  produce  this  result,  on  the  great  principle 
which  forms  the  ground-work  of  Berthollet's  Chemical  Statics,  a  work  too  little  studied 
by  the  modern  race  of  chemists.  If  to  the  acidulous  wines  in  the  London  Docks  (the 
veritable  alte  ahgelagerte  of  Liebig)  solution  of  tartrate  of  potash  be  added  as  long  as  any 
precipitate  of  tartar  takes  place,  much  of  the  neutral  salt  is  required,  and  of  course  much 
acetate  of  potash  is  formed,  which  being  very  soluble  remains  in  the  wine,  and  vitiates 
its  taste.  From  these  facts,  which  any  one  may  easily  verify,  it  appears  to  me  that  the 
Professor's  Mittel  zur  entsduemng  alter  ahgelagerter  Rheinweine  is  of  no  practical  use. 
If  the  recent  must  contains  a  hurtful  excess  of  free  tartaric  acid,  it  may  no  doubt  be 
got  rid  of  by  his  method. 

I  found  that  one  part  of  bitartrate  of  potash  is  soluble  in  151  parts  of  water  at  65° 
Fahr.  (about  18^  C.)  instead  of  in  180  to  200  as  he  stated.  The  specific  gravity  of  the 
solution  is  10034. — Pharmaceutical  Journal^  vol.  viii.  No.  2. 

WINES,  RHINR 


Place  of  Growth. 

Sort  of 
Grapes. 

Specific 
Gravity. 

100  parts  yielded. 

Absolute 
Alcohol. 

Dry 

Residue. 

Steinberg 
Riidesheim 
Marksbrunn     - 
Gersenheim 
Dirnheim 

Weinbeim  Hulberg- 
Worms,  Liebfrauenmileh 

Bingen,  Scharlachberg 

Eisler,  Kleimberger 
Wiesbaden       -         -    ) 
Neroberg        -        -    J 
Wiesloch 

Riesling 
Orleans 
Riesling 

•                       * 

1-0025 
1-0025 
0-9985 
0-9936 
0-9925 
0-9925 
0-9930 
j  not  deter-  ) 
mined     j 

0-9950 
0-9945 

10-87 
12-65 
11-60 
12-60 
9-84 
11-70 
10-62 

12-10 

11-90 

10-83 

9-83 

9-94 
6-39 
5-10 
8-05 
2-18 
2-18 
2-27 
not  deter- ) 
mined     J 

2-78 
2-48 

From  the  known  prices  of  these  wines,  it  is  obvious  that  the  proportion  of  alcohol, 
although  one  factor  in  determining  the  value  of  a  wine,  is  not  the  only  absolute  one, 
nor  does  it  stand  in  any  fixed  relation  to  the  commercial  value  of  the  wine.  It  is  re- 
markable that  the  finest  sorts  of  wine  contain  a  much  greater  proportion  of  solid  sub- 
stances in  solution  than  the  inferior  sorts;  and  that  the  weight  of  the  residue,  which 
the  Rhenish  wines  yield  on  evaporation,  ofi^ers  a  safer  criterion  for  determining  their 
commercial  value,  than  the  proportion  of  alcohol.  These  solids  disguise  the  acid,  take 
off  the  acrid  taste,  and  at  the  same  time  impart  body,  mellowness,  arul  oiliness.  Among 
the  extractive  matters  of  new  wines  are  sugar,  which  gradually  disappears  by  keeping; 
and  also  some  imperfectly  known  gummy  substances,  which  become  brownish  when 
the  wine  is  submitted  to  evaporation.  The  presence  of  these  in  wine  ap}>ears  chiefly  to 
be  determined  by  the  soil,  and  the  condition  and  locality  of  the  vineyard;  and  it  is 
obvious  that  the  qualities  dependent  upon  these  extractive  matters  cannot  be  replaced 
by  sugar. 

It  is  of  importance  that  the  free  acid  be  not  removed  before  the  fermentation,  because 
on  its  presence  during  this  process,  as  well  as  during  the  storing,  depend  the  taste  and 
principal  qualities. 

WINE,  FAMILY,  may  be  made  by  the  following  recipe: — ^Take  black,  red,  white 
currants,  ripe  cherries  (black  hearts  are  the  best),  and  raspberries,  of  each  an  equal 
quantity.  To  4  pounds  of  the  mixed  fruit,  well  bruised,  put  1  gallon  of  clear  soft 
water;  steep  three  days  and  nights,  in  open  vessels,  frequently  stirring  up  the  magma; 
then  strain  through  a  hair  sieve ;  press  the  residuary  pulp  to  dryness,  and  add  its  juice 


f 


960 


¥ 


WIRE-DRAWING. 


s'«-t"i  '^z[  rr  rj:  '"S3''  f T--- ^^^^^^^^^^ 

Cognac  brandy,  (but  not  the  druled  imka  fon^n  !f^-^  f "°."''  P"^  ^  q"«rt  of  g^oof 
and  bung  down.  If  it  does  not  Hon  be  ome  fine  a  s?.l?  '^^"^r  •^-  ^j^'^  ^•«'"  whiskey) 
into  the  hquid,  in  the  proportion  of  VhTfiir'  ^^^^P^"g  of  isinglass  may  be  stirred 
that  the  addition  of  1  o'.  oHit™  of'LHl\f eT  "^  '^  ?  f"?""  ^  l-ve^fouol 
improves  the  quality  of  the  wine  and  ZhL  V  ^,^"^°  ^^  *'»^  fermentable  liquor 
the  grape.       ^        "^  ^'^^'  ^"^  '"^^^s  it  resemble  more  nearly  the  produce  of 


Description. 


1850. 


galls. 

alls. 


Cape 

French      -  .p. 

Canary,  Fayal,  Madeira, 

Portugal,       Rbenieb, 

and  Spanish    • 


Total 


234,779 
600,243 

8|469,290 


1851. 


407,158 
764,931 


7,836,336 


Retained  for  Consumj.tion. 


Duty  received. 


1850. 


9,304,312    9,008,420 


246,498 
363,483 

6,072,637 


1851. 


234,794 
-168,486 


5,851,149 


1850. 


£ 

a5,606 
105,277 


1351. 


33,914 
134,812 


1,752,033  1,687,605 


6,684.668    j     6,551,429  1,892.916    |     ,,856,331 

.n^bo'JL'Jof^v^in^'  JaLt'"^^^^^^^^^^^^ 

obirS''.S^^^  ^-Y'-/,  GciTn.)      When  an 

a  steel  plate  so  as  to  assume  in  its  cross  StlThrfor'"  dim  nishing  apertures  in 
hole,  and  to  be  augmented  in  length  at  the  expense  of  i,f T  T'^  dimensions  of  the  last 
drawn  The  piece  of  steel  called  the  Tl  X//f.  n"  Y^""^'''  '^  '^  ^^''^  *«  ^^  wire. 
Jioles  from  the  largest  to  the  smallest  •  and  he  Lchrne  for  "^''^  '^  ^'^"^^^*  ^'•«^^^^°»  ^^ 
sion  of  the  metallic  particles  to  one  another  i.  r^i.^r  I  ^^i"  overcoming  the  lateral  adhcv 
lay  hold  of  the  extremity  of  the  wfre  to  null  It  .h  ^5'  ^raw^^nch.  The  pincers  which 
to  bite  it  firmly,  by  having  the  n^de'of  tfe  a  v  'cm  lil-  '^^"^^^^^'^^^^^^'  ^^^^  ^dlp  S 
of  giJt  Silver  down  into  stout  wire,  the  hjS  c  pre  t  ^f  ^^  For  drawing  thick  tods 
advantage.  '  ^  ^^^^^  ^^s  been  had  recourse  to  with 

■'^^^' 1540  represents  a  convenient  form  nff  ho  ^        i. 
by  a  ,„„„.e.  „^ee,,  p.-„.„,  a„a  ^XCrCL'^l^^^'iTill^^t,^^^^^^^^^^^^^ 

""  ing  at  a  winch  J  the  motion  being  so 

regulated  by  a  fly-wheel,  that  it  does 
not  proceed  in  fits  and  stans,  and  cause 
mequahiies  in  the  wire.  The  mTaJ 
requires  to  be  annealed,  now  and  the^ 
between  successive  drawings,  other-' 

brittle  for  further  extension.     The  reel 
r^ntTd'^'^'^^^^^^^^^^o^^etimel 
Deer,  tor  the  purpose  of  clearing  off' 
oxyde  formed  in  the  annealing,  before  the  wire  enters  the  dm^nln!  ^'''*'  ^"^  ""^^  «f' 

When,  for  very  accurate  purposes  of  science  or  thp  L^fe    ^"^'^l^- 
form  wire  is  to  be  drawn,  a  Vlafe  with  one  or  Lretwe^edVn^  ^^"^'^  ^^  "«i- 

or  more  perforated  rubies,  sapphires,  or  chrysSues  Jn  !i  v ''  ^^^*  ^''''  ^^'^^  ^^'tb  one 
holes  even  in  the  best  steel  become  Cidly  wTder  hv  ?1  k""^  ^^  *''"''*^^  *«'  ^^^^^^^  the 
ruby,  0.0033  of  an  inch  in  diameter,  a'sH^er  ^Tre  ?70  mlln  ^""1  l*''""^^  ^  ^"^^^  '"«  « 
possessed  at  the  end  the  very  same  section  arLt  til  u"^'  °"-  ^^^  ^^^^  drawn,  which 
weighing  portions  of  equal  length,  as  als'bv  me^Uri^i'If;^^^^^^^  ^  ''^«"^t  determined  Ty 
an  ordinary  draw-plate  of  soft  steel  becomes  so  w^dp  hv iT ^  micrometer.  The  hole  in 
wire  th«t  it  requires  to  be  narrowed  befoTe  the  oT  ofnnf.l  T'""  ^^'^^^  ^"^^°"^^  ^^  brass 
U  n-e,  by  boir.g  din.inlshe.l  one  half,  one  thirf  ono  ff'T  ""^  ^^  "^^^"  ^^^^'^ed! 

mented  m  length  respectively,  f.„„.   ni  .^  sKtt    'thnL  "i"     '4'''  '"  ^^^rr^^ter,  is  nu^r- 
may  be  prudently  drawn  ouCd.pends  up^^  ^^du^^  ^  l^i^J^^thrt^^^lt; 


WOLFRAM. 


;^1 


may  be  always  increased  the  more  the  wire  becomes  attenuated,  because  **t8  particlea 
progressively  assume  more  and  more  of  the  filamentous  form,  and  accommodate  them- 
selves more  readily  to  the  extending  force.  Iron  and  brass  wires,  of  0-3  inch  in  diame- 
ter, bear  drawing  at  the  rate  of  from  12  to  15  inches  per  second;  but  when  of  0-025  (  i  ) 
of  an  inch,  at  the  rate  of  from  40  to  45  inches  in  the  same  time.  Finer  silver  and  cop- 
per wire  may  be  extended  from  60  to  70  inches  per  second. 

By  enclosing  a  wire  of  platinum  within  one  of  silver  ten  times  thicker,  and  drawing 
down  the  compound  wire  till  it  be  ^1^  of  an  inch,  a  wire  of  platinum  of  «  _  of  an 
inch  will  exist  in  its  centre,  which  may  be  obtained  apart,  by  dissolving  the  sflver  away 
m  nitric  acid.    This  pretty  experiment  was  first  made  by  Dr.  WoUaston. 

The  French  draw-plates  are  so  much  esteemed,  that  one  of  the  best  of  them  used  to 
be  sold  in  this  country,  during  the  late  war,  for  its  weight  in  silver.  The  holes  are 
formed  with  a  steel  punch ;  being  made  large  on  that  side  where  the  wire  enters,  and 
diminishing  with  a  regular  taper  to  the  other  side.  In  the  act  of  drawinff,  they  must  be 
well  supplied  with  grease  for  the  larger  kinds  of  wire,  and  with  wax  for  the  smaller. 

WOAD  (FoMerfe,  Pastel,  Fr. ;  Waid,  Germ.;  Isatis  tinctoria,  Linn.),  the  glastum  of 
the  ancient  Gauls  and  Germans,  is  an  herbaceous  plant  which  was  formerly  much  cuiti 
rated,  as  affording  a  permanent  blue  dye,  but  it  has  been  in  modern  times  well  nigh 
superseded  by  indigo.  Pliny  says,  «  A  certain  plant  which  resembles  plantago,  called 
glastum,  is  employed  by  the  women  and  girls  in  Great  Britain  for  dyeing  their  bodies  all 
over,  when  they  assist  at  certain  religious  ceremonies;  they  have  then  the  color  of 
Ethiopians." — Hist.  Nat.  cap.  xxii.  §  2. 

When  the  arts,  which  had  perished  with  the  Roman  empire,  were  revived,  in  the  middle 
ages,  woad  began  to  be  generally  used  for  dyeing  blue,  and  became  an  object  of  most 
extensive  cultivation  in  many  countries  of  Europe.  The  environs  of  Toulouse  and 
Miiepoix,  ill  Upper  Languedoc,  produced  annually  40,000,000  pounds  of  the  prepared 
woad,  or  pastel,  of  which  200,000  bales  were  consumed  at  Bordeaux.  Beruni,  a  rich 
manufacturer  of  this  drug,  became  surety  for  the  payment  of  the  ransom  of  his  kinir 
Francis  I.,  then  the  prisoner  of  Charles  V.  in  Spain. 

^  The  leaves  of  woad  are  fermented  in  heaps,  to  destroy  certain  vegetable  principles 
injurious  to  the  beauty  of  the  dye,  as  also  to  elaborate  the  indigoferous  matter  present, 
before  they  are  brought  into  the  market ;  but  they  should  be  carefully  watched  during 
this  process.  Whenever  the  leaves  have  arrived  at  maturity,  a  point  judged  of  very  dif- 
ferently in  different  countries,  they  are  stripped  off  the  plant,  a  cropping  which  is  repealed 
as  ofien  as  they  shoot,  being  three  or  four  times  in  Germany,  and  eight  or  ten  times  in 
Italy.  The  leaves  are  dried  as  quickly  as  possible,  but  not  so  much  as  to  become  black ; 
and  they  are  ground  before  they  get  quite  dry.  The  resulting  paste  is  laid  upon  a  sloping 
pavement,  with  gutters  for  conducting  the  juice,  which  exudes  into  a  tank ;  the  heap 
being  tramped  from  time  to  lime,  to  promote  the  discharge  of  the  juice.  The  woad  fer- 
ments, swells,  and  cracks  in  many  places,  which  fissures  must  be  closed ;  the  whole  being 
occasionally  watered.  The  fermentation  is  continued  for  twenty  or  thirty  days,  in  cold 
weather;  and  if  the  leaves  have  been  gathered  dry,  as  in  Italy,  for  four  months.  When 
the  fermented  heap  has  become  moderately  dry,  it  is  ground  again,  and  put  up  in  cakes 
of  from  one  lo  three  pounds ;  which  are  then  fully  dried,  and  packed  up  in  bundles  for 
the  market.     Many  dyers  subject  the  pastel  to  a  second  fermentation. 

1,600  square  toises  (fathoms)  of  land  afford  in  two  cuttings  at  least  19,000  pounds  of 
leaves,  of  which  weight  four  fifths  are  lost  in  the  fermentation,  leaving  3,880  pounds  of 
pastel,  in  loaves  or  cakes.  When  good,  it  has  rather  a  yellow,  or  greenish-yellow,  than 
a  blue  color ;  it  is  light,  and  slightly  humid ;  it  gives  to  paper  a  pale-green  trace*;  and 
improves  by  age,  in  consequence  of  an  obscure  fermentation ;  for  if  kept  four  years  it 
dyes  twice  as  much  as  after  two  years.  According  to  Hellot,  4  pounds  of  Guatimala  in- 
digo produce  the  same  effect  as  210  pounds  of  the  pastel  of  Albi.  At  Quins,  in  Pied- 
mont, the  dyers  estimate  that  6  pounds  of  indigo  are  equivalent  to  300  of  pastel ;  bnt 
Chaplal  thinks  the  indigo  underrated. 

Pastel  will  dye  blue  of  itself,  but  it  is  commonly  employed  as  a  fermentative  addition 
to  the  proper  blue  vat,  as  described  under  Indigo. 

Fresh  woad,  analyzed  by  Chevreul,  afforded,  in  100  parts,  65-4  of  juice.  After  being 
steeped  in  water,  the  remaining  mass  yielded,  on  expression,  29-65  of  liquid ;  being  in 
whole,  95-05  parts,  leaving  4-95  of  ligneous  fibre.  The  juice,  by  filtration,  gave  1-95  of 
green  fecula.  100  parts  of  fresh  woad,  when  dried,  are  reduced  to  13-76  parts.  Alco- 
hol, boiled  upon  dry  woad,  deposites,  after  cooling,  indigo  in  microscopic  needles ;  but  these 
cannot  be  separated  from  the  vegetable  albumine,  which  retains  a  greenish-gray  color. 

WOLFRAM  is  the  native  tungsiate  of  iron  and  manganese,  a  mineral  which  occurs 
in  primitive  formations,  along  with  the  ores  of  tin,  antimony,  and  lead,  in  the  Bohemian 
Erzegebirge,  in  Cornwall,  Switzerland,  North  America  &c.  It  is  used  by  chemists  for 
obtaining  tungstic  acid  and  tungsten. 


962 


WOOD. 


ducted  from  the  root  towards  the  bran^hfsar^^^^^^^        tf  ^Vu'  ""l'^'  J"^^^«  ^  «>»- 
The  ligneous  fibre  is  the  substance  Xch  remains  Sth^^^  '^'  ^'^^^^^^'^ 

the  solvent  action  of  ether  alcohol  wnt pt  ^n.fto  '  -i  .  ^^^^^  ^*^  ^^'^  subjected  to 
considered  by  chemists  thitd^tJrnT!'  •  !^  *^'^''  *"^  ^^'^^^^'^  ^^kaline  leys.  It  S 
and  4  of  soluble  ma  S  t  00^  hm^itZT''"'  *""  *"  ^^^"""^^^  «^  ^^  P^^^^  of  fibrou^ 
wns,  the  soil,  and  the  Plant  All  JilS  r  f  ^PfV^^^  ^^^  somewhat  with  the  ^a^ 
of  it  under  the  exhaust^  receiti  oft ""'  "^"^  ''"^u  ^"  .^«*"'''  ^^«"  P^^^^^d  in  a  bSfn 

mto  a  pulverulent  mass,  but  eveSlv  Hk^S     ^T^   ^^"""^^  i""'^^  **^  cohefcnce,  falls 
strong  caustic  alkaline  leys 7n  a  W  sta^^^  into  oxalic  acid; 'with 

Carbon     -  .  .  Sj,%  Beech. 

s^;:r.     :     -     ■  f i         'i:ll 

_^W  of  the  DiST.u,AT.oN  of  0»E  Ponm  of  Wood,  dried,  at  m  Fahr. 


r 


Name  of  the  wood. 


White  birch  - 

Red  beech         -        .        . 

Prick  wood  (spindle  tree) 

Large  leaved  linden    - 

Bed  or  scarlet  oak 

White  beech       -        .        . 

Common  ash 

Horse  chestnut  -        -        . 

Italian  poplar 

Silver  poplar 

White  willow 

Root  of  the  sassafras  laurel 

Wild  service  tree  - 

Basket  willow    -        . 

Dogberry  tree 

Buckthorn  ... 

Logwood 

Alder         .        .        . 

Juniper         -        .        ,    ' 

White  fir  (deal) 

Common  pine  wood 

Savine  tree         -       -        . 

Red  deal  (pine)     -        -    * 

Guiac  wood  -    .        . 


Weight  of 
wood  acid 


One  ounce  of  the 

acid  saturates  of 

carlxinate  of 

potash. 


Welphtofthe 

combustible 

oU. 


Weight  of  the 
charcoal. 


•  /I  ?^°l  ***®  ■™*^^  difference  found 
I«i  «I'47).  I  am  inclined  to  think  that 
lOiopAy  of  Miomfacturti,  2d  edition,  pp, 


97,  98,  99?  ^  """y  ^  conwdered  to  be  equd," 


50)  and  of  cot 
Of  1-50.— PW 


H 


WOOLLEN  MANUFACTURE. 


963 


mixed  with  a  sufficient  quantity  of  wheat  flour,  made  a  coherent  dough  with  water, 

•which  formed  an  excellent  food  for  pigs;  apparently  showing  that  the  digestive  organs 

of  the  animal  could  operate  the  same  sort  of  change  upon  wood  as  sulphuric  acid  does. 

WOOD-PRESERVING.    Mr.  Bethell's  invention  consists  in  impregnaung  wood 

throughout  with  oil  of  tar  and  other  bituminous  matters,  containing  creosote,  and  also 

with  pyrolignite  of  iron,  which  holds  more  creosote  in  solution  than  any  other  watery 

menstruum. 

The  wood  is  put  in  a  close  iron  tank,  like  a  high-pressure  steam-boiler,  which  is  then 
closed  and  filled  with  the  tar  oil  or  pyrolignite.  The  air  is  then  exhausted  by  air- 
pumps,  and  afterward  more  oil  or  pyrolignite  is  forced  in  by  hydrostatic  pumps,  until  a 
pressure  equal  to  from  100  to  150  pounds  to  the  inch  is  obtained.  This  pressure  is 
kept  up  by  the  frequent  working  of  the  pumps  during  six  or  seven  hours,  whereby  the 
wood  becomes  thoroughly  saturated  with  the  tar  oil,  or  the  pyrolignite  of  iron,  and 
"Will  be  found  to  weigh  from  8  to  12  pounds  per  cube  foot  heavier  than  before. 

In  a  large  tank,  like  one  of  those  used  on  the  Bristol  and  Exeter  railway,  20  loads 
of  timber  per  day  can  be  prepared. 

The  effect  produced  is  that  of  perfectly  coagulating  the  albumen  in  the  sap,  thus  pre- 
ventmg  its  putrefaction.  For  wood  that  will  be  much  exposed  to  the  weather,  and  al- 
ternately wet  and  dry,  the  mere  coagulation  of  the  sap  is  not  sufficient ;  for  although 
the  albumen  contained  in  the  sap  of  the  wood  is  the  most  liable  and  the  first  to  pu- 
trefy, yet  the  ligneous  fibre  itself,  after  it  has  been  deprived  of  all  sap,  will,  when  ex- 
posed m  a  warm  damp  situation,  rot  and  crumble  into  dust.  To  piv^erve  wood,  there- 
fore, that  will  be  much  exposed  to  the  weather,  it  is  not  only  necessary  that  the  sap 
should  be  coagulated,  but  that  the  fibres  should  be  protected  from  moisture,  which  is 
effectually  done  by  this  process. 

The  atmospheric  action  on  wood  thus  prepared  renders  it  tougher,  and  infinitely 
stronger.  A  post  made  of  beech,  or  even  of  Scotch  fir,  is  rendered  more  durable,  and 
as  strong  as  one  made  of  the  best  oak;  the  bituminous  mixture  with  which  all  its  pores 
are  filled  acting  as  a  cement  to  bind  the  fibres  together  in  a  close  tough  mass ;  and  the 
more  porous  the  wood  is,  the  more  durable  and  tough  it  becomes,  as  it  imbibes  a 
greater  quantity  of  the  bituminous  oil,  which  is  proved  by  its  increased  weight.  The 
materials  which  are  injected  preserve  iron  and  metals  from  corrosion ;  and  an  iron  bolt 
driven  into  wood  so  saturated,  remains  perfectly  sound  and  free  from  rust.  It  also 
resists  the  attack  of  insects ;  and  it  has  been  proved  by  Mr.  Pritchard,  at  Shoreham  Har- 
bor, that  the  teredo  navalisy  or  naval  worm,  will  not  touch  it. 

Wood  thus  prepared  for  sleepers,  piles,  post,  fencing,  &c.,  is  not  at  all  affected  by 
alternate  exposure  to  wet  and  dry ;  it  requires  no  painting,  and  after  it  has  been  ex- 
posed to  the  air  for  some  days  it  loses  every  unpleasant  smell. 

This  process  has  been  adopted  by  the  following  eminent  engineers,  viz. :  Mr.  Robert 
Stephenson,  Mr.  Brunei,  Mr.  Bidder,  Mr.  Brathwaite,  Mr.  Buck,  Mr.  Harris,  Mr.  Wick- 
stead,  Mr.  Pritchard,  and  others ;  and  has  been  used  with  the  greatest  success  on  the 
Great  Western  railway,  the  Bristol  and  Exeter  railway,  the  Manchester  and  Birming- 
ham railway,  the  North  Eastern,  the  South  Eastern,  the  Stockton  and  Darlington,  and 
at  Shoreham  Harbor ;  and  lately,  in  consequence  of  the  excellent  appearance  of  the 
prepared  sleepers,  after  three  years'  exposure  to  the  weather,  an  order  has  been  issued 
by  Mr.  Robert  Stephenson,  that  the  sleepers  hereafter  to  be  used  on  the  London  and  Bir- 
mingham railway  are  to  be  prepared  with  it  before  being  put  down. 

The  expense  of  preparing  the  wood  varies  from  10*.  to  15*.  per  load,  according  tc 
situation,  and  the  distance  from  the  manufactories  where  the  material  is  made. 

Mr.  Bethell  supplies  the  material  at  a  low  price  from  his  manufactories,  either  at 
Nine  Elms,  Vauxhall ;  Bow  Common ;  or  Birmingham ;  and  parties  prepare  the  timber 
themselves. 

For  railway  sleepers  it  is  highly  useful,  as  the  commonest  Scotch  fir  sleeper,  when 
thus  prepared,  will  last  fo  ce?ituries.  Those  which  have  been  in  use  3  years  and  up- 
ward, look  much  belter  now  than  when  first  laid  down,  having  become  harder,  more 
consolidated,  and  perfectly  waterproof;  which  qualities,  combined  with  that  of  per- 
fectly resisting  the  worm,  render  this  process  eminently  useful  for  piles,  and  all  other 
woodwork  placed  under  water.  Posts  for  gates  or  fencing,  if  prepared  in  this  manner, 
may  be  made  of  Scotch  fir,  or  the  cheapest  wood  that  can  be  obtained,  and  will  not  de- 

*^^tK^^*!^  P®^^^'  ^^^^^  invariably  become  rotten  near  the  earth  after  a  few  years. 
WOOF,  18  the  same  as  Weft. 

WOOLLEN  MANUFACTURE  In  reference  to  textile  fabrics,  sheep's  wool  » 
of  two  different  sorts,  the  short  and  the  long-stapled ;  each  of  which  requires  different 
modes  of  manufacture  in  the  preparation  and  spinning  processes,  as  also  in  the  treatment 
of  the  cloth  after  it  is  woven,  to  fit  it  for  the  market  Each  of  these  is,  moreover  dis- 
tinguished in  commerce  by  the  names  of  fleece  wools  and  dead  wools,  according  as 'they 


wmwm 


«i 


I 

I 


964 


WOOLLEN  MANUFACTURE. 


have  been  shorn  at  the  usual  annual  period  from  the  living  animal,  or  are  cut  from  ill 
skin  after  death.  The  latter  are  comparatively  harsh,  weak,  and  incapable  of  imbibinff 
the  dyemg  principles,  more  especially  if  the  sheep  has  died  of  some  malignant  distemper 
The  annular  pores,  leading  into  the  tubular  cavities  of  the  filaments,  seem,  in  this  case* 
to  have  shrunk  and  become  obstructed.  The  time  of  year  for  sheep-shearing  most  favor- 
able to  the  quality  of  the  wool,  and  the  comfort  of  the  animal,  is  towards'  the  end  of 
June  and  beginning  of  July ;— the  period  when  Lord  Leicester  holds  his  celebrated  rural 
tete  for  that  interesting  purpose. 

The  wool  of  the  sheep  has  been  surprisingly  improved  by  its  domestic  culture.    The 
mouflon  (Ovis  aries),  the  parent  stock  from  which  our  sheep  is  undoubtedly  derived 
and  which  is  still  found  in  a  wild  aate  upon  the  mountains  of  Sardinia,  Corsica,  Barbary' 
Greece,  and  Asia  Minor,  has  a  very  short  and  coarse  fleece,  more  like  hair  than  wool. 
When  this  animal  is  brought  under  the  fostering  care  of  man,  the  rank  fibres  gradually 
disappear;  while  the  soft  wool  round  their  roots,  little  conspicuous  in  the  wild  animal, 
becomes  singularly  developed.     The  male  most  speedily  undergoes  this  chan?e,  and  con- 
tinues ever  afterwards  to  possess  far  more  power  in  modifying  the  fleece  of  the  oflspring 
than  the  female  parent.    The  produce  of  a  breed  from  a  coaVse-woolled  ewe  and  a  fine- 
woolled  ram  is  not  of  a  mean  quality  between  the  two,  but  half-way  nearer  that  of  the 
fire.     By  coupling  the  female  thus  generated  with  such  a  male  as  the  fonner,  another 
improvement  of  one  half  will  be  obtained,  affording  a  staple  three  fourths  finer  than  that 
of  the  grandam.     By  proceeding  inversely,  the  wool  would  be  as  rapidly  deteriorated. 
It  IS,  therefore,  a  matter  of  the  first  consequence  in  wool  husbandrj-,  to  exclude  from  the 
flock  all  coarse-fleeced  rams. 

Long  wool  is  the  produce  of  a  peculiar  variety  of  sheep,  and  varies  in  the  length  of 
Its  fibres  from  3  to  8  inches.  Such  wool  is  not  carded  like  cotton,  but  combed  like  flax, 
either  by  hand  or  appropriate  machinery.  Short  wool  is  seldom  longer  than  3  or  4 
inches;  it  is  susceptible  of  carding  and  feltin?,  by  which  processes  the  filaments  become 
first  convoluted,  and  then  densely  matted  together.  The  shorter  sorts  of  the  combine 
wool  are  used  principally  for  hosiery,  though  of  late  years  the  finer  kinds  have  been 
extensively  worked  up  into  Merino  and  mousseline-de-laine  fabrics.  The  longer  wools 
of  the  Leicestershire  breed  are  manufactured  into  hard  yarns,  for  worsted  pieces  such  as 
waistcoats,  carpets,  bombazines,  poplins,  crapes,  &c.  * " 

The  wool  of  which  good  broadcloth  is  made  should  be  not  only  shorter,  but  generallr 
speaking,  finer  and  softer  than  the  worsted  wools,  in  order  to  fit  them  for  the  fillin*'  pro- 
cess. Some  wool-sorters  and  wool-staplers  acquire  by  practice  great  nicety  of  discern- 
ment  in  judging  of  wools  by  the  touch  and  traction  of  the  fingers.  Two  years  ago  I 
made  a  series  of  observations  upon  different  wools,  and  published  the  results  Vhe 
filaments  of  the  finer  qualities  varied  in  thickness  from  -^L_  to  i  _  of  an  inch;  their 
•tructure  is  very  curious,  exhibiting,  in  a  good  achromatic  m?croscope,\°t  intervals  of  about 
jJ^of  an  inch,  a  series  of  serrated  rings,  imbricated  towards  each  other,  like  the  joints 
of  Equisetum,  or  rather  like  the  scaly  zones  of  a  serpent's  skin.  See  Philosophy  of 
Manufactures,    gs.  11,  12,  page  9 J,  second  edition.  ^  »    ./ 

There  are  four  distinct  qualities  of  wool  upon  every  sheep ;  the  finest  being  upon  the 
spme,  from  the  neck  to  within  6  inches  of  the  tail,  including  one  third  of  the  breadth  of 
the  back;  the  second  covers  the  flanks  between  the  thighs  and  the  shoulders;  the  third 
clothes  the  neck  and  the  rump  ;  and  the  fourth  extends  upon  the  lower  part  of  the  neck 
and  breast  down  to  the  feet,  as  also  upon  a  part  of  the  shoulders  and  the  thighs,  to  the 
bottom  of  the  hmd  quarter.  These  should  be  torn  asunder,  and  sorted,  immediately  after 
the  shearing.  ' 

The  harshness  of  wools  is  dependant  not  solely  upon  the  breed  of  the  animal  or  the 
clunate,  but  is  owing  to  certain  peculiarities  in  the  pasture,  derived  from  the  soil.  It  is 
known,  that  m  sheep  fed  upon  chalky  districts,  wool  is  apt  to  get  coarse;  but  in  those 
upon  a  rich  loamy  soil,  it  becomes  soft  and  silky.  The  ardent  sun  of  Spain  renders  the 
fleece  of  the  Merino  breed  harsher  than  it  is  in  the  milder  climate  of  Saxony.  Smearing 
sheep  with  a  mixture  of  tar  and  butter  is  deemed  favorable  to  the  softness  o^  the'a 
wool. 

All  wool,  in  its  natural  state,  contains  a  quantity  of  a  peculiar  potash-sGap,  secreted 
by  the  animal,  called  m  this  country  the  yolk;  which  may  be  washed  out  by  water  alone 
with  which  It  forms  a  sort  of  lather.    It  constitutes  from  25  to  50  per  cent,  of  the  wool 
being  most  abundant  m  the  Merino  breed  of  sheep;   and  however  favorable  to  the 
growth  of  the  wool  on  the  living  animal,  should  be  taken  out  soon  after  it  is  shorn,  lest 
it  injure  the  fibres  by  fermentation,  and  cause  them  to  become  hard  and  brittle.     After 
being  washed  m  water,  somewhat  more  than  lukewarm,  the  wool  should  be  well  Dressed 
and  carefully  dried.  *^  * 

Mr.  Hicks,  of  Huddersfield,  obtained  a  patent  some  years  ago  for  a  machine  for 
cleaning  wool  from  burs.  It  consists  of  4  rotary  beaters,  which  act  in  succession.  The  wool 
having  been  opened  and  spread  upon  a  feeding  cloth  is  carried  by  it  to  the  drawing  rollera^ 


WOOLLEN  MANUFACTURE. 


965 


and  is  then  delivered  to  the  action  of  the  beater,  by  which  it  is  carried  along  a  curved 
grating  to  the  feed  cloth  of  another  beater,  so  as  to  be  made  eventually  quite  clean. 

England  grows  annually  about  1,000,000  packs  of' wool.  The  quantity  imported 
into  the  United  Kingdom,  in  1850,  was  72,674,483  lbs.;  in  1861,  81,063,679  lb& ;  of 
which,  48,240,529  lbs.  and  51,993,463  lbs.  respectively  were  from  British  possessions. 

Having  premised  these  general  observations  on  wool,  I  shall  now  proceed  to  treat  of 
its  manufacture,  beginning  with  that  of  wool-combing,  or 

THE  WORSTED  MANUFACTURE. 

In  this  branch  of  business,  a  long  stapled  and  firm  fibre  is  required  to  form  a  smooth 
level  yarn,  little  liable  to  shrink,  curl,  or  felt  in  weaving  and  finishing  the  cloth.  It  must 
not  be  entangled  by  carding,  but  stretched  in  lines  as  parallel  as  possible,  by  a  suitable 
system  of  combing,  manual  or  mechanical. 

When  the  long  wool  is  brought  into  the  worsted  factor)',  it  is  first  of  all  washed  by 
men  with  soap  and  water,  who  are  paid  for  their  labor  by  the  piece,  and  are  each  assisted 
by  a  boy,  who  receives  the  wool  as  it  issues  from  between  the  drying  squeezers,  (see  Bleach- 
ing.) The  boy  carries  off  the  wool  in  baskets,  and  spreads  it  evenly  upon  the  floor  of 
the  drying-room,  usually  an  apartment  over  the  boilers  of  the  steam-engine,  which  is  thus 
economically  heated  to  the  proper  temperature.  The  health  of  the  boys  employed  in  this 
business  is  found  to  be  not  at  all  injured. 

The  wool,  when  properly  dried,  is  transferred  to  a  machine  called  the  plucker,  which 
is  always  superintended  by  a  bvy  of  12  or  14  years  of  age,  being  very  light  work.  He 
lays  the  tresses  of  wool  pretty  evenly  upon  the  feed-apron,  or  table  covered  with  an 
endless  moving  web  of  canvass,  which,  as  it  advances,  delivers  the  ends  of  the  long  tufts 
to  a  pair  of  fluted  rollers,  whence  it  is  introduced  into  a  fanning  apparatus,  somewhat 
similar  to  the  wUlow  employed  in  the  cotton  manufacture,  which  see.  The  filaments 
are  turned  out,  at  the  opposite  end  of  this  winnowing  machine,  straightened,  cleaned, 
and  ready  for  the  combing  operation.    According  to  the  old  practice  of  the  trade,  and  still 


1541 


for  the  finer  descriptions  of  the  long  staple, 
according  to  the  present  practice,  the  wool 
is  carded  by  hand.  This  is  far  more  severe 
labor  than  any  subservient  to  machinery, 
and  is  carried  on  in  rooms  rendered  close 
and  hot  by  the  number  of  stoves  requisite 
to  heat  the  combs,  and  so  enable  them  to 
render  the  fibres  soft,  flexible,  and  elastic. 
This  is  a  task  at  which  only  robust  men 
are  engaged.    They  use  three  implements ; 

1.  a  pair  of  combs  for  each  person ;  2.  a  post,  to  which  one  of  the  combs  can  be  fixed ; 

3.  a  comb-pot,,or  small  stove  for  heating  the  teeth  of  the  combs.     Each  comb  is  composed 


1542 


n 


either  of  two  or  three  rows  of  pointed  tapering  steel  teeth  6, 
fig.  1541,  disposed  in  two  or  three  parallel  planes,  each  row  being 
a  little  longer  than  the  preceding.  They  are  made  fast  at  the 
roots  to  a  wooden  slock  or  head  t,  which  is  covered  with  horn, 
and  has  a  handle  d,  fixed  into  it  at  right  angles  to  the  lines  of  the 
teeth.  The  spaces  between  these  two  or  three  planes  of  teeth, 
is  about  one  third  of  an  inch  at  their  bottoms,  but  somewhat 
more  at  their  tips.  The  first  combing,  when  the  fibres  are  most 
entangled,  is  performed  with  the  two-row  toothed  combs ;  the 
second,  or  finishing  combing,  with  the  three-row  toothed. 

In  the  workshop  a  post  is  planted  {fig.  1542),  upright,  for 
resting  the  combs  occasionally  upon,  during  the  operation. 
An  iron  stem  g,  projects  from  it  horizontally,  having  its  end 
turned  up,  so  as  to  pass  through  a  hole  in  the  handle  of  the 
comb.  Near  its  point  of  insertion  into  the  post,  there  is  an- 
other staple  point  A,  which  enters  into  the  hollow  end  of  the 
handle ;  which,  between  these  two  catches,  is  firmly  secured  to 
the  post.  The  stove  is  a  very  simple  affair,  consisting  merely  ol 
a  flat  iron  plate,  heated  by  fire  or  steam,  and  surmounted  with  a 
similar  plate,  at  an  interval  sufiicient  to  allow  the  teeth  to  be 

inserted  between  them  at  one  side,  which  is  left  open,  while  the  space  between  their 

edges,  on  the  other  sides,  is  closed  to  confine  the  heat, 
in  combing  the  wool,  the  workman  takes  it  up  in  tresses  of  about  four  ounces  each, 

sprinkles  it  with  oil,  and  rolls  it  about  in  his  hands,  to  render  all  the  filaments  equally 


966 


WOOLLEN  MANUFACTURE. 


r/eT;  a t'L^'k^'exT^f^^^^^^^  /h'^  -'^^^  of  oil,  others  no 

upwards,  seizes  one  half  of  th I  t  ess  of  wooT  r^h?,^!^''  '^t  ^^''^."^^'^  ^^^  teeth  pointed 
draws  it  'through  them,  and  thus  re^teSly^  lei W  a  ^ew  st;^/h7fil'i^^^^^^  ^'V^-^^^'  *'^» 
the  comb.    When  the  comb  has  in  thds  wav  collerT^  **°^«  "P®" 

introducing  the  feelh  oHne  comb    ntn  ^ril      "^' ^I'^  combs  the  wool  upon  the  first,  by 

«lvaL"ressfve|v  horn  .foTenH  ,'«°'",'>y  "-"tJ-S  'he  lips  of  the  tri^Zli 
worked  wi.K  ire  r  t«ihTclc^er.L«w        ■''  ">\?">".'  '"'  »'  "e"«h  the  coibs  are 

«>*/».     Thev  ire  nnfif  f„r  y.  X     .  J^'  """'''"  '"  P'^P  ""^  '»  ••'»  ''»>").  are  called 

combing  heat.     The  comb  form«  »  ^jUio  rTf ^     jeep  me  whole  apparatus  at  a  proper 
.ee.h  b?ing  a.'  ritu.T^^.  to™e  pknetf'.re  the'"'  '^  sh'aZof  rV"'  "il"',''  "■« 

ever  the  wheel  is  dressed,  the  machine  is  made  to  reVre  morf  rapidTrbv  .hiftL'?" 
dnving-band  on  another  pulley;  and  it  is  beautiful  to  observTthe  deSrv /nfl  n^  ^ 
with  which  it  smooths  the  tangled  tress.     When  thrwooTs  Ire  set  fn  rnn? .     1  Pf^*^'«»?» 

l^'ltVt  "•'  whole  leng'th  of  its  fibres,    ^^e  mch  Lstin^.Ln  Ih  i^^^^^ 

The  following  machine,  patented  by  James  IVohlP  nF  Woi;ro»    «,«    ♦  ^      • 

of  th  s  cam  or  heart-wheel    a  lever  rf  i    iT.  '        ""  "»e  upper  part  of  the  periphery 
wHch  lever  is  cor„ectTd  by\  jl7  o  ihe^^rke^'Bv'.he'riS.^^'J^i.™'  *"j'  "f 


WOOLLEN  ^LA.NUFACTUEE. 


967 


1543 


tiM  upper  or  working  comb  or  needle-points  /,  as  it  moves,  performing  an  elliptic^ 

curve,  which  curve 
will  be  dependant 
upon  the  petition 
of  the  heart-wheel 
cam  c,  that  guides 
it.  A  moveable 
frame  g,  carries  a 
series  of  points  hf 
which  are  to  con- 
stitute the  lower 
comb  or  frame  of 
needles.  Into  these 
lower  needles  the 
rough     uncombed 

wool  is  to  be  fed  by  hand,  and  to  be  drawn  out  and  combed  straight  by  the  movements 
of  the  upper  or  working  comb. 

As  It  is  important,  in  order  to  prevent  waste,  that  the  ends  of  the  wool  should  be 
first  combed  out,  and  that  the  needle-points  should  be  made  to  penetrate  the  wool  pro- 
gressively, the  moveable  frame  g,  is  in  the  first  instance  placed  as  far  back  as  possible ; 
and  the  action  of  the  lever  d,  during  the  whole  operation,  is  so  directed  by  the  varying 
positions  of  the  cam-wheel,  as  to  allow  the  upper  comb  to  enter  at  first  a  very  little 
way  only  into  the  wool ;  but  as  the  operation  of  combing  goes  on,  the  frame  with  the 
lower  combs  is  made  to  advance  gradually,  and  the  relative  positions  of  the  revolving 
heart  cam- wheel  c,  being  also  gradually  changed,  the  upper  or  working  needles  are  at 
length  allowed  to  be  drawn  completely  through  the  wool,  for  the  purpose  of  combing  out 
straight  the  whole  length  of  its  fibre. 

In  order  to  give  to  the  machine  the  necessary  movements,  a  train  of  toothed  wheels 
and  pinions  is  mounted,  mostly  on  studs  attached  to  the  side  of  the  frame;  which 
train  of  wheels  and  pinions  is  shown  by  dots  in  the  figure,  to  avoid  confusion.  The  driving 
power,  a  horse  or  steam-engine,  is  communicated  by  a  band  to  a  rigger  on  the  short  axle 
i  ;  which  axle  carries  a  pinion,  taking  into  one  of  the  wheels  of  the  train.  From  this 
wheel  the  crank  e,  that  works  the  lever  d,  is  driven  ;  and  also  by  gear  from  the  same 
pinion,  the  axle  of  the  wheel  6,  carrying  the  eccentric  or  heart-wheel  cam,  is  also  actuated, 
but  slower  than  the  crank-axle. 

At  the   end  of  the  axlo  of  the  wheel  6,  and  cam  c,  a  bevel  pinion  is  afiixed,  which 

gears  into  a  corresponding  bevel  pinion  on  the  end  of  the  lateral  shaft  k.    The  reverse 

end  of  this  shaft  has  a  worm  or  endless  screw  /,  taking  into  a  toothed  wheel  m;  and 

this  last-mentioned  toothed  wheel  gears  into  a  rack  at  the  under  part  of  the  frame  g. 

It  will  hence  be  perceived,  that  by  the  movements  of  the  train  of  wheels,  a  slow 

motion  is  given  to  the  frame  g,  by  which  the  lower 
needles  carrying  the  wool  are  progressively  ad- 
vanced as  the  operation  goes  on ;  and  also,  that  by 
the  other  wheels  of  the  train,  the  heart-wheel  cam 
is  made  to  rotate,  for  the  purpose  of  giving  such 
varying  directions  to  the  stroke  of  the  lever  which 
slides  upon  its  periphery,  and  to  the  working 
comb,  as  shall  cause  the  comb  to  operate  gradual- 
ly upon  the  wool  as  it  is  brought  forward.  The 
construction  of  the  frames  which  hold  the  needles, 
and  the  manner  of  fixing  them  in  the  machine,  pre- 
sent no  features  of  importance ;  it  is  therefore  un- 
necessary to  describe  them  farther,  than  to  say, 
that  the  heckles  are  to  be  heated  when  used  for 
combing  wool.  Instead  of  introducing  the  wool  to 
be  combed  into  the  lower  needles  by  hand,  it  is 
sometimes  fed  in,  by  means  of  an  endless  feeding- 
cloth,  as  shown  in^g.  1544.  This  endless  cloth  is 
distended  over  two  rollers,  which  are  made  to  re- 
volve, for  the  purpose  of  carrying  the  cloth  with 
the  wool  forward,  by  means  of  the  endless  screw 
and  pinions. 

A  slight  variation  in  the  machine  is  shown  at 
fig.  1545,  for  the  purpose  of  combing  wool  of  long 
fibre,  which  dififers  from  the  former  only  in  placing 
the  combs  or  needle  points  upon  a  revolving  cy- 
linder or  shaft.  At  the  end  of  the  axle  of  this  shaft 
there  is  a  toothed  wheel,  which  is  actuated  by  an 


■fMMa 


968 


WOOLLEN  MANUFACTURE. 


endless  screw  upon  a  lateral  shaft.    The  axle  of  the  cylinder  on  which  the  needle.  »« 

.gency  of  the  endless  screw  on'^^e'tS's^^^ltrr^^^  effected  by  th. 

f«r.hrd;a:i'Xme''"b"t7he"l^r.%r'   '"•»«-"''"»<»"  ''""'  "■-"   «  ««»» 

and  contains  the  longer  fibres    the^hort  i.  th  J  wh'  T"  ^'^""^  ""^ ^'''  ^^""^  '^'  ^^'^^^ 

«  begun  at  the  short  ends;  but  if  they  are  iirst  parted  atThe  W  en^/tVey^X^S? 

oh^^J^l'^^ilnf'lT^^^^^^  Donisthorpe  and  Rawson 

eu  a  paieni  in  Apnl,  1835,  has  been  found  to  work  well,  and  therefore  merits 

a  detailed  description  : — 
f^S'  1546,  is  an  elevation ;  ^g. 

1547  an  end  view ;    and  Jig.  1548 
a   plan;     in  which    «,  a,    is    the 
framing ;    6,  the  main  shaft,  bear- 
ing   a    pinion    which    drives    the 
wheel  and  shaft  r,  in  gear  with  the 
wheel   rf,   on    the   shaft   e.      Upon 
each  of  the  wheels  c  and  d,  there 
are    two    projections    or    studs  /, 
which    cause    the    action   of    the 
combs  g,  g,  of  which  A,  h,  are  the 
tables  or  carriages.     These  are  ca- 
pable of  sliding  along    the   upper 
guide     rails    of    the    framing    a. 
Through  ihese  carriages  or   tables 
A,  A,  there  are  openings  or  slits, 
shown   by  dotted  lines,"  which  act 
as  guides  to  the  holders  i,  t,  of  the 
combs  g,  g,  rendering  the  holders 
susceptible    of    motion     at     right 

which  turning  on  the  axis'^o?  shaft  /  /  is  cau4d  toTihril'  ''  ''^^"^  '\^'^'^'  ^>  ^' 
arms  m,  mov^d  by  the  eccentric  groove  n,^^^^^^^^  ^^^^  £«>  ^^  ^^^ 

drawn  inwards,  by  weights  suspended  on  cords  or 'train  nlv  V  ^  t^^es  A,  are 
pulleys  p,  p  ,  whereby  The  weights  have  r  constant  tlnf  '  .'  ^^"^  P''  **^^^  '^^^^^^'^n 
centre  of  The  machine,  as  lo^  as  it  IsrelS^  T^^^^^^  i«'o  the 

projecting  arms  ?,  on  the  tables      0„  the  shaft -^^^^^      *^^  ^^^'^""^  ^^"^ 

which  ta'kes  into  the  ratchet  wheel  "  and  Prooels  JZTP7V\  '""''^  '^  ''  ^^^^ 
of  the  shaft  ..  This  ratchet  wheel  turns  on  an  ax^  Zt  tlM^^'\''l  ^^V  ^^^«^"tion 
made  fast,  to  which  the  cord  or  bandTis  secured  as  aho  ?n  ,hp'n  i.^''  '^^  P"^^''  ^** 
y.  On  the  shaft  y,  there  are  two  other  nullevs  ^  t  kII-  t  ^""7  ^'  °"  *^^  ^^^ 
made  fast  to  the^m,  and  also  to  the  end  of  t?e  fau\  p^^^^^^  bands  a,  >., 

ated  steps,  against  which  the  tables  A,  A  are  drawTn/fi  »  t  '  f"rn>shed  with  graau- 
In  proportion  as  these  gauge-plates  a^e  raTsed  thTnfarl  th  '^''''•'"  '^  the  machine. 
be  able  to  advance  to  the  centre  of  the  mchinr  anJ    S    *'*'"'^.''  ""l  ^^^^^^  ^'  ^"^ 

tolay  hold  of,  and  comb,  additional  lengths  of  the  Woollv  '''  '°"^'i'  ^' ^' 

are  guided  up  by  the  bars  c  which  naL  thrnn Jif  •  f*    ^^^  gauge-plates  b, 

the  framiug  o,  as  sho^  bj  r!'  ^  ^^  o^^mngs,  slots,  or  guides,  made  i^ 


WOOLLEN  MANUFACTURE. 


969 


To  the  ratchet  wheel  s,  an  inclined  projection  e,  is  made  fast,  which  in  the  course  of 
^  rotation  of  the  ratchet  wheel,  comes  under  the  lever  f,  fixed  to  the  shaft  g,  that  turns 
in  bearings  h.    To  this  shaft  the  levers  i  and  J,  are  also  fixed ;  i  serv- 
ing to  throw  out  the  click  or  catch  k,  from  the  ratchet  wheel,  by  which 
the  parts  of  the  machine  will  be  released,  and  restoried  to  positions 
ready  for  starting  again.     The  lever  j,  serves  to  slide  the  drum  upon 
the  driving  shaft  6,  out  of  gear,  by  means  of  the  forked  hancUe  l,  when 
the  machine  is  to  be  stopped,  whenever  it  has  finished  commng  a  cer- 
tain quantity  of  wool.    The  combs  which  hold  the  wool  have  a  motion 
upwards,  in  order  to  take  the  wool  out  of  the  way  of  the  combs  g,  g, 
as  these  are  drawn  into  the  centre  of  the  machine;  while  the  holding 
combs  descend  to  lay  the  wool  among  the  points  of  the  combs  g,  g. 
For  obtaining  this  upward  and  downward  motion, 
the  combs  m,  m,  are  placed  upon  the  frame  n,  and 
retained  there  just  as  the  combs  g,  g,  are  upon  the 
holders  t,  i.    The  framing  n  is  made  fast  to  the  ba* 
or  spindle  o>  which  moves  vertically  through  open- 
ings in  the  cross-head  p,  and  the  cross-framing  of 
the  machine  q  ;  from  the  top  of  which,  there  is  a 
strap  passes  over  pulleys  with  a  weight  suspended 
to  it ;  the  cross-head  being  supported  by  the  two 
guide-rods  r,  fixed  to  the  cross-framing  q.    It  is  by 
the  guide-rods  r,  and  the  spindle  o,  that  the  frame 
N  is  made  to  move  up  and  down  ;  while  the  spindle 
is  made  to  rise  by  the  studs/,  as  the  wheels  c  and  d 
come  successively  under  the  studs  a,  on  the  spin- 
dle o. 

A  quantity  of  wool  is  to  be  placed  on  each  of  the 
combs  g,  g,  and  m,  m,  the  machine  being  in  the  po- 
sition shown  in  fig.  1548.    When  the  main  shaft  6, 
is  set  in  motion,  it  will  drive  by  its  pinion  the  tooth- 
ed wheel  c,  and  therefrom  the  remaining  parts  of 
the  machine.     The  first  effect  of  the  movement  will 
be  to   raise  the  combs  m,  m,  sufiiciently  high  to 
remove  the  wood  out  of  the  way 
of  the  combs  g,  g,  which  will  be 
drawn  towards  the  centre  of  the 
machine,  as  soon  as  they  are  re- 
leased by  the  studs/,  passing  the 
projecting  arms  q,  on  the  tables 
A ;  but  the  distance  between  the 
combs  g,  g,  and  the  combs  h,  h, 
will    depend    on   the    height   to 
which  the  gauge-plates  b,   have 
been  raised.      These  plates  are 
raised  one  step  at  each  revolu- 
tion of  the  shaft  c ;  the  combs  g, 
g,  will  therefore  be  continually 
approaching  more  nearly  to  the 
as  to  permit  the  tables  A,  to  ap- 


eombs  m,  m 
proach   the 


,  till  the 
plates  B, 


plates  B,  are  so  much  raised 


below  the  lowest  step  or  graduation,  when   the  machine  will 


continue  to  work.     Notwithstanding  the  plates 
parallel  surfaces  against  which  the  tables  come, 


B,  continuing  to  rise,  there  being  only 
the  combs  g,  g,  will  successively  come 
to  the  same  position,  till  the  inclined  projection  e,  on  the  ratchet  wheel  «,  comes  under 
the  lever  f,  which  will  stop  the  machine.  The  wool  which  has  been  combed  is  then  to 
be  removed,  and  a  fresh  quantity  introduced.  It  should  be  remarked,  that  the  combs  g, 
g,  are  continually  moving  from  side  to  side  of  the  machine,  at  the  same  time  that  they  are 
combing  out  the  wool.  The  chief  object  of  the  invention  is  obviously  to  give  the  above 
peculiar  motions  to  the  combs  g,  g,  and  m,  m  ;  which  may  be  applied  also  to  combing  goat- 
hair. 

For  the  ])urposes  of  the  worsted  manufacture,  \iiool  should  be  rendered  inelastic  to  a 
considerable  degree,  so  that  its  fibres  may  form  long  lines,  capable  of  being  twisted  into 
straight  level  yarn.  Mr.  Bayliffe,  of  Kendal,  has  sought  to  accomplish  this  object, 
first,  by  introducing  into  the  drawing  machine  a  rapidly  revolving  wheel,  in  contact  with 
the  front  drawing  roller,  by  whose  friction  the  filaments  are  heated,  and  at  the  same 
time  deprived  of  their  curling  elasticity ;  secondly,  by  employing  a  moveable  regulating 
roller,  by  which  the  extent  of  surface  on  the  periphery  of  the  wheel  that  the  lengths  ol 


I 


i 


970 


WOOLLEN  MANUFACTURE. 


Mi 


wool  IS  l^  act  upon,  Aay  be  increased  or  diminished  at  pleasure,  and,  consequently   the 
effect  regulated  or  tempered  as  the  quahty  of  the  wool  may  require;  Sy,thl'  em! 

1549  ployment  of  steam  in  a  rotatory  drum,  or  hol- 

lowed wheel,  in  place  of  the  wheel  first  de- 
scribed, for  the  purpose  of  heating  the  wool, 
m  the  process  of  drawing,  in  order  to  facili- 
tate the  operation  of  straighteninir  the 
fibres. 

These  objects  may  be  effected  in  several 
ways ;  that  is,  the  machinery  may  be  vari- 
ously constructed,  and  still  embrace  the 
principles  proposed.  Fig.  1549,  shows  one 
mode:  — a,  is  the  friction  wheel;  6,  the 
front  drawing  roller,  placed  in  the  drawing 
frame  in  the  same  way  as  usual ;  the  larger 
wheel  a,  constituting  the  lower  roller  of  the 
pair  of  front  drawing  rollers;  c,  and  rf,  are 
the  pair  of  back  drawing  rollers,  which  are 
actuated  by  gear  connected  to  the  front  roll- 
inff  machi'npc  fh^  rr««t  ^«ii«-  •  ers,  as  in  the  ordinary  construction  of  draw- 

r»Jn  L      T '    '  i.  *u^"*''^  ^®"^'''  *>ea«'ing  upon  the  periphery  of  the  lar?e  wheel-  f  k 
«  tension  roller,  which  presses  the  fibres  of  the  wool  down  upon  the  wheel  a  "^^ 

fJnt^'uZT^^^^'  ^'''^  ^""^^^  '  «"^  ^  ^«  be  turned  wira  givrveh^ity   and  the 
^t?n  Jth      r  '"^  ^'  ^"^^"  T"'^  ^^''^''  ^^^  '^'''  ^^«»Jd  be,  that  thrfiXes  of  w^J  consU 

|»vi^.  dowa  .0  the  spindie  L  flier  *,  wh^eil  T^J^  7^,!?  1"^^^  ,r  TIZ'^ 


♦V  1    .  ,  •       . —  '-'"*-«  "1  u^i^icasru  oy  a  racK  and  a  winch   not « 

the  rack  taking  mto  teeth  on  the  periphery  of  the  circular  arrn^  " 

jrceived,  that  bv  ra  sin?  thp  n.rn„io.  „.J1    .L  __,       '''^'^"/,?\  *^™-''-. 


uJt^.eans,commJ::;^t:t^^^^^^^^ 

tofhrsh;T{ndTf  Tnot^^^  together,  the  long  end  of  one 

of  the  breakine-frUe  A  skpVph  ^f  v  ^  '^  •'^'T"  «"t  and  extended  by  the  rollers 
4  pairs  of  roUers  A  b'  c  d     ThJ  fr  ^^^^^^^^^^^ '«  given  in  Jig-  1550.    It  consists  of 

E,'which  isTirplank^.Stable'^'Vhfs^vTr^  "^if'-^'i^K^  ^"^""^^  t-"^»> 

a  pin,  in  reach  of  the  attendant,  who  takis  a  sliver  «ni1^  ^^?^\  and  hung  loosely  over 
end  is  presented  to  the  rollers  a,  whkh  bein.'t  mnifn  %V.^  ^**  u  *^^  *~"=^'  *"^  ^^^ 
is  then  conduct:vl  through  the  o  h^^roller  L  sh^wn  ?^  7h"  fi*^^  T"^^  ^"'  '^'  ^^'^^ 
passed  half  through,  the  end  of  anoSiver  is  rZ^d  ,  T^''  TJl'"  i^^  '^''''''  ^^ 
they  pass  throu-h  tooether-  x^hel  t hi*  Jlli  ■    ^  ^^?  ."P°"  ^^^  ^'^^^^  ^^^^^  fi^-st,  and 

is  7pp'lied  upon ^tSe  ^ddle  ift "nd^•^  h  s' way  tCltrt^T^'""'^!:;, ^'L^"k^  ''  ^  '""'^ 
ing  are  joined  into  one  regular  and  even  slTv^r!  "  P'*^"^^  ^^^  *^^  ~°*^ 

The  lower  roller  c  receives  its  motion  from  thp  m;n    w  »,  i. 

end  of  its  axis,  and  an  endless  strap.  The"  ler  whic'h^s  Z^"^-  f ,'  """"?'  "I""  «"• 
down  by  a  heavy  weisht  «ii«iiPnrl<.H  fm-,  i.  ™""J^'''<:'>  «  immediately  over  it,  is  borne 

V      ui  rollers  p,  moves  with  the  same  velocity  as  c,  being  turned 


1 


WOOLLEN  MANUFACTURE. 


971 


fcy  means  of  a  small  wheel  upon  the  end  of  the  axis  of  the  roller  c,  which  turns  a  wheel 
of  the  same  size  upon  the  axis  of  the  roller  d,  by  means  of  an  intermediate  wheel  d, 
which  makes  both  rollers  turn  the  same  way  round.    The  first  and  second  pairs  of 

rollers,  a  and  % 
move  only  one 
third  as  quick  as 
c  and  D,  in  order 
to  draw  out  the 
sliver  between  b 
and  c  to  three 
times  the  length 
it  was  when  pat 
on  the  planking« 
table,  'fhe  slow 
motion  of  the  roll- 


ers 


IS 


given 
by  a  large  wheel 
o,  fixed  upon  the 
axis  of  ihe  roller 
A,  and  turned  by 
the  intermediate 
cog-wheels  6,  c, 
and  d ;    the  latter 

communicates  between  the  rollers  c  and  d.  The  pinions  on  the  rollers  c  and  d  being  only 
one  third  the  size  of  the  wheel  a,  c  and  d  turn  three  times  as  fast  as  a,  for  6,  c,  and  d,  are 
only  intermediate  wheels.  The  rollers  b  turn  at  the  same  rate  as  a.  The  upper  roller 
e  is  loaded  with  a  heavy  weight,  similar  to  the  rollers  a  ;  but  the  other  rollers,  b  and  d, 
are  no  further  loaded  than  the  weight  of  the  rollers. 

The  two  pairs  of  rollers  A,  b,  and  c,  d,  are  mounted  in  separate  frames ;  and  that  frame 
which  contains  the  third  and  fourth  pairs  c,  d,  slides  upon  the  cast-iron  frame  f,  which 
supports  the  machine,  in  order  to  increase  or  diminish  the  distance  between  the  rollers 
B  and  c.  There  is  a  screw/,  by  which  the  frame  of  the  rollers  is  moved,  so  as  to  adjust 
the  machine  according  to  the  length  of  the  fibre  of  the  wool.  The  space  between  b  and 
c  should  be  rather  more  than  the  length  of  the  fibres  of  the  wool.  The  intermediate 
wheels  b  and  c,  are  supported  upon  pieces  of  iron,  which  are  moveable  on  centres ;  the 
centre  for  the  piece  which  supports  the  wheel  6  is  concentric  with  the  axis  of  the  roller 
A ;  and  the  supporting  piece  for  the  wheel  c  is  fitted  on  the  centre  of  the  wheel  d.  By 
moving  these  pieces  the  intermediate  wheels  b  and  c  can  be  always  kept  in  contact,  al- 
though the  distance  between  the  rollers  is  varied  at  times.  By  means  of  this  breaking- 
frame,  the  perpetual  sliver,  which  is  made  up  by  planking  the  sliver  together,  is  equal- 
ized, and  drawn  out  three  times  in  length,  and  delivered  into  the  can  g. 

Drawing-frame. — Three  of  these  cans  are  removed  to  the  drawing-frame,  which  is 
similar  to  the  breaking-frame,  except  that  there  is  no  planking-table  e.  There  are 
five  sets  of  rollers,  all  fixed  upon  one  common  frame  f,  the  breaking-frame,  which  we 
have  described,  being  the  first.  As  fast  as  the  sliver  comes  through  one  set  of  rollers,  it 
is  received  into  a  can,  and  then  three  of  these  cans  are  put  together,  and  passed  again 
through  another  set  of  rollers.  In  the  whole,  the  wool  must  pass  through  the  breaker 
and  four  drawing-frames  before  the  roving  is  begun.  The  draught  being  usually  four 
times  at  each  operation  of  drawing,  and  three  times  in  the  breaking,  the  whole  will  be 
3X4X4X4X4=1 768 ;  but  to  suit  different  sorts  of  wool,  the  three  last  drawing- 
frames  at  5  capable  of  making  a  greater  draught,  even  to  five  limes,  by  changing  the  pin- 
ions ;  acct'dingly  the  draught  will  be  3X4X5X5X5  =  1500  times. 

The  size  of  the  sliver  is  diminished  by  these  repeated  drawings,  because  only  three 
slivers  are  put  together,  and  they  are  drawn  out  four  times ;  so  that,  in  the  whole,  the 
sliver  is  reduced  to  a  fourth  or  a  ninth  of  its  original  bulk. 

The  breaking-frame  and  drawing-frame  which  are  used  when  the  slivers  are  pre- 
pared by  the  combing-machines,  are  differently  constructed ;  they  have  no  planking- 
table,  but  receive  three  of  the  perpetual  slivers  of  the  combing-machine  from  as  many 
tin  cans,  and  draw  them  out  from  ten  to  twelve  times.  In  this  case,  all  the  four 
rollers  contribute  to  the  operation  of  drawing:  thus  the  second  rollers  b,  move  24 
times  as  fast  as  the  rollers  a  ;  the  third  rollers  c,  move  8  times  as  fast  as  a  ;  and  the 
fourth  rollers  £,  move  lOi  times  as  fast  as  a.  In  this  case,  the  motion  is  given  to  the 
different  rollers  by  means  of  bevelled  wheels,  and  a  horizontal  axis,  which  extends 
across  the  ends  of  all  the  four  rollers,  to  communicate  motion  from  one  pair  of  rollers  to 
another. 

There  are  three  of  these  systems  of  rollers,  which  are  all  mounted  on  tne  same 
frame ;  and  the  first  one  through  which  the  wool  passes,  is  called  the  breaking-frame  *; 


ill 

■  -J 


972 


WOOLLEN  MANUFACTURE. 


wh.Vhh  *  'Jiffer  from  the  others,  which  are  called  drawing-frames.     The  slivcn 

which  have  passed  through  one  system  of  rollers,  are  collected  four  or  fiv;  together  an^ 
£1  w^T'^  .'^^  /Irawmg-rollers.    In  all,  the  sliiers  pass  through  tl^ee  drawings'  and 

bvl^ifn^^!'^'^'^^"?  ""^  ^^^  '^^^^"  ^^  fi'^'^^e^*  a  pound  weight  is  talien,  and  is  measured 
by  means  ol  a  cylmder,  in  order  to  ascertain  if  the  drawing  has  been  properly  c#nducted^ 

1^  mendld't^^h.'  "°'  nr  '•  -^^  ^'T^  ^'""^''^^  *^^«^^i«^  '^  ^h«  «i'«  oTworsted  wS 
IS  intended  to  be  spun,  the  pinions  of  some  of  the  drawing-frames  are  changed  to  maW^ 

shver  become  so  small,  that  it  would  break  with  the  slightest  foreland  U  is  th«efo« 

wi«''bntffl^ir„T-^T!;''  !%f  "■"'=''  "''^"',<'  '»»i"S-f™me,  that  a  short  deseriptioB 

fV.™.      t      .V   '  *  '«'.'''"'>'.  ^"hich  are  'aken  ofl'  from  the  spindles  of  the  rovine^ 

rcom,\7^'-  ""''v''"  l."'^'  ^""'  "'  ''"*  "P""  *''««'"*.  »■»'  Ihe  Ling  whieh  proceed 
from  them  is  eonJucted  between  the  rollers.    The  back  pair  turns  rSund  slowly    Se 

middle  pair  turns  about  twice  for  once  of  the  back  rolle  s;  and  the  front  paTm'akeS 

ernr„":h^hTr■^^u^"r "  ""  ""^  '"™  "  '"*  "'"'  ™""'  --"'"^  '»  "•^^»«- «" 

r.J'?^-.''!i"'^^^^  T^'  .'■^''''^''^  ''^''y  ^"'*^^'y  ^'"  t*»e  spinning-frame,  in  order  to  give  the 
^^TlnP^r^^^^^^^  to  the  worsted  The  hardest  twisted  worsted  Is  c2d  tammy 
weight  fhP  w  ?  .^^^  J'^^,l^^^«  ^^orsted  IS  such  as  to  be  20  or  24  hanks  to  the  pound 

tTe  wo'rJted  for  finl  ^.^  •'  ^^  '?•"?  ^"  ?^'^  ^"*^^  ^^  ^^"S^*''  ^he  least  twist  is  given  to 
fromTt    ft  /       ^  hosiery',  which  is  from  18  to  24  hanks  to  the  pound.     The  twist  is 

S^ilkvs  unon  r  ^  H?'^'  7t^  If  ^'"t  °^,  ^^^^'  '^  ^■^-""'^^^'^  »>y  ^^e  size  of  the  wSls  or 
front  ronilcV  ♦t'^K^'.^^l^y,  ^^^  wheel- work  which  communicates  the  motion  to  the 
Iront  rollers  from  the  band-wheel,  which  turns  the  spindles. 

Won^  "fediess  to  enter  more  minutely  into  the  description  of  the  spinning  machinery 
^nder'ci™  "  m/v"''  construction,  invented  by  Sir  Richard  Arkwright,  fu^ll^es  rS 
fwpfn  ,^°™^.M^^^^^^CTURE,  is  equally  applicable   to  worsted.     The   difference  be- 
s  canable  nTV'  "^'-^^  ^"  '^f  distance  between  the  rollers,  which,  in  the  worsted-^rame 
fihrorr  fu     ^^'?"  increased  or  diminished  at  pleasure,  according  to  the  length  of  the 
cotton  '  ^""^  '^'  '^"'"^^' ""'  "'^'""'^°"  ^^  '^^  '«^^"S  is  for  greater  than  in  the 

»  wT"~'^^^,*'°^^'"^  ""/  !^^  spinning-frame  are  placed  in  a  row  upon  wires  before 
a  long  horizontal  reel,  and  the  threads  from  20  bobbins  are  wound  off  togelhe^  The 
reel  is  exactly  a  yard  in  circumference,  and  when  it  has  wound  off  80  turns,  it  rinos  a 
nffu^  ?^K°"  ^5  '\^  '^f  ''  *^^"  «^«PP^^'  ««d  ^  thread  is  passed  round  the  80  ?u'rns 

Jartts  wotd'off  w^'?^-  '?  "'^'-  '^^/-•-g  -  then 'continued  till  anothlr  80 
yaras  is  wound  off,  which  is  also  separated  by  interweaving  the  same  thread  •  each  of 
these  separate  parcels  is  called  a  ley,  and  when  7  such  leys  are  reeled,  it  is  caled  a  hank 
which  contains  560  yards.  When  this  quantity  is  reeled  off,  the  ends  of  the  hS^ 
bread  are  tied  together,  to  bind  each  hank  fast,  and  one  of  the  rails  of  the  reel  is  struck 
to  loosen  the  hanks,  and  they  are  drawn  off  at  the  end  of  the  reel.  The'e  hanks  are 
ZTJa?  "r  ^  ^""'5'  «nd  twisted  up  hard  by  a  stick ;  then  doubled,  and   he  two  parts 

X  1  'f '^""  'IT\'  ^  ^""  ^r^^''    ^"  '^'''  ^^^^^'  '^'  ^«»k«  are^veighed  by  a  smSI 
index  machine,  which  denotes  what  number  of  the  hanks  will  weigh  a  pound  and  ther 

woVT^K  ^''''f'}^'y  into  different  parcels.  It  is  by  this  means  tlfat  thrnumber  of  the 
worsted  IS  asceitained  as  the  denomination  for  its  fineness  :  thus  No.  24  means  that  24 
hanks,  each  containing  560  yards,  will  weigh  a  pound,  and  so  on.  ' 

comaiL  fiSr  «  ^h'""  •  't  ^!f'r'".ln''T  '^^''  "'^  ^"'  ^^"«"'  ^'^^"^^  the  hank  of  cotton 

^me  Pnf,t  '  tK  '  '"*f  ^"^  ""^  ^^ '  **"'  '"^  '^"^^  P'^^^^  the  worsted  hank  is  made  of  the 
same  length  as  the  cotton. 

.  n^?,  ^f"^  "P  i^^  worsted  for  market,  the  proper  number  of  hanks  is  collected  to  make 
a  pound,  according  to  the  number  which  has  been  ascertained  ;  these  are  weighed  as  a 
fn^nfiu  l°""5f  »^««  «^  the  sorting,  then  tied  up  in  bundles  of  one  pound  each,  and 
IZJ  ,-^  ^'""u'?^  are  again  tied  together.  Then  60  such  bundles  are  packed  up  in  • 
sheet,  making  a  bale  of  240  pounds,  ready  for  market.  «*  up  m  • 

not^f  r.!/'*''''T*'  °-^'^''''^  '^^.  -^"i:  '^'  ''^''^^  manufaciure.-Short  wool  resembles  cotton 
thl  .    ;       ""  the  structure  of  its  filaments,  and  is  cleaned  by  the  willy,  as  cotton  is  by 

^liZ'l7'-  ""  '"^  '"'^If.^P  }^^  ""f  ^i'^  ^""'"  °^  ^^^  wool-stapler,  and  cleans  it  from 
accidental  impurities.    Sheep's  wool  for  working  into  coarse  goodJ,  must  be  passed  re- 


iv 


^>j»» 


nl 


WOOLLEN  MANUFACTURE. 


973 


peatedly  through  this  machine,  both  before  and  af\er  it  is  dyed ;  the  second  last  time  for 
the  purpose  of  blending  the  different  sorts  together,  and  the  last  for  imbuing  the  fibres 
intimately  with  oil.  The  oiled  wool  is  next  subjected  to  a  first  carding  operation  called 
tcribblingy  whereby  it  is  converted  into  a  broad  thin  fleece  or  lap,  as  cotton  is  by  the 
breaker-cards  of  a  cotton  mill.  The  woollen  lap  is  then  worked  by  the  cards  proper, 
which  deliver  it  in  a  narrow  band  or  sliver.  By  this  process  the  wool  expands  greatly 
in  all  its  dimensions ;  while  the  broken  or  short  filaments  get  entangled  by  crossing  in 
every  possible  direction,  which  prepares  them  for  the  fulling  operation.  See  Carding, 
under  Cotton  Manufacture. 

The  slvbbing  machine,  or  billy,  reduces  the  separate  rolls  of  cardings  into  a  continuous 
slightly  twisted  spongy  cord,  which  is  sometimes  called  a  roving.    Fig.  1551  is  a  per- 


spective representation  of  the  slubbing  machine  in  most  common  use.  A,  a,  is  the 
wooden  frame  ;  within  which  is  the  moveable  carriage  d,  d,  which  runs  upon  the  lower 
side  rails  at  a,  o,  on  friction  wheels  at  1,  2,  to  make  it  move  easily  backwards  and  for- 
wards from  one  end  of  the  frame  to  the  other.  The  carriage  contains  a  series  of  steel 
spindles,  marked  3,  3,  which  receive  rapid  rotation  from  a  long  tin  drum  f,  by  means  of 
a  series  of  cords  passing  round  the  pulley  or  whorl  of  each  spindle.  This  drum,  6  inches 
in  diameter,  is  covered  with  paper,  and  extends  across  the  whole  breadth  of  the  carriage. 
The  spindles  are  set  nearly  upright  in  a  frame,  and  about  4  inches  apart ;  their  under 
ends  being  pointed  conically,  turn  in  brass  sockets  called  steps,  and  are  retained  in  their 
position  by  a  small  brass  collet,  which  embraces  each  spindle  at  about  the  middle  of 
its  length.  The  upper  half  of  each  spindle  projects  above  the  top  of  the  frame.  The 
drum  revolves  horizontally  before  the  spindles,  having  its  axis  a  little  below  the  line  of 
the  whorls;  and  receives*  motion,  by  a  pulley  at  one  of  its  ends,  from  an  endless  band 
which  passes  round  a  wheel  e,  like  the  large  domestic  wheel  formerly  used  in  spinning 
wool  by  hand,  and  of  similar  dimensions.  This  wheel  is  placed  upon  the  outside  of 
the  main  frame  of  the  machine,  and  has  its  shafts  supported  by  upright  standards  upon 
the  carriage  d.  It  is  turned  by  the  spinner  placed  at  q,  with  his  right  hand  applied  to  a 
winch  R,  which  gives  motion  to  the  drum,  and  thereby  causes  the  spindles  to  revolve 
with  great  velocity. 

Each  spindle  receives  a  soft  cylinder  or  carding  of  wool,  which  comes  through  beneath 
ft  wooden  roller  c,  c,  at  the  one  end  of  the  frame.  This  is  the  billy  roller,  so  much  talked 
of  in  the  controversies  between  the  operatives  and  masters  in  the  cotton  factories,  as  an 
instrument  of  cruel  punishment  to  children,  though  no  such  machine  has  been  used  in 
cotton  mills  for  half  a  century  at  least.  These  woollen  rolls  proceed  to  the  series  of 
spindles,  standing  in  the  carriage,  in  nearly  a  horizontal  plane.  By  the  alternate  advance 
and  retreat  of  the  carriage  upon  its  railway,  the  spindles  are  made  to  approach  to,  and 
recede  from,  the  roller  c,  with  the  effect  of  drawing  out  a  given  length  of  the  soft  cord, 
with  any  desired  degree  of  twist,  in  the  following  manner : — 

The  carding  rolls  are  laid  down  straight,  side  by  side,  upon  the  endless  cloth. 
Strained  in  an  inclined  direction  between  two  rollers,  one  of  which  is  seen  at  b,  and  thf 


i 


974 


WOOLLEN  MANUFACTURE. 


'i! 


^ 


•I 
I' 

'\ 

'     1 

mi 

Other  lies  behind  c.     One  carding  is  allotted  to  »  mm,!!-     ♦!.*., 

one  machine  being  from  50  to  100.     T^  roller  co?^Atwn^^     "'^*^^'  ""^  ~*^'»> 

Its  weight  upon  the  cardings,  while  they  move  onwards  ove   7^J  T''^\  ^f"^^5^  ^^^ 

running  out  of  the  spindle ^cirriage.    llZZiZt^LZX^^ 

horizontal  wooden  rail  or  bar  g,  with  another  bpnpaih    t   lu  Ji  ?"^'^'  ^^^'"^  '^  » 

carding  is  conducted  through  belween  Zse  two  W^.f^       ^"T  '^^  ^''''^^'    ^he 

raised  to  let  any  aliquot  portior^f  the  rSf  pals  fe^^^^^^^^^^  k^''''  '"'  **"^"^ 

down,  it  pinches  the  spongy  carding  fast -whence  thkm..^o-       ?'  *^n  'I  *^»'"  ^«« 

It  is  in  fact  the  clove,  originally  used  bv  Har^rervP.  in  h         ^*"'''"  "  ^*"^  ^^'^  <^^«sp. 

upper  rail  ojs  guided  between  "Hders,'ln^^^ 

from  the  inclined  plane  b,c      There^h  a  s^/rS^^^^^^  ""^J"^'  ^""^'"^^  ^^"^^^ 

of  the  clasp  G,  and  hiude^  i  from  falHn^  tm  If  '•'"^'"w^  ^^^'  ^""'^  «^  ^^«  "PP^^  ^^ 
tance,  and  has  therebralTowed  f"m  "  ?o  g  ^n  Je^^^^^^^^^^  **f-  '"'"^"^  '^  ^  ^«^^^^^"  <"«" 
stop  upon  the  carriage  then  comesTaainst  the  catch  n  ^  'f.l'"^'  '-^  **^  '^•^^"  ««^-  ^ 
upper  rail  to  fall  and  pincrthrcardfnrwhil  fht  ^     ^  withdraws  it ;  thus  allowing  the 

out  or  stretches  that  po'rUon  of  the'r^H  ^.JhTcUs  b'e  w^T^e^rasrandThe^rHf  ^  '^'^"» 
But  during  this  time  the  wheel  has  been  turned  to  keen  tht  .n  nHi  ,  -^'"^^^  P*""*^** 

eating  the  proper  degree  of  twist  to  thp  V^rHinL  ;„  ^  the  spindles  revolving,  communi- 
prevent  them  from  breaking.  "^'  '"  Proportion  to  their  extension,  so  as  to 

It  might  be  imagined  that  the  slubbing  cords  would  hp  •«♦  t^       i         j    i^        . 
but  as  they  proceed  in  a  somewhat  inclined  dTrect'oi  to  the' cl^^^^  ^^'  ^P^"*^!"' 

twisting  motion,  continually  slipping  over  the  noints  of  thi  ?'•  V  ^^^'P  "^'"^^^  * 
wound  upon  them.     Whenever  the  onpnitivp  or  Ti  ,kk     I    ^.  ^P'^^^^^^,  without  getting 

to  the  roWngs,  he  set^  a^urwindinT^erunon^^^^^^^  '^'i  ^''''^  *  "^"^  ^'^'''  ""^  ^^'^^ 
which  purpose  he  presses  dowT^hefaller-wire'^S^^h  hisleft'h  '"i"  '  """'"l^  ^^«P^'  ^°' 
from  the  points  of  {he  spindles,  and  placTit  onnositTto  thlill^-^^!'^' '''.  ^'  S  ^^^'  ''  ^*^^" 
the  spindles  revolve,  whUe  he  pushes  in  the  carH  j!  ^^^"^^^^^^^'e  part.  He  next  makes 
upon  the  spindle  into  a  conical  corThewireTre^u^^^^^  V  '""  V^Vl"l>Wng 

series  of  slubbings  at  once  and  receivpritlmnnc^  ,  V^®  winding-on  of  the  whole 
from  the  horizonral  rail  f  which  tur^^^^^  ^""^?  °^  depression  for  this  purpose 

standards,  which  rise  f  om  7he  carrlg^  B^vTurnii".  tV  '""^-l'  '"  ^'""'f''  fixed  on  the 
may  be  raised  or  lowered  in  an v  decree  THp^^kk^  ^^-^  '*u  ""^  '^^  P^^^^s,  the  wire  8 
to  draw  the  carriagrou^  but  ^n  rfturnin-  ^t  hl^  '  seizes  the  rail  4  in  his  left  hand, 
lime  that  he  pushes  the  cirrt^befS^  ''"'"""  '"  faller-wire,  at  the  same 

^^''^^:^^ 

pulleys,  as  shown  in^ri^re,  rhas  a  heaU  w^^^^^  roller  and  after  passing  over 

weight  at  the  other,  to  kefp  i  tnsta„tfy  ex^te^ed^U^^^^^  ^"^^' 

turn  the  rollers  with  their  endless  clot^  round  In  suVadirfction^^^^^  r"^'  !S 

the  rovmgs,  without  puttin*'  anv  strain  nnnn  tLl      v   a»rection  as  to  bring  forward 

pushed  hom'e,  the  "ar|er  wc%h74ts  Lun^^^  Z^"  ^^?'  ^^^  ^^^^^^^  « 

the  greater  weight  turns  iTe  ro lle'r  anradvan?p;  ?h  J*,'"  ^^^  '^"'"'^^^  ^^  *^^«^^  <>««> 
carding  at  the  skme  rate  Tt^e  carriat  runs  o^^^^^  T""'  ^  *^  '"  '^^"^^^  ^he 

livered,  a  knot  in  the  roprarrives  at  a^xed  Inn  Lv  ».  i"^"  ^^^  P'^'P"  ^"^"^^1^  »s  de- 
further';  while  at  the  same  Sn  the  roller  stuU^lhe'L^^^^^^^  "°?T''  *  V°  '"""^  "^^ 
G,  of  the  clasp  to  fall,  and  pinch  the  Sn^  fas?  the  wW?  t'  VI'  *"r'  ^^^  ^^^^^  '"^ 
makes  the  spindles  revolve  •  and  tL  rSal  k  '•  ^  ,^  ^'  ^'"^  *^^"  ^et  in  motion, 
the  slubbings  whiLuXtW  influence  r^^^^  simultaneously  dmwn  out,  extendi 

operative  m'ust  take  care  to  pu  h  in  "re  cLr7a^^^^^^^  tn?"^'",?  "^u'^f  slubbings,  the 
rates  that  the  spindles  will  not  lake  up  fa  fer^than  thl  p.  ™  ^^'  ""^'^^  ™""^  ***  ^"^^ 
or  he  would  injure  the  slubbings     Thp\Ll!v  ?  carnage  moves  on  its  railway, 

bring  the  carding^Lm  the  cardln«^i  Je  toX^^^^  '^^"''^^  'u^  attendance  of  a  child,  to 
joinlhe  ends  of 'the  ?r^sh  Les  care^^^^^^  ^t^  CendsTfXoth  p'^'^'f  '^^'^'-^^^-^  to 
roller.  Slubbings  intended  for  war^^arn  must  be  mor  °  -c^iiTJ^  ^T"  "/^"  ^^« 
but  each  must  receive  a  degree  of  "r^,^,„  rekt"ve  to  tZLlTH  '*'^"  '^^'S^"''  ""^^'^ 
intended  to  be  made.     In  general   however  no  mnl^  ^T^l^^  of  wool  and  of  the  cloth 

I  may  here  remark,  that  various  machines  have  been  constracted  of  late  year,  fr. 


■^^^ 


WOOLLEN  MANUFACTURE.  975 

making  continuous  card-ends,  and  slubbings,  in  imitation  of  the  carding  and  roving  of 
the  Cotton  Manufacture  ;  to  which  article  I  therefore  refer  my  readers.  The  wool 
slubbings  are  now  spun  into  yarn,  in  many  factories,  by  means  of  the  mule.  Indeed,  I 
have  seen  in  France  the  finest  yarn,  for  the  mousseline-de'laine  fabrics,  beautifully  spun 
upon  the  self-actor  mule  of  Sharp  and  Roberts.* 

rew/mng.— When  the  cloth  is  returned  from  the  fulling-mill  (which  see),  it  is  stretched 
upon  the  tenter-frame,  and  left  in  the  open  air  till  dry. 

In  the  woollen  manufacture,  as  the  cloth  suffers,  by  the  operation  of  the  fulling-miU,  a 
•hrinkage  of  its  breadth  to  well  nigh  one  half,  it  must  at  first  be  woven  of  neadv  double 
Its  intended  width  when  finished.    Superfine  six-quarter  broad  cloths  must  therefore  be 
.    turned  out  of  the  loom  twelve  quarters  wide. 

Burling  is  the  name  of  a  process,  in  which  the  dried  cloth  is  examined  minutely  in  every 
part,  freed  from  knots  or  uneven  threads,  and  repaired  by  sewing  any  little  rents,  or  in- 
serting sound  yarns  in  the  place  of  defective  ones. 

Teasling.— The  object  of  this  operation  is  to  raise  up  the  loose  filaments  of  the 
woollen  yarn  into  a  nap  upon  one  of  the  surfaces  of  the  cloth,  by  scratching  it  either 
with  thistle-heads,  called  teasels,  or  with  teasling-cards  or  brushes,  made  of  wire  The 
natural  teasels  are  the  balls  which  contain  the  seeds  of  the  plant  called  DipsaaufuU 
lorum ;  the  scales  which  form  the  balls  project  on  all  sides,  and  end  in  sharp  elitic 
points,  that  turn  downwards  like  hooks.  In  teasling  by  hand,  a  number  of  these  baUs 
are  put  into  a  small  wooden  frame,  having  crossed  handles,  eight  or  ten  inches  long : 
and  when  thus  filled,  form  an  implement  not  unlike  a  curry-comb,  which  is  used  by 
two  men,  who  seize  the  teasel-frame  by  the  handles,  and  scrub  the  face  of  the  cloth 
hung  m  a  vertical  position  from  two  horizontal  rails,  made  fast  to  the  ceiling  of  the 
workshop.  First,  they  wet  the  cloth,  and  work  three  times  over,  by  strokes  in  the 
direction  of  the  warp,  and  next  of  that  of  the  weft,  so  as  to  raise  all  the  loose 
fibres  from  the  felt,  and  to  prepare  it  for  shearing.  In  large  manufactories,  this 
dressing  operation  is  performed  by  a  machine  called  a  gig-mill,  which  originally  con- 
sisted, and  in  most  places  still  consists,  of  a  cylinder  bristled  all  over  with  the  thistle- 
kaads,  and  made  to  revolve  rapidly  while  the  cloth  is  drawn  over  it  in  a  variety  of 
directions.  If  the  thistle  be  drawn  in  the  line  of  the  warp,  the  points  act  more  eflS- 
caciously  upon  the  weft,  being  perpendicular  to  its  softer  spun  yarns.  Inventors  who 
have  tried  to  give  the  points  a  circular  or  oblique  action  between  the  warp  and  the 
weft,  proceed  apparently  upon  a  false  principle,  as  if  the  cloth  were  like  a  plate  of 
metal,  whose  substance  could  be  pushed  in  any  direction.  Teasling  really  consists  in 
drawing  out  one  end  of  the  filaments,  and  leaving  the  body  of  them  entangled  in  the 
cloth ;  and  it  should  seize  and  pull  them  perpendicularly  to  their  length,  because  in 
Uiis  way  It  acts  upon  the  ends,  which  being  least  implicated,  may  be  most  readily 
disengaged.  ' 

When  the  hooks  of  the  thistles  become  clogged  with  flocks  of  wool,  they  must  be 
taken  out  of  the  frame  or  cylinder,  and  cleaned  by  children  with  a  small  comb.  Moisture 
moreover,  softens  their  points,  and  impairs  their  teasling  powers;  an  effect  which  needs 
to  be  counterbalanced,  by  taking  them  out,  and  drying  them  from  time  to  time  Many 
contrivances  have,  therefore,  been  proposed  in  which  metallic  teasels  of  an  unchan'^eable  na- 
ture, mounted  m  rotatory  machines,  driven  by  power,  have  been  substituted  for  the  vege- 
table,  which  being  required  in  prodigious  quantities,  becomes  sometimes  excessively  scarce 
and  dear  in  the  clothing  districts.  In  1818,  several  schemes  of  that  kind  were  patented  in 
France,  of  which  those  of  M.  Arnold-Merick,  and  of  MM.  Taurin  freres,  of  Elbceuf,  are 
described  in  the  16th  volume  of  Brevets  dUnvention  expires.  Mr.  Daniell,  cloth  manikc- 
turer  in  Wills,  renewed  this  invention  under  another  form,  by  making  his  rotatory  cards 
with  two  kinds  of  metallic  wires,  of  unequal  length  ;  the  one  set,  long,  thin,  and  delicate 
representing  the  points  of  the  thistle;  the  other,  shorter,  stiffer,  and  blunter,  being  in- 
tended to  stay  the  cloth,  and  to  hinder  the  former  from  entering  too  far  into  it.  But  none 
ot  these  processes  have  succeeded  in  discarding  the  natural  teasel  from  the  most  eminent 
manufactories.  *««.» 

The  French  government  purchased,  in  1807,  the  patent  of  Douglas,  an  English  me- 
chanist, who  had,  in  1802,  imported  into  France  the  best  system  of  gig-mills  then  used 
in  the  west  of  England.  A  working  set  of  his  machines  having  been  placed  in  the  Con^ 
ttrvatotre  deserts,  for  public  inspection,  they  were  soon  introduced  into  most  of  the 
l?rench  establishments,  so  as  generally  to  supersede  teasling  (lainage)  by  hand.  A  de- 
scnption  of  them  was  published  in  the  third  volume  of  the  Brevets  d'Inveniion.  The  follow- 
ing IS  an  outline  of  some  subsequent  improvements  : 

1.  As  it  was  imagined  that  the  seesaw  action  of  the  hand  operative  was  in  some  re- 
spects more  effectual  than  the  uniform  rotation  of  a  gig-mill,  this  was  attempted  to  b« 
imitated  by  an  alternating  movement. 

^  U9  thii  admirabla  machiM  fully  dmribed  uid  deUneated  in  my  Ctttom  Manu/aeture  of  Grtat 


976 


WOOLLEN  MANUFACTURE. 


i      !; 


Xi 


i 

m 


♦»f:  ^^^"^  conceived  that  the  seesaw  motion  was  not  essential,  but  that  it  was  advan- 
apous  to  make  the  teasels  or  cards  act  in  a  rectilinear  direction,  ks  in  wo  k  nX  haT* 
his  acfon  was  attempted  by  placing  the  two  ends  of  the  teasel-frame  in  grooves  formed  Hke 

hW  rf/rf'  V^V^";  ^^^«^'  should  act  on  the  cloth  only  when  it  caCInto  tLT fectU. 

lhrcons[rucli^n.  ^'"''  "-^^"^^-maker,  of  Manchester,  obtained  a  patent,  in  1I32,  for 

^J:J\'^^^  supposed  that  the  teasels  should  not  act  perpendicularly  to  the  weft  but 

ed    n  i/lO^T^"''^  rT" J!^'/"^^  '!■  '^^  '^''^'    ^'-  ^^ '^^^ee,  of  Gloucester  pa'tent! 
ed,  m  1830,  a  scheme  of  this  kind,  m  which  the  teasels  are  mounted  upon  two  endless  chains 
which  traverse  from  the  middle  of  the  web  to  the  selvase  or  list,  oneTrthe  rl^ht  Ind 

Z  the  effect  'ol"  ''"t'  ^'^^^  ^*^^.-^'°^'  \'''''  ^^'^'^  ^^^  ^^^^  -^"  such  a  v^lodty^ 
antlefoS^^^^  action,  dividing  into  two  equal  parts  the  reS 

and     ft Tr  t  ■   ^S'^rl ^"^  '""^l^  y Y"'-     ^^'^^  P^^^"^  machines  of  Mr!  George  Old- 
InthTfi^/lVtV  f''^'''^^^^^  inl832-all  proceed  upon  this  prhiciple 

i?n  h  ^'"V  ^^^^f^  ^'^  mounted  upon  discs  made  to  turn  flat  upon  the  surface  of  the 
?ie  cloth  wh-  r- '*^'  "''  'T^""^  ^'''''  ^''  ^'''''^  ^y  corkscrew  spiral  springs  against 
sprinis  'aLTn  thVth'T''^  k^  ^\'^^'''''  «"^hi«">  «1^«  Pressed  igainst' the  discs  by 
turn  lot  fn  1  L^  third  machine,  the  revolving  discs  have  a  larger  diameter,  and  theV 
lurn,  not  m  a  horizontal,  but  a  vertical  plane 

bv^flat^h.'rH  ^"r'''^  '^V^  '"^"f'^  ^'  beneficial  to  support  the  reverse  side  of  the  cloth 
CUseld  Kpi^lf''''  '''^'''  l''\"^.  "P^"^  '^^  ^'^^^  '"^''^  ^^^^«'  or  teasels.  Mr.  Joseph 
hind  ?  mJ  :  r^  f^''^'^  '''S  *=^"'^  "P°"  ^™°°^^  ^^^^1  stones,  teasels  them  by 
?he  bacLMhT;i.Ph  "''f^T'^-^"^  ^"""^  "''^^^"^'^  ^  P*^«"t'  i*^  ^829,  for  supporting 
acLn  6  Ph  J^  with  elastic  surfaces,  while  the  part  was  exposed  to  the  teaslini 
tTons  oV  Mr  Spv  I  M  i  «J?«  l>^^",J"Parted  to  the  teasels,  in  the  three  patent  inven: 
u.Pn,l  to  ci  V  L^':  ^'  F;  ^^"'^"'  ^"^  ^'-  ^-  Atkinson.  7.  It  has  been  thought 
usefu  to  separate  the  teasel-frames  upon  the  drum  of  the  gig-mill,  by  simple  rollers  or 

aLSin'/'^'^  with  steam,  in  order  to  obtain  the  combined  klct  of  caleSng 
and  teaslmg.     Mr.  J.  C.  Darnell,  Mr.  G.  Haden,  and  Mr.  J.  Rayner,  have  obtained 

for  mlin"'  t^-lT"'  '^t  '"^^  ^^J^'  ^'  ^'^'^^^  ^^^"^^^  schemes'have  been  mount^S 
on  t^fsame  ma?h;^e."°'  "'°"  "  '"""  '''^''  ^^'^"  '^''^'  "^  ^"^'^  ^^  "^«""^  *^°  ^^^ 
to^rPVPn^th/r^^^^.-'  ^"""r"/??  ^  ^^'"^  excellent  method  of  stretching  the  cloth,  so  as 

,Wn  J'^  n^  Mr.  Collier,  of  Pans,  obtained  a  patent,  in  1830,  for  a  greitly 
do?Mer«  ^V^h^f  n"^^"  Douglas's  plan,  which  is  now  much  esteemed  by  the  French 
dothiers.     The  following  figures  and  description  exhibit  one  of  the  latest  and  best  teasline 

?pW  "'•  1.^-  V^f  'Vt"'^"".  ^^^-  ^"^^^^  ^"'^  C«"  «f  I^o"viers,  and  is  nov^dofn  '  ex! 
cellent  work  ,n  that  celebrated  seat  of  the  cloth  manufacture.  ° 

its  othlr^fmlll!?'"''"' r^\'^°''"?  "?**  ^"'l"^'"^'  ^^y^"d  thickness,  at  the  expense  of 

n  breadth  TkT?'  ''  ^'"'w'' •"?  I,'''/'^^  '"^"'"^  ^^^^^^  ""'^  ^^^^d  in  length,  and  one  half 

l^H  f.  t   '  »' J  surface  is  diminished  to  one  third  of  its  size  as  it  comes  out  of  the  loom- 

Sv  tea^lint'  tZT"'  '^^''^'^^^^^^^^old  in  thickness.     As  the  filaments  drawn  forth 

with  d  ffpfpn,  h1    ^'^  TT^^  ^'""'^''  '^'y  '""^^  ^  '^^'^  to  make  them  level,  and 
with  diflTerent  degrees  of  closeness,  according  to  the  quality  of  th-  stuff  and  the  an 
pearance  it  is  desired  to  have.    But,  in  general,  a  single  opemt  on  of  each  kind  is  Z 
sufficien  ;  whence,  after  having  passed  the  cloth  once  through  the  4-mill  and  on^ 

h'irthVtf  rnrrnt^suff^'"^""^'  '^  I'  "^'^  ^^^'^^^^  ^  seco\d'?e"^^g,lrp« 
of  these  processes  as  nftp„'  f  •'  ?  ''"T  '^"^''"f'  ?^^"''  ^^  *^«  ^^^^^"^te  fepetition 
aoDearance      S  nf  ih  *'  f-^^""^**  P'^'P^'"'  ^^^  ^^^^^  ^"^"y  acquires  its  wished-foi 

beTconducted    he  cloth  t  "P^^^^'°"f  ^'^  ^^^^  ^^^li^^te,  especially  the  first ;  and  if  the, 

^^S^l^t^t:^^:^^  ''-'-'  ^-^-=-^  --^  species^f  furl^hfct 

upon  a  wrought-iron  shaft  k,  which  hLj .titll^^^t'^nd' (M  T^3)  exterloTto'^ 
frame,  the  usual  riggers,  or  fast  and  loose  oullev  /-j*'  /*  wKf:*.h  -^^  exterior  to  the 
machine  by  a  band  from  the  main  shaft  of  the  mil   ^'£itf  ri^h   end'wifr„  t?  r^  '^* 


—■v 


WOOLLEN  MANUFACTURE. 


977 


II 


578 


WOOLLEN  MANUFACl  (JRE. 


other  two,  towards  its  extremities.  Their  sTzemavh2  •^',  ""f '^i^  ?^  ^^^  ^^^^  r,  and  the 
1552.  After  havingset  them  so  hat  alUhefr  sSs  or'r^^^^^^^  "^'  ^'""^  \"^P^^^'^"  ^^fiS' 
Sides  H,  are  made  fast  to  the  16  portions  of  theTeHnh/  '^'^''Jl^^^Pond  exactly,  the  16 
wheels.  These  sides  are  made  of  sheet^ronr.irv.^^^^^^  '^^''^J'  correspond  in  the  three 

ed  o/f  at  the  end, fig.  1553,  and^ach  J^h^m  IIp;";  \f  "f  ^"""'•^^-  ^•''>^2,  butround! 
three  bolts  h,     The%lastic^art  7tL  plate^ron  a^^^^^^^^    n^-"t  ^^^^'''  '^'^'  ^^^^^^  »> 

i6  frames  bearing  the  teasels  which  are  to  J.,  ^  ^^{"^^^ed,  with  proper  precaution^ 
follows  :_Each  has  the  shape  of  a  rectan^'^^  .^hese  are  fitted  in  as 

but  their  breadth  only  We  enouoh  in  "n^'.  •  *  ^^"^'^  ^^"«*  to  that  of  the  drum, 
thus  making  two  rows  of  Sel  teasels  thr^^^^^^^  th  stle-heads   set  end  to  end 

in  M  1552  )     A  portion  of   ie  Cnt  is  reJe""^^^^^^^  il"/^^'  <«-«  the  contouJ 

a..nst  Which  the  tops  of  the  teasels^^est,  IStl  :::/L:fL^J^-^^^ 

'  ^  '   '-^^^  Ef '  ''^"  ^'.  '^'^  throughout  its  whole 

i  hfi '        '^^'^^'i''^  ^^^  tails  of  the  teasels, 

Avhich  are  seated  and  compressed  in  it.  There 

are,  moreover,  cross-bars  t,  which  serve  to 

^^____^^      maintain  the  sides  of  the  frame  i,  at  an  inva- 

rBWnmTT-      "^^^  d'stance,  and  to  form  short  compart- 

ends  are  fortified  by  stronger  bars  k   k    ^"fJ^^'f^r  ^f.^Pi"f  tjie  thistles  compact.    The 

between  the  ribs.     The  distance  of  th/iwir     r^u^T'""  ^^^'  to  fasten  the  frames 

other  .ee  fil  1^  ^^Sl  :^^-t^^^^  -n  -  ^cli^d  pl.e  of  | 
1555      r=,^  rest  upon  the  flat  parts  of  the  ribs  themselves.    T^i 

fhTl  ?"A'''"'^*^'  '^  ''  "^^^°°«'  that  if  the  ends  of 
Bnf  ^h X  ^^^^OPP^^  the  frame  will  be  made  fasU 
But  ihey  need  not  be  fixed  in  a  permanent  man- 
ner,   because    they    must    be    frequently    removed 

,         f"d  replaced         They  are  fastened   by  the  clainp 

K  i^^'-' .^f  ^'  ^?^)'  ^^hich  is  shut  at  the  one  end  and 

r           i^       ^=^^^         furnished  at  the  other  with  a  spring,  which  can  be 
V J         opened  or  shut  at  pleasure.      2  and  4,  in  fifr.  1553 

the  clamp,^g,.  1555,  1556     The  birTthe  rSffl'"^ -^i^"'^^*  ''>'^^«^^  theplaceof 

X?i& '  ''^P^  is'th^nttirn  ?r  tt^eAthtl^Tam?^  ^^^"^^'  ''  '^^^^"^ 

be  requisiel^these  successive  drcu^^^  the  other  as  many  times  as  sh^' 

under  certain  condit?oL.""lT"rdeTo"L^Wperl7?  ailed'  tt'must  V  ^'^  ^^"^^^? 
tension  throughout  its  whole  breadth  durin<?  its  traverfp  \>  "'f  V^^u^  ^\  ^^'''*' 
more  or  less  close  contact  with  thp  Hr,,r«   «   "«  traverse ;    it  must  be  brought  into 

the  stage  of  the  oyrTtlot ;"  1  JfJsTintTJa^  "'^^T  ''  ^'^  ^^^^''-'^^^ 

embracing  a  ereater  or  smaller  nnrtl!In  .r  -.1  *     /angent  to  the  surface,  and  somet  mes 

speed,  deJendanruLn  the  veToc^t^^^^^^^^  '''"'°7'  'f  T'^  ^''^^^^  ^'th  a  determinate 

result:  themachiTi?self  mus^mlk/th^^^^^  and  calculated  so  as  to  produce  the  best 

the  other.  '"''''  "^^^^  ^^^  "'"^  P^^^  alternately  from  one  winding  beam  to 

collet  /',  and  top  collet  T,  in  th?  proL^o  h'e  str  c'herT'ut'n ''tht'  "^^'t 
shaft  are  mounted—  .  a  bevel  whppl  r'.  9  on  „™  i.  .  •  .  '  ^P""  ""'  "Pnght 
3.  a  lower  bevel  pinionV  wi  uTts  hn«  »'  Ti  l"^^'  .''T'  .P'"'""  "'  ''"'' »"  •>»«'  «'; 
L,  and  con,mu„ica!e MoT;  tie  moveme„rif  rl  atinrt^'V"?.'-'  "  ^"^^  "P""  ""'  '""« 
/.with  which  it  is  in  war  •  LttheT?n^nV,I.vi,  •'"''''  '«  ««ives  from  the  pkia 
drum,  ,».rticipates  in  t^e  rotation  whicr.h{s  "hi^rZ^vTf  """.".  'heshaftFirf^ 

rrati';rs^fi.trr^j,{;  -:  «r  te^^^^^^ 

^.  i.  mav  be  tu'^ned  -J^^^^^^l^iZ^  f^  ^ ^teS^S^' 


■RHMVir^ 


WOOLLEN  MANUFACTURE. 


979 


its  bottom,  and  which  may  be  rendered  active  or  not,  at  pleasure ;  these  curved  teeth, 
and  their  intervals,  correspond  to  similar  teeth  and  intervals  upon  the  top  of  the  boss 
M',  which  is  dependent,  by  feathered  indentations,  upon  the  rotation  of  l,  though  it  cmn 
slide  freely  up  and  down  upon  it.  When  it  is  raised,  therefore,  it  comes  into  gear  with 
M.  The  pinion  k,  and  its  boss,  have  a  similar  mode  of  being  thrown  into  and  out  of  gear 
with  each  other.  The  bosses  m'  and  n',  ought  always  to  be  moved  simultaneously,  is 
orler  to  throw  one  of  them  into  gear,  and  the  other  out  of  gear.  The  shaft  l  serves  to 
put  the  cloth  in  motion,  by  means  of  the  bevel  wheels  p"  and  q",  upon  the  ends  of  the 
beams  p,  q,  which  take  into  the  pinions  m  and  n. 

The  mechanism  destined  to  stretch  the  cloth  is  placed  at  the  other  end  of  the 
machine,  where  the  shafts  of  the  beams  p,  q,  are  prolonged  beyond  the  frame,  and  bear 
at  their  extremities  p'  and  q',  armed  each  with  a  brake.  The  beam  p  {fig.  1552),  turns 
in  an  opposite  direction  to  the  drum ;  consequently  ihe  cloth  is  wound  upon  p,  and 
unwound  from  q.  If,  at  the  same  time  as  this  is  going  on,  the  handle  r',  of  the  brake- 
shaft,  be  turned  so  as  to  clasp  the  brake  of  the  pulley  Q',and  release  that  of  the  pulley  p  , 
it  is  obvious  that  a  greater  or  smaller  resistance  will  be  occasioned  in  the  beam  q,  and 
the  cloth  which  pulls  it  in  unwinding,  will  be  able  to  make  it  turn  only  when  it  has 
acquired  the  requisite  tension;  hence  it  will  be  necessary,  m  order  to  increase  or 
diminish  the  tension,  to  turn  the  handle  r'  a  little  more  or  a  little  less  in  the  direction 
which  clasps  the  brake  of  the  pulley  q'  ;  and  as  the  brake  acts  in  a  very  equable  manner, 
a  very  equable  tension  will  take  place  all  the  time  that  the  cloth  takes  to  pass.  Besides, 
should  the  diminution  of  the  diameter  of  the  beam  Q,  render  the  tension  less  eflScacious 
in  any  considerable  degree,  the  brake  would  need  to  be  undamped  a  very  little,  to  re- 
store the  primitive  tension.  ^ 

When  the  cloth  is  to  be  returned  from  the  beam  p,  to  the  beam  q,  z  must  be 
lowered,  to  put  the  shaft  l  out  of  gear  above,  and  in  gear  below ;  then  the  cloth-beam 
q,  being  driven  by  that  vertical  shaft,  it  will  turn  in  the  same  direction  as  the  drum,  and 
will  wind  the  cloth  round  its  surface.  In  order  that  it  may  do  so,  with  a  suitable  tension, 
the  pulley  q'  must  be  left  free,  by  clasping  the  brake  of  the  pulley  p',  so  as  to  oppose  an 
adequate  resistance. 

The  cloth  is  brought  into  more  or  less  close  contact  with  the  drum  as  follows  : — There 
is  for  this  purpose  a  wooden  roller  t,  against  which  it  presses  in  passing  from  the  one 
winding  beam  to  the  other,  and  which  may  have  its  position  changed  relatively  to  the 
drum.  It  is  obvious,  for  example,  that  in  departing  from  the  position  represented  in 
fig,  1552,  where  the  cloth  is  nearly  a  tangent  to  the  drum,  if  the  roller  t'  be  raised, 
the  cloth  will  cease  to  touch  it ;  and  if  it  be  lowered,  the  cloth  will,  on  the  contrary, 
embrace  the  drum  over  a  greater  or  less  portion  of  its  periphery.  For  it  to  produce 
these  eflTects,  the  roller  is  borne  at  each  end,  by  iron  gudgeons,  upon  the  heads  of  an 
arched  rack  t"  {fig.  1552),  where  it  is  held  merely  by  pins.  These  racks  have  the  same 
curvature  as  the  circle  of  the  frame,  against  which  they  are  adjusted  by  two  bolts  ;  and 
by  means  of  slits,  which  these  bolls  traverse,  they  may  be  slidden  upwards  or  down- 
wards, and  consequently  raise  or  depress  the  roller  t.  But  to  graduate  the  movements, 
and  to  render  them  equal  in  the  two  racks,  there  is  a  shaft  u,  supported  by  the  uprights 
of  the  frame,  and  which  carries,  at  each  end,  pinions  u',  u",  which  work  into  the  two 
racks  t',  t"  ;  this  shaft  is  extended  in  front  of  the  frame,  upon  the  side  of  the  head  of  the 
machine  {fig.  1553),  and  there  it  carries  a  ratchet  wheel  tt,and  a  handle  u'.  The  work- 
man, therefore,  requires  merely  to  lay  hold  of  the  handle,  and  turn  it  in  the  direction  of 
the  ratchet  wheel,  to  raise  the  racks,  and  the  roller  t,  which  they  carry ;  or  to  lift  the 
click  or  catch,  and  turn  the  handle  in  the  opposite  direction,  when  he  wishes  to  lower  the 
roller,  so  as  to  apply  the  cloth  to  a  larger  portion  of  the  drum. 

CLOTH  CROPPING. 

Of  machines  for  cropping  or  shearing  woollen  cloths,  those  of  Lewis  and  Davis  have 
been  very  generally  used. 

Fig.  1557  is  an  end  view,  and^g.  1558  is  a  side  view,  of  Lewis's  machine  for  shearing 
cloth  from  list  to  list.  Fig  1559  is  an  end  view  of  the  carriage,  with  the  rotatory  cutter  de- 
tached from  the  frame  of  the  machine,  and  upon  a  larger  scale ;  a,  is  a  cylinder  of  metal, 
on  which  is  fixed  a  triangular  steel  wire ;  this  wire  is  previously  bent  round  the  cylinder 
in  the  form  of  a  screw,  as  represented  at  a,  a,  in  fig.  1557,  and,  being  hardened,  is  intended 
10  constitute  one  edge  of  the  shear  or  cutter. 

The  axis  of  the  cylindrical  cutter  a,  turns  in  the  frame  6,  which,  having  proper  ad- 
justments, is  mounted  upon  pivots  c,  in  the  standard  of  the  travelling  carriage  rf,  d  ;  and 
«,  is  the  fixed  or  ledger  blade,  attached  to  a  bar  /,  which  constitutes  the  other  edge  of 
the  cutter;  that  is,  the  stationary  blade,  against  which  the  edges  of  the  rotatory  cutter  act ; 
/  and  g,  are  flat  springs,  intended  to  keep  the  cloth  (shown  by  dots)  up  against  the 
cutting  edges.    The  form  of  these  flat  springs  /,  g,  is  shown  at  figs,  1560  and  1561, 

84 


980 


WOOLLEN  MANUFACTURE. 


as  consisting  of  pJates  of  thin  metal  cut  into  narrow  slips  I  fig.  1560)  or  Derfor«t«I 
with  long  holes  {fig,  1561.)  Their  object  is  to  support  the  ciofh,  which  Ts  intendSlu 
pass  between  them,  and  operate  as  a  spring  bed,  bearing  the  surface  of  the  cloth  against 

the  cutters,  so  that  its 
pile  or  nap  may  be 
cropped  off  or  shorn  as 
the  carriage  d  is  drawn 
along  the  top  rails  of 
the  standard  or  frame 
of  the  machine  fc,  A,  by 
means  of  cords. 

The  piece  of  cloth 
to  be  shorn,  is  wound 
upon  the  beam  fr,  and 
its  fnd  is  then  con- 
ducted through  the 
machine,  between  the 
flat  springs  /  and  g  f  is 
shown  in  fig.  1559),  to 
the  other  beam  /,  and  is 

.'. ~ —^ _i__».  then    made     fast;     the 

sides  or  lists  of  ihe  cloth  being  held  and  stretched  by  'small  hooks,  called  habiting 
hooks.     The  cloth  being  thus  placed  in  the  machine,  and  drawn  tight,  is  held  dis- 


J 

vl560 

^^— >^ 

1559 


1561 


(  i 


tended  by  means  of  ratchets  on  the  ends  of  the  beams  k  and  /,  and  palls.     In  ccfmmenc- 
ing  the  operation  of  shearing,  the  carriage  d,  must  be  brought  back,  as  in  fig.  1559,  so 

that  the  cutters  shallbe  close  to 
the  list ;  the  frame  of  the  cutters 
is  raised  up  on  its  pivots  as  it 
recedes,  in  order  to  keep  the 
cloth  from  injury,  but  is  low- 
ered again  previously  to  being 
put  in  action.  A  band  or  winch 
is  applied  to  the  rigger  or  pul- 
ley m,  which,  by  means  of  an 
endless  cord  passed  round  the 
pulley  n,  at  the  reverse  end  of 
the  axle  of  m,  and  round  the 
other  pulleys  o  and  p,  and  the 
small  pulley  g,  on  the  axle  of 
the  cylindrical  cutter,  gives  the 
cylindrical  cutter  a  very  rapid 
rotatory  motion;  at  the  same 
time  a  worm,  or  endless  screw, 
on  the  axle  of  m  and  n,  taking 
into  the  teeth  of  the  large  wheel  r,  causes  that  wheel  to  revolve,  and  a  small  drum  *, 
upon  its  axle,  to  coil  up  the  cord,  by  which  the  carriage  d,  with  the  cutters  o  and  e,  and 
the  spring  bed  /  and  g,  are  slowly,  but  progressively,  made  to  advance,  and  to  carry  the 
cutters  over  the  face  of  the  cloth,  from  list  to  list ;  the  rapid  rotation  of  the  cutting  cylin- 
der a,  producing  the  operation  of  cropping  or  shearing  the  pile. 

Upon  the  cutting  cylinder,  between  the  spiral  blades,  it  is  proposed  to  place  stripes  cf 
plush,  to  answer  the  purpose  of  brushes,  to  raise  ihe  Eap  or  pile  as  the  cylinder  gotff 
around,  and  thereby  assist  in  bringing  the  points  of  the  wool  up  to  the  cutters. 
The  same  contrivance  is  adapted  to  a  machine  for  shearing  the  cloth  lengthwise. 


mmmmmtm 


mm^ 


^^ifsY^ 


WOOLLEN  MANUFACTURE. 


981 


Fig,  1562,  is  a  geometrical  elevation  of  one  side  of  Mr.  Davis's  machine.  Fig.  1563, 
a  plan  or  horizontal  representation  of  the  same,  as  seen  in  the  top;  and  fig.  1564,  a  sec- 
tion taken  vertically  across  the  machine  near  the  middle,  for  the  purpose  of  display- 
ing the  working  parts  more  perfectly  than  in  the  two  preceding  figures.  These 
three  figures  represent  a  complete  machine  in  working  condition,  the  cutters  being 
worked  by  a  rotatory  motion,  and  the  cloth  so  placed  in  the  carriage  as  to  be  cut  from 
list  to  list,  a,  a,  a,  is  a  frame  or  standard,  of  wood  or  iron,  firmly  bolted  together  by 
cross  braces  at  the  ends  and  in  the  middle.    In  the  upper  side-rails  of  the  standard. 


there  is  a  series  of  axles  carrying  anti-friction  wheels  6,  6,  6,  upon  which  the  side-rails 
c,  c,  of  the  carriage  or  frame  that  bears  the  cloth  runs,  when  it  is  passing  under 
the  cutters  in  the  operation  of  shearing.  The  side-rails  c,  c,  are  straight  bars  of  iron, 
formed  with  edges  r,  on  their  under  sides,  which  run  smoothly  in  the  grooves  of  the 
fillers  b,  b,  b.    These  side-rails  are  firmly  held  together  by  the  end  stretchers  d,  d. 


The  sliding  frame  has  attached  to  it  the  two  lower  rollers  c,  e,  upon  which  the  cloth 
intended  to  be  shorn  is  wound ;  the  two  upper  lateral  rollers/,/,  over  which  the  cloth  is 
conducted  and  held  up ;  and  the  two  end  rollers  g,  g,  by  which  the  habiting  rails  h,h,  are 
imwa  tight. 

In  preparing  to  shear  a  piece  of  cloth,  the  whole  length  of  the  piece  is,  in  the  first 
place,  tightly  rolled  upon  one  of  the  lower  rollers  e,  which  must  be  something  longer 
than  the  breadth  of  the  cloth  from  list  to  list.  The  end  of  the  piece  is  then  raised, 
and  passed  over  the  top  of  the  lateral  rollers  /,  /,  whence  it  is  carried  down  to  the 
other  roller  c,  and  its  end  or  farral  is  made  fast  to  that  roller.  The  hooks  of  the  ha- 
biting rails  hf  A,  are  then  put  into  the  lists,  and  the  two  lower  rollers  e,  e,  with  the  two 
end  rollers  g,  g,  are  then  turned,  for  the  purpose  of  drawing  up  the  cloth,  and  straining 
it  tight,  which  tension  is  preserved  by  ratchet  wheels  attached  to  the  ends  of  the  re- 
spective rollers,  with  palls  dropping  into  their  teeth.  The  frame  carrying  the  cloth  is 
now  slidden  along  upon  the  top  standard  rails  by  hand,  so  that  the  list  shall  be  brought 


982 


WOOLLEN  MANUFACTURE. 


WOOLLEN  MANaFACTURE. 


983 


learly  up  o  the  cutter  i,  i,  ready  to  commence  the  shearing  operation ;  the  bed  is  then 

raised,  which  brings  the  cloth  up  against  the  edges  of  the  shears.  '   "*^  ^  "  ^Hea 

Ihe  construction  of  the  bed  will  be  seen  by  reference  to  the  cross  section,/^.  1564. 

1564  ft  consists  of  an 

iron     or     other 
metal  roller  k,  k, 
turned  to  a  truly 
cylindricalfigure, 
and  covered  with 
cloth  or  leather, 
to  afford  a  smaU 
degree   of   elas. 
ticily.  This  roller 
is  mounted  upon 
pivots  in  a  frame 
/,  /,  and  is  suppor- 
ted by  a  smaller 
roller»n,similarly 
mounted,  which 
roller  m,  is  in- 
tended merely  to 
prevent         any 
bending    or  de- 
pression of    the 

\e:^zv,f::zt'^i^r ''''  ^'^  ^^^^^  ^^^^  ^  ^^^^^^  ^^-  contacrw!t?\hr;u 

In  order  to  allow  the  bed  k  to  rise  and  fall,  for  the  purpose  of  bringing  the  cloth  uo  to 
km?/  7  'va'  '^^'"J  °;  ^""^^""^  ''  ^^^y  ^'•^"^  '^^^  af^e^  the  oper\t"L,  the  frame^/  I 

wirn  ,h  ']'^V%^u^  ^^r  ^"  '^^  ^'^^'^  ^^^"^^'•d  »»'  »»>  the  moveable  part  encLsed 
wi  hm  the  standard  being  shown  by  dots.  This  standard  n,  is  situated  about  he  mddle 
of  the  mach.ne,  crossing  it  immediately  under  the  cutters,  and  is  made  fast  to  he  fr^me  a 
by  bolts  and  screws  There  s  a  lever  o,  attached  to  the  lower  cross-rail  of  the  sLndar J 
tie  .PntrnfT"  ,^^"^^7°»-P^"'  t\^  -^tremity  of  the  shorter  arm  of  which  lever  acts  under' 
the  centre  of  the  slidmg-frame,  so  that  by  the  lever  o,  the  sliding.frame,  with  the  bed  mav 
be  raised  or  lowered,  and  when  so  raised,  be  held  u^  by  a  spring  catch  j.  '       ^ 

.  ni  r"'\!;°'^  explained  by  what  means  the  bed  which  supports  the  cloth  is  constructed 
^"1  Tf  "^'  '°  ^'.*^  ^'"P.*^"  *^'«^^  '^  "^^^'^  e°»t«ct  wilh  the  cutters,  whirtheopS^.' 
of  the  cutTL^^^^^  "V  'I ''  "I'^'^^T  '"^  '^«  "^^^  ^'^'^  t«  describe'the  constructron 

in  he  firl  th;^"  fi       '  '^^^  ""^  '^'''^'''^ '  ^^^  ^^'^h  purpose,  in  addition  to  what  is  show, 
in  ^g!  1565!         ^'"'^''  '  ^'^  ^^^  represented  detached,  and  upon  a  larger  scale. 

In  this  figure  is  exhibited  a  portion  of  the  cutters  in  the  same  situation  as  in  fig- 
'IM_"'  p\  rrC=^^^  1565  ^  ^^  1559  ;  and  alongside  of  it  is  a  section  of 
i  lilhvNSi;'!'         /^^^=^         T  ^^  »^^^m      the    same,  taken   through  it  at  right 

angles  to  the  former ;  ;>,  is  a  metallic 
bar  or  rib,  somewhat  of  a  wedge  form, 
which  is  fastened  to  the  top  part  of  the 
rri     1  •    1.  .  ,  standard  a,  a,  seen  best  in  He.   1558 

To  this  bar  a  straight  blade  of  steel  g,  is  attached  by  screws,  the  edge  of  which  stands 
forward  even  with  the  centre  or  axis  of  the  cylindrical  cutter  f,  and  forms  the  ledger  blade. 
^'^kT,!'  ^m^^  ^^^^  ""^c^^^  '^*^'''-  "^his  blade  remains  stationary,  and  is  in  close  contac 
wiUi  the  pile  or  nap  of  the  cloth,  when  the  bed  k  is  raised,  in  the  manner  above  described. 
The  cutter  or  upper  blade  of  the  shears  is  formed  by  inserting  two  or  more  strips  of 
plate  steel  r,r,  in  twisted  directions,  into  grooves  in  the  metallic  cylinder  «,  t,  the  edges 
o  which  blades  r,  as  the  cylinder  t  revolves,  traverse  along  the  edge  of  the  fixed  or  ledger 
b  ade  g  and  by  their  obliquity  produce  a  cutting  action  like  shears ;  the  edses  of  the  two 
blades  taking  hold  of  the  pile  or  raised  nap,  as  the  cloth  passes  under  it,  shaves  off  the 
superfluous  ends  of  the  wool,  and  leaves  the  face  smooth. 

Rotatory  motion  is  given  to  the  cuttin?  cylinder  »,  by  means  of  a  band  leading  from  the 
wheel  s  which  passes  round  the  pulley  fixed  on  the  end  of  the  cylinder  t,  the  wh?el  *  being 
driven  by  a  band  leading  from  the  rotatory  part  of  a  steam-engine,  or  any  other  first  mover, 
and  passed  round  the  rigger  /,  fixed  on  the  axle  «.  Tension  is  given  to  this  band  by  a 
Ughtening  pulley  «  mounted  on  an  adjustable  sliding-piecer,  which  is  secured  to  the  stand- 
ard  l)y  a  screw;  and  this  rigger  is  thrown  in  and  out  of  gear  by  a  clutch-box  and  lever,  which 
sets  the  machine  going,  or  stops  it. 

In  order  to^ive  a  drawing  stroke  to  the  cutter,  which  will  cause  the  piece  of  cloth 
ID  be  shorn  off  with  better  effect,  the  upper  cutter  has  a  slight  lateral  action,  produced 


Vt  the  axle  of  the  cutting  cylinder  being  made  sufficiently  long  to  allow  of  »ts  sbding 
laterally  about  an  inch  in  its  bearings ;  which  sliding  is  effected  by  a  cam  tc,  fixed  at 
one  end.  This  cam  is  formed  by  an  oblique  groove,  cut  round  the  axle  (see  «',  ^g.  15b&;, 
and  a  tooth  ar,  fixed  to  the  frame  or  standard  which  works  in  it,  as  the  cylinder  revolves. 
By  means  of  this  tooth,  the  cylinder  is  made  to  slide  laterally,  a  distance  equal  to  the 
obUquity  of  the  groove  w,  which  produces  the  drawing  stroke  of  the  upper  shear,  in 
order  that  the  rotation  of  the  shearing  cylinder  may  not  be  obstructed  by  fncUon,  the 
tooth  X,  is  made  of  two  pieces,  set  a  little  apart,  so  as  to  afford  a  small  degree  of  elasticity. 

The  manner  of  passing  the  cloth  progressively  under  the  cutters  is  as  follows:— Un 
the  axle  of  the  wheel  «,  and  immediately  behind  that  wheel,  there  is  a  small  rigger,  from 
which  a  band  passes  to  a  wheel  y,  mounted  in  an  axle  turning  in  bearings  on  the  lower 
tide-rail  of  the  standard  a.  At  the  reverse  extremity  of  this  axle,  there  is  another  smaU 
rieeer  1,  from  which  a  band  passes  to  a  wheel  2,  fixed  on  the  axle  3,  which  crosses  near 
the  middle  of  the  machine,  seen  in  yig.  1564.  Upon  this  axle  there  is  a  sliding  pulley  4, 
round  which  a  cord  is  passed  several  times,  whose  extremities  are  made  fast  to  the  ends 
of  the  sliding  carriage  d;  when,  therefore,  this  pulley  is  locked  to  the  axle,  which  »s  done 
by  a  clutch  box,  the  previously  described  movements  cf  the  machine  cause  the  pulley  4 
to  revolve,  and  by  means  of  the  rope  passed  round  it,  o  draw  the  frame,  with  the  cloth, 
slowly  and  progressively  along  under  the  cutters.  .,    ,r    ,• 

It  remains  only  to  point  out  the  contrivance  whereby  the  machinery  throws  itselt  out 
of  gear,  and  stops  its  operations,  when  the  edge  of  the  cloth  or  list  arrives  at  the  cutters. 

At  the  end  of  one  of  the  habiting  rails  /i,  there  is  a  stop  affixed  by  a  nut  and  screw  o, 
which  by  the  advance  of  the  carriage,  is  brought  up  and  made  to  press  against  a  lever 
6-  when  an  arm  from  this  lever  6,  acting  under  the  catch  7,  raises  the  catch  up,  and 
allows  the  hand-lever  8,  which  is  pressed  upon  by  a  strong  spring,  to  throw  the  clutch- 
box  10  out  of  gear  with  the  wheel  8 ;  whereby  the  evolution  of  the  machine  instanUy 
ceases'  The  lower  part  of  the  lever  6,  being  connected  by  a  joint  to  the  top  of  the  lever 
i  the  receding  of  the  lever  6,  draws  back  the  lower  catch  j,  and  allows  the  sliding  frame 
L /,  within  the  bed  fc,  to  descend.  By  now  turning  the  lower  rollers  e,  e,  another  portion 
of  the  cloth  is  brought  up  to  be  shorn ;  and  when  it  is  properly  habited  and  strained,  by 
the  means  above  described,  the  carriage  is  slidden  back,  and,  the  parts  being  all  throw:* 
into  gear,  the  operation  goes  on  as  before.  ^       ^.  ^  v 

Mr.  Hirst's  improvements  in  manufacturing  woollen  cloths,  for  which  a  patent  was  o^. 
tained  in  February,  1830,  apply  to  that  part  of  the  process  where  a  permanent  lustre  M 
fiven  usually  by  what  is  called  roll-boiling;  that  is,  stewing  the  cloth,  when  tighUy 
wound  upon  a  roller,  in  a  vessel  of  hot  water  or  steam.  As  there  are  many  disadvanta- 
ges attendant  upon  the  operation  of  roll-boiling,  such  as  injuring  the  cloths,  by  over- 
heating them,  which  weakens  the  fibre  of  the  wool,  and  also  changes  some  colors,  he 
substituted,  in  place  of  it,  a  particular  mode  of  acting  upon  the  cloths,  by  occasional  or 
intermitted  immersion  in  hot  water,  and  also  in  cold  water,  which  operations  may  be  per- 
formed either  with  or  without  pressure  upon  the  cloth,  as  circumstances  may  require. 

The  apparatus  which  he  proposes  to  employ  for  carrying  on  his  improved  process,  is 
shown  in  the  accompanying  drawing.     JPig.  1566,  is  a  front  view  of  the  apparatus,  com- 


plete, and  in  working  order;  jig.  1567,  is  a  section,  taken  transversely  through  the  mid- 
dle of  the  machine,  in  the  direction  of  yig.  1568 ;  and  yig.  1568,  is  an  end  view  of  the 
tame  •  a,  a,  a,  is  a  vessel  or  tank,  made  of  iron  or  wood,  or  any  other  suitable  material : 
•lopii^  at  the  back  and  front,  and  perpendicular  at  the  enfis.    This  tank  must  be  sufll- 


984 


WOOLLEN  MANUFACTURE. 


cicnlly  large  to  admit  of  half  the  diameter  of  the  cylinder  or  drum  h  h  k  w^-      •  ^ 

into  it,  which  drum  is  about  four  feet  diameter,  and  ab^uts"?feenn;^*"^  immtnB(t 
more  than  the  width  of  the  piece  of  cloth  intended  to  Se  operateSt^^^^^^^ 

or  drum  b,  b,  is  construct- 
ed by  combining  segments 
of  wood  cut  radially  on 
their  edges,  secured  by 
screw-bolts  to  the  rims  of 
the  iron  wheels,  having 
arms,  with  an  axle  pass- 
ing through  the  middle. 

The  cylinder  or  drum 
being  thus  formed,  ren- 
dered smooth  on  its  pe- 
riphery, and  mounted  up- 
on its  axle  in  the  tank, 
the  piece  of  cloth  is 
wound  upon  it  as  tightly 
as  possible,  which  is  done 
by  placing  it  in  a  heap 
upon  a  stool,  as  at  c.  Jig, 
1567,  passing  its  end  over 

jx^llers  d  e,  and  then  securing  it  to  the  drum,  the  cloth  is  progTefsllTeM^^awn  ^mthe' 

toV^V^\sllZ?^r//7^"^^  ?"^'-  '"'V^  ''^""  ^"^  P"^^  ^^^«^>»t »«  "«w  filled 
10  me  brim,  as  shown  at  fig.  1567,  and  opening  the  stop-cock  of  the  pipe  /,  which  leads 

*■  ^[on^  a  boiler,  the  steam  is  allowed  to  blow 

through  the  pipe,  and  discharge  itself  at 
the  lower  end,  by  which  means  the  tem 
perature  of  the  water  is  raised  in  the  tank 
to  about  170°  Fahr.     Before  the  tempera- 
ture of  the  water  has  got  up,  the  drum  is 
set  in  slow  rotatory  motion,  in  order  that 
the  cloth  may  be  uniformly  heated  through- 
out ;  the  drum  making  about  one  rotation 
per  minute.     The  cloth,  by  immersion  in 
the  hot  water,  and  passing  through  the 
cold  air,  in  succession,  for  the  space  of 
about  eight  hours,  gets  a  smooth  soft  face, 
the  texture  not  being  rendered  harsh,  or 
otherwise  injured,  as  is  frequently  the  case 
by  roll-boiling. 

Uniform  rotatory  motion  to  the  drum  is 
shown  in  fig.  1566,  in  which  g  is  an  end- 
less  screw  or  worm,  placed  horizontally, 
first  mover  employed  in  the  factorv  Th!^  ^n^ut  T^"^  ^f  f  steam-engine  or  any  other 
drives,  the  verU  wheel  I  u  rthel  o7  wtL'^c  tlL^tx^'^' ^  5  '^ 
consequently,  continually  revolves  with  it  At  the  end  ^thoT?;  r  \ ''  '/  ^""^^  ^"'^^ 
of  sliding  clutches  fc,  fc,  are  mounted whiih  when  nrolr-^S  r  *"  f  the  drum,  a  pair 
in  fig.  1566,  produce  the  coupling  or  irkin-  Tf  the  drZ  «h  J^i;'^^*!;'^' r. '•^'^^'^  ^^  ^°^» 
Which  the  drum  is  put  ia  motion ;  buton  withdrawing  tt^nf^  ^  ^  u  t'T^  ^'^"'^'  ^^ 
ling-box  f,  ,-,  as  in  L  figure,  the'  drrrmreSy'^sfaid's  s  m    '^  ^'  ^'  '""  ^'^  ^^"^ 

After  operating  upon  the  cloth  in  the  way  described  hv^lcl*  •»  .u 
for  the  space  of  time  required,  the  hot  wrter  is  o  be  withir^rK^  '^  through  hot  water 
•r  otherwise,  and  cold  water  rntroducerinto  tL  tank^n^l  Z^  ^  '°\^.  ^i  ^he  bottom, 
the  cloth  is  to  be  continued  turning,  in  the  manner  ^wl/  ''  ^i!J^'''^  .^^^^  ^^^^'- 
twenty-four  hours,  which  will  perfect!^  fix  tL  Se  thatch?  ^/^"^i;  ^^'^!  l^^*'"  «' 
quired  by  its  immersion  in  the  hot  water,  and  leave  the  nieorn«n  f^^^V^""'^  .^^'  *^ 
silky  state.  '  ^  P"^  ^^  "»P>  to  the  touch,  m  a  soft 

beLVpJe'dTl^^^^^^^^^^  roller  ,  which, 

over  the  back  of  the  cloth  as  it  goes  round.    T^7Z\:fL'''::!'.'l  ttVn"l2f 


WOOLLEN  MANUFACTURE. 


985 


doth  with  any  required  pressure,  bv  depressing  the  screws  m,  m,  or  by  the  employ- 
ment of  weighted  levers,  if  that  should  be  thought  necessary. 

Pressing  ia  the  last  finish  of  cloth  to  give  it  a  smooth  level  surface.  The  piece  is 
folded  backwards  and  forwards  in  yard  lengths,  so  as  to  form  a  thick  package  on  the 
board  of  a  screw  or  hydraulic  press.  Between  every  fold  sheets  of  glazed  paper  are 
placed  to  prevent  the  contiguous  surfaces  of  the  cloth  from  coming  in  contact;  and  at 
the  end  of  every  twenty  yards,  three  hot  iron  plates  are  inserted  between  the  folds,  the 
plates  being  laid  side  bv  side,  so  as  to  occupy  the  whole  surface  of  the  folds.  Thin 
sheets  of  iron  not  heated  are  also  inserted  above  and  below  the  hot  plates  to  moderate 
the  heat  When  the  packs  of  cloth  are  properly  folded,  and  piled  in  sufficient  number 
in  the  press,  they  are  subjected  to  a  severe  compression,  and  left  under  its  influence  till 
the  plates  get  cold.  The  cloth  is  now  taken  out  and  folded  again,  so  that  the  creases 
of  the  former  folds  may  come  opposite  to  the  flat  faces  of  the  paper,  and  be  removed 
hj  a  second  pressure.  In  finishing  superfine  cloths,  however,  a  very  slight  pressure  is 
given  with  iron  plates  but  moderately  warmed.  The  satiny  lustre  and  smoothness 
given  by  strong  compression  with  much  heat  is  objectionable,  as  it  renders  the  surface 
apt  to  become  spotted  and  disfigured  by  rain. 

Ross's  patent  improvements  in  wool-combing  machineri/,  March  13,  1851.  — The  first 
improvements  described  have  relation  to  the  machine  for  forming  the  wool  into  sheets 
of  a  nearly  uniform  thickness,  technically  known  as  the  "sheeter,"  and  consist  chiefly 
in  combining  with  the  ordinary  sheeting  drum  or  cylinder  rollers,  designated,  from  their 
resemblance  to  porcupine  quills,  porcupine  rollers;  these  rollers  having  their  teeth  or 

auills  set  in  rows,  and  the  rows  of  one  roller  gearing  or  taking  into  the  spaces  between 
le  rows  of  the  other. 
JPig.  1569  is  an  elevation  of  a  sheeting  machine  thus  constructed:  —  f  r  is  the  gen- 


eral frame  work  upon  which  the  several  working  parts  of  the  machine  are  mounted. 
A  is  the  main  or  sheeting  drum  or  cylinder,  which  is  studded  with  rows  of  comb  or 
"porcupine  "  teeth  a,  a,  o,  the  length  and  fineness  of  which  are  varied  according  to 
the  length  of  the  staple  of  the  wool  or  other  material  to  be  operated  upon.  Instead  of 
the  rows  consisting  each  of  a  single  set  of  teeth,  two,  three,  or  more  sets  may  be  com- 
bined together.  The  number  of  wires  which  may  be  placed  on  one  line  should  vary 
with  the  quality  of  the  wool  or  other  material.  In  long  staple  machines,  the  number 
may  vary  from  four  to  ten  or  more,  and  in  short  staple  machines  from  five  to  twenty 
and  more  perinch.  b,  b,  are  two  fluted  feed-rollers,  c,  c,  two  porcupine  combing  rol- 
ler^ by  which  the  wool  is  partly  combed  while  passing  from  the  feed  rollers  to  the 
surface  of  the  sheeting  drum ;  an  end  elevation  of  the  porcupine  combing  rollers  on  an 
enlarged  scale  is  given  at  fig.  1570.  The  teeth  c,  c,  are  set  in  rows,  and  the  rows  of 
one  roller  take  or  gear  into  the  spaces  between  the  rows  of  the  other,  d  is  a  grooved 
guide  roller  for  preventing  the  wool  or  other  material  escaping  the  combing  action. 
The  wool  or  other  material  is  laid  by  the  attendant  evenly  upon  the  upper  surface 
of  an  endless  webb  g,  which  works  over  the  under  feed  rollers,  and  a  plain  roller  h, 
which  18  mounted  in  bearings  on  the  front  of  the  machine.  The  feed  rollers  gradually 
supply  the  wool  thus  spread  upon  the  endless  web  to  the  two  porcupine  combing  rol- 
lers, where  it  is  partly  combed  and  separated,  and  being  so  prepared,  it  is  laid  hold 
Of  by  the  teeth  of  the  sheeting  drum,  by  which  it  is  still  further  drawn  out  on  account 
of  the  greater  velocity  with  which  the  surface  of  the  sheeting  drum  travels.    When  a 


'M: 


986 


WOOLLEN  MANUFACTURE. 


sufficient  quantity  of  the  wool  or  other  material  has  been  thus  collected  on  the  sur- 
face of  the  drum,  it  is  removed  by  the  attendant  passing  a  hooked  rod  across  the  sur- 
fiaoe  of  the  drum,  and  raising  up  one  end  of  the  sheet,  when  the  whole  may  be  easily 
stripped  off  and  removed,  being  then  in  a  fit  state  for  being  supplied  to  the  comb-filline 
machine,  next  to  be  described.  ° 

A  modification  of  this  sheeting  machine  is  represented  in^^s.  167 1, 16Y2,  which  differs 


from  it  m  this,  that  it  is  fed  from  both  ends.  In  this  modification  a  double  set  of  feed- 
ing rollers  is  employed,  so  that  the  machine  may  be  fed  from  both  ends.  These  rollers 
are  grooved  and  gear  into  porcupine  combing  rollers  similar  to  those  before  described 
which  are  followed  by  brush  cylinders  or  grooved  guide  rollers,  a  is  the  sheeting  drum 
as  before;  B,  b,  the  fluted  feed-rollers,  c,  c,  the  porcupine  combing  rollers,  which  gear  into 
the  fluted  ones;  d,  d,  are  the  grooved  guide  rollers;  f,  k,  are  brush  cylinders,  which 
may  in  case  of  long  work  be  dispensed  with;  g,  g,  are  the  endless  webs  upon  which 
the  wool  is  laid.  The  framing  and  gearing  by  which  the  several  parts  are  put  in  mo- 
tion are  oinitted  m  the  drawings,  for  the  purpose  of  clearly  exhibiting  the  more  impor- 
tant working  parts  of  the  machine.  The  arrangement  of  sheeting  machines  just  de- 
scribed, in  so  far  as  regards  the  employment  of  a  fluted  feed  roller  in  conjunction  with 
a  porcupine  combing  roller,  and  grooved  guide  roller,  is  more  especially  applicable  to 
sheeting  fine  short  wool,  but  may  also  be  applied  with  advantage  to  wool  or  other  ma- 
tenal  of  a  longer  staple.  In  the  case  of  fine  short  wool,  the  sheet  may  be  drawn  off 
by  means  of  rollers,  in  the  manner  represented  in/^.  1672  :  h,  a  are  the  drawing  or 
straightening  rollers,  and  i  the  receiving  rollers.  During  the  operation  of  drawing  the 
wool  and  winding  it  on  the  receiving  roller,  the  sheeting  cylinder  must  have  a  motion 
imparted  to  it  m  the  reverse  direction. 

The  next  head  of  Mr.  Ross's  specification  embraces  several  improvements  in  comb- 
HlJing  machines,  which  have  for  their  common  object  the  partial  combing  of  the  wool 
while  it  18  in  the  course  of  being  filled  into  the  combs.  We  select  for  exemplification 
What  the  patentee  regards  as  the  best  of  these  arrangements:/^.  1678  is  aside  elevation 
of  a  comb-fillmg  machine  as  thus  improved,    a,  a,  is  a  skeleton  drum,  which  is  composed 


WORSTED  MANUFACTXJRE. 


987 


of  two  rings  a  a,  afiixed  to  the  arms  b  b,  which  last  are  mounted  upon  the  main  shaft 
of  the  machine,  which  has  its  bearings  upon  the  general  frame  f,  f;  b1,  b2  are  the  por- 
cupine combing  rollers,  and  ci,  c2  brushes  by  which  the  porcupine  combing  rollers 
cleansed  from  the  wool  that  collects  upon  them,  and  by  which  the  wool  is  again  de- 
livered to  the  combs  e,  e  ;  i>,  d,  are  the  feed-rollers,  and  e  an  endless  web  which  runs 
over  the  lower  feed-roller  and  the  plain  roller  g,  which  is  situated  at  the  front  of  the 
machine;  h,  h,  are  the  driving  pulleys,  by  which  the  power  is  applied  to  the  machine, 
and  I,  I,  I,  the  wheel  gearing  by  which  motion  is  communicated  to  the  different  parts. 
The  wool  which  has  undergone  the  process  of  sheeting  in  the  machine  first  described  is 
spread  upon  the  endless  web  k,  and  in  passing  between  the  feed-rollers,  and  between  or 
under  or  over  the  porcupine  combing  rollers,  is  taken  hold  of  by  the  combs  e,  e,  as  they 
revolve,  and,  being  drawn  under  the  first  porcupine  roller  fil  and  the  brush  ci,  the 
continued  revolution  of  the  drum  and  combs  causes  the  wool  to  be  brought  into  contact 
with  the  other  porcupine  combing  roller  b2  and  brush  c2.  As  the  combs  get  filled, 
the  wool  is  thus  continuously  being  brought  under  the  action  of  the  porcupine  combing 
rollers  and  brushes;  and  each  new  portion  of  the  wool  taken  up  is  instantly  combed 
out  For  some  purposes  the  combing  will  be  found  carried  so  far  by  this  operation  that 
the  wool  will  require  no  further  preparation  previous  to  being  formed  into  slivers  in  the 
machine  just  described,  and  which  is  calculated  for  filling  the  combs  and  combing  the  wool 
or  other  fibrous  material,  when  the  staple  is  some  considerable  length  (say  from  4  to 
16  inches),  there  are  two  porcupine  comb  rollers  with  their  brushes  employed;  but  I 
do  not  confine  myself  to  that  number,  as  in  some  cases  a  single  porcupine  combing  roller 
and  brush  will  be  found  sufficient  for  the  purpose  of  facilitating  the  process  of  combing 
and  filling  the  combs;  three  or  more  rollers  and  brush  cylinders  may  be  used  with  ad- 
vantage ;  such  as  where  the  staple  is  short,  or  where  the  fibrous  material  operated  upoa 
is  very  close,  and  separated  with  difficulty. 

Mr.  Ross  next  describes  some  improvements  in  the  combing  machine  of  his  invention 
patented  in  1841,  and  now  extensively  used.  The  following  general  description  will 
indicate  with  sufficient  distinctness  to  those  familiar  with  the  machine,  the  nature  of 
the  improvements. 

"First.  I  give  to  the  saddle  combs  in  the  said  machine  a  compound  to-and-fro  and 
up-and-down  movement,  whereby  they  recede  from  and  advance  towards  the  comb 
gates,  and  simultaneously  therewith  alternately  rise  and  fall,  so  that  each  time  the 
comb  gates  pass  the  saddle  combs,  they  do  so  in  a  different  plane,  and  thus  the  position 
of  the  combs  in  relation  to  each  other,  as  well  as  to  the  hold  they  take  of  the  wool  or 
other  material,  is  constantly  being  changed.  Secondly,  I  employ  a  fan  to  lash  the 
wool  in  the  comb  gate  or  flying  comb  up  against  the  saddle  comb,  which  renders  it  im- 
possible for  the  wool  to  pass  by  the  saddle  comb  without  being  acted  upon  by  it. 
Thirdly,  I  attach  the  springs  by  which  the  gates  are  actuated  to  the  lower  arms  of  the 
combing  gates,  instead  of  their  being  placed  parallel  to  the  upright  shaft  of  the  machine 
as  formerly,  whereby  a  considerable  gain  in  space  and  compactness  is  effected ;  and, 
fourthly,  I  use  brakes  to  prevent  the  sudden  jerk  which  is  caused  when  the  wool  in  the 
comb  gate  leaves  its  hold  of  the  saddle  comb  or  incline  plane,  and  also  to  counteract 
the  sudden  recoil  of  the  springs  by  which  the  comb  gates  are  pressed  in  when  these 
springs  are  released  from  the  grip  or  pressure  of  the  incline  plane." 

Mr.  Ross  concludes  with  a  description  of  an  improved  method  of  heating  the  combe 
which  has  for  its  object  "the  economizing  of  fuel,  the  better  heating  of  the  comb%  and 


mmf^mm^ 


988 


YEAST. 


the  prevention  of  mistake  in  removing  the  combs  before  they  have  been  a  sufficient 
time  exposed  to  the  heat" 

The  body  of  the  heating  box  or  stove  is  divided  by  a  partition  into  two  portions, 
which  communicate  together  at  the  back  or  further  end  of  the  stove,  so  that  the  flame 
and  heated  vapors,  after  having  circulated  under  and  along  the  sides  of  the  two  lower 
comb  chambers,  ascend  into  the  upper  portion  of  the  stove,  where  they  have  to  traverse 
along  the  sides  and  over  the  top  of  the  two  upper  chambers,  ultimately  escaping  into 
the  chimney  through  a  pipe.  The  length  of  the  heating  box,  or  the  chambers,  should 
be  about  double  the  length  of  the  comba  The  cold  combs  are  inserted  at  one  end,  and 
on  being  put  into  their  places  push  the  more  heated  combs  towards  the  other  end  of 
the  chambers,  from  which  they  are  removed. 

WOOTZ,  is  the  Indian  name  of  steel. 

WORSTED  and  WOOLLEN  MANUFACTURR  812,500  people  employed;  pro- 
ducmg  an  annual  value  of  £26,000,000.  Dewsbury  is  famous  for  tearing  up  old  worn 
cloth  and  working  the  woollen  stuff  into  new  goods  of  a  cheap  description. 

Alpaca  is  an  animal  of  the  Llama  tribe,  inhabiting  the  mountain  region  of  Peru. 
The  wool  or  hair  is  of  various  shades  of  black,  white,  gray,  brown,  Ac,  and  is  remark- 
able for  brightness  of  lustre,  great  length  of  staple,  and  extreme  softness.  This  wool 
was  brought  into  general  use  in  this  country  about  16  years  ago,  by  the  Earl  of  Derby. 
Since  that  time  the  various  obstacles  in  the  way  of  its  successful  working  have  been 
overcome,  and  the  alpaca  manufacture  now  ranks  as  one  of  the  most  important  branches 
of  the  Bradford  worsted  stuff  trade.  The  articles  produced  from  alpaca  in  combination 
with  silk  are  especially  noticeable  for  their  softness  and  brilliancy.  The  bulk  of  the 
goods,  however,  is  made  with  cotton  warp,  and  when  dyed  and  finished  approach  in 
lustre  to  silk.  The  following  is  the  average  yearly  importation  of  alpaca  wool  into 
England  since  its  first  introduction,  viz. : 

_  Annual. 

From  1836  to  1840  -  -  -  -      7,000  bales 

1841       1845  ....     13,000 

1846       1860  ....    20,000 

being  supposed  to  be  the  ultimate  limit  of  the  Peruvian  production. 

Mohair  or  goat's  wool  is  produced  exclusively  in  Asia-Minor.  In  its  raw  state  it  is 
6uj)erior  m  lustre  to  alpaca,  and  it  is  wrought  into  many  beautiful  fabrics.  The  impor- 
tation of  this  article  has  increased  from  5,621  bales  in  1841  to  12,884  in  1850. 

WORT,  is  the  fermentable  infusion  of  malt  or  grains.    See  Beer,  and  Malt. 

WOULFE'S  APPARATUS,  is  a  series  of  vessels,  connected  by  tubes,  for  the 
purpose  of  condensing  gaseous  products  in  water.  See  Acetic  Acid,  M  1 ;  also 
MuKiATio  Aom. 


X. 

^  XANTHINE,  is  the  name  given  by  Kuhlmann  to  the  yellow  dying  matter  contoined 
in  madder. 


T. 

YEAST,  is  the  froth  of  fermenting  worts.    See  Beer  and  FERMEXTATioif. 

Dr.  Liidersdorff  supports  the  theory  that  yeast  is  an  organic  body,  and  acts  by  means 
of  its  organs  on  sugar,  in  contradistinction  to  the  theories  of  its  action  by  mere  contact, 
or  by  Its  own  state  of  decomposition  inducing  a  similar  state  in  the  saccharine  solution 
by  the  following  experiment:— 

A  portion  of  yeast  was  rubbed  between  ground  glass  plates  until  the  globules,  of 
which  It  js  composed,  could  no  longer  be  distinguished  by  the  microscope,  and  its  organic 
structure  therefore  was  destroyed.  An  equal  portion  was  exposed,  moistened  in  a  thin 
layer  to  the  air,  whilst  the  other  was  being  thus  treated.  Both  portions  were  now 
mixed  separately  with  equal  quantities  of  grape  sugar,  dissolved  in  10  parts  of  water 
and  exposed  to  a  temperature  of  95^  F.  The  portion  containing  the  uninjured  yeast 
began  to  ferment  in  half  an  hour,  and  continued  to  do  so  until  the  whole  of  the  sugar 
was  decomposed.  The  mutilated  yeast  did  not  produce  a  single  gas  bubble  in  the  fluid 
containing  it  during  the  whole  of  this  time. 

YEAST  ARTIFICIAL.  Mix  two  parts,  by  weight,  of  the  fine  flour  of  pale 
barley  malt  with  one  part  of  wheat  flour.    Stir  60  pounds  of  this  mixture  gra- 


ZIMOME. 


989 


dually  into  100  quarts  of  cold  water,  with  a  wooden  spatula,  till  it  forms  a  smooth 
pap.  Put  this  pap  into  a  copper  over  a  slow  fire  ;  stir  it  well  till  the  temperature  rise 
to  fully  155°  to  160°,  when  a  partial  formation  of  sugar  will  take  place,  but  this  sweet- 
ening must  not  be  pushed  too  far;  turned  out  the  thinned  paste  into  a  flat  cooler,  and 
Btir  it  from  time  to  time.  As  soon  as  the  wort  has  fallen  to  59°  Fahr.,  transfer  it  to 
a  tub,  and  add  for  every  50  quarts  of  it,  1  quart  of  good  fresh  beer-yeast,  which  will 
throw  the  wort  into  brisk  fermentation  in  the  course  of  12  hours.  This  preparation 
will  be  good  yeast,  fit  for  bakers'  and  brewers'  uses,  and  will  continue  fresh  and  active 
for  three  days.     It  should  be  occasionally  stirred. 

When  beer-barm  has  become  old  and  flat,  but  not  sour,  it  may  be  revived  by  mixing 
with  every  quart  of  it  a  small  potato,  boiled,  peeled,  and  rubbed  down  into  a  paste. 
The  mixture  is  to  be  placed  in  a  warm  situation,  where  it  will  speedily  show  its 
renewed  activity,  by  throwing  up  a  froth  upon  its  surface.  It  must  be  forthwith 
incorporated  with  the  dough,  for  the  purpose  of  baking  bread.  When  the  barm  has 
become  sour,  its  acid  should  be  neutralised  with  a  little  powdered  carbonate  of  soda, 
and  then  treated  as  above,  when  it  will,  in  like  manner,  be  revived-  A  bottle  of  brisk 
small  beer  may  furnish  ferment  enough  to  form,  in  this  way,  a  supply  of  good  yeast 
for  a  small  baking. 

The  German  yeast  imported  into  this  country  in  large  quantities,  and  employed  by 
our  bakers,  in  baking  cakes,  and  other  fancy  bread,  is  made  by  putting  the  unterhefe 
(see  Beer,  Bavarian)  into  thick  sacks  of  linen  or  hempen  yarn,  letting  the  liquid  part, 
or  beer,  drain  away ;  placing  the  drained  sacks  between  boards,  and  exposing  them  to 
a  graduallly  increasing  pressure,  till  a  mass  of  a  thin  cheesy  consistence  is  obtained. 
This  cake  is  broken  into  small  pieces,  which  are  wrapped  in  separate  linen  cloths; 
these  parcels  are  afterward  enclosed  in  waxed  cloth,  for  exportation.  The  yeast  cake 
may  also  be  rammed  hard  into  a  pitched  cask,  which  is  to  be  closed  air-tight.  In 
this  state,  if  kept  cool,  it  may  be  preserved  active  for  a  considerable  time.  When  this 
is  to  be  used  for  beer,  the  proportion  required  should  be  mixed  with  a  (Quantity  of 
worts  at  60°  Fahr.,  and  the  mixture  left  for  a  little  to  work,  and  send  up  a  lively  froth; 
when  it  is  quite  ready  for  adding  to  the  cooled  worts  in  the  fermenting  back. 

Yeast,  Patent.  Boil  6  ounces  of  hops  in  3  gallons  of  water  3  hours :  strain  it  off. 
and  let  it  stand  10  minutes;  then  add  half  a  peck  of  ground  malt,  stir  it  well  up,  and 
cover  it  over;  return  the  hops,  and  put  the  same  quantity  of  water  to  them  again, 
boiling  them  the  same  time  as  before,  straining  it  off  to  the  first  mash ;  stir  it  up,  and 
let  it  remain  4  hours,  then  strain  it  off,  and  set  it  to  work  at  90°,  with  3  pints  of  patent 
yeast;  let  it  stand  about  20  hours;  take  the  scum  off  the  top,  and  strain  it  through 
a  hair  sieve ;  it  will  be  then  fit  for  use.  One  pint  is  sufficient  to  make  a  bushel  of 
bread. 

YELLOW  DYE.  (Tehiture  jauney  Fr. ;  Gelhfarhen,  Germ.)  Annotto,  dyer^s-broom^ 
(GenUta  tinctoria^)  fuslic,  fustet,  Persian  or  French  berries,  quercitron  barky  saw-wort, 
(Strratula  tincforia,)  turmeric,  weld,  and  willow  leaves,  are  the  principal  yellow  djes 
of  the  vegetable  kingdom  ;  chromatc  of  lead,  iron-oxyde,  nitric  acid,  (for  silk,)  sulphurei 
of  antimony,  and  sulphuret  of  arsenic,  are  those  of  the  mineral  kingdom.  Under  these 
articles,  as  also  under  Calico-printing,  Dyeing,  and  Mordants,  ample  instructions 
will  be  found  for  communicating  this  color  to  textile  and  other  fibrous  substances. 
Alumina  and  oxyde  of  tin  are  the  most  approved  bases  of  the  above  vegetable  dyes.  A 
nankin  dye  may  be  given  with  bablah,  especially  to  cotton  oiled  preparatory  to  the  Turkey 
red  process.     See  Madder. 

YELLOW,  KING'S,  is  a  poisonous  yellow  pigment.    See  Arsenic  and  Orpiment. 

YTTRIA,  is  a  rare  earth,  extracted  from  the  minerals  gadolinite  and  yttrolantalite^ 
being  an  oxyde  of  the  metal  yttrium. 


z. 

ZAFFRE.     See  Cobalt. 

ZEDOARY,  is  the  root  of  a  plant  which  grows  m  Malabar,  Ceylon,  &c.  It  occurs 
in  wrinkled  pieces,  externally  ash-colored,  internally  brownish-red ;  possessed  of  a  fra- 
grant odor,  somewhat  resembling  camphor ;  and  of  a  pungent,  aromatic,  bitterish  taste. 
It  contains,  according  to  Bucholz,  1*42  of  volatile  oil,  of  a  burning  camphorated  taste; 
3*60  of  a  soflt,  bitter,  aromatic  resin;  11*75  of  a  bitter  aromatic  extract,  mixed  with  a 
little  resin  and  potash-salts  ;  4*5  of  gum  ;  9  of  vegetable  mucilage ;  3'60  of  starch  ; 
8*0  of  a  starchy  extract  from  the  woody  fibre,  by  means  of  caustic  potassa,  along  with 
31*2  of  another  matter,  12-89  of  woody  fibre,  and  15  of  water.  According  to  Morin, 
this  root  contains,  besides,  an  azotized  substance,  analogous  to  the  extract  of  beef. 

ZIMOME,  is  a  principle  supposed  by  Taddei  to  exist  in  the  gluten  of  wheat-flour. 
Its  identity  is  not  recognised  by  later  chemists. 


1 


990 


ZINC. 


ZINC,  is  a  metal  of  a  blnish-white  color,  of  considerable  lustre  when  brok^ 
across,  but  easily  tarnished  by  the  air;  its  fracture  is  hackly,  and  foliated  with  small 
facets,  irregularly  set.  It  has  little  cohesion,  and  breaks  in  thin  plates  before  the  ham- 
mer, unless  it  has  been  previously  subjected  to  a  regulated  process  of  lamination,  at  the 
temperature  of  from  220°  to  300°  F.,  whereby  it  becomes  malleable,  and  retains  its  mal- 
leability and  ductility  afterwards.  On  this  singular  property,  a  patent  was  taken  out  by 
Messrs.  Hobson  and  Sylvester,  of  Sheffield,  many  years  ago,  for  manufacturing  sheet  zinc^ 
for  covering  the  roofs  of  houses,  and  sheathing  ships  ;  but  the  low  price  of  copper  at  that 
time,  and  its  superior  tenacity,  rendered  their  patent  ineffective.  The  specific  gravity  of 
zinc  varies  from  6-9  to  7'2,  according  to  the  condensation  it  has  received.  It  melts 
under  a  red  heat,  at  about  the  680th  or  700th  degree  of  Fahrenheit's  scale.  When  ex- 
posed to  this  heat  with  contact  of  air,  the  metal  takes  fire,  and  burns  with  a  brilliant 
bluish-white  light,  while  a  few  flocculi,  of  a  woolly-looking  white  matter,  rise  out  of  the 
crucrble,  and  float  in  the  air.  The  result  of  the  combustion  is  a  white  powder,  formerly 
called  flowers,  but  now  oxyde  of  zinc;  consisting  of  34  of  metal,  and  8  of  oxygen,  being 
their  respective  prime  equivalents ;  or,  in  100  parts,  of  81  and  19. 

The  principal  ores  of  zinc  are,  the  sulphuret  called  blende,  the  silicate  called  calamine, 
and  the  sparry  calamme,  or  the  carbonate. 

1.  Blende  crystallizes  in  the  garnet-dodecahedron ;  its  fracture  is  highly  conchoidalj 
lustre,  adamantine ;  colors,  black,  brown,  red,  yellow,  and  green ;  transparent  or  trans- 
lucent; specific  gravity,  4.  It  is  a  simple  sulphuret  of  the  metal;  and,  therefore,  con- 
sists, in  its  pure  state,  of  34  of  zinc,  and  16  of  sulphur.  It  dissolves  in  nitric  acid,  with 
disengagement  of  sulphureted  hydrogen  gas.  It  occurs  in  beds  and  veins,  accompanied 
chiefly  by  galena,  iron  pyrites,  copper  pyrites,  and  heavy  spar.  There  is  a  radiated 
variety  found  at  Przibram,  remarkable  for  containing  a  large  proportion  of  cadmium. 
Blende  is  found  in  great  quantities  in  Derbyshire  and  Cumberland,  as  also  in  Cornwall. 

2.  Calaminey  or  silicate  of  zinc,  is  divided  into  two  species ;  the  prismatic  or  electric 
calamine,  and  the  rhomboidal ;  though  they  both  agree  in  metallurgic  treatment.  The 
first  has  a  vitreous  lustre,  inclining  to  pearly;  color,  white,  but  occasionally  blue, 
green,  yellow,  or  brown ;  spec.  grav.  3-38.  It  often  occurs  massive,  and  in  botroidal 
shapes.  This  species  is  a  compound  of  oxyde  of  zinc  with  silica  and  water ;  and  its 
constituents  are— zinc  oxyde,  66-37;  silica,  26-23;  water,  7-4;  in  100  parts.  Reduced 
to  powder,  it  is  soluble  in  dilute  sulphuric  or  nitric  acid,  and  the  solution  gelatinizes 
on  cooling.  It  emits  a  green  phosphorescent  light  before  the  blowpipe.  The  second 
species,  or  rhombohedral  calamine,  is  a  carbonate  of  zinc.  Its  specific  gravity  is  4*442, 
much  denser  than  the  preceding.  It  occurs  in  kidney-shaped,  botroidal,  stalactitic,  and 
other  imitative  shapes ;  surface  generally  rough,  composition  columnar.  Massive,  with 
a  granular  texture,  sometimes  impalpable;  strongly  coherent.  According  to  Smith- 
son's  analysis,  Derbyshire  calamine  consists  of— oxyde  of  zinc,  65-2 ;  carbonic  acid,  34*8  r 
which  coincides  almost  exactly  with  a  prime  equivalent  of  the 'oxyde  and  acid,  or  42  -i 
22  =  64.  '  >  -r 

The  mineral  genus  called  zinc-ore,  or  red  oxyde  of  zinc,  is  denser  than  either  of  the 
above,  its  spec.  grav.  being  5*432.  It  is  a  compound  of  oxyde  of  zinc  88,  and  oxyde  of 
iron  and  manganese  12.  It  is  found  massive,  of  a  granular  texture,  in  large  quantities, 
in  several  localities,  in  New  Jersey.  It  is  set  free  in  several  metallurgic  processes,  and 
occurs  crystallized  in  six-sided  prisms  of  a  yellow  color,  in  the  smelting-works  of  Koenig- 
shutte  in  Silesia,  according  to  Mitscherlich. 

The  zinc  ores  of  England,  like  those  of  France,  Flanders,  and  Silesia,  occur  in  two 
geological  localities. 

The  first  is  in  veins  in  the  carboniferous  or  mountain  limestone.  The  blende  and  the 
calamine  most  usually  accompany  the  numerous  veins  of  galena  which  traverse  that 
limestone ;  though  there  are  many  lead  mines  that  yield  no  calamine ;  and,  on  the  other 
hand,  there  are  veins  of  calamine  alone,  as  at  Matlock,  whence  a  very  considerable 
quantity  of  this  ore  is  obtained. 

In  almost  every  point  of  England  where  that  metalliferous  limestone  appears,  there 
are  explorations  for  lead  and  zinc  ores.  The  neighborhood  of  Alston-moor  in  Cumber- 
land, of  Castleton  and  Matlock  in  Derbyshire,  and  the  small  metalliferous  belt  of  Flint- 
shire, are  peculiarly  marked  for  their  mineral  riches.  On  the  north  side  of  the  last  county, 
calamine  is  mined  in  a  rich  vein  of  galena  at  Holywell,  where  it  presents  the  singular  ap- 
pearance of  occurring  only  in  the  ramifications  that  the  lead  vein  makes  from  east  to  west, 
and  never  in  those  from  north  to  south ;  while  the  blende,  abundantly  present  in  this 
mine,  is  found  indiflferently  in  all  directions. 

The  second  locality  of  calamine  is  in  the  magnesian  limestone  formation  of  the 
English  geologists,  the  alpine  limestone  of  the  French,  and  the  zechstein  of  the 
Germans.  The  calamine  is  disseminated  through  it  in  small  contemporaneous  veins, 
which,  running  in  all  directions,  form  the  appearance  of  network.  These  veins  have 
commonly  a  thickness  of  only  a  few  inches ;  but  in  certain  cases  they  extend  to  four  fec^ 


ZINC. 


991 


in  consequence  of  the  union  of  several  small  ones  into  a  mass.  The  explorations  of 
calamine  in  the  magnesian  limestone,  are  situated  chiefly  on  the  flanks  of  the  Mend ip 
Hills,  a  chain  which  extends  in  a  northwest  and  southeast  direction,  from  the  canal 
of  Bristol  to  Frome.  The  calamine  is  worked  mostly  in  the  parishes  of  Fhipham 
and  Roborough,  as  also  near  Rickford  and  Broadfield-Doron,  by  means  of  a  great  multi- 
tude of  small  shafts.  The  miners  pay,  for  the  privilege  of  working,  a  tax  of  II.  sterling 
per  annum  to  the  Lords  of  the  Treasury ;  and  they  sell  the  ores,  mixed  with  a  considera- 
ble quantity  of  carbonate  of  lime,  for  11.  per  ton,  at  Phipham,  after  washing  it  slightly  in 
a  sieve.  They  are  despatched  to  Bristol,  where  they  receive  a  new  washmg,  in  order  to 
separate  the  galena. 

OF  THE  SMELTING  OF  THE  ORES  OF  ZINC. 

The  greater  part  of  the  zinc  works  are  situated  in  the  neighborhood  of  Birmingham 
and  Bristol.  The  manufacture  of  brass,  which  has  been  long  one  of  the  staple  articles 
of  these  towns,  was  probably  the  cause  of  the  introduction  of  this  branch  of  industry, 
at  the  period  when  brass  began  to  be  made  by  the  direct  union  of  copper  with  metallic 
zinc,  instead  of  calamine.  A  few  zinc  furnaces  exist  also  in  the  neighborhood  of 
Sheffield,  amid  the  coal-pits  surrounding  that  town.  Bristol  and  Birmingham  derive 
their  chief  supply  of  ores  from  the  Mendip  Hills  and  Flintshire ;  and  Sheffield,  from 

Alston-moor.  .         ....      ,  .       i  •     j  v  r      •♦    • 

The  calamine,  freed  from  the  galena  by  sorting  with  the  hand,  is  calcined  before  its  m- 
troduction  into  the  smelting-furnaces,  by  being  exposed,  coarsely  bruised,  in  reverberalory 
ovens,  10  feet  long,  and  8  broad,  in  a  layer  6  inches  thick.  In  some  esUblishments  the 
calcination  is  omitted,  and  the  calamine,  broken  into  pieces  about  the  size  of  a  pigeon  s 
egg,  is  mixed  with  its  bulk  of  small  coal. 

Zinc  is  smelted  in  England,  likewise  from  blende,  (sulphuret  of  zinc.)  This  ore, 
after  being  washed,  and  broken  into  pieces  of  the  size  of  a  filbert,  was  sold  a  few  years 
ao'o  at  the  mine  of  Holywell  for  31.  a  ton,  or  half  the  price  of  calamine.  It  is  roasted, 
without  any  other  preparation,  in  reverberatory  furnaces ;  which  are  about  8  feet  wide, 
and  10  lont' ;  the  distance  between  the  roof  and  the  sole  being  30  inches,  and  the  height 
of  the  fire-bridge,  18.  The  layer  of  blende,  which  is  placed  on  the  hearth,  is  about  4  or 
5  inches  thick ;  and  it  is  continually  stirred  up  with  rakes.  One  ton  of  it  requires,  for 
roastin*',  four  tons  of  coals  ;  and  it  suflfers  a  loss  of  20  per  cent.  The  operation  takes 
from  10  to  12  hours.  The  mixture  of  reducing  consists  of  one  fourth  part  of  the  desul^ 
phureted  oxyde,  one  fourth  of  calcined  calamine,  and  one  half  part  of  charcoal ;  which 
aflTords  commonly  30  per  cent,  of  zinc. 

The  En^'lish  furnaces  for  smelting  zinc  ores  are  sometimes  quadrangular,  sometimes 
round ;  the  latter  form  being  preferable.  They  are  mounted  with  from  6  to  8  crucibles  or 
pots  (see /ig.  1574),  arched  over  with  a  cupola  a,  placed  under  a  conical  chimney  b,  which 

serves  to  give  a  strong  draught,  and  to 
carry  oflf  the  smoke.  In  this  cone  there 
are  as  many  doors  c,  c,  c,  as  there  are  pots 
in  the  furnace ;  and  an  equal  number  of 
vents  d,  d,  d,  in  the  cupola,  through  which 
the  smoke  may  escape,  and  the  pots  may 
be  set.  In  the  surrounding  walls  there  are 
holes  for  taking  out  the  pots,  when  they 
become  unserviceable  ;  after  the  pots  are 
set,  these  holes  are  bricked  up.  The  pots 
are  heated  to  ignition  in  a  reverberatory 
furnace  before  being  set,  and  are  put  in  by 
means  of  iron  tong  machinery  supported 
upon  two  wheels,  as  is  the  case  with  glass- 
house pots,  c,  is  the  grate ;  /,  the  door  for 
the  fuel ;  g,  the  ash-pit.  The  pots  h,  h,h, 
have  a  hole  in  the  centre  of  their  bottom, 
which  is  closed  with  a  wooden  plug,  when 
they  are  set  charged  with  calamine,  mixed 
with  one  seventh  of  coal ;  which  coal  pre- 
vents the  mixture  from  falling  through  the 
orifice,  when  the  heat  rises  and  consumes 
the  plug.    The  sole  of  the  hearth  t,  t,  upon 

,       _,^  which  the  crucibles  stand,  is  perforated 

Wider  each  of  them,  so  that  they  can  be  reached  from  below ;  to  the  bottom  orifice  of  the 
pot,  when  the  distillation  begins,  a  long  sheet-iron  pipe  fe,  is  joined,  which  dips  at  its  end 
Into  a  water  vessel  I,  for  receiving  in  drops  the  condensed  vapors  of  the  zinc.    The  pot 


992 


ZINC. 


u  charged  from  above,  through  an  orifice  in  the  lid  of  the  pot,  which  is  left  open  altei 
♦he  firing,  till  the  bluish  color  of  the  flame  shows  the  volatilization  of  the  metal} 
immediately  whereupon  the  hole  is  covered  with  a  fire-tile  m.  The  iron  tubes  arc 
apt  to  get  obstructed  during  the  distillation,  and  must  therefore  be  occasionally  cleared 
out  with  a  redhot  rod.  When  the  distillation  is  finished,  the  iron  pipes  must  be 
removed  ;  the  coaly  and  other  contents  of  the  pot  cleared  away.  A  pot  lasts  about  four 
months  upon  an  average.  Five  distillations  may  be  made  in  the  course  of  14  days,  in 
which  from  6  to  10  tons  of  calamine  may  be  worked  up,  and  from  22  to  24  tons  ol'  coals 
consumed,  with  a  product  of  two  tons  of  zinc.  The  metal  amounts  to  from  25  to  40  per 
cent,  of  the  ore. 

1,  2,  is  the  level  of  the  upper  floor ;  3,  4,  level  of  the  lower  ceiling  of  the  lower  floor. 

Fig.  1232,  ground  plan  on  the  level  of  1,  2 ;  only  one  half  is  here  shown. 

The  zinc  collected  in  this  operation  is  in  the  form  of  drops,  and  a  very  fine  powder, 
mingled  with  some  oxyde.  It  must  be  melted  in  an  iron  pot  or  boiler,  set  in  a  proper 
furnace ;  and  the  oxyde  is  skimmed  off  the  surface,  to  be  returned  into  the  crucibles. 
The  metal  is,  lastly,  cast  into  square  bars  or  ingots. 

The  crucibles  are  discharged  at  the  end  of  each  operation,  by  withdrawing  the  conden- 
ser, breaking  with  a  rake  the  piece  of  charcoal  which  shuts  their  bottom,  and  then  empty- 
ing them  completely,  by  shaking  their  upper  part.  In  replacing  the  condenser-pipe  k 
(sec  second  pot  from  the  right  hand,  Jig.  1230),  the  flange  at  its  top  is  covered  with  a 
ring  of  loam-lute,  pressed  against  the  conical  bottom  of  the  crucible,  and  secured  in  its 
place  by  means  of  two  parallel  rods  o,  o,  which  can  be  clamped  by  screws  projecting  hori- 
zontally from  the  vertical  tunnel.     See  their  piaces,  indicated  by  two  open  dots  near  o,  o. 

A  smelter  and  two  laborers  are  employed  in  conducting  a  furnace ;  who  make,  with 
a  mixture  of  eq'ial  parts  of  fire-clay,  and  cement  of  old  pounds  finely  ground,  the  pots  or 
crucibles,  which  last  about  four  months.     Five  charges  are  made  in  15  days  ;  these  work 
up  from  6  to  10  tons  of  calamine,  consume  from  22  to  24  tons  of  coals,  and  produce  2  tons 
of  zinc,  upon  an  average.     The  following  estimate  of  prices  was  made  a  few  years  ago  :— 
3  tons  of  calamine,  at  £6  ------    £18    0    0 

24  ditto  coal,  at  5«.      - 

A  smelter,  at  2  guineas  a  week    ------ 

Two  laborers,  each  at  4».  per  day        -        -        -        -        - 

Incidental  expenses     -----... 

£29  18    0 
The  calamine  of  Alston-moor,  used  at  Shefiield,  is  not  so  rich ;  it  produces  at  most  only 
25  per  cent,  of  zinc.     The  coals  are  laid  down  at  a  cost  of  5«.  8d.  per  ton  ;  and  the  cala 
mine  laid  down  there  5/. ;  whence  the  zinc  will  amount  to  32/.  lis.  per  ton.    The  con- 
siderable importations  of  zinc  from  Belgium  and  Germany,  for  some  years  back,  have 
caused  a  considerable  fall  in  its  price. 

At  Liitlich,  where  the  calamine  of  Altenberg,  near  Aix-h-Chapelle,  is  smelted,  a 
reduction  furnace,  containing  long  horizontal  earthen  tubes,  is  employed.  The  roasted 
calamine  is  finely  ground,  and  mixed  with  from  one  third  to  two  thirds  its  volume  of  coke 
or  charcoal,  broken  to  pieces  the  size  of  nuts. 

Fig.  1576  represents  this  zinc  furnace  in  elevation ;  and  fig.  1577  in  a  vertical 
section  through  the  middle.      From  the  hearth  to  the  bottom  of  the  chimney  it  is 

9  feet  high,  and  the  chimney  itself  is 
18  or  20  feet  high,  a,  is  the  ash-pit; 
6,  the  grate ;  c,  the  fireplace ;  d,  the 
hearth ;  «,  e,  the  laboratory  ;  /,  the 
upper  arch,  which  closes  in  the  labor- 
atory ;  /',  the  second  arch,  which 
forms  the  hood-cap  of  the  furnace ;  g, 
the  chimney;  h,  the  fire- wall,  which 
rests  against  a  supporting  wall  of  the 
smelting-house.  Through  the  vaulted 
hearth  the  flame  of  the  fire  draws 
through  ten  flues  t,  t,  two  placed  in 
one  line ;  betwixt  these  five  pairs  of 
draught-openings,  upon  the  sole  of  the 
hearth,  the  undermost  earthen  tubes  fe, 
immediately  rest.  The  second  and 
third  rows  of  tubes  fe,  Ar,  lie  in  a 
parallel  direction  over  each  other,  at 
about  one  inch  apart;  in  the  sixth 
row  there  are  only  two  tubes ;  so  that 
At  their  two  ends  these  tubes  resl 


6 

0 

0 

2 

2 

0 

2 

16 

0 

1 

0 

0 

1576 


iPjesiraifMirwn 


there  are  22  tubes  altogether  in  one  furnace. 


ZINC. 


9dS 


vpon  fire-tiles,  which  form,  with  the  side-walls,  a  kind  of  checker-work  /,  I.  The  tubci 
are  4  feet  long,  4  to  5  inches  in  diameter  within,  five  fourths  of  an  inch  thick.  The  fir^ 
which  arrives  at  the  laboratory  through  the  flues  i,  i,  plays  round  the  tubes,  and  passes 
off  through  the  apertures  m,  m,  in  both  arches  of  the  furnace,  into  the  chimney,  n,  it 
an  opening  in  the  front  wall  between  the  two  arches,  which  serves  to  modify  the  draught 
by  admitting  more  or  less  of  the  external  air. 

The  two  slender  side  walls  o,  o,  of  the  furnace,  are  a  foot  distant  from  the  checker- 
work,  so  that  on  the  horizontal  iron  bars  y,  9,  supported  by  the  hooks  />,  />,  the  iron 
receivers  r,  r,  may  have  room  to  rest  at  their  fore  part.  These  receivers  are  conical 
pipes  of  cast  iron,  1^  foot  long,  posteriorly  IJ  inch,  and  anteriorly  1  inch  wide  at  the 
utmost.  After  the  earthen  tubes  have  been  filled  with  the  ore  to  be  smelted,  these 
conical  pipes  are  luted  to  them  in  a  slightly  slanting  position.  These  cones  last  no 
more  than  three  weeks;  and  are  generally  lengthened  with  narrow-mouthed  wrought- 
iron  tubes,  to  prevent  the  combustion  of  the  zinc,  by  contact  of  air.  When  the  furnace 
is  in  activity,  a  blue  flame  is  to  be  seen  at  the  mouths  of  all  these  pipes.    Every  two 

hours  the  liquefied  metal  is  raked  out  into  • 
shovel  placed  beneath ;  and  in  12  hours  the  charge 
is  distilled  ;  after  which  the  tubes  are  cleared  out, 
and  re-charged.  100  pounds  of  metallic  zinc  are 
the  product  of  one  operation.  It  is  remelted  at  a 
loss  of  ten  per  cent.,  and  cast  into  moulds  for  sale. 
Fig.  1578  is  a  longitudinal  section  of  the  fur- 
nace for  calcining  calamine  in  Upper  Silesia; 
fig.  1579  is  a  ground  plan  of  the  furnace,  a,  is  the 
orifice  in  the  vault  or  dome,  for  the  introductio* 
of  the  ore ;  6,  6,  apertures  in  the  side-walls,  shu" 
with  doors,  through  which  the  matter  may  ba 
turned  over;  c,  the  chimney;  d,  the  fire-bridge j 
e,  the  grate ;  /,  the  feed  opening  of  the  fire,  the 
fuel  being  pitcoaL  The  calamine  is  stirred  about 
every  hour;  and  after  being  well  calcined  during 
5  or  6  hours,  it  is  withdrawn ;  and  a  new  charge 
is  put  in.    These  Silesian  furnaces  admit  of  30 


1579 


w 


Ig" 


•  y^y. 


cwts.  at  a  time  ;  and  for  roasting  every  100  cwts.  15  Prussian  bushels  of  fuel,  equal  to  23 
English  bushels,  are  employed. 


15B0 


1581 


These  calcining  furnaces  are  sometimes  built  along- 
side of  the  zinc  smelting-furnaces,  and  are  heated  bf 
the  waste  flame  of  the  latter.  The  roasting  is  per- 
formed in  the  Netherlands  in  shafts,  like  small  blast 
iron-furnaces,  called  schachtofen. 

The  hearth  a,  xnfigi.  1580,  1581,  is  constructed  lor 
working  with  5  muffles,  one  of  which  is  long,  and  four 
short.  The  muffles  are  made  upon  moulds,  of  fire- 
clay mixed  with  ground  potsherds.  The  receivers 
are  stoneware  bottles.  The  grate  is  ten  inches  be- 
neath the  level  of  the  hearth.  6,  the  firebridge,  is 
proportionally  high  to  diminisli  the  force  of  the  flame 
upon  the  hearth,  that  it  may  not  strike  the  muffles, 
c,  is  the  opening  through  which  the  muffles  are  put 
in  and  taken  out ;  during  the  firing  it  is  partly  filled 
with  bricks,  so  that  the  smoke  and  flame  may  escape 
between  them ;  rf,  d,  are  openings  for  adjusting  the 
positions  of  the  muffles;  c,  cross  hoops  of  iron,  to 
strengthen  the  brick  arch  ;  /,  is  a  bed  of  sand  under 
the  sole  of  the-hearth.  During  the  first  two  days,  the 
fire  is  applied  under  the  grating;  the  heat  must  be 
very  slowly  raised  to  redness,  at  which  pitch  it  must 
be  maintained  during  two  days.  From  8  to  10  days 
are  required  for  the  firing  of  the  muffles. 

The  furnace  shown  in  figs.  1582,  1583,  1534.  is  for 
the  melting  of  the  metallic  zinc.  Fig.  1583  is  a 
front  view ;  fig.  1582  a  transverse  section ;  fig.  1584 
a  view  from  above ;  a,  is  the  fire-door ;  6,  the  trraie; 
c,  the  fire-bridge;  d,  the  flue;  e,  the  chimney; 
/ififi  cast-iron  melting-pots,  which  contain  each  about  10  cwts.  of  the  metal.  The  heat 
IS  moderated  by  the  successive  addition  of  pieces  of  cold  zinc.  The  inside  of  the  pota. 
should  be  coated  with  loam,  to  prevent  the  iron  being  attacked  by  the  zinc.    When  the 


994 


ZINC. 


xinc  is  intended  to  be  aminated,  it  should  be  melted  with  the  lowest  possible  heat,  tn< 
poured  into  hot  moulds. 

When  the  zinc  ores  contain  cadmium,  this  metal  distils  over  in  the  fonn  of  brown 

oxyde,  with  the  first  portions,  being  more  volatile 
than  zinc. 

Under  Brass  and  Copper,  the  most  useful  alloys 
of  zinc  are  described.  The  sulphate,  vulgarly  called 
white  vitriol,  is  made  from  the  sulphuret,  by  roast- 
ing it  gently,  and  then  exposing  it  upon  sloping 
terraces  to  the  action  of  air  and  moisture,  as  has 
been  fully  detailed  under  Sulphate  of  Iron.  The 
purest  sulphate  of  zinc  is  made  by  dissolving  the 
metal  in  dilute  sulphuric  acid,  digesting  the  solution 
over  some  of  the  metal,  filtering,  evaporating,  and 
ci7stallizing. 

Sulphate  of  zinc  is  added  as  a  drier  to  japan  var- 
nishes. 

The  ordinary  zinc  found  in  the  market  is  never 
pure  ;  but  contains  lead,  cadmium,  arsenic,  copper, 
iron,  and  carbon ;  from  some  of  which,  it  may  be 
freed  in  a  great  degree  by  distillation ;  but  even  after  this  process  it  retains  a  little  lead, 
with  all  the  arsenic  and  cadmium.  The  separation  of  the  latter  is  described  under  Cad- 
mium. Zinc,  free  from  other  metals,  may  be  obtained  by  distilling  a  mixture  of  charcoal 
and  its  siubcarbonate,  precipitated  from  the  crystallized  sulphate  by  carbonate  of  soda. 
By  holding  a  porcelain  saucer  over  the  flame  of  hydrogen  produced  from  the  action  of  dilute 
sulphuric  acid  upon  any  sample  of  the  zinc  of  commerce,  the  presence  of  arsenic  in  it 
may  be  made  manifest  by  the  deposite  of  a  gray  film  of  the  latter  metal.  Antimony,  how- 
ever, produces  a  somewhat  similar  efiect  to  arsenic. 

Zinc  is  extensively  employed  for  making  water-cisterns,  baths,  spouts,  pipes,  plates 
for  the  zincographer,  for  voltaic  batteries,  filings  for  fire-works,  covering  roofs,  and  a 
great  many  architectural  purposes,  especially  in  Berlin ;  because  this  metal,  after  it  gets 
covered  with  a  thin  film  of  oxyde  or  carbonate,  sutfers  no  further  change  by  long  expo- 
sure to  the  weather.  One  capital  objection  to  zinc  as  a  roofing  material,  is  its  combusti- 
bility. 

^.;; Chloride  of  zinc  has  been  recently  used  with  great  advantage  as  an  escharotic  for 
removing  cancerous  tumors,  and  healing  various  ill-constitutioned  ulcers.  It,  as  also  the 
aitrate,  forms  an  ingredient  in  the  resist  pastes  for  the  pale  blues  of  the  mdigo  vat. 

ZINC.  Mr.  Nicholas  Troughton,  of  Swansea,  obtained  a  patent  in  May,  1839, 
for  improvements  in  the  manufacture  of  this  metal.  His  invention  relates  to  the  appli- 
cation of  a  peculiar  apparatus  in  roasting  the  ores,  and  in  smelting  the  zinc.    Fig.  1585, 


represents  the  section  of  a  series  of  retorts  for  calcining  zinc  ores,  arranged  and  con- 
structed according  to  this  invention.  The  retorts  shown  in  this  figare  are  composed  of 
«  series  of  fire-tiles  or  parallelogram  slabs,  fl,  a,  a,  are  the  slabs  or  tiles,  which  con- 
stitute the  bottoms  of  the  retorts;  b,  6,  are  the  slabs,  which  constitute  the  upper  sur» 
faces  or  tops  of  the  retorts ;  and  c,  c,  are  slabs,  placed  vertically,  to  produce  the  sides  of 
the  retorts.  The  back  ends  of  the  retorts  are  closed  by  similar  tilts  or  slabs,  having  a 
hole  through  them  for  the  passage  of  the  vapors  evolved  from  the  ores ;  these  vapors 
•re  conveyed  in  any  direction  by  the  flue  at  that  end,  and  being  thus  separated  from  the 
products  of  combustion,  may  be  separately  acted  on,  according  to  either  of  the  patentee's 
former  inventions,  which  treat  of  the  separated  vapors  of  copper  ores  in  the  process  of 
"•ilcining  or  roasting  such  ores ;  or  the  separated  products  of  the  ore  may  be  allowed  to 
pass  into  the  atmosphere.  The  patentee  states,  that  by  treating  zinc  ores  in  furnaces 
or  retorts,  such  as  are  above  described,  considerable  saving  of  fuel  will  result,  and  the 
sine  ore  will  be  more  evenly  roasted  or  calcined. 


41 

1 


ZINC. 


995 


The  front  ends  of  the  retorts  are  closed  by  means  of  tiles  or  doors^  having  a  small 
hole  or  opening  in  each,  for  the  passage  of  atmospheric  air;  and  the  holes  may  be 
closed,  or  more  or  less  open,  accordmg  to  the  object  required.  The  retorts  are  charged 
through  the  hoppers  above,  which  have  proper  slides  to  close  the  openings  into  the 
retorts ;  the  quantity  charged  into  each  retort  being  sufficient  to  cover  the  lower  surface 
thereof  two  or  three  inches  deep.  During  the  operation  the  ore  must  be  raked  from 
time  to  time,  to  change  the  surfaces,  and  the  retorts  should  be  kept  to  a  moderate  red 
heat. 

The  second  part  of  this  invention  relates  to  an  arrangement  of  apparatus  or  furnace 
for  calcining  zinc  ores,  wherein  the  ore  is  subjected  to  the  direct  action  of  the  products 
of  combustion.    J'ig.  1586,  shows  a  longitudinal  section  of  the  furnace,  which  is  so  con- 


stracted  that  while  one  portion  of  the  zinc  ore  is  being  heated  in  a  manner  similar  to 
the  working  of  an  ordinary  calcining  surface,  other  zinc  ore  is  going  through  a  pre- 
paratory process  by  the  heat  that  has  passed  away  from  the  ore  which  is  undergoing 
the  completing  process  of  calcining.  This  furnace  may  be  heated  by  a  separate  fire,  to 
burn  by  blast  or  by  draught ;  or  the  flue  from  the  smelting  furnace  may  be  conducted  into 
the  entrance  of  this  furnace,  and  the  otherwise  waste  heat  of  the  smelting  furnace  will 
be  thus  brought  into  useful  application  for  calcining  or  roasting  of  zinc  ore;  and 
this  part  of  the  invention  is  applicable,  whether  it  be  applied  to  the  furnace,  or 
to  the  retorts  herein-before  explained,  and  will  be  found  a  means  of  saving  much 
fuel  in  the  processes  of  obtaining  zinc  from  ore.  «,  ^g.  1586,  represents  the  furnace, 
which  is  suitable  for  blast,  and  a  constant  supply  of  fuel  is  kept  up  in  the  chamber  by 
there  being  a  close  cover,  with  a  sand-joint,  c,  is  the  bed  or  floor  on  which  the  ore  is 
spread,  in  like  manner  to  an  ordinary  reverberatory  furnace ;  the  ore  is  stirred  about 
on  the  floor  by  passing  the  ordinary  rakes  or  instruments  through  the  openings,  dy  d  ; 
and  when  the  process  has  been  sufficiently  carried  on,  the  ore  is  discharged  through  the 
openings  €,  e,  which,  at  other  times,  remain  closed  by  fire-tiles.  The  heat  of  the  fire, 
and  the  flame  thereof,  passing  in  contact  with  the  ore  on  the  floor  or  bed,  c,  also  acts 
on  the  roof,/,  and  that  roof,/,  being  hot,  reverberates  the  heat  on  to  the  floor  or  bed, 
at  the  same  time  the  heat,  which  passes  through  the  roof,  heats  the  ore  in  the  upper 
chamber,  g;  and,  in  addition  to  such  heat  passing  through  the  roof,  the  flame  and 
heat  from  the  furnace,  having  passed  over  the  zinc  ore,  in  the  lower  compartment  of  the 
apparatus,  enters  into  and  passes  over  the  ore  m  the  chamber  g ;  and,  in  doing  so,  heats 
the  roof  A,  of  that  chamber,  and  also  the  ore  contained  therein ;  and  it  will  be  seen 
that  there  is  a  tliird  chamber,  t ;  the  heat,  therefore,  which  passes  through  the  roof  h, 
heats  the  ore  in  the  chamber  i.     In  working  this  arrangement  of  calcining  furnace  or 


apparatus,  when  the  charge  is  withdrawn  from  the  lower  chamber,  the  charge  in  the 
ehamber^  is  to  be  raked  into  the  lower  chamber  through  the  openings  for  that  pur- 
pose,  which,  at  other  times,  are  kept  covered  with  fire-tiles,  as  shown  in  the  drawing; 
and  the  charge  in  the  chamber  i  is  to  be  raked  into  the  chamber  ff,  and  a  fresh  supply 
«f  ore  charged  into  the  chamber  L 


996 


ZINC. 


ZINC. 


1588 


The  third  part  of  this  inrention  relates  to  a  mode  of  arranging  a  series  of  retorts 
side  by  side,  aud  of  applying  heat  thereto  in  the  process  of  smelting  or  distilling  zinc 
from  the  ore.  According  to  the  practice  most  generally  pursued  in  smelting  zinc,  the 
ore  is  sobmitted  to  the  action  of  heat  in  crucibles,  having  descending  iron  pipes,  which 
enter  into  vessels  containing  water :  all  which  is  well  understood,  as  well  as  the  process 
of  smelting  or  distilling  zinc  from  the  ores.     J'lg.  1587  is  a  side  elevation  of  two  seta  of 

furnaces  and  retorts,  arranged  according  to  this  invention, 
one  of  the  furnaces  being  in  section;  and  fq.  1588  is  a 
transverse  section  of  the  same,  a,  a,  are  a  series  of  retorts 
of  fire-day,  arranged,  side  by  side,  on  a  shelf  of  slabs  or 
fire-tiles.  These  retorts  are  each  closed  at  one  end  and 
open  at  the  other,  such  open  end  being  closed,  when  in 
ojjeration,  by  a  tile  or  door,  6,  fitting  closely,  and  luted 
with  fire-clay,  as  will  readily  be  traced  in  the  drawing. 
Each  series  of  retorts  is  placed  in  a  chamber,  c,  c,  in  such 
a  manner  that  the  heat  and  flame  of  the  fire  will  pass 
from  the  fire-place  or  furnace,  and  act  on  one  side 
of  the  retorts;  and  having  passed  along  all  the  series,  will  proceed  to  the  upper  part 
of  the  chamber,  c,  c,  and  heat  the  other  side  of  the  retorts ;  and  as  the  fires  are  main- 
tained and  urged  by  means  of  blasts  of  atmospheric  air,  the  heat  may  be  maintained 
and  regulated  with  great  advantage,  and  at  comparatively  small  cost  The  blasts  of 
air  may  be  produced  by  any  ordinary  blowing  machinery,  but  rotatory  blowers  are 
preferred,  and  the  air  may  be  cool  or  heated.  When  anthracite  coal  is  used  as  the 
fuel,  the  patentee  prefers  adopting  the  hot  blasts  at  a  temperature  of  at  least  500°  Fahr., 
and  such  heating  may  be  performed  by  any  of  the  well-known  means  now  very  gene^ 
rally  resorted  to  for  heating  the  blasts  of  air  for  smelting  iron,  d,  d,  are  iron  pipee^ 
descending  from  the  retorts  and  entering  into  vessels  containing  water,  similar  to  the 
apparatus  at  present  in  use  for  like  purposes.  Each  chamber,  c,  is  heated  by  its  separate 
furnace  or  fire-place,  which  have  openings,  to  be  closed  when  at  work ;  and  in  order  to 
^eep  up  a  supply  of  fuel  to  the  fire,  each  fire-place  has  an  inclined  chamber,  e,  which 
IS  filled  with  fuel,  and  then  closed  air-tight  by  the  cover,/,  fitting  into  a  sand-bath  or 
joint,  m  order  to  prevent  draught  upwards.  By  this  means  the  lower  portion  only  of 
the  fuel  will  be  in  an  ignited  state  when  at  work,  g,  g,  are  a  series  of  iron  doors,  one 
opposite  the  mouth  of  each  retort;  these  doors  are  capable  of  being  removed  by  sliding 
them  upwards,  till  the  portions  cut  out  at  the  sides  come  opposite  the  dips  or  holders^ 
/«,  h,  when  the  doors  may  be  removed,  in  order  to  get  at  the  retorts,  t,  is  a  chamber 
in  which  the  ore  is  heated  previous  to  its  being  placed  in  the  retorts.  The  arrange- 
ment of  the  brickwork,  the  construction  and  settling  of  the  furnaces,  being  clearly 
fthown  in  the  drawing,  no  further  description  need  be  given. 

The  patentee  remarks,  that  he  is  aware  attempts  have  been  made  to  employ  retorts 
in  the  smelting  of  zinc,  and  he  does  not,  therefore,  claim  the  same  generally;  but  he 
does  claim,  in  respect  to  the  third  part  of  this  invention,  the  mode  of  placing  a  series 
of  retorts  in  a  chamber,  c,  and  causing  the  heat  and  flame  to  pass  along,  under  and  over, 
such  series  of  retorts,  as  above  described  ;  and  he  also  claims  the  mode  of  smelting  zinc 
by  means  of  blast,  whether  the  heat  of  the  fuel  is  caused  to  act  on  a  series  of  retorts  or 
vessels,  in  the  manner  shown,  or  on  other  arrangements  of  retorts  or  vessels,  placed  in 
a  suitable  chamber  or  chambers. — Newton's  Journal,  C.  S.,  xxiii.  p.  81. 

ZINC  PURIFYING,  may  be  effected  by  melting  the  impure  metal  with  lead  in  equal 
parts  in  a  deep  iron  pot,  stirring  them  well  together,  skimming  off  the  impurities  as 
they  rise,  covering  the  surface  with  charcoal  to  prevent  oxidation,  and  keeping  them 
in  a  fused  state  for  three  hours.  The  lead  descends  to  the  bottom  by  its  greater  den- 
sity, and  leaves  the  zinc  above,  to  be  drawn  off  by  a  pipe  in  the  side  of  the  melting- 
pot.  This  contrivance  is  the  subject  of  a  patent  granted  to  Mr.  William  Godfrey  Kuel- 
ler  in  1844. 

ZINC  CASTING.  The  costliness  of  bronze  precludes  its  employment  as  a  material 
applicable  to  the  purposes  of  monumental  statuary  almost  entirely.  On  this  account 
the  extension  of  sculpture,  with  the  increase  in  the  number  of  private  collections  has 
been  seriously  impeded.  This  impediment^  however,  is  now  being  rapidly  removed  by 
the  advances  that  have  been  made  in  the  art  of  zinc-casting.  The  working  on  this 
metal  as  a  medium  for  high  art  had  at  first  to  make  good  its  progress  against  many  preju- 
dices, chiefly  on  the  part  of  artists  themselves.  In  this  lav  the  cause  which  long  re- 
tarded Its  progress  in  connection  with  sulphur,  whereas,  in  d'omestic  architecture,  its  ap- 
plication during  the  lasteighteen  years  has  superseded  tiiat  of  almost  every  other  material. 

Every  doubt  has  now  been  dispelled  as  to  the  comparative  durability  of  zinc  in  the 
open  air,  and  under  the  influence  of  every  variety  of  weather.  Chemistry  has^ demon- 
strated this  property  of  the  metal 

Zinc  is  readily  melted,  liquefies  very  completely,  and  therefore  is  better  adapted  t» 


997 


I 


cover  the  smallest  lines  in  the  mould  than  metals  of  a  harder  and  more  compact  tex- 
ture. The  zinc  casting  is  so  pure  and  so  finished,  on  being  turned  out  of  the  mould, 
that  the  work  requires  but  very  little  subsequent  chasing.  This  circumstance,  combined 
with  the  cheapness  of  the  metal  itself  (the  cost  of  a  zinc  cast  being  to  a  cast  in  bronze 
only  one-sixth  or  one-eighth),  renders  zinc  an  admirable  material  for  statuary.  But 
the  unfavorable  color  of  the  zinc  proved,  for  a  long  time,  a  great  obstacle  in  the  way 
of  its  application  to  these  purposes. 

This  difficulty,  however,  through  the  indefatigable  exertions  of  Mr.  Kiss,  the  founder 
of  this  important  branch  af  the  art  in  Berlin,  has  been  completely  overcome.  He  has 
succeeded  in  imparting  to  the  zinc  a  metallic  surface,  which  gives  to  the  cast  the  perfect 
aspect  of  Florentine  bronze. 

The  colossal  group  of  the  '^  Amazon,"  after  Kiss  of  Berlin,  cast  in  zinc  and  bronzed 
by  M.  Geiss,  presents  a  striking  specimen  of  the  perfection  to  which  the  latter  has 
brought  this  peculiar  invention. 

The  model  of  this  group,  cast  in  zinc  by  Geiss  of  Berlin,  and  lately  deposited  in  the 
Great  Exhibition,  will  establish  the  superiority  of  zinc  over  any  other  metal  for 
similar  purposes,  so  far  as  the  elements  of  cheapness  and  solidity  are  concerned. 

ZINC  PRINTING.  Representations  of  the  different  departments  of  the  Imperial 
establishment,  etched  on  zinc,  chemityped  and  printed  with  the  common  printing 
press — a  new  invention  by  Pul,  for  etching  on  zinc  in  a  raised  manner. 

If  this  art  be  not  calculated  to  supersede  wood  engraving,  it  can  be  applied  with  great 
advantage  for  certain  purposes  in  the  etching  style,  for  maps,  plans,  drawings  of  machines, 
Ac.  A  zinc  plate  is  covered  with  an  etching  grmmd,  the  drawing  etched  in  the  usual 
manner  with  the  needle,  and  bitten  in.  The  etching  ground  is  now  removed,  the  deep 
lines  cleaned  with  acid,  and  then  the  whole  plate,  in  a  warm  state,  covered  with  an 
easily  fusible  metal,  with  which,  of  course,  the  lines  of  the  drawing  are  filled  np. 
When  the  metal  thus  laid  on  is  cold  and  firm,  the  whole  plate  is  planed  until  the  zino 
appears  again,  and  only  the  lines  of  the  drawing  remain  filled  with  the  fusible  metal, 
which  is  easily  distinguished  by  its  white  color  from  the  gray  of  the  zinc.  The  whole 
plate  is  now  etched  several  times;  the  former  lines  of  the  drawing,  filled  with  this 
easily  fusible  negative  metal,  are  not  affected  by  the  acid  while  the  pure  zinc  is  eaten 
away.  In  this  manner  a  drawing  for  printing' in  the  copper-plate  press  can  be  con- 
verted into  one  in  relief  for  use  in  the  ordinary  printing  press. 

ZINKING  OF  IRON.  Iron  may  be  conveniently  coated,  in  the  humid  way,  by 
a  solution  of  sulphate  of  zinc,  or  one  of  the  double  salt  of  chloride  of  zinc  and  sal  am- 
oniac,  as  now  used  in  soldering  and  welding.  To  secure  success,  the  zinc  solution  should 
be  weak,  and  only  a  weak  galvanic  current  should  be  used,  otherwise  the  zinc  precipi- 
tated will  again  separate  from  the  iron  in  scales.  With  proper  precautions  the  deposit 
may  be  made  as  thick  as  strong  paper.  The  article  must  be  well  cleansed  before  un- 
dergoing the  operation. 

The  sulphate  is  prepared  by  saturating  with  sulphurous  gas  as  much  hydrate  of  car- 
bonate of  zinc,  recently  precipitated,  as  it  will  dissolve.  For  the  compound  salt,  dis- 
solve one  part  of  zinc  in  hydrochloric  acid,  and  to  this  solution  add  one  part  of  sal 
animoniac.  Evaj^orate  the  liquor,  and  crystallize.  The  crystals  are  colorlet^s  six-sided 
prisms,  translucid,  easily  soluble  in  water,  and  very  deliquescent. 

Zinked  Iron  weldable. — With  a  view  to  put  this  question  to  the  test  of  experiment  in 
the  most  severe  manner,  a  piece  of  zinked  iron  wire  rope  was  welded  up  into  a  bar,  by 
Mr.  James  Nasmyth.  In  the  first  place  it  was  found,  that  although  the  iron  wire  was 
quite  covered  with  metallic  zinc,  which,  although  partially  driven  off  in  the  process 
of  welding,  yet,  so  far  from  the  presence  of  the  metal,  or  its  oxide,  presenting  any 
inipedimeut  to  the  welding  of  the  iron  (is  in  the  case  of  lead),  the  iron  wire  welded 
with  remarkable  ease:  and  the  result  was  a  bar  of  remarkably  tough,  silvery -grained 
iron,  which  stood  punching,  splitting,  twisting,  and  binding,  in  a  manner  such  as  to 
show  that  the  iron  was  not  only  excellent,  but  to  all  appearance,  actually  improved  in 
quality  in  a  very  important  degree. 

Encouraged  by  such  a  result,  a  still  further  and  even  more  severe  trial  was  made, 
viz.,  by  welding  up  a  pile  of  clippings  of  galvanised  iron  plates,  or  sheet  iron  covered 
with  zinc,  as  in  the  former  experiments.  The  presence  of  the  zinc  appeared  to  offer  no 
impediment  to  the  welding,  and  the  result  was  a  bloom  or  bar  of  iron,  the  fracture  of 


result  indicated  from  5  to  10  percent.  Iiij;her  strength  than  the  best  samples  of  wrought 
iron,  thus  establishing  the  fact,  that,  so  far  from  the  presence  of  ziocLoing  d*isti  uc.tij^, 
to  the  strength  and  tenacity  of  wrought  iron,  the  contrary  ii  tRe  ca»5CH  "'  •  •  •  •  -  *  •*, 
I  may  mention,  that  bars  of  iron  were  heated  to  a  welding  J>e&t,  prepared  ^wi-siiefitk** 
ing,  in  the  usual  manner ;  and,  on  drawing  them  from  the  fire,  for  being  welded,  a 


■s^*«««R99l 


998 


ZIRCONIA. 


handful  of  zinc  filings  was  thrown  on  the  welding  hot  surface,  and  the  welding  pro- 
ceeded with.  In  this  severe  test  no  apparent  impediment  to  the  process  resulted  ;  the 
iron  welded  as  well  as  if  no  zinc  had  been  present  Judging  from  the  appearance  of 
the  iron  welded  up  from  zinc  covered  iron  scraps  not  only  as  respects  its  clear  silvery 
aspect,  but  also  the  increased  strength  which  such  exhibited  under  proof,  it  may  not  be 
unreasonable  to  infer,  that  some  important  improvement  might  be  made  in  the  manu- 
tacture  of  iron  by  the  actual  introduction  of  metallic  zinc  in  some  one  or  other  of  the 
stages  of  its  manufacture,  such  as  in  the  puddling  furnace.  What  the  nature  of  the 
action  of  the  zinc  is,  we  are  not  yet  able  to  say;  all  we  as  yet  know  is,  that,  so  far 
from  being  prejudicial  to  the  quality  of  the  iron,  it  appears  to  have  rather  an  improving 
effect;  and  that  to  such  an  extent  as  to  cause  us  to  desire  that  the  subject  may  receive 
the  attention  of  some  of  our  intelligent  iron  manufacturers,  so  as  to  put  the  matter  to 
the  test  of  actual  experiment  in  the  puddling  furnace,  or  any  other  stage  of  the  pro- 
cess such  as  may  appear  to  promise  the  best  results. 

I  may  name  a  curious  corroborative  fact,  that  tlie  strongest  cast-iron  made  in  Belgi- 
um, and  selected  for  the  casting  of  guns,  is  made  from  an  iron  ore  in  which  the  ore  of 
zinc  forms  a  considerable  portion.  Whether  the  superiority  of  this  iron  is  due  to  the 
presence  of  zinc  is  a  question ;  but  the  result  of  the  before  named  experiments  tend  to 
lead  to  the  supposition  that  such  may  be  the  case. 

The  small  town  of  Stolberg,  about  four  miles  from  Eschweiler,  is  a  centre  of  great 
manufacturing  activity.  Perhaps  the  most  interesting  establishment  for  strangers  are 
those  for  producing  zinc  from  calamine.  The  best  mines  belong  to  the  company  of  the 
Marquis  de  Sessenaye,  a  French  gentleman,  who  established  here  zinc  works  on  a  large 
scale,  in  which  the  following  system  is  adopted: — 

A  chimney  of  considerable  width,  but  of  moderate  height,  stands  in  the  centre  of  each 
batch  of  furnaces.  In  the  middle,  immediately  adjoining  the  chimney,  are  two  roasting 
furnaces,  in  which  the  ore  is  calcined.  To  the  right  and  left  of  these  are  two  pairs  of 
reducing  furnaces,  or  rather  two  large  reterberatory  furnaces,  which  are  charged  in  the 
middle  from  above,  and  which  are  open  at  the  side  towards  the  gangways.  In  the 
space  between  the  middle,  or  firing  place,  and  these  openings,  are  placed  a  series  of 
retorts  of  fire-proof  clay,  of  elliptical  shape,  into  which  moveable  necks  are  inserted, 
that  communicate  with  short  perpendicular  pipes,  which  fit  into  holes  in  the  earthen- 
plate,  under  which  openings  like  an  ash-pot  are  constructed.  The  ore  having  been 
well  calcined  in  the  roasting  furnaces,  are  turned  from  a  carbonate  into  an  oxide  of 
zinc,  is  first  powdered.  The  oxide  is  then  placed  in  the  retorts,  or  muffles,  as  they  are 
called,  and  the  furnaces  are  carefully  closed  with  clay,  and  highly  heated  to  throw  off 
the  oxygen  in  the  shape  of  gas.  One  result  of  the  great  heat  in  this  process  is  that 
a  large  proportion  of  the  metal  escapes  with  the  oxygen,  which  finds  its  way  through 
the  neck  of  the  retort  and  down  the  tube  connected  with  it,  where  the  reduced  metal 
falls  in  small  globular  particles.  The  metal  thus  deposited  is  washed  from  the  refuse 
that  falls  from  it>  and  is  melted  in  furnaces  placed  at  the  extremity  of  the  reverberatory 
furnaces.  The  heat  of  these  serve  to  melt  the  zinc  that  it  may  cast  into  thin  blocks  for 
rolling  into  sheets.  The  production  of  these  works  is  estimated  at  10  tons  per  dieno^ 
For  this,  a  consumption  of  seven  times  the  weight  of  coal  is  required. 

ZIRCORN.     See  HYAaNxn  and  Lapidary. 

ZIRCONIA,  is  a  rare  earth,  extracted  from  the  minerals  zircon  and  hyacinth;  it  is 
an  oxide  of  zirconium,  a  substance  possessing  externally  none  of  the  metallic  characters, 
but  resembling  rather  charcoal  powder,  which  burns  briskly,  and  almost  with  explosive 
Tiolence. 


IX 


THE  END. 


.  '    •     '  J    .    *   .   '     .     t 


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